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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 13, Issue 4 - Dec 1998
Volume 13, Issue 3 - Sep 1998
Volume 13, Issue 2 - Jun 1998
Volume 13, Issue 1 - Mar 1998
Selecting the target year
A Study on Driving Stability of In-cylinder Direct Injection Stratified Charge Gasoline Engine - Effects on HR rate and
of Fuel Injection Pressure and Load Variations -
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 3~10
In general, the stratified charge for direct injection gasoline engine should be introduced to achieve ultra-lean combustion scheme. In order to apply the concept of stratified charge into direct injection gasoline engine, a reflector was adapted on cylinder head. An installation of the reflector in front of the injector nozzle leads the mixture to be rich near spark plug. Therefore, the mixture near the spark plug is locally ich to ignite while the lean mixture is wholly introduced into the combustion chamber. In this paper, the characteristics of combustion is analyzed with the variations of injection pressure and load in a stratified-charge direct injection single cylinder gasoline engine.
Influence of dimensional ratio on collapse characteristics for the thin-walled structures of light weight
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 11~23
In this study, collapse test of thin-walled structure is performed under axially quasi-static and impact load in collapse characteristic to develop the optimum structural member for a light-oriented automobile. Furthermore, the energy-absorbing capacity is observed according to the variety of configuration(circular, square), aspect ratio in aluminum specimen to obtain basic data for the improved member of vehicle. In both quasi-static and impact collapse test, Al circular specimens collapse, in general, with axisymmetric mode in case of thin thickness while collapse with non-axisynmetric mode according to the thickness increase. For Al rectangular specimens, they collapse with axisymmetric mode in case of thin thickness, with mixed collapse mode according to the increase of thickness. In terms of initial max. load, Al square specimen turns out the best member among specimens, and then Al square, circular and circular with large scaling ratio, respectively. In case of quasi-static compression test, the absorbed energy per unit volume and mass shows higher in Al circular specimen, and then Al square, circular with large scaling ratio, respectively, according to shape ratio the absorbed energy per unit volume and mass in case of max. impact compression load is higher than that of static load. But the absorbed energy per unit volume and mass shows that Al circular specimen is the best member. Especially, unlike max. compression loan, the absorbed energy per unit volume and mass in impact test turns out the low value.
Stress Intensity Factors of a Combined Mode (I/III) Crack in a Variable Thickness Plate -CT Type-
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 24~31
Variable thickness plates are commonly encountered in the majority of mechanical/structural components of industrial applications. And, as a result of the unsymmetry of the structure or the load and the anisoptropy of the materials, the cracks in engineering structures are generally subjected to combined stresses. In spite of considerable practical interest, however, a few fracture mechanics study on combined mode crack in a variable thickness plate have carried out. In this respect, combined mode I/III stress intensity factors
at the crack tip for a variable thickness plate were obtained by 3-dimensional finite element analysis. Variable thickness plates containing a central slant crack were chosen. The parameters used in this study were dimensionless crack length
, crack slant angle
, thickness ratio
and width ratio
. Stress intensity factors were calculated by crack opening displacement(COD) and crack tearing displacement(CTD) method.
Fire Mitigation by Partitioning a Sodium Loop Building
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 32~44
Analysis on the study for the sodium fire mitigation was carried out using the CONTAIN-LMR code. Sodium loop building was partitioned into the many cells, in which the safety venting systems were installed for the purpose of improving the sodium fire safety and minimizing its effect on the sodium loop building. The effects of sodium fire on sodium loop building partitioned into the many cells and not partitioned were investigated. The peak pressure and temperature of each cell accompanied by sodium fire in sodium loop building partitioned were lower than those of sodium loop building not partitioned. In the case of partitioning sodium loop building, the pressures, temperatures and aerosols into cells were transferred through propagation path of CONTAIN-LMR sodium fire model simulated by this study, and the effect of sodium spray fire on sodium loop building was mitigated by partitioning building. In addition, the excessive rise of pressure into cells was prevented by installing the over-pressure exhaust valve and under-pressure exhaust valve on the flow path between cells.
Preparation of Spacer for Safety Improvement of Architecture
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 45~50
The low grade domestic kaoline, such as pink-C and white-D, was converted to metakaoline, which has pozzolanic reactivity by heat treatment in the temperature range of
for preparing the spacer. The spacer was used for supporting the reinforced steel rod during construction to improve the safety of architecture. Pink-C and white-D were completely dehydroxylated when burnt at 80
for 1 hour and converted to metakaoline. The compressive strengths of specimens added calcined pink-C were lower than those of press molding mortar products inspite of calcining conditions. When white-D with calcined 80
for 1 hour was mixed 30% in the weight ratio of cement, the specimens cured 28 days had 338
of compressive strengths, respectively.
Effects of the partial admission rate and cold flow inlet-outlet ratio on energy separation of Vortex Tube
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 51~59
The vortex tube is a simple device for separating a compressed fluid stream into two flows of high and low temperature without any chemical reactions. Recently, vortex tube is widely used to local cooler of industrial equipments and air conditioner for special purpose. The phenomena of energy separation through the vortex tube were investigated to see the effects of cold flow inlet-outlet ratios and partial admission rates on the energy separation experimentally. The experiment was carried out with various cold flow inlet-outlet ratios from 0.28 to 10.56 and partial admission rates from 0.176 to 0.956 by varying input pressure and cold air flow ratio. To find best use in a given cold flow inlet-outlet ratio and partial admission rate, the maximum temperature difference of cold air was presented. The experimental results were indicated that there are an optimum range of cold flow inlet-outlet ratio for each partial admission rate and available partial admission rate.
Development of the 400 Series Stainless Steel Powder Sensor Ring for Use in an Antilock Brake System
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 60~66
ABS sensor ring has been manufactured by P/M method using 400 series ferrite stainless steel. The results are as following: It is supposedly sufficient to use for control computer due to good experimental results of magnetic characteristics. Compared with sensor ring made by iron, 400 series ferrite stainless steel has shown a good corrosion resistance without an addition surface treatment. Thus the decreasing production process has been obtained. As a result of hardness and tensile test, 400 series ferrite stainless steel shown a good endurance when it is combined to C/V joint, and has a good hardness properties endurable to sand and pebble impact.
A Study of De-electrification Characteristics of Charged Body By Soft X-Ray Ionizer
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 67~73
The technology for neutralizing static electricity by soft X-ray radiation has been newly developed. This technology involves ionization of gas molecules in the vicinity of a charged substrate to generate ions and electrons to reduce electrostatic potential. The ULSI device substrate and liquid crystal display substrate tend to get charged instantly to a high potential level when they are handled in the manufacturing process. Soft X-ray radiation is adequate in air or
gas at atmospheric pressure. This newly developed neutralization method is effective to be superior to the conventional technique, i.e., an ionizer by using corona discharge ,in every aspect. The new method features excellent neutralization capability and is able to completely reduce electrostatic potential to 0 V within a short time. Moreover, this is a very clean antistatic technology free from particle generation ,ozone generation, and electromagnetic noise, which are problems in using the corona discharge ionizer.
A Study of Measurement of Minimum Ignition Energy for Pine Tree Dust on Electrostatic Discharges
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 74~79
To establish measuring method for minimum ignition energy of explosive powders caused by electrostatic discharge, A measuring method(Hartman) using a very small quantity of pine tree testing powder was proposed, and the influence of discharge current limiting resistance connected in series into a capacitive discharge circuit on ignition energies of explosive powders was investigated. As a result the minimum ignition energy was 42.25mJ when discharge current limiting resistance 300
Development of Discharge Model and Preventive Diagnosis Program for Discharge Risk Assessment of Charged Human Body
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 80~87
This paper presents a study on the development of discharge model and computer program for assessing the risk of electrostatic discharge(ESD) of charged human body This ESD event is modelled as a two-body problem using spherical conductors, simulating the approach of a charged conductor (human body) to a second conductor (electronic equipment). The charge/discharge process for the model is formulated as a matrix of equations by Maxwell's method. Body potentials, energies and the charge transfer during a discharge are calculated. The developed program, based on the suggested scheme in this paper, is applied to a sample system. The results provide a better understanding of ESD event and demonstrate the usefulness of two-body model in practical applications.
The Influence of Dry Treatments on the Surface Degradation and Dielectric Properties in Fiber Reinforced Plastics
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 88~95
In this paper, we investigated the change of wettability, surface potential decay and dielectric properties caused by ultraviolet-treated, thermal-treated and discharge-treated FRP(fiber reinforced plastics) respectively for finding out the influence of dry treatments effected to electrical characteristics on the surface of polymer composites. For the change of wettability, the contact angle of thermal-treated specimen with the high temperature of
increased. But that of UV-treated and discharge- treated specimen decreased. The characteristic of surface potential decay shows the tendency of the remarkable decrease on UV-treated and discharge-treated specimens, but no difference on thermal-treated specimen compared with untreated one. Also, for the dielectric properties, it shows the increase at large on the treated specimens and especially, the remarkable increase on thermal-treated one.
Anti-Flammability for EEA-VLDPE compound using
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 96~101
In order to study the change in mechanical properties and anti-flammablilty of ethylene-ethylacrylate copolymer(EEA) very low density polyethylene(VLDPE) compound that could be used as communication cable sheath using
as a non-toxic flame retardant, 100, 125, and 150phr
were added to 100 parts of EEA-VLDPE compound, 100 EEA : 0 VLDPE, 50 EEA : 50 VLDPE, and 0 EEA : 100 VLDPE, respectively.
was a good non-toxic flame retardant for communication cable sheath and anti-flammability increased with the amount of
in compound. The mechanical properties-MI, Ts, and Eb-decreased with increasing in the mixing ratio of EEA but oxygen index(OI) increased with increasing in the amount of EEA. The best composition of
in this study was 150phr to 50 EEA : 50 VLDPE compound for the anti-flammability.
A Study on the Properties of the Heavy Duty Rust-Converting Agent used in the Potential Hazard Areas of Fire & Explosion
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 102~111
This study was concerned with the development of a heavy duty rust-converting agent, the function of which is to form metal complex coatings, containing vinyl halide-acrylic terpolymer emulsion, defoamer, emulsifying agent, glass flakes, chelating agent such as gallotannic acid, gallic acid, and pyrogallic acid, and other additives. The resulted emulsion products(Sample No.1~No.5) were characterized through test either in the forms of emulsions, which include Viscosity, Penetration rate, Acidity and Film drying rate test, or in the forms of coated layer on rusty steel substrates by FT-IR, which include hardness, gloss, salt spray, adhesion and flame retardant test. The test results are as follows ; Penetration rate(0.1~0.4 mm/min), Solid content(70%), Acidity (pH 1.8~2.0), Specific gravity(1.30~1.35), Film drying rate(108min, RH 40% ; 150min, RH 80%), Gloss(83~92, incident angle
; 88~97, incident angle
), Pencil hardness(4H~5H), Adhesion (100/100), Salt spray test(>720Hr), LOI(%) value(38%), Vertical burning test(UL 94-v-l). According to the various performance of specimens show above, the evaluation of the availability of this heavy duty rust-converting agent can be concluded that all the samples(No.1~No.5) are capable of being used in the field of chemical plant and in the hazard areas of fire and explosion potential. It was observed that the properties of sample No.2, especially gloss and hardness, were much better than that of the other samples.
A Study on the Mixing Characteristics of Solid in Vibrating Feeder for Stable Operations of Fluidized Bed Combustion
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 112~118
This work has been carried out to study the mixing characteristics of solid in vibrating feeder for stable operations of fluidized bed combustion. The system consisted of two particles such that fine particles were located on the top of the coarse particles before vibratory mixing had started. Effect of particle size, particle densities, vibration amplitude and vibration frequency were experimentally obtained. Also, a diffusion model was applied in interpreting the experimental results. From these results, the following empirical equation for the diffusivity was obtained.
2nd Flame Phenomena in Laminar Flame Propagation of Dust-Air Mixtures
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 119~125
In long vertical duct, the aspect of second flame in laminar flame propagating through lycopodium-air mixtures and the behavior of dust particles in neighborhood in front of flame have been examined experimentally. In order to trace the development of second flame to its origin, the velocity and vorticity distribution of dust particles in front of flame were measured by using with the real-time PIV system. The velocity of particles was approximately zero at the central part of flame front and the ahead of the flame leading edge, but maximum near the duct wall. The flame velocity of second flame and the movement of leading flame edge depend mainly on behavior of dust particles by the flow distribution of temperature and pressure.
A Study on the Load Carrying Capacity Assessment Method of the Prestressed Concrete Beam Bridges
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 126~134
In this paper, the field test by truck load and the structural analysis were performed on a prestressed concrete beam bridge to investigate the load carrying capacity of the prestressed concrete beam bridges. From the results of the field test and the structural analysis, CAF (composite action factor), TIF(transformed impact factor), and
(load carrying capacity) of the prestressed concrete beam bridges were studied, and the load carrying capacity assessment of the prestressed concrete beam bridges were carried out using these factors.
Monitoring & Analysis on Excavation Failure Modes by Centrifugal Model Experiment
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 135~142
This paper is to investigate the failure surface and modes in a soil mass by a excavation of the model ground. To study the failure surface for the excavated slope, centrifugal model tests were performed by changing the angle of the excavated slope(50, 75,
) and the ground condition(
=60, 90%, dry and submerged ground). Excavation was simulated during the centrifuge tests by operating a valve that allowed the zinc chloride solvent to drain from the excavation. Results of model tests were compared with those obtained with theoretical solutions using limit equilibrium analysis method. The results of model tests show that, there is a failure to create a straight line in the low angle of excavated surface and a create a circle as the angle increases. Also, as the angle of excavated surface is increasing, the angle of the failure surface increases. The failure length in the submerged ground increases approximately 1.10~1.34 times more than that of the dry ground.
State-of-the-Art and Perspectives of the Industrial Accident Compensation Insurance System in Korea
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 143~162
There are two ways to prevent labor from Industrial accident One is pre-prevention, another is compensation. Onless It happens the compensation problem from The pre-prevention, It will be best way to solve. To prevent lobar widely first, the application range should be wide which is base of repayment second, assoradiy to reconsideration of apportionment properly The Max-Min limitative cost of compensative should be paid, one the other hands, The lay-off payment of limitative and The fixed payment of Funeral should be introduce Third, The specialization of examination.
Differential Quadrature Analysis for Vibration of Wide-Flange Curved Beams
Ji-Won Han ; Ki-Jun Kang ;
Journal of the Korean Society of Safety , volume 13, issue 3, 1998, Pages 163~170
The differential quadrature method (D.Q.M.) is applied to computation of eigenvalues of small-amplitude free vibration for horizontally curved beams including a warping contribution. Fundamental frequencies are calculated for a single-span, curved, wide-flange beam with both ends simply supported or clamped, or simply supported-clamped end conditions. The results are compared with existing exact solutions and numerical solutions by other methods for cases in which they are available. The differential quadrature method gives good accuracy even when only a limited number of grid points is used.