• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.4
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• pp.221-226
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• 2008

Air pollution associated with the SOx emission from the shipboard propulsion and generation engines is becoming one of the major environmental concerns these days. Lead by the international organizations including IMO and European Union, a significantly strengthened air pollution related regulations have been introduced and they are becoming in practice as scheduled. Such rules are basically giving the guidelines for permissible SOx emission which can be only met by using high quality fuel oils with less sulfur content or operating scrubbing systems aiming at reducing SOx at the engine exhaust. Since both countermeasures can lead to the cost increase in ship building and operation, Korean shipbuilding industries, leading the world's market, need to be well aware of the ever changing regulations and be prepared with proper solutions. Here, we briefly summarize such latest rules and regulations on the air pollution at sea, and review some technical issues on the scrubbing systems available with some suggestions.

• Journal of Food Hygiene and Safety
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• v.30 no.1
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• pp.98-102
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• 2015

Oleanolic acid and its derivatives are pentacyclic triterpene acids, which are produced in many plants and herbs. These are considered safe and thus, oleanolic acid is now used for cosmetic and pharmaceutical industry. Oleanolic acid affects peptidoglycan in cell wall of bacteria. Hence, the antimicrobial activity of oleanolic acid is not very obvious to Gram-negative bacteria such as Escherichia coli, Yersinia enterocolitica, Shigella flexneri, and Shigella sonnei because the peptidoglycan is covered with outer membrane. However, oleanolic acid derivatives showed improved antimicrobial activity to Gram-negative bacteria. For Gram-positive bacteria such as Staphylococcus aureus and Listeria monocytogenes, oleanolic acid was very effective on reducing the cell counts of the pathogens. In addition, the cytotoxicity of oleanolic acid for human cell lines was minimal. Therefore, oleanolic acid should be considered as an antimicrobial food additive and a therapeutic agent to control foodborne pathogens.

• Environmental Analysis Health and Toxicology
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• v.19 no.4
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• pp.345-352
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• 2004

N-decane은 지방족탄화수소로 다른 탄환수소들과 같이 혼합된 형태로 존재하며 페인트 제거제나 드라이 크리닝 제품에 사용된다. 최근의 본 연구팀이 실시한 전자산업계의 MSDS 신뢰성조사 결과에 따르면 세정제의 사용 경향은 과거의 방향족 탄화수소나 CFC. HCFC에서 $C_{10}$이상의 지방족탄화수소 물질로 변화되고 있는 경향을 보여주었다. Stoddard solvent나 나프타 같은 탄화수소 혼합물에 대한 작업 환경노출기준은 설정되어있지만 n-decane에 대해서는 제한적인 독성자료 밖에 없으며 작업환경노출기준은 설정되어 있지 않다. 따라서 작업환경에 대한 적절한 관리기준제시와 독성학적 자료를 제공하기 위해 n-decane을 28일 반복 흡입독성시험을 실시하였다. 6주령 흰쥐로 체중이 229$\pm$10g되는 숫컷과 165$\pm$7g되는 암컷 흰쥐를 4개 용량군 즉 대조군, 저농도군(50ppm), 중농도군(200ppm), 고농도군(800ppm) (각군당 10마리)으로 설정하여 하루 6시간, 주5일로 4주간 흡입쳄버에서 노출시켰다. 28일간 노출 후 n-decane의 노출용량에 따른 암수의 체중에는 유의한 변화가 없었으며 유의한 혈액학적 생화학적 변화도 발견되지 않았다. 고농도로 노출된 수컷 몇 마리에서 고환 세정관에서의 공포화(vacuolization)가 발견되었으나, 간신장, 비장, 폐, 부신, 심장, 뇌 등 다른 장기에 대한 조직병리학적 검사에서는 뚜렷한 조직병리학적인 변화를 발견할 수 없었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.701-707
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• 2016

This study surveyed 150 men aged 30 to 50, a demographic which seborrheic dermatitis is common. The time of day one shampoos and recurrent fatigue were found to have a statistically significant impact on symptoms contributing to the main causes of seborrhea, including itchiness, excessive oil, acne, and redness on the scalp (p<0.01). Study results confirm lifestyle and shampoo habits, such as the frequent sense of fatigue, a routine work schedule, susceptibility to stress, the time of day one uses shampoo, and whether hair styling products are used, affects seborrheic scalp disease. This study found seborrheic scalp disease for office workers primarily resulted from shampoo habits, rashes were predominantly caused by a failure to rinse shampoo and dry hair completely, while secondary aggravating factors included irregular work schedules, recurrent tiredness, and chronic stress.

• Resources Recycling
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• v.20 no.6
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• pp.28-36
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• 2011

The adsorption of nickel(Ni) from sulfuric acid solution was carried out by ion exchange method. A series of batch tests in synthetic solutions were carried out using Lewatit Monoplus TP 220 resin. The following experimental parameters, such as temperature, shaking rate, reaction time, pH, resin dosage and concentration of nickel ions etc. were investigated to establish the effective optimum conditions of nickel adsorption. The solution pH(2.0~5.0) and shaking rate had little effects on the adsorption of nickel and adsorption time of 72hours was required to reach equilibrium. The experimental results show a good agreement with Feundlich isotherm and pseudo-second order reaction. The adsorption behavior of Ni obtained from synthetic solution was compared with that of waste electroplating solution. Elution of nickel from loaded resin increased with increase in $H_2SO_4$ concentration.

• Membrane Journal
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• v.26 no.1
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• pp.55-61
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• 2016

Organic fouling observed in submerged membrane filtration as a pretreatment for seawater desalination increases energy consumption for membrane operation because of requiring frequent chemical cleaning and membrane replacement. In membrane pretreatment for seawater facing with algae blooms, membrane fouling was observed in submerged microfiltration using sodium alginate model compound which is one of the main components of extracellular polymeric substances. Without aeration, aglinate fouling increased with its concentration while aeration reduced the alginate fouling effectively regardless of its concentration tested. In the absence of aeration, alingate fouling tended to be decreased with increasing calcium concentration. However, this effectiveness was reduced by increasing sodium chloride concentration. At high concentration of sodium chloride and calcium similar to the seawater conditions, aeration reduced initial fouling. However, as time progressed, the effect of increased airflow rate on fouling reduction was not significant, implying that optimum airflow rate to control alginate fouling in submerged microfiltration can exist.

• Journal of Oral Medicine and Pain
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• v.31 no.2
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• pp.177-183
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• 2006

The management of refractory pain and limitation of mouth opening in the temporomandibular joint (TMJ) is both challenging and controversial. Arthrocentesis is a simple technique and it can be used instead of more invasive surgical procedures for patients who failed to conventional conservative treatments. The patients in this case report had complained persistent severe pain and restricted mandibular movement of TMJ, although they had been treated with conservative therapy, e.g., stabilization splint therapy, behavioral therapy, physical therapy, pharmacological therapy. Therefore we employed arthrocentesis for these patients, and they showed significant reduction of pain and improvement of mandibular movement after repetitive arthrocentesis. We recommend arthrocentesis as an effective, minimally invasive technique for patients with continuing severe pain and restricted mobility in the TMJ that is unresponsive to conservative management.

• Journal of Environmental Policy
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• v.8 no.2
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• pp.145-164
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• 2009

Environmental problems, such as the depletion of natural resources, global warming, and the destruction of ecological systems, are among the most serious problems facing the planet. Since the early 1990's, many OECD countries have undertaken green tax reforms by introducing new environmental taxes to protect the environment. Environmental taxes have been used as an instrument of environmental policy more than direct regulation because economic instruments have a comparative advantage over direct regulation in terms of cost effectiveness and pollution abatement incentives. However, one important reason why green tax reforms have not progressed is due to fears regarding the negative effect of environmental taxes on international competitiveness in the industry and trade sectors. The main purpose of this paper is to analyze the effects of environmental taxes on industry and trade by using a theoretical model to compare the effects of environmental taxes on pollution-intensive and energy-saving industries.

• Clinical and Experimental Pediatrics
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• v.51 no.9
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• pp.1023-1027
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• 2008

A group of patients with Kawasaki disease (KD) initially present with cervical lymphadenitis or deep neck infection. These unusual KD presentations lead to unnecessary antibiotic therapy or surgical intervention, thereby delaying intravenous immunoglobulin treatment and increasing the risk of coronary artery damage. We present four KD patients whose initial presentations mimicked a retropharyngeal abscess. Nonsuppurative cervical lymphadenitis or suspected neck abscess unresponsive to intravenous antibiotics could signal the possibility of KD.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.4
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• pp.429-436
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• 2008

Membrane system has been increasingly considered as a safe and cost-effective water treatment process especially in case of small scale water works. This research is a basis of membrane application in water works through a long period test with obtaining operation skills and evaluation of water quality and cost competitiveness. For the research, the UF membrane system was installed in small water treatment plant that uses river-bed water as raw water. The system was consisted of 2 stage membrane and operated in constant flow mode (Flux: 1.5, 1.0, 0.9, 0.6). In each different flux condition, TMP trends were showed better results at lower flux condition. And through the high flux condition test, it is certified that membrane system could deal with breakdown of one stage. Water quality of permeate was satisfied the water quality standards especially turbidity. To know what mainly causes fouling on membrane, the test by membrane with several cleaning agents and EDX analysis have done in lab. Through the tests, ferrous concentration in raw water, backwashing water and membrane surface etc. was high and it causes fouling inside and outside of membrane. So acid cleaning using organic acid such as oxalic acid is necessary in Chemical in Place (CIP). At the economical aspect the electrical cost of membrane system is higher than that of slow sand filtration but labor cost can be reduced by automation. However, the use of labor should be determined considering effectiveness and stability of operation. Because during the operation, there are several breakdown such as electrical shock by lightning, water drop in summer, etc.