POTASH–SODA–LIME FELDSPAR EUTECTIC STUDY*

An investigation was made of the fusion behavior of the potash feldspar, soda feldspar, and soda-lime feldspar system, all materials being of commercial grade. The potash feldspar had a pyrometric cone equivalent of cone 9½, the soda feldspar, cone 6½, and the soda-lime feldspar deformed at cone 11½. Mixtures varying according to the triaxial diagram were made in the form of pyrometric cones. These were fired in groups along with standard Orton cones. The 30% commercial potash feldspar-70% commercial soda feldspar mixture reached 6 o'clock deformation when standard Orton cone 6 showed 2 o'clock deformation. The mixture of 62½% commercial potash feldspar with 37½% soda-lime feldspar reached 6 o'clock deformation when cone 7 showed 1 o'clock deformation, the deformation of the cone 9½ potash feldspar being reduced 3 cones by the addition of the proper percentage of the cone 11½ soda-lime feldspar. There was an increase in deformation temperatures (no indication of eutectic) in the plagioclase series, soda feldspar to soda-lime feldspar. The mixture of 30% commercial potash feldspar, 60% commercial soda feldspar, 10% soda-lime feldspar showed 6 o'clock deformation when cone 6 showed 1 o'clock deformation, this being the lowest temperature at which any member of the system showed 6 o'clock deformation.     

Spectral and complexity analysis of scalp EEG characteristics for mild cognitive impairment and early Alzheimer's disease

Amnestic mild cognitive impairment (aMCI) often is an early stage of Alzheimer's disease (AD). MCI is characterized by cognitive decline departing from normal cognitive aging but that does not significantly interfere with daily activities. This study explores the potential of scalp EEG for early detection of alterations from cognitively normal status of older adults signifying MCI and AD. Resting 32-channel EEG records from 48 age-matched participants (mean age 75.7 years)—15 normal controls (NC), 16 early MCI, and 17 early stage AD—are examined. Regional spectral and complexity features are computed and used in a support vector machine model to discriminate between groups. Analyses based on three-way classifications demonstrate overall discrimination accuracies of 83.3%, 85.4%, and 79.2% for resting eyes open, counting eyes closed, and resting eyes closed protocols, respectively. These results demonstrate the great promise for scalp EEG spectral and complexity features as noninvasive biomarkers for detection of MCI and early AD.     

Characteristics of Cast Stone cementitious waste form for immobilization of secondary wastes from vitrification process

The high-temperature in vitrification process of radioactive wastes could cause radioactive technetium (⁹⁹Tc) in secondary liquid wastes to become volatile. Solidified cementitious waste forms at low temperature were developed to immobilize radioactive secondary waste. This research focuses on the characterization of a cementitious waste form called Cast Stone. Properties including compressive strength, surface area, phase composition, and technetium leaching were measured. The results indicate that technetium diffusivity is affected by simulant type. Additionally, ettringite and AFm (Al₂O₃–Fe₂O₃–mono) main crystalline phases were formed during hydration. The Cast Stone waste form passed the qualification requirements for a secondary waste form, which are compressive strength of 3.45 MPa and technetium diffusivity of 10^?9 cm²/s. Cast Stone was found to be a good candidate for immobilizing secondary waste streams.     

Studies on the cure characteristics and vulcanizate properties of 50/50 NR/SBR blend

Blends of 50/50 natural rubber (NR) and styrene-butadiene rubber (SBR) are vulcanized using several conventional and semi-EV systems. The cure characteristics and vulcanizate properties are compared. The quantity and quality of crosslinks in each case are deciphered by chemical probes to correlated them with the vulcanizate properties.     

Corrosion of high temprature alloys in the primary circuit helium of high temperature gas cooled reactors. – Part I: Theoretical background

The interaction of Ni and Fe-Ni base alloys with the reactive impurities H₂O, CO, H₂ and CH₄ in simulated cooling gas of the primary circuit of the High Temperature Gas Cooled Reactor (HTGR) causes corrosion effects that can significantly influence the mechanical properties. Apart from the formation of surface scales (oxides, carbides or mixed oxides/carbides), structural changes of the alloys are observed; depending on gas composition, gas supply rate and test temperature, carburization or decarburization can occur. In this report it is shown that an interpretation of the basic corrosion effects is possible on the basis of a modified stability diagram for chromium provided that - the kinetics of elementary gas metal reactions are incorporated in the expressions for carbon activity and oxygen partial pressure of the atmosphere and - the gradients of the potentials across the surface scales are taken into account. The interpretation allows the derivation of the corrosion behaviour of NiCr-base alloys in different HTGR helium compositions and enables the limits for the formation of protective chromia surface scales to be given. The influence of alloying elements other than chromium can be explained qualitatively. The results can be transferred to other reactive gas mixtures, which are characterized by an oxygen partial pressure near to the dissociation pressure of the scale forming oxides.     

Humanities computing 25 years later

This paper attempts to provide an overview of the development of humanities computing during the past twenty-five years. Mention is made of the major applications of the computer to humanities disciplines, and of the most important and representative projects across the world. Joseph Raben, professor emeritus at Queens College, The City University of New York, is founding editor of Computers and the Humanities. He is currently establishing an edited computer conference, SCHOLAR.     

William A. Hunt (1903–1986).

William A. Hunt was one of our country's early scientist-clinicians. He began his career with study of a psychology that was a meld of Titchener's structuralism and Harvard's functionalism and completed it 50 years later in the field of health psychology. Hunt spent all but a few of those 50 years as a full-time teacher, at schools that included Dartmouth College, Connecticut College for Women, and Northwestern University. While doing his dissertation, he had mastered and used the structuralist's experimental method of introspection, applying it to the study of human emotion, specifically the James-Lange theory. In 1941, Hunt entered the Navy. He discerned that the screening for military duty of some 15 million women and men required an approach suited to the rapid, albeit individual, screening of large numbers of such personnel. His teaming up with a psychiatrist, Cecil Wittson, led to their joint development of a screening interview lasting one to two minutes that, with continued refinement, proved remarkably effective. Their goals as the mental health specialists participating in the medical examination conducted at this intake station were twofold: (a) to improve the efficiency of the Navy by removing those neuropsychiatric high-risk recruits who were potential psychiatric casualties if they continued in the Navy and (b) by such removal, to save these recruits the disastrous personal experience of subsequent breakdown during military duty. In his own still active research in the 1960s and 1970s Hunt continued to apply the same methods he earlier had used (in his Navy research) to the judgmental processes clinical psychologists used to identify psychological test responses that were pathognomonic of schizophrenia, mental retardation, and related forms of psychopathology. Hunt remained, until his death at age 82, an active scientist-clinician. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modified spontaneous emission in oligo (p-phenylene vinylene) planar microcavities

This paper reports on the photoluminescence properties of phenylene vinylene oligomers films (OPV) the emission of which was modified by microcavity effect. Films with 4 and 6 vinyl groups (respectively denoted OPV-4 and OPV-6) were investigated. A strong blue luminescence at 470 nm is observed for OPV-4. OPV-6 shows an emission spectrum quite similar to that of poly phenylene vinylene (PPV). Photoluminescence excitation measurements (PLE) give similar behaviors for the two samples and do not show any change in the shape of the spectra. Ageing under UV irradiation (380 nm) of the unencapsulated OPV-4 layers was evidenced by an exponential decrease of the photoluminescence intensity of about 40% after 3 h a continuous illumination. OPV-6 samples, aged on shelf, for weeks does only show a small decrease (15%) of the PL level over more than 7 h under continuous UV irradiation. Microcavity related effects were observed by inserting the films between two mirrors. These are generally a TiO₂/SiO₂ distributed Bragg reflectors (DBR) as bottom mirror and a Ag film as top mirror. However best results were obtained with two dielectric DBR. As expected, a strong enhancement of the emission at the cavity resonance and pronounced angular effects (emission peaking in the direction normal to the surface of the device) were observed. The importance of the position of the emitting material within the microcavity is evidenced with a thin tris(8-hydroxy) quinoline aluminum (Alq) embedded in SiO₂ with various cavity configurations.