• 제목/요약/키워드: Normal tension

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철근콘크리트 판넬의 인장강화효과 (Tension Stiffening Effect in Reinforced Concrete Panels)

  • 곽효경;김도연
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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    • pp.141-148
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    • 1998
  • An analytical model which can simulate the post-cracking behavior of reinforced concrete structures subjected to in-plane shear and normal stresses is presented. Based on the force equilibriums, compatibility conditions, and bond stress-slip relationship between steel and concrete, a criterion to simulate consider the tension-stiffening effect is proposed. The material behavior of concrete is described by an orthotropic constitutive model, and focused on the tension-compression region with tension-stiffening and compression softening effects defining equivalent uniaxial relations in the axes of orthotropy. Correlation studies between analytical results and available experimental data are conducted with the objective to establish the validity of the proposed model.

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실험적 당뇨 백서에서 교정력에 의한 치조골의 Cyclic AMP의 변화에 관한 연구 (A STUDY ON THE CYCLIC AMP IN THE ALVEOLAR BONE OF RATS APPLIED BY ORTHODONTIC FORCES IN EXPERIMENTAL DIABETES AND INSULIN TREATMENT)

  • 백일수;손병화
    • 대한치과교정학회지
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    • 제16권2호
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    • pp.53-67
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    • 1986
  • The physical tooth movement by orthodontic force is based upon alveolar bone resorption at compression site and new bone formation at tension site of the alveolar socket. The function of the cyclic AMP is to participate not only in initial action of bone cells by mechanical forces but also in the continuous cellular response leading to bone remodelling. This experiment was performed to clarify the role of cyclic AMP in bone remodelling by mechanical force in the NORMAL group, the DIABETES group and the INSULIN TREATED group. The 72 rats were divided into the NORMAL group, the DIABETES group and the INSULIN TREATED group. The same orthodontic forces were applied to the rats of 3 groups. These rats were treated for periods of time ranging from 1 hour, 1 day, 7 days, 14 days, 21 days and 28 days. The samples of alveolar bones were obtained from compression and tension sites surrounding the tipping teeth from NORMAL, DIABETE and INSULIN TREATED rats. The samples were assayed for cyclic AMP by the cyclic AMP RIA kit. The results were as follows: 1. The cyclic AMP levels of alveolar bone in compression and tension sites showed initial decrease, then increased and .remained elevated by the time consuming. 2. The highest cyclic AMP level showed in the DIABETES group and the lowest level was in the NORMAL group. 3. The cyclic AMP levels in the INSULIN TREATED group was similar with the NORMAL group in control and tension sites, but in the compression sites it was similar with the DIABETES group.

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정상으로 보이는 후두에서 음성변화의 감별진단 (Differential Diagnosis of Dysphonia Looks Normal Larynx)

  • 손호진;최승호
    • 대한후두음성언어의학회지
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    • 제27권2호
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    • pp.91-94
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    • 2016
  • Voice is a physical phenomenon, generated by vocal fold and expiratory airflow. Dysphonia should come from abnormal vocal fold and airflow. Occassionally larynx looks normal in show, but it is actually not. There should be undetected structural or functional abnormalities. So when ENT doctors face dysphonia patients who looks normal larynx, should make a diagnosis through close observation. In this review article we present some dysphonia diseases which looks normal larynx. For example vocal fatigue, vocal fold paresis, posterior glottic diastasis, muscle tension dysphonia and psychogenic dysphonia.

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감속 스텝모터를 이용한 2축 인장·전단 시험기의 개발 (Development of Biaxial Tension & Shear Tester using Stepper Motor with Harmonic Driver)

  • 최병선;배원호;채영석
    • 한국산업융합학회 논문집
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    • 제4권4호
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    • pp.379-386
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    • 2001
  • The lower toughness or brittle materials for mechanical test lead to the additional requirement that applied displacements be controlled with high resolution. Biaxial tension and shear tester using stepper motor with harmonic driver is shown. The device had to be high resolution so that the crack initiation process of slow extension and steady growth could be examined, Grip plates were connected to a linear bearing and actuator. The actuators consisted of stepper motors with harmonic driver connected to pre-loaded ball screw and nut assemblies. The encoders and motor controllers were connected to a personal computer so that arbitrary displacements histories could he prescribed in normal and tangential directions. The linear bearings were used to react loads perpendicular to their axes while allowing low friction, parallel movement of the attached grips. Load cells measured the reactions normal and tangential. the loads measured the reactions were recorded by the computer.

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긴장성 두통 및 불면을 주소로 입원한 환자의 간이정신진단검사(SCL-90-R)의 진단별 특성 (Symptom Checklist-90-Revision(SCL-90-R) in Inpatients on Tension headache and Insomnia)

  • 심상민;구병수;김경옥
    • 동의신경정신과학회지
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    • 제14권1호
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    • pp.117-131
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    • 2003
  • SCL-90-R is a multidimensional self-report symptom inventory devoloped by Derogatis and his coworkers. Since it was standardized into Korean version in 1978 by Won and Kim et aI., but it has been rarely studies for the clinical groups. Objectives : This study sought to define a diagnotic character of SCL-90-R of tension headache and insomnia inpatients groups. Methods : We determined a diagnotic character of 17 tension headache and 23 insomnia patients by means of SCL-90-R, and compared with normal groups in order to characterize subscale of SCL-90-R in patients with tension headache and insomnia from Neurasthenia. Results : 1. Male tension headache group has significant difference in Somatization and Depression subscales, female group in Somatization, Obsessive-Compulsive, Depression and Hostility subscales. 2. Female insomnia group has significant difference in Anxiety subscale. Although there are a little significiant, many subscales such as Somatization, Obsessive-Compulsive, Depression and Hostility are higher than normal group. 3. There are significant difference in GSI and PDSI of Global index, which means that we use that for objective index of tension headache and insomnia from Neurasthenia. Conclusions : All of these results show that SCL-90-R is useful inventory to characterize and screening for Neurasthenia.

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무기폐(無氣肺)가 폐표면활성도(肺表面活性度)에 미치는 영향에 관(關)한 실험적(實驗的) 연구(硏究) (Effects of Atelectasis on Surface Activity of lung in Rabbits)

  • 우종수;조광현;김종원;손말현;신근수;김진식
    • Journal of Chest Surgery
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    • 제9권2호
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    • pp.109-116
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    • 1976
  • The effects of atelectasis on surface activity of lung extracts were examined in rabbits. Experimental atelectasis was produced in rabbits by artificial pneumothorax and surface tension properties were measured on saline extracts of lung 24 hrs, 48 hrs, one week and four weeks after the induction of pneumothorax. The results were as follows; 1) The minimum surface tension of excised lung extracts 24 hrs after pneumothorax was significantly increased to 28.3 0.41 dynes/cm, and the stability index was significantly decreased to 0.30 from normal value of 0. 87. 2) In the group which was re-expanded 24 hours, later from pneumothorax the surface activity was returned to almost normal range 24 hrs after reexpansion of collapsed lung, 3) When the atelectasis was continued by mechanical means, the extracts of atelectatic lung showed progressive decrease in surface activity, but it was found that surface activity returned to normal level after four weeks even the presence of atelectasis. 4) These observations suggest to us that atelectasis per se does not cause an increase in surface tension of lung extracts, and even in prolonged atelectasis the re-expansion of collapsed lung may be possible when the mechanical cause of atelectasis was excluded.

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Force monitoring of Galfan cables in a long-span cable-truss string-support system based on the magnetic flux method

  • Yuxin Zhang;Xiang Tian;Juwei Xia;Hexin Zhang
    • Structural Monitoring and Maintenance
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    • 제10권3호
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    • pp.261-281
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    • 2023
  • Magnetic flux sensors are commonly used in monitoring the cable force, but the application of the sensors in large diameter non-closed Galfan cables, as those adopted in Yueqing Gymnasium which is located in Yueqing City, Zhejiang Province, China and is the largest span hybrid space structure in the world, is seldom done in engineering. Based on the construction of Yueqing Gymnasium, this paper studies the cable tension monitoring using the magnetic flux method across two stages, namely, the pre-calibration stage before the cable leaves the rigging factory and the field tension formation stage of the cable system. In the pre-calibration stage in the cable factory, a series of 1:1 full-scale comparative tests were carried out to study the feasibility and relability of this kind of monitoring method, and the influence on the monitoring results of charging and discharging voltage, sensor location, cable diameter and fitting method were also studied. Some meaningful conclusions were obtained. On this basis, the real-time cable tension monitoring system of the structure based on the magnetic flux method is established. During the construction process, the monitoring results of the cables are in good agreement with the data of the on-site pressure gauge.The work of this paper will provide a useful reference for cable force monitoring in the construction process of long-span spatial structures.

콘크리트가 RC 인장부재의 인장거동에 미치는 영향 (Effect of Concrete on the Tension Behavior of RC Members)

  • 홍창우;김남윤;윤경구;이봉학
    • 산업기술연구
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    • 제17권
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    • pp.145-151
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    • 1997
  • This paper presents evaluation results of the tensile behavior of reinforced high strength concrete. The effects of different sizes of reinforcing bar, ranging from D22 to D29, on the formation of cracks was investigated. Two different strength concretes, $270kg/cm^2$ and $550kg/cm^2$, were used in the specimens to investigate the influence if concrete strength on tension stiffening. In the present investigation a method was developed to obtain reliable load-deformation behavior in tension. The experimental results show that (1)high-strength concrete members exhibited larger amounts of tension stiffening than the companion normal-strength concrete members, (2) as the bar diameter increases, the beneficial influence of high-strength concrete on tension stiffening is reduced.

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활엽수(闊葉樹) Opposite재(材)의 구조(構造)(II) - 수평(水平) 생장(生長)시킨 유영목수간(幼 令木樹幹)의 Opposite재(材) 구조(構造) - (Structure of Opposite Wood in Angiosperms(II) - Structure of Opposite Woods in the Horizontal-growing Stems of Immature Woods -)

  • 박상진;박병수
    • Journal of the Korean Wood Science and Technology
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    • 제17권3호
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    • pp.20-27
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    • 1989
  • This experiment was made to find the peripheral variations of annualring widths, the cell dimensions, microfibril angles and bulk densities within each annual-ring of horizontal-growing young tree of beech(Betul a platyphylla var. japonica) and Oak (Quercus variabilis) from the tension to the opposite side. Also a comparision between the features of the obnormal annual ring for horizontal-growing year and normal annual ring for the straight-growing years was made. The dimension of propotion of the element, the microfibril angles and the bulk density decreased or increased continuously toward opposite side which showed minimum or maximum value. The dimension of elements the microfibril angles and the bulk density decreased or increased continuously towards opposite side which showed minimum or maximum value. The dimension of elements. the microfibril angles and the bulk density in the normal annual rings were similar to those in the lateral woods. whereas were significantly more different in the tension wood than in the opposite wood. The features of typical opposite wood in the hardwoods were influenced by the locations within the inclined stems than effects of the decrease in the annual ring width. The oppostie woods in hardwoods did not conform to the tension wood and lateral wood. The abnormal annual ring included the opposite wood, lateral wood similar to normal wood and tension wood having specialized structure even in the same annual ring.

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100 MPa급 수축보상 초고강도 변형경화형 시멘트 복합체를 사용한 인장부재의 인장강성 및 균열특성 (Tension-Stiffening and Cracking Behavior of 100 MPa Shrinkage-Compensated Ultra High-Strength Strain-Hardening Cement Composite (UHS-SHCC) Ties)

  • 송영재;윤현도
    • 콘크리트학회논문집
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    • 제25권4호
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    • pp.371-379
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    • 2013
  • 이 논문에서는 100 MPa 수축보상된 초고강도 변형경화형 시멘트 복합체 및 보통 콘크리트를 사용한 인장부재의 단조 및 반복재하시 인장강성 및 균열특성을 비교 평가하였다. 재하단계별 인장부재의 전체 변형률 및 표면균열 특성은 인장부재의 양측에 설치된 두 개의 변위계와 50배율 확대 가능한 계측기에 의해 측정되었다. 시멘트 복합체의 특성에 따른 인장부재의 인장 강성 및 균열특성을 평가하기 위하여 보통 콘크리트, 수축보상 변형경화형 시멘트 복합체 및 보통 변형경화형 시멘트 복합체 등 세 종류의 시멘트 복합체가 사용되었다. 실험 결과, 초고강도 변형경화형 시멘트 복합체의 시멘트 중량의 10%를 팽창재로 대체 시 초기 수축량은 현저하게 감소되었으며 인장부재의 초기균열강도도 증가되는 경향을 보였다. 수축보상된 초고강도 변형경화형 시멘트 복합체를 사용한 인장부재는 재하 단계별로 균열이 부재길이 전면에 확산되고 균열폭이 감소되어 인장강성 특성을 개선하였다. 반복재하시 인장부재의 인장거동 특성은 단조재하시와 큰 차이를 보이지 않았다.