• 제목/요약/키워드: synthesis techniques

검색결과 538건 처리시간 0.031초

New Processing of LED Phosphors

  • Toda, Kenji
    • Transactions on Electrical and Electronic Materials
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    • 제13권5호
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    • pp.225-228
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    • 2012
  • In order to synthesize LED phosphor materials, we have applied three novel synthesis techniques, "melt synthesis", "fluidized bed synthesis" and "vapor-solid hybrid synthesis", in contrast with the conventional solid state reaction technique. These synthesis techniques are also a general and powerful tool for rapid screening and improvements of new phosphor materials.

Synthesis and spectroscopic characterization of zinc ferrite nanoparticles

  • Arora, Shefali;Nandy, Subhajit;Latwal, Mamta;Pandey, Ganesh;Singh, Jitendra P.;Chae, Keun H.
    • Advances in nano research
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    • 제13권5호
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    • pp.437-451
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    • 2022
  • Synthesis approaches usually affect the physical and chemical properties of ferrites. This helps ferrite materials to design them for desired applications. Some of these methods are mechanical milling, ultrasonic method, micro-emulsion, co-precipitation, thermal decomposition, hydrothermal, microwave-assisted, sol-gel, etc. These methods are extensively reviewed by taking example of ZnFe2O4. These methods also affect the microstructure and local structure of ferrite which ultimately affect the physical and chemical properties of ferrites. Various spectroscopic techniques such as Raman spectroscopy, Fourier Transform Infrared spectroscopy, Ultra Violet-Visible spectroscopy, Mossbauer spectroscopy, extended x-ray absorption fine structure, and electron paramagnetic resonance are found helpful to reveal this information. Hence, the basic principle and the usefulness of these techniques to find out appropriate information in ZnFe2O4 nanoparticles is elaborated in this review.

Function-level module sharing techniques in high-level synthesis

  • Nishikawa, Hiroki;Shirane, Kenta;Nozaki, Ryohei;Taniguchi, Ittetsu;Tomiyama, Hiroyuki
    • ETRI Journal
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    • 제42권4호
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    • pp.527-533
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    • 2020
  • High-level synthesis (HLS), which automatically synthesizes a register-transfer level (RTL) circuit from a behavioral description written in a high-level programming language such as C/C++, is becoming a more popular technique for improving design productivity. In general, HLS tools often generate a circuit with a larger area than those of hand-designed ones. One reason for this issue is that HLS tools often generate multiple instances of the same module from a function. To eliminate such a redundancy in circuit area in HLS, HLS tools are capable of sharing modules. Function-level module sharing at a behavioral description written in a high-level programming language may promote function reuse to increase effectiveness and reduce circuit area. In this paper, we present two HLS techniques for module sharing at the function level.

A novel method for the synthesis of nano-magnetite particles

  • Syahmazgi, Maryam Ghodrati;Falamaki, Cavus;Lotfi, Abbas Sahebghadam
    • Advances in nano research
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    • 제2권2호
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    • pp.89-98
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    • 2014
  • A novel and simple method for the synthesis of nano-magnetite particles is disclosed. In the novel procedure, $Fe^{2+}$ is the only source of metal cation. Carboxymethylcellulose (CMC) is used as the structure directing agent. The phase analysis of the nano-particles was performed using XRD and electron diffraction techniques. Size and morphology analysis was performed using light scattering and TEM techniques. The effect of $NH_4OH$ solution (32 wt. %) at different CMC concentrations on the size distribution of the final magnetite powders is studied. An optimal base concentration exists for each CMC concentration leading to minimal agglomeration. There exists a minimum CMC concentration (0.0016 wt. %), lower than that no magnetite forms. It is shown that using the new method, it is possible to immobilize a lipase enzyme (Candida Rugosa) with immobilization efficiency larger than 98 % with a loading more than 3 times the reported value in the literature. The latter phenomenon is explained based on the agglomerate state of the nano-particles in the liquid phase.

On a Cepstral Pitch Alteration Technique for Prosody Control in the Speech Synthesis System with High Quality

  • Kim, Kyu-Hong;Baek, Seong-Joon;Bae, Myung-Jin
    • The Journal of the Acoustical Society of Korea
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    • 제18권1E호
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    • pp.32-36
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    • 1999
  • In the area of the speech synthesis techniques, the waveform coding methods maintain the intelligibility and naturalness of synthetic speech. In order to apply the waveform coding techniques to synthesis by rule, we must be able to alter the pitches of synthetic speech. In this paper, we propose a new pitch altering method that compensates phase distortion of the cepstral pitch alteration method with time scaling method in the time domain. This method can remove some spectrum distortion which is occurred in conjunction point between the waveforms. For performance test the spectrum distortion rate was used as objective criterion and the MOS(Mean Opinion Score) was used as subjective criterion. As a result, the spectrum distortion and MOS are obtained by 0.66% and 3.9, respectively.

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Don't Care를 이용한 논리합성에서의 BDD 최소화 방법 (BDD Minimization Using Don't Cares for Logic Synthesis)

  • 홍유포;박태근
    • 전자공학회논문지C
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    • 제36C권9호
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    • pp.20-27
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    • 1999
  • BDD는 논리합성 응용분야에서 많이 이용되는 데이터 구조체이다. 불완전하게 표시된 함수를 합성할 때, BDD의 크기를 최소화할 수 있으면 BDD의 구조를 따라 만들어지는 회로의 크기나 동작 속도를 향상시키는 데 큰 잇점이 있다. 본 논문에서는 논리합성을 위해 don't care를 이용하여 BDD를 최소화하기 위한 두 가지 알고리즘을 소개하고자 한다. 실험결과 제안된 방법은 기존 방법에 비해 수행시간의 희생 없이 더욱 작은 크기의 BDD을 얻을 수 있었다.

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능동소나 성능분석을 위한 신호 합성 모델 (Signal Synthesis Model for Active Sonar Performance Analysis)

  • 이균경
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1999년도 하계종합학술대회 논문집
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    • pp.683-686
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    • 1999
  • In this paper, we develop an active sonar signal synthesis model to analyze the detection performance of active sonar systems in a shallow water environment. Using this model, we synthesize the return signal of a bistatic sonar system at a typical operating frequency. This signal can be used to test proper active sonar signal processing techniques for real applications.

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CMS 방법에 의한 강교량의 동적모드해석 (Modal Analysis of Steel Box Bridge by Using the Component Mode Synthesis)

  • 조병완;박종칠;김영진
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1997년도 봄 학술발표회 논문집
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    • pp.177-184
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    • 1997
  • The Component Mode Synthesis Method for the -vibration analysis can be applied to the large-scaled structures, which have difficulty in modeling because of their intricate shapes and boundary conditions and need much time in computational calculations. This paper uses the Component Mode Synthesis Method to analyze the free vibration for the steel box bridge having the large number of D.O.F as an example of the large structural system. By comparing the CMS method to the other method (FEM), this paper proves the accuracy of the solution in techniques and the efficiency in time.

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Identification of Homoserine Lactone Derivatives Using the Methionine Functionalized Solid Phase Synthesis by Gas Chromatography/Mass Spectrometry

  • Moon, Hong-Sik
    • Archives of Pharmacal Research
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    • 제27권1호
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    • pp.25-30
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    • 2004
  • Combinatorial homoserine lactone mixtures and individual products were obtained from the methionine-functionalized resin in solid-phase synthesis. The four-step process consisting of a coupling step of an N-Fmoc-L-methionine, deprotection of N-Fmoc group, N-coupling with a carboxylic acid, and cleavage reaction through a polymer supported strategy is described. Gas chromatography-mass selective detector (GC-MSD) techniques provide the most powerful methods for identifying both the combinatorial mixtures and individual products.

부싱 요소를 이용한 평면 4 절 기구의 강체 유도 기구 합성 (Mechanism synthesis of Planar Four-bar Linkage for rigid body guidance by bushing elements)

  • 유홍희;홍정렬
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2014년도 추계학술대회 논문집
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    • pp.464-466
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    • 2014
  • The mechanism synthesis methods, graphical, analytical and computer-aided technique have been proposed for selecting and scaling mechanical system. According to developing computation tools, mechanism could be synthesized much faster and more correct than previous analytical ways by improved techniques. In this paper, the improved synthesis method is proposed to solve body guidance synthesis problem. To perform the mechanism synthesis for body guidance, a planar linkage is modeled as a set of free three bushings located in design space. The values of bushing stiffness and x, y position of bushings yielding a desired functional requirement related to input motion are found by using an optimization technique.

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