• Title/Summary/Keyword: coat

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An Analysis of the Polymer Melt Flow in Extruder Dies (고분자압출 다이스의 유동해석)

  • Choi, Man Sung;Kim, Kwang Sun
    • Journal of the Semiconductor & Display Technology
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    • v.12 no.2
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    • pp.19-25
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    • 2013
  • Extrusion is one of the most important operations in the polymer-processing industry. Balancing the distribution of flow through a die to achieve a uniform velocity distribution is the primary objective and one of the most difficult tasks of extrusion die design. If the manifold in a coat-hanger die is not properly designed, the exit velocity distribution may be not uniform; this can affect the thickness across the width of the die. Yet, no procedure is known to optimize the coat hanger die with respect to an even velocity profile at the exit. While optimizing the exit velocity distribution, the constraint optimization used in this work with allowable pressure drop in the die; according to this constraint we can control the pressure in the die. The computational approach incorporates three-dimensional finite element simulations software STAR-CCM+. These simulations are used with numerical optimization to design polymer coat hanger dies with pressure drop, uniform velocity and temperature variation across the die exit.

Antimicrobial Potential of Moringa oleifera Seed Coat and Its Bioactive Phytoconstituents

  • Arora, Daljit Singh;Onsare, Jemimah Gesare
    • Microbiology and Biotechnology Letters
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    • v.42 no.2
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    • pp.152-161
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    • 2014
  • The in vitro antimicrobial potential of the unexplored Moringa oleifera seed coat (SC) was evaluated against some Gram-positive and Gram-negative bacteria and yeast pathogens. Antimicrobial studies with various solvent extracts indicated ethyl acetate to be the best extractant, which was used for the rest of the antimicrobial studies as it tested neither toxic nor mutagenic. Gram-positive bacteria including a methicillin resistant Staphylococcus aureus (MRSA) strain were more susceptible with a minimum inhibitory concentration (MIC) range of 0.03-0.04 mg/ml. The antimicrobial pharmacodynamics of the extract exhibited both concentration-dependent and time-dependent killing. Most of the test organisms exhibited a short post antibiotic effect (PAE) except Enterococcus faecalis, Staphylococcus aureus, and Klebsiella pneumoniae 1, which exhibited longer PAEs. Amongst the major phytoconstituents established, flavonoids, diterpenes, triterpenes and cardiac glycosides exhibited inhibitory properties against most of the test organisms. The identified active phytochemicals of the M. oleifera seed coat exhibited antimicrobial potential against a wide range of medically important pathogens including the multidrug-resistant bugs. Hence, the M. oleifera seed coat, which is usually regarded as an agri-residue, could be a source of potential candidates for the development of drugs or drug leads of broad spectrum that includes multidrug-resistant bugs, which are one of the greatest concerns of the $21^{st}$ century.

Analysis of Adhesion Characteristics of Solid Propellants by Kind of Barrier Coat (접착 보조제 종류에 따른 고체 추진제 접착 특성 분석)

  • Jang, Myungwook;Koo, Myungjun;Yun, Jaeho;Lee, Dug Bum
    • Journal of the Korean Society of Propulsion Engineers
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    • v.24 no.4
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    • pp.33-40
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    • 2020
  • A sturdy on the adhesion properties of solid propellants, liners, and insulation was carried out according to the types of barrier coats. A barrier coats were used to prevent migration of the plasticizer or curative between the propellant/liner/insulation, and the barrier coat was selected out of Isocyanates with different molecular weight and number of -NCO in one molecule. As a result, it was found that the more the -NCO group and the larger molecular weight, the stronger adhesion. In addition, as a result of experiments about effects of the pot life after applying the barrier coat on bond strength, the adhesion strength was shown to increase as the pot life was short.

Expression and Distribution of the Guanine Nucleotide-binding Protein Subunit Alpha-s in Mice Skin Tissues and Its Association with White and Black Coat Colors

  • Yin, Zhihong;Zhao, Xin;Wang, Zhun;Li, Zhen;Bai, Rui;Yang, Shanshan;Zhao, Min;Pang, Quanhai
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.10
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    • pp.1392-1397
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    • 2016
  • Guanine nucleotide-binding protein subunit alpha-s ($Gn{\alpha}s$) is a small subunit of the G protein-couple signaling pathway, which is involved in the formation of coat color. The expression level and distribution of $Gn{\alpha}s$ were detected by quantitative real-time-polymerase chain reaction (qPCR), western blot, and immunohistochemistry to investigate the underlying mechanisms of coat color in white and black skin tissues of mice. qPCR and western blot results suggested that $Gn{\alpha}s$ was expressed at significantly higher levels in black mice compared with that of white mice, and transcripts and protein possessed the same expression in both colors. Immunohistochemistry demonstrated $Gn{\alpha}s$ staining in the root sheath and dermal papilla in hair follicle of mice skins. The results indicated that the $Gn{\alpha}s$ gene was expressed in both white and black skin tissues, and the expression level of $Gn{\alpha}s$ in the two types of color was different. Therefore, $Gn{\alpha}s$ may be involved in the coat color formation in mice.

A Numerical Analysis on the Freeze Coating of a Non-Isothermal Flat Plate with a Binary Alloy (비등온 평판의 이성분 합금 냉각코팅에 관한 수치해석)

  • Nam, Jin-Hyeon;Kim, Chan-Jung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.11
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    • pp.1437-1446
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    • 2000
  • A numerical analysis on the freeze coating process of a non-isothermal finite dimensional plate with a binary alloy is performed to investigate the growth and decay behavior of the solid and the mushy layer of the freeze coat and a complete procedure to calculate the process is obtained in this study. The continuously varying solid and mushy layers are immobilized by a coordinate transform and the resulting governing differential equations are solved by a finite difference technique. To account for the latent heat release and property change during solidification, proper phase change models are adopted. And the convection in the liquid melt is modeled as an appropriate heat transfer boundary condition at the liquid/mushy interface. The present results are compared with analytic solutions derived for the freeze coating of infinite dimensional plates and the discrepancy is found to be less than 0.5 percent in relative magnitude for all simulation cases. In addition the conservation of thermal energy is checked. The results show that the freeze coat grows proportional to the 1.2 square of axial position as predicted by analytic solutions ar first. But after the short period of initial growth, the growth rate of the freeze coat gradually decreases and finally the freeze coat starts to decay. The effects of various non-dimensional processing parameters on the behavior of freeze coat are also investigated.

Accumulation of triple recessive alleles for three antinutritional proteins in soybean with black seed coat and green cotyledon

  • Kang, Gyung Young;Choi, Sang Woo;Chae, Won Gi;Chung, Jong Il
    • Journal of Plant Biotechnology
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    • v.47 no.2
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    • pp.118-123
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    • 2020
  • The black seed coat of soybeans contain anthocyanins which promote health. However, mature soybean seeds contain anti-nutritional factors like lipoxygenase, lectin and Kunitz Trypsin Inhibitor (KTI) proteins. Furthermore, these seeds can be used only after the genetic elimination of these proteins. Therefore, the objective of this study was to develop novel soybean genotypes with black seed coat and triple recessive alleles (lx1lx1lx2lx2lx3lx3, titilele) for lipoxygenase, lectin, and KTI proteins. From a cross of parent1 (lx1lx2lx3/lx1lx2lx3, ti/ti, Le/Le) and parent2 (lx1lx2lx3/lx1lx2lx3, Ti/Ti, le/le), 132 F2 seeds were obtained. A 3:1 segregation ratio was observed during F2 seed generation for the inheritance of lectin and KTI proteins. Between a cross of the Le and Ti genes, the observed independent inheritance ratio in the F2 seed generation was 9: 3 : 3 : 1 (69 Le_Ti_: 32 leleTi_: 22 Le_titi: 9 leletiti) (χ2=2.87, P=0.5 - 0.1). From nine F2 seeds with triple recessive alleles (lx1lx1lx2lx2lx3lx3, titilele genotype), one novel strain posessing black seed coat, and free of lipoxygenase, lectin and KTI proteins, was selected. The seed coat color of the new strain was black and the cotyledon color of the mature seed was green. The weight of 100 seeds belonging to the new strain was 35.4 g. This black soybean strain with lx1lx1lx2lx2lx3lx3, titilele genotype is a novel strain free of lipoxygenase, lectin, and KTI proteins.

Construction of ELISA System for the Detection of Indian citrus ringspot virus (Indian citrus ringspot virus의 ELISA 진단 시스템 구축)

  • Shin, Myeung-Ju;Kwon, Young-Chul;Ro, Hyeon-Su;Lee, Hyun-Sook
    • Research in Plant Disease
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    • v.18 no.3
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    • pp.231-235
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    • 2012
  • Indian citrus ring spot virus (ICRSV) is known to cause a serious disease to citrus, especially to Kinnow mandarin, the popular cultivated citrus species in India. In this study, we developed diagnostic systems based on enzyme-linked immunosorbent assay (ELISA). In order to generate antibodies against ICRSV coat protein, we overexpressed the coat protein in Escherichia coli using the pET15b expression vector containing an optimized ICRSV coat protein gene. The recombinant ICRSV coat protein was overexpressed as soluble form at $37^{\circ}C$ upon IPTG induction. The protein was purified to 95% in purity by Ni-NTA column chromatography. The purified protein was immunized to rabbit for the generation of polyclonal antibody (PAb). The PAb showed a specific immunoreaction to recombinant ICRSV coat protein in western blot analysis and ELISA. Diluted rabbit antisera (10,000 fold) could detect less than 10 ng and 5 ng of the target protein in western blot and ELISA analysis, respectively.

Fine Structural Investigations of Fertilization Envelopes and Acrosomal Reaction in Urechis unicinctus (Urechis unicinctus 수정막과 첨체반응에 대한 미세구조적 관찰)

  • Kwon, Hyuk-Jae;Shin, Kil-Sang;Kim, Wan-Jong
    • Applied Microscopy
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    • v.30 no.1
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    • pp.61-72
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    • 2000
  • Three fertilization envelopes (FE) have been observed after the artificial insemination of U. unicinctus oocytes. The substances of the first fertilization envelope, which is an effective barrier against excessive sperm, come mainly from the surface coat of the oocyte. The secretions of the cortical granules take part in formation of the 2nd fertilization envelope. Histologically, the 3rd fertilization envelope is not amorphous as seen under light microscope, but contains numerous panicles under electron microscope, which would be contributed to harden the envelope by 60 min after the fertilization. With the substantial similarity between the 1st fertilization envelope and the surface coat of the oocyte, and the coincidence of retraction of microvilli and the formation of the 1st fertilization envelope, it is suggested that the microvilli contain the sperm receptors in U. unicinctus. Some granular substances from the distal part of the acrosome diffuse on the surface coat of the oocyte while the acrosomal tubules penetrate into the surface coat. The acrosomal tubules arise from the proximal part of the acrosome and pass through the acrosomal lumen.

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The Safety and Pharmacokinetics of Cyanidin-3-Glucoside after 2-Week Administration of Black Bean Seed Coat Extract in Healthy Subjects

  • Jeon, Sang-Il;Han, Seung-Hoon;Lee, Jong-Tae;Hong, Tae-Gon;Yim, Dong-Seok
    • The Korean Journal of Physiology and Pharmacology
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    • v.16 no.4
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    • pp.249-253
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    • 2012
  • We analyzed the pharmacokinetics of C3G on data from twelve subjects, after 2-week multiple dosing of black bean (Phaseolus vulgaris, Cheongjakong-3-ho) seed coat extract, using the mixed effect analysis method (NONMEM, Ver. 6.2), as well as the conventional non-compartmental method. We also examined the safety and tolerability. The PK analysis used plasma concentrations of the C3G on day 1 and 14. There was no observed accumulation of C3G after 2-week multiple dosing of black bean seed coat extract. The typical point estimates of PK were CL (clearance)=3,420 l/h, V (volume)=7,280 L, Ka (absorption constant)=9.94 $h^{-1}$, ALAG (lag time)=0.217 h. The black bean seed coat extract was well tolerated and there were no serious adverse events. In this study, we confirmed that a significant amount of C3G was absorbed in human after given the black bean seed coat extract.

Development and Evaluation of Polymer-Modified Asphalt Emulsions Used for Tack Coats (택코트용 폴리머 개질 유화아스팔트 개발 및 성능 평가)

  • Kim, Yeong Min;Im, Jeong Hyuk;Hwang, Sung Do
    • International Journal of Highway Engineering
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    • v.17 no.2
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    • pp.39-46
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    • 2015
  • PURPOSES: The objectives of this study were to develop a new polymer-modified emulsion for application to tack coats and to evaluate its properties by comparing it with other types of asphalt emulsions, with the goal of providing an enhanced tack coat material for use in construction. METHODS: Modified asphalt binders were developed from using SBS and SBR latex in the laboratory, and their fundamental properties, such as their penetration index and PG grade, were evaluated. Based on the properties, a new tack coat material was developed. To evaluate the newly developed asphalt emulsion, the bonding strength between the two layers of HMA was measured by applying a uniaxial tensile test and shear test. For the tests, a total of four different conditions were applied to the specimens, including the developed asphalt emulsion, latex modified asphalt emulsion, conventional asphalt emulsion, and non-tack coating. RESULTS AND CONCLUSIONS: Overall, the developed asphalt emulsion exhibits the best bonding strength behavior among all of the three types. Also, the two types of polymer-modified emulsions were found to be better for application for use as a tack coat than a conventional emulsion. Especially, at a high temperature ($50^{\circ}C$), the conventional asphalt emulsion no longer acts as a tack coating material. Therefore, the polymer-modified emulsion should be considered for application to tack coat construction during the summer.