• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 47
  • 24
  • 12
  • 10
  • 9
  • 8
  • 6
  • 4
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 148
  • 23
  • 15
  • 12
  • 12
  • 11
  • 11
  • 11
  • 10
  • 9
  • 9
  • 8
  • 8
  • 8
  • 7
  • 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.
121

Avalia??o funcional e estrutural de um novo pept?deo antimicrobiano do escorpi?o Tityus stigmurus

Melo, Edinara Targino de 31 March 2014 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-02T23:14:28Z No. of bitstreams: 1 EdinaraTarginoDeMelo_DISSERT.pdf: 2062041 bytes, checksum: b2de2a9d0f47d751e6c33c3d69b984a7 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-03-04T23:26:34Z (GMT) No. of bitstreams: 1 EdinaraTarginoDeMelo_DISSERT.pdf: 2062041 bytes, checksum: b2de2a9d0f47d751e6c33c3d69b984a7 (MD5) / Made available in DSpace on 2016-03-04T23:26:34Z (GMT). No. of bitstreams: 1 EdinaraTarginoDeMelo_DISSERT.pdf: 2062041 bytes, checksum: b2de2a9d0f47d751e6c33c3d69b984a7 (MD5) Previous issue date: 2014-03-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / No Brasil, ? grande a incid?ncia de animais pe?onhentos, dentre os quais se destacam os escorpi?es por sua import?ncia m?dica, sendo sua pe?onha fonte de diversas subst?ncias qu?micas com atividades biol?gicas e farmacol?gicas ainda n?o compreendidas, incluindo diversos pept?deos bioativos. Pept?deos antimicrobianos (PAMs) s?o componentes do sistema imune de procariotos e eucariotos utilizados como primeira linha de defesa contra micro-organismos. No presente trabalho, foi caracterizado o primeiro PAM do escorpi?o Tityus stigmurus, nomeado Stigmurina, previamente identificado por meio do transcriptoma da gl?ndula de veneno desta esp?cie. As caracter?sticas da Stigmurina foram investigadas por modelagem computacional e constru??o de dendrograma. Al?m disso, as caracter?sticas estruturais da Stigmurina foram investigadas por dicro?smo circular em ?gua, em 2, 2, 2- trifluoethanol (TFE) e em dodecil sulfato de s?dio (SDS) e os modelos refinados por simula??es de din?mica molecular. Testes in vitro foram empregados para investigar a atividade antibacteriana, antif?ngica, hemol?tica e citot?xica do veneno bruto e da Stigmurina. Os resultados mostraram que a sequ?ncia selecionada codifica uma prote?na madura com 17 res?duos de amino?cidos e o dendrograma revela um caso de converg?ncia evolutiva. Os espectros de dicro?smo demonstraram flexibilidade conformacional, predominando estrutura estendida e ??folha, al?m de not?vel capacidade de renatura??o. A pe?onha bruta n?o apresentou atividade relevante nos testes antimicrobianos para as concentra??es testadas. No entanto, a Stigmurina mostrou um amplo espectro de atividade antibacteriana, com concentra??es inibit?rias m?nimas (CIMs) entre 31,25?g/mL a 250 ?g/mL para diferentes micro-organismos, enquanto que os resultados para a avalia??o da atividade hemol?tica nestas concentra??es foram baixas. Nos estudos de citotoxicidade, a pe?onha bruta foi incapaz de reduzir a viabilidade celular em c?lulas VERO E6, por?m sua toxicidade em c?lulas SiHa foi significativamente superior, correspondendo a uma IC50 de 3,6 ?g/mL. J? nos testes com a Stigmurina, as concentra??es capazes de reduzir a viabilidade celular das c?lulas VERO E6 e SiHa em 50% foram de 275,67 ?g/mL e 212,54 ?g/mL, respectivamente.Os resultados sugerem que a Stigmurina poder ser considerada como um potencial medicamento anti-infeccioso. / In Brazil, there is a high incidence of venomous animals. Among them, scorpions are highlighted by their medical importance, and for being their venom a source of several molecules with biological and pharmacological activity not yet fully understood, including several bioactive peptides. Antimicrobial peptides (AMPs) are components of the immune system in prokaryotes and eukaryotes, used in the first line of defense against microorganisms. In the present study, we characterized the first PAM previously identified through transcriptome of the venom gland of the scorpion Tityus stigmurus, named Stigmurin. The characteristics of Stigmurin were investigated by computational modeling and construction of dendrogram. In vitro tests investigated the antibacterial, antifungal, haemolytic and cytotoxic effects of crude venom and Stigmurin. In addition, the structural characteristics of Stigmurin were investigated by circular dochroism in water, 2, 2 , 2- trifluoethanol (TFE) and sodium dodecyl sulfate (SDS) and the models were refined by molecular dynamics simulations. The results showed that the selected sequence encodes a mature protein of 17 amino acid residues and the dendrogram reveals a case of convergent evolution. The crude venom showed no antimicrobial activity, however, Stigmurin exhibited a broad spectrum of antibacterial activity, with minimal inhibitory concentrations (MIC) ranging from 31.25 and 250 ?g/mL for different strains, while the hemolytic activity at these concentrations was low. In cytotoxicity studies, the crude venom was unable to reduce cell viability in VERO E6 cells; in contrast, its activity in SiHa cells was significantly higher, corresponding to IC50 of 3.6 ?g/mL. For Stigmurin the concentration sable to decrease cell viability of Vero E6 and SiHa cells in 50% were 275.67 ?g/mL and 212.54 ?g/mL, respectively. The dichroism spectra revealed the conformational flexibility, with predominating extended and ??sheet structures, as well as a remark able renaturation ability. The results suggest that Stigmurin could be considered as a potential antiinfective drug
122

Análise comparativa do escoamento de fluído em experimentos RTM utilizando aplicativos comerciais

Luz, Felipe Ferreira January 2011 (has links)
Este trabalho visa estudar o fluxo de um fluido em um meio poroso (fibroso) durante o processo de Moldagem por Transferência de Resina (RTM) utilizando e comparando dois softwares comerciais: o ANSYS CFX, software de simulação numérica CFD não-dedicado a RTM, e o PAM-RTM, software de simulação numérica dedicado a esta aplicação. Foram utilizados dados experimentais, empregando uma pré-forma de tecido (0/90) de fibra de vidro e que foi impregnada por um óleo vegetal em injeção radial de RTM. Diversos experimentos foram realizados variando-se a pressão de injeção e o teor volumétrico de fibras a fim de observar o efeito no comportamento do fluxo. Com estes dados, alimentou-se o ANSYS CFX e o PAM-RTM utilizando equações dos meios porosos conhecidas, e foram feitas análises numéricas de todos os casos experimentais. Resultados de permeabilidade, viscosidade do fluido, tempo de preenchimento do molde, campo de pressão, variação da fração volumétrica das fases presentes e vetor velocidade de fluxo são apresentados e analisados. Concluiu-se que há uma sólida relação entre o experimental e o simulado (erros inferiores a 10%), o software PAM-RTM possui menor erro do que o ANSYS CFX quando comparados aos resultados experimentais, mas este último apresenta maior versatilidade de análises. / This work aims to study the flow of fluid through a porous (fibrous) media that occurs during Resin Transfer Molding (RTM) of composite materials and to compare it with the numerical results obtained with two commercial simulation software, ANSYS CFX, a general-use CFD package, and PAM-RTM, which is dedicated to RTM modeling. Experimental data were produced using a glass-fiber cloth (0/90) perform, which was impregnated with a vegetable oil in an RTM radial infiltration. Several experiments were performed varying injection pressure and fiber volume content in order to observe their effect on the flow behavior. These data were input into ANSYS CFX and PAM-RTM using known porous media equations and they were used to model all experiments. Results of permeability, fluid viscosity, mold filling time, pressure field, variation of volume fraction of the phases and the flow velocity vector are presented and analyzed. An excellent correlation between experimental and simulated results was found (errors less than 10%), and PAM-RTM yielded smaller error than ANSYS CFX, but the latter allows greater flexibility.
123

Análise comparativa do escoamento de fluído em experimentos RTM utilizando aplicativos comerciais

Luz, Felipe Ferreira January 2011 (has links)
Este trabalho visa estudar o fluxo de um fluido em um meio poroso (fibroso) durante o processo de Moldagem por Transferência de Resina (RTM) utilizando e comparando dois softwares comerciais: o ANSYS CFX, software de simulação numérica CFD não-dedicado a RTM, e o PAM-RTM, software de simulação numérica dedicado a esta aplicação. Foram utilizados dados experimentais, empregando uma pré-forma de tecido (0/90) de fibra de vidro e que foi impregnada por um óleo vegetal em injeção radial de RTM. Diversos experimentos foram realizados variando-se a pressão de injeção e o teor volumétrico de fibras a fim de observar o efeito no comportamento do fluxo. Com estes dados, alimentou-se o ANSYS CFX e o PAM-RTM utilizando equações dos meios porosos conhecidas, e foram feitas análises numéricas de todos os casos experimentais. Resultados de permeabilidade, viscosidade do fluido, tempo de preenchimento do molde, campo de pressão, variação da fração volumétrica das fases presentes e vetor velocidade de fluxo são apresentados e analisados. Concluiu-se que há uma sólida relação entre o experimental e o simulado (erros inferiores a 10%), o software PAM-RTM possui menor erro do que o ANSYS CFX quando comparados aos resultados experimentais, mas este último apresenta maior versatilidade de análises. / This work aims to study the flow of fluid through a porous (fibrous) media that occurs during Resin Transfer Molding (RTM) of composite materials and to compare it with the numerical results obtained with two commercial simulation software, ANSYS CFX, a general-use CFD package, and PAM-RTM, which is dedicated to RTM modeling. Experimental data were produced using a glass-fiber cloth (0/90) perform, which was impregnated with a vegetable oil in an RTM radial infiltration. Several experiments were performed varying injection pressure and fiber volume content in order to observe their effect on the flow behavior. These data were input into ANSYS CFX and PAM-RTM using known porous media equations and they were used to model all experiments. Results of permeability, fluid viscosity, mold filling time, pressure field, variation of volume fraction of the phases and the flow velocity vector are presented and analyzed. An excellent correlation between experimental and simulated results was found (errors less than 10%), and PAM-RTM yielded smaller error than ANSYS CFX, but the latter allows greater flexibility.
124

Analog and Digital Approaches to UWB Narrowband Interference Cancellation

Omid, Abedi January 2012 (has links)
Ultra wide band (UWB) is an extremely promising wireless technology for researchers and industrials. One of the most interesting is its high data rate and fading robustness due to selective frequency fading. However, beside such advantages, UWB system performance is highly affected by existing narrowband interference (NBI), undesired UWB signals and tone/multi-tone noises. For this reason, research about NBI cancellation is still a challenge to improve the system performance vs. receiver complexity, power consumption, linearity, etc. In this work, the two major receiver sections, i.e., analog (radiofrequency or RF) and digital (digital signal processing or DSP), were considered and new techniques proposed to reduce circuit complexity and power consumption, while improving signal parameters. In the RF section, different multiband UWB low-noise amplifier key design parameters were investigated like circuit configuration, input matching and desired/undesired frequency band filtering, highlighting the most suitable filtering package for efficient UWB NBI cancellation. In the DSP section, due to pulse transmitter signals, different issues like modulation type and level, pulse variety, shape and color noise/tone noise assumptions, were addressed for efficient NBI cancelation. A comparison was performed in terms of bit-error rate, signal-to-interference ratio, signal-to-noise ratio, and channel capacity to highlight the most suitable parameters for efficient DSP design. The optimum number of filters that allows the filter bandwidth to be reduced by following the required low sampling rate and thus improving the system bit error rate was also investigated.
125

Návrh postupu výroby součástí pro váleček pásového dopravníku / Proposal of the manufacturing procedure for the parts of belt conveyor roller

Pavelek, Michal January 2011 (has links)
The project, which has been elaborated within the framework of Master's Degree in Manufacturing Technology (2303T002), processes a technology proposal for the production of stamped part čelo from DD14 material, with a thickness 4 mm, with production quantities of 100 000 pieces per year, in cooperation with the company UNIRON Ltd. Based on the literature study of deep drawing without thinning of the walls and calculations, production of the part of simple single-function drawing tools was proposed. The first three operations performed on a PYE 100 S/1 hydraulic press and the last calibration operation carried out on a LEK 250 eccentric press. The semi-finished product is blank with a diameter of 195 mm, produced in a simple cutting die. The cutting die is designed for both the material in the form of a sheet metal strip in coils and cut strips of metal sheet, which is associated with the use of two eccentric presses of the LEK 250 and LE 400C types. The proposed manufacturing process was simulated in the PAM-Stamp 2G software, in which the influence of the radius the functional parts of tools to change the thickness of the material is further simulated. The part of the project is a technical and economic evaluation, in which the price of one piece of the product and production quantity at which production becomes profitable was rated.
126

Insight into coral reef ecosystems: investigations into the application of acoustics to monitor coral reefs and how corallivorous fish respond to mass coral mortality.

Dimoff, Sean 05 February 2021 (has links)
Coral reefs around the world are threatened by a variety of sources, from localized impacts, including overfishing and coastal development, to global temperature increases and ocean acidification. Conserving these marine biodiversity havens requires both global and local action informed by scientific research. In this thesis, I use data collected from the coral reefs around Kiritimati atoll (Republic of Kiribati) in the central equatorial Pacific, first to assess the applicability of two common metrics used in passive underwater acoustic research, and second to examine the effects of a marine heatwave and local human disturbance on an assemblage of corallivorous fish. Using acoustic data recorded in 2017 and 2018 on reefs around Kiritimati, I assess how sound pressure level (SPL) and the acoustic complexity index (ACI) respond to changes in fish sounds in a low frequency band (160 Hz – 1 kHz) and snapping shrimp snaps in a high frequency band (1 kHz – 22 kHz). I found that while SPL was positively correlated with increases in fish sounds and snap density, changes in ACI were dependent upon the settings chosen for its calculation, with the density of snaps negatively correlated with ACI across all settings. These findings provide evidence that despite its quick and prolific adoption, acoustic metrics like ACI should be thoroughly field-tested and standardized before they are applied to new ecosystems like coral reefs. Next, using underwater visual censuses (UVCs) of reef fish assemblages, I quantified how two functional groups of corallivores, obligate and facultative, responded to a mass coral mortality event created by the 2015-2016 El Niño. Declines in abundance of both groups were largely driven by the response of coral-associated damselfishes, Plectroglyphidodon johnstonianus in the obligate group and Plectroglyphidodon dickii in the facultative group, to heat stress and subsequent coral mortality. I also observed a significant decline in the species richness of obligate corallivores, and a continued decline in the abundance of obligate corallivores three years after the mass coral mortality event. Additionally, facultative corallivore abundance increased with disturbance, although the effect was modulated by year, likely due to their more adaptable diets. Corallivore assemblage structure was also influenced by the heat stress event, recovery, and local human disturbance. These results detail how an entire corallivorous assemblage is impacted by a coral mortality event and incidentally provide a timeline for corallivore decline. Together, these results provide information about new ways of monitoring coral reefs, and the ways in which two components of the reef fish community, obligate and facultative corallivores, respond to a mass coral mortality event. / Graduate / 2022-01-15
127

Dimensions of Political Ideology on the Party Level in Morocco : A qualitative text analysis of the electoral manifestos of the Party of Justice and Development and the Party of Authenticity and Modernity before the 2016 elections

Nedal Khasawneh, Omran January 2022 (has links)
This thesis describes how the religious-secular, economic, and cultural dimensions come to expression in the electoral manifestos of two political parties in the 2016 elections in Morocco. The parties in question are the Islamist-oriented Party of Justice and Development (PJD) and the non-Islamist Party of Authenticity and Modernity (PAM), viewed as leading contenders and emerged as the two biggest parties in the same election year. This study applies a qualitative text analysis of the manifestos and shows that the parties differed on two dimensions of three. The parties showed the most significant difference under the religious-secular dimension, where PJD supported increased religious influence on policymaking. In contrast, PAM kept itself neutral and neither supported nor opposed religious influence on state affairs. The next most significant difference was found under the cultural dimension. Both parties expressed support for gender equality, albeit PAM was more ambitious and proposed an amendment to the family law to equalize women with men regarding the right of the Moroccan woman to transfer her citizenship to her non-Moroccan husband. In contrast, PJD proposed extending maternity leave and fighting violence against women. The slightest differences were found under the economic dimension. Surprisingly, both parties advocated for almost the same free-market and redistribution policies even though they represented two opposing blocks in the Moroccan party system.
128

Propuesta de transformación digital y mejora del gobierno de TI para el organismo estatal encargado de la identificación de los peruanos / Proposal of digital transformation and improvement of the IT government for the state agency responsible for the identification of Peruvians

Prado Quintana, Elvis David, Valdivieso Alvarado, Wiliam Eduardo 09 November 2019 (has links)
La presente tesis tiene como objetivo la elaboración de una Propuesta de Transformación Digital sobre el proceso de registro de identificación, la cual toma como base la mejora de los procesos de TI a través de los lineamientos de COBIT PAM para el organismo estatal encargado de la identificación de los peruanos. Para lograr este propósito se identificarán los objetivos estratégicos de la institución y su relación con los procesos de TI. Posteriormente, se determinarán los procesos que serán revisados bajo el Modelo de Evaluación de Procesos de COBIT 5. A partir de los resultados obtenidos se elaborará un plan de mejora cuyo objetivo será cumplir con los criterios necesarios para lograr que los procesos de TI estén consolidados. Finalmente, teniendo un buen soporte de TI, se hará una propuesta de transformación digital para el proceso de registro de identificación que con la ayuda de un asistente virtual, basado en inteligencia artificial, brindará un servicio omnicanal a los ciudadanos. / This thesis aims to develop a Digital Transformation Proposal on the identification registration process, which is based on the improvement of IT processes through the COBIT PAM guidelines for the state body responsible for identification of the Peruvians. To achieve this purpose, the institution's strategic objectives and its relationship with IT processes will be identified. Subsequently, the processes that will be reviewed under the COBIT Process Evaluation Model 5 will be determined. Based on the results obtained, an improvement plan will be developed whose objective will be to meet the criteria necessary to ensure that the IT processes are consolidated. Finally, having a good IT support, a digital transformation proposal will be made for the identification registration process that, with the help of a virtual assistant, based on artificial intelligence, will provide an omnichannel service to citizens. / Tesis
129

Podpora pro autentizaci pomocí otisků prstu / Support for Fingerprint Authentication

Bartoň, Jaroslav January 2009 (has links)
The goal of the thesis is the finger-print authentication support within the Linux operating system and the K Desktop Environment (KDE). Theoretical part of the thesis firstly explains main IT security terms and ways to proof the identity. Secondly it describes biometric systems and types of processed biometric characteristics. Lastly the features of finger-prints, their markants as well as types of scanners used in scanning the finger-prints and ways to analyze the scanned material have been elaborated. Practical solution part of the thesis develops and establishes finger-print management application and plugin for KDM graphics login manager.
130

Pam Gems: Rethinking Her Life and the Impact of Her Plays on British Stage

Najar Daronkolae, Esmaeil 27 July 2018 (has links)
No description available.

Page generated in 0.7016 seconds