• 한국작물학회지
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• 제5권1호
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• pp.45-49
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• 1969

수도재배시기이동시의 품종의 적응성 또는 외국품종도입시 그 적부판단의 기준이 되는 일장 및 온도효과의 본질과 한국품종들의 감응도를 분석비교하였다. 시험결과 공시품종들은 전부 일장에 대하여 비교적 둔감하고 어느 처리일장하에서나 출수하여 한계일장이 없었으나 만생품종은 조생종에 비하여 감광성이 예민하고 기본영양생장기간이 짧었고 조생품종은 기본영양생장성이 컸으며 최적일장은 전품종 10시간전후였다. 또한 온도도 일장과 같이 생육기간에 대하여 영향이 큰 것 같고 저온은 일장의 장단, 품종의 조만에 관계없이 출수를 지연시키고 고온은 기본영양생장기간을 단축시키고 일장감응기에는 별로 영향이 없었다.

• 설비공학논문집
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• 제14권8호
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• pp.634-640
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• 2002

The purpose of this study is to investigate the propriety of TMA clathrate as a cold storage medium. Particularly, this is to examine the extent of subcooling improvement when the additives is added to the TMA clathrate, because water used for cold storage ma terial has low phase change temperature and subcooling. This study has been analyzed and compared pure water with TMA 30 wt% clathrate how phase change temperature, subcooling and specific heat in the various concentrations are changed. This results prove low phase change temperature and subcooling control effect when the ethanol is added to the TMA 30 wt% clathrate than the TMA 30 wt% clathrate. In addition, it results low specific heat when there is added to the TMA 30 wt% clathrate over 0.5 wt% ethanol in the cold heat source temperature under $-7^{\circ}C$. The other side, it results high specific heat when the ethanol is added in it at the cold heat source temperature under $-5^{\circ}C$. Therefore, it is found that the additive must be controlled by available solution limit and study for new additive must be lasted to know its effect.

• 대한금속재료학회지
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• 제46권11호
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• pp.762-769
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• 2008

Hydrogenated amorphous silicon(a-Si : H) layers, 120 nm and 50 nm in thickness, were deposited on 200 $nm-SiO_2$/single-Si substrates by inductively coupled plasma chemical vapor deposition(ICP-CVD). Subsequently, 30 nm-Ni layers were deposited by E-beam evaporation. Finally, 30 nm-Ni/120 nm a-Si : H/200 $nm-SiO_2$/single-Si and 30 nm-Ni/50 nm a-Si:H/200 $nm-SiO_2$/single-Si were prepared. The prepared samples were annealed by rapid thermal annealing(RTA) from $200^{\circ}C$ to $500^{\circ}C$ in $50^{\circ}C$ increments for 30 minute. A four-point tester, high resolution X-ray diffraction(HRXRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and scanning probe microscopy(SPM) were used to examine the sheet resistance, phase transformation, in-plane microstructure, cross-sectional microstructure, and surface roughness, respectively. The nickel silicide on the 120 nm a-Si:H substrate showed high sheet resistance($470{\Omega}/{\Box}$) at T(temperature) < $450^{\circ}C$ and low sheet resistance ($70{\Omega}/{\Box}$) at T > $450^{\circ}C$. The high and low resistive regions contained ${\zeta}-Ni_2Si$ and NiSi, respectively. In case of microstructure showed mixed phase of nickel silicide and a-Si:H on the residual a-Si:H layer at T < $450^{\circ}C$ but no mixed phase and a residual a-Si:H layer at T > $450^{\circ}C$. The surface roughness matched the phase transformation according to the silicidation temperature. The nickel silicide on the 50 nm a-Si:H substrate had high sheet resistance(${\sim}1k{\Omega}/{\Box}$) at T < $400^{\circ}C$ and low sheet resistance ($100{\Omega}/{\Box}$) at T > $400^{\circ}C$. This was attributed to the formation of ${\delta}-Ni_2Si$ at T > $400^{\circ}C$ regardless of the siliciation temperature. An examination of the microstructure showed a region of nickel silicide at T < $400^{\circ}C$ that consisted of a mixed phase of nickel silicide and a-Si:H without a residual a-Si:H layer. The region at T > $400^{\circ}C$ showed crystalline nickel silicide without a mixed phase. The surface roughness remained constant regardless of the silicidation temperature. Our results suggest that a 50 nm a-Si:H nickel silicide layer is advantageous of the active layer of a thin film transistor(TFT) when applying a nano-thick layer with a constant sheet resistance, surface roughness, and ${\delta}-Ni_2Si$ temperatures > $400^{\circ}C$.

• 열처리공학회지
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• 제26권3호
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• pp.105-112
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• 2013

The microstructural changes of Fe-20Mn-12Cr-1Cu alloy have been studied during high temperature gas nitriding (HTGN) at the range of $1000^{\circ}C{\sim}1150^{\circ}C$ in an atmosphere of nitrogen gas. The mixed microstructure of austenite and ${\varepsilon}$-martensite of as-received alloy was changed to austenite single phase after HTGN treatment at the nitrogen-permeated surface layer, however the interior region that was not affected nitrogen permeation remained the structure of austenite and ${\varepsilon}$-martensite. With raising the HTGN treatment temperature, the concentration and permeation depth of nitrogen, which is known as the austenite stabilizing element, were increased. Accordingly, the depth of austenite single phase region was increased. The outmost surface of HTGN treated alloy at $1000^{\circ}C$ appeared Cr nitride. And this was in good agreement with the thermodynamically calculated phase diagram. The grain growth was delayed after HTGN treatment temperature ranges of $1000^{\circ}C{\sim}1100^{\circ}C$ due to the grain boundary precipitates. For the HTGN treatment temperature of $1150^{\circ}C$, the fine grain region was shown at the near surface due to the grain boundary precipitates, however, owing to the depletion of grain boundary precipitates, coarse grain was appeared at the depth far from the surface. This depletion may come from the strong affinity between nitrogen and substitutional element of Al and Ti leading the diffusion of these elements from interior to surface. Because of the nitrogen dissolution at the nitrogen-permeated surface layer by HTGN treatment, the surface hardness was increased above 150 Hv compared to the interior region that was consisted with the mixed microstructure of austenite and ${\varepsilon}$-martensite.

• 한국전기전자재료학회논문지
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• 제24권7호
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• pp.525-531
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• 2011

In this paper, experimental analyses have been performed to compare the electrical characteristics of n channel LT(low temperature) and HT(high temperature) poly-Si TFTs(polycrystalline silicon thin film transistors) on quartz substrate according to activated step annealing. The size of the particles step annealed at low temperature are bigger than high temperature poly-Si TFTs and measurements show that the electric characteristics those are transconductance, threshold voltage, electric effective mobility, on and off current of step annealed at LT poly-Si TFTs are high more than HT poly-Si TFT's. Especially we can estimated the defect in the activated grade poly crystalline silicon and the grain boundary of LT poly-Si TFT have more high than HT poly-Si TFT's due to high off electric current. Even though the size of particles of step annealed at low temperature, the electrical characteristics of LT poly-Si TFTs were investigated deterioration phenomena that is decrease on/off current ratio depend on high off current due to defects in active silicon layer.

• 한국수소및신에너지학회논문집
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• 제17권4호
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• pp.395-402
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• 2006

Iodine-sulfur(IS) hydrogenation production process consists of three sections, which are so called a Bunsen reaction section, a HI decomposition section and a $H_2SO_4$ decomposition section as a closed cycle. For highly efficient operation of a Bunsen reaction section, we investigated the phase separation characteristics of $H_2SO_4-HI-H_2O-I_2$ system into two liquid phases($H_2SO_4$-rich phase and $HI_x$-rich phase) in the high temperature ranges, mainly from 353 to 393 K, and in the $H_2SO_4/HI/H_2O/I_2$ molar ratio of $1/2/14{\sim}30/0.3{\sim}13.50$. The desired results for the minimization of impurities in each phase were obtained in conditions with the higher temperature and the higher $I_2$ molar composition. On the basis of the distribution of $H_2O$ to each phase, it is appeared that the affinity between $HI_x$ and $H_2O$ was more superior to that between $H_2SO_4$ and $H_2O$.

• 한국세라믹학회지
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• 제36권6호
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• pp.583-589
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• 1999

In the fabrication of ceramic chip couples for high frequency application such as the mobile communication equipment the formation of electrode lines and Ag diffusion were investigated with heat treatment conditions for removing organic binders. The deformation and densification of the electrode line greatly depended on the binder burnout process due to the overlapped temperature zone near 400$^{\circ}C$ of the binder dissociation and the solid phase sintering of the silver electrode. Ag ions were diffused into the glass ceramic substrate. The Ag diffusion was led by the glassy phase containing Pb ions rather than by the crystalline phase containing Ca ions. The fact suggests that the Ag diffusion could be controlled by managing the composition of the glass ceramic substrate.

• 국제초고층학회논문집
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• 제6권2호
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• pp.197-205
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• 2017

The conflict between indoor environmental quality and energy consumption has become an unneglectable problem for highrise office buildings, where occupants' productivity is highly affected by their working environment. An effective Façade, therefore, should play the role of an active building skin by adapting to the ever-changing external environment and internal requirements. This paper explores the energy-saving and indoor environment-improving potential of a phase-change material (PCM) integrated Façade. Building performance simulations, combined with parametric study and sensitivity analysis, are adopted in this research. The result quantifies the potential of a PCM-integrated Façade with different configurations and PCM properties, taking as an example a south-oriented typical office room in Shanghai. It is found that a melting temperature of around $22^{\circ}C$ for the PCM layer is optimal. Compared to a conventional Façade, a PCM-integrated Façade effectively reduces total energy use, peak heating/cooling load, and operative temperature fluctuation during the periods of May-July and November-December.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1210-1212
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• 2005

High temperature superconducting(HTS) power cable system consists of HTS cable, termination and cryogenic system. And the HTS cable consists of the former, HTS phase conductor, electric insulation, HTS shield and cryostat. Taking the advantage of HTS shield, the cold dielectric has been adopted. The phase conductor and the shield have been designed to minimize the AC loss below 1W/m/phase. The former has been designed to transport the fault current of 25kA, at fault condition. This paper describes the design process of 22.9kV HTS cable considering AC losses at normal state and the stability at fault condition.

• 공업화학
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• 제5권2호
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• pp.274-284
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• 1994

비이온성 계면활성제 $C_{12}E_5$, 비극성 오일 n-hexadecane, 물을 포함한 계에 oleyl alcohol 혹은 oleic acid 같은 극성 성분을 첨가했을 때의 Phase Inversion Temperature (PIT)를 측정한 결과, 첨가한 극성성분은 친유성 첨가제와 같이 PIT를 급격히 감소시킴을 알 수 있었다. PIT에서의 microemulsion phase의 surfactant film 조성 계산에 의하면 surfactant film에서의 극성 성분/계면활성제 비율이 증가할수록 PIT는 감소하였다. 또한 극성 성분의 첨가는 PIT에서의 microemulsion phase의 부피와 오일, 물의 solubilization parameter에도 큰 영향이 있었다. PIT의 감소에 따라, 예를 들면 극성 성분의 첨가량을 증가시킴에 따라, microemulsion phase의 부피는 급격히 증가하였으며 아울러 오일, 물 모두의 microemulsion phase에 대한 solubilization parameter가 급격히 증가하였다. 본 연구 결과를 비교할 수 있는 세척력 실험결과는 현재 없지만 PIT의 측정은 middle-phase microemulsion phase가 형성되는, 즉 많은 양의 오일을 제거할 수 있는 조건을 예측할 수 있는 유용한 방법임을 알 수 있었다.