• Title/Summary/Keyword: DTA

Search Result 958, Processing Time 0.024 seconds

A study on the environment of waste shell and its recycling method (패각의 부존환경 및 재활용에 관한 연구)

  • 이인곤
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.10 no.2
    • /
    • pp.159-165
    • /
    • 2000
  • This study was investigated the environment of waste shells such as oyster, cockle and paphia on southern shore in korea and established the recycling method to prevent the environmental pollution, etc. The waste shells were reclaimed at public shore illegally or leaved on the surroundings of shore. The origin mechanism, XRD and TG-DTA analyses were performed to effective recycling of waste shells, and the optimal recycling method was preparation of the calcium carbonate. In this work, calcium carbonate and lime fertilizer of granular shape were prepared using the waste shell.

  • PDF

Synthesis and characterization of layered basic zine p-toluenesulfonates (층상구조의 염기성 zinc p-toluenesulfonate의 합성 및 성질에 관한 연구)

  • 김형동;조영식;허영덕
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.8 no.4
    • /
    • pp.651-654
    • /
    • 1998
  • The layered basic zinc p-toluenesulfonates has been directly synthesized by the surface modification. The chemical formula of layered basic zinc p-toluenesulfonate is determined by CHNS and TG-DTA. From the X-ray diffraction data and the guest size, the orientation of the p-toluenesulfonate onto the zinc hydroxide layer is determined. The molecular plane of the p-toluenesulfonate lies perpendicular to the zinc hydroxide layers.

  • PDF

The orientations of ferroelastic domain in single Crystal, $CsPbCl_3$ ($CsPbCl_3$ 결정의 강탄성 domain의 orientations)

  • 신은정;정희태;김형국;정세영
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.7 no.1
    • /
    • pp.117-125
    • /
    • 1997
  • Ferroelastic $CsPbCl_3$ crystals were grown by the Czochralski method and Bridgman method. From XRD, DTA and the dielectric measurements, we investigated the structure and confirmed the phase transition temperatures of it. Using the polarizing microscope, we observed the ferroelastic domains and the temperature dependence of the domains. For the orientation states, we obtained the consistent result with the theoretical investigation by the crystallographical consideration. For Aizu species m3mF2/m(p) 12 orientation states are represented crystallographically.

  • PDF

Compositional homogeneity of potassium lithium niobate crystals grown by micro pulling down method ($\mu\textrm{m}$-PD법에 의해 육성한 KLN 단결정의 조성적 균일성)

  • Dae-Ho Yoon;Tsuguo Fukuda
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.4 no.4
    • /
    • pp.405-410
    • /
    • 1994
  • KLN crystals were grown with various melt compositions by $\mu\textrm{m}$-PD method. The composition of KLN crystals was determined by DTA and X-ray diffraction measurements. It can be obtained that KLN micro crystals have a nearly homogeneous composition along the growth axis because of the absence of convection in melt growth interface.

  • PDF

Properties of $TiO_2-V_2O_5$ Ceramics Prepared by Sol-Gel Method (솔젤법으로 제작한 $TiO_2-V_2O_5$ 세라믹스의 물성)

  • You, Do-Hyun
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.56 no.7
    • /
    • pp.1255-1260
    • /
    • 2007
  • [ $TiO_2-V_2O_5$ ] sol was prepared using sol-gel method. Sol changed to gel with hydrolysis and polymerization. DTA properties of gel powder had endothermic reaction due to evaporation of propanol about $80^{\circ}C$, had exothermic reaction due to combustion of propanol about $230^{\circ}C$ and had exothermic reaction due to combustion of alkyl group about $350^{\circ}C$. Crystalline properties of gel powder retained amorphous phase at $50^{\circ}C$, retained anatase phase from $400^{\circ}C\;to\;600^{\circ}C$ and had all rutile phase over $700^{\circ}C$ at 0.01mole $V_2O_5$ additive. The capacitance of thin films increased with increasing heat treatment temperature and thin films had best properties at $700^{\circ}C$. The capacitance of thin films increased a lot with decreasing measurement frequency.

Vibration Reduction for Electric Generator Panel of PKG (유도탄고속함 발전기 패널의 진동 저감)

  • Park, Mi-You;Kim, Yong-Wook
    • Proceedings of the KAIS Fall Conference
    • /
    • 2010.11b
    • /
    • pp.551-554
    • /
    • 2010
  • 유도탄고속함은 우리 해군의 최신예 함정으로서 디젤엔진 2기와 개스터빈 엔진 2기로 구성되어 최대 속력 40노트를 낼 수 있도록 구성되어 있다. 이를 위해 각각의 엔진에는 발전기가 배치되도록 구성되어 있는데, 이러한 발전기는 엔진 및 감속기어가 설치되어 있는 엔진룸에 배치되어 있어 커다란 진동에 그대로 노출이 되어 있는 상황이다. 따라서 이러한 진동의 저감을 위해 이중탄성마운트 등으로 발전기에 전달되는 진동을 저감하고자 하였으나 발전기의 패널에 전달되는 진동의 저감이 불충분하여 패널의 접지 불량이 수차례 발생하였다. 본 연구에서는 이러한 불량을 없애고자 유한요소법을 이용하여 발전기 패널의 위치를 변경하고 구조를 변경하였으며, 이를 통해 그 효과를 검증하였다.

  • PDF

A Dynamic TXOP Allocation Scheme for Providing QoS in IEEE 802.11e based Wireless Ad-hoc Networks (IEEE 802.11e 무선 애드혹 네트워크에서 QoS 지원을 위한 동적 TXOP 할당 기법)

  • Ju, Kwang-Sung;Chung, Kwang-Sue
    • Proceedings of the Korean Information Science Society Conference
    • /
    • 2011.06a
    • /
    • pp.373-376
    • /
    • 2011
  • 무선 멀티 홉 네트워크는 채널 상태의 불안정으로 인해 전송 지연, 패킷 손실 등의 발생이 빈번하며 홉 수가 증가할수록 이와 같은 품질 저하는 더욱 심각해진다. 무선 멀티 홉 네트워크에서 QoS를 보장하기 위해 IEEE 802.11e에서는 우선순위가 높은 노드에게 정해진 시간 동안 연속해서 보낼 수 있도록 TXOP(Transmission Opportunity) 파라미터 값을 정해놓고 있다. 하지만 IEEE 802.11e는 단일 홉 네트워크를 가정하여 설계되었기 때문에 멀티 홉 무선 환경에서 홉 수의 증가에 따른 지연 및 손실 증가를 고려하지 않는다. 본 논문에서는 멀티 홉 환경에서의 QoS 지원을 위한 DTA (Dynamic TXOP Allocation) 메커니즘을 제안하였다. DTA 메커니즘은 네트워크 상황을 고려한 동적 TXOP 할당 기법으로, 각 노드의 전송 큐 상태와 종단간 전송 지연 비율을 판별하여 이에 따른 QoS 지원을 위한 동적 TXOP를 할당한다. 이를 통해 불안정한 채널 상태 및 멀티 홉 환경에서 홉 수 증가에 따른 성능 감소를 개선할 수 있었다.

A Study on the Stimulation Transmit of Langmuir Films (Langmuir 막의 자극 전달에 관한 연구)

  • 전동규;이경섭;권영수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 1995.11a
    • /
    • pp.113-117
    • /
    • 1995
  • The mechanism of the displacement current generation for stimulation transmit observed in the present displacement current measurement and theoretically analysed. The orientational change of molecules in monolayers was discussed on the basis of the Maxwell-displacement-current obtained. Maxwell displacement current was generated from monolayers on a water surface by monolayerr compression, and it measuring technique has been applied to the study of monolayers of Dipalmitoylphosphatidyl choline (L-${\alpha}$-DPPC). Finally, We measured that differential thermal analysis(DTA) of sample. Displacement current was generated when the area per molecule about 180${\AA}$$^2$in low pressure, and it was generated when the area per molecule about 110${\AA}$$^2$in high pressure. A result of DTA was showed that temperature at 124.6$^{\circ}C$.

  • PDF

An Experimental study on the effect that sampling position of cement matrix influences Quantitative Analysis result (시멘트 경화체 시료의 채취 위치가 정량분석 결과에 미치는 영향에 관한 실험적 연구)

  • Jin, Joo-Ho;Lee, Sang-Hyun;Lee, Han-Seung
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2009.05a
    • /
    • pp.345-346
    • /
    • 2009
  • This research focused on large variation of the result of Ca(OH)$_2$ quantity by TG/DTA test or micro-pore size by MIP test. Assume that sample postion has influenced on experimental result, therefore, relationship between sampling position and the experimental result was studied As a result of the research, it is obvious that samples from inside(P-3) shows more Ca(OH)$_2$ and less porosity than samples from outside(P-1).

  • PDF