액체구조에 관한 천이상태이론의 물에 대한 적용

박형석,장세현,Pak, Hyung-Suk,Chang, Sei-Hun 대한화학회 1966 대한화학회지 Vol.10 No.2

The partition function for liquid water is developed according to the transient state theory of significant liquid structure proposed by Pak, Ahn and Chang. This theory assumes that the molecules may possess solid-like, transient and gas-like degrees of freedom in liquid state. Although liquid water has several special properties, for example, minimum molar volume at 4^{\circ}C$, the general theory of liquid can be applied successfully. The theoretically calculated values for thermodynamic properties at the liquid temperature range and for the critical properties are in good agreement with the observed values. 박형석, 안운선과 장세헌이 제안한 액체구조에 관한 천이상태이론을 물에 적용시켜 액체상태에 있는 물의 상태합을 구했다. 이 이론은 액체의 분자가 고체와 같은 자유도, 천이상태의 자유도 및 기체와 같은 자유도를 갖는다는 것이다. 물은 4^{\circ}C$에서 그의 부피가 최소로 되는 등 특유한 성질들을 가졌지만 이 액체이론이 잘 적용된다. 이 이론을 써서 계산한 물의 몰부피, 증가압, 엔트로피, 증발열 및 일정한 압력에서의 비열 그리고 임계점에서의 성질 등은 실측치와의 좋은 일치를 보여준다.

Gravure offset용 Ag-paste제작 및 전기적 특성 조사

박형석,박헌수,공명선 한국공업화학회 2009 한국공업화학회 연구논문 초록집 Vol.2009 No.1

Offset 보상된 직렬급전구조를 이용한 마이크로스트립 슬롯배열안테나 설계와 측정결과

박형석,오이석 한국통신학회 2001 한국통신학회 학술대회논문집 Vol.2001 No.7

국소 진행성 직장암에서 수술전 방사선-화학요법

박형석,안병권,이승현,백승언 대한대장항문학회 2004 Annals of Coloproctolgy Vol.20 No.5

Purpose: Preoperative chemoradiation treatment (CCRT) for locally advanced rectal cancer has been known to be safe and effective. The aim of study is to find any correlation between tumor volume reduction and histopathologic downstaging in locally advanced rectal cancer by preoperative CCRT. Methods: A total of 16 patients of rectal cancer were selected. They had been T3,4 N (+) preoperatively staged by using a transrectal ultrasonography and pelvic MRI. Radiation was given, a total of 5,040 cGy over 5 weeks, and systemic chemotherapy was also given 5 FU 450 mg/m2 and leucovorin 20 mg/m2 concurrently intravenously during the first and the fifth week of CCRT. Surgery was done 4∼6 weeks after completion of CCRT. A 3D CT image was obtained with AcQsim PQ 5000 3D (Philips, USA). Tumor volume was measured before and after CCRT. Results: The type of operative procedures were abdominoperineal resection 7, low anterior resection 5, coloanal anastomosis 3 and Hartmann operation 1. Volume reduction was ranged from 14.6% to 84.4%. Overa 50% tumor volume reductions were in 9 patients (56.2%). Pathologic complete remission was observed in 2 patients (12.5%), who showed 72% and 58.5% tumor volume reductions. Patients showing pT and/or pN downstaging patients (N=9) had a 55.9% tumor reductions (14.6∼84.4%), and patients showing no pT and/or pN downstaging (N=7) had 51.8% volume reduction (24.7∼ 79%). Conclusions: Preoeperative CCRT has been thought to be able to decrease tumor size and volume and to increase respectability. However, among our 9 patients who showed over 50% tumor volume reductions, 3 patients did not show any T and N downstaging, which is really important for long-term oncologic outcomes.

아조기를 포함하는 vinyl sulfone 유도체의 합성 및 특성 조사

박형석,공명선 한국고분자학회 2004 한국고분자학회 학술대회 연구논문 초록집 Vol.29 No.2

유-무기 하이브리드형 습도센서의 제조

박형석,최병구,주상우,김종규,이칠원,공명선 한국고분자학회 2004 한국고분자학회 학술대회 연구논문 초록집 Vol.2004 No.04

수심이 얕은 저수지에서 용존산소 동적 모니터링을 통한 인 내부부하 평가

박형석,최선화,정세웅,지현서,오정국,전항배 한국환경영향평가학회 2017 환경영향평가 Vol.26 No.6

In these days, agricultural reservoirs are considered as a useful resource for recreational purposes, tour and cultural amenity for vicinity communities as well as irrigation water supply. However, many of the agricultural reservoirs are showing a eutrophic or hyper-eutrophic state and high level of organic contamination. In particular, about 44.7% of the aged agricultural reservoirs that constructed before 1945 exceed the water quality criteria for irrigational water use. In addition to external loading, internal nutrient loading from bottom sediment may play an important role in the nutrient budget of the aged reservoirs. The objectives of this study were to characterize variations of thermal structure of a shallow M reservoir (mean depth 1.7 m) and examine the potential of internal nutrient loading by continuous monitoring of vertical water temperature and dissolved oxygen (DO) concentration profiles in 2015 and 2016. The effect of internal loading on the total loading of the reservoir was evaluated by mass balance analysis. Results showed that a weak thermal stratification and a strong DO stratification were developed in the shallow M Reservoir. And, dynamic temporal variation in DO was observed at the bottom of the reservoir. Persistent hypoxic conditions (DO concentrations less than 2 mg/L) were established for 87 days and 98 days in 2015 and 2016, respectively, during the no-rainy summer periods. The DO concentrations intermittently increased during several events of atmospheric temperature drop and rainfall. According to the mass balance analysis, the amount of internal PO4-P loading from sediment to the overlying water were 37.9% and 39.7% of total loading during no-rainy season in 2015 and 2016, respectively on August when algae growth is enhanced with increasing water temperature. Consequently, supply of DO to the lower layer of the reservoir could be effective countermeasure to reduce nutrient release under the condition of persistent DO depletion in the bottom of the reservoir. 최근 농업용 저수지는 용수공급과 함께 지역의 관광, 문화, 위락시설 등으로 활용되고 있다. 그러나 많은 농업용 저수지들은 부영양호로 분류되며 높은 유기물 오염도를 보이고 있다. 특히, 1945년 이전에 준공된 노후화된 농업용 저수지의 44.7%는 농업용수 수질 환경기준을 초과하고 있다. 노후화된 저수지의 경우 외부기원 오염부하 이외에 누적된 퇴적물로부터 발생하는 내부부하는 영양염류 공급에 중요한역할을 한다. 본 연구의 목적은 수심이 얕은 M 저수지(평균 수심 약 1.7 m)를 대상으로 2015년과 2016년에 수심별 수온과 저층 용존산소(DO) 농도를 연속 측정하여 저층 수환경의 동적변화를 모니터링함으로써영양염류의 내부 부하 가능성을 조사하는데 있다. 또한, 물질수지해석을 통해 내부 인부하가 저수지 전체인부하량에 미치는 영향에 대해 평가하였다. 연구결과 수심이 얕은 M 저수지에서 약한 수온성층과 강한DO 성층 현상이 나타났다. 그리고, 저수지 저층에서 DO의 동적변화를 관찰한 결과, 여름철 무강우 기간동안 지속적인 저산소 (DO 2 mg/L 미만) 상태가 2015년과 2016년에 각각 87일과 98일간 발생하였다. DO 농도는 대기온도 강하와 강우발생 기간 동안 간헐적으로 증가하였다. 물질수지분석결과, 수온상승과함께 조류성장이 촉진되는 8월에는 PO4-P 내부 부하량이 무강우시 전체 부하량 대비 2015년과 2016년 에 각각 37.9%와 39.7%로써 큰 비중을 차지하였다. 따라서 지속적인 저층 저산소 상태가 유지되는 경우에는, 퇴적층의 영양염류 용출을 억제하기 위한 DO 공급 대책이 유효 할 것으로 판단된다.

원발상 간암환자에서 절제술후 간내재발에 미치는 요인분석

박형석,송시영,한광협,전재윤,문영명,강진경,박인서,민진식 大韓消化器病學會 1995 大韓消化器病學會誌 Vol.27 No.1

중합효소 연쇄반응법을 이용한 Helicobacter pylori 감염 진단과 cagA와 위염 중증도간의 상관 관계

박형석,박효진,윤상애,유기숙,정상수,이상인,박인서 大韓消化器病學會 1998 大韓消化器病學會誌 Vol.31 No.3

중증 무지외반증에서 원위 중족골 갈매기 절골술과 근위 중족골 갈매기 절골술의 결과 비교

박형석,이준영,고강열,류제홍,임재환,Park, Hyung Seok,Lee, Jun Young,Ko, Kang Yeol,Ryu, Jehong,Lim, Jae Hwan 대한족부족관절학회 2020 대한족부족관절학회지 Vol.24 No.4

Purpose: This study compared the results of proximal and distal chevron osteotomy in patients with severe hallux valgus. Several recent studies have shown that the indications for distal metatarsal osteotomy with a distal soft-tissue procedure could be extended to include severe hallux valgus. Materials and Methods: This study analyzed 127 severe hallux valgus surgeries. Of these, 76 patients (76 feet) were excluded for lack of adequate follow-up and additional procedures (Akin procedure), leaving 51 patients (51 feet) in the study. The mean age of the patients was 58 years (21~83 years), and the mean follow-up duration was 18 months (12~32 months). The patients were divided into two groups. Group 1 underwent distal chevron osteotomy, and group 2 underwent proximal chevron osteotomy performed sequentially by a single surgeon. The patients were interviewed for the American Orthopaedic Foot and Ankle Society (AOFAS) score before and one year after surgery. The anteroposterior weight-bearing radiography of the foot was taken before and one year after surgery. Results: There were no significant differences in pain and function after one year in either group. Both groups experienced significant pain reduction and an increase in the AOFAS score. Significant improvement of the hallux valgus and intermetatarsal angle corrections was observed in both groups, and the sesamoid position was similar in each group. More improvement in radiographic correction of intermetatarsal angle was noted in group 2. Both procedures gave similar good clinical and radiological outcomes. Conclusion: This study suggests that a distal chevron osteotomy with a distal soft-tissue procedure is as effective and reliable a means of correcting severe hallux valgus as a proximal chevron osteotomy with a distal soft-tissue procedure.