• Title/Summary/Keyword: Skin Resistance

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Sportswear Physiological Optimization: Effects of Clothing ease, local heating and materiales (운동복의 기능성과 쾌적성에 관한 연구)

  • Lee Young Suk;An Tae Whan
    • Journal of the Korean Society of Clothing and Textiles
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    • v.15 no.2 s.38
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    • pp.127-138
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    • 1991
  • The aim of the present stud)r has been to obtain new and additional data allolwing a better design of sports garments as well as a better choice among some materiales, through measure-ment of body surface changes in the upper trunk in movement, measurement on the effects of local heating on other parts of the body and measurement of the thermal resistance of 6 types of materials applied on a manikin. In the first experiment, the upper trunk was divided in 32 Parts, the surface of which was measured by the tape method for two upper limb positions: extension at $90^{\circ}$ and $180^{\circ}$. In the second experiment, skin temperature, local thermal sensations and whole body thermal sensation were measured every 5 minutes during 40 minutes. The four areas of the shoulder, abdomen, hande and feet were heated with the hot pack at $50^{\circ}C$. In the third experiment, the regional thermal resistance of the various materials selected, in two different cases of clothing ease, have been measured by using a thermal manikin. Resultes of experiments were: 1. Extensions cause the upper front part of the trunk surface to lengthen vertically while the back tends to stretch in width. 2. Skin temperatures of the upper limbs are influenced by the abdomen and shoulder boatings. The correlation between the whole body thermal sensation and the upper trunk thermal sensation is significantly asserted. 3. Ceramic and aluminium coated materiales offer the most effective thermal resistance; ease in clothing increases the thermal resistance at the breast and the abdomen as well as the clo value of the materials.

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A Study on the Resistance Welding of Metallic Sandwich Panel : Part 1 - Determination of Process Parameters (저항 용접을 이용한 금속 샌드위치 판재 접합에 관한 연구 : Part 1 - 공정변수의 선정)

  • Lee Sang-Min;Kim Jin-Beom;Na Suck-Joo
    • Journal of Welding and Joining
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    • v.23 no.6
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    • pp.49-54
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    • 2005
  • Inner Structured and Bonded(ISB) panel, a kind of metallic sandwich panel, consists of two thin skin plates bonded to a micro-patterned inner structure. Its overall thickness is $1\~3mm$and it has attractive properties such as ultra-lightweight, high efficiency in stiffness-to-weight and strength-to-weight ratio. In many previous studies, resistance welding, brazing and adhesive bonding are studied for joining the panel. However these methods did not consider productivity, but focused on structural characteristics of joined panels, so that the joining process is very complicated and expensive. In this paper, a new joining process with resistance welding is developed. Curved surface electrodes are used to consider the productivity and the stopper is used between electrodes during welding time to maintain the shape of inner structure. Welding time, gap of electrodes and distance between welding points are selected as the process parameters. By measuring the tensile load with respect to the variation of welding time and gap of electrodes, proper welding conditions are studied. Welding time is proper between 1.5-2.5cycle. If welding time is too long, then inner structures are damaged by overheating. Gap of electrode should be shorter than threshold value fur joint strength, when total thickness of inner structure and skin plate is 3.3mm, the threshold distance is 3.0mm.

Analysis of a Bi-directional Load Test Result on tong PHC Piles in Consideration of Residual Load (잔류하중을 고려한 장대 PHC 말뚝의 양방향 재하시험 결과해석)

  • Kim, Sung-Ryul;Chung, Sung-Gyo;Lee, Bong-Yeol
    • Journal of the Korean Geotechnical Society
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    • v.24 no.6
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    • pp.85-93
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    • 2008
  • For long piles driven in deep clay deposits, it is difficult to estimate the ultimate bearing capacity due to large resistance induced by long embedded depth, and also the load transfer curve due to large residual load induced by negative skin friction, even with the performance of pile load tests. In this research, a hi-directional load test on a PHC pile driven in deep soft deposit was performed in order to evaluate the tip and shaft resistances separately, which are feasible to estimate the ultimate bearing capacity of the pile. Residual load of the pile was determined by continuous monitoring of pile strains after the pile installation. The true resistance and true load-movement curve of the pile were properly estimated by taking account of the residual load. A model far behavior of the shaft resistance vs. movement was also proposed, which includes the effects of residual load based on the experiment. Consequently, it was proved that the residual load should be taken into consideration for correctly analyzing load test results of piles in deep clay deposits.

A Effect of Moisturizing Cream containing Ceramide from Evening Primrose Oil on the Moisturization and Transepidermal Water Loss in Human Skin (달맞이꽃오일에서 얻은 Ceramide를 함유한 보습크림의 피부 보습 및 경피수분손실량에 미치는 영향 연구)

  • Park, Sang Hyun;Lee, Kun Kook;Lee, Kwang Sik;Park, Hyun Ji;Lee, Byoung Hwan
    • Journal of the Korean Applied Science and Technology
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    • v.35 no.4
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    • pp.1243-1249
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    • 2018
  • Ceramides are commonly studied and developed in the cosmetics industry as ingredients that help a moisturized skin and strengthen a skin barrier. In this study, we determined how much great effects the moisturing cream containing a ceramide, obtained from evening primrose oil instead of using a common synthetic ceramide, made on the changes in moisturizing and transdermal water loss of skin. The result showed that the cream with a ceramide showed much better results than the cream without a ceramide at the skin moisture resistance and transdermal water loss of skin.

Pathological findings of paraquat poisoning in mice, rats and rabbits (마우스, 랫트 및 토끼에서 paraquat 중독의 병리학적 관찰)

  • Lee, Suk-joo;Cho, Sung-whan
    • Korean Journal of Veterinary Research
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    • v.34 no.2
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    • pp.339-347
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    • 1994
  • This study was carried out to investigate the pathological changes with paraquat(1.1'-dimethyl-4.4'-dipyrildiylium dichloride) administered by intraperitoneally, orally, skin applied in mice, rats and rabbits. Results were obtained as follows; In 2 days after paraquat administration clinical signs anorexia, depression, tachypnea, and tachycardia, respiratory failure, coma and death were observed in mice, rats and rabbits. Compared toxicity of paraquat with mouse were observed toward to paraquat that resistance was strong than rats and rabbits. Also, mortality of skin application were found the low than intraperitoneal and high than oral administration. In the case of gross observation were appear lips moisture in orally administered rats and rabbits by skin application. Lung of all laboratory animals were observed congestion and haemorrhage, swelling or atrophy. In the case of microscopic findings were severe congestion and haemorrhage, interstitial pneumonia of lung. Congestion and haemorrhage of liver, congestion and haemorrhage, renal tubule epithelium necrosis of kidney were observed in mice, rats and rabbits. Skin application group of mice, rats and rabbits showed infiltration of inflammatory cells and folliculitis of epidermis and dermis. Also, in oral administration group showed congestion and haemorrhage, tachment, necrosis of alimentary tract mucosa.

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A Case Study on the Design of Drilled Shaft on Soft Ground in Vietnam (베트남 연약지반에서의 현장타설말뚝 설계 사례)

  • Seo, Won-Seok;Cho, Sung-Han;Choi, Ki-Byung
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.591-604
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    • 2008
  • In this study, two design examples of drilled shafts on soft ground in Ho-Chi-Minh City, Vietnam are introduced. One is for a 27-story apartment and the other is for a Arch bridge over Saigon river. Unlikely the normal cases in Korea, all of the bored pile foundations are supposed to be placed on soil layers. Therefore, skin friction between pile and ground is the most crucial design parameter. Three methods using SPT N value of sandy soil -Korean Road Bridge Code(1996), Reese and Wright (1977), and O'Neill and Reese (1988)- were adopted to obtain an ultimate axial bearing capacity. In order to verify the calculated bearing capacity, 3 sets of static load test and a Osterberg Cell test were performed at an apartment site and a bridge site respectively. LRFD (Load Resistance Factored Design) method was compared with ASD (Allowable Stress Design) method. On application of ASD method, safety factor for skin friction was adopted as 2 or 3 while safety factor for end bearing was 3. The design bearing capacities from ASD method matched well with those from LRFD method when safety factor for skin friction was adopted as 2.

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Fabrication of Antimicrobial Wound Dressings Using Silver-Citrate Nanorods and Analysis of Their Wound-Healing Efficacy

  • Park, Yong Jin;Jeong, Jisu;Kim, Jae Seok;Choi, Dong Soo;Cho, Goang-Won;Park, Jin Seong;Lim, Jong Kuk
    • Journal of Integrative Natural Science
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    • v.12 no.2
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    • pp.47-57
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    • 2019
  • Staphylococcus epidermidis is well-known not only as an innocuous normal flora species commonly isolated from human skin, but also as an important bacterial species to keep skin healthy, because this species can protect the human skin from pathogenic microorganisms. However, S. epidermidis turns into a potential pathogen in damaged skin, because these bacteria can easily form a biofilm on the wound area and provide antimicrobial resistance to other microorganisms embedded in the biofilm. Thus, it is important to kill S. epidermidis in the early stage of wound treatment and block the formation of biofilms in advance. In the present study, hydrogel wound dressings were fabricated using polyvinyl alcohol/polyethylene glycol containing silver citrate nanorods, which have been proven to have strong antimicrobial activity, especially against S. epidermidis, and their wound-healing efficacy was investigated in vivo using a rat experiment.

The Influence of the Direction of Applied Load(Compression and Uplift) and the Diameter of the Pile on the Pile Bearing Capacity (하중 작용 방향(압축과 인발)과 말뚝의 직경이 말뚝 지지력에 미치는 영향)

  • 이명환;윤성진
    • Geotechnical Engineering
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    • v.7 no.3
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    • pp.51-64
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    • 1991
  • The reliable estimation of pile bearing capacity is essential for the improvement of the re- liability and the cost-effectiveness of the design. There have been numerous pile bearing capacity prediction methods proposed up to now, however, execpt for the estimation made from the result of the pile loading test, not one method is appropriate for the reliable prediction. Due to the considerable time and expenses required to carry out the pile loading test, the test has seldom been utilized. The development of Simple Pile Loading Test(SPLT) which utilizes the pile skin friction as the required reaction force to cause the pile tip settlement, provides a solution to perform more pile loading tests and consequently a more economical pile design is possible. The separate measurement of skin friction and tip resistance during the course of performing SPLT provides a better understanding of the pile behavior than the result of the conventional pile loading test where only the total resistance is measured. On the other hand, there are some points to be clarified in order to apply the test results of SPLT to practical problem. They are the direction of the applied load to mobilize the skin friction and the use of reduced sized sliding core. In this research, both the SPLT and the conventional pile loading test on 406mm diameter steel pipe pile have been performed. From the result, it would be safe to use the measured SPLT skin friction value directly in the design, since the value is somewhat lower than the value measured in the conventional test. It is further assumed that the tip resistance value of the reduced sized sliding core should properly be analysed by taking the incluonce of scale effect into consideration.

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A Study on the Synthesis and Properties of Water-Dispersion Polyurethane for Garment Coating Using Nonionic Polyol (비이온 폴리올을 이용한 Garment 코팅용 수분산 폴리우레탄의 합성 및 물성에 관한 연구)

  • Lee, Joo-Youb
    • Journal of the Korean Applied Science and Technology
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    • v.34 no.1
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    • pp.83-90
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    • 2017
  • The polyurethane resin used for the garment skin leather surface coating was synthesized by varying the content of polyethylene glycol (PEG) in [NCO] / [OH] mole % ratio. The mechanical properties of the synthesized polyurethane resin were analyzed by SEM, FT-IR, UTM. As the [NCO] / [OH] mole % ratio of nonionic poly ethylene glycol (PEG) increased, there was no change in flexural resistance (dry, wet) and abrasion resistance and tensile strength measurement value were lowered. In contrast, the elongation property values were increased. The result of viscosity measurement showed that the viscosity became thinner with increasing [NCO] / [OH] mole % of PEG.

Development of Design Method of Compression(SSC) Anchor (압축헝 앵커의 설계법 개발)

  • 임종철;홍석우;이태형;이외득
    • Journal of the Korean Geotechnical Society
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    • v.15 no.1
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    • pp.63-78
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    • 1999
  • For the design of compression anchor, three things should be considered. The first is a resistance force by skin friction, the second is a tension strength of tendon, and the third is a compressive strength of grout. Especially, compressive strength of grout is the most important design parameter of compression anchor. When compression anchor is pulled out from the ground, the compressive strength of grout increases by confining pressure of ground($\sigma_{tg$). Here, $\sigma_{tg$ is the confining pressure which is produced by earth pressure at rest and by lateral expansion of grout. We call this phenomenon of increase of confining pressure "poisson effect". In this paper, the design method of compression anchor called SSC anchor and the computer program for the design are developed through compression tests of anchor body grout.ody grout.

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