Computation of Wechsler Adult Intelligence Scale—Revised factor scores: Equal and differential weights.

Standard procedures for estimating factor scores for the Wechsler Adult Intelligence Scale—Revised (WAIS—R; D. Wechsler, 1981) involve equally weighted sums of the subtests that load most highly on the factor being estimated. We argue that factor scores derived in this manner lack discriminant validity; they are strongly biased toward g (the first unrotated factor) and away from the other 2 unrotated factors. If regression-like weights are applied to all of the WAIS—R subtests and the products are summed, the resulting differentially weighted factors give results that show similar convergent validity and much greater discriminant validity with respect to the original factors. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The potential for energy efficiency in electric end usetechnologies

The authors summarize a recent study conducted by the Electric Power research Institute (EPRI) that contains estimates of potential energy savings that will result if the most efficient electricity technologies readily available immediately attain complete market saturation in the year 2000. They first define and contrast various efficiency scenarios and then summarize the energy savings forecast associated with demand-side management measured by sector. These estimates have been developed through discussions with a wide range of experts both inside and outside the utility industry, review of the trade and technical literature, and simulations and forecasts using several end-use models. The main results for efficient technologies that reduce electric usage are presented     

The origin of the band at 1462 cm−1 generally appearing upon desorption of pyridine from acidic solids. Steps towards a more comprehensive understanding

The pyridine adsorption-desorption method, followed by IR spectroscopy, is generally applied for acidity determination of solid catalysts. A peculiar band at 1462 cm^–1 was observed by several authors upon pyridine desorption at higher temperatures and was interpreted in various ways. A new complex between Lewis framework acid sites and pyridine is proposed and several evidences are reported.     

Automated derivation of time bounds in uniprocessor concurrentsystems

The successful development of complex real-time systems depends on analysis techniques that can accurately assess the timing properties of those systems. This paper describes a technique for deriving upper and lower bounds on the time that can elapse between two given events in an execution of a concurrent software system running on a single processor under arbitrary scheduling. The technique involves generating linear inequalities expressing conditions that must be satisfied by all executions of such a system and using integer programming methods to find appropriate solutions to the inequalities. The technique does not require construction of the state space of the system and its feasibility has been demonstrated by using an extended version of the constrained expression toolset to analyze the timing properties of some concurrent systems with very large state spaces     

Investigation of the sedimentation of FeNi fine grains entrained in ERF slag

Nickel losses in the slag generated at Larco electric reduction furnaces (ERF) during smelting of Greek laterites account for about 20% of the total nickel of the feed. The recovery of the nickel contained in the slag as well as in its magnetic concentrate was studied under different methods. The experimental results have shown that a nickel recovery in the range of 75-90% is possible by allowing the slag to settle. Washing by low carbon steel can be performed during the final stages of the settling process as it improves the finally attained nickel recovery up to 94.4%. The simultaneous carbon reduction and settling process do not favour the Ni- recovery as the produced carbon monoxide and dioxide cause boiling of the bath which promotes the flotation of the metallic grains. In all cases a reoxidation of nickel was observed after 20min approximately. Settling of the ferronickel grains was described by a mathematical model. The model's results are in good agreement to the experimental ones for the initial 20min of the process. A modified model was elaborated combining the settling of the metallic grains with the nickel reoxidation reaction. This model describes with adequate accuracy the whole Ni- recovery process. The developed model can be proven helpful in the design of a slag cleaning step for metal recovery utilizing a slag settling furnace operating on line to the ERF.     

Loose-part signal properties

Lamb's solution for two-dimensional wave propagation was used to identify plate bending wave characteristics observed in loose part impact signals. The surface displacement wave is shown to have large second derivatives at points that can be used to measure the impact contact time. General features of the initial impact wave shape provide guidance for the use of spectral analysis techniques to identify the contact time and wave arrival time when there is a low signal-to-noise ratio. Improvements in the determination of contact time improve the estimation of loose part mass and energy through the Hertz impact parameters. The shape of the initial impact wave shape can also be used to identify on which side of the plate the impact took place. This information has applications for Loose Part Monitoring System metal impact signal validation and for improved estimation of loose part parameters.     

Laser conization guided by endocervical staining with methylene blue

The authors report their experience of the use of a vital stain--methylene blue--as a surgical guide in laser cervical conization for CIN2-CIN3/CIS. During the period 1 October 1991-31 December 1992 a total of 40 laser cervical conizations were performed under local anesthesia using a CO2 laser connected to a microhandpiece and colposcope in patients with exo-endocervical lesions which were histologically positive for CIN2-CIN3/CIS. In 33/40 patients an aqueous solution of 1% methylene blue was introduced preoperatively in the endocervix using a cotton-wool bud with consequent impregnation of the pseudoglandular crypts: laser biopsy was performed along the guidelines of the stain itself. This enabled the direction of resection to be varied: in 3 patients due to an anomalous and eccentric direction of cervical canal; in 10 patients to remove glandular structures surrounding or underneath lesions; in 8 patients following pseudoglandular section to carry out deep vaporization (3 patients) or correct cutting edges (5 patients). The apex and edges of the cone were always intact. Fourteen patients completed a 12-month follow-up and a further 6 were followed up for 9 months; only 1/14 patients (with AIDS) showed recidivation after 1 year. In the authors' experience the use of a vital stain as a guide during laser cervical cone biopsy is an easily used method which ensures the greatest possible respect for healthy cervical structures, also in order to preserve fertility in young patients.     

Crack tip parameters and elastic-plastic fracture of metals

By using optical displacement-measuring techniques we obtain the crack tip fields in terms of crack tip strain, crack opening angle (COA) and crack tip opening angle (CTOA). Thin plates with different crack configurations made of six elastic-plastic materials with strain hardening exponent ranging from 3 to are studied. We find that the COA resistance curve assumes certain characteristics common to all the materials. The experimental results indicate that the critical value of COA may be used as a fracture toughness parameter for these materials.

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Résumé En utilisant une technique de mesure optique des déplacements, on obtient les champs régnant à l'estrémité d'une entaille, qui s'experiment par la déformation d'extrémité d'entaille, l'angle d'ouverture de la crique (COA et l'angle d'ouverture de la pointe de la crique (CTOA). On étudie des feuillards présentant différentes configurations de fissures et réalisés en six matériaux élasto-plastiques dont les modules d'écrouissage s'échelonnent de 3 à l'infini.On trouve que la courbe de résistance COA suppose certaines caractéristiques communes à tous les matériaux. Les résultats expérimentaux indiquent que la valeur critique du COA peut être utilisée comme paramètre de ténacité à la rupture pour les matériaux étudiés.

     

Development of a new 304L austenitic welding consumable containing tungsten

The transformation behaviour and kinetics of a duplex weld metal, in which tungsten was substituted for molybdenum, have been studied at 600, 700 and 800 C. Despite a low carbon level (0.037wt%), the material exhibited exceptional resistance against intermetallic formation during ageing. The Charpy impact toughness at room temperature was consistently superior compared to a standard molybdenum containing 316 weld metal. The results suggest that suitable development of the tungsten-bearing 304 consumable could lead to significant improvements in weld-metal properties.