ZnS semiconductor quantum dots (QDs) co-doped with Er3+ and Sm3+ ions were successfully fabricated using a wet chemical method. The presence of Er3+ and Sm3+ in the ZnS host was confirmed using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). XRD and transmission electron microscopy (TEM) analyses showed that the QDs had a zinc blende (ZB) structure with spherical shape and a particle size of approximately 4 nm. The optical properties of ZnS QDs were investigated by changing the Er3+ ion concentration and fixing the Sm3+ ion concentration. Judd-Ofelt (J-O) intensity parameters were determined from optical absorption spectra. The obtained J-O parameters illustrate the covalency related to the ligands and rare-earth ions. The radiative transition probabilities (Ar), branching ratios (βr), and radiative lifetimes (τr) of various excited states of the Er3+ ions were calculated. For the first time, the energy transfer (ET) processes from the ZnS host to Er3+ ions and from Er3+ to Sm3+ ions were confirmed and explained in detail. Er3+ and Sm3+ co-doped ZnS QDs showed a very long lifetime (up to milliseconds) compared to undoped ZnS. This exciting property has potential applications in photocatalysis, biosensing, and photovoltaics.

The successful synthesis of two-dimensional (2D) lateral heterostructures has created new promising architecture design in materials science and device physics. However, this materials group has received much less attention in comparison with the vertical heterostructures. Therefore, efforts should be made in order to explore more lateral heterostructures for practical applications. In this work, novel lateral heterostructures formed from MoSO and WSO monolayers are investigated. The AIMD simulations and phonon dispersion curves indicate their good stability once formed. Calculations assert their indirect gap semiconductor character, whose band gap is found between those of the pristine monolayers. The chemical bonds are predominantly ionic as results of the charge transfer from Mo-W atoms to S-O atoms, demonstrated by the electron localization function and Bader charge analysis. Nevertheless, the electronic hybridization may suggest also significant covalent character. The studied 2D materials exhibit good absorption properties with a wide absorption band spreading from visible regime to ultraviolet regime and large absorption coefficient of the order of 105/cm. Finally, the effects of different balanced and unbalanced numbers of building blocks on the formation process and electronic structure are also examined. Results presented herein may introduce new alternatives for the lateral heterostructures based on graphene and transition metal dichalcogenides, which may find potential applications in optoelectronic devices.

In this work, we present the synthesis and characterization of molybdenum oxide (MoO3) nanoparticles (NPs). The MoO3 NPs were coated on silicon (Si) wafer to fabricate n-MoO3/p-Si diode by the spin coating method. X-ray diffraction (XRD) profiles clearly show the crystalline nature of all specimens with an orthorhombic crystal system. Stretching and bending vibrations of molybdenum-oxygen were confirmed by the Fourier transform infrared analysis. The maximum absorbance was observed for MoO3 NPs prepared from Nitric acid (HNO3). Nano flakes like morphology were seen by scanning electron microscopy (SEM), and elemental dispersion spectral analysis approved expected Mo and O elements in the final product. Transmission electron microscopy (TEM) analysis of the as-prepared samples indicates a single-phase orthorhombic crystal structure. Electrical conductivity results show that synthesized samples are having semiconducting behavior. It is noted that the p–n junction diode prepared with Hydrochloric acid (HCl) has better rectifying behavior with lower ideal factor (n) values of 2.47 than the other sample.

Recently, 2D Janus structures containing oxygen have attracted great attention from researchers. Herein, the ZrXO (X = S and Se) Janus monolayers are investigated using first-principles calculations based on the projector augmented wave (PAW). ZrSO and ZrSeO single layers are dynamically and thermally stable, and exhibit the indirect gap semiconductor character with a bandgap of 1.91(2.88) and 1.09 (1.88) eV, respectively, as determined by the standard PBE (hybrid HSE06) functional. The charge transfer process from Zr atom to IVA-atoms is confirmed by means of the charge density difference and Bader population analysis. Studied 2D materials exhibit good absorption in a wide energy range from visible to ultraviolet regimes with larger absorption coefficient reaching to the order of 105 cm−1. To magnetize the ZrXO monolayers for possible spintronic applications, fluorine (F) and chlorine (Cl) doping is proposed. Significant magnetic properties with total magnetic moments ≈1 μB are obtained. Besides, high spin polarization around the Fermi level is also induced as a result of the feature-rich half-metallic or magnetic semiconductor natures. Results presented herein introduce ZrSO and ZrSeO monolayers as prospective 2D materials to be applied high-performance nano optoelectronic and spintronic devices.

We report two patients presenting with sensorimotor neuropathy without cerebellar ataxia, spasticity and other neurological features, being diagnosed with intermediate form CMT by electrophysiological and clinical examination and neuroimaging. By whole-exome sequencing panel of two affected members, and PCR Sanger on NEFH and SACS genes to confirm the presence of selected variants on their parents, we identified a novel missense variant NEFH c.1925C>T (inherited from the mother) in an autosomal dominant heterozygous state, and two recessive SACS variants (SACS c.13174C>T, causing missense variant, and SACS c.11343del, causing frameshift variant) (inherited one from the mother and another from the father) in these two patients. Clinical and electrophysiological findings on these patients did not match classical ARSACS. To the best of our knowledge, this is the first case report of two affected siblings diagnosed with CMT carrying both a novel NEFH variant and biallelic SACS variants.

Recently, several countries have made commitments to move to a net-zero emission by the year 2050 in a response to climate change. Among various renewable energy systems to realize the target, wind energy system has been gaining much attention as a favorable alternative source to fossil fuel energy. In particular, many floating offshore wind turbines (FOWT) are expected to be installed because of vast installation resources without water depth limit conditions, stable and strong wind resources, relatively low constraints on noise emission, and space restriction compared to onshore wind turbines. In this study, a 10 MW superconducting floating offshore wind turbine was modeled with a 1/90 scale ratio and was experimentally tested at the Ocean Engineering Widetank of the University of Ulsan. The model calibration of the scaled model was performed with free decay test and showed a good correlation with simulation results calculated from FAST V8 of NREL. The motion characteristics of the 10 MW superconducting FOWT semi-submersible type platform was investigated under regular waves and irregular waves through the comparison of model test data and simulation results. The study on the motion characteristics of the model showed that the simulation considering the 2nd order wave effects to hydrodynamic forces and moments provided better accuracy close to the model test data.

In the framework of the 3-3-1 model with neutral leptons, we investigate lepton-flavor-violating sources based on the Higgs mass spectrum, which has two neutral Higgs identified with the corresponding ones of the two-Higgs-doublet model. We note that at the  scale of the LHC, the parameter space regions satisfy the experimental limits of  decays. These regions depend heavily on the mixing of exotic leptons but are predicted to have large  signals. We also show that  can reach a value of .

Dilute ethylene (C2H4) was removed in a novel plasma reactor comprising multiple honeycomb monoliths consisting of up to four PdO/ZSM-5/monolith catalysts. These monoliths were packed in a tubular reactor separated by mesh electrodes alternatively grounded or connected to a high voltage (HV) power source. The effect of the number of monoliths on the discharge power, adsorption, and removal of C2H4 was investigated. Additionally, the influence of the energy input, C2H4 inlet concentration, and gas flow rate on the C2H4 abatement was examined. The adsorption capacity, C2H4 conversion, and energy efficiency were observed to increase as the number of monoliths increased. The effect of the palladium (Pd) loading technique, namely ion exchange (IE), incipient wetness impregnation (IM), and combined IE-IM, IE followed by IM, on the C2H4 adsorption was also studied. The combined IE-IM method presented an exceptional adsorption capacity of ∼136 µmol/gcatalyst under humid conditions despite nonpolar nature of C2H4. C2H4 removal was performed via both continuous and cycled storage-discharge (CSD) plasma-catalytic oxidation processes. The CSD process was conducted in two ways: with intermittent C2H4 feed (CSD-IEF) and with maintained C2H4 feed (CSD-MEF), both comprising intermittent plasma discharge. Intriguingly, the performance of the CSD-MEF process was superior (56 J/L, 1.61 g/kWh) to that of the CSD-IEF (119 J/L, 0.98 g/kWh), and continuous process (∼228 J/L, 0.53 g/kWh) in terms of energy efficiency as well as the overall simplicity of the system.

In this work, a new direct gap semiconductor, the Na2S monolayer in the 1H-phase, with good stability and ionic character, has been explored using first-principles calculations. A Γ–Γ energy gap of 0.80 (1.48) eV is obtained using the standard PBE (hybrid HSE06) functional. The studied two-dimensional (2D) material possesses weak dynamical stability under compressive strain due to the sensitivity of the ZA mode. Meanwhile tensile strain has much more positive effects, where the stability is well retained up to a strain strength of 7%. Once external strain is applied, the band gap increases due to switching from lattice compression to lattice tension. Further exploration of defect engineering indicates that significant magnetism with magnetic moment of ±1 is induced by a single Na vacancy. The magnetic properties are mainly produced by S atoms around the defect site. In contrast, the paramagnetic nature is preserved with a single S vacancy. However, large energy gap reduction of up to 93.75% can be achieved with a defect concentration of 25%. This research introduces a new prospective 2D material similar to transition metal dichalcogenides for optoelectronic and spintronic applications, contributing to the continued efforts to develop novel multifunctional low-dimensional materials.

We perform spin-polarized first-principles calculations to study the electronic and magnetic properties of the CrN (111) surface considering different surface terminations. We evaluate their thermodynamic stability employing the surface formation energy formalism. According to the calculations, the N-terminated and Cr-terminated surfaces are stable under N-rich and Cr-rich environments, respectively. At intermediate conditions the Octopolar N-terminated, and the α-(2×2) Cr-terminated reconstructions are stable. The ideal surfaces show metallic phase. In contrast, surface reconstructions yield half metallic characteristics, induced by the Cr vacancies, and the charge rearrangement. Spin density isosurfaces show a ferromagnetic alignment in the first bilayer, and an antiferromagnetic ordering in the inner bilayers for N-terminated and reconstructed surfaces. On the other hand, the Cr-terminated surface shows a C-type antiferromagnetic behavior. In addition, a magnetic alignment change is found from C-type antiferromagnetic to A-type antiferromagnetic, when a tensile strain is applied on the surface. Our results show how to manipulate the properties of the surfaces to become suitable for spintronic applications.