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16 pages, 3291 KiB  
Article
The Effects of Adding Extruded Highland Barley Flour on the Thermomechanical Properties of Wheat Flour Dough and the Overall Quality of Fresh Wet Noodles
by Yiqing Zhu, Xuecong Wang, Xinyu Zhang, Yan Du, Feng Liang, Fan Zhang, Chongyi Wu, Qingyu Zhao and Qun Shen
Foods 2024, 13(19), 3105; https://doi.org/10.3390/foods13193105 (registering DOI) - 28 Sep 2024
Abstract
Abstract: This study examined how adding extruded highland barley flour (EHBF) affects the thermomechanical properties of wheat flour dough and the overall quality of fresh wet noodles. EHBF increased the gel strength and pasting temperature of wheat flour compared to regular highland [...] Read more.
Abstract: This study examined how adding extruded highland barley flour (EHBF) affects the thermomechanical properties of wheat flour dough and the overall quality of fresh wet noodles. EHBF increased the gel strength and pasting temperature of wheat flour compared to regular highland barley flour. Moreover, higher EHBF levels reduced dough development time and stability time. EHBF improved the color and springiness of fresh wet noodles and decreased their cooking time and light transmittance relative to the color and springiness of the noodles in the control group. Notably, noodles with 20% EHBF showed a compact microstructure and received the highest sensory evaluation score. Adding EHBF lowered the estimated glycemic index of fresh wet noodles by reducing rapidly digestible starch and increasing slowly digestible starch and resistant starch contents. Thus, EHBF is a promising functional ingredient for enhancing the quality of fresh wet noodles. Full article
(This article belongs to the Section Food Engineering and Technology)
27 pages, 5440 KiB  
Article
A Single-Transmitter Multi-Receiver Wireless Power Transfer System with High Coil Misalignment Tolerance and Variable Power Allocation Ratios
by Yanting Luo, Zhuoyue Dai and Yongmin Yang
Electronics 2024, 13(19), 3838; https://doi.org/10.3390/electronics13193838 (registering DOI) - 28 Sep 2024
Abstract
This article proposes a single-transmitter multi-receiver wireless power transfer (STMR-WPT) system, which uses a cross-overlapped bipolar coil as the transmitter and multiple square unipolar coils as the receivers. By using this structure, the magnetic field of the system can be adjusted to accommodate [...] Read more.
This article proposes a single-transmitter multi-receiver wireless power transfer (STMR-WPT) system, which uses a cross-overlapped bipolar coil as the transmitter and multiple square unipolar coils as the receivers. By using this structure, the magnetic field of the system can be adjusted to accommodate different coil misalignment conditions. In addition, the proposed system uses C-CLCs networks to achieve separate load power allocation. Thus, relay coils, complex multi-frequency transmission channels and multiple independent power supplies can be avoided. A mapping impedance-based circuit model was established to analyze the characteristics of the system, and then a single-frequency power allocation method was presented. Through this method, the STMR-WPT system can achieve load power allocation at any specified ratios under different mutual inductance and load impedance conditions. Finally, an experimental STMR-WPT system was built. The side lengths of the transmitter and receiver coils are 400 mm and 160 mm, respectively. The measurement results indicated that when the lateral or longitudinal coil misalignment varies within the range of 0~200 mm, the coupling coefficient decreases by a maximum of 6% compared to the initial value, and when the angular coil misalignment varies within the range of 0~90 degrees, the coupling coefficient decreases by a maximum of 22% compared to the initial value. In four different power allocation scenarios, the experimental STMR-WPT system successfully achieved the expected power allocation goals. Full article
(This article belongs to the Special Issue Wireless Power Transfer Technology and Its Applications)
19 pages, 1421 KiB  
Article
Efficient Daylighting: The Importance of Glazing Transmittance and Room Surface Reflectance
by Isabel Escobar, Elvira Orduna-Hospital, Justiniano Aporta and Ana Sanchez-Cano
Buildings 2024, 14(10), 3108; https://doi.org/10.3390/buildings14103108 - 27 Sep 2024
Viewed by 182
Abstract
This study quantitatively analyzes the influence of the spectral characteristics, reflectance or transmittance, of different materials on the lighting of an interior space with natural and artificial light. For this purpose, a three-dimensional simulated classroom is used, where each of the components is [...] Read more.
This study quantitatively analyzes the influence of the spectral characteristics, reflectance or transmittance, of different materials on the lighting of an interior space with natural and artificial light. For this purpose, a three-dimensional simulated classroom is used, where each of the components is assigned specific materials with an associated reflectance or transmittance. Additionally, two types of lighting are available: 6500 K daylight and light from six continuous spectrum LED luminaires. The lighting is evaluated on two planes: the work plane and the corneal plane (80 cm and 120 cm from the floor, respectively). Three versions of the same classroom were analyzed by varying the walls (white, blue, and red), each with a different neutral-colored floor. Furthermore, calculations were performed in each situation considering two different types of glazing in the windows, with 20% and 88% transmittance. The photopic and melanopic lighting analysis was carried out with the ALFA calculation program to verify the necessary requirements for adequate lighting. The results show that the white classroom is the best lit, followed by the blue and finally the red, due to the reflectance characteristics of the walls and floor although slight differences among them are found. It was found that in some cases, additional auxiliary luminaires would be required for proper lighting depending on the transmittance of the glazing. This study highlights the critical role of material selection in optimizing both photopic and melanopic lighting, with practical implications for energy efficiency and occupant well-being in educational spaces. Full article
(This article belongs to the Special Issue Lighting in Buildings—2nd Edition)
13 pages, 5960 KiB  
Article
An Eight-Coil Wireless Power Transfer Method for Improving the Coupling Tolerance Based on Uniform Magnetic Field
by Suqi Liu, Xueying Yan, Guiqiang Xu, Gang Wang and Yuping Liu
Processes 2024, 12(10), 2109; https://doi.org/10.3390/pr12102109 - 27 Sep 2024
Viewed by 285
Abstract
In wireless power transfers (WPTs), it is challenging to obtain a constant output of power (COP) and constant transmission efficiency (CTE) in large coupling variation ranges. In this study, the eight-coil WPT system achieves a uniform magnetic field (UMF) in the transmitter and [...] Read more.
In wireless power transfers (WPTs), it is challenging to obtain a constant output of power (COP) and constant transmission efficiency (CTE) in large coupling variation ranges. In this study, the eight-coil WPT system achieves a uniform magnetic field (UMF) in the transmitter and receiver sides using two transmitting (Tx) coils and two receiving (Rx) coils, respectively. COP and CTE are then achieved with large coupling variation ranges. The circuit model and equations of the transmission characteristics are first obtained based on the structure and working principle of the Helmholtz coil. The model of the mutual inductance and equation of the impedance coupled factor are then developed. The laws of the transmission characteristic are also determined by adopting a simulation tool and equations of the transmission characteristics. Finally, the eight-coil WPT experimental system is designed. In a fixed-frequency mode, the COP and CTE are achieved when the coupling and misalignment distances are changed within a quarter or one-fifth of the relay coil diameter, respectively. This topology provides an efficient solution for problems faced in practical applications, such as wireless chargers of kitchen appliances and automatic mobile robots of small size. Full article
(This article belongs to the Section Energy Systems)
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21 pages, 1594 KiB  
Article
Characterization of the Virome Associated with the Ubiquitous Two-Spotted Spider Mite, Tetranychus urticae
by Lucas Yago Melo Ferreira, Anderson Gonçalves de Sousa, Joannan Lima Silva, João Pedro Nunes Santos, David Gabriel do Nascimento Souza, Lixsy Celeste Bernardez Orellana, Sabrina Ferreira de Santana, Lara Beatriz Correia Moreira de Vasconcelos, Anibal Ramadan Oliveira and Eric Roberto Guimarães Rocha Aguiar
Viruses 2024, 16(10), 1532; https://doi.org/10.3390/v16101532 - 27 Sep 2024
Viewed by 141
Abstract
Agricultural pests can cause direct damage to crops, including chlorosis, loss of vigor, defoliation, and wilting. In addition, they can also indirectly damage plants, such as by transmitting pathogenic micro-organisms while feeding on plant tissues, affecting the productivity and quality of crops and [...] Read more.
Agricultural pests can cause direct damage to crops, including chlorosis, loss of vigor, defoliation, and wilting. In addition, they can also indirectly damage plants, such as by transmitting pathogenic micro-organisms while feeding on plant tissues, affecting the productivity and quality of crops and interfering with agricultural production. Among the known arthropod pests, mites are highly prevalent in global agriculture, particularly those from the Tetranychidae family. The two-spotted spider mite, Tetranychus urticae, is especially notorious, infesting about 1600 plant species and causing significant agricultural losses. Despite its impact on agriculture, the virome of T. urticae is poorly characterized in the literature. This lack of knowledge is concerning, as these mites could potentially transmit plant-infecting viral pathogens, compromising food security and complicating integrated pest management efforts. Our study aimed to characterize the virome of the mite T. urticae by taking advantage of publicly available RNA deep sequencing libraries. A total of 30 libraries were selected, covering a wide range of geographic and sampling conditions. The library selection step included selecting 1 control library from each project in the NCBI SRA database (16 in total), in addition to the 14 unique libraries from a project containing field-collected mites. The analysis was conducted using an integrated de novo virus discovery bioinformatics pipeline developed by our group. This approach revealed 20 viral sequences, including 11 related to new viruses. Through phylogenetic analysis, eight of these were classified into the Nodaviridae, Kitaviridae, Phenuiviridae, Rhabdoviridae, Birnaviridae, and Qinviridae viral families, while three were characterized only at the order level within Picornavirales and Reovirales. The remaining nine viral sequences showed high similarity at the nucleotide level with known viral species, likely representing new strains of previously characterized viruses. Notably, these include the known Bean common mosaic virus (BCMV) and Phaseolus vulgaris alphaendornavirus 1, both of which have significant impacts on bean agriculture. Altogether, our results expand the virome associated with the ubiquitous mite pest T. urticae and highlight its potential role as a transmitter of important plant pathogens. Our data emphasize the importance of continuous virus surveillance for help in the preparedness of future emerging threats. Full article
(This article belongs to the Special Issue Molecular Virus-Insect Interactions 2nd Edition)
12 pages, 688 KiB  
Article
Angularly Selective Enhanced Vortex Screening in Extremely Layered Superconductors with Tilted Columnar Defects
by Gonzalo Rumi, Vincent Mosser, Marcin Konczykowski and Yanina Fasano
Condens. Matter 2024, 9(4), 37; https://doi.org/10.3390/condmat9040037 - 27 Sep 2024
Viewed by 181
Abstract
We report on two mechanisms of angularly selective enhanced screening in the solid vortex phase of extremely layered superconductors with tilted columnar defects (CDs). We study Bi2Sr2CaCu2O8+δ samples with different densities of CD tilted 45° [...] Read more.
We report on two mechanisms of angularly selective enhanced screening in the solid vortex phase of extremely layered superconductors with tilted columnar defects (CDs). We study Bi2Sr2CaCu2O8+δ samples with different densities of CD tilted 45° from the c-axis, and conduct local ac Hall magnetometry measurements, probing the sustainable current of the vortex system. We reveal two types of maxima in sustainable current for particular directions, detected as dips in the magnetic transmittivity of the vortex system. First, for a smaller number of vortices than of defects, an enhancement of screening is detected at an angular location Θdip1∼45° for H applied close to the direction of CD. For a larger number of vortices than of CD, Θdip1 decreases towards the ab-plane direction upon warming. Second, a pair of additional dips in transmittivity are detected at angles Θdip2 closer to, and quite symmetric with, the ab-plane. These two types of angularly selective enhanced screening reveal the effective pinning by tilted CD even for the composite vortex lattices nucleated in tilted fields in Bi2Sr2CaCu2O8+δ. Full article
(This article belongs to the Section Superconductivity)
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10 pages, 4702 KiB  
Article
Large Dynamic Range Spectral Measurement in Terahertz Region Based on Frequency Up-Conversion Detection via OH1 Crystal
by Jiasheng Yuan, Quanxin Guo, Xingyu Zhang, Naichang Liu, Xiaoqin Yin, Na Ming, Liyuan Guo, Binzhe Jiao, Kaiyu Wang and Shuzhen Fan
Sensors 2024, 24(19), 6245; https://doi.org/10.3390/s24196245 - 26 Sep 2024
Viewed by 240
Abstract
Terahertz spectroscopy systems, which integrate terahertz sources and detectors, have important applications in many fields such as materials science and security checking. Based on highly sensitive frequency up-conversion detection, large dynamic range spectral measurements in a terahertz region are reported. Our system realized [...] Read more.
Terahertz spectroscopy systems, which integrate terahertz sources and detectors, have important applications in many fields such as materials science and security checking. Based on highly sensitive frequency up-conversion detection, large dynamic range spectral measurements in a terahertz region are reported. Our system realized the detection sensitivity at a 10 aJ level with a 2-(3-(4-hydroxystyryl)-5,5-dime-thylcyclohex-2-enylidene) malononitrile (OH1) crystal and a dynamic range up to seven orders. Based on this system, we verified the validity of the spectral measurement with tests which were conducted on monohydrate glucose, anhydrous glucose and mixed tablet samples with a thickness of 0.8 mm in 1~3 THz, respectively. Also, a mini coppery elbow tube with an inner diameter of 1 mm was used for the transmission of a terahertz wave to simulate some strip biological tissue samples. By allowing terahertz to transmit through this tube filled with 0.5 g glucose powder, we successfully obtained the absorption spectrum with a minimum transmittance at the absorption peak in the order of 10−4. Full article
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21 pages, 1862 KiB  
Article
Game-Based Intelligent Jamming Strategy without Prior Information in Wireless Communications
by Yongcheng Li, Jinchi Wang, Zhenzhen Gao and Gangming Lv
Electronics 2024, 13(19), 3810; https://doi.org/10.3390/electronics13193810 - 26 Sep 2024
Viewed by 240
Abstract
Traditional jamming technologies have become less effective with the development of anti-jamming technologies, especially with the appearance of intelligent transmitters, which can adaptively adjust their transmission strategies. To deal with intelligent transmitters, in this paper, a game-based intelligent jamming scheme is proposed. Considering [...] Read more.
Traditional jamming technologies have become less effective with the development of anti-jamming technologies, especially with the appearance of intelligent transmitters, which can adaptively adjust their transmission strategies. To deal with intelligent transmitters, in this paper, a game-based intelligent jamming scheme is proposed. Considering that the intelligent transmitter has multiple transmission strategy sets whose prior probabilities are unknown to the jammer, we first model the interaction between the transmitter and the jammer as a dynamic game with incomplete information. Then the perfect Bayesian equilibrium is derived based on assumptions of some prior information. For more practical applications when no prior information about the transmitter is available at the jammer, a Q-learning-based method is proposed to find an intelligent jamming strategy by exploiting the sensing results of the wireless communications. The design of the jammer’s reward function is guided by the game utility and the reward is calculated based on the Acknowledgement/Negative Acknowledgement feedback of the receiver. Simulation results show that the proposed scheme has only 0.5% loss in jamming utility compared to that of the perfect Bayesian equilibrium strategy. Compared to existing jamming schemes, a higher packet error rate can be achieved by the proposed scheme by consuming less jamming power. Full article
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16 pages, 2934 KiB  
Article
Real-Time Simulation of Clear Sky Background Radiation in Gas Infrared Remote Sensing Monitoring
by Shengquan Shu, Jianguo Liu, Liang Xu, Yuhao Wang, Yasong Deng and Yongfeng Sun
Photonics 2024, 11(10), 904; https://doi.org/10.3390/photonics11100904 - 26 Sep 2024
Viewed by 254
Abstract
During the process of infrared remote sensing monitoring, obtaining real-time measurements of sky background radiation is extremely inconvenient. The current methods incur a certain amount of lag. In this study, within the existing theoretical framework, a fast transmittance calculation method using interpolation was [...] Read more.
During the process of infrared remote sensing monitoring, obtaining real-time measurements of sky background radiation is extremely inconvenient. The current methods incur a certain amount of lag. In this study, within the existing theoretical framework, a fast transmittance calculation method using interpolation was adopted, and a simplified transmission model was established. This led to the development of a new and simplified method for rapid temperature and humidity retrieval. Compared to the line-by-line integration method, the interpolation method significantly improves the speed of transmittance calculation by several tens of times, while maintaining a high level of accuracy. The relative deviation between the results obtained using the interpolation method and those obtained through line-by-line integration is less than 1 ‱. With the proposed method, temperature and humidity profile information can be retrieved from measured spectra within 5 min and corresponding background spectra can be obtained. The differences between the calculated background radiation and the measured spectra using the new method are smaller, making it more suitable for calculating sky background radiation. Additionally, the rapid retrieval results of the temperature profiles in the lower atmosphere have a certain level of accuracy (the mean deviation is less than 2 K). Full article
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14 pages, 3747 KiB  
Article
Investigation of Whitening Mechanism on Cultural Relic Surfaces Treated with Paraloid B72
by Xing Zhao, Xia Li, Siyu Zhang, Qing Niu, Zongmin Li and Cheng Xue
Coatings 2024, 14(10), 1240; https://doi.org/10.3390/coatings14101240 - 26 Sep 2024
Viewed by 254
Abstract
In the conservation of cultural relics, the application of Paraloid B72 in humid environments frequently results in the surface whitening of artifacts, which impairs their appearance and conceals important details. This study investigates the mechanisms underlying this phenomenon by examining the effect of [...] Read more.
In the conservation of cultural relics, the application of Paraloid B72 in humid environments frequently results in the surface whitening of artifacts, which impairs their appearance and conceals important details. This study investigates the mechanisms underlying this phenomenon by examining the effect of ambient humidity, Paraloid B72 mass concentration, solution addition volume, and solvent type. To evaluate the microstructure, transmittance, and composition of the films, a range of analytical techniques were employed, including optical microscopy, scanning electron microscopy, a UV-Visible Spectrophotometer, and Fourier transform infrared spectroscopy. The findings indicate that higher ambient humidity, lower Paraloid B72 mass concentration, smaller solution addition volume, and solvents with higher volatility and water miscibility increase water content during curing, intensifying the whitening effect. These factors modify the interaction between water and solvent, altering the surface structure of Paraloid B72. The whitening mechanism is linked to the cooling effect of solvent volatility, which lowers the dew point temperature at the air–solution interface, causing moisture condensation. Moisture forms droplets that leave irregular pores upon volatility, resulting in surface roughness, optical heterogeneity, and a reduced refractive index, resulting in whitening. This study provides a theoretical basis for understanding and preventing the whitening of Paraloid B72. Full article
(This article belongs to the Special Issue Coatings for Cultural Heritage: Cleaning, Protection and Restoration)
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19 pages, 11976 KiB  
Article
Synchronization of Chaotic Extremum-Coded Random Number Generators and Its Application to Segmented Image Encryption
by Shunsuke Araki, Ji-Han Wu and Jun-Juh Yan
Mathematics 2024, 12(19), 2983; https://doi.org/10.3390/math12192983 - 25 Sep 2024
Viewed by 239
Abstract
This paper proposes a highly secure image encryption technique based on chaotic synchronization. Firstly, through the design of a synchronization controller, we ensure that the master–slave chaotic extremum-coded random number generators (ECRNGs) embedded in separated transmitters and receivers are fully synchronized to provide [...] Read more.
This paper proposes a highly secure image encryption technique based on chaotic synchronization. Firstly, through the design of a synchronization controller, we ensure that the master–slave chaotic extremum-coded random number generators (ECRNGs) embedded in separated transmitters and receivers are fully synchronized to provide synchronized dynamic random sequences for image encryption applications. Next, combining these synchronized chaotic sequences with the AES encryption algorithm, we propose an image segmentation and multi-encryption method to enhance the security of encrypted images and realize a secure image transmission system. Notably, in the design of the synchronization controller, the transient time before complete synchronization between the master and slave ECRNGs is effectively controlled by specifying the eigenvalues of the matrix in the synchronization error dynamics. Research results in this paper also show that complete synchronization of ECRNGs can be achieved within a single sampling time, which significantly contributes to the time efficiency of the image transmission system. As for the image encryption technique, we propose the method of image segmentation and use the synchronized dynamic random sequences generated by the ECRNGs to produce the keys and initialization vectors (IVs) required for AES-CBC image encryption, greatly enhancing the security of the encrypted images. To highlight the contribution of the proposed segmented image encryption, statistical analyses are conducted on the encrypted images, including histogram analysis (HA), information entropy (IE), correlation coefficient analysis (CCA), number of pixels change rate (NPCR), and unified average changing intensity (UACI), and compared with existing literature. The comparative results fully demonstrate that the proposed encryption method significantly enhances image encryption performance. Finally, under the network transmission control protocol (TCP), the synchronization of ECRNGs, dynamic keys, and IVs is implemented as well as segmented image encryption and transmission, and a highly secure image transmission system is realized to validate the practicality and feasibility of our design. Full article
(This article belongs to the Special Issue New Advances in Coding Theory and Cryptography, 2nd Edition)
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30 pages, 7159 KiB  
Article
Performance-Oriented Parametric Optimization Design for Energy Efficiency of Rural Residential Buildings: A Case Study from China’s Hot Summer and Cold Winter Zone
by Meiyan Wang, Ying Xu, Runtian Shen and Yun Wu
Sustainability 2024, 16(19), 8330; https://doi.org/10.3390/su16198330 - 25 Sep 2024
Viewed by 553
Abstract
With the implementation of the rural revitalization strategy, rural residences have become an essential component of China’s building energy conservation efforts. However, most existing research has focused more on urban buildings, with less attention given to rural residences. This study, taking rural residential [...] Read more.
With the implementation of the rural revitalization strategy, rural residences have become an essential component of China’s building energy conservation efforts. However, most existing research has focused more on urban buildings, with less attention given to rural residences. This study, taking rural residential buildings (RRBs) in the hot summer and cold winter zones in China as an example, proposes a more precise, two-stage optimization design framework using Rhino-Grasshopper for the overall optimization of RRBs. First, field surveys and numerical analysis of collected rural residential design drawings were conducted to clarify spatial characteristics and air conditioning usage. The parametric optimization design of RRBs was then conducted in two steps. The first step involves room function positioning, where spatial geometric models are established. Annual dynamic simulation analyses of AC (air conditioning) and AL (artificial lighting) energy consumption are performed to obtain energy intensity distribution maps. Based on the principle that “space with higher energy consumption is set in the location with lower energy consumption intensity” and the habit of functional space distribution, room function positioning, and adjustments are made. In the second step, the SPEA-2 genetic algorithm was applied for multi-objective optimization of room width, depth, WWR (window-to-wall ratio), SHGC (solar heat gain coefficient), and VLT (visible light transmittance), all based on the logical relationships of the building structure. The final Pareto front solution sets were obtained by multi-objective optimization simulation (MOO). A typical three-bay RRB was selected for application in this study, and the optimized design led to a total energy savings rate of 11% in annual AC and AL energy consumption. Full article
(This article belongs to the Section Green Building)
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24 pages, 7962 KiB  
Article
Study of Factors Affecting UV-Induced Photo-Degradation in Different Types of Polyethylene Sheets
by Bochu Du, Chenghao Lee and Ying Ji
Polymers 2024, 16(19), 2709; https://doi.org/10.3390/polym16192709 - 25 Sep 2024
Viewed by 341
Abstract
Enhancing the degradability of polyethylene plastics could provide a potential solution to the overwhelming crisis of plastic waste. Conventional studies have focused on the degradation of polyethylene thin films. This study investigated UV-induced photo-degradation according to ASTM D5208-14 in polyethylene sheets with thicknesses [...] Read more.
Enhancing the degradability of polyethylene plastics could provide a potential solution to the overwhelming crisis of plastic waste. Conventional studies have focused on the degradation of polyethylene thin films. This study investigated UV-induced photo-degradation according to ASTM D5208-14 in polyethylene sheets with thicknesses ranging from 0.4 to 1.2 mm. The impacts of sample thickness, metal pro-oxidants, polyethylene resin types and foaming were explored through the characterization of the carbonyl index, molecular weight, tensile properties and crystallinity. As pro-oxidants, single iron or manganese stearate demonstrated a concentration-dependent trend in accelerating the photo-degradation of polyethylene sheets. The thickness, foaming and resin type—such as low-density polyethylene (LDPE) and high-density polyethylene (HDPE)—significantly impacted the rate of photo-oxidation. Thick polyethylene sheets (1.2 mm) exhibited a heterogenous and depth-dependent degradation profile. As the photo-degradation progressed, the enhanced crystallinity, reduced UV transmittance and formation of crosslinks were able to prevent further oxidative cleavage of the polyethylene chain. This study investigated the time course and factors affecting the photo-degradation of polyethylene sheets, which could provide insights into the formulation design of photo-degradable polyethylene plastics. Full article
(This article belongs to the Section Circular and Green Polymer Science)
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13 pages, 5241 KiB  
Article
Functional UV Blocking and Superhydrophobic Coatings Based on Functionalized CeO2 and Al2O3 Nanoparticles in a Polyurethane Nanocomposite
by Miguel Angel Velasco-Soto, Arturo Román Vázquez-Velázquez, Sergio Alfonso Pérez-García, Lilia Magdalena Bautista-Carrillo, Pavel Vorobiev, Abraham Méndez-Reséndiz and Liliana Licea-Jiménez
Polymers 2024, 16(19), 2705; https://doi.org/10.3390/polym16192705 - 25 Sep 2024
Viewed by 293
Abstract
Water repellency has significant potential in applications like self-cleaning coatings, anti-staining textiles, and electronics. This study introduces a novel nanocomposite system incorporating functionalized Al2O3 and CeO2 nanoparticles within a polyurethane matrix to achieve hydrophobic and UV-blocking properties. The nanoparticles [...] Read more.
Water repellency has significant potential in applications like self-cleaning coatings, anti-staining textiles, and electronics. This study introduces a novel nanocomposite system incorporating functionalized Al2O3 and CeO2 nanoparticles within a polyurethane matrix to achieve hydrophobic and UV-blocking properties. The nanoparticles were functionalized using an octadecyl phosphonic acid solution and characterized by FTIR and XPS, confirming non-covalent functionalization. Spin-coated polyurethane coatings with functionalized and non-functionalized Al2O3, CeO2, and binary Al2O3-CeO2 nanoparticles were analyzed. The three-layered Al2O3-CeO2-ODPA binary system achieved a contact angle of 166.4° and 85% transmittance in the visible range. Incorporating this binary functionalized system into a 0.4% w/v polyurethane solution resulted in a nanocomposite with 75% visible transmittance, 60% at 365 nm UV, and a 147.7° contact angle after three layers. These findings suggest that ODPA-functionalized nanoparticles, when combined with a polymer matrix, offer a promising approach to developing advanced hydrophobic and UV-protective coatings with potential applications across various industrial sectors. Full article
(This article belongs to the Special Issue Advances in Functional Polymer Coatings and Surfaces)
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34 pages, 4554 KiB  
Article
Early Mission Calibration Performance of NOAA-21 VIIRS Reflective Solar Bands
by Ning Lei, Xiaoxiong Xiong, Kevin Twedt, Sherry Li, Tiejun Chang, Qiaozhen Mu and Amit Angal
Remote Sens. 2024, 16(19), 3557; https://doi.org/10.3390/rs16193557 - 24 Sep 2024
Viewed by 368
Abstract
The Visible Infrared Imaging Radiometer Suite (VIIRS) is one of the key instruments on the recently launched NOAA-21 (previously known as JPSS-2) satellite. The VIIRS, like its predecessors on the SNPP and NOAA-20 satellites, provides daily global coverage in 22 spectral bands from [...] Read more.
The Visible Infrared Imaging Radiometer Suite (VIIRS) is one of the key instruments on the recently launched NOAA-21 (previously known as JPSS-2) satellite. The VIIRS, like its predecessors on the SNPP and NOAA-20 satellites, provides daily global coverage in 22 spectral bands from 412 nm to 12 μm. The geometrically and radiometrically calibrated observations are the basis for many operational applications and scientific research studies. A total of 14 of the 22 bands are reflective solar bands (RSBs), covering photon wavelengths from 412 nm to 2.25 μm. The RSBs were radiometrically calibrated prelaunch and have been regularly calibrated on orbit through the onboard solar diffuser (SD) and scheduled lunar observations. The on-orbit SD’s reflectance change is determined by the onboard solar diffuser stability monitor (SDSM). We review the calibration algorithms and present the early mission performance of the NASA N21 VIIRS RSBs. Using the calibration data collected at both the yaw maneuver and regular times, we derive the screen transmittance functions. The visible and near-infrared bands’ radiometric gains have been stable, nearly independent of time, and so were the radiometric gains of the shortwave-infrared bands after the second mid-mission outgassing. Further, we assess the Earth-view striping observed in the immediate prior collection (Collection 2.0) and apply a previously developed algorithm to mitigate the striping. The N21 VIIRS RSB detector signal-to-noise ratios are all above the design values with large margins. Finally, the uncertainties of the retrieved Earth-view top-of-the-atmosphere spectral reflectance factors at the respective typical spectral radiance levels are estimated to be less than 1.5% for all the RSBs, except band M11 whose reflectance factor uncertainty is 2.2%. Full article
(This article belongs to the Section Satellite Missions for Earth and Planetary Exploration)
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