學事管理의 電算化에 關한 硏究 : 授業및 學籍管理를 中心으로

李學沂,金三卯,朴民號 경북대학교 과학교육연구소 1978 科學敎育硏究誌 Vol.2 No.-

授業및 學籍處理 業務의 電算化를 위한 제 問題를 檢討 分析하고 電算處理를 위한 細部 過程및 이를 履行하는 프로그램을 作成한 후 標本業務 處理를 하여 滿足할만한 結果를 얻을 수 있었다. The problems related to computerizing the management of the affairs concerning university classes and processing students records were examined, and computer programs were made according to the detailed steps. Acceptable results were got out of the simulated execution of those programs.

低溫光反應 裝置의 製作과 이를 利用한 테트라페닐디아조시클로펜타디엔의 低溫光反應

李學沂,金鴻洛,李忠熙 慶北大學校 1987 論文集 Vol.44 No.-

The apparatus for low temperature photoreaction is very useful one for detecting reactive intermediates such as carbene, benzyne etc. So, the major portion of this work dealt with the construction of apparatus for low temperature photoreaction. And tetraphenyldianzocyclopentadiene was synthesized as a precursor by reaction of benzil with 1, 3-diphenylacetone and p-toluenesulfonylhydrazide. Using this apparatus constructed for low temperature photoreaction, tetraphenyldiazocyclopentadiene was irrdiated by UV (λ>280nm) at 10K, 7 exp (-6)mbar. Irradiation of tetraphenyldiazocyclopentadiene through quartz window at 10K gave three new strong IR peaks; 2,110 cm^-1, 1,675cm^-1, and 765cm^-1. Comparison with the results of matrix isolated study of diazocyclopentadiene, it was believed photoproducts to be tetraphenylcyclopentadienylidene (765cm^-1) as carbene and tetraphenylcyclopropenylallene (2,110cm^-1, 1,675cm^-1) formed by intramolecular rearrangement of the carbene.

Vinyl acetate의 低溫radical重合

李學沂,金祐植 慶北大學校 1975 論文集 Vol.20 No.-

Vinyl acetate was polymerized to low conversion at 0℃ with tri-n-butylborane-oxygen as initiators. The poly(vinyl acetate) prepared was saponified to poly (vinyl alcohol), and the poly(vinyl alcohol) was acetylated. The reacetylated poly(vinyl acetate) was characterized by viscosity and molecular weight. From the data, the polymer was known to be a linear molecule. The fact suggests that the reaction of transfer to main chain does not occur at 0℃ and linear PVAc can be prepared by polymerization at 0℃ without carrying out reacetylation.

하악 과두에서 발생한 골연골종의 수술적 치료: 증례 보고 및 문헌 고찰

이학기,김규태,김민수,김현준,윤태승,임호경,장현석,이의석 대한구강악안면병리학회 2016 대한구강악안면병리학회지 Vol.40 No.3

Osteochondroma is one of the most common benign tumors of the bone. Although osteochondroma is rarely seen in the facial region, it was reported that the cases occured in the mandibular region, especially around the condyle. Patients complain about malocclusion, temporomandibular disorders and facial asymmetry. The treatments of these cases include total condylectomy or local resection of the lesion. A 48-year-old man visited our hospital. His chief complaints were pain in the left temporomandibular joint (TMJ) and deviation of mandible during mouth opening. Panoramic radiograph showed an enlarged left condyle. A bony proliferation with benign sign was also observed in the computed tomography. Surgical treatment was done by removing the bony mass. Histologically, biopsy result was an osteochondroma. After surgery, there was reduced pain and normal mouth opening. Deviation of the mandible was also observed. We report a case of osteochondroma on the mandibular condyle and a review of literature about the surgical treatment.

NMR에 依한 trans-2-Butene-dial dioxime의 立體構造에 關한 硏究

李學沂,沈相喆,嚴在國 慶北大學校 1976 論文集 Vol.21 No.-

The structure of trans-2-butene-dial dioxime was investigated by means of NMR spectroscopy. Its conformer was found to have the planar structure conjugated with the double-bonds from the vicinal spin-spin coupling constants. The configurations of two oxime group were investigated from the solvent effects and assigned as the perfect symmetric structures, mixture of "syn-syn" and "anti-anti" forms.

1, 4-디케톤 置換體의 디아조 化合物 合成

李學沂,金鴻洛,李信雄 慶北大學校 1987 論文集 Vol.44 No.-

There are numerous ways in the generation of carbene intermediates. The decomposition of diazo compounds is a quite general reaction for the carbene formation. However, the synthesis of the required diazo compounds has sometimes a limitation because the diazo compounds are unstable. The cis-form of hydrazone of substituted unsaturated 1,4-diketone usually gives substituted pyridazine which is not easily decomposed to produce carbene by heat or light. In this study, trans-1,2-dibenzoylethlene was prepared from maleic anhydride via three steps. Tosylhdrazones were obtained from the reaction of tosylhydrazine with t-1,2-dibenzoylethylene in THF. The tosylhydrazone of the ketone was reacted with base catalyst to give diazo compound, 1,2-bis (diazobenzoyl) ethylene in DMF with loss p-tolunesulfinate.

Imidazole-Azo유도체의 Spectra

李學沂,林龍進 慶北大學校 1976 論文集 Vol.21 No.-

In order to investigate the possibility as a dyestuff, the spectra of imidazole azo derivatives were studied in comparison with phenyl azo ones. The λmax of imidazole azo derivatives was 17-23 nm longer wave region than that of phenyl derivatives and it means that imidazole azo dyes have more bathochromic effect than phenly azo dyes. The spectra of substituted 2'-oxyphenyl azo imidazole showed isosbestic points in accordance with the variation of pH range in the methanol-water solution. It will be due to the protonation and deprotonation of dyes in acid-alkali solution. The authors discussed these imidazole azo dervatives on the possibility as a disperse azo dye.

Hydrazine 合成에 있어서 Ca(OH)_2의 作用에 關해서

李學沂 慶北大學校 1958 論文集 Vol.2 No.-

It is important to study hydrazine because of the development of new uses for its derivatives. Work on the synthesis of hydrazine, starting substance of the various derivatives, has been performed before, with the materials produced in Korea by applying the Rasching method. The Rasching mothed is the only satisfactory one for synthesizing hydrazine; it involves the oxidation of ammonia by sodium hypochlorite in the presence of some such catalyst as gelatin. Calcium hypochlorite was substituted for the sodium hypochlorite partcularly in this work, applying agar-agar as catalyst. As a result an increase in the yield of hydrazine was obtained. Recently I have worked quantitatively on the fact that calcium hypochlorite gives more favorable result than sodium hypochlorite. The results of the experiments are as follow; 1. When calcium byphchlorite is applied in place of sodium hypochlorite, the yield of hydrazine is increased as much as 17%. 2. The yield of hydrazine is decreased by eliminating the suspension of Ca(OH)_2 which results from the use of calcuim hypochlorite. 3. When Ca(OH)_2 is added to Rasching process, the yield of hydrazine is raised normally. 4. The fact that some metal ions, such as Cu^++, inhibit the formation of hydrazine was proves. 5. The suspension of Ca(OH)_2 acted as a remarkable absorbent for Cu^++ gelatin. The suspension of Ca(OH)_2 which results from the use of calcium hyphchlorite acts as a catalyst, absorbing metal ions, to increase the yield of hydrazine. So I think that calcium hypochlorite is a more efficient oxidant than sodium hypochlorite in hydrazine synthesis.

重金屬이온의 除去를 위한 새로운 이온 交換樹脂製造에 關한 硏究

李學沂,金祐埴,金淳植 慶北大學校 1981 論文集 Vol.32 No.-

Crosslinked polyacrylamide was prepared from acrylamide and divinylbenzene by the radical polymerization in methanol to prepare crosslinked polyvinylamine by the Hoffmann reaction. A Crosslinked aminocarboxylic acid resin was finally prepared by the reaction of the crosslinked polyvinylamine and chloroacetic acid. Another Aminocarboxylic acid resin was also prepared to make reference to the reaction of the crosslinked polyvinylamine with chloroacetic acid. The ion exchange capacities of the crosslinked aminocarboxylic acid resin for Zn^+2, Cu^+2, Co^+2, and Ni^+2 varied with pH and proved to be relatively high with the pH range of 6-7. The order of ion exchange for heavy metal ions was Zn^+2〉Cu^+2〉Co^+2〉Ni at the above pH region.

폴리프로필렌 纖維用 Carbene染料의 開發에 關한 硏究

李學沂,林龍進,민경은 慶北大學校 1982 論文集 Vol.33 No.-

Reactive dyes, which reaction center is carbene, were prepared and the dyeability of polypropylene fiber by those dyestuffs was investigated. Furthermore, a new say of dyeing and an applied technique for pretreating polypropylene with carbenic precursor were studied to improve dyeability. In this experiment, ketones were used as starting materials because these are mostly common functional group in dyes and dyestuff intermediates. Ketones could be changed to tosylhydrazone derivatives by tosylhydrazine in methanol at 0℃ in the presence of aqueous hydrochloric acid. Reactive carbenic dyes were prepared by the reaction of n-butyllithium and these hydrazone derivatives in ethly ether solvent. Dyed polypropylene showed excellent endurance to the light and preserverance to laundry, which were confirmed by means of blue and gray scales. The fact that polypropylene was bonded covalently to dyestuff molecules was confirmed by extraction and reprecipitation. Using the aldehyde as the starting material, carbenic precursor was also prepared analogous route to the dyestuff. After pretreating polypropylene fiber with this precursor, dyeing pattern of fiber in acidic media with butyl orange showed similar adsorption curve which is the typical results of acidic dyeing process. It means that polypropylene could be dyed easily in acidic media if it had pretreated by carbenic precursor.