A New Approximate Closed-Form Distribution and Performance Analysis of a Composite Weibull/Log-Normal Fading Channel

The presence of both the fading and shadowing effects (also called composite multipath/shadowed fading) is often encountered in a realistic radio propagation scenario, thus, making it necessary to consider the simultaneous effect of fading and shadowing on the received signal. The multipath effect is captured using models such as Rician, Nakagami-m, Weibull distribution and shadowing effect is modeled using Log-normal distribution. In this paper we present the closed-form expression of composite (Weibull/log-normal shadowed) fading using the efficient tool proposed by Holtzman. Using this result, the closed-form expression of combined (time-shared) shadowed/unshadowed fading is presented. The performance measures of fading communication systems such as probability density function of signal to noise ratio, amount of fading, outage probability (P_out) and channel capacity are analyzed and expressed in closed form.     

Optimization and validation of an extraction method for the analysis of polycyclic aromatic hydrocarbons in chocolate candies

Abstract: Chocolate is a key ingredient in many foods such as milk shakes, candies, bars, cookies, and cereals. Chocolate candies are often consumed by mankind of all age groups. The presence of polycyclic aromatic hydrocarbons (PAHs) in chocolate candies may result in health risk to people. A rapid, precise, and economic extraction method was optimized and validated for the simultaneous determination of polycyclic aromatic hydrocarbons in chocolate candy by high‐performance liquid chromatography (HPLC) and gas chromatography‐mass spectrometry (GS‐MS) as a confirmatory technique. The method was optimized by using different solvents for liquid–liquid extraction, varying volume of de‐emulsifying agent, and quantity of silica gel used for purification. The HPLC separation of 16 PAHs was carried out by C‐18 column with mobile phase composed of acetonitrile : water (70 : 30) in isocratic mode with runtime of 20 min. Limit of detection, limit of quantification (LOQ), and correlation coefficients were found in the range of 0.3 to 4ng g^?1, 0.9 to 12ng g^?1, and 0.9109 to 0.9952, respectively. The exploration of 25 local chocolate candy samples for the presence of PAHs showed the mean content of benzo[a]pyrene as 1.62 ng g^?1, which representing the need to evaluate effective measures to prevent more severe PAHs contamination in chocolate candies in future. Practical Application: Chocolate is one of the most favorite food items among people, especially children. Chocolate candies are often consumed by mankind of all age groups. Chocolate candies are often consumed by children in large quantities. The presence PAHs in chocolate candies may result in health risk to people. In the present study, a precise and cost effective rapid method was employed for the determination of PAHs, which can be employed for daily routine analysis of PAHs in chocolate products.     

Thermo-mechanical Deformation in Magneto-micropolar Elastic Medium

The present investigation is concerned with a two-dimensional problem in electromagnetic micropolar elasticity for a half-space whose surface is subjected to distributed (concentrated or continuous) thermo-mechanical sources in the presence of a transverse magnetic field. As an application of the approach, the sources are taken as uniformly or linearly distributed. Laplace and Fourier transform techniques are used to solve the problem. The integral transforms have been inverted by using a numerical technique to obtain the components of normal strain, normal stress, tangential couple stress, and temperature distribution in the physical domain. Magnetic effects on the components of normal strain, normal stress, tangential couple stress, and temperature distribution have been depicted graphically for two different theories of generalized thermoelasticity, Lord and Shulman (L–S) theory and Green and Lindsay (G–L) theory. A particular case of interest is also deduced from the present investigation.     

On Physical Layer Security of Double Shadowed Rician Fading Channels

Wireless Personal Communications - With the proliferation of fifth-generation (5G) mobile communication wireless networks, the investigation into the performance of physical layer secrecy is...