Theoretical Determination of the Parameters of Arterial Blood Pressure

The problem of determining arterial blood pressure by a noninvasive method and without using an external pressure source is considered. Physical and mathematical models of the determination of the parameters of arterial pressure are proposed.     

Mechanochemical Synthesis of Mo-Doped Nickel Aluminides

The structure and thermal stability of Mo-doped Ni–Al intermetallic phases prepared by mechanical alloying were studied by x-ray diffraction and differential scanning calorimetry. The results demonstrate that mechanical processing of 50Ni + 45Al + 5Mo and 45Ni + 5Mo + 50Al powder mixtures yields nonstoichiometric aluminides and that a part of the Mo remains unreacted. The Mo introduced instead of Ni occupies some Ni sites in the structure of the forming aluminide, and this distribution persists during subsequent heating to 700°C. When Mo partially replaces Al, the Mo atoms also occupy some Ni sites, but subsequent heating to 700°C drives them to Al sites.     

Conceptual approach to introduction of information technology into the field of simulation

We consider results of research by the faculty for design and production of radio equipment at Penza State University; the research was concerned with development of methods, models, algorithms, and software packages for investigating complex mechanical systems, technologies, and simulation of physical processes. Translated from Izmeritel'naya Tekhnika, No. 5, pp. 7–11, May, 1999.     

Dependence of the properties of Cd1−x ZnxTe crystals on the type of intrinsic point defect formed by oxygen

Coordinated investigations of cathodoluminescence spectra, microstructure, specific resistance and presence of oxygen in Cd_1−x Zn_xTe crystals are used to identify how the electrical properties and degree of perfection of the crystal lattice of these materials are affected by the form in which oxygen is present as an intrinsic point defect. It is found that oxygen, which is the main background impurity in Cd_1−x Zn_xTe, forms different types of point defects at different positions in the lattice, depending on the ratio [Cd]/[Zn]. The optimum composition for making detectors of ionizing radiation, for which the crystal resistance is highest, is Cd_0.77Zn_0.23Te. Fiz. Tekh. Poluprovodn. 33, 569–573 (May 1999)     

Entropy of glass transition and polymorphism

An analysis is made of the change in entropy in the glass transition process. It is shown that although the entropy of glass transition is less than that of melting, it is no more than two orders of magnitude smaller. The main results are obtained without using the conditions of local equilibrium, which are not satisfied for the glassy state. Pis’ma Zh. Tekh. Fiz. 24, 12–17 (February 12, 1998)     

Direct and reverse elastic aftereffects of spring ribbon from nitrogen-bearing steel Kh21G10N7MBF

Direct and reverse elastic aftereffects in corrosion-resistant nitrogen-bearing steel Kh21G10N7MBF (0.5% N) are considered depending on the preliminary heat treatment (quenching + deformation + aging) and on the temperature and time conditions of the occurrence of the direct and reverse elastic aftereffects. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 1, pp. 8–11, January, 2006.     

ZnSe<Cu> Luminescence at High Doping Levels

ZnSe was doped with Cu via thermal diffusion from Cu foil in the course of chemical vapor deposition. The Cu distribution over the deposit was studied, and the Cu solubility in ZnSe was determined as a function of temperature. Copper was shown to prevent oxygen incorporation from the gas phase. The microstructure and homogeneity of ZnSe were studied by scanning electron microscopy. The cathodoluminescence (CL) spectra were measured on fracture surfaces in order to elucidate the origin of the Cu-related emission centers. Heavy doping with Cu was shown to gives rise to a long-wavelength CL band, which shifts from 525 to 550 nm as the temperature is raised from 80 to 300 K. The associated changes in oxygen-related self-activated luminescence were correlated with the Cu and O concentrations. To gain more detailed insight into the origin of the green Cu-related emission in p-type ZnSe, we examined its photoexcitation spectrum, temperature-dependent peak position, quenching, and variation with excitation intensity. The conclusion is drawn that the longer wavelength CL bands are due to electron transitions from the Zn_i ^·· donor level to the impurity band. The CL spectrum of heavily doped ZnSe shows no emissions between 800 and 1400 nm, related to the V _Se and V _Zn vacancies.     

Neutron spectrum of248Cm spontaneous fission

V. G. Khlopin Radium Institute. Translated from Atomnaya Énergiya, Vol. 71, No. 6, pp. 566–568, December, 1991.     

Investigation of Concretions from the Baltic Sea

The composition and specific features of the dissolution of iron manganese concretions from the Baltic Sea are investigated using an echelle spectrometer and atomic absorption spectrometry. The concretion samples used in the analysis are treated in diluted solutions of hydrochloric and nitric acids with additives of hydrogen peroxide. The as-analyzed ratio Mn : Fe in the samples studied is equal to 1.7, which is an important characteristic of the ratio of d elements involved in concretions from the Baltic Sea. The results of the investigations performed can be used to develop more efficient methods for selective extraction of manganese from similar concretions and to determine the isotope content in noble gases of ancient artifact origin that survive in concretions of the World Ocean.