한국 노인에서 악력 저하와 관련된 요인

오병택(Byung Taek Oh),황영시(Young Si Hwang),이준영(Jun Young Lee),박상균(Sang Kyun Park),홍승완(Seung Wan Hong),서영성(Young Sung Suh),김대현(Dae Hyun Kim) 대한임상노인의학회 2017 대한임상노인의학회지 Vol.18 No.1

Background: Hand grip strength is important to identify old people with functional limitation. The objective of this study was to investigate the factors related with Reduction of Hand grip strength in Korean elderly. Methods: Korean community-dwelling elderly (n=3,598, male/female 1,577/2,021) at the first wave (2006) of KLoSA (Korean Longitudinal Study on Aging) were used for analysis. Hand grip strength was assessed with Dynamometer for 2times each arm and we calculated hand grip index. Hand grip strength, Socioeconomic status, Health related status was assessed through personal interviews by a trained interviewer with Computer Assisted Personal Interviewing (CAPI). Results: 1,684 subjects (46.8%) were classified as Low hand grip strength group (<26 kg for male, <18 kg for female). Age, sex, MMSE score, education, employment, living with spouse, social activity, depression scale (Center for epidemiologic studies depression scale, CESD-10), function (Activity of daily living, ADL), smoking, drinking, BMI (Body mass index), hypertension and diabetes was significantly related with low hand grip strength. Low hand grip strength ratio for age 70∼74 and ≥75 were 1.68 (1.40∼2.02) and 2.89 (2.39∼3.50) compare to younger age group, female was 2.04 (1.73∼2.40), cognitive impairment was 1.84 (1.57∼2.16), no exercise group was 1.34 (1.13∼1.58). Among health-related factors, alcohol consumption and diabetes were significantly higher in low grip strength group. Among physical/psychological factors, cognitive impairment (MMSE≤23), function (ADL), depression scale (CESD-10), obesity were significantly different after multivariates adjustment. Conclusion: Age, sex, education, employment, alcohol consumption, diabetes, cognitive impairment, depression scale (CESD-10), function (ADL), exercise, obesity were significantly related with cognitive decline in Korean elderly.

Flow-through column 내에서 산성광산배수로 오염된 지하수의 복원에 관한 연구

오병택 ( Byung Taek Oh ),이진호 ( Jin Ho Lee ),이평구 ( Pyeong Koo Lee ),이상혁 ( Sang Houck Lee ),이재영 ( Jai Young Lee ) 한국폐기물자원순환학회(구 한국폐기물학회) 2006 한국폐기물자원순환학회지 Vol.23 No.7

지중식 LNG 저장탱크에 설치된 측면히터의 활용

오병택(Byung-Taek OH),임기호(Ki-Ho YIM) 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.12

LNG storage tanks are classified into two types, an above-ground type and an in-ground type in accordance with whether the location of inner storage space is higher than the surface of the earth or not. It is very important to keep the frozen part around an in-ground type tank maintained soundly in operating the tank during its whole life. And it’s for preventing underground water from permeating through the outside concrete wall. On the other hand, the growth of the frozen part should be controlled by the bottom and side heater which installed at the bottom of tank and the side soil respectively. They are operated by the liquid-circulated pipes or the electrical heat-tracing cables to control the thickness of the frozen part within a designed value..But these heating equipments might stop working because of the long-time operation. To prepare for the situation like this, the bottom heater was installed with a spare one from the beginning of construction, whereas the side heater was not. Therefore, the additional installation or the alternative operation technique of the side heater should be considered.

익산천 수질시료와 저질토의 오염도 평가

서영석,조민,오병택,Seo, Young-Seok,Cho, Min,Oh, Byung-Taek 한국지하수토양환경학회 2013 지하수토양환경 Vol.18 No.1

Water quality and contamination of sediment is a growing concern in the Iksan stream of Korea. Heavy metal contamination and changes in the physicochemical properties of the stream were evaluated. Water and sediment samples were collected from six sites during the dry and rainy seasons; pH, DO, EC, ORP, turbidity, $PO_4$-P, $NO_3$-N and selected heavy metals (Cu, Pb, Ni, As, Zn, Cd, Hg) were measured. Results showed almost no change in pH between seasons. DO was highest at site 2 (~2.63 mg/L) in the dry season; EC (1,540 ms/m) was greatest at site 1 in both seasons. The ORP gradually increased from the dry to rainy season at most of the sites and was highest at site 5. Turbidity was highest at site 1 and gradually decreased from the dry to rainy season at all sites except site 3. $PO_4$-P ranged from a high of 1,193mg/L at site 1 to in the dry season to a low of ~1.2 mg/L at site 4. In contrast, $NO_3$-N was highest at site 3 in the rainy season (12,531 mg/L). Among the heavy metals measured, Cu and Zn concentrations were highest at all sediment sites. Cu and Zn are added to livestock feed to improve reproductive rates and can be carried to the stream with manure. Transport of sediment and heavy metals during the rainy season is the major source of stream contamination and it is important to continue monitoring and take necessary action in these areas.

LNG선 화물창의 개발과 관련한 구조해석

김지훈(Ji Hun Kim),오병택(Byung Taek Oh),신형철(Hyung Cheol Shin),한상민(Sang Min Han) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.3

A Study of Cryogenic-Temperature Structural Behavior for KC-1 Corner Insulation System

Kyo Kook Jin(진교국),Byung Taek oh(오병택),Ihn Soo Yoon(윤인수),Young Chul Yang(양영철) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.4-3

슬로싱 하중을 받는 한국형 LNG선 화물창(KC-1)의 보냉 판넬에 대한 구조 안전성 평가

진교국(Kyo-Kook Jin),오병택(Byung-Taek Oh),김영균(Young-Kyun Kim),윤인수(Ihn-Soo Yoon),양영철(Young-Chul Yang) 한국가스학회 2013 한국가스학회지 Vol.17 No.2

한국형 LNG선 화물창(KC-1)의 개발은 LNG선의 핵심기술인 화물창시스템의 원천기술을 확보하여 외화절감 및 조선 산업의 경쟁력을 높이는데 그 목적이 있다. 화물창 내부의 액체가 선박의 모션에 의해 생기는 슬로싱 충격하중에 대한 LNG선의 화물창의 구조 안전성 평가는 중요한 설계 요소가 되었다. 슬로싱 현상에 의한 구조 안전성을 평가하는 가장 이상적인 방법은 유체 영역과 화물창 구조의 상호 작용을 완벽하게 구현하는 것이다. 그러나 유체-구조 연성해석은 방대한 계산 시간과 결과의 정확성을 보장하기 어렵기 때문에 불규칙적인 슬로싱 압력을 삼각파의 형태로 이상화하여 구조 안전성을 평가하였다. 따라서 본 연구에서는 슬로싱 압력은 15/1000초 동안에 최대 10bar의 압력으로 가정한 삼각파로 고려하였고, 해석 결과 한국형 LNG선 화물창(KC-1)의 보냉 판넬은 슬로싱하중에 대해 구조적으로 건전한 것으로 평가되었다. The purpose of the development of KC-1 LNG cargo containment system is reduction in royalty and increase in competitiveness of shipbuilding industry. An assessment of structure safety for LNG cargo containment system under sloshing load due to ship motion has become an important design element. The ideal way is to implement fully interaction of the fluid domain and the cargo containment system. However the irregular sloshing pressure were idealized in the form of a triangular wave for safety assessment because the fluid-structure interaction analysis is taken the extensive computation time and difficult to ensure the accuracy of the results. In this study, the sloshing load was assumed to be a triangular wave with a maximum pressure of 10 bar during 15/1000 seconds. In the analytic results, the basic insulation panel of KC-1 LNG cargo containment system was assessed to be structurally safe for sloshing load.

NoMix toilet 에서 발생하는 부산물을 이용한 수용액내 (준)중금속 제거 특성 및 가능성 연구

심재홍,임정묵,김진원,김해원,오병택,Shim, Jaehong,Lim, Jeong-Muk,Kim, Jin-Won,Kim, Hae-Won,Oh, Byung-Taek 한국지하수토양환경학회 2016 지하수토양환경 Vol.21 No.1

Struvite (MgNH₄PO₄ ⋅ 6H₂O) and hydroxyapatite (HAP, Ca₁₀(PO₄)₆(OH)₂) precipitation in urine-separating toilets (NoMix toilets) causes severe maintenance problems and also reduce the phosphate and calcium content. Application of urine separating technique and extraction of by-products from human urine is a cost effective technique in waste water treatment. In this study, we extract urine calcite from human urine by batch scale method, using urease producing microbes to trigger the precipitation and calcite formation process. Extracted urine calcite (calcining at 800℃) is a potential adsorbent for removal of heavy metal(loid)s like (Cd²⁺, Cu²⁺, Ni²⁺, Pb²⁺, Zn²⁺ and As³⁺) along with additional leaching analysis of total nitrogen (T-N), phosphate (T-P) and chemical oxygen demand (COD). The transformations of calcite during synthesis were confirm by characterization using XRD, SEM-EDAX and FT-IR techniques. In additional, the phosphate leaching potential and adsorbate (nitrate) efficiency in aqueous solution was investigated using the calcinedurine calcite. The results indicate that the calcite was effectively remove heavy metal(loid)s lead up to 96.8%. In addition, the adsorption capacity (q_e) of calcite was calculated and it was found to be 203.64 Pb, 110.96 Cd, 96.02 Zn, 104.2 As, 149.54 Cu and 162.68 Ni mg/g, respectively. Hence, we suggest that the calcite obtain from the human urine will be a suitable absorbent for heavy metal(loid)s removal from aqueous solution.

Duplex ESSO 시험법에 의한 9% Ni강 취성 균열정지 특성 연구

김영균(Young Kyun Kim),오병택(Byung Taek Oh),양영철(Young Chul Yang),윤인수(Ihn soo Yoon),김재훈(Jae Hoon Kim) 한국가스학회 2020 한국가스학회지 Vol.24 No.6

취성파괴는 구조물 손상의 원인 중 하나로 대형사고로 발생할 가능성이 있다. -162℃의 초저온 LNG를 저장하는 저장탱크의 내조는 취성파괴가 발생하지 않도록 반드시 이를 확인 할 수 있도록 성능검사를 하여 건설된다. 파괴역학 관점에서는 구조물의 파괴특성을 균열생성과 균열정지로 구분하고 있다. 취성균열이 발생되지 않도록 설계하고 취성 파괴가 발생하여도 취성 파괴가 정지하는 기능이 확인되는 소재가 사용되어야 한다. 본 논문에서는 LNG저장탱크의 내조 소재로 널리 사용되는 9% Ni강 33mm, 37mm, 40mm 두께로 준비하여 취성균열정지 특성을 분석하였다. 기본적인 취성 충격 시험특성을 파악하기 위하여 샤르피 충격시험을 상온, -162℃, -196℃조건에서 수행하였다. 또한 -196℃ 환경에서 Duplex ESSO 시험을 수행하여 취성균열정지 파괴인성을 평가하고 그 결과를 분석하였다. 이러한 시험결과를 바탕으로 9% Ni강이 LNG저장탱크 내조소재로 적용되기에 충분한 균열정지 파괴인성을 가지고 있음을 확인하였다. A brittle fracture is one of the source of structural damage and can bring a fatal accident. The inner shell of LNG storage tank should be designed and applied to construction by ensure that no brittle crack will occur under -162℃ condition. In point of view of fracture mechanics brittle fracture in the structure could be referred as crack initiation and crack arrest. It should be designed no crack initiation. However, in the unlikely event of a brittle fracture occurring, a back-up function of arresting the brittle crack should be included for the design. In this paper investigated the characteristics of 9% Ni steel thick plates of having a capability of arresting brittle cracks under the thickness of 33 mm, 37mm, 40 mm. First, charpy test has performed to evaluate the fundamental brittle impact fracture property of 9% Ni steel under the temperature of 24℃, -162℃and –196℃. In addition, Duplex ESSO tests were also performed under –196℃to evaluate the capability of crack arrest for 9% Ni steel. From the experiments results, it was confirmed that all the thickness of 9% Ni steel plates exhibits sufficient brittle crack arrest fracture toughness for the application of LNG storage tank as a inner shell.

슬로싱 하중을 받는 한국형 LNG선 화물창(KC-1)의 90도 보냉 판넬에 대한 구조 안전성 평가

진교국(Kyo-Kook Jin),오병택(Byung-Taek Oh),김영균(Young-Kyun Kim),윤인수(Ihn-Soo Yoon),양영철(Young-Chul Yang) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12

The purpose of the development of KC-1 LNG cargo containment system is reduction in royalty and increase in competitiveness of shipbuilding industry. An assessment of structure safety for LNG cargo containment system under sloshing load due to ship motion has become an important design element. The ideal way is to implement fully interaction of the fluid domain and the cargo containment system. However the irregular sloshing pressure were idealized in the form of a triangular wave for safety assessment because the fluid-structure interaction analysis is taken the extensive computation time and difficult to ensure the accuracy of the results. In this study, the sloshing load was assumed to be a triangular wave with a maximum pressure of 10 bar during 15/1000 seconds. In the analytic results, the 90 degree insulation panel of KC-1 LNG cargo containment system was assessed to be structurally safe for sloshing load.