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전영남,백원석,송형운,유경석,김성천 조선대학교 환경공해연구소 2004 環境公害硏究 Vol.18 No.-
The advanced waste oil incinerator is suggested that has heat recirculation region in the combustor to burn out the waste oil completely in high temperature zone and heat recuperator in the left side of combustion cavity which plays a role of the flame stabilization of main burner flame by heat recovery of exhaust gas to incinerate waste oil contained water. In order to investigate a simultaneously incineration efficiency of the vessel waste oil contained the hazardous waste which occurs from the vessel and the sea outflow waste oil experiments have been carried out using the emulsion fuel mixed the water and bunker fuel oil C and the blend mixed the light oil and the waste surrogate material (acetonitrile:CH_(3)CN). The results of experiments showed that the waste oil incinerator developed in this study was excellent for the incineration efficiency of waste oil at an air ratio of 1.46 and DRE (destruction and removal efficiencies) of CH_(3)CN was 99.9996% ("5 nines"). And optimum operating conditions for the secondary air flow rate of internal mix burner, preheating temperature and injection point of shipboard waste oil contained acetonitrile were suggested.
전영남,송형운,백원석 조선대학교 환경공해연구소 2006 環境公害硏究 Vol.19 No.1
The purpose of this study lies primarily on the development of the sludge dryer for the dehydrated sludge of moisture content with 70~80 wt.%. The sludge dryer was modified from the rotary kiln type dryer. A numerical simulation on the thermal flow performance in the sludge dryer was carried out to investigate the design factor and operating conditions, Parametric screening studies were carried out for variations of the following variables: dryer shape, injection length of combustion air, velocity of combustion air, temperature of combustion air. By predictive results, the sludge dryer has a good drying characteristics so that input sludge increased with retention time by recirculation zone of high temperature combustion gas in the bed of sludge dryer. Parametric screening studies have been conducted to study optimal dryer shape and operating condition.
Development of analytical method for metals and metalloids in electronic cigarette using ICP-MS
Hyoung-Joon Park,Seok Heo,Minkyoung Lee,Minsoo Kim,Changyong Yoon,Sunyoung Baek 한국분석과학회 2021 학술대회논문집 Vol.2021 No.11
Electronic cigarette has been considered as a safer alternative to conventional cigarette and the use of e-cigarette was quickly increasing despite uncertainties about their toxicity and health effects. The inhalation of metals and metalloids was associated with serious effects to smokers, including cancer, cardiovascular disease and neurotoxicity. Our purpose of this study was to develop the method to quantify 18 inorganic chemical elements in e-cigarettes using inductively coupled plasma and mass spectrometry (ICP-MS). Linearity of R² > 0.99 was secured about within the range of 1 to 20 ng/mL. The limits of quantification were below 6.8 and 98.7 ng/g. All elements showed a recovery of 80.9-119.8%, accuracy of 86.0-104.8%, and precision below 12.3%. The developed method was applied to 25 commercial products that were purchased from retailers in Korea. This analytical method could be suitable for the evaluation of contents of metals and metalloids in e-cigarette.
Effect of secondary phase particles on the tensile behavior of Mg-Zn-Ca alloy
Baek, Seung Mi,Park, Hyung Keun,Yoon, Jae Ik,Jung, Jaimyun,Moon, Ji Hyun,Lee, Seok Gyu,Kim, Jae H.,Kim, Taek Soo,Lee, Sunghak,Kim, Nack J.,Kim, Hyoung Seop Elsevier 2018 Materials science & engineering. properties, micro Vol.735 No.-
<P><B>Abstract</B></P> <P>In the present study, the effect of secondary phase particles and deformation localization on tensile behaviors of Mg-Zn-Ca alloy were investigated using micro-digital image correlation method. To isolate the effect of the secondary phase particles on tensile behavior, the fractions of the secondary phase particles were adjusted by controlling the annealing temperature. Thermodynamic calculations were performed to identify the fractions of the secondary phase particles. The finite element method was conducted to confirm the localized deformation around the secondary phase particles considering 3-dimensional microstructure. The results suggest that the total fraction of the secondary phase particles affected the localized deformation around the particles and micro-crack propagation process during a tensile test.</P>
Discrimination of biological and artificial nicotine in e-liquid
Hyoung-Joon Park,Heesung Moon,Min Kyoung Lee,Min Soo Kim,Seok Heo,Chang-Yong Yoon,Sunyoung Baek 한국분석과학회 2023 분석과학 Vol.36 No.1
As the use of e-liquid cigarettes is rapidly increasing worldwide, it multiplies the potential risk undisclosed to the health of non- and smokers. To reduce the hazard, each country has its own set of regulations for controlling e-liquids. In Korea, the narrow definition of tobacco makes it difficult and have been steadily occurring tax evasion exploiting the difference in natural and artificial nicotine. Therefore, it is very important to distinguish source of nicotine for their regulation. To find biochemical discriminant markers, this study established analysis methods based on high-performance liquid chromatography coupled with diode array detector (HPLC-DAD) and high-performance liquid chromatography coupled with triple Quadrupole mass spectrometry (HPLC-MS/MS) for nicotine enantiomers and tobacco alkaloids targeted using the difference in pathways of nicotine biosynthesis and chemical synthesis. The method was validated by experimenting linearity (R2 > 0.999), recovery (80.99-108.41 %), accuracy (94.11-109.73 %) and precision (0.04-8.27 %). Then, the results for discrimination of the nicotine obtained from analysis of 65 commercial e-liquid products available in Korean market was evaluated. The method successfully applied to the e-liquids and one sample labelled ‘synthetic nicotine’ for tax exemption was found to contain a natural nicotine product. This method can be used to determine whether an e-liquid product uses natural or artificial nicotine and monitor non-taxable eliquid products. The method is more scientific than the existing one, which relies only on field evidence.
Streptococcus intermedius liver abscess with septic endophthalmitis and septic pulmonary emboli
( Gwang Seok Yoon ),( Jae Hyoung Im ),( Ji Hyeon Baek ),( Jin Soo Lee ) 대한내과학회 2013 대한내과학회 추계학술발표논문집 Vol.2013 No.1
간 농양에서 균혈증에 의해 발생한 전이감염은 종종 증례 보고가 있었고 주된 세균은 Klebsiella pneumoniae로 알려져 있다. 본 저자들은 Streptococcus intermedius에 의한 간 농양에서 패혈성 안구내염과 패혈성 폐색전증이 동반된 증례를 보고하는 바이다. 40세 남자가 4일 전부터 시작된 근육통과 우측 눈의 이물감으로 내원하였다. 과거력과 가족력은 특이 소견 없었다. 신체 진찰에서 38.7℃의 발열이 있었고 우측 결막은 충혈되어 있었다. 흉부 청진에서 우하폐야에서 수포음이 들렸고 복부 진찰에서 압통과 반동압통은 없었다. 혈액 검사에서 백혈구 23,630/μL, 혈색소 15.3 g/dL 그리고 혈소판은 471,000/μL이었다. C-reactive protein (CRP) 35.3 mg/dL, 적혈구침강속도(ESR) 94 mm/hr로 상승 되어 있었다. 단순 흉부 방사선 x-ray 에서 우중폐야에서 혼탁이 보였다. 안저 검사 및 세극등 검사에서는 안구내염 소견이 보였다. 원발성 폐렴과 동반된 패혈성 안구내염 가능성이 가장 높을 것으로 판단하여 경험적 항생제(cefotaxime, azithromycin)를 투여하였다. 하지만 단순 흉부 방사선 x-ray에서 폐렴양 병변이 증가하였고 임상 양상은 호전되지 않았다. 혈액배양검사 결과 Viridans group Streptococci가 자랐고, 최종 동정 결과 Streptococcus intermedius가 확인되었다. 원발 병소를 파악하기 위해 흉부 컴퓨터 단층촬영을 시행하였고 패혈성 폐색전증으로 보이는 우폐하엽의 흉막하 경화와 간 우엽의 농양이 보였다. 균혈증의 다른 원발 병소 확인을 위해 경흉부 심초음파 검사와 대장내시경 검사를 하였고 특이 소견은 발견되지 않았다. 초음파 유도하 경피적 농양 세침 흡인 배양 검사에서 Streptococcus intermedius가 자라 원발성 간 농양의 균혈증에 의한 패혈성 안구내염과 패혈성 폐색전증으로 진단하였다. 환자는 세균 배양 감수성 결과에 따라 cefotaxime을 사용하였고 간 농양에서의 혐기성 미생물 동반 감염 가능성을 염두에 두고 metronidazole을 함께 사용하였다. 간 농양에 대해 초음파 유도하 경피적 농양 배액술을 시행하였다. 안구내염에 대해서는 유리체내 약물 주사법을 2차례 시행하였으나 호전 보이지 않아 유리체절제술을 2차례 시행 하였다. 환자는 시력의 큰 호전은 없었으나 발열과 혈액 검사 결과가 크게 호전되어 입원 29일째 경구 항생제를 유지한 채 퇴원하였고, 퇴원 35일 째 항생제 치료를 중단한 후 외래에서 추적관찰 중이다. Streptococcus intermedius에 의한 균혈증은 흔하지 않지만 수반되는 감염이 있을 경우에는 기저 농양을 항상 염두에 두여야 할 것으로 생각된다.