Дисертації з теми "Alternatives ranges"

Le secteur minier occupe une place centrale dans les économies de nombreux pays riches en ressources minérales, d’autant plus dans une période d’explosion démographique. Les conséquences économiques, sociétales et environnementales des activités extractives posent plusieurs problèmes majeurs, liés à l’incertitude géologique, la volatilité des prix, les déchets polluants, l’épuisement futur des gisements, la situation socioéconomique et la santé des populations locales. Ainsi, l’exploitation du phosphate, élément vital dans la croissance des plantes, fait face à d’importants défis incitant les entreprises minières à mieux maîtriser leur processus industriel sur l’ensemble de leur chaîne logistique. Les travaux de recherche présentés dans cette thèse entrent dans le cadre d’une recherche intervention conduite au sein d’une chaîne de valeur du Groupe OCP, leader mondial des phosphates. L’objectif est double : 1) proposer des outils et méthodes innovants pour l’amélioration du processus décisionnel opérationnel et tactique ; 2) accompagner l’entreprise dans l’adoption des approches proposées. La chaîne logistique étudiée, l’Axe Nord, se compose de plusieurs sites miniers, d’unités de traitement, d’usines chimiques et de ports pour l’expédition des produits. Un premier travail d’état des lieux au sein de cette chaîne a conduit à mieux comprendre son organisation et à identifier les principales causes impactant la qualité des produits : le pilotage par un seul composant et l’alimentation continue en produit interne. Pour étudier la problématique de blending identifiée, l’intervention proposée consiste en une approche développée en deux temps. Tout d’abord, la formulation classique du problème de blending été fortement adaptée dans un modèle tenant compte de l’aspect continu des flux transportés par pipeline, de gammes alternatives, de l’organisation des usines de traitement, mais aussi de temps de traitement. Ce modèle, dit de « blending dynamique », se base dans un premier temps, sur un ordonnancement déjà établi de l’expédition des produits par pipeline (donnée exogène) pour trouver un plan de production des usines de traitement. Dans un second temps, un modèle d’ordonnancement de ces expéditions est couplé au précédent modèle dans une vision d’aide à la décision. Les premiers tests avec des instances réelles ont fourni des résultats prometteurs, l’approche du blending dynamique étant actuellement opérationnelle sur d’autres sites miniers de l’industriel
The mining sector occupies a central place in the economies of many mineral resource-rich countries, even more so in a period of demographic explosion. The economic, societal and environmental consequences of extractive activities raise several major problems, related to geological uncertainty, price volatility, polluting waste, future depletion of deposits, the socioeconomic situation and the health of local populations. Thus, the exploitation of phosphate, a vital element in plant growth, is facing important challenges that encourage mining companies to better control their industrial process throughout their supply chain. The research work presented in this thesis is part of an intervention-research conducted within a value chain of the OCP Group, world leader in phosphates. The objective is twofold: 1) to propose innovative tools and methods for the improvement of the operational and tactical decision-making process; 2) to accompany the company in the adoption of the proposed approaches. The logistic chain studied, the Northern Axis, is composed of several mining sites, processing units, chemical plants and ports for product shipment. An initial inventory of this chain led to a better understanding of its organization and to identify the main causes impacting the quality of the products: the steering by a single component and the continuous supply of internal product. To study the blending problem identified, the proposed intervention consists of an approach developed in two stages. First, the classical formulation of the blending problem was strongly adapted in a model taking into account the continuous aspect of the flows transported by pipeline, alternative ranges, the organization of the processing plants, but also the processing time. This model, called "dynamic blending", is based in a first step, on an already established scheduling of the shipment of products by pipeline (exogenous data) to find a production plan of the processing plants. In a second step, a scheduling model of these shipments is coupled to the previous model in a decision support vision. The first tests with real instances provided promising results, the dynamic blending approach being currently operational on other mining sites of the industrialist

NFC is a technology that allows close-range communication between mobile devices. Unfortunately, not all modern smartphones have the required API’s or hardware to utilize it. This thesis seeks therefore to develop a viable alternative to NFC for close range communication (less than 10 cm) between mobile smart phones. The goal is to evaluate the feasibility of using a novel scheme that utilizes near ultrasonic frequencies for close range communication for both Android and iOS.An iPhone and an Android device were used to test our proposed scheme. Range test were preformed on a quiet and noisy environment (food court in a shopping mall), and an interference test was done in the quiet environment. The scheme was shown to work in the tested quiet and noisy environment for ranges less than 1 cm. In the noisy environment, significant data loss happened at 5 cm for the tested android device, while data was somewhat reliably received at up to 10 cm in a quiet environment among both tested devices. Our tests also show that concurrently communicating devices spaced at least 110 cm away will not interfere with each other.Our findings show that the proposed scheme could be a viable alternative for close range communication. By employing an error correcting code, tolerance to data loss could be improved. Using a different modulation technique is also advisable in order to improve the data transfer rate.For future work, we suggest testing the near ultrasonic capabilities of a wider array of devices in order to determine the usefulness of the proposed scheme.
NFC är en teknologi som tillåter kommunikation på korta avstånd mellan mobila enheter. Dessvärre finns det enheter som saknar hårdvarustöd för NFC samt att vissa enheter inte har denna funktionalitet tillgänglig för apputvecklare. Denna uppsats försöker därför att utveckla ett gångbart alternativ till NFC som möjliggör kommunikation på korta avstånd mellan mobila enheter. Målet med uppsatsen är att undersöka utförbarheten av utvecklandet av ett schema som använder frekvenser som ligger nära ultraljudsspektrumet för att tillhandahålla kommunikation på korta avstånd för både Android och iOS.En Android och en iPhone enhet användes för att testa schemat. Ett avståndstest utfördes i både en tyst och en bullrig miljö (restaurangtorg i en köpcenter), samt ett inteferenstest som gjordes i en tyst miljö. Vårt utvecklade schema har påvisats fungera i både den tysta och bullriga miljö vi testade i, på avstånd kortare än 1 cm. I den bullriga miljön försämrades överföringsmöjligheterna avsevärt på ett avstånd av 5 cm för den Android enhet vi testade på, medan avstånd på upp till 10 cm var gångbara i den tysta miljön vi testade i. Våra test visade även på att enheter positionerade minst 110 cm bort ifrån varandra kan kommunicera samtidigt utan att störa varandra.Våra resultat visar på att vårt schema skulle kunna fungera för kommunikation på korta avstånd. Användandet av felkorrigerande koder skulle kunna förbättra schemats tolerans mot dataförluster. Användandet av en alternativ moduleringsteknik är också att föreslå för att förbättra överföringshastigheten.För framtida arbeten anser vi att förmågan att producera frekvenser som ligger nära ultraljudsspektrumet bör undersökas hos en större mängd mobila enheter, för att fastställa användbarheten av det föreslagna schemat.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture, 2003.
Includes bibliographical references (leaves 31-33).
How does land differentiate itself from other land by the way that it is marked? What implicit power relations are evidenced in these land marking processes? Whose interests are served in the designation of certain places for preservation and others not? What are the strategies for reclaiming marked land? What are the stakes? How does one articulate an ethics of land use? Who decides what is worth preserving and what is worth destroying? Landmark is a working concept as well as an artistic proposition which considers the multiple and complex ways in which land is marked. Focusing on the contested United States Navy Training Facilities in Vieques, Puerto Rico, Landmark: Towards an Alternative Testing Range attempts to create a platform for cross-border exchanges, between local reclamation struggles and global resistance movements. By focusing on the area of greatest destruction, the inner range, as a metaphoric as well as physical ground from which to begin and engage in dialogue, Landmark, considers the possibility of sharing wounds across space and time, through the creation of a transitional geography, one between destruction and recovery.
by Jennifer Allora.
S.M.

This project aims to increase the tools available to new technological developments, by exploring the benefits of an alternative triangulation-based rangefinder design. This is accomplished by replacing resolution restrictive components of existing triangulation systems, such as CCD sensors, with analogue or high resolution components. Higher resolution, higher speed components are hoped to increase accuracy and allow further detectable ranges. A working prototype was designed and constructed from simple, cheap parts. Results show the prototype matches the detectable ranges of most existing triangulation- based range finders, and retains the ability to be configured to focus on specific detection ranges. The constructed device has many known opportunities to be upgraded. By replacing components with well-developed “off the shelf” technology, it remains possible that the proposed design could exceed the benefits of existing triangulation-based range finders.

The only available broiler strain to use in organic chicken meat production, until recently, has been conventional fast growing broiler hybrids. The Rowan Ranger is a broiler strain that has a naturally slower growth rate which makes this strain suitable for organic farming, meeting the demands of KRAV without being subjected to a feed restriction. One of the farms in Sweden using Rowan Ranger in their organic production is Bosarp farm in Skåne County where they produce KRAV certified chickens and where the animals used in this study were raised. This study compared differences between a naturally slow growing strain of chicken to a fast growing strain to see whether there were differences in behaviour between the two, if one of the strains was more susceptive to stress than the other and whether they differed in outdoor use and activity level. Regardless of strain, chickens used the outdoor perimeter the same, although the Rowan Rangers did not range as far from the chicken house as Ross 308. Even so, they seem to be more suitable in an organic setting than Ross 308 due to the fact that they seem less hungry and more content, this based on the fact that they perform less feeding behaviour and spend more time laying down. Also, they grow nicely to slaughter weight with a good diet quality whereas Ross 308 need to be qualitative feed restricted to do the same, giving the Rowan Rangers better welfare.

Fleas are one of the major external parasites affecting free range chickens, causing irritation, tissue damage, blood loss and toxicosis which in turn affect quality and quantity of meat and egg production. There are many commercial insecticides available that are effective against fleas. These commercial insecticides have, however become expensive to most resourcelimited farmers and therefore unaffordable, causing farmers to seek low cost alternatives. This study was conducted to document, determine the existence of external parasites in freerange chickens and validate the alternative remedies used in controlling free-range chicken fleas by resource-limited farmers. A questionnaire survey was used to collect data on external parasites of free-range chickens and ethno-veterinary control remedies used by resourcelimited farmers to control these parasites at Amatola basin, in Eastern Cape, South Africa. Resource-limited farmers perceived that mites (79.6%), fleas (64.5%), lice (10.8%) and ticks (6.5%) were problematic parasites of chickens. To control these parasites, resource-limited farmers commonly use ash (28%) madubula (13% carbolic acid) (26.7%), Jeyes fluid (13% carbolic acid) (10%), paraffin (8.4%), used engine oil (2.8%), plants Tagetes minuta, Clutia pulchella, Calpurnia aurea (5.2%) and a few (4.2%) used commercial drugs Karbadust (Carbarly 5%) and mercaptothion 5%. About 7.5% of the respondents used neither of the remedies. To confirm the farmers’ perception on problematic external parasites of free-range chickens a diagnostic survey was conducted. Fifty free-range chickens were randomly selected and examined for external parasites. About 96% of the free-range chickens examined harboured at least one species of external parasites. Fleas (Echidnophaga gallinacea) (50.7%) were the most prevalent followed by lice, Menopon gallinae (12.4%); Menacanthus stramineus (5.3%) and Knemidocoptes mutans (0.57%). Given that Jeyes fluid, used engine oil, paraffin, C. aurea, C. pulchella and T. minuta were mainly used in controlling these parasites, it was important to determine the potential dermal irritant effects of these plants. A dermal irritant effect test was, therefore, conducted using a rat model. Forty eight rats, with parts of the backs shaven, were used to screen the materials for irritation. All the materials tested did not cause any visible skin irritation on rats (p>0.05). Regarding that ethnoveterinary materials were non irritant on rat skin in vitro repellency and contact bio-assay models were used to assess the insecticidal properties of Tagetes minuta, Calpurnia aurea, Clutia pulchella, used engine oil, paraffin and Jeyes fluid on fleas. For the in vitro bioassay T. minuta and Jeyes fluid at 100% concentration demonstrated a repellency level of 76 and 83%, respectively. Tagetes minuta was the most effective among plant materials (p<0.05). Clutia pulchella, C. aurea, used engine oil and paraffin showed insignificant repellency (p>0.05). For the contact bio-assay, C. pulchella, C. aurea and T. minuta at a concentration of 100% resulted in flea mortality of 83.5, 73.3 and 42.5%, respectively. The efficacy of Clutia pulchella compared well with that of Karbadust which had a mean mortality of 97.5%. Paraffin, used engine oil, and Jeyes fluid (19.2%) caused higher flea mortality of more than 82%. In the in vivo study 60 free-range chickens were artificially infested with fleas and test materials were topically applied on infested sites. Test materials exhibited varying flea load reduction efficacy. Used engine oil and Jeyes fluid at 76.8% concentration had a reduction efficacy of 100 and 96% after 3 days post application of test materials. These were not significantly different to that of the positive control Kabadust (carbaryl 5%). The plants C. pulchella and C aurea at 100% concentration had an efficacy of 92 and 77%, respectively. The commonly used remedies by resource-limited farmers to control fleas vary in efficacy. Some of the materials are as effective as the commercial insecticides hence they have a potential to be exploited as insecticides. Further investigations on plant compounds with insecticidal properties and their toxicity, need to be conducted before the plants are recommended for use.

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Salmonella sp. might cause food deseases in humans and it be isolated from the gastrointestinal tract of different animal species, especially birds. In this study, we aimed to point out the main characteristics of non-conventional poultry farm systems at Central and South regions of the State of Goiás and to determine the frequency of Salmonella sp. Isolation in conventional and non-conventional poultry farms, as well as the frequency of positivity for antigen-antibody reaction at non-conventional poultry farms. On paper 1, we studied 190 non-conventional systems of broiler rearing; we collected 3,040 blood and organ samples (heart, liver, crop and cecum) from 760 birds. Rapid Plate Agglutination Test was used for the detection of anti-Salmonella sp. antibodies in blood serum, and conventional bacteriology and biochemistry tests were used for bacterium culture and isolation. Data on the characteristics of the properties were obtained through medical records. The poultry rearing systems were classified as semi-intensive (49.0%) and extensive (42.6%). In these breeding systems, 48.0% were of specific breed free-range chickens and 42.0% of rustic rustic free-range chickens; 74.2% of the farms had commercial purpose. The frequency of properties with chicken seropositive to the anti-Salmonella sp. antigen was 16.3%, and 12.0% of the samples. Salmonella was detected in 4.7% of the properties and the identified serotypes were Anatum, Infantis, Mbandaka, Schwarzengrund and Panama. For Paper 2, we studied 44 flocks of chickens from nine poultry slaughterhouses, three with over 51,000 birds slaughtered/day and six with up to 50,000 birds slaughtered/day. On the slaughter line 1,232 organ samples and feathers were harvested. A total of 21 feather samples and 21 samples of each organ (spleen, crop and cecum) was collected, both of them were analyzed by conventional bacteriology and biochemistry tests. The organ samples were processed in groups of three, in a total of seven samples of each organ. Of the 44 flocks of chickens, 22 were positive for Salmonella. The feathers presented a higher positivity frequency (12.3%). The spleen presented the highest frequently of isolates (8.1%). The frequency of positive samples in both crop and cecum was 3.8%. Among 88 Salmonella isolates, the serovars Schwarzengrund (29.5%), Agona (25.2%), Mbandaka (12.6%), Anantum (8.0%) and Infantis (3.4%) were predominant. In conclusion, the non-conventional designs are characterized as semi-intensive, and use improved lineage of chickens for commercial purposes. Regardless of the levels of contamination, Salmonella sp. is present in chickens from both conventional and non-conventional production systems. The pathogen was identified in greater numbers in chicken organs at conventional farm. In non-conventional breeding samples, Salmonella sp. isolation was low, but the number of seropositive chickens was higher. The serovars identified in samples of both conventional and non-conventional systems were similar, and some of relevance to public health.
Salmonella sp. podem causar toxinfecção alimentar no homem e ser isolada do trato gastrintestinal de diferentes espécies animais, principalmente das aves. Objetivou-se com este estudo caracterizar os sistemas alternativos de criações avícolas nas regiões Central e Sul do Estado de Goiás e determinar a frequência de isolamento de Salmonella sp. em aves de criação alternativa e industrial, assim como a frequência de positividade da reação antígeno-anticorpo em soro de aves de criação alternativa. No artigo 1 estudou-se 190 propriedades de criações alternativas de frangos e em 760 aves colheram sangue e 3.040 amostras de órgãos, sendo coração, fígado, ceco e inglúvio. Realizou-se o teste de Soroaglutinação Rápida em Placa para detecção de anticorpos anti Salmonella sp. em soro sanguíneo e para cultura e isolamento da bactéria ultilizou-se bacteriologia convencional e provas bioquímicas. Os dados sobre as características das propriedades foram obtidos através de ficha de atendimento. As criações avícolas foram classificadas em semi-intensivas 49,0% e 42,6% extensivas. Observou-se que nestas criações as aves criadas são do tipo caipira melhorado 48,0% e 42,0% do tipo caipira rústico, e 74,2% das explorações têm a finalidade de comercialização. A frequência de propriedades com aves sororreagentes ao antígeno anti Salmonella sp. foi de 16,3%, e em amostras de 12,0%. Detectou-se Salmonella em 4,7% das propriedades e os sorovares identificados foram Anatum, Infantis, Mbandaka, Schwarzengrund e Panama. Para o artigo 2 o estudo foi realizado em 44 lotes de frangos de criação industrial de nove abatedouros, três com abate dia acima de 51.000 aves e seis com abate dia de até 50.000 aves dia. Na linha de abate colheram-se 1.232 amostras de órgão e penas. Num lote foram colhidas 21 amostras de penas e 21 amostras de cada órgão, sendo baço, ceco e inglúvio, ambas analisadas por bacteriologia convencional e provas bioquímicas. As amostras de órgãos foram processadas em pool de três, totalizando sete amostras para cada órgão. Dos 44 lotes de frangos, 22 foram positivos para Salmonella. As penas apresentaram maior frequência de amostras positivas (12,3%) e o baço foi o órgão com maior frequência de isolados (8,1%). A frequência de amostras positivas tanto para inglúvio quanto para ceco foi de 3,8%. Dentre os 88 isolados de Salmonella houve predominância do sorovar Schwarzengrund (29,5%), Agona (25,2%), Mbandaka (12,6%), Anantum (8,0%) e Infantis (3,4%). Conclui-se que as criações alternativas se caracterizam como do tipo semi-intensiva, utilizam aves de linhagem caipira melhorado com finalidade comercial. Independente dos níveis de contaminação, salmonella sp. está presente em aves dos sistemas industriais e alternativos de produção. O patógeno foi identificado em maior número em órgãos de frango de criação industrial. Em aves de criações alternativas obteve-se baixa frequência de isolamento do patógeno, mas obteve-se maior número de aves sororreagente. Observa-se que os sorovares identificados tanto em amostras de frango do sistema alternativo como do sistema industrial foram semelhantes, e alguns de relevância em saúde pública.

Questo lavoro di tesi è stato svolto sull’ impianto di produzione di polioli presso lo stabilimento Cargill di Castelmassa (RO) con lo scopo di ottimizzare la gestione dello ione Ni2+, derivante dal nichel metallico utilizzato come catalizzatore (nichel Raney) nella reazione di idrogenazione del glucosio condotta a 42 bar. Il nichel, infatti, a seguito di fluttuazioni di pH che avvengono durante il corso della reazione aumenta la sua solubilità passando in fase liquida sotto forma di ione bivalente. Nel successivo step di raffinazione e demineralizzazione del prodotto mediante una serie di resine a scambio ionico, il Ni2+ è trattenuto assieme ad altri ioni e separato dal prodotto stesso. Infine quando si va a rigenerare la resina, a seguito della sua saturazione, si producono dei reflui contenenti nichel, che, seppur presente in quantità modeste, non potranno essere inviati al depuratore comunale in quanto il metallo avvelenerebbe i microorganismi deputati al trattamento delle acque reflue, quindi dovranno essere smaltiti come rifiuti speciali. L’azienda è già dotata di un impianto di nichel recovery che utilizza una batteria di resine chelanti, in grado di catturare selettivamente metalli pesanti, in modo tale da avere un refluo con la concentrazione di Ni2+ più alta possibile per ridurre al minimo i costi, non esigui, di smaltimento. L’obbiettivo del mio lavoro di tesi è quello di trovare soluzioni alternative per la concentrazione del nichel e verificare mediante semplici bilanci economici se queste soluzioni proposte siano sostenibili dal punto di vista industriale, ed eventualmente possano essere concorrenti alla soluzione impiantistica già adottata.

The general area that was under consideration by this study is located in western Utah and eastern Nevada. The electronic combat test capability (ECTC) proposal potentially affected areas extending from the Great Salt Lake in the north to Milford, Utah in the south and from Eureka, Utah in the east to Ely, Nevada in the west. For most of this area potential impacts derived from the effects of air traffic. Construction and operation impacts would have occurred at various locations from throughout the study area. The largest concentration of both air flight and ground disturbance impacts would have occurred in one of three long valleys located south of the Dugway Proving Ground: Whirwind Valley, Tule Valley, and Snake Valley. These valleys are approximately 60 miles long and have a north to south orientation. The valleys are defined by mountain ranges with peaks from 7,000 to 12,000 feet elevation. Valley floors vary between 4,000 to 5,000 feet in elevation. So each valley involves different ecological zones that span as much as 8,000 vertical feet. This physically and ecologically diverse topography has been utilized by American Indian people for tens of thousands of years. For at least the past few hundred years it has been used by American Indian people belonging to the Goshute, Southern Paiute, and Ute ethnic groups. This report describes and summarizes the concerns of Goshute, Southern Paiute, and Ute Indian people for cultural resources that might have been potentially affected by proposed U.S. Air Force ECTC actions and alternatives in one of three candidate valleys in west - central Utah. Between March 6, 1989 and March 23, 1989, ethnographers from the Institute for Social Research at the University of Michigan, along with representatives of Science Applications International Corporation, Las Vegas, Nevada, and the United States Air Force, established a consultation relationship with four tribal governments who represent three American Indian ethnic groups involved in the cultural resources assessment study. During this time period, tribal representatives visited each of the three candidate valleys and the specific locations of proposed sites slated for potential ground disturbing activities and development within each candidate valley to comment on cultural resources that exist there.

Despite significant efforts have been directed toward reducing waste generation and encouraging alternative waste management strategies, landfills still remain the main option for Municipal Solid Waste (MSW) disposal in many countries. Hence, landfills and related impacts on the surroundings are still current issues throughout the world. Actually, the major concerns are related to the potential emissions of leachate and landfill gas into the environment, that pose a threat to public health, surface and groundwater pollution, soil contamination and global warming effects. To ensure environmental protection and enhance landfill sustainability, modern sanitary landfills are equipped with several engineered systems with different functions. For instance, the installation of containment systems, such as bottom liner and multi-layers capping systems, is aimed at reducing leachate seepage and water infiltration into the landfill body as well as gas migration, while eventually mitigating methane emissions through the placement of active oxidation layers (biocovers). Leachate collection and removal systems are designed to minimize water head forming on the bottom section of the landfill and consequent seepages through the liner system. Finally, gas extraction and utilization systems, allow to recover energy from landfill gas while reducing explosion and fire risks associated with methane accumulation, even though much depends on gas collection efficiency achieved in the field (range: 60-90% Spokas et al., 2006; Huitric and Kong, 2006). Hence, impacts on the surrounding environment caused by the polluting substances released from the deposited waste through liquid and gas emissions can be potentially mitigated by a proper design of technical barriers and collection/extraction systems at the landfill site. Nevertheless, the long-term performance of containment systems to limit the landfill emissions is highly uncertain and is strongly dependent on site-specific conditions such as climate, vegetative covers, containment systems, leachate quality and applied stress. Furthermore, the design and operation of leachate collection and treatment systems, of landfill gas extraction and utilization projects, as well as the assessment of appropriate methane reduction strategies (biocovers), require reliable emission forecasts for the assessment of system feasibility and to ensure environmental compliance. To this end, landfill simulation models can represent an useful supporting tool for a better design of leachate/gas collection and treatment systems and can provide valuable information for the evaluation of best options for containment systems depending on their performances under the site-specific conditions. The capability in predicting future emissions levels at a landfill site can also be improved by combining simulation models with field observations at full-scale landfills and/or with experimental studies resembling landfill conditions. Indeed, this kind of data may allow to identify the main parameters and processes governing leachate and gas generation and can provide useful information for model refinement. In view of such need, the present research study was initially addressed to develop a new landfill screening model that, based on simplified mathematical and empirical equations, provides quantitative estimation of leachate and gas production over time, taking into account for site-specific conditions, waste properties and main landfill characteristics and processes. In order to evaluate the applicability of the developed model and the accuracy of emissions forecast, several simulations on four full-scale landfills, currently in operative management stage, were carried out. The results of these case studies showed a good correspondence of leachate estimations with monthly trend observed in the field and revealed that the reliability of model predictions is strongly influenced by the quality of input data. In particular, the initial waste moisture content and the waste compression index, which are usually data not available from a standard characterisation, were identified as the key unknown parameters affecting leachate production. Furthermore, the applicability of the model to closed landfills was evaluated by simulating different alternative capping systems and by comparing the results with those returned by the Hydrological Evaluation of Landfill Performance (HELP), which is the most worldwide used model for comparative analysis of composite liner systems. Despite the simplified approach of the developed model, simulated values of infiltration and leakage rates through the analysed cover systems were in line with those of HELP. However, it should be highlighted that the developed model provides an assessment of leachate and biogas production only from a quantitative point of view. The leachate and biogas composition was indeed not included in the forecast model, as strongly linked to the type of waste that makes the prediction in a screening phase poorly representative of what could be expected in the field. Hence, for a qualitative analysis of leachate and gas emissions over time, a laboratory methodology including different type of lab-scale tests was applied to a particular waste material. Specifically, the research was focused on mechanically biologically treated (MBT) wastes which, after the introduction of the European Landfill Directive 1999/31/EC (European Commission, 1999) that imposes member states to dispose of in landfills only wastes that have been preliminary subjected to treatment, are becoming the main flow waste landfilled in new Italian facilities. However, due to the relatively recent introduction of the MBT plants within the waste management system, very few data on leachate and gas emissions from MBT waste in landfills are available and, hence, the current knowledge mainly results from laboratory studies. Nevertheless, the assessment of the leaching characteristics of MBT materials and the evaluation of how the environmental conditions may affect the heavy metals mobility are still poorly investigated in literature. To gain deeper insight on the fundamental mechanisms governing the constituents release from MBT wastes, several leaching experiments were performed on MBT samples collected from an Italian MBT plant and the experimental results were modelled to obtain information on the long-term leachate emissions. Namely, a combination of experimental leaching tests were performed on fully-characterized MBT waste samples and the effect of different parameters, mainly pH and liquid to solid ratio (L/S,) on the compounds release was investigated by combining pH static-batch test, pH dependent tests and dynamic up-flow column percolation experiments. The obtained results showed that, even though MBT wastes were characterized by relatively high heavy metals content, only a limited amount was actually soluble and thus bioavailable. Furthermore, the information provided by the different tests highlighted the existence of a strong linear correlation between the release pattern of dissolved organic carbon (DOC) and several metals (Co, Cr, Cu, Ni, V, Zn), suggesting that complexation to DOC is the leaching controlling mechanism of these elements. Thus, combining the results of batch and up-flow column percolation tests, partition coefficients between DOC and metals concentration were derived. These data, coupled with a simplified screening model for DOC release, allowed to get a very good prediction of metal release during the experiments and may provide useful indications for the evaluation of long-term emissions from this type of waste in a landfill disposal scenario. In order to complete the study on the MBT waste environmental behaviour, gas emissions from MBT waste were examined by performing different anaerobic tests. The main purpose of this study was to evaluate the potential gas generation capacity of wastes and to assess possible implications on gas generation resulting from the different environmental conditions expected in the field. To this end, anaerobic batch tests were performed at a wide range of water contents (26-43 %w/w up to 75 %w/w on wet weight) and temperatures (from 20-25 °C up to 55 °C) in order to simulate different landfill management options (dry tomb or bioreactor landfills). In nearly all test conditions, a quite long lag-phase was observed (several months) due to the inhibition effects resulting from high concentrations of volatile fatty acids (VFAs) and ammonia that highlighted a poor stability degree of the analysed material. Furthermore, experimental results showed that the initial waste water content is the key factor limiting the anaerobic biological process. Indeed, when the waste moisture was lower than 32 %w/w the methanogenic microbial activity was completely inhibited. Overall, the obtained results indicated that the operative conditions drastically affect the gas generation from MBT waste, in terms of both gas yield and generation rate. This suggests that particular caution should be paid when using the results of lab-scale tests for the evaluation of long-term behaviour expected in the field, where the boundary conditions change continuously and vary significantly depending on the climate, the landfill operative management strategies in place (e.g. leachate recirculation, waste disposal methods), the hydraulic characteristics of buried waste, the presence and type of temporary and final cover systems.

碩士
清雲科技大學
經營管理研究所
96
Recent decision research has explored the presence of extremeness aversion and compromise effect in choices. Extremeness aversion and compromise effect extend the principle of loss aversion. Based on the inference that the loss will not be observed significantly when alternatives’ price range in a choice set is narrower, the present research demonstrated that extremeness aversion and compromise effect are a function of alternatives’ price range in a choice set. Study 1 demonstrated that alternatives’ price range in a choice set has significant influence on extremeness aversion. In this regard, the proportion of choosing a middle option for a choice set with a wider price range will be significantly higher than the proportion for a choice set with a narrower price range. Furthermore, the proportion of choosing the middle option will be significantly higher than the proportion of choosing the extreme options when alternatives’ price range is wider. However, the middle option may not be favorable instead when alternatives’ price range is narrower. Study 2 demonstrated that alternative’s price range in a choice set significantly affects the compromise effect. In case an extreme option is added to a choice set with a wider price range, the proportion of choosing the middle option will be increased relatively. Study 3 demonstrated that price range in a choice set has significant influence on the proportion of choosing no choice option by consumers. In this regard, the proportion of choosing no choice option for a choice set with the same price range will be significantly higher than the proportion for a choice set with a wider price range. Furthermore, the proportion of choosing no choice option for a choice set with a wider price range will be significantly higher than the proportion for a choice set with a narrower price range.

Ascochyta blight (synonym: blackspot) is a serious, globally distributed, primarily foliar disease of Pisum sativum L. (field pea). It is typically caused by a combination of three or four fungal species that can exist independently of each other, called a complex. Phoma koolunga, identified in 2009 in South Australia, is the most recent addition in the Ascochyta complex. Despite multiple international studies on Ascochyta blight of field pea, P. koolunga has not been reported anywhere else in the world and the origins of the pathogen, and if it occurs on other legume species remain unknown. This study provides new information on the host range of P. koolunga on leguminous plants in controlled growth room conditions. To establish a host range, disease incidence and severity were assessed on 41 legume species comprising Australian native, weed, crop, pasture legumes and wild type Pisum, Lathyrus and Vicia species, following inoculation using two isolates of P. koolunga. All legumes tested, except Cicer arietinum (chickpea), developed leaf lesions and some also had stem and tendril lesions. Incidence and severity differed significantly among species but not consistently between isolates. The ability of the P. koolunga isolates to cause lesions on a wide range of legumes, including natives, in controlled environment conditions, suggests that it has a broad host range in humid and mild temperature conditions conducive for disease. Although all 17 native species developed some degree of leaf spotting, seven were considered susceptible because disease incidence was greater than 55 percent. This research also details the isolation, identification and classification of Didymellaceae fungi causing leaf spots, collected from legumes during field studies undertaken to investigate a possible native origin of P. koolunga. Samples from plants with leaf spots were collected from field pea growing regions throughout New South Wales, South Australia and Victoria taken back to the laboratory and cultured. The resultant fungal isolates were identified based on both morphology and phylogenetic analyses of the internal transcribed spacer region and part of the RNA polymerase II subunit B gene region. P. koolunga was not detected on native, weed or pasture legumes that had leaf spot symptoms in any of the regions visited, and only one isolate was recovered from field pea in the entire 2-year collection period. However, six novel species from the family Didymellaceae were isolated from Australian native legumes, five were from South Australia and one from New South Wales. The locations are represented by four different Australian Indigenous Peoples native language groups. Representatives of those groups were approached to request permission to use a suitable Aboriginal word for species epithet and permissions granted. These fungi are described here as Didymella djirangnandiri from Swainsona galegifolia, Didymella kaurna from Gastrolobium celsianum, Neodidymelliopsis tinkyukuku from Hardenbergia violaceae, Nothophoma garlbiwalawarda from Senna artemisioides, Nothophoma naiawu, and Nothophoma ngayawang also from S. artemisioides. Additional findings from the field collections were the identification of three new host-pathogen associations for Australia. Didymella pinodes, the primary pathogen responsible for Ascochyta blight of field pea, was isolated from leaf spots on naturalised species Vicia cracca (tufted vetch) in New South Wales and on Senna artemisioides from five different locations across South Australia. The discovery that these legumes may serve as an inoculum reservoir hosts for D. pinodes has implications for epidemiology and management of Ascochyta blight of field pea because both commonly occur in field pea growing regions throughout South Australia. Didymella lethalis was isolated from naturalised species, Lathyrus tingitanus (tangier pea), growing in a creek bed located in a well-used recreation area in Adelaide, South Australia. Phylogenetic analyses indicated that P. koolunga has a close relationship with the recently named species Ascochyta boeremae and supports the re-naming of P. koolunga as Ascochyta. Confirmation of the correction in nomenclature to Ascochyta koolunga comb. nov. was achieved with PCR followed by sequencing at two additional loci, the partial gene regions of ß-tubulin and the partial large subunit nrDNA (LSU). In summary, the controlled growth room results revealing a wide legume host range, and field collection results yielding no isolations from legumes other than field pea, suggest that P. koolunga is unlikely to have originated as a pathogen of Australian native legumes and provides no evidence regarding possible origins.
Thesis (MPhil) -- University of Adelaide, School of Agriculture, Food and Wine, 2020

Clearfelling of wet eucalypt forest followed by high intensity burning and aerial sowing, a silvicultural system used for the last 50 years in Tasmania and designed to mimic the natural dynamic of sporadic regeneration following cataclysmic disturbance, has attracted criticism for not maintaining the structural or floristic diversity that is associated with natural disturbance. To address these concerns, a silvicultural systems trial was established at the Warra Long-Term Ecological Research site in southern Tasmania to quantify the effect on these values if variable-retention harvesting systems are applied to tall wet eucalypt forest. The harvesting treatments were clearfell, burn and sow with understorey islands, a patchfell, stripfell, dispersed retention, aggregated retention, single-tree/small-group selection and group selection. High intensity burning, low intensity burning and no burning were variously applied as part of these treatments. Stocking, density and growth of the eucalypt seedling regeneration, floristic changes and the structural integrity of retained forest areas were monitored for up to ten years after harvesting and regeneration treatments were applied from 1998 to 2007. The nature of the seedbed in each coupe was related to the harvesting and regeneration treatment. Where high intensity burns were applied there was a higher proportion of burnt seedbed available than in coupes where low intensity burns were applied. The highest eucalypt seedling densities and fastest early growth rates occurred on the hottest burnt seedbeds. The lowest seedling densities occurred on unburnt and undisturbed seedbeds and the slowest early growth rates occurred on unburnt and compacted seedbeds. Treatments that created the most burnt seedbed had the highest eucalypt seedling densities and mean seedling growth rates. The floristic response in any given coupe following the harvesting and burning disturbance was related to the pre-harvesting floristics and not to the silvicultural system. Rainforest species present in the understorey prior to harvesting were also present in the post-harvesting vegetation, albeit at lower levels. Sclerophyll dominated understoreys regenerated with a very similar species composition to that pre-harvesting. Damage to the edges of retained forest areas was minimal, except for the smallest areas, which were prone to windthrow and were often burnt during the regeneration burn. Larger areas persisted intact throughout the harvesting and burning operations and for the first few years after those disturbances. Of the silvicultural systems examined in this study, aggregated retention is considered the most promising alternative to clearfelling. High intensity burns as applied to clearfell burn and sow coupes cannot be conducted in aggregated retention coupes as they would probably burn the aggregates. The lower proportion of burnt seedbed resulting will, on average, lead to lower seedling density and growth rates, and may compromise longer term productivity compared to clearfelled and high-intensity-burnt coupes. If aggregated retention is to be successfully applied, as measured by the density and height growth of the regeneration, finding ways of successfully and consistently burning such coupes post-harvesting will be essential.