• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 126
  • 114
  • 53
  • 22
  • 22
  • 14
  • 5
  • 5
  • 4
  • 4
  • 2
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 450
  • 40
  • 39
  • 32
  • 30
  • 27
  • 26
  • 26
  • 26
  • 26
  • 26
  • 24
  • 24
  • 24
  • 22
  • 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.
321

An iterative analytical design framework for the optimal designing of an off-grid renewable energy based hybrid smart micro-grid : a case study in a remote area - Jordan

Halawani, Mohanad January 2015 (has links)
Creative ways of utilising renewable energy sources in electricity generation especially in remote areas and particularly in countries depending on imported energy, while increasing energy security and reducing cost of such isolated off-grid systems, is becoming an urgently needed necessity for the effective strategic planning of Energy Systems. The aim of this research project was to design and implement a new decision support framework for the optimal design of hybrid micro grids considering different types of different technologies, where the design objective is to minimize the total cost of the hybrid micro grid while at the same time satisfying the required electric demand. Results of a comprehensive literature review, of existing analytical, decision support tools and literature on HPS, has identified the gaps and the necessary conceptual parts of an analytical decision support framework. As a result this research proposes and reports an Iterative Analytical Design Framework (IADF) and its implementation for the optimal design of an Off-grid renewable energy based hybrid smart micro-grid (OGREH-SμG) with intra and inter-grid (μG2μG & μG2G) synchronization capabilities and a novel storage technique. The modelling design and simulations were based on simulations conducted using HOMER Energy and MatLab/SIMULINK, Energy Planning and Design software platforms. The design, experimental proof of concept, verification and simulation of a new storage concept incorporating Hydrogen Peroxide (H2O2) fuel cell is also reported. The implementation of the smart components consisting Raspberry Pi that is devised and programmed for the semi-smart energy management framework (a novel control strategy, including synchronization capabilities) of the OGREH-SμG are also detailed and reported. The hybrid μG was designed and implemented as a case study for the Bayir/Jordan area. This research has provided an alternative decision support tool to solve Renewable Energy Integration for the optimal number, type and size of components to configure the hybrid μG. In addition this research has formulated and reported a linear cost function to mathematically verify computer based simulations and fine tune the solutions in the iterative framework and concluded that such solutions converge to a correct optimal approximation when considering the properties of the problem. As a result of this investigation it has been demonstrated that, the implemented and reported OGREH-SμG design incorporates wind and sun powered generation complemented with batteries, two fuel cell units and a diesel generator is a unique approach to Utilizing indigenous renewable energy with a capability of being able to synchronize with other μ-grids is the most effective and optimal way of electrifying developing countries with fewer resources in a sustainable way, with minimum impact on the environment while also achieving reductions in GHG. The dissertation concludes with suggested extensions to this work in the future.
322

Geometrie izolovaných horizontů / Geometry of isolated horizons

Flandera, Aleš January 2016 (has links)
While the formalism of isolated horizons is known for some time, only quite recently the near horizon solution of Einstein's equations has been found in the Bondi-like coordinates by Krishnan in 2012. In this framework, the space-time is regarded as the characteristic initial value problem with the initial data given on the horizon and another null hypersurface. It is not clear, however, what ini- tial data reproduce the simplest physically relevant black hole solution, namely that of Kerr-Newman which describes stationary, axisymmetric black hole with charge. Moreover, Krishnan's construction employs the non-twisting null geodesic congruence and the tetrad which is parallelly propagated along this congruence. While the existence of such tetrad can be easily established in general, its explicit form can be very difficult to find and, in fact it has not been provided for the Kerr-Newman metric. The goal of this thesis was to fill this gap and provide a full description of the Kerr-Newman metric in the framework of isolated horizons. In the theoretical part of the thesis we review the spinor and Newman-Penrose formalism, basic geometry of isolated horizons and then present our results. Thesis is complemented by several appendices.
323

Mesure de la production des photons isolés dans les collisions p-p à √s=7 Tev avec le détecteur ALICE / Isolated photon production measurement in p-p collisions at √s= 7 TeV with the ALICE detector

Mas, Alexis 13 December 2013 (has links)
La production de photons de grande impulsion transverse lors des collisions proton-proton (p-p), est décrite par la chromodynamique quantique perturbative (pQCD). Parmi ces photons, ceux issus directement d’un processus partonique énergétique (appelés photons directs) sont particulièrement intéressants car leur mesure permet de tester précisément les prédictions de la pQCD et offre la possibilité de mieux contraindre les fonctions de structure du proton. Ce travail de thèse a pour objectif l’étude et la mesure des photons directs produits dans les collisions p-p à 7 TeV avec le détecteur ALICE. Le calorimètre électromagnétique d’ALICE (EMCal), est utilisé pour réaliser cette mesure qui s’appuie notamment sur l’utilisation d’une procédure d’isolement permettant de réduire le bruit de fond provenant des autres modes de production (fragmentation, décroissance). Les aspects relatifs à la qualité des données dans EMCal, à l’identification des photons, mais aussi ceux liés à la correction du spectre ou encore à sa normalisation sont mis en avant. Finalement, la première section efficace de photons isolés mesurée dans les collisions p-p à 7 TeV avec le détecteur ALICE est présentée et comparée avec les prédictions théoriques avant d’être mise en regard avec les résultats issus des autres grandes expériences du LHC. / The high transverse momentum photon production inproton-proton collisions (p-p) is described by perturbativequantum chromodynamics (pQCD). Among thesephotons, those produced directly by an energetic partonicinteraction (called direct photons) are of great interestsince their measurement allows to test pQCDpredictions and it allows also the constraint of protonstructure functions. The work of this thesis aims atstudying and measuring direct photons produced in p-pcollisions at 7 TeV with the ALICE detector. The ALICEelectromagnetic calorimeter (EMCal) is used to achievethis measurement which is based on an isolation procedurethat allows to reduce background coming fromother photon production modes (fragmentation, decay).Multiple aspects like EMCal data quality, photon identificationas well as spectrum correction and its normalizationare highlighted. Finally, the first isolated promptphoton cross-section measured with ALICE detector ispresented, compared to theoretical predictions and tothe last results from other LHC experiments.
324

Technique de perfusion pulmonaire isolée de chimiothérapie chez le porc / Isolated lung perfusion with chemotherapy in a pig model

Pagès, Pierre-Benoît 03 July 2014 (has links)
Introduction : La perfusion pulmonaire isolée (PPI) est une technique expérimentale dont l’objectif est d’administrer de fortes doses de chimiothérapie dans le poumon sans effets secondaires systémiques. Cette thèse s’est déroulée en trois étapes : première étape, déterminer in vitro la chimiothérapie la plus efficace en 30 minutes sur les cellules de cancers colo-rectaux (CCR). Deuxième étape, mettre au point la technique de PPI chez le porc. Troisième étape, mener une étude d’escalade de dose de chimiothérapie chez le porc en PPI.Méthodes : Première étape, des tests de cytotoxicité in vitro ont été menés sur un panel de cellules d’adénocarcinome colique humain avec les drogues de chimiothérapie les plus efficaces dans les essais cliniques. Deuxième étape, des porcs étaient traités par perfusion de chimiothérapie dans le poumon gauche isolé de la circulation générale pendant 30 minutes puis maintenus en vie pendant un mois. Troisième étape, les doses de chimiothérapie injectés étaient augmentées par palier jusqu’à obtenir une toxicité aigüe ou le décès des animaux.Résultats : La gemcitabine (GEM) fut la drogue ayant la plus grande efficacité anti-tumorale pour un traitement de 30 min. La PPI de GEM permit d’obtenir des concentrations élevées de GEM dans le parenchyme pulmonaire et la survie des animaux pendant un mois. Il n’existait pas de fuites systémiques de GEM. L’augmentation des doses de GEM permis de déterminer la dose maximale toxique à 320 mg et la toxicité limitant la dose à 640 mg. Conclusions : La technique de PPI avec la GEM est une technique sûre et reproductible permettant d’obtenir de fortes concentrations de GEM dans le parenchyme pulmonaire. / Introduction: The isolated lung perfusion (ILP) is an experimental technique which main objective is to deliver high dose of cytotoxic agent to the lung tissue without systemic exposure. The thesis took place in three stages: first stage, setting in vitro the chemotherapy the most efficient against colorectal cancer (CCR) cells in 30 min. Second stage, develop the ILP technique in a pig model. Third stage, lead a dose escalation study with chemotherapy by ILP.Methods: First stage, efficacy of various cytotoxic molecules against a panel of human CCR cell lines was tested in vitro after a 30-minute exposure. Second stage, pigs were treated with chemotherapy delivered by ILP during 30 minutes and kept alive during a month. Third stage, chemotherapy doses were increase in order to obtain acute toxicity or death of animals.Results: Gemcitabine (GEM) was the most efficient drug against CCR cells in 30 minutes. ILP with GEM permit to maintain high concentration in the lung parenchyma and pigs survival during one month. No systemic leaks were detected. Dose increase of GEM conduct to determine the maximal tolerated dose of GEM by ILP to 320 mg. Conclusions: ILP with GEM is a safety and reproducible technique allowing high GEM concentrations in the lung tissue.
325

Micropartículas produzidas por gelificação iônica recobertas com gelatina de peixe e isolado proteico de soja / Microparticles produced by ionic gelation coated with fish gelatin and isolated soy protein

Costa, Bianca Souza da, 1990- 24 August 2018 (has links)
Orientador: Carlos Raimundo Ferreira Grosso / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-24T10:13:53Z (GMT). No. of bitstreams: 1 Costa_BiancaSouzada_M.pdf: 3645103 bytes, checksum: ee9884c2d54163da7814b0ea032a53c5 (MD5) Previous issue date: 2014 / Resumo: O objetivo deste trabalho foi produzir partículas de pectina e alginato por gelificação iônica, com posterior recobrimento com isolado proteico de soja (IPS), gelatina de pele de tilápia (GPT) e com a mistura dessas duas proteínas (IPS:GPT), avaliando suas características físico-químicas e seu comportamento frente a diferentes tratamentos. No estudo preliminar foram analisadas as condições que promovessem a carga elétrica livre que otimizassem a interação entre os polissacarídeos e proteínas, formando complexos insolúveis. A partir desses ensaios foram estabelecidas as seguintes proporções de polissacarídeo: proteína e valores de pH: 1:2 em pH4 para recobrimento com gelatina de pele de tilápia, e 1:0,75 em pH3 para interação com o isolado proteico de soja e para a mistura das duas proteínas. Foram testados 4 níveis de proteína em solução ( 1, 2, 4 e 8 %) para recobrimento das partículas de pectina e alginato. As partículas obtidas foram caracterizadas pelo teor de umidade, conteúdo proteico adsorvido e pela sua morfologia. A partir deste estudo preliminar foi selecionada a concentração de 8% de proteína em solução, devido à produção de partículas com alto teor proteico. Estas partículas foram avaliadas com relação à sua estabilidade frente a variações de pH, diferentes concentrações de NaCl e sob simulação das condições gastrointestinais in vitro. Utilizando a concentração de 8% de proteína em solução foram obtidos altos valores de adsorção proteica, resultando no percentual de proteína de 61,87%, 47,61% e 52,06% para as partículas recobertas com GPT, IPS e IPS:GPT, respectivamente. A variação de pH e das concentrações de sal influenciaram na solubilidade da camada proteica, apresentando uma maior solubilidade em condições de extrema acidez (pH 1) e a medida em que aumentava a concentração de sal. Nas faixas de pH (1 a 7) e nas concentrações de NaCl (0 a 584 mM) estudadas, independente do valor da solubilidade proteica obtida, todas as partículas permaneceram íntegras. No ensaio gastroentérico in vitro, as partículas de pectina e alginato (PEC:ALGPart) sem recobrimento e as recobertas com gelatina de pele de tilápia (GPTPart) foram resistentes as condições gástricas e entéricas, permanecendo íntegras. As partículas recobertas com isolado proteico de soja (IPSPart) e com a mistura de proteínas (IPS:GPTPart), foram resistentes às condições gástricas, porém desintegraram-se em meio intestinal, liberando o material encapsulado / Abstract: The aim of this work was to produce particles of pectin and alginate by ionic gelation with subsequent coating with isolated soy protein (IPS), tilapia skin gelatin (GPT), and a mixture of these two proteins (IPS:GPT), evaluating their physico-chemical characteristics and behavior to different treatments. In the preliminary study, the conditions that promote the balance of free electrical charge due the interaction between polysaccharides and proteins were analyzed. From these tests the following proportions of polysaccharide:protein and pH values were established: 1:2 at pH 4 for covering with tilapia skin gelatin, and 1:0.75 at pH3 for interaction with the isolated soybean protein and mixing of the two proteins. Four protein levels were tested (1, 2, 4 and 8%) in solutions for coating the particles of pectin and alginate. The particles obtained were characterized by moisture content, adsorbed protein content and their morphology. From this preliminary study it was selected the concentration of 8% protein solution, due to the production of particles with high protein content. These particles were evaluated for their stability against pH changes, different concentrations of NaCl and simulation under the simulated gastrointestinal conditions. Using a concentration of 8% protein solution high levels of protein adsorption were obtained, resulting in percentage of protein adsorbed of 61.87%, 47.61% and 52.06% for the coated particles GPT, IPS and IPS: GPT, respectively. The variation of pH and salt concentrations influence the solubility of the protein layer having a higher solubility in conditions of extreme acidity (pH 1) and the extent to which increased salt concentration. In the pH ranges and concentrations of NaCl studied, regardless of the amount of protein solubility obtained, all the particles remained intact. In the gastrointestinal assay, pectin and alginate particles (PEC: ALGPart) uncoated and coated particles with tilapia skin gelatin (GPTPart) were resistant to the gastric and enteric conditions, remaining intact. The coated particles with isolated soy protein (IPSPart) and the protein mixture (IPS:GPTPart) were resistant to gastric conditions, but disintegrated in the intestinal environment, releasing the encapsulated material / Mestrado / Nutrição Experimental e de Alimentos / Mestra em Alimentos e Nutrição
326

A supressão da sucessão tributária e trabalhista na alienação da unidade produtiva isolada sob o prisma da preservação da empresa / The suppression of the succession of tax and labor contingencies on the sale of the isolated productive unit

Bento, Simone 27 November 2013 (has links)
Submitted by Nadir Basilio (nadirsb@uninove.br) on 2016-05-13T18:58:35Z No. of bitstreams: 1 Simone Bento.pdf: 606535 bytes, checksum: f03b97169d6e2bdbf4270cbfa10989b7 (MD5) / Made available in DSpace on 2016-05-13T18:58:35Z (GMT). No. of bitstreams: 1 Simone Bento.pdf: 606535 bytes, checksum: f03b97169d6e2bdbf4270cbfa10989b7 (MD5) Previous issue date: 2013-11-27 / The suppression of the succession of tax and labor contingencies on the sale of the isolated productive unit, a new rule established under Brazilian legal system through the Law Nº 11.101/2005 is a subject that carries out several doubts related to the bankruptcy and corporate reorganization. The main principle that rules the interpretation of the Reorganization and Bankruptcy Law is the maintenance of the corporation. This principle shall guide many questions that arise from the termination of the succession of tax and labor matters, when the purchase of the isolated productive unit takes place. This expression, for the very first time used in Brazilian legislation, brings several consequences related to the judicial sale of goods, regarding labor and tax obligation, bringing responsibility to the debtor submitted to the bankruptcy or corporate reorganization in view of the one who acquires the “establishment” and intends to maintain its corporate activities. This paper will deal with such consequences. / A supressão da sucessão tributária e trabalhista na alienação da unidade produtiva isolada, novidade introduzida no sistema positivo brasileiro pela Lei nº 11.101/2005, é tema que suscita múltiplas dúvidas quando aplicada à falência e à recuperação judicial. O princípio fundamental que informa a exegese da Lei de Recuperação de Empresas e Falência é a preservação da empresa. Este princípio deve iluminar a solução das diversas questões que a abolição da sucessão tributária e trabalhista faz surgir, quando realizada a alienação judicial de “unidade produtiva isolada”. Referida expressão vernacular, inédita no direito brasileiro, traz várias consequências derivadas da arrematação judicial de bens, no que concerne às obrigações fiscais e trabalhistas, que oneram o devedor submetido ao regime de falência ou recuperação judicial em face do arrematante que, ao adquirir o “estabelecimento”, pretenda a manutenção da atividade empresarial da unidade adquirida. Sobre essas consequências versa o trabalho em questão.
327

Teachers' Prefered Timing of Form Focused Instruction : A Study of Grade 4 - 6 English Teachers' Preference for Isolated- and Integrated FFI in Swedish Compulsory School

Backlund, Johannes January 2020 (has links)
Abstract  This study examined grade 4-6 English teachers’ preferred approach regarding the timing of grammatical instruction, developed and distinguished by Spada and Lightbown (2008) as isolated and integrated form-focused instruction (FFI). Both isolated FFI and integrated FFI are described as taking place in primarily meaning-based communicative classrooms. They differ in that isolated FFI takes place separately from communicative activities, while integrated FFI occurs during communicative activities. Using this theoretical distinction, Valeo and Spada (2016) developed teacher and learner questionnaires. The teacher questionnaire, along with observations, was used in the current study to investigate the views of teachers in the context of Swedish compulsory school. Quantitative and qualitative analyses of the questionnaire and observation data shows a preference for integrated FFI across all grades (grade 4, grade 5 and grade 6). At the same time, many teachers expressed the value of isolated FFI. The views of the teacher in this study align with previous research claiming that isolated and integrated FFI should not be mutually exclusive. Consistent with Valeo and Spada (2016), the teachers of this study pointed out that context, individual pupils and teacher beliefs may have an impact on decisions regarding the timing of grammatical instruction.
328

Mesure de la production de photons isolés dans les collisions proton-proton et proton-plomb au LHC avec l’expérience ALICE / Measurement of the isolated photon production in proton-proton and proton-lead collisions at the LHC with the ALICE experiment

Masson, Erwann 28 October 2019 (has links)
Dans le cadre du Modèle Standard de la physique des particules, les constituants élémentaires de la matière identifiés à ce jour sont les quarks et les gluons, génériquement appelés partons et soumis à l'interaction forte, décrite par la chromodynamique quantique (QCD). Si les partons sont confinés dans les hadrons sous des conditions normales de température et de densité, l'existence d'un état déconfiné, le plasma de quarks et de gluons (QGP), a été prédite par la QCD pour des conditions thermodynamiques extrêmes. Cet état de la matière peut être atteint dans le cadre de collisions d'ions lourds ultrarelativistes telles qu'en produit le grand collisionneur de hadrons du CERN (LHC), et sondé à l'aide de multiples observables auxquelles peut accéder l'expérience ALICE en particulier. Les photons prompts, issus de processus partoniques de haute énergie, constituent à ce titre une sonde privilégiée de la matière hadronique. Insensibles à l'interaction forte, ils peuvent traverser le milieu déconfiné en conservant les informations primaires d'une collision et représentent ainsi une référence précieuse a priori non affectée par le QGP. Ces photons peuvent être identifiés à l'aide de techniques de calorimétrie électromagnétique et d'isolement. Dans le cadre de cette thèse de doctorat, la production de photons isolés a été mesurée dans des collisions proton-proton et proton-plomb avec l'expérience ALICE. Les résultats obtenus sont compatibles avec des prédictions de QCD, y compris dans un régime cinématique inexploré jusqu'alors par cette observable. / In the Standard Model of particle physics, elementary constituents of matter identified to date are quarks and gluons, generically called partons and obeying the strong interaction described by quantum chromodynamics (QCD). While partons are confined in hadrons under standard temperature and density conditions, the existence of a deconfined state, quark-gluon plasma (QGP), has been predicted by QCD for extreme thermodynamic conditions. This state of matter can be reached in ultrarelativistic heavy-ion collisions such as produced at the CERN Large Hadron Collider (LHC) and can be probed with many observables accessible to the ALICE experiment in particular. Prompt photons, emitted by high-energy partonic processes, constitute a key probe of hadronic matter. Insensitive to the strong interaction they can traverse the deconfined medium preserving primary information about a collision, and thus represent a valuable reference not affected by QGP a priori. These photons can be identified with electromagnetic calorimetry and isolation techniques. Within this doctoral thesis, the isolated photon production has been measured in proton-proton and proton-lead collisions with the ALICE experiment. The results are in agreement with QCD predictions, including in a kinematic range unexplored by this observable thus far.
329

Mejoramiento de la reducción del desplazamiento de la base en estructuras aisladas tomando en cuenta el periodo creciente en los últimos 20 años utilizando el concepto de transmisibilidad / Improvement of base motion reduction in isolated structures considering the increased period in the last 20 years using transmissibility concept

Lazaro Bardales, Carlos Fernando, Mendez Neciosup, Daniel Fernando 23 December 2020 (has links)
En esta investigación se plantea una nueva metodología de diseño con el objetivo de obtener una mejora adicional basada en el concepto de transmisibilidad para la reducción del desplazamiento absoluto en la base aislada de una estructura. El incremento del periodo de diseño en los últimos años potencia el método propuesto basado en el concepto de transmisibilidad. Un edificio de 10 pisos es propuesto para esta investigación. Los resultados demuestran una reducción considerable en el desplazamiento de la base aislada cuando está sometida a sismos de gran magnitud. / In this research, a new design methodology based on the concept of transmissibility is proposed for the reduction of the absolute displacement in the isolated base of a structure. An increase in the design period in the last years favors the proposed method based on the transmissibility concept. A 10-story building is proposed for this research. The results show a considerable reduction in the displacement of the isolated base when it is subjected to earthquakes of great magnitude / Trabajo de investigación
330

Generation Control in Small IsolatedPower Systems

Haji Miragha, Amirhossein January 2005 (has links)
This thesis is concerned with the generation control in small isolated power systems consisting of inverter interfaced generation systems. First the components of an individual distributed generation system (DGS) as well as the corresponding control schemes for active and reactive power flow are discussed and implemented. Then the contribution of multiple DGS to meet the requirement of the loads in both gridconnected and island operations are discussed. Having evaluated the performance of each developed model such as voltage source inverter, PQ and PV controlled as well as reference DGS, the impact of voltage degradation on power load control in isolated systems is analyzed. Finally a new method for generation control in a small power system based on power sharing between multiple DGS with voltage degradation consideration as the last alternative for sustaining the system is proposed and implemented.-11D

Page generated in 0.036 seconds