Building energy-efficiency standards in a life cycle primary energy perspective

In this study we analyze the life cycle primary energy use of a wood-frame apartment building designed to meet the current Swedish building code, the Swedish building code of 1994 or the passive house standard, and heated with district heat or electric resistance heating. The analysis includes the primary energy use during the production, operation and end-of-life phases. We find that an electric heated building built to the current building code has greater life cycle primary energy use relative to a district heated building, although the standard for electric heating is more stringent. Also, the primary energy use for an electric heated building constructed to meet the passive house standard is substantially higher than for a district heated building built to the Swedish building code of 1994. The primary energy for material production constitutes 5% of the primary energy for production and space heating and ventilation of an electric heated building built to meet the 1994 code. The share of production energy increases as the energy-efficiency standard of the building improves and when efficient energy supply is used, and reaches 30% for a district heated passive house. This study shows the significance of a life cycle primary energy perspective and the choice of heating system in reducing energy use in the built environment.     

A comparison of techniques for preparing fish fillet for ICP-AES multielemental analysis and the microwave digestion of whole fish.

Four catfish fillet homogenate treatments before multielemental metal analysis by simultaneous inductively coupled plasma/atomic emission spectroscopy were compared in triplicate. These treatments were: nitric acid wet-ashing by Parr bomb digestion; nitric acid wet-ashing by microwave digestion; tetramethylammonium hydroxide/nitric acid wet digestion; and dry-ashing. The tetramethylammonium hydroxide/nitric acid method was imprecise (coefficients of variation > 20%). The dry-ashing method was fast and sensitive but had low recoveries of 50% for spiked Pb and Al and was not as precise as the Parr bomb or microwave treatments. The Parr bomb method was the most precise method but was less sensitive than the microwave method which had nearly the same precision. The microwave method was then adapted to homogenates of small whole fish < or = 3 cm in length. The whole fish homogenate required more vigorous digestion conditions, and addition of more acid after the evaporative step because of the presence of less oxidizable and acid-soluble components than fillet. The whole fish homogenate was also more heterogeneous than catfish fillet. A quality assurance protocol to demonstrate homogenate uniformity is essential. The use of a non-specialized microwave oven system allowed precise results for fillet and whole fish homogenates.     

Robotic Assembly of Space Solar-Power Facilities

This paper profiles research relating to the robotic assembly, inspection, and maintenance of space solar-power facilities. Free-flying robots, fixed-base manipulators, and attached mobile manipulators are examined, the technical challenges facing them are outlined, and their roles in the construction process are illuminated. Themes include autonomous materials delivery, warehousing, large-scale payload handling and mating, payload attachment in confined spaces, and inspection. Research has addressed a fraction of the technologies needed to perform reliable autonomous assembly, inspection, and maintenance. Areas in need of further development are examined and potential research is outlined. Current technology cannot fulfill the requirements of orbital construction. The research and development needed can be completed in the near future, and substantive assembly inspection and maintenance can be achieved.     

Socioeconomic determinants of health. The contribution of nutrition to inequalities in health

Social class differences in health are seen at all ages, with lower socioeconomic groups having greater incidence of premature and low birthweight babies, heart disease, stroke, and some cancers in adults. Risk factors including lack of breast feeding, smoking, physical inactivity, obesity, hypertension, and poor diet are clustered in the lower socioeconomic groups. The diet of the lower socioeconomic groups provides cheap energy from foods such as meat products, full cream milk, fats, sugars, preserves, potatoes, and cereals but has little intake of vegetables, fruit, and wholewheat bread. This type of diet is lower in essential nutrients such as calcium, iron, magnesium, folate, and vitamin C than that of the higher socioeconomic groups. New nutritional knowledge on the protective role of antioxidants and other dietary factors suggests that there is scope for enormous health gain if a diet rich in vegetables, fruit, unrefined cereal, fish, and small quantities of quality vegetable oils could be more accessible to poor people.