Green Layer Research Articles

A set of embedding rules in IWT for watermark embedding in image watermarking

The development of new technologies has made image watermarking crucial in the digital era to preserve and protect illegal distribution of images against unauthorized users. This paper presents a robust image watermarking technique that employs a set of embedding rules in the three-level of integer wavelet transform (IWT). The proposed method aims to achieve high robustness of image watermarking while maintaining the imperceptibility. The proposed scheme divides the red and green layers into non-overlapping 16×16 blocks. Three levels of IWT are applied to obtain 2×2 LL sub-band, four coefficients of IWT are then modified based on the proposed set of rules for embedding watermark. The experimental results demonstrate a comparison of the proposed embedding and the existing methods. The proposed scheme produced an average NC value of 0.965 against the median filter. The results also showed the imperceptibility of the the image with a PSNR of 45.1760 db and SSIM of 0.9995.

Separation layers and their influence on green roof water storage

ABSTRACT This study deals with how adding separation layers to flat roofs improves their design, construction, and sustainability. Better understanding and use of these layers leads to increased durability, lower maintenance, and simpler execution, with potential for material reuse and performance enhancement. Currently, the optional nature of separation layers hinders the overall sustainability of roofing systems, so this research seeks to guide building professionals in selecting suitable separation layers for flat roofs, considering factors like location, function, material composition, and mass. Particularly, it examines the impact of Water Storage layers on self-sustaining green roofs, aiming to enhance thermal performance, especially when water is scarce. Results indicate that installing these layers significantly increases water retention below the drainage layer, primarily in extensive green roofs, where values rise by 17%. Water Storage layers also extend water availability after rainfall, raising maximum daily humidity levels inside the roof by up to 10% on the third day post-rainfall compared to green roofs without such a layer. Highlights The optional character related to separation layers lends a voluntary aspect to sustainability. Proper selection of separation layers’ characteristics ensures optimal roof functionality. The Water Storage separation layer increases humidity on the green roof's inner layers. The Water Storage separation layer extends the time for water usage on green roofs.

Ethanol-responsive structural colors with multi-level information encryption based on the patterned three-layer inverse opal photonic crystal

Stimulus-responsive inverse opal photonic crystals (IOPCs) with tunable structural colors show significant promise in information security. To improve upon the traditional bilayer structure with limited color information and single decoding mode, this work developed an ethanol-responsive structure with multi-level information encryption ability by inserting a functional layer into two shielding layers (red Layer A with a photonic stop band (PSB) at 640 nm and green Layer C with a PSB at 530 nm). The functional layer was composed of colorless Layer B, a quick response (QR) code pattern made of TiO2 nanoparticles, and a dense polymer. Due to the isolation of distinct layers, different reflectance values, and different PSB positions of the three-layer IOPC, the structural color of Layer B could only be “turned on” by wetting the entire structure when its PSB redshifted from 360 nm to 460 nm. Specifically, when either side was individually wetted, the PSB of Layer A or C redshifted to 825 nm or 685 nm, and the color of the QR code was dominated by the unwetted red or green layer. After the entire structure had been soaked, the blue QR code was decoded. Meanwhile, when the detecting angle increased from 5° to 60°, the PSBs of Layers B and C in the wetted three-layer IOPC blueshifted from 460 nm to 365 nm and from 685 nm to 540 nm, respectively, which resulted in a cascade decoding process with a single- or mixed-color output. This structure provides a good foundation for multi-level information encryption.

Ultraviolet color image sensor based on CsPbBr3 inorganic perovskite nanocrystal film.

Ultraviolet and color imaging require different image sensors and optical channels, which results in large size, complex structure, and high cost of imaging systems. Here, we report a novel, to the best of our knowledge, image sensor that combines ultraviolet and color imaging functions. The fabrication of this image sensor is achieved by coating high-transparency CsPbBr3 perovskite nanocrystals in a polymer film on the color filter layer of a silicon-based detector. The film, serving as an ultraviolet photoluminescent layer, exhibits high transparency, exceeding 91.5% at wavelengths beyond the photoluminescence peak of 513 nm. During ultraviolet imaging, the film converts ultraviolet light into visible light, which passes through the green filter layer to reach the detector for imaging. During visible light imaging, red light, green light, and most of the blue light pass through the CsPbBr3 perovskite nanocrystal film and color filter layer to reach the detector for imaging. As a result, the image sensor can capture both 257 nm solar-blind ultraviolet images and color photos in the visible light.

Do blue-green roofs yield optimal thermal performance? Synergy analysis of the combination of green roofs and water retention layer

Blue-green roofs can potentially enhance the outdoor thermal environment in urban areas and reduce indoor energy consumption. By integrating a water retention layer with green roofs, blue-green roofs maximize environmental benefits through rainwater storage and increased evapotranspiration. This study evaluates the thermal performance of blue-green roofs during summer and examines their potential for microclimate improvement and energy savings. The study investigates the individual and interactive effects of the blue-green roof components by measuring the upper and lower surface temperatures with incremental application of soil, blue, and green layers and analyzing their synergistic benefits. The results indicate that blue-green roofs exhibited a cooling effect of up to 7.5 °C on the upper surface temperature and up to 17.4 °C on the lower surface temperature, showing the greatest potential for improving indoor and outdoor thermal comfort. The synergistic effect of the blue-green roof was −0.80 °C on the upper surface and +1.59 °C on the lower surface. This research provides an in-depth investigation into the thermal performance of blue-green roofs in both indoor and outdoor spaces, highlighting their synergistic effects through incremental application. This contributes to climate-responsive architectural design and practices aimed at enhancing energy efficiency in building retrofitting for hot climates.

Empowering smart toys and devices with stretchable and vivid triboelectric layers for enhanced interaction and monitoring

The evolving landscape of intelligent devices and toys demands seamless interaction, exceptional performance, and visually captivating features. Triboelectric nanogenerators (TENGs) offer an eco-friendly solution for generating electrical energy in smart toys and devices. This research introduces high-power and stretchable triboelectric layers in various colors tailored for toys and wearable gadgets. Combination of the silicone rubber with the ceramic powders, not only improved mechanical properties, but also provided vibrant colors. This process enhanced the fracture strain and the toughness, and reduced the Young's modulus, so stretchability and overall quality were increased. The best composite, the green layer, demonstrated outstanding attributes such as a power density of 6.5 W/m2, a fracture strain of 385 %, a toughness of 1.86 Mj/m3, and a Young's modulus of 0.20 MPa. The green TENG, a sandwich format with an EGaIn electrode, was used for effective monitoring of human body movements. Additionally, a highly efficient machine learning model has been developed for identifying human motions with a remarkable accuracy of 98 %. The study highlighted the considerable power density, voltage, and current exhibited by the colorful TENGs. By integrating these TENGs into circuitry, an engaging toy was created that produces musical notes and displays corresponding pattern on a computer screen when a colorful array was pressed. These colorful nanogenerators hold significant promise for battery-free toys and wearable electronics.

Pea-like inspired design: Lignin nanospheres-mediated PVA film with high strength, low water evaporation permeability, strong UV resistance and anti-oxidation properties for extending food freshness

The excessive utilization of petroleum-based plastic products has inflicted significant harm upon the ecological and health problems, compelling individuals to continually seek renewable and biodegradable polymer materials as alternatives. Drawing inspiration from the structure of a natural pea pod, a unique interlocking packaging material based on a pea-like structure is obtained via green electrospinning and mild glutaraldehyde (GA) cross-linking method. Herein, polyvinyl alcohol (PVA) serves as a green protective layer encompassing the active lignin nanospheres (LNP) pod, forming a packaging film that prevents LNP migration. The LNP within the fibers can effectively shorten the fiber spacing, and when exposed to the GA vapor, they promote the bonding between neighboring fibers to form a tight interlock structure. Benefiting from the interlocking pea-like structure, the film exhibits excellent tensile strength (3.53 ± 0.02 MPa), wetting strength (1.92 ± 0.05 MPa), and outstanding water vapor barrier properties (3.27 ± 0.3 10−10 gm−1 s−1 Pa−1). Furthermore, the inclusion of LNP endows exceptional water resistance, UV-blocking capabilities, antibacterial and antioxidant properties, which can effectively prolong the storage life of perishable fruits. This eco-logical sustainable design holds tremendous potential in mitigating the burden on the environment, thus making a novel avenue for exploring alternatives to petroleum-derived plastics.

12‐4: Inorganic Halide Perovskite Thin Films Realized by Pulsed Laser Deposition over Large Area for MicroLEDs Color Conversion Layers

This paper reports the deposition of inorganic halide perovskite thin films, using pulsed laser deposition, as a way to fabricate green and red color conversion layers for microLEDs. The photoluminescence of the thin film reveal pure colors and uniform emission on 200 mm wafers. The unencapsulated thin films are stable under ambient air.

Quality of Harvested Rainwater from a Green and a Bitumen Roof in an Air Polluted Region

A one-year study was conducted to evaluate the impact of air pollution and roof coating on runoff quality. An existing 440 sq meter bitumen roof of a single-story building was coated with an extensive green roof layer on one half. Rainfall and runoff samples from both roofs were collected during 11 rainfall events after the separation of the first flush. The study monitored several key parameters, including pH, electrical conductivity (EC), turbidity, chemical oxygen demand (COD), ammonium nitrogen, nitrate nitrogen, and phosphates. The study revealed that both types of roofs altered the rainfall quality, but the changes caused by the green roof were more substantial. Although the retention of runoff from green roofs has a widely acknowledged positive impact on collecting systems, our study shows that green roofs also result in a 7.5-fold increase in COD concentrations, a 5.4-fold increase in the sum of ammonium and nitrate nitrogen, and a 2.3-fold increase in phosphates compared to bitumen roofs. A clear link between the quality of rainwater/runoff and air pollution was not established. The study's findings will aid in the development and management of local rainwater harvesting systems and enhance global understanding of the primary quality parameters of various roof types, particularly in regions with air pollution. Doi: 10.28991/CEJ-2024-010-05-015 Full Text: PDF

Gradient Variation and Correlation Analysis of Physical and Mechanical Properties of Moso Bamboo (Phyllostachys edulis).

This study aimed to investigate the gradient properties of bamboo at the microscopic level and provide a basis for improving the utilization rate of bamboo. Using moso bamboo (Phyllostachys edulis (Carrière) J. Houz.) as a research subject, the variation of vascular bundle area percentage, chemical content, relative crystallinity (CR), mechanical properties of different bamboo slivers, and correlation between those parameters were analyzed. From the bamboo green layer (BGL) to the bamboo yellow layer (BYL), the distribution of vascular bundles changed from dense to sparse. Cellulose and lignin mass content decreased gently, and hemicellulose mass content showed gradual increases. The CR showed an order of bamboo middle layer (BML) > BGL > BYL. The tensile modulus of elasticity, tensile strength, bending modulus of elasticity, and bending strength decreased from BGL to BYL. The order of influence degree on mechanical properties of moso bamboo was vascular bundle area, hemicellulose content, lignin mass content, density, and CR, and these factors correlated with mechanical properties at a significant level (p < 0.05). Vascular bundle area had a decisive effect on the mechanical properties of bamboo. The vascular bundle area and density were linearly correlated with mechanical properties, while the lignin mass content and CR were curve-linearly correlated with mechanical properties.

Green Roofs on Shipping Containers: How Substrate Thickness Affects Thermal Performance

Green roofs have become a popular sustainable solution in urban areas, and in recent years, shipping containers have gained popularity as a sustainable alternative for housing. A promising proposal is to combine these two solutions. This research aims to analyze the thermal behavior of experimental modules of scale constructions. Four modules were constructed with different substrate thicknesses (4, 6, 8, and 12 cm) to verify the impact on thermal behavior and provide guidance for this technology. Additionally, another module was built without a green roof for control purposes. The indoor and outdoor air temperatures and humidities, soil moistures, and temperatures between green roof layers were recorded in a tropical climate in summer. The behavior was similar between the different thicknesses for the whole period but with significant differences in the indoor temperature amplitudes (13.8 °C for the thinner substrate, 9.7 °C for the thicker one, and 38.7 °C for the bare roof). This study also revealed considerable heat conduction between the side walls and the slab, which resulted in an upward heat flow to the substrate during a day with a clear sky, which is the opposite of what is observed in conventional roofs. During the night and rainy periods, temperatures tend to become closer between the roof’s layers when the substrate dissipates the energy absorbed throughout the day.

Analytical Study of Polychrome Clay Sculptures in the Five-Dragon Taoist Palace of Wudang, China

During the Ming Dynasty, the Five-Dragon Palace functioned as a royal Taoist temple set atop one of China’s holiest Taoist mountains, Wudang Mountain. Two tower polychrome sculptures with exquisite craftsmanship have remained over the centuries. In this study, the painting materials and the techniques used to construct these sculptures were analyzed through multiple characterization methods, including optical microscope (OM) observations, micro-Raman spectroscopy, scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM−EDS), X-ray diffraction (XRD), micro-Fourier-transform infrared spectroscopy (μ−FTIR), and pyrolysis–gas chromatography/mass spectrometry (Py−GC/MS). The results revealed that the pigments used in these sculptures included red pigments, which were composed of mercury (II) sulfide (cinnabar or vermillion), minium (Pb3O4), and hematite (Fe2O3); green pigments, which included atacamite and botallackite (Cu2Cl(OH)3), and blue pigments, which comprised smalt (CoO·nSiO2) and azurite (Cu3(CO3)2(OH)2). The white base layer was composed of quartz and mica minerals combined with gypsum or plant fiber, and the gold foil was adhered to the surface using heated tung oil. In addition, a special multi−layer technique was applied, with red under the golden gilding, white under the blue layer, and gray and black under the green layer. Drying oil was used as a binder for lead-containing pigments. This study offers substantial proof of reliable techniques to use in the continuing conservation of these sculptures, and it also serves as a foundation to determine if they can be dated to the late Ming or early Qing Dynasty (17th century).

Behaviour of Spread Footings Resting on Fibre-Reinforced Green Binder-Stabilised Sand Layers

Behaviour of Spread Footings Resting on Fibre-Reinforced Green Binder-Stabilised Sand Layers

Geomicrobiological characterization of the evaporitic ecosystem in the hypersaline lake Laguna Verde (Andean Puna, Northwestern Argentina).

Laguna Verde's dome-shaped structures are distinctive formations within the Central Andes, displaying unique geomicrobiological features. This study represents a pioneering investigation into these structures, assessing their formation, associated taxa, and ecological significance. Through a multifaceted approach that includes chemical analysis of the water body, multiscale characterization of the domes, and analysis of the associated microorganisms, we reveal the complex interplay between geology and biology in this extreme environment. The lake's alkaline waters that are rich in dissolved cations and anions such as chloride, sodium sulfate, and potassium, coupled with its location at the margin of the Antofalla salt flat, fed by alluvial fans and hydrothermal input, provide favorable conditions for mineral precipitation and support for the microorganism's activity. Laguna Verde's dome-shaped structures are mainly composed of gypsum and halite, displaying an internal heterogeneous mesostructure consisting of three zones: microcrystalline, organic (orange and green layers), and crystalline. The green layer of the organic zone is predominantly composed of Proteobacteria, Bacteroidetes, and Cyanobacteria, while the orange layer is mostly inhabited by Cyanobacteria. The results of the study suggest that oxygenic photosynthesis performed by Cyanobacteria is the main carbon fixation pathway in the microbial community, supported by carbon isotopic ratios of specific biomarkers. This finding highlights the important role played by Cyanobacteria in this ecosystem.

Process and Performance Optimization of Green Quantum Dot Color Conversion Layer Based on Inkjet Printing

Process and Performance Optimization of Green Quantum Dot Color Conversion Layer Based on Inkjet Printing

ОБОСНОВАНИЕ ПРОДОЛЖИТЕЛЬНОСТИ СУШКИ ЛЮЦЕРНЫ С ИСПОЛЬЗОВАНИЕМ СОЛНЕЧНОЙ ЭНЕРГИИ И РЕЗУЛЬТАТЫ ПРОИЗВОДСТВЕННЫХ ИСПЫТАНИЙ ГЕЛИОСУШИЛКИ

One of the herbs drying process’s conscious control’s main prerequisites is its duration’s ability calculating. Currently, the drying process’s approximate methods based on the various dependencies’ approximation calculating are widely developed. To determine the total drying time, there are several simple empirical methods, the most common of which is the drying coefficient, that its duration graphically determining. To justify the drying speed and duration, it is necessary the drying coefficient dependence on the parameters finding that drying process’s course determining. Such parameters at alfalfa drying are coolant’s temperature, velocity and humidity, as well as the green mass layer’s height, its granulometric state and initial humidity. By experimental data processing according to multiple regression analysis program, a general formula for the drying coefficient’s dependence on the main process parameters was obtained. The overall correlation coefficient of the results of processing experimental data on the drying coefficient was 0,93. Due to the use of the values of the drying coefficients of herbs, a formula was obtained by a number of mathematical transformations to determine the duration of drying alfalfa at various parameters. The alfalfa drying’s total time at rational operating parameters, according to this calculating formula, will be 0,75 hours. To verify the theoretical and laboratory studies’ results, an experimental test of a drying herbs by installation’s pilot industrial sample by solar energy using with a capacity of 100 kg/h was conducted. As drying result, hay with 21,4% of moisture with 208 mg/kg of carotene was obtained, as well as grass cutting with 14% of moisture with of 224,3 mg/kg of carotene and 0,1 m of grinding degree and 12% of moisture with 249,2 mg/kg of carotene at 0,03 m of size crushing.

РЕЗУЛЬТАТЫ ЭКСПЕРИМЕНТАЛЬНЫХ ИССЛЕДОВАНИЙ ГЕЛИОСУШИЛКИ

To study the herbs drying process by solar energy using, a series of experiments on alfalfa in the third year of development were conducted. The site selection’s all requirements for crops’ placement and plots’ division with field experience methodology are consistence. To determine the drying regime’s effect on the alfalfa drying process kinetics, a series of experiments to effect of coolant humidity, its speed and temperature on the drying process studying were conducted. The experimental data analysis showed that the coolant’s temperature has the greatest influence on the herbs drying rate. At heliuoplant’s experimental studies’ course for drying herbs, influence degree of various indicators on the drying regime, alfalfa layer height, its grinding degree and the green mass’s initial moisture content on the drying process duration and alfalfa quality was determined. The drying duration, in depending on one factor at constant remaining of the other parameters was studied. Based on the analyses’ results, graphs of changes in the alfalfa’s carotene content in depending on the drying mode, green mass layer height and its granulometric state were constructed. It can be seen that at the coolant temperature decreasing, alfalfa quality is sharply decreased, that is not observed when the drying mode’s other parameters are changing, i. e. at the coolant change’s humidity and velocity, the carotene content is changed slightly. The best from the high quality feed’s obtaining point of view is drying alfalfa, crushed to a size of 0,03 m at a coolant temperature of 80 ...90°C. As a result of experimental data’s mathematical processing, a formula of the herbs drying coefficient’s dependence on the process’s main parameters was obtained. A comparison of the experimental data and the data calculated using the formula showed that the discrepancy does not exceed 17%. A comparison of the theoretical calculations and experimental studies’ results using possibility at theoretical developments in the new drying plants design has shown.

Experimental and numerical investigations on the thermal and moisture transfer in green dual layer wall for building

This study presents a numerical and experimental investigations of coupled temperature and humidity transfer through bio-sourced dual layer for building. Two types of materials are used as a low-density insulating material and a high-density structural material characterized by its mechanical structural behavior. The hygrothermal properties were measured and introduced in the developed dynamic model based on the Kunzel and Mendes models. The finite difference method was applied to solve the coupled heat and moisture transfer for one and dual layer building walls. Comparison of the Kunzel and Mendes models suggest that experimental tests offer accurate solutions. The study further explores a numerical transient simulation of hygrothermal response in real scenarios of a multi-layer building wall exposed to winter and summer climatic conditions. Building energy efficiency was investigated for the case where the biosourced insulating material was in the external or in the internal side of the building wall.

Axial Compressive Behavior of Slender Circular Columns Made of Green Concrete and Double Layers of Steel and GFRP Reinforcement

Axial Compressive Behavior of Slender Circular Columns Made of Green Concrete and Double Layers of Steel and GFRP Reinforcement

Green roof evaluation and comparison during summer in Central Europe climate

Greening structures, such as roofs or facades, attract the worldwide attention because of their multi-disciplinary benefits. Green roofs are considered to be one of the best ways to eliminate summer overheating, mitigate the climate change or reduce the urban heat island effect. Since 2020, experimental fragments of different green roofs are evaluated on the roof of one building in the university campus. Temperatures are measured within the roof and also in the additional green layers. Also the water retention is measured. In this paper, results of temperature measurements of three different types of protective layer on the single ply flat roof are presented. One is bare, unprotected PVC membrane, the other one is gravel and the third one is an extensive green roof. During the summer season and sunny days the daily amplitudes are reduced from approximately 56°C for the unprotected PVC membrane and 35 °C for the gravel to the 16 °C for the green roof. The gravel slightly reduced the maximum temperatures, but it has an accumulation capacity, which decelerates cooling of the surface and the heat emitted back to surroundings is higher. Water retention is also another benefit, which increases the reduction, but in this analysis the worst scenario with lack of any rainfall for more days was taken into account.