Search Results (82)

Nowadays, despite the advancements in several technological areas, the education process of various subjects shows minimal evolution from the approaches used in prior years. In light of these, some fields struggle to capture the student’s attention and motivation, in particular, when the subject addresses remote locations that students are unable to visit and relate to. Therefore, an opportunity exists to explore novel technologies for such scenarios. This work introduces an educational approach that integrates 3D Reconstruction, Virtual Reality (VR), and a Large Display to enrich Geoscience learning at the university level. In this teacher-centric approach, manipulation of virtual replicas of real-world geological sites can be performed, creating an immersive yet asymmetric collaborative environment for students in the classroom. The teacher’s VR interactions are mirrored on a large display, enabling clear demonstrations of complex concepts. This allows students, who cannot physically visit these locations, to explore and understand the sites more deeply. To evaluate the effectiveness of this approach, a user study was conducted with 20 participants from Geoscience and Computer Science disciplines, comparing the VR-based method with a conventional approach. Analysis of the collected data suggests that, across multiple relevant dimensions, participants generally favored the VR condition, highlighting its potential for enhancing engagement and comprehension. Full article

Chronic stress disrupts neuroendocrine regulation, neurotransmitter balance, and neuronal redox homeostasis, thereby contributing to the development of anxiety-related neuropathology. Arecoline, the predominant alkaloid of Areca catechu L., displays diverse neuropharmacological properties, yet its role in stress-induced emotional dysfunction has not been fully elucidated. This study examined the anxiolytic-like and neuroprotective effects of arecoline in mice exposed to chronic unpredictable mild stress (CUMS). Arecoline administration markedly improved behavioral outcomes, reflected by increased central exploration in the open-field test, prolonged time in the light compartment, and enhanced open-arm activity in the elevated plus maze. These behavioral benefits were accompanied by normalization of serum corticosterone levels, restoration of hippocampal neurotransmitters, reinforcement of antioxidant enzyme activities, and attenuation of pro-inflammatory cytokines. At the molecular level, arecoline elevated brain-derived neurotrophic factor (BDNF), tropomyosin receptor kinase B (TrkB), cAMP response element-binding protein (CREB), N-methyl-D-aspartate receptor (NMDAR), and Ca²⁺/calmodulin-dependent protein kinase II (CaMKII), indicating enhanced synaptic plasticity, while concurrently diminishing oxidative and inflammatory stress. Collectively, the findings suggest that arecoline exerts multifaceted neuroprotective actions under chronic stress by coordinating neuroendocrine modulation, neurotransmitter homeostasis, antioxidant defenses, and synaptic plasticity. This study provides new mechanistic evidence supporting the potential relevance of arecoline as a functional neuroactive compound for managing stress-induced anxiety disorders. Full article

Perovskite crystals, nanocrystals, quantum dots (QDs), and two-dimensional (2D) materials are at the forefront of optoelectronics and quantum optics, offering groundbreaking potential for a wide range of applications, including photovoltaics, light-emitting devices, and quantum information technologies. Perovskite materials, with their remarkable, tunable bandgaps, high absorption coefficients, and efficient charge transport, have revolutionized the field of light-emitting diodes, photodetectors, and solar cells. QDs, owing to their size-dependent quantum confinement and high photoluminescence quantum yields, are crucial for applications in display technologies, imaging, and quantum computing. The synthesis of QDs from perovskite-based materials yields a significant enhancement in the performance of optoelectronics devices. Furthermore, 2D perovskites have recently exhibited extraordinary carrier mobility, strong light–matter interactions, and mechanical flexibility, making them highly attractive for next-generation optoelectronic applications. Additionally, this review discusses the synergistic potential of hybrid material architectures, where perovskite crystals, QDs, and 2D materials are combined to enhance optoelectronic performance and their role in quantum optics. By analyzing the effects of material structure, surface modifications, and fabrication techniques, this review provides a valuable resource for harnessing the transformative potential of these advanced materials in modern optoelectronic applications. Full article

Background/Objectives: Projected augmented reality (PAR) enables real-time projection of digital surgical information directly onto the operative field. This offers a hands-free, headset-free platform that is universally visible to all members of the surgical team. Compared to head-mounted display systems, which are limited by restricted fields of view, ergonomic challenges, and user exclusivity, PAR provides a more intuitive and collaborative surgical interface. When paired with artificial intelligence (AI), PAR has the potential to automate aspects of surgical planning and deliver high-precision guidance in both high-resource and global health settings. Our team is working on the development and validation of a PAR platform to dynamically project surgical and anatomic markings directly onto the patients intraoperatively. Methods: We developed a PAR system using a structured light scanner and depth camera to generate digital 3D surface reconstructions of a patient’s anatomy. Surgical markings were then made digitally, and a projector was used to precisely project these points directly onto the patient’s skin. We also developed a trained machine learning model that detects cleft lip landmarks and automatically designs surgical markings, with the plan to integrate this into our PAR system. Results: The PAR system accurately projected surgeon and AI-generated surgical markings onto anatomical models with sub-millimeter precision. Projections remained aligned during movement and were clearly visible to the entire surgical team without requiring wearable hardware. Conclusions: PAR integrated with AI provides accurate, real-time, and shared intraoperative guidance. This platform improves surgical precision and has broad potential for remote mentorship and global surgical training. Full article

Conventional projection systems typically require a fixed spatial configuration relative to the projection surface, with strict control over distance and angle. In contrast, UAV-mounted projectors overcome these constraints, enabling dynamic, large-scale projections onto non-planar and complex environments. However, such flexible scenarios introduce a key challenge: severe geometric distortions caused by intricate surface geometry and continuous camera–projector motion. To address this, we propose a novel image registration method based on global dense matching, which estimates the real-time optical flow field between the input projection image and the target surface. The estimated flow is used to pre-warp the image, ensuring that the projected content appears geometrically consistent across arbitrary, deformable surfaces. The core idea of our method lies in reformulating the geometric distortion correction task as a global feature matching problem, effectively reducing 3D spatial deformation into a 2D dense correspondence learning process. To support learning and evaluation, we construct a hybrid dataset that covers a wide range of projection scenarios, including diverse lighting conditions, object geometries, and projection contents. Extensive simulation and real-world experiments show that our method achieves superior accuracy and robustness in correcting geometric distortions in dynamic UAV projection, significantly enhancing visual fidelity in complex environments. This approach provides a practical solution for real-time, high-quality projection in UAV-based augmented reality, outdoor display, and aerial information delivery systems. Full article

The application of organic light-emitting diodes (OLEDs) has become widespread, with polarizers commonly employed to mitigate the influence of external light sources on OLED displays. However, when the light signal generated by the OLED emissive layer passes through the polarizer, approximately 50% of the light energy is inevitably lost. Circularly polarized luminescent (CPL) molecules, capable of emitting specific left- or right-handed circularly polarized light, theoretically enable 100% light energy utilization in corresponding OLED devices (CP-OLEDs). With this breakthrough, CPL mechanisms exhibit significant potential for applications in data storage, bioimaging, and 3D displays. In this review, we focus on molecules constructed via a chiral perturbation strategy, analyzing their CPL generation mechanisms and molecular engineering principles. The relationship between these molecular structures and OLED performance is systematically analyzed and summarized. Finally, we critically address current challenges in developing both CPL active materials and devices based on the chiral perturbation strategies, while providing perspectives on future developments and potential challenges in this field. Full article

This study evaluates the manufacturing accuracy of Merlon fracture models produced using two vat-photopolymerization-based three-dimensional (3D) printers: digital light processing (DLP) and liquid-crystal display (LCD). The Merlon fracture model is used to assess dimensional precision and machining accuracy. The root mean square (RMS) values, wall and bottom thicknesses, and field-emission scanning electron microscopy images are analyzed. The DLP-based printers exhibit lower RMS values and superior accuracy compared with LCD-based printing and subtractive milling. Polymer-based slurries for permanent dental applications exhibit better dimensional stability than those for temporary restorations. This study also highlights the significant impact of postprocessing and cleaning procedures on the final model accuracy. These findings suggest that optimizing the postprocessing parameters is crucial for enhancing the precision of 3D-printed dental restorations. The Merlon fracture model is a viable method for evaluating additive manufacturing accuracy, contributing to the improved clinical application of vat photopolymerization in dental prosthetics. Full article

The paper presents an efficient light field image synthesis method based on single-viewpoint images, which can directly generate high-quality light field images from single-viewpoint input images. The proposed method integrates light field image encoding with the tiled rendering technique of 3DGS. In the construction of the rendering pipeline, a viewpoint constraint strategy is adopted to optimize rendering quality, and a sub-pixel rendering strategy is implemented to improve rendering efficiency. Experimental results demonstrate that 8K light field images with 96 viewpoints can be generated in real time from end to end. The research presented in the paper provides a new approach for the real-time generation of high-resolution light field images, advancing the application of light field display technology in low-cost environments. Full article

This paper starts with an overview of current methods of displaying 3D objects. Two different technologies are compared—a glasses-free 3D laptop that uses stereoscopy, and one that uses front projection on a silver impregnated fabric screen that diffracts light to achieve a holographic effect. The research question is defined—which one is suitable for use by specialists. A methodology for an experiment is designed. A scenario for finding the solution to the problem during the experiment is created. An experiment environment with different workstations for each technology has been set up. An additional reference workstation with a standard screen has been created. Three-dimensional CAD models from the field of mechanical engineering were chosen. Different categories of defects were introduced to make the models usable for the scenario—finding the defects in each of the different workstations. A survey for participant feedback, using several categories of questions, was created, improved, and used during the experiment. The experiment was completed, short discussions were held with each participant, and their feedback was analyzed. The categories of the participants were discussed. The results from the experiment were discussed and analyzed. Statistical analysis was performed on the survey results. The applicability of the experiment in other fields was discussed. Conclusions were made, and the comparative advantages and specifics of each technology were discussed based on the analysis results and the experience gained during the experiment. Full article

Background: Implant surgical guides manufactured in-house using 3D printing technology are widely used in clinical practice to translate virtual planning to the operative field. Aim: The present in vitro study investigated the dimensional changes of 3D surgical guides printed in-house using Shining 3D surgical guide resin (SG01). Materials and methods: Five test bodies, varying in shape and dimensions, were designed using computer-aided design (CAD) software and manufactured using three different Light Crystal Display (LCD) 3D printers (AccuFab-L4D, Elegoo Mars Pro 3, and Zortrax Inspire). Specific printing and post-processing parameters for the SG01 resin were set to produce 25 test bodies (5 of each shape) from each of the three printers, resulting in a total of 75 samples. The dimensional changes were evaluated using a digital calliper at four different time points: immediately after printing (T0), one month after storage (T1), immediately after sterilization (T2), and one month after sterilization (T3). Results: All the test bodies showed deviations from the overall CAD reference value of 12.25 mm after printing and post-processing (T0) and following steam sterilization (T2). Similar trends were observed for the effect of storage times at T1 and T3. The AccuFab prints demonstrated a better dimensional stability than the Elegoo and Zortrax samples. Conclusions: The LCD 3D printers, sterilization, and storage times influenced the dimensional stability of the test bodies made with SGO1 resin. Full article

Background: Grapefruit seed skin particles (GSSPs) have antifungal properties due to the presence of flavonoids. Therefore, it has the potential to display antifungal characteristics when added to acrylic resin, but it could affect the mechanical properties of the resin. This study investigated the effects of adding GSSPs on the mechanical characteristics of 3D-printed denture base resins. Purpose: The aim of the present study was to determine the effects of the addition of GSSPs to 3D-printed acrylic at different concentrations on the degree of conversion (DC), surface hardness, flexural strength, and tensile strength. Methods: In this study, 90 samples were printed with acrylic resin via a Digital Light Processing (DLP) printer. Thirty square samples were used for the surface hardness test. Thirty rectangular samples were used for the flexural strength test, and thirty dumbbell-shaped samples were used for the tensile strength test. These materials were prepared by adding different concentrations of GSSPs (0.0 wt.%, 5.0 wt.%, and 7.0 wt.%), which were determined by a pilot study to be the most effective in 3D denture base resins. The Durometer Shore Hardness Scale (DSHS) was used to measure the surface hardness, and a universal testing machine was employed to gauge the flexural strength and tensile strength. Field emission scanning electron microscopy (FE-SEM) was employed for particle size analysis and fracture behavior determination. Results: Compared with those of the control group, the degree of conversion (DC), surface hardness, flexural strength, and tensile strength of the treated groups significantly improved after the addition of 5.0 wt.% and 7.0 wt.% GSSPs. The FE‒SEM images revealed a decrease in porosity as the concentration of GSSPs increased with a brittle fracture behavior. Conclusions: The addition of GSSPs to 3D-printed acrylic is recommended because of their significant positive impacts on the mechanical properties of 3D-printed denture base resin. Full article

Enhancing the energy efficiency of thermal systems reduces their consumption, lowers costs, and reduces undesired environmental impact, thus making these systems more sustainable. The current work introduces a passive method for heat transfer enhancement that is carried out using natural convection by nanofluid. This work introduces a computational study of the process of natural convection within a square cavity containing Cu/H₂O nanofluid. The cavity wall on the left side undergoes partial isothermal heating, while the opposing side is fully cooled isothermally, with all other boundaries maintained adiabatic. A mathematical model formulated based on a 2-D model was used to provide the solution for the system of governing equations of mass, momentum, and energy conservation, employing the finite element technique. A commercial CFD package is utilized to perform the computational simulation. The present investigation delves into the impact of the Rayleigh number, nanoparticle concentration, heater length, and heater location on the flow field and heat transfer characteristics. The model outcomes were displayed for a wide range of the pertinent parameters as 103 ≤ Ra ≤ 106, 0.25 ≤ l_h ≤ 1.0, 0.125 ≤ h_c ≤ 0.875, and 0.02 ≤ ϕ ≤ 0.10. Also, correlation equations relating the average Nusselt number to these crucial parameters are derived. These equations are simple and can be applied in practice easily in many fields, such as electric and electronic equipment cooling and thermal management of heat sources. Also, these equations gather all the parameters that affect the heat transfer process. They are shedding light on the intricate interplay between these parameters in the natural convection heat transfer process. Full article

A light-field display with a near-virtual-image mode, which employs both a lens array and an aperture array, was previously proposed to provide a wide viewing zone angle and bright three-dimensional (3D) images. However, it is desirable to enhance its resolutions, which are presently equal to those of conventional displays. Thus, we proposed a technique for increasing the resolutions of 3D images generated by the light-field display with the near-virtual-image mode. The gap between the flat-panel display and lens array is reduced to decrease the magnification of the virtual images of the pixels and to enable the observation of multiple virtual pixel images through each lens. Further, we imaged the aperture array using the lens array to eliminate the gaps between the multiple pixels observed through adjacent lenses. We constructed a prototype display based on the proposed technique and verified the increase in the resolution of the prototype display compared to the original near-virtual-image light-field display. Full article

Naked-eye 3D micro-LED display combines the characteristics of 3D display with the advantages of micro-LED. However, the 3D micro-LED display is still at the conceptual stage, limited by its intrinsic emission properties of large divergence angle and non-coherence, as well as difficulties in achieving large viewing angles with high luminous efficiency. In this work, we propose a double-layer metasurface film integrating functions of collimation with multiple deflections, constituting a micro-LED naked-eye 3D display system. The system is characterized through numerical simulations using the 3D finite-difference time-domain method. The simulation results show that the double-layer metasurface film restricts 90% of the emitted light of the micro-LED to the vicinity of the 0° angle, improving its spatial coherence. Subsequently, a large-angle, low-crosstalk outgoing from −45° to 45° is achieved, while providing a deflection efficiency of over 80% and a pixel density of up to 605. We believe this design provides a feasible approach for realizing naked-eye 3D micro-LED displays with a large field of view, low crosstalk, and high resolution. Full article

Lead-free Mn²⁺-based metal halide materials are now being considered as clean candidates for backlight displays and lights due to the d–d transition, diverse components, and environmental friendliness. Therefore, efficient and stable Mn²⁺-based metal halide phosphors are in great demand for practical applications. In this work, adopting the mixed-ligand strategy, a series of [(CH₃)₄N]_2−x[(C₂H₅)₄N]_xMnCl₄ phosphors were synthesized by mechanochemical process. With the increase molar ratio of (CH₃)₄N/(C₂H₅)₄N, the phase of phosphors is transformed from orthorhombic to tetragonal. Compared to [(CH₃)₄N]₂MnCl₄ and [(C₂H₅)₄N]₂MnCl₄ phosphors, the mixed-ligand strategy significantly boosts the green emission intensity of Mn²⁺-based metal halide phosphors. The obtained [(CH₃)₄N][(C₂H₅)₄N]MnCl₄ phosphors exhibit a high photoluminescence quantum yield (PLQY) of 83.78% under 450 nm excitation, which is attributed to the modulation of the adjacent [MnCl₄]₂- distance by using the different chain length of organic cations, effectively suppressing non-radiative recombination. Additionally, the [(CH₃)₄N][(C₂H₅)₄N]MnCl₄ phosphors exhibit a green emission at 516 nm, narrow full width at half-maximum (FWHM) of 45.53 nm, and good thermal stability. The constructed white light-emitting diode (WLED) device exhibits a wide color gamut of 108.3% National Television System Committee, demonstrating the suitability of the [(CH₃)₄N][(C₂H₅)₄N]MnCl₄ phosphors as a green emitter for WLED displays and lightings. This work provides a new way to modulate the PL performance of manganese-based metal halides for application in the optoelectronic field. Full article