Powers and speeds in electromechanical systems: Hybrid propulsion systems in cars

Mathematical expressions for determining the moments and speeds of the elements of planetary gearboxes are obtained. The possible modes of the operation of an internal combustion engine (ICE) combined with two electric machines are shown. The relation between powers of electric machines and the geometrical parameters of the planetary gear is achieved.     

Behavior of Cs, Np(V), Pu(IV), and U(VI) in pore water of bentonite

Sorption of Cs, Pu(IV), Np(V), and U(VI) with bentonite from solutions was studied. Physicochemical species of radionuclides in the liquid phase were determined, the sorption mechanisms were established, and the influence of bentonite colloids on the behavior of radionuclides was studied. It was shown that Cs is sorbed by the ion-exchange mechanism, whereas the sorption of actinides at pH > 5 is governed by the reaction with surface hydroxy groups of betonite, and at pH < 5 the competing processes are ion exchange and complex formation. Reduction of Np(V) and U(VI) to Np(IV) and U(IV) in the solution with Fe(II) compounds present in the system was proved by the extraction method. Various methods of separating the solid phase were used in studying the dependence of the distribution coefficients of Np and Pu on the ratio of pore water and bentonite; it was shown that Np and Pu are sorbed on bentonite colloids.     

Influence of fullerene on the rheological characteristics of melts of the polyamide composite forming the structure of a semi-interpenetrative polymer mesh

The time change in the melt viscosity of the polyamide composite forming at the final stage a polymer with the structure of a semi-interpenetrative polymer mesh has been investigated. To impregnate with the composite melt the carbon fiber for forming carbon-filled plastics, it is necessary to preserve the low viscosity of the melt for a long time. This is achieved by preliminary heat treatment of the composite and introduction of fullerene into it. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 78, No. 5, pp. 109–113, September–October, 2005.     

利用基于扫描相机的荧光寿命成像显微技术研究细胞周期

利用基于扫描相机的荧光寿命成像显微系统,以细胞周期为模型,研究转染绿色荧光蛋白的HeLa细胞的荧光寿命。结果表明,处于周期内不同进程的细胞的荧光寿命为2.50~3.00 ns。处于分裂期的细胞的荧光寿命在1 h内从2.86 ns下降到2.82 ns;在DNA合成前期的8 h内,荧光寿命从2.82 ns下降到2.78 ns。荧光寿命的差异反映了细胞周期中核浆内大分子浓度的变化,对了解细胞周期的分子机制有一定的意义。     

Lattice damage and secondary phase formation in Yttria stabilised zirconia implanted with Fe at different temperatures

In this paper we report on the lattice damage and nanocrystalline secondary phase formation in Fe implanted Yttria stabilised zirconia (YSZ) up to a peak concentration of 10%. The implantation temperature has been varied between room temperature and 1000 °C. Samples were characterized using Rutherford backscattering/channeling and X-ray diffraction. We observed that (1) YSZ remains partially crystalline even after Fe implantation at room temperature and the lattice damage can be partially recovered if implantation is performed at elevated temperatures; (2) crystalline bcc-Fe nanoparticles have formed and grown with increasing implantation temperature. The nanoscale Fe precipitates and the YSZ matrix have a crystallographic orientation relationship.     

FLIM of NAD(P)H in Lymphatic Nodes Resolves T-Cell Immune Response to the Tumor

Assessment of T-cell response to the tumor is important for diagnosis of the disease and monitoring of therapeutic efficacy. For this, new non-destructive label-free methods are required. Fluorescence lifetime imaging (FLIM) of metabolic coenzymes is a promising innovative technology for the assessment of the functional status of cells. The purpose of this work was to test whether FLIM can resolve metabolic alterations that accompany T-cell reactivation to the tumors. The study was carried out on C57Bl/6 FoxP3-EGFP mice bearing B16F0 melanoma. Autofluorescence of the immune cells in fresh lymphatic nodes (LNs) was investigated. It was found that fluorescence lifetime parameters of nicotinamide adenine dinucleotide (phosphate) NAD(P)H are sensitive to tumor development. Effector T-cells in the LNs displayed higher contribution of free NADH, the form associated with glycolysis, in all tumors and the presence of protein-bound NADPH, associated with biosynthetic processes, in the tumors of large size. Flow cytometry showed that the changes in the NADH fraction of the effector T-cells correlated with their activation, while changes in NADPH correlated with cell proliferation. In conclusion, FLIM of NAD(P)H in fresh lymphoid tissue is a powerful tool for assessing the immune response to tumor development.     

Iron Mobilization from Ferritin in Yeast Cell Lysate and Physiological Implications

Most in vitro iron mobilization studies from ferritin have been performed in aqueous buffered solutions using a variety of reducing substances. The kinetics of iron mobilization from ferritin in a medium that resembles the complex milieu of cells could dramatically differ from those in aqueous solutions, and to our knowledge, no such studies have been performed. Here, we have studied the kinetics of iron release from ferritin in fresh yeast cell lysates and examined the effect of cellular metabolites on this process. Our results show that iron release from ferritin in buffer is extremely slow compared to cell lysate under identical experimental conditions, suggesting that certain cellular metabolites present in yeast cell lysate facilitate the reductive release of ferric iron from the ferritin core. Using filtration membranes with different molecular weight cut-offs (3, 10, 30, 50, and 100 kDa), we demonstrate that a cellular component >50 kDa is implicated in the reductive release of iron. When the cell lysate was washed three times with buffer, or when NADPH was omitted from the solution, a dramatic decrease in iron mobilization rates was observed. The addition of physiological concentrations of free flavins, such as FMN, FAD, and riboflavin showed about a two-fold increase in the amount of released iron. Notably, all iron release kinetics occurred while the solution oxygen level was still high. Altogether, our results indicate that in addition to ferritin proteolysis, there exists an auxiliary iron reductive mechanism that involves long-range electron transfer reactions facilitated by the ferritin shell. The physiological implications of such iron reductive mechanisms are discussed.     

Effect of process factors and chemical composition of steels on the structure and properties of nickel-bearing diffusion coatings

The effect of the medium and regime of saturation and of the composition of the steel on the composition, structure, and properties of nickel, nickel-copper, and nickel-chromium diffusion coatings formed by selective transfer of the elements of the coating in a medium of low-melting liquid-metal solution is considered. The regular features of formation of nickel-bearing diffusion coatings on various steels are determined, which makes it possible to control the saturation process and form coatings with specified composition, structure, and properties. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 4, pp. 38–43, April, 2007.     

Calculation of suction capacity of centrifugal pumps

Information about cavitation characteristics of centrifugal pumps and critical cavitation conditions is given. Depending on the position of the leading edge, impellers are divided into three groups. The spatial lattice of the impeller is presented as a set of elementary lattices on the axisymmetric surfaces of a current of equal-velocity meridional flow. Equations have been derived from the determination of the cavitation margin and the equation of the energy in relative motion for the critical cavitation margin containing a cavitation coefficient referred to the impeller inlet. General equations have been obtained for the critical cavitaion coefficient of specific speed, which can be used to analyze the influence of geometric and operating conditions on the suction capacity of centrifugal impellers, which must be taken into account in designing them. The selection of the typical inlet diameter of the impeller has been substantiated and the critical cavitation coefficients of the elementary lattices have been found. An empirical equation, valid in the whole range of parameters encountered in practice, has been derived for the cavitation coefficient of type-3 impellers with a leading edge located roughly on the diameter of the impeller neck. An analytical equation, applicable for type-1 and-2 impellers, is given for the critical cavitation coefficient with empirical force coefficient values. A scheme for calculation of the suction capacity of such impellers is presented.