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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.
31

Efficacité d'espèces ligneuses en symbiose mycorhizienne arbusculaire pour la phytoremédiation d'un site urbain contaminé

Bissonnette, Laurence January 2009 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal
32

Vliv genotypu, stanoviště a agrotechniky na produkci fytomasy vybraných energetických dřevin / The influence of genotype , habitats and agricultural technologies for producing energy wood phytomass selected

CHRT, Vladimír January 2015 (has links)
This diploma thesis deals with the cultivation of fast-growing wood and concentrates on the influence of particular factors like e.g. location, agrotechnology and fertilizers, which have a crucial impact on the phytomass production. Moreover, the thesis evaluates the economic efficiency of this type of sustainable energy ressource, which can be a source of local business. Introductory theoretical chapters describe essentials rules of the cultivation of fast-growing wood. Furthermore the thesis presents general information in this field and proposes suitable wood clones. In addition, the thesis outlines the process of choice and preparation of the agricultural parcel, the usage of various fertilizes, herbicides and agrotechnology. The applied core characterises the business case itself. The primary research compares financial investment and its return of two examined agricultural parcels under the prerequisit of suitable choice of location and agrotechnology. A trail phase depictes the cultivation of fast-gworing wood and discuss presumptions for succesfull business. This thesis is mainly based on primary research. The acquired data are further analyzed and the final chapter attempts to outline the results and suggest measures.
33

Společenstva epigeických brouků plantáží rychle rostoucích dřevin a okolních biotopů / Communities of epigeic beetles (\kur{Coleoptera}) on the plantations of trees for energetic purposes

ZUKAL, Radim January 2013 (has links)
The aim of the study was to examine communities of epigeic beetles in the plantations of fast-growing trees (poplar clone Japanese J - 105 (Jap = - 105, Max - 4, Maxvier) and surrounding habitats (Zea mays L.). A cover of Zea mays L. was used as an area for comparison. Sampling was carried out in 2012 by using the method of epigeic beetles in pitfall traps (period from May to September). During the sampling, altogether 1054 specimens and 57 species of epigeic beetles were collected. In the area of fast-growing trees ?Na Vrbovecku? 528 specimens were collected which is many times more than in other researched areas. In the cover of Zea mays L. in the area "Na Vrbovecku" 293 specimens were collected and in the zone of fast-growing trees "U rybníka" 233 specimens were catched; notice the high similarity in the number of collected specimens. At all sites surveyed the expansive species (E) outnumbered the II relics. There were about 70% of expansive species in the cover of Japanese poplar found and in the cover of Zea mays L. there were about 90% of expansive species found. The number of more adaptable species- RII category- found in the cover of Japanese poplar was approximately 30% unlike the number of the same species found inside the Zea mays L. cover was only 12%. The rare species Xantholinus gallicus of the RI category was found in the plantations of fast-growing trees "U rybníka". The index of anthropogenic impact on communities (ISD) was very low in studied plots. In the Zea mays L.cover the index was only 6 points, unlike in the cover of Japanese poplar where the index reached 24 points. Yet all researched areas show high anthropogenic impact. Based on the obtained results (epigeic beetles), it seems that plantations of fast-growing trees have a positive impact on communities of epigeic beetles in cultural landscape. Since the research was always carried out on a farmed landscape, the impact of surrounding landscape on gained results is minimal and insignificant.
34

Efektivní využití fytomasy v ochranném pásmu NP Podyjí / Effective use of phytomass in the protected area of the National Park Podyjí

FORMANOVÁ, Petra January 2014 (has links)
The objective of the thesis is to evaluate the possibility of the effective use of waste and phytomass specifically grown for energy purposes in the protected area of National Park Podyjí. The task was to characterize the source of phytomass in this environmentally sensitive area. The data were collected by studying documents, visits to enterprises and institutions, and personal consultations with business and other stakeholders. The result of this work is a brief assessment of the production potential and the factors influencing its development. Due to the nature of the territory, to suggest measures for efficient use of land for the production of energy phytomass with regard to the attitudes of farmers and the authority of nature and landscape.
35

Analýza ochranných funkcí lesních porostů tvořených rychle rostoucími dřevinami. / Analyse of protective functions of forest crops totalled by the fast-growing timber species

HOMOLKA, Lukáš January 2009 (has links)
The goal of thesis is an analyse of protective functions of fast-growing timber species and a set of theirs part in the total non-energic meaning. The meaning of these timber species is very wide. The analyse is focused on first of all ameliorative function, and on sinking of wind erosion impact, then on insulating function, containing appreciation of impact on sinking of noisiness and catch of dustiness in an environment, and sanitation function which is represented by the production of oxygen.
36

Estimativa da biomassa de lenho em povoamentos de Eucalyptus grandis baseada em estatísticas do perfil de dossel geradas por escaneamento a laser aerotransportado / Stem biomass estimation of a Eucalyptus grandis plantation based on canopy height profile statistics generated by airborne laser scanning

Andre Gracioso Peres da Silva 18 June 2014 (has links)
Este trabalho contribui para a evolução dos métodos que lidam com a quantificação de biomassa em plantações florestais em grande escala. Mais especificamente, explora o potencial de novos métodos baseados em sistemas de escaneamento a laser aerotransportado (ALS) que produzem uma representação 3D da estrutura vertical e horizontal acima do solo em plantios de Eucalyptus spp. A abordagem assume que a biomassa acima do solo pode ser estimada de forma precisa quando o perfil vertical da altura do dossel e a área basal são bem conhecidos. Assim, quatro questões foram analisadas: (i) se a função de densidade probabilidade Weibull com dois parâmetros (escala ? e forma ?) consegue descrever com precisão a distribuição vertical de pontos gerada pela tecnologia ALS e gerar um perfil aparente de altura de dossel adequado em plantios de eucalipto; (ii) se quando gerada por tecnologia ALS, a proporção de retornos no subdossel e solo tem relação significativa e positiva com a variável área basal; (iii) qual a qualidade da predição de área basal e de biomassa seca de lenho quando são usadas como variáveis explicativas um percentil baixo de altura da nuvem ALS e o parâmetro de escala da distribuição Weibull ajustada para definir o perfil vertical do dossel; e (iv) qual a qualidade dos mapas de biomassa de lenho de plantios de eucaliptos quando produzidos a partir de dois métodos diferentes, um de interpolação de dados das parcelas de campo (krigagem ordinária) e outro que usa a nuvem de pontos ALS para calibrar as informações das parcelas de campo (regressão linear). Os resultados mostraram que a função Weibull de dois parâmetros ajustou com precisão adequada o perfil das alturas do plantio de eucalipto. Do ponto de vista prático, esse resultado reforça as estratégias de uso dos parâmetros da função Weibull (escala e forma) como métricas que caracterizam adequadamente a estrutura vertical dos povoamentos florestais. A estimativa de área basal em função da proporção de retornos no subdossel e no solo mostrou-se moderada (R² = 0.42 e rRMSE = 7.6%), sendo necessários mais estudos que investiguem essa relação. As predições de área basal e biomassa do lenho foram aprimoradas em função do parâmetro ? da função Weibull, usado como estimador de escala para as alturas do dossel (área basal, R² = 0.77 e rRMSE = 4.8% e biomassa do lenho, R² = 0.89 e rRMSE = 5.1%). As variáveis, percentil 30 e parâmetro de forma (?) da função Weibull, também produziram boas estimativas (R² = 0.82 para área basal e R² = 0.93 para biomassa de lenho). Os mapas de predição de biomassa de lenho mostraram-se mais precisos quando derivados a partir de dados ALS (rRMSE = 5.5% versus 12.7% na interpolação por krigagem ordinária). / This work contributes to the evolution of methods dealing with the quantification of biomass in large-scale forest plantations. More specifically, it explores the potential of new methods based on airborne laser scanning systems to produce a 3D representation of the vertical and horizontal structure of above ground Eucalyptus spp plantations. The approach assumes that above ground biomass can be precisely estimated when the vertical profile of canopy heights and basal area are well known. Thus, four questions are examined: (i) can the Weibull probability density function (pdf) with two parameters (? scale and ? shape) describe accurately the vertical distribution of points generated by the ALS technology and generate an adequate apparent profile of canopy heights for the eucalyptus plantation?; (ii) when generated by the ALS technology, is the proportion of understory returns to ground returns significantly and positively related with basal area?; (iii) how well are basal area and dry stem biomass predicted by models using low height percentile values of the ALS point cloud and the scale parameter of the Weibull distribution describing the vertical canopy profile?; and (iv) how accurate are stem biomass maps of the eucalyptus plantation when two different methods are used, one based on interpolation that uses sample plots information (ordinary kriging) and another that uses the ALS point cloud to calibrate the sample plot information (linear regression)? The results showed that the Weibull pdf with two parameters fitted with adequate accuracy the plantation\'s height profiles. From a practical standpoint, this result reinforces the strategies of using the Weibull parameters (scale and shape) as metrics that adequately characterize the vertical structure of forest stands. Basal area estimates derived from the proportion of understory and ground returns presented only moderated accuracy (R² = 0.42 e rRMSE = 7.6%) and more research is needed to investigate such relationship. Good results were obtained when basal area and stem biomass were fitted as a function of the Weibull ? parameter, as a proxy for the scale of canopy heights (basal area, R² = 0.77 e rRMSE = 4.8%, and stem biomass, R² = 0.89 and rRMSE = 5.1%). The explanatory variables percentile 30 and the Weibull shape parameter (?) also produced good estimates (R² = 0.82 for basal area and R² = 0.93 for stem biomass). Stem biomass prediction maps showed to be more accurate when derived from ALS data (rRMSE = 5.5% against 12.7% derived from ordinary kriging interpolation).
37

Estudo de parâmetros populacionais de plantios clonais de Eucalyptus spp. a partir de nuvens de pontos obtidos com escaneamento a laser aerotransportado / Study of population parameters from clonal Eucalyptus spp. plantation using point clouds obtained with airborne laser scanning

Danitiele Cristina França Laranja 11 July 2016 (has links)
As florestas plantadas contribuem para o desenvolvimento econômico, social e ambiental brasileiro, e o setor florestal busca plantios cada vez mais produtivos e melhor aproveitados. A tecnologia a laser aerotransportada (ALS - Airborne Laser Scanning), capaz de gerar informações tridimensionais precisas em extensas áreas e em pequeno intervalo de tempo, tem se destacado nas aplicações florestais, sendo utilizada na quantificação e caracterização de florestas. Neste estudo foram utilizados dados ALS obtidos em dois sobrevoos (2013 e 2014), cobrindo uma área de plantio do gênero Eucalyptus com diferentes clones e idades, localizada no estado de São Paulo. Esta dissertação é dividida em três partes. A primeira buscou avaliar a combinação de métricas ALS e de dupla amostragem nas estimativas de volume e na redução da intensidade amostral, comparando seus resultados aos de métodos amostrais tradicionais. Os resultados mostraram que a dupla amostragem obteve o menor erro de amostragem dentre os delineamentos, permitindo a redução do esforço amostral. A segunda parte visou caracterizar as diferenças estruturais existentes entre clones de eucalipto, com diferentes idades, a partir de métricas ALS e perfis de altura do dossel (CHP). O estudo mostrou que é possível distinguir a estrutura do dossel dos clones, o que pode contribuir com melhorias nas estimativas e no gerenciamento dos plantios comerciais. Na última parte, foram avaliados dois algoritmos de detecção de árvores individuais quanto à quantificação dos indivíduos e os efeitos da composição (tamanho de célula e filtragem) do modelo digital de alturas (CHM) no desempenho desses algoritmos. Verificou-se que as características do CHM influenciam na detecção. A estratégia com melhor desempenho resultou em um erro médio relativo de 11% no número de indivíduos. / Planted forests contribute to the economic, social and environmental development of Brazil, and the forest industry aims to increase productivity and the efficient use of these plantations. Airborne Laser Scanning (ALS) technology, capable of generating accurate three-dimensional information, covering large areas in a short time, has highlighted potential in forestry applications and has been applied in forests quantification and characterization. In this study, ALS data were obtained from two flights (2013 and 2014), covering a Eucalyptus plantation area with different clones and ages, in the state of São Paulo. This thesis comprises three parts. The first study aimed to evaluate the combination of ALS metrics and double sampling design for volume estimates and reducing sampling intensity, comparing the results to traditional sampling methods. Results showed that the double sampling had the lowest error from the designs, allowing the reduction of the sampling effort. The second part was proposed to characterize the structural differences between Eucalyptus clones with different ages, based on metrics ALS and canopy height profiles (CHP). The study showed that it is possible to distinguish the canopy structure of the clones, which can contribute to improvements in estimates and management of commercial plantations. In the last study, two individual tree detection algorithms were evaluated for quantification of individuals, and the effect of the canopy height model (CHM) composition at the performance of these algorithms was analyzed. It was found that the CHM characteristics influence the tree detection. The strategy with better performance resulted in an average relative error of 11% in number of trees.
38

Avaliação do potencial das formigas como vetores mecâncios de micobactérias em hospital especializado na assistência de pacientes de tuberculose no Estado de São Paulo / Evaluation of ants as potential mechanical vectors of mycobacteria in a hospital specializing in assistance to TB patients, the state of São Paulo

Ana Paula Macedo Ruggiero Couceiro 02 April 2012 (has links)
Introdução - A urbanização desencadeia inúmeros transtornos, como a disseminação de artrópodes e, conseqüentemente, de doenças veiculadas pelos mesmos. As formigas são muito adaptáveis e se beneficiam com a convivência humana. Nos hospitais, elas podem ser vetores mecânicos de inúmeras bactérias, e a diversidade de espécies encontradas nestes ambientes, causam preocupação pelo risco potencial à saúde pública. O aumento das infecções hospitalares envolvendo micobactérias ambientais, com surtos no Brasil entre 1998 a 2009 em 23 estados alarmou os órgãos e profissionais de saúde pública. Objetivos - Avaliar o potencial de formigas como vetores de micobactérias em um hospital especializado no atendimento de doentes com tuberculose. Métodos - Foram realizadas seis coletas de formigas em diferentes áreas do hospital no período de 2009 a 2010, que foram semeadas em meios de cultura de Löwenstein-Jensen e de Stonebrink para isolamento de micobactérias. As culturas sugestivas foram submetidas à coloração de Ziehl-Neelsen para bacilos álcool-ácido resistentes e identificação por métodos moleculares (PRA para o gene hsp65 com o par de primers TB11 e TB12 gênero-específico e sequenciamento genético do DNA). Resultados - Do total de 247 amostras de formigas coletadas e semeadas, 70 por cento das formigas pertenciam à espécie Tapinoma melanocephalum, 25 por cento a espécie Dorymyrmex sp., 3 por cento a espécie Camponotus sp. e 2 por cento a espécie Pheidole sp., dados similares foram observados anteriormente em pesquisas realizadas em hospitais. Quinze amostras apresentaram bacilos álcool-ácido resistentes de crescimento rápido. Nos métodos moleculares, doze pertenciam ao Gênero Mycobacterium. No PRA-hsp 65, e no sequenciamento genético do DNA, quatro amostras foram identificadas quanto à espécie (duas Mycobacterium chelonae, uma Mycobacterium parafortuitum e uma Mycobacterium murale), quatro micobactérias com resultados idênticos no PRA e não identificadas no sequenciamento foram sugestivas de uma nova espécie, e duas amostras não foram identificadas. Mycobacterium chelonae isolada nesta pesquisa foi previamente descrita como agente causador de abscessos em humanos. Conclusão - Estes dados confirmam a presença de micobactérias veiculadas por formigas no ambiente hospitalar, representando um potencial vetor mecânico destas para pacientes e profissionais de saúde, principalmente em infecções nosocomiais / Introduction- Urbanization triggers numerous disorders, such as the dissemination of arthropods and, consequently, dissemination of diseases transmitted by them. Some ant species are very adaptable to the human environment. At hospitals, once they are mechanical vectors of bacteria, and the diversity of species found in these environments, they can represent a potential risk to public health. The increase of nosocomial infections involving environmental mycobacteria, with outbreaks in Brazil from 1998 to 2009 in 23 states called the interest of health professionals and health agencies. Purpose - Evaluate the potential of ants as vectors of mycobacteria in a hospital specialized in the care of patients with tuberculosis. Methods Samples of ants were collected from different areas of the hospital from 2009 to 2010, and workers were inoculated in Löwenstein-Jensen and Stonebrink media for mycobacteria isolation. The suggestive cultures were subjected to Ziehl-Neelsen stain for acid-fast bacilli and identification were performed by molecular methods (PRA for the hsp65 gene with the pair of primers TB11 - TB12 and genetic sequencing). Results - The total of 247 samples of ants collected and sown, 70 per cent belonged to species of ants Tapinoma melanochepalum, 25 per cent Dorymyrmex sp.,3 per cent Camponotus sp. and 2 per cent Pheidole sp., data similar with previous studies conducted in hospitals. Fifteen fast-growing mycobacteria were isolated. In molecular methods, twelve belonged to the genus Mycobacterium. In PRA-hsp65, and the genome sequencing of DNA, four samples were identified at species level (two Mycobacterium chelonae, one Mycobacterium parafortuitum and one Mycobacterium murale), four mycobacteria with similar results in the PRA and not identified in the sequencing, suggestive of a new species and two unidentified samples. M. chelonae was previously reported as causative agent of abscess in humans. Conclusions - These results confirm the presence of mycobacteria carried by ants in the hospital, representing a potential mechanical vector for these patients and healthcare professionals, particularly in nosocomial infections
39

Ekonomika rychle rostoucích dřevin / Economy of fast-growing woody species

Levý, Lukáš January 2011 (has links)
The thesis is focused on analyzing and evaluation of importance and potential of fast-growing woody species for specifics of Czech economy and local conditions. Thesis will inquire into applicability of each fast-growing species for Czech natural conditions. Further I will investigate opportunities of subvention from public authorities. Next part of thesis will be focused on all activities and processes during cultivation of fast-growing species from acquiring land to processing of wooden mass. For each activity will quantify costs of labor and physical capital during cultivation of fast-growing woody species for different subjects in Czech economy, like household owning a soil or company with unused outside areas. Thesis will be comparing possible energetic savings of profits for a number of alternatives with different energy prices development in ongoing years. Practical output of this thesis should not be only the compilation of all these information into one text, but above all also a complex formula which everyone can use for the calculation of his opportunities for cultivating of fast-growing woody species.
40

Influência do tratamento térmico nas propriedades químicas, físicas e mecânicas de madeiras de reflorestamento /

Oliveira, Carolina Aparecida Barros January 2020 (has links)
Orientador: Julio Cesar Molina / Resumo: O tratamento térmico é um processo realizado com madeiras para aumentar a durabilidade e mudar a aparência. Nesse processo vários fatores devem ser observados para um melhor aproveitamento do potencial mecânico da madeira, dentre eles: tempo, temperatura e velocidade de aquecimento. Observa-se que na maioria dos estudos já realizados sobre esse tema algumas espécies de madeira ainda não tiveram todas as suas propriedades mecânicas analisadas. Além disso, a maior parte dos estudos desenvolvido no Brasil considera o aquecimento da madeira em estufa com ambiente controlado. O objetivo desse trabalho consistiu em avaliar a influência do tratamento térmico realizado industrialmente para as temperaturas 155, 165, 175 e 185 ºC nas propriedades químicas, físicas e mecânicas de madeiras de Eucalipto grandis (Eucalyptus grandis), Pinus taeda (Pinus taeda L.), Cedro indiano (Acrocarpus fraxinifolius) e Cedro australiano (Toona ciliata var. australis), em relação às respectivas propriedades das madeiras in natura. O tratamento térmico das madeiras foi realizado em autoclave com controle de temperatura e de pressão com ingestão de vapor saturado. Após o tratamento térmico a análise química identificou, para as quatro espécies estudadas, um aumento nos teores de extrativos e redução nos teores de holocelulose; o teor de lignina aumento para o Pinus taeda e o Cedro australiano e não apresentou modificações estatisticamente significantes para o Eucalipto grandis e Cedro indiano. A densidade ... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

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