Heat treatment of organic polymers in a flow of a gaseous heat carrier

Processes of heat and mass transfer are studied during heat treatment of organic polymers in a superheated-steam flow. Promising environmentally safe engineering processes of treatment of plant biomass, plastics, and rubber wastes that contain petroleum products of sludges and soils are described. Academic Scientific Complex “A. V. Luikov Heat and Mass Transfer Institute of the Academy of Sciences of Belarus,” Minsk. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 69, No. 6, pp. 1021–1025, November–December, 1966.     

Finite-element modelling of creep-induced buckling of HDPE elements

Due to a pronounced trend in the world to make plastic products lighter, the phenomenon of buckling of viscoelastic bodies becomes very important. We present intermediate results of the program of investigation of the load-carrying capacity and buckling of plastic containers carried out in the Laboratory of Mechanical Reliability at the Delft Technical University (the Netherlands). We use the model of nonlinear viscoelasticity developed earlier and the finite-element method to simulate the process of buckling caused by the creep of strips andU-profiles made of high-density polyethylene. Industrial design Faculty, Delft Technical University, Delft, the Netherlands; Karpenko Physicomechanical Institute, Ukrainian Academy of Sciences, L'viv. Published in Fizyko-Khimichna Mekhanika Materialiv, Vol. 35, No. 2, pp. 44–52, March–April, 1999.     

On the efficiency of utilization of waste products for corrosion protection

We study the anticorosion activity of vast industrial waste products of the “Khimvolokno” Chernigov Industrial Concern and the “Azot” Rivne State Chemical Plant, estimate the level of ecological danger caused by these products, and show that the utilization of the waste products of the “Khimvolokno” Concern gives at least $120 of annual savings. Chernigov Technological Institute, Chernigov. Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 33, No. 2, pp. 112–114, March–April, 1997.     

On the “local approach” to the brittle fracture of structural materials

We consider the principles and sources of an important scientific direction in fracture mechanics-the so-called “local approach” to the problem of fracture of materials. This approach provides a possibility to describe their crack resistance based on conventional mechanical properties and opens up a direct way to determining the limiting state of structural elements. As the first example of the application of this approach, we present the principal propositions of the two-parameter K _μ-model of fracture, which relates the “global” K _Ic and “local” ρ_c and σ_c parameters via the yield condition on the contour of a small plastic zone near the tip of a crack. For the last decades, this direction was developed substantially and extended to the regions of quasi-brittle and ductile fracture. We also present the basic statements of this approach that were corroborated for the last decades. __________ Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 42, No. 2, pp. 39–44, March–April, 2006.     

Measurement of the ablation of heat shield materials by fiber-optical sensors

The results of the elaboration, testing, and application (in bench studies) of fiber sensors of linear ablation of a heat shield material are presented. The measuring technique and the structural arrangement of the sensors designed for products of the research and production association (RPA) “Energiya” and the design office “Novator” (Russia) have been described. Methods for manufacturing a ceramic tip equipped with fiber ablation sensors have been developed. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 81, No. 4, pp. 744–749, July–August, 2008.     

On the magnetization of solar convective zones

The condition of minimum entropy production has been used previously by the author [see Yu. V. Vandakurov, Proceedings of the SOHO 6/GONG 98 Workshop, Boston (1998), Vol. 1, pp. 567–571; Conference on the New Activity Cycle of the Sun [in Russian], St. Petersburg, Pulkovo (1998); Zh. Tekh. Fiz. (1999) [in press]] to find the rotation of stellar convective zones and, in particular, to find the latitude distribution of the rotation near the Sun. It turns out, however, that the self-excitation of even very slow meridional flows of the medium leads to “ smearing” of the entropy-production minima that were considered in the papers cited. In the presence of a toroidal magnetic field the “smearing” effect is eliminated. In the case of rotation of the solar type the necessary field is of the order of 10 kG, which can apparently be reconciled with the magnetic fields in bursts on the Sun. Pis’ma Zh. Tekh. Fiz. 25, 82–88 (May 26, 1999)     

Rheological factor of blood flow in SHF-local hyperthermia. “Rheomed” project

Different physicomathematical models of SHF hyperthermia, viz., local, regional, and extracorporal, are considered. All biothermal problems within the “Rheomed” project are solved analytically and numerically in conjugate formulations. Among the main advantages of the project is a new universal model of nonisothermal perfusion that is based on temperature-time superposition. Academic Scientific Complex “A. V. Luikov Heat and Mass Transfer Institute, Academy of Sciences of Belarus,” Minsk, Belarus. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 69, No. 3, pp. 356–359, May–June, 1996.     

A unified model of initiation and growth of fatigue macrocracks. part 3. stage of growth of a macrocrack

From a common viewpoint, fatigue fracture of materials is simulated by the process of initiation of an initial macrorack of lengtha _i =d ^* (d ^* is the constant of the material), which is successively (stepwise) repeated at the stage of its growth. As a result, the diagram “range of local stresses-period of initiation of an initial macrocrack” or ”range of local strains-period of initiation of an initial macrocrack,” which was determined for notched specimens, can be used for the construction of the diagram “growth rate of a macrocrack-range of the stress intensity factor” or “growth rate of a macrocrack-range of local strains,” respectively, if the crack is presented as a sharp notch with effective rounded radius ρ_eff=d ^* of the tip. Karpenko Physicomechanical Institute, Ukrainian Academy of Sciences, L'viv. Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 35, No. 3, pp. 5–14, May–June, 1999.     

On laws governing the splitting failure of flat metallic specimens subjected to thermal shock

Computed and experimental data on the splitting failure of copper, nickel, titanium, molybdenum, brass, and bronze metallic foils from 0.005 to 1 mm thick under thermal shock initiated by the x-radiation of a nuclear explosion are presented. It is proposed that the concepts “average energy liberated over the thickness (mass) of the specimen” ε, “specific absorbed energy” W, and “splitting strength of the material” σ be used as criterial characteristics of failure thresholds of optically thin flat metallic specimens (foils). It is demonstrated that the critical average energy liberation ε_*, which results in splitting, decreases logarithmically (ε_* =A _*-B _*log Δ) with increasing thickness Δ of the irradiated specimens in the interval Δ≈0.001–1 mm, and the critical specific potential energy W_* reguired to effect splitting increases with increasing optical mass m of the specimen under the law W_*=−αmlog (βm), where A_*, B_*, α, and β are certain parameters. It is shown that the longevity of the copper, nickel, titanium, molybdenum, brass, and bronze under radiation-induced thermal shock decreases exponentially with increasing amplitude of the failing stress (splitting strength) and can be described on the basis of the kinematic concept of strength. Deceased. Translated from Problemy Prochnosti, No. 1, pp. 37–47, January–February, 1997.     

Development of a structural model of deformation with hardening on the basis of distributed dislocations

We consider a problem of elastoplastic deformations with strengthening in the case where a “tooth” of yield is present in the (σ-∈) diagram. On simulation of the process of development of plastic deformations with hardening by using distributed screw dislocations, a conclusion on the existence of a structural parameter is drawn. Kherson Industrial Institute, Kherson. Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 34, No. 3, pp. 103–107, May–June, 1998.     

Measurement of particle velocity in a two-phase jet by double-exposure speckle photography

Double-exposure speckle photography was used to measure the instantaneous particle velocity field in an intense high-velocity two-phase jet. Scientific Academic Complex “A. V. Luikov Heat and Mass Transfer Institute, Academy of Sciences of elarus,” Minsk, Belarus. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 69, No. 2, pp. 224–229, March–April, 1996.     

Hardness of coatings of various filler materials in electric-arc metallization

The effect of the electrode material on the hardness of coatings in electric-arc metallization is studied experimentally. Academic Scientific Complex “A. V. Luikov Heat and Mass Transfer Institute,” National Academy of Sciences of Belarus, Minsk, Belarus. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 72, No. 5, pp. 983–987, September–October, 1999.     

Initiation of detonation by burning jets

We carried out an experimental investigation of the initiation of a detonation wave by burning jets at the orifice plate outlet. Academic Scientific Complex “A. V. Luikov Heat and Mass Transfer Institute of the Academy of Sciences of Belarus,” Minsk, Belarus. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 69, No. 1, pp 26–32, January–February, 1996.     

Determination of macrocrack start moment by acoustic-emission signals

On the basis of theoretical and experimental investigations, we determine the moment of start of a macrocrack by the acoustic-emission method. The amplitudes of acoustic-emission signals accompanying plastic deformation near a notch of the corresponding radius are evaluated. Finally, the acoustic-emission signals are compared with those generated at the moment of the macrocrack start. __________ Translated from Problemy Prochnosti, No. 5, pp. 149–156, September–October, 2006. Report on International Conference “Dynamics, Strength, and Life of Machines and Structures” (1–4 November 2006, Kiev, Ukraine).     

Influence of stefan flow on the characteristics of heterogeneous combustion of a carbon particle in air

The influence of Stefan flow and radiation-induced heat losses on the characteristics of stationary high-and low-temperature stable and critical regimes of heat and mass transfer of a carbon particle in air is analyzed. The investigations are sponsored by the International Fund “Vidrodzhennya” within the framework of the program ISSEP (contract No. K6V100). Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 70, No. 1, pp. 146–152, January–February, 1997.     

Uncertainty of measurement results in various scales

The relationship between the concepts of “error” and “uncertainty” of measurement results is examined. The concepts of “standard uncertainty,” “combined standard uncertainty,” and “expanded uncertainty” are shown to be inapplicable in nonmetric scales of quantities and properties, in which the general concept of “uncertainty” in the broad sense is recommended. Translated from Izmeritel'naya Tekhnika, No. 5, pp. 29–30, May, 2000.     

Academician H. V. Karpenko and the Formation of the Scientific Direction “Physicochemical Mechanics of Materials”

We describe the role of Academician H. V. Karpenko in the development of a new scientific direction “ Physicochemical Mechanics of Materials” and the formation of the Physicomechanical Institute of the Ukrainian National Academy of Sciences as a leading scientific center in the field of materials science. __________ Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 41, No. 3, pp. 7–16, May–June, 2005.     

Analysis of the error of measurements of the active electric power in symmetrical three-phase electric networks

The error in measuring electric power for “three-element” and “two-element” transformer circuits including the electric power meter is analyzed. It is shown that, unlike a “ three-element” circuit, a “two-element” measurement circuit has somewhat larger values of the measurement error. __________ Translated from Izmeritel’naya Tekhnika, No. 4, pp. 68–70, April, 2006.     

Avogadro program: Environmental problems of heat engineering

Results of some studies of formation and transformation of harmful substances during combustion of organic fuels are presented. The studies were conducted within the framework of the program “Environmental Problems of Heat Engineering” of the AVOGADRO system. Institute of Mechanics, M. V. Lomonosov Moscow State University, Moscow. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 69, No. 6, pp. 921–926, November–December, 1996.     

Thermal destruction of erythrocyte spectrin: Rheology,deformability, and stability with respect to detergents

By means of blood heating in the region of the thermal denaturation transition of spectrin (50°C) the relationship between the stability of erythrocytes with respect to detergents and their deformability and rheological parameters of blood was studied. Academic Scientific Complex “A. V. Luikov Institute of Heat and Mass Transfer, Academy of Sciences of Belarus,” Minsk, Belarus. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 69, No. 3, pp. 360–363, May–June, 1996.