Flat Panel Research Articles

Effect of Exposure to Blue Light from Electronic Devices and the Mediterranean Diet on Macular Pigment

Objective: To explore the effect of time exposure to flat screen electronic devices with LED lighting and the Mediterranean diet on macular pigment optical density (MPOD). Methods: In this cross-sectional observational study, the MPOD was measured by heterochromatic flicker photometry in 164 eyes (47 of younger women aged 20–31 and 35 of older women aged 42–70). Exclusion criteria: evidence of macular degeneration and eyes with cataracts. Data on the use of electronic devices and Mediterranean diet adherence were collected through a survey. Nonparametric analysis of variance and independent sample t-tests were used to compare subjects. Results: Significant differences (p < 0.01) were found in total time of exposure to LEDs (hours per day) between both groups (9.31 ± 3.74 younger women vs. 6.33 ± 3.64 older women). The MPOD values for the younger and adult populations were significantly different: 0.38 ± 0.16 and 0.47 ± 0.15 (p < 0.01), respectively. When comparing both groups for the same time of exposure to LEDs, differences were obtained between MPOD values of both populations: For total exposures greater than 6 h per day, the MPOD values were lower in younger women than in adult ones (0.37 ± 0.14 vs. 0.50 ± 0.14, p < 0.01). On the other hand, a significantly higher adherence was found in the older women in comparison with the younger women (OW 9.23 ± 2.50 vs. YW 7.70 ± 2.08, p < 0.01), with higher MPOD values (OW (0.52 ± 0.14) vs. (YW (0.34 ± 0.18). Conclusions: Higher MPOD values are observed with decreasing exposure time to electronic devices with LED lighting screens and higher adherence to the Mediterranean diet.

CONVERGENCE OF THE METHOD OF PIECEWISE LINEAR APPROXIMATIONS AND COLLOCATIONS FOR A TWO-DIMENSIONAL HYPERSINGULAR INTEGRAL EQUATION ON A SET WITH BOUNDARY

A hypersingular integral equation on a convex bounded set on the plane with an integral understood in the sense of a finite part in the sense of Hadamard is considered. Equations of this type, in particular, arise when solving the Neumann boundary value problem for the Lapalse and Helmholtz equations on a flat screen in the case where the solution is sought in the form of a double layer potential. To numerically solve the equation, a numerical scheme is used based on piecewise linear approximation of the unknown function on a triangular conformal mesh and the collocation method. The uniform convergence of numerical solutions to an exact solution on a grid when the maximum cell diameter tends to zero has been proven.

High-Performance Perovskite Flat Panel X-Ray Imagers via Blade Coating.

Perovskite X-ray detectors are recognized as the most promising candidates for low-dose detectors due to their superior performance. However, it is still full of challenging in the fabrication of flat-panel X-ray imagers (FPXIs), primarily due to the absence of large area thick films that exhibit high uniformity and long-term performance stability. A general synthesis route is urgently needed to grow large-scale halide perovskite thick films directly on a pixeled thin-film transistor (TFT) backplane with high uniformity, closing the gap between the great potential of perovskite X-ray detectors and their entry into the market. In this work, an advanced precursor paste suitable for blade coating is developed to enable high-throughput manufacturing of FPXIs. Highly uniform perovskite films with a thickness of 300-micrometers are directly deposited onto pixeled TFT substrates by the blade-coating method using the above paste, which governs a stable dark current and minimal noise of the X-ray detectors. As a result, (BA)2(MA)9Pb10I31 perovskite X-ray detectors achieved a high sensitivity of 15200 µC Gyair -1 cm-2 and a limit of detection (LoD) of 26.8 nGyair s-1. Moreover, FPXIs with a spatial resolution of 0.95 lp mm-1 (0.475 lp pixel-1) are obtained, which exhibits negligible signal crosstalk and excellent X-ray imaging performance.

Associations Between Serum Indium Levels and Preserved Ratio Impaired Spirometry Among Non-Smoking Industrial Workers: A Nationwide Cross-sectional Study in Taiwan

BackgroundIndium, a rare heavy metal, extensively used in flat panel display manufacturing, poses potential respiratory health risks to workers. Preserved ratio impaired spirometry (PRISm), a term describing nonobstructive lung function abnormalities, is associated with adverse health outcomes. Despite known risks, the relationship between serum indium levels and PRISm remains underexplored. MethodsA cross-sectional cohort study among non-smoking industry workers potentially exposed to indium in Taiwan was conducted in 2020. Demographic data, and pulmonary function tests were collected comprehensively. Serum indium levels were quantified using inductively coupled plasma mass spectrometry, and respiratory symptoms were obtained via questionnaire. PRISm was defined as FEV1/FVC ≥ 0.7 with FEV1 < 80% predicted. Univariate, and multivariate logistic regression analyses were conducted to identify risk factors associated with PRISm. ResultsAmong 2,575 eligible participants, those with abnormal serum indium levels (≥3 ng/mL) were older, predominantly male, and had longer total working duration. PRISm prevalence was significantly higher in individuals with abnormal indium levels (22.7% vs. 7.6%). PRISm subjects exhibited a higher proportion of abnormal indium levels. Multivariate analysis revealed that serum indium levels ≥3 ng/mL and female sex were significant risk factors for PRISm after adjusting sex, age, body mass index and working duration. ConclusionThis study demonstrates a significant association between elevated serum indium levels and increased PRISm prevalence among non-smoking workers in Taiwan. Findings highlight the importance of assessing serum indium levels in occupational health surveillance and revising exposure standards to mitigate respiratory health risks associated with indium exposure.

Control of turbulent coherent structures on flat panel by porous medium

Due to the unique internal structure of porous medium, the disturbance to the boundary layer involves both changing the dynamic behavior of the physical quantity in the conservation equation and changing the boundary conditions. In order to investigate the effect and mechanism of porous medium on the coherent structure near the wall of a flat panel, particle image velocimetry experiments of a flat panel and a flat panel with porous medium were carried out in a low turbulence return flow wind tunnel. The coherent structures of flat panel and porous medium-laden flat panel were compared in the study. The flow-normal plane flow display results show that porous medium can significantly lower the near-wall flow velocity, lift up the vortex structure in the near-wall region, reduce the vorticity, and effectively reduce the shear stress. Meanwhile, the velocity statistical quantities were extracted and fitted using the velocity profile method to show that at a wind velocity of 5.8 m/s and a porosity of 10 pores per inch (ppi), the maximum resistance reduction rate reaches 23.1%. The flow-spanwise plane flow display results show that the porous medium can destroy large-scale streak structures.

First linac-mounted photon counting detector for image guided radiotherapy: Planar image quality characterization.

Image guided radiotherapy (IGRT) with cone-beam computed tomography (CBCT) is limited by the sub-optimal soft-tissue contrast and spatial resolution of energy-integrating flat panel detectors (FPDs) which produce quasi-quantitative CT numbers. Spectral CT with high resolution photon-counting detectors (PCDs) could improve tumor delineation by enhancing the soft-tissue contrast, spatial resolution, dose-efficiency, and CT numberaccuracy. This study presents the first linac-mounted PCD. On the journey to developing spectral cone-beam CT for IGRT, the planar image quality of a linac-mounted PCD is first fundamentally characterized and compared to an FPD in terms of the 2D spatial resolution, noise, andcontrast. A Medipix3RX-based PCD was mounted to the kV FPD of an x-ray volume imaging (XVI) system on an Elekta linac and the PCD acquisition was synchronized with the pulsed kV source. The energy calibration of the Medipix3RX was determined with various radioisotope gamma emissions up to 60 keV. To compare the 2D spatial resolution and noise between the PCD and FPD, the pre-sampling modulation transfer function (MTF) and normalized noise power spectrum (NPS) were measured using an RQA5 spectrum and a fluoroscopy phantom was imaged to determine the limiting resolution of line pairs. Spectral planar images of phantom inserts containing two different concentrations of calcium (60 and 240 mg/cc) and iodine (5 and 15 mg/cc) were optimally energy weighted to maximize the contrast using tube voltages of 60, 80, 100, and 120 kV. To account for drifts in the sensor temperature, the PCD was dynamically translated in and out of the insert shadow during acquisitions to obtain flat field corrections per frame. The raw contrast of the resultant planar images was compared to the energy-integrating FPD. The energy calibration of the Medipix3RX was observed to be linear up to 60 keV. The limiting resolution observed on the fluoroscopy phantom was 2 lp/mm for the FPD and 5 lp/mm for the PCD. The pre-sampling MTF was higher across all frequencies comparing the PCD to the FPD. The normalized NPS of the PCD did not vary with frequency, whereas the spectrum for the FPD decreased monotonically and was lower than the PCD noise power across most of the spatial frequency range studied due to optical light spreading. Optimal energy weights were applied to the dynamically acquired PCD images and the raw contrast of the 60 mg/cc calcium insert increased by factors of and at 60 and 120 kV respectively compared to theFPD. A Medipix3RX-based PCD was successfully integrated with the kilovoltage imaging system on an Elekta linac. The initial planar image quality characterization indicated improvements in the MTF and energy-weighted contrast compared to the FPD. Future work will focus on obtaining linac-mounted spectral CBCT images with a translate-rotate geometry, however this initial study indicates that variations in the PCD sensor response during acquisitions must be addressed to realise the full potential of linac-mounted spectralCBCT.

Innovative and Efficient Three-Dimensional Design Strategies for Optimizing the Industrial Production of Knitted Footwear

Three-dimensional knitted uppers for footwear enhance ergonomic properties and fit compared to conventional flat panels. The knitting process for these elements represents a bottleneck in footwear production because flat-knitting machines must knit the uppers individually, which limits production capacity. This study explores ways to optimize knitting processes for 3D uppers. The focus is on reducing production time while maintaining product quality, ensuring a precise fit, and minimizing material waste. A series of experiments conducted on a base sneaker model implemented techniques to streamline knitting operations. These techniques were later adapted to other footwear types, including ankle boots, loafers, and sandals, to meet the unique requirements of each design. These optimizations include replacing traditional operations, such as overlocking or stitch decreases, with more efficient methods, such as open loops, as well as eliminating costly-to-manufacture elements. The results show significant reductions in production time while maintaining the fit and functional integrity of the uppers. These findings demonstrate both the technical feasibility and economic impact of these optimizations, offering valuable insights for the large-scale adoption of knitting technology in the footwear industry.

Research Progress and Applications of Benzocyclobutene‐Based Functional Polymers

AbstractBenzocyclobutene (BCB) stands out as a compound of remarkable structural distinction, featuring a thermodynamically stable benzene ring coupled with a kinetically dynamic four‐membered ring. This unique structure allows for ring‐opening reactions under specific conditions, leading to the formation of crosslinking products. The primary initiation for the ring‐opening of the four‐membered ring in BCB is heat, although mechanical stress and light exposure can also trigger this transformation. This ability has catapulted it to prominence in the field of polymer material development. It has spurred the creation of a vast array of polymers that incorporate BCB groups either in their main chains or side chains, showcasing BCB's extensive applicability as a crosslinking agent. Additionally, BCB‐based polymers (BCB polymer) exhibit a suite of desirable properties, such as exceptional dielectric characteristics, chemical and thermal resilience, minimal thermal expansion, and low moisture uptake. These attributes render them particularly suitable for a range of applications, including electronic packaging, silicon‐based photonic integration, flat panel display technology, biomedical devices, and beyond. This paper delves into the various methods of inducing ring‐opening crosslinking in BCB, summarizes the recent advancements in performance enhancement of BCB polymer materials, and examines their wide applications in different fields.

Detection of Defects in Polyethylene and Polyamide Flat Panels Using Airborne Ultrasound-Traditional and Machine Learning Approach

This paper presents the use of noncontact ultrasound for the nondestructive detection of defects in two plastic plates made of polyamide (PA6) and polyethylene (PE). The aim of the study was to: (1) assess the presence of defects as well as their size, type, and orientation based on the amplitudes of Lamb ultrasonic waves measured in plates made of polyamide (PA6) and polyethylene (PE) due to their homogeneous internal structure, which mainly determined the selection of such model materials for testing; and (2) verify the possibilities of building automatic quality control and defect detection systems based on ML based on the results of the above-mentioned studies within the Industry 4.0/5.0 paradigm. Tests were conducted on plates with generated synthetic defects resembling defects found in real materials such as delamination and cracking at the edge of the plate and a crack (discontinuity) in the center of the plate. Defect sizes ranged from 1 mm to 15 mm. Probes at 30 kHz were used to excite Lamb waves in the slab material. This method is sensitive to the slightest changes in material integrity. A significant decrease in signal amplitude was observed, even for defects of a few millimeters in length. In addition to traditional methods, machine learning (ML) was used for the analysis, allowing an initial assessment of the method’s potential for building cyber-physical systems and digital twins. By training ML models on ultrasonic data, algorithms can distinguish subtle differences between signals reflected from normal and defective areas of the material. Defect types such as voids, cracks, or weak bonds often produce distinct acoustic signatures, which ML models can learn to recognize with high accuracy. Using techniques like feature extraction, ML can process these high-dimensional ultrasonic datasets, identifying patterns that human inspectors might overlook. Furthermore, ML models are adaptable, allowing the same trained algorithms to work on various material batches or panel types with minimal retraining. This combination of automation and precision significantly enhances the reliability and efficiency of quality control in industrial manufacturing settings. The achieved accuracy results, 0.9431 in classification and 0.9721 in prediction, are comparable to or better than the AI-based quality control results in other noninvasive methods of flat surface defect detection, and in the presented ultrasonic method, they are the first described in this way. This approach demonstrates the novelty and contribution of artificial intelligence (AI) methods and tools, significantly extending and automating existing applications of traditional methods. The susceptibility to augmentation by AI/ML may represent an important new property of traditional methods crucial to assessing their suitability for future Industry 4.0/5.0 applications.

Evaluation of a compact cone beam CT concept with high image fidelity for point-of-care brain imaging.

Cone beam computed tomography (CBCT) has potential advantages for developing portable, cost-effective point-of-care CT systems for intracranial imaging, such as early stroke diagnosis, hemorrhage detection, and intraoperative navigation. However, large volume imaging with flat panel detector based CBCT significantly increases the scattered radiation fluence which reduces its image quality and utility. To address these issues, a compact CBCT concept with enhanced image quality was investigated for intracranial imaging. The new system features a novel antiscatter collimator and data correction method to address the challenges in imaging large volumes with CBCT. A benchtop CBCT prototype was constructed. Imaging studies with anthropomorphic phantoms showed that soft tissue visualization, Hounsfield Unit (HU) accuracy, contrast, and spatial resolution increased significantly with the proposed CBCT concept, and they were comparable to the values measured in the gold standard multidetector-row CT (MDCT) images. Contrast-to-noise ratio (CNR) in CBCT images was within 12-31% of the CNR in MDCT images. These findings indicate that a compact CBCT system integrated with effective scatter suppression techniques may have increased utility in the context of brain imaging, and the proposed approach may enable the development of point-of-care CT systems for head imaging based on flat panel detector based CBCT technology.

Comprehensive image quality comparison of conventional and new flat panel detectors under bedside chest radiography beam conditions.

Recently, a novel wireless flat-panel detector with auto-exposure control has become available. This study aimed to elucidate the potential advantages of the new detector over conventional detectors through a comprehensive analysis of the physical image quality characteristics. Measurements were conducted on two models: new (720C) and conventional (710C) versions; this assessment was performed by assuming the beam quality for bedside chest radiography, utilizing a portable device for X-ray exposure. The detective quantum efficiency (DQE) was computed based on the presampled modulation transfer function (MTF) and normalized noise power spectrum. The validity of the DQE results was verified through the visualization of the analog blurring components and a detailed analysis of the noise components. The spatial frequency at which the presampled MTF value reached 10% was 5.2 cycles/mm for 720C and 3.9 cycles/mm for 710C. The full width at half-maximum of the spatial spreading of analog components was estimated at 0.09mm for 720C and 0.14mm for 710C by the visualization. Regarding the DQE, 720C was superior under low-dose conditions despite no significant differences being observed under high-dose conditions. The new detector demonstrated superior resolution characteristics compared with the conventional detector and an improvement in the DQE under low-dose conditions. However, similar to the conventional detector, a significant dose dependence caused by a structural factor was confirmed for the DQE. These results suggest the existence of an appropriate dose range for maximizing detector performance and provide insights crucial for optimization tasks in the X-ray imaging.

UTHP spectrometer: an ultra-thin and high-performance imaging spectrometer for ocean color remote sensing in broadband

The principle of ocean color detection involves using satellite sensors to capture variations in received signals, which are subsequently analyzed to infer the concentrations of various components responsible for ocean color changes. In recent years, significant research advancements have been achieved, centered on the development of ocean color detectors and the analysis of the resulting data. We have developed an innovative ultra-thin high-performance (UTHP) scanning imaging spectrometer for ocean color remote sensing across the near ultraviolet-visible-near infrared (NUV-VIS-NIR) spectrum. This spectrometer overcomes the bulkiness of conventional equipment by integrating a waveguide platform that replaces traditional optical elements with a single flat glass panel, featuring curved surfaces and high-reflectivity coatings to perform essential optical functions. We believe this to be a novel design that greatly reduces the size and weight of the device, making it highly suitable for deployment on various platforms, including aircraft and satellites. The optical system underwent extensive testing, including simulations using Zemax software and physical prototyping, achieving a spectral resolution of less than 3 nm across the 400-1000 nm waveband while maintaining low distortion. The UTHP spectrometer’s compactness, lightweight design, and exceptional performance mark a significant advancement in imaging spectrometry, with the potential to transform remote sensing by providing more efficient, accessible methods for studying expansive oceanic regions.

Cold Cathode Flat Panel X-ray Source for Talbot–Lau Grating Interferometer using Zinc Oxide Nanowire Field Emitter Arrays and Periodic Microstructured Anode

Cold Cathode Flat Panel X-ray Source for Talbot–Lau Grating Interferometer using Zinc Oxide Nanowire Field Emitter Arrays and Periodic Microstructured Anode

Intraoperative Position System guided with Augmented Reality Improves the Learning Curve of Endovascular Navigation in Endovascular Naïve Operators

ObjectiveThis study aimed to compare the completion of gate cannulation task performed by participants of varying experience using fluoroscopy, the Intra-Operative Positioning System (IOPS) – an FDA-cleared endovascular navigation system that has been developed to reduce dependence on fluoroscopy – or an investigational augmented reality electromagnetic navigation technology based on IOPS. MethodsThe task consisted in the cannulation of the gate of a GORE Excluder AAA endoprosthesis bifurcated aortic stent graft (W.L. GORE & Associates, Flagstaff, AZ USA) deployed into a 3D printed abdominal aortic aneurysm (AAA) model connected to a 7000 MDX flow pump (Sarns Inc/3M, Ann Arbor, MI USA) reproducing physiological conditions. The procedure was performed in a hybrid operating room (GE Allia IGS 7). Each participant performed the cannulation task with fluoroscopy, standard IOPS guidance with flat screen display (IOPS-FS), and the investigational IOPS with augmented reality headset (IOPS-AR), in a randomly assigned order. All participants used the same sensorized guidewire and steerable 6Fr catheter during their three cannulation tasks. A total of 26 participants were classified in three groups of experience: Group 1 (endovascular naïve; n = 13), Group 2 (surgeon in training; n = 12) and Group 3 (one expert surgeon). Primary endpoints included cannulation time and technical success, which was defined as the advancement of the catheter over the guidewire within the main body of the aortic stent graft within a maximum 15 minutes cutoff time for each trial. ResultsIn group 1, the mean cannulation time was shorter using IOPS-AR versus fluoroscopy (4.3 ±4.4 min vs 7.1±4.9 min; P=.04), but not statistically different when comparing IOPS-FS and fluoroscopy (6.3±4.5 min vs 7.1±4.9 min; P=.63). In group 1, technical success was 77% with fluoroscopy and 92% with both IOPS-FS and IOPS-AR (P=.59). In group 2, although there was no significant difference between cannulation time amongst the three different endovascular approaches, there was a trend towards shorter cannulation times with IOPS-FS or IOPS-AR as compared to fluoroscopy (mean time of 2.5±0.9, 4.4±4.0 and 5.2±4.5 min, respectively). In group 2, technical success was 92% with fluoroscopy and 100% with both IOPS-FS and IOPS-AR (P>.99). The expert vascular surgeon repeated the cannulation task four times for each endovascular approach, with 100% technical success and no difference in mean cannulation time between the imaging modalities (P=.89). ConclusionsAugmented reality allows for reducing the gate cannulation time as compared to fluoroscopy in participants with no previous exposure to any endovascular procedure. This suggests that augmented reality can be beneficial for individuals early in their career and can mitigate the learning curve. As individuals become experts, their ability to adapt to different endovascular modalities increases, eliminating the learning curve altogether.

Quantum-mechanical understanding on structure dependence of image potentials of single-walled boron nitride nanotubes

Abstract The recent discovery of field emission devices based on one-dimensional nanostructures has attracted much interest in emerging applications on next-generation flat panel displays, molecule-based sensors, and so forth. To achieve a comprehensive understanding of surface potentials at the nano-emitters during the tunneling process, in this study we systematically investigated the image potentials of single-walled boron nitride nanotubes with different edges, diameters and lengths in the frame of a composite first-principles calculation. The image potentials of zigzag single-walled boron nitride nanotubes are found to be dependent on the non-equivalent sides. Only the image potentials of isolated armchair single-walled boron nitride nanotube can be well fitted with the image potential of an ideal metal sphere of a size comparable to the tube diameter. On the contrary, the image potentials of zigzag and grounded armchair single-walled boron nitride nanotubes exhibit a strong length-dependence characteristic and are significantly different from that of an ideal metal sphere, which originates from the significant axial symmetry breaking of induced charge at the tip for the long tube. The correlation between the testing electron and electronic structure of single-walled boron nitride nanotube has also been discussed.

Resolution Improvement in Near-Virtual-Image-Mode Light-Field Display Using Resolution-Priority Technique

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.

Benefits of front coating crystalline scintillator screens for phase-contrast synchrotron micro-tomography.

Transparent crystalline scintillators such as cerium-doped YAG or LuAG are widely used in X-ray imaging for the indirect detection of X-rays. The application of reflective coatings on the front side to improve the optical gain is common practice for flat panel detectors with CsI or Gd2O2S powder scintillators but still largely unknown for crystalline scintillators such as LuAG. This work shows experimentally and quantitatively how a black and reflective coating on the X-ray side of a 2 mm LuAG:Ce scintillator improves the image quality compared to a 2 mm LuAG:Ce scintillator without a coating. The measurements have been done for two different distances, with 2 m and 29.7 m on the BM18 beamline of the European Synchrotron. The Modulation Transfer Function (MTF) and the Signal-to-Noise-Ratio (SNR2) power spectrum as well as contrast-to-noise ratio are used for comparing image quality. Propagation-based phase contrast strongly enhances the SNR2 amplitudes (gain ≈10 from 2 m to 29.7 m object-detector distance) of the raw images' spectrum independent of the scintillator coating. For both detector positions, the reflective coating is able to raise SNR2 by up to 80% through the improved optical gain, while black coating does the opposite (decrease SNR2 by 20%) with respect to no coating. With the tested optical setups, changes in MTF /sharpness between the coatings are minor. Comparing CNR2 in CT scans of a multi-material sample, in this case an electric motor, we observe the reflective coating yielding better material contrast for plastic and air. Application and effect of Wiener-deconvolution, along with Paganin-type phase retrieval, are also discussed in the context of CT image quality.

AC thin-film electroluminescence: A historical overview with a look ahead

50 years ago, television screens used bulky cathode ray tubes (CRTs) with a size limited to about 70 cm in diagonal (28 in.), while flat panel displays belonged to the realm of science fiction. Although the performance of CRTs in terms of energy consumption, size, and color rendering slowly improved, there were numerous applications where flat panel displays would present a tremendous advantage, notably for confined spaces and in portable equipment. Starting from the 1970s, AC thin-film electroluminescence (ACTFEL) was investigated as a high performance alternative to the—also emerging—liquid crystal displays (LCDs) and plasma display panels (PDPs). For a number of years, ACTFEL developed from the phase of fundamental research to commercial products (for monochrome displays) and full color prototype displays. However, due to the fast development and strong cost reduction of LCDs, ACTFEL did not remain competitive and most of the research activities were ceased. The current overview sketches a brief history of the ACTFEL technology, its merits and limitations, and the reasons why such displays still have their use in some niche applications.

Performance of spherical and flat solar cells under different environmental conditions

This study investigates the performance degradation of spherical and flat solar modules due to dust accumulation. To isolate the effect of dust, both modules were subjected to identical environmental conditions, including irradiance, temperature, and humidity. The results reveal a significant reduction in power efficiency as dust density increases, with a nearly linear relationship observed. Spherical solar modules exhibited a minor decrease in efficiency (±3.64%) compared with flat solar modules (±5.46%) under increased dust density, consistent with prior research. Dust accumulation affects solar cells by causing dust deposition, light scattering, and temperature rise. Flat solar panels are more susceptible to dust accumulation due to their larger surface area, which attracts more dust particles. In contrast, spherical cells’ smaller surface area minimises dust build-up, making them less prone to efficiency loss. The study also examined the impact of solar intensity and tilt angle on efficiency. Spherical cells demonstrated greater resilience in varying light conditions and tilt angles, maintaining efficiency across a wider range of scenarios than flat panels. These findings emphasise the importance of considering dust accumulation when designing and maintaining solar panels, with spherical modules offering advantages in dusty environments and under changing sunlight conditions.

Rod‐Like Microcrystal Scintillators Based on Organic–Inorganic Hybrid Copper Halides for X‐Ray Imaging

AbstractCopper‐based organic–inorganic hybrid halides (OIHHs) have garnered significant interest in X‐ray imaging due to their flexible structural adjustability, efficient light emission, strong X‐ray absorption, etc. Herein, four copper‐based OIHH crystals composed of the same organic ligands (isopropyl triphenylphosphonium cations, IPP+) and inorganic parts (Cu2I42−) are synthesized by varying the ratios of raw materials and types of reaction solvents. Although these crystals share identical structures, they exhibit different luminescent behaviors (blue, green, white, and yellow) attributed to vacancy defects originating from CuI. Notably, the novel copper‐based OIHH (CP2) with green emission shows the best luminescence efficiency (99.54%) and excellent scintillation performance (50675 photons MeV−1). The traditional technology of scintillation screens mixing scintillator powders and polymers often results in light scattering due to powder aggregation and inhomogeneity. To address this challenge, the dispersant polyvinyl pyrrolidone is introduced to prepare uniform rod‐like microcrystals of CP2. The scintillation screen based on CP2 microcrystals achieves a high spatial resolution of 16–18 lp mm−1, surpassing the resolution of most copper‐based OIHH scintillators. Furthermore, it is imaging capabilities are validated using a commercial X‐ray flat panel detector, demonstrating imaging performance comparable to that of commercial scintillators.