• Title/Summary/Keyword: Shock Absorbing System

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Development of nonwoven fabric and new adhesive system to manufacture hybrid corrugated board (농산물용 복합 골판지 제조를 위한 부직포 및 신규 접착시스템에 대한 연구)

  • Lee, Ji-Young;Yoon, Hee-Youl;Oh, Seok-Ju;Sung, Yong-Joo;Kim, Byeong-Ho;Lim, Gi-Baek;Choi, Jae-Sung;Kim, Sun-Young
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.44 no.3
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    • pp.49-55
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    • 2012
  • Even though corrugated boards are the most common packaging materials for agricultural products, conventional corrugated boards are not able to maintain the freshness of agricultural products. In order to overcome the limitations of conventional corrugated boards, a new hybrid corrugated board-composed of linerboard, a corrugating medium, and non-woven fabric-was designed to possess antibacterial, high porous and shock-absorbing properties. In this study, we compared the physical properties of non-woven fabric to those of the base papers of conventional corrugated boards and developed a new adhesive system as a first step toward manufacturing the hybrid corrugated board. We found that the non-woven fabric, which had relatively high elongation, was applicable in the corrugated board process, and that the manufacturing conditions must be controlled in order to prevent the break of the non-woven fabric. The mixture of starch and styrene-butadiene (SB) latex showed high adhesive strength, but the addition level of SB latex should not exceed 30% in starch solution.

Capture Simulation for Space Objects Using Biomimetic Space Nets (생체 모방 우주 그물을 이용한 우주 물체 포획 시뮬레이션)

  • Mi, Jang;Hyun-Cheol, Shin;Chang-Hoon, Sim;Jae-Sang, Park;Hae-Seong, Cho
    • Journal of Aerospace System Engineering
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    • v.16 no.6
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    • pp.24-34
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    • 2022
  • This paper investigates the capture of a 12U-sized CubeSat space object using a spider-web structure-based space net. The structural dynamics analysis program ABAQUS is used to simulate the shock-absorbing capability of the space net with a diagonal length of 2.828 m. The space object is modelled as a rigid body, and the space net is modelled using non-linear elastic beam elements. The simulations reveal that the spider-web structure-based space net outperforms the squared space net of the same structural weight in capturing the space object. The numerical simulations are conducted to examine the successful or unsuccessful captures of the space object in various cooperative and non-cooperative motions.

Effects of Visual Information Blockage on Landing Strategy during Drop Landing (시각 정보의 차단이 드롭랜딩 시 착지 전략에 미치는 영향)

  • Koh, Young-Chul;Cho, Joon-Haeng;Moon, Gon-Sung;Lee, Hae-Dong;Lee, Sung-Cheol
    • Korean Journal of Applied Biomechanics
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    • v.21 no.1
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    • pp.31-38
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    • 2011
  • This study aimed to determine the effects of the blockage of visual feedback on joint dynamics of the lower extremity. Fifteen healthy male subjects(age: $24.1{\pm}2.3\;yr$, height: $178.7{\pm}5.2\;cm$, weight: $73.6{\pm}6.6\;kg$) participated in this study. Each subject performed single-legged landing from a 45 cm-platform with the eyes open or closed. During the landing performance, three-dimensional kinematics of the lower extremity and ground reaction force(GRF) were recorded using a 8 infrared camera motion analysis system (Vicon MX-F20, Oxford Metric Ltd, Oxford, UK) with a force platform(ORG-6, AMTI, Watertown, MA). The results showed that at 50 ms prior to foot contact and at the time of foot contact, ankle plantar-flexion angle was smaller(p<.05) but the knee joint valgus and the hip flexion angles were greater with the eyes closed as compared to with the eyes open(p<.05). An increase in anterior GRF was observed during single-legged landing with the eyes closed as compared to with the eyes open(p<.05). Time to peak GRF in the medial, vertical and posterior directions occurred significantly earlier when the eyes were closed as compared to when the eyes were open(p<.05). Landing with the eyes closed resulted in a higher peak vertical loading rate(p<.05). In addition, the shock-absorbing power decreased at the ankle joint(p<.05) but increased at the hip joints when landing with the eyes closed(p<.05). When the eyes were closed, landing could be characterized by a less plantarflexed ankle joint and more flexed hip joint, with a faster time to peak GRF. These results imply that subjects are able to adapt the control of landing to different feedback conditions. Therefore, we suggest that training programs be introduced to reduce these injury risk factors.