Production of Urea/Acetylated-ligninsulfonate Matrix as SRFs and Investigation the Effect of Hydrodynamic Conditions on the Release Rate Using Biot Number

Background: This study aimed to investigate the effect of the hydrodynamic condition on the release rate of urea/acetylated lignin sulfonate (Ac-LS) matrix as slow-release fertilizers (SRFs). Therefore, two models were developed using the mass transfer balance for the finite/infinite volume of fluids, solving finite integral transform/separation of a variable. In these models, the Biot number that verified the hydrodynamic condition appeared. Methods: In the experimental section, the urea/Ac-LS matrix fertilizer was produced. The morphological, thermal, chemical, and mechanical properties of the LS, Ac-LS, urea, and urea/Ac-LS matrix were analyzed using Fe-SEM, TGA, XRD, and SANTAM. Finally, the nitrogen release of the matrix fertilizer was investigated at 25°C for different impeller speeds. Results: The results showed that the thermal and mechanical resistance of urea/Ac-LS, with strong interaction, increased rather than pure urea or Ac-LS. The models were also validated using experimental data. The results further showed that in both states, the external resistance of the mass transfer decreased with increasing impeller speed, and the nitrogen release rate increased with increasing Biot number. Conclusion: It was also observed that, in a given hydrodynamic condition, initially, the release rate in the finite environment was less than the infinite; however, after a while, the type of environment did not affect the release rate

New Straightforward Benchmark Solutions for Bending and Free Vibration of Clamped Anisotropic Rectangular Thin Plates

This study presents new straightforward benchmark solutions for bending and free vibration of clamped anisotropic rectangular thin plates by a double finite integral transform method. Being different from the previous studies that took pure trigonometric functions as the integral kernels, the exponential functions are adopted, and the unknowns to be determined are constituted after the integral transform, which overcomes the difficulty in solving the governing higher-order partial differential equations with odd derivatives with respect to both the in-plane coordinate variables, thus goes beyond the limit of conventional finite integral transforms that are only applicable to isotropic or orthotropic plates. The present study provides an easy-to-implement approach for similar complex problems, extending the scope of finite integral transforms with applications to plate problems. The validity of the method and accuracy of the new solutions that can serve as benchmarks are well confirmed by satisfactory comparison with the numerical solutions.

Finite Integral Involving the Modified Generalized Aleph-Function of Two Variables Extension and Generalized Extented Hurwitz’s Zeta Function

In the present paper, we evaluate the general finite integral invoving the generalized Zeta function and the modified of generalized Aleph-function of two variables.

Optimized Planar Microwave Antenna for Nitrogen Vacancy Center Based Sensing Applications

Individual nitrogen vacancy (NV) color centers in diamond are versatile, spin-based quantum sensors. Coherently controlling the spin of NV centers using microwaves in a typical frequency range between 2.5 and 3.5 GHz is necessary for sensing applications. In this work, we present a stripline-based, planar, Ω-shaped microwave antenna that enables one to reliably manipulate NV spins. We found an optimal antenna design using finite integral simulations. We fabricated our antennas on low-cost, transparent glass substrate. We created highly uniform microwave fields in areas of roughly 400 × 400 μm2 while realizing high Rabi frequencies of up to 10 MHz in an ensemble of NV centers.

Analytical Investigation of Non-Fourier Bio-Heat Transfer in the Axisymmetric Living Tissue Exposed to Pulsed Laser Heating Using Finite Integral Transform Technique

The present article proposed the closed-form solution of the generalized non-Fourier model-based bio-heat transfer equation (BHTE) in Cylindrical coordinates to understand the thermal behavior of living tissue heated by a pulsed laser. The axisymmetric living tissue exposed to the non-Gaussian temporal profile of laser heating has been considered to investigate the non-Fourier bio-heat transfer phenomena. The closed-form solution of the generalized non-Fourier model-based BHTE with time-dependent thermal energy generation has been obtained through the finite integral transform technique. The analytical solution was juxtaposed to the corresponding numerical solution in order to determine its reliability. The numerical solution of the aforementioned governing equation has been obtained by the finite volume method. The results of both analytical and numerical solutions have been verified using results given in published literature. Subsequently, the dual-phase-lag model's findings were juxtaposed to those obtained using the hyperbolic and traditional Fourier models. The effect of different parameters like relaxation times corresponding to the temperature gradient and heat flux, metabolic energy generation, and blood perfusion on the resultant temperature distribution inside the axisymmetric living tissue exposed to pulsed laser heating has been discussed. The importance of the present study might be found in various applications such as laser-based-photo-thermal therapy, melting of the surface of metal and alloys by laser heating, etc.

Finite Integral Involving the Generalized Modified I-Function of Two Variables

In the present paper, we evaluate the general finite integral involving the generalized modified I-functions of two variables. At the end, we shall see several corollaries and remarks.

A novel methodology for time-domain characterization of a full anechoic chamber for antennas measurements and exposure evaluation

<p>In this paper we present a novel methodology for time-domain characterization of a full anechoic chamber using the finite integral method. This approach is considered fast, accurate and not intensive for computer resources. The validation of this approach is carried out on CST-microwave studio for a full anechoic chamber intended for antennas measurement applications and electromagnetic exposure evaluation for cellular network. Low, medium and high gain sources are used in this study. The simulations are realized on a personal computer of medium performances (i7 CPU and 16 GB of RAM). The stability and the convergence of our approach are obtained thanks to local mesh and auto-regressive linear filtering techniques. The minimization of the simulation time is based on use of the Huygens sources in the place of the antennas. The maximum error of the chamber as well as the wave depolarization into the chamber are at one with the previous work and the catalogs of the principles chambers manufacturers for the proposed tests in this paper. The Full simulations time is about 15 hours in average.</p>

Finite Integral Involving the Modified Generalized Aleph-Function of Two Variables and Elliptic Integral of First Species I

In the present paper, we evaluate the general finite integral involving the elliptic integrals of first species and the generalized modified Aleph- function of two variables. At the end, we shall see several corollaries and remarks.