Consequences of catastrophic releases of ignited and unignited hydrogen jet releases

The possibility of using a risk based approach for the safe installation and siting of stationary fuel cell systems depends upon the availability of normative data and guidance on potential hazards, and the probabilities of their occurrence. Such guidance data is readily available for most common hydrocarbon fuels. For hydrogen, however, data is still required on the hazards associated with different release scenarios. This data can then be related to the probability of different types of scenarios, from historical fault data, to allow safety distances to be defined and controlled using different techniques. Some data on releases has started to appear but this data generally relates to hydrogen vehicle refuelling systems that are designed for larger throughput, higher pressures, and the general use of larger pipe diameters than are likely to be used for small fuel cell systems.The aim of this paper is to report on work that is providing data for informing safety distances for high-pressure components/fuel cell systems and associated fuel storage. Using high-pressure release scenarios, the extent of the clouds, jets and, following ignition, fires and explosions were investigated.     

Surface charge and stress in the Si/SiO2 system

A model for the stress distribution in thermally oxidised silicon slices has been developed using beam theory and bimetallic strip theory. The stresses have been confirmed by making lattice parameter measurements on oxidised silicon using the APEX X-ray diffraction technique. The often suggested relationship between the surface charge density at the Si/SiO₂ interface and the stress in the silicon surface has been investigated and shown to be inconsistent. Finally, analysis of the variation of surface charge density with oxide thickness has caused us to postulate the presence of both positively and negatively charged centres at the interface.     

(11<Emphasis Type="Italic">Z</Emphasis>,13<Emphasis Type="Italic">E</Emphasis>)-Hexadecadien-1-yl Acetate: Sex Pheromone of the Grass Webworm <Emphasis Type="Italic">Herpetogramma licarsisalis</Emphasis>—Identification,Synthesis, and Field Bioassays

The grass webworm Herpetogramma licarsisalis (Lepidoptera: Crambidae), which has recently established in pasture in Northland, New Zealand, is an important pest of many tropical and subtropical grasses. Two pheromone components, (Z)-11-hexadecen-1-yl acetate (Z11–16:Ac) and (11Z,13E)-hexadecadien-1-yl acetate (Z11,E13–16:Ac), were identified in pheromone gland extracts of female moths by gas chromatography (GC), GC-electroantennographic detection, and GC-mass spectrometry in conjunction with microchemical tests (dimethyldisulfide and 4-methyl-1,2,4-triazoline-3,5-dione derivatizations). Z11,E13–16:Ac and its geometric isomer (11E,13Z)-hexadecadien-1-yl acetate (E11,Z13–16:Ac) were synthesized via stereoselective Wittig reactions, and the identity of the diene present in the pheromone glands was confirmed to be Z11,E13–16:Ac. Field bioassays at Indooroopilly in Brisbane, Australia, established that Z11,E13–16:Ac was necessary and sufficient for attraction of male grass webworm moths and that the corresponding alcohol, (11Z,13E)-hexadecadien-1-ol (Z11,E13–16:OH), had a strong inhibitory effect on trap catches at the ratios tested. When mixed with Z11,E13–16:Ac in various ratios, Z11–16:Ac had no effect on the attractiveness of lures. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Identifying discriminating variables between teachers who fully integrate computers and teachers with limited integration

Given the prevalence of computers in education today, it is critical to understand teachers’ perspectives regarding computer integration in their classrooms. The current study surveyed a random sample of a heterogeneous group of 185 elementary and 204 secondary teachers in order to provide a comprehensive summary of teacher characteristics and variables that best discriminate between teachers who integrate computers and those who do not. Discriminant Function Analysis indicated seven variables for elementary teachers and six for secondary teachers (accounting for 74% and 68% of the variance, respectively) that discriminated between high and low integrators. Variables included positive teaching experiences with computers; teacher’s comfort with computers; beliefs supporting the use of computers as an instructional tool; training; motivation; support; and teaching efficacy. Implications for support of computer integration in the classroom are discussed.     

Effects of 28 days of resistance exercise and consuming a commercially available pre-workout supplement, NO-Shotgun?, on body composition, muscle strength and mass, markers of satellite cell activation, and clinical safety markers in males

Purpose  

This study determined the effects of 28 days of heavy resistance exercise combined with the nutritional supplement, NO-Shotgun^?, on body composition, muscle strength and mass, markers of satellite cell activation, and clinical safety markers.     

Acute effects of ingesting Java Fit™ energy extreme functional coffee on resting energy expenditure and hemodynamic responses in male and female coffee drinkers

Background  

The purpose of this study was to examine the effects of a functional coffee beverage containing additional caffeine, green tea extracts, niacin and garcinia cambogia to regular coffee to determine the effects on resting energy expenditure (REE) and hemodynamic variables.     

The effects of creatine ethyl ester supplementation combined with heavy resistance training on body composition, muscle performance, and serum and muscle creatine levels

Numerous creatine formulations have been developed primarily to maximize creatine absorption. Creatine ethyl ester is alleged to increase creatine bio-availability. This study examined how a seven-week supplementation regimen combined with resistance training affected body composition, muscle mass, muscle strength and power, serum and muscle creatine levels, and serum creatinine levels in 30 non-resistance-trained males. In a double-blind manner, participants were randomly assigned to a maltodextrose placebo (PLA), creatine monohydrate (CRT), or creatine ethyl ester (CEE) group. The supplements were orally ingested at a dose of 0.30 g/kg fat-free body mass (approximately 20 g/day) for five days followed by ingestion at 0.075 g/kg fat free mass (approximately 5 g/day) for 42 days. Results showed significantly higher serum creatine concentrations in PLA (p = 0.007) and CRT (p = 0.005) compared to CEE. Serum creatinine was greater in CEE compared to the PLA (p = 0.001) and CRT (p = 0.001) and increased at days 6, 27, and 48. Total muscle creatine content was significantly higher in CRT (p = 0.026) and CEE (p = 0.041) compared to PLA, with no differences between CRT and CEE. Significant changes over time were observed for body composition, body water, muscle strength and power variables, but no significant differences were observed between groups. In conclusion, when compared to creatine monohydrate, creatine ethyl ester was not as effective at increasing serum and muscle creatine levels or in improving body composition, muscle mass, strength, and power. Therefore, the improvements in these variables can most likely be attributed to the training protocol itself, rather than the supplementation regimen.     

Anomalous diffusion effects in silicon (a review)

This paper is concerned with anomalous diffusion effects in silicon, and particularly with the emitter-dip (or push-out) effect, which occurs in diffused transistors. Several possible mechanisms may be involved in anomalous diffusion and each is discussed, together with relevant experimental and theoretical work. Literature directly on the emitter-dip effect is next reviewed, and finally the author suggests fields of research which may clarify the mechanism or mechanisms involved.     

Pulsatile growth hormone and prolactin: effects of (+) butaclamol, a dopamine receptor blocking agent

Growth hormone (rGH) and prolactin (rPRL) secretory profiles were obtained before and after treatment with a dopamine receptor blocking agent, (+) butaclamol, in 10 male rats chronically implanted with right atrial cannulae. Mean rGH plasma concentrations, determined by planimetry, were reduced (202 +/- 20 ng/ml vs. 135 +/- 20ng/ml, P less than .01), but the basic configuration and periodicity of rGH secretory bursts were unaltered. Mean rPRL plasma concentrations were elevated (11.1 +/- 2.1 ng/ml vs 65.5 +/- 8.1 ng/ml, P less than .0005), but rPRL episodic secretion was still apparent. It is concluded that dopaminergic neurons have a minor role in facilitating episodic rGH secretion. Furthermore, persisting episodic rPRL secretion in rats administered a dopamine antagonist suggests that rPRL feedback inhibition does not inactivitate the neural mechanism generating episodic rPRL secretion.