Thermal conductivity modeling of nanofluids with ZnO particles by using approaches based on artificial neural network and MARS

Journal of Thermal Analysis and Calorimetry - Nanofluids are attractive alternatives for the current heat transfer fluids due to their remarkably higher thermal conductivity which leads to the...     

Life-cycle assessment (LCA) and techno-economic analysis of a biomass-based biorefinery

Journal of Thermal Analysis and Calorimetry - In this research, a biorefinery plant is proposed to generate biofuel through fast pyrolysis and gasification. The proposed biorefinery comprises...     

A solution procedure for the discrete time, cost and quality tradeoff problem using electromagnetic scatter search

Decisions concerning a project’s expedition, traditionally involved considerations regarding time and cost tradeoff. It was recently suggested that the quality of a project should also be taken into considerations. In this paper, we propose a meta-heuristic solution procedure for the discrete time, cost and quality tradeoff problem. This problem involves the scheduling of project activities in order to minimize the total cost of the project while maximizing the quality of the project and also meeting a given deadline. We apply a so called electromagnetic scatter search to solve this problem. In this process, we initially generate a population of feasible solutions. In so doing, we use frequency memory to well sample the feasible region. A number of these solutions are then selected and improved locally. The improved solutions are then combined to generate new set of solutions. The combination process utilizes attraction–repulsion mechanisms borrowed from the electromagnetism theory. The whole process is stopped when no significant improvement in the set of solutions are observed. The validity of the proposed solution procedure is demonstrated, and its applicability is tested on a randomly generated large and complex problem having 19,900 activities.     

An Efficient and Facile Synthesis of Quinoxaline Derivatives Catalyzed by KHSO4 at Room Temperature

Summary. A facile synthesis of quinoxaline derivatives catalyzed by KHSO₄ in very high yields at room temperature is reported.     

Pyrrole studies part 41. Reactivity of 3,4-diformyl-2,5-dimethylpyrrole with diaminoalkanes. An unusual formation of 2-azafulvenes

3,4-Diformyl-2,5-dimethylpyrrole (1) reacts with ,ω-diamino-alkanes, NH₂(CH₂)_nNH₂t' to form either the potentially tautomeric 2:2 macrocyclic adduct (7a) (8), when N = 2, or the potentially tautomeric 1:1 bicyclic adduct (18) (19), when N = 4, 5, 6, and 12. ¹H and ¹³C N.m.r. spectral data indicate that the 2-azafulvene structures predominate for both types of cycloadducts. Only polymeric material was obtained when N = 3.     

One-pot synthesis of 4,5-disubstituted 1,2,3-(NH)-triazoles by silica supported-zinc bromide in the aerobic condition

An efficient one-pot cross-coupling/1,3-dipolar cycloaddition sequence was developed for a convenient synthesis of 4,5-disubstituted-1,2,3-(NH)-triazoles, starting from various acid chlorides, terminal alkynes and sodium azide in the presence of silica supported-zinc bromide under aerobic conditions.     

One-pot three-component reaction: Synthesis of substituted β-cyanocarbonyls in aqueous media

An environmentally friendly and simple method for the synthesis of alkyl nitriles or β-cyanocarbonyls via a one-pot three-component reaction of Meldrum's acid, aldehydes and sodium cyanide in water, without using any catalyst or activation at room temperature is reported.     

“On-water” organic synthesis: <Emphasis Type="SmallCaps">l</Emphasis>-proline catalyzed synthesis of pyrimidine-2,4-dione-, benzo[<Emphasis Type="Italic">g</Emphasis>]- and dihydropyrano[2,3-<Emphasis Type="Italic">g</Emphasis>]chromene derivatives in aqueous media

In this work, functionalized pyrimidine-2,4-dione-, benzo[g]-, and dihydropyrano[2,3-g]chromene derivatives have been synthesized via a Michael addition of 2-hydroxy-1,4-naphthoquinone or 2,5-dihydroxy-1,4-benzoquinone to the Knoevenagel condensation product of an aldehyde with Meldrum’s acid, dimedone or barbituric acid in the presence of a catalytic amount of l-proline under refluxing conditions in water in good to excellent yields.