Iranian Journal of Science and Technology, Transactions A: Science最新文献

Zarshouran gold deposit is located 42 km north of Takab in NW Iran recognized as one of the most significant gold deposits in Iran. This ore has the gold grade of 2.4 gr/t which contains sulfide minerals such as pyrite and arsenopyrite. The gold recovery is less than 80% due to the association of gold in sulfide minerals. The aim of this research is to investigate the oxidation of sulfide minerals from the Zarshouran gold mine using the ferric-ionic acid system prior to the cyanidation process. Consequently, an experimental design was employed to investigate and optimize the key parameters affecting the oxidation of resistant ore by ferric ion including ferric ion concentration, pH, pulp solid percentage, temperature, and time. The results indicated that pH, iron sulfate concentration, pulp solid percentage, temperature, and time significantly influence gold recovery, respectively. Following oxidation with ferric ion and the cyanidation process under optimal conditions (iron sulfate concentration of 4 gr/t, temperature of 42 degrees Celsius, time of 6 h, pulp solid percentage of 15%, and pH of 1%), gold recovery improved from 41 to 67.85%.

In this paper, we establish some necessary and sufficient conditions for multiply warped product manifolds admitting a gradient Ricci-Yamabe soliton. For this purpose, the potential function of this soliton and the conditions that must be satisfied for each component of the multiply warped product manifold are investigated. As physical applications, multiply generalized Robertson–Walker spacetimes and generalized Reissner-Nordström spacetimes are discussed and results regarding the existence of gradient Ricci-Yamabe solitons on them are obtained.

Let ({mathfrak {R}}={mathbb {Z}}_{2}+u{mathbb {Z}}_{2}), where (u^2=0), and ({textbf {S}}={mathbb {Z}}_{2}+u{mathbb {Z}}_{2}+v{mathbb {Z}}_{2}+uv{mathbb {Z}}_{2}), where (u^{2}=v^{2}=0), (uv=vu). In this article, we study ({mathfrak {R}} {textbf {S}})-additive cyclic, additive constacyclic, and additive dual codes. We find the structural properties of these codes. The code C is characterized as an ({textbf {S}}[y])-submodules of the ring ({textbf {S}}_{beta _{1},beta _{2}}={{mathfrak {R}}[y]/langle y^{beta _{1}}-1rangle }times {{textbf {S}}[y]/langle y^{beta _{2}}-1rangle }). We define the extended Gray map (Psi _{1}:{mathfrak {R}}^{beta _{1}}times {textbf {S}}^{beta _2}longrightarrow {mathbb {Z}}_{2}^{n}) and use this map to find the binary images with good parameters. We also obtain the minimal generating polynomials and minimal spanning sets of the above-mentioned codes. Further, we provide some examples to support of ({mathfrak {R}} {textbf {S}})-additive cyclic codes. Finally, we present a Table 1 of optimal binary codes.

In this paper, the ultraspherical wavelet operational matrix of derivative method is proposed for the solution of non-linear ordinary differential equation arising in the study of heat transfer through a ternary hybrid nanofluid flow over a moving wet porous fin under the influence of magnetic field with natural convection and radiation. The proposed technique is applied to the test problem having the exact solution and the solution obtained is very close to the exact solution. The considered fin problem is solved using UWOMDM and the result obtained for certain fixed parameters are compared and found to be in good agreement with the result given in the literature. The comparisons validate the UWOMDM. The influence of various physical aspects on thermal distribution and heat transmission rate of the ternary hybrid nanofluid over the straight moving fin is studied. It is inferred that the ternary hybrid nanofluid provides better heat transfer followed by hybrid and mono nanofluids. Ternary hybrid nanofluid with platelet shape allows more heat transfer followed by cylindrical and spherical shapes. Improving Peclet number by 800% increases the fin tip temperature by 2.955%. Hartmann number, convective and radiation parameters help for faster cooling the fin. The heat transmission rate at the fin base escalates for higher Hartmann number, wet porous parameter, convective parameter and radiation parameter and declines for higher Peclet number.

The primary aim of this study is to determine the radii of k-starlikeness, k-uniform convexity, and the radii of starlikeness and convexity related to the exponential function for the Barnes G-Function. The findings presented in this study are novel, and their significance is illustrated by several interesting consequences, examples and graphical representations.

In this article, a spectral function for the singular impulsive dynamic Dirac system is obtained. In terms of this function, the Parseval equality and expansion formula in eigenfunctions is given.

This article presents a three-dimensional discrete-time ecological model to elucidate the intricate dynamics among three distinct species within an ecosystem. This approach extends traditional two-dimensional models, offering a more comprehensive perspective on ecological interactions. We identify all biologically feasible equilibria and perform a local stability analysis for each equilibrium point. Through bifurcation analysis (Neimark-Sacker and period-doubling bifurcations), we successfully demonstrate chaotic attractors via period doubling in the discrete-time model and implement chaos control through numerical simulations. By integrating this mathematical model, we derive ecological insights that contribute to informed conservation and management strategies, promoting sustainable biodiversity preservation.

The thin films of Vanadium Pentoxide nanoparticles (V₂O₅) were deposited on an Aluminium alloy-6061 (Al-6061) substrate by Sol–gel process through a spin coating technique. The film’s phase, purity, crystal nature, surface morphology, and elemental mapping of V₂O₅ thin film on Al-6061 substrate were obtained via X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray analysis. They also examined their anticorrosive properties through the weight loss method, electrochemical measurements such as Potentiodynamic Polarization, and Electrochemical Impedance Spectroscopic studies under various environments by immersing the substrate in acid chloride, acid sulfate, acid nitrate, and neutral chloride medium at room temperature. The obtained results reflect the improvement in the surface property against the corrosion in terms of corrosion resistance of the V₂O₅ thin film-coated Al-6061 substrate compared to that of the bare substrate.

The objective of this paper is to introduce and study a within-host viral infection model via both modes of viral transmission mechanism; virus-to-cell and cell-to-cell. The proposed model incorporates the role of adaptive immunity in limiting viral pathogen spread, including humoral and cellular immune responses. This paper focuses on describing the long memory effect using the Caputo derivative. This study begins with the investigation of the well-posedness of our mathematical model concerning demonstrating the existence, positivity and boundedness of solutions. Then, it moves to introduce all the problem’s steady states, which are determined by specific reproduction numbers. Subsequently, the work proceeds to demonstrate the global stability of the five equilibria points. To evaluate the theoretical findings of global stability, we employ a numerical technique based on the fundamental theorem of fractional calculus, in addition to utilizing a three-step Lagrange polynomial interpolation method. Numerical simulations have shown the effect of drug therapies on the dynamical behavior of the fractional-order system.

We study a two-field model where a quintessence field with an exponential potential (e^{-beta phi /M_P}) is coupled to the Higgs field. It is claimed that this model is consistent with the proposed Swampland conjecture. We check this claim by calculating its inflationary observables. Although, these observables are in good agreement with the latest CMB data, but we find an upper bound (beta, lesssim, 8times 10^{-3}) that strongly disfavors the Swampland conjecture.