• Title/Summary/Keyword: artificial aging treatment

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Monitoring system technology of patients' lifestyles

  • Hahn, James
    • Korean Journal of Artificial Intelligence
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    • v.2 no.1
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    • pp.4-6
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    • 2014
  • These days, aging, the aged and patients rapidly increased to produce problems, for instance, rapid increase of demand on medical service, higher medical expenses, low quality of the elderly's lives, shortage of physicians and nurses, and others [1]. These days, not only IT technology but also medical technology has taken the lead in settlement of the problems. Patients see a doctor to be given medical treatment and service when they are sick to have difficulty. The study investigated lifestyle monitoring system of chronic disease patients to indicate variation depending upon time. The health care is likely to solve problems of the elderly and chronic disease patients and to satisfy desire of better life quality by living healthy life and to diagnose diseases and give medical treatment and to give solutions in accordance with changes of paradigm of medical services.

A Study on the Fracture Toughness of Al-Si-Cu-Mg Cast Alloy (주조용(鑄造用) Al-Si-Cu-Mg계(系) 합금(合金)의 파괴인성(破壞靭性)에 관한 연구(硏究))

  • Ma, Dong-Jun;Kang, In-Chan
    • Journal of Korea Foundry Society
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    • v.7 no.2
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    • pp.114-121
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    • 1987
  • In order to determine the plane strain fracture toughness of Al-Si-Cu-Mg alloy castings, solution heat treatments have been conducted at $530^{\circ}C$ for 8hr and aged for 10hr at $145^{\circ}C$, $160^{\circ}C$ and $175^{\circ}C$. Effects of aging treatment and of Si contents on the fracture toughness have been investigated by a three point loaded bend test, using the artificial notch. The results obtained are as follows; 1) The fracture toughness is appreciably affected by the aging treatment temperature and Si contents. The specimen aged for 10hr at $145^{\circ}C$ has the highest fracture toughness. 2) Increasing Si contents from 5% to 9% results in decrease of fracture toughness. 3) Increasing the aging temperature and Si contents, C.O.D. value was decreased. The specimen aged for 10hr at $145^{\circ}C$ has the highest C.O.D. value. 4) Dimple patterns were observed in the specimens of containing under 7% Si, while mixed cleavage-dimple patterns in those of over 8% Si.

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The Change of Physical Properties of Artificial aging Paper in the Cleaning Process for the Conservation Treatment of Historical Paper Documents - Focusing on Immersion Wet Cleaning - (고문헌 보존처리의 클리닝 방법에 따른 인공열화지 물성 변화 - 침적 습식클리닝을 중심으로 -)

  • Jeong, Seon Hwa;Cho, An Naa
    • Korean Journal of Heritage: History & Science
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    • v.46 no.1
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    • pp.228-237
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    • 2013
  • Paper relics are affected by a number of complex physical, chemical, biological and artificial damaging factors due to the vulnerability of organic materials. Wet cleaning is a conservation treatment method for removing pollutants from paper artefacts. This study was carried out in order to analyse the effect of wet cleaning on Hanji (Traditional Korean paper made from mulberry trees) which is the main material used in Korean paper relics (historical paper documents). For this study, the color change and folding endurance of artificially degraded paper was analysed before and after immersion wet cleaning. The result showed that washing each twice in 30 minutes is the most appropriate method for obtaining cleaning efficiency and material stability.

Leakage of Seed Reserve Nutrient in Artificially Aged Pepper Seeds and Enhancement of Seed Vigor by Priming (노화처리된 고추종자의 저장성분 누출과 priming 처리가 종자활력 증진에 미치는 영향)

  • Kang Jum-Soon;Choi In-Soo
    • Journal of Life Science
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    • v.16 no.2 s.75
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    • pp.352-356
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    • 2006
  • Quantity of protein, amino acid, and sugar leaked from seeds was greater as the viability of seeds was dropped by the time elapsed of seed aging treatment. In the seeds with the artificial aging treatment for 20 days, 35.8 mg of protein was leaked on the 4th day after soaking, which was 6.9 times higher than that of control. Leakage of amino acid was also higher from low quality seeds treated with the aging treatment. In the seeds with the aging treatment for 20 days, $36.5{\mu}g$ fig of sugar was leaked on the 4th day after soaking, which was 2.8 times higher than that of control. The leakage of inorganic compound was higher from the low quality seeds, and leakage of total protein, amino acid, and sugar. According to .the quantity of leakage, water soluble compounds, which can be used for the assessment of seed quality without any destruction, were protein and potassium. Germination rate and percentage of seeds were dropped with the seed aging treatment, and the seed viability could be recovered by priming treatment. This phenomenon was very clear when the low quality seeds were germinated at low temperature.

Evaluation of Ultrasonic Nonlinear Characteristics in Artificially Aged Al6061-T6 (인공시효된 Al6061-T6의 초음파 비선형 특성 평가)

  • Kim, Jongbeom;Lee, KyoungJun;Jhang, Kyung-Young;Kim, ChungSeok
    • Journal of the Korean Society for Nondestructive Testing
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    • v.34 no.3
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    • pp.220-225
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    • 2014
  • Generally, the nonlinearity of ultrasonic waves is measured using a nonlinear parameter ${\beta}$, which is defined as the ratio of the second harmonic's magnitude to the power of the fundamental frequency component after the ultrasonic wave propagates through a material. Nonlinear parameter ${\beta}$ is recognized as an effective parameter for evaluating material degradation. In this paper, we evaluated the nonlinear parameter of Al6061-T6 which had been subjected to an artificial aging heat treatment. The measurement was using the transmitted signal obtained from contact-type transducers. After the ultrasonic test, a micro Vickers hardness test was conducted. From the result of the ultrasonic nonlinear parameter, the microstructural changes resulting from the heat treatment were estimated and the hardness test proved that these estimates were reasonable. Experimental results showed a correlation between the ultrasonic nonlinear parameter and microstructural changes produced by precipitation behavior in the material. These results suggest that the evaluation of mechanical properties using ultrasonic nonlinear parameter ${\beta}$ can be used to monitor variations in the mechanical hardness of aluminum alloys in response to an artificial aging heat-treatment.

Material Degradation in KS D 3503 SS400 Rolled Steel at $179^{\circ}C$ (KS D 3503 SS400 압연강 $179^{\circ}C$에서의 재질열화 연구)

  • Baek, Un-Bong;Park, Jong-Seo;Nahm, Seung-Hoon
    • Journal of the Korean Society of Safety
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    • v.21 no.4 s.76
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    • pp.13-18
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    • 2006
  • In spite of frequent defect in industrial boilers, life assessment or diagnostic method for them has not been actively studied. In this research, SS400 carbon steel used in industrial boilers is simulated with artificial aging heat treatment. To do qualitative life assessment, differences in micro-structures and hardness of SS400 by the degradation time are studied. In addition, variation in material properties by aging was observed with the tensile test at room temperature and $179^{\circ}C$ and changes in ductile to brittle transition temperature was observed with the charpy impact test performed at several test temperature.

Evaluation of degradation in aged 2.25CrMo steel by electrical resistivity, magnetic Barkhausen noise and carbide analysis (전기비저항, 바크하우젠노이즈 및 탄화물 분석법을 이용한 2.25Cr-1Mo 강의 열화도 평가)

  • Byeon, Jai-Won;Pyo, S.W.;Kwun, S.I.
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.210-215
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    • 2001
  • The ferritic 2.25CrMo steel has been used for high temperature structure applications such as turbine rotors, boilers and pressure vessels in fossil plant and petroleum chemical facilities. However, this steel is known to result in aging degradation due to temper embrittlement, carbide induced brittleness and softening of matrix after long time exposure to high temperature. This research investigated the microstructural and mechanical changes after artificial degradation treatment and evaluated the degree of degradation by several nondestructive methods. The decrease of electrical resistivity and increase of magnetic Barkhausen noise(RMS voltage) with increasing aging time were observed. The change of electrical resistivity and Barkhausen noise showed a good correlation with the ductile-brittle transition temperature.

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Applicability of Color Bituminous Mixtures for Highway Pavement (차도용 칼라 역청 혼합물의 적용성 연구)

  • Doh, Y.S.;Oh, S.K.;Choi, Y.K.;Kim, K.W.
    • International Journal of Highway Engineering
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    • v.6 no.4 s.22
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    • pp.91-100
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    • 2004
  • This study was Performed to evaluate applicability of color flexible pavement concrete (CFPC) for motorway pavement. Color flexible pavement has been applied to non-motorway pavements, such as pedestrian and bicycle road. Two polymers were used to modify the binder and to strengthen the stiffness of pavement mixture. Waste paper was used to prevent the asphalt of gap-grade mixture from draining. Marshall properties, indirect tensile strength(ITS), tensile strength ratio(TSR) before and after freezing-and-thawing treatment and artificial aging, permanent deformation and fatigue life were measured. Color bituminous concrete mixtures used this study had nearly the same quality in mechanical properties when compared with conventional asphalt concrete mixtures manufactured with AP-3 and all mixtures satisfied with domestic specification for motorway pavement. Therefore, it is proved that the color bituminous concrete used this study can be applied for motorway pavement.

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The Effect of Oxygen Absorbent on Aged Characteristics of Hanji during Biological Artificial Aging by Aspergillus versicolor and Penicillium polonicum (산소흡수제 처리가 Aspergillus versicolor와 Penicillium polonicum에 의한 한지의 생물열화 특성에 미치는 효과)

  • Jeong, Hye Young;Choi, Kyoung-Hwa;Park, Ji Hee;Seo, Jin Ho
    • 보존과학연구
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    • s.32
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    • pp.137-153
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    • 2011
  • Paper cultural heritages in museums and libraries are deteriorated by many biological factors like as fungi, insects, bacteria and rodents and get irreversibly damaged. Especially, paper components like as cellulose, hemicellulose, lignin, pectins, tannins, proteins and mineral additives are good nourishment for microorganism. Through some studies on fungi causing the aging of paper materials, Aspergilli (about 30%) and Penicilli (more than 30%) are the most common among 300 different kinds of microorganism that caused the biological aging of paper cultural heritages in museums and libraries. At present, various treatments are attempted to control the biodeterioration by these fungi. Especially, it is focused on the control of environmental factors such as humidity, temperature and oxygen. In this study, the oxygen absorbent was used to control oxygen, one of the these favorable conditions during the biological aging of Hanji by Aspergillus versicolor and Penicillium polonicum and then the effect on prevention in aging by this treatment was investigated. In result, the oxygen absorbent treatment had the good effect on prevention in aging during the biological aging by two species of fungi.

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Evaluation of Marginal and Internal Integrity of Modified Resin-Bonded Fixed Partial Dentures: An In Vitro Study

  • Ahn, Sung-Hyeon;Choi, Jae-Won;Jeon, Yong-Chan;Jeong, Chang-Mo;Yoon, Mi-Jung;Lee, So-Hyoun;Huh, Jung-Bo
    • Journal of Korean Dental Science
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    • v.10 no.1
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    • pp.29-34
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    • 2017
  • Purpose: The purpose of this study was to evaluate the microleakage of various types of resin-bonded fixed partial dentures (RBFPDs) after artificial aging. Materials and Methods: Forty models with missing first molar were fabricated using artificial resin teeth and were divided into four groups: Group A, conventional RBFPDs design; Group B, modified RBFPDs design; Group C, assembled 3-piece RBFPDs design; and Group D, assembled 3-piece RBFPDs with different occlusal rest positions. Half of the specimens underwent chewing simulation process (240,000 cycles, 50 N load, 1.7 Hz) and thermocycling (temperatures $5^{\circ}C{\sim}55^{\circ}C$, dwelling time 30 seconds) and the remaining 20 specimens didn't receive any treatment. All the specimens were immersed in 2% methylene blue solution for 24 hours to evaluate microleakage, and were sectioned at the middle part of abutment teeth. To evaluate the microleaskage, a dye penetration was calculated. Result: With artificial aging, cyclic loading and thermocycling, a 3-piece RBPFD and a 2-piece RBPFD using original tooth undercuts have significantly lower microleakge (P<0.05) compared to the conventional design of RBPFD and modified RBPFD. Conclusion: Within the limit of this experiment, the assembled RBFPDs exhibited a smaller microleakage than the conventional RBFPDs, implying that the assembled RBFPDs can be more effective for reducing the dislodgement of the RBFPDs.