Apparatus for solidification of low- and medium-level wastes

Open-Type Joint-Stock Company "Sverdlovsk Scientific-Research Institute of Chemical Machinery Manufacture." Translated from Atomnyaya énergiya, Vol. 79, No. 6, pp. 429–433, December, 1995.     

An electrochemical study of zinc-containing epoxy coatings on mild steel

A comparative electrochemical study has been carried out between conventional zinc-rich and novel zinc-containing paints. To study the cathodic protection performance of these coatings an assessment method based on a galvanic couple was employed. Current and potential were monitored with immersion time in 3.5% NaCl. The zinc-rich paint offered cathodic protection for about 7 days compared with 40 days for the new paint. However, the steel coupled with the zinc-rich remained corrosion free for a further period. This was probably due to the inhibitive effect of zinc salts deposited at the cathode. Thereafter a reversal in polarity was obtained once rust formed. Thus it is concluded that established cathodic protection criteria cannot be solely used to assess the protection properties of zinc-containing paints. Electrochemical impedance spectroscopy was also used to study the state of the coating with time. Diffusion parameters indicated that the new paints were covered with a lesser amount of corrosion products.     

Effects of quantum statistics of phonons on the thermal conductivity of silicon and germanium nanoribbons

We present molecular dynamics simulation of phonon thermal conductivity of semiconductor nanoribbons with an account for phonon quantum statistics. In our semiquantum molecular dynamics simulation, dynamics of the system is described with the use of classical Newtonian equations of motion where the effect of phonon quantum statistics is introduced through random Langevin-like forces with a specific power spectral density (color noise). The color noise describes interaction of the molecular system with the thermostat. The thermal transport of silicon and germanium nanoribbons with atomically smooth (perfect) and rough (porous) edges are studied. We show that the existence of rough (porous) edges and the quantum statistics of phonon change drastically the low-temperature thermal conductivity of the nanoribbon in comparison with that of the perfect nanoribbon with atomically smooth edges and classical phonon dynamics and statistics. The rough-edge phonon scattering and weak anharmonicity of the considered lattice produce a weakly pronounced maximum of thermal conductivity of the nanoribbon at low temperature.     

Quasi-periodic regimes in the transition to unstable Lagrange dynamics

The appearance of a narrow band of quasi-periodic regimes between the regions of periodic (stable) and unstable (in the Lagrange sense) dynamics in the space of parameters of a dynamical system has been studied in the case of a model two-dimensional Hénon map. It is established that fast breakage of a quasi-periodic regime proceeds via nonlocal bifurcation, whereby an attractor touches a stable manifold of an immobile saddle point.     

A method for calibrating a strip resonator used in measurements of the complex permittivity of moist soils and grounds

A method for calibrating a microstrip microwave resonator used to measure the complex permittivity of moist soils and grounds is proposed. This method is based on the use of mixtures of a disperse solid substance and aqueous solutions of salts with known values of their complex permittivity. The resonator is composed of two segments of strip lines, the capacitive electromagnetic coupling between which occurs through a container with a moist soil sample. Sandy soil samples wetted by a sodium chloride solution were used as reference samples. The values of their complex permittivity were determined using the generalized refraction model and the reference data for the complex permittivity of a salt solution. A system of algebraic equations was set up, the solution to which, together with the formulas of the refraction model, allowed the complex permittivity of the test soil sample to be reconstructed from the measured values of the resonance frequency shifts and Q factor. The rms errors in measuring the real and imaginary parts of the complex permittivity, which varied over the ranges 4.79–11.03 and 0.39–3.15, were 0.21 and 0.03, respectively.     

Effectiveness of detection and estimation of position of heterogeneous image

The maximum likelihood algorithm of detecting heterogeneous image of lengthy in space object with unknown location against the space Gaussian white noise and the maximum likelihood algorithm for estimation of unknown coordinate of the image are considered. The detection and estimation characteristics are calculated accounting for anomal errors.     

Prevalence of male pattern hair loss in 18-49 year old men

BACKGROUND: Previous studies investigating the prevalence of male pattern hair loss (MPHL) typically used biased samples of men recruited from clinical populations which may limit generalizability of findings to broader populations. OBJECTIVE: To obtain an updated and improved estimate of the occurrence of MPHL in healthy men residing in the community. METHODS: Community-based sample of healthy men aged 18-49 years participated in a study investigating the effects of MPHL. Participants completed a brief questionnaire self reporting degree of hair loss, general health-related quality of life (HRQL) and hair-loss-specific measures. A trained observer also rated each participant using standardized classification for MPHL. RESULTS: The proportion of men with moderate to extensive hair loss (type III or greater) was 42%. The proportion of men with moderate to extensive hair loss increased with increasing age, ranging from 16% for men 18-29 years of age to 53% of men 40-49. Twelve percent of the men were classified as having predominantly frontal baldness (type A variants). CONCLUSIONS: MPHL, especially frontal baldness, may be more common than previously reported.