No description available.

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 148-153). Also available via the Internet.

The Piedmont System is a collection of equipment for efficiently removing the juice from sweet sorghum stalks for the production of ethanol. The concept is to separate the whole stalks into pith and rind-leaf fractions, pass only the pith fraction through a screw press, and thus achieve an improvement in juice expression efficiency and press capacity. The operation of three alternative harvesting/processing systems were modeled and compared using computer simulation to determine which system could produce sweet sorghum juice and deliver it to a central plant at the lowest cost per liter of potential ethanol produced. In addition, an energy analysis was done to determine the net energy gain. System A cut the sorghum stalks and hauled them to a crossroads site where they could be stored up to 30 days before juice expression. System B separated the pith and rind-leaf fractions in the field, and juice expression was accomplished at a nearby site. No storage was possible for System B. System C cut the stalks like System A, but then a mobile processor moved through the field to separate the pith and rind-leaf fractions. It was found that the cost of producing feedstock with System C ($0.87/L) was significantly higher than either System A ($0.56/L) or System B ($0.63/L). While the System A cost was slightly lower than that of System B, it is recommended that both Systems A and B should be studied further since small adjustments to the model could eliminate the advantage of System A over System B. Increases in whole-stalk yield and juice sugar level would lower the cost of all three systems by as much as 43%. As the price of energy rises, sweet sorghum is expected to gain an economic advantage over com as a feedstock for ethanol, because of its higher energy ratio. If the by-products are used to produce ethanol through cellulose conversion, the overall energy ratio for sweet sorghum was calculated to be 1.1 compared to 0.8 for corn. The energy ratio if only liquid fuels are considered was 7.9 for sweet sorghum compared to 4.5 for corn. / Ph. D.

In general, traditional co-operatives suffer from free-rider, horizon, portfolio, control and influence problems that starve them of both equity and debt capital. Evidently, the factors which constrain agricultural development also inhibit co-operative development in the former homelands. These factors include socio-economic as well as political factors operating in the environment of the cooperatives. In addition to these external factors, co-operatives have several internal problems such as inefficient management and lack of understanding of the co-operative concept and principles. The New Cooperative Act No. 14 of 2005 was an attempt at addressing these fundamental problems. The purpose of this study was to analyze the extent towhich cooperatives organized on the basis of this new Act have performed and to ascertainwhether or not they have met the expectations of the policy makers. In order to address these issues a structured questionnaire was used to interview 100 farmers. Farmers were divided into two groups, one group consisting of fifty members and the other fifty non-members; all these farmers were randomly selected from Ndonga and Maqhashu in Lady frère. The study investigated and profiled the socio-economic situation of the communities of Ndonga and Maqhashu with particular emphasis on the employment and poverty situations, as well as the income earning opportunities in the communities. It also undertook a comparison of the members and non-members of the co-operatives in terms of their production results under the sorghum production programmes in the two communities.The data were analyzed by means of descriptive and inferential statistics which explain some measures of central tendency and dispersion as well as levels of significance. A t-test of independent samples was used to compare the means for the sorghum yields and revenues for non-members and members of the co-operative. Gross margin analysis was also used to determine the financial implications of cooperation for the smallholders. In addition, a multiple regression model and a discriminant function were fitted to determine the factors explaining the differences in performance of members and non-members of the cooperative society. The Gross Margin analysis shows that the cooperatives are operating at a loss, meaning they produce less with high production costs. However, the results also show that the Ndonga and Maqhashu sorghum co-operative did not benefit only its members but the whole community through significant job creation for the local population.