Treatment of an Iron-rich ARD Using Waste Carbonate Rock: Bench-Scale Reactor Test Results

The treatment of acid rock drainage (ARD) places extraordinary financial burdens on governments and companies worldwide, and an improved efficiency in treatment by as little as 1% can save many millions of dollars in rehabilitation. We investigated a system for treating Fe-rich ARD using a three-stage reactor design. In the first reaction cell, Fe-rich ARD was partially neutralised using rapid periodic carbonate resuspension with a rotating axial mixer. This was followed by an air-sparged oxidation chamber and then a second reaction cell, with more carbonate periodically resuspended until a pH of 6.3 was reached, which was followed by a settlement chamber. This reactor design has a high capacity for neutralisation, with an efficiency of ≈70% of acidity neutralised by the acid neutralising capacity (g of CaCO₃ equivalent) added to the reactor. Axial mixers were tested because of their low-energy requirements and their high reliability. The intermediate chamber effectively removes Fe by oxidising Fe(II) to Fe(III). Given the amount of acidity neutralised, the sludge volume produced was low compared to other technologies, providing further potential savings in sludge handling. Waste carbonate rock proved to be an effective neutralising agent, even though it was about 60% dolomite and 40% magnesite, with minor calcite, and despite the fact that magnesite has substantially slower dissolution kinetics compared to the more dominant dolomite. The mixed waste carbonates were capable of raising the pH sufficiently to reduce the heavy metal loadings in Fe-rich ARD by more than two orders of magnitude. The final settlement stage of the process was shown to be essential for metal precipitation, for the carry-over of fine carbonates, and CO₂ loss. This was associated with a rise in pH, from 6.3 to 7.5. In addition, residual slow-reacting magnesite from the mixed carbonate remains in the sludge from the first reactor and provides acid buffering capacity within the sludge, which is commonly lacking in the ARD neutralisation sludge of other systems.     

Dreams and reality monitoring.

Exp I tested the counterintuitive prediction that memories for one's own dreams should not be particularly easy to discriminate from memories for someone else's dreams. 10 pairs of undergraduate and graduate students reported dreams to each other that they had either dreamed, read, or made up the night before. On a test requiring them to discriminate events they had reported from those reported by their partner, Ss had more difficulty with real dreams than with dreams they read or made up. Data from 10 new pairs of Ss in Exp II provide evidence that real dreams do not simply produce overall weaker memories; the deficit for dreams was eliminated with more time to respond and with more detailed cues. In addition, Ss' ratings of various characteristics of their memories (e.g., vividness, personal relevance) indicated that dreams were not generally weaker or impoverished. Results are interpreted within the framework for reality monitoring described by M. K. Johnson and C. L. Raye (1981). A comparison of recognition and recall indicated that dreams may leave persisting memories that are difficult to access via free recall. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

(Z)6, (E)8-Heneicosadien-11-One: Synergistic Sex Pheromone Component of Douglas-Fir Tussock Moth, Orgyia pseudotsugata (McDunnough) (Lepidoptera: Lymantriidae)

Three candidate sex pheromone components, (Z)6,(Z)9-, (Z)6,(E)8-, and (Z)6,(E)9-heneicosadien-11-one (Z6Z9, Z6E8, and Z6E9) were identified in pheromone gland extracts of female Douglas-fir tussock moths (DFTM), Orgyia pseudotsugata (McDunnough). Their occurrence in subnanogram quantities in extracts and structural conversion during analytical procedures and bioassays complicated chemical identifications. Complete identification required comparative analyses of stereoselectively synthesized and female-produced dienones by coupled gas chromatographic–electroantennographic detection (GC-EAD), high-performance liquid chromatography (HPLC) and coupled GC–mass spectrometry (MS). Determination of the pheromone component was contingent upon an experimental design that minimized structural rearrangement of dienones before and during the field test. In a 40-min field experiment, acetonitrile solutions of each of the above dienones were carried on Dry Ice to traps and were syringed onto cotton release devices below trap lids. In combination with the previously known sex pheromone component of DFTM, (Z)6-heneicosen-11-one (Z6), Z6E8 was the only synergistic dienone and the mixture was highly attractive. Because Z6 by itself attracts seven species of tussock moths (two sympatric with DFTM), a blend of Z6 and Z6E8 may impart specificity to DFTM pheromone communication. In commercial lures, this binary blend may facilitate species-specific, sensitive monitoring and efficacious control by mating disruption of this important forest defoliator.     

Therapist complementarity as a function of experience and client stimuli.

Assessed degree of therapist (TP) complementarity (CMP), an interpersonal communication strategy, in 67 TPs' responses to client statements (CSTs) that varied on 3 dimensions (directness, power, and type of affect as it varied over TP experience level). TPs at all experience levels responded similarly to different types of CSTs. CMP was lowest in response to hostile-dominant CSTs and highest in response to hostile-submissive CSTs. Differences in CMP were found across levels of experience toward direct and indirect CSTs. Professional TPs were significantly more likely to respond to indirect client statements with lower CMP than were student TPs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The structure of interests and self-efficiency expectations: An expanded examination of the spherical model of interests.

A questionnaire packet assessing occupational preferences, activity preferences, and career self-efficacy expectations was administered to 2 samples of college students. The structural invariance of each data set (activity, self-efficacy, and occupation items) was examined for the 1st sample via principal-components analysis and they correlated. The structure was found to be highly similar across data types. The items were then aggregated into 18 scales representing the spherical model of interests proposed by T. J. G. Tracey and J. Rounds (1996b). The 18 scales were found to fit the spherical model for both the original and validation samples. No gender differences in the structure of the scales were found, but there were gender mean differences found in the scale scores similar to results of past research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Disability and coping as predictors of psychological adjustment to rheumatoid arthritis.

Rheumatoid arthritis (RA) patients have been identified as a medical population at risk for psychological disorder, largely because of the pain and functional disability that are the hallmarks of the disease. This study examined the degree to which self-reported functional disability and coping efforts contribute to psychological adjustment among adult RA patients over a 6-month period. Adaptive outcomes included maintaining a sense of worth, mastery, and positive affect despite the illness. Hierarchical multiple regression analyses indicated that increases in disability were related to decreased acceptance of illness and increased negative affect. Coping efforts were related to increases in positive affect. The findings provide modest support for the role individual coping efforts play in shaping illness-related outcomes. Although disability is not easily reversed, knowledge about coping strategies that moderate its psychological impact may provide a useful basis for designing psychological interventions to promote adjustment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Empirical evaluation of DSM-IV generalized anxiety disorder criteria in children and adolescents

Evaluated the Diagnostic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV], American Psychiatric Association, 1994) generalized anxiety disorder (GAD) criteria in children and adolescents. Clinic-referred children meeting criteria for DSM-IV GAD, those meeting criteria for another DSM-IV anxiety disorder, and normal children participated in a structured interview and completed self-report questionnaires. Groups were compared in terms of interview and self-report measures to examine convergent and discriminant validity. In addition, developmental differences, cross-informant symptom and syndrome agreement, and validity of parent and child report were determined. Finally, the symptoms comprising the GAD associated symptom criterion (Criterion C) were examined in terms of rate of endorsement and predictive power. Results showed that parameters of worry differentiated children with GAD from those with other anxiety disorders and controls. Developmental differences in the sample did not appear to necessitate a separate criteria set for the classification of generalized anxiety in children of this age. Symptoms from GAD Criterion C evidenced moderately high rates of endorsement and acceptable predictive power. Overall, the DSM-IV GAD criteria for children and adolescents are supported, but further evaluation is necessary before firm conclusions can be drawn.     

Help seeking and problem perception among Asian Americans.

Compared the presenting concerns of 3,050 counseling center clients (undergraduate and graduate students) as those concerns varied by ethnicity, gender, and previous counseling experience. Asian-American clients were much more likely to perceive themselves as having educational or vocational concerns, whereas White clients were disproportionately more likely to admit to personal or emotional concerns. The comparison among 7 different Asian-American groups revealed that Filipino-American and Asian-American/White mixed clients were more likely to endorse personal or emotional concerns than other Asian-American groups. Gender and previous counseling experience were found to be related to the presenting concern, but the effects were the same in each ethnic comparison. Results are interpreted with respect to (1) what counselors should be aware of in interacting with Asian-American clients and (2) how they differ both from White clients and among themselves. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Autonomous vehicles: challenges,opportunities, and future implications for transportation policies

This study investigates the challenges and opportunities pertaining to transportation policies that may arise as a result of emerging autonomous vehicle (AV) technologies. AV technologies can decrease the transportation cost and increase accessibility to low-income households and persons with mobility issues. This emerging technology also has far-reaching applications and implications beyond all current expectations. This paper provides a comprehensive review of the relevant literature and explores a broad spectrum of issues from safety to machine ethics. An indispensable part of a prospective AV development is communication over cars and infrastructure (connected vehicles). A major knowledge gap exists in AV technology with respect to routing behaviors. Connected-vehicle technology provides a great opportunity to implement an efficient and intelligent routing system. To this end, we propose a conceptual navigation model based on a fleet of AVs that are centrally dispatched over a network seeking system optimization. This study contributes to the literature on two fronts: (i) it attempts to shed light on future opportunities as well as possible hurdles associated with AV technology; and (ii) it conceptualizes a navigation model for the AV which leads to highly efficient traffic circulations.