The absorption spectra of aqueous solutions of monochIorotriazine reactive dyes, C.I. Reactive Red 9 and Reactive Orange 13 were measured in the presence of 5, 10, 25 and 50% (v/v) of ethanol, pyridine and dioxane-water mixtures and in varied concentrations of KCI, NaCl and LiCl. The varying position, intensity and shape of absorption bands are interpreted in terms of aggregation and disaggregation of dyes in solutions. The aggregation behaviour of the reactive dyes in solutions and in the presence of additives is related to their apparent deviations from Beer's law and aggregation numbers (N). The aggregation constant (K) of the rnonomer/dimer equilibrium is calculated..Dyes in ethanol-water mixtures record a larger aggregation number and aggregation constant than in the presence of pyridine. Dioxane is classified as a non-polar solvent and hence has a more disaggregating influence. The value of the aggregation number and constant are increased with increasing salt conentration and the order of degree of aggregation is KCl > NaCl > LiCl related to the order of ionic radii of K\ Na" and Li" ions. 507

In this paper, a bivariate Burr Type III distribution is constructed and some of its statistical properties such as bivariate probability density function and its marginal, joint cumulative distribution and its marginal, reliability and hazard rate functions are studied. The joint probability density function and the joint cumulative distribution are given in closed forms. The joint expectation of this distribution is proposed. The maximum likelihood estimation and prediction for a future observation are derived. Also, Bayesian estimation and prediction are considered under squared error loss function. The performance of the proposed bivariate distribution is examined using a simulation study. Finally, a data set is analyzed under the proposed distribution to illustrate its flexibility for real-life application.

Two simple, accurate and precise methods were presented for the simultaneous quantitative estimation of paracetamol and metoclopramide hydrochloride. The first is based on TLC separation of the two drugs, followed by densitometric measurement at 274 nm using a developing system composed of dichloromethane - methanol - conc. ammonia (8:2:0.05 by volume). The second method is based on UPLC separation of the cited drugs at 230 nm using C18 column and a mobile phase of 0.1% ortho-phosphoric acid (PH 3.5) – acetonitrile (70: 30, v/v). Regression analysis of Beer’s plots showed good correlations (r = 0.9996 - 0.9998) over concentration ranges of 1.5 – 15 and 0.1-0.6 μg/spot or 5-25 and 0.25 – 1.5 μg mL-l for paracetamol and metoclopramide  HCL using the two suggested methods, respectively. The proposed methods were also successfully applied to analyze both drugs in their pharmaceutical formulation; Migracid® tablets with mean recoveries ranging from 99.03 to 101.1%. The results obtained were validated as per ICH guidelines and statistically analyzed and found to be in accordance with those given by a reported method.

Burr Type III distribution have been mainly used in statistical modeling of events in a variety of applied mathematical contexts such as fracture roughness, life testing, meteorology, modeling crop prices, forestry, reliability analysis. Our aim of this work is to construct a bivariate Burr Type III distribution and some of its structural properties such as bivariate probability density function and it ' s marginal, joint cumulative distribution and it ' s marginal, reliability and hazard rate function are studied. The maximum likelihood estimators of the parameters are derived. The Bayes estimators of the parameters based on the squared error loss function and Bayesian prediction of the future observations are presented. The performance of the proposed bivariate distribution is examined using a simulation study. Finally, one data set under the proposed distributions to illustrate their flexibility for real-life applications is analyzed.