탄소나노튜브를 이용한 고강도 나노복합재료

박영수(Young Su Park),허몽영(Mong Young Huh),안계혁(Kay-hyeok An),김은성,강신재(Shinjae Kang) 한국자동차공학회 2008 한국자동차공학회 지부 학술대회 논문집 Vol.2008 No.11

With major causes of exhaustion and global warming of limited fossil fuel, according to policy of saveenergy and nature-friendly products, it is needed for gas milage to beb increased by compulsion regulation (Corporate Average Fuel Economy, CAFE). For this regulation solution, the diverse and hard tries such as light-weight vehicle, electric car, and fuel cell have carried out to elevate engine efficiency and to reach to a next generation zero-emission vehicle. In light-weight field, it has been tried to find or make much stronger and lighter materials or composites, magnesium alloy and carbon fiber would be a powerful candidate in metals and reinforced plastic composites for light weight vehicles. But, we here introduced carbon nanotube (CNT), which is one of the highest Young’s modulus and strength, and its nanocomposite which would be a new and powerful material to make light weight vehicle. CNT reinforced nanocomposite would solve waste disposal to make up environmental problem and have the advantage in recycling problem that would be or has been occurred in other reinforced composites.

예술프로그램을 이용한 집단치료가 청소년의 인터넷/스마트폰 중독행위에 미치는 효과 : 예비연구

장혁준(Hyeok Jun Jang),김준원(Jun Won Kim),최태영(Tae Young Choi) 대한생물치료정신의학회 2017 생물치료정신의학 Vol.23 No.3

Objectives:Internet/smartphone addiction among adolescents is an increasingly problematic social issue, but with no current systematic treatment guidelines. In this study, we have evaluated the effect of a group therapy, using art program, on adolescents’ addiction to internet/smartphone. Methods:Screening tests(Young’s Internet Addiction test, YIAT ; Korean Smartphone Addiction Proneness Scale, SAPS) were performed on students from elementary and middle schools in Daegu, the Republic of Korea. Six sessions of group art therapy were conducted among 60 students, 20 showing internet/smartphone addiction(addiction group), and 40 with no addiction to the internet/smartphone(control group). Questionnaires including the sociodemographic information, Children’s Social Support Scale(SSS) scores, and Parent-Adolescent Communication Scale(PACS) scores were completed before the intervention. Clinical scales evaluating internet/smartphone addiction(YIAT, SAPS) among the participants and their psychological dispositions were also assessed before and after the intervention. Results:There were no significant differences in the sociodemographic factors between the addiction and control groups. The averages of the SSS and PACS scores were significantly higher in the control group when compared to those in the addiction group. The addiction group revealed a statistically significant decrease in the SAPS scores and a trend towards decreased YIAT scores. Both groups showed statistically significant decreases in the state anxiety and depression scores. Conclusion:Adolescents with Internet/smartphone addiction showed improvements in addictive behavior, state anxiety, and depression after group art therapy; hence, group art therapy may be considered an alternative treat-ment method for internet/smartphone addiction among adolescents.

장기간의 중강도 트레이닝이 면역기능에 미치는 영향

김주혁,장성동,김영준 東亞大學校附設스포츠科學硏究所 2001 스포츠科學硏究論文集 Vol.19 No.-

The purpose of this study was to investigate the change of immune reaction in moderate intensity training in young males. To achieve the purpose, Six healthy young males(Age:24.3±1.23yr) were recruited for this study. Exercise training consisted of a standardized 12-wk moderate intensity running program(60%HRmax, 3day/wks and 50min/day) performed in the laboratory on a computer-controlled treadmill. Pre- and post-training blood samples were obtain before and after completion of a maximal exercise test on the treadmill. The results of this was obtained as follows: In resting monocyte and eosinophil were no significantly difference between 12weeks pre- and post- running training. Monocyte and eosinophil of post maximal exercise were no significantly difference between 12weeks pre- and post- running training. NK cell were significantly increased after maximal exercise than rest. NK cell were significantly difference to rest and after maximal exercise in pre- and post- running training.

Immobilization with Ketamine HCI and Tiletamine-Zolazepam in Cynomolgus Monkeys

Myung-cheol Kim,Sung-hyeok Hong,Soo-jin Lee,Young-suk Kim,Jae-il Lee 대한수의학회 2003 Journal of Veterinary Science Vol.4 No.2

with Ketamine HCl and Tiletamine-Zolazepam in Cynomolgus MonkeysJae-il Lee, Sung-hyeok Hong, Soo-jin Lee, Young-suk Kim and Myung-cheol Kim*Laboratory of Veterinary Surgery, College of Veterinary Medicine, Chungnam National University, Daejeon 305-764, KoreaReceived March 4, 2003 / Accepted July 2, 2003J. Vet. Sci. (2003), 4(2), 187-191JOURNAL OFVeterinaryScience*Corresponding author: Myung-cheol Kim Laboratory of Veterinary Surgery, College of Veterinary Medicine, Chungnam National University, Daejeon 305-764, Korea Tel: +82-42-821-6757, Fax: +82-42-822-4216 E-mail: mckim@cnu.ac.kr

Increased 11β-hydroxysteroid dehydrogenase type 1 contributes to barrier dysfunction in aged skin

( Beom Jun Kim ),( Noo Ri Lee ),( Chung Hyeok Lee ),( Young Bin Lee ),( Solam Lee ),( Hyun Jee Hwang ),( Eunjung Kim ),( Eung Ho Choi ) 대한피부과학회 2019 대한피부과학회 학술발표대회집 Vol.71 No.2

Background: 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) converts inactive cortisone into cortisol, an active form, and is expressed by several tissues including the skin. Excessive active glucocorticoid (GC) deteriorates skin barrier function. Objectives: To find out if 11β-HSD1 affects on the barrier function in aged skin. Methods: We have performed human and in vivo studies. We measured cortisol in stratum corneum (SC) and oral epithelium of the elderly and young. Hairless mice were used for 11β-HSD1 immunohistochemistry staining of skin and measuring skin barrier function and serum cytokines. 11β-HSD1 knock-out (KO) mice and its wild-type were used for measuring lipid synthesis related enzyme. Results: Cortisol levels were elevated in SC and oral epithelium of the elderly rather than young. The 11β -HSD1 expression was increased in immunohistochemistry stain of aged mice skin. Aged mice showed decreased transepidermal water loss (TEWL) and SC hydration, and increased SC integrity than young. Serum inflammatory cytokines including interleukin-1α, -4, -10, -31 and tumor necrosis factor-α were increased in aged mice than young. The expressions of lipid synthesis related enzymes in epidermis were elevated in KO mice and topical 11β -HSD1 inhibitor applied mice. Conclusion: 11β-HSD1 expression is elevated in aged skin. It increases active GC and then deteriorates skin barrier function.

폐플라스틱/제강 Dust 성형체의 용출안전성에 대한 연구

강영구,송종혁 한국안전학회 2003 한국안전학회지 Vol.18 No.4

In this study, We have investigated leaching characteristics of heavy metals for recycled plastic composites containing EAF(Electric Arc Furnace) dust & EAF slag. EAF dust & EAF slag used that is generated in the 3 steel-malting companies in domestic. The physical and chemical properties of EAF dust & slag was examined by measuring specific surface area, porosity, oil absorption test and chemical wetting analysis etc. Results of total analysis indicated that EAF dust, slag contained significant amount of hazardous metals such as Cu, Pb, Cd and Cr. But, In the leaching test of the recycled plastic composites containing EAF dust, slag by Korean Standard Leaching Procedure, composites shows much lower leaching concentration of heavy metals. It was concluded that the recycled plastic composites containing EAF dust, slag showed good physical and chemical characteristics. This means that the EAF dust, slag can be effectively used as a functional filler.

살충제 Monocrotophos와 Phosphamidon의 사과 중 잔류특성 평가

권찬혁,이영득 대구대학교 생명과학연구소 2003 생명과학연구 Vol.1 No.3

국내 과수재배시 사용되고 있는 2종의 유기인계 살충제인 monocrotophos와 phosphamidon에 대하여 사과 중 잔류특성을 조사하고 수확물 중 잔류수준에 대한 안전성을 평가하고자 하였다. Monocrotophos와 phosphamidon 액제를 살포시기와 회수를 달리하여 사과 과수에 살포하고 수확물 중 잔류량을 조사한 결과, 약제 최종살포일이 수확기에 임박할수록 또한 살포회수가 증가할수록 수확물 중 잔류량이 높아지는 경향을 나타냈으며, 살포회수보다는 최종살포시기가 잔류수준에 미치는 영향이 더 크게 나타났다. 사과 과실에서 monocrotophos에 비하여 phosphamidon이 더 빠른 속도로 소실되었으며 phosphamidon의 두 유효성분 중 β-이성체 보다는 α-이성체의 잔류성이 더 길게 나타났다. 살포시기와 회수에 따른 수확물 중 잔류량과 잔류허용기준을 비교할 때 현행 안전사용기준은 적합한 것으로 판단되었다. 한편 본 연구에서 새로이 확립한 monocrotophos 잔류분석법은 분석감도, 효율 및 재현성이 기존분석법보다 우수하여 일상적 잔류분석법으로서의 활용이 충분히 가능하다고 생각된다. A supervised field trial was undertaken to evaluate the terminal residue of two systemic organophosphorus insecticides, monocrotophos and phosphamidon, in apple fruits. Monocrotophos 24% SL and phosphamidon 50% SL formulations were foliar-applied two to four times at the standard rate of 0.12 and 0.25 ㎏ a.i./500 liter/10a per application for dilute spray, respectively. Apple fruits were taken at harvest and subjected to the residue analysis. Terminal residues of monocrotophos and phosphamidon in apples which ranged 0.55∼1.32 and 0.35∼1.55 ㎎/㎏, respectively, tended to be higher as shorter pre-harvest intervals (PHI) and higher number of applications were adopted. Application timing other than frequency seemed to be the critical factor to determine the terminal level of both residues. When applied in a same manner, monocrotophos was more persistent than phosphamidon in apple fruits under field condition, while α-isomer was resided longer than β-isomer between two active ingredients of phosphamidon. Considering maximum residue limits of monocrotophos and phosphamidon for apples, residue levels found in this study confirmed that current safe use standards for the insecticides could be practically employed. An analytical method newly developed for monocrotophos residues during the study showed high reproducibility superior to erratic GLC method.

구조용 데크플레이트를 사용한 연속 합성슬래브 부모멘트 영역의 균열거동

양근혁,고영우,정헌수 대한건축학회 2005 大韓建築學會論文集 : 構造系 Vol.21 No.1

The objective of this study W3" to evaluate the flexural cracking behavior in the negative moment region of continuous composite slabs reinforced with structural steel decking Main experimental variables were slab thickness and top bar ratio The slabs were tested in 2 continuous span with fixed-ends to get easy access to the negative moment region Also, Based on the distribution of interfacial bond stresses along a segment between two adjacent cracks was assumed as sin function, a simple method for predicting the spacing and width of cracks was suggested Results showed that crack spacing and width m the negative moment region of composite slabs depend mainly on the top bar ratio rather than slab thickness The predictions obtained from the proposed method arc m good agreement With experimental results

폴리올레핀계 폐플라스틱/복합filler 성형체의 난연성 및 기계적 물성 연구

강영구,송종혁 한국안전학회 2003 한국안전학회지 Vol.18 No.2

Flame retardancy and mechanical properties of recycled polyolefinic plastics/inorganic filler composite systems were investigated by using several inorganic flame retardants such as magnesium hydroxide and slag powder generated electro arc furnace. Compatibilizer used each maleic anhydride functionalized polyethylene (PE-g-MAH) and polypropylene(PP-g-MAH) or used mixture of these. The effect of polymeric compatibilizers on the properties of composites was studied by tensile and impact test, differential scanning calorimetry, morphology in the changed fracture mechanism. The improved adhesion was particularly reflected in the mechanical properties. The flame retardancy of composites was examined by measuring limiting oxygen index(LOI, ASTM D2863), smoke density(ASTM D2843) and vertical burning test(UL94). Regarding the flame retardant effect, the EAF slag powder is behaving as synergists as they are only active in the presence of magnesium hydroxide.

병렬 객체지향 표기 언어에서의 통신과 동기화를 위한 객체 관리기

권혁찬,최숙영,유우종,유관종 충남대학교 기초과학연구소 1995 忠南科學硏究誌 Vol.22 No.2

In this paper, we present the design and implementation of object manager for communication and synchronization in POOSL(Parallel Object-Oriented Specification Language). POOSL is a specification language which is based on object-oriented concepts and provides various granularities of parallelism and communication methods. An object manager handles synchronization of objects and supports three types of communication, that is, synchronous, asynchronous and future type communication. Object manager is automatically generated in the phase of translation of POOSL. We implemented the object manager using lex and yacc.