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951.
The effects of global Lewis number Le on the statistical behaviour of the unclosed terms in the transport equation of the Favre-filtered scalar dissipation rate (SDR) Ñ c have been analysed using a Direct Numerical Simulation (DNS) database of freely propagating statistically planer turbulent premixed flames with Le ranging from 0.34 to 1.2. The DNS data has been explicitly filtered to analyse the statistical behaviour of the unclosed terms in the SDR transport equation arising from turbulent transport T 1, density variation due to heat release T 2, scalar-turbulence interaction T 3, reaction rate gradient T 4, molecular dissipation (?D 2) and diffusivity gradients f(D) in the context of Large Eddy Simulations (LES). It Le has significant effects on the magnitudes of T 1, T 2, T 3, T 4, (?D 2) and f(D). Moreover, both qualitative and quantitative behaviours of the unclosed terms T 1, T 2, T 3, T 4, (?D 2) and f(D) are found to be significantly affected by the LES filter width Δ, which have been explained based on a detailed scaling analysis. Both scaling analysis and DNS data suggest that T 2, T 3, T 4, (?D 2) and f(D) remain leading order contributors to the SDR \(\tilde {{N}}_{c} \) transport for LES. The scaling estimates of leading order contributors to the SDR \(\tilde {{N}}_{c} \) transport has been utilised to discuss the possibility of extending an existing SDR model for Reynolds Averaged Navier Stokes (RANS) simulation for SDR \(\tilde {{N}}_{c} \) closure in the context of LES of turbulent premixed combustion. 相似文献
952.
Exploiting the diene nature of 6-[1-aza-2-(dimethylamino)prop-l-enyl]-1,3-dimethyluracil (2), novel 5-aryl-pyrido[2,3-d]pyrimidines (5a–h) have been synthesized. The reaction proceeds through a triene intermediate whose structure has been conclusively established by single crystal X-ray analysis. Role of water is intriguing as the reaction can be stopped at the intermediate stage. Synthesized compounds have been screened for possible antibacterial properties and results showed modest activity. 相似文献
953.
Nishant Kumar Verma Abhishek Chakraborty Ashis K. Chatterjee 《European Journal of Operational Research》2014
In the recent article, Darwish and Odah (2010) develop a scheme that allows for identical replenishment cycles for all the retailers, in the context of a single vendor supplying a group of retailers under VMI partnership. This paper proposes an alternative replenishment scheme allowing for different replenishment cycles for each retailer. An example has been shown to illustrate the cost savings under the proposed model. 相似文献
954.
955.
Nashed YE Mitra AK 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2003,59(9):2033-2039
Four dipeptide (Gly-Gly, Gly-Val, Val-Val, Val-Gly) ester prodrugs of 9-[(2-hydroxyethoxy)methyl]guanine (acyclovir, ACV) were synthesized. LC/MS was used to characterize the new prodrugs. Both 1H NMR and 13C NMR spectra of the four prodrugs of ACV were measured and assigned based on spectral comparison with compounds of similar structures. 相似文献
956.
Subhendra Mohanty Varun Sahni S. Chakraborty Ashok Goyal Sukanta Dutta Debajyoti Choudhury Shobhit Mahajan Amitabha Mukherjee Hatem Widyan Urjit Yajnik S. Mohanty J. A. Grifols Uma Mahanta Sarira Sahu Varun Sahni Tarun Souradeep Albert Stebbins Ioav Waga Vikram Soni N. Panchapakesan R. Brandenberger 《Pramana》1998,51(1-2):273-286
The astroparticle physics working group witnessed intense discussion and activity covering a broad range of topics ranging
from supergravity and baryogenesis to compact stars and the large scale structure of the Universe. A summary of some of the
subject areas in which collaborations were initiated during WHEPP-5 is presented below. 相似文献
957.
The preparation of PbS nanoparticle is important in material science. Due to its predominant ionic character and low optical band gap (0.41 eV), it shows quantum confinement effect up to a larger size domain compared to other well studied semiconductor materials, such as ZnS and CdS, having predominantly covalent character. In this report, we present a simpler method of preparation of nanosized PbS in micellar medium of the surfactant AOT and spectrophotometric, fluorimetric, light scattering and electron microscopic characterization of the dispersion. 相似文献
958.
A class of C∗-algebras called quantum Heisenberg manifolds were introduced by Rieffel in (Comm. Math. Phys. 122 (1989) 531) as strict deformation quantization of Heisenberg manifolds. Using the ergodic action of Heisenberg group we construct a family of spectral triples. It is shown that associated Kasparov modules are homotopic. We also show that they induce cohomologous elements in entire cyclic cohomology. The space of Connes-deRham forms have been explicitly calculated. Then we characterize torsionless/unitary connections and show that there does not exist a connection that is simultaneously torsionless and unitary. Explicit examples of connections are produced with negative scalar curvature. This part illustrates computations involving some of the concepts introduced in Frohlich et al. (Comm. Math. Phys. 203 (1999) 119), for which to the best of our knowledge no infinite-dimensional example is known other that the noncommutative torus. 相似文献
959.
We present a detailed analysis of the motion of test particle in the gravitational field of cosmic strings in different situations
using the Hamilton-Jacobi (H-J) formalism. We have discussed the trajectories near static cosmic string, cosmic string in
Brans-Dicke theory and cosmic string in dilaton gravity. 相似文献
960.
The ion current from an electron cyclotron resonance (ECR) heavy ion source depends on the confining axial and radial magnetic
fields. Some efforts were made by earlier workers to investigate magnetic field scaling on the performance of the ECR source.
In order to study the dependence of the ion current on the injection magnetic field in the 6.4 GHz ECR source, we have measured
the current by varying the peak injection field and have inferred that the variation of the current is exponential up to our
maximum design injection field of 7.5 kG. An attempt has been made to understand this exponential nature on the basis of ion
confinement time. 相似文献