• Title/Summary/Keyword: Cold Former

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Quality of root canal fillings using three gutta-percha obturation techniques

  • Ho, Edith Siu Shan;Chang, Jeffrey Wen Wei;Cheung, Gary Shun Pan
    • Restorative Dentistry and Endodontics
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    • v.41 no.1
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    • pp.22-28
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    • 2016
  • Objectives: The goal of this study was to compare the density of gutta-percha root fillings obturated with the following techniques: cold lateral (CL) compaction, ultrasonic lateral (UL) compaction, and warm vertical (WV) compaction. Materials and Methods: Thirty-three extracted mandibular first molars, with two separate mesial canals in each, were selected. After instrumentation, the canals were stratified into three groups based on canal length and curvature, and underwent obturation with one of the techniques. No sealer was used in order to avoid masking any voids. The teeth were imaged pre- and post-obturation using micro-computed tomography. The reconstructed three-dimensional images were analyzed volumetrically to determine the amount of gutta-percha present in every 2 mm segment of the canal. P values < 0.05 were considered to indicate statistical significance. Results: The overall mean volume fraction of gutta-percha was $68.51{\pm}6.75%$ for CL, $86.56{\pm}5.00%$ for UL, and $88.91{\pm}5.16%$ for WV. Significant differences were found between CL and UL and between CL and WV (p < 0.05), but not between UL and WV (p = 0.526). The gutta-percha density of the roots treated with WV and UL increased towards the coronal aspect, but this trend was not noted in the CL group. Conclusions: WV compaction and UL compaction produced a significantly denser gutta-percha root filling than CL compaction. The density of gutta-percha was observed to increase towards the coronal aspect when the former two techniques were used.

Difference of Synoptic Characteristics according to the Persistence of Rainfall in Korea during the Changma Season (장마철 우리나라 강수의 지속성에 따른 종관 특성의 차이)

  • Park, Byong-Ik
    • Journal of the Korean Geographical Society
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    • v.45 no.6
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    • pp.748-765
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    • 2010
  • This study aims to investigate the difference of synoptic characteristics over East Asia according to the persistence of rainfall in Korea during the Changma season (June and July). In the cases of consecutive rainfall which lasts four or more days, there are developed ridges in 850hPa level east of the Korean peninsula which introduce stagnation of the synoptic cyclone over Korea. An cold area in 850hPa level moves southward from the Northern China in one day before the beginning the rainfall day in Korea and it aids the development of the stationary front in East Asia. When rainfall lasts a day or two, cyclones pass over Korea in rainy day and the stationary front in East Asia is not intensified. In both cases the synoptic cyclones near the Korean peninsula shows a deep-baroclinic structure, while in the former cases over the southwestern part of Japan a subtropical frontal zone which has a shallow structure appears near Japan. In latter cases the frontal structures are same near Korea and Japan. So, this means that the Changma is not necessarily similar to the Baiu of Japan in all cases.

A Study on Theoretical Background Relationship of Blood Vessel Pressure Massage and Skin and Management Method of Blood Vessel Pressure Massage for Skin Care (피부미용과 관련된 한방미용경락의 이론적 배정 연구)

  • Choi, Jong-Mi;La, Young-Sun
    • Journal of the Korean Society of Fashion and Beauty
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    • v.2 no.1 s.1
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    • pp.5-13
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    • 2004
  • This study was analyzed on relationship of blood vessel pressure massage and skin and management method on blood vessel pressure for skin care with Yin-yang 5 factors theory, Yin-yang 5 factors theory of blood vessel pressure massage with related Korean medicine is essential for descriptions of the physiology of human body and disease. Six elements(wind, heat, fire, dryness, wetness, and cold) and seven emotions(anger, happiness, thought, worry, sadness, surprise, and fear) effected on skin care and the five viscera and the six stomach. Blood vessel pressure massage related with skin consists of the five viscera and the six stomach and is improved blood circulation and is retarded aging of skin by controls of hormone and free nerve system. Blood vessel pressure massage for skin care improved in the intestine system and blood circulation and got healthy. The blood vessel pressure massage treatment of beauty art can aid the function of bio-rhythm of a human body and make our body health by healing the problems of the five viscera organs and the six stomach. It also help circulate of the blood flow and vigor. The study expects the related researches to improve the various treatments through this treatment. The researcher encountered many problems with the lack of concerned materials and former studies but expects this study to be a study to retard aging the skin and prevent the diseases through the study of the blood vessel pressure massage.

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An experimental study of particle deposition from high temperature gas-particle flows (고온의 기체 입자 유동으로부터 입자부착 현상에 관한 실험적 연구)

  • 김상수;김용진
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.11 no.3
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    • pp.501-508
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    • 1987
  • Experimental studies of particle (TiO$\_$2/) deposition from the laminar hot gas particle flow (about 1565K) onto the cold wall surface (about 1215K-1530K) were carried out by the 'real time' laser light reflectivity method (LLRM) and the photographs of scanning electron microscope(SEM). The LLRM was used for the measurement of thermophoretic deposition rates of small particles (d$\_$p/<3.mu.m), and the photographs of SEM were used for determining what factors control the collection of particles having diameters ranging from 0.2 to 30 microns. Two phenomena are primarily responsible for transport of the particles across the laminar boundary layers and deposition: (1) particle thermophoresis (i.e. particles migration down a temperature gradient), and (2) particle inertial impaction, the former effect being especially larger factor of the particle deposition in its size over the range of 0.2 to 1 microns. And also, this study indicates that thermophoresis can be important for particles as large as 15 microns. Beyond d$\_$p/=16.mu.m, this effect diminishes and the inertial impaction is taken into account as a dominant mechanism of particle deposition. The results of present experiments found to be in close agreement with existing theories.

A Study on The Performance of Ventilation and Maintaining Thermal Environment for a Combined Type Diffuser (급·배기 일체형 디퓨저의 환기 및 온열환경 유지성능에 대한 연구)

  • Lim, Seok-Young;Chang, Hyun-Jae
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.28 no.6
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    • pp.232-241
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    • 2016
  • Installing a ventilator for an apartment house composed of over 100 dwelling units was mandated in 2006 to improve indoor air quality. In the case of mechanical ventilators, the air change rate is kept stable, however 68% of dwellers do not operate their ventilator because of an increased electrical bill and noise. In the case of natural ventilators, the former problems are settled, but there are concerns about cold draught and an increase of heating/cooling cost. Authors are developing a heat recovery type natural ventilator which is a natural ventilator equipped with total heat recovery element, and it is expected that those problems of mechanical ventilator and natural ventilator are resolved by this. The combined type diffuser of this study is an under developed fit to the heat recovery type natural ventilator above. There are no standards to evaluate the performance for this type of diffuser. Due to this issue this study investigated the performance of the ventilation and maintained a thermal environment for the combined type diffuser by comparing it with existing diffusers. The results revealed that the performances of the combined type of diffusers showed different features from the existing ones, and was estimated to be high enough in the performances above.

Effects of Impeller Geometry on the 11α-Hydroxylation of Canrenone in Rushton Turbine-Stirred Tanks

  • Rong, Shaofeng;Tang, Xiaoqing;Guan, Shimin;Zhang, Botao;Li, Qianqian;Cai, Baoguo;Huang, Juan
    • Journal of Microbiology and Biotechnology
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    • v.31 no.6
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    • pp.890-901
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    • 2021
  • The 11α-hydroxylation of canrenone can be catalyzed by Aspergillus ochraceus in bioreactors, where the geometry of the impeller greatly influences the biotransformation. In this study, the effects of the blade number and impeller diameter of a Rushton turbine on the 11α-hydroxylation of canrenone were considered. The results of fermentation experiments using a 50 mm four-blade impeller showed that 3.40% and 11.43% increases in the conversion ratio were achieved by increasing the blade number and impeller diameter, respectively. However, with an impeller diameter of 60 mm, the conversion ratio with a six-blade impeller was 14.42% lower than that with a four-blade impeller. Data from cold model experiments with a large-diameter six-blade impeller indicated that the serious leakage of inclusions and a 22.08% enzyme activity retention led to a low conversion ratio. Numerical simulations suggested that there was good gas distribution and high fluid flow velocity when the fluid was stirred by large-diameter impellers, resulting in a high dissolved oxygen content and good bulk circulation, which positively affected hyphal growth and metabolism. However, a large-diameter six-blade impeller created overly high shear compared to a large-diameter four-blade impeller, thereby decreasing the conversion ratio. The average shear rates of the former and latter cases were 43.25 s-1 and 35.31 s-1, respectively. We therefore concluded that appropriate shear should be applied in the 11α-hydroxylation of canrenone. Overall, this study provides basic data for the scaled-up production of 11α-hydroxycanrenone.

Clinical Abdominal Examinations in Korean Medicine Based on Expert Opinions (한의 임상 복진법 - 전문가 의견을 바탕으로 -)

  • Kim, Keumji;Jeon, Hye-jin;Ko, Seok-jae;Park, Jae-Woo
    • The Journal of Internal Korean Medicine
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    • v.42 no.6
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    • pp.1211-1222
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    • 2021
  • Objectives: The purpose of this study was to investigate the opinions of experts on abdominal examinations in Korean Medicine included in the curriculum of the College of Korean Medicine. Methods: Among Korean doctors, 14 experts on abdominal examinations were interviewed; the experts included 9 professors of Korean internal medicine, 1 expert in diagnostics of Korean Medicine, 1 primary care Korean medicine doctor, and 3 executives of a (former) Korean association of the abdomen. The interview consisted of questions regarding recognition of the clinical importance of abdominal examinations, how to perform abdominal examinations, the most frequent abdominal examination findings encountered in clinical practice, and the definition of some of the abdominal examination findings. Results: Most interviewees recognized abdominal examinations as important and used them in clinical practice. Opinions on additions and corrections were collected regarding observation items, posture, method, and order during abdominal examinations. Abdominal examination findings that were common clinically were abdominal fullness (腹滿), epigastric stuffness (心下痞鞕), abdominal tenderness, epigastric fullness (心下滿), and rib distention (胸脇苦滿). The answers to the question related to the definitions of abdominal examination findings included consent and supplementary opinions regarding definitions of deficiency-excess, cold-heat, abdominal tenderness, tension of abdominal muscles, succession sounds, and borborygmus; these were mainly selected based on abdominal symptoms that are highly quantifiable. Conclusions: In the future, based on the results of this study, additional research related to the drafting of a standard abdominal examination in Korean medicine should be conducted to provide an opportunity to increase the reliability of Korean medicine diagnosis.

LOCA Analysis and Development of a Simple Computer Code for Refill-Phase Analysis (냉각재 상실사고 분석 및 재충진 단계해석용 전산코드 개발)

  • Ree, Hee-Do;Park, Goon-Cherl;Kim, Hyo-Jung;Kim, Jin-Soo
    • Nuclear Engineering and Technology
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    • v.18 no.3
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    • pp.200-208
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    • 1986
  • The loss of coolant accident based on a double-ended cold leg break is analyzed with the discharge coefficient (Ca) of 0.4. This analysis covers the whole transient period from the start of depressurization to the complete refilling of the core by using RELAP4/MOD6-EM and RELAP4/ MOD6-HOT CHANNEL for the system thermal-hydraulics and the fuel performance during the blowdown phase respectively, and RELAP4/MOD6-FLOOD and TOODEE2 during the reflood phase. A simple analytical method has been developed to account for the lower plenum filling by approximating steam-water countercurrent flows and superheated wall effects at the downcomer during the refill period. Based on the informations. at the time of EOB (end-of-bypass), the refill duration time and the initial reflooding temperature were estimated and compared with the results from the RELAP4/MOD6, resulting in a good agreement. In addition, some parametric studies on the EOB were performed. The form loss coefficient between upper head and upper downcomer was found to be sensitive to the occurrence of the spurious EOB. Appropriate form loss coefficients should be taken into account to avoid the flow oscillations at the downcomer. The analyses with the six and three volume core nodalizations, respectively, show much similar trends in the system thermal-hydraulic performance, but the former case is recommended to obtain good results.

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Study on Literatures of Symptoms and Signs of Tussiculaltion on Treatise on the Pathogenesis and Manifestations of All Diseases ("제병원후론(諸病源候論)" 중(中) "해수병제후(咳嗽病諸候)"에 대(對)한 연구(硏究))

  • Lee, Nam-Goo;Choi, Han-Baek;Kim, Jeong-Wan;Song, Min-A
    • Journal of Korean Medical classics
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    • v.23 no.5
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    • pp.11-22
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    • 2010
  • Treatise on the Pathogenesis and Manifestations of All Diseases(諸病源候論)was written by Chao Yuanfang that was most active during the Sui Dynasty at A.D. 610. It classified clinical medicine by some departments of internal medicine, surgery, obstetrics and gynecology, pediatrics, and otorhinolaryngology and within each specific department, categorizes etiology and pathology according to characteristics of various diseases. It was the total disease classification book that based on the bibles of the Oriental medicine, (Huangdi''s) Internal Classic(黃帝內經), Classic of Difficult Issues(難經) and Treatise on Cold Damage and Miscellaneous Diseases(傷寒雜病論), A-B Classic of Acupuncture and Moxibustion(鍼灸甲乙經), Essential Prescriptions Worth a Thousand Gold for Emergencies(備急千金要方) and Medical Secrets of an Official(外臺秘要). It was arranged tussive causes, classes, diagnosis, prognosis and stretching for treatment by Volume 13, all symptoms of tussiculation. Dialectic part was divided into cough(咳嗽), cough with dyspnea(咳逆上氣), cough with pus and blood(咳嗽吐膿血), cough with duck crying sound(?嗽), sudden cough(暴氣咳嗽), cough with dyspnea(咳逆), cough with dyspnea and vomiting(咳逆上氣嘔吐). Disease situation part was divided into the new cough(新咳) and old cough(舊咳), deficiency syndrome(虛證) and excess syndrome(實證), visceral cough(藏府咳), etc. Out of these, cough with counterflow(咳嗽上氣), cough with dyspnea(咳逆上氣), cough with dyspnea and vomiting(咳逆上氣嘔吐), cough with shortness of breath(咳逆短氣) have a close connection with dyspnea(上氣), counterflow of qi(逆氣), dyspnea and vomiting(上氣嘔吐) and shortness of breath(短氣) in the Pathogenesis and Manifestations of All qi(氣病諸候) of vol 13. So two parts may be refer to each other. However, the content on the original book has been addition and subtraction on the original context along with many reprints. Therefore, this paper, with regard to the prints of former editions, tried to help in better comprehension of the original context through readings and Korean translation.

Clinical Aspects among Platers (도금공(鍍金工)에 대한 임상적(臨床的) 관찰(觀察))

  • Kim, Doo-Hie
    • Journal of Preventive Medicine and Public Health
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    • v.10 no.1
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    • pp.16-24
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    • 1977
  • This is a result of clinical examination for workers working with Chromic acid and Chromium compounds in the plating room of their companies. I selected two companies that the plating process and the kinds of plating were similar. One (SW Co.) was more or less improved the operating environment with the ventilation machine so on and another (SR Co.) did not it so. The former was examined at March 29th 1977, the latter was at June 28th 1976. But the respiratory communicable diseases, flue or common cold so on were not spreaded there at that time. The clinical aspects were compared between the group of SW, and SR. The swelling and hyperemic signs of nasal mucous membrane and the experience of nasal bleeding were about 50%, generally, in all the groups. The following problem was dizziness or vertigo. The nasal signs in the group of SW (improved ventilation of the room air) were relatively weak, but in another, it was some what severe; - there was necrotic sign with thick nasal clast. They were only used of gauze mask when the vapors of various solvents were deeply full in the room. And there was very high rate of bronchial signs, sputum or coughing in the group of SW improved ventilation so called, than another one. I suppose that it means chronic inflammatory change of the bronchial mucous membrane with deeper signs, due to the individual protectors were carelessly or not used according to the improving of the operating environment. Theses nasal signs mentioned the above were not nearly in the other groups had not been done the Chromium plating. The Status of RBC, Hb and Ht, of urine protein and urobilinogen were mostly in normal range. But the number of WBC was more or less showed with a positive correlation to the working duration.

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