Synthesis of 6-(N-azolyl)cyclohex-2-enones fromN-acetonylazoles

N-Acetonylazoles react with chalcones in the presence of a base to givetrans-3,5-disubstituted 6-(N-azolyl)cyclohex-2-enones. Usually, the reactions are fast and high-yielding. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 557–561, March, 1999.     

Lax Pairs and Integrability Conditions of Higher-Order Nonlinear Schrödinger Equations

We derive the Lax pairs and integrability conditions of the nonlinear Schrödinger equation with higher-order terms, complex potentials, and time-dependent coefficients. Cubic and quintic nonlinearities together with derivative terms are considered. The Lax pairs and integrability conditions for some of the well-known nonlinear Schrödinger equations, including a new equation which was not considered previously in the literature, are then derived as special cases. We show most clearly with a similarity transformation that the higher-order terms restrict the integrability to linear potential in contrast with quadratic potential for the standard nonlinear Schrödinger equation.     

A concise approach to chiral chromenes based on levoglucosenone

Levoglucosenone, a chiral α,β-unsaturated ketone derived from cellulose, undergoes a stereoselective domino oxa-Michael-aldol reaction with 2-hydroxybenzaldehydes affording optically active pyrano[3,4-b]chromenes. The latter are further converted into 2H-chromenes via a Beckmann fragmentation reaction.     

Improved Sensing Performance of Amperometric Urea Biosensor by Using Platinum Nanoparticles

A novel Platinum nanoparticle (PtNPs) modified Poly(pyrrole-co-1-(2-Aminophenyl)pyrrole)/Urease film coated Au electrode was designed for amperometric detection of urea. PtNPs quantity, film density and pH were optimized and interference effect of some substances readily found in municipal wastewater and blood was investigated. The biosensor responded to urea with a measurement concentration range of 0.1 to 30 mM, a sensitivity of 31.8 μA mM⁻¹ cm⁻², a LOD of 7.58 μM, an accuracy of 104 % and a RSD% of only 0.82. It sensed the concentration of urea in the municipal sewage water with recovery of 97.6 % (n=3) and remained 78 % of its initial response at 28^th day. Results confirmed that PtNPs with strong conductivity improved the electron transfer ability of the working electrode.     

Some Integral Inequalities Involving Metrics

In this work, we establish some integral inequalities involving metrics. Moreover, some applications to partial metric spaces are given. Our results are extension of previous obtained metric inequalities in the discrete case.     

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.