• Title/Summary/Keyword: Human materials

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Manufacturing and Mechanical Properties of Epoxy Fibers Spinning using Anhydride and Amine Hardeners (산 무수물계 및 아민계 경화제를 이용한 열경화성 에폭시 섬유 제조 및 물성)

  • Shin, Pyeong-Su;Kim, Jong-Hyun;Park, Ha-Seung;Baek, Yeong-Min;Kwon, Dong-Jun;Park, Joung-Man
    • Composites Research
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    • v.29 no.6
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    • pp.408-413
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    • 2016
  • Commonly-used polymers are manufactured as versatile forms. Furthermore, continuous polymer fibers are recently manufactured using nylon or aramid fiber. One of common epoxy was also used to make polymer fibers. Bisphenol-A type was used as base epoxy whereas amine and anhydride were used as hardeners. Epoxy fibers was cured by stepping up the temperature to maintain the shape of epoxy fiber. Surface energy was measured to confirm the degree of interfacial adhesion by modified static contact angle method. After mechanical properties were measured via fiber tensile test, the evaluation of fiber fracture was proceeded. Tensile strength of epoxy fiber using amine type hardener was higher as 138 MPa than anhydride case as 70 MPa. Fractured surface exhibited different failure patterns at the cross-section.

An Analysis of Sexual Health Education for Korean Adolescents (청소년대상 영상매체 성교육자료분석 -비디오를 중심으로-)

  • Lee, Koang-Ok;Yang, Soon-Ok;Im, Mi-Lim
    • Research in Community and Public Health Nursing
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    • v.9 no.2
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    • pp.441-457
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    • 1998
  • The purpose of this study is to provide fundamental information for the development of new sex education image media through the analysis of those tools produced by Planned Parenthood Federation of Korea. Twenty three video tapes related to the sex education were analysed. The data were sampled on the basis of the sex education instructions for primary and secondary schools published by the Seoul Office of Education in 1996 and the list of sex education information composed by the Planned Parenthood Federation of Korea with the following requirements. 1) The education materials are oriented to the middle and high school students as well a juveniles and are being used in public health centers and schools. 2) The education materials are not confined to the single subject such as AIDS or contraception. Because this study is focused on the analysis of image media, an analysis method widely and effectively used in public media study was chosen. The frequency analysis and percentage treatment were done by an SAS program. The results of the study are as follows : 1. An analysis of the material structure type showed that the frequency of the following subjects in 15 video tapes, composed as drama and cartoon, had this decreasing orde : sex behavior, sex relation ships, sex health, human development, personal technique, and society and culture. 2. The eight tapes of explanation and counseling showed a different sequence from that of the drama and cartoon material, primarily treating human development with 5419 seconds (47.9%) of type. The following were also considered in decreasing order: at 2000seconds (17.6%) sex behavior, at 1366 seconds (12.1%) sex health, at 1240 seconds (11.0%) society and culture, at 667 seconds (6.0%) relation ships, and at 611 seconds (5.4%) personal technique. 3. In a thematic analysis those education materials dealing with human development show this frequency sequence: anatomic physiology, reproduction, and adolescence. In relation, ships the sequence is dates, love, marriage and vows, and family. For personal technique, it is expressed as asking for help, and an empnasis on moral values. For sex behavior, they focus on abstinence, the co-responsibility of sex behavior, the sexual response of the human, and sexual nightmares. For the sex health area, the focus is contraception with abortion and reproductive health following that. In society and culture diversity is considered. 4. An analysis of the differences in production and content between 1980s and 1990s was also done. For materials produced in the 1980s the frequency of the subjects follows this order: sex behavior, human development, relation ships, sex health, personal technique, and society and culture with sub subjects such as abstinence, dating, adolescence, anatomic physiology, reproduction, calls for help, and the sexual response of a human being. For materials produced in the 1990s, highest frequency was sex behavior, the same as the 1980s. The rest of the material follows this decreasing order: relationships, human development, sex health, society and culture, and personal technique with sub subjects such as dating, co-resposibility in sex behavior, abstinence, and love frequently considered.

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Glucose Sensing Properties of Electrospinning-Synthesized ZnO Nanofibers (전기방사로 합성된 산화아연 나노섬유의 Glucose 감응특성)

  • Choi, Jong-Myoung;Byun, Joon-Hyuk;Kim, Sang Sub
    • Korean Journal of Materials Research
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    • v.25 no.12
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    • pp.655-658
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    • 2015
  • The development of glucose biosensors has been attracting much attention because of their importance in monitoring glucose in the human body; such sensors are used to diagnose diabetes and related human diseases. Thanks to the high selectivity, sensitivity to glucose detection, and relatively low-cost fabrication of enzyme-immobilized electrochemical glucose sensors, these devices are recognized as one of the most intensively investigated glucose sensor types. In this work, ZnO nanofibers were synthesized using an electrospinning method with polyvinyl alcohol zinc acetate as precursor material. Using the synthesized ZnO nanofibers, we fabricated glucose biosensors in which glucose oxidase was immobilized on the ZnO nanofibers. The sensors were used to detect a wide range of glucose from 10 to 700 M with a sensitivity of $10.01nA/cm^2-{\mu}M$, indicating that the ZnO nanofiber-based glucose sensor can be used for the detection of glucose in the human body. The control of nanograins in terms of the size and crystalline quality of the individual nanofibers is required for improving the glucose-sensing abilities of the nanofibers.

Method of Object Identification Using Joint Data of Multi-Joint Robotic Gripper for Bin-picking (빈-피킹을 위한 다관절 로봇 그리퍼의 관절 데이터를 이용한 물체 인식 기법)

  • Park, Jongwoo;Park, Chanhun;Park, Dong Il;Kim, DooHyung
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.25 no.6
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    • pp.522-531
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    • 2016
  • In this study, we propose an object identification method for bin-picking developed for industrial robots. We identify the grasp posture and the associated geometric parameters of grasp objects using the joint data of a robotic gripper. Prior to grasp identification, we analyze the grasping motion in a low-dimensional space using principle component analysis (PCA) to reduce the dimensions. We collected the joint data from a human hand to demonstrate the grasp-identification algorithm. For data acquisition of the human grasp data, we conducted additional research on the motion characteristics of a human hand. We explain the method for using the algorithm of grasp identification for bin-picking. Finally, we present a subject for future research using our proposed algorithm of grasp model and identification.

In vitro Skin Irritation Test of Honeypolis using Human Skin Model

  • Woo, SoonOk;Han, Sangmi;Hong, Inpyo;Kim, Sung-kuk
    • Journal of Apiculture
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    • v.33 no.4
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    • pp.277-282
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    • 2018
  • Ethanol extracted propolis (EEP) was mixed with honey (honeypolis) to dissolve well in water and in vitro skin irritation test was conducted. In vitro method is designed to predict and classify the skin irritation potential of a chemical by assessment of its effect on $EpiDerm^{TM}$, a reconstituted three-dimensional human epidermis model. Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from MTT after a 60 min exposure period. In this study under the given conditions honeypolis showed no irritant effects. Honeypolis meets acceptance criteria if: mean absolute OD 570 nm of the three negative control tissues is ${\geq}0.8$ and ${\leq}2.8$, mean relative tissue viability of the three positive control tissues is ${\leq}20%$, standard deviation of relative tissue viability obtained from each three concurrently tested tissues is ${\leq}18%$. Honeypolis is therefore classified as "non-irritant" in accordance with UN GHS "No Category".

Epoxy Matrix with Adding Dopamine for Improving Mechanical Property and Interfacial Adhesion with Glass Fiber (도파민이 첨가된 에폭시 기지재의 기계적 물성 및 유리섬유 간 계면접착력 향상)

  • Shin, Pyeong-Su;Kim, Jong-Hyun;Baek, Yeong-Min;Park, Ha-Seung;Park, Joung-Man
    • Composites Research
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    • v.32 no.2
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    • pp.96-101
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    • 2019
  • Interfacial adhesion between fiber and resin are related to composites performance, so it is very important to evaluate them accurately. In this study, the interfacial properties of microdroplets under fatigue loading conditions were evaluated. The mechanical properties and interfacial adhesion of epoxy resin with dopamine were studied. Tensile specimens were prepared to evaluate mechanical properties and epoxy microdroplets specimens were used for the evaluation of interfacial adhesion. In addition, in the microdroplet fatigue test, the same diameter of the microdroplet was used and the experiment was performed under the same conditions. As a result, it was confirmed that mechanical and interfacial properties were improved when dopamine was applied to epoxy resin through tensile and microdroplet experiments. It is considered that dopamine improves the degree of curing of the epoxy resin and imparts hydroxyl groups to the epoxy resin to increase the mechanical properties and the interfacial adhesion between the glass fibers.

Design of High Payload Dual Arm Robot with Replaceable Forearm Module for Multiple Tasks: Human Rescue and Object Handling (임무에 따른 하박 교체형 고 가반하중 양팔로봇의 설계: 구난 및 물체 핸들링)

  • Kim, Hwisu;Park, Dongil;Choi, Taeyong;Do, Hyunmin;Kim, Doohyeong;Kyung, Jinho;Park, Chanhun
    • The Journal of Korea Robotics Society
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    • v.12 no.4
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    • pp.441-447
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    • 2017
  • Robot arms are being increasingly used in various fields with special attention given to unmanned systems. In this research, we developed a high payload dual-arm robot, in which the forearm module is replaceable to meet the assigned task, such as object handling or lifting humans in a rescue operation. With each forearm module specialized for an assigned task (e.g. safety for rescue and redundant joints for object handling task), the robot can conduct various tasks more effectively than could be done previously. In this paper, the design of the high payload dual-arm robot with replaceable forearm function is described in detail. Two forearms are developed here. Each of forearm has quite a different goal. One of the forearms is specialized for human rescue in human familiar flat aspect and compliance parts. Other is for general heavy objects, more than 30 kg, handling with high degree of freedom more than 7.

Bio-applicable Ti-based Composites with Reduced Image Distortion Under High Magnetic Field (높은 자장하에서 자기공명 영상 왜곡이 완화된 생체용 Ti 복합재료)

  • Kim, Sung-Chul;Kim, Yu-Chan;Seok, Hyun-Kwang;Yang, Seok-Jo;Shon, In-Jin;Lee, Kang-Sik;Lee, Jae-Chul
    • Korean Journal of Metals and Materials
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    • v.50 no.5
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    • pp.401-406
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    • 2012
  • When viewed using a magnetic resonance imaging (MRI) system, invasive materials inside the human body, in many cases, severely distort the MR image of human tissues. The degree of the MR image distortion increases in proportion not only to the difference in the susceptibility between the invasive material and the human tissue, but also to the intensity of the magnetic field induced by the MRI system. In this study, by blending paramagnetic Ti particles with diamagnetic graphite, we synthesized $Ti_{100-x}C_x$ composites that can reduce the artifact in the MR image under the high-strength magnetic field. Of the developed composites, $Ti_{70}C_{30}$ showed the magnetic susceptibility of ${\chi}=67.6{\times}10^{-6}$, which corresponds to 30% of those of commercially available Ti alloys, the lowest reported in the literature. The level of the MR image distortion in the vicinity of the $Ti_{70}C_{30}$ composite insert was nearly negligible even under the high magnetic field of 4.7 T. In this paper, we reported on a methodology of designing new structural materials for bio-applications, their synthesis, experimental confirmation and measurement of MR images.