45 research outputs found

    Electrical characteristics and modeling of a filamentary dielectric barrier discharge in atmospheric air

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    The electrical characteristics of a filamentary dielectric barrier discharge (DBD) are studied experimentally and numerically. The DBD system which has parallel plate electrodes geometry is powered by a 50 Hz power supply and operated at atmospheric air. A dynamic electric circuit model considering the discharge region and the non-discharge region being connected by a surface resistance is proposed. Simulation using this model is shown to fit the experimentally measured QV diagram satisfactorily. The effects of the air gap distance and the dielectric surface on the discharge behavior are then investigated. It is found that the surface resistivity of the dielectric is one of the important parameters governing the discharge behavior

    Impact of n-methyl-2-pyrrolidone in monoethanolamine solution to the co2 absorption in packed column: analysis via mathematical modeling

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    This work investigates the reason behind the change of CO2 absorption behaviour exhibited by monoethanolamine (MEA) solution via mathematical modeling analysis when physical absorbent, i.e. n-methyl-2-pyrrolidone (NMP), was added into the solution. The mathematical modeling included the heat model using time resolved numerical method. Based on the results, it was found that lower CO2 removal performance with the addition of NMP into MEA solution at pressure of 0.1 MPa was mainly due to the lower temperature rise along the column, which resulted in lower reaction rate. However, at 3 and 5 MPa pressure conditions, the high physical absorption capability contributed by the presence of NMP in MEA hybrid solution enhanced the CO2 absorption performance of MEA hybrid solution significantly. As such, temperature rise of solution was identified as the dominating factor affecting the performance of the hybrid solvent. The reaction rate of MEA was not affected by the addition of physical solvent. This finding shed crucial insight on the behaviour MEA-NMP hybrid solution which can be applied during scale-up of the process

    Array-based sequencing of filaggrin gene for comprehensive detection of disease-associated variants

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    The filaggrin gene (FLG) is essential for skin differentiation and epidermal barrier formation. FLG loss-of-function (LoF) variants are associated with ichthyosis vulgaris and the major genetic risk factor for developing atopic dermatitis (AD).1, 2, 3 Genetic stratification of patients with AD according to FLG LoF risk is a common practice for both research and clinical studies; however, few studies comprehensively sequence the entire FLG coding region. Most studies that include FLG genotyping have screened for common predominant LoF variants to report allele frequencies after full Sanger sequencing of a smaller batch of test patient samples or previously published data. This strategy potentially results in underreporting of the genetic contribution especially in ethnicities where FLG LoF variants are highly diverse.4 Distinct LoF variants have been reported for most ethnicities studied to date. For example, 2 predominant sequence variants (p.R501X and c.2282del4) make up approximately 80% of the mutation burden in northern Europeans,5 whereas in East Asian ethnicities, a larger FLG LoF mutation spectrum is found with fewer predominating variants.6, 7 However, routinely Sanger sequencing the entire FLG coding region for large cohorts is not always feasible, although desirable as it is essential to correctly stratify patients. To address this, we developed a robust and cost-effective high-throughput PCR-based method for analyzing the entire coding region of FLG using Fluidigm microfluidics technology and next-generation sequencing (NGS). We have applied this method to fully resequence cohorts of Chinese, Malay, and Indian patients with AD from the Singaporean population.ASTAR (Agency for Sci., Tech. and Research, S’pore)Published versio

    Structural and doping effects in the half-metallic double perovskite A2A_2CrWO6_6

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    he structural, transport, magnetic and optical properties of the double perovskite A2A_2CrWO6_6 with A=Sr, Ba, CaA=\text{Sr, Ba, Ca} have been studied. By varying the alkaline earth ion on the AA site, the influence of steric effects on the Curie temperature TCT_C and the saturation magnetization has been determined. A maximum TC=458T_C=458 K was found for Sr2_2CrWO6_6 having an almost undistorted perovskite structure with a tolerance factor f1f\simeq 1. For Ca2_2CrWO6_6 and Ba2_2CrWO6_6 structural changes result in a strong reduction of TCT_C. Our study strongly suggests that for the double perovskites in general an optimum TCT_C is achieved only for f1f \simeq 1, that is, for an undistorted perovskite structure. Electron doping in Sr2_2CrWO6_6 by a partial substitution of Sr2+^{2+} by La3+^{3+} was found to reduce both TCT_C and the saturation magnetization MsM_s. The reduction of MsM_s could be attributed both to band structure effects and the Cr/W antisites induced by doping. Band structure calculations for Sr2_2CrWO6_6 predict an energy gap in the spin-up band, but a finite density of states for the spin-down band. The predictions of the band structure calculation are consistent with our optical measurements. Our experimental results support the presence of a kinetic energy driven mechanism in A2A_2CrWO6_6, where ferromagnetism is stabilized by a hybridization of states of the nonmagnetic W-site positioned in between the high spin Cr-sites.Comment: 14 pages, 10 figure

    Transient three dimensional simulation of mold filling and wire sweep in an overmold BGA package

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    Proceedings - Electronic Components and Technology Conference897-904PECC

    Modeling brain deformation induced by ventriculoperitoneal shunting

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    10.1007/s11548-006-0023-yInternational Journal of Computer Assisted Radiology and Surgery1SUPPL. 7299-30

    Etching control of benzocyclobutene in CF4 / O2 and SF6 / O2 plasmas with thick photoresist and titanium masks

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    10.1016/j.tsf.2005.09.159Thin Solid Films5041-2252-256THSF

    Examination of cylindrical shell theories for buckling of carbon nanotubes

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    10.1142/S0219455411004464International Journal of Structural Stability and Dynamics1161035-105

    Immunotherapy of human cancers

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    Annals of the Academy of Medicine Singapore251113-119AAMS

    Prenatal diagnosis of α- and β-thalassaemias in Singapore - Current status

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    Annals of Tropical Paediatrics11167-74ATPA
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