Drug overdose: widening the parameters of research and prevention

[A focus on risk environments] helps to overcome the limits of individualism characterising most [drug] prevention interventions as well as to appreciate how drug-related harm intersects with health and vulnerability more generally.<br />

Application of identification techniques to determine effect of carbon content in steels on rheological parameters during hot deformation

The objective of the present work is searching for the correlation between the carbon content in steels and the parameters of the rheological models, which are used to describe the materials behavior during hot plastic deformation. This correlation can be expected in the internal variable models, which are based on physical phenomena occurring in the material. Such a model, based on the dislocation density as the internal variable, is investigated in this work. The experiments including hot torsion tests are used for the analysis.<br />The procedure is composed of three parts. Plastometric tests were performed for steels with various carbon content. Optimization techniques were applied next to determine the coefficients in the internal variable rheological model for these steels. Two versions of the model are considered. One is based on the average dislocation density and the second accounts for the distribution of dislocation densities. Evaluation of correlation between carbon content and such coefficients in the models as activation energy for self diffusion, activation energy for recrystallization, grain boundary mobility, recovery coefficient etc. was the main objective of the work. In consequence, the model which may be used for simulation of hot forming processes for steels with various chemical compositions, is proposed.

Chemical modification of timber decking : assessing the parameters of acceptability

The criteria for accepting or rejecting a technology extend beyond the intrinsic properties of the finished product such as physical performance. There are also extrinsic factors such as the history of the product and trust in the manufacturers and suppliers, as well as the perceptions and risk management strategies of various stakeholder groups. A methodology was trialled to take into account the extended supply chain of the product, while simultaneously engaging stakeholders to determine and to understand their perceptual frameworks. Three pine decking products manufactured using different amounts and types of chemical modification were compared using life cycle assessment and the comments of 114 respondents from six stakeholder groups in New Zealand. The results of the perceptual research include a quadrant diagram which allows a visual comparison of the responses of different stakeholders to actual or hypothetical products, aiding the identification of when and why certain technologies may be disqualified from acceptability or become the topic of public debate.<br />

Optimization of process parameters for the production of naringinase by Aspergillus niger MTCC 1344

<i>Aspergillus niger </i>MTCC 1344 was used to produce extracellular naringinase in a complex (molasses, yeast extract and salts) medium. An initial medium pH 4.5 and cultivation temperature 30 &deg;C were optimal for enzyme production. Among various carbon and organic nitrogen sources used, molasses and peptone were the most effective for enzyme yield. The rate of enzyme production was enhanced when metal ions were added to the medium. Fermentation conditions are described which produced a higher rate of enzyme synthesis. An increase in initial sugar concentration from 6 to 10 g l^&minus;1 in the fermentation medium produced decreased naringinase synthesis while cell mass growth increased with the increase of sugar concentration. At a higher sugar level (10 g l^&minus;1) the production of cell mass decreased.<br />

Optimization of medium and process parameters for the production of inulinase from a newly isolated Kluyveromyces marxianus YS-1

A newly isolated strain of <i>Kluyveromyces marxianus</i> YS-1 was used for the production of extra cellular inulinase in a medium containing inulin, meat extract, CaCl₂and sodium dodecyl sulphate (SDS). Fermentation medium pH 6.5, cultivation temperature 30 &deg;C and 5% (v/v) inoculum of 12 h-old culture were optimal for enzyme production (30.8 IU/ml) with a fermentation time of 72 h at shake flask level. Raw inulin (2%, w/v) extracted from dahlia tubers by processing at 15 kg/cm² for 10 min was optimum for bioreactor studies. Maximum enzyme production (55.4 IU/ml) was obtained at an agitation rate of 200 rpm and aeration of 0.75 vvm in a stirred tank reactor with a fermentation time of 60 h.<br />

Some osmoregulatory parameters in selected fishes of the Australasian region

Fish must maintain their internal ionic concentration. This occurs through co-ordination of cellular ion channels and transporters, and hormones acting on and within the cells of the gill, kidney, intestine, and, in some species, unique organs. This study measured some of these transporters and hormones in unusual species of the Australasian region.

Optimization of mixing parameters through a water model for metal matrix composites synthesis

The influence of the mixing parameters on the synthesis of Al&ndash;SiCp reinforced metal matrix composites (MMCs) by the stir casting technique is investigated through a water model. The effects of some important mixing parameters such as impeller blade angle, rotating speed, direction of impeller rotation and effect of baffles are investigated and optimized. The results have shown that the axial concentration variation of natural graphite during stirring in the presence of four vertical baffles is 1.0 wt% against in the absence of baffles it is increased to 2.3 wt%. The variations observed in natural graphite concentration in water during mixing are in close agreement with the earlier modeling and limited experimental studies reported on the real molten aluminum&ndash;SiC system. Semi-empirical correlations arrived at between the dimensionless numbers for stirred water &ndash; natural graphite slurries are Po = Re&minus;0.0545 Fr&minus;1.099 and Po = Re&minus;0.0219 Fr&minus;1.0382 for clockwise and counter clockwise rotation respectively.<br />

Design and simulation of a RF MEMS shunt switch for Ka and V bands and the impact of varying its geometrical parameters

RF MEMS plays an important role in microwave switching. The high performance of RF MEMS shunt such as high bandwidth, low insertion loss, and high isolation have made these switches well suitable for high performing microwave and millimeter wave circuits. This paper presents a RF MEMS shunt capacitive switch for Ka and V band application. This paper investigates the effect of various geometrical parameters on RF characteristics of the switch. The simulation results are presented and discussed.<br />

Effects of design parameters on sensitivity of microcantilever biosensors

Microcantilever biosensors produce cantilever bending due to differential surface stress between upper and lower surfaces of the cantilever. The bending is associated with concentration of ligands and adsorbed ligand-receptor intermolecular forces. Sample volume sizes in clinical diagnostic applications are usually very minute requiring a highly sensitive microcantilever for disease detection. This paper investigates a number of parameters that influence the sensitivity of microcantilever biosensors. The parameters include length, thickness, shape, and material of the cantilever beam. Biosensors of varying parameters are modeled and simulated. The results show that increasing the length of the cantilever beam enhances its sensitivity. However, increasing the thickness of the cantilever beam reduces its sensitivity. In static analysis, the shape of the cantilever beam does not notably impact upon its sensitivity. Also, using materials with lower Young&rsquo;s modulus improves the sensitivity.<br />

Diffusion layer parameters influencing optimal fuel cell performance

The performance of polymer electrolyte fuel cells (PEFCs) is substantially influenced by the morphology of the gas diffusion layer. Cells utilising sintered gas diffusion layers made with a low pore volume Acetylene Black carbon, at an optimised thickness, showed better performance compared with cells containing Vulcan XC-72R carbon. The cells were optimised using both oxygen and air as oxidants showing that different conditions were required in each case to achieve optimum cell performance. A model, in which the hydrophobicity and porosity of the diffusion layer affect water impregnation and gas diffusion through the gas diffusion layer, is presented to explain the influence of the diffusion layer morphology on cell performance.<br />

Comparison of pQCT parameters between ulna and radius in retired elite gymnasts : the skeletal benefits associated with long-term gymnastics are bone- and site-specific

<b>Objectives:</b> To compare the skeletal benefits associated with gymnastics between ulna and radius. <br /><b>Methods: </b>19 retired artistic gymnasts, aged 18-36 years, were compared to 24 sedentary women. Bone mineral content (BMC), total and cortical bone area (ToA, CoA), trabecular and cortical volumetric density (TrD, CoD) and cortical thickness (CoTh) were measured by pQCT at the 4% and 66% forearm. <br /><b>Results:</b> At the 4% site, BMC and ToA were more than twice greater at the radius than ulna whereas at the 66% site, BMC, ToA, CoA, CoTh and SSIpol were 20 to 51% greater at the ulna than radius in both groups (p&lt;0.0001). At the 4% site, the skeletal benefits in BMC of the retired gymnasts over the non-gymnasts were 1.9 times greater at the radius than ulna (p&lt;0.001), with enlarged bone size at the distal radius only. In contrast, the skeletal benefits at the 66% site were twice greater at the ulna than radius for BMC and CoA (p&lt;0.01).<br /><b>Conclusion:</b> Whereas the skeletal benefits associated with long-term gymnastics were greater at the radius than ulna in the distal forearm, the reverse was found in the proximal forearm, suggesting both bones should be analysed when investigating forearm strength.<br />