• 제목/요약/키워드: Curl

검색결과 289건 처리시간 0.028초

글리세린 처리에 의한 종이의 물성 변화 (Effect of glycerine treatment on the properties of paper)

  • 박세진;차지영;김학상;김봉용
    • Current Research on Agriculture and Life Sciences
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    • 제24권
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    • pp.55-59
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    • 2006
  • This study was carried out to investigate the influence of glycerine on the properties of paper. Two types of glycerine treatment were used. First type, when making handsheets, glycerine was added in the plup slurry. Second type, copying paper was soaked in glycerine solution. Microwave treatment was used for the test of paper degradation. The obtained results were summarized as follows: 1. The glycerin was very effective to improve the property of softness. 2. The glycerine was helpful to increase sizing performance of paper as a fixing agent of sizing emulsion. 3. Curl tester was comparatively useful for the measuring of sizing degree.

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Seasonal Variation of Volume Transport through the Straits of the East/Japan Sea Viewed from the Island Rule

  • Seung, Young Ho;Han, Soo-Yeon;Lim, Eun-Pyo
    • Ocean and Polar Research
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    • 제34권4호
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    • pp.403-411
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    • 2012
  • Among others, a question that has long been unanswered is why the seasonal variation of volume transport is larger in the Soya and Korea/Tsushima Straits than in the Tsugaru Strait. An attempt is made to answer this question in terms of the island rule with friction being taken into account. The problem is idealized as a simple model. The model results indicate that volume transport through a channel is determined not only by the circulation created around the adjacent island but also by those created around the neighboring islands farther away. The latter is due to the presence of bottom friction in the channels. The volume transports through the Korea/Tsushima, Tsugaru and Soya Straits estimated from the model using observed wind data show the general pattern of observed seasonality, although they contain large errors associated with the uncertain frictional parameter employed in the model. The model indicates that the observed seasonality arises essentially from the fact that wind stress curl changes its sign, from negative in the summer to positive in winter, following a large fluctuation of zero-stress curl latitude east of Hokkaido.

도시 노인의 성별 및 연령별 기초신체활동 측정 평가 (Assessment of Basic Physical Activity According to Sex and Age Groups in Elderly Groups in an Urban Community)

  • 김소민;김대경
    • PNF and Movement
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    • 제16권2호
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    • pp.239-248
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    • 2018
  • Purpose: This study aimed to examine the elderly physical fitness test for elderly people living in urban areas and to evaluate the physical fitness level according to gender and age groups. Methods: The subjects were 180 elderly people aged 65 and over living in urban areas. The elderly people were classified into early old age, middle old age, and advanced old age groups. Five items of the physical fitness test for the elderly (arm curl, chair stand, 2 min step test, back scratch, and chair sit and reach). Results: In analyzing the average of each item by gender and age, a significant difference was found in the results of each item as age increased in all sports, but no difference was observed according to gender except dumbbell lifting. Conclusion: Although the physical fitness level of all ages decreased from early age to late age, the difference in physical fitness according to gender was not significant except the arm curl test. The results of this study can be used as basic data for a new "age-specific exercise program" for the elderly.

퍼머넌트 웨이브 시술방법에 따른 모발의 물리적·역학적 특성 변화 (The Change of Hair Physical and Mechanical Properties according to Permanent Wave Treatment Method)

  • 유태순;김정해;정연
    • 한국의류산업학회지
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    • 제8권4호
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    • pp.441-448
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    • 2006
  • This research is the hair damage as treating a permanent wave before and after that is compared and analyzed the change of physical and mechanical properties. This is the survey of women's hair in 20 years old. On the basis of this we would like to analyze a extend of hair damage. Also, we would to show a basic data for hair damage prevention and hair improvement to keep the beautiful and healthy hair. The conclusion is as follow. : The swelling degree after the treatment was found to be greater than before permanent wave treatment. For the formational characteristics wave, untreated hair certainly had more elastic S curl wave than damaged hair in all the permanent wave treatments, and damaged hair and extremely damaged hair had less elasticity and had saggy S curl wave. The protein permanent and soft permanent wave had thicker, gorgeous, and better elastic wave than the regular permanent wave and direct heating permanent wave in all the hair condition. As the degree of damage on hair got greater, the tensile strength dramatically decreased and as the degree of damage got greater, the elongation was great as well. For treatment method, direct heating permanent wave showed the greatest effect, causing the most damage.

크라프트 펄프 섬유의 다단 고해와 니딩 처리에 따른 종이 신장률 및 파괴인성의 변화 (Effects of Refining and Kneading of Kraft Pulp Fibers on Elongation and Fracture Toughness of Paper)

  • 임종혁;채희재;박창순;박종문
    • 펄프종이기술
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    • 제42권4호
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    • pp.39-44
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    • 2010
  • To increase the fracture toughness of paper made of Sw-BKP, refining and kneading conditions were analyzed. Curl and kink was known to increase the strain at break and the fracture touhness. Sequence of multiple stage beating, beating load and kneading were compared. When we applied a kneading treatment using a kneader at the final step, the most of the fiber transformation such as curl and kink occurred, the more the bulk and air-permeability improved. Physical strength and TEA(tensile energy absorption) were increased higher when kneading treatment before refining than only refining treatment was performed. TEA was increased because of higher elongation. It was found that the highest fracture toughness was obtained when applying the kneading treatment to the fibers in the pre-treatment step rather than in the middle step of beating or in the final step of beating.

탄소성 유한요소법을 이용한 금속인장교정기의 공정변수 설계 (Parametric Process Design of the Tension Levelling with an Elasto-plastic Finite Element Method)

  • 박상래;이형욱;허훈
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2000년도 추계학술대회 논문집
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    • pp.42-48
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    • 2000
  • This paper is concerned with a simulation-based process design for the tension levelling of metallic strips based on the elasto-plastic finite element analysis with reduced integration and hourglass control. The tension levelling process is performed to elongate the strip plastically in combination of tensile and bending strain by a controlled manner so that all longitudinal fibers in the strip have an approximately equal amount of length and undesirable strip shapes are corrected to the flat shape. The analysis deals with a method for calculating the quantitative level of the curl to investigate the roll arrangements and intermesh suitable to elimination of the curl. The analysis provides the information about the intermesh effect on the amount, the tension effect and distribution of the strain as well as the stress in order to determine the amount of elongation for correction of the irregular shape. The desired elongation is referred to determine the number of work rolls and the value of tension. Especially, the analysis investigates tile effect of the mesh size in the non-steady state finite element analysis on the amount and distribution of the strain.

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VLSI 인터커넥션에 대한 풀-웨이브 방법을 이용한 신호 왜곡 해석에 관한 연구 (A Study on the Signal Distortion Analysis using Full-wave Method at VLSI Interconnection)

  • 최익준;원태영
    • 대한전자공학회논문지SD
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    • 제41권4호
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    • pp.101-112
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    • 2004
  • 본 논문에서는 3차원 인터커넥트(3D interconnect) 구조를 해석하기 위하여 ADI-유한차분시간영역(ADI-FDTD: Alternating Direction Implicit Finite Difference Time Domain)법으로 맥스웰 회전 방정식(Maxwell's curl equation)을 계산하는 수치 해석 모델을 개발하였고, 개발한 ADI-유한차분시간영역법을 이용하여 3.3 V CMOS 기술로 설계된 샘플러 회로의 일부의 영역에 대해 컴퓨터 모의 실험 결과하여 입력된 구형 전압 신호가 금속 배선을 거치면서 5∼10 ps의 신호 지연과 0.1∼0.2 V의 신호 왜곡이 발생되는 것을 확인하였다. 결론적으로 ADI-유한차분시간영역법을 이용한 풀-웨이브 해석을 통하여 고속의 VLSI 인터커넥트에서의 전자기 현상을 정확하게 분석할 수 있음을 제시하였다.

스프링백 모드분류를 통한 박판 S-rail 성형공정의 형상정밀도 고찰 (Investigation of Shape Accuracy in the Forming of a Thin-walled S-rail with Classification of Springback Modes)

  • 정대근;김세호;김민석;이태길;김흥규
    • 소성∙가공
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    • 제22권8호
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    • pp.477-485
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    • 2013
  • This paper aims to evaluate quantitatively the springback characteristics that evolve in the sheet metal forming of an S-rail in order to understand the reasons of shape inaccuracy and to find a remedy. The geometrical springback is classified into six modes: angle change of punch and die shoulders, wall curl, ridge curl, section twist, and axial twist. The measuring method for each springback mode is suggested and quantitative measurements were made to determine the tendency towards shape accuracy. Forming experiments were conducted with four types of steel sheets that have different tensile strengths, which were 340MPa, 440MPa, 590MPa and 780MPa, in order to evaluate the effect of the tensile strength and the bead shape on the springback behavior. Springback tendencies show that they are greatly affected by the tensile strength of the sheet and the shape of the tools. Almost all springback modes except the section twist and the axial twist show a linearly increasing trend as the tensile strength of the sheet increases. The results can be used as basic data for design and for compensation of the press die geometry when forming high strength steels which exhibit large amounts of springback.