Daylight Research Articles

EFFECT OF GREEN AND UVA SPECTRA, AND PRE-HARVEST TREATMENTS ON BIOMASS AND METABOLITE YIELDS OF INDOOR CULTIVATED STEVIA REBAUDIANA

Stevia rebaudiana is a high-value crop due to the strong commercial demand for its metabolites (steviol glycosides, SG) as an organic low-caloric sweetener with up to 300 times the sweetness of conventional sugar. Two experiments were conducted in this study. In the first experiment, treatments with varying green (GR1 & GR2), UVA (UV1 & UV2) and treatments that had both (UVGR1, UVGR2) were used. In the second experiment, separate set of plants were grown under base red-blue (RB) and natural sunlight before being transferred to GR2, UV2, UVGR2, and monochromatic light treatments of blue, green and UVA, for 3 and 10 days before harvest. RB and sunlight were used as the control for artificial and natural light respectively. Plants grown under the UVGR1 had the highest dry leaf biomass accumulation of 4.75 g plant-1 (P<.05), 458% and 660% higher than the RB (0.98 g plant-1) and natural sunlight (0.72 g plant-1) controls. UVA had the highest metabolite (Stevioside + Rebaudioside A) concentration of 27% (P<.05) compared to the RB and sunlight controls at 17.24% and 15% respectively. The 10 day pre-harvest treatment with blue supplemented light yielded a dry biomass of 1.87 g plant-1, a 190% increase compared to the RB control. However, the 3 day pre-harvest treatment had higher metabolite yields improvements compared to 10 day treatments with the highest yield obtained of 21.10% in 3-day pre-harvest irradiation that had supplemental UVA and blue light. UVGR1 was the most productive lighting strategy, resulting in the highest overall metabolite yield per plant.

One-step synthesis of iron and carbon-quantum-dot co-decorated graphitic carbon nitride photocatalysts for carbamazepine degradation

In this study, a one-step hydrothermal preparation strategy was employed to synthesize a graphitic carbon nitride (g-C3N4) composite photocatalyst co-decorated with Fe sites and carbon quantum dots (Fe–CQDs/g-C3N4). Through a series of characterisation techniques, the successful integration of Fe atoms and carbon quantum dots (CQDs) onto g-C3N4 was achieved. Moreover, the presence of Fe, specifically Fe–N bonds, enhanced the charge-carrier transfer. With carbamazepine (CBZ) as the model pollutant, Fe–CQDs/g-C3N4 increased the photocatalytic activity with efficient peroxymonosulfate (PMS) activation under solar light irradiation, achieving 100% CBZ degradation in 15min over a wide pH range (3–9). Doping of the catalyst with Fe and CQDs resulted in a narrowing of the catalyst bandgap (2.25eV) compared to that of g-C3N4 (2.79eV), confirming the promotion of photo-induced charge separation. The CBZ degradation pathways were elucidated by ultrahigh-performance liquid chromatography and high-definition mass spectrometry. The Fe–CQDs/g-C3N4 composite was found to possess substantial potential for the efficient degradation of pollutants.

Boosting of photocatalytic degradation of Malachite green dye on facile synthesized highly active Ca@TiO2@g-C3N4 photocatalyst: Photocatalytic mechanism and kinetics

The Ca@TiO2@g-C3N4 nanocomposite was synthesized using non-precious components via heat polymerization followed by an ultrasonic power technique. The nanocomposite was extensively characterized. The X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) investigations unequivocally demonstrated the successful synthesis of the Ca@TiO2@g-C3N4 nanostructures. By account of its small particle size of 6.1081 nm, narrow band gap energy of 2.82 eV, and visible light activity, it was able to photodegrade MG dye in an efficient manner, achieving a 99.9 % degradation rate. The photoluminescence measurement demonstrated efficient separation and transfer of charge carriers. The ternary photocatalyst’s activity can be attributed to the production of a S-scheme heterojunction at the interfaces of TiO2@g-C3N4, the generation of defects such as Ti3+ and Ovs through the surface interaction of Ca with TiO2, and the enlarged surface area of the photocatalyst. The ternary Ca@TiO2@g-C3N4 nanostructures demonstrated superior photodegradation of MG dye in comparison to pure g-C3N4 and binary TiO2@g-C3N4. A viable mechanism is also shown through active species trapping experiments using different scavengers, demonstrating that the photogenerated h+ and O2− are vital in the photodegradation reaction under visible light irradiation. Furthermore, the catalyst’s potential for industrial applications is enhanced by its utilization of inexpensive initial ingredients, straightforward synthesis process, and ability to harness solar light.

Preparation and characterization of functionally antibacterial multi-layer lignin core-shell structure material with adsorption and high efficiency of photocatalysis for Cr(Ⅵ)

Wastewater with chromium is a common heavy metal pollution in industrial pollution, affecting health of human seriously, while adsorption and photocatalysis are efficient for Cr(Ⅵ) removal. The multi-layer lignin core-shell structure materials were prepared with kraft lignin/polydopamine core-shell structure material, using non-covalent bonding to induce the in-situ induction of TiO2. The hydroxyl group of kraft lignin and the amino group of polydopamine provided abundant adsorption active sites with adsorption capacity being 299mg/g at pH of 2. The adsorption process conformed to the Freundlich isotherm model and the pseudo-second-order kinetic model. The removal rate of Cr(Ⅵ) reached more than 99.9% within 10min under simulated solar light with influence of adsorption and photocatalysis. The multi-layer lignin core-shell structure materials presented excellent antibacterial activity, with the inhibition rate against S.aureus and E.coli being 40% under dark conditions and 99% under simulated solar light because h+ or ·OH producing by TiO2. The antibacterial multi-layer lignin core-shell structure materials showed good universality in water pollution treatment.

Transformative nanobioplasmonic effects: Toxicological implications of plasmonic silver nanoparticles in aquatic biological models

Silver nanoparticles (AgNPs) present unique properties, such as the induced localized surface plasmon resonance (LSPR) provoked under illumination with a proper wavelength, allowing these nanomaterials to be applied in fields such as catalysis and biomedicine. The study of AgNPs is also highly relevant from the environmental pollution viewpoint due to their high production and application in commercial products. Consequently, AgNPs reach aquatic environments and can be plasmonically stimulated under natural light conditions. This study investigates the toxic effects promoted by AgNPs under plasmonic excitation on the survival and physiology of the crustacean Daphnia similis. Two AgNP shapes (spherical and triangular) with plasmon bands absorbing in different spectral regions in the visible range were studied. The organisms were exposed to different AgNP concentrations under five different light conditions. Survival and changes in enzymatic biomarkers of oxidative stress and lipid storage were evaluated. Under LSPR conditions, we observed increased lethality for both AgNP shapes. LSPR effects of AgNPs showed mortality 2.6 and 1.7 times higher than the treatment under dark conditions for spherical and triangular morphologies respectively. The enzymatic assays demonstrated that plasmonic treatments triggered physiological responses. Significantly decreased activities were observed exclusively under LSPR conditions for both AgNP shapes. Considering all treatments, spherical AgNPs showed lower LC50 values than triangular ones, indicating their higher toxic potential. Our results demonstrate that LSPR AgNPs can induce biological responses associated with oxidative stress and survival. Therefore, this study highlights the potential risks of environmental contamination by plasmonically active metallic nanomaterials. These materials can enhance their toxicity when light-excited, yet the results also indicate promising opportunities for light-based therapies.

Role of LED (Light Emitting Diode) Light Illumination on the Growth of Plants in Greenhouse Farming-Hydroponics: IOT Technology

This review paper of literature highlights role of Light Emitting Diode (LED) on the growth of plants under controlled conditions of greenhouse farming particularly hydroponics. “Internet of Things (IOT)” is a system of interconnected computing devices, sensors, objects, microcontrollers, and cloud servers that can transmit data across a network and control other devices remotely without human intervention. Light Emitting Diode (LED) is a more efficient, versatile, lasts longer, highly energy-efficient, directional, narrow light spectrum, low power consumption, and little heat production. Common LED colors include amber, red, green, and blue. Hydroponic grow lights are designed to mimic the natural light that plants need for photosynthesis. Plants can only use the spectrum of visible light to produce photosynthesis, and this narrow spectrum (400 to 700 nanometer) is recognized as the Photosynthetically Active Radiation (PAR). The development and growth of diverse plant species can be influenced differently by a variety of colored LED lights. LED illumination provides an efficient way to improve yield and modify plant properties. Therefore, LED systems plays an important role in controlling morphological, genetic, physiological, chemical properties, increasing the synthesis of a variety of beneficial secondary metabolites, and optobiological interactions of plants in greenhouse farming. In general, red and blue light is essential for maximizing the photosynthesis process due to their strong absorption by the plant chlorophyll molecules. LED illumination sources are increasingly being utilized to enhance the growth rate of vegetables and herbs cultivated in greenhouses worldwide. LED illumination spectrum manipulation could enable significant morphological adaptations, and identification of the wavelength ranges is required to increase the plant photosynthesis process.

Enhancing Multilayer Glass Transmittance through Particle Swarm Optimization: An Experimental Approach

Abstract. This study focuses on enhancing the solar transmittance of multilayer glass in buildings located in cold northern regions to improve natural lighting efficiency and maintain indoor warmth in harsh climates. The Particle Swarm Optimization (PSO) algorithm is utilized to optimize the glass layer thickness, and an optical model is constructed to calculate the light transmittance of the multilayer glass. Through simulations and experimental analysis, the impact of different glass thickness combinations on overall transmittance is investigated. The study examines the optical properties of gradient glass and calculates changes in light transmittance under varying thickness combinations using MATLAB software. The PSO algorithm is applied for global optimization to identify the glass thickness combination that maximizes light transmittance within the specific visible light range (400nm-800nm). The experimental results, including spectral energy distribution before and after sunlight transmission, validate the accuracy of the theoretical model. The findings demonstrate that the optimized glass thickness combination significantly improves solar transmittance, especially within the visible light band, contributing to more energy-efficient and comfortable building environments in cold regions. Additionally, the potential of the PSO algorithm in global search and local convergence is analyzed, suggesting future research directions to further enhance optimization through dynamic adjustments or combining with other algorithms.

Optimization of Heat Reflective Triple Glazing Thickness Using the Artificial Fish Swarm Algorithm

Abstract. The significance of this research lies in its potential to improve energy efficiency in buildings, particularly in regions prone to high temperatures. By optimizing the thermal performance of heat-reflective glass, buildings can achieve better temperature regulation, leading to reduced dependency on air conditioning systems and lower energy costs. This research specifically targets the optimization of glass thickness, a critical factor influencing the overall effectiveness of heat-reflective glazing. The focus is on minimizing the transmitted light intensity for sunlight within the wavelength range of 300 to 2000 nm, which is vertically incident on the glass. The optimized glass thickness aims to maximize the thermal reflective properties while ensuring adequate natural light within indoor spaces. This study employs the Artificial Fish Swarm Algorithm to explore the optimal thickness of heat-reflective triple glazing. The effectiveness of this optimization method is assessed by comparing its results with experimental findings obtained through a systematic traversal of glazing thicknesses. The results highlight the potential of the Artificial Fish Swarm Algorithm to significantly enhance the thermal performance of heat-reflective glass, offering a practical solution for energy-efficient building design in hot climates.

Re-wilding the Night: Understanding How Darkness Is Valued Through the Nighttime Light Ecology of Bonn Botanical Gardens

Rewilding the Night is an interdisciplinary research project that aims to reimagine the urban night by capturing and communicating the qualities and rhythms of both artificial and natural light at night. Through a collaborative and experimental approach, the project seeks to make the urban night legible by employing sensor technologies and data visualization techniques, thus fostering a deeper engagement with and appreciation for urban darkness. The project has three aims—first, to capture and analyse environmental light data in Bonn Botanical Gardens, Germany to create an accessible understanding of the variations in natural and artificial nighttime light. Second, to use this groundwork to inform subsequent workshops to capture public perceptions and values regarding darkness; and third, to develop lighting prototypes that respond to light data and the insights gained through the workshops. Central to the project is the re-evaluation of urban darkness by questioning and expanding the normative frameworks surrounding urban lighting. The project underscores the importance of interdisciplinary research and design in addressing complex urban challenges, offering a model for future research aimed at creating more livable, sustainable, and inclusive urban night environments for both humans and non-humans.

Biodegradable cobalt and tin doped chitosan nanocomposites from structure tailoring to solar-driven photocatalytic degradation of toxic organic dyes.

The primary concern is the large amounts of emitted organic dyes through wastewater from numerous sectors. One of the most hazardous dyes commonly used in the industrial sector is methyl violet. It has been known to cause skin, gastric, and respiratory disorders. Therefore, a novel photocatalyst based on cobalt‑tin sulfide (Co3Sn2S2) was prepared using the solvothermal process. The photocatalyst was supplemented with Chitosan to prepare the cobalt tin sulfide-chitosan composite (Co3Sn2S2/Chi) for the photocatalytic degradation of methyl violet dye. Based on EDX analysis, a definite ratio of tin, cobalt, and sulfide was found. The FTIR of Co3Sn2S2/Chi revealed the characteristic bands of chitosan and metal sulfide bonds. SEM results showed that the particle had an irregular shape. The composite's crystalline structure was identified by XRD analysis as being 56 nm in crystalline size. The photocatalyst had a narrow band gap of 1.02 eV. At ideal conditions, the developed photocatalyst demonstrated greater degradation efficiency of methyl violet dye under solar light irradiation. The photocatalyst successfully decomposed 95 % of the methyl violet dye (40 ppm) within 70 min, operating at a pH of 9.0. This remarkable degradation was achieved by employing 0.25 g of the photocatalyst. The photocatalyst is more appealing and can be reused for up to three successive cycles. The photocatalyst is well-suited for "pseudo-first-order kinetics" to decontaminate methyl violet dye. The novel photocatalyst showed the most robust ability to decolorize methyl violet when exposed to sunlight and was a viable substitute for dye detoxification of organic dyes from wastewater.

Rapid Degradation of Dye Effluents with A SnS Catalyst: A Sustainable Approach Using Natural Light Under Ambient Conditions.

Dye degradation presents a persistent challenge in addressing water pollution. While several methods, including adsorption, biodegradation, and advanced oxidation processes, have been extensively explored, photocatalysis remains one of the most effective techniques. Conventional photocatalytic dye degradation processes often rely on expensive light sources and are time-intensive. Herein, we synthesized a SnS catalyst by the solvated metal atom dispersion (SMAD) method, using Sn foil and sulfur powder. The catalyst exhibited remarkable performance, achieving complete degradation of methylene blue within 2 minutes under ambient room light, without the need for any external light source. Similar degradation efficiency was achieved for methyl orange. To evaluate the role of light for the degradation, control experiments were conducted in the dark using methylene blue as a model dye. Although the degradation rate was slightly reduced, the catalyst still facilitated dye degradation in the absence of light. Additionally, the catalytic performance was tested with four other dyes under natural light, all of which yielded promising results, demonstrating the versatility and effectiveness of the SnS catalyst in dye degradation. This work highlights the potential of the SnS catalyst for efficient and rapid dye degradation under both light and dark conditions, offering an energy-efficient solution for wastewater treatment.

Photocatalytic degradation of microcystins from a field-collected cyanobacterial assemblage by 3D printed TiO2 structures using artificial versus solar irradiation

Microcystins (MCs) from freshwater cyanobacteria cause adverse effects to humans and ecological receptors through multiple exposure routes requiring adaptable and diverse treatment technologies. Photocatalysis of MCs using TiO2 is a promising technology; however, TiO2 photocatalysts as unbound nanoparticles in suspension are impractical to deploy. 3D Printing (3DP) provides a means to immobilize TiO2, producing deployable photocatalyst structures with extensive geometric freedom. The objective of this proof-of-concept experiment was to incrementally increase the environmental complexity (e.g., broad-spectrum fluorescent lamps and outdoor solar; filtered cell lysate and algal assemblage as the source of MCs) while comparing photocatalysis rates of MCs by 3DP TiO2 structures using polylactic acid (PLA) as the binder. Degradation half-lives of MCs were shorter in TiO2 embedded in 3DP PLA relative to PLA-only controls with differences in half-lives ranging from 3.6 to 10h. The one exception was the outdoor solar and an algal assemblage, where significant differences could not be discerned due to the already rapid photolysis rates. Ultimately, photocatalysis rates (half-life = 1.9–11.6h) were comparable to those previously published for TiO2 3DP structures in a laboratory environment and TiO2 fixed-films (half-life = 2–13h) demonstrating feasibility of 3DP to immobilize TiO2 photocatalysts under a range of conditions. This is the first time that MC concentrations from a field-collected HAB were photocatalytically degraded in both solar simulated light and sunlight using a custom-made advanced photocatalytic nano-composite with enhanced performance through high surface area design enabled by 3D printing. These data inform future development of scalable, retrievable, and operationally flexible structures with immobilized TiO2.

Cucumber Leaf Segmentation Based on Bilayer Convolutional Network

When monitoring crop growth using top-down images of the plant canopies, leaves in agricultural fields appear very dense and significantly overlap each other. Moreover, the image can be affected by external conditions such as background environment and light intensity, impacting the effectiveness of image segmentation. To address the challenge of segmenting dense and overlapping plant leaves under natural lighting conditions, this study employed a Bilayer Convolutional Network (BCNet) method for accurate leaf segmentation across various lighting environments. The major contributions of this study are as follows: (1) Utilized Fully Convolutional Object Detection (FCOS) for plant leaf detection, incorporating ResNet-50 with the Convolutional Block Attention Module (CBAM) and Feature Pyramid Network (FPN) to enhance Region of Interest (RoI) feature extraction from canopy top-view images. (2) Extracted the sub-region of the RoI based on the position of the detection box, using this region as input for the BCNet, ensuring precise segmentation. (3) Utilized instance segmentation of canopy top-view images using BCNet, improving segmentation accuracy. (4) Applied the Varifocal Loss Function to improve the classification loss function in FCOS, leading to better performance metrics. The experimental results on cucumber canopy top-view images captured in glass greenhouse and plastic greenhouse environments show that our method is highly effective. For cucumber leaves at different growth stages and under various lighting conditions, the Precision, Recall and Average Precision (AP) metrics for object recognition are 97%, 94% and 96.57%, respectively. For instance segmentation, the Precision, Recall and Average Precision (AP) metrics are 87%, 83% and 84.71%, respectively. Our algorithm outperforms commonly used deep learning algorithms such as Faster R-CNN, Mask R-CNN, YOLOv4 and PANet, showcasing its superior capability in complex agricultural settings. The results of this study demonstrate the potential of our method for accurate recognition and segmentation of highly overlapping leaves in diverse agricultural environments, significantly contributing to the application of deep learning algorithms in smart agriculture.

Improved photocatalytic decomposition of carbaryl pesticide in wastewater using ZnO nanorods

This study explores the enhanced photocatalytic performance of ZnO nanorods (ZnO-R) for degrading the carbaryl pesticide (CB) in wastewater. For comparison, commercial ZnO (ZnO-C) was used to evaluate the differences in the photocatalytic decomposition of CB between ZnO-R and ZnO-C. The results regarding the material properties demonstrated that ZnO-R enhances CB removal performance due to its unique rod shape, which extends light absorption and improves electron-hole separation. The removal rates of the carbaryl pesticide from the aqueous solution using ZnO-R and ZnO-C were 98.2% and 87.3%, respectively. Besides, the presence of other pesticides had a more negative impact on the performance of CB than inorganic contaminants. The degradation rates of CB using ZnO-R in wastewater were 99.8%, 68.2%, and 21.7% under UV, solar, and visible light, respectively. In addition, the degradation mechanism of CB using ZnO-R under UV light was proposed based on the n-type photocatalysis process. This work provides a method for selecting a suitable type of ZnO photocatalyst to control pesticide residue pollutants that are commonly found in agricultural activities.

The neurobiological mechanisms of photoperiod impact on brain functions: a comprehensive review.

Variations in day length, or photoperiodism, whether natural or artificial light, significantly impact biological, physiological, and behavioral processes within the brain. Both natural and artificial light sources are environmental factors that significantly influence brain functions and mental well-being. Photoperiodism is a phenomenon, occurring either over a 24 h cycle or seasonally and denotes all biological responses of humans and animals to these fluctuations in day and night length. Conversely, artificial light occurrence refers to the presence of light during nighttime hours and/or its absence during the daytime (unnaturally long and short days, respectively). Light at night, which is a form of light pollution, is prevalent in many societies, especially common in certain emergency occupations. Moreover, individuals with certain mental disorders, such as depression, often exhibit a preference for darkness over daytime light. Nevertheless, disturbances in light patterns can have negative consequences, impacting brain performance through similar mechanisms albeit with varying degrees of severity. Furthermore, changes in day length lead to alterations in the activity of receptors, proteins, ion channels, and molecular signaling pathways, all of which can impact brain health. This review aims to summarize the mechanisms by which day length influences brain functions through neural circuits, hormonal systems, neurochemical processes, cellular activity, and even molecular signaling pathways.

Evaluation study of solar powered public street lighting as battery charging at Islamic Center based on PSIM

Electrical energy is essential for the growth and advancement of technological knowledge that continues to increase. Solar cells are devices that convert solar energy through photovoltaic devices. Solar cell public street lighting (PJUBS) uses unlimited and free solar energy, is a feasible and cheap alternative to providing electric lighting. The Islamic center mosque is one of the places of worship for the majority of Muslims in the city of Lhokseumawe using public street lighting to support public security and safety. Installation of lamps for lighting is installed at several points, namely right, left or in the middle of the road, as needed, including flyovers, underpasses, and bridges. Public street lighting that is efficient and environmentally friendly is in accordance with SNI 7391: 2008. In this study, the lamps used in this evaluation study are solar types with a power of 50 Watts. The calculation results show that the illumination produced at the end of the road when using a 50 Watt solar LED lamp is 0.29 lux so that this does not comply with the provisions of BSN SNI 7391: 2008. This condition is influenced by several factors, namely surface temperature, shadows, inclination angle, light intensity, irradiation, and the condition of the panel surface in order to maximize the conversion value of sunlight into electrical energy

Glow-in-the-dark: Exploring the opportunities and challenges of bioluminescent plankton as a natural light source

Glow-in-the-dark: Exploring the opportunities and challenges of bioluminescent plankton as a natural light source

Adoption of a solar home lighting system: A behavioral paradigm shift from consumers to prosumers in the urban household energy transition of Punjab, India

Adoption of a solar home lighting system: A behavioral paradigm shift from consumers to prosumers in the urban household energy transition of Punjab, India

Evaluating Insect Abundance and Diversity in Organic Farming using Solar and LED Light Traps for Sustainable Pest Management

Evaluating Insect Abundance and Diversity in Organic Farming using Solar and LED Light Traps for Sustainable Pest Management

Photodegradation of Neonicotinoid Insecticides Nitenpyram, Thiacloprid, and Acetamiprid in Water and Soil Environments.

The photodegradations of three selected neonicotinoid insecticides nitenpyram, thiacloprid, and acetamiprid were investigated in both water and soil samples under natural sunlight, UVA light, and UVB light. The results indicate that these insecticides undergo significant degradations when subjected to sunlight, whether they are in deionized (DI) water, tap water, and DI water containing 100mg/L humic acids or in soil. The degradation half-lives of nitenpyram, thiacloprid, and acetamiprid in tap water under sunlight were found to be 3.7, 4.7, and 8.9h, respectively, in DI water 5.4, 6.3, 9.1h, respectively, in DI water containing 100mg/L humic acids 3.6, 3.3, 6.5h, respectively, and in soil 7.5, 7.9, and 15.9h, respectively. The degradation due to hydrolysis was found insignificant as compared to photodegradation. The examination of the effects of light source revealed that the UVB in the sunlight plays a major role in the photodegradation of these three neonicotinoids, and the effects of UVA and visible light are negligible. The analysis on the degradation products indicated that the nitroguanidine group in these insecticides is unstable and prone to break up under sunlight. A total of nine degradation products were detected, of which the health effects and the fate and transport in the environment need to be further studied.