• Energy Research
• Closed Access close
• Restricted close
• Embargo close
• US close
• CA close
• RU close
• RS close

Forty-nine schools (N = 5,680 fifth and sixth grade students) were assigned to pre test/treatment, pretest/no treatment, no pretest/treatment, and no pretest/no treat ment conditions in the context of an alcohol misuse prevention study. At the first posttest, five months after the pretest and two months after the intervention, the effects of the pretest and of the intervention were examined. The analyses showed that failure to correct for the design effect due to clustering within schools resulted in the overestimation of the significance of treatment and pretest effects. After correction for the design effect, a significant treatment effect in the hypothesized direction was found with respect to students' awareness of the content of the curriculum. As hypo thesized, significant treatment effects on the alcohol use and misuse measures had not yet developed but are expected to occur at subsequent posttest occasions. Significant pretest effects were found for indices measuring trouble with peers resulting from students' alcohol use, students' internal health locus of control, and their perceptions of adults as a locus of control for their health. Two of the three pretest effects were in the direction that would be hypothesized if the pretest were providing the same impe tus as the intervention. Implications of these findings for school-based substance abuse prevention programs are discussed.

The temperature dependence of the electrical conductivity of the molten eutectic GdCl3(0.515)–KCl(0.485) containing up to 3.3 mol % gadolinium oxide is studied. The temperature dependences of the conductivity of the molten GdCl3–KCl–Gd2O3 system are approximated by second-order polynomials. The formation of gadolinium oxychlorides is confirmed by spectral studies of the solidified melt.

Two approaches to synthesis of unsymmetrical disulfides based on different types of thiol activation, namely, an electrochemical method in the presence of a redox mediator and a microwave irradiation, were discussed. The mediated electrosynthesis procedures were carried out by the oxidative coupling of thiols or by the thiol-disulfide exchange in the presence of redox pairs—substituted o-aminophenol/o-iminobenzoquinone. It has been established that the formation of unsymmetrical disulfides under electrochemical conditions occurs as a result of both the oxidative coupling of sulfur-centered radicals, and a redox-mediator promoted thiol-disulfide exchange, which led to a high yield of heterodimeric products (89%–99%). The microwave-assisted synthesis made it possible to obtain the target products with yields of 13%–86% depending on different irradiation parameters such as power, temperature, and irradiation duration. However, this method requires a rigorous selection of conditions for each reaction and is therefore inferior to the electrochemical approach.

Endocrinological research on wild animals inhabiting remote areas has been hampered by the need to store plasma samples at subzero temperatures. In an attempt to remedy this logistical issue, we here investigate the use of ethanol as an alternative to freezing for the preservation of steroid and indoleamine hormones in avian plasma. Known quantities of the steroids 5alpha-dihydrotestosterone (DHT), testosterone, 17beta-estradiol, corticosterone, and the indoleamine melatonin were added to a stripped pool of chicken plasma. Samples were either immediately frozen at -40 degrees C, or treated with pure ethanol. Ethanol-treated samples were either immediately frozen, or-to simulate storage conditions at various field locations-left sitting at room temperature for one to two months, or incubated at 36 degrees C for one month before all treatment groups were frozen at -40 degrees C. All samples were then analyzed by radioimmunoassay. For DHT and estradiol there were no differences among treatment groups suggesting that ethanol-treatment is as effective as immediate freezing in preserving plasma steroid concentrations. For testosterone, corticosterone and melatonin ethanol-treated samples differed significantly from immediately frozen samples suggesting that caution is needed when comparing absolute concentrations of hormones between samples preserved in different ways. However, differences among ethanol-treated samples in general were small, demonstrating the feasibility of this preservation method in the field at remote locations.

Abstract Gas-insulated systems are now a major component of power transmission and distribution systems all over the world. There has been considerable interest in non-thermal discharges over the past decade due to the increased number of industrial applications. Diverse applications demand a solid physical and chemical understanding of the operational principals of such discharges. This paper focuses on the most important and widely used variety of non-thermal discharges, the corona discharge. Positive corona in SF6 is studied for a point to plane electrode gap using Monte Carlo simulation technique. The initiation and development of successive avalanches are traced as function of time. The simulation provides a detailed structure of avalanches from which essential properties of corona discharge with regard to total field distribution, propagation of successive avalanches and ion distribution can be discerned.

This paper studied the influence of transformer inrush current on commutation failure prevention control of Ultra-high voltage DC (UHVDC) transmission system. An actual event occurred on Tianzhong UHVDC transmission project was analyzed with data from fault recorder. UHVDC transmission model with commutation failure prevention control was established in PSCAD/EMTDC, and then it was applied to replay the event. It is found that the frequent maloperation of commutation failure control and the fluctuation of DC power exist when inrush current occurred. An improved commutation failure prevention control strategy was proposed to avoid this phenomenon. Validity of the improved method was proved by the simulation results.

Abstract Space–time kinetics calculations for CANDU ® 1 reactors are routinely performed using the Improved Quasistatic (IQS) method. The IQS method calculates kinetics parameters such as the effective delayed-neutron fraction and generation time using adjoint weighting. In the current implementation of IQS, the direct flux, as well as the adjoint, is calculated using a two-group cell-homogenized reactor model which is inadequate for capturing the effect of the softer energy spectrum of the delayed neutrons. Additionally, there may also be fine spatial effects that are lost because the intra-cell adjoint shape is ignored. The purpose of this work is to compare the kinetics parameters calculated using the two-group cell-homogenized model with those calculated using lattice-level fine-group heterogeneous adjoint weighting and to assess whether the differences are large enough to justify further work on incorporating lattice-level adjoint weighting into the IQS method. A second goal is to evaluate whether the use of a fine-group cell-homogenized lattice-level adjoint, such as is the current practice for Light Water Reactors (LWRs), is sufficient to capture the lattice effects in question. It is found that, for CANDU lattices, the generation time is almost unaffected by the type of adjoint used to calculate it, but that the effective delayed-neutron fraction is affected by the type of adjoint used. The effective delayed-neutron fraction calculated using the two-group cell-homogenized adjoint is 5.2% higher than the “best” effective delayed-neutron fraction value obtained using the detailed lattice-level fine-group heterogeneous adjoint. The effective delayed-neutron fraction calculated using the fine-group cell-homogenized adjoint is only 1.7% higher than the “best” effective delayed-neutron fraction value but is still not equal to it. This situation is different from that encountered in LWRs where weighting by a fine-group cell-homogenized adjoint is sufficient to calculate the correct effective delayed-neutron fraction. It is concluded that lattice-level weighting with a detailed fine-group heterogeneous adjoint is desirable for the correct calculation of the effective delayed-neutron fraction in CANDU lattices.

AbstractA novel multifunctional conjugated polymer (RCP‐1) composed of an electron‐donating backbone (carbazole) and an electron‐accepting side chain (cyanoacetic acid) connected through conjugated vinylene and terthiophene has been synthesized and tested as a photosensitizer in two major molecule‐based solar cells, namely dye sensitized solar cells (DSSCs) and organic photovoltaic cells (OPVs). Promising initial results on overall power conversion efficiencies of 4.11% and 1.04% are obtained from the basic structure of DSSCs and OPVs based on RCP‐1, respectively. The well‐defined donor (D)‐acceptor (A) structure of RCP‐1 has made it possible, for the first time, to reach over 4% of power conversion efficiency in DSSCs with an organic polymer sensitizer and good operation stability.