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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.
1

Cost-Benefit Assessments of Distributed Power Generation

Yu, Sen-Yen 10 July 2003 (has links)
Abstract The most common application of Distributed Generation (DG) is for reliability reasons. After experiencing an interruption, backup generators can be started to supply electricity to critical loads. The next most common application for DG is peak load shaving. During time periods of high energy demand or high energy prices, on-site generators are started up and used to serve part of the on-site loads. So DG can increase reliability of power supply, reduce loss of interruption and solve the problem of peak loads. Due to the high costs, only a few were installed. In order to investigate their economic values, in this thesis, several economic assessment methods are used to evaluate the cost-benefit of DG. Test results have revealed that, unless it is for environment protection reasons, the investment of DG is of little value if the fuel cost is high, and the electricity and the customer interruption costs are low. Keyword : Distributed Generation¡Mpeak load shaving.
2

Leather Shaving – A New Approach for Understanding the Shaving Process

Witt, Tilman, Klüver, Enno, Nikowski, A., Meyer, M. 05 July 2019 (has links)
Content: The shaving process is one of the most important steps in leather production. However, the underlying principles and mechanisms are not yet fully understood. Generally, the successful performance of the shaving process is based on long-time experience, and the tanneries rather optimize the preceding process steps than change the shaving parameters. In a current research project the research partners (Heusch GmbH, TU Dresden and FILK gGmbH) have united their expertise in order to understand the interaction between the shaving blade and the semi-finished leather (wet-blue or wet-white). The objective of the project is to gain more insight into the physics of shaving and to create a background of knowledge, which will be the technical base for developing novel and more effective shaving blades. Heusch presents the advantages of a novel serrated shaving blade. In comparison with the standard design an serrated blade yields higher shaving accuracy and uniform thickness of the hides. Stretching forces along the dorsal line of the hides are reduced, which avoids structural damage. Marginal hide regions are less frayed, thus increasing the usable surface area. The small size and compact form of the shavings are advantageous for recycling and disposal. Exploiting these advantages combined with an optimized grinding process, the user can increase the lifetime of the serrated blades. Based on these experiences there is an urgent need to thoroughly understand the physical cutting processes which take place during the shaving step. In the current research project an experimental test station is designed which is intended to simulate the shaving process in a simplified setting as a cutting procedure of a blade into a leather surface. This test station will enable the variation of material, geometry and configuration of the blade as well as the measurement of forces emerging during cutting at the blade and the leather surface, which emerge during cutting. The registered data shall provide information on the question, how the cutting forces depend on technological parameters, like blade material, geometry, configuration, cutting speed, leather moisture or tanning method. Based on the knowledge of these relationships novel, even more effective shaving blades can be developed. In a second approach the cutting process of a single leather fibre will be simulated virtually on a microscale level. The goal is the understanding of the interaction of a moving metal blade with a flexible, unilaterally fixed leather fibre. The simulation is supposed to yield data on cutting speed and fibre behaviour under conditions which are experimentally difficult to access. Take-Away: The physical basics of the shaving process are not yet fully understood. The presented research project aims at the understanding of the interaction between shaving blade and leather fibres during the shaving process. The approach in the project is to model the cutting procedure in a simplified experimental test station and in a computational simulation model.
3

Analysis of Distributed Resources Potential Impacts on Electric System Efficacy

Robinson, Paul E 17 December 2009 (has links)
"The intent of this Thesis is to study the potential of distributed resources to increase the efficacy of the electric system without decreasing the efficiency of the system. Distributed resources (DR) are technologies that provide an increase in power or a decrease in load on the distribution system. An example of DR is a storage device that uses electricity during low use periods to store energy and then converts the stored energy to power during high use periods. The energy storage being studied is for the purpose of peak shaving or the ability to shift small amounts of load to a more optimum time. In particular the concept of load curve leveling is explored. DR options are studied to determine how size, location, and storage losses impact the overall system efficacy and efficiency. This includes impacts on system losses, capacity utilization, and energy costs."
4

Residential Battery Energy Storage Systems for Renewable Energy Integration and Peak Shaving

Leadbetter, Jason 14 August 2012 (has links)
Renewable energy integration will become a significant issue as renewable penetration levels increase, and will require new generation support infrastructure; Energy storage provides one solution to this issue. Specifically, battery technologies offer a wide range of energy and power output abilities, making them ideal for a variety of integration applications. Distributed energy storage on distribution grids may be required in many areas of Canada where renewables will be installed. Peak shaving using distributed small (residential) energy storage can provide a reduction in peak loads and help renewable energy integration. To this end, a peak shaving model was developed for typical houses in several regions in Canada which provided sizing and performance results. An experimental battery bank and cycling apparatus was designed and constructed using these sizing results. This battery bank and cycling apparatus was then used to calibrate and validate a lithium iron phosphate battery energy storage system model.
5

Undersökning av kombinerade lönsamhetsstrategier för ett batterilager / Analysis of combining profitability strategies to increase profitability of a battery storage

Bouveng Sellin, Alexander January 2022 (has links)
The increasing electricity production from intermittent energy sources creates both challenges and possibilities in the future energy system. When the controllability in the production of electricity deteriorates, the flexibility of the electricity consumption must increase for the energy system to work. The study examines the possibilities for the profitability strategies load smoothing, peak shaving, participation on the flexibility market and its combinations to reduce the electricity bill for Vasakronan’s office building at Sperlingens Backe 47 in Stockholm using a nickel-metal hydride (NiMH) battery storage. The results indicated participation on the flexibilitymarket to be the most profitable strategy although none of the strategies nor their combinations managed to reduce the electricity bill of the office building. For an installation of a NiMH battery in the office building to become profitable, the price of NiMH batteries must decrease by approximately 80 %.
6

Implementering av V2G i mobilitetshuset Dansmästaren : En modelleringsstudie

Nabiallahi, Edwin, Alabassi, Mahmoud, Ali, Roni, Lundström, Marcus, Jonsson, Oscar, Sjögren, Johan, Nordén, Kajsa January 2021 (has links)
Uppsala’s population and infrastructure is expanding at a fast rate. This results in problems with supplying sufficient electrical power during peak hours such as early mornings and late evenings. One of the many ways to solve this issue is through peak shaving by using parked electrical vehicles as batteries to discharge into the power grid (vehicle-to-grid). In this report, the possibilies for peak shaving during peak hours in a mobility house called Dansmästaren are presented, as well as the possibilities for the vehicle-to-grid technology in the future. Dansmästaren has 60 available parking slots for electric vehicles, and a large central battery available.Through simulations using MATLAB, the results show that it’s possible to achieve a considarable degree of peak shaving, while battery degradation is kept reasonably low. Conclusions regarding vehicle-to-grid in the future are that there is a large potential for Vehicle-to-grid to become an important part of tomorrow’s energy system. However, continued research and development is necessary, as well as bigger focus on the social and economic aspects of this technology. A succesful implementation will require cooperation between the grid owners, the industry and the customers.
7

Let Her Be Shorn: 1 Corinthians 11 and Female Head Shaving in Antiquity

Montier, Curtis E. 12 1900 (has links)
In 1 Corinthians 11:3-15, Paul writes that if a woman is to be so immodest as to wear her hair uncovered while praying or prophesying in a Christian assembly she might as well shave her head. Paul instructs the Corinthians that it is “one and the same” for a woman to have her head shaved and for her to unveil her hair. There is a large body of works cataloging the modesty standards in Hellenistic Greece but Paul’s reference to head-shaving remains obscure. This thesis looks to find the best explanation of Paul’s instructions. Research in this topic began as an investigation of a popular modern view. It can be found in conversation or a simple Google search, that women in Ancient Greece with their head shaved were prostitutes. Beyond being prostitutes, they were probably temple prostitutes. The evidence does not bear this out as there is no artwork depicting prostitutes, or indeed any women, with their heads shaved. Instead prostitutes are shown in Greek erotic art with both long and short hair, some with and some without head coverings. Literary sources do offer several different examples of women who had their hair cut off. There are examples of women shaving their hair off in Lucian’s The Syrian Goddess, Tacitus’ Germania, Plutarch’s Lycurgus and Roman Questions, several Talmudic sources, and On Fortune II, formerly attributed to Dio Chrysostom. By examining these sources in tandem with 1 Corinthians 11, the most probable impetus behind Paul’s writing relates to punishments for adultery.
8

Identificação de proteínas de superfície de Staphylococcus saprophyticus e análise de fatores de virulência / Identification of surface proteins of Staphylococcus saprophyticus and analysis of virulence factors

Carvalho, Alex Jesus de 09 June 2014 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2016-04-20T12:49:28Z No. of bitstreams: 2 Dissertação - Alex Jesus de Carvalho - 2014.pdf: 1685689 bytes, checksum: 5b4f38809e4a3fe6252bba20b25d949b (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-04-20T12:58:32Z (GMT) No. of bitstreams: 2 Dissertação - Alex Jesus de Carvalho - 2014.pdf: 1685689 bytes, checksum: 5b4f38809e4a3fe6252bba20b25d949b (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-04-20T12:58:33Z (GMT). No. of bitstreams: 2 Dissertação - Alex Jesus de Carvalho - 2014.pdf: 1685689 bytes, checksum: 5b4f38809e4a3fe6252bba20b25d949b (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-06-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The Gram-positive bacterium Staphylococcus saprophyticus, one of the coagulasenegative staphylococci, is the second most common causative agent of urinary tract infection, affecting mainly sexually active women. Staphylococcus saprophyticus can cause acute diseases as pyelonephritis, sepsis, nephrolithiasis, endocarditis, urethritis, epididymitis and prostatitis. This work aims to identify Staphylococcus saprophyticus surface proteins by using a proteolytic shaving approach, a methodology that was established to identify surface-exposed protein domains by tripsinization of intact cells. The peptides obtained were treated by trypsin, reduced, alkylated and identified by nano-chromatography using a nanoACQUITY UPLCTM system (Waters) coupled to a SYNAPT Q-TOF mass spectrometer (Waters). The homology analysis was performed using the software ProteinLynx 2.3 (Waters). Through the shaving, it was possible to identify 219 proteins, many of them, described as virulence factors. Of total, 01 is cell wall protein, 09 are extracelular proteins, 19 are membrane proteins and 190 are citoplasmatic proteins. Besides of the lysis process, the presence of cytoplasmic proteins on cell surface can be due to the activity of export pathways not yet identified and many of these proteins can be proteins with moonlighting function, in other words, proteins that plays more of one function, it can, in this case, plays functions on S. saprophyticus cell surface related to bacterial virulence. The main proteins with moonlighting function include metabolic enzymes of the glycolytic pathway; enzymes of other metabolic pathways, such as, glyoxalate cycle; chaperones and proteins related with the proteic folding. The prediction of cellular localization was performed through LocateP database. The results of this research help to elucidate the strategies and machineries used by proteins during the adhesion, infection and proliferation, leading us to understand the interaction between the pathogenic bacteria S. saprophyticus and the human host. The knowledge about the proteins present on the cell surface is of extreme importance, because many of these proteins represent targets to new drugs, therapeutic antibodies or vaccines, since the pathogen cell surface is the first to contact with the host cells during the infection process. / A bactéria Gram-positiva Staphylococcus saprophyticus, uma das bactérias estafilococos coagulase negativa, é o segundo agente mais comum causador de infecções do trato urinário, afetando principalmente mulheres sexualmente ativas. S. saprophyticus pode causar doenças agudas como pielonefrite, sepse, nefrolitíase, endocardite, uretrite, epididimite e prostatite. Este trabalho teve como objetivo identificar proteínas de superfície de S. saprophyticus pela abordagem de shaving proteolítico, uma metodologia que foi estabelecida para identificar proteínas que possuem domínios proteicos na superfície celular utilizando a tripsinização de células intactas. Posteriormente, os peptídeos obtidos foram tripsinizados, reduzidos, alquilados e identificados através de nano-cromatografia utilizando um sistema nanoACQUITY UPLCTM (Waters) acoplado a um espectrômetro de massas SYNAPT Q-TOF (Waters). Com isso foi possível identificar 219 proteínas, muitas delas descritas como fatores de virulência. Do total, 01 proteína é de parede celular, 09 extracelulares, 19 de membrana e 190 citoplasmáticas. Além do processo de lise, a presença de proteínas citoplasmáticas na superfície celular pode ser devida à atividade de vias de exportação ainda não identificadas e muitas dessas proteínas podem ser proteínas com função moonlighting, ou seja, proteínas que desempenham mais de uma função, podendo, neste caso, desempenhar funções na superfície de S. saprophyticus relacionadas à virulência bacteriana. As principais proteínas com função moonlighting incluem enzimas metabólicas da via glicolítica; enzimas de outras vias metabólicas, tais como, ciclo do glioxalato; chaperonas e proteínas relacionadas com o dobramento proteico. A predição de localização celular foi realizada com o banco de dados LocateP. Os resultados desta pesquisa contribuíram na elucidação das estratégias e maquinarias utilizadas pelas proteínas durante a adesão, infecção e proliferação, levando-nos a compreender a interação entre a bactéria patogênica S. saprophyticus e o hospedeiro humano. O conhecimento acerca das proteínas presentes na superfície celular é de extrema importância, visto que muitas dessas proteínas representam alvos para novas drogas, anticorpos terapêuticos ou vacinas, uma vez que a superfície celular do patógeno é a primeira a entrar em contato com as células do hospedeiro durante o processo de infecção.
9

Ett batterihybridfartygs driftsmöjligheter : Hur Coey Viking bör operera / The operational conditions of a battery-hybrid-vessel : How Coey Viking should operate

Olausson, Axel, Prahl, Niclas January 2021 (has links)
Syftet med arbetet var att undersöka hur ett nyproducerat batterihybridfartyg av PSV-typ (plattform supply vessel) bör operera för att uppnå en så energieffektiv drift som möjligt utan att äventyra säkerhet eller redundanskrav. Att framföra ett fartyg så energieffektivt som möjligt är något som är av hög prioritet till sjöss, dels ur ett ekonomiskt perspektiv men även ur miljösynpunkt, då sjöfartsbranschen ständigt arbetar för en minskad miljöpåverkan. Även nyproducerade fartyg, byggda med modern teknik som ger goda förutsättningar för en energieffektiv drift ställer stora krav på att det tydligt framgår hur fartyget ska framföras för att nyttja fartygets fulla potential och uppnå optimal drift. För att ta fram procedurer över hur fartygen bör operera har loggade och teoretiska data från fartyget Coey Viking sammanställts, och presenteras i samråd med Viking Supply Ships. Resultatet innefattar generatorkombinationers specifika bränsleförbrukning, lågtrycks-dual-fuel-motorers generella miljöpåverkan med avseende på metanslip och fartygets loggade effektförbrukning till kaj. Resultatet visade att hög generatorlast resulterade i optimal specifik bränsleförbrukningen, att låga generatorlaster genererade stort metanslip samt att en förändrad elkraftstyrning tillsammans med fartygets energilagring möjliggör en förbättrad drift till kaj med en minskad miljöpåverkan. Arbetet öppnar upp för vidare forskning inom optimal peak-shaving-effekt, hur energilagringens storlek påverkar driftsmöjligheter och hur peak-shaving till kaj på ett stabilt sätt reglertekniskt bör styras. / The purpose of this undertaking was to investigate a new built battery-hybrid-vessel of PSV-type (platform supply vessel) and its operational ability to achieve the most energy efficient operation without jeopardizing safety or redundancy. The energy efficient operation of a vessel is of great priority in the maritime industry, not only because of economical profit but also based on environmental perspective, since the maritime industry is constantly aiming towards a decreased environmental impact. Newly built vessels containing modern technology opens up great opportunity in achieving energy efficient operation, though it sets high standard regarding correct operation of the vessel to use its full potential and achieve optimal running. To be able to present procedures regarding the vessel’s operation, logged and theoretical data from the vessel Coey Viking has been compiled and is presented in consultation with Viking Supply Ships. The results refered to different generator combination’s specific fuel consumption, the general environmental impact of low pressure dual fuel engines with respect to methane slip and the vessel’s logged power consumption in port.  The result indicated that a high generator load resulted in optimal specific fuel consumption, while low generator loads resulted in poor specific fuel consumption together with an increase in methane slip. The result also showed that the vessel’s energy storage together with a change in the PMS-system (Power Management System) would enable an improved power supply in port with shore connection. The paper raises questions to be answered in further research regarding optimal peak-shaving effect, what impact the size of the energy storage would have on operational capability and how peak shaving in port with shore connection appropriately should be regulated.
10

Rozšířené využití bateriových systémů v průmyslových objektech / Advanced Use of Battery Storage System in Industry

Pinkoš, Patrik January 2018 (has links)
The Diploma thesis in theoretical part deals with description of possibilities of accumulations of electricity energy focusing on electrochemical accumulators. Next chapter of theory also describes possible applications of battery storages focusing on costumer. In practical part diploma thesis deals with suggestion of simulation model for battery application peak-shaving. Output of the suggestion represents two case studies based on real data of commercial building consumption. Furthermore, practical part also deals with suggestion of control logic for application peak-shaving which was used for verification of simulation model.

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