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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.
471

Mamiferos de médio e grande porte em florestas de Eucalyptus spp com diferentes densidades de sub-bosque no município de Itatinga, SP / Medium and large-sized mammals in forests of Eucalyptus spp with different densities of understories in Itatinga, state of São Paulo, Brazil

Patrícia Batista da Silveira 06 December 2005 (has links)
Estudos de fauna em florestas homogêneas de plantio comercial são ainda incipientes no país. Essas áreas de reflorestamento apresentam poucos recursos necessários à vida silvestre, quando comparadas às florestas nativas. Entretanto, sub-bosques presentes nessas florestas homogêneas podem fornecer ofertas de alimento, abrigo, proteção, e o estabelecimento de um ambiente favorável à movimentação dos animais - otimizando assim o uso desses locais pela fauna silvestre. Este estudo foi realizado no Horto Florestal de Itatinga, uma área com predomínio de florestas de eucalipto (Eucalyptus spp), e com remanescentes de vegetação nativa (floresta estacional semidecidual, cerrado, cerradão e áreas ripárias), localizada no município de Itatinga, no estado de São Paulo. A fim de verificar se a presença e a densidade do sub-bosque nas florestas de eucaliptos influenciam no uso desses locais pelos mamíferos de médio e grande porte, foram comparados três tipos de ambientes de eucalipto: um talhão de eucalipto sem subbosque, um talhão de eucalipto com sub-bosque intermediário, e um talhão de eucalipto com subbosque denso. Em cada um desses ambientes foram colocadas 24 parcelas de areia (armadilhas de pegadas) com iscas alimentares (banana, bacon e sal), para a observação do número de pegadas dos animais nas mesmas. Foram verificados os números de registros, as freqüências de ocorrência e as abundâncias relativas das espécies de mamíferos em cada ambiente, durante 15 dias do inverno de 2004 (estação seca) e 15 dias do verão de 2005 (estação chuvosa). O número de registros foi maior no ambiente de eucalipto com sub-bosque denso, e a riqueza de espécies foi maior no eucalipto com sub-bosque intermediário. O teste do Qui-quadrado (χ2) mostrou diferença significativa no número de registros entre os três ambientes, e entre os períodos inverno e verão. Foram verificadas as categorias tróficas dos mamíferos levantados nesses locais, e observou-se que os animais encontrados foram, em sua maioria, animais de hábitos mais generalistas e pouco exigentes quanto ao habitat. Foram encontradas no total 10 espécies de mamíferos de médio e grande porte nesses ambientes de eucalipto. A curva do coletor não mostrou estabilização, indicando que ainda havia espécies a serem levantadas nesses três ambientes de eucaliptos. Foi também realizado um levantamento qualitativo dos mamíferos de médio e grande porte na área de estudo em geral. Para isso, foram observados registros diretos e indiretos da mastofauna, como visualização de animais, pegadas, fezes, pêlos, tocas e carcaças; foram efetuadas também entrevistas, e houve a instalação de uma câmera trap (armadilha fotográfica). Este levantamento geral ocorreu durante 75 dias (entre julho de 2004 e abril de 2005). Foram encontradas 27 espécies de mamíferos nesse levantamento, mas a curva do coletor aplicada a esses registros também não se estabilizou. A maioria dos animais levantados são de hábitos alimentares generalistas; entretanto, foram registrados pelo menos quatro espécies de carnívoros (mais exigentes quanto à qualidade do habitat). Foram acusadas as presenças de oito espécies de mamíferos ameaçados de extinção no Horto de Itatinga. / Fauna studies in homogeneous forests for commercial plantation purposes are still incipient in the country. These reforestation areas present a few resources necessary to the maintenance of wild life, when compared to the native forests. However, understories present in these homogeneous forests can provide food, shelter, protection and the establishment of a favorable environment to animal movement – thus, optimizing the use of these reforestation areas by the wild fauna. This study took place in the Horto Florestal de Itatinga, an area of mostly eucalypts forests (Eucalyptus ssp) and remaining fragments of native vegetation (semideciduous seasonal forests, savannah and riparian forests), located in Itatinga, state of São Paulo, Brazil. In order to verify if the presence and density of the understories in the eucalypt forests influence in the use of these locations by medium and large-sized mammals, three types of eucalypt environment were compared: a stand of eucalypt without understory, a stand of eucalypt with intermediate understory an a stand of eucalypt with dense understory. Each of these environments received 24 sand plots (tracking traps) containing alimentary baits (banana, bacon and salt), for the observation of the number of animal tracks in each one of them. Registry numbers, frequency of occurrence and the relative abundance of mammals species in each environment, throughout 15 winter days in 2004 (dry season) and 15 summer days in 2005 (wet season), were verified. In the eucalypt environment with dense understory record numbers were higher, and in the eucalypt environment with intermediate understory the richness of species was bigger. The chi-square test (χ2) showed significant difference in registry numbers among these three environments, as well as between winter and summer periods. Dietary categories of the mammals observed in these sites were verified, and most of the observed animals belonged to generalist species, and they were not so demanding concerning their habitat. Ten species of medium and large-sized mammals were found in these eucalypts environments all told. The collector’s curve was not stabilized, indicating that there were still other species to be surveyed in these three environments with eucalypts. A qualitative survey of medium and large-sized mammals in the study area in general, was also carried out. For this purpose, direct and indirect records of the mammals, as well as the visualization of these animals, their tracks, feces, hairs, burrows and carcasses were observed. Local people were interviewed and one camera trapping installed. This survey took place throughout 75 days (between July, 2004 e April, 2005). Twenty-seven species of mammals were found in this survey, but the collector’s curve was not stabilized too. Most of the animals observed in this study belonged to generalist species; but at least four species of carnivores (animals are more demanding concerning their habitat) were recorded. This study also accused the presence of eight endangered species in the Horto de Itatinga.
472

Moscas-das-frutas em citros: densidade de armadilhas para monitoramento, efeito do pH na atração e determinação do nível de controle. / Fruit flies in orange groves: trap density for monitoring, effect of attractant ph and establishiment of an action threshold level.

Paulo Eduardo Branco Paiva 27 August 2004 (has links)
Este trabalho teve por objetivos: avaliar o efeito do pH inicial e o tempo de permanência no campo do atrativo alimentar Milhocina® com o conservante bórax (tetraborato de sódio) na captura de moscas-das-frutas em armadilhas do tipo McPhail; estudar densidades de armadilhas para monitoramento de moscas-das-frutas e determinar um nível de dano e de controle em cultura de laranja. Foram realizados três experimentos de campo, o primeiro em junho de 2002 em pomar de laranja de maturação precoce, cultivar Hamlin, em Itaju, região central do estado de São Paulo, para se avaliar a captura de moscas-das-frutas em armadilhas com os atrativos Milhocina® em pH 4,5, Milhocina® com bórax em pH 4,5, 6,5 e 8,5, aos 2, 4, 6 e 8 dias após a instalação no pomar. O segundo experimento foi desenvolvido de junho a agosto de 2002 (inverno seco) com laranja Hamlin em Itaju, e o terceiro experimento foi realizado de janeiro a março de 2003 (verão chuvoso) com laranja de maturação tardia, cultivar Natal, em Porto Feliz, região sul do estado, ambos para se avaliar as densidades de uma, duas, quatro e oito armadilhas por hectare e a relação entre a captura de moscas-das-frutas nas armadilhas e frutos danificados. Em Itaju, as maiores capturas de Ceratitis capitata (Wiedemann, 1824) ocorreram nas armadilhas com o atrativo protéico Milhocina® e bórax em pH 8,5, aos 2, 4 e 6 dias. A espécie predominante, com quase 99% das moscas-das-frutas capturadas, foi C. capitata, sendo a proporção de fêmeas capturadas de 80% em pomar com frutos e 46% em pomar sem frutos. As capturas de fêmeas, machos, e total (fêmeas e machos) de C. capitata por armadilha, nas densidades de uma, duas, quatro e oito armadilhas por hectare, foram semelhantes, indicando que C. capitata pode ser monitorada com uma armadilha por hectare em áreas de altas populações de moscas. Houve correlações entre a captura de fêmeas, e fêmeas e machos de C. capitata, e o número de frutos de laranja precoce ‘Hamlin’ danificados, sete e quatorze dias após a coleta, nas densidades de uma e duas armadilhas por hectare. Foram obtidas equações que relacionam a captura com o dano. Assim, para um dano de um fruto por árvore, o nível de controle poderia ser de 8 a 16 indivíduos de C. capitata por armadilha por dia. As perdas médias estimadas devido ao ataque de C. capitata em laranja precoce chegaram a 2,5 toneladas de frutos por hectare, ou 7,5% da produção. Em Porto Feliz, onde predominou Anastrepha fraterculus (Wiedemann, 1830), as capturas foram baixas e o dano foi observado mais freqüentemente não sendo correlacionado com as capturas de moscas-das-frutas nas armadilhas. / This research aimed to evaluate the effect of different levels of pH and the exposure time of the trap in the field, baited with Milhocina® and borax (sodium borate), on capturing fruit flies, to study different densities of McPhail trap for monitoring fruit flies and to establish the relation between fruit fly catches in traps and damaged orange fruits to determine injury and action threshold levels for fruit flies in orange groves. Three field experiments were carried out: the first one conducted in June of 2002 in a ‘Hamlin’ orange grove in Itaju, central region of state of Sao Paulo, to evaluate the trap with Milhocina® as attractant at pH 4.5 and Milhocina® and borax at pH 4.5, 6.5 and 8.5. Counts of fruit fly numbers were done at 2, 4, 6 and 8 days after placing the trap in the orange grove. The second experiment was conducted from June to August of 2002 (during dry winter) in a ‘Hamlin’ orange grove in Itaju, and the third one was conducted from January to March of 2003 (during rainy summer) in a ‘Natal’ orange grove in Porto Feliz, in southern region of state of Sao Paulo, both to evaluate the densities of one, two, four and eight traps per hectare and to study the relationship between fruit fly catches in the traps and damaged fruits. In Itaju, the highest catches of Ceratitis capitata (Wiedemann, 1824) were observed in traps baited with Milhocina® and borax at pH 8.5 after 2, 4 and 6 days. The most abundant fruit fly species was C. capitata, comprising almost 99% of the fruit flies captured, and the proportion of female catches was 80% in groves with fruits and 46% in groves without fruits. The fruit fly catches per trap were similar at different trap densities, indicating that C. capitata could be monitored by using one trap per hectare in areas with high fruit fly populations. Significant linear correlations were observed between females, males and females catches and damaged fruits in the following week and one week later, at densities of one and two traps per hectare. The action threshold level estimated ranged from 8 to 16 C. capitata per trap per day for one damaged fruit per tree. The mean estimated damage caused by C. capitata in ‘Hamlin’ orange was 2,500 kg of fruits per hectare which corresponds to 7.5% of the total yield. Anastrepha fraterculus (Wiedemann, 1830) was the predominant species in Porto Feliz. In this experiment, the fruit fly catches were low, the intensity of damaged fruits was higher and there was no correlation with fruit fly catches in the traps.
473

Central bank balance sheet concerns and credible optimal escape from the Liquidity trap

Mendes, Arthur Galego January 2013 (has links)
Submitted by arthur mendes (agalegomendes@gmail.com) on 2013-10-30T18:04:37Z No. of bitstreams: 1 Dissertação_Final.pdf: 393524 bytes, checksum: a6e35ab46f67c3472d55a57b0bad00ab (MD5) / Approved for entry into archive by Janete de Oliveira Feitosa (janete.feitosa@fgv.br) on 2013-11-01T16:53:40Z (GMT) No. of bitstreams: 1 Dissertação_Final.pdf: 393524 bytes, checksum: a6e35ab46f67c3472d55a57b0bad00ab (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2013-11-13T17:27:59Z (GMT) No. of bitstreams: 1 Dissertação_Final.pdf: 393524 bytes, checksum: a6e35ab46f67c3472d55a57b0bad00ab (MD5) / Made available in DSpace on 2013-11-13T17:33:26Z (GMT). No. of bitstreams: 1 Dissertação_Final.pdf: 393524 bytes, checksum: a6e35ab46f67c3472d55a57b0bad00ab (MD5) Previous issue date: 2001-06-13 / I show that when a central bank is financially independent from the treasury and has balance sheet concerns, an increase in the size or a change in the composition of the central bank's balance sheet (quantitative easing) can serve as a commitment device in a liquidity trap scenario. In particular, when the short-term interest rate is up against the zero lower bound, an open market operation by the central bank that involves purchases of long-term bonds can help mitigate the deation and a large negative output gap under a discretionary equilibrium. This is because such an open market operation provides an incentive to the central bank to keep interest rates low in future in order to avoid losses in its balance sheet.
474

Longshore sediment transport driven by sea breezes on low-energy sandy beaches, Southwestern Australia

Tonk, Aafke M. January 2004 (has links)
Longshore sediment transport rate was measured during energetic sea breeze activity, on intermediate-to-reflective sandy beaches in Southwestern Australia. Estimates of suspended load were obtained using backscatter sensors, current meters and streamer traps. Total load was determined using fluorescent tracer sand and an impoundment study. The measurementsw ere cross-compareda nd usedt o evaluates everalw idely-used longshore transport equations. The streamer trap measurement revealed an exponential distribution of the suspended sediment flux with vertical mixing decreasing in the onshore direction. A continuous time series of the longshore suspended sediment flux across the surf zone was obtained by combining the streamer trap measurements with data collected using surf zone instruments. Comparison of the suspended longshore flux with the total longshore flux derived from the dispersal of the sand tracer indicated that the relative contribution of the suspendedlo ad to the total load was at least 59 %. The movement of sandt racer on four different beaches demonstrated that nearshore sediments were transported obliquely across the surf zone, challenging our conventional view of dividing nearshore sediment transport into cross-shore and longshore components. Furthermore, tracer was found to move from the outer surf zone to the swash zone and vice versa, indicating a cross-shore sediment exchange. The contribution of the swash zone to the total longshore flux was estimated around 30-40 %. Despite large differences in the temporal and spatial scales of the measurement techniques, the littoral drift rates are comparable, suggesting a northward transport rate of 138,000-200,000 m3 year-1. Longshore sediment transport during sea breezes is mainly the result of a high longshore energy flux exerted by wind waves. This is accurately predicted by the equations of Inman and Bagnold (1963) and CERC (1984). The bimodal wave field, characteristic of Southwestern Australia, renders the Kamphuis (1991b) formula unsuitable in this instance.
475

Investigation of interfacial and bulk physical properties of hybrid perovskite-based devices / Etude des interfaces et des propriétés électro-optiques des dispositifs réalisés avec des perovskites hybrides

Chen, Yan-Fang 22 November 2016 (has links)
Les Pérovskites hybrides organique-inorganique (PHOIs) ont suscité d’intenses recherches au coursdes dernières années. Dans cette thèse, nous avons dans un premier temps mis au point les différentsprocessus de préparation des échantillons et réalisé une caractérisation complète des films parmicroscopie à force atomique, spectroscopie photo-électronique par rayons X, mesure du potentiel desurface par sonde de Kelvin et mesure de la mobilité des charges par temps de vol. La distribution despièges à l'interface PHOI/Au a été étudiée via des mesure J-V-L en fonction de la températurecombinées avec des simulations numériques. Les relaxations diélectriques dans les PHOIs, tels que lamigration des ions et l’orientation du dipôle du cation organique, ont été étudiés par spectroscopied’impédance en fonction de la température. Dans la dernière partie de cette thèse, nous présentons uneétude originale qui démontre un mouvement des protons du groupement ammonium des cationsorganiques à l’interface avec le PEDOT : PSS. / Hybrid-organic-inorganic perovskites (HOIPs) have provoked intense research over the recent years.In this thesis, we contribute to this investigation by first examining the results of different solutionpreparation processes, followed by characterizing the films using atomic force microscopy, X-raydiffraction, ultra-violet photoelectron spectroscopy, X-ray photoelectron spectroscopy, Kelvin probesurface potential measurement, and time-of-flight mobility measurement. The state distribution of theHOIP/Au interface was then studied by low temperature J–V–L measurement combined withnumerical simulation. In the process of these characterizations, it became clear that the dielectricrelaxations in HOIPs, such as ion migration and organic cation dipole orientation, play an importantrole in the material, and the next part of the thesis presents an analysis of these mechanisms with thehelp of temperature dependent impedance spectroscopy measurement. These studies built thefoundations for the final part of the thesis, where we investigated a so far elusive subject in HOIPs, themigration of protons
476

Korruption, ett svar på ojämlikhet? : En undersökande studie av Kenyas vatten- och sanitetssektor

Viding, Emmie January 2016 (has links)
No description available.
477

Evaluation of a Viscosity/Elasticity Assay (ReoRox®) for Assessment of Platelet Storage Lesion and Fibrinogen Dependent Coagulation

Guðjónsdóttir, Erla January 2016 (has links)
The impact storage has on function of platelet concentrates is not completely known, although some factors have been discovered and measures have been taken to counteract them, such as adding platelet additive solution. There are several methods for analysing platelet function. In this study, the aim was to analyse change of platelet function in platelet concentrates over time and to see what effect fibrogen has on the coagulation. A technique using free oscillation rheometry (FOR), ReoRox®, was used to analyse function in platelet concentrates, both over time and after addition of fibrinogen. The platelets were analyzed at a concentration of 800 x109 Ptl/L and activated with thrombin receptor antigen peptide (TRAP). For fibrinogen efect analysis, four different concentrations were used, 10 g/L, 2,25 g/L, 1,0 g/L and 0,1 g/L. The results showed no statistically significant change in the function over time. However an increase in elasticity and decrease in the decline of elasticity could be seen. While analysing the platelets with fibrinogen it showed that up to 2,25 g/L the aggregation increased, while it decreased significantly at 10 g/L. In conclusion, the platelet concentrates retained a good clotting function from day one to day seven of storage, while the clot became stronger and fibrinolysis decreased. Fibrinogen proved important for coagulation, however a too high concentration inhibits coagulation.
478

Failed States in International Relations / Zhroucené státy v mezinárodních vztazích

Čepilová, Barbora January 2009 (has links)
The aim of the work Failed States in International Relations is the examination of this phenomenon regarding the terminological discrepancy, causes of the state fragility, security and social aspects and the various attitudes from the side of the international communities. A special part is dealing with so called "successfully failed states" where despite the obvious non-functioning the state is able to survive due to the revenues from the natural resources. The ?ndings are represented on the case study of the Democratic Republic of the Congo - a country with huge potential but miserable performance by now.
479

Dynamique d'ions en pièges radiofréquences

Marciante, Mathieu 16 June 2011 (has links)
Les pièges radio-fréquences (rf) permettent de confiner des particules chargées (atomes ou molécules) dans un domaine restreint de l'espace. Alliés aux techniques de refroidissement laser, ils permettent l'étude et le contrôle de la matière au niveau atomique. Dans cette thèse sont présentés différents résultats obtenus au moyen de simulations numériques, utilisant la technique de la dynamique moléculaire. Cette thèse se compose de quatre parties. Une première partie rassemble les connaissances indispensables pour appréhender la dynamique des ions en pièges rf. La deuxième partie présente les résultats d'une étude sur l'influence du couplage coulombien sur le refroidissement laser Doppler d'un ensemble d'ions confinés en quadrupôle linéaire. La troisième partie s'intéresse aux propriétés des structures en anneau d'ions, obtenues à basse température au sein des multipôles linéaires d'ordres supérieurs au quadrupôle. Une dernière partie présente une proposition permettant l'obtention de sites supplémentaires où le champ rf s'annule dans les multipôles linéaires d'ordres supérieurs, offrant la possibilité d'obtenir des structures non soumises au forçage rf. / Radio-frequency (rf) traps allows one to confine charged particles (atoms or molecules) in a small region of space. These traps, with laser cooling technics, allows one to study and to control matter at the atomic level.In this thesis are shown different results obtained by numerical simulations using molecular dynamics technics. This thesis is formed of four parts. A first part introduce the necessary knowledge to comprehend the ion dynamics in rf traps. The second part present the results from a study on the influence of coulomb coupling on the doppler cooling of trapped ions in a linear quadrupole rf trap. The third part is a study of the properties of ring structures of ions, obtained for low temperatures in linear higher order rf traps. A last part of the thesis is a proposal allowing one to obtain additional rf field-free regions in linear higher order rf traps.
480

Vnější ekonomická rovnováha zemí jižního křídla eurozóny v kontextu světové ekonomické krize. / External Balance of Southern European Countries within the Context of the Global Economic Crisis.

Rakouský, Tomáš January 2013 (has links)
This diploma thesis focuses on changes in the external balance of Portugal, Italy, Greece and Spain in the period of financial and economic crisis after 2008. The theoretical framework is based on an exact definition of external balance, ultimately as neither surplus nor deficit of a relevant balance in terms of balance of payments. Potential impacts of monetary and fiscal policies on the external balance are described there as well, using the IS-LM-BP model. The second part of the thesis, which employs this theory, is mainly based on an analysis of relevant balances of payments of the aforementioned countries, focusing on their external balance in the period before as well as during the economic crisis. The aim of the analysis is to identify the main causes of external imbalance in the Southern European countries and to find out whether these played a key role as a trigger and accelerator in their recession after 2008. Specific changes during the crisis identified in balances of payments will also be depicted in the IS-LM-BP model. Leading to the conclusion, the outcomes of a correlation analysis are used as well, looking into causal relationships between specific balance of payments variables on the one hand, and macroeconomic variables on the other. A minor part also deals with the role played in this context by the TARGET2 payment system and answers the question to which extent this system took part in the elimination of the external imbalance of the Southern European countries during the crisis.

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