Ligand field absorption spectra of quenched MnO−SiO2-Base slags equilibrated with various oxygen and sulfur pressures

Absorption spectra in the visible range have been measured on quenched, glassy MnO?SiO₂ slags, equilibrated with various oxygen and sulfur pressures at 1350°C. The absorption peaks are due to the electron transitions between different energy levels of 3d shell of divalent manganese cation Mn²⁺. The charge transfer bands habe also been measured. From the positions of the peaks and the charge transfer bands, the following results are deduced: sulfur is dissolved in silicate slags predominantly as free sulfur anions but not combined in silicate anion polymers. The tetrahedral arrangement of oxygen anions around a managanese cation is more favorable than the octahedral at higher oxygen and sulfur pressures and smaller CaO content. Electronic conduction in slags, generally very slight compared with ionic conduction, will be increased with increase in oxygen and sulfur pressure and decrease in CaO content. The reproducibility of the peak positions was within 50 cm^?1 or 0.006 ev and the relative error in the molar extinction coefficient was estimated to be ±15 pct. The quenching rate had no effect on the absorption spectra.     

Development of automatic cross fractionation: Combination of crystallizability fractionation and molecular weight fractionation

An automatic cross-fractionation system is presented by combining a newly developed crystallizability fractionation device based on the principle of isothermal dissolution with a commercially available GPC. The detail design, procedure, and operation variables are described. The fractions eluted from the device are characterized by use of an infrared spectrometer and a differential scanning calorimeter for clearing the mechanism of it. As the result of the study, it is found that the system is very useful for characterizing semicrystalline polymers.     

A pattern synthesis of circular arrays by phase adjustment

A problem of sidelobe suppression of a uniformly excited circular array of monopoles through the adjustment of the excitation phases is dealt with. For this purpose, the method of approximation programming (MAP) is used to determine the optimum excitation phases which minimize the sidelobe level. Galerkin's method is used to analyze the mutual coupling between array elements. The resulting radiation pattern has equal amplitude sidelobes that are lower than those obtained with a cophasal array. The resulting radiation pattern of a 32-element double-ring array, operating atX-band, was measured and reasonable agreement with theory was obtained.     

A generalized two-environment model for micromixing in a continuous flow reactor—II. Identification of the model

The dynamic behavior of an actual continuous stirred tank reactor in which a second-order reaction takes place was measured and the model which describes the micromixing phenomena within the reactor was identified. The generalized two-environment model was adopted and its environment function and the collision frequency of each fluid element were determined. Although the conventional two-environment model and the conventional coalescence-redispersion model were also identified, the applicability of these models was poor relative to that of the generalized two-environment model.     

Characteristics of hot-pressed fiber-reinforced ceramics with SiC matrix

Silicon carbide ceramics’ matrix composites with SiC or C filaments were fabricated through hot pressing, and the effects of the filament pullout on their fracture toughness were experimentally investigated. The C-rich coating layers on the SiC filaments were found to have a significant effect on the frictional stress at the filament/matrix interfaces, through assising the filamet pullout from the matrix. Although the coating layers were apt to burn out in the sintering process of SiC matrix compposites, a small addition of carbon to the raw materials was found to be effective for the retention of the layers on the fibers, thus increasing the fracture toughness of the composites. The fracture toughness of the C filament/SiC matrix composite increased with temperature due to the larger interfacial frictional stress at higher temperatures, because of the higher thermal expansion of the filament in the radial direction than that of the matrix.     

Ultrastructural features of the AIDS virus (HIV) and its morphogenesis

HIV particles were usually seen on the surface of established lymphoid cells derived from AIDS patients or on CEM cells infected with HIV, and sometimes in cytoplasmic vacuoles. The virus particles were formed by a budding process from the plasma membrane of an infected cell. The budding particles were of a doughnut form. Various profiles of virus particles were seen extracellularly: type 1 had a bar-shaped, electron-dense core, type 2 had a central and type 3 an eccentric electron-dense round core, type 4 was doughnut-shaped, and type 5 had a layered core. However, projection patterns of the AIDS virus model suggested that type 1, 2 and 3 particles are similar. Therefore, the AIDS virus may be one of three main types: with or without a dense core, and with a layered core. It is thought that a particle with a layered core and a doughnut-type particle may be immature viruses.     

Effect of glycerol on triglyceride metabolism in the rat

Lipid metabolic studies were carried out on the male Wistar rats fed on glycerol-rich diet in order to elucidate the mechanism of glycerol-induced hypertriglyceridemia. No difference was found between the glycerol fed rats and the control rats in the rate of triglyceride secretion from the liver measured by the Triton WR-1339 method as well as in the rate of incorporation of labeled glycerol into liver triglyceride. The facts that the half-life of the intravenously injected Intralipid in the blood was significantly delayed in the glycerol fed rats and that the lipoprotein lipase activity released from epididymal adipose tissue of the glycerol fed rats was markedly decreased to 19% of that of the control rats seem to account for the serum triglyceride elevation induced by the glycerol feeding.     

Simultaneous analysis of four diuretic drugs by HPLC and its application to health food supplements advertising weight reduction

A high-performance liquid chromatographic (HPLC) method for the simultaneous analysis of triamterene, trichlormethiazide, furosemide and spironolactone is presented for application in the examination of health food supplements advertising weight reduction and in the analysis of pharmaceuticals. The HPLC assay was performed under gradient conditions using a Wakosil ODS 5C18 column (5 microns, 150 x 4.6 mm i.d.). The mobile phase consisted of a gradient program with a mixture of water and acetonitrile containing 0.1% triethylamine adjusted with phosphoric acid to pH 3.0: from 0 to 6 min, 15% acetonitrile; from 6 to 20 min, linear gradient from 15 to 50% acetonitrile; and from 20 to 40 min, 50% acetonitrile. The column effluent was monitored from 0 to 20 min at 260 nm and from 20 to 40 min at 235 nm. The calibration curves of the four drugs showed good linearity and the correlation coefficients were better than 0.999 in all cases. The lower limits of detection were approximately 40 ng for each drug. Commercially available health food supplements and pharmaceuticals were analyzed after extraction with a mixture of methanol and acetic acid (99:1). The procedure described here is suitable for the screening of four diuretic drugs in adulterated supplements and for the quality control of pharmaceuticals with minimal sample preparation.     

Characterization of the supermirror hard-x-ray telescope for the InFOCmuS balloon experiment

A hard-x-ray telescope is successfully produced for balloon observations by making use of depth-graded multilayers, or so-called supermirrors, with platinum-carbon (Pt/C) layer pairs. It consists of four quadrant units assembled in an optical configuration with a diameter of 40 cm and a focal length of 8 m. Each quadrant is made of 510 pieces of coaxially and confocally aligned supermirrors that significantly enhance the sensitivity in an energy range of 20-40 keV. The configuration of the telescope is similar to the x-ray telescope onboard Astro-E, but with a longer focal length. The reflectivity of supermirrors is of the order of 40% in the energy range concerned at a grazing angle of 0.2 deg. The effective area of a fully assembled telescope is 50 cm2 at 30 keV. The angular resolution is 2.37 arc min at half-power diameter 8.0 keV. The field of view is 12.6 arc min in the hard-x-ray region, depending somewhat on x-ray energies. We discuss these characteristics, taking into account the figure errors of reflectors and their optical alignment in the telescope assembly. This hard-x-ray telescope is unanimously afforded in the International Focusing Optics Collaboration for muCrab Sensitivity balloon experiment.     

Atomic force microscopic studies on the structure of bovine femoral cortical bone at the collagen fibril-mineral level

The structure of cortical bone at the collagen-mineral level was investigated by means of atomic force microscopy. Surfaces of the specimens treated with collagenase and ethylenediaminetetraacetic acid (EDTA) were examined. Images of blob-like objects observed in intact specimen became clearly outlined after collagenase treatment; the sizes of the blob decreased, suggesting that each blob had been fragmented by the collagenase treatment. Following EDTA treatment of an intact specimen, an image of thread-like objects appeared; the thread was partly constructed by trains of blobs and the other parts of the threads had a periodic pattern along its longer axis. The period was almost equal to the collagen D-period of the Hodge–Petruska model, indicating that the threads are collagen fibrils and that the blobs are related to the mineral phase in bone. It was concluded that minerals were deposited on and along collagen fibrils. A decorated collagen fibril model for the spatial relationship between mineral and collagen fibril was proposed. According to our model, the mineral inside the collagen fibril is about one forth of the extrafibrillar mineral.