Long-term testing and applications of high-stress MV EPR cables

High-stress design 35-kV ethylene propylene rubber (EPR)-insulated cables with 1.14-mm (45-mil) wall reduction have been in service for more than ten years. In the mid 1990s, an extensive cable testing program was initiated to demonstrate that high-stress designs up to 4 kV/mm (101.6 V/mil) exhibit a significant electrical and mechanical safety margin to operate on typical utility network systems. Investigations were also undertaken to demonstrate the suitability of accessories for high-stress designs. This paper will present the results of six-year, long-term wet electrical testing conducted to demonstrate that with proper design, the aging performance of standard wall and high-stress design cables provide satisfactory results and suitable performance for the intended application. Additionally, utility field experience is presented on 35- and 15-kV cables operating at high stress. The experience for these 15-kV medium-voltage EPR cable designs employ the highest recommended stress for cables of this class, as well as taking into account the complete system performance.     

Influence of regular aerobic exercise on psychological health: A randomized, controlled trial of healthy middle-aged adults.

Evaluated 120 healthy, sedentary, middle-aged adults randomly assigned to either a 6-mo home-based aerobic exercise training program or to an assessment-only control condition. Adherence across the 6-mo period by the exercise group was demonstrated by self-report and heart rate microprocessor methods to exceed 75%. A 14-item Likert rating scale was used to measure a variety of psychological variables. Significant between-groups differences favoring the exercise group were found on scale items closely associated with actual physical changes that occurred with exercise (satisfaction with shape/appearance, perceived fitness). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Utilization of chopped and long alfalfa by dairy heifers

Two physical forms of alfalfa hay, chopped and long, were fed at maintenance and for ad libitum consumption to dairy heifers to determine effects upon digestibility and energy utilization. Ad libitum intake was associated with lower digestibility of dry matter (56 versus 58%), neutral detergent fiber (45 versus 58%), and acid detergent fiber (45 versus 52%). Energy balance was 1.77 Mcal/day at ad libitum versus .08 Mcal/day at maintenance. Dry matter intake was similar for chopped (5.4 kg/day) versus long alfalfa (5.5 kg/day). Digestibilities of dry matter, neutral detergent fiber, acid detergent fiber, and cellulose were 7 to 10 percentage units lower when heifers were fed the chopped alfalfa. Metabolizable energy intake generally reflected digestible energy intake, which was about 2 Mcal/day less for heifers consuming chopped alfalfa. Heat production was similar for the two physical forms. Consequently, heifers consuming chopped alfalfa had lower energy balance. Reducing particle size of the alfalfa resulted in lower dry matter and energy digestibility, presumably because of increased rate of passage. Increased intake to compensate for depressed energy utilization of the chopped alfalfa did not occur; effects upon animal gain could not be assessed.     

Heat extraction efficiency of a concentric glass tubular evacuated collector

The results of detailed measurements and calculations of the properties of Sydney University/Nitto Kohki evacuated collector tubes have been used to develop a formula for the instantaneous heat extraction efficiency η of a collector panel incorporating the evacuated tubes. The instantaneous efficiency depends on ambient temperature, mean fluid temperature in the collector, solar flux and the design of the manifold used to extract heat from the glass absorber tubes. Manifold design determines the mean temperature difference between absorber tube surface and mean fluid temperature for given operating conditions, and strongly affects the efficiency η of a collector panel. Neither changes in the number of evacuated tubes per unit area of collector, nor variations in solar flux, significantly alter the efficiency decrement Δ η₀ associated with a particular manifold design. Calculated efficiencies agree well with experimental results for collector panels incorporating manifolds of various designs. The formula for efficiency η allows detailed analysis of the relative importance of various energy loss mechanisms in a collector.     

SOLUBILISATION OF NITROGENOUS CONSTITUENTS OF BREWERS' SPENT GRAIN

The extraction of nitrogenous material from Brewers' spent grain (BSG) by solvents (water, sodium chloride solution, aqueous alcohol, acidic and alkaline solutions) commonly used to extract cereal proteins, resulted in the relatively low (0·2 to 8·5%) recovery of the total nitrogen. The recovery of nitrogenous material by the use of aqueous alkaline solutions was increased from 3–4% to 41% when the BSG was subjected to cellulase incubation prior to extraction. Approximately 75% of the nitrogen was solubilized with trifluoracetic acid. Detergent solutions (acid, neutral) solubilized more than 80% of the total nitrogen of the BSG. The low solubility of the nitrogenous constituents by conventional protein solvents could be the result of association between cellulosic material and protein.