• Title/Summary/Keyword: primary phase

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Preparation of GdBCO Thin Film by Ex-situ Process using Nitrate Precursors (질산염 전구체 원료로 Ex-situ 공정에 의한 GdBCO 박막 제조)

  • Kim, Byeong-Joo;Lee, Chul-Sun;Lee, Jong-Beom;Lee, Jae-Hun;Moon, Seung-Hyun;Lee, Hee-Gyoun;Hong, Gye-Won
    • Progress in Superconductivity
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    • v.13 no.2
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    • pp.127-132
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    • 2011
  • Many research groups have been manufacturing coated conductor by various processes such as PLD, MOD, and MOCVD, but the methods with production cost suitable for wide and massive application of coated conductor did not develop yet. Spray pyrolysis method adopting ultrasonic atomization was tried as one of the possible option. GdBCO precursor films have been deposited on IBAD substrate by spray pyrolysis method at low temperature and converted to GdBCO by post heat treatment. Ultrasonic atomization was used to generate fine droplets from precursor solution of Gd, Ba, and Cu nitrate dissolved in water. Primary GdBCO films were deposited at $500^{\circ}C$ and oxygen partial pressure of 1 torr. After that, the films were converted at various temperatures and low oxygen partial pressures. C-Axis oriented films were obtained IBAD substrates at conversion temperature of around $870^{\circ}C$ and oxygen partial pressures of 500 mtorr ~ 1 torr in a vacuum. Thick c-axis epitaxial film with the thickness of 0.4 ~ 0.5 ${\mu}m$ was obtained on IBAD substrate. C-axis epitaxial GdBCO films were successfully prepared by ex-situ methods using nitrate precursors on IBAD metal substrate. Converted GdBCO films have very dense microstructures with good grain connectivity. EDS composition analysis of the film showed a number of Cu-rich phase in surface. The precursor solution having high copper concent with the composition of Gd : Ba : Cu = 1 : 2 : 4 showed the better grain connectivity and electrical conductivity.

The Continuum of Rehabilitation Care and the Rehabilitation Services that are Needed by People with Severe Disabilities (재가 중증 장애인의 지속적 재활 관리 실태와 재활 서비스 요구)

  • Jang, Soong-Nang;Kim, Wan-Ho;Lee, Kyu-Beom;Kim, Su-Kyung;Lim, Jae-Young;Rhee, Seon-Ja
    • Journal of Preventive Medicine and Public Health
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    • v.39 no.3
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    • pp.263-269
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    • 2006
  • Objectives: As the number of people with disabilities is increasing and their needs for care are varied, the continuum and comprehensiveness of their rehabilitative care are getting more important. This study was performed to understand the utilization of rehabilitation services and requirements of care among the people with severe disabilities in Korea. Methods: We interviewed 578 disabled persons who had severe extremity and cerebral impairment in the urban and rural areas of Korea. The questionnaire included questions on their general characteristics, the type of disability, their physical function (ADL, IADL), their use of rehabilitation services after discharge and their requirements for rehabilitation care Results: Only 12.6% of people with disability in the community continuously used the available medical rehabilitation care. The associated factors for utilization of rehabilitation services were pain and admission for rehabilitative treatment in the acute phase. There was a great need for rehabilitation services in community and this varied according to gender, the socio-economic status, the functional status and the geographic region. The gap between utilization and need for rehabilitation services was largest in the economic support. The gap of primary health care was larger in the rural area than in the urban area. Conclusions: The needs for rehabilitation service were diverse according to the individual functional status, the regional characteristics and other general characteristics of people with disability. Strategies should be considered to eliminate the barriers to obtain rehabilitation services for the people with disability in the community.

Partial Discharge Characteristics of Epoxy for Ignition Coil (점화코일용 에폭시의 부분방전 특성)

  • Shin Jong-Yeol;Hong Jin-Woong
    • Journal of the Korean Society of Safety
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    • v.19 no.4 s.68
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    • pp.141-149
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    • 2004
  • The automobile equipped with a gasoline engine uses the ignition coil, namely, a high voltage generator, to make the mixed fuel ignited and burned in the combustion chamber, which results in the power to drive the engine. The ignition coil functions to convert a low voltage of the primary into a hiか voltage of the secondary by switching method, which will be transmitted to the electrode. Here, if the ignition coil has a defect even a little, it cannot function well. In this study, it was chosen epoxy molding ignition coil in recently and epoxy resin which is insulation material as specimens, and it was measured the characteristics of the partial discharge occurring to the specimens when those were applied to a voltage, and thereby, it was researched and analyzed the distribution of phase angle, amount and count of discharge due to the changing voltage, And as the result is applying to the actual automobile ignition system, it can be expected the enhancement of the performance of the ignition coil and the reliability of the electrical equipment.

Experimental investigation on small scale siphon breaker (소규모 사이펀 차단기에 대한 실험적 연구)

  • Ji, Dae-Yun;Kim, Sung hoon;Lee, Kwon-Yeong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.5
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    • pp.1-8
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    • 2018
  • In this study, a small-scale siphon breaker experimental facility was designed to examine the validity of the Siphon Breaker Simulation Program (SBSP). To design the experimental facility, the simulation results of the C factor, Chisholm B coefficient, and Undershooting Height (UH) were obtained by SBSP. The major parts of the experimental facility were the upper tank, lower tank, downcomer, and Siphon Breaker Line (SBL). The area of the Upper tank was $0.09-m^2$ with a height of 0.65-m. The height of the downcomer was 1.6-m. Pressure transmitters and an electronic scale were used to obtain the experimental results. The experimental variables were the sizes of Loss of Coolant Accident (LOCA) and SBL. The experimental results were analyzed by UH. The SBSP well predicted the UH with an error of 2.5%. Overall, it is possible to design siphon breakers with various scales using SBSP.

Roles of Valproic Acid in Improving Radiation Therapy for Glioblastoma: a Review of Literature Focusing on Clinical Evidence

  • Ochiai, Satoru;Nomoto, Yoshihito;Yamashita, Yasufumi;Watanabe, Yui;Toyomasu, Yutaka;Kawamura, Tomoko;Takada, Akinori;Ii, Noriko;Kobayashi, Shigeki;Sakuma, Hajime
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.2
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    • pp.463-466
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    • 2016
  • Glioblastoma (GBM) is the most common and aggressive type of primary brain neoplasm. The current standard therapy for GBM consists of maximal surgical resection within safe limits, followed by radiation therapy (RT) and chemotherapy with temozolomide. Despite advances in treatment, the prognosis of GBM remains poor. Epileptic seizure is one of the most common symptoms in patients with GBM. Valproic acid (VPA), a histone deacetylase inhibitor, is often used as an anti-epileptic drug in patients with brain neoplasms due to its effectiveness and low toxicity profile. Several in vivo and in vitro studies have indicated that VPA has radiosensitizing effects for gliomas and radioprotective influence on normal brain tissue or hippocampal neurons. The results of several retrospective studies have also indicated potential benefit to improve survival of patients with GBM. Moreover, the promising treatment results of a phase 2 trial of concurrent radiation therapy, temozolomide, and VPA for patients with GBM have been recently reported. The use of VPA in patients with GBM has thus recently receiving more attention. In this article, we review the role of VPA in radiation therapy for GBM, focusing on the clinical evidence.

Perioperative Comprehensive Supportive Care Interventions for Chinese Patients with Esophageal Carcinoma: a Prospective Study

  • Zhang, Xiao-Dan;Zhao, Qing-Yu;Fang, Yi;Chen, Guan-Xuan;Zhang, Hui-Fang;Zhang, Wen-Xiao;Yang, Xiao-Ping
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.12
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    • pp.7359-7366
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    • 2013
  • Objective: To assess the effects of perioperative comprehensive supportive care interventions on outcome of Chinese esophageal cancer patients in a prospective study. Methods: 60 patients with primary esophageal carcinoma were randomized into an intervention group (IG, n=31) and a control group (CG, n=29). The Chinese version of symptom checklist-90 (SCL-90) was adopted to assess their psychological status. The interventions, including health education, psychological support, stress management, coping strategies and behavior training, were carried out in 3 phases (preoperative, postoperative I and postoperative II), and psychological effects were thereafter evaluated accordingly before surgery, and 1 week, 4 weeks and 24 weeks post-surgery. Medical costs were estimated at discharge. Survival of patients was estimated each year post-surgery. General health status and satisfaction-with-hospital were surveyed by a follow-up questionnaire 4 years post-surgery. Results: All the subjects demonstrated higher scores in the preoperative phase than the normal range of Chinese population concerning 7 psychological domains including somatization, obsessive-compulsive, depression, anxiety, hostility, phobic anxiety and paranoid ideation. Although no significant difference was observed between the two groups at admission, the scores of IG, which tended to decrease at a faster rate, were generally lower than those of CG at weeks 1, 4 and 24 post-surgery. The length of hospital stay and medical costs of IG were significantly less than those of CG and satisfaction-with-hospital was better. However, there was no significant difference in 4-year survival or health status between two groups. Conclusions: Appropriate perioperative comprehensive supportive care interventions help to improve the psychological state of Chinese patients with esophageal carcinoma, to reduce health care costs and to promote satisfaction of patients and their families with hospital.

Influence of Injection Temperature on the Structure of Carbon Nanotubes Synthesized by Floating Catalyst Method (주입온도가 Floating Catalyst 법으로 합성한 탄소나노튜브의 구조에 미치는 영향)

  • Kang, Eun-Jin;Moon, Seung-Hwan;Lim, Jae-Seok;Hahm, Hyun-Sik;Park, Hong-Soo;Lim, Yun-Soo;Kim, Myung-Soo
    • Journal of the Korean Applied Science and Technology
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    • v.21 no.3
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    • pp.214-224
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    • 2004
  • Although the structure of carbon nanotubes is important factor characterizing its properties, it is very difficult to control the structure of carbon nanotubes (MWNTs) and to predict the range of their diameter, which is the primary factor of MWNTs' physical properties. We tried to control the diameter of MWNTsby governing the feed injection temperature of floating catalyst method. The structure of MWNTs was influenced by the phase change of ferrocene fed as the catalyst,. The carbon nanotubes were very narrow at injection temperatures close to the sublimation pt. of ferrocene, in which most MWNTs had diameters in the range of 20$^{\sim}$30 nm. At injection temperatures between the boiling pt. and melting pt. of ferrocene, the diameters became larger and had broad distribution. However, at injection temperatures higher than the boiling pt., the diameters became narrow again and had very uniform distribution.

Low frequency Instability in Hybrid Rocket Post-chamber Configuration (연소실 형상 변화에 의한 하이브리드 로켓의 저주파수 연소불안정)

  • Park, Kyungsu;Lee, Changjin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.42 no.1
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    • pp.29-36
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    • 2014
  • Hybrid rocket displays many different low frequency pressure oscillations during combustion. Thermal lag between solid and gas phase is the primary mechanism to trigger low frequency pressure oscillations of around 10Hz, and Helmholtz or $L^*$ mode also produces other types of low frequency oscillations above 10 Hz which is associated with the change in combustion volume. Since the flow characteristics in hybrid rocket is very similar to those in solid rocket combustion, it is not surprising to observe similar pressure oscillation behaviors. Experimental test shows that combustion pressure suddenly turns into to a big amplitude oscillation around 10Hz then followed by returning to an original pressure level after a short period combustion. Further investigations show that this instability is independent of the change in O/F ratio at all. One of the possible candidates is the vortex shedding dynamics over the backward step in the post combustion chamber. It is required to investigate the low frequency oscillation mechanism in the future study.

Mass Memory Operation for Telemetry Processing of LEO Satellite (저궤도위성 원격측정 데이터 처리를 위한 대용량 메모리 운용)

  • Chae, Dong-Seok;Yang, Seung-Eun;Cheon, Yee-Jin
    • Aerospace Engineering and Technology
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    • v.11 no.2
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    • pp.73-79
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    • 2012
  • Because the contact time between satellite and ground station is very limited in LEO (Low Earth Orbit) satellite, all telemetry data generated on spacecraft bus are stored in a mass memory and downlinked to the ground together with real time data during the contact time. The mass memory is initialized in the first system initialization phase and the page status of each memory block is generated step by step. After the completion of the system initialization, the telemetry data are continuously stored and the stored data are played back to the ground by command. And the memory scrubbing is periodically performed for correction of single bit error which can be generated on harsh space environment. This paper introduces the mass memory operation method for telemetry processing of LEO satellite. It includes a general mass memory data structure, the methods of mass memory initialization, scrubbing, data storage and downlink, and mass memory management of primary and redundant mass memory.

Effectiveness of SPACE Instructional Strategies for the Conceptual Change of the Elementary School children on Evaporation and Condensation (SPACE 수업 전략이 국민 학교 아동들의 증발과 응결 개념 변화에 미치는 영향)

  • Choi, Byung-Soon;Kim, Hyo-Nam;Kang, Soon-Hee;Kim, Young-Jun
    • Journal of The Korean Association For Science Education
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    • v.14 no.3
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    • pp.272-284
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    • 1994
  • The aim of this research was to compare and analyze the children's ideas on evaporation and condensation between pre- and post-intervention. Forty-eight children from six elementary schools in Seoul and Kyung Ki provinces were sampled by stratified random sampling. A set of structured activities was then provided which allow children to explore evaporation and condensation phenomena. All of these activities had a preliminary phase which required the child to predict or speculate on evaporation and condensation using their existing knowledge. These structured activities on evaporation and condensation were reviewed by three professors and eigth primary school teachers. Their comments were used to revise the original contents of the structured activities. The data analysed were gathered by the questionaire and the interview. Pre- and post-intervention data related to evaporation and condensation were collected by the same teacher, and analysed into the same category scheme. Data coding was carried out several times by the researcher to ensure reliablity. Data collected were then classified and analyzed according to the types of children's ideas. The findings of this study were as follows: Results of this study showed that the the vocabulary used to describe the evaporation phenomena varied according to the context, and the scientific term "evaporated" was more frequently used by the older children after post-intervention. But everyday terms such as"dried up","disappered", "gone up" were also used by children as much as the level of pre-intervention. Scientific conception on the location of evaporated water, the factor of evaporation, the ideas about getting the water back and assumption about the physical state of the missing water has been increased for the most of the children after intervention. It was found that the intervention using was effective SPACE strategies regardless of the grade level of the children.

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