• Title/Summary/Keyword: MCM

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The study on the Design of Multichip Module (Multichip Module의 설계에 대한 연구)

  • 윤종남
    • Journal of the Microelectronics and Packaging Society
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    • v.2 no.2
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    • pp.57-64
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    • 1995
  • 본 연구의 목적은 MCM제품들을 개발하기 전단계로 MCM의 설계 및 MCM 설계에 필요한 CAD에 관한 현황을 조사 및 연구한 것이다.결과적으로 현재 MCM에 관하여 풀어 야 할 문제들을 도출하였으며 차후 이보고서가 MCM 및 HIC분야의 설계 CAD 선택을 연 구하는 Engineer들에게 좋은 자료로 활용될 것으로 판단된다.

Effect of E-box and E2F Binding Site on Transcriptional Activity in MCM Promoter (MCM promoter에서 E-box와 E2F 결합부위가 전사활성에 미치는 영향)

  • 권현주
    • Journal of Life Science
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    • v.14 no.5
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    • pp.732-740
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    • 2004
  • MCM proteins are essential for eukaryotic DNA replication, playing roles in the initiation and elongation of DNA replication. MCM proteins expression is much higher in malignant tissues than normal tissues. Several reports have indicated the usefulness of MCM proteins as markers of cancer cells in histopathological diagnosis. However, the cause of enhanced expression of MCM proteins in cancer cells remain to be clarified. The purpose of this study is to examine the relative transcriptional activities of human mcm gene promoters in cancer and normal cells. The minimal promoter region required for transcription of a luciferase reporter gene was contained an E-box and one E2F site. In addition, luciferase activities from mcm7 and mcm2 promoter/luciferase gene reporter constructs were significantly increased in cancer cells at 8 times compared with normal cells. E-box and E2F binding site in the promoter of mcm genes are responsible for different mechanism of transcription regulation on the cellular environment.

CO2 Removal using MEA (monoethanolamine) Impregnated Mesoporous Materials (MEA (monoethanolamine) 함침 메조포러스 물질을 이용한 CO2 회수)

  • Park, Ye-Won;Baek, Il-Hyun;Park, Sang-Do;Lee, Jae-Wook;Park, So-Jin
    • Korean Chemical Engineering Research
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    • v.45 no.6
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    • pp.573-581
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    • 2007
  • The present study deals with removal of $CO_2$ using various mesoporous materials impregnated with MEA (monoethanolamine). The mesoporous materials such as MCM-41, MCM-48 and SBA-15 were synthesised and then impregnated with 30, 50 and 70 wt% of MEA, respectively. XRD, FT-IR and SEM were used to evaluate the characterization of those. From the adsorption/desorption experiments for various materials, the adsorption capacity of these materials were found in the order of MCM-41> MCM-48> SBA-15. MCM-41 impregnated with 50 wt% of MEA showed the maximum adsorption capacity of $57.1mg-CO_2/gr-sorbent$ at $40^{\circ}C$. It is nearly 8 times higher than MCM-41 without impregnation of MEA. In the multiple cycle test of 20 times, MCM-41 impregnated with 50 wt% of MEA showed a constant adsorption capacity.

The Replicon Initiation Burst Released by Reoxygenation of Hypoxic T24 Cells is Accompanied by Changes of MCM2 and Cdc7

  • Martin, Leenus
    • BMB Reports
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    • v.40 no.5
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    • pp.805-813
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    • 2007
  • Although MCM2 is obviously important for the initiation of eukaryotic DNA replication, its role in $O_2$ dependent regulation of replicon initiation is poorly understood. In this report, I analysed the changes of MCM2 during the transition from hypoxically suppressed replicon initiation to the burst of initiation triggered by reoxygenation in T24 cells. A high level of chromatin bound and nucleosolic MCM2 was found under the hypoxic replicon arrest. In contrast low cytosolic MCM2 was noticed. Recovery of $O_2$ induced phosphorylation and diminution of chromatin bound MCM2, whereas cytosolic MCM2 increased. The level of chromatin bound Cdc7 did not change significantly upon reoxygenation. However, after reoxygenation, significant phosphorylation of Cdc7 and an increase of coimmunoprecipitation with its substrate (MCM2) were observed. This provides a hint that reoxygenation may promote the kinase activity of Cdc7. These changes might be the critical factors in $O_2$ dependent regulation of replicon initiation. Moreover, phosphorylation of Cdc7 by Cdk2 can be observed in vitro, but seems to fail to regulate the level of chromatin bound Cdc7 as well as the changes of MCM2 in response to reoxygenation of hypoxically suppressed cells.

Performance Analysis of 800Gb/s ATM Switching MCM (800Gb/s ATM 스위칭 MCM의 성능분석)

  • Jung, Un-Suk;Kim, Hoon;Park, Kwang-Chae
    • Proceedings of the IEEK Conference
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    • 2001.06a
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    • pp.155-158
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    • 2001
  • A 640Gb/s high-speed ATM switching system that is based on the technologies of advanced MCM, 0.25um CMOS and optical WDM interconnection is fabricated for future N-ISDN services. A 40 layer, 160mm$\times$114mm ceramic MCM realizes the basic ATM switch module with 80Gbps throughput. The basic unit ATM switch module with 80Gb/s throughput. The basic unit ATM switch MCM consists of in 8 chip advanced 0.25um CMOS VLSI and 32 chip I/O Bipolar VLSIs. The MCM employs an 40 layer, very thin layer ceramic MCM and a uniquely structured closed loop type liquid colling system is adopted to cope with the MCM's high-power dissipation of 230w. The MCM is Mounted on a 32cm$\times$50cm mother board. A three stage ATM switch is realized by optical WDM interconnection between the high-performance MCM.

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Self-assembly directed synthesis of tubular conducting polymer inside the channels of MCM-41

  • Showkat, Ali Md.;Lee, Kwang-Pill;Gopalan, Anantha Iyengar;Reddy, K. Raghava;Kim, Sang-Ho;Choi, Seong-Ho
    • Analytical Science and Technology
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    • v.19 no.3
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    • pp.211-217
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    • 2006
  • Diphenyl amine (DPA) was polymerized inside the channels of the mesoporous silica (MCM-41). MCM-41 (C) and MCM-41 (D) were prepared with cetyltrimethyl ammonium bromide (CTAB) and dodecyltrimethyl ammonium bromide (DTAB), respectively and used as hosts. Initially, the self assembly of DPA inside the pores of MCM-41 was made in ${\beta}$-naphthalene sulfonic acid (NSA) medium and subsequently poly (diphenylamine), PDPA was formed by oxidative polymerization. $N_2$ adsorption-desorption measurements of PDPA loaded MCM-41 (C) and MCM-41 (D) show variations in pore volume and surface area between them. A tubular form of poly (diphenylamine), PDPA was envisaged to form in the pores of MCM-41 and supported by high resolution transmission microscopy. The presence of PDPA inside the channel of MCM-41 was further confirmed by FTIR spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction.

Synthesis, Characterizations, and Applications of Metal-Ions Incorporated High Quality MCM-41 Catalysts (고품질 금속 이온 첨가 MCM-41 분자체 촉매의 제법, 특성화 및 응용 반응)

  • Lim, Steven S.;Haller, Gary L.
    • Korean Chemical Engineering Research
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    • v.51 no.4
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    • pp.443-454
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    • 2013
  • Various metal ions (transition and base metals) incorporated MCM-41 catalysts can be synthesized using colloidal and soluble silica with non-sodium involved process. Transition metal ion-typically $V^{5+}$, $Co^{2+}$, and $Ni^{2+}$-incorporated MCM-41 catalysts were synthesized by isomorphous substitution of Si ions in the framework. Each incorporated metal ion created a single species in the silica framework, single-site solid catalyst, showing a substantial stability in reduction and catalytic activity. Radius of pore curvature effect was investigated with Co-MCM-41 by temperature programmed reduction (TPR). The size of metallic Co clusters, sub-nanometer, could be controlled by a proper reduction treatment of Co-MCM-41 having different pore size and the initial pH adjustment of the Co-MCM-41 synthesis solution. These small metallic clusters showed a high stability under a harsh reaction condition without serious migration, resulting from a direct anchoring of small metallic clusters to the partially or unreduced metal ions on the surface. After a complete reduction, partial occlusion of the metallic cluster surface by amorphous silica stabilized the particles against aggregations. As a probe reaction of particle size sensitivity, carbon single wall nanotubes (SWNT) were synthesized using Co-MCM-41. A metallic cluster stability test was performed by CO methanation using Co- and Ni-MCM-41. Methanol and methane partial oxidations were carried out with V-MCM-41, and the radius of pore curvature effect on the catalytic activity was investigated.

Knoevenagel Condensation Reaction Using Amine-functionalized MCM-41 Base Catalysts (아민고정화 MCM-41 염기촉매를 이용한 Knoevenagel 축합반응)

  • Choi, Jung-Sik;Ahn, Wha-Seung
    • Korean Chemical Engineering Research
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    • v.44 no.4
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    • pp.417-423
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    • 2006
  • A series of amine functionalized MCM-41 catalysts were prepared by aminopropyltrimethoxysilane grafting and their catalytic performance in Knoevenagel reaction of selected substrates was investigated. Water resistant and catalytically active amine grafted MCM-41 was prepared by post-synthetic silylation using methyltrimethoxysilane ; hydrogen bonding of the water molecules formed during the condensation reaction to the active N group was suppressed, which led to high TON of the reaction. Amine functionalized MCM-41 prepared by coating method produced high conversion, but the TON of the catalyst was much lower than that of the amine grafted MCM-41; pore volume of the functionalized MCM-41 decreased substantially and large portion of the immobilized amine is believed to be hydrogen bonded to each other, which can result in decrease in the basicity of the N group. A secondary amine group was prepared by room temperature condensation between aminopropylsilane and chloropropylsilane, and the MCM-41 grafted with the secondary amine group demonstrated the highest catalytic activity among the catalysts prepared.

Embedded Inductors in MCM-D for RF Appliction (RF용 MCM-D 기판 내장형 인덕터)

  • 주철원;박성수;백규하;이희태;김성진;송민규
    • Journal of the Microelectronics and Packaging Society
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    • v.7 no.3
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    • pp.31-36
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    • 2000
  • We developed embedded inductors in MCM-D substrate for RF applications. The increasing demand for high density packaging was the driving forces to the development of MCM-D technology. Most of these development efforts have been focused on high performance digital circuits. However, recently there is a great need fur mixed mode circuits with a combination of digital, analog and microwave devices. Mixed mode modules often have a large number of passive components that are connected to a small number of active devices. Integration of passive components into the high density MCM substrate becomes desirable to further reduce cost, size, and weight of electronic systems while improving their performance and reliability. The proposed MCM-D substrate was based on Cu/photosensitive BCB multilayer and Ti/Cu is used to form the interconnect layer. Seed metal was formed with 1000 $\AA$ Ti/3000 $\AA$ Cu by sputtering method and main metal was formed with 3 $\mu\textrm{m}$ Cu by electrical plating method. The multi-turn sprial inductors were designed in coplanar fashion. This paper describe the manufacturing process of integrated inductors in MCM-D substrate and the results of electrical performance test.

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Preparation of Supported CTAB/MCM-41 and CTAB-Nafion/MCM-41 Mesoporous Molecular Sieve and Their Use in the Brominating Reaction (담지된 CTAB/MCM-41 and CTAB-Nafion/MCM-41 메조다공성 분자체의 제조 및 브롬화 반응에 사용)

  • Hu, Guoqin;Li, Hua;Liu, Juan;Zhu, Jiang
    • Journal of the Korean Chemical Society
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    • v.55 no.4
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    • pp.691-696
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    • 2011
  • CTAB or CTAB-Nafion catalyst were successfully supported on siliceous hollow tubular MCM-41 which synthesized by hydrothermal method using CTAB as a single template or CTAB and Nafion-Na as mixed templates. The properties of two kinds of catalysts were characterized with XRD, SEM and adsorption and desorption isotherms of nitrogen and pore diameter distribution, respectively. Then they were applied to catalyze brominating reaction of 1,7-heptanediol, moreover the rate of brominating reaction with different catalysts was compared. The results showed that catalytic activities of CTAB/MCM-41 and CTAB-Nafion/MCM-41 are better than CTAB, and that of CTAB-Nafion/MCM-41 is the best because of its phase-transfer and strong acidity function. The two kinds of catalysts can be separated from the reactive products and recycled.