Nonlinear TE Electromagnetic Surface Waves in a Ferrite Layered Structure

Characteristics of TE electromagnetic surface waves propagating in a nonlinear dielectric film bounded by a ferrite cover are examined theoretically. A dispersion relation based on Jacobian Elliptic Functions is derived, which describes the behaviour of the nonreciprocal nonlinear waves. ) TE ( . ) Jacobian Function (

Attenuation in Rectangular Waveguides with Finite Conductivity Walls

We present a fundamental and accurate approach to compute the attenuation of electromagnetic waves propagating in rectangular waveguides with finite conductivity walls. The wavenumbers kx and ky in the x and y directions respectively, are obtained as roots of a set of transcendental equations derived by matching the tangential component of the electric field (E) and the magnetic field (H) at the surface of the waveguide walls. The electrical properties of the wall material are determined by the complex permittivity ε, permeability μ, and conductivity σ. We have examined the validity of our model by carrying out measurements on the loss arising from the fundamental TE10 mode near the cutoff frequency. We also found good agreement between our results and those obtained by others including Papadopoulos’ perturbation method across a wide range of frequencies, in particular in the vicinity of cutoff. In the presence of degenerate modes however, our method gives higher losses, which we attribute to the coupling between modes as a result of dispersion

In vitro Transdermal Permeation of Fenoterol Hydrobromide

The aim of this study was to determine if transdermal penetration of fenoterol, a β-agonist drug, could be enhanced and controlled by formulation modification and formulation of transdermal patches. Pre-formulation studies were performed to determine the feasibility of a transdermal dosage form of fenoterol. Penetration of fenoterol was determined using the hairless guinea pig skin with unjacketed Franz diffusion cell. Transdermal patches were formulated using drug in-adhesive technique. Several enhancers were investigated for fenoterol skin penetration. Transcutol–oleic acid co-solvent gives the highest drug flux among all tested liquid formulations. Pretreatment of the skin with oleic acid 2 h before patch application significantly increases drug diffusion. Cis-oleic acid gives best results compared to oleic acid. Azone derivative (1-dodecyl-2-pyrrolidinone) gives the highest drug diffusion amongst all tested enhancers. Results of this study show the feasibility of using fenoterol formulated in transdermal delivery system in the treatment of chronic asthma to improve patient compliance, bioavailability and reduce the inter-subject variability

ROLE OF TESTOSTERONE IN THE TREATMENT OF ED

Hypogonadism may play a significant role in the pathophysiology of erectile dysfunction (ED). A threshold level of testosterone may be necessary for normal erectile function. Testosterone replacement therapy is indicated in hypogonadal patients and is beneficial in patients with ED and hypogonadism. Monotherapy with testosterone for ED is of limited effectiveness and may be most promising in young patients with hypogonadism and without vascular risk factors for ED. A number of laboratory and human studies have shown the combination of testosterone and other ED treatments, such as phosphodiesterase type 5 (PDE5) inhibitors, to be beneficial in patients with ED and hypogonadism, who fail PDE5 inhibitor therapy alone. There is increasing evidence that combination therapy is effective in treating the symptoms of ED in patients for whom treatment failed with testosterone or PDE5 inhibitors alone. Testosterone replacement therapy has potentially evolved from a monotherapy for ED in cases of low testosterone, to a combination therapy with PDE5 inhibitors. Screening for hypogonadism may be useful in men with ED who fail prior PDE5 inhibitors, especially in populations at risk for hypogonadism such as type 2 diabetes and the metabolic syndrome

Synthesis and Characterization of Gold Nanoparticles Functionalized with Electropolymerizable or Optically Switchable π-Conjugated Systems

International audienc

Hepatoprotective Effect of Captopril on Liver Toxicity Induced by High and Low Dose of Paracetamol in Rats:Histological Study

Many patients may administered medications like captopril (ACE inhibitor) for treatment of chronic diseases and may also take Paracetamol as an Over The Counter (OTC) drug which may interact with captopril. Therefore, the aim of this study is to evaluate of the hepatoprotective effect of captopril on liver toxicity induced by low and high dose of paracetamol in rats. This study was conducted in two phases: first study for low dose of paracetamol (300 mg/kg); animals were divided into 4 groups of 6 rats each (n = 6); all groups were treated orally either 0.9 % Normal Saline (NS), captopril 20 mg/kg, paracetamol 300 mg/kg or captopril 20 mg/kg plus paracetamol 300 mg/kg for 10 consecutive days. Second study for single high dose of paracetamol (3000 mg/kg); animals were divided into 4 groups of 6 rats each (n = 6); all groups were pretreated orally either 0.9 % Normal Saline (NS) or captopril 20 mg/kg for 7 consecutive days followed by single oral administration of Paracetamol 3000 mg/kg or normal saline. The administration of Paracetamol or normal saline was performed 24 hours after the last administration of captopril. After 48 hours of hepatic injury induction, the animals were then sacrificed and the liver was removed for histopathological studies. Low dose (300 mg/kg) for 10 days and high single dose (3000 mg/kg) of paracetamol produced hepatotoxic effects. While captopril 20 mg/kg showed marked protection against changes induced by low and high dose of paracetamol on the liver

Performance of radial point interpolation method in solving kinematic wave equation for hydrologic modelling

This paper presents the solution of the kinematic wave equation using a meshless radial point interpolation method (RPIM). The partial differential equation is discretized using a Galerkin weighted residual method employing RPIM shape functions. A forward difference scheme is used for temporal discretization, while the direct substitution method is employed to solve the nonlinear system at each time step. The formulation is validated against solutions from conventional numerical techniques and physical observation. In all cases, excellent agreements are achieved and hence the validation of the proposed formulation. Optimum values of the multi-quadrics shape parameters were then determined before the assessment of the performance of the method. Based on the convergence rate, it has been shown that the proposed method performs better than the finite difference method and equivalent to the finite element method. This highlights the potential of RPIM as an alternative method for hydrologic modeling

Enhanced meshfree RPIM with NURBS basis function for analysis of irregular boundary domain

Radial Point Interpolation Method (RPIM) has become a powerful tool to numerical analysis due to its ability to provide a higher-order approximation function with the Kronecker delta property, by which the field nodes can be fitted exactly. However, one of the major drawbacks of RPIM is the inefficiency in handling irregular domain problems. This paper presents an enhanced RPIM formulation that employs Non-Uniform Rational B-Splines (NURBS) basis functions to represent the exact geometry of the boundary domain. The NURBS is a mathematical model which provides an efficient and numerically stable algorithm to exactly represent all conic sections in engineering modelling. Taking advantage of the flexibility and adaptivity of RPIM approximation and the accuracy of geometric representations by NURBS, this new method is able to improve geometry accuracy and flexibility in numerical analysis, thus providing a better and more rational approach to analyze irregular domain problems. Numerical problem of steady heat transfer considering curved beam is presented to verify the validity and accuracy of the developed method. The essential boundary condition can simply be imposed using direct imposition as in Finite Element Method (FEM). The result shows that the RPIM/NURBS achieved the converged solution much faster than conventional RPIM and FEM, with the number of nodes required only less than 200 for an error of less than 0.01%. This shows the potential of the developed method as a powerful numerical technique for future development