This study focuses on the synthesis and characterization of zinc (Zn)-doped cuprous oxide nanoparticles, denoted as ZnxCu2O, prepared by a room-temperature co-precipitation method. The Zn doping content was varied from 0 to 30%. X-ray diffraction (XRD) confirmed that the nanoparticles predominantly exhibit the cubic Cu2O phase. With increasing Zn content, the crystallite size gradually decreased, consistent with changes in lattice parameters and microstrain. Raman and FTIR analyses verified successful Zn incorporation, revealing modifications in Cu-O vibrational modes and the emergence of Zn-O bonding features. FE-SEM observations showed reduced particle size and increased agglomeration at higher Zn doping levels, in agreement with XRD results. Optically, the band gap energy (Eg) increased at low Zn doping due to the Burstein–Moss effect, then decreased at higher doping levels because of secondary ZnO phase formation. Photocatalytic experiments demonstrated that the sample with an optimal Zn content of 10% (x = 0.1) exhibited superior degradation performance toward common organic pollutants, including Rhodamine B, ciprofloxacin, and sulfamethoxazole. These results highlight the strong potential of ZnxCu2O nanomaterials for wastewater treatment and environmental remediation.
G6PD deficiency, an enzymopathy associated with glucose-6-phosphate dehydrogenase (G6PD), is caused by genetic mutations that reduce the enzyme activity, resulting in hemolytic anemia. Biochemical studies have shown that G6PD deficiency in various variants is associated with reduced thermal stability, reduced catalytic activity, or both. In this study, we investigate the structural stability of the wild-type G6PD monomer at a physiological temperature using molecular dynamics simulations, in the absence and in the presence of its G6P and NADP+ ligands. We find that the G6P ligand has a low affinity for the G6PD monomer, which may result from fluctuations in the size of its binding pocket. This finding is consistent with and helps explain the catalytic inactivity of monomeric G6PD. Our analysis also shows that, with a statistically significant confidence, class I mutations occur preferentially at residues that are more flexible than randomly selected residues, whereas class II mutations tend to occur at residues that are less flexible than randomly selected ones. This result reflects the distinct structural roles of the G6PD mutation sites and further supports the relationship between enzyme activity and thermal stability.
The development of a regularized perturbation theory method for solving the Schrödinger equation of an exciton in a black phosphorus monolayer—a two-dimensional anisotropic material—yields a novel form of double integrals that is substantially more complex than that in previous studies on isotropic excitons. Direct computation of these integrals requires a significant amount of computational time and resources. In this study, we propose an analytical calculation scheme for these integrals based on the Newton binomial theorem, combined with Taylor expansion and a regularization method that utilizes a free parameter. This approach expresses the integrals as linear combinations of simpler single integrals, which can be evaluated through recurrence relations, making them suitable for numerical implementation. Moreover, a free parameter is introduced and optimized to enhance calculation speed. With this scheme, the evaluation speed of the integrals is improved dramatically—by several orders of magnitude—resulting in exciton energy-level calculations that are accelerated by up to five orders of magnitude. These findings present a new approach for the numerical treatment of complicated integrals, thereby enhancing computational efficiency in similar problems.
This study investigates defect states in p-silicon wafer using Deep Level Transient Spectroscopy method. Two-hole traps with activation energy of 0.32 and 0.58 eV were observed at temperatures of 212 and 252 K, respectively. These hole traps could be boron-related defects introduced during doping process. By using capacitance-voltage measurement, the doping concentration was estimated to be approximately 7$\times$10\textsuperscript{15} cm\textsuperscript{-3}, and the maximum defect density of about 4$\times$10\textsuperscript{14} cm\textsuperscript{-3}. The obtained results showed that the high defect states could be formed naturally during deposition progress. Understanding how defects interact within p-Si is essential for defect engineering in the future.
The interplay between carbohydrates and water molecules is fundamental to understanding the intricate metabolic processes in biological systems. This study examines the structural and electronic properties of hydrated $\beta$-glucose, $G(H_{2}O)_{n}$, where $0 \leq n \leq 15$, using the explicit and implicit solvent models. Explicit (implicit) model reveals that the average length of the H-bond reaches a minimum of 1.76 (1.79) {\AA} when the hydration shell is filled with nine water molecules. Stepwise hydration energies remain negative for all of $n$, indicating a thermodynamically favorable hydration process. However, the inconsistency between the two models when $n$ is either small ($n \leq 3$) or large ($n \geq 13$) emphasizes the need for careful selection of the solvent model. For the two models, the trend in HOMO energies is an increase up to $n=10$ and then a decrease. The energy gap between the highest occupied and lowest unoccupied molecular orbitals is highly sensitive to $n$ for the explicit model. In contrast, it is less sensitive in the implicit model for $n \geq 6$. These findings highlight the explicit inclusion of water molecules even when an implicit model is utilized.
This study quantitatively investigates the physicochemical evolution of protective layers on ZnAl alloy coated carbon steel, focusing on the inhibitory performance of cerium-based compounds Ce(NO3)3 in a chloride medium. A combination of electrochemical techniques, Open Circuit Potential monitoring, Potentiodynamic Polarization and Electrochemical Impedance Spectroscopy, was employed to demonstrate the addition of Ce3+ ions significantly enhances corrosion resistance. For the uninhibited solution, EIS modeling consistently revealed a continuous increase in capacitive elements and a drastic decline in resistive elements. signifying physical barrier breakdown. The optimal concentration, 10-4 M, fostered the growth of a stable, progressively densifying Ce-enriched layer. This layer maintained high Rct (up to 8553 Ω.cm2), confirming its superior physical barrier integrity. Surface morphology analysis using Scanning Electron Microscopy corroborated this finding, revealing the formation of a homogeneous, crack-free cerium containing film structure at this optimal concentration. Conversely, the 5×10-4 M concentration led to long-term failure, attributed to the formation of a mechanically weak, heterogeneous outer deposit prone to cracking. These findings quantitatively establish the relationship between cerium concentration, the resulting film's physical structure, and its long-term anti-corrosion durability.
This study investigates the generation and power amplification of an ultrabroadband modeless Ce:LiCAF ultraviolet (UV) laser using combined numerical and experimental approaches. Pumped at 266 nm, the Ce:LiCAF source produces a modeless UV spectrum from 275 to 330 nm with a dominant peak at ≈288.5 nm (FWHM ≈16 nm) and a weaker band near 310 nm. We develop a multiwavelength propagation model in which the spectrum is represented by discrete wavelength channels with wavelength-dependent emission, absorption, and excited-state absorption cross-sections, and we include pump absorption, gain saturation, and amplified spontaneous emission (ASE). Experimentally, a four-pass Ce:LiCAF amplifier is implemented, and spectra and pulse energies are measured after the oscillator and after each pass at a fixed 266 nm pump energy. The amplified source delivers up to 1 mJ per pulse, with the FWHM of the 288.5 nm peak reduced from 16 nm to 7 nm, indicating moderate gain narrowing while preserving the two-band spectrum. Numerical predictions agree with the measurements (deviations <10 % in output energy and <1 nm in peak wavelength), showing that this modeless Ce:LiCAF system is a promising source for broadband UV absorption spectroscopy and trace-gas detection.
The Hall effect in infinite Semi-parabolic Plus Semi-inverse Squared Quantum wells (ISPPSISQW) in the presence of a strong Electromagnetic Wave(EMW) is theoretically investigated by using the Quantum Kinetic Equation. The system is subjected to a strong EMW \(\vec{E}(t)=\left(E_0 \sin \Omega t\right) \vec{e}_y\), a magnetic field \(\vec{B}=B \vec{e}_z\), and a cross DC electric field \(\vec{E}=E \vec{e}_x\). The electron-optical phonon scattering is considered. The general expression of the Hall coefficient is presented as a function of the temperature, the external magnetic field, the photon energy, and the intensity of the strong EMW as well as characteristic parameters of ISPPSISQW. The theoretical result for a specific GaAs/GaAsAl ISPPSISQW is obtained by using a numerical method. The computational result demonstrates that the maximum peaks appear satisfying the magneto-phonon-photon resonance condition. For the dependence of Hall coefficient on the magnetic field B : when temperature changes, the resonance peak's position is unaffected by temperature variations; and when confinement frequency increases, the Hall coefficient peak increases in magnitude and the position of the peak shifts towards the smaller magnetic field B. For dependence of Hall Coefficient on the electromagnetic wave frequency: when temperature changes, the peak decreases but the position of the peak does not change; and when increasing confinement frequency, the magnitude of the peak increases and the peak is blue-shifted; and when the external magnetic field \(B\) is increased, the magnitude of the Hall coefficient increases, and the peak position is blue-shifted (i.e. shifted towards higher frequencies).
The development of highly sensitive and selective gas sensors is essential for detecting toxic gases such as NO$_2$ at trace levels. In this study, MoSe$_2$ nanostructures with tunable morphologies were synthesized via a hydrothermal method by adjusting the reaction time. Structural analysis using XRD, Raman spectroscopy, and TEM confirmed the formation of hexagonal-phase MoSe$_2$ with a hierarchical flower-like morphology composed of ultrathin nanosheets. The optimized sample, obtained at 36 hours of hydrothermal growth, exhibited the smallest crystallite size (4.74 nm), the largest specific surface area, and the lowest activation energy (0.23 eV). These features collectively contributed to its superior NO$_2$ sensing performance. Gas-sensing measurements revealed a rapid and reversible response to NO$_2$ at room temperature. These findings highlight the great potential of MoSe$_2$ nanostructures as efficient, low-power gas sensing materials and provide valuable insights into morphology-controlled synthesis for optimizing two-dimensional materials in environmental monitoring applications.
This study determines the Hamaker constant for van der Waals interactions between metallic nanoparticles in water, incorporating realistic size-dependent dielectric properties. Using Lifshitz theory, the Hamaker constant is evaluated through Matsubara summation and an integral formulation based on the dielectric function at imaginary frequencies. To obtain ε(iξ), we combine experimental optical data with a modified Drude model whose damping rate varies with nanoparticle radius, ensuring accurate low- and high-frequency behavior. From experimental refractive-index data, plasma frequencies and damping constants for gold, silver, and copper are extracted in the low-energy range. The resulting Hamaker constants without size effects are 220.0 zJ (Au–water–Au), 215.4 zJ (Ag–water–Ag), and 207.2 zJ (Cu–water–Cu). Including size corrections reduces the Hamaker constant for smaller particles due to enhanced electron surface scattering. These results are applied to compute van der Waals energies between spherical nanoparticles, showing strong dependence on particle size and separation distance.
In this study, porous calcium silicate (CaSiO3) materials were synthesized via a sol-gel method using different concentrations of the nonionic surfactant P123 (10 wt.%, 20 wt.%, and 30 wt.%) as structure-directing agents. The effect of P123 content on the textural properties of the resulting materials was systematically investigated. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and nitrogen adsorption-desorption analysis (BET/BJH) were employed to characterize their structural and morphological features. The results indicate that the sample synthesized with 10 wt.%) P123 (Ca10) exhibited the highest surface area (117.3 m2/g) and well-developed mesoporous structure. Increasing P123 content to 20 wt.%) (Ca20) enhanced pore connectivity and cumulative pore volume, while excessive surfactant (30 wt.%), Ca30) led to structural collapse, resulting in decreased surface area and reduced mesoporosity. These findings highlight the importance of controlling the surfactant content to optimize the porosity of calcium silicate for potential applications in drug delivery, adsorption, and catalysis.
The Berry-curvature signatures and topological transitions of excitonic condensates (ECs) in a two-dimensional electron-hole system including intraband Rashba spin-orbit coupling under an external magnetic field is investigated. Within an unrestricted Hartree-Fock approach, we self-consistently determine spin-resolved EC order parameters. The Berry curvature and Chern number are then evaluated by using the Fukui-Hatsugai-Suzuki method. At a weak field, the Berry curvature is antisymmetric guaranteeing a vanishing total Berry flux over the Brillouin zone and system settles in trivially topological state. Increasing the external magnetic field breaks timereversal symmetry that produces asymmetric curvature and quantizes the Chern number \(C = 2\), identifying a topological spin-up triplet EC phase. Once the field is sufficiently strong, opposite Chern numbers from the occupied bands cancel each other, restoring a trivial topological state. Our results reveal a magnetic-field driven route to stabilize topological spin-up triplet EC state in two-dimensional materials with strong Rashba spin-orbit coupling.
CdTe tetrapod nanocrystals (NCs) were synthesized using a colloidal hot-injection method, and their structural, vibrational, and optical properties were systematically investigated. X-ray diffraction and transmission electron microscopy analyses confirmed the formation of tetrapod-shaped NCs with a zinc-blende (ZB) crystal structure. Raman scattering measurements revealed clear phonon features associated with longitudinal optical and surface optical modes, indicating the presence of phonon confinement effects in the NCs. Optical absorption and photoluminescence spectra exhibited two distinct features attributed to excitonic transitions in the tetrapod core and arms. Temperature-dependent photoluminescence measurements demonstrated significant variations in emission energy, intensity, and linewidth with increasing temperature, which are mainly governed by band-gap shrinkage and exciton--phonon interactions. The experimental results were analyzed using well-established theoretical models, providing insight into the thermal stability and carrier recombination processes in CdTe tetrapod NCs. These findings contribute to a better understanding of the optical behavior of branched semiconductor nanostructures and their potential applications in optoelectronic devices.
Bismuth sodium titanate (BNT) is a crucial lead-free multiferroic material whose functional properties are highly sensitive to surface structure and native defects. This study employs first-principles calculations based on Density Functional Theory (DFT) to systematically investigate the structural, electronic, and optical properties of the BNT(110) surface containing complex antisite defects. We first confirm that the pristine BNT(110) surface undergoes significant atomic relaxation and polarization changes compared to the bulk. Subsequent introduction of antisite defects dramatically modifies the local lattice parameters, leading to significant strain and altered coordination polyhedral. As the results, the antisite defects introduce localized deep-level states within the band gap, resulting in a substantial reduction of the band gap energy. Analysis of the projected density of states (PDOS) reveals that these states are predominantly derived from hybridized Ti-3d and O-2p orbitals from atoms adjacent to the defect site. Furthermore, the calculated optical absorption spectra indicate a strong sub-gap absorption in the visible region due to the defect-induced states, suggesting potential for enhanced light absorption. This study provides critical insights into the intrinsic effects of complex antisite defects on the functional surfaces of BNT, which is essential for optimizing defect engineering strategies in BNT-based electronic and photocatalytic devices.
This study investigates how the structural parameters of suspended-core photonic crystal fibers (SC-PCFs) influence their effective refractive index (neff), focusing on designs based on arsenic sulfide (As₂S₃) with carbon disulfide (CS₂)-filled air holes. As₂S₃ provides a high nonlinear refractive index and wide infrared transparency, while CS₂ infiltration enables enhanced optical control due to its high refractive index. Using Lumerical Mode Solutions, numerical simulations were conducted for TE₀₀ and TE₁₀₀ modes across the wavelength range from 2 to 5 μm, with structure ratios (w/ ) varying from 0.35 to 0.85. Results show that neff increases with slot width and reaches 2.2251 at 2150 nm for CS₂-filled designs. Compared to air-filled fibers, CS₂ infiltration improves refractive index control and optical confinement. These results provides quantitative design guidance for optimizing modal confinement and birefringence in SC-PCFs targeting nonlinear and polarization-sensitive applications in the mid-infrared regime.
We revisit the dark matter phenomenology of a flavor-dependent U(1)X gauge extension of the Standard Model, where anomaly cancellation predicts the existence of exactly three fermion generations and requires the presence of three right-handed neutrinos. In Ref. [1], a strong hierarchy between the vacuum expectation values of two singlet scalars, Λ2 >> Λ1, renders all Z2-odd scalar states heavy, resulting in a two-component dark matter scenario composed exclusively of fermions. In the present work, we relax this simplifying assumption and consider a more general mass spectrum. In particular, scalar mixing can naturally lead to a situation in which the lightest Z2-odd particle is a scalar rather than a fermion. As a consequence, the model admits a qualitatively new realization of two-component dark matter consisting of one fermionic and one scalar component, in addition to the purely fermionic scenario studied previously. We perform a dedicated phenomenological analysis of these two-component dark matter realizations, focusing on the coupled thermal freeze-out dynamics and the resulting relic abundance. Constraints from the observed relic density and current direct-detection limits are taken into account, and viable regions of parameter space are identified.
Linear attenuation coefficients of Al and Pb for the 662 keV gamma rays have been carried out at the Training Center of Dalat Nuclear Research Institute using the Cs-137 source and the handheld equipment TCS-172 gamma scintillation survey meter. The gamma-ray beam emitted from the Cs-137 source was collimated with a narrow beam geometry. The results of our investigation were compared and found to be in good agreement with previously published data.
In this study, Dy³⁺-doped ZnS nanocrystals (NCs) with concentrations varying from 0.5-3% were successfully synthesized by the wet chemical method in a pure Ar atmosphere. XRD and EDX results showed that the material crystallized in a stable cubic phase, with nanometer size, and determined the presence of elements in the sample. FTIR spectra recorded characteristic vibrational bands of Zn–S bonds and surface organic functional groups, confirming the formation of ZnS host and a stable organic coating surrounding the nanoparticles. UV-Vis absorption spectra confirmed the distinct quantum confinement effect compared to bulk ZnS. Photoluminescence (PL) spectra of the sample showed characteristic emission lines of Dy³⁺, in which the gold peak at ~580 nm was dominant. The CIE color coordinate and correlated color temperature (CCT) analysis results showed the ability to tune the color from cool blue light of pure ZnS to warm white light when doped with Dy³⁺. The fluorescence quenching that occurred at Dy concentrations above 2% and the decrease in fluorescence lifetime with increasing Dy concentrations were explained through cross-relaxation energy transfer processes in Dy³⁺ ions. These characteristics demonstrate that ZnS:Dy³⁺ NCs are promising luminescent materials for white light LEDs and advanced optoelectronic applications.
This paper focuses on the study of the magnetization dynamics and the magnetoimpedance of micro-sized magnetic conductors assisted by a DC current wire carrying. The research methodology combines experimental fabrication and finite element simulation, on that basis, the study explains and proposes the dependence of magnetic properties, magnetization process and magnetoimpedance various variables such as on the current magnitude and angular dependency between the external magnetic field and the micro-wire direction. These variables allow to optimize magnetoimpedance effect toward high resolution magnetic field applications. The obtained results have been discussed by considering the energy contribution including the Zeemann from the external magnetic field and the magnetic field generated by the current, shape anisotropy energy and thermal energy to the magnetization process and the magnetoimpedance effect.
One of our works, [C. T. Bich and N. B. An, Pramana – Journal of Physics 96 (2022) 33], proposed a linear optics scheme for teleporting two different types of qubits. This was achieved by using a four-particle hybrid entangled state and controlled by two controllers operating in two distinct types of Hilbert spaces: a finite-dimensional space and an infinite-dimensional space. In this work, the power of the two controllers is assessed through the analysis of the average fidelity of the teleportation protocol in their absence. It is worth noting that the controller holding a discrete-variable state consistently exhibits power that is equal to or greater than that of the controller holding a continuous-variable state.
