Pulsed laser annealing of GaAs in a high-pressure argon gas ambience

Pulsed laser annealing was carried out for n-type semiconducting GaAs in air, 1 bar nitrogen, 1 bar argon, and 100 bar argon gas ambiences. Depth profiles of the atomic ratio measured by SIMS indicate that pulse annealing in air results in As loss and penetration of oxygen into the crystal, both of which affect dopant redistribution and deteriorate electrical properties of the annealed layer. High electrical activity (100%) and electron mobilities were achieved for high-dose implants of Si⁺ (1 × 10¹⁵ cm⁻²) by pulsed laser annealing in the high-pressure ambience.     

Discrete and non-discrete mixed methods for plate bending analysis

For plate bending analysis, both discrete and non-discrete mixed methods are presented by using spline functions in the Hellinger-Reissner variational principle. Piecewise spline interpolation with local supports and overall spline interpolation with boundary knots are applied to each of two mixed functionals. The prescribed boundary conditions can be considered by multiple boundary knots. The convergence behaviour of the mixed methods presented is studied. Numerical examples show that a high degree of accuracy can be obtained due to continuous properties in the high derivatives of the employed shape functions. The proposed mixed methods are found to be very competitive with other numerical methods for plate bending problems.     

A biosensor in the time domain based on the diffusion coefficient measurement: intermolecular interaction of an intermediate of photoactive yellow protein

A new type of biosensor is presented for the first time. This method is based on the diffusion measurement in the time domain by the transient grating method. As the first demonstration of this new method, various intermolecular interactions with a reaction intermediate of photoactive yellow protein, such as the protein-protein interaction, protein-DNA interaction, and protein-small molecule binding are detected. The characteristic advantages and limitations are summarized.     

Casting of organic glass by radiation-induced polymerization of glass-forming monomers at low temperature. II. Optical strain of remaining stress type

Previously it was found that casting could be carried out efficiently without strain formation by radiation-induced polymerization of glass-forming monomers. Two types of strain were observed in casting: thermal stream type, which was studied previously, and remained stress type. In this report, the effect of various factors on the formation of remaining stress-type strain in radiation-induced casting polymerization was studied. It was found that the molecular weight of prepolymer did not affect strain formation, while prepolymer concentration and viscosity of the system had a serious influence on strain formation. It could be deduced that this type of strain formed as a result of remaining inner stress due to poor relaxation of the shrinking stress. It was realized that less volume shrinkage of glass-forming monomers accompanying casting polymerization reduced the strain formation of this type in radiation-induced casting polymerization at low temperatures.     

Deposition of chlorophyll-a Langmuir-Blodgett films onto an SnO2 optically transparent electrode

The deposition of chlorophyll-a monolayers onto an SnO₂ optically transparent electrode was studied in relation to the deposition ratio. The values of the deposition ratio, which were approximately 0.95 for the upward movement and very small but non-zero for the downward movement, suggest that the multilayers prepared are Z-type films containing a small fraction of the Y-type component corresponding to the non-zero value. This is consistent with the photo- electrochemical behaviour of the pigmented electrodes which is markedly dependent on the deposition ratios, indicating structural inhomogeneity or imperfection of the multilayers.     

Identification of a model of grinding wheel life by the group method of data handling

A mathematical model for grinding wheel redress life is identified by the polynomial theory of complex systems. Wheel speed, feed, grain size and grade are chosen as the independent variables from among the factors considered to have an effect on wheel wear through the identification of the model. The model obtained enables the redress life to be predicted for all combinations of grinding wheel, work material and grinding conditions, and serves as an aid in the optimization of the grinding process.     

Characteristics of women with a family history of ovarian cancer. I. Galactose consumption and metabolism

BACKGROUND: Galactose metabolism may be a risk factor for ovarian cancer based upon evidence that galactose causes ovarian failure and that ovarian cancer arises from premature ovarian failure. This study examines galactose-1-phosphate uridyl transferase (GALT) activity in women with a family history of ovarian cancer (FOC) to determine if low GALT activity occurs in women who are at risk for but in whom ovarian cancer has not yet developed. METHODS: The authors studied 106 premenopausal women (FOC patients) with one primary or two second-degree relatives with ovarian cancer compared with 116 age matched control subjects without a family history of ovarian cancer (FOC controls). All women completed questionnaires and had blood drawn to measure GALT activity and genotype. RESULTS: Mean erythrocyte GALT activity, in micromoles of hexose conversion per hour per gram of hemoglobin was 21.5 in FOC patients, significantly lower than the mean of 23.1 observed in FOC control subjects, (P = 0.001). FOC patients more frequently displayed the Duarte variant of galactosemia as detected by electrophoresis. In a subset of 87 patients and 113 control subjects for whom DNA was available, the allelelic frequency of the Duarte variant based upon molecular genetic detection of the N314D mutation that is associated with the Duarte variant was 15.5% among FOC cases compared with 7.5% among control subjects (P < 0.02). Galactose consumption did not differ between FOC patients and control subjects. CONCLUSION: Galactose metabolism differs between women with and without a family history of ovarian cancer, suggesting that it may be a genetic risk factor for ovarian cancer, possibly mediated through oocyte toxicity from galactose.