Integrity tests: Overlooked facts, resolved issues, and remaining questions.

Comments on W. J. Camara and D. L. Schneider's (see record 1994-23870-001) summary of reports on integrity tests (ITs). It is argued that in reviewing empirical findings about the validity of ITs, they overlooked critical findings regarding how well they work and what they measure. Also, their concerns regarding research on ITs conducted by test publishers are unfounded. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The analysis of the current–voltage characteristics of the high barrier Au/Anthracene/n-Si MIS devices at low temperatures

The Au/Anthracene/n-Si/Al MIS device was fabricated on the basis of anthracene film covalently bonded to a Si substrate. The MIS device showed Schottky behavior with barrier heights of 0.85 eV and ideality factors of 1.88 at 300 K. The barrier height of the Au/n-Si has increased after deposition of the anthracene layer onto Si. Temperature dependent current–voltage (I–V) measurements were performed on the Au/Anthracene/n-Si/Al MIS diodes in the range 140–300 K. From the temperature dependence of forward bias I–V, the barrier height was observed to increase with temperature. However, the ideality factor decreased with increasing temperature. The values of activation energy (E_a) and Richardson constant (A*) were determined as 0.24 eV and 7.57 × 10⁻⁶ A cm⁻² K⁻² from the slope and the intercept at ordinate of the linear region of Richardson plot, respectively. The increase of the series resistance R_s with the fall of temperature was attributed to lack of free carrier concentration at low temperatures.     

Characterization and elemental analysis of wood pellets obtained from low-valued types of wood

In this study, we compared the quality of wood pellets obtained from several different raw materials, i.e., Rhododendron ponticum (Type 1), Laurus nobilis (Type 2), and Castanea sativa (Type 3). The quality of the wood pellets was characterized mainly by their bulk density, moisture content, ash content, volatiles, sulfur content in the ash, total sulfur content, heating values, elemental analysis of the ash, and chlorine content. The results showed that bulk density was similar for each type of pellet. In quality values, ash content and the sulfur content in the ash were found to be lower for Type 3 (Chestnut wood pellets) than they were for the other two types. The results also showed that dry samples of Type 1, Type 2, and Type 3 wood pellets had heating values of 5057, 4691, and 4571 kcal/kg, respectively, whereas the original (undried) samples had heating values of 4571, 4409, and 4293 kcal/kg, respectively.     

Environmental optimization of chromium recovery from tannery sludge using a life cycle assessment approach

Life cycle assessment (LCA) was used to evaluate the environmental impact of an oxidative chromium recovery method from tannery sludge, in comparison with the usual landfilling process. Three improvement options (water reduction, byproduct use and anaerobic sludge digestion) were considered. The results showed that the proposed chromium recovery process would be better environmentally than conventional landfilling in all the evaluated impact categories if the amount of chromium recovered was 43 kg per ton of sludge. This amount could be recovered if the chromium concentration was about 20 times higher than that considered in this study. Alternatively, a lower chromium concentration would produce a better result if the recovery method was optimized and implemented at industrial rather than laboratory scale, and if more accurate data were provided on environmental credits for avoiding the chromium production process. Thus, the recovery method is environmentally beneficial when tannery sludge contains a chromium concentration of about 100,000 ppm. According to the literature, such concentrations are not unusual. The results could serve as the basis for further environmental improvements in chromium recovery and tannery sludge management and should be used in decision-making processes, especially for end-of-pipe treatments.     

Effect of harvesting hour on some physical and mechanical properties of Rosa damascena Mill

BACKGROUND: Mechanization of Rosa damascena flower harvest is limited because of the asynchronous flowering period, the necessity for the harvest operation to take place in the early hour of the morning, and a lack of knowledge regarding the physical–mechanical properties of R. damascena. This study investigated the effect of harvesting hour on some physical–mechanical properties of R. damascena. RESULTS: The terminal velocity of the rose flower ranged from 4.00 to 2.38 m s^?1. The highest picking force was found to be 6.29 N for the harvesting hour of 06:00 am. Tear forces of petal changed from 1.54 to 0.97 N for the harvesting hour of 06:00 am and 12:00 pm, respectively. The tension force of pedicel varied between 8.25 and 7.76 N. The weight of the rose flower was measured as an average of 1.61 and 1.50 g at 06:00 am and 12:00 pm, respectively. Horizontal and vertical projection areas of rose flowers were positively correlated with harvesting hour, with an R² of 0.97 and 0.75, respectively. Results showed that there was a minor loss in colour for both inner and outer surfaces of petals. CONCLUSION: The results of physical–mechanical properties of R. damascena obtained from this study should be considered for the operation of flower harvest mechanization. Copyright © 2011 Society of Chemical Industry     

Fabrication and magnetoresistivit of ex-situ processed MgB<Subscript>2</Subscript>/Fe monofilament tapes without any intermediate annealing

We have fabricated MgB₂/Fe monofilament wires and tapes by a powder-in tube (PIT) technique, using an ex-situ process without any intermediate annealing. MgB₂/Fe monofilament tapes were annealed at 650–1,050°C for 60 min and 950°C for 30–240 min. We have investigated the effect of annealing temperatures and times on the formation of MgB₂ phase, activation energy, temperature dependence of irreversibility field H _irr(T) and upper critical field H _c2(T), transition temperature (T _c), lattice parameters (a and c), full width at half maximum, crystallinity, resistivity, residual resistivity ratio, active cross-sectional area fraction and critical current densities. We observed that the activation energies of the MgB₂/Fe monofilament samples increased with increasing annealing temperature up to 950°C and with increasing annealing time up to 60 min while it decreased with increasing magnetic field. For the MgB₂/Fe monofilament tape, the slope of the H _c2–T and H _irr–T curves decreased with increasing annealing temperature from 850 to 950°C as well as with increasing annealing time from 30 to 60 min. The transport and microstructure investigations show that T _c, J _c and microstructure properties are remarkably enhanced with increasing annealing temperature. The highest value of critical current density is obtained for the sample annealed at 950°C for 60 min. The J _c and T _c^offset values of the sample annealed at 950°C for 60 min were found to be 260.43 A/cm² at 20 and 38.1 K, respectively.     

Role of social desirability in personality testing for personnel selection: The red herring.

Response bias continues to be the most frequently cited criticism of personality testing for personnel selection. The authors meta-analyzed the social desirability literature, examining whether social desirability functions as a predictor for a variety of criteria, as a suppressor, or as a mediator. Social desirability scales were found not to predict school success, task performance, counterproductive behaviors, and job performance. Correlations with the Big Five personality dimensions, cognitive ability, and years of education are presented along with empirical evidence that (a) social desirability is not as pervasive a problem as has been anticipated by industrial-organizational psychologists, (b) social desirability is in fact related to real individual differences in emotional stability and conscientiousness, and (c) social desirability does not function as a predictor, as a practically useful suppressor, or as a mediator variable for the criterion of job performance. Removing the effects of social desirability from the Big Five dimensions of personality leaves the criterion-related validity of personality constructs for predicting job performance intact. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Defects in liquid crystals (II)

Defects in the disordered (uniaxial) liquid crystals, nematic, smecticA and cholesteric, and the use of topological analysis in classifying them, are discussed. While the latter is very successful in classifying defects in nematics, it fails to do so in the case of smecticA and cholesteric liquid crystals because of geometrical constraints. However, topological arguments have been partially successful in predicting some of the defects in cholesterics. The known features of the isotropic (cubic and amorphous) cholesteric blue phases are summarised and the various theoretical models picturing them as defect lattices, are also discussed briefly.     

Statistical Modeling of β-galactosidase Inhibition During Lactose Hydrolysis

A statistical model approach called response surface methodology was used to describe the product and substrate inhibition effect on β-galactosidase enzyme during lactose hydrolysis. The effect of independent variables, namely the initial concentrations of lactose (73 - 146 mM), galactose (44 - 122 mM) and glucose (83 - 167 mM) on the reaction rate of β-galactosidase was evaluated. The enzymatic reaction rate was influenced by both combined and individual effects of all the substrate and products. Although, glucose acted as an activator at low lactose and low galactose concentrations, glucose caused the inhibition of β-galactosidase at higher concentrations of lactose and galactose. The effect of galactose concentration on β-galactosidase enzyme was in the direction of inhibition. At low lactose concentrations and high glucose concentrations, galactose concentration became more effective on the reaction rate.