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The paper addresses the importance of using aluminum for the production of drill pipes. It also discusses one of the problems associated with the production of drill pipes having a protective thickening (central upset), such as the formation of a "streak delamination" type defect in the protector formation zone. Pipes with internal end and central upsets made of alloy D16T were selected as study objects. The extrusion process was performed under the following two experimental conditions: workpiece metal temperature—440 °C, punch travel speed—1.4 mm/s (option 1) and workpiece metal temperature—4 00 °C, punch travel speed—0.9 mm/s (option 2). It has been experimentally established that lowering the workpiece metal temperature by 40 °C and punch travel speed by 0.5 m/s during the extrusion process promotes the formation of a homogeneous macrostructure. By simulating the described experimental options of the processes, it was found that a 40 °C decrease in the workpiece metal temperature and a 0.5 m/s decrease in the punch travel speed during the extrusion process lead to a 50% reduction in the maximum deformation rate in the deformation zone, and to a 14% reduction in the degree of deformation. By calculating the stress condition parameter in the deformation zone, it became possible to show that performing the process according to option 2 results in a more favorable stress condition of the metal compared to option 1, which could also contribute to the reduction in the number of "streak delamination" type defects in the protector zone. [ABSTRACT FROM AUTHOR]

Multilayer metal composite materials are used in the chemical industry, particularly nuclear power engineering, and enable to increase the robustness and durability of steel structures while reducing their metal consumption. These materials are made of stainless steel, alternating with commercial quality steels, and have increased corrosion resistance, several times greater than the resistance of stainless steel in the material structure. In this work, the structure formation of the transition layer of a layered metal composite material obtained via explosion welding was studied through the transmission electron microscopy method. A high concentration of dislocations in the transition layer was established. After the blast exposition, the material retained its crystalline structure and acquired a directional texture. [ABSTRACT FROM AUTHOR]

The echogram of an ultrasonic pulsed flaw detector with the contact testing technique has been considered as a convolution when a transducer with a protector matching the couplant receives an acoustic pulse emitted by the same transducer through the couplant into the load and reflected from this load and from this transducer. A method is proposed for calculating echograms for products, transducers, and couplants made of any materials with any size of the contact layer, provided that the acoustic impedances of the materials used are known. A method is proposed for compensating interfering reflections for a transducer matched to the couplant. [ABSTRACT FROM AUTHOR]

A procedure for the calculation of the emitted acoustic pulse of a transducer that contains a piezoelectric crystal plate, damper, and protector is experimentally verified. The presence of a protector increases the sensitivity at high resolution (five half-periods of oscillation at the antiresonance frequency of the piezoelectric crystal plate or at the 50% transmission band at frequencies to 6 MHz) in comparison with the sensitivity of a transducer with an undamped piezoelectric crystal plate. The requirements for the materials of the transducer and its geometric dimensions are determined and an example of its manufacturing is given. The relationship that establishes the connection between the effective frequency of the echo pulse with the antiresonance frequency of the piezoelectric element is experimentally determined. The characteristics of known transducers and the proposed one are compared. [ABSTRACT FROM AUTHOR]

The wrist is the most frequently injured body region among snowboarders. Studies have shown that the risk of sustaining a wrist injury can be reduced by wearing wrist protection. Currently, there are a wide variety of wrist protection products for snowboarding on the market that offer a range of protective features. However, there are no minimum performance standards for snowboarding wrist protectors worldwide. The International Society for Skiing Safety convened a task force to develop a White Paper to evaluate the importance and necessity of a minimum performance for all wrist protectors used in snowboarding. The White Paper outlines the need for a general framework for a harmonized international standard and reviews the existing evidence. Therefore, this White Paper may serve as a common base for future discussions. The broader goal of developing and implementing such a standard is to reduce the incidence and the severity of wrist injuries in snowboarding without increasing the risk of adverse events, such as upper arm or shoulder injury. The European standard for inline skating wrist protectors (EN 14120) can serve as a starting point for efforts related to a standard for snowboard wrist protectors, but certain modifications to the standard would be required. It is hypothesized that implementation of a snowboarding wrist protector standard would result in fewer and less severe wrist injuries in the sport and could translate into more riding days for healthy snowboarders and significant health-care costs savings. [ABSTRACT FROM AUTHOR]

description is given of an environmentally friendly electric motor and transformer that operate in seawater and have no analogs in the world, as well as of the future underwater power supply during the development of the continental shelf and World Ocean. [ABSTRACT FROM AUTHOR]

The competitive binding of anthracycline antitumour drugs, [daunomycin (DAU), doxorubicin (DOX) or nogalamycin (NOG)], with caffeine (CAF) to a model DNA oligomer has been investigated by 500 MHz 1H NMR spectroscopy under physiological solution conditions. The method depends on the stepwise analysis of one-component (self-association), two-component (hetero-association and DNA complexation) and three-component interactions, in order to de-convolute the overall binding of the anthracycline antibiotic and CAF to DNA into two competing processes, viz. hetero-association of the antibiotic-CAF (‘interceptor’ action of CAF) and CAF–DNA complexation (‘protector’ action of CAF). It is found that the complexation of DAU with DNA in the presence of CAF is mainly affected by the CAF–DNA complexation, whereas the binding of either DOX or NOG to DNA is affected approximately equally by both the CAF–DNA complexation and CAF-antibiotic hetero-association. Quantitative evaluation of the three-component mixture of drug–CAF–DNA has enabled the proportion of the antibiotic displaced from DNA on addition of CAF to be calculated over a large range of CAF concentration, which may provide a quantitative basis for the change in anthracycline-related toxicity on addition of CAF. [ABSTRACT FROM AUTHOR]