A Parametric Study on the Time-to-Failure of Wood Framed Walls in Fire

A model has been developed for predicting the time-to-failure of gypsum board clad wood framed walls exposed to fire. This model was developed for designing wood framed walls in accordance with new performance-based building fire codes being introduced around the world. The model has been used to undertake a parametric study of the effects of a wide range of variables on the time-to-failure due to structural collapse. The study found that the most dominant variables in building construction in descending order of importance are depth and breadth of stud sections, fire temperature, thickness of gypsum board, elastic modulus of wood in compression, enthalpy of gypsum board (that is the product density and specific heat) and vertical load. Variations in the thermal properties of wood do not dominate the influences affecting the time-to-failure. The study supports the component additive method for estimating the fire resistance of walls.     

Continuous monitoring of the activation and activity of [NiFe]-hydrogenases by membrane-inlet mass spectrometry

The hydrogen–deuterium (H⁺/D₂) exchange reaction catalysed by [NiFe]-hydrogenases in the D₂/H₂O system has been used to study enzyme activation and activity by membrane-inlet mass spectrometry. The activation of the [NiFe]-hydrogenases from Thiocapsa roseopersicina (HynSL), Desulfovibrio fructosovorans (HynSL), Desulfomicrobium baculatum (HysSL), Rhodobacter capsulatus (HupUV), and of the bidirectional tetrameric HoxFUYH enzymes from Synechocystis PCC 6308 (Gloeocapsa alpicola) and Anabaena variabilis ATCC 29413 was determined in response to oxygen depletion and to reductant addition (molecular hydrogen, reduced methyl viologen). Natural physiological activators (NADH, NADPH) of the bidirectional [NiFe] hydrogenases could also be identified by the H⁺/D₂ exchange reaction. The data are discussed in the light of current models of hydrogenase catalytic mechanism.     

Memory distortion in people reporting abduction by aliens.

False memory creation was examined in people who reported having recovered memories of traumatic events that are unlikely to have occurred: abduction by space aliens. A variant of the Deese/Roediger-McDermott paradigm (J. Deese, 1959; H. L. Roediger III & K. B. McDermott, 1995) was used to examine false recall and false recognition in 3 groups: people reporting recovered memories of alien abduction, people who believe they were abducted by aliens but have no memories, and people who deny having been abducted by aliens. Those reporting recovered and repressed memories of alien abduction were more prone than control participants to exhibit false recall and recognition. The groups did not differ in correct recall or recognition. Hypnotic suggestibility, depressive symptoms, and schizotypic features were significant predictors of false recall and false recognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Composting of Disposal Organic Wastes: Resource Recovery for Agricultural Sustainability

One of the major problems of agricultural soils in the tropical regions of the Pacific is the low organic matter content. Because of the hot and humid environment, the soil organic matter (SOM) is minimal due to rapid decomposition. Composted organic material is being applied on agricultural fields as an amendment to provide nutrients and enhance the organic matter content for improving the physical and chemical properties of the cultivated soils. In addition land application of composted material as a fertilizer source effectively disposes of wastes that otherwise are buried in landfills. In our soil program at the University of Guam, we are evaluating the use of organic material as an alternative to synthetic fertilizers. Its goal is to develop management strategies and use available resources for improving crop production while conserving resources and preserving environmental quality. Our case study project is designed to improve soil fertility status by using composted organic wastes and assessing how the nitrogen and other essential nutrients contribute to long-term soil fertility and crop productivity without application of synthetic fertilizers. In our pilot project, compost is produced from wood chips, grinded typhoon debris mixed with animal manure, fish feed, shredded paper and other organic wastes. Mature compost is then applied on the field at the rates of 0, 5, 10 and 20 t/ha as a soil amendment on the eroded cobbly soils of southern Guam. Corn is planted and monitored for growth performance and yield. The effect of land application of composted material on the SOM content and overall soil quality indices are being evaluated in this pilot study.     

Mechanism of localized corrosion of aluminum–silicon carbide composites in a chloride containing environment

In marine environments, more pits develop on SiC reinforced aluminum alloy composites than on their unreinforced counterparts. Although it has been suggested that the SiC plays an active role in composite corrosion by fostering the initiation of pits, this fact has not been conclusively demonstrated. The present paper considers data of two independent investigations concerning the effects of alloy type, and heat treatment on pit initiation in SiC reinforced aluminum composites. For four alloys, it is shown that pit initiation is dependent on the alloy type and heat treatment. Further, microscopic observations show that pit initiation sites are correlated with secondary phase particles. Results suggest that secondary phases, rather than the SiC particles, contribute to the pitting behavior of the composites.     

Mitigating the imitation of aggressive behaviors by changing children's attitudes about media violence.

In 2 experiments, 169 1st- and 3rd-graders selected because of their high exposure to TV violence, were randomly divided into an experimental and a control group. Over 2 yrs, the experimental Ss were exposed to 2 treatments designed to reduce the likelihood of their imitating the aggressive behaviors they observed on TV. The treatments involved teaching the Ss that (a) TV violence is an unrealistic portrayal of the real world, (b) aggressive behaviors are not as acceptable in the real world as they appear on TV, and (c) one should not behave like the aggressive characters seen on TV. The control group received comparable neutral treatments. By the end of the 2nd yr, the experimental Ss were rated as significantly less aggressive by their peers, and the relation between violence viewing and aggressiveness was diminished in the experimental group. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of a photometric method with standardized methods of antifungal susceptibility testing of yeasts

We determined the fluconazole MICs for 101 clinical isolates of Candida and Cryptococcus neoformans using the macro- and microdilution methods recommended by the National Committee for Clinical Laboratory Standards. We compared the MICs obtained by these methods with those obtained by a photometric assay that quantified the reduction of 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) by viable fungi. The MIC determined by this method was defined as the highest fluconazole concentration associated with the first precipitous drop in optical density. For Candida, both the MTT and the microdilution methods demonstrated excellent agreement with the standard macrodilution method. The MTT method, however, generated MICs at 24 h that were comparable to those generated by the standard macrodilution method, whereas the microdilution method required 48 h. For C. neoformans, the levels of agreement between the MICs determined by the MTT and microdilution methods after 48 h and those determined by the standard 72-h macrodilution method were 94% (29 of 31) and 94% (29 of 31), respectively. The MTT method therefore provided results comparable to those of currently recommended methods and had the advantages of a more rapid turnaround time and potential adaptability to use as an automated system. Furthermore, the MICs determined by the MTT method were determined photometrically, thereby eliminating reader bias.