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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
741

Computational Investigations of Biomolecular Systems and Comparison with Experiments in Various Environmental Conditions

KHABIRI, Morteza January 2011 (has links)
Computational methods were used to study two different types of biological systems. The first study is related to the effect of three different organic solvents (formamide, acetone and isopropanol) on the structure and behavior of three globular proteins. These enzymes belong to the haloalkane dehalogenase family: DhaA, LinB, and DbjA. Moreover, the effect of mutation in the presence of DMSO was also investigated in two variants of DhaA; DhaA57 (L95V+A172V) and DhaA80 (Thr148Leu+Gly171Gln+Ala172Val+Cys176Phe). The simulation results showed that except for DhaA80, organic solvents entered the active site and influence its hydration. Not only the active site but also the enzyme?s hydration shell is influenced by organic molecules. The results showed that the water molecules are stripped out from the enzyme surfaces. It seems that the dual nature of organic molecules makes them favorable to solvate the enzymes. Radial Distribution Function (RDF) of the different parts of each organic molecule reveals that the behavior of each organic solvent in the vicinity of hydrophobic surfaces is similar to their behavior at the air-water interface. Structural analysis of root-mean-square-deviations (RMSD) and B-factors reveals that the flexibility of the enzymes decreased in the presence of most organic solvents, mainly in the CAP domain. Changes of other structural properties like radius of gyration and total solvent accessible surface areas are minimal. DbjA exists as a dimer and is more influenced by organic molecules. They penetrate to the amino acid network between monomers and influence their motion. The second study is the interaction of voltage-gated potassium channel Kv1.3 wild type and its mutants (Kv1.3_V388C, Kv1.3_V388C_H399T) with scorpion toxin (ChTX). Since there is no structure for Kv1.3, 94% sequence identity with Kv1.2 structure was used to make a homology model based on the Kv1.2 structure. MD structural analyses reveal that mutation of V388C changes the stability of selectivity filter by interrupting the amino acid network interactions behind the selectivity filter. The interaction of ChTX is also affected by the single mutant. ChTX is able to block wild type and double mutant channels but cannot occlude the pore entirely. Introducing the second point mutation H399T in the pore region reverts the structural changes back to the wild type. These results are entirely consistent with experimental results. Additionally, the binding energy of ChTX with the wild type mKv1.3 was investigated by the potential of mean force method, in the presence and absence of KCl solution. The results both in experiment and simulation show that, even though the unbinding process and dissociation rate is changing in the present of K+ ions, the binding energy is independent of K+ concentration. All together, the combination of computer simulations together with experiments provides new knowledge about channel-toxin interactions which could be helpful for drug design.
742

Teorie relaxace a přenosu energie v otevřených kvantových systémech / Theory of Relaxation and Energy Transfer in Open Quantum Systems

Olšina, Jan January 2014 (has links)
The work summarizes basic theory of relaxation, energy transfer and decoher- ence in photosynthetic molecular aggregates described as open quantum systems and basic theory of third order coherent non-linear spectroscopy. The work presents two methods for calculation of photo-induced dynamics of molecular aggregates. The methods relax certain approximations of the theories commonly used to model the relaxation and energy transfer in the molecular systems on the sub-picosecond time scale. The first theory derived in the formalism of para- metric projection operators accounts for correlations in a second-order non-linear response-function that are usually neglected in the formalism of master equations. The second theory represents stochastic model of exact dynamics via the cumulant expansion. The work also presents an analysis of importance of the secular and the Markov approximations in the description of dynamics derived in the second-order perturbation theory in the system-bath coupling with emphasis on the excitonic coherence lifetime.
743

Problémy se stravováním v MŠ / Eating problems in kindergarten

BICANOVÁ, Martina January 2015 (has links)
This thesis deals with nutrition of preschool children. It concentrates on the issue of eating in nursery schools. The theoretical part contains characteristics of a preschool child development and information on the basic components of nutrition and its importance to the human body. I mentioned the influence of dietary habits on the healthy development of the child population and analysed the negative factors that could adversely affect this development. The practical part includes directed interviews with staff of kindergartens in district Prachatice and comparison between current diets and diets before 1989 in these institutions. The intention was to find differences between these diets. With the change in the political system new possibilities opened up. School canteens can experiment with new recipes, diets include new healthy foods.
744

Data collection of mobile sensor networks by drones / Collecte de données de réseaux de capteurs mobiles par drones

Ma, Xiaoyan 06 November 2017 (has links)
La collecte de données par des réseaux de capteurs autonomes mobiles peut être couplée à l’utilisation de drones qui constituent une solution de backahauling facilement déployable à faible coût. Ces moyens de collecte peuvent servir lors de l’organisation d’évènements temporaires (sportifs ou culturels) ou encore pour mener des opérations dans des terrains difficiles d’accès ou hostiles. L’objectif de cette thèse est de proposer des solutions efficaces pour la communication à la fois entre capteurs mobiles au sol et sur la liaison bord-sol. A ces fins, nous nous intéressons à l’ordonnancement des communications, au routage et au contrôle de l’accès sur la liaison capteurs/drone, le collecteur mobile. Nous proposons une architecture répondant aux contraintes du réseau. Les principales sont l’intermittence des liens et donc le manque de connexité pour lesquelles des solutions adaptées aux réseaux tolérants aux délais sont adoptées. Vu la limitation des opportunités de communication avec le drone et la variation importante du débit physique, nous avons proposés des solutions d’ordonnancement qui tiennent compte à la fois des durées de contact que du débit physique. Le routage opportuniste est également fondé sur ces deux critères à la fois pour la sélection des nœuds relais que pour la gestion des files d’attente. Nous avons souhaité limiter l’overhead et proposer des solutions efficaces et équitables entre capteurs mobiles au sol. Les solutions proposées ont montré leur supériorité par rapport aux solutions d’ordonnancement et de routage classiques. Nous avons enfin, proposé une méthode d’accès combinant un accès aléatoire avec contention ainsi qu’un accès avec réservation tenant compte des critères précédemment cités. Cette solution flexible permet à un réseau de capteurs mobiles denses de se rapprocher des performances obtenues dans un mode oracle. Les solutions proposées peuvent être mises en œuvre et appliquées dans différents contextes applicatifs pour lesquels les nœuds au sol sont mobiles ou aisément adaptées au cas où les nœuds sont statiques. / Data collection by autonomous mobile sensor arrays can be coupled with the use of drones which provide a low-cost, easily deployable backhauling solution. These means of collection can be used to organize temporary events (sporting or cultural) or to carry out operations in difficult or hostile terrain. The aim of this thesis is to propose effective solutions for communication between both mobile sensors on the ground and on the edge-to-ground link. For this purpose, we are interested in scheduling communications, routing and access control on the sensor / drone link, the mobile collector. We propose an architecture that meets the constraints of the network. The main ones are the intermittence of the links and therefore the lack of connectivity for which solutions adapted to the networks tolerant to the deadlines are adopted. Given the limited opportunities for communication with the drone and the significant variation in the physical data rate, we proposed scheduling solutions that take account of both the contact time and the physical flow rate. Opportunistic routing is also based on these two criteria both for the selection of relay nodes and for the management of queues. We wanted to limit the overhead and propose efficient and fair solutions between mobile sensors on the ground. The proposed solutions have proved superior to conventional scheduling and routing solutions. Finally, we proposed a method of access combining a random access with contention as well as an access with reservation taking into account the aforementioned criteria. This flexible solution allows a network of dense mobile sensors to get closer to the performance obtained in an oracle mode. The proposed solutions can be implemented and applied in different application contexts for which the ground nodes are mobile or easily adapted to the case where the nodes are static.
745

Vznik, provoz a další perspektiva využití vodního díla Lipno / Establishment, operation and further perspective of the hydro-electric plant Lipno

HOMMER, Jan January 2013 (has links)
The thesis contains essential information on the methods and possibilities of using water power. The first part deals with the history of water works, and introduction to basic physics of energy conversion. Further research is made available sources of information on the history, technology, power generation and design of hydropower Lipno I and II, with mention of unrealized project pumping plant Lipno III. The conclusion evaluates the defined objectives and creates a short summary.
746

Vstup české firmy na ukrajinský trh. / Entrance of Czech company into the Ukrainian market.

RIECHYN, Maksym January 2013 (has links)
The main goal of this Diploma thesis is to find the most suitable form of an entry of the Czech company into the Ukrainian market. In the theoretical part, I focus on the forms of an entry into the foreign markets. In the practical part I present the Czech company Green Energy Machine Product, Ltd., doing analysis of companys surroundings, SWOT analysis and portfolio analysis. Based on the information I chosed the most suitable form of an entry and proposed implementation of the entry into the Ukrainian market.
747

Dopady výpadku elektrické energie ve velkých potravinářských podnicích v Jihočeském kraji / Impacts of a power outage in great food - processing companies in South Bohemia county

HÁSKOVÁ, Michaela January 2014 (has links)
Indispensability of electricity in all areas of life, including industry, requires enterprises to be prepared for possible power outages, which would minimize impacts on the population. The aim of this thesis titled "Impacts of a power outage in great food - processing companies in the South Bohemia county" is to analyze possible impacts of power cuts in the awareness system of large food enterprises and to assess the effects it would have on the protection of the population when power outage occurs. To obtain the data for the thesis, I used a qualitative research in the form of structured interviews with employees of five large food enterprises, who are responsible for the given area. SWOT analyse was used to evaluate the interviews and a KARS method was used for the analysis of the most significant impacts of an electric power outage in the system of awareness of enterprises and in the protection of the population. The results of the research revealed a basic fact that electricity outage would mean an immediate interruption of production for the food enterprises in South Bohemia. None of the enterprises surveyed owns a standby electric power source, so the sustainability of the standby energy supply does not exist. This fact is alarming mainly from the point of view of the crisis management, because two of the surveyed enterprises are included in the Crises plan of South Bohemia and implement corresponding measures. An important factor influencing the current state of food enterprises awareness for electricity outage is undoubtedly the fact that there is no legislation in the Czech Republic at the moment, which would impose an obligation for food enterprises to prepare for electric power outages. To increase the awareness of the food enterprises for electricity outage, for example in the form back up power sources, would require considerable investments. I hope that this thesis will serve not only as a study material, but also will be a subject of discussion for food enterprises, presenting a model for a case of electric power outage.
748

Energetická bilance povrchu krajiny v lesně-zemědělském povodí / Energy balance of landscape surface in forested and agricultural catchment

SCHNEEDÖRFLER, Marek January 2018 (has links)
This diploma thesis deals with the statistical evaluation of the energy balance of landscape surface and its other chosen specifications via remote sensing and ground meteorological features. The thesis also includes the mapping of the landscape cover and its influence on the microclimate in the given area. The Novohradské Mountains, specifically the catchment of Bedřichovsky creek became the model area for this type of research. As each group of Land Cover (forest, permanent of grass cover, arable land, buildings) appears right in the catchment of Bedřichovský potok, it is suitable to evaluate the energy balance right in there.
749

Pěstování vybraných druhů rostlin pro energetické využití

ŠVEC, Miroslav January 2018 (has links)
This diploma thesis on the topic "Cultivation of selected plant species for energy use" in the first chapters of the theoretical part deals with Czech and world energy. The chapters on renewable energy sources and the possibilities of using biomass for plants for energy purposes follow. The research also deals with grasslands as alternative energy sources with a focus on direct burning. The last chapters of the research are focused on the cultivation of selected energy crops, such as the Elymus elongatus grass (subspecies Ponticus, Szarvasi-1) and Miscanthus × giganteus. The practical part describes the establishment, nursing and harvesting of small-scale experiments of Szarvasi-1 grass and Miscanthus × giganteus grass varieties, which were cultivated on the premises of the University of South Bohemia in České Budějovice and were grown as energy crops for direct incineration. Experiments with the Szarvas-1 cultivation took place in three types of farming. The first variation was the so-called "extensive" form where the plants were not fertilized with any fertilizer. The second form of farming was the "intensive" variant, in which the fertilizer was fertilized with mineral fertilizers. The last variant labeled "digestate" was fertilized with organic fertilizer. Maloparcelian experiments with Miscanthus × giganteus were carried out only in one variation of cultivation than Szarvasi-1, "intensive". For both varieties of energy crops harvested in spring 2013 and for all cultivation variants, the yield potentials from the last five years of vegetation of these cultures were evaluated after a six-year vegetation period. The evaluated parameters were in particular the yields of fresh matter and dry matter in t ha-1, but also the average solids content in %. These results were recorded and compared with specialist literature. The results of the work show that Miscanthus × giganteus yields on average higher yields than Szarvasi-1, which surprisingly best responds to organic fertilizer fertilization.
750

Úroveň povědomí obyvatelstva o problematice rozsáhlých výpadků elektrické energie / The level of awareness of inhabitants about the problems of large-scale electrical power failures

HAJDAJOVÁ, Natálie January 2018 (has links)
The diploma thesis deals with large-scale electrical power failures, in other words about blackouts. The work is then divided into two sections. The theoretical part describes the (critical) infrastructure, which is undoubtedly part of the electrical energy, further introduces the reader to the electricity system of the Czech Republic and also with blackout as such. The last chapter analyzes some important outages in the world and in total of eight blackouts and trying to point out how technical defects, control errors or extreme weather manifestation can negatively affect the lives of each of us. In the practical part are mentioned two objectives. The first, main aim of the diploma thesis is to find out and assess the level of knowledge of inhabitants about the problems of large-scale electrical power failures, with a hypothesis claims that awareness of the population in selected municipalities with extended competence does not reach 80 %. The exploration is carried out on two municipalities with extended competence Uherské Hradiště and České Budějovice. Obtained data are then evaluated by a comparative approach. Based on the results of the research, remedies are being suggested, purpose of the remedies is to improve the system of informing the population about the subject matter. This is the second objective. According to the objectives and for the needs of my thesis, I used the method of collecting data in the form of a questionnaire survey which carries elements of quantitative research. The thesis and its results can serve as a study material which could be further used for other research. Also it may be inspired by considering how to improve the awareness of the inhabitants.

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