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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

SIMULAÇÃO DO DESENVOLVIMENTO, CRESCIMENTO E PRODUTIVIDADE DE SOJA EM CONDIÇÕES CLIMÁTICAS ATUAIS E FUTURAS PARA O RIO GRANDE DO SUL / SIMULATING DEVELOPMENT, GROWTH, AND YIELD OF SOYBEAN UNDER CURRENT AND FUTURE CLIMATE FOR THE RIO GRANDE DO SUL

Cera, Jossana Ceolin 18 February 2016 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Soybean is a mainly agricultural world commodity, with United States, Brazil, and Argentina as mainly producers. This thesis had as objectives (i) evaluate the SoySim model to simulate growth, development, and yield of soybean cultivars with maturity groups greater than 4.2 in a subtropical region of Brazil and (ii) simulate the soybean yield potential and rainfed in the Rio Grande do Sul State in two climate futuro scenarios of IPCC (SRES A1B and RCP4.5) with the crop models SoySim and CROPGRO-Soybean. To reach the first objective, were used data from field experiments with 20 soybean cultivars, in 38 diferent sowing dates during 2010/2011, 2011/2012, 2012/2013, 2013/2014 and 2014/2015 growing seasons, in 12 locations at Rio Grande do Sul State. The soybean cultivars have maturity group varying between 4.8 and 8.2 and indeterminate and semi-determinate growth habit. The evaluation of the SoySim model show reasonable simulations of the variables of the V-stage and R-stage, final node number, and yield, but in general, the simulations that had the lower errors, were those with maturity groups lower than 6.0. For the second objective, the simulations with the emission scenarios SRES A1B and RCP4.5 forcing the crop models SoySim and CROPGRO-Soybean showed an increase on soybean yield in Rio Grande do Sul State until the end of the XXI century, with a positive change around 2 Mg ha-1 for the 2070-2099 period related to the baseline (1980-2009). / A soja é a principal commodity agrícola mundial, sendo os Estados Unidos, Brasil e Argentina os principais produtores. Esta tese teve como objetivos (i) avaliar o modelo SoySim na simulação do crescimento, desenvolvimento e rendimento de cultivares de soja com grupo de maturação maior que 4.2 na região subtropical do Brasil e (ii) simular a produtividade potencial e com limitação por água em soja no Estado do Rio Grande do Sul em dois cenários climáticos futuros do IPCC (SRES A1B e RCP4.5) com os modelos SoySim e CROPGRO-Soybean. Pra alcançar o primeiro objetivo, foram usados dados de experimentos de campo com 20 cultivares de soja, em 38 diferentes datas de semeadura durante os anos agrícolas de 2010/2011, 2011/2012, 2012/2013, 2013/2014 e 2014/2015, em 12 locais no Rio Grande do Sul. As cultivares de soja utilizadas possuem grupo de maturação variando entre 4.8 e 8.2 e tipo de crescimento indeterminado e semi-determinado. A avaliação do modelo SoySim mostrou razoável simulação dos estágios vegetativos e reprodutivos, número final de nós e produtividade, mas no geral, as simulações que obtiveram os menores erros foram aquelas com grupo de maturação menor que 6.0. Para o segundo objetivo, as simulações com os cenários de emissões SRES A1B e RCP4.5 forçando os modelos agrícolas SoySim e CROPGRO-Soybean mostraram um aumento na produtividade de soja no Rio Grande do Sul até o final do século XXI, com anomalia positiva de até 2 Mg ha-1 no período de 2070-2099 em relação ao período baseline (1980-2009).
12

Calibration, uncertainties and use of soybean crop simulation models for evaluating strategies to mitigate the effects of climate change in Southern Brazil / Calibração, incertezas e uso de modelos de simulação da soja para avaliar estratégias de mitigação aos efeitos das mudanças climáticas na região Centro-Sul do Brasil

Rafael Battisti 05 August 2016 (has links)
The water deficit is a major factor responsible for the soybean yield gap in Southern Brazil and tends to increase under climate change. Crop models are a tool that differ on levels of complexity and performance and can be used to evaluate strategies to manage crops, according the climate conditions. Based on that, the aims of this study were: to assess five soybean crop models and their ensemble; to evaluate the sensitivity of these models to systematic changes in climate; to assess soybean adaptive traits to water deficit for current and future climate; and to evaluate how the crop management contribute to soybean yields under current and future climates. The crop models FAO - Agroecological Zone, AQUACROP, DSSAT CSM-CROPGRO-Soybean, APSIM Soybean, and MONICA were assessed. These crop models were calibrated using experimental data obtained during 2013/2014 growing season in different sites, sowing dates and crop conditions (rainfed and irrigated). For the sensitivity analysis was considered climate changes on air temperature, [CO2], rainfall and solar radiation. For adapting traits to drought, the soybean traits manipulated only in DSSAT CSM-CROPGRO-Soybean were deeper root depth, maximum fraction of shoot dry matter diverted to root growth under water stress, early reduction of transpiration, transpiration limited as a function of vapor pressure deficit, N2 fixation drought tolerance and reduced acceleration of grain filling period in response to water deficit. The crop management options strategies evaluated were irrigation, sowing date, cultivar maturity group and planting density. The estimated yield had root mean square error (RMSE) varying between 553 kg ha-1 and 650 kg ha-1, with d indices always higher than 0.90 for all models. The best performance was obtained when an ensemble of all models was considered, reducing yield RMSE to 262 kg ha-1. The crop models had different sensitivity level for climate scenario, reduction yield with temperature increase, higher rate of reduction of yield with lower rainfall than increase of yield with higher rainfall amount, different yields response with solar radiation changes due to baseline climate and model, and an asymptotic soybean response to increase of [CO2]. Combining the climate scenarios, the yield was affected mainly by reduction of rainfall (increase of solar radiation), while temperature and [CO2] interaction showed compensation effect on yield losses and gains. The trait deeper rooting profile had greater improvement in total production for the Southern Brazil, with increase of 3.3 % and 4.0 %, respectively, for the current and future climates. For soybean management, in most cases, the models showed that no crop management strategy has a clear tendency to result in better yields in the future if shift from the best management of current climate. This way, the crop models showed different performance against observed data, where the model parametrization and structure affected the response to alternatives managements to climate change. Although these uncertainties, crop models and their ensemble are an important tool to evaluate impact of climate change and alternatives to mitigation. / O déficit hídrico é o principal fator causador de perda de produtividade para a soja no Centro-Sul do Brasil e tende a aumentar com as mudanças climáticas. Alternativas de mitigação podem ser avaliadas usando modelos de simulação de cultura, os quais diferem em nível de complexidade e desempenho. Baseado nisso, os objetivos desse estudo foram: avaliar cinco modelos de simulação para a soja e a média desses modelos; avaliar a sensibilidade dos modelos a mudança sistemática do clima; avaliar características adaptativas da soja ao déficit hídrico para o clima atual e futuro; e avaliar a resposta produtiva de manejos da soja para o clima atual e futuro. Os modelos utilizados foram FAO - Zona Agroecológica, AQUACROP, DSSAT CSM-CROPGRO-Soybean, APSIM Soybean e MONICA. Os modelos foram calibrados a partir de dados experimentais obtidos na safra 2013/2014 em diferentes locais e datas de semeadura sob condições irrigadas e de sequeiro. Na análise de sensibilidade foram modificadas a temperatura do ar, [CO2], chuva e radiação solar. Para as características de tolerância ao déficit hídrico foram manipulados, apenas no modelo DSSAT CSMCROPGRO- Soybean, a distribuição do sistema radicular, biomassa divergida para crescimento radicular sob déficit hídrico, redução antecipada da transpiração, limitação da transpiração em função do déficit de pressão de vapor, fixação de N2 sob déficit hídrico e redução da aceleração do ciclo devido ao déficit hídrico. Os manejos avaliados foram irrigação, data de semeadura, ciclo de cultivar e densidade de semeadura. A produtividade estimada obteve raiz do erro médio quadrático (REMQ) variando entre 553 kg ha-1 e 650 kg ha-1, com índice d acima de 0.90 para todos os modelos. O melhor desempenho foi obtido utilizando a média de todos os modelos, com REMQ de 262 kg ha-1. Os modelos obtiveram diferentes níveis de sensibilidade aos cenários climáticos, reduzindo a produtividade com aumento da temperatura, maior taxa de redução da produtividade com menor quantidade de chuva do que aumento de produtividade com maior quantidade de chuva, diferentes respostas com a mudança da radiação solar em função do clima local e do modelo, e resposta positiva assimptótica para o aumento da concentração de [CO2]. Quando combinado as mudanças dos cenários, a produtividade foi afetada principalmente pela redução da chuva (aumento da radiação solar), enquanto a mudança na temperatura e [CO2] mostrou compensação nas perdas e ganhos. A distribuição do sistema radicular foi o mecanismo de tolerância ao déficit hídrico com maior ganho de produtividade, representando ganho total na produção de 3,3 % e 4,0% para a região, respectivamente, para o clima atual e futuro. Para os manejos não se observou melhores resultados com a mudança do manejo para o futuro em relação a melhor condição para o clima atual. Desta forma, os modelos mostraram diferentes desempenho, em que a parametrização e a estrutura do modelo afetaram a resposta das alternativas avaliadas para mudanças climáticas. Apesar das incertezas, os modelos de cultura são uma importante ferramenta para avaliar o impacto e alternativas de mitigação as mudanças climáticas.
13

Kartläggning av Cytivas koldioxidutsläpp till följd av inomhustemperaturreglering / Mapping of Cytiva's carbon dioxide emissions as a result of indoor temperature control

Green, Oscar, Pettersson, Sixten, Stenberg, Isabell, Fält, Daniel, Sköld, Sofie, Lagerqvist, Nicklas January 2022 (has links)
This is a study conducted on behalf of the pharmaceutical company Cytiva in Uppsala via STUNS Energi by students at Uppsala university. The goal for Cytiva is to reduce their carbon dioxide footprint and the purpose of this study is to evaluate the possibilities of reducing their carbon dioxide emissions from the heating and cooling of their facilities, mainly office buildings. The office buildings used for the study are the older A-buildings and the more modern D1 building. The main issue used in formulating the method for this study was “How does Cytivas CO2-emission behave in regards to their indoor temperature regulation?” A separate issue using the results from the first mentioned issue is to provide an answer to “How does Cytivas CO2-emission behave in the future?” and with this help Cytiva plan ahead for the future. A data study was conducted and was supplemented by a literature study. The data was provided by Cytiva and their partners for temperatures in the buildings, outdoor temperatures, and their heat energy consumption. Key figures for the CO2-emission could be used to calculate the emissions from the heating and cooling of the buildings. In the end a linear behavior between the outdoor temperature difference and their heat energy consumption was proven and a linear model was created in order to predict changes in their CO2-emission from altering the indoor temperature. Also a difference between the efficiency in the buildings was proven, where the D1 building would be considered superior to the A- buildings. / Denna studie utfördes på uppdrag och efterfrågan av Cytiva via STUNS Energi av studenter på Uppsala universitet. Syftet var att analysera och kvantifiera hur regleringen av inomhustemperaturen i Cytivas kontorslokaler påverkar koldioxidemissionen. Kontorslokalerna som undersöktes är belägna i Uppsala och är två äldre hus, A1 och A2 samt ett nyare hus, D1. Huvudmålet med studien var att informera Cytiva om deras koldioxidutsläpp till följd av deras temperaturreglering inomhus. Den primära frågeställningen som besvarades med hjälp av studien är “Hur ser Cytivas koldioxidutsläpp ut från inomhustemperaturreglering?”. Ett ytterligare mål med studien var att hitta en generell modell som kan appliceras för att simulera framtidens koldioxidutsläpp. Modellen kunde vidare ge svar på studiens andra frågeställning som lyder “Hur ser Cytivas koldioxidutsläpp ut vid modellering för framtiden?”. Studien genomfördes genom datahantering, tolkning av data samt med hjälp av en förstudie. Den behandlade data bestod av utomhus-, inomhus- och tilluftstemperaturer samt energiförbrukningen för husen. Den första frågeställningen besvarades med hjälp av att ett samband togs fram mellan energiförbrukningen och skillnaden mellan utomhus- och inomhustemperaturen korrigerad med en konstant. Energiförbrukningen kunde sedan konverteras till koldioxidutsläpp med hjälp av ett nyckeltal för fjärrvärme. Till exempel var Cytivas totala koldioxidutsläpp 189 ton från fjärruppvärmningen i hus D1 under hela 2021. För A-husen användes samma metod som för D1 förutom att inomhustemperaturen ersattes av tilluftstemperaturen på grund av saknad data. A-husens koldioxidutsläpp till följd av fjärruppvärmning under hela 2021 var 158 ton. Den andra frågeställningen besvarades genom att modellen som konstruerades för den första frågeställningen användes. Studien resulterade i en skillnad mellan byggnaderna och att det finns ett tydligt samband mellan fjärrvärmeförbrukningen och utomhustemperaturen. Byggnaderna skiljer sig från varandra men ungefär samma slutsats kan dras. Eftersom utomhustemperaturen kommer öka till följd av den globala uppvärmningen kommer värmeförbrukningen minska medan kylning av lokalerna kommer öka för att uppnå en komfortabel inomhustemperatur. I framtiden kommer alltså koldioxidutsläppen från Cytivas inomhustemperaturreglering minska i jämförelse med hur det ser ut i dagsläget. Om inomhustemperaturen höjs i D1 med en grad kan utsläppen öka med upp till 16 % och en sänkning med en grad kan leda till minskade utsläpp med upp till 15 %.
14

Byggnadsutformning för ett framtida varmare klimat : Klimatscenariers påverkan på energianvändning och termisk komfort i ett flerbostadshus och alternativa byggnadsutformningar för att förbättra resultatet / Building design for a future warmer climate : Climate scenarios impact on energy demand and the thermal comfort in an apartment building and alternative constructions to improve the results

Monfors, Lisa, Morell, Corinne January 2020 (has links)
När byggnader projekteras används klimatfiler från 1981-2010 för att dimensionera konstruktionen och energisystemet. Detta leder till att byggnader dimensioneras för ett klimat som varit och inte ett framtida klimat. SMHI har tagit fram olika klimatscenarier för framtiden som beskriver möjliga utvecklingar klimatet kan ta beroende på fortsatt utsläpp av växthusgaser. Dessa scenarier kallas för RCP (Representative Concentration Pathways). I denna studie används två olika klimatscenarier, RCP4,5 och RCP8,5. Siffran i namnet står för den strålningsdriving som förväntas uppnås år 2100. I RCP4,5 kommer medelårstemperaturen öka med 3 °C fram till år 2100 jämfört med referensperioden 1961-1990.  För samma tidsperiod sker en ökning på 5 °C enligt RCP8,5.  Ett flerbostadshus certifierad enligt Miljöbyggnad 2.2 nivå silver placerat i Vallentuna i Stockholms län används i denna studie som referensbyggnad. Byggnaden simuleras i programmet IDA ICE där den utsätts för RCP4,5 och RCP8,5. Resultatet visar att byggnaden inte skulle klara av kraven för Miljöbyggnad 2.2 gällande termiskt klimat sommar i något av de två klimatscenarierna. De operativa temperaturerna blir för höga i byggnaden utan att tillsätta komfortkyla.  Byggnaden ändras för att se vilka faktorer som kan förbättra resultatet gällande det termiska klimatet. Resultatet visar att värmelagringsförmåga hos byggmaterial och solavskärmning har störst påverkan på det termiska klimatet.  I studien gjordes flertal olika kombinationer av byggnadsutformningar. Enbart kombinationen av en tung stomme av betong tillsammans med fönster med lägre g-värde klarar kraven för Miljöbyggnad 2.2 i RCP4,5 och RCP8,5 utan komfortkyla. Kombinationen får lägst energianvändning i RCP8,5 av de olika kombinationerna som testats i studien.  En kombination av tung stomme av KL-trä med lågt U-värde, fönster med lägre g-värde och komfortkyla får lägst energianvändning i grundklimatet och RCP4,5 av de olika kombinationerna som testats i studien trots användningen av komfortkyla.  Frågan om vilket alternativ som är bäst ur ett hållbarhetsperspektiv är svårt att svara på. Det finns många aspekter som behöver tas i hänsyn till som byggnadens totala klimatavtryck både i tillverkning och användning. Oavsett val av konstruktion är det viktigt att projektera för att komfortkyla och solavskärmning skall kunna appliceras när ett varmare klimat råder. / When buildings are designed climate files from 1981 to 2010 are used to construct the building and its energy system. This leads to building being designed to a climate that has been and not to a future warmer climate that will come. SMHI has developed different climate scenarios for the future that describe different paths the climate can take depending on continued emissions of greenhouse gas. This climate scenarios are called RCP (Representative Concentration Pathways) In this study two of the climate scenarios, RCP4,5 and RCP8,5 are used. The number in the name stands for the radiation forcing that is expected in the year 2100.  In RCP4,5 the mean average air temperature will increase with 3 °C until year 2100 compared to the reference period 1961-1990. In the same time period RCP8,5 will increase with 5 °C.  An apartment building certified according to Miljöbyggnad 2.2 level silver placed in Vallentuna, Stockholms län is used as a reference building. The building is simulated through the simulation software program IDA ICE where it´s exposed to RCP4,5 and RCP8,5. The results demonstrate that the reference building would not meet Miljöbyggnad 2.2 requirement in the indicator about thermal comfort during summer. The operative temperature in the building is too high unless comfort cooling is used.  The design of the building changes to see what factors can improve the results regarding the thermal comfort. The results demonstrate that thermal conductivity and solar shading has the greatest impact on thermal comfort.  In this study several combinations of different building designs were made. Only the combination of a concrete frame with windows with low g-value met the requirement of Miljöbyggnad 2.2 regarding the thermal comfort during summer without using comfort cooling in RCP4,5 and RCP8,5. The combination had the lowest energy demand in RCP8,5 of all the combinations tested in the study.  A combination of cross laminated wood frame with low U-value, windows with low g-value and comfort cooling had the lowest energy demand in the original climate file and RCP4,5 despite the use of comfort cooling.  The questing about which building construction is the best from a sustainable perspective is difficult to answer. To answer that question the building´s total climate footprint in both production and use must be calculated. Regardless of the choice of building construction it is important to have in mind when designing a building that comfort cooling and solar shading should be easily applied when a warmer climate will prevail.

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