Photoelectric properties of ZnO/CuPc/Si structures

n-ZnO:Al/CuPc/n(p)-Si structures were formed using vacuum-evaporation deposition of copper phthalocyanine (CuPc) layers on the surface of n-and p-Si wafers with subsequent magnetron-sputtering deposition of ZnO:Al layers on the CuPc surface. It is shown that the structures obtained exhibit a high photosensitivity (～80 V/W at T=300 K) in the spectral range 1.65–3.3 eV. The rectification factor and photovoltaic effect in these structures are discussed in relation to the properties of silicon substrates. It is concluded that the contact of phthalocyanine with diamond-like semiconductors (e.g., silicon) are promising for application in wide-band high-efficiency photovoltaic converters.     

Investigation of the fatigue and short-term mechanical properties of 13% chromium steel and titanium alloys after welding or treatment with high-frequency currents as applied to steam-turbine blades

We present the results of a study on comparing the structural strength of rotor blades made of stainless 13% chromium steels for their design versions in which wear-resistant straps made of cast VZK stellite are soldered or welded on the blade inlet edges. It is shown that treatment of VT6 alloy with high-frequency currents increases the endurance limit of the zone subjected to strengthening and makes the alloy more resistant to erosion. The worn blades of a 48-T4 titanium alloy repaired with the use of welding technologies have operational characteristics at least as good as those of newly manufactured ones.     

Nanomaterial Shape Influence on Cell Behavior

Nanomaterials are proven to affect the biological activity of mammalian and microbial cells profoundly. Despite this fact, only surface chemistry, charge, and area are often linked to these phenomena. Moreover, most attention in this field is directed exclusively at nanomaterial cytotoxicity. At the same time, there is a large body of studies showing the influence of nanomaterials on cellular metabolism, proliferation, differentiation, reprogramming, gene transfer, and many other processes. Furthermore, it has been revealed that in all these cases, the shape of the nanomaterial plays a crucial role. In this paper, the mechanisms of nanomaterials shape control, approaches toward its synthesis, and the influence of nanomaterial shape on various biological activities of mammalian and microbial cells, such as proliferation, differentiation, and metabolism, as well as the prospects of this emerging field, are reviewed.     

Heterogeneous Manifestations of Epithelial–Mesenchymal Plasticity of Circulating Tumor Cells in Breast Cancer Patients

To date, there is indisputable evidence of significant CTC heterogeneity in carcinomas, in particular breast cancer. The heterogeneity of CTCs is manifested in the key characteristics of tumor cells related to metastatic progression – stemness and epithelial–mesenchymal (EMT) plasticity. It is still not clear what markers can characterize the phenomenon of EMT plasticity in the range from epithelial to mesenchymal phenotypes. In this article we examine the manifestations of EMT plasticity in the CTCs in breast cancer. The prospective study included 39 patients with invasive carcinoma of no special type. CTC phenotypes were determined by flow cytometry before any type of treatment. EMT features of CTC were assessed using antibodies against CD45, CD326 (EpCam), CD325 (N-cadherin), CK7, Snail, and Vimentin. Circulating tumor cells in breast cancer are characterized by pronounced heterogeneity of EMT manifestations. The results of the study indicate that the majority of heterogeneous CTC phenotypes (22 out of 24 detectable) exhibit epithelial–mesenchymal plasticity. The variability of EMT manifestations does not prevent intravasation. Co-expression of EpCAM and CK7, regardless of the variant of co-expression of Snail, N-cadherin, and Vimentin, are associated with a low number of CTCs. Intrapersonal heterogeneity is manifested by the detection of several CTC phenotypes in each patient. Interpersonal heterogeneity is manifested by various combinations of CTC phenotypes in patients (from 1 to 17 phenotypes).     

The Influence of Adsorption Processes on Structural and Catalytic Properties of Nickel

Protection of Metals and Physical Chemistry of Surfaces - The effect of the conditions for carrying out the reaction of liquid-phase hydrogenation of the nitro group on a bulk nickel catalyst in a...     

Experimental Investigation of Underground Mining of High-Grade Quarts in Kyshtym Mine

Application of a geotechnology used in high-grade quarts mining in Kyshtym Mine is studied. The room-and-pillar method is trialed, and the actual mining performance is assessed. The potential benefits of the geotechnology are evaluated. The air-decoupled charges without inert filler are designed and tested for fan pattern blasting. Size distribution of broken ore is estimated, and optimal parameters of blasting and powder factor are determined. The feasibility of quartz loss reduction by 3 times owing to extraction of useful mineral from pillars and due to decreased yield of overground quartz by 25–40% is proved.     

Thermodynamic Calculation of the Characteristics of Metal Thermionic Emission

The thermodynamic equilibria of the “Fermi–Dirac gas–Maxwell gas–Boltzmann gas” and “metal–saturated vapor” systems are considered (with allowance for charged particles). It is shown that the work function of a metal at 0 K is equal to the Mulliken electronegativity of its atoms. For the latter case, it is proposed to take into account the relationship between the work-function thermal coefficient and the thermodynamic functions of positive and negative metal ions.     

Microgravity Investigation of Capillary Driven Imbibition

The goal of the present paper is to investigate the capillary driven filtration in porous media under microgravity conditions. New mathematical model that allows taking into account the blurring of the front due to the instability of the displacement that is developing at the front is proposed. The constants in the mathematical model were selected on the basis of the experimental data on imbibition into unsaturated porous media under microgravity conditions. The flow under the action of a combination of capillary forces and a constant pressure drop or a constant flux is considered. The effect of capillary forces and the type of wettability of the medium on the displacement process is studied. A criterion in which case the capillary effects are insignificant and can be neglected is established.     

New C–Si–Mn–Cr–V–Mo powder wires for roller surfacing

Laboratory data indicate the positive effects of introducing fluorocarbon and nickel in 25Kh5FMS steel powder wire for the surfacing of rollers. In particular, the replacement of amorphous carbon by a material containing fluorocarbon lowers the content of nonmetallic inclusions in the applied layer, while introducing nickel in the powder wire reduces the austenite grain size and ensures the formation of small carbide particles. That increases the thermal stability of the applied layer. Increase in the carbon equivalent of the 25Kh5FMS powder wire boosts the hardness of the applied metal layer.