• Journal of the Korea Institute of Building Construction
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• v.6 no.3 s.21
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• pp.75-82
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• 2006

This study investigates the influence of various blending factors on cement paste fluidity and find out the most effective evaluation method of cement paste flow, comparing flow test apparatuses such as ring flow(R-F), flow cone(F-C) and mini slump(M-S). A viscometer also measures the rheology coefficients to secure faithful numerical data. Firstly, series I examines cement paste, affected by several cement products and mineral admixture types in the range of W/B 40%, ordinary fluidity, and W/B 30%, high fluidity. In this series, the three types of cement product depended on companies, are randomly used and the mineral admixture, such as fly ash, blast furnace slag and silica fume, are incorporated in the cement paste, in response to the ratio of 10, 20, to 30%, respectively. In addition, series II studies various chemical admixture types, affecting the cement paste. This series is carried out with manufacturing companies and component types in the range of W/C 30%, high fluidity. For the manufacturing companies, randomly four products are used and for the component types, polycaboxylate, melamine, naphthalene and lignosulfonate type are chosen. Test results showed that in the fluidity test of cement paste considering various types of blending factors, R-F exhibited similar tendency with F-C and M-S. In the analysis of consistency curves measured by viscometer, the fluidity evaluation method using flow test apparatuses was significantly effective, except for the some of the low fluidity specimens. In conclusion of this study, R-F was the most convenient, faithful and effective fluidity evaluation method of cement paste.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.5
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• pp.757-763
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• 2023

Major industrial accidents in which workers die due to fires or explosions while working at chemical substance handling workplaces continue to occur. Among the major industrial accidents that occurred between 2005 and 2021, the accident status by work situation and equipment was analyzed. Through analysis, it was confirmed that storage, reaction, and piping facilities were the main causes of the accident, and a self-checklist for each facility was developed. Verification was conducted through the supply and use groups to evaluate the suitability of the use, duties, and items of the self-checklist. The user group showed higher satisfaction than the supplier group for all three suitability of use, job, and item. In particular, since the inspection items of the self-checklist were organized around the cause of the accident derived through the analysis of actual accident cases, the satisfaction level was high in all groups. It is expected that the self-checklist developed through this study will be useful not only for large companies but also for small and medium-sized chemical industries that lack professional manpower.

• The Journal of the Convergence on Culture Technology
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• v.3 no.3
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• pp.43-49
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• 2017

The purpose of this study is to study the standardization of the core business process in the chemical manufacturing industry and to establish a production information management system for the purpose of establishing the production information management system that can achieve mid -To be applied. The development methodology for the standardization of the chemical manufacturing information system is applied to the production information management system development methodology (PSDM) that was developed and developed by the Agency for Technology and Information Promotion of Small and Medium Enterprises. The standardization target is the system structure, It is a core business process that becomes a skeleton during construction. In this study, the chemical manufacturing SMEs and related professional IT companies who want to build the production information management system can apply the standardized core business process more effectively to build the system more effectively, and provide ease of installation and reliability to the system, In order to maximize the utilization of processes, follow-up education training and maintenance measures are suggested. Applying the results of this study, it is possible to eliminate the unreasonable elements of the production process, improve the quality of production product, and reduce production cost.

• Elastomers and Composites
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• v.52 no.1
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• pp.48-58
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• 2017

Thermoplastic elastomers (TPEs), a unique class of polymers, combine the processing ease of thermoplastics with the advanced properties of thermoset rubbers. TPEs can be remelted several times without any significant loss of properties, and can be molded into complex shapes using conventional processing equipment. Due to their characteristics, TPEs are ideal for use in a variety of applications in the automotive field. Although the TPE market of the Republic of Korea is currently at its niche, the increasing manufacturing push from major companies is expected to open up multiple opportunities for these products in the automotive sector. This manuscript highlights a detailed technological trend of the global automotive thermoplastic elastomers market.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.3
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• pp.179-189
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• 2001

This study was performed to identify the current status of work environment management and to provide appropriate recommendations for small scale industry with less than 5 workers from September, 2000 to October, 2000 in Seoul city and Gyoung-gi province. The 211 companies were surveyed by checklist included the elements of management of work environment, hazardous chemicals, MSDS, personal protective equipment, and ventilation system. The proportion of metal products manufacturing and printing industries are 25.6 % and 22.3%, respectively. The daily working hours in printing industry is longer than others. The industries that produce potentially hazardous agents, such as noise, dust, metal, organic solvents, radiation and chemical material are pulp, plating, machinery, and printing, respectively. In above industries, only 2.8 % of those recognised and had MSDS. The proportion of companies providing fire extinguishers, safety showers are found to be 13.3 %, 7.1 %, respectively. Only 24.2 % of companies provided personal protective equipment to the workers. The ventilation system was operated in most of companies. But local exhaust ventilation system is provided to 22.3 % of those, also had not been annually inspected. This study showed that the current status of occupational safety and health was not appropriate for workers in small scale industries. It is suggested that annual physical examination have to be performed, MSDS usage must become widespread, and employer and emplyees in small scale industry should be educated for the treatment and storage of hazardous chemicals to improve the occupational safety and health of the working environment. also, regulatory standard has to be applied to local exhaust ventilation system in small scale industry to improve the working condition.

• Membrane Journal
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• v.1 no.1
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• pp.5-12
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• 1991

Since the discovery of the Loeb-Sourirajan reverse osmosis membrane, thirty years have passed and many membrane technologies and new membranes for applications have been developed in the world. In the early stage of these developments Japan has not contributed much, but from the middle of 70ties Japan has started its own R&D projects starting from the desalination technology, and now various private industries and government ministries are actively engaging in R & D of membrane technologies in Japan. In Table 1 the chronological developments of important events of developments and projects relating membrane technologies inside and outside of Japan are introduced and their details will be explained. The first membrane technology applied in the Japanese industry was a electrodialysis(ED) process using ion-exchange membranes. These membranes were first developed in early 50ties and the Japanese government decided to use this method for concentration of sea-water to produce salt, which was then produced by solar evaporation. This development program started from 1960 by the Japan Monopoly Corp.(at that time). To apply ED process for sea-water concentration it was necessary to develop ion-exchange membranes having very low electric resistance to avoid energy loss due to Joule heat, and those having selectivity to permeate single valent ions only to avoid scale formation in the ED stacks. Three Japanese companies, Asahi Glass, Asahi Chemical and Tokuyama Soda, have succeeded to develop such membranes, and until 1971 all of the seven salt manufacturing companies had adopted ED for production of food salt.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.1
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• pp.71-79
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• 2021

This study investigates the capital structure policy among Indonesian public companies. Previous studies suggest that capital structure policy could follow either static or dynamic behavior. The sample data used in this study was companies in the manufacturing sector, divided into three sub-sectors: the basic and chemical industry, miscellaneous industry, and the consumer goods industry. This study uses panel data from 2010 to 2018, with the Generalized Least Square (GLS) method and compared whether the fixed effect model is better than the common effect model. The results show that the dynamic and non-linear model tests can explain the capital structure determinants than the static and linear models. The dynamic model shows that the capital structure of a certain year is influenced by the capital structure of the previous year. The findings indicate that the company performs some adjustments in its capital structure policy by referring to the previous debt ratio, which implies support to the trade-off theory (TOT). The study also shows that profitability, tangible assets, size, and age explain the variation of capital structure policy. The patterns on the dynamic and non-linear confirm that capital structure runs in a nonlinear pattern, based on the sector, company condition, and the dynamic environment.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.2
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• pp.43-54
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• 2014

Environmental pollution including air, land, and water has become one of the most critical issues in global interest. The damages due to environmental pollution lead to serious disasters. Nations have realized the importance of environment protection and have been starting to force organizations to implement environmental management system (EMS) as way of protecting environment. ISO 14001 requirements that are the most popular standard as EMS have been developed to support continuous improvement to environment management. It has been revised once since publication and ISO 14001 : 2004 version is currently available. Organizations globally started to acquire the certificate of EMS to observe environment related laws, accept customers' and stakeholders' request, increase market share, and fulfill implementation motives. This article examines the audit data that were collected for several years from manufacturing companies including shipbuilding, machinery, metal, automobiles, and chemical companies in southeastern Korea on the basis of ISO 14001 : 2004 requirements. The audit data were classified into minor nonconformities based on factors such as business size, business type, and EMS implementation period. We conduct hypotheses test using statistical methods in order to see if there are any significant differences based on the factors. We draw conclusions for the results of hypotheses test and address the necessities of energy, greenhouse gas, green management, and continuous improvement to enhance the efficiency of EMS implementation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.129-132
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• 2003

Used cutting fluid from machining processes is harmful to both environment and human health. Chemical substances that provide the lubrication function in the machining process are toxtc to the environment if the cutting fluid is released to soil and water and caused serious health problems to workers who are exposed to the cutting fluid in both liquid and mist form. Recently. cost of using cutting fluid is increasing as the number and the extensiveness of environmental protection laws and regulations increase. Therefore, the use of cutting fluid in machining processes place an enormous burden on manufacturing companies to cover the additional costs associated with their use and protection of our environment. Current trends in manufacturing are focused on minimizing or eliminating the use of metalworking fluids in machining processes. And the increased costs for the disposal of waste products (swarf, coolants and lubricants), especially in industrially developed countries, has generated interest in dry machining. A variety of new techniques are testimony that new technology has rationalized further efforts to research and implement dry machining processes. This paper presents the developed equipment, the process optimization and the applications in the field of surface grinding for the new cryogenic dry machining using a compressed cooling air. The investigated new machining process method shows many advantages compared to conventional techniques with cutting fluid.

• Journal of the Economic Geographical Society of Korea
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• v.5 no.2
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• pp.137-155
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• 2002

The purpose of this study is concerned with the relationship between the location of industrial complex and regional changes. Yeochon National Industrial Complex(YNIC) was dedicated as an industrial site in 1967 according to a part of the Korean government's plan of developing for heavey chemical industry. Yeochun city has been changed with location and establishment of YNIC since 1969. The establishment of YNIC have influence upon the increase of population and employment, urban development, and growth of regional economy within research areas including of Yeochun city, Yeochun county, and Yeosu city. In addition, with the establishment of YNIC, the regional economical structure was progressed from farm and fishery oriented sector to manufacturing oriented sector, thus the petrochemical business related companies hold a majority among regional manufacturing structure. We used the shift-share analysis and regional growth rate differential analysis in order to examine the characteristics revealed in the transformation of employment and industrial structure. The petrochemical related manufacturing and construction industries provided a great influence on the growth of regional employment.