• Title/Summary/Keyword: aging process

Search Result 1,254, Processing Time 0.035 seconds

Wire electrical discharge machining of titanium alloy according to the heat treatment conditions (열처리 조건에 따른 티타늄합금의 와이어 방전가공)

  • 김종업;왕덕현;김원일
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2001.04a
    • /
    • pp.930-933
    • /
    • 2001
  • Titanium Alloys used in this experiment has an good corrosion resistance and specific strength, and is the new material developed for medical supplies living goods. In this study the rolled titanium alloy is done by annealing, solution heat-treatment and aging and then is worked by wire EDM. With changing the process conditions, the process properties of surface hardness, surface roughness, shape of process surface and the analysis of ingredients are measured through experiment repeating main cut and finish cut. It is confirmed to gain good measure values as increasing the number of processing of wire EDM. In this experiment the phenomena of processing is studied and the appropriate process condition is proposed.

  • PDF

A Study on the Public Space Planning of Congregate Housing of the Elderly (고령자(高玲者)를 위한 집합주거시설(集合住居施設)의 공용공간(共用空間) 계획(計劃)에 관한 연구(硏究))

  • Park, Nam-Hee;Lee, Sang-Ho
    • Proceedings of the Korean Institute of Interior Design Conference
    • /
    • 2007.05a
    • /
    • pp.105-109
    • /
    • 2007
  • Aging society appears immediate social problem in Korea. Housing for aging is required independent and comfortable housing life to live considering about feature of elderly. It is necessary field to prepare. Aged person who suffers the aging process several stages gets changing weak, so living environment is important aging person aspect of social, psychological and physical point. Finally, aged person living together requires facilities for the naturally communicating and active things. Community of aged person required organization of space for keeping independence and connection with each other. According to space of community, housing for aging should have a different access route. In conclusion, congregate housing of the elderly should be planed organization of space to be solved anxiety and tension and to be aware of joining the community.

  • PDF

Development of a Lesson Proposal about the Aging for Middle School Students (중학생을 대상으로 하는 노인교육 수업안의 개발)

  • 김향은
    • Journal of Korean Home Economics Education Association
    • /
    • v.15 no.1
    • /
    • pp.33-42
    • /
    • 2003
  • The Purpose of this study was to develop a lesson proposal about the aging for 7th glade middle school students in the class of home economics. According to this Purpose a lesson Proposal about the aging which contains 1) the nature of generation gap and generational conflicts and problem solving strategies. 2) knowledges about physical. emotional. and social changes of older adults and the process of aging. 3) informations of various order adult-related Professions was devised This proposal will be helpful for younger people to understand older adult much more and to Prepare the adolescents' future life as an older people. It is expected to have effects on decrease the generation gap and conflicts between older and younger people based upon mutual understanding. And it is anticipated that this Proposal will be valuable for many adolescents to have provision about future senior citizen's society and various older adults-related professions .

  • PDF

Evaluation of the Organic Linings at Gas Desulfurization System (탈황 설비용 유기 라이너의 평가)

  • Song, Yo-Seung;Kwan, Hyun-Ok;Jho, Nam-In
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.29 no.11
    • /
    • pp.1178-1182
    • /
    • 2012
  • The organic linings at flue gas desulfurization systems (FGD system) in power plant have the excellent chemical properties but, lose the anticorrosive properties according to the aging with environment conditions. The properties of the organic linings depend on the manufacturing company. Therefore, the basic properties of organic linings for the preestimate of life time should be examined by conducting the aging and the bond strength test according to temperature. The pre-aging samples were compared with the post-aging samples. The temperature conditions of the aging process were 70, 150 and $200^{\circ}C$. The bond strength was calculated and the cross sections of fracture surface were examined by optical microscope and SEM. The $T_g$ was examined by DSC, DTA and TGA.

Zirconia galvani sensor for the measurement of oxygen activity (용존산소활량 측정용 지르코니아 갈바니 센서)

  • Oh, Young-Jei
    • Journal of Sensor Science and Technology
    • /
    • v.18 no.6
    • /
    • pp.441-448
    • /
    • 2009
  • Magnesia partially stabilized zirconia(Mg-PSZ) solid electrolytes for an improvement of thermal shock resistance, which is suitable for the measurement of oxygen activity in a molten steel, were prepared by post-thermal aging treatment. The steelmaking oxygen sensor elements were formed by an injection molding method, sintered at $1650^{\circ}C$, and then thermal aged ranged from 1250 to $1400^{\circ}C$. Sintered density and porosity were decreased as increasing the magnesia content in a zirconia-magnesia solid solution. Fractions of cubic phase to the synthesized Mg-PSZ solid electrolytes were ranged from 13.13 to 79.54.% after post-thermal aging treatment. Very dense microstructure without voids in the grains was obtained by the post-thermal aging process. Fine tetragonal phase crystallites precipitated on the cubic surface during post-thermal aging up to $1300^{\circ}C$ improve a thermal shock resistance and reappearance of electro motive force(EMF) curve.

Preparation of Saccharified kochujang with Retrograded Rice Cakes (노화된 떡을 이용한 당화고추장의 제조에 관한 연구)

  • 차은정;김경자
    • Korean journal of food and cookery science
    • /
    • v.14 no.3
    • /
    • pp.219-224
    • /
    • 1998
  • Kochujang was prepared by using retrograded rice cakes (Song Pyun, Sym rice cake, Ssuk rice cake, Pat rice cake) as a source starch and the physiochemical and sensory characteristics were compared with traditional kochujang during aging for 60 days. Moisture content of all kochujang groups increased slowly but crude fat content decreased according to aging process. Changes of pH values of all kochujang reduced gradually during aging and the pH of saccharified kochujang was lowered than that of traditional one. Total reducing sugar contents in saccharified kochujang reached the maximum value at 50th day, and decreased thereafter. In contrast, the reducing sugar content in traditional kochujang was the highest at 30-day-aging. After 60 days of aging, the total contents of organic acids were 28.57 mg for P$\_$1/, 27.9 mg for P$\_$4/, 27.05 mg for P$\_$3/ 24.60 mg for P$\_$2/, and 22.30 mg for P$\_$0/. By sensory evaluation, saccharified kochujang prepared with Siru rice cake showed the highest sensory score in its appearance, flavor, texture, color, and taste.

  • PDF

Aging Characteristic of Shear Strength in Micro Solder Bump (마이크로 솔더 범프의 전단강도와 시효 특성)

  • 김경섭;유정희;선용빈
    • Journal of Welding and Joining
    • /
    • v.20 no.5
    • /
    • pp.72-77
    • /
    • 2002
  • Flip-chip interconnection that uses solder bump is an essential technology to improve the performance of microelectronics which require higher working speed, higher density, and smaller size. In this paper, the shear strength of Cr/Cr-Cu/Cu UBM structure of the high-melting solder b01p and that of low-melting solder bump after aging is evaluated. Observe intermetallic compound and bump joint condition at the interface between solder and UBM by SEM and TEM. And analyze the shear load concentrated to bump applying finite element analysis. As a result of experiment, the maximum shear strength of Sn-97wt%Pb which was treated 900 hrs aging has been decreased as 25% and Sn-37wt%Pb sample has been decreased as 20%. By the aging process, the growth of $Cu_6Sn_5$ and $Cu_3Sn$ is ascertained. And the tendency of crack path movement that is interior of a solder to intermetallic compound interface is found.

Aging Characteristics of Al P/M Composites with Variation of Ceramic Contents

  • Min, Kyung-Ho;Chang, Si-Young;Kim, Deok-Soo;Kim, Ji-Soon;Kim, Young-Do
    • Proceedings of the Korean Powder Metallurgy Institute Conference
    • /
    • 2006.09b
    • /
    • pp.1065-1066
    • /
    • 2006
  • The aging behavior of sintered Al composites with various ceramic contents was investigated. 2xxx series blended powder was used as the starting powder. Ceramic contents were 0wt.% and 5wt.%. The blended powders were compacted at 250MPa. The sintering process was performed at $620^{\circ}C$ for 60min in a $N_2$ atmosphere. Each part was solution-treated at $518^{\circ}C$ for 60min and aged at $180^{\circ}C$. The Rockwell hardness at the peak aging time increased with ceramic contents. However, the peak aging time at maximum hardness was reduced with increased ceramic contents.

  • PDF

LCD Cell Aging Tester

  • Son, Hyuk;Baek, Sung-Sik;Oh, Hyeong-Geun;Choi, Byoung-Deog
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2009.10a
    • /
    • pp.1383-1385
    • /
    • 2009
  • This paper suggests that testing method and equipment structure to detect potential failures of LCD cells. LCD Cell Aging Tester is the unique process to detect failures related with ASG circuits. This system consists of four components that is Aging chamber, work table, probe contact unit, and pattern generator. The key factor of the concept is temperature aging and HVS driving. Complicated combination of test parameters including voltage, temperature and frequency provided practical burn-in conditions eligible for prediction of mass production.

  • PDF

Dynamic Rheological Properties of Hydroxypropylated Rice Starches during the Aging Process (Aging 과정 중 하드록시프로필화 쌀전분의 동적 레올로지 특성)

  • Choi, Hye-Mi;Yoo, Byoung-Seung
    • Korean Journal of Food Science and Technology
    • /
    • v.39 no.5
    • /
    • pp.584-587
    • /
    • 2007
  • The effect of molar substitution (MS, 0.030-0.118) on the dynamic rheological properties of hydroxypropylated rice starch pastes (5%, w/w) was investigated by small-deformation oscillatory measurements during aging. The magnitudes of storage (G#) and loss (G") moduli measured at $4^{\circ}C$ before aging increased with an increase in MS in the range of 0.030-0.118, while those of tan ${\delta}$ (the ratio of G"/G#) decreased. The G# values of hydroxypropylated rice starches, as a function of aging time (10 hr) at $4^{\circ}C$, increased rapidly at the initial stage, and then reached a plateau region at shorter aging times. However, for the native starch, the plateau values were not observed for G# after a long aging time. Increasing the MS resulted in a decrease in plateau values. The rate constant (K) for structure development during aging was described by first-order kinetics. The K values of hydroxypropylated rice starches at 0.086 and 0.118 MS were much lower than the K value at 0.030 MS.