• Title/Summary/Keyword: Physical shock protection

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A Study on the Wearing Status and Purchase Behavior of Sports Knee Braces (스포츠 무릎보호대의 착용 실태 및 구매 행동에 관한 연구)

  • Oh, Hee Kyung;Oh, Kyung Wha
    • Journal of the Korean Society of Clothing and Textiles
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    • v.45 no.2
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    • pp.253-270
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    • 2021
  • This survey provides research into developing knee braces to protect the knee against damage, reduce knee pain, and strengthen the knee. A total of 235 surveys were conducted from December 2019 to January 2020. The subjects were adults in their 20s and over who lived in the Seoul metropolitan area and had experience of using knee braces. In terms of age differences, subjects over 60 years of age purchased knee braces mostly to secure a reduction of pain (ROP), whereas subjects in their 20s and 30s purchased knee braces for physical shock protection (PSP). Subjects in their 40s and 50s purchased knee braces for improvement of muscle movement (IMM). There was no significant difference in shape, material, and locking method based on the reason for wearing the knee brace. These results show that it is conceivable and maybe preferable to produce different knee braces-with a variety of shapes, materials, and locking materials-according to the reason behind wearing a knee brace. Knee braces are worn currently without any differentiation despite the findings of this study. In particular, we argue the need for functional and differentiated development of knee braces specifically for PSP, ROP, and IMM.

Effects of Mixing Ratio of ONP and OCC on Physical Properties of Pulp Molds for Cushion Packaging Materials (완충포장소재를 위한 고지배합비율에 따른 펄프몰드의 물성 변화 연구)

  • Park, In-Sik;Kim, Jai-Neung;Kim, Dae-Yong;Lee, Youn-Suk
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.40 no.1
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    • pp.47-54
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    • 2008
  • As the demands of environment protection increases, the pulp mold container is developed to substitute for EPS (expanded polystyrene) as a shock absorbing packaging material. The water-absorbing ratio and mechanical properties such as tensile strength and compressive strength of pulp mold are important factors to evaluate its shock absorbing characteristics. Influences of mixing ratios of ONP (old newspaper) and OCC (old corrugated container) on physical properties of pulp mold were investigated at various conditions of temperature and relative humidity. The optimum mixing ratio of ONP and OCC was also searched based on physical properties. The results showed that when relative humidity was increased from 60% to 90%, the water absorption ratio of pulp mold increased significantly, tensile strength decreased 20$\sim$30%, and compressive strength decreased 10$\sim$20%. In addition, the optimum mixing ratio of ONP and OCC was found to be 50%:50%.

Analysis of sports knee brace products - Focusing on Chinese websites - (스포츠 무릎보호대 제품 분석 - 중국 웹사이트를 중심으로 -)

  • Xiaoqing Ma;Jeongah Jang
    • The Research Journal of the Costume Culture
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    • v.31 no.5
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    • pp.692-704
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    • 2023
  • This study analyzed 214 sports knee braces found on Chinese websites between October 2022 and November 2022 to assess product type (impact protection material, fastening method, and protection method), material composition, size, weight, and main characteristics. The product type was further categorized according to (1) use of hard guard and soft guard protection method; (2) cover type, strap type, and slip-on type fastening method; and (3) pressure type and support type protection method. It also noted the physical shock protection materials used, including foam (EVA or polyurethane) attached to joints as a buffer material and plastic (TPU or PP) that protects the user's knee from external impacts. The study found that the materials that primarily comprise sports knee braces are a combination of nylon, polyester, and neoprene. Additionally, it found that most sports knee braces available on the market are available in three sizes based on knee circumference: M (35-38cm), L (38-41cm), and XL (41-44cm), while some products are available in one size only. Furthermore, the majority of the 214 products studied weighed 200g, followed by 1,000g. Finally, in terms of product characteristics, many sports knee braces utilize ring-shaped silicone pads to distribute the load pressure on the knees or incorporate sturdy adhesive velcro to improve knee stability.

Performance Estimation of Hexagonal Rockfall Protection Net by Numerical Analysis (수치해석을 이용한 육각 낙석방지망의 성능 평가)

  • Oh, Sewook;Park, Soobeom;Kwon, Youngcheul
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.11
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    • pp.53-59
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    • 2014
  • It has been generally recognized that the conventional rockfall protection nets have several problems to actual field application in the aspect of shock absorption, lack of pullout bearing capacities, and net damages. Because of the recognition, authors have tried to develop a new rockfall protection system consisted of shock absorption parts and hexagonal net configuration. In the previous research by the authors, the performance of the newly developed rockfall protection system has been investigated through the laboratory tests and the full-scale testing. In this study, subsequently, numerical analysis program is organized to make a confirmation of the structural stability and performance. For the correct design procedure of the hexagonal net system, it is essential to understand the various mechanical behavior of the entire system. It is also important to be reproduced the systematic characteristics of the system acquired by laboratory and full-scale testing by numerical analysis in order to carry out the numerical experiment to understand various mechanical behavior of the system. As a conclusion, the hexagonal net has better performance in mechanical and physical behavior compared with that of the rectangular net. Furthermore, due to the hexagonal net shows a good performance in aspect of the load distribution, it gives a good alternative in long-term management of the rockfall protection net.

The Development of Pulp Mold Tray for Melon Packaging (멜론 포장용 펄프몰드 난좌 개발)

  • Choi, Seung Ryul;Jung, Hoon;Choi, Dong Soo
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.19 no.3
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    • pp.125-131
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    • 2013
  • In order to protect agricultural products against damage by physical load, various shock absorbing materials is used. As the demands of environment protection increase, the use of plastic materials have been restricted. On the other hand, Pulp mold products have some benefits - easy manufacturing, superior shock absorbing and eco-friendly. In order to develop pulp mold tray for melon packaging as shock absorbing packaging material, we investigated physical properties and vibration transmission characters of 180, 200 and 220 g pulp mold tray for melon. As the weight of pulp increased, compression strength and shock absorbing performance increased, while vibration transmissibility decreased. Especially in case of 180g pulp mold tray, it is not suitable for melon packaging because the transmitted vibration acceleration was higher than the forced vibration acceleration. And 200g pulp mold tray is suitable for melon packaging because the vibration transmissibility was lowest in three trays. And the vibration acceleration transmitted to the melon in edge of pulp mold tray was higher than to the melon in center of pulp mold tray. As the result of the simulated transportation test, the firmness of melon packaging using pulp mold tray was higher than that of conventional packaging. Therefore, these results suggest that pulp mold tray packaging could be suitable for melon packaging.

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Isolation and Characterization of Human scFv Molecules Specific for Recombinant Human Heat Shock Protein (HSP) 70.1

  • Baek, Hyun-jung;Lee, Jae-seon;Seo, Jeong-sun;Cha, Sang-hoon
    • IMMUNE NETWORK
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    • v.4 no.1
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    • pp.7-15
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    • 2004
  • Background: The heat shock proteins (HSPs) play an important role in cellular protection mechanisms against physical or chemical stresses. In this study scFv antibodies specific for human HSP70.1 were isolated from a semi-synthetic human scFv library with the ultimate goal of developing anti-HSP70.1 intracellular antibody (intrabody) that may offer an attractive alternative to gene targeting to study the function of the protein in cells. Methods: A semi-synthetic human scFv display library ($5{\times}10^{8}$ size) was constructed using pCANTAB-5E vector and the selection of the library against bacterially expressed recombinant human HSP70.1 was attempted by panning. Results: Three positive clones specific for recombinant HSP70.1 were identified. All three clones used $V_{H}$ subgroup III. On the other hand, $V_{L}$ of two clones belonged to the kappa light chain subgroup I, but the other utilized $V_{k}$ subgroup IV Interestingly, these scFv molecules specifically reacted to the recombinant HSP70.1, yet failed to recognize native HSP70 induced in U937 human monocytic cells by heat treatment. Conclusion: Our results indicated that affinity selection of an scFv phage display library using recombinant antigens produced in E. coli might not guarantee the isolation of scFv antibody molecules specific for a native form of the antigen. Therefore, the source of target antigens needs to be chosen carefully in order to isolate biofunctional antibody molecules.

Effect of Density Variation of High Tenacity PET Interlace Yarn on the Physical Properties of Pack Style Shock Energy Absorber (고강력 PET Interlace Yarn 밀도변화가 Pack Style Shock Energy Absorber의 물성에 미치는 영향)

  • Cho, Jin Won;Kwon, Sang Jun;Choe, Jong Deok;Kim, Sang Tae;Ji, Byung Chul;Yang, Seong Baek;Yeum, Jeong Hyun
    • Textile Coloration and Finishing
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    • v.27 no.2
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    • pp.132-141
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    • 2015
  • Fall-arrest systems(maximum arrest force and allowable free-fall) have been widely applied to provide a safe stop during fall incidents for various industrial activities. Fabric structure affects on the mechanical properties of shock energy absorber. The object of this study is to perform the basic research for the evaluation of the capacity of fall arrest energy absorber in relation to the different interlace yarn density. In this work, pack style energy absorber was prepared by weaving 10 types(Interlace yarn density used high tenacity PET 1000D : 60, 59, 58, 57, 56, 55, 54, 53, 52, 51). The paper presents the results of theoretical investigations of the performance of adjustable absorber during fall arrest. Dynamic load tests based on the EU fall protection equipment standard(CE : EN355:2002) were conducted. Results showed that the maximum arrest force by dynamic load test of energy absorber was satisfied with global standard(below 6,000N). Also, Maximum allowable free-fall of energy absorber showed below 1.75m.

Explosive loading of multi storey RC buildings: Dynamic response and progressive collapse

  • Weerheijm, J.;Mediavilla, J.;van Doormaal, J.C.A.M.
    • Structural Engineering and Mechanics
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    • v.32 no.2
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    • pp.193-212
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    • 2009
  • The resilience of a city confronted with a terrorist bomb attack is the background of the paper. The resilience strongly depends on vital infrastructure and the physical protection of people. The protection buildings provide in case of an external explosion is one of the important elements in safety assessment. Besides the aspect of protection, buildings facilitate and enable many functions, e.g., offices, data storage, -handling and -transfer, energy supply, banks, shopping malls etc. When a building is damaged, the loss of functions is directly related to the location, amount of damage and the damage level. At TNO Defence, Security and Safety methods are developed to quantify the resilience of city infrastructure systems (Weerheijm et al. 2007b). In this framework, the dynamic response, damage levels and residual bearing capacity of multi-storey RC buildings is studied. The current paper addresses the aspects of dynamic response and progressive collapse, as well as the proposed method to relate the structural damage to a volume-damage parameter, which can be linked to the loss of functionality. After a general introduction to the research programme and progressive collapse, the study of the dynamic response and damage due to blast loading for a single RC element is described. Shock tube experiments on plates are used as a reference to study the possibilities of engineering methods and an explicit finite element code to quantify the response and residual bearing capacity. Next the dynamic response and progressive collapse of a multi storey RC building is studied numerically, using a number of models. Conclusions are drawn on the ability to predict initial blast damage and progressive collapse. Finally the link between the structural damage of a building and its loss of functionality is described, which is essential input for the envisaged method to quantify the resilience of city infrastructure.

Mechanical Characteristics for Pulp Molds Made of ONP and OCC with Different Mixing Ratio (고지배합비율에 따른 펄프몰드 물성 변화 연구)

  • Park, In-Sik;Kim, Jae-Nung;Kim, Dae-Yong
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2007.04a
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    • pp.285-297
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    • 2007
  • As the demands of environment protection increase, the pulp mold container is developed to substitute for the plastic cushion materials like EPS(expanded poly styrene). The water-absorbing ratio, tensile strength and compressive strength of pulp mold are important factors to evaluate its shock absorbing characteristics. The study was performed to investigate the effects of the mechanical property changes on the various conditions of temperature and relative humidity for pulp mold containers made of mixed materials on ONP(old newspaper) and OCC(old corrugated container). This study also is evaluated the optimized mixing ratio of materials for making pulp mold by analyzing the changes of physical properties according to a various procured temperature and relative humidity conditions. The results show that the water absorption ratio of sample increased significantly, and tensile strength decreased $20{\sim}30%$, compressive strength decreased $10{\sim}20%$ by increasing relative humidity condition. And the results show that the ONP 50% and OCC 50% was optimized mixing ratio according to the samples.

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Transciptomic Analysis of Larval Fat Body of Plutella xylostella under Low Temperature (저온조건에서 배추좀나방(Plutella xylostella) 지방체 유전자 발현 변화)

  • Kim, Kwang-Ho;Lee, Dae-Weon
    • Korean Journal of Environmental Agriculture
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    • v.38 no.4
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    • pp.296-306
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    • 2019
  • BACKGROUND: Temperature is known to be the main factor affecting development, growth and reproduction of organisms and also a physical factor directly related to insect survival. Insects as ectothermal species should be responsive to climate changes for their survival and develop various survival strategies under the unfavorable temperature such as low temperature. The purpose of this study is to identify genes contributing to adaptation of low temperature. METHODS AND RESULTS: To identify genes contributing to adaptation of low temperature, the transcriptomic data were obtained from fat body in Plutella xyostella larvae via next generation sequencing. We identified structural proteins, heat shock proteins, antioxidant enzymes, detoxification proteins, and cryoprotectant mobilization and biosynthesis-related proteins. Genes encoding chitinase, cuticular protein, Hsp23, chytochrome protein, Glutathione S transferase, and phospholipase 2 were up-regulated under low temperature. Proteins related to energy metabolism such as UDP-glycosy ltransferase, trehalase and trehalose transporter were down-regulated. CONCLUSION: When insect pests were exposed to low temperature, changes in gene expression of fat body could provide some hints for understanding temperature adaptation strategies.