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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Society of Safety
Journal Basic Information
Journal DOI :
The Korean Society Safety
Editor in Chief :
Volume & Issues
Volume 6, Issue 4 - Dec 1991
Volume 6, Issue 3 - Sep 1991
Volume 6, Issue 2 - Jun 1991
Volume 6, Issue 1 - Mar 1991
Selecting the target year
Properties of Electric Sofety for Dielectric Loss of Aging Natural Rubber.
Journal of the Korean Society of Safety , volume 6, issue 4, 1991, Pages 5~12
The dielectric properties of natural rubbers for electric safety are very important to investigate the molecular structure. The electric safety characteristics of the dielectric absorption in aging vulcanized natural rubber were studied in the range of frequency from 1
［Hz］l at the temperature of 23［
］. As the results, it has been confirmed that in the case of aging natural rubber of above 2 phr the specimens exhibit two kinds of dielectric losses due to the dipole polarization by impurities and sulfurs, and of raw rubber exhibit the kind of losses due to the dipole polarization. Rurthermore, dielectric loss maximum tansspectrum in high freguency region for electric safety, which removed to the low freguency according to increasing sulfur, depends greatly on sulfur.
The Polymer Membrane Electrode by Surfactants for Measuring Continuously Thiocyanate Ion in Wastewater
Journal of the Korean Society of Safety , volume 6, issue 4, 1991, Pages 13~20
Ion-selective electrode responsive to the thiocynate ion prepared by using the quaternary ammonium salts as a active material and PVC as a membrane matrix. The effect of chemical structure and composition of active material, and the membrane thickness on the linear response. the detection limit, and Nernstian slope of the electrode studied. Under the above optimum conditions of membrane, the effect of pH and the selectivity coefficients to various interfering anions were compared and investigated. It was concluded that the functions of thiocynate ion-selective electrode(ISE) were closely related to the chemical structure of the quaternary ammonium salts. The linear response, and the detection limit of the electrode potential increased with the increase of the carbon chain length of the alkyl group in the quaternary ammonium salts in the ascending order of Aliquat 336T, TOAT, TDAT, and TDDAT. The optimum membrane thickness was 0.3mm. The electrode characteristics was better with the decrease of the concentration of active material, and the best concentration was 3 weight percent. The membrane potential was independent of the pH variation in the region from pH 2 to 12. The order of the selectivity coefficients is as follows：Cl
Acoustic Emission Measurement on the Composite Material (CFRP)
Journal of the Korean Society of Safety , volume 6, issue 4, 1991, Pages 21~27
Acoustic Emission was monitored during tensile test and loading-holding-unloa-ding cycle test for two types (notched and unnotched) of CFRP specimens. AE activities showed that the fiber breakage during tensile tests depended upon the specimen geometry. We obtained new AE parameter such as the ration (damage ratio= AE events during unloading test / AE events during loading test) and the felicity ratio from which we investigated dynamic fracture process of CFRP specimens. The damage ratio of AE events was shown to be a good indicator to distinguish the generated fracture mechanism, such as fiber breakage and delamination. Also, ultrasonic testing results after loading-holding-unloading cycle test were good agreement with AE test results to detect defects or fiber breakage.
Simultaneous Removal of SO
and NO by Using Metal Oxide( II ) -Oxidative Sorption of SO
by Metal Oxide-
Journal of the Korean Society of Safety , volume 6, issue 4, 1991, Pages 26~33
To remove SO
from flus gas, cupric oxide, manganese oxide and iron oxide were studied with varying loading value. The experiment was carried out in a flow reactor and the reactants were prepared by impregnation method using alumina. The reaction temperature was varied from 30
. Experimental results showed that all of these metal oxides were effective on SO
removal reaction and cupric oxide was the best reactant. The sample with 10wt％ loading value was better reactant than with 20wt％ because in case of 20wt％ loading, metal dispersion on the alumina surface was not uniform. And the SO
removal efficiency was increased with the reaction temperature.
A Study on Response Time Index and Operating Time for Fusible Link Sprinkler Head
Journal of the Korean Society of Safety , volume 6, issue 4, 1991, Pages 34~44
In this study, the general solution of heat balance equation including conductive heat loss were suggested and were determined the constants with the results of experiment in hot tunnel in order to derive the general equation for the response time and to investigate the response time index which represent the characteristics of response of sprinkler head in actual fires. Two types of test were considered, the plunge test, in which the air temperature is represented by a step function, and the ramp test, in which the air temperature increases at a constant rate. As a result, simple equations were derived, which can be predicted the response time for the ramp type fire with the rate of temperature rise and gas velocity, for the plunge type fire with temperature and gas velocity. Also other useful data, such as the effective temperature, time constant, response time index and conduction parameter were obtained.
Effect of Width and Thickness Ratio on the Fatigue Crack Arrest Behavior of SA-508 Pressure Vessel Steel Variable Thickness Plates
Journal of the Korean Society of Safety , volume 6, issue 4, 1991, Pages 45~52
The purpose of a fatigue crack arrest desing is to prvent a fatigue fracture of machine and structure resulted from unstable crack growth. In all cases of load transfer to second elements such as stringers, doublers or flangers, crack arrest is possible; arrest occuring when the fatigue crack reaches the second element. In the present work, the possibility of crack arrest and the design criterion of fatigue crack arrest in the variable thickness plates are examined numericaiiy by using fatigue crack arrest thresthod
of SA-508 reactor vessel steel and stress intensity factor which was obtained in the previous work as a result of 3-dimensional finite element analysis for CT type variable thickness plates having discontinuous interface.e.
An Experiment al Study on the Bond Strength of Exterior tile Accoridng to Size
Journal of the Korean Society of Safety , volume 6, issue 4, 1991, Pages 53~57
Engineers of building construction have made efforts to produce more convinient building of good quality through the development of technology and raw materials nowadaye. This study is conducted to recognize problems of exterior tiles through experiments on quality of tiles according to sizes, and to find out and Iecommend most suitaff sizes of tiles. The sizes which are used widely in Construction field are selected as,45
200mm. Ready mixed compound are used as mortar and Compressed attachment method are used.
A Study on the Metallic Surface Roughness Measurement in Turning by Laser Beam
Journal of the Korean Society of Safety , volume 6, issue 4, 1991, Pages 58~65
In - process measurement of surface roughness is introduced which employs an optical method by using laser beam. This makes it possible to detect the surface roughness not only along the circurnferential path but also along the feed direction even during machining. The maximum roughness value is always abtainable from the reading along the feed direction.
A Study on Spontaneous Ignition of Granulated Activated Carbon
Journal of the Korean Society of Safety , volume 6, issue 4, 1991, Pages 66~72
Spontaneous ignition characteristics were observed by performing experiments for granulated activated carbon at constant ambient temperature in an oven. As the results of the experiments, the critical spontaneous ignition temperature of sample for large, intermediate and small vessels was 158.5
, respectively. It was found that the critical spontaneous ignition temperature decreased and the ignition induction time increased as the sample vessel size increased. Apparent activation energy of the sample calculated from the Frank= kamenetskii's thermal ignition theory was 17.81＊10
A study on the Determination of Fracture Toughness
Journal of the Korean Society of Safety , volume 6, issue 4, 1991, Pages 73~80
Interest in fracture of structure has increased significantly over the past decade. New approaches to analyze structural performance have been accompanied by the development of test methods to characterize material behavior in a manner compatible with the analysis. Several test methods have been developed as a results of advances in fracture mechanics, for example,
, R-curve tearing instability and CTOD approaches. Among the rest, fracture toughness
can be used as an effective design criterion in fracture mechanics. Generally, the determintion of
was performed according to ASTM E 813 or JSME S 001 and
was performed according to ASTM E 399. In this study, the test method for
Fatigue Crack Growth Rate Equation by Crack Closure
Journal of the Korean Society of Safety , volume 6, issue 4, 1991, Pages 81~87
We propose the crack growth rate equation which will model fatigue crack growth rate behavior such that constant stress amplitude fatigue crack growth behavior can be predicted. Constant stress amplitude fatigue tests are conducted for four materials under three stress ratios of R＝0.2, R＝0.4 and R＝0.6. Materials which have different mechanical properties i.e. stainless steel, low carbon steel, medium carbon steel and aluminum alloy are used. Through constant stress amplitude fatigue test by using unloading elastic compliance method, it is confirmed that crack closure is a close relationship with fatigue crack propagation. We describe simply fatigue crack propagation behavior as a function of the effective stress intensity factor range (
K) for all three regions (threshold region, stable region). The fatigue crack growth rate equation is given by da / dN＝A(
K) Where, A and m are material constants, and
is stress intensity factor range at low
is critical fatigue stress intensity factor.actor.
A Study of the Safe Measure on the Gun Powder Industries
Journal of the Korean Society of Safety , volume 6, issue 4, 1991, Pages 98~104