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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.
21

Vliv fázové přeměny vody v zemině na průběh teplotního kmitu / Effect of soil water phase change on the soil temperature oscillation

Trlica, Ondřej January 2017 (has links)
This thesis deals with the study of soils freezing in terms of phase change of water contained in the soil strata on green roofs. The aim of this work is to verify the effect of phase transformation of water on the course of temperature oscillation. First described the basic characteristics of soils generally, and subsequently described processes occurring during phase transformation of water in the soil and has been carried out experimental verification of the effect of moisture in the soil on the course of temperature oscillation. In the overall evaluation of the work, an analysis of the effect of phase change water in soil on the course of temperature oscillation and the resulting conclusion of work.
22

Hur påverkar en värmebölja det termiska inomhusklimatet i ett tidstypiskt flerbostadshus från 1950-talet, och hur kan grön infrastruktur inverka på det?

Frykman, Wilma January 2022 (has links)
Världen idag står inför klimatförändringar och värmeböljor förväntas bli allt vanligare, långvarigare och intensivare. Byggnader är framför allt utformade för att bevara värme under kallare perioder och de flesta byggnader saknar möjlighet till aktiv kylning. Byggnader som klarar dagens energikrav behöver både vädring och solskydd för att inte uppnå hälsofarliga temperaturer under en värmebölja.  Under värmeböljor drabbas byggnader och människor i tätorter hårdare av värme än de ute på landsbygden eftersom värmen lagras i byggnader och solinstrålningen blir mer intensiv. Att utsättas för höga temperaturerna har en negativ effekt på människors hälsa och kan i värsta fall leda till dödlighet. Samtidigt ökar befolkningen inom tätorter och fler bostäder behöver byggas. Ökad bebyggelse kan leda till fler hårdytor och mindre grönska vilket i sin tur kan leda till ännu högre temperaturer i tätorter. Grön infrastruktur i tätorter kan bidra till temperatursänkning och är ett sätt att minska på konsekvenser från värmeböljor. Eftersom byggnader som klarar dagens energikrav behöver hjälpmedel för att inte uppnå höga inomhustemperaturer är det intressant att undersöka hur ett äldre flerbostadshus påverkas under samma omständigheter.  Syftet med studien är att bidra till ökad kunskap om hur det termiska inomhusklimatet i en äldre byggnad kan påverkas av en värmebölja, och hur grön infrastruktur på och runt byggnaden kan påverka det. Målet med studien är att besvara följande forskningsfrågor.  •       Hur kan en värmebölja påverka det termiska inomhusklimatet i ett tidstypiskt flerbostadshus från 1950-talet? •       Hur kan grön infrastruktur påverka det termiska inomhusklimatet i byggnaden?   Studien är en simuleringsstudie där datorprogrammet IDA ICE har använts för att skapa en modell av ett tidstypiskt flerbostadshus byggd på 50-talet. Simuleringar utfördes för att se hur inomhustemperaturen påverkas av en värmebölja. Den klimatdata som använts är från år 2018 i Göteborg där en värmebölja inträffade med utomhustemperaturer upp emot 35°C. Simuleringar för ett antal olika scenarion genomfördes för att undersöka om det var värmeböljan som påverkade det termiska inomhusklimatet eller om det var andra faktorer såsom, installationer eller brukarbeteenden. Grön infrastruktur i form av träd adderades sedan till scenarierna och simulerade inomhustemperaturer för scenarier med och utan träd jämfördes. Studiens resultat visade att värmeböljor bidrar till höga temperaturer i ett tidstypiskt flerbostadshus från 50-talet trots hjälpmedel som vädring. Den operativa inomhustemperaturen översteg Folkhälsmyndighetens rekommendationer vilket betyder att andra hjälpmedel måste installeras för att byggnaden inte ska uppnå höga temperaturer. Grön infrastruktur i form av tätare träd kunde sänka inomhustemperaturen med 3°C. Tätare träd sänkte inomhustemperaturen som max 2°C mer än glesare träd. Det visar att olika typer av gröna infrastruktur ger olika resultatet på inomhustemperaturen.  Studiens resultat pekar på behovet av att i fortsatta studier undersöka fler typer av grön infrastruktur, använda andra datorprogram eller undersöka andra parametrar som kan påverka inomhusklimatet. / The world is facing climate change and heat waves are expected to become more common, longer lasting and more intense. Buildings are primarily designed to retain heat during colder periods and most buildings do not have the option of active cooling. Buildings that meet today's energy requirements need both ventilation and sun protection in order to not reach unhealthy temperatures during a heat wave. Buildings and people in urban areas are hit harder by heat than those in rural areas during a heat wave because the heat is stored in buildings and the solar radiation becomes more intense. Exposure to high temperatures has a negative effect on human health and can, in worst case, lead to mortality. The population in urban areas are increasing and more homes need to be built. Increased buildings can lead to more hard surfaces and less greenery, which in turn can lead to even higher temperatures in urban areas. Green infrastructure in urban areas can contribute to lowering the temperature and is a way of reducing the consequences of heat waves. Since buildings that meet today's energy requirements need aid to not achieve high indoor temperatures, it is interesting to investigate how an older apartment building is affected under the same circumstances. The purpose of the study is to contribute to increased knowledge about how the thermal indoor climate in an older building can be affected by a heat wave, and how green infrastructure on and around the building can affect it. The aim of the study is to answer the following research questions. ·      How can a heat wave affect the thermal indoor climate in a typical apartment building from the 1950s? ·      How can green infrastructure affect the indoor thermal climate in the building? The study is a simulation study where the computer program IDA ICE has been used to create a model of a typical apartment building built in the 50s. Simulations were performed to see how the indoor temperature is affected by a heat wave. The climate data used is from 2018 in Gothenburg, where a heat wave occurred with outdoor temperatures up to 35 degrees. Simulations for several different scenarios were performed to investigate whether it was the heat wave that affected the thermal indoor climate or whether it was other factors such as, installations or user behaviors. Green infrastructure in the form of trees were then added to the scenarios and the simulated indoor temperatures for the scenarios with and without trees were compared. The results of the study showed that heat waves contribute to very high temperatures in a standard apartment building from the 50s, despite aids such as ventilation. The operating indoor temperature exceeded the Swedish Public Health Agency's recommendations, which means that other aids must be installed for the building to not reach high temperatures. Green infrastructure in the form of denser trees could lower the indoor temperature with 3°C. Denser trees lowered the indoor temperature by a maximum of 2°C more than sparser trees. It shows that different types of green infrastructure give different results on the indoor temperature. The results of the study show that further studies can investigate more types of green infrastructure, using other computer programs or investigating other parameters that can affect the indoor climate.
23

Spatio-temporal Analysis of Urban Heat Island and Heat Wave Evolution using Time-series Remote Sensing Images: Method and Applications

Yang, Bo 11 June 2019 (has links)
No description available.
24

Spatial distribution and thermo-climatic effects on the abundance of non-toxigenic Vibrio cholerae in Russia

Leonov, Vadim January 2023 (has links)
The identification of climate temperature-sensitive pathogens and infectious diseases is essential in addressing health risks resulting from global warming. Such research is especially crucial in regions where climate change may have a more significant impact like Russia. Recent studies have reasoned that the abundance of V. cholerae tox- is environmentally driven. The aim of the degree project is to investigate the spatial-temporal trends and thermo-climatic sensitivity of non-toxigenic V. cholerae abundance in Russia. This study employed spatial epidemiology tools to identify persistent clusters of the V. cholerae tox- isolation and areas for exploring temperature-depended patterns of the vibrio distribution. Correlation analysis was used to identify regions with temperature-driven Vibrio abundance – vibrioses and the V. cholerae tox- prevalence in water samples. GAM was applied to evaluate the relationship between V. cholerae tox- prevalence and the mean summer air temperature. The spatial analysis detected 16 persistent (7-8 year) clusters of V. cholerae tox- across the study period 2005-2021. The highest-risk areas are located between 54.70 and 55.15 latitudes. The persistent clusters should become targeted areas to improve sanitation conditions. A distinct significant thermo-climatic effect on the abundance of V. cholerae tox- in water basins was found in three Russian regions with temperate marine (the Kaliningrad region - Dwb) and sharp continental climatic conditions (the Irkutsk region - Dwb and the Republic of Sakha - Dwd). Finally, our results showed significant relationships between ambient summer temperature and vibriosis caused by V. cholerae tox- in the Rostov and Volgograd regions. Heat waves for both regions facilitated the eruption of reported vibriosis in 2007 and 2010. The study offers valuable outcomes to support simplified empirical evaluations of the potential hazards of vibrio abundance that might be useful locally for public health authorities and globally as a part of the warning system of climate change effects in Russia.
25

Physiological responses of Ulva fasciata Delile (Ulvales, Chlorophyta): comparison of two populations from thermally distinct sites from Brazilian coast / Respostas fisiológicas de Ulva fasciata Delile (Ulvales, Chlorophyta): comparação de duas populações de locais termicamente distintos do litoral brasileiro

Martins, Nuno Tavares 10 January 2017 (has links)
In a global warming scenario, an increase temperature is expected in addition to the occurrence and intensity of extreme climate events. One example of extreme events is the marine heat waves, which are a major threat to marine macroalgae. Ulva fasciata is a cosmopolitan species that occur in the whole Brazilian coast. This study was performed in two regions of Rio de Janeiro State (RJ) coast. Both regions are tropical, however, Arraial do Cabo/RJ is naturally colder than Niterói/RJ due upwelling phenomenon. This study aimed to: (i) confirm that U. fasciata individuals from these two Brazilian coast regions are of the same species; and (ii), physiologically analyze individuals of U. fasciata in the field and under in-laboratory controlled temperature experiment. We hypothesized that U. fasciata populations grown at thermally different locations would present distinct ecophysiological responses. In the field, it was accessed maximum quantum yield (Fv/Fm) and pigment content, and in laboratory, it was also evaluated growth rate. The in-laboratory controlled experiment comprised three phases: (i) a temperature gradient; (ii) a 5-day heat wave (+ 5 oC); and (iii) a 5-day recovery (- 5 oC). The molecular data allow us to state that the two populations belong to the same species. No differences of the fluorescence-derived factors were observed between individuals from both populations in the field, suggesting acclimation. However, differences were detected along all three experimental phases. The analysis of pigment content field data evidenced that individuals from the population of Niterói (warmer site) had higher concentrations of chlorophyll a than individuals from Arraial do Cabo (colder site). However, individuals of population from Niterói when cultured at 21 oC showed the lowest values of pigment. The differences observed suggest ecotypes. In conclusion, as the planet becomes warmer and extreme weather events become more frequent, the likelihood that heat wave to occur is higher. Therefore, U. fasciata from Arraial do Cabo showed better physiological responses to the effects of heat wave, what could confer them higher competitiveness ability to overcome thermal stress / Num cenário de aquecimento global, um aumento da temperatura é esperado, assim como a ocorrência e intensidade de eventos climáticos extremos. Um exemplo de evento extremo são as ondas de calor marinhas, que são a principal ameaça a macroalgas marinhas. Ulva fasciata é uma espécie cosmopolita que ocorre em toda costa brasileira. Esse estudo foi realizado em duas regiões da costa do Estado do Rio de Janeiro (RJ). Ambas regiões são tropicais, mas Arraial do Cabo/RJ é naturalmente mais fria que Niterói/RJ devido ao fenômeno de ressurgência. Esse estudo objetivou: (i), confirmar que os indivíduos de U. fasciata dessas duas localidades da costa brasileira são da mesma espécie; e (ii) analisar fisiologicamente indivíduos de U. fasciata em campo e em experimentos de temperatura em condições controladas de laboratório. Nossa hipótese era de que populações de U. fasciata procedentes de localidades termicamente diferentes iriam apresentar respostas ecofisiológicas distintas. Em campo, foi acessado o rendimento quântico máximo (Fv/Fm) e o conteúdo pigmentar, e em laboratório, foi também avaliada a taxa de crescimento. O experimento em condições controladas de laboratório consistiu de três fases: (i) gradiente de temperatura; (ii) onda de calor (+5 oC) de 5 dias; e (iii) recuperação (- 4 oC) de 5 dias. Os dados moleculares permitiram afirmar que as duas populações pertencem à mesma espécie. Não foram detectadas diferenças nos fatores derivados da fluorescência entre os indivíduos das duas populações avaliadas em campo, sugerindo aclimatação. Contudo, foram detectadas diferenças ao longo das três fases experimentais. A análise do conteúdo pigmentar em campo evidenciou que os indivíduos da população de Niterói (região mais quente) tinham mais clorofila a do que os indivíduos de Arraial do Cabo (região mais fria). No entanto, indivíduos da população de Niterói, quando cultivados em 21 oC, mostraram valores menores de pigmentos. As diferenças observadas sugerem ecótipos. Em conclusão, conforme o planeta se torna mais quente e eventos extremos climáticos se tornam mais frequentes, a probabilidade de ocorrência de ondas de calor é maior. Dessa forma, U. fasciata de Arraial do Cabo mostro melhor resposta fisiológica aos efeitos da onda de calor, o que lhe pode conferir maior capacidade de competição para superar estresses térmicos
26

Caracterização e previsão de ondas de calor com impacto na mortalidade de frangos de corte / Characterization and estimation of occurrence of heat waves with impact on broiler mortality

Vale, Marcos Martinez do 23 April 2008 (has links)
Orientador: Daniella Jorge de Moura / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-10T15:17:54Z (GMT). No. of bitstreams: 1 Vale_MarcosMartinezdo_D.pdf: 4930085 bytes, checksum: c13a4400cf22926da65e99857857d0ba (MD5) Previous issue date: 2008 / Resumo: Com o aumento da produção de frangos de corte no Brasil surge a necessidade de otimização do sistema de produção, principalmente devido a um mercado competitivo, sendo necessária a aplicação de recursos de tecnologia que reduzam perdas. Perdas produtivas decorrentes de ondas de calor (OC) são comuns na produção de frangos de corte em clima tropical e a solução é um problema complexo. A previsão precoce destes eventos climáticos com impacto na mortalidade permite reduzir perdas. Bancos de dados zootécnicos e meteorológicos podem conter padrões úteis para a previsão da mortalidade de frangos de corte, possíveis de se extrair por técnicas como a Mineração de Dados. Este trabalho teve por objetivo geral predizer a mortalidade de frangos de corte com um mínimo de 24 horas de antecedência. Os objetivos específicos foram: 1) Caracterizar OC com impacto sobre a mortalidade de frangos de corte; 2) Gerar modelos de previsão aplicável a sistemas de suporte à decisão durante o processo produtivo de frangos de corte prevendo a ocorrência de mortalidade alta em frangos de corte devido a OC; 3) Indicar ações mitigadoras para a amenização do impacto de OC. As OC com impacto na mortalidade de frangos de corte apresentaram características que dependem do tipo construtivo e da idade da ave. A condição mínima para a ocorrência de OC afetando aviários sem climatização foi: temperatura máxima do dia > 32º C; temperatura média do dia > 24º C; Índice de Temperatura e Umidade (ITU) médio > 23º C; Velocidade média do vento _ 1,4 m s-1. Para aviários com climatização mínima, a mortalidade ocorreu de forma diferente entre as idades, não havendo mortalidade por OC para idade até 31 dias. Para as demais idades as condições para o desencadeamento de mortalidade alta foram: entre 31 e 40 dias: ITU máximo > 30,6º C e temperatura máxima > 34,4º C; entre 41 dias e o abate: ITU máximo > 30,6º C; temperatura máxima > 34,4º C; ITU mínimo _ 15,5º C; hora da temperatura máxima > 15h00min. A magnitude média de OC com impacto na mortalidade de frangos de corte, medida em ITU horas grau acumulado (ITUhga) > 24º C, foi de 367º C acumulados no dia. As previsões com 48 horas (precisão de 91,12% do modelo e 66,9% para a mortalidade alta) e 24 horas (precisão de 97,2% do modelo e 93,3% para a mortalidade alta) de antecedência permitem o desencadeamento de ações mitigadoras para a redução da mortalidade em frangos de corte. Dias de OC apresentam uma pior condição térmica, uma menor umidade relativa do ar nos horários de pico de calor, no turno da tarde, o que permite estratégias de mitigação com a intensificação do uso dos ventiladores e resfriamento evaporativo iniciando operação entre 09h00min e 10h00min, perdurando até as 20h00min. A previsão da mortalidade alta em frangos de corte a partir de dados meteorológicos com 24 e 48 horas de antecedência pode auxiliar na tomada de decisão precoce para se evitar esta mortalidade / Abstract: As broiler production increases in Brazil it appears the need of optimizing production system mainly due to the market competitiveness, and technological resources application are required for reducing losses. Productive loss decurrently from heat wave (HW) incidence is quite common in broiler rearing under tropical conditions, and the solution for this is a rather complex problem. The early forecast of these climate events with impact on animal mortality may allow losses reduction. Data base on animal production and meteorology may enclose useful pattern for broiler mortality prediction, and it can be possible to extract them by techniques such as Data Mining. This research had the general objective of predicting broiler chicken mortality with a minimum period of 24 hours prior to heat wave exposure. The specific objectives were: 1) To characterize HW with impact on broiler mortality; 2) To generate forecast models applied to decision making systems during the broiler productive process, estimating the high mortality occurrence due to HW exposure; 3) To indicate mitigation actions to reduce HW impact on broiler chicken production. The HW with impact on broiler mortality presented characteristics that depend on the housing characteristics as well as on the age of the bird. The minimum concomitant climatic condition for HW affecting broiler production reared on housing without acclimatization was: maximum daily environmental temperature > 32º C; average daily temperatures > 24º C; average temperature and humidity index (THI) > 23º C; and average wind speed _ 1.4 m s-1. For housing with the minimum acclimatization equipments mortality occurred in a distinct way for birds with distinct ages, and there was not mortality by HW exposure for birds up to 31 days old. For birds with age different from that, the climate condition for starting the high mortality incidence was distinct such as: between 31 and 40 days old: Maximum THI > 30.6 ºC and maximum environmental temperature above 34.4 ºC; between 41 days old and laughter age: maximum THI > 30.6 ºC; maximum ambient temperature > 34.4º C; minimum THI _ 15.5 ºC; time that the maximum ambient temperature was found > 15h00min. The mean HW magnitude with impact in broiler 31 days old and characterized by THI degrees hour accumulated (THIdha) >24ºC, was of 367 ºC accumulated during the day. The forecast within 48 hours (91.12% accuracy and 0.66 precision for the class High Mortality) and 24 hours (97.2% accuracy of the model, and 0.93 precision for the class High Mortality) of minimum forecast allows the start of mitigation actions for reducing broiler mortality. Days during HW present the worst thermal conditions, with lower air relative humidity during peak of heat during the afternoon; that allows the adoption of mitigation strategies by using fans and evaporative cooling starting between 09h00min and 10h00min up to 20h00min. It was possible to predict high broiler mortality using meteorological data forecast within 24 and 48 hours, and this may help early decision making to avoid economical losses / Doutorado / Construções Rurais e Ambiencia / Doutor em Engenharia Agrícola
27

Heat waves in South Africa: Observed variabilty, structure and trends

Mbokodo, Innocent Lifa 18 May 2017 (has links)
MENVSC (Climatology) / Department of Geography and Geo-Information Sciences / Heat waves are warm extreme temperature events that have environmental and socio-economic impacts in many regions across the world. Negative impacts of warm extreme temperatures over South Africa necessitate the need to study the nature of heat waves. Observations and satellite datasets are analysed in the investigation of the nature and trends of heat waves over South Africa in the present (1983-2012) and future (2010-2039, 2040-2069, 2070-2099) climates. Case study and composite analysis of National Centers for Environmental Prediction datasets were done using the Grids Analysis and Display Systems to get an in-depth understanding of the structure of heat waves in South Africa. Future climate model output obtained from the Conformal Cubic Atmospheric Model was used for future heat wave trends in South Africa. The simulations were made using the Representative Concentration Pathways 4.5 and 8.5. Heat waves are unusual events in the present climate (1983-2012) over much of the country, with 20 of the selected 24 stations experiencing an average of less than one heat wave per season. Heat waves are also more frequent and last longer during warm phase of El Niño-Southern Oscillation (ENSO) than in cool phase of ENSO with the north-east being the most prone region. Composite analysis of 500 hPa omega indicates subsidence over the interior of South Africa in both phases of ENSO. Heat waves in South Africa are localized and associated with a middle level high pressure system that persists over the interior inducing anticyclonic flow and subsidence. The anticyclonic circulation over a region experiencing heat wave weakens with decreasing height over land areas which may be due to frictional forces at the surface and the high is placed further south-east at the surface. Advection of dry continental northerly winds also contributes to high maximum temperatures during heat waves in the interior. Maximum temperatures are expected to increase drastically from the present-day climate to the 2070 – 2099 period, with an average increment of about 8°C during DJF in much of the central interior. As a result, heat wave occurrences are expected to be higher in the future warmer climates when climate change signal is higher. Most increases are expected for heat waves lasting for a week than those lasting for over 2 weeks. CCAM outputs also indicated that heat waves in South Africa are expected to last longer and become more intense during the future warmer climates. Longer lasting and more intense heat waves are expected over the Karoo than in other parts of the country.
28

Adapting into Heatwave: Through Child-Parents Collaborative Prevention

Jiang, Yuanxi January 2024 (has links)
Children are vulnerable to the heatwaves, so to protect children from heat-related illness, taking preventative action during summer is necessary. To offer insights for the future design that supports child-parent collaborative prevention during heatwaves and promotes children’s independence, this project increases understanding of: Firstly, current practice of how children and their caregivers are involved in prevention. Secondly, identify challenges they face during the collaborative care process and strategies to develop children’s independence in self-care. This project conducted qualitative research to explore prevention experience from the caregivers’ aspect. Through analyzing data, this study identifies firstly cognitive ability and motivation as core factors in engaging children in collaborative care and prevention. Secondly, to develop preventive ability, children can promote care skills in family-based collaborative activities. Thirdly, to support children’s independence, smoothing the role transition of caregivers in child-parent collaboration is significant. This study offers design suggestions and discusses the opportunities for applying technology to contribute to children’s prevention and maintain care consistency.
29

Effects of an Early Season Heat Wave on Ecophysiological Parameters Related to Productivity in Sugar Maple (Acer saccharum Marsh.)

Filewod, Benjamin A. 07 December 2011 (has links)
Anticipated increases in the frequency, duration or intensity of high temperature events ('heat waves') have the potential to significantly impact forest form and functioning, but these events remain virtually unstudied in forest ecosystems. This thesis presents the results of an event-driven research effort into the impacts of three days of record-setting high temperatures in late May 2010 on key ecophysiological parameters in Sugar Maple (Acer saccharum. Marsh). High temperatures reduced photosynthetic capacity by ~66% versus previous years and total end-of-season leaf litter production by ~33% versus prior measurements. It is predicted that these reductions substantially reduced productivity for Sugar Maple in 2010. These results constitute the first description of the impacts of a short-duration heat wave on productivity-related parameters in a temperate forest tree. The predicted increase in high temperature events could make such impacts a significant, though so far overlooked, pathway of climate change impacts on temperate forests.
30

Effects of an Early Season Heat Wave on Ecophysiological Parameters Related to Productivity in Sugar Maple (Acer saccharum Marsh.)

Filewod, Benjamin A. 07 December 2011 (has links)
Anticipated increases in the frequency, duration or intensity of high temperature events ('heat waves') have the potential to significantly impact forest form and functioning, but these events remain virtually unstudied in forest ecosystems. This thesis presents the results of an event-driven research effort into the impacts of three days of record-setting high temperatures in late May 2010 on key ecophysiological parameters in Sugar Maple (Acer saccharum. Marsh). High temperatures reduced photosynthetic capacity by ~66% versus previous years and total end-of-season leaf litter production by ~33% versus prior measurements. It is predicted that these reductions substantially reduced productivity for Sugar Maple in 2010. These results constitute the first description of the impacts of a short-duration heat wave on productivity-related parameters in a temperate forest tree. The predicted increase in high temperature events could make such impacts a significant, though so far overlooked, pathway of climate change impacts on temperate forests.

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