A Priori Evaluation of the Laminar Flamelet Decomposition Model for Turbulent Premixed Flames using DNS Data

Laminar flamelet decomposition (LFD) is a dynamic approach for modelling sub-filter scale turbulence-chemistry interactions in Large-Eddy Simulations using a stretched flamelet library. In this work, the performance of the LFD model – that was previously used only in non-premixed combustion—is investigated a priori for premixed combustion using positively-strained flamelets in the reactant-to-product configuration. For this purpose, a DNS database of methane-air premixed flames is utilized. The flames are propagating in a rectangular box under homogeneous isotropic turbulence conditions over a wide range of Karlovitz numbers. The results show that the LFD model can correctly account for the sub-filter scale turbulence-chemistry interactions to predict the filtered reaction rates and the filtered scalar field, provided that turbulent and laminar mixing are well predicted. The deviations from the DNS results are attributed to the shortcomings of the strained flamelet library and the non-flamelet effects. Finally, the LFD results are compared with a different sub-filter scale model using the same strained flamlelet library, and the relative performances of the two models are discussed.—

     

Efficient One-Pot,Four-Component Synthesis of 1,2,3-Triazole-Linked Tetrahydrobenzo[b]pyrans

A one-pot procedure has been developed for the synthesis of (1,2,3-triazolyl) methoxyphenyl tetrahydro-5-oxo-4H-chromene derivatives by concurrent reaction of aryloxy propargylated aldehydes, various azides, active methylene compounds, and 1,3-cyclohexanediones using catalytic amounts of Cu(OAc)₂ / sodium ascorbate and diammonium hydrogen phosphate in aqueous ethanol media. Excellent conversion of starting materials was achieved to the desired (1,2,3-triazolyl) methoxyphenyl tetrahydro-5-oxo-4H-chromene products.     

EFFICIENT AND SELECTIVE OXIDATION OF THIOLS TO DISULFIDES BY 1,4-DIAZABICYCLO[2.2.2]OCTANE-DI-N-OXIDE-DI-PERHYDRATE UNDER NEUTRAL AND HETEROGENEOUS CONDITIONS

1,4-Diazabicyclo[2.2.2]octane-di-N-oxide-di-perhydrate[3pc] selectively oxidizes thiols to disulfides in acetonitrile in good yields. The method is generally useful for a wide variety of thiols.     

A Proline-Based Aminophosphinic Acid Ligand and It’s Vanadyl Complex: Synthesis,Characterization and In Vitro Inhibitory Effects on α-Amylase And α-Glucosidase

Abstract

A proline-based aminophosphinic acid ligand and it's vanadium complex have been synthesized and characterized by spectroscopic techniques. The inhibitory activity on pancreatic α-amylase and Baker's yeast α-glucosidase has been examined in vitro. The novel complex showed more inhibitory potency against pancreatic α-amylase and Baker's yeast α-glucosidase compared to acarbose as an antidiabetic drug.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

AN EFFICIENT PRO CEDURE FOR THE PREPARATION OF MONO,AND DI-BIS-INDOLYL METHANES CATALYZED BY MOLIBDATOPHOSPHORIC ACID

H ₃ PMo ₁₂ O ₄₀ · xH ₂ O was found to be an effective catalyst for the preparation of bis-indolyl derivatives from indole and aromatic, aliphatic, heterocyclic aldehydes or ketones in ethanol at room temperature.     

Protection of Alcohols and Phenols with Dihydropyran and Detetrahydropyranylation by ZrCl4

Alcohols and Phenols are protected efficiently with dihydropyran(DHP) in the presence of catalytic amounts of zirconium tetrachloride in dichloromethane. Deprotection of THP-ethers is also afforded in a methanolic solution at room temperature.     

A Classical Cosmological Model for Triviality

The aim of this paper is to study the triviality of λ ϕ⁴ theory in a classical gravitational model. Starting from a conformal invariant scalar tensor theory with a self-interaction term λ ϕ⁴, we investigate the effect of a conformal symmetry breaking emerging from the gravitational coupling of the large-scale distribution of matter in the universe. Taking in this cosmological symmetry breaking phase the infinite limit of the maximal length (the size of the universe) and the zero limit of the minimal length (the Planck length) implies triviality, i.e. a vanishing coupling constant λ. It suggests that the activity of the self-interaction term λ ϕ⁴ in the cosmological context implies that the universe is finite and a minimal fundamental length exists.     

S-Arithmetic Khintchine-Type Theorem

In this article we prove a convergence S-arithmetic Khintchine-type theorem for the product of non-degenerate ν-adic manifolds, where one of them is the Archimedean place.     

A practical and versatile approach toward a one-pot synthesis of 2,3-disubstituted 4(3H)-quinazolinones

Abstract  

An effective one-pot three-component route to 4(3H)-quinazolinones from commercially available starting materials is reported. Thus, isatoic anhydride reacted with ammonium acetate or primary amines and aldehydes in the presence of iodine to produce the corresponding quinazolinone derivatives in moderate to good yields.