Electric utility rate structures and distributed thermal energy storage: A cost-benefit analysis

We examine three alternative methods by which electric utilities might take advantage of distributed thermal energy storage to smooth out their load profiles. These three methods are: (1) time-specific rates, (2) time-invariant rates with subsidized storage, and (3) direct load controls with no subsidies to storage. The optimal form of each of these policies is determined and relations indicating the relative desirability of each are developed.     

Computer simulation of structure and properties of crosslinked polymers: application to epoxy resins

In this work, a methodology has been developed for construction of atomistic models of crosslinked polymer networks. The methodology has been applied to low molecular weight water soluble epoxy resins crosslinked with different curing agents that are being considered for use as a primer coating on steel. The simulations allowed the crosslink density and the amount of free crosslinking sites in the coatings to be predicted. Shrinkage of the resin upon curing was reproduced by the simulation. In addition, the barrier properties of the model coatings were estimated. The interface between an inorganic substrate and cured epoxy resin has been constructed and the strength and molecular mechanisms of adhesion have been revealed. The developed methodology has a potential to significantly impact on the design and development of new coatings with improved barrier and adhesion properties.     

A large solid-angle array for heavy ions from APEX

A large solid-angle array of Low Pressure Multi-Wire Proportional Counters (LPMWPCs) has been constructed as part of the ATLAS Positron Experiment (APEX). Eight three-element trapezoidal counters span 360° in φ and 20–68° in laboratory θ. Angle sensitivity in θ is provided by a transmission-line delay cathode, while the 24-fold segmentation provides angle sensitivity in φ. Details are given on the design of the counters and associated hardware. Performance of the counters is described, based on tests with scattered heavy ions ranging from ⁵⁸Ni to ²³⁸U.     

An assessment of the reliability of in-service gappedsilicon-carbide distribution surge arresters

Although gapped silicon carbide arresters are no longer purchased by electricity authorities, they still form the majority of the very large number of distribution arresters in service in Australia and many other countries. Most of the arresters of this type are now over ten years old and many are much older. So the question must be asked-what is to be done with this ageing and outdated class of arresters? Extensive Australian studies in the 1960s had revealed that internal degradation resulting from inadequate seals was the predominant cause of failure of gapped silicon carbide arresters. This paper describes the results of a recent investigation. Electrical testing showed that after about 10 years of service, there is a marked upturn in the number of arresters with unsatisfactory insulation resistance, and after about 13 years of service, a marked upturn in the number of arresters with reduced power frequency sparkover level. Inspection of the internal components of dismantled arresters confirmed that the likelihood of significant degradation increased markedly with years of service, and was evident in almost 75% of arresters with 13 years or more of service. The authors therefore recommend that all gapped silicon carbide arresters with 13 or more years of service be progressively replaced by modern metal oxide arresters     

World collection rice varieties: Resistance to seed penetration by Sitotroga cerealella (Olivier) (Lepidoptera,Gelechiidae)

Lots of 200 eggs of Sitotroga cerealella (Olivier) were placed on 10 g samples of 780 varieties of rice from the U.S.D.A. World Collection. An average of 91% of the eggs hatched and between 1 and 83% of the larvae from these reached the adult stage and emerged. Less than 10% survived in 102 varieties. Graphic data exhibit a bimodal shape, indicating that two resistance bases operated against these insects; both apparently acted to prevent kernel entry by the freshly hatched larvae.     

Reflex-inhibiting stimuli and the refractory period of the acoustic startle reflex in the rat.

Previous studies show that if acoustic startle stimuli are presented in pairs, then the reaction to the 2nd stimulus (S2) is reduced, with the size of the refractory decrement determined by the interstimulus interval and the relative intensity of the 1st stimulus (S1). If a neutral stimulus (p) is presented just prior to S1, then the reaction to S1 is similarly inhibited, revealing the phenomenon of prestimulus inhibition. In 2 experiments with male albino Holtzman rats (N = 24) it was found that suppression of the reflex to S2 by S1 was unaffected by prestimulus inhibition of S1 (i.e., reflex amplitudes associated with S2 were identical in pS1-S2 series and S1-S2 series). In contrast, a reduction in the intensity of S1 relative to S2 did reduce the effect of S1 on S2. These data indicate that prestimulus inhibition of the reflex to S1 does not result because the preliminary stimulus attenuates the sensory impact of S1. The inhibitory process may be presumed to have a central locus. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

MEASUREMENT OF ENAMEL-SLIP CONSISTENCY BY MEANS OF THE BROOKFIELD VISCOSIMETER*

An instrument commonly employed to measure the viscosity of truly viscous liquids was tested to determine its applicability for evaluating consistencies of enamel slips which are solid suspensions in a water medium. Within wide limits of specific gravity differences and variations in set resulting from electrolyte additions, the Brookfield vis-cosimeter afforded comparable information with the pick-up and slump tests employed as references.     

Online fruit weighing using a 500 MHz waveguide cavity

A system for measuring the weight of apples and oranges moving along a conveyor belt is described. The system relies on the effect of the moisture in the fruit on the resonant frequency and the Q-factor of a resonant waveguide cavity