bluuebunny/crossref_metadata_2025 huggingface dataset:
Seed Germination of Invasive Phytolacca americana and Potentially Invasive P. acinosa
Authors: Strgulc Krajšek Simona , Kladnik Aleš , Skočir Sara , Bačič Martina
Published: February 2023

Phytolacca americana and P. acinosa are alien plant species in Europe. The former is considered invasive and more widespread. In order to develop effective and safe eradication and plant disposal methods, the present research focused on the seed germination of the two species. Fruits of different ripeness of both species were collected (fresh and dry seeds within and without pericarp), after which both the germination and maturation were tested. We also tested the continued maturing of fruits on cut plants and observed the development of fruits on whole plants with a cut taproot (in addition to when only the upper part of the stem with fruit racemes was cut off). In general, the seeds germinated from all stages of fruit ripeness, although the germination of dry seeds was better compared to fresh seeds. P. americana’s seeds germinated better and the fruit ripening on cut plants was also more successful compared to P. acinosa. These results could partly explain the invasive success of P. americana. According to our results, removing all fruiting plants from the eradication site is crucial regardless of the fruit development stage.
Investigation of Machine Learning Techniques for Disruption Prediction Using JET Data
Authors: Croonen Joost , Amaya Jorge , Lapenta Giovanni
Published: February 2023

Disruption prediction and mitigation is of key importance in the development of sustainable tokamak reactors. Machine learning has become a key tool in this endeavour. In this paper, multiple machine learning models are tested and compared. A focus has been placed on the analysis of a transition to dimensionless input quantities. The methods used in this paper are the support vector machine, two-tiered support vector machine, random forest, gradient-boosted trees and long-short term memory. The performance between different models is remarkably similar, with the support vector machine attaining a slightly better accuracy score. The similarity could indicate issues with the dataset, but further study is required to confirm this. Both the two-tiered model and long-short term memory performed below expectations. The former could be attributed to an implementation which did not allow error propagation between tiers. The latter could be attributed to high noise and low frequency of the input signals. Dimensionless models experienced an expected decrease in performance, caused by a loss of information in the conversion. However, random forest and gradient boosted trees experienced a significantly lower decrease, making them more suitable for dimensionless predictors. From the disruption detection times, it was concluded that several disruptions could be predicted at more than 600 ms in advance. A feature importance study using the random forest indicated the negative impact of high noise and missing data in the database, suggesting improvements in data preparation for future work and the potential reevaluation of some of the selected portable features due to poor performance.
Understanding the Role of Plasma Bullet Currents in Heating Skin to Mitigate Risks of Thermal Damage Caused by Low-Temperature Atmospheric-Pressure Plasma Jets
Authors: Hashimoto Shunya , Fukuhara Hideo , Szili Endre J. , Kawada Chiaki , Hong Sung-Ha , Matsumoto Yuta , Shirafuji Tatsuru , Tsuda Masayuki , Kurabayashi Atsushi , Furihata Mutsuo , Furuta Hiroshi , Hatta Akimitsu , Inoue Keiji , Oh Jun-Seok
Published: February 2023

Low-temperature atmospheric-pressure plasma jets are generally considered a safe medical technology with no significant long-term side effects in clinical studies reported to date. However, there are studies emerging that show plasma jets can cause significant side effects in the form of skin burns under certain conditions. Therefore, with a view of developing safer plasma treatment approaches, in this study we have set out to provide new insights into the cause of these skin burns and how to tailor plasma treatments to mitigate these effects. We discovered that joule heating by the plasma bullet currents is responsible for creating skin burns during helium plasma jet treatment of live mice. These burns can be mitigated by treating the mice at a further distance so that the visible plasma plume does not contact the skin. Under these treatment conditions we also show that the plasma jet treatment still retains its medically beneficial property of producing reactive oxygen species in vivo. Therefore, treatment distance is an important parameter for consideration when assessing the safety of medical plasma treatments.
Sorption Properties of PET Copolyesters and New Approach for Foaming with Filament Extrusion Additive Manufacturing
Authors: Sova Nadiya , Savchenko Bohdan , Beloshenko Victor , Slieptsov Aleksander , Vozniak Iurii
Published: February 2023

The mass transfer process of binary esters of acetic acid in polyethylene terephthalate (PET), polyethylene terephthalate with a high degree of glycol modification (PETG), and glycol-modified polycyclohexanedimethylene terephthalate (PCTG) was studied. It was found that the desorption rate of the complex ether at the equilibrium point is significantly lower than the sorption rate. The difference between these rates depends on the type of polyester and temperature and allows the accumulation of ester in the volume of the polyester. For example, the stable content of acetic ester in PETG at 20 °C is 5 wt.%. The remaining ester, which has the properties of a physical blowing agent, was used in the filament extrusion additive manufacturing (AM) process. By varying the technological parameters of the AM process, foams of PETG with densities ranging from 150 to 1000 g/cm3 were produced. Unlike conventional polyester foams, the resulting foams are not brittle.
Self-Healing Polymer Electrolytes for Next-Generation Lithium Batteries
Authors: Marinow Anja , Katcharava Zviadi , Binder Wolfgang H.
Published: February 2023

The integration of polymer materials with self-healing features into advanced lithium batteries is a promising and attractive approach to mitigate degradation and, thus, improve the performance and reliability of batteries. Polymeric materials with an ability to autonomously repair themselves after damage may compensate for the mechanical rupture of an electrolyte, prevent the cracking and pulverization of electrodes or stabilize a solid electrolyte interface (SEI), thus prolonging the cycling lifetime of a battery while simultaneously tackling financial and safety issues. This paper comprehensively reviews various categories of self-healing polymer materials for application as electrolytes and adaptive coatings for electrodes in lithium-ion (LIBs) and lithium metal batteries (LMBs). We discuss the opportunities and current challenges in the development of self-healable polymeric materials for lithium batteries in terms of their synthesis, characterization and underlying self-healing mechanism, as well as performance, validation and optimization.
Effects of NCO/OH Ratios on Bio-Based Polyurethane Film Properties Made from Acacia mangium Liquefied Wood
Authors: Palle Ismawati , Lodin Valeritta , Mohd Yunus Ag Ahmad , Lee Seng Hua , Md Tahir Paridah , Hori Naruhito , Antov Petar , Takemura Akio
Published: February 2023

The compatibility between isocyanate and polyol plays an important role in determining a polyurethane product’s performance. This study aims to evaluate the effect of varying the ratios between polymeric methylene diphenyl diisocyanate (pMDI) and Acacia mangium liquefied wood polyol on the polyurethane film properties. A. mangium wood sawdust was liquefied in polyethylene glycol/glycerol co-solvent with H2SO4 as a catalyst at 150 °C for 150 min. The A. mangium liquefied wood was mixed with pMDI with difference NCO/OH ratios to produce film through the casting method. The effects of the NCO/OH ratios on the molecular structure of the PU film were examined. The formation of urethane, which was located at 1730 cm−1, was confirmed via FTIR spectroscopy. The TGA and DMA results indicated that high NCO/OH ratios increased the degradation temperature and glass transition from 275 °C to 286 °C and 50 °C to 84 °C, respectively. The prolonged heat appeared to boost the crosslinking density of the A. mangium polyurethane films, which finally resulted in a low sol fraction. From the 2D-COS analysis, the hydrogen-bonded carbonyl (1710 cm−1) had the most significant intensity changes with the increasing NCO/OH ratios. The occurrence of the peak after 1730 cm−1 revealed that there was substantial formation of urethane hydrogen bonding between the hard (PMDI) and soft (polyol) segments as the NCO/OH ratios increased, which gave higher rigidity to the film.
Synthesis, Properties, and Biodegradability of Novel Sequence-Controlled Copolyesters Composed of Glycolic Acid, Dicarboxylic Acids, and C3 or C4 Diols
Authors: Nakayama Yuushou , Fukumoto Keitaro , Kusu Yuji , Tanaka Ryo , Shiono Takeshi , Kawasaki Norioki , Yamano Naoko , Nakayama Atsuyoshi
Published: February 2023

We have previously reported that sequence-controlled copolyesters such as poly((ethylene diglycolate) terephthalate) (poly(GEGT)) showed higher melting temperatures than those of the corresponding random copolymers and high biodegradability in seawater. In this study, to elucidate the effect of the diol component on their properties, a series of new sequence-controlled copolyesters composed of glycolic acid, 1,4-butanediol or 1,3-propanediol, and dicarboxylic acid units was studied. 1,4-Butylene diglycolate (GBG) and 1,3-trimethylene diglycolate (GPG) were prepared by the reactions of 1,4-dibromobutane or 1,3-dibromopropane with potassium glycolate, respectively. Polycondensation of GBG or GPG with various dicarboxylic acid chlorides produced a series of copolyesters. Terephthalic acid, 2,5-furandicarboxylic acid, and adipic acid were used as the dicarboxylic acid units. Among the copolyesters bearing terephthalate or 2,5-furandicarboxylate units, the melting temperatures (Tm) of the copolyesters containing 1,4-butanediol or 1,2-ethanediol units were substantially higher than those of the copolyester containing the 1,3-propanediol unit. Poly((1,4-butylene diglycolate) 2,5-furandicarboxylate) (poly(GBGF)) showed a Tm at 90 °C, while the corresponding random copolymer was reported to be amorphous. The glass-transition temperatures of the copolyesters decreased as the carbon number of the diol component increased. Poly(GBGF) was found to show higher biodegradability in seawater than that of poly(butylene 2,5-furandicarboxylate) (PBF). On the other hand, the hydrolysis of poly(GBGF) was suppressed in comparison with that of poly(glycolic acid). Thus, these sequence-controlled copolyesters have both improved biodegradability compared to PBF and lower hydrolyzability than PGA.
Superparamagnetic Multifunctionalized Chitosan Nanohybrids for Efficient Copper Adsorption: Comparative Performance, Stability, and Mechanism Insights
Authors: Al-Ghamdi Ahmed A. , Galhoum Ahmed A. , Alshahrie Ahmed , Al-Turki Yusuf A. , Al-Amri Amal M. , Wageh S.
Published: February 2023

To limit the dangers posed by Cu(II) pollution, chitosan-nanohybrid derivatives were developed for selective and rapid copper adsorption. A magnetic chitosan nanohybrid (r-MCS) was obtained via the co-precipitation nucleation of ferroferric oxide (Fe3O4) co-stabilized within chitosan, followed by further multifunctionalization with amine (diethylenetriamine) and amino acid moieties (alanine, cysteine, and serine types) to give the TA-type, A-type, C-type, and S-type, respectively. The physiochemical characteristics of the as-prepared adsorbents were thoroughly elucidated. The superparamagnetic Fe3O4 nanoparticles were mono-dispersed spherical shapes with typical sizes (~8.5–14.7 nm). The adsorption properties toward Cu(II) were compared, and the interaction behaviors were explained with XPS and FTIR analysis. The saturation adsorption capacities (in mmol.Cu.g−1) have the following order: TA-type (3.29) > C-type (1.92) > S-type (1.75) > A-type(1.70) > r-MCS (0.99) at optimal pH0 5.0. The adsorption was endothermic with fast kinetics (except TA-type was exothermic). Langmuir and pseudo-second-order equations fit well with the experimental data. The nanohybrids exhibit selective adsorption for Cu(II) from multicomponent solutions. These adsorbents show high durability over multiple cycles with desorption efficiency > 93% over six cycles using acidified thiourea. Ultimately, QSAR tools (quantitative structure-activity relationships) were employed to examine the relationship between essential metal properties and adsorbent sensitivities. Moreover, the adsorption process was described quantitatively, using a novel three-dimensional (3D) nonlinear mathematical model.
Influence of Mechanical Properties on the Piezoelectric Response of UV-Cured Composite Films Containing Different ZnO Morphologies
Authors: Duraccio Donatella , Capra Pier Paolo , Fioravanti Ambra , Malucelli Giulio
Published: February 2023

ZnO flower-like (ZFL) and needle (ZLN) structures were synthesized and embedded into UV-curable acrylic resin (EB), with the aim to study the effect of filler loading on the piezoelectric properties of the resulting composite films. The composites showed uniform dispersion of fillers within the polymer matrix. However, by increasing the filler amount, the number of aggregates increased, and ZnO fillers appeared not to be perfectly embedded in polymer film, indicating poor interaction with acrylic resin. The filler content increase caused an increase in glass transition temperature (Tg) and a decrease in storage modulus in the glassy state. In particular, compared with pure UV-cured EB (Tg = 50 °C), 10 wt.% ZFL and ZLN presented Tg values of 68 and 77 °C, respectively. The piezoelectric response generated by the polymer composites was good when measured at 19 Hz as a function of the acceleration; the RMS output voltages achieved at 5 g were 4.94 and 1.85 mV for the composite films containing ZFL and ZLN, respectively, at their maximum loading levels (i.e., 20 wt.%). Further, the RMS output voltage increase was not proportional to the filler loading; this finding was attributable to the decrease in the storage modulus of the composites at high ZnO loading rather than the dispersion of filler or the number of particles on the surface.
Prediction of The Mechanical Behavior of Polylactic Acid Parts with Shape Memory Effect Fabricated by FDM
Authors: Issabayeva Zhamila , Shishkovsky Igor
Published: February 2023

In this study, the mechanical as well as thermomechanical behaviors of shape memory PLA parts are presented. A total of 120 sets with five variable printing parameters were printed by the FDM method. The impact of the printing parameters on the tensile strength, viscoelastic performance, shape fixity, and recovery coefficients were studied. The results show that two printing parameters, the temperature of the extruder and the nozzle diameter, were more significant for the mechanical properties. The values of tensile strength varied from 32 MPa to 50 MPa. The use of a suitable Mooney–Rivlin model to describe the hyperelastic behavior of the material allowed us to gain a good fit for the experimental and simulation curves. For the first time, using this material and method of 3D printing, the thermomechanical analysis (TMA) allowed us to evaluate the thermal deformation of the sample and obtain values of the coefficient of thermal expansion (CTE) at different temperatures, directions, and running curves from 71.37 ppm/K to 276.53 ppm/K. Dynamic mechanical analysis (DMA) showed a similar characteristic of curves and similar values with a deviation of 1–2% despite different printing parameters. The glass transition temperature for all samples with different measurement curves ranged from 63–69 °C. A material crystallinity of 2.2%, considered by differential scanning calorimetry (DSC), confirmed its amorphous nature. From the SMP cycle test, we observed that the stronger the sample, the lower the fatigue from cycle to cycle observed when restoring the initial shape after deformation, while the fixation of the shape did not almost decrease with each SMP cycle and was close to 100%. Comprehensive study demonstrated a complex operational relationship between determined mechanical and thermomechanical properties, combining the characteristics of a thermoplastic material with the shape memory effect and FDM printing parameters.
Flame Retardancy and Mechanical Properties of Melt-Spun PA66 Fibers Prepared by End-Group Blocking Technology
Authors: Wu Yanpeng , Yang Tonghui , Cheng Yongchang , Huang Tao , Yu Bin , Wu Qilin , Zhu Meifang , Yu Hao
Published: February 2023

Preparing flame-retardant polyamide 66 (PA66) fibers through melt spinning remains one of the biggest challenges nowadays. In this work, dipentaerythritol (Di−PE), an eco-friendly flame retardant, was blended into PA66 to prepare PA66/Di−PE composites and fibers. It was confirmed that Di−PE could significantly improve the flame-retardant properties of PA66 by blocking the terminal carboxyl groups, which was conducive to the formation of a continuous and compact char layer and the reduced production of combustible gas. The combustion results of the composites showed that the limiting oxygen index (LOI) increased from 23.5% to 29.4%, and underwriter laboratories 94 (UL-94) passed the V-0 grade. The peak of heat release rate (PHRR), total heat release (THR), and total smoke production (TSP) decreased by 47.3%, 47.8%, and 44.8%, respectively, for the PA66/6 wt% Di−PE composite compared to those recorded for pure PA66. More importantly, the PA66/Di−PE composites possessed excellent spinnability. The prepared fibers still had good mechanical properties (tensile strength: 5.7 ± 0.2 cN/dtex), while maintaining good flame-retardant properties (LOI: 28.6%). This study provides an outstanding industrial production strategy for fabricating flame-retardant PA66 plastics and fibers.
Correlation Analysis and Prediction Model of Thermal Protection Performance of Aramid 1414 Fabric
Authors: Zhang Zhemin , Zhang Jinzhong , Ye Xiangyu , Ma Keai , Li Haihang
Published: February 2023

The thermal protection performance of fire suit is vital to the safety of firefighters. Using certain physical properties of fabrics to evaluate their thermal protection performance speeds up the process. This work aims to develop a TPP value prediction model that can be easily applied. Five properties of three types of Aramid 1414 made of the same material were tested, and the relationships between the physical properties of Aramid 1414 and its thermal protection performance (TPP value) were investigated. The results showed that the TPP value of the fabric had a positive correlation with grammage and air gap, and a negative correlation with the underfill factor. A stepwise regression analysis was used to solve the collinearity issue between the independent variables. Finally, a model for predicting TPP value by air gap and underfill factor was developed. The method adopted in this work reduced the number of independent variables in the prediction model, which is conducive to the application of the model.
Enhanced Sorption of Europium and Scandium Ions from Nitrate Solutions by Remotely Activated Ion Exchangers
Authors: Imangazy Aldan , Jumadilov Talkybek , Khimersen Khuangul , Bayshibekov Arman
Published: February 2023

The escalating demand for rare earth metals (REM) in situations of limited availability has spurred scientists to seek alternative sources of REM, such as industrial waste solutions. This paper investigates the potential for improving the sorption activity of readily available and inexpensive ion exchangers, specifically the interpolymer systems “Lewatit CNP LF and AV-17-8”, towards europium and scandium ions, in comparison to the unactivated ion exchangers. The sorption properties of the improved sorbents (interpolymer systems) were evaluated using conductometry, gravimetry, and atomic emission analysis. The results demonstrate that the “Lewatit CNP LF:AV-17-8” (5:1) interpolymer system exhibits a 25% increase in europium ion sorption compared to the raw Lewatit CNP LF (6:0), and a 57% increase in europium ion sorption compared to the raw AV-17-8 (0:6) ion exchanger after 48 h of the sorption process. In contrast, the “Lewatit CNP LF:AV-17-8” (2:4) interpolymer system exhibits a 310% increase in scandium ion sorption compared to the raw Lewatit CNP LF (6:0), and a 240% increase in scandium ion sorption compared to the raw AV-17-8 (0:6) after 48 h of interaction. The improvement in europium and scandium ion sorption levels by the interpolymer systems, compared to the raw ion exchangers, may be attributed to the high ionization degree resulting from the remote interaction effect of the polymer sorbents as the interpolymer system in aqueous media.
Wound Healing Effect of 20(S)-Protopanaxadiol of Ginseng Involves VEGF-ERK Pathways in HUVECs and Diabetic Mice
Authors: Park Do Hwi , Park Jun Yeon , Shin Myoung-Sook , Hwang Gwi Seo
Published: February 2023

Wound healing is the process of skin and soft tissue repair following an injury. Angiogenesis is an essential process in wound healing and plays an important role in tissue regeneration. Ginseng is mainly composed of saponins and protopanaxadiol-based ginsenosides, namely Rb1, Rb2, Rc, Re, Rg1, and Rf. 20(S)-protopanaxadiol (PPD) and 20(S)-protopanaxatriol (PPT) are aglycones of ginsenosides produced by metabolic processes and heat treatment. This study aimed to investigate the wound healing effects of active ingredients of ginseng, namely ginsenosides and aglycones, in various cellular and animal skin wound models. The angiogenic effects of ginsenosides were investigated in human umbilical vein endothelial cells (HUVECs). All experiments were conducted at increased intracellular glucose concentrations and the induction of angiogenesis through tube formation was evaluated. Among the ginsenosides and aglycones used in this study, PPD showed the strongest wound-healing activity. Cell scratch experiments confirmed that PPD increased intracellular proliferation and cell migration at high glucose concentrations, and western blotting of HUVECs showed that phosphorylated ERK, Akt, and p38 were regulated. We observed accelerated wound healing with PPD treatment in STZ-treated mice. Overall, the findings suggested that PPD could possibly help improve skin wound healing in patients with diabetes, although further research is recommended.
Novel Iterative Feedback Tuning Method Based on Overshoot and Settling Time with Fuzzy Logic
Authors: Gonzalez-Villagomez Jacob , Rodriguez-Donate Carlos , Lopez-Ramirez Misael , Mata-Chavez Ruth I. , Palillero-Sandoval Omar
Published: February 2023

Proportional–integral–derivative controllers are applied for solving a wide range of problems in industrial processes. They are preferred over computational techniques because of their implementation simplicity, low cost, and robustness against noise. In this paper, a novel iterative feedback tuning method is proposed using fuzzy logic, where the design parameters proposed by the user are the desired plant overshoot and settling time. In contrast to classical methods, the proposed technique does not require a precise and complex mathematical model for tuning the proportional–integral–derivative controllers through the plant, nor does it need an expert who knows the precise behavior of the system as in methods based on computational techniques. Furthermore, unlike iterative feedback tuning methods that use cost functions and require several experiments to perform the iterations, this proposal uses fuzzy logic to update the controller parameters, which facilitates its implementation in programmable hardware. The proposed method can be easily implemented in software considering three main stages: pre-processing, fuzzy logic system, and post-processing. The simulation and experimental results demonstrate the effectiveness of the proposed method for proportional–integral–derivative controller tuning; moreover, according to the performed comparison, the proposed method provides a trade-off between performance and robustness in comparison with other tuning techniques.
Substituent Effects in Kaolinite Flotation Using Dodecylamine: Experiment and DFT Study
Authors: Shen Liang , Gong Jiabao , Liu Yifang , Qiao Erle
Published: February 2023

The molecular structure of cationic surfactants is closely related to their flotation performance. In this paper, three cationic surfactants with different head group structures were selected as collectors of kaolinite, and the substituent effects were studied by the DFT method. The DFT calculation results showed that increasing the number of substituents in the dodecylamine head group can significantly increase its surface and head group charge. Dodecylamine has the lowest LUMO orbital energy, so dodecylamine has the strongest electron attraction ability and the strongest interaction with kaolinite. Electron density differential showed that there was an area of electron aggregation between the collector and the surface of the kaolinite. The interaction energy of DDA on kaolinite surfaces was greater than that of the other two collectors, indicating that the adsorption of DDA on the surface of kaolinite was more stable. Flotation results showed that higher a kaolinite yield was obtained in the presence of dodecyl dihydroxyethyl methyl ammonium chloride. The calculated results of the solvent-accessible surfaces, the head group charge, and the number of bonds between the collector and the kaolinite show good consistency with the actual flotation results of the three collectors, which can be used as a screening index for kaolinite flotation collectors.
Has James Sterba Established a Logical Argument from Evil or Just a Very Good Evidential One?
Authors: Carrier Richard
Published: February 2023

James Sterba’s new treatise advancing a logical argument from evil against the existence of God fails in one respect and succeeds in another. As with all claimants to having found such a thing before him, Sterba fails in properly achieving a logical argument from evil. But he succeeds in producing one of the most undefeatable evidential arguments from evil yet published. Elegantly dispatching all the common defenses, Sterba shows that there is no way to avoid the force of his argument against the existence of God without adopting extraordinarily improbable hypotheses that theists can’t even intelligibly articulate.
An Explainable Dynamic Prediction Method for Ionospheric foF2 Based on Machine Learning
Authors: Wang Jian , Yu Qiao , Shi Yafei , Liu Yiran , Yang Cheng
Published: February 2023

To further improve the prediction accuracy of the critical frequency of the ionospheric F2 layer (foF2), we use the machine learning method (ML) to establish an explanatory dynamic model to predict foF2. Firstly, according to the ML modeling process, the three elements of establishing a prediction model of foF2 and four problems to be solved are determined, and the idea and concrete steps of model building are determined. Then the data collection is explained in detail, and according to the modeling process, foF2 dynamic change mapping and its parameters are determined in turn. Finally, the established model is compared with the International Reference Ionospheric model (IRI-2016) and the Asian Regional foF2 Model (ARFM) to verify the validity and reliability. The results show that compared with the IRI-URSI, IRI-CCIR, and ARFM models, the statistical average error of the established model decreased by 0.316 MHz, 0.132 MHz, and 0.007 MHz, respectively. Further, the statistical average relative root-mean-square error decreased by 9.62%, 4.05%, and 0.15%, respectively.
A Reconstructed Method of Acoustic Logging Data and Its Application in Seismic Lithological Inversion for Uranium Reservoir
Authors: Sun Zhangqing , Yang Songlin , Zhang Fengjiao , Lu Jipu , Wang Ruihu , Ou Xiyang , Lei Anguai , Han Fuxing , Cen Wenpan , Wei Da , Liu Mingchen
Published: February 2023

As a sedimentary mineral, most sandstone type uranium deposits are formed in petroliferous basins. Therefore, we can fully tap the residual economic value of historical logging and 3D seismic data measured for oil and gas to search for sandstone type uranium deposits. However, a large amount of acoustic logging data are missing in the target stratum of the uranium reservoir in that it is not the main stratum of oil and gas. A reconstructed method of acoustic logging data based on clustering analysis and with the low-frequency compensation of deterministic inversion is proposed to solve this problem. Secondly, we can use these logging data with seismic data to obtain the 3D inversion data volume representing the sand body of the uranium reservoir based on seismic lithological inversion. Then, we can also delimit the 3D spatial range of sandstone type uranium deposits in petroliferous basins based on the calibration of uranium anomaly and sub-body detection. Finally, a 3D field data example is given to test and analyze the effectiveness of the above research schemes.
Relationship between Crustal Deformation and Thermal Anomalies in the 2022 Ninglang Ms 5.5 Earthquake in China: Clues from InSAR and RST
Authors: Lai Zhibin , Chao Jiangqin , Zhao Zhifang , Wen Mingchun , Yang Haiying , Chai Wang , Yao Yuan , Zhao Xin , Chen Qi , Liu Jianyu
Published: February 2023

On 2 January 2022, an earthquake of Ms 5.5 occurred in Ninglang County, Lijiang City, the earthquake-prone area of northwestern Yunnan. Whether this earthquake caused significant deformation and thermal anomalies and whether there is a relationship between them needs further investigation. Currently, multi-source remote sensing technology has become a powerful tool for long-time-series monitoring of earthquakes and active ruptures which mainly focuses on single crustal deformation and thermal anomaly. This study aims to reveal the crustal deformation and thermal anomaly characteristics of the Ninglang earthquake by using both Interferometric Synthetic Aperture Radar (InSAR) and Robust Satellite Techniques (RST). First, Sentinel-1A satellite SAR data were selected to obtain the coseismic deformation field based on Differential InSAR (D-InSAR), and the Small Baseline Set InSAR (SBAS-InSAR) technique was exploited to invert the pre- and post-earthquake displacement sequences. Then, RST was used to extract the thermal anomalies before and after the earthquake by using Moderate Resolution Imaging Spectroradiometer Land Surface Temperature (MODIS LST). The results indicate that the seismic crustal deformation is dominated by subsidence, with 23 thermal anomalies before and after the earthquake. It is speculated that the Yongning Fault in the deformation area is the main seismogenic fault of the Ninglang earthquake, which is dominated by positive fault dip-slip motion. Meanwhile, the seismic fault system composed of NE- and NW-oriented faults is an important factor in the formation of thermal anomalies, which are accompanied by changes in stress at different stages before and after the earthquake. Moreover, the crustal deformation and seismic thermal anomalies are correlated in time and space, and the active rupture activities in the region produce deformation accompanied by changes in thermal radiation. This study provides clues from remote sensing observations for analyzing the Ninglang earthquake and provides a reference for the joint application of InSAR and RST for earthquake monitoring.
Refined Estimation of Potential GDP Exposure in Low-Elevation Coastal Zones (LECZ) of China Based on Multi-Source Data and Random Forest
Authors: Li Feixiang , Mao Liwei , Chen Qian , Yang Xuchao
Published: February 2023

With climate change and rising sea levels, the residents and assets in low-elevation coastal zones (LECZ) are at increasing risk. The application of high-resolution gridded population datasets in recent years has highlighted the threats faced by people living in LECZ. However, the potential exposure of gross domestic product (GDP) within LECZ remains unknown, due to the absence of refined GDP datasets and corresponding analyzes for coastal regions. The climate-related risks faced by LECZ may still be underestimated. In this study, we estimated the potential exposure of GDP in the LECZ across China by overlying DEM with new gridded GDP datasets generated by random forest models. The results show that 24.02% and 22.7% of China’s total GDP were located in the LECZ in 2010 and 2019, respectively, while the area of the LECZ only accounted for 1.91% of China’s territory. Significant variability appears in the spatial-temporal pattern and the volume of GDP across sectors, which impedes disaster prevention and mitigation efforts within administrative regions. Interannual comparisons reveal a rapid increase in GDP within the LECZ, but a decline in its share of the country. Policy reasons may have driven the slow shift of China’s economy to regions far from the LECZ.
Hazard Potential in Southern Pakistan: A Study on the Subsidence and Neotectonics of Karachi and Surrounding Areas
Authors: Tirmizi Osman , Khan Shuhab D. , Mirzaee Sara , Fattahi Heresh
Published: February 2023

Coastal communities in deltaic regions worldwide are subject to subsidence through a combination of natural and anthropogenic processes. The city of Karachi in southern Pakistan is situated along the diffuse western boundary of the tectonically active Indian Plate, making it more susceptible to natural subsidence processes from plate motion-related deformational events such as earthquakes and faulting. Karachi has a dense population of over 16 million people, and determining the rate of subsidence and extent of neotectonic activity is crucial for mitigating seismic hazards. Excessive abstraction of groundwater and extensive groundwater use in irrigation are some of the anthropogenic contributions to subsidence in the area. A combination of the lack of historical data and few previous studies of the area make it difficult to determine the rate and extent of deformation in this region. We present an analysis of subsidence and neotectonic activity in Karachi and its surrounding areas using Interferometric Synthetic Aperture Radar (InSAR) timeseries techniques. The InSAR results for satellite LOS velocity change in both ascending and descending Sentinel-1 tracks indicate subsidence in key residential and industrial areas. Further decomposition into two dimensions (east–west and vertical) quantifies subsidence in these areas up to 1.7 cm per year. Furthermore, InSAR data suggest the presence of an active north–east dipping listric normal fault in North Karachi that is confirmed in the shallow subsurface by a 2D seismic line. Subsidence is known to cause the reactivation of faults, which increases the risk of damage to infrastructure.
Multi-Modal Multi-Stage Underwater Side-Scan Sonar Target Recognition Based on Synthetic Images
Authors: Wang Jian , Li Haisen , Huo Guanying , Li Chao , Wei Yuhang
Published: February 2023

Due to the small sample size of underwater acoustic data and the strong noise interference caused by seabed reverberation, recognizing underwater targets in Side-Scan Sonar (SSS) images is challenging. Using a transfer-learning-based recognition method to train the backbone network on a large optical dataset (ImageNet) and fine-tuning the head network with a small SSS image dataset can improve the classification of sonar images. However, optical and sonar images have different statistical characteristics, directly affecting transfer-learning-based target recognition. In order to improve the accuracy of underwater sonar image classification, a style transformation method between optical and SSS images is proposed in this study. In the proposed method, objects with the SSS style were synthesized through content image feature extraction and image style transfer to reduce the variability of different data sources. A staged optimization strategy using multi-modal data effectively captures the anti-noise features of sonar images, providing a new learning method for transfer learning. The results of the classification experiment showed that the approach is more stable when using synthetic data and other multi-modal datasets, with an overall accuracy of 100%.
Ecological Risk Assessment and Prediction Based on Scale Optimization—A Case Study of Nanning, a Landscape Garden City in China
Authors: Chen Jianjun , Yang Yanping , Feng Zihao , Huang Renjie , Zhou Guoqing , You Haotian , Han Xiaowen
Published: February 2023

Analysis and prediction of urban ecological risk are crucial means for resolving the dichotomy between ecological preservation and economic development, thereby enhancing regional ecological security and fostering sustainable development. This study uses Nanning, a Chinese landscape garden city, as an example. Based on spatial granularity and extent perspectives, using 30 m land use data, the optimal scale for an ecological risk assessment (ERA) and prediction is confirmed. This study also explores the patterns of spatial and temporal changes in ecological risk in Nanning on the optimal scale. At the same time, the Patch-generating Land Use Simulation model is used to predict Nanning’s ecological risk in 2036 under two scenarios and to propose ecological conservation recommendations in light of the study results. The study results show that: a spatial granularity of 120 m and a spatial extent of 7 km are the best scales for ERA and prediction in Nanning. Although the spatial distribution of ecological risk levels is obviously different, the overall ecological risk is relatively low, and under the scenario of ecological protection in 2036, the area of high ecological risk in Nanning is small. The results can provide theoretical support for ERA and the prediction of landscape cities and ecological civilization construction.
A Review of Radio Observations of the Giant Planets: Probing the Composition, Structure, and Dynamics of Their Deep Atmospheres
Authors: de Pater Imke , Molter Edward M. , Moeckel Chris M.
Published: February 2023

Radio observations of the atmospheres of the giant planets Jupiter, Saturn, Uranus, and Neptune have provided invaluable constraints on atmospheric dynamics, physics/chemistry, and planet formation theories over the past 70 years. We provide a brief history of these observations, with a focus on recent and state-of-the-art studies. The global circulation patterns, as derived from these data, in combination with observations at UV/visible/near-IR wavelengths and in the thermal infrared, suggest a vertically-stacked pattern of circulation cells in the troposphere, with the top cell similar to the classical picture, overlying cells with the opposite circulation. Data on the planets’ bulk compositions are used to support or disfavor different planet formation scenarios. While heavy element enrichment in the planets favors the core accretion model, we discuss how the observed relative enrichments in volatile species constrain models of the outer proto-planetary disk and ice giant accretion. Radio observations of planets will remain invaluable in the next decades, and we close with some comments on the scientific gain promised by proposed and under-construction radio telescopes.
Repeatability and Temporal Consistency of Lower Limb Biomechanical Variables Expressing Interlimb Coordination during the Double-Support Phase in People with and without Stroke Sequelae
Authors: Couto Ana , Vaz Mário , Pinho Liliana , Félix José , Moreira Juliana , Pinho Francisco , Mesquita Inês , Montes António , Crasto Carlos , Sousa Andreia
Published: February 2023

Reliable biomechanical methods to assess interlimb coordination during the double-support phase in post-stroke subjects are needed for assessing movement dysfunction and related variability. The data obtained could provide a significant contribution for designing rehabilitation programs and for their monitorisation. The present study aimed to determine the minimum number of gait cycles needed to obtain adequate values of repeatability and temporal consistency of lower limb kinematic, kinetic, and electromyographic parameters during the double support of walking in people with and without stroke sequelae. Eleven post-stroke and thirteen healthy participants performed 20 gait trials at self-selected speed in two separate moments with an interval between 72 h and 7 days. The joint position, the external mechanical work on the centre of mass, and the surface electromyographic activity of the tibialis anterior, soleus, gastrocnemius medialis, rectus femoris, vastus medialis, biceps femoris, and gluteus maximus muscles were extracted for analysis. Both the contralesional and ipsilesional and dominant and non-dominant limbs of participants with and without stroke sequelae, respectively, were evaluated either in trailing or leading positions. The intraclass correlation coefficient was used for assessing intra-session and inter-session consistency analysis. For most of the kinematic and the kinetic variables studied in each session, two to three trials were required for both groups, limbs, and positions. The electromyographic variables presented higher variability, requiring, therefore, a number of trials ranging from 2 to >10. Globally, the number of trials required inter-session ranged from 1 to >10 for kinematic, from 1 to 9 for kinetic, and 1 to >10 for electromyographic variables. Thus, for the double support analysis, three gait trials were required in order to assess the kinematic and kinetic variables in cross-sectional studies, while for longitudinal studies, a higher number of trials (>10) were required for kinematic, kinetic, and electromyographic variables.
Different Ventricular Fibrillation Types in Low-Dimensional Latent Spaces
Authors: Bernal Oñate Carlos Paúl , Melgarejo Meseguer Francisco-Manuel , Carrera Enrique V. , Sánchez Muñoz Juan José , García Alberola Arcadi , Rojo Álvarez José Luis
Published: February 2023

The causes of ventricular fibrillation (VF) are not yet elucidated, and it has been proposed that different mechanisms might exist. Moreover, conventional analysis methods do not seem to provide time or frequency domain features that allow for recognition of different VF patterns in electrode-recorded biopotentials. The present work aims to determine whether low-dimensional latent spaces could exhibit discriminative features for different mechanisms or conditions during VF episodes. For this purpose, manifold learning using autoencoder neural networks was analyzed based on surface ECG recordings. The recordings covered the onset of the VF episode as well as the next 6 min, and comprised an experimental database based on an animal model with five situations, including control, drug intervention (amiodarone, diltiazem, and flecainide), and autonomic nervous system blockade. The results show that latent spaces from unsupervised and supervised learning schemes yielded moderate though quite noticeable separability among the different types of VF according to their type or intervention. In particular, unsupervised schemes reached a multi-class classification accuracy of 66%, while supervised schemes improved the separability of the generated latent spaces, providing a classification accuracy of up to 74%. Thus, we conclude that manifold learning schemes can provide a valuable tool for studying different types of VF while working in low-dimensional latent spaces, as the machine-learning generated features exhibit separability among different VF types. This study confirms that latent variables are better VF descriptors than conventional time or domain features, making this technique useful in current VF research on elucidation of the underlying VF mechanisms.
A 2D-Lidar-Equipped Unmanned Robot-Based Approach for Indoor Human Activity Detection
Authors: Bouazizi Mondher , Lorite Mora Alejandro , Ohtsuki Tomoaki
Published: February 2023

Monitoring the activities of elderly people living alone is of great importance since it allows for the detection of when hazardous events such as falling occur. In this context, the use of 2D light detection and ranging (LIDAR) has been explored, among others, as a way to identify such events. Typically, a 2D LIDAR is placed near the ground and collects measurements continuously, and a computational device classifies these measurements. However, in a realistic environment with home furniture, it is hard for such a device to operate as it requires a direct line of sight (LOS) with its target. Furniture will block the infrared (IR) rays from reaching the monitored person thus limiting the effectiveness of such sensors. Nonetheless, due to their fixed location, if a fall is not detected when it happens, it cannot be detected afterwards. In this context, cleaning robots present a much better alternative given their autonomy. In this paper, we propose to use a 2D LIDAR mounted on top of a cleaning robot. Through continuous movement, the robot is able to collect distance information continuously. Despite having the same drawback, by roaming in the room, the robot can identify if a person is laying on the ground after falling, even after a certain period from the fall event. To achieve such a goal, the measurements captured by the moving LIDAR are transformed, interpolated, and compared to a reference state of the surroundings. A convolutional long short-term memory (LSTM) neural network is trained to classify the processed measurements and identify if a fall event occurs or has occurred. Through simulations, we show that such a system can achieve an accuracy equal to 81.2% in fall detection and 99% in the detection of lying bodies. Compared to the conventional method, which uses a static LIDAR, the accuracy reaches for the same tasks 69.4% and 88.6%, respectively.
A Location-Aware Resource Optimization for Maximizing Throughput of Emergency Outdoor–Indoor UAV Communication with FSO/RF
Authors: Guo Zinan , Gao Wei , Ye Haijun , Wang Guofeng
Published: February 2023

In emergency communication scenarios, unmanned aerial vehicles (UAVs) can be used as an air relay to provide higher-quality communication for indoor users. When bandwidth resources are scarce, the use of free space optics (FSO) technology will greatly improve the resource utilization of the communication system. Therefore, we introduce FSO technology into the backhaul link of outdoor communication, and use free space optical/radio frequency (FSO/RF) technology to realize the access link of outdoor indoor communication. The deployment location of UAVs will affect not only the through wall loss of outdoor–indoor communication but also the quality of FSO communication, and, therefore, it needs to be optimized. In addition, by optimizing the power and bandwidth allocation of UAVs, we realize the efficient utilization of resources and improve the system throughput on the premise of considering information causality constraints and user fairness. The simulation results show that, by optimizing the location and power bandwidth allocation of UAVs, the system throughput is maximized, and the throughput between each user is fair.