Dynamical Analysis and Control Strategies for Capturing the Spread of COVID-19

In this paper, a study of preventive measures capable of curbing the spread of COVID 19 pandemic to avoid its second wave was carried out. The existence and uniqueness of the proposed mathematical model is assured, the basic reproduction number is established, the local and global stability of the disease free equilibrium are well obtained and the variational iteration method is applied to solve the mathematical model. Numerical simulation of the included control parameters are carried out. The obtained results and outcomes are presented graphically. It was revealed that enlightenment to vaccination awareness should be encouraged as vaccination is a good strategy of capturing the spread of the disease. Keywords: Covid-19, Basic Reproduction Number, Local stability, Global Stability, variational Iteration Metho

Effect of Al and Mg Doping on Optical Properties of ZnO Thin Films Prepared by Spin Coating

This paper investigated the influence of aluminum and magnesium doping on the optical and electrical properties of zinc oxide (ZnO) thin films for solar cell application. zinc acetate dehydrates was used as starting material. Aluminum chloride and tin chloride were added to each solution to serve as dopants. X-ray diffractions were analyzed by X-ray diffraction (XRD) which revealed crystalline and hexagonal wurtzite structure. All the films showed more than 80% transparency in the visible region. The optical band gap of undoped znO thin film was found to be 3.12ev while that of Al-doped and Mg-doped znO film was estimated to be 3.16eV and 3.26eV respectively. The resistivity of the films measured were 2.51×10–4Ω cm for Al-doped, 2.53×10–4Ω cm for mg-doped and 2.61×10-4Ω cm for undoped znO respectively. The quality of the films deposited in this work is a promising window layer component of a solar cell. The variation in the band gap observed in this work could be explained by Burstein–Moss effect which was fully explained in the discussion section of this work

On the Effects of Saturation Terms on A SEIR Epidemic Model with Infected and Susceptible Compartments

The importance of the saturation term in an SEIR (Susceptible, Exposed, Infected, and Recovered) epidemic model was examined in this article. To estimate the basic reproduction number (R0), examine the stabilities and run numerical simulations on the model, the next generation matrix, the Lyapunov function and Runge-Kutta techniques were used. The numerical simulation results reveal that, the saturation term has a significant influence in the model’s susceptible and infected compartments. However, as demonstrated by the simulation results, saturation term has a greater influence on vulnerable people than on infected people. As a result, greater sensitization programs through seminars, media, and awareness will be more beneficial to the vulnerable class than the afflicted class during disease eradication

Three-dimensional cubic ordered mesoporous carbon (CMK-8) as highly efficient stable Pd electro-catalyst support for formic acid oxidation

In this work, Pd nanoparticles were supported on two types of three-dimensional cubic highly ordered mesoporous carbon (CMK-8) by the sodium borohydride reduction method and the activity of the Pd/CMK-8 electro-catalysts towards formic acid oxidation was evaluated and compared with that of commercial Pd/C (E-TEK) catalyst. The catalysts were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), cyclic voltammetry, and chronoamperometry. Cyclic voltammetry revealed Pd/CMK-8 with larger pores as being the most electroactive with a mass specific activity (mA mgPd−1) of 486.4 that exceeded not only that of the Pd/C (E-TEK) (386.5 mA mgPd−1) but also that of recently reported Pd/CNT (200 mA mgPd−1), Pd/Graphene (210 mA mgPd−1) and Pd/Vulcan XC 72 (193 mA mgPd−1). As demonstrated with chronoamperometry, the larger pore Pd/CMK-8 also proved to be the most stable catalyst. This exceptional performance can be ascribed to the very high surface area and Ia3d symmetry that yields a relatively isotropic graphitized structure with a high conductivity. In addition, the open framework of the 3-D bicontinous channels and highly ordered mesopores allows for an advanced mass transfer characteristics. The results show that CMK-8 support would significantly improve the power output and stability of Pd-based electro-catalysts for formic acid oxidation

Immobilization of alpha- Amylase on Mesoporous Silica KIT-6 and Palm Wood Chips for Starch Hydrolysis

?-Amylase was immobilized on highly ordered mesoporous silica KIT-6 and palm wood chips (PWC) by physical adsorption. The activity of the immobilized enzyme for starch hydrolysis was investigated at different solution pH and enzyme concentration for both supports. The thermal stability of the immobilized enzyme was also investigated for both supports. The result indicates that the maximum activity, in terms of glucose concentration, for both supports was observed close to the isoelectric point (PI = 7.00) of the enzyme. Activity increased with increasing concentration of the enzyme solution for both supports. The glucose to support ratio of 48 was obtained for KIT-6 compared to a value of 0.6 obtained for PWC. KIT-6 shows superior thermal stability. The exceptional performance of KIT-6 relative to PWC can be ascribed to its high adsorptive capacity as well as its excellent mass transfer characteristics arising from its very high surface area, large pore diameter and highly ordered pores. Keywords: Mesoporous silica, KIT-6, Palm wood chips, Enzyme immobilization, ?-amylase, Starch hydrolysi

International Journal of Pure and Applied Sciences and Technology Correlation between the Power Output and Exposure to Sunlight of a Solar Panel

Abstract: The degree of dependence of power delivered by a solar panel on input solar irradiance was examined with a 10watt polycrystalline silicon (S