Search Results (229)

Semitransparent plastic films containing red-fluorescent pigments can increase the growth of some greenhouse crops despite a lower transmitted photosynthetic photon flux density (PPFD), but the underlying mechanism by which this occurs is not fully understood. We postulated it can be attributed to a lower blue-light environment that increases leaf expansion and thus photon capture. We examined the growth response and photosynthetic capacity of vegetable and ornamental greenhouse crops under a red-fluorescent plastic, plastics with varying transmission percentages of blue light (from 6% to 20%), and an uncovered greenhouse control with a 40% greater PPFD. When the transmitted PPFD was similar, decreasing the percentage of blue light increased the extension growth for some but not all species tested. Transmitted PPFD had a more pronounced effect on extension growth than the percentage of blue light. Lettuce shoot dry mass was greater under the red-fluorescent film than the other covered treatments and similar to the uncovered control with 40% more light. Regardless of the transmission spectrum, decreasing the transmitted PPFD reduced tomato fruit fresh mass and generally decreased the number of flowers ornamental on the species. Maximum photosynthetic rate (A_max), stomatal conductance (g_sw), and quantum yield of photosystem II (PhiPSII) consistently decreased as the percentage of blue light transmission decreased, but this did not correlate to biomass accumulation. An experimental red-fluorescent film had cultivar and species-specific effects on growth, highlighting both its potential for leafy greens and potential challenges for greenhouse crops with a greater quantum requirement. Full article

Alkyd resins are among the most common coatings used for exterior wood joinery. In Romania, solvent-borne alkyd coatings are widely used to finish wood. The study aims to compare the performance after 7 years of outdoor exposure of two types of alkyd coatings, a semi-transparent brown stain with micronized pigments (Alk1) and an opaque white enamel (Alk2), applied directly on wood or wood pre-treated with three types of resins: acryl-polyurethane (R1), epoxy (R2), and alkyd-polyurethane (R3). Fir (Abies alba) wood served as the substrate. Cracking, coating adhesion, and biological degradation were periodically assessed through visual inspection and microscopy. Additionally, a cross-cut test was performed, and the loss of coating on the directly exposed upper faces was measured using ImageJ. The results indicated that resin pretreatments somewhat reduced cracking but negatively affected coating adhesion after long-term exposure. All samples pretreated with resins and coated with Alk1 lost more than 50% (up to 78%) of the original finishing film by the end of the test. In comparison, coated control samples lost less than 50%. The Alk2 coating exhibited a film loss between 2% and 12%, compared to an average loss of 9% for the coated control. Overall, samples pretreated with alkyd-polyurethane resin (R3) and coated with alkyd enamel (Alk2) demonstrated the best performance in terms of cracking, adhesion, and discoloration. Full article

Building-integrated photovoltaic (BIPV) windows present a viable path towards carbon neutrality in the building sector. However, conventional BIPV windows, such as semi-transparent photovoltaic (STPV) glazings, still suffer from inadequate thermal insulation, which limits their effectiveness across different climate conditions. To address this issue, the cadmium telluride-based vacuum PV glazing has been developed to enhance the thermal performance of BIPV applications. To fully understand the complex thermal behaviour under real-world operational scenarios, this study introduces a one-dimensional transient heat transfer model that can efficiently capture the time-dependent thermal dynamics of this novel glazing system. Based on the numerical solutions using the explicit finite difference method (FDM), the temperature profile of the vacuum PV glazing can be obtained dynamically. Consequently, the heat gain of the semi-transparent vacuum PV glazing can be calculated under time-varying outdoor and indoor conditions. The validated heat transfer model was applied under four different scenarios, viz. summer daytime, summer nighttime, winter daytime, and winter nighttime, to provide a detailed analysis of the dynamic thermal behaviour, including the temperature variation and the energy flow. The dynamic thermal characteristics of the vacuum PV glazing calculated by the transient heat transfer model demonstrate its excellent thermal insulation and solar control capabilities. Moreover, the thermal performance of vacuum PV glazing was compared with a standard double-pane window under various weather conditions of a typical summer day and a typical winter day. The results indicate that the vacuum PV glazing can effectively minimise both heat gain and heat loss. The fluctuation of the inner surface temperature can be controlled within a limited range away from the set point of the indoor room temperature. Therefore, the vacuum PV glazing contributes to stabilising the temperature of the indoor environment despite the fluctuating solar radiation and periodic outdoor temperature. It is suggested that the vacuum PV glazing has the potential to enhance the climate adaptability of BIPV windows under different climate backgrounds. Full article

Timely and accurate detection of forest fires is crucial for protecting forest ecosystems. However, traditional monitoring methods face significant challenges in effectively detecting forest fires, primarily due to the dynamic spread of flames and smoke, irregular morphologies, and the semi-transparent nature of smoke, which make it extremely difficult to extract key visual features. Additionally, deploying these detection systems to edge devices with limited computational resources remains challenging. To address these issues, this paper proposes a lightweight hybrid receptive field model (LHRF-YOLO), which leverages deep learning to overcome the shortcomings of traditional monitoring methods for fire detection on edge devices. Firstly, a hybrid receptive field extraction module is designed by integrating the 2D selective scan mechanism with a residual multi-branch structure. This significantly enhances the model’s contextual understanding of the entire image scene while maintaining low computational complexity. Second, a dynamic enhanced downsampling module is proposed, which employs feature reorganization and channel-wise dynamic weighting strategies to minimize the loss of critical details, such as fine smoke textures, while reducing image resolution. Furthermore, a scale weighted Fusion module is introduced to optimize multi-scale feature fusion through adaptive weight allocation, addressing the issues of information dilution and imbalance caused by traditional fusion methods. Finally, the Mish activation function replaces the SiLU activation function to improve the model’s ability to capture flame edges and faint smoke textures. Experimental results on the self-constructed Fire-SmokeDataset demonstrate that LHRF-YOLO achieves significant model compression while further improving accuracy compared to the baseline model YOLOv11. The parameter count is reduced to only 2.25M (a 12.8% reduction), computational complexity to 5.4 GFLOPs (a 14.3% decrease), and mAP50 is increased to 87.6%, surpassing the baseline model. Additionally, LHRF-YOLO exhibits leading generalization performance on the cross-scenario M4SFWD dataset. The proposed method balances performance and resource efficiency, providing a feasible solution for real-time and efficient fire detection on resource-constrained edge devices with significant research value. Full article

Polymer composites with high dielectric permittivity (>10) and low dielectric loss are critical for energy storage and microelectronic applications. This study reports on a semi-transparent composite of a PVDF copolymer filled with Cu₇S₄ nanoparticles synthesized via a wet chemical route. Only a small content (6%) of copper sulfide increases the dielectric permittivity of the material from 10.4 to 15.9 (1 kHz), maintaining a low dielectric loss coefficient (less than 0.1). The incorporated nanoparticles affect the morphology of the composite film surface and crystalline phases in the whole volume, which was studied with FTIR spectroscopy, differential scanning calorimetry and scanning probe microscopy. Full article

Due to the diversity and semi-transparency of snowflakes, accurately locating and reconstructing background information during image restoration poses a significant challenge. Snowflakes obscure image details, thereby affecting downstream tasks such as object recognition and image segmentation. Although Convolutional Neural Networks (CNNs) and Transformers have achieved promising results in snow removal through local or global feature processing, residual snowflakes or shadows persist in restored images. Inspired by the recent popularity of State Space Models (SSMs), this paper proposes a Mamba-based multi-scale desnowing network (SnowMamba), which effectively models the long-range dependencies of snowflakes. This enables the precise localization and removal of snow particles, addressing the issue of residual snowflakes and shadows in images. Specifically, we design a four-stage encoder–decoder network that incorporates Snow Caption Mamba (SCM) and SE modules to extract comprehensive snowflake and background information. The extracted multi-scale snow and background features are then fed into the proposed Multi-Scale Residual Interaction Network (MRNet) to learn and reconstruct clear, snow-free background images. Extensive experiments demonstrate that the proposed method outperforms other mainstream desnowing approaches in both qualitative and quantitative evaluations on three standard image desnowing datasets. Full article

Smoke detection is crucial for early fire prevention and the protection of lives and property. Unlike generic object detection, smoke detection faces unique challenges due to smoke’s semitransparent, fluid nature, which often leads to false positives in complex backgrounds and missed detections—particularly around smoke edges and small targets. Moreover, high computational overhead further restricts real-world deployment. To tackle these issues, we propose RT-DETR-Smoke, a specialized real-time transformer-based smoke-detection framework. First, we designed a high-efficiency hybrid encoder that combines convolutional and Transformer features, thus reducing computational cost while preserving crucial smoke details. We then incorporated an uncertainty-minimization strategy to dynamically select the most confident detection queries, further improving detection accuracy in challenging scenarios. Next, to alleviate the common issue of blurred or incomplete smoke boundaries, we introduced a coordinate attention mechanism, which enhances spatial-feature fusion and refines smoke-edge localization. Finally, we propose the WShapeIoU loss function to accelerate model convergence and boost the precision of the bounding-box regression for multiscale smoke targets under diverse environmental conditions. As evaluated on our custom smoke dataset, RT-DETR-Smoke achieves a remarkable 87.75% mAP@0.5 and processes images at 445.50 FPS, significantly outperforming existing methods in both accuracy and speed. These results underscore the potential of RT-DETR-Smoke for practical deployment in early fire-warning and smoke-monitoring systems. Full article

While temperature, pH, DO, and ammonia nitrogen concentration are known to affect nitrous oxide (N₂O) emissions from ammonia-oxidizing bacteria (AOB), the specific responses of individual AOB species to these environmental variables have yet to be fully elucidated. The present study reports the isolation and pure culture of a new AOB strain, designated as N.eA1, from a stable CANON bioreactor. The strain’s denitrification and N₂O emission were systematically evaluated through a comprehensive analysis of growth kinetics, morphological characteristics, genetic composition, and nitrogen transformation under various environmental processes. Our results indicated that N.eA1 shares 95.33% sequence homology with Nitrosomonas europaea H1 AOB3, and exhibited higher nitrite (NO₂⁻-N) conversion efficiency. Morphological examination revealed white, semi-transparent spherical colonies. The bacterial growth kinetics included adaptation phase (0–12 h), exponential growth phase (12–36 h), stationary phase (36–72 h) and decline phase (after 72 h). Under optimal cultivation conditions (30 °C, DO concentration of 7.3 mg∙L⁻¹, pH 8.0, and NH₄⁺-N concentration of 260 mg∙L⁻¹), the culture achieved a maximum growth rate of 0.0723 h⁻¹, a maximum ammonia oxidation rate (AOR) of 10.74 mg∙(MLVSS∙h)⁻¹, and a minimum doubling time of 9.59 h. The peak time of nitrogen conversion was earlier than that of N₂O emission, with a maximum N₂O-N conversion from NH₄⁺-N of 1.039%. Full article

Semitransparent perovskite solar cells (PSCs) that possess a high-power conversion efficiency (PCE) and high average visible light transmittance (AVT) can be employed in applications such as photovoltaic windows. In this study, a bifacial modification comprising a buried layer of [4-(3,6-Dimethyl-9H-carbazol-9-yl) butyl] phosphonic acid (Me-4PACz) and a surface passivator of 2-(2-Thienyl) ethylamine hydroiodide (2-TEAI) was proposed to enhance device performance. When the concentrations of Me-4PACz and 2-TEAI were 0.3 mg/mL and 3 mg/mL, opaque PSCs with a 1.57 eV perovskite absorber achieved a PCE of 22.62% (with a V_OC of 1.18 V) and retained 88% of their original value after being stored in air for 1000 h. By substituting a metal electrode with an indium zinc oxide electrode, the resulting semitransparent PSCs showed a PCE of over 20% and an AVT of 9.45%. It was, therefore, suggested that the synergistic effect of Me-4PACz and 2-TEAI improved the crystal quality of perovskites and the carrier transport in devices. When employing an absorber with a wider bandgap (1.67 eV), the corresponding PSC obtained a higher AVT of 20.71% and maintained a PCE of 18.73%; these values show that a superior overall performance is observed compared to that in similar studies. This work is conductive to the future application of semitransparent PSCs. Full article

In the context of rapid decarbonization, photovoltaics (PV) has played a key role. Traditionally, PV installations require large land areas, leading to competition between PV and agriculture for land use. This conflict must be addressed as the demand for both energy and food continues to rise. Additionally, it poses broader challenges, potentially leading local communities to perceive PV energy production as a threat to their economic activities and food security. An emerging and promising solution is agrivoltaics (AV), a combination of agriculture and PV. AV comes in many different forms, ranging from the simple coexistence of crops and PV installations on the same patch of land to a full synergy of the two, producing better crops while also harvesting energy from the sun. This paper paints a complete picture of the scientific work produced so far throughout the field, with special attention to the use of third-generation PV and luminescent solar concentrators (LSCs). Both technologies minimize shading and enable wavelength selection and enrichment (when functionalized with fluorescent materials) to better align with the photosynthetic needs of plants. The viability of AV has also been evaluated from an economic standpoint. This work aims to assess the current landscape of AV research and to point out possible future developments. It also seeks to evaluate whether the advantages of semi-transparent devices are substantial enough to justify their development and employment on a scale comparable to traditional PV. Full article

The increasing demand for food and energy presents challenges for agricultural and energy sustainability, especially in regions with limited arable land. This study analyzed the productivity and morphological adaptations of Phaseolus vulgaris L. in agrivoltaic systems using monofacial, bifacial, and semi-transparent photovoltaic technologies under the high Andean climatic conditions of Chachapoyas, Amazonas, Peru. The evaluated varieties, Panamito and Chaucha, were cultivated with planting distances of 25 cm and 35 cm. The analyzed variables included plant height, number of trifoliate leaves, number of flowers, number and weight of pods, grain weight, and yield. The experiment was designed with plots under agrivoltaic systems and a conventional system as a control. Environmental parameters such as photosynthetically active radiation (PAR), irradiance, precipitation, leaf moisture, soil moisture, and ambient temperature were monitored. Results showed that the bifacial system with a planting density of 25 cm was the most efficient, recording a plant height of 139.38 cm, an average grain weight of 67.97 g, and a yield of 700.5 kg/ha, significantly surpassing the conventional system. These findings shows the potential of agrivoltaic systems to enhance agricultural production by efficiently utilizing solar radiation and land, providing an innovative solution for integrating agriculture and energy generation, as well as increasing productivity in scenarios with land-use competition and climatic challenges. Full article

Despite the huge progress achieved in the optimization of perovskite solar cell (PSC) performance, stability remains a limiting factor for technological commercialization. Here, a study on the photovoltaic, structural and morphological stability of semi-transparent formamidinium lead bromide-based PSCs is presented. This work focuses on the positive role of 2D nanoscale layer passivation, induced by perovskite surface treatment with a mixture of iso-Pentylammonium chloride (ISO) and neo-Pentylammonium chloride (NEO). In situ X-ray diffraction (XRD) is applied in combination with atomic force microscopy (AFM), and the results are correlated to the devices’ photovoltaic performances. The superior power conversion efficiency and overall stability of the ISO-NEO system is evidenced, as compared to the un-passivated device, under illumination in air. Furthermore, the role of the ISO-NEO treatments in increasing the morpho-structural stability is clarified as follows: a bulk effect resulting in a protective role against the loss in crystallinity of the perovskite 3D phase (observed only for the un-passivated device) and an interface effect, being the observed 2D phase crystallinity loss spatially localized at the interface with the 3D phase where a higher concentration of defects is expected. Importantly, the complete stability of the device is achieved with the passivated ISO-NEO-encapsulated device, allowing us to exclude the intrinsic degradation effects. Full article

This study investigates the empirical validity of the simple view of reading model in a semi-transparent language, Swedish, by using a large amount of reading test data from 11,791 students. Data were collected during the primary grades (year 1–3), which allowed us to test two aspects of the model: how much reading comprehension variance can be accounted for by decoding and language comprehension across primary grades (nine test occasions in total), and how decoding and language comprehension contribute to reading comprehension at each test occasion (three test occasions per grade). By using a latent variable framework, our findings indicated that nearly all reading comprehension variance was accounted for by decoding and language comprehension across each test occasion. Both decoding and language comprehension contributed to reading comprehension at all grades. While decoding contributed the most to reading comprehension variance at the first test occasions (grade 1), language comprehension became equally important in the middle of second grade. At the end of third grade, language comprehension outperformed decoding. This study shows that the simple view of reading model is highly usable for yet another semi-transparent language, which has practical implications for how to assess reading skills and, ultimately of how to inform reading instruction for beginner readers. Full article

Crack-templated thin films, inspired by naturally occurring patterns such as leaf venation, spider webs, and the networked structure of dried egg white, represent a paradigm shift in the design of functional materials. Traditionally, cracks in coatings are seen as defects to be avoided due to their potential to compromise mechanical integrity and performance. However, in this context, cracks are deliberately induced and meticulously controlled to serve as templates for versatile applications. This review explores the latest advances in preparation techniques, including solvent evaporation and thermal stress induction, with a focus on the interplay between material properties (e.g., polymers and ceramics) and process parameters (e.g., drying rates and temperature, layer thickness, substrate interactions) that govern crack behavior. The resulting crack patterns offer tunable features, such as density, width, shape, and orientation, which can be harnessed for applications in semitransparent electrodes, flexible sensors, and wearable and energy storage devices. Our study aims to navigate the advancements in crack engineering in the last 10 years and underscores its importance as a purposeful and versatile strategy for next-generation thin-film technologies, offering a novel and affordable approach to transforming perceived defects into assets for cutting-edge thin-film technologies. Full article

Long-term reliability is crucial for the commercialization of semi-transparent photovoltaic panels based on Luminescent Solar Concentrators (LSCs). This study addresses key challenges such as photodegradation and hail resistance using glazed LSC prototypes functionalized with organic Lumogen F dyes. A pilot-scale batch of LSC prototypes (10 × 10 cm²) underwent extensive outdoor exposure tests following the IEC 62108 “10.15 Outdoor Exposure Test” to evaluate long-term stability under natural solar radiation. Continuous monitoring revealed that prototypes with Lumogen F Red 305 experienced a 29% efficiency drop initially, which stabilized over time, indicating potential long-term stability. In contrast, those with Lumogen F Violet 570 showed minimal degradation, with only a 9% efficiency reduction. Additionally, the hail resistance of LSC panels was tested using the IEC 62108 “10.9 Hail Impact Test”. Panels with varying glass thickness, tempering methods, and surface areas were subjected to impact from 25 mm hailstones launched at 22.4 ± 5% m/s. All samples remained undamaged, highlighting their excellent hail resistance, a critical feature for preserving performance despite potential surface damage. This study demonstrates that combining glazed lightguides with polyvinyl butyral improves photostability and provides a cost-effective alternative to expensive fluorophores, while ensuring compliance with hail resistance standards. Full article