The interfacial tension of surfactant solutions is decreased with increasing surfactant concentration to obtain the critical micelle concentration (CMC). After that, the CMC values does not alter much. So this concentration is a critical point during surfactant flooding that is one of the chemical EOR techniques. The reduction of the CMC value is taken into consideration, since the surfactant f...

This article analyses the development of competitive party politics in post-communist East Central Europe from a comparative perspective. The central concerns are party system stabilisation and change in Hungary, Poland, the Czech Republic and Slovakia, and implications for comparative theory. Starting from Lipset and Rokkan’s ‘cleavage model’, the article assesses the relevance of their key va...

This paper uses the Banzhaf power measure to calculate the a priori voting power of individual voters under the existing Electoral College system for electing the President of the United States, as well as under variants of this system in which electoral votes are either apportioned among the states in a different manner or cast by the states in a different manner. While the present winner-take...

In this paper multiphase oscillators built using fractional-order allpass filters are presented. We examine the theory behind their operation and demonstrate their usefulness in the design of both multiphase and quadrature oscillators. Case design examples are given for various scenarios, while PSPICE and experimental results verify their operation

A series of copper and cobalt substituted nanospinel ferrites have been synthesized by the hydrothermal method. These compounds were characterized by FT-IR, XRD, EDX, SEM and VSM techniques. All of the synthesized nanospinel ferrites were found to be highly efficient and magnetically recoverable in the solvent-free synthesis of substituted 2,6-(2-hydroxybenzyl)-phenols (trisphenols). A wide ran...

Two new rare-earth dicyanamides, namely, Tb[N(CN)2]3‚2H2O and Eu[N(CN)2]3‚2H2O, have been prepared by ion exchange in aqueous solution, followed by evaporation of the solvent at room temperature. The structures of both compounds have been solved and refined from single-crystal and powder X-ray diffraction data, respectively. The two compounds are isostructural and are built up from irregular qu...

In this study, the effect of 1,2,3-trichloropropane (TCP) as trifunctional monomer on thermophysical properties of synthesized poly(ethylene tetrasulfide) (PETS) is investigated. To this end, different amounts of TCP (0-40 mol. % of halide-containing monomer) were incorporated into the structure of polysulfide polymer via interfacial condensation polymerization. Measuremen...

In this case study, exergy analysis is applied to a mini two-shaft gas turbine which is located in Islamic Azad University Khomeini Shahr Branch`s Thermodynamics laboratory and a proposal presented to make exergy destruction less using a Heat Recovery Water Heater (HRWH). Calculations were done for N2=20000 (rpm) constant and various N1 and after that for N1=600...

Results of magnetization and high-field electron spin resonance (ESR) studies of the new spin-1 Haldane-chain material [Ni(C2H8N2)2NO2] (BF4) (NENB) are reported. A definite signature of the Haldane state in NENB was obtained. From the analysis of the frequency–field dependence of magnetic excitations in NENB, the spin-Hamiltonian parameters were calculated, yielding 1/kB = 17.4 K, g‖ = 2.14, D...