• Title/Summary/Keyword: Static condition

Search Result 1,224, Processing Time 0.023 seconds

Comparative Study of Seeding and Culture Methods to Vascular Smooth Muscle Cells on Biodegradable Scaffold

  • Kim, Dong-Ik;Park, Hee-Jung;Eo, Hyun-Seoun;Suh, Soo-Won;Hong, Ji-Hee;Lee, Min-Jae;Kim, Jong-Sung;Jang, In-Sung;Kim, Byung-Soo
    • Journal of Microbiology and Biotechnology
    • /
    • v.14 no.4
    • /
    • pp.707-714
    • /
    • 2004
  • How to improve the cell culture method on scaffolds is important in the tissue engineering fileld. In this study, we optimized seeding and culture methods to vascular smooth muscle cells (VSMCs) on biodegradable polymer scaffold. The primary culture of VSMCs obtained from canine external jugular vein was accomplished by applying the explant-derived method. The primary cultured VSMCs were seeded into scaffolds and then cultured by using various different methods; static or dynamic seeding, static or dynamic culture. The difference in proliferative response of VSMCs was analyzed with an alamar blue assay. Cell-polymer construct was examined by histochemical method and scanning electron microscopy. Mesh type scaffold ($10 \times 10 \times0.4 mm$) was made of polyglycolic acid (PGA) suture thread. The PGA mesh type scaffold was 45% in porosity, and 0.03 g in weight. The primary cultured VSMCs were confirmed with immunohistochemical staining using monoclonal anti-$\alpha$-smooth muscle actin. The density and distribution of proliferated VSMCs within the scaffold and cellular adherence on the surface of the scaffold showed better results in the static seeding condition than in the dynamic condition. Under the same condition of seeding method as the static condition, the dynamic culture condition showed enhanced proliferation rates of the VSMCs when compared to the static culture condition. In conclusion, to improve the VSMCs proliferation in vitro, static seeding is better than the dynamic condition. In the culture condition, however, culture under the dynamic status is better than the static condition. This was a pilot study to manufacture artificial vascular vessel by tissue engineering.

Comparison of Effects on Static Balance in Stroke Patients According to Visual Biofeedback Methods

  • Kyu-Seong Choi;Il-Ho Kwon;Won-Seob Shin
    • Physical Therapy Rehabilitation Science
    • /
    • v.12 no.3
    • /
    • pp.320-326
    • /
    • 2023
  • Objective: The purpose of this study is to investigate the impact of visual biofeedback methods utilizing pressure sensors on the static balance of stroke patients. Design: Randomized crossover study. Methods: A total of 27 patients with hemiparesis participated in this study. The following three feedback conditions were considered: condition 1 (Knowledge of performance feedback), condition 2 (Knowledge of result feedback), and condition 3 (None feedback). A force plate was used to measure static balance. The total sway length, average sway velocity, x-axis excursion, and y-axis excursion of the center of pressure were measured. One-way repeated-measures analysis of variance was employed for comparisons of variables between each condition. The statistical significance level was set at α = 0.05 for all analyses. Results: There was a significant difference in the static balance results between each feedback condition (p<0.05). In the post-hoc results, it was confirmed that the static balance was significant in the order of knowledge of performance feedback, knowledge of result feedback, and none feedback. Conclusions: When comparing the three conditions, it was observed that knowledge of performance feedback showed the most improved effect on static balance ability. As further research progresses, that this approach could be used as an effective intervention method in clinical settings.

Effects of elevation on shoulder joint motion: comparison of dynamic and static conditions

  • Takaki Imai;Takashi Nagamatsu;Junichi Kawakami;Masaki Karasuyama;Nobuya Harada;Yu Kudo;Kazuya Madokoro
    • Clinics in Shoulder and Elbow
    • /
    • v.26 no.2
    • /
    • pp.148-155
    • /
    • 2023
  • Background: Although visual examination and palpation are used to assess shoulder motion in clinical practice, there is no consensus on shoulder motion under dynamic and static conditions. This study aimed to compare shoulder joint motion under dynamic and static conditions. Methods: The dominant arm of 14 healthy adult males was investigated. Electromagnetic sensors attached to the scapular, thorax, and humerus were used to measure three-dimensional shoulder joint motion under dynamic and static elevation conditions and compare scapular upward rotation and glenohumeral joint elevation in different elevation planes and angles. Results: At 120° of elevation in the scapular and coronal planes, the scapular upward rotation angle was higher in the static condition and the glenohumeral joint elevation angle was higher in the dynamic condition (P<0.05). In scapular plane and coronal plane elevation 90°-120°, the angular change in scapular upward rotation was higher in the static condition and the angular change in scapulohumeral joint elevation was higher in the dynamic condition (P<0.05). No differences were found in shoulder joint motion in the sagittal plane elevation between the dynamic and static conditions. No interaction effects were found between elevation condition and elevation angle in all elevation planes. Conclusions: Differences in shoulder joint motion should be noted when assessing shoulder joint motion in different dynamic and static conditions.

Comparison of Lateral Pile Behavior under Static and Dynamic Loading by Centrifuge Tests (원심모형 실험을 이용한 지반-말뚝 상호작용의 정적 및 동적 거동 평가)

  • Yoo, Min-Taek;Kwon, Sun-Yong
    • Journal of the Korean Geotechnical Society
    • /
    • v.34 no.7
    • /
    • pp.51-58
    • /
    • 2018
  • In this study a series of centrifuge tests were carried out in dry sand to analyze the comparison of lateral pile behavior for static loading and dynamic loading condition. In case of static loading condition, the lateral displacement was applied up to 50% of pile diameter by deflection control method. And the input sine wave of 0.1 g~0.4 g amplitude and 1 Hz frequency was applied at the base of the soil box using shaking table for dynamic loading condition. From comparison of experimental static p-y curve obtained from static loading tests with API p-y curves, API p-y curves can predict well within 20% error the ultimate subgrade reaction force of static loading condition. The ultimate subgrade reaction force of experimental dynamic p-y curve is 5 times larger than that of API p-y curves and experimental static p-y curves. Therefore, pseudo-static analysis applied to existing p-y curve for seismic design could greatly underestimate the soil resistance at non-linear domain and cause overly conservative design.

Static Output Feedback Control for Continuous T-S Fuzzy Systems (연속시간 T-S 퍼지 시스템에 대한 정적 출력궤환 제어)

  • Jeung, Eun Tae
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.21 no.6
    • /
    • pp.560-564
    • /
    • 2015
  • This paper presents a design method of a static output feedback controller for continuous T-S fuzzy systems via parallel distributed compensation (PDC). The existence condition of a set of static output feedback gains is represented in terms of linear matrix inequalities (LMIs). The sufficient condition presented here does not need any transformation matrices and equality constraints and is less conservative than the previous results seen in [20].

Non-PDC Static Output Feedback Control for T-S Fuzzy Systems (T-S 퍼지 시스템에 대한 비병렬분산보상 정적 출력궤환 제어)

  • Jeung, Eun Tae
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.22 no.7
    • /
    • pp.496-501
    • /
    • 2016
  • This paper presents a design method of non-parallel distributed compensation (non-PDC) static output feedback controller for continuous- and discrete-time T-S fuzzy systems. The existence condition of static output feedback control law is represented in terms of linear matrix inequalities (LMIs). The proposed sufficient stabilizing condition does not need any transformation matrices and equality constraints and is less conservative than the previous result of [21].

Critical heat flux (CHF) in pool boiling under static and rolling conditions

  • Tanjung, Elvira F.;Albdour, Samah A.;Jeong, Yeon Uk;Jo, Daeseong
    • Nuclear Engineering and Technology
    • /
    • v.52 no.3
    • /
    • pp.520-529
    • /
    • 2020
  • Experimental investigations were attempted to simultaneously observe the vapor behaviors and critical heat flux under static and rolling conditions. From visualization results, vapor initiated, grew, and detached individually in a vertical direction from the static heated surfaces (at 10, 20, and 30°). While under rolling motion, initiated vapor grew, and interacted with each other, resulting in forming a wider dry spot on the heated surface. Also, it was observed that the vapor drifted upward and stayed on the heated surface longer compared to under static condition. The faster the platform rolls, the longer the vapor stay on the heated surface, significantly decreasing the CHF. On the other hand, as the platform rolls slower (at high rolling period), CHF increases. CHF was decreased with increasing maximum rolling amplitude and inclination angle under both conditions (static and rolling). CHF under rolling conditions was noticed to be lower than under static condition except at maximum rolling amplitude of 10°. The bubble departure frequency at a maximum rolling amplitude of 10° was the highest among all of rolling amplitudes, thereby enhancing the CHF. These results indicate that rolling motion significantly affects vapor behaviors and CHF.

Reliability Verification of Numerical Prediction Method on Pile Behaviour Characteristics using Field Static Loading Test (현장정재하시험을 이용한 말뚝 거동특성 수치해석 예측기법의 신뢰성 검증)

  • Nam, Hosung;Baek, Seungcheol
    • Journal of the Korean GEO-environmental Society
    • /
    • v.18 no.9
    • /
    • pp.11-18
    • /
    • 2017
  • Numerical analysis method for prediction of pile behaviour characteristics has widely been used in detail design process before construction because field static loading test requires high cost. However, the reliability verification of numerical analysis of result is not permitted compare with field test. In this study, to verify the numerical analysis results, pile behaviour prediction was compared with field static loading test results. For exact analysis of interaction between pile and ground, soil investigation and in-situ test such as boring, SPT and bore-hole shear test were performed before pile static loading test. During the static loading test, pile behaviour characteristics were analyzed under every loading condition. After static pile loading test, numerical analysis was carried out under same condition with static pile loading test. In the numerical analysis, to apply same loading condition with each loading condition in the field test and to compare with between the results of numerical analysis, the field test results for reliability were verified with the results of numerical analysis.

Pseudo seismic and static stability analysis of the Torul Dam

  • Karabulut, Muhammet;Genis, Melih
    • Geomechanics and Engineering
    • /
    • v.17 no.2
    • /
    • pp.207-214
    • /
    • 2019
  • Dams have a great importance on energy and irrigation. Dams must be evaluated statically and dynamically even after construction. For this purpose, Torul dam built between years 2000 and 2007 Harsit River in Gümüşhane province, Turkey, is selected as an application. The Torul dam has 137 m height and 322 GWh annual energy production capacity. Torul dam is a kind of concrete face rock fill dam (CFRD). In this study, static and pseudo seismic stability of Torul dam was investigated using finite element method. Torul dam model is constituted by numerical stress analysis named Phase2 which is based on finite element method. The dam was examined under 11 different water filling levels. Thirteenth stage of the numerical model is corresponding full reservoir condition which water filled up under crest line. Besides, pseudo static coefficients for dynamic condition applied to the dam in fourteenth stage of the model. Stability assessment of the Torul dam has been discussed according to the displacement throughout the dam body. For static and pseudo seismic cases, the displacements in the dam body have been compared. The total displacements of the dam according to its the empty state increase dramatically at the height of the water level of about 70 m and above. Compared to the pseudo-seismic analysis, the displacement of dam at the full reservoir condition is approximately two times as high as static analysis.

An Evaluation of the Tolerance of the Static Characteristics for Light Weight Torpedoes (경어뢰의 정특성 허용오차 산정)

  • 나영인
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.5 no.2
    • /
    • pp.149-158
    • /
    • 2002
  • Static Characteristics of the system, such as weight, center of gravity etc., are inspected and regulated through the whole design process of a light weight torpedo system, and the nominal condition of the characteristics is prescribed for standardization of manufacturing and fabrication. It is possible that a real system or assembled system has different static characteristics from that of the nominal condition. It is required to evaluate the tolerance of the static characteristics within which the performance of the system should not be contaminated by the static characteristics. In this paper, an evaluation method of the tolerance is described for light weight torpedo systems. The method is to check on the performance and related critical parameters of light weight torpedoes. The checking items are composed of general conditions of underwater mobile systems such as stability and dynamic sensitivity and specified performance requirements for light weight torpedoes.