ASOG 그룹기여법에 의한 공비혼합물의 공비점 추산에 관한 연구

趙泰煥 단국대학교 1987 論文集 Vol.21 No.-

Phase equilibrium data are very impotant and useful for designing separation process of operation, for example, vapor liquid equilibrium data for distillation and solid liquid equilibrium data for drystallization. However only limited experimental data are available for any particular conditions of temperature, pressure and composition that are required for particular design. The ASOG model is one of the useful methods to interpolate or extrapolate the existing mixture data, or when the suitable data or not available, to estimate the desired equilibrium data. By the ASOG method is based on the "solution of group" model, liquid phase activity coefficients were predicted in terms of the parameters associated with the pairs of scutrutal groups of the solution. The paramesers have been determined for 31 groups of the group dair parameters using vapor liquid equilibrium data. The existence and nonexistence of azeotropes were judged by the azeotropic formative condition. for prediction of the azeotropic point, I have chosen an abjective function F=ly_1-x_1/x_1 that have calculated by the Regular-Falsi method.

전통 곶감의 수출시장 소비자선호 분석

조재환,김태균,박준형 한국농업정책학회, 한국축산경영학회 2001 농업경영정책연구 Vol.28 No.3

This study analyzes the foreign consumers' preferences and the willingness to pay for the Korean traditional dried persimmons by conducting surveys to Japanese, Americans, Canadians, Europeans, Australians, and New Zealanders. The results show that the potential export demand is largest to Japanese and those to U.S. and Europe are sufficient. The results also indicate that the price has to be reduced and the quality has to be improved in order to extend the export demand for the Korean traditional dried persimmons.

농촌관광에 대한 도시민 선호분석

조재환,김태균,박시현,박준형 한국농업정책학회, 한국축산경영학회 2003 농업경영정책연구 Vol.30 No.3

This paper analyzes urban residents' preference on rural tourism using a survey data. The results show that even though urban residents are unaware of rural tourism, people who have experienced rural tourism set a high value on it. Urban residents are willing to pay about 93,600Won for rural tourism. These results indicate that there is a lot of potential demand for rural tourism. The results of this paper could be an important information to develop the rural tourism.

天然 Kaolin으로부터 Zeolite Sodium A의 合成과 이온交換特性

趙泰煥,任宏 단국대학교 1988 論文集 Vol.22 No.-

The ion exchange behavior of various inorganic exchange and other types of various inorganic exchangers and other types of crystalline silicates such as clay minerals and feldspathoida has been extensively reviewed. Because of their three-dimensional framework structure, most zeolites and feldspathoids do not undergo any appreciable dimensional change with ion exchange; clay mineral, because of their two-dimensional structure, may undergo swelling or shrinking with cation exchange. The cation exchange behavior of zeolites depends upon (i) the nature of the cation species, the cation size, both anhydrous and hydrated, and cation charge; (ii) the temperature; (iii) the concentration of the cation species in solution; (iv) the anion species associated with the cation in solution; and (v) the structural characteristics of the particular zeolite. In the present paper zeolite sodium A was prepared from calcined kaolin in sodium hydroxide solution under the reaction condition of 0.5-6N NaOH, reaction time 0.5-12hr and reaction temperature 100℃. Also, the properties and structures of the exchanged zeolite sodium A with mercury, ammonium, potassium, and lithium ions were investigated. And the ion exchange capacities of synthesized zeolite sodium A from calcined kaolin and several aluminosilicates minerals for univalent mercury cation were studied by batch method. As a result, XRD, IR spectra, SEM and DTA measurements showed that the property and structure of zeolite sodium A synthesized from kaolin is similar to that of synthetic zeolite A (ZMS 4A). The optimum conditions for synthesizing zeolite sodium A were treated with aqueous 2N sodium hydroxide solution, reaction time 10-12hr at reaction temperature 100℃. And also the order of cation exchange selectivity in the synthesized zeolite sodium A, decreasing, is: Ag^+>K^+>NH^+>Li^+. For univalent mercury ion, the ion exchange selectivities in the synthesized zeolite sodium A and several aluminosilicates were decreasing in order of synthesized zeolite sodium A, alkali-treated clinoptilolite, clinoptilolite mineral, alkali-treated bentonite, kaolin mineral and bentonite mineral.

液相의 混合性이 한정된 系의 氣液平衡의 熱力學的 健全性評價에 관한 硏究

趙泰煥 단국대학교 1985 論文集 Vol.19 No.-

The experimental vapor liquid equilibrium data were Checked for thermodynamic consistency by means of the rigorous equation propose in this paper. The enthalpy of mixing data necessary for the consistency test, which was measured at 298.15K for MEK-Water system. The result of the consistency check of vapor liquid equilibrium data for MEK-water system in literature is summarized in Table 1.

소소흡장합금을 사용한 2차전지의 충방전특성

趙泰煥 단국대학교 1993 論文集 Vol.27 No.-

The optimal conditions for nickel-hydride secondary batteries were investigated in the ZrNi hydrogen absorbing alloys. The Zr_7Ni_10 and ZrNix(1.0≤χ≤3.0) allyos, electrochemical behaviour such as charged hydrogen contents by electrolysis, discharge characteristics and changes in the partial molar enthalpy and entropy with hydrogenation were investigated in an alkaline electrolyte. It was found that the ZrNi_x (1.0≤χ≤3.0) system alloys which consist of monoclinic ZrO_2 exhibit large discharged hydrogen capacities. Furthermore, from the values of the charged hydrogen contents and the results of the x-ray investigations.

밤나무 耐寒性品種 選拔에 관한 硏究 : 耐霜性을 中心으로 Castanea crenata S. et Z.

趙台煥,洪性珏 건국대학교 1980 學術誌 Vol.24 No.2

Seasonal change in freezing resistance of buds and xylem parenchyma of 32 chestnut cultivars (Castanea crenata S. et Z.) were studied during winter of 1977 to 1978. Dehardening responses of the hardened twigs in mid-winter were examined by being exposed to high temperature of 20℃ for 3 to 15 days. Rehardening responses of the artificially or naturally dehardened twigs were tested by being exposed to short or long-term low temperatures of 7℃ or -10℃. The freezing resistance of graft unions of two cultivars was compared to that of the upper and lower parts of twigs of the seedlings at mid winter and early spring. Variation in freezing resistance among 32 chestnut cultivars at the late fall of 1977 and the early spring of 1978 were much greater than that of the early and mid-winter. The little variation in freezing resistance at mid-winter suggested that in selecting most cold hardy cultivar the speed of hardening and dehardening in cold and warm condition respectively are more important factors than the magnitude of maximum freezing resistance which could have been obtained during mid-winter or by artificial hardening, The warm temperature of 20℃ for 3 to 15 days decreased freezing resistance of the fully hardened twigs at mid-winter. The low temperature of 7 or -10℃ in short or long term increased freezing resistance of the twigs which had been dehardened either by artificial high temperature treatment or by natural conditions in early spring. The difference in freezing resistance in early spring among cultivars coincided with the difference in the sensitivity in hardening by the low temperature treatment and/or in delaying dehardening by warm temperature treatment. In the late fall and the early spring buds of all cultivars showed less freezing resistance than xylem parenchyma. In the contrast the xylem parenchyma became less hardy than the buds as the cold acelimation progreesed toward mid-winter and as the rehardening occurred on the dehardened twigs at early spring by low temperature treatment. In graft unions the upper parts of twigs showed more freezing resistance than graft parts in mid-winter. But in early spring the cold hardiness of the two parts are conversely changed each other. This phenomena frill be a good index for distinguishing midwinter from late frost damage.

Laves상 ZrV_2계 수소저장합금 전극의 Ni 치환에 따른 열역학적 안정성에 관한 연구

조태환,최원경 단국대학교 2000 論文集 Vol.35 No.-

Thermodynamic properties of laves phase ZrV_2 were studied in terms of the equilibrium hydrogen pressure. ZrV_2 alloy with high equilibrium hydrogen pressures at room temperature, which is usually difficult to charge, was substituted with Ni partialy. Partial substitution of Ni made not only the equilibrium pressure to be reduced remarkably, but also the enthalpy change depending on the formation of metal hydride to be agreed to the value in gas phase reaction and electrochemical reaction.

수소흡장합금-수소계의 전극전위와 열역학적량에 관한 연구

趙泰煥 단국대학교 1992 論文集 Vol.26 No.-

Many Metals were tried to absorb hydrogen by the electrochemistry. It is practically difficult to discharge these hydrogen absorbing metals by the electrochemistry. It is the one of reasons that a bond energy of the metal and hydrogen in hydrogen absorbing metal is very strong. It is purpose to study the hydrogen energyed storage battery with the electrode of hydrogen absorbing alloy by making use of the principle which metalhydride of the alloy based LaNi_5 is charged by the cathod polarization and discharged by the anode polarization electrochemically in KOH Solution. It is measured the electrochemical eharge-discharge capacities and anodic polarization characteristies and isothermal curve of alloy-hydrogen system and thermodynamic properties from the equilibrium electric potentio of hydrogen absorbing alloys.

광주 광역권 녹지체계 수립에 관한 기초적 연구 : GIS 이용에 따른 퍼지(Fuzzy)기법과 계층분석기법(AHP) 적용을 중심으로 Focused on the Application of Fuzzy and Analytic Hierarchy Process Methods in GIS

조영환,김태근 7개 국립대학교 환경연구 논문집 공동발행 위원회 2002 환경연구논문집 Vol.2 No.1

This fundamental study put the aim on the establishment of Gwangju Metropolitan Open Space System where the region was assigned to Metropolitan Plan Area of The 4th Comprehensive National Territorial Plan in Korea. This studied region is composed of Gwangju and Naju city and Damyang. Hwasoon country and a part of Hampyoung country where the area is 2994.91㎢. Now the GIS is well known system for characterizing spatial relationship, especially the tool for seeking proper site for decision making. But the boolean method which is usually used with map overlay technique in GIS has couple of problems in the field of spatial database management and interpretation. The failure of constructing continuous value is one of the typical problem which based on the simple set-True or False-system, while the spatial relationship has variety and complexity. So the study focused on the application of Fuzzy method with AHP technique which are relatively new to in using GIS. The merit of Fuzzy method is to keep values which existed between the two critical values and these values are useful for giving flexibility to decision making. AHP with Pairwise Comparison method can minimize the problem which occurs from adding extra value by subjectivity that is one of the important pitfalls of using GIS. The results of application of Fuzzy method with AHP showed much differences in the area of suitability of open space when compared that of boolean and achieved flexibility through the levels of suitable site for the open space area. This study was carried out with several basic factors only. The more factors should be dealt and the way of detailed interpretation of continuous data existed as luminosity in modeling should be studied. Also the distribution and giving functional value to open space system are the theme which should be deveolped for further study.