• Title/Summary/Keyword: Plastic release

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A Behavior of Clayey Foundation Using Elasto-plastic Constitutive Model - On the Lade's Model, Cubical Triaxial Test and the Determination of Soil Parameters- (탄.소성구성식에 의한 점토지반의 거동해석 (I) -Lade의 모델, 입방체 삼축시험 및 토질매개변수 결정-)

  • 이문수;이광동;오재화
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.35 no.4
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    • pp.106-118
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    • 1993
  • The purpose of this study is to develop a multireservoir water balance model which may be used to evaluate rural water demands such as agricultural water, domestic water, industrial water and livestock water and to determine effective storage of reservoir. The model was verified to compare the observed reservoir release data with the simulated reservoir release data of the existing Munsan and Dongbu reservoirs located in the Gisan rural district for 3 years('87~'89). For model application, the effective storages of existing reservoirs(Munsan & Dongbu) were evaluated for 10-year frequency drought and that of newly planned reservoirs(Kumbok & Kudong) were determined for 10-year frequency drought. In addition, the behavior of effective storages for existing reservoirs were analyzed in the case of introducing new reservoirs in the existing system.

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The Energy Release Rate for Cracks in a Rotating Continuum (균열을 내재한 회전체의 에너지방출률)

  • 이태원
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.2
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    • pp.330-337
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    • 1995
  • For a rotating body with cracks, the new energy release rate equation is presented. The derived equation is different from the other researcher's results. It is a path-independent integral which excluded the derivatives of displacements near the crack tip, thereby improving the numerical accuracy of the energy release rate computation. Moreover, as the equation was derived on basis of the energy principle and non-linear elasticity without assumptions, it can applied to the cracked body with arbitrary shape under elastic-plastic deformation. Several examples are treated to demonstrate the efficiency and accuracy of the proposed method compared to existing methods.

C-arm Guided Surgical Excision of Heterotopic Calcification (방사선 영상장치 모니터링하 이소성 석회화 절제술)

  • Choi, Hwan-Jun;Choi, Yim-Don;Park, Nae-Kyeong;Kim, Yong-Bae
    • Archives of Plastic Surgery
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    • v.38 no.2
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    • pp.194-198
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    • 2011
  • Purpose: Heterotopic calcification is the abnormal deposition of calcium salts in tissues other than bone and enamel, and it occurs in the form of dystrophic calcification or metastatic calcification. This deposition can occur under many conditions, but in some rare cases, it may develop in burns and nonhealed scars. It is difficult to treat the combination of heterotopic calcification and ulceration in scar tissues by using conservative therapy and to determine the margin of excision in such cases. Our study proposes the use of intraoperative C-arm-guided mapping of lesions with heterotopic calcification, and adequate excision of ulcers in chronic scars where heterotopic calcification is also observed. Methods: This study included 2 patients and was conducted from January 2010 to July 2010. The first patient was a 63-year-old woman who presented with atypical calcium deposits and chronic ulceration in the lower one-third region of the right leg. The second patient was a 38-year-old man who presented with a nonhealing ulcer that had developed on the right leg 3 months earlier he had a history of 40% scalding burns on the entire body. Surgery is the most reliable method for treating heterotopic calcification therefore, both patients were treated using intraoperative C-arm-guided marginal mapping of heterotopic calcification, followed by release of contracture, and eventually split-thickness skin grafting. Results: Plain radiographs of the leg showed spotty radiopaque areas in the hard part of the scar well superficial to the underlying bones. Histopathological analysis revealed multiple foci of calcified deposits, increased fibrosis, and inflammation in the scar tissue. Surgery-related complications were not observed. Conclusion: C-arm guided excision of calcified scars and the release of contracture can cure nonhealing ulcers and may therefore prevent recalcification.

Hand Resurfacing with Full Thickness Skin Graft from the Palm Ulnar Border (손날 부위에서의 전층 피부이식을 이용한 수부 피복)

  • Song, Jung-Yoon;Eun, Seok-Chan;Baek, Rong-Min
    • Archives of Plastic Surgery
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    • v.38 no.5
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    • pp.649-654
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    • 2011
  • Purpose: Split-or full-thickness skin grafts are used to reconstruct palmar skin and soft tissue defects after trauma or to release burn scar contracture on the hand. Glabrous skin defects should be substituted with similar skin to preserve function and aesthetics. The authors report their experiences with a technique that uses a full-thickness graft taken from glabrous skin on the ulnar edge of the palm for the reconstruction of soft tissue defects of the hand. Methods: During a three-year period from 2007 to 2010, 22 patients with burn scar contracture and 12 patients with post-traumatic skin defects on their hands were treated with full-thickness skin graft operations. The palmar skin and soft tissue defects after release of burn scar contracture or debridement of post-traumatic wounds were reconstructed with full-thickness skin grafts harvested from the ulnar border of their palms. All donor-site wounds were primarily closed. Results: The followup periods ranged from 3 to 25 months. Contractures of the hand were corrected without recurrence, and the grafts showed relatively good contour and color match to the adjacent fields. There were no reported complications such as significant color change or hypertrophic scarring. The grafted skin showed an average 5.9 mm static two-point discrimination obtained in fingertip reconstruction cases, indicating satisfactory reinnervation. Conclusion: Glabrous full-thickness grafts harvested from the palmar ulnar border is a very useful way of reconstructing soft tissue defects on hands, including fingertips, for function restoration, favorable aesthetic results, and low donor-site morbidity.

Application of Supercharge End-to-Side (SETS) Obturator to Femoral Nerve Transfer in Electrical Injury-Induced Neuropathy to Improve Knee Extension

  • Katie Pei-Hsuan Wu;Li-Ching Lin;Johnny Chuieng-Yi Lu
    • Archives of Plastic Surgery
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    • v.49 no.6
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    • pp.769-772
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    • 2022
  • Femoral nerve injuries are devastating injuries that lead to paralysis of the quadriceps muscles, weakening knee extension to prohibit ambulation. We report a devastating case of electrical injury-induced femoral neuropathy, where no apparent site of nerve disruption can be identified, thus inhibiting the traditional choices of nerve reconstruction such as nerve repair, grafting, or transfer. Concomitant spinal cord injury resulted in spastic myopathy of the antagonist muscles that further restricted knee extension. Our strategy was to perform (1) supercharge end-to-side technique (SETS) to augment the function of target muscles and (2) fractional tendon lengthening to release the spastic muscles. Dramatic postoperative improvement in passive and active range of motion highlights the effectiveness of this strategy to manage partial femoral nerve injuries.

The Energy Release Rate of the Two Dimensional Cracked Body Under Thermal Stresses, Body Forces and Crack-Face Tractions (열응력, 내력 및 균열 경계하중을 고려한 2차원 균열문제의 에너지방출율)

  • 이태원
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.9
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    • pp.2172-2180
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    • 1993
  • Under general loadings, including body forces, crack-face tractions and thermal loading, the energy release rate equation for a two-dimensional cracked body is presented. Defining the virtual crack extension as the variation of the geometry, the equation is directly derived by a shape design sensitivity of the potential energy. Although the form of the derived energy release rate equation is different from other researchers's results, the three example show that the former is exactly the same as the latter. However, the final integral equation do not involve the derivative of the displacement on the crack surface and crack tip region, thereby improving the numerical accuracy in the computation of the energy relase rate. Moreover, as it was derived from the governing equation including non-linear elasticity without special assumptions, the energy release rate of a elasto-plastic fracture can be obtained and any numerical stress analysis method can be applied.

Urethroplasty in Male Pseudohermaphroditism (남성 가성반음양 환자에서의 요도성형술)

  • Kim, Seok Kwun;Ha, Jae Seong;Lee, Keun Cheol;Park, Jung Min
    • Archives of Plastic Surgery
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    • v.32 no.1
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    • pp.110-116
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    • 2005
  • Male pseudohermaphroditism is individuals with Y chromosome whose external appearances fail to develop as expected as a normal male. Cytogenetic form of male pseudohermaphroditism was 46XY but external genital forms were variable. We reviewed data from 7 patients with male pseudohermaphroditism operated in Dong-A University Hospital from January 1996 to August 2002. They all had severe form of hypospadias (pseudovaginal perineoscrotal type). Only 1 of 7 cases was operated urethroplasty by one stage method, and all others by two stage method. Patients with mild chordee were operated by one stage method and patients with severe chordee were operated by two stage method. Complete chordee release was done by Z-plasty or FTSG on the first stage and posterior urethroplasty was done at level of mid-dorsum of shaft at the same time. Anterior urethroplasty was done completely on the second stage. Results were good from the viewpoint of shape and urination. Urethral fistula occurred in two cases, but other complications (infection, urethral stricture, etc.) didn't occur. In conclusion, two stage method was compatible to correct hypospadias in male pseudohermaphroditism, because hypospadias in male pseudohermaphroditism is in severe form.

Effect of Solvents on Physical Properties and Release Characteristics of Monolithic Hydroxypropylmethylcellulose Matrix Granules and Tablets

  • Cao Qing-Ri;Choi Yun-Woong;Cui Jing-Hao;Lee Beom-Jin
    • Archives of Pharmacal Research
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    • v.28 no.4
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    • pp.493-501
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    • 2005
  • Effect of solvents on physical characteristics and release characteristics of monolithic acetaminophen (APAP) hydroxypropylmethylcellulose (HPMC) matrix granules and tablets were examined. Various types and amounts of solvents were employed for granulation and coating. APAP and other excipients were mixed and were then wet-granulated in a high-speed mixer. The dried granules were then directly compressed and film-coated with low viscosity grade HPMC. As the amount of water increased, the size of granules also increased, showing more spherical and regular shape. However, manufacturing problems such as capping and lamination in tableting occurred when water was used alone as a granulating solvent. The physical properties of HPMC matrix granules were not affected by the batch size. The initial release rate as well as the amount of APAP dissolved had a tendency to decrease as the water level increased. Addition of nonaqueous solvent like ethanol to water resulted in good physical properties of granules. When compared to water/ethanol as a coating solvent, the release rate of film-coated HPMC matrix tablets was more sensitive to the conditions of coating and drying in methylene chloride/ethanol. Most of all, monolithic HPMC matrix tablet when granulated in ethanol/water showed dual release with about $50\%$ drug release immediately within few minutes followed by extended release. It was evident that the type and amount of solvents (mainly water and ethanol) were very important for wet granulation and film-coating of monolithic HPMC matrix tablet, because the plastic deforming and fragmenting properties of material were changed by the different strengths of the different solvents.

Anterolateral thigh flap for 1st web contracture release (전외측 대퇴부 유리피판술 이용한 제1 수지간 반흔구축 재건)

  • Kim, Ki Wan;Lee, Dong Chul;Kim, Jin Soo;Ki, Sae Hwi;Roh, Si Young;Yang, Jae Won
    • Archives of Plastic Surgery
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    • v.36 no.2
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    • pp.147-152
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    • 2009
  • Purpose: First web space contracture of the hand has been treated with various surgical techniques such as Z - plasty, local flap, pedicled flap, distant free flap, and anterolateral thigh free flap. Among those surgical techniques, anterolateral thigh free flap provide a thin and pliable flap, which is a useful method for correction of first web space contracture. Methods: From August 2003 to September 2007, authors selected 9 patients who had first web space contracture with limitation of thumb abduction within 30 degrees. All of patients had received first web contracture release with anterolateral thigh free flap. Age ranged from 24 to 51, and all the patients were male. Average follow up period was 12 months and authors performed photographic analysis of the thumb abduction angle of postoperative increase. Result: All the flaps were survived. Donor site was closed with primary closure in 8 cases and covered with split - thickness skin graft in 1 case. Average flap size was $8{\times}9cm$ and average thickness was 0.6 cm in suprafascial flap. The procedure resulted in increased thumb abduction angle of $34.7^{\circ}$ in average and showed concave shape of first web space in suprafascial flap. Additional operations were performed with Z - plasty in 3 cases, local flap in 5 cases, and opponensplasty in 3 cases. Conclusion: In suprafascial flap, we obtained relatively thin flap thickness and were able to make natural concave shape of first web space. In releasing severe contracture of the first web space, anterolateral thigh free flap provided a good coverage of appropriate thickness and pliable soft tissue and allowed limited donor site morbidity.