Creep of single crystals and polycrystals of aluminum,lead, and tin

The activation energies for high temperature creep of single crystals and polycrystalline specimens of high purity aluminum, lead, and tin were determined by the technique involving the effect of abrupt changes in temperature on the creep rates. The data reveal that single crystals and polycrystalline specimens have the same high temperature activation energies. Furthermore, the activation energies for grain boundary shearing in aluminum and tin are equal to the respective activation energies for creep.     

CONSTRUCTED WETLANDS FOR MINEWATER TREATMENT: ENVIRONMENTAL BENEFITS AND ECOLOGICAL RECOVERY

The ecology of the River Pelenna (in South Wales) was impoverished by polluted discharges from abandoned coal mines. A series of passive constructed wetlands was created in order to treat these discharges and to improve the ecology of the river. A three-year Environment Agency R&D project investigated the performance, environmental benefits and sustainability of the constructed wetlands. It showed that the treatment systems were removing most of the iron contamination. In the reaches downstream from the minewaters, the dissolved-iron concentration quickly dropped below the target level. Invertebrate abundance, trout and riverine bird populations increased in following years. However, occasional overflows from the systems have significantly affected the ecology of one stretch of river. The research work has provided an insight into the potential for ecological recovery associated with future minewater treatment.     

Paired gang scheduling

Conventional gang scheduling has the disadvantage that when processes perform I/O or blocking communication, their processors remain idle because alternative processes cannot be run independently of their own gangs. To alleviate this problem, we suggest a slight relaxation of this rule: match gangs that make heavy use of the CPU with gangs that make light use of the CPU (presumably due to I/O or communication activity), and schedule such pairs together, allowing the local scheduler on each node to select either of the two processes at any instant. As I/O-intensive gangs make light use of the CPU, this only causes a minor degradation in the service to compute-bound jobs. This degradation is more than offset by the overall improvement in system performance due to the better utilization of the resources.     

How to avoid the transitional ax in indirect bad news messages

Professional communicators and managers can soften the tone of bad news messages by avoiding transitional axes, which are words and phrases that sever one section of the message from the next section. These words destroy any potential for goodwill between the sender and receiver of the message. The sender can avoid transitional axes in at least three ways: by using verbally keyed transitions such as repeated words, synonyms, specific naming, abbreviations, or generic nouns; by using cognitively keyed transitions that employ word and thought association to create implied connections; and by using traditional connectors such as conjunctions and conjunctive adverbs. Each of these techniques avoids use of the transitional ax and facilitates the exchange of bad news     

Heat resistance of Listeria monocytogenes

The heat resistance data on Listeria monocytogenes in culture media and foods are summarized. Most heat resistance data for foods have been obtained in dairy, meat, poultry, and egg products. Limited data have been published on seafood, fruits, and vegetables. The methodologies employed have evolved over time; hence data from earlier experiments are not directly comparable to more recent studies. Many factors influence the heat resistance of L. monocytogenes. Variation exists among different strains in their ability to withstand heat treatment. In addition, heat resistance is influenced by age of the culture, growth conditions, recovery media, and characteristics of foods such as salt content, a(w), acidity, and the presence of other inhibitors. Listeriae are more heat resistant than most other nonspore-forming foodborne pathogens, and thus, processing recommendations based on data from experiments with Salmonella spp. or pathogenic Escherichia coli may not be sufficient to eliminate similar numbers of L. monocytogenes. The data provided in this review may prove useful for food processors in determining appropriate times and temperatures for producing foods free of vegetative pathogens.