• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 101
  • 92
  • 55
  • 20
  • 12
  • 9
  • 4
  • 3
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 395
  • 43
  • 40
  • 38
  • 36
  • 33
  • 32
  • 29
  • 27
  • 26
  • 26
  • 24
  • 23
  • 22
  • 21
  • 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.
61

The cost-benefit analysis of extending the grazing season in beef cattle production in Atlantic Canada

Téno, Gabriel January 2016 (has links)
The aim of the study was to integrate economics, forage agronomy and livestock production data to determine the economic costs and benefits of management techniques that can extend the grazing season for beef production in Atlantic Canada. The results of the study show that extending the grazing season is financially and economically beneficial for both an Atlantic beef farmer and the whole Atlantic community. Extending the grazing season could be thus an alternative solution to enhance beef farm viability in Atlantic Canada. It can also contribute to the sustainable development of beef cattle production through its benefits for environmental protection. The results of this study reflect the necessity of supporting and promoting the adoption of extended grazing season practices in Atlantic beef production. This support and this promotion could involve increasing awareness, training on grazing management skills, diffusion at workshops and participatory research.
62

Bicycle Season

Hughes, Kevin Thomas 05 August 2010 (has links)
In this paper I will thoroughly analyze the thesis film, Bicycle Season, as it relates to specific areas of film production. The goal is to determine the effectiveness of specific approaches to narrative filmmaking, when the intention of the narrative to portray believable human behavior in moments of dramatic conflict. I will discuss this thesis from the point of conception on a screenwriting level; analyze the steps along the way as they relate to film production, and conclude at the point of final screening to an audience. Direct feedback from audience members in test screenings will serve as a measurement of achievement of said goals for the narrative.
63

Reator anaeróbio alimentado com vinhaça de cana-de-açúcar: avaliação dos efeitos causados pela interrupção na alimentação e estratégias para mitigação / Anaerobic reactor fed with sugarcane vinasse: evaluation of the effects caused by interruption in feeding and strategies for mitigation

Barbosa, Moara Yuri Utino 04 August 2017 (has links)
O tratamento biológico anaeróbio aparece como uma opção importante para remover a carga orgânica poluidora da vinhaça, e vem despertando interesse entre pesquisadores do mundo todo devido aos sucessos já alcançados, principalmente em trabalhos científicos. O interesse científico aponta para o aprimoramento do processo de degradação desse efluente em taxas elevadas, além de promover a produção de biogás, com potencial para produção de energia. A tecnologia de tratamento anaeróbio mais utilizada para o tratamento da vinhaça é o reator UASB, apresentando resultados satisfatórios inclusive em unidades em escala plena. A interrupção do funcionamento do reator em períodos de entressafra é, indubitavelmente, um problema a ser enfrentado na operação do reator UASB, cujo período de partida é lento. A repartida do sistema é agravada nos reatores de alta taxa, requerendo estratégias adequadas para reduzir o período necessário permitindo mitigar prontamente os efeitos do aporte de vinhaça ao ambiente e recuperar energia a partir dessa matriz. Diante disso, um reator anaeróbio de fluxo ascendente com manta de lodo (UASB) em escala piloto foi utilizado para o estudo da repartida do sistema e do tratamento da vinhaça e do melaço, sendo o último utilizado como fonte de carbono no período relativo à entressafra. O reator UASB foi operado durante 335 dias. Na Fase I utilizou-se a vinhaça como afluente, na Fase II o melaço de cana-de-açúcar e na Fase III novamente a vinhaça. Após período de interrupção de 30 dias, o período de repartida do sistema em estudo foi de 69 dias. Logo no início da repartida do reator, a eficiência de remoção de DQO foi superior a 80%, alcançando eficiência de 89,95 % em apenas oito dias de operação. O reator UASB apresentou valor médio de eficiência de remoção de DQO para as Fases I (vinhaça), II (melaço) e III (vinhaça) de 84 ± 3,35%; 82 ± 5,12% e 80 ± 9,22%, para cargas aplicadas de 5 a 34 kgDQO.m-3.d-1, 33 kgDQO.m-3.d-1 e 5 a 19 kgDQO.m-3.d-1, respectivamente. Em relação à produção de metano, de todo o período operacional, a Fase I referente à repartida do reator utilizando vinhaça como substrato após um mês sem alimentação foi a que apresentou a maior produção média no período, 7,93 LCH4. (L.d) -1, devido aos maiores valores de carga orgânica volumétrica (COV) aplicadas (5 a 34 kgDQO.m-3.d-1). A Fase II referente ao período de entressafra utilizando o melaço, foi de 7,28 LCH4. (L.d) -1 devido ao acúmulo de ácidos voláteis totais. A Fase III com retorno da safra utilizando a vinhaça, foi de 1,23 LCH4. (L.d) -1 devido aos menores valores de carga aplicada ao reator (5 a 8,5 kgDQO.m-3.d-1). As análises microbiológicas mostraram elevada diversidade microbiana e permitiu observar que com a utilização do melaço ocorreu alteração da população de microrganismos presente no reator, que apresentaram longo período de adaptação quando submetidos novamente à vinhaça, na última fase de operação. De forma geral, os resultados apontam que a tecnologia UASB é adequada no tratamento de vinhaça e melaço de alta carga orgânica e na geração de biogás. A substituição por melaço permitiu obter produção de biogás semelhante ao uso da vinhaça, entretanto dificultou a repartida, quando substituído pela vinhaça novamente (Fase III). / Biological anaerobic treatment systems are a promising approach for the removal of organic loading content of vinasse. Previous studies have demonstrated the optimization of the vinasse degradation process at high rates, promoting the biogas production with potential for energy use. Upflow anaerobic with sludge blanket (UASB) is the most applied anaerobic technology for the treatment of vinasse. Such reactor configuration presents satisfactory results even in full-scale units. The interruption of reactor operation during the off-season is undoubtedly an operational problem to be faced, whose restarting period is slow. The system restarting is intensified in high-rate reactors, requiring adequate strategies to reduce the time needed to mitigate the environmental effects of vinasse supply and to recover energy from that matrix. Therefore, a pilot-scale UASB was used to investigate the system restart and the treatment of vinasse and molasses. Sugarcane molasses was used as the carbon source during the off-season period. The system was operated during 335 days. The operational procedure consisted of three phases, in which different streams were used as carbon source: vinasse (Phases I), sugarcane molasses (Phases II) and vinasse (Phases III). After an interruption period of 30 days, the restarting period was 69 days. At the beginning of the restarting period, the average COD removal efficiency was higher than 80%, reaching COD removal efficiencies of 89.95% in only eight days of operation. The average COD removal efficiencies for Phases I (vinasse), II (molasses) and III (vinasse) were 84 ± 3.35%; 82 ± 5,12% and 80 ± 9,22%, respectively. Those removal efficiencies were achieved with organic loading rate 5 to 34 kgCOD.m-3.d-1 , 33 kgCOD.m-3.d-1 and 5 to 19 kgCOD.m-3.d-1, respectively. Regarding methane (CH4) production, Phase I (vinasse as substrate after one month without feeding) presented the highest average CH4 production (7.93 LCH4. (L.d) -1), due to the higher values of OLR (5 to 34 kgCOD.m-3.d-1). The CH4 production during Phase II (off-season using molasses as substrate) was 7.28 LCH4. (L.d) -1, due to the accumulation of volatile fatty acids (VFA). In Phase III, in which vinasse was applied again as substrate the CH4 production was 1.23 LCH4.(L.d)-1, due to the lower values of organic loading rate to the reactor (5 to 8.5 kgCOD.m-3.d-1). Microbiological analyses showed high microbial diversity in biomass developed at UASB reactor. Moreover, it was possible to observe that with molasses used as carbon source probably promotes changes in the microorganisms population, After period with molasses feeding, such microbiota presented a long adaptation period when resubmitted to vinasse, as the main carbon source in the feeding. In general, the results indicate that the UASB configuration was adequate for the vinasse and molasses treatment at high organic loading rate, resulting in high biogas production. In which the feeding with sugarcane molasses resulted in a biogas production similar to that obtained by vinasse feeding, but it made it difficult to divide when replaced by vinasse (Phase III).
64

Positividade para o vírus da raiva em morcegos no Estado de São Paulo e potenciais fatores de risco /

Favaro, Ana Beatriz Botto de Barros da Cruz. January 2018 (has links)
Orientador: Luzia Helena Queiroz / Coorientador: Márcia Marinho / Banca: Cáris Maroni Nunes / Banca: Rafael Silva Cipriano / Resumo: A raiva é uma antropozoonose caracterizada por uma encefalomielite aguda, na grande maioria dos casos letal, com grandes impactos na saúde pública, economia e na medicina veterinária. No Brasil o número de casos de raiva transmitido por morcegos vem superando a transmissão por cães, representando um novo cenário epidemiológico desta zoonose. Objetivamos analisar o índice de positividade da raiva em morcegos, segundo as variáveis hábito alimentar, classificação taxonômica, sexo e estação do ano com o intuito de identificar possíveis fatores de risco para ocorrência da raiva em morcegos. Por meio da análise retrospectiva de registros de 10.362 amostras de mamíferos dos Laboratórios de Diagnóstico de Raiva e de Chiroptera da Unesp de Araçatuba, do período de 1998 a 2017, foram identificadas 6.389 amostras provenientes de quirópteros que foram submetidos ao diagnóstico de raiva e à identificação taxonômica. Obtivemos resultado positivo em 76 (1,1%) das amostras de quirópteros, provenientes de 10 espécies, dentre as 31 que foram enviadas, representando sete gêneros de três famílias. O perfil dos morcegos positivos para a raiva na região estudada foi caracterizado como insetívoros e frugívoros, pertencentes à família Vespertilionidae e gênero Myotis e Eptesicus. A época do ano com maior identificação do vírus da raiva em quirópteros foi a estação mais seca (entre os meses de maio a setembro). / Abstract: Rabies is an anthropozoonosis characterized by acute encephalomyelitis, which is lethal in the vast majority of the cases and has major impacts on public health, economy and veterinary medicine. In Brazil, the number of rabies cases transmitted by bats has been surpassing the transmission by dogs, representing a new epidemiological scenario for this zoonosis. The objective of this study was to analyze the positivity rate of rabies in bats, according to the variables alimentary habits, taxonomic classification, sex and season of the year, in order to identify possible risk factors for rabies occurrence in bats. A retrospective analysis of the records from Rabies and Chiroptera Diagnostic Laboratories of Araçatuba, from 1998 to 2017, identified 6,389 samples from Chiroptera that were submitted to rabies diagnosis and taxonomic identification. We observed positive result in 76 (1.1%) of the bats samples, from 10 species, out of the 31 that were sent, representing seven genera of three families. Thus, the profile of positive bats for rabies in the studied region was characterized as insectivorous and frugivorous, belonging to the family Vespertilionidae, and genus Myotis and Eptesicus. The time of year with the highest identification of the rabies virus in bats was during the dry seeson (between May and September). / Mestre
65

Lactation Curves of Holstein Cows as Influenced by Age, Gestation, and Season of Freshening

Patterson, George Edward 01 May 1955 (has links)
Lactation curves of dairy cows have been studied by dairy scientists for many years. The effects of various hereditary end non-hereditary influences on the lactation curve have been observed. Factors have been developed to standardize production to a common basis, correcting for differences in age, length of lactation, milking per day, gestation and environment.
66

The Effects of Hunting Season Length on Comparable Pheasant Populations

Reynolds, Temple A. 01 May 1957 (has links)
For many years sportsmen have speculated that hunting limits pheasant populations. With the abolition of the Pheasant Game Farm program in Utah in 1953, this popular concept gained much impetus with the result that, because of public disfavor to a longer season, a 3 to 5 day season on pheasants is the maximum that bas been called in northern Utah and this only in areas classed as "better" pheasant habitat. In contrast to the short seasons in Utah, pheasant seasons in southern Idaho have been from 8½ to 15½ days long for the past 10 years, and will be even longer in 1956 (table 1). Since the topography and land-use patterns of southeast Idaho and northeast Utah are similar, the question has been asked by Cache County sportsmen, "how can Idaho maintain a 15½ day season in Franklin County, while just across the line here in Cache County, we have only a 3 to 5 day season?" Thus the purpose of this study was to investigate some of the factors affecting pheasant populations of northeast Utah and south-east Idaho under differing season lengths. Objectives of the study were to determine (1) the response of contiguous pheasant populations to long (15½ day) and short (5 day) seasons, (2) the hunting pressure under the 2 season lengths, (3) harvest of the pheasant crop under the 2 season lengths, and (4) reaction of hunters, farmers, and land-owners to long and short seasons.
67

Season of birth in suicidology : neurobiological and epidemiological studies

Chotai, Jayanti January 1999 (has links)
Background: Several neuropsychiatrie disorders have shown season of birth associations. Low cerebrospinal fluid (CSF) levels of the serotonin metabolite 5-HIAA and the dopamine metabolite HVA have been associated with suicidal behaviour, impulsivity, and aggression. This thesis investigated associations between the season of birth, the CSF levels of three monoamine metabolites (including MHPG of norepinephrine), the scales of the diagnostic interview for borderline patients (DIB), and psychiatric diagnoses. Also, the methods of suicide were investigated in relation to the season of birth. Methods: We studied a clinical sample of 241 patients in Stockholm with mood, anxiety and adjustment disorders with respect to the CSF levels of monoamine metabolites in relation to the season of birth, and in relation to the DIB in an overlapping sample. We also analysed all completed suicides during the 42 years 1952- 1993inVästerbottenin northern Sweden (1466 cases) by multiple logistic regressions to relate suicide methods with season of birth, gender, age, urban-rural residence, marital status, year of suicide, and season of suicide. For the 20 years 1961- 1980 (693cases), psychiatric in-patient and out-patient records were also examined for any history of psychiatric contacts and psychiatric diagnoses. In two mutually independent samples, we investigated the DIB in relation to the season of birth. Results: In the Stockholm sample, those born during February to April had significantly lower CSF levels of 5-HIAA, and those born during October to January had significantly higher CSF levels of HVA, HVA/5-HIAA, and HVA/MHPG, as well as (non-significantly) higher levels of 5-HIAA. Those with an intermediate score of section II (impulse action patterns) of the DIB had significantly higher CSF levels of 5-HIAA and HVA, and they were significantly more likely to have been born during October to January. In the Västerbotten register, those born during February to April were significantly more likely to have preferred hanging rather than poisoning or petrol gases, and conversely for those born during October to January. These associations with suicide methods were found for the total sample and for those without any history of psychiatric contacts, but not for those with psychiatric contacts. Conclusions: Suicidal behaviour shows statistically significant variation according to the season of birth, most probably mediated by a variation in an independent trait of vulnerability to suicide based on neurodevelopmental parameters, particularly the serotonergic system. The suicidal process differs between those who seek psychiatric care compared to those who do not, reflecting differences in the diagnostic spectra and in the extent of mental illness. / <p>Härtill 6 delarbeten.</p>
68

The Effect of Season of Fire on Post-fire Legacies in Northwestern Ontario Red Pine (<em>Pinus resinosa</em>) Mixedwoods

Woodman, Brett January 2005 (has links)
Prescribed burns are employed in the southern boreal forest of northwest Ontario, Canada, as a method of re-instating fire in this fire-dependent landscape. They are also used to manage fuel loads associated with tree mortality from defoliating insects and from blow-downs, as well as in-site preparation following harvest. The natural fire season in boreal Canada typically runs from April through September and is most often characterized by stand replacing fires. However, prescribed burns in northwestern Ontario are mostly scheduled for October when fire crews and equipment are available and fire hazard is reduced. In this study, three recent fires: a spring prescribed natural fire, a summer wildfire, and a fall prescribed burn were examined to assess the effect of season on post-fire legacies in red-pine mixedwood stands in Quetico Provincial Park, northwestern Ontario. Legacies were assessed by tree, shrub and herb species composition, and by measurements of structure such as litter depth, basal areas of live trees and coarse woody debris. Tree species diversity was nearly identical. Post-fire stand structure varied widely between the different sites. The spring treatment experienced the least mortality of trees (10% of basal area dead); the summer treatment had the highest mortality (100%); and the fall prescribed burn was intermediate with 49% dead. The effect of the fall burn on the forest was probably more intense than that of a comparable natural fall fire because of the way in which it was managed, thus partly compensating for the late season. <br /><br /> This research suggests that all fires are not equal. Different post-fire structure will have lasting ecological implications such as varying edge to interior ratios, and forest habitats. From a policy perspective this is important because maintaining ecological processes including fire is mandated for some provincial parks. In addition, the new Fire Policy for Ontario has established targets to limit wildfires, and permit ecologically renewing fires, without recognition of the variability of the effects of fire or fire legacies.
69

The Effect of Season of Fire on Post-fire Legacies in Northwestern Ontario Red Pine (<em>Pinus resinosa</em>) Mixedwoods

Woodman, Brett January 2005 (has links)
Prescribed burns are employed in the southern boreal forest of northwest Ontario, Canada, as a method of re-instating fire in this fire-dependent landscape. They are also used to manage fuel loads associated with tree mortality from defoliating insects and from blow-downs, as well as in-site preparation following harvest. The natural fire season in boreal Canada typically runs from April through September and is most often characterized by stand replacing fires. However, prescribed burns in northwestern Ontario are mostly scheduled for October when fire crews and equipment are available and fire hazard is reduced. In this study, three recent fires: a spring prescribed natural fire, a summer wildfire, and a fall prescribed burn were examined to assess the effect of season on post-fire legacies in red-pine mixedwood stands in Quetico Provincial Park, northwestern Ontario. Legacies were assessed by tree, shrub and herb species composition, and by measurements of structure such as litter depth, basal areas of live trees and coarse woody debris. Tree species diversity was nearly identical. Post-fire stand structure varied widely between the different sites. The spring treatment experienced the least mortality of trees (10% of basal area dead); the summer treatment had the highest mortality (100%); and the fall prescribed burn was intermediate with 49% dead. The effect of the fall burn on the forest was probably more intense than that of a comparable natural fall fire because of the way in which it was managed, thus partly compensating for the late season. <br /><br /> This research suggests that all fires are not equal. Different post-fire structure will have lasting ecological implications such as varying edge to interior ratios, and forest habitats. From a policy perspective this is important because maintaining ecological processes including fire is mandated for some provincial parks. In addition, the new Fire Policy for Ontario has established targets to limit wildfires, and permit ecologically renewing fires, without recognition of the variability of the effects of fire or fire legacies.
70

Vem bestämmer musiken? : En undersökning av en symfoniorkesters säsongsprogramsarbete

Johansson, Ida January 2009 (has links)
ABSTRACT There is a limited possibility for many of the concert-goers to go behind the stage and follow the work process with putting together a program for the concert season in a concert institution. The purpose of this study is to describe a concert institution's work with developing a concert program for each season. This is done through a presentation of the factors affecting the work. This is a descriptive essay and a case study of the Malmö Symphony Orchestra. Interviews have been made with people directly involved in the work or affected by the outcome of the work process. The results of the survey show that there are many opinions about the choice of repertoire and the program is greatly influenced by the chosen conductors and their preferences. The underlying repertoire ideology is a factor that permeates the work. The ideology and the view of symphony music as public education have to be compromised with the various interests involved in the working process. The survey also shows that the audience is not taken into account in the process as much as I expected before the survey. Key words: repertoire, symphony orchestra, concert, season, conductor

Page generated in 0.0158 seconds