• Title/Summary/Keyword: pulse-energy

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Synthesis of Methanol from Carbon Dioxide (I). Study on Cu / ZnO Catalyst System (이산화탄소에 의한 메탄올 합성 (제 1 보). Cu / ZnO 촉매계 연구)

  • Sung Yun Cho;Ki Won Jun;Dae Chul Park;Kyu Wan Lee
    • Journal of the Korean Chemical Society
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    • v.33 no.5
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    • pp.558-567
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    • 1989
  • The synthesis of methanol from carbon dioxide and hydrogen was studied for various compositions of Cu/ZnO catalyst system. Effect of the composition ratio of CuO and ZnO on the catalytic activity in the above reaction and the relationship between the activity and the characteristics of the catalysts were explained from the result of surface area measurements, SEM, XRD, and XPS. The major products of the reaction were methanol and carbon monoxide. The selectivity to methanol increased with increase of the copper oxide content in the catalyst up to CuO: ZnO = 30:70 weight ratio, and decreased rapidly when the content is above 70%. SEM and BET measurements, indicate that this point corresponds to the increasing point of the catalyst crystallite size and the decreasing point of the surface area. As to the Cu/Cu + Zn atomic ratio, the surface concentration of copper measured by XPS decreased remarkably when the copper oxide content in catalyst was higher than 50%. All the unreduced catalysts had almost same binding energy of Cu(2P3) level, but the binding energy for $Cu(2P^3)$ level of reduced catalysts was lowered than that of calcined catalysts. The surface copper species which was in the maximum amount when the CuO:ZnO composition in the catalyst was 30:70, existed as zero valent copper. This result agreed with the experimental result that the highest rate of methanol formation was observed when the CuO content in the catalyst was 30%. It was postulated that these reduced catalysts performed with a relatively strong basicity because the formation rate of acetone was higher than that of propylene in isopropanol decomposition as measured in a pulse type reactor.

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Case Study of 4-Bar Linkage KAFO in Person With Poliomyelitis (소아마비에서 4절 연쇄 장하지보조기 사례연구)

  • Kim, Jang-Hwan;Kwon, Oh-Yun;Yi, Chung-Hwi;Cho, Sang-Hyun;Cynn, Heon-Seock;Choi, Heung-Sik
    • Physical Therapy Korea
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    • v.20 no.1
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    • pp.18-27
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    • 2013
  • The purpose of this study was to compare the ring lock type knee-ankle-foot orthosis (KAFO) with newly developed 4-bar linkage KAFO on the gait characteristics of persons with poliomyelitis clinically. This 4-bar linkage is the stance control type KAFO which provide the stability during stance phase and knee flexion during swing phase. Two subjects participated in this study voluntarily. We provided the customized 4-bar linkage KAFO then asked the subjects to walk in level surface and stairs under the two different KAFO conditions. The characteristics of gait in the persons with poliomyelitis were evaluated using a 3D motion analysis system and force plate. Additionally 6 minute walk test for physiological cost index were conducted using pulse oximeter to measure the energy consumption. In the results of this study, the differences of 4-bar linkage KAFO compared with ring lock type KAFO are as follows: (1) Walking speed, stride length, and step length on level increased in subjects, (2) The gait symmetry was improved by generated knee flexion and decreased pelvic external rotation on level and stairs walking, (3) Decreased vertical excursion of center of mass and pelvic elevation during swing phase was decreased on level, (4) Knee extension moment, hip flexion moment, hip and knee internal rotation moment of non-braced limb were decreased on level walking, (5) Walking speed in 6-minute walk test was increased and physiological cost index was decreased. These findings indicate that 4-bar linkage KAFO compared with ring lock type KAFO is effective in enhancing pattern, endurance, and energy consumption in level surface and stairs walking.

Study of Catalytic Filter on the Removal of Dust and HVOC (촉매필터를 이용한 먼지 및 HVOC 제거 특성 연구)

  • Jeong, Soon Kwan;Park, Young Ok
    • Applied Chemistry for Engineering
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    • v.19 no.1
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    • pp.80-85
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    • 2008
  • Catalytic filter is capable of performing shallow bed dust filtration plus a catalytic reaction, promoted by a catalyst deposited in its inner structure. Such a feature may allow potential cost and space reduction in several environmental applications. Dust filtration and halogenated volatile organic compound (1,2-dichlorobenzene) destruction were carried out in a lab-scale reactor. $WO_3-V_2O_5/TiO_2$ supplied by MaGreen, which showed high catalytic acitivity at low temperature, was used as a catalyst. P-84 that can be operated under $250^{\circ}C$ was used as a felt. The catalytic activity and filtration efficiency of catalytic filters were investigated under the operating conditions, including temperature, face velocity, and dust concentration. The catalytic activity of catalytic filter increased with increasing temperature and the amount of catalyst loaded. The test results showed that the filtration efficiency was primarily affected by the face velocity. Pressure drop variations as a function of time were investigated for a variety of conditions. In case of virgin filter, a dramatic decrease in the pulse interval and a slightly increase in the base line pressure drop were observed. A relatively slow pressure drop build-up was recorded for the catalytic filter due to smooth and slippery surface characteristics of nanofiber. The catalytic filter indicated that high filtration efficiency over 99.98% and high catalytic activity over 90% at 1 m/min and $210^{\circ}C$.

Inquiry on Post Surgery Induced Consumption in HyungSang Medicine View (각종 수술 후 유발되는 허로(虛勞)의 형상의학적 고찰)

  • Kim, Jong-Won;Ji, Gyu-Yong;Kim, Kyung-Chul;Lee, In-Sun;Kim, Hyung-Gyu;Lee, Yong-Tae
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.4
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    • pp.930-942
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    • 2008
  • Following conclusions were derived from researching various consumption caused after surgical operation. The meaning of surgery in HyungSang medical point of view is a big flaw of the original configuration. Therefore meaning, the loss of container to store something. Changes of the body after surgery can be formation of stagnated blood and abnormal cyst of the removed part and entangled undigested food and stagnant blood. After surgery when the symptoms become chronic or the patients develop side effects as they age, consumption and aging process begins. HyungSang medical treatments of consumption caused after surgery are the followings. We should prevent aging of the framework by using appropriate medication to make up for faults in Gall Bladder, Bladder type and six meridian type by considering its form, color, pulse and symptoms. Stability of emotion that can endure various mental stimulation is needed. Prevent stagnation, indigestion, obstruction and numbness by smoothing up the constructive energy and the defensive energy in the operated part. The Heart and Kidney should be under control and Stomach and Spleen should be reinforced so that food intake is accelerated and produce vital substances and Ki and blood. Eum blood and Yang Ki should circulate around the body well. Examine daily life and if small changes in skin complexion, appetite, sleep and excretion occur, also difference in adaptation of external stimulation and mental health occurs immediate treatment and care is necessary. Treatment of side-effects caused from both aging process and post-surgery in HyungSang's view point is considered better than other ways of treatment and will contribute in expanding the field of medical science.

Operatonal characteristics of the PLS linac vacuum system (PLS 선형가속기 진공계의 운전특성)

  • 김임경;박용정;김경렬;남궁원
    • Journal of the Korean Vacuum Society
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    • v.5 no.4
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    • pp.269-277
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    • 1996
  • The vacuum systems of PLS linac provides average pressure of $2.6\times 10^{-6}$Pa under high power microwave of 54 MW peak with 4.1 $\mu \textrm s$ pulse width and 10 Hz repetition rates. The base pressure of system is$2.4\times 10^{-6}$Pa with 45$^{\circ}C$ cooling water. The outgassing rate of the system is decreased from $3.0\times 10^{-11}Torr-l/sec-\textrm{cm}^2$ at the initial stage after installation to $1\times 10^{-12}Torr-l/sec-\textrm{cm}^2$ at present. Total accumulated microwave energy dose is about 140 GJ per module. All ion pumps are working under saturated regime and effective pumping speeds of 60 I/s, 230 I/s ion pumps are 45 I/s, 65 I/s, 140 I/s under the operating range. Main problems occurred in recent year are troubles of ion pump controller and vacuum gauge controller, vacuum leak of energy doubler window and electron gun ceramic, and water leak in the dummy load of acceleraing columns. Total of 41 troubles with 140. 8 hours down time give good system availability of 98%. Down time can be reduced by high power waveguide valves and water dummy loads under development, and then availability is expected to be increased up to 99.5%.

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The Conversion of Methane with Oxygenated Gases using Atmospheric Dielectric Barrier Discharge (배리어방전을 이용한 메탄전환반응에서 함산소 가스가 전환율 및 생성물변화에 미치는 영향)

  • Lee Kwang-Sik;Yeo Yeong-Koo;Choi Jae-Wook;Lee Hwa-Ung;Song Hyung-Keun;Na Byung-Ki
    • Journal of Energy Engineering
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    • v.15 no.1 s.45
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    • pp.52-59
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    • 2006
  • This paper examined the conversion of methane to hydrogen and other higher hydrocarbons using dielectric barrier discharge with AC pulse power. Two metal electrodes of a coaxial-type plasma reactor were separated by gas gap and an alumina tube. The inner electrode was located inside the alumina tube. The alumina tube was located inside the stainless steel tube, which was used as the outer electrode. Effect of feed gas composition (methane, oxygen, argon, water and helium), flow rate, applied frequency, input volt-age on methane conversion and product distribution were studied. The major products of plasma chemical reactions were ethylene, ethane, propane, buthane, hydrogen, carbon monoxide and carbon dioxide. The increment of applied voltage and the usage of inert gas as the background (helium and argon) enhanced the selectivity of hydrocarbons and methane conversion. The addition of water in the feed stream enhanced the conversion of methane and yield of hydrogen. Higher voltage leads to higher yield of $C_2H_6,\;C_3H_8,\;C_4H_{10}$ and yield or $C_2H_2\;and\;C_2H_4$ appeared highly in lower voltage.

Review of Failure Mechanisms on the Semiconductor Devices under Electromagnetic Pulses (고출력전자기파에 의한 반도체부품의 고장메커니즘 고찰)

  • Kim, Dongshin;Koo, Yong-Sung;Kim, Ju-Hee;Kang, Soyeon;Oh, Wonwook;Chan, Sung-Il
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.6
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    • pp.37-43
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    • 2017
  • This review investigates the basic principle of physical interactions and failure mechanisms introduced in the materials and inner parts of semiconducting components under electromagnetic pulses (EMPs). The transfer process of EMPs at the semiconducting component level can be explained based on three layer structures (air, dielectric, and conductor layers). The theoretically absorbed energy can be predicted by the complex reflection coefficient. The main failure mechanisms of semiconductor components are also described based on the Joule heating energy generated by the coupling between materials and the applied EMPs. Breakdown of the P-N junction, burnout of the circuit pattern in the semiconductor chip, and damage to connecting wires between the lead frame and semiconducting chips can result from dielectric heating and eddy current loss due to electric and magnetic fields. To summarize, the EMPs transferred to the semiconductor components interact with the chip material in a semiconductor, and dipolar polarization and ionic conduction happen at the same time. Destruction of the P-N junction can result from excessive reverse voltage. Further EMP research at the semiconducting component level is needed to improve the reliability and susceptibility of electric and electronic systems.

Improvement of Conductive Micro-pattern Fabrication using a LIFT Process (레이저 직접묘화법을 이용한 미세패턴 전도성 향상에 관한 연구)

  • Lee, Bong-Gu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.5
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    • pp.475-480
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    • 2017
  • In this paper, the conductivity of the fine pattern is improved in the insulating substrate by laser-induced forward transfer (LIFT) process. The high laser beam energy generated in conventional laser induced deposition processes induces problems such as low deposition density and oxidation of micro-patterns. These problems were improved by using a polymer coating layer for improved deposition accuracy and conductivity. Chromium and copper were used to deposit micro-patterns on silicon wafers. A multi-pulse laser beam was irradiated on a metal thin film to form a seed layer on an insulating substrate(SiO2) and electroless plating was applied on the seed layer to form a micro-pattern and structure. Irradiating the laser beam with multiple scanning method revealed that the energy of the laser beam improved the deposition density and the surface quality of the deposition layer and that the electric conductivity can be used as the microelectrode pattern. Measuring the resistivity after depositing the microelectrode by using the laser direct drawing method and electroless plating indicated that the resistivity of the microelectrode pattern was $6.4{\Omega}$, the resistance after plating was $2.6{\Omega}$, and the surface texture of the microelectrode pattern was uniformly deposited. Because the surface texture was uniform and densely deposited, the electrical conductivity was improved about three fold.

A comparative study on between Shanghanlun(傷寒論) and Sa-sang constitutional medicine(四象醫學) in Pathogenesis (상한론(傷寒論)과 사상의학(四象醫學)의 병기(病機)에 대한 비교연구(比較硏究) - 동의수세보원(東醫壽世保元) 변증론(辨證論)을 중심(中心)으로 -)

  • Lee, Kwang-Young;Park, Chan-Kuk
    • Journal of Korean Medical classics
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    • v.11 no.1
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    • pp.676-718
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    • 1998
  • After a comparative study on between Shanghanlun(傷寒論) and Sa-sang constitutional medicine(四象醫學) in Pathogenesis, I got a conclusion like this. Sa-sang consitutional medicine(四象醫學) changed the directions to the medicine in the center of personality from the medicine in the center of Shanghanlun(傷寒論)'s demonstration, devided the personality of people by the size of Organ system(臟腑) into 4types of Tae-eum, Yo-yang, Tae-yang, Yo-eum(太少陰陽), and explains all the course of physiology, pathology, diagnosis, therapy of the body on the point of constitutional view. Comparing the features of two medicines, Shanghanlun(傷寒論) and Sa-sang constitutional medicine(四象醫學), Shanghanlun(傷寒論) devided the diseases into the three type of eum-yang based on eight principal syndroms(八綱原理), in accordance with evidence of illness, pulse and studied the therapy, Shanghanlun(傷寒論) set up the basis of medicine which is based on overall of symptoms and signg(辨證論治醫學). Sa-sang constitutional medicine(四象醫學) distinguished the image(象) which is devided by the size of inherited Organ system(臟腑), refered to the symptom of diseases(病症) and decided the therapic directions. So Sa-sang constitutional medicine(四象醫學) gave more accuracy to the therapy by subdeviding the process of differenciation of case(辨證) into 2 steps of differenciation of image(辨象) and differenciation of case(辨證). In view of etiologic factor, Shanghanlun(傷寒論) regarded it as a invading of pathogenic factors(邪氣), so Shanghanlun(傷寒論) has the medical theory of pathogenic factors(邪氣). But Sa-sang constitutional medicine(四象醫學) regarded it as a disorder of the genuine energy(正氣)'s movements(升降緩速), so Sa-sang constitutional medicine(四象醫學) has the medical theory putting first of genuine energy(正氣). But Shanghanlun(傷寒論) also recognized the constitutional difference basically and Sa-sang consitutional medicine(四象醫學) devided the constitution into Tae-eum, Yo-yang, Tae-yang, Yo-eum(太少陰陽) and explained the food-air-fluid metabolism(飮食-氣液之氣病證) as cold-hot, cool-warm and devided the the symptom of diseases(病症) into the interior and the exterior(表裏) as the up-down, slow-fast movements of eum-yang and insufficiency and excessiveness is between them. In the end, Sa-sang constitutional medicine(四象醫學) has the theory of eight principal syndroms(八綱原理) faithfully which is the theory of differenciation of case(辨證理論) of Shanghanlun(傷寒論). Therefore Shanghanlun(傷寒論) made a lot of influence on originating Sa-sang constitutional medicine(四象醫學), Sa-sang constitutional medicine(四象醫學) is the theory which is based on existing medical theory including Shanghanlun(傷寒論) and composed the new medical theory to the constitutional point of view. Sa-sang constitutional medicine(四象醫學) enriched the medical theory and developed the clinical medicine so it has the historical value in the medicine.

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The Clinical Study on 40 Cases of Patient with Chronic Prostatitis (만성전립선염환자(慢性前立腺炎患者) 40예(例)에 대(對)한 임상적(臨床的) 고찰(考察))

  • Cho, Chung Sik;Kim, Chul Jung
    • Journal of Haehwa Medicine
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    • v.8 no.2
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    • pp.245-257
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    • 2000
  • A clinical study was done 40 patients of chronic prostatitis who was treated in Dept. of Internal Medicine, Oriental Medicine Hospital, Taejon University, from 1 Mar. 1999 to 31 Oct. 1999. The results were as follows. 1. In distribution of age, 30's and 40's were 57.5% the most, 20's and 60's were 35.0%, 50's was 7.5%. 2. In distribution of past history, the urethritis(45.0%) was the most. 3. In distribution of ocupation, a white-collar worker was 35.0%, a business man was 22.5%, a public servant was 12.5%, etc. 4. Sitting the mean time of day were distributed 5~7 hours, above 7 hours, 3~5 hours, under 3 hours, etc. 5. The resting interval of a long distance drive were distributed 2 hours(35.0%), 3 hours(32.5%), etc. 6. The habit of enduring ejaculation during sexual intercourse was showed 45.0%. 7. The habit of enduring urination was showed 20.0%. 8. Influency of mental stress was showed 90.0%. 9. Ten cases(25.0%) were showed riding horse or riding bicycle. 10. Four cases(10.0%) were showed wearing tight trousers. 11. The habit of put a wallet his hip pocket was showed 57.5%. 12. The most common symptom was distributed the others symp-tom(66.8%) and the voiding symptom(63.3%) more than pain-neuro-logical symptom(37.5%) and symptom related with sexual function (26.6%). 13. In distribution of palpation, lower abdominal pain, lumbar pain, perineal or parascrotal pain were mostly showed right side. Moreover diagnosis of pulsation was weakly showed chi pulse of right. 14. Duration of disease were distributed above 1 year(82.5%), under 1 year(17.5%). Degree of prostatitis was severe showed adove 1 year. 15. The distribution of WBC count of the prostatic secretion, com-paring with before therapy and after therapy, were showed from 5 cases to 0 case in very many/HPF, from 23 cases to 13 cases in many/HPF, from 12 cases to 13 cases in 10~30/HPF, from 0 case to 13 cases in under 10/HPF. 16. Therapeutic improvement of symptom were distributed pain-neurological symptom(94.8%), the others symptom(90.8%), the void-ing symptom(89.6%) and symptom related with sexual function(67.5%). 17. Differentiation of symptoms and signs were distributed dificiency of spleen-lung vital energy, wetness-heat of lower warmer, dificiency of spleen-kidney yang, dificiency of kidney yin, wetness-phlegm, dificiency of vital energy and blood. The prescriptions were Bojungikgitang(44.6%), Yukmijihwangtang(20.7%), Palmijihwangtang(12.0%), etc.

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