7,377 research outputs found

    Hybrid exciton-polaritons in a bad microcavity containing the organic and inorganic quantum wells

    Get PDF
    We study the hybrid exciton-polaritons in a bad microcavity containing the organic and inorganic quantum wells. The corresponding polariton states are given. The analytical solution and the numerical result of the stationary spectrum for the cavity field are finishedComment: 3 pages, 1 figure. appear in Communications in Theoretical Physic

    Enhancement in adsorption potential of microplastics in sewage sludge for metal pollutants after the wastewater treatment process

    Full text link
    © 2019 Elsevier Ltd Microplastics (MPs) as new pollutants of environmental concern have been widely detected in sewage sludge, and may act as significant vectors for metal pollutants due to their adsorption property. Our findings show that Cd, Pb, and Co, but not Ni, contents in sewage sludge are lower than that of corresponding metal irons adsorbed on sludge-based MPs, indicating that the MPs accumulate such metal pollutants as Cd in the sludge samples. In contrast to virgin MPs, sludge-based MPs are one order of magnitude higher adsorption capacity for Cd, which reaches up to 2.523 mg g−1, implying that there is a considerable enhancement in adsorption potential of the MPs for metals after the wastewater treatment process. SEM analysis shows that sludge-based MPs have rougher and more porous surface than virgin MPs, and FTIR spectra reveal that functional groups such as C–O and O–H are found on sludge-based MPs. Further, two-dimensional FTIR correlation spectroscopy indicates that C–O and N–H functional groups play a vital role in the process that sludge-based MPs adsorb Cd, which are not found in virgin MPs. The results imply that increased adsorption potentials of the sludge-based MPs to Cd are attributed to changes in the MP physicochemical properties during wastewater treatment process. In addition, such factors as pH value, and sludge inorganic and organic components also have an effect on the MP adsorption to Cd. Principal component analysis shows that the MPs could be divided into three categories, i.e. polyamide, rubbery MPs (polyethylene and polypropylene) and glassy MPs (polyvinyl chloride and polystyrene). Their adsorption potentials to Cd follow the decreasing order: polyamide > rubbery MPs > glassy MPs. In summary, these findings indicate that MPs may exert an important influence on fate and transport of metal pollutants during sewage sludge treatment process, which deserves to be further concerned

    Hidden Conformal Symmetry of Extremal Kerr-Bolt Spacetimes

    Full text link
    We show that extremal Kerr-Bolt spacetimes have a hidden conformal symmetry. In this regard, we consider the wave equation of a massless scalar field propagating in extremal Kerr-Bolt spacetimes and find in the "near region", the wave equation in extremal limit can be written in terms of the SL(2,R)SL(2,R) quadratic Casimir. Moreover, we obtain the microscopic entropy of the extremal Kerr-Bolt spacetimes also we calculate the correlation function of a near-region scalar field and find perfect agreement with the dual 2D CFT.Comment: 13 page

    Holographic Dual of Linear Dilaton Black Hole in Einstein-Maxwell-Dilaton-Axion Gravity

    Full text link
    Motivated by the recently proposed Kerr/CFT correspondence, we investigate the holographic dual of the extremal and non-extremal rotating linear dilaton black hole in Einstein-Maxwell-Dilaton-Axion Gravity. For the case of extremal black hole, by imposing the appropriate boundary condition at spatial infinity of the near horizon extremal geometry, the Virasoro algebra of conserved charges associated with the asymptotic symmetry group is obtained. It is shown that the microscopic entropy of the dual conformal field given by Cardy formula exactly agrees with Bekenstein-Hawking entropy of extremal black hole. Then, by rewriting the wave equation of massless scalar field with sufficient low energy as the SL(2, R)L_L×\timesSL(2, R)R_R Casimir operator, we find the hidden conformal symmetry of the non-extremal linear dilaton black hole, which implies that the non-extremal rotating linear dilaton black hole is holographically dual to a two dimensional conformal field theory with the non-zero left and right temperatures. Furthermore, it is shown that the entropy of non-extremal black hole can be reproduced by using Cardy formula.Comment: 15 pages, no figure, published versio

    Hidden conformal symmetry of extreme and non-extreme Einstein-Maxwell-Dilaton-Axion black holes

    Full text link
    The hidden conformal symmetry of extreme and non-extreme Einstein-Maxwell-Dilaton-Axion (EMDA) black holes is addressed in this paper. For the non-extreme one, employing the wave equation of massless scalars, the conformal symmetry with left temperature TL=M2πaT_{L}=\frac{M}{2\pi a} and right temperature TR=M2−a22πaT_{R}=\frac{\sqrt{M^{2}-a^{2}}}{2\pi a} in the near region is found. The conformal symmetry is spontaneously broken due to the periodicity of the azimuthal angle. The microscopic entropy is derived by the Cardy formula and is fully in consistence with the Bekenstein-Hawking area-entropy law. The absorption cross section in the near region is calculated and exactly equals that in a 2D CFT. For the extreme case, by redefining the conformal coordinates, the duality between the solution space and CFT is studied. The microscopic entropy is found to exactly agree with the area-entropy law.Comment: V3, typos corrected, version to appear in JHE

    Changes in Optical Conductivity due to Readjustments in Electronic Density of States

    Full text link
    Within the model of elastic impurity scattering, we study how changes in the energy dependence of the electronic density of states (EDOS) N(Ï”)N(\epsilon) around the Fermi energy Ï”F\epsilon_F are reflected in the frequency-dependent optical conductivity σ(ω)\sigma(\omega). While conserving the total number of states in N(Ï”)N(\epsilon) we compute the induced changes in σ(ω)\sigma(\omega) as a function of ω\omega and in the corresponding optical scattering rate 1/τop(ω)1/\tau_{\rm op}(\omega). These quantities mirror some aspects of the EDOS changes but the relationship is not direct. Conservation of optical oscillator strength is found not to hold, and there is no sum rule on the optical scattering rate although one does hold for the quasiparticle scattering. Temperature as well as increases in impurity scattering lead to additional changes in optical properties not seen in the constant EDOS case. These effects have their origin in an averaging of the EDOS around the Fermi energy Ï”F\epsilon_F on an energy scale set by the impurity scattering.Comment: 13 pages, 7 figure

    Characterization of the physicochemical, thermal and rheological properties of cashew kernel starch

    Get PDF
    The study aimed to characterize physicochemical, thermal, and rheological properties of cashew nut starch (CNS) and then compare the obtained results with the properties of potato and corn starches. CNS showed higher gelatinization temperatures (112.29 °C) than those noted for potato and maize starches (78.44–94.65 °C). In addition, CNS had higher peak viscosity (19.03 mPa·s) than high amylose corn starch. The static shear rheological test indicated that the CNS followed a pseudoplastic behavior. In addition, CNS sample showed a thixotropic patter, which was less pronounced than that observed for potato starch, but higher than the value reported for high amylose corn starch. These results demonstrated that the shear resistance of CNS was lower than high amylose corn starch, but higher than potato starch. The storage and loss modulus (G' and G“, respectively) of the CNS were higher than those reported for the rest of samples. In this line, elastic properties were predominant in CNS sample. In conclusion, results from this study provided insight into physicochemical and structural properties of cashew nut starch, which could represent a preliminary step for its future application in food processing.Fil: Chen, Nan. Shandong Academy of Agricultural Sciences; China. Jilin Agricultural University; ChinaFil: Wang, Qing. Shandong Academy of Agricultural Sciences; ChinaFil: Wang, Mu Xuan. Shandong Academy of Agricultural Sciences; ChinaFil: Li, Ning yang. Shandong Agricultural University; ChinaFil: Briones, Annabelle V.. Dost Complex; FilipinasFil: Cassani, LucĂ­a Victoria. Universidad de Vigo; España. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: Prieto, M. A.. Universidad de Vigo; EspañaFil: Carandang, Maricar B.. Dost Complex; FilipinasFil: Liu, Chao. Ministry Of Agriculture Of The People's Republic Of China; ChinaFil: Gu, Chun Mei. Jilin Agricultural University; ChinaFil: Sun, Jin Yue. Ministry Of Agriculture Of The People's Republic Of China; Chin

    Quantitative analysis of powder mixtures by raman spectrometry : the influence of particle size and its correction

    Get PDF
    Particle size distribution and compactness have significant confounding effects on Raman signals of powder mixtures, which cannot be effectively modeled or corrected by traditional multivariate linear calibration methods such as partial least-squares (PLS), and therefore greatly deteriorate the predictive abilities of Raman calibration models for powder mixtures. The ability to obtain directly quantitative information from Raman signals of powder mixtures with varying particle size distribution and compactness is, therefore, of considerable interest In this study, an advanced quantitative Raman calibration model was developed to explicitly account for the confounding effects of particle size distribution and compactness on Raman signals of powder mixtures. Under the theoretical guidance of the proposed Raman calibration model, an advanced dual calibration strategy was adopted to separate the Raman contributions caused by the changes in mass fractions of the constituents in powder mixtures from those induced by the variations in the physical properties of samples, and hence achieve accurate quantitative determination for powder mixture samples. The proposed Raman calibration model was applied to the quantitative analysis of backscatter Raman measurements of a proof-of-concept model system of powder mixtures consisting of barium nitrate and potassium chromate. The average relative prediction error of prediction obtained by the proposed Raman calibration model was less than one-third of the corresponding value of the best performing PLS model for mass fractions of barium nitrate in powder mixtures with variations in particle size distribution, as well as compactness

    Role of the CCAAT-Binding Protein NFY in SCA17 Pathogenesis

    Get PDF
    Spinocerebellar ataxia 17 (SCA17) is caused by expansion of the polyglutamine (polyQ) tract in human TATA-box binding protein (TBP) that is ubiquitously expressed in both central nervous system and peripheral tissues. The spectrum of SCA17 clinical presentation is broad. The precise pathogenic mechanism in SCA17 remains unclear. Previously proteomics study using a cellular model of SCA17 has revealed reduced expression of heat shock 70 kDa protein 5 (HSPA5) and heat shock 70 kDa protein 8 (HSPA8), suggesting that impaired protein folding may contribute to the cell dysfunction of SCA17 (Lee et al., 2009). In lymphoblastoid cells, HSPA5 and HSPA8 expression levels in cells with mutant TBP were also significantly lower than that of the control cells (Chen et al., 2010). As nuclear transcription factor Y (NFY) has been reported to regulate HSPA5 transcription, we focused on if NFY activity and HSPA5 expression in SCA17 cells are altered. Here, we show that TBP interacts with NFY subunit A (NFYA) in HEK-293 cells and NFYA incorporated into mutant TBP aggregates. In both HEK-293 and SH-SY5Y cells expressing TBP/Q61∌79, the level of soluble NFYA was significantly reduced. In vitro binding assay revealed that the interaction between TBP and NFYA is direct. HSPA5 luciferase reporter assay and endogenous HSPA5 expression analysis in NFYA cDNA and siRNA transfection cells further clarified the important role of NFYA in regulating HSPA5 transcription. In SCA17 cells, HSPA5 promoter activity was activated as a compensatory response before aggregate formation. NFYA dysfunction was indicated in SCA17 cells as HSPA5 promoter activity reduced along with TBP aggregate formation. Because essential roles of HSPA5 in protection from neuronal apoptosis have been shown in a mouse model, NFYA could be a target of mutant TBP in SCA17
    • 

    corecore