• Title/Summary/Keyword: peak displacement

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A study on the structural of phospholipid membranes by thermally stimulated displacement current method (열자격 변위 전류법에 의한 인지질막의 구조 연구)

  • 이경섭;김우연;권영수;이준응;강도열
    • Electrical & Electronic Materials
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    • v.9 no.7
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    • pp.696-701
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    • 1996
  • In this study, deposited lipid membranes on the electrode and detected thermally stimulated displacement current generated from it. The researchers examined displacement current of electric conduction organic monolayer generated due to orient change of monolayers alkylchain and changed of dipole moment vertical component due to thermally stimulated. We paid attention to the phase transition temperature obtained by the thermally stimulated displacement current of lipid membrane layers this time. We detected the thermally stimulated displacement current peak of layers. From above results the transition temperature dilauroylphosphatidylcholine layers is about 43.deg. C. This study also compared above results with those obtained by differential thermal analysis method.

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Effects of Taping the Lower Back on the Lumbopelvic Region and Hip Joint Kinematics During Sit-to-Stand

  • Kim, Si-Hyun;Park, Kyue-Nam;Kwon, Oh-Yun;Choi, Houng-Sik
    • Physical Therapy Korea
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    • v.21 no.4
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    • pp.49-55
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    • 2014
  • Excessive lumbar flexion during sit-to-stand (STS) is a risk factor for lower back pain. Postural taping can prevent unwanted flexion of the lumbar spine. This study aimed to demonstrate the effect of taping the lower back on the lumbopelvic region and hip joint kinematics during STS. Sixteen healthy subjects participated. All subjects performed the STS with and without taping of the lower back. A three-dimensional motion analysis system was used to measure the kinematics of the lumbar spine, pelvis, and hip joint during STS. The angle of the peak lumbar flexion, pelvic anterior tilting, and hip flexion and angular displacement of the lumbar spine between starting position and maximal lumbar flexion were collected. Paired t-tests, or Wilcoxon's rank-sum test for non-parametric distribution, were used to assess differences in the measurements with and without taping. A p-value <.05 was taken to indicate a significant difference. Significant differences were observed in the angle of the peak lumbar flexion, pelvic anterior tilting, hip flexion and angular displacement of the lumbar spine (p<.05). Taping was associated with a significant decrease in the angle of peak lumbar flexion and angular displacement of the lumbar spine between the starting position and maximal lumbar spine flexion. In addition, the peak angle of pelvic anterior tilting and hip flexion were significantly increased with taping. The findings of this study suggest that taping the lower back can decrease excessive lumbar flexion, and increase the pelvic anterior tilting and hip flexion motion during STS.

A Comparative Study on the Temporomandibular Joint Sounds before and after Occlusal Splint Therapy Using Electrovibratography (두개하악장애환자의 교합안정장치에 의한 치료후 Sonopak을 이용한 악관절음 변화)

  • Hye-Sook Park;Jong-Hoon Choi;Chang-Seo Park
    • Journal of Oral Medicine and Pain
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    • v.21 no.1
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    • pp.67-78
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    • 1996
  • This study was performed to compare the TMJ sounds by means of vibration-related items by Sonopak such as integral, high integral, above 300/(0-300) ratio, peak amplitude, peak frequency and median frequency before and after occlusa1 splint therapy as well as counselling, physical modalities. For this study 22 patients with craniomandibular disorders (CMDs) were selected and examined by routine diagnostic procedure for CMDs including Transcranial and Panoramic radiographs and were classified into 3 CMDs subgroups : disc displacement with reduction, disc displacement without reduction, and degenerative joint disease. Visual analogue scale (VAS) about joint sound was recorded during treatment period and VAS treatment index (VAS Ti) was calculated from the VAS data and treatment duration. The author evaluated and compared treatment results by several parmeters such as symptom duration, timing of joint sound, parafunctional habits, trauma, and diagnostic classification. The obtained results were as follows : 1. Before the treatment, the highest value of peak amplitude was observed in disc displacement with reduction group and value of median frequency was highest in degenerative joint disease group. In addition the highest values of peak frequency and ratio ware observed in degenerative joint disease group, though they were not significant. Furthermore the lowest value of high integral was observed in disc displacement without reduction group and though it was not significant, value of integral was lowest in that group. 2. Among 3CMDs subgroups disc displacement with reduction group showed the significantly decreased value of high integral and degenerative joint disease group had the significantly decreased value of integral after conservative treatment including occlusal splint therapy. Conclusively conservative treatment including occlusal splint therapy vay be effective in the treatment of CMDs including TMJ sound. 3. Fair prognosis for conservative treatment was observed in acute group under 6 months than chronic group, 6 months over in symptom duration but there was no statistical difference. The result for conservative treatment was observed slightly poor in subjects with bruxism, clenching, unilateral chewing habit and trauma history but there were no statistical differences.

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Design, Construction and Use of a Displacement Cage for M(T) Specimens (중앙균열 피로시험편용 변위게이지의 설계, 제작과 활용)

  • Kim, Jeong-Yeop;Song, Ji-Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.3
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    • pp.415-427
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    • 2002
  • A clip-on type displacement gage was designed and manufactured to use for fatigue crack growth tests of M(T)(Middle-Tension) specimens. The displacement gage has good response for the deformation of the specimen and has been successfully used not only for constant amplitude loading tests but also far variable amplitude loading tests like as single peak overloading and random loading tests. All the materials for the gage can be obtained easily in domestic market, and the manufacturing cost is very low. It is expected that the designing procedure presented in this study can be applied usefully for designing other displacement gages.

Evaluation of responses of semi-rigid frames at target displacements predicted by the nonlinear static analysis

  • Sharma, Vijay;Shrimali, Mahendra K.;Bharti, Shiv D.;Datt, Tushar K.
    • Steel and Composite Structures
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    • v.36 no.4
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    • pp.399-415
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    • 2020
  • Responses of semi-rigid frames having different degrees of semi-rigidity obtained by the nonlinear static analysis (NSA) are evaluated at specific target displacements by comparing them with those obtained by the nonlinear time-history analysis (NTHA) for scaled earthquakes. The peak ground accelerations (PGA) of the earthquakes are scaled such that the obtained peak top story displacements match with the target displacements. Three different types of earthquakes are considered, namely, far-field and near-field earthquakes with directivity and fling-step effects. In order to make the study a comprehensive one, three degrees of semi-rigidity (one fully rigid and the other two semi-rigid), and two frames having different heights are considered. An ensemble of five-time histories of ground motion is included in each type of earthquake. A large number of responses are considered in the study. They include the peak top-story displacement, maximum inter-story drift ratio, peak base shear, total number of plastic hinges, and square root of sum of the squares (SRSS) of the maximum plastic hinge rotations. Results of the study indicate that the nonlinear static analysis provides a fairly good estimate of the peak values of top-story displacements, inter-story drift ratio (for shorter frame), peak base shear and number of plastic hinges; however, the SRSS of maximum plastic hinge rotations in semi-rigid frames are considerably more in the nonlinear static analysis as compared to the nonlinear time history analysis.

Displacement current of monolayer film on the water surface (수면상 단분자막의 변위전류)

  • 송경호;박태곤;박근호
    • Electrical & Electronic Materials
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    • v.9 no.7
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    • pp.674-679
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    • 1996
  • Using the home made Kuhn type LB (Langmuir - Blodgett) film's deposition apparatus, We measured the displacement current of monolayer film on the water surface. The obtained displacement current had each different pattern by the kind of solution while varying pressure of the monolayer. Solution of 4 - octyl - 4' - (5 - carboxyl - pentamethyleneoxy ) - azobenzene (8A5H) and stearic acid (CH$_{3}$(CH$_{2}$)$_{16}$COOH) (C18) were spreaded at the air water interface respectively, and the current induced by the dynamic behavior of molecules were pressed by barrier. Displacement current of 8A5H measured small current than C18 at same condition and it was positive direction when increasing pressure but it was negative direction when decreasing pressure. Also, Two patterns of displacement current were symmetrical form and appeared repeatedly. The C18 has unsymmetrical form of displacement current and weak current when decreasing pressure (expansion). The C18 molecules have two distinct peak values of displacement current that show that the orientations of molecules were changed largely at this points. From these results, we obtained that the 8A5H has more elasticity than the C18.8.C18.

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Ultra Precision Displacement Measuring System Using the Detection of Fringe Peak Movement (간섭무늬 최대점 이동량의 감지를 이용한 초정밀 변위 측정 시스템)

  • Yi, Jong-Hoon;Kim, Soo-Hyun;Kwak, Yoon-Keun
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.6
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    • pp.80-86
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    • 2001
  • This paper proposes a precision displacement measuring method of detecting fringe movement of interferograms with a nanometric resolution. It is well known that the laser interferometer plays a useful and essential role in scientific and industrial application, but they have such error sources as an unequal gain of detectors, imbalanced beams, and lack of quadrature. These error sources degrade the accuracy of the interferometer. However, the fringe movement of interferograms has little relation with these error sources. In order to investigate performance of the proposed method. analysis and simulation were executed over random noise and wavefront distorion. Results of the simulation show that the proposed method is robust against these errors. Experiment was implemented to verify this method.

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Heaving displacement amplification characteristics of a power buoy in shoaling water with insufficient draft

  • Kweon, Hyuck-Min;Cho, Il-Hyoung;Cho, Hong-Yeon
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.5 no.4
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    • pp.614-624
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    • 2013
  • The resonance power buoy is a convincing tool that can increase the extraction efficiency of wave energy. The buoy needs a corresponding draft, to move in resonance with waves within the peak frequency band where wave energy is concentrated. However, it must still be clarified if the buoy acts as an effective displacement amplifier, when there is insufficient water depth. In this study, the vertical displacement of a circular cylinder-type buoy was calculated, with the spectrum data observed in a real shallow sea as the external wave force, and with the corresponding draft, according to the mode frequency of normal waves. Such numerical investigation result, without considering Power Take-Off (PTO) damping, confirmed that the area of the heave responses spectrum can be amplified by up to about tenfold, compared with the wave energy spectrum, if the draft corresponds to the peak frequency, even with insufficient water depth. Moreover, the amplification factor of the buoy varied, according to the seasonal changes in the wave spectra.

A new equation based on PGA to provide sufficient separation distance between two irregular buildings in plan

  • Loghmani, Adel;Mortezaei, Alireza;Hemmati, Ali
    • Earthquakes and Structures
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    • v.18 no.5
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    • pp.543-553
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    • 2020
  • Past earthquakes experience shows that serious damage or collapse of buildings have dramatically accrued when sufficient separation distance has not been provided between two adjacent structures. The majority of past studies related to the pounding topic indicate that obtaining the gap size between two buildings is able to prevent collision and impact hazards during seismic excitations. Considering minimization of building collisions, some relationships have been suggested to determine the separation distance between adjacent buildings. Commonly, peak lateral displacement, fundamental period and natural damping as well as structural height of two adjacent buildings are numerically considered to determine the critical distance. Hence, the aim of present study is to focus on all mentioned parameters and also utilizing the main characteristic of earthquake record i.e. PGA to examine the lateral displacement of irregular structures close to each other and also estimate the sufficient separation distance between them. Increasing and decreasing the separation distance is inherently caused economical problems due to the land ownership from a legal perspective and pounding hazard as well. Therefore, a new equation is proposed to determine the optimum critical distance. The accuracy of the proposed formula is validated by different models and various earthquake records.

Probabilistic Distribution of Displacement Response of Frictionally Damped Structures under Earthquake Loads (지진하중을 받는 마찰형 감쇠를 갖는 구조물의 변위 응답 확률 분포)

  • Lee, Sang-Hyun;Park, Ji-Hun;Youn, Kyung-Jo;Min, Kyung-Won
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.639-644
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    • 2007
  • The accurate peak response estimation of a seismically excited structure with frictional damping system(FDS) is very difficult since the structure with FDS shows nonlinear behavior dependent on the structural period, loading characteristics, and relative magnitude between the frictional force and the excitation load. Previous studies have estimated that by replacing a nonlinear system with an equivalent linear one or by employing the response spectrum obtained based on nonlinear time history and statistical analysis. In the case that on earthquake load is defined with probabilistic characteristics, the corresponding response of the structure with FDS has probabilistic distribution. In this study, nonlinear time history analyses were performed for the structure with FDS subjected to artificial earthquake loads generated using Kanai-Tajimi filter. An equation for the probability density function (PDF) of the displacement response is proposed by adapting the PDF of the normal distribution. Finally, coefficients of the proposed PDF is obtained by regression analysis of the statistical distribution of the time history responses. Finally, the correlation between PDFs and statistical response distribution is presented.

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