Stainless steel Arc welding fume의 흡입독성 연구

송경석 성균관대학교 산업과학대학원 1998 국내석사

In order to investigate welding fume exposure related occupational diseases such a s nasal septum perforation, pneumoconiosis and manganese intoxication, an acute inhalation toxicity study of exposing male Sprague Dawley rats to the welding fume generated from stainless steel arc welding was carried out. Male Sprague Dawley rats were exposed to the welding fume with 61.56 mg/㎥ for 4 hrs in an inhalation chamber. Animals were sacrificed at 0, 1, 3, 7, 10, and 14 day after exposure. Upper respiratory tract including nasal pathway, conducting airway, and gas exchange region including alveolar ducts, alveolar sacs and alveoli were investigated through histopathological examinations. Following results were obtained: 1. The fume particles had various in their diameters ranging from 0.02 - 0.81㎛ and are distributed log normally with average diameter and geometric mean of 0.098 ± 1.42. 2. The rats exposed the welding fume for 4 hrs did not show any significant tonicities in blood biochemistry and hematology. 3. The average diameter 0.1㎛ resulted in fewer adsorptions of the welding fume particles in the upper respiratory tract. 4. The major sites for particle adsorption were the lower res-piratory tracts including brochioles, alveolar ducts, alveolar sacs, and alveoli. 5 . Long-term studies are needed for identification of occu-pational diseases caused by welding fume.

용접흄 吸入毒性試驗 裝置 開發에 관한 硏究

한규태 성균관대학교 산업과학대학원 1998 국내석사

In order to conduct inhalation toxicology on welding fume, welding exposure system including welding fume generator, exposure chamber, and fume collector were built. The welding fume exposure system was monitored and validated. The welding fume generated from stainless arc welding was characterized for its composition. The fume concentrations in the exposure chamber were monitored for their consistency. Following results were obtained. 1. Welding fume was generated consistently from the generator using a 2.6 mm diameter electrode (30 mm length) and a 500 mm diameter (10 mm thickness) stainless rotating disc. After consuming 250mm of 300mm electrode, the electrode was moved back and stopped to give intervals for changing the electrode. This movement was continuously repeated 'with 5 rninutes cycle. 2. An electric shock stopper was used to prevent electric accident and a deep blue plate was used to screen out hazardous light from the electric arc. 3. A digital velocity meter was installed on the duct and the velocity meter indicating 0.6 m/sec suggested that a continuous flow was supplied into the exposure chamber. The flow was 0.3 ㎥/min satisfying international standard. 4. When the fume concentrations in the chamber were monitored every 15 minutes during 2 hours of exposure, the fume concentrations were maintained consistently. In addition, major metal concentrations including Fe, Mn. Cr and Ni were also maintained constantly. 5. The chamber was able to expose 60 rats and contained brackets for placing animal cages. The animal excretions were stored in the container located in the bottom part of the chamber. 6. Damper and diffuser controlled flow rate. Remaining fume was filtered through the fume collector and onlt clean air was exhausted. Additional ventilation system was installed to protect researchers.

레이저프린터의 기술수준분석

이한철 성균관대학교 산업과학대학원 1998 국내석사

This study aims to measure the technical performance of laser-beam printers based on the scoring model, which was developed by J.Martino. Variouse functional parameters of the printers produced by Hewlett-Packard and Xerox in US, Canon and Okidata in Japan, and A laser printer manufacturer (which wants to be anonymous) in Korea were measured and compared. State of the art(SOA) of laser-beam printer has rapidly increased in all companies. It also shows that SOA of low-speed printers' grows faster than that of high-speed printers and that the US printers' technical performance exceeds that of Japan at the time of market introduction. But when the printers of equivalent performances are compared, the introduction times of the Korean printers are mostly delayed compared with thoses of US printers. It is hoped this study will be helpful to planning the techological development in the laser-beam printer industry in Korea.

鎔接흄에 대한 防塵마스크의 濾過效率에 관한 연구

권용식 성균관대학교 산업과학대학원 1998 국내석사

Using welding fume generator and exposure chamber, several dust masks were for their filtration efficiency. Several dust masks, which were used widely in the workplaces, were collected and tested for their filtering efficiency for welding fume. The filtration efficiency testing system consisted of a welding fume generator, exposure chamber and a filtration test unit. The filtration unit was made of a mask containing sampling cassette and another sampling cassette, which contained MCEF filter paper. These two cassettes were connected with tubing. Welding fume generated from a stainless steel are welding fume generator was delivered into an exposure chamber. The welding fume in the chamber was passed into the filtration unit with flow rate of 30 liter/min. The welding fume filtration efficiency was calculated and welding fume diameters before and after passing dust mask were evaluated by transmission electron microscopy. Metal concentrations in the welding fume before and after filtration were measured with inductive coupling plasma spectrophotometer. Following results were obtained: 1. The filtration efficiency of common cotton mask was 63.82 % ± 2.67 and the average efficiencies of A, B, C, D, E, F and G masks were 94.62 % ± 0.76, 96.58 % ± 0.99, 83.2 % ± 0.86, 82.76 % ± 1.67, 77.25 % ± 2.97, 96.55 % ± 2.34, and 93.22 % ± 0.61, respectively. 2. The average diameter of the weldmg fume was 0.1 [㎛], and the average diameters were changed after filtration, Average diameters of common cotton mask was 0.078 [㎛] ± 1.75 (0.033∼0.367 [㎛]) and A, B, C, D, E, F, and G mask were 0.049 [㎛] ± 1.710 (0.020∼0.160 [㎛]), 0.044 b3 ± 1.660 (0.020∼0.180 [㎛] ) , 0.060 [㎛] ± 1.60 (0.025∼0.250 [㎛]), 0.056 [㎛] ± 1.633 (0.025∼0.175 [㎛]), 0.063 [㎛] ±1.541 (0.025∼0.175 [㎛]), 0.051 [㎛] ± 1.700 (0.010∼0.160 [㎛]), 0.046 [㎛] ± 1.78 (0.020∼0.240 [㎛]), respectively. 3. Our results indicate that dust masks, which have been used widly in the welding works, are not proper for protecting worker's health, thus the use of fume mask was required.

活生劑(Probiotics)添加가 肉鷄의 生産性 및 小腸內 微生物叢에 미치는 影響

김기원 成均館大學校 産業科學大學院 1992 국내석사

기체크로마토그래피법에 의한 흡연자와 비흡연자타액의 유기산 프로파일 연구

김정옥 成均館大學校 産業科學大學院 1994 국내석사

Rats에 BPMC를 投與에 의한 毒性에 관한 硏究

박승엽 成均館大學校 産業科學大學院 1992 국내석사

建設生産性 向上을 위한 建設業體의 對應 方案硏究 : 共同住宅(APT)을 中心으로

박영환 성균관대학교 산업과학대학원 1999 국내석사

Recently changes in external environment, including the needs of an IMF or unlimited competition age are presumed to impose lots of trials and dships on construction enterprises in Korea. In these contexts, domestic construction enterprises need varied coping strategies. They may include not merely a reduction of the term of work, a reduction of cost, saving of materials, and endeavors related to them but also researches in and efforts for the advancement of construction. In particular, we need to review first apartment housing that is deemed to be competitive by standing on the same position as foreign enterprises closely related to our practical living in the construction market. Unlike other construction markets, the apartment housing sector consists for the most part of simple, repetitious, and labor-intensive works. With this view in mind, this study put its principal objective on inquiries into the advancement of construction productivity centering around apartment housing. The methodologies depended upon data collection analysis and comparison. Resultant findings were revealed, as follows: For the advancement of construction productivity, we necessitate : 1) efficacious research efforts, 2) research in all aspects, apart from certain parts, and 3)data accumulation and arrangement via feedback. Coping strategies against mooted points were revealed, as follows; (1) The advancement of the managerial Sector - The systematization of work management - Improvements in organization - Introduction of knowledge bases (2) The Advancement of Technical Sector - Plans for the rationalization of construction work - The utilization of the VE technique - The introduction of mechanized robots

養豚 糞尿의 微生物學的 處理에 關한 硏究

강병곤 成均館大學校 産業科學大學院 1994 국내석사

There has been increasing interest in the treatment of Swine wastes which contribute the major portion of livestock wastes. Current techniques for the treatment of Swine wastes may include physical treatment, chemical treatment and biological treatment. However a great deal of efforts were directed to biological treatment method using microbial agents. In this study, characteristics of the Swine wastes were investigated and the treatment efficiency was tested using some of the commercial microbial agents. Microbial agents for the study included type C (mixture of cultured Chlorella and enzymes), type D (mixture of GRAS microbial agent and enzymes) type E (mixture of bacteria extracted from soil), type F (mixture of mutant bacteria and enzymes) and type H (mixture of facultative anaerobic bacteria and enzymes). The result revealed that some of the microbial agents were selectively effective in removing BOD(Biological oxygen demand), suspended solid(SS), total phosphorus(TP) and total nitrogen(TN). The treatment efficiency was greatly improved when microbial agents were coupled with aerobic process than microbiological or aerobic treatment alone. Type E and C showed good BOD removal efficiency of 90.14% and 87.06% respectively. In the meanwhile, type F proved to be effective in SS removal indicating 95.52% efficiency. Type of C, E, F, H and D were good microbial agents for treatment of the Swine wastes and more efficient than other types of microbial agents.

콩나물에 含有되어 있는 Benzimidazole系 殺菌劑의 HPLC에 의한 分析 硏究

양자열 成均館大學校 産業科學大學院 1994 국내석사