• 한국세라믹학회지
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• 제38권9호
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• pp.822-828
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• 2001

Bayer process는 보오크사이트로부터 수산화알루미늄을 추출시키는 가장 일반적인 방법으로 공정 조건에 따라 수산화알루미늄의 1차 입자경, 입도분포도 및 생산효율 등이 달라지게 된다. 본 실험에서는 앞선 석출실험 결과를 기준으로 화학제품용 및 금속제련용 수산화알루미늄 제조조건을 설정하여 석출제품의 특성을 검토하였다. 그 결과 석출율은 화학제품용 원료 제조조건이 높게 나타났으며 입자크기는 화학제품용은 42∼44${\mu}$m, 금속제련용은 74∼77${\mu}$m로 금속제련용 원료 제조조건이 입자크기가 크게 나타났다. 산용해 실험결과는 화학제품용 원료가 금속제련용 원료보다 용해성이 좋게 나타났으며, 금속제련용 제품의 마모도는 상업용 금속제련용 제품에 비해 다소 떨어지는데 이러한 이유는 타사 제품에 비해 1차입자가 작가 때문인 것으로 판단된다.

• Bulletin of the Korean Chemical Society
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• 제12권4호
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• pp.392-397
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• 1991

A stereocontrolled synthesis of (${\pm}$)-isocomene (1) via selective monoketalization of tricyclo[6.3.0.$0^{1.5}$]undeca-4,7-dione(13) was reported. Grignard reaction of bicyclic enone 10, which was prepared from 2-methyl-1,3-cyclopentadione, gave the 1,4-addition product 11. The subsequent aldol condensation product 12 was converted to mesyl derivative 13. Transformation from 13 to the desired product 19 was achieved by a series of reactions, i.e., the selective monoketalization at C-4 carbonyl group, the elimination of a mesyl group, Birch alkylation, methylation at C-6, the reduction of carbonyl group, the dehydration of alcohol 18, and hydrolysis of the ketal group.

• Applied Microscopy
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• 제50권
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• pp.15.1-15.6
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• 2020

Sample preparation including dehydration and drying of samples is the most intricate part of scanning electron microscopy. Most current sample preparation protocols use critical-point drying with liquid carbon dioxide. Very few studies have reported samples that were dried using chemical reagents. In this study, we used hexamethyldisilazane, a chemical drying reagent, to prepare plant samples. As glandular trichomes are among the most fragile and sensitive surface structures found on plants, we used Millingtonia hortensis leaf samples as our study materials because they contain abundant glandular trichomes. The results obtained using this new method are identical to those produced via critical-point drying.

• Bulletin of the Korean Chemical Society
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• 제8권4호
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• pp.296-298
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• 1987

Irradiation of a solution of chloranil and cycloheptatriene, or 1,3-cyclohexadiene, in dichloromethane yielded unexpected photorearrangement products as the major product, while chloranil with cyclohexene gave the photorearrangement product as well as 1 : 1 adduct.

• Bulletin of the Korean Chemical Society
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• 제23권9호
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• pp.1208-1254
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• 2002

Photoreaction of N-(o-halophenyl)acetamide in basic acetonitrile produces an intramolecular substituted product, 2-methylbenzoxazole in addition to reduced product, acetanilide, whereas photoreaction of N-(o-halobenzyl) acetamide affords a reduced product, N-benzylacetamide only. On the basis of preparative reaction, kinetics, and UV/vis absorption behavior, an electrophilic aromatic substitution of aryl halide with oxygen of its amide bond are proposed.

• Bulletin of the Korean Chemical Society
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• 제22권11호
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• pp.1202-1206
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• 2001

Irradiation of 1-(o-hydroxyphenyl)-2-pentamethyldisilanylethyne 1 in a concentrated benzene solution has provided photodimer product 7 along with other reported photoproducts. Irradiation of 1 in methanol yields 1-(o-hydroxyphenyl)-2-trimethylsilylethyne 2 and its reduction product 13, via silacyclopropene intermediate 10, and the reduction product 8 and two methanol addition products, 11 and 12, via o-hydroxyphenylethyne. Photolysis of 1 with acetone in deaerated methylene chloride affords site specific and regioselective 1 : 1 adduct 16 via silacyclopropene intermediate 10.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.738-741
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• 2001

We carried out aminolyses of various rigid polyurethane foams (PUFs) using diethylene triamine and studied application of the aminolysis products as hardners of epoxy resins. Diglycidyl ether of bisphenol A was used for the study on the curing behavior of epoxy resin with the aminolysis product employing differential scanning calorimeter. Curing reaction of the epoxy resin is generally known to be autocatalytic second order reaction. We found that the curing reaction of the epoxy resin with the aminolysis product of rigid PUF did not show autocatalytic characteristics but followed the n-th order kinetics. The activation energy of the curing reaction of the epoxy resin with the aminolysis product of rigid PUF made from sugar based polyol was slightly lower than that of the epoxy resin with aminolysis product of rigid with made from amine based polyol.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2523-2526
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• 2007

• Bulletin of the Korean Chemical Society
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• 제27권2호
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• pp.312-314
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• 2006

• 한국응용곤충학회:학술대회논문집
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• 한국응용곤충학회 2004년도 춘계 학술발표회
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• pp.77-77
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• 2004