Static strength analysis of CANDU-6 reactor fuel bundle

A static analysis, finite-element (FE) model was developed to simulate out-reactor fuel–string strength tests with use of the well-known, structural analysis computer code ABAQUS. The FE model takes into account the deflection of fuel elements, and stress and displacement in endplates subjected to hydraulic drag loads. It was adapted to the strength tests performed for CANFLEX 43-element bundles and the existing 37-element bundles. The FE model was found to be in good agreement with experiment results. With use of the FE model, the static behavior of the fuel bundle string, such as load transfer between ring elements, endplate rib effects, hydraulic drag load incurring plastic deformation in fuel string and hydraulic flow rate effects were investigated.     

Electrospun three‐dimensional silk fibroin nanofibrous scaffold

Practical application to three‐dimensional (3‐D) tissue culture has been limited by the structural restriction of two‐dimensional (2‐D) nature of electrospun nanofiber mat. In this study, for constructing 3‐D nanofibrous structure as real 3‐D tissue engineering scaffold, we developed new fabrication process with silk fibroin (SF) by electrospinning and evaluated the features of this SF nanofiber scaffold (SFNS) through morphological and cell‐culture analyses. Foam type of the SFNS exhibited high porosity as well as large pores and its cell proliferation well occurred inside (inner spaces of pores), which makes this suitable for 3‐D cell‐culture scaffold. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Assessment of world aerosol research trends by bibliometric analysis

This study was to explore a bibliometric approach to quantitatively assessing current research trends on atmospheric aerosol, using the related literature in the Science Citation Index (SCI) database from 1991 to 2006. Articles were concentrated on the analysis by scientific output, research performances by individuals, institutes and countries, and trends by the frequency of keywords used. Over the years, there had been a notably growth trend in research outputs, along with more participation and collaboration of institutes and countries. Research collaborative papers shifted from national inter-institutional to international collaboration. The decreasing share of world total and independent articles by the seven major industrialized countries (G7) was examined. Aerosol research in environmental and chemical related fields other than in medical fields was the mainstream of current years. Finally, author keywords, words in title and keywords plus were analyzed contrastively, with research trends and recent hotspots provided.     

Do adolescent symptomatology and family environment vary over time with fluctuations in paternal alcohol impairment?

This study tested whether adolescent internalizing problems, externalizing problems, heavy alcohol use, fathers' parenting, and family conflict varied over time with fluctuations in fathers' alcohol impairment and also whether children of recovered alcoholic fathers differed from children of nonalcoholic fathers. Fathers and adolescent children (N?=?267 families) were interviewed in 3 annual assessments. Results showed that adolescent symptomatology and the family environment did not vary over time as a function of different trajectories of paternal alcohol impairment. However, children of recovered alcoholic fathers exhibited more symptomatology than did children of nonalcoholic fathers. Even though paternal alcoholism has remitted in these families, children of recovered alcoholic fathers might remain on a general higher risk trajectory relative to children of nonalcoholic fathers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Characterization of electrosynthesized iron diselenide thin films

Iron diselenide (FeSe₂) is an interesting p-type semiconductor with a band gap of 1 eV suitable for solar cell applications. Deposition of FeSe₂ thin films by electrodeposition from aqueous solutions is a low temperature and inexpensive technique. In the present work, FeSe₂ thin films were deposited onto tin oxide coated conducting glass substrates by cathodic electrodeposition technique. The deposited films were characterized by X-ray diffraction, Energy dispersive X-ray analysis, Scanning electron microscope and optical absorption techniques. The effects of electrolyte concentration and deposition potential on the structural, compositional, morphological and optical properties of FeSe₂ thin films are studied. The experimental observations are discussed in detail.     

Impact fatigue of a polycarbonate/acrylonitrile-butadiene-styrene blend

This study analyzes the impact properties of a polycarbonate/acrylanitrile-butadiene-styrene (PC/ABS) blend. The specimens were prepared under various injection molding conditions, including filling time, melting temperature, and mold temperature. Impact tests were performed with a Dynatup drop weight impact tester at different impact energies (10, 15, 20, 25 J). The fracture mechanism was examined with a scanning electron microscopy. The results indicated that the load-time history of the PC/ABS blend has approximately a sinusoidal form in impact. The best injection molding conditions are a filling time of 12 s, a melting temperature of 260°C and a mold temperature of 80°C. In this case, the specimen shows the highest energy absorbed in single impact, together with the highest impact number in impact fatigue. The impact number and the accumulation energy seem to follow an exponential curve as the impact energy decreases. The PC/ABS blend material clearly exhibited ductile fracture with a continuous reduction in strength by viscoplastic deformation. The higher the impact number, the higher the accumulation energy. The accumulation energy of impact fatigue with impact energy 10 J is about 35–45 times greater than the energy absorbed in single impact. Tearing, shear fracture, and plastic deformation are the major fracture mechanisms of the PC/ABS blend matrix in single impact and repeated impact conditions.     

Effect of Acceptors on the Segregation of Donors in Niobium-Doped Barium Titanate Positive Temperature Coefficient Resistors

Small amounts of niobium (donor) doping in barium titanate (BaTiO₃) cause semiconductivity in this material. When the amount of niobium is increased slightly, the BaTiO₃ is converted back to an insulator. This phenomenon is attributed to donor segregation. Such an insulating material can recover its semiconductivity when specific amounts of acceptors are introduced. The space-charge segregation theory explains that such acceptors can prevent the segregation of donors. Impedance/modulus analysis of BaTiO₃ with a slightly increased niobium content and with no or a minimal amount of magnesium (acceptor) show a response of a third resistance–capacitance (RC) network, in addition to the two that have been thought to be caused by the grains and grain boundaries. The response of the third RC network is not observed at greater magnesium concentrations that give a recovery of the semiconductivity. This study suggests that acceptors can inhibit the donor segregation.     

Effects of particle size of Al(OH)3 on electrical properties of EPDM compounds

Effects of particle size of Al(OH)₃ (ATH) filler on electrical properties of ethylene propylene diene terpolymer (EPDM)/ATH compounds were studied. It was found that tracking and erosion resistance of EPDM/ATH compounds decreased while dielectric properties and 90°C water resistance were improved with the increase of particle size. Homocharge accumulates in the compounds, which increases first and then decreases with the increase of particle size. This was explained by the change of particle‐to‐particle distance due to filler size.     

A novel integrated microfluidic platform to perform fluorescence in situ hybridization for chromosomal analysis

The fluorescence in situ hybridization (FISH) technique has been commonly employed to detect the chromosomal abnormalities. However, applications of this technique are limited due to its lengthy process and labor-intensive sample preparation. In this study, a novel integrated microfluidic chip capable of performing the entire FISH protocol automatically was reported. This novel technique can achieve several advantages, including reduce the consumption of bio-samples and reagents, automation and rapid analysis compared to the conventional method. In this study, several functional microfluidic devices were integrated on a single chip to perform automatic FISH on the microfluidic platform. Experimental data demonstrated that the developed microfluidic system successfully provided superior performance for probing the chromosomal abnormality of cells. Furthermore, the novel microfluidic system performed the entire process automatically within 3 h, where the conventional method required 10 h to perform the entire protocol manually. This data indicated superior performance of the novel method. Our findings conclude that the novel integrated FISH protocol is more convenient to perform large quantities of samples, which can be used in clinical trials.