Browsing Mathematics, Statistics & Physics by Title
Now showing items 349-368 of 715
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The Influence of Cation Substitution on the Magnetic Behaviour of Magnesium Ferrite
( WILEY-VCH Verlag GmbH & Co. , 1989 , Article)New polycrystalline specimens of the ferrites Mg1.5Fe1Si0.5O4, Mg1.5Fe1Ge0.5O4, Mg1.5Fe1Ti0.5O4 and Mg1.66Fe1Sb0.33O4 have been prepared and studied by nuclear gamma ray resonance technique, over a wide temperature range. ... -
Instability of Langmuir-beam waves: Kappa-distributed electrons
( American Institute of Physics Inc. , 2023 , Article)In space plasmas, electron populations exhibit non-equilibrium velocity distributions with high-energy tails that are reproduced by the Kappa power-laws and contrast with the Maxwellian distributions often used in theoretical ... -
Interval Estimation in Lifetime Distributions Using Progressively Type II Censored Data
( World Scientific , 2022 , Article)In this paper, we developed a method for constructing confidence intervals for the parameters of lifetime distributions based on progressively type II censored data. The method produces closed form expressions for the ... -
Interval estimation of quantile difference in the two-parameter exponential distributions
( ASTM International , 2018 , Article)We consider the interval estimation of the difference between the quantiles of two random variables with independent two-parameter exponential distributions based on Type II censored data. We derive asymptotic intervals ... -
Interval estimation of the stress-strength reliability in the two-parameter exponential distribution based on records
( Taylor and Francis Ltd. , 2014 , Article)We consider interval estimation of the stress-strength reliability in the two-parameter exponential distribution based on records. We constructed Bayesian intervals, Bootstrap intervals and intervals using the generalized ... -
Invariant characterization of scalar third-order ODEs that admit the maximal point symmetry Lie algebra
( John Wiley and Sons Ltd , 2018 , Article)The Cartan equivalence method is used to deduce an invariant characterization of the scalar third-order ordinary differential equation u"' = f(x, u, u', u"), which admits the maximal 7-dimensional point symmetry Lie algebra. ... -
Invariant characterization of third-order ordinary differential equations u''=f(x,u,u',u) with five-dimensional point symmetry group
( Elsevier B.V. , 2019 , Article)The Cartan equivalence method is applied to provide an invariant characterization of the third-order ordinary differential equation u''=f(x,u,u',u') which admits a five-dimensional point symmetry Lie algebra. The invariant ... -
Invariant solutions of the Wave equation on static spherically symmetric spacetimes admitting G7 isometry algebra
( MDPIAG , 2018 , Article)Algorithms to construct the optimal systems of dimension of at most three of Lie algebras are given. These algorithms are applied to determine the Lie algebra structure and optimal systems of the symmetries of the wave ... -
Invariants of third‐order ordinary differential equations y′′′=f(x,y,y′,y′′) via point transformations
( John Wiley and Sons Ltd , 2016 , Article)A new systematic method to find the relative invariant differentiation operators is developed. We incorporate this new approach with Lie's infinitesimal method to study the general class y′′′ = f(x, y, y′, y′′) under general ... -
Inverse Adaptive Cluster Sampling with Unequal Selection Probabilities: Case Studies on Crab Holes and Arsenic Pollution
( Wiley Publishing Asia Pty Ltd. , 2015 , Article)Adaptive cluster sampling is an efficient method of estimating the parameters of rare and clustered populations. The method mimics how biologists would like to collect data in the field by targeting survey effort to localised ... -
Investigating the individual interests of undergraduate students in STEM disciplines
( Frontiers Media SA , 2024 , Article)Despite massive investments in the education sector to empower youth in Qatar, a vital concern remains to retain students in science, technology, engineering, and mathematics (STEM) disciplines at the undergraduate level. ... -
Investigation of NH3 adsorption on noble metal modified MoSe2
( Elsevier , 2022 , Article)Gas pollutants represent hazard for the quality of the ambient environment, thus, the development of sensitive and selective gas sensors is essential to monitor and maintain its decent quality. The adsorption of NH3 gas ... -
Investigation of optical and electrical properties of Cobalt-doped Ge-Sb-S thin film
( Elsevier B.V. , 2019 , Article)Amorphous Germanium Antimony Sulphide (Ge-Sb-S) doped with Cobalt (Co) have been deposited on glass substrates by thermal evaporation technique on a glass substrate. The films deposited onto glass substrates are characterized ... -
Investigation of phase transformation for ferrite-austenite structure in stainless steel thin films
( Elsevier B.V. , 2016 , Article)In this work we report on phase transformation of 304 stainless steel thin films due to heat treatment. Ex-situ annealing was applied for evaporated 304 stainless steel thin films inside an ultra-high vacuum chamber with ... -
Investigation of Proton Diffusion Coefficient for PbO2 Prepared from Intermediate Oxides
( Pleiades Publishing , 2019 , Article)Lead dioxide was extracted from used batteries, and used to synthesize the following intermediate oxides by heating at different temperatures: Pb12O19, Pb12O17, and Pb3O4. Each of the prepared intermediate oxide was subject ... -
Investigation on inlet obstruction in transitional flow regime: Heat transfer augmentation and pressure drop analysis
( Elsevier , 2022 , Article)Thermohydraulic characteristics of air as the working medium in a circular heated channel fitted with inlet obstruction (ribbed prism) at the inlet is carried out experimentally for transitional flow regime. The ribbed ... -
Investigations of He <sup>+</sup> implantation and subsequent annealing effects in InP
( Elsevier , 2006 , Article)The influence of 70 keV He + ion implantation and subsequent annealing of Cz-indium phosphide (InP) samples has been investigated using a slow positron beam-based Doppler broadening spectrometer. Three samples with ion ... -
Ion beam modification of surface properties of polyethylene
( Elsevier , 2003 , Conference Paper)Improvement of polymer tribological properties is an essential issue for their application when used as parts of machines or artificial human joints. Ion implantation is a very promising technique in this respect. This ... -
Ion impact induced ionization/fragmentation dynamics of rare gas Dimers
( IOP Publishing , 2013 , Conference Paper)We have measured the ionization and fragmentation of Helium, Neon and Argon Dimers induced by ion impact and observed two different pathways, the sequential ionization on each atom and the interatomic Cou-lombic decay. © ... -
Ion-impact-induced interatomic Coulombic decay in neon and argon dimers
( American Physical Society , 2013 , Article)We investigate the contribution of interatomic Coulombic decay induced by ion impact in neon and argon dimers (Ne2 and Ar2) to the production of low-energy electrons. Our experiments cover a broad range of perturbation ...