Vector potential methods

Vector potential and related methods, for the simulation of both inviscid and viscous flows over aerodynamic configurations, are briefly reviewed. The advantages and disadvantages of several formulations are discussed and alternate strategies are recommended. Scalar potential, modified potential, alternate formulations of Euler equations, least-squares formulation, variational principles, iterative techniques and related methods, and viscous flow simulation are discussed

Numerical solution of transonic full stream function equations in conservation form

The stream function equation in conservation form is solved iteratively based on the artificial compressibility method. The density is not a unique function of the mass flux. In order to avoid the ambiguity near the sonic line, the density is updated in terms of the velocity, which is obtained through a simple integration of a first order equation step by step in the flow field. Iteration algorithms and finite difference approximations are discussed and numerical results of both conservative and nonconservative calculations are presented

Cryptosporidiosis: From Prevention to Treatment, a Narrative Review

Cryptosporidiosis is a water- and food-borne zoonotic disease caused by the protozoon parasite of the genus Cryptosporidium. C. hominis and C. parvum are the main two species causing infections in humans and animals. The disease can be transmitted by the fecal–oral route as well as the respiratory route. The infective stage (sporulated oocysts) is resistant to different disinfectants including chlorine. Currently, no effective therapeutic drugs or vaccines are available to treat and control Cryptosporidium infection. To prevent cryptosporidiosis in humans and animals, we need to understand better how the disease is spread and transmitted, and how to interrupt its transmission cycle. This review focuses on understanding cryptosporidiosis, including its infective stage, pathogenesis, life cycle, genomics, epidemiology, previous outbreaks, source of the infection, transmission dynamics, host spectrum, risk factors and high-risk groups, the disease in animals and humans, diagnosis, treatment and control, and the prospect of an effective anti-Cryptosporidium vaccine. It also focuses on the role of the One Health approach in managing cryptosporidiosis at the animal–human–environmental interface. The summarized data in this review will help to tackle future Cryptosporidium infections in humans and animals and reduce the disease occurrence

Recent developments in finite element analysis for transonic airfoils

The prediction of aerodynamic forces in the transonic regime generally requires a flow field calculation to solve the governing non-linear mixed elliptic-hyperbolic partial differential equations. Finite difference techniques were developed to the point that design and analysis application are routine, and continual improvements are being made by various research groups. The principal limitation in extending finite difference methods to complex three-dimensional geometries is the construction of a suitable mesh system. Finite element techniques are attractive since their application to other problems have permitted irregular mesh elements to be employed. The purpose of this paper is to review the recent developments in the application of finite element methods to transonic flow problems and to report some recent results

A unified approach for numerical simulation of viscous compressible and incompressible flows over adiabatic and isothermal walls

A new formulation (including the choice of variables, their non-dimensionalization, and the form of the artificial viscosity) is proposed for the numerical solution of the full Navier-Stokes equations for compressible and incompressible flows with heat transfer. With the present approach, the same code can be used for constant as well as variable density flows. The changes of the density due to pressure and temperature variations are identified and it is shown that the low Mach number approximation is a special case. At zero Mach number, the density changes due to the temperature variation are accounted for, mainly through a body force term in the momentum equation. It is also shown that the Boussinesq approximation of the buoyancy effects in an incompressible flow is a special case. To demonstrate the new capability, three examples are tested. Flows in driven cavities with adiabatic and isothermal walls are simulated with the same code as well as incompressible and supersonic flows over a wall with and without a groove. Finally, viscous flow simulations of an oblique shock reflection from a flat plate are shown to be in good agreement with the solutions available in literature

Enhancement yield and fruit quality of Washington Navel orange by application of spraying potassium microencapsulated biodegradable polylactic acid

This research seeks to improve the fertilizer use efficiency, particularly potassium nutrient, and to minimize any possible dose losses. The improvement was applied by the use of foliar sprays by encapsulated potassium element into biodegradable polymer. The potassium polylactic acid microspheres (K-PLA) were characterized by Gel Permeation Chromatography (GPC) and Scanning Electron Microscope (SEM).  Piratical size and zeta potential measurements were investigated. Thermal behavior (TGA and DTA) was studied. In capsulation percentage of potassium into PLA microspheres was 4.5 W %. Cumulative release was estimated by inductive coupled plasma-atomic emission spectrometry (ICP-AES), the maximum cumulative release was 3.74 % after 12 hours. Washington Navel orange trees treated with uploaded potassium (K2O) and loaded potassium (K-PLA) or in their mixture (three times in the year) during two successive seasons 2015 and 2016 in private orchard located at El-Kalubia Governorate to evaluate the dual benefit (yield and fruit quality).  The results showed that, the sole treatments significantly increase yield and fruit quality than control (zero % K formulation). However, K-PLA can stabilize K and can significant improve yield and coloring percentage than uploaded K. Both treatments decrease juice acidity %. Whereas, increase content of total soluble solids and vitamin C especially K-PLA (100 %) and ascending order with applying formulations (75% K2O+ 25% K-PLA), (50% K2O+ 50% K-PLA) and (25% K2O+ 75% K-PLA). It can be recommendation, foliar spray of Washington Navel orange orchards by loaded potassium formulation is promising to improve the dual benefit, providing fertilizers and environmentally safe

Effectiveness of the antifungal black seed oil against powdery mildews of cucumber (Podosphaera xanthii) and barley (Blumeria graminis f.sp. hordei)

When cucumber and barley leaves were sprayed with 0.5% black seed oil (BSO), rapeseed oil (R oil) and parafine oil (P oil), disease severity of the powdery mildew of cucumber (Podosphaera xanthii) was reduced from 52% (control) to 7.7% (BSO), 18.6% (R oil) and 20% (P oil). Similarly the disease severity of barley powdery mildew (Blumeria graminis f.sp. hordei) was greatly reduced from 63.4% (control) to 9.4% (BSO), 16% (R oil) and 16.4% (P oil). Oils inhibited the conidial germination of cucumber and barley powdery mildews to 29-30.7, 35-38 and 37-41% respectively, as compared to control (58-65%). Furthermore, mycelial growth of the pathogen was severely restricted after application of BSO and other oils. Levels of hydrogen peroxide (H2O2) and superoxide (O2.-) as well as the activity of the antioxidant enzymes in the treated leaves with oils and untreated (control) were measured and determined. H2O2 and O2.-levels slightly increased, however some antioxidants are decreased such as dehydroascorbate reductase (DHAR) but other enzymes were increased such as ascorbate peroxidase (APX) and glutathione S transferase (GST). It can be concluded that the protective effect of oils against powdery mildews resulted mainly from the inhibition of conidial germination and suppression of the mycelial growth of the pathogens and there is slight activation of the host defence mechanisms. Therefore, it is important to giving more attention to BSO and other oils which have effectiveness against powdery mildew pathogens as an alternative control methods which safety and suitable for healthy and organic food production