bluuebunny/crossref_metadata_2025 huggingface dataset:
Extraction and Characterization of New Cellulosic Fiber from Catalpa bignonioides Fruits for Potential Use in Sustainable Products
Authors: Bozaci Ebru , Altınışık Tağaç Aylin
Published: January 2023

The purpose of this study was to investigate the extract of Catalpa bignonioides plants and characterize novel natural cellulosic fibers from the fruits as an alternative material for sustainable products. The Catalpa bignonioides tree contains pharmacologically active compounds and is found all over the world. The sustainable natural fibers were easily extracted in an environmentally friendly manner from the fruits of the plant and characterized in terms of their chemical, thermal, and physical properties. The Catalpa bignonioides fibers (CBF) were composed of cellulose (58.3%), hemicellulose (3.1%), and lignin (38.6%) and had a low density (0.713 g/cm3). Fourier transform (FT-IR) analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM) analyses were used to search for the chemical groups, crystalline structures, and surface morphology of the CBF fibers. The results suggest that CBF fibers are a suitable alternative for composite and textile applications.
Polyurethane Foam Residue Biodegradation through the Tenebrio molitor Digestive Tract: Microbial Communities and Enzymatic Activity
Authors: Orts Jose M. , Parrado Juan , Pascual Jose A. , Orts Angel , Cuartero Jessica , Tejada Manuel , Ros Margarita
Published: January 2023

Polyurethane (PU) is a widely used polymer with a highly complex recycling process due to its chemical structure. Eliminating polyurethane is limited to incineration or accumulation in landfills. Biodegradation by enzymes and microorganisms has been studied for decades as an effective method of biological decomposition. In this study, Tenebrio molitor larvae (T. molitor) were fed polyurethane foam. They degraded the polymer by 35% in 17 days, resulting in a 14% weight loss in the mealworms. Changes in the T. molitor gut bacterial community and diversity were observed, which may be due to the colonization of the species associated with PU degradation. The physical and structural biodegradation of the PU, as achieved by T. molitor, was observed and compared to the characteristics of the original PU (PU-virgin) using Fourier Transform InfraRed spectroscopy (FTIR), Thermal Gravimetric Analysis (TGA), and Scanning Electron Microphotography (SEM).
Functionalization of Conductive Polymers through Covalent Postmodification
Authors: Abel Silvestre Bongiovanni , Frontera Evelina , Acevedo Diego , Barbero Cesar A.
Published: January 2023

Organic chemical reactions have been used to functionalize preformed conducting polymers (CPs). The extensive work performed on polyaniline (PANI), polypyrrole (PPy), and polythiophene (PT) is described together with the more limited work on other CPs. Two approaches have been taken for the functionalization: (i) direct reactions on the CP chains and (ii) reaction with substituted CPs bearing reactive groups (e.g., ester). Electrophilic aromatic substitution, SEAr, is directly made on the non-conductive (reduced form) of the CPs. In PANI and PPy, the N-H can be electrophilically substituted. The nitrogen nucleophile could produce nucleophilic substitutions (SN) on alkyl or acyl groups. Another direct reaction is the nucleophilic conjugate addition on the oxidized form of the polymer (PANI, PPy or PT). In the case of PT, the main functionalization method was indirect, and the linking of functional groups via attachment to reactive groups was already present in the monomer. The same is the case for most other conducting polymers, such as poly(fluorene). The target properties which are improved by the functionalization of the different polymers is also discussed.
Fabrication of Bio-Based Film Comprising Metal Oxide Nanoparticles Loaded Chitosan for Wound Dressing Applications
Authors: Almaieli Latifah Mohammed Ali , Khalaf Mai M. , Gouda Mohamed , Elmushyakhi Abraham , Abou Taleb Manal F. , Abd El-Lateef Hany M.
Published: January 2023

In the current work, chitosan (CS)–metal oxide nanohybrid (MONH) composites are prepared via combining CS with MONH made of vanadium oxide (V2O5), ytterbium trioxide (Yb2O3), and graphene oxide (GO) to generate promising wound dressing materials using the film-casting method. The developed nanohybrid@CS was examined using techniques such as Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDX), and thermogravimetric analysis (TGA). For Yb2O3@CS, the surface morphology was shown to be a rough and porous surface with pores that ranged in size from 3.0 to 5.0 µm. For CS with Yb2O3, Yb2O3/V2O5@CS, and Yb2O3/V2O5/GO@CS, the contact angles were 72.5°, 68.2°, and 46.5°, respectively. When the nanohybrid@CS was in its hydrophilic phase, which is good for absorbing moisture and drugs, there was a notable decrease in angles that tended to rise. Additionally, the inclusion of MONH allowed the cell viability to be confirmed with an IC50 of 1997.2 g/mL and the cell growth to reach 111.3% at a concentration of 7.9 g/mL.
Low-Cost Zinc–Alginate-Based Hydrogel–Polymer Electrolytes for Dendrite-Free Zinc-Ion Batteries with High Performances and Prolonged Lifetimes
Authors: Zheng Zhuoyuan , Cao Haichuan , Shi Wenhui , She Chunling , Zhou Xianlong , Liu Lili , Zhu Yusong
Published: January 2023

Aqueous zinc-ion batteries (ZIBs) represent an attractive choice for energy storage. However, ZIBs suffer from dendrite growth and an irreversible consumption of Zn metal, leading to capacity degradation and a low lifetime. In this work, a zinc–alginate (ZA) hydrogel–polymer electrolyte (HGPE) with a non-porous structure was prepared via the solution-casting method and ion displacement reaction. The resulting ZA-based HGPE exhibits a high ionic conductivity (1.24 mS cm−1 at room temperature), excellent mechanical properties (28 MPa), good thermal and electrochemical stability, and an outstanding zinc ion transference number (0.59). The ZA-based HGPE with dense structure is proven to benefit the prevention of the uneven distribution of ion current and facilitates the reduction of excessive interfacial resistance within the battery. In addition, it greatly promotes the uniform deposition of zinc ions on the electrode, thereby inhibiting the growth of zinc dendrites. The corresponding zinc symmetric battery with ZA-based HGPE can be cycled stably for 800 h at a current density of 1 mA cm−2, demonstrating the stable and reversible zinc plating/stripping behaviors on the electrode surfaces. Furthermore, the quasi-solid-state ZIB with zinc, ZA-based HGPE, and Ca0.24V2O5 (CVO) as the anode, electrolyte, and cathode materials, respectively, show a stable cyclic performance for 600 cycles at a large current density of 3 C (1 C = 400 mA g−1), in which the capacity retention rate is 88.7%. This research provides a new strategy for promoting the application of the aqueous ZIBs with high performance and environmental benignity.
Measurement and Modeling of Semi-Batch Solution Radical Copolymerization of N-tert-Butyl Acrylamide with Methyl Acrylate in Ethanol/Water
Authors: Kaur Gagandeep , Agboluaje Maryam , Hutchinson Robin A.
Published: January 2023

The synthetic polymer industry is transitioning from the use of organic solvents to aqueous media in order to reduce environmental impact. However, with radical polymerization kinetics affected by hydrogen-bonding solvents, there is limited information regarding the use of water as a solvent for sparingly soluble monomers. Thus, in this paper, the radical polymerization of methyl acrylate (MA) and N-tert-butylacrylamide (t-BuAAm) is studied in water and ethanol (EtOH), as the copolymer product is of commercial interest. A series of semi-batch reactions are conducted under a range of operating conditions (i.e., reaction temperature, solvent-to-monomer ratio, and comonomer composition) to demonstrate that the copolymer can be successfully synthesized without significant drifts in product molar masses or composition. The experiments provide additional data to probe the influence of the solvent on the polymerization rate and copolymer properties, as the low monomer concentration maintained under starved-feed operation leads to a solvent-to-monomer ratio different from that in a batch system. A model that captures the influence of backbiting and solvent effects on rate, previously developed and tested against batch polymerizations, also provides an excellent description of semi-batch operation, validating the set of mechanisms and kinetic coefficients developed to represent the system.
Prediction of Peak Overpressure of Charge Enveloped by Polymer Matrix Composite: Theoretical Modeling and Experimental Verification
Authors: Li Jun-Bao , Li Wei-Bing , Wang Xiao-Ming , Yu Jia-Xin
Published: January 2023

This study aimed at elucidating some characteristics of the shock wave overpressure generated by a non-traditional layered charge comprising an inner high-energy explosive and an outer polymer matrix composite. Two models for predicting the peak overpressure (Δpm) of the charge were established, namely, a model based on the initial parameters of the blast wave, and a model considering the weakening of the explosion energy through the introduction of polymer matrix cladding. The overpressure of a typical layered charge was experimentally measured for model validation. It was found that the difference between the Δpm predicted by the two models and the experimental data is less than 15.12% and 14.17%, respectively. The model that was established based on the conservation of energy law, is in best agreement with the experimental data under different cladding/charge mass ratios (αm). The model that was based on the initial parameters of the blast wave obtained a low predicted value when αm was 0.4–0.8, which is attributed to the non-uniformity of the gas-solid mixture during the explosive dispersion stage.
Furanic Polymerization Causes the Change, Conservation and Recovery of Thermally-Treated Wood Hydrophobicity before and after Moist Conditions Exposure
Authors: Zhang Bengang , Petrissans Mathieu , Petrissans Anelie , Pizzi Antonio , Colin Baptiste
Published: January 2023

The Whilhelmy method of contact angle, wood thermal properties (TG/DTG), infrared spectroscopy, etc. was used to define the hydrophobicity of heat-treated beech and fir wood at increasing temperatures between 120 °C and 300 °C. By exposure to wet conditions during 1 week, the hydrophobic character obtained by the heat treatment remains constant heat-treated. Heat induced wood hydrophobation, was shown by CP MAS 13C NMR and MALDI ToF mass spectrometry to be mainly caused by furanic moieties produced from heat-induced hemicelluloses degradation. This is caused by the acid environment generated by the hydrolysis of the hemicelluloses acetyl groups. Furfural polymerizes to linear and branched oligomers and finally to water repellent, insoluble furanic resins. The water repellent, black colored, cross-linked polymerized furanic network is present throughout the heat-treated wood. Wood darkening as well as its water repellency due to increasing proportions of black colored furanic resins increase as a function of the increase with treating temperature, becoming particularly evident in the 200 to 300 °C treating temperature range.
Biodegradable Polymers in Triboelectric Nanogenerators
Authors: Mi Yajun , Lu Yin , Shi Yalin , Zhao Zequan , Wang Xueqing , Meng Jiajing , Cao Xia , Wang Ning
Published: January 2023

Triboelectric nanogenerators (TENGs) have attracted much attention because they not only efficiently harvest energy from the surrounding environment and living organisms but also serve as multifunctional sensors toward the detection of various chemical and physical stimuli. In particular, biodegradable TENG (BD-TENG) represents an emerging type of self-powered device that can be degraded, either in physiological environments as an implantable power source without the necessity of second surgery for device retrieval, or in the ambient environment to minimize associated environmental pollution. Such TENGs or TNEG-based self-powered devices can find important applications in many scenarios, such as tissue regeneration, drug release, pacemakers, etc. In this review, the recent progress of TENGs developed on the basis of biodegradable polymers is comprehensively summarized. Material strategies and fabrication schemes of biodegradable and self-powered devices are thoroughly introduced according to the classification of plant-degradable polymer, animal-degradable polymer, and synthetic degradable polymer. Finally, current problems, challenges, and potential opportunities for the future development of BD-TENGs are discussed. We hope this work may provide new insights for modulating the design of BD-TNEGs that can be beneficial for both environmental protection and healthcare.
PCL/Collagen/UA Composite Biomedical Dressing with Ordered Microfiberous Structure Fabricated by a 3D Near-Field Electrospinning Process
Authors: Mai Zhirui , Liu Qilong , Bian Yongshuang , Wang Peng , Fu Xuewei , Lin Dongsong , Kong Nianzi , Huang Yuqing , Zeng Zijun , Li Dingfan , Zheng Wenxu , Xia Yuanjun , Zhou Wuyi
Published: January 2023

In this work, a functionalized polycaprolactone (PCL) composite fiber combining calf-type I collagen (CO) and natural drug usnic acid (UA) was prepared, in which UA was used as an antibacterial agent. Through 3D near-field electrospinning, the mixed solution was prepared into PCL/CO/UA composite fibers (PCUCF), which has a well-defined perfect arrangement structure. The influence of electrospinning process parameters on fiber diameter was investigated, the optimal electrospinning parameters were determined, and the electric field simulation was conducted to verify the optimal parameters. The addition of 20% collagen made the composite fiber have good hydrophilicity and water absorption property. In the presence of PCUCF, 1% UA content significantly inhibited the growth rate of Gram-positive and negative bacteria in the plate culture. The AC-PCUCF (after crosslinking PCUCF) prepared by crosslinking collagen with genipin showed stronger mechanical properties, water absorption property, thermal stability, and drug release performance. Cell proliferation experiments showed that PCUCF and AC-PCUCF had no cytotoxicity and could promote cell proliferation and adhesion. The results show that PCL/CO/UA composite fiber has potential application prospects in biomedical dressing.
Lightweight and High Impact Toughness PP/PET/POE Composite Foams Fabricated by In Situ Nanofibrillation and Microcellular Injection Molding
Authors: Sun Junwei , Li Qian , Jiang Yufan , Jiang Jing , Yang Lian , Jia Caiyi , Chen Feng , Wang Xiaofeng
Published: January 2023

Polypropylene (PP) has become the most promising and candidate material for fabricating lightweight products. Microcellular injection molding (MIM) is a cost-effective technology for manufacturing porous plastic products. However, it is still challenging to fabricate high-performance PP microcellular components. Herein, we reported an efficient strategy to produce lightweight and high impact toughness foamed PP/polyethylene terephthalate (PET)/polyolefin-based elastomer (POE) components by combining in situ fibrillation (INF) and MIM technologies. First, the INF composite was prepared by integrating twin-screw compounding with melt spinning. SEM analysis showed PET nanofibrils with a diameter of 258 nm were achieved and distributed uniformly in the PP due to the POE’s inducing elaboration effect. Rheological and DSC analysis demonstrated PET nanofibrils pronouncedly improved PP’s viscoelasticity and crystal nucleation rate, respectively. Compared with PP foam, INF composite foam showed more stretched cells in the skin layer and refined spherical cells in the core layer. Due to the synergistic toughening effect of PET nanofibrils and POE elastic particles, the impact strength of INF composite foams was 295.3% higher than that of PP foam and 191.2% higher than that of melt-blended PP/PET foam. The results gathered in this study reveal potential applications for PP based INF composite foams in the manufacturing of lightweight automotive products with enhanced impact properties.
Palladium Nanoparticles on Chitosan-Coated Superparamagnetic Manganese Ferrite: A Biocompatible Heterogeneous Catalyst for Nitroarene Reduction and Allyl Carbamate Deprotection
Authors: Ebadi Mona , Asikin-Mijan Nurul , Md. Jamil Mohd Suzeren , Iqbal Anwar , Yousif Emad , Md Zain Ahmad Rifqi , Aziz Tengku Hasnan Tengku , Rahimi Yusop Muhammad
Published: January 2023

Although metallic nanocatalysts such as palladium nanoparticles (Pd NPs) are known to possess higher catalytic activity due to their large surface-to-volume ratio, however, in nanosize greatly reducing their activity due to aggregation. To overcome this challenge, superparamagnetic chitosan-coated manganese ferrite was successfully prepared and used as a support for the immobilization of palladium nanoparticles to overcome the above-mentioned challenge. The Pd-Chit@MnFe2O4 catalyst exhibited high catalytic activity in 4-nitrophenol and 4-nitroaniline reductions, with respective turnover frequencies of 357.1 min−1 and 571.4 min−1, respectively. The catalyst can also be recovered easily by magnetic separation after each reaction. Additionally, the Pd-Chit@MnFe2O4 catalyst performed well in the reductive deprotection of allyl carbamate. Coating the catalyst with chitosan reduced the Pd leaching and its cytotoxicity. Therefore, the catalytic activity of Pd-Chit@MnFe2O4 was proven to be unrestricted in biology conditions.
Porous Defective Bi/Bi3NbO7 Nanosheets for Efficient Photocatalytic NO Removal under Visible Light
Authors: Gao Ting , Lin Jingqi , Zhang Ke , Padervand Mohsen , Zhang Yifan , Zhang Wei , Shi Menglin , Wang Chuanyi
Published: January 2023

Since conventional techniques are ineffective for NO removal at low concentrations, photocatalysis has become attractive in this regard, recently. However, in practice, photocatalytic NO removal has drawbacks such as limited light absorption and the proclivity of producing toxic by-products. To address these issues, novel defective Bi/Bi3NbO7 structures with good porosity were fabricated by a solvothermal method and used for enhanced photocatalytic NO removal under visible light irradiation. The morphological and structural properties of the prepared materials were comprehensively analyzed. The optimal photocatalytic activity of pore-defective Bi/Bi3NbO7 for NO removal was 60.3%, when the molar ratios of urea and Bi(NO)3•5H2O to pristine Bi3NbO7 were 1:25 and 1:2, respectively, under the following operational conditions: NO concentration of 700 ppb, catalyst dosage of 50 mg and irradiation time of 14 min. The induced defects and the surface plasmon resonance (SPR) effect of Bi nanodots made remarkable contributions to improving the photocatalytic NO removal as well as inhibiting the toxic byproduct NO2. The photocatalytic NO removal pathway over the prepared photocatalysts was further mechanistically clarified taking advantage of EPR results and scavenging experiments. Considering the increased NO generation in the atmosphere, this work may provide novel insights for designing effective porous photocatalysts to treat gaseous toxic pollutants.
A Novel Two-Step Electrochemical Deposition Method for Sn-Pd Electrocatalyst Synthesis for a Potential Application in Direct Ethanol Fuel Cells
Authors: Lović Jelena D. , Eraković Pantović Sanja , Rakočević Lazar Z. , Ignjatović Nenad L. , Dimitrijević Silvana B. , Nikolić Nebojša D.
Published: January 2023

Sn-Pd electrocatalysts with a constant atomic ratio of 60 at.% Sn-40 at.% Pd suitable for potential application in direct ethanol fuel cells were synthesized using a novel two-step electrodeposition method. First, Sn was electrodeposited in various forms of dendrites, from spear-like and needle-like to individual fern-like dendrites to a network of intertwined fern-like dendrites, by varying the cathodic potential and then performing electrodeposition of Pd at a constant current density in the second step. A morphological and elemental analysis of Sn and Sn-Pd electrocatalysts was performed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) techniques, while the size of Sn dendrites was analyzed using the particle size distribution (PSD) method. Cyclic voltammetry (CV) and chronoamperometry were applied in order to study the catalytic behavior of Sn-Pd electrocatalysts in the ethanol oxidation reaction (EOR), while CO stripping was used to estimate the antipoisoning capability of the electrocatalysts. The Sn surface morphology of the sub-layer was highly correlated with the electrocatalytic activity of the examined Sn-Pd electrocatalysts. The high activity it presented towards the EOR showed the suitability of the Sn-Pd electrocatalyst constructed from individual fern-like Sn dendrites as a sub-layer. Compared to Pd alone, this Sn-Pd catalyst showed more than 3 times higher activity and improved EOR kinetics. This enhancement in the catalytic activity of the Sn-Pd electrocatalysts is attributed to both the morphological characteristics of Sn as a sub-layer and the bifunctional effect.
Study on Influencing Factors of Molecular Sieve Oxygen-Production System
Authors: Jiang Dongsheng , Li Hui
Published: January 2023

Molecular sieve oxygen-production technology, as a kind of air separation–oxygen production, is receiving more and more attention from every oxygen industry. The two-bed molecular sieve oxygen-production system studied in this paper can generally produce enriched gas with an oxygen concentration of more than 90%, which has the characteristics of strong applicability, high reliability, low cost and high efficiency. However, the gas oxygen concentration of a production system is greatly affected by internal and external factors such as the molecular sieve materials, atmospheric pressure and temperature environment. Through the continuous research of the molecular sieve oxygen-production system, it has been found that the oxygen cycle of the molecular sieve bed and the diameter of the washing and sizing hole also have an effect on the gas oxygen concentration of the production system. Therefore, in this paper, the two-bed molecular sieve oxygen-production device is the research object, with different oxygen-production cycles (including pressure time) and different washing and sizing hole diameter simulation experiments used to explore the molecular sieve oxygen-production system’s optimal oxygen-production cycle (including pressure time) and the rinsing sizing hole’s optimal aperture, to find the structure of the oxygen-production system and the control parameters for the oxygen-production efficiency of the law. The results show that the optimal oxygen-production cycle of the molecular sieve system is 8.0 s (pressure equalization time is 1.3 s), and the optimal diameter of the washing and sizing hole is 0.8 mm.
Effect of Carbonization Temperature of Rice Husk Char Preparation on SiC Structure and Composition of By-Products in SiC Synthesis with Magnesiothermic Reduction Method
Authors: Solihudin Solihudin , Haryono Haryono , Noviyanti Atiek Rostika , Umar Akrajas Ali
Published: January 2023

The structure of rice husk char is one of the factors that influence the morphology of SiC and the composition of by-products in the magnesiothermic reduction. This structure can be improved by carbonization. Therefore, this study aims to examine the effect of the carbonization temperature of rice husk char on the structure of SiC and identify the by-products formed by the magnesiothermic reduction. The rice husk char was made by carbonization at various temperatures of 700, 800, 900, and 1000 °C. They were converted to SiC by magnesiothermic reduction at 600 °C, washing with hydrochloric acid, calcination at 700 °C in an air atmosphere, and washing with a mixture of hydrofluoric acid and acetic acid. The products were characterized by FT-IR, XRD, and SEM-EDS. The results showed that creating SiC using the magnesiothermic method with carbonization at a temperature of 1000 °C produced a polytype 2H-SiC, and the by-products were MgO, Mg2SiO4, and Si. MgO was successfully separated in the washing step with a hydrochloric acid solution, while Mg2SiO4 was separated from SiC by washing using a mixture of hydrofluoric acid and acetic acid.
Algebraic Properties of Quantum Reference Frames: Does Time Fluctuate?
Authors: Bojowald Martin , Tsobanjan Artur
Published: January 2023

Quantum reference frames are expected to differ from classical reference frames because they have to implement typical quantum features such as fluctuations and correlations. Here, we show that fluctuations and correlations of reference variables, in particular of time, are restricted by their very nature of being used for reference. Mathematically, this property is implemented by imposing constraints on the system to make sure that reference variables are not physical degrees of freedom. These constraints not only relate physical degrees of freedom to reference variables in order to describe their behavior, they also restrict quantum fluctuations of reference variables and their correlations with system degrees of freedom. We introduce the notion of “almost-positive” states as a suitable mathematical method. An explicit application of their properties to examples of recent interest in quantum reference frames reveals previously unrecognized restrictions on possible frame–system interactions. While currently discussed clock models rely on assumptions that, as shown here, make them consistent as quantum reference frames, relaxing these assumptions will expose the models to new restrictions that appear to be rather strong. Almost-positive states also shed some light on a recent debate about the consistency of relational quantum mechanics.
Artificial Intelligence Methods in Safe Ship Control Based on Marine Environment Remote Sensing
Authors: Lisowski Józef
Published: January 2023

This article presents a combination of remote sensing, an artificial neural network, and game theory to synthesize a system for safe ship traffic management at sea. Serial data transmission from the ARPA anti-collision radar system are used to enable computer support of the navigator’s maneuvering decisions in situations where a large number of ships must be passed. The following methods were used to determine the safe and optimal trajectory of one’s own ship: static optimization, dynamic programming with neural constraints on the state of the control process in the form of domains of encountered ships generated by a three-layer artificial neural network, and positional and matrix games. Then, computer calculations for the safe trajectory of one’s own ship were carried out using the presented algorithms. The calculations were carried out for an actual navigational situation recorded on a r/v HORYZONT II research/training vessel radar screen under a real navigational situation in the Skagerrak–Kattegat Straits.
Satellite Imaging Techniques for Ground Movement Monitoring of a Deep Pipeline Trench Backfilled with Recycled Materials
Authors: Teodosio B. , Al-Taie A. , Yaghoubi E. , Wasantha P. L. P.
Published: January 2023

The damage to pipeline infrastructures caused by reactive soils has been a critical challenge for asset owners. Sustainable backfilling materials have recently gained interest to stabilize highly reactive zones as a pre-emptive approach towards sustainability. In this study, two adjacent sections of a sewer pipeline trench in Melbourne, Australia were backfilled with two blends of 100% recycled aggregates. The sites were monitored for ground deformations during October 2020–February 2022 (17 months) using surveying techniques. Interferometric synthetic aperture radar (InSAR) techniques and algorithms were also employed to estimate the ground movements of the sites and surrounding regions. The cross-validation of deformation results achieved from both techniques enabled an in-depth analysis of the effectiveness of the recycled aggregates to address reactive soil issues in urban developments. Observational deformation data and their spatiotemporal variation in the field were satisfactorily captured by the InSAR techniques: differential InSAR (DInSAR), persistent scatterer interferometry (PSI), and small baseline subset (SBAS). The SBAS estimations were found to be the closest to field measurements, primarily due to the analysis of zones without well-defined geometries. This study’s contribution to existing knowledge defines the spatiotemporal influence of sustainable backfill in areas with reactive soil through field data and satellite imaging. The relationship between InSAR techniques and actual field behavior of sustainable backfill can be a baseline for the growing construction that may be challenging to perform field monitoring due to resource constraints.
Response of Industrial Warm Drainage to Tide Revealed by Airborne and Sea Surface Observations
Authors: Zhang Donghui , Zhu Zhenchang , Zhang Lifu , Sun Xuejian , Zhang Zhijie , Zhang Wanchang , Li Xusheng , Zhu Qin
Published: January 2023

Maintaining the balance between power station operation and environmental carrying capacity in the process of cooling water discharge into coastal waters is an essential issue to be considered. Earth observations with airborne and sea surface sensors can efficiently estimate distribution characteristics of extensive sea surface temperature compared with traditional numerical and physical simulations. Data acquisition timing windows for those sensors are designed according to tidal data. The airborne thermal infrared data (Thermal Airborne Spectrographic Imager, TASI) is preprocessed by algorithms of atmospheric correction, geometric correction, strip brightness gradient removal, and noise reduction, and then the seawater temperature is inversed in association with sea surface synchronous temperature measurement data (Sea-Bird Electronics, SBE). Verification analyses suggested a satisfied accuracy of less than about 0.2 °C error between the predicted and the measured values in general. Multiple factors influence seawater temperature, i.e., meteorology, ocean current, runoff, water depth, seawater convection, and eddy current; tidal activity is not the only one. Environmental background temperature in different seasons is the governing factor affecting the diffusion effect of seawater temperature drainage according to analyses of the covariances and correlation coefficients of eight tidal states. The present study presents an efficient and quick seawater temperature monitoring technique owing to industrial warm drainage to sea by means of a complete set of seawater temperature inversion algorithms with multi-source thermal infrared hyperspectral data.
Characterizing the Changes in Permafrost Thickness across Tibetan Plateau
Authors: Zhao Yufeng , Yao Yingying , Jin Huijun , Cao Bin , Hu Yue , Ran Youhua , Zhang Yihang
Published: January 2023

Permafrost impacts the subsurface hydrology and determines the transport of buried biochemical substances. Current evaluations of permafrost mostly focus on the overlying active layer. However, the basic but missing information of permafrost thickness constrains the quantification of trends and effects of permafrost degradation on subsurface hydrological processes. Our study quantified the long-term variations in permafrost thickness on the Tibetan Plateau (TP) between 1851 and 2100 based on layered soil temperatures calculated from eight earth system models (ESMs) of Coupled Model Intercomparison Project (the sixth phase) and validated by field observations and previous permafrost pattern from remote sensing. The calculated permafrost distribution based on ESMs was validated by the pattern derived from the MODIS datasets and field survey. Our results show that permafrost thicker than 10 m covers approximately 0.97 million km2 of the total area of the TP, which represents an areal extent of over 36.49% of the whole TP. The mean permafrost thickness of the TP was 43.20 m between 1851 and 2014, and it would decrease at an average rate of 9.42, 14.99, 18.78, and 20.75 cm per year under scenarios SSP126, SSP245, SSP370, and SSP585 from 2015 to 2100, respectively. The permafrost thickness will decrease by over 50 cm per year in Qiangtang Basin under SSP585. Our study provides new insights for spatiotemporal changes in permafrost thickness and a basic dataset combined results of remote sensing, field measurements for further exploring relevant hydrological, geomorphic processes and biogeochemical cycles in the plateau cryospheric environment.
Hyperspectral Multispectral Image Fusion via Fast Matrix Truncated Singular Value Decomposition
Authors: Lin Hong , Long Jian , Peng Yuanxi , Zhou Tong
Published: January 2023

Recently, methods for obtaining a high spatial resolution hyperspectral image (HR-HSI) by fusing a low spatial resolution hyperspectral image (LR-HSI) and high spatial resolution multispectral image (HR-MSI) have become increasingly popular. However, most fusion methods require knowing the point spread function (PSF) or the spectral response function (SRF) in advance, which are uncertain and thus limit the practicability of these fusion methods. To solve this problem, we propose a fast fusion method based on the matrix truncated singular value decomposition (FTMSVD) without using the SRF, in which our first finding about the similarity between the HR-HSI and HR-MSI is utilized after matrix truncated singular value decomposition (TMSVD). We tested the FTMSVD method on two simulated data sets, Pavia University and CAVE, and a real data set wherein the remote sensing images are generated by two different spectral cameras, Sentinel 2 and Hyperion. The advantages of FTMSVD method are demonstrated by the experimental results for all data sets. Compared with the state-of-the-art non-blind methods, our proposed method can achieve more effective fusion results while reducing the fusing time to less than 1% of such methods; moreover, our proposed method can improve the PSNR value by up to 16 dB compared with the state-of-the-art blind methods.
The Use of an Airborne Laser Scanner for Rapid Identification of Invasive Tree Species Acer negundo in Riparian Forests
Authors: Mielczarek Dominik , Sikorski Piotr , Archiciński Piotr , Ciężkowski Wojciech , Zaniewska Ewa , Chormański Jarosław
Published: January 2023

Invasive species significantly impact ecosystems, which is fostered by global warming. Their removal generates high costs to the greenery managers; therefore, quick and accurate identification methods can allow action to be taken with minimal impact on ecosystems. Remote sensing techniques such as Airborne Laser Scanning (ALS) have been widely applied for this purpose. However, many species of invasive plants, such as Acer negundo L., penetrate the forests under the leaves and thus make recognition difficult. The strongly contaminated riverside forests in the Vistula valley were examined in the gradient of the center of Warsaw and beyond its limits within a Natura 2000 priority habitat (91E0), namely, alluvial and willow forests and poplars. This work aimed to assess the potentiality of a dual-wavelength ALS in identifying the stage of the A. negundo invasion. The research was carried out using over 500 test areas of 4 m diameter within the riparian forests, where the habitats did not show any significant traces of transformation. LiDAR bi-spectral data with a density of 6 points/m2 in both channels were acquired with a Riegl VQ-1560i-DW scanner. The implemented approach is based on crown parameters obtained from point cloud segmentation. The Adaptive Mean Shift 3D algorithm was used to separate individual crowns. This method allows for the delineation of individual dominant trees both in the canopy (horizontal segmentation) and undergrowth (vertical segmentation), taking into account the diversified structure of tree stands. The geometrical features and distribution characteristics of the GNDVI (Green Normalized Vegetation Index) were calculated for all crown segments. These features were found to be essential to distinguish A. negundo from other tree species. The classification was based on the sequential additive modeling algorithm using a multi-class loss function. Results with a high accuracy, exceeding 80%, allowed for identifying and localizing tree crowns belonging to the invasive species. With the presented method, we could determine dendrometric traits such as the age of the tree, its height, and the height of the covering leaves of the trees.
The Influence of Horizontal Thermal Advection on Near-Surface Energy Budget Closure over the Zoige Alpine Wetland, China
Authors: Lu Xuancheng , Wen Jun , Wang Dongxiao , Liu Wenhui , Yang Yue , Tian Hui , Wu Yueyue , Jiang Yuqin
Published: January 2023

Near-surface energy budget closure has been a trending topic in land surface processes research, especially on the underlying surfaces of heterogeneous wetlands. In this investigation, the horizontal thermal advection caused by thermal inhomogeneity over the alpine wetland is calculated based on the eddy covariance data observed at the Flower Lake observation field and WRF modelling data over the Zoige alpine wetland, China. The contribution of horizontal thermal advection to the near-surface energy closure is analysed. The results show that the mean horizontal heat advection of the Zoige wetland is 20.2 W·m−2, and the maximum value reached 55.0 W·m−2 in the summer of 2017. After introducing thermal advection into the near-surface energy balance equation, the near-surface energy closure ratio increased from 72.3% to 81.0%.
Evaluation and Comparison of Six High-Resolution Daily Precipitation Products in Mainland China
Authors: Wu Xiaoran , Zhao Na
Published: January 2023

Satellite-based and reanalysis precipitation products have experienced increasing popularity in agricultural, hydrological and meteorological applications, but their accuracy is still uncertain in different areas. In this study, six frequently used high-resolution daily precipitation products, including Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS), Global Satellite Mapping of Precipitation (GSMaP), Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (IMERG), Multi-Source Weighted-Ensemble Precipitation (MSWEP), Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Cloud Classification System-Climate Data Record (PERSIANN-CCS-CDR) and European Center for Medium-Range Weather Forecasts Reanalysis V5-Land (ERA5-Land), were comprehensively evaluated and compared in nine regions of mainland China between 2015 and 2019. The results reveal that, in general, GSMaP is the best precipitation product in different agricultural regions, especially based on the Pearson correlation coefficient (CC) and critical success index (CSI). ERA5-Land and MSWEP tend to have the highest probability of detection (POD) values, and MSWEP tends to have the smallest relative root mean squared error (RRMSE) values. GSMaP performs better at almost all precipitation levels and in most agricultural regions in each season, while MSWEP has the best performance for capturing the time series of mean daily precipitation. In addition, all precipitation products perform better in summer and worse in winter, and they are more accurate in the eastern region. The findings of this study will contribute to understanding the uncertainties of precipitation products, improving product quality and guiding product selection.
A Novel Hybrid LMD–ETS–TCN Approach for Predicting Landslide Displacement Based on GPS Time Series Analysis
Authors: Luo Wanqi , Dou Jie , Fu Yonghu , Wang Xiekang , He Yujian , Ma Hao , Wang Rui , Xing Ke
Published: January 2023

Landslide disasters cause serious property losses and casualties every year. Landslide displacement prediction is fundamental for mitigating landslide disasters. Several approaches have been used to predict landslide displacement, yet a more accurate and reliable displacement prediction still has a poor understanding of landslide early warning systems for landslide mitigation, due to limited data and mutational displacements. To boost the robustness and accuracy of landslide displacement prediction, this paper assembled a new hybrid model containing the local mean decomposition (LMD), innovations state space models for exponential smoothing (ETS), and the temporal convolutional network (TCN). The proposed model, which is based on over 10 years of long-term time series monitoring GPS data, was tested on the selected case—stepwise Baijiabao landslide in the Three Gorges Reservoir area of China (TGRA) was tested by the proposed model. The results presented that the LMD–ETS–TCN model has the best performance in comparison with other benchmark models. Compared with autoregressive integrated moving average (ARIMA), support vector regression (SVR), and long short-term memory neural network (LSTM), the accuracy was noticeably improved by an average of 40.9%, 46.2%, and 22.1%, respectively. The robustness and effectiveness of the presented approach are attested, and it has discernible improvements for landslide displacement prediction.
Influence of Scattered Sunlight for Wind Measurements with the O2(a1Δg) Dayglow
Authors: He Weiwei , Hu Xiangrui , Wang Houmao , Wang Daoqi , Li Juan , Li Faquan , Wu Kuijun
Published: January 2023

Observing the O2(a1Δg) dayglow with the limb-viewing DASH instrument enables remote sensing of neutral wind in near space. Many advantages are gained by using this new approach, but the influence factors on measurement accuracy have not been thoroughly investigated. This paper reports the quantitative evaluation of the wind error caused by scattered sunlight. The spectral concept of the O2(a1Δg) band and the measurement technique are briefly described. A comprehensive truth model simulation that is based on atmospheric limb radiance spectra and the instrument concept are used to obtain interferogram images. The algorithm, which uses these images to retrieve the interferogram containing information solely from the target altitude, is described. The self-absorption effect is taken into account in the unraveling of the line-of-sight integration. The influence of scattered sunlight on the limb-viewing weight and signal-to-noise ratio, two definitive factors for wind definitive factors, are also described. Representative wind precision profiles and their variation with surface albedo, aerosol loading, and cloud are presented. This indicates that the random error for Doppler wind is in the range of 2–3 m/s for the tangent height range from 45–80 km, and the wind precision under 45 km suffers significantly from scattered sunlight background.
A Decision-Tree Approach to Identifying Paddy Rice Lodging with Multiple Pieces of Polarization Information Derived from Sentinel-1
Authors: Dai Xuemei , Chen Shuisen , Jia Kai , Jiang Hao , Sun Yishan , Li Dan , Zheng Qiong , Huang Jianxi
Published: January 2023

Lodging is one of the typical abiotic adversities during paddy rice growth. In addition to affecting photosynthesis, it can seriously damage crop growth and development, such as reducing rice quality and hindering automated harvesting. It is, therefore, imperative to accurately and in good time acquire crop-lodging areas for yield prediction, agricultural insurance claims, and disaster-management decisions. However, the accuracy requirements for crop-lodging monitoring remain challenging due to complicated impact factors. Aiming at identifying paddy rice lodging on Shazai Island, Guangdong, China, caused by heavy rainfall and strong wind, a decision-tree model was constructed using multiple-parameter information from Sentinel-1 SAR images and the in situ lodging samples. The model innovatively combined the five backscattering coefficients with five polarization decomposition parameters and quantified the importance of each parameter feature. It was found that the decision-tree method coupled with polarization decomposition can be used to obtain an accurate distribution of paddy rice-lodging areas. The results showed that: (1) Radar parameters can capture the changes in lodged paddy rice. The radar parameters that best distinguish paddy rice lodging are VV, VV+VH, VH/VV, and Span. (2) Span is the parameter with the strongest feature importance, which shows the necessity of adding polarization parameters to the classification model. (3) The dual-polarized Sentinel-1 database classification model can effectively extract the area of lodging paddy rice with an overall accuracy of 84.38%, and a total area precision of 93.18%. These observations can guide the future use of SAR-based information for crop-lodging assessment and post-disaster management.
InTEn-LOAM: Intensity and Temporal Enhanced LiDAR Odometry and Mapping
Authors: Li Shuaixin , Tian Bin , Zhu Xiaozhou , Gui Jianjun , Yao Wen , Li Guangyun
Published: January 2023

Traditional LiDAR odometry (LO) systems mainly leverage geometric information obtained from the traversed surroundings to register lazer scans and estimate LiDAR ego-motion, while they may be unreliable in dynamic or degraded environments. This paper proposes InTEn-LOAM, a low-drift and robust LiDAR odometry and mapping method that fully exploits implicit information of lazer sweeps (i.e., geometric, intensity and temporal characteristics). The specific content of this work includes method innovation and experimental verification. With respect to method innovation, we propose the cylindrical-image-based feature extraction scheme, which makes use of the characteristic of uniform spatial distribution of lazer points to boost the adaptive extraction of various types of features, i.e., ground, beam, facade and reflector. We propose a novel intensity-based point registration algorithm and incorporate it into the LiDAR odometry, enabling the LO system to jointly estimate the LiDAR ego-motion using both geometric and intensity feature points. To eliminate the interference of dynamic objects, we propose a temporal-based dynamic object removal approach to filter them out in the resulting points map. Moreover, the local map is organized and downsampled using a temporal-related voxel grid filter to maintain the similarity between the current scan and the static local map. With respect to experimental verification, extensive tests are conducted on both simulated and real-world datasets. The results show that the proposed method achieves similar or better accuracy with respect to the state-of-the-art in normal driving scenarios and outperforms geometric-based LO in unstructured environments.