Assessment of bone structure and acoustic impedance in C3H and BL6 mice using high resolution scanning acoustic microscopy

Two hundred-MHz time-resolved scanning acoustic microscopy was applied for the investigation of acoustic and structural bone properties of mice from two inbred strains. Transverse sections of femur taken from 5 C57BL/6J@Ico and 5 C3H/HeJ@Ico mice were explored. Both strains had the same bone diameter, but the C3H/HeJ@Ico mice had greater cortical thickness, smaller cancellous diameter, and greater acoustic impedance values than C57BL/6J@Ico mice. The strong differences in the measured acoustic impedances among the two inbred strains indicate that the impedance is a good parameter to detect genetic variations of the skeletal phenotype in small animal models.     

Significance of the fragmentation region in ultrarelativistic heavy-ion collisions

We present measurements of the pseudorapidity distribution of primary charged particles produced in Au+Au collisions at three energies, sqrt[s(NN)]=19.6, 130, and 200 GeV, for a range of collision centrali-ties. The distribution narrows for more central collisions and excess particles are produced at high pseudorapidity in peripheral collisions. For a given centrality, however, the distributions are found to scale with energy according to the "limiting fragmentation" hypothesis. The universal fragmentation region described by this scaling grows in pseudorapidity with increasing collision energy, extending well away from the beam rapidity and covering more than half of the pseudorapidity range over which particles are produced. This approach to a universal limiting curve appears to be a dominant feature of the pseudorapidity distribution and therefore of the total particle production in these collisions.     

ERD studies of D-ion depth distributions after implantation into some pure metals and alloys

This paper presents a report on experimental results of depth distributions of deuterium ions implanted with 25 keV energy at a fluence interval of (1.2–2.3) × 10²² m⁻² into samples of pure metals (Cu, Ti, Zr, V, Pd) and diluted Pd alloys (Pd-Ag, Pd-Pt, Pd-Ru, Pd-Rh). The post-treatment depth distributions of deuterium and hydrogen atoms were measured within a few hours after implantation with the use of elastic recoil detection (ERD) analysis. After three months the measurements were repeated. The comparison of the obtained results in both series of studies allowed us to make an important observation of the desorption rates of implanted deuterium atoms from pure metals and diluted Pd alloys. The maximum measured concentrations of deuterium atoms in pure Zr and Ti foils with relatively small desorption rate of deuterium atoms within three months after implantation were observed. Also a very high spreading of deuterium atom distributions was observed in all the measured pure metals and alloys. It can be explained by the large diffusion coefficients of deuterium and extremely fast kinetics.     

Chelating Polymers. III. Chelating Monomers and Polymers from s-Triazinyl Substituted Hydrazinoacetic Acids

The model chelating compounds β-[2,4-bis(dimethylamino)-s-triazin-6-yl] hydrazinoacetic acid, β-[2,4-bis(dimethylaniino)-s-triazind-yl] hydrazino-N, N-diacetic acid, 2,4-bis(dimethylamino)-s-triazin-6-yl-aminoacetic acid, and 2,4-bis(dimethylamino)-s-triazin-6-yl-iminodiacetic acid have been synthesized and characterized by composition analysis, infrared spectroscopy, and potentiometric titration data. The copper(II), nickel(II), cobalt(II), zinc(II), magnesium(II), and palladium(II) complexes of the first two model compounds, and the copper, nickel, cobalt, and zinc complexes of the third and fourth model compounds have been prepared. The infrared absorption spectra of the model compounds and their complexes were recorded for the range 3800 to 600 cm^?1, and the assignment of pertinent bands was made by comparison with reported infrared correlations. In those cases where applicable, shifts in the NH stretching vibration and carboxylate stretching vibration frequencies of the metal complexes were compared to those of the proper references and used as an indication of possible chelation effects in the metal complexes.

The aldehyde-reactable β-[2,4-diarnino-s-triazin-6-y1] hydrazinoacetic acid was also prepared and characterized; its polymers were prepared by the reaction of both the free ligand and its copper(II) complex with formaldehyde. Qualitative studies on the reaction of these polymers with metal ions and on the ease of metal ion elution from the polymers indicate that t h is a promising chelating polymer system.     

Capacity and kinetic measurements of methane and nitrogen adsorption on H+-mordenite at 243–303 K and pressures to 900 kPa using a dynamic column breakthrough apparatus

A dynamic column breakthrough (DCB) apparatus was used to measure the capacity and kinetics of CH₄ and N₂ adsorption on zeolite H⁺-mordenite at temperatures in the range 243.8–302.9 K and pressures up to 903 kPa. Equilibrium adsorption capacities of pure CH₄ and pure N₂ were determined by these dynamic experiments and Langmuir isotherm models were regressed to these pure fluid data over the ranges of temperature and pressure measured. A linear driving force-based model of adsorption in a fixed bed was developed to extract the mass transfer coefficients (MTCs) for CH₄ and N₂ from the pure gas experimental data. The MTCs determined from single adsorbate experiments were used to successfully predict the component breakthroughs for experiments with equimolar CH₄ + N₂ gas mixtures in the DCB apparatus. The MTC of CH₄ on H⁺-mordenite at 902 kPa was 0.013 s^?1 at 302.9 K and 0.004 s^?1 at 243.6 K. The MTC of N₂ on H⁺-mordenite at 902 kPa was 0.011 s^?1 at 302.9 K and 0.005 s^?1 at 243.5 K. The values of the MTCs measured for each gas at a constant feed gas flow rate were observed to increase in a linear trend with the inverse of pressure. However, the apparent MTCs obtained at the lowest pressures studied (≈105 kPa) were systematically below this linear trend, because of the slightly longer residence time of helium in the mass spectrometer used to monitor effluent composition. Nevertheless, the pure fluid dynamic breakthrough data at these lowest pressures could still be reasonably well described using MTC values estimated from the linear trend. Furthermore, the results of dynamic breakthrough experiments with mixtures were all reliably predicted using the capacity and MTC correlations developed for the pure fluids.