• Title/Summary/Keyword: Unit cell analysis

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Electrochemical properties and Estimation of $LiMnO_{2}$ Active Material Synthesis for Secondary Batteries (2차 전지용 $LiMnO_{2}$ 활물질 합성의 전기화학적 특성과 평가)

  • Wee, Sung-Dong;Gu, Hal-Bon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.210-215
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    • 2002
  • This thesis is contents on the crystal grown by the solide phase method at $925^{\circ}C$ with orthorhombic structure that $LiMnO_{2}$ active material synthesised with precurse $Mn_{2}O_{3}$ and $LiOH.H_{2}O$ material to get three voltage level. The porosity analysis of the grown crystal in secondary batteries $LiMnO_{2}$ thin film is $1.323E+02\AA$ of the average pore diameter of powder particles and its structure to be taken the pore diameter was prepared. Adding voltage area to get properties of charge and discharge of which experiment result of $LiMnO_{2}$ thin film area 2.2V~4.3V, current and scan speed were 0.1mAh/g and $0.2mV/cm^{2}$ respectively, and properties of the charge and discharge to be got optimum experiment condition parameter and density rate of Li for analyze that unit discharge capacity with metal properties is 87mAh/g was 96.9[ppm] at 670.784[nm] wavelength, and density rate of Mn analyzed 837[ppm] at 257.610[nm]. It can be estimated the quality of thin film that wrong cell reject from the bottle of electrolyte. The results of SEM and XRD were the same that of original researchers.

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A Study on Actual Condition Analysis of Solar Thermal System Demonstrative Enterprise in the J City (J시 태양열 시범사업의 실태조사.분석에 관한 연구)

  • Yoo, Dong-Chul;Lee, Doo-Ho;Lee, Eung-Jik
    • 한국태양에너지학회:학술대회논문집
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    • 2011.04a
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    • pp.80-85
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    • 2011
  • As the instability of oil prices rose because of the situation in Libya, oil prices worldwide recorded the highest level due to the interference in supply. And so, in the 21st century, increasing efforts are being made to use clean new renewable energy centered on solar energy in accommodation of the cycle of nature instead of being reliant on the oil exporting nations. In order to reduce city energy internationally, the implementation of a low carbon city under the combined cooperation of industrial. construction, new renewable energy and transportation sectors with continuous development centered on low carbon green urban planning is now becoming established as the paradigm of the times. Recently, the government has begun carrying out the One Million Green Home Project, which is a project where the government with the goal of providing one million renewable energy homes by 2020 gives renewable energy subsidization for a partial amount of the standard unit price of installation when solar ray, solar heat, geothermal heat, small wind power or fuel cell energy is used. Thus, through this thesis which studies the state of and surveys the green village at Shingok-ri Songhak-myun Jaecheon-shi, it is the desire that the One Million Green Homes Project will be more efficiently developed and plans for improvement formed so that a high level of satisfaction in the product will be provided.

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Characterization of Hexagonal Tungsten Bronze CsxWO3 Nanoparticles and Their Thin Films Prepared by Chemical Coprecipitation and Wet-Coating Methods

  • Kwak, Jun Young;Hwang, Tai Kyung;Jung, Young Hee;Park, Juyun;Kang, Yong-Cheol;Kim, Yeong Il
    • Journal of the Korean Chemical Society
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    • v.62 no.2
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    • pp.118-123
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    • 2018
  • The hexagonal tungsten bronze $Cs_xWO_3$ nanoparticle was synthesized by a chemical coprecipitation method of ammonium tungstate and $Cs_2CO_3$ in acidic condition. This synthetic method for cesium tungsten bronze is reported for the first time as far as we know. The synthesized $Cs_xWO_3$ as precipitated showed a weak crystallinity of hexagonal unit cell with a crystallite size of about 4 nm without annealing. When the synthesized $Cs_xWO_3$ was annealed in $N_2$ atmosphere, the crystallinity and crystallite size systematically increased maintaining the typical hexagonal tungsten bronze structure as the annealing temperature increased. The analyzed Cs content in the bronze was about 0.3 vs W, which is very close to the theoretical maximum value, 1/3 in cesium tungsten bronze. According to XPS analysis, the reduced tungsten ions existed as both the forms of $W^{5+}$ and $W^{4+}$ and the contents systematically increased as the annealing temperature increased up to $800^{\circ}C$. The $Cs_xWO_3$ thin films on PET substrate were also prepared by a wet-coating method using the ball-milled solution of the annealed $Cs_xWO_3$ nanoparticles at various temperatures. The near-infrared shielding property of these thin films increased systematically as the annealing temperature increased up to $800^{\circ}C$ as expected with the increased contents of reduced tungsten ions.

The Crystallograpic and Magnetic Properties of EuFeO3 Doped with in ions (In 이온을 첨가한 $EuFeO_{3}$의 결정구조 및 자기적 성질)

  • 김정기;서정철;한은주
    • Journal of the Korean Magnetics Society
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    • v.4 no.4
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    • pp.335-339
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    • 1994
  • The crystallograpic and magnetic properties of $Eu(Fe_{1-x}In_{x})O_{3}$ (x=0, 0.03과 0.05) have been studied by the methods of X-ray diffraction, $M\"{o}ssbauer$ spectroscopy, and magnetic hysteresis measurement at room temperature. The X-ray results show that the samples have a crystal structure of orthorhombic and unit cell volume of the crystal with the exception of the sample of x=0 increases as increasing the In concentration. In the analysis assuming two sets of six-line of $M\"{o}ssbauer$ spectra, it is found that the magnetic hyperfine field in each of sets decreases increasing x. The linewidth of the absorption lines for the samples increased as increasing x. This implies that the data involve a sum of several hyperfine patterns which have intensity being proportional to $_{n}P_{z}(x)$, the probability of an environment with z such Fe neighbors. The magnetic hysteresis curves show decrease of $M_{s}$ and increase of $H_{c}$ of the samples with increasing x.

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DISTRIBUTION OF VIRUSES IN WATER ENVIRONMENT

  • Lee Seung-Hoon;Cho Hong Baek;Kim Sang-Jong
    • Proceedings of the Microbiological Society of Korea Conference
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    • 2000.05a
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    • pp.94-101
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    • 2000
  • We investigated the viral contamination of water environment including tap water in Korea. River water used for source water was analyzed about monthly between 1997 and 1999 over a period 26 months. A total of 22 tap water samples were collected in 10 sites in 2 urban areas between 1997 and 1998 over a 11 months. All samples were examined for infectious enteroviruses and adenoviruses by a cell culture technique followed by PCR amplification. To identify the recovered viruses from tap water, sequence analysis of PCR products was performed. Infectious viral particles were detected in river water all year round, ranging from 0.93 to 17.3 Most Probable Number of Infectious Unit (MPNIU) /100L. Tap water samples also contained infectious viral particles. The frequency of enteroviruses and adenoviruses in tap water were $50.0\%$ (11/22) and $36.7\%$ (8/22), respectively. Both enteroviruses and adenoviruses were detected in five tap water samples $(22.7\%)$. The level of viral contamination in tap water was quite high, ranging from 0.2 to 2.9 MPNIU/100L, far above the recommended virus level in drinking water set by the U.S. EPA. Poliovirus type 1 derived from vaccine was frequently detected and the remainder comprised coxsackievirus B type or echovirus type 6, which were causative agents of aseptic meningitis in Korea in 1997 and 1998, respectively. Several types of adenovirus were detected in tap water samples and some water samples were found to contain adenoviruses which were closely related to enteric adenovirus type 40 and 41. This stusy shows that surface water and tap water in Korea may be exposed to the risk of viral contamination, especially from recently recognized viruses and this constitutes a potential public health hazard.

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Design of Compact Isolation Network of Marchand Balun Using CRLH Transmission Line (CRLH 전송선을 이용한 Marchand 발룬의 소형 격리 회로 설계)

  • Moon, Byeong-Taek;Han, Jung-Hoon;Myung, Noh-Hoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.9
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    • pp.1042-1047
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    • 2012
  • In order to obtain balanced ports matching and isolation between balanced ports of a Marchand balun, a compact isolation network is proposed. The proposed compact isolation network is designed using composite right/left-hand (CRLH) transmission line and compact phase inverter using CRLH transmission line unit cell. Also, design method and analysis of proposed isolation network are presented. The sizes of the proposed isolation networks are significantly reduced to $0.11{\lambda}_g$ and $0.07{\lambda}_g$ compared with the conventional isolation network of $0.5{\lambda}_g$. The Marchand balun is operated at 2.45 GHz and is demonstrated through excellent experimental results.

Isolation and Characterization of a Crude oil-Degrading Strain, Nocardia sp. H 17-1 (원유 분해균주 Nocardis sp. Hl7-1의 분리 및 특성)

  • 이창호;권기석
    • KSBB Journal
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    • v.11 no.6
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    • pp.654-662
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    • 1996
  • Bacterial strains which degrade crude oil were isolated by liquid culture from oil-spilled soil, and four isolates were selected among them. The strain Hl7-1 was finally selected after testing emulsifying activity and oil conversion rate. The strain Hl7-1 was identified as a Nocardia sp. based on the test for morphological, biochemical and physiological characteristics. It appears to be highly specialized for growth on crude oil in minimal salts medium since it showed preference for oil or degradation products as substrates for growth. It was found that it could grow on at least fifteen different hydrocarbons. The optimum cultural and environmental conditions were seeked. Cell growth and emulsification activity as a function of time were also determined. Crude oil degradation and the reduction of product peak was identified by the analysis of remnant oil by gas chromatography after 3 days of cultivation. Approximately 83% of oil were converted into a form no longer extractable by organic solvents.

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The Crystal and Molecular Structure of Piperidinothiosemicarbazide (Piperidinothiosemicarbazide의 結晶 및 分子構造)

  • Koo, Chung Hoe;Kim Hoon Sup;Chang Chong Hwan
    • Journal of the Korean Chemical Society
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    • v.19 no.2
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    • pp.85-91
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    • 1975
  • The crystal structure of piperidinothiosemicarbazide, $C_6H_{13}N_3S$, has been determined by single crystal X-ray analysis. The space group is P21/c with four molecules in the unit cell of dimensions $a=14.68{\pm}0.04,\;b=4.59{\pm}0.02,\;c=12.92{\pm}0.04{\AA}\;and\;{\beta}=109.4{\pm}0.2^{\circ}$. Three-dimensional photographic intensities were estimated visually. The structure has been solved by an interpretation of a Patterson synthesis and refined by block-diagonal least-squares methods to give a final R value of 0.14 for 378 observed independent reflections. There are two independent hydrogen bonds in the structure. One of them is of the type N-H${\ldots}$S with the length 3.28 and $3.39{\AA}$, and another is of the type N-H${\ldots}$N with the length $3.03{\AA}$. Apart from the hydrogen bonding system the molecules are held together in the crystal by van der Waals forces.

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Calculation of Power Distributions on Uranium- and Plutonium-Loaded Cores Moderated by Light Water (우라늄 및 플루토늄 장전 노심에서의 출력 분포 계산)

  • Sang Keun Lee;Kap Suk Moon;Jong-Hwa Jang;Ji Bok Lee;Chang Kun Lee
    • Nuclear Engineering and Technology
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    • v.15 no.4
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    • pp.267-279
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    • 1983
  • An analytical system has been established for scrutinizing both uranium- and plutonium-fueled lattices moderated by light water. This system consists of two primary codes. One is a unit cell program called KICC, which has theoretical foundation on the models of GAM and THERMOS incorporated with appropriate approximate treatments for various phenomena, whereas the other is a multi-dimensional diffusion-depletion program entitled KIDD. The adequacy of this system is verified by performing extensive benchmark calculations on a variety of critical experiments. The average value of effective multiplication factors for the selected nineteen UO$_2$ critical experiments of heterogeneous lattice structure is calculated to be 1.0006 with a standard deviation of 0.0039. Power distributions have also been calculated for some critical experiments fueled with both uranium and plutonium of varying concentrations. The maximum percentage difference between the measured and calculated power distributions appears to be less than 5%. This result, together with the previously reported result, illustrates that the KICC/KIDD system is a very effective tool for the analysis of a light water reactor core.

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Characteristics of Ammonia Removal in Biofilters Inoculated with Earthworm Cast. (분변토를 접종한 바이오필터의 암모니아 제거 특성)

  • 류희욱;한희동;조경숙
    • Microbiology and Biotechnology Letters
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    • v.30 no.1
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    • pp.73-78
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    • 2002
  • Four inorganic packing materials (zeocarbon, porous celite, porous glass, zeolite) and a earthworm cast were compared with regard to the removal of ammonia in a biofilter inoculated with earthworm cast. Physical adsorption of ammonia on packing materials were negligible except zeocarbon (23.5 g-$NH_3$/kg), and cell immobilization capacity have similar values irrespective of packing materials. Pressure drops of the packed bed were in order of earthworm cast zeocarbon zeolite porous glass porous. The maximum elimination capacity ($g-Nkg^{-1}$ $d^{-1}$ ) of ammonia, which were based on a unit volume of packing material, were in order of zeocarbon (526) earthworm cast (220) porous celite (93) > zeolite (68) > porous glass (53). By using kinetic analysis, the maximum removal rates ($V_{m}$ ) and the saturation constant ($K_{s}$ ) for ammonia were determined, and zeocarbon showed superior performance among the five materials.