scholarly journals THE DETERMINATION OF THE PROTECTIVE LAYER ON THE REPOSITORIES OF URANIUM MINES

2014 ◽  
Author(s):  
Ilona Hummelova
Keyword(s):  
Protective Layer ◽  
Uranium Mines

scholarly journals Features of the Surface and Subsurface Waves Application for Ultrasonic Evaluation of Physicomechanical Properties of Solids. Part 1. Influence of the Geometrical Parameters

2018 ◽  
Vol 9 (4) ◽  
pp. 325-326
Author(s):  
A. R. Baev ◽  
A. L. Mayorov ◽  
M. V. Asadchaya ◽  
V. N. Levkovich ◽  
K. G. Zhavoronkov
Keyword(s):  
Protective Coating ◽  
Layer Structure ◽  
Base Material ◽  
Protective Layer ◽  
Body Waves ◽  
Measuring System ◽  
Geometrical Parameters ◽  
Small Aperture ◽  
Ultrasonic Evaluation

Application of surface and subsurface waves for control of objects with a double-layer structure allows to extend possibilities of diagnostics of their physico-mechanical properties. The purpose of work was to determine conditions and offer recommendations providing measuring of ultrasonic velocity and amplitude of the former modes in protective layers and in basis of object at one-sided access to its surface.The analysis of an acoustic path of a measuring system in relation to ultrasonic evaluation of the objects having the restricted sizes and the protective coating according to velocity data of the surface and subsurface waves propagation is made. On the basis of representations of beam acoustics the dependences connecting a wavelength of the excited surface and subsurface modes, thickness and width of a controlled object, acoustic base of a sounding are defined. There are to provide a condition leveling of the influence of an acoustical noise created by the reflected and accompanying waves on parameters of acoustic signal with the given quantity of oscillations in an impulse.The principle opportunity is shown and conditions for determination of velocity of subsurface body waves in the base material which is under a protective coating layer are established. For these purposes on the basis of use of the block of ultrasonic probes the optimum scheme of a sounding is offered and the analytical expression for calculation of required velocity considering varying of thickness of a covering is received.The method of acoustical measuring realized by a direct and reverse sounding of the objects with small aperture and angle probes was analysed and formulas for determination of speed of subsurface wave under protective layer of the wedge form have been got. An ultrasonic device is suggested for the excitationreception of subsurface waves with different speed in objects (on 20–35 %) using for the acoustic concordance of environments of metallic sound duct as a wedge. Possibility of leveling of interference in a protective layer to control efects in basis of material by a volume wave by creation of supporting echo-signal of longitudinal wave of the set frequency and entered normally to the surface of object was studied.

Determination of the thickness of the protective layer of copper on mirrors

1971 ◽  
Vol 28 (2) ◽  
pp. 119-120 ◽  
Author(s):  
I. I. Borisova ◽  
�. P. Bil'tyukova
Keyword(s):  
Protective Layer

scholarly journals Calibration of test probes and experimental monitoring of changes in moisture of selected materials of subgrade structures

2018 ◽  
Vol 196 ◽  
pp. 04058
Author(s):  
Peter Dobeš ◽  
Libor Ižvolt ◽  
Martin Mečár
Keyword(s):  
Protective Layer ◽  
Railway Track ◽  
Winter Period ◽  
Moisture Determination ◽  
Experimental Stand ◽  
Crushed Aggregate ◽  
Railway Engineering ◽  
Track Management ◽  
Structural Layer

The paper describes experimental activity carried out at the Department of Railway Engineering and Track Management of the Faculty of Civil Engineering, University of Žilina. It focuses on monitoring moisture changes in individual structural layers of the railway track body and its subgrade, performed on the railroad model, (1:1 scale). The Introduction characterizes the experimental stand models of the Department, used for monitoring the moisture changes in the structural layers. The second part of the paper focuses on the characteristics of the moisture determination method - time reflectometry (TDR method), and on the calibration of TRIME PICO IPH T3 probes for real materials of the experimental stand DRETM (crushed aggregate, fr. 0 / 31.5 mm - protective layer, crushed aggregate, fr. 0/63 mm - embankment, clay with the addition of river gravel – foundation). The calibration was a substantial prerequisite for the subsequent humidity monitoring of the railway models. The next part of the paper presents the recorded moisture values of the structural layer materials, built in the measuring profiles of the experimental stand DRETM, measured before and during the winter period 2017/2018. The Conclusion evaluates the measured values and the determination of the input moisture values that will be used for the numerical modeling of the thermal regime of subgrade structure by the SoilVision software.

scholarly journals Determination of distribution of heat-conducting material concentration in protective layer of thermal protection system panel

2019 ◽  
Vol 23 (Suppl. 4) ◽  
pp. 1025-1034
Author(s):  
Lukasz Brodzik ◽  
Andrzej Frackowiak
Keyword(s):  
Thermal Protection ◽  
Protective Layer ◽  
Heat Conducting ◽  
Conducting Material ◽  
Protective Properties ◽  
Conductive Material ◽  
Time Extension ◽  
Heating Up ◽  
Dope Concentration

Paper presents the problem of heating the damaged insulation of an orbiter. Changes of the insulation?s thermal properties, made by adding conductive material of high value of specific heat in a form of a dope to the protective layer, were examined. An iterative algorithm determining a variable of dope concentration in the material was developed. Insulating material LI900 was used for calculations. Determination of distribution of conductive material concentration was made for materials which, after verification, demonstrated the most beneficial effect on protective properties of the modified insulation layer. Change of properties was to enable time extension of the LI900 insulation tile heating up to the maximal temperature and, additionally, to lowering this temperature.

Optimization of the heat flow by solving inverse problem in the protective layer of the TPS panel

2019 ◽  
Vol 30 (6) ◽  
pp. 2989-3003 ◽  
Author(s):  
Łukasz Brodzik ◽  
Andrzej Frąckowiak
Keyword(s):  
Protective Layer ◽  
Inverse Heat Conduction ◽  
Insulation Layer ◽  
Protective Properties ◽  
Content Type ◽  
Conductive Material ◽  
Time Extension ◽  
Inverse Heat Conduction Problems ◽  
Heating Up

Purpose This paper aims to present the problem of heating the damaged insulation of an orbiter. Design/methodology/approach Changes of the insulation’s thermal properties, made by adding conductive material of high value of specific heat in a form of a dope to the protective layer, were examined. An iterative algorithm determining a variable of dope concentration in the material was developed. Findings Determination of distribution of conductive material concentration was made for materials which, after verification, demonstrated the most beneficial effect on protective properties of the modified insulation layer. The problem of determining the distribution of metal filings concentration in the insulation layer of the coating belongs to inverse heat conduction problems. Originality/value Change of properties was to enable time extension of the LI900 insulation tile heating up to the maximal temperature and, additionally, to lowering this temperature.

scholarly journals Determination of distribution of heat-conducting material concentration in protective layer of TPS panel

2018 ◽  
Vol 240 ◽  
pp. 01007
Author(s):  
Łukasz Brodzik ◽  
Andrzej Frąckowiak
Keyword(s):  
Volume Fraction ◽  
Protective Layer ◽  
Aluminum Surface ◽  
Heat Conducting ◽  
Conducting Material ◽  
Insulating Material ◽  
Conductive Material ◽  
Percentage Volume ◽  
Constant Percentage

Paper presents the problem of heating the damaged insulation of an orbiter. Changes of the insulation’s thermal properties, made by adding conductive material of high value of specific heat in a form of a dope to the protective layer, were examined. The analysis was made using insulating material LI900 and beryllium dope. In the paper was investigated the effect of the dopant’s share on the temperature distribution on the aluminum surface. This influence was depended on the size of the damage, defined by parameter D, as well as a constant percentage volume fraction.

scholarly journals ASSESSMENT OF THE DEPTH AND RATE OF CORROSION IN STEEL REINFORCEMENT OF REINFORCED CONCRETE CULVERTS

2020 ◽  
Author(s):  
Alexandr Vasiliev ◽  
Svetlana Daškevič
Keyword(s):  
Reinforced Concrete ◽  
Protective Layer ◽  
Corrosion Damage ◽  
Steel Reinforcement ◽  
Operating Conditions ◽  
Protective Properties ◽  
Open Atmosphere ◽  
Concrete Elements ◽  
Corrosion State

Based on the results of many research years on concrete carbonisation: both immediately after manufacture (using heat-moisture treatment) and in reinforced concrete elements operated for the periods of various length (in an open atmosphere); the effect of carbonisation on the change in the protective properties of concrete in relation to steel reinforcement; for determination of the dependence of the corrosion state of steel reinforcement on the degree of concrete carbonisation in the area of steel reinforcement; the obtained regression dependences of the change (by time in the cross section) of the degree of concrete carbonisation of various classes in strength, – the analysis of the time of the onset of the boundary values of the degrees of concrete carbonisation (strength classes C12/15–C30/37) for the operating conditions of the open atmosphere was performed. Based on it, the regression dependences of the time variation of the depth of corrosion damage of steel reinforcement were construed (for fixed thicknesses of the concrete protective layer). The obtained nature of dependences made it possible to offer, in a general form, the regression dependences of the depth of corrosion damage and corrosion rate of steel reinforcement for concretes (strength classes C12/15–C30/37) for operating conditions in open atmosphere.

scholarly journals DETERMINATION OF SUCCINIC DEHYDROGENASE ACTIVITY IN TISSUE CULTURE

1959 ◽  
Vol 7 (2) ◽  
pp. 144-146 ◽  
Author(s):  
NATHAN KAUFMAN ◽  
ROBERT HILL
Keyword(s):  
Tissue Culture ◽  
Dehydrogenase Activity ◽  
Hela Cells ◽  
Succinic Dehydrogenase ◽  
Protective Layer ◽  
The Other ◽  
Tissue Cultures ◽  
Succinic Dehydrogenase Activity

Two methods of demonstrating succinic dehydrogenase activity in tissue cultures of HeLa cells have been demonstrated. One method employs a protective layer of agar applied to the cells prior to incubation in the selected substrate. The other method uses a mixture of agar and substrate which is placed on the cells; incubation follows without the further addition of substrate.

Research on corrosion mechanism of refractory lining in drip zone of COREX melting gasifier

2021 ◽  
Vol 118 (3) ◽  
pp. 312
Author(s):  
Xiaoge Wang ◽  
Pengcheng Li ◽  
Huili Sun ◽  
Shitao Song
Keyword(s):  
Refractory Lining ◽  
Protective Layer ◽  
Volume Density ◽  
Corrosion Mechanism ◽  
Relevant Research ◽  
Mechanical Erosion ◽  
Refractory Bricks ◽  
Slag Erosion ◽  
Selection Of

In this paper, the COREX-3000 melting gasifier was dissected and sampled to obtain the macroscopic erosion appearance of refractories lining in the drip zone, and the erosion behavior and mechanism of refractory bricks in the drip zone were analyzed by means of chemical analysis, XRD, SEM and determination of physical characteristics. The results showed that the maximum average erosion of refractory lining bricks in the drip zone was 220 mm and the erosion rate was up to 69%. Its surface was mainly affected by slag erosion and mechanical scour of slag, but at high temperature, the surface of refractory could be re-sintered, forming a protective layer, which improved the volume density and high compressive strength of refractory, which was advantageous to the improvement of refractory brick slag resistance invasion and mechanical erosion resistance. Relevant research results can provide theoretical basis for the selection of refractories lining in the drip zone of COREX melting gasifier.

scholarly journals An Electrochemical Study of Aluminum Corrosion in Boiling High Purity Water

CORROSION ◽  
1967 ◽  
Vol 23 (12) ◽  
pp. 365-370 ◽  
Author(s):  
R. A. LEGAULT ◽  
J. E. DRALEY
Keyword(s):  
Experimental Data ◽  
Protective Layer ◽  
Potential Drop ◽  
R And D ◽  
Total Potential ◽  
A Value ◽  
Wide Range ◽  
Aluminum Corrosion ◽  
Simplifying Assumptions

Abstract An equation relating current and electrochemical potential has been derived on the basis of a physical model of the corrosion process. In the model, the total potential drop from metal to solution is the sum of potential contributions arising from the interfacial reactions at the metal-oxide and oxide-solution interfaces and that which derives from the transport of charged species through the film. On the basis of some simplifying assumptions, the derived equation reduces to ΔE = IR + Ksℓn (1 + ID), where R and D are complex constants and Ks is equal to RT/αzF for the liberation of hydrogen at the surface of the protective layer. This equation has been fitted successfully to experimental data. Assigning the value usually attributed to α for the hydrogen reaction, 1/2, optimum values of the constants were found to vary reasonably with time. If a value of α is not assigned, the equation can be fitted to experimental data over a wide range of values for the three constants. Polarization measurements alone are not sufficient to determine unequivocal values for the constants, hence a determination of the mechanism of the aqueous oxidation of aluminum will require additional independent measurements.

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