Effect of polydopamine‑modified reduced graphene oxides on the catalytic activity of Pt nanoparticles catalysts for fuel cell electrodes

Joo‑Hyoeng Woo,Soo‑Jin Park,Sungwook Chung,Seok Kim 한국탄소학회 2019 Carbon Letters Vol.29 No.1

We have studied a method to prepare polydopamine-modified reduced graphene oxide-supported Pt nanoparticles (Pt– PDA–RGO). The Pt–PDA–RGO nanocomposites were synthesized by a wet-coating process, which was induced by selfpolymerization of dopamine. As an eco-friendly and versatile adhesive source in nature, dopamine could be easily adhered to surfaces of organic material and inorganic material via polymerization processes and spontaneous adsorption under weak alkaline pH conditions. To apply the unique features of dopamine, we synthesized Pt–PDA–RGO nanocomposites with a different quantity of dopamine, which are expected to preserve the improved Pt adsorption on graphene, resulting in the enhanced electrocatalytic performance. The morphology and micro-structure were examined by field emission scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy. Compared to pristine Pt–deposited RGO (Pt–RGO), Pt–PDA–RGO (30 wt% dopamine against RGO) nanocomposites showed a superior electrochemical active surface area for a methanol oxidation. This could be related to the fact that the optimized c

Captopril과 Nifedipine 병합요법의 강압효과에 관한 임상적 연구

이영수,문언수,김준호,공수정,정시진,주용진,정상만 건국대학교 의과학연구소 1993 건국의과학학술지 Vol.3 No.-

Background: The hypotensive effect of captopril(angiotensin converting enzyme inhibitor) and nifedipine(calcium channel blocker) was studied. Method: Captopril(75mg) and nifedipine(30mg) were administered in 30 hypertensive adults during twelve weeks after a week observation for washout with stepwise increments of the dose according to the patient's blood pressure in every two weeks. Result: The supine blood pressure were decreased from 169.5±22.3/104.0±20.3 mmHg to 130.4±21.3/82.4±19.5mmHg at the end of twelve weeks during therapy.(p<0.05) The standing blood pressure were also decreased conferrably and to the some lower level. Hematologic examination and blood chemistry revealed no discernible abnormal findings before and after the treatment. During the period of the study a few probably drug-related symptom such as cough and headache, gastrointestinal disturbance developed but not troublesome enough to administering. Conclusion: Captopril and nifedipine regimen is well tolerated and effective in the treatment of hypertensive patients.

Kim,Seong-soo : Possiblity of Low Salting Process in Gae-Woo Jeot(Salted and Fermented Gastrophoda) and Changes in Fatty Acid Composition during Fermntation 低鹽化 可能性 檢討 및 熱成중 脂肪酸 組成의 變化

姜永周,河璡桓,金永東,宋大鎭,金洙賢,金成洙 제주대학교 1990 논문집 Vol.30 No.-

To establish the way of processing of Gae-Woo jeot which used abalone intestine that has not been systematically used compare to its characteristic taste and fame as main ingredient and to develop as a local tourist good, the change of constituents the quality of salted fish products suring Gae-Woo jeot fermentation were examined. The results are as follows. 1. In the organoleptic test, Gae-Woo jeot which fermented through 65 days were dominant and the group of 105 salkt concentration were better than that of 20%. It was the best of 10% salted products to add small abalone. Both law salted(10%) and high salted (20%) Gae-Woo jeot were similar in general constityents, nutrients and texture. 2. Compositions of highly unsaturated acid were farely high to 45.6% and 46.1% in small abalone added froup and top sheel added group respectively. during 3 months fermentation low decreasing rate of 3~4% was shown. EPA(eicosapentaenoic acid) was approximately 7~8% and DHA(docosahexaenoic acid) was extremely low to be less than 0.3%. 3. In the changes General composition and pH, pH was within range of 4~5.5, 9~12% in protein, 3~5% in total sugar, 0.5~1% in lipid and approximately 1% in ash. 4. Gae-Woo jeot can be made with 10% low salting method, and 10% group gets all the better for taste, small abalone adding is recommended. 5. When low salt fermented fish of 10% is processed, it is highly recommended to put sorbitol, ethyl alcohol, lactic acid or other humectant for better taste and longer storage and good quality food additives must be developed for tourist and presently applied mil ordering transportation must be sought.

케타민과 리도카인으로 시행한 소아 탈장 수술 2,230명

주종수,주현호,주인호,Joo, Jong Soo,Joo, Hyun Ho,Joo, In Ho 대한소아외과학회 2013 소아외과 Vol.19 No.2

Ketamine is a safe and effective drug for pediatric anesthesia, sedation and analgesia. We hoped to identify that surgeons could operate a pediatric hernia with the ketamine anesthesia without general anesthesia. The study was a consecutive case series of 2230 inguinal hernia patients aged 1 months to 17 years in a Joo's day-surgical clinic during 11-year period. The patients had pediatric inguinal hernia surgery without general anesthesia under the day-surgery system. We retrospectively analyzed the medical record of patients who were registered with the Diagnosis Related Group (DRG) system. All patients received ketamine (5mg/kg) and atropine (0.01mg/kg) intramuscularly before surgery. After anesthesia, we injected 1~2% lidocaine (Less than 5ml) subcutaneously at the site of incision and started operation. The surgical method was the high ligation method of the hernia sac.) In total 2230 patients, male were 1756 and female were 474. 2076 patients were a unilateral inguinal hernia at the time of surgery and 154 were bilateral hernia patients. Less than three months, depending on the age of the patients was 391, and less than 12 months the patient was 592 people (26.5%). After surgery, there were no accidents or long term complications associated with ketamine anesthesia. We think the surgeon can safely do the pediatric inguinal hernia surgery using ketamine and lidocaine without anesthesiologist through 11 years of our surgical experiences.

流行病 管理의 數學的 모델化

周秀元 동아대학교 공과대학 부설 한국자원개발연구소 1985 硏究報告 Vol.9 No.2

The new epidemic model, while remaining essentially deterministic in nature, incorports a very desirable feature of stochastie models by representing the latent and infectious period of disease by their mean values and respective standard deviation. The effect of application and variation of each of the active and passive vaccination controls has also been studied.

Urban Entertainment Center 사업과 지역경제의 파급효과 분석

주수현,허정옥,진금옥,강상주 동의대학교 경제경영전략연구소 2006 經濟經營硏究 Vol.4 No.1

This research is designed for conducing spreading effects of regional economy by analyzing Input-Output Model(i.e. production model, employment model, value model, and income model). These measures of spreading effects in regional economy were determined by precise analyses of feasibility and demands of public businesses. That would be effective and confident polices and supportive for long time in the regional ecinimy. One of the most effectibe analysis on the spreading effects of regional economy is draw up Input-Output Model(IOM). This article, based on 2000 IOM of Busan Area, is focused that how the turbulence level of final demands affected spreading effects of regional economy, such as industrial production, value added, employment, incom etc. Also there were included the analysis of economic analyses of spreading effects on the UEC in the Centum City businesses.

磁氣抵抗 電動機의 特性解析에 關한 硏究

周秀元,李承煥 東亞大學校 1974 東亞論叢 Vol.11 No.2

一般的으로 圓筒型 回轉子를 가진 3相交流電動機의 磁界 解析에서 空隙은 一定하고 回電子捲線 電流에 의한 起磁力이 空隙起磁力에 포함된다. 本 論文에서는 空隙起磁力은 固定子捲線 電流에 의한 起磁力만이며 空隙이 圓周方向의 變數라는 점을 감안함으로써 磁氣抵抗 電動機의 解析에 圓筒型 回轉子 電動機의 磁界 解析에 의한 解析法을 適用하였다. 解析에 使用된 segmental rotor는 從來의 回轉子와 다르며 이 兩機器의 磁氣回路와 特性을 비교검토하였다. 直軸 리액턴스는 機器 構造를 나타내는 定數들로 表現되므로 모든 特性方程式도 이 定數들과 負荷角으로 나타난다. 故로 回轉子의 構造를 바꾸어서 特性을 改善할 수 있다. 定常狀態의 動作特性은 Stroboscope에 의해 測定된 負荷角에 의해 決定되었고 計算값과 잘 一致했다. Generally in the analysis of magnetic field of three phase moter which has cyrindrical rotor air gap is constant and the magneto motive force of rotor winding current is cont ned in the magnetomotive force of the air gap. In this paper, the method of the analysis of magnetic field of three phase motor was adaped in analysis of reluctance motor in which only the MMF of the stator winding exist in the MMF of the air gap and the air gap is a variable along the cyhindrical direction. The segmental rotor used in this analysis is different from the conventional one and the difference of the magnetic circuits and the performance characteristics was compared and reviewed. Since dirct-and quadrature-reactance are described with the constants which is rendered to machine configuration, all the characteristic equations is represented with this constants and load angle. And so the characteristics of this motor is improved by changing the rotor structure. The steady state performance was made by the load angle which is measured by the stroboscope. The results well coincided with the values of the computation.

국내 의료종사자에서 HHV-8의 항체양성률에 대한 연구

주우철,최용준,박재은,이혜명,이진수,정문현,김수미,문지혜 대한감염학회 2008 감염과 화학요법 Vol.40 No.4

HHV-8 virus is known to be associated with Kaposi's sarcoma (KS) in HIV seropositive patients and its seroprevalence has geographic difference, In South Korea, incidence of KS is low not only in general population but also in HIV patients compared to other countries, It is speculated that low seroprevalence of HHV-8 has contributed to the low incidence of KS in South Korea. We examined the seroprevalence of anti HHV-8 IgG of HIV seronegative health care workers in one University hospital. Enzyme-linked immunosorbent assay(ELISA) was used for diagnosis. One person (0.6% 1/164) was seropositive, six were equivocal (3.7%,6/164) and 157 people were seronegative (95.73%, 157/164). This study revealed that seroprevalence of HHV-8 in general population was. low in South Korea. Further studies are needed to be carried out to evaluate the low HHV-8 seroprevalence in Korea.

簡略系統特性定數에 의한 調相設備의 最適計算法

周秀元,金權洙,鄭亨煥 동아대학교 공과대학 부설 한국자원개발연구소 1985 硏究報告 Vol.9 No.1

This study aimed at seeking system characteristic constant in power system as simple as possible and, by using it, calculating optimum reactive power source. The results are as follow. 1. The theory employed in this research showed the excellence of obtaining system characteristic constant as fast as possible. 2. Any system characteristic constant reasonable to the system's flow condition, whether it was on heavy or light load, was to be obtained. 3. The validity of the theory was affirmed by some calculating examples in terms of model system.

장기간 중강도 유산소성 운동이 심부온과 피부온에 미치는 영향

주동엽,김수근,정동혁 한국스포츠리서치 2003 한국 스포츠 리서치 Vol.20 No.1

This study is aimed at investigating the changes in core temperature and skin temperature of human body affected by moderate intensity aerobic exercise training. Subjects were 20 male university students to trace the change in skin temperature and rectal temperature when they undergo exercises 30 minutes a day, five days a week for 12 weeks at anaerobic threshold. In order to process the collected data, the mean and standard deviation values were calculated from the results of each item measured for two groups. One way repeated measure ANOVA was applied to find out the change with the lapse of time, while Student's t-test was used to ascertain the average difference between the two groups and Newman-Keuls test as the post-hoc. The significance level was set at 5%. The followings are the conclusion of the study conducted to examine the effects of long-term moderate intensity aerobic exercise on skin temperature and rectal temperature; First, the local skin temperature decreases generally on all body parts except on feet in the non-exercise group, whereas, it maintains the usual state on all except on hands, thighs and feet in the exercise group. Second, the non-exercise group shows decrease in skin temperature lower than average of normal state during the time from the start of excercise to recovery, while the mean skin temperature of exercise group increases generally compared to normal state. Summed up, the long-term moderate intensity aerobic exercise is believed to activate the sweat-secreting mechanism of human body and to induce to push up the skin temperature by means of rising heart rate thanks to the improved blood circulatory function, local blood flow gain and improved thermo-regulatory vascular expansion function. It comes, therefore, true that the moderate intensity aerobic exercise might affect the skin temperatures and that the moderate intensity aerobic exercise is directly connected with the thermo-regulatory function of our body.