• Title/Summary/Keyword: Matrix laboratory

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Biofilm formation on denture base resin including ZnO, CaO, and TiO2 nanoparticles

  • Anwander, Melissa;Rosentritt, Martin;Schneider-Feyrer, Sibylle;Hahnel, Sebastian
    • The Journal of Advanced Prosthodontics
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    • v.9 no.6
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    • pp.482-485
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    • 2017
  • PURPOSE. This laboratory study aimed to investigate the effect of doping an acrylic denture base resin material with nanoparticles of ZnO, CaO, and $TiO_2$ on biofilm formation. MATERIALS AND METHODS. Standardized specimens of a commercially available cold-curing acrylic denture base resin material were doped with 0.1, 0.2, 0.4, or 0.8 wt% commercially available ZnO, CaO, and $TiO_2$ nanopowder. Energy dispersive X-ray spectroscopy (EDX) was used to identify the availability of the nanoparticles on the surface of the modified specimens. Surface roughness was determined by employing a profilometric approach; biofilm formation was simulated using a monospecies Candida albicans biofilm model and a multispecies biofilm model including C. albicans, Actinomyces naeslundii, and Streptococcus gordonii. Relative viable biomass was determined after 20 hours and 44 hours using a MTT-based approach. RESULTS. No statistically significant disparities were identified among the various materials regarding surface roughness and relative viable biomass. CONCLUSION. The results indicate that doping denture base resin materials with commercially available ZnO, CaO, or $TiO_2$ nanopowders do not inhibit biofilm formation on their surface. Further studies might address the impact of varying particle sizes as well as increasing the fraction of nanoparticles mixed into the acrylic resin matrix.

Adaptive Interference Cancellation Method in Wireless Repeater System (무선 중계 시스템에서의 적응 간섭 제거 방식)

  • Han, Yong-Sik
    • The Journal of the Korea institute of electronic communication sciences
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    • v.11 no.5
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    • pp.459-464
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    • 2016
  • The mobile communication service is widely used and the repeaters is rapidly increasing because of the extending service areas. we propose a new Signed CMA(: Constant Modulus Algorithm) algorithm for ICS(: Interference Cancellation System) as a larger service area of mobile communication service. The proposed Signed CMA algorithm improved performances by adjusting step size values. We showed that the proposed algorithm could improve the Mean Square Error(: MSE) performance of Signed CMA. MATLAB(: Matrix Laboratory) is employed to analyze the proposed algorithm and to compare it with the experimental results. At the convergence of 1000 iteration state, the MSE(: Mean Square Error) performance of the proposed Signed CMA algorithm with step size of 0.0065 is about 5 dB better than the conventional CMA algorithm.

Molecular characterization of a lectin, BPL-4, from the marine green alga Bryopsis plumosa (Chlorophyta)

  • Han, Jong-Won;Yoon, Kang-Sup;Jung, Min-Gui;Chah, Kyong-Hwa;Kim, Gwang-Hoon
    • ALGAE
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    • v.27 no.1
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    • pp.55-62
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    • 2012
  • A novel lectin specific to N-acetyl-D-galactosamine as well as N-acetyl-D-glucosamine was isolated from Bryopsis plumosa and named as BPL-4. Sodium dodecyl sulfate polyacrylamide gel electrophorese (SDS-PAGE) and matrix-assisted laser desorption / ionization-time of flight (MALDI-TOF) mass spectrometry data showed that this lectin was a monomeric protein with molecular weight 12.9 kDa. The N-terminal amino acid sequences of the lectin were determined by Edman degradation and the full cDNA sequence encoding this lectin was obtained using the degenerate primers designed from the amino acid sequence. The size of the cDNA was 414 bp containing single open reading frame (ORF) encoding the lectin precursor. The homology analysis showed that this lectin might belong to H lectin group. BPL-4 showed high sequence similarity (60.6%) to BPL-3, which is a previously reported lectin from the same species. The comparative analysis on the lectin's primary structure showed two conserved domains including one possible active domain of H lectin group.

Theoretical formulation of double scalar damage variables

  • Xue, Xinhua;Zhang, Wohua
    • Computers and Concrete
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    • v.19 no.5
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    • pp.501-507
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    • 2017
  • The predictive utility of a damage model depends heavily on its particular choice of a damage variable, which serves as a macroscopic approximation in describing the underlying micromechanical processes of microdefects. In the case of spatially perfectly randomly distributed microcracks or microvoids in all directions, isotropic damage model is an appropriate choice, and scalar damage variables were widely used for isotropic or one-dimensional phenomenological damage models. The simplicity of a scalar damage representation is indeed very attractive. However, a scalar damage model is of somewhat limited use in practice. In order to entirely characterize the isotropic damage behaviors of damaged materials in multidimensional space, a system theory of isotropic double scalar damage variables, including the expressions of specific damage energy release rate, the coupled constitutive equations corresponding to damage, the conditions of admissibility for two scalar damage effective tensors within the framework of the thermodynamics of irreversible processes, was provided and analyzed in this study. Compared with the former studies, the theoretical formulations of double scalar damage variables in this study are given in the form of matrix, which has many features such as simpleness, directness, convenience and programmable characteristics. It is worth mentioning that the above-mentioned theoretical formulations are only logically reasonable. Owing to the limitations of time, conditions, funds, etc. they should be subject to multifaceted experiments before their innovative significance can be fully verified. The current level of research can be regarded as an exploratory attempt in this field.

Neonatal Onset Isovaleric Acidemia with Novel Mutation (아이소발레린산혈증 신생아에서 발견된 새로운 돌연변이)

  • Kim, Young Han;Bae, Eun Ju;Park, Hyung-Doo;Lee, Hong Jin
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.16 no.1
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    • pp.42-46
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    • 2016
  • Isovaleric acidemia is autosomal-recessively inherited and an inborn error of metabolism caused by abnormal leucine metabolism due to the genetic defect of IVD (Isovaleryl-CoA dehydrogenase). IVD corresponds to mitochondrial matrix enzyme that acts on converting isovaleryl-CoA into 3-methylcrotonyl-CoA in the leucine catabolism. The IVD gene is located at Chromosome 15q14-q15, particularly between base pair 40,405,485 and base pair 40,435,948. It consists of 12 exons and has been reported to cause over 50 diseases so far. We conducted IVD gene test on the patient with acute isovaleric acidemia and confirmed a new type of mutation for the first time. As a result of analyzing the IVD gene sequence, we found out that c.129T>G(p.Asn43Lys) and c.1033A>G(p.Asn345Asp) mutations exist as heterozygosity at Exon 1 and Exon 10 respectively, novel mutation.

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Prediction of Deformation Texture in BCC Metals based on Rate-dependent Crystal Plasticity Finite Element Analysis (속도의존성 결정소성 모델 기반의 유한요소해석을 통한 BCC 금속의 변형 집합조직 예측)

  • Kim, D.K.;Kim, J.M.;Park, W.W.;Im, Y.T.;Lee, Y.S.
    • Transactions of Materials Processing
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    • v.23 no.4
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    • pp.231-237
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    • 2014
  • In the current study, a rate-dependent crystal plasticity finite element method (CPFEM) was used to simulate flow stress behavior and texture evolution of a body-centered cubic (BCC) crystalline material during plastic deformation at room temperature. To account for crystallographic slip and rotation, a rate-dependent crystal constitutive law with a hardening model was incorporated into an in-house finite element program, CAMPform3D. Microstructural heterogeneity and anisotropy were handled by assigning a crystallographic orientation to each integration point of the element and determining the stiffness matrix of the individual crystal. Uniaxial tensile tests of single crystals with different crystallographic orientations were simulated to determine the material parameters in the hardening model. The texture evolution during four different deformation modes - uniaxial tension, uniaxial compression, channel die compression, and simple shear deformation - was investigated based on the comparison with experimental data available in the literature.

Biodegradation of fluorene and bioremediation study by Sphingobacterium sp. KM-02 isolated from PAHs-contaminated soil (PAHs 오염토양에서 분리된 Sphingobacterium sp. KM-02를 이용한 Fluorene 분해 및 토양복원 연구)

  • Nam, In-Hyun;Chon, Chul-Min;Kim, Jae-Gon
    • Journal of Soil and Groundwater Environment
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    • v.16 no.5
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    • pp.74-81
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    • 2011
  • The fluorene-degrading strain Sphingobacterium sp. KM-02 was isolated from PAHs-contaminated soil near a mineimpacted area by selective enrichment techniques. Fluorene added to the Sphingobacterium sp. KM-02 culture as sole carbon source was 78.4% removed within 120 h. A fluorene degradation pathway is tentatively proposed based on identification of the metabolic intermediates 9-fluorenone, 4-hydroxy-9-fluorenone, and 8-hydroxy-3,4-benzocoumarin. Further the ability of Sphingobacterium sp. KM-02 to bioremediate 100 mg/kg fluorene in soil matrix was examined by composting under laboratory conditions. Treatment of microcosm soil with the strain KM-02 for 20 days resulted in a 65.6% reduction in total amounts. These results demonstrate that Sphingobacterium sp. KM-02 could potentially be used in the bioremediation of fluorene from contaminated soil.

Ultrasonically Enhanced Liquid Flow through Porous Media and Variance of Influencing Factors (초음파 투사에 따른 흙시료 내 투수속도의 증가와 그 영향인자의 변화)

  • Kim Young-Uk;Yang Sung-Jae;Khim Jee-Hyeong
    • Journal of the Korean Geotechnical Society
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    • v.20 no.7
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    • pp.91-98
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    • 2004
  • This paper presented results of the laboratory tests conducted to investigate ultrasonically enhanced flow rate using specially designed and fabricated equipment. Influencing factor, ${\alpha}_i$ was verified to investigate the effect of ultrasound on soil matrix and flowing liquid. The test conditions involve soil types, temperature and ultrasonic energy. The test results indicate that ultrasound enhances the flow rate significantly. The degree of enhancement and the values of influencing factors, however, vary with test conditions.

Power System Harmonic Estimation Based on Park Transform

  • Chen, Ya;Ji, Tianyao;Li, Mengshi;Wu, Qinghua;Wang, Xuejian
    • Journal of Electrical Engineering and Technology
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    • v.11 no.3
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    • pp.560-574
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    • 2016
  • This paper presents a novel method for power system harmonic estimation based on the Park transform. The proposed method firstly extends the signal to a group of three-phase signals in a-b-c coordinate. Then, a linear fitting based method is adopted to estimate the fundamental frequency. Afterwards, the Park transform is utilized to convert the three-phase signals from a-b-c coordinate to d-q-0 coordinate. Finally, the amplitude and phase of a harmonic component of interest can be calculated using the d-axis and q-axis components obtained. Simulation studies have been conducted using matrix laboratory (MATLAB) and power system computer aided design/electromagnetic transients including direct current (PSCAD/EMTDC). Simulation studies in MATLAB have considered three scenarios, i.e., no-frequency-deviation scenario, frequency-deviation scenario and the scenario in the presence of inter-harminics. The results have demonstrated that the proposed method achieves very high accuracy in frequency, phase and amplitude estimation under noisy conditions, and suffers little influence of the inter-harmonics. Moreover, comparison studies have proved that the proposed method is superior to FFT and Interpolated FFT with the Hanning Window (IpFFTHW). Finally, a popular case in PSCAD/EMTDC has been employed to further verify the effectiveness of the proposed method.

Copula-ARMA Model for Multivariate Wind Speed and Its Applications in Reliability Assessment of Generating Systems

  • Li, Yudun;Xie, Kaigui;Hu, Bo
    • Journal of Electrical Engineering and Technology
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    • v.8 no.3
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    • pp.421-427
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    • 2013
  • The dependence between wind speeds in multiple wind sites has a considerable impact on the reliability of power systems containing wind energy. This paper presents a new method to generate dependent wind speed time series (WSTS) based on copulas theory. The basic feature of the method lies in separating multivariate WSTS into dependence structure and univariate time series. The dependence structure is modeled through the use of copulas, which, unlike the cross-correlation matrix, give a complete description of the joint distribution. An autoregressive moving average (ARMA) model is applied to represent univariate time series of wind speed. The proposed model is illustrated using wind data from two sites in Canada. The IEEE Reliability Test System (IEEE-RTS) is used to examine the proposed model and the impact of wind speed dependence between different wind regimes on the generation system reliability. The results confirm that the wind speed dependence has a negative effect on the generation system reliability.