• Title/Summary/Keyword: Material screening

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A Screening Test of Extensibility and the Prediction of Clothing Pressure for Commercial Compression T-shirts (시중 컴프레션 티셔츠의 신장 특성에 대한 스크리닝 테스트와 의복압 예측)

  • Kim, Nam Yim;Hong, Kyunghi
    • Journal of the Korean Society of Clothing and Textiles
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    • v.41 no.6
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    • pp.1010-1021
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    • 2017
  • Adjustment of clothing pressure for compression wear is critical to the physiological and psychological satisfaction of the wearer; however, there are limited studies on the practical relationship among extensibility of materials, pattern reduction of compression wear and resultant clothing pressure. This study provides consumers and designers with information on clothing pressure using a screening extensibility test suggested by Ziegert and Keil (1988) even for the final products. As the first step, ten commercial products were collected and their size, extensibility and corresponding clothing pressure were analyzed. It was found that clothing pressure around the waist level could be predicted well from the information of Ziegert and Keil's (1988) % extensibility of the material (Z stretch %) and the actual application of Z stretch amount to the pattern reduction rate (applied % of Z stretch), with an $r^2$ of around 0.80, especially at the waist level. However, it was not simple for the case of clothing pressure around the back of the chest level due to the various design variation and the complexity of the anatomical structure around the trapezius.

Transport Velocity of Perilla Grain on Oscillating Sieve in Elliptical Motion

  • Pang, Yeoun Gyu;Kim, Sang Hun
    • Journal of Biosystems Engineering
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    • v.43 no.3
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    • pp.194-201
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    • 2018
  • Purpose: The objective of this study was to propose a formula for the theoretical grain mean transport velocities of an elliptically moving oscillator by modifying the grain mean transport velocity formula applied to linear motion and to compare the calculated values with the experimental values of grain mean transport velocity. Methods: The values of the throwing index ($K_v$) and the maximum horizontal velocities for various positions on the elliptical oscillator were obtained using kinematic analysis. To obtain the actual grain transport velocity, the mean transport velocities of perilla grains at six positions on the sieve surface were measured using a high-speed camera and compared with the theoretical values. The cam with an eccentric bearing on the oscillator was designed to be eccentric by 1.6 cm so that the lengths of the major axis of the elliptical motion were 3.2-3.6 cm. The material used in the experiments was perilla grain. Results: The experimental result was consistent with the theoretical value calculated using the proposed formula ($R^2$ is 0.80). It is considered that the angle difference between the maximum accelerations in the directions vertical and horizontal to the sieve has as much influence on the grain mean transport velocity as the value of Kv itself. Conclusions: It was possible to theoretically obtain the grain mean transport velocities through a screening device in elliptical motion by modifying the formula of the grain mean transport velocities used in linear motion.

Levitation characteristics of HTS tape stacks

  • Pokrovskiy, S.V.;Ermolaev, Y.S.;Rudnev, I.A.
    • Progress in Superconductivity and Cryogenics
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    • v.17 no.1
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    • pp.14-16
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    • 2015
  • Due to the considerable development of the technology of second generation high-temperature superconductors and a significant improvement in their mechanical and transport properties in the last few years it is possible to use HTS tapes in the magnetic levitation systems. The advantages of tapes on a metal substrate as compared with bulk YBCO material primarily in the strength, and the possibility of optimizing the convenience of manufacturing elements of levitation systems. In the present report presents the results of the magnetic levitation force measurements between the stack of HTS tapes containing $n=2{\div}200$ of tapes $12mm{\times}12mm$ and NdFeB permanent magnet in the FC and ZFC regimes. It was found a non- linear dependence of the levitation force from the height of the array of stack in both modes: linear growth at small thickness gives way to flattening and constant at large number of tapes in the stack. Established that the levitation force of stacks comparable to that of bulk samples. The numerical calculations using finite element method showed that without the screening of the applied field the levitation force of the bulk superconductor and the layered superconductor stack with a critical current of tapes increased by the filling factor is exactly the same, and taking into account the screening force slightly different.

Recovery and Refining Process of Gypsum from Waste Plaster Board

  • Song, Young-Jun;Hiroki Yotsumoto
    • Resources Recycling
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    • v.10 no.6
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    • pp.43-52
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    • 2001
  • This study was conducted to obtain granular crystalline gypsum that can be used as raw material for Plaster boards or cements from waste Plaster board. Gypsum could be Preferentially disintegrated to gypsum needle in $10\mu\textrm{m}$ or less size by hydration after the dehydration of crushed waste Plaster board. The finer the gypsum needle, it is easier to remove coarse impurities and to recover the gypsum needle. The optimum conditions for obtain the finer gypsum size were dehydration rate of 75~85%, solid concentration at hydration of 10~15%, agitation speed of 250~400 rpm, crushing size before dehydration of 2 cm or less. Gypsum of 98.21% grade was recovered with 99.0% yield as the undersize of 325 mesh wet screening followed by the dehydration-hydration process performed at the conditions of dehydration rate of 80%, solid concentration at hydration of 15%, agitation speed of 300 rpm, crushing size before dehydration of 2 cm or less. After the recrystallization of recovered gypsum, Plate-like gypsum of $151\mu\textrm{m}$ size with 99.49% grade was obtained as the oversize of 270 mesh in a wet screening.

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Studies in Impedance Audiometry on Neonates (신생아의 Impedance audiometry)

  • Oh, Pyung;Cheon, Kyung-Doo;Song, Jae-Woo;So, Jin-Myung
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1977.06a
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    • pp.4.2-4
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    • 1977
  • There are varying opinions about theories that the middle ear of Neonates is filled with mucous or other Material that interference with normal mobility of the middle ear system. DeDMon reported on the acoustic reflex as a tool for Neonatal screening, and Keith investigated the Middle ear function of Neonates during first few hours of life with an Electroacoustic impedance bridge. There are no reports on Neonstes in Impedance Audiometry in Korea. We tested 100 Neonates less than 24 hours old and this paper is dealt with its study related with tympanogram, static compliance and acoustic reflex.

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An Evaluation of Thermal Stability on Esterification Process in Manufacture of Concrete Mixture Agents (시멘트 혼화제 제조시 에스테르화공정의 열 안정성 평가)

  • Lee, Keun-Won;Lee, Jung-Suk;Choi, Yi-Rae;Han, In-Soo
    • Journal of the Korean Society of Safety
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    • v.24 no.4
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    • pp.40-46
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    • 2009
  • The early identification of thermal hazards associated with a process such as the heats of reaction, exothermic decompositions, and the understanding of thermodynamics before any large scale operations are undertaken. The evaluation of reaction factors and thermal behavior on esterification process in manufacture of concrete mixture agents are described in the present paper. The experiments were performed in the differential scanning calorimetry(DSC), C 80 calorimeter, and thermal screening unit($TS^u$). The aim of the study was to evaluate the thermal stability of single material and mixture in esterification process. We provided the thermal data of chemical materials to present safe operating conditions through this study.

Relationship between Sense of Belonging, Powerlessness and Nutritional status of Elderly People (노인의 소속감, 무력감과 영양 상태와의 관계)

  • Kim, Mi-Hye;Chung, Hae-Kyung
    • Journal of the Korean Society of Food Culture
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    • v.30 no.1
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    • pp.118-128
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    • 2015
  • This study was performed to analyze health problems in older adults in a comprehensive manner, including usual living habits, nutritional status, and society psychological factors. Research was conducted by a structured questionnaire by interviews with a test group of 316 people over the age of 65 from April 2012 to August 2012. Elderly people's dietary intake was assessed using NSI (Nutrition Screening Initiative) by the 24-hour retrospective method, and elderly people's feeling of helplessness and sense of belonging were assessed using the measuring device. Material analysis, descriptive statistics, and regression analysis were performed using SPSS. Elderly people with increased age showed higher chances of being in the high-risk and undernourished group. Elderly with high NSI showed low intake of fat, protein, fibrin, vitamin C, E, $B_1$, $B_2$, Niacin, K, Fe, Zn, and Cu than those with low NSI. Findings from this comparative analysis indicate that elderly with better nutritional status showed a lower feeling of helplessness than those with poor nutritional status. Overall, elderly people consumed a b road variety of foods, and social emotional stability of elderly people increased at optimal dietary levels.

A Cross-check of Domestic Lead Material Flow in Public Database Sets for the Recycling Status Analysis (재활용 현황파악을 위한 공공 자료별 국내 납 물질 흐름 상호 확인)

  • Lee, Sang-hun;Kim, Jungeun
    • Resources Recycling
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    • v.30 no.3
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    • pp.63-69
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    • 2021
  • Supply deficit of lead commodities and environmental pollution can be simultaneously resolved through the recovery and recycling of waste lead. The recent recovery of lead through recycling of the lead battery waste is a positive development. To maximize the effect of lead recovery and recycling in the future, the updated status of the lead material flow should be recognized. However, such an analysis at the preliminary stages may be cumbersome owing to the complexity and diversity of emission sources and material streams. At this stage, a preliminary screening by domestic lead flow using public information should be feasible. Therefore, in this study, using the data from the UN Comtrade and domestic PRTR (Pollutant Release and Transfer Register) databases, the amounts of lead import, emission, and transfer were identified and cross-checked with the domestic lead flow described in the National Material Flow Analysis database. The lead flow for major categories such as waste lead-acid batteries showed a rough consistency between the databases.

Development of Certified Reference Materials for Analysis of Heavy Metals in Paints to Cope with Environmental Regulations (환경규제 대응을 위한 페인트 중의 중금속 분석용 인증 표준물질 개발)

  • Yu, Byung Kyu;Sun, Yle Shik
    • Journal of Environmental Analysis, Health and Toxicology
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    • v.21 no.4
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    • pp.209-219
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    • 2018
  • In the areas of RoHS, WEEE, ELV and REACH, reinforcement of environmental regulations against harmful substances is a global trend not only in EC but also in all over the world. In the fields of Korea's major export products such as material parts, electrical and electronic products and automobile parts, we are responding to these regulations consistently. To develop reference material for analyzing lead and cadmium in paints, the candidate materials were produced through the screening process which separated shapes and sizes. To secure the traceability of the candidate materials produced, the characteristics and uncertainties are estimated by ICP-AES analysis using the primary reference material. The short-term and long-term stabilities also are evaluated in parallel. In order to calculate the final certification value of the candidate material, the verification were carried out by the performance evaluation through the comparison among the KOLAS (Korea Laboratory Accreditation Scheme) laboratories, and the CRM was produced in accordance with ISO Guide 35. The certified values and uncertainties of Pb and Cd of the final paint standard, determined according to the joint analysis among laboratories, are Pb [($191.4{\pm}3.1$) mg/kg, ($944.1{\pm}5.6$) mg/kg] and Cd [($45.0{\pm}2.6$) mg/kg, ($225.5{\pm}3.5$) mg/kg]. These standard materials were developed to enhance the reliability of measurement analysis, including the validity and traceability of measurement results. Also it is expected that the CRM will be used as QCM (quality control material) for the product design and the process monitoring, so that regulation and management of hazardous heavy metals can be systematically implemented.

Screening Methods for Plant-Coating Materials and Transpiration Inhibitory Effect of Soybean Oil to Crops (식물 코팅 소재 선발법과 작물들에 대한 콩 오일의 증산 억제 효과)

  • Jung, In Hong;Park, No Bong;Kim, Sang-Yeol;Na, Young-Eun;Kim, Soon-Il
    • Korean Journal of Plant Resources
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    • v.27 no.4
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    • pp.380-391
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    • 2014
  • Plants as well as crops are damaged by a combination of the hot and dry winds that has been a major factor in the reduction of crop production. A means to protect them from damaging conditions is to consider a coating material. In this study, we established laboratory screening methods to find a coating material to protect a crop from rapid transpiration caused by various factors. In a test measuring the weight loss of kidney bean seedlings for 6 days, Avion treatments decreased its weight loss (P=0.05). Owing to long-time spend in completing this assay, we performed a more simple method using a cobalt chloride paper strip, which changes from blue to red colors under water condition. Beewax, guagum, paraffin liquid, soybean oil, and PE-635 gave a waterproofing effect above 37 and 43% at 0.5 and 1 h after treatment, respectively. However, these tested materials did not show significant waterproofing results at 2 h. Although the methods produced reasonable results, a screening method to obtain more objective data is needed. An alternative is to use an instrument that can detect the transpiration of crop leaves. In a preliminary test using barley leaves, a portable photosynthesis system showed transpiration inhibition of 2% soybean oil and 10 times-diluted Avion under field conditions. In another test using the leaves of maize seedlings and apricot tree, 2% liquid paraffin and plant oils such as apricot oil, linseed oil, olive oil, and soybean oil showed significant transpiration inhibition (P=0.05). Especially, paraffin liquid and soybean oil selected from above tests gave good transpiration inhibitory effects against rice at 2%. In addition, the mixture of 2% soybean oil and a spreader showed more elevated inhibition results comparing with soybean oil or the spreader alone indicating that the spreader may be attributed to more uniform diffusion of the hydrophobic material onto the leaf surface of maize seedlings. The hydrophobic material coated physically the stomata and cuticle layers on leaf surfaces of rice. These hydrophobic materials screened in this study are expected to be used as plant coating materials.