• 설비공학논문집
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• 제27권5호
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• pp.269-276
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• 2015

Single-effect $CH_3OH-LiI-ZnBr_2$ and $C_2H_5OH-LiI$ absorption heat pumps are simulated to evaluate feasibility as heating device. These systems are predicted to give higher heating COPs in wide operating ranges compared to conventional systems. Among the two systems, the $C_2H_5OH-LiI$ system is found to be more advantageous for operating in extremely cold weather due to the large solubility of Lil in $C_2H_5OH$.

• 센서학회지
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• 제20권1호
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• pp.1-7
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• 2011

Undoped and Sb-doped $SnO_2$ nanofibers were prepared by electrospinning and their responses to $H_2$, CO, $CH_4$, $C_3H_8$, and $C_2H_5OH$ were measured. In the undoped $SnO_2$ nanofibers, the gas response ($R_a/R_g$, $R_a$: resistance in air, $R_g$: resistance in gas) to 100 ppm $C_2H_5OH$ was very high(33.9), while that to the other gases ranged from 1.6 to 2.2. By doping with 2.65 wt% Sb, the response to 100 ppm $C_2H_5OH$ was decreased to 4.5, whereas the response to $H_2$ was increased to 3.0. This demonstrates the possibility of detecting a high $H_2$ concentration with minimum interference from $C_2H_5OH$ and the potential to control the gas selectivity by Sb doping.

• 대한화학회지
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• 제56권4호
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• pp.440-447
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• 2012

Heteroleptic complexes of zirconium (IV) derived from bulky Schiff base ligands containing a sulphur atom and oximes of heterocyclic ${\beta}$-diketones of the general formula ZrLL' (where $LH_2=RCNH(C_6H_4)SC:C(OH)N(C_6H_5)N:CCH_3$, $R=-C_6H_5$, $-C_6H_4Cl(p)$ and $L^{\prime}H_2=R^{\prime}C:(NOH)C:C(OH)N(C_6H_5)N:CCH_3$, $R^{\prime}=-CH_2CH_3$, $-C_6H_5$, $-C_6H_4Cl(p)$ were prepared by the reactions of zirconium tetrachloride with disodium salts of Schiff bases ($L\;Na_2$) and oximes of heterocyclic ${\beta}$-diketones ($L^{\prime}\;Na_2$) in 1:1:1 molar ratio in dry refluxing THF. The structures of these monomeric zirconium (IV) complexes were elucidated with the help of elemental analysis, molecular weight measurements, spectroscopic (IR, NMR and mass) studies. A distorted trigonal bipyramidal geometry may be suggested for these heteroleptic zirconium (IV) complexes. The ligands (bulky Schiff base ligands containing a sulphur atom and oximes of heterocyclic ${\beta}$-diketones) and their heteroleptic complexes of zirconium (IV) were screened against A. flavus, P. aeruginesa and E. coli.

• 대한화학회지
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• 제30권3호
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• pp.320-326
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• 1986

몇몇 백금(II) 착물과 팔라듐(II) 착물에 잠재적인 항종양 활성이 있다고 보고 되었다. 그러나 백금(II) 착물들은 항종양제로서 독성이 있으므로 본 연구에서는 아데닌, 우라실, 시토신 및 말로네이트 배위자를 포함한 팔라듐(II) 착물에 관심을 가지고 합성하였다. 팔라듐(II)와 배위자와의 반응은 수용액 상태에서 연구하였으며, $[Pd(en)(C_5H_5N_5)_2](NO_3)_2,\;[Pd(en)(C_4H_3N_2O_2)Cl],\;[Pd(en)(C_4H_5N_3O)_2](NO_3)_2{\cdot}(C_4H_5N_3O)$ 및 $[Pd(en)(C_3H_2O_4)]$ 분자식의 형태로 분리하였다. 이들 화합물들은 원소분석 및 질량분석 및 질량분석으로부터 존재 원소의 함량과 분자식을 추정하였으며, 적외선 스펙트럼과 전자 스펙트럼으로부터 금속과 배위자의 결합 및 전자이동에 대해서 조사하였다.

• 한국세라믹학회지
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• 제24권5호
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• pp.500-506
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• 1987

In order to synthesize monodispersed spherical silica fine particles, we investigated the reaction of hydrolysis of 0.05∼4.0 mole Si(OC2H5)4-0.01∼7.60mole NH3 -0.24∼38.40 mole H2O-2.62∼16.88mole C2H5OH systems. The range of the composition of solution which spherical silica particles were formed was enlarged according to an increase in concentration of Si(OC2H5)4. Larger particles were obtained at higher molar ratios of Si(OC2H5)4/C2H5OH, NH3/H2O and H2O/Si(OC2H5)4 and at a lower reaction temperature.

• 대한환경공학회지
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• 제22권5호
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• pp.879-886
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• 2000

본 연구에서는 NaOH로 첨착(함침)시킨 활성탄의 $H_2S$ 흡착특성을 고찰하였다. 첨착시약으로 사용된 NaOH용액의 농도는 1~8 N이며, 활성탄의 입자크기는 $8{\times}30$ mesh가 적용되었다. 실험결과, 첨착율이 0.87~5.8% 범위내에서 증가될수록 BET 표면적은 $1050m^2/g$에서 $783m^2/g$로 감소되며, 표면산도는 0.541 meq/g-AC에서 0 meq/g-AC으로 감소하고, pH는 9.56에서 10.86으로 증가하는 것으로 밝혀졌다. 또한 NaOH로 첨착시킨 활성탄의 $H_2S$ 평형흡착능은 흡착온도와 $H_2S$ 가스농도에 비례함을 보였으며, 흡착온도가 $45^{\circ}C$일 때 17.87~30.34 mg/g-AC 범위의 $H_2S$ 평형흡착능을 보임으로써 비첨착활성탄에 비해 2~3배 높은 수준을 나타냄을 알 수 있었다.

• 한국세라믹학회지
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• 제26권4호
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• pp.493-498
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• 1989

High purity, submicron BaTiO3 powder was prepared by a hydrothermal technique using Ba(OH)2.8H2O, TiCl4 and NH4OH as starting raw materials. The submicron BaTiO3 powder was synthesized at 130~23$0^{\circ}C$ for 2.5h to yield highly crystalline particles with a narrow particle distribution. The mole ratio of Ba(OH)2.8H2O/TiO(OH)2 was 1.5. It is possible to obtain BaTiO3 with Ba : Ti=1.00$\pm$0/01. The samples densified well at 13$25^{\circ}C$, showing a uniform and fine grain structure. The grain size ranged between 0.3 and 0.5${\mu}{\textrm}{m}$. The products obtained by hydrothermal treatment at various temperatures from 130 to 23$0^{\circ}C$ were characterized by XRD, DTA, BET and SEM etc.

• KSBB Journal
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• 제5권1호
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• pp.81-85
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• 1990

부틸알코올과 증류수를 유기용매로 사용하여 볏짚을 전처리하고 리그닌을 추출하였으며, 추출된 리그닌으로부터 적절한 산화촉매(CuO, Cu(OH)$_2$, CuSO$_4$.5H_2$O)하에서 바닐린 생성 실험을 하였다. 볏짚으로부터 리그닌 분리추출의 최적조건은 ptoluenesulfonic acid 2.5g을 촉매로하여 부틸알코올과 물을 1:1로 혼합한 용매 500ml에 볏짚 25g을 넣고 12$0^{\circ}C$하에서 반응시켰을 경우이었다. 한편 리그닌으로부터의 바닐린 수율은 반응온도의 증가에 따라 전형적으로 증가하였고, 촉매 종류에 따라 Cu(OH)<$_2$ CuO$_4\cdot \;5H_2$O를 사용하고 18$0^{\circ}C$에서 2시간 반응시켰을 때 바닐린의 최대 수율은 9%이었다.

• 대한환경공학회지
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• 제32권11호
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• pp.1011-1016
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• 2010

본 연구에서는 NaOH, KOH, $(CH_2CH_2OH)_2NH$ 등의 염기성용액으로 첨착(함침)시킨 활성탄의 물리.화학적 특성을 분석하고 H2S 흡착특성을 고찰하였다. 실험변수로는 흡착온도($25{\sim}45^{\circ}C$), 흡착질인 황화수소 가스농도(18.23 mg/L) 등이 적용되었다. 첨착시약으로 사용된 NaOH, KOH 용액의 농도는 1~5 M, $(CH_2CH_2OH)_2NH$ 용액의 농도는 0.1~1 M 범위내에서 적용되었다. 실험결과, 첨착액의 농도가 증가할수록 KOH로 함침시킨 활성탄의 BET 표면적은 $1,050\;m^2/g$에서 $750\;m^2/g$로 감소하였고, NaOH로 함침시킨 활성탄의 표면산도는 0.541 meq/g-AC에서 0 meq/g-AC으로 감소한 반면, pH는 9.54에서 10.94로 증가하는 것으로 밝혀졌다. 또한 첨착활성탄의 $H_2S$ 평형흡착능은 디에탄올아민으로 첨착시킨 경우에 가장 높았으며, 평형흡착능은 흡착온도에 비례함을 보였다. 흡착온도가 $45^{\circ}C$일 때 비첨착활성탄에 비해 2.0~3.3배 높은 수준의 H2S 평형흡착능을 보여 주었다.

• 환경위생공학
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• 제15권1호
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• pp.95-101
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• 2000

This study was investigated to the reaction of alumina sintering with alkaline. The soluble $NaAlO_2$ was made after the commercial ${\alpha}-Al_2O_3$ was calcinated with NaOH. The reaction of alumina was carried out to be based on the effects of calcination temperature, time, and the mixing ratio of ${\alpha}-Al_2O_3/NaOH$. The alumina was calcined over $500^{\circ}C$ with NaOH powder after it was sieved with 170/270 mesh. The calcined alumina with NaOH powder was dissolved into $25^{\circ}C$ distilled water and filtrated, and HCI was added to adapt pH 6.5~7.5. The residue was separated with vacuum pump for filtration after it was adapted to proper pH, and aluminum compound was precipitated with $Al(OH)_3$. The investigation was carried out with the variables; the calcination temperature($500-900^{\circ}C$), the calcination time (30~90 min), and the concentration of HCI when leaching(0.5~3.0N) respectively. In this investigation, the main product of ${\alpha}-Al_2O_3$ and NaOH was $NaAlO_2$ and the maximum conversion ratio was 91.4% under the optimum conditions as followed ; the ratio of NaOH/${\alpha}-Al_2O_3$ was 1.5 and the calcination conditions were $800^{\circ}C$ and 90 min.