Auxetic foam for snowsport safety devices

Skiing and snowboarding are popular snow-sports with inherent risk of injury. There is potential to reduce the prevalence of injuries by improving and implementing snow-sport safety devices with the application of advanced materials. This paper investigates the application of auxetic foam to snow-sport safety devices. Composite pads - consisting of foam covered with a semi-rigid shell - were investigated as a simple model of body armour and a large 70 x 355 x 355 mm auxetic foam sample was fabricated as an example crash barrier. The thermo-mechanical conversion process was applied to convert open-cell polyurethane foam to auxetic foam. The composite pad with auxetic foam absorbed around three times more energy than the conventional equivalent under quasi-static compression with a concentrated load, indicating potential for body armour applications. An adapted thermo-mechanical process - utilising through-thickness rods to control in-plane compression - was applied to fabricate the large sample with relatively consistent properties throughout, indicating further potential for fabrication of a full size auxetic crash barrier. Further work will create full size prototypes of snow-sport safety devices with comparative testing against current products

Evaluation of cadmium, lead, nickel and zinc status in biological samples of smokers and nonsmokers hypertensive patients

The objective of this study was to evaluate the association between trace and toxic elements zinc (Zn), cadmium (Cd), nickel (Ni) and lead (Pb) in biological samples (scalp hair, blood and urine) of smoker and nonsmoker hypertensive patients (n=457), residents of Hyderabad, Pakistan. For the purpose of comparison, the biological samples of age-matched healthy controls were selected as referents. The concentrations of trace and toxic elements were measured by atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference materials and by the conventional wet acid digestion method on the same certified reference materials and real samples. The recovery of all the studied elements was found to be in the range of 97.8–99.3% in certified reference materials. The results of this study showed that the mean values of Cd, Ni and Pb were significantly higher in scalp hair, blood and urine samples of both smoker and nonsmoker patients than in referents (P<0.001), whereas the concentration of Zn was lower in the scalp hair and blood, but higher in the urine samples of hypertensive patients. The deficiency of Zn and the high exposure of toxic metals as a result of tobacco smoking may be synergistic with risk factors associated with hypertension

Nickel content of human palatine tonsils: analysis of small tissue samples by flameless atomic absorption spectrophotometry.

Abstract We describe a method for determining the nickel content of small tissue samples by flameless atomic absorption spectrophotometry in this case biopsy specimens from human palatine tonsils. Contact between tissue samples and metallic objects was avoided, except for the use of biopsy forceps (Type No. 8150.00 Wolf, stainless steel) for collecting samples, to imitate the actual procedure when small biopsy specimens are removed from the nasal mucosal membranes in nickel workers for histopathological and chemical investigations. Nickel contamination from this instrument was insignificant at the precision of the present procedures. The mean concentration of nickel in 15 tonsils was 13.5 +/- 7.0 (SD) microng/100g (wet wt). The mean nickel concentration in eight different samples of the same tonsil was 5.6 +/- 2.7 (SD microng/100 g.</jats:p

Analysis for nickel in plasma and urine by electrothermal atomic absorption spectrometry, with sample preparation by protein precipitation.

Abstract We describe and evaluate a method for determining nickel in plasma and urine by atomic absorption spectrometry. Proteins are precipitated with trichloroacetic acid and sulfuric acid; ammonium pyrrolidinedithlocarbamate is used as the chelating agent for nickel, and methyl isobutyl ketone as extraction solvent. The results were compared with results obtained by the acid-digestion technique for removing proteins and other organic substances. Analyses for both plasma and urine were better by the present procedure. The mean and standard deviation for nickel in plasma from 15 healthy individuals was 2.13 +/- 0.58 microgram/liter by this method. For nickel in urine from 15 healthy men the mean and standard deviation was 4.45 +/- 1.9 microgram/liter. The coefficient of variation for plasma was 11.9%, and for urine 12.2% in 10 analyses of the same plasma and urine with the protein-precipitation procedure, as compared with 26.0 and 38.2%, respectively, by the acid-digestion technique.</jats:p

White Paper: functionality and efficacy of wrist protectors in snowboarding—towards a harmonized international standard

The wrist is the most frequently injured body region among snowboarders. Studies have shown that the risk of sustaining a wrist injury can be reduced by wearing wrist protection. Currently, there are a wide variety of wrist protection products for snowboarding on the market that offer a range of protective features. However, there are no minimum performance standards for snowboarding wrist protectors worldwide. The International Society for Skiing Safety convened a task force to develop a White Paper to evaluate the importance and necessity of a minimum performance for all wrist protectors used in snowboarding. The White Paper outlines the need for a general framework for a harmonized international standard and reviews the existing evidence. Therefore, this White Paper may serve as a common base for future discussions. The broader goal of developing and implementing such a standard is to reduce the incidence and the severity of wrist injuries in snowboarding without increasing the risk of adverse events, such as upper arm or shoulder injury. The European standard for inline skating wrist protectors (EN 14120) can serve as a starting point for efforts related to a standard for snowboard wrist protectors, but certain modifications to the standard would be required. It is hypothesized that implementation of a snowboarding wrist protector standard would result in fewer and less severe wrist injuries in the sport and could translate into more riding days for healthy snowboarders and significant health-care costs savings