• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2005.04a
• /
• pp.199-201
• /
• 2005

This paper describes a simple procedure for the quantitative analysis of 7 PCBs (polychlorinated biphenyls) in soils on the waste reclaimed land, The procedure involved sample clean up using silicagel column, acetonitrile partition and sulfuric acid procedures. The instrumental technique is applied GC/PDD(gas chromatography/pulsed discharge detector) and GC/ECD(gas chromatography/electron capture detector). Concentration of $sub-{\mu}g/g$ level was attainable with 20g soils on the waste reclaimed land.

• Journal of Pharmaceutical Investigation
• /
• v.39 no.4
• /
• pp.263-267
• /
• 2009

The purpose of this study is to evaluate the efficacy of stipulated cleaning process, and the prohibition of cross-contamination and microbiological contamination, which inadequate cleaning in multi-production could occur, through cleaning validation of multi-purpose facility used to produce five biopharmaceutical products as sterile injection. After production of five biopharmaceutical products such as hGH, rhGCSF, rhEPO, rhFSH and rhIFN using vial filling machine, the cleaning validation such as residual analysis of active ingredients or human serum albumin, measurement of total organic carbon (TOC), residual analysis of detergent and microbiological contamination were carried out. In the case of rhGH and rhGCSF clean validations, drug residues were not detected. Furthermore, in the case of rhEPO, rhFSH and rhIFN clean validations, human serum albumin residues were not detected. At TOC (total organic carbon) analysis, all clean validations gave the TOC of about average 137.93%, not more than 150% of acceptance criteria. At sodium analysis for the checking of residues of cleaning agent, sodium residues were not detected. In sterility test, they showed no microbiological contamination of bacteria and fungi. Thus, this cleaning validation was determined as successful in protection of cross-contamination and induction of safety in multi-purpose facility.

• Analytical Science and Technology
• /
• v.13 no.4
• /
• pp.412-422
• /
• 2000

The polymeric FAB materials of air shower used in clean room of wafer industry have been outgassed with the dynamic headspace (ca.$100^{\circ}C$) for half an hour, and analyzed using GC-MS. The air in the clean room running air shower was sampled using sorbent tube method, and the organic compounds adsorbed in the sorbent tube were extracted using Soxhlet extraction method, and analyzed using GC-MS. The analytical results from FAB materials of air shower (electric over current relay, acryl plate. polycarbonate window, filter, fan housing, steel galvanized cold plate and canvas buffer) indicated that most of chemicals were originated from polymer fragments of FAB materials. Their analytical results have been compared with those from the air of clean room running air shower. These comparative results could lead to identify whether the sources of trace organic contaminants in clean room air are originated from the polymeric FAB material of air shower.

• Korean Chemical Engineering Research
• /
• v.50 no.3
• /
• pp.449-454
• /
• 2012

Economic feasibility of the process for a coal extraction under mild condition, which will produce ash-free coal at a temperature lower than that of coal softening, was analyzed. To this end, the plant of 6000 t/d in capacity was assumed to be constructed near a coal mine in Indonesia, and the IRR, NPV, B/C ratio, and DPP of the plant were calculated based on $96 million investment cost and 15 years service life. The IRR, NPV, B/C ratio, and DPP of the plant were calculated to be 31%, $87 million, 1.08, and 3.9 years, respectively, and which satisfied the evaluation criteria of investment. The economic feasibility of the plant was mainly dependent on the price of the coal initially fed and the residue coal remaining after the extraction, according to sensitivity analysis.

• Transactions of the Korean hydrogen and new energy society
• /
• v.31 no.3
• /
• pp.314-321
• /
• 2020

In this work, a preliminary design of an inlet guide vane and runner for developing a 2.5 kW hydraulic turbine was conducted by using computational fluid dynamic analysis. Three-dimensional Reynolds-averaged Navier-Stokes equations with shear stress transport turbulence model were used to analyze the fluid flow in the hydraulic turbine. The hexahedral grid system was used to construct computational domain, and the grid dependency test was performed to obtain the optimal grid system. Velocity triangle diagram considering the flow angles of the inlet guide vane and runner was analyzed to obtain a basic geometry of the inlet guide vane and runner. Through modification of the preliminary design, the hydraulic performances of the turbine have improved under overall drop conditions. Especially, the efficiency and power of the turbine increased by 0.95% and 1.45%, respectively, compared to those of the reference model.

• Journal of ILASS-Korea
• /
• v.20 no.1
• /
• pp.14-19
• /
• 2015

Recently, R&D demand for environmental friendly vehicle has rapidly increased due to its global environmental issues such as global warming, energy and economic crisis. Under this situation, the most realistic alternative way for environmental friendly vehicle is a clean diesel vehicle. The common-rail fuel injection system, as key technology of clean diesel vehicle, consists of a high pressure pump, common-rail, high pressure fuel line and electronic control injector. In common-rail high-pressure fuel injection system, high pressure wave of injection system and geometry of injector elements have a major effects on high-pressure fuel spray. Therefore, in this study, the numerical model was developed for analysis about the common-rail fuel pressure pulsation by using AMESim code. We could secure stability of common-rail high-pressure fuel injection system through optimal design of fuel line.

• The Korean Journal of Ecology
• /
• v.11 no.1
• /
• pp.29-36
• /
• 1988

This present study has been carried out to examine the correlation between the distribution of the coliform bacterial plasmids and the viability test against heavy metals in the upper stream of Han river(Gapyung; clean water) and the its basin (Anyang Cheon; polluted water). And the distribution of plasmids were examined to be used as trophic indicator for analysis between the clean and polluted waters. 1. A total of 110 isolates were analyzed for the presence of plasmids by means of the boiling method and agarose gel techniques. Plasmids were significantly more frequent in the strains which had been isolated from the clean water (14.3%). Also, there were much higher multiplicity of plasmids at the polluted water(41.0%), compared with the clean water (33.0%). By the comparision between molecular weight of bacterial plasmids in the clean water and those of polluted water, there were no significant differences of the clean water from the polluted water, to such extent as 30.0%, 28.6%, respectively, in frequency for occurrence of high molecular weight plasmids iver 35.8% Mdal. 2. Each isolate was carried out the resistance test for mercury(10-5M), nickel(10-3M) and arsenic (0.1%). At the polluted site, the survival ability of the plasmid-carrying straings(Hg, 31.0%l Ni, 5.7%; As, 65.7%) was higher than that of the non plasmid-carrying strains(Hg, 12.1%; Ni, 3.0%; As, 54.6%). This trend was more remarkable in the clean site (plasmid-carrying strains: 16.7%,-,-). As a result it is suggested that plasmids could be used as an indicator of a certain types of water pollution. In addition, heavy metals might have inflyenced, some extent, to the distribution of plasmids in the environment which has been surveyed in the present study.

• Korean Chemical Engineering Research
• /
• v.49 no.5
• /
• pp.639-643
• /
• 2011

Fry-drying of coal slurry is one of the upgrading low rank coal processes. It consists of slurry mixing, slurry dewatering, solvent recovery and briquetting. Cost estimation and economic feasibility are examined for the upgrading low rank coal process based on capacity of 1 million ton/yr. In case that investment costs are $100,000,000, discount rate is 12%, and service life is 20 years, the results of economic analysis are enough to satisfy the evaluation criteria of investment such as IRR, B/C ratio, NPV and discounted payback period. According to sensitivity analysis, investment value are very sensitive to raw material cost and product price. Since the bituminous coal price is currently soaring, it is expected that the investment value will increase more and more.

• Journal of the Korean Dietetic Association
• /
• v.23 no.2
• /
• pp.180-191
• /
• 2017

The purpose of this study was to identity the probability of cross-contamination from the environment. For this, we examined foodservices at 20 universities/colleges for microbiological analysis of their working facilities and environment as well as their preventive equipment against cross-contamination. Seventy percent of the 20 foodservices were found to maintain one unified working area, which suggests high probability of contamination of food/utensils/equipment in the cooking area by pre-preparation or dish washing. According to the microbiological analysis, the hygiene acceptance ratio of working facilities in the clean zone was 70%, which was higher than the average 45% hygiene acceptance ratio of working facilities in the contamination operating zone. There was a significant difference in the total plate count (P<0.001) and coliform count (P<0.01), which demonstrates that work tables in the clean zone were in a good state compared to those in the contamination operating zone. In the contamination operating zone, refrigerator shelves had a high probability of cross-contamination. Regarding the floor surface and airborne microbes, cooking areas which should be maintained as clean zones had higher cross-contamination probability than those in the contamination operating zone. So corrective actions such as cleaning and sanitizing, keeping dry floors, lowered temperature and humidity, shoe disinfecting facilities, and checking concentrations, are necessary to manage floor surfaces and airborne microbes in the cooking area.

• Journal of Environmental Health Sciences
• /
• v.42 no.6
• /
• pp.385-395
• /
• 2016

Objectives: The aim of this study was to assess exposure to VOCs and PAHs and the health effects on volunteers who participated in an oil spill cleanup in Yeosu. Methods: Atmospheric VOCs were evaluated in the vicinity of the accident site and questionnaire surveys were conducted to identify personal characteristics and acute health symptoms of clean-up workers seven days after the accident. The levels of metabolites of VOCs (t,t-MA, HA, PGA, MA, MHA) and PAHs (2-NAP, 1-OHP, 2-HF, 1-HPH), oxidative stress markers (TABARS, 8-OHdG) in the urine of workers were analyzed. Their correlation was determined by multiple regression analysis with SAS ver. 9.4. Results: Although the concentration of atmospheric VOCs in the residential areas were low at the time of survey, the levels of VOCs and PAHs metabolites in clean-up workers were higher than those in the control group after clean-up activities. The levels of urinary VOC and PAH metabolites were significantly increased after clean-up compared to those measured before participation. The thiobarbituric acid reactive substance (TBARS) concentrations were also increased and showed significant correlations with those of metabolites of benzene. Conclusion: This study shows that oil spill clean-up activities affect exposure to VOCs and PAHs and the health of clean-up workers. The results suggest the need for check-ups of participants in oil spill cleaning work.