The distribution of palladium in a Pd-modified 4130 steel

The addition of palladium to a 4130 steel reduces its sensitivity to stress corrosion cracking and to hydrogen-induced cracking. The atom probe field-ion microscope has been used to study the microstructure and microchemistry of these palladium-modified 4130 steels with particular emphasis on the distribution of palladium between the various phases and internal interfaces. The palladium was found to segregate to the ferrite-ferrite lath boundaries to form a mono-atomically thick adsorbate layer. Palladium-manganese precipitates both at the lath boundaries and in the ferrite matrix were also detected. Most of the palladium was found to remain in solution in the ferrite.     

Development of sealing compositions with nanostructure iron-based fillers

The possibility of utilizing nanopowders of iron and Fe-Co-Ni produced bu a thermochemical method in the fabrication of sealing composition materials is investigated. It is established that such hermetic sealing composition materials function reliably under extremal conditions and guarantee elevated strength of adhesion to the surface of the metal and high corrosion and temperature stability. __________ Translated from Poroshkaya Metallurgiya, Nos. 3–4(448), pp. 112–117, March–April, 2006.     

Redox potential of a glass mass when using off-grade raw materials

The redox conditions for glass making are investigated on a working glass-melting furnace using molding sand. Data obtained from instrumental measurements of the ROP of the glass mass and reasons for destabilization of the technological process are presented. __________ Translated from Steklo i Keramika, No. 6, pp. 6–8, June, 2007.     

STABILITY OF COAL WATER PUEL

In this paper, a novel sensor is presented for monitoring the stability of a coal water fuel. This sensor utilizes a non-radioactive electromagnetic source, making it more attractive in comparison to other existing sensors. It utilizes the interaction between the electromagnetic waves and the CVF composition. Two of these interactions are selected, namely, the transmitted and reflected signal, and are used to give an indication on the stability of the CVF. The sensor measures the concentration changes or structural variations in the CVF. Calibration of the sensor is performed, for a given pipe/tube and a given CVF, by changing the concentration of the CVF and recording the transmitted and refelected signals as functions of concentration. These calibration curves are then stored in a microcomputer. At any instant of tine, the CVF stability is measured by comparing the sensor response to the stored curves. This sensor is easy to use and is readily adapted for automation. To demonstrate the applicability of the technique, the sensor response is measured and calibration curves are extracted and presented here. In this paper, four commonly used stability measurement techniques are also discusse     

A compact full MMIC module for Ku-band phase-lockedoscillators

A compact Ku-band phase-locked oscillator module has been developed in a full MMIC (monolithic microwave integrated circuit) configuration. The module includes an MMIC voltage-controlled oscillator, an analog frequency divider, and interstage amplifiers. The constituent monolithic chips are integrated in a very small single-package module and operate at the target frequencies without any external trimming or matching network. The oscillator is tuned more than 1 GHz with a constant output amplitude. The frequency-divided output is also obtained over the whole tuning range. Spurious output is not found at any frequency up to 22 GHz. In spite of the very low-Q factor of GaAs monolithic circuitry, the oscillator phase noise exhibited is less than -80 dBc/Hz, due to the high-gain, high-speed phase lock     

Gene Transfer Systems and Molecular Cloning in Group N Streptococci: A Review

Plasmid deoxyribonucleic acid of group N streptococci codes for a wide variety of important metabolic properties associated with dairy fermentations. The increasing knowledge of the genetics of these bacteria has created exciting possibilities for genetically constructing improved starter strains. A review of current literature is presented on the genetics of group N streptococci, especially the development and implications of gene transfer and molecular cloning systems for further genetic studies and for strain improvement. Functional properties of plasmid deoxyribonucleic acid and gene transfer systems, which include transduction, conjugation, transformation, and protoplast fusion, are reviewed and followed by a discussion of recent advances in gene cloning.     

SED88: a Pascal program for the analysis of sedimentation equilibrium data

Analytical ultracentrifugation is commonly used for the determination of molecular weights (sedimentation equilibrium) and sedimentation coefficients (sedimentation rate) of biological macromolecules in solution. A Turbo Pascal program for the analysis of sedimentation equilibrium centrifugation data produced by absorbance optical systems is described. The user may enter data from a scan of absorbance versus distance from the centre of rotation, via a graphics tablet (or ASCII file). This is subsequently manipulated to yield an apparent weight average molecular weight for the given sample. Plots of ln (absorbance) versus (radius2) may also be produced. The method described uses readily available computational equipment requiring only a graphics tablet in addition to an IBM PC compatible computer. This technique and the software developed have been used to investigate the molecular weight range of two International Humic Substances Society (IHSS) reference samples from the Suwannee River.     

Analysis of an interferometric optical fibre detection technique applied to silicon vibrating sensors

A simple and accurate analysis of a single-mode optical fibre interferometric displacement detection technique is resented. This analysis is in good agreement with experimental measurements, and shows that angular alignment between the fibre and the sensor is the most critical parameter.