1,166 research outputs found

    Restarted Hessenberg method for solving shifted nonsymmetric linear systems

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    It is known that the restarted full orthogonalization method (FOM) outperforms the restarted generalized minimum residual (GMRES) method in several circumstances for solving shifted linear systems when the shifts are handled simultaneously. Many variants of them have been proposed to enhance their performance. We show that another restarted method, the restarted Hessenberg method [M. Heyouni, M\'ethode de Hessenberg G\'en\'eralis\'ee et Applications, Ph.D. Thesis, Universit\'e des Sciences et Technologies de Lille, France, 1996] based on Hessenberg procedure, can effectively be employed, which can provide accelerating convergence rate with respect to the number of restarts. Theoretical analysis shows that the new residual of shifted restarted Hessenberg method is still collinear with each other. In these cases where the proposed algorithm needs less enough CPU time elapsed to converge than the earlier established restarted shifted FOM, weighted restarted shifted FOM, and some other popular shifted iterative solvers based on the short-term vector recurrence, as shown via extensive numerical experiments involving the recent popular applications of handling the time fractional differential equations.Comment: 19 pages, 7 tables. Some corrections for updating the reference

    1-(But-2-enyl­idene)-2-(2-nitro­phen­yl)hydrazine

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    The mol­ecule of the title Schiff base compound, C10H11N3O2, adopts an E geometry with respect to the C=N double bond. The mol­ecule is roughly planar, with the largest deviation from the mean plane being 0.111 (2) Å, The enyl­idene-hydrazine group is, however, slightly twisted with respect to the phenyl ring, making a dihedral angle of 6.5 (3)°. An intra­molecular N—H⋯O hydrogen bond may be responsible for the planar conformation. An inter­molecular N—H⋯O hydrogen bond links two mol­ecules around an inversion center, building a pseudo dimer

    2-Eth­oxy-4-{[(2-nitro­phen­yl)hydrazono]meth­yl}phenol

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    The title compound, C15H15N3O4, a Schiff base, was obtained from a condensation reaction of 3-eth­oxy-4-hydroxy­benzaldehyde and 2-nitro­phenyl­hydrazine. The mol­ecule is approximately planar, the largest deviation from the mean plane being 0.1449 (16) Å. An intramolecular N—H⋯O inter­action is also present. In the crystal, inter­molecular O—H⋯O hydrogen bonds link the mol­ecules, forming chain parallel to the b axis

    TNFα induces Ca2+ influx to accelerate extrinsic apoptosis in hepatocellular carcinoma cells

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    BACKGROUND: Tumor necrosis factor-α has been proven an effective anticancer agent in preclinical studies. However, the translation of TNFα from research to clinic has been blocked by significant systemic toxicity and limited efficacy at maximal tolerated dose, which need urgently to be solved. METHODS: The level of cytosolic Ca RESULTS: Here, we demonstrated that TNFα induced extracellular Ca CONCLUSIONS: Our study provides the evidence supporting a novel mechanism by which TNFα induces extracellular C

    Numerical investigation of scale effect of various injection diameters on interaction in cold kerosene-fueled supersonic flow

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    Abstract: The incident shock wave generally has a strong effect on the transversal injection field in cold kerosene-fueled supersonic flow, possibly due to its affecting the interaction between incoming flow and fuel through various operation conditions. This study is to address scale effect of various injection diameters on the interaction between incident shock wave and transversal cavity injection in a cold kerosene-fueled scramjet combustor. The injection diameters are separately specified as from 0.5 to 1.5mm in 0.5mm increments when other performance parameters, including the injection angle, velocity and pressure drop are all constant. A combined three dimensional Couple Level Set & Volume of Fluids (CLSVOF) approach with an improved K-H & R-T model is used to characterize penetration height, span expansion area, angle of shock wave and sauter mean diameter (SMD) distribution of the kerosene droplets with/without considering evaporation. Our results show that the injection orifice surely has a great scale effect on the transversal injection field in cold kerosene-fueled supersonic flows. Our findings show that the penetration depth, span angle and span expansion area of the transverse cavity jet are increased with the injection diameter, and that the kerosene droplets are more prone to breakup and atomization at the outlet of the combustor for the orifice diameter of 1.5mm. The calculation predictions are compared against the reported experimental measurements and literatures with good qualitative agreement. The simulation results obtained in this study can provide the evidences for better understanding the underlying mechanism of kerosene atomization in cold supersonic flow and scramjet design improvement

    {4-Bromo-2-[3-(diethyl­ammonio)propyl­imino­meth­yl]phenolato}diiodidozinc(II) methanol solvate

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    In the title complex, [ZnI2(C14H21BrN2O)]·CH3OH, the asymmetric unit consists of a mononuclear zinc(II) complex mol­ecule and a methanol solvent mol­ecule. The compound was derived from the zwitterionic form of the Schiff base 4-bromo-2-[3-(diethyl­amino)propyl­imino­meth­yl]phenol. The ZnII atom is four-coordinated by the imine N and phenolate O atoms of the Schiff base ligand and by two iodide ions in a distorted tetra­hedral coordination. In the crystal structure, the methanol mol­ecules are linked to the Schiff base mol­ecules through N—H⋯O and O—H⋯O hydrogen bonds. One I atom is disordered over two positions in a 0.702 (19):0.298 (19) ratio

    1-(2-Furylmethyl­ene)-2-(2-nitro­phen­yl)hydrazine

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    The title Schiff base compound, C11H9N3O3, was obtained from a condensation reaction of furan-2-carbaldehyde and 2-nitro­phenyl­hydrazine. The mol­ecule is roughly planar, the largest deviation from the mean plane defined by all non-H atoms being 0.097 (4). An in ntra­molecular N—H⋯O hydrogen bond might influence the planar conformation of the mol­ecule. In the crystal, weak C—H⋯O hydrogen bonds link the mol­ecules, forming a chain

    {4-Bromo-2-[2-(piperidin-1-ium-1yl)ethyl­iminometh­yl]phenolato}diiodido­zinc(II)

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    In the title complex, [ZnI2(C14H19BrN2O)], the ZnII atom is four-coordinated by the imine N and phenolate O atoms of the Schiff base ligand and by two iodide ions in a distorted tetra­hedral coordination. In the crystal structure, mol­ecules are linked through inter­molecular N—H⋯O hydrogen bonds, forming chains running along the b axis

    Diiodido[N′-(2-methoxy­benzyl­idene)-N,N-dimethyl­ethane-1,2-diamine]zinc(II)

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    In the title complex, [Zn(C12H18N2O)I2], the ZnII ion is four-coordinated by the imine N and amine N atoms of the Schiff base ligand and by two iodide ions in a distorted tetra­hedral coordination
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