Forms of Hydraulic Fractures in Shallow Fine-Grained Formations

Hydraulic fractures have been created in fine-grained formations at depths of 2–10 m to improve the performance of environmental remediation projects at dozens of locations and in a wide range of geologic conditions. The effectiveness of a hydraulic fracture during remediation will depend primarily on its form; that is, its shape, thickness, orientation, length, width, and location with respect to the borehole. The forms of many hydraulic fractures have been determined by mapping exposures in excavations and by compiling split-spoon sampling data. These observations indicate that a typical hydraulic fracture at shallow depths is gently dipping, slightly elongate in plan, and slightly asymmetric with respect to the parent borehole. Shallow hydraulic fractures lift the ground surface to produce gentle domes, and the pattern of uplift reflects the location and thickness of the fracture at depth. The forms of hydraulic fractures created over a narrow range of depths at the same site are similar, but the forms can vary markedly between sites and at different depths at the same site. This indicates that the forms of hydraulic fractures will be relatively consistent when they are created under similar conditions, but changes in geologic conditions can markedly affect fracture form.     

Menstrual cycle, beta-endorphins, and pain sensitivity in premenstrual dysphoric disorder.

This study examined pain sensitivity and pain modularity mechanisms (e.g., beta-endorphin levels, blood pressure) in women with premenstrual dysphoric disorder (PMDD; n=27) and healthy controls (n=27) during the follicular and luteal phases of the menstrual cycle. Physiological measures were taken during rest and ischemic pain testing. In both cycle phases, PMDD women (a) displayed lower resting cortisol and beta-endorphin levels and (b) exhibited shorter pain threshold and tolerance times and greater pain unpleasantness ratings during pain. PMDD women also reported greater pain unpleasantness and intensity and had lower beta-endorphin levels in their luteal phase and tended to display higher blood pressure levels at rest and during pain testing. Results suggest that endogenous opioids may be pathophysiologically relevant to PMDD and that the hypothalamic-pituitary-gonadal axis may modulate pain sensitivity in PMDD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time horizons in rats foraging for food in temporally separated patches.

An important tenet of optimal foraging theory is that foragers compare prey densities in alternative patches to determine an optimal distribution of foraging behavior over time. A critical question is over what time period (time horizon) this integration of information and behavior occurs. Recent research has indicated that rats do not compare food density in a depleting patch with that in a rich patch delayed by an hour or more (Timberlake, 1984). In the present research we attempted to specify over what time period a future rich patch would affect current foraging. The effect of future food was measured by early entry into the rich patch (anticipation) and by a decrease in food obtained in the depleting patch (suppression). The rats showed anticipation of a rich patch up to an hour distant, but suppressed current feeding only if the rich patch was 16 min distant or less. The suppression effect appeared mediated by competition for expression between anticipatory entries into the rich patch and continued foraging in the depleting patch. These results suggest that optimal foraging is based on a variety of specific mechanisms rather than a general optimizing algorithm with a single time horizon. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Starke Rosecrans Hathaway (1903–1984).

Presents an obituary for Starke Rosecrans Hathaway. Hathaway obtained both his undergraduate and master's level training with James P. Porter at Ohio University in Athens. He earned his undergraduate degree in psychology in 1927 and his master's degree in 1928. Porter persuaded him to remain in Athens as an instructor in psychology and physiology; by 1929 he held the rank of assistant professor. Hathaway's original interests in engineering persisted; he perfected and marketed a chronoscope, a psychogalvanometer, and electrical stimulation and recording devices for the study of neural processes. It is interesting to recall that one of the first uses to which Hathaway had put his psychogalvanometer was as a lie detector in helping police in Athens to solve a murder case. Hathaway's contributions to clinical psychology were recognized at the national level by the APA's Division of Clinical Psychology, which conferred its Distinguished Scientific Contribution Award in 1959 and elected him as its president in 1963. Elected to Sigma Xi and Phi Beta Kappa, an ABPP diplomate in clinical psychology, he was awarded honorary doctorates by Ohio University in 1966 and by Ohio State University in 1972. His honors were capped in 1977 when the APA conferred its award for Distinguished Contribution for Applications in Psychology. Hathaway retired from the University of Minnesota in 1971. He died at his home in Minneapolis on July 4, 1984. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Benzofuran-terminated infrared dyes and their electro-optic properties in guest-host polymers

Molecular first hyperpolarizabilities and dipole moments of new benzo-fused dyes were calculated using quantum-mechanical density functional theory (DFT). Two new infrared dyes were synthesized: each one was terminated with 6-diethylaminobenzo[b]furan on one end, and with CF₃-tricyanodihydrofuran on the other end. The midsection of the π-electron framework for one dye contained a morpholino-substituted cyclohexenylene unit, and the other dye contained an ethoxysiloxane-substituted cyclohexenylene unit. Guest-host films were deposited on ITO-glass and contact poled. Electro-optic coefficients (r₃₃) were measured at a wavelength of 1550 nm by the attenuated total reflection method and by a modified simple Teng-Man reflection method. The measured values of r₃₃ were compared with values estimated from a well-known model that employs the molecular properties of the dyes and the film poling parameters. Thermal stability and electronic absorption spectra of the dyes were measured.     

The effect of shot particles on the fatigue of Kaowool fiber-reinforced 339 aluminum

The addition of Kaowool fibers substantially increases the fatigue strength of 339 aluminum at 300 °C. However, the fatigue life of these composites is limited by the presence of Kaowool “shot” particles, which act as crack initiation sites. An elastic analysis of the stress concentrations associated with this type of defect shows that a crucial parameter is the distance of the particle from the free surface. As the distance from the surface decreases, the stress concentration factor increases substantially and attains maximum value when a small portion of the particle has been removed by machining. The relationship between the distance from the surface and the stress concentration factor is in excellent agreement with the particle geometries observed at fatigue crack initiation sites.     

Phosphine functionalized polyaniline nanostructures

We study the problem of limited functionalization options for polyaniline through the surface attachment of phosphine coupling reagents. These studied linkers are P(CH₂OH)₃ and Ph₂PCH₂OH, and are attached to both conventional and nanostructured polyaniline. Additionally, model compounds are considered, extending the scope of our analysis. The successful attachment results indicate the potential for further functionalization, using the hydroxymethyl terminal groups of the phosphines for primary and secondary amine chemistry. These results should enable the development of sensitive and molecule-specific polyaniline-based devices.     

Pilot scale isolation of proteins from field peas (Pisum sativum L.) for use as food ingredients

Summary The protein and starch fractions of field pea ( Pisum sativum L.) are potentially a source of novel ingredients for food processing. As part of research to elucidate the functional properties of field pea proteins, the pilot scale extraction of proteins has been undertaken. Two different approaches have been used and the recoveries of protein compared. The first involved extraction with a salt solution followed by decanting and clarification to remove solids. The solution was then further concentrated and salt removed by ultrafiltration and diafiltration. The second procedure was based upon alkaline extraction followed by decanting and recovery by isoelectric precipitation and neutralisation. Both spray drying and freeze drying methods were employed. The protein isolates have been compared and characterised with respect to solubility, chemical composition and to electrophoretic patterns. Overall, the proteins extracted with salt exhibited better physical properties than proteins extracted with alkali, in terms of colour and particle size. The solubilities showed little variation and the electrophoretic patterns were similar. Freeze drying resulted in isolates with darker colour compared with spray drying.