• Title/Summary/Keyword: Tension range

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A Study on the Midwater pair Trawling-III (쌍끌이 중층트롤어업의 연구 ( III ) - 끌줄의 예망장력에 관하여 - ( A Study on the Midwater Pair Trawling ( III ) ))

  • Jang, Choong-Sik;Lee, Byoug-Gee
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.32 no.1
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    • pp.1-6
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    • 1996
  • Towing tension of the model nets were determined by the load cell(O~20kg, 20DBBP) in front of W$T_mA$ = 1.57 . $V^1.86$ (unit: kg, mlsec) $T_mB$= 1.58 . $V^1.90$ 2. The towing tension of the full scale net was almost coincided with the results obtained by the model experiment. The towing tension(T) can be expressed as a function of the towing veJocity(V) as T=479$V^1.75$(unit: kg, k't)

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Purification and Characterization of Biosurfactants Produced by Pseudomonas sp. SW1

  • Suk, Wan-Su;Son, Hong-Joo;Lee, Geon;Lee, Sang-Joon
    • Journal of Microbiology and Biotechnology
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    • v.9 no.1
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    • pp.56-61
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    • 1999
  • Pseudomonas sp. SW1 grew and produced biosurfactants on 3% hexadecane as the energy and carbon source. As a result of biosurfactant synthesis, the surface tension of the medium was reduced from 72 dyne/cm to 30 dyne/cm. The properties of biosurfactants that were purified from Pseudomonas sp. SW1 were investigated. The purification procedure included acid precipitation from culture supernatant, silica gel G60 column chromatography, and Sephadex G-150 gel filtration. The biosurfactants were separated into two different types, viz., types I and II. Biosurfactant type Isignificantly reduced the surface tension of water from 72 to 27 dyne/cm at concentration levels above 30 mg/l. The surface tension of water was reduced to a minimum of approximately 30 dyne/cm by biosurfactant type II at concentration levels over 80 mg/l. The biosurfactants were effective in a wide range of pHs, at NaCl concentrations of up to 4%, at $CaCl_2$ concentration up to 100 mM, and at temperatures up to $200^{\circ}C$ for 8 h.

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Development of a Tensile Force Measurement Device of Long Duration (인장력 상시 측정장치 개발에 관한 연구)

  • Shin, Kyung Jae;Hwang, Yun Ha
    • Journal of Korean Society of Steel Construction
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    • v.15 no.4 s.65
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    • pp.435-445
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    • 2003
  • Tension member is one of the most important elements in tension structure. An economical and reliable measurement method of a member's tensile force has yet to be developed, however. Several conventional measurement methods have some disadvantages when used for long-term, on-site measurement. A new tension-force measurement device was proposed to resolve measuring problems. Its principle was to use the bending part of the device as an elastic spring. The lateral deformation of the bending part due to tensile force can be measured to monitor the tensile force. This device was inserted in the tension member like a turn-buckle. Lateral deformation may be measured in the field at any time for the purpose of maintaining structures. Finite element analysis was used to design the shape and parametric study. Six specimens were tested within the elastic range. The test result showed that the elastic behavior or the bending part was consistent with the analysis' results.

An Experimental Study on Biaxial Tensile Characteristics of ETFE Film and Stress Relaxation of Tension Typed Membrane Structures (ETFE 필름의 2축 인장특성 및 텐션방식 막구조물의 응력완화 거동에 관한 실험적 연구)

  • Kim, Seung-Deog;Jeong, Eul-Seok;Kawabata, Masaya
    • Journal of Korean Association for Spatial Structures
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    • v.16 no.1
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    • pp.35-42
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    • 2016
  • Until recently, almost all ETFE film structures that have been erected is the cushion type because there are problems at lower allowable strength under elastic range and viscosity behaviour such as creep and relaxation of ETFE films under long-term stresses. But the number of tension type structures is currently increasing. This paper proposes the stretch fabrication of ETFE film to verify the applicability of ETFE films to tensile membrane structures. First of all, to investigate the possibility of application on tensile membrane structures, the stretch fabrication test is carried out, and it is verified that it is possible to increase the yield strength of the film membrane structures. After simulating the experiment also carries out an analytical investigation, and the effectiveness of the elasto-plastic analysis considering the viscous behavior of the film is investigated. Finally, post-aging tension measurement is conducted at the experimental facilities, and the viscosity behavior resulting from relaxation is investigated with respect to tensile membrane structures.

THE FINITE ELEMENTS ANALYSIS IN THE THREE DIMENSIONAL CELL CULTURE MODEL OF THE COLLAGEN MATRIX ACCORDING TO THE APPLICATION FORCE (교원섬유 기질을 이용한 3차원 세포 배양 모델에 기계적인 힘을 가하는 경우 기질을 통하여 세포에 가해지는 힘의 특성에 대한 비교 분석 연구)

  • Kim, Hyeon-Jong;Rhyu, In-Chul;Park, Jun-Woo;Kim, Seong-Gon
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.34 no.2
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    • pp.151-156
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    • 2008
  • Different kinds of forces can be applied to the biological tissue. The analysis of the applied force is highly important to explain the mechanism of cellular response. In this study, the applied force to the collagen gel was analyzed by the finite elements analysis. The model received two different kinds of static force (compression and tension). The force range was 50g to 400g. In results, von Mises stress was concentrated in the peripheral region in the compression model. It was concentrated in the central area in the tension model. However, the compressive force was high in the peripheral area of the compression model and the tensional force was also high in the same area of the tension model. In conclusion, the applied force could be different to the region and it should be considered in the experiment to analyze the effects of the mechanical force on the cells.

Tension and Corrosion Properties of Nb-added Ferritic Stainless Steel for Industrial Applications (Nb 첨가된 페라이트계 스테인리스강의 인장 및 부식 특성)

  • Han, D.I.;Gizem, K.;Choi, S.K.;Cho, S.H.;Ko, Y.G.
    • Transactions of Materials Processing
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    • v.30 no.6
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    • pp.301-305
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    • 2021
  • The role of Nb addition in the tension and corrosion responses of ferrite-based stainless-steel sheets processed by cold-rolling and annealing treatment at 1173 °K was studied to evaluate the possibility for commercialization. For this purpose, the grain sizes in the samples with and without Nb content were controlled to be reasonably identical by utilizing different heat treatments within the specific range for 60 seconds. The corrosion properties of both samples were evaluated based on the analysis of polarization curves. Room-temperature tension testing showed that the strength of the sample with Nb was much higher than that without Nb whereas the elongation of the sample with Nb was slightly lower than that without Nb. The polarization curves revealed that the addition of Nb contributed to the significant improvement in protective capabilities. We thought that such combinational behavior was mainly due to the formation of niobium carbides found in the ferritic matrix.

Experimental Studies on the Vascular Smooth Muscle of $Cd^{2+}$-poisoned Rabbits (카드뮴중독(中毒) 가토(家兎)의 동정맥(動靜脈)에 관하여)

  • Hong, Ki-Whan
    • The Korean Journal of Pharmacology
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    • v.15 no.1_2 s.25
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    • pp.29-37
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    • 1979
  • The tension-length relationships and reactivity of vascular smooth muscle in longitudinal strips from portal vein ana in helical strips from thoracic aorta and pulmonary artery of normotensive control and cadmium-hypertensive rabbits were studied in vitro. 1. The mean arterial pressures of non-poisoned control rabbits was $87.0{\pm}4.7 mmHg$. However, Cd-poisoned group revealed the significant increase in pressure by $109.04{\pm}2.8 mmHg$ (p<0.005). 2. By tension-length studies, strips from portal vein of Cd-poisoned group stretched a greater percent increase in length in response to an applied resting force from 0.25 to 5 g than did those from non-poisoned group. On the contrary, strips from thoracic aorta of Cd-poisoned group showed less compliant than those from control, i.e. the former underwent a less percent increase in length than the latter. Passive tension-length relations of pulmonary artery was unaffected by Cd-hypertension. 3. The force of contraction(active tension) was significantly lowered in strips from aorta of Cd-hypertensive group throughout the range of $0.5{\sim}2g$ passive tension. However, there was no significant difference in the development of active tension of portal vein or pulmonary artery of both groups. 4. The $K^+$-contraction in the portal vein, aorta and pulmonary artery of Cd-poisoned group made no difference in the active force from those of control group. 5. The force of contraction in the strips from aorta of Cd-poisoned group was significanty decreased compared to that of control. The results suggested that the alterations in vascular reactivity to contracting substances and in distensibility to passive tension were induced in the Cd-hypertensive rabbits.

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Improvement of the Elbow Function with Early Mobilization and Rigid Fixation of Coronoid Fracture by Tension Band Technique (압박 긴장대 방법을 이용한 구상 돌기 골절의 견고한 고정과 조기 운동을 통한 주관절 기능의 향상)

  • Rhyou, In-Hyeok;Suh, Bo-Gun;Kim, Hyung-Jin;Chung, Chae-Ik;Kim, Kyung-Chul
    • Clinics in Shoulder and Elbow
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    • v.12 no.2
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    • pp.159-166
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    • 2009
  • Purpose: We wanted to evaluate the surgical results of early mobilization after rigid fixation of small coronoid fracture using the tension band technique Materials and Methods: Eight cases of coronoid fracture were fixed with the tension band technique and using K-wire and wire through the medial approach. All the cases were Regan-Morrey type 2. According to O'Driscoll, they were classified as 5 cases of the tip type (subtype 2) and 3 cases of the anteromedial type (1 case of subtype 2, and 2 case of subtype 3). The associated collateral ligament injuries (6 cases) and radial head/neck fractures (4 cases) were managed simultaneously. After immobilization for 5~7 days, active ROM exercise with a fitted hinge brace started and continued till postoperative 6 weeks. The patients were assessed for pain, ROM and functional disability using the Mayo elbow performance score (MEPS) at an average of 11 months (range: 6~28 months). The ulnar nerve symptoms were also investigated. Results: We observed solid union in all the coronoid fractures without hardware failure. An average of 2.2 wires (range: 2~4) were used. The mean extension was $3^{\circ}$(range: $0^{\circ}\sim25^{\circ}$), the mean flexion was $137^{\circ}$(range: $130^{\circ}\sim140^{\circ}$), the mean pronation was $69^{\circ}$(range: $45^{\circ}\sim90^{\circ}$) and the mean supination was $78^{\circ}$(range: $45^{\circ}\sim90^{\circ}$). The mean MEPS was 96 (range: 65~100). Ulnar nerve symptoms occurred at postoperative one day and persisted in one patient with the terrible triad of taking radial head excision and residual medial instability. Conclusion: The tension band technique uses easily obtained, economic K-wires and the wire was strong enough to permit early elbow ROM exercise and the technique might improve the elbow function. It was especially useful for fixation of multiple small fragments.

Behavior of Mooring Line of Silt Protector According to the Change of Sea Level (조위변화에 따른 오탁방지막 계류라인의 거동)

  • 홍남식;김정윤
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.14 no.3
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    • pp.232-239
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    • 2002
  • This paper studies the behavior of mooring line of silt protector according to the change of sea level. It is found from the analysis of the behavior that if the taut cable length has been determined appropriately within the range of safety factor, the tensioned cable has almost constant tension regardless of the water depth. The whole structure, however, becomes unstable due to the loss (zero tension) of the released cable tension. It is also recognized from the investigation for the effect of intial straight line angle on the behavior of mooring line that the design through the conceptually combined consideration of the cable tension, total scope and buoy deflection has to be required in the mooring analysis. Finally, the material of cable is not damaged because the cable tension is reduced by attached shellfish, but the whole structure may be also unstable by the effect on the anchor angle, total scope and buoy deflection.

A Study on the Preocessing of high Runctional Composites and the Evaluation of Its Characteristics (고기능성 복합재료의 제조와 그 특성평가에 관한 연구)

  • 김윤해
    • Journal of Advanced Marine Engineering and Technology
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    • v.22 no.2
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    • pp.139-145
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    • 1998
  • Filament winding method is widely used for composite fabrications using low viscosity liquid for-mation and processing asymmetrical structures of pressure vessel pipe rocket motor case etc. The filament winding method is affected by several parameters such as pot life of process time viscosi-ty of resin filament winding temperature and schedules curing condition and post curing condi-tion of resin. To develope high functional composite materials the rotation(5, 15, 20, 30rpm) of the winding machine was controlled by D.C motor. And the wiper to give proper tension was equipped between strand and resin bath. The resin is hooked by the design wiper. The adequate cure schedule was found by DSC. NOL ring test is carried out to investigate the basic physical properties such as design technology. The void contents in filament winding is generally higher than that of the prepreg laminated plate. These high contents of void can make a crack in resin in spite of low deformation. These problem was solved by giving tension in processing. To improve the characteristics of fiber volume fraction void contents resin/fiber bonding the winding speedc is changed under constant tension. It was found that resin impregnation was not different from in fiber contents void contents at the range of 0.5~1kg tension but it was found that resin was not impregnated at the above of 1.5kg tension. In burst test a pure PE liner was failed at a nozzle part under the $14kg/\textrm{cm}^2$ pressure but a pressure vessel of CNG was failed at a cylinder part under the $200kg/\textrm{cm}^2$ pressure.

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