• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 407
  • 170
  • 80
  • 71
  • 34
  • 30
  • 12
  • 10
  • 7
  • 7
  • 6
  • 6
  • 5
  • 3
  • 3
  • Tagged with
  • 960
  • 233
  • 223
  • 145
  • 134
  • 89
  • 86
  • 80
  • 79
  • 78
  • 78
  • 77
  • 77
  • 71
  • 69
  • 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.
641

Vliv velikosti matrice na průběh lisovacího procesu / The influence of the die size on the compaction process

Marcinková, Nikola January 2016 (has links)
Charles University in Prague, Faculty of Pharmacy in Hradci Králové Department of: Department of Pharmaceutical Technology Consultant: Mgr. Pavel Ondrejček, Ph.D. Student: Nikola Marcinková Title of Thesis: The influence of the die size on the compaction process This diploma thesis is focused on exploration the influence of the die size on the compaction process. That was evaluated by parameters of three-exponential equation. Compressibility was studied by using force-displacement record. In this work was also observed an effect of die size on the tensile strength. In processing the experimental part of this work were used four different model materials. Microcrystalline cellulose and dicalcium phosphate are used as model fillers and theophylline and paracetamol as model active substances. Compaction of these materials was carried out in dies of size 7 mm, 9 mm, 11 mm, 13 mm and 15 mm. The results of the work showed that the die size significantly affects all parameters force-displacement record. With the growing size of the die there was a reduction of energy parameters. Most of the compaction parameters were statistically influenced. Increasing die size caused reducing volume reduction and energy consumption and increased speed of volume reduction at the stage of pre- compression and elastic...
642

Enregistrement molécularie de changements d'usage des sols et de pressions anthropiques : l'exemple d'un étang piscicole (Lansquenet, Lorraine) / Molecular record of land use changes and anthropogenic pressure : example of a fish pond (Lansquenet, Lorraine)

Bertrand, Olivia 12 October 2012 (has links)
Les séries sédimentaires, prélevées dans les écosystèmes aquatiques terrestres, constituent des enregistrements ou des archives de l'état d'un système à un instant donné du passé et de son évolution en relation avec la variabilité environnementale naturelle et anthropique. Dans le cadre de cette thèse, l'enregistrement sédimentaire d'un étang piscicole, a été étudié suivant une approche pluridisciplinaire. En particulier, la caractérisation à l'échelle moléculaire et macromoléculaire de la matière organique des sédiments de l'étang de Lansquenet a permis de reconstruire l'histoire de son bassin versant. Basé sur l'utilisation de biomarqueurs et de rapports moléculaires (rapport terrigène/aquatique : TAR(HC), C29/C27(ST), aquatic/macrophyte proxy : Paq, pérylène, syringyle/vanillyle, cinnamyle/vanillyle, acide/aldéhyde des unités syringyles et vanillyle), ce travail a permis d'appréhender, à l'échelle d'un bassin versant, les variations pluriséculaires des sources de la matière organique (terrestre et/ou aquatique, naturelle et/ou anthropique), mais aussi des conditions de dépôt et de préservation, induits par les changements d'usage des sols et les impacts anthropiques. La confrontation de ces résultats avec les données sédimentologiques, minéralogiques et palynologiques a permis de valider la pertinence et la sensibilité de ces biomarqueurs par rapport aux variations environnementales et paléoenvironnementales. Cette étude met ainsi en évidence la succession des usages de ce site depuis un milieu marécageux jusqu'à la création et l'exploitation de l'étang piscicole jalonnée d'épisodes d'assec / The sedimentary series, collected in terrestrial and aquatic ecosystems, constitute records or archives of the state of a system at a given moment of the past and relate its evolution in relation to natural disturbances and anthropogenic pressure. In the following manuscript, the sedimentary record of a fish pond has been studied using a multidisciplinary approach. In particular, the characterization at the molecular and macromolecular scale of the organic matter in sediments of the pond Lansquenet allowed to reconstruct the history of its watershed. On the basis of biomarkers and molecular ratios (terrestrial to aquatic ratio: TAR(HC), C29/C27(ST), aquatic/macrophyte proxy: Paq, perylene, syringyl/vanillyl, cinnamyl/vanillyl, acid/aldehyde of syringyl and vanillyl units), this work has enabled us to understand, at the scale of a watershed, the changes in organic matter origins (terrestrial and/or aquatic, natural and/or anthropogenic) over a period of several centuries. Moreover, the results unraveled the depositional conditions as well as preservation conditions in the sedimentary profile, directly influenced by land use and human activities. The confrontation of organic geochemical data with sedimentological, mineralogical and palynological data was a real benefit and validated the use of a series of organic compounds as relevant and sensitive biomarkers regarding environmental and paleoenvironmental modifications. This study highlighted thus the succession of use of the Lansquenet site from a swampy area to the settlement of a fish pond punctuated by drier periods
643

Hodnocení lisovatelnosti směsí pelet a mikrokrystalické celulosy / The evaluation of compressibility of the mixtures of pellets and microcrystalline cellulose

Berková, Simona January 2016 (has links)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Consultant: Mgr. Pavel Ondrejček, Ph.D. Student: Simona Berková Title of Thesis: The evaluation of compressibility of the mixtures pellets and microcrystalline cellulose This thesis is focused on the evaluation of powdered microcrystalline cellulose, pellets and mixtures thereof. Comprecel 102 was used as powdered microcrystalline cellulose. The used pellets were commercially available pellets Cellets 100 made of microcrystalline cellulose. The flow properties of used materials and their mixtures were evaluated by using the angle of repose, flow through orifice and Hausner ratio methods. Further the compressibility was evaluated using the force-displacement record. For the evaluation of compaction proces the three exponential compaction was used. Finally the radial tablet strength and tablet friability was tested. The results showed, that the flow properties improved with an increasing amount of pellets in mixture. I tis due to higher bulk and tapped density and also narrower particle size distribution, smoother surface and the regular shape of used pellets. The parameters of the force-displacement method showed different compressibility of used tabletting mixtures. The evaluation of...
644

Porovnání viskoelastických vlastností směsí laktosy a různých typů kluzných látek s využitím testu stresové relaxace. / A comparison of viscoelastic properties of mixtures of lactose and different lubricants using the stress relaxation test.

Přeučilová, Michaela January 2016 (has links)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical technology Consultant: Mgr. Petra Svačinová, Ph.D. Student: Michaela Přeučilová Title of Thesis: A comparison of viscoelastic properties of mixtures of lactose and different lubricants using the stress relaxation test This diploma thesis deals with viscoelastic properties of pharmaceutical excipients and tensile strength of tablets made of these excipients. Theoretical part is dedicated to description of lactose and lubricants, further the tablets compressibility and compression energy profile are described. The end of theoretical part deals with the stress relaxation test, with evaluation methods and the stress relaxation test influence on lactose tablets with different types of lubricants as well. The experimental part deals with the evaluation of the viscoelastic properties of two types of lactose and their mixtures with different types of lubricants at concentration of 1%. These characteristics were evaluated by stress relaxation test. All tablets were compressed by compression forces of 13 kN and 15 kN with dwell time 180 seconds. The study was about differences between two types of lactose, effect of lubricants and effect of two different compression forces on parameters of elasticity A1 -A3 and...
645

Vliv délky prodlevy na parametry testu stresové relaxace u laktosy a hydrogenfosforečnanu vápenatého. / The influence of the dwell time on the parameters of the stress relaxation test for lactose and calcium hydrogen phosphate.

Straková, Markéta January 2016 (has links)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical technology Consultant: Mgr. Petra Svačinová, Ph.D. Student: Straková Markéta Title of Thesis: The influence of dwell time on the parameters of the stress relaxation test for lactose and calcium hydrogen phosphate The aim of this thesis is to find out viscoelastic properties of pharmaceutical excipients and to evaluate the tensile strength of tablets made of them. The theoretical part describes used materials, these are lactose, calcium hydrogen phosphate and magnesium stearate. The thesis also deals with the stress relaxation test, its evaluation and usage. Tensile strength, calculation and various factors that affect tensile strength are described in the text. The experimental part deals with viscoelastic properties of used materials and their mixtures with lubricant using the stress relaxation test. Different dwell times (60 s, 120 s, 180 s, 240 s, 300 s, 360 s, 420 s, 480 s, 540 s, 600 s) were used for individual measurements. The relation between elasticity parameters (A1, A2, A3) and plasticity parameters (P1, P2, P3) depending on the dwell time was investigated. As for calcium hydrogen phosphate, the dwell time 180 - 240 seconds was found as the most appropriate. As for lactose, the optimum dwell...
646

Studium procesu lisování pelet z mikrokrystalické celulosy. / A study of the compaction process for the pellets made of microcrystalline cellulose.

Trpělková, Žofie January 2016 (has links)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Consultant: Mgr. Pavel Ondrejček, Ph.D. Student: Žofie Trpělková Title: A study of a compaction process of microcrystalline cellulose pellets This work is aimed at the comparison of two types of microcrystalline cellulose (Comprecel 102 a Avicel PH-200) with two types of pellets made of microcrystalline cellulose (Cellets 100 a Cellets 200). Important properties for the compaction into tablets were analyzed in these materials. The particle size distribution, the content of moisture, the bulk and tapped density, the flowability, the angle of repose and the Hausner ratio were evaluated. Furthermore, the compaction process was described by using the force displacement method and the three-exponential equation. Finally, the radial strength and the friability of tablets prepared by using two different compaction forces were evaluated. The results proved that both types of pellets have much better flow properties than powdered microcrystalline celluloses. This is primarily caused by the narrow particle size distribution, higher bulk and tapped density and the significantly smoother surface of pellets. Better flow properties of the pellets also influenced the parameters of the force-displacement...
647

Vliv délky prodlevy na parametry testu stresové relaxace u mikrokrystalické celulosy a škrobu. / The influence of the dwell time on the parameters of the stress relaxation test for microcrystalline cellulose and starch.

Hamplová, Kateřina January 2016 (has links)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical technology Consultant: Mgr. Svačinová Petra, Ph.D. Student: Hamplová Kateřina Title of Thesis: The influence of the dwell time on the parameters of the stress relaxation test for microcrystalline cellulose and starch. This thesis is focused on the viscoelastic properties of pharmaceutical excipients and the tensile strength of tablets. The theoretical part describes used materials. Microcrystalline cellulose and starch were used as fillers and magnesium stearate at concentration of 1% was used as lubricant. The stress relaxation test and its evaluation and utilization not only in pharmacy is described as well as the tensile strength of tablets. The experimental part deals with the viscoelastic properties of used materials and their mixtures with lubricant. These properties were evaluated using the stress relaxation test. At maximum compression force of 10 kN the length of dwell time was changed (60 s, 120 s, 180 s, 240 s, 300 s, 360 s, 420 s, 480 s, 540 s, 600 s). For derived parameters of elasticity A1-3 and plasticity P1-3 the dependence on the length of dwell time was evaluated. Parameter A1 increases with increasing dwell time for all substances. For parameters A2, A3, the dependence on the dwell...
648

The long-term dynamics of soil organic carbon in the anthropogenic soils of Scotland's medieval urban landscape

Esiana, Benneth O. I. January 2015 (has links)
In an interdisciplinary study requiring the synergistic association of historical evidence and chemical and biochemical analyses, this thesis investigates the properties and characteristics of historically modified soils known as anthrosols. These soils, developed through the anthropogenic addition of high volumes of organic-rich municipal waste materials to land, including human and animal waste, as part of the waste management practices in medieval urban communities in Scotland at St Andrews, Roxburgh and Elgin, offer an insight to the state and dynamics of these organic material. Soil is one of the most sensitive environmental domains to transformation. These transformations are visible from the alterations to the physical and chemical properties of soil. Anthropogenic activities may leave behind signatures in the soil in the form of artefacts, ecofacts, elemental enrichment or depletion, enhancement in soil magnetic properties and organic matter content. In the historical dimension of this study, the observable features and measurable properties of soil profiles are exploited to reveal past organisation and functions of cultural landscapes by carefully studying the stratigraphic units of soil profile, and examining the association of each unit with settlement artefacts and soil properties. Through comparison with historical records of past events on the respective study sites, the relationship between the soils record of past human activities is observed through physical, chemical and biochemical properties. The historical record is used to assess if such evidence can be used reliably to develop the account of site use for the medieval burghs of Scotland. In the environmental aspect, investigation focuses on the physical and chemical conditions of these soils in terms of their carbon content, composition, residence time estimates and their role in global C cycle and terrestrial carbon budgeting. Past investigations of anthopogenically-deepened soils have been interpreted with respect to historical site use, however, the environmental implications of the resultant accumulated organic material or residue have not previously been considered in much detail. A particular novelty of this aspect of the project is that it is an in-depth examination of anthropogenic soils with known histories extending into the medieval period. This time-depth allows a new understanding of the processes and products of decomposition of known organic materials that were added to soil. The biophysicochemical data obtained from these soils such as their extant organic carbon content and variability with depth, the composition of the various carbon species that together constitute soil organic matter, and biological community and activity (microorganisms and enzymes) provides critical information on the relative recalcitrance, state of decomposition, and the mechanism of stabilisation of these materials in the soil.
649

Du système d'information clinique au système d'information épidémiologique : apport de l'intéropérabilité sémantique

Avillach, Paul 27 September 2011 (has links)
Les informations médicales recueillies dans le cadre du soin doivent être utilisables pour répondre à d’autres objectifs plus collectifs. Dans ce contexte de réutilisation des données d’un système d’information clinique pour de la recherche en épidémiologie, l’objectif de ce travail est d’étudier l’apport de l'intéropérabilité sémantique à travers un certain nombre de situations concrêtes que nous avons rencontrées et étudiées et qui illustrent la nature des problèmes de cohérence sémantiques liés au traitement des données médicales et de santé.La coexistence, à un moment donné, de plusieurs référentiels sémantiques ne doit pas être considéré comme un obstacle à l'interopérabilité. Des outils génériques peuvent être conçus et développés pour passer de façon transparente d'un composant à un autre avec aussi peu de perte d’information que possible. L’Unified Medical Language System (UMLS) est un de ses outils d’intégration sémantique. Son usage dans le cadre de ces travaux montre le caractère général de cette méthode et son potentiel pour résoudre cette classe de problèmes d’intéropérabilité sémantique.La richesse de chacune des terminologies permet, lorsqu’elles sont associées dans un même référentiel sémantique pivot, d’enrichir l’ensemble des terminologies prises individuellement pour une meilleur représentation des connaissances.L’interopérabilité sémantique améliore la disponibilité et la qualité des données réutilisables pour des recherches en santé publique. Elle permet d’enrichir les données existantes. Elle fournit les moyens d'accéder à de nouvelles sources de données, agrégées de manière valide, permettant des analyses comparatives ou des analyses plus riches. / Medical information collected during clinical care must be re-used to address other more collective goals. In this context of re-using data from a clinical information system for epidemiological research, the objective of this work is to study the contribution of semantic interoperability across a number of practical situations we have met and discussed which illustrate the nature of semantic consistency problems associated with processing of medical data.Coexistence at a given time, of several semantic repositories should not be considered as an obstacle to interoperability. Generic tools can be designed and developed to move seamlessly from one component to another with as little loss of information as possible. The Unified Medical Language System (UMLS) is one of the semantic integration tools. Its use in this work shows the generality of this method and its potential for solving this class of semantic interoperability problems.The richness of each of the terminology can, when combined into a single pivot semantic repository, enrich the set of terminologies individually for a better representation of knowledge.Semantic interoperability improves the availability and quality of reusable data for public health research. It also enriches existing data. It provides access to new sources of data, aggregated in a valid manner, allowing benchmarking or richer analysis.
650

Med kameran som penna : Where is my home? Essäfilm och subjekt i rörelse / With your camera as your pen : Where is my home? Essay Film and subjects in motion

Carlsson Gras, Emelie January 2016 (has links)
Syftet med uppsatsen är att diskutera vilka funktioner dagboksberättandet i essäfilm skulle kunna fylla samt på vilket sätt dessa filmer reflekterar sin samtid. I uppsatsen kommer jag diskutera och identifiera olika funktioner med hjälp av relevant och teoretisk litteratur samt genom enstaka filmexempel. Om ny teknologi och tillgänglighet har öppnat upp gränserna för det privata och offentliga, kan essäfilmer, som för in det personliga och privata i det dokumentära, ses som ett uttryck för dessa uppluckrade gränsdragningar. Den digitala utvecklingen, vår samtid samt essäfilmens specifika möjligheter är områden som den här texten huvudsakligen berör.

Page generated in 0.039 seconds