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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.
331

Energikartläggning enligt ISO 50001 : En kartläggning av en industrianläggning för betong

Nilsson, Anneli, Hedberg, Fanny January 2014 (has links)
Den här rapporten har skrivits som en del av ett examensarbete på energiingenjörsprogrammet på Högskolan i Halmstad under våren 2014. Examensarbetet har genomförts i samarbete med AB Färdig Betong samt ÅF Infrastructure AB i Göteborg. Syftet med projektet är att undersöka energibesparingspotentialen hos AB Färdig Betongs produktionsanläggning på Ringön i Göteborg. Projektet har inneburit en energikartläggning av en industriell produktionsanläggning för lösbetong. Utgångspunkt för energikartläggningen har varit energiledningssystemet ISO 50001, med målsättningen att ta fram en teknisk energikartläggningsrapport i enlighet med standarden. Anläggningen har analyserats ur ett energibesparingsperspektiv. Data- och informationsinsamling samt mätningar har genomförts för att ta fram indata som beräkningsunderlag. Genom beräkningar har sedan möjliga energibesparingspotentialer och åtgärdsförslag tagits fram. Den totala energibesparingspotentialen för anläggningen innebär en besparing på 223 MWh av anläggningens totala energianvändning på 857 MWh år 2013, vilket motsvarar en minskning med omkring 26 %. Allmänna slutsatser är bland annat att all produktionsutrustning bör placeras inom klimatskalet, att all uppvärmning bör vara temperaturreglerad samt att ett mer långsiktigt energiperspektiv behövs i anläggningen. Energibesparingsmöjligheterna för anläggningen är mycket goda och investeringskostnaderna är i allmänhet låga. / This report has been written as part of a degree project at the Bachelor’s programme in energy engineering at Halmstad University in the spring of 2014. The project was made in collaboration with AB Färdig Betong and ÅF Infrastructure AB in Gothenburg. The project aims to investigate the potential energy savings of AB Färdig Betong’s production plant at Ringön in Gothenburg. The project was to make an energy audit of an industrial production plant for concrete. The starting point for the energy audit has been the ISO 50001 energy management system with the aim to develop a technical energy audit report in accordance with the standard. The plant has been analyzed from an energy perspective. Measurements, collection of data and information has been carried out to develop the input data basis. Through calculations, potential energy savings and proposals for actions were developed. Among the four largest energy saving potentials, there are two that have no investment cost at all. The total of all potentials represent a saving of 26 % of the total plant energy consumption of 857 MWh in 2013. General conclusions include that all production should be located within the building, that all heating should be temperature regulated and that a long term perspective on energy use is needed.
332

Research on reducing costs of underground ventilation networks in South African mines / Warren Christopher Kukard

Kukard, Warren Christopher January 2006 (has links)
South Africa is currently facing a major electricity crisis due to the continuous growth in electricity demand. Eskom, the largest electricity supplier in South Africa, have enabled numerous methods to support energy reduction in both the residential and industrial sectors. Programs developed by Eskom to help the different major electricity consuming industries with the development of energy efficient and load shift strategies, have already been put into practice. These programs solely focus on the potential savings in megawatts each production sector might consist of. The key features of the Eskom electricity reduction initiative are driven by the energy efficiency concept and the peak demand load shift capability. Both the load shift and energy efficient initiatives are mostly active in the mining industry, because of the high electricity consumption levels of a standard mining operation. One of the most inefficient systems currently active within a mining operation is the ventilation control system. This dissertation describes the energy efficient and load shift research on the current underground ventilation system by means of certain design methodologies that might improve the inefficient operational features on both the standard underground auxiliary fans and the main surface fans. The operational features of a standard 2-pole 45 kW issued auxiliary fan were tested, by using a fan-testing column to compare the performance criteria to that of an improved auxiliary fan design. An energy saving potential on a single 45 kW unit of 11 kW was evident during the testing analysis. This amounted to an estimated annual energy saving potential of R 370,000.00 with a total saving of 561 kW on all the installed 45 kW units at Kopanang goldmine, by means of an investment in the replacement of the current installed units with that of the improved units. A secondary study was to gather information on the main surface fan operational features at Kopanang and Mponeng goldmines. The gathered information showed an estimated possibility for load shift and efficiency initiatives, which will result in fan operating life expansion and electricity savings capabilities. Annual electricity savings of up to R I ,500,000.00 were calculated on efficiency and load shift strategies and gave an indication on how costly inefficient operations are. The calculated I 0% increase in main fan efficiency resulted in an annual saving of nearly R 1,100,000.00 with a reduction of 1,05 MW at Mponeng goldmine and an annual saving of nearly R 721,000.00 with a reduction of 675 kW at Kopanang goldmine. The load shift potential at Mponeng and Kopanang goldmines were nearly 3,5 MW and 2,25 MW respectively. Capital investments from either Eskom or alternative investors will definitely play a crucial part in the realization of energy efficiency and load shift measures. It may include, improved fan installations, variable speed drives for the main fans and real time management systems. If the mine should decide to invest in these efficient strategies, the proposed Eskom DSM program might result in a net energy savings potential for any mining operation. / Thesis (M.Ing. (Electrical Engineering))--North-West University, Potchefstroom Campus, 2007.
333

Research on reducing costs of underground ventilation networks in South African mines / Warren Christopher Kukard

Kukard, Warren Christopher January 2006 (has links)
South Africa is currently facing a major electricity crisis due to the continuous growth in electricity demand. Eskom, the largest electricity supplier in South Africa, have enabled numerous methods to support energy reduction in both the residential and industrial sectors. Programs developed by Eskom to help the different major electricity consuming industries with the development of energy efficient and load shift strategies, have already been put into practice. These programs solely focus on the potential savings in megawatts each production sector might consist of. The key features of the Eskom electricity reduction initiative are driven by the energy efficiency concept and the peak demand load shift capability. Both the load shift and energy efficient initiatives are mostly active in the mining industry, because of the high electricity consumption levels of a standard mining operation. One of the most inefficient systems currently active within a mining operation is the ventilation control system. This dissertation describes the energy efficient and load shift research on the current underground ventilation system by means of certain design methodologies that might improve the inefficient operational features on both the standard underground auxiliary fans and the main surface fans. The operational features of a standard 2-pole 45 kW issued auxiliary fan were tested, by using a fan-testing column to compare the performance criteria to that of an improved auxiliary fan design. An energy saving potential on a single 45 kW unit of 11 kW was evident during the testing analysis. This amounted to an estimated annual energy saving potential of R 370,000.00 with a total saving of 561 kW on all the installed 45 kW units at Kopanang goldmine, by means of an investment in the replacement of the current installed units with that of the improved units. A secondary study was to gather information on the main surface fan operational features at Kopanang and Mponeng goldmines. The gathered information showed an estimated possibility for load shift and efficiency initiatives, which will result in fan operating life expansion and electricity savings capabilities. Annual electricity savings of up to R I ,500,000.00 were calculated on efficiency and load shift strategies and gave an indication on how costly inefficient operations are. The calculated I 0% increase in main fan efficiency resulted in an annual saving of nearly R 1,100,000.00 with a reduction of 1,05 MW at Mponeng goldmine and an annual saving of nearly R 721,000.00 with a reduction of 675 kW at Kopanang goldmine. The load shift potential at Mponeng and Kopanang goldmines were nearly 3,5 MW and 2,25 MW respectively. Capital investments from either Eskom or alternative investors will definitely play a crucial part in the realization of energy efficiency and load shift measures. It may include, improved fan installations, variable speed drives for the main fans and real time management systems. If the mine should decide to invest in these efficient strategies, the proposed Eskom DSM program might result in a net energy savings potential for any mining operation. / Thesis (M.Ing. (Electrical Engineering))--North-West University, Potchefstroom Campus, 2007.
334

Pensionssparande : Vilka faktorer påverkar sparandet? / Retirement Savings : Which factors affect savings?

Mistander, Cecilia, Saundersson, Filip January 2014 (has links)
Syfte: Denna studie syftar till att undersöka vilka variabler som påverkar olika frågor gällande pension. De frågorna angående pensionen som undersöks är:Vilka människor… … har tänk på sin pension? … har ett privat pensionssparande? … tänker jobba och ta ut pension samtidigt? … planerar att gå i pension tidigt respektive sent? Metod: Undersökningen utförs med en kvantitativ metod. Enkätundersökningen som analyseras kommer från en tidigare undersökning gjord av Finseraas och Jakobsson (2013). Uppsatsen följer en induktiv metod. Slutsats: Studien visar att variablerna som ingick i grundmodellen, vilka är kön, ålder, utbildningsnivå, civilstånd och inkomst, alla var signifikanta i en eller fler av frågorna som undersöks. Men även en del andra variabler visade sig vara av betydelse. / Objective: This study aims to examine which variables have an effect on questions regarding retirement. The questions are as follows: Which individuals… …have thought about their retirement? …are saving privately for their retirement? …plan to work at the same time as they receive pension? …are planning for early or late retirement? Methodology: The study is conducted using a quantitative method. The data analyzed comes from an earlier survey conducted by Finseraas and Jakobsson (2013). The essay follows an inductive method. Conclusion: The study shows that the variables included in the basic model, which are gender, age, education, marital status and income, all were significant in one or more of the questions under investigation. Some other variables were found to be of significance.
335

On Physical Relations in Driving: Judgements, Cognition and Perception

Eriksson, Gabriella January 2014 (has links)
Drivers need to make judgements of physical relationships related to driving speed, such as mean speed, risks, travel time and fuel consumption, in order to make optimal choices of vehicle speed. This is also the case for the general public, politicians and other stakeholders who are engaged in traffic issues. This thesis investigates how drivers’ judgements of travel time (Study I and II), fuel consumption (Study III) and mean speed (Study IV) relate to actual physical measures. A cognitive time-saving bias has been found in judgements of travel time. The time saving bias implies that people overestimate the time saved when increasing speed from a high speed and underestimate the time saved when increasing speed from a low speed. Previous studies have mainly investigated the bias from a cognitive perspective in questionnaires. In Study I the bias was shown to be present when participants were engaged in a driving simulator task where participants primarily rely on perceptual cues. Study II showed that intuitive time saving judgements can be debiased by presenting drivers with an alternative speedometer that indicate the inverted speed in minutes per kilometre. In Study III, judgements of fuel consumption at increasing and decreasing speeds were examined, and the results showed systematic deviations from correct measures. In particular, professional truck drivers underestimated the fuel saving effect of a decrease in speed. Study IV showed that subjective mean speed judgements differed from objective mean speeds and could predict route choice better than objective mean speeds. The results indicate that biases in these judgements are robust and that they predict behaviour. The thesis concludes that judgements of mean speeds, time savings and fuel consumption systematically deviate from physical measures. The results have implications for predicting travel behaviour and the design of driver feedback systems. / Förare bör göra bedömningar som relaterar till hastighet, såsom bedömningar av medelhastighet, risk, restid och bränsleåtgång. Dessa bedömningar är nödvändiga för att föraren ska kunna välja en optimal hastighet, men också för att allmänheten, politiker och andra intressenter som är involverade i trafikfrågor ska kunna fatta välgrundade beslut. Denna avhandling består av fyra delstudier där förares bedömningar av restid (Studie I och II), bränsleåtgång (Studie III) och medelhastighet (Studie IV) studeras i relation till faktiska fysikaliska mått. Tidigare enkätstudier har påvisat ett kognitivt bias i tidsvinstbedömningar vid höga och låga hastigheter som påverkar mänskligt beteende. Studie I visade att detta bias också förekommer i en primärt perceptuell motorisk uppgift där förarna i studien kör i en körsimulator. Studie II visade att dessa intuitiva tidsbedömningar kan förbättras genom att köra med en alternativ hastighetsmätare i bilen som indikerar den inverterade hastigheten i minuter per kilometer istället för hastigheten i kilometer per timme. I Studie III undersöktes bedömningar av bränsleåtgång vid hastighetsökningar och hastighetssänkningar, och resultaten visar att bedömningarna systematiskt avviker från faktisk bränsleåtgång. Ett intressant resultat var att lastbilsförare i allmänhet underskattade bränslebesparingen som kan göras till följd av en hastighetssänkning. Studie IV visade att subjektiva bedömningar av medelhastighet som avviker från objektiva medelhastigheter kan predicera vägval, vilket tyder på att systematiska fel i dessa bedömningar är robusta och kan predicera vägval. Sammanfattningsvis visar avhandlingen hur bedömningar av medelhastighet, tidsvinst och bränsleåtgång systematiskt avviker från fysikaliska mått. Resultaten har betydelse för modellering av resebeteende och design av förarstödssystem. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 3: Submitted.</p>
336

Design and Development of an Intelligent Energy Controller for Home Energy Saving in Heating/Cooling System

Abaalkhail, Rana 18 January 2012 (has links)
Energy is consumed every day at home as we perform simple tasks, such as watching television, washing dishes and heating/cooling home spaces during season of extreme weather conditions, using appliances, or turning on lights. Most often, the energy resources used in residential systems are obtained from natural gas, coal and oil. Moreover, climate change has increased awareness of a need for expendable, energy resources. As a result, carbon dioxide emissions are increasing and creating a negative effect on our environment and on our health. In fact, growing energy demands and limited natural resource might have negative impacts on our future. Therefore, saving energy is becoming an important issue in our society and it is receiving more attention from the research community. This thesis introduces a intelligent energy controller algorithm based on software agent approach that reduce the energy consumption at home for both heating and cooling spaces by considering the user’s occupancy, outdoor temperature and user’s preferences as input to the system. Thus the proposed approach takes into consideration the occupant’s preferred temperature, the occupied and unoccupied spaces, as well as the time spent in each area of the home. A Java based simulator has been implemented to simulate the algorithm for saving energy in heating and cooling systems. The results from the simulator are compared to the results of using HOT2000, which is Canada’s leading residential energy analysis and rating software developed by CanmetENERGY’s Housing, Buildings, Communities and Simulation (HBCS) group. We have calculated how much energy a home modelled will use under emulated conditions. The results showed that the implementation of the proposed energy controller algorithm can save up to 50% in energy consumption in homes dedicated to heating and cooling systems compared to the results obtained by using HOT2000.
337

Assessing Thermal Performance Of Office Building Envelopes / A Case Study On Energy Efficiency

Surmeli, Ayse Nesen 01 June 2004 (has links) (PDF)
In this study, the energy conservation potential of selected retrofitting interventions on an office building were investigated, on the basis of which some rational strategies for the improvement of building envelopes in terms of energy, environment and comfort design were proposed. Examined were various measures on envelope constructions that can be retrofitted to existing buildings. By using simulation techniques, the effectiveness of such measures in reducing energy consumption and environmental threat were also assessed. Effects of glazing types, effect of insulation and thermal mass were analyzed as energy efficient retrofit measures to the Engineering Building (MM building) situated on Middle East Technical University Campus, Ankara. The Energy-10 computer program was used for the modeling and simulation of the energy flows through the envelope to examine measures for reducing thermal load. Within this framework, the energy conservation potential of single and combined retrofitting actions was investigated. Based on results from the evaluation model, it was found that a saving of 161.20 MWh in the annual heating load could result, depending on the glazing type. The evaluation showed that thermal insulation is the most effective factor in thermal performance when placed as an exterior layer on walls. The study showed thermal mass has significant impact on increasing the duration, where highest temperatures were achieved, under passive mode. The study also revealed that applying a combination of retrofitting measures which responded to the challenges and opportunities presented by different fa&ccedil / ade orientations, a saving of 52.41% can be achieved in annual heating energy use in case study building.
338

Determinants Of Current Account Deficits In Industrialized And Developing Coiuntries: An Empirical Investigation

Kaya Bahce, Secil Aysed 01 August 2005 (has links) (PDF)
This study aims to analyze the determinants of the current account deficits for a broad samples of industrial and developing countries for the period 1984-2001. Using a dynamic panel data estimation procedure, we try to unfold the impact of several macro economic and institutional variables on current account deficits. In this context, we also examine the validity of Feldstein Horioka puzzle and its relevance to the current account imbalances. Results show that better governance, a more sophisticated financial system, relatively larger country size and deterioration in the terms of trade are associated with higher current account deficits. On the other hand, exchange rate regime flexibility, openness to foreign trade and depreciation of the real exchange rate lead to smaller current account deficits. We also find that the saving investment relationship is still considerably high both in the short run and in the long run.
339

児童期における経済学的理解の発達 - 貯蓄・購買行動と経済学的事象に関する推理 -

藤村, 宣之, FUJIMURA, Nobuyuki, 子安, 増生, KOYASU, Masuo 27 December 2005 (has links)
国立情報学研究所で電子化したコンテンツを使用している。
340

A macroeconomic model of differential growth effects of national sectoral saving and foreign borrowing : an application to Thai data

Kanjanee Kangwanpornsiri January 1985 (has links)
Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1985. / Bibliography: leaves [125]-129. / Photocopy. / x, 129 leaves, bound ill. 29 cm

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