Exergetic and exergoeconomic analyses of a diesel engine fueled with binary and ternary blends of diesel–palm oil biodiesel–diethyl ether for various injection timings

Journal of Thermal Analysis and Calorimetry - In this study, ten different blends were prepared with binary and ternary combinations of diesel, palm oil biodiesel (0 vol%,...     

Fixed point theorems with respect to a contractive condition of integral type

We derive some fixed point theorems for mappings satisfying a contractive condition of integral type.     

Unanimity games and Pareto optimality

A central question in group decision theory is the existence of a simple mechanism that necessarily leads to Pareto optimal outcomes despite noncooperative behavior of the participants. It is shown that the multistage unanimity game is such a mechanism if we assume that the non-cooperative players end at an equilibria which is symmetric and persistent.     

Synthesis of heterocyclic systems with a carbohydrate fragment

Levoglucosenone, the ,ß-unsaturated ketone obtained by the pyrolysis of cellulose, reacts with NH-azoles in the presence of bases. In this process not only normal Michael adducts are formed, but in some cases their hydrates (gem-diols) are also formed. In all cases the addition proceeds stereospecifically and with good yields. 3-Nitro-s-triazole, 3-nitro- and 4-nitropyrazoles, 3-methyl-4-nitropyrazole, 5-nitrotetrazole, 4,5-dicarbomethoxy-v-triazole, 3,4-dinitropyrazole, 3(5)-methylpyrazole, pyrazole, and imidazole have been studied in this reaction. All of the adducts are characterized by NMR- and IR-spectroscopy.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1135–1140, June, 1994.     

Synthesis of fused indoles from 2,4,6-trinitrotoluene

4,6-Dinitro-1-tosylindoline prepared from trinitrotoluene undergoes base-catalyzed condensation with aromatic aldehydes. With salicylaldehyde and 2-hydroxynaphthalene-1-carbaldehyde, the condensation is accompanied by intramolecular nucleophilic substitution for one of the nitro groups to give benzo- and naphthooxepino[4,3,2-cd]indoles, respectively.     

Synthesis of dibenzo[b,f][1,4]oxazepin-11(10H)-ones from 2-nitrobenzoic acids

Base-catalyzed intramolecular nucleophilic substitution for the 2-nitro group in 2-hydroxyanilides of 2-nitrobenzoic acids gave dibenzo[b,f][1,4]oxazepin-11(10H)-ones. In particular, 3-nitrodibenzo[b, f][1,4]oxazepin-11(10H)-one was obtained from N-(2-hydroxyphenyl)-2,4-dinitrobenzamide. The nitro group in the product could also be replaced under the action of O- and S-nucleophiles. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 529–533, March, 2006.     

Interaction of levoglucosenone with malononitrile

Levoglucosenone reacts with malononitrile to form a product with a complex structure, which contains two levoglucosenone molecules and three malononitrile molecules. The conclusion about the structure of the product was based on the data of NMR, IR, and UV spectroscopy and mass spectrometry. The suggested reaction mechanism involves cascade cyclization. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 208–210, January, 1999.     

Synthesis and characterization of nanocomposites films with graphene oxide and reduced graphene oxide nanosheets

Graphene oxide (GO) and reduced graphene oxide (CRGO), as a graphene derivatives, possess unique properties and a high aspect ratio, indicating great potential in nanocomposite fields. The present work reports the fabrication of the nanocomposite films by a simple and environmentally friendly process using aqueous solution and optimized time sonication for better exfoliation of the graphene sheets within Poly(Vinyl alcohol) (PVA) as matrix. The films were characterized using high-resolution TEM (HRTEM), X-ray diffraction (XRD), Microtensile testing, Differential scanning calorimetry (DSC) and Thermogravimetric analysis (TGA). The TEM images revealed a successfully exfoliation of the GO/CRGO nanosheets. XRD combined with TGA and DSC measurements showed an improvement in the thermal stability and tunable thermal properties. In addition, the Young's modulus and tensile yield strength of the composite films containing 1 wt% GO were obtained to be 4.92 GPa and 66 MPa respectively. These excellent reinforcement effects were achieved by the strong interaction between the components.     

A fourth-order auxiliary variable projection method for zero-Mach number gas dynamics

A fourth-order numerical method for the zero-Mach-number limit of the equations for compressible flow is presented. The method is formed by discretizing a new auxiliary variable formulation of the conservation equations, which is a variable density analog to the impulse or gauge formulation of the incompressible Euler equations. An auxiliary variable projection method is applied to this formulation, and accuracy is achieved by combining a fourth-order finite-volume spatial discretization with a fourth-order temporal scheme based on spectral deferred corrections. Numerical results are included which demonstrate fourth-order spatial and temporal accuracy for non-trivial flows in simple geometries.