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Effects of Radiation Absorption and Mass Transfer on the Free Convective Flow Passed a Vertical Flat Plate through a Porous Medium in an Aligned Magnetic Field
Get PDFThis article analyses the effects of radiation absorption and mass transfer on the steady free convective flow of a viscous, incompressible and electrically conducting fluid past an infinite vertical flat plate through a porous medium with an aligned magnetic field. Analytical solutions for concentration, temperature, and velocity are obtained by solving the governing equations in two cases namely (i) when the plate is at uniform temperature and concentration and (ii) when the plate is at constant heat and mass flux. Further the rate of mass transfer in terms of the Sherwood number, rate of heat transfer in terms of Nusselt number and skin friction in terms of shear stress are also derived. The effects of various flow parameters on concentration, temperature, velocity, Sherwood number, Nusselt number and skin-friction affecting the flow field are discussed and analyzed
Modelling the Flow of Aqueous Humor in Schlemm’s Canal in the Eye
Get PDFA simple mathematical model for the transient flow of aqueous humor in the canal of Schlemm is developed to investigate the acceleration effects of a sudden elevation in the intraocular pressure on the flow characteristics of the aqueous humor in the canal. The model treats a canal segment as a tube of elliptic cross-section. Exact analytical solution to the model is obtained using separation of variables method. The effects of some important model parameters on the maximum and minimum shear stresses exerted on the Schlemm’s canal epithelial cells (wall) by flowing aqueous humor are investigated for the steady-state flow
Mechanism of 1-(1-propylsulfonic)-3-methylimidazolium chloride catalyzed transformation of d-glucose to 5-hydroxymethylfurfural in DMSO: An NMR study
No full textThe conversion of d-glucose to 5-hydroxymethylfurfural (HMF) in the presence of 5.48 mol % 1-(1-propylsulfonic)-3-methylimidazolium chloride acidic ionic liquid catalyst in DMSO at 150 C was studied using 1H, 13C NMR, and visible spectroscopy. The HMF yield rapidly increases in the first 100 min of reaction, however yield drops beyond 100 min and levels off to a maximum yield of about 15.7% around 600 min. The visible spectroscopy study of the reaction mixture suggests that rate of HMF formation slows down after 100 min due to increase in the rate of humin formation after first 100 min. A mechanism has been proposed and key intermediates in the pathway could be identified by studying the 13C NMR spectra of acidic ionic liquid catalyzed transformations of C-1 and C-2 13C labeled d-glucose under identical conditions. The proposed mechanism involves the isomerization of d-glucose to d-fructose via the complexation of the open chain sugar with the imidazolium cation of the acidic ionic liquid catalyst. © 2014 Elsevier Ltd. All rights reserved
Linear size-structured population models with spacial diffusion and optimal harvesting problems
No full textWe first investigate linear size-structured population models with spacial diffusion. Existence of a unique mild solution is established. Then we consider a harvesting problem for linear size-structured models with diffusion and show the existence of an optimal harvesting effort to maximize the total price or total harvest. © EDP Sciences, 2014
Analysis and control of switched linear systems via dwell-time min-switching
No full textThis paper addresses analysis and switching control problems of switched linear systems. To this end, a mixed time-driven and state-dependent switching strategy is proposed. It guarantees an average dwell time even when all subsystems are unstable. The switching rule and its associated switching output feedback controllers are designed to stabilize the switched system and satisfy a weighted L2 gain performance. The proposed analysis and switching control approach could refrain frequent switches commonly observed in min-switching based designs. The effectiveness of the proposed approach has been illustrated through a spherical inverted pendulum example. © 2014 Elsevier B.V. All rights reserved
Climate change impacts on agriculture and their effective communication by extension agents
No full textAgriculture is an important sector of the U.S. economy, contributing at least $200 billion to the economy each year. It is considered to be one of the sectors most vulnerable to climate change and represents a key sector for international trade. Climate change is a global problem with widespread effects and implications. This phenomenon could make it more difficult to grow crops, raise animals, and catch fish in the same ways and same places as in the past. Therefore, it is critical that climate change messages are communicated effectively by Extension agents to farmers and the farming community. © 2014 Extension Journal Inc
Fabrication and characterization of polycaprolactone (PCL)/gelatin electrospun fibers
No full textOver the past few decades, there has been considerable interest in developing electrospun fibers by using electrospinning technique for various applications. Polymer blending is one of the most effective methods in providing desired properties. In this study, synthetic polymer polycaprolactone (PCL) was blended together with natural polymer gelatin where both of them have different properties. It is done by using electrospinning technique. 10%w/v and 14%w/v PCL/gelatin electrospun fibers were successfully electrospun with different weight ratio. Processing parameters were set constant in this study and only solution parameters were altered. The optimized electrospun fiber formed was 14%w/v PCL/gelatin 70:30 with average fiber diameter of 246.30 nm. No beaded fiber was formed in this scanning electron microscope (SEM) image. The result obtained also showed that by increasing the overall polymeric concentration of PCL/gelatin, average fiber diameter decreases. Fiber diameter was also found decreasing with the increase of the concentration of gelatin in the same concentratoin of PCL/gelatin blended electrospun fiber. Blending of PCL and gelatin in different weight ratio had provided different properties of electrospun fibers. It is believed that blended electrospun fibers can be used for biomedical applications. © (2014) Trans Tech Publications, Switzerland
Applied research of convertible wind-solar hybrid system on Matlab
No full textThis paper designed the wind-solar hybrid electricity generation system, it might offer users reliable power supply when the climate and other factors change. The system has a variety of operation modes, can be either manually or automatically transforms. Each mode can be selected manually switching storage batteries to achieve the reliable power supply and prolong the battery service life. Through Matlab simulation analysis, the feasibility of the control system has been verified. Simulation results show that the system output stability, it can satisfy user demand
Cross-linking of bovine and caprine caseins by microbial transglutaminase and their use as microencapsulating agents for n-3 fatty acids
No full textBovine and caprine caseins were cross-linked with microbial transglutaminase (mTG). The mTG-cross-linked bovine or caprine casein dispersion, mixed with 14.5% maltodextrin (DE = 40), was used to prepare emulsions with 10.5% algae oil. Oxidative stability of emulsions was evaluated by peroxide values (PVs) and anisidine values. Adding liposoluble rosemary extract rich in carnosic acid and δ-tocopherol lowered the formation of hydroperoxides and their subsequent decomposition products in emulsions. Emulsions stabilised with liposoluble rosemary extract rich in carnosic acid and δ-tocopherol were spray-dried at 180/95 °C. Algae oil microencapsulated with mTG-cross-linked bovine casein reduced PV by ≈ 34%, while the algae oil microencapsulated with mTG-cross-linked caprine casein with low levels of αs1-casein reduced PV by ≈ 42% at 4 weeks of storage at 30 °C. The investigation suggests that liposoluble rosemary extract rich in carnosic acid and δ-tocopherol effectively protected algae oil during the coating process with mTG-cross-linked bovine and caprine caseins. The above results clearly indicated that the choice of milk caseins (bovine vs. caprine) cross-linked with mTG impacts the oxidative stability of spray-dried algae oil emulsions (microcapsules) enriched with n-3 fatty acids. © 2014 The Authors
Panther - March 2014 - Vol. XCIV No. 16
Get PDFhttps://digitalcommons.pvamu.edu/pv-panther-newspapers/1401/thumbnail.jp