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An Optimal Control Problem Solution for Chemical Reactor
Get PDFIn this paper, we describe one of the solutions of a nonlinear optimal control problem for a chemical reactor. A solution on finding a chemical reactor’s optimal temperature regime for having a maximum concentration of final product is presented. The optimal control has been found by immersion method for boundary value problem with a phase and control restrictions. This method is reducing the original boundary value problem to a special optimal control problem, using the general solution of the Fredholm integral equation of the first kind. With this method\u27s solution had been created a software for the problem calculations. Analysis of the method is presented
Significance of Coriolis Force on Eyring-Powell Flow Over A Rotating Non-uniform Surface
Get PDFCoriolis force plays significant roles in natural phenomena such as atmospheric dynamics, weather patterns, etc. Meanwhile, to circumvent the unreliability of Newtonian law for flows involving varying speed, Eyring-Powell fluid equations are used in computational fluid dynamics. This paper unravels the significance of Coriolis force on Eyring-Powell fluid over the rotating upper horizontal surface of a paraboloid of revolution. Relevant body forces are included in the Navier-Stokes equations to model the flow of non-Newtonian Eyring-Powell fluid under the influence of Coriolis force. Using similarity transformation, the governing equations are nondimensionalized, thereby transforming the nonlinear partial differential equations to a system of boundary value nonlinear ordinary differential equations. The shooting technique is adopted to convert the boundary value problem to an initial value problem, which is in turn solved using the Runge-Kutta-Gill Scheme. At low Coriolis force, temperature profiles increase as Eyring-Powell parameter increases, whereas at high Coriolis force, temperature profiles decrease with increasing Eyring-Powell parameter
COVID-19 Modeling with Caution in Relaxing Control Measures And Possibilities of Several Peaks in Cameroon
Get PDFWe construct a new model for the comprehension of the Covid-19 dynamics in Cameroon. We present the basic reproduction number and perform some numerical analysis on the possible outcomes of the epidemic. The major results are the possibilities to have several peaks before the end of the first outbreak for an uniform strategy, and the danger to have a severe peak after the adoption of a careless strategy of barrier anti-Covid-19 measures that follow a good containment period
Thermal-Diffusion and Diffusion-Thermo Effects on Heat and Mass Transfer in Chemically Reacting MHD Casson Nanofluid with Viscous Dissipation
Get PDFIn this paper, we examined the combined effects of dissipation and chemical reaction in Casson nanofluid motion through a vertical porous plate subjected to the magnetic field effect placed perpendicular to the flow channel. The physical problem is modeled using partial differential equations (PDEs). These sets of PDEs, with suitable similarity transformations, are simplified into ordinary differential equations (ODEs). Collocation technique with legendary basis function is utilized in solving the transformed equations. The numerical analysis on velocity, concentration, and temperature are plotted and tabled for different flow parameters. Our findings show that by raising the Casson parameter close to infinity, the behavior of Casson fluid obeys the law of viscosity. Conversion of energy via the work done by the fluid molecules, influences both dimensionless velocity and temperature profiles significantly, while the mass flux hikes the concentration profile. The heat generated by the intermolecular reaction of fluid particles resulted in a large amount of heat produced in the flow field
An eco-benign synthesis of silver nanoparticles using Aegle marmelos L. bark extract and evaluation of their DNA cleavage, DNA binding, antioxidant and antibacterial activity
No full textThe present study demonstrates green chemistry assisted synthesis of silver nanoparticles (B-AgNPs) in aqueous medium employing bark extract of Aegle marmelos L., their characterization and biological applications. B-AgNPs were synthesized at 70 °C with 0.005 M AgNO3 was reduced with 5.0 mL of bark extract for 20 min and monitored with UV-Vis spectrum. The size, charge, stability, and polydispersity index of B-AgNPs were determined using dynamic light scattering (DLS) and zeta potential analysis. Scanning electron microscope and high resolution transmission electron microscopy images showed that spherical-shaped BAgNPs were formed with average size of 20 nm along with a hydrodynamic diameter ranging from 5 to 100 nm in two subpopulations as evaluated by DLS analysis. Fourier transmission infrared spectrum ascertain the functional groups and purity while energy dispersive X-ray spectroscopy study confirms the elemental composition of BAgNP. B-AgNPs remarkably exhibit DNA cleavage activity against pUC19 and binding activity with CT-DNA. The growth inhibition potential of BAgNPs against Staphylococcus aureus, Escherichia Coli, and Pseudomonas aeruginosa bacterial strains was tested and they exhibited minimum inhibitory concentration value 10 μM against E. coli lower than the plant extract. DPPH assay in different concentrations of BAgNPs revealed the antioxidant potential between 41.3% and 90.2%
Adjustable Internal Shading for Home Office Daylighting in Tropical Climates
No full textHome-based workspaces have considerably increased all over the world. Besides, the recent outbreak of the COVID-19 disease forced many people to work from their homes. However, existing residential apartment buildings (ERABs) had been designed for accommodation but not for office works. Low-quality visual environments in ERABs, which have no shading controls on their windows, are evident in tropical climates with extremely high solar radiation. Thus, interior retrofit is significant to provide visual comfort for users in ERABs with low flexibility for modification of their facades. Different interior design variables were simulated by the Radiance-based program to analyse daylighting in a closed-plan room. Before the simulation experiments, field measurement of daylight was performed under a tropical sky to validate the results, and the findings revealed significant Pearson correlations. This paper showed that ERABs are confronting extremely high indoor daylight quantity, up to 10,228 lx, and low quality with intolerable glare. An adjustable model of internal shading, including an integrated Venetian blind with a horizontal light shelf and the window films, was proposed to improve quantitative and qualitative performances of daylighting in tropical regions. This dynamic model could be adjusted to various positions based on daylighting conditions in the buildings. By comparing the simulation results of this model with the base model, indoor illuminance levels could successfully reduce from 32% to 86%; Illuminance Uniformity Ratio (IUR) and Target Daylight Illuminance (TDI) significantly improved up to 180% and 300%, respectively; Daylight Glare Probability (DGP) and CIE Glare Index (CGI) changed from intolerable to imperceptible status. Accordingly, the proposed model can considerably improve daylight quantity and quality in the test room during different times. This study concludes that the dynamic model of internal shadings could provide efficient daylighting, by decreasing the extremely high indoor illuminance and glare in the ERABs in tropical climates
Radiosynthesis of 5-[\u3csup\u3e18\u3c/sup\u3ef]fluoro-1,2,3-triazoles through aqueous iodine–[\u3csup\u3e18\u3c/sup\u3ef]fluorine exchange reaction
No full textIn this report, a simple and efficient process to achieve fluorine-18-labeled 1,2,3-triazole is reported. The heteroaromatic radiofluorination was successfully achieved through an iodine– fluorine-18 exchange in an aqueous medium requiring only trace amounts of base and no azeotropic drying of fluorine-18. This methodology was optimized on a model reaction and further validated on multiple 1,2,3-triazole substrates with 18–60% radiochemical conversions. Using this strategy—the radiosynthesis of a triazole-based thiamin analogue—a potential positron emission tomography (PET) probe for imaging thiamin-dependent enzymes was synthesized with 10–16% isolated radiochemical yield (RCY) in 40 min (uncorrected, n \u3e 5)
Pulsed led-lighting as an alternative energy savings technique for vertical farms and plant factories
No full textDifferent strategies are reported in the literature for energy saving in Closed Plant Production Systems (CPPS). However, not reliable evidences about energy consumption with the use of pulsed LED light technique in lighting system available in Plant Factory and Vertical Farm. In this work, three key points to determine the effects of pulsed LED light versus continuous LED light are presented: (1) A mathematical model and its practical application for stabilizing the energy equivalence using LED light in continuous and pulsed mode in different light treatments. (2) The quantum efficiency of the photosystem II was used to determine positive and/or negative effects of the light operating mode (continuous or pulsed) on chili pepper plants (Capsicum annuum var. Serrano). (3) Evaluation of energy consumption with both operation modes using ten recipes from the literature to grow plants applied in Closed Plant Production Systems, different Photosynthetic Photon Flux Density at 50, 110, and 180 µmol m−2 s−1, Frequencies at 100, 500, and 1000 Hz, and Duty Cycles of 40, 50, 60, 70, 80, and 90%. The results show no significant statistical differences between the operation modes (continuous and pulsed LED light). For each light recipe analyzed, a pulsed frequency and a duty cycle were obtained, achieving significant energy savings in every light intensity. The results can be useful guide for real-life applications in CPPS
PV Solar Technology for Energy Cost and Emissions Reduction in Rural Area
No full textThe world in recent times has leaned towards increased use of renewable energy which is because of spiking cost of fossil fuels, environmental impact etc. Solar energy from the sun has seen a lot of application recently mainly due to its availability and scalability. Sunlight is composed of photons-packets of solar energy. When photons strike a photovoltaic (PV) cell, they may be reflected or absorbed, or they may pass right through. The absorbed photons generate electricity. The energy of a photon is transferred to an electron in an atom of the semiconductor device. An array of solar cells converts solar energy into a usable amount of Direct Current (DC) electricity. This paper presents a PV solar farm system using electricity usage data obtained from a utility provider in a rural area (Prairie View) in Texas, while examining factors that may affect solar energy integration in the area. The results of the power and voltages generated at different temperatures are analyzed and compared