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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.
71

Net present value analysis of plant investment to add capacity

Gullickson, Travis R. January 1900 (has links)
Master of Agribusiness / Department of Agricultural Economics / Allen M. Featherstone / Providing a recommendation on whether to make a capacity expanding capital investment in an existing butter plant is the subject of this thesis. This is important as the success of this project will have a significant impact on the future profitability of Land O'Lakes and provide a significant home for its member's milk production. The dairy industry has undergone change over the past decades. Milk production has moved from the traditional production area of the Upper Midwest to drier, more arid areas such as California. This has led to milk price premiums in the Upper Midwest and since milk is the major input to butter manufacturing, it has become more attractive to produce butter in other areas such as California. Much of the data collected in review of the industry were obtained from the USDA. This data were used to describe the industry and focus on the number of butter plants over time, the milk productivity per cow, and the total milk production by state. It provides a clear picture of fewer bigger plants, more productive cows, and a dramatic shift in milk production to the West, primarily California. A Net Present Value (NPV) model is developed to analyze the trade off between the initial capital investment and less costly milk procurement over time. The model also considers maintenance costs, salvage values, plant startup delays, and a one time salvage value gain by shutting down an Upper Midwest plant. After the initial model is developed, sensitivity analysis is conducted, focusing on key variables such as demand growth, and the spread between California and Upper Midwest milk prices. The conclusion is that additional investment in California butter production would be profitable, earning a positive NPV and an Internal Rate of Return (IRR) greater than the Land O'Lakes cost of capital. The solution is robust as they remain the same even after modeling lower demand and smaller milk price differentials. Therefore, I recommend that Land O'Lakes move ahead with this capital investment.
72

Modeling heat transfer in butter products : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy (Ph. D.) in Bioprocess Engineering, Institute of Technology and Engineering, Massey University, Palmerston North, New Zealand

Nahid, Amsha January 2007 (has links)
Butter keeping quality and pallet physical stability during transport and storage are dependent on the temperature distribution through the product. Understanding these temperature changes are of vital importance for the dairy industry with regard to butter manufacture, storage and shipping. Three dimensional mathematical models of heat transfer were developed to predict thawing and freezing in butter products. These models require accurate thermophysical data as an input. Specific heat capacity and enthalpy of butter with different composition was measured using Differential Scanning Calorimetry. The specific heat capacity of butter differs for cooling and heating operations due to significant supercooling and delayed crystallization of the fat fraction of butter at temperatures well below the equilibrium phase change temperature during cooling. This reduces the heat capacity for cooling relative to that for heating. Thawing of individual blocks of butter was accurately predicted by the conduction only model (no mass transfer limitations) with equilibrium thermal properties giving accurate predictions when the butter was completely frozen before thawing. For partially frozen butter the conduction model with the measured temperature dependent specific heat capacity data for unfrozen butter including melting of some of the fat fraction gave accurate predictions. For freezing it was observed that water in the butter supercools many degrees below its initial freezing point before freezing due to its water in oil structure. Experiments suggested that during freezing release of latent heat observed as a temperature rebound is controlled as much by the rate of crystallisation of water in each of the water droplets as by the rate of heat transfer. A conduction only model including water crystallization kinetics based on the Avrami Model predicted freezing in butter successfully. Simple models with equilibrium thermal properties and nucleation only kinetics (based on homogenous nucleation theory) or the sensible heat only model (no release of latent heat) gave poor predictions. The models for individual blocks were extended to predict heat transfer in butter pallets. A butter pallet contains product, packaging material and the air entrapped between the packaging and butter cartons. Measurements were made for freezing and thawing of full and half pallets at a commercial storage facility and in the University laboratory. Thawing and freezing in wrapped tightly stacked pallets was predicted accurately by the conduction only model with effective thermal properties (incorporating butter, packaging and air) estimated by the parallel model. For unwrapped tightly stacked or loosely stacked pallets there is potential for air flow between the adjacent cartons of butter. An alternative approach was developed which consisted of modeling the pallet on block by block basis using effective heat transfer coefficients for each surface. Different heat transfer coefficients were used on different faces of the blocks depending on the location of the block in the pallet. This approach gave good predictions for both unwrapped tightly stacked and loosely stacked pallets using the estimated effective heat transfer coefficients from the measured data. Further experimental and/or modelling work is required in order to develop guidelines for estimating effective heat transfer coefficient values for internal block face for industrial scenarios.
73

Shear and Composition Effects on Porous Network Properties and the Permeability of Lipid Films

Howard, Brandon Daniel January 2020 (has links)
No description available.
74

Isothermal Inactivation Studies of Listeria monocytogenes, Salmonella, and Enterococcus faecium NRRL B-2354 in Almond, Peanut, and Sunflower Butters

Liao, Ruo Fen 09 June 2022 (has links)
Vegetative, non-sporeforming foodborne pathogens show notable survival and uncanny thermotolerance in low water activity (aw) foods. Controlled studies on Listeria monocytogenes, Salmonella spp., and Enterococcus faecium NRRL B-2354 (a Salmonella surrogate) in a variety of food matrices support thermal process validation studies required to achieve global food safety objectives. In this study, we determined and compared thermal inactivation rates using independent six-strain cocktails of pathogens in three plant-based butters. Direct determinations of decimal reduction times (D-values) for L. monocytogenes, Salmonella, and E. faecium, in corresponding butters were inoculated using peanut oil, almond oil, or sunflower oil. Thermal Death Time (TDT) studies for the organisms were conducted in triplicate. Uniform bagged plant- based butter samples of Salmonella spp. or L. monocytogenes, or E. faecium alone were sandwiched in copper plates immobilized with recessed magnets. Samples underwent rapid heat treatments via water immersion under isothermal conditions ranging from 70°C to 85°C. Bacterial destruction in peanut butter (46% fat, 0.20 aw @ 25°C), almond butter, (50% fat, 0.32 aw @ 25°C), or sunflower butter (56% fat, 0.15 aw @ 25°C) was determined by direct plating. The TDT studies showed Salmonella spp. had consistently higher D-values than L. monocytogenes in all treatments, but pair-wise comparisons found no statistical difference when assessing the thermotolerance of the two pathogens in the individual plant-based butters tested (p > 0.005). These data support Salmonella as the primary pathogen of concern in low water activity foods and show the heat resistance of L. monocytogenes can approximate destruction kinetics observed for Salmonella spp. in low aw matrices. E. faecium exhibited the highest thermotolerance. This further supports the utility of this surrogate for Salmonella spp. and L. monocytogenes in high fat, low-moisture foods similar to the plant-based butters tested. Thermotolerance differences between a dry talc vs. peanut oil-based inoculation procedures in peanut butter were also evaluated. Surprisingly, the oil-based inoculations resulted in lower D- values (p > 0.01) for Salmonella spp. and the surrogate when compared to the dry inoculum.
75

Factors that militate against men's participation in functional literacy programmes : case study conducted in Mazowe District of Zimbabwe

Midzi, Davidson David 11 1900 (has links)
This study sought to determine factors that militate against men’s participation in the current Zimbabwean functional literacy programme. The research utilized the case study design and the data collecting instruments included in-depth interviews, focus group discussions, and observations. Twelve adults, seven males and five females aged between thirty-nine and sixty-five years of age were interviewed by the researcher on “Why men were not participating in the functional literacy programme”. No similar research had ever been conducted in Zimbabwe since the inception of the programme in 1992. The definitive findings of the study include a grounded research theory which was extrapolated from the data. After a thorough scrutiny of the data collected, it was possible to conclude that while many of the barriers to literacy participation are similar, the bread and butter issues need to be acknowledged by literacy providers when aiming to attract men into and retain them within the programme. The research also found that poverty, past negative experiences during the early school days, and stigma related issues, were the major inhibiting factors against men’s participation in the programme in the Mazowe district. Although the research had time related and operational limitations, these were however, repulsed by controls effected by the researcher. The diversity of qualitative data collecting instruments played a positive role in ensuring checks and balances in the type and authenticity of data collected. In order to retain male participants in the programme, a supportive environment is recommended. This can be achieved if voluntary literacy tutors are trained in design and delivery of instruction as well as in mobilizing strategies, so that they are sensitive to male participants’ circumstances. The income generating projects in which men are currently involved, need to be made more viable in order to boost their morale. / Educational Leadership and Management / D. Ed. (Education Management)
76

Influência da manteiga de karitê (Butyrospermum parkii), do dióxido de titânio e do p-metoxicinamato de octila sobre parâmetros físicos e eficácia in vitro de fotoprotetores labiais moldados / Influence of shea butter (Butyrospermum parkii), titanium dioxide and ethylhexyl methoxicinnamate on physical parameters and in vitro efficacy of lip molded photoprotectors

Sarruf, Fernanda Daud 28 March 2013 (has links)
Os mecanismos endógenos de proteção frente aos danos promovidos pelas radiações solares são insuficientes, tornando importante a utilização de formulações fotoprotetoras, corporais e labiais, para reduzir as lesões promovidas por tais radiações. Protetores labiais são preparações que protegem os lábios de fatores ambientais adversos e evitam o ressecamento. Citam-se, como exemplos, os fotoprotetores labiais, que protegem a mucosa labial das radiações ultravioleta A e B. Estes são compostos por filtros solares (compostos ativos), aditivos e agentes graxos, dentre outros, os quais podem exercer influência na eficácia fotoprotetora da preparação. Deste modo, estudar a influência da alteração quali e quantitativa de determinados componentes da fórmula na fotoproteção conferida pelo produto final é de grande valia para a melhoria da eficácia do fotoprotetor labial. Portanto, este trabalho objetivou o desenvolvimento de fotoprotetores labiais contendo manteiga de karitê (butyrospermum parkii) como composto bioativo, ethylhexyl methoxicinnamate como filtro solar orgânico e titanium dioxide como filtro solar inorgânico; a avaliação da estabilidade das preparações por meio da Avaliação Preliminar da Estabilidade; a caracterização organoléptica e física das preparações; e a determinação da eficácia fotoprotetora in vitro por espectrofotometria de refletância difusa com esfera de integração. Todas as balas foram consideradas estáveis. Dentre as variáveis estudadas, o titanium dioxide exerceu influência na maioria das respostas avaliadas (ponto de fusão por equipamento de ponto de fusão; valor de L*; valor de b*; distância máxima no teste de dureza; força máxima no cantilever test; valor de slope no cantilever test; razão UVA/UVB; fator de proteção solar; e porcentagem de transmitância). A manteiga de karitê exerceu influência nas respostas: distância máxima no teste de dureza; força máxima no cantilever test; e valor de slope no cantilever test (apenas a 25°C). O ethylhexyl methoxicinnamate influenciou nas respostas: distância máxima no teste de dureza; força máxima no cantilever test; valor de slope no cantilever test (apenas a 25°C); razão UVA/UVB; fator de proteção solar; e porcentagem de transmitância. Nenhuma das variáveis influenciou as respostas: valor de ponto de gota, DSC e a distância máxima no cantilever test. / The endogenous protection mechanisms against the damages promoted by solar radiations are insufficient. Therefore, the use of photoprotective formulations both corporal and labial, become important for the minimization of the lesions caused by these radiations. Lip protectors are preparations that protect the lips against adverse environmental conditions and avoid their dehydration. Photoprotective lipsticks may be cited as examples. These formulations protect the mucosa against ultraviolet A and B radiations. They are composed by solar filters (active compounds), addictives and fatty agents, amongst others, which may exert influence on the formulation\'s photoprotective efficacy. Therefore, the study of the influence of qualitative and quantitative alterations of certain components of the formula on the photoprotection supplied by the final product is greatly valuable for the efficacy improvement of a photoprotective lipstick. Hence, this research work aimed at the development of photoprotective lipsticks containing shea butter (butyrospermum parkii) as bioactive compound, ethylhexyl methoxicinnamate as organic filter and titanium dioxide as inorganic filter; the evaluation of formulations\' stability through the Preliminary Stability Test; physical and organoleptical characterization of the formulation; and the determination of the in vitro photoprotective efficacy by diffuse reflectance spectroscopy with integration sphere. All formulations were considered stable. Amongst the studied variables, titanium dioxide influenced the majority of the evaluated responses (melting point using melting point equipment; L* value; b* value; maximum distance on the hardness test; maximum strength on cantilever test; slope value on cantilever test; UVA/UVB ratio; sun protection factor; and transmittance percentage). Shea butter influenced: maximum distance on the hardness test; maximum strength on cantilever test; and slope value on cantilever test (only at 25°C). Ethylhexyl methoxicinnamate influenced: maximum distance on the hardness test; maximum strength on cantilever test; slope value on cantilever test (only at 25°C); UVA/UVB ratio; sun protection factor and transmittance percentage. None of the variables influenced drop point, DSC and maximum distance on the cantilever test.
77

Influência da manteiga de karitê (Butyrospermum parkii), do dióxido de titânio e do p-metoxicinamato de octila sobre parâmetros físicos e eficácia in vitro de fotoprotetores labiais moldados / Influence of shea butter (Butyrospermum parkii), titanium dioxide and ethylhexyl methoxicinnamate on physical parameters and in vitro efficacy of lip molded photoprotectors

Fernanda Daud Sarruf 28 March 2013 (has links)
Os mecanismos endógenos de proteção frente aos danos promovidos pelas radiações solares são insuficientes, tornando importante a utilização de formulações fotoprotetoras, corporais e labiais, para reduzir as lesões promovidas por tais radiações. Protetores labiais são preparações que protegem os lábios de fatores ambientais adversos e evitam o ressecamento. Citam-se, como exemplos, os fotoprotetores labiais, que protegem a mucosa labial das radiações ultravioleta A e B. Estes são compostos por filtros solares (compostos ativos), aditivos e agentes graxos, dentre outros, os quais podem exercer influência na eficácia fotoprotetora da preparação. Deste modo, estudar a influência da alteração quali e quantitativa de determinados componentes da fórmula na fotoproteção conferida pelo produto final é de grande valia para a melhoria da eficácia do fotoprotetor labial. Portanto, este trabalho objetivou o desenvolvimento de fotoprotetores labiais contendo manteiga de karitê (butyrospermum parkii) como composto bioativo, ethylhexyl methoxicinnamate como filtro solar orgânico e titanium dioxide como filtro solar inorgânico; a avaliação da estabilidade das preparações por meio da Avaliação Preliminar da Estabilidade; a caracterização organoléptica e física das preparações; e a determinação da eficácia fotoprotetora in vitro por espectrofotometria de refletância difusa com esfera de integração. Todas as balas foram consideradas estáveis. Dentre as variáveis estudadas, o titanium dioxide exerceu influência na maioria das respostas avaliadas (ponto de fusão por equipamento de ponto de fusão; valor de L*; valor de b*; distância máxima no teste de dureza; força máxima no cantilever test; valor de slope no cantilever test; razão UVA/UVB; fator de proteção solar; e porcentagem de transmitância). A manteiga de karitê exerceu influência nas respostas: distância máxima no teste de dureza; força máxima no cantilever test; e valor de slope no cantilever test (apenas a 25°C). O ethylhexyl methoxicinnamate influenciou nas respostas: distância máxima no teste de dureza; força máxima no cantilever test; valor de slope no cantilever test (apenas a 25°C); razão UVA/UVB; fator de proteção solar; e porcentagem de transmitância. Nenhuma das variáveis influenciou as respostas: valor de ponto de gota, DSC e a distância máxima no cantilever test. / The endogenous protection mechanisms against the damages promoted by solar radiations are insufficient. Therefore, the use of photoprotective formulations both corporal and labial, become important for the minimization of the lesions caused by these radiations. Lip protectors are preparations that protect the lips against adverse environmental conditions and avoid their dehydration. Photoprotective lipsticks may be cited as examples. These formulations protect the mucosa against ultraviolet A and B radiations. They are composed by solar filters (active compounds), addictives and fatty agents, amongst others, which may exert influence on the formulation\'s photoprotective efficacy. Therefore, the study of the influence of qualitative and quantitative alterations of certain components of the formula on the photoprotection supplied by the final product is greatly valuable for the efficacy improvement of a photoprotective lipstick. Hence, this research work aimed at the development of photoprotective lipsticks containing shea butter (butyrospermum parkii) as bioactive compound, ethylhexyl methoxicinnamate as organic filter and titanium dioxide as inorganic filter; the evaluation of formulations\' stability through the Preliminary Stability Test; physical and organoleptical characterization of the formulation; and the determination of the in vitro photoprotective efficacy by diffuse reflectance spectroscopy with integration sphere. All formulations were considered stable. Amongst the studied variables, titanium dioxide influenced the majority of the evaluated responses (melting point using melting point equipment; L* value; b* value; maximum distance on the hardness test; maximum strength on cantilever test; slope value on cantilever test; UVA/UVB ratio; sun protection factor; and transmittance percentage). Shea butter influenced: maximum distance on the hardness test; maximum strength on cantilever test; and slope value on cantilever test (only at 25°C). Ethylhexyl methoxicinnamate influenced: maximum distance on the hardness test; maximum strength on cantilever test; slope value on cantilever test (only at 25°C); UVA/UVB ratio; sun protection factor and transmittance percentage. None of the variables influenced drop point, DSC and maximum distance on the cantilever test.
78

Björkämnesförsörjning i ett möbelproducerande företag / Birch material procurement in a furniture producing company

Thörn, Andreas, Umeland, Christian January 2009 (has links)
Detta examensarbete handlar om hur ett möbelproducerande företags råmaterialförsörjning går till. Företaget som har varit värd för arbetet är ett möbeltillverkande företag som heter Stolab och ligger i Smålandstenar. Studiebesök och intervjuer har hos Stolab och deras leverantörer legat till grund för det arbete som vi har utfört. Ämnen som är behandlade är kvalitetsaspekter på råmaterialet samt hur relationerna mellan kund – leverantör fungerar. Arbetet fokuserar främst på den sista punkten, hur relationerna ser ut mellan kund leverantör, vilka möjligheter man har att förbättra kommunikationen mellan företagen och hur inköp och lagerhållning kan fungera. För att kunna förbättra kvaliteten på det råmaterial som kommer till företaget så är en viktig del i det att öka förståelsen för de krav som ställs. Kraven måste också kommuniceras på ett effektivt sätt. Vi har utarbetat en modell för hur detta samarbete kan gå till samt gett en del andra förslag till åtgärder för att kunna förbättra kvalitet på materialet och förbättra relationerna. / This final thesis deals with the hardwood raw material procurement in a furniture producing company. The company that has been our host is a furniture producing company called Stolab situated in Smålandstenar. The study visits and interviews we have completed has been the base of this work and the theory studies that we have made. Subjects that have been treated in this report are quality aspects on the raw material and also the relationships between customer and the supplier. The discussion is focused on the latest mentioned part, which possibilities there are to improve the communication between the companies and how purchase and store-keeping can work. To be able to improve the quality of the raw material that is being delivered to the company an important part is to gain the understanding of the demand that is set. The demands also need to be communicated in an efficient way. We have worked out a model which gives suggestions to motions to be made to improve the quality of the raw material and the relationships between customers and suppliers.
79

Björkämnesförsörjning i ett möbelproducerande företag / Birch material procurement in a furniture producing company

Thörn, Andreas, Umeland, Christian January 2009 (has links)
<p>Detta examensarbete handlar om hur ett möbelproducerande företags råmaterialförsörjning går till. Företaget som har varit värd för arbetet är ett möbeltillverkande företag som heter Stolab och ligger i Smålandstenar. Studiebesök och intervjuer har hos Stolab och deras leverantörer legat till grund för det arbete som vi har utfört. Ämnen som är behandlade är kvalitetsaspekter på råmaterialet samt hur relationerna mellan kund – leverantör fungerar. Arbetet fokuserar främst på den sista punkten, hur relationerna ser ut mellan kund leverantör, vilka möjligheter man har att förbättra kommunikationen mellan företagen och hur inköp och lagerhållning kan fungera. För att kunna förbättra kvaliteten på det råmaterial som kommer till företaget så är en viktig del i det att öka förståelsen för de krav som ställs. Kraven måste också kommuniceras på ett effektivt sätt. Vi har utarbetat en modell för hur detta samarbete kan gå till samt gett en del andra förslag till åtgärder för att kunna förbättra kvalitet på materialet och förbättra relationerna.</p> / <p>This final thesis deals with the hardwood raw material procurement in a furniture producing company. The company that has been our host is a furniture producing company called Stolab situated in Smålandstenar. The study visits and interviews we have completed has been the base of this work and the theory studies that we have made. Subjects that have been treated in this report are quality aspects on the raw material and also the relationships between customer and the supplier. The discussion is focused on the latest mentioned part, which possibilities there are to improve the communication between the companies and how purchase and store-keeping can work. To be able to improve the quality of the raw material that is being delivered to the company an important part is to gain the understanding of the demand that is set. The demands also need to be communicated in an efficient way. We have worked out a model which gives suggestions to motions to be made to improve the quality of the raw material and the relationships between customers and suppliers.</p>
80

The use and interpretation of the nutrition information on the food label of selected fat spreads by female consumers aged 25-45 years, living in Pietermaritzburg.

Wiles, Nicola Laurelle. January 2006 (has links)
Aim: To determine the use and interpretation of the nutrition information on the food label of selected fat spreads by female consumers aged 25 to 45 years, living in Pietermaritzburg. Objectives: This study set out to determine the following objectives regarding the food label: what the demographics of the consumers making use of the label were; how these consumers used the label and their motivation behind this label use and did the use of the label alter the purchase of that product? Method: One hundred and fifty women aged 25-45 years were chosen from an accidental, non-probability sample of consumers shopping at selected supermarkets within Pietermaritzburg. Respondents were presented with a four part questionnaire surrounding the purchase of selected fat spreads. Results: The greatest number of respondents were from the white population group (n = 65), followed by black respondents (n = 46), Indian respondents (n = 29) and then coloured respondents (n = 10). Results showed that the respondent who was most likely to use the nutrition information on the food label had a tertiary education; was a primary food purchaser, lived with other people, had more than R1000 a month to spend on food and was conscious of choosing the healthier option. Fifty five percent of this study sample (n = 82) claimed to use the nutrition information on the label to assist with purchases and 68% (n = 102) found the nutrition information important for purchasing a new product. Of the potential factors that have previously been found to impede the use of the nutrition information label:-inadequate print size, lack of education as well as lack of nutrition information on the food label were found to be factors restricting label use in this study. The most commonly used sources of nutrition information were the media as well as friends and family and the most trusted source was the Health Professional. Discussion: If the nutrition information is to be used both correctly and effectively, there must be a major educational campaign that sets out to meet the needs of the population that are most vulnerable, especially those with an inadequate education. Conclusion: The consumer most likely to use the nutrition information on the food label has a tertiary education, is a primary food purchaser with a large amount of money available for groceries and is conscious of choosing a healthier option. The label is most likely to be used when purchasing a fat spread for the first time. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.

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