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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
Editor in Chief :
Volume & Issues
Volume 18, Issue 4 - Dec 2003
Volume 18, Issue 3 - Sep 2003
Volume 18, Issue 2 - Jun 2003
Volume 18, Issue 1 - Mar 2003
Selecting the target year
An Evaluation on the Fatigue Strength Characteristics for the Shot Peening Spring Steel at Low Temperature
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 1~7
In this study, CT specimens were prepared from spring steel(SPS5) processed shot peening. The fatigue crack growth tests were carried out in the environment of the room temperature md low temperature at
in the range of stress ratio of 0.05 by means of opening mode displacement. The threshold stress intensity factor range ΔKth in the early stage of fatigue crack growth (Region I) and stress intensity factor range
K in the stable of fatigue crack growth (Region II) were decreased in proportion to descend temperature. It was shown that the fatigue resistance characteristics and fracture strength at low temperature are considerable higher than those of mom temperature in the early stage and stable of fatigue crack growth region.
A Study on the Electroviscous(EV) Fluid Squeeze Film Damper(SFD) Bearing of the Truncated Cone Type
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 8~13
Equivalent Reynolds equation of truncated cone type SFD bearing using nonnewtonian EV fluid is derived. The 3 nondimensional oil film pressures and its forces are obtained with axial and circumferential pressure gradient of bearing respectively, and dynamic characteristics for the stability of rotor-bearing system are obtaind through the governing equation for an elastic rotational shaft. It is shown that EV fluid is less sensitive to the changes of oil-film than newtonian fluids for dynamic characteristics. Therefore, results show that it is better to use an EV fluid with truncated cone type SFD bearing for the vibration control of rotational machines.
A Study on the Influence of Ceramic Coating on Characteristics of Friction and Abrasion of Aluminum Alloy(7075 T6) Used in Mechanical Casting
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 14~21
This study deals with the influence of ceramic coating on characteristics of friction and abrasion of aluminum allot(7075 T6) used in mechanical casting. In this research, frictional wear characteristic of ceramic coating materials such as
, SiC was investigated using aluminum alloy(7075 T6) and stainless 403 cast iron under room temperature and normal air pressure. The coating layer was observed using SEM. The conclusions are as follows: 1) Friction coefficients of
, SiC and
are obtained 0.63 0.56 and 0.54 respectively. 2) Abrasion resistance of stainless 403 cast iron with
is the best among the ceramic coating materials. 3) Abrasion mechanism of aluminum alloy(7075 T6) coaled with ceramic material and stainless 403 cast iron is caused by brittle fracture. 4) Coating the ceramic material on the aluminum alloy(7075 T6) can effectively increase the antiwear, impact properties, and corrosion resistance.
Construction of Chaos Simulator for Cutting Characteristics Evaluation of Non-Ferrous Metals
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 22~28
This study proposes the construction of chaos simulator for cutting characteristics evaluation of non-ferrous metals. Also this paper aims to find the optimal cutting conditions of diamond turning machine by measuring surface form and roughness to perform the cutting experiment of non-ferrous metals, which are aluminum, with diamond tool. As well, according to change cutting conditions such as fled rate, using diamond turning machine to perform cutting processing, by measuring cutting force and surface roughness and according to cutting conditions the aluminum about cutting properties. Trajectory changes in the attractor indicated a substantial difference in fractal characteristics. Constructed chaos simulator in this study can be used for cutting characteristics evaluation of non-ferrous metals.
Evaporation Cooling of Droplet due to Surface Roughness
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 29~33
The objective of the present work is to examine evaporation cooling of droplet due to surface roughness on a heated surface. The surface temperatures varied from 80-
on aluminum alloy (AL 2024) md surface roughness was 0.l8
. The results are as follows; Regardless of surface roughness, as droplet diameter is bigger, the in-depth temperature of solid decreases and evaporation time increases. In the case of same initial temperature on the heated surface, as droplet diameter is smaller and small surface roughness is bigger, evaporation time decreases and time averaged heat flux increases.
A Study on Smoke Movement by Using Large Eddy Simulation II. Smoke Control Systems and Opening Size
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 34~38
The large eddy simulation based Fire Dynamics Simulator was utilized to investigate the effects of the size of an opening on smoke removal performance for the three smoke control systems-ventilation purge, and extraction. Three different opening sizes,
=1, 2, and 3 were investigated while the flow rate remained 0.75
at the inlet or outlet depending on the systems. Increase of the opening size did not give a significant difference in the smoke removal rate for the three smoke control systems, though the increasing opening size slightly improved smoke removal. The extraction system was shown the best smoke control system, and the purge system yielded low performance compared to the other two systems for all the different opening sizes.
Evaluation on Failure Characteristics of the Local Wall Thinning Elbows Using Three Dimensional Finite Element Analysis
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 39~45
The failure mode of a pipe due to local wall thinning is increasingly more attention in the nuclear power plant industry. To assess the integrity of locally wall thinned pipe, it is necessary to perform many simulations under various conditions. Because the modeling for locally wall thinned elbow is more complicated than that of straight pipe the efficient modeling method for finite element analysis is necessary. In this study, the more simple efficient modeling method of three-dimensional finite element analysis for locally wall thinned elbow has been suggested and verified. And using the method, the failure mode of local wall thinned elbows that have different thinning lengths and circumferential angles is evaluated. From the results, we concluded that the collapse load of elbows has been decreased by the increase of wall thinning shape factors such as thinning lengths and circumferential angles
The Notch Effects on the Fatigue fracture Behaviour of Ferrite-Martensite Dual Phase Steel
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 46~53
For the tensile tests of the F.E.M., microvoids are created by the boundary separation process at the martensite boundary or neighborhood and at inclusions within the fracture. to grow to the ductile dimple fracture. For the case of the M.E.F., microvoids created at the discontinuities of the martensite phase which exists at the grain boundary of the primary ferrite are grown to coalescence with the cleavage cracks induced at the interior of the ferrite, which as a result show the discontinuous brittle fracture behavior. In spite of their similar tensile strengths, the fatigue limit and the notch sensitivity of the M. E.F. is superior to those of the F.E.M., The M.E.F. is much more insensitive to notch than F.E.M. from the stress concentration factor(
Electrostatic Discharge Energy Estimation of the Charged Human Body by the Rompe-Weisel Model
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 54~59
The discharge energy by electrostatic discharge of the charged human body is calculated under the assumption that the stored charge is dissipated completely. However, it is well-known that the charge is slightly remained after electrostatic discharge. Therefore, The Rompe-Weisel model of the discharge analysis, which has somewhat more of a physical justification than the conventional energy equation, is proposed. It is proposed that the electrical conductivity of the arc should be proportional to the energy density transferred to it by Ohmic dissipation. For the electrostatic discharge energy analysis, the Rompe-Weisel model was compared by quasi static analysis. As a consequence, a study on a reliable energy evaluation based on simulation models during electrostatic discharge is carried out in this paper and is adopted to estimate the explosion hazards of flammable gases.
A Study on the Way to Increase Heat Resistance of Teflon Type Thin Film Electret Applied for Industrial Sensor
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 60~63
For the increase the charge stability of teflon electrets for used at uncomfortable industrial circumstances with high temperature or humidity, We made an investigation into double layer effect of teflon electrets. Teflon AF film was spincoated on FEP film and then the charge storage property of AF/FEP dual film was investigated to be compared with FEP film. It was found that the AF/FEP dual film has higher surface potential than FEP film on the repeated charging and annealing process. It seems that AF/FEP dual film has higher thermal stability than FEP film through TSC measurement. If the investigations of the double layer effect of Teflon film carried out more closely with it's molecular structures and surface conditions, it may be effectively improved the stability of charge storage.
Annealing Effect on the Electrical Characteristics for Oxide Semiconductor
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 64~68
solar cell is fabricated by vaccum deposition method under the resistance heating with substrate temperature kept about 200[
] and than their properties are investigated. The maximum output of fabricated solar cell is obtained when the composition of the thin film is consisted of indium oxide 91[mole %] and tin oxide 9(mole %). The solar cell electrical charateristics can be improved by annealing but are deteriorated at temperature above 600[
] for longer than 15[min].
Influence of Partial Discharge Properties due to Void in Cable Joint Parts
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 69~74
To investigate the partial discharge and electric field distribution in cable joint parts, we measured the partial discharge and electric field in specimen. The specimens which cross-linked polyethylene(XLPE) and ethylene propylene diene ethylene(EPDM) are used to insulating material for underground cable md cable jointing parts. The polymers are used to insulating material in switchgear which is a kind of transformer equipment and in ultra-high voltage cable. Its using is increasing gradually, the electrical insulation properties are not only excellent but also mechanical property is excellent. And because it is possible to be made void of several type in insulator while it is produced, which the electrical field distribution is changed by void, it has a critical influence to insulator performance. The underground cable is connecting by the jointing material, insulating breakdown and the electric ageing which are caused by several mixing impurity and the damage of cable insulator layer, which reduced the life of cable while intermediate joint kit is connected. Therefore, the computer simulation is used to estimating insulator performance, XLPE is used to the insulating material of ultra-high voltage cable and EPDM is used to insulator layer in joint material kit, and which are produced as specimen. And it is analyzed the electric field concentrating distribution and partial discharge by modeling of computer simulation in void and cable joint kit.
Typical Pseudo-accident Scenarios in the Petrochemical Process
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 75~80
This paper presents a set of typical pseudo-accident scenarios related to major equipments in petrochemical plants, which would be useful for performing such quantitative risk analysis techniques as fault tree analysis, event tree analysis, etc. These typical scenarios address what the main hazard of each equipment might be and how the accident might develop from an "initiating event". The proposed set of accident scenarios consists of total thirteen (13) scenarios specific for five (5) major equipments like reactor, distillation column, etc., and has been determined and screened out of one hundred and twenty-five (125) potential accident scenarios that were generated by performing semi-quantitative risk analysis practically for twenty-five (25) petrochemical processes, considering advices from the operation experts. It is assumed that with simple consideration or incorporation of plant-specific conditions only, the proposed accident scenarios could be easily reorganized or adapted for the relevant process with less time and labor by the safety engineers concerned in the petrochemical industries.ndustries.
A Consideration on Thermal Stability of the PVAc Latex Adhesive
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 81~87
Latex polymers are widely used for adhesive, binder, paint etc. Especially the PVAc(Polyvinyl acetate) latex which manufactured by vinyl acetate and vinyl alcohol as protective colloid is a useful environmentally friendly adhesive. To increase useful property of PVAc latex, this study was carried out for checking thermal characteristics and physical condition of PVAc latex by DSC, FT-IR, Pyrolyzer GC-MS. The activation energies of thermal decomposition for 40, 48, 56, 64% solid content of PVAc latex were found as 28.1-36.0kcal/mol by Kissinger's method and 17.2-22.0kcal/mol by DSC method. Actually, reasonable solid content could be consiered as 56% because of activation energy and adhesive characteristics. According to the effect of protective colloid for 4, 10, 15, 20wt%, the activation energy shows same tendency to both method and in case of l5wt% has been found as the highest activation energy. The mechanism of thermal decomposition was mainly estimated by main chain scission, not by side group on FT-IR analysis. Main component of Pyrolzer GC-MS result were consisted of
and light gases(CO,
Research on the Prevention of Major Industrial Accident By Integrated Risk Management System
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 88~93
The Process Safety Management (PSM) by the Law of Industry, Safety and Health has been performed for preventing major accidents of chemical plants since 1996. In terms of preventing chemical accidents more precisely, it is essential to develop a tool for quantitative risk assessment. For this, KOSHA (Korea Occupational Safety and Health Agency) developed an Integrated Risk Management System (IRMS). The system is designed to assimilate data on chemical plant hazards from external database, to integrate these data with location information(topographic and demographic), and to make them user-friendly accessible. The system consists of several main functions: display of five major Korean petrochemical complex layout display of equipment layout with its information utilizing the external database, zonation of the hazard effected area with consequence analyses, the most probable accident scenario generation, accident/incident database and calculation of frequency of accident using equipment reliability database, etc. The highlight of IRMS is to provide the risk contours using GIS(Geographical Information System) technology. IRMS is intended to manage hazardous installation more systematically and effectively, to reduce the number of accident remarkably, further minimizing production loss in the plant. The system is now under application to about 500 PSM sites as well as and emergency authorities in Korea by KOSHA (Korea Occupational Safety and Health Agency)
Properties of Gel-like Compounds Containing Flammable Solvents
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 94~100
Gel-like compounds containing flammable solvents were prepared to use fur cleaning agents in field of innovative industries and general purposes. And experiments were conducted to improve the defects of liquified flammable solvents from the view point of safety and health hazards. Flammable solvents used in this study were several single component flammable solvents(turpentine oil, N-methyl-2-pyrrolidone(NMP), d-limonene) and multi component flammable solvent(gasoline and ethanol). For gelation of flammable solvents, commercially Known as Aerosil(equation omitted) 200 fumed silica and triethanolamine(TEA) were used as gelation agent dispersant. The analyses on properties of gel-like compounds was studied by gelation and viscosity test pH test, volatility test and differential scanning calorimetry(DSC) measurement. The experimental results indicate that gel-like compounds containing flammable solvents have pH stability, high viscosity, volatile organic compounds(VOC) control by the decrease of volatility and odor component generation, fluidity control etc. From the experimental values, it can be predicted that the safety in the working place is improved by manufacturing flammable solvents into gel-like compounds.
Preparation and Properties of Polymer PTC Composites for Process Safety
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 101~108
Polymeric positive temperature coefficient(PTC) composites have been prepared by incorporating carbon black(CB) into high density polyethylene(HDPE), polyphenylene sulfide(PPS) and polybutylene terephthalate(PBT) matrices. A PTC effect was observed in the composite, caused by the large thermal expansion due to He consecutive melting of HDPE, PPS and PBT crystallites. This theory is based upon the premise that the PTC phenomenon is due to a critical separation distance between carbon particles in the polymer matrix at the higher temperature. The influence of PTC characteristics of the PPS/CB composite can be explained by DSC result. HDPE, one of prepared composition, exhibit the higher performance PTC behavior that decreaseing of negative temperature coefficient(NTC) effect and improved reproducibility by chemically crosslinking. Also, PBT/CB and PPS/CB composites exhibit the higher PTC peack temperature than HDPE/CB PTC composite, individually
. These PTC composite put to good use in a number of safety application, such as self
controlled heater, over-current protectors, auto resettable switch, high temperature proctection sensor, etc.
An Experimental Study on the Effect of Accelerator and Chemical Admixture Type for the Durability of Shotcrete
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 109~113
Concrete and shotcrete should withstand the conditions for which they have been designed, without deterioration, over a period of years. But connote and shotcrete are being deteriorated according to aging by internal and external causes. Recently, many studies on the durability of concrete have been conducted But the durability of shotcrete is rarely studied. So, in this study, chloride ion penetration test freeze and thaw test neutralization test were conducted to examine the durability characteristics of shotcrete with several accelerator and chemical admixture types. These results indicate that shotcrete with allah free accelerator and with superplasticizer are durable. Therefore, the present study provides a fm base to make high performance shotcrete.
Investigation on the Service life of Disappeared Buildings in Busan
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 114~119
The building needs of the community are met by the interrelated construction activities of maintaining, modernizing and replacing the existing stock of building and by the erection of additional new building. Studying the service lift of buildings and how it is determined can serve as an important measuring stick in making decisions on construction policy. Therefore, the purpose of this study is to provide useful information for future construction through a comparative and analytical study of building structures on disappeared buildings. It was found that most building structure had a shorter service life than the standard set by The Korea Appraisal Board. This situation may have occurred due to the sharp rise in replacement of older buildings with new buildings for the purpose of monetary profit. To increase the economic life of buildings reduce losses of the nation's capital henceforth, examination on policy md steady study needs to be done.
An Analytic Hierarchy Process on the Cause of Gun Powder Blasting Accicdent
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 120~125
This research analyzes blasting accident cause that is happening construction and engineering works spot taking advantage of AHP (Analytic Hierarchy Process) techniques as metrical. Result that apply AHP with blasting accident that is happened the South Korea and Japan, appeared by thing which relative importance by human cause is highest. Specially, it is observance of safety rule that dominate the highest ratio among of human cause, and if observe a little, causes that prevention is possible are much. By result of this research, necessity of safety education is important first of all for prevention of blasting accident. Also, thorough safety control plan of during work and enough on-the-slut probe before work should be established. Because explosives uses gunpowder and explosive high energy, work by qualified person is essential. Ant it may become help to minimize dissipation of important life and property preventing beforehand explosion accident of gunpowder.
The Development of the Korean Life Change Unit Model for Accident Prevention -Focused on the Unmarried Workers Living in the Middle Area-
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 126~130
The term stress is currently used to cover a wide variety of phenomena, ranging from physical to social and cultural factors. The term has defined psychological stress as an imbalance between perceived or subjective demand and perceived response capability. The behavior science model has provided the accident proneness through the life change unit factors considering human behavior, life style, ideas, culture, and psychological state. Therefore, this paper presents the Korean life change unit model through statistical testing with the proposed life change unit factors on the unmarried workers living in the middle area. The proposed model can be simply used in real fields in order to minimize the industrial accidents.
Cause Analyses of Boiler Accident and Their Counter-plans Based on Accident Cases
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 131~140
An accident involving a boiler can result in a disaster since it handles high-pressurized steam so that it may cause an explosion. Therefore, the boiler is very susceptible to industrial accidents. This thesis aimed to develop counter-plans to prevent industrial accidents involved the boiler. At first after collecting accident cases involving boilers, a survey on the trait of them was carried out. Ant on the other hand a qualitative analysis was conducted to draw out hazardous components in the boiler itself and their inherent relative importance was assessed. Through this procedure, 'negligence of unsafe condition' was noted as the major cause for unsafe acts whereas 'fault in work procedure' for unsafe condition. In the meanwhile, results of a hazard analysis using FMEA technique ranked gas safety devices, a switch preventing gas from under-pressurization, protect relays high. In particular, it was pointed out that the water feeding and steam subsystem has more components in hazard than other subsystems. Considering these analyses results, counter-plans to improve safety management was suggested also.
A Study on the Risk Analysis Techniques for Products: Development of HuBRA (Human Behavior Risk Analysis)
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 141~148
Since the introduction of The Product Liability Law, effective since July 2002, more and more companies and end-users have been giving their attention to the safety of products. A number of existing risk analysis techniques are being implemented to manufacturing sites. However, they have certain restrictions such as incurring different techniques that are to be implemented at each stage of the product development. This is due to their domain of the analysis differing from one to another. Moreover, the results of these analyses are not specific enough, and are subject to further revision. This study proceeds to look at various examinations undertaken on the existing risk analysis techniques. Through implementing them on certain products, investigations on the strengths and weaknesses were ascertained. This has allowed improvements on the existing techniques to be achieved as tell as the development of a new risk analysis technique, 'HuBRA(Human Behavior Risk Analysis)'. Finally the new technique was implemented on products to confirm its effectiveness.
A Study on Managerial System of Work-related Musculoskeletal Disorders
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 149~153
Recently, work-related musculoskeletal disorders(WMSDs) are one of major issues in occupational safety and health in Korea. Main risk factors of WMSDs include manual handling of heavy weight loads, awkward posture, repetitive tasks, Prolonged static muscle contraction, and so on. The number of injured workers has rapidly increased and the related regulation was amended to improve the work conditions and environments. And demands for workers' compensation and improvement of work conditions and environment to prevent WMSDs have increasingly been raised. This study focused on managerial system to prevent WMSDs. Literal survey and questionnaire survey were accomplished to propose a management system in Korea for preventing WMSDs.
Real-time Distributed Control in Virtual Device Network with Uncertain Time Delay for Predictive Maintenance (PM)
Kiwon Song ; Gi-Heung Choi ;
Journal of the Korean Society of Safety , volume 18, issue 3, 2003, Pages 154~160
Uncertain time delay happens when the process reads the sensor data and sends the control input to the plant located at a remote site in distributed control system. As in the case of data network using TCP/IP, VDN that integrates both device network and data network has uncertain time delay. Uncertain time delay can cause degradation in performance and stability of distributed control system based on VDN. This paper first investigates the transmission characteristic of VDN and suggests a control scheme based on the Smith's predictor to minimize the effect of uncertain varying time delay. The validity of the proposed control scheme is demonstrated with real-time velocity control of DC servo motor located in remote site.