Estimation of the Weibull Distribution Parameters and Reliability Using Kernel and Bayes Approaches

A new estimation technique based on the non-parametric kernel density estimation is introduced as an alternative and reliable technique for estimation in life testing models. This technique estimates the density functions of the parameters and reliability directly from the data without any prior assumptions about the underlying distribution parameters. The efficiency of this technique has been studied comparing to the Bayesian estimation of the parameters and reliability of the Weibull distribution based on the non-informative, informative and the informative conjugate priors, via Monte Carlo simulations, which indicated the robustness of the proposed method than the Bayesian approach. Finally, a numerical example is given to illustrate the densities and the inferential methods developed in this paper

Statistical Inference for the Modified Weibull Model Based on the Generalized Order Statistics

In recent years, a new class of models has been proposed to exhibit bathtub-shaped failure rate functions. The modified Weibull is one of these models, which is a generalization for the Weibull distribution and is capable of modeling bathtub-shaped and increasing failure rate lifetime data. In this paper, conditional inference has been applied to constructing the confidence intervals for its parameters based on the generalized order statistics. For measuring the performance of this approach compared to the Asymptotic Maximum Likelihood estimates (AMLEs), simulations studies have been carried out for different values of sample sizes and shape parameters. The simulation results indicated that the conditional intervals possess good statistical properties and they can perform quite well even when the sample size is extremely small compared to the AMLE intervals. Finally, a numerical example is given to illustrate the confidence intervals developed in this paper

Recurrence Relations for Moment Generating Functions of the Generalized Compound Rayleigh Distribution

In this paper, we consider the three-parameter generalized compound Rayleigh distribution. The recurrence relations for moment generating functions based on the generalized order statistics are obtained. The results presented here are a generalization of the recurrence relations for Single and product moment generating functions, based on the ordinary order statistics and the upper record statistics for some lifetime distributions in the literature such as Beta-Prime, Lomax, Burr XII, and Compound Rayleigh distributions which are special cases from the generalized compound Rayleigh distribution

Characterization of the Generalized Life Model Based on the Generalized Order Statistics

In this paper, a characterization of the generalized life model based on some recurrence relations for single and product moments based on the generalized order statistics are obtained. The results presented here are a generalization of the recurrence relations for single and product moments of many lifetime distributions in the literature, which are special cases such as the generalized Pareto model and the generalized Weibull model based on the ordinary order statistics

Statistical Inference of Weibull Extension Distribution under Imprecise Data

In this paper, we present the maximum likelihood (ML) and Bayes estimation of the unknown parameters, the reliability and hazard functions of the Weibull extension distribution based on progressively Type-II censoring scheme from fuzzy lifetime data. For the computation of Bayes estimates, we proposed using Tierney-Kadane’s approximation under square error and LINEX loss functions. The performance of the maximum likelihood and Bayes estimators compared in terms of their mean squared errors (MSEs) through the simulation study. The results indicated that MSEs based on Tierney-Kadane’s approximation are less than based on the ML method. Finally, to demonstrate the efficiency of the proposed methods, two real data sets are analyzed

Preparation and evaluation of mebeverine hydrochloride as mucoadhesive buccal tablet for local anesthesia

Purpose: To formulate and evaluate an antispasmodic drug, mebeverine hydrochloride (Mbv-HCl), as a local anesthetic mucoadhesive buccal tablet.Methods: Mbv-HCl loaded tablets were formulated, using a direct compression technique, with varying polymer concentrations including carbopol 934P alone, carbopol 934P/hydroxypropyl methylcellulose (HPMC) mixture, or carbopol 934P/chitosan mixture. The tablets were evaluated for physicochemical characteristics, in-vitro drug release, bioadhesive strength, swelling, ex-vivo residence time, ex-vivo permeation, drug permeation through the buccal membrane of sheep, and stability.Results: The results indicate that formulation F4, which contains HPMC/carbopol 934P (3:1), showed the best in-vitro drug release profile. The release kinetics for all the formulations fitted well with Hixson- Crowell kinetic model. Bioadhesive strength, surface pH, and swelling index of F4 were 41.52, 6.36, and 231.2 %, respectively. Maximum residence time ex-vivo was exhibited by formulation F4, showing a maximum residence time of about 330 min with 80 % of Mbv-HCl permeated in 6 h ex-vivo. F4 was stable after storage for 60 days at 25 oC/60 % RH and 40 oC/75 % RH, with non-significant change (p < 0.05) in drug content, bioadhesive strength and in vitro release.Conclusion: The optimized mucoadhesive buccal formulation is promising for delivery of Mbv-HCl, and displays high bioadhesion and adequate permeability through sheep buccal membrane to achieve a local anesthetic action.Keywords: Mebeverine hydrochloride, Buccal, Mucoadhesive tablet, Swelling index, Bioadhesive strength, Local anestheti

The Antimicrobial Activity and the Median Lethal Dose of Thyme (Thymus vulgaris) Ethanolic Extract on Mice

The antimicrobial activities of thyme (thymes vulgaris) ethanolic extract was studied by agar well diffusion technique against tested organisms (Esherichia coli, Staphylococcus aureus and Candida albicans). The results were showed that the extract have antibacterial and antifungal activity against tested microorganisms. The results were also showed that the median lethal dose (LD50) of ethanolic extract of thyme in laboratory mice was about (4220 mg/kg B.w). The toxic signs during 24 hours after oral administration of thyme extract were rapid breathing, dullness, contraction of abdominal muscles, paralysis then death

The Effectiveness of the ”Creative Thinking Course” in [eveloping Creative Thinking Abilities of a Sample of Students in the Kingdom University in Bahrain

The aim of this study was to identify the effectiveness of the Creative Thinking Course (38121 on developing creative thinking skills (fluency, originality, elaboration, titling, resistance of closure, and the strength of creativity) in Bahraini University Students in the University of Kingdom. The study was based on a quasi-experimental method. Participants were (N=44) university students, (N= 24 female and N= 20 male). Torrance test of creative thinking (non-verbal A & B). Accordingly, this study attempted to verify the following hypothesis: Creative thinking skills are more improved after taking the Creative Thinking Course (38121. The study also sought to examine the differences between females and males in developing their creative thinking skills. The results indicate the effectiveness of the proposed training course in all creative thinking skills. There were significant differences (0.001) in the experimental group on post- non- verbal Torrance test (A, B) in all creative skills, which support the hypotheses of the study. There were no statistically significant differences related to gender differences

New Solutions for System of Fractional Integro-Differential Equations and Abel’s Integral Equations by Chebyshev Spectral Method

Chebyshev spectral method based on operational matrix is applied to both systems of fractional integro-differential equations and Abel’s integral equations. Some test problems, for which the exact solution is known, are considered. Numerical results with comparisons are made to confirm the reliability of the method. Chebyshev spectral method may be considered as alternative and efficient technique for finding the approximation of system of fractional integro-differential equations and Abel’s integral equations

LORNOXICAM-LOADED NANOSPONGES FOR CONTROLLED ANTI-INFLAMMATORY EFFECT: IN VITRO/IN VIVO ASSESSMENT

Objective: To design a controlled topical delivery system of lornoxicam (LX) in order to enhance skin permeation and treatment efficacy. Nanosponges were selected as a novel carrier for this purpose. Methods: Nanosponges were formulated via the emulsion solvent evaporation method using ethyl cellulose (polymer) and polyvinyl alcohol (surfactant). Nanosponge dispersions were characterized for colloidal properties, entrapment efficiency and in vitro release study. The nanosponge formulation (LS1) was then incorporated into carboxymethyl cellulose sodium hydrogels and evaluated for pH, viscosity and in vitro drug release. Skin irritation was evaluated, and anti-inflammatory activity was assessed via rat hind paw edema method. Results: Nanosponges were in the nano-sized range and attained a uniform round shape with a spongy structure. LS1exhibited the highest LX release after 6 h, so it was incorporated as hydrogel. Formulated hydrogels showed acceptable physicochemical parameters (pH, drug content and rheological properties). Skin irritation testing proved LX-loaded nanosponge hydrogel formulation (G1) to be non-irritant. In vivo study revealed an enhanced anti-inflammatory activity of G1 for 6 h (p<0.001). Conclusion: The developed nanosponge hydrogel is an efficient nanocarrier for improved and controlled topical delivery of LX