Journal of Mathematical and Fundamental Sciences
Not a member yet
737 research outputs found
Sort by
A New Hybrid Approach for Solving Large-scale Monotone Nonlinear Equations
Get PDFIn this paper, a new hybrid conjugate gradient method for solving monotone nonlinear equations is introduced. The scheme is a combination of the Fletcher-Reeves (FR) and Polak-Ribiére-Polyak (PRP) conjugate gradient methods with the Solodov and Svaiter projection strategy. Using suitable assumptions, the global convergence of the scheme with monotone line search is provided. Lastly, a numerical experiment was used to enumerate the suitability of the proposed scheme for large-scale problems
One-sided Downward Control Chart for Monitoring the Multivariate Coefficient of Variation with VSSI Strategy
Get PDFIn recent years, control charts monitoring the coefficient of variation (CV), denoted as the ratio of the variance to the mean, is attracting significant attention due to its ability to monitor processes in which the process mean and process variance are not independent of each other. However, very few studies have been done on charts to monitor downward process shifts, which is important since downward process shifts show process improvement. In view of the importance of today's competitive manufacturing environment, this paper proposes a one-sided chart to monitor the downward multivariate CV (MCV) with variable sample size and sampling interval (VSSI), i.e. the VSSID MCV chart. This paper monitors the MCV as most industrial processes simultaneously monitor at least two or more quality characteristics, while the VSSI feature is incorporated, as it is shown that this feature brings about a significant improvement of the chart. A Markov chain approach was adopted for designing a performance measure of the proposed chart. The numerical comparison revealed that the proposed chart outperformed existing MCV charts. The implementation of the VSSID MCV chart is illustrated with an example
Metal-Organic Frameworks Based on Zinc(II) and Benzene-1,3,5-Tricarboxylate Modified Graphite: Fabrication and Application as an Anode Material in Lithium-Ion Batteries
Get PDFThis research was aimed at synthesizing metal-organic frameworks (MOFs) based on zinc(II) and a benzene-1,3,5-tricarboxylate (BTC) linker in combination with graphite as anode material in lithium-ion batteries. The MOFs were prepared using sonochemical and solvothermal methods, which led to different materials: [Zn3(BTC)2·12H2O] (MOF 1) and [Zn(BTC)·H2O·3DMF] (MOF 2). The produced materials were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric/differential thermal analysis (TG/DTA), and a battery analyzer. Refinement of the XRD data was performed using the Rietica and Le Bail method. Sharp and intense peaks indicated that the materials had a high degree of crystallinity. The morphology of the materials as analyzed by SEM was cubic, with an average crystal size of 8.377 ± 4.276 µm for MOF 1 and a larger size of 16.351 ± 3.683 µm for MOF 2. MOF 1 was thermally stable up to 378.7 °C while MOF 2 remained stable up to 341.8 °C, as demonstrated by thermogravimetric analysis. The employment of the synthesized materials as anode in a lithium ion battery was proved to yield higher specific capacity and cycle stability compared to those using a graphite anode. The lithium-ion battery with 5 wt% MOF 1 exhibited the highest performance with an efficiency of 97.28%, and charge and discharge specific capacities of 123.792 and 120.421 mAh/g, respectively
Continuous-Like Linear Operators on Bilinear Spaces
Get PDFThis paper introduces continuous-like linear operators on bilinear spaces as a generalization of continuous linear operators on Hilbert spaces. It is well known that the existence of the adjoint of a linear operator on a Hilbert space is equivalent to the operator being continuous. In this paper, this result is extended to the class of linear operators on bilinear spaces. It is shown that the existence of the adjoint of a linear operator on a bilinear space is guaranteed if and only if the operator is continuous-like
Spectral Analysis of Proton-Irradiated Natural MoO3 Relevant for Technetium-99m Radionuclide Production
No full textDue to the declining number of available nuclear reactors capable of Tc-99m production and tight regulations related to uranium enrichment, cyclotron-based Tc-99m production has recently been suggested as a new method to help ease Tc-99m supply shortages. In this investigation, a solid natural MoO3 target was irradiated using 11-MeV proton beams at variable proton doses. The proton doses were varied by varying the irradiation time while keeping the proton beam current constant at 20 µA. At the end of the bombardment, the post-irradiated solid MoO3 targets were analyzed for their radioactive contents using a portable gamma-ray spectroscopy system. The analysis was also performed for the post-irradiated targets after dissolving the solid MoO3 in a 6M NaOH solution. The experimental results indicated that as much as 75.71% of Tc-99m radioactivity was directly generated via a 100Mo(p,2n)99mTc nuclear reaction, while the rest of the Tc-99m radioactivity was a result of a 98Mo(n,γ)99Mo→99mTc nuclear reaction. Apart from Tc-99m and Mo-99 radionuclides, some other radionuclides such as N-13, Tc-96, and Nb-96 were also recorded following temporal observation of the NaOH-dissolved MoO3. These experimental results open up the possibility of direct production of Tc-99m using a proton-accelerating cyclotron
A New Type of Coincidence and Common Fixed-Point Theorems for Modified ð-Admissible ð©-Contraction Via Simulation Function
Get PDFIn this manuscript, we introduce the concept of modified α-admissible contraction with the help of a simulation function and use this concept to establish some coincidence and common fixed-point theorems in metric space. An illustrative example that yields the main result is given. Also, several existing results within the frame of metric space are established. The main theorem was applied to derive the coincidence and common fixed-point results for α-admissible ð’µ-contraction