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The New Topp-Leone Exponentiated Half Logistic-Gompertz-G Family of Distributions with Applications

2025-10-28T09:24:52Z

Title: The New Topp-Leone Exponentiated Half Logistic-Gompertz-G Family of Distributions with Applications Authors: Charumbira, Wellington; Broderick Oluyede; Fastel Chipepa Abstract: This research introduces a new family of distributions (FoD) titled the Topp-Leone Exponentiated-Half-Logistic-Gompertz-G (TL-EHL-Gom-G) distribution. The study explores a variety of statistical properties of the developed family, such as the quantile function, series expansion, order statistics, entropy, stochastic orders and moments. Through Monte Carlo simulations, various estimation techniques were compared, including the least squares (LS), Anderson Darling (AD), maximum likelihood (ML) and Cram\'er-von-Mises (CVM) methods via root mean square error (RMSE) and average bias (Abias). The results indicated that the ML estimation method performed better than other methods, hence, the selection for estimating the model parameters. To showcase the usefulness, robustness and applicability of the model, we applied it to three real-life data, including dataset with censored observations. The TL-EHL-Gom-W distribution, a special case of the TL-EHL-Gom-G FoD showed superiority over nested and non-nested models.

A New Topp–Leone Odd Weibull Flexible-G Family of Distributions with Applications

2025-10-28T07:40:23Z

Title: A New Topp–Leone Odd Weibull Flexible-G Family of Distributions with Applications Authors: Chipepa, Fastel; Mahmoud M. Abdelwahab; Charumbira, Wellington Fredrick; Mustafa M. Hasaballah Abstract: The acceptance of generalized distributions has significantly improved over the past two decades. In this paper, we introduce a new generalized distribution: Topp–Leone odd Weibull flexible-G family of distributions (FoD). The new FoD is a combination of two FOD; the Topp–Leone-G and odd Weibull-flexible-G families. The proposed FoD possesses more flexibility compared to the two individual FoD when considered separately. Some selected statistical properties of this new model are derived. Three special cases from the proposed family are considered. The new model exhibits symmetry and long or short tails, and it also addresses various levels of kurtosis. Monte Carlo simulation studies were conducted to verify the consistency of the maximum likelihood estimators. Two real data examples were used as illustrations on the flexibility of the new model in comparison to other competing models. The developed model proved to perform better than all the selected competing models.

Crystal engineering of robust metal-organic frameworks for applications in capture of carbon dioxide

2025-10-14T11:13:04Z

Title: Crystal engineering of robust metal-organic frameworks for applications in capture of carbon dioxide Authors: Gudyanga, Ishekudzwai Blessed Abstract: The atmospheric concentration of carbon dioxide gas (CO2) is of global concern given its continued rise. Burning of fossil fuel has increased since the beginning of the industrial revolution, which then increased the atmospheric CO2 concentration to > 400 ppm from 280 ppm. CO2 has an effect of trapping the sun’s heat, and is believed to be one of the cardinal contributors of global warming. In order to make improvements to the CO2 problem, carbon capture techniques have been proposed. MOFs are porous structures constructed from the coordinative bonding between metal ions and organic linkers or bridging ligands. Thus, having an enormous choices of metal clusters and organic linkers, MOFs possess a wide range of surface area, pore volume and functionality, and this has contributed to the consideration of them being versatile materials for storage, separation, and catalysis, etc. Therefore, there is need to synthesise MOFs which capture CO2 and convert it into useful chemicals such as methanol and formic acid for industrial application. Linker 2,2’-bipyridine-5,5’ dicarboxylic acid and ceric metal salt Ce(NO3)3·6H2O were used in this study. Two MOFs were synthesised by solvothermal method. These were characterised by TGA, PXRD, FTIR, Potentiostat Galvanostat and Gas Sorption. The two MOFs MSU-3 and MSU-4 were thermally and chemically stable. The thermal and chemical stability observed in the MOFs emanated from the presence of the rod secondary building unit, which are linked by the pyridyl carboxylate linker to give three dimensional structures. CO2 adsorption studies of the MOFs revealed a low uptake of the gas in comparison to those MOFs reported literature. MSU-3a and MSU-4a was tested for electroactivity. Also, resistivity was tested using electrical impedance spectroscopy. It was found out that both MOFs had a lower interfacial electron transfer resistance.

Quality evaluation of honey sold by informal traders in Harare, Zimbabwe

2025-09-22T08:47:08Z

Title: Quality evaluation of honey sold by informal traders in Harare, Zimbabwe Authors: Nyoka, R; Nyanhete, V.T; Mugadza, R.N; Usai, T; Masukume, B; Marume, P; Magogo, C Abstract: Honey, a valuable commodity accepted and used worldwide, is vulnerable to adulteration and its authenticity is of great importance. The study aimed at evaluating the quality of honey sold by informal traders in Harare, Zimbabwe. A structured questionnaire was used to determine the knowledge, attitudes and practices of honey sellers on honey adulteration. Physicochemical properties of honey such as moisture content, pH, total ash, reducing sugars, free acidity, diastase activity, electrical conductivity and hydroxymethylfurfural (HMF) were measured from 20 samples. Sensory attributes of honey samples were also measured using twelve semi trained panellists. The study revealed that 75% of honey sellers added something before selling. Only 25% of the honey sellers were knowledgeable about honey adulteration. Fifty percent of honey sellers stated their sources, some had the same source and some could not clearly explain their sources of honey. Twenty percent of the honey sellers stated that they can distinguish between adulterated and pure honey. Only 15% of the honey sellers were able to explain how they store honey before selling, some could not say and some stated that they get honey from the hive and go straight to the market. Physicochemical properties showed that there was a significant difference (p<0.05) in reducing sugars, viscosity, colour, HMF, moisture content, density between the samples and the control. There was a significant difference (p<0.05) in physicochemical attributes between the samples and the CODEX standards. Therefore, the results from this study concluded that honey that is sold by street vendors in Harare, Zimbabwe is adulterated and monitoring measures should be put in place to remove such from the market.