Solubilisation of nickel from powders at near-neutral pH and the role of oxide layers

Dissolution rates of nickel powder in pH 5 acetate buffers were observed to be an effective indicator of the thickness of the oxide layer on the surface of the nickel particle. Tests on powders pre-cleaned with acid or pre-oxidized in air demonstrated this dependence. The saturation level of nickel in the solution is not greatly affected by the initial state of the powder. Effects of additive solutes are most pronounced during short-term dissolution tests. Among such solutes, reduced sulphur and selenium species, phosphate, fluoride, oxalate, and permanganate cause the largest increases in dissolution rate, while hexacyanoferrate, arsenite, periodate, chromate, vanadate, molybdate, iodate, and tungstate suppress the dissolution.     

On the relationship between recognition speed and accuracy for words rehearsed via rote versus elaborative rehearsal.

Tacit within both lay and cognitive conceptualizations of learning is the notion that those conditions of learning that foster "good" retention do so by increasing both the probability and the speed of access to the relevant information. In 3 experiments, time pressure during recognition is shown to decrease accessibility more for words learned via elaborative rehearsal than for words learned via rote rehearsal, despite the fact that elaborative rehearsal is a more efficacious learning strategy as measured by the probability of access. In Experiment 1, participants learned each word using both types of rehearsal, and the results show that access to the products of elaborative rehearsal is more compromised by time pressure than is access to the products of rote rehearsal. The results of Experiment 2, in which each word was learned via either pure rote or pure elaborative rehearsal, exhibit the same pattern. Experiment 3, in which the authors used the response-signal procedure, provides evidence that this difference in accessibility owes not to differences in the rate of access to the 2 types of traces, but rather to the higher asymptotic level of stored information for words learned via elaborative rehearsal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Effect of Membrane Thickness on a Microvascular Gas Exchange Unit

For reducing anthropogenic CO₂ emissions, carbon capture and sequestration technologies benefit from the creation of new and efficient gas exchange systems. Vascularized systems provide a means of exchanging CO₂ by providing high specific surface areas and patterned, intimate contact between capture fluids and gases. The well‐defined geometrical arrangement of fluid and gas channels, separated by semipermeable membranes, also provides a new platform for augmenting the function of liquid chemical solutions to carbon capture. In particular, the separation distance of the channels, or polymer membrane thickness, is closely related to the absorption rate as gases must permeate through the membrane before reacting with a fluid. Here, a study of the relationship between the membrane thickness in 3D microvascular contactors and absorption rates via a selective etching process is reported. By decreasing the membrane thickness, the mass transport rate of CO₂ in the vascular contactor is increased by up to 160%.     

Out-of-plane stresses arising from grain interactions in textured thin films

Face-centered-cubic thin films often have mixed (1 1 1)/(1 0 0) fiber texture. These orientations can have very different in-plane stiffnesses, leading to the possibility of significant stress inhomogeneities. Previous X-ray studies appeared to confirm this, reporting much higher stresses in (1 1 1)- than (1 0 0)-oriented grains. In those studies, the stress in the film normal direction was assumed to be zero everywhere, but Poisson effects suggest that out-of-plane stresses may be significant. Here, an X-ray data analysis that allows for out-of-plane stresses is presented and applied to X-ray data taken from a Cu film. The in-plane stress is shown to be homogeneous, and significant out-of-plane stresses arise. This analysis is shown to be more accurate and more consistent with the microstructure than previous methods. Consideration of inhomogeneous triaxial stress states is seen to be critical to understanding mechanical behavior of films with mixed fiber texture. Models for yielding and texture development are discussed.     

Schools of "thought."

Challenges J. Wolpe's (see record 1979-12261-001) assertion that cognitive (COG) formulations add little to an adequate understanding and treatment of psychological disorders. Conceptual and empirical issues are addressed. Although COG therapies may not be unequivocally superior to other methods, preliminary data suggest that COG approaches may contribute to the clinical effectiveness of psychological or behavioral treatments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optical and electrical properties of quarternary chalcogenides

Optical and electrical characterizations have been made on four compounds of the type Cu₂ZnA^IVX₄^VI with A^IV = Si, Ge and X^VI = S, Se. These compounds belong to either a tetragonal superstructure of zincblende (stannite) or to an orthorhombic superstructure of wurtzite (wurtz-stannite) where a_or = 2a_w, b_or = a_w/tr3, and c_or = c_w. The electrical and optical properties are found to parallel the size of the group IV or group VI atom present.     

Common and specific dimensions of self-reported anxiety and depression: A replication.

To investigate the generalizability of D. A. Clark, R. A. Steer, and A. T. Beck's (1994) findings about the common and specific dimensions of self-reported anxiety and depression, the authors administered the Beck Depression and Anxiety Inventories to 1,000 outpatients diagnosed with various types of psychiatric disorders. Iterated principal-factor analyses with oblique rotation, followed by a Schmid-Leiman transformation, indicated that the amounts of extracted variance and symptom compositions of the resultant factors were comparable to those found in the previous study. The results from both studies are discussed as supporting the tripartite (L. A. Clark & D. Watson, 1991) and cognitive-specificity (A. T. Beck, 1976, 1987) models of anxiety and depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

MECHANISMS OF GASOLINE DEPOSIT FORMATION IN ENGINE INDUCTION SYSTEMS. CHARACTERIZATION OF PRODUCT REACTION BETWEEN BENZOTHIOPHENE OXIDES AND BENZOTHIOPHENES

In order to understand the nature and mechanisms of deposit formation in Induction System Deposit (ISD), reactions between benzothiophene oxides and benzothiophenes were carried out under reflux conditions, using carbon tetrachloride as solvent. Samples of the reaction mixture were taken at different intervals during two weeks, and identification was made by pyrolisis/ gas chromatography/ mass spectrometry (P/GC/MS). In the first sample taken after 12 hr of testing, the formation of high molecular weight sulfur compounds was observed. These compounds were identified as naphthobenzothiophenes, methyl and dimethyl naphthobenzothiophenes, phenylbenzothiophen and dinaphthobenzothiophenes. Mechanisms of formation are proposed and the new intermediate compound is identified     

Common and specific dimensions of self-reported anxiety and depression: Implications for the cognitive and tripartite models.

The common and specific symptom dimensions of anxiety and depression proposed by the tripartite (L. A. Clark and D. Watson, see record 1991-32000-001) and cognitive (A. T. Beck, 1976; see also PA, Vol 74:33248) models were investigated in 844 psychiatric outpatients and 420 undergraduates. Principal-factor analyses with oblique rotations performed on the 42 items of the Beck Depression Inventory and Beck Anxiety Inventory for both samples revealed that there were 2 correlated factors, Depression and Anxiety. Second-order factor analyses of the interfactor correlation matrices indicated a large general distress or negative affect factor underlying the relationship between the 2 first-order factors. Specific depression and anxiety dimensions were apparent even after controlling for negative affect. The results were consistent with both the tripartite and cognitive models, with the cognitive and motivational symptoms specific to depression and the physiological arousal symptoms unique to anxiety. (PsycINFO Database Record (c) 2010 APA, all rights reserved)