The Influence of the Composition and Particle Size of Starting Titanium Hydride Powders on the Consolidation of Titanium Under Sintering

Powder Metallurgy and Metal Ceramics - The influence of the starting powder composition, grinding conditions, and sintering temperature on the compaction mechanism under sintering and the porosity...     

Residual stresses in centrifugally-cast iron pipe

Metal Science and Heat Treatment -     

Crystallization of chemically vapor deposited molybdenum and mixed tungsten/molybdenum oxide films for electrochromic application

The paper deals with investigation of Mo oxide and mixed W/Mo oxide films showing high electrochromic performance. Films are deposited on Si and conductive glass substrates using pyrolytical decomposition at 200 °C of Mo and W hexacarbonyls in Ar/O₂ atmosphere. The study is focused on structural transformation of the films in dependence on deposition and annealing process parameters. In case of conductive glass substrate (typical for electrochromic devices), the crystallization process in Mo oxide films is almost completed at 400 °C forming triclinic MoO_2.89 and orthorhombic MoO₃ crystalline phases. The structure of mixed W/Mo oxide films is triclinic crystalline phase of tungsten oxide matrix with Mo atoms as substitutes. Discussed are, as well, differences in the crystallization process for the same films, when the substrate is Si. All the films show electrochromic effect, the mixed W/Mo oxide films expressing stronger electrochromic effect with superior color efficiency and optical modulation.     

Population migration and the epidemic situation of parasitoses in Belgorod Province]

Paper summarized a concise evaluation of short wounds according to the Red Cross Classification published in Geneva. It is supposed to attract the forensic physician's attention due to informative purpose.     

Osmolality and potassium cause alterations in the volume of glomerulosa cells

Alterations in extracellular osmolality have a powerful inverse effect on aldosterone secretion and potassium- and angiotensin-stimulated aldosterone secretion. Whether alterations in extracellular osmolality produced sustained changes in cell volume that may contribute to the regulation of aldosterone secretion is not known. Using dispersed bovine glomerulosa cells grown in primary culture, the effect of alterations in osmolality on cell volume, measured by the distribution of [14C]urea and [3H]inulin and videometric analysis of the surface area of glomerulosa cells, was determined. Alterations in osmolality had an inverse effect on cell volume and surface area. Changes in cell volume induced by exposure to anisotonic medium were 52% greater (P > 0.02) than that predicted by the changes in osmolality. Increases in potassium concentration also caused sustained (1-h) concentration-dependent increases in cell volume and surface area. Angiotensin-II did not increase glomerulosa cell volume, but did produce a small dose-dependent transient increase in cell surface area. The results demonstrate that alterations in osmolality do cause sustained changes in cell volume, and thus, membrane stretch could be an important part of the cellular mechanism responsible for causing osmolality-induced changes in the cytosolic calcium concentration and subsequent alterations in aldosterone secretion. Alterations in membrane stretch may also be an important component of potassium-induced, but not angiotensin II-induced, aldosterone secretion.     

Estimating microdamage tendencies from standard uniaxial stretching tests

Test results for several steels are presented on the tendency to microdamage in relation to the composition and structural state. A method is proposed that incorporates the tendency to microdamage in relation to the structural state of the main metal and of welded joints.     

Electrodeposition of metal molybdenum from electrolytes containing hydrofluoric acid

The effect of hydrofluoric acid on the cathodic reduction of molybdate ions is studied. It is shown that the mechanism of this process is determined by the acid concentration: in a concentration range below 25 g/l the intermediate products of molybdate-ion reduction, namely, black or colored deposits containing molybdenum with the average valence of 3.6–4 are formed on the cathode. For the concentration above 50 g/l, molybdate ions are completely reduced and form at the cathode dense light metallic coatings with a thickness of 3–5 μm and good adhesion to the substrate. The addition of hydrofluoric acid prevents polymerization of molybdate ions. Original Russian Text ? N.D. Ivanova, S.V. Ivanov, E.I. Boldyrev, O.A. Stadnik, 2006, published in Zashchita Metallov, 2006, Vol. 42, No. 4, pp. 388–392.     

Stabilized Zirconia Nanoceramics Prepared by Magnetic Pulsed Compaction of Nanosized Powders

Ceramic materials with a fine structure are synthesized from zirconia-based nanopowders through magnetic pulsed compaction and subsequent sintering under different temperature-time conditions. The kinetics of crystallite growth and polymorphic phase transformations are analyzed. Unstabilized zirconia ceramic materials with a density of 96% and a crystallite size of 50 nm are prepared. It is found that, in the case when the ceramic materials with a cubic or tetragonal yttrium-stabilized zirconia (YSZ) matrix are synthesized with small additives of alumina nanopowders, the temperatures of active shrinkage and the polymorphic transformation γ-Al₂O₃ → α-Al₂O₃ are shifted to the high-temperature range, the density and microhardness of the final ceramics slightly decrease, and the size of α -Al₂O₃ crystallites does not exceed 100 nm. It is also established that the alumina additives have no noticeable effect on the growth of crystallites of the YSZ matrixOriginal Russian Text Copyright © 2005 by Fizika i Khimiya Stekla, Ivanov, Khrustov, Paranin, Medvedev, Shtol’ts, Ivanova, Nozdrin.     

Electrochemical behavior of copper and cobalt in post-etch cleaning solutions

Cleaning is one of the key steps of the integration of self aligned barriers (SAB) in microelectronic devices for 32 nm technology and below. It is hence important to investigate the impact of different cleaning solutions on the metallic components of SAB, mainly in which concerns their surface stability. In this sense, the electrochemical behavior of copper and cobalt was studied under potentiodynamic conditions in different aqueous solutions of glycolic acid (GA) with and without benzotriazole (BTA) inhibitor.It has been observed that the presence of glycolic acid induces a monotonic increase of copper corrosion and a slight decrease in the case of cobalt. The cobalt dissolution remains nonetheless very active and is shown to be governed by oxygen reduction reaction. The addition of BTA, a well-known corrosion inhibitor for copper has shown to be also effective in the case of Co surfaces, with a ca 15-fold reduction of the intrinsic Co corrosion current density.The possibility of galvanic coupling between both metals, supposed to enhance the Co dissolution, has also been qualitatively investigated and seems not to be a determinant factor in these conditions.