• Bulletin of the Korean Chemical Society
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• 제23권6호
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• pp.803-807
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• 2002

The conversion of dimethyl ether(DME) has been carried out over $\gamma-alumina$, silica-alumina, and modified $\gamma-aluminal$ catalysts. Especially, the water effect has been investigated on purpose to develop a suitable catalyst for one-step synthesis of DME from $CO_2$ hydrgenation, The $\gamma-Al_2O_3$ modified with 1 wt% silica is more active and less deactivated by water than unmodified one. $CO_2has$ no effect on catalytic dehydration of methanol to DME.

• Bulletin of the Korean Chemical Society
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• 제8권6호
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• pp.466-470
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• 1987

Di-2-pyridyl thionocarbonate, prepared from thiophosgene and 2-hydroxypyridine in the presence of triethylamine in dichloromethane, was found to be very effective for dehydration, dehydrosulfurization, and thiocarbonyl transfer reactions. Di-2-pyridyl thionocarbonate was successfully for the esterification of carboxylic acids, dehydration of aldoximes into nitriles, preparation of isothiocyanates from amines, and preparation of cyclic thionocarbonates from 1,2- and 1,3-diols.

• Journal of Biosystems Engineering
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• 제34권3호
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• pp.155-160
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• 2009

This study was attempted to quality characteristics of ginseng powder using molecular press dehydration(MD) method. Ginseng powder was dried using maltodextrin as dehydrating agents, and the quality of the ginseng powder was compared with that of freeze-drying and hot air-drying samples in terms of colors, moisture contents and grain size. The colors of ginseng powder using MD-drying and freeze-drying was better than hot air-dried ginseng powder. The moisture contents of ginseng powder using MD-drying was 9.49%, while freeze-drying was 4.14% and hot air-drying 11.71% after 72ball mill times. The grain size of ginseng powder using MD-drying and freeze-drying was better than hot air-drying ginseng powder. These results suggest that drying of ginseng powder using molecular press dehydration method is very efficient, because minimal cell destruction may be achieved.

• Bulletin of the Korean Chemical Society
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• 제32권4호
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• pp.1327-1330
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• 2011

Dehydration of 1-phenylethanol to produce styrene has been studied in liquid phase with three solid acid catalysts such as H-ZSM-5, H-Y and Amberlyst-15. Amberlyst-15 shows the highest conversion and styrene yield, suggesting the applicability of a resin catalyst in the dehydration. The good performance of the Amberlyst-15 may be due to high acid concentration and ready diffusion of reactants and products. A possible reaction scheme (such as the formation of styrene from diphenylethylether) has also been suggested.

• 한국세라믹학회지
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• 제18권1호
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• pp.35-40
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• 1981

The kinetics of the dehydration of Ha-dong kaolin was studied isothermally at various temperatures. Dehydration rate was measured by thermogravimetry method in the temperature range of 440~50$0^{\circ}C$ and the particle size range of 170~325mesh. The general equation f($\alpha$)=kt, where $\alpha$ is the fraction reacted in the time and the function f($\alpha$) depends on the reaction mechanism, was applied to this reaction. The function, f($\alpha$) was obtained by application of reduced-time plot and plot of lnln (1-$\alpha$) vs. ln (time), and expressed as (1-$\alpha$) ln (1-$\alpha$)+$\alpha$=kt. The dehydration followed the diffusion-controlled reaction model and gave activation energy of 30Kcal/mole.

• 한국연초학회지
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• 제5권2호
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• pp.9-15
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• 1983

The effect of leaf dehydration process and air flow capacity of bulk curing on physical properties and composition of cured leaves was studied, respectively, during flue- curing. Cured leaves from excessive moisture during yellowing stage and those from rapid dehydration Process inevitably during later stages, tend towards lower equilibrium moisture contents, higher shatter index, hither protein nitrogen, and leaf scalding or deterioration of Beaves with redish cast. Early dehydration at the yellowing stage re suited in increasing of p Bamitic, stearic, linoleic, and linolenic acid contents, but showed reduction of brightness difference between upper and lower surface of the cured leaves, Leaf surface lipid decreased with the progress of curing stages, more conspicuously during later stage. Lowering air flow capacity of fan by 50oye during stem drying stage resulted in increasing of leaf surface lipid and 25oye decreasing of electric power consumption , but curing period and kerosene consumption were not affected.

• 연구논문집
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• 통권26호
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• pp.33-42
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• 1996

The transmission system of a washing machine which is called by the clutch is one of the most important components to preserve the performance. The clutch housing has a role to guard and mount the transmission system on the frame of the machine. The load which is applied on the clutch housing depends on the operating conditions. Nowadays the dehydration speed is higher and higher in order to improve the efficiency. In this study, the strains on the predicted weak positions were measured using the strain gage and its measuring equipment. The relationships between the dehydration speeds and the maximum principal strains were obtained. Finite element analysis is executed to acquire the effect of the dehydration speed on the stress of the clutch housing. The distributions of the equivalent stress and the maximum stresses under the various speeds, the various loading directions and the various thickness of the clutch housing were obtained.

• 대한화학회지
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• 제20권6호
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• pp.448-452
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• 1976

간단한 통계역학적 방법을 사용 수화된 이온의 완화시칸, 탈수화시의 활성화, 에너지, 탈수화율 등을 계산하였다. 구상한 model에 의하면 수화된 물과 탈수화된 물 간의 평형상수, 물-이온간 에너지 항, 각종 species 간의 혼합 factor들이 들어있다. 이론과 실험은 잘 맞는 겨로가를 보이고 있다. 또한 이온이 탈수화식의 압력의 영향도 아울러 논의하였다.

• Korean Journal of Chemical Engineering
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• 제35권12호
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• pp.2348-2354
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• 2018

We designed a conceptual model of the 2.3-BDO dehydration process using a hydroxyapatite-alumina catalyst and estimated its economic feasibility to predict the appropriate range of the purchase price of 2,3-BDO on commercial scale. The conceptual design and economic analysis can offer valuable information for the industrial application of 2,3-BDO because the most relevant studies have limitation in laboratory scale. Furthermore, the adequate range of 2,3-BDO price, in which the process has profitability, was investigated with the current market prices of 1,3-BD. The investigated price in terms of 2,3-BDO dehydration can pertain to estimation of the economic feasibility in 2,3-BDO production process.

• BMB Reports
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• 제51권12호
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• pp.611-612
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• 2018

$C1q/TNF-{\alpha}-Related$ Protein 1 (CTRP1) has recently been shown to act as a blood pressure regulator, as it induces vasoconstriction. In the aorta, CTRP1 facilitates recruitment of angiotensin II receptor 1 (AT1R) to plasma membrane, through activation of the AKT/AS160 signaling pathway. This leads to activation of the Ras homolog gene family (Rho)/Rho kinase (ROCK) signaling pathway, resulting in vasoconstriction. Accordingly, mice overexpressing Ctrp1 have hypertensive phenotype. Patients with hypertension also display higher circulating CTRP1 levels, compared to healthy individuals, indicating that excessive CTRP1 may affect development of hypertension. Conversely, CTRP1 is regarded as an 'innate blood pressure modulator' because CTRP1 increases blood pressure under dehydration to prevent hypotension. Mice lacking Ctrp1 fail to maintain normotension under dehydration conditions, resulting in hypotension, suggesting that CTRP1 is an essential protein for maintaining blood pressure homeostasis. In conclusion, CTRP1 is a novel, anti-hypotensive vasoconstrictor that increases blood pressure during dehydration-induced hypotension.