• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 59
  • 13
  • 9
  • 7
  • 6
  • 5
  • 3
  • 3
  • 3
  • 3
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 138
  • 22
  • 13
  • 12
  • 11
  • 10
  • 9
  • 9
  • 9
  • 9
  • 9
  • 8
  • 8
  • 8
  • 8
  • 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.
81

Interação entre fisiologia termal e balanço de água em Rhinella schneideri (Anura, Bufonidae) / Trading heat and hops for water: dehydration effects on locomotor performance, thermal limits, and thermoregulatory behavior of a terrestrial toad

Anderson, Rodolfo César de Oliveira [UNESP] 09 August 2017 (has links)
Submitted by Rodolfo César de Oliveira Anderson null (rco.anderson@gmail.com) on 2017-09-12T12:04:57Z No. of bitstreams: 1 Dissertação_final.pdf: 1603715 bytes, checksum: 0b40e4e5998ff7807dd5b93ea532c5fa (MD5) / Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-09-12T17:51:42Z (GMT) No. of bitstreams: 1 anderson_rco_me_rcla.pdf: 1603715 bytes, checksum: 0b40e4e5998ff7807dd5b93ea532c5fa (MD5) / Made available in DSpace on 2017-09-12T17:51:42Z (GMT). No. of bitstreams: 1 anderson_rco_me_rcla.pdf: 1603715 bytes, checksum: 0b40e4e5998ff7807dd5b93ea532c5fa (MD5) Previous issue date: 2017-08-09 / Devido à alta permeabilidade da pele e a ectotermia, anfíbios terrestres são confrontados por compromissos envolvendo o balanço de água e a regulação da temperatura corpórea. O modo como tais compromissos são acomodados, sobre uma extenção de temperaturas e estados de hidratação, influencia importantemente o comportamento e a ecologia desses animais. Nesse contexto, usando o anfíbio terrestre Rhinella schneideri como organismo modelo, os objetivos do presente estudo foram duplos. Primeiramente, nós determinamos como a sensibilidade termal de uma característica ecologicamente relevante – a locomoção – é afetada pela desidratação. Além disso, nós examinamos os efeitos dos mesmos níveis de desidratação na preferência termal e na tolerância termal. A medida que a desidratação se torna mais severa, as temperaturas ótimas para o desempenho locomotor diminuíram e a amplitude de temperaturas para um desempenho próximo ao máximo se estreitou. Semelhantemente, a desidratação foi acompanhada por uma diminuição da amplitude de tolerância termal. Tal declínio foi causado pelo aumento da temperatura crítica mínima e pela diminuição da temperatura crítica máxima, com este último mudando de modo mais acentuado. Em geral, nossos resultados mostram que os efeitos negativos da desidratação no desempenho comportamental e na tolerância termal são, ao menos parcialmente, amenizados pelo simultâneo ajuste na preferência termal. Nós discutimos algumas potenciais implicações dessa observação para a conservação dos anfíbios anuros. / Due to their highly permeable skin and ectothermy, terrestrial amphibians are challenged by compromises between water balance and body temperature regulation. The way in which such compromises are accommodated, under a range of temperatures and dehydration levels, impact importantly the behavior and ecology of amphibians. Thus, using the terrestrial toad Rhinella schneideri as a model organism, the goals of the present study were two-fold. First, we determined how the thermal sensitivity of a centrally relevant trait – locomotion – was affected by dehydration. Secondly, we examined the effects of the same levels of dehydration on thermal preference and thermal tolerance. As dehydration becomes more severe, the optimal temperature for locomotor performance was lowered and performance breadth narrower. Similarly, dehydration was accompanied by a decrease in the thermal tolerance range. Such a decrease was caused by both, an increase in the critical minimal temperature and a decrease in the thermal maximal temperature, with the latter changing more markedly. In general, our results show that the negative effects of dehydration on behavioral performance and thermal tolerance are, at least partially, counteracted by concurrent adjustments in thermal preference. We discuss some of the potential implications of this observation for the conservation of anuran amphibians.
82

Arquitetura do plano preferencial de recursos para o setor elétrico no planejamento integrado de recursos energéticos. / Architecture of preferential energy resource plan for electricity sector in integrated resources planning.

Flávio Minoru Maruyama 15 October 2013 (has links)
O objetivo deste trabalho é determinar e modelar a Arquitetura do Plano Preferencial Integrado de Recursos para o Setor Elétrico, no contexto do planejamento energético atual. O Plano Preferencial Integrado é uma coletânea sistêmica de recursos energéticos obtidos por meio de um processo integrado de planejamento, ao longo do tempo e da geografia, denominado Planejamento Integrado de Recursos Energéticos (PIR). Utilizam-se metodologias do Inventário Energoambiental, da Listagem e do Peneiramento de Recursos Energéticos, do Cômputo e Valoração de Recursos Energéticos, da Análise de Custos Completos, englobando custos internos e externos, da Previsão da Demanda e da Integração de Recursos, ponto em que efetivamente se inicia a construção do Plano. A validação do modelo é realizada no estudo de caso aplicado na Região Administrativa de Araçatuba, no oeste do estado de São Paulo, Brasil. Por fim, apresentam-se considerações sobre esse plano preferencial e estabelece-se a proposta de uma metodologia alternativa de planejamento energético para o setor elétrico, visando o desenvolvimento sustentável por meio de uma imbricação entre energia, meio ambiente e sociedade, com seu balanço equilibrado de importâncias. / The objective of the study is to define and model the Architecture of Integrated Energy Resources Preferential Plan for the Power Sector, in the context of current energy planning. The Integrated Energy Resources Preferential Plan is a systemic compilation of energy resources obtained through an integrated energy planning over the time and geography, called Integrated Resource Planning (IRP). The plan is developed using the methodology of Environmental and Energy Inventory; Listing and Drafting of Energy Resources; Calculation and Valuation of Energy Resources Full Potentials, Full Cost Analysis, Demand Forecasting and Resources Integration, after which the construction of plan effectively starts. The model validation is performed in the case study applied in Araçatuba Administrative Region, in the western state of São Paulo, Brazil. Finally, the IRP Preferred Plan is reviewed and a proposal for an alternative methodology for energy planning for the power sector is presented aiming at sustainable development through a complete overview among energy, environment and society, with its balanced importance.
83

Effects of the Object’s Mass and Distance on the Location of Preferred Critical Boundary, Discomfort, and Muscle Activation during a Seated Reaching Task

Petrovic, Milena 06 August 2012 (has links)
No description available.
84

Encoding and Decoding : Researching the controversy of Kamala Harris’ Vogue cover

Kristjansdottir, Selma January 2021 (has links)
The purpose of this research is to examine how visual communication can be interpreted in different ways and even in opposition to the creator’s intention, and to understand how different visual signs in images convey meaning to explain audience’s oppositional reading. Through a qualitative methodological approach, a semiotic comparative analysis of two covers of the fashion magazine Vogue featuring Kamala Harris will be carried out, a digital cover and a print cover. Theoretically, the analysis is grounded in postcolonialism, representation, and Stuart Hall’s encoding and decoding model of communication. The results suggest that there are signs in the photograph on Vogue’s print cover that can be interpreted from a postcolonial perspective, and both oppositional and preferred readings are discussed.
85

Evaluation of breeding practices and morphological characterisation of donkeys in three selected villages of the Blouberg Local Municipality, in the Limpopo Province, South Africa

Maswana, Masixole January 2022 (has links)
Thesis(M.Sc. (Animal Production)) -- University of Limpopo, 2022 / Donkeys continue to play a significant role in draught power activities for both rural and urban regions in underdeveloped countries, where they are commonly employed for transportation of goods and movement of people at extremely low prices. The study sought to determine donkey farmers' breeding practices as well as donkey morphological characterization in three villages such as Thorp, Archibalt and Genau of the Blouberg Local Municipality. A total of 21 donkey farmers and 74 donkeys were used to collect data. The following Morphological traits characterized were; Head length (HL), Ear length (EL), Neck length (NL), Chest width (CW), Back length (Bal), Body length (BoL), Hips width (HW), Umbilical circumference (UC), Back height (BH), Height at the rump (HR), Thoracic circumference (TC), Chest depth (CD), Withers Height (WH), Front leg length (FLL), Cannon circumference (CC), Cannon length (CL), Cannon height (CH) and Body weight (BW). Descriptive statistics, Chi-square tests, Analysis of variance (ANOVA), Pearson correlation, and Rank Index were used for data analysis. Education level of the farmers in the three villages was significantly different (p<0.05) with the majority of farmers having secondary education. There was no significant difference (p>0.05) amongst the villages on different reasons behind keeping donkeys. The results showed a significant difference (p<0.05) in inbreeding knowledge by the farmers amongst the three villages. The selection criteria used across the three villages were not significantly different (p>0.05). Rank and Indices in selection of male donkeys looked at body size (0.39), growth rate (0.19), Draught power performance (0.14), and for overall preference in female donkeys it was body size (0.26), twinning ability (0.23) and mothering ability (0.15). Body size and growth rate where the most important traits to donkey farmers. The coat colours were not significantly different (p>0.05). In all the eighteen measured traits, only four (BaL, HW, BH and FLL) showed a significant difference (p<0.05) among the three villages. BW in male donkeys was not significantly correlated (p>0.05) with HL, EL, NL, BaL, HW, FLL, CC, CH, CL but was positively correlated (p<0.05) with BoL (r = 0.34), UC (r = 0.35), TC (r = 0.33), CD (r = 0.31), CW (0.94), BH (r = 0.41), HR (0.60), and WH (r = 0.58). BW in female donkeys was not significantly correlated (p>0.05) with NL, BaL, TC, and CL but positively significant correlated (p<0.05) with HL, EL, BoL, HW, UC, FLL and CC CW, BH, HR, WH and CH with correlation coefficient values ranging from 0.34 to 0.75. The farmers had no breeding program in place the donkeys were allowed to mate on their own without designed breeding program. Selection of donkeys to be part of the heard was based on physical attributes, such length It was concluded that donkey farmers in Genau, Archibalt, and Thorp villages engaged in breeding practices that could be valuable in construction of a community-based breeding program.
86

Applied color processing

Zhang, Heng 29 November 2011 (has links)
The quality of a digital image pipeline relies greatly on its color reproduction which should at a minimum handle the color constancy, and the final judgment of the excellence of the pipeline is made through subjective observations by humans. This dissertation addresses a few topics surrounding the color processing of digital image pipelines from a practical point of view. Color processing fundamentals will be discussed in the beginning to form a background understanding for the topics that follow.A memory color assisted illuminant estimation algorithm is then introduced after a review of memory colors and some modeling techniques. Spectral sensitivity of the camera is required by many color constancy algorithms but such data is often not readily available. To tackle this problem, an alternative method to the spectral characterization for color constancy parameter calibration is proposed. Hue control in color reproduction can be of great importance especially when memory colors are concerned. A hue constrained matrix optimization algorithm is introduced to address this issue, followed by a psychophysical study to systematically arrive at a recommendation for the optimized preferred color reproduction. At the end, a color constancy algorithm for high dynamic range scenes observing multiple illuminants is proposed. / Graduation date: 2012
87

In-Shoe Plantar Pressure System To Investigate Ground Reaction Force Using Android Platform

Mostfa, Ahmed A. 01 January 2016 (has links)
Human footwear is not yet designed to optimally relieve pressure on the heel of the foot. Proper foot pressure assessment requires personal training and measurements by specialized machinery. This research aims to investigate and hypothesize about Preferred Transition Speed (PTS) and to classify the gait phase of explicit variances in walking patterns between different subjects. An in-shoe wearable pressure system using Android application was developed to investigate walking patterns and collect data on Activities of Daily Living (ADL). In-shoe circuitry used Flexi-Force A201 sensors placed at three major areas: heel contact, 1st metatarsal, and 5th metatarsal with a PIC16F688 microcontroller and Bluetooth module. This method provides a low-cost instantaneous solution to both wear and records plantar foot simultaneously. Data acquisition used internal local memory to store pressure logs for offline data analysis. Data processing used the perpendicular slope to determine peak pressure and time of index. Statistical analysis can utilize to discover foot deformity. The empirical results in one subject showed weak linearity between normal and fast walk and a significant difference in body weight acceptance between normal and slow walk. In addition, T-test hypothesis testing between two healthy subjects, with , illustrated a significant difference in their Initial Contact pressure and no difference between their peak-to-peak time interval. Preferred Transition Speed versus VGRF was measured in 19 subjects. The experiments demonstrated that vertical GRF averagely increased 18.46% when the speed changed from 50% to 75% of PTS with STD 4.78. While VGRF increased 21.24% when the speed changed from 75% to 100% of PTS with STD 7.81. Finally, logistic regression between 12 healthy subjects demonstrated a good classification with 82.6% accuracy between partial foot bearing and their normal walk.
88

Deformation mechanisms and strain localization in the mafic continental lower crust

Degli Alessandrini, Giulia January 2018 (has links)
The rheology and strength of the lower crust play a key role in lithosphere dynamics, influencing the orogenic cycle and how plate tectonics work. Despite their geological importance, the processes that cause weakening of the lower crust and strain localization are still poorly understood. Through microstructural analysis of naturally deformed samples, this PhD aims to investigate how weakening and strain localization occurs in the mafic continental lower crust. Mafic granulites are analysed from two unrelated continental lower crustal shear zones which share comparable mineralogical assemblages and high-grade deformation conditions (T > 700 °C and P > 6 Kbar): the Seiland Igneous Province in northern Norway (case-study 1) and the Finero mafic complex in the Italian Southern Alps (case-study 2). Case-study 1 investigates a metagabbroic dyke embedded in a lower crustal metasedimentary shear zone undergoing partial melting. Shearing of the dyke was accompanied by infiltration of felsic melt from the adjacent partially molten metapelites. Findings of case-study 1 show that weakening of dry and strong mafic rocks can result from melt infiltration from nearby partially molten metasediments. The infiltrated melt triggers melt-rock reactions and nucleation of a fine-grained (< 10 µm average grain size) polyphase matrix. This fine-grained mixture deforms by diffusion creep, causing significant rheological weakening. Case-study 2 investigates a lower crustal shear zone in a compositionally-layered mafic complex made of amphibole-rich and amphibole-poor metagabbros. Findings of case-study 2 show that during prograde metamorphism (T > 800 °C), the presence of amphibole undergoing dehydration melting reactions is key to weakening and strain localization. Dehydration of amphibole generates fine-grained symplectic intergrowths of pyroxene + plagioclase. These reaction products form an interconnected network of fine-grained (< 20 µm average grain size) polyphase material that deforms by diffusion creep, causing strain partitioning and localization in amphibole-rich layers. Those layers without amphibole fail to produce an interconnected network of fine grained material. In this layers, plagioclase deforms by dislocation creep, and pyroxene by microfracturing and neocrystallization. Overall, this PhD research highlights that weakening and strain localization in the mafic lower crust is governed by high-T mineral and chemical reactions that drastically reduce grain size and trigger diffusion creep.
89

Déformation HP-HT des magmas siliceux : contraintes expérimentales sur l'évolution structurale et les transitions rhéologiques aux moyennes et fortes cristallinités / HP-HT deformation of silicic magmas : experimental constrains on the structural evolution and the rheological threshold at middle and high cristallinities

Picard, David 24 March 2009 (has links)
Le comportement rhéologique de suspensions magmatiques synthétiques hydratées a été expérimentalement étudié en déformation coaxiale et en torsion à haute température et haute pression à l’aide d’une presse de type Paterson. Les résultats obtenus illustrent l’influence de la fraction cristalline et de la forme des cristaux sur la rhéologie et le développement des Orientations Préférentielles de Forme (OPF) des particules au sein des suspensions magmatiques. La formation d’une charpente cristalline, associée à une forte hausse de la viscosité, intervient pour des fractions solides comprises entre fs = 0,20 et 0,38 en relation avec le développement de fabriques de type pénétratif. En augmentant la fraction solide (fs = 0,50), le développement d’une fabrique pénétrative, couplé à des bandes de cisaillement bordées de gradients de déformation, engendre un adoucissement de la réponse rhéologique et une hausse moins importante de la viscosité. Pour fs = 0,58, des bandes de cisaillement de type cassant sans gradient de déformation, recoupant une suspension non déformée, apparaissent et contrôlent le fort adoucissement de la réponse rhéologique. La viscosité de la suspension n’augmente plus alors que légèrement. Au-delà de cette fraction cristalline, les suspensions étudiées montrent une forte réduction de la taille et du rapport de forme des cristaux se traduisant par une stabilisation de la réponse rhéologique en fonction de la déformation. Aucune OPF n’a pu être déterminée et une quasistabilisation de la viscosité est observée (comportement mécanique de solide). Toutes les suspensions étudiées se caractérisent par un comportement rhéologique non-Newtonien de type rhéofluidifiant. La dépendance entre le comportement rhéologique des suspensions magmatiques et le développement des microstructures doit être intégrée dans la modélisation de la mécanique des suspensions magmatiques. / The rheological behaviour of synthetic hydrous magmatic suspensions has been experimentally investigated in compression and torsion at high temperatures and pressures in a Paterson press. The results illustrate the influence of the crystal fraction and of the shape of the crystals on the rheology and the Shape Preferred Orientation (SPO) of the particles. A solid particle network, associated with a strong increase of the viscosity, is generated between crystal fractions (fs) of 0.20 and 0.38, with the development of pervasive fabrics. With increasing the crystal fraction (fs = 0.50), shear bands bordered by symmetrical deformation gradients crosscut the pervasive fabric, resulting in a weakening in the rheological behaviour of the suspension. The increase of the viscosity with increasing cristallinity of the suspension becomes less important. At fs = 0.58, brittle shear bands without deformation gradients crosscut an undeformed suspension and lead to a strong weakening of the rheological behaviour which explains the small increase of the viscosity of the suspension with increasing crystal fraction. Above this crystal fraction, suspensions show a strong reduction of the crystal size and shape ratio. No SPO has been determined but the near-stabilisation of the viscosity, coupled with a stabilisation of the stress with strain, is consistent with a solid-like mechanical behaviour at these high crystallinities. All studied suspensions are characterized by a non-Newtonian, shear thinning rheological behaviour. Our results and, in particular, the dependence between the rheological behaviour and the development of crystal microstructures, need to be integrated in mechanical models of magmatic suspensions.
90

Emprego de sondas solvatocrômicas no estudo de solvatação em solventes puros, misturas de solventes e soluções micelares / Employment solvatochromic probes in the study of solvation in pure solvents, solvent mixtures and micellar solutions

Tada, Erika Batista 08 October 2004 (has links)
Neste trabalho, sondas solvatocrômicas foram empregadas no estudo da solvatação em solventes puros e misturas aquosas de solventes polares práticos e apráticos. A partir da polaridade de misturas aquosas de solventes orgânicos, determinou-se a concentração de água interfacial de micelas catiônicas. Finalmente, avaliou-se o efeito da polaridade e força iônica interfaciais de micelas catiônicas sobre a velocidade da reação entre p-nitrofenildifenilfosfato e o íon fluoreto. No estudo de misturas aquosas de solventes orgânicos, um novo modelo de solvatação preferencial foi elaborado, segundo o qual três espécies presentes em solução competem pela camada de solvatação da sonda: água, solvente orgânico e o \"complexo\" formado por uma molécula de água e outra de solvente orgânico (Solv-Água). Através deste modelo, analisou-se o efeito da temperatura e das propriedades das sondas e dos solventes orgânicos sobre o fenômeno da solvatação. Em soluções aquosas de micelas catiônicas, observou-se uma desidratação da interface em função do aumento do grupo hidrofílico do tensotativo e da mudança de geometria micelar de esférica para cilíndrica. Verificou-se que a velocidade da reação entre pnitrofenildifenilfosfato e fluoreto é pouco afetada pela interface micelar e pode ser reproduzida, na ausência de micelas, em soluções com mesma concentração de água e força iônica que as micelas. / Solvatochromic probes have been employed to study the polarity of pure solvents and binary mixtures of water with protic and aprotic polar solvents. From polarity data of aqueous organic mixtures, the concentration of interfacial water of cationic micelles has been determined. In aqueous solutions of cationic micelles, the dehydration of interfacial region has been observed as a result of increasing the volume of the surfactant head group and changing micellar geometry from spherical to cylindrical. Finally, the effect of interfacial polarity and ionic force on the rate of the reaction between 4-nitrophenyldiphenylphosphate and fluoride ion has been evaluated. In studying aqueous organic mixtures, a new preferential solvation model has been developed, that considers the competition between three species in solution for the probe micro-solvation shell: water, organic solvent and a 1:1 \"complex\" formed by water and organic solvent (Solv-Água). Based on this new model, the effect of temperature, as well as probe and organic solvent properties on solvation has been analyzed. It has been observed that the rate of the reaction between p-nitrophenyldiphenylphosphate and fluoride ion shows little dependence on the properties of interfacial region of cationic micelles and can be reproduced, in the absence of micelles, in solutions containing the same water concentration and ionic force as the micellar pseudo-phase.

Page generated in 0.219 seconds