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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.
51

Optimering och effektivisering av biogasprocessen vid biogasanläggningen Kungsängens gård / Optimization and potentiation of the biogasprocess at the biogas plant Kungsängens gård

Frid, Sara January 2012 (has links)
Under år 2008 användes globalt en energimängd motsvarande nästan 144 000 TWh ochav dessa stod fossila bränslen för 81 %. I Sverige uppgick energitillförseln under år2010 till totalt 616 TWh och av detta stod råolja/oljeprodukter för 30,4 %. Vidförbränning av fossila bränslen frigörs koldioxid, en gas som bidrar till att förstärkaväxthuseffekten. År 2000 uppmättes halten av koldioxid i atmosfären till 370 ppmv ochför att den globala temperaturen inte ska öka med mer än 2°C bör halten stanna på 450ppmv innan år 2100. Ett sätt att minska andelen av fossila bränslen är att öka andelen avförnybara energikällor, som t.ex. biogas, som i Sverige uppskattas kunna ge enenergimängd motsvarande 10-15 TWh/år i framtiden.Vid biogasanläggningen Kungsängens gård, Uppsala, samrötas slakteriavfall samtorganiskt avfall från hushåll och livsmedelsindustri i en termofil rötningsprocess. Underår 2011 producerades ca 3 400 000 Nm3 biogas och den största andelen uppgraderadestill fordonsgas. Behovet fordonsgas i Uppsala ökar och i detta examensarbete utreddestvå sätt att effektivisera processen och öka gasproduktionen. Dels undersöktes om enökad belastning skulle ge en ökad biogasproduktion utan att riskera processensstabilitet. Detta gjordes i två labskalereaktorer där belastningen ökades gradvis i denena. Dels studerades möjligheten att minska energiförbrukningen på anläggningengenom att byta hygieniseringsmetod. Innan substratet matas in i rötkamrarna måste dethygieniseras, vilket i dagsläget görs genom pastörisering (upphettning till 70oC under entimme). Då detta är väldigt energikrävande finns det planer på att byta metod ochistället låta substratet hygieniseras i rötkamrarna (52°C) i minst 10 timmar. Det är dockviktigt att beakta huruvida metanpotentialen för pastöriserat och opastöriserat materialskiljer sig åt, varför detta utreddes i sk satsvisa utrötningsförsök.Genom hela belastningsökningen (från 3 till 6 kg VS/m3,d) ökade biogasproduktionenoch vid den högsta belastningen var ökningen 100 % jämfört med dagens nivå. Andraviktiga processparametrar, så som specifik gasproduktion, kvoten CO2/CH4, pH,halterna av fettsyror och utrötningsgraden, låg på en jämn nivå under försöket, vilkettyder på att processen var stabil trots den ökade belastningen. Utrötningsförsöket visadeatt pastöriseringen inte hade någon effekt på metanproduktionen, troligtvis eftersomsubstratet redan var lättnedbrytbart. Beräkningen av energiförbrukning visade attenergianvändningen skulle minska med ca 33 % vid byte av hygieniseringsmetod. / During 2008 an amount of energy equivalent to almost 144,000 TWh was used globally,of which fossil fuels accounted for 81 %. In Sweden, during 2010, an amount of energyequivalent to 616 TWh was used, of which crude oil/oil products accounted for 30.4 %.Carbon dioxide, a gas that contributes to the global warming, is produced during thecombustion of fossil fuels. In 2000 the levels of carbon dioxide in the atmosphere wasmeasured to be 370 ppmv and if the global temperature is not to increase with morethan 2°C, the levels should stay at 450 ppmv by 2100. One way of decreasing the use offossil fuels is to increase the use of renewable energy, such as biogas. In the futurebiogas can, approx., provide with energy equivalent to 10-15 TWh/year in Sweden.At the biogas plant Kungsängens gård, in Uppsala, slaughterhouse byproducts are codigestedwith source separated household waste and waste from the food processingindustry in a thermophilic process. During the year 2011 approximately 3,400,000 Nm3of biogas was produced at the plant, of which most was upgraded to vehicle fuel. Theconsumption of vehicle fuel is increasing in Uppsala and thus there is a need forincreased biogas production. The aim of this master thesis was to investigate two waysto increase the efficiency and consequently the gas production at the biogas plant atKungsängens gård. Firstly, it was studied if an increased organic loading rate (OLR)would give an increased biogas production, without disturbing the process. This wasdone in two lab scale reactors, where the load was increased gradually in one. Secondly,the possibility to decrease the energy consumption by means of a change of sanitizationmethod was studied. The substrate has to be sanitized before it is fed to the digesters,currently this is done by pasteurization. This process is, however, energy-demandingand there are plans to change the method of sanitization. It is, however, important toconsider whether the methane potential differs for the pasteurized and the nonpasteurizedsubstrate. This was studied in small scale biogas batch reactors.Through all stages of increased OLR (from 3 to 6 kg VS/m3, d) the biogas productionincreased, and at the largest load the increase was 100 % compared to the present level.Other important process parameters, such as specific methane production, CO2/CH4-ratio, pH, levels of fatty acids and degree of digestion, were at regular levels and thisindicates that the process was maintained stable in spite of the increased load. The testin the small scale biogas batch reactors showed that pasteurization of the substrate hadno effect on the methane potential, probably due to that the substrate already is readilybiodegradable. The estimation of the energy consumption showed that the use of energyshould decrease with approx. 33 % if the sanitization was replaced.
52

Sensorless Speed Control of Permanent Magnet-Assisted Synchronous Reluctance Motor (PMa-SynRM)

Chakali, Anil K. 2009 December 1900 (has links)
An interesting alternative for today's high efficiency variable speed drives is the Permanent Magnet-Assisted Synchronous Reluctance Motor drive, which belongs to the family of brushless synchronous AC motor drives. Generally, the reluctance torque of this motor is significant compared to the Permanent Magnet electrical torque. The advantage of increased reluctance torque is the decreased need of expensive permanent magnet (PM) material, which makes this solution thus cheaper than the respective permanent magnet motor. Also due to its synchronous operation, sensorless rotational control is possible along with higher power factor and better efficiency compared to the induction motor (IM). Therefore, this thesis first deals with the implementation of a vector control strategy for speed control of the PMa-synRM motor that can be applied to a washing machine application. The machine is supplied by a current controlled voltage source PWM inverter to control the instantaneous stator currents which are decided by the reference speed. Secondly, the thesis focuses on the sensorless speed operation of the PMa-SynRM to take advantage of the lower costs as well as increased system reliability which otherwise is not possible using the delicate speed or position sensors. The concept involves estimation of the rotor speed and/or position. There are several speed estimation techniques proposed by researchers and among them the observer based technique is proven and commonly used in the industry. The only requirements of the observer system are a very fast signal processor, specialized and optimized to perform complex mathematical calculations. The feasibility and effectiveness of the control techniques are verified using the experimental results, implemented using the Texas Instruments TMS320F2812 eZDSP controller board and the overall motor drive system in the laboratory.
53

Padidėjusio moterų kūno plaukuotumo sąsajų su biocheminiu hiperandrogenizmu įvertinimas / The assesment of relationship between increased body hair growth and biochemical hyperandrogenism in women

Kozlovienė, Dalia 25 January 2006 (has links)
Objective To determine the relationship between increased body hair growth in women and serum sex hormone level, body mass index, and clinical signs. Sample and methods The sample group consisted of 186 women, 18–35 year old residents of Lithuania who were referred to the Clinic of Endocrinology, Kaunas University of Medicine Hospital in 2002–2004 and complained for increased body hair growth. Exclusion criteria: 1) taking systemic medications within the period shorter than three months before the beginning of the study; 2) specific reasons of excessive body hair growth, such as androgen secreting adrenal or ovarian tumors, hyperprolactinemia, Cushing syndrome; 3) thyroid dysfunction. A total number of 37 women were excluded from further study. Statistical analysis was performed on 149 women. Increased body hair growth was assessed using Ferriman-Gallwey (F-G) method. Blood samples were drawn in the morning (08:00–10:00 h), in the early follicular phase, with an exclusion of 7 women with amenorrhea, while the blood sample of 12 women with oligomenorrhea was drawn following at least 2 months after the last menstruation. Serum hormones (total testosterone (T), sex hormone binding globulin (SHBG), free androgen index (FAI), dehydroepiandrosterone sulphate (DHEAS) level were measured using the commercial kits. FAI was calculated as follows: T (nmol/l) × 100/ SHBG (nmol/l). Results The significance of correlations between the F-G score and the tested variables decreased in the... [to full text]
54

Improved gold recovery by accelerated gravity separation / du Plessis J.A.

Du Plessis, Jan Antonie January 2011 (has links)
This project was specifically aimed at using increased acceleration separation, as a method to optimize the recovery of gold in an ore body mainly consisting of hematite. The specific gravity of gold is much higher in comparison to the carrying material, making it possible to separate gold from other materials such as silica, base metals and their oxides, usually associated with gravitation–gold–recovery processes. The ore body investigated in this project originated from a mined gold reef containing a large proportion of gold locked inside the gold pyrite complexes. In the mine's processing plant a gold pyrite concentrate was produced by means of a flotation process. The roasting process that followed, oxidized the pyrite to iron oxide (hematite) and sulphur dioxide. The gold particles which were locked up inside the pyrite gold complex were exposed or liberated, allowing the chemicals to penetrate the complex and dissolve the gold. After the cyanide gold extraction process, the material was pumped on to a mine reserve dump, referred to as tailings or tailings reserve dump. The tailings usually contain iron oxides, free gold, gold associated with iron oxides and gold associated with silica, and free silica, commonly referred to as calcine. The gold content on the calcine dump was significantly lower than the flotation concentrate before the extraction of the gold and it was no longer viable for the mine to process the tailings further. As the volume of the mine reserve dump increased over the years, it became viable to recover the gold in a high volume low grade plant. Several attempts were made to recover the gold in this dump, but due to the high cost of processing and milling the material, it was not done. The norm in the mining industry is that it is impossible to concentrate the gold by means of gravity separation techniques where the average particle sizes are smaller than 50 um in diameter and upgrading with inexpensive gravity separation techniques was ruled out by the mine, because the average particle sizes were too small. The dump investigated in this project differed from other reserve dumps in that the main phase of material in this dump was hematite and not silica. A suspension of this material would have different fall–out properties than other mine reserve dumps, because of the hematite's high specific gravity compared to silica. This property of the material birthed the idea that the material will respond positively to high acceleration separation, although the particle sizes were too small for effective upgrading according to the norm in the mining industry. Using acceleration concentration as a first stage in the gold recovery process the production cost per gram of gold produced could be reduced significantly. Firstly, the volume of concentrated material to be treated in the chemical extraction process was reduced ninety percent and secondly, the gold concentration was increased significantly. If the gold could be concentrated to more than twenty grams of gold per ton, it could be extracted economically with an aggressive chemical processes. This was not possible with low grade material contained in the dump. The theoretical principle, on which this project was based, was to make use of high acceleration separation to establish separation between the particles associated with the gold, and the particles not associated with gold. Applying a high gravitational force would have an influence on the velocity by which the particles would fall–out in a suspension. As the acceleration force increased the fall–out velocity would also be increased and the particles with higher specific gravity would be affected more. A factor that was equally important was the particle size and weight distribution. A large hematite particle would compete with a small gold particle due to the similarity in weight. This could cause loss in small gold particles or retention of hematite particles with no gold content. Very little scientific information was available on the material investigated and in order to assemble a concentration plant setup, the head grade and particle size distribution for both the dump and bulk sample were determined accurately. Thereafter, chemical analyses and mineralogical examination were done on a representative sample of the bulk sample, determining the chemical composition of the material. The results obtained thereof were evaluated and used to configure a pilot plant. A large bulk sample was processed in the pilot plant and from the analytical results the efficiency could be evaluated. The results at optimum acceleration forces applied, resulted in a recovery of 5% of the mass, with a gold concentrate of 90 g/t Au, which represented 58% recovery of the gold. The hematite with high specific gravity as main phase positively influenced the high acceleration separation process. It proved that if the specific gravity of particles in a suspension were increased, high acceleration separation could be applied effectively to separate much smaller particle sizes. / Thesis (M.Sc. Engineering Sciences (Chemical and Minerals Engineering))--North-West University, Potchefstroom Campus, 2012.
55

Improved gold recovery by accelerated gravity separation / du Plessis J.A.

Du Plessis, Jan Antonie January 2011 (has links)
This project was specifically aimed at using increased acceleration separation, as a method to optimize the recovery of gold in an ore body mainly consisting of hematite. The specific gravity of gold is much higher in comparison to the carrying material, making it possible to separate gold from other materials such as silica, base metals and their oxides, usually associated with gravitation–gold–recovery processes. The ore body investigated in this project originated from a mined gold reef containing a large proportion of gold locked inside the gold pyrite complexes. In the mine's processing plant a gold pyrite concentrate was produced by means of a flotation process. The roasting process that followed, oxidized the pyrite to iron oxide (hematite) and sulphur dioxide. The gold particles which were locked up inside the pyrite gold complex were exposed or liberated, allowing the chemicals to penetrate the complex and dissolve the gold. After the cyanide gold extraction process, the material was pumped on to a mine reserve dump, referred to as tailings or tailings reserve dump. The tailings usually contain iron oxides, free gold, gold associated with iron oxides and gold associated with silica, and free silica, commonly referred to as calcine. The gold content on the calcine dump was significantly lower than the flotation concentrate before the extraction of the gold and it was no longer viable for the mine to process the tailings further. As the volume of the mine reserve dump increased over the years, it became viable to recover the gold in a high volume low grade plant. Several attempts were made to recover the gold in this dump, but due to the high cost of processing and milling the material, it was not done. The norm in the mining industry is that it is impossible to concentrate the gold by means of gravity separation techniques where the average particle sizes are smaller than 50 um in diameter and upgrading with inexpensive gravity separation techniques was ruled out by the mine, because the average particle sizes were too small. The dump investigated in this project differed from other reserve dumps in that the main phase of material in this dump was hematite and not silica. A suspension of this material would have different fall–out properties than other mine reserve dumps, because of the hematite's high specific gravity compared to silica. This property of the material birthed the idea that the material will respond positively to high acceleration separation, although the particle sizes were too small for effective upgrading according to the norm in the mining industry. Using acceleration concentration as a first stage in the gold recovery process the production cost per gram of gold produced could be reduced significantly. Firstly, the volume of concentrated material to be treated in the chemical extraction process was reduced ninety percent and secondly, the gold concentration was increased significantly. If the gold could be concentrated to more than twenty grams of gold per ton, it could be extracted economically with an aggressive chemical processes. This was not possible with low grade material contained in the dump. The theoretical principle, on which this project was based, was to make use of high acceleration separation to establish separation between the particles associated with the gold, and the particles not associated with gold. Applying a high gravitational force would have an influence on the velocity by which the particles would fall–out in a suspension. As the acceleration force increased the fall–out velocity would also be increased and the particles with higher specific gravity would be affected more. A factor that was equally important was the particle size and weight distribution. A large hematite particle would compete with a small gold particle due to the similarity in weight. This could cause loss in small gold particles or retention of hematite particles with no gold content. Very little scientific information was available on the material investigated and in order to assemble a concentration plant setup, the head grade and particle size distribution for both the dump and bulk sample were determined accurately. Thereafter, chemical analyses and mineralogical examination were done on a representative sample of the bulk sample, determining the chemical composition of the material. The results obtained thereof were evaluated and used to configure a pilot plant. A large bulk sample was processed in the pilot plant and from the analytical results the efficiency could be evaluated. The results at optimum acceleration forces applied, resulted in a recovery of 5% of the mass, with a gold concentrate of 90 g/t Au, which represented 58% recovery of the gold. The hematite with high specific gravity as main phase positively influenced the high acceleration separation process. It proved that if the specific gravity of particles in a suspension were increased, high acceleration separation could be applied effectively to separate much smaller particle sizes. / Thesis (M.Sc. Engineering Sciences (Chemical and Minerals Engineering))--North-West University, Potchefstroom Campus, 2012.
56

Att leva med ärftligt ökad risk för bröstcancer / Living with increased hereditary risk of breast cancer

Rydelius, Fredrika, Sundström, AnnCharlotte January 2008 (has links)
<p><strong>BAKGRUND</strong>: Bröstcancer är allmänt känt i samhället, men få känner till den ärftliga aspekten av bröstcancer. Genom ett blodprov kan vårdpersonal påvisa om kvinnor har en genmutation, som ger ökad risk för bröstcancer, eller inte.</p><p><strong>SYFTE</strong>: Syftet med studien är att beskriva kvinnors upplevelser av att leva med ärftligt ökad risk för bröstcancer.</p><p><strong>METOD</strong>: En kvalitativ litteraturstudie där 14 vetenskapliga artiklar har analyserats.</p><p><strong>RESULTAT</strong>: Kvinnorna som lever med ärftligt ökad risk för bröstcancer lever med en ständig oro och osäkerhet. Varje kvinna är unik och hennes erfarenheter är därav individuella. Trots denna individualitet kan vissa mönster identifieras. De mest framstående ämnesområdena är oro och osäkerhet samt svårighet att hantera hotet.</p><p><strong>DISKUSSION</strong>: Kvinnorna med ärftligt ökad risk för bröstcancer ser till familjens bröstcancererfarenheter vid hantering av den egna situationen. Detta är relevant för all vårdpersonal då det är av vikt att förstå patienten och hennes unika situation.</p> / <p><strong>BACKGROUND</strong>: Breast cancer is commonly known through out the society, but few people are aware about the hereditary aspect of breast cancer. Through a blood test the healthcare professionals can determine if women have a genetic mutation, that increase the risk of getting breast cancer, or not.</p><p><strong>PURPOSE</strong>: The purpose of this study is to describe women's experience of living with an increased hereditary risk of breast cancer.</p><p><strong>METHOD</strong>: A qualitative literature study where 14 scientific articles were analysed.</p><p><strong>RESULT</strong>: Women who live with an increased hereditary risk of breast cancer live under constant worry and uncertainty. Each woman is unique and her experience is therefore very individual. Despite this individuality certain key point can be identified. The most distinguished subject areas are anxiety and uncertainty together with difficulty to handle the threat.</p><p><strong>DISCUSSION</strong>: Women with increased hereditary risk of breast cancer see to their family's breast cancer history when dealing with their own situation. This is important for all medical staff due to the importance of understanding the patient and her unique situation.</p>
57

Percepções de riscos e estratégias para gerenciá-los em agroindústrias familiares

Foguesatto, Cristian Rogério January 2016 (has links)
As atividades agroindustriais familiares destacam-se como alternativas econômicas, podendo ter papel relevante para os agricultores familiares que não obtêm resultados financeiros considerados satisfatórios apenas com as atividades agrícolas. Entretanto, existem inúmeros riscos que podem afetar negativamente essas organizações, tanto em seu ambiente interno, quanto no externo. Nesse sentido, a pesquisa foi conduzida com o objetivo de analisar as percepções de riscos e as estratégias adotadas para gerenciá-los dos tomadores de decisões das agroindústrias familiares no estado do Rio Grande do Sul - RS. Com esta finalidade, os dados foram coletados por meio da aplicação de questionários via e-mail, em feiras locais e em visitas nas próprias agroindústrias familiares, resultando em uma amostra de 72 respondentes. Os dados foram analisados utilizando estatística descritiva, analise fatorial, teste Kruskal-Wallis e o teste de Dunn. Os resultados apresentam as características dos tomadores de decisões e das unidades de produção familiares e mostram que 62,5% da amostra estudada destacam como principal motivação para a criação desse novo empreendimento, o aumento da renda agregando valor à matéria-prima. Além disso, 87% dos respondentes afirmam que a atividade agroindustrial evoluiu desde a sua criação. O estudo revelou a existência de três grupos de agroindústrias familiares, levando em conta a principal matéria-prima utilizada: animal, vegetal e misto. Nesse contexto, criou-se a sigla MPPM para evidenciar as matérias-primas do grupo misto. Os resultados demonstram que os as fontes de riscos consideradas mais relevantes pelos respondentes foram: situação econômica do país, inflação/deflação e a variação do preço do produto produzido. As estratégias de gestão mais importantes foram: manter-se informado sobre novas tecnologias, utilizar informações de assistência técnica e manter liquidez adequada (produto final). Por fim, entende-se que esses resultados auxiliam os tomadores de decisões destes estabelecimentos e, para o desenvolvimento de políticas públicas nesse segmento. / The family agroindustrial activities are important economic alternatives primarily for family farmers who do not obtain satisfactory financial results only with agricultural activities. However, there are numerous risks that may adversely affect these organizations, both in internal and external environment. The objective of this study was to analyze the perceptional risks and strategies and how to manage them from the decision makers of family farms in the state of Rio Grande do Sul - RS. For this purpose, data were collected through e-mail questionnaires, at local fairs and visits in some family farms, resulting in a sample of 72 respondents. The data were analyzed using descriptive statistics, factor analysis, Kruskal-Wallis and Dunn test. The results brough up decision makers characteristics and family production units and indicate that 62.5% of the studied population had primary motivation for the creation of this new venture, increased income adding value to raw materials. In addition, 87 % of the sample said that the agroindustrial activity has evolved since its inception. The study revealed the existence of three groups of family agroindustries, taking into account the main raw material: animal, vegetable and those using animal and vegetable (mix). It was created the abbreviation MPPM to highlight the raw materials of the mix group. The results show that the risks from sources considered most important by respondents were: economic situation of the country, inflation / deflation and the change in the price of the product produced. The most important management strategies were: to stay informed about new technologies, using technical assistance information and maintain adequate liquidity (final product). Finally, these results help decision makers of these establishments and for the development of public policies in this segment.
58

Percepções de riscos e estratégias para gerenciá-los em agroindústrias familiares

Foguesatto, Cristian Rogério January 2016 (has links)
As atividades agroindustriais familiares destacam-se como alternativas econômicas, podendo ter papel relevante para os agricultores familiares que não obtêm resultados financeiros considerados satisfatórios apenas com as atividades agrícolas. Entretanto, existem inúmeros riscos que podem afetar negativamente essas organizações, tanto em seu ambiente interno, quanto no externo. Nesse sentido, a pesquisa foi conduzida com o objetivo de analisar as percepções de riscos e as estratégias adotadas para gerenciá-los dos tomadores de decisões das agroindústrias familiares no estado do Rio Grande do Sul - RS. Com esta finalidade, os dados foram coletados por meio da aplicação de questionários via e-mail, em feiras locais e em visitas nas próprias agroindústrias familiares, resultando em uma amostra de 72 respondentes. Os dados foram analisados utilizando estatística descritiva, analise fatorial, teste Kruskal-Wallis e o teste de Dunn. Os resultados apresentam as características dos tomadores de decisões e das unidades de produção familiares e mostram que 62,5% da amostra estudada destacam como principal motivação para a criação desse novo empreendimento, o aumento da renda agregando valor à matéria-prima. Além disso, 87% dos respondentes afirmam que a atividade agroindustrial evoluiu desde a sua criação. O estudo revelou a existência de três grupos de agroindústrias familiares, levando em conta a principal matéria-prima utilizada: animal, vegetal e misto. Nesse contexto, criou-se a sigla MPPM para evidenciar as matérias-primas do grupo misto. Os resultados demonstram que os as fontes de riscos consideradas mais relevantes pelos respondentes foram: situação econômica do país, inflação/deflação e a variação do preço do produto produzido. As estratégias de gestão mais importantes foram: manter-se informado sobre novas tecnologias, utilizar informações de assistência técnica e manter liquidez adequada (produto final). Por fim, entende-se que esses resultados auxiliam os tomadores de decisões destes estabelecimentos e, para o desenvolvimento de políticas públicas nesse segmento. / The family agroindustrial activities are important economic alternatives primarily for family farmers who do not obtain satisfactory financial results only with agricultural activities. However, there are numerous risks that may adversely affect these organizations, both in internal and external environment. The objective of this study was to analyze the perceptional risks and strategies and how to manage them from the decision makers of family farms in the state of Rio Grande do Sul - RS. For this purpose, data were collected through e-mail questionnaires, at local fairs and visits in some family farms, resulting in a sample of 72 respondents. The data were analyzed using descriptive statistics, factor analysis, Kruskal-Wallis and Dunn test. The results brough up decision makers characteristics and family production units and indicate that 62.5% of the studied population had primary motivation for the creation of this new venture, increased income adding value to raw materials. In addition, 87 % of the sample said that the agroindustrial activity has evolved since its inception. The study revealed the existence of three groups of family agroindustries, taking into account the main raw material: animal, vegetable and those using animal and vegetable (mix). It was created the abbreviation MPPM to highlight the raw materials of the mix group. The results show that the risks from sources considered most important by respondents were: economic situation of the country, inflation / deflation and the change in the price of the product produced. The most important management strategies were: to stay informed about new technologies, using technical assistance information and maintain adequate liquidity (final product). Finally, these results help decision makers of these establishments and for the development of public policies in this segment.
59

Hur en ökad kunskap om kabelns mätmetoder kan leda till materialbesparing och därigenom kostnadsoptimering samt ökad produktivitet : En fallstudie inom NKT High Voltage Cables

Karlsson, Emmy, Suljeva, Arijeta January 2017 (has links)
I dagens tillverkningsindustri ställs det allt högre krav på produkter av hög kvalité med lägsta möjliga produktionskostnad. För att som producerande industri kunna tillmötesgå dessa krav krävs det att produktionsprocessen optimeras och därigenom sänker kostnaderna. Samtidigt ställs det allt högre krav på tillverkningsindustrin från samhället, en minimal materialförbrukning gentemot förbrukningskraven leder till en ökad hållbar utveckling. För att kunna uppnå visionen av en optimerad produktionsprocess blir kvalitetskontroll idag allt viktigare för industrierna. Målet är att uppnå en produkt av hög kvalité, fri från betydelsefulla variationer och därigenom tillgodose kundens behov eller än hellre överträffa kundens förväntningar på produkten, samtidigt som tillverkningsprocessen är optimerad till små marginaler. Syftet med det här arbetet är därför att bidra med en ökad kunskap om kvalitetskontroll inom produktionsprocessen och några av de vanligaste mätmetoder som används idag. Samt undersöka om en ökad kunskap kan möjliggöra för en optimering av produktionsprocessen genom en produktion med minskade marginaler. Arbetet utförs med en förhoppning om att denna optimering sedan kan leda till en rad fördelar för både den tillverkande industrin men även för samhället, dels genom en reducerad materialanvändning och därigenom en kostnadsoptimering, men även en produkt med optimerade dimensioner som därigenom kan tillverkas effektivare och höja processens produktivitet. Examensarbetet är upplagt som en fallstudie i samarbete med NKT HVC. Mätdata från tillverkningsprocessen har studerats för att upptäcka variationer och samband mellan de olika mätmetoderna. Två produktionslinjer har beaktats i studien. All mätdata från de båda linjerna behandlar en likvärdig produkt.  Resultatet av den empiriska studien indikerar på att det finns möjligheter för en optimering inom produktionsprocessen då det finns skillnader mellan kvalitetskontroll utfört med olika mätinstrument. En ökad kunskap är därför väsentligt för att kunna säkerhetsställa vilken mätmetod som stämmer bäst överens med verkligheten och därigenom kunna optimera processen med en reducerad materialförbrukning och därigenom en kostnadsoptimering samt en ökad produktivitet som resultat. / Today's manufacturing industry places increasingly high demands on high quality products with the lowest possible production cost. To be able to meet these requirements in production, it is necessary to optimize the production process and thereby lowering the costs. At the same time, increasing demands are being made on the manufacturing industry from the community, a minimal material consumption versus the consumption demands leads to sustainable development. In order to achieve the vision of an optimized production process, quality control today becomes increasingly important for the industries. The goal is to achieve a high-quality product, free from significant variations, and thereby meeting the customer needs or even exceeding the customer´s expectations of the product, while at the same time optimizing the manufacturing process to small margins. The purpose of this work is therefore to contribute to increased knowledge of quality control in the production process and some of the most common measurement methods used today. As well as investigating whether increased knowledge can enable an optimization of the production process through production with reduced margins. The work is carried out with the hope that this optimization can lead to several advantages for both the manufacturing industry but also for society, partly through reduced material usage and thus cost optimization, but also a product with optimized dimensions that can thereby be made more efficient and increase the productivity of the process. The Master thesis is done as a case study in cooperation with NKT HVC. Measurement data from the manufacturing process have been studied to detect variations and relationships between the different measurement methods. Two production lines have been considered in the study. All measurement data from the two lines treats an equivalent product. The result of the empirical study indicates that there are opportunities for optimization in the production process as there are differences between quality control performed with different measuring instruments. An increased knowledge is therefore essential in order to ensure which measurement method that fits best with reality, and thus be able to optimize the process with a reduced material consumption and thereby a cost optimization and increased productivity as a result.
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Methodik zur Bewertung von Maßnahmen zur Steigerung der Energieeffizienz der Innenraumklimatisierung von Personenkraftwagen unter ökologischen und wirtschaftlichen Aspekten

Freese, Bastian 08 August 2019 (has links)
Der zunehmende Ausstoß von Treibhausgasen gilt als wahrscheinlichste Ursache für die beschleunigte Erwärmung des weltweiten Klimas in den vergangenen Dekaden [1]. Zur Begrenzung des Temperaturanstiegs auf maximal 2°C im Vergleich zum vorindustriellen Niveau wurden weltweit Ziele zur Reduktion der Kohlenstoffdioxidemissionen definiert. Maßnahmen zur Effizienzsteigerung im Klimatisierungssystem von Personenkraftwagen können hierzu einen doppelten Beitrag leisten. Zum einen wird der Gesamtenergiebedarf der Fahrzeuge reduziert. Zum anderen kann die Realreichweite elektrifizierter Fahrzeuge erhöht und damit die Marktdurchdringung der Elektromobilität gefördert werden. Ein entscheidendes Hindernis bei der Umsetzung von Effizienzmaßnahmen im Klimatisierungssystem ist das Fehlen einer vereinheitlichten Methodik zur Bewertung der Emissionseinflüsse [3] sowie der finanziellen Auswirkungen für Endkunden und die Automobilindustrie in den weltweiten Vertriebsmärkten. Im Rahmen der vorliegenden Arbeit wird eine solche Bewertungsmethodik entwickelt und das Emissionsvermeidungspotential von aktuell diskutierten Maßnahmen abgeleitet. Die Methodik kombiniert ein thermisches Kabinenmodell und ein vereinfachtes Modell des Klimatisierungssystems mit statistischen Daten zum lokalen Klima, dem lokalen, tageszeitabhängigen Mobilitätsverhalten und Daten der lokalen Energiemärkte (Preise und Emissionsintensitäten). Die Methodik betrachtet dabei jeweils fünf Karosserietypen und sechs Antriebssystemtypen für 61 Orte weltweit. Zur Bewertung von Kundenakzeptanz und Umsetzungsquoten der Maßnahmen wird als statistische Größe der relative Umsetzungsfaktor entwickelt. Er setzt sowohl die Emissionsbilanz als auch die Kostenbilanz für Kunden ins Verhältnis zur Schwankung der Werte in den einzelnen Vertriebsmärkten. Daraus werden eine Empfehlung zum Angebotsszenario und eine Abschätzung von Ausstattungsquoten abgeleitet. Auf Grundlage dieser Ergebnisse kann das weltweite Emissionsvermeidungspotential von einzelnen Maßnahmen oder Maßnahmenpaketen abgeschätzt werden. Eine Untersuchung von 20 aktuell diskutierten Maßnahmen zeigt, dass sich das aus dem 450-Szenario der IEA abgeleitete Reduktionsziel von jährlich 27 MtCO2 nicht ohne zusätzliche Kosten für Endkunden oder Automobilhersteller erreichen lässt. Die Emissionsvermeidungskosten sind mit 154 EUR/tCO2 jedoch deutlich geringer als für viele aktuell bereits umgesetzte Maßnahmen. Durch geschickte Anreizsysteme seitens der politischen Entscheidungsträger scheint daher eine Realisierung von großen Teilen des Potentials möglich.

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