The advantage of the osmium conductive metal coating for the detection of the colloidal gold-conjugated antibody by SEM

For the detection of the colloidal gold-conjugated antibody by scanning electron microscopy, the comparison between the secondary and the back-scattered electron images is necessary. After the various durations of osmium conductive metal coatings, enlargements of the diameters of the antibodies were observed. The thick coating reduced the contrast of the backscattered electron images. By the optimal thickness of the coating, the secondary electron image showed a minimum reduction in the resolution, and the backscattered electron image showed not only the gold particles with high contrast, but also the outline of the basic morphology.     

Anisotropic electrical conduction in relation to the stacking disorder in graphite

The in-plane and c-axis conduction behaviors of kish graphite and of hot-worked pyrolytic graphite are discussed in relation to their structural perfection, special interest being focused onto the stacking fault disorder which appears in the form of extended basal dislocation ribbons. Analysis of the two-dimensional magneto-conductivity indicates that the carrier density of faulted specimens increases slowly with temperature (T) even below the degeneracy point of the carrier system, whereas the unfaulted ones do not. The c-axis resistivity (?_c) has been found to decrease with diminishing stacking disorder for a well-defined specimen group not containing such irregularities as microcracks. This verifies the applicability of the band model to the intrinsic ?_c's, in connection with the success of Ono's theory accounting for the wide-range scattering of past data. The discrepancy still remaining between the theoretical and experimental ?_c vs T relationships; as well as the increase of the in-plane conduction carriers density with temperature, seems to be removed by assuming thermal liberation of the localized Tamm-state electrons from the stacking fault planes.     

Blade Fabrication Process for Titanium Matrix Composites

Continuous fiber reinforced titanium matrix composites (TMC) are attractive as one of the potential structural materials for aerospace applications, because of their high specific strength and stiffness. However, TMC parts are not yet put into practical use due to their limited damage tolerance and an enormous production cost resulting from process limitation requiring preliminary forming and elaborate tooling for consolidation. In order to reduce the production cost, superplastic TMC sheets (SiC/Ti-4.5Al-3V-2Mo-2Fe) were developed, and deformation properties, and cavitation behavior were investigated. The blade-shaped model was formed successfully out of the newly developed TMC sheet by means of Argon-gas-pressure forming technique. However, in order to reduce the defects that were observed in fiber/matrix interface of the deformed TMC, the tensile flow stresses in TMC sheet during deformation should be minimized. In this study a diaphragm forming method, whereby a TMC sheet is forced against the form tool surface by pressure acting on a driving sheet, was adopted to reduce the tensile stress generated in TMC sheet during superplastic forming of blade-shaped models. As a result, no defects were observed by an optical microscope in the TMC deformed by diaphragm forming method. Diffusion bonding techniques to attach the root blocks to the deformed TMC sheet and the reduction of the blade-fabrication cost are also discussed.     

Dielectric properties of sintered materials prepared from glass-ZrO2-SrTiO3 mixtures

(Ca,Sr,Ba)O-Al₂O₃-SiO₂-TiO₂ glass powder was mixed with 6.7 mol % ZrO₂ and 0–11.96 mol % SrTiO₃. The mixtures were sintered at 850 °C, 900 °C or 950 °C. Most of the glass phase changed to crystalline phases of (Ca,Sr,Ba)₂TiSi₂O₆TS, (Ca,Sr,Ba)Si₂O₆AS, ZrO₂ and SrTiO₃ during sintering. The dielectric properties of samples sintered at 900 °C were measured at 1 MHz using silver electrodes. With increasing SrTiO₃ content, the dielectric constant increased from 12 to 19 and the temperature coefficient of dielectric constant, TCD, changed from -30 ppm ^C^-1 to -400ppm^C^-1. Using mixture equations, dielectric constants and TCD values were estimated for the samples and these values were compared with experimental results.     

The influence of impurity-doping on temperature dependence of dislocation-ribbon width in graphite

By means of an electron microscope, the width of dislocation ribbons in a stress-annealed pyrolytic graphite and doped with iodine chloride (ICl) and bromine was investigated as a function of temperature in the range 100°K to 300°K. The impurity content amounted to 1·1 at % for ICl and 1·6 at % for bromine. Through measurements of the ribbons widths W in steps of 20°K, the average temperature coefficients $\text{1}\text{W}\text{·}\text{dW}\text{?dT}$ were found to be 5 × 10^?4, 3 × 10^?4 and 1 × 10^?4°K^?1, for the original, ICl-doped and bromine-doped material respectively; this shows that the temperature dependence of the ribbon width in graphite is appreciably decreased by the presence of halogen impurities. The phenomenon is quantitatively analyzed in terms of the chemical interaction mechanism between stacking faults and impurities. A discussion of the viscous drag function of impurities for dislocations in relation to the internal friction is included.     

Mobile teletext reception using signal processing in frequencydomain

An experimental study of mobile teletext reception is described. Teletext in Japan is a broadband signal with 5.73 Mb/s; therefore, multipath interference is a serious problem in mobile reception, and it is impossible to obtain the teletext correctly by conventional methods. A multipath reduction technique using signal processing in the frequency domain is developed. In this technique, an original chirp signal is used for reference to identify the radio propagation path. In field trials, the delay profile was precisely obtained, and the bit error rate was reduced. The error correction capability was tested in a computer simulation     

In situ investigation of chemical reactions between BaCO3 and anatase or rutile TiO2

The most popular method of preparation of BaTiO₃, which is one of the most widely used ferroelectric materials for multi-layered ceramic capacitors, is the solid-state reaction process between powdered barium carbonate (BaCO₃) and titanium dioxide (TiO₂) at high temperature. The influence of the different structural forms of TiO₂ used (i.e. rutile or anatase) on the reaction process and on the crystallinity of synthesized BaTiO₃ is only known on empirical grounds. The solid-state reaction between BaCO₃ and either TiO₂ anatase or TiO₂ rutile was investigated by in situ by X-ray diffraction and micro Raman scattering measurements. The formation of both barium oxycarbonate BaO_x(CO₃)_1−x and of a very small amount of Ba₂TiO₄ were detected in the samples as intermediate phase before the formation of BaTiO₃. The Raman spectra of the final product obtained in each case is essentially the tetragonal BaTiO₃ containing small amounts of non-reacting BaCO₃ and of hexagonal barium titanate. The tetragonality of the final product was found to be slightly better for BaTiO₃ synthesized from rutile and BaCO₃ than from anatase and BaCO₃, whereas the average particle sizes are essentially the same for both products.     

Anomalous heat capacity and phase transition of graphite-ICl intercalation compounds

By means of alternating current calorimetry and X-ray diffraction, a study has been made of the phase transition behavior of graphite-ICl intercalation compounds slowly heated from 290 to 340 K. The heat capacity vs. temperature plots exhibit λ-type anomalies at 305 ± 1, 312 ± 1 and 315 ± 1 K. X-ray diffraction indicates that abrupt expansion of the c-axis occurs also near 305, 311 and 315 K, when the first-to-second, second-to-third and third-to-fourth or fifth stage changes, respectively, occurring in the subsequent temperature ranges are initiated. Each λ-type anomaly seems to represent the two-dimensional order-disorder transition of ICl layers taking place prior to the stage change. In order to account for the repetition of the order-disorder transition at different temperatures, it is proposed that deintercalation and restabilization of ICl layers occur alternatively during the slowly proceeding stage changes.