• 한국화재소방학회논문지
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• 제22권3호
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• pp.258-264
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• 2008

본 논문에서는 산불의 한 형태인 지표화의 체계적인 연구를 위해 열량분석과 연소특성에 관한 실험방법과 측정 시스템을 제안하여 향후 산불 관련 연구에 있어서 이를 활용하고자 한다. 또한 제안된 방법과 시스템의 효용성을 나타내고자 부분적인 결과를 논문에 제시 하였다. 이를 위하여 지표화의 대표적인 연소 물질인 침엽수종과 활엽수종 낙엽을 선정하여 밀도 및 시료의 용기 크기를 변화시켜 가며 실험하였다. 열량분석은 통상 사용되는 분석기기 중 열중량 분석기(TGA : Thermogravimetric Analyzer), 연소열 측정장치(Oxygen Bomb Calorimeter)를 이용하여 분석하였으며, 연소특성은 기존의 이론적 모델로 가장 잘 알려져 있는 Pool fire모델에 따른 모의 연소실험을 통하여 지표화 상부의 열 유체속도, 연소온도, 화염 높이에 따른 열방출 속도, 연소 질량감소 속도 둥을 측정하여 분석하였다. 언급된 변수들은 지표화의 위험성 및 산불확산 예측에 기초 자료로 사용할 수 있다.

• 대한치과의사협회지
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• 제55권4호
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• pp.276-283
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• 2017

Maxillary sinus squamous cell carcinoma is a relatively rare disease, comprising only 3% of malignant diseases of head and neck. As the growth rate is high and its prognosis is poor compared to others, the 5-year survival rate of maxillary sinus squamous cell carcinoma(MSSCC) is 23.4-49%. We introduce two rare clinical cases of squamous cell carcinoma originated from maxillary sinus of which symptoms include toothache and gingival swelling. On clinical examinations of both patients, deep periodontal pockets on upper right posterior teeth were detected. On panoramic images, the bony destruction of the maxillary sinus and its surrounding structures were not obvious and only alveolar bone loss was noted. It is difficult to diagnose MSSCC at an early stage due to symptoms of tooth pain and gingival swelling that are similar to that of periodontal diseases. However, if the symptoms do not improve after routine treatment of upper teeth, dentists should bear in mind of underlying malignant mass as differential diagnosis, thus early detection of the lethal disease. The aim of this study is to caution dental practitioners that malignancies have a potential to mimic periodontal diseases by introducing two cases of maxillary sinus squamous cell carcinoma presented as periodontitis.

• 공업화학
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• 제24권2호
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• pp.208-213
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• 2013

본 연구에서는 인계 난연제가 첨가된 연질 폴리우레탄 폼을 합성하여 난연제의 종류에 따른 난연성능 변화를 고찰하였다. 난연제로는 Tetramethylene bis(orthophosphorylurea) [TBPU]와 Phosphinyl alkylphosphate ester [CR-530], Resorcinol bis diphenylphosphate [RDP], Triethyl phosphate [TEP] 등을 사용하였다. 열중량분석기를 사용하여 난연제에 따른 폴리우레탄 폼의 열분해거동을 알아보았으며, 콘칼로리미터를 이용하여 열방출량, 질량감소율, 연기발생량, CO 및 $CO_2$ 발생량 등을 측정하였다. TBPU가 첨가된 폴리우레탄 폼은 난연제가 첨가되지 않은 폴리우레탄 폼에 비하여 낮은 온도에서 분해가 시작되었으나 고온에서는 많은 양의 char를 생성하였다. 콘칼로리미터 시험 결과 TBPU가 첨가될 경우 평균 발열량, 최대 발열량, 유효연소열, 질량감소율, CO 및 $CO_2$ 발생량이 감소하였고 다른 난연제에 비하여 낮은 값을 나타내어 우수한 난연성능을 나타냄을 알 수 있었다.

• Journal of Ecology and Environment
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• 제34권4호
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• pp.401-410
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• 2011

We assayed the effects of simulated acid rain on the mass loss, $CO_2$ evolution, dehydrogenase activity, and microbial biomass-C of decomposing Sorbus alnifolia leaf litter at the microcosm. The dilute sulfuric acid solution composed the simulated acid rain, and the microcosm decomposition experiment was performed at 23$^{\circ}C$ and 40% humidity. During the early decomposition stage, decomposition rate of S. alnifolia leaf litter, and microbial biomass, $CO_2$ evolution and dehydrogenase activity were inhibited at a lower pH; however, during the late decomposition stage, these characteristics were not affected by pH level. The fungal component of the microbial community was conspicuous at lower pH levels and at the late decomposition stage. Conversely, the bacterial community was most evident during the initial decomposition phase and was especially dominant at higher pH levels. These changes in microbial community structure resulting from changes in microcosm acidity suggest that pH is an important aspect in the maintenance of the decomposition process. Litter decomposition exhibited a positive, linear relationship with both microbial respiration and microbial biomass. Fungal biomass exhibited a significant, positive relationship with $CO_2$ evolution from the decaying litter. Acid rain had a significant effect on microbial biomass and microbial community structure according to acid tolerance of each microbial species. Fungal biomass and decomposition activities were not only more important at a low pH than at a high pH but also fungal activity, such as $CO_2$ evolution, was closely related with litter decomposition rate.

• Transactions on Electrical and Electronic Materials
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• 제13권6호
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• pp.273-277
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• 2012

The vacuum drying process for drying of paper in current transformers was modeled with an aim to develop an understanding of the drying mechanism involved and also to predict the water collection rates. A molecular as well as macroscopic approach was adopted for the prediction of drying rate. Ficks law of diffusion was adopted for the prediction of drying rates at macroscopic levels. A steady state and dynamic mass transfer simulation was performed. The bulk diffusion coefficient was calculated using weight loss experiments. The accuracy of the solution was a strong function of the relation developed to determine the equilibrium moisture content. The actually observed diffusion constant was also important to predict the plant water removal rate. Thermo gravimetric studies helped in calculating the diffusion constant. In addition, simulation studies revealed the formation of perpetual moisture traps (loops) inside the CT. These loops can only be broken by changing the temperature or pressure of the system. The change in temperature or pressure changes the kinetic or potential energy of the effusing vapor resulting in breaking of the loop. The cycle was developed based on this mechanism. Additionally, simulation studies also revealed that the actual mechanism of moisture diffusion in CT's is by surface jumps initiated by surface diffusion balanced against the surrounding pressure. Every subsequent step in the cycle was to break such loops. The effect of change in drying time on the electrical properties of the insulation was also assessed. The measurement of capacitance at the rated voltage and one third of the rated voltage demonstrated that the capacitance change is within the acceptance limit. Hence, the new cycle does not affect the electrical performance of the CT.

• Journal of Preventive Medicine and Public Health
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• 제9권1호
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• pp.147-151
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• 1976

A study was conducted during the period of August 13 to August 18, 1974 to obtain information on knowledge and attitude of the rural area housewife toward health care and antibiotics using. Interviewed 242 housewives dwelling in Soodong and Hwado Myun, Yangju Gun, Kyunggi Do, a typical rural area in Korea and the following results are obtained: 1. Of 242 housewives interviewed, 20.2% were illiteracy, 68.2% was graduated from primary school, 9.1% from middle school and 2.5% from high school. 2. Of those interviewed, 8.7% were Christian, 5.0% Bueldist, 2.9% Confucianism, and 83.4% of those were no religious preference. 3. Utility rate according with the kind of mass media in home was 85.1% of respondants possessed radio, 16.1% of magazine, 12.8% of newspaper, and 4.1% of television. 4. In the case of patients occure in a family, 13.0% out of 242 respondants had chosen physician's clinics for inicial medical care place, 58.4% drug stores, 0.9% herb medicine and 27.7% of those had chosen folk medicine at home. 5. Antibiotics effective complaints listed by the respondants were skin diseases with 43.8%, suppurated wound 30.0%, URI like symptoms 18.2%, diarrhea 14.5%, low back pain 12.9%, fever 6.2%, loss of appetite 3.3%, all kind of diseases 2.5%, urethral discharge 2.1% and tuberculosis 0.8% respectively. 6. Only 14.7% of respondants had obtained antibiotics for medical care from physician's clinics and 85.3% of the respondants had obtained antibioties from drug store (70.7%), village shop (10.4%), and salesmen in street market without any physician's prescription. 7. Eighty-nine percent of the respondants were understanding on patient care activity as the local health subcenter but only 11.0% of those on M.C.H., 29.0% of those on family planning, 21% on vaccination, and only 6.6% on tuberculosis control activity. 8. Utility rate of the local health subcenter was 71.9% out of the patients indicated medical care of medical facilities.

• 한방비만학회지
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• 제3권1호
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• pp.49-59
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• 2003

Objectives : The purpose of this study is to evaluate the effect the of treatment in obesity clinic in east-west collaboration center, furthermore to search for how to join and improve east medicine and west medicine more closely. Methods : 37 patients were classified into four groups by Body Mass Index(BMI); normal, overweight, 1st obesity and 2nd obesity groups. Weight, BMI, body fat rate and abdominal fat rate were compared in each group by paired t-test. Results & Conclusions : In distribution of sex, male were 10(27%), female were 27(73%). Mean age was $34{\pm}13$ and the patients in twenties un the most. Among four groups, the number of End obesity groups was the most. Most patients had a preference for western medication and ear acupuncture therapy. In general we could find the correlation between the effect of obesity treatment and the degree of obesity. The more the obesity degree was, the more weight loss was.

• 공업화학
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• 제33권1호
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• pp.96-102
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• 2022

고분자전해질막 연료전지의 반응물인 수소와 산소는 기체 상태이므로, 반응물이 원활히 전달될수록 작동 전압의 손실을 줄일 수 있다. 높은 전류밀도 영역에서 산소 물질 전달이 전압 손실을 좌우하므로, 환원극 유로의 형상 변경에 대한 연구들이 진행되어 왔다. 환원극 유로 형상 중에서 유로를 막는 블록은 반응물을 다공성 매질인 기체확산층으로 강제 대류 하도록 사용되었다. 본 연구에서는 간단한 단 채널의 연료전지 모델에 블록을 배치하였다. 전산 유체역학을 사용하였고, 공기 공급 유량을 달리하였을 때 블록으로 인한 강제 대류 효과가 전압-전류 곡선과 국부 전류 밀도에 대한 영향을 연구하였다. 기체확산층으로의 강제 대류 현상을 통하여 적은 공기 공급 유량으로도 높은 전류 밀도를 얻을 수 있었다. 다수의 블록을 직렬로 배치한 경우에 1개의 블록만 배치한 것보다 강제 대류 효과를 증가시켜 높은 전류밀도를 얻을 수 있었다.

• 한국수산과학회지
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• 제55권4호
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• pp.449-454
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• 2022

The oxygen consumption rate (OCR) based on the water temperature and body size of the sea squirt Halocynthia roretzi was examined to provide quantitative information about the metabolic response of the species. OCRs were measured using a closed flow-through respirometer at four different water temperatures (10, 15, 20 and 25℃) and two different body sizes (21.4±1.1 g and 150.5±1.3 g, wet weight) with triplicates of each treatment. OCR increased as water temperature increased at both body sizes, but decreased as body size increased regardless of the water temperature (P<0.001). The effect of body size evaluated as a power function ranged from 0.8055 to 0.8884. The highest Q₁₀ values in the small and large size groups ranged from 15 to 20℃ and 20 to 25℃, respectively. The metabolic daily energy loss rate via respiration at all tested temperatures ranged from 56.2 to 106.1 J g^-1 d^-1 in the small-size group and from 44.5 to 92.0 J g^-1 d^-1 in the large-size group. Our results indicate that the metabolic response of H. roretzi highly depends on fluctuating water temperature at a given life stage.

• Journal of the Korean Wood Science and Technology
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• 제43권6호
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• pp.768-776
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• 2015

본 연구에서는 인도네시아 조림지에서 생장한 4수종의 효율적 활용방안을 마련하기 위해 콘칼로리미터법에 의해 연소특성을 조사하였다. 그 결과, 평균열방출량($HRR_{mean}$)은 비중에 비례하였으며, 총열방출량(THR) 및 연소시간(FT) 등열관련 계수도 같은 경향을 나타냈다. Albizia는 열방출 시간이 짧았고, Mindi는 4수종 중 점화시간(TTI)과 연소시간(FT)이 길어져 4수종 중 연소속도가 늦었고, 열방출 시간도 가장 길게 이어져 결국은 Mangium 수종과 비슷한 총열방출률을 나타내는 것을 확인할 수 있었다. Albizia는 공시수종 중 가장 높은 비소화면적 값을 나타내어 연기발생비율이 높았고, 반대로 Mindi는 가장 낮은 비소화면적 값을 나타내 연기발생비율이 낮았다. 초기 연기방출률은 Albizia가 높았으나 이후에는 Gmelina와 Mangium 의 연기방출률이 높아져 총연기발생량이 높게 나타났다. Gmelina는 불완전연소로 인해 연소기간 중 가장 많은 일산화탄소 연기를 생성하였고, $CO/CO_2$ 비율은 다른 수종에 비해 3배 이상 높았다.