• Title/Summary/Keyword: Skin Depth

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A Study on the Development of Reinforced Earth wall by Geotextile (토목섬유를 이용한 보강토옹벽의 개발)

  • 도덕현;유능환
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.28 no.2
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    • pp.63-73
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    • 1986
  • The model was developed by applying the principles of Bacot and Vidal to measure the behavior of deformation of the reinforced earth wall, and various tasts were performed by using the plastic fabric filter and the galvanized steel plate as a strip. The results obtained are as follows; 1. When the reinforced earth wall is deformed by the load, the strip is completely reinforced by the backfill materials and changed to the rigid block state, under the state of failure which permits sliding only, the next theoretical equation is formed. (H/L) . tan$\theta$ [cosO-sinOtanO] =2sinO[tan($\theta$ +0) +tanO] 2.The degree of the mutual reinforcement of the backfill material and the strip depend on the physical characteristics of the each material especially the angle of shearing resistance of the backfill material is desirable over 20$^{\circ}$ and, if it is over 400, its function could be a maximum. 3.The distribution of the maximum tensile strain of the reinforcement is changing with the height of reinforced earth wall, and when the height from bottom of the reinforced earth wall is 1.85 to 3. 35m, the maximum tensile strain appears at 2m from the skin element. The maximum tensile strain is increased by the depth of the reinforced earth wall from surface, and increased with the lapse of time after construction. 4.The failure surface of the reinforced earth wall by the concrete skin was about 60$^{\circ}$and the failure behavior of the reinforced earth wall in which the fabric filter was buried was slow, and so the pore pressure could be decreased. 5.It is possible to construct the fabric retained earth wall by the plastic fabric filter only. And the reinforcing effect between the steel plate and the plastic fabric filter is not largely different. however, in the aspect of the economic durability, the plastic fabric filter is more advantageous. 6.The reinforcing action mainly depends on the width and the length of the reinforcing materials, if possible, the full width is advantageous to enlarge the contact area with backfill. but considering the economic aspect, it is neccessary to develop the method controlling the space of the strip.

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A Study on the Forming Characteristic of Inner Pyramid Structure Bonded Sheet Metal (피라미드형 내부구조재를 가지는 중공형 접합판재의 성형특성에 관한 연구)

  • Kim, J.Y.;Kil, H.Y.;Cho, G.C.;Kim, J.H.;Chung, W.J.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2006.05a
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    • pp.295-299
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    • 2006
  • The inner-structure bonded(ISB) sheet metal is defined as a composite sheet metal which has middle layer of truss-structure between two skin sheets. The characteristics such as ultra-light weight, high rigidity, high strength, etc are required especially for automobile parts. The characteristic of ISB sheet metal depends on inner-structure pattern or method of bonding. Pyramid type of crimped expanded metal is used for inner-structure and both of resistance welding and adhesive bonding are applied to make a specimen. As a result of compression test, it is appeared that forming limit is 10% reduction in thickness under a load of 8kgf per unit element(one inner-structure). In case of uniaxial tensile test the non-uniform surface integrity rather than the buckling of inner-structure happened at a load of 450kgf, which indicates elongation of 7.2% and thickness reduction of 13%. The eye-inspection method was applied to examine the defects occurring on the specimen during stretch forming. In case of biaxial stretch forming only the non-uniform deformation on the surface of a skin sheet could be observed. The forming limit in stretching of ISB sheet metal with the hemi-spherical punch of 150mm in diameter was 3mm in forming depth and 5% reduction in thickness.

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Surface Mapping of Masseter for Botulinum Toxin Injection (교근에서 보툴리눔 독소 주사점의 표지화)

  • Kim, Jun Hyung;Lee, Min Jae;Kim, Hyun Ji;Son, Dae Gu;Han, Ki Hwan;Lee, So Young;Lim, Jung Guen;Choi, In Jang
    • Archives of Plastic Surgery
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    • v.32 no.3
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    • pp.311-313
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    • 2005
  • Generally, many Asian women tend to dislike the square jaw, as they believe it makes the face look wider, giving a stubborn and strong impression. Contouring of the mandible is therefore a relatively common aesthetic procedure among Asians. These days, the use of botulinum toxin for contouring of the lower face offer simple alternative to surgery. Motor point, which is the site over a muscle where its contraction may be elicited by a minimal intensity short duration electrical stimulus, is the optimal injection point of botulinum toxin. Study was undertaken to identify the location of motor point of the masseter muscle and the skin surface landmark. First, the thickest point of the masseter muscle was inspected through palpation and inspection by 3 different individual plastic surgeons and then compound muscle action potentials(CMAPs) of masseter muscle in 15 health volunteers were recorded using EMG. For the localization of the measured points, line between lateral canthus to the mandibular angle was used. Location of motor points were mapped to skin surface from lateral canthus in a percentage of the distance along the landmark line and in distance in millimeters. The clinical injection point was located at 71.69 percentile and 7.3 mm of the landmark line. The motor point test was located at 72.54 percentile and 7.1 mm of the landmark line. The depth of motor point was 16mm. There was no statistically significant difference between the clinical injection point and the motor point. We conclude that surface mapping of motor point of the masseter muscle would increase accessibility and accuracy in botulinum toxin injection for contouring of the lower face.

Cyclic performance and design recommendations of a novel weak-axis reduced beam section connection

  • Lu, Linfeng;Xu, Yinglu;Liu, Jie;Lim, James B.P.
    • Steel and Composite Structures
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    • v.27 no.3
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    • pp.337-353
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    • 2018
  • In previous weak-axis moment connection tests, brittle fracture always initiated near the edge of the beam flange groove weld due to force flow towards the stiffer column flanges, which is the opposite pattern as strong-axis moment connections. As part of the China NSFC (51278061) study, this paper tested two full-scale novel weak-axis reduced beam section moment connections, including one exterior frame connection specimen SJ-1 under beam end monotonic loading and one interior frame joint specimen SJ-2 under column top cyclic loading. Test results showed that these two specimens were able to satisfy the demands of FEMA-267 (1995) or ANSI/AISC 341-10 (2010) without experiencing brittle fracture. A parametric analysis using the finite element software ABAQUS was carried out to better understand the cyclic performance of the novel weak-axis reduced beam section moment connections, and the influence of the distance between skin plate and reduced beam section, a, the length of the reduced beam section, b, and the cutting depth of the reduced beam section, c, on the cyclic performance was analyzed. It was found that increasing three parametric values reasonably is beneficial to forming beam plastic hinges, and increasing the parameter a is conducive to reducing stress concentration of beam flange groove welds while increasing the parameters b and c can only reduce the peak stress of beam flange groove welds. The rules recommended by FEMA350 (2000) are suitable for designing the proposed weak-axis RBS moment connection, and a proven calculation formulation is given to determine the thickness of skin plate, the key components in the proposed weak-axis connections. Based on the experimental and numerical results, a design procedure for the proposed weak-axis RBS moment connections was developed.

Fabrication of Microwave Applicator for Hyperthermia and Thermal Distribution in Tissues (종양의 온열치료를 위한 마이크로잔 조사장치의 제작과 응용)

  • Chu S. S.;Lee J. T.;Kim G. E.
    • Radiation Oncology Journal
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    • v.2 no.1
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    • pp.11-20
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    • 1984
  • The renewed interest in the use of hyperthermia in cancer therapy is bases on radiobiological and clinical evidence indicated that there may be a significant therapeutic advantage with the use of heat alone or combined with radiation or chemotherapy, There are many methods for generating heat for localized tumor as like radiofrequency, microwave, electromagnetic induction and ultrasound. But it is very difficult to be even thermal dose distribution and stable output of power and then the detection of temperature in tumor is difficult to be precise with thermocouples and semiconductor sensors. We designed the microwave heating generator, dipole antenna applicators and autometic temperature controlled thermocouples for localized hyperthermia on skin and in cavities. 1. The microwave generator with 120 W, 2,450MHz magnetron could be heating up to $40^{\circ}C\~50^{\circ}C\;for\;1\~2$ hours in living tissues. 2. The thermal dose distribution in tissue with microwave was described $42^{\circ}C\~44^{\circ}C$ with in 3 cm depth and $2\~6cm$ diameter area. 3. Skin surface heating applicator with spiral 3 times wave length antenna radiated high Power of microwave. 4, Intracavitary heating applicator with dipole antenna with autometic control temperature sensor kept up continuously constant temperature in tissue. 5. For constant thermal distribution, applied two steps power with 10W microwave after $17\~20W$ during first 10 minutes. 6. The cooling rate by blood flew in living tissue was rised as $10\%$ then meats.

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Hair growth promoting effects of emodin in telogenic C57BL/6 mice

  • Yon, Jung-Min;Park, Seul Gi;Lin, Chunmei;Gwon, Lee Wha;Lee, Jong-Geol;Baek, In-Jeoung;Lee, Beom Jun;Yun, Young Won;Nam, Sang-Yoon
    • Korean Journal of Veterinary Research
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    • v.56 no.2
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    • pp.97-101
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    • 2016
  • Emodin is an anthraquinone derivative from the roots of Rheum officinale Baill that possesses a variety of biological activities, including inhibition of $5{\alpha}$-reductase and prostaglandin D2. In this study, we investigated whether emodin promotes hair growth. After emodin was topically applied to the shaved dorsal skin of telogenic C57BL/6 N mice, the hair growth rate and morphological analysis were evaluated in dorsal skin for 15 days. After 13 days of treatment, minoxidil or emodin (0.01% or 0.1%)-treated groups showed remarkable regrowth of hairs relative to the vehicle control group. Scoring of the hair growth and rate of hair growth area for 15 days revealed that groups treated with minoxidil and 0.1% emodin were significantly higher than the vehicle control group. Histological examination revealed the emodin and minoxidil groups markedly recovered the number and morphology of hair follicles, including the subcutis depth, relative to the vehicle group. These results suggest that emodin has an excellent promoting effect in hair growth similar to that of minoxidil and might be useful for treatment of baldness or alopecia.

Single use Automatic Lancet to Minimize Pain During Skin Puncture (피부관통시 통증을 최소화하는 일회용 자동 모세혈액 채취기구)

  • 김현식;김경아;전명희;김태임;정용현;이태수;차은종
    • Journal of Biomedical Engineering Research
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    • v.23 no.4
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    • pp.323-327
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    • 2002
  • Chronic diabetic patients need to sample capillary blood for monitoring and controlling the blood sugar level. Frequent sampling requires to minimize pain during skin puncture. The present study developed mechanisms to minimize pain with effective sampling procedure. which consisted of tapered spring, guiding tunnel, and 30G needle Penetration depth was limited to within 2mm for pain reduction as well as for safety. Simple no-reuse mechanism also prevented the cross-patient and secondary infection possibility. Clinical experiments demonstrated the best convenience and safety with minimal pain in the diabetes, normal, and nursing students groups. Sing1e blood sampling was enough for successful blood sugar test by portable analyzer. The present sing1e use auto-lancet should be of great convenience in frequent capillary blood sampling for the diabetes.

Fabrication of Indium Tin Oxide (ITO) Transparent Thin Films and Their Microwave Shielding Properties (Indium Tin Oxide (ITO) 투광성 박막의 제조 및 전자파 차폐특성)

  • Kim, Yeong-Sik;Jeon, Yong-Su;Kim, Seong-Su
    • Korean Journal of Materials Research
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    • v.9 no.11
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    • pp.1055-1061
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    • 1999
  • Indium Tin Oxide (ITO) films were fabricated by vacuum deposition technique and their microwave shielding properties were investigated for the application to the transparent shield material. The vacuum coating was conducted in a RF co-sputtering machine. The film composition and structure associated with the sputtering conditions (argon and oxygen pressure. substrate temperature. RF input power) were investigated for the attainment of high electrical conductivity and good transparency. The electrical conductivity of IT0 films fabricated under the optimum deposition conditions (substrate temperature : $300^{\circ}C$. Ar flow rate : 20 sccm, Oxygen flow rate : 10 sccm, In/Sn input power : 50/30 W) showed 5.6$\times10^4$mho/m. The optical transparency is also considerably good. The microwave shielding properties including the dominant shielding mechanism are investigated from the electrical conductivity, thickness and skin depth of the ITO films. The total shielding effectiveness is then estimated to be 26 dB, which provides a suggestion that the IT0 films can be effectively used as the transparent shield material.

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Rheological Evaluation of Petroleum Jelly as a Base Material in Ointment and Cream Formulations : Linear Viscoelastic Behavior

  • Park, Eun-Kyoung;Song, Ki-Won
    • Journal of Pharmaceutical Investigation
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    • v.41 no.3
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    • pp.161-171
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    • 2011
  • The objective of the present study is to systematically characterize a linear viscoelastic behavior of petroleum jelly in small amplitude oscillatory shear flow fields correspondent to the rheological ground state. With this aim, using a strain-controlled rheometer, the dynamic viscoelastic properties of commercially available petroleum jelly have been measured at $37^{\circ}C$ (body temperature) over a wide range of angular frequencies at an extremely small strain amplitude of 0.1 %. In this article, the linear viscoelastic behavior was reported in detail and then explained from a structural view-point of petroleum jelly and discussed in depth with respect to the consumer's requirements. Main findings obtained from this study can be summarized as follows : (1) The storage modulus is always greater than the loss modulus over an entire range of angular frequencies studied, meaning that the linear viscoelastic behavior of petroleum jelly is dominated by an elastic nature rather than a viscous nature. (2) Petroleum jelly shows a desirable linear viscoelastic behavior with respect to the consumer's requirements because it is undesirable for the product to flow down from the skin at an initial stage upon contact with the human skin. (3) A fractional derivative model shows an excellent applicability to describe a linear viscoelastic behavior of petroleum jelly. However, this model should be used with a special caution because there exists no physical meaning for the model parameters. (4) A modified form of the Cox-Merz rule gives a good ability to predict the relationship between steady shear flow properties (nonlinear behavior) and dynamic viscoelastic properties (linear behavior) for petroleum jelly.

Effect of Heparin on Expression of mRNA of MMP 1,2,9 in Adult Rat Wound (헤파린이 쥐의 창상치유에서 MMP-1,2,9 mRNA의 발현에 미치는 영향)

  • Kim, Han Koo;Hong, Jung Soo;Kim, Sae Hwan;Lee, Mi Kyoung;Kim, Seung Hong;Kim, Woo Seob
    • Archives of Plastic Surgery
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    • v.34 no.2
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    • pp.149-155
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    • 2007
  • Purpose: This study was to investigate how the heparin, which has been known to induce neovascularization by MMP in the infarcted tissue of the myocardium, had influence on the expression of mRNA of MMP 1,2,9 of the skin wound of rat. Methods: Full depth skin wounds were created on the dorsum of Sprague-Dawley 60 rats. The experimental rats were divided into two groups according to the concentration of heparin($100{\mu}g/ml$ in 20, $300{\mu}g/ml$ in 20). Heparin soaked gelatin sponges in different concentration were inserted into the pocket of experimental rats and the wounds were closed. Normal saline soaked gelatin sponges were used in control rats. Wounds were harvested at 48 and 72 hours after closure. We performed histologic study in H-E stain. RNA was isolated from the harvested tissue and then real time polymerase chain reaction was performed to determine the gene expression of MMP-1,2,9. Results: We observed that inflammatory cell decreased in heparin soaked group and heparin increased the expression of MMP-1,9 mRNA of dorsal wound of rat at 72 hours (p < 0.05). Conclusion: This result suggest that heparin may be used inducing another factor inducing scarless wound healing by increasing MMP.