• Journal of Environmental Impact Assessment
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• v.22 no.3
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• pp.203-217
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• 2013

This study looked at how to establish effluent limitation standards for formaldehyde, a toxic chemical widely used in industries. To this end, we reviewed Water Quality Based Effluent Limitation (WQBEL), Technology Based Effluent Limitation (TBEL), and water quality criteria for protection of human health and aquatic organism. Based on the results, we estimated formaldehyde effluent limitation standards appropriate to control water quality of industrial wastewater in Korea. However, this study has limits due to the lack of some data necessary in estimating formaldehyde effluent limitation. For example, although water quality criteria based on non-carcinogenic properties of formaldehyde were calculated, those based on carcinogenic properties were not be able to estimate because of the absence of applicable cancer potency factor q1. Without applicable factor, we calculated water quality standards for formaldehyde based on water quality criteria of advanced countries including the United States, while with no water quality standard we referred to applicable drinking water quality standards of other countries. For eco-toxicity based on water quality criteria, proper figures could not be calculated since there have been few reliable data.

• Journal of the Korean Society for Heat Treatment
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• v.33 no.1
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• pp.20-24
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• 2020

Single crystal diamonds are in great demand in such fields as mechanical, electronic applications and optoelectronics. Large area single crystal diamonds are attracting attention in future industries for mass production and low cost. In this study, hot filament CVD (HFCVD) is used to grow large area single crystal diamond. However, the growth rate of large area single crystal diamond using HFCVD is known to be very low. The goal of this study is to use single crystal diamond substrates in HFCVD with methane-hydrogen gas mixtures to increase the growth rate of single crystal diamond and to optimize the conditions by analysing the effects of deposition conditions for high quality crystallinity. The deposition pressure, the ratio of CH₄/H₂ gas, the substrate temperature and the distance between the filament and the substrate were optimized. The sample used a 4×4 (mm²) size single crystal diamond substrate (100), the CH₄/H₂ gas ratio was fixed at 5%, the substrate temperature was synthesized to about 1000℃. At this time, the deposition pressure was changed to three types of 50, 75, 85 Torr and deposited. Finally, optimization was investigated under pressure conditions to analyse the growth rate and quality of single crystal diamond.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2000.11a
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• pp.1-14
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• 2000

The Near Infrared region of the energy spectrum was first discovered by Hershel in the year 1800. The principles of NIR is based on light absorption of specific organic chemical bonds. The absorption at each wavelength is measured and a spectre is obtained. The spectre is then treated mathematically and with the absorption data is converted to absolute units via a calibration. In the last two decades it has developed dramatically. With the invention of computers and the ability to treat a large amount of data in a very short time the use of NIR for many different purposes has developed very fast. During the last decade with the aid of very powerful PC's the application of NIR technology has become even more widespread. Now or days development of very robust calibrations can be done in a relatively short time with a minimum of resources. The use of Near Infrared Spectroscopy (NIR) in the Meat industry is relatively new. The first installations were taken into operation in the 80ties. The Meat Industry in often referred to as rather conservative and slow to embrace new technologies, they stay with the old and proven methods. The first NIR instruments used by the Meat Industry, and most other industries, were multipurpose build, which means that the sample presentation was not well suited to this particular application, or many other applications for that sake. As the Meat Industry grows and develops to meet the demands of the modern markets, they realise the need for better control of processes and final products. From the early 90 ties and onward the demand for 'rear time' rapid results starts growing, and some suppliers of NIR instruments (and instruments based on other technologies, like X-ray) start to develop and manufacture instrumentation dedicated to the particular needs of the Meat Industry. Today it is estimated that there are approximately 2000 rapid instruments placed in the Meat industry world-wide. By far most of these are used as at-line or laboratory installations, but the trend and need is moving towards real on-line or in-line solutions. NIR is the most cost effective and reproducible analytical procedure available for the twenty first century.

• Proceedings of the Korean Environmental Health Society Conference
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• 2004.06a
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• pp.146-150
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• 2004

Degradation efficiency of pentachlorophenol (PCP) by using direct UV photolysis and $TiO_2$ photocatalysis was evaluated with both chemical analyses and acute toxicity assessment employing luminescent bacteria Vibrio fischeri. PCP was chosen as a target compound in this study because of its wide application as fungicide, bactericide, insecticide and wood preservative in agriculture and many industries, in addition to its well-known environmental consequences. The acute toxicity to the microbe was reduced by >60% when applying UV alone, and was completely removed when treated with $UV-TiO_2$ combinations. Toxicity reduction pattern determined with the Microtox Assay generally corresponds with the chemistry data: However, it should be noted that toxicity was greater than expected by the chemistry data. Formation of TCBQ, a toxic byprodut, could not explain observed microbial toxicity. These observations are probably due to the presence of unidentified toxic PCP byproducts, which may include polychlorinated dibenzodioxins and polychlorinated dibenzofurans. When Microtox results were compared between different exposure time, i.e.,5 min and 15 min, an interesting pattern was noted with $UVA-\;TiO_2$ treatment. While no microbial toxicity was observed with 5 min exposure, an EC50 value of 45.4% was estimated with 15 min exposure, which was not observed in $UVB-\;TiO_2$ exposure. This result may suggest the presence of unidentified toxic degradation products generated in the later stage of treatment. Based on this study, $TiO_2$ photocatalyst, together with UVB photolysis could improve the removal of both PCP and its toxic derivatives in more efficient way. The Microtox Assay is promising and economical method for monitoring efficiency of wastewater treatment processes.

• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.81-90
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• 2014

Modern systems can be characterized by ever-increasing complexity of both the functionality and system scale. Thus, due to the complexity the chances of accidents resulting from systems failure can then be growing. Even worse is that those accidents could result in disastrous damage to the human being and properties as well. Therefore, the need for the developed systems to be assured with systems safety is apparent in a variety of industries such as rail, automobiles, airplanes, ships, oil refinery, chemical production plants, and so on. To this end, in the industry an appropriate safety standard has been published for its own safety-assured products. One of the core activities included in the most safety standards is hazard analysis. A conventional approach to hazard analysis seems to depend upon the scenarios derived from the ones used previously in similar systems or based on former experience. The objective of this paper is to study an improved process for scenario-based hazard analysis. To achieve the goal, the top-level safety requirements have first been reflected in the scenarios. By analyzing and using them, the result has then lead to the development of safety-assured systems. The method of modeling and simulation has been adopted in the generation and verification of scenarios to check whether the safety requirements are reflected properly in the scenarios. Application of the study result in the case of rail safety assurance has also been discussed.

• Journal of The Korean Society of Clinical Toxicology
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• v.13 no.1
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• pp.36-39
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• 2015

Copper sulfate is a copper compound used widely in the chemical and agriculture industries. Most intoxication occurs in developing countries of Southeast Asia particularly India, but rarely occurs in Western countries. The early symptoms of intoxication are nausea, vomiting, diarrhea, and abdominal cramps, and the most distinguishable clue is bluish vomiting. The clinical signs of copper sulfate intoxication can vary according to the amount ingested. A 75-year old man came to our emergency room because he had taken approximately 250 ml copper sulfate per oral. His Glasgow Coma Scale (GCS) score was 14 and vital signs were blood pressure 173/111 mmHg, pulse rate 24 bpm, respiration rate 24 bpm, and body temperature $36.1^{\circ}$ .... Arterial blood gas analysis (ABGa) showed mild hypoxemia and just improved after 2 L/min oxygen supply via nasal cannula. Other laboratory tests and chest CT scan showed no clinical significance. Three hours later, the patient's mental status showed sudden deterioration (GCS 11), and ABGa showed hypercarbia. He was arrested and his spontaneous circulation returned after 8 minutes CPR. However, 22 minutes later, he was arrested again and returned after 3 minutes CPR. The family did not want additional resuscitation, so that he died 5 hours after ED visit. In my knowledge, early deaths are the consequence of shock, while late mortality is related to renal and hepatic failure. However, as this case shows, consideration of early definite airway preservation is reasonable in a case of supposed copper sulfate intoxication, because the patients can show rapid deterioration even when serious clinical manifestation are not presented initially.

• Corrosion Science and Technology
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• v.14 no.5
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• pp.213-217
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• 2015

Recently, household electronic industries require environmentally-friendly and highly functional steels in order to enhance the quality of human life. Customers especially require both excellent corrosion and abrasion resistant anti-fingerprint steels for digital TV panels. Thus POSCO has developed new functional electro-galvanized steels, which have double coated layers with organic-inorganic composites on the zinc surface of the steel for usage as the bottom chassis panel of TVs. The inorganic solution for the bottom layer consists of inorganic phosphate, magnesium, and zirconium compounds with a small amount of epoxy binder, and affords both improved adhesion properties by chemical conversion reactions and corrosion resistance due to a self-healing effect. The composite solution for the top layer was prepared by fine dispersion of organic-inorganic ingredients that consist of a urethane modified polyacrylate polymer, hardener, silica sol and a titanium complex inhibitor in aqueous media. Both composite solutions were coated on the steel surface by using a roll coater and then cured through an induction furnace in the electro-galvanizing line. New anti-fingerprint steel was evaluated for quality performance through such procedures as the salt spray test for corrosion resistance, tribological test for abrasion resistance, and conductivity test for surface electric conductance regarding to both types of polymer resin and coating weight of composite solution. New composite coated anti-fingerprint steels afford both better corrosion resistance and abrasion properties compared to conventional anti-fingerprint steel that mainly consists of acrylate polymers. Detailed discussions of both composite solutions and experimental results suggest that urethane modifications of acrylate polymers of composite solutions play a key role in enhanced quality performances.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.144-144
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• 2013

Non-thermal atmospheric pressure plasmas have recently garnered much attention due to their unique physical and chemical properties that are sometimes significantly different from those of low pressure plasmas. It can offer many possible application areas including nano and bio/medical areas. Many different types of plasma sources have been developed for specific needs, which can be one of the important merits of the atmospheric pressure plasmas since characteristics of the produced plasma depend significantly on operating parameters such as driving frequency, supply gas type, driving voltage waveform, gas flow rate, gas composition, geometrical factor etc. Among many source configurations, parallel plate type geometry is one of the simplest configurations so that it can offer many insights for understanding basic underlying physics. Traditionally, the parallel plate type set up has been studied actively for understanding low pressure plasma physics along with extensive employment in industries for the same reason. By considering that understanding basic physics, in conjunction with plasma-surface interactions especially for nano & bio materials, should be pursued in parallel with applications, we investigated atmospheric pressure discharge characteristics in a parallel plate type capacitive discharge source with two parallel copper electrodes of 60 mm in diameter and several millimeters in gap distance. In this presentation, some plasma characteristics by varying many operating variables such as inter-electrode distance, gas pressure, gas composition, driving frequency etc will be discussed. The results may be utilized for plasma control for widening application flexibility.

• Microbiology and Biotechnology Letters
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• v.39 no.3
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• pp.189-199
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• 2011

Recently seaweed polysaccharides have been extensively studied due to their various biological functions including antitumor, antiviral, anticoagulant, and anti-inflammatory activities. Although seaweed polysaccharides are known to possess numerous beneficial properties, their industrial applications have been limited due to the low inclusion efficiency and high cost of manufacturing involved in chemical hydrolysis. In addition, the smell of seaweed has been a limiting factor in its application in the food and cosmetic industries. Therefore, novel hydrolysis methods and the deodorization of seaweed are required if the extensive application of seaweed polysaccharides is to be seen. A number of studies have examined various seaweed polysaccharide-degrading enzymes, which have been isolated from marine microorganisms, and enzymatic hydrolysis processes have been investigated for the improvement of production yields and the bioefficacy of seaweed polysaccharides. This review is a synopsis on the properties of seaweed polysaccharides-degrading enzymes from marine microorganisms and their industrial applications. The review reveals the pressing need for more concentrated research on the development of new biological materials from seaweed.

• Journal of Microbiology and Biotechnology
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• v.21 no.9
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• pp.960-967
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• 2011

Tannin acyl hydrolase, also known as tannase, is an enzyme with important applications in the food, feed, pharmaceutical, and chemical industries. However, despite a growing interest in the catalytic properties of tannase, its practical use is very limited owing to high production costs. Several studies have already demonstrated the advantages of solid-state fermentation (SSF) for the production of fungal tannase, yet the optimal conditions for enzyme production strongly depend on the microbial strain utilized. Therefore, the aim of this study was to improve the tannase production by a locally isolated A. niger strain in an SSF system. The SSF was carried out in packed-bed bioreactors using polyurethane foam as an inert support impregnated with defined culture media. The process parameters influencing the enzyme production were identified using a Plackett-Burman design, where the substrate concentration, initial pH, and incubation temperature were determined as the most significant. These parameters were then further optimized using a Box-Behnken design. The maximum tannase production was obtained with a high tannic acid concentration (50 g/l), relatively low incubation temperature ($30^{\circ}C$), and unique low initial pH (4.0). The statistical strategy aided in increasing the enzyme activity nearly 1.97-fold, from 4,030 to 7,955 U/l. Consequently, these findings can lead to the development of a fermentation system that is able to produce large amounts of tannase in economical, compact, and scalable reactors.