연구논문 - 고분자공업분과 / 정밀화학분과 : Polydimechylsiloxane ( PDMS , silicone rubber ) 과 Methylmethacrylate 를 이용한 Semiinterpenetrating Polymer Network 의 합성 및 구조

변홍식,황명윤,장성호 ( Hong Sik Byun,Myung Yun Hwang,Sung Ho Chang ) 한국공업화학회 1997 한국공업화학회 연구논문 초록집 Vol.1990 No.3

放射線照射에 依한 肺의 慢性變化에 關한 實驗的 硏究

邊弘植(Hong Sik Byun),朴贊一,韓萬靑 대한방사선종양학회 1983 Radiation Oncology Journal Vol.1 No.1

To evaluate late change of irradiated lung, a total of 60 rats was irradiated on right lungfield with a single dose of 2000 rads using Co-60 teletherapy unit. Follow-up roentgenographic and histopathologic study was performed three, six and twelve months after irradiation in each group of 20 rats. The results were as follows: 1. Chest roentgenographic findings in the order of frequency were pneumonic consolidation, atelectasis, and pleural effusion in 3-month follow-up group; atelectasis, fibrostreaky infiltration, and pneumonic consolidation in 6-month follow-up; and normal, and normal, and atelectasis in 12-months follow-up group. 2. Main histopathological findings were alveolar and interstitial exudates, and diffuse infiltration of inflammatory cells in 3-month follow-up group; thickening of interstitium and vascular wall in 6-month follow-up group; and interstitial fibrosis in 12-month follow-up group.

요소와 암모니움 카바메이트 수용액의 FTIR 분석

변홍식 ( Hong Sik Byun ) 한국공업화학회 1994 공업화학 Vol.5 No.4

FTIR을 이용하여 암모니움 카바메이트와 요소의 혼합액은 물론, 각각의 농도를 분석하는 방법을 연구하였다. 본 연구에서는 15% w/v 암모니아 용액을 용매로 이용하여 암모니움 카바메이트 수용액에서 발생하는 ammonium bicarbonate의 생성을 억제하였으며, 평형위치에 대한 오차를 1% 미만으로 유지하였다. 1600㎝^(-1)에서의 N-H bending에 의한 요소 흡수 피크와 1405㎝^(-1)에서의 symmetric carboxylate ion stretch에 의한 암모니움 카바메이트 흡수 피크를 이용하여 보정 그래프를 그린 후 농도 계산식을 만들었다. 농도 측정간에 대한 오차는 암모니움 카바메이트에 대하여 ±0.1% w/v이었으며, 요소에 대하여 ±0.3% w/v이었다. A method to analyse the concentration of mixture (AC/urea) and the concentration of urea or AC alone was developed. In this study, the decomposition of AC solution to ammonium bicarbonate was suppressed by using of 15% w/v ammonia as a solvent, and the error of equilibrium point was maintained less than 1%. Strong peaks at 1600㎝^(-1) for urea and at 1405㎝^(-1) for AC, corresponding to the N-H bending and symmetric carboxylate ion stretch, were used to construct calibration graph and equations for the measurement of concentration. The errors of calculated concentration were ±0.1% w/v for AC and ±0.3% w/v for urea.

골육종의 경피적 동맥내 항암화학요법 (속보)

임덕,변홍식,김기환,진수일,정진엽,이수용,Lim, Duk,Byun, Hong-Sik,Kim, Kie-Hwan,Chin, Soo-Yil,Chung, Jin-Youb,Lee, Soo-Yong 대한영상의학회 1990 대한영상의학회지 Vol.26 No.2

Intra-arterial Chemotherapy (IAC) was performed to the 34 patients with nonmetastatic osteosarcoma using Cisplatin and surgery was done in 26 cases out of 34. We analysed the therapeutic effect of IAC in the view of local control rate and distant metastasis for two and half years. local control rate was 94% on the base of the radiologic studies including simple X-ray, angiography and CT. No viable cells were observed in 50% of the cases on the pathologic examination of the surgical specimens. Distant metastasis developed in 14 cases 9415) , mainly in the lung, No significant complications occurred except each case of acute renal failure, congestive heart failure and peripheral embolism, which were improved by proper management. IAC is one of the most effective methods in controlling the regionally confined osteosarcoma, but it may be incorperated with other adjuvant protocols to decrease the chance of delayed metastasis.

재활용 PET를 이용한 고분자 몰타르의 제조 및 흡음 특성

홍병표(Byung Pyo Hong),변홍식(Hong Sik Byun) 한국고분자학회 2010 폴리머 Vol.34 No.5

재활용 PET와 fly-ash를 이용하여 두 가지 종류의 고분자 몰타르(PMM)를 제조하였다. 재활용 PET의 조성을 변화시켜 경성(rigid) polymer-modified mortar(PMM)와 연성(flexible) PMM을 제조하였다. 마찰계수 측정을 포함하는 기계적 특성과 흡음 특성을 조사하였고 상업적 PMM인 에폭시 PMM과 PET PMM을 비교하였다. 기계적 특성들의 결과로부터 경성 PMM이 상업적인 PET PMM에 비하여 우수함을 알 수 있었다. 흡음계수측정에서 경성 PMM과 연성 PMM 모두 상업적인 PMM에 비하여 매우 우수한 흡음 특성을 보여주었다. 또한, 마찰계수 측정결과는 경성 PMM이 바닥재의 활용에 적절하다는 것을 보여주었다. Two different types of polymer-modified mortars (PMM) were prepared with recycled PET and fly-ash. One is rigid PMM and the other is flexible PMM which are based on the composition of recycled PET. Their mechanical properties including friction coefficient measurement and damping characteristics such as sound absorption were investigated and compared with the commercial PMM such as epoxy PMM and PET PMM. The result from mechanical properties indicated that the rigid PMM could be competitive with the commercial PET PMM. The measurement of sound absorption coefficient showed that both rigid PMM and flexible PMM had much better damping capacity than commercial PMM. However, the friction coefficient of rigid PMM revealed that it would be suitable for the use as floor material.

중랑천 수질 관리방안

이태관(Tae Gwan Lee),변홍식(Byun Hong Sik) 한국수처리학회 2001 한국수처리학회지 Vol.9 No.1

N/A In this study, optimal managements for water quality of Jung-rang river, branch of Han river, were investigated. Abundant of fish in Jung-rang river were killed three times from April to June in 2000. Lack of oxygen, Organic substance from sediment layers in bottom of river and overflow from wastewater treatment system during rainy season were suspected of death of those fish. To solve the problems of Jung-rang river, plenty of water has to supplied to Jung-rang river. Considering several ways and current situations, discharging treated water from the wastewater treatment system to upper part of Jung-ring river is the best way to maintain the water quantity. The second way for the quality of Jung-rang river is to improve the quality of sediment or remove the sediment. Most parts of Jung-rang river are dried and their bottoms are uncovered expect rainy season. Therefore, sediment can be easily removed before the rainy season. The other way for the quality of sediment is that air or O₃ pumped into the sediment so that organic substances could be transferred to CO₂ and H₂O. Futhermore, another wastewater treatment plants are needed to build because Jung-rang wastewater treatment system were already exceeded its capacity.

Micro Filter System의 효율 향상을 위한 Auto Back Wash의 개발

이태관(Tae-Gwan Lee),변홍식(Hong-Sik Byun) 계명대학교 낙동강환경원 2002 環境科學論集 Vol.7 No.1

터어키안 및 그 주위 종양에서 이중시기 나선식CT를 이용한 조영 증강 양상의 분석

우지영,유재욱,나동규,노홍기,변홍식,Woo, Ji-Young,Ryoo, Jae-Wook,Na, Dong-Gyu,Roh, Hong-Gee,Byun, Hong-Sik 대한영상의학회 2002 대한영상의학회지 Vol.46 No.1

목적: 이중시기 나선식 CT에서 나타나는 터어키안 및 그 주위 종양의 조영 증강 양상을 알아보고자 하였다. 대상과 방법: 수술로 진단된32명의 터어키안 및 그 주위 종양을 가진 환자를 대상으로 하였다. 수막종이 17예, 뇌하수체 거대선종 6예, 신경성 종양 5예, 해면 혈관종, 연골육종, 골육종, 접형동 종양이 각 1예였다. 이중시기 나선식 CT는 초당 3 ml로 90 ml의 조영제를 주입한 후 30초와 120초 후에 조기 및 지연 횡단 영상을 얻었고,횡단면 영상을 얻은 후 관상면 영상을 얻었다. 종양의 감쇠 변화와 조영 증강 양상을 육안적으로 평가하였고,조기 횡단 영상에 대한 지연 횡단 및 지연 관상면 영상의 CT수치의 비율을 정량적으로 분석하였다. 결과: 육안적 평가에서 조기 횡단 영상에 대한 지연 횡단 영상의 감쇠 변화는 수막종17예 모두(100%)에서 감소하였고, 뇌하수체 거대선종6예 모두(100%)에서는 뚜렷한 차이를 보이지 않았으며, 신경성 종양 5예 모두(100%)에서 증가하였다.조기 횡단 영상에 대한 지연 관상면 영상의 감쇠 변화는 수막종 17예 모두(100%)에서 감소하였고, 신경성 종양 5예 모두(100%)에서 증가하였으며, 뇌하수체 거대선종 6예중 4예(66.7%)에서는 뚜렷한 차이를 보이지 않았다. 수막종, 신경성 종양, 뇌하수체 거대선종에서 계산한 CT 수치의 비율은 통계적으로 유의한 차이를 보였다 (p<0.05). 결론: 이중시기 나선식 CT에서 터어키안 과 그 주위 종양은 병리에 따라 특징적인 조영 증강양상을 나타냈다. 이중시기 나선식 CT를 이용한 조영 증강 양상의 분석은 이들 종양의 감별진단에 도움이 될 것으로 생각된다. Purpose: To assess the enhancement patterns of sellar and parasellar tumors at two-phase helical CT. Materials and Methods: Thirty-two patients with pathologically proven sellar and parasellar tumors [meningioma (n=17), pituitary mocroadenoma (n=6), neurogenic tumor (n=5), cavernous angioma (n=1), chondrosarcoma (n=1), osteosarcoma (n=1), sphenoid carcinoma (n=1)] were included in this study. Two-phase helical CT was performed after the injection of 90 mL of contrast material at a rate of 3 mL/sec. Transverse helical CT scans were obtained during the early and late phases, with scanning delays of 30 and 120 seconds, respectively. Delayed coronal images were obtained after delayed axial images. Attenuation change and the enhancement patterns of the tumors were visually assessed; the former was also assessed quantitatively as the ratio of the CT number at late-phase axial and coronal scanning to that at early-phase scanning. Results: Visual assessment of two-phase helical CT images revealed decreased attenuation in all 17 meningiomas, no change in all six pituitary macroadenomas and increased attenuation in 5 all five neurogenic tumors on late-phase axial scans as compared with early phase scans. Coronal images showed decreased attenuation in all 17 meningiomas, increased attenuation in all five neurogenic tumors and no change in four pituitary macroadenomas (66.7%). The ratio of CT numbers was significantly different between meningiomas, neurogenic tumors and pituitary macroadenomas(p<0.05). Conclusion: According to their histopathology, sellar and parasellar tumors showed characteristic enhancement patterns at two-phase helical CT. An analysis of the observed enhancement patterns can be useful in the differential diagnosis of juxtasellar tumors.

확산연소에서 과급산소가 배기가스특성에 미치는 영향

이상준(Sang Jun Lee),변홍식(Hong Sik Byun),최경호(Gyeung Ho Choi) 大韓環境工學會 1998 대한환경공학회지 Vol.20 No.12

PVD법을 이용한 전자파 차폐용 시트 제조 및 차폐효율 특성

채성정 ( Seong Jeong Chae ),홍병표 ( Byung Pyo Hong ),이병수 ( Byoung Soo Lee ),변홍식 ( Hong Sik Byun ) 한국공업화학회 2010 공업화학 Vol.21 No.5

Fe계 metal powder를 이용하여 최적화된 전자파차폐 시트를 제조한 후, 제조된 시트에 physical vapor deposition (PVD) 법으로 여러 금속들을 증착시켜 최종 전자파차폐용 시트를 제조하였다. 또한 증착된 금속들의 전자파 효율 특성을 분석하기 위하여 polyvinylidene fluoride (PVdF) 나노섬유 막을 시트로 활용하였다. 전기적 특성을 알아보기 위해 4-point probe로 측정하였으며, energy dispersive spectroscopy (EDS)를 이용하여 제조된 sheet에 금속이 증착되었음을 확인하였다. 차폐효율은 전자파차폐효율측정기를 이용하여 측정하였다. 전기저항은 1000 Å일 때 Cu에서 641.95 Ω·cm로 가장 낮은 저항 값을 나타내었다. 전자파 차폐효율은 증착된 금속의 두께의 증가에 따라 증가되었으며, Cu가 1000 Å으로 증착된 sheet가 최고 효율인 32.5 dB을 나타내었다. The optimized sheet for EMI shielding was prepared by metal power with Fe series. Then various metal powders were deposited on the sheet by PVD method. Moreover, the PVdF nanofiber membrane was used to compare the characteristic of EMI shielding efficiency of various metal powders. The electrical property was measured by the 4-point probe method. The result from EDS confirmed that the metal powder existed on the sheet. EMI shielding efficiency was analysed by EMI shielding measurement apparatus. The lowest electrical resistance, 641.95 Ω·cm, was obtained with 1000 Å deposition of Cu on the sheet. It was revealed that the EMI shielding efficiency increased with increase of the metal deposition thickness. The sheet deposited by Cu with 1000 Å showed the highest EMI shielding efficiency, 32.5 dB.