Spectrophotometric and spectrofluorimetric determinations of veterinary drug enrofloxacin in pharmaceutical formulation

Four simple, sensitive spectrophotometric and spectroflourimetric methods (A-D) for the determination of veterinary drug enrofloxacin (ENFX) in pharmaceutical formulation have been developed. Method (A) is based on formation of ternary complex of ENFX with Pd(II) in presence of methyl cellulose as surfactant and acetate-HCl buffer pH 4.0. Method (B) is based on the oxidation of ENFX with alkaline potassium permanganate to give a green colored reaction product. The reaction was monitored spectrophotometrically by measuring the absorbance of the reaction product at 604 nm. Method (C) is based on the oxidation of the ENFX by a known excess of potassium permanganate in acid medium and subsequent determination of unreacted oxidant by reacting it with safronine O (SFO). Method (D) is based on the chelation of ENFX with Zr(IV), to produce fluorescent chelate. At the optimum reaction conditions, the drug/metal chelate showed excitation maxima at 280 nm and emission maxima at 440 nm. The optimum experimental parameters for the reaction have been studied. The validity of the described procedures was assessed. Statistical analysis of the results has been carried out revealing high accuracy and good precision. The proposed methods were successfully applied for the determination of the selected drug in pharmaceutical preparations with good recoveries. The procedures were accurate, simple and suitable for quality control application.     

Active incremental Support Vector Machine for oil and gas pipeline defects prediction system using long range ultrasonic transducers

This work proposes a long range ultrasonic transducers technique in conjunction with an active incremental Support Vector Machine (SVM) classification approach that is used for real-time pipeline defects prediction and condition monitoring. Oil and gas pipeline defects are detected using various techniques. One of the most prevalent techniques is the use of “smart pigs” to travel along the pipeline and detect defects using various types of sensors such as magnetic sensors and eddy-current sensors. A critical short coming of “smart pigs” is the inability to monitor continuously and predict the onset of defects. The emergence of permanently installed long range ultrasonics transducers systems enable continuous monitoring to be achieved. The needs for and the challenges of the proposed technique are presented. The experimental results show that the proposed technique achieves comparable classification accuracy as when batch training is used, while the computational time is decreased, using 56 feature data points acquired from a lab-scale pipeline defect generating experimental rig.     

Reflection Spaces, Partial K-Loops and K-Loops

Starting from a paper by Sperner (Archiv der Mathematik 5:458?C468, 1954) we introduce the notion reflection space and inside this concept, transitive elliptic and non-elliptic reflection spaces. On a transitive and non-elliptic reflection space we can apply the so called K-loop derivation and obtain a K-loop with fibration. In order to achieve similar results for elliptic reflection spaces we have to claim further conditions (the existence of a so called midpoint domain) and to extend the notion K-loop to partial K-loop with fibration.     

Comprehensive evaluation of the effluents eluted from different processes of the textile industry and its immobilization to trim down the environmental pollution

Due to the significance of industrial waste water pollution, which creates severe health hazards in humans, this study concentrates over the reduction and determination of the amounts of toxic metals/pollution parameters in the effluents leached from different processes of the textile industry. The concentrations of metal ions were measured by using neutron activation analysis (NAA) technique. The values of toxic metals such as As (49.1 ± 1.8 mg/L), Cu (42.7 ± 1.5 mg/L), Ni (41.1 ± 3.3 mg/L), Mn (51.1 ± 0.7 mg/L), Sb (1.89 ± 0.04 mg/L), Se (0.41 ± 0.01 mg/L), Co (7.5 ± 0.3 mg/L), Cr (8.5 ± 0.5 mg/L) and Cd (1.21 ± 0.08 mg/L) were found very high in crude textile??s effluents as compared to their standard recommended limits. The immense variation observed among the injurious pollutants of the effluents i.e. pH, temperature, electrical conductivity, turbidity, biological oxygen demands, chemical oxygen demands, total suspended solids, total dissolved solids, total solids etc. The toxic metals and injurious pollutants in the unprocessed effluents have been reduced in the post filtration effluents up to 98% and 96% respectively with the help of an ultra-filtration membrane therapy unit.     

Alleviation of adverse effects of drought stress on growth and some potential physiological attributes in maize (Zea mays L.) by seed electromagnetic treatment

Effects of varying preseed magnetic treatments on growth, chlorophyll pigments, photosynthesis, water relation attributes, fluorescence and levels of osmoprotectants in maize plants were tested under normal and drought stress conditions. Seeds of two maize cultivars were treated with different (T0 [0 mT], T1 [100 mT for 5 min], T2 [100 mT for 10 min], T3 [150 mT for 5 min] and T4 [150 mT for 10 min]) electromagnetic treatments. Drought stress considerably suppressed growth, chlorophyll a and b pigments, leaf water potential, photosynthetic rate (A), stomatal conductance (g(s)) and substomatal CO(2) concentration (C(i)), while it increased leaf glycinebetaine and proline accumulation in both maize cultivars. However, pretreated seeds with different magnetic treatments significantly alleviated the drought-induced adverse effects on growth by improving chlorophyll a, A, E, g(s), C(i) and photochemical quenching and nonphotochemical quenching, while it had no significant effect on other attributes. However, different magnetic treatments negatively affected the g(s) and C(i) particularly in cv. Agaiti-2002 under drought stress conditions. Of all magnetic treatments, 100 and 150 mT for 10 min were most effective in alleviating the drought-induced adverse effects. Overall, preseed electromagnetic treatments could be used to minimize the drought-induced adverse effects on different crop plants.     

Efficient Synthesis of Urea Derivatives via a Sequential One-Pot Nucleophilic Addition/Ugi Five-Component Reaction Under Solvent-Free Conditions

Urea polyfunctional derivatives were successfully synthesized via a one-pot, five-component nucleophilic addition/Ugi reaction sequence. Simplicity, solvent-free conditions, and good yields of products are advantages of this method.     

Radiation-induced grafting of styrene onto ultra-high molecular weight polyethylene powder and subsequent film fabrication for application as polymer electrolyte membranes: I. Influence of grafting conditions

Ultra-high molecular weight polyethylene (UHMWPE) powder was irradiated by gamma rays using a ⁶⁰Co source. Simultaneous and pre-irradiation grafting was performed in air and in inert atmosphere at room temperature. The monomer selected for grafting was styrene, since the styrene-grafted UHMWPE could be readily post-sulfonated to afford proton exchange membranes (PEMs). The effect of absorbed radiation dose and monomer concentration in methanol on the degree of grafting (DG) is discussed. It was found that the DG increases linearly with increase in the absorbed dose, grafting time and monomer concentration, reaching a maximum at a certain level. The order of rate dependence of grafting on monomer concentration was found to be 2.32. Furthermore, the apparent activation energy, calculated by plotting the Arrhenius curve, was 11.5 kJ/mole. Lower activation energy and high rate dependence on monomer concentration shows the facilitation of grafting onto powder substrate compared with film. The particle size of UHMWPE powder was measured before and after grafting and found to increase linearly with increase in level of grafting. FTIR-ATR analysis confirmed the styrene grafting. The grafted UHMWPE powder was then fabricated into film and post-sulfonated using chlorosulfonic acid for the purposes of evaluating the products as inexpensive PEM materials for fuel cells. The relationship of DG with degree of substitution (DS) of styrene per UHMWPE repeat unit and ion exchange capacity (IEC) is also presented.     

Micellar properties of a phenothiazine drug in presence of additives

In this study micellar properties of a phenothiazine drug, promazine hydrochloride, at different concentrations of NaCl and cationic surfactants (conventional as well as gemini surfactants) are presented. The parameters studied are cmc (critical micelle concentration), X ₁ (mole fraction of surfactant in micelles), f ₁, f ₂ (activity coefficients) and ΔG _ex (excess free energy). Cl⁻ ions (from NaCl) get adsorbed on the micellar head groups and, by decreasing the repulsion among them, lower the cmc. Surfactants form mixed micelles with the drug and the values of X ₁, X ₁^id (mole fraction of the surfactant in micelles in ideal state), interaction parameter β, f ₁ and f ₂ all suggest non-ideal but synergistic nature. The ΔG _ex values are negative indicating that the mixed state is more stable than the pure micelle state. The article is published in the original.     

Synthesis of some cyclopentenones and crystal structure of 4-hydroxy-3,4-bis(4-methoxyphenyl)-5,5-dimethyl-2-cyclopenten-1-one

Abstract  

Sodium-hydroxide-catalyzed condensation of di-p-methyl- and di-p-methoxybenzil with acetone derivatives was investigated in methanol. Di- and trisubstituted products were obtained as cyclopentenones, while tetraaryl-substituted systems were isolated as cyclopentadienones. The structures of the products were identified by elemental analysis, infrared (IR), nuclear magnetic resonance (¹H NMR), and mass spectroscopy. The solid-state structure of 4-hydroxy-3,4-bis(4-methoxyphenyl)-5,5-dimethyl-2-cyclopenten-1-one was further studied by single-crystal X-ray diffraction analysis. The title compound crystallizes in an orthorhombic space group and intermolecular O–H···O and C–H···O hydrogen bonds stabilize the crystal lattice.     

Bemerkungen zum Beweis des Darstellungssatzes für miquelsche Möbius-Ebenen von A. Lenard

Ohne Zusammenfassung