• Title/Summary/Keyword: disc

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Study on the development of preventive agent of dental caries from biological active materials Development of disc PAHA for an artificial tooth and preventive effect on dental caries from plant extracts (생물학적 활성물질에서 치아우식 예방제 개발에 관한 연구 I. 인조치아 disc PAHA의 제조 및 식물추출물들의 치아우식 예방효과)

  • 이기용;조효상윤정원허태련
    • KSBB Journal
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    • v.8 no.2
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    • pp.126-132
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    • 1993
  • The objective of this study was to develop an artificial dentin for easy handle and accurate observation of the mechanism on dental caries and to screen biologically active materials from the extracts of traditional plants and fruits for prevention of early dental cares. In order to produce disc PAHA (artificial dentin), the powdered hydroxylapatite was immobilized in a 20% polyacrylamide gel. The characteristics of disc PAHA was very similar to the surface, figure and lattice of human enamel. After decalcification in 0.1M citric acid based on observation with SEM. The critical point of decalcification of disc PAHA by acids was found to be pH 5.0-5.5, which was hi agreement with human enamel. The degree of decalcification from disc PAHA in 0.1M citric acid solution was sixfold higher than that of human enamel. This result suggested that disc PAHA would be useful as a substitute of human enamel for in vitro experiment. The extracts of garlic and Flower Apple A, B seemed to inhibit growth of S. mutans. Especially, when the 300$\mu\ell$ of its extracts added to the medium to incubate S. mutans, F. apple B showed strongly an inhibitory effect in both the growth of S. mutans and the synthesis of insoluble glucan.

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The Clinical Analysis on 32 Cases of Herniated Lumbar Disc Patients according to Lumbar CT scan. (Lumbar Spine CT 촬영한 요각통 환자 32례의 치료경과 분석)

  • Kim, Jeong-Ho;Lee, Jeong-Hwan;Kim, Young-Il
    • Journal of Pharmacopuncture
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    • v.13 no.2
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    • pp.111-120
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    • 2010
  • Objective: This study is to evaluate the effectiveness of the oriental medicine treatment on lumbar disc herniation. Subjects and Methods : The clinical analysis was done on 32 cases of patients with lumbar disc herniation diagnosed by lumbar CT scan. Patients who admitted In Cheongju Oriental Medicine Hospital from April 2007 to April 2008 were analyzed according to the distribution of sex, age, the period of disease, condition on admission, the symptom on admission, Admission day, the treatment efficacy at discharge day. Results : 1. The forties was the most, the acutest phase the most, the day of 8-14 days the most. 2. Multiple bulging disc in 37.5% of CT scan was the most common, followed by a single HNP was 28.1%. 3. Almost 81 % patients showed effective efficacy under VAS 3 at discharge day. 4. Single bulging and herniated disc were more short admission days than multiple bulging and herniated disc.

An Experimental Study on Brake Judder of Braking on Vehicle (실차 상태에서의 제동시 이상떨림 현상에 관한 실험적 연구)

  • Hong, Il-Min;Lee, Won-Sub;Lee, Jong-Soo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.5
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    • pp.338-345
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    • 2002
  • The study presents a new testing and analysis method for brake judder on vehicle. For the identification of the excitation mechanism of a brake judder, it is necessary to measure the dynamic brake disc geometry during braking on vehicle. The non-contact sensor system was used to monitor the brake disc geometry. Brake torque variation (BTV) caused by disc thickness variation (DTV) is the primary excitation for brake judder. The mechanical effects generating BTV are linked not only to initial manufacturing tolerances but also to uneven wear. Therefore, the brake disc geometry should be strictly managed to initial condition. The aim of this study has been to measure the dynamic DTV and runout on vehicle and analyze the influence of test parameters on brake judder and compare the disc component with vehicle matching about the DTV Profile. As a result of this study, The amplitude of brake judder is proportional to vehicle speed and fluid pressure fluctuation on braking. The major sources of brake judder are directly related to disc thickness variation and side runout variation of corner assembly (disc, hub. bearing).

Study on the Conservative Treatment of Herniated Lumbar Intervertebral Disc (요추 추간판탈출증의 보존적 치료에 관한 연구)

  • Song, Bong-Keun
    • The Journal of Korean Medicine
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    • v.16 no.2 s.30
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    • pp.62-78
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    • 1995
  • In industrialized countries, low back pam is very common, with up to 60 to 80% of the population being affected at some time in their lives. Herniated lumbar intervertebral disc is one of principal cause of low back pain and radiculopathy. The therapy of the disease is classified into conservative treatment or surgical intervention. The majority of these cases successfully heal with conservative managemant, even though it was claimed that the henirated disc material would not resolved spontaneously without surgical removal. It was reported that there was no significant difference in outcome and cost effectiveness between conservative and surgical therapy group. Also after conservative therapy the resorption of herniated disc with satisfactory improvement of symptom was reported. Conservative treatment includes bed rest, heat, drug therapy, therapeutic exercises, physical therapy such as traction and manipulation, and acupuncture. These managements show favorable outcome in the patients with herniated lumbar intervertebral disc. So conservative management should be applied in the therapy of herniated intervertebral disc, unless there exist aggravation during the first 3 weeks of treatment or apparent surgical care indication. And further investigation to improve effectiveness of conservative therapy should be ensued.

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Solid Core Suspension Disc Insulators Preventing Puncture Caused by Steep Front Surge Voltage

  • Sangkasaad, Samruay
    • KIEE International Transactions on Electrophysics and Applications
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    • v.3C no.5
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    • pp.165-170
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    • 2003
  • This paper presents development of solid core suspension disc insulators (cap and cap suspension disc insulator) for replacing cap and pin suspension disc insulators in overhead transmission and distribution lines which expose to lightning discharges. By this means the punctured problem caused by steep front surge voltage created by lightning discharge on the lines can be solved. The solid core suspension insulator was designed and constructed based on the dimensions of conventional suspension disc insulators (cap and pin insulators). The insulators are made of alumina porcelain. The electrical and mechanical characteristics of the solid core suspension insulators were carried out. The puncture test was performed in the air by applying steep front impulse voltage with amplitude about 2.5 per unit of 50% flashover (CFO) of the insulator unit at negative standard lightning impulse $1.2/50\;\mu\textrm{s}$ with steepness up to $9200\;kV/\mu\textrm{s}$. The testing results show that solid core suspension disc insulators are not punctured eventhough the steepness of the steep front impulse voltage was increased up to $9200\;kV/\mu\textrm{s}$.

Clinical Studies on Ruptured Intervertebral Lumbar Discs (파열형(破裂型) 요추간판탈출증(腰椎間板脫出症)에 대한임상적(臨床的) 연구(硏究))

  • Sin Min-Seop;Roh Jeong-Du;Choi Seok-Woo;Lee Dong-Ho;Song Bum-Yong;Yook Tae-Han
    • Journal of Acupuncture Research
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    • v.18 no.6
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    • pp.84-92
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    • 2001
  • Objectives : We defined that the ruptured disc is extruded trans ligamentous through the posterior longitudinal ligament or sequestrated. The authors have experienced 12 cases of ruptured disc that underwent the conservative treatment. We studied the effect and possibility of the conservative treatment for the ruptured disc. Methods : The patients with ruptured disc have underwent the conservative treatment. After the treatment, we compare pre-treatment with post treatment in the view of state of patients' ambulation and physical conditions. Results : In this study, 12 cases of ruptured disc have underwent the conservative oriental treatment. After the treatment, 75% of the cases were improved above good state Conclusion : The ruptured disc has been operated universally. Except the emergency state, the conservative treatment is helpful to improve the symptoms of the patients with ruptured disc.

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Biomechanical Characteristics of Cervical Spine After Total Disc Replacement (인공 추간판 치환술 후 경추의 생체역학적 특성)

  • Park, Won-Man;Joo, Jeung-Woo;Kim, Kyung-Soo;Lee, Ki-Seok;Kim, Yoon-Hyuk
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.7
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    • pp.637-644
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    • 2009
  • We have analyzed the biomechanical characteristics of cervical spine after total disc replacement using finite element analysis. A finite element model of C2-C7 spinal motion segment was developed and validated by other experimental studies. Two types of artificial discs, semi-constraint and un-constraint, were inserted at C6-C7 segments. Inferior plane of C7 vertebra was fixed and 1Nm of moment were applied on superior plane of C2 vertebra with 50N of compressive load along follower load direction. Mobility of the cervical spine in which each artificial disc inserted was higher than that of intact one in all loading conditions. Also, high mobility at the surgical level after total disc replacement could lead higher facet joint force and ligaments axial stresses. The results of present study could be used to evaluate surgical option and validate the biomechanical characteristics of the implant in total disc replacement in cervical spine.

Pneumatic Test Assessment of Pulse Separation Device for Multi-Pulse Rocket Motor (다중펄스 로켓모타 적용 펄스분리장치의 공압시험평가)

  • Lee, Dong-Won;Lee, Won-Bok;Kang, Seong-Yeop;Lee, Jong-Won;Chang, Hong-Been
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.05a
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    • pp.101-104
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    • 2010
  • A bulkhead-type pulse separation device has been developed for the multi-pulse rocket motor. The design parameters of the pulse separation device were the shape of the rupture disc slit, welding conditions, and the implementation of the seal disc. The pneumatic tests of the fabricated pulse separation devices showed that the rupture pressure increased as the quantity of the rupture disc slit and welding strength increased and the seal disc was implemented.

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Shape Design based on Topology Optimization for Manufacturing of Lightweight Valve Disc by 3-D Printing (3차원 프린팅에 의한 경량 밸브 디스크 제조를 위한 위상최적화 기반의 형상 설계)

  • Kim, Taehyung
    • Journal of Energy Engineering
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    • v.27 no.4
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    • pp.13-19
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    • 2018
  • In this study, the lightweight design of butterfly valve disc component for power plant based on topology optimization was performed. Here, commercial finite element (FE) analysis software was used. The external shape of the basic disc model was not deformed, and the internal element density was removed to make it lightweight. Optimal design was performed each other after the disc plate and two brackets attached on the surface of the disc were separated. Once the optimal shapes were selected, they were assembled to build up the 3-D lightweight valve disc model. After applying pressure to this model, FE analysis was performed to confirm the structural safety.

Major Satisfaction and Professionalism according to DISC Behavior Patterns of Dental Hygiene Students

  • Yoon, Sun-Joo;Moon, Kyung-Hui
    • International Journal of Clinical Preventive Dentistry
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    • v.14 no.4
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    • pp.241-246
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    • 2018
  • Objective: This study was performed to verify how DISC behavior patterns affect the major satisfaction and professionalism of dental hygiene students and provide basic data for dental hygiene students to have increased major satisfaction and maximize their strength by understanding their DISC behavior pattern. As a result, the following conclusion was obtained. Methods: The data was collected From November 1, 2018 to November 14, 2018, 218 dental hygiene students. Data was collected using self-reported questionnaires. Statistical analysis was performed with IBM SPSS ver. 21.0. Mean (standard deviation) and one-way ANOVA & pearson correlation were performed. Results: The most frequent DISC behavior patterns of dental hygiene students was steadiness types (49.0%) followed by influence types (34.5%), conscientiousness types (9.0%), and dominance types (7.5%). There were no significant difference in professionalism and major satisfaction according to DISC behavior patterns in dental hygiene students. There was a correlation between major satisfaction and professionalism of dental hygiene students. Conclusion: In conclusion, in order for dental hygiene students to establish positive professionalism through increased major satisfaction, it is necessary to make various efforts such as providing consultation and education that corresponds to each student's DISC behavior patterns. These efforts will provide the students career vision and encourage them to improve their academic achievement and find employment that fits their vocational aptitude.