Grading and sorting as a method of market segmentation for agricultural products

The concepts of market segmentation, grading and sorting are outlined and criteria are proposed. The application of these criteria to the sorting of cucumbers and tomatoes did not achieve effective market segmentation, and quality grading was only partially achieved. (Abstract retrieved from CAB Abstracts by CABI’s permission

Farmer cooperatives in the food economy of Western Europe: an analysis from the Marketing point of view

This paper is concerned with an analysis of farmer cooperatives in Western Europe from the marketing point of view. The analysis is restricted to marketing and processing cooperatives. First some basic characteristics of farmer cooperatives are discussed from a systems point of view. Afterwards changes in the environment of farmer cooperatives are reviewed. Their impact on farmer cooperatives is analysed. Finally some hypotheses on future developments of West European cooperatives are presented. Our analysis suggests that West European cooperatives will become increasingly hybrid systems, being democratic in the general policy stage and hierarchical in the executive stag

Basis for equivalent fluence concept in space solar cells

The equivalent fluence concept is defined, and its use and potential problems are noted. Silicon and GaAs solar cells are compared in a radiation environment. The analysis indicates that valid equivalent fluence values may be easier to obtain in GaAs than in silicon

Thin N-I-P radiation resistant solar cells

Several sets of N-I-P sola cells were fabricated from high resistivity silicon to test the effectiveness of various methods for hardening these devices against radiation. Different substrate materials were used to provide information on the effects of dopant concentration, silicon type, and the presence of oxygen. In some cells, P-type float-zone refined silicon of 800, 8000 and 15,000 omega-cm resistivity was used to provide a basis for studying resistivity and purity effects. In other cells, N-type silicon (approximately 800 omega-cm) was used to allow a comparison of dopant type. Oxygen-rich, crucible-grown, silicon (approximately 100 omega-cm, p-type) will provide information on purity effects and defect gettering. Lithium was introduced into different types of silicon to determine if mobile ions can reduce radiation induced defects in high resistivity material. Thin cells (2 mil) were fabricated to study the effects of cell thickness and carrier injection on radiation damage. The electrical characteristics of the different sets of cells were measured, analyzed, and compared prior to shipment of the cells to NASA/Lewis for irradiation

Silicon research and technology

The development of solar cells suitable for space applications are discussed, along with the advantages and disadvantages of silicon and gallium arsenide solar cells. The goal of a silicon solar cell with 18% efficiency has not been reached and does not appear promising in the near future