• Title/Summary/Keyword: wear behavior

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Control of Crowning Using Residual Stress induced by the Difference of Tehermal Expansion Between Ceramic and Carbon Steel in Ceramic Cam Follower (열팽창계수차에 기인된 잔류응력을 이용한 세라믹 캠 팔로우어의 크라우닝 제어)

  • Choe, Yeong-Min;Lee, Jae-Do;No, Gwang-Su
    • Korean Journal of Materials Research
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    • v.10 no.10
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    • pp.703-708
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    • 2000
  • As the engine design changes to get high efficiency and performance of commercial diesel engine, surface w wear of the earn follower becomes an important issue as applied load increasing at the contact face between cam follower and cam. We developed the ceramic cam follower made of sili$\infty$n nitride ceramic which was more wear resistant than the cast iron or sintered metal cam follower. Ceramic cam follower was made by direct brazing of thin ceramic disk to steel body using an active brazing alloy without the interlayer. In-situ crowning(R), resulted from the difference of thermal expansion coefficient between ceramic and carbon steel after direct brazing without any stress-relieving inter]ayer, could be controlled. When a earbon steel was heated above $A_{c1}$ point and then c$\infty$led, the expansion curve represented a hysteresis. Appropriate crowning was achieved below the $A_{c1}$ point(about $723^{\circ}C$) and crowning increased with brazing temperature exponentially above the $A_{c1}$ point. Optimum brazing temperature range was from 700 to $720^{\circ}C$. We developed successfully the ceramic cam follower having appropriate crowning and being inexpensive. Also we could successfully control the crowning of ceramic earn follower by hysteresis behavior of thermal expansion of earbon steel during direct brazing process.

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Carbon diffusion behavior and mechanical properties of carbon-doped TiZrN coatings by laser carburization (레이저 침탄된 TiZrN 코팅에서 탄소확산거동과 기계적 특성)

  • Yoo, Hyunjo;Kim, Taewoo;Kim, Seonghoon;Jo, Ilguk;Lee, Heesoo
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.31 no.1
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    • pp.32-36
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    • 2021
  • This study was investigated in carbon diffusion behavior of laser-carburized TiZrN coating layer and the changes of mechanical properties. The carbon paste was deposited on TiZrN coatings, and the laser was irradiated to carburize into the coatings. The XRD peak corresponding to the (111) plane shifted to a lower angle after the carburization, showing the lattice expansion by doped carbon. The decreased grain size implied the compression by the grain boundary diffusion of carbon. The XPS spectra for the bonding states of carbon was analyzed that carbon was substitute to nitrogen atoms in TiZrN, as carbide, through the thermal energy of laser. In addition, the combination of sp2 and sp3 hybridized bonds represented the formation of an amorphous carbon. The cross-sectional TEM image and the inverse FFT of the TiZrN coating after carburizing were observed as the wavy shape, confirming the amorphous phase located in grain boundaries. After the carburization, the hardness increased from 34.57 GPa to 38.24 GPa, and the friction coefficient decreased by 83 %. In particular, the ratio of hardness and elastic modulus (H/E) which is used as an index of the elastic recovery, increased from 0.11 to 0.15 and the wear rate improved by 65 %.

A Study on the Clothing Appropriateness for the Role Behavior af Achieving a Successful Learning and Teaching Efficiency (성공적인 학습의 역할수행을 위한 의복의 적합성에 관한 연구 -교사/교수의 의복행동을 중심으로-)

  • 한명숙
    • Journal of the Korean Home Economics Association
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    • v.25 no.2
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    • pp.39-54
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    • 1987
  • One's Clothing Satisfaction, has a great influence on his role behavior in a society. Especially, as for the teacher's and the professors whose role is teaching, it can not be too emphaszed. Above all, high school girls and college women are the most likely to be influenced by their teachers' clothing behavior, to whom they pay their respect in every way. From this point of view, this study was aimed at explaining, the correlation between the teachers/professors' clothing behaviors and the learning efficiency. On clothing behaviors assessed 30 items related with the learning efficiency, selected from the instruments of preceding studies, and modified by the factors dealing with modesty, color, and design. The questionnaires were composed of two major categories: those for students and for teachers/progessors. The subjects of this study were included students and teachers/professors of high school and universities in Seoul. The data were analyzed statically by mean, standard Deviation, and F-test. The results of this study were summerized as follows; 1. The clothing behaviors of the teachers/professors influenced on the learning efficiency. Namely teachers' clothing satisfaction is in direct proportion to them teaching efficiency and students' learning efficiency. 2. Among the clothing behavior variables, modesty had a great influence on the learning efficiency, especially as for that of teachers more than professors. 3. The influence of the teachers'/professors' clothing behaviors on the learning efficiency showed no significance between high school girls and college women, but some significance between the grades of collegians. 4. As for the teachers'/professors' clothing behavior, male teachers/professors gave priority to design and female teachers/professors to modesty, color showed no significance between them irrespective of age. 5. As for the clothing behavior variabels, both the teachers/professors and the students showed some significance. In class the teachers/professors highly responded to their own clothing behaviors than the students. 6. According to priority the most favorable clothing colors for male teachers/professors are navy blue, gray, indigo blue, and black, and the most disgusting ones red, mud yellow, violet, pink, and green. The most favorable clothing colors for female teachers/professors are beign, white, pale yellow, and black, and the most disgusting ones red, mud yellow, and yellow and yellow according to priority. It is that teachers/professors should wear modestly and in color harmony to invite the desirable students' will to study. Teachers'/professors' colorful appearance and heavy toilet bring about a drop in the students' will to study.

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Effect of Atmospheric Music and Advertising Photo on Consumers' Emotional State and Approach Behavior in Fashion Store (패션점포 내 배경음악과 광고사진이 소비자의 정서 및 접근행동에 미치는 영향)

  • Ki, Hyun-Myoung;Lee, Yu-Ri
    • Journal of Global Scholars of Marketing Science
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    • v.16 no.3
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    • pp.39-60
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    • 2006
  • The purpose of this study is to investigate the effect of two different characteristics of music(tempo) and advertising photograph(type) in a fashion store on consumers' emotional responses and approach behavior and to suggest competitive in-store atmospheric strategies. To test the conceptual model, this study used a video simulation method. Researchers selected a fashion casual wear retail store for young people and videotaped to provide realistic store settings. Two different levels of background music(fast, slow) and advertising photograph(sexy, cheerful) were inserted into the video clip generating four stimuli. Including a stimulus for the control group, 5 video clips were created. A total of 289 subjects answered the questionnaire after viewing a two-minute video clips. The results are as follows: First, advertising photograph in a store had a significant effect on consumers' in-store emotional state, whereas musical tempo did not. Second, the effect of in-store consumers' emotional state on behavioral reponses were investigated. Results showed that consumers' positive emotional state lead to consumers' approach behavior. The results of this study indicated that background music and advertising photograph in a fashion store affected consumers' in-store emotional state, and ultimately these affected consumers' positive approach behavior. Thus retailer should try to create a pleasant store environment using effective store atmospheric factors like background music and advertising photograph.

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Strength Properties and Elastic Waves Characteristics of Silicon Carbide with Damage-Healing Ability (손상치유 능력을 가지는 탄화규소의 강도 특성과 탄성파 특성)

  • KIM MI-KYUNG;AHN BYUNG-GUN;KIM JIN-WOOK;PARK IN-DUCK;AHN SEOK-HWAN;NAM KI-Woo
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.05a
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    • pp.337-341
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    • 2004
  • Engineering ceramics have superior heat resistance, corrosion resistance, and wear resistance. Consequently, these art significant candidates for hot-section structural components of heat engine and the inner containment of nuclear fusion reactor. Besides, some of them have the ability to heal cracks and great benefit can be anticipated with great benefit the structural engineering field. Especially, law fracture toughness of ceramics supplement with self-healing ability. In the present study, we have been noticed some practically important points for the healing behavior of silicon nitride, alumina, mullite with SiC particle and whisker. The presence of silicon carbide (SiC) in ceramic compound is very important for crack-healing behavior. However, self-healing of SiC has not been investigated well in detail yet. In this study, commercial SiC was selected as sample, which can be anticipated in the excellent crack healing ability. The specimens were produced three-point bending specimen with a critical semi-circular crack of which size that is about $50-700{\mu}m$. Three-point bending test and static fatigue test were performed cracked and healed SiC specimens. A monotonic bending load was applied to cracked specimens by three-point loading at different temperature. The purpose of this paper is to report Strength Properties and Elastic Waves Characteristics of Silicon Carbide with Crack Healing Ability.

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Babies' Wear Shopping Behavior of Housewives by Their Fashion Lifestyle (주부의 의생활양식에 따른 유아복 점포행동)

  • 황춘섭
    • Journal of the Korean Society of Costume
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    • v.48
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    • pp.183-196
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    • 1999
  • The purpose of the Present research is to investigate the effect of fashion lifestyle on babies' clothing shopping attitude of housewives. In this study shopping attitude includes criteria for shop selection prefered types of shop and prefered shop atmosphere. Subjects are 447 housewives residing in Seoul Bundang Illsan and Pungchon and having child under 4 years old Data was analyzed by factor analysis cluster analysis analysis of variance and chi-square. The results of the study are as follows: 1. Housewives can be classified into four groups according to their fashion lifestyle the group of planned buying conservative/practical group the group of self-actualization/individuality and the high involved and care for shopping group. 2. Fashion lifestyle is different according to their age. The high involved and care for shopping group have the lager proportion in twenties than thirties. The conservative/practical group have a larger proportion in thirties. 3. The factors of shop selection which serve as criteria for shop the quality of service encironment anround shop quality of goods convenience to care about babies fashionable goods location of the shop and price of goods. The group of self actualization/personality prefers shops carrying fashionable and unique style of babies clothing and showing prestige. The conservative/practical group prefers shops carrying good quality clothing and having variety in size and design. The high involved and careful shopping group prefers shops having wide space as well as carrying fashionable goods. 4. Among the types of babies clothing shops. department stroe is the most preferred Low-price brand shop is followed by traditional open market. The conservative/practical group and the group of planned shopping use department strores national bran shops street shops and import shops more often than other groups. 5. The result of the study indicates there are considerable differences in housewives attitudes of babies clothing shopping acording to their own fashion lifestyle. Therefore the retailer of babies clothing should decide their marketing policy on the basis of the understanding and analysis of costomer's fashion lifestyle. And they have to reflect their costomer's shopping attitudes on their marketing policy to improve the satisfaction of both consumer and retailer as well.

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Friction Behavior of Oil-enriched Nanoporous Anodic Aluminum Oxide Film (오일 함침된 나노 기공 산화알루미늄 필름의 마찰 거동)

  • Kim, Hyo-Sang;Kim, Dae-Hyun;Hahn, Jun-Hee;Ahn, Hyo-Sok
    • Tribology and Lubricants
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    • v.27 no.4
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    • pp.193-197
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    • 2011
  • Friction behavior of nanoporous anodic aluminum oxide(AAO) film was investigated. A 60 ${\mu}m$ thick AAO film having nanopores of 45 nm diameter with 105 nm interpore-diatance was fabricated by mild anodization process. The AAO film was then saturated with paraffinic oil. Reciprocating ball-on-flat sliding friction tests using 1 mm diameter steel ball as the counterpart were carried out with normal load ranging from 0.1 N to 1 N in an ambient environment. The morphology of worn surfaces were analyzed using scanning electron microscopy. The friction coefficient significantly increased with the increase of load. The boundary lubrication layer of paraffinic oil contributed to the lower friction at relatively low load (0.1 N), but it is less effective at high load (1 N). Plastic deformed layer patches were formed on the worn surface of oil-enriched AAO at relatively low load (0.1 N) without evidence of tribochemical reaction. On the other hand, thick tribolayers were formed on the worn surface of both oil-enriched and as-prepared AAO at relatively high load (1 N) due to tribochemical reaction and material transfer.

User's Voluntary Heating Behavior for the Programming of the Efficient Heating Mode of Smart Base Layer Clothing (스마트 베이스 레이어 의복의 효과적인 발열모드 설정을 위한 사용자의 자율적 가열행동 연구)

  • Lee, Heeran;Hong, Kyunghi;Lee, Yejin;Kim, Soyoung
    • Journal of the Korean Society of Clothing and Textiles
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    • v.41 no.5
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    • pp.872-882
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    • 2017
  • There are no specific guidelines on how to control the heat input for the heat generating smart base layer. This study investigated the mode of actuating heat pad attached to the base layer by performing a human wear test in a cold environment. Subjects participating in the test wore T-shirts, jumper and pants on the base layer with heating pads. Skin temperature, total time of heating and the number of switching for the heating mode were observed as the subject controlled the heating mode voluntarily. The comfortable range of skin temperature on the abdomen was larger than on the lower back. The subject felt hot and turned off the switch when the mean skin temperature of the abdomen was $48.8^{\circ}C$ and the lower back was $40.1^{\circ}C$. The total heating time and the number of actuating switching were larger for women than men. The voluntary action of heating for men with high cold sensitivity was significantly different from men with low cold sensitivity. Therefore, it is necessary (depending on gender and cold sensitivity) to set the heating mode differently for the automatic heat control of a future smart base layer.

Consumer Age Group Differences in Knitwear Consumption Behavior (소비자 연령대에 따른 니트웨어 착용 및 소비행동의 차이)

  • Lee, Young-Min;Kim, Yeon-Hee;Kim, Mi-Jin;Lee, Yun-Kyung;Youn, Song-Yi;Lee, Kyu-Hye
    • The Research Journal of the Costume Culture
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    • v.15 no.2 s.67
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    • pp.284-298
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    • 2007
  • Due to consumers' preferences for seeking a quality life and having more leisure time, comfortableness became a major criteria for selecting clothes for all age groups. This is why consumers' interests in knitwear increased recently. The purpose of this study is to analyze the knitwear consumption patterns such as style preferences, and consumer satisfaction with knitwear. Particularly, differences in age groups of consumers were analyzed. Data from 463 men and women participated in the study. Results indicated that consumers wear knits once or twice a week in average. After two to three years of consumption, they discard the knitwear. Among various apparel product categories, Consumers selected Cardigan to be the preferable knitwear product category. They preferred 100% cotton and achromatic or gray/brown color with solid fabrics. In general, consumers were most satisfied with colors and least satisfied with laundering of knitwear. Older consumers preferred knitwear to woven products, preferred pull-over style and valued feelings of softness and comfortableness when wearing knitwear. There were more differences in dissatisfaction factors than satisfaction factors according to the consumer age groups.

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Analysis of Visiting Trade Area by College Students for Clothing Purchase using GIS - Focused on Buying Time - (GIS를 이용한 대학생 의류 구매의 상권 방문 분석 - 구매 시기를 중심으로 -)

  • Jung, Hyun-Ju;Choi, Eun-Mi
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.2
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    • pp.183-193
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    • 2006
  • The purpose of this study is to examine differences in college students' spatial behavior and time for purchasing (weekdays or weekends) according to trading areas they use to purchase casual wears and formal wears. An empirical research developed a questionnaire as a measuring tool to conduct a main survey. McNemar test were carried out by using the SPSS to test statistical differences in spatial buying behaviors between weekdays and weekends. ArcGIS 9.1 and ArcView GIS 3.2a program were applied to visualize the results adopting a spider display technique to understand students clothing buying behaviors. This study obtained the result of that there were differences in college students' selecting a trading area according to the time for purchasing(weekdays or weekends) clothing wears. This study implies that understanding individual clothing spatial behaviors help to set up the strategy of trade area as well as store for marketers related to the fashion industry.

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