Effect Of Illumination Research Articles

EFFECT OF LIGHTING LEVELS AND LAMP TYPES FOR CRIME PREVENTION IN THAI PEDESTRIAN WALKWAYS

The effects of illuminance level and lamp type were investigated for crime prevention in Thai pedestrian walkways aimed to examine the effects of illuminance on perceived safety, pedestrian behaviour, and criminal identification as part of crime prevention. Laboratory tests were carried out at the Faculty of Architecture, Kasetsart University. Five levels of illuminance: 10, 20, 50, 100, and 200 lux, and the types of lamps—HPS, LED Daylight and LED Warm White were investigated. Experimental tests were performed using a 3D model with DIALux simulation. Results showed that each lamp type required a different illuminance to optimize crime prevention. The HPS lamp with an illuminance of 200 lux was found to be the most suitable level for perceived safety, while 10 lux was suitable for pedestrian behaviour and 10 lux was suitable for criminal identification. For the LED Daylight lamp, the illuminance of 200 lux was the most appropriate level for perceived safety, while 20 lux was suitable for pedestrian behaviour and 10-20 lux was enough for criminal identification. For the LED Warm-white lamp, the illuminance of 10 lux was the most appropriate level for perceived safety, with 20 lux for pedestrian behaviour, and 10-20 lux for criminal identification.

Photophysical Ion Dynamics in Hybrid Perovskite MAPbX3 (X=Br, Cl) Single Crystals

AbstractHybrid organic–inorganic perovskites (HOIPs) are promising candidates for next‐generation photovoltaic materials. However, there is a debate regarding the impact of interactions between the organic center and the surrounding inorganic cage on the solar cell's high diffusion lengths. It remains unclear whether the diffusion mechanism is consistent across various halide perovskite families and how light illumination affects carrier lifetimes. The focus is on ion kinetics of (CH3NH3)PbX3 (X = Br, Cl) perovskite halide single crystals. Muon spectroscopy (μ+SR)is employed to investigate the fluctuations and diffusion of ions via the relaxation of muon spins in local nuclear field environments. Within a temperature range of 30–340 K, ion kinetics are studied with and without white‐light illumination. The results show a temperature shift of the tetragonal‐orthorhombic phase transition on the illuminated samples, as an effect of increased organic molecule fluctuations. This relation is supported by density functional theory (DFT) calculations along the reduction of the nuclear field distribution width between the phase transitions. The analysis shows that, depending on the halide ion, the motional narrowing from H and N nuclear moments represents the molecular fluctuations. The results demonstrate the importance of the halide ion and the effect of illumination on the compound's structural stability and electronic properties.

The effect of light on a bioprinted co-culture system of murine rat islets and photosynthetically active microalgae

The co-cultivation of mammalian cells with microalgae is an innovative concept to overcome one major limitation in tissue engineering and regenerative medicine: shortage of oxygen. Under illumination, photosynthetically active microalgae can produce oxygen, consequently increasing the potential construct dimension. In such co-cultures, mammalian cells are exposed to light, which does not reflect their natural conditions and can negatively influence their viability and functionality.In this study, 3D extrusion bioprinted pancreatic murine Islets of Langerhans should be co-cultivated with the bioprinted green microalgae species Scenedesmus sp. to improve the oxygen supply of the Islets in a potential insulin-producing implant. After defining the microalgae partner and a suitable co-culture medium that supported the functionality of both cell types, the focus was put on the effects of long-term red, blue and white light illumination on this system. First, the direct influence of light of different wavelengths on both microalgae and different mammalian cell types was investigated to find an ideal illumination regime, followed by an investigation into the influence of light on the culture medium. It was found that long-term exposure to blue or white light is detrimental to mammalian cells itself as well as the medium, while long-wave light has no effect on the function of mammalian cells.

The effect of yellow and red illuminations on the swimming behaviour, mortality and growth rates of yellowfin tuna juveniles (Thunnus albacares)

The effect of yellow and red illuminations on the swimming behaviour, mortality and growth rates of yellowfin tuna juveniles (<i>Thunnus albacares</i>)

Antifungal and antibacterial investigation of quinary Zr Al Fe Co Ni layered double hydroxide and its Al Fe Co Ni quaternary and Fe Co Ni tertiary roots.

Layered double hydroxides (LDH) are promising 2D nanomaterials being investigated for several engineering and biomedical applications. In this work, quinary Zr Al Fe Co Ni LDH and its Al Fe Co Ni LDH quaternary and Fe Co Ni LDH tertiary roots were prepared and characterized. All samples showed an aggregated, layered morphology with zero surface charge and approximately 300 nm of hydrodynamic size. BET surface area of Al Fe Co Ni LDH showed a remarkable value of 143.25 m2 g-1 as opposed to 26.2 m2 g-1 and 45.4 m2 g-1 for Fe Co Ni LDH and Zr Al Fe Co Ni LDH, respectively. The antimicrobial activity of the prepared samples was assessed against the many pathogenic bacteria; Bacillus (B.) subtilis, Escherichia (E.) coli, Haemophilus (H.) influenza, Listeria (L.) monocytogenes, Staphylococcus (S.) aureus, and Streptococcus (St.) pneumonia, and six fungal species. Furthermore, anti-biofilm activity, growth curve assay, and effect of UV illumination were examined against various pathogenic microbes. Zr Al Fe Co Ni displayed remarkable antibacterial activity, as indicated by the lowest values of the minimum inhibitory concentrations (MIC) of 4-166.7 μg mL-1. Results for fungal strains varied in terms of their susceptibilities for the different samples tested. Zn Al Fe Co Ni was able to inhibit the biofilm formation of S. aureus (96.09%), E. coli (98.32%), and Candida (C.) albicans (95.93%). This study shown that certain LDH categories, particularly Zr Al Fe Co Ni, may be promising antibacterial agents against variety of pathogenic microorganisms that cause serious infections.

Efficient Binocular Rendering of Volumetric Density Fields With Coupled Adaptive Cube-Map Ray Marching for Virtual Reality.

Creating visualizations of multiple volumetric density fields is demanding in virtual reality (VR) applications, which often include divergent volumetric density distributions mixed with geometric models and physics-based simulations. Real-time rendering of such complex environments poses significant challenges for rendering quality and performance. This article presents a novel scheme for efficient real-time rendering of varying translucent volumetric density fields with global illumination (GI) effects on high-resolution binocular VR displays. Our scheme proposes creative solutions to address three challenges involved in the target problem. First, to tackle the doubled heavy workloads of binocular ray marching, we explore the anti-aliasing principles and more advanced potentials of ray marching on interior cube-map faces, and propose a coupled ray-marching technique that converges to multi-resolution cube maps with interleaved adaptive sampling. Second, we devise a fully dynamic ambient GI approximation method that leverages spherical-harmonics (SH) transform information of the phase function to reduce the huge amount of ray sampling required for GI while ensuring fidelity. The method catalyzes spatial ray-marching reuse and adaptive temporal accumulation. Third, we deploy a two-phase ray-tracing algorithm with a tiled k-buffer to achieve fast processing of order-independent transparency (OIT) for multiple volume instances. Consequently, high-quality and high-performance real-time dynamic volume rendering can be achieved under constrained budgets controlled by developers. As our solution supports mixed mesh-volume rendering, the test results prove the practical usefulness of our approach for high-resolution binocular VR rendering on hybrid multi-volumetric and geometric environments.

Turing patterns on rotating spiral growing domains.

We investigate the emergence of Turing patterns in a system growing as a rotating spiral in two dimensions, utilizing the photosensitivity of the chlorine dioxide-iodine-malonic acid (CDIMA) reaction to control the growth process. We observe the formation of single and multiple (double and triple) stationary spiral patterns as well as transitional patterns. From numerical simulations of the Lengyel-Epstein model with an additional term to account for the effects of illumination on the reaction, we analyze the relationship between the final morphologies and the radial and angular growth velocities, identify conditions conducive to the formation of transitional structures, examine the importance of the size of the initial nucleation site in determining the spiral's multiplicity, and evaluate the stability and robustness of these Turing patterns. Our results indicate how inclusion of rotational degrees of freedom in the growth process may lead to the formation of a diverse new class of patterns in chemical and biological systems.

The application and challenges of virtual reality technology in creative advertising design

Abstract With the advancement of science and technology, virtual reality (VR) technology has been widely used in advertising. However, its practical application and challenges in creative advertisement must be studied deeply. The study aims to analyze the effects of VR technology on advertisement design and the technical difficulties it faces. The research methods include camera calibration of virtual advertisements, motion tracking, and calculation of lighting effects, etc. The results show that the use of VR technology of the results show that the virtual advertisement using VR technology can effectively improve the correct recall rate (by 12%) and the correct re-recognition rate (by 10.5%) of the advertisement brand. At the technical level, real-time motion tracking of billboards is achieved, and the average error is controlled within 0.6 pixels. The consistency of illumination of virtual advertisements can be effectively improved using the inverse illumination method. The conclusions show that virtual reality technology has great potential in the design of creative advertisements. Still, at the same time, it also faces the challenges of the accuracy of the camera calibration, the efficiency of the motion tracking algorithm, and simulation of the illumination effect.

On the Antenna Illumination Effects in Monostatic Reflectivity Determination for Microwave Calibration Targets

On the Antenna Illumination Effects in Monostatic Reflectivity Determination for Microwave Calibration Targets

A Novel Line-Scan Algorithm for Unsynchronised Dynamic Measurements

In non-destructive inspections today, the size of the sample being examined is often limited to fit within the field of view of the camera being used. When examining larger specimens, multiple image sequences need to be stitched together into one image. Due to uneven illumination, the combined image may have artificial defects. This manuscript provides a solution for performing line-scan measurements from a sample and combining the images to avoid these artificial defects. The proposed algorithm calculates the pixel shift, either through checkerboard detection or by field of view (FOV) calculation, for each image to create the stitched image. This working principle eliminates the need for synchronisation between the motion speed of the object and the frame rate of the camera. The algorithm is tested with several cameras that operate in different wavelengths (ultraviolet (UV), visible near infrared (Vis-NIR) and long-wave infrared (LWIR)), each with the corresponding light sources. Results show that the algorithm is able to achieve subpixel stitching accuracy. The side effects of heterogeneous illumination can be solved using the proposed method.

Simulation of the temperatures in the permanently shadowed region of the Moon's south pole and data validation

The permanently shadowed regions (PSRs) at the lunar poles without direct solar illumination maintain low temperatures throughout the year, making them optimal environments for the preservation of water ice. This paper investigates the diurnal and seasonal temperature variations of the PSRs within craters at the lunar south pole. The craters de Gerlache, Shoemaker, Amundsen, and Wiechert E are selected to explore how latitudes and shapes impact PSR temperature. Using the ray tracing approach, the shadow effect of terrain on the scattered sunlight and thermal radiation is calculated. PSR temperatures are simulated with the one-dimensional heat conduction equation. The thermal emissivity of the lunar surface is studied. Simulations with anisotropic emissivity are closer to the Diviner data in PSRs than the simulations with isotropic emissivity. In addition, by comparing the simulations to the Diviner data, it is found that the thermal conductivity at the extremely low temperatures in PSRs might be lower than that at high temperatures outside the PSRs. Simulations of the selected craters are used to study the influence of polar day phenomena occurring at high-latitude craters during the summer and the effect of direct solar illumination at the floors of low-latitude craters on the temperature distribution of PSRs. The influence of crater shape is analyzed as well by investigating the temperature distributions within PSRs of flat-floored and bowl-shaped craters. With the analysis of the heat flux propagation distances, emission angles, and incident angles, this study quantitatively elucidates the spatial and temporal variations in PSR temperatures. To explain why the Diviner data are lower than the simulation results at the solar-illuminated crater walls, an undulating rough surface is generated. The locations of the Sun and the observer on opposite sides of the rough surface may decrease the observed infrared brightness temperature according to the simulations. The PSR peak temperatures simulated with the anisotropic emissivity and thermal conductivity for PSRs are used to search for low-temperature areas suitable for preserving water ice within de Gerlache and Shoemaker.

An empirical study on the effect of outdoor illumination and exercise intervention on Children's vision.

To explore the relationship between outdoor lighting and sports and the development of myopia, and to analyze the effects of outdoor lighting and exercise on the diopter of children with normal vision and myopia, so as to provide guidance for the prevention and treatment of myopia in children and adolescents in the future. A total of 201 children were divided into two groups according to myopia or not. Each group was randomly divided into 4 groups: outdoor exercise group, outdoor control group, indoor exercise group and indoor control group. Among them, the outdoor exercise group and indoor exercise group received moderate and high intensity aerobic exercise 3 times a week for 60 min each time for 12 months, while the outdoor control group and indoor control group had normal study and life during the corresponding period of time. No additional exercise intervention. At the end of the experiment, the diopter of each group was compared. The diopter of all groups with normal vision and myopia decreased significantly after the experiment (p < 0.01). There were significant differences in diopter between outdoor exercise group and indoor control group (p < 0.01), between outdoor exercise group and indoor control group (p < 0.05), and between indoor exercise group and indoor control group (p < 0.01). There were significant differences in diopter between indoor exercise group and indoor control group (p < 0.01). The differences among myopic children after the experiment showed that there was significant difference in diopter between outdoor exercise group and indoor exercise group (p < 0.05), between outdoor exercise group and indoor control group (p < 0.01), and between outdoor control group and indoor control group (p < 0.05). There were significant differences in the changes of diopter between the outdoor control group and the indoor exercise group with normal vision and myopia before and after the experiment (p < 0.05). Outdoor light and exercise intervention can have a beneficial effect on children's vision, but because of whether children are myopic or not, the effect is different, outdoor light and exercise have a better effect on reducing the diopter of children with normal vision.

Effect of ultraviolet illumination on corrosion resistance of 304 austenitic stainless steel in molybdate-containing solution

This study investigates the effect of ultraviolet (UV) illumination on the corrosion resistance of 304 stainless steel in molybdate-containing solution. The UV illumination was found to reduce the passivation and pitting resistance of the passive films. In addition, the passive film exhibited n-type semiconductor characteristics. Under UV illumination, the content of Cr2O3 within the passive film decreased. Moreover, the formation of a built-in electric field inhibited the absorption of MoO42− on the substrate surface, thereby weakening the corrosion inhibition of Na2MoO4. This leads to a reduction in the corrosion resistance of the passive film.

Light-enhanced osmotic energy generation with an aramid nanofiber membrane

Osmotic energy generation with reverse electrodialysis through membranes provides a worldwide free energy resource. Photo-driven proton transport in photosynthesis supplies basal energy for plants and living organisms on the planet. Here, we utilized aramid nanofiber (ANF) semiconductor-based membranes to enable light-driven proton transport for osmotic energy generation. Under unilateral illumination, the light-driven proton transport system converted light energy into electrical energy and showed wavelength- and intensity-dependent transmembrane potentials and currents. Interestingly, the synergistic effects of simultaneous illumination and pressure provided a five-fold increase in the voltage and a three-fold increase in the current relative to pressure alone. Density functional theory calculations and spectroscopic measurements demonstrated that the ANF and photoinduced electrons enabled proton transport during illumination and generated a transmembrane potential and current. The light-driven proton transport system supports the development of devices with flexible and stable ANF membranes.

Coupled effects of solar illumination and phenology on vegetation index determination: an analysis over the Amazonian forests using the SuperDove satellite constellation

ABSTRACTDespite the importance of the Amazonian rainforests in the global carbon cycle, their phenological responses measured by large field-of-view satellite sensors are still not completely understood. In this scenario, close-to-nadir observations at high spatial and temporal resolutions made by satellite constellations may contribute to improve this knowledge. Here, we investigated the sensitivity of five vegetation indices (VIs) to canopy shadows over 15 protected forests of the Amazon, and the possible existence of coupled effects of solar illumination and vegetation phenology on the VI determination. The VIs are the Enhanced Vegetation Index (EVI), Green-Red Normalized Difference (GRND), Modified Photochemical Reflectance Index (MPRI), Normalized Difference Vegetation Index (NDVI), and RedEdge Normalized Difference (REND). They were calculated from 432 images obtained in 2022 by the Planet’s eight-band SuperDove instrument. Few daily images acquired on the same day with distinct Solar Zenith Angle (SZA) were used to disentangle the effects of solar illumination from those of vegetation phenology. The results showed the presence of coupled effects of solar illumination and vegetation phenology on the EVI determination regardless of the site location, especially over dense forests. Such effects were not observed significantly in the GRND, MPRI, NDVI, and REND data. When the vegetation phenology was kept fixed in the analysis, solar illumination generated pseudo-greening effects from the EVI, even for small differences in SZA between daily observations. As the most sensitive VI to illumination conditions, the EVI increased from the beginning to the end of the dry season tracking solar angles and shade fractions. This dry-season trend was not observed for GRND, MPRI, NDVI, and REND, which presented low correlations with SZA and shade fractions. These four VIs were correlated with each other over most sites, which explained the agreement observed between their seasonal profiles. From the analysis of 15 sites distributed throughout the Amazon, our findings did not confirm patterns of large-scale greening at the end of the dry season. Local changes in greening (vegetation productivity) and browning were captured by the VIs over a few sites but in different periods of the dry season (June to September). At the high spatial scale of SuperDove observations, our results highlight the necessity of correcting solar and, in some cases, terrain illumination effects on the EVI before retrieving phenological metrics over the Amazon.

Neural Global Illumination: Interactive Indirect Illumination Prediction under Dynamic Area Lights.

We propose neural global illumination, a novel method for fast rendering full global illumination in static scenes with dynamic viewpoint and area lighting. The key idea of our method is to utilize a deep rendering network to model the complex mapping from each shading point to global illumination. To efficiently learn the mapping, we propose a neural-network-friendly input representation including attributes of each shading point, viewpoint information, and a combinational lighting representation that enables high-quality fitting with a compact neural network. To synthesize high-frequency global illumination effects, we transform the low-dimension input to higher-dimension space by positional encoding and model the rendering network as a deep fully-connected network. Besides, we feed a screen-space neural buffer to our rendering network to share global information between objects in the screen-space to each shading point. We have demonstrated our neural global illumination method in rendering a wide variety of scenes exhibiting complex and all-frequency global illumination effects such as multiple-bounce glossy interreflection, color bleeding, and caustics.

Experimental study on the influence of illuminance and spectral wavelength on image and spectral parameters of coal and gangue

ABSTRACT To reveal the effects of illuminance and spectral band changes on coal and gangue image and spectral parameters, and to provide fundamental data for using multispectral images in coal and gangue recognition research, this paper analyzes image parameters (standard deviation, skewness, entropy, and contrast) and the spectral parameter using experimental methods, and compares the differences between coal and gangue parameter values. First, we analyze the variations of parameters, and find that as illuminance increases, the image parameters fluctuate in shorter spectral bands but change slightly in longer ones, while the spectral parameter increases across all bands; as wavelength increases, the image parameters rise or fluctuate within 546–622 nm, while the spectral parameter increases; in other bands, all parameters initially decrease before stabilizing. Second, we compare parameter deviation by normalizing coal and gangue values, and find that coal and gangue have the largest deviation in the spectral parameter, and the smallest in skewness; they have the largest fluctuation range in entropy, and the smallest in skewness; image parameters are more sensitive to changes in illuminance and spectral bands than the spectral parameter; and the deviations in both image and spectral parameters are larger at 7000lux and 585 nm than at other settings.

A study of spatial rationality in the architectural design of senior citizen apartments in terms of calculation and biological effects

Abstract This paper is based on the photobiological effect of the role of the collation of different light colors under the elderly pupil change and the luminance level function of the relationship between the equation so as to use this for the rationality of the design of the elderly housing. The non-visual direct response (nvRD) model is also used to predict the relative non-visual response to light and to compare the relative effectiveness of different light modes in providing potential health benefits to humans. The effects of different light illumination on mood affectivity and visual comfort were calculated using the modified spatial contrast (mSC) model and the preliminary gaze response light drive (GRL) model. Finally, the effects of different light intensities and situations on the physical heart rate and cardiovascular indexes of the elderly were examined using the experimental design of photobiological effects. The results showed that the T-wave time under green light increased by 4.008 ms on average, and the QT band interval under red light and green light had a more obvious increase, with an average increase of 5.131 ms for red light and 7.238 ms for green light, while the ventricular rate under blue light showed signs of acceleration, with an average increase of 2.352 beats. The rational design of space in elderly apartments is supported by theoretical reference and data basis in this paper.

The effects of illumination on the current conduction mechanisms of the Au/C20H12/n-Si Schottky barrier diode (SBD)

Using the I-V characteristics both in the dark and under varied illumination-intensities (50–250 mW.cm−2) by 50 mW.cm−2 steps in the wide range bias-voltage (±5 V), specific fundamental electrical and photo effects parameters of the Au/C20H12/n-Si SBD were examined. Due to the creation of electron–hole pairs and their drift in opposite directions under the influence of an electric field, the value of photocurrent in the reverse bias (Iph) increases when illumination density is increased. The barrier height (ΦB0) tended to decrease due to the increase in photocurrent, while the diode’s ideality factor (n) increased with increasing illumination intensity. Also, the Schottky structure’s open-circuit voltage (Voc), short circuit current (Isc), filling factor (FF), and efficiency (η) were determined to be 0.358 V, 95.5 μA, 33%, and 0.028% under 50 mW.cm−2, respectively. The Rs and Rsh values found using Ohm’s law are a vital function of illumination and voltage which decrease with increasing illumination intensity. Additionally, using the forward bias I-V data and accounting for the bias dependent of the effective barrier height (Φe) and ideality factor n(V) for different illumination intensities, the energy density distribution profile of surface states (Nss) was obtained. According to these results, the organic interlayer consisting of C20H12 is light-sensitive and suitable for optoelectronic devices such as photodetectors and photodiodes.

Photodegradation of Methyl violet using Ag modified TiO2 nanotubes by UV and UV/ H2O2

Titanium dioxide (TiO2) is a semiconductor material that is frequently utilized in photodegradation applications. Its application in photodegradation is constrained by its broad band gap of 3.2 eV and increased rate of photoelectron recombination. However, by doping TiO2 with metallic nanoparticles, the band gap can be modified and photodegradation can be improved. The present study explores the fabrication of Ag-modified TiO2 nanotube photocatalysts by electrochemical anodization followed by hydrothermal method. The structural, morphological, compositional, optical, and thermal properties of prepared photocatalysts were characterized by X-ray analysis, Field emission scanning electron microscopy, N2 adsorption desorption analysis, X-ray photoelectron spectroscopy, Energy dispersive X-ray spectroscopy, UV–Vis diffuse reflectance analysis and Thermogravimetric-differential thermal analysis. The prepared photocatalyst was utilized to investigate the degradation of methyl violet in the presence of UVA and UVC radiation. The effects of UVA and UVC illumination on the degradation process, the effect of Ag loading in the TiO2 nanotube arrays and the role of H2O2 in the degradation of pollutant were studied. The degradation efficiency of methyl violet in the presence of UVC light was three times that of UVA light. For pristine TiO2 photocatalyst, the maximum degradation of 70% was obtained under UVC illumination in 8 h. When H2O2 was added, complete degradation was observed within 3 h. Reusability studies have shown that photocatalysts are stable and can be used for the degradation of methyl violet.