급속응고한 Al-Mg 합금의 미세조직 및 인장특성에 미치는 첨가원소의 영향

박현호,박종성,김명호 ( Hyun Ho Park,Chong Sung Park,Myung Ho Kim ) 한국주조공학회 1997 한국주조공학회지 Vol.17 No.4

N/A In order to study effects of Cu and lie on the microstructure and tensile properties of rapidly solidified Al-Mg alloys, Al-Mg-Cu-Be alloys have been rapidly solidified by inert gas atomization process. Microstructure of rapidly solidified Al-Mg-Cu-Be powders exhibited refinement and good dispersion of Be particles as increasing of solidification rate. Solidification rate of atomized powders was estimated to be about 5 × 10^(3n)C/s. Inert gas atomized Al-Mg-Cu-Be powders were hot-processed by vacuum hot pressing at 450℃ under 100 MPa and hot extruded with reduction ratio in area of 251 at 450℃. The extruded Al-Mg-Cu-Be. powders consisted of recrystallized fine A1 grains and homogeneously dispersed fine Be particles, and exhibited improved tensile properties with increase in Cu content. Al₂CuMg compounds precipitated in grain and grain boundaries of Al-Mg-Cu-Be alloys with aging heat treatment after solution treatment. Hardness and tensile properties were improved by increasing Cu content and Be addition. Compared with extruded Al-Mg-Cu powders, the extruded Al-Mg-Cu-Be powders exhibited finer recrystallized grains and improved tensile properties by dispersion hardening of Be and subgrain boundaries pinned by fine Be particles. After aging treatment, hardness and tensile properties were improved due to restricted precipitation by increasing of dislocation density around Be particles in matrix.

고온전단분쇄기술을 이용한 재생/신재 EPDM 고무 블렌드물의 특성

박현호,이창섭,나성택,Park, Hyun-Ho,Lee, Chang-Seop,Na, Seong-Toek 대한화학회 2005 대한화학회지 Vol.49 No.4

VaRTM 공법에 의한 토목용 하이브리드 섬유강화 복합재료의 제조 및 물성에 관한 연구

박현호,최현석,이정희,최혜원,권영태,강한나,이양헌,강영아,Park, Hyun Ho,Choi, Hyun Seok,Lee, Jeong Hee,Choi, Hye Won,Kwon, Young Tea,Gang, Han-Na,Lee, Yang Hun,Kang, Young Ah 한국섬유공학회 2017 한국섬유공학회지 Vol.54 No.3

A three-dimensional spacer knitted fabric (3D fabric) consisting of ultra-high molecular weight polyethylene (UHMWPE) fibers and polyethylene terephthalate (PET) monofilaments (used for ground surfaces and pile yarn) with a ratio of 80% and 20% by volume, respectively, was produced in a Raschel machine with two needle bars. A 3D fiber-reinforced plastic (3D FRP), with cylindrical holes of 20 mm and 28 mm diameter was produced by the vacuum-assisted resin transfer molding (VaRTM) method, with a 3D fabric as a reinforcement and an unsaturated polyester resin as a matrix. Milled carbon fiber particles (CP), with a diameter of $100{\mu}m$, were added into the resin as sub-reinforcement. The mechanical properties of the obtained FRPs were investigated. The apparent space fraction of the prepared 3D FRP was estimated to be approximately 47.1% (which should be a light-weight structure) and the reinforcement-to-matrix weight ratio can reach approximately 60% or more. With regard to the tensile properties of the 3D FRP, tensile strength is higher in the wale of the fabric, while elongation is higher in the course. For 3D-CP/FRP produced with 0, 5, and 10 wt% in CP content, increasing the CP content in 3D FRP makes its decomposition temperature higher and increases its storage modulus to 10 times above the higher temperature range compared to glass transition. Flexural properties and abrasion resistance are improved as the CP content in FRPs increases.

EPDM/POSS(Polyhedral oligomeric silsesquioxane) 복합재료의 물성 연구

박현호 ( Hyun-ho Park ) 한국공업화학회 2021 공업화학 Vol.32 No.4

다면체 올리고머 실세스퀴옥산 (POSS) 중 케이지 형태 8개의 아크릴레이트 그룹을 포함하는 POSS가 에틸렌-프로필렌-디엔고무 (EPDM) 과산화물 가교에서의 가교 거동, 기계적 특성에 미치는 영향 및 열 안정성 등을 조사하였다. 고무 100 phr당 0~12 phr의 POSS를 함량 별로 혼합하고 과산화물 가교제를 첨가하여 EPDM/POSS 복합재료를 만들었다. 가교 특성 결과 POSS의 아크릴레이트 그룹이 과산화물에 의해 활성화 되었고, 과산화물 가교 효율을 향상시키는 것으로 나타났다. EPDM/POSS 복합재료에서 POSS의 분산안정성은 떨어졌지만, 복합재료의 파단 강도, 신장률 및 열 안정성은 향상되었다. The crosslinking behavior of polyhedral oligomeric silsesquioxane (POSS) containing eight acrylate groups in a cage form in ethylene-propylene-diene rubber (EPDM) peroxide crosslinking, the effect on mechanical properties, and the thermal stability were investigated. An EPDM/POSS composite material was prepared by mixing 0 to 12 parts per hundreds of rubber (phr) of POSS per 100 phr of rubber by content and adding a peroxide crosslinking agent. As a result of crosslinking properties, it was found that the acrylate group of POSS was activated by peroxide and improved the peroxide crosslinking efficiency. Although the dispersion stability of POSS in EPDM/POSS composites was poor, the fracture strength, elongation and thermal stability were improved.

고온전단분쇄기술을 이용한 재생/신재 니트릴고무(NBR) 블렌드물의 가황거동 및 물리적 특성

박현호 ( Hyun Ho Park ),김준형 ( Joon Hyung Kim ),이창섭 ( Chang Seop Lee ),나성택 ( Seong Taek Na ) 한국공업화학회 2005 공업화학 Vol.16 No.6

배전계통에서 전압추정을 위한 AMI 데이터 적용방안에 대한 연구

박현호(Hyun-ho Park),조건익(Kun-yik Jo),심관식(Gwan-sic Sim),고석일(Seok-il Go),최준호(Joon-ho Choi) 대한전기학회 2022 대한전기학회 학술대회 논문집 Vol.2022 No.10

승용차의 측면 충돌시 승객 상해치 평가에 관한 연구

박현호(Park Hyun-Ho) 한국자동차공학회 1995 한국자동차공학회 학술강연초록집 Vol.- No.-

근에너지 기법과 침치료를 병행한 경련성 사경 치험 2례

박현호 ( Hyun Ho Park ),정지은 ( Ji Eun Jung ),정원희 ( Won Hee Jung ),김민철 ( Min Cheul Kim ),박회진 ( Hoi Jin Park ) 한방재활의학과학회 2008 한방재활의학과학회지 Vol.18 No.4

Objectives : The purpose of this study is to evaluate the effect of muscle energy techniques with acupuncture therapy on spasmodic torticollis Methods : The patients were diagnosed as spasmodic torticollis and treated with muscle energy techniques and acupuncture therapy and so on. We have measured cervical range of motion and visual analogue scale score before and after treatment. Results : After treatments, spasmodic torticollis was improved. Cervical range of motion and visual analogue scale score were recovered by muscle energy techniques and acupuncture therapy. Conclusions : We concluded that muscle energy techniques and acupuncture therapy was effective treatment on spasmodic torticollis.

인산 에스테르계 난연제 BDPDH를 첨가한 CPE 고무재료의 난연성 및 내열성

박현호 ( Hyun Ho Park ),이창섭 ( Chang Seop Lee ) 한국고무학회 2003 엘라스토머 및 콤포지트 Vol.38 No.1

자동차 Oil cooler용 호스를 구성하는 고무재료의 내열 및 난연성을 향상시키기 위하여 인산 에스테르계 화합물을 내열 및 난연제로 하여 제조한 염소화 폴리에틸렌(CPE) 배합고무의 가황 특성, 물리적 성질, 내열성, 난연성 및 변량효과를 조사하였다. 호스용 고무재료는 기존의 ethyleneacrylate rubber(EAR)보다 화학적 내식성과 내한성이 우수하면서도 가격이 저렴한 CPE 고무재료를 사용하였으며, 난연제는 비할로겐 축합 인산 에스테르계인 N,N`-bis-(diphenylphosphoro) diaminohexane(BDPDH)를 합성하여 CPE 고무재료와 0~30 phr 범위에서 혼련하였다. 배합고무 시편의 경도, 인장강도, 신율, 인장응력 및 열적 특성을 측정한 결과, CPE 배합고무의 유동성, 난연성, 내열성이 향상되었음을 확인하였으며, 고무재료 규격을 초과하지 않는 범위 내에서 최대의 내열 및 난연 효과를 주는 BDPDH의 배합량은 20 phr로 나타났다. Phosphoric ester compound was employed as thermal resistant and flame retardant for chlorinated polyethylene(CPE) rubber material which is used to prepare automotive oil cooler hose. Cure characteristics, physical properties, thermal resistance, and flame retardation of CPE rubber compounds were investigated. CPE rubber which has excellent properties such as cold resistance and chemical corrosion resistance, and is inexpensive in price than existing ethyleneacrylate rubber(EAR) was used to prepare a rubber compound useful for hose. A non--halogen flame retarding agent N,N`-bis- (disphenylphosphoro) diaminohexane(BDPDH), which is condensed phosphoric ester, was synthesized and it was mixed to CPE rubber material with the range of 0~30 phr. From the test results, rheological properties, heat resistance, and flame retardance of CPE rubber compounds were found out to be much increased. The optimum content of BDPDH to rubber which gives maximum effect on thermal resistance and flame retardation, within the range of tolerable specification for rubber materials, was determined to be 20 phr.

MINJUNG IN NTHE SINKING OF THE SEWOL FERRY

PARK Hyun-Ho(박현호) 장로회신학대학교 기독교사상과 문화연구원 2016 장신논단 Vol.48 No.3

2014년 4월 16일, 세월호가 침몰했다. 295명이 생명을 잃었고 9명이 실종되었으며 두 명의 잠수사가 구조작업 중에 사망했다. 이 비극적 사건의 진상규명과 세월호 침몰 이후 드러나기 시작한 한국 사회의 부조리 철폐를 촉구하는 “북미주의 한인(교포) 신학생들의 시국 성명서”가 2014년 6월 3일, 133명이 서명한 가운데 발표되었다. 그들이 성명서에 사인한 이유는 부정의와 비극 앞에서 “무엇”이라도 하기 위해서였다. 이 논문 역시 세월호 참사 앞에서 “무엇”이라도 하기 원하는 저자의 외침이다. 본 논문은 민중신학의 관점에서 세월호 침몰 사건을 이해하는 하나의 길을 제시할 뿐만 아니라 독자들로 하여금 그들 역시 “무엇”을 하기를 촉구한다. 본 논문은 민중신학의 관점에서 누가복음 10장 25-42을 해석하면서 세월호 참사의 희생자들이 우리 시대의 그리스도이며 한국 정부의 경제 일변도의 논리에 맞서서 그리스도인들과 교회가 희생자들에게 진심으로 관심을 가지고 그들을 돌봐야 한다고 주장한다. 이를 위해 본 논문은 첫째, 누가복음 10장 25-37절에서 그리스도를 상징하는 사람은 사마리아인이 아니라 강도 만난 사람이며, 둘째 민중신학의 성서 읽기를 통해 세월호 희생자들이 우리 시대의 그리스도임을 지적한다. 마지막으로 본 논문은 누가복음 10장 38-41절의 마리아와 마르다 이야기가 어떻게 우리로 하여금 한국 정부의 경제 우위의 정책에 대해 문제를 제기하도록 하는지 이야기하는 동시에, 우리 시대의 그리스도인 세월호 희생자들에게 인간으로서 받아야할 진실된 관심과 사랑을 우리가 베풀어야 한다고 주장한다. On April, 16<SUP>th</SUP> of 2014, the Sewol Ferry sank under the sea. 295 people died. 9 are missing. 2 divers died during the rescue mission. In response to this tragedy, on June 3<SUP>rd</SUP> of 2014 the Declaration of the State of Affairs was released by Korean (-American) students in theological studies in North-America with 133 signed. They signed the declaration, because they wanted to do something in the face of injustice and tragedy. This paper is another act of doing something. The paper gives a reflection on the Sinking of the Sewol Ferry from the perspective of Minjung theology and thus calls its readers to do something in response. This paper argues that Minjung theological reading of Luke 10:25-42 identifies the victims of the Seowl Ferry incident as Christ figures of our time and calls its readers to struggle against Korean government’s economy driven rhetoric and to give genuine care for its victims as humans. To demonstrate this thesis, the paper, first, presents a reading of Luke 10:25-37 and identify the victim of a robbery with Christ, instead of the Samaritan. Second, the paper shows how the victims of the Sewol Ferry as Christ figures in our time are calling us to act. Third, the paper shows how the story of Jesus, Martha and Mary in Luke 10:38-41 is a “call to action” against the Korean government’s economy driven rhetoric and to have genuine love for the victims of the tragedy as humans.