Environmentally Benign Synthesis of 2-Pyrazolines and Cyclohexenones Incorporating Naphthalene Moiety and Their Antimicrobial Evaluation

We reported the environmental benign synthesis of chalcones,2-pyrazolines and cyclohexanones under microwave irradiation.Chalcones were obtained by the condensation of each of 2-hydroxyacetophenone derivatives with a-naphthaldehyde under microwave irradiation.The condensation reactions of each of synthesized chalcones with phenyl hydrazine under microwave irradiation in the presence of dry acetic acid as a cyclizing agent gave 2-pyrazolines.Also,the new cyclohexenone derivatives,valuable intermediates to synthesize fused heterocycles,have been prepared by the cyclocondensation of each of hydroxychalcones with ethyl acetoacetate.The structures of the synthesized compounds were elucidated by infrared（IR） spectrometry,nuclear magnetic resonance（NMR）,mass spectrometry（MS） and elmental analysis.The results indicate that unlike classical heating,microwave irradiation results in higher yields with shorter and cleaner reactions.The synthesized compounds were screened for antimicrobial activity against Staphylococcus aureus,Escherichia coli,Candida Albicans and Aspergillus niger.We clarified the effects of different substituents in the tested compounds on the obtaind antibacterial activities and antifungal activities.     

Stabilization of Catalytically Active Cu+ Surface Sites on Titanium–Copper Mixed‐Oxide Films

The oxidation of CO is the archetypal heterogeneous catalytic reaction and plays a central role in the advancement of fundamental studies, the control of automobile emissions, and industrial oxidation reactions. Copper‐based catalysts were the first catalysts that were reported to enable the oxidation of CO at room temperature, but a lack of stability at the elevated reaction temperatures that are used in automobile catalytic converters, in particular the loss of the most reactive Cu⁺ cations, leads to their deactivation. Using a combined experimental and theoretical approach, it is shown how the incorporation of titanium cations in a Cu₂O film leads to the formation of a stable mixed‐metal oxide with a Cu⁺ terminated surface that is highly active for CO oxidation.     

Some Inequalities Concerning the Polar Derivative of a Polynomial-II

In this paper, we consider the class of polynomials P（z）= anz^n＋ ∑vn=μan-vz^n-v,1≤μ≤n , having all zeros in ｜z｜≤k, k ≤1 and thereby present an alternative proof, independent of Laguerre＇s theorem, of an inequality concerning the polar derivative of a polynomial.     

Four-wave mixing reduction technique based on smart filter approach

This paper proposed a new technique to suppress the four-wave mixing (FWM) effect by using a smart filter technique. The behaviour of FWM and the performance of wavelength division multiplexing systems with 4 and 16 channels were simulated in the presence of the proposed technique. The simulation was also performed under different parameters such as input power, number of channels and channel spacing. The FWM power drastically decreases by 12 and 19 dB for the 4 and 16 channels, respectively, when the smart filter is used as compared with the conventional system. In terms of system performance, the suggested approach for 4 and 16 channels at the first channel offers low bit error rate (BER) values of 3.23 × 10^?23 and 1.7 × 10^?21, respectively. The smart filter with the channel spacing variation for the 4-channel system subsequently improved the BER value at the fourth channel. Results confirm that the smart filter approach is an active solution that can suppress the FWM effect in optical transmission systems.     

Low operating temperature of oxygen gas sensor based on undoped and Cr-doped ZnO films

Undoped and doped ZnO with 1 at.% (atomic percentage) chromium (Cr) was synthesized by RF reactive co-sputtering for oxygen gas sensing applications. The prepared films showed a highly c-oriented phase with a dominant (0 0 2) peak at a Bragg angle of around 34.2°. The operating temperature of the prepared ZnO sensor was around 350 °C and shifted to around 250 °C for the doped ZnO sensor which is lower than that of previously reported work. The sensitivity of the sensor toward oxygen gas was enhanced by doping ZnO with 1 at.% Cr. Good stability and repeatability of the sensor were demonstrated when tested under different concentration of oxygen atmosphere.     

A Two-Parameter Deformed N = 2 SUSY Algebra

A two-parameter deformed N = 2 SUSY algebra is constructed by using the q-deformed bosonic and fermionic Newton oscillator algebras. The Fock space representation of the (q ₁,q ₂)-deformed N = 2 SUSY algebra is analyzed. The comparison between the algebra constructed and earlier versions of deformed N = 2 SUSY algebras is also made.     

Indirect spectrophotometric determination of chromium(VI)

A new simple and sensitive spectrophotometric method for the determination of chromium(VI) is established. It relies upon the oxidation of iron(II) with the titled ion, in acidic medium, to form iron(III) which is complexed with tiron to form a stable blue color with maximum absorption at 650 nm. Adherence to Beer's law is observed in the range 10–100 μg of chromium(VI) per 25 ml, with a molar absorptivity of 5.6 × 10³ liters mol^?1 cm^?1, sensitivity index of 0.0093 μg cm^?1, relative error of ?5.0 to +0.3%, and relative standard deviation of 0.3–4.0%, depending on the concentration level. Furthermore, the reaction needs neither temperature control nor an extraction step.     

Some Solutions for a Class of Singular Equations

In this paper we obtain all solutions which depend only on r for a class of partial differential equations of higher order with singular coefficients.     

Organocatalytic depolymerization of poly(ethylene terephthalate)

We describe the organocatalytic depolymerization of poly(ethylene terephthalate) (PET), using a commercially available guanidine catalyst, 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene (TBD). Postconsumer PET beverage bottles were used and processed with 1.0 mol % (0.7 wt %) of TBD and excess amount of ethylene glycol (EG) at 190 °C for 3.5 hours under atmospheric pressure to give bis(2‐hydroxyethyl) terephthalate (BHET) in 78% isolated yield. The catalyst efficiency was comparable to other metal acetate/alkoxide catalysts that are commonly used for depolymerization of PET. The BHET content in the glycolysis product was subject to the reagent loading. This catalyst influenced the rate of the depolymerization as well as the effective process temperature. We also demonstrated the recycling of the catalyst and the excess EG for more than 5 cycles. Computational and experimental studies showed that both TBD and EG activate PET through hydrogen bond formation/activation to facilitate this reaction. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011