콘크리트 중의 염소이온 확산 특성에 관한 실험적 연구

박승범(Park, Seung-Bum),김도겸(Kim, Do-Gyeum) 한국콘크리트학회 2000 콘크리트학회논문집 Vol.12 No.1

요통환자와 정상인 집단 간 요부 신근력과 신체조성에 대한 비교 분석

박승순(Park Seung-Soon),한길수(Han Gil-Soo),김건도(Kim Gun-Do),이광수(Lee Kwang-Soo),이경주(Lee Kyoung-Ju),임동춘(Lim Dong-Chun) 한국체육과학회 2010 한국체육과학회지 Vol.19 No.2

This study was compared and analyzed 74 low back pain patients (male: 36, females: 38) in their 20s and 65 healthy people (male: 26, female: 39) on lumber extension strength and body composition factors. Independent sample test was used in order to analyze the data. Summary of this study's conclusions are as follows. Male lower back pain patients had 77.54% and female patients had 57.99% lower maximum lumbar extension strength when compared to average people, As for lumbar extension strength depending on lumbar curve angle, male patients had average 72% lower strength in all angles and females patients had average 51% lower strengths in all angles when compared to healthy people, displaying a significant difference. Overall low back pain patients showed lower lumbar extension strength due to lack of physical activities caused by pain and in body composition factors it showed that they had smaller amount of soft lean mass and larger amount of body fat mass, percentage of fat, a bigger waist-hip ratio and BMI than the normal group.

흰민들레(Taraxacum coreanum)에서 분리한 taraxinic acid의 tyrosinase 활성저해 및 melanin 생성저해 효과

박승일(Seung Il Park),윤혜련(Hye Ryeon Yoon),신준호(Jun-Ho Shin),이성주(Sung Joo Lee),김도윤(Do Yoon Kim),이환명(Hwan Myung Lee) 한국자원식물학회 2021 한국자원식물학회지 Vol.34 No.4

흰민들레 추출물에서 분리한 taraxinic acid, dihydrotaraxinic acid 및 luteolin를 대상으로 화장품의 미백 소재로서의 이용 가능성을 조사하였다. In vitro tyrosinase 저해 활성은 100 ㎍/mL에서 대조군인 ascorbic acid는 42% 저해 활성을 보였으며, luteolin은 48%, taraxinic acid는 29%, 그리고 dihydrotaraxinic acid는 18%를 보여 luteolin이 가장 높게 나타냈다. Taraxinic acid와 dihydrotaraxinic acid는 100 ㎍/mL 이하의조건에서 B16BL6 멜라닌 형성 세포의 생존율에 영향을 미치지않았으나, luteolin은 강한 세포 독성을 나타냈다. Taraxinic acid와 dihydrotaraxinic acid가 세포 생존율에 영향을 미치지않는 농도 범위(10, 50, 100 ㎍/mL)에서 B16BL6 세포 내 멜라닌생합성 및 tyrosinase 활성을 확인한 결과 농도 의존적으로 억제하는 것으로 확인되었다. 특히 taraxinic acid는 tyrosinase inhibitor로 알려진 arbutin보다 뛰어난 저해 활성을 나타내어, 천연 기능성 미백 화장품 원료로 사용 가능성이 기대된다. This study was to investigate the Taraxinic acid from Taraxacum coreanum on tyrosinase activity and melanogenesis. In B16BL6 cell, Taraxinic acid did not show cytotoxicity even at concentrations of up to 100 ㎍/mL. In addition, tyrosinase inhibitory activity and melanogenesis inhibitory activity were confirmed by stimulation with α -melanocyte stimulating hormone (α-MSH) in the presence of taraxinic acid. Taraxinic acid was added to cells at concentrations of 10, 50 and 100 ㎍/mL and treated for 48 hours to confirm tyrosinase inhibitory activity and melanin production. The tyrosinase inhibitory activity increased in proportion to the amount of the sample, and showed an inhibitory activity of about 54.5% at a concentration of 50 ㎍/mL. Melanin production decreased in proportion to the sample amount, and it was about 62.2% at the concentration of 10 ㎍/mL. From the above results, it was found that Taraxinic acid had higher tyrosinase activity and melanin synthesis inhibitory activity in melanocyte than arbutin. The results suggest that Taraxinic acid can be utilized in natural whitening cosmetics

해양 구조물의 철근부식 예측기법 개발에 관한 연구

박승범(Park, Seung-Bum),김도겸(Kim, Do-Gyeum) 한국콘크리트학회 1999 콘크리트학회논문집 Vol.11 No.6

요추천자 시술중 뇌척수압을 간단히 측정하는 방법

박승옥(Seung Ok Park),박원(Weon Park),김도연(Do Yeon Kim),허남진(Nam Jin Huh),최광해(Kwang Hae Choi),정철주(Chul Zoo Jung) 대한소아신경학회 1997 대한소아신경학회지 Vol.5 No.1

연구배경 : 소아에서 뇌척수압은 정확한 측정이 필요한 경우는 드물지만 압력이 정상인지 증가 되었는지를 아는 것은 중요할 수 있다. 요추천자 시술 중 협조가 되지 않은 소아에게 압력계를 이용해 뇌척수압을 측정하는 것이 쉽지 않다. 이에 저자들은, 소아에서 흔히 사용되는 척수천자침으로, 뇌척수액이 떨어지는 방울 수와 시간을 뇌척수압과 연관시키는 counting period를 결정함으로써, 뇌척수업을 측정할 수 있는 간단한 방법을 발견해 보고자 본 연구를 시행하였다. 방법 : 1997년 4월부터 5월까지 본원 소아과에 입원한 환자 중 뇌막 자극증상이나 패혈증으로 뇌척수액검사를 필요로 하는 15명을 대상으로, 소아의 척수천자 시술에 가장 많이 사용되는 22-guage 3.5-inch와 23guage 3.5-inch 척수천자침을 척수강내에 삽입한 후, 먼저 압력계로 척수액 방울 수를 1분 동안 센 다음, 상호 관계를 비교해 counting period를 결정하였다. Counting period가 결정된 다음에는, 전형적으로 10명의 환아에서 먼저 counting period동안 떨어지는 뇌척수액 방울수를 뇌척수압으로 결정하고, 압력계를 이용한 뇌척수압과 비교하였다. 결과 : 22 G 3.5inch 천자침을 이용한 counting period는 40초. 23 G 3.5-inch 천자침을 이용한 coungting period는 54초였다. 일정한 시간 동안에 천자침을 통해 떨어지는 뇌척수액 방울 수를 세어서, 그것을 뇌척수압으로 결정하는 counting period를 적용해, 전향적으로 10명의 환아에서 뇌척수압을 먼저 정한 후, 다시 압력계로 측정해 본 결과와 비교해 보았더니 모든 환아에서 10% 범위 내에 있었다. 결론 : 소아에서 뇌척수압을 측정하는 방법으로 counting period가 연구되었고 전향적으로 몇 명의 환자에서 시험되어졌다. 뇌척수액을 시험관에 받으면서 counting period동안 떨어지는 척수액 방울 수를 세기 때문에, 압력계로 측정하는 것보다 시술이 간단하고, 편리하며, 압력계를 파손할 염려가 없고 비용을 줄일 수 있으며 시술 중 오염의 빈도를 줄일 수 있을 것으로 사료된다. Background: Precise measurement of cerebrospinal(CSF) pressure rarely is needed, but it is frequently helpful to know whether CSF pressure is normal or elevated. It is often difficult to measure CSF pressure by manometer during lumbar puncture in uncooperated children. The purpose of this study was to determine appropriate counting periods for two commonly used spinal needles. Methods: Fifteen infant and children(from 1½ months to 9 years of age) with sepsis or meningeal irritation sign between April 1997 and May 1997 had measured CSF pressure. In this study, No. 22 or 23-guage, 3.5-inch, sharp, beveled spinal needle with a properly fitting stylet were used. After spinal needle is inserted in the lumbar subarachnoid space, estimated CSF pressure by manometer, and then counted drops of CSF during one minute period. A counting period can be dertermined such that the unmber of drops counted will approximate the CSF pressure in centimeters of H₂O. After these times were calculated, the method was verified in patients by comparing manometric pressure to drop count. Results: Counting periods for which the number of drops equals the pressure were then established for each needle size. Counting periods were determined at 40 seconds for 22-guage 3.5-inch needles, and 54 seconds for 23-guage 3.5-inch needles. The method was prospectively tested in 10 patients by comparing drop count over the calculated counting period to manometric pressures. In all cases, drop counts were within 10% of manometric pressure. Conculsions: This conting period method enables simple, rapid estimation of CSF pressure during lumbar puncture. Because drops can be counted while fluid is collected, the technique is more convenient than manometric pressue measures. Elimination of the manometer also reduced costs and may reduce the frequency of breaks in sterile technique.

연소재 및 식품폐기물의 혼합 반응에 따른 수처리 여과재 제조 특성

박승도(Seung-Do Park),이원호(Won-Ho Lee),이민희(Min-Hee Lee) 한국지반환경공학회 2018 한국지반환경공학회논문집 Vol.19 No.5

본 연구에서는 연소재와 식품폐기물의 산업부산물을 이용하여 비점오염 수처리 여과재로 활용 가능한 여과재를 개발하였다. 첨가제 주입에 따른 공극 형성은 강도가 유지되는 전제하에 알루미늄 파우더 3%, Ca(OH)₂ 2%일 경우 기포형성이 가장 많이 발생하는 것으로 나타났다. 결합재의 적정 혼합비로서 (연소재+식품 폐기물+점토):(물유리+콜로이드성 실리카)는 7:3 이상에서 가장 효과적인 것으로 나타났으며, 온도에 따른 강도반응은 1,000℃일 경우가 효과적이다. 최적의 혼합비율은 연소재 30%, 점토 30%, 식품 폐기물 10%에서 가장 높은 강도를 보여 비점오염 수처리로 활용도가 가장 높을 것이라 판단된다. 최적 배합조건에서 제조된 여과재는 SiO₂ 65.8%, 밀도 1.4g/㎤, 공극률 25.6%, pH 9.8로 분석되었으며, 유해물질은 검출되지 않았다. 수처리에 대한 여과능을 알아본 결과 여과된 SS의 평균농도는 14.06mg/ℓ로서 SS의 제거효율은 90.63%로 나타났으며, 역세척 회복률도 97.1%로 나타났다. 이는 폐자원의 활용뿐만 아니라 경제성 및 효율성을 고려한 수처리 여과재 제조가 가능함에 따라 폐자원의 높은 부가가치화가 가능하다. The porosity formation by the addition of additives was found to be the highest in the case of aluminum powder 3% and Ca(OH)₂ 2% under the condition that strength was maintained. The optimum mixing ratio of the binder was shown to be the most effective at (Ash+Food waste+clay):(water glass+colloidal silica) 7:3, and the temperature response is most economical and effective at 1,000℃. The optimal mixing ratio is the strength in 30% of ash, 30% of clay and 10% of food waste, which is the effective in non-point pollution water treatment. Filter media produced under optimal mixing conditions were analyzed as SiO₂ 65.8%, density 1.4 g/㎤ , porosity 25.6%, pH 9.8, and no hazardous substances were detected. As a result of the filtration of the water treatment, the mean concentration of the filtered SS was 14.06 mg/ℓ, and the removal efficiency of SS was 90%, the recovery rate of the reversal is 97.1%. This enables the development of filter media considering economic efficiency and efficiency as well as the utilization of waste resources, enabling high value added of waste resources.

에멀젼에서의 잔탄검과 로커스트 빈검의 조성비에 따른 유변학적 특성에 대한 연구

박승한 ( Seung Han Park ),김도훈 ( Do Hoon Kim ),김진웅 ( Jin Woong Kim ) 한국공업화학회 2010 응용화학 Vol.14 No.2

Synergistic polysaccharide-polysaccharide interactions are attractive commercially and enjoy widespread technological exploitation (Cairns et al., 1987). Expensive polymers may be replaced by a cheaper mixture. Xanthan/LBG solution was prepared by adding the gum into hot water and further heating to 80℃ for about 30 min with continuous stirring to ensure complete solubility and to obtain a clear homogenous solution. The storage modulus(G`) and the yield stress of solutions were increased with increasing LBG ratio, which was mostly noticed between LBG ratio 0.5∼0.75. On the other hand shear thinning effect was shows at high shear on LBG ratio 0.25. Elastic modulus was increased with increasing LBG more than two times and it was enhancing suspending properties on emulsion. Since the rheological properties describe the fundamental information about the cosmetic, these results may be of help to the design of new feeling cosmetic emulsion.

폐자원활용 여과재의 비점오염 수처리제 개발

박승도 ( Seung-do Park ),이원호 ( Won-ho Lee ),이민희 ( Min-hee Lee ) 한국환경기술학회 2018 한국환경기술학회지 Vol.19 No.4

연소재와 유기성 폐기물을 이용하여 비점오염 수처리용 여과재를 개발하였다. 여과재는 산업부산물인 비산재와 바닥재를 43 %, 점토 42 %, 식품 폐기물을 10 % 배합한 후 알루미늄파우더 3 %, Ca(OH)₂ 2 %를 넣어 혼합하고, 이를 물유리와 콜로이드 실리카를 1:3으로 섞어 paste를 만든 후 배합물 : paste = 7 : 3으로 섞어 성형 후 1,000 ℃에서 1시간동안 소성하여 제조하였다. 최적 배합조건에서 제조된 여과재는 SiO₂ 59.7 %가 가장 많이 함유되어 있었으며, 밀도는 1.2 g/㎤로 나타났으며, 마모율 40.3 %, 공극율 30.3 %로 나타났고, 유해물질은 검출되지 않았다. 여재의 제거효율은 개발 여재 80.1 ∼ 82.0 %, A사 여재 82.2 ∼ 84.5 %로 나타났으며, 여과재에 대한 역세척 회복율은 개발 여재와 A사 여재 모두 약 97 %의 세정효율을 보였다. 여과재 개발로 폐자원의 활용뿐만 아니라 경제성 및 효율성을 고려한 수처리 여과재 제조가 가능함에 따라 폐자원의 높은 부가가치화가 가능하다. In this study, we developed a filtering media that can be used as non-point pollution water treatment by using industrial by-products of ash and organic waste. The optimal mixing ratio is the strength in 43 % of bottom ash and fly ash, 42 % of clay and 10 % of food waste. and the binder was shown to be the most effective at (Ash+Food waste+clay):(water glass+colloidal silica) 7:3, and the temperature response is most economical and effective at 1,000 ℃. Filtering media produced under optimal mixing conditions were analyzed as SiO₂ 59.7 %, density 1.2 g/㎤, abrasion rate 40.3 %, porosity 30.3 % and no hazardous substances were detected. The removal efficiency of filter media was 80.1 ∼ 82.0 % for development filter media and 82.2 ∼ 84.5 % for filter media A, and the backwash recovery rate for filter media was about 97 % for both developed and A filter media. This enables the development of filter media considering economic efficiency and efficiency as well as the utilization of waste resources, enabling high value added of waste resources.

강교량의 용접불량에 따른 안전도 분석

박승범,방명석,김도겸,Park, Seung-Bum,Bang, Myeung-Sug,Kim, Do-Gyeum 한국구조물진단유지관리공학회 1997 한국구조물진단유지관리공학회 논문집 Vol.1 No.2

Nondesructive test and structural analysis have been conducted to assess the safety of weld defective steel bridges in service. In the nondestructive test, using the radioactive ray and ultrasonic, the defective welding patterns in the steel bridges are identified. A major defective welding pattern is identified as the lack of welding area due to the insufficient welding penetration. By considering the welding defect in the above, structural analysis is conducted to evaluate the influence of welding defect on the safety of steel bridges. The results indicate that, due to the insufficient welding penetration, the stress obtained in the analysis is over the allowable fatigue stress level, and its influence on safety of the bridges is significant.

자기결합 방식을 이용한 Three-Level 컨버터에 관한 연구

박승하(Seung-Ha Park),김용(Yong Kim),권순도(Soon-Do Kwon),배진용(Jin-Yong Bae),이동현(Dong-Hyun Lee) 대한전기학회 2010 대한전기학회 학술대회 논문집 Vol.2010 No.7

This paper present the Three-Level converter using IM(Integrated Magnetics) method for high power application. In power conversion system, magnetic components are important devices used for energy storage, energy transfer, galvanic isolation and filtering. The proposed Three-Level converter is to reduce the number of magnetic components using transformer integrated with output inductor. This paper proposes reluctance model base on the magnetic analysis for the Three-Level converter. Also, the secondary rectification was discussed by a single core transformer winding.