• Title/Summary/Keyword: DMT1

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Evaluation of Compressibility for Normally Consolidated South-east Coast Clay Using CPT and DMT (CPT와 DMT를 이용한 남동해안 정규압밀 점토의 압축성 추정)

  • Hong, Sung-Jin;Chae, Young-Ho;Lee, Moon-Joo;Lee, Woo-Jin
    • Journal of the Korean Geotechnical Society
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    • v.27 no.4
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    • pp.21-32
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    • 2011
  • A series of in-situ and laboratory tests were performed for the clayey soils of Busan area in order to develop the methods to evaluate the compressibility using CPT and DMT results. The laboratory tests show that the clayey layers of Busan areas are normally consolidated, and their compression indices are turned out to be 0.5~1.3. From the analysis of test results, correlation factors between the cone resistance and constrained modulus (${\alpha}_m$ and ${\alpha}_n$) are observed to decrease with increasing plasticity index, and the correlation factor between the dilatometer modulus and constrained modulus $(R_M)$ increases with $1/I_D$. Based on these relationships, the methods evaluating the constrained modulus from CPT and DMT results are suggested. It is shown that the prediction method by CPT underestimates the constrained modulus of improved ground, whereas the prediction method by DMT is suitable for evaluating the constrained modulus of improved and unimproved ground.

Metal Ion Transporters Identified in Recent Studies (최근에 밝혀진 금속이온 수송체)

  • 정재훈
    • Biomolecules & Therapeutics
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    • v.10 no.4
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    • pp.293-302
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    • 2002
  • The classical concept for iron uptake into mammalian cells has been the endocytosis of transferrin( $T_{f}$ )-bound F $e^{3+}$ via the $T_{f}$ - $T_{f}$ receptor cycle. In this case, we could not explain the uptake of F $e^{2+}$ ion and the export of iron from endosome. Studies on iron transport revealed that other transport system exists in epithelial cells of the intestine. One of non- $T_{f}$ -receptor-mediated transport systems is Nramp2/DMT1/DCT1 which transports M $n^{++}$, $Mg^{++}$, Z $n^{++}$, $Co^{++}$, N $i^{++}$ or C $u^{++}$ ion as well as F $e^{+2}$ ion. DMT1 was cloned from intestines of iron-deficient rats and shown to be a hydrogen ion-coupled iron transporter and a protein regulated by absorbed dietary iron. DMT1 is founded in other cells such as cortical and hippocampal glial cells as well as endothelial cells in duodenum. Two F $e^{3+}$ ion bound to transferrin( $T_{f}$ ) are taken up via the $T_{f}$ - $T_{f}$ receptor cycle in the intestinal epithelial cell. F $e^{3+}$ in endosome was converted to F $e^{2+}$ ion, and then exported to cytosol via DMT1. F $e^{2+}$ ion is taken up into cytosol via DMT1. Several other transporters such as FET, FRE, CCC2, AFT1, SMF, FTR, ZER, ZIP, ZnT and CTR have been reported recently and dysfunction of the transporters are related with diseases containing Wilson's disease, Menkes disease and hemochromatosis. Evidences from several studies strongly suggest that DMT1 is the major transporter of iron in the intestine and functions critically in transport of other metal ions.

Design and Performance Evaluation of Equalizer for the S-DMT Cable Modem (S-DMT 케이블 모뎀의 등화기 설계 및 성능평가)

  • Cho, Byung-Hak
    • Journal of Digital Contents Society
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    • v.7 no.2
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    • pp.109-115
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    • 2006
  • In this paper, we design and performance evaluate the equalizer for S-DMT table modem, which supports more channels and better quality symmetric mutimedia services over HFC network. We verified that both of the designed equalizers show good convergence characteristics and that the performance of the time domain equalizer is 1 dB better than that of the frequency domain equalizer overall range of Eb/No.

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Correlation of Constrained Modulus for Busan Clay using DMT (DMT를 이용한 부산점토의 변형계수 추정)

  • Hong, Sung-Jin;Cho, Yong-Soon;Jung, Sang-Jin;Lee, Woo-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.613-618
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    • 2008
  • Because the flat dilatometer (DMT) is operated in appropriate strain level, it has been known as an adoptable in-situ tool to evaluate the compressibility of soils compare with other in-situ test tools, such as SPT and CPT. This study is concerned about prediction method of constrained modulus by DMT, and a series of DMT and consolidation tests are performed at Busan new-port, Yangsan and Noksan test sites. By comparing DMT results with lab tests, the suitability of constrained modulus correlation, which is suggested by Marchetti, is investigated in Busan clay and new correlation is suggested. In lab test result, the compression indices ($C_c$) of Busan clay are turned out to be 0.4~0.12, and the constrained moduli are found out 0.5MPa~3MPa and these are increase with depth. The predicted constrained moduli using Marchetti's correlation are turned out 0.5MPa~4MPa, and these are bigger than measured constrained moduli by lab tests. By analyzing lab test and DMT results, it is shown that the correlation coefficient ($R_M=M/E_D$) has a linear relationship with (1/$I_D$) in Busan.

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Effects of Hepcidin Hormone on the Gene Expression of Ferroportin and Divalent Metal Transporter 1 in Caco-2 Cells and J774 Cells (Caco-2 소장세포와 J774 대식세포에서 Hepcidin 호르몬이 철분 수송체 Ferroportin과 Divalent Metal Transporter 1의 유전자 발현에 미치는 영향)

  • Chae, Sun-Ju;Chung, Ja-Yong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.6
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    • pp.721-728
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    • 2008
  • Hepcidin is a peptide hormone produced by the liver, of which secretion is closely related to iron status in the body. However, little is known about the molecular mechanism(s) by which this peptide regulates body iron homeostasis. The purpose of this study was to determine the effects of hepcidin treatment within the physiological concentration range on the expressions of two different iron transporter proteins-ferroportin (FPN) and divalent metal transporter 1 (DMT1). Differentiated Caco-2 intestinal cells and macrophage J774 cells were treated with either synthetic hepcidin or hepcidin-rich fraction separated from human urine at the concentration of 10 nM and 100 nM for 24 hours. Results show that hepcidin treatment in differentiated Caco-2 cells or in J774 cells did not change the level of either FPN mRNA or DMT1 mRNA. On the other hand, hepcidin treatment at the dose of 100 nM significantly decreased the FPN protein levels and DMT1 protein levels in differentiated Caco-2 cells. Similarly, urinary hepcidin treatment (10 nM & 100 nM) also significantly decreased the levels of FPN and DMT1 proteins in J774 macrophage cells. These results showed that hepcidin might play an important role in the regulation of iron homeostasis by lowering the protein levels of iron transporter FPN and DMT1 both in enterocytes and in macrophage cells.

Synthesis and Characterization of Copolyester Sizing Agents

  • Baik, Doo-Hyun;Kim, Gil-Lae
    • Fibers and Polymers
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    • v.2 no.1
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    • pp.148-151
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    • 2001
  • The effect of main chain structure of anion-containing copolyesters on the properties of copolyester sizing agents was investigated. The copolyesters were prepared by conventional two step polymerization technique from DMT, DMI, DMS, EG, and DEG. The copolyesters synthesized were characterized by atomic absorption spectroscopy, $^1$H-NMR Spectroscopy, GC, FTIR Spectroscopy, and DSC. The solubility decreased as the DMT content increased. The copolyesters having DMT:DMI = 1:1 showed the minimum viscosity. The effect of EG content on the solution stability was not clear and the samples having high DMI content showed better solution stability. The water resistance was best when only DMI and EG were used, while it was worst when DMT:DMI was 1:0.

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Synthesis of the Tetrazolium Derivatives for Ionic Liquid Rocket Fuel and a Study of Their Ignition Delay Time and Viscosity (이온성 액체로켓 연료용 테트라졸리윰 유도체의 합성 및 점화지연시간 및 점도에 대한 연구)

  • Lee, Hyun-Woong;Choi, Seong-Ho
    • Journal of the Korea Institute of Military Science and Technology
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    • v.25 no.3
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    • pp.285-291
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    • 2022
  • In order to use the liquid rocket fuel, 1,5-diamino-4-methyltetrazolium azide, [DMT]+[N3]- and 1,5-diamino-4-methyltetrazolium cyanide, [DMT]+[CN]- were synthesized and prepared the ionic liquid rocket fuel after dissolving the synthesized solid-type energetic chemicals in hydrazine, respectively. The thermal decomposition temperatures(Td) and densities(d) of the prepared ionic liquid rocket fuels were about 200 ℃ and above 1.0 g/cm3 respectively. The ignition delay times(Idt) of the ionic liqud rock fuels with [DMT]+[N3]- and [DMT]+[CN]- were in a range of 26.6 - 82.5 ms and the 44.0 - 98.5 ms, respectively. These results mean that the synthesized tetrazolium salts could be used as an ionic liquid rocket fuels. The viscosities of the ionic liqud rock fuels with [DMT]+[N3]- and [DMT]+[CN]-, which were dissolved in mixture solution of hydrazine/2-hydroxyethylhydrazine were to be 1.34 - 101 cP, and 1.29 - 80.5 cP, respectively. The synthesized ionic liquid rocket fuels in this study could be used as rocket fuel because the [Idt(100 ms or less), Td(150 ℃ or more), d(1.00 g/cm3 or more), and η(40.0~ 100 cP)] were achieved to satisfy the range of the used liquid rocket fuels.

Synthesis and Characterization of Poly(1,4-cyclohexanedimethylene/ethylene terephthalate) (Poly(1,4-cyclohexanedimethylene/ethylene terephthalate)의 합성 및 물성)

  • Cho, In-Ho;Rhee, Jong M.;Lee, Jong-Shin
    • Textile Coloration and Finishing
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    • v.3 no.3
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    • pp.23-28
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    • 1991
  • Poly(1, 4-cyclohexanedimethylene/ethylene terephthalate), PCET was prepared by condensing 1, 4-cyclohexanedimethanol(CHDM) and ethylene glycol with dimethylterephthalate(DMT), and some thermal properties of PCET were studied by DSC at a heating rate $20^{\circ}C$min. On increasing the CHDM content in PCET up to 20 mole%/DMT, the glass transition temperature(Tg) decreased a little and the crystallizability reduced sharply, and from 20 to 50 mole %/DMT the $T_g$ did not changed and the crystallization temperature was not detected. But on increasing the CHDM content above 70 mole %/DMT the TEX>$T_g$/ and the melting temperature increased.

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A Study on DMT Synthesis Using Crude TPA Sludge Generated from PET Alkaline Waste Water as Raw Materials (PET 감량폐약으로부터 발생되는 crude TPA sludge를 원료로 한 DMT 합성에 관한 연구)

  • Cho, Hwan;Kim, Jong Bo;Jeong, Hee Cheon;Jeon, Byung Dae
    • Textile Coloration and Finishing
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    • v.7 no.2
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    • pp.9-16
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    • 1995
  • When alkaline waste water of PET fabric is treated with sulfuric acid, undegradable material, crude TPA sludge is generated, so that treatment has a serious problem. The result of DMT synthesis using crude TPA sludge generated from PET alkaline waste water were as follows: 1. When crude TPA generated from alkaline waste water is reactioned with methanol under catalyst of sulfuric acid, pure DMT can be obtained. 2. In DMT synthesis from crude TPA, addition of copper sulfate can increase yield, and increasing the amount of sulfuric acid can shorten reaction time.

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The Kinetics of Transesterification between Dimethylterephthalate and 1,3-Propanediol (디메틸 테레프탈레이트와 1,3-프로판디올 사이의 에스테르교환반응에 관한 연구)

  • Na, Sang-Kuwon;Kong, Byeong-Gi;Choi, Chang-Yong;Kim, Jung-Gyu;Hong, Wan-Hae;Nah, Jae-Woon
    • Polymer(Korea)
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    • v.29 no.1
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    • pp.41-47
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    • 2005
  • The transesterification of dimethyl terephthalate (DMT) with 1,3-propanediol (PDO) was investigated in the presence of catalyst, titanium (IV) butoxide (TBO), at 175~190 $^{\circ}C$ . The degree of transesterification reaction was measured by the output of methanol which was distilled from the reactor. The amount of methanol increased as the reaction temperature, molar ratio and catalyst concentration increased. The observed overall rate of the transesterification was third order; first order with respect to DMT, PDO, and the concentration of catalyst, respectively. Using calculated rate constants, the activation energy for transesterification was 26.93 kcal/mole. The melting temperature of bis(2-hydroxytrimethyl) terephthalate (BHTMT) was 85.2$^{\circ}C$ and heat of fusion 141.3 J/g.