Дисертації з теми "Efficiency index of use"

Thesis (MScEng)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: South African water service providers experience major problems with providing adequate water services to consumers. Water service providers in South African urban areas rely on traditional centralised infrastructure, such as bulk supply networks, to provide water services. Alternative supply and stormwater drainage methods should be encouraged to help mitigate these problems. The researcher thus aims to quantify the potential impact that three alternative methods may have on a given dwelling in terms of its dependence on traditional bulk water services. The three alternatives considered in this thesis are the construction of green roofs, rainwater harvesting and greywater re-use. An efficiency of dwelling water use index (EDWI) was developed during this research project. It was designed in such a way as to show what portion of municipal water services could be replaced within the given dwelling by using the proposed techniques. The final EDWI-rating is obtained by using the EDWI-software tool developed as a part of this research. The derived EDWI-rating ranges from 0 to 100, with a rating of 100 indicating a dwelling requiring only the removal of a portion of sewage by a municipality, but no external water supply. Such a dwelling would also not require any water from a municipal network to meet domestic demand and all stormwater from its roof would be utilised within the plot boundaries. Results presented in this thesis illustrate how different geographical regions require different system specifications to obtain optimal EDWI-ratings, thereby lowering their dependence on the respective municipal water services. Validation of the EDWI-system proved difficult as no similar index could be found during the literature review. It was therefore decided to benchmark the EDWI-system using three model dwellings with nine configurations producing a total of 27 analyses. The EDWI-system provides a conceptual foundation for sustainable water services to South African households in serviced urban areas. Future work could further improve the EDWI-system by testing its practical application so that it may be extended to act as a national barometer, used to compare decentralised water services in terms of sustainability.
AFRIKAANSE OPSOMMING:Suid-Afrikaanse waterdiensverskaffers ondervind groot probleme met die voorsiening van voldoende waterdienste aan verbruikers. Waterdiensverskaffers in Suid-Afrikaanse stedelike gebiede maak staat op tradisionele gesentraliseerde infrastruktuur, soos grootmaatvoorsienings netwerke, om waterdienste te verskaf. Alternatiewe voorsienings- en stormwater dreineringsmetodes moet aangemoedig word om hierdie probleme aan te spreek. Die studie poog dus om die potensiële impak wat drie alternatiewe moontlikhede kan hê op 'n gegewe woning in terme van sy afhanklikheid van die tradisionele waterdienste te kwantifiseer. Die drie alternatiewe moontlikhede wat in hierdie studie ingesluit word is die konstruksie van groendakke, reënwater oes en grys water hergebruik. 'n Huishoudelike water gebruik doeltreffendheids indeks (EDWI) is ontwikkel gedurende hierdie navorsingsprojek. Die indeks is ontwerp om aan te dui watter gedeelte van munisipale waterdienste deur die voorgestelde tegnieke vervang kan word. Die finale EDWI-gradering is verkry deur gebruik te maak van die EDWI-programmatuur wat ontwikkel is gedurende die navorsing. Die afgeleide EDWI- gradering wissel tussen 0 en 100, met 'n telling van 100 wat ‘n woning voorstel wat slegs die verwydering van 'n gedeelte van die riool deur die munisipaliteit vereis, maar wat geen eksterne watervoorsiening benodig nie. So 'n woning vereis dus geen water van ‗n munisipale netwerk nie, en alle stormwater van die dak word binne die erf gebruik. Resultate wat in hierdie studie voorgelê word illustreer hoe verskillende geografiese streke ander stelsel spesifikasies vereis om optimale EDWI-gradering te verkry. Die navorser kon geen indeks kry wat soortgelyk is aan die EDWI-stelsel om dit mee te vergelyk nie. Dit was gevolglik besluit om die indeks te standardiseer deur gebruik te maak van drie model huise met nege samestellings van alternatiewe, waardeur 27 ontledings ontwikkel was. Die EDWI-stelsel bied 'n konseptuele grondslag vir volhoubare waterdienste vir Suid-Afrikaanse huishoudings in gedienste stedelike gebiede. Toekomstige navorsing kan die EDWI-stelsel verder verbeter deur die praktiese toepassing te toets. Die stelsel kan uitgebrei word om ‗n nationale barometer vorm wat gebruik kan word om desentralisasie van waterdienste te meet in konteks van volhoubaarheid.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Forrageiras do gênero Cynodon são conhecidas por sua capacidade de resposta a altas doses de nitrogênio (N). Em condições tropicais o N pode se tornar um problema ambiental e financeiro devido à sua baixa eficiência de uso pelas plantas, principalmente como resultado de perdas por volatilização e/ou lixiviação. Portanto, objetivou-se com este trabalho avaliar fontes e doses de N no crescimento e produção de matéria seca do Tifton 85, bem como mudanças nas frações do carbono (C) no solo. Um experimento foi conduzido de 2012 a 2014, e constituiu de um fatorial em um delineamento de blocos ao acaso, onde os tratamentos foram a associação de duas fontes de N (nitrato de amônio [NA] e ureia), e cinco doses do nutriente (0, 60, 120, 180 e 240 kg ha-1 N por corte) aplicadas a cada 30 dias. Neste experimento foram utilizados NA e ureia enriquecidos com 15N como uma ferramenta para quantificar a recuperação do N advindo do fertilizante, nas plantas e no sistema solo-planta. As plantas foram cortadas para avaliar a produção de matéria seca, concentração de N na parte aérea e recuperação. O índice de área foliar (LAI), radiação fotossinteticamente ativa interceptada (PARi) e índice de clorofila (CI) foram mensurados no dia anterior ao corte. As amostras de solo foram coletadas nas parcelas que receberam NA e foram fracionadas em carbono orgânico particulado (POC), fração leve livre (FLF) e fração mineral (C-min); O teor de C nas frações foi quantificado. Os resultados demonstraram que o NA pode ser uma fonte mais eficiente somente quando a quantidade de precipitação é insuficiente para incorporar o fertilizante ao solo, resultando em maior produção de forragem, na somatória dos dois anos ambas as fontes produziram a mesma quantidade de matéria seca onde a maior produtividade 37,2 Mg ha-1, foi atingida com a dose de 210 kg ha-1 N por corte. Por outro lado, a quantidade de N recuperado pelo sistema de planta+solo foi maior quando a ureia foi utilizada, com destaque para a quantidade de N no solo, onde a ureia foi capaz de manter 10% mais N que o NA, a recuperação do nutriente diminuiu à medida que as doses foram elevadas. Nenhuma alteração no conteúdo de C foi notada devido às diferentes doses de N utilizadas, no entanto o POC e o C-min foram mais sensíveis às mudanças na camada de 0-0,1 m do que na camada de 0,1-0,2 m.
Cynodon hybrids are known by their ability to respond to high rates of nitrogen (N). In tropical conditions, N may become an environmental and financial issue due to its low efficiency of use by plants, mainly as a result of losses by volatilization and/or leaching. Therefore, the aims with this work were to evaluate N sources and rates on growth and dry matter yield of Tifton 85 and to determine changes in soil carbon (C) fractions in response to N fertilization. The 2-yr field experiment was conducted from 2012 to 2014, and consisted of a factorial design. Treatments were a combination of two sources of N (ammonium nitrate [AN] and urea) and five rates of the nutrient (0, 60, 120, 180 and 240 kg ha-1 N per cut) applied broadcast every 30 days. This study used AN and urea enriched with 15N as a tool to quantify the recovery of N derived from fertilizer in plants and the soil-plant system. Forage was cut at 30-d intervals for dry matter yield, shoot N concentration determinations and N recovery. The leaf area index (LAI), photosynthetic active radiation intercepted (PARi) and chlorophyll index (CI) were evaluated on the day before clipping. Soil samples were collected in plots receiving AN and they were fractionated in to particulate organic carbon (POC), free light fraction (FLF) and mineral fraction (C-min); The C concentration of the various fractions was determined. Results showed that AN was a more efficient source only when the amount of precipitation is insufficient to incorporate the fertilizer to the soil, resulting in increased production, in the sum of the two years both sources produced the same amount of dry matter in which the highest productivity, 37.2 t ha-1 , was achieved at the rate of 210 kg ha-1 N per cutting. On the other hand, the amount of N recovered by the plant+soil system was higher when urea was used, especially the amount of N in the soil, where urea was able to maintain 10% more N than AN, the nutrient recovery decreased as the rates were increased. No change in soil C concentration was detected in response to the different N rates used, however the POC and the C-min were more sensitive to changes in the layer of 0-0.1 m than the layer from 0.1-0.2 m.

L’anticipation des effets des changements climatiques nécessite une bonne compréhension dufonctionnement carboné des écosystèmes continentaux. L’une des principales contraintes liées àl’étude de ces écosystèmes est la forte variabilité à la fois spatiale et temporelle de leurs flux decarbone et de leurs réponses aux contraintes abiotiques. L’usage de méthodes de télédétectionoptiques pourrait permettre de suivre de façon spatialisée le fonctionnement des couverts végétaux.Ce travail vise à évaluer le potentiel de méthodes de télédétection pour décrire la structure et lefonctionnement de couverts végétaux à des échelles spatiales et temporelles variées. Pour ce faire,les relations entre indices optiques et phénomènes biologiques ont été étudiées en suivant unedémarche de transfert d’échelle, des échelles les plus fines aux plus larges. Il a été montré que le PRI(Photochemical Reflectance Index), utilisé en tant qu’indicateur du LUE (Light Use Efficiency), est parnature un signal composite qui reflète principalement la régulation du rendement de laphotosynthèse sur des échelles de temps fines, et la structure et composition biochimique ducouvert à l’échelle de la saison. L’analyse de courbes de réponse du PRI au PAR (PhotosyntheticallyActive Radiation) a permis de déconvoluer ces deux sources de variabilité, via l’introduction duconcept de PRI0 ou PRI d’une feuille idéalement adaptée à l’obscurité. Ce PRI0, capturant la variabilitédu PRI indépendante du LUE, a pu être mesuré à l’échelle de la feuille, et estimé à l’échelle de jeunescouverts végétaux et de la parcelle. Cette variabilité a pu être expliquée à l’échelle de la feuille et dejeunes couverts végétaux par les variations du contenu en pigment des feuilles. A l’échelle depeuplements adultes et de l’année, elle résulte cependant d’effets combinés de la compositionbiochimique et de la structure des couverts qui n’ont pu être séparés. Ces effets sont susceptiblesaux échelles larges de masquer en bonne partie, voire de biaiser la relation entre PRI et LUE. Il a enoutre été montré que la représentativité du PRI est limitée aux strates supérieures des canopées etdépend de la structure du couvert et du climat lumineux, ce qui peut limiter son intérêt en tantqu’estimateur du LUE à l’échelle de l’écosystème. Ces résultats soulignent la nécessité de prendre encompte la structure et la composition biochimique des couverts végétaux dans le cadre d’uneutilisation du PRI en tant que proxy du LUE de l’écosystème
In order to assess the effect of global warming, a good understanding of carbon functioning ofterrestrial ecosystems is needed. The study of terrestrial ecosystem carbon fluxes and responses toabiotic stress remain challenging due to their high spatial and temporal variability. The use of remotesensing may help us to describe those sources of variability. The aim of this work is to assess thepotential of remote sensing as a way to describe canopy structure and functioning over a broadrange of temporal and spatial scales. The relationships between optical indices and biologicalphenomenon were investigated over a range of increasing scales. The PRI (PhotochemicalReflectance Index), used as a proxy of the LUE (Light Use Efficiency) was shown to be a compositesignal, mainly impacted by the regulation of the LUE at short time scales, and by canopy structureand pigment content at seasonal scale. The analysis of PRI response to PAR (PhotosyntheticallyActive Radiation) allowed us to deconvolve those two sources of variability thanks to theintroduction of the PRI0 defined as the PRI of ideally dark adapted leaves. The PRI0 was shown toefficiently describe the LUE unrelated PRI variability, and could be measured at leaf scale, andestimated at the leaf, canopy and stand scales. This variability could be explained by changes in leafpigment content over the growing season at leaf and canopy scales. At the stand scale and over theyear, this LUE independent PRI variability resulted from combined effects of canopy structure andpigment content, which could not be separated. These effects may result in biased or masked PRIversus LUE relationships at larges scales. Moreover, it was shown that the in-situ PRI measurementsmainly responded to the LUE of sunlit leaves, depending on canopy structure and sky conditions. Thismay considerably hamper the use of the PRI as a proxy of the whole ecosystem LUE. These resultsillustrate the need to take canopy structure and pigment content into account while using the PRI asa proxy of the ecosystem LUE

Conselho Nacional de Desenvolvimento Científico e Tecnológico
Phosphorus (P) restriction to plants is one of major limiting factors for crop productivity. Alternatively to application of P-containing fertilizer, this obstacle to the vegetal production can be surmounted by developing of efficient plants in P-uptake and use. The objective of this work was to verify if there is behavior difference for Puptake and use efficiency and response to P-supply in 22 potato clones (Solanum tuberosum e S. microdontum) cultivated in vitro, as well as to report which characteristics of the plants are related to this ability. Concentrations of 10 and 100% of the concentration of P in standard MS medium were applied. Growth parameters and P-accumulation were determinated and P-uptake and use efficiency indexes in roots, shoot and plant were calculated. A wide behavior variation among tested potato clones for P-uptake and use efficiency was found. Dry matter production and P-accumulation had together a fundamental role to show the differences in Pefficiency among clones. P-use efficiency indexes showed same trend among clones and had an inverse relation with the uptake efficiency. The characteristics of root and shoot length and leaf number had secondary importance to the characterization of Pefficiency, and these were associated with only a few clones classified as efficient. Dry matter and P content distribution between root and shoot was not related with Pefficiency in potato. Moreover, these characteristics corroborate the exposure of the variability among potato clones according to the supply of P. Potato clones were classified using P-use efficiency index under low P and response to P-supply for shoot dry matter production: efficient-responsive: SMIC148-A, SMIB106-7, SMIG227- 2 and Michigan Purple; non-efficient-responsive: SMID040-4RY, SMIF313-3, SMIG145-1 and Macaca; non-efficient-non-responsive: S. microdontum, SMIJ319-7, SMIG274-3, SMIE040-6RY, SMIF212-3, SMIJ461-1 and Asterix; and efficient-nonresponsive: SMINIA793101-3, SMIJ456-4Y, Dakota Rose, SMINIA00017-6, SMINIA90244-1, SMIJ319-1 and SMINIA97145-2. These results are a valuable tool for genetic improvement of potato to P-use efficiency and response to P-supply.
O estresse causado pela restrição de fósforo (P) às plantas é um dos principais fatores limitantes à produtividade das culturas. Alternativamente à aplicação de fertilizantes fosfatados, este obstáculo à produção vegetal pode ser vencido pelo desenvolvimento de plantas eficientes na absorção e utilização de P. O objetivo deste trabalho foi verificar diferença de comportamento para a eficiência de absorção e utilização de P, bem como a resposta à aplicação em 22 clones de batata (Solanum tuberosum e S. microdontum) cultivados in vitro, e relacionar quais características das plantas estão ligadas a estas habilidades. Aplicaram-se as concentrações de 10 e 100% da concentração padrão de P do meio MS. Determinaram-se variáveis de crescimento e acumulação de P, bem como índices de eficiência de absorção de P e de utilização de P nas raízes, na parte aérea e na planta. Foi verificada ampla variação no comportamento entre os clones de batata testados para eficiência de absorção e utilização de P. A produção de matéria seca juntamente com a acumulação de P foram fundamentais para elencar as diferenças na eficiência ao P entre os clones. Os índices de eficiência de utilização de P mostraram a mesma tendência entre os clones e tiveram relação inversa com a eficiência de absorção. As características de comprimento de raízes e da parte aérea e número de folhas emitidas foram de importância secundária à caracterização da eficiência ao P, estando associadas a somente alguns clones classificados como eficientes. A partição de matéria seca e do conteúdo de P entre raízes e parte aérea não foi relacionada à eficiência ao P em batata. Por outro lado, estas características corroboram com a exposição da variabilidade existente entre clones de batata em função do fornecimento de P. Através da construção de um diagrama para eficiência de utilização de P e resposta à aplicação para a produção de matéria seca de parte aérea, os clones foram classificados como eficientes e responsivos: SMIC148-A, SMIB106-7, SMIG227-2 e Michigan Purple; não-eficientes e responsivos: SMID040-4RY, SMIF313-3, SMIG145-1 e Macaca; não-eficientes e não-responsivos: S. microdontum, SMIJ319-7, SMIG274-3, SMIE040-6RY, SMIF212-3, SMIJ461-1 e Asterix; e eficientes e não-responsivos: SMINIA793101-3, SMIJ456-4Y, Dakota Rose, SMINIA00017-6, SMINIA90244-1, SMIJ319-1 e SMINIA97145-2. Estes resultados são indícios da existência de variabilidade genética e, por isso, consistem numa valiosa ferramenta ao melhoramento genético da batata quanto à eficiência de utilização de P e responsividade a adubação fosfatada.

This research examined the mechanisms by which temperature, water availability and nitrogen (N) affect the dry matter (DM) yield potential of cocksfoot (Dactylis glomerata L.) dominant pastures. The experiment was a split plot design with main plots of fully irrigated (I) or dryland (D), sub-plots of N fertiliser at 800 kg N/ha in 2003/04; and 1600 kg N/ha in 2004/05 (+N) or 0 kg N/ha (-N). The potential environmental yield of an established 8 year old cocksfoot dominant pasture was 21.9 t DM/ha/y from I+N pastures compared with 9.8 t DM/ha by I-N pastures and 15.1 t DM/ha/y by D+N pastures. The lowest yields were from dryland pastures with no N which produced 7.5 t DM/ha/y in 2003/03 and 5.0 t DM/ha/y in 2004/05. The effect of seasonal temperatures on the DM production, when periods of water stress were excluded, was quantified using thermal time accumulated above a base temperature of 3°C as 7.0 kg DM/°Cd/ha for N fertilised pastures and 3.3 kg DM/°Cd/ha for pastures with no N. The 2.5 t DM/ha difference in yields of D-N pastures in 2003/04 and 2004/05 was the result of the duration, extent and timing of the water stress period. In both years the critical limiting deficit (DL) was calculated as 78 mm from the soil moisture deficit in the 0-0.8 m soil layers. Beyond DL yield decreased at a rate of 1.45%/mm in +N and –N pastures, relative to fully irrigated control pastures. Yields of D+N and D-N pastures were similar during periods of water stress with 0.4±0.1 t/DM/ha produced during the rotation ending 30/12/2003. This was less than from either the I-N (1.2 t DM/ha) or I+N (3.5 t DM/ha) pastures due to the reduction in the amount of photosynthetically active radiation intercepted by the canopies of the dryland pastures. However, in the rotation ending 2/5/2004, after autumn rain alleviated drought conditions, yield of the D+N pasture was 2.1 t DM/ha compared with 1.7 t DM/ha by I+N pastures. The effect of N on yield was described using a nutrition index which showed that as DM yield increased N% in the herbage declined. This is a function of the ratio between metabolic and structural N requirements rather than caused by ontogeny alone. Specific leaf N was determined at two harvests and appeared constant at a given point in time (1.0-1.6 g N/m² leaf). In contrast, specific pseudostem N increased from 0.8-1.0 g N/m² pseudostem at an NNI of 0.4 in –N pastures to 2.6-3.0 g N/m² pseudostem at an NNI of 1.2 in the +N pastures. Differences between the yields of +N and –N pastures were caused by differences in radiation use efficiency (RUE) as determined by the linear relationship (R²=0.76) between RUE and the nitrogen nutrition index (NNI). In this thesis, empirical relationships for the effects of temperature, water availability and N were derived and the physiological mechanisms which underlie these descriptions were identified. These relationships provide clear and simple explanations of the effects of environmental variables on the productivity of cocksfoot based pastures which will enhance understanding of the benefits and limitations of cocksfoot, particularly in dryland farming systems.

Fotossíntese é o processo biofísico pelo qual energia luminosa é transformada em energia química armazenada em compostos de carbono. A taxa fotossintética instantânea possui um forte padrão assintótico em resposta ao incremento da intensidade luminosa, porém quando integramos a fotossíntese em escalas espaciais e temporais maiores, observa-se um padrão linear de resposta entre radiação interceptada e produção. Esta abordagem permitiu o surgimento de modelos baseados nas taxas de conversão de energia radiante em biomassa seca, ou eficiência do uso da luz (ε). Valores publicados para o Eucalyptus estão na faixa de 0,5-2,5 g MJ-1, porém se faz necessário um entendimento mais profundo a respeito da sensibilidade destes valores às flutuações do clima e sua sazonalidade. Para isso, as taxas de crescimento, uso e eficiência do uso da luz foram monitoradas quinzenalmente durante 16 meses em parcelas de 18 clones de Eucalyptus, dos 1,3 aos 2,7 anos de idade. Foram testadas as hipóteses de que a produção de madeira aumentaria em função de incrementos no uso e/ou eficiência de uso da luz, assim como estes valores aumentariam respectivamente com incrementos no índice de área foliar e por uma alocação de carbono para o fuste, respectivamente. Os clones apresentaram uma grande amplitude de produtividade (9,9-22,7 Mg ha-1 ano-1) e arquiteturas de copa, capturando entre 65-95% da radiação incidente. Tais valores resultaram em uma eficiência do uso da luz média de 1,5 g MJ-1, variando entre 0,16-3,14 g MJ-1. Apesar de patamares distintos, os valores de eficiência de uso dos clones oscilaram de maneira similar, de modo que a radiação incidente foi a principal variável afetando a eficiência de uso da luz, estando ε positivamente relacionada a variáveis que expressam períodos de maior disponibilidade hídrica e negativamente relacionado a períodos de menor disponibilidade. Maiores valores de índice de área foliar efetivo (Le) acarretaram em maior interceptação de luz, porém as distintas arquiteturas de copa revelaram diferentes estratégias de captura de luz (0,3 < κ < 0,6). Apesar de uma maior interceptação, não houve correlação significativa com a produtividade, no entanto observou-se uma forte correlação entre eficiência do uso da luz e crescimento em madeira, resultado de uma maior alocação para o fuste. Apesar de evidenciar a relação entre alocação e eficiência, existem outros mecanismos associados às alterações observadas em ε que apenas uma caracterização completa dos fluxos de carbono pode elucidar.
Photosynthesis is the biophysical process by which light energy is converted into chemical energy stored in carbon compounds. The instantaneous photosynthetic rate has a strong asymptotic pattern in response to increases in light intensity, however when we integrate photosynthesis in larger spatial and temporal scales, there is a linear pattern of response between intercepted radiation and production. This approach has allowed the appearance of models based on radiant energy conversion rates into dry biomass, or light use efficiency (ε). Published values for Eucalyptus range from 0.5 to 2.5 g MJ-1, but a deeper understanding of the sensitivity of these values to climate fluctuations and seasonality is necessary. For this reason, wood growth rates, light use and efficiency were monitored every two weeks for 16 months at 18 Eucalyptus clones plots, from 1.3 to 2.7 years of age. Our hypothesis was that wood production would be positively related to light use and efficiency, as well these values would increase respectively with increases in leaf area index and carbon allocation to the stem. Clones showed a wide range of productivity (9.9 to 22.7 Mg ha-1 yr-1) and canopy architectures, capturing between 65-95% of incident radiation. Such values resulted in an average light use efficiency of 1.8 g MJ-1, ranging from 0.16 to 3.14 g MJ-1. Although different levels, light use efficiency values for the clones fluctuated similarly. Incident radiation was the main variable affecting the efficiency of dry matter conversion, and ε values were positively related variables expressing periods of greater water availability and negatively related to periods of lower availability. Larger effective leaf area index (Le) values resulted in higher light interception, but the different canopy architectures revealed different light capture strategies (0.3 < κ < 0.6). Despite a higher interception, there was no significant correlation with productivity; however there was a strong correlation between light use efficiency and wood growth, as a result of increased allocation to the stem. While evidencing the relationship between allocation and efficiency, there are other mechanisms associated with changes in ε observed that only one full characterization of the carbon fluxes can elucidate.

Os objetivos do estudo foram identificar o melhor modelo de restauração pela manipulação da composição florística e práticas silviculturais, e compreender como este melhor desenvolvimento é explicado pelos fatores que controlam o uso e a eficiência do uso da luz pelo dossel florestal. Com esta fundamentação foi instalado em 2004, na Estação Experimental de Anhembi/ESALQ/USP, o ensaio \"Modelos de restauração de áreas degradadas da Mata Atlântica visando o seqüestro de carbono\", com 20 espécies nativas e oito sistemas de restauração florestal, baseados em um delineamento fatorial 23, com três fatores, e dois níveis por fator: i) Composição florística, com maior (67%) ou menor (50%) percentagem de pioneiras; ii) Espaçamento de plantio (3x1m e 3x2m); e iii) Manejo silvicultural, com manejo usual (maior estresse ambiental) e manejo máximo (minimização do estresse ambiental), referentes ao controle da matocompetição e fertilização. Em todos os tratamentos, até os 42 meses, foram determinados: produtividade primária líquida de madeira (PPLM), com base em inventários semestrais, determinação da densidade básica da madeira e fator de forma de todas as espécies, índice de área foliar (IAF, com calibração de fotos hemisféricas), radiação fotossinteticamente ativa interceptada (RFAI, de postos meteorológicos e o IAF), eficiência do uso da luz (EUL=PPLM/RFAI) e o conteúdo de nitrogênio no dossel. Em relação ao fator Composição, as proporções de 50% ou 67% de pioneiras foram equivalentes, em todas as idades, para PPLM, IAF e EUL. Em relação ao fator Espaçamento, o plantio mais adensado (3x1m) propiciou maior estoque de biomassa aos 42 meses, comparativamente ao espaçamento 3x2m (13,0 Mg.ha-1 versus 10,3 Mg.ha-1), devido às suas maiores produtividades até os 24 meses. Porém, as PPLMs de ambos os espaçamentos não diferiram estatisticamente a partir dos 36 meses (5,5 Mg.ha-1ano-1). A maior produtividade do espaçamento 3x1m foi diretamente relacionada ao seu maior índice de área foliar entre os 36 e 42 meses, comparativamente ao espaçamento 3x2m (0,98 m2m-2 versus 0,71 m2m-2). Em relação ao fator Manejo, o manejo máximo proporcionou aumento de 4 vezes na biomassa de madeira aos 42 meses, comparativamente ao manejo usual (18,6 Mg.ha-1 versus 4,6 Mg.ha-1). Este maior estoque foi explicado por maiores IAFs (1,34 m2m-2 versus 0,34 m2m-2), levando a maiores produtividades primárias de madeira (8,5 Mg.ha-1ano-1 versus 2,4 Mg.ha-1ano-1, aos 42 meses). A interação Espaçamento x Manejo foi significativa para as três variáveis de estudo: IAF, EUL, e PPLM, mostrando que as respostas dos espaçamentos 3x1m e 3x2m à aliviação do estresse ambiental são distintas, e que o espaçamento 3x2m requer uma silvicultura mais intensiva para expressar sua máxima produtividade. Finalmente, a PPLM mostrou-se altamente relacionada com o IAF no verão (36 meses) (r2=0,96), sendo que a incorporação do conteúdo de nitrogênio no dossel elevou ainda mais tal relação (r2=0,99), evidenciando o alto potencial de utilização destas duas variáveis como diagnóstico da qualidade e produtividade de florestas de restauração. Assim, para as condições deste estudo o melhor modelo seria: Composição com 50%:50% de pioneiras:não-pioneiras, espaçamento 3x2m, e necessariamente, manejo máximo, com controle da matocompetição das gramíneas (Brachiaria decumbens) e fertilização.
The purpose of this study was to indentify the most appropriated restoration model by manipulating floristic composition and silvicultural practices, and to understand how the best development was explained by the factors that controls light use and light use efficiency at the canopy. A \"Restoration models for Atlantic Forest disturbed lands aiming carbon sequestration\" experiment was installed in 2004 using 20 Brazilian woody species and 8 forest restoration systems, in a factorial 23 design, with 3 factors and two levels per factor: i) Floristic composition with 67% and 50% of pioneer species; ii) Plant spacing (3x1m e 3x2m); and iii) Silvicultural management with usual (higher environmental stress level); and maximum (lower environmental stress level) silvicultural practices due to weed control and fertilization. Wood net primary production (WNPP), based on inventory surveys and wood density of all 20 species, leaf area index (LAI, with hemispherical pictures), absorbed photossintetically active radiation (APAR, on meteorological stations and LAI), light use efficiency (LUE=WNPP/APAR) and canopy nitrogen content was measured or estimated up to 42 months-old. The floristic composition proportion, with 50% and 67% of pioneers, were statistically equivalent, in all ages, for WNPP, LAI and LUE. The 3x1m spacing provided larger biomass stock at age of 42 months, comparatively to the 3x2m planting (13.0 Mg.ha-1 versus 10.3 Mg. ha-1), due a higher productivity until 24 months. However, WNPP of both spacing were equivalent after 36 months (5.5 Mg.ha-1year-1). The higher productivity of the 3x1m spacing was directly related to its greater leaf area index comparatively to the 3x2m spacing (0,98 m2m-2 versus 0.71 m2m-2). The maximum silvicultural practices provided a 4-fold increase on wood biomass at age 42 months, comparatively to the usual practices (18.6 Mg.ha-1 versus 4.6 Mg.ha-1). This larger stock was explained by a higher LAI (1.34 m2m-2 versus 0.34 m2m-2) leading to higher WNPP (8.5 Mg.ha-1year-1 versus 2.4 Mg. ha-1year-1, at 42 months). The Spacing x Management interaction was significant for LAI, LUE and WNPP, meaning that 3x2m and 3x1m spacing had distinct responses to environmental stress levels, showing that 3x2m depends on intensive silvicultural practices to express its maximum productivity. Finally, the WNPP was strongly related to LAI during summer months (at 36 months) (r2=0,96), and this relationship increased by the inclusion of canopy nitrogen content, showing that these two variables have a potential to be used to evaluate forest restoration quality and productivity. Thus, for the study conditions, the best model was: Composition 50%:50% of pioneer:non-pioneer species, 3x2m spacing, and the maximum silvicultural practices, with total weed control (Brachiaria decumbens) and fertilization.

Дисертація на здобуття наукового ступеня кандидата економічних наук за спеціальністю 08.00.04 "Економіка та управління підприємствами (за видами економічної діяльності)". Національна металургійна академія України, м. Дніпро. Національний технічний університет "Харківський політехнічний інститут", м. Харків, 2019. У дисертаційній роботі здійснено постановку та запропоновано вирішення важливого для економіки України завдання формування ринкового потенціалу металургійних підприємств з врахуванням оцінки використання їх людського капіталу. На основі аналізу характеру і тенденцій розвитку досліджень ринкового потенціалу запропоноване авторське визначення в якому під ринковим потенціалом підприємства розуміються можливості й ризики розвитку підприємства під впливом керованих та некерованих чинників ринку. Для підтвердження змісту отриманого визначення виконано аналіз можливостей оцінки ринкового потенціалу підприємства та чинників, що впливають на його величину. Запропоновано оціночний механізм капіталізації ринкового потенціалу підприємства, який включає: аналіз цільового ринку; визначення загальних та специфічних характеристик його складових; вибір оціночного підходу з обґрунтуванням вартісних та інтегральних показників (зокрема ринкової позиції), а також визначення ефективності капіталізації ринкового потенціалу (коефіцієнта капіталізації). Доведено, що поняття "ринкового потенціалу" та "людського капіталу" є взаємозв'язаними. Кількісною характеристикою цього зв'язку є параметр "вартість капіталу", аналітична база якого побудована на методах капіталізації підприємства. Розроблено структурно-логічну схему взаємозв'язку основних наукових понять розглянутих у дослідженні ("людський капітал – капіталізація – вартість підприємства – ринковий потенціал"). У роботі з'ясовано, що для ефективного функціонування та розвитку підприємства на ринку необхідно реалізувати його ринковий потенціал, а результатом реалізації ринкового потенціалу підприємства виступають як отримані доходи та ринкова вартість підприємства, так й інтегральні критерії, які відображують ринкову частку підприємства, його ринкову позицію та конкурентну репутацію. Для обґрунтування та визначення майбутніх стратегічних перспектив розвитку підприємства сформовано оціночну базу ринкового потенціалу підприємства, яка складається з відповідних ресурсів – активів підприємства, витрат та не фінансових показників діяльності. Встановлено що, оцінка людського капіталу здійснюється в процесі капіталізації його складової – трудового потенціалу, величина якого, в свою чергу, виступає вартісною оцінкою трудових ресурсів підприємства. Для вдосконалення оціночного інструментарію людського капіталу, як елементу ринкового потенціалу підприємства, в роботі досліджено, етапи розвитку сутності поняття людського капіталу. На основі проведених досліджень, сформований підхід, в якому людський капітал розглядається, як частка вартості підприємства та враховуються відмінності окремих форм капіталу, а саме економічна форма – частка, яка може безпосередньо визначатися вартісними показниками); культурна – частка, яка конвертується в економічний капітал частково – здатності, компетенції людини тощо; соціальна – у вигляді різного роду соціальних атрибутів, "зв'язків", connections); символічна – вид капіталу, що має визнання у суспільстві – престиж, репутація, честь тощо. У роботі досліджено економічна форма людського капіталу (тобто вона може безпосередньо визначатися вартісними показниками), як частка вартості підприємства і як реальне джерело коштів, які можуть бути безпосередньо інвестовані у розвиток конкретної людини або групи команди, колективу, нації тощо. Доведено, що кожна особа за час свого життя накопичує власний людський капітал. При цьому, ринкова вартість її праці та дохід, від вкладених в її розвиток підприємством коштів, і є та ціна, яку сплачує підприємство за можливість використання (запозичення) індивідуального людського капіталу і, згідно теорії відсотка, визначається як частка від основної суми капіталу, та виражає вартість послуги, яка забезпечується цим капіталом у момент його участі у виробничому процесі, як його тимчасового чинника. На основі запропонованої оціночної бази ринкового потенціалу, сформовано підходи до урахування людського капіталу, як його елементу. Для цього спеціально розроблені облікові документи, інформація з яких, є базою для формування балансу людського капіталу в системі управлінського обліку підприємства. На прикладі ринкової історії ПАТ "ЄВРАЗ – Дніпровський металургійний завод" встановлена сумарна недооцінка ринкової вартості підприємства за рахунок накопиченої вартості людського капіталу. Для визначення галузевих характеристик ринкового потенціалу сучасних вітчизняних металургійних підприємств в роботі сформовано поняття трансформаційного розвитку. Розрахована та представлена динаміка основних вартісних показників людського капіталу та проаналізовано тенденції трансформаційних процесів в гірничо-металургійному комплексі України, що впливають на ефективність використання людського капіталу металургійними підприємствами і, як наслідок, на реалізацію їх ринкового потенціалу. Сформовано блок-схему аналізу чинників формування ринкового потенціалу металургійного підприємства на основі якої досліджено значущість впливу показників вартості людського капіталу на ринковий потенціал металургійних підприємств групи Металургпрому (16 металургійних та феросплавних заводів цієї групи виготовляють понад 50% усієї продукції гірничо-металургійного комплексу). За допомогою кластерного аналізу визначено інтегральну характеристику – ринкову позицію металургійного підприємства серед своїх найближчих конкурентів на цільовому ринку. Результати досліджень, підтверджують наявність взаємозв'язку та обґрунтовують вплив показників оцінки використання людського капіталу на ринкову позицію металургійних підприємств та, відповідно, й на реалізацію їх ринкового потенціалу.
Dissertation for the degree of Candidate of Economic Sciences in specialty 08.00.04 – economy and management of the enterprises (by types of economic activity). – National metallurgical Academy of Ukraine, Dnipro, 2019. – National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2019. In the dissertation the formulation is made and the solution of the problem of formation of the market potential of metallurgical enterprises important for the economy of Ukraine taking into account the estimation of the use of their human capital is offered. On the basis of the analysis of the nature and tendencies of the development of market potential research, the proposed author's is defined in which under the market potential of the enterprise are understood the opportunities and risks of the enterprise development under the influence of managed and unmanaged factors of the market. In order to confirm the content of the obtained definition, an analysis of the possibilities of assessing the market potential of the enterprise and the factors that may affect its value was performed. The author's conception of the evaluation mechanism by capitalization of the market potential of the enterprise is proposed, which includes: analysis of the industry market and determination of the structure of the market potential; determination of general and specific characteristics of market potential components; choice of valuation approach: determination of value and integral indicators (in particular market position), and determination of capitalization efficiency of market potential (capitalization ratio). In order to substantiate the relationship between "market potential" and "human capital" within the logical chain "human capital – capitalization – enterprise value – market potential", a quantitative characteristic, which determines the homogeneity of this chain, is considered to be the parameter "cost of capital", the analytical base of which built on enterprise capitalization methods. In the work it is proved that for the effective functioning and development of the enterprise in the market it is necessary to realize its market potential, and as a result of realization of the market potential of the enterprise act both the received income and market value of the enterprise, as well as integral criteria that reflect the market share of the enterprise, its market position and competitive position. reputation. In order to substantiate and determine the future strategic prospects of the enterprise development, an estimation base of the market potential of the enterprise is formed, which consists of the corresponding resources and assets of the enterprise, expenses and non-financial indicators of activity. It is established that, as the potential of an enterprise cannot be determined and managed solely on the basis of the market value of the enterprise, so the potential of human capital must include all possible systemic factors of its value formation. To take into account human capital, as one of the assets of the enterprise, human capital is included in the estimation base of the market potential. In order to improve the human capital appraisal toolkit, as an element of the enterprise market potential, the stages of development of the essence of the concept of human capital are investigated. Based on the conducted research, an approach has been developed in which human capital is considered as a share of the value of the enterprise and the differences of particular forms of capital, namely the economic form (a share that can be directly determined by the cost indicators) are taken into account; cultural – share that is converted into economic capital in part – ability, human competence, etc.; social – in the form of various social attributes – connections); symbolic – the kind of capital that is recognized in society – prestige, reputation, honor, etc. It is proved that each person accumulates his own human capital during his life. The value of this accumulated individual human capital is in fact its market value, that is, it shows how much it costs to attract and retain a hired employee during the year. It is substantiated that individual human capital should be considered as the property of the employee, with the market price of his labor and income from the funds invested in its development by the enterprise and is the price paid by the enterprise for the possibility of using (borrowing) individual human capital and according to percent theory is defined as the proportion (percentage) of the principal. To determine the sectoral characteristics of the market potential of modern domestic metallurgical enterprises, the concept of transformational development has been formed. The dynamics of the basic human capital indicators at the sectoral level are determined, and the tendencies of transformation processes in the mining and metallurgical complex of Ukraine, which affect the efficiency of human capital utilization of metallurgical enterprises and, as a consequence, the realization of their market potential, are analyzed. Based on the proposed assessment base of market potential, approaches to accounting for human capital as its element have been formed. The work deals with accounting of individual human capital by value indicators. For information support of accounting of the state and estimation of the human capital in work the forms of the accounting cards are offered, information from which, should be the basis for formation of the management balance of the human capital in the system of management accounting of the enterprise. On the example of the activity of PJSC "EVRAZ – DMZ" it is found that the total undervaluation of the market value of the enterprise taking into account the accumulated cost of human capital amounted to UAH 583 million. An explicit model of analysis of factors of formation of market potential of metallurgical enterprise and estimation of indicators of use of their human capital has been formed metallurgical complex). Using cluster analysis and a set of market potential indicators of the above group of enterprises, the influence of human capital cost indicators on the integral characteristic of market potential – the market position of a metallurgical enterprise among its closest competitors in the domestic market – was proved.

Дисертація на здобуття наукового ступеня кандидата економічних наук за спеціальністю 08.00.04 "Економіка та управління підприємствами (за видами економічної діяльності)". Національна металургійна академія України, м. Дніпро. Національний технічний університет "Харківський політехнічний інститут", м. Харків, 2019. Дисертаційна робота присвячена удосконаленню і подальшому розвитку теоретичних положень, методичних підходів та науково-практичних рекомендацій з формування ринкового потенціалу металургійних підприємств на основі оцінки використання їх людського капіталу. Сформовано визначення поняття "ринковий потенціал підприємства", як можливості й ризики розвитку підприємства під впливом керованих та некерованих чинників ринку. На основі цього визначення запропоновано оціночний механізм капіталізації ринкового потенціалу підприємства, який включає: аналіз цільового ринку та визначення структури ринкового потенціалу; визначення загальних та специфічних характеристик його складових; вибір оціночного підходу: визначення вартісних та інтегральних показників (зокрема ринкової позиції), а також визначення ефективності капіталізації ринкового потенціалу (коефіцієнта капіталізації). Для обґрунтування та визначення майбутніх стратегічних перспектив розвитку підприємства сформовано оціночну базу ринкового потенціалу підприємства, яка складається з відповідних ресурсів – активів підприємства та враховує людський капітал, як один з активів, а також включає витрати та не фінансові показники діяльності підприємства. Визначено методичний підхід урахування та оцінювання людського капіталу підприємства. Для інформаційно-аналітичного забезпечення цієї діяльності розроблена форма облікового документу, інформація з якого, являється базою для формування управлінського балансу людського капіталу в системі управлінського обліку підприємства. На прикладі діяльності ПАТ "ЄВРАЗ – ДМЗ" встановлено, що сумарна недооцінка ринкової вартості підприємства з урахуванням накопиченої вартості людського капіталу склала 583 млн. грн. Сформовано блок-схему для аналізу чинників формування ринкового потенціалу металургійного підприємства та оцінки показників використання їх людського капіталу на основі якої, визначена інтегральна характеристика ринкового потенціалу – ринкова позиція підприємств сектору Металургпрому. Визначено динаміку вартісних показників людського капіталу на рівні різних секторів економіки, та проаналізовано тенденції трансформаційних процесів в гірничо-металургійному комплексі України, що впливають на ефективність використання людського капіталу металургійних підприємств і, як наслідок – на реалізацію їх ринкового потенціалу.
Dissertation for the degree of Candidate of Economic Sciences in specialty 08.00.04 – economy and management of the enterprises (by types of economic activity). – National metallurgical Academy of Ukraine, Dnipro, 2019. – National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2019. On the basis of the analysis of the nature and tendencies of the development of market potential research, the proposed author's is defined in which under the market potential of the enterprise are understood the opportunities and risks of the enterprise development under the influence of managed and unmanaged factors of the market. The author's conception of the evaluation mechanism by capitalization of the market potential of the enterprise is proposed, which includes: analysis of the industry market and determination of the structure of the market potential; determination of general and specific characteristics of market potential components; choice of valuation approach: determination of value and integral indicators (in particular market position), and determination of capitalization efficiency of market potential (capitalization ratio). In order to substantiate the relationship between "market potential" and "human capital" within the logical chain "human capital – capitalization – enterprise value – market potential", a quantitative characteristic, which determines the homogeneity of this chain, is considered to be the parameter "cost of capital", the analytical base of which built on enterprise capitalization methods. To take into account human capital, as one of the assets of the enterprise, human capital is included in the estimation base of the market potential. In order to improve the human capital appraisal toolkit, as an element of the enterprise market potential, the stages of development of the essence of the concept of human capital are investigated. Based on the conducted research, an approach has been developed in which human capital is considered as a share of the value of the enterprise and the differences of particular forms of capital, namely the economic form (a share that can be directly determined by the cost indicators) are taken into account; cultural – (share that is converted into economic capital in part – ability, human competence, etc.); social – (in the form of various social attributes – connections); symbolic – (the kind of capital that is recognized in society – prestige, reputation, honor, etc.). It is substantiated that individual human capital should be considered as the property of the employee, with the market price of his labor and income from the funds invested in its development by the enterprise and is the price paid by the enterprise for the possibility of using (borrowing) individual human capital and according to percent theory is defined as the proportion (percentage) of the principal. The dynamics of the basic human capital indicators at the sectoral level are determined, and the tendencies of transformation processes in the mining and metallurgical complex of Ukraine, which affect the efficiency of human capital utilization of metallurgical enterprises and, as a consequence, the realization of their market potential, are analyzed. The work deals with accounting of individual human capital by value indicators. For information support of accounting of the state and estimation of the human capital in work the forms of the accounting cards are offered, information from which, should be the basis for formation of the management balance of the human capital in the system of management accounting of the enterprise. On the example of the activity of PJSC "EVRAZ – DMZ" it is found that the total undervaluation of the market value of the enterprise taking into account the accumulated cost of human capital amounted to UAH 583 million. An explicit model of analysis of factors of formation of market potential of metallurgical enterprise and estimation of indicators of use of their human capital has been formed metallurgical complex). Using cluster analysis and a set of market potential indicators of the above group of enterprises, the influence of human capital cost indicators on the integral characteristic of market potential – the market position of a metallurgical enterprise among its closest competitors in the domestic market – was proved.

The global carbon (C) balance is vulnerable to disturbances that alter terrestrial C uptake and loss. Moderate disturbances that kill or defoliate only a subset of canopy trees such as insect defoliation, drought, and age-related senescence are increasing in extent and frequency; yet, little is known about the effect of moderate disturbance on forest production and the mechanisms sustaining or supporting the recovery of the C cycle across a range of moderate disturbance severities. We used a broad plot-scale gradient of upper canopy tree mortality within a large manipulation of forest disturbance to: 1) quantify how aboveground wood net primary production (ANPPw) responds to a range of moderate disturbance severities and; 2) identify the primary mechanisms supporting ANPPw resistance or resilience following moderate disturbance. We found that ANPPw was highly resistant to moderate disturbance, with production levels sustained following the senescence of 9 to > 60 % of the upper canopy tree basal area. As upper canopy gap fraction increased with rising disturbance severity, greater light availability to the subcanopy enhanced leaf-level C uptake and the growth of this formerly light-limited canopy stratum, compensating for upper canopy production losses. As a result, whole-ecosystem production efficiency (ANPPw/LAI) increased at high levels of disturbance severity and leaf area loss. These findings provide a mechanistic explanation for sustained ANPPw across the disturbance gradient, in which the physiological and growth enhancement of undisturbed vegetation was proportional to the level of disturbance severity. Our results have important ecological and management implications, showing that moderate disturbances may minimally alter ecosystem functions such as C storage.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The common bean (Phaseolus vulgaris L.) is an important calcium source for human diet, thus the evaluation of the calcium use efficiency in common bean a relevant tool for crop sustainability. The aims of this study were to evaluate the response in common bean cultivars with different calcium concentrations in nutrient solution on dry matter production, yield components and calcium, potassium and magnesium accumulations; to investigate the association between these characters; to evaluate the genetic variability of lines for calcium availability in the solution; and identify lines of common bean-efficient and responsive to calcium application by different indexes. For this, three experiments were conducted from March 2011 to July 2012 in greenhouse, in a completely randomized design, in splitplots. In the first two experiments were tested calcium concentrations in nutrient solution from 1.10 to 4.95 mmol L-1 as components of the main plot and the BRS Expedito, Carioca and Iraí cultivars on subplots in the first experiment, with the exclusion of the cultivar Iraí in the second experiment. The third experiment evaluated the efficiency and the response of the calcium use of 12 different common bean lines at low (1.10 mmol L-1) and high (3.85 mmol L-1) calcium concentrations in the nutrient solution. Higher values for dry matter and grain yield components were observed for 3.30 mmol L-1 and 4.95 mmol L-1 calcium concentrations in the solution. The common bean cultivars acumulate greater quantity of calcium in the leaves, followed by stems, pods and grains. Highest accumulation of calcium in the leaves was obtained at a 4.95 mmol L-1 calcium concentration in the nutrient solution, and the calcium concentration in the leaves was 21 times higher than the value obtained in the bean grains. The increase of calcium concentration in the nutrient solution up to the concentration of 4.95 mmol L-1 does not change the absorption and the accumulation of potassium and magnesium in leaves and grains. Indirect selection by greater dry matter and higher values of the variables that form the grain yield in common bean will be efficient to increase the accumulation of calcium in grains. The lines L 15, L 234, L 246 and L 77 respond to the increase on calcium supply in the solution, because more calcium accumulates in grain in the cultivation with high calcium concentration. The lines L 246 and L 15 are calcium use efficient in the plant, in the acquisition and grain production, and are not responsive to calcium application. The line L 77 is calcium use efficient in the plant and in the grain production and is responsive to the calcium application in the nutrient solution.
O feijão (Phaseolus vulgaris L.) é uma importante fonte de cálcio para a alimentação humana, sendo a avaliação da eficiência no uso de cálcio em feijão uma ferramenta relevante para a sustentabilidade da cultura. Foram objetivos desse trabalho avaliar a resposta de cultivares de feijão a diferentes concentrações de cálcio em solução nutritiva na produção de massa seca, nos componentes da produtividade de grãos e no acúmulo de cálcio, potássio e magnésio; investigar a associação entre esses caracteres; avaliar a variabilidade genética de linhagens de feijão quanto a disponibilidade de cálcio na solução e identificar linhagens eficientes no uso de cálcio e responsivas a aplicação deste mineral por diferentes índices. Para isso foram realizados três experimentos no período de março de 2011 a julho de 2012, em casa-devegetação, em delineamento inteiramente casualizado, com parcelas subdivididas. Nos dois primeiros experimentos foram testadas concentrações de cálcio na solução nutritiva de 1,10 a 4,95 mmol L-1 como componentes da parcela principal e as cultivares BRS Expedito, Carioca e Iraí nas subparcelas no primeiro experimento, com a exclusão da cultivar Iraí para o segundo experimento. No terceiro experimento foram avaliadas a eficiência no uso e a resposta de 12 linhagens de feijão em baixa (1,10 mmol L-1) e em alta (3,85 mmol L-1) concentração de cálcio na solução nutritiva. Maiores valores para massa seca e para os componentes da produtividade de grãos foram observados para as concentrações de 3,30 mmol L-1 e de 4,95 mmol L-1. As cultivares de feijão acumulam maior quantidade de cálcio nas folhas, seguido pelos caules, vagens e grãos. Maior acúmulo de cálcio nas folhas foi obtido na concentração de 4,95 mmol L-1 de cálcio na solução nutritiva, quando a concentração de cálcio nas folhas é 21 vezes superior ao valor obtido nos grãos de feijão. O aumento da concentração de cálcio na solução nutritiva até a concentração de 4,95 mmol L-1 não altera a absorção e o acúmulo de potássio e de magnésio nas folhas e nos grãos de feijão. A seleção indireta pela maior massa seca de parte aérea e maiores valores das variáveis que formam a produtividade de grãos em feijão será eficiente para aumentar o acúmulo de cálcio nos grãos de feijão. As linhagens L 15, L 234, L 246 e L 77 respondem ao aumento do suprimento de cálcio na solução, pois acumulam mais cálcio nos grãos em cultivo com alta concentração deste mineral. As linhagens L 246 e L 15 são eficientes no uso de cálcio na planta, na aquisição de cálcio e na produção de grãos, e não são responsivas à aplicação de cálcio. A linhagem L 77 é eficiente no uso de cálcio na planta e na produção de grãos e é responsiva à aplicação de cálcio na solução nutritiva.

The aim of this project was to enhance our knowledge of how nitrogen is transported and utilised within Brassica napus through the use of proteomics, phenotyping and genetic mapping. It highlights the importance of looking at all possible plant tissues to determine the mechanisms underlying seven macronutrients (N, P, Mg, Ca, S and Na) and five micronutrients (B, Cu, Fe, Mn and Zn) accumulation, since differences were observed between different tissues. Significant amount of mineral elements were found to remain in both the stem and roots at harvest, which in turn, highlights the inefficient mechanisms applied by some plants in the way they redistribute and utilise minerals such as N, P, K and S. Large genotypic differences in minerals concentration was found between different accessions of B. napus, ranging from 1.48-fold for Ca in the bottom of the stem to 20-fold for Na in top of the stem at maturity. Genotypes were identified that differed significantly from one another in relation to mineral concentration in the stem and root at harvest or in both. Differences were observed in the parents of the TN mapping population allowing a QTL approach to be adopted. Complex network of relationships between minerals were observed within and between tissues, and found to be dependent on the tissue and the growth stage. The strongest significant positive correlations (0.91 > r >0.71) were between Ca/P, S/Ca and N/Ca in taproot, Ca/Mg in stem, and Mg/P and N/S in seed. A significant source of N is that stored within proteins. Several proteins were shown to be accumulated significantly in the top part of the plants especially in the senescing silique walls and the stem adjacent to them. Putative vegetative storage proteins, VSPs, were identified in these tissues and we have suggested that these could be associated with N remobilisation. Development of a screening methodology based on these proteins through which quantitative analysis could be performed on a proteomic based experiment has been successfully developed which will allow the identification of QTLs associated with the N remobilisation and utilisation in plants. These finding could assist plant breeders in developing varieties with enhanced mineral utilisation efficiency. Such developments will eventually lead to significant benefits both economically and socially worldwide as they should lead to increased abilities to enhance crop yields of oilseed rape while lowering the fertiliser requirements.

Thesis (MScAgric)--University of Stellenbosch, 2003.
ENGLISH ABSTRACT: Poor water management and poor water use efficiency (WUE) have been identified as one of the major problems experienced by vegetable growers in most of the developing countries, including South Africa. This poor management and poor utilization of water have led to a drastic decline in the quality and quantity of available water. In South Africa agriculture uses about 50% of available water. Increasing water demand for domestic, industrial and mining uses, may decrease agriculture's share to less than the current 50%, henceforth, better utilization of this resource is imperative. Selection of a good irrigation system can limit water loss considerably. Some irrigation systems have a potential to save more water than others do. Since irrigation systems affect the WUE of crops, care should be taken when selecting an irrigation system under conditions of limited water quantity. Ebb-and- Flood watering systems have been introduced for effective sub-irrigation and nutrient delivery within closed systems. Such a system was adapted in South Africa, to develop a vegetable production unit for use by families in rural communities, while saving substantial amounts of water. A need to further improve the WUE of this system was subsequently identified. Two studies were conducted at the experimental farm of the University of Stellenbosch (Department of Agronomy). The first trial was conducted under controlled conditions in a glasshouse, and the second under open field conditions. In the first trial, Beta vulgaris (Swiss chard) and Amaranthus spp. ('Imbuya') were grown in two root media; gravel and pumice. In addition, an 'Ebb-and-Flood' and a 'Constant level' system were used with nutrient solutions at two electrical (EC) conductivity levels 1.80 and 3.60 mS cm-I. The results of this (2x2x2x2) factorial experiment indicated that a combination of the 'Ebb-and-Flood' system with gravel as a root medium produced the best results at a low EC, when 'imbuya' was used. A high total WUE was found with 'imbuya', (7.35 g L-I) at EC 1.80 mS cmicompared to a relatively low WUE of 5. 90 g L-I when the 3.60 mS cm-I nutrient solution was used. In the second trial, 'Imbuya's' foliage dry mass, leaf area and WUE was evaluated under field conditions at the Stellenbosch University experimental farm, during the summer of2002. The experimental farm (33°55'S, 18°52'E) is situated in the cooler coastal wine grape-producing region of South Africa with a relatively high annual winter rainfall. This trial was conducted on an alluvial soil, with clay content of 25% and a pH of 5.9 (KC!). A closed 'Ebb-and-Flood' system was compared with two open field irrigation systems ('Drip' and 'Flood') using nutrient solutions at two electrical conductivity levels (1.80 and 3.60 mS cm-i) in all three cases. Foliage dry mass, leaf area as well as WUE was best with 'Drip' irrigation, when a nutrient solution with an electrical conductivity of 3.60 mS cm-i was used. In spite of the fact that additional ground water was available for the soil grown 'Drip' and 'Flood' treatments, the 'Ebb-and-Flood' system outperformed the 'Flood' treatment, especially when the nutrient solution with an EC of 3.6 mS cm-i was used. Insufficient root aeration in the flooded soil could have been a contributing factor. The fact that the 'Ebb-and-Flood' and 'Drip' systems gave the best results when the high EC solution was used to fertigate the plants, may indicate that the plants could have hardened due to the mild EC stress, better preparing them to adapt to the extreme heat that was experienced in the field.
AFRIKAANSE OPSOMMING: Swak: bestuur van water en 'n swak: water-gebruik-doeltreffendheid (WOD) is as een van die belangrikste probleme geïdentifiseer wat deur groente produsente in die meeste ontwikkelende lande, insluitend Suid-Afrika, ervaar word. Hierdie swak bestuur en benutting van water het daartoe bygedra dat 'n drastiese afname in die kwaliteit asook in die kwantiteit van beskikbare water ervaar word. In Suid-Afrika gebruik die landbou-sektor ongeveer 50% van die beskikbare water. Toenemende water behoeftes vir huisgebruik, industrieë en die mynbou mag hierdie 50% aandeel van die landbou sektor laat krimp. Beter benutting van hierdie skaars hulpbron is dus noodsaaklik. Die keuse van goeie besproeiingsisteme mag waterverliese merkbaar beperk aangesien sekere sisteme se water-besparingspotensiaal beter as ander is. Aangesien besproeiingstelsels die WOD van gewasse beïnvloed, is spesiale sorg nodig waar 'n besproeiingstelsel onder hierdie toestande van beperkte waterbronne gekies moet word. 'Ebb-en-Vloed' sisteme kan aangewend word om water en voedingselemente van onder in 'n wortelmedium te laat opstoot en in 'n geslote sisteem te laat terugdreineer. So 'n sisteem is in Suid-Afrika ontwikkel waarmee groente vir families in landelike gebiede geproduseer kan word terwyl water bespaar word. 'n Behoefte om die WOD van hierdie produksiesisteem verder te verbeter is egter geïdentifiseer. Twee ondersoeke is by die Universiteit van Stellenbosch se proefplaas (Departement Agronomie) gedoen. Die eerste proef is onder beheerde omgewingstoestande in 'n glashuis uitgevoer en die tweede onder veld toestande. In die eerste proef is Beta vulgaris (Snybeet) en Amaranthus spp. ('Imbuya') in twee tipes wortelmedia; gruis en puimsteen verbou. 'n 'Ebb-en-Vloed' asoook 'n 'Konstante vlak' besproeiingsisteem is gebruik terwyl voedingsoplossings ook by twee peile van elektriese geleiding (EC) teen 1.80 en 3.60 mS cm-I toegedien is. Die resultate van hierdie (2x2x2x2) fakroriaal eksperiment het aangetoon dat 'n kombinasie van die 'Ebb-en-Vloed' sisteem met gruis as 'n wortelmedium die beste resultate teen 'n lae EC lewer waar 'imbuya' gebruik is. Die WOD met 'imbuya' was hoog (7.35 g L-1) by 'n EC van 1.80 mS cm-I, vergeleke met 'n relatief lae WOD van 5. 90 g L-1 waar die 3.60 mS cm-I voedingsoplossing gebruik is. In die tweede proef is 'Imbuya' se droë blaarmassa, blaar oppervlakte en WOD onder veldtoestande op die Universiteit van Stellenbsoch se proefplaas in die somer van 2002 ge-evalueer. Die proefplaas (33°55'S, 18°52'E) is in die koeler kusstreke van die wyndruif produksiegebied in die winterreëngebied van Suid-Afrika geleë. Hierdie proef is op alluviale grond met 25% klei en 'n pH van 5.9 (KCi) uitgevoer. 'n Geslote 'Ebb-en-Vloed' sisteem is met twee veld-besproeiingsisteme vergelyk ('Drup' en 'Vloed') terwyl voedingsoplossings teen twee peile van elektriese geleiding (1.80 en 3.60 mS cm-I) in al drie gevalle gebruik is. Blaar droëmassa, blaaroppervlakte asook die WGD was die beste met 'Drup' besproeiing waar die EC van die voedingsoplossing 3.60 mS cm-I was. Ten spyte van die feit dat ekstra grondwater vir die 'Drup' and 'Vloed' behandelings beskikbaar was, het die 'Ebben- Vloed' stelsel beter as die 'Vloed' behandeling gedoen veral waar die voedingsoplossing se EC 3.6 mS cm-I was. Swak wortelbelugting was waarskynlik die rede waarom vloedbesproeiing swak produksie gelewer het. Die feit dat die 'Drup' en die 'Ebb-en-Vloed' behandelings in die veldproef die beste gedoen het waar die EC hoog was, mag moontlik met die gehardheid van die plante verband hou wat aan ekstreem warm en dor toestande blootgestel was.

Plants require N to complete their life cycle. Without adequate concentration of N, crops will not produce their potential yields. For turfgrass systems, N fertilizer application allows for the maintenance of functional, aesthetic, and recreational properties. However, fertilizer mismanagement is common and leads to N pollution in the environment. Controlled-release and slow-release fertilizers can enhance nitrogen (N)-use efficiency, reduce N pollution, minimize the need for repeated fertilizer applications, and reduce turfgrass shoot growth and associated costs. In order to evaluate the effectiveness of these fertilizers in the Intermountain West, research is needed. The timing of N release was evaluated for seven urea fertilizers: uncoated, sulfur coated (SCU), polymer-sulfur coated (PSCU), and four polymer-coated (PCU) with release timings of 45, 75, 120, and 180 d estimated release. These products were placed on bare soil, a Kentucky bluegrass (Poa pratensis L.) thatch layer, and incorporated into soil. These three placement treatments were replicated to allow for enough samples to be placed in two locations. The first was outside in a field to represent field conditions with diurnal fluctuating temperatures and the second was placed in a storage facility to replicate laboratory conditions with static diurnal temperatures. The PCU prills incorporated into soil under field conditions generally released N over the estimated release period. However, when applied to bare soil or thatch, N from PCU had 80% or greater N release by 35 d after application regardless of expected release time. Fertilizers under laboratory conditions had minimal N release despite having similar average daily temperatures, suggesting that fluctuating temperatures impact N release. The PSCU and SCU treatments were no different from uncoated urea, showing no slow release properties for this particular product. Spring-applied N fertilizer trials were conducted over two years to determine the optimal N rate for Kentucky bluegrass. Similar PCU120 products were applied at 50, 75, and 100% of the recommended full rate, while also being compared to an unfertilized control and urea applied either all at once or split monthly. Spring-applied PCU showed minimal initial N response while urea applied all at once resulted in an initial spike of N uptake. Once PCU began to release N, there was minimal difference for all rates compared to urea split monthly for biomass growth, verdure, and shoot tissue N. Although at the 50% rate, there were a few sampling dates with slower growth and lower verdure. The decrease in verdure at this low rate was slight, and it is recommended that PCU could be applied effectively at a reduced rate between 50 and 75%. Although for better results, additional quick release N is required to compensate for early season lag in N release.

Increasing the potassium use efficiency (KUE) of crops will be important in satisfying growing demand for food that is cost-effective and has minimal environmental consequences. The work presented in this thesis contributes to this aim by exploring the measurement of KUE and identifying drivers responsible for differences in KUE between rice genotypes at the physiological and genetic levels. In Chapter 2, a mathematical model was constructed based on growth experiments using cv. IR64 rice plants. Subsequently, sensitivity analysis was used to assess how best to measure KUE experimentally, showing how KUE could be comprehensively measured using a small selection of metrics. KUE was then quantified in over 300 rice genotypes in Chapter 3. From this, high performing rice genotypes were identified along with associations between KUE metrics and physiological traits. While key physiological drivers of differences between genotypes differed with metrics, the replacement of potassium by sodium was consistently found to aid KUE. In Chapter 4, differences in KUE between rice genotypes were then explored at the genetic level, using genome-wide association studies (GWAS) to describe the genetic underpinnings of KUE for the first time. This resulted in the identification of KUE-relevant quantitative trait loci (QTLs) and candidate genes. Both novel and previously described QTLs for KUE were found and links between the sub-population structure present in rice and the genetic architecture of KUE were uncovered. Furthermore, several genes coding for proteins with regulatory functions were identified in GWAS analyses, as were genes for sodium transport proteins. Taken together, the findings of the work presented in this thesis could be used to inform future KUE studies as well as providing candidate physiological traits and genetic loci for crop improvement.

Food security for a growing population presents a significant challenge for crop production, with increasing pressures upon agriculutral productivity. There is a vast need to improve crop yield and quality using an efficient approach that does not present negative environmental impacts. A novel interrogation technique that is able to provide information of the overall health of a plant, would be extremely beneficial in an agriculutral, as well as research, setting. This information could be utilised to better understand the mechanisms of plant functions, including stress responses. Vibrational spectroscopy encompasses a range of techniques that are able to derive chemically specific information from a biological sample in a rapid, nondestructive and cost-effective manner. Fourier-transform infrared (FTIR) spectroscopy and Raman spectroscopy are two such approaches and have been readily implemented across biological samples. However, their applications in the field of plant science have been relatively underexploited. This is largely associated with the presence of water and fluorescent metabolites found in plant tissues. The application of attenuated total reflectance (ATR)-FTIR and spontaneous Raman spectroscopy for in vivo plant monitoring to elucidate spectral alterations indicative of healthy plant growth in a non-destructive manner. These approaches are able to characterise the biochemical signature of leaves at distinct developmental stages, and correspond to known biological processes within the leaf such as cell wall expansion. This information is useful prior to monitoring studies as normal leaf growth could be considered background variance. No significant local or systemic effects manifest as a consequence of interrogation with these techniques, establishing this as a non-destructive approach for plant system investigations. Raman microspectroscopy as a tool for monitoring nutrient uptake at the leaf surface is also considered, alongside complementary ion probe and elemental analysis. Such a technique is useful in the agrochemical production of foliar fertilisers, where the efficiency of specific formulae can be rapidly compared. This can also further the current understanding of nutrient transport into plant tissues, as well as translocation. Agriculturally relevant levels of calcium were applied to the leaf surface and uptake was successfully illustrated at concentrations as low as 15 mM using Raman microspectroscopy. Ion probe analysis also complemented these findings, with elemental analysis unable to detect this subtle uptake of nutrients. This assay is now being implemented in agrochemical practise as a fertiliser screening method. Deficiencies in essential nutrients such as calcium are detrimental to crop yield and thus are a potential target for improving crop production. A range of spectroscopic methods, including the use of synchrotron radiation, were utilised to presymptomatically detect these deficiencies prior to their onset in live samples. Coupled with multivariate analysis, these techniques discriminate between deficient and control samples with high sensitivity and specificity, without extensive sample preparation that traditional analytical techniques require. These results suggest that Raman and ATRFTIR spectroscopic approaches could highly valuable in the field, where plant health and nutrient status could be assessed rapidly in situ. Here it is shown that these issues can be overcome and that qualitative spectral measurements can be obtained from plant samples. Due to the non-destructive nature of these approaches, they can be applied for a wider range of crop screening investigations, including the efficiency of nutrient uptake, as well as distinguishing nutrient deficiencies presymptomatically. As such, these spectroscopic methods may be implemented to unearth further details regarding nutrient use efficiency during crop production.

Narrow waveband spectral reflectance, chlorophyll fluorescence and gas exchange measurements were made sequentially on individual leaves of Vicia faba at three levels of 500, 1000 and 1500 mmol m^-2 s^-1. PRI was calculated from the reflectance data and correlated with LUE calculated from gas exchange and photosystem II( PS II) efficiency measured from chlorophyll fluorescence. PRI was linearly related to photosystematic LUE and PS II efficiency over the range of light levels and followed the diurnal light response of photosynthetic light-use-efficiency. The relationship between PRI and LUE was then investigated over boreal forests in Canada. Reflectance measurements of four stands were made from a helicopter-mounted spectroradiometer during the 1994 growing season. Eddy covariance towers were measuring CO₂ fluxes during this time and LUE was calculated from these data. A strong linear relationship was found between PRI and LUE for the four sites, and when expressed on a functional type basis of conifer and deciduous, the relationships were stronger still. The relationship between PRI and LUE at the canopy scale was further investigated in boreal forest in Siberia during the "green-up" period from winter into spring in 2000. During this time the photosystems were under stress as a result of extremes of temperature (from -20°C to +35°C) coupled with a high radiation load. Reflectance measurements of four stands were made from a helicopter-mounted spectroradiometer and PRI was calculated from these data. Eddy covariance towers were operating at each site and offered a means to calculate LUE. A significant linear relationship was apparent between PRI and LUE although the relationship was weaker than that found between PRI and LUE in the Canadian boreal forest. Collating the data for all the boreal forests highlighted a difference between the slopes of the PRI:LUE relationship. Reflectance measurements were also made from the eddy covariance tower of the Scots pine canopy and needles were sampled simultaneously for xanthophyll pigment determination. Strong linear relationships were observed between PRI, the epoxidation state of the xanthophyll cycle and LUE over the seasonal change and the diurnal cycle.

1. Ovsyuk, NV (2014). Staff motivation: essence and modern problems. Business inform, (2). 2. Cherep AV Methodical approaches to assessing the effectiveness of the use of labor potential of enterprises. URL: http://www.agro-svit.info/pdf/15_2012/12.pdf.
The essence of the category "staff" is considered. The approaches and methods of estimating the efficiency of the use of labor resources at the enterprise are revealed, the factors influencing them are investigated.
Розглянуто сутність категорії «персонал». Розкриті підходи та методи оцінки ефективності використання трудових ресурсів на підприємстві, досліджені фактори, що впливають на них.

The research topic is: Tools for the revision of a maintenance strategy for an explosives manufacturing plant, using asset management principles. This research has specific reference to the SASOL Prillan plant based in SASOL, Sasolburg. The purpose of this research is to identify tools for the revision of a maintenance strategy for an explosives manufacturing plant, using asset management principles. These tools must be aimed to increase the proactive work capacity index, Figure 3, and to identify and/or develop tools that can be used by the engineering team of this explosives manufacturing plant to increase equipment reliability and performance. In this research assets include people. The meaning and application of asset management principles were researched and the tools needed to combine existing efforts and future needs are discussed. The human element to ensure the successful implementation of an asset management culture was researched and attributes of leaders and a change model is presented. This research was done into the wider engineering management discipline and not only maintenance. The method used to gather data was by means of interviews of a sample group within this organization. As this manufacturing unit makes use of subject matter experts, these support functions and plant personnel that were not interviewed, were issued with questionnaires to ensure that the sample group is a fair representation of the total manufacturing facility. To obtain a holistic view of potential shortcomings within the current maintenance strategy, all disciplines and levels within this operation were interviewed and commonalities of various asset management models were determined and used to define existing problem areas. This data was used to determine statistical correlations. The case study presented in Chapter 1 indicates that there is a case for change that can improve the proactive work capacity index of the engineering team. The results of this research confirm that there is in fact a real requirement to increase spares accuracy, improve on technical training as well as a need to establish visual performance indicators (dashboard) to measure overall equipment efficiency with the goal toTools for the revision of a maintenance strategy for an explosives manufacturing plant, using asset management principles increase equipment reliability and performance. The technical training referred to in this research reflects on training of people on equipment after investment in new technology. The current spares holding strategy is lacking equipment description accuracy. Furthermore, it is recommended that the implementation of career paths and development plans for individuals must be developed to create an environment of learning. The use of user status information captured on the computerized maintenance management system (SAP R/3) can add to the management of works orders and indicate where the focus must be to complete overdue work orders. Open work orders should be used to manage expenditure, to measure planning efficiency and to manage the cash flow of the business. The use of overall equipment efficiency and engineering efficiency measures is recommended and must be visually displayed on a “dashboard”. It was recommended that the engineering and operations personnel of this manufacturing plant be trained in asset management principles and that balanced scorecards are developed to ensure that the strategies of the various departments are aligned with the business strategy. Diagram 1 best illustrates the thinking and process flow of this research. The flow diagram shows five distinct stages and the appropriate objectives and/ or elements that were considered. The dissertation is also structured in this manner. All abbreviations, acronyms and definitions used in this document were listed in APPENDIX B
Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2009.

A lack of a simple index that monitors ventilatory efficiency at the bedside has meant that oxygenation has been the predominant variable that is used to monitor adequacy of ventilatory strategies and disease severity in mechanically ventilated patients. Due to complexities in its measurement, deadspace ventilation, the traditional method to track ventilatory failure, has failed to become integral in the management of mechanically ventilated patients. Ventilatory ratio (VR) is an easy to calculate index that uses variables measured at the bedside: [Mathematical equation appears here. To view, please open pdf attachment] where [Symbols appears here. To view, please open pdf attachment] is taken to be 100 ml.kg-1.min-1 based on predicted body weight and [Symbols appears here. To view, please open pdf attachment] is taken to be 5 kPa. Physiological analysis of VR dictates that it is influenced by deadspace fraction and CO2 production. Physiological analysis of VR was validated in a benchside lung model and a high fidelity computational cardiopulmonary physiology model. The impact of CO2 production on VR was investigated in patients undergoing laparoscopic surgery who received exogenous intraperitoneal CO2. This showed that delta values of the 2 variables were linear. The variability of CO2 production was examined in ICU patients and results of the study showed that variability of CO2 production was small. In an ICU population correlation of VR was stronger with deadspace in comparison to CO2 production. Of these two variables, deadspace had the greater effect on VR. The clinical uses of VR were examined in 4 databases of ICU patients. VR was significantly higher in non-survivors compared to survivors. Higher values of VR were associated with increased mortality and more ventilator days. A rising values of VR over time was also associated with worse outcome. VR is a simple bedside index that provides clinicians with useful information regarding ventilatory efficiency and is associated with outcome.

This doctoral thesis consists of three essays. In the first essay I investigate the presence of productivity convergence in eight regional pulp and paper industries of U.S. and Canada over the period of 1971-2005. Expectation of productivity convergence in the pulp and paper industries of Canadian provinces and of the states of its southern neighbour is high since they are trading partners with fairly high level of exchanges in both pulp and paper products. Moreover, they share a common production technology that changed very little over the last century. I supplement the North-American regional data with national data for two Nordic countries, Finland and Sweden, which provides a scope to compare the productivity performances of four leading players in global pulp and paper industry. I find evidence in favour of the catch-up hypothesis among the regional pulp and paper industries of U.S. and Canada in my sample. The growth performance is at the advantage of Canadian provinces relative to their U.S. counterparts. However, it is not good enough to surpass the growth rates of this industry in the two Nordic countries. It is well-known that econometric productivity estimation using flexible functional forms often encounter violations of curvature conditions. However, the productivity literature does not provide any guidance on the selection of appropriate functional forms once they satisfy the theoretical regularity conditions. The second chapter of my thesis provides an empirical evidence that imposing local curvature conditions on the flexible functional forms affect total factor productivity (TFP) estimates in addition to the elasticity estimates. Moreover, I use this as a criterion for evaluating the performances of three widely used locally flexible cost functional forms - the translog (TL), the Generalized Leontief (GL), and the Normalized Quadratic (NQ) - in providing TFP estimates. Results suggest that the NQ model performs better than the other two functional forms in providing TFP estimates. The third essay capitalizes on newly available high frequency energy consumption data from commercial buildings in the District of Columbia (DC) to provide novel insights on the realized energy use impacts of energy efficiency standards in commercial buildings. Combining these data with hourly weather data and information on tenancy contract structure I evaluate the impacts of energy standards, contractual structure of utility bill payments, and energy star labeling on account level electricity consumption. Using this unique panel dataset, the analysis takes advantage of detailed building-level characteristics and the heterogeneity in the building age distribution, resulting in buildings constructed before and after mandatory energy standards came into effect. Estimation results suggest that in commercial buildings constructed under a code, electricity consumption is lower by about 0.48 kWh per cooling degree hour. When tenants pay for their own utilities, consumption is lower by 0.82 kWh per cooling degree hour. The Energy Star effect is a 0.31 kWh reduction per cooling degree hour. Finally, peak savings for all three variables of interest occur at 2pm in the summer months, whereas peak summer marginal prices at DC's local electric utility occur at 5pm.

Current maximum efficiency of phosphorus (P) fertilizers that is utilized by plants in the same year of application ranges from near zero to thirty percent. Despite low utilization of P in crop production, yields are often limited by P deficiencies. Innovative technology is requisite to achieve greater efficiency as fertilizer demands are increasing, while phosphorus mineral resources are rapidly being depleted. A growing environmental concern for nutrient pollution of surface waters also carries significant weight. A novel new product, Carbond® P, is promising technology to increase P use efficiency. Research is needed to understand its capabilities and the functioning mechanisms imbedded within its technology. Several research studies were conducted to evaluate Carbond® P (CBP) against traditional fertilizers ammonium polyphosphate (APP) and monoammonium phosphate (MAP). A soil column leaching study was conducted to determine P mobility through three soils, at two rates (20 and 30 kg P ha-1) in either a banded or mixed soil application. Mobility of P was evaluated at 24, 48, 110 and 365 d after fertilization. CBP showed significantly greater total P leachate values across all soil types and application rates averaged across all readings taken until 365 daf for both application types. In the banded applications, CBP generally produced significantly greater solubility than MAP or APP up until 110 daf. For applications mixed with soil, CBP and MAP had greater solubility than APP at 24 days after application, but by the later evaluation dates (48 and 110 daf) the CBP was significantly higher than both MAP and APP. No statistical significance was found in the leachate P 365 daf in either the banded or mixed applications. One glasshouse study on maize (Zea mays L.) grown in three soils were conducted at 0, 5, 10, 20, 40, 80, and 160 kg P ha-1 comparing CBP and APP fertilizer impacts on early season growth. CBP produced significantly more biomass in two soils when averaged across rates (and at the 20 kg P ha-1 rate in a third soil), increased petiole P in one soil and thicker stems in another. Two field trials showed similar physiological advantages with CBP over APP at later growth stages. CBP maize responded with significantly more biomass and P uptake at the V12-V18 growth stages in one field, as well as plant height in another. At the R2-R3 growth stages, CBP also produced thicker stalks in both fields than APP. These growth enhancements were strongest in medium to highly calcareous soil (6-12 %) low in P (7 mg kg-1). These observations warrant the use of CBP and further investigation to understand its benefits and limitations.

In der vorliegenden Studie wurden zwei Fragestellungen bearbeitet, die beide das Ziel verfolgen, die Stickstoff(N)-Ausnutzungseffizienz in landwirtschaftlichen Systemen zu steigern: 1) Hat die langjährige organische Düngung einen Einfluss auf den Abbau kürzlich applizierter organischer Dünger? Die Hypothese war, dass relevante Effekte nur bei schwer abbaubaren organischen Düngern auftreten während bei leicht abbaubaren organischen Düngern die Düngungshistorie keine Rolle spielt. 2) Können die hohen N-Bilanzüberschüsse im intensiven Freilandgemüsebau durch den Einsatz von Winterzwischenfrüchten (ZF) deutlich reduziert werden? Die Hypothese war, dass ZF die Bilanzüberschüsse der betrachteten zweijährigen Fruchtfolgen um mindestens 30 kg N / ha reduzieren. Die erste Hypothese wurde überprüft, indem der Abbau organischer Dünger in Böden, die sich in ihrer organischen Düngungshistorie unterschieden, gemessen wurde. Es wurden ein Topfversuch im Gewächshaus sowie ein Inkubationsversuch im Labor durchgeführt. Die Ergebnisse deuteten darauf hin, dass es Effekte der Historie auf den Abbau von Stallmist und Kiefernrinde gab, während es keine Effekte bei leicht abbaubarem Kohlmaterial gab. Daher wurde die Hypothese angenommen. Allerdings ergaben die beobachteten Effekte kein konsistentes Bild in Hinblick auf die Richtung der Effekte auf die Kohlenstoff(C)- und N-Mineralisierung und Effekte auf die Netto-N-Mineralisation waren generell sehr klein. Zur Überprüfung der zweiten Hypothese wurden an drei Standorten in Deutschland Feldversuche mit Gemüsefruchtfolgen und unterschiedlichen ZF durchgeführt. Die Ergebnisse ergaben, dass trotz der die mittleren Bilanzüberschüsse der Kontrollen (ohne ZF) von 217 kg N / ha die ZF die N-Bilanz im Mittel um nur 13 kg N / ha reduzierten. Daher wurde die Hypothese abgelehnt. Die Ergebnisse zeigten weiterhin, dass der verlustfreie Transfer der von der ZF aufgenommenen N-Menge an die Folgefrucht ein kritischer Schritt bei dieser Technik ist.
The current study dealt with two questions that target potential options to increase the nitrogen (N) use efficiency of agricultural systems: 1) Does long-term organic fertilization affect the decomposition of recently added organic fertilizers? The hypothesis was that effects only occur for recalcitrant organic fertilizers while for readily decomposable organic fertilizers, the fertilization history does not play a role. 2) Can the N balance surpluses in intensive field vegetable production systems be substantially reduced by cultivation of winter catch crops (CC)? The hypothesis was that the N balance surpluses of the investigated two-year crop rotations can be reduced by more than 30 kg N / ha. The first hypothesis was tested by applying organic fertilizers to soils that only differed in organic fertilization history. A greenhouse pot experiment and a laboratory incubation experiment were conducted. The results indicated that fertilization history had effects on the decomposition of farmyard manure and pine bark, not however on the decomposition of readily decomposable cabbage material. Hence, the hypothesis was accepted in that fertilization history effects depended on the type of fertilizer. However, fertilization history effects showed no consistent trend with respect to increase or decrease in carbon (C) and N mineralization and the effects on net N mineralization were minor in magnitude. The second hypothesis was tested by performing field experiments at three sites in Germany. Vegetable crop rotations were set up, testing different types of CC. The results suggested that in spite of high N surpluses in the control treatments (no CC) of 217 kg N / ha, CC reduced the N balance surplus on average by only 13 kg N / ha. Hence, the hypothesis was rejected. The findings further indicated that the transfer of N taken up by the CC to the succeeding crop is a critical step when adopting this technique.

We study, using the non-parametric data envelopment approach, we investigated the long-run profit efficiency dynamics and the short-run market reaction of nine pre-classified merger deals of merging and non-merging U.S. banks over the time period from 1992 to 2003. Our main results are as follows: First, merger deals that match least efficient acquirers with the least efficient targets could improve their profit efficiency four years following the merger event, unlike all other merger deals. Second, we find that mergers match least efficient acquirers with the least efficient targets could also achieve significant positive cumulative access returns (CARs) while all other deals were followed by significant negative CARs. Third, we find that, in general, that large-size acquirers have and maintain higher and efficiency scores than targets and non-merging banks. Fianally, the value-maximizing mergers are mostly large in size and match banks with clear chances to increase their future efficiency rankings.

Although efficient use of stock is an important issue of housing economics and policies, there is very little research on the subject in Turkey. This study aims to investigate the stock efficiency in Turkey by measuring the degree to which the housing stock matches household size. Distributions between dwelling units and the households in terms of their size are investigated for this purpose. The stock is studied within three zones of occupational density: comfort, overcrowding and underoccupation, according to international occupancy standards. The findings reveal that the rapid rise in underoccupation in the stock is the dominant character of housing in Turkey, which is a result of housing system producing larger and larger dwellings despite the declining average household size in the country. The analyses in the province center level show that there are great differences between the western and eastern parts of the country. Reasons of overcrowding and underoccupation are also investigated by means of regression analysis. Tenure, income level and proportion of gecekondu emerge as the most effective variables in explaining the differentiation of overcrowding and underoccupation across province centers.

Assessing On-Farm Irrigation Water Use Efficiency in Southern Ontario In southern Ontario, irrigation is essential for high value horticultural crop production to overcome insufficient rainfall and achieve stabilized crop production. In a context where competition for limited water resources intensifies due to the expansion of the agricultural sector, increasing urban development and tourism, and potential climate change impacts, conserving water through efficient irrigation has become a key solution to address this growing challenge. The implementation of advanced soil water monitoring technologies and water budgeting for improved irrigation scheduling is explored to conserve water and thus cope with increasing competing demands for limited water supplies. Soil moisture was measured by gravimetric sampling in conjunction with several modern soil water sensors over the course of the 2007 growing season at 15 field sites located in southern Ontario where high value horticultural crop production is predominant. Quantities of irrigation water used were measured by flow meters that were installed at three of these sites. In addition, two grower surveys were administered: the first to collect information on current irrigation scheduling practices, and another to determine the appropriateness of the soil moisture monitoring sensors. On-farm irrigation performance was assessed by comparing calculated crop water requirements (using the water budget method) with growers' estimates of irrigation water use with soil moisture measurements taken during the growing season. In five out of six experimental zones, water was either excessively or insufficiently applied. In
Évaluation de l'Efficacité d'Utilisation de l'Eau d'Irrigation à l'Échelle de la Ferme dans le Sud de l'Ontario Dans le sud de l'Ontario, l'irrigation est essentielle à la production de cultures horticoles à haute valeur ajoutée afin de compenser l'insuffisance de précipitations et stabiliser la production de cultures. Dans un contexte où la compétition pour les ressources limitées en eau s'intensifie en réponse à l'expansion du secteur agricole, à la croissance du développement urbain et du tourisme, ainsi qu'aux impacts potentiels des changements climatiques, conserver l'eau grâce à des techniques d'irrigation économes est devenue une solution incontournable pour affronter ce défi grandissant. L'implémentation de technologies avancées de surveillance de la teneur en eau dans le sol et d'un bilan hydrique, pour améliorer les pratiques d'irrigation programmée, est explorée afin de conserver l'eau et ainsi mieux faire face à l'augmentation concurrentielle des demandes pour les ressources limitées en eau. Au cours de la saison de croissance de 2007, l'humidité du sol a été mesurée avec plusieurs sondes ainsi que par la méthode gravimétrique pour quinze sites situés dans le sud de l'Ontario où la production de cultures à haute valeur ajoutée est prédominante. Les quantités d'eau utilisées pour irriguer étaient mesurées par des compteurs de débit installés dans trois des quatre sites. De plus, les producteurs ont répondus à deux questionnaires: le premier visant à recueillir l'information concernant des pratiques actuelles d'irrigation programmée et le second à déterminer l'utilité des sondes mesurant l'humidité du sol. La

La sequera és una de les majors limitacions per a l’agricultura en general, factor que pot incrementar d’acord amb les prediccions del canvi climàtic. Per això, reduir l’ús de l’aigua en el reg i augmentar l’eficiència en l’ús de l’aigua (EUA) constitueix una de les majors prioritats per aconseguir una agricultura sostenible. L’EUA és un balanç entre guanys de biomassa i les despeses d’aigua. Aquesta Tesi s’ha centrat en l’estudi de 3 dels processos fisiològics que afecten a l’ús de l’aigua i a la producció de la planta en el cas de la vinya, i que per tant poden ser considerats factors potencials per millorar l’EUA: (1) conductància del mesòfil, (2) transpiració nocturna (3) respiració. Els resultats d’aquesta Tesi revelen que la conductància del mesòfil i la respiració són els principals components per millorar l’EUA permetent millorar l’assimilació de carboni o minimitzant les pèrdues del carboni fixat per la fotosíntesis

The annual and seasonal water use efficiency of six pasture combinations were calculated from the ‘MaxClover’ Grazing Experiment at Lincoln University. Pastures have been established for six years and are grazed by best management practices for each combination. Measurements for this study are from individual plots of four replicates of ryegrass (RG)/white clover (Wc), cocksfoot (CF)/Wc; CF/balansa (Bal) clover; CF/Caucasian (Cc) clover; CF/subterranean (Sub) clover or lucerne. Water extraction measurements showed soils for all dryland pastures had a similar plant available water content of 280±19.8 mm. Dry matter measurements of yield, botanical composition and herbage quality were assessed from 1 July 2008 until 30 June 2009. Lucerne had the highest annual yield of 14260 kg DM/ha/y followed by the CF/Sub at 9390 kg DM/ha/y and the other grass based pastures at ≤ 6900 kg DM/ha/y. All pastures used about 670±24.4 mm/y of water for growth. Lucerne had the highest annual water use efficiency (WUE) of 21 kg DM/ha/mm/y of water used (total yield/total WU). The WUE of CF/Sub was the second highest at 15 kg DM/ha/mm/y, and the lowest was CF/Wc at 9 kg DM/ha/mm/y. The CF/Sub pastures had the highest total legume content of all grass based pastures at 21% and as a consequence had the highest annual nitrogen yield of 190 kg N/ha. This was lower than the monoculture of lucerne (470 kg N/ha). Ryegrass/white clover had the highest total weed component in all pastures of 61%. For dryland farmers spring is vital for animal production when soil temperatures are rising and moisture levels are high. The water use efficiency at this time is important to maximize pasture production. In spring lucerne produced 8730 kg DM/ha, which was the highest dry matter yield of all pastures. The CF/Sub produced the second highest yield of 6100 kg/DM/ha. When calculated against thermal time, CF/Sub grew 5.9 kg DM/ºCd compared with lucerne at 4.9 kg DM/ºCd. The higher DM yield from lucerne was from an extra 400 ºCd of growth. The highest seasonal WUE of all pastures occurred in the spring growing period. Linear regressions forced through the origin, showed lucerne (1/7/08-4/12/08) had a WUE of 30 kg DM/ha/mm (R2=0.98). Of the grass based pastures, CF/Sub produced 18 kg DM/ha/mm (R2=0.98) from 1/7 to 10/11/08 from 270 mm of water used. The lowest spring WUE was 13.5 kg DM/ha/mm by CF/Bal pastures which was comparable to the 14.3±1.42 kg DM/ha/mm WUE of CF/Wc, CF/Cc and RG/Wc pastures. During the spring, CF/Sub clover had the highest spring legume component of the grass based pastures at 42% and produced 120 kg N/ha. This was lower than the 288 kg N/ha from the monoculture of lucerne. Sub clover was the most successful clover which persisted with the cocksfoot. Based on the results from this study dryland farmers should be encouraged to maximize the potential of lucerne on farm, use cocksfoot as the main grass species for persistence, rather than perennial ryegrass, and use subterranean clover as the main legume species in cocksfoot based pastures. By increasing the proportion of legume grown the water use efficiency of a pasture can be improved. When pastures are nitrogen deficient the use of inorganic nitrogen may also improve pasture yields particularly in spring.

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Nesta dissertação é proposto um novo método para a avaliação da eficiência de uso do espectro a ser aplicado para os sistemas de telecomunicações pontoárea, incluindo radiodifusão, e ponto-a-ponto. A definição proposta para o índice de eficiência é baseada nos aspectos técnicos, mas outros aspectos que podem influenciar na determinação da eficiência dos sistemas de telecomunicações, como os econômicos, sociais, políticos e estratégicos também são discutidos. O método é testado com dados reais de sistemas disponibilizados pela Anatel e no sítio dos prestadores de serviços de telecomunicações no Brasil. É muito importante avaliar a eficiência dos sistemas de telecomunicações, pois sendo o espectro de radiofreqüências um recurso limitado, pela tecnologia e capacidade de gerenciamento, a introdução de novos serviços de telecomunicações somente será possível com a substituição, pela realocação ou extinção, de determinadas aplicações menos eficientes. Apesar da regulamentação nacional e internacional constantemente referir-se à importância do uso eficiente das faixas de freqüências, não existe um método harmonizado de avaliação, o que impede a verificação deste aspecto pelos órgãos reguladores. As novas tecnologias e as oportunidades de desenvolvimento social que elas proporcionam demonstram a necessidade da boa gerência do espectro de radiofreqüências e de que cada uma de suas porções seja utilizada de forma eficiente e adequada a cada tipo de aplicação.
In this work a new method for the assessment of the spectrum use efficiency is proposed to be applied to point-area, including broadcasting, and point-to-point telecommunications systems. The proposed definition of the efficiency index is based in technical aspects, but other subjects that affect the determination of a telecommunications system efficiency, as economics, social, political and strategic issues are also discussed. The method is tested with data of real systems available from the Brazilian Regulatory Agency (Anatel) and at the telecommunications service providers web sites. It is very important to assess the telecommunications systems efficiency, because being the radio spectrum a scarce resource, limited by technology and management capacity, the introduction of new telecommunications services will only be possible by replacement, refarming or suppression of some less efficient applications. Despite national and international regulations usually refers to the importance of efficient use of the frequency bands, there is no harmonized assessment method to be applied and verified by the regulators. The new technologies and the opportunities for social development provided by them, bring to the light the need for a good radio spectrum management and how each part of it must be used efficiently and assigned properly for each type of application or telecommunications service.

Rice, as a major staple crop, is one of the most important targets for plant breeders in an attempt to secure enough food for a growing world population. Producing nutrient efficient crops has become essential not only to attempt securing enough food for the growing population, but also to eliminate environmental consequences of using fertilizers. Nitrogen (N), phosphorus (P) and potassium (K) are major macronutrients that are rate limiting for plant growth and crop productivity. The aims of this project were to explore the genetic diversity of rice to identify genotypes with high efficiency under N, P and K deficient conditions, to identify chromosomal loci linked to NPK use efficiency using Genome Wide Association Studies (GWAS), and to manipulate a proton pump using CRISPR/Cas9 system with the aim of improving mycorrhiza-dependent nutrient uptake. Biomass and elemental analyses revealed considerable variations among 294 rice genotypes, and a subset of genotypes was identified that were relatively tolerant to NPK nutrient limitation. GWAS study revealed novel and previously known QTLs and genes with potential importance to the use efficiency of N, P and K. Alongside with N and K transporters and regulatory proteins, unexpectedly several genes involved in Na transport were identified as candidates. The CRISPR/Cas9 system was successfully applied to manipulate several candidate genes identified from GWAS, in addition to the rice H+-ATPase (OsHA1). Overall, the findings from this study can be used as a basis to conduct similar studies in other crops, which can all contribute to improve crop production, sustainable agriculture and food security.

Water use efficiency (WUE), measured as the ratio of plant biomass to water consumption, is an essential agronomical trait for enhancing crop production under drought. Measuring water consumption is logistically difficult, especially in field conditions. The general objective of the present Thesis is to respond to three main questions: (i) can WUE be determined by using carbon isotope discrimination (CID), easy to measure?, (ii) how WUE and CID variation analysis can contribute to the genotypic selection of sunflower subjected to drought?, and (iii) can WUE variation be revealed by the variation of plant-water relation traits. Four experiments were carried out in greenhouse across two different years: (i) on two drought scenarios, progressive soil drying and stable water-stress, and (ii) on five levels of soil water content. The main traits that have been measured include WUE, CID, as well as plant-water relation traits, i.e. control of transpiration (FTSWt), water extraction capacity (TTSW), and dehydration tolerance (OA). A highly significant negative correlation was observed between WUE and CID, and a wide phenotypic variability was observed for both WUE and CID. A wide variability was also observed for FTSWt, TTSW and OA. The results provide new insight into the genetic control of WUE and CID related-traits, which, unlike to other crops, genetic control of WUE, CID, and TTSW in sunflower have never been reported in the literature. Further, quantitative trait loci (QTL) mapping for FTSWt was never reported in any plant species. The QTL for WUE and CID were identified across different drought scenarios. The QTL for CID is considered as a ‘‘constitutive’’ QTL, because it is consistently detected across different drought scenarios. The QTL for CID co-localized with the QTL for WUE, biomass and cumulative water transpired. Co-localization was also observed between the QTL for FTSWt and TTSW, between the QTL for TTSW and WUE-CID-biomass, as well as between the QTL for FTSWt-TTSW and biomass. This study highlights that WUE is physiologically and genetically associated with CID. CID is an excellent surrogate for WUE measurement, and can be used to improve WUE by using marker-assisted selection (MAS) to achieve the ultimate goal of plant breeding at genomic level.

There is only sparse published evidence on the behaviour of the prices of traded financial options in the UK. This thesis addresses this void in the literature by investigating several aspects of index options pricing on the London market. The efficiency of the market is tested directly by means of an event study based on the 1992 UK general election, and indirectly by examining the predictive power of the implied volatility from options. The option market appears less efficient than the stock market in its response to the public information from opinion polls, but does appear to have become more efficient since the previous election. Implied volatility is found to be inferior to historical volatility as a forecast of realised volatility over the remaining life of the option. Several other properties of implied volatility are also discussed, including the smile, the term structure and behaviour around expiry days. Forward/forward volatility is also examined as a measure of the market's expectation of future volatility. The behaviour of the underlying asset around option expiry days is also examined. The final two parts of this study offer a particular contribution by examining patterns in bid-ask spreads, returns and volatility on an intraday basis. The intraday patterns in bid-ask spreads differ slightly from the evidence from stock markets, and market structure is identified as a possible reason. The time of day return patterns reported for stock markets and US options markets are generally not replicated for the UK options market. However, a U-shaped intraday pattern in volatility is consistent with previous work.

Disaster events have emphasized the importance of healthcare response activities due to the large number of victims. For instance, Hurricane Katrina in New Orleans, in 2005, and the terrorist attacks in New York City and Washington, D.C., on September 11, 2001, left thousands of wounded people. In those disasters, although hospitals had disaster plans established for more than a decade, their plans were not efficient enough to handle the chaos produced by the hurricane and terrorist attacks. Thus, the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) suggested collaborative planning among hospitals that provide services to a contiguous geographic area during mass casualty disasters. However, the JCAHO does not specify a methodology to determine which hospitals should be included into these cooperative plans. As a result, the problem of selecting the right hospitals to include in exercises and drills at the county level is a common topic in the current preparedness stages. This study proposes an efficiency index to determine the efficient response of cooperative-networks among hospitals before an occurrence of mass casualty disaster. The index built in this research combines operations research techniques, and the prediction of this index used statistical analysis. The consecutive application of three different techniques: network optimization, data envelopment analysis (DEA), and regression analysis allowed to obtain a regression equation to predict efficiency in predefined hospital networks for mass casualty disasters. In order to apply the proposed methodology for creating an efficiency index, we selected the Orlando area, and we defined three disaster sizes. Then, we designed networks considering two perspectives, hub-hospital and hub-disaster networks. In both optimization network models the objective function pursued to: reduce the travel distance and the emergency department (ED) waiting time in hospitals, increase the number of services offered by hospitals in the network, and offer specialized assistance to children. The hospital network optimization generated information for 75 hospital networks in Orlando. The DEA analyzed these 75 hospital networks, or decision making units (DMU's), to estimate their comparative efficiency. Two DEAs were performed in this study. As an output variable for each DMU, the DEA-1 considered the number of survivors allocated in less than a 40 miles range. As the input variables, the DEA-1 included: (i) The number of beds available in the network; (ii) The number of hospitals available in the network; and (iii) The number of services offered by hospitals in the network. This DEA-1 allowed the assignment of an efficiency value to each of the 75 hospital networks. As output variables for each DMU, the DEA-2 considered the number of survivors allocated in less than a 40 miles range and an index for ED waiting time in the network. The input variables included in DEA-2 are (i) The number of beds available in the network; (ii) The number of hospitals available in the network; and (iii) The number of services offered by hospitals in the network. These DEA allowed the assignment of an efficiency value to each of the 75 hospital networks. This efficiency index should allow emergency planners and hospital managers to assess which hospitals should be associated in a cooperative network in order to transfer survivors. Furthermore, JCAHO could use this index to evaluate the cooperating emergency hospitals* plans. However, DEA is a complex methodology that requires significant data gathering and handling. Thus, we studied whether a simpler regression analysis would substantially yield the same results. DEA-1 can be predicted using two regression analyses, which concluded that the average distances between hospitals and the disaster locations, and the size of the disaster explain the efficiency of the hospital network. DEA-2 can be predicted using three regressions, which included size of the disaster, number of hospitals, average distance, and average ED waiting time, as predictors of hospital network efficiency. The models generated for DEA-1 and DEA-2 had a mean absolute percent error (MAPE) around 10%. Thus, the indexes developed through the regression analysis make easier the estimation of the efficiency in predefined hospital networks, generating suitable predictors of the efficiency as determined by the DEA analysis. In conclusion, network optimization, DEA, and regressions analyses can be combined to create an index of efficiency to measure the performance of predefined-hospital networks in a mass casualty disaster, validating the hypothesis of this research. Although the methodology can be applied to any county or city, the regressions proposed for predicting the efficiency of hospital network estimated by DEA can be applied only if the city studied has the same characteristics of the Orlando area. These conditions include the following: (i) networks must have a rate of services lager than 0.76; (ii) the number of survivors must be less than 47% of the bed capacity EDs of the area studied; (iii) all hospitals in the network must have ED and they must be located in less than 48 miles range from the disaster sites, and (iv) EDs should not have more than 60 minutes of waiting time. The proposed methodology, in special the efficiency index, support the operational objectives of the 2012 ESF#8 for Florida State to handle risk and response capabilities conducting and participating in training and exercises to test and improve plans and procedures in the health response.
Ph.D.
Doctorate
Industrial Engineering and Management Systems
Engineering and Computer Science
Industrial Engineering

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2008.
Includes bibliographical references (leaf 43).
The paper aims to investigate the improvement that Ridge regression brings to the commercial real estate index estimation. The MIT transaction based index extends the use of the last model by Fisher, Gatzlaff, Geltner and Haurin (2003.) They address the sample selection bias and the noise effect of the transaction prices in small sample. To correct sample selection bias, MIT transaction index use the Heckman two-step. In addition to the correction of sample selection bias the MIT transaction based index applies the Ridge filters into the index creation procedures to dampen the effect of noise in transaction prices on estimations. Among them, this paper primarily focuses on: (1) investigating error structures, defined by the difference between the true market return and the estimated index return; (2) examining the efficiency improvement of the Ridge Regression as estimation method over Ordinary Least Square (OLS); (3) selecting the proper value of weight factor "k." The findings on the error structures are as follows. First, MIT transaction index does not suffer from smoothing and lagging which is apparent in the appraisal based index. Second, with larger sample size, the estimated market indexes become close to the true market values. In addition, the estimated market index is more biased when it uses small number of sample. Third, the error does not cumulate over time regardless of the sample size. To correct noise effect on the estimation procedure under the observation poor scenario, this study examines the efficiency of the Ridge regression. First, we examine the qualitative form of relationship between ridge coefficients and the control factor of "k." Generally, ridge trace is not significantly changed with respect to "k." It might be argued that the noise effect is not severe in the estimation procedure, yet the introduction of ridge regression apparently improves the estimation. Indeed, between k =4 and 5 ridge coefficients stabilize. Second, to investigate the improvement of ridge regression, we examine the mean square error.
(cont.) Between k = 4 and 5, mean square error, defined by the difference between the true and estimated market index, achieve the lowest value. Taken together, the system stabilizes between k = 4 and 5 and achieve the minimum mean squared error. This result leads to the conclusion that we can obtain better estimation using the control factor of 5.
by Jungsoo Park.
S.M.

Doctor of Philosophy
Department of Agricultural Economics
Allen M. Featherstone
This dissertation focuses on measuring the efficiency and productivity for agricultural cooperatives in the United States using the data envelopment analysis (DEA) approach. Economic measures such as cost efficiency, economies of scale, and economies of scope are measured by estimating a cost frontier in a multiproduct framework. Productivity growth is measured using the biennial Malmquist index approach. The cost frontier is the basis for calculating cost efficiency, economies of scale, and economies of scope as the cost frontier estimation in a multiproduct approach describes how cost changes as output changes. The estimates of economies of scale and scope have important implications for agricultural cooperatives because most of the cooperatives sell more than one product. Understanding the impact of changing output levels or mixes on the cost structure is helpful to improve the performance of cooperatives. Further, scope economies estimate the percentage of cost savings through product diversification in a multiproduct firm. The trade-off between cost efficiency and multiproduct scale economies allows the estimation of whether a higher percentage of cost can be eliminated by becoming cost efficient or changing the scale of operations. The economic measures are estimated using a single cost frontier (multi-year frontier) and annual cost frontiers. Multiproduct economies of scale and economies of scope exist indicating that increasing scale and product diversification can reduce cost for agricultural cooperatives. The mean values of product-specific economies of scale for all outputs are close to one indicating that cooperatives are operating close to constant returns to scale. The comparison between cost efficiency and scale economies suggests that smaller cooperatives can save a higher percentage of cost by increasing the scale of operations rather than just becoming cost efficient. Because larger incentives exist for small cooperatives to increase scale, mergers will likely continue until economies of scale are exhausted in the industry. Annual estimates show that agricultural cooperatives have become less cost efficient over time, but economies of scale and economies of scope remain consistent across years. Many agricultural cooperatives face economies of scale indicating that variable returns to scale as opposed to constant returns to scale is the appropriate technology for modeling agricultural farm marketing and supply cooperatives. Further, the Kolmogorov-Smirnov (KS) test and two sample t-test are used to examine whether economic measures estimated from a single frontier and annual frontiers are statistically different. The KS test and t-test indicate that economic measures obtained from the single frontier are statistically different from those measures calculated from annual frontiers. This indicates that the cost frontier has shifted over time. Productivity growth of agricultural cooperatives is estimated using the biennial Malmquist productivity index (BMI) under variable returns to scale over the period 2005 to 2014. The BMI avoids numerical infeasibilities under variable returns to scale compared to traditional methods. The BMI is decomposed into efficiency change and technical change to evaluate the sources of productivity growth. Overall, agricultural cooperatives gained 34% cumulative productivity growth during the decade allocated by -2% and 37% cumulative technical efficiency change and technical change over the study period. Technical change was the major source of productivity growth rather than efficiency change. Cooperatives can achieve higher productivity by increasing managerial efficiency and by investing in technology.

Electric end-use efficiency is attracting more and more attentions, but it remains unclear what factors are driving state policy innovations to improve energy efficiency. Controversy also exists over the effectiveness of energy efficiency programs. Several critical problems are facing the policymakers: what factors drive the states taking distinct strategies in policy innovation? Have state policies being able to improve energy efficiency in the past? And, will state policies remain relevant to future efficiency improvements? This dissertation tries to answer these important questions and assumes that policy innovation is relevant to energy efficiency. It first explores the factors that influence the adoption of energy efficiency policies using Internal Determinants models. Results suggest that internal state factors affect policy innovation, including state socioeconomic factors, state fiscal capacity, ideology, and constituent pressure. Policy innovations are found to be correlated with each other. This dissertation also evaluates the impact of policy innovation on energy efficiency by decomposing electricity productivity into activity, structure, and efficiency effects. The findings suggest that financial incentives and building codes have significant impacts on state electricity productivity. Other regulations tend to have mixed effects. In addition, an estimation of the achievable potential of energy efficiency suggests that policies will cost-effectively drive significant electricity savings in the future. Overall, this dissertation offers an in-depth diagnosis of the relationship between policy innovation and energy efficiency. It provides a rigorous statistical analysis covering the most important energy efficiency policies. It represents the first attempt to evaluate policy impact by decomposing electricity productivity. However, the statistical models and energy models are subject to limitations and future research is needed to improve the models.

This dissertation consists of three essays. The first essay studies the impact of indexing on stock price efficiency. Indexing has experienced substantial growth over the last two decades because it is an effective way of holding a diversified portfolio while minimizing trading costs and taxes. In this paper, we focus on one negative externality of indexing: the effect on efficiency of stock prices. Based on a sample of large and liquid U.S. stocks, we find that greater indexing leads to less efficient stock prices, as indicated by stronger post-earnings-announcement drift, greater deviations of stock prices from the random walk and greater return predictability from lagged order imbalances. We conjecture that reduced incentives for information acquisition and arbitrage induced by indexing are probably the main cause of the degradation in price efficiency, but we find no evidence supporting a direct impact from passive trading or any effect through liquidity. The second essay investigates the effect of price inefficiency on idiosyncratic risk and stock returns. I finds that price inefficiency in individual stocks contributes to expected idiosyncratic volatility. If idiosyncratic risk is priced, greater price inefficiency could be associated with higher expected returns. Consistent with this hypothesis, this paper then finds a positive relation between price inefficiency and future stock returns. This return premium of price inefficiency is not explained by traditional risk factors, illiquidity, or transactions costs. It is also evidently different from the return bias related to Jensen's inequality. This paper thus provides new insights about the determinants of expected stock returns, and new supporting evidence that idiosyncratic risk is priced. The third essay examines whether the upward return bias generated by Jensen's inequality could lead to better performance of equally-weighted (EW) indexes than value-weighted (VW) index when stock prices are not fully efficient. We find that, for a wide range of U.S. stock indexes, EW indexes deliver better four-factor adjusted returns than VW ones do even after deducting transaction costs. Consistent with our hypothesis that the outperformance of EW indexes comes from mispricing, we find that this outperformance concentrates in stocks with greater mispricing, as measured by deviation of stock prices from random walk. Findings in this essay not only imply a potentially winning investment strategy, but also provide new insight into a long-term debate on causes of the outperformance of the EW indexes.
Ph. D.

Thesis (Honors)--Ohio State University, 2007.
Title from first page of PDF file. Document formatted into pages: contains 11 p.; also includes graphics. Includes bibliographical references (p. 11). Available online via Ohio State University's Knowledge Bank.

Nitrogen use efficient (NUE) wheat varieties have potential to reduce input costs for growers, limit N runoff into water ways, and increase wheat adaptability to warmer environments. Previous studies have done little to explain the genetic basis for NUE and components, nitrogen uptake efficiency (NUpE) and nitrogen utilization efficiency (NUtE). Four studies were conducted to 1) determine genotypic stability of NUE under high and low N regimes and under warming 2) determine effect of warming on NUE 3) indentify QTL associated with NUE components 4) assess the utility of canopy spectral reflectance (CSR) as a high-throughput phenotyping device for NUE. Genotypic response to N stress or warming varied. Uptake efficiency was found to be more important than utilization efficiency to genotypic performance under high and low N environments and under warming. Selection under low N for NUpE and under high N for NUtE most efficiently identified NUE varieties. Uptake and utilization were lower under warming due to quickened development. No strong correlations between the CSR indices and NUE existed. No QTL were found to be significantly associated with NUE components. Further research into the mechanisms controlling NUE and to reveal plant response to N stress and under warming is necessary.

Crop water requirements are important elements for food production, especially in arid and semiarid regions. These regions are experience increasing population growth and less water for agriculture, which amplifies the need for more efficient irrigation. Improved water use efficiency is needed to produce more food while conserving water as a limited natural resource. Evaporation (E) from bare soil and Transpiration (T) from plants is considered a critical part of the global water cycle and, in recent decades, climate change could lead to increased E and T. Because energy is required to break hydrogen bonds and vaporize water, water and energy balances are closely connected. The soil water balance is also linked with water vapour losses to evapotranspiration (ET) that are dependent mainly on energy balance at the Earth’s surface. This work addresses the role of evapotranspiration for water use efficiency by developing a mathematical model that improves the accuracy of crop evapotranspiration calculation; accounting for the effects of weather conditions, e.g., wind speed and humidity, on crop coefficients, which relates crop evapotranspiration to reference evapotranspiration. The ability to partition ET into Evaporation and Transpiration components will help irrigation managers to find ways to improve water use efficiency by decreasing the ratio of evaporation to transpiration. The developed crop coefficient model will improve both irrigation scheduling and water resources planning in response to future climate change, which can improve world food production and water use efficiency in agriculture.

The diploma thesis provides basic characteristics of short rotation coppice plantations, then the most significant short rotation coppice species cultivated in the Czech Republic are described. The detailed description of particular Populus L. clone J-105 grown at the plantation of the Test Station Domanínek Ltd. follows. Afterwards, key determinants of short rotation coppice yield are presented in the text. The last theoretical part of the thesis deals with water use efficiency (WUE) with emphasis on the method used at the experimental plantation in Domanínek. The methods of sap flow measurements and biomass determinations are described for this purpose. The main aim of the practical part of the thesis is to determine WUE of 16 measured trees where sap flow measuring systems were installed. These trees are divided into 3 cohorts according to diameters at breast height (DBH) at the beginning of the growing season 2013. The additional measurements were carried out: phenological imaging, soil moisture measurements, LAI measurements and sapwood area determination. The statistical analysis of WUE did not show any statistically significant differences between values of WUE for individual cohorts. Only in May, the statistically significant difference between cohort 1 (trees with the thickest stems) and cohort 3 (trees with the lowest values of DBH) appeared.

The expansion of livestock husbandry and biogas production in large parts of northwestern Germany during the last two decades increased the amount of accruing manure, as well as the demand for maize as fodder crop and substrate for biogas plants. To overcome phosphorus deficiency symptoms during early growth of maize, farmers commonly apply mineral starter fertilizers containing ammonium-nitrogen and phosphorus on top of the usual manure applications required to meet crop nutrient demand. This practice typically leads to overfertilization of N and P and the excess nutrients are then prone to be lost into the environment. Recent developments of agricultural machinery allow for the injection of slurry bands into the soil prior to maize planting. Due to high concentrations of ammonium and phosphorus in the manure band, chemical transformation and translocation of these nutrients is reduced. When the bands are placed near the seeds, even the radicles can access the applied nutrients. Hence, application of mineral starter fertilizers might be obviated. Earlier investigations showed insufficient knowledge of nutrient transformations in manure bands and their consequences on crop growth. To resolve these problems a research project at the University of Applied Sciences Osnabrück was conducted in close cooperation with the local agricultural extension services, machinery producers and farmers. In a series of field trials, broadcasting of liquid manure was compared to injection with and without a nitrification inhibitor in three consecutive growing seasons (2013 to 2015). The trials were conducted in a split-plot design, where all liquid manure treatments were divided in subplots with and without a mineral starter fertilizer. Biomass samplings at eight leaves stage and harvest gave insight into the performance of the treatments. Compared to broadcast application with starter fertilizer, manure injection showed slightly retarded early growth in some trials. However, yields and nitrogen uptake at harvest were similar. When a nitrification inhibitor was added to the injected manure, early growth was not retarded, yields were alike broadcast and injection treatments, but nitrogen uptake was higher in all seasons (on average ~7%). To further investigate nitrogen dynamics and crop growth, another field trial was conducted on a sandy soil close to Osnabrück in 2014 and 2015. Manure injection with and without a nitrification inhibitor was compared to broadcast application with mineral starter fertilizer and an unfertilized control treatment. Plant samplings were taken at regular intervals. Major precipitation events in May and June 2014 led to significant nitrate leaching, especially in the broadcast treatment. Manure injection delayed the nitrification of slurry ammonium and consequently the translocation out of the root zone. Thus, plants in injection treatments could accumulate more nitrogen in their biomass and showed less nitrogen deficiency symptoms. This led to increased yield (+16.5%) and nitrogen uptake (+9.6%) for injection treatment with nitrification inhibitor compared to broadcast treatment. In 2015, low temperatures impaired seminal root growth and phosphorus availability. The mineral starter fertilizer in the broadcast treatment led to better early growth than injected slurry. When a nitrification inhibitor was added to the injected manure, less P deficiency symptoms were observed, and the crop growth was only slightly retarded. Due to the high compensation potential of silage maize, these differences were equalized until harvest. Nevertheless, the mean apparent nitrogen recovery efficiency of both seasons was higher in injection treatments with and without nitrification inhibitor, compared to broadcast with mineral starter fertilizer (48%, 56% and 43%, respectively). To ease the handling of field trial series by decreasing the number of tissue samplings, the use of a handheld sensor was tested during vegetative growth of maize. In the series of field trials with the local extension service, the derived vegetation index showed significant correlations to biomass and nitrogen uptake at eight leaves stage. Measurements of the vegetative growth observed during the nitrogen dynamics trial showed that the sensor needs sufficient leaf area to deliver precise data, but also tends to saturate when maize tassels evolve. The best estimates were found between six and ten leaves. Thus, the sensor can be a valuable tool to reduce numbers of tissue samples and, thus, time and effort needed in fertilization trials. Altogether, these results should encourage farmers to obviate mineral starter fertilizers by using manure injection when cropping maize on sandy soils. The advantages that come along with manure injection based on the present research indicate higher shares of manure nutrients find their way into the plants due to delayed biochemical transformations. These nutrients are consequently not lost into the environment. Nitrification inhibitors have shown a positive effect on crop performance and led to a further reduction of nitrogen losses. However, further knowledge of their decomposition with special regard to the ecological impact of their compounds and metabolites need to be thoroughly evaluated.