• Title/Summary/Keyword: Evenness

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Effect of Drawing Parameters on the evenness of C/P Blended Rovings

  • Kim Gyu-Ho;Lee Dae-Hun;Ju Chang-Hwan
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.10a
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    • pp.398-401
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    • 1998
  • The evenness of roving is greatly important fur the improvement of quality in final yarns. In order to produce even rovings, all fibers would have to be uniformly distributed over the whole rovings. However, that is ruled out by the inhomogeneity of fiber materials aid by the mechanical constraint. Accordingly, there are limits to the achievable fiber assembly evenness. Also, since the evenness of roving has greatly influenced on the evenness of slivers in drawing process, the optimum condition of drawing process is very important. (omitted)

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Correlation Among Items of Mechanical Tests in Raw Silk (생사기계검사 항목간의 상관관계)

  • 김영진;정지현;조동옥;이덕노
    • Journal of Sericultural and Entomological Science
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    • no.11
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    • pp.73-80
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    • 1970
  • This study was carried out in order to investigate the correlation among test items of export raw silk. The results obtained from the study are summarized as follows. 1. The highest correlation was between evenness and low evenness in case of the filaments made of autumn cocoons and the coefficient of correlation was 0.854. 2. Among following items, viz.; evenness and cleanness, neatness and low neatness and elongation and cohesion, the correlation phisically was not acknowledged, but the coefficients of correlation were high figures. 3. Poor correlation existed between following items, viz.; size deviation and maximum deviation, evenness and low evenness, neatness and low neatness, cleanness and low neatness. 4. It is considered that the high correlation exists between tenacity and elongation, but in this study the correlation existed among some items. 5. In this study it is a new fact that the correlation between neatness and cohesion as well as low neatness and tenacity existed enough highly. 6. As a conclusion the independence of ten items tested at present was acknowledged.

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The Evaluation of Evenness of Nonwovens Using Image Analysis Method

  • Jeong, Sung-Hoon;Kim, Si-Hwan;Hong, Cheol-Jae
    • Fibers and Polymers
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    • v.2 no.3
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    • pp.164-170
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    • 2001
  • Authors studied on the applicability of image analysis technique using a scanner with a CCD (charged coupled deviced) to the evaluation of evenness of nonwovens because it has distinctive features to considerably save time and labor in the analysis compared with other classical methods. As specimens fur the experiment, two different types that are unpatterned and patterned ones were prepared. For the unpatterned specimen, webs were chemically bonded, while for the patterned specimen, webs being thermally calendered with engraved roller. Several webs having various areal densities were prepared and bonded. Coefficient of variation (CV%) was used as a parameter to evaluate the evenness. Scanning conditions could be suitably set up through comparing the total variance to the between-group variance and to the within-group variance, respectively, on the images scanned at the different conditions. The 2D convolution method with smoothing filter kernel was introduced to further filter the noises on the scanned images. After the filtering process, the increase of web areal densities gave an uniform decrease of the CV%. This showed that the scanned image analysis with proper filtering process could be successfully applicable to the evaluation of evenness in nonwovens.

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Study on Phosphate Investment for High Temperature Precision Castings(I);The Effect of Particle size and Distribution of Silica Sand on the characteristics of the Investment (고온정밀주조용 인산염계 매몰재에 관한 연구(I);매몰재의 특성에 미치는 규사의 입도와 입도분포의 영향)

  • Ahn, Ji-Hong;Lee, Jong-Nam
    • Journal of Korea Foundry Society
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    • v.5 no.2
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    • pp.85-96
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    • 1985
  • In order to investigate the effect of particle size and distribution of silica sand on the characteristics of investment, W/P ratio, setting time, temperature change during setting, setting expansion, thermal expansion and compressive strength of the investments were measured. In this experiment, magnesia clinker and mono ammonium phosphate were used as binder, and particle size and distribution of silica sand were classified for convinence into 10 categories. The main results obtained from this investigation were summerized as follows. 1. W/P ratio decreased with increase of particle size and evenness in distribution of sand grain. 2. Setting time decreased with increase of evenness in distribution of sand grain, and temperature during setting increased with evenness in distribution of sand grain. 3. Setting expansion decreased with increase of particle size, while it increased with evenness in distribution of sand grain. 4. Thermal expansion decreased with increase of particle size. 5. Compressive strength increased with increase of particle size and evenness in distribution of sand grain. From above results, G.F.N. 250 sand which contains 30% of 50-100 mesh could be recommended for investment casting.

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Effects of Dietary Habits and Nutrient Intakes on Skin Condition of Female University Students (여대생의 식습관과 영양소 섭취상태가 피부상태에 미치는 영향)

  • Jo, Hyun-Ju;Choi, Mi-Ja
    • Journal of Nutrition and Health
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    • v.43 no.3
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    • pp.233-245
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    • 2010
  • The purpose of this study was to investigate the effects of dietary habits and nutrient intakes on skin condition of female university students. The subjects were 95 female university students in Daegu. This study examined anthropometric measurements, dietary intake, food intake habits and skin condition (moisture, elasticity, sebum (U-zone, T-zone), pores, evenness and melanin pigmentation. The subjects in this study had an average age of 21.4, an average height and weight of 161.2 cm and 52.9 kg, respectively, and the average body mass index (BMI) was 20.3 $kg/m^2$. The means of skin elasticity, pores, evenness, and melanin pigmentation were within the normal range of women in their 20s and the skin moisture state was slightly lower than the normal range, which showed a dry tendency. The sebum in the U-zone and the T-zone was lower than the standard values, which showed less secretion in both areas. The subjects with high nut intake showed a better skin pore state (p < 0.05). Those with a high intake of instant foods showed a sig-nificantly low skin moisture and a significantly higher sebum rate (p < 0.05). The group with high skin elasticity and the group with less melanin pigmentation showed a significantly low animal protein intake (p < 0.05). The group with high skin elasticity also showed a significantly higher vitamin A and niacin intakes as well (p < 0.05). The group with high skin evenness showed a significantly lower animal lipid intake and a significantly higher vitamin E intake (p < 0.05). In addition, those with high skin elasticity and evenness as well as low melanin pigmentation showed a tendency of high intake of antioxidant vitamins, such as vitamin A, carotene, vitamin C or vitamin E. In summary, a moderate intake of plant-based products and also the antioxidant vitamins within such products seems to have a beneficial effect on maintaining a healthy and good skin condition.

Diversity of Subcortical Arthropod Communities in Tropical and Temperate Forests

  • Choe, Jae-Chun
    • Animal cells and systems
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    • v.1 no.4
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    • pp.577-581
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    • 1997
  • Species diversity of subcortical arthropod communities were assessed in two tropical regions and two temperate regions. In the tropics, communities of subcortical arthropods were more diverse in La Selva, Costa Rica, than on Barro Colorado Island, Panama. Costa Rican communties yielses higher values of both Shannon and Simpson diversity indices than Panamanian communities. Compared to Panamanian communities, Costa Rican ones supported higher measures of both species richness and evenness. Between the two temperate regions, communities of subcortical arthropods in Korea scored consistently higher values of both Shannon and Simpson indices than the ones in eastern Massachusetts, U.S.A. When individual diversity components were compared, however, Korean communities yielded exceptionally high evenness measures but lower species richness than the communities in the U.S.A. Unusually high evenness values of Korean subcortical arthropods were due to extremely low population densities of all component species.

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Study on Manufacturing Technology of Coating Yarns for Awning Fabrics (차양막 직물용 코팅사 제조기술에 관한 연구)

  • Kim, Seung-Jin;Lee, Eun-Ho;Heo, Kyeung;Kim, Hyun-Ah
    • Textile Coloration and Finishing
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    • v.27 no.1
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    • pp.35-49
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    • 2015
  • This paper investigated optimum process conditions of coating yarn for awning fabric. For this purpose, the simulation for processability and yarn quality using SPSS statistics package was carried out, and PP/TPO and PET/PVC coating yarns specimens were made with variation of extruder temperature and feed speed of core yarn on the yarn coating machine for examining simulation result. It was revealed that optimum coating conditions of PP/TPO 1000d coating yarn were extruder temperature $150^{\circ}C$, and core yarn feed speed 400~500m/min. Mechanical property and thermal shrinkage of PP/TPO coating yarn made at this conditions were best and core evenness rates of these coating yarns by yarn compression tester were also superior, which was certified by SEM photograph. In addition, these experimental results were coincided with simulation results. It was found that, in PET/PVC coating yarn, yarn physical properties between 1500d and 1200d coated yarns were not shown any difference, and core evenness rates of these coating yarns were superior. It revealed and concluded that these simulated coating conditions are applicable to production field.

The Statistical Analysis of Raw Silk Quality Control in Korea (우리나라 생사품질관리의 통계적분석)

  • 남중희;최병희
    • Journal of Sericultural and Entomological Science
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    • v.17 no.1
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    • pp.69-74
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    • 1975
  • This report was aimed to examine the status of raw silk quality and to come up with means of the good quality silk production by use of the statistical quality control method. The results obtained are as follow : 1) The raw silk quality of size 20/22 denier was found to be 2A grade during the last five years. 2) In order to level up the silk grade, the better quality control is required especially in the average evenness and cleanness. 3) It was found that winding brakes and elongation of silk threads have been versed gradually through the period. 4) Larger variation was observed in cleanness control chart, but low evenness have stayed with in the desirable control range.

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Factors influencing the penetration kinetics of PVAm solution in z-direction of paper (PVAm 용액 종이 두께 방향 침투 kinetics에 영향하는 인자들)

  • Cho, Byoung-Uk;Won, Jong-Myoung;Moon, Eun-Sik;Choi, Do-Chim
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2011.04a
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    • pp.31-35
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    • 2011
  • Factors influencing penetration kinetics of PVAm solution into paper were investigated with ultrasonic Penetration Evenness Analyzer (PEA). Paper structure was varied by changing basis weight, freeness of pulp, calendering, number of plies and filler addition and hydrophobicity of paper was varied by adding AKD. Important factors affecting liquid penetration are found to be pore structure and hydrophobicity of paper. Pore structure of paper can be designed by controlling refining degree and filler addition. Hydrophobicity of paper can be controlled by internal sizing.

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