X-ray CT analysis after blast of composite sandwich panels

Four composite sandwich panels with either single density or graded density foam cores and different face-sheet materials were subjected to full-scale underwater blast testing. The panels were subjected to 1kg PE4 charge at a stand-off distance of 1 m. The panel with graded density core and carbon fiber face-sheets had the lowest deflection. Post-blast damage assessment was carried out using X-ray CT scanning. The damage assessment revealed that there is a trade-off between reduced panel deflection and panel damage. This research has been performed as part of a program sponsored by the Office of Naval Research (ONR)

Thermal control system corrosion study

During the development of an expert system for autonomous control of the Space Station Thermal Control System (TCS), the thermal performance of the Brassboard TCS began to gradually degrade. This degradation was due to filter clogging by metallic residue. A study was initiated to determine the source of the residue and the basic cause of the corrosion. The investigation focused on the TCS design, materials compatibility, Ames operating and maintenance procedures, and chemical analysis of the residue and of the anhydrous ammonia used as the principal refrigerant. It was concluded that the corrosion mechanisms involved two processes: the reaction of water alone with large, untreated aluminum parts in a high pH environment and the presence of chlorides and chloride salts. These salts will attack the aluminum oxide layer and may enable galvanic corrosion between the aluminum and the more noble stainless steel and other metallic elements present. Recommendations are made for modifications to the system design, the materials used, and the operating and maintenance procedures, which should largely prevent the recurrence of these corrosion mechanisms

Laser-Doppler gas-velocity instrument

Three-D instrument using a laser light source measures both turbulence and mean velocity of subsonic and supersonic gas flows. This instrument is based on the measurement of the Doppler frequency shift of light waves scattered by moving particles in the gas stream

Laser Doppler velocity instrument

Laser Doppler velocity instrument for measuring turbulence and mean velocity in subsonic and supersonic gas flow

Are multimedia resources effective in life science education? A meta-analysis.

Multimedia learning is widely used in life science education where the use of pictures and text can bring complex structures and processes to life. However the impact on academic performance and deeper understanding is not well documented. We therefore carried out a systematic review to evaluate the effectiveness of multimedia resources in tertiary level life science education. Comprehensive literature searches were conducted; studies were selected based on stringent pre-set criteria, and data were extracted for meta-analysis. In total, 17 studies were used in the meta-analyses with a total population of 2,290 students. The results show that, when used as a substitute for laboratory practicals, multimedia improved student learning gains assessed with an end-of-year examination, (mean difference 7.06, ±4.61). Although it did not improve short-term learning gains in this scenario, multimedia improved learning gains in 10 of the 16 sub-group comparisons made across all the studies. Overall, multimedia learning was more effective than many traditional educational methods although the numbers of studies included in the analysis were ultimately considered to be small due to many exclusions from the studies included in the analysis. Therefore, more good quality trials are required to evaluate a broader range of scenarios relevant to modern practices. Studies would benefit from being rigorous in design with good quality reporting of all aspects of methodology and study results.HEA Subject Centre for Bioscienc

Feeding Modified Distillers Grains With Solubles and Wet Corn Gluten Feed (Synergy) to Adapt Cattle to Finishing Diets

An experiment with 236 steers and eight pens per treatment (14 or 15 steers/pen) evaluated two grain adaptation treatments. Treatments included adapting steers by decreasing alfalfa (CON) or decreasing a combination of distillers grains and corn gluten feed (SYNERGY) followed by feeding a common finishing diet to slaughter. Performance and carcass traits did not differ between adaptation systems. A combination of MDGS and SYNERGY can be used to adapt beef cattle to feedlot diets with efficacy of the traditional, foragebased method

The Charging Structure for the Great Barrier Reef - A review of willingness to pay

The Great Barrier Reef Marine Park Authority (GBRMPA or the Reef Authority) is currently conducting a comprehensive review of the charging structure for the use of the Great Barrier Reef (GBR) Marine Park with a view to implement potential changes from 1 July 2023