Waste heat utilization from a direct cycle high temperature gas cooled nuclear reactor for district heating and air conditioning

An analysis was conducted to determine the economic as well as technical feasibility of waste heat utilization from the proposed direct cycle high temperature gas cooled nuclear reactor, as designed by the General Atomic Company. The rejected heat from this system is at considerably higher temperatures than those normally encountered in conventional steam-electric Rankine cycles. By taking advantage of these higher rejection temperatures, heat was translated into energy available to a district heating and air conditioning service. The transportation of this energy was considered to be in the form of heated and chilled water. A refrigeration capacity on the order of 100,000 Tons and a heating capability of 5.0 x 10 9 BTU/hr at a distance of 70 miles was found to be a possibility. An economic analysis using a discounted cash flow technique, indicated that most of the systems analyzed could be profitable ventures. During the operation of the district heating and air conditioning network, overall utilization of the total reactor heat generation would be in excess of 80.0 per cent --Abstract, page ii

Why Do We Let Our Soil Erode?

This is the third report on the progress being made in erosion control in western Iowa. Soil losses have been reduced, but they still exceed levels that operators themselves believe necessary to maintain soil productivity

Soil erosion control in western Iowa: progress and problems

The study on which this analysis is based was concerned with the socio-economic factors that prevented erosion control in western Iowa from coinciding with goals of erosion-control programs. Information was obtained by personal interview from 138 farm operators and 49 nonoperating owners of farms in the area in 1957 in a continuing investigation of the obstacles preventing adoption of erosion-control practices and of possible remedies for these obstacles. The same sample of farms had been included in two previous studies in 1949 and 1952. Data from these three studies were used to analyze the effects of changes in obstacles to erosion control on changes in soil loss. The average estimated annual soil loss for the sample decreased from 21.1 to 14.1 tons per acre from 1949-57. In an effort to determine why the 5- ton-per-acre goal of public programs in the area had not been attained in 1957, multiple variable linear regression was used to analyze the relationships between obstacles, farm characteristics and soil losses. The statistically significant obstacles preventing the reduction of soil losses by farm operators were (1) operators\u27 need for immediate income, (2) their failure to see the need for recommended practices (custom and inertia) and (3) field and road layout of the farms. Characteristics which explained a significant amount of variation in the estimated soil loss were (1) topography of the farm, (2) soil conservation district participation, (3) the operator\u27s ability to borrow funds for erosion-control practices, (4) days of off-farm work and (5) recognition of the seriousness of the erosioncontr01 problem by farm operators. While not statistically significant, the most important obstacles for nonoperating landowners were (1) need for immediate income and (2) insufficient roughage-consuming livestock on tenant-operated farms

Soil erosion and some means for its control

The control of soil erosion on the many farms where it is still a problem would not be difficult if it required only an understanding of the critical physical relationships between climate, topography, plant cover, water and soil as well as an ability to prescribe the proper engineering and agronomic measures for each situation. Soil losses, when greatly in excess of those produced by natural geological processes, result from the use of particular farming practices and cropping systems. While an understanding of the physical conditions which produce this erosion is essential, so is an understanding of the reasons that farmers choose the methods of farming which expose their soil to the hazard of heavy erosion losses.https://lib.dr.iastate.edu/specialreports/1027/thumbnail.jp

Mice with genetic deletion of group VIA phospholipase A2β exhibit impaired macrophage function and increased parasite load in Trypanosoma cruzi-induced myocarditis

Trypanosoma cruzi infection, which is the etiological agent of Chagas disease, is associated with intense inflammation during the acute and chronic phases. The pathological progression of Chagas disease is influenced by the infiltration and transmigration of inflammatory cells across the endothelium to infected tissues, which are carefully regulated processes involving several molecular mediators, including adhesion molecules and platelet-activating factor (PAF). We have shown that PAF production is dependent upon calcium-independent group VIA phospholipase A(2)β (iPLA(2)β) following infection of human coronary artery endothelial cells (HCAECs) with T. cruzi, suggesting that the absence of iPLA(2)β may decrease the recruitment of inflammatory cells to the heart to manage parasite accumulation. Cardiac endothelial cells isolated from iPLA(2)β-knockout (iPLA(2)β-KO) mice infected with T. cruzi demonstrated decreased PAF production compared to that by cells isolated from wild-type (WT) mice but demonstrated increases in adhesion molecule expression similar to those seen in WT mice. Myocardial inflammation in iPLA(2)β-KO mice infected with T. cruzi was similar in severity to that in WT mice, but the iPLA(2)β-KO mouse myocardium contained more parasite pseudocysts. Upon activation, macrophages from iPLA(2)β-KO mice produced significantly less nitric oxide (NO) and caused less T. cruzi inhibition than macrophages from wild-type mice. Thus, the absence of iPLA(2)β activity does not influence myocardial inflammation, but iPLA(2)β is essential for T. cruzi clearance