Unacceptable Levels (unacceptable + level)

Distribution by Scientific Domains

Selected Abstracts

New data for sandwich panels on the correlation between the SBI test method and the room corner reference scenario

Jesper Axelsson
Abstract Assessment of the fire behaviour of sandwich panels is continuously under discussion. The fire behaviour of these panels is a combination of material characteristics such as the core material and mechanical behaviour of the panels such as joints, dilations etc. The use of small or intermediate scale tests can be questioned for such types of products. Within the proposed European product standard for sandwich panels (prEN 14509) the intermediate scale test method SBI (EN 13823) has been suggested as the fire test method to certify panels. The standard does, however, use quite an artificial mounting procedure, which does not fully reflect the end-use conditions of the panels. In a previous research project conducted by Nordtest it was shown that the correlation between the SBI test method and both the ISO 9705 and ISO 13784 part 1 was insufficient. The test data produced for the SBI test method, however, did not use the above mentioned mounting technique. In this article new data for a number of products are added to the database using the mounting procedure of the product standard. The data are compared with the previous data and show that the mounting method of the product standard results in slightly more severe conditions but that there are still discrepancies with the full-scale test results. The data also show an unacceptable level of repeatability due to the fact that small dilations result in a wide variation of classification result. The new data together with the old data show once more that it is dangerous to make a fire safety assessment of a sandwich panel based on small or intermediate scale tests. Copyright 2004 John Wiley & Sons, Ltd. [source]

Analgesic effect of dextromethorphan in neuropathic pain

K. C. Carlsson
Background: Dextromethorphan, a clinically available N-methyl-D-aspartic acid (NMDA) receptor antagonist, has an analgesic effect in patients with diabetic neuropathy. The aim of this study was to evaluate the analgesic and adverse effects of a single high dose of dextromethorphan on spontaneous pain in patients suffering long-term neuropathic pain of traumatic origin. Methods: Fifteen patients with post-traumatic neuropathic pain participated in this placebo-controlled, double-blind, randomized crossover study. On two separate occasions, the participants received 270 mg of dextromethorphan hydrobromide or placebo. Pain intensity, adverse effects and serum concentrations of dextromethorphan and metabolites were registered. Results: Dextromethorphan had a statistically significant analgesic effect compared with placebo, but the effect varied markedly among the patients. Light-headedness was the most important adverse effect reported. Extensive metabolizers of dextromethorphan had an apparently better analgesic effect than poor metabolizers. Conclusion: This report indicates that a single high dose of dextromethorphan has an analgesic effect in patients with neuropathic pain of traumatic origin. The main metabolite dextrorphan seems to be important for the analgesic effect. At the relatively high dose studied, the clinical usefulness of dextromethorphan is limited to that portion of the patient population experiencing analgesia without an unacceptable level of adverse effects. [source]

Cricket: notching up runs for food and alcohol companies?

Jill Sherriff
Abstract Objective: To analyse sports sponsorship by food and alcohol companies by quantifying the proportion of time that the main sponsor's logo was seen during each of three cricket telecasts, the extent of paid advertising during the telecast and the contribution by the main sponsor to this, and to describe the associated ground advertising. Methods: DVD recordings of the three telecasts were analysed for visibility of the main sponsor's logo during actual playing time and for each sponsor's proportion of the advertising time during breaks in telecast. Results: The main sponsor's logo was visible on a range of equipment and clothing that resulted in it being clearly identifiable from 44% to 74% of the game time. The proportion of paid advertising time in these three telecasts varied from 3% to 20%, reflecting the difference in advertising content of paid television versus free-to-air. Implications: While television food advertising to children is under review, sporting telecasts also reach children and, until recently, have avoided scrutiny. This content analysis of three recent cricket telecasts reveals an unacceptable level of exposure to food and alcohol marketing, particularly in the form of the main sponsor's logo. Sponsorship is not covered by the voluntary codes of practice that address some forms of advertising. A new system of regulation is required to reduce this unacceptable level of exposure. [source]

Balancing treatment allocations by clinician or center in randomized trials allows unacceptable levels of treatment prediction

Robert K Hills
Abstract Objective Randomized controlled trials are the standard method for comparing treatments because they avoid the selection bias that might arise if clinicians were free to choose which treatment a patient would receive. In practice, allocation of treatments in randomized controlled trials is often not wholly random with various ,pseudo-randomization' methods, such as minimization or balanced blocks, used to ensure good balance between treatments within potentially important prognostic or predictive subgroups. These methods avoid selection bias so long as full concealment of the next treatment allocation is maintained. There is concern, however, that pseudo-random methods may allow clinicians to predict future treatment allocations from previous allocation history, particularly if allocations are balanced by clinician or center. We investigate here to what extent treatment prediction is possible. Methods Using computer simulations of minimization and balanced block randomizations, the success rates of various prediction strategies were investigated for varying numbers of stratification variables, including the patient's clinician. Results Prediction rates for minimization and balanced block randomization typically exceed 60% when clinician is included as a stratification variable and, under certain circumstances, can exceed 80%. Increasing the number of clinicians and other stratification variables did not greatly reduce the prediction rates. Without clinician as a stratification variable, prediction rates are poor unless few clinicians participate. Conclusion Prediction rates are unacceptably high when allocations are balanced by clinician or by center. This could easily lead to selection bias that might suggest spurious, or mask real, treatment effects. Unless treatment is blinded, randomization should not be balanced by clinician (or by center), and clinician,center effects should be allowed for instead by retrospectively stratified analyses. [source]

Development of portable CdZnTe spectrometers for remote sensing of signatures from nuclear materials

Arnold Burger
Abstract Room temperature cadmium zinc telluride (CZT) gamma-ray spectrometers are being developed for a number for years for medical, space and national security applications where high sensitivity, low operating power and compactness are indispensable. The technology has matured now to the point where large volume (several cubic centimeters) and high energy resolution (approximately 1% at 660 eV) of gamma photons, are becoming available for their incorporation into portable systems for remote sensing of signatures from nuclear materials. The straightforward approach of utilizing a planar CZT device has been excluded due to the incomplete collection arising from the trapping of holes and causing broadening of spectral lines at energies above 80 keV, to unacceptable levels of performance. Solutions are being pursued by developing devices aimed at processing the signal produced primarily by electrons and practically insensitive to the contribution of holes, and recent progress has been made in the areas of material growth as well as electrode and electronics design. Present materials challenges are in the growth of CZT boules from which large, oriented single crystal pieces can be cut to fabricate such sizable detectors. Since virtually all the detector grade CZT boules consist of several grains, the cost of a large, single crystal section is still high. Co-planar detectors, capacitive Frisch-grid detectors and devices taking advantage of the small pixel effect, are configurations with a range of requirements in crystallinity and defect content and involve variable degrees of complexity in the fabrication, surface passivation and signal processing. These devices have been demonstrated by several research groups and will be discussed in terms of their sensitivity and availability. ( 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Impact of rootstock on yield and ion concentrations in petioles, juice and wine of Shiraz and Chardonnay in different viticultural environments with different irrigation water salinity

Abstract Background and Aims: Within-site comparisons were made of rootstock effects on yield, and chloride and sodium concentrations in petioles, juice and wine of Shiraz and Chardonnay vines at sites with irrigation water salinities (ECiw) ranging from low (0.4 dS/m) to moderate-high (1.8 to 3.3 dS/m). It also compared consistency of yield performance of the various rootstocks with both scions over 8 years at one site with an ECiw of 2.1 dS/m. Methods and Results: Chardonnay and Shiraz on own roots and on Ramsey, 1103 Paulsen, 140 Ruggeri, K51-40, Schwarzmann, 101-14, Rupestris St. George and 1202 Couderc were compared. Ramsey resulted in better yields relative to most of the other rootstocks at three of the four sites for each scion. Exceptions were the low salinity site where Schwarzmann was best with Chardonnay, and Padthaway where 140 Ruggeri was best with Shiraz. Chardonnay wine chloride concentrations were similar to grape juice chloride concentrations, but Shiraz wine chloride concentrations were on average 1.7-fold higher than grape juice chloride. Conclusions: Shiraz on own roots, K51-40 and 1202C rootstocks carry some risk of accumulating unacceptable levels of chloride in grape juice and wine when the salinity of the irrigation water is at moderate to high levels. Rootstocks K51-40 (with Chardonnay and Shiraz) and potentially 101-14 (with Shiraz) should be avoided in situations of long term irrigation with moderate to high salinity water. Significance of the Study: The study identifies rootstocks with acceptable yields and grape juice chloride concentrations for potential use in regions affected by salinity. [source]

An evaluation of biological and abiotic controls for grapevine powdery mildew.


Abstract Grapevine powdery mildew (Erysiphe necator) affects grape yield and fruit quality worldwide. Managers of conventional vineyards rely mainly on synthetic fungicides and sulfur to control powdery mildew, while in organic vineyards sulfur is the main control agent, often in rotation with canola-based oils, bicarbonates and biological control agents. The efficacy of those materials has not been evaluated critically under field conditions in Australia. Accordingly, a range of materials showing most promise in previous greenhouse trials (Crisp et al. 2006 Australian Journal of Grape and Wine Research12, pp. 192,202) were assessed via field trials in commercial vineyards. Applications of either milk or whey (alone, or mixed with a canola oil-based product), as well as applications of potassium bicarbonate (commercial formulation), all reduced the severity of powdery mildew compared with untreated vines. Eight applications of a 1:10 dilution of milk, 45 g/L whey powder or programs comprising rotations of potassium bicarbonate plus oil and whey, applied at 10,14 day intervals, reduced the severity of powdery mildew to levels not significantly different from that on vines sprayed with sulfur (wettable powder, 3,6 g/L). However, the relative control of powdery mildew by the test materials in field trials was dependent on the susceptibility of the grapevine cultivar and the extent of spray coverage achieved. In vineyards where highly susceptible cultivars were planted, and spray coverage was compromised, the resultant control of powdery mildew was reduced; and sometimes to commercially unacceptable levels. [source]