• Title/Summary/Keyword: physical modification

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Nickel Doping on Cobalt Oxide Thin Film Using by Sputtering Process-a Route for Surface Modification for p-type Metal Oxide Gas Sensors

  • Kang, Jun-gu;Park, Joon-Shik;An, Byeong-Seon;Yang, Cheol-Woong;Lee, Hoo-Jeong
    • Journal of the Korean Physical Society
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    • v.73 no.12
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    • pp.1867-1872
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    • 2018
  • This study proposes a route for surface modification for p-type cobalt oxide-based gas sensors. We deposit a thin layer of Ni on the Co oxide film by sputtering process and annealed at $350^{\circ}C$ for 15 min in air, which changes a typical sputtered film surface into one interlaced with a high density of hemispherical nanoparticles. Our in-depth materials characterization using transmission electron microscopy discloses that the microstructure evolution is the result of an extensive inter-diffusion of Co and Ni, and that the nanoparticles are nickel oxide dissolving some Co. Sensor performance measurement unfolds that the surface modification results in a significant sensitivity enhancement, nearly 200% increase for toluene (at $250^{\circ}C$) and CO (at $200^{\circ}C$) gases in comparison with the undoped samples.

A Study on the Hydrophobicity Modification and Physical Properties of Tencel Regenerated Fibers for Polypropylene Resin Composites (폴리프로필렌 수지 복합을 위한 텐셀 재생섬유의 소수화 표면개질 특성 연구)

  • Yoon, Songhyun;Kim, Mikyung;Lee, Eunsoo
    • Textile Coloration and Finishing
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    • v.33 no.4
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    • pp.258-268
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    • 2021
  • This study conducted on the introduction of recycled cellulose fibers, which are widely used in the textile industry as eco-friendly biomass materials, into polypropylene resins, which are mainly used for interior and exterior materials such as door trims and console parts of automobiles. In general, cellulose fibers can affect mechanical properties and have a lightening effect when used as a reinforcing agent. However, since cellulose fibers have hydrophilic properties and have relatively low compatibility with industrial polymer resins, they are used in combination through fiber hydrophobic surface treatment. Therefore, through this study, the reforming reaction conditions optimized in terms of hydrophobicity and workability for cellulose fibers are studied. Furthermore, polypropylene containing surface-modified cellulose fibers was prepared to compare physical properties by fiber content and study optimized content.

Short-term Effects of a Lifestyle Intervention Program on Eating Behaviors, Physical Activity and Cardiovascular Risks in Korean Adults (생활습관개선 프로그램이 성인의 식이행동과 신체활동 및 심혈관위험요인에 미치는 효과: 중재 3개월 결과를 중심으로)

  • Park, Jiyeon;Kim, Hyekyeong
    • Korean Journal of Health Education and Promotion
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    • v.31 no.4
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    • pp.37-49
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    • 2014
  • Objectives: The aim of this study was to evaluate the effects of a lifestyle modification program for Korean adults with cardiovascular disease risk factors on their health behaviors and health status. Methods: A total of 448 adults with abdominal obesity and additional cardiovascular disease risk factors(high blood pressure, low HDL-cholesterol, high triglyceride or high blood glucose) were randomly assigned to either an intensive intervention group (IIG, n=216) or a minimal intervention group(MIG, n=232). Participants in the IIG received lifestyle modification program which consisted of health counseling with nutrition assessment, health booklet and health diary, while those in MIG received minimal information. Results: The participants in the IIG significantly improved dietary habits(p<.05), retrained eating(p<.001), external eating(p<.01) behaviors, leisure time physical activity(p<.05), dietary self-efficacy(p<.01), exercise self-efficacy(p<.01) and MetS score(p<.001) after 3 months. In addition, the participants in the IIG showed more improvement in dietary habits(p<.05) compared with those in the MIG. Conclusion: The lifestyle modification program was effective in improving some health behaviors, behavioral determinants and cardiovascular risk factors for a short term.

Properties of Coated Paper and Printabilities by Surface Modification of Pigments for Papermaking

  • Cho, Jun-Hyung;Lee, Yong-Kyu;Lee, Yong-Won;Min, Dong-Jin;Kim, Yong-Sik
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2006.06b
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    • pp.499-504
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    • 2006
  • To improve the quality of coating paper, many areas, such as the manufacturing process of inorganic pigment for the coating, the property change of coating color, the surface design of coating pigment and the productivity of coated paper, were studied. In this study the physical properties and printability of coated paper were compared with the coating pigment to modify the surface of large particle and the coating pigment to mix together the large and small particles. After the coating color was mixed under the same conditions in order that the coating color has the same printability, the printability change caused by the surface modification of coating color was investigated. With the surface SEM of coated paper, the efficiency of the surface modification of coating pigment was investigated. The physical property and printability of coated paper, in addition to the physical properties of coating color, were compared and evaluated. Also, the efficiency of printability was evaluated, changing the mixing condition.

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Uniform Modification and Fashion Accessory Wearing According to Attitudes toward Uniform of High School Students (고등학생의 교복태도에 따른 교복변형과 패션 액세서리 착용)

  • Jeon, Chae-Ryeong;Kim, Yong-Sook
    • Journal of the Korean Society of Costume
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    • v.57 no.2 s.111
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    • pp.132-142
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    • 2007
  • School uniforms are mass produced by large companies and prominent fashion designers. However many high school students modify their uniform or use fashion accessaries to pursue their individualities and their unique style. The objectives of this research were to identify uniform modification and fashion accessory wearing according to the attitudes toward uniform of high school students. The results were as follows; 1. Factors of the attitudes toward school uniform were style and brand, fashion, role intimation, individuality, and neatness. High school students were classified as the uniform indifference group, the pro-uniform group, and the centrist-uniform group according to their attitudes toward uniform. 2. Many students in academic or boys' high schools were classified into the centrist-uniform stoup, and many in art & physical educational or coeducational high schools were classified into the pro-uniform group. The pro-uniform group modified uniform more and stated that the regulation on the fashion accessory wearing was very strict. The uniform indifference group modified uniform less than other groups and complained less about regulation of fashion accessary wearing. 3. Students in art & physical educational high schools showed more positive tendency toward uniform attitudes, uniform modification, and fashion accessary regulation compliances.

Health education-communication approaches in health examinations for risk behavior modification

  • Yoo, Seung-Hyun
    • Korean Journal of Health Education and Promotion
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    • v.3 no.1
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    • pp.83-98
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    • 2001
  • Although periodic health examination has been one of the most common practices of preventive medicine, its effect on modification of risk behavior has been seldom assessed. Thus, this study attempted to demonstrate the influence of a health examination on modification of cardiovascular disease related health risk behaviors such as smoking, physical inactivity, and obesity. Data of 893 adults were derived from two types of a popular and highly acclaimed health examination program. With a conceptual model constructed using Persuasive Communication variables, McNemar tests examined Source-Outcome association, hypothesizing that different health examination programs would yield different levels of behavior change in smoking, physical inactivity, and obesity. No significant behavior change was found in any of the two health examination programs. Instead, previously established Receiver-Outcome relationship was reconfirmed by logistic regression modeling where gender was the most prominent predictor of all three behaviors. Men were more likely to be current smokers (OR=0.029), exercisers (OR=2.629), and obese (OR=0.237). The importance of followups after health examination is highly stressed as well as that of gender-specific health education strategies. This study recommends applying the social-ecological approaches in health examination, which emphasizes the support and collaboration at individual, family, organizations, community, and policy level to improve health. Long term and qualitative evaluation of health examination may provide more foundation for increasing the effectiveness of health education and communication in health examinations.

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Identifying psychological predictors of adherence to a community-based lifestyle modification program for weight loss among Chinese overweight and obese adults

  • Leung, Alice Wai Yi;Chan, Ruth Suk Mei;Sea, Mandy Man Mei;Woo, Jean
    • Nutrition Research and Practice
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    • v.13 no.5
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    • pp.415-424
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    • 2019
  • BACKGROUND/OBJECTIVES: Existing evidence on lifestyle modification programs for weight loss is limited by the high attrition rate of such programs. Identifying predictors of adherence to a lifestyle modification program could result in program improvement. However, little is known about behavior-specific adherence and its psychological predictors. This study aimed to examine the psychological predictors of adherence after one-month participation in a community-based lifestyle modification program among Chinese overweight and obese adults in Hong Kong. SUBJECTS/METHODS: A total of 205 Chinese overweight and obese adults aged $38.9{\pm}10.5years$ completed the study. Data were collected at baseline and after one month using self-reported questionnaires, which assessed knowledge (self-developed scale), motivation (Treatment Self-Regulation Questionnaire), stage of change (Stage of Exercise Scale) and self-efficacy (Self-Rated Abilities for Health Practices Scale). At one month, a 4-day dietary recall and the International Physical Activity Questionnaire-Short Form were used to assess dietary and physical activity (PA) adherence. Food and PA diaries were examined to indicate self-monitoring. Program attendance was tracked between baseline and one-month follow-up. RESULTS: After one month, participants reported high dietary adherence, attendance, and adherence to self-monitoring but low PA adherence. Multiple regression analyses suggested that diet self-efficacy (baseline) and nutrition knowledge (one-month change) were independent predictors of dietary adherence score at one month, whereas autonomous PA motivation (baseline) and PA self-efficacy (both baseline and one-month change) were independent predictors of PA adherence score at one month. No significant psychological predictor was identified for attendance or self-monitoring. CONCLUSIONS: The results suggest that the effect of psychological factors on adherence differs between diet and PA adherence outcomes. To promote adherence, practitioners should assess self-efficacy, knowledge, and motivation at the beginning of a weight-loss program and explore behavior-specific strategies to improve knowledge and self-efficacy. The results of this study have direct implications for program improvements.

Properties of Modified Rice Starch by Physical Modification (물리적 변성에 의한 쌀변성전분의 이화학적 성질)

  • Kum, Jun-Seok;Lee, Hyun-Yu;Shin, Myoung-Gon;Yoo, Mi-Ra;Kim, Kil-Hwan
    • Korean Journal of Food Science and Technology
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    • v.26 no.4
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    • pp.428-435
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    • 1994
  • Properties of modified rice starches prepared in drum drying and extrusion were evaluated to use for effective utilization. Blue value was the lowest (p<0.05) for waxy rice starch and L value was decreased after modification of starches. Water solubility index was the highest for modified starches prepared in extrusion, while water absorption index was the highest for modified starches prepared in drum drying. Cold-Water-Solubility was the highest (p<0.05) for modified rice starch prepared in drum drying (RD). Consistency index of RD was drastically increased as shear rate increased and yield stress was the highest for RD. Results of Gel Permeation Chromatography showed that starch components were broken down into lower molecular weight materials and amylose are degraded by modification. Changes in the X-ray diffrectometry pattern indicated the transformation of granule into an amorphous state during modification and illustrated V-type.

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