This study describes a rapid and sensitive method for determination of Losartan potassium (LOS-K) in pure and medication forms. The method is depended upon the reaction of LOS-K with Silicotungestic acid in salt medium for the formation of a white precipitate. The new precipitate was monitored and measured using homemade Ayah 6SXI-T-2D Solar cell analyzer in combination with a continuous Flow injection technique. Reagent concentration, acid medium, Flow rate, sample volume, purge time, and delay coil reaction are all chemical and physical characteristics that have been investigated and optimized. The linear dynamic range of LOS-K was 0.05-2 mMol/L with linearity percentage (r2%) 99.56 %. Limit of detection (LOD) was 3.62 µg/sample and LOQ=18.28 µg/sample. A comparison between developed method and classical methods (UV-Spectrophotometry at λmax= 232 nm) was made. The proposed method was successfully applied for determination of LOS-K in the pharmaceutical samples and can be used as an alternative method.

Background: Anecdotal evidence suggests that a vertical small-needle injection method enters the caudal epidural space with comparable efficacy to cephalad-directed methods, with less intravascular injection.Objectives: Assess the success rate of vertical caudal epidural injection using epidurography and the frequency of intravascular injection using a vertical small-needle approach.Patients and Methods: Participants had chronic generalized non-surgical low back pain and either gluteal and/or leg pain and were enrolled in a simultaneous clinical trial assessing the analgesic effect of 5% dextrose epidural injection. A 25 gauge 3.7 cm hypodermic needle was placed at the sacral hiatus using a fingertip-guided vertical technique without imaging assistance, followed by fluoroscopic epidurography. Minimal needle redirection was allowed up to 10 degrees from the vertical plane if the initial epidurogram showed an extradural pattern, followed by repeat epidurography.Results: First needle placement without imaging resulted in blood return in 1/199 participants and positive epidurography in 179/199 (90%). Minimal needle repositioning resulted in a positive epidurogram in the remaining 19 attempts. No intravascular injection patterns were observed.Conclusions: This compares favorably to published success rates of fluoroscopically-guided technique and was well tolerated. Vertical caudal epidural injection may be suitable for combination with ultrasound-guided methods with Doppler Flow monitoring.

Film cooling technique is currently used in the gas turbine hot sections, such as the combustor wall and the turbine blades, to prevent those sections from failing at elevated temperatures. In the single hole film cooling method, coolant air is injected from a hole into the mainstream and thus the Flow is naturally three dimensional. In this paper, the Navier - Stokes and the energy equations are solved on a flat plate by the finite Element method using cubic elements. Algebraic equations are obtained by the use of the Petrov-Galerkin method. The pressure term is vanished from the momentum equations, by employing the penalty method. The governing equations are transient and the Flow is incompressible and turbulent. The model of turbulence in the near wall region is the wall function method, and in the fully turbulent region is the k-a model. The systems of the algebraic equations are solved by the Frontal method. The film cooling effectiveness data, at the optimum conditions, was directly compared with the experimental results of Goldstein et al. (1968), and a good agreement is demonstrated.

New Page 1 A chemiluminescence system is described for the determination of nitrite ion based on new designs for an ozone generator, liquid-gas separator and chemiluminescence reaction cell. The method is based on the gas-phase chemiluminescence reaction between ozone and nitric oxide, which is generated from the reduction of nitrite with iodide in sulfuric acid solution. The efficiency of the system was evaluated by investigation of the analytical performance characteristics of the system for nitrite determination in batch and Flow injection procedures. Under optimal conditions, the chemiluminescence response of the system was linear against the nitrite concentration over the range 1 to 1 ´ 104 ng ml-1 in the batch procedure and 10 to 5 ´ 103 ng ml-1 in the Flow injection procedure, with detection limits of 1 and 10 ng ml-1, respectively. The method is highly selective and allows for the determination of nitrite in the presence of high concentrations of several cationic, anionic and nitrogen containing species. It has been successfully applied to the analysis of nitrite in natural water and soil extracts.