Search Results (18)

Zinc (Zn) fertilization is widely used in maize (Zea mays L.) production to alleviate Zn deficiency and improve biomass and grain yield. However, limited research exists on Zn management in maize cultivated in high-pH paddy soils following rice-based systems, where altered soil chemistry may affect Zn availability and plant uptake. This study aimed to evaluate the effects of Zn application rates on growth, yield, and Zn uptake in two hybrid maize varieties under such conditions. Field experiments were conducted during the 2019 and 2020 dry seasons in Phetchabun Province, Thailand, using a randomized complete block design with a 4 × 2 factorial arrangement and four replications. Treatments included four Zn rates (0, 5, 10, and 20.6 kg of Zn/ha), applied as Zn sulfate monohydrate (ZnSO₄·H₂O, 36% Zn) by soil banding at the V6 stage, and two hybrid varieties, Suwan 5731 (SW5731) and Suwan 5819 (SW5819). In 2019, significant Zn × variety interactions were observed for biomass, crop growth rate (CGR), and grain yield. SW5819 at 10 kg of Zn/ha produced the highest biomass (31.6 t/ha) and CGR (25.6 g/m²/day), increasing by 15.3% and 39.1%, respectively, compared to its own no Zn treatment. In contrast, 20.6 kg of Zn/ha reduced SW5819 biomass by 6.6% and 13.1% relative to SW5731 and its own no-Zn treatment, respectively. Grain yield in SW5819 peaked at 14.7 t/ha under 5 and 10 kg of Zn/ha, significantly higher than SW5731 under 0 and 5 kg of Zn/ha by 16.7%, while SW5731 showed no significant response. In SW5819, shoot and grain Zn uptake significantly increased under 5 and 10 kg of Zn/ha by up to 36.8% and 33.3%, respectively, compared to no Zn treatment. The lowest shoot Zn uptake was found in SW5819 under 20.6 kg of Zn/ha (264.1 ± 43.9 g/ha), which was lower than all its Zn treatments and all SW5731 treatments, showing a reduction of 19.4–43.6%. Zn application improved soil Zn availability, and Zn partitioning among plant organs varied with Zn rate and season. A moderate Zn rate (10 kg of Zn/ha) optimized maize performance under high-pH, rice-based conditions, emphasizing the need for variety-specific Zn management. Full article

Hepatitis C virus (HCV) remains a global health challenge, contributing to chronic liver disease and hepatocellular carcinoma. In Thailand, HCV prevalence has declined from ~2% in the 1990s due to universal blood screening, harm reduction, and expanded treatment. This narrative review draws on diverse sources—including PubMed and Scopus databases, international and national health websites, government reports, and local communications—to compile epidemiological data, genotype distribution, and elimination strategies, with a focus on Phetchabun province, Thailand, as a model for achieving the World Health Organization’s (WHO) hepatitis C elimination targets. National surveys in 2004, 2014, and 2024 show a prevalence drop from 2.15% to 0.56%. However, HCV persists among high-risk groups, including people who inject drugs, people living with HIV, patients undergoing maintenance hemodialysis, and prisoners. Thailand’s National Health Security Office has expanded treatment access, including universal screening for those born before 1992. The Phetchabun Model, launched in 2017, employs a decentralized test-to-treat strategy. By April 2024, 88.64% (288,203/324,916) of the target population was screened, and 4.88% were anti-HCV positive. Among those tested, 72.61% were HCV-RNA positive, and 88.17% received direct-acting antivirals (i.e., SOF/VEL), achieving >96% sustained virological response. The Phetchabun Model demonstrates a scalable approach for HCV elimination. Addressing testing costs, improving access, and integrating microelimination strategies into national policy are essential to achieving the WHO’s 2030 goals. Full article

In this paper, we introduce a new type of contraction, an M-auxiliary contraction, by modifying existing concepts involving auxiliary functions. We establish existence and uniqueness results for common fixed points of the proposed contraction mapping under suitable conditions. Applications to fractional differential equations and ordinary differential equations are provided to demonstrate the effectiveness of the main theorem. Full article

This study investigates the mechanisms driving current generation, power output, and charge storage in carbon nanotube springs under mechanical strain, addressing the gap between experimental observations and theoretical modeling, particularly in asymmetric electrical responses. Leveraging the Dirac equation in curved spacetime, we analyze how curvature-induced scalar and pseudo-gauge potentials shape two-dimensional electron gases confined to carbon nanotube springs. We incorporate applied mechanical strain by introducing time-dependent variations in the Lamé coefficient and curvature parameters, enabling the analysis of mechanical deformation’s influence on electrical properties. Our model clarifies asymmetric electrical responses during stretching and compression cycles and explains how strain-dependent power outputs arise from the interplay between mechanical deformation and curvature effects. Additionally, we demonstrate mechanisms by which strain influences charge redistribution within the helically coiled structure. We develop a new equivalent circuit model linking mechanical deformation directly to electronic behavior, bridging theoretical physics with practical electromechanical applications. The analysis reveals asymmetric time-dependent currents, enhanced power output during stretching, and strain-dependent charge redistribution. Fourier analysis uncovers dominant frequency components (primary at $\Omega$, harmonic at $2\Omega$) explaining these asymmetries. Theoretical investigations explain the mechanisms behind the curvature-driven time-dependent current source, the frequency-dependent peak power, the characteristics of open-circuit voltage with strain, and the asymmetric electrical property response under applied strain as the generated current and the charge distribution within the carbon nanotube springs. These findings highlight carbon nanotube springs applied to energy harvesting, wearable electronics, and sensing technologies. Full article

Toxic gases emitted by industries and vehicles cause environmental pollution and pose significant health risks which are becoming increasingly dangerous. Therefore, the detection of the toxic gases is crucial. The development of gas sensors with high sensitivity and fast response based on nanomaterials has garnered significant interest. In this work, we studied the adsorption behavior of ${{\mathrm{B}}_9}^{-}$ wheel structures of pristine and nitrogen functionalized borophene quantum dots for major hazardous environmental gases, such as NO₂, CO₂, CO, and NH₃. The self-consistent-charge density-functional tight-binding method (SCC-DFTB) method was performed to investigate structural geometries, the most favorable adsorption sites, charge transfer, total densities of states, and electronic properties of the structures before and after adsorption of the gas molecules. Based on calculated results, it was found that the interaction between the borophene quantum dots and the gas molecules was chemisorption. The functionalized nitrogen atom contributed to impurity states, leading to higher adsorption energies of the functionalized borophene quantum dots compared to the pristine ones. Total densities of states revealed insights into electronic properties of gas molecules adsorbed on borophene quantum dots. The nitrogen-doped borophene quantum dots demonstrated excellent performance as a sensing material for hazardous environmental gases, especially CO₂. Full article

Unconstrained optimization problems have a long history in computational mathematics and have been identified as being among the crucial problems in the fields of applied sciences, engineering, and management sciences. In this paper, a new variant of the conjugate descent method for solving unconstrained optimization problems is introduced. The proposed algorithm can be seen as a modification of the popular conjugate descent (CD) algorithm of Fletcher. The algorithm of the proposed method is well-defined, and the sequence of the directions of search is shown to be sufficiently descending. The convergence result of the proposed method is discussed under the common standard conditions. The proposed algorithm together with some existing ones in the literature is implemented to solve a collection of benchmark test problems. Numerical experiments conducted show the performance of the proposed method is very encouraging. Furthermore, an additional efficiency evaluation is carried out on problems arising from signal processing and it works well. Full article

This study investigates the extension of the c-chart control chart to Bayesian methodology, utilizing the gamma distribution to establish control limits. By comparing the performance of the Bayesian approach with that of two existing methods (the traditional frequentist method and the Bayesian with Jeffreys method), we assess its effectiveness in terms of the average run lengths (ARLs) and false alarm rates (FARs). Simulation results indicate that the proposed Bayesian method consistently outperforms the existing techniques, offering larger ARLs and smaller FARs that closely approximate the expected nominal values. While the Bayesian approach excels in most scenarios, challenges may arise with large values of the λ parameter, necessitating adjustments to the hyperparameters of the gamma prior. Specifically, smaller values of the rate parameter are recommended for optimal performance. Overall, our findings suggest that the Bayesian extension of the c-chart provides a promising alternative for enhanced process monitoring and control. Full article

The Doi Chiang Dao massif, which became a UNESCO Biosphere Reserve in 2021, is the highest karst mountain in Thailand. Tham Chiang Dao cave is located at the foot of this massif and is among the best-known caves in Thailand, having been visited since prehistoric times, and being a sacred place for the local Shan and Thai people. The cave consists of five main interconnected passages with a total length of 5342 m which ranks it as the 11th longest cave in Thailand. Tham Chiang Dao is the best studied cave in Thailand with a long series of explorations, investigations and zoological collecting. Here, we summarize the 110 years of biological exploration and investigation devoted to this cave. A total of 149 taxa have been recognized in Tham Chiang Dao, of which 61 have been identified to species level. The cave is the type locality for 14 species. The obligate subterranean fauna includes 37 species, of which 33 are troglobionts and 4 are stygobionts. Conservation issues are addressed in the discussion. This work is intended to provide a reference for the knowledge of cave fauna of the Chiang Dao Wildlife Sanctuary and a tool for its management by the local cave management committee, the National Cave Management Policy Committee, and the Department of Mineral Resources. It also documents the biological importance of Tham Chiang Dao in the Doi Chiang Dao UNESCO Biosphere Reserve. Full article

In matrix analysis, the scaling technique reduces the chances of an ill-conditioning of the matrix. This article proposes a one-parameter scaling memoryless Davidon–Fletcher–Powell (DFP) algorithm for solving a system of monotone nonlinear equations with convex constraints. The measure function that involves all the eigenvalues of the memoryless DFP matrix is minimized to obtain the scaling parameter’s optimal value. The resulting algorithm is matrix and derivative-free with low memory requirements and is globally convergent under some mild conditions. A numerical comparison showed that the algorithm is efficient in terms of the number of iterations, function evaluations, and CPU time. The performance of the algorithm is further illustrated by solving problems arising from image restoration. Full article

Many practical applications in applied sciences such as imaging, signal processing, and motion control can be reformulated into a system of nonlinear equations with or without constraints. In this paper, a new descent projection iterative algorithm for solving a nonlinear system of equations with convex constraints is proposed. The new approach is based on a modified symmetric rank-one updating formula. The search direction of the proposed algorithm mimics the behavior of a spectral conjugate gradient algorithm where the spectral parameter is determined so that the direction is sufficiently descent. Based on the assumption that the underlying function satisfies monotonicity and Lipschitz continuity, the convergence result of the proposed algorithm is discussed. Subsequently, the efficiency of the new method is revealed. As an application, the proposed algorithm is successfully implemented on image deblurring problem. Full article

The current paper intends to report the existence and uniqueness of positive solutions for nonlinear pantograph Caputo–Hadamard fractional differential equations. As part of a procedure, we transform the specified pantograph fractional differential equation into an equivalent integral equation. We show that this equation has a positive solution by utilising the Schauder fixed point theorem (SFPT) and the upper and lower solutions method. Another method for proving the existence of a singular positive solution is the Banach fixed point theorem (BFPT). Finally, we provide an example that illustrates and explains our conclusions. Full article

This paper presents the high-output-impedance current-mode multiphase sinusoidal oscillators (MSO) using voltage differencing current conveyor (VDCC)-based lossy integrators, which consist of one VDCC, one grounded capacitor, and two grounded resistors. The proposed oscillator can provide an odd-phase and even-phase system without the use of an additional amplifier. The frequency of oscillation (FO) is electronically tuned via the bias current without affecting the condition of oscillation (CO). The proposed oscillator is designed to obtain three-phase sinusoidal waveforms (n = 3). The effect of non-idealities of VDCC on the lossy integrator section is also investigated. The validity of the proposed circuit is demonstrated by PSPICE simulation using 0.18 µm TSMC CMOS process parameters with ±0.9V power supply. The frequency of oscillation obtained from the simulation is 1.43 MHz. The total harmonic distortions of the sinusoidal output currents I_O1, I_O2, and I_O2 are 1.22%, 1.18%, and 0.57%. The I_O1–I_O2 and I_O2–I_O3 phase differences are approximately 121 and 119 degrees, respectively. The feasibility of the proposed MSO is also verified with experimental results using the VDCC constructed from the commercially available ICs (LT1288 and AD844) with ±5 V power supply. The results of PSPICE simulations and experiments are closely consistent with the theoretical expectation. Full article

Nonlinear systems of equations are widely used in science and engineering and, therefore, exploring efficient ways to solve them is paramount. In this paper, a new derivative-free approach for solving a nonlinear system of equations with convex constraints is proposed. The search direction of the proposed method is derived based on a modified conjugate gradient method, in such a way that it is sufficiently descent. It is worth noting that, unlike many existing methods that require a monotonicity assumption to prove the convergence result, our new method needs the underlying function to be pseudomonotone, which is a weaker assumption. The performance of the proposed algorithm is demonstrated on a set of some test problems and applications arising from compressive sensing. The obtained results confirm that the proposed method is effective compared to some existing algorithms in the literature. Full article

Two new inertial-type extragradient methods are proposed to find a numerical common solution to the variational inequality problem involving a pseudomonotone and Lipschitz continuous operator, as well as the fixed point problem in real Hilbert spaces with a $\rho$-demicontractive mapping. These inertial-type iterative methods use self-adaptive step size rules that do not require previous knowledge of the Lipschitz constant. We also show that the proposed methods strongly converge to a solution of the variational inequality and fixed point problems under appropriate standard test conditions. Finally, we present several numerical examples to show the effectiveness and validation of the proposed methods. Full article

The objective of this paper is to introduce an iterative method with the addition of an inertial term to solve equilibrium problems in a real Hilbert space. The proposed iterative scheme is based on the Mann-type iterative scheme and the extragradient method. By imposing certain mild conditions on a bifunction, the corresponding theorem of strong convergence in real Hilbert space is well-established. The proposed method has the advantage of requiring no knowledge of Lipschitz-type constants. The applications of our results to solve particular classes of equilibrium problems is presented. Numerical results are established to validate the proposed method’s efficiency and to compare it to other methods in the literature. Full article