• Title/Summary/Keyword: Rigidity index

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Physicochemical and Rheological Properties of a Novel Emulsifier, EPS-R, Produced by the Marine Bacterium Hahella chejuensis

  • Yim Joung Han;Kim Sung Jin;Aan Se Hoon;Lee Hong Kum
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.9 no.5
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    • pp.405-413
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    • 2004
  • The rheological properties of an exopolysaccharide, EPS-R, produced by the marine bacterium Hahella chejuensis strain 96CJ 10356 were investigated. The $E_{24}$ of $0.5\%$ EPS-R was $89.2\%$, which was higher than that observed in commercial polysaccharides such as xanthan gum ($67.8\%$), gellan gum ($2.01\%$) or sodium alginate ($1.02\%$). Glucose and galactose are the main Sugars in EPS-R, with a molar ratio of ${\~}1:6.8$, xylose and ribose are minor sugar components. The average molecular mass, as determined by gel filtration chromatography, was $2.2{\times}10^3$ KDa, The intrinsic viscosities of EPS-R were calculated to be 16.5 and 15.9 dL/g using the Huggins and Kraemer equations, respectively, with a 2.3 dL/g overlap. In terms of rigidity, the conformation of EPS-R was similar to that of caboxymethyl cellulose ($5.0{\times}10^{-2}$). The rheological behavior of EPS-R dispersion indicated that the formation of a structure intermediate between that of a random-coil polysaccharide and a weak gel. The aqueous dispersion of EPS-R at concentrations ranging from 0.25 to $1.0\%$ (w/w) showed a marked shear-thinning property in accordance with Power-law behavior. In aqueous dispersions of $1.0\%$ EPS-R, the consistency index (K) and flow behavior index (n) were 1,410 and 0.73, respectively. EPS-R was Stable to pH and salts.

Exploration on Difficulty of Human Rights Process Conducted in Caretaker Workers of the Disabled Residential Facilities -Focused on the Caretaker Workers of the Disabled Residential Facilities in Busan- (장애인시설종사자의 인권수행과정의 어려움에 대한 탐색적 연구 -부산지역 장애인거주시설 종사자를 중심으로-)

  • Kim, Sunjoo
    • The Journal of the Korea Contents Association
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    • v.16 no.3
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    • pp.771-781
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    • 2016
  • This purpose of this study is to identify and conceptualize difficulty of abstract experiencing human rights process conducted in caretaker workers of the disabled residential facilities by utilizing multidimensional scaling. Focused on the caretaker workers of the disabled residential facilities in Busan, gathering a declarative sentence from caretaker workers, have classified index card. According to the results of the analysis, be reached name of six cluster. In facilities, caretaker workers was recognized Communication of the conflict between those People with intellectual disabilities, intention of service provider is not taken into account, those people emphasis to show up for caretaker workers, conflict based subjective human rights awareness of those People with intellectual disabilities. External facilities, interest in human rights is increasing becoming of pollution have difficulty to work hard time gaps between practice of human rights management and on-the-job experience, the rigidity of human rights investigation and inspection, lack of consideration for the caretaker workers. Based on this result, this study suggested a number of practical implications which can be used to reduce difficulty of human rights process conducted in the caretaker workers of the disabled residential facilities.

Effect of Coatings of Oxidized Starch on Properties of Linerboard (산화전분 코팅이 골판지 원지의 물성에 미치는 영향)

  • Ahn, Byoung-Kuk;Ahn, Won-Yung
    • Journal of the Korean Wood Science and Technology
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    • v.28 no.1
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    • pp.71-79
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    • 2000
  • Two linerboards consisting of corrugated board were coated with oxidized starch solutions to investigate the change of their properties and analyze the effect of coating on them. The coating of linerboards with oxidized starch resulted in improvement in the properties related to corrugated board properties by increasing fiber bonding and rigidity. The improvement of ring crush strength by coating was greater in inside linerboard than in outside linerboard. Burst index of linerboards rapidly increased with an initial increase of coating weight, but as the coating weight further increased, there was no increase in burst index. Coating on linerboards with oxidized starch at low coating weight improved stiffness of them. There were no significant changes in tearing resistance of linerboards by coating of oxidized starch. The coating resulted in increase in air resistance and sizing degree of linerboards.

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Regional Cerebral Perfusion in Progressive Supranuclear Palsy (진행성 핵상 마비에서의 국소 뇌혈류)

  • Lee, Won-Yong;Lee, Kyung-Han;Lee, Ki-Hyeong;Yoon, Byung-Woo;Lee, Myung-Chul;Lee, Sang-Bok;Jeon, Beom-S.
    • The Korean Journal of Nuclear Medicine
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    • v.30 no.1
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    • pp.47-55
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    • 1996
  • Progressive supranuclear palsy (PSP) is a parkinson-plus syndrome characterized clinically by supranuclear ephthalmoplegia, pseudobulbar palsy, axial rigidity, bradykinesia, postural instability and dementia. Presence of dementia and lack of cortical histopathology suggest the derangement of cortical function by pathological changes in subcortical structures in PSP, which is supported by the pattern of behavioral changes and measurement of brain metabolism using positron emission tomography. This study was done to examine whether there are specific changes of regional cerebral perfusion in PSP and whether there is a correlation between severity of motor abnormality and degree of changes in cerebral perfusion. We measured regional cerebral perfusion indices in 5 cortical and 2 subcortical areas in 6 patients with a clinical diagnosis of PSP and 6 healthy age and sex matched controls using $^{99m}Tc$-HMPAO SPECT. Compared with age and sex matched controls, only superior frontal regional perfusion index was significantly decreased in PSP (p<0.05). There was no correlation between the severity of the motor abnormality and any of the regional cerebral perfusion indices (p>0.05). We affirm the previous reports that perfusion in superior frontal cortex is decreased in PSP. Based on our results that there was no correlation between severity of motor abnormality and cerebral perfusion in the superior frontal cortex, nonmotoric symptoms including dementia needs to be looked at whether there is a correlation with the perfusion abnormality in superior frontal cortex.

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Study on Structure Design of High-Stiffness for 5 - Axis Machining Center (5축 공작기계의 고강성 구조설계에 관한 연구)

  • Hong, Jong-Pil;Gong, Byeong-Chae;Choi, Sung-Dae;Choi, Hyun-Jin;Lee, Dal-Sik
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.10 no.5
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    • pp.7-12
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    • 2011
  • This study covers the optimum design of the 5-axis machine tool. In addition, the intelligent control secures structural stability through the optimum design of the structure of the 5-axis machine center, main spindle, and the tilting index table. The big requirement, like above, ultimately leads to speed-up operation. And this is inevitable to understand the vibration phenomenon and its related mechanical phenomenon in terms of productivity and its accuracy. In general, the productivity is correlated with the operation speed and it has become bigger by its vibration scale and the operation speed so far. Vibration phenomenon and its heat-transformation of the machine is naturally occurred during the operation. If these entire machinery phenomenons are interpreted through the constructive understanding and the interpretation of the naturally produced vibration and heat-transformation, it would be very useful to improve the rapidity and its stability of the machine operation indeed. In this dissertation, the problems of structure through heating, stability, dynamic aspect and safety about intelligent 5-wheel machine tool are discovered to examine. All these discoveries are applied to the structure in order to enhance the density of it. It aims to improve the stability.

Inflammability Characteristics and Wear Comfort Property of Modacrylic Composite Yarn and Knitted Fabrics (난연 모다크릴 복합 방적사 니트소재의 방염성과 착용쾌적특성)

  • Kim, Hyunah
    • Journal of the Korean Society of Clothing and Textiles
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    • v.42 no.3
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    • pp.397-410
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    • 2018
  • This study investigated the flame retardant, anti-static property and wear comfort of knitted fabrics made of two kinds of composite yarns comprised of modacryl, antistatic PET, cotton and excel(R) fibers. A Low Oxygen Index (LOI) above 28 was observed in the modacryl knitted fabric specimens. The flame retardant was superior at the excel(R) fiber (including modacryl knitted fabric) than the one including cotton fiber. Anti-static properties of the modacryl knitted fabrics imbedded by 3wt% of antistatic PET fibers were observed by rubbing with wool fabric attached to the measuring apparatus, which showed a better anti-static property than the excel(R) fiber (including modacryl knitted fabric). Wear comfort indicated that quick perspiration absorption and the fast dry property of excel(R) (including modacryl knitted fabric) was better than one that included cotton fiber. Warmth keepability and breathability of the knitted fabrics indicated good results in the excel(R) (including cotton and the modacryl knitted fabrics). However, the tactile hand property of cotton fiber (including modacryl knitted fabric) was better than excel(R) fiber due to high extensibility and compressibility, and low bending and shear rigidity of the cotton fiber (including modacryl knitted fabrics).

Evaluation of Concrete-Track Deformation for High-Speed Railways by Characteristic Stiffness (강성특성치를 이용한 고속전철 콘크리트궤도의 처짐가능성 평가)

  • Joh, Sung-Ho;Lee, Il-Wha;Hwang, Seon-Keun;Kang, Tae-Ho;Kim, Seok-Chul
    • Proceedings of the KSR Conference
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    • 2009.05b
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    • pp.641-646
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    • 2009
  • Concrete tracks are superior to ballast tracks in the aspect of durability, maintenance and safety. However, deteriorated stiffness of railroad bed and settlement of soft ground induced by trapped or seepage water lead to problems in safety of train operation. In this research, characteristic stiffness of concrete tracks, which is determined from FRACTAL (Flexural-Rigidity Assessment of Concrete Tracks by Antisymmetric Lamb Waves) technique, was employed as an index of track displacement. The characteristic stiffness is defined using Poisson's ratio, moment of inertia and stiffness ratio of subgrade to slab. To verify validity and reliability of the proposed characteristic stiffness, experimental and theoretical researches were performed. Feasibility of the characteristic stiffness based on FRACTAL technique was proved at a real concrete track for Korean high-speed trains. Validity of the FRACTAL technique was also verified by comparing the results of impulse-response tests performed at the same measurement array and the results of SASW tests and DC resistivity survey performed at a shoulder nearby the track.

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Initial Excess Pore Pressure Induced by Cone Penetration in Normally Consolidated Clays (정규압밀점토에서의 피에조 콘 관입에 의한 과잉간극수압에 대한 연구)

  • 임형덕;이우진;김대규
    • Journal of the Korean Geotechnical Society
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    • v.19 no.1
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    • pp.151-161
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    • 2003
  • In this study, an interpretation method is proposed to evaluate the stress conditions, including individual excess pore pressure components ($\Delta{u}_{oct}$/ and $\Delta{u}_{shear}$), of normally consolidated clay elements adjacent to the cone face. It is assumed that the stress path of triaxial compression is representative f3r that of the soil element and the soil is elastic-perfectly plastic material. The proposed method is applied to the results of miniature piezocone tests conducted at Louisiana State University calibration chamber system. Based on the results of interpretation, it was found that the ratio of $\Delta{u}_{oct}$/ $\Delta{u}$and $\Delta{u}_{shear}$/$\Delta{u}$ estimated by the proposed method is affected only by the pore pressure parameter. The proposed method gives consistent and reliable values of $\Delta{u}_{oct}$/ $\Delta{u}$and $\Delta{u}_{shear}$/$\Delta{u}$ compared with early works, whereas those obtained by other solutions are significantly dependent on the accuracy in estimating soil properties such as undrained shear strength and rigidity index.

The Effect of Pile Length on the Handle and Physical Properties of Velvet (Velvet의 pile 길이가 촉감 및 물리적 특성에 미치는 영향)

  • 장정애;류덕환
    • Journal of the Korean Society of Clothing and Textiles
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    • v.19 no.3
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    • pp.471-482
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    • 1995
  • Using the acetate velvet and viscose velvet whose pile lengths were sheared as 1.45, 1.55, 1 65, 1.75, 1.85, 1.90mm under the condition equating the weaving process of ground fabric, the conclusions were as follows through the results of the sensory assessments estimated by women students in our university and the physical properties, H. V and T. H. V obtained by KES-F system. 1. In the sensory assessments estimated by the method of paired comparison and ranking of samples, the longer pile length was, the more the hand values of smoothness, softness, thickness, heaviness increased on the whole. 2. The H V. and T. H. V. measured by KES-F system were as follows; Kohi increased to pile length 1.85mm and then decreased a little at 1.90mm. hummer increased as pile length was longer. Fukurami increased to pile length 1.75mm and then decreased gradually as pile length was longer. Total hand value increased gradually from 1. 45mm to 1.85mm, had the top value at 1.85mm, and then decreased a little at 1.90mm. 3. In the results of summarizing $\ulcorner$the physical properties correlated closely with the H. V obtained by sensory assessments$\lrcorner$ and tithe Physical properties correlated closely with the H. V. and T. H. V obtained by KES-F systems, it showed that all the sensory properties correlated closely with compressive energy, flexural rigidity, thickness, weight and pile ratio in the former and that the physical properties correlated closely with each H V and T. H. V were different in the latter. 4. It showed that factor 1 was related to compressive energy, thickness, weight, pile ratio, factor 2 was related to recovery energy, compressive resilience, compressive index, and factor 3 was related to compressive recovery ratio in the result of factor analysis. 5. In the multiple repression analysis, the expressions of all sensory properties had compressive ratio, frictional coefficient in the regression expressions of $\ulcorner$H. V. obtained by sensory assessments$\lrcorner$, while the expressions of each H. V. and different physical properties in the regression expressions of $\ulcorner$H. V. obtained by KES-F system$\lrcorner$.

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Determination of Horizontal Coefficient of Consolidation from the Self-boring Pressuremeter Holding Test by Considering Pore Pressure Dissipation Trend (간극수압 소산경향을 고려한 자가굴착식 프레셔메터로부터의 수평압밀계수 결정법)

  • 김영상
    • Journal of the Korean Geotechnical Society
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    • v.20 no.3
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    • pp.151-159
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    • 2004
  • This paper describes a systematic way of identifying the horizontal coefficient of consolidation of clayey soil by applying an optimization technique to the early part of dissipation data measured from the self-boring pressuremeter strain holding test. An analytical solution developed by Randolph & Wroth (1979) was implemented in normalized form to express the build-up of excess pore pressures as a function of the rigidity index and subsequent dissipation of excess pore pressures around a pressuremeter Horizontal coefficient of consolidation was determined by minimizing the differences between theoretical and measured excess pore pressure curves over 50% degree of dissipation range using optimization technique. The effectiveness of the proposed back-analysis method was examined against the real fled performances obtained from pressuremeter strain holding tests at Gimje and Yangsan site. It is shown that the proposed back-analysis method can evaluates the rational horizontal coefficient of consolidation, which is similar to those obtained from the piezocone dissipation test. Furthermore, proposed method can evaluate appropriate coefficient of consolidation for soil under partially drained condition.