• Title/Summary/Keyword: Solid state processes

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Synthesis of Intermetallics and Nanocomposites by High-Energy Milling

  • Bernd F. Kieback;H. Kubsch;Alexander Bohm;M. Zumdick;Thomas Weissgaerber
    • Journal of Powder Materials
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    • v.9 no.6
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    • pp.416-421
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    • 2002
  • Elemental powders are used in high energy milling processes for the synthesis of new compounds. The low temperature solid state reactions during milling in inert gas atmosphere may result in intermetallic phases, carbides, nitrides or silicides with a nanocrystalline structure. To obtain dense materials from the powders a pressure assisted densification is necessary. On the other side the defect-rich microstructure can be used for activated sintering of elemental powder mixtures to obtain dense bodies by pressureless sintering. Results are discussed for nanocrystalline cermet systems and for the sintering of aluminides and silicides.

Multicomponent wide band gap oxide semiconductors for thin film transistors

  • Fortunato, E.;Barquinha, P.;Pereira, L.;Goncalves, G.;Martins, R.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.605-608
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    • 2006
  • The recent application of wide band gap oxide semiconductors to transparent thin film transistors (TTFTs) is making a fast and growing (r)evolution on the contemporary solid-state electronics. In this paper we present some of the recent results we have obtained using wide band gap oxide semiconductors, like indium zinc oxide, produced by rf sputtering at room temperature. The devices work in the enhancement mode and exhibit excellent saturation drain currents. On-off ratios above $10^6$ are achieved. The optical transmittance data in the visible range reveals average transmittance higher than 80 %, including the glass substrate. Channel mobilities are also quite respectable, with some devices presenting values around $25\;cm^2/Vs$, even without any annealing or other post deposition improvement processes. The high performances presented by these TTFTs associated to a high electron mobility, at least two orders of magnitude higher than that of conventional amorphous silicon TFTs and a low threshold voltage, opens new doors for applications in flexible, wearable, disposable portable electronics as well as battery-powered applications.

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Role of Fermentation in Improving Nutritional Quality of Soybean Meal - A Review

  • Mukherjee, Runni;Chakraborty, Runu;Dutta, Abhishek
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.11
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    • pp.1523-1529
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    • 2016
  • Soybean meal (SBM), a commonly used protein source for animal feed, contains anti-nutritional factors such as trypsin inhibitor, phytate, oligosaccharides among others, which limit its utilization. Microbial fermentation using bacteria or fungi has the capability to improve nutritional value of SBM by altering the native composition. Both submerged and solid state fermentation processes can be used for this purpose. Bacterial and fungal fermentations result in degradation of various anti-nutritional factors, an increase in amount of small-sized peptides and improved content of both essential and non-essential amino acids. However, the resulting fermented products vary in levels of nutritional components as the two species used for fermentation differ in their metabolic activities. Compared to SBM, feeding non-ruminants with fermented SBM has several beneficial effects including increased average daily gain, improved growth performance, better protein digestibility, decreased immunological reactivity and undesirable morphological changes like absence of granulated pinocytotic vacuoles.

Review of magnetic pulse welding

  • Kang, Bong-Yong
    • Journal of Welding and Joining
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    • v.33 no.1
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    • pp.7-13
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    • 2015
  • Magnetic pulse welding(MPW) is a solid state welding process that is accomplished by a magnetic pulse causing a high-velocity impact on two materials, resulting in a true metallurgical bond. One of the great advantages of MPW is that it is suitable for joining dissimilar metals. No heat affected zones are created because of the negligible heating and the clean surfaces formation that is a consequence of the jet and the metal is not degraded. Also, compared to other general welding processes, this process leads to only a low formation of brittle intermetallic compounds However, although this process has many advantages its application to industrial fields has so far been very low. Therefore, in this study we are presenting the principles, apparatus and application of MPW for application the industrial fields.

Theoretical and Practical Aspects of Pb-Sn Alloy Plating (Pb-Sn 합금도금의 이론 및 실제적 경향)

  • Paik, Young-Nam
    • Journal of the Korean institute of surface engineering
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    • v.12 no.3
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    • pp.161-166
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    • 1979
  • Theoretical and practical aspects are investigated for electrochemical behavious, plating processes and the structures of electrodeposit of Pb-Sn binary alloy plating through numerous literatures in this report. The anodic and cathodic electrode reaction mechanisms of Pb and Sn could co-deposit and make Pb-Sn alloy deposit from the results of cathode current density-cathode potential curves of Pb, Sn and Pb-Sn alloys in fluoborate solutions. The compositions of the best alloy plating solutions are obtained for the purpose of bearing, anticorrosion and solder plating. In general, the casting anodes of Pb-Sn alloys are used, but separated anodes of Pb and Sn pure metal are used in order to obtain the fine compositions of Pb-Sn alloy deposits. The electrodeposits of Pb-Sn alloy are in nonequilibrium state and saturated solid solutions. Thus, ${\beta}$-phase (Sn-phase) is precipitated by heat treatment. The texture and structure of the electrodeposit are associated with the surface energies of deposit lattice planes and with the cathode polarization. The electrodeposit of Pb-Sn alloy is shown as lamellar structure.

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Fluid-Structure Interaction Modeling and Simulation of CMP Process for Semiconductor Manufacturing

  • Sung, In-Ha;Yang, Woo-Yul;Kwark, Ha-Slomi;Yeo, Chang-Dong
    • Transactions of the Society of Information Storage Systems
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    • v.7 no.2
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    • pp.60-64
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    • 2011
  • Chemical mechanical planarization is one of the core processes in fabrication of semiconductors, which are increasingly used for information storage devices like solid state drives. For higher data capacity in storage devices, CMP process is required to show ultimate precision and accuracy. In this work, 2-dimensional finite element models were developed to investigate the effects of the slurry particle impact on microscratch generation and the phenomena generated at pad-particle-wafer contact interface. The results revealed that no plastic deformation and corresponding material removal could be generated by simple impact of slurry particles under real CMP conditions. From the results of finite element simulations, it could be concluded that the pad-particle mixture formed in CMP process would be one of major factors leading to microscratch generation.

Polarization Behavior of Li4Ti5O12 Negative Electrode for Lithiumion Batteries

  • Ryu, Ji-Heon
    • Journal of Electrochemical Science and Technology
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    • v.2 no.3
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    • pp.136-142
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    • 2011
  • $Li_4Ti_5O_{12}$ is prepared through a solid-state reaction between $Li_2CO_3$ and anatase $TiO_2$ for applications in lithium-ion batteries. The rate capability is measured and the electrode polarization is analyzed through the galvanostatic intermittent titration technique (GITT). The rate characteristics and electrode polarization are highly sensitive to the amount of carbon loading. Polarization of the $Li_4Ti_5O_{12}$ electrode continuously increases as the reaction proceeds in both the charge and discharge processes. This relation indicates that both electron conduction and lithium diffusion are significant factors in the polarization of the electrode. The transition metal (Cu, Ni, Fe) ion added during the synthesis of $Li_4Ti_5O_{12}$ for improving the electrical conductivity also greatly enhances the rate capability.

Limit of the maximum Signal Levels from other Radio Noise and interference of the Reciving Signal (외부잡음의 수신신호에 미치는 영향과 최악조건의 한계)

  • 김원후
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.5 no.1
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    • pp.34-39
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    • 1980
  • This paper discribes a effect of Radio signals in Noise and Interference for the Communication systems and Generation of diffusion Noise from the Solid state Devices, and in Jection it to the Radio Reciving systems for probability of Signal Detection. The error performance depends on level of the Noise spectral density by Random processes between average signal energy. This experimental result are given by the performance of the correlation receiver for detecting Completely known signals in additive white Gaussian Noise.

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A study of the output waveform of solid-state laser of multi-discharge method by various switching control (다수 스위칭 제어를 통한 Multi-Discharge방식의 고체레이저 출력파형 연구)

  • Kwak, S.Y.;Kim, S.G.;Hong, J.H.;Noh, K.K.;Kang, U.;Kim, H.J.
    • Proceedings of the KIEE Conference
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    • 2003.07c
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    • pp.1852-1854
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    • 2003
  • In manufacturing processes, various and suitable pulse shapes are required for the purpose of material processing. In order to make various pulse shapes with variable pulse length and high duty cycle, We have fabricated the power supply consisting 6 SCRs and the Pulse Forming Network(PFN) with the precise delay time control. So our control system has three switching circuits, 3 mesh PFN, and simmer circuit. In addition, we have designed and fabricated the PIC one-chip microprocessor(16F877) to control the delay time of sequential switching.

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Mechanochemical Approach for Oxide Reduction of Spent Nuclear Fuels for Pyroprocessing

  • Kim, Sung-Wook;Han, Seung Youb;Jang, Junhyuk;Jeon, Min Ku;Choi, Eun-Young
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.19 no.2
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    • pp.255-266
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    • 2021
  • Solid-state mechanochemical reduction combined with subsequent melting consolidation was suggested as a technical option for the oxide reduction in pyroprocessing. Ni ingot was produced from NiO as a starting material through this technique while Li metal was used as a reducing agent. To determine the technical feasibility of this approach for pyroprocessing, which handles spent nuclear fuels, thermodynamic calculations of the phase stabilities of various metal oxides of U and other fission elements were made when several alkaline and alkali-earth metals were used as reducing agents. This technique is expected to be beneficial, not only for oxide reduction but also for other unit processes involved in pyroprocessing.