EXTRACTION SYSTEMS USING BIS-1,2-0ICARBCILYLC0BALTATE ANO POLYOXONIUM COMPOUNDS FOR LANTHANIOE SEPARATIONS

ABSTRACT

The extraction of rare earths (lanthanides, Y, Sc) by voluminous bis-1,2-dicarbollylcobaltate anions disolved in nitrobenzene and in a nitrobenzene - carbon tetrachloride mixture has been investigated and the exchange extraction constants for both solvents, individual extraction constants anddG for ion transfer across the water - nitrobenzene phase boundary has been determined. Extraction decreases with increasing atomic number of the lanthanide.

The influence of several polyoxonium compounds on the distribution ratios and the extraction selectivity has been investigated. In the extraction systems with bis-1,2-dicarbollylcobaltate - 18-crown-6 in nitrobenzene, synergism was found for the light lanthanides but antagonism was observed for the heavy ones. The overall separation factor is Ctla/10 compared to in the absence of crown la/²     

Alert eyes and DWIs: An indirect evaluation of a DWI witness reward program in Stockton, CA

We evaluate a “grassroots” anonymous reward program targeting drunken driving in Stockton, CA. The time-series cross-sectional data covers 19 years for Stockton and six other California cities. Exploiting interrupted time-series regression, Zellner's seemingly unrelated regression (SUR) framework, and bootstrapped standard errors, we test for an impact of this program on alcohol-related injury or fatality accidents, the proportion of all accidents involving alcohol, and the number of DWI arrests. In its first decade, the citizen reward program appears to have averted some 275 alcohol-related accidents for social cost savings of between $21,000 and $5.6 million. Further, possibly 4495 arrests were precluded, saving some $1-3 million in arrest-related costs. Incentivized public monitoring of driving-after-drinking may be an effective drunken driving abatement program though our exploratory findings need further confirmation.     

Novel precipitated silicas: an active filler of synthetic rubber

Highly dispersed silicas have been obtained at a semi-technical scale by precipitation from sodium metasilicate solutions using appropriately diluted solutions of ammonium hydrogencarbonate or ammonium chloride. The difference, as compared to the generally applied technology of silica precipitation using acids or their anhydrides, has been the involvement of the precipitation reaction in alkaline media. Attempts have been made at changing the silica surface character from hydrophilic to more hydrophobic, using a modifier from the group of silane coupling agents. The alkoxysilanes modifiers contained groups with chemical affinity towards functional groups of butadiene–styrene rubber. Modification of silica surface using silane coupling agents has been found to improve the reinforcement of vulcanizates, by increasing the tensile and tear strength in particular.     

Extraction of microamounts of Eu and Am into nitrobenzene using a synergistic mixture of chlorinated hydrogen dicarbollylcobaltate and <Emphasis Type="Italic">N,N′</Emphasis>-diethyl-<Emphasis Type="Italic">N,N′</Emphasis>-diphenyl-2,6-dipicolinamide

Extraction of microamounts of Eu and Am with a nitrobenzene solution of chlorinated hydrogen dicarbollylcobaltate (H⁺B⁻) in the presence of N,N′-diethyl-N,N′-diphenyl-2,6-dipicolinamide (EtPhDPA, L) was studied. The equilibrium data were interpreted assuming that the complexes HL⁺, HL₂⁺, ML₂³⁺, ML₃³⁺, and ML^4/3+ (M³⁺ = Eu³⁺, Am³⁺) are extracted into the organic phase. The extraction and stability constants of the species in water-saturated nitrobenzene were determined. The stability constants of the related complexes EuL _n ³⁺ and AmL _n ³⁺, where n = 2, 3, 4, in this medium are comparable.     

Working with families: A practitioner's perspective:.

Suggests that school psychologists face a challenge to provide assessment and intervention within a family context. Comments are provided on a discussion by J. C. Hansen et al (see record 1990-18461-001) of the types of ethical dilemmas school psychologists are likely to face in providing services to families. The key to providing appropriate and ethical interventions with families will depend on the development of sound policies, professional awareness, and supervision. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Allowable Rates of Fluid Temperature Variations and Thermal Stress Monitoring in Pressure Elements of Supercritical Boilers

ABSTRACT

Allowable rates of fluid temperature changes in critical elements of supercritical steam boilers were determined assuming a quasi-steady state of temperature distribution in pressure components. A method was proposed for monitoring the thermal stresses in the critical pressure components.     

The characteristics of the spontaneous activity of single neurons in the human ventrolateral thalamus during changes in the functional state of the brain

In the thalamic ventro-lateral nucleus of parkinsonian patients, two main types of convergent cells were shown to exist: 1) units with irregular discharges (A-cells, 74%) and 2) units with bursts of unstable rhythmic discharges (B-cells, 26%). The functional brain changes were accompanied by modifications of A-cells activity into the transient rhythmic burst-like pattern, characterized by two different types of intrinsic structure burst discharges being in some cases similar to the structure of B-cells. A correlation between activities of these units and the type of parkinsonian pathology was revealed.     

Executive coaching: The need for standards of competence.

Psychologists working in the emerging competency area of "executive coaching" must promote a more complete understanding of what constitutes effectiveness in this arena—particularly when the expected outcome is sustained behavior change. Experienced psychologists must accept accountability for the need to inform and educate corporate decision makers about the core skills, competencies, experience, and related professional issues critical for successful outcomes. These educative efforts are essential if executive coaching for sustained behavior change is to be established as a respected consultative area adding value to organizationally based leadership development initiatives. The purpose of this article is to begin the dialogue among psychologists about the need to become more proactive in their educative efforts with these decision makers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)