Light Window Research Articles

High‐Throughput Screening of Heterogeneous Transition Metal Dual‐Atom Catalysts by Synergistic Effect for Nitrate Reduction to Ammonia

AbstractNitrate reduction to ammonia has attracted much attention for nitrate (NO3‐) removal and ammonia (NH3) production. Identifying promising catalyst for active nitrate electroreduction reaction (NO3RR) is critical to realize efficient upscaling synthesis of NH3 under low‐temperature condition. For this purpose, by means of spin‐polarized first‐principles calculations, the NO3RR performance on a series of graphitic carbon nitride (g‐CN) supported double‐atom catalysts (denoted as M1M2@g‐CN) are systematically investigated. The synergistic effect of heterogeneous dual‐metal sites can bring out tunable activity and selectivity for NO3RR. Amongst 21 candidates examined, FeMo@g‐CN and CrMo@g‐CN possess a high performance with low limiting potentials of ‐0.34 and ‐0.39 V, respectively. The activities can be attributed to a synergistic effect of the M1M2 dimer d orbitals coupling with the anti‐bonding orbital of NO3‐. The dissociation of deposited FeMo and CrMo dimers into two separated monomers is proved to be difficult, ensuring the kinetic stability of M1M2@g‐CN. Furthermore, the dual‐metal decorated on g‐CN significantly reduces the bandgap of g‐CN and broadens the adsorption window of visible light, implying its great promise for photocatalysis. This work opens a new avenue for future theoretical and experimental design related to NO3RR photo‐/electrocatalysts.

Slow light effect caused by optomechanically induced transparency in multimode optomechanical system

Owing to the radiation pressure, the cavity optomechanical system can couple the optical field with the mechanical resonator, so the state of the mechanical resonator can be regulated through the optical field. Conversely, the optical field in the optomechanical system can also be regulated by modulating the mechanical element. Therefore, many interesting optical phenomena, such as Fano resonance, optomechanically induced absorption and amplification, and optomechanically induced transparency, can be generated in a cavity optomechanical system. Especially in transparent windows, both absorption and dispersion properties change strongly, which results in extensive applications such as slow light and optical storage. Because of its ultra-high quality factor, small size, mass production on chip and convenient all-optical control, it provides an ideal platform for realizing slow light engineering. In this work, by solving the Heisenberg equation of motion of a multimode optomechanical system composed of an optical cavity and two mechanical oscillators, and then by using the input-output relationship for the cavity, the intensity of probe transmission can be obtained. Taking the experimental date as realistic parameters, the behaviors of probe transmission in different detuning conditions are presented. By controlling the pump power under blue detuning, the probe transmission undergoes a process of optomechanically induced absorption to parametric amplification, and the critical pump power is obtained. In the case of red detuning, optomechanically induced transparency, Fano resonance and phase dispersion of the system are studied, and the results of different mechanical coupling strengths, frequency relations and detuning are compared. The numerical results show that as the mechanical coupling strength between two mechanical oscillators increases, the splitting distance becomes larger, and a larger coupling strength ratio will result in a larger splitting peak width. By controlling the frequency relationship between the two resonators, the probe transmission spectra undergo a series of transitions from Fano resonance to optomechanically induced transparency. Because the transmission window of the probe light is accompanied by rapid phase dispersion change, it will lead to group delay. The slow light effect caused by optomechanically induced transparency is further discussed, and the propagation of fast and slow light can be controlled by pump-cavity detuning. The optical delay in this system can be in the order of milliseconds. The multimode optomechanical system based on array structure has a potential application prospect in slowing and storing light pulses.

A novel Co1.29Ni1.71O4/glycerolate-derived oxygen-vacancies-containing TiO2 composite for highly efficient photocatalytic hydrogen evolution

Charge separation and migration is still a big challenge for photocatalysis. Constructing heterojunction interface structure is a useful way to improve charge separation efficiency. Here, a novel glycerolate-derived n-type TiO2 with oxygen vacancies was hybridized with Co1.29Ni1.71O4 by a facial ultrasonication method to achieve such a purpose. The optimized 2.5 % Co1.29Ni1.71O4/TiO2 hybrid showed a photocatalytic hydrogen evolution rate of 1685 μmol g−1 h−1 under 365 nm LED light irradiation, 26.7-fold higher than that of pure TiO2 (63 μmol g−1 h−1). Besides, the hydrogen production amount kept a linear increase with the increase of irradiation time for the 2.5%Co1.29Ni1.71O4/TiO2 catalyst during a 24 h-long continuous hydrogen release test, confirming the excellent catalytic stability. Detailed characterizations demonstrated that Co1.29Ni1.71O4 nanosheet was closely contacted with TiO2 nanoparticles, which increases specific surface area and widens the light absorption window of TiO2. Moreover, Co1.29Ni1.71O4 addition facilitated highly efficient separation of photogenerated carriers and prolongs lifetimes of the excited electrons. First principles calculations confirmed that there existed strong interaction between Co1.29Ni1.71O4 and TiO2 in the composite, and electrons were directly transferred from Co1.29Ni1.71O4 to TiO2 at the interface by the Ni-O and Co-O pathway. All of these leaded to a high photocatalytic hydrogen evolution activity for the Co1.29Ni1.71O4/TiO2 composite. This work revealed Co1.29Ni1.71O4 to be a promising heterojunction counterpart material and able to promote photocatalysis through unique cross-boundary charge transfer.

A STUDY OF VISUAL PRIVACY ON OPENINGS IN RESIDENTIAL LIVING SPACES

The purpose of this study is to examine the relationship between “visibility from inside” and “estimated visibility from outside” and the factors that affect “visibility from inside” in various lighting environments and windows in order to predict visual privacy. From the results of experiments in actual housing complex and the laboratory, it was found that the linear relation between “visibility from inside” and “estimated visibility from outside” was established for all types of window treatment. The relationship is unaffected by lighting condition, window shape, or evaluation position. However, this relationship is only valid when the outdoor illuminance ≥ indoor illuminance.

Wildflower phenological escape differs by continent and spring temperature

Temperate understory plant species are at risk from climate change and anthropogenic threats that include increased deer herbivory, habitat loss, pollinator declines and mismatch, and nutrient pollution. Recent work suggests that spring ephemeral wildflowers may be at additional risk due to phenological mismatch with deciduous canopy trees. The study of this dynamic, commonly referred to as “phenological escape”, and its sensitivity to spring temperature is limited to eastern North America. Here, we use herbarium specimens to show that phenological sensitivity to spring temperature is remarkably conserved for understory wildflowers across North America, Europe, and Asia, but that canopy trees in North America are significantly more sensitive to spring temperature compared to in Asia and Europe. We predict that advancing tree phenology will lead to decreasing spring light windows in North America while spring light windows will be maintained or even increase in Asia and Europe in response to projected climate warming.

Effects of indoor lighting conditions and window views on occupants’ well-being and behavior: a systematic review.

This paper reviews 49 studies that addressed how window view, daylighting, and lighting in buildings affect occupants’ behavior and well-being. The systematic literature search was performed in November 2021 and focused on office and educational buildings. We quantified the number of papers per study type, study aim, and lighting condition. Predictor categories and methods for data collection were also considered. We analyzed the results according to a structure of records, defined by the number of predictors and type of outcomes from a study. We obtained 106 records. A gap in the number of studies under different lighting conditions and building types was identified. Studies under natural light and studies conducted in learning environments were fewer than studies dealing with artificial lighting in offices. A wide variety of methods for data collection was found. Artificial lighting features and correlated color temperature were the most used predictors. Based on the analysis of records, we found that 61.3% of the associations between predictors and outcomes were statistically significant. The type of effect was not reported in 3.8% of the records-meaning that approximately 35% of the records found no significant associations between predictors and outcomes.

Scattered-light uniformity imager for diagnosing laser absorption asymmetries on OMEGA.

Light scattered from a target is the most-direct measurement for diagnosing laser absorption in a direct-drive implosion. Observations from OMEGA implosions show much larger scattered-light asymmetries than predictions. A new instrument has been developed to absolutely measure the scattered-light intensity and nonuniformity for the purpose of diagnosing the asymmetry. The scattered-light uniformity imager (SLUI) diagnostic records the variation in scattered-light intensity over a transmission diffuser using a charge-coupled device (CCD)/lens assembly. At the standard operating position, an 11.3° (f/2.5) cone of light is collected. A stray light baffle, debris shield, and antireflection absorbing filter are also incorporated into the diagnostic payload inserted into the target chamber. The imaging parts of the diagnostic (light baffle, vacuum window, filters, lens, and CCD camera) are located outside the target chamber. Five SLUIs have been built and deployed in OMEGA's ten-inch manipulator diagnostic ports, covering almost 5% of the emission surface, enabling an absolute scattered-light measurement should be within a few percent of the global average. Each SLUI system is calibrated offline, providing absolute scattered-light intensity measurements. Based on the measured point spread function, each diffuser plate image contains over 20 000 independent scattered-light absolute-intensity measurements of the variation over the collection cone. SLUI provides a platform to study scattered light and absorption asymmetries, and their possible sources.

Improved light transmission in nanocrystalline aluminum nitride (AlN)—Enabling a lightweight, thermal shock resistant transparent ceramic

Optically transparent ceramics were traditionally only viable using optically isotropic materials and limited birefringent materials with small Δn such as alumina (Δn≈0.008). Thus heavily birefringent materials such as AlN (Δn≈0.045), polycrystalline ceramics are usually not considered for optical applications due to their high scattering loss, despite its exceptionally appealing thermal conductivity, mechanical stiffness/toughness and relatively low density—attributes that are ideal for light weight optical windows for harsh environments. To further improve the transparency over coarse grain AlN ceramics that have been reported, subwavelength grain size is desired. Here we present significant improvements in visible, NIR and mid-IR transparency in AlN ceramics by reducing the average grain size to 230 nm. A newly developed, non-carbon thermal reduction for producing clean powders at low temperatures is key to the success. The nanocrystalline AlN ceramics reach full density at a densification temperature as low as 1500 °C and showed an in-line transparency of over 55% at 2.5 μm and over 70% in the mid-IR which is the highest transparency in AlN ceramics reported. The successful demonstration of transparent nanocrystalline AlN ceramics makes it the ideal choice for optical windows in quickly fluctuating temperature environments where weight is a consideration such as air and space vehicles.

The Role of Light Shelf and Window Size on Daylight Performance of an Architecture Studio

Daylight affects our health and comfort. Recently, occupants face thermal and visual comfort problems due to the lack of solar control elements and improper design decisions of glazed surfaces. Recent studies show that solar control systems and window-based variables are some of the most significant variables which influence daylight performance. This study aims to test various combinations of window sizes and light shelf scenarios for a uniform distribution of daylight and visual comfort of occupants in two architecture studios in the İzmir Institute of Technology (IZTECH) Campus. In scenarios; window size and location, exterior and interior light shelves’ height, incline angle, and materials are tested. It is concluded that variables significantly improved the uniform distribution of daylight of both studios and sun patch areas of the south/east-oriented studio. Also, the artificial light requirement of the south/west-oriented studio is improved by 29.36% and 31.75% for the 21st of June and December respectively.

Double-Side Selective Spectral Response Organic Photodetectors for Demultiplexing Optical Signals.

Selective spectral response photodetectors (PDs) capable of accurately capturing the color of images have broad applications in industry and academia. Here, we demonstrate filter-free, wavelength-selective detection organic photodetectors (OPDs) with two distinct response ranges and having the planar bilayer heterojunction device structure by employing either a (semi-)transparent anode or a cathode as the incident light window. The resultant OPDs exhibit a responsivity of 51 mA W-1 in the range 300-650 nm and 11 mA W-1 in the range 650-850 nm under top illumination condition. Similarly, the devices show a responsivity of 2 mA W-1 for the short-wavelength region and 131 mA W-1 for the long-wavelength region when under bottom illumination condition, indicating a high responsivity ratio that meets the requirements for selective detection. Hence, our individual device not only works in either visible or NIR range but also provides narrowband detection with spectral widths down to 100 nm in the NIR range. The working mechanism of spectral selectivity is identified through quantitative analysis of the external quantum efficiency (EQE) spectra using optical modeling when compared to the OPDs with bulk heterojunction structure, thus clarifying the general validity of the device design concept. Finally, our OPDs can demultiplex intermixed optical signals from the light-communication system successfully. Our results should inspire new studies on the device design concept and new applications of OPDs.

In Situ Growth of High-Quality CsPbBr3 Quantum Dots with Unusual Morphology inside a Transparent Glass with a Heterogeneous Crystallization Environment for Wide Gamut Displays.

All-inorganic CsPbBr3 perovskite quantum dots (QDs) are considered to be one of the most promising green candidates for the new-generation backlight displays. The pending barriers to their applications, however, lie in their mismatching of the target window of green light, scalable production, susceptibility to the leaching of lead ions, and instability in harsh environments (such as moisture, light, and heat). Herein, high-quality CsPbBr3 QDs with globoid shapes and cuboid shapes were in situ crystallized/grown inside a well-designed glass to produce nanocomposites with peak emission at 526 nm, which not only exhibited photoluminescence quantum yields of 53 and 86% upon 455 and 365 nm excitation, respectively, but also have been imparted of high stability when they were submerged in water and exposed to heat and light. These characteristics, along with their lead self-sequestration capability and easy-to-scale preparation, can enable breakthrough applications for CsPbBr3 QDs in the field of wide color gamut backlit display. A high-performance backlight white LEDs was fabricated using the CsPbBr3 QDs@glass powder and K2SiF6:Mn4+ red phosphor, which shows a color gamut of ∼126% of the NTSC or 94% of the Rec. 2020 standards.

67‐4: Research on Design and Lamination of 180° Curly CG

OLED display occupies a dominant position in the smartphone market, and how to improve the screen share is an important pursuit of major terminals. On the other hand, because the display needs to reserve windows for front light sensing devices, the integrity of the display is difficult to achieve. Considering the flexible advantages of OLED display, this paper designs a 180 ° surround Cover Glass (CG) that cancels the front light sensing device and improves the proportion of mobile phone display area and screen, and studies some technical problems of 180 ° surround CG bonding with the display, including bonding process selection, bonding trajectory optimization and film material selection and design.

Analysis of radiation energy between light source, optical window and cryogenic sample

The cryogenic mechanical properties of materials are particularly important in cryogenic engineering fields. The digital image correlation technique is a method to measure strain and displacement with high precision without contact. The optical window is necessary for DIC technology to obtain the cryogenic mechanical properties of materials. However, the thermal radiation energy between the light source, the glass and the sample greatly affects the limit temperature of the cryogenic mechanical measurement. In this paper, the spectral radiation properties of the glass and sample surfaces for the wavelength of 0.38-25 μm were measured. The thermal radiation energy between the power density emitted by the light source, the radiation energy emitted by the glass surface and the radiation energy emitted by the sample were analyzed. Finally, the effects of illumination distances on the radiation energy density and the sample temperature were studied. The results indicate that the power density emitted by the light source accounts for the main part of the radiant energy density received by the sample, and the radiant energy on the glass and the sample surface are negligible. Moreover, increasing the illumination distance is effective to reduce the radiation energy and temperature rise of the sample.

Scintillator tile batch test of CEPC AHCAL

Hadron calorimeter (HCAL) is an essential sub-detector of the baseline detector system for Circular Electron Positron Collider (CEPC). We plan to build an Analog Hadron CALorimeter (AHCAL) prototype based on the Particle Flow Algorithm (PFA). The AHCAL of CEPC uses steel as the absorber and scintillator tiles read out by Silicon Photo-Multipliers (SiPMs) as the sensitive medium. The energy linearity and resolution of the calorimeter depend on the light yield uniformity of the sensitive medium. It is essential to qualify the entire detector production in order to select scintillator tiles with the uniformity of light yield within 10%. An automated batch test platform has been designed with 144 channels and an automated 3D servo motor. The paper summarizes the tests performed on more than 15000 scintillator tiles, and the SiPMs work at 59 V (overvoltage: 5 V). The measured light yield, corrected for the set-up response non-uniformity, is around 12.9 p.e. About 91.6% of scintillators (14219 pieces) are qualified within 10% of the light yield window.

Energy Conservation Measures and Value Engineering for Small Microgrid: New Hospital as a Case Study

Energy conservation measures can not only improve energy efficiency; it can also enhance microgrid resilience. This paper aims at investigating energy conservation in a small microgrid, using a new hospital in Riyadh city as a case study, to satisfy the Saudi Building Code (SBC part 601) requirement of energy conservation as the first case. The second case study aims to apply and simulate additional advanced energy conservation requirements. The new hospital has considered energy conservation measures uch as upgraded Heating, Ventilation, and Air Conditioning (HVAC), lighting type effect, thermal insulation, and window material. These energy conservation considerations made a difference in the annual energy saving and efficiency of its microgrid. This study used Autodesk Revit software to obtain building information modeling (BIM) and eQUEST to perform energy simulations. The two software programs are integrated together to perform comprehensive energy simulations with detailed building information from the model by Autodesk Green Building Studio (GBS). The energy conservation measures mainly focused on energy management and saving in the building’s electrical installations. All utilized equipment in the hospital should follow the Saudi standards issued by the national authorities. The simulation results revealed a noticeable annual energy saving of up to 19.82% for the second case, using a great thermal resistance building envelope, energy-saving lighting system, and highly rated Energy Efficiency Ratio (EER) HVAC system compared to the first case. More than 100,000 SR in yearly energy saving was achieved by implementing the second case study. Applying the Value Methodology (VM) to the proposed hospital in this study saved more than 700,000 SR in the initial cost of the hospital.

Injectable Optical System for Drug Delivery, Ablation, and Sampling in Deep Tissue

AbstractPhotothermal therapy is becoming one subject of intense investigation for cancer treatment. However, due to the light absorption and light scattering of skin tissues, it is challenging to directly transport light energy into subcutaneous tissues with a depth over 1.0 cm. This research puts forward a technique termed as Injectable Optical System (IOS) for guiding near‐infrared light (NIR) into deep tissues by optical fibers, which is unattainable by regular NIR photothermal therapy, despite that NIR light is testified as the preferred light window with deepest tissue penetration. Meanwhile, the technique of IOS also possesses the abilities of drug delivery and synchronous sampling the diseased tissues during the treatment of photothermal therapy. According to in vitro and in vivo studies, IOS exhibits distinct advantages in transporting light energy into deeper subcutaneous tissues in contrast with traditional light irradiation on skins. Light would directly transport through the pathway to tumor tissues to realize hyperthermia effect without causing energy loss. Since IOS owns the benefits of clinical biopsy and radiofrequency ablation, it would be a powerful supplement to therapeutic methodologies for treating subcutaneous diseases. The easy modification of IOS offers great promise to combine other analytical techniques to achieve the in situ detection and deep‐sited tumors treatment.

Impacts of light direction and window properties on students’ perceptual evaluations in design studios

This study aimed to determine how light direction, window proximity and window dimensions could affect students' perceptual evaluations in design studios. The design studios of the Nuh Naci Yazgan University in Kayseri were selected as the research setting. The ‘semantic differential scale’ composed of 10 adjective pairs was used for determining subjects’ perceptual evaluations of design studios having two different window dimensions. According to the results obtained, when making drawings, right-handed students who received light from a window on the left side were determined to perceive the physical environmental factors of design studios more positively compared to students who received light from a window on the right side. In addition, students sitting near a window in design studios were observed to generally perceive the physical environmental factors more positively than those sitting in the middle close to the window, in the middle away from the window and inside. Furthermore, students who sat in an area with floor to ceiling window were determined to perceive the place more positively compared to those who sat in an area with parapet to ceiling window. These results generally confirmed that light direction, window proximity and window dimensions in design studios are effective on students’ perceptual evaluations.

An amalgamation of YOLOv4 and XGBoost for next-gen smart traffic management system.

The traffic congestion and the rise in the number of vehicles have become a grievous issue, and it is focused worldwide. One of the issues with traffic management is that the traffic light’s timer is not dynamic. As a result, one has to remain longer even if there are no or fewer vehicles, on a roadway, causing unnecessary waiting time, fuel consumption and leads to pollution. Prior work on smart traffic management systems repurposes the use of Internet of things, Time Series Forecasting, and Digital Image Processing. Computer Vision-based smart traffic management is an emerging area of research. Therefore a real-time traffic light optimization algorithm that uses Machine Learning and Deep Learning Techniques to predict the optimal time required by the vehicles to clear the lane is presented. This article concentrates on a two-step approach. The first step is to obtain the count of the independent category of the class of vehicles. For this, the You Only Look Once version 4 (YOLOv4) object detection technique is employed. In the second step, an ensemble technique named eXtreme Gradient Boosting (XGBoost) for predicting the optimal time of the green light window is implemented. Furthermore, the different implemented versions of YOLO and different prediction algorithms are compared with the proposed approach. The experimental analysis signifies that YOLOv4 with the XGBoost algorithm produces the most precise outcomes with a balance of accuracy and inference time. The proposed approach elegantly reduces an average of 32.3% of waiting time with usual traffic on the road.

Application of Photocatalytic Nanomaterials in Photoelectrochemical Biosensors

Recently, photoelectrochemical (PEC) biosensors are becoming the rising star in biosensing analysis because of their high potential to construct different biosensors with high sensitivity, selectivity, and low cost. It is well-known that semiconductor materials with intrinsic large band gaps limit their applications in the range of ultraviolet (UV) irradiation. Moreover, UV light is somewhat too energetic and has a destructive effect on biomolecules. By introducing metal nanoparticles, carbon-based nanomaterials, and even organic molecules into semiconductor materials, the light response window for these functionalized nanocomposites can be extended to the visible light region. In this review, we mainly discuss PEC biosensors’ applications based on different state-of-the-art nanocomposites in three aspects, including the environmental field, food safety field, and medical field. The design principle and performance of PEC biosensors are systematically analysed. And we also briefly look forward to the development trend of this kind of PEC biosensors in the future.

Exceptional Radiation Absorption in a Pentagon-Based Si Allotrope.

Excellent photovoltaic performance is predicted in a pentagonal covalent network of Si in a hollow structure exhibiting both thermal and dynamical stability. Consisting of a combination of sp2 and sp3 hybridized Si atomic orbitals, the GW0 computed band structure shows an indirect band gap near the zone edge and also a manifold of directly absorbing transitions at frequencies in the window of visible light, in distinction with conventional Si. Hydrogenation of a single sp2 site is predicted to lead to a robust local magnetic moment. We find a low formation energy at low pressure that is compatible with other experimentally known phases, suggesting that a stable phase might be obtained.