bluuebunny/crossref_metadata_2025 huggingface dataset:
The Course of Minipuberty in Daughters of Women with Low Gestational Vitamin D Status
Authors: Kowalcze Karolina , Krysiak Robert , Gullo Giuseppe , Ott Johannes
Published: July 2024

Minipuberty is a term describing temporary, sex-specific activation of the hypothalamic–pituitary–gonadal axis, which is implicated in the development of male and female genital organs. Sons of women with low vitamin D during gestation were found to be characterized by increased activity of the reproductive axis and faster postnatal growth of genital organs. The current study assesses for the first time the course of minipuberty in female descendants of women with a vitamin D deficit. The study population included three matched groups of infant girls: children born to women with vitamin D deficiency (25OHD concentration below 50 nmol/L), offspring of women with vitamin D insufficiency (25OHD concentration between 50 and 75 nmol/L), and daughters of healthy females (25OHD concentration between 75 and 150 nmol/L). Salivary concentrations of estradiol, progesterone, 17-hydroxyprogesterone and androgens, as well as urine concentrations of FSH and LH, were assayed during the first 18 months of life (once a month in the first 6 months, bimonthly between months 6 and 12, and then every three months). At each visit, beyond hormone measurements, the investigators assessed the size of reproductive organs: ovaries, uterus and breasts. In daughters of mothers with vitamin D deficiency, concentrations of FSH, LH and estradiol were higher and detectable for a longer period of time, while ovarian volume, uterine length and breast diameter were greater than in the remaining groups. Children born to women with vitamin D insufficiency were characterized by higher FSH levels than daughters of healthy females, though the detection period was the same, and both groups differed in breast diameter. These findings suggest that low vitamin D status during gestation leads to more pronounced and longer-lasting activation of the reproductive axis, and is associated with increased dimensions of sexual organs, the magnitude of which depends on the degree of vitamin D deficit.
6-BA Reduced Yield Loss under Waterlogging Stress by Regulating the Phenylpropanoid Pathway in Wheat
Authors: Gulzar Faiza , Yang Hongkun , Chen Jiabo , Hassan Beenish , Huang Xiulan , Qiong Fangao
Published: July 2024

Waterlogging stress causes substantial destruction to plant growth and production under climatic fluctuations globally. Plants hormones have been widely explored in numerous crops, displaying an imperative role in crop defense and growth mechanism. However, there is a paucity of research on the subject of plant hormones regulating waterlogging stress responses in wheat crop. In this study, we clarified the role of 6-BA in waterlogging stress through inducing phenylpropanoid biosynthesis in wheat. The application of 6-BA (6-benzyladenine) enhanced the growth and development of wheat plants under waterlogging stress, which was accompanied by reduced electrolyte leakage, high chlorophyll, and soluble sugar content. ROS scavenging was also enhanced by 6-BA, resulting in reduced MDA and H2O2 accumulation and amplified antioxidant enzyme activities. Additionally, under the effect of 6-BA, the acceleration of lignin content and accumulation in the cell walls of wheat tissues, along with the activation of PAL (phenylalanine ammonia lyase), TAL (tyrosine ammonia lyase), and 4CL (4-hydroxycinnamate CoA ligase) activities and the increase in the level of transcription of the TaPAL and Ta4CL genes, were observed under waterlogging stress. Also, 6-BA improved the root growth system under waterlogging stress conditions. Further qPCR analysis revealed increased auxin signaling (TaPR1) in 6-BA-treated plants under waterlogging stress that was consistent with the induction of endogenous IAA hormone content under waterlogging stress conditions. Here, 6-BA also reduced yield loss, as compared to control plants. Thus, the obtained data suggested that, under the application of 6-BA, phenylpropanoid metabolism (i.e., lignin) was stimulated, playing a significant role in reducing the negative effects of waterlogging stress on yield, as evinced by the improved plant growth parameters.
Bioactive Compounds in the Oils of the Autochthonous Slovenian Olive Varieties ‘Buga’, ‘Črnica’ and ‘Drobnica’
Authors: Valenčič Vasilij , Bučar-Miklavčič Milena , Podgornik Maja
Published: July 2024

The adaptation of autochthonous olive varieties to local soil and climatic conditions can lead to a unique chemical composition and characteristics of olive oils that may differ from the generally accepted quality standards set out in the International Olive Oil Council strategy documents and EU regulations. Therefore, the fatty acid composition, biophenol, tocopherol, sterol and triterpenic dialcohol content and composition of the autochthonous Slovenian olive varieties ‘Buga’, ‘Črnica’ and ‘Drobnica’ were studied for a three-year period with the aim of valorising the characteristics of the three olive varieties. Standardised and accredited analytical methods in accordance with SIST EN ISO/IEC 17025:2017 were applied. The results of the investigation showed that the highest average amount of oleic acid (75.75%) was found in the oils of the ‘Črnica’ variety, followed by the ‘Drobnica’ (72.06%) and the ‘Buga’ (68.73%). All three varieties are a good source of total biophenols (‘Buga’ 616 mg/kg, ‘Drobnica’ 569 mg/kg and ‘Črnica’ 427 mg/kg) and α-tocopherol (‘Buga’ 378 mg/kg, ‘Drobnica’ 279 mg/kg, and ‘Črnica’ 243 mg/kg). ‘Buga’ and ‘Drobnica’ are characterised by high amounts of total sterols, 2468 mg/kg and 2391 mg/kg, respectively, while ‘Črnica’ oils, in comparison, showed a lower average value of total sterols (1351 mg/kg). Due to their exceptional chemical composition, ‘Buga’, ‘Črnica’ and ‘Drobnica’ show great potential for the further cultivation and valorisation of traditional olive oil production in the region, thus contributing to the preservation of biodiversity and local traditions. The quality parameters of olive oil from the autochthonous Slovenian olive varieties ‘Buga’, ‘Črnica’ and ‘Drobnica’ also fulfil the limits for extra virgin olive oil according to the Commission Delegated Regulation (EU) 2022/2104, despite local climatic influences. However, accelerated growth due to climatic changes affecting early harvest can lead to them falling outside these limits, which was observed in particular for the ‘Buga’ variety in terms of the linoleic acid content. This study emphasises the importance of timing the harvest to achieve optimum maturity and meet EU quality standards, taking into account the genetic makeup of the varieties and their response to the current climatic conditions.
Development of a Reference Transcriptome and Identification of Differentially Expressed Genes Linked to Salt Stress in Salt Marsh Grass (Sporobolus alterniflorus) along Delaware Coastal Regions
Authors: Todd Antonette , Bhide Ketaki , Hayford Rita , Ayyappan Vasudevan , Subramani Mayavan , Chintapenta Lathadevi Karuna , Thimmapuram Jyothi , Ozbay Gulnihal , Kalavacharla Venu (Kal)
Published: July 2024

Salt marsh grass (Sporobolus alterniflorus) plays a crucial role in Delaware coastal regions by serving as a physical barrier between land and water along the inland bays and beaches. This vegetation helps to stabilize the shoreline and prevent erosion, protecting the land from the powerful forces of the waves and tides. In addition to providing a physical barrier, salt marsh grass is responsible for filtering nutrients in the water, offering an environment for aquatic species and presenting a focal point of study for high salt tolerance in plants. As seawater concentrations vary along the Delaware coast from low to medium to high salinity, our study seeks to identify the impact of salt tolerance in marsh grass and to identify genes associated with salt tolerance levels. We developed more than 211,000 next-generation-sequencing (Illumina) transcriptomic reads to create a reference transcriptome from low-, medium-, and high-salinity marsh grass leaf samples collected from the Delaware coastline. Contiguous sequences were annotated based on a homology search using BLASTX against rice (Oryza sativa), foxtail millet (Setaria italica), and non-redundant species within the Viridiplantae database. Additionally, we identified differentially expressed genes related to salinity stress as candidates for salt stress qPCR analysis. The data generated from this study may help to elucidate the genetic signatures and physiological responses of plants to salinity stress, thereby offering valuable insight into the use of innovative approaches for gene expression studies in crops that are less salt tolerant.
Atmospheric Plasma Treatment to Improve PHB Coatings on 316L Stainless Steel
Authors: Radilla J. , Martínez H. , Vázquez O. , Campillo B.
Published: July 2024

In the present study, biopolymeric coatings of polyhydroxybutyrate (PHB) were deposited on 316L stainless steel substrates. The PHB coatings were developed using the spin coating method. To improve the adhesion of the PHB coating on the substrate, this method uses an atmospheric plasma treatment. Adhesion tests show a 156% increase in adhesion after 5 s of surface treatment. Raman spectroscopy analysis of the polymer shows the incorporation of functional groups and the formation of new hydrogen bonds, which can help us bind drugs and promote osteogenesis after plasma treatment. Additionally, the electrochemical behaviors in artificial body fluids (Hanks’ solution) of the PHB coatings on the steel were evaluated with potentiodynamic tests, which revealed a decrease in the corrosion current and resistance to the transfer of the charge from the electrolyte to the 316L steel because of the PHB coating. All the PHB coatings were characterized using scanning electron microscopy and Raman spectroscopy after the electrochemical tests. This analysis confirmed the diffusion of electrolyte species toward the surface and the degradation of the polymer chain for the first 15 s of treatment with atmospheric plasma. These findings support the claim that plasma surface modification is a quick, environmentally friendly, and cost-effective method to enhance the performance of PHB coatings on 316L stainless steel for medical devices.
Protective Encapsulation of a Bioactive Compound in Starch–Polyethylene Glycol-Modified Microparticles: Degradation Analysis with Enzymes
Authors: Valenzuela Villela Karen Sofia , Alvarado Araujo Karen Valeria , Garcia Casillas Perla Elvia , Chapa González Christian
Published: July 2024

Starch is a promising polymer for creating novel microparticulate systems with superior biocompatibility and controlled drug delivery capabilities. In this study, we synthesized polyethylene glycol (PEG)-modified starch microparticles and encapsulated folic acid using a solvent-mediated acid-base precipitation method with magnetic stirring, which is a simple and effective method. To evaluate particle degradation, we simulated physiological conditions by employing an enzymatic degradation approach. Our results with FTIR and SEM confirmed the successful synthesis of starch–PEG microparticles encapsulating folic acid. The average size of starch microparticles encapsulating folic acid was 4.97 μm and increased to 6.01 μm upon modification with PEG. The microparticles were first exposed to amylase at pH 6.7 and pepsin at pH 1.5 at different incubation times at physiological temperature with shaking. Post-degradation analysis revealed changes in particle size and morphology, indicating effective enzymatic degradation. FTIR spectroscopy was used to assess the chemical composition before and after degradation. The initial FTIR spectra displayed characteristic peaks of starch, PEG, and folic acid, which showed decreased intensities after enzymatic degradation, suggesting alterations in chemical composition. These findings demonstrate the ongoing development of starch–PEG microparticles for controlled drug delivery and other biomedical applications and provide the basis for further exploration of PEG–starch as a versatile biomaterial for encapsulating bioactive compounds.
A Critical Review of Systems for Bioremediation of Tannery Effluent with a Focus on Nitrogenous and Sulfurous Species Removal and Resource Recovery
Authors: Ngobeni Philadelphia V. , Mpofu Ashton B. , Ranjan Amrita , Welz Pamela J.
Published: July 2024

Tanneries generate copious amounts of potentially toxic sludge and effluent from the processing of skins and hides to leather. The effluent requires remediation before discharge to protect the receiving environment. A range of physicochemical methods are used for pre- and post-treatment, but biological secondary remediation remains the most popular choice for the reduction of the organic and macronutrient fraction of tannery effluent. This review provides an update and critical discussion of biological systems used to remediate tannery effluent. While the conventional activated sludge process and similar technologies are widely used by tanneries, they have inherent problems related to poor sludge settling, low removal efficiencies, and high energy requirements. Treatment wetlands are recommended for the passive polishing step of beamhouse effluent. Hybrid systems that incorporate anoxic and/or anaerobic zones with sludge and/or effluent recycling have been shown to be effective for the removal of organics and nitrogenous species at laboratory scale, and some have been piloted. Novel systems have also been proposed for the removal and recovery of elemental sulfur and/or energy and/or process water in support of a circular economy. Full-scale studies showing successful long-term operation of such systems are now required to convince tanneries to modernize and invest in new infrastructure.
Research on Gas Control Technology in Goaf Based on the Influence of Mining Speed
Authors: Cheng Cheng , Cheng Xiao-Yu , Chen Long , Ma Xing-Ying
Published: July 2024

To comprehensively understand the influence of mining speed on gas emissions in goaf during coal seam extraction, enhance gas extraction efficiency in goaf, manage gas emissions at the working face, and ensure safety in the mining production process. This study focuses on the No. 3 mining area of Wangjialing Mine, employing numerical simulations to analyze the evolution of mining-induced fractures and the characteristics of gas distribution in the overburden at varying mining speeds. Furthermore, by integrating actual gas emission and extraction data at the production face, this study examines the quantitative relationship between mining speed and gas emissions in the goaf, identifying optimal regions for high-position borehole layouts and conducting borehole optimization design and investigation. The results of this study indicate that the initial caving step distance of the goaf roof increases with the advancement speed of the working face. Conversely, the maximum height of through fractures in the overburden decreases as the mining speed increases, while delamination fractures are minimally affected by the advancement speed. By categorizing and averaging data on goaf mining speed, the impact of initial and periodic pressure on gas emissions can be effectively mitigated, revealing a linear correlation coefficient of 0.94 between goaf gas emissions and mining speed. At varying mining speeds of the working face, the efficient extraction layer and horizontal distance parameters of gas extraction boreholes in the goaf conform to the linear equation y = ax ± b. Based on the research findings, an optimization design for mining face speed and high-level borehole parameters in the goaf was implemented. The average gas extraction rate of high-level directional boreholes reached 68% throughout the extraction period. Gas emissions at the working face were effectively controlled below 10 m3/min, with the maximum gas concentration at the upper corners and return airflow kept below 0.8%. This effectively managed gas emissions at the working face, ensuring safe production in the mine, providing a theoretical basis for identifying gas-rich areas in the mining-induced overburden, and enhancing gas extraction efficiency at the working face.
Fracture Propagation of Multi-Stage Radial Wellbore Fracturing in Tight Sandstone Reservoir
Authors: Yong Yuning , Guo Zhaoquan , Zhou Xiaoxia , Tian Shouceng , Zhang Ye , Wang Tianyu
Published: July 2024

Radial wellbore fracturing is a promising technology for stimulating tight sandstone reservoirs. However, simultaneous fracturing of multiple radial wellbores often leads to unsuccessful treatments. This paper proposes a novel technology called multi-stage radial wellbore fracturing (MRWF) to address this challenge. A numerical model based on the finite element/meshfree method is established to investigate the effects of various parameters on the fracture propagation of MRWF, including the azimuth of the radial wellbore, the horizontal stress difference, and the rock matrix permeability. The results show that previously created fractures have an attraction for subsequently created fractures, significantly influencing fracture propagation. A conceptual model is proposed to explain the variations in the fracture propagation of MRWF, highlighting three critical effect factors: the attraction effect, the orientation effect of the radial wellbore, and the deflection effect of the maximum horizontal principal stress. Fracture geometry is quantitatively assessed through the deviation distance, which indicates the radial wellbore’s ability to guide fracture propagation along its axis. As the azimuth increases, the deviation distances can either increase or decrease, depending on the specific radial wellbore layouts. Decreasing the horizontal stress difference and increasing the rock matrix permeability both increase the deviation distance.
Developing Lead Compounds of eEF2K Inhibitors Using Ligand–Receptor Complex Structures
Authors: Xu Jiangcheng , Yu Wenbo , Luo Yanlin , Liu Tiantao , Su An
Published: July 2024

The eEF2K, a member of the α-kinase family, plays a crucial role in cellular differentiation and the stability of the nervous system. The development of eEF2K inhibitors has proven to be significantly important in the treatment of diseases such as cancer and Alzheimer’s. With the advancement of big data in pharmaceuticals and the evolution of molecular generation technologies, leveraging artificial intelligence to expedite research on eEF2K inhibitors shows great potential. Based on the recently published structure of eEF2K and known inhibitor molecular structures, a generative model was used to create 1094 candidate inhibitor molecules. Analysis indicates that the model-generated molecules can comprehend the principles of molecular docking. Moreover, some of these molecules can modify the original molecular frameworks. A molecular screening strategy was devised, leading to the identification of five promising eEF2K inhibitor lead compounds. These five compound molecules demonstrated excellent thermodynamic performance when docked with eEF2K, with Vina scores of −12.12, −16.67, −15.07, −15.99, and −10.55 kcal/mol, respectively, showing a 24.27% improvement over known active inhibitor molecules. Additionally, they exhibited favorable drug-likeness. This study used deep generative models to develop eEF2K inhibitors, enabling the treatment of cancer and neurological disorders.
Concentration of Silver from Recycling of Fine Powder of Wasted Videogame Printed Circuit Boards through Reverse Froth Flotation and Magnetic Separation Processes
Authors: Flores-Campos Rubén , Estrada-Ruiz Rosa Hilda , Rodríguez-Reyes Mario , Martínez-Carrillo Diego , Martínez-Luévanos Antonia
Published: July 2024

Electronic waste stream grows day by day; printed circuit boards are a kind of solid waste that accounts for 6% of electronic waste. When these are discarded, they can cause soil, water, and air contamination; however, if recycled, these can be considered as a secondary source of metals. Physical comminution of printed circuit boards generates particles with sizes smaller than 250 µm, which are typically not included in the recycling process because they are considered as dust and unvaluable; nevertheless, precious and base metals can be found in these particles. The concentration of metals like silver, among others, from these particles can be achieved by reverse froth flotation in a flotation column followed by magnetic separation of the tails products. A mass balance of the flotation column feed, concentrate, and tails indicates that using a pulp modified with 5 ppm methyl isobutyl carbinol plus 5 g/ton oleic acid (both biodegradable reagents), the concentration of the products improved, resulting in recoveries of 86.13 and 13.87% in the concentrate and tails zones, respectively, with a grade of 74.4% in the tails flow. Magnetic separation of the tails product increases slightly the concentration of silver, reaching a silver grade of 74.5%, a recovery amount similar to those obtained employing complex and environmentally unfriendly processes.
A Reconfigurable UGV for Modular and Flexible Inspection Tasks in Nuclear Sites
Authors: Villaverde Ivan , Urquiza Arkaitz , Outón Jose Luis
Published: July 2024

Current operations involving Dismantling and Decommissioning (D&D) in nuclear and other harsh environments rely on manual inspection and assessment of the sites, exposing human operators to potentially dangerous situations. This work presents a reconfigurable Autonomous Mobile Robot (AMR) able to mount a wide range of nuclear sensors for flexible and modular inspection tasks in these operations. This AMR is part of the CLEANDEM solution, which uses Unmanned Ground Vehicles (UGVs), nuclear sensors, and a Digital Twin to facilitate a tool for improving D&D operations in nuclear sites. Both the AMR used as a UGV and the system have been successfully tested in real nuclear sites, showing that these tools can greatly aid in operations management and hazard reduction.
Long-Term Evaluation of Aerosol Optical Properties in the Levantine Region: A Comparative Analysis of AERONET and Aqua/MODIS
Authors: Isik Ayse Gokcen , Aslanoğlu S. Yeşer , Güllü Gülen
Published: July 2024

The focus on aerosol analysis in the Levantine Region is driven by climate-change impacts, the region’s increasing urban development and industrial activities, and its geographical proximity to major dust-source areas. This study conducts a comparative analysis of aerosol optical depth data from Aqua/MODIS and AERONET during different periods between 2003 and 2023 at four stations: IMS-METU-ERDEMLI (Mersin/Türkiye) (2004–2019), CUT-TEPAK (Limassol/Cyprus) (2010–2023), Cairo_EMA_2 (Cairo/Egypt) (2010–2023), and SEDE_BOKER (Sede Boker/Israel) (2003–2023). The objective is to evaluate the variability and reliability of AOD measurements between satellite and ground-based observations and to determine how well they represent regional climatology. The highest percentage of measurements within the expected error envelope was observed at the IMS-METU-ERDEMLI station, indicating the best agreement between MODIS and AERONET data at this location. The Seasonal-Trend Decomposition using Loess (STL) method revealed consistent spring and summer peaks influenced by dust transport from the Sahara and the Middle East, with lower values in winter. The study also considers the influence of cloud fraction on MODIS measurements and includes aerosol classification. A statistically significant slight positive trend in AOD values was identified at the IMS-METU-ERDEMLI station. Conversely, no significant trends were detected at the other stations. The results of this study agree with those of previous research on the impact of long-range dust transport on regional aerosol loadings, emphasizing the importance of integrating satellite and ground-based observations.
The Impact of Polar Vortex Strength on the Longitudinal Structure of the Noontime Mid-Latitude Ionosphere and Thermosphere
Authors: Perrone Loredana , Mikhailov Andrey
Published: July 2024

Ground-based ionospheric, CHAMP/STAR, and GOCE satellite neutral density ρ observations under deep solar minimum conditions were used to find whether there is a dependence of longitudinal variations on polar vortex strength. Ionospheric stations at fixed-dipole geomagnetic Φ ≈ 38° and geographic φ ≈ 40°N latitudes located in ‘near-pole’ and ‘far-from-pole’ longitudinal sectors were used in the analysis. No significant longitudinal NmF2 (electron concentration in the F2-layer maximum) dependence on the polar vortex strength was revealed. Geomagnetic control was shown to be responsible for the observed longitudinal NmF2 variations. Satellite-observed longitudinal variations in neutral density did not show any visible reaction to the polar vortex strength. However, the impact of sudden stratospheric warming (SSW) on the upper atmosphere is strong enough to change the neutral density longitudinal distribution. The impact of SSW shows a global occurrence and ‘works’ within 3–5 days in geographic coordinates in the vicinity of the SSW peak. Atomic oxygen values retrieved under ‘strong’ and ‘weak’ polar vortex strengths confirm the results obtained on longitudinal variations in NmF2 and ρ. In conclusion, no visible effects related to ‘strong’ or ‘weak’ polar vortex strengths have been revealed in either NmF2 or satellite neutral density longitudinal variations. Alternatively, such effects may be very small and therefore cannot be confirmed experimentally.
Segment Anything Model-Based Building Footprint Extraction for Residential Complex Spatial Assessment Using LiDAR Data and Very High-Resolution Imagery
Authors: Ji Yingjie , Wu Weiguo , Wan Guangtong , Zhao Yindi , Wang Weilin , Yin Hui , Tian Zhuang , Liu Song
Published: July 2024

With rapid urbanization, retrieving information about residential complexes in a timely manner is essential for urban planning. To develop efficiency and accuracy of building extraction in residential complexes, a Segment Anything Model-based residential building instance segmentation method with an automated prompt generator was proposed combining LiDAR data and VHR remote sensing images in this study. Three key steps are included in this method: approximate footprint detection using LiDAR data, automatic prompt generation for the SAM, and residential building footprint extraction. By applying this method, residential building footprints were extracted in Pukou District, Nanjing, Jiangsu Province. Based on this, a comprehensive assessment model was constructed to systematically evaluate the spatial layout of urban complexes using six dimensions of assessment indicators. The results showed the following: (1) The proposed method was used to effectively extract residential building footprints. (2) The residential complexes in the study area were classified into four levels. The numbers of complexes classified as Excellent, Good, Average, and Poor were 10, 29, 16, and 1, respectively. Residential complexes of different levels exhibited varying spatial layouts and building distributions. The results provide a visual representation of the spatial distribution of residential complexes that belong to different levels within the study area, aiding in urban planning.
The Nighttime Horizontal Neutral Winds at Mohe Station in Response to the Temporal Oscillations of Interplanetary Magnetic Field Bz
Authors: Zhang Kedeng , Wang Hui , Zheng Chunxin , Yin Tiantian , Liu Zhenzhu
Published: July 2024

Temporal oscillations in the IMF Bz associated with Alfvén waves occur frequently in solar wind, with a duration ranging from minutes to hours. Using Swarm observations, Fabry–Pérot interferometer measurements at Mohe station, and Thermosphere–Ionosphere–Electrodynamic General Circulation Model simulations, the perturbations of zonal (ΔUN) and meridional (ΔVN) winds due to temporal oscillations in the IMF Bz on 23–24 April 2023 are explored in the following work. ΔUN is strong westward with a speed of greater than 100 m/s at pre-midnight on 23–24 April. This phenomenon is primarily driven by the pressure gradient, offsetting by the ion drag and Coriolis force. On 23 April, ΔVN is weak northward at the pre-midnight and strong southward at a speed of ~200 m/s at pre-dawn. On 24 April, ΔVN is strong (weak) northward at pre-midnight (pre-dawn). It is mainly controlled by a balance between the pressure gradient, ion drag, and Coriolis force.
Modelling and Mitigating Wind Turbine Clutter in Space–Air Bistatic Radar
Authors: Zhang Shuo , Zhang Shuangxi , Qiao Ning , Wang Yongliang , Du Qinglei
Published: July 2024

The extensive deployment of wind farms has significantly impacted the detection capabilities of space–air bistatic radar (SABR) systems. Although space–time adaptive processing techniques are available, their performance is significantly degraded, and even unable to suppress clutter. This paper explores the geometric configuration of the SABR system and the selection of detection areas, establishing a space–time clutter model that addresses the effects of wind turbine clutter (WTC). Expressions for spatial and Doppler frequencies have been derived to deeply analyze the characteristics of clutter spreading. Building on this, the paper extends two-dimensional space–time data to three-dimensional azimuth–elevation–Doppler data. It proposes a three-dimensional space–time multi-beam (STMB) strategy incorporating the Ordering Points to Identify the Clustering Structure (OPTICS) clustering algorithm to suppress WTC effectively. This algorithm selects WTC samples and applies OPTICS clustering to the clutter-suppressed data to achieve this effect. Simulation experiments further verify the effectiveness of the algorithm.
Estimation of Actual Evapotranspiration and Water Stress in Typical Irrigation Areas in Xinjiang, Northwest China
Authors: Zhao Siyu , Huang Yue , Liu Zhibin , Liu Tie , Tang Xiaoyu
Published: July 2024

The increasing water demand and the disparities in the spatiotemporal distribution of water resources will lead to increasingly severe water shortages in arid areas. Accurate evapotranspiration estimation is the basis for evaluating water stress and informing sustainable water resource management. In this study, we constructed a surface energy balance algorithm for land (SEBAL) model based on the Google Earth Engine platform to invert the actual evapotranspiration (ETa) in typical irrigation areas in Xinjiang, northwest China, during the growing season from 2005 to 2021. The inversion results were evaluated using the observed evaporation data and crop evapotranspiration estimated by the FAO Penman–Monteith method. The water stress index (WSI) was then calculated based on the simulated ETa. The impacts of climatic factors, hydrological conditions, land-use change, and irrigation patterns on ETa and WSI were analyzed. The results indicated the following: (1) The ETa simulated by the SEBAL model matched well with the observed data and the evapotranspiration estimated using the FAO Penman–Monteith approach, with correlation coefficients greater than 0.7. (2) The average ETa was 704 mm during the growing season, showing an increasing trend in the irrigation area of the Yanqi Basin (IAY), whereas for the irrigation area of Burqin (IAB) the average ETa was 677 mm during the growing season, showing an increasing trend. The land cover type mainly influenced the spatial distribution of ETa in the two study areas. (3) The WSI in both irrigation areas exhibited a decreasing trend, with the WSI in the IAY lower than that in the IAB. (4) Climate warming, increases in irrigation areas, and changes in cropping patterns led to increased ETa in the IAY and IAB; the overall decreasing trend in the WSI derived from the popularization of agricultural water-saving irrigation patterns in both regions, which reduces ineffective evapotranspiration and contributes positively to solving the water shortage problem in the basins. This study provides insight into water resource management in the Xinjiang irrigation areas.
Precise Motion Compensation of Multi-Rotor UAV-Borne SAR Based on Improved PTA
Authors: Cheng Yao , Qiu Xiaolan , Meng Dadi
Published: July 2024

In recent years, with the miniaturization of high-precision position and orientation systems (POS), precise motion errors during SAR data collection can be calculated based on high-precision POS. However, compensating for these errors remains a significant challenge for multi-rotor UAV-borne SAR systems. Compared with large aircrafts, multi-rotor UAVs are lighter, slower, have more complex flight trajectories, and have larger squint angles, which result in significant differences in motion errors between building targets and ground targets. If the motion compensation is based on ground elevation, the motion error of the ground target will be fully compensated, but the building target will still have a large residual error; as a result, although the ground targets can be well-focused, the building targets may be severely defocused. Therefore, it is necessary to further compensate for the residual motion error of building targets based on the actual elevation on the SAR image. However, uncompensated errors will affect the time–frequency relationship; furthermore, the ω-k algorithm will further change these errors, resulting in errors in SAR images becoming even more complex and difficult to compensate for. To solve this problem, this paper proposes a novel improved precise topography and aperture-dependent (PTA) method that can precisely compensate for motion errors in the UAV-borne SAR system. After motion compensation and imaging processing based on ground elevation, a secondary focus is applied to defocused buildings. The improved PTA fully considers the coupling of the residual error with the time–frequency relationship and ω-k algorithm, and the precise errors in the two-dimensional frequency domain are determined through numerical calculations without any approximations. Simulation and actual data processing verify the effectiveness of the method, and the experimental results show that the proposed method in this paper is better than the traditional method.
Weak-Texture Seafloor and Land Image Matching Using Homography-Based Motion Statistics with Epipolar Geometry
Authors: Chen Yifu , Le Yuan , Wu Lin , Zhang Dongfang , Zhao Qian , Zhang Xueman , Liu Lu
Published: July 2024

The matching of remote sensing images is a critical and necessary procedure that directly impacts the correctness and accuracy of underwater topography, change detection, digital elevation model (DEM) generation, and object detection. The texture of images becomes weaker with increasing water depth, and this results in matching-extraction failure. To address this issue, a novel method, homography-based motion statistics with an epipolar constraint (HMSEC), is proposed to improve the number, reliability, and robustness of matching points for weak-textured seafloor images. In the matching process of HMSEC, a large number of reliable matching points can be identified from the preliminary matching points based on the motion smoothness assumption and motion statistics. Homography and epipolar geometry are also used to estimate the scale and rotation influences of each matching point in image pairs. The results show that the matching-point numbers for the seafloor and land regions can be significantly improved. In this study, we evaluated this method for the areas of Zhaoshu Island, Ganquan Island, and Lingyang Reef and compared the results to those of the grid-based motion statistics (GMS) method. The increment of matching points reached 2672, 2767, and 1346, respectively. In addition, the seafloor matching points had a wider distribution and reached greater water depths of −11.66, −14.06, and −9.61 m. These results indicate that the proposed method could significantly improve the number and reliability of matching points for seafloor images.
Ammasso Silo Characterization and Repurposing
Authors: Marcelo Víctor , Faugno Salvatore , López-Díez Francisco Javier , Pastrana Pablo , Valenciano José B.
Published: July 2024

Italy built its ammasso silo network in the 1930s for two purposes: to stockpile grain and to symbolize fascist power. Much of the network was destroyed in World War II, and over half of the silos still standing are now disused and in disrepair. These structures should be protected and refurbished because they are part of Italy’s historic and agro-industrial heritage and because reusing existing buildings instead of constructing new ones reduces the carbon footprint. To evaluate silo repurposing potential, a method developed for inventorying Spanish silos was adapted and applied to the 30 remaining ammasso silos. The method explores the general features, construction, equipment, and socioeconomic environment of each silo. All extant ammasso silos have machinery for receiving, storing, and dispatching grain, and most have equipment for cleaning, sorting, weighing, and packaging. Vertical-cell silos are challenging to convert, unlike horizontally-oriented silos and other open-plan agro-industrial buildings. Even so, some have already been made over into shops, leisure areas, museums, and even homes. Examples of silo reuse in other countries, such as Spain and Portugal, can offer further useful insights. However, socio-economic indicators suggest that silo repurposing projects are viable only in large population centres.
Comparison of Scenedesmus obliquus in CO2 Capture, Biolipid Production and Nutrient Removal
Authors: Cao Wenwen , Yu Hongfei , Dong Wei , Rong Zijia , Peng Dianbao , Chen Fukun , Li Lixin
Published: July 2024

The cultivation of microalgae from municipal wastewater, while simultaneously removing nutrients from the water column, has the potential to aid biodiesel production and carbon dioxide fixation, thereby alleviating the pressure of energy shortages. In this research, different ratios of sodium bicarbonate and glucose were used to prepare simulated municipal wastewater. The results demonstrated that microalgae were most effectively treated under one-stage direct treatment conditions. During direct culture, the most effective treatment was observed for IAA-3, which exhibited a dry weight of 1.4363 g/L and a lipid content of 25.05% after stimulation with 0.0005 M NaHCO3. In contrast, NaHCO3-2 demonstrated optimal performance during the secondary culture, with a dry weight of 1.6844 g/L and a lipid content of 18.05%. Finally, the economic, social and environmental benefits of direct treatment (IAA-3) and secondary treatment NaHCO3-2 were analyzed. The benefits of direct treatment were found to be USD 0.50989/L, while those of secondary treatment were USD 0.43172/L. For each tonne of municipal wastewater treated, the carbon sequestration benefits of IAA-3 during direct treatment and NaHCO3-2 during secondary treatment were USD 0.45645 and USD 0.85725, respectively.
Hydrogen–Water Isotope Catalytic Exchange Process Analysis by Simulation
Authors: Hou Jingwei , Li Jiamao , Xiao Chengjian , Wang Heyi , Peng Shuming
Published: July 2024

The hydrogen–water isotope catalytic exchange process has been widely applied in the tritium-containing water treatment process. It can be compared and analyzed conveniently with process simulation software. In this study, the catalytic exchange process was simulated by Aspen Plus software (V11). According to the simulation results, the main reaction process was that HDO in the liquid phase converts into HD in the gas phase, and the reaction mainly occurred at the bottom of the column, exhibiting a two-orders-of-magnitude-higher reaction amount compared to that observed in the top section. Different side reactions occur at distinct positions along the column, exhibiting a reaction amount that is lower by one to two orders of magnitude compared to the main reaction and aligning in the same direction as the main reaction. The optimum operating temperature is 60~80 °C, with the best performance observed at 70 °C, because of the large reaction equilibrium constant and the suitable ratio of vapor to hydrogen (1:4~1:1.5) in the gas phase. The influence of the residence time was investigated by introducing reaction kinetic equations. The residence time should be more than 1 s to ensure an adequate reaction. The influence of operating conditions on the hydrogen–water isotope catalytic exchange process can be deeply investigated by process simulation, and more mass transfer process quantities can be obtained. It plays a promoting role in guiding the process design and condition optimization.
Complementarity of Sentinel-1 and Sentinel-2 Data for Soil Salinity Monitoring to Support Sustainable Agriculture Practices in the Central Bolivian Altiplano
Authors: Sirpa-Poma J. W. , Satgé F. , Pillco Zolá R. , Resongles E. , Perez-Flores M. , Flores Colque M. G. , Molina-Carpio J. , Ramos O. , Bonnet M.-P.
Published: July 2024

Soil salinization will affect 50% of global cropland areas by 2050 and represents a major threat to agricultural production and food sovereignty. As soil salinity monitoring is costly and time consuming, many regions of the world undertake very limited soil salinity observation (in space and time), preventing the accurate assessment of soil salinity hazards. In this context, this study assesses the relative performance of Sentinel-1 radar and Sentinel-2 optical images, and the combination of the two, for monitoring changes in soil salinity at high spatial and temporal resolution, which is essential to evaluate the mitigation measures required for the sustainable adaptation of agriculture practices. For this purpose, an improved learning database made of 863 soil electrical conductivity (i.e., soil salinity) observations is considered for the training/validation step of a Random Forest (RF) model. The RF model is successively trained with (1) only Sentinel-1, (2) only Sentinel-2 and (3) both Sentinel-1 and -2 features using the Genetic Algorithm (GA) to reduce multi-collinearity in the independent variables. Using k-fold cross validation (3-fold), overall accuracy (OA) values of 0.83, 0.88 and 0.95 are obtained when considering only Sentinel-2, only Sentinel-1 and both Sentinel-1 and -2 features as independent variables. Therefore, these results highlight the clear complementarity of radar (i.e., Sentinel-1) and optical (i.e., Sentinel-2) images to improve soil salinity mapping, with OA increases of approximately 10% and 7% when compared to Sentinel-2 and Sentinel-1 alone. Finally, pre-sowing soil salinity maps over a five-year period (2019–2023) are presented to highlight the benefit of the proposed procedure to support the sustainable management of agricultural lands in the context of soil salinization on a regional scale.
Preparation of Gypsum–Urea with Enhanced Sustainability from Flue Gas Desulfurization Gypsum in Saturated Urea Solution
Authors: Jia Caiyun , Zhao Jiang , Fang Xiaoxia , Wang Pujun , Xiao Anni , Zhang Haijun
Published: July 2024

Gypsum–urea is a kind of urea product with substantially reduced aqueous solubility and lower hygroscopicity that increases the soil retention time of urea and thus enhance its environmental sustainability. Here, gypsum–urea was prepared using bulk industrial solid waste flue gas desulfurization (FGD) gypsum as a raw material in a saturated urea solution via immobilizing urea molecules into the crystal lattice. The preparation process was achieved through a dissolution–recrystallization mechanism during which FGD gypsum dissolved into Ca2+ and SO42−, which then recrystallized with CO(NH2)2 to form gypsum–urea. The preparation process was almost completed within 10 min, and the formed gypsum–urea presented a uniform size distribution of 30–90 μm and a much lower hygroscopicity and nitrogen release efficiency than that of urea. With a high efficiency of synthesis, and sustainable features, and the recyclability of the saturated mother urea solution, the dissolution–recrystallization-based urea immobilization approach is highly promising regarding the preparation of gypsum–urea with the desired environmental sustainability and contributes to the realization of the sustainable reutilization of FGD gypsum.
Assessment of the Quantities of Non-Targeted Materials (Impurities) in Recycled Plastic Packaging Waste to Comply with EU Regulations and Sustainable Waste Management
Authors: Waszczyłko-Miłkowska Beata , Bernat Katarzyna , Szczepański Krystian
Published: July 2024

Plastic packaging waste (PPW) can be considered as solid waste with harmful effects on the environment or as a material with recycling potential in terms of sustainable development in a circular economy. Knowing the amount of PPW generated is very important as it is related to the availability of this material for recycling and determines the actual recycling rate (denominator of a fraction). PPW is very heterogeneous and contains a certain number of impurities (e.g., product residues, direct printing, glue, labels, plastic sleeves, cap, etc.). According to EU law, an annual report (for the data in 2021) on the masses of both the PPW actually recycled (PPWR) (“targeted materials”) and impurities (“non-targeted materials”) must be prepared and submitted to the European Commission. The PPWR is used for the calculation of the recycling rate (the numerator in a fraction). The impurities should be considered for the calculation of own resources (national contributions to the general EU budget based on the uniform call rate of 0.80/kg of non-recycled PPW). To date, the Council of the EU has not proposed a method for calculating these amounts, so they have only been estimated. The present study (the first of its kind in Poland) aimed to estimate the number of impurities in PPW and the actual amount of PPWR at the calculation point using a method accepted by the EU. In the installations, PPW (plastic packaging (15 01 02), multi-material packaging (15 01 05) and mixed packaging waste (15 01 06)) is recycled together with other plastic waste (plastic (16 01 19), plastic (17 02 03), plastic and rubber (19 12 04), and plastics (20 01 39)). It was assumed that the proportions of the mass of individual types of PPW in the total mass of plastic waste processed in the installation were proportional to the mass of impurities in these individual types of PPW. It was found that the average percentage of impurities in PPW was 4.40–6.90%, which seems to be relatively low. However, this means that, when calculating the PPWR, the mass of impurities should be subtracted from the mass of PPW entering the recycling process. As a result, the mass of PPWR at the calculation point in 2021 in Poland was almost 30,000 tonnes lower than the original mass entering the installation. Thus, applying the uniform call rate to the weight of impurities in the PPW increases Poland’s own resources by approx. 24 million euros.
Sustainability and Dividends: Complements or Substitutes?
Authors: Krieger Kevin , Mauck Nathan
Published: July 2024

We examine the relationship between environmental, social, and governance commitment levels (ESG) and firm dividend-payer status. Given that larger and more profitable firms are positively associated with both payer status and ESG, it could be that ESG and dividends are complements. However, given that both dividends and ESG relate to firm spending decisions, it may be that the choice is “either/or”, and that ESG and dividends are substitutes. We document a positive relationship between ESG and dividend-payer status in U.S. firms over the period 1991–2016. In particular, we find that the proportion of dividend-payers is roughly 13% higher for firms with positive ESG compared to those with negative ESG. Including ESG in the models used to predict payer status provides, on average, a nearly 26% improvement in relative forecast accuracy. Our results are robust in regards to estimation techniques and the inclusion of variables known to be determinants of payer status. The results indicate that, on average, firms are not forced to sacrifice dividends in favor of ESG spending.