• 제목/요약/키워드: Size

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겔-케스팅한 알루미나 성형체에서 출발입도가 공정변수 및 성형 미세구조에 미치는 영향 (Effects of particle size on processing variables and green microstructure in gelcast alumina green bodies)

  • 하창기;김재원;조창용;백운규;정연길
    • 한국재료학회지
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    • 제11권10호
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    • pp.869-878
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    • 2001
  • Alumina $(Al_2O_3)$ green bodies were fabricated by gel-casting using three kinds of alumina with different particle size (mean particle size: 4.6 $\mu\textrm{m}$, 0.32 $\mu\textrm{m}$, 10nm). The effects of particle size on gel-casting process and green microstructure were investigated. The optimum dispersion conditions using ammonium salt (D-3019) as dispersant were 0.2 wt% (4.63 $\mu\textrm{m}$), 0.5 wt% (0.32 $\mu\textrm{m}$), and 5.0 wt% (10 nm), in high solid loading. The optimum solid loading of each starting material for gel-casting was obtained as 59 vol% (4.63 $\mu\textrm{m}$), 57 vol% (0.32 $\mu\textrm{m}$), 15 vol% (10 nm), depending on particle size, indicating that nano-size particle (10 nm) represent lower solid loading as high specific surface area than those of other two starting materials. The drying at ambient conditions (humidity; $\thickapprox$90%) was performed more than 48hrs to enable ejection of the part from the mold and then at $120^{\circ}C$ for 2hrs in an air oven, showing no crack and flaw in the dried green bodies. The pore size and distribution of the gelcast green bodies showed the significant decrease with decreasing particle size. Green microstructure was dependent on the pore size and distribution due to the particle size, and on the deairing step. The green density maximum obtained was 58.9% (4.63 $\mu\textrm{m}$), 60% (0.32 $\mu\textrm{m}$), 47% (10 nm) theoretical density (TD), and the deairing step applied before gel-casting did not affect green density.

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Fabrication of the Nano-Sized Nickel Oxide Powder by Spray Pyrolysis Process

  • Yu, Jae-Keun;NamGoong, Hyun;Kim, Dong-Hee
    • 한국재료학회지
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    • 제22권8호
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    • pp.426-432
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    • 2012
  • This study involves using nickel chloride solution as a raw material to produce nano-sized nickel oxide powder with average particle size below 50 nm by the spray pyrolysis reaction. The influence of the inflow speed of raw material solution on the properties of the produced powder is examined. When the inflow speed of the raw material solution is at 2 ml/min., the average particle size of the powder is 15~25 nm and the particle size distribution is relatively uniform. When the inflow speed of the solution increases to 10 ml/min., the average particle size of the powder increases to about 25 nm and the particle size distribution becomes much more uneven. When the inflow speed of the solution increases to 20 ml/min., the average particle size of the powder increases in comparison to the case in which the inflow speed of the solution was 10 ml/min. However, the particle size distribution is very uneven, showing various particle size distributions ranging from 10 nm to 70 nm. When the inflow speed of solution increases to 50 ml/min., the average particle size of the powder decreases in comparison to the case in which the inflow speed was 20 ml/min., and the particle size distribution shows more evenness. As the inflow speed of the solution increases from 2 ml/min. to 20 ml/min., the XRD peak intensities gradually increase, while the specific surface area decreases. When the inflow speed of solution increases to 50 ml/min., the XRD peak intensities rather decrease, while the specific surface area increases.

노년 여성 기성복 치수분석 뫼 체형별 맞음새에 관한 연구 (Size Analysis of Ready-made Clothing for Elderly Women and Fit Evaluation according to their Body Type)

  • 이정임;주소영
    • 한국의류학회지
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    • 제29권8호
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    • pp.1092-1101
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    • 2005
  • The purpose of this study is to analyze the size of ready-made clothing for elderly women and to evaluate their fit according to body type. Subjects were 33 women aged 60 and older, and they were classified by stature and drop index. The size of clothing which manufactured by four apparel brands were measured and compared with body size, and the size designation of four brands was compared. The questionnaire was carried out to subjects, and the size recognition and dissatisfaction with ready-made clothing were analyzed. The fitting test were carried out, and the subjects evaluated the fit of jackets and slacks of four brands. In the result of questionnaire, we found that subjects had little recognition about their clothing size. Subjects responded that they often felt dissatisfaction in their jacket length, sleeve length, shoulder width, bust girth, slacks, and waist girth. We found that each apparel brands had different sizing system and that even if the size designation of label was same, the clothing size was quite different. So the elderly women who didn't have so much knowledge about their own clothing size had a tendency to confuse with choosing proper clothing for themselves. In the wearer's evaluation, the significant difference in the degree of unsatisfaction were certified in several body parts according to wearer's body type. Especially, the degree of unsatisfaction in the case of subjects of having very small stature or very small hip was higher than other body types. From the result, we certified that it was necessary to consider the characteristics of each body type to increase the satisfaction of elderly women with clothing.

보행과 달리기 시 신발의 크기가 족저압과 지면반발력, 하지의 근피로에 미치는 영향 (Effect of Shoe Size on Foot Pressure, Ground Reaction Force, and Fatigue During Walking and Running)

  • 김택훈
    • 한국전문물리치료학회지
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    • 제15권1호
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    • pp.1-11
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    • 2008
  • The purpose of this study was to assess the influence of two shoe size conditions on foot pressure, ground reaction force (GRF), and lower extremity muscle fatigue. Seven healthy men participated. They randomly performed walking and running in two different conditions: proper shoe size and 10 mm greater than proper shoe size. Peak foot pressure, and vertical, anterior and mediolateral force components were recorded with the Parotec system and Kisler force platform. To assess fatigue, the participants performed treadmill running for twenty-five minutes twice, each time wearing a different shoe size. Surface electromyography was used to confirm localized muscle fatigue using power spectral analysis of four muscles (tibialis anterior, gastrocnemius medialis, rectus femoris, and biceps femoris). The results were as follows: 1) In walking conditions, there was a significantly higher peak pressure in the 10 mm greater than proper shoe size insole sensor 1, 2, 14, and 18 (p<.05). 2) In running conditions, there was a significantly higher peak pressure in the 10 mm greater than proper shoe size insole sensor 5, 14, and 15 (p<.05). 3) In walking conditions, there was a significantly higher first maximal vertical GRF in the 10 mm greater than proper shoe size (p<.05). 4) In running conditions, no GRF components were significantly different between each shoe size condition (p>.05). 5) Muscle fatigue indexes of the tibialis anterior and rectus femoris were significantly increased in the 10 mm greater than proper shoe size condition. These results indicate that wearing shoes that are too large could further exacerbate the problems of increased foot pressure, vertical GRF, and muscle fatigue.

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2·30대 저체중 여성의 상의 치수체계 제안 (A Suggestion of the Size-designation for the Underweight Women's Tops in their 20s-30s)

  • 임지영
    • 한국의류산업학회지
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    • 제15권3호
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    • pp.423-429
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    • 2013
  • This study helps out-size consumers purchase tops and improve the fitness of unde-weight women in their 20s-30s and by the establishment of a size system. The criteria for subjects in this study were those under 18.5($kg/m^2$) of the BMI; subsequently, a total of 233 females were enrolled. The results were: First, the nominal size for female adult formal dress suggested by the KS standard is suggested in 20 sections. The sections for underweight women are 7, (34 women who accounted for 14.59% out of 233 in total). The cover efficiency was 2.08% (which was very low). Second, tests showed that the average difference between the reference part body size of 7 sections for underweight women in the normal size section of bust cir.- hip cir.- height, and KS standard, waist cir. among reference sizes was rather small in the case of a nominal size for long height. Therefore, there is a significant difference with size in the KS standard and a sizing system proven improper for underweight woman. Third, the basic body sizes and reference body sizes were different due to the size system establishment according to measurements of underweight subjects. The research findings suggest that it is necessary to understand underweight types according to bust girth and hip girth sizes that represent basic sizes as well as to design patterns that consider the underweight body shape characteristics when women's tops are designed.

Fragmentation 프랙탈을 이용한 입도분포 분석 (Fragmentation Fractal Analysis on Particle-size Distribution)

  • 민덕기;이완진
    • 한국지반공학회논문집
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    • 제19권2호
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    • pp.199-206
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    • 2003
  • 흙을 나타내는 가장 기본적인 물리적 성질중의 하나가 흙을 구성하는 입자들의 입도분포이며, 입도분포특성을 분석하기 위해 최근에 대두되고 있는 방법중의 하나가 프랙탈 이론이다. 본 연구에서는 fragmentation 프랙탈을 이용하여 흙의 입도분포곡선의 특성을 파악하였다. Fragmentation 프랙탈을 표현하는 방법에는 ‘개수-입경’프랙탈과 '중량-입경' 프랙탈이 있으며, 본 연구 결과, '중량-입경' 방법이 더 실용적이었다. 균등계수($C_{u}$)가 4이하에서는 균등계수가 증가함에 따라 프랙탈차원($D_{tot}$)이 급격히 증가하였으나, 균등계수가 6이상에서는 일정한 값에 수렴되는 결과를 나타냈다. 곡률계수($C_{c}$)가 3이상에서는 프랙탈차원은 크기가 작은 입자들의 영향을 받고, 곡률계수가 3이하에서는 큰 입자들의 영향을 받는 것으로 나타났다. 유효입경($D_{10}$)의 크기에 따른 프랙탈차원의 변화를 분석한 결과, 균등계수와 곡률계수가 같을 경우 프랙탈차원은 유효입경의 크기에 영향을 거의 받지 않는 것으로 나타났다. 전체 입자의 크기분포를 고려할 수 있는 프랙탈 개념을 입도분석에 적용하는 것이 바람직할 것으로 판단되며, 향후 프랙탈차원과 흙의 공학적 특성과의 관계정립에 대한 지속적인 연구가 필요하다.

Relationship between Stress Gene Polymorphisms and Litter Size by AI in Pigs

  • Jin, H.J.;Kim, I.C.;Wee, M.S.;Yeon, S.H.;Kim, C.D.;Lee, S.S.;Cho, C.Y.;Cho, S.R.;Son, D.S.;Park, C.K.;Li, Z.D.
    • 한국수정란이식학회지
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    • 제22권4호
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    • pp.257-263
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    • 2007
  • This study was performed to investigate the relationship between PSS-HSP70 gene polymorphism and artificial insemination (AI) reproductivity in the pigs. The RFLP polymorphism of PSS and the SSCP polymorphisms of HSP70 K1, K3 and K4 PCR product were detected different patterns. In the experiment for AI of fresh semen, spring and fall season showed higher litter size born of 10.89 head than 10.47 head of summer season. Landrace was showed higher litter size of 9.96 head than that of Duroc and Yorkshire (p<0.05). Stress relating PSS and HSP70 polymorphism of PSS-Normal, HSP70 K1-BB, K3-AB, K4-AA showd a highest litter size born of 10.97 head and litter size born alive of 10.69 head than that of the other polymorphisms(p<0.05). In the experiment for AI of frozen semen, effects of season and pig breeds were not showed for litter size born. The stress relating polymorphism of PSS-Carrier, HSP70 K1-BB, K3-BB, K4-AB showed highest litter size born of 11.29 head and litter size born alive of 10.82 head and PSS-Normal, HSP70 K1-BB, K3-AB, K4-AA showed the lowest litter size born of 8.48 head and litter size born alive of 7.33 head than that of the other polymorphisms(p<0.05). These results suggest that AI litter size born for the stress of forzen thawed semen may be affected by PSS and HSP70 polymorphism in pigs.

Studies on Cocoon Filament Size Deviation in Multivoltine Breeds and Multivoltine ${\times}$ Bivoltine Hybrids of Silkworm, Bombyx mori L.

  • Rao, D.Raghavendra;Singh, Ravindra;Kariappa, B.K.;Dandin, S.B.
    • International Journal of Industrial Entomology and Biomaterials
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    • 제9권2호
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    • pp.273-277
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    • 2004
  • Variation in the size of the silk filament will determine the uniformity and quality of the silk reeled. In the present study, an attempt has been made to study the filament size variation in 6 multivoltine parental breeds and 9 multivoltine ${\times}$ bivoltine hybrids in all three seasons of a year. All multivoltine breeds and multivoltine ${\times}$ bivoltine hybrids showed variation in filament size throughout its length from the outer layer to inner layer. Results of the present study indicated that the size of the filament decreased from outer to inner layer. The decrease in filament size was sudden in some breeds/hybrids whereas it was gradual in other. Relationship between filament length to that of slope, average filament size to slope, and maximum filament size to slope was determined based on regression analysis. Regression analysis revealed significant positive correlation between slope vs average filament length (r=0.92$^{**}$) in multivoltine${\times}$bivoltine hybrids. Among parental breeds, 96C showed lowest slope of the curve (b-value: -0.00428) and 96A showed highest slope of the curve (b-value: -0.00269). Among 9 hybrids, PM${\times}$N $B_4$ $D_2$ recorded lowest slope value (b-value: -0.00328) and BL24${\times}$N $B_4$ $D_2$ showed highest value for slope of the curve (b-value: -0.00234). The breed 96C, which showed lowest slope value can be utilized for future breeding programmes to breed strains with less size deviation. Three multivoltine${\times}$bivoltine hybrids viz., PM${\times}$N $B_4$ $D_2$, 96E${\times}$CSR19 and BL67${\times}$CS $R_{101}$ , which showed less slope values (b-values: -0.00328, -0.00300 and -0.00297 respectively) can be utilized for commercial exploitation to produce uniform silk.k.

승강기 산업의 비표준 승강로에 대응하는 승강기 크기 결정 방법 연구 (Determination of Cage Size in Case of Non-Standard Well Size in Lift Industry)

  • 고영준;김병익;한관희
    • 융합정보논문지
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    • 제9권2호
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    • pp.85-93
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    • 2019
  • 현재 승강기의 크기에 관한 공인된 표준이 존재하지 않는다. 각 승강기 제조 회사들은 EN-CODE와 국내검사기준에서 정의하는 용량대비 최대사용 카 바닥 면적을 이용하여 승강기의 용량 산출 기준에 맞는 최대 허용 바닥 면적을 설정하고 자신들의 기준으로 승강기 크기를 결정하고 있다. 본 논문에서는 승강기 크기를 보다 쉽게 결정 할 수 있는 방법을 제시한다. 이를 위해 승강로의 치수를 입력하면 승강기의 크기를 계산해주는 프로그램을 구현하였다. 이 프로그램은 건물의 이미 결정된 승강로 크기에 따라 승강기 요소들을 고려하여 현재 사용 중인 EN-CODE와 국내검사기준에 맞는 승강기의 크기를 계산해 주어 빠른 의사결정과 승강기 설치에 있어서 유용한 도구가 될 것이라 사료된다.

The Effect of Kinesio Taping on Pain, Muscle Strength and Balance Control Ability by Age Group: A Literature Review

  • Lee, So-Jeong;Lee, Dongyeop;Hong, Ji-Heon;Yu, Jae-Ho;Kim, Jin-Seop;Kim, Seong-gil
    • The Journal of Korean Physical Therapy
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    • 제33권3호
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    • pp.142-147
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    • 2021
  • Purpose: The purpose of this study is to objectively and systematically investigate the effect of Kinesio taping by organizing and analyzing the research results using effect size. Methods: A total of 1,000 papers was searched, and 100 of them were selected the first time. Afterward, the effects of taping were analyzed and classified papers that studied balance, muscle strength, and pain, and finally 34 papers were selected. The effect size was calculated using the Effect Size Calculators (University of Colorado, USA) program. Statistical analysis was performed by using PASW Statistics software version 23.0 (IBM Co., Armonk, NY, USA). Descriptive statistics were used to obtain the effect size and confidence interval for each group. Results: In a study related to balance control ability, the effect size was 1.519 in the young subjects group (20-39 years old), and the effect size in the elderly group (65 years or older) was 0.360. In a study related to muscle strength, the effect size was 0.469 in the group of young subjects and 0.250 in the middle-aged group (40-65 years old), and the effect size of the elderly group was 0.848. In the study related to pain control, the effect size was 0.469 in the young group, the effect size of the middle-aged group was 0.972, and the effect size of the elderly group was 1.040. Conclusion: Kinesio taping differed in the degree of effect according to the age group of the subjects, but it was effective in balance control ability, muscle strength, and pain.