• 제목/요약/키워드: Aging effects

검색결과 2,134건 처리시간 0.028초

촉매의 열화에 관한 연구 I (Study I of Catalyst Aging)

  • 손건석;이지연;이귀영;최병철
    • 한국자동차공학회논문집
    • /
    • 제5권3호
    • /
    • pp.86-94
    • /
    • 1997
  • Quick aging of catalysts has done with IAE(Institute for advanced engineering) AGING MODE suggested by IAE. To estimate the effects of number of aging cycle, temperature and $H_2O$, characteristics of surfaces, mechanical properties and weibull modulus were estimated. Also, the conversion efficiency of aged catalysts was evaluated with model gas bench test. The area of surface and pore volume were decreased according to the number of aging cycle. The precious metal which is well dispersed in fresh state was sintered and agglomerated with aging. The mechanical of deactivation and sintering of catalysts are discussed on the basis of mechanical tests. The conversion efficiency was decreased with the repeats of aging. Especially, the existence of $H_2O$ in supply gas had a main role in catalyst deactivation withy high temperature.

  • PDF

Degradation of Epoxy Coating due to Aging Acceleration Effects

  • Nah, Hwan Seon;Lee, Chul Woo;Suh, Yong Pyo
    • Corrosion Science and Technology
    • /
    • 제5권3호
    • /
    • pp.99-105
    • /
    • 2006
  • This paper is to investigate feasibility on quantitative aging state of epoxy coating on concrete wall in containment structure under operation of nuclear power plants. For evaluating the physical characteristics of the epoxy coating, adhesion strengths of two kinds of degraded epoxy coating systems on both steel surfaces and concrete surfaces were measured via accelerated aging. Comparatively impedance data taken by ultrasonic test were also taken to relate with adhesion data. After aging, in case of concrete, from half of specimens, aging of epoxy coating was developed. As for steel, on $4^{th}$ inspection day, adhesion force was failed. To improve reliability on quality degradation of epoxy, relationship between adhesion and impedance was analyzed. By tracing to co-respond to these data, it was possible to Fig. out physical state of as-built epoxy coating. The possibility to develop new methodology of time - dependent aging state on epoxy coating was found and discussed.

A 6061 합금의 기계적 특성에 미치는 2단시효의 영향 (Effects of Two-Step Aging Treatment on the Mechanical Properties of 6061 Al Alloy)

  • 이보배;임항준;정걸채
    • 열처리공학회지
    • /
    • 제32권2호
    • /
    • pp.57-60
    • /
    • 2019
  • The impact of two-step treatment on the mechanical properties of the 6061 Al alloy was investigated by testing the hardness and electrical conductance values. After two-step aging treatment, the hardness and electrical conductivity of the alloy was increased, and if the first aging treatment temperature was lower than the secondary aging treatment temperature, both the hardness and the electrical conductivity were not increased. The higher the temperature of the first aging treatment, the higher the hardness. The temperature of the first aging treatment is $175^{\circ}C$, $150^{\circ}C$, $120^{\circ}C$, and the second is $175^{\circ}C$ and $120^{\circ}C$.

Efficacy Evaluation of Anti-wrinkle Products in Japan

  • Masaki Hitoshi
    • 대한화장품학회지
    • /
    • 제29권2호
    • /
    • pp.67-77
    • /
    • 2003
  • Two categories of cosmetic products, cosmetics and quasi-drugs, have been established by the Ministry of Health, Labor and Welfare (MHLW) in Japan. Japanese pharmaceutical law has defined that products categorized as cosmetics do not exhibit any effects on human skin. In fact, cosmetic products are not permitted to claim any efficacy. On the other hand, products in the quasi-drug category can claim several efficacies such as anti-inflammatory effects, whitening/lightning effects, hair growth effects and so on. Unfortunately, the Japanese MHLW has not yet approved the efficacy of anti-aging/anti-wrinkle effects as a claim point. However, the population is aging, and the demand for anti-aging/anti-wrinkle products is increasing year by year. Japanese cosmetic companies have proposed to the MHLW that anti-aging/anti-wrinkle agents be approved as a claim concept of a quasi-drug. However, unified evaluation methods for anti-aging/anti-wrinkle effects have not been established. Currently, each company evaluates the efficacy of products/materials using their own original methods. Thus, to request approval of the MHLW, the establishment of a unified evaluation method is needed. Consequently, the Japan Cosmetic Industry Association (JCIA) has established a task force to develop guidelines for evaluating anti-wrinkle effects in 1998. In conclusion, the JCIA would like to adopt visual and image analysis scales to evaluate the anti-wrinkle effects objectively. Generally, wrinkles are roughly classified into three groups as fine wrinkles, linear deep wrinkles and crow's feet. However, academic societies of dermatology or cosmetics have not yet established a definition of wrinkles in Japan. Thus, in advance of setting up an evaluation method, the definition of wrinkles f3r evaluation must be decided. Wrinkles are defined by the task force of the JCIA as follows; furrows that people can recognize visually and that appear on the forehead, the corners of the eyes and the backs of the neck with aging. In addition, furrows are emphasized by exposure to solar light and by dry conditions. Visual evaluation is the most sensitive method and can be applied to most types of wrinkles. However, visual evaluation is hard to express digitally as results. Besides, in the case of image analysis, comparisons of data obtained from distinct examinations can not be done, because data from image analysis are relative values. Thus, to enhance the reliability of the evaluations, the adoption of an objective scale was required. The principle of the evaluation method is to analyze images taken from silicone replicas of wrinkle areas using several parameters, such as the proportion of the wrinkle $area({\%})$, the mean depth of the wrinkles (mm), the mean depth of the deepest wrinkle (m) and the deepest point on the deepest wrinkle. Lights are shown on the skin replica from an orthogonal direction of the main orientation of the wrinkle, and the resulting shadow images are quantified by the image analysis method. To increase the precision of the data or to allow comparisons of independent examinations, a scale with furrows of several depths, 200, 400, 600, 800, and $1000{\mu}m$, is adapted in the evaluation system. I will explain the guidelines established by the JCIA in the presentation.

Meat Quality Changes in Aged Pork Loin using Jeju Volcanic Scoria Earthenware

  • DongGyun Kim;SangHoon Lee;GwangHeun Kim;KyoungBo Ko;YounChul Ryu
    • 한국축산식품학회지
    • /
    • 제43권5호
    • /
    • pp.901-913
    • /
    • 2023
  • This study aimed to investigate changes in the quality of meat aged using Jeju scoria earthenware. Water-holding properties, pH, color, tenderization, fatty acid composition, and free amino acid characteristics of aged pork loin were evaluated to determine the effects of wet and dry (normal and Jeju Scoria) aging methods and aging time (0, 10, 20, 30, and 40 days) on meat quality. The aging methods altered pH and CIE L* after 10 days of aging. However, the aging method did not alter the pH and CIE L* of the aged pork loin after 10 days of aging. The shear force was significantly lower in the Scoria aging method than in the wet aging method after 10 and 20 days of aging. Both the normal and Scoria aging methods increased aging loss compared to the wet aging method, which could be attributed to longer air exposure times of the two non-packaged aging methods than in the packaged aging method. The scoria aging method had significantly higher contents and ratios of saturated (SFA) to mono-unsaturated fatty acids but lower ratios of poly-unsaturated fatty acids to SFA than the wet aging method. The content of most free amino acids significantly increased with aging time, especially those related to the sweet, and umami categories. In summary, this study suggests that the Scoria aging method provides positive aspects of eating quality, such as improvement of meat tenderness and taste, including umami, with minimum changes in the overall meat quality.

대학생을 위한 온라인 노화와 건강관리 교육의 개발 및 평가 (Development and Evaluation of Online Aging and Health Management Education for Undergraduate Students)

  • 박명화
    • 대한간호학회지
    • /
    • 제37권4호
    • /
    • pp.540-548
    • /
    • 2007
  • Purpose: The purpose of this study was to develop online aging and health management education for undergraduate students and to evaluate its effects analyzing the differences in knowledge and attitude toward aging and the elderly. Method: An Online aging and health management education program was established through analysis, planning, content framing and production, program application, and evaluation stages. The study sample consisted of 98 undergraduate students in one university in D city. The instruments used were FAQ I for knowledge of aging and a 20 item semantic differential scale for attitude toward aging and the elderly Results: The results of this study were as follows. First, undergraduate students' knowledge level was low and attitudes were negative at the baseline. Second, after the class, knowledge scores improved significantly from 14.44 to 20.12. In addition, the attitudes toward elderly and aging changed from negative to a more positive way showing a 23.57 point difference. Conclusion: This study shows that the online aging and health management education program was an effective educational method to improve knowledge and attitude of aging for the young generation such as college students.

가공열처리 및 2단시효처리에 의한 8090알루미늄 합금의 석출거동 (PRECIPITAlON BEHAVIOR OF 8090 ALUMINIUM ALLOY BY HERMOMECANICAL AND DUPLEX AGING TREAMENT)

  • 이학용;김석원;우기도
    • 열처리공학회지
    • /
    • 제7권4호
    • /
    • pp.270-276
    • /
    • 1994
  • The effects of thermomechanical and duplex aging treatment on precipitation behavior were investigated for the 8090 aluminium alloy by tensile test, hardness test, plane-strain fracture toughness test and electron microscope. Both pre-aging stretch and duplex aging with pre-aging stretch were effective to homogenize the distribution of S' phase in this alloys. The latter makes more homogeneous distribution of S' phase than that of the former, but the sizes of S' phase in both specimens are almost same. The size and distribution of 0' phase were not changed by thermomechanical or duplex aging treatment. The strength was increased by thermomechanical treatment, but the elongation was decreased. Duplex aging treatment couldn't change the strength and elongation. Pre-aging stretch and duplex aging with pre-aging stretch have same effect on the strength and elongation. The increase of strength by thermomechanical treatment in 8090 alumunium alloy was caused by homogeneously precipitated S' phase.

  • PDF

간호대학생의 자아탄력성 및 가족탄력성이 성공적 노화 인식에 미치는 영향 (Influence of Ego Resilience and Family Resilience on the Perception of Successful Aging in Nursing Students)

  • 양남영;송민선
    • 가정간호학회지
    • /
    • 제26권3호
    • /
    • pp.278-287
    • /
    • 2019
  • Purpose: This study aims to examine the relationship between ego resilience, family resilience, and the perception of successful aging in nursing students; additionally, specific factors relating to the perception of successful aging were identified. Methods: The participants comprised 154 nursing students. Data were collected through the administration of self-reported questionnaires. Data analysis was then performed utilizing a t-test, an ANOVA, Pearson's correlation coefficients, and a multiple regression analysis. Results: Family resilience differed significantly based on the type of residence (p=.020) (i.e., living with grandparents (p=.048)). Perception of successful aging differed significantly based on grade (p<.001). The perception of successful aging showed a positive correlation relative to mode of communication and organizational pattern. The mode of communication accounted for 4.7% of perception of successful aging. Conclusion: The significance of the study on the importance of mode of communication was confirmed by identifying the effects of the perception of successful aging. Nursing students may actively cope with crises through communication; thus, successfully recognizing aging in order to lead a healthy life. Furthermore, having a high perception of successful aging while treating an increasing number of elderly patients at the clinical practice is believed to have a positive effect on patient care.

Effects of Aging Treatment of doped-MgO Layer on Discharge Characteristics of ac-PDP

  • Park, Kyung-Hyun;Ko, Min-Soo;Yoon, Sang-Hoon;Kim, Yong-Seog
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
    • /
    • pp.216-219
    • /
    • 2007
  • Effects of aging treatment of doped-MgO electron emission layer on luminance efficiency of ac-PDP were investigated in this study. Morphological and luminance efficiency with aging treatment were examined, especially with emphasis on the effects of doping elements. The results indicate that the luminance efficiency of test panels depends on the type of doping elements used for MgO and that may be due to the redeposition of MgO during glow discharge.

  • PDF

숙성조건이 장미꽃 추출물의 페놀화합물(phenolics) 함량과 산화방지 활성에 미치는 영향 (Effects of aging on the phenolics content and antioxidant activities of rose flower (Rosa hybrida L.) extracts)

  • 김소영;고승현;윤현근
    • 한국식품과학회지
    • /
    • 제49권6호
    • /
    • pp.714-716
    • /
    • 2017
  • 장미꽃을 $30^{\circ}C$, 상대습도 60%의 조건에서 24시간 동안 숙성하여 총페놀화합물 함량, 산화방지 활성, 카테킨 함량을 최대로 증가시키는 조건을 수립하였다. 장미꽃을 차로 이용하기 전에 숙성공정을 통하여 생리활성 물질인 카테킨을 비롯한 페놀화합물의 추출 효율을 증가시킬 수 있고 이에 따라 장미꽃 차의 산화방지효과를 증대 시킬 수 있다.