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Gay, Alanis Leon F. "Measuring Energy Efficiency of Water Utilities." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/34231.
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Water infrastructure systems worldwide use large amounts of energy to operate. Energy efficiency efforts are relevant because even relatively small gains in efficiency have the potential to bring significant benefits to these utilities in terms of financial savings and enhanced sustainability and resiliency. In order to achieve higher efficiency levels, energy usage must be measured and controlled.
A common tool used to measure energy efficiency in water utilities and perform comparisons between utilities is metric benchmarking. Energy benchmarking scores are intended to measure how efficient water systems are among their peers, in a simple and accurate fashion. Although many different benchmarking methods are currently used, we chose to use the segregated benchmarking scores proposed by Carlson on his research report from 2007 (Carlson, 2007).
The research objective is to improve these production energy use and treatment energy use benchmarking scores by analyzing the systemâ s particular characteristics that might skew the results, such as topology, water loss and raw water quality. We propose that benchmarking metrics should be always used within a particular context for each specific utility being analyzed. A complementary score (Thermodynamic Score) was developed to provide context on how energy efficient is the utility not only compared with other utilities, but also compared with the potential maximum efficiency the utility can reach itself.
We analyzed eight utilities from Virginia to obtain production and treatment energy use benchmarking scores and also thermodynamic scores using the minimum required energy approach. Benchmarking scores were skewed in 50% of the studied utilities. This means that benchmarking scores should never be used as a black box. The thermodynamic score proved to be useful for measurement of energy efficiency of a water utility on its production phase. In addition, some utilities can detect significant financial saving opportunities using the minimum required energy analysis for production operations.<br>Master of Science
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Lindner, Björn. "The black water loop : water efficiency and nutrient recovery combined /." Hamburg : GFEU, 2008. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=016561528&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Gurung, Thulo Ram. "Influence of Water Efficiency and Diversified Water Supply Schemes on Urban Water Infrastrucrure Planning." Thesis, Griffith University, 2015. http://hdl.handle.net/10072/367485.
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Water security is increasingly becoming a cause of concern in Australia with population growth and climate change set to exacerbate the variability of supply in both rural and urban regions. During recent drought conditions in Queensland there was a strong emphasis on water restrictions to reduce residential consumption, as well as water policy strategies such as modifying building codes to require all new residential and commercial buildings to conserve and/or substitute potable water. Additionally, there was a heightened emphasis on having an Integrated Urban Water Management (IUWM) approach to water management.
IUWM involves the use of alternative water supplies and demand management practices to ensure a sustainable approach to water management by integrating both the demand and supply-based management approaches. Within Queensland, mandatory regulations required residents to save on household water consumption by using alternative water measures in order to offset mains (potable) demand. The installation of rainwater tanks and the reuse of greywater, connected to toilets, cold water laundry and outdoor use, were some approaches adopted by householders to achieve the water saving targets. In addition, current mandatory regulations require new households to install minimum efficient rated water appliances to contribute to water savings.<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>Griffith School of Engineering<br>Science, Environment, Engineering and Technology<br>Full Text
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Sedibe, Moosa Mahmood. "Optimising water use efficiency for crop production." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53541.
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Thesis (MScAgric)--University of Stellenbosch, 2003.<br>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.<br>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.
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Brettenny, Warren James. "Efficiency evaluation of South African water service provision." Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/14741.
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In recent years South Africa has experienced numerous service delivery protests. These protests are a result of the lack of delivery of basic services such as water and sanitation (amongst others). To address this, local governments have taken part in benchmarking initiatives (National Benchmarking Initiative, Municipal Benchmarking Initiative) and regulation programmes (BlueDrop,GreenDrop) in an effort to improve the quality of potable water and sanitation services. The latter of these focuses on the quality of the water services delivered and neither focus on the efficiency with which this delivery is achieved. This study uses both nonparametric (data envelopment analysis) aswell as parametric (stochastic frontier) methods to assess the efficiency of water service provision in South Africa over a six year period from 2005 to 2010. Subsequently, the method which is most suited for use in the South African context is proposed. In addition, this study demonstrates how these methods can be used to determine the effectiveness of benchmarking initiatives, namely the National Benchmarking Initiative, in improving the efficiency of water service provision. Furthermore, additional insight into the selection ofm in them out of n bootstrap procedure for efficiency evaluations is established through a simulation study. The inclusion of efficiency evaluations into South African benchmarking initiatives provides new and important insight into the standard of water service delivery. As such, the techniques used in this study illustrate how efficiency analysis can enhance benchmarking initiatives in South Africa.
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Sauer, Johannes. "The economics and efficiency of water supply infrastructure." Berlin Logos-Verl, 2005. http://deposit.ddb.de/cgi-bin/dokserv?id=2748306&prov=M&dok_var=1&dok_ext=htm.
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Morgado, dos Santos Ana Maria. "Plant factors influencing water use efficiency of wheat." Thesis, University of Reading, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434315.
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Joseph, Jyothis. "Improving Photovoltaic Panel Efficiency by Cooling Water Circulation." Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1404617/.
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This thesis aims to increase photovoltaic (PV) panel power efficiency by employing a cooling system based on water circulation, which represents an improved version of water flow based active cooling systems. Theoretical calculations involved finding the heat produced by the PV panel and the circulation water flow required to remove this heat. A data logger and a cooling system for a test panel of 20W was designed and employed to study the relationship between the PV panel surface temperature and its output power. This logging and cooling system includes an Arduino microcontroller extended with a data logging shield, temperature sensing probes, current sensors, and a DC water pump. Real-time measurements were logged every minute for one or two day periods under various irradiance and air temperature conditions. For these experiments, a load resistance was chosen to operate the test panel at its maximum power point. Results indicate that the cooling system can yield an improvement of 10% in power production. Based on the observations from the test panel experiments, a cooling system was devised for a PV panel array of 640 W equipped with a commercial charge controller. The test data logger was repurposed for this larger system. An identical PV array was left uncooled and monitored simultaneously to compare the effect of cooling, demonstrating that the cooled array provided up to an extra 132W or 20% of maximum power for sunny weather conditions. Future expansion possibilities of the project include automated water level monitoring system and water filtration systems.
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Fraser, Michael B. (Michael Brent). "Analyzing the operating efficiency of autonomous water vehicles." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/68838.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 29).<br>Power consumption is a huge limitation in the application of autonomous vehicles, making the need for efficient processes more important. A greater operating efficiency could extend the capabilities of missions by consuming less power and energy. This thesis analyzed the operating efficiency of a small, autonomous water craft. The results of the study showed that the most efficient operating condition is to run the vehicle at the bare minimum to require movement. Less current is drawn from the battery to rotate the propellers and a greater proportional thrust return when compared to the work requirements. It was not possible to measure all of the operating conditions due to the limitations of the device themselves.<br>by Michael B. Fraser.<br>S.B.
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Bandekar, Ashish. "Electrowet Coalescence Of Water Drops In Water-ULSD Dispersion." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1490898933759055.
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Adiredjo, Afifuddin Latif. "Water use efficiency in sunflower : Ecophysiological and genetic approaches." Phd thesis, Toulouse, INPT, 2014. http://oatao.univ-toulouse.fr/20177/1/adiredjo.pdf.
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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.
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Singh, Ajay. "Water and nitrogen use efficiency of corn (Zea mays L.) under water table management." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=116989.
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Drainage and water table management are essential for crop production in humid regions. Water table management not only increases crop yield, but also reduces nitrate leaching to water bodies. This study investigated the water and nitrogen use efficiency of corn under two water management conditions and three nitrogen fertilizer levels. The sap flow heat balance method was used to measure the daily water uptake of corn, over an extended period of the growing season. The impacts of climate change on grain corn and biomass yield in eastern Canada under tile drained conditions was also evaluated over a 30 year future period (2040 to 2069). The study was conducted at a field scale in 2008 and 2009 at St. Emmanuel, Quebec. The two water management conditions were: conventional drainage (FD), and controlled drainage with subirrigation (CD-SI). The three nitrogen (N) fertilizer treatments (low, medium, and high N) were applied in a strip across three blocks. The seasonal water balance indicated that the plants in the CD-SI plots had more water than required in the wet periods, despite the system automation, while the FD plots exhibited deficit water conditions. Water could be saved in the wet periods by better regulating water supplied by subirrigation. However, in dry years, the CD-SI system increased yield. The grain corn water use efficiency (WUE) for FD plots was 2.49 and 2.46 kg m-3, in 2008 and 2009, respectively. In these years, the grain WUE for CD-SI plots was 2.43 and 2.26 kg m-3. Water management treatments demonstrated significant difference (p < 0.05) in grain yields in 2009, at low and high nitrogen levels. However, at the medium nitrogen level, water management demonstrated no significant effect (p > 0.05) on grain yields. The two water treatments had no effect on the above-ground dry biomass yields in both years. Mean nitrogen use efficiency (NUE) of grain corn and biomass varied from 27 to 99 kg kg-1. Highest NUE (99 kg kg-1) was observed under low N (~120 kg N ha-1) and lowest NUE (41 kg kg-1) occurred in the high N (~260 kg N ha-1). This might be due to higher nitrogen losses due to leaching, residual nitrogen in the soil, and more denitrification in high N plots. The rate of plant water uptake measured by the sap flow method, varied from 3.55 to 5.11 mm d-1 from silking to full dent stage of corn growth. These rates were consistent with ETc calculated by the FAO-56 Penman-Monteith method (3.70 to 5.93 mm d-1) for both years. Although, silking is considered as a critical stage for corn growth, water demand was highest at the milk stage (45.63 to 59.80 mm). Transpiration during this stage constituted 10 to12% of the total water requirement of the corn for the season. The silking to full dent stage accounted for approximately 40% of the total water requirement of the crop. The STICS (JavaStics v1.0) crop model was used to examine the impacts of climate change, under the B1 emissions scenario, on corn yield from 2040-2069. The model was calibrated using 2008 field measured data, and then validated using the 2009 data set. Corn grain yield was underestimated by 1.5 to 2.6 Mg ha-1 for the two years of measurement. Total dry biomass was also underestimated by 0.9 to 2.6 Mg ha-1. Simulations for the B1 emissions scenario using synthetic weather data was run under the same crop conditions as in 2008. Tukey's studentized range (HSD) test of corn grain yield indicated that yields at high and low N, and high and medium N were different at the 95% confidence level. Grain and biomass production from 2040-2069 under B1 emissions scenario responded differently (p < 0.05) for the three N treatments. However, the Mann–Kendall test showed neither increasing nor decreasing trend (MK-stat > - 1.96) at a 95% confidence level.<br>Le drainage et la gestion de la nappe phréatique des parcelles agricoles permet non seulement d'augmenter la production des récoltes, mais aussi de réduire les pertes de nitrates par lessivage, qui contribue à leurs transferts vers les étendues d'eau. Cette étude a examiné l'efficacité d'utilisation de l'eau et de l'azote du maïs grain sous deux conditions de gestion de l'eau et trois niveaux d'application d'azote. Les facteurs climatiques jouent un rôle important dans la production du maïs-grain. Les impacts des changements climatiques sur les projections de maïs-grain et de la production de biomasse en sol drainé ont aussi été évalués pour l'est du Canada pour une période futur de 30 ans (2040 à 2069). L'étude a été accomplie à l'échelle du champ en 2008 et en 2009 à Saint Emmanuel au Québec. Les deux scénarios de gestion de l'eau étaient (a) le drainage conventionnel (FD) et (b) le drainage contrôlé combiné à l'irrigation souterraine (CD-SI). Les trois traitements d'azote (N) (dose faible, moyenne et élevée) ont été appliqués en bande sur trois blocs. L'efficacité d'utilisation de l'eau du maïs (WUE) pour les blocs en FD était de 2.49 kg m-3 et 2.46 kg m-3 en 2008 et 2009 respectivement. Pour ces années, L'WUE du maïs-grain pour les blocs en CD-SI était de 2.43 kg m-3 et de 2.26 kg m-3. Les traitements relatifs à la gestion de l'eau ont permis d'améliorer la production de rendement du maïs-grain significativement (p <0.05) en 2009, que cela soit avec des doses d'azotes basses ou élevées. Cependant, pour des doses intermédiaires, la gestion de l'eau n'a démontré aucun effet significatif (p> 0.05) sur les productions de maïs-grain. Les deux traitements relatifs à la gestion de l'eau n'ont eu aucun effet sur la production de biomasse sèche au-dessus du sol pour les deux années. L'efficacité moyenne de l'utilisation de l'azote (NUE) du maïs grain et de sa biomasse variait de 27 kg kg-1 à 99 kg kg-1. La plus haute NUE (99 kg kg-1) a été observée pour une dose de N faible (~120 kg N ha-1). La plus basse NUE (41 kg kg-1) s'est produite pour une dose de N élevée (~260 kg N ha-1). La consommation des plantes en eau mesurée par la méthode d'écoulement de la sève, vari de 3.55 mm d-1 à 5.11 mm d-1 pour la période de l'apparition des soies jusqu'à la croissance complète du maïs-grain. Ces taux sont en accord avec l'ETc calculée (3.70 mm d-1 à 5.93 mm d-1) pour les deux ans. Bien que, le développement de la soie soit considéré comme le stade critique pour le maïs-grain, la demande en eau fut la plus élevée lors du stade laiteux du développement du maïs (45.63 mm à 59.80 mm). À ce stade, 10 à 12% des besoins totaux de la plante en eau pour la saison furent transpirés. Du stade de la soie jusqu'au développement complet de l'épi de maïs les besoins en eau de la plante ont représenté environ 40 % de son besoin total. Le modèle de récolte STICS (JavaStics v1.0) a été utilisé pour examiner les effets du changement climatique sur la production de maïs- grain, de 2040 à 2069 et sous le scénario d'émissions de gaz à effet de serre B1. Le modèle a d'abord été calibré en utilisant les données mesurées au champ en 2008 et, a ensuite été validé avec l'ensemble des données de 2009. La production de maïs-grain est sous-estimée de 1.5 Mg ha-1 à 2.6 Mg ha-1 pour les deux ans de mesure. La biomasse sèche totale est aussi sous-estimée de 0.9 Mg ha-1 à 2.6 Mg ha-1. Les simulations pour le scénario d'émissions B1 en utilisant des données météorologiques synthétiques font été utilisées dans les mêmes conditions de récolte que 2008. Les prédictions de la production de maïs-grain et de sa biomasse pour la période 2040-2069 sous le scénario d'émissions B1 sont différentes (p <0.05) selon les trois traitements de N. Cependant, l'épreuve de Mann-Kendall n'a montré aucune tendance à la hausse ou à la baisse (MK-stat> - 1.96) pour un niveau de confiance de 95%.
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Tomás, Mir Magdalena. "Physiological mechanisms involved in water use efficiency in grapevines." Doctoral thesis, Universitat de les Illes Balears, 2012. http://hdl.handle.net/10803/84126.
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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
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Tonmukayakul, Nop. "Water use efficiency of six dryland pastures in Canterbury." Lincoln University, 2009. http://hdl.handle.net/10182/1498.
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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.
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Bernier, Marie-Hélène. "Assessing on-farm water use efficiency in southern Ontario." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=32251.
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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<br>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
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Wynn, Paul Laurence. "Water use efficiency and drought resistance in ornamental plants." Thesis, The University of Sydney, 2009. https://hdl.handle.net/2123/28220.
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Increasing concerns over the distribution, abundance and security of fresh water
resources in Australia have led to a nationwide re—evaluation of their management and
sustainability. The potential for reductions in municipal water use through demand
management are substantial, including the potential for savings through the improved
design and management of the irrigated urban landscape. It is proposed that the
selection of more appropriate plant species is essential to maximising outdoor water
savings. Current plant selection practices are, however, typically based upon highly
questionable and potentially flawed anecdotal evidence. Ideally, these decisions
should stem from detailed investigation of the water requirements, drought tolerance
and water use efficiency (WUE) of specific plants. Such investigation forms the basis
of this thesis. An extensive range of ornamental plant species were therefore
examined, chosen based on their origin (native vs. exotic) and aesthetic function or
utility in the landscape. It was hypothesised that those plants of Australian origin, due
to the frequency of drought in their native habitats, would demonstrate more tolerance
to water stress than their exotic counterparts. In the first of three experiments, plants
were subjected to varying levels of drought stress using differential rates of irrigation,
each replacing a fixed percentage of potential evapotranspirational demand. Plant
recovery capacity was subsequently assessed during an extended well—watered period.
A range of physiological parameters was monitored and, using digital image analysis,
changes in the level of foliar display and canopy transparency were assessed as
objective measures of plant ornamentality and amenity value. Development of an
improved method of imposing drought stress, for use in a subsequent study, involved
a separate detailed assessment of a high molecular weight polymer,
polydiallyldimethylammonium chloride (PDADMAC), which demonstrated its
significant potential as an osmoticum. A detailed and intensively monitored third
experiment was carried out with two groundcover species, the exotic Lobularia
maritima (Sweet Alyssum) and the Australian native Chrysocephalum apiculatum
(Yellow Buttons), each previously revealed as having particularly high WUE and
drought tolerance. Each species was subjected to one of several rates of drought
stress imposition using frequent incremental additions of PDADMAC to an air-lift
irrigation system followed by a period of recovery. A similar range of physiological
parameters was monitored in this study, in addition to carbon isotope discrimination
measurement and a microscopic examination of leaf surface morphology. There was
a high level of concurrence between the studies, with the plants of Australian origin
generally exhibiting superior drought resistance and higher WUE than the exotic
plants examined. The native plants typically maintained higher levels of foliar
display and exhibited higher net photosynthesis rates, transpiration rates and final
shoot dry weights than the corresponding exotics. The natives also maintained lower
overall leaf water potentials, both in the absence and presence of drought stress,
possibly enabling the positive water balance in plant tissues through the creation of a
strong water potential gradient between plant and soil. C. apiculatum appears to have
utilised other traits and strategies for its superior performance under drought stress,
including its contrasting phenology to L. maritima and its greater level of pubescence.
During recovery, the natives also demonstrated a greater overall capacity for
regeneration than the exotics, as measured by foliar gains. The effect of decreasing
water availability was also highly consistent across the studies, with decreasing water
availability producing overall declines in foliar display, foliar display—based WUE, net
photosynthesis rates, leaf water potentials, final shoot dry weights, survival times and
general plant health. Based upon the implications of these findings, a number of
practical recommendations were developed for use in the design and management of
water conserving urban landscapes.
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Manouseli, Despina. "Evaluation of residential water efficiency programmes in the UK." Thesis, Loughborough University, 2017. https://dspace.lboro.ac.uk/2134/25503.
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Water supply worldwide is facing pressure because of climate change and increasing water demand due to growing population and lifestyle changes. The traditional way of fulfilling the growing demand-supply gap by exploiting new fresh water resources and investing in the expansion of infrastructure is no longer considered environmentally or economically sustainable. The new path the water industry should follow is the management of water demand. Pilot residential efficiency initiatives are being launched by UK water providers over the past decade but despite the progress documented in this area, research on the evaluation of efficiency initiatives is still limited and little information is publicly available as to the magnitude of achieved water savings. Additionally, the need for establishing a robust evaluation framework is imperative. The present study uses double case study methodology to evaluate the effectiveness of two residential efficiency programmes in reducing water consumption in areas where two UK water companies operate. Utilising household water consumption, weather and demographic data, it defines the factors that affect per capita water consumption via regression analysis. Employing reference groups of households that did not participate in the programmes and means comparison tests, it investigates differences in consumption between participants and non-participants during the programme period. The study continues by using multilevel models to accurately measure the water savings achieved through each programme and to define the factors that affect a household s potential to save water. It further produces an evolved framework for savings evaluation, providing detailed guidelines to water companies that want to embark on the evaluation of their efficiency programmes, taking into account various data availability circumstances. Analysis illustrated a mean 6.95% decrease and a 14.7% decrease in consumption for each case study respectively, explicitly attributable to the efficiency programmes. Research findings provide strong evidence that single resident and financially stretched households have a bigger potential to conserve water and also highlight the robustness of multilevel analysis, even in cases of data limitations. This study provides invaluable guidance to water companies that aim to conduct water savings evaluation after an efficiency programme but also to the ones that are planning to embark into a new demand management initiative.
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Reyes, Torres Maria Del C. "Water Management Efficiency in the Food and Beverage Industry." ScholarWorks, 2016. https://scholarworks.waldenu.edu/dissertations/2298.
Full textAbstract:
Water is critical for food production, food security, and health. Water quality management influences freshwater sustainability, land, and energy administration. Global agriculture accounts for more than 70% of all water consumption; the fertilizer, manure, and pesticide overspills are chief sources of water pollution worldwide. On a global scale, food-related waste directly impacts local food production and water resource management. The purpose of this multiple-case study on the food and beverage (FB) industry in the State of Georgia was to identify successful strategies for improving water management efficiency. The concepts of systems thinking, adaptive resource management, and integrated water resource management provided the conceptual framework for the study. Data were collected via personal interviews with 2 global supply chain leaders in the FB industry and 1 water expert in the public water utility system in Georgia. The findings showed 10 themes: sustainability; mission-driven culture; ethical responsibility; water quality and governance; food safety and sanitation; water conservation and climatic trends; waste management; nutrition and the freeze drying method; knowledge sharing and collaboration; and water detention and retention systems. The study results are intended to contribute to social change by providing information to global supply chain leaders, policy makers, entrepreneurs, and sustainability leaders to implement sustainability beyond the environmental value; these findings will also help achieve a positive posture on resource overconsumption and waste management for efficient and complex decision making within a worldwide spectrum.
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Nickerson, Joel. "The Role of Knowledge and Attitude in Residential Irrigation Efficiency." Thesis, University of North Texas, 2012. https://digital.library.unt.edu/ark:/67531/metadc149645/.
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Residential irrigation efficiency is a long-term concern for any community that faces water supply stress. When ability to raise water prices is constrained, public education and conservation programs can produce reduced water usage. Understanding the factors behind residential irrigation efficiency allows the design of more effective conservation campaigns. Combining site-specific water budgets with usage data for four hundred homes in North Texas enables quantifying efficient irrigation behavior. A survey of homeowners tests for the presence of conservation-positive attitudes and the knowledge required to implement those attitudes. The influence of neighbors’ watering habits is investigated using spatial clustering tools. Findings are analyzed in the context of an attitude, knowledge, and habit model of conservation behavior. The presence of automatic irrigation systems, small irrigated areas, and having knowledge of the amount that one waters one’s lawn are found to contribute to more intensive irrigation. Mixed evidence for small-scale clustering in irrigation intensity is presented.
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Juana, James Sharka. "Efficiency and equity considerations in modeling inter-sectoral water demand in South Africa." Pretoria : [S.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-06062008-140425/.
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Newby, Adam F. "Increasing Water Application Efficiency in Greenhouse Crop Production UsingGravimetric Data." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1366376123.
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Hoolohan, Claire. "Reframing water efficiency : towards interventions that reconfigure the shared and collective aspects of everyday water use." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/reframing-water-efficiency-towards-interventions-that-reconfigure-the-shared-and-collective-aspects-of-everyday-water-use(9051041e-e89b-43e5-888a-f41ad9d4c926).html.
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This is a thesis about water efficiency, a particular set of practices in the water industry of England and Wales designed to reduce end-use water demand in homes and businesses. Broadly, the thesis aims to understand how water efficiency activities organised and funded by water companies might more effectively support the development of sustainable patterns of domestic demand, in order to contribute to long-term sustainable water management. To achieve this aim, mixed qualitative methods are used to; a) evaluate the extent to which two non-conventional water efficiency activities engage with the collective elements of everyday consumption that existing research deems necessary to steer demand (Strengers, 2012, Macrorie et al., 2014, Shove, 2014, Geels et al., 2015); b) develop a conceptual understanding of demand management as a professional practice, to understand how Water Company activities are shaped, sustained and stifled; and c) develop an understanding of what future water efficiency activities might look like that take account of the findings from this research. Central to this research and analysis is the notion of 'collective', a term that denotes a conceptual perspective on demand that departs from a focus on individuals, towards the shared social, technological and natural relations that structure everyday activity (Browne et al., 2014). The analysis uses this notion of collectives to examine the impacts and limitations of Save Water Swindon, a large-scale 'whole-town' approach to water efficiency (Case Study 1); to explore how Care for the Kennet contributes to demand management by reconfiguring relations between water in the home and water in the river (Case Study 2); and to uncover the collective context of the professional practices of managing demand (Case Study 3). The findings illustrate that demand is shaped by routines that extend far beyond the spaces in which water is used, both intentionally and unintentionally, and therefore highlight a distributed web of people and practices that might be involved in demand management. The findings from these empirical enquiries are used to as the basis to work with the water industry to reimagine interventions that engage in the collective context of demand, and elicit conceptual understandings of the processes and actors involved in governing social change. Overall, the approach taken in this thesis demonstrates the vitality of practice-based enquiry that provides deep analytical detail to better understand the mundane yet complex processes that sustain everyday water use. Supplementing the analysis with ideas from a variety of social science disciplines and working alongside the water industry, facilitated by the CASE studentship, pushes the analysis beyond the confines of domestic practices typical of practice-based research. Subsequently this research offers contributions to policy, practice and theoretical developments as it explores the intersections between demand and professional practices and local environments, evaluates interventions, examines practices of demand management, and unravels the possibilities for future intervention. Consequently, though focused on water management in the UK, this research offers insights for other resource agendas and regional contexts, expanding discussions in these spaces to think creatively about avenues for future policy and management practice.
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Bynum, Joshua Brian. "Physiological applications for determining water use efficiency among cotton genotypes." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2635.
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Choi, Seng Fai. "Bio-remediation of BTEX-contaminated water with enhanced removal efficiency." Thesis, University of Macau, 2006. http://umaclib3.umac.mo/record=b1636324.
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Malan, Cheryl. "The efficiency of drinking water treatment plants in removing immunotoxins." Thesis, University of the Western Cape, 2010. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_5762_1308732795.
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<p>The aim of this study was to evaluate the effectiveness of water treatment processes of two drinking water plants to remove immunotoxins and steroid hormones. Raw and treated drinking water was screened for effects on inflammatory activity using the biomarker IL-6, humoral immunity using the biomarker IL-10 and cell mediated immunity using the biomarker IFN-&gamma<br>. In vitro human whole blood culture assays were used in order to elucidate potential immunotoxicity.</p>
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Nageshkar, Vishal Vinayak. "Enhancing the splitting efficiency of water molecules using conductive nanomaterials." Thesis, Wichita State University, 2013. http://hdl.handle.net/10057/10640.
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Ogola, J. B. Ochanda. "Improving water use efficiency of maize through proper nitrogen management." Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340024.
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Fidar, Abdi Mohamud. "Environmental and economic implications of water efficiency measures in buildings." Thesis, University of Exeter, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.529289.
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Torba, I. "Optimization of ecological and economic efficiency of water resource reclaiming." Thesis, Sumy State University, 2017. http://essuir.sumdu.edu.ua/handle/123456789/65304.
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Reclaimed water or recycled water (wastewater reuse or water reclamation) is the process of converting wastewater into water that can be reused for other purposes. This process can include agricultural, landscape and field irrigation purposes or even replenishing surface water and groundwater, also referred to as groundwater recharge.
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Torba, I. "Optimization of ecological and economic efficiency of water resource reclaiming." Thesis, Sumy State University, 2017. http://essuir.sumdu.edu.ua/handle/123456789/66248.
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Reclaimed water or recycled water (wastewater reuse or water reclamation) is the process of converting wastewater into water that can be reused for other purposes. This process can include agricultural, landscape and field irrigation purposes or even replenishing surface water and groundwater, also referred to as groundwater recharge.
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Movahedi, Mahsa. "Identifying stomatal signalling genes to improve plant water use efficiency." Thesis, University of Sheffield, 2013. http://etheses.whiterose.ac.uk/4539/.
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Water is lost from higher plants via transpiration through stomatal pores the aperture of which is regulated by pairs of guard cells. Genetic engineering of the guard cell abscisic acid (ABA) signalling network that induces stomatal closure under drought stress is a key target for improving crop water use efficiency. In this study experiments were designed to investigate whether the biochemical mechanisms associated with the N-end rule pathway of targeted proteolysis could be involved in the regulation of stomatal apertures. The results indicate that the gene encoding the plant N-recognin, PRT6 (PROTEOLYSIS6), and the N-end rule pathway, are important in regulating stomatal ABA-responses in addition to their previously described roles in germination and hypoxia. Direct measurements of stomatal apertures showed that plants lacking PRT6 exhibit hypersensitive stomatal closure in response to ABA, and IR thermal imaging revealed reduced evapotranspiration under drought-stress. Together with a reduction in stomatal density, these properties result in drought tolerant plants. Plants lacking PRT6 are able to synthesis NO but their stomata do not close in response to NO suggesting that PRT6 is required for stomatal aperture responses to NO. Double mutant studies suggested that PRT6 (and by implication the N-end rule pathway) genetically interacts with known guard cell ABA signalling components OST1 and ABI1, and that it may act either downstream in the same signalling pathway or in an independent pathway. Several other enzymatic components of the plant N-end rule pathway were also shown to be involved in controlling stomatal ABA sensitivity including arginyl transferase and methionine amino peptidase activities. These results indicate that at least one of the N-end rule protein substrates which mediates ABA sensitivity has a methionine-cysteine motif at its N-terminus. A separate set of experiments were designed to investigate whether stomatal ABA-signalling pathways could have been conserved throughout land plant evolution. Cross-genetic complementation experiments were carried out to determine whether Physcomitrella stomatal apertures are able to respond to ABA and CO2 using a similar signalling pathway to that of flowering plants. The results demonstrated involvement of OST1 and ABI1 orthologues indicating that the stomata of the moss respond to ABA and CO2 using a signalling pathway that appears to be directly comparable to that of the model flowering plant Arabidopsis thaliana.
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Guerra, Elisa <1982>. "New water use efficiency strategies to cope with climate change." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5947/1/Guerra_Elisa_Tesi.pdf.
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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.
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Guerra, Elisa <1982>. "New water use efficiency strategies to cope with climate change." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5947/.
Full textAbstract:
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.
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GIOLITTI, Anna. "An empirical analysis of efficiency in the Italian water service." Doctoral thesis, Università degli studi di Bergamo, 2015. http://hdl.handle.net/10446/32142.
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The following empirical work examines the impact of a potential restructuring of the Italian water industry, considering a sample of 37 companies and 22 contiguous hypothetical mergers providing water in Italy from 2005 to 2009. With particular attention to the water industry cost efficiency is analyzed by using a parametric methodology: a Translog cost function has been estimated through the SURE model, in order to evaluate the behaviour of returns to scale. Small companies seem to benefit of economies of scale, while the biggest operators encounter diseconomies of scale. Focusing thus on a hypothetical consolidation of the sector, for a sample of 22 contiguous mergers, we apply the not-parametric Data Envelopment Analysis (DEA) in Bogetoft and Wang (2005), corrected for the bias through bootstrapping, to examine the potential efficiency gains from mergers. By decomposing the merger gains into a technical effect, a harmony effect and a scale effect, the results show – on average - high efficiency improvement potentials and relevant scale economies for small mergers. The lowest size to have diseconomies of scale is almost similar in the two applications (45930 users for DEA-VRS bias-corrected model, 37000 users for the Translog cost function estimate for 37 Italian water companies).
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Narayanan, Sruthi. "Canopy architecture and water productivity in sorghum." Thesis, Kansas State University, 2011. http://hdl.handle.net/2097/8760.
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Master of Science<br>Department of Agronomy<br>Robert M. Aiken<br>Increasing crop water use efficiency (WUE), the amount of biomass produced per unit water consumed, can enhance crop productivity and yield potential. The objective of the first study was to evaluate the factors affecting water productivity among eight sorghum (Sorghum bicolor (L.) Moench) genotypes, which differ in canopy architecture. Sorghum genotypes, grown under field conditions, showed significant differences in (a) biomass production, (b) water use, (c) intercepted radiation, (d) water productivity and (e) radiation use efficiency (RUE; the amount of biomass produced per unit of intercepted radiation which is suitable for photosynthesis). WUE and RUE were more strongly correlated to biomass production than to water use or intercepted radiation, respectively. RUE was positively correlated to WUE and tended to increase with internode length, the parameter used to characterize canopy architecture. These results demonstrate that increased utilization of radiation can increase water productivity in plants. Sorghum canopies that increase light transmission to mid−canopy leaves can increase RUE and also have the potential to increase crop productivity and WUE. The objective of the second study was to develop a quantitative model to predict leaf area index (LAI), a common quantification of canopy architecture, for sorghum from emergence to flag leaf stage. LAI was calculated from an algorithm developed to consider area of mature leaves (leaves with a ligule/collar), area of expanding leaves (leaves without a ligule/collar), total leaf area per plant and plant population. Slope of regression of modeled LAI on observed LAI varied for photoperiod sensitive (PPS) and insensitive (non−PPS) genotypes in 2010. A good correlation was found between the modeled and observed LAI with coefficient of determination (R[superscript]2) 0.96 in 2009 and 0.94 (non−PPS) and 0.88 (PPS) in 2010. These studies suggest that canopy architecture has prominent influence on water productivity of crops and quantification of canopy architecture through an LAI simulation model has potential in understanding RUE, WUE and crop productivity.
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Weber, Christopher. "Operational Efficiency in the Food and Beverage Industry Through Sustainable Water Consumption." ScholarWorks, 2019. https://scholarworks.waldenu.edu/dissertations/6813.
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The scarcity of water poses a threat to domestic and global economic sustainability while inhibiting the operational efficiency of food and beverage industry firms. The purpose of this multiple case study was to explore the strategies some food and beverage industry leaders in the United States used for implementing sustainable water consumption practices to improve operational efficiency. The conceptual framework for the study was stakeholder theory. The primary data source was semistructured interviews with 4 food and beverage industry leaders in Wisconsin who have responsibility for implementing their firms' sustainability practices, and the secondary data source was corporate sustainability reports. Thematic analysis was used to analyze data, which resulted in 4 themes: efficient equipment, stakeholder and sustainability focus, water recycling, and supply chain support. The implications of this study for social change include the potential for leaders in the food and beverage industry to use findings to create more sustainable water supplies and demonstrate greater stewardship of the environment.
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Pontoni, Federico. "Essays on water economics." Thesis, Paris 10, 2014. http://www.theses.fr/2014PA100053/document.
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La thèse est structurée autour de quatre articles. Le premier article - What determines efficiency? An analysis of the Italian water sector – offre une évaluation d’efficience du plus grand échantillon d’entreprises italiennes dans le secteur de l’eau qui ait jamais été rassemblé. Cela sur un horizon temporel de quatre ans. Le deuxième article – Hydropower rent in Northern Italy: economic and environmental concerns in the renewal procedure – a deux objectifs: le premier est d’estimer la rente de l’hydroélectricité en Italie, ce qui n’a jamais été intenté auparavant ; le seconde est d’analyser le trade-off entre l’appropriation de la rente et les améliorations environnementales. Le troisième article – Estimating a performance-based environmental fee for hydropower production: a choice experiment approach – développe une redevance basée sur la performance environnementale à mesure non seulement d’internaliser les coûts environnementaux que l’hydroélectricité détermine, mais aussi d'inciter les producteurs à aller au delà de la régulation environnementale existante : de cette façon, ils payent moins. Enfin, le quatrième article – Cheaper electricity or a better river? Estimating fluvial ecosystem value in Southern France – applique la méthodologie CE à l’étude du trade-off potentiel entre revenue-sharing et améliorations environnementales dans la Vallée d’Aspe (Pyrénées français), où plus de 100 MW de capacité hydroélectrique sont installés<br>The thesis is structured as a collection of four papers and it is ideally divided into two parts: the first one, composed of just one paper, is an efficiency analysis of the Italian integrated water sector; the second part, made of the other three papers, is thematic and studies hydropower production in terms of rent generation and environmental impacts.The first paper – What determines efficiency? An analysis of the Italian water sector – offers an original evaluation of the efficiency of the biggest sample ever gathered of Italian water companies over a period of four years.The first paper of the thematic part – Hydropower rent in Northern Italy: economic and environmental concerns in the renewal procedure – has two objectives: the first one is to estimate the hydropower rent in Italy, which has never been done before; the second one is to investigate the trade-off between rent seizing and environmental improvements.The second thematic paper – Estimating a performance-based environmental fee for hydropower production: a choice experiment approach – develops a performance-based environmental fee able not only to internalize the environmental costs that hydropower causes, but also to stimulate producers to outperform existing environmental regulation: the more they outperform, the less they pay.Finally, the third thematic paper – Cheaper electricity or a better river? Estimating fluvial ecosystem value in Southern France – applies the DCE approach to study the potential trade-off between revenue-sharing and environmental improvements in the Aspe valley, located in the French Pyrenees, where more than 100 MW of hydropower capacity are installed
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Liu, Rui. "Nanostructured Semiconductors for High Efficiency Artificial Photosynthesis." Thesis, Boston College, 2013. http://hdl.handle.net/2345/3160.
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Thesis advisor: Dunwei Wang<br>Photosynthesis converts solar energy and stores it in chemical forms. It is one of the most important processes in nature. Artificial photosynthesis, similar to nature, can provide us reaction products that can potentially be used as fuel. This process promises a solution to challenges caused by the intermitted nature of solar energy. Theoretical studies show that photosynthesis can be efficient and inexpensive. To achieve this goal, we need materials with suitable properties of light absorption charge separation, chemical stability, and compatibility with catalysts. For large-scale purpose, the materials should also be made of earth abundant elements. However, no material has been found to meet all requirements. As a result, existing photosynthesis is either too inefficient or too costly, creating a critical challenge in solar energy research. In this dissertation, we use inorganic semiconductors as model systems to present our strategies to combat this challenge through novel material designs of material morphologies, synthesis and chemical reaction pathways. Guided by an insight that a collection of disired properties may be obtained by combining multiple material components (such as nanostructured semiconductor, effective catalysts, designed chemical reactions) through heterojunctions, we have produced some advanced systems aimed at solving fundamental challenges common in inorganic semiconductors. Most of the results will be presented within this dissertation of highly specific reaction routes for carbon dioxide photofixation as well as solar water splitting<br>Thesis (PhD) — Boston College, 2013<br>Submitted to: Boston College. Graduate School of Arts and Sciences<br>Discipline: Chemistry
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Ali, Qurban. "Development of novel multifunctional nanocomposites for antimicrobial efficiency in water treatment." Thesis, University of Central Lancashire, 2018. http://clok.uclan.ac.uk/25416/.
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Water pollution is a major concern worldwide. Bacteria, viruses and fungi present in drinking water cause various diseases as a result of poor hygienic conditions in developing countries. Similarly, presence of microorganisms in drinking water is a threat to public health in developing world due to poor hygienic condition. Numerous disinfectants and biocides are used for inhibiting the growth of pathogenic microbial contamination, producing carcinogenic by-products which are dangerous to human health. This work involved the synthesis, characterisation and application of novel multifunctional nanocomposites by the modification of cost effective available materials for antimicrobial treatment of contaminated water and the detection of specific DNA associated with water-borne bacteria. A series of multifunctional nanocomposites composed of commercially available carbon (activated charcoal and multi-walled carbon nanotubes), and silica-based materials such as diatomeous earth, celatom-80 and celatom-14 were modified with silver and iron oxide nanoparticles via a simple one-pot synthesis protocol in order to incorporate antimicrobial and superparamagnetic properties. The resultant materials have been tested for antimicrobial efficiency using model water system containing Gram-negative Escherichia coli (E. coli) K12 and Gram-positive Staphylococcus. aureus (S. aureus) microorganisms. It was found that all materials ranging from 10 to 200 μg/mL produced excellent inhibition of S. aureus and E. coli. All nanocomposites have been fully characterised by several physico-chemical techniques such as Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), X-ray Fluorescence (XRF), Energy Dispersive X-ray Analysis (EDAX), Fourier Transform Infrared Spectroscopy (FT-IR), Nitrogen gas adsorption and (BET) surface area analysis. Surface area of the materials measured in range of 5 to 560 m2/gm. XRF along with EDAX/SEM analyses have been used for the confirmation of silver and iron oxide presence in the nanocomposite materials. TEM images showed nano-sized silver particles with an average diameter of 15-17 nm and iron oxide (magnetite) nanoparticles with an average diameter of 30 nm embedded into the nanocomposites. FT-IR spectroscopy measurement confirmed the presence of Fe-O bonding of iron oxide nanoparticles due to a characteristic stretching vibration at 570 cm-1. Powder X-ray Diffraction (XRD) measurements confirmed the crystalline structure of the iron oxide nanocomposite mostly magnetite (Fe3O4). Nitrogen gas adsorption-desorption experiments suggests the presence of average pore diameter 28 to 79 Å, micropore volume: 0.01 to 0.16 cm³/g, and surface area 5 to 560 m2/g. Gram-negative E. coli K12 and Gram-positive S. aureus bacteria were used for anti-bacterial activity study where the nutrient agar was used for the growth of the bacteria. The antimicrobial effect of the nanocomposites was quantified by counting the number of colonies (colony forming unit, CFU/mL) grown on the media compared with a blank solution. Different concentrations (0.2 µg/mL to 300 µg/mL) of the nanocomposite materials were used for this study. MBC of QM1-3 and QM2-3 was found 10 µg/mL for the S. aureus and 30 µg/mL for E. coli K12, while other samples of QM3-3, QM4-3 and QM5-3 were higher such as 30 µg/mL for the S. aureus and 100 to 200 µg/mL for E. coli. All experiments were performed in triplicate and the data presented are the mean values of triplicate experiments ± standard deviation. Detection of water-borne microorganisms is the second application of the developed nanocomposites via surface modification with specific oligonucleotides sequences of E. coli gene followed by hybrid capture with complementary sequence. It was observed that multi-walled carbon nanotubes, activated charcoal and diatomeous earth gave good and satisfactory results (0.384 to 0.400 nmol/mg) in hybrid capture of complementary oligonucleotides sequences in model assay. Surface modified optimum materials (carbon nanotubes and activated carbon) with efficient hybrid capture were also efficient in detecting amplicon of 97 base pairs (bp) of E. coli specific genome by PCR experiment.
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Cooley, Amanda. "Estimating the Water Budget of Extratropical Cyclones with the Precipitation Efficiency." Thesis, University of Missouri - Columbia, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=13850734.
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<p> Estimating the water budget of three mid-latitude extratropical cyclones is attempted from the perspective of the precipitation efficiency (PE), using a method proposed for the study of convective columns. Using a lagrangian, system-relative volume centered on the surface low pressure, each cyclone was followed for most of its lifetime within a pre-defined volume (7 degrees latitude x 9 degrees longitude, or approximately 700 x 700 km). A comparison is then made of total atmospheric water vapor ingested to total moisture eliminated (as precipitation). We hypothesize that the PE increases with the intensity of the cyclone. This small sample confirms that idea, and thus encourages further study with this approach.</p><p>
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Wunder, Clemens. "Improving Stability and Efficiency of Earth-abundant Electrocatalysts for Water Oxidation." Thesis, Umeå universitet, Kemiska institutionen, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-173087.
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Hamdani, Anber. "The genetic and physiological basis of water use efficiency in tomatoes." Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/18642.
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Drought and heat stress are the major abiotic constraints to plant survival and productivity. This study focused on the estimation of genetic variability in response to water deficit conditions, evaluated the use of carbon isotopes to measure water use efficiency (WUE), and identified SNP marker associations with traits linked to higher genotypic performance under water deficit stress. The diverse plant materials were subjected to two irrigation regimes in two planting seasons and characterized for various morphological and fruit quality traits to explain the genetic variance. The study suggests fruit length to diameter ratio, number of fruits and fruit setting should be considered for selection under water deficit environments. The accessions were genotyped using SNPs to identify marker trait associations (MTAs) under water deficit conditions. About 20% markers were found to be significantly associated with the various traits. Being growth condition specific, these MTAs will need to be validated in a wider set of materials and environments. A subset including six genotypes was used to investigate WUE under controlled conditions at Purdue University, West Lafayette. The WUE was assessed using gravimetric measurements, leaf isotopic composition and diurnal gas exchange measurements. Strong association among ∆13C and other traits including assimilated weighted average intracellular CO2 concentration, intrinsic and instantaneous WUE under varied water deficit levels was observed. The results demonstrated the efficacy of carbon isotopes in predicting changes in WUE as well as substantial variation in WUE among Solanum lycopersicum accessions. The information generated from the present study will advance knowledge to understand the genetic, physiological, and fruit quality response under water deficit stress conditions and help tomato industry develop better adapted tomato genotypes.
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Liang, Tong Geng. "Trading and economic efficiency in selected Victorian water markets in Australia." Thesis, Liang, Tong Geng (2013) Trading and economic efficiency in selected Victorian water markets in Australia. PhD thesis, Murdoch University, 2013. https://researchrepository.murdoch.edu.au/id/eprint/21316/.
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Optimal allocation of irrigation water is a modern economic and social concern of growing importance in Australia, as well as in many other countries. The market based mechanism has been advocated in the economics literature as an efficient and effective measure for allocation of irrigation water. Water markets and water rights trading have been operating for many years aiming to improve the efficiency of water allocation in the Murray–Darling Basin (MDB) in Australia. Several stages of the Council of Australian Government's water reform agenda have been implemented. Water right and land ownership have been separated so that allocations or entitlements of water rights become transferable. Farmers can therefore trade their water rights in water markets without having to transfer their land ownership.
Few empirical studies have been conducted into the efficiency and effectiveness of water markets. This study examines economic efficiency, competitiveness, and irrigators’ response to the changes of economic and non economic variables in allocation water markets in Victoria that permit trading in irrigation water rights.
This study begins with an analysis of the economic theory of efficient allocation of water, the theory of goods underlying water markets, the public and private nature of these markets, along with attention of externalities, market structures and the role of natural monopolies in water industry. It provides an examination of the systems of water rights found in the literature, a discussion of the legislative basis of the water right systems that govern access to and use of irrigation water in each of Australian states and territories including the institutional arrangements shaping trade in Victorian water markets. The legislative water right in Australia is the contemporary water allocation system and governs water entitlements and allocations. Water rights are essentially a bundle of entitlements that define the rights, privileges and limitations for the use of the water of an owner. The characteristics of water rights include universality, exclusivity, transferability and enforceability. In Victoria, under the Water (Resource Management) Act 2005, new regulations were issued, and a number of major changes to the water trading landscape were made, including the creation of an environmental water reserve; the unbundling of existing water entitlements into water shares, and the creation of the Victorian water register. On a national level, the key water policies are specified in the National Water Initiative in 2004. The Water Act 2007 (Commonwealth) secures the water supply and water allocation equitably including the allocation for the riverine environment in MDB.
The demand and supply for irrigated water, the markets for water rights trading and the contestability of Australian water markets is analysed. Also, the existing water market mechanisms and trading including the evolution of the markets, their structure, and the trading rules and institutional arrangements in the Murray–Darling Basin region in Australia is described. The Murray–Darling Basin region is the most active region of irrigation water trading in Australia. The relevance of the determinants of demand and supply for irrigation water and the price elasticity of demand are discussed. The auction form of water trading in the water market is also described, and the Watermove water market in Victoria is analysed.
Empirical evidence on the economic efficiency of three water markets in northern Victoria is provided. The stochastic time series properties of water prices are established through statistical tests commonly used to evaluate market efficiency in financial and commodity markets. The random walks of the stochastic properties of water price time series for the three markets are tested. The results of Augmented Dickey–Fuller’s unit test, Zivot and Andrews unit root test with one structural break, and Lee-Strazicich LM unit root test with one structural break and two structural breaks suggest that the water price time series in the three markets that the water price time series are non stationary and follow random walks. The findings are very important, and prove that the three markets are efficient according to the theory of Efficient Market Hypothesis since the water prices cannot be predicted based on the available market information for traders.
More conventional scrutiny of industry efficiency is achieved through measures of the size distribution of firms. The measures which include concentration ratio, Herfindahl– Hirschman index, and Gini coefficient, are applied to analyse the three markets’ concentration and competitiveness in terms of the market size, the number of traders who participated, the number of successful traders, and the quantity of water traded. These measures for the three water markets have consistent results. The outcomes of the three measures in the market structure, and the competitiveness for the three markets suggest that there are no monopolies and oligopolies in supply, and there are no monopsonies and oligopsonies in demand in the three water markets. Also, the outcomes of the analyses suggest that there are many irrigators participating in the three water markets, either as sellers or buyers, and they are price takers. However, one market is a relatively moderate concentrated market and a monopolistic competitive. The results suggest that the three water markets are between perfect competition and monopolistic competition.
Finally, models of water demand for the three water markets are developed and estimated with a view to measuring the strength of price and non-price factors driving changes in the demand for irrigation water. The estimated OLS models of demand for water for the three water markets in this study suggests that the macro economic variables in relation to agriculture including the rural commodity index, the rural GDP and the rural export in Australia do not have influence on the demand for water in the three water markets. The estimated water demand models for the three water markets show that the evaporation has positive impact on the demand for water, and the water price and the rainfall have negative impact on the demand for water. The findings are consistent with the economic logic. The findings suggest that the direct explanatory variables, the water price, the rainfall and the evaporation, influence the demand for water in the three water markets, but they are water demand inelastic.
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Aurigi, Daniele. "How regulation affects efficiency and investments in the water sector: a theoretical approach and a case study of the Italian water integrated system in Tuscany." Doctoral thesis, Università di Siena, 2020. http://hdl.handle.net/11365/1121478.
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My thesis analysed some aspects of water sector regulation. It has two theoretical chapters and a case study.
In the first chapter, I used a simple model in order to describe the effect of tariffs regulation on the efficiency of the water providers and to give one possible justification to revising the tariffs method so often as Arera has been doing. In the last part of the chapter, I analyse theoretically another segment of the tariff methods: the incentive to improve efficiency. I found out that the type of incentive in the Italian tariff methods works only for the firms that have the operative costs near the average.
In the second chapter, with a variation of the basic model, I analysed the effect of a two-level system of regulation (one National Authority and several Local Authorities) on the investments made by water providers. I introduced in the model the Local Authorities staff's skill and expertise. Smith (2000) described the advantages and the disadvantages of centralised and decentralised systems of regulation and Danesi at al. (2008) applied that analysis to the Italian case suggesting that a two-level system could have the benefits from both types of regulation. I try to add new elements that provide other possible justification for a system with a national Authority and several sub-national Authorities.
In the third chapter, I used the Tuscan Water system as a case study. I explore the Tuscan data to see the actual results of the regulation, in an environment with relatively good local regulator, on a set of providers with mixed ownership where the public administration have the majority. I inferred that providers' mixed property seems to be a good structure to balance achieving efficiency and increasing investments with tariffs control, confirming and expanding Macchiati et al. (2019)
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Knamiller, C. "The impact of domestic water user cultures on water efficiency interventions in the South East of England : lessons for water demand management." Thesis, University of Bradford, 2011. http://hdl.handle.net/10454/5329.
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The need for a more sustainable approach to water consumption has increasingly gained attention in the last decade. The domestic sector accounts for over half of abstracted water in the UK and, as such, has become a major target for water efficiency interventions. Current research and water efficiency interventions are dominated by a positivist approach, focusing on a limited range of factors that can be quantitatively measured. This thesis questions the dominant approach and argues that a more holistic overview of water efficiency can be achieved through the consideration of socio-technical and behavioural theories. Taking a more constructivist approach, this research draws on four theories from socio-technical and behavioural fields and combines them to create a framework for the analysis of water efficiency interventions. The framework is applied to two case studies, exploring water users' perceptions of water, water supply, personal water use, and their responses to the water efficiency interventions. The case studies were selected to provide examples of current mainstream approaches to water demand management. Research methods used included semi-structured interviews and observation. The research findings support the argument that the current dominant approach to domestic water efficiency interventions is limited and, in some cases, ineffectual. Issues of trust, knowledge, motivation and the relationships between water users and water companies were raised. The thesis concludes that the use of a constructivist perspective could help to provide a more effective approach to understanding and improving water demand management.
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Pointeau, Virginie M. "Water-use efficiency and productivity in native Canadian populations of Populus trichocarpa and Populus balsamifera." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/587.
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Afforestation and reforestation programs utilizing available fields for biofuel production, carbon sequestration, and other uses linked to climate change are looking to tree physiologists to identify species and genotypes best-suited to their purposes. The ideal poplar genotype for use in Canadian programs would be drought-resistant, cold-climate adapted, and fast-growing, thus requiring an understanding of links between a variety of physiological traits linked to growth and productivity. This study examined the basis for variations in water-use efficiency within four selected populations of Populus trichocarpa and Populus balsamifera (2 provenances each). Each species included both a northern and a southern provenance. Correlations between water-use efficiency, nitrogen-use efficiency, ¹³C/¹²C isotope ratio, stomatal conductance, and overall productivity were evaluated. Gas exchange variables measured included net photosynthesis, transpiration rate, stomatal conductance, and intercellular CO₂ content. Water-use efficiency and ¹³C content across all genotypes were highly correlated. Results suggested that variation in water-use efficiency was primarily related to variation in stomatal conductance across all genotypes. Whereas differences in net photosynthesis in this study were not significant between species, P. balsamifera did reveal a higher average stem volume overall. Although variation in stomatal conductance was the major determinant of differences in water-use efficiency, positive correlations were found between ¹³C isotope abundance and net photosynthesis in both P. balsamifera provenances. In this regard, results for the northern P. balsamifera provenance are the most consistent across all gas-exchange and growth trait correlations, in terms of meeting expectations for sink-driven water-use efficiency. The findings in this study suggest the possibility of identifying poplar genotypes with an absence of trade-off between water-use efficiency and nitrogen-use efficiency, notably among genotypes from the northern P. balsamifera provenance, near Gillam.
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Huang, Po-Sheng, and 黃柏升. "Study on efficiency of water electrolysis." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/3qp3n4.
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碩士<br>國立中央大學<br>機械工程研究所<br>96<br>During the process of releasing energy, hydrogen produce no green-house-effect gas and has a potential as a energy carrier in the future. Among the methods of hydrogen production, water electrolysis has many advantages, such as high efficiency, high purity in producing hydrogen, easy in use, etc., and thus become one of popular methods.
In this study, we use platinum electrodes and modified experimental set-up to study the effects of working parameters, such as concentration of electrolyte, current, voltage, and the time on the efficiency of electrolysis. Based on the data recorded by AUTOLAB power supply and the energy consumed through electrolysis, we can find out the optimum parameters for water electrolysis to improve the hydrogen production efficiency of water electrolysis.
The results of experiment show that temperature greatly affects the electrolysis efficiency. Each increase of 25℃ gives electrolysis efficiency raising about 5% to 6% from 27℃ to 75℃. Before experiment, I predict that electrocatalytic of Pt and ion transfer of electrolyte would differ from temperature. It’s also found that the relation between temperatures with better concentrations for better electrolysis efficiency is so week and in most conditions the better concentration of KOH is 30%.
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Rasiuba, Thabo Cecil. "Water budget, water use efficiency in agriculture in Olifants catchment." Thesis, 2009. http://hdl.handle.net/10539/5974.
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Eighty percent of the agricultural land worldwide is under rain-fed agriculture that
takes place on most soils that are generally low in fertility with attendant high on
farm water losses, thereby resulting in low crop yields. This is particularly
significant in sub-Saharan African states where a higher percentage of the
population is involved in agriculture and the economy is predominantly driven by
rural-based rain-fed agriculture. In the Olifants catchment, the challenges in rainfed
agriculture are compounded by erratic, highly variable rainfall patterns in
space and time.
The study area (Sekororo, B72A quaternary catchment) is within lower Olifants
region. It is located between latitude 24000’00” and 24025’00” South and between
longitude 30015’00” and 30045’00” East. The survey sites within the B72A
quaternary catchment are Worcester, Enable, Ha-Fanie, and Sofaya. The results
on soil nutrients indicate that the soil fertility is very poor, indicative of poor land
management which also impacts adversely on water use and crop yields.
The data from Statistics South Africa indicate that average number of people per
household dwelling at B72A quaternary catchment is five. Taking into account
maize consumption of 100kg per person per annum and average number of
persons per household, maize required to achieve food security would be 500kg
per household per annum and at current average crop yield of 300kg/ha, food
insecurity is very high for rain-fed farmers.
The data on rainfall partitioning indicate that at least 38% of the received rainfall
is lost to run-off. The modeled results indicate that crop yield can be improved to
800kg/ha if significant portion of rainfall lost to run-off is harvested, thereby
eliminating food insecurity for rain-fed farmers.
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Matulka, Matthew Neil. "Water use, yield, and water use efficiency of differentially irrigated alfalfa." 1985. http://hdl.handle.net/2097/27495.
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Chen, You-Ruei, and 陳宥瑞. "Gas water heater Efficiency Improvement and Design." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/08003735722868003472.
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碩士<br>朝陽科技大學<br>精密機械暨水下機電技術整合產業碩士專班<br>104<br>Abstract
In today's gas water heaters have become general household essential goods. Gas water heater as the name implies, is a combustible gas and air are mixed in the way, after entering the burner gas mixing in the combustion chamber for combustion heaters, heat conversion achieved. In the case of today's emphasis on economic, security and environmental protection, in order to achieve better performance, lower cost, safety and reduce pollution, the development trend of today.
This study will focus on a particular core heating gas water heater, burner and combustion chamber design incomplete combustion caused by poor design improvement process will be assisted by scientific simulation software to explore and improve gas water heater caused by bad design incomplete combustion problems.
Keywords: Gas water heaters, Gas mixed with air, Fluid mechanics