사과의 분광반사 특성과 비파괴 품질평가인자와의 상관관계 구명

김용현,김철수,김성봉,김몽섭,신건철 ( Y . H . Kim,C . S . Kim,S . B . Kim,M . S . Kim,K . C . Shin ) 한국농업기계학회 1992 바이오시스템공학 Vol.17 No.4

트랙터 전·후진 변속 제어 기술 개발 동향

김용현,김택진,김용주,Kim, Yong Hyeon,Kim, Taek Jin,Kim, Yong Joo 유공압건설기계학회 2020 드라이브·컨트롤 Vol.17 No.1

2단열처리를 이용한 고연신율 고장력 강판의 개발

김용현,김영훈,김한군 ( Y . H . Kim,Y . H . Kim,H . G . Kim ) 한국열처리공학회 1997 熱處理工學會誌 Vol.10 No.1

The variation of the mechanical properties and the formation of retained austenite with heat treatment conditions in austempered Si bearing carbon steels has been investigated. In the case of a steel containing 0.35C-1.48Si-0.95Mn, it has been found that a feather shape bainite structure of lath are obtained under a isothermal treated condition at just below the Ms temperature, and the martensite, bainitic ferrite and retained austenite of second phase particles on the ferrite matrix for a isothermal treated steels after intercritical annealing are precipitated in a linked shape. The retained austenite with 2㎛ size induced as TRIP is found to increase with increasing the formation rate of retained austenite for the intercritical annealing and high Si containing steels. The tensile strength is increased as austempering temperature increases in all isothermal treatment temperature, whereas the elongation is shown to roughly decrease as the tensile strength increases. The values of tensile strength-elongation balance have showed a marked dependence upon the elongation rather than the tensile stregth, and their values are increased for high Si containing steels and intercritical annealing condition. The most optimum result has been shown to be the tensile stregth-elongation balance of 2882.4kgf/㎟.% and the elongation of 33.3% for a B steel in the heat treating temperature range of 780∼370℃.

당분흡수 억제제

김용현,Kim, Yong-Hyeon 사단법인 한국당뇨협회 2006 당뇨 Vol.204 No.-

Zr₂WP₂O₁₂ 세라믹스의 합성과 소결거동 연구

김용현,김남옥,이상진,Kim, Yong-Hyeon,Kim, Nam-Ok,Lee, Sang-Jin 한국세라믹학회 2012 한국세라믹학회지 Vol.49 No.6

$Zr_2WP_2O_{12}$ powder, which has a negative thermal expansion coefficient, was synthesized by a solid-state reaction with $ZrO_2$, $WO_3$ and $NH_4H_2PO_4$ as the starting materials. The synthesis behavior was dependent on the solvent media used in the wet mixing process. The $Zr_2WP_2O_{12}$ powder prepared with a solvent consisting of D. I. water was fully crystallized at $1200^{\circ}C$, showing a sub-micron particle size. According to the results obtained from a thermal analysis, a $ZrP_2O_7$ was synthesized at a low temperature of $310^{\circ}C$, after which it was reacted with $WO_3$ at $1200^{\circ}C$. A new sintering additive, $Al(OH)_3$, was applied for the densification of the $Zr_2WP_2O_{12}$ powders. The cold isostatically pressed samples were densified with 1 wt% $Al(OH)_3$ additive or more at $1200^{\circ}C$ for 4 h. The main densification mechanism was liquid-phase sintering due to the liquid which resulted from the reaction with amorphous or unstable $Al_2O_3$ and $WO_3$. The densified $Zr_2WP_2O_{12}$ ceramics showed a relative density of 90% and a negative thermal expansion coefficient of $-3.4{\times}10^{-6}/^{\circ}C$. When using ${\alpha}-Al_2O_3$ as the sintering agent, densification was not observed at $1200^{\circ}C$.

천맥탕(天麥湯)의 알레르기 염증반응 및 기전탐색에 관한 연구

김용현,이승연,김원일,Kim, Yong-Hyeon,Lee, Seung-Yeon,Kim, Won-Il 대한한방소아과학회 2010 대한한방소아과학회지 Vol.24 No.1

Objectives The purpose of this study was to examine the pathway of anti-allergic effects of Cheonmaec-tang (CMT). Methods We examined the cell viability, $\beta$-hexosaminidase release, pro-inflammatory cytokines secretion and mRNA expressions, nuclear factor-kappa B (NF-${\kappa}B$) (p65) activation, inbibitor kappa B-alpha ($I{\kappa}B-{\alpha}$) degradation, and MAPKs activation in RBL-2H3 cells pre-treated by CMT of 2.0 mg/ml, 4.0 mg/ml separately. Results We observed that CMT reduced the secretion of $\beta$-hexosaminidase, TNF-$\alpha$, IL-4 and the expression of COX-2 mRNA in RBL-2H3 cells. Furthermore, CMT inhibited the levels of activation of NF-${\kappa}B$ (p65) protein, ERK MAPK, and degradation of $I{\kappa}B-{\alpha}$ in RBL-2H3 cells. Conclusions These results show that CMT has an anti-histamine effect and inhibitory effect of NF-${\kappa}B$ (p65) through regulation of $I{\kappa}B-{\alpha}$ degradation. These suggest that CMT could be used as an anti-allergic medicine.

경사진 평판형 밀폐 공간에서의 자연 대류 현상의 수치 해석

김용현,고학균,노상하 ( Yong Hyun Kim,Hak Kyun Koh,Sang Ha Noh ) 한국농업기계학회 1985 바이오시스템공학 Vol.10 No.1

인공광하에서 플러그묘 개체군상의 공기역학적 특성

김용현,고재풍수 (古在豊樹) ( Y . H . Kim,T . Kozai ) 한국농업기계학회 1997 한국농업기계학회 학술발표논문집 Vol.2 No.1

득량만 저서다모류군집의 공간분포

김용현,신현출,Kim, Yong-Hyun,Shin, Hyun-Chool 한국해양학회 2002 바다 Vol.7 No.1

본 연구는 남해안에 위치한 반폐쇄적인 득량만에서 저서다모류 군집분포를 파악하고 과거에 조사한 결과와 비교하면서 변화과정을 살펴보기 위해 수행하였다. 득량만은 1996년과 1997년에 걸쳐 총 98개 정점을 선정하여 조사하였다. 표층 퇴적상은 clayey silt상으로 나타났다. 전체 저서동물의 평균서식밀도는 871 ind./m$^{2}$이었다. 만 중앙역에서의 서식밀도는 종밋(musculus senhousia)과 쿠마류가 몇몇 정점에서 극우점으로 분포하였기 때문에 가장 높았다. 저서다모류의 출현종수는 100종으로 출현하였고, 서식밀도는 138 ind./m$^{2}$으로 나타났으며, 만 북단과 만 중앙역의 일부 정점, 그리고 만 입구역에서의 분포가 높았으나, 전반적으로 빈약한 군집을 형성하고 있었다. 1.0% 이상 우점한 종은 총 21종으로 전체 다모류중 78.3%를 차지하였다. 이 중 Lumbrineris longifolia(9.3%)가 가장 우점하였으며, Eteone longa(7.3%), Heteromastus filiformis (7.1%), Sternaspis scutata(6.1%)의 순으로 나타났다. 우점종을 기초한 집괴분석을 수행한 결과, 크게 3개의 정점군으로 대별되었다. 내만역과 천해연안역을 포함한 정점군 AI은 만북단역과 천해지역으로, 가장 우점한 종은 Heteromastus filiformis이었다. 정점군 AII는 만 입구역과 몇몇 수로지역으로 Lumbrineris longifolia와 Eteone longa가 가장 우점하였다. 그리고 정점군 B는 내만역과 수로지역이 맞닿는 지역으로 Sternaspis scutata가 가장 우점하였다. 과거의 연구와 비교해 보면, 저서다모류군집은 출현종수, 서식밀도와 우점종에 있어서 큰 변화를 보였다. 과거의 조사결과에서는 우점종이 Sternaspis scutata와 Eteone longa이었으나, 본 조사에서는 이 종들의 서식밀도가 감소하였다. 반면에 잠재적 유기물 오염 지시종으로 알려진 Lumbrineris longifolia와 Heteromastus filiformis가 서식밀도는 낮지만 새롭게 우점종으로 대두하였다. 이러한 사실들로 볼 때, 득량만은 한국의 다른 만들과는 달리 아직까지 오염이 덜한 해역인 것으로 사료되나, 환경관리에 주의를 요하는 것으로 판단된다. This study was carried out to investigate the composition and the distribution of the benthic polychaetous communities in Deugryang Bay, semi-enclosed bays, on the southern coast of Korea and to deduce temporal changes in community with the comparison of the past studies. In Deugryang Bay, benthic polychaetous community structure was investigated on the base of the samples from 98 stations in 1996 and 1997. The main facies of surface sediment was clayey silt. The overall benthic macrofaunal density was 871 ind./m$^{2}$. The density was highest in the middle part of the bay because Musculus senhousia (Bivalvia) and cumaceans (Crustacea) had their highest densities in some stations. Benthic polychaetes were comprised of 100 species with a mean density of 138 ind./m$^{2}$. Their abundances were higher in the inner bay, in the middle bay, and in the mouth of bay, but poor community structures were established in the whole bay. The dominant species over 1.0 percentage were composed of the total 21 species, and they occupied 78.3% of the total abundance of the benthic polychaetes. The most dominant species was Lumbrineris longifolia (9.3%), followed by Eteone longa (7.3%), Heteromastus filifomis (7.1%), Sternaspis scutata (6.1%). From the cluster analysis, the study area could be divided into three station groups. Station group AI was located in the inner bay and in the shallow coastal region, and its most dominant species was Heteromastus filiformis. At the station group AII in the mouth of bay and in some channel region, its most dominant species were Lumbrineris longifolia and Eteone longa. And at the station group B located in middle part of the bay, the most dominant specis was Sternaspis scutata. In comparison with previous studies, the benthic polychaetous community experienced great change in the view of species number, density and dominant species. The dominant species were Sternaspis scutata and Eteone longa, but their densities declined greatly. Instead of these species, Lumbrineris longifolia and Heteromastus filiformis, known as the potential organic enrichment indicator species, appeared to the new dominant species even if their low densities. These facts mean that Deugryang Bay was maintained yet as little organic enriched area compared to other bays on the coast of Korea, but needed some caution of marine environmental management.

선박엔진용 P-V 주철의 내마모성에 관한 연구

김용현,김대영,이광학 ( Yong Hyun Kim,Dae Young Kim,Kwang Hak Lee ) 한국주조공학회 1996 한국주조공학회지 Vol.16 No.3

N/A In thia study, wear resistance of P-V cast iron which is used as a material of cylinder liner for marine engine was investigated. Wear test was conducted by the wear test machine of Suzuki type(EFM-III-E model, 5000N for load, 4.0㎧ for velocity, Japan). Adhesive and scuffing wear phenomena was studied when load was changed from 60N to 400N and wear velocity was 0.25㎧ at room temperature and 250℃. In the case of dry friction at room temperature, scuffing phenomena of wear test specimens without vanadium was occurred at 400N, specimens with vanadium at the 400N was observed only adhesive wear phenomena. In the case of dry friction at 250℃, scuffing phenomena was observed at 180N for wear specimens without vanadium and 240N for wear specimens with vanadium.