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Klaus, Marcus. "Land use effects on greenhouse gas emissions from boreal inland waters." Doctoral thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-134767.
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Anthropogenic activities perturb the global carbon and nitrogen cycle with large implications for the earth’s climate. Land use activities deliver excess carbon and nitrogen to aquatic ecosystems. In the boreal biome, this is mainly due to forestry and atmospheric deposition. Yet, impacts of these anthropogenically mediated inputs of carbon and nitrogen on the processing and emissions of greenhouse gases from recipient streams and lakes are largely unknown. Understanding the ecosystem-scale response of aquatic greenhouse gas cycling to land use activities is critical to better predict anthropogenic effects on the global climate system and design more efficient climate change mitigation measures. This thesis assesses the effects of forest clearcutting and nitrate enrichment on greenhouse gas emissions from boreal inland waters. It also advances methods to quantify sources and sinks of these emissions. Short-term clearcut and nitrate enrichment effects were assessed using two whole-ecosystem experiments, carried out over four years in nine headwater catchments in boreal Sweden. In these experiments, I measured or modeled air-water fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), combining concentration, ebullition and gas-transfer velocity measurements in groundwater, streams and lakes. By using Swedish national monitoring data, I also assessed broad-scale effects of forest clearcutting by relating CO2 concentrations in 439 forest lakes to the areal proportion of catchment forest clearcuts. To improve quantifications of CO2 sources and sinks in lakes, I analyzed time series of oxygen concentrations and water temperature in five lakes on conditions under which whole-lake metabolism estimates can be inferred from oxygen dynamics given the perturbing influence of atmospheric exchange, mixing and internal waves. The experiments revealed that aquatic greenhouse gas emissions did not respond to nitrate addition or forest clearcutting. Importantly, riparian zones likely buffered clearcut-induced increases in groundwater CO2 and CH4 concentrations. Experimental results were confirmed by monitoring data showing no relationship between CO2 patterns across Swedish lakes and clearcut gradients. Yet, conclusions on internal vs. external CO2 controls largely depended on whether spatially or temporally resolved data was used. Partitioning CO2 sources and sinks in lakes using time series of oxygen was greatly challenged by physical transport and mixing processes. Conclusively, ongoing land use activities in the boreal zone are unlikely to have major effect on headwater greenhouse gas emissions. Yet, system- and scale specific effects cannot be excluded. To reveal these effects, there is a large need of improved methods and design of monitoring programs that account for the large spatial and temporal variability in greenhouse gas dynamics and its controls by abiotic and biotic factors.
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Aras, Sadiye. "Effects of Precipitation Changes on Switchgrass Biomass and Greenhouse Gas Emission." Thesis, Tennessee State University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10615045.
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Climate change and the energy crisis are two important issues we face in the world today. Bioenergy crops such as switchgrass could be very useful in solving these problems. But the interaction between switchgrass productivity and climate change, for example, precipitation changes, has not been well investigated. For this reason, we conducted a field precipitation experiment in Nashville, Tennessee, to study the effects of precipitation on switchgrass growth and soil respiration. Precipitation treatments included five levels: a control (ambient precipitation), +33%, +50% of ambient to simulate wet, and -33% and -50% of ambient to simulate drought treatments. We measured switchgrass physiology, roots, biomass, and soil respiration. Results showed that photosynthetic rates of switchgrass in the +33% and +50% treatments were about 19.5 µmol CO2 m-2 s-1, significantly higher than that in the other three treatments. The lowest one was found in the -50% treatment (17.26 µmol CO2 m-2 s-1). The biomass in the +50% treatment was the highest and the lowest was observed in the -50% treatment. The results indicate that, although switchgrass is a drought tolerant grass, high precipitation stimulates switchgrass photosynthesis and growth.
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Incemehmetoglu, Ali. "Investigation The Effects Of Different Support Medium On Product With Nutrient Film Technique." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615360/index.pdf.
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Hydroponics basically is the method of growing plants using mineral nutrient solutions, in water, without soil. Vertical nutrient film technique (NFT) is one of the most used hydroponic technique that has constant flow of nutrient solution. In this study the effects of different support medium on strawberry quality and yield using vertical NFT in glass greenhouse was investigated. NFT-only system was compared to rockwool, coco fiber, perlite and expanded clay as supporting medium for strawberry production. Parameters such as weight of product, amount of product, rate of marketable product, and including physico-chemical properties such as pH, rigidity, color, dry matter amount, EC, vitamin C, sugar content, resistance to certain pathogens were observed among all supporting medium trials. NFT-only system significantly differed from other supporting medium trails by most of the parameters including fruit number per plant, average fruit weight, toughness of the fruit, vitamin C amount, sugar amount and finally soluble solid material amount in water . Revealing the effects of supporting medium on strawberry production shed light on how should NFT must be applied to fruit growing.
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Winter, Barbara. "The effects of greenhouse-gas and surface thermal forcing on the stratosphere." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=96862.
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This thesis is concerned with the possible future changes in the stratosphere as a result of climate change. In this context, the climate change forcing can be separated into two components: (i) radiative forcing due to a doubling of the atmospheric CO2 mixing ratio, and (ii) surface thermal forcing. My focus is on the response in the circulation of the Northern Hemisphere stratosphere in winter. All experiments are carried out with a chemistry-climate model (CCM, i.e. an atmospheric general circulation model coupled to a chemistry model), the IGCM-FASTOC, and all results shown are averages over 100-year or 50-year simulations in timeslice mode (i.e. every year can be considered as one member of an ensemble having 50 or 100 members). This allows statistically robustresults in a region of high variability in the temperature and wind fields.When the IGCM-FASTOC is coupled to a mixed-layer slab ocean, the Arctic lower stratosphere in winter warms by up to 4K under 2xCO2 conditions, with associated weakening of the polar vortex and enhancement of the Brewer-Dobson circulation (BDC). This change is related to a significant increase in the Rossby wave forcing near the vortex core starting in January, followed by anincreased wave forcing at the lower edge of the polar vortex in February. Maximum wave forcing is found both to begin earlier in the winter and to be distributed over a longer period of time in the 2xCO2 climate. Results from four additional pairs of simulations (control and 2xCO2), in which sea and/or land surface temperatures were either calculated interactively, prescribed as a climatological cycle, or prescribed as interannually varying monthly-mean fields, demonstrate that the interannual variability in sea and land temperatures, and the adjustment of oceans and lands to the atmosphere and to one another, are essential in order to maintain realistic stratospheric forcing by Rossby waves and to adequately capture the stratospheric response to global warming. Specifically, when the land is interactive but the slab ocean is replaced by prescribed interannually varying monthly-mean temperatures, the stratospheric response is qualitatively similar to the fully interactive case, but has lower amplitude and is statistically significant over a smaller area.In the experiment without interannual variability, there is no response in stratospheric dynamics.To assess the impact of surface temperatures on the stratospheric circulation, a separate suite of experiments was carried out in which a 2K temperature anomaly was added to the control surface temperature at all gridpoints within latitudinal windows of 10 or 30 degrees. Thermal surface forcing applied anywhere equatorwards of 20N, or continuously from the equator to 30N, increases the generation of planetary waves in the troposphere, resulting in increased upward propagation. Consequently, a greater flux of wave activity enters the mid- to high latitude stratosphere and breaks in the polar vortex,increasing the BDC and leading to a warm anomaly in the polar stratosphere. Ozone concentration increases at high latitudes and decreases at low latitudes. Thermal surface forcing imposed between 30N and 60N has the reverse effect and leads to a stronger and colder vortex. Thermal forcing applied polewards of 60N has little effect on tropospheric baroclinicity, but results in a sufficientdecrease of the vertical flux of planetary wave activity that the vortex becomes anomalously strong and cold. In all cases when surface forcing is imposed only polewards of 30N, the ozone concentration decreases at high latitudes but is not affected at low latitudes. Combining the forcing in an equatorial and a mid-latitude band leads to a response similar to that of the equatorial forcing, demonstrating that the subtropical surface temperature changes dominate the sign of the surface-driven response in the vortex.Cette thèse étudie les possibles futurs changements dans la stratosphère dus au forçage par les changements climatiques. Dans ce contexte, les changements climatiques peuvent être séparés en deux composantes: (i) le forçage radiatif dû à un doublage de la concentration de CO2 dans l'atmosphère et (ii) le forçage thermique à la surface. L'emphase est mise sur la réponse dans lacirculation de l'Hémisphère nord en hiver. Toutes les expériences sont réalisées au moyen d'un modèle climat-chimie (un modèle de la circulation générale de l'atmosphère couplé à un modèle de chimie), le IGCM-FASTOC, et les résultats présentés sont les moyennes sur 100 ou 50 ans de simulations en mode répété (ou stationnaire, i.e. chaque année peut être considérée comme un membred'un ensemble ayant 100 ou 50 membres). Ceci permet d'aboutir à des résultats qui sont statistiquement significatifs dans une région où la température et les vents sont hautement variables.Lorsque le IGCM-FASTOC est couplé à un océan homogène de 25m de profondeur et que les températures de surface sont calculées de façon interactive, la réponse dans la basse stratosphère de l'Arctique à un doublage de CO2 est un réchauffement de 4K, accompagné d'un affaiblissement du vortex polaire et d'une augmentation de la circulation Brewer-Dobson (CBD). Ces changements sont reliés à une importante augmentation du flux vertical d'ondes Rossby, qui décélèrent le centre du vortex dès le mois de janvier, puis son bord inférieur en février. Le forçage maximal du vortex par les ondes débute plus tôt dans la saison hivernale et dure pour une plus grande période de temps dans le climat 2xCO2. Quatre paires de simulations supplémentaires (contrôle et 2xCO2) ontété réalisées, dans lesquelles les températures à la surface de l'océan et/ou de la terre étaient soit calculées de manière interactive, soit prescrites comme cycle climatologique fixe ou ayant une variabilité interannuelle. Ces expériences démontrent que la variabilité interannuelle, tout comme les ajustements des températures de surface à l'atmosphère ou des températures de la terre à celle des océans, sont essentielles pour maintenir un forçage réaliste du vortex par les ondes Rossby et donc pour capturer la réponse auxchangements climatiques de façon adéquate. Quand la surface terrestre est interactive mais l'océan couplé est remplacé par des températures imposées qui varient à l'échelle interannuelle, la réponse dans la stratosphère est qualitativement semblable à celle de l'expérience ayant l'océan interactif; par contre, cette réponse a une amplitude inférieure en plus d'être statistiquement significative sur une région moins importante. Les expériences sans variabilité interannuelle ne montrent aucun changement de la circulationdans la stratosphère.Pour évaluer l'importance du rôle de la température de surface dans la circulation stratosphérique, j'ai entrepris une nouvelle série d'expériences dans lesquelles une anomalie thermique de 2K est imposée à tous les points de grille à l'intérieur de bandes zonales larges de 10 ou de 30 degrés de latitude. Lorsque le forçage thermique est imposé à la surface entre 0N et 20N, ou de façon continue entre 0N et 30N, un plus grand flux d'activité ondulatoire accède à la stratosphère dans les moyennes et hautes latitudes. Les ondes se cassent dans le vortex, menant à une augmentation de la CBD et à une anomalie positive dans température de la stratosphère polaire. Un forçage thermique imposé à la surface entre 30N et 60N donne le résultat inverse, soit un vortex plus fort et plus froid. Le forçage thermique imposé à la surface au nord de 60N affaiblit suffisamment le flux vertical d'activité ondulatoire pour que levortex en résulte plus froid et plus fort également. Lorsque le forçage thermique est appliqué à la fois dans une bande équatoriale et dans une bande des moyennes latitudes, le forçage dans les subtropiques domine le signe de la réponse dans le vortex polaire.
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Simoes, Barneze Arlete. "Interactive effects of climate change and management on grassland greenhouse gas emissions." Thesis, Lancaster University, 2018. http://eprints.lancs.ac.uk/126417/.
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Climate warming has the potential to alter carbon (C) and nitrogen (N) cycling affecting greenhouse gas (GHG) emissions and a range of other ecosystem functioning in grasslands. This will be particularly important for the sustainability of agricultural ecosystems due to its role in global food security and soil C sequestration. The interaction between climate warming and grassland management is highly important and needs to be addressed as it may change the direction and strength of the effects on GHG emissions by changing plant productivity (either above and/or below-ground) and plant-soil properties. Plant species composition also plays a key role affecting the nutrient cycling thus GHG emissions in grasslands. The aim of this thesis is to understand how grassland management will influence C and N cycling under future climate change. The interactive effect of climate warming and grassland management is investigated in a field experiment over two growing seasons with varied microclimate effects, and the effect of plant composition manipulation in a controlled temperature mesocosm experiment. Overall, interactions between warming and management significantly affected GHG fluxes and plant-soil properties with important single treatment effects. The role that below-ground components plays on GHG emissions was less evident, becoming unclear the mechanisms related to gas releases to the atmosphere. Increases in legume proportions in grass-legume mixtures reduced ecosystem respiration in fertilised soils, with no effects in unfertilised soils. N cycling was not affected by increases in legume proportions. Plant productivity including above- and below-ground biomass had a non-linear relationship with relative legume proportion. Either grassland management or different plant species compositions approach may improve C sequestration and reduce GHG emissions.
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Shao, Miaolei. "The effects of greenhouse gas limits on electric power system dispatch and operations." Diss., Wichita State University, 2008. http://hdl.handle.net/10057/2079.
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Providing reliable, affordable, clean electricity is essential for national economic
performance and quality of life. A big challenge facing the electric power industry today is to meet the nation’s energy needs with the least environmental harm that results from electric power plants. The electric power industry is and will continue to be a primary focus of existing and future greenhouse gas (GHG) emission regulations. Different from other air pollutant regulations such as for sulfur dioxide (SO2) and nitrous oxides (NOx), GHG regulations have the potential to significantly affect electric power system dispatch and operations over a relatively short period, so the implications are significant enough to warrant an in-depth study. This dissertation first discusses climate change and the contribution from the electric power industry. Various climate change policies and corresponding research done in the electric power industry are presented, through which operators, planners, strategists, and investors can better understand the potential impacts of GHG regulations on the electric power industry. Then several primary power system features that will impact CO2 emissions are analyzed in this dissertation, using a simple two-bus two-generator power system. These power system features include CO2 emission factors by type of fuel used to generate power, unit thermal efficiency, regional generation mix, electricity demand, and transmission constraints. This dissertation then develops the CO2 emission-incorporated cost model, which includes a fuel cost function, CO2 emission cost function, and fuel-emission cost function. The implications of CO2 emission cost on generation dispatch related issues, such as generation cost variation and breakeven price of CO2, are studied. Based on the developed CO2 emission incorporated cost model, a powerful CO2 emission-incorporated ac optimal power flow has been formulated in this dissertation. The effects of the CO2 emission-incorporated ac optimal power flow on electric power system dispatch and operations were investigated using the standard IEEE 24-bus reliability test system through several case studies. These case studies consider situations of different fuel prices and different load levels. For each case study, a wide range of CO2 prices were modeled. Finally, in order to meet the annual CO2 emission limits economically, an integer programming based optimization methodology for implementing the proposed CO2 emission incorporated optimal power flow has been developed. The optimization methodology has been verified by various annual CO2 emission caps.Wichita State University, College of Engineering, Dept. of Electrical and Computer Engineering
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Mojeremane, Witness. "Effects of site preparation for afforestation on soil properties and greenhouse gas emission." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/4192.
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Forest plantations in the UK are often established on seasonally waterlogged peaty gley soils which often require site preparation (drainage and mounding) to lower the water table and prepare planting positions. Substantial changes in the physical environment of peaty gley soils can accompany site preparation including fluctuations in soil temperature and soil moisture. These and other changes can all affect soil properties and decomposition processes and well as the dynamics of CO2, CH4 and N2O. A field experiment was established at Harwood Forest (NE England) to investigate the effects of three site management practices (drainage, mounding and fertilisation) frequently used for afforestation and replanting on peaty gley soils in the UK on soil properties and various of C and N, environmental variables (soil temperature, water content and water table height) and emissions of CO2, CH4 and N2O. The relationship between GHG emissions and environmental variables was also examined. The experiment was laid out in a factorial split-plot design. Drainage decreased C and N concentration in the 10 cm soil layer. The soil bulk density in the 0 to 20 cm soil layer was increased by mounding. Drainage and fertilisation increased soil CO2 efflux, whereas mounding did not affect soil CO2 efflux. All three practices affected soil CH4 fluxes with drainage reducing the fluxes and mounding and fertilisation increasing the fluxes. Nitrous oxide emissions were significantly affected by mounding and fertilisation, with mounding decreasing emissions and fertilisation increasing emissions. Soil temperature was the main environmental factor controlling soil respiration in this site. Over the two years study drainage and fertilisation increased the total greenhouse budget by 13.1% and 97.9%, while mounding caused a reduction of−17.6%. Drainage plus mounding reduced the total greenhouse budget by 6.9%, while drainage plus mounding plus fertilisation increased the total greenhouse budget by 101.8%. There is a potential for up-scaling GHG emissions from newly drained peaty gley for inclusion in the UK Land Use Land-Use Change and Forestry (LULUCF) Greenhouse Gas Inventory. However up-scaling and evaluation of the net emissions requires high quality data from different sites newly drained for afforestation. More studies are needed if net fluxes from newly drained sites are to the included in the LULUCF Greenhouse Gas Inventory.
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Shao, Miaolei Jewell Ward T. "The effects of greenhouse gas limits on electric power system dispatch and operations /." A link to full text of this dissertation in SOAR, 2008. http://hdl.handle.net/10057/2079.
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Alazzawi, Sheymaa. "DESIGNING A SMART GREENHOUSE VENTILATION WINDOW BASED ON NITI SMA ACTUATOR." OpenSIUC, 2019. https://opensiuc.lib.siu.edu/dissertations/1703.
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A multi-functional (sensing -actuating) greenhouse ventilation window heated/cooled naturally by convection was designed to overcome different industry challenges in terms of designing smart applications. This ventilation window design includes a three-pulley system to reduce the load on the NiTi actuator and enhance its long-life time. In addition, using the NiTi actuator allows energy saving due to natural phase transformation induction (i.e. convection) and high force generation compared to the small NiTi wire mass. Structural analysis was used to determine the force generated in the “C-shaped” NiTi wire after loading. Transient thermal and structural analysis also was used to investigate the strain rate effects on the shape memory response of “C shaped” NiTi alloy element under different thermomechanical loadings and boundary conditions. Two types of loading have been applied isothermally or at adiabatic conditions. The results showed a significant effect of the high loading rates on increasing the stress plateau which is caused by the corresponding shift in the transformation temperatures. As a result, it could be expected that the actuator life time could be reduced when a rapid, as opposed to a slow loading rate, is adopted. In addition, the dynamic loading of the NiTi leads to a decrease of the recoverable strain. Experimental work was done to validate the simulation model by testing a commercial NiTi sample dynamically and compare the macroscopic displacement during mechanical loading and the strain recovery process.
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Ventura, Robert E. "Wetlands and Greenhouse Gas Fluxes: Causes and Effects of Climate Change – A Meta-Analysis." Scholarship @ Claremont, 2014. http://scholarship.claremont.edu/pomona_theses/107.
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Climate change is one of the largest problems facing this generation. Anthropogenically caused increases of greenhouse gas emissions is a significant culprit to this problem. Although the obvious problems such as cars, industry, and urbanism garnish a significant amount of the criticism, natural sources such as wetlands are also beginning to contribute to this issue. This is becoming increasingly significant as wetlands shift from being sinks of greenhouse gases to becoming sources as various anthropogenic impacts, including global warming itself, begin to affect the health of the wetlands. The aim of this project is to look at four common types of wetlands, being tropical mangroves, temperate coastal marshes, inland meadows, and subarctic peatlands, all located in different climactic areas of the world, and by doing a meta-analysis of available data of greenhouse gas production for each wetland type, observe how differences in their greenhouse gas production may contribute or be affected by climate change and global warming. Results of the meta-analysis revealed that the most significant production of the potent greenhouse gas nitrous oxide occurs in coastal wetlands such as tropical mangroves and coastal marshes, while the greenhouse gas methane is seen to be produced most in subarctic peatlands. These contributions of wetlands to global greenhouse gas production are not as significant as other anthropogenic contributions. However, subarctic wetlands contribute to more than half of the global methane emissions, and the most important aspect of wetland greenhouse gas production is that they are producing more greenhouse gases than they would normally be sequestering, contributing more than the basic greenhouse gas production data can display. Global climate changes such as temperature increase and sea level rise could also make these levels of greenhouse gas production become worse, although measures to decrease the effects of this such as regulations on anthropogenic nitrogen input, macrophyte presence, and prevention of peat burning.
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Devlin, Andrew John. "Structural effects of the built environment on vehicle greenhouse gas emissions : evidence from Vancouver, Canada." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/17460.
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This thesis summarizes efforts to estimate fundamental relationships among built environment characteristics, activity patterns and vehicle use in order to assess their relative influences on vehicle GHG emission generation in Metro Vancouver, Canada. Activity-based structural equation models were specified in a cross-sectional study design using local travel survey data and highly detailed urban form data. Structural equation analysis permitted explicit modeling of the indirect effects between built environment variables and vehicle emissions as mediated through activity patterns and vehicle use. Modeling travel at the activity-tour level allowed for a deeper understanding of the relative contributions of local and regional built environment variables in explaining tour complexity, vehicle use and emissions. Controlling for pertinent socio-economic and demographic variables, standardized parameter coefficients show the built environment to be a significant predictor of vehicle-related GHG emissions across all models, although the strength and magnitude of these effects vary by activity tour type. The local built environment is a stronger predictor of vehicle use and related emissions for non-work/school tours, while regional accessibility measures yielded larger effects on the carbon-intensity of work and school tours. Vehicle accessibility yielded significantly large effects on vehicle use and emissions across all models, suggesting that policy directions beyond promoting more compact, walkable and regionally connected development to curb emissions are required. Additional strategies may include those that address vehicle use in a more direct manner, including higher taxation, insurance or parking fees. Future research would benefit by incorporating travel and residential preferences to control for self-selection, assessing the affect of the work and school built environment on activity patterns and undertaking a more holistic assessment of the links between the built environment and total household emissions and energy use (including building, transportation, etc).
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Crowley, Kathryn Jane. "Effects of colored plastic film on several field grown and greenhouse grown cut flower species." Auburn, Ala., 2007. http://repo.lib.auburn.edu/2007%20Fall%20Theses/Crowley_Kathryn_6.pdf.
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Mihail, J. D., J. K. Brown, and M. R. Nelson. "The Effects of Cotton Leaf Crumple on Greenhouse-Grown Cotton Incoulated at Five Growth Stages." College of Agriculture, University of Arizona (Tucson, AZ), 1987. http://hdl.handle.net/10150/204510.
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The effects of cotton leaf crumple disease on components of yield and on symptom expression were examined for cotton inoculated at five growth stages. As a result of virus infection, the total leaf area was reduced and significant reductions in yield were observed, regardless of plant age at time of inoculation. Yield reductions resulted from a smaller number of bolls set and/or a decrease in boll weight. Foliar symptoms were associated with plants inoculated at all five growth stages, but were observed sooner and were more severe for plants inoculated at the 2-3, 5-8, and 8-10 leaf stages than those inoculated at the 14-16 or 18-20 leaf stages.
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Guzy, Jr Darrel James. "20th century warming: what fractions are fromanthropogenic greenhouse gases and from natural on solar effects?" Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46732780.
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Walley, Justin W. "THE EFFECTS OF LOW-LEVEL CADMIUM TOXICITY ON FIELD AND GREENHOUSE GROWN SOYBEAN (GLYCINE MAX)." Miami University / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=miami1133229744.
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Haghighi, Maryam, Atena Sheibanirad, and Mohammad Pessarakli. "Effects Of Selenium as a Beneficial Element on Growth and Photosynthetic Attributes of Greenhouse Cucumber." Taylor & Francis, 2015. http://hdl.handle.net/10150/615120.
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Selenium (Se) is an essential element for human and livestock with antioxidant and anticancer characteristics. Although Se is not an essential element for plants, it has been reported that it can improve plant growth. This experiment was conducted at the Isfahan University of Technology in winter 2010. The experiment was factorial based on a completely randomized design (CRD) with 4 replications. Se was added to nutrient solution in 4 concentrations 2, 4, and 6 mg/l sodium selenite (Na2SeO3). Root volume, fresh and dry weights of shoots and roots, number and weight of fruits, chlorophyll content and photosynthesis traits (photosynthesis rate, stomata internal carbon dioxide (CO2) concentration, stomata conductance) were measured. Results showed that Se increased root dry weight. Fresh and dry weights of shoot increased in the 2 mg/l Se treatment and decreased at the higher level of Se. Chlorophyll content and photosynthesis rate were not affected by Se. Stomata internal CO2 concentration and stomata conductance decreased by Se addition. Overall, Se at 2 mg/l application rate was effective in some physiological characteristics of cucumber.
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Stratton, Russell William. "Life cycle assessment of greenhouse gas emissions and non-CO₂ combustion effects from alternative jet fuels." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/59694.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 135-144).
The long-term viability and success of a transportation fuel depends on both economic and environmental sustainability. This thesis focuses specifically on assessing the life cycle greenhouse gas (GHG) emissions and non-CO 2 combustion effects from conventional jet fuel and synthetic paraffinic kerosene (SPK). The research expands upon the work of Wong (2008) by examining Fischer-Tropsch jet fuel from coal and biomass, and hydroprocessed renewable jet (HRJ) fuel from rapeseed, jatropha, algae and salicornia. Each fuel option is a "drop-in" alternative in that they are compatible with existing aviation infrastructure. Using a modified version of the APMT climate impacts module, the additional climate forcing from non-CO 2 combustion effects is combined with the fuel life cycle GHG inventories. Life cycle GHG emissions are only one of many aspects that must be considered when evaluating the feasibility and sustainability of an alternative fuel option. While cost and fresh water availability are important constraints, fuel yield and land requirements for select biomass-based fuel pathways are quantified. This is most important for feedstocks requiring cropland for cultivation. For example, current global production of soy, palm and rapeseed oil translate to only 34%, 43% and 18% of US jet fuel demand, respectively; hence, even small fractions of the petroleum industry translate to massive production scales in absolute terms. By comparison, HRJ from algal oil can yield more than an order of magnitude higher fuel production per hectare of land. Few biofuels were identified with zero life cycle GHG emissions. This contradicts previous studies and likely results from avoiding the displacement method to allocate emissions. Considerable inter and intra fuel option variability was found in life cycle GHG emissions; land use change contributed much to the variability of many pathways. The range in life cycle GHG emissions of all fuel options examined ranged from 0 to 9.1 times those of conventional jet fuel. The uncertainty in treating non-CO 2 combustion effects was found to have a larger influence on the life cycle emissions of each fuel option than the variability of the life cycle GHG inventories; however, including non-CO 2 combustion effects reduced the overall range in emissions of all fuel options considered to only 0 to 4.7 times those of conventional jet fuel. Hence, the inclusion of non-CO 2 effects in the fuel life cycle increases the absolute uncertainty of each fuel option but reduces the overall variability in the life cycle emissions of alternative fuels relative to conventional jet fuel.
by Russell William Stratton.
S.M.
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施錦杯 and Kam-pui Sze. "Effects of the interaction of atmosphere and ocean on humanactivities." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31254378.
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Sonnenberg, Donavon Mark. "The effects of various drip fertigated water quantities on hydroponically cultivated Cucumis sativa L." Thesis, Cape Peninsula University of Technology, 2012. http://hdl.handle.net/20.500.11838/2026.
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Thesis (MTech (Horticulture))--Cape Peninsula University of Technology, 2012.The effects of various water quantities were assessed on Cucumber (Cucumis sativa L.) grown hydroponically in the greenhouse. The objectives of the study were to evaluate influence of water quantities on: i) photosynthesis and chlorophyll content of Cucumis sativa L.; ii) the nutrient uptake in Cucumis sativa L. iii) flavonoid and anthocyanin metabolism in Cucumis sativa L. and iv) growth and yield in Cucumis sativa L. The treatments included 8 various water regimes (21/h, 41/h, 61/h, 81/h, 101/h, 121/h, 141/h and 161/h. The plants received water five times a day, making it 10, 20, 30, 40, 50, 60, 70, and 80 litres per day. Results showed that generally the Photosynthetic rate (A), intercellular CO2 concentration (Cj) and stomata conductance (gs) and the transpiration rate of the cucumber plants were significantly increased by increasing water quantities compared with lower water quantities. Additionally, there were significant improvements in leaf colour in weeks 2, 3, 4, 5, 6, 7 and 8. Overall, the foliage colour was improved as water supply was increased. The greener leaves were documented in treatments supplied with higher water doses. Additionally, the chlorophyll content of cucumber plants was increased significantly with varying water quantities. The highest chlorophyll contents were found in plants treated with 161/h.
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Sze, Kam-pui. "Effects of the interaction of atmosphere and ocean on human activities /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21301414.
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Zisimopoulos, Dimitrios, Linnéa Thor, and Malin Frisk. "Reduced water consumption and related greenhouse gas emissions : A study of the effects of Uppsalahem’s watersavings campaign in 2013." Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-225601.
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The purpose of this project is to evaluate the effects of a campaign that Uppsalahem implemented in February 2013, in order to make their tenants consume less water. The result of the campaign is evaluated in terms of reduced water usage and reduced emissions of greenhouse gas related to the heating of the water through district heating. Four different residential areas in urban Uppsala, where Uppsalahem implemented their water saving campaign have been studied. All calculations are done in MATLAB. The results regarding water usage is presented in cubic meters and the greenhouse gas emissions are presented in terms of carbon dioxide equivalents. A sensitivity analysis of the data is performed in order to study natural occurring variances of water consumption over time. In order to determine which parameter has the greatest impact on reducing carbon dioxide emissions, a sensitivity analysis of the fuel mix used at the district heating power plant is made. The results show that there has been a reduction of water usage since after the campaign was implemented and the sensitivity analysis of the data indicates that there has been an especially large decrease in water consumption between the years 2012 and 2013. Further though, the results contain monthly irregularities in water usage in the different areas. This shows that the reduction of water consumption has not been temporally associated to the campaign, which indicates that the reduction might not be an effect of the campaign. Regarding carbon dioxide emissions, the sensitivity analysis indicates that the kind of fuel mix Vattenfall use at their district heating plant has a much greater impact than the individual water usage behaviors of the tenants.
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Poonpun, Piyasak. "Effects of low carbon emission generation and energy storage on greenhouse gas emissions in electric power systems." Diss., Wichita State University, 2009. http://hdl.handle.net/10057/2380.
Full textAbstract:
The electric power industry produces substantial amounts of carbon dioxide (CO2) as
well as other greenhouse gas (GHG) emissions. Recent GHG regulations along with renewable
portfolio standards encourage the integration of low carbon emission generation into the electric
power system and, as a result, drastically affect operations, design, and planning of the electric
power system. Extensive studies on this issue, therefore, are important.
This dissertation first discusses renewable standards and policies in the United States
(U.S.), which include renewable portfolio standards. Current U.S. electricity markets for
renewable generators such as wind generation resources and solar power plants are investigated.
This research analyzes several factors that affect an electric power system due to the integration
of these low carbon generators.
The dissertation then develops system operating cost models for renewable generation
and energy storage. With consideration of CO2 emission costs, the system operating cost model
for a fossil-fired generating unit is presented and discussed.
By using optimal power flow, security-constrained optimal power flow, time step series
input, and the CO2 emissions incorporated objective function, this dissertation develops a new
methodology to study the effects of low carbon emission generation and energy storage on GHG
emissions in electric power systems.
A number of relevant study cases are presented. The cost models and methodology are
applied to the study cases. The IEEE 24 bus Reliability Test System (IEEE RTS) is used as the
sample test system. This system has been modified to include additional generation fuels to study
the amount of various CO2 emissions.
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Simulation results, including system operating costs, total emissions, economic dispatch,
and locational marginal prices, are presented and discussed. This dissertation addresses two
major issues: system operating cost and system reliability. Finally, conclusions are drawn and
discussed, and future work is recommended. Conclusions include:
• The integration of renewable generation reduces CO2 but emissions of reserve units must
be considered.
• The integration of low carbon emission generation tends to reduce system operating cost.
The system operator still must consider the operating cost of renewable generators and
reserve fossil-fired generators.
• The change of emissions and system operating cost are not proportional to the additional
capacity of renewable generation installed due to complexities of an electric power
system.
• The system operating cost model for renewable generation is able to properly represent
the special characteristics of these low carbon emission generators. The proposed
operating cost model for energy storage can also be used to verify its effects on overall
system cost and emissions.
• The developed methodology can be used to investigate an electric power system with
integrated renewable generation and energy storage. It has the ability to consider several
factors and unique characteristics of renewable generation, energy storage, and the
transmission system.
• Generation output profiles of low carbon emission generation significantly affect total
CO2 emissions of an electric power system.Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical and Computer Engineering
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Menichino, Nina Marie. "The effects of restoration on biodiversity, water quality and greenhouse gas fluxes in a rich fen peatland." Thesis, Bangor University, 2015. https://research.bangor.ac.uk/portal/en/theses/the-effects-of-restoration-on-biodiversity-water-quality-and-greenhouse-gas-fluxes-in-a-rich-fen-peatland(de08dda4-6ffe-4932-9559-0a72c3c69480).html.
Full textAbstract:
Rich fens are globally significant wetlands due to their high biodiversity and provision of multiple ecosystem services, such as water purification and climate mitigation. However, many U.K. rich fens have become botanically degraded. This is principally due to abandonment, following the cessation of management (mowing/grazing) and has led to a decline in plant species richness. Although the response to mowing on plant species richness has been well documented across Europe, there is no prior knowledge of this research being undertaken at U.K rich fens. Additionally, the effects of mowing on water quality are largely unquantified. Furthermore, the spatial heterogeneity of greenhouse gases across and within botanically rich and botanically poor sites is also unknown. Two rich fen plant communities: Cladio-Molinietum (n=9) and Scheonus nigricans - Juncus subnodulosus (n=8) were examined across three sites; chosen for their conservation value and current degraded condition. A 50 % success rate was achieved following mowing to increase species richness, which meant assumptions were not met for both plant communities. Nitrate, phosphate and dissolved organic carbon concentrations did not reduce following mowing, however there was a beneficial increase in concentration of base cations at both sites. The greenhouse gas investigation revealed that the net gaseous carbon flux between both sites was comparable, which did not meet expectations that the botanically impoverished site would have higher carbon emissions, however, expected differences between plant communities were observed at both sites. Therefore, this study shows the complexity of the botanical, hydro-chemical and greenhouse gas spatial heterogeneity at rich fens. Careful examination prior to restoration is needed to determine whether environmental/ecological barriers have been removed, so that restoration is not in any way inhibited. In addition, this study has demonstrated that objectives for biodiversity may be in conflict with objectives to manage for other ecosystem services, in these multi-functional wetlands.
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Khan, Gulzar Ahmed. "Acidification and nitrogen oxide : a survey of Asian soils and the effects of nitric oxide on fungi in an experimental model." Thesis, King's College London (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265830.
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Ann, Varughese Merrie. "Mulching and tillage effects on GHG emissions and properties of an Alfisol in Central Ohio." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1322596901.
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Gacengo, Catherine N. Wood C. W. Shaw Joey N. "Agroecosystem management effects on carbon and nitrogen cycling across a coastal plain catena." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Agronomy_and_Soils/Dissertation/Gacengo_Catherine_2.pdf.
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Lynes, Melissa Kate. "Production efficiencies of U.S. electric generation plants: effects of data aggregation and greenhouse gas and renewable energy policy." Diss., Kansas State University, 2015. http://hdl.handle.net/2097/19781.
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Doctor of PhilosophyDepartment of Agricultural Economics
Jeffery R. Williams
Over the last few decades there has been a shift in electricity production in the U.S. Renewable energy sources are becoming more widely used. In addition, electric generation plants that use coal inputs are more heavily regulated than a couple decades ago. This shift in electricity production was brought on by changes in federal policy – a desire for electricity produced in the U.S. which led to policies being adopted that encourage the use of renewable energy. The change in production practices due to policies may have led to changes in the productivity of electric generation plants. Multiple studies have examined the most efficient electric generation plants using the data envelopment analysis (DEA) approach. This study builds on past research to answer three questions: 1) Does the level of aggregation of fuel input variables affect the plant efficiency scores and how does the efficiency of renewable energy input compare to nonrenewable energy inputs; 2) Are policies geared toward directly or indirectly reducing greenhouse gas emissions affecting the production efficiencies of greenhouse gas emitting electric generation plants; and 3) Do renewable energy policies and the use of intermittent energy sources (i.e. wind and solar) affect the productivity growth of electric generation plants. All three analysis, presented in three essays, use U.S. plant level data obtained from the Energy Information Administration to answer these questions. The first two essays use DEA to determine the pure technical, overall technical, and scale efficiencies of electric generation plants. The third essay uses DEA within the Malmquist index to assess the change in productivity over time. Results indicate that the level of aggregation does matter particularly for scale efficiency. This implies that valuable information is likely lost when fuel inputs are aggregated together. Policies directly focused on reducing greenhouse gas emissions may improve the production efficiencies of greenhouse gas emitting electric generation plants. However, renewable energy policies do not have an effect on productivity growth. Renewable energy inputs are found to be as efficient if not more efficient than traditional energy sources.
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Battaglia, Martin. "Crop residue management effects on crop production, greenhouse gases emissions, and soil quality in the Mid-Atlantic USA." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/86483.
Full textAbstract:
Cellulosic biomass-to-bioenergy systems can provide environmental and economic benefits to modern societies, reducing the dependence on fossil-fuels and greenhouse gas emissions while simultaneously improving rural economies. Corn (Zea mays L.) stover and wheat straw (Triticum aestivum L.) residues have particular promise given these crops are widely grown and their cellulosic fractions present a captured resource as a co-product of grain production. Annual systems also offer the ability to change crops rapidly in response to changing market demands. However, concerns exist about residue removal effects on soil health, greenhouse gases emissions and subsequent crop productivity. The carbon footprint and the crop yield productivity and soil health responses resulting from the removal of crop residues has been studied extensively over the last 20 years, but this research has been largely conducted in the Corn Belt. To investigate the impact of crop residue removal in the Mid-Atlantic USA, combinations of corn stover (0, 3.33, 6.66, 10 and 20 Mg ha-1) and wheat straw (0, 1.0, 2.0, and 3.0 Mgha-1) were soil applied in a corn-wheat/soybean (Glycine max L. Merr.) rotation in Virginia's Coastal Plain. Corn stover (0, 3.33, 6.66, 10 and 20 Mg ha-1) was applied in a continuous corn cropping system in the Ridge/Valley province. For each system, residues were applied following grain harvest over two production cycles. Each experiment was conducted as a randomized complete design with four replications. The highest rates of stover retention resulted in greater greenhouse gas emissions in year 1, but not year 2 of these studies and did not affect overall global warming potentials. Stover application also increased soil carbon but had little effect on other measures of soil quality. Stover K levels were greater with high rates of stover retention. Overall, these studies indicate little effect of residue removal or retention (above typical residue production rates) on subsequent crop production, greenhouse gas emissions, or soil health measures in the short term. This study is one of the first to assess residue removal in the Mid-Atlantic USA and is the first study to investigate the impacts that managing more than one crop residue in a multi-crop system. Longer-term research of this type may be warranted both to determine the consequences of residue management and to start building a regionally-specific body of knowledge about these practices.Ph. D.
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Oates, David Luke. "Low Carbon Policy and Technology in the Power Sector: Evaluating Economic and Environmental Effects." Research Showcase @ CMU, 2015. http://repository.cmu.edu/dissertations/502.
Full textAbstract:
In this thesis, I present four research papers related by their focus on environmental and economic effects of low-carbon policies and technologies in electric power. The papers address a number of issues related to the operation and design of CCS-equipped plants with solvent storage and bypass, the effect of Renewable Portfolio Standards (RPS) on cycling of coal-fired power plants, and the EPA’s proposed CO2 emissions rule for existing power plants. In Chapter 2, I present results from a study of the design and operation of power plants equipped with CCS with flue gas bypass and solvent storage. I considered whether flue gas bypass and solvent storage could be used to increase the profitability of plants with CCS. Using a pricetaker profit maximization model, I evaluated the increase in NPV at a pulverized coal (PC) plant with an amine-based capture system, a PC plant with an ammonia-based capture system, and a natural gas combined-cycle plant with an amine-based capture system when these plants were equipped with an optimally sized solvent storage vessel and regenerator. I found that while flue gas bypass and solvent storage increased profitability at low CO2 prices, they ceased to do so at CO2 prices high enough for the overall plant to become NPV-positive. In Chapter 3, I present results from a Unit Commitment and Economic Dispatch model of the PJM West power system. I quantify the increase in cycling of coal-fired power plants that results when complying with a 20% RPS using wind power, accounting for cycling costs not usually included in power plant bids. I find that while additional cycling does increase cycling-related production costs and emissions of CO2, SO2, and NOX, these increases are small compared to the overall reductions in production costs and air emissions that occur with high levels of wind. In proposing its existing power plant CO2 emissions standard, the Environmental Protection Agency determined that significant energy efficiency would be available to aid in compliance. In Chapter 4, I use an expanded version of the model of Chapter 3 to evaluate compliance with the standard with and without this energy efficiency, as well as under several other scenarios. I find that emissions of CO2, SO2, and NOX are relatively insensitive to the amount of energy efficiency available, but that production costs increase significantly when complying without efficiency. In complying with the EPA’s proposed existing power plant CO2 emissions standard, states will have the choice of whether to comply individually or in cooperation with other states, as well as the choice of whether to comply with a rate-based standard or a mass-based standard. In Chapter 5, I present results from a linear dispatch model of the power system in the continental U.S. I find that cooperative compliance reduces total costs, but that certain states will prefer not to cooperate. I also find that compliance with a mass-based standard increases electricity prices by a larger margin than does compliance with a rate-based standard, with implications for the distribution of surplus changes between producers and consumers.
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Arias-Navarro, Cristina [Verfasser], Klaus [Akademischer Betreuer] Butterbach-Bahl, and Heinz [Akademischer Betreuer] Rennenberg. "Spatial variability of greenhouse gas (GHG) fluxes in tropical systems of East Africa: Effects of land use and topography." Freiburg : Universität, 2017. http://d-nb.info/1154385752/34.
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Tapiwa, Chikwanda Allen. "Effects of grazing and housing management systems on greenhouse gas emissions, blood profiles and meat quality of Nguni goats." Thesis, University of Fort Hare, 2016. http://hdl.handle.net/10353/2314.
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The broad objective of this study was to evaluate the effects of grazing and housing management systems on greenhouse gas emissions, blood profiles and meat quality of Nguni goats. A total of 64 castrated Nguni goats were used and a housing structure was designed to accommodate the goats as well as evaluate effects of type of floor on greenhouse gases, meat quality, blood metabolites and fatty acid profiles. In the first experiment: Forty-eight castrated Nguni goats, at 6-7 months old were used for herding (H) or tethering (T) management systems and randomly allocated to pens with earth (E) or slatted (S) floors. Gas sampling was done using static chambers and analysed using a SRI 8610C gas chromatography machine. The highest CH4 fluxes were from the manure of herded goats on earth floors (HE). The highest CO2 fluxes were from manure of herded goats that were housed on slatted floors (HS): The highest N2O fluxes were from the manure of tethered goats that were sheltered on slatted floors (TS). It was concluded from the first experiment that goat manure is an important source of GHG that is influenced by grazing and floor type management systems. The second experiment was done to evaluate greenhouse gas (GHG) emission from disused (DP) vs occupied goat pens (OP) with earth (EF) or slatted (SF) floors. Eight previously occupied pens were used in this study. Sixteen goats were randomly put in the pens labelled occupied pens with earth floors (OPEF) and occupied pens with slatted floors (OPSF) resulting in four goats per OP. There were month by pen use; month by floor type; and use by floor type interaction effects (P < 0.05) on CH4 production. Floor type, use (DP vs OP) and month affected (P < 0.05) CH4 production. Manure on earth floors of occupied pens (OPEF) emitted the highest (P < 0.05) methane followed by earth floors of disused pens (DPEF). The least CH4 was emitted from DPSF. There was pen use (DP vs OP) by floor type interaction effect (P < 0.05) on CO2 emission. Floor type and pen use affected (P < 0.05) CO2 production. Manure in occupied pens with slatted floors (OPSF) produced the highest CO2 and the least CO2 was from disused pens with slatted floors (DPSF). Floor type and month influenced (P < 0.05) N2O production. It was concluded that continued use of goat pens increased GHG emissions. However, disused goat pens with manure remain an important source of GHG as they continued to emit quantifiable levels of CH4, CO2 and N2O. The third experiment was done to determine the effects of grazing and housing management systems on the concentrations of blood metabolites, activity of creatine kinase, body weight (BW), body condition score (BCS) and carcass characteristics using 48 castrated Nguni goats. Tethered goats had higher (P<0.05): urea, creatinine, total protein, globulin concentrations and more activity of CK than herded goats. On the other hand, herded goats had higher (P<0.05) plasma glucose (H: 3.39±0.020 vs T: 3.23±0.020 mmol/L), serum albumin (H: 15.30±0.147 vs T: 14.82±0.144 g/L) concentration. It was concluded that serum concentrations of all the metabolites and the activity of CK were sensitive to grazing system. Herding of goats promoted more glucose concentration and preservation of muscle protein and hence superior body weights and BCS than tethered goats. The fourth experiment was done to determine the effects of grazing and housing management systems on the activity of creatine kinase (CK) and cortisol concentration, and chevon quality. Further, the effect of muscle type [Muscularis longissimus thoracis et. Lumborum (LTL) and triceps brachii (TB)] on chevon quality was also investigated. Forty eight castrated Nguni goats aged 6- 7 months were randomly allocated to tethering (n=24) and herding (n=24) treatments. Floor type affected meat (P<0.05) pH24. Tethered goats had higher (P < 0.05) L* and CL percent than herded goats. Muscle type had a significant influence (P < 0.05) on a*, WBSF and pH. It was observed and concluded that T resulted in higher L* and more CL percent whilst SF lowered the pH24 of chevon; at the same time meat from the TB muscle was more tender, despite having a higher pH24 and more CL percent relative to LTH cuts. The fifth experiment was done to determine the effect of grazing and floor type on fatty acid composition of chevon from tethered and herded Nguni goats. Floor type had no effect on fatty acid composition. Oleic, stearic, palmitic and linoleic were the major fatty acids. Chevon from tethered goats had higher (P < 0.05) proportions of long chain polyunsaturated fatty acids (PUFAs): eicosapentaenoic, docosapentaenoic, docosahexaenoic, conjugated linoleic acid (CLA) and more total SFA, total PUFA, total Omega- 6 and total omega 3 fatty acids than herded goats. On the other hand, chevon from herded goats had more (P < 0.05) C18:1c9, C18:2t9, 12 (n-6), C20:3c11, 14, 17 (n-3) and total MUFA than tethered goats. However, there was no difference (P > 0.05) in the PUFA: SFA and n-6/n-3 fatty acid ratios between the herded and tethered goats. It was concluded that tethering promoted higher proportions of beneficial PUFAs which were more in TB than LTH muscle. The overall conclusions from the whole study were that goat manure is an important source of GHG with high CH4 being emitted from earth floors of herded goats. High CO2 and N2O are emitted from SF of herded and tethered goats, respectively. There were no major differences in meat quality between herded and tethered goats. However, herding promoted more live weight gain than tethering. On the other hand, tethering promoted more beneficial fatty acids. Therefore depending on the objective of the enterprise, smallholder farmers can safely tether or herd their goats. Further, there is need to develop technologies to harness CH4 from goat manure.
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Haji, Sabli Haji Mohd Zamri. "Fertigation of Bell Pepper (Capsicum annuum L.) in a soil-less greenhouse system : effects of fertiliser formulation and irrigation frequency." Thesis, University of Newcastle Upon Tyne, 2012. http://hdl.handle.net/10443/1543.
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Increasing costs and more limited availability of water and fertiliser, coupled with mounting concern over nutrient leaching damaging the environment has led to greater interest in improved methods of managing these inputs. Greenhouse horticulture could, until recently, be characterised by large fertiliser inputs and low fertiliser use efficiency. Adoption of fertigation (application of fertilisers through irrigation water) within greenhouse production systems brings the potential for close control of both water and fertiliser applications. It is claimed that timing, amounts and ratios of fertilisers applied are easily controlled leading to optimisation of yield and product quality. However efficient operation of fertigation systems is hampered by lack of data on optimum consumption rates of essential nutrients by important crops as functions of time. The biological, chemical and physical database on fertigation is still very limited and simple extrapolation of the data to different climatic and substrate conditions may lead to operational errors. The aim of this research study was to evaluate the effects of varying fertiliser concentration and irrigation frequency on growth and yield of greenhouse bell pepper (Capsicum annuum L.) grown in rockwool using a fertigation system. A study on responses to varying nitrogen and potassium concentrations at different growth stages showed that increasing N from 126mg l-1 to 265mg l-1 and 385mg l-1 and increasing K from 106 mg l-1 to 214mg l-1 and 321mg l-1 increased fruit yield significantly over the control. Higher yield was associated with higher leaf area and total dry matter production, better quality fruits and better nutrient uptake. Indications were that recommended doses of nutrients in soil-less culture should change according to the growth stage of the crop with the fertigation program being adjusted during the growing season to suit plant development. In another experiment, effects of varying nitrogen and potassium rates and ratios on growth, yield, and the incidence of blossom - end rot (BER), leaf chlorophyll content, Fertigation of bell pepper (Capsicum annuum L.) in a soil-less greenhouse system photosynthetic aspects and NPK uptake was investigated. Phosphorus concentration (55mg l-1) was kept constant whilst N:K ratio varied. Increasing the NPK concentration from low concentration (44-55-71 mg l-1) to high concentration (126-55-106 mg l-1) significantly increased growth and yield with no further increases up to 500-55-625 mg l-1. Plants subjected to high NPK concentration in the second and third stage had more fruits with BER. The implications are that nutrient management must avoid too low and too high fertiliser concentrations and carefully manage electrical conductivity (EC) of nutrient solution in order to achieve high yield and quality whilst reducing nutrient leaching to the environment. The ability of fertigation systems to increase irrigation frequency affords a major advantage to crop production. As no research had examined effects of irrigation frequency at different growth stages an experiment was made to quantify the potential benefits of more frequent irrigation. With 20 irrigation events day-1 throughout the season, yield increased significantly by 22% over the control (5 irrigation events day-1 throughout the season). Higher yield was associated with taller and thicker plants, higher leaf area, greater total dry matter production, bigger fruits and better NPK uptake. The difference in growth and yield over the control could be attributed to differences in leaf phosphorus concentration, indicating the main effect of fertigation frequency was related to improved phosphorus mobilisation and uptake. Increasing the daily fertigation frequency from five to twenty irrigation events day-1 significantly reduced BER incidence. A final experiment examined effects of defoliation (removal of older, lower leaves) which may influence nutrient use efficiency and dry matter production and partitioning. There were four treatments: two irrigation schedules (5 and 10 irrigation events per day) and two defoliation strategies (0% defoliation and 20% of lower leaves removed). Defoliated plants reduced yield compared to non-defoliated plants irrespective of fertigation frequency because of less leaf area, lower total dry matter production and lower NPK uptake. Clearly, defoliation caused by leaf eating insects, disease or deliberate removal by the grower should be avoided or yield is likely to suffer.
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Lemes, Ernane Miranda. "Foliar and soil applied silicon effects on Asian soybean rust (Phakopsora pachyrhizi) development in soybean under greenhouse and field conditions." [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0041351.
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Adjuik, Toby A. "Effects of Hydrochar, Digestate, Synthetic Fertilizer on Soil Greenhouse Gas Fluxes in Miscanthus x giganteus Grown as Advanced Biofuel Feedstock." Ohio University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1557220009015982.
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Kiyumi, Khalifa Salem Muhammad. "Greenhouse cucumber production systems in Oman: A study on the effects of cultivation practices on crop diseases and crop yields." Thesis, University of Reading, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.485712.
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The greenhouse sector in Oman has expanded significantly since 2001. With expansion have come problems associated with the production system. A comprehensive survey of current farmer practice in relation to production and protection activities was conducted in northern Oman in 2001-2004. Results showed an annual increase in greenhouse number of over 40% per year. A number of serious problems associated with greenhouse crop production were identified, in particular: (1) over reliance on a single crop (cucumber), (2) substantial losses due to pests and diseases, especially damping-off caused by Pythium aphanidermatum, (3) dependence on pesticides for pest and disease control, especially for damping-off disease, (4) excessive application of irrigation water ~d fertilizers. A database of locations of all farms with greenhouses in northern Oman was made using GPS information and analysed using GIS techniques. Factors were identified which cause clustering ofgreenhouses in certain locations, including proximity to markets and centres ofpopulation. Other factors such as high irrigation .' water salinity levels were identified as disincentives to greenhouse expansion. Natural epidemics of damping-off varied greatly in their temporal and spatial dynamics. Temporal progress was most rapid in the wanner seasons. Spatial dynamics were affected by temperature and position within the greenhouse. Results showed limited variation in pathogenicity among P. aphanidermatum isolates. Disease severity was negatively related to . . plant age, but positively related to temperature up to 3SoC. In the latter case this is a reflection of P. aphanidermaturrt growth in vitro. Comparisons between current fanner irrigation and fertilizer inputs and reduced inputs under controlled condit~ons showed that yield and profitability of cucumber production could be increased from current levels. An analysis of· ~. economic factors related to greenhouse crop production indicated that yield was closely related to total cost of production, but not to h~vels of pesticide input, suggesting inefficiencies in pest and disease management practices.
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Qu, Jingwen. "Timing effects of carbon mitigation and solar radiation management policies." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43720.
Full textAbstract:
We study timing effects of carbon mitigation and solar radiation management (SRM) policies for correlated pollutants, CO₂ and SO₂. We show that national levels of carbon and sulfur emissions quotas and SRM implementation are positively correlated with each other. First-mover advantages exist when deciding both carbon quotas and SRM levels. Moreover, we use an example to illustrate that if international equity is considered, governments would be willing to choose SRM levels before carbon quotas since it yields higher payoffs and less acid rain and droughts damages. This timing was neglected by all previous theoretical economic models on geoengineering.
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Sonnenberg, Donovan Mark. "The effects of various drip fertigated water quantities on hydroponically cultivated Cucumis sativa L." Thesis, Cape Peninsula University of Technology, 2012. http://hdl.handle.net/20.500.11838/839.
Full textAbstract:
Thesis submitted in fulfilment of the requirements for the degree
Master of Technology: Horticulture
in the Faculty of Applied Sciences
at the Cape Peninsula University of Technology, 2012The effects of various water quantities were assessed on Cucumber (Cucumis sativa L.) grown hydroponically in the greenhouse. The objectives of the study were to evaluate influence of water quantities on: i) photosynthesis and chlorophyll content of Cucumis sativa L.; ii) the nutrient uptake in Cucumis sativa L. iii) flavonoid and anthocyanin metabolism in Cucumis sativa L. and iv) growth and yield in Cucumis sativa L. The treatments included 8 various water regimes (2l/h, 4l/h, 6l/h, 8l/h, 10l/h, 12l/h, 14l/h and 16l/h. The plants received water five times a day, making it 10, 20, 30, 40, 50, 60, 70, and 80 litres per day. Results showed that generally the Photosynthetic rate (A), intercellular CO2 concentration (Ci) and stomata conductance (gs) and the transpiration rate of the cucumber plants were significantly increased by increasing water quantities compared with lower water quantities. Additionally, there were significant improvements in leaf colour in weeks 2, 3, 4, 5, 6, 7 and 8. Overall, the foliage colour was improved as water supply was increased. The greener leaves were documented in treatments supplied with higher water doses. Additionally, the chlorophyll content of cucumber plants was increased significantly with varying water quantities. The highest chlorophyll contents were found in plants treated with 16l/h. The fresh and dry weights of roots, leaves and stems were significantly (P≤0.001) influenced by different water quantities supplied to Cucumis sativa L. The largest quantity of fresh roots was recorded in the control treatment (2l/h) in comparison with all other treatments. However, the best growth with regard to fresh and dry weights of leaves and stems were recorded by supplying the water quantities ranging from 10-16l/h. Altering water supply significantly (P≤0.001) affected the uptake of nitrogen, phosphorous, potassium, calcium, sodium, copper, zinc, aluminium and iron in roots of Cucumis sativa L. Irregular results were recorded in the uptake of these nutrients in the roots. However, leaf uptake of N, P, K, Ca, magnesium, sulphur, Cu, Zn, manganese, boron, and Al responded significantly (P≤0.001) to the different water quantities. The best result for each was observed at quantities involving 16l/h. In stems of cucumber water quantities significantly (P≤0.001) affected the uptake of N, P, K, Ca, Mg, Na, S, Cu, Zn, Mn and B. The highest uptake of N, P, Ca, Mg and S were found at the maximum supply of water (16l/h) compared with the control (2l/h). Sodium uptake showed irregular patterns, whereas K and Zinc uptake peaked at 14l/h. The data from this study showed that flavonoid metabolism was not significantly affected by the different water quantities supplied to cucumber plants. However, the anthocyanin content in roots, leaves, and stem was significantly influenced by water levels. The lowest water quantity (2-6l/h) significantly increased the levels of anthocyanins in all tissues tested. Increasing water quantities significantly decreased the anthocynanin metabolism in all tissues. Plant height displayed significant differences with water quantities from weeks 1-8. In week 1, the plant height was superior at supplying 4l/h in comparison with other treatments. In week 2 and 5 irregular trends were detected. At weeks 3 and 4, plants supplied with 8-12l/h displayed superior plant height performance. At weeks 7-8, significant and optimal results were observed at water quantities ranging from 4-16l/h compared with the control treatment. Water quantities significantly (P≤0.001) affected the number of leaves per plant from weeks 2-8. Irregular results were displayed in weeks 2 and 3. At weeks 4 and 5, the highest numbers of leaves were in water quantities of 12l/h and 10l/h, respectively. Generally, leaf numbers increased with increasing water levels from weeks 6-8. Plant vigour was significantly affected by the alteration of water quantities at weeks 1, 2, 4, 5, 6, 7 and 8. At weeks 1 and 4, more vigorous plants were found in the treatments that received from 10-16 l/h. At weeks 2 and 5, optimal results were found at treatments that received from 6-14l/h. At weeks 6, 7 and 8, the most vigorous plants were found at the highest water quantity of 16l/h. With fruit length, fruit width, rind colour, fruit quality (marketable fruit) and weight, results from the harvest done in the first, second and third week showed that water quantities significantly influenced these parameters. Optimal results were reported when the plants were supplied with water ranging between 14-16l/h. During harvesting at week 4, the fruit length, width, rind colour, were of marketable quality at 16l/h. Generally, the plants that received highest amount of water (16l/h) had the highest cucumber yields compared with all other treatments. Higher water quantities in this study resulted in increased physiological responses such as photosynthesis and nutrient uptake which resulted in the higher fruit yields. In water-limited environments, results from this study could assist growers with reasonable cucumber yields while saving water for other farm uses.
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McKean, Thomas. "Effects of Soilless Substrate Systems and Environmental Conditions on Yield, Total Soluble Solids, and Titratable Acidity of Greenhouse Strawberry (Fragaria × ananassa)." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1566167238648805.
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Garrison, Trent. "The Environmental Effects of Coal Fires." UKnowledge, 2015. http://uknowledge.uky.edu/ees_etds/31.
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There are thousands of subterranean coal fires in the world that, because of incomplete combustion, emit a wide variety of volatile and semivolatile organic compounds to the atmosphere, water, and soil at concentrations that could pose health risks to humans and wildlife. The main goals of this study were to (1) review methods that are used to characterize physical and chemical characteristics of coal-fire sites, (2) determine relationships between gas emissions and physical and chemical characteristics of coal-fire sites, using a combination of regression and multivariate statistical methods, and (3) determine the concentrations of volatile and semivolatile organic compounds in water and soil at two coal-fire sites in eastern Kentucky. More specifically:
The objective of Chapter 1 was to review past works and list technologies used over time. Eight years of coal-fire collection technologies were reviewed. A variety of methods and technologies were identified. Qualitative and quantitative preferences were noted.
The objective of Chapter 2 was to identify and list uncontrolled coal-fire variables. These variables include complete/incomplete combustion; fire temperature and size; distance to fire; relative humidity and moisture in the system; geology, geochemistry, and age of coal; condition of the mine, sampling time of day; sampling equipment differences; and human error. A secondary objective of this chapter was to determine which coal-fire gases have strong relationships by using the principal component analysis (PCA) software JMP. The strongest relationship was between CO and H2S. Temperature and CH4 were also important. This indicates that incomplete combustion and polynuclear aromatic hydrocarbon (PAH) formation are likely occurring, setting the stage for Chapter 3.
The objective of Chapter 3 was to identify and define the extent of soil and water hydrocarbon contamination at the Truman Shepherd and Lotts Creek coal fires in eastern Kentucky. No groundwater contamination was detected at either location. Soil contamination was found at both, but was much higher at Lotts Creek, potentially because of sorption onto soil organic matter (which is reduced at Truman Shepherd by an excavation attempt) and other physicochemical mechanisms. Soil contamination was localized to relatively small areas around coal-fire vents.
Based on the results, future studies should consider: Attempting to duplicate these results in other geologic regions Quantifying greenhouse gas emissions from coal fires to consider their contribution to climate change. Coal-fired power plants are regulated, but coal fires, which produce many more harmful gases, are not Determining the feasibility of an oxygen-injection system to engender more complete combustion, therefore possibly reducing harmful gases Determining the feasibility of electricity production from coal fires Adopting a consistent federal coal-fire policy
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Tatsiopoulou, Angeliki. "Effects of manipulation of light quality in the greenhouse environment with photoselective films on vegetative and reproductive growth of contrasting horticultural crops." Thesis, University of Reading, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417326.
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Murray, Cameron Keith. "New insights into rebound effects : theory and empirical evidence." Queensland University of Technology, 2009. http://eprints.qut.edu.au/27655/.
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The main objective of the thesis is to seek insights into the theory, and provide empirical evidence of rebound effects. Rebound effects reduce the environmental benefits of environmental policies and household behaviour changes. In particular, win-win demand side measures, in the form of energy efficiency and household consumption pattern changes, are seen as ways for households and businesses to save money and the environment. However, these savings have environmental impacts when spent, which are known as rebound effects. This is an area that has been widely neglected by policy makers.
This work extends the rebound effect literature in three important ways, (1) it incorporates the potential for variation of rebound effects with household income level, (2) it enables the isolation of direct and indirect effects for cases of energy efficient technology adoption, and examines the relationship between these two component effects, and (3) it expands the scope of rebound effect analysis to include government taxes and subsidies.
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Using a case study approach it is found that the rebound effect from household consumption pattern changes targeted at electricity is between 5 and 10%. For consumption pattern changes with reduced vehicle fuel use, the rebound effect is in the order of 20 to 30%. Higher income households in general are found to have a lower total rebound effect; however the indirect effect becomes relatively more significant at higher household income levels. In the win-lose case of domestic photovoltaic electricity generation, it is demonstrated that negative rebound effects can occur, which can potentially amplify the environmental benefits of this action.
The rebound effect from a carbon tax, which occurs due to the re-spending of raised revenues, was found to be in the range of 11-32%. Taxes and transfers between households of different income levels also have environmental implications. For example, a more progressive tax structure, with increased low income welfare payments is likely to increase greenhouse gas emissions. Subsidies aimed at encouraging environmentally friendly consumption habits are also subject to rebound effects, as they constitute a substitution of government expenditure for household expenditure. For policy makers, these findings point to the need to incorporate rebound effects in the environmental policy evaluation process.’
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Eckerhall, Daniel. "The Possibility and Effects of Including the Transport Sector in the EU Emission Trading Scheme." Thesis, Linköping University, Department of Mechanical Engineering, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-5306.
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The European Union has initiated a scheme for trading with CO2 emission allowances as a measure to reduce greenhouse gas emission levels. Since January 2005 companies from certain energy demanding sectors, responsible for approximately 50 % of the total CO2 emissions in the EU, are participating in this scheme, the so called EU Emission Trading Scheme.
A trading scheme covering all sectors, i.e. all emissions in the EU would lead to the most cost efficient solution to reduce emissions by a certain amount. This means that the EU Emission Trading Scheme should be enlarged to cover also the transport sector, which is not participating today, but responsible for about 21 % of the total greenhouse gas emissions in the EU.
There are three ways to include the transport sector in the EU Emission Trading Scheme, i.e. to administrate the handling and trading of emission allowances in the transport sector. The first is a so called downstream approach, meaning that the actual emitter of the GHG, in this case a private person driving a car or a haulage contractor using trucks to transport goods, would be responsible for acquiring and trading emission allowances in accordance to the amount of greenhouse gases that he emits. The second way is a so called upstream approach, meaning that the owner of fuel depots would be responsible for acquiring and trading emission allowances corresponding to the amount of fossil fuel that he is selling, which is proportional to the amount of greenhouse gases that is emitted when using the fuel. The third solution is to lay the responsibility for acquiring and trading emission allowances on the companies that are ordering the transportation service, indirectly causing greenhouse gas emissions when their goods are being transported.
All three solutions have their advantages and disadvantages, but the benefits of using the upstream approach are the greatest. By allocating the responsibility for keeping and trading emission allowances at the fuel depots, an extensive part of greenhouse gas emissions from fossil fuel use, not only in the transport sector, could be covered by the EU Emission Trading Scheme to the lowest administrational cost possible.
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Quaas, Johannes, Jean-Louis Dufresne, Olivier Boucher, and Treut Hervé Le. "Impacts of greenhouse gases and aerosol direct and indirect effects on clouds and radiation in atmospheric GCM simulations of the 1930-1989 period." Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-189692.
Full textAbstract:
Among anthropogenic perturbations of the Earth\'s atmosphere, greenhouse gases and aerosols are considered to have a major impact on the energy budget through their impact on radiative fluxes. We use three ensembles of simulations with the LMDZ general circulation model to investigate the radiative impacts of five species of greenhouse gases (CO2, CH4, N2O, CFC-11 and CFC-12) and sulfate aerosols for the period 1930-1989. Since our focus is on the atmospheric changes in clouds and radiation from greenhouse gases and aerosols, we prescribed sea surface temperatures in these simulations. Besides the direct impact on radiation through the greenhouse effect and scattering of sunlight by aerosols, strong radiative impacts of both perturbations through changes
in cloudiness are analysed. The increase in greenhouse gas concentration leads to a reduction of clouds at all atmospheric levels, thus decreasing the total greenhouse effect in the longwave spectrum and increasing absorption of solar radiation by reduction of cloud albedo. Increasing
anthropogenic aerosol burden results in a decrease in high-level cloud cover through a cooling of the atmosphere, and an increase in the low-level cloud cover through the second aerosol indirect effect. The trend in low-level cloud lifetime due to aerosols is quantified to 0.5 min day-1 decade-1 for the simulation period. The different changes in high (decrease) and low-level (increase) cloudiness due to the response of cloud processes to aerosols impact shortwave radiation in a contrariwise manner, and the net effect is slightly positive. The total aerosol effect including also the aerosol direct and first indirect effects remains strongly negative.
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Quaas, Johannes, Jean-Louis Dufresne, Olivier Boucher, and Treut Hervé Le. "Impacts of greenhouse gases and aerosol direct and indirect effects on clouds and radiation in atmospheric GCM simulations of the 1930-1989 period." Laboratoire de Météorologie Dynamique, 2004. https://ul.qucosa.de/id/qucosa%3A13985.
Full textAbstract:
Among anthropogenic perturbations of the Earth\''s atmosphere, greenhouse gases and aerosols are considered to have a major impact on the energy budget through their impact on radiative fluxes. We use three ensembles of simulations with the LMDZ general circulation model to investigate the radiative impacts of five species of greenhouse gases (CO2, CH4, N2O, CFC-11 and CFC-12) and sulfate aerosols for the period 1930-1989. Since our focus is on the atmospheric changes in clouds and radiation from greenhouse gases and aerosols, we prescribed sea surface temperatures in these simulations. Besides the direct impact on radiation through the greenhouse effect and scattering of sunlight by aerosols, strong radiative impacts of both perturbations through changes
in cloudiness are analysed. The increase in greenhouse gas concentration leads to a reduction of clouds at all atmospheric levels, thus decreasing the total greenhouse effect in the longwave spectrum and increasing absorption of solar radiation by reduction of cloud albedo. Increasing
anthropogenic aerosol burden results in a decrease in high-level cloud cover through a cooling of the atmosphere, and an increase in the low-level cloud cover through the second aerosol indirect effect. The trend in low-level cloud lifetime due to aerosols is quantified to 0.5 min day-1 decade-1 for the simulation period. The different changes in high (decrease) and low-level (increase) cloudiness due to the response of cloud processes to aerosols impact shortwave radiation in a contrariwise manner, and the net effect is slightly positive. The total aerosol effect including also the aerosol direct and first indirect effects remains strongly negative.
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Chen, Tsu-Wei [Verfasser]. "Architectural and non-architectural effects of salinity on canopy structure, light interception and dry mass production on greenhouse cucumber and tomato / Tsu-Wei Chen." Hannover : Technische Informationsbibliothek und Universitätsbibliothek Hannover (TIB), 2015. http://d-nb.info/1080267271/34.
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Ogutu, Rose Atieno. "Calcined materials as components of soilless root media : phosphate sorption characteristics and effects on phosphate and water use in greenhouse production of Impatiens wallerana." Diss., Manhattan, Kan. : Kansas State University, 2008. http://hdl.handle.net/2097/720.
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Flachenecker, Florian. "Competitiveness and climate change mitigation : empirical evidence on the effects of material use and material productivity on competitiveness and greenhouse gas emissions in Europe." Thesis, University College London (University of London), 2018. http://discovery.ucl.ac.uk/10040758/.
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Aligning competitiveness with climate change mitigation objectives lies at the heart of contemporary discourses on sustainable development, resource efficiency, green growth, and the circular economy. While numerous scholars and policymakers, particularly in Europe, follow the notion that decreasing material use and increasing material productivity can boost competitiveness and help to mitigate climate change, the empirical evidence underlying this assertion has put little emphasis on two important issues. First, many studies predominantly rely on case studies, often not considering dynamic effects and heterogeneity across firms, sectors, countries, material subgroups, and material indicators. Second, the majority of investigations do not address the potential problem of endogeneity in empirical models. This dissertation attempts to shift the focus on these and other issues having received relatively little scrutiny in the existing literature by four interrelated analyses on European economies and firms. First, the effect of material use on greenhouse gas (GHG) emissions is empirically assessed, finding a robust and positive link mostly driven by fossil fuel use. Second, it is investigated whether economic growth is a driver of material use, suggesting that economic growth causes an increase in material use for Western European countries. Third, the effects of material productivity on indicators of macroeconomic competitiveness and GHG emissions are investigated, finding little evidence for any statically significant link, except of increased average wages and improvements in the current account. Fourth, the effects of eco-innovation induced material productivity increases on microeconomic competitiveness and firm level GHG emissions are studied, providing evidence that material productivity increases microeconomic competitiveness and reduces GHG emissions. However, these effects are heterogeneously distributed across sectors and countries. Overall, this dissertation draws a nuanced picture by providing new evidence that material use and material productivity can support competitiveness and climate change mitigation objectives, but such benefits are likely to be unequally distributed across firms, sectors, and countries. To this end, the results provide important policy insights, including that weight-based material indicators are linked to GHG emissions, internalising externalities is essential, and eco-innovations can enable certain firms, sectors, and countries to grasp the benefits of material productivity improvements. Moreover, it is important to further investigate the implications of moving towards more material productive economies based on greater emphasis on heterogeneity, endogeneity, and improved data.
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Rodriguez, Wilmer Mauricio. "Effects of Elevated CO2 on Growth, Development, Nutrient Concentration and Insect Performance of Plants Grown at Sub-Optimal Temperature." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1299603101.
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Mahony, Christopher Paul. "Effects of native ectomycorrhizal fungi on aspen seedlings in greenhouse studies: inoculation methods, fertilizer regimes, and plant uptake of selected elements in smelter-impacted soils." Thesis, Montana State University, 2006. http://etd.lib.montana.edu/etd/2005/mahony/MahonyC0505.pdf.
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In southwestern Montana, areas near Butte and Anaconda support little or no vegetation mainly because of impacts from copper mining. Aspen (Populus tremuloides) stands occur naturally in these areas and rely heavily on native mycorrhizal fungi to moderate below ground conditions. Aspen associates with over 60 species of mycorrhizal fungi, but only a subset occurs on acidic, low nutrient soils. For these reasons, and the fact that aspen is an important colonizing tree on disturbed landscapes, a study was undertaken to examine aspen and its native ectomycorrhizal fungi in pot studies for future use in reclamation projects. The first goal was to develop a method for mycorrhization of aspen in the greenhouse by examining inoculation methods, fertilization regimes, and selection of fungi. Nine native ectomycorrhizal fungi from smelter impacted sites near Butte- Anaconda aspen stands were tested using seed from Silverbow county, MT. Results demonstrated that mycorrhization of aspen in the greenhouse is possible, and that banding is the most effective method, although also labor intensive. Some fertilization was necessary, and high levels of liquid soluble fertilizer dramatically reduce mycorrhization, while the time release fertilizer Osmocote allowed mycorrhization. In general, mycorrhization in peat:vermiculite reduced aspen growth at 3 months, which might reflect an initial carbon drain. Secondly, effects of ectomycorrhizal fungi on aspen growth and metal uptake in pots from Smelter Hill and Mt. Haggin were examined. In contrast to our earlier findings, mycorrhization in field soils increased seedling growth, although controls were slightly compromised. Inoculation technique was important and only banded seedlings formed mycorrhizae. Copper uptake was depressed about 50% in both roots and shoots of banded aspen compared to seeding a soil inoculum. Iron, zinc, nickel and phosphorus uptake appeared affected by fungi, but was dependent on species and particular metal, and, in some cases, appeared enhanced. Laccaria, Paxillus, Pisolithus and Scleroderma are of interest for their impact on aspen growth and metal uptake characteristics. Results indicate that inoculation of aspen seedlings with native mycorrhizal fungi has potential for use on smelter-impacted field soils. Once established, aspen's clonal nature could be an advantage in re-vegetating large tracts of land.
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Doukas, Dimitrios E. "Effects of ultraviolet-absorbing plastic films on the behaviour of greenhouse whitefly Trialeurodes vaporariorum and its parasitoid Encarsia formosa : potential use in insect pest management." Thesis, University of Reading, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.421628.
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