• 임산에너지
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• 제17권1호
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• pp.56-70
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• 1998

This study was carried out to investigate the structural characteristics of kraft lignin and the wood degrading characteristics, the productivity of ligninolytic enzymes and the enzymatic degradation of kraft lignin by white-rot fungi. To purify kraft lignin, precipitation of kraft pulping black liquors of pitch pine meal was done by titration with lN $H_{2}SO_{4}$ reaching to pH 2, and isolation of the precipitates done by centrifugation. The isolated precipitates from pitch pine were redissloved in lN NaOH, reprecipitated by titration with lN $H_{2}SO_{4}$, washed with deionized water, and kept ofr analysis after freeze drying. Fractionation of the precipitates in solution by successive extraction with $CH_{2}Cl_{2}$ and MeOH, and the fractionates were named SwKL, SwKL I, SwKL II, and SwKL III for pitch pine kraft lignin. The more molecular weights of kraft lignin increased, the less phenolic hydroxyl groups and the more aliphatic hydroxyl groups. Because as the molecular weights increased, the ratio of etherified guaiayl/syringyl(G/S ratio) and the percentage were increased. The spectra obtained by 13C NMR and FTIR assigned by comparing the chemical shifts of various signals with shifts of signals from autherized ones reported. The optimal growth temperature and pH of white-rot fungi in medium were $28^{\circ}C$ and 4.5-5.0, respectively. Especially, in temperature and pH range, and mycelial growth, the best white-rot fungus selected was Phanerochaete chrysosporium for biodegradation. For the degradation pathways, the ligninolytic fungus jcultivated with stationary culture using medium of 1% kraft lignin as a substrate for 3 weeks at $28^{\circ}C$. The weight loss of pitch pine kraft lignin was 15.8%. The degraded products extracted successively methoanol, 90% dioxane and diethyl ether. The ether solubles were analyzed by HPLC. Kraft lignin degradation was initiated in $\beta$-O-4 bonds of lignin by the laccase from Phanerochaete chrysosporium and the degraded compounds were produced from the cleavage of $C\alpha$-$C\beta$ linkages at the side chains by oxidation process. After $C\alpha$-$C\beta$ cleavage, $C\alpha$-Carbon was oxidized and changed into aldehyde and acidic compounds such as syringic acid, syringic aldehyde and vanilline. And the other compound as quinonemethide, coumarin, was analyzed. The structural characteristics of kraft lignin were composed of guaiacyl group substituted functional OHs, methoxyl, and carbonyl at C-3, -4, and -5 and these groups were combinated with $\alpha$ aryl ether, $\beta$ aryl ether and biphenyl. Kraft lignin degradation pathways by Phanerochaete chrysosporium were initially accomplished cleavage of $C\alpha$-$C\beta$ linkages and $C\alpha$ oxidation at the propyl side chains and finally cleavage of aromatic ring and oxidation of OHs.

• Journal of Chest Surgery
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• 제33권5호
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• pp.407-418
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• 2000

Background: With open heart surgery(OHS), it has been recognized that many postoperative complications and postperfusion syndrome are associated with the activations of complements and leulocytes. Recently, some investigators also demonstrated that interlukin-6(IL-6) linked highly with postperfusion syndrome. The puropose of this study was to investigate the sequential changes of the IL-6 and to clarify each IL-6 relationship to the complements(C3, C4) and inflammatory response following cardiopulmonary bypass(CPB). Material and Method: To determine serum levels of IL-6, complements, leukocytes, and biochemistric markers of liver and renal function, blood samples were taken from th radial artery in 30 adult patients undergoing OHS with CPB. Result: Serum IL-6 levels incrased significantly at 10 minutes after CPB-on(CPB-10) in comparison with the control levels and reached the peak at CPB-off(p<0.05). Serum complement levels declined rapidly at CPB-10 and remained at the lower levels during CPB(p<0.01). Sequential changes of IL-6 levels had positive correlations with the changes of total leukocytes and neutrophil fractions(p<0.05), but had negative correlations with lymphocyte fractions(p<0.05). Changes of C3 related postively to monocyte fractions(p<0.05). Postoperative levels of total protein and albumin, decreased significantly in comparison with the control levels(p<0.01), while the postoperative levels of AST(aspartate transaminase) and bilirubin increased (p<0.01). At CPB-off, IL-6 levels had negative correlations with total protein and albumin levels(r=-0.60, -0.47 respectively, p<0.05), whereas C3 levels had positive correlations with albumin levels(r=0.40, p<0.05). IL-6 levels, as well as neutrophil fractions, had positive correlations with aortic clamp time(ACT) and total bypass time(TBT) (IL-6; r=0.82, 0.79 respectively, neutrophil fractions; r=0.50, 0.56 respectively, p<0.05), wheres lymphocyte frations and albumin levels had negative correlations whith ACT and TBT(lymphocyte fractions; r=-0.52, -0.58 respectively, albumin; r=-0.58, -0.55 respectively, p<0.05). Conclusion: These data showed that elevated production of serum IL-6 during CPB may play a pivotal role in systemic inflammatory responses and prologed CPB period may be assosiated with more sever postperfusion syndromes.

• Journal of Chest Surgery
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• 제24권4호
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• pp.404-420
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• 1991

Surgical treatment of congenital and acquired heart disease preceded the development of accurate techniques for diagnosis, heart lung machine and cardiopulmonary bypass, intraoperative myocardial protection, operative techniques and cardiac anesthesia. For 5 years from Sep. 1985 to Sep. 1990, six hundred cases of open heart surgeries [OHS] were performed in the department of Thoracic & Cardiovascular Surgery, Pusan Paik Hospital, College of Medicine, Inje University. The results were summarized as follows. 1. The annual number of OHS[cases per year] was above 100 since 1987, and the increasing rate of cases was 23.5% per year since 1986. 2. Among the total 600 cases, there were 470 cases of congenital heart diseases and 130 cases of acquired. Age range of the congenital patients was 8 months to 44 years with the mean age of 10 years, and acquired patients was 16 to 56 years with the mean age of 36 years. 3. Among the 470 congenital anomalies, there were 429 cases of acyanotic and 41 cyanotic patients. Totally, VSD was 286 cases[60.6%], ASD 103 cases[21.9%], TOF 35 cases [7.4%], PS 20 cases [4.1%], ECD 12 cases [2.0%], Ebstein`s anomaly 3 cases [0.6%], Valsalva sinus rupture 3 cases [0.6%] and others. The appropriate one stage radical operations were applied to the all congenital cases with the result of 2.6% immediate postoperative hospital mortality rate. 4. Among the 130 acquired cases, there were 122 cases of valvular heart diseases, 6 of heart tumors [5 myxoma, one malignant histiocytoma], one of LA thrombus and one of annuloaortic ectasia. Cardiac tumors and LA thrombus were removed through the atrial septal approach. Bentall procedure was adopted to the annuloaortic ectasia case. AVR, MVR and TVA [DeVega procedure] were applied to 120 valve diseases, and there were also one of OMC and one of MVA[Jerome-Kay procedure]. 5. Among the 120 valve replacement cases, there were 87 of single valve replacement cases [AVR: 8, MVR: 79], 11 of double valve replacement [AVR+MVR: 11], 12 of MVR+TVR and 10 of MVR+AVR+TVA. The total number of implanted prosthetic valves were 141. In MVR, 45 of St. Jude Medical valves, 63 of Carpentier-Edward valves and 4 of Ionescu-Shiley valves were used. In AVR, 18 of St. Jude Medical valves and 11 of Carpentier-Edward valves were used. in MVR, 29mm and 31mm sized valves were used mostly and In AVR, 23mm sized valves were used mostly. 6. Postoperatively many kinds of complications were occurred. Among them, wound problems [30 cases], low output syndrome [29 cases], arrhythmia [20 cases], pleural effusion and pneumothorax [13 cases] were occurred frequently. The postoperative immediate hospital mortality was 3.0% in total [congenital 2.6%, acquired 4.6%].

• International Journal of Safety
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• 제3권1호
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• pp.47-52
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• 2004

Current OSH system was analyzed in this paper to explain why high fatal incidents and disasters are continuously repeated for recent years in Korea. It was found that we have Dichotomous Perceptional Misconception of prevention before accident and compensation after accident and there is a significant lack of proper feed­back reward system for OSH performance. It was assumed that no reduction of accident rate and fatality rate have not been achieved recently despite of a great effort and increased resource allocations. Some statistics for proving weak punishment were analyzed. In the current system, the will of administrative agency would have been very limited particularly in the legal aspects. The Industrial Safety and Health Act is not suitable to after-injury punishment for employer and/or corporate since it is based on a framework for enforcement of prevention. Based on these analyses, it was concluded that there was a need to consider a special law for Corporate Accountability for Fatal Accidents. Because it is necessary to consider seriously for introduction of a new legal system for after injury punishment to repair the current system where it was found lack of proper feedback system. Also, there was no proper sanction measures for corporate with the current OSH legal system, and the most urgent problem in OSH area is the high fatality rate. it is necessary to consider seriously for introduction of a new legal system for after injury punishment. Also, there is no proper sanction measures for corporate with the current OSH legal system, and the most urgent problem in OSH area is the high fatality rate.

• Safety and Health at Work
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• 제7권3호
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• pp.185-193
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• 2016

Background: Management and workers in small and medium-sized enterprises (SMEs) often find it hard to comprehend the requirements related to controlling risks due to exposure to substances. An intervention study was set up in order to support 45 SMEs in improving the management of the risks of occupational exposure to chemicals, and in using the control banding tool and exposure model Stoffenmanager in this process. Methods: A 2-year intervention study was carried out, in which a mix of individual and collective training and support was offered, and baseline and effect measurements were carried out by means of structured interviews, in order to measure progress made. A seven-phase implementation evolutionary ladder was used for this purpose. Success and failure factors were identified by means of company visits and structured interviews. Results: Most companies clearly moved upwards on the implementation evolutionary ladder; 76% of the companies by at least one phase, and 62% by at least two phases. Success and failure factors were described. Conclusion: Active training and coaching helped the participating companies to improve their chemical risk management, and to avoid making mistakes when using and applying Stoffenmanager. The use of validated tools embedded in a community platform appears to support companies to organize and structure their chemical risk management in a business-wise manner, but much depends upon motivated occupational health and safety (OHS) professionals, management support, and willingness to invest time and means.

• Journal of Chest Surgery
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• 제16권2호
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• pp.184-189
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• 1983

Between 1958 and 1982, 70 patients have undergone pericardiectomy for constrictive pericarditis at the Thoracic Department of Seoul National University Hosp. 58 males and 12 females, with an average age of 27 years [ranging 3 to 60 years], of which 55% were between 10 and 30 years old, were treated. Eight patients died, of whom 4 were in the immediate postoperative period, less that 24 hours after operation. The cause of death was myocardial failure in 3 patients and hypotension during operation in one patient. The remaining four deaths occurred between the fifth and eighteenth postoperative day, and the causes of death varied: bilateral phrenic nerves injury, congestive heart failure, dissemination of tuberculosis, and cardiac arrest. Two patients suffered from congestive heart failure pre-and postoperatively due to the associated valvular heart disease. There were 8 wound infections on which resulted in perichondritis of costal cartilages requiring segmental resection 2 months later. There was one postoperative bleeding requiring immediate reopening for bleeding control. Tuberculosis was confirmed as the cause of constrictive carditis in 27 patients [39%]. Acute pyogenic pericarditis was precursor in 8 patients [11%]. In 2 patients [2.9%], the constrictive pericarditis developed following OHS. Both suffered from congestive heart failure postoperatively due to the residual valvular heart disease. In the others, the cause of the constrictive pericarditis was considered idiopathic or non-specific inflammation.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.409-411
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• 2017

미사일 추력기 체계에 적용되는 하이드라진[$N_2H_4$]추진제는 MSDS-OHS 유해성 분류상 급성독성 물질로서 사용이 제한되고 있는 바, 다양한 대체물질이 개발 중이다. 최근 해외에서 안전성과 취급이 우수한 질산 히드록실암모늄[$NH_3OHNO_3$]과 암모늄 디나이트라마이드[$NH_4N(NO_2)_2$] 기반 단일계 액상추진제가 개발중이며, 이 물질들을 이용한 추력기 시스템 적용 시험이 진행되고 있다. 그러나 저온에서의 연로물질 산성화 반응으로 인한 디나이트라마이드[$N(NO_2)_2{^-}$] 물질의 분해는 나이트레이트[$NO_3{^-}$] 이온 생성을 촉진시키며, 부수적으로 발생하는 침전물은 촉매 및 노즐의 막힘 현상을 유발하므로 추력기 성능의 저해요인으로 작용한다. 그러므로 저온분해 방지를 위한 첨가제 조성 개발 및 열분해 특성 연구가 최근의 관심사이다. 본 연구는 합성/정제/추출한 암모늄 디나이트라마이드 산화제를 주요 조성물로 적용하였으며, 염기성 안정화제를 질량비율 4~5% 첨가하여 산성화 반응을 억제시킨 단일계 액상추진제(KMP) 형태로 제조하였다. 합성한 추진제는 시차주사열량계(DSC)를 이용하여 분해온도를 측정하여 열안정성을 평가해보았다.

• Safety and Health at Work
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• 제13권2호
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• pp.180-186
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• 2022

Background: In occupational studies, it is a known situation that technical and organizational attempts are used to prevent occupational accidents. Especially in the mining sector, if these attempts cannot prevent occupational accidents, personal protective equipment (PPE) becomes a necessity. Thus, in this study, the main objective is to examine the effects of the variables on the use of PPE and identify important factors. Methods: A questionnaire was implemented and structural equation modeling was conducted to ascertain the significant factors affecting the PPE use of mining employees. The model includes the factors that ergonomics, the efficiency of PPE and employee training, and PPE usage habit. Results: The results indicate that ergonomics and employee training have no significant effect (p > 0.05) on the use of PPE. The efficiency of PPE has a statistically meaningful effect (p < 0.05) on the use of PPE. Various variables have been evaluated in previous studies. However, none of them examined the variables simultaneously. Conclusion: The developed model in the study enables to better focus on ergonomics and employee training in the PPE usage. The effectiveness of a PPE makes its use unavoidable. Emphasizing PPE effectiveness in OHS training and even showing them in practice will increase employees' PPE usage. The fact that a PPE with high effectiveness is also ergonomic means that it will be used at high rates by the employee.

• 한국표면공학회지
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• 제33권2호
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• pp.77-86
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• 2000

In this study effects of La starting compounds and substrates on the densification of (P $b_{0.92}$L $a_{0.05}$)Ti $O_3$ thin films were investigated. After the heat treatment on platinized silicon at $650^{\circ}C$ for 30min thickness of PLT(i) thin films (from La-isopropoxide) shrank by 27%, while 33% reduction occurred for PLT (a) thin films (from La-acetate). These PLT(i) films showed less densified surface microstructure compared to the PLT (a) . Lower shrinkage of the films on platinized silicon than on bare silicon (41% and 40% for PLT (i) and PLT (a) respectively) is attributed to the earlier development of crystallinity in the film, which arrests film densification. In order to maximize sintering before crystallization, heat treatment at $400^{\circ}C$ for 3 hours followed by $650^{\circ}C$ for 30 min was attempted. This method increased the shrinkage of the PLT (i) and PLT (a) films two times and 1.5 times as much as that observed for the films heat treated at $650^{\circ}C$ for 30min, respectively. FTIR results indicated that first pyrolysis in the film is associated with the burning of acetate ligands. Condensation reaction between OHs was found to occur preferentially between $350^{\circ}C$ and $450^{\circ}C$, whereas majority of polycondensation between ROH-OH appears to occur until $300^{\circ}C$ and be completed below $450^{\circ}C$.EX>.

• 한국산업보건학회지
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• 제29권4호
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• pp.431-441
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• 2019

Objectives: The Korean Working Conditions Survey(KWCS), which has been conducted five times over the past 13 years, presents a diverse picture of Korean workers across occupations, genders, and age groups. This study summarized the use of KWCS and explored how to make the most of the KWCS by reviewing published peer-reviewed journal articles employing the KWCS data. Methods: Articles were selected in accordance with PRISMA protocol for a systematic literature review. A total of 155 articles were included in this review. Results: The number of articles utilizing KWCS data has been increasing by year. The articles were published in 40 Korean journals and 16 international journals. The journals were mainly in the field of occupational safety and health and sociology. Keywords of mental health, working conditions survey, workforce, health, exposure to risk factor, and working time were mainly highlighted. The articles were grouped by the goals of the KWCS as stated in the survey. The majority of published articles(129 articles, 83%) aimed to 'analyze relationships between different aspects of working conditions'. Fifteen articles(10%) were intended to 'identify groups at risk and issues of concern.' The number of articles to 'monitor trends' were limited. Conclusions: The findings underline the limited utilization of the KWCS. Attention to the range and scope of utilization of KWCS should be developed to address current challenges in occupational health and safety management and policy issues.