a simple, inexpensive and efficient method was used for extraction and determination of fexofenadine and levocetirizine with three–phase hollow fiber liquid-phase microextraction and high-performance liquid chromatography. several parameters influencing the extraction recoveries such as the nature of organic extraction solvent, ph of donor and acceptor phases, stirring rate, extraction time and...

vanadium phosphorus oxides (vpo) has been applied as a heterogeneous catalyst in gas phase oxidation reactions and its application is very limited in liquid phase. in this study a series of cobalt-doped vanadium phosphorus oxides (vpo-co) catalysts with different loading of co (0.01-1.0 mol ratio of co/v) were prepared. oxidation of benzyl alcohol was studied in the liquid phase over vpo and vp...

The persistent and viscous nature of airway secretions in cystic fibrosis (CF) disease leads to airway obstruction, opportunistic infection, and deterioration of lung function. Thioredoxin (Trx) is a protein disulfide reductase that catalyzes numerous thiol-dependent cellular reductive processes. To determine whether Trx can alter the rheological properties of mucus, sputum obtained from CF pat...

the present study was designed to develop a simple, validated liquid chromatographic method for the analysis of azithromycin in bulk and pharmaceutical dosage forms using ultraviolet detector. the best stationary phase was determined as c18 column, 5 µm, 250 mm × 4.6 mm. mobile phase was optimized to obtain a fast and selective separation of the drug. flow rate was 1.5 ml/min, wavelength was se...

Constructing phase diagram and its subsequent quality lines for lean gas condensate reservoirs is always crucial and challenging topic in reservoir fluid studies. Due to small amounts of liquid drop-outs in lean gas condensates at reservoir conditions, full experimental tracking of phase diagram and its relevant quality lines is almost impossible for lean gas condensates.On the other hand, ...

coriolis mass flow meters are one of the most accurate tools to measure the mass flow in the industry. however, two-phase mode (gas-liquid) may cause severe operating difficulties as well as decreasing certitude in measurement. this paper presents a method based on fuzzy systems to correct the error and improve the reliability of these sensors in the presence of two-phase model fluid. definite ...

In this paper, an intuitive analysis of a phase noise reduction technique is done, and then a modified structure is proposed to achieve higher phase noise reduction than the original one. This method reduces the impact of noise sources on the phase noise by decreasing closed-loop gain in zero-crossings points and moving this high closed-loop gain to the non-zero-crossings points. This reduction...