• Korean Chemical Engineering Research
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• 제55권4호
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• pp.483-489
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• 2017

The loss of the sulfur cathode material through dissolution of the polysulfide into electrolyte causes a significant capacity reduction of the lithium-sulfur cell during the charge-discharge reaction, thereby debilitating the electrochemical performance of the cell. We addressed this problem by using a chemical and physical approach called reduction of polysulfide dissolution through direct coating functional inorganic (graphene oxide) or organic layer (polyethylene oxide) on electrode, since the deposition of external functional layer can chemically interact with polysulfide and physically prevent the leakage of lithium polysulfide out of the electrode. Through this approach, we obtained a composite electrode for a lithium-sulfur battery (sulfur: 60%) coated with uniform and thin external functional layers where the thin external layer was coated on the electrode by solution coating and drying by a subsequent heat treatment at low temperature (${\sim}80^{\circ}C$). The external functional layer, such as inorganic or organic layer, not only alleviates the dissolution of the polysulfide electrolyte during the charging/discharging through physical layer formation, but also makes a chemical interaction between the polysulfide and the functional layer. As-formed lithium-sulfur battery exhibits stable cycling electrochemical performance during charging and discharging at a reversible capacity of 700~1187 mAh/g at 0.1 C (1 C = 1675 mA/g) for 30 cycles or more.

• Bulletin of the Korean Chemical Society
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• 제29권12호
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• pp.2379-2382
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• 2008

• 대한화학회지
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• 제18권5호
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• pp.363-367
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• 1974

니트릴, 니트로 및 할로겐과 같은 작용기 하나를 가지는 유기화합물과 이들의 작용기 하나와 더불어 카르보닐기를 가지는 10개 유기화합물의 에테르용액을 실온에서 알칼리성 수소화붕소나트륨용액에 작용시키는 2액상환원의 대략적인 반응속도와 화학량적 관계를 알아보았다. 니트릴, 니트로 및 할로겐은 2액상환원 조건하에서는 모두 반응하지 않았다. 따라서 이들 작용기 하나와 카르보닐기를 함께 가지고 있는 화합물들의 선택환원을 알아보았다. m-니트로벤즈알데히드, m-니트로아세트페논, p-시아노벤즈알데히드는 해당 알코올로 잘 환원되었으며 95∼100% 수득률을 얻었다.

• 국제물리치료학회지
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• 제4권1호
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• pp.499-504
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• 2013

This study aims to address the effect of interferential current therapy and thereby to provide basic resources to physical therapies for internal medicine by identifying symptoms for functional dyspepsia and serum gastrin level that shows gastric motility. Following results were obtained by performing interferential current therapy to 16 subjects composed of 8 for functional dyspepsia group and 8 for control group for 20 minutes a day, 3 days a week, for 6 weeks. In control group, serum gastrin level was significantly( p<.01), lowered after the therapy whereas there was no significant difference observed in all questions from questionnaire for symptoms of functional dyspepsia between before and after the therapy. In functional dyspepsia group, serum gastrin level was significantly(p<.01), lowered after the therapy and there was also significant(p<.01) reduction in every question from questionnaire for symptoms of functional dyspepsia between before and after the therapy. There was more significant decrease in serum gastrin level and reduction in questionnaire for symptoms of functional dyspepsia in the functional dyspepsia group compared to the control group(p<.01). This study confirms the interferential current therapy as an effective therapeutic method for internal diseases including functional dyspepsia since it not only improves the symptoms of functional dyspepsia but also allows the gastric motility close to normal.

• 한국응용과학기술학회지
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• 제38권2호
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• pp.618-627
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• 2021

기능성 화장품이라 함은 피부미백, 주름개선, 자외선차단 등 특정한 기능을 가지고 피부에 효과를 주는 화장품을 말했다. 그런데 2017년 이후 기능성 화장품의 품목이 확대되었다. 대한민국의 기능성 화장품 산업은 미백, 주름, 자외선 차단 제품에 머물고 새로운 기능성 제품의 개발은 미비한 상태이다. 또한 코스메슈티컬과 메디컬 화장품을 비롯한 고기능성 화장품도 아직 정립되지 않은 상태이다. 그리고 국외에 수출실적 순위는 프랑스가 가장 높았고 미국, 독일 순으로 나타났다. 프랑스는 화장품 산업 업계 1위 국가답게 바이오 공업과 기능성 소재에서 메커니즘 중심의 기능성 화장품을 강조하고 있고 미국은 럭셔리 프리미엄 제품에 수요도가 높았으며 독일은 바이오 하이테크 기술에 주목하고 있다. 이처럼 한국도 신흥 산업에 적용할 수 있는 기능성 화장품들의 새로운 소재들을 개발하고 정치와 경제가 뒷받침 되어 연구에 더 집중할 수 있는 환경이 갖춰져 다양한 기능성 화장품 산업 등을 발전시켜 나아가야 할 것이다.

• Korean Chemical Engineering Research
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• 제61권4호
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• pp.604-610
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• 2023

주변 조건에서 N₂를 환원하여 NH₃를 생성하는 전기 촉매 질소 환원 반응(nitrogen reduction reaction, NRR)은 산업공정에서 에너지 소비를 감소시킬 수 있는 유망한 기술로 주목을 받고 있다. N₂를 흡착하고 활성화할 수 있는 촉매 금속 표면 중 많이 사용되는 Ni(100) 표면의 여러 사이트(site)의 흡착 성능을 밀도 함수 이론 계산(density-functional theory)를 기반으로 비교하였다. 또한 안정적인 NRR반응의 경로를 유도하는 N₂의 두 가지 흡착 구조를 조사하였고 end-on 구조는 top site에 흡착, distal pathway로 반응이 진행되고 side-on 구조는 bridge site에 흡착되며 enzymatic pathway로 반응이 진행되었다. 마지막으로 구조 별 가장 안정한 메커니즘의 깁스 자유에너지를 구하여 반응의 경향성을 알아봄으로써 NRR 반응의 금속 촉매 표면 흡착에 대한 연구에 도움이 될 수 있을 것이다.

• 시스템엔지니어링학술지
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• 제10권2호
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• pp.15-20
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• 2014

The river crossing is a very challenging operational function for the ground wheeled vehicle. In this study, the typical hazardous elements were identified by analysing the functional flow of river crossing operation and the survey on the similar operational experiences in real fields. The identified hazardous elements were reviewed on the basis of ALARP concept and reduction approaches were recommended for limited cases.

• 대한물리의학회지
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• 제15권4호
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• pp.87-99
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• 2020

PURPOSE: This study examines the therapeutic effect of functional adjustment procedure therapy (FAPT), by comparatively analyzing behavioral disorders due to shoulder pain and subjective pain intensity subsequent to therapy, in patients with shoulder pain. METHODS: The intervention was performed on 48 employee patients with shoulder pain, Patients were administered 16 sessions of FAPT for 8 weeks, twice a week for 30 minutes per session. This study applied the neck pain and disability scale (NPDS) as a measurement tool, and used the questionnaire to measure subjective pain intensity to investigate the difference before and after administering FAPT to employee patients with shoulder pain. RESULTS: Statistically significant difference was obtained between the mean difference in shoulder pain disorder, before and after FAPT. Assessing gender and age differences in the reduction effect of shoulder pain, showed significant difference in 8 of the 10 factors examined. Finally, examining the difference in the effect of reducing subjective shoulder pain by gender and age, we observed that gender-based disability reduction was significant for all 12 factors examined. CONCLUSION: Taken together, the results of this study, validate the therapeutic efficacy of FAPT for patients with shoulder pain. We believe that this data will provide basic information to understand the health conditions and psychological variables of patients with shoulder pain.

• Bulletin of the Korean Chemical Society
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• 제13권5호
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• pp.531-537
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• 1992

The approximate rates and stoichiometry of the reaction of excess potassium 2-thexyl-1,3,2-dioxaborinane hydride(KTDBNH) with 55 selected compounds containing representative functional groups under standardized conditions (tetrahydrofuran, TEX>$0^{\circ}C$, reagent : compound=4 : 1) was examined in order to define the characteristics of the reagent for selective reductions. Benzyl alcohol and phenol evolve hydrogen immediately. However, primary, secondary and tertiary alcohols evolve hydrogen slowly, and the rate of hydrogen evolution is in order of $1^{\circ}$> $2^{\circ}$> $3^{\circ}$. n-Hexylamine is inert toward the reagent, whereas the thiols examined evolve hydrogen rapidly. Aldehydes and ketones are reduced rapidly and quantitatively to give the corresponding alcohols. Cinnamaldehyde is rapidly reduced to cinnamyl alcohol, and further reduction is slow under these conditions. The reaction with p-benzoquinone dose not show a clean reduction, but anthraquinone is cleanly reduced to 9,10-dihydro-9,10-anthracenediol. Carboxylic acids liberate hydrogen immediately, further reduction is very slow. Cyclic anhydrides slowly consume 2 equiv of hydride, corresponding to reduction to the caboxylic acid and alcohol stages. Acid chlorides, esters, and lactones are rapidly and quantitatively reduced to the corresponding carbinols. Epoxides consume 1 equiv hydride slowly. Primary amides evolve 1 equiv of hydrogen readily, but further reduction is slow. Tertiary amides are also reduced slowly. Both aliphatic and aromatic nitriles consume 1 equiv of hydride rapidly, but further hydride uptake is slow. Analysis of the reaction mixture with 2,4-dinitrophenylhydrazine yields 64% of caproaldehyde and 87% of benzaldehyde, respectively. 1-Nitropropane utilizes 2 equiv of hydride, one for hydrogen evolution and the other for reduction. Other nitrogen compounds examined are also reduced slowly. Cyclohexanone oxime undergoes slow reduction to N-cyclohexylhydroxyamine. Pyridine ring is slowly attacked. Disulfides examined are reduced readily to the correponding thiols with rapid evolution of 1 equiv hydrogen. Dimethyl sulfoxide is reduced slowly to dimethyl sulfide, whereas the reduction of diphenyl sulfone is very slow. Sulfonic acids only liberate hydrogen quantitatively without any reduction. Finally, cyclohexyl tosylate is inert to this reagent. Consequently, potassium 2-thexyl-1,3,2-dioxaborinane hydride, a monoalkyldialkoxyborohydride, shows a unique reducing characteristics. The reducing power of this reagent exists somewhere between trialkylborohydrides and trialkoxyborohydride. Therefore, the reagent should find a useful application in organic synthesis, especially in the field of selective reduction.

• 대한두개안면성형외과학회지
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• 제20권1호
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• pp.24-30
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• 2019

Background: Closed reduction of the fracture under general or local anesthesia with elevators or forceps is widely used to treat nasal bone fractures. However, operating under general anesthesia increases the risk of morbidity and raises the cost of management. Furthermore, using forceps or elevators may cause undercorrection, new fractures, mucosal damage, and nasal hemorrhage. We therefore performed manual reduction under local anesthesia, using the little finger, to minimize the demerits of treatment under general anesthesia with forceps or elevators and aimed to assess functional and aesthetic outcomes, and patient satisfaction. Methods: Patients who visited the plastic and reconstructive surgery department between November 2016 and November 2017 with nasal bone fractures and treated by a single surgeon were prospectively followed up. Patients with simple unilateral or bilateral nasal bone fractures were treated with bedside finger reduction under local anesthesia and patients with comminuted nasal bone or septal fractures were scheduled for closed reduction under general anesthesia. Results: Of 84 patients, 28 met the inclusion criterion and underwent bedside finger reduction under local anesthesia. Twenty-seven patients (96.4%) were successfully contacted via telephone for survey. Twenty-three (85.2%) showed good and three (11.1%) showed fair results. All 27 patients (100%) were satisfied with their postoperative function and 25 (92.6%) were satisfied with their postoperative aesthetic result. Twenty-five patients (92.6%) preferred the finger reduction method under local anesthesia over closed reduction under general anesthesia. Conclusion: Finger reduction under local anesthesia in patients with mild unilateral or bilateral nasal bone fractures is an easy and efficient procedure with high patient satisfaction and favorable postoperative functional and aesthetic outcomes.