Hot filament technique for measuring the thermal conductivity of molten lithium fluoride

Molten salts, such as lithium fluoride, are attractive candidates for thermal energy storage in solar dynamic space power systems because of their high latent heat of fusion. However, these same salts have poor thermal conductivities which inhibit the transfer of heat into the solid phase and out of the liquid phase. One concept for improving the thermal conductivity of the thermal energy storage system is to add a conductive filler material to the molten salt. High thermal conductivity pitch-based graphite fibers are being considered for this application. Although there is some information available on the thermal conductivity of lithium fluoride solid, there is very little information on lithium fluoride liquid, and no information on molten salt graphite fiber composites. This paper describes a hot filament technique for determining the thermal conductivity of molten salts. The hot filament technique was used to find the thermal conductivity of molten lithium fluoride at 930 C, and the thermal conductivity values ranged from 1.2 to 1.6 W/mK. These values are comparable to the slightly larger value of 5.0 W/mK for lithium fluoride solid. In addition, two molten salt graphite fiber composites were characterized with the hot filament technique and these results are also presented

Cost effective control of urban smog. A report of a conference held at the Federal Reserve Bank of Chicago, June 7-8, 1993

Environmental protection

Statistical modeling of agricultural chemical occurrence in midwestern rivers

Agricultural chemicals in surface water may constitute a human health risk or have adverse effects on aquatic life. Recent research on unregulated rivers in the midwestern USA documents that elevated concentrations of herbicides occur for 1–4 months following application in late spring and early summer. In contrast, nitrate concentrations in unregulated rivers are elevated during fall, winter, and spring months. Natural and anthropogenic variables of river drainage basins, such as soil permeability, amount of agricultural chemicals applied, or percentage of land planted in corn, affect agricultural chemical concentration and mass transport in rivers. Presented is an analysis of selected data on agricultural chemicals collected for three regional studies conducted by the US Geological Survey. Statistical techniques such as multiple linear and logistic regression were used to identify natural and anthropogenic variables of drainage basins that have strong relations to agricultural chemical concentrations and mass transport measured in rivers. A geographic information system (GIS) was used to manage and analyze spatial data. Statistical models were developed that estimated the concentration, annual transport, and annual mean concentration of selected agricultural chemicals in midwestern rivers. Multiple linear regression models were not very successful (R2 from 0.162 to 0.517) in explaining the variance in observed agricultural chemical concentrations during post-planting runoff. Logistic regression models were somewhat more successful, correctly matching the observed concentration category in 61–80% of observations. Linear and multiple linear regression models were moderately successful (R2 from 0.522 to 0.995) in explaining the variance in observed annual transport and annual mean concentration of agricultural chemicals. Explanatory variables that were commonly significant in the regression models include estimates of agricultural chemical use, crop acreage, soil characteristics, and basin topography

Devising a Compliance Strategy under the ISO 14000 International Environmental Management Standards

Two principal factors, the complexity of environmental regulation and the growing propensity of governments to criminalize infractions, have prompted companies conducting business in the United States and elsewhere to develop management strategies to assess and ensure compliance. There is a contemporaneous business movement afoot to measure and continuously improve environmental performance as a means not only to limit liability, but also to attain higher levels of efficiency, drive down costs, and ultimately, to get the best of the competition. Ongoing efforts to formulate standardized approaches to environmental management, such as the ISO 14001 environmental management system (EMS) designed by the International Organization for Standardization, are in part a response to these imperatives. This Article emphasizes the importance of a well-conceived corporate compliance program for companies in the present business and enforcement climate. It begins by examining the evolution of criminal environmental law and suggests ways firms can minimize the threat of prosecution. Following that discussion is a brief survey of the \u27\u27beyond compliance movement, focusing on the role of compliance auditing in ISO 14000 and other EMS programs. The Article concludes with several ideas on EMS design and, more specifically, how to integrate compliance program elements within a comprehensive EMS

Temperature and salinity tolerances of young Gulf of California grunion, Leuresthes sardina (Atheriniformes: Atherinidae)

Temperature and salinity tolerances were determined for laboratory-reared larval and juvenile Gulf of California grunion, Leuresthes sardina. The fish were hatched in the laboratory from artificially fertilized eggs obtained from spawning adults captured with a beach seine...

Hypersensitivity Pneumonitis Associated with Environmental Mycobacteria

A previously healthy man working as a machine operator in an automotive factory developed respiratory symptoms. Medical evaluation showed abnormal pulmonary function tests, a lung biopsy showed hypersensitivity pneumonitis, and his illness was traced to his work environment. His physician asked the employer to remove him from exposure to metalworking fluids. Symptoms reoccurred when he was later reexposed to metalworking fluids, and further permanent decrement in his lung function occurred. Investigation of his workplace showed that five of six large reservoirs of metalworking fluids (cutting oils) grew Mycobacterium chelonae (or Mycobacterium immunogenum), an organism previously associated with outbreaks of hypersensitivity pneumonitis in automaking factories. His lung function remained stable after complete removal from exposure. The employer, metalworking fluid supplier, union, and the National Institute for Occupational Safety and Health were notified of this sentinel health event. No further cases have been documented in this workplace