• 제목/요약/키워드: 점착성

검색결과 742건 처리시간 0.024초

A Study for Perception of Hair Damage Using Friction Coefficient of Human Hair (모발의 마찰계수를 통한 모발 손상 인식 연구)

  • Lim, Byung Tack;Seo, Hong An;Song, Sang-Hun;Son, Seong Kil;Kang, Nae-Gyu
    • Journal of the Society of Cosmetic Scientists of Korea
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    • 제46권3호
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    • pp.295-305
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    • 2020
  • Treatment for beauty using oxidizing agents damages hair with inducing structural alteration in cuticle layer, degradation of protein, and loss of lipid. This study connects a frictional coefficient upon the damaged hair by an instrumental test to the texture test by human being, and considered a moisture as a factor of the damage. A friction coefficient has been measured upon the hair with successive treatment of dye, perm, and bleach. The friction coefficient from the hair dye-treated three times was defined with 0.60, where 58% of answerer indicated an initial damage point as the hairs of iteration of dye-treatment increased. Even bleach treated three times results in 0.84 of friction coefficient corresponding to 88% of answerer attributed the hair to an initially damaged hair. In order to figure out a lipid loss in hair for human being to respond damage, a friction coefficient of the hair was controlled by removing 18-methyleicosanoic acid (18-MEA). The initial damage has been recognized by 0.60 of the friction coefficient for the 68% of answerer. Since moisture is the largest portion of the components in hair, moisture analysis has been performed to study a relationship between texture of damage and the friction coefficient from an instrumental evaluation. As an iteration of dye increases, the hair became hydrophilic with smaller contact angle. It is found that a damaged hair by dyeing possessed more than 0.42% of moisture compared to a healthy hair. Finally, it is elucidated that an increase of moisture in hair induced higher adhesive force corresponding to the friction coefficient, and the friction coefficient above 0.6 is attributed to the preception of hair damage.

Effects of Maltogenic Amylase on Textural Properties of Dough and Quality Characteristics of White Pan Bread (Maltogenic Amylase가 식빵반죽의 물성과 식빵의 품질 특성에 미치는 영향)

  • Yoon, Seongjun;Cho, Namji;Lee, Soo-Jeong;Moon, Sung-Won;Jeong, Yoonhwa
    • Journal of the Korean Society of Food Science and Nutrition
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    • 제44권5호
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    • pp.752-760
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    • 2015
  • Effects of maltogenic amylase on textural properties of dough and quality characteristics of white pan bread were investigated. White pan bread was prepared with four different levels of maltogenic amylase contents (M-1: 0.048 U/g, M-2: 0.060 U/g, M-3: 0.072 U/g, M-4: 0.084 U/g). The setback by amylograph for the control was $480.0{\pm}12.25$ Brabender Unit (B.U.) while M-4 showed the a setback of $215.0{\pm}5.00B.U.$ The absorption, mixing tolerance index, and stability by farinogram were not significantly different (P>0.05) for across all treatments. The area under the curve (135 min) by extensogram was higher than all samples. The texture profile analysis results showed that there was significant decreasing in hardness for the maltogenic amylase infused bread (P<0.05). M-3 and M-4 showed higher springiness and cohesiveness but lower hardness than control over 1 to 3 days, indicating possibly extended shelf-life. Imaging scan showed that air cell size less than $0.4mm^2$ for the control and M-4 were at rates of 94.90% and 95.70%, respectively. For sensory evaluation, M-3 and M-4 showed higher intensities than the control for taste, flavor, texture, mouthfeel, and moistness quality. These results imply that the quality of white pan bread could be improved by adding maltogenic amylase without the use of chemical additives.

Effects of Hemicellulase on White Bread Added with Brown Rice Fiber (헤미셀룰라아제 첨가가 현미 식이섬유 식빵의 품질에 미치는 영향)

  • Yeom, Kyung-Hun;Bing, Dong-Joo;Kim, Mun-Yong;Chun, Soon-Sil
    • Journal of the Korean Society of Food Science and Nutrition
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    • 제45권3호
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    • pp.352-359
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    • 2016
  • White bread added with brown rice fiber was prepared by addition of 0.005, 0.010, 0.015, and 0.020% hemicellulase. Effects on product quality and sensory evaluation were examined. There were no significant differences in pH of dough before the 1st fermentation among the experiments. Dough made by addition of hemicellulase had a significantly higher pH after the 1st fermentation compared to the control group, whereas pH of bread had reverse effects. Fermentation power of dough expansion increased as incubation time increased. Addition of hemicellulase to samples significantly increased specific volume, baking loss, and water activity compared to the control sample. Moisture content was the lowest upon addition of 0.020% hemicellulase. For color, lightness was the highest in the control bread samples, greenness of the 0.015% addition sample was the lowest and yellowness of the 0.005% addition sample was the highest. For textural characteristics, hardness, gumminess, and chewiness were maximum in the control group. Cohesiveness and springiness were not significantly different between the samples. In the sensory evaluation, color, flavor, bran flavor, bitterness, astringency, and coarseness were not significantly different among the samples. Softness and overall acceptability were highest at the 0.020% addition level but lowest at the 0.010% level. The results indicate that addition of 0.020% hemicellulase to brown rice fiber white bread is optimal for quality and provides products with reasonably high overall acceptability.

Study on the Effectiveness of some Decontamination Agents against Skin Contamination of $^{137}Cs$ and $^{60}Co$ (제염제의 $^{137}Cs$$^{60}Co$에 의한 피부오염의 제염효과에 관한 연구)

  • Chon, Je-Keun;Ji, Pyung-Kook;Kwak, Sang-Soo;Kim, Byung-Tae;Park, Chong-Mook
    • Journal of Radiation Protection and Research
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    • 제23권1호
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    • pp.7-15
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    • 1998
  • In order to evaluate the effectiveness of some decontamination agents against skin contamination of $^{60}Co$ and $^{137}Cs$, the experiments were carried out in this study. In the experiments, pig skin was used instead of human skin , $^{60}CoC1_2$ and $^{137}CsCl$ were used the liquid sources of skin contamination. To examine the effectiveness of decontamination agents, skin decontamination was tried using soup, EDTA, KAERICON which was developed for decontamination of radionulides on the surface of building structure, and new decontamination agents such as IOCON, TRICON, and CHARCON, which were developed in this study. The absorption of radionuclides through the skin was evaluated by the gamma-tay detection on the surface of sample skin after radionuclides were penetrated into the skin during 16 hour soiling time. The results of this absorption experiment indicated that 11.5% and 3.2% of initial amounts of $^{137}Cs$ and $^{60}Co$, respectively, were panerated into the skin. In the experiment to remove the residual radioactivity fixed on the skin, KAERICON showed the decontamination rates up to 52.1%(decontamination factor of 2.1) and IOCON showed the equivalent decontamination rate (decontamination factor 1.9) for $^{137}Cs$. However, IOCON and CHARCON showed the poor decontamination rates of less than 20%(decontamination factor of 1.2) for $^{60}Co$, and KAERICON showed the poor decontamination rate (decontamination factor 1.1) for $^{60}Co$. For TRICON, the decontamination factors were 1.6 to 1.8 for $^{137}Cs$, and 1.0 to 1.2 for $^{60}Co$, respectively.

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A Study on Estimating Shear Strength of Continuum Rock Slope (연속체 암반비탈면의 강도정수 산정 연구)

  • Kim, Hyung-Min;Lee, Su-gon;Lee, Byok-Kyu;Woo, Jae-Gyung;Hur, Ik;Lee, Jun-Ki
    • Journal of the Korean Geotechnical Society
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    • 제35권5호
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    • pp.5-19
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    • 2019
  • Considering the natural phenomenon in which steep slopes ($65^{\circ}{\sim}85^{\circ}$) consisting of rock mass remain stable for decades, slopes steeper than 1:0.5 (the standard of slope angle for blast rock) may be applied in geotechnical conditions which are similar to those above at the design and initial construction stages. In the process of analysing the stability of a good to fair continuum rock slope that can be designed as a steep slope, a general method of estimating rock mass strength properties from design practice perspective was required. Practical and genealized engineering methods of determining the properties of a rock mass are important for a good continuum rock slope that can be designed as a steep slope. The Genealized Hoek-Brown (H-B) failure criterion and GSI (Geological Strength Index), which were revised and supplemented by Hoek et al. (2002), were assessed as rock mass characterization systems fully taking into account the effects of discontinuities, and were widely utilized as a method for calculating equivalent Mohr-Coulomb shear strength (balancing the areas) according to stress changes. The concept of calculating equivalent M-C shear strength according to the change of confining stress range was proposed, and on a slope, the equivalent shear strength changes sensitively with changes in the maximum confining stress (${{\sigma}^{\prime}}_{3max}$ or normal stress), making it difficult to use it in practical design. In this study, the method of estimating the strength properties (an iso-angle division method) that can be applied universally within the maximum confining stress range for a good to fair continuum rock mass slope is proposed by applying the H-B failure criterion. In order to assess the validity and applicability of the proposed method of estimating the shear strength (A), the rock slope, which is a study object, was selected as the type of rock (igneous, metamorphic, sedimentary) on the steep slope near the existing working design site. It is compared and analyzed with the equivalent M-C shear strength (balancing the areas) proposed by Hoek. The equivalent M-C shear strength of the balancing the areas method and iso-angle division method was estimated using the RocLab program (geotechnical properties calculation software based on the H-B failure criterion (2002)) by using the basic data of the laboratory rock triaxial compression test at the existing working design site and the face mapping of discontinuities on the rock slope of study area. The calculated equivalent M-C shear strength of the balancing the areas method was interlinked to show very large or small cohesion and internal friction angles (generally, greater than $45^{\circ}$). The equivalent M-C shear strength of the iso-angle division is in-between the equivalent M-C shear properties of the balancing the areas, and the internal friction angles show a range of $30^{\circ}$ to $42^{\circ}$. We compared and analyzed the shear strength (A) of the iso-angle division method at the study area with the shear strength (B) of the existing working design site with similar or the same grade RMR each other. The application of the proposed iso-angle division method was indirectly evaluated through the results of the stability analysis (limit equilibrium analysis and finite element analysis) applied with these the strength properties. The difference between A and B of the shear strength is about 10%. LEM results (in wet condition) showed that Fs (A) = 14.08~58.22 (average 32.9) and Fs (B) = 18.39~60.04 (average 32.2), which were similar in accordance with the same rock types. As a result of FEM, displacement (A) = 0.13~0.65 mm (average 0.27 mm) and displacement (B) = 0.14~1.07 mm (average 0.37 mm). Using the GSI and Hoek-Brown failure criterion, the significant result could be identified in the application evaluation. Therefore, the strength properties of rock mass estimated by the iso-angle division method could be applied with practical shear strength.

Effects of Polyimide Passivation Layers and polyvinylalcohol Passivation Layers for Organic Thin-Film Transistors(OTFTs) (폴리이미드 패시베이션과 폴리비닐알콜 패시베이션 레이어 성막이 고성능 유기박막 트렌지스터에 주는 영향)

  • Park, Il-Houng;Hyung, Gun-Woo;Choi, Hak-Bum;Hwang, Sun-Wook;Kim, Young-Kwan
    • Journal of the Korean Vacuum Society
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    • 제17권3호
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    • pp.195-198
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    • 2008
  • In this paper, it was demonstrated that organic thin-film transistors (OTFTs) were fabricated with the organic passivation layer by vapor deposition polymerization (VDP) processing. In order to form polymeric film as a passivation layer, VDP process was also introduced instead of spin-coating process, where polymeric film was co-deposited by high-vacuum thermal evaporation from 6FDA and ODA followed by curing. In order to investigate by compared with different passivation layer, the other OTFTs is fabricated to passivation by Polyvinylalcohol using spincoating. We can see that two different ways of passivation layer affect electric characteristic of OTFTs. The initial electric characteristic of OTFTs before passivation such as field effect mobility, threshold voltage, and on-off current ratio are $0.24cm^2/Vs$, -3V, and $10^6$, respectively. Then after polyimide passivation layer, field effect mobility change from $0.24cm^2/Vs$ to $0.26cm^2/Vs$, threshold voltage from -3V to 1V and on-off current ratio from $10^6$ to $10^6$, respectively. In the case of polyvinylalcohol passivation, the initial electric characteristic of OTFTs before passivation such as field effect mobility, threshold voltage, and on-off current ratio are $0.13cm^2/Vs$, 0V, and $10^6$, respectively. Then after polyvinylalcohol passivation layer, field effect mobility changes from $0.13cm^2/Vs$ to $0.13cm^2/Vs$, threshold voltage from 0V to 2V, and on-off current ratio from $10^6$ to $10^5$, respectively.

On the Histopathological Changes and Methemoglobinemia to Nitrite Toxicity in the Culture Farms of Eel, Anguilla japonica (참장어(뱀장어) Anguilla japonica 양어장(養魚場)에서의 아질산(亞窒酸) 중독(中毒)에 의한 Methemoglobin증(症)과 병리조직학적(病理組織學的) 변성(變性))

  • Yang, Han-Choon;Chun, Seh-Kyu
    • Journal of fish pathology
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    • 제4권1호
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    • pp.1-11
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    • 1991
  • Histopathological changes and methemoglobinemia of the eels (Anguilla japonica) reared at six culture farms in the vicinity of Y$\check{o}$su city were investigated under the conditions of $22.0{\sim}29^{\circ}C$, 4.33~7.33ppm of D.O., pH 6.1~8.2 and 0.03~10.1ppm of nitrite from December, 1989 to June, 1990. All of the eels showed no any abnormal state in action, color and blood, but the eels reared in pH 6.0 had planty of mucus and stickiness on their body surface. Methemoglobin levels were 1.03~9.86% of total erythrocyes in Dec. and 5.05~25.69% in June, and poikilocyte levels were 5.8~30.17% in Dec. and 8.67~74.45% in June. These results indicate the fact that the water management of the culture farms was worse in summer than in winter, even though not good in winter. Hypertrophy was found in the gill, hepatic and kidney tissue of the eels in all the culture farms. In March and June, Fish of all culture farms appeared the detachment of gill lamella epithelium cells, pyknosis and sinusoids of nucleus in the hepatic tissue and hemosiderosis in the kidney tissue. The trend of increase in methemoglobin levels appeared in the fish of culture farms with high nitrite concentration, which didn't appear equally in all the culture farms. However, in the culture farms of pH 6.0, methemoglobin and poikilocyte levels were increased independently of concentration of nitrite, and degeneration in the tissue of the gill, liver and kidney was also appeared.

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A Study on the Shear Characteristics of the Decomposed Granite Soils Using Direct Shear Test (직접전단시험(直接剪斷試驗)에 의한 화강토(花崗土)의 전단특성(剪斷特性)에 관(關)한 연구(硏究))

  • Lee, Dal Won;Kang, Yea Mook;Cho, Seong Seup
    • Korean Journal of Agricultural Science
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    • 제13권2호
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    • pp.227-242
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    • 1986
  • This paper describes the observed behavior in the direct shear test on decomposed granite soil having the complicate engineering properties at various different levels of factors. The objectives of this study were to investigate the characteristics of the decomposed granite soil under controlled various moisture content, dry density, strain rate and soaking which give influence to the shear strength. The results were summarized as follows; 1. The shear strength was decreased remarkably with the increasing of moisture contents of A and B soil were 5-10% and 15-20% respectively. 2. Cohesion and angle of internal friction were decreased with the increasing of moisture content and increased with the increasing of dry density. 3. The shear strength was increased with the increasing of normal stress and volume change was decreased on the whole. The shear strength was generally increased with the increasing of the strain rate. 4. As dry density increases, A-soil shows the progressive failure and the decrease of volume change while B-soil shows the initial failure and the increase of volume change. 5. The relationships between the soaked and unsoaked specimens were as follows ; ${\tau}_f=0.1009+1.026{{\tau}_f}^*$ (A-soil), ${\tau}_f=0.1586+0.8005{{\tau}_f}^*$ (B-soil) 6. Angle of internal friction of the direct shear test shows larger value than that of the triaxial compression test. All effective stress path was nearly similar.

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A Reliability Analysis of Shallow Foundations using a Single-Mode Performance Function (단일형 거동함수에 의한 얕은 기초의 신뢰도 해석 -임해퇴적층의 토성자료를 중심으로-)

  • 김용필;임병조
    • Geotechnical Engineering
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    • 제2권1호
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    • pp.27-44
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    • 1986
  • The measured soil data are analyzed to the descriptive statistics and classified into the four models of uncorrelated-normal (UNNO), uncorrelated-nonnormal (VNNN), correlatedonnormal(CONN), and correlated-nonnormal(CONN) . This paper presents the comparisons of reliability index and check points using the advanced first-order second-moment method with respect to the four models as well as BASIC Program. A sin91e-mode Performance function is consisted of the basic design variables of bearing capacity and settlements on shallow foundations and input the above analyzed soil informations. The main conclusions obtained in this study are summarized as follows: 1. In the bearing capacity mode, cohesion and bearing-capacity factors by C-U test are accepted for normal and lognormal distribution, respectively, and negatively low correlated to each other. Since the reliability index of the CONN model is the lowest one of the four model, which could be recommended a reliability.based design, whereas the other model might overestimate the geotechnical conditions. 2. In the case of settlements mode, the virgin compression ratio and preccnsolidation pressure are fitted for normal and lognormal distribution, respectively. Constraining settlements to the lower ones computed by deterministic method, The CONN model is the lowest reliability of the four models.

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Shattering Ratio of Manganese Nodule and Physical Properties of Powdered Manganese Nodule and Sea eottom Sediment (망간단괴의 분화율과 망간단괴 분말 및 해저퇴적물의 물리적 특성)

  • Choi, Hun-Soo;Kang, Jung-Seock;Chang, Se-Won;Koh, Sang-Mo;Um, In-Kwon
    • Journal of the Mineralogical Society of Korea
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    • 제20권4호
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    • pp.277-287
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    • 2007
  • To understand the effects of the powdered manganese nodule and sea bottom sediment pumped up with nodules on the mining process, the shattering ratio of manganese nodule and their physical properties are analyzed. The self shattering ratio and crushing shattering ratio are about 27% and about 3%, respectively. Then total shattering ratio is about 30%. The initial turbidity of the powdered manganese nodule and the bottom sediment show high, i.e., about 3,100 and 1,850 respectively. But their turbidities decrease rapidly with time. After 1 hour, turbidity of the powdered manganese nodule drops to about 1,570 and that of the bottom sediment to 1,310. The turbidity of Na-bentonite changes from 820 to 730 after 1 h and to 700 after 2 h. The viscosity of powdered manganese nodule is $1.4{\sim}1.5cP$, and the viscosity of bottom sediment is less than 1 cP. The viscosity fo Na-bentonite is initially 37.2 and increase with time to 86.4 cP after 30 min. The high initial turbidity of powdered manganese nodule is due to dark color of the powder. The high specific gravity makes rapid precipitation and then decreases the turbidity rapidly. The bottom sediment shows high initial turbidity because of easy suspension with very fine particle size. But it cannot be hydrated and formed gel in suspension, then it is easily precipitated. However Na-bentonite is hydrated to the expended state and makes gel state, then it shows high turbidity and high viscosity. These physical properties of the powdered manganese nodule suggest that the powder of manganese nodule should not make scaling inside of lifting pipe or pump. And the bottom sediment lifted up with manganese nodule should not play the role of drilling mud shch as Na-bentonite.