Search Results (211)

Nanoscale zinc sulfide (ZnS) powders have attracted considerable interest due to their unique properties and diverse applications in various fields, including wastewater treatment, optics, electronics, photocatalysis, and solar systems. In this study, nano-powder ZnS was chemically synthetized starting from Zn powder, diluted HCl, and laboratory-prepared Na2S. The obtained ZnS was studied using an SEM coupled with EDS, XRD analysis, UV–Visible spectroscopy, and FTIR techniques. The XRD results showed that the synthesized nanoscale ZnS powder was approximately 2.26 nm. Meanwhile, the EDS and XRD patterns confirmed the high purity of the obtained ZnS powder. In addition, the ZnS powder was compacted and sintered in an argon atmosphere at 400 °C for 8 h to prepare the required pellets for thin-film deposition via E-beam evaporation. The microscopic structure of the sintered pellets was investigated using the SEM/EDS. Furthermore, the optical properties of the deposited thin films were studied using UV–Visible spectroscopy in the wavelength range of 190–1100 nm and the FTIR technique. The bandgap energies of the deposited thin films with thicknesses of 111 nm and 40 nm were determined to be around 4.72 eV and 5.82 eV, respectively. This article offers a facile production route of high-purity ZnS powder, which can be compacted and sintered as a suitable source for thin-film deposition. Full article

Folic acid (FA) is used as a targeting ligand for targeted drug delivery to tumor cells, some types of which overexpress folate receptors on their surface. However, while the preparation of conjugates containing FA may comprise a multi-step process, FA presents low photostability under UV irradiation. In addition, FA undergoes radiolysis under the action of ionizing radiation, which is utilized for drug sterilization. In this study, we investigate the stability of FA in a conjugate (FA-PVP-C₆₀) with fullerene C₆₀ and polyvinylpyrrolidone under the action of UV (205–400 nm) and electron irradiation (doses from 2 to 8 kGy) at different pH (4.5, 7.2, 10.7). The degradation of FA is studied using fluorescence and UV–Vis spectroscopy. It is found that the fullerene C₆₀ in the FA-PVP-C₆₀ conjugate suppresses the degradation of FA during both photolysis and radiolysis, which is confirmed by the decrease in the quantum yield of fluorescence and the radiation chemical yield of FA destruction accompanied by increasing fullerene content in the conjugate (from 2.8 to 10 wt.%). Full article

A cheap, environmentally friendly, easily scalable post-treatment of Na-ZSM-5 (Si/Al molar ratio = 20 or 30) via electron-beam irradiation to produce hierarchical H-ZSM-5 as a propylene-increasing fluid catalytic cracking additive was performed. Higher specific surface areas and highly accessible porous systems were obtained among the irradiated samples. A combination of ²⁷Al, ¹H magic angle spinning nuclear magnetic resonance and NH₃-temperature-programmed desorption methods showed that upon irradiation, some of the framework’s tetrahedral Al atoms were removed as non-framework Al atoms via flexible coordination with Si-OH groups (either framework or non-framework defects), thus increasing the H-ZSM-5 acidity and stability during hydrothermal dealumination. The enhanced selectivity and stability toward propylene production over the irradiated H-ZSM-5 samples were attributed to the integration of the reserved population of medium acid sites into the highly accessible hierarchical network. N₂ adsorption–desorption isotherm data showed that the Si-rich H-ZSM-5 samples possessed an obvious ink-bottle-shaped micro-mesopore network and a greater degree of disordered orientation of the straight pore systems toward the exterior surfaces. Micro-activity test data suggested that with an increasing Si/Al ratio, the H-ZSM-5 additives lost some extent of their cracking activity due to the constricted hierarchical pore network toward the exterior surface but gained more stability and selectivity for propylene due to the reserved medium acid sites. Full article

This work investigates the impact of reset pulse width on multilevel conductance programming in Al₂O₃/TiO_x-based resistive random access memory. A 32 × 32 cross-point array of Ti (12 nm)/Pt (62 nm)/Al₂O₃ (3 nm)/TiO_x (32 nm)/Ti (14 nm)/Pt (60 nm) devices (2.5 µm × 2.5 µm active area) was fabricated via e-beam evaporation, atomic layer deposition, and reactive sputtering. Following an initial forming step and a stabilization phase of five DC reset–set cycles, devices were programmed using an incremental step pulse programming (ISPP) scheme. Reset pulses of fixed amplitude were applied with widths of 100 µs, 10 µs, 1 µs, and 100 ns, and the programming sequence was terminated when the read current at 0.2 V exceeded a 45 µA target. At a 100 µs reset pulse width, most cycles exhibited abrupt current jumps that exceeded the target current, whereas at a 100 ns width, the programmed current increased gradually in all cycles, enabling precise conductance tuning. Cycle-to-cycle variation decreased by more than 50% as the reset pulse width was reduced, indicating more uniform filament disruption and regrowth. These findings demonstrate that controlling reset pulse width offers a straightforward route to reliable, linear multilevel operation in Al₂O₃/TiO_x-based RRAM. Full article

The sterility of ophthalmic drugs is a fundamental requirement for ensuring patient safety, and as such, it is subject to stringent regulatory standards. However, significant gaps remain regarding the effect of sterilization techniques on the impurity profile and relative content of active pharmaceutical ingredients (API). Previous research involving a set of five APIs used in ophthalmic preparations (dexamethasone, methylprednisolone, aciclovir, tetracycline hydrochloride, and triamcinolone) demonstrated that gamma irradiation led to the formation of specific impurities in the corticosteroids, dexamethasone and methylprednisolone. This study aims to further explore the effect of both gamma and electron beam (E-beam) irradiation on the impurity profiles of these APIs under varying conditions, with and without dry ice. The analyses were conducted using high-performance liquid chromatography with ultraviolet/visible light (UV/VIS) detection and the effect of sterilization conditions was assessed in accordance with the assay and related substances test outlined in the European Pharmacopoeia (Ph. Eur.). Additionally, this study investigated whether exposure in a controlled atmosphere with reduced oxygen or water content could mitigate the formation of impurities and influence the stability of the compounds. The results indicated a protective effect of low-temperature and low-oxygen environments during both gamma and E-beam irradiation but no effect of dry conditions. Full article

The radiation sterilization of polymer-based drug solutions can change the characteristics that determine the efficiency of drug targeting, such as particle sizes in the solution and their surface potential. The effect of E-beam treatment at doses of 3 and 8 kGy in a Xe or air atmosphere on the hydrodynamic properties of dilute solutions of polyvinylpyrrolidone (PVP) conjugate with fullerene C₆₀ and folic acid (FA-PVP-C₆₀) was studied and compared with native PVP K30. The capillary viscometry method was used to determine the intrinsic viscosity of solutions. The particle sizes (R_h) were determined using the DLS method. The zeta potential of the particles was determined using the PALS method. The morphological features of the conjugate surface irradiated in a Xe atmosphere with a dose of 8 kGy FA-PVP-C₆₀ were studied by AFM. The functionalization of FA-PVP-C₆₀ and PVP during E-beam treatment was examined using UV- and FTIR-spectrometry. When the diluted solutions of FA-PVP-C₆₀ and PVP were irradiated in air with a dose of 3 kGy, destruction of polymer chains occurred predominantly, but when the dose was increased to 8 kGy, intermolecular cross-linking occurred, leading to an increase in the characteristic viscosity and particle size in the solution. It was shown that the average particle sizes, amounting to 3 and 8 nm for PVP and 4 and 20 nm for FA-PVP-C₆₀, did not change significantly under E-beam irradiation in a Xe atmosphere in the considered dose range. The zeta potential of the particles remained virtually unchanged for both PVP and FA-PVP-C₆₀ under all irradiation conditions. The obtained results indicate the possibility of performing radiation sterilization of FA-PVP-C₆₀ conjugate solutions in an inert gas atmosphere in the range of studied doses. Full article

Catalase serves as a crucial component of the antioxidant defense system by catalyzing the decomposition of hydrogen peroxide into water and molecular oxygen. This study investigated the effects of 1 MeV accelerated electron irradiation on catalase activity in model solutions at doses of 100 Gy and 1000 Gy. Enzyme activity was assessed using two complementary methods: spectrophotometric analysis and the oxygen bubble method. The experimental results demonstrated dose-dependent inhibition of catalase activity, indicating that substantial radiation-induced structural modifications may occur in the enzyme molecule as a result of irradiation. To understand the relationship between the irradiation dose and the catalase inhibition, calibration curves plotting the dependencies of hydrogen peroxide decomposition rate and the delayed appearance of oxygen bubbles after adding hydrogen peroxide to catalase saline solution on the catalase concentration showed a 1.5-fold reduction in catalase activity at 100 Gy and a 40-fold decrease at 1000 Gy. Based on these findings, we propose a novel biodosimetry approach utilizing the oxygen bubble formation delay time as an express assessment tool for detecting high radiation doses absorbed by biological objects, for example, food products. The results obtained in the study have important implications for evaluating radiation effects on biological systems, in particular catalase-containing food products, offering potential applications in radiation safety monitoring and food quality control. Full article

This study concerns the effects of the addition of crystalline nanocellulose (CNC) and ionizing radiation on the properties of cornstarch–poly(vinyl alcohol) (PVA) films. Moreover, ESR spectroscopy and gas chromatography were used for a comparison of the reactivity of CNC and two micro-sized celluloses (microfibrinal (MFC) and microcrystalline (MCC)) under the influence of irradiation. This showed that the highest reactivity of CNC was related to the lowest sizes of the particles (observed by SEM). A series of starch/PVA/CNC films characterized by a starch/PVA ratio equal to 40:60 and a CNC addition in a range from 0.5 wt% to 10.0 wt% with 30 wt% of glycerol were prepared by solution casting. The films were irradiated in a gamma chamber (in a vacuum) or in an e-beam (in the air) using a dose of 25 kGy. The mechanical properties, contact angle to water, swelling and solubility in water, moisture absorption in a humid atmosphere, and the gel content of the films were determined. The functional properties of the films strongly depended on the addition of CNC. The films formed with 1.0 wt% of CNC had the best mechanical properties and the lowest surface and bulk hydrophilicity, which could be improved further after irradiation. The results can be related to the increased homogeneity and modified distribution of the nanoparticles in the films after irradiation (as shown by SEM). Degradation is a predominant process that occurs due to irradiation; however, the crosslinking processes also have some role. The protective effect of CNC against degradation was discovered by diffuse reflectance spectroscopy. Full article

In this paper, we investigated the effects of the processing parameters, such as deposition methods, annealing temperature, and metal thickness, on the electrical characteristics of Ti/4H-SiC contacts. A reduction of the Schottky barrier height from 1.19 to 1.00 eV following an increase of the annealing temperature (475–700 °C) was observed for a reference contact with an 80 nm-thick Ti layer. The current transport mechanisms can be described according to the thermionic emission (TE) and thermionic field emission (TFE) models under forward and reverse biases, respectively. The comparison with an e-beam evaporated Ti(80 nm)/4H-SiC contact did not show significant differences for the forward characteristics, while an increase of the leakage current was observed under high reverse voltage (>500 V). Finally, a thickness variation from 10 to 80 nm induced a reduction of the Schottky barrier height, due to the reaction occurring at the interface with a Ti-Al region extended up to the 4H-SiC surface. In addition to a deeper understanding of the Schottky barrier properties, this work is useful for the development of Schottky barrier diodes with tailored characteristics. Full article

The environmental challenges posed by laboratory plastic waste, particularly single-use items, underscore the urgent need for sustainable alternatives. This study investigated the development of reusable and biodegradable labware, addressing both functional and environmental demands. The content of the biodegradable additive in the polypropylene (PP) varied from 1% to 2% by weight via twin-screw extrusion, followed by injection molding to fabricate test specimens. Three different grades of PP were also compared. Optical, mechanical, and thermal properties were systematically assessed before and after repetitive autoclave sterilization for up to 10 cycles (121 °C, 15 min, 0.11 MPa). Additionally, cytotoxicity following electron beam irradiation (E-Beam 25 and 50 kGy) was evaluated in compliance with ISO 10993-5, alongside biodegradability studies conducted under ASTM D5511 conditions. The results demonstrate that the biodegradable additive stabilized the appearance and enhanced the flexural and impact strengths of PP without compromising thermal stability, particularly after five autoclave cycles. Cytotoxicity assays confirmed the biocompatibility of the additive-modified PP, while biodegradability tests indicated moderate degradation, with 12% biodegradation achieved over 6 months compared to negligible degradation in the negative control. These findings highlight the potential of additive-modified PP as a sustainable solution for reusable labware, balancing durability with improved environmental performance and providing a viable step toward more sustainable laboratory practices. Full article

This review provides an overview of electron beam (eBeam) technology and its applications across a wide variety of disciplines. More importantly, it discusses this technology’s advantages and its benefits in developing inactivated vaccines. eBeam technology is currently being used all around the world for a variety of industrial applications, extending from food pasteurization to the cross-linking of polymers in the wire and cable industries. It is a successful emerging alternative for developing vaccines against bacterial, protozoan, and viral pathogens. This review includes a descriptive account of the mechanism of action of eBeam and how this technology achieves the complete inactivation of pathogens while retaining the integrity of their surface epitopes. This unique advantage is crucial for the production of efficacious vaccines. This review provides a detailed account of the usage of eBeam technology for developing vaccines to protect a multitude of hosts against a wide range of pathogens. eBeam-inactivated vaccines are advantageous over live vaccines, RNA/subunit vaccines, and chemically inactivated vaccines mainly due to the complete inactivation of pathogens, and the presence of intact, highly antigenic epitopes. To conclude, this article descriptively highlights eBeam technology’s advantages over other means of vaccine development. Full article

The study began by pre-sintering Ga₂O₃ powder at 950 °C for 1 h, followed by the preparation of a mixture of Ga₂O₃ and 12 at% NiO powders to fabricate a source target material. An electron beam (e-beam) system was then used to deposit NiO-doped Ga₂O₃ thin films on Si substrates. X-ray diffraction (XRD) analyses revealed that the pre-sintered Ga₂O₃ at 950 °C exhibited β-phase characteristics, and the deposited NiO-doped Ga₂O₃ thin films exhibited an amorphous phase. After the deposition of the NiO-doped Ga₂O₃ thin films, they were divided into two portions. One portion underwent various analyses directly, while the other was annealed at 500 °C in air before being analyzed. Field-emission scanning electron microscopy (FESEM) was utilized to process the surface observation, and the cross-sectional observation was primarily used to measure the thickness of the NiO-doped Ga₂O₃ thin films. UV-Vis spectroscopy was used to calculate the bandgap by analyzing the transmission spectra, while the Agilent B1500A was employed to measure the I-V characteristics. Hall measurements were also performed to assess the mobility, carrier concentration, and resistivity of both NiO-doped Ga₂O₃ thin films. The first innovation is that the 500 °C-annealed NiO-doped Ga₂O₃ thin films exhibited a larger bandgap and better electrical conductivity. The manuscript provides an explanation for the observed increase in the bandgap. Another important innovation is that the 500 °C-annealed NiO-doped Ga₂O₃ thin films revealed a high-energy bandgap of 4.402 eV. The third innovation is that X-ray photoelectron spectroscopy (XPS) analyses of the Ga_2p3/2, Ga_2p1/2, Ga_3d, Ni_2p3/2, and O_1s peaks were conducted to further investigate the reasons behind the enhanced electrical conductivity of the 500 °C-annealed NiO-doped Ga₂O₃ thin films. Full article

We present the growth of nickel oxide (NiO) thin films as a hole transport material in photovoltaic devices using the e-beam evaporation technique. The metal oxide layers were reactively deposited at a substrate temperature of 200 °C using an electron beam evaporator under an oxygen atmosphere. The oxide films reactively grown through electron-beam evaporation were optimized for carrier transport layers. Optical and structural characterizations were performed using ultraviolet–visible (UV–Vis) spectrometry, X-ray diffraction, contact angle measurements, scanning electron microscopy, and Hall effect measurements. The study of these films confirmed that the NiO layer is a suitable candidate for use as a hole transport layer based on Hall effect measurements. A morphological study using field-emission scanning electron microscopy confirmed the growth of compact, uniform, and defect-free metal oxide layers. Contact angle measurements revealed that the films possessed semi-hydrophilic properties, contributing to improved stability by repelling water from their surfaces. The stoichiometry of the films was influenced by the oxygen pressure during deposition, which affected both their morphological and optical features. The NiO films exhibited a transmittance exceeding 80% in the visible spectrum. These findings highlight the potential applications of such nickel oxide films as hole transport material layers. Full article

Polymerizable ionic liquid-based gel polymer electrolytes (PIL-GPEs) were developed for the first time using high-energy electron beam irradiation for high-performance lithium-ion batteries (LIBs). By incorporating an imidazolium-based ionic liquid (PIL) into the polymer network, PIL-GPEs achieved high ionic conductivity (1.90 mS cm⁻¹ at 25 °C), a lithium transference number of 0.62, and an electrochemical stability exceeding 5 V. E-beam irradiation enabled rapid polymer network formation within a metal-cased battery structure, eliminating the need for initiators and improving the process efficiency. In the NCM811/PIL-GPE/Li cells, PIL-GPE (8:2) delivered an initial discharge capacity of 198.8 mAh g⁻¹ with 82% retention at 100 cycles, demonstrating enhanced thermal stability and cycling performance compared to traditional GPEs. The demonstrated PIL-GPEs demonstrate strong potential for high-stability, high-performance LIB applications. Full article

This study focused on the formulation, electron beam (e-beam) crosslinking, and characterisation of hydrogels enriched with lavender oil (LO) to enhance their structural and functional properties for biomedical applications. Stable hydrogels were synthesised using water-soluble polymers and suitable ratios of Tween 80 and Isopropyl alcohol (IPA) as surfactant and co-surfactant, respectively, via e-beam irradiation at doses up to 70 kGy. The most effective crosslinking was achieved with a radiation dose of 30 kGy, depending on the concentrations of surfactants and LO. LO-enriched hydrogels exhibited enhanced superabsorbent swelling (7700% to 18,000%) and faster equilibrium rates than the control hydrogel. Structural analysis revealed a flexible spongiform porous architecture with larger mesh sizes (156 nm to 246 nm) and adequate elastic moduli (130 to 308 Pa). Degradation tests aligned with swelling data, demonstrating a degradation rate of 12% after 35 days, indicating an appropriate balance of stability and degradation. These findings suggest that e-beam technology, in conjunction with LO and surfactant addition, can effectively tailor hydrogel properties for biomedical applications, making them promising candidates for further research in wound care, drug delivery systems, and other biological applications. Full article