Microstructure-property relationships in Al-Cu-Li-Ag-Mg Weldalite (tm) alloys, part 2

The microstructure and mechanical properties of the ultrahigh strength Al-Cu-Li-Ag-Mg alloy, Weldalite (tm) 049, were studied. Specifically, the microstructural features along with tensile strength, weldability, Young's modulus and fracture toughness were studied for Weldalite (tm) 049 type alloys with Li contents ranging from 1.3 to 1.9 wt. pct. The tensile properties of Weldalite 049 and Weldalite 049 reinforced with TiB2 particles fabricated using the XD (tm) process were also evaluated at cryogenic, room, and elevated temperatures. In addition, an experimental alloy, similar in composition to Weldalite 049 but without the Ag+Mg, was fabricated. The microstructure of this alloy was compared with that of Weldalite 049 in the T6 condition to assess the effect of Ag+Mg on nucleation of strengthening phases in the absence of cold work

Screening for health risks: A social science perspective

Health screening promises to reduce risks to individuals via probabilistic sifting of populations for medical conditions. The categorisation and selection of 'conditions' such as cardiovascular events, dementia and depression for screening itself requires prior interpretive labour which usually remains unexamined. Screening systems can take diverse organisational forms and varying relationships to health status, as when purported disease precursors, for example 'pre-cancerous' polyps, or supposed risk factors, such as high cholesterol themselves, become targets for screening. Screening at best yields small, although not necessarily unworthwhile, net population health gains. It also creates new risks, leaving some individuals worse-off than if they had been left alone. The difficulties associated with attempting to measure small net gains through randomised controlled trials are sometimes underestimated. Despite endemic doubts about its clinical utility, bibliometric analysis of published papers shows that responses to health risks are coming to be increasingly thought about in terms of screening. This shift is superimposed on a strengthening tendency to view health through the lens of risk. It merits further scrutiny as a societal phenomenon

Use of Standardized Assessments and Online Resources in Stroke Rehabilitation

Background: The extent to which movement-related standardized assessments and online resources are used in stroke rehabilitation is unclear in the United States. Method: The researchers used a cross-sectional descriptive survey that examined (a) therapists use of movement-related standardized assessments, (b) factors influencing learning of new assessments, and (c) use of frequency of online resources by occupational therapists and physical therapists in the United States. Results: Of 151 respondents (46.4% occupational therapists, 53.6% physical therapists), the most frequently used movement-related assessments by occupational and physical therapists were the Berg and Fugl-Meyer Assessment, respectively. More physical therapists use motor-related standardized assessments regularly than occupational therapists, and physical therapists showed more consensus among standardized assessments. Both professions cited quality of patient care for motivating them to integrate outcome measures into practice. Most therapists in stroke rehabilitation used online resources to access movement-related standardized assessment content at least 25% of the time. The Rehabilitation Measures Database was the most frequently used website. Conclusion: Both occupational and physical therapists use online resources for movement-related standardized assessments on a regular basis. However, occupational therapists do not use standardized assessments as frequently as physical therapists. A systematic study of factors that impact the integration of standardized assessments is needed to further identify barriers and inform clinical practice change

Modification of the simple mass balance equation for calculation of critical loads of acidity.

Over the last few years, the simple mass balance equation for the calculation of critical loads of acidity has been gradually modified as the underlying critical load concepts have developed and as problems with particular forms of the equation have been identified, through application in particular countries. The first major update of the equation took place following a workshop held in Vienna, Austria (Hojesky et al. 1993). The workshop was held to discuss problems which had been identified when the then current form of the equation was applied in countries with high rainfall. The problems had largely arisen because of simplifications and assumptions incorporated into the early formulation of the equation. The equation was reformulated to overcome the problems identified at the workshop. However, further problems were identified when the reformulated equation was applied in the UK in situations with a combination of high rainfall, large marine inputs and widespread occurrence of organic soils. A small workshop was, therefore held in Grange-over-Sands, UK in late 1993 to dicuss the problems and to further re-evaluate the equation. The problems had arisen in the UK because of simplifications and assumptions made in the formulation concerning, in particular, cation leaching and uptake. As a result, a more rigorous treatment of these variables was incorporated into the equation. The reformulation of the equation, as derived at the September 1993 workshop is described below

InSb charge coupled infrared imaging device: The 20 element linear imager

The design and fabrication of the 8585 InSb charge coupled infrared imaging device (CCIRID) chip are reported. The InSb material characteristics are described along with mask and process modifications. Test results for the 2- and 20-element CCIRID's are discussed, including gate oxide characteristics, charge transfer efficiency, optical mode of operation, and development of the surface potential diagram

\u3ci\u3eHaplosporidium nelsoni\u3c/i\u3e (MSX) Epizootic in the Piscataqua River Estuary (Maine/New Hampshire, U.S.A.)

A major epizootic of Haplosporidium nelsoni occurred during 1995 in the Piscataqua River Estuary, near the northern distributional limit of the parasite. Prevalence of H. nelsoni in samples of oysters, Crassostrea virginica, collected between 5 September and 18 December 1995 from sites in Maine and New Hampshire ranged from 15 to 81 %, with up to 50% systemic infections. Associated proportions of dead oysters ranged from 25 to 83%. The epizootic was most likely triggered by unusually warm and dry climatic conditions in 1995 that resulted in a temperature and salinity regime in the estuary that favored the parasite

Resistance training: here's why it's so effective for weight loss. [Blog post]

Weight lifting, also known as resistance training, has been practised for centuries as a way of building muscular strength. Research shows that resistance training, whether done via body weight, resistance bands or machines, dumbbells or free weights, not only helps us build strength, but also improves muscle size and can help counteract age-related muscle loss. More recently it's become popular among those looking to lose weight. While exercises such as running and cycling are indeed effective for reducing body fat, these activities can simultaneously decrease muscle size, leading to weaker muscles and greater perceived weight loss, as muscle is more dense than fat. But unlike endurance exercises, evidence shows resistance training not only has beneficial effects on reducing body fat, it also increases muscle size and strength

Supersets save time in the gym: which may help you reach fitness goals faster. [Blog post]

Resistance training is an increasingly popular way to build strength, lose weight and get in shape. But despite its many benefits, it can also be time consuming – which is why many fitness enthusiasts have started incorporating "supersets" into gym routines. When done properly, supersets have the potential to help you build strength and muscle – all while spending less time in the gym. Sometimes called paired sets, supersets are a form of strength training in which you perform a set of repetitions of usually two exercises, back-to-back with minimal or no rest between them. The exercises should also target opposing muscle groups – namely the agonists (the force-generating muscles) and the antagonists (the muscle that relaxes when the agonist contracts). For example, leg curls (where the hamstrings are the agonists and the quadriceps the antagonists) would typically be followed by leg extensions (where the quadriceps are the agonists and the hamstrings the antagonists) to make up a superset. However, many people perform supersets incorrectly. Many believe supersets to be the same as compound sets, in which two exercises engaging the same muscle group are performed back-to-back. Or they get confused with contrast training, in which two similar exercises are paired to increase power, the first performed with a heavier load, while the second is performed explosively with a lighter load – such as heavy squats followed by vertical jumps. Many also think supersets comprise upper and lower body exercises performed in succession