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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society of Safety
Journal Basic Information
Journal DOI :
The Korean Society Safety
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Volume & Issues
Volume 16, Issue 4 - Dec 2001
Volume 16, Issue 3 - Sep 2001
Volume 16, Issue 2 - Jun 2001
Volume 16, Issue 1 - Mar 2001
Selecting the target year
A Study on the Fatigue Crack Growth Behaviour for the Welded Configuration in Pressure Vessel Stiffener
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 1~6
The study is to investigate the influence on the fatigue crack growth behaviors for the welded configuration in pressure vessel stiffener. In order to perform this goal, the automatic welded specimens were prepared. The material is ASTM A516 grade 60 steel used in pressure vessel mainly. In skip welding of pad-on-plate, continuous fillet welding and PWHT specimen, fatigue crack is generally initiated at the starting and end old toe zone, and ruptured at the starting old toe zone. The fatigue life of pad-on-plate of the continuous fillet welding specimen is larger than that of pad-on-plate skip fillet welding specimen about 85% under low load, about 20% under high load and less than that of two-pad continuous fillet welding specimen about 85%. In da/dN-
K curve under low load, skip fillet welding specimen of pad-on-plate showed retardation on the initial crack, and the fatigue crack growth rate at the low region of
K greater specimen E(
). And the fatigue life of welding specimen was smaller than that of PWHT specimen.
A Study on the Fatigue Crack Growth Behavior of Titanium Welding Material
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 7~11
In this study, specimens were classified four welded specimens and a base metal to investigate fatigue life and crack growth rate of pure titanium welding materials, and Ti was used in turbine equipment of nuclear power generation, etc. The summarized results are as follows; 1) Specimen-2 was bigger 712% than base metal, when it was compared with other welding materials, 2) As the result of specimens data, specimen-2 crack behavior rate res lower 30 times than base metal, and so total fracture life was very influenced by it, 3) Notch tip of Specimen-2 was offsetted 6.7mm from boundary H.A.Z, and if formed 25% in total fracture length, 4) As the considering of da/dN and
K, Paris' law is incongruous in this study, because fro inclines nsf on one date.
The effect of Inclined angle of Channel with multi heat source on Thermal Stability of Electronic Equipment
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 12~18
The objective of the present work is to examine the effect of inclined angle of channel with multi heat source on thermal stability of electronic equipment. The heat sources are mounted on both sides of channel walls by two kinds of configuration such as the zig-zag md symmetric on. Conductive heat transfer was estimated by using of thermocouples and heat flux sensor. Thus, convective heat transfer and mean Nusselt number could be obtained. With increased inclined angle, the convective heat transfer coefficient was decreased. When inclined angle was smaller than 30 degree, The average Nusselt number of Big-zag configuration was larger than that of symmetric. Furthermore, when protruding ration was 0.082, the temperature was strongly affected by inclined angle. whereas, when protruding ration was 0.25, the temperature was strongly affected by heat source configuration.
A Study on Fatigue Characteristics of Dissimilar Spring Steel(SUP9A)-SM25C by Friction Welding
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 19~25
The friction-welding SM25C is a substitute for the suing steel that is utilized in the machinery, airplane, and automobile, ok. This substitution would provide reduction of material and weight of welding parts. From the result we found that the strength of the friction welded joint was 529-617MPa and the toughness 1.2 times higher than that of the base metal. The optimal condition of friction welding was found as follows : n=2000rpm,
=2-4sec, Considering the strength, the hardness, and the reduction of area in the friction welding, the fiction welding using SUP9A and SM25C was found to cause no problem in on-the-job application.
A Case Study of Creep Crack Growth Remaining life Assessment for High Temperature Pressure Equipments
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 26~30
Creep crack growth lift of high temperature pressure equipments was assessed for various crack locations and for various material properties. Surface cracks at the inner and outer surface of the vessel in the axial and circumferential directions were considered. The crack was located in the weld metal, in the parent metal or at the weld interface. Results shored that the crack at the weld interface was the most dangerous one. The crack located outside is weaker than that located inside. Safety factors of the case in which improper material properties were used the to unavailability of the correct material properties were discussed.
Discussions on the Cause of Bucheon LPG Station Accident
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 31~34
Cause of Bucheon LPG refueling station accident could not be clearly verified because of opposite talking of men reponsible for the accident the accident, damaged by BLEVE and fire, and no systematic fire investigation. After two and half years, recently first judgement has been carried out. But competitive arguement is going on and first leak point of massive LPG will not be clearly identified with evidences acquired by now. This accident gave us many instructions and advices. Specially, massive LPG leak can result in pool fire and safety of underground-installed storage tank is proved by no damage in the strong BLEVE.
Study on Surface Roughness due to WA-BF-Fe Grain for Internal Magnet-abrasive Finishing Apparatus of STS 304 Pipe
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 35~40
An internal finishing process applying Magnetic Abrasive Finishing (MAF) was proposed to produce smooth inner surfaces of tubes at a high rate. Since this process uses the tube rotation system, it has been considered applicable only to tubes which are rotatable at high speeds. Here development of the stainless tube(STS 304) rotation system to extend the scope of the application of the internal finishing process applying MAF was made. By the stainless tube(STS 304) rotation system, the abrasive magnetically attracted by the poles is rotated along the inner surface of the tube by magnetic force together with fixed poles, finishing the inner surface of the tube. The main results obtained are as follows : 1) The magnet abrasive finishing minimized influence due to external force because non-contact finishing, 2) The profile of surface roughness decreased very good in 11.4m/min range because abrasive size and speed, 3) The profile of surface roughness by flux density decreased in finishing speed 28m/min, 4) The profile of surface roughness by fled rate decreased in 0.16mm/rev and 0.18mm/rev.
NOx Removal Characteristics by the Dielectric Packed-bed Plasma Reactor
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 41~44
The removal characteristics of nitrogen oxides (NOx) by the dielectric (
) packed-bed plasma reactor are experimentally investigated Reactor is packed with 5[mm] diameter
beads, and was desisted to remove NOx at atmospheric pressures from the moving pollution source such as diesel automobile. The experiments were conducted for applied voltages from 5 to 10[kV], flue gas rate from 2 to 5[l/min] and frequency from 0.5 to 2[kHz]. The NOx removal efficiency significantly increasing with increasing applied voltage. Especially removal rate significantly increased with increasing frequency. However, in this experiment discharged poler n relatively high.
Assessment of Fuzzy Measure Possibility for the Electromagnetic Field of unbalanced two coupled Three-phase Transmission line Considering toad-Voltage Characteristics
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 45~52
This paper presents a study on the assessment of fuzzy measure possibility for the electromagnetic field of unbalanced system. It takes into account m untransposed transmission line and unbalanced load. A three phase load flow program was developed which employs a Newton-Raphson method as a tool to analyze system unbalanced. This research presents a method of handling two coupled three phase transmission system unbalance analysis and unbalanced power demand as a function of voltages. In assessment of fuzzy measure possibility for the electromagnetic field, this paper use probability of fuzzy and measure of fuzziness technique.
An Assessment of Electric Shock Hazard by Safety Criteria Using Graphical Method
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 53~60
This paper presents a graphical method for hazard assessment of electric shock by safety criteria. For the human body to be safety actual body current should not exceed safety criteria, i.e. allowable body current. The assessment method presented in this paper is based m the safety criteria of the IEEE Standard 80 as well as the IEC 479-1. The hazard can be assessed in terms of alterable touch voltages instead of alterable body current. Thus, the hazard assessment of given electric shock condition is referred to a procedure by which the actual touch voltages are compared with the allowable (safe) touch voltages. Since the IEC 479-1 safety criteria are nonlinear, the graphical method is presented for the hazard assessment. Body current and body voltage are calculated with the allowable touch voltage. A comparison of the safety criteria of two widely accepted standards, i.e. the IEEE Std 80 End the IEC 479-1 is proposed. Also Thevenin equivalent resistance is obtained from electric shock model expressed by two-port earth-grid-foot system. On the basis of calculated results, the allowable touch voltage, the body current and the body voltage we can conduct the hazard or safety assessment and estimate the severity of electric shock.
Effect of Plasma Surface Treatment on Electrical and Mechanical Properties of Poly(ethylene terephthalate ) Film
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 61~67
In this study the electrical and mechanical characteristics of PET films ore analyzed after plasma surface treatment. After plasma treatment, the surface potential decay, surface potential and dielectric property were evaluated to analyze the electrical insulating property, and the tensile strength was measured as the mechanical characteristic. When plasma treatment was conducted for less than 10 minutes, it was found that the electrical insulating property was improved through evaporation of low molecular weight materials md cleaning of surface. However, for more than 10 minutes, the insulating property of plasma treated PET films was decreased due to excessive discharge energy. The tensile strength was hardly changed by Plasma treatment.
A Characteristics of Environmental Fraternitive Photopolymerization and Thermal Degradation on Methyl Methacrylate
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 68~75
Photopolymerization, the utilization of electromagnetic radiation(or light) as the energy source for polymerization of functional monomers, oligomers is the basis of important commercial processes with broad applicability, including photoimaging and RV curing of coatings and inks. The objective of this study is to investigate the characteristics of environmental fraternitive photopolymerization of methyl methacrylate(MMA). This work is the first step to continue further research about alkyl methacrylate. The experiment was done in aqueous solution under the influence of photo-initiator concentration(0.05-0.25mol/l), light intensity (5000-9000
) and monomer concentration(2-6mol/l). Methyl methacrylate was polymerized to high conversion ratio using hydrogen peroxide(
) and the kinetics model we have obtained is as follows.
). The differential method of thermogravimetric analysis(Friedman method) was used to obtain value of activation energy on decomposition reaction. The average value of it res 45.4Kca1/mol.
A Photocatalytic Degradation of Synthetic Detergent over
Catalysts Prepared by Sol-Gel Method
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 76~82
An aqueous solution of a commercial liquid synthetic detergent for kitchen use was photodecomposed in the presence of titanium dioxides ponder under an atmosphere of air at room temperature. Titanium dioxides were prepared by sol-gel method from titanium iso-propoxide at different R R ratio(
/titanium iso-propoxide) and calcined at
. All titanium dioxides m characterized by XRD, BET surface area analyzer and UV-VIS spectrometer. The surface mea of titanium dioxides prepared at R ratio=6 appeared higher volume about 20% than commercial
catalyses. XRD patterns of titania particles were observed mixing phase together with rutile and anatase type. Titanium dioxides prepared by sol-gel method show higher activity about 6% than commercial
catalysts on the Photocatalytic foundation of a commercial liquid synthetic detergent for kitchen. The concentration of the detergent decreased to about 90%, of its initial value at illumination times of 2 hour. illumination for 30 minutes decreased the concentration of oxygen to about one-fifth of the initial value.
A Study on Autoignition Characteristics of Methylmethacrylate-butadiene-styrene Copolymer
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 83~88
This study was preformed by measuring the minimum ignition temperature of MBS according to the change of sample vessel size and the minimum ignition temperature of MBS dust cloud The minimum ignition temperature of MBS product decreased as the vessel size was large, and it was obtained in the range from
and the apparent activation energy was obtained with 32.94Kcal/mol. The minimum ignition temperature of MBS dust cloud was measured by using Godbert-Greenwald furnace and it was obtained at
with the sample of 0.4g in the air and the ignition of dust cloud was not occurred below 13% oxygen concentration.
Experimental Study on the Behavior of Psudo Circular Concrete Column
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 89~98
There have been a lot of studies about repair & strengthening of the concrete structure. But there has almost not been my study on section damage effect due to holes drilled out for installing additional facilities or equipment, such as rack on the wall of building or underground culvert system, plumbing system through the column or wall of it, after being occupied. This study is to find out how much the section loss due to holes will give loss of section strength. We cm determine if we repair or reinforce it completely or not, using strength loss from the hole. Hole size of diameter 3cm, 2cm, lcm, depth of 3cm, 5cm, 10cm, and position of each hole has been considered as variables of this study. It is concluded that section loss 30% results in 53% of strength damage.
Characteristics of Bearing Capacity for H pile by Model Test
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 99~105
This paper presents results km a series of model tests oil vertically loaded single piles to compare the behaviors of H and pipe piles under the same ground condition. The aims of this paper were to compare the bearing capacity of H-pile md pipe piles under in the same ground condition and to estimate the effect of gravity acceleration and relative soil density. Relative density of soil were made to be 40%, 80% and embedded length of pile on sand was increased by 10, 12, 14, 16 times of the diameter of pile, respectively. As a results of test series, allowable load of H-pile is from 6.4% to 18.2% larger than allowable load of pipe pile in relative density 80% and from 9.1% to 39.4% larger than allowable load of pipe pile in relative density 40%. As a results of numerical analysis, we were predicted behaviour of stress-displacement of pile with model test. In the case of relative density 80% and 40%, bearing capacity of H pile represent from 17.74% to 18.6% larger than allowable load of pipe pile.
Industrial Accident Costs and Heinrich Method
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 106~110
For the policy makers and managers as well as the workers at work, it is important to identify what affects, to what extent, the safety level and costs of work sites. Within this context, the author analyzes fifteen construction work sites of the Incheon International Airport from 1996 to 1999 and shows that the expenditures for safety personnel and education programs contribute to reducing industrial accident costs. In addition, the author demonstrates that the regression analysis out-performs Heinrich method in estimating the accident costs of those work sites.
A Study on the Benefit cost Analysis of the Safety Cost in Construction Work
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 111~116
This study is conducted to review the ratio of direct and indirect cost accompanied by industrial accident in construction sites. It is surveyed that how to use safety cost in construction work is most efficient in comparison with several items of safety cost through the regression analysis.
A Framework for the Support of Predictive Cognitive Error Analysis of Emergency Tasks in Nuclear Power Plants
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 117~124
This paper introduces m analysis framework and procedure for the support of the cognitive error analysis of emergency tasks in nuclear poler plants. The framework provides a new perspective in the utilization of influencing factors into error prediction. The framework can be characterized by two features. First, influencing factors that affect the occurrence of human error me classified into three groups, i.e., task characteristic factors(TCF), situation factors(SF), and performance assisting factors(PAF). This classification aims to support error prediction from the viewpoint of assessing the adequacy of PAF under given TCF and SF. Second, the assessment of influencing factors is made by each cognitive function. Through this, influencing factors assessment and error prediction can be made in an integrative way according to each cognitive function. In addition, it helps analysts identify vulnerable cognitive functions and error factors, and obtain specific nor reduction strategies. The proposed framework was applied to the error analysis of the bleed and feed operation of nuclear emergency tasks.
Reliability Evaluation for the Advanced Pressurized water Reactor 1400
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 125~134
The Advanced Pressurized rater Reactor 1400(APR1400) system is advanced of the successful Korean Nuclear Power Plants(KSNP) design which meets functional needs for safety enhancement reliability improvement, and control in the human-computer monitoring system. Therefore this paper describes the scoring model in order to justify the reliability and safety in APR 1400 under uncertainty. The structure of this paper consists of the human engineering, risk safety, quality function, safety organization management factors of the qualitative factors in chapter 2, and the expectation results of the normalized scoring model in chapter 3. Finally, the proposed reliability model have provided the technical flexibility not only for functional control fields but also for accidents protection systems in APR 1400 under uncertainty.
Frequency Spectrum and re Correlation with Cutting Mechanisms in Orthogonal Cutting of Glass Fiber Reinforced Plastics
Gi-Heung Choi ;
Journal of the Korean Society of Safety , volume 16, issue 3, 2001, Pages 135~142
This study discusses frequency analysis based on the frequency spectrum and process characterization in orthogonal cutting of Fiber-matrix composite materials. A sparsely distributed idealized composite material, namely a glass reinforced polyester(GFRP) was used as workpiece The present method employs a force sensor and the signals from the sensor are processed using the fast Fourier transform(FFT) technique. The experimental correlations between the different chip formation mechanisms and power spectrum me established. Effects of fiber orientation, cutting parameters and tool geometry on the cutting mechanisms me also discussed.