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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 5, Issue 3 - Dec 1990
Volume 5, Issue 2 - Oct 1990
Volume 5, Issue 1 - Jun 1990
Selecting the target year
Fire Sensing Characteristics and Natural Convection in the Enclosure Partly Heated from Below
Journal of the Korean Society of Safety , volume 5, issue 2, 1990, Pages 6~16
In this paper, the natural convection in a square enclosure, partly heated from below, with two adiabatic vertical wall and one upper horigental wall is studied nomerically. In numerical study, SIMPLE(Semi-Implicit for Pressure Linked Equation) algorithems are applied for the integration of momentum and energy equation. The grid size used in this study is the coordinates of size (22
22). As a result of numerical analysis, the initial fluid flow depends on the thermal diffusion, but, as time passes, the fluid flow depends on convection and buoyancy of the enclosure. In Case 1, the heating region was been in the central position of the bottom wall. In case 2, the heating region was in the left position of the bottom. In case of Case 1, the lapse time of sensing the temperature of 72
is approximately 15 sec almost at the same time in the coordinates (6, 22), (11, 22). In case of Case 2, the lapse time in the coordinates (6, 22), (11, 22) was 27 sec, 25 sec repectively. Also in case of Case 1 or Case 2, the gradients of y-position of the two sensors are transposed each other.
A Study on Autoignition Characteristics of 1-Heptene, 2-Heptene and 3-Heptene.
Journal of the Korean Society of Safety , volume 5, issue 2, 1990, Pages 17~23
This study was performed by experiments with ASTM's apparatus for determination of autoignition temperature to obtain autoignition characteristics of 1-Heptene, 2-Heptene and 3-Heptene, respectively. As results, minimum autoignition temperatures (MAIT) of 1-Heptene, 2-Heptene and 3-Heptene were 246
, respectively and each dropping volume of these temperatures was 0.25
. Instantaneous ignition temperatures measured at each dropping volume of Heptene were 371
, respectively. Relation ignition delay time with ignition temperature at minimum autoignition temperature agreed well with Semenov's equation, and the values of apparent activation energy from this equation were 47Kca1/mo1 for 1-Heptene, 35Kca1/mo1 for 2-Heptene and 29Kca1/mo1 for 3-Heptene. It was found that the values of apparent activation energy decreased as the position of double bond changed from end to center in C-C chain.
A Study on the Determination of Stiffness and Optimum Shape for Corrugated Plate.
Journal of the Korean Society of Safety , volume 5, issue 2, 1990, Pages 24~31
In this study, the bending and twisting stiffnesses of corrugated plate were analyzed by applying equivalent idea, and the optimum shape of corrugated plate was determinated in the stiffnesses.
on Dangerous Gas Sensing Characteristics of
Journal of the Korean Society of Safety , volume 5, issue 2, 1990, Pages 32~39
compounds were oxidized in the furance after gas detecting sensor made molding as the Fe
the synthesized Fe
, by ferrous sulfate and sodium hydroxide. Their sensities on carbon monoxide, ethyl alcohol and L. P. G. were measured at various temperatures, respectively. And then their electrical resistivities, thermal properties (D.T.A. ＆ T.G.A.), were examined about their having an effet on the gas-sensing in company with the effect of pure
and the detecting sensor
, which reacts with
in the hydrothermal coundition, and the electrical conductive mechanism was reflected simultaneously. It was observed that the electrical conductivities and response ratios showed highest value at the endothermic temperature part, 300~35
of D.T.A.―curve. Consequently, the response ratios and response times of the hydrothermal detecting sensor were higher than that of pure detecting sensor, the specific surface areas were the highest at the endothermic range of D.T.A.-curve. These response ratios of detecting sensor for
, process at hydrothermal condition on carbon monoxide appeared higher than that on ethyl alcohol and in case of L.P.G. last.
Treatment of Nitrogen Oxides in Ambient Air using a Ion-Selective Electrode
Journal of the Korean Society of Safety , volume 5, issue 2, 1990, Pages 40~49
For the determination of polluant NOx in ambient air, nitrate ion-selective electrode(ISE) was made. To comparison of NOx in each method, the nitrate-ISE, NEBA, Orion electrode were used to determinee NOx in ambient air. In this work, the concentration of NOx in ambient air was average 0.06ppm. The results were good agreement with those obtained by each method within a relative error of 3％, Absorbing efficiency of nitrogen oxides in ambient air was good for Alkali solution. The determination of nitrogen oxides in ambient air using the Aliquat 336N-PVC membrane electrode was one of the useful method. The best characteristics of the Aliquat 336N-PVC me,mbrane electrode were obtained with the ion-exchanger concentration level of 6.5-9.1 percent by weight. The optimal membrane composition, was 9.09wt.％ of ion-exchanger, 30.95wt.％ of PVC, 60.6wt.％ of plasticizer (DBP), and 0.5mm of thickness. Under the above condition, the electrode approached the Nernstian slope most closely, and the linear response ranges produced the best results.
On the Metallic Surface Roughness Measurement by Laser Beam
Journal of the Korean Society of Safety , volume 5, issue 2, 1990, Pages 50~57
A new technique for the measurement of surface roughness based on the intensity fluctuations of laser light backscattered from a moving surface has been introduced. This paper reports a method of measuring surface roughness using coherent optics and interferometry. Included are both the theory of the technique and experimental verification. The range of surface roughness which can be accurately measured by this method is also reported.
Prediction of Forming Limit Diagram Using Plastic Instability Condition Considered Strain Rate.
Journal of the Korean Society of Safety , volume 5, issue 2, 1990, Pages 58~65
The purpose of this study is to consider the effects of strain rate on the stress-strain behavior of sheet metal at instability. The results and conclusions obtained as follows ： 1. As the strain rate increases, the fracture pressure increases and the polar height at fracture decreases. 2. The effect of strain rate on forming limit diagram produces a general lowering of the diagram with increasing strain rate but changes according to materials and strain paths. 3. The forming limit diagram predicted by swift instability theory is comparatively inconsistent with the experimental result at high strain rates, because there is inevitable gap between them.
A Study on the Structural Standard of the Tube and Coupler Scaffold
Journal of the Korean Society of Safety , volume 5, issue 2, 1990, Pages 66~75
This study is conducted to establish the structural standard of tube and coupler scaffold which is suitable for our present stuation through the comparison analysis for domestic and foreign standards as well as measurement of field survey. The results of this study are as follows ： 1) The load is classified by three categories, light-duty(equal and lower than 150kg/m
), medium-duty(150-250 kg/m
), and the equivalent horizontal length of side posts is each, 1.5-1.8m, 1.2-1.5m, equal and lower than 1.2m, and the equivalent horizontal length between front and rear posts is each 1.2-1.5m, 0.9-1.2m, equal and lower thatn 0.9m, in accordance with the load classification. 2) The height between upper and lower runner is equal and lower than 1.5m, and the brace across the width of scaffold should be installed within 15m in horizontal direction at 45 degree angle. 3) The entire scaffold should be securely tied to the wall of permanent structure with uslng anchor and bolt at intervals not to exceed 6m in case of non-connection and 4.5m in case of connection in both horizontal and vertical direction. 4) The post should be installed on the sound foundation tied to lumber footing with using base plate, and standard platform plank should be produced in the factory and widely used in the construction field.