폐타이어를 이용한 TPV(고무플라스틱) 원료 개발

윤상필,김봉석,정인경,서재건 한국폐기물자원순환학회 2013 한국폐기물자원순환학회 학술대회 Vol.2013 No.2

고무와 폐플라스틱의 경우 재활용에 있어서 가장 큰 비중을 차지하는 것은 단순 소각을 통한 열원이용으로 그 경제성은 매우 형편없는 실정이다. 자원 재활용에 있어서 경제성은 매우 중요한 척도이다. 위와 같은 열원이용은 그 처리규모와 폐자원의 형태 및 기능에 대한 제한은 없지만 초기 시설투자비용이 높고 일차원적 소각처리라는 점에서 경제적으로 많은 문제점을 지닌다. 이에 대한 대안으로 90년대 폐타이어의 가공이용 방법이 부각되기 시작하였고 고무블록 및 매트 제작을 통한 탄성바닥포장 재활용 제품으로 각광받기 시작하였다. 그러나 이 역시 폐타이어 재활용 사업을 고부가가치 사업으로 이끌기에는 부족했으며 중국산 수입 고무 칩의 무분별한 사용으로 인한 인체 유해성 문제로 그 시장이 축소되기에 이르렀다. 타이어의 구성요소인 고무와 강철은 현대 산업사회를 이끌어 가는 중요한 자원으로 이를 재자원화 하는 방안은 매우 시급한 실정이다. 현재 해외 선진사례에서는 폐타이어 고무 칩의 미 분쇄를 통하여 이를 재자원화하는 연구개발이 이루어지고 있다. 특히 폐자원을 활용한 복합신소재 개발은 자동차 부품 및 스포츠 용품, 의료용 소재, 기계부품 등과 같은 다양한 분야에 응용이 시도되고 있다. 본 연구에서는 폐타이어 재활용에 일반적으로 사용되고 있던 Cutting방식에 Shear방식을 도입, 칼날의 모양 및 분쇄드럼 개선을 통하여 기존 분쇄기보다 효율성을 증대시켜 미세 분말(0.5 mm이하) 형태의 고무플라스틱 재생 원료를 생산하는 기술을 개발하였고 또한 폐타이어에 함유된 철심은 재자원화가 가능하도록 하는 분리・선별 process를 구축하였다.

바지락 치패발생장 조성을 위한 모래살포가 저서동물 군집구조에 미치는 영향 (태안군 고남면 옷점 갯벌 사례)

윤상필,송재희,최윤석,박광재,정상옥,한형균 한국패류학회 2014 The Korean Journal of Malacology Vol.30 No.3

This study was conducted to investigate the impact of sand addition to an intertidal for the development of the Manila clam habitat on benthic community structure. For this, we focused on the spatio-temporal changes in the surface sediment condition and benthic community structure including Manila clam before and after the event. Study site was the lower part of Ojjeom tidal flat in Gonam-myeon, Taean-gun where sand added to on July 2010. We set three stations at each of sand adding area (experimental plot) and non sand-adding area (control plot) and did sampling works ten times from June 2010 to October 2011. Directly after the event, surface sediments changed to very coarse sand, but the state was not maintained over two months because of seasonal sedimentation and finally got back to the original grain sizes in eight months. The number of species and density were temporarily reduced right after the event and polychaetes such as Sternaspis scutata, Ampharete arctica were most negatively affected by the event. However, the number of species and density quickly recovered from the reduction in four to six weeks owing to the recolonization by the existing species and species in the vicinity of the plot. However, despite the recovery of ecological indies, species composition was continuously changed from one to another, thereby community structure stayed unstable condition, especially in some stations with finer sediment in their original condition. After sand addition, density of Manila clam was prominently increased at only one station with coarser sediment in its original condition.

정밀 윤곽가공을 위한 적응 교차측 연동제어기

윤상필,지성철 한국공작기계학회 2000 한국공작기계학회 추계학술대회논문집 Vol.2000 No.-

In this paper, a new adaptive cross-coupling control (ССС) method with an improved contour error model is proposed to maintain contouring precision in high-speed nonlinear contour machining. The proposed method utilizes variable controller gains based on the instantaneous curvature of a contour and the feedrate command. In addition, a real-time federate adaptation scheme is included in the proposed ССС to regulate cutting force. The proposed method is evaluated and compared with the conventional ССС for nonlinear contouring motion through computer simulations. The simulation results show that the proposed ССС improves the contouring accuracy and regulates cutting force more effectively than the existing method.

Estimation of the Radiation Field Distribution Induced by Beam Loss at the 100-MeV Proton Linear Accelerator

윤상필 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.7

The Proton Engineering Frontier Project has been constructing a 100-MeV Proton Linear acceleratorfor completion in 2013 and the accelerator design has been carried out with the objectiveof limiting beam losses to less than 1 W/m during normal operation. If accidental beam loss is tobe prevented a beam loss monitor has to be installed along to the linear accelerator. Thus, to determinethe dynamic ranges and the installation intervals of the beam loss monitors, we calculatedthe radiation field distribution by using the Monte Carlo Method not only during continuous beamloss for normal operation but also dose during accidental beam loss. The calculation results showthat the intensity of neutron dose was higher than that of the gamma. The lateral distribution ofneutrons was wider than that of photons.

Dosimetry of a Low-energy Proton Beam Using a Plane-parallel Ionization Chamber in the 45-MeV Proton Beam Test Irradiation Facility

윤상필,홍인석,박범식,조용섭 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.22

For the measurement of the absorbed dose in the 45-MeV proton beam test irradiation facility, and air filled ionization chamber technique recommended by the IAEA international code of practice TRS 398 for clinical dosimetry was tested for a radiobiological effect experiment using a proton beam. This work aimed to obtain a calibration factor suitable for our irradiation facility. Applying the TRS 398 protocol, we introduced at this facility the concept of the absorbed dose to water. A parallel-plane Markus ionization chamber and a water phantom were used for proton beam dosimetry. To determine the reference absorbed dose to water for the proton beam, we obtained the beam quality index R_(res) and the beam quality correction factor k_p measuring the depth-to-dose distribution of the proton beam in water. Measurements were made in modulated and unmodulated beams. For the modulated beam, the beam correction factor k_p was 1.00472, and for the unmodulated beam, the beam correction factor k_p was 1.004.

Evaluation of Radiation Damage Induced by a Proton Beam at the KOMAC Facility

윤상필 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.3

The 100-MeV proton linacs of the Korea Multi-purpose Accelerator Complex (KOMAC) startedmachine operation in 2013, and a 20-MeV or a 100-MeV proton beam has been provided to userswho want to utilize a proton beam for their research and development at the KOMAC. Under protonbeam irradiation, the target material will experience radiation damage induced by the proton beam,and this radiation damage can be evaluated as a function of the displacement per atom (DPA). Therefore, we used the SRIM (stopping and range of ions in matter) to investigate the damagerate induced by a 20-MeV or a 100-MeV proton beam. In this paper, we will introduce the resultsobtained by using SRIM calculation, for the radiation damage as a function of the proton energy,beam current, target material and target dimension.

폐경 후 여성에서 흡연이 골다공증성 척추 골절에 미치는 영향

윤상필,이승환,박병문,송경섭,장근,이범석,이환모,문성환 대한척추외과학회 2016 대한척추외과학회지 Vol.23 No.1

Study Design: A retrospective study. Objectives: To evaluate the association between smoking and osteoporotic vertebral fractures (OVFs) in postmenopausal women. Summary of Literature Review: Several studies have examined the relationship of smoking with hip fractures, but few studies have analyzed the relationship of smoking with spine fractures in women thus far. Materials and Methods: This study considered 1255 postmenopausal women aged 50 years and older (enrollment from April 2008 to January 2009) from 62 study sites in a nationwide hospital. The amount of smoking was calculated in pack-years. Further, OVFs were diagnosed using a semi-quantitative method. To analyze the relationship between smoking and OVFs, we used a paired t-test, a χ2-test, and a binary logistic regression analysis. Results: The past history of smoking was 7.2% in the patient group and 4.3% in the control group (p=0.025). The mean pack-years of smoking was 0.34 in the control group and 0.62 in the patient group (p=130). The mean T-score in the lumbar bone mass density (BMD) was –1.64 in the control group and –2.19 in the patient group (p=0.409). Smoking was a risk factor of vertebral fractures in postmenopausal women (odd’s ratio=1.68, 95% confidence interval=1.020–2.759, p=0.042) irrespective of the lumbar BMD and the medical treatment for osteoporosis and obesity. Conclusions: Smoking is a risk factor for osteoporotic vertebral fractures in postmenopausal women independently without regard to lumbar BMD. Therefore, cessation of smoking is important for the prevention of OVFs in postmenopausal women. 연구 계획: 후향적 연구. 목적: 폐경 후 여성에서 흡연이 골다공증성 척추 골절과 골밀도에 미치는 영향을 분석하고자 하였다. 선행문헌의 요약: 흡연이 골밀도를 낮추고 골대사에 해로운 작용을 하며 특히 고관절부의 골다공증성 골절의 발생률을 증가시키는 것은 기존의 여러 논문을통하여 알려진 바 있다. 그러나 여성 환자에서 척추 골절의 발생에 대한 흡연의 영향에 대해서는 연구된 바가 거의 없었다. 대상 및 방법: 1255명의 50세 이상 폐경 후 여성을 대상으로 흡연력을 갑년 단위로 조사하였다. 척추 골절의 진단은 흉요추부 측면 방사선 사진에서 반정량적 방법을 이용하여 진단하였다. 대상군을 척추 골절이 한 개 이상 있는 골절군과 척추 골절이 없는 대조군으로 나누어 두 군간의 차이를 통계학적으로 분석하였다. 결과: 흡연력의 경우 골절군에서 7.2%였으며, 대조군에서 4.3%로 골절군에서 유의하게 높은 것으로 나타났다(p=0.025). 평균 흡연 갑년수는 골절군에서는0.63갑년, 대조군에서는 0.34갑년이었으며, 통계학적으로 유의한 차이는 없었다(p=0.130). 흡연력은 골다공증성 척추 골절의 주요한 위험인자로 나타났으며 골다공증 여부, 골다공증 치료 기왕력, 비만의 여부 등을 통제하였을 때, 비흡연자에 비해 척추 골절의 발생을 1.68배 높이는 것으로 나타났다(OR 1.68, 95%CI 1.020-2.759, p=0.042). 결론: 흡연력은 폐경 후 여성에서 골밀도와 상관 없이 척추 골절의 유의한 위험 인자로 나타났다. 여성에서 금연이 척추 골절의 예방을 위해 필요할 것으로 생각된다.

재발성 전두동염 환자에서 수술항해기구를 이용한 Modified Lothrop 수술 사례 1예

윤상필,백삼현,이경규,김학수 대한이비인후과학회 부산,울산,경남 지부회 2011 임상이비인후과 Vol.22 No.2

In recurrent chronic frontal sinusitis, the representative Modified Lothrop procedure is less invasive compared to classic extranasal approach, but CSF leakage and orbital injury occur often, and it has technical difficulties. On the other hand, a navigation device was recently adopted for endoscopic sinus surgery in otorhinolaryngology department. Endoscopic sinus surgery using the Navigation device can reduce intraoperative complications and recurrence. Researchers of this study report on the case of recent Modified Lothrop procedure in patient with recurrent frontal sinusitis by use of navigation, along with references.

'의생명과학' 현황 분석 및 제언

윤상필,Yoon, Sang-Pil 제주대학교 의과학연구소 2018 The Journal of Medicine and Life Science Vol.15 No.1

'The Journal of Medicine and Life Science' renewed editorial board and guidelines for authors, and opened online submission system (http://www.jops.co.kr/ojms/JMLS). Herein I, editor-in-chief of 'The Journal of Medicine and Life Science', did self-assessment on the history and current status of the journal and suggested perspectives on the journal.

갑상샘기능저하증에 따른 생식샘기능저하증 모델 정립을 위한 제언

윤상필,김정우,Yoon, Sang-Pil,Kim, Jung Woo 제주대학교 의과학연구소 2019 The Journal of Medicine and Life Science Vol.16 No.1

Hypogonadism is a clinical syndrome that results in hormone deficiency and can be classified as 1) primary caused by the gonadal failure and 2) secondary by the hypothalamus-pituitary gland dysfunction and/or cardiometabolic complications. Recently the presence of thyroid hormone receptors in different testicular cell types was demonstrated, and thus thyroid dysfunctions would be another cause of secondary hypogonadism. Thus, we investigated the effects of perinatal hypothyroidism on hypogonadism in male Sprague-Dawley rats. Perinatal hypothyroidism was induced by daily administration of 0.05% 6-propyl-2-thiouracil (PTU) by tap water from gestation day 15, which were compared with negative control (PTU (-)) group. At postnatal day 28, hypothyroid pups were divided into 2 groups: PTU (+) group - continued PTU treatment and PTU (+/-) group - stopped PTU until postnatal day 49. Body weights, dehydrotesosterone (DHT), and testosterone levels were checked 2 and 3 weeks after grouping. Body weights were significantly decreased in PTU(+) and PTU(+/-) groups compared with PTU (-) group at postnatal day 28. 3 weeks later, PTU (+/-) group significantly gained weight compared with PTU (+) group. DHT and testosterone levels significantly decreased with PTU treatment, but increased 3 weeks after stopping PTU administration. Perinatal PTU-induced hypothyroid hypogonadism was sustained for 2 weeks after stopping PTU administration, but restored gonadal hormone levels 3 weeks after stopping PTU. These results suggest that researchers should design an experiment on hypothyroid hypogonadism based on the estimated period.