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1
Bouma, Andrew Thomas. "Split-feed counterflow reverse osmosis for brine concentration". Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/118668.
Testo completoAbstract (sommario):
Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2018.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 73-77).
Brine concentration is a useful operation that allows for increased recovery ratios in water treatment systems, reduction of waste volumes, and the production of minerals from saline brines. As our world moves towards a more sustainable future, improvements in energy-efficient brine concentration will be important. While viable brine concentration technologies exist, current methods are often inefficient. In this thesis, a model is developed to simulate Counterflow Reverse Osmosis (CFRO), a membrane-based, pressure-driven brine concentration technology. Using this model, a single CFRO module is simulated and its performance characterized. Entropy generation within a single-stage system is analyzed, which provides insights for configuring and optimizing multistaged systems. Additionally, a parametric analysis of membrane parameters provides direction for the development of CFRO-specific membranes. Two existing configurations of CFRO are discussed, and compared with a new third configuration, split feed CFRO, which is presented for the first time here. Split feed CFRO systems are simulated and optimized to provide guidance for system design. A variety of multistage systems operating at a range of recovery ratios are simulated, and the results compared are with existing desalination and brine concentration technologies. Potential is shown for the maximum recovery ratio of RO systems to increase significantly when hybridized with split-feed CFRO brine concentration systems, while the energy requirements of these hybridized systems is similar to, or an improvement on, the expected performance of conventional RO systems operating at high pressures and the same conditions. A large reduction in energy usage when compared to commonly used evaporative brine concentrators is shown to be possible.
Funded by the Kuwait Foundation for the Advancement of Sciences (KFAS) Project No. P31475EC01
by Andrew Thomas Bouma.
S.M.
2
Muzanenhamo, Pharaoh Kudzaishe. "Assessing the effect of cone ratio, feed solids concentration and viscosity on hydrocyclone performance". Master's thesis, University of Cape Town, 2014. http://hdl.handle.net/11427/13325.
Testo completoAbstract (sommario):
Includes bibliographical references.In the mineral processing industry, comminution circuits contain slurries composed of a mixture of particles of varying degrees of liberation and size. Hydrocyclones are commonly used to classify these particles. If the classification stage is not efficient, both grinding and flotation cannot be optimised or operated efficiently. Ores that are mined in industry contain metals of varying specific gravity, which makes recovery of the desired metal challenging. This study focussed on the effect of the hydrocyclone spigot to vortex finder diameter ratio, termed as the cone ratio, solids concentration and viscosity on the classification of two dual density ores. The rheological characteristic of the overflow was also evaluated. A UG2 ore (Upper Group), which consists mainly of silicates, and chromite, and an iron ore, containing mainly iron and silicates, were used as feed material. The UG2 test work was carried out on a University of Cape Town (UCT) 4 inch Multotec cyclone, while the iron ore test work was carried out on an Anglo-American 4 inch Krebs cyclone. The cyclone performance was assessed using the corrected cut size, water recovery to the underflow, sharpness of separation and feed throughput. The rheological characterisation of both the UG2 and iron ore were carried out using an AR (ARES-G2) 1000EX vane rheometer. The results obtained indicated that the cyclone cone ratio, feed solids concentration and viscosity influence the cyclone performance. For the UG2 it was observed that as the cone ratio increased the cut size decreased and levelled off at a cone ratio of 1. However, for the iron ore it was observed that the cut size increased with an increase in the cone ratio, until it reached a peak at a cone ratio of approximately 0.68, before decreasing. The water recovery to the underflow increased with cone ratio and solids concentration and for both ore types. However it was observed that the water recovery was more sensitive to the cone ratio within the range of conditions investigated. The sharpness of separation for the UG2 ore increased with cone ratio for all solids concentrations investigated and reached a peak at a cone ratio of approximately 1 then decreased. The sharpness of separation for the iron ore illustrated different trends at different feed solids concentration. Between 10 and 20 wt. % feed solids concentration the sharpness of separation for iron ore was fairly constant, while at 50 wt. % solids concentration the sharpness of separation increased with cone ratio and then levelled off at a cone ratio of 0.67. An increase in the volumetric throughput with cone ratio was observed for both ore types. Rheological characterization revealed Bingham plastic behaviour for both ore types. An increase in the feed viscosity led to an increase in the cut size, water recovery and sharpness of separation for both UG2 and iron ore. A comparison of the results with a semi mechanistic model revealed a good fit for the volumetric throughput, water recovery and viscosity. However, the sharpness of separation and cut size had more scatter. The standard error for the sharpness of separation model fit was 21% for UG2 and 23% for iron ore while the error for the cut size was 41 % for the UG2 ore and 43 % for the iron ore. It was recommended that for future work, test work should be carried at a constant pressure in order to assess purely the effect of cone ratio. Furthermore, a coarser ore should be used in order to evaluate the effect of cone ratio and feed viscosity on the individual deportment of the prevalent components in the dual density ore types investigated by carrying out assays.
3
Ali, Johar. "Performance, tissue selenium concentration and glutathione peroxidase activity as response variables for determining selenium requirements of poultry /". free to MU campus, to others for purchase, 2000. http://wwwlib.umi.com/cr/mo/fullcit?p9999267.
Testo completo
4
Ribeiro, Claudio Vaz Di Mambro. "Determining the factors that cause higher concentration of conjugated linoleic acid (CLA) in milk fat of dairy cows fed fresh alfalfa versus alfalfa hay". Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1117551699.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xviii, 141 p.; also includes graphics (some col.) Includes bibliographical references (p. 116-130). Available online via OhioLINK's ETD Center
5
Anh, Viet Bui, of Western Sydney Hawkesbury University, of Science Technology and Environment College e of Science Food and Horticulture School. "A study of osmotic distillation in hollow fibre modul". THESIS_CSTE_SFH_Anh_V.xml, 2002. http://handle.uws.edu.au:8081/1959.7/4.
Testo completoAbstract (sommario):
Osmotic distillation is a process of removing water from an aqueous solution, driven by water vapour pressure gradient across a hydrophobic membrane. The process occurs at or below ambient temperature and under atmospheric pressure. This research project investigates the osmotic distillation process in hollow fibre modules using hollow fibres PP375, PV375 and PV660 supplied by Memcor Australia. Operating conditions such as temperature, feed concentration and brine cross flow velocity, but not the feed cross flow velocity, were found to have significant effect on the flux. Models for heat and mass transfers were used to study the polarisation phenomena in osmotic distillation. Temperature and concentration profiles at the membrane surfaces due to polarisation were quantified. Scholfield and Ordinary Diffusion models for flux prediction based on the bulk conditions were developed and validated. Models for water activity and viscosity of aqueous glucose and calcium chloride solutions were also developed and validated in this work.Master of Science (Hons)
6
Åkerlind, Maria. "Milk composition and metabolism of cows selected for high or low milk-fat concentration /". Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1999. http://epsilon.slu.se/avh/1999/91-576-5702-5.pdf.
Testo completo
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Mostert, Louma. "Feed intake and performance of Hubbard Flex broilers with varying dietary energy and protein concentrations". Diss., University of Pretoria, 2015. http://hdl.handle.net/2263/53532.
Testo completoAbstract (sommario):
Broiler breeding companies continue to analyse the recommended nutrient levels of broiler diets due to the short production cycle and continuous genetic development of broilers. Modern broilers reach marketable weights very early, often at an immature body weight and without achieving maximum genetic potential in terms of absolute quantities, for example daily growth. As broilers age, their daily feed intake increases and nutrients are deposited in body tissue, mainly as protein and fat. An imbalance of energy or protein cause for excess fat deposited in carcasses due to excessive feed intake to satisfy a nutritional requirement. The cost of feed contributes substantially to the total production expenses, with energy alone contributing approximately 70% of the total cost of poultry diets. Therefore, the focus of feed companies remain to determine the energy and protein requirements of broilers, in order to feed a balanced diet, delivering a bird with an optimal carcass composition.
Two experiments of identical design were conducted in floor pens to evaluate the effect of metabolisable energy levels as well as crude protein levels on broiler performance. The first trial was an energy dose-response trial and the second trial a protein dose-response trial. Each study was conducted over a period of five weeks where five thousand seven hundred and sixty Hubbard Flex (mixed sex as hatched) broilers were housed in 60 pens. Ninety six (96) chicks were randomly allocated in a pen at a stocking density of 16 birds/m2. Each treatment was repeated once within a block, totalling to 10 replications/treatment. Water and feed were provided ad libitum.
In the energy dose-response experiment two iso-protein basal feeds were formulated and manufactured, one containing a high energy (HE) level, the other a low energy (LE) level. These basal diets were further diluted into four diets containing various percentages of energy (80% LE: 20% HE; 60% LE: 40% HE; 40% LE: 60% HE and 20% LE: 80% HE). The crude protein and amino acid balance was kept constant across all treatments. Six dietary treatment combinations were implemented in a 4-phase feeding programme: Pre-starter (0 to 10 d), Starter (11 to 18 d), Grower (19 to 28 d) and Finisher (29 to 35 d of age). Body weight (BW) and average daily gain did not show any significant difference between LE and HE treatments. A weekly numerical difference was recorded for BW between LE and HE treatments; where birds fed the HE diet weighed heavier on Day 35, at 1939.97 g compared to the 1898.10 g of birds fed the LE diet. FI increased as the energy concentration increased from the LE to HE treatments; and although the differences in FI was non-significant (NS), birds fed HE diets consumed 2882.11 g/bird by Day 35 and birds fed LE diets, only consumed 2830.90 g/bird in total. No significant difference was recorded for cumulative feed conversion ratio (CFCR) among treatments by Day 35 and birds fed the LE diet ended with 1.53 points compared to 1.52 points for birds fed HE diet. Despite the dietary energy increase in energy level from the LE diet to the HE diet, there was no significant effect on daily mortalities; birds fed the LE diet showed 5.10% mortality compared to 5.41% mortality for birds fed the HE diet.
In the protein dose-response trial two isocaloric basal feeds were formulated and manufactured, one containing a high protein (HP) level, the other a low protein (LP) level. These basal diets were further diluted into 4 diets containing various percentages of protein (80% LP: 20% HP, 60% LP: 40% HP, 40% LP: 60% HP and 20% LP: 80% HP). The dietary metabolisable energy (ME) was kept constant across all treatments. Birds fed the HP diet showed the greatest BW at Day 21 with 900.97 g compared to birds fed the LP diet on 858.85 g; and weighed 1937.48 g at Day 35 compared to 1869.80 g for birds fed LP diet. Cumulative feed intake (CFI) decreased as the protein content in the feed increased. Although the results from Day 28 only approached significance, birds fed the HP diet consumed significantly less feed (2840.29 g/bird) than birds fed the LP diet (2913.66 g/bird) by Day 35. CFCR for HP was 1.50 points by Day 35 compared to 1.59 points for LP. The increase in protein content from LP to the HP diet, did not cause a significant increase in mortalities; although a numerical increase can be seen of 6.24% for birds fed on the LP diet compared to 9.06% mortality in birds fed the HP diet.Dissertation (MSc)--University of Pretoria, 2015.
Animal and Wildlife Sciences
MSc
Unrestricted
8
Smoler, Eliezer. "Mathematical models to predict milk protein concentration from dietary components fed to dairy cows". Thesis, University of Reading, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308060.
Testo completo
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Abidin, Shamharir. "Audit market concentration and auditor choice in the UK". Thesis, University of Stirling, 2006. http://hdl.handle.net/1893/119.
Testo completoAbstract (sommario):
Auditing has an important role in the corporate governance process and is essential in ensuring confidence in the reliability of financial information. It is important to understand the reasons why, given the costs involved, companies change their auditor and choose a particular level of audit assurance. To date, however, only a limited number of studies on auditor choice issues are available, especially in the UK setting. Further, since the downfall of Andersen, the audit market environment has changed significantly, creating a new audit environment to be researched. In light of these recent developments, the objectives of this thesis are to address both concentration and auditor choice issues. It is divided into two separate but interrelated parts. The first part of this thesis provides evidence on audit market concentration in the UK domestic listed company market from 1998 to 2003. The effect of Andersen’s demise on both audit market concentration and audit fees is examined. Using four different size measures (number of audits, audit fees, clients’ total assets and sales), three measures of concentration are calculated. Results show that the UK audit market has now clearly surpassed the tight oligopoly threshold and, despite auditing significantly fewer clients in 2003 than in 1998, the B5/4 managed to increase their fee dominance. In particular, the decline in B5/4 ‘number of clients’ market share was mainly due to their lower share of the newly-listed companies audit market. On the other hand, the slight increase in B5/4 audit fee market share was due to the net impact of leavers concentrating the B5/4 share and joiners diluting it. Voluntary switches to/from the B5/4 had a relatively small impact on B5/4 market share for both measures. Following Andersen’s acquisition by Deloitte & Touche, market levels of audit fee and audit fee rate (audit fee scaled by total assets) have increased markedly, suggesting that more audit effort is being expended as a way to restore confidence about audit quality after the damage caused by Andersen’s alleged misconduct. The acquisition has also contributed to a further increase in ‘audit fee’ market concentration for the 4-firm concentration ratio (CR4) and in the overall Hirschman-Herfindahl Index measure. Although, Deloitte & Touche gained significant market share in terms of both audit fees and number of audits through its acquisition of Andersen, it is PricewaterhouseCoopers that continues to hold the largest market share. Deloitte & Touche retained 93 former Andersen clients (74%), 21 (17%) moved to another B5/4 auditor and 11 (9%) chose a non-B5/4 firm. While former Andersen clients paid higher audit fees, in aggregate, the increase was, perhaps surprisingly, less than for the market as a whole. At the industry level, the B4 firms dominated all sectors, the highest non-B5/4 market share in any industry being just 8%. In 2003, PricewaterhouseCoopers was the leader in 18 out of 34 sectors. The second part of the thesis is divided into two separate studies – auditor change determinants and new auditor selection determinants. These studies use a sample of non financial auditor change companies to test logistic regression models of the determinants of auditor change and new auditor selection. The determinant variables include auditee, auditor and audit characteristics. This part also examines the sensitivity of results to alternative functional forms of the basic model specification. Two definitions of auditor quality – brand name auditor and specialism, are employed. Internal governance issues such as audit committee independence, the duality of chairman/CEO as well as the size/quality of the incumbent auditor were found to be significant determinants of auditor change. Expected future growth in the company, rather than past growth, and audit fee reduction were positively related to audit change probability. Result also suggests that companies changed auditor to improve the perception of auditor independence. By contrast, in the new auditor selection models, corporate governance variables did not appear to be important in determining a different quality (brand-name) auditor. Only the chairman/CEO duality variable was weakly and negatively significant, suggesting that duality is associated with a change to a lower quality auditor. Growing companies are more likely to change to a brand name auditor, consistent with the inability of smaller firms to provide services across an international market. Contrary to agency theory predictions, the results show that a company experiencing increased leverage is less likely to choose a B5/4 auditor, suggesting that B5/4 auditors are being selective in avoiding risky clients. Higher audit fees are paid to new auditors by companies that changed from non-B5/4 to B5/4, reflecting a B5/4 fee premium. However, the higher NAS fee result is contrary to initial expectations. Typically, far fewer variables were significant in the models with audit quality proxied by industry specialism. For the specialism models based on audit fee market share, there is counter-intuitive evidence that a company with a large number of subsidiaries is less likely to move to a specialist auditor from a non-specialist. New specialist auditors were more likely to be preferred when a company experienced an increase in current accruals or a reduction in leverage. In general, the results for these models were less strong and were dependent upon the specialist definition adopted. Finally, the thesis provides evidence that the choice of time variant model (ex-ante, contemporaneous or ex-post) made no significant difference to the overall results. The one exception concerns the ‘growth’ variable, where companies are found to change auditor in anticipation of future growth, rather than as a response to past growth. Further, the use of alternative proxy variables does not greatly influence the regression results. One important exception to this general observation concerns the brand name proxy. When brand name was defined as tier12 (to include Grant Thornton and BDO) the significance level was improved in all models. This suggests that, to some degree, Grant Thornton and BDO are viewed as quality service providers closer in quality to B5/4 than to other smaller audit firms.
10
Davis, Michael Patrick Kerley Monty Stephen. "Influence of diet, production traits, blood hormones and metabolites, and mitochondrial complex protein concentrations on residual feed intake in beef cattle". Diss., Columbia, Mo. : University of Missouri--Columbia, 2009. http://hdl.handle.net/10355/7034.
Testo completoAbstract (sommario):
Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 26, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dissertation advisor: Monty Kerley. Vita. Includes bibliographical references.
11
Lamar, Kathryn C. "Effects Of Dietary Potassium Carbonate And Fat Concentration in High Distiller Grain Diets Fed To Dairy Cows". The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1374228532.
Testo completo
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Homerosky, Elizabeth Rose. "Fatty acid digestibility of fat sources fed to dairy cows and effects on concentration of fat in milk". Connect to resource, 2008. http://hdl.handle.net/1811/31807.
Testo completo
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Trbovich, Victoria R. "The Effects of Sous Vide Cooking on Tenderness and Protein Concentration in Young Fed Beef and Cow Semitendinosus Muscles". The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1511910815944282.
Testo completo
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May, Amy. "Audit market concentration, auditor switching and audit fee pricing : an investigation of the UK private company audit market, 2005-2012". Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/16012/.
Testo completoAbstract (sommario):
Statutory audit markets across the EU have recently been reformed, with new Regulation on the Statutory Audits of Public Interest Entities coming into force in June 2016. The Regulation imposes stricter requirements on the audits of Public Interest Entities, as originally defined in the Statutory Audit Directive 2006, with the option for Member States to designate additional entities as public interest. Thus, the exact definition of a Public Interest Entity applied varies across Member States. In the UK the definition has not been widely extended and includes listed firms, credit institutions, and insurance undertakings. Private firms in the UK are therefore currently exempt from the more stringent audit regulations. However, even based on the limited, and often mixed, evidence for the private company audit market, the decision to preclude most private companies from the definition of a Public Interest Entity, effectively excluding them from the new audit reforms, may not be appropriate. This thesis, therefore, undertakes a comprehensive analysis of the UK audit market for private companies, in addition to examining the auditing choices of private companies and the economic consequences of these choices. The UK is specifically examined because it is one of a number of countries that have chosen not to extend the scope of the definition of a Public Interest Entity beyond the one set at the EU level. The findings of this research show that, similar to the audit market for listed firms, the private company audit market in the UK is segmented with Big Four dominance among the largest firms and relatively low levels of auditor switching. As a result of this audit environment, private companies that do switch auditor are found to experience economic consequences in terms of a reduction in their credit ratings. Particularly when the reasons for a switch are unknown to investors. In addition, the thesis provides evidence to suggest that following an auditor switch, firms receive both physical and implicit discounts on their audit fees, with price recovery of these discounts over the following three years. Suggesting that low-balling is also present in this audit market, which in turn raises concerns regarding competitive pricing and levels of auditor independence. In sum, the results of the thesis provide strong support that the definition and scope of a Public Interest Entity needs revisiting both within the UK and across all EU Member States. Moreover, it reinforces the idea of extending some of the more stringent audit requirements introduced by the EU Regulation on the Statutory Audits of Public Interest Entities, to ensure that economically important private firms have sufficient oversight.
15
Robinson, Julie A. "The effects of dietary molybdenum and sulfur on serum copper concentrations, growth and reproductive function in lambs". Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/31319.
Testo completoAbstract (sommario):
Feeds often contain molybdenum (Mo) and sulfur (S) in excess of recommended allowances for adequate copper (Cu) absorption by ruminant livestock. Two randomized-block experiments were conducted using lambs given a cereal-based diet (90% of dry matter (DM) intake), containing 8 mg Cu, 0.7 mg Mo and 2.1g S per kg DM, that was either unsupplemented or supplemented with ammonium molybdate or sodium sulfate alone or in combination, to determine the effects of Mo, S and Mo+S on growth, hematology, serum Cu and Mo concentrations and reproductive function.
Short term intake (4 weeks) by rams, aged 18 and 20 weeks, of 26 mg Mo alone or in combination with 2g S per kg DM, had no effect on growth, hematology or the concentration of total Cu in serum (TCu). However, supplemented groups had lower (P<0.05) concentrations of serum Cu soluble in trichloroacetic acid (TCA-Cu), but the group given Mo+S had the highest (P<0.05) concentration of serum residual Cu (RCu). Luteinizing hormone (LH) peak amplitude was affected by age*diet interaction (P<0.05), because of high amplitude LH peaks in the serum of lambs, aged 24 wks, given Mo alone. Testosterone serum secretory profiles did not differ among diet groups, but testosterone peak frequency was higher (P<0.05) for older ram lambs.
Long term intake (32-39 wks) by ewe, ram and wether lambs (gonadal influence) of 12 mg Mo, or 2g S alone or combined per kg DM also had no effect on hematology or TCu. Food intake and liver weights were higher (P<0.05), but TCA-Cu was lower (P<0.05) for groups given S. Serum concentrations of total Mo (TMo) were higher (P<0.05) for Mo-supplemented groups, but RCu was highest only for the Mo+S group. Growth was affected by Mo*S*gonadal influence*time interaction (P<0.05); until autumn, the body weight of Mo-supplemented groups were higher than those of ram and wether lambs given Mo+S. Ovarian or testicular functions were delayed more severely for Mo- than Mo+S-supplemented groups. Mean concentrations of LH were affected by Mo*S*gonadal influence*time interaction (P<0.05); the mean LH values of Mo-supplemented ram and ewe lambs were higher than the Mo+S-supplemented
group, whereas a reverse trend was observed for wether lambs. The amplitude of LH peaks was affected by Mo*S*gonadal influence*time interaction (P<0.05); for ram lambs, LH peak amplitude was higher for Mo than Mo+S-supplemented groups, whereas for wether and ewe lambs the reverse trend was noted. Mean concentrations of serum Cortisol and Cortisol peak amplitude were affected by Mo*S interaction (P<0.05); the mean Cortisol concentration and peak amplitude for the Mo-supplemented group were higher than those for the Mo+S-supplemented group. The frequency of LH and Cortisol peaks did not differ (P>0.10) among diet groups.
In conclusion, Mo supplementation of cereal-based diets containing a high concentration of Cu did not adversely affect lamb growth. However, the effect of high dietary Mo on reproductive function appears to depend on the dietary level of S and the induction of high serum RCu (thiomolybdate). Further investigations on the effects of Mo and thiomolybdate on endocrine function may provide a nutritional basis for improving reproductive efficiency in ruminants.Land and Food Systems, Faculty of
Graduate
16
Schell, Timothy C. "Supplementing weanling pigs with high concentrations of Zn and the Zn availability of Zn sources for weanling pigs". Diss., This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-09192008-063113/.
Testo completo
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Engström, Staffan. "Wind Farms Influence on Stability in an area with High Concentration of Hydropower Plants". Thesis, Uppsala universitet, Institutionen för fysik och astronomi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-158447.
Testo completoAbstract (sommario):
The number of large-scale wind farms integrated to the power system in Sweden is increasing. Two generator concepts that are widely used are Doubly-Fed Induction Generators (DFIG) and Full Power Converters (FPC). The study is of a quantitative character and the aim of the Master thesis is to compare DFIG-models with FPC-models integrated in an area with high concentration of hydropower. Then it is possible to examine how the dynamics in the power system change depending on the selection of technology (DFIG or FPC) when connecting a wind farm. The power system is simulated during a summer night, i.e., a low load is connected. The Master thesis covers stability analysis of the power system by using rotor angle stability that are split into small-signal stability and transient stability (time-domain simulations) and finally voltage stability to see how the hydropower generators react when varying the power production in the wind farm. The Master thesis concludes that independently of wind turbine technique, integration of a wind farm has slight impact on the stability in the power system compared to a power system without a wind farm, even though the load is low. Further, an integration of a wind farms affects the reactive power production in neighbouring hydropower plants. Finally, when increasing the size of the wind farm the neighbouring hydropower station consume less reactive power which can induce problem with the voltage stability.
18
Ribeiro, Claudio Vaz. "Determining the factors that cause higher concentration of conjugated linoleic acid (CLA) in milk fat of dairy cows fed fresh alfalfa versus alfalfa hay". The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1117551699.
Testo completo
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Shepherd, Dare Marie. "Interactions in Rumen Pool Characteristics by Dairy Cows Fed Two Concentrations of a Co-Product From Corn Wet Milling With Different Forage Sources". The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1345511766.
Testo completo
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Albuquerque, Juliane Nogueira de. "Produção de metano em AnSBBR tratando vinhaça em condição termofílica". Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-03082017-100654/.
Testo completoAbstract (sommario):
O tratamento de efluentes industriais gerados em elevadas temperaturas por meio da digestão anaeróbia termofílica aparece como opção para o controle da poluição ambiental e obtenção de bioenergia. Nesse sentido, este trabalho investigou o uso do reator anaeróbio termofílico contendo biomassa imobilizada e com agitação mecânica operado em batelada e/ou batelada alimentada sequenciais no tratamento da vinhaça visando a produção de metano. Foi verificada a influência do aumento da carga orgânica volumétrica aplicada e da estratégia de alimentação no desempenho do reator. O volume do meio líquido do reator foi de 2,3 L, sendo 1,3 L de volume residual e 1,0 L o volume de efluente a ser tratado por ciclo, mantendo-se constante a temperatura (55º C – faixa termofílica), o tempo de ciclo (8 horas) e a velocidade de agitação (100 rpm). Inicialmente foi realizada a adaptação da biomassa, em seguida foi avaliada a influência da carga orgânica volumétrica aplicada (6,5-25,9 gDQO.L-1.d-1) pelo aumento da concentração de matéria orgânica afluente, e por fim foi implementada a estratégia de alimentação por batelada alimentada. Na etapa do aumento da COVA foram alcançadas maiores produtividades molar (304 molCH4.m-3.d-1) e volumétrica (6828 mL-CNPT CH4L-1.d-1) de metano na COVA de 25,9 gDQO.L-1.d-1, com rendimento de metano por matéria orgânica consumida próximo ao valor teórico (15,6 mmol de CH4.gDQO-1) e remoção da matéria orgânica na forma de DQO entre 75-80 % nas condições com COVA acima de 14gDQO.L-1.d-1. Na etapa em que se modificou a estratégia de alimentação, as produtividades molar e volumétrica de metano foram de 351,9 molCH4.m-3.d-1 e 7888 mL-CNPT CH4.L-1.d-1, respectivamente, com rendimento de metano por matéria orgânica removida próximo ao valor teórico. A produção de energia foi de 25,1 MW e 30,3 MW nas condições em batelada e batelada alimentada, respectivamente. O modelo cinético permitiu o entendimento da influência da carga orgânica e da estratégia de alimentação sobre o desempenho do reator para geração de metano, analisando-se os coeficientes das reações de consumo/produção dos compostos envolvidos na rota metabólica.The thermophilic anaerobic digestion of wastewater that are generated at high temperatures appers as an option for the environmental pollution control and bioenergy production. Thus, this study investigate a anaerobic reactor containing immobilized biomass and mechanical stirrer operate in sequential batch or feed batch treating vinasse-based wastewater for methane production. It was analyzed the effects on reactor performance of increasing the applied volumetric organic load (AVOL) and modifying the feeding strategy. The total volume of liquid was 2,3 L, in which 1,3 L of residual volume and 1,0 L of wastewater to be treated per cycle, keeping constant the temperature (55 ºC – thermophilic range), the cycle length (8 hours) and the stirred velocity (100 rpm). At first it was realizes the biomass adaption, then it was analyzed the applied volumetric organic load (6,5-25,9 gDQO.L-1.d-1) increasing the influent concentration and after the feeding strategy was modified. In the AVOL increasing were achieved higher molar productivity of methane (304 molCH4.m-3.d-1) and volumetric productivity (6828 mL-CNTP CH4.L-1.d-1) at AVOL of 25,9 gDQO.L-1.d-1, and molar yield of methane per organic matter removed close to the theoretical value (15,6 mmolCH4.gDQO-1) and removal efficiency of organic matter in terms of DQO between 75-80% for all conditions above AVOL of 14 gDQO.L-1.d-1. In the stage of feeding strategy change, the methane molar and volumetric productivity were 351,9 molCH4.m-3.d-1 and 7888 mLCH4.L-1.d-1, receptively, and the yield methane production per removal organic matter close to the theoretical value. The energy production were 25,1 MW and 30,3 MW in the batch and fed batch conditions, respectively. The kinetic model allowed known of AVOL and feeding strategy influence under the reactor performance to methane generation, analyzing the reaction coefficient of the compounds consume/production involved in the metabolic rote.
21
Helen, Onyeaka. "Studies related to scale-up of high cell density Escherichia Coli fed-batch fermentations : effect of a changing micro-environment with respect to pH, glucose and oxygen concentration". Thesis, University of Birmingham, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.668327.
Testo completo
22
Lewis, Heidi A. "Minimum dietary fish oil requirement to maintain highly unsaturated fatty acid concentrations in the fillets of sunshine bass fed diets containing little or no fish meal /". Available to subscribers only, 2006. http://proquest.umi.com/pqdweb?did=1240701551&sid=11&Fmt=2&clientId=1509&RQT=309&VName=PQD.
Testo completo
23
Rossi, Johnny E. "Effects of dietary crude protein and energy concentration on performance, carcass characteristics, and carcass chemical composition in Feedlot Cattle fed to achieve step-wise increases in rate of gain /". The Ohio State University, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488202678773968.
Testo completo
24
Stinefelt, Beth M. "Uric acid as an antioxidant and the effect of changes in plasma uric acid concentrations on broiler susceptibility to ascites and the effect of diet and strain on growth, feed efficiency, and amino acid retention in hybrid bluegill /". Morgantown, W. Va. : [West Virginia University Libraries], 2003. http://etd.wvu.edu/templates/showETD.cfm?recnum=3021.
Testo completoAbstract (sommario):
Thesis (M.S.)--West Virginia University, 2003.Title from document title page. Document formatted into pages; contains vii, 88 p. : ill. (some col.). Includes abstract. Includes bibliographical references.
25
Ticona, Benique Eduardo. "Concentration of metabolites and behavior of live weight in llamas (Lama glama) fed with natural grass and barley during gestation, postpartum, and new born phases in Turco, department of Oruro". BYU ScholarsArchive, 2009. https://scholarsarchive.byu.edu/etd/5438.
Testo completoAbstract (sommario):
The llama, a potential socioeconomic resource in the Bolivian highlands, faces serious nutritional deficiencies during the gestational and postpartum stages that negatively affect production. This study was conducted at the Tika Huta Experimental Center in the Llachu community of the Oruro prefecture. Our objectives were to determine metabolite concentration in blood plasma as well as live weight performance of pregnant and postpartum female llamas. Adult and juvenile llamas were fed diets of either plain natural grass or natural grass combined with 0.4 kg of barley hay. In addition, we determined metabolite concentrations in blood plasma and live weight performance of newborns until three months of age. Ten newborn llamas and nine pregnant adult llamas were used. We collected 133 blood plasma samples from mothers and 57 blood plasma samples from newborns. The samples were sent to laboratories at Brigham Young University for analysis. Results showed the following metabolite concentrations in pregnant llamas: 7.23 ± 1.80 g/dl total proteins, 36.31 ± 1.32 mg/dl urea, 84.72 ± 3.58 mg/dl triglycerides, 55.89 ± 2.32 mg/dl cholesterol, and 7.11 ± 1.34 mg/dl creatinine. In newborn llamas, blood plasma metabolite concentrations were as follows: 7.20 ± 1.54 g/dl total proteins, 48.41 ± 1.30 mg/dl urea, 103.25 ± 2.60 mg/dl triglycerides, 89.09 ± 3.30 mg/dl cholesterol, and 2.39 ± 0.33 mg/dl creatinine. The average live weights were 76.82 ± 8.57 kg and 15.95 ± 2.47 kg for mothers and newborns, respectively. Animals fed diets of natural grass and barley hay yielded results with significant differences. It is recommended that llama diets be supplemented with barley hay during the first two months of gestation, the last third of gestation, and postpartum.
26
Obese, Frederick Yeboah. "Concentrations of insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3) in the plasma and milk of pasture-fed dairy cows in early lactation /". Connect to thesis, 2003. http://eprints.unimelb.edu.au/archive/00000549.
Testo completo
27
Jakubcová, Klára. "Analýza trhu PR agentur v ČR v letech 2013-2015". Master's thesis, Vysoká škola ekonomická v Praze, 2016. http://www.nusl.cz/ntk/nusl-262255.
Testo completoAbstract (sommario):
The work analyzes market of public relations in the Czech Republic in the period from 2013 to 2015 based on the available data. Data come from research for The Association of PR Agencies (APRA) and from the balance sheets of selected agencies. The main hypothesis says, there is a monopolistic competition on the Czech market of PR agencies, because there is homogenous product, a large number of agencies, no entry barriers and agencies don´t have market power. I tested the hypothesis by calculating the Concentration coefficient and the Herfindahl Hirschman Index. Both methods confirmed the main hypothesis of monopolistic competition in this market. Work also includes the TOP 10 of PR agencies in the Czech market according to turnovers. It shows that the largest agency in the 2013 was Bison & Rose and in 2014 and 2015 it was AMI Communications. I also compared the changes in income and in prices of services by agencies that are members of APRA. So I can say that between the period from 2013 to 2015 there was a 18% growth in income of agencies, which was caused by higher quality of orders and not by raising prices.
28
XIONG, LIM JASON TZE, e 林智雄. "Factors Influencing Concentration Polarization in NF Membranes – Ionic Charges, Feed Concentrations and Cross-Flow Velocities". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/cu884z.
Testo completoAbstract (sommario):
碩士朝陽科技大學
環境工程與管理系
106
Nanofiltration (NF) membrane processes have gained much attention over the past decades due to their selective rejection properties. The performance in relation to permeate flux and sulfate salt rejection under 4 bars constant transmembrane pressure of two commercial NF membranes (NF270 and NSK98) was examined in this study by varying the feed salt cation, cross-flow velocity and salt solution concentration. The concentration polarization effect encountered by the membranes was analyzed using the film theory and resistance-in-series model. Results showed that the permeability of the NF270 membrane was significantly higher than that of NSK98, which were 14.99 L/m²-hr-bar and 10.40 L/m²-hr-bar respectively. However, both membranes displayed high rejection of cations, in which sodium, magnesium and aluminum ion rejection rates were over 87%, 99.1% and 99.7%. Furthermore, NSK98 had a slightly higher rejection than NF270. The main rejection mechanisms of salt solutions were identified as steric hindrance, Donnan exclusion and dielectric exclusion. Increasing the cross-flow velocity resulted in higher permeate flux and salt rejections, which was due to enhanced shear rates, reducing the extent of concentration polarization. On the other hand, increasing the feed concentration lowered permeate flux and rejections, due to higher osmotic pressure difference on both sides of the membrane and accumulation of solutes on the membrane surface. The mass transfer of solutes during filtration was governed by concentration polarization, which was more prominent at lower cross-flow velocities and higher feed concentrations. The value of the mass transfer coefficient increased with increasing cross-flow velocities, reducing the thickness of the polarization layer. While fouling was negligible in all experiments conducted in this study, concentration polarization experienced by both membranes was speculated to be different. The higher flux of NF270 led to more solute accumulation on the membrane surface, which resulted in a higher concentration polarization modulus. The higher rejection of NSK98, coupled with its lower flux, enhanced solute back-diffusion, which resulted in a thicker, more resistant but less dense concentration polarization layer.
29
Weng, Chia-Hung, e 翁嘉鴻. "A Strategy of Estimating Fuel Concentration in a Direct Liquid-Feed Fuel Cell System". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/29051581460129896351.
Testo completoAbstract (sommario):
碩士北台科學技術學院
機電整合研究所
94
Fuel control is one of the most pressing topics to achieve a self-sustainable direct liquid-feed fuel cell system, such as a direct methanol fuel cell (DMFC), and enhance its overall efficiency. In a DMFC system, sensing the methanol concentration generally serves as the basis of the fuel control strategies. This thesis proposes the notion of three dimensional measurement spaces and constant concentration surfaces (CCS) to develop an algorithm for estimating fuel concentration in a liquid-feed system. In the thesis, two examples are illustrated to verify the validation and generality of the proposed algorithm that embraces the following merits: 1) It measures only three quantities or indices that are all easily acquired in an operating system. The estimation can be accomplished without interrupting the operation of the fuel cell system. 2) It possesses a 3-dimensional space in the corresponding feasible domains; hence it is suitable for situations that operating conditions are varying. 3) It is a sensor-less scheme that requires none of additional methanol sensors, thus consuming the system power as less as possible. 4) It is particularly suitable for small and hand-held applications.
30
Cochrane, Roger. "Interventional strategies to reduce biological hazards in animal feed". Diss., 2018. http://hdl.handle.net/2097/39014.
Testo completoAbstract (sommario):
Doctor of PhilosophyDepartment of Animal Sciences and Industry
Cassandra K. Jones
Porcine epidemic diarrhea virus (PEDV) is a heat-sensitive virus that devastated the United States swine industry. Because of its heat sensitivity, it was hypothesized that a pellet mill mimicking commercial thermal processing may mitigate PEDV infectivity. From the results, it was determined that a conditioning time of 30 sec or greater and temperatures above 54.4°C were effective point-in-time kill steps to inactive PEDV in a research setting. However, this does not prevent subsequent recontamination after pelleting as it is a point-in-time mitigation step. To further explore this, various mitigation additives were evaluated to prevent or mitigate PEDV post-pellet contamination in swine feed and ingredients. Various additives were examined across 3 experiments and included mitigation additives of medium chain fatty acids (MCFA), organic acids (OA), essential oils (OA), formaldehyde based products, and sodium bisulfate. From Exp. 1, formaldehyde, medium chain fatty acids (MCFA), essential oils (EO), and organic acid (OA) each decreased detectable PEDV RNA compared to the control (P<0.05). Additionally, PEDV stability over time was influenced by matrix as the meat and bone meal and spray-dried animal plasma resulted in a greater (P<0.05) quantity of detectable PEDV RNA over 42 days compared to that of the swine diet and blood meal. In Exp. 2, the 1% MCFA inclusion was equally effective at mitigating PEDV as a commercially available formaldehyde product in the complete swine diet. To further explore the effects of MCFA against PEDV, Exp. 3 was conducted to evaluate lower inclusion levels of MCFA and fat sources containing MCFA. It was noted that formaldehyde, 1% MCFA (1:1:1: of caproic, caprylic, and capric acids), 0.66% caproic, 0.66% caprylic, and 0.66% capric acids enhance the RNA degradation of PEDV in swine feed as determined by a bioassay. The MCFA were also evaluated against Salmonella Typhimurium, Generic Escherichia coli, Enterotoxigenic Escherichia coli, and Campylobacter coli. It was noted that the efficacy of the MCFA varied between each bacteria species with caproic and caprylic being the most effective. Commercial developmental products were also tested and determined that Product A and B provided the lowest MIC values across Salmonella Typhimurium, Generic Escherichia coli, and Enterotoxigenic Escherichia coli (P < 0.05). Product A and B were further tested in an animal disease trial utilizing a strain of enterotoxigenic Escherichia. coli O149:K91: K88. From d 7 to 14, chlortetracycline, 1:1:1 blend, and Product B, all improved G:F compared to the control (P<0.05). This also led to chlortetracycline and Product B having an improvement (P<0.05) over the control diet from d 0 to 14. A treatment × day interaction for the enterotoxigenic E. coli plate scores was observed (P < 0.05), which occurred because of the decrease (P<0.05) in plate scores for Product B from d 1 to d 14 and an increase (P<0.05) in chlortetracycline from d 7 to 14. A decrease (P<0.05) in plasma urea nitrogen and haptoglobin was observed as time increased from d -2 to 14. In summary MCFA have shown to be an effect interventional mitigation strategy against PEDV and various bacteria.
31
Huang, Yu-jen, e 黃有任. "Optimization of nutrient feed concentration and operation time for the production of poly(beta-hydroxybutyrate)". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/48019512176703567805.
Testo completoAbstract (sommario):
碩士國立臺灣科技大學
化學工程系
98
Plastic materials have become an integral part of contemporary life. The reason for such a wide usage is the property of resistance to degradation. However, this property of plastics makes them an environmental hazard. In such a scenario, biodegradable plastics have properties similar to conventional plastics, offer an attractive alternative to conventional plastics. Poly-beta-hydroxybutyrate (PHB) is 100% biodegradable plastic. They possess properties similar to various synthetic thermoplastics like polypropylene and hence can be used in their place. However, the price of PHB is still at a premium because of the cost of production. The optimization of feeding strategy is technique we used in order to reduce the production cost. Thus, an engineering approach to tackle this problem would be to develop a mathematical model that will facilitate not only the understanding of the system but also help in designing the nutrient-limited fed-batch cultivations to improve productivity. Last, we design a process control method in hope that it will nullify the effects of disturbance on the system to maintain the optimal operation.
32
林樹慶. "Removal of Organic Compounds in Water Using a NF Membrane：Effect of Feed Concentration and Co-existing Inorganic Ions". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/22754956601118373983.
Testo completoAbstract (sommario):
碩士大葉大學
環境工程學系碩士班
92
The research investigates the effect of feed concentration ferulic acid bis phenol A by on the removal of NF membrane. In addition, effect of co-existing inorganic ions (such as NaCl and Na2SO4) is also discussed. Rejection of ferulic acid、bis phenol A、NaCl and Na2SO4 are by NF-270 greater than 70%、99%、60%、95%, respectively. Results also show increasing the feed concentration of the organic compound usually leads to the decrease of rejection, which can be explaned by the increase of concentration driving force across the membrane. The relationship between rejection and permeate flux was developed based on the irreversible thermodynamics approach and was modified to extend the applicability to both the single and binary mixed systems.
33
Chen, Chao-Yi, e 陳朝宜. "The Effect of Anionic Feed on Serum Ionized Calcium Concentration and Uterine Involution during the Transition Period of Holstein Cows in Taiwan". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/07096103840710781806.
Testo completoAbstract (sommario):
碩士國立中興大學
動物科學系所
96
According to the research of advanced dairy countries, dairy cows fed with the low dietary cation-anion difference（DCAD expressed as（[Na] + [K]）−（[Cl] + [S]）milliequivalents/100 g of DM）or anionic salts during the last 3 to 4 wk prepartum would decrease the incidence of hypocalcemia and reduce the metabolic problems, so that the longevity of dairy cows will be improved. In Taiwan, although several commercial brands of anionic feeds have been marketed, no research on them has been reported. In trial 1, fifteen nonlactating, multiparous pregnant Holstein cows at 18 ± 7 d precalving were randomly assigned into three dietary treatments with DCAD of ＋3（HD）, －15（LDa）and －15（LDb）meq/100 g of DM , which adjusted with commercial, domestic and imported concentrates, respectively. Except for a couple of cows in LDa and LDb, most of the cows consumed all the concentrates fed during the early period of the experiment（d 1 through 5）. The means of the time spent on concentrate intake by the cows in LDa（16.5 min）and LDb （12.3 min）were significantly longer than that in HD（5.23 min）（P＜0.01）. During d 6 through d 21, concentrates fed to the cows were completely consumed in all treatments. The palatabilities expressed as the time spent on concentrate intake were not different among the three treatments（P = 0.48）. At day 21, blood Pco2, bicarbonate concentration and base-excess（BE）were less in cows in LDa than those in HD（P＜0.05）. Serum ionized Ca concentration（4.89 ± 0.10 mg/dL）was significantly greater in LDa than that in HD（4.64 ± 0.11 mg/dL）. Urine was acidified by LDa or LDb to the extent from pH 5.5 to 6.8. In trial 2, in the last 3 weeks of the dry period, eighty non-lactating, pregnant Holstein-Friesian cows were allotted randomly to two groups, the control or the anion-treated（A）concentrate treatments, by which the DCAD of +10.3 and −6.8 meq/100g DM of the diet were formed, respectively. Significant increase of serum ionized Ca concentrations（P＜0.05）and decrease of retained placenta incidence（P＜0.05） at calving were observed in cows fed with A diet in comparison with those in control. Uterine horn diameters, indicating extent of uterine involution, at 30 d postpartum in cows fed with A diet were narrower than those in control（P＜0.05）. In both trials, there were no significant differences among the dietary treatments in the levels of blood serum parameters including albumin, nonesterified fatty acids, phosphorus, magnesium, aspartate aminotransferase, alkaline phosphatase, triglycerides, total cholesterol, urea nitrogen and creatinine. In conclusion, preparturient cows fed with anionic feeds are able to increase serum ionized Ca concentration and improve uterine involution of postpartrient cows.
34
leu, shinn jong, e 呂信忠. "Effect of Cycling of Feed Substrate Concentration on the Fate of Plasmid-Bearing Microorganisms in Continuous Culture : The Case of Variable Plasmid Loss Probability". Thesis, 2000. http://ndltd.ncl.edu.tw/handle/74241466540554474891.
Testo completoAbstract (sommario):
碩士淡江大學
化學工程學系
88
The continuous stirred tank reactor (CSTR) with cycling in the feed substrate concentration has been analyzed by numerical simulations for the case where the plasmid loss probability is variable and a difference in times for the plasmid-bearing and plasmid-free microorganisms to adapt to changing environment exists. Operating diagrams on the D (dilution rate) — P (period) plane are constructed to show the operating conditions under which these two microorganisms will ultimately coexist. It is found that both microorganisms can coexist ultimately if there is sufficient difference in the adaptation times, and the larger the difference is, the larger the coexistance region will be ; larger coexistance regions are also obtained for larger maximum feed substrate concentrations. Washout of the plasmid-bearing microorganisms occurs for the case where the on-off time ratio is either too larger or too small, and there exists an optimal ratio which yields the largest coexistance regions. The effect of the ratio of maximum specific growth rates on the coexistence region, and the effects of the operating parameters period, dilution rate, maximum feed substrate concentration and on-off time ratio on the ultimate mass fraction of the plasmid-bearing microorganisms are also discussed.
35
Yonika, Dhika, e 狄卡. "The effect of dioxin contaminated feed on production performance, egg, liver, abdominal fat dioxin concentration, and gene expression in liver of red-feathered Taiwan country chicken". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/83631166755842824176.
Testo completoAbstract (sommario):
碩士國立屏東科技大學
動物科學與畜產系所
102
The aim of this research was to evaluate dioxin contaminated feed on production performance, egg, liver, abdominal fat dioxin concentration, and gene expression in the liver of red-feathered Taiwan country chickens. A total number of 32 laying hens were divided into 2 treatments control and dioxin group. Sixteen chickens were fed with the contamination dioxin feed for fourteen days, were continued by clean feed up to 42 days. Chickens were sacrificed at 2, 14, 28, and 42 after dioxin treatment. The dose of 17 dioxin congeners were added to the diet is 5.5 ng TEQ kg-1 feed. Experimental data was analyzed with 2 x 4 Factorial Design. Differences between the treatments were analyzed and compared by least squares mean and a P-value of < 0.05 was considered significantly. The result indicated that dioxin was significantly reduced average daily gain (ADG) 5.76 g （P ＜ 0.05）. Dioxin administrated was no significantly different (P > 0.05) in liver weight, liver percentage, spleen weight, spleen percentage, egg weight and egg production. However, dioxin treatment tended to decrease relative spleen weight (P = 0.08). PCDD/PCDFs concentrations in liver were higher than control group. Then, concentration PCDD/PCDFs in liver gradually decreased after dioxin contaminated feed was changed by clean feed. Liver is the highest concentration of dioxin in tissue, continued by egg, and abdominal fat. Dioxin altered lipid metabolism gene expression in liver. Moreover, dioxin altered gene expression in the liver which related with PPAR signaling pathway, pyruvate metabolism pathway and glycolysis/gluconeogenesis pathways. Genes that has role in PPAR signaling pathway are apolipoprotein A-V (APOA5), carnitine palmitoyltransferase 1A (liver) (CPT1A), cytochrome P450 family 7 subfamily A, polypeptide 1 (CYP7A1), matrix metallopeptidase 1 (interstitial collagenase) (MMP1), and phosphoenolpyruvate carboxykinase 1 (PCK1). Genes that has role in pyruvate metabolism and glycolysis/gluconeogenesis pathways are acyl-CoA syntheses short-chain family member 1 (ACSS1), phosphoenolpyruvate carboxykinase 1 (PCK1), pyruvate dehydrogenase (lipoamide) alpha 1 (PDHA1), and similar to acetyl-CoA synthetase 2-like (LOC423347).
36
Bui, Viet A. "A study of osmotic distillation in hollow fibre modul". Thesis, 2002. http://handle.uws.edu.au:8081/1959.7/4.
Testo completoAbstract (sommario):
Osmotic distillation is a process of removing water from an aqueous solution, driven by water vapour pressure gradient across a hydrophobic membrane. The process occurs at or below ambient temperature and under atmospheric pressure. This research project investigates the osmotic distillation process in hollow fibre modules using hollow fibres PP375, PV375 and PV660 supplied by Memcor Australia. Operating conditions such as temperature, feed concentration and brine cross flow velocity, but not the feed cross flow velocity, were found to have significant effect on the flux. Models for heat and mass transfers were used to study the polarisation phenomena in osmotic distillation. Temperature and concentration profiles at the membrane surfaces due to polarisation were quantified. Scholfield and Ordinary Diffusion models for flux prediction based on the bulk conditions were developed and validated. Models for water activity and viscosity of aqueous glucose and calcium chloride solutions were also developed and validated in this work.
37
Sun, Yun-Bing, e 孫雲屏. "Geographic Diversification, Industry Concentration, and Audit Fees: An Analysis of Audit Fee Deregulation". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/84975555029373130767.
Testo completoAbstract (sommario):
碩士長榮大學
經營管理研究所
99
For a long period, Accountants had to obey the Remuneration Standards. In 1998, the Fair Trade Commission, Executive Yuan, R.O.C. declared that the Remuneration Standards registered by the CPA had violated the Fair Trade Laws, resulting in fierce pricing competition and other method to increase audit fees by the Accountant offices (e.g. Geographic Diversification) . Thus this research focuses on the impact of Geographic Diversification and Industry Concentration level on audit fees and while the audit fees is without minimum. The subject offices are divided into whether undertaking company financial business or not and the size of the office whether it is large or small. Data are gathered and proofed by the Financial Supervisory Commission, Executive Yuan, R.O.C. Accountant Office Serving Report, 1995-2002. The result of the research indicates that Geographic Diversification and Industry Concentration level has a direct ratio with audit fees. Large Accountant offices have no clear relationship with Industry Concentration, but small Accountant offices have inverse ratio. Moreover, large Accountant offices’ Geographic Diversification have direct ratio with audit fees, Industry Concentration will decrease audit fees; small Accountant offices and all offices’ Geographic Diversification have direct ratio with audit fees, nothing indicates that the cancelation of audit fees minimum takes significant effect on it, but the cancelation did take effect on the relationship of Industry Concentration and audit fees.
38
LIN, SHENG-HUNG, e 林聖紘. "The Association between Audit Market Concentration and Audit Fee". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/04329900013152519627.
Testo completoAbstract (sommario):
碩士銘傳大學
會計學系碩士班
104
This study aims to investigate the current situation of audit market concentration and examine the association between audit market concentration and audit fee in Taiwan. Using a sample of 4437 observations listed in Taiwan stock market between 2009 and 2014, the empirical results show that Taiwan’s audit market concentration is high and remains stable during the research period. Furthermore, considering the industry size, the empirical evidence shows that audit market concentration has a positive association with audit fee, which partly verifies the concern of the regulatory bodies, that is, high market concentration might induce potential negative effect on audit fee increases. The last findings show that the industry size could moderate the positive association between market concentration and audit fees, implies that the audit market still remains some degree of competition in the large industries and thus constrains the increase in audit fees.
39
Hsin, Kun-Yi, e 辛坤鎰. "Effect of Available Phosphorus Concentrations and Bioavailability Bvaluations of Feed Grade Phosphates for Broilers". Thesis, 2000. http://ndltd.ncl.edu.tw/handle/84273869689303237562.
Testo completoAbstract (sommario):
碩士國立中興大學
畜產學系
88
Effect of available phosphorus concentrations and bioavailability evaluations of feed grade phosphates for broilers The object of this study was to evaluate the effect of various available phosphorus and the feed grade phosphates to broilers on growth performance, skeleton, blood characteristic, and the bioavailability. As well as to determine the phosphorus solubility in various solvents and relationship between the bioavailability. The experiments was supposed to be able to predict the availability of the phosphates in rasier chemical methods. The 1-day-old broilers were examined arrangement with a 4×4 factorial arrangement. The treatments were A: purified grade monobasic calcium phosphate (P:21%), and three feed grade phosphates as B (P:21%), C (P:18%) and D (P:21%), and contained available phosphorus (AP) of 0.25, 0.30, 0.35 and 0.40%, respectively. Treatments had 6 replicates. Each replicate had 6 chicks. Chicks were allowed to consume feed and water ad libitum for 28-d test periods. Weight gain and feed intake were determined on a weekly basis. The calcium , crude protein concentrations and metabolic energy of each test diet were 1%, 22.14% and 3031 kcal/kg, respectively. The phosphorus was according to the test design. The result showed in the aspect of growth performance, feed intake and weight gain increased with supplement AP. A group was significantly higher than others groups (P<0.05). Feed intake and weight gain of groups B and C which had similar phosphorus contents were better than D group (P<0.05). There no effect on feed:gain. Skeleton characteristic, mechanical properties, ash, Ca and P content was significantly increased as supplement the AP. Length and weight of tibia, ash, Ca and P content in C group were lower than the other groups (P<0.05). Results about blood characteristic showed that inorganic P of plasma was significantly increased as supplement the AP and reversed on plasma Ca. The activity of alkaline phosphatase was no effect. While utilized slop ratio method and took A group as the standard phosphate (set phosphorus availability as 100%), and adopted weight gain, tibia ash percentage as response criteria, the bioavailability of feed grade phosphates were D>B>C. Weight gain, ash and feed efficiency (G/F) were integrated to be a response criteria (triple response method), and thus calculation the relative biological values. The value showed that the result obtained from various method taking weight gain and ash percentage as response criteria that D group was the highest (96.51%), fallow with the B group (94.7%). The higher solubility of phosphates in various solvents appeared when A and D groups which had higher bioavailability in 2.0% citric acid. However, there not similar with 0.4% HCl, and C group which had the lowest bioavailability from the lowest solubility. The results expect phosphates that had lower solubility (<90%) and bioavailability as well. It would seem inappropriate and risky to replace bioassays totally with these test. Key Words: broiler, phosphate, available phosphorus, bioavailability.
40
Naicker, Neressa. "Particle segregation associated with sub-sampling of feed at a typical UG2 concentrator". Thesis, 2017. https://hdl.handle.net/10539/24858.
Testo completoAbstract (sommario):
A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Metallurgical Engineering, Johannesburg, August 2017A particular Upper Group 2 (UG2) reef ore treating Concentrator Plant has been historically under-accounting in terms of 4T (Platinum, Palladium, Rhodium and Gold) content. It has been postulated that the main reason for the consistent under-accounting is due to the correct sub-sampling of finer particles and consequently under sub-sampling of the coarser particles present in the feed slurry streams into the plant. The test work presented involved a series of experimental studies designed to gain an understanding of the presence and extent of particle segregation in the intermediate hopper of a typical UG2 feed vezin sampling system. A total of three stages of test work were conducted, including vezin credibility and chronological sub-sample tests, tests on a re designed nozzle and mechanical hopper. The tests on sub-sampling of the feed material from the intermediate hopper performed on the current sampling arrangement (Stage 1, Test 1) demonstrated that segregation occurs in the intermediate hopper of the feed sampling system. A consistent bias was observed between the reject and official samples with the official samples having more fine particles and being higher in 4T grade than the reject samples. By means of a paired t-test, the calculated bias for % mass retained was deemed significant at the 95% confidence level. This outcome together with the size by assay analysis performed indicated that an under accounting scenario would result. Stage 2 test work involved the use of an alternative nozzle design at the outlet of the current intermediate hopper as a way of optimizing the current arrangement. The sub-sampling tests performed after this modification resulted in a more random distribution of fine and coarse particles in both the reject and official samples. The PSD’s for the reject and official samples were similar across all test runs however the 4T grade was not consistent. The calculated bias for % mass retained was not significant at the 95% confidence level. Stage 3 test work involved the application of a new hopper design which was equipped with an agitator in an attempt to reverse the segregation observed in the old hopper design. The ii new hopper also necessitated the introduction of an alternative sampling protocol where multiple primary increments were collected and the sub-sampling to produce an official and reject sample while agitation transpires created the platform for better suspension of all particles. The particle segregation in the intermediate hopper was reduced and the calculated bias for % mass retained was not significant at most measurements at the 90% and 95% confidence level. The change in nozzle and hopper design seemed to not have an impact on the overall 4T grade of the official sub-samples generated over the sampling campaign. There was a slight improvement in the % COV for the % +38μm from Stage 1 to Stage 2. With the inclusion of the new nozzle design to the mechanical hopper, the % COV for the % +75μm improved from 26.7% to 14.5%. In general, it is believed that the particle segregation which was so evident in the baseline test was significantly reduced with the incorporation of the alternative nozzle design and mechanical agitation. Compressed air agitation alone does not seem to keep all particles of varying size and density in suspension in the intermediate hopper. A future mechanical hopper prototype should be redesigned and fabricated from a cheaper yet robust material and should also be ergonomically improved. The incorporation of internal baffles inside the mechanical hopper should also be considered to reduce the impact of vortexing. An inspection port should also be integrated into the design to be able to view the agitator in operation and observe for vortexing of the slurry material or retention of residual solids in the hopper after sub-sampling takes place. Multiple air agitation points may also be considered in future designs of the mechanical hopper (for instance, an air agitation point above and below the pneumatic valve). It is recommended that any future investigation or test work around particle segregation in the intermediate hopper be conducted in a controlled testing environment. In this way, any random variation due to the process can be disregarded and the true bias (if any) can be determined and confirmed.
XL2018
41
Hausmann, Angela. "Membrane distillation in dairy processing". Thesis, 2013. https://vuir.vu.edu.au/25680/.
Testo completoAbstract (sommario):
Membrane distillation (MD) is a novel membrane process for industry which promises to be a low energy and/or low cost alternative to established separation technologies. The overall objective of this research was the theoretical and experimental investigation of direct contact MD (DCMD) for major dairy processes. Milk and whey were the two major dairy streams explored in this study.
42
Yang, Wan-Lin, e 楊婉伶. "Brain and tissues docosahexaenoic acid concentration in neonatal rats breast-fed and tube-fed with different levels of docosahexaenoic acid". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/99394387275699613545.
Testo completoAbstract (sommario):
碩士輔仁大學
營養科學系
96
Docosahexaenoic acid (DHA) is a long-chain polyunsaturated fatty acid, essential for the growth and development of brain in infants. Main dietary source of DHA is fish oil. The purpose of this study is to compare plasma and brain tissues’ DHA levels between pups by breast-fed and tube-fed. The first part of this study was to feed pregnant rats with different levels of DHA in the diets, including control (without DHA added), DHA-adequate ( 0.01 g DHA/kg B.W. added) and DHA-high group ( 0.1 g DHA/kg B.W. added) diets. Rat’s milk was collected at the 14th day of lactation, followed by determination of DHA concentration. Pups were sacrificed at the 21th day of lactation. Results showed that DHA-high group had higher DHA content in milk (254 ± 2.5 mg DHA/ 100 ml rat milk) than rat in the control group (82 ± 0.1 mg DHA/ 100 ml rat milk, p＜0.05). However, compared with the control group, higher DHA concentration was discovered in plasma, liver, cerebellum and medulla oblongata of pups in the DHA-high group. Higher recovery rate of dietary DHA to organs or tissues were found in rat control group than that in other two groups. The second part of this study was to feed neonatal pups with different levels of DHA in the artificial rat milk by gastrostomy. DHA contents in the formula (control, adequate and high group) were designed to be 0, 5 and 300 mg DHA/ 100 ml milk, respectively. After 14 days of feeding, pups were sacrificed. Significantly higher DHA concentration was found in plasma, liver and brain tissues of the pups in the DHA-high group than pups in control group. The recovery rate of pups by gastrostomy, and there dietary DHA to plasma, liver or brain tissues in DHA-adequate pups were higher than that in pups of DHA-high group. Except liver and thalamus and hypothalamus, DHA contents in the rest of the tissues of breast-fed group were higher than that of tube-fed group. Compared of DHA concentration between DHA adequate (92.70 ± 54.35μg/ml) and control (64.57 ± 36.81μg/ml) group by tube-fed, the results suggested that the amount of DHA added in the commercial infant formula, i.e. up to 5 mg DHA/ 100 ml milk, might not be high enough to influence level of body DHA in the neonatal pups. The DHA added in the tube-fed formula over 300 mg DHA/100 ml might have the similar effect on elevation of DHA levels in plasma, liver and brain tissues as breast milk (254 mg DHA/100 ml rat milk).
43
CHEN, HSIAO-YUN, e 陳筱芸. "The Impact of Audit Market Concentration on the Relationship between Corporate Social Responsibility and Audit Fees". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/2y4bsw.
Testo completoAbstract (sommario):
碩士國立臺北大學
會計學系
107
In recent years, corporate social responsibility (CSR) has gradually received attention. Previous study has confirmed that companies investing in CSR are positively correlated with audit fees. In addition, the rise in the concentration of the audit market has also raised concerns, and everyone pays more attention on its relevance to audit quality. This study conjecture that the quality of the audit will affect the audit efforts of auditors in the face of clients with highly information transparency such as companies engaged in corporate social responsibility activities, and further affecting the audit fees. Therefore, the main purpose of this study is to explore the moderate effect of audit market concentration on the relationship between CSR and audit fees. At the same time, in response to the suggestion of Francis et al. (2013) that we should pay attention to the distribution of the concentration of audit market among Big 4. This study divides the market concentration into one or two audit firms leading the overall market and relatively average market share among the Big 4. The sample period of this study is from 2011 to 2017. The preliminary analysis supports the research hypothesis. However, after controlling other variables affecting the audit fees, the moderate effect becomes less obvious. In summary, there is a lower degree of evidence to support that audit market concentration will moderate the relationship between CSR and audit fees.
44
Lee, Mi-Hsueh, e 李米雪. "An analysis of the relationship between client-industry concentrations for accounting firms and audit fees". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/10495397819294766335.
Testo completoAbstract (sommario):
碩士淡江大學
會計學系碩士在職專班
101
Due to the increasingly fierce competition in audit market, service differentiation becomes one of the most important strategies to retain existing clients and enhance competitiveness for CPA firms. The analysis is focused on the association between client-industry concentrations for different sizes of CPA firms and fees (including audit fees and non-audit tax fees) from the supply-side perspective of the audit market. Empirical data obtained from 2002 to 2011 Survey Report of Audit Firms in Taiwan, published by the Financial Supervisory Commission, Executive Yuan generate 7,028 CPA firms as samples per year. The main findings are as follows: a significant positive correlation between client-industry concentrations and audit fees exists among CPA firms, especially among sole-proprietor CPA firms. According to the findings, a significant negative correlation between client-industry concentrations and audit fees exists among middle to large CPA firms, and the reason for the low audit fee is assumed to be the effect of scale economies; however, the correlation between client-industry concentrations and non-audit tax fees is positive which means CPA firms get higher non-audit tax fees through client-industry concentrations. Finally, this paper conducts several sensitivity analyses which show the stability of aforementioned empirical results. These research results can not only be used as a reference aid to practical management in audit pricing, but also be used to fill the insufficiency of literature studying in this area.
45
Panditharatne, Mary Charushi. "Fed-batch fermentation of Clostridium thermocellum ATCC 27405 with high cellulose concentrations for the production of biofuels". 2015. http://hdl.handle.net/1993/30573.
Testo completoAbstract (sommario):
Consolidated bioprocessing is a one-step process that allows the direct microbial conversion of cellulosic substrates to ethanol and hydrogen. The fermentation was initially performed in batch cultures, in a pH and temperature controlled reactor using Clostridium thermocellum ATCC 27405. With an objective of increasing the production of ethanol and hydrogen, various types of fed-batch fermentations were investigated: variable volume (VV) fed-batch, fixed volume (FV) fed-batch, and semi-continuous fermentation. Semi-continuous processes were carried out at low (10-15 g/L) and high (20-25 g/L) cellulose concentrations. The maximum ethanol production obtained in batch, VV, FV, semi-continuous with low concentrations and high concentrations were 554 mmol, 336 mmol, 477 mmol, 695 mmol and 741 mmol respectively. In the same order, the total hydrogen production was 288 mmol, 364 mmol, 231 mmol, 434 mmol, and 387 mmol. Overall, the semi-continuous fermentation showed more promise in terms of large-scale deployment compared to batch, VV, and FV fed-batch.October 2015
46
Longpré, Jessie. "La texture et la granulométrie de la moulée influencent les concentrations d’acide propionique et butyrique de même que la prévalence d’Escherichia coli dans le tractus gastro-intestinal du porc d’engraissement". Thèse, 2015. http://hdl.handle.net/1866/13376.
Testo completoAbstract (sommario):
Certaines stratégies alimentaires sont actuellement considérées pour remplacer l’usage des antimicrobiens dans les fermes porcines. Les objectifs de cette étude étaient d'évaluer l'effet de la granulométrie et de la texture des aliments sur les concentrations d'acides gras volatils intestinaux, la composition des populations pathogènes et commensales d’E. coli et sur les performances de croissance des porcs. Des porcs d'engraissement (n= 840) ont reçu l'une des six diètes suivantes: moulée texturée 500, 750 et 1250 µm et moulée cubée 500, 750 et 1250 µm. Le gain de poids a été mesuré à chaque changement de formulation de moulée. À l'abattoir, les contenus du caecum et du côlon de 165 porcs ont été échantillonnés pour le dénombrement des E. coli par PCR quantitatif (qPCR) et pour la quantification des AGV. Le gène yccT a été utilisé pour dénombrer les E. coli totaux. Une diminution du taux de conversion alimentaire a été associée avec la moulée cubée et/ou la moulée de 500 µm. Les concentrations d’acide propionique et butyrique, et ce tant au niveau du caecum que du côlon, étaient plus élevées chez les porcs recevant de la moulée texturée que chez ceux recevant de la moulée cubée. Du point de vue de la granulométrie, les concentrations caecales et du côlon d’acide butyrique étaient plus élevées chez les porcs alimentés avec de la moulée de 1250 µm que chez ceux recevant de la moulée de 500 µm. D'autre part, les niveaux intestinaux d’E. coli totaux étaient plus élevés pour les porcs nourris avec de la moulée cubée que pour ceux ayant reçu de la moulée texturée. Les résultats ont montré que la moulée texturée est associée à des performances de croissance plus faibles mais à des changements intestinaux favorables.Natural approaches, such as dietary modifications, are now being considered to replace antimicrobials for the control of bacterial infections in pigs. The objectives of this study were to assess the effect of feed size and texture on intestinal Volatile fatty acids profiles and concentrations, E. coli populations, and on growth performance. Fattening pigs (n=840) received one of six different diets: mash feed 500, 750 and 1250 µm and pellet feed 500, 750 and 1250 µm. Weight gain of pigs was monitored for each diet formulation over the fattening period. At the slaughterhouse, caecal and colon contents from 165 pigs were sampled for enumeration of E. coli by quantitative PCR (qPCR) and for acetic, propionic and butyric acid quantification. The yccT gene was used to enumerate total E. coli. A decrease in feed conversion associated with pellet texture and/or 500 µm particle size was observed for each diet formulation. In addition, caecal and colon propionic acid concentrations and caecal and colon butyric acid concentrations were lower for pigs receiving pellet rather than mash feed. Moreover, caecal (p=0,0208) and colon (p=0,0006) butyric acid concentrations were higher for pigs receiving a feed with a 1250 µm rather than 500 µm particle size. For total E. coli enumeration, caecal (p=0,01) and colon (p=0,04) yccT gene copies were higher for pigs receiving pellet rather than for those receiving mash feed. Taken together, results showed that mash feed is associated with favourable intestinal changes (VFA levels) and with a reduction of E. coli in the pig.
47
Caldwell, Lisa. "The Influence of Breed and Temperament on Circulating Concentrations of Insulin-like Growth Factor-I (IGF-I) and Its Relationship to Feed Efficiency in Beef Cattle". 2009. http://hdl.handle.net/1969.1/ETD-TAMU-2009-05-734.
Testo completoAbstract (sommario):
Insulin-like growth factor-I (IGF-I) is a growth hormone that acts as a key modulator of the growth axis. Serum and plasma concentrations of IGF-I have been linked to economically important traits in beef cattle.
In order to determine whether concentrations of IGF-I differed among breeds of beef cattle, plasma samples from purebred and crossbred animals were analyzed. Two calf crops were derived from three-breed diallel matings using temperate and tropically-adapted breeds of cattle. The breeds consisted of temperate Bos taurus (A; Angus), tropical Bos indicus (B; Brahman), and tropical Bos taurus (R; Romosinuano). Plasma samples were obtained from 10 heifers and 10 steers of each breed-type at weaning, and two dates post-weaning. Concentrations of IGF-I were determined by radioimmunoassay (RIA). Breed differences were observed (P < 0.001). Relative to the temperate Bos taurus breed, IGF-I was greater in tropically-adapted breed-types.
In an effort to select for the improvement of economically important traits, experiments were performed to explore the possible use of concentration of IGF-I and temperament assessment as tools for selection. Using a Calan gate system, 3 Brahman heifer crops were fed during70-day trials. Performance and feed intake data were collected to determine feed efficiency. Temperament, determined by exit velocity and pen score, was evaluated at weaning. Serum samples were taken at weaning and days 0 and 70 of each trial. Concentrations of IGF-I and cortisol were determined by RIA. Correlations including IGF-I were weak (P > 0.05). Temperament had no significant effect on RFI but may affect ADG.
In an attempt to examine the relationship between IGF-I and RFI, body weight and feed intake data were collected during individual finishing phase feeding trials, on steers at El Reno, OK. The breeds consisted of temperate Bos taurus (A; Angus), tropical Bos indicus (B; Brahman), and tropical Bos taurus (R; Romosinuano). Plasma samples were obtained from 10 steers of each breed-type at weaning and days 0 and 60 of each finishing phase. Concentrations of IGF-I were determined by RIA. Correlations between IGF-I and RFI were weak (P > 0.05). Breed and year significantly influenced RFI (P < 0.01).
48
Van, Rooy Willem. "Solar thermal augmentation of the regenerative feed-heaters in a supercritical Rankine cycle with a coalfired boiler / W.L. van Rooy". Thesis, 2015. http://hdl.handle.net/10394/15901.
Testo completoAbstract (sommario):
Conventional concentrating solar power (CSP) plants typically have a very high levelised cost of
electricity (LCOE) compared with coal-fired power stations. To generate 1 kWh of electrical
energy from a conventional linear Fresnel CSP plant without a storage application, costs the
utility approximately R3,08 (Salvatore, 2014), whereas it costs R0,711 to generate the same
amount of energy by means of a highly efficient supercritical coal-fired power station, taking
carbon tax into consideration.
This high LCOE associated with linear Fresnel CSP technology is primarily due to the massive
capital investment required per kW installed to construct such a plant along with the relatively
low-capacity factors, because of the uncontrollable solar irradiation. It is expected that the
LCOE of a hybrid plant in which a concentrating solar thermal (CST) station is integrated with a
large-scale supercritical coal-fired power station, will be higher than that of a conventional
supercritical coal-fired power station, but much less than that of a conventional CSP plant. The
main aim of this study is to calculate and then compare the LCOE of a conventional supercritical
coal-fired power station with that of such a station integrated with a linear Fresnel CST field.
When the thermal energy generated in the receiver of a CST plant is converted into electrical
energy by using the highly efficient regenerative Rankine cycle of a large-scale coal-fired power
station, the total capital cost of the solar side of the integrated system will be reduced
significantly, compared with the two stations operating independently of one another for
common steam turbines, electrical generators and transformers, and transmission lines will be
utilised for the integrated plants.
The results obtained from the thermodynamic models indicate that if an additional heat
exchanger integration option for a 90 MW (peak thermal) fuel-saver solar-augmentation
scenario, where an annual average direct normal irradiation limit of 2 141 kWh/m2 is considered,
one can expect to produce approximately 4,6 GWh more electricity to the national grid annually
than with a normal coal-fired station. This increase in net electricity output is mainly due to the
compounded lowered auxiliary power consumption during high solar-irradiation conditions. It is
also found that the total annual thermal energy input required from burning pulverised coal is
reduced by 110,5 GWh, when approximately 176,5 GWh of solar energy is injected into the
coal-fired power station’s regenerative Rankine cycle for the duration of a year. Of the total
thermal energy supplied by the solar field, approximately 54,6 GWh is eventually converted into
electrical energy. Approximately 22 kT less coal will be required, which will result in 38,7 kT
less CO2 emissions and about 7,6 kT less ash production. This electricity generated from the thermal energy supplied by the solar field will produce
approximately R8,188m in additional revenue annually from the trade of renewable energy
certificates, while the reduced coal consumption will result in an annual fuel saving of about
R6,189m. By emitting less CO2 into the atmosphere, the annual carbon tax bill will be reduced
by R1,856m, and by supplying additional energy to the national grid, an additional income of
approximately R3,037m will be due to the power station. The annual operating and
maintenance cost increase resulting from the additional 171 000 m2 solar field, will be in the
region of R9,71m.
The cost of generating 1 kWh with the solar-augmented coal-fired power plant will only be
0,34 cents more expensive at R0,714/kWh than it would be to generate the same energy with a
normal supercritical coal-fired power station.
If one considers that a typical conventional linear Fresnel CSP plant (without storage) has an
LCOE of R3,08, the conclusion can be drawn that it is much more attractive to generate
electricity from thermal power supplied by a solar field, by utilising the highly efficient large-scale
components of a supercritical coal-fired power station, rather than to generate electricity from a
conventional linear Fresnel CSP plant.MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015
49
Munoz, Mayte Mireya Aleman. "Effect of a direct-fed microbial on plasma concentrations of hormones and metabolites in primiparous and multiparous Holstein cows". 2005. http://digital.library.okstate.edu/etd/umi-okstate-1338.pdf.
Testo completo
50
Vozková, Karolína. "Bankovní poplatky - jejich determinanty a vliv na ziskovost a rizikovost bank". Doctoral thesis, 2020. http://www.nusl.cz/ntk/nusl-435799.
Testo completoAbstract (sommario):
This thesis consists of five essays dealing with the fee and commission income in European banks from the macro, sector and bank level perspectives. This topic is of high relevance since fee income represents the largest part of the non-interest income of EU banks. The first part of the thesis deals with banks in general terms, while the second part is focused solely on cooperative banks, which represent approximately 20% of the EU banking sector. We compare the magnitude of the bank fee income across EU countries and study its determinants and impacts on banks' performance. The first essay compares the magnitude of the fee income across EU countries with a special emphasis on the Czech Republic from a macroeconomic perspective. First, we conclude that Czech banks are not abnormally dependent on fee income and their outstanding performance can be attributed to sound risk management, high liquidity and sufficient capital buffers rather than to excessive fees. Second, our evidence suggests that the share of fee income had an increasing trend in EU countries in recent years, which might be connected to the effort to maintain sufficient profitability in the low interest rates environment. We also discuss how new entrants, the so called low-cost banks, changed the banking sector in the Czech Republic....