• Title/Summary/Keyword: Thickness reduction

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Design Method of Steel Slit Shear Walls with Tapered Links for Structural Condition Assessment

  • He, Liusheng;Wu, Chen;Jiang, Huanjun
    • International Journal of High-Rise Buildings
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    • v.9 no.4
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    • pp.361-368
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    • 2020
  • The authors developed a new type of steel slit shear wall (SSSW) having the function of structural condition assessment through visually inspecting the out-of-plane deformation of the designed tapered links subjected to lateral deformation. To facilitate its practical application, this paper studies how to design dimensions of the tapered links. Two parameters, the width-to-thickness ratio of the tapered links and steel yield stress, were studied. The performance of structural condition assessment was affected by both parameters with the width-to-thickness ratio being the controlling one. Through both numerical and experimental study, the designed width-to-thickness ratio of tapered links for different levels of structural condition assessment was established considering the effect of different steel grades used. In practice, the dimensions of tapered links can be determined following the design equation provided. Finally, a design procedure for the proposed SSSW system is provided.

Evaluation of Thickness Reduction in Steel Plate by Using SH-EMATs (수평횡파 송수신용 EMAT를 이용한 스틸 박판의 두께 감육 평가)

  • Lee, Jin-Hyuk;Park, Ik-Keun;Kim, Yong-Kwon;Kim, Dae-Hyun
    • Journal of the Korean Society for Nondestructive Testing
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    • v.31 no.1
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    • pp.47-52
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    • 2011
  • An electromagnetic acoustic transducer(EMAT) is a non-contact transducer which can transmit the ultrasonic guided waves into specimens without couplant. And it can easily generate specific guided waves such as SH(shear horizontal) or Lamb waves by altering the design of coil and magnet. In this study, the SH wave, which is generated by EMAT, has been applied to estimate the thickness-reduction in a steel plate. Especially, the interesting feature of the dispersive behavior in selected wave modes is used to detect the thickness-reduction. Experimental results show that the reduction-level can be quantified by the measurement of the group velocity of the wave which passes though the thinning area.

Cross Finger Flap with Reduction Pulp Plasty and Full Thickness Skin Graft (수질부 축소술과 전층 피부이식술을 이용한 교차수지 피판술)

  • Cho, Yong Hyun;Roh, Si Gyun;Lee, Nae Ho;Yang, Kyung Moo
    • Archives of Plastic Surgery
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    • v.36 no.5
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    • pp.674-677
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    • 2009
  • Purpose: Typical cross finger flap is still a good method for reconstruction of fingertip injuries. However, it is necessarily followed by great loss and aesthetically unpreferable result of donor finger. Hereby, we introduce a modification of cross finger flap with reduction pulp plasty and full thickness skin graft, with which we could reduce the defect size of injured fingertip and donor site morbidity at the same time, without any need for harvesting additional skin from other part of hand. Method: This method was performed in the patients with fingertip injuries of complete amputation or in case of loss of fingertip due to necrosis after replantation. Firstly, reduction pulp plasty was performed on the injured finger to reduce the size of defect of fingertip. Additional skin flap was obtained from the pulp plasty. Secondly, cross finger flap was elevated from the adjacent finger to cover the defect on the injured finger. At the same time, defect on the donor finger produced by the flap elevation was covered by full thickness skin graft with the skin obtained from the pulp plasty of injured finger. Results: Flap and graft survived without any necrosis after surgical delay and flap detachment. All of them were healed well and did not present any severe adversary symptoms. Conclusion: Cross finger flap with reduction pulp plasty and full thickness skin graft is an effective method that we can easily apply in reconstruction of fingertip injury. We think that it is more helpful than the usual manner, especially in cases of children with less soft tissue on their fingers for preservation and reduction of the morbidity of donor finger.

Effect of Thickness Change in Corrugations on the Stiffness and Vibration Characteristics of a Thermoformed Diaphragm (열성형 진동판의 미세주름 두께변화가 구조강성 및 진동특성에 미치는 영향 분석)

  • Kim, K.M.;Park, K.
    • Transactions of Materials Processing
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    • v.23 no.1
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    • pp.10-15
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    • 2014
  • Recently, micro-speakers have attracted much attention due to their increasing demand in mobile devices. Micro-speakers use polymer diaphragms, which are manufactured from thin polymer film by the thermoforming process. The diaphragm is generally designed to be a circular membrane with a cross section consisting of a double dome structure, and a number of corrugations are located in the outer region to produce better sound quality. In the current study, a finite element (FE) analysis is performed for thermoforming, and the resulting thickness reduction in the corrugation regions is estimated. The estimated thickness distribution is used in further structural and modal FE analyses, from which the effects of local thickness reduction on the stiffness and vibration characteristics are determined.

An experimental study on corrosion properties of reinforcing steel under environment of complex deterioration (표면피복종류에 따른 복합열화환경하의 철근콘크리트 부식특성에 관한 실험적 연구)

  • 조봉석;김영덕;윤종기;김재환;김용로;김무한
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.11a
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    • pp.86-89
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    • 2003
  • It is recognized that reinforcement corrosion is the main distress behind the present concern regarding concrete durability. In this study, to confirm corrosion of reinforced concrete affected by thickness of cover, kinds of surface coating, measured electric potential, ratio of corrosion area, weight reduction, corrosion velocity of steel bar under environment of complex deterioration. The results showed that an increase in age also increases corrosion of steel bar. Ratio of corrosion area is largely related to ratio of weight reduction. as well, corrosion of steel bar by thickness of cover is superior to l0mm thick than 20mm thick. It showed that an increase in thickness of cover prevent steel bar from deteriorating. The results of this study showed that corrosion velocity was affected by thickness of cover, kinds of surface coating. data on the development of corrosion velocity made with none, organic B, organic A, inorganic B, and inorganic A is shown.

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Noise Reduction Effect of an Air Bubble Layer on an Infinite Flat Plate Considering the Noise of Multi-bubbles (다중기포 발생소음을 고려한 무한평판 주위에 형성된 수중 기포층의 방사소음 감소 효과)

  • Kim, Jong-Chul;Heo, Bo-Hyun;Cho, Dae-Seung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.11
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    • pp.1222-1230
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    • 2009
  • A theoretical model was developed to compute the effect of a bubble layer in reducing the radiation noise generated by a force applied on an infinite flat plate considering the noise of multi-bubbles. Using the model, the effectiveness of a bubble layer in reducing the structure-borne noise of the plate was evaluated to consider various parameters such as the source noise levels, the thickness of bubble layers, the volume fractions and the frequency characteristics of bubbly fluids. Considering the noise of multi-bubbles, the actual reduction effect of radiation noise using a bubble layer was expected in cases of high source levels, high volume fractions of bubbles and large thickness of the bubble layer above the resonance frequency of the bubble layer. Accordingly, it is recommended that the thickness of a bubble layer, the source noise level and the characteristics of bubbly fluids should be optimized cautiously to maximize noise reduction effects.

Improvement of shear deformation by controlling reduction per a rolling pass during asymmetrical cold rolling in AA 5052 (AA5052 판재의 비대칭 냉간압연 시 압연 패스당 압하율 제어에 의한 전단 변형 향상)

  • Kang, H.G.;Han, Y.H.;Huh, M.Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2007.05a
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    • pp.226-228
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    • 2007
  • During asymmetrical cold rolling in AA 5052 sheet a reduction per a rolling pass was varied to investigate the effect of the ratio of the contact length between the roll and sample ($l_c$) to the sheet thickness (d) on the formation of shear textures. In order to intensify the shear deformation during asymmetrical rolling, AA 5052 sheet was asymmetrically cold rolled without lubrication by using different roll velocities of upper and lower rolls. Asymmetrical rolling with $l_c$/d=1.8 led to the formation of texture gradients throughout the sheet thickness in which the outer thickness layers depicted shear textures and the center thickness layers displayed a rolling texture. Asymmetrical rolling with $l_c$/d=3.1 gave rise to the formation of shear textures in the whole through-thickness layer. The strain states associated with asymmetrical rolling were investigated by the finite element method (FEM) simulation. FEM results indicated that the evolution of deformation texture in a thickness layer is strongly governed by integrated values of strain rates and along the streamline in the roll gap.

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Consideration of Various Medial Capsulorrhaphy Methods in Hallux Valgus Surgery (무지 외반증의 수술 중 시행하는 내측 관절낭 봉합술의 방법에 대한 고찰)

  • Choi, Sung-Jong;Kim, Byung-Cheol;Eun, Il-Soo;Huh, Jung-Wook
    • Journal of Korean Foot and Ankle Society
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    • v.12 no.1
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    • pp.9-13
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    • 2008
  • Purpose: Medial capsulorrhaphy is additional hallux reduction method following various hallux reduction procedures and we are going to report author's opinion about several methods of medial capsulorrhaphy. Materials and Methods: We performed three kinds of medial capsulotomy and imbricatory capsulorrhaphy in hallux valgus surgery. Through 8 cadavar study, we compared the easiness of sesamoid reduction and hallux valgus angle reduction. Also, we measured thickness of capsule in various portions. Results: Longitudinal capsule incision and imbrication was useful in sesamoid reduction and vertical procedures was useful in hallux valgus angle reduction. The capsule thickness was measured thickest in dorsal and distal portioin. Conclusion: The methods of medial capsulorrhaphy should be planned preoperatively considering individual hallux deformities. These selected medial capsulorrhaphy can help the reduction of hallux valgus deformity correction and its maintenance.

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The thickness of Cu Filter to reduce 1/2 of the patient dose (X선 진단시 피폭선량을 반으로 줄이기 위한 Cu Filter의 두께)

  • Kim, Jung-Min;Kim, Sung-Chul
    • Journal of radiological science and technology
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    • v.24 no.1
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    • pp.17-22
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    • 2001
  • Medical X-ray examination are increased double for the last $6{\sim}8$ years. Therefore a patient exposure dose should be decrease half every 7 years. We made an experiment on copper filter thickness to decrease a patient exposure dose up to half and compared to the Image quality by MTF. The results as follow 1. A thin region like extremities needs a thicker Cu filter as compared a thick region. 2. 1/2 reduction filter must be thicker when kVp Increase. 3. Exposure factor should be increas when using 1/2 reduction filter ; extremity is 4.0 times, chest 2.9 times, skull 1.62 times, and abdomen 1.58 times 4. The MTF of using 1/2 reduction filter is lower than without filter. But no difference of visual image. 5. 1/2 reduction filter compared with double speed screen showed almost same image quality.

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Quality and Sensory Characteristics of Reduced-fat Chicken Patties with Pork Back Fat Replaced by Dietary Fiber from Wheat Sprout

  • Choi, Yun-Sang;Sung, Jung-Min;Park, Jong-Dae;Hwang, Ko-Eun;Lee, Cheol-Won;Kim, Tae-Kyung;Jeon, Ki-Hong;Kim, Cheon-Jei;Kim, Young-Boong
    • Food Science of Animal Resources
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    • v.36 no.6
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    • pp.799-806
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    • 2016
  • The effects of reducing pork fat levels from 20% to 15% or 10% by partially substituting pork back fat with wheat sprout fiber in reduced-fat chicken patties were investigated. Approximate composition, energy value, pH, color, cooking loss, reduction in diameter, reduction in thickness, shear force, and sensory properties were determined. Moisture content, ash contents, yellowness of uncooked and cooked reduced-fat chicken patties with wheat sprout were higher than those in the control, while displaying fat content, calorie content, and pH of uncooked and cooked lower in reduced-fat chicken patties than in the control. Cooking loss, reduction in diameter, and reduction in thickness were the highest in the reduced-fat chicken patties with 10% fat level. Cooking loss, reduction in diameter, and reduction in thickness were decreased when fat levels and wheat sprout levels were increased. Control samples without wheat sprout dietary fiber had significantly (p<0.05) higher color and flavor scores compared to reduced-fat chicken patties containing wheat sprout dietary fiber. The overall acceptability of the control and treatment with 15% fat and 2% wheat sprout dietary fiber (T3) was the highest. Therefore, 15% fat level in reduced-fat chicken patties with the addition of 2% wheat sprout dietary fiber can be used to improve the quality and sensory characteristics of regular-fat chicken patties containing 20% fat level.