• 한국가스학회지
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• 제16권5호
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• pp.41-46
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• 2012

인화점은 공기 속 가연성 증기의 농도가 연소하한계(lower flammability limit)에 도달할 때의 최저 온도이며, 산업현장에서 사용하는 물질들의 화재와 폭발의 위험성을 결정하는 중요한 물성치이다. 단일 성분의 인화점 정보는 여러 문헌에서 얻을 수 있으나, 이성분계 혼합물의 인화점은 충분히 제공되어 있지 않다. 본 연구에서는 tert-pentanol+n-decanel 계의 인화점을 Tag 개방식 장치를 이용하여 측정하였다. 실험값은 Raoult의 법칙과, Wilson 식과 NRTL 식을 활용한 최적화 기법에 의해 계산된 값들과 비교되었다. 최적화 기법에 의한 계산값이 Rauolt의 법칙에 의한 계산값 보다 실험값에 더욱 근접하였다.

• 대한임상독성학회지
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• 제4권2호
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• pp.175-179
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• 2006

Welders are exposed to a number of hazards including metal fumes, toxic gases, electricity, heat, noise, and radiation such as ultraviolet and infrared light. We encountered a patient who developed non-cardiogenic pulmonary edema within a day after cutting copper pipe with an oxyethylene torch. The patient was a 26-year-old welder. He complained of dyspnea, generalized myalgia, and febrile sensation the following morning. The patient's chest X-ray and chest CT scan showed extensively distributed and ill-defined centrilobular nodules. Both his symptoms and chest X-ray abnormalities improved spontaneously. We attributed the patient's symptoms to non-cardiogenic pulmonary edema due to nitrogen dioxide, reasoning that: 1) the pipe consisted only of copper, according to material safety data sheet (MSDS); 2) a previous report in the literature demonstrated increased nitrogen dioxide levels under similar conditions; 3) the patient's clinical course and radiologic findings were very reminiscent of non-cardiogenic pulmonary edema following accidental exposure to nitrogen dioxide.

• 전자공학회논문지
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• 제50권1호
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• pp.239-245
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• 2013

발전소 내 고압 단자대 및 전력구 케이블 인입부에서 주변 전력기기들의 지속적인 진동 및 순간적인 충격의 발생으로 케이블 단자 또는 접속부 접촉점에 열화가 발생하는 사고가 일어난다. 접촉점에서의 열화 발생은 큰 사고로 이어질 수 있으며 안정적으로 전력을 공급해야 하는 발전소에서는 열화 발생을 예측하기 위한 다양한 연구가 시도되고 있다. 이에 비접촉식 적외선 센서를 이용하여 온도를 측정하는 방식이 있으며 이러한 방식의 궁극적인 목적은 측정하고자 하는 대상체를 최적의 거리에서 감시함으로 접촉점의 열화 발생뿐 아니라 센서 측정범위 내의 열화의 상태도 감시하는 데 있다. 연결부 온도를 측정하고 열화 상태를 실시간 감시하여 사용자에게 가시, 가청 알람을 주어 사용자가 열화사고를 인지하여 미연에 방지할 수 있게 한다. 그러나 이러한 시스템을 구축하기 위해서는 감시 장치를 설치, 운영해야 하는 어려움이 있다. 본 연구에서는 설치 용이성을 고려하여 소출력 배터리 동작모듈로 접속부의 온도를 측정하고 이를 감시할 수 있는 적외선센서를 이용한 무선감시시스템을 개발하였다.

• 한국환경보건학회지
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• 제40권2호
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• pp.105-113
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• 2014

Objectives: It is necessary to apply quantitative structure activity relationship (QSAR) for the various chemicals with insufficient toxicity data that are used in the workplace, based on the precautionary principle. This study aims to find application plan of QSAR software tool for predicting health hazards such as genetic toxicity, and carcinogenicity for some chemicals used in the electronics industries. Methods: Toxicity prediction of 21 chemicals such as 5-aminotetrazole, ethyl lactate, digallium trioxide, etc. used in electronics industries was assessed by Toxicity Prediction by Komputer Assisted Technology (TOPKAT). In order to identify the suitability and reliability of carcinogenicity prediction, 25 chemicals such as 4-aminobiphenyl, ethylene oxide, etc. which are classified as Group 1 carcinogens by the International Agency for Research on Cancer (IARC) were selected. Results: Among 21 chemicals, we obtained prediction results for 5 carcinogens, 8 non-carcinogens and 8 unpredictability chemicals. On the other hand, the carcinogenic potential of 5 carcinogens was found to be low by relevant research testing data and Oncologic TM tool. Seven of the 25 carcinogens (IARC Group 1) were wrongly predicted as non-carcinogens (false negative rate: 36.8%). We confirmed that the prediction error could be improved by combining genetic toxicity information such as mutagenicity. Conclusions: Some compounds, including inorganic chemicals and polymers, were still limited for applying toxicity prediction program. Carcinogenicity prediction may be further improved by conducting cross-validation of various toxicity prediction programs, or application of the theoretical molecular descriptors.

• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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• pp.6267-6271
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• 2013

Objective: To determine clinical efficacy, safety and prognostic factors of pemetrexed plus platinum as first-line treatment in patients with advanced non-small cell lung cancer (NSCLC). Materials and Methods: Clinical characteristics, short-term efficacy, survival and adverse reactions of 47 advanced non-squamous NSCLC patients who had received pemetrexed plus platinum as first-line treatment in Shanghai Pulmonary Hospital from January 2009 to June 2011 were retrospectively analyzed. The Chi-squared test was applied to statistically analyze the overall response rate (ORR), disease control rate (DCR) and toxicity reactions in both groups, while survival data wereanalyzed by Kaplan-Meier and logrank methods, and the COX proportional hazards model was adopted for a series of multi-factor analyses. Results: Only two patients were lost to follow-up. The ORR, DCR, medium progression-free survival time (PFS) and medium overall survival (OS) were 31.9%, 74.5%, 5 months and 15.2 months, while 1- and 2-year survival rates were 63.8% (30/47) and 19.2% (9/47), respectively. Single-factor analysis showed that tumor pathological patterns and efficacy were in association with medium PFS (P<0.05), whereas tumor pathological patterns, smoking history and efficacy were closely connected with medium OS (P<0.05). Multi-factor analyses demonstrated that pathological patterns and efficacy were independent factors influencing OS (P<0.05). The rate of toxicity reactions in degree III/IV was low, including hematologic toxicity marked by decline in white blood cell count and decrease in the platelet count (PLT), and non-hematologic toxicity manifested by gastrointestinal reactions, such as nausea and vomiting. Conclusions: Pemetrexed plus platinum as first-line treatment has excellent efficacy and slight adverse reactions with favorable drug-tolerance in patients with advanced non-squamous NSCLC.

• 한국식품조리과학회지
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• 제31권2호
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• pp.153-161
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• 2015

This study was conducted to investigate the consumption practices of ready-to-eat (RTE) foods and to analyze the microbiological hazard of kimbab, a Korean dish, and the most popular of the RTE foods eaten by participants in this study. A questionnaire was distributed to 230 university students who had previously purchased RTE foods, and 224 were collected (response rate: 97.4%). Statistical analyses were conducted on the questionnaires using the SPSS program, and a total of 135 kimbab products were sampled for aerobic plate counts, coliforms, E. coli, E. coli O157:H7, Staphylococcus aureus, Salmonella spp., and Listeria monocytogenes. The results of the analyses are as follows. Kimbab (87.0%), sandwich (86.4%), hamburger (89.8%), lunchbox (81.5%), and sushi (87.4%) were most often eaten immediately after purchasing. Additionally, the results of the microbiological hazards analysis of kimbab showed that the aerobic plate counts were significantly different according to the purchasing price (p<0.01). The coliform levels were significantly different according to the place of purchase (p<0.01) and the major ingredients of kimbab (p<0.05). In addition, Staphylococcus aureus and E. coli were detected in 5.9% and 5.2% of the tested samples, respectively. However, E. coli O157:H7, Salmonella spp., and Listeria monocytogenes were not detected in any of the samples. In conclusion, the manufacturers of RTE foods should apply the HACCP system for food safety.

• 한국축산식품학회지
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• 제30권4호
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• pp.590-596
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• 2010

Meat and meat products are a potential source of food-borne pathogens, including Staphylococcus aureus, Salmonella spp., Escherichia coli O157:H7, and Bacillus cereus. A sensitive and specific PCR assay for the detection of these pathogens in meat and meat products was developed in this study, as part of a broader effort to reduce the potential health hazards posed by these pathogens. Initially, PCR conditions were standardized with purified DNA. Under standard conditions, the detection level for PCR was as low as 10 pg of purified bacterial DNA. After overnight growth of bacteria in a broth medium, as few as $10^2$ CFU of bacteria were detected by PCR assay. The primers employed in the PCR assay were found to be highly specific for individual organisms, and evidenced no cross-reactivity with heterologous organisms. Additionally, the multiplex PCR assays also amplified some target genes from the four pathogens, and multiplex amplification was obtained from as little as 10 pg of DNA, thus illustrating the excellent specificity and high sensitivity of the assay. In conclusion, this PCR-based technique provides a sensitive and specific method for the detection of S. aureus, Salmonella spp., E. coli O157:H7, and B. cereus in meat and meat products.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1085-1086
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• 2008

Shunt active filter can compensate harmonic current of utility results from non-linear loads such as rectifiers, cycloconverters and arc furnaces. It has the same structure as photovoltaic(PV) generation system. So, It was proposed the system that generates PV power and also has active filter function. It is called PV-AF(Photovoltaic and Active Filter) power generation system. Islanding can be occurred in an inverter based dispersed generation system, when the system disconnected from utility and loads are entirely supplied by PV system only. Islanding may result in interference to grid protection devices, equipment damage, and even personnel safety hazards. Therefore, islanding has to be detected and protected. The conventional anti-islanding methods have NDZ(None-Detection Zone) or power quality degradation. But PV-AF power generation system has the function of not only shunt active filter but also anti-islanding method without NDZ. In this paper, a novel anti-islanding method for PV-AF system is proposed and analysed in detail.

• Journal of Advanced Marine Engineering and Technology
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• 제38권5호
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• pp.589-601
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• 2014

Natural gas hydrate (NGH) is emerging as a new eco-friendly source of energy to replace fossil fuels in the 21st century. It is well known that the Natural Gas Hydrate contains large amount of natural gas about 170 times as much as its volume and it is easy to be stored and transported safely at about $-20^{\circ}C$ under atmospheric pressure due to so called "self-preservation effect". The option of gas transport by gas hydrate pellets carrier has been investigated and developed in various industry and academy. The natural gas hydrate pellet carrier is on major link in a potential gas hydrate process chain, starting with the extraction of natural gas from the reservoir, followed by the production of hydrate pellets and the transportation to an onshore terminal for further processing or marketing. In recent years, Korean project team supported by Korean Government has been working on the development of NGH total systems including novel NGH carrier since 2011. In order to increase the knowledge on the NGH pellet carrier developed and to understand the major hazards that could have significant impact on the safety of the vessel, this paper presents and evaluates the pros and cons of cargo holds, loading and unloading systems through the analysis of current patent technology. Based on the proven and well-known technologies as well as potential measures to mitigate sintering and minimize mechanical stress on the hydrate pellet in the self-preservation state, this study presents the conceptual and basic design for NGH carrier.

• 한국치위생학회지
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• 제17권6호
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• pp.1095-1107
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• 2017

Objectives: This study was designed to provide raise awareness of the guidelines associated with radiation, including those associated with ensuring safety at dental clinics. Methods: A survey was conducted on the degree of awareness on dental radiation among adults over age 20 in Seoul and Gyeonggi Province from December 2016. The questionnaire copies from 21 respondents whose answers were insincere were excluded from analysis. A total of 320 copies, equivalent to 93.4% of the total data collected, were used in the analysis. Results: Dental radiography was found to have been experienced by 60. 5% of the subjects, and 83.4% of them did not receive any explanation to the radiation exposure, while 78.7% had no experience wearing protective equipment. As a result of investigating factors affecting the recognition of dental radiation, it was found that female subjects had a higher awareness of the hazards associated with dental radiation hazard and the necessity to provide information. Conclusions: It is necessary to educate the dental medical personnel to raise awareness on radiation exposure and the need for protective equipment, especially when checking for pregnancy.