293 research outputs found

    Transmuted Lindley-Geometric Distribution and its applications

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    A functional composition of the cumulative distribution function of one probability distribution with the inverse cumulative distribution function of another is called the transmutation map. In this article, we will use the quadratic rank transmutation map (QRTM) in order to generate a flexible family of probability distributions taking Lindley geometric distribution as the base value distribution by introducing a new parameter that would offer more distributional flexibility. It will be shown that the analytical results are applicable to model real world data.Comment: 20 pages, 6 figures. arXiv admin note: substantial text overlap with arXiv:1309.326

    A new generalized Lindley distribution

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    In this paper, we present a new class of distributions called New Generalized Lindley Distribution(NGLD). This class of distributions contains several distributions such as gamma, exponential and Lindley as special cases. The hazard function, reverse hazard function, moments and moment generating function and inequality measures are are obtained. Moreover, we discuss the maximum likelihood estimation of this distribution. The usefulness of the new model is illustrated by means of two real data sets. We hope that the new distribution proposed here will serve as an alternative model to other models available in the literature for modelling positive real data in many areas. Keywords: Generalized Lindley Distribution; Gamma distribution, Maximum likelihood estimation; Moment generating function

    Beta Linear Failure Rate Geometric Distribution with Applications

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    This paper introduces the beta linear failure rate geometric (BLFRG) distribution, which contains a number of distributions including the exponentiated linear failure rate geometric, linear failure rate geometric, linear failure rate, exponential geometric, Rayleigh geometric, Rayleigh and exponential distributions as special cases. The model further generalizes the linear failure rate distribution. A comprehensive investigation of the model properties including moments, conditional moments, deviations, Lorenz and Bonferroni curves and entropy are presented. Estimates of model parameters are given. Real data examples are presented to illustrate the usefulness and applicability of the distribution

    Corrosion mechanism and bioactivity of borate glasses analogue to Hench’s bioglass

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    Bioactive borate glasses (from the system Na2O-CaO-B2O3-P2O5) and corresponding glass-ceramics as a new class of scaffold material were prepared by full replacement of SiO2 with B2O3 in Hench patented bioactive glass. The prepared samples were investigated by differential thermal analysis (DTA), Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analysis. The DTA data were used to find out the proper heat treatment temperatures for preparation of the appropriate glass-ceramics with high crystallinity. The prepared crystalline glass-ceramics derivatives were examined by XRD to identify the crystalline phases that were precipitated during controlled thermal treatment. The FTIR spectroscopy was used to justify the formation of hydroxyapatite as an indication of the bioactivity potential or activity of the studied ternary borate glasses or corresponding glass-ceramics after immersion in aqueous phosphate solution. The corrosion results are interpreted on the basis of suggested recent views on the corrosion mechanism of such modified borate glasses in relation to their composition and constitution

    The Gamma-Generalized Inverse Weibull Distribution with Applications to Pricing and Lifetime Data

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    A new distribution called the gamma-generalized inverse Weibull distribution which includes inverse exponential, inverse Rayleigh, inverse Weibull, Frechet, generalized inverse Weibull, gamma-exponentiated inverse exponential, exponentiated inverse exponential, Zografos and Balakrishnan-generalized inverse Weibull, Zografos and Balakrishnan-inverse Weibull, Zografos and Balakrishnan-generalized inverse exponential, Zografos and Balakrishnan-inverse exponential, Zografos and Balakrishnan-generalized inverse Rayleigh, Zografos and Balakrishnan-inverse Rayleigh, and Zografos and Balakrishnan-Fr\u27echet distributions as special cases is proposed and studied in detail. Some structural properties of this new distribution including density expansion, moments, Renyi entropy, distribution of the order statistics, moments of the order statistics and L-moments are presented. Maximum likelihood estimation technique is used to estimate the model parameters and applications to a real datasets to illustrate its usefulness are presented

    Concept mapping and conceptual change texts: a constructivist approach to address the misconceptions in nanoscale science and technology

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    Nanoscale Science and Technology (NST) is a rapidly evolving field with profound implications for various industries and our everyday lives. However, misconceptions among learners can hinder their ability to grasp the fundamental concepts of NST, thereby impeding their potential contributions to this advancing domain. Concept maps (CM) and conceptual change texts (CCT) are graphical and written representations of knowledge that enable learners to visualize relationships between concepts and assess the coherence of their understanding. In this pursuit, we engage with the concept of rehabilitation for misconceptions, viewing the learning process as a transformative journey akin to cognitive rehabilitation. Through this CM-CCT constructivist approach, learners are encouraged to engage in critical reflection, self-questioning, and peer discussions, which facilitate the identification of misconceptions. Moreover, CM-CCT provide a structured framework for presenting accurate information about NST, offering a clear depiction of the hierarchical and interconnected nature of nanoscale phenomena. The aim of this study was to evaluate the effectiveness of CM-CCT in correcting the misconceptions of undergraduate university students regarding nanotechnology and the taxonomy of nonmaterial. Prior to the implementation of the CM-CCT, an assessment of pre-existing knowledge of the students was performed through the structure of the observed learning outcomes (SOLO) taxonomy. A quasi-experimental research design was carried out. A total of 70 undergraduate university students, divided into two intact groups, were cross-examined for the study. Further, before and after the instructional tools, an achievement test based on nanotechnology and classification of nonmaterial was conducted, covering all six cognitive domains of the Bloom taxonomy of educational objectives. Data analysis revealed that the instructional tools based on constructivist approach had a statistically significant impact on students for elimination of their misconceptions about nanotechnology, nano science and classification of nonmaterial

    Prediction of mechanical and radiation parameters of glasses with high Bi2O3 concentration

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    This study aims to perform multidirectional characterizations on nuclear shielding efficiencies on some bismuth-based glasses. Accordingly, the γattenuation coefficients for xBi2O3-(75-x)B2O3–25Li2O (x = 0, 10, 20, 30, 40, 50, 60 the 70 mol%) were widely evaluated using simulations and theoretical methods. Linear attenuation coefficient (LAC) of the glasses was obtained by the Monte Carlo general-purpose simulation code FLUKA and compared with the XCOM database up to 15 MeV. Moreover, LAC values have been utilized to evaluate related parameters like mass attenuation coefficient (MAC), total molecular cross-section (σt), total atomic cross-section (σa), half-value layer (HVL), total electronic cross-section (σe), mean free path (MFP), effective atomic number (Zeff), and effective electron density (Neff). The results noted that the XCOM and FLUKA data of the shielding parameters are in great agreement. Relatively higher density (5.818 g/cm3), greater LAC, MAC, Zeff, and lower HVL, MFP values are achieved for 70Bi2O3-5B2O3–25Li2O glass. Accordingly, this glass sample is a better gamma shield. © 2021 The AuthorsTaif University Researchers Supporting Project number (TURSP-2020/45) Taif University, Taif, Saudi Arabia

    Isostructural second-order phase transition of b-Bi2O3 at high pressures: an experimental and theoretical study

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    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/jp507826jWe report a joint experimental and theoretical study of the structural and vibrational properties of synthetic sphaerobismoite (beta-Bi2O3) at high pressures in which room-temperature angle-dispersive X-ray diffraction (XRD) and Raman scattering measurements have been complemented with ab initio total energy and lattice dynamics calculations. Striking changes in Raman spectra were observed around 2 GPa, whereas X-ray diffraction measurements evidence no change in the tetragonal symmetry of the compound up to 20 GPa; however, a significant change exists in the compressibility when increasing pressure above 2 GPa. These features have been understood by means of theoretical calculations, which show that beta-Bi2O3 undergoes a pressure-induced isostructural phase transition near 2 GPa. In the new isostructural beta' phase, the Bi3+ and O2- environments become more regular than those in the original beta phase because of the strong decrease in the activity of the lone electron pair of Bi above 2 GPa. Raman measurements and theoretical calculations provide evidence of the second-order nature of the pressure-induced isostructural transition. Above 20 GPa, XRD measurements suggest a partial amorphization of the sample despite Raman measurements still show weak peaks, probably related to a new unknown phase which remains up to 27 GPa. On pressure release, XRD patterns and Raman spectra below 2 GPa correspond to elemental Bi-I, thus evidencing a pressure-induced decomposition of the sample during downstroke.Financial support from the Spanish Consolider Ingenio 2010 Program (MALTA Project CSD2007-00045) is acknowledged. This work was also supported by Brazilian Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) under Project 201050/2012-9, Spanish MICINN under Projects MAT2010-21270-004-01/03/04 and MAT2013-46649-C4-2/3/4-P, Spanish MINECO under Project CTQ2012-36253-C03-02, and from Vicerrectorado de Investigacion de la Universitat Politecnica de Valencia under Projects UPV2011-0914 PAID-05-11 and UPV2011-0966 PAID-06-11. Supercomputer time has been provided by the Red Espanola de Supercomputacion (RES) and the MALTA cluster. JAS. acknowledges Juan de la Cierva fellowship program for financial support.Pereira, ALJ.; Sans Tresserras, JÁ.; Vilaplana Cerda, RI.; Gomis, O.; Manjón Herrera, FJ.; Rodriguez-Hernandez, P.; Muñoz, A.... (2014). Isostructural second-order phase transition of b-Bi2O3 at high pressures: an experimental and theoretical study. Journal of Physical Chemistry C. 118(40):23189-23201. https://doi.org/10.1021/jp507826jS23189232011184
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