bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of an Extremely Low-Frequency Electromagnetic Field on the Drought Sensitivity of Wheat Plants
Authors: Mshenskaya N. S. , Grinberg M. A. , Kalyasova E. A. , Vodeneev V. A. , Ilin N. V. , Slyunyaev N. N. , Mareev E. A. , Sinitsyna Y. V.
Published: February 2023

Extremely low-frequency magnetic fields are thought to be capable of modulating the resistance of plants to adverse factors, particularly drought. Magnetic fields in this frequency range occur in nature in connection with so-called Schumann resonances, excited by lightning discharges in the Earth–ionosphere cavity. The aim of this work was to identify the influence of a magnetic field with a frequency of 14.3 Hz (which corresponds to the second Schumann harmonic) on the transpiration and photosynthesis of wheat plants under the influence of drought. The activity of photosynthesis processes, the crop water stress index, relative water content and leaf area were determined during drought intensification. At the end of the experiment, on the 12th day of drought, the length, and fresh and dry weight of wheat shoots were measured. The results obtained indicate a protective effect of the magnetic field on plants in unfavorable drought conditions; the magnetic field delayed the development of harmful changes in the transpiration and photosynthesis processes for several days. At the same time, in the absence of the stressor (drought), the effect of the electromagnetic field was not detected, except for a decrease in relative transpiration. In favorable conditions, there were only minimal modifications of the photosynthetic processes and transpiration by the magnetic field.
The Methylene Spacer Matters: The Structural and Luminescent Effects of Positional Isomerism of n-Methylpyridyltriazole Carboxylate Semi-Rigid Ligands in the Structure of Zn(II) Based Coordination Polymers
Authors: Narea Pilar , Hernández Benjamín , Cisterna Jonathan , Cárdenas Alejandro , Amo-Ochoa Pilar , Zamora Félix , Delgado Gerzon E. , Llanos Jaime , Brito Iván
Published: February 2023

Two Zn(II) coordination polymers (CPs) based on n-methylpyridyltriazole carboxylate semi-rigid organic ligands (n-MPTC), with n = 3 (L1) and 4 (L2), have been prepared at the water n-butanol interphase by reacting Zn(NO3)2·4H2O with NaL1 and NaL2. This allows us to systematically investigate the influence of the isomeric positional effect on their structures. The organic ligands were obtained by saponification from their respective ester precursors ethyl-5-methyl-1-(pyridin-3-ylmethyl)-1H-1,2,3-triazole-4-carboxylate (P1) and ethyl-5-methyl-1-(pyridin-4-ylmethyl)-1H-1,2,3-triazole-4-carboxylate (P2), resulting in their corresponding sodium salt forms, 3-MPTC, and 4-MPTC. The structure of the Zn(II) CPs determined by single-crystal X-ray diffraction reveals that both CPs have 2D supramolecular hydrogen bond networks. The 2D supramolecular network of [Zn(L1)]n (1) is built up by hydrogen bond interactions between oxygen and hydrogen atoms between neighboring n-methylpyridyltriazole molecules, whereas in [Zn(L2)·4H2O]n (2) the water molecules link 1D polymeric chains forming a 2D supramolecular aggregate. The structures of 1 and 2 clearly show that the isomeric effect in the semi-rigid ligands plays a vital role in constructing the Zn(II) coordination polymers, helped by the presence of the methylene spacer group, in the final structural conformation. The structures of 1 and 2 significantly affect their luminescent properties. Thus, while 2 shows strong emission at room temperature centered at 367 nm, the emission of 1 is quenched substantially.
Experimental and Computational Exploration of Chitin, Pectin, and Amylopectin Polymers as Efficient Eco-Friendly Corrosion Inhibitors for Mild Steel in an Acidic Environment: Kinetic, Thermodynamic, and Mechanistic Aspects
Authors: Fawzy Ahmed , Toghan Arafat , Alqarni Nada , Morad Moataz , Zaki Magdi E. A. , Sanad Moustafa M. S. , Alakhras Abbas I. , Farag Ahmed A.
Published: February 2023

Herein, the inhibition impacts of chitin, pectin, and amylopectin as carbohydrate polymers on the corrosion of mild steel in 0.5 M HCl were researched utilizing various experimental and theoretical tools. The acquired outcomes showed that the inhibition efficiencies (% IEs) of the tested carbohydrate polymers were increased by raising their concentrations and these biopolymers acting as mixed-kind inhibitors with major anodic ones. The acquired % IEs values were reduced with rising temperature. The higher % IEs of the tested polymers were inferred via powerful adsorption of the polymeric molecules on the steel surface and such adsorption obeyed the Langmuir isotherm. The computed thermodynamic and kinetic quantities confirmed the mechanism of physical adsorption. The kinetics and mechanisms of corrosion and its protection by polymeric compounds were illuminated. The results obtained from all the techniques used confirmed that there was good agreement with each other, and that the % of IEs followed the sequence: chitin > amylopectin > pectin.
High-Strength Bio-Degradable Polymer Foams with Stable High Volume-Expansion Ratio Using Chain Extension and Green Supercritical Mixed-Gas Foaming
Authors: Long Haoyu , Xu Hongsen , Shaoyu Jingwen , Jiang Tianchen , Zhuang Wei , Li Ming , Jin Junyang , Ji Lei , Ying Hanjie , Zhu Chenjie
Published: February 2023

The preparation of biodegradable polymer foams with a stable high volume-expansion ratio (VER) is challenging. For example, poly (butylene adipate-co-terephthalate) (PBAT) foams have a low melt strength and high shrinkage. In this study, polylactic acid (PLA), which has a high VER and crystallinity, was added to PBAT to reduce shrinkage during the supercritical molded-bead foaming process. The epoxy chain extender ADR4368 was used both as a chain extender and a compatibilizer to mitigate the linear chain structure and incompatibility and improve the foamability of PBAT. The branched-chain structure increased the energy-storage modulus (G’) and complex viscosity (η*), which are the key factors for the growth of cells, by 1–2 orders of magnitude. Subsequently, we innovatively used the CO2 and N2 composite gas method. The foam-shrinkage performance was further inhibited; the final foam had a VER of 23.39 and a stable cell was obtained. Finally, after steam forming, the results showed that the mechanical strength of the PBAT/PLA blended composite foam was considerably improved by the addition of PLA. The compressive strength (50%), bending strength, and fracture load by bending reached 270.23 kPa, 0.36 MPa, and 23.32 N, respectively. This study provides a potential strategy for the development of PBAT-based foam packaging materials with stable cell structure, high VER, and excellent mechanical strength.
Preparation and In Vitro Evaluation of Chitosan-g-Oligolactide Based Films and Macroporous Hydrogels for Tissue Engineering
Authors: Tolstova Tatiana , Drozdova Maria , Popyrina Tatiana , Matveeva Diana , Demina Tatiana , Akopova Tatiana , Andreeva Elena , Markvicheva Elena
Published: February 2023

In the current study, novel matrices based on chitosan-g-oligo (L,L-/L,D-lactide) copolymers were fabricated. In particular, 2D films were prepared by solvent casting, while 3D macroporous hydrogels were obtained by lyophilization of copolymer solutions. Copolymers of chitosan (Chit) with semi-crystalline oligo (L,L-lactide) (Chit-LL) or amorphous oligo (L,D-lactide) (Chit-LD) were obtained by solid-state mechanochemical synthesis. The structure of the hydrogels was found to be a system of interconnected macropores with an average size of 150 μm. In vitro degradation of these copolymer-based matrices was shown to increase in the case of the Chit-LL-based hydrogel by 34% and decrease for the Chit-LD-based hydrogel by 23% compared to the parameter of the Chit sample. Localization and distribution of mouse fibroblast L929 cells and adipose tissue-derived mesenchymal stromal cells (MSCs) within the hydrogels was studied by confocal laser scanning microscopy (CLSM). Moreover, cellular response, namely cell adhesion, spreading, growth, proliferation, as well as cell differentiation in vitro were also evaluated in the hydrogels for 10–14 days. Both the Chit-LL and Chit-LD matrices were shown to support cell growth and proliferation, while they had improved swelling compared to the Chit matrix. Osteogenic MSCs differentiation on the copolymer-based films was studied by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). Maximal expression levels of osteogenesis markers (alkaline phosphatase (ALPL), bone transcription factor (Runx2), and osteopontin (SPP1) were revealed for the Chit-LD films. Thus, osteodifferentiation was demonstrated to depend on the film composition. Both Chit-LL and Chit-LD copolymer-based matrices are promising for tissue engineering.
Enhancement of Luminescence of PET Films after Swift Heavy Ion Irradiation
Authors: Tuleushev Adil Z. , Harrison Fiona E. , Kozlovskiy Artem L. , Zdorovets Maxim V.
Published: February 2023

The novelty of the study is that the ordering that occurs in a PET film under the action of SHI irradiation manifests itself as an increase in the integral intensity of intrinsic luminescence. The Urbach behaviour of the red shift of the absorption edge is used as a baseline for further analysis of experimental optical transmission spectra of PET films irradiated by swift heavy ions (SHI) previously published by the authors. Negative deviations of the experimental spectra from the Urbach baseline in the visible and UV parts of the spectrum are attributed to enhanced by SHI irradiation intrinsic luminescence. The observed dependence of the integral intensity of luminescence of irradiated PET films on the SHI fluence and ion charge provides further confirmation of the presence of SHI-induced ordering of the molecular structure in SHI latent tracks.
2,6-Diaminopyridine-Based Polyurea as an ORR Electrocatalyst of an Anion Exchange Membrane Fuel Cell
Authors: Wang Yen-Zen , Hsieh Tar-Hwa , Huang Yu-Chang , Ho Ko-Shan
Published: February 2023

In order to yield more Co(II), 2,6-diaminopyridine (DAP) was polymerized with 4,4-methylene diphenyl diisocyanates (MDI) in the presence of Co(II) to obtain a Co-complexed polyurea (Co-PUr). The obtained Co-PUr was calcined to become Co, N-doped carbon (Co–N–C) as the cathode catalyst of an anion exchange membrane fuel cell (AEMFC). High-resolution transmission electron microscopy (HR-TEM) of Co–N–C indicated many Co-Nx (Co covalent bonding with several nitrogen) units in the Co–N–C matrix. X-ray diffraction patterns showed that carbon and cobalt crystallized in the Co–N–C catalysts. The Raman spectra showed that the carbon matrix of Co–N–C became ordered with increased calcination temperature. The surface area (dominated by micropores) of Co–N–Cs also increased with the calcination temperature. The non-precious Co–N–C demonstrated comparable electrochemical properties (oxygen reduction reaction: ORR) to commercial precious Pt/C, such as high on-set and half-wave voltages, high limited reduction current density, and lower Tafel slope. The number of electrons transferred in the cathode was close to four, indicating complete ORR. The max. power density (Pmax) of the single cell with the Co–N–C cathode catalyst demonstrated a high value of 227.7 mWcm−2.
Application of Lavender-Oil Microcapsules to Functionalized PET Fibers
Authors: Valle Rita de Cássia Siqueira Curto , Valle José Alexandre Borges , Bezerra Fabricio Maestá , Correia Jeferson , da Costa Cristiane , Martí Meritxell , Coderch Luisa , López Arianne , Arias Manuel J. Lis
Published: February 2023

Surface treatments for textile substrates have received significant attention from researchers around the world. Ozone and plasma treatments trigger a series of surface alterations in textile substrates that can improve the anchoring of other molecules or particles on these substrates. This work aims to evaluate the effect of ozone and plasma treatments on the impregnation of polymeric microcapsules containing lavender oil in polyester fabrics (PES). Microcapsules with walls of chitosan and gum arabic were prepared by complex coacervation and impregnated in PES, plasma-treated PES, and ozone-treated PES by padding. The microcapsules were characterized for their size and morphology and the surface-treated PES was evaluated by FTIR, TGA, SEM, and lavender release. The microcapsules were spherical in shape, with smooth surfaces. The FTIR analyses of the textile substrates with microcapsules showed bands referring to the polymers of the microcapsules, but not to the lavender; this was most likely because the smooth surface of the outer wall did not retain the lavender. The mass loss and the degradation temperatures measured by TGA were similar for all the ozone-treated and plasma-treated polyester samples. In the SEM images, spherical microcapsules and the impregnation of the microcapsules of larger sizes were perceived. Through the lavender release, it was observed that the plasma and ozone treatments interfered both with the amount of lavender delivered and with the control of the delivery.
Construction of CNC@SiO2@PL Based Superhydrophobic Wood with Excellent Abrasion Resistance Based on Nanoindentation Analysis and Good UV Resistance
Authors: Zhang Zhupeng , Ren Changying , Sun Yi , Miao Yu , Deng Lan , Wang Zepeng , Cao Yizhong , Zhang Wenbiao , Huang Jingda
Published: February 2023

Construction of superhydrophobic woods with high abrasion resistance is still a major challenge, and micro analysis for abrasion resistance is scarce. To improve these issues, cellulose nanocrystals (CNC)@SiO2@phosphorylated lignin (PL) rods were prepared by SiO2 in situ generated on CNC, and then the modified lignin attached to the CNC@SiO2 rods surface. Subsequently, the superhydrophobic coating was constructed using hydrophobic modified CNC@SiO2@PL rods as the main structural substance by simple spraying or rolling them onto wood surfaces, and both polydimethylsiloxane (PDMS) and epoxy resin were used as the adhesives. The resulting coating had excellent superhydrophobic properties with a water contact angle (WCA) of 157.4° and a slide angle (SA) of 6°. The introduced PL could enhance ultraviolet (UV) resistance of the coating due to the presence of these groups that absorbed UV light in lignin. In the abrasion resistance test, compared with the SiO2/PL coating, the abrasion resistance of the one with CNC was much higher, suggesting that CNC could improve the abrasion resistance of the coating due to its high crystallinity and excellent mechanical strength. The coating with PDMS performed better than the one with epoxy resin because the soft surface could offset part of the external impact by deformation in the abrasion process. This was also consistent with the results of the nanoindentation (NI) tests. In view of the simple preparation and good performance, this superhydrophobic wood will have broad application potential.
Anti-Inflammatory and Anti-Diabetic Activity of Ferruginan, a Natural Compound from Olea ferruginea
Authors: Rauf Abdur , Rashid Umer , Shah Zafar Ali , Rehman Gauhar , Bashir Kashif , Jamil Johar , Iftikhar  , Rahman Abdur , Alsahammari Abdulrahman , Alharbi Metab , Al-Shahrani Abdulmajeed , Ribaudo Giovanni
Published: February 2023

Inflammation is a complex response of the human organism and relates to the onset of various disorders including diabetes. The current research work aimed at investigating the anti-inflammatory and anti-diabetic effects of ferruginan, a compound isolated from Olea ferruginea. Its in vitro anti-inflammatory activity was determined by using the heat-induced hemolysis assay, while the anti-diabetic effect of the compound was studied by the yeast cell glucose uptake assay. Ferruginan exhibited a maximum of 71.82% inhibition of inflammation and also increased the uptake of glucose by yeast cells by up to 74.96% at the highest tested concentration (100 µM). Moreover, ferruginan inhibited α-amylase dose-dependently, by up to 75.45% at the same concentration. These results indicated that ferruginan possesses promising anti-inflammatory and anti-diabetic properties in vitro, even if at high concentrations. To provide preliminary hypotheses on the potentially multi-target mechanisms underlying such effects, docking analyses were performed on α-amylase and on various molecular targets involved in inflammation such as 5′-adenosine monophosphate-activated protein kinase (AMPK, PDB ID 3AQV), cyclooxygenase (COX-1, PDB ID 1EQG, and COX-2, 1CX2), and tumor necrosis factor alpha (TNF-α, PDB ID 2AZ5). The docking studies suggested that the compound may act on α-amylase, COX-2, and AMPK.
Menthol and Fatty Acid-Based Hydrophobic Deep Eutectic Solvents as Media for Enzyme Activation
Authors: Elgharbawy Amal , Syed Putra Sharifah , Khan Huma , Azmi Nor , Sani Muhamad , Ab llah Nazurah , Hayyan Adeeb , Jewaratnam Jegalakshimi , Basirun Wan
Published: February 2023

This research aims to provide insights into the biological efficacy of a newly formed hydrophobic deep eutectic solvent (DES). A DES based on menthol was successfully synthesized with fatty acids. The DESs’ properties as enzyme activators were examined against a neat counterpart. The menthol:decanoic acid (1:1) combination showed improved thermal stability, strong catalytic activity, and reusability for up to four subsequent cycles under ideal conditions (pH 7.0, 40 °C for 2 h). The hydrophobic DES replaced hexane in ester synthesis, where RNL@DES5 showed better fatty acid conversion compared to neat RNL. This study demonstrated promising applications of hydrophobic DESs in non-aqueous organic reactions.
An Investigation of Microstructure Characteristic and Sulfide Stress Cracking Behavior of 110 ksi Cr-Mo Grade Casing Steel
Authors: Lu Caihong , Zhang Hui , Li Dening , Han Lihong , Wang Jianjun , Li Jun , Qi Yue , Li Fangpo , Tian Yudong
Published: February 2023

The sulfide stress cracking (SSC) behavior of three micro-alloying 110 ksi grade Cr-Mo casing steels were evaluated according to the A-Method tensile test specified in the NACE TM0177 standard (NACE A-method). The fractures of SSC specimens and the micro-structures of the casing steels were characterized by scanning electron microscopy (SEM) with electron backscattering diffraction (EBSD) and transmission electron microscopy (TEM) in the BF and STEM mode. The results show that on the premise of 110 ksi, the yield strength of Co-Mo steel was satisfactory, finer spherical carbides increased the number of irreversible traps; widened polygonised martensitic laths, lowered dislocation density, and lowered the proportion of high-angle grain boundaries and the Σ3 boundaries decreased hydrogen permeability and diffusivity. The SSC resistance of Co-Mo steel with above micro structure characteristics was enhanced.
Game Analysis of the Influence of the Miner under Carbon Emotion on the Intelligent Development Strategies of the SMEE in Coal Mines
Authors: Yuan Xiaofang , Wu Yutong , Sun Linhui , Wang Xinping
Published: February 2023

The intelligent development of coal mines is a crucial way to achieve the safe, efficient, green, and low-carbon transformation of the coal industry and to reach the “double carbon” target, which is related to the life and health of miners, the stable development of enterprises and the national energy reform. As directly affected subjects, the cooperative attitudes of miners in different emotional states have a significant impact on the smooth implementation of intelligent coal mine renovation projects. Hence, we combined the RDEU theory and game theory, constructed a three-party evolutionary game model of the small and medium-sized energy enterprises (SMEE), the government, and the miner, considered the influence of the strategies made by the miner on the equilibrium strategy choices of other game subjects in the intelligent coal mine construction under the rational and irrational emotional states of the miner, and finally used MATLAB 2021 to simulate and analyze the impact of the evolution of the gaming system from 3 key elements: initial participation rate, construction costs, and government support. The study found the following: (1) The government will insist on actively promoting intelligent coal mine construction regardless of the miner’s emotional state. (2) Both moderate pessimism and optimism will, to a certain extent, give a positive impetus to the development of intelligent coal mine construction. (3) The miner’s emotions have a greater impact on SMEE than on the government’s strategic behavior. (4) Excessive construction costs or low government support will make SMEE may reduce the enthusiasm of SMEE to carry out an intelligent construction of coal mines. Accordingly, corresponding suggestions and countermeasures are put forward, aiming to provide targeted and practical ideas for the efficient construction of intelligent coal mines in China, thereby accelerating the green and low-carbon transformation of energy.
Autonomous Liquid–Liquid Extraction Operation in Biologics Manufacturing with Aid of a Digital Twin including Process Analytical Technology
Authors: Uhl Alexander , Schmidt Axel , Hlawitschka Mark W. , Strube Jochen
Published: February 2023

Liquid–liquid extraction has proven to be an aid in biologics manufacturing for cell and component separation. Because distribution coefficients and separation factors can be appropriately adjusted via phase screening, especially in aqueous two-phase systems, one stage is frequently feasible. For biologics separation, aqueous two-phase systems have proven to be feasible and efficient. The simple mixer–settler equipment type is still not standard in biologics manufacturing operations. Therefore, a scalable digital twin would be of aid for operator training, process design under the regulatory demanded quality by design approach for risk analysis, design and control space definition, and predictive maintenance. Autonomous operation is achieved with the aid of process analytical technology to update the digital twin to real time events and to allow process control near any optimal operation point. Autonomous operation is first demonstrated with an experimental feasibility study based on an industrial type example of pDNA manufacturing via lysis from E. coli with and without cell separation performance.
Risk Assessment of Unsafe Acts in Coal Mine Gas Explosion Accidents Based on HFACS-GE and Bayesian Networks
Authors: Niu Lixia , Zhao Jin , Yang Jinhui
Published: February 2023

Even in the context of smart mines, unsafe human acts are still an important cause of coal mine gas explosion accidents, but there are few models to analyze unsafe human acts in coal mine gas explosion accidents. This study tries to solve this problem through a risk assessment method of unsafe acts in coal mine gas explosion accidents based on Human Factor Analysis and Classification system (HFACS-GE) and Bayesian networks (BN). After verifying the reliability of HFACS-GE framework, a BN model of risk factors of unsafe acts was established with the Chi-square test and odds ratios analysis. After reasoning analysis, risk paths and key risk factors of unsafe acts were obtained, and preventive measures were granted. Based on the analysis of 100 coal mine gas explosion cases, the maximum probability of five kinds of unsafe acts of employees is 38%. Among the 22 risk factors, the mental state of employees has the greatest influence on the habitual violation of regulations, and the sensitivity value is 12.7%. This study can provide technical assistance for the risk management of unsafe acts in coal mine gas explosions.
A Feasible Framework for Maintenance Digitalization
Authors: Ahmed Umair , Carpitella Silvia , Certa Antonella , Izquierdo Joaquín
Published: February 2023

The entire industry is changing as a result of new developments in digital technology, and maintenance management is a crucial procedure that may take advantage of the opportunities brought about by industrial digitalization. To support digital innovation in maintenance management, this study intends to meet the cutting-edge necessity of addressing a transformation strategy in industrial contexts. Setting up a customized pathway with adequate methodologies, digitalization tools, and collaboration between the several stakeholders involved in the maintenance environment is the first step in this process. The results of a previous conference contribution, which revealed important digitalization variables in maintenance management, served as the foundation for the research approach herein suggested. We lead a thorough assessment of the literature to categorize the potential benefits and challenges in maintenance digitalization to be assessed in conjunction with the important digitalization aspects previously stated. As a starting point for maintenance management transformation, we offer a feasible framework for maintenance digitalization that businesses operating in a variety of industries can use. As industrial processes and machines have become more sophisticated and complex and as there is a growing desire for more secure, dependable, and safe systems, we see that this transition needs to be tailored to the specific application context.
FEM Simulation of Surface Micro-Groove Structure Fins Produced by Cryogenic-Temperature Extrusion Machining
Authors: Yin Xiaolong , Wang Zhilin , Guo Runyu , Wang Wan , Yu Hechun , Wang Hanbin
Published: February 2023

In the process of metal cutting, a large amount of chips that are difficult to reuse will be produced, resulting in resource waste. As a novel metal forming process, cryogenic-temperature extrusion machining (CT-EM) can directly process chips into usable fins with a surface micro-groove structure, which has the advantage of high efficiency, energy saving and flexibility. In this study, the effects of four parameters (compression ratio λ, rake angle of the tool α, friction coefficient μ and the constraining tool corner radius R) on the effective stress, temperature and formability of micro-groove fins produced by CT-EM and room-temperature extrusion machining (RT-EM) are investigated. The results show that the maximum effective stress and formability of CT-EM are larger than that of RT-EM, which indicates that CT-EM has greater advantages in the preparation of micro-groove fins. At a λ of 0.7, the formability of CT-EM is the best. Reducing the λ and α, or increasing the μ, can improve the forming effect of the fins. CT-EM can produce micro-groove fins with the best formability when λ = 0.7, α = 5°, μ = 0.75 and R = 0.1 mm.
Special Issue on “The Process and Modelling of Renewable Energy Sources”
Authors: Gabnai Zoltán , Pinter Gabor , Balogh Péter
Published: February 2023

The worldwide use of renewable energy sources has been growing significantly year by year, accompanied by continuous technological development [...]
Urban Feature Extraction within a Complex Urban Area with an Improved 3D-CNN Using Airborne Hyperspectral Data
Authors: Ma Xiaotong , Man Qixia , Yang Xinming , Dong Pinliang , Yang Zelong , Wu Jingru , Liu Chunhui
Published: February 2023

Airborne hyperspectral data has high spectral-spatial information. However, how to mine and use this information effectively is still a great challenge. Recently, a three-dimensional convolutional neural network (3D-CNN) provides a new effective way of hyperspectral classification. However, its capability of data mining in complex urban areas, especially in cloud shadow areas has not been validated. Therefore, a 3D-1D-CNN model was proposed for feature extraction in complex urban with hyperspectral images affected by cloud shadows. Firstly, spectral composition parameters, vegetation index, and texture characteristics were extracted from hyperspectral data. Secondly, the parameters were fused and segmented into many S × S × B patches which would be input into a 3D-CNN classifier for feature extraction in complex urban areas. Thirdly, Support Vector Machine (SVM), Random Forest (RF),1D-CNN, 3D-CNN, and 3D-2D-CNN classifiers were also carried out for comparison. Finally, a confusion matrix and Kappa coefficient were calculated for accuracy assessment. The overall accuracy of the proposed 3D-1D-CNN is 96.32%, which is 23.96%, 11.02%, 5.22%, and 0.42%, much higher than that of SVM, RF, 1D-CNN, or 3D-CNN, respectively. The results indicated that 3D-1D-CNN could mine spatial-spectral information from hyperspectral data effectively, especially that of grass and highway in cloud shadow areas with missing spectral information. In the future, 3D-1D-CNN could also be used for the extraction of urban green spaces.
UAV LiDAR and Hyperspectral Data Synergy for Tree Species Classification in the Maoershan Forest Farm Region
Authors: Wang Bin , Liu Jianyang , Li Jianing , Li Mingze
Published: February 2023

The accurate classification of single tree species in forests is important for assessing species diversity and estimating forest productivity. However, few studies have explored the influence of canopy morphological characteristics on the classification of tree species. Therefore, based on UAV LiDAR and hyperspectral data, in this study, we designed various classification schemes for the main tree species in the study area, i.e., birch, Manchurian ash, larch, Ulmus, and mongolica, in order to explore the effects of different data sources, classifiers, and canopy morphological features on the classification of a single tree species. The results showed that the classification accuracy of a single tree species using multisource remote sensing data was greater than that based on a single data source. The classification results of three different classifiers were compared, and the random forest and support vector machine classifiers exhibited similar classification accuracies, with overall accuracies above 78%. The BP neural network classifier had the lowest classification accuracy of 75.8%. The classification accuracy of all three classifiers for tree species was slightly improved when UAV LiDAR-extracted canopy morphological features were added to the classifier, indicating that the addition of canopy morphological features has a certain relevance for the classification of single tree species.
Potential of Sentinel-1 SAR to Assess Damage in Drought-Affected Temperate Deciduous Broadleaf Forests
Authors: Schellenberg Konstantin , Jagdhuber Thomas , Zehner Markus , Hese Sören , Urban Marcel , Urbazaev Mikhail , Hartmann Henrik , Schmullius Christiane , Dubois Clémence
Published: February 2023

Understanding forest decline under drought pressure is receiving research attention due to the increasing frequency of large-scale heat waves and massive tree mortality events. However, since assessing mortality on the ground is challenging and costly, this study explores the capability of satellite-borne Copernicus Sentinel-1 (S-1) C-band radar data for monitoring drought-induced tree canopy damage. As droughts cause water deficits in trees and eventually lead to early foliage loss, the S-1 radiometric signal and polarimetric indices are tested regarding their sensitivities to these effects, exemplified in a deciduous broadleaf forest. Due to the scattered nature of mortality in the study site, we employed a temporal-only time series filtering scheme that provides very high spatial resolution (10 m ×10 m) for measuring at the scale of single trees. Finally, the anomaly between heavily damaged and non-damaged tree canopy samples (n = 146 per class) was used to quantify the level of damage. With a maximum anomaly of −0.50 dB ± 1.38 for S-1 Span (VV+VH), a significant decline in hydrostructural scattering (moisture and geometry of scatterers as seen by SAR) was found in the second year after drought onset. By contrast, S-1 polarimetric indices (cross-ratio, RVI, Hα) showed limited capability in detecting drought effects. From our time series evaluation, we infer that damaged canopies exhibit both lower leaf-on and leaf-off backscatters compared to unaffected canopies. We further introduce an NDVI/Span hysteresis showing a lagged signal anomaly of Span behind NDVI (by ca. one year). This time-lagged correlation implies that SAR is able to add complementary information to optical remote sensing data for detecting drought damage due to its sensitivity to physiological and hydraulic tree canopy damage. Our study lays out the promising potential of SAR remote sensing information for drought impact assessment in deciduous broadleaf forests.
Validation of Nadir SWH and Its Variance Characteristics from CFOSAT in China’s Offshore Waters
Authors: Xu Jingwei , Wu Huanping , Xu Ying , Koldunov Nikolay V. , Zhang Xiuzhi , Kong Lisha , Xu Min , Fraedrich Klaus , Zhi Xiefei
Published: February 2023

The offshore waters of China are a typical monsoon−affected area where the significant wave height (SWH) is strongly influenced by the different seasonal mean flow in winter and summer. However, limited in situ validations of the SWH have been performed on the China–France Oceanography Satellite (CFOSAT) in these waters. This study focused on validating CFOSAT nadir SWH data with SWH data from in situ buoy observations for China’s offshore waters and the Haiyang−2B (HY−2B) satellite, from July 2019 to December 2021. The validation against the buoy data showed that the relative absolute error has a seasonal cycle, varying in a narrow range near 35%. The RMSE of the CFOSAT nadir SWH was 0.29 m when compared against in situ observations, and CFOSAT was found to be more likely to overestimate the SWH under calm sea conditions. The sea−surface winds play a key role in calm sea conditions. The spatial distributions of the CFOSAT and HY−2B seasonal SWHs were similar, with a two−year mean SWH−field correlation coefficient of 0.98. Moreover, the coherence between the two satellites’ SWH variance increased with SWH magnitude. Our study indicates that, in such typical monsoon−influenced waters, attention should be given to the influence of sea conditions on the accuracy of CFOSAT SWH, particularly in studies that combine data from multiple, long−duration space−based sensors.
Designing the Signal Quality Monitoring Algorithm Based on Chip Domain Observables for BDS B1C/B2a Signals under the Requirements of DFMC SBAS
Authors: Wang Xiang , Cui Xiaowei , Liu Gang , Lu Mingquan
Published: February 2023

To guarantee the integrity of a global navigation satellite system (GNSS) for safety-critical users, a satellite-based augmentation system (SBAS) makes use of the integrity monitoring architecture, of which the signal quality monitor (SQM) is an important component to address the potential risks caused by satellite-induced signal anomalies. Due to the introduction of dual-frequency multi-constellation (DFMC) techniques in 2025, the ranging uncertainty will be reduced by the elimination of first-order ionospheric delay, but the biases measured in each individual signal will be inflated by the ionosphere-free combinations. Moreover, multiple modulations of DFMC signals might introduce applicability uncertainty of a traditional SQM method that has been protecting GPS L1C/A signal only. Thus, higher requirements are put forward for future SQM methods in detection sensitivity and modulation independence. This paper first proposes a design methodology for the SQM algorithm for BDS B1C/B2a signals, which could be easily extended to the DF combinations of other GNSS core constellations. Then, by comparing the performances of SQM baseline algorithms based on traditional multi-correlator and emerging chip domain observables (CDOs), respectively, the superiority of CDO-based SQM is declared. Detailed design iterations are further discussed, including the algorithm practicalization with optimizing code-phase bin length and lowering sampling frequency, as well as the metric simplification, to promote the overall performance while preserving a lower implementation complexity. Ultimately, a CDO-based SQM algorithm for BDS B1C/B2a signals is reached, which would be considered as an effective candidate in new generation DFMC SBASs.
Mapping Vegetation Index-Derived Actual Evapotranspiration across Croplands Using the Google Earth Engine Platform
Authors: Abbasi Neda , Nouri Hamideh , Didan Kamel , Barreto-Muñoz Armando , Chavoshi Borujeni Sattar , Opp Christian , Nagler Pamela , Thenkabail Prasad S. , Siebert Stefan
Published: February 2023

Precise knowledge of crop water consumption is essential to better manage agricultural water use, particularly in regions where most countries struggle with increasing water and food insecurity. Approaches such as cloud computing and remote sensing (RS) have facilitated access, process, and visualization of big geospatial data to map and monitor crop water requirements. To find the most reliable Vegetation Index (VI)-based evapotranspiration (ETa) for croplands in drylands, we modeled and mapped ETa using empirical RS methods across the Zayandehrud river basin in Iran for two decades (2000–2019) on the Google Earth Engine platform using the Normalized Difference Vegetation Index (NDVI) and the Enhanced Vegetation Index 2 (EVI2). Developed ET-VI products in this study comprise three NDVI-based ETa (ET-NDVI*, ET-NDVI*scaled, and ET-NDVIKc) and an EVI2-based ETa (ET-EVI2). We (a) applied, for the first time, the ET-NDVI* method to croplands as a crop-independent index and then compared its performance with the ET-EVI2 and crop ET, and (b) assessed the ease and feasibility of the transferability of these methods to other regions. Comparing four ET-VI products showed that annual ET-EVI2 and ET-NDVI*scaled estimations were close. ET-NDVIKc consistently overestimated ETa. Our findings indicate that ET-EVI2 and ET-NDVIKc were easy to parametrize and adopt to other regions, while ET-NDVI* and ET-NDVI*scaled are site-dependent and sensitive to image acquisition time. ET-EVI2 performed robustly in arid and semi-arid regions making it a better tool. Future research should further develop and confirm these findings by characterizing the accuracy of VI-based ETa over croplands in drylands by comparing them with available ETa products and examining their performance using crop-specific comparisons.
Comparison of VLF Signal Responses to Solar Flares along Daytime and Nighttime Propagation Paths
Authors: Gu Xudong , Yi Juan , Wang Shiwei , Hu Zejun , Xu Wei , Ni Binbin , Li Bin , He Fang , Chen Xiangcai , Hu Hongqiao
Published: February 2023

Solar flares have a severe impact on the near-earth space environment, during which the VLF signals observed by the ground-based instrument exhibit abnormal changes. However, the similarity and differences of VLF signal responses to solar flares over daytime and nighttime propagation paths are still unclear. Previous magnetograph measurements suggest that solar flares can also influence the dark hemisphere by the induction currents caused by the change in the ionospheric electrical conductivity of the sunlit hemisphere. To examine these effects, we have analyzed the solar flare effects on VLF propagation along two paths that are suited along the north–south direction, but with a time difference of 12 h. From late March to late May in the year of 2022, a total of 32 flare events with clear VLF responses are selected in order to analyze the similarity and differences between daytime and nighttime propagation paths. Different from the previous magnetograph measurements, it is found that the solar flare effects can only be observed from daytime VLF propagation paths. Moreover, present results show that the amplitude and phase variation of the VLF signal increases almost linearly with the magnitude of solar flares, and the stronger the solar flare, the more obvious the influence on VLF signals. However, the two paths exhibit notably different sensitivity in terms of amplitude and phase variation to solar flare class. Future studies that aim at nowcasting solar flare events using ground-based VLF receivers need to take these effects into account. The goal is to better understand the effects of solar flares on the lower ionosphere, with a view toward improving the nowcasting capability of the VLF technique for solar flares.
Variational Regression for Multi-Target Energy Disaggregation
Authors: Virtsionis Gkalinikis Nikolaos , Nalmpantis Christoforos , Vrakas Dimitris
Published: February 2023

Non-intrusive load monitoring systems that are based on deep learning methods produce high-accuracy end use detection; however, they are mainly designed with the one vs. one strategy. This strategy dictates that one model is trained to disaggregate only one appliance, which is sub-optimal in production. Due to the high number of parameters and the different models, training and inference can be very costly. A promising solution to this problem is the design of an NILM system in which all the target appliances can be recognized by only one model. This paper suggests a novel multi-appliance power disaggregation model. The proposed architecture is a multi-target regression neural network consisting of two main parts. The first part is a variational encoder with convolutional layers, and the second part has multiple regression heads which share the encoder’s parameters. Considering the total consumption of an installation, the multi-regressor outputs the individual consumption of all the target appliances simultaneously. The experimental setup includes a comparative analysis against other multi- and single-target state-of-the-art models.
Reducing the Energy Consumption of sEMG-Based Gesture Recognition at the Edge Using Transformers and Dynamic Inference
Authors: Xie Chen , Burrello Alessio , Daghero Francesco , Benini Luca , Calimera Andrea , Macii Enrico , Poncino Massimo , Jahier Pagliari Daniele
Published: February 2023

Hand gesture recognition applications based on surface electromiographic (sEMG) signals can benefit from on-device execution to achieve faster and more predictable response times and higher energy efficiency. However, deploying state-of-the-art deep learning (DL) models for this task on memory-constrained and battery-operated edge devices, such as wearables, requires a careful optimization process, both at design time, with an appropriate tuning of the DL models’ architectures, and at execution time, where the execution of large and computationally complex models should be avoided unless strictly needed. In this work, we pursue both optimization targets, proposing a novel gesture recognition system that improves upon the state-of-the-art models both in terms of accuracy and efficiency. At the level of DL model architecture, we apply for the first time tiny transformer models (which we call bioformers) to sEMG-based gesture recognition. Through an extensive architecture exploration, we show that our most accurate bioformer achieves a higher classification accuracy on the popular Non-Invasive Adaptive hand Prosthetics Database 6 (Ninapro DB6) dataset compared to the state-of-the-art convolutional neural network (CNN) TEMPONet (+3.1%). When deployed on the RISC-V-based low-power system-on-chip (SoC) GAP8, bioformers that outperform TEMPONet in accuracy consume 7.8×–44.5× less energy per inference. At runtime, we propose a three-level dynamic inference approach that combines a shallow classifier, i.e., a random forest (RF) implementing a simple “rest detector” with two bioformers of different accuracy and complexity, which are sequentially applied to each new input, stopping the classification early for “easy” data. With this mechanism, we obtain a flexible inference system, capable of working in many different operating points in terms of accuracy and average energy consumption. On GAP8, we obtain a further 1.03×–1.35× energy reduction compared to static bioformers at iso-accuracy.
Moisture Detection in Tree Trunks in Semiarid Lands Using Low-Cost Non-Invasive Capacitive Sensors with Statistical Based Anomaly Detection Approach
Authors: Ali Ashraf , Ali Ahmad , Abaluof Hussein , Al-Sharu Wafaa N. , Saraereh Omar A. , Ware Andrew
Published: February 2023

This paper focuses on building a non-invasive, low-cost sensor that can be fitted over tree trunks growing in a semiarid land environment. It also proposes a new definition that characterizes tree trunks’ water retention capabilities mathematically. The designed sensor measures the variations in capacitance across its probes. It uses amplification and filter stages to smooth the readings, requires little power, and is operational over a 100 kHz frequency. The sensor sends data via a Long Range (LoRa) transceiver through a gateway to a processing unit. Field experiments showed that the system provides accurate readings of the moisture content. As the sensors are non-invasive, they can be fitted to branches and trunks of various sizes without altering the structure of the wood tissue. Results show that the moisture content in tree trunks increases exponentially with respect to the measured capacitance and reflects the distinct differences between different tree types. Data of known healthy trees and unhealthy trees and defective sensor readings have been collected and analysed statistically to show how anomalies in sensor reading baseds on eigenvectors and eigenvalues of the fitted curve coefficient matrix can be detected.
Advancements in Clay Materials for Trace Level Determination and Remediation of Phenols from Wastewater: A Review
Authors: Zango Zakariyya Uba , Rozaini Muhammad Nur’Hafiz , Bakar Noor Hana Hanif Abu , Zango Muttaqa Uba , Haruna Maje Alhaji , Dennis John Ojur , Alsadig Ahmed , Ibnaouf Khalid Hassan , Aldaghri Osamah A. , Wadi Ismael Abdalla
Published: February 2023

The wide spread of phenols and their toxicity in the environment pose a severe threat to the existence and sustainability of living organisms. Rapid detection of these pollutants in wastewaters has attracted the attention of researchers from various fields of environmental science and engineering. Discoveries regarding materials and method developments are deemed necessary for the effective detection and remediation of wastewater. Although various advanced materials such as organic and inorganic materials have been developed, secondary pollution due to material leaching has become a major concern. Therefore, a natural-based material is preferable. Clay is one of the potential natural-based sorbents for the detection and remediation of phenols. It has a high porosity and polarity, good mechanical strength, moisture resistance, chemical and thermal stability, and cation exchange capacity, which will benefit the detection and adsorptive removal of phenols. Several attempts have been made to improve the capabilities of natural clay as sorbent. This manuscript will discuss the potential of clays as sorbents for the remediation of phenols. The activation, modification, and application of clays have been discussed. The achievements, challenges, and concluding remarks were provided.
Three Quarks for Hypersexuality Research
Authors: Van Tuijl Piet , Verboon Peter , Van Lankveld Jacques J. D. M.
Published: February 2023

In some areas of sex research, we note room for methodological improvement of research practices. In particular, in the field of hypersexuality research, where societal norms have been influential, methodological improvement might advance goals of objectivity in research. We propose that hypersexuality research should: firstly, take into account relevant subpopulations; secondly, use Item Response Theory (IRT) to construct item banks for measurement instruments; and, thirdly, measure sexual desire and related important constructs where and how they play out—in daily life, changing from moment to moment. We show that comparing relevant subpopulations can lead to depathologizing normative, but highly frequent, sexual behavior. Using IRT can lead to more precise measurement instruments by assessment of characteristics of individual items. Measuring sexual desire as an inherently fluctuating process in everyday life, and as part of emotion regulation processes, can direct research towards relevant associations other research methods might miss. Bringing into practice our three proposals for improvement can procure a number of advantages. We illustrate these advantages mainly for the field of hypersexuality research, but our suggestions might also be beneficial for sex research in general.