Master of Science / Department of Animal Sciences and Industry / Joel M. DeRouchey / Five experiments used 3,004 pigs to determine influences of wheat middlings (Midds), dried distillers grains with solubles (DDGS), and choice white grease (CWG) on growth, carcass traits, and carcass fat quality of finishing pigs and the optimal SID Trp:Lys in growing and finishing pigs fed 30% DDGS. In Exp. 1, pigs fed increasing dietary Midds had decreased (linear; P≤0.02) ADG and G:F. Feeding 30% DDGS did not influence growth performance. For carcass traits, increasing Midds decreased (linear; P<0.01) carcass yield, HCW, and backfat depth (quadratic; P<0.02) but increased (quadratic; P<0.01) FFLI. Feeding 30% DDGS decreased (P<0.03) carcass yield and backfat depth (P<0.01), but increased FFLI (P<0.02) and jowl fat IV (P<0.001). In Exp. 2, feeding 20% dietary Midds decreased (P<0.01) ADG and G:F. Pigs fed diets with increasing CWG had improved ADG (quadratic, P<0.03) and G:F (linear, P<0.01). Dietary Midds or CWG did not affect ADFI. For carcass traits, feeding 20% Midds decreased carcass yield (P<0.05), HCW, backfat depth, and loin depth, while increasing jowl fat IV (P<0.001). Pigs fed CWG also had decreased (linear, P<0.05) FFLI and increased (linear, P<0.01) jowl fat iodine value. In conclusion, feeding Midds reduced pig growth performance, carcass yield, and increased jowl fat IV. In Exp. 3, xylanase supplementation did not improve growth performance or carcass traits of pigs fed different dietary energy and fiber levels. Increasing dietary energy increased (linear; P<0.001) ADG and G:F with no affect on ADFI. Increasing dietary energy increased (linear; P<0.01) yield, HCW, backfat depth, and reduced FFLI (linear; P<0.001) and jowl fat iodine value (linear; P<0.001). Apparent total tract digestibility of ADF improved (P<0.002) with the addition of dietary xylanase; however, there were no differences in any other nutrient digestibility criteria. As dietary energy increased, there was an increase (linear; P<0.02) in apparent digestibility of DM, N, fat, GE, ADF, and NDF. In Exp. 4 and 5, results indicated the optimal SID Trp:Lys was 16.5% from 36.3 to 72.6 kg, but at least 19.5% from 72.6 to 120.2 kg in corn-soybean meal diets containing 30% DDGS.

Este trabalho discute as alterações micro-estruturais superficiais nos aços usinados por torneamento duro. Uma estrutura não aceita metalurgicamente, chamada de Camada Branca (\"White Layer\" - WL), é freqüentemente encontrada na superfície torneada. A presença desta camada branca depende dos parâmetros do processo de corte, especialmente do desgaste da ferramenta e da velocidade do corte. A formação da camada branca foi investigada no presente trabalho na face plana inferior de um anel de rolamento fabricada com o aço DIN 100Cr6, usinada por torneamento duro no estado temperado e revenido (dureza 60HRC). A profundidade foi medida usando as técnicas padrões metalográficas. As propriedades mecânicas da camada superficial (módulo de rigidez, E, e microdureza Vickers, HV) foram estimadas pelo método de microidentação instrumentada em uma amostra isenta da camada branca e em duas outras amostras, com camadas brancas de diferentes espessuras (respectivamente 7 e 12 mm de espessura). De acordo com a literatura a profundidade da camada branca aumenta de acordo com o desgaste da aresta da ferramenta. Este por sua vez aumenta com a velocidade de corte, mas atinge a saturação. Em outras palavras, a profundidade de corte tem pouco efeito sobre a profundidade da camada branca; porém aumentando o avanço da ferramenta de corte ocorre o aparecimento da mesma. Os presentes resultados confirmam um efeito do avanço da ferramenta sobre a espessura da WL, tal que quanto menor o avanço, maior é a espessura, porém não confirmam o efeito do desgaste da ferramenta. A formação desta camada é discutida no contexto da sua influência sobre a rugosidade das peças. / This work deals with the microstructural changes in the surface of steels machined by hard turning. A non-acceptable microstructure, called White Layer - WL, is usually found in the hard turned surface. The presence of the white layer depends on hard turning parameters, especially on the wear of the machining tool and cutting speed. The formation of the white layer was investigated in the present work by hard turning the inferior face of a roller-bearing ring fabricated with DIN 100Cr6 steel quenched and tempered (60 HRC hardness). The depth of the WL was measured by standard metallographic procedures. The mechanical properties (stiffness modulus, E, and Vickers hardness) of the surface layer were measured by intrumented indentation in three samples: one with no WL, and two containing a WL of respectively 7 and 12 mm. According to the literature the depth of the WL increases with the wear of the machining tool. This increased with cutting speed, but reaches saturation. The presentresults confirm an effect of tool advance upon the depth of the WL, such that decreasing the advance leads to an increase in its depth, but an effect of tool wear could not be recognized. The formation of the WL is discussed in the context of its effect on surface roughness.

No description available.

Abstract not available

The removal of the transportation subsidy on western Canadian grain has resulted in a relative shift in competitiveness from grain to livestock production in Saskatchewan. Feedlot managers indicated that they fed cattle at a lower cost than their Alberta competitors. They suggested their feeding advantage is in the range of $45 to $75 per animal. Yet this supposed feeding advantage has not resulted in an increase in cattle being finished in the province. In fact statistics show that there has been a decrease in the number of cattle finished in Saskatchewan since the removal of the transportation subsidy. This thesis investigated potential hindrances to developing feedlots in Saskatchewan. Interviews with 17 Saskatchewan feedlot managers were conducted in 2001. These feedlot managers suggested that lack of financing was a hindrance to feedlot development in Saskatchewan. They sited provincial land and labour laws, a grain production bias and feeding risk as potential reasons for lack of investment in the feedlot sector. The interviews with these 17 feedlot managers led to an investigation of transaction costs in buying and selling cattle. A theoretical framework was developed in this thesis to measure transaction costs. Then some empirical evidence was calculated from transaction cost estimates provided by five finishing feedlots that indicated larger feedlots have lower transaction costs in buying and selling cattle than smaller feedlots.

The removal of the transportation subsidy on western Canadian grain has resulted in a relative shift in competitiveness from grain to livestock production in Saskatchewan. Feedlot managers indicated that they fed cattle at a lower cost than their Alberta competitors. They suggested their feeding advantage is in the range of $45 to $75 per animal. Yet this supposed feeding advantage has not resulted in an increase in cattle being finished in the province. In fact statistics show that there has been a decrease in the number of cattle finished in Saskatchewan since the removal of the transportation subsidy. This thesis investigated potential hindrances to developing feedlots in Saskatchewan. Interviews with 17 Saskatchewan feedlot managers were conducted in 2001. These feedlot managers suggested that lack of financing was a hindrance to feedlot development in Saskatchewan. They sited provincial land and labour laws, a grain production bias and feeding risk as potential reasons for lack of investment in the feedlot sector. The interviews with these 17 feedlot managers led to an investigation of transaction costs in buying and selling cattle. A theoretical framework was developed in this thesis to measure transaction costs. Then some empirical evidence was calculated from transaction cost estimates provided by five finishing feedlots that indicated larger feedlots have lower transaction costs in buying and selling cattle than smaller feedlots.

Rolling technology can control the thickness precisely. But it isn¡¦t available in width control. FEM software DEFORM 3D is adopted to simulate one stand of the hot finishing rolling process using carbon steel as sheet material. Stress, strain and width spread are discussed. Regression analysis is used to find an empirical equation for rolling load and width spread. Experiment and simulation of cold strip rolling using aluminum as sheet material are conducted,discussing the width spread and detail of width transformation in DEFORM 3D.From the comparisons between analytical and experimental width spread, the analytical model and prediction equation are validated.

Currently in Taiwan¡¦s textile-dying industry, sodium hypochlorite (NaOCl) is popularly used as a decolorization oxidant. In order to surely meet the effluent color regulation of 550 ADMI (American Dye Manufactures Institute), excessive dosage of sodium hyperchlorite is commonly used, which results in the increase of residual chloride and the accumulation of toxic chlorinated compound in the environment. This study probes into the characteristics of substitute oxidant for sodium hypochlorite to avoid the production of toxic products. The study includes decolorization efficiency evaluation, economical analysis and feasibility of commercial application. This study adopts ozone as an oxidant and ultraviolet light as the oxidant enhancer for the purpose of preventing the occurrence of secondary pollution products like trihalomethane from the sodium hyperchlorite application. Literature review indicates that there are several studies for reaction mechanisms of oxidation and disinfection of ozone and ultraviolet light for decolorization and the conclusions reveal much promising results. There are three topics in this study, which are: Topic 1: Feasibility study. This study focuses on whether the effluent color concentration of the treatment process meets the color effluent standard or not. A 3.5 L volume reactor was used in this section. Topic 2: Influencing factor analysis. A 14 L volume reactor was adopted for analyzing the influencing factors for decolorization and for comparing the differences in treatment efficiencies between a dye finishing plant effluent and two commercial dyestuff samples. Topic 3: Economic analysis. The analysis focuses on economic comparison between NaOCl and UV/Ozone processes for effluent decolorization. Analysis results of the investment cost, operation/maintenance expense, and investment return duration are presented in this section. A 50 L volume reactor was used to achieve the evaluation for this part. First topic of this study examined some operating parameters for treating effluent from the biological and chemical coagulation units of a dye-finishing wastewater treatment plant using the UV/Ozone technique to meet an effluent regulation of 550 ADMI values could be reduced from approximately 4,000 to 200 ADMI in an hour using the UV/Ozone technique. The results show that higher color removal efficiency could be achieved at pH values around 3 as compared with higher pH values of around 7 and 10. This might be due to the fact that the predominant ozone molecules at lower pH values are more selective to certain chromophore molecules in wastewater, despite the fact that hydroxyl radicals are predominant at higher pH values and have a stronger oxidation capability than ozone. The UV light used in this study emitted from the experimental lamp can excite oxygen and water molecules to produce ozone molecules and hydroxyl radicals that can then increase decolorization rate. The findings of this investigation reveal that the proposed UV/Ozone treatment scheme has potential for development into an environmentally friendly decolorization approach for dye finishing wastewater treatment. The second topic is to investigate the feasibility of applying UV/Ozone techniques to reduce color content caused by two commercial reactive dyes (Orange-13 and Blue-19). Bench experiments were performed using a 14-L reactor. Controlling factors including pH value, dosage of ozone, reaction time, and UV intensity were evaluated to obtain the optimal operating parameters. Results from this study show that the ozone dosage and pH value dominated the effects on the decolorization process. However, UV intensity shows relatively insignificant effects. Results also indicate that the color content could be reduced from 2,000 to 200 ADMI within a reaction time of 30 minutes with a total ozone dosage of 100 mg/L. This study shows that pH values of approximately 3 and 10 favored the decolorization of the studied Dye Blue-19 and Orange-13, respectively. This was due to the effects that molecular ozone and hydroxyl radicals had significant oxidative power at low and high pH, respectively. Moreover, molecular ozone was more selective to certain dye structures during its oxidation process. This also caused the effect that pH value played an important role on color removal. Kinetic analyses show that the decolorization reactions of Dye Orange-13 and Blue-19 followed a first-order decolorization model. Experimental results also indicate that the degree of decolorization was primarily proportional to the ozone dosage. Results from this study provide us an insight into the characteristics and mechanisms of decolorization by UV/ozone technique. Results will also aid in designing a system for field application of dye finishing plants. According to the results from the third topic, for a dye finishing plant of wastewater flow rate of 800CMD (m3/day), the capital cost of equipment and related establishment as well as amendment is about US$ 116,300, and the monthly operation and maintenance cost is US$ 4,030. In this study, ozone was used as a substitute decolorizing oxidant to treat the effluent from the secondary biological and physical/chemical treatment plant. Because the current cost for the decolorization oxidant (NaOCl) is approximately US$ 5,700 per month, the monthly saving, adopting the decolorization system using UZ/Ozone, will be US$ 1,670. The investment return period will be over 7 years and is not attractive to the plant owners. However, to prevent the accumulated toxicity of chloride compounds in the environment and to promote the desires of investment on the advanced decolorization technique, a favorable tax deduction policy needs to be applied.

Recently, the accuracy of hot strip gage is strictly demanded, and the strip thickness becomes the most important quality in hot strip rolling. It is well known that the accuracy of final strip thickness in the hot strip mill depends on the gage control performance at each stand. In order to improve the quality of the hot strip gage and reduce the strip thickness deviation , the Automatic Gage Control(A.G.C) system now is widely used in modern hot strip mills of the world. In this paper, the principle of feedforward control strategy in the AGC system is discussed and it¡¦s control performance is deeply analyzed. Besides, based on the study of comprehensively mathematical model and the establishment of simulator, the mathematical analysis and the simulation result can clarify the influence of the control system on strip thickness.

Thesis (Ph. D.)--Institute of Paper Chemistry, 1949. / Includes bibliographical references (p. 104-106).