New, simple and sensitive batch and reverse FIA spectrophotometric methods for the determination of doxycycline hyclate in pure form and in pharmaceutical preparations were proposed. These methods based on oxidative coupling reaction between doxycycline hyclate and 3-methylbenzothiazolinone-2-hydrazone hydrochloride (MBTH) in the presence ammonium ceric sulfate in acidic medium, to form green water-soluble dye that is stable and has a maximum absorbance at 626 nm. A calibration graph shows that a Beer's law is obeyed over the concentration range of 1-80 and 0.5-110 ?g.mL-1 of DCH for the batch and rFIA respectively with detection limit of 0.325 ?g.mL-1 of DCH for r-FIA methods. All different chemicals and physical experimental parameters affecting the development and stability of the colored product were carefully studied. The proposed methods were successfully applied for the determination of DCH in pharmaceutical preparations.
This work deals with kinetics and chemical equilibrium studies of esterification reaction of ethanol with acetic acid. The esterification reaction was catalyzed by an acidic ion exchange resin (Amberlyst- 15) using a batch stirred tank reactor. The pseudo-homogenous and Eley-Rideal models were successfully fitted with experimental data. At first, Eley-Rideal model was examined for heterogeneous esterification of acetic acid and ethanol. The pseudo-homogenous model was investigated with a power-law model. The apparent reaction order was determined to be (0.88) for Ethanol and (0.92) for acetic acid with a correlation coefficient (R2) of 0.981 and 0.988, respectively. The reaction order was determined to be 4.1087x10-3 L0.8/(mol0.8.min) with
... Show MoreThe mechanism of the electronic flow rate at Al-TiO2 interfaces system has been studied using the postulate of electronic quantum theory. The different structural of two materials lead to suggestion the continuum energy level for Al metal and TiO2 semiconductor. The electronic flow rate at the Al-TiO2 complex has affected by transition energy, coupling strength and contact at the interface of two materials. The flow charge rate at Al-TiO2 is increased by increasing coupling strength and decreasing transition energy.
Background: Kocuria kristinae (earlier known as Rothia kristinae) is a relatively new opportunistic pathogen responsible for ear infections. The ability of this organism to form biofilms increases its resistance to therapy and promotes the development of antimicrobial resistance, necessitating new treatment methods. Objective: To assess the effect of 3-caffeoylquinic acid on K. kristinae isolated from patients with ear infections. Methods: Isolation of five clinical strains was done by conventional microbiological procedures. The ability of K. kristinae to form biofilms was determined by the crystal violet method (absorbance at OD₅₇₀) before and after 3-caffeoylquinic acid exposure; statistical data analysis was done using a
... Show MoreBackground: Benign Prostate Hypertrophy(BPH)is a common urological problem worldwide which is defined as denomatous hyperplasia of the periurethralpart of prostate gland that occurs especially in men over 50 years old and that tend to obstruct urination by constriction the urethra Objectives: The study was aimed to investigate the level of Malondialdehyde (MDA), Nitric Oxide (NO) and Superoxide Dismutase (SOD) as an antioxidant, besides other factors such as the level of Lipids Profile (Total Chlosterol (TC), High Density Lipoprotein Cholesterol (HDL-C), Low Density Lipoprotein Cholesterol (LDL-C), Very Low Density Lipoprotein Cholesterol (VLDL-C), and Triglyceride (TG))in patients suffer from BPH . Methods: In this study ;clinical ,spec
... Show MoreIn this paper, a modified derivation has been introduced to analyze the construction of C-space. The profit from using C-space is to make the process of path planning more safety and easer. After getting the C-space construction and map for two-link planar robot arm, which include all the possible situations of collision between robot parts and obstacle(s), the A* algorithm, which is usually used to find a heuristic path on Cartesian W-space, has been used to find a heuristic path on C-space map. Several modifications are needed to apply the methodology for a manipulator with degrees of freedom more than two. The results of C-space map, which are derived by the modified analysis, prove the accuracy of the overall C-space mapping and cons
... Show MoreIn the reverse engineering approach, a massive amount of point data is gathered together during data acquisition and this leads to larger file sizes and longer information data handling time. In addition, fitting of surfaces of these data point is time-consuming and demands particular skills. In the present work a method for getting the control points of any profile has been presented. Where, many process for an image modification was explained using Solid Work program, and a parametric equation of the profile that proposed has been derived using Bezier technique with the control points that adopted. Finally, the proposed profile was machined using 3-aixs CNC milling machine and a compression in dimensions process has been occurred betwe
... Show MoreSynthesis And Studies Of Complexes Of Some Elements With 2-Mercaptohiazole (2-HMBT)