• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 311
  • 272
  • 78
  • 69
  • 19
  • 14
  • 13
  • 10
  • 8
  • 8
  • 6
  • 6
  • 6
  • 4
  • 4
  • Tagged with
  • 942
  • 107
  • 103
  • 82
  • 64
  • 61
  • 53
  • 52
  • 49
  • 47
  • 41
  • 39
  • 39
  • 38
  • 37
  • 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.
731

A Marxist Reading Of Things Fall Apart In The Esl Classrom : Exploring Colonial Socio-economic Exploitation in the Nigerian Context

Nkalubo, Arthur E. January 2021 (has links)
This thesis aims to explore how a critical reading of the novel Things Fall Apart (1958) can provide valuable perspective for educators and students when examining socio-economic issues in  a colonial context in the ESL classroom. The main issues being analysed are how the novel reveals and explores socio-economic forms of exploitation under colonialism, and how a critical reading of the novel can be used in teaching to inform and persuade learners about social injustices. To show this, the essay examines the novel from a marxist perspective, and more specifically by drawing on the concept of primitive accumulation to understand and explain the changes brought about by the introduction of colonial rule. The changes in this context include the Igbo community's relation to land, its socio-economic and cultural aspects as well as the introduction of trade. The discussion and analysis of the novel centre on social injustices due to land expropriation, breakdown of traditional values and customs, and economic changes brought about by the arrival of Europeans in the context of colonialism. Expanding on this, the essay also reflects on the pedagogical implications of its arguments by showing how a critical reading of Things Fall Apart might provide an opportunity for teachers to underline issues of social injustice, material, and economic forms of exploitation under colonialism and beyond. This literary analysis also discusses and reflects on the practical challenges and possibilities of teaching such issues in the ESL classroom by using the concept of critical literacy.
732

Tepelné čerpadlo s akumulací / Heat pump with accumalation

Kohout, Jiří January 2017 (has links)
This diploma thesis deals with the assessment of SCOP of the heat pump installed in the selected building and with the determination of optimal size of accumulation which should help to heat pump work with higher temperature and higher SCOP. Annual savings of operating cost and return of investment from installation of accumulation tank are evaluated in this thesis. In the research part of this thesis are described the main components of heat pump, sources of low-potential heat and types of heat pump.
733

Vyhodnocení provozních dat tepelného čerpadla / Evaluation of heat pump operation data

Charvátová, Marie January 2019 (has links)
This diploma thesis deals with the issue of heat pumps as devices using low-potential heat of the surrounding environment for heating of buildings. In the theoretical part of the thesis there are described various types of these devices, the sources of low-potential heat and the possibilities of heat energy accumulation. The practical part of the thesis is focused on processing and evaluation of operational data of air/water heat pump used for heating of family house and assessment of importance of accumulation tank in heating system. Part of the thesis is also a proposal of optimization of heat pump control.
734

DC/DC měnič pro záložní zdroje / DC to DC inverter for backup power supplies

Eliáš, Marek January 2019 (has links)
This thesis deals with the design of a DC/DC converter designed for charging supercapacitors from the 36 V voltage source and consequent back transformation of supercapacitors voltage to the required output voltage. In the thesis the designs of decreasing and increasing DC/DC converters including schematics and calculations of individual components are presented and described. The calculations necessary for the supercapacitors to meet the 10Wh energy condition and the voltage balancer on the capacitors are given below. Completely designed equipment will be assembled and tested on supercapacitors with lower energy.
735

Akumulace elektrické energie pro zdroj s nestabilní produkcí / Accumulation of electricity for a source with unstable production

Petrenec, Jan January 2020 (has links)
This diploma thesis deals with possibilities of accumulation of electricity generated by renewable sources with unstable production. Several goals were set by an assignment of this thesis. Within a research, current trends of the accumulation are presented in detail on examples of specific representatives with their technical parameters and economic possibilities. Further, an unstable source of electricity – the wind farm of three power plants Multibrid 5000 with all its parameters and operational details is defined for purposes of individual designs of accumulation systems. Firstly, the detailed design of an advanced compressed air energy storage (A-CAES) is realized. It includes a thermodynamic calculation of chosen components, their partial technical solutions, a financial evaluation of investment and a determination of theoretical payback period. Furthermore, the design for accumulators Tesla Powerpack is realized. It contains a calculation of individual system parameters, a financial evaluation of investment and a determination of theoretical payback period. Last part of the thesis is dedicated to a comparison and an evaluation of the achieved results of both realized methods of the electricity accumulation. In the end, A-CAES is chosen as more perspective variation.
736

Sezónní akumulace využívající technologii power-to-gas / Seasonal accumulations using power-to-gas technology

Zavadil, Jan January 2020 (has links)
The diploma thesis is focusing on the seasonal energy storage in synthetic fuels and the Power to Gas system (P2G). The P2G enables the conversion of electrical energy in times of electricity surplus, for example by using the surplus from renewable energy sources to produce synthetic gas, particulary hydrogen and synthetic methane. The main focus is on the technical and economic assessment of P2G of the Gazela natural gas pipeline. Furthermore, it identifies the limits of production, transportation, and storage capacities of these synthetic gases. The technical analysis assumes the injection of hydrogen of a certain molar concentration, according to the four proposed scenarios, into the natural gas transmission system in the Gazela pipeline. The results have showen that an increase in the molar fraction of hydrogen in natural gas will cause problems in gas transport and will lead to an increase in the pressure losses, an increase in flow rate, and a decrease in the storage capacity of the pipeline. The economic analysis examines the use of P2G technology in Czech conditions. It demonstrates the amount of production costs for the production of 1 MWh of synthetic gas depending on the electricity price and the operating time of the production facility. The sensitivity analysis has shown that neither hydrogen nor synthetic methane is competitive next to cheap natural gas unless measures like an increased price of emission allowances or a carbon tax are taken.
737

Akumulace elektrické energie z obnovitelných zdrojů / Accumulation of electricity from renewable sources

Plíšek, Petr January 2021 (has links)
This diploma thesis deals with the issue of accumulation of electricity produced by renewable sources. The first part focuses on the description of possible ways of accumulation, especially with focus on those methods, that are suitable for renewable energy sources. The next part deals with the design of the accumulation energy in the compressed air for the selected photovoltaic power plant. The necessity of designing a particular method of energy storage, is also its technical and economic analysis, which is the content of the last part of the thesis.
738

Zpracování experimentálních dat v reálném čase / Experimental data processing in real time

Veselý, Petr January 2011 (has links)
The thesis completes the current programming equipment for experimental measurement of isolated animal heart signals. It adds a block providing the pre-processing of the signals. The signals measured are the elektrogram (EG) and the action potential (AP). The origin of individual signals, the measuring method and the possibilities of noise elimination are dealt with in the theoretical part of the thesis. The practical part describes the pre-processing block securing the noise elimination during the AP. It uses accumulative methods of averaging the corresponding time periods of the AP. Based on the results of measuring the signal to noise ratio, the thesis suggests the most appropriate accumulative methods and their variables. In order for the chosen accumulative methods to work well, it is important to divide the AP process into sectors of corresponding shape (repeats). The connection between the EG and AP processes is used to determine the beginning and end of the sectors. These points are identified by the detection of R and T wave peaks in the EG. To detect the R and T waves, the thesis uses methods based on wavelet transform. The efficiency and accuracy of detection methods is verified by test EG signals with hand-marked R and T wave peaks.
739

Vytápění rodinného domu s využitím tepelného čerpadla / Heat pump for domestic heating

Koubková, Lucie January 2008 (has links)
This diploma thesis is about using heat pump (HP) to gain energy. The theoretical part contains introduction, historical development of HP, principle of function, description of individual components, working cycle of heat pump and sources of lowpotencial energy and accordingly possible types of heat pumps. The practical part is devoted to proposal of appropriate type of heat pump for heating and warming of tap water for family house and economical evaluation of this solution.
740

Akumulace elektrické energie z obnovitelných zdrojů / Accumulation of electricity from renewable sources

Dědek, Dušan January 2008 (has links)
This work is specialized on problems accumulation electricity power from renewable sources and production electricity power from renewable sources for select object. First part describes renewable sources and their use in our conditions. Second part is specialized on accumulators specific for renewable sources. Third part compare to production electricity power from photovoltaic power station and windy power station and their combination for select object. Further accumulation these select sources. Final fourth part describe about their comparison from position how of technical so economic.

Page generated in 0.0778 seconds