Thermal and thermoelastic properties of fast extrusion furnace (FEF) carbon black loaded SBR vulcanizates

The effect of FEF carbon black as filler on the thermal capacity c, diffusivity a, and thermal conductivity λ, of styrene butadiene rubber (SBR) composites in the temperature range 300–420 K was studied. The filler strongly increases the thermal diffusivity, whilst strongly decreasing the thermal capacity and the thermal conductivity (except at high FEF content ≥80 phr). The influence of the filler on the thermoelastic behaviour of the same composites was also investigated. It was found that the thermoelastic temperature change (ΔT) increased with carbon black concentration as well as the entropy change per unit extension.     

An experimental investigation of thick-sample effects in the measurement of directional-hemispherical transmittance of advanced glazing materials

Samples that are thick with respect to the measuring apparatus can pose problems in the measurement of directional-hemispherical transmittance. Due to the lateral displacement of light that these samples induce, traditional small-beam techniques are often no longer applicable. Broad-area irradiation offers a solution to these problems, but, in practice, imperfections in the extent and the uniformity of the irradiation can create errors. This paper reports measurement of the “detector-integrated inscattering function”, which describes the lateral displacement of light, for a number of thick samples over a range of incidence angles. This function is used to determine the minimum area that must be irradiated for an accurate broad-area irradiation transmittance measurement. The errors caused by transverse non-uniformities in the irradiance distributions produced by a state-of-the-art broad-area irradiation spectrophotometer are also reported. Errors caused by transverse irradiation non-uniformities are estimated, and transmittance measurements made with small-area and broad-area irradiation are compared. It is shown that in most cases small-area irradiation transmittance measurements underestimate the transmittance of thick samples due to outscattering, and that broad-area irradiation measurements using state-of-the-art irradiation optics can contain large errors of up to 20%, due to irradiance non-uniformities, particularly at large angles of incidence.     

FLOW OF SAND-WATER MIXTURES AT VELOCITIES BELOW THE DEPOSITION CONDITION

An experimental study of sand-water flow in a horizontal pipeline has been conducted for the regime in which a stationary deposit was present. The particle diameter ranged between 0.2 mm and 0.01 mm and the particles were not flocculated. Axial pressure gradients and delivered concentrations were measured as functions of mean velocity and in-situ concentration.

A three layer model was found to be useful to predict the pipeline behavior at all but the lowest velocities. The Meyer-Peter sediment transport equation was satisfactory for very low velocities with the larger particles.     

Shock-Wave Synthesis of Micron-Size Diamond From Fullerites

Fullerite powders in copper powder matrix were subjected to shock loading in the pressure range of 20-40 GPa. Diamond, nonreacted fee C₆₀ and graphite were detected in all analyzed specimens. The dimensions of synthesized diamond crystallites were up to 6 micron.     

Fourier-transform infrared conformational study of bovine insulin in surfactant solutions

BACKGROUND: bcl-2 protein is an oncoprotein encoded by a protooncogene bcl-2 which is thought to be a key gene for the regulation of cell life and death. bcl-2 protein has been reported to be expressed in a subset of prostate cancers, and its biological role in this disease has not yet been elucidated. This present study focused on the cell cycle analysis of bcl-2 immunoreactivity in prostate tumor samples and correlated findings with the prognosis of the patients. METHODS: Archival tissues from 37 prostate cancers were submitted for immunohistochemistry and DNA analysis via flow cytometry. All tissues were obtained before the patients received any treatment. Immunohistochemistry was performed using streptavidin biotin procedures, and DNA flow cytometry was done by a combination of two methods. RESULTS: Fourteen of 37 prostate cancers (38%) exhibited bcl-2 immunoreactivity. bcl-2 positive prostate cancers significantly correlated with DNA aneuploidy and higher proliferation indices, but not with histological differentiation. Clinically, there was a poorer prognosis for patients with bcl-2 positive prostate cancer. CONCLUSIONS: Our data indicates that bcl-2 protein expression in prostate cancer is associated with cell proliferation and may serve as a predictive factor for the prognosis of prostate cancer.     

High-speed InGaP/GaAs HBTs with a strained InxGa1-xAs base

A self-aligned InGaP/GaAs heterojunction bipolar transistor with a compositionally graded In_xGa_1-xAs base has been demonstrated with f_T=83 GHz and f_max=197 GHz. To our knowledge, these results are the highest reported for both parameters in InGaP/GaAs HBT's. The graded base, which improves electron transport through the base, results in a DC current gain and a cutoff frequency which are 100% and 20% higher, respectively, than that achieved by an identical device with a nongraded base. The high f_max results from a heavily doped base, self-aligned base contacts, and a self-aligned collector etch. These results demonstrate the applicability of InGaP/GaAs HBT's in high-speed microwave applications     

Psychological stress symptoms before and after autologous bone marrow transplantation in patients with solid tumors

This study sought to examine patterns of changes of psychological stress symptoms in autologous bone marrow transplantation (ABMT) recipients. Forty-nine patients affected by solid tumors were assessed using the Symptom Questionnaire on admission to hospital (before high-dose chemotherapy and ABMT) and before discharge. Symptoms of anxiety and anger tended to decrease and relaxation of improve over time. Nevertheless, on admission to hospital 30-50% of the patients reported severe to moderate symptoms of anxiety and depression. Before discharge, the prevalence was still high (20-35%). The implications of these findings are discussed in terms of the need to monitor the evolution of emotional functioning of cancer patients undergoing ABMT.