Distribution of Magnetic Flux in a Ferromagnetic Material in the Presence of a Nonferromagnetic Gap in the Composite Circuit

Russian Journal of Nondestructive Testing - Comparative analysis of the distribution of magnetic-induction vector components over the volume of a bulk homogeneous sample of 40Kh steel has been...     

Mechatronic Motorized Spindle with Hydrostatic Bearings and a Piezohydraulic Generator of Resonant Axial Microoscillations

A mechatronic motorized spindle with hydrostatic bearings and a contact-free piezohydraulic generator of resonant axial spindle microoscillations is proposed. The boundary problem is solved for a nonsteady Reynolds equation in laminar motion, with no cavitation of the working fluid. On that basis, analytical formulas are derived for the dynamic-pressure distribution of the working fluid and the dynamic axial force created in the gap of the piezohydraulic generator.     

Role of Co in formation of Ni-Ti clusters in maraging stainless steel

The effect of Co addition on the formation of Ni-Ti clusters in maraging stainless steel was studied by three dimensional atom probe (3DAP) and first-principles calculation. The cluster analysis based on the maximum separation approach showed an increase in size but a decrease in density of Ni-Ti clusters with increasing the Co content. The first-principles calculation indicated weaker Co-Ni (Co-Ti) interactions than Co-Ti (Fe-Ti) interactions, which should be the essential reason for the change of distribution characteristics of Ni-Ti clusters in bcc Fe caused by Co addition.     

Multicellular Tumor Spheroids (MCTS) as a 3D In Vitro Evaluation Tool of Nanoparticles

Multicellular tumor spheroid models (MCTS) are often coined as 3D in vitro models that can mimic the microenvironment of tissues. MCTS have gained increasing interest in the nano‐biotechnology field as they can provide easily accessible information on the performance of nanoparticles without using animal models. Considering that many countries have put restrictions on animals testing, which will only tighten in the future as seen by the recent developments in the Netherlands, 3D models will become an even more valuable tool. Here, an overview on MCTS is provided, focusing on their use in cancer research as most nanoparticles are tested in MCTS for treatment of primary tumors. Thereafter, various types of nanoparticles—from self‐assembled block copolymers to inorganic nanoparticles, are discussed. A range of physicochemical parameters including the size, shape, surface chemistry, ligands attachment, stability, and stiffness are found to influence nanoparticles in MCTS. Some of these studies are complemented by animal studies confirming that lessons from MCTS can in part predict the behaviour in vivo. In summary, MCTS are suitable models to gain additional information on nanoparticles. While not being able to replace in vivo studies, they can bridge the gap between traditional 2D in vitro studies and in vivo models.     

Improving weld formability by a novel dual-rotation bobbin tool friction stir welding

A novel dual-rotation bobbin tool friction stir welding (DBT-FSW) was developed, in which the upper shoulder (US) and lower shoulder (LS) have different rotational speeds. This process was tried to weld 3.2 mm thick aluminum-lithium alloy sheets. The metallographic analysis and torque measurement were carried out to characterize the weld formability. Experimental results show that compared to conventional bobbin tool friction stir welding, the DBT-FSW has an excellent process stability, and can produce the defect-free joints in a wider range of welding parameters. These can be attributed to the significant improvement of material flow caused by the formation of a staggered layer structure and the unbalanced force between the US and LS during the DBT-FSW process.     

Investigating the Dynamic Characteristics of High-Temperature SOI CMOS VLSIC Elements

The static and dynamic characteristics of SOI CMOS inverters are investigated in the temperature range from–60 to 250°С. The experimental dependences of the dynamic and static currents, as well as the delay of the logic gate (inverter), on temperature are obtained. Based on these characteristics, the operability of SOI CMOS logic gates at high temperatures is estimated.     

Microwave Heating of an Emulsion Drop

The results of numerical modeling of the microwave heating of a water-in-oil emulsion drop in a gravity field with consideration of the empirical temperature dependence of the viscosity of the liquid surrounding the drop are presented. The system of thermal convection equations is considered in the Boussinesq approximation. The solution is obtained by the control volume method with the SIMPLE algorithm and by the VOF method. It is established that the emerging convective structures result in nonuniform heating of the drop predominantly near the surface, which can lead to a local rupture of the armor envelope and the formation of fine-dispersed phase. It is shown that there is an optimal range of power of microwave field in which an intensive deposition of water drops occurs, which leads to water-oil emulsion breakdown.