리튬이차전지용 부극재료로서 은분말에 대한 전기화학적 특성

박철완,도칠훈,문성인,윤문수 한국공업화학회 2003 응용화학 Vol.7 No.2

Silver powders have been extensively studied as an anode active material for lithium secondary batteries. In the present study, a unique attempt is made to develop silver negative electrode by slurry method, because the silver electrode is a good candidate to replace the commercial graphite electrode for lithium rechargeable batteries. Silver electrode was prepared and its electrochemical properties were characterized gradual increasing test state of charge (GISOC) analysis method. Charge-discharge performance indicates that the initial charge potential range of Li/Ag cells has showed similar behaviors compared with Li/Graphite system and the irreversible capacity facd is also higher than Li/Graphite system.

한국의 전자민주주의 : 정부부문을 중심으로

김용철,이축묵, 윤성이 연세대학교 동서문제연구원 2001 東西硏究 JOURNAL OF EAST AND WEST STUDIES Vol.13 No.1

본 논문은 정부의 정보제공 방식과 특성을 파악하고, 가상공간에서 정부와 시민 사회간의 의사소통 내용을 분석함으로써, 정부부문에서의 전자민주주의 현황을 평가함과 동시에 이의 실현을 위한 구체적인 방안을 모색하는 것을 목적으로 한다. 정보제공과 관련하여, 공개하는 정보의 질과 양, 그리고 자료의 갱신주기 등은 정부부처에 따라 매우 상이한 것으로 나타난다. 일반적으로 인터넷으로 제공되는 정보의 질적 · 양적 수준은 대민접촉이 빈번하고 국민 실생활과 직접 관련되는 부서(즉, 교육부, 노동부, 보건복지부, 환경부 등)일수록 높은 것으로 보인다. 반면, 대민접촉이 그다지 활발하지 않은 부서의 경우 상대적으로 정보에 대한 수요가 많지 않고, 그에 따라 정보의 수준도 낮은 것으로 판단된다. 한편 정보의 보다 효율적인 제공을 위한 방안으로서, 정부 홈페이지는 현재 관련 사이트에만 국한되어 있는 항해기능을 좀 더 확대하여 정보유통 네트워크의 핵심 결절점 역할을 수행할 필요가 있다. 이를 위해서는 관련 연구소의 주요 정보, 즉 정책정보, 현황정보, 통계정보 등의 목록 및 소재 정보를 제공하고 그에 연계될 수 있는 링크기능을 확보해야 한다. 아울러 모든 정부기관이 보유하고 있는 현황정보나 정책정보에 대해 총괄적으로 검색할 수 있는 기능을 담당하는 기관으로서 청와대 홈페이지의 위상을 재정립 할 필요가 있다. 청와대는 행정부 전체의 활동을 총괄적으로 관장하는 기관이며, 또한 현재 홈페이지 접속 빈도도 매우 높기 때문에 이 기능을 수행하는데 가장 적합하다고 볼 수 있다. 가상공간에서 정부와 시민간의 의사소통은 진지하고 건설적인 방식으로만 이루어지지 않는 것으로 보인다. 행정상담이나 정보요청을 제외하면, 대부분은 항의성 메일, 일방적인 비난 · 비방으로 채워져 있고, 정책토론이나 정책건의와 같은 발전적인 논의는 극히 일부라고 볼 수 있다. 그러나 가상공간을 '사이버 아고라'로 만들려던 정부의 시도가 별 성과를 거두지 못한 데에는 정부의 안이한 대응에도 책임이 있다. 따라서 정부는 의사소통의 공간을 체계적으로 조직화 할 방안을 도출해 야 한다. 우선 행정상담 및 시민게시판의 효과적인 운영을 위해서는, 문의란과 답변란의 구별운영, 담당자의 즉각적 회신, 분야별 Q&A의 활성화 등이 시급하다. 둘째, '자유게시판' 코너의 운영을 개선하기 위해서는, 시민들의 의견에 대해 담당기관에서 적극적으로 대응할 필요가 있다. 또한 게시판의 주제에 맞지 않는 내용에 대해서는 네티즌의 의견을 물은 후 삭제하거나, 게시자에게 경고 후 접근을 제한하는 방법도 신중하게 고려할 필요가 있다. 셋째, 주제별 정책토론의 생산적 결과를 위해서는, 주제선택에 있어서의 시의성 고려, 토론에 필요한 자료의 확보, 담당자들의 적극적인 개입, 그리고 토론성과를 통한 정책반영 노력 등이 필요할 것이다.

수축저감제 혼입률 변화에 따른 콘크리트의 공학적 특성에 관한 연구

한민철,金光華,정규문,정평유,윤성노,한천구 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2

In this paper, tests are carried out using concrete incorporating shrinkage reducing agent(SR) in order to investigate the engineering properties of concrete. The contents of SR and W/C are varied. According to test results, as for fresh concrete, as SR content increases, slump and air content shows decline tendency, and setting time is accelerated with increase of SR content and decrease of W/C. As for compressive strength, as SR contents increases compressive strength shows to be decreased. As for the effect of SR on drying shrinkage, it shows to be reduced with increase of SR content. This is due to the reduced surface tensile strength of water and tensile strength of capillary pore in concrete.

부산지역 청년들의 부산에 대한 인식 : 청년 정책을 위한 함의

남성주(외 2명) 신라대학교 부산학연구센터 2016 부산연구 Vol.14 No.-

이 연구는 부산지역 거주 청년 500명을 대상으로 부산시에 대한 인식을 조사하였다. 조사결과 일자리 문제를 제외하고 응답자들은 부산에 대해 대체로 긍정적인 평가를 하는 것으로 나타났으며, 부산의 미래에 대해 낙관적인 기대를 가지고 있었다. 다만 서부산권 거주자들의 만족도가 동부산권 거주자들에 비해 상대적으로 낮았다. 설문조사 결과를 토대로 정책적 함의를 논의 하였다.

생물전극 반응조를 이용한 영양물질 제거

김성완,윤철종,최성우,김성우,우성훈,신남철,박승조 동아대학교 환경문제연구소 1999 硏究報告 Vol.22 No.2

We have investigated a performance of bio-electrode reactor for removal of nutrient like a nitrogen, phosphorus and organic substrate. Lab scale of bio-electrode reactor was operated with synthetic and tannery wastewater. Iron bar and stainless steel used for anode and cathode respectively. In experiment with synthetic wastewater, we were able to obtain the optimal current density range of 2.4-40 mA/dm² after 48 hrs operating time. And in that experiment, about 70~73% of ammonia nitrogen and 54~64% of phosphorus were removed. In experiment with tannery wastewater at 2.4-4.0 mA/dm², the removal rate of ammonia nitrogen, phosphorus and organic substract were about 62-69%, 45~59% and beyond 79% respectively.

회맹장 및 대장을 침범한 장 결핵에 있어서 바륨을 이용한 방사선 이중조영촬영 소견에 대한 연구

진용현,전혜정,이용근,강철호,조성범,김윤환,박철민,차상훈,김일영,이혜경 건국대학교 의과학연구소 2002 건국의과학학술지 Vol.12 No.-

To determine the characteristic double contrast barium enema findings of ileo-cecal and colonic tuberculosis and to make differential diagnosis from other bowel inflammatory disease. Sixty-seven patients confirmed as ileo-cecal and/or colonic-tuberculosis in six hospitals were evaluated retrospectively. The diagnosis was proven by endoscopic biopsy, surgery, and clinical follow up. Nine of 67 patients were excluded because radiologic findings were normal though endocopic biopsy examinations resulted in tuberculosis. Histopathological diagnosis were madein 58 cases as follows: endoscopic biopsy(n=29), operation(n=12), follow up examination(n=14), tissue culture(n=1), laparoscopic biopsy(n=2). There were 30 men and 28 females. The mean age were 36 yrs(range:16-67), 34 patients were in the second and third decade. The distribution of lesions, morphological characteristics, mucosal changes, ulcer shape and depth, associated with other tuberculous lesion, multiplicity were retrospectively analyzed in the findngs of double contrast barim enema. The commonest clinical symptoms were abdominal pain(n=35, 60%) and diarrhea(n=18, 31%). The chest radiography revealed association of pulmonary tuberculosis in 39 cases. Tuberculous lesions of other organs except chest were present in five cases. Double contrast barium enema findings showed a thickening and irregularity of intestinal mucosal fold(n=29, 50%), bowel contraction and/or shortening(n=26, 45%). There were small, nodular, superficial ulcers in the case of ulcer depth less than 2 mm in the depth. As many as 39 cases(67%) in this series had two or more lesions in the intestinal tuberculosis. The involved segment revealed symmetrical feature(n=21, 36%). Inflammatory pseudopolypoid lesions were noted in 30 cases(52%). The ileo-cecal region was involved in 38 cases(66%). The ascending colon(n=25, 43%) was the second commonest site with or without contiguous cecal involvement. Lesions in terminal ileum, ileo-cecal valve, transverse colon, descending colon and appendix were seen in 19, 18, 18, 12 and seven cases, respectively. Among 18 cases of ileo-cecal valve lesions, there were incompetency in nine cases(16%) and wide gapping in four cases(7%). In 14 cases, tuberculous enterocolitis was diagnosed by clinical follow-up and double contrast barium enema study. 12 out of 14 cases, the findings of double contrast barium enema of tuberculous enterocolitis were normalized after anti-tuberculous medication. However, two cases showed more aggravated state than before due to inappropriate treatment. Double contrast barium enema plays an important role in the diagnosis of tuberculous enterocolitis, determines the type, site and extent of the involvement and helps in treatment guide by using sequential studies.

직업적 아크릴아미드 폭로에 의한 다발성 신경병증

정해관,권용욱,어경윤,김병준,양정선,정철,진영우,이미영,강성규 大韓産業醫學會 1998 대한직업환경의학회지 Vol.10 No.3

Authors report a first Korean case of polyneuropathy in an acrylamide producing factory together with an environmental and epidemiologic survey for the ten workers of the same workplace and 46 workers in the production and manufacturing acrylamide in Ulsan, Korea. The case is 30 years old man who worked in the production of the acrylamide for two years. In August, 1997, he had a weakness of the lower extremity with loss of body weight of 15 Kg which progressed to paresthesia of the limbs, the loss of vibration sense, difficulty in walking, speech disturbance, dysuria, constipation, difficulty in erection and swallowing difficulty. Neurologic examination showed a complete loss of vibration and position sense, and loss of deep tendon reflex in all the limbs. There was a contact dermatitis-like skin lesion on the feet. Electrodiagnostic test showed a generalized polyneuropathy of moderate degree involving motor and sensory component of peripheral and cranial nerves. After 8 months' cessation from exposure and supportive care, his symptoms were completely resolved, but abnormality in electrodiagnostic test and vibrotactile perception threshold still persisted, although much improved than before. There were 11 workers in the same workplace of the case, producing acrylamide by microorganism as a catalyst. Environmental monitoring of the workplace revealed air borne concentration of the acrylamide to be from 0.05 to 0.23 mg/m3 by personal sampling and from 7.65 to 11.65 mg/m3 by area sampling during filter exchanging process, which far exceeds TLV-TWA of 0.03 mg/m3. However, acrylamide was not detected from the plasma of the workers. Symptom questionnaire showed a markedly higher complain of neurologic symptoms, compared to the workers of the other acrylamide producing companies. Electrodiagnostic test showed a several workers are in the lower normal range without definite abnormality. Vibrotactile perception threshold by Vibratron Ⅱ showed a significantly increased threshold in the workers of the same workplace compared to the other acrylamide workers and significantly decreased test score of color vision compared to normal controls. After improvement of the production process and strict wearing of the protective device, most workers reported the improvement of clinical symptoms, but vibrotactile perception threshold was not improved. These result suggests the need for the effective environmental monitoring together with a periodic biological monitoring. Development of effective screening test is urgently needed to control and assess the skin absorption of acrylamide.

압출용 다이스의 Melt-고분자 열유동 기초연구

정효희,김재열,최진호,유신,윤성운,홍철,김종문 한국공작기계학회 2008 한국공작기계학회 춘계학술대회논문집 Vol.2008 No.-

As importance part of extruder, hopper(Hopper) been raw material supply wealth, main frame that screw and barrel that transformation of supply raw material attains are because deformed raw material is fearful finally extrusion to done dies attain. Extruder is divided by greatly above 3 but hopper has assembled in dehumidification of raw material and supply of smooth raw material, and make in Melt state as raw material is stabilized because main frame consists of screw and barrel and Melt does anaphora as done material is stabilized. And dies that is last part between barrel with screw anaphora done Melt material as is stabilized without causing change that is much depending on anaphora of screw from dies way out as correct product produce make to. In this treatise, make anaphora can present ideal dies basis design using CFdesign that is heat & flow analysis programs so that can produce detailed product through pipe channel flow analysis of stable dies applying anaphora value of do polymer raw material in Screw.

A 6.5 - 8.5 GHz CMOS UWB Transmitter Using Switched LC VCO

Yun Seong Eo,Myung Cheol Park,Min-Cheol Ha 대한전자공학회 2015 Journal of semiconductor technology and science Vol.15 No.3

A 6.5 ? 8.5 GHz CMOS UWB transmitter is implemented using 0.18 μm CMOS technology. The transmitter is mainly composed of switched LC VCO and digital pulse generator (DPG). Using RF switchand DPG, the uniform power and sidelobe rejection are achieved irrespective of the carrier frequency. The measured UWB carrier frequency range is 7 ~ 8 GHz and the pulse width is tunable from 1 to 2 ns. The measured energy efficiency per pulse is 2.1 % and the power consumption is 0.6 mW at 10 Mbps without the buffer amplifier. The chip core size is 0.72 ㎟.

Successful Removal of Endobronchial Lipoma by Flexible Bronchoscopy Using Electrosurgical Snare

Seong Cheol Yun,Moon Jun Na,Eu Gene Choi,Sun Jung Kwon,Seong Ju Lee,Sun Hee Oh,Eun Jung Cha,Ji Woong Son 대한결핵 및 호흡기학회 2013 Tuberculosis and Respiratory Diseases Vol.74 No.2

A 62-year-old man with a chronic cough presented with atelectasis of the left upper lobe on chest X-ray. Chest computed tomography showed an atelectasis in the left upper lobe with bronchial wall thickening, stenosis, dilatation, and mucoid impaction. We performed bronchoscopy and found a well-circumscribed mass on the left upper lobe bronchus. The mass was removed by flexible bronchoscopy using an electrosurgical snare and diagnosed with lipoma. An endobronchial lipoma is a rare benign tumor that can be treated by a surgical or endoscopic approach. We report the successful removal of endobronchial lipoma via flexible bronchoscopic electrosurgical snare.