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Laboratory batch experiments were performed to assess the reduction of trichloroethene (TCE) and oxygen via natural ferrous minerals. TCE reduction under anoxic conditions was measured via the generation of reduced gases, while oxygen reduction via the generation of hydroxyl radicals was measured as a surrogate for potential TCE oxidation. Results showed that TCE reduction under anoxic conditions was observed for ankerite, siderite, and illite, but not for biotite; acetylene was the primary identified dechlorination product. With the exception of biotite, first-order dechlorination rate constants increased with increasing ferrous content of the mineral, with rate constants ranging from 3.1 × 10−8 to 4.8 10−7 L g−1 d−1. Measured reduction potentials (mV vs SHE) ranged from −104 for illite to +84 for biotite. When normalizing measured first-order dechlorination rate constants to the estimated ferrous iron mineral specific surface area (where surface area was based on nitrogen adsorption analysis of the minerals), TCE dechlorination rate constants increased with increasing reduction potentials. Under oxic conditions, hydroxyl radicals were generated with each of the four minerals. However, mineral activity showed no readily apparent correlation to ferrous content or mineral surface area. In terms of TCE and oxygen reduced per mole of ferrous iron initially present in each mineral, illite was the most reactive of the four minerals. Together, these results suggest that several ferrous minerals may contribute to abiotic dechlorination in the natural environment, and (at least for TCE reduction under anoxic conditions) measurement of ferrous mineral content and reduction potential may serve as useful tools for estimating TCE first-order abiotic dechlorination rate constants. [Display omitted] • Abiotic TCE reductive dechlorination was observed using ankerite, siderite, and illite. • TCE dechlorination rate constants generally increased with increasing ferrous content. • TCE dechlorination rate constants generally increased with decreasing reduction potential. [ABSTRACT FROM AUTHOR]

Diffusion through a water saturated silty clay soil column was measured for six perfluoroalkyl acids (PFAAs), including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS). An aqueous pore diffusion model, which incorporated linear adsorption parameters measured independently in batch tests and a tortuosity factor determined independently using a bromide tracer test, was used to describe the experimental diffusion data. The diffusion model substantially underpredicted PFAA diffusion through the soil column for the more strongly sorbing PFAAs (most notably PFOS). Instead, application of a diffusion model that included a surface diffusion-like process provided substantially improved prediction of PFAA diffusion through the soil. The ratio of the observed pore diffusion coefficient to the observed surface diffusion coefficient ranged from 13 (for perfluorohexane sulfonate) to 0.88 for PFOS. These results suggest that surface diffusion serves a potentially important role for strongly sorbing PFAAs in clay-rich soils, and highlights the need for additional studies into the coupled adsorption and diffusion of PFAAs in low permeability media. [Display omitted] • Coupled adsorption and diffusion of PFAAs were measured through a clay-rich soil. • A pore diffusion model underpredicted migration for the more strongly sorbing PFAAs. • Surface diffusion served an important role for strongly sorbing PFAAs. [ABSTRACT FROM AUTHOR]

Examines the difference in phase continuity between spreading and nonspreading oils at low saturation by measuring the oil phase effective diffusivity. Demonstration of higher effective diffusivities by 1-octanol than the n-dodecane; Development of models for predicting the behavior of the oils in the unsaturated porous medium.

SUMMARY An important aspect of the personality theory of Transactional Analysis is the ego state concept. The psyche of every individual is postulated to have three components: Parent, Adult, and Child. A special Transactional Analysis (TA) scale for the Adjective Check List (ACL) was developed to assess the positive and negative aspects of the three ego states. The ACL is a popular self-report measure of personality traits. The TA scale appears to hold promise for understanding the personality dynamics of an individual and his interpersonal relations. [ABSTRACT FROM AUTHOR]

Ten high school girls were identified as exceptionally creative on the basis of teacher nominations and test scores. Historical, personality, and projective data were collected by means of tests and interviews. Particular emphasis was placed on life history antecedents of creative achievement. The highly creative girls were found to possess a number of common characteristics, particularly in the areas of familial and educational history, leisure time activity, fantasy experience, and self concept. [ABSTRACT FROM AUTHOR]

This study assessed the long-term effectiveness of bioremediation as a remedial strategy for a chlorinated, ethene dense, non-aqueous phase liquid (DNAPL) source area, consisting of a higher- and a lower-permeability zone at Alameda Point, California. The evaluation was performed over 3.7 years after cessation of active source area bioremediation using passive flux meters (PFMs), push-pull tracer tests, and soil cores. PFMs showed that total chlorinated ethene molar discharge emanating from the source area remained relatively unchanged pre-and post-bioremediation, but molar discharge compositions shifted from trichloroethene (TCE) and cis -1,2-dichloroethene (cis -DCE) to vinyl chloride (VC) and ethene dominated during post-remedial monitoring. First-order rate constants, derived from PFM data at the edge of the source area and describing the complete dechlorination of TCE at 3.7 years following active bioremediation, were approximately 1.05 yr−1, which was over three times lower than the rate 3.6 yr−1 determined using compound stable isotope analysis (CSIA). Soil cores and push-pull tracer test data showed that DNAPL volume estimates were relatively unchanged pre- and post-bioremediation due to the remaining presence of DNAPL in the lower-permeability zone. These data suggest biotransformation processes are continuing in the higher-permeability zone, whereas DNAPL in the lower-permeability zone continues to serve as a significant source of groundwater contamination. The results suggest that it will take many years under current conditions to attain the United States Environmental Protection Agency (EPA) Maximum Contaminant Levels (MCLs) cleanup objectives. • Chloroethene discharge remained relatively unchanged pre- and post-bioremediation. • Mass discharge composition shifted from TCE and cis -DCE to VC and ethene dominated. • DNAPL mass estimates remained unchanged pre- and post-bioremediation. • MCLs were not achieved in the source area or plume. [ABSTRACT FROM AUTHOR]

Although electrochemical treatment has received increased attention with respect to treating poly- and perfluoroalkyl substances (PFAS), studies assessing treatment longevity for the wide range of PFAS present in water impacted by aqueous film-forming foam (AFFF) are lacking. A 21-day study was performed in which electrochemical treatment using boron-doped diamond (BDD) anodes was performed in successive 24-h batch cycles on groundwater impacted with AFFF. Results showed substantial defluorination of both the perfluoroalkyl acids (PFAAs) and defluorination of polyfluoroalkyl compounds (based on fluoride generation). Substantial perchlorate generation was observed throughout the study. PFAS treatment effectiveness diminished over time due to scaling, resulting in decreased removal of the PFAAs and generation of perfluorobutanoic acid (PFBA). Based on measured generation of fluoride relative to the concentrations of the PFAAs, defluorination of the polyfluoroalkyl acids decreased 2–3 times more than the PFAAs due to this scaling. This suggests that defluorination of the polyfluoroalkyl acids occurred via a mechanism different from that of the PFAAs. Acid cleaning to remove the accumulated scale resulted in restoration of PFAS treatment. Together, these results suggest that electrochemical treatment of AFFF-impacted waters shows promise. Polyfluorinated compounds and PFBA showed greater adverse impacts from the mass transfer and/or residence time decreases associated with the scaling than what was observed for the other PFAAs. This implies that these compounds may prove to be the greater challenge in long-term full-scale applications. [ABSTRACT FROM AUTHOR]

Investigates the relationship between two measures of social attraction or status, the Comfortable Interpersonal Distance Scale and a traditional measure of sociometric status. Indication that the two measures were highly correlated; View that physical interpersonal distance seems to be a nonverbal way of communicating likeing for a person.

Simplified analytical solutions, developed as source strength functions (SSFs), are capable of describing the temporal dissolution of nonaqueous phase liquids in groundwater, which is useful for predicting source longevity and can serve as a guide for remedial activities. Here, SSF parameters were estimated by fitting enhanced aqueous dissolution data from a flow cell consisting of three injection and four extraction wells to analytical dissolution models (power law model (PLM) and equilibrium streamtube model (EST)) at a trichloroethene (TCE) contaminated site, Alameda Point, California. Both the PLM and the EST model were able to characterize the observed aqueous TCE dissolution during enhanced water flooding. Additional field activities conducted at the site included soil core collection, a recirculated partitioning tracer test, passive flux meter transects, and push–pull tracer tests. The additional site characterization data were used to independently estimate the observed SSF parameters using information such as the TCE mass, distribution and porous media heterogeneity. The exponential decay model (a subset of the PLM) accurately predicted the enhanced dissolution, likely because the site was significantly aged (most of the mass in the plume rather than in the source zone) or middle stage, and the mass in the source zone could be approximately estimated. The EST tracer-based model, when combined with data from the recirculated partitioning tracer test, soil cores, and the push–pull tracer test, was capable of accurately predicting the observed aqueous dissolution. The mass in the source zone and the fraction of contaminated flowpaths were the most important site characteristics, requiring the greatest accuracy to predict aqueous dissolution. Establishing steady state dissolution was essential to provide a more accurate estimate of the fraction contaminated and high resolution data from soil cores in the source zone were needed to estimate the mass present. [ABSTRACT FROM AUTHOR]