Flat Panel Research Articles

Impact of annealing temperature on the structural, morphological and optical properties of Ni doped ZnO nanostructured thin films synthesized by sol–gel methodology

Abstract Nickel doped zinc oxide (NZO) nanostructured thin films were prepared by hydrolysis and poly condensation reaction based on the sol–gel methodology. Nanostructured thin films were prepared over the glass substrate by dip coating. Prepared samples were annealed at 350 °C and 450 °C respectively to tune the desired characteristics. The XRD studies endorses the prepared films were polycrystalline in nature and high intensity sharp peaks were exhibited in (101) direction. EDAX results confirms the presence of Ni, Zn and O elements. FESEM results exhibits the spherical like morphology throughout the sample. The typical grain size of prepared samples are vary from 35 nm to 105 nm. Results of the FTIR divulges the different composition of prepared NZO samples. UV–vis spectrophotometer results reveals that the fabricated 1 at.% NZO thin films annealed at 450 °C were guaranteed to have the lowest absorbance of less than 10 %, while the 0.5 at.% NZO thin films have an energy band gap of roughly 3.08 eV. The obtained results of the prepared films are useful for devices like solar cells, optoelectronic devices, flat panel displays, anticorrosion and surface protection applicant against stainless steel etc.

A carbon nanotube x-ray source array designed for a new multisource cone beam computed tomography scanner

Cone beam computed tomography (CBCT) is known to suffer from strong scatter and cone beam artifacts. The purpose of this study is to develop and characterize a rapidly scanning carbon nanotube (CNT) field emission x-ray source array to enable a multisource CBCT (ms-CBCT) image acquisition scheme which has been demonstrated to overcome these limitations. A CNT x-ray source array with eight evenly spaced focal spots was designed and fabricated for a medium field of view ms-CBCT for maxillofacial imaging. An external multisource collimator was used to confine the radiation from each focal spot to a narrow cone angle. For ms-CBCT imaging, the array was placed in the axial direction and rapidly scanned while rotating continuously around the object with a flat panel detector. The x-ray beam profile, temporal and spatial resolutions, energy and dose rate were characterized and evaluated for maxillofacial imaging. The CNT x-ray source array achieved a consistent focal spot size of 1.10 ± 0.04 mm × 0.84 ± 0.03 mm and individual beam cone angle of 2.4° ± 0.08 after collimation. The x-ray beams were rapidly switched with a rising and damping times of 0.21 ms and 0.19 ms, respectively. Under the designed operating condition of 110 kVp and 15 mA, a dose rate of 8245 μGy s−1 was obtained at the detector surface with the inherent Al filtration and 2312 μGy s−1 with an additional 0.3 mm Cu filter. There was negligible change of the x-ray dose rate over many operating cycles. A ms-CBCT scan of an adult head phantom was completed in 14.4 s total exposure time for the imaging dose in the range of that of a clinical CBCT scanner. A spatially distributed CNT x-ray source array was designed and fabricated. It has enabled a new multisource CBCT to overcome some of the main inherent limitations of the conventional CBCT.

Innovations in thin‐film electronics for the new generation of displays

AbstractToday's display industry faces transistor‐level challenges similar to those of complementary metal‐oxide semiconductor (CMOS) metal‐oxide semiconductor field‐effect transistors (MOSFETs) in the mid‐1990s. Learnings from MOSFETs inform the display industry's response to the limitations of silicon‐based thin‐film transistors (TFTs). Improvements sustaining Moore's Law drove the need to rethink MOSFET materials and structures. The display industry needs fundamental innovation at the device level. New thin‐film devices enable an inflection point in the use of displays, just as fin field‐effect transistor (FinFET) defined the inflection point in CMOS in the 2000s. This paper outlines two innovations in thin‐film device technology that offers improvement in image quality and power consumption of flat panel displays: amorphous metal gate TFTs (AMeTFTs) and amorphous metal nonlinear resistors (AMNRs). Linked through a single core material set based on mass‐producible, thin‐film amorphous metals, these two innovations create near‐ and long‐term roadmaps simplifying the production of high‐image quality, low‐power consumption displays on glass (now) and plastic (future). In particular, the field‐effect mobility of indium gallium zinc oxide (IGZO) AMeTFTs (55–72 cm2/Vs) exceeds that of IGZO TFTs developed by existing display manufacturers without the need for atomic layer deposition or vertical stacking of heterostructure semiconductor films, making AMeTFTs a natural choice for the new G8.5–G8.7 fabs targeting IGZO backplanes.

Low‐Dose and Stable X‐Ray Imaging Enabled by Low‐Dimensional Dion‐Jacobson Perovskites

AbstractMetal halide perovskites have emerged as highly promising candidates for next‐generation X‐ray detectors due to their facile and low‐cost processability, high attenuation coefficient, and tunable optoelectrical properties. In this work, quasi‐2D Dion‐Jacobson (DJ) perovskites are introduced in a flat panel X‐ray imager (FPXI) for X‐ray imaging. This study demonstrates that the diammonium interlayers in DJ perovskites play a key role in enhancing structural stability, suppressing ion migration, and improving charge transport. As a result, DJ perovskite‐based X‐ray FPXIs achieve a sensitivity of 18000 µC Gyair−1 cm−2, a low detection limit of 5.7 nGyair s−1, representing performance comparable to that of state‐of‐the‐art 3D perovskite FPXIs. Thanks to the decrease in the signal crosstalk effect of the FPXIs, a high spatial resolution of 0.54 line‐pair‐per‐pixel is achieved, which is higher than that of 3D perovskite FPXIs. Remarkably, high‐quality X‐ray imaging is achieved at a total dose of 20 µGyair, which is only 1/5 of the dose typically used in commercial equipment. This work not only provides valuable insights and guidance for the fabrication of 2D DJ perovskite X‐ray detectors but also lays the groundwork for the adoption of high‐performance, stable DJ perovskite imagers as novel flat‐panel X‐ray detectors.

Efficient broadband sound absorption exploiting rainbow labyrinthine metamaterials

In this work, we demonstrate in a proof of concept experiment the efficient noise absorption of a 3D printed panel designed with appropriately arranged space-coiling labyrinthine acoustic elementary cells of various sizes. The labyrinthine unit cells are analytically and numerically analysed to determine their absorption characteristics and then fabricated and experimentally tested in an impedance tube to verify the dependence of absorption characteristics on cell thickness and lateral size. The resonance frequency of the unit cell is seen to scale approximately linearly with respect to both thickness and lateral size in the considered range, enabling easy tunability of the working frequency. Using these data, a flat panel is designed and fabricated by arranging cells of different dimensions in a quasi-periodic lattice, exploiting the acoustic ‘rainbow’ effect, i.e. superimposing the frequency response of the different cells to generate a wider absorption spectrum, covering the target frequency range, chosen between 800 and 1400 Hz. The panel is thinner and more lightweight compared to traditional sound absorbing solutions and designed in modular form, so as to be applicable to different geometries. The performance of the panel is experimentally validated in a small-scale reverberation room, and an absorption close to ideal values is demonstrated at the desired frequencies of operation. Thus, this work suggests a design procedure for noise-mitigation panel solutions and provides experimental proof of the versatility and effectiveness of labyrinthine metamaterials for tunable mid- to low-frequency sound attenuation.

Retracted: Flat Panel CT Scanning Is Helpful in Predicting Hemorrhagic Transformation in Acute Ischemic Stroke Patients Undergoing Endovascular Thrombectomy.

[This retracts the article DOI: 10.1155/2021/5527101.].

Carbon and energy balance of biotechnological glycolate production from microalgae in a pre-industrial scale flat panel photobioreactor

Glycolate is produced by microalgae under photorespiratory conditions and has the potential for sustainable organic carbon production in biotechnology. This study explores the glycolate production balance in Chlamydomonas reinhardtii, using a custom-built 10-L flat panel bioreactor with sophisticated measurements of process factors such as nutrient supply, gassing, light absorption and mass balances. As a result, detailed information regarding carbon and energy balance is obtained to support techno-economic analyses. It is shown how nitrogen is a crucial element in the biotechnological process and monitoring nitrogen content is vital for optimum performance. Moreover, the suitable reactor design is advantageous to efficiently adjust the gas composition. The oxygen content has to be slightly above 30% to induce photorespiration while maintaining photosynthetic efficiency. The final volume productivity reached 27.7 mg of glycolate per litre per hour, thus, the total process capacity can be calculated to 13 tonnes of glycolate per hectare per annum. The exceptional volume productivity of both biomass and glycolate production is demonstrated, and consequently can achieve a yearly CO2 sequestration rate of 35 tonnes per hectare. Although the system shows such high productivity, there are still opportunities to enhance the achieved volume productivity and thus exploit the biotechnological potential of glycolate production from microalgae.

Design method for eliminating spectral line tilt in a multiple sub-pupil ultra-spectral imager (MSPUI).

A multiple sub-pupil ultra-spectral imaging system designed with a single spectrometer and detector can simultaneously detect multiple-channel spectra with ultra-high spectral resolution. However, due to using a prism in the system's front end, the nonlinear dispersion introduces spectral line tilt in the imaging spectra. This phenomenon can lead to bias in the final spectral data. To eliminate this issue, we propose a new design by introducing a second prism to correct this spectral tilt in the system. The angle of spectral line tilt generated by the nonlinear dispersion of the first prism is derived. It provides the theoretical basis for characterizing the second complementary prism. Finally, a UV multiple sub-pupil ultra-spectral imaging system is designed. The system employs two pupil separation prisms and one flat panel array to segment the pupil in three channels, each operating within spectral ranges of 180∼210 nm, 275∼305 nm, and 370∼400 nm, respectively. The spectral resolutions in all three channels are better than 0.1 nm. The corrected spectral line tilt is less than 1/3 of a pixel in the two channels with pupil separation prisms. At a Nyquist frequency of 30 lp/mm, the modulation transfer functions of all three channels are greater than 0.7, ensuring imaging quality. The design results indicate that the method proposed in this paper, utilizing complementary prisms, can effectively correct the spectral line tilt caused by the nonlinear dispersion of the pupil separation prisms. This design approach can be a reference for developing multiple sub-pupil ultra-spectral imaging systems.

Vertically spliced tabletop light field cave display with extended depth content and separately optimized compound lens array.

Tabletop three-dimensional light field display is a kind of compelling display technology that can simultaneously provide stereoscopic vision for multiple viewers surrounding the lateral side of the device. However, if the flat panel light field display device is simply placed horizontally and displayed directly above, the visual frustum will be tilted and the 3D content outside the display panel will be invisible, the large oblique viewing angle will also lead to serious aberrations. In this paper, we demonstrate what we believe to be a new vertical spliced light field cave display system with an extended depth content. A separate optimization of different compound lens array attenuates the aberration from different oblique viewing angles, and a local heating fitting method is implemented to ensure the accuracy of fabrication process. The image coding method and the correction of the multiple viewpoints realize the correct construction of spliced voxels. In the experiment, a high-definition and precisely spliced 3D city terrain scene is demonstrated on the prototype with a correct oblique perspective in 100-degree horizontal viewing range. We envision that our research will provide more inspiration for future immersive large-scale glass-free virtual reality display technologies.

Lightness constancy in reality, in virtual reality, and on flat-panel displays.

Virtual reality (VR) displays are being used in an increasingly wide range of applications. However, previous work shows that viewers often perceive scene properties very differently in real and virtual environments and so realistic perception of virtual stimuli should always be a carefully tested conclusion, not an assumption. One important property for realistic scene perception is surface color. To evaluate how well virtual platforms support realistic perception of achromatic surface color, we assessed lightness constancy in a physical apparatus with real lights and surfaces, in a commercial VR headset, and on a traditional flat-panel display. We found that lightness constancy was good in all three environments, though significantly better in the real environment than on the flat-panel display. We also found that variability across observers was significantly greater in VR and on the flat-panel display than in the physical environment. We conclude that these discrepancies should be taken into account in applications where realistic perception is critical but also that in many cases VR can be used as a flexible alternative to flat-panel displays and a reasonable proxy for real environments.

Robust Perovskite X-ray Flat Panel Detector by Anisotropic Conductive Adhesive to Regulate Thermal Stress

Robust Perovskite X-ray Flat Panel Detector by Anisotropic Conductive Adhesive to Regulate Thermal Stress

Numerical Analysis of Flat Panel Composite Material for Two-Bay Crack Arrest Competency with Fractured Central Longeron

Numerical Analysis of Flat Panel Composite Material for Two-Bay Crack Arrest Competency with Fractured Central Longeron

Study on the dynamic response of aluminum‐based curved panels coated with polyurea under impact loads

AbstractMetal curved panels are commonly used in engineering structures, but they may be more susceptible to damage under impact loads compared to flat panels. Polyurea coating has been proposed as a solution to improve impact resistance. Therefore, this study investigates the impact resistance performance of curved composite panels by applying polyurea coating to aluminum‐based panels with different curvatures. First, a numerical model of polyurea‐coated aluminum composite panels was established using the finite element software LS‐DYNA, and the sensitivity of model mesh and the numerical model validity were carried out. Then, the impact resistance performance of polyurea‐coated aluminum‐based flat panels was studied from the aspects such as deformation modes and energy dissipation, and the influence of polyurea layer thickness and coating position on the impact resistance performance of polyurea‐coated aluminum composite panels was analyzed. Based on the above results, numerical models of polyurea‐coated aluminum‐based curved panels under different curvatures are further established, and the impact resistance performance of composite curved panels and the structural forms for effective protection against impact loads are comprehensively analyzed. The research results indicate that double‐sided polyurea coating is the optimal coating method for both aluminum flat panels and aluminum curved panels. After the coating thickness reaches 4 mm, there is no significant improvement in the structural impact resistance performance. The impact deformation of curved panels can be divided into four stages: dynamic buckling, plastic indentation, rebound deformation, and vibration. The concave surface has strong impact and deformation resistance, and the convex surface has strong impact resistance. The research results have important theoretical implications for the safe engineering design of protective structures using metal curved panels.

Assessing the efficacy of flat-plate solar collectors using nanofluids in the climatic context of Kirkuk city, Iraq

Solar energy is a key renewable energy source. Research and development have focused on enhancing the heat transfer coefficient, heat gain, and practical efficiency of solar systems. The aim of this study is to evaluate the performance of a flat solar panel collector using a nanofluid under conditions in the city of Kirkuk/Iraq, 35° latitude and 45° longitude, in terms of practical calculation of thermal efficiency. The study included making two solar collectors, one traditional and the other improved using a nanofluid (CuO). The CuO/Water nanofluid was prepared with a volumetric concentration of 0.25 % by mechanical mixing and then ultrasonic mixing to homogenise the particles and eliminate the agglomerations that form inside the fluid. Practical testing was conducted for the two solar collectors, one using distilled water and the other using the nanofluid, during four months (January, February, March, and April) of the year 2023. The experiments revealed that the efficiency progressively improves from 9:00 a.m. to 1:00 p.m. This increase is attributed to solar radiation’s decreasing intensity post 12:00 p.m., while thermal storage and minimised thermal losses continue to contribute. After 2:00 p.m., the efficiency dwindles due to the declining solar radiation intensity. The practical efficiency of a 0.25 % nanofluid (CuO) attains its zenith at a mass flow rate of 0.015 ls−1. Higher mass flow rates enhance heat transfer within fluid-filled tubes. The collector efficiency at this flow rate ranges from 31.66 % in January to 44.44 % in April.

Toward smart acoustic spaces: embedded machine learning for sound event detection and classification in the built environment

Edge computing integrated into the built environment will enable the development of smart acoustic spaces in which the flexural vibrations of the walls and screens that define a space may be employed to generate and monitor sound and serve as unobtrusive and convenient audio interfaces. Integration of data processing and neural decision making on compact, low- power embedded hardware-software systems will make it possible to mediate real-time, personalized acoustic interactions of a user with their environment without the need to connect to the cloud, thus providing privacy and security. In this presentation we show how embedded machine learning (ML) models combined with vibroacoustic control and monitoring of elastic panels may be employed to perform various tasks such as speech recognition, sound source localization, or the detection of acoustic signatures of specific events such as a fall or other health emergencies. The selection of vibroacoustic features, the associated signal processing requirements, and the computational resources utilized by the ML models for various acoustic tasks will be discussed. We also highlight how the distributed modal response of extended flat panels can simplify the sensing and signal processing requirements in such systems.

Plastic of Facades in the Technology of a Three-Layer Facade Panel

It is noted that the task of forming plastic facades is directly opposite to the idea of industrialization in housing construction. Each time it is a search for a balance between unification and diversity. In most cases, domestic architects and designers have to adhere to the principle of unification due to the need to comply with factory technology. A flat panel of the same type is convenient and technologically advanced. Fewer operations during equipment readjustment, fewer risks and more turnover of the formwork. As a result, the cost of construction is reduced. To overcome the negatively perceived image of a panel house, it is necessary to ensure the diversity and plasticity of facade panels, silhouette and sculpturality of three-dimensional composition, the use of projections, undercuts, recessed attic floors and terraces.

PET/SPECT/spectral-CT/CBCT imaging in a small-animal radiation therapy platform: A Monte Carlo study-Part I: Quad-modal imaging.

In spite of the tremendous potential of game-changing biological image- and/or biologically guided radiation therapy (RT) and adaptive radiation therapy for cancer treatment, existing limited strategies for integrating molecular imaging and/or biological information with RT have impeded the translation of preclinical research findings to clinical applications. Additionally, there is an urgent need for a highly integrated small-animal radiation therapy (SART) platform that can seamlessly combine therapeutic and diagnostic capabilities to comprehensively enhance RT for cancer treatment. We investigated a highly integrated quad-modal on-board imaging configuration combining positron emission tomography (PET), single-photon emission computed tomography (SPECT), photon-counting spectral CT, and cone-beam computed tomography (CBCT) in a SART platform using a Monte Carlo model as a proof-of-concept. The quad-modal on-board imaging configuration of the SART platform was designed and evaluated by using the GATE Monte Carlo code. A partial-ring on-board PET imaging subsystem, utilizing advanced semiconductor thallium bromide detector technology, was designed to achieve high sensitivity and spatial resolution. On-board SPECT, photon-counting spectral-CT, and CBCT imaging were performed using a single cadmium zinc telluride flat detector panel. The absolute peak sensitivity and scatter fraction of the PET subsystem were estimated by using simulated phantoms described in the NEMA NU-4 standard. The spatial resolution of the PET image of the platform was evaluated by imaging a simulated micro-Derenzo hot-rod phantom. To evaluate the quantitative imaging capability of the system's spectral CT, the Bayesian eigentissue decomposition (ETD) method was utilized to quantitatively decompose the virtual noncontrast (VNC) electron densities and iodine contrast agent fractions in the Kidney1 inserts mixed with the iodine contrast agent within the simulated phantoms. The performance of the proposed quad-model imaging in the platform was validated by imaging a simulated phantom with multiple imaging probes, including an iodine contrast agent and radioisotopes of 18F and 99mTc. The PET subsystem demonstrated an absolute peak sensitivity of 18.5% at the scanner center, with an energy window of 175-560KeV, and a scatter fraction of only 3.5% for the mouse phantom, with a default energy window of 480-540KeV. The spatial resolution of PET on-board imaging exceeded 1.2mm. All imaging probes were identified clearly within the phantom. The PET and SPECT images agreed well with the actual spatial distributions of the tracers within the phantom. Average relative errors on electron density and iodine contrast agent fraction in the Kidney1 inserts were less than 3%. High-quality PET images, SPECT images, spectral-CT images (including iodine contrast agent fraction images and VNC electron density images), and CBCT images of the simulated phantom demonstrated the comprehensive multimodal imaging capability of the system. The results demonstrated the feasibility of the proposed quad-modal imaging configuration in a SART platform. The design incorporates anatomical, molecular, and functional information about tumors, thereby facilitating successful translation of preclinical studies into clinical practices.

Photophysical analysis and Judd–Ofelt calculation of Eu (III) complexes: Influence of various neutral ligands on luminescent properties

This article presents the preparation and characterization of a series of four tris-β-diketonate Eu(III) complexes with formulation of [Eu(tfaa)3(L)n], tfaa denotes the 1,1,1-trifluoroacetylacetone, L to monodentate or bidentate neutral ligand with nitrogen and oxygen as donor atom and n can be 1 and 2. The characterization of synthesized complexes was done using infrared spectroscopy, thermo-gravimetric analysis and proton NMR spectroscopy. UV–vis absorption, photoluminescence as well as time-resolved luminescence spectroscopies were also employed to examine the spectroscopic features of ternary complexes. The proton NMR and IR spectral information has suggested the bonding of organic moieties to the Eu(III) ion. The chemical shift obtained for the protons of primary and secondary moieties are shifted in an opposite direction. The band gap values (optical and electronic) suggest the semiconducting nature of prepared europium complexes. The trivalent ion centered emission is shown by all the prepared complexes on excitation under UV-light. The hypersensitive peak situated at about 612 nm responsible for red emission is corresponding to 5D0→7F2 transition and found to be sensitive to the chelating environment present at around emissive ion. Red emanating europium materials have acquired significant utilization in OLEDs, flat panel displays and solid state electronics.

Evaluating how extended reality delivery device and preservice teacher major impact presence in immersive learning environments

Teacher education has begun to embrace the use of 360 videos to improve preservice teachers' (PSTs) engagement and immersion. While recent research on such use is promising overall, there are specific questions that have been left unanswered about the construct of presence in 360 videos. More specifically, research has yet to fully explore how video delivery devices and PST characteristics may impact presence. The purpose of this study was to respond to this gap in the literature by examining PST major, delivery device (ie, head mounted display vs. flat screen), and the interaction between the two in informing presence. A total of 93 PSTs watched 360 videos and then completed a questionnaire. Findings indicated that presence in head‐mounted displays was related to emotions and agency. Conversely, presence with flat screens meant familiarity and control. Moreover, PST major was a predictor of presence, suggesting that 360 videos should be personalized according to PST career and professional goals. Finally, the interaction effect of preparing to teach K‐12 mathematics and wearing a head‐mounted display had a negative and statistically significant effect on participants' perceived presence, thus indicating a non‐cumulative effect. Practitioner notesWhat is already known about this topic 360 videos are increasingly used to support preservice teacher training. 360 videos for teacher education foster immersion, presence, and noticing skills. What this paper adds Empirical evidence that 360 videos experienced with head‐mounted display facilitate agency and emotional involvement. Empirical evidence that 360 videos experienced with flat screens facilitate feelings of control. Data showed that preservice teachers' content area (math) was a positive predictor of presence in 360 videos. Implications for practice and/or policy Head‐mounted displays show promise as a delivery mode for 360 videos in teacher education. 360 videos should be personalized according to PST career and professional goals. The eXtended Reality Presence Scale is confirmed as a robust instrument to measure presence in immersive environments. More research is needed to evaluate the scalability of this approach in other contexts.

From 3G biofuels to high value-added bioproducts

The paper focused on the co-production of high-value-added product thermostable C-phycocyanin (C-PC) and biomass, further utilized in pyrolysis. The photobiosynthesis of CPC was carried out by the thermophilic cyanobacteria Synechococcus PCC6715 cultivated in the helical and flat panel photobioreactors (PBR). Despite the application of different inorganic carbon sources, both PBRs were characterized by the same growth efficiency and similar C-PC concentration in biomass. To release the intracellular C-PC the biomass was concentrated and disintegrated by the freeze-thaw method. The crude C-PC was then further purified by foam fractionation (FF), aqueous two-phase extraction (ATPE), membrane techniques (UF) and fast protein liquid chromatography (FPLC). Each of the tested methods can be used separately; however, from a practical and economic point of view, a three-stage purification system (FF, FPLC and UF) was proposed. The purity ratio of the final C-PC was about 3.9, which allows it to be classified as a reactive grade. To improve the profitability of 3G biorefinery, the solid biomass residue was used as a substrate to pyrolysis process, which leads to production of additional chemicals in the form of oils, gas (containing e.g. H 2) and biochar.