bluuebunny/crossref_metadata_2025 huggingface dataset:
Heterogeneous Hybrid Nanocomposite Based on Chitosan/Magnesia Hybrid Films: Ecofriendly and Recyclable Solid Catalysts for Organic Reactions
Authors: Madkour Metwally , Khalil Khaled D. , Al-Sagheer Fakhreia A.
Published: October 2021

Chitosan/magnesia hybrid films (CS-Mg) have been prepared via sol-gel process and employed as heterogeneous catalysts. An in situ generation of a magnesia network in the chitosan matrix was performed through hydrolysis/condensation reactions of magnesium ethoxide. The synthesized hybrid films were characterized using various analytical techniques, such as X-ray photo-electron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The hybrid films display excellent catalytic activities in Michael and Knoevenagel reactions via one pot or solvent-free approaches under microwave irradiation conditions. Chitosan/magnesia hybrid films, catalysed pyrimidine, benzochromene, coumarin and arylidene-malononitriles derivatives formation reactions occurred with highly efficient yields of 97%, 92%, 86% and 95% respectively. Due to the fact that the films are durable and insoluble in common organic solvents, they were easily separated and can be recycled up to five times without a considerable loss of their catalytic activity.
SBMLWebApp: Web-Based Simulation, Steady-State Analysis, and Parameter Estimation of Systems Biology Models
Authors: Yamada Takahiro G. , Ii Kaito , König Matthias , Feierabend Martina , Dräger Andreas , Funahashi Akira
Published: October 2021

In systems biology, biological phenomena are often modeled by Ordinary Differential Equations (ODEs) and distributed in the de facto standard file format SBML. The primary analyses performed with such models are dynamic simulation, steady-state analysis, and parameter estimation. These methodologies are mathematically formalized, and libraries for such analyses have been published. Several tools exist to create, simulate, or visualize models encoded in SBML. However, setting up and establishing analysis environments is a crucial hurdle for non-modelers. Therefore, easy access to perform fundamental analyses of ODE models is a significant challenge. We developed SBMLWebApp, a web-based service to execute SBML-based simulation, steady-state analysis, and parameter estimation directly in the browser without the need for any setup or prior knowledge to address this issue. SBMLWebApp visualizes the result and numerical table of each analysis and provides a download of the results. SBMLWebApp allows users to select and analyze SBML models directly from the BioModels Database. Taken together, SBMLWebApp provides barrier-free access to an SBML analysis environment for simulation, steady-state analysis, and parameter estimation for SBML models. SBMLWebApp is implemented in Java™ based on an Apache Tomcat® web server using COPASI, the Systems Biology Simulation Core Library (SBSCL), and LibSBMLSim as simulation engines. SBMLWebApp is licensed under MIT with source code freely available. At the end of this article, the Data Availability Statement gives the internet links to the two websites to find the source code and run the program online.
Research of Flow Stability of Non-Newtonian Magnetorheological Fluid Flow in the Gap between Two Cylinders
Authors: Kozubková Milada , Jablonská Jana , Bojko Marian , Pochylý František , Fialová Simona
Published: October 2021

This paper deals with a mathematical modeling of flow stability of Newtonian and non-Newtonian fluids in the gap between two concentric cylinders, one of which rotates. A typical feature of the flow is the formation of a vortex flow, so-called Taylor vortices. Vortex structures are affected by the speed of the rotating cylinder and the physical properties of the fluids, i.e., viscosity and density. Analogy in terms of viscosity is assumed for non-Newtonian and magnetorheological fluids. Mathematical models of laminar, transient and turbulent flow with constant viscosity and viscosity as a function of the deformation gradient were formulated and numerically solved to analyze the stability of single-phase flow. To verify them, a physical experiment was performed for Newtonian fluids using visualizations of vortex structures—Taylor vortices. Based on the agreement of selected numerical and physical results, the experience was used for numerical simulations of non-Newtonian magnetorheological fluid flow.
Wet Torrefaction of Poultry Litter in a Pilot Unit: A Numerical Assessment of the Process Parameters
Authors: Isemin Rafail , Marias Frederic , Muratova Natalia , Kuzmin Sergey , Klimov Dmitry , Mikhalev Alexander , Milovanov Oleg , Brulé Mathieu , Tabet Fouzi
Published: October 2021

A numerical model for the wet torrefaction of poultry litter in a pilot unit was developed in this study. The model accounted for the following process steps: preheating biomass in a feed hopper, feeding biomass into the reactor, fluidized-bed generation using superheated steam, and the supply of additional heat by the electric heating of the reactor walls. Following a “black box” approach, a major assumption of the model is that the behavior of the fluidized-bed reactor is similar to a completely stirred tank reactor (CSTR). Under this assumption, the properties of the particles and gases do not depend on their location inside the reactor. During wet torrefaction, poultry-litter biomass was heated to a predetermined temperature and decomposed, generating biochar along with a gas phase (torgas), whose amounts depended on the content of inert ash in the biomass particles. Variable optimization in the model was performed using MATLAB software. The model successfully estimated the optimal duration required for the completion of wet torrefaction under various conditions: temperature, batch weight, reactor dimensions, etc. The model was validated using experimental data obtained from a series of wet torrefaction experiments performed in a fluidized bed, and provided reliable estimations of the duration of the process depending on material properties, reactor size and feedstock characteristics.
Comprehensive Understanding of Roller Milling on the Physicochemical Properties of Red Lentil and Yellow Pea Flours
Authors: Pulivarthi Manoj Kumar , Nkurikiye Eric , Watt Jason , Li Yonghui , Siliveru Kaliramesh
Published: October 2021

The development of convenience foods by incorporating nutrient-rich pulses such as peas and lentils will tremendously alter the future of pulse and cereal industries. However, these pulses should be size-reduced before being incorporated into many food products. Therefore, an attempt was made to adapt roller mill settings to produce de-husked yellow pea and red lentil flours. The milling flowsheets unique to yellow peas and red lentils were developed in producing small, medium, and large flours with maximum yield and flour quality. This study also investigated the differences in chemical composition, physical characteristics, and particle size distributions of the resultant six flour fractions. The kernel dimensions and physicochemical properties of the whole yellow pea and red lentils were also studied to develop customized mill settings. Overall, the mill settings had a significant effect on the physical properties of different particle-sized flours. The geometric mean diameters of different particle-sized red lentil flours were 56.05 μm (small), 67.01 μm (medium), and 97.17 μm (large), while for yellow pea flours they were 41.38 μm (small), 60.81 μm (medium), and 98.31 μm (large). The particle size distribution of all the flour types showed a bimodal distribution, except for the small-sized yellow pea flour. For both the pulse types, slightly more than 50% flour was approximately sizing 50 μm, 75 μm, and 100 μm for small, medium, and large settings, respectively. The chemical composition of the flour types remained practically the same for different-sized flours, fulfilling the objective of this current study. The damaged starch values for red lentil and yellow pea flour types increased with a decrease in flour particle size. Based on the Hausner’s ratios, the flowability of large-sized flour of red lentils could be described as passable; however, all the remaining five flour types were indicated as either poor or very poor. The findings of this study assist the millers to adapt yellow pea and red lentil milling technologies with minor modifications to the existing facilities. The study also helps in boosting the production of various baking products using pulse and wheat flour blends to enhance their nutritional quality.
Extraction Methods of Oils and Phytochemicals from Seeds and Their Environmental and Economic Impacts
Authors: Lavenburg Valerie M. , Rosentrater Kurt A. , Jung Stephanie
Published: October 2021

Over recent years, the food industry has striven to reduce waste, mostly because of rising awareness of the detrimental environmental impacts of food waste. While the edible oils market (mostly represented by soybean oil) is forecasted to reach 632 million tons by 2022, there is increasing interest to produce non-soybean, plant-based oils including, but not limited to, coconut, flaxseed and hemp seed. Expeller pressing and organic solvent extractions are common methods for oil extraction in the food industry. However, these two methods come with some concerns, such as lower yields for expeller pressing and environmental concerns for organic solvents. Meanwhile, supercritical CO2 and enzyme-assisted extractions are recognized as green alternatives, but their practicality and economic feasibility are questioned. Finding the right balance between oil extraction and phytochemical yields and environmental and economic impacts is challenging. This review explores the advantages and disadvantages of various extraction methods from an economic, environmental and practical standpoint. The novelty of this work is how it emphasizes the valorization of seed by-products, as well as the discussion on life cycle, environmental and techno-economic analyses of oil extraction methods.
Human-Altered Soils at an Archeological Site of the Bronze Age: The Tyater-Araslanovo-II Settlement, Southern Cis-Ural Region, Russia
Authors: Suleymanov Ruslan , Obydennova Gulnara , Kungurtsev Andrey , Atnabaev Niyaz , Komissarov Mikhail , Gusarov Artyom , Adelmurzina Ilgiza , Suleymanov Azamat , Abakumov Evgeny
Published: October 2021

This paper presents the results of studying the soils at the archeological site of the Tyater-Araslanovo-II settlement located in the Republic of Bashkortostan, eastern European Russia. The settlement functioned in the 15th–12th centuries BCE (the Late Bronze Age). We compared the soil properties at four sites in the study area: archeological (1), buried (2), affected by long pyrogenic exposure (3), and background site (4). In soil samples, the total carbon content, the fractional composition of humus and organic matter characteristics, alkaline hydrolyzable nitrogen, total phosphorus, mobile phosphorus, potassium, absorbed calcium and magnesium, pH, particle size distribution, basal soil respiration, and optical density were estimated. The study results showed the anthropogenic impact on the archeological site’s soils. The newly formed AU horizon at the archeological site (1), affected by the cattle summer camp, was richer in soil nutrients and agrochemical properties, namely, the content of exchangeable and gross forms of phosphorus, alkaline hydrolyzable nitrogen, and exchange cations of the soil absorbing complex compared to the reference soil (4). For the pyrogenic layer (AU[hh]pyr) from the ancient furnace (fireplace) (3), the mobile and total forms of phosphorus were several times higher than those in the reference soil (4) but inferior regarding other agrochemical parameters. Thus, the activities of ancient people (especially cattle breeding) greatly influenced the properties of the soil.
Precious Items Piling up Like Mountains: Buddhist Art Production via Fundraising Campaigns in Late Koryŏ Korea (918–1392)
Authors: Stiller Maya
Published: October 2021

Considering visual culture alongside written source material, this article uncovers the socioeconomic aspect of Korean Buddhist monastic life, which has been a marginalized field of research. Arguing against the idea of an “other-worldly” Buddhism, the article specifically discusses the ways in which Buddhist monasteries conducted fundraising activities in late Koryŏ period (918–1392 CE) Korea. Via fundraising strategies, which targeted wealthy aristocrats as well as the commoner population, Buddhist monks managed the production and maintenance of Buddhist material culture, such as the construction of shrines, the casting of precious sculptures, and the carving of thousands of woodblocks used for the printing of sacred Buddhist scriptures. While the scholarship on Koryŏ Buddhism has traditionally focused on meditation, doctrine, state sponsored rituals, and temples’ relationships with the royal court, this study expands the field by showing that economic activities were salient features of Koryŏ Buddhism “on the ground.” By initiating and overseeing fundraising activities, Buddhist manager-monks not only gained merit, but also maintained the presence and physical appearance of Buddhist temples, which constitute the framework of Buddhist ritual and practice.
Black and Blue: Black Women, ‘Law and Order,’ and the Church’s Silence on Police Violence
Authors: Mingo AnneMarie
Published: October 2021

During the mid-twentieth century, many southern White religious leaders proudly championed police brutality and other forms of state-sanctioned violence against Black citizens. In Martin Luther King, Jr’s Letter from Birmingham Jail, he defends direct-action non-violent protests as he responds to criticisms and offers his own critique of the clergymen who gave commendations to “the police force for keeping ‘order’ and ‘preventing violence,’” while ignoring the “ugly and inhumane treatment” that the police exerted on non-violent Black protestors who sought to stand up for their rights. King intentionally includes examples of violence against older Black women and girls in his critique. In this article, the historical grounding in King’s critique is expanded to reflect longstanding support of police violence in White communities and a form of sanction through silence in Black communities centered around communal survival in the face of violent White power structures. This article highlights religious communities which ignored at best and sanctioned at worst police violence against Black women and girls and identifies the need for change in the twenty-first century. Ultimately, it calls for leaders to be in proximate location to police violence so when they see it, they can be moved ethically to address it.
Spirituality and Spiritual Care among Ethnic Chinese Residing in England: Implications for Nursing
Authors: Niu Yanping , McSherry Wilfred , Partridge Martin
Published: October 2021

(1) Background: There is a lack of understanding of how spirituality is understood among ethnic Chinese living outside of China. The aim of this investigation was to gain insight into the meaning of spirituality and spiritual care among ethnic Chinese residing in England. (2) Methods: This study employed a grounded theory method. (3) Results: A core category called “seeking a meaningful life” emerged, comprising six categories: “motivation”, “support”, “maintaining standard values”, “achieving a meaningful life”, “relationships” and “perceptions of spirituality”. The core category included a three-stage process influenced by two factors: relationships with others and perceptions of spirituality. In motivated or supported situations of suffering and illness, ethnic Chinese usually follow principles of their Chinese tradition in seeking meaning for a satisfied spiritual life. This process is impacted by their relationships with others and view of spirituality. (4) Conclusions: Participants’ understanding of spirituality and spiritual care was related to seeking meaning and purpose in life. Nurses could incorporate the newly developed life meaning processes into their practice. This could be achieved by culturally explaining suffering and focusing on the significance of physical illness for Chinese people. This would ensure their spiritual care practice delivers culturally competent care for ethnic Chinese. Educators could also incorporate this process within their teaching materials so that this aspect of spiritual care is addressed for this specific group.
Radical Islam and Insurgency in Northern Nigeria: Tensions and Challenges
Authors: Onakuse Stephen , Jatula Victor
Published: October 2021

Located within a broad appraisal of Nigeria’s nascent democracy, this paper examined the roots and triggers of radical Islam and religious extremism in Northern Nigeria. It also investigated its implication in the region through the lenses of religion and politics. Since 1804, a tradition of jihadist Islam in the north, introduced by Sheikh Uthman dan Fodio, has shaped not only the politics of the region but has festered into modern-day insurgency. This radicalism enthroned an intolerant, anti-Western and violent Islamic ideology used against minorities within and against other religions, ethno-regional groups, and political blocs in Nigeria. What exactly are the triggers of religious violence in today’s Northern Nigeria? Furthermore, if any, what are the implications for this region? Drawing on archival materials and secondary sources, findings reveal deep-seated, anti-southern sentiments in the north, complicated by religious, cultural, and economic suspicions, whipped up at political intersections. Evidence also indicates significant leadership failures. This internal complexity holds back Northern Nigeria’s overall economic and social modernisation pace. This paper recommends state-sponsored awareness campaigns that emphasise diversity, integration and unity. To overcome insurgency, politics must deliver dividends of democracy to all. Governance must become a means to economic ends and not an end in itself.
The Socio-Ethical Outlook on the Concept of Human Aggression and a Concept of Good Society—Towards New Socio-Religious Approaches for Human Morality—Theoretical Debate
Authors: Szot Leon , Niewiadomska Iwona
Published: October 2021

The authors analyze the concept of human aggression and the concept of a good society as they are both perceived in the sociological and interdisciplinary domains. They debate the issue of human aggression observed in contemporary societies, which hampers general social development worldwide, the expedition of socio-religious morality, and the positive action of good behavior. Both concepts have a long record of sociological research, although the exploration of the concept of a good society was most popular in the sociological research of the 1970s. At present, a substantial increase in the levels of human aggression among and particularly towards religious communities in societies during peacetime is seen as the most complex impediment to the preservation of good societies, regardless of their structural endeavors. The authors analyze the available data, including empirical data, concerning their researched theme to identify a theoretical framework of linkages that would allow them to perform further research and take stock of the scientific efforts made so far to perceive morality as a platform connecting good society models with the potential for the reduction in aggression.
Effect of Structural Funds on Housing Market Sustainability Development—Correlation, Regression and Wavelet Coherence Analysis
Authors: Mach Łukasz , Bedrunka Karina , Kuczuk Anna , Szewczuk-Stępień Marzena
Published: October 2021

Effective acquisition of funds, including European Union (EU) funds, designated for example, creating economic and social processes, may have a real impact on the elimination of the negative outcomes of the current position of the EU on the global scale. The aim of the research is to indicate the impact of spending funds from the Regional Operational Program of the Opolskie Voivodeship 2014–2020 (ROP OV) on a key macroeconomic area of the economy, i.e., the housing development sector in the region. The practical aim is to formulate recommendations and solutions that can offer guidelines for more effective spending of EU funds and their effect on the macroeconomic dimensions of the economy. The article proposes an innovative approach to linking EU payments in the region with the real estate market. The results of the research and the analyses made on this basis showed a positive impact of the payments made from the ROP OV on selected macroeconomic indicators, i.e., the number of permits issued for the construction of new apartments and the number of currently implemented housing investments. The obtained results should be used in the decision-making process at the level of regional and national authorities responsible for the payment of EU funds. In this article, prior to the research process, a literature review was made. It covered various aspects of the evolution and development of research in the area of regional development. The research process was based on innovative methods of time variability analysis, correlation between the investigated determinants and coherence analysis for the studied dimensions. Data on payments from the ROP OV concern the years 2015–2020.
Impairment of Assets and Market Reaction during COVID-19 Pandemic on the Example of WSE
Authors: Lisicki Bartłomiej
Published: October 2021

The main task of the article is to examine the impact of the reported impairment of assets (IoA) on the market reaction of investors on the Warsaw Stock Exchange [WSE] in the crisis condition caused by the COVID-19 pandemic. There is a need to verify whether the disclosure of this information in the period of economic downturn will cause a similar negative reaction as in previous topics in this area. Research undertaken in this article helps identify the rules of behaviour (in the short term) whether the reaction of investors on updating the company’s assets in crisis conditions is different than in times of prosperity. The main hypothesis will be verified using the event study methodology. It allows to verify whether the upcoming information about IoA during the COVID-19 pandemic confirms an existence of statistically significant negative abnormal returns. Based on the 55 cases of current reports informing about IoA, which were submitted to the investors in the year 2020 and finally qualified for the research sample, I have not observed statistically significant negative abnormal returns on the adjacent days. The results are different from those obtained by researchers who study the market reaction to the IoA under non-crisis conditions of the economy.
Influence of Varying Solar Zenith Angles on Land Surface Phenology Derived from Vegetation Indices: A Case Study in the Harvard Forest
Authors: Li Yang , Jiao Ziti , Zhao Kaiguang , Dong Yadong , Zhou Yuyu , Zeng Yelu , Xu Haiqing , Zhang Xiaoning , Hu Tongxi , Cui Lei
Published: October 2021

Vegetation indices are widely used to derive land surface phenology (LSP). However, due to inconsistent illumination geometries, reflectance varies with solar zenith angles (SZA), which in turn affects the vegetation indices, and thus the derived LSP. To examine the SZA effect on LSP, the MODIS bidirectional reflectance distribution function (BRDF) product and a BRDF model were employed to derive LSPs under several constant SZAs (i.e., 0°, 15°, 30°, 45°, and 60°) in the Harvard Forest, Massachusetts, USA. The LSPs derived under varying SZAs from the MODIS nadir BRDF-adjusted reflectance (NBAR) and MODIS vegetation index products were used as baselines. The results show that with increasing SZA, NDVI increases but EVI decreases. The magnitude of SZA-induced NDVI/EVI changes suggests that EVI is more sensitive to varying SZAs than NDVI. NDVI and EVI are comparable in deriving the start of season (SOS), but EVI is more accurate when deriving the end of season (EOS). Specifically, NDVI/EVI-derived SOSs are relatively close to those derived from ground measurements, with an absolute mean difference of 8.01 days for NDVI-derived SOSs and 9.07 days for EVI-derived SOSs over ten years. However, a considerable lag exists for EOSs derived from vegetation indices, especially from the NDVI time series, with an absolute mean difference of 14.67 days relative to that derived from ground measurements. The SOSs derived from NDVI time series are generally earlier, while those from EVI time series are delayed. In contrast, the EOSs derived from NDVI time series are delayed; those derived from the simulated EVI time series under a fixed illumination geometry are also delayed, but those derived from the products with varying illumination geometries (i.e., MODIS NBAR product and MODIS vegetation index product) are advanced. LSPs derived from varying illumination geometries could lead to a difference spanning from a few days to a month in this case study, which highlights the importance of normalizing the illumination geometry when deriving LSP from NDVI/EVI time series.
Building Cultural Heritage Resilience through Remote Sensing: An Integrated Approach Using Multi-Temporal Site Monitoring, Datafication, and Web-GL Visualization
Authors: Lercari Nicola , Jaffke Denise , Campiani Arianna , Guillem Anaïs , McAvoy Scott , Delgado Gerardo Jiménez , Bevk Neeb Alexandra
Published: October 2021

In the American West, wildfires and earthquakes are increasingly threatening the archaeological, historical, and tribal resources that define the collective identity and connection with the past for millions of Americans. The loss of said resources diminishes societal understanding of the role cultural heritage plays in shaping our present and future. This paper examines the viability of employing stationary and SLAM-based terrestrial laser scanning, close-range photogrammetry, automated surface change detection, GIS, and WebGL visualization techniques to enhance the preservation of cultural resources in California. Our datafication approach combines multi-temporal remote sensing monitoring of historic features with legacy data and collaborative visualization to document and evaluate how environmental threats affect built heritage. We tested our methodology in response to recent environmental threats from wildfire and earthquakes at Bodie, an iconic Gold Rush-era boom town located on the California and Nevada border. Our multi-scale results show that the proposed approach effectively integrates highly accurate 3D snapshots of Bodie’s historic buildings before/after disturbance, or post-restoration, with surface change detection and online collaborative visualization of 3D geospatial data to monitor and preserve important cultural resources at the site. This study concludes that the proposed workflow enhances the monitoring of at-risk California’s cultural heritage and makes a call to action to employ remote sensing as a pathway to advanced planning.
Detection of Abnormal Vibration Dampers on Transmission Lines in UAV Remote Sensing Images with PMA-YOLO
Authors: Bao Wenxia , Ren Yangxun , Wang Nian , Hu Gensheng , Yang Xianjun
Published: October 2021

The accurate detection and timely replacement of abnormal vibration dampers on transmission lines are critical for the safe and stable operation of power systems. Recently, unmanned aerial vehicles (UAVs) have become widely used to inspect transmission lines. In this paper, we constructed a data set of abnormal vibration dampers (DAVDs) on transmission lines in images obtained by UAVs. There are four types of vibration dampers in this data set, and each vibration damper may be rusty, defective, or normal. The challenges in the detection of abnormal vibration dampers on transmission lines in the images captured by UAVs were as following: the images had a high resolution as well as the objects of vibration dampers were relatively small and sparsely distributed, and the backgrounds of cross stage partial networks of the images were complex due to the fact that the transmission lines were erected in a variety of outdoor environments. Existing methods of ground-based object detection significantly reduced the accuracy when dealing with complex backgrounds and small objects of abnormal vibration dampers detection. To address these issues, we proposed an end-to-end parallel mixed attention You Only Look Once (PMA-YOLO) network to improve the detection performance for abnormal vibration dampers. The parallel mixed attention (PMA) module was introduced and integrated into the YOLOv4 network. This module combines a channel attention block and a spatial attention block, and the convolution results of the input feature maps in parallel, allowing the network to pay more attention to critical regions of abnormal vibration dampers in complex background images. Meanwhile, in view of the problem that abnormal vibration dampers are prone to missing detections, we analyzed the scale and ratio of the ground truth boxes and used the K-means algorithm to re-cluster new anchors for abnormal vibration dampers in images. In addition, we introduced a multi-stage transfer learning strategy to improve the efficiency of the original training method and prevent overfitting by the network. The experimental results showed that the mAP@0.5 for PMA-YOLO in the detection of abnormal vibration dampers reached 93.8% on the test set of DAVD, 3.5% higher than that of YOLOv4. When the multi-stage transfer learning strategy was used, the mAP@0.5 was improved by a further 0.2%.
SAR-Based Flood Monitoring for Flatland with Frequently Fluctuating Water Surfaces: Proposal for the Normalized Backscatter Amplitude Difference Index (NoBADI)
Authors: Nagai Hiroto , Abe Takahiro , Ohki Masato
Published: October 2021

Space-based synthetic aperture radar (SAR) is a powerful tool for monitoring flood conditions over large areas without the influence of clouds and daylight. Permanent water surfaces can be excluded by comparing SAR images with pre-flood images, but fluctuating water surfaces, such as those found in flat wetlands, introduce uncertainty into flood mapping results. In order to reduce this uncertainty, a simple method called Normalized Backscatter Amplitude Difference Index (NoBADI) is proposed in this study. The NoBADI is calculated from a post-flood SAR image of backscatter amplitude and multiple images on non-flooding conditions. Preliminary analysis conducted in the US state of Florida, which was affected by Hurricane Irma in September 2017, shows that surfaces frequently covered by water (more than 20% of available data) have been successfully excluded by means of C-/L-band SAR (HH, HV, VV, and VH polarizations). Although a simple comparison of pre-flood and post-flood images is greatly affected by the spatial distribution of the water surface in the pre-flood image, the NoBADI method reduces the uncertainty of the reference water surface. This advantage will contribute in making quicker decisions during crisis management.
Source Model and Simulated Strong Ground Motion of the 2021 Yangbi, China Shallow Earthquake Constrained by InSAR Observations
Authors: Wang Yongzhe , Chen Kun , Shi Ying , Zhang Xu , Chen Shi , Li Ping’en , Lu Donghua
Published: October 2021

On 21 May 2021, an Mw 6.1 earthquake, causing considerable seismic damage, occurred in Yangbi County, Yunnan Province of China. To better understand the surface deformation pattern, source characteristics, seismic effect on nearby faults, and strong ground motion, we processed the ascending and descending SAR images using the interferometric synthetic aperture radar (InSAR) technique to capture the radar line-of-sight (LOS) directional and 2.5-dimensional deformation. The source model was inverted from the LOS deformation observations. We further analyzed the Coulomb failure stress (CFS) transfer and peak ground acceleration (PGA) simulation based on the preferred source model. The results suggest that the 2021 Yangbi earthquake was dextral faulting with the maximum slip of 0.9 m on an unknown blind shallow fault, and the total geodetic moment was 1.4 × 1018 Nm (Mw 6.06). Comprehensive analysis of the CFS transfer and geological tectonics suggests that the Dian–Xibei pull-apart basin is still suffering high seismic hazards. The PGA result demonstrates that the seismic intensity of this event reached up to VIII. The entire process from InSAR deformation to source modeling and strong ground motion simulation suggests that the InSAR technique will play an important role in the assessment of earthquake disasters in the case of the shortening of the SAR imaging interval.
Fusing Retrievals of High Resolution Aerosol Optical Depth from Landsat-8 and Sentinel-2 Observations over Urban Areas
Authors: Lin Hao , Li Siwei , Xing Jia , Yang Jie , Wang Qingxin , Dong Lechao , Zeng Xiaoyue
Published: October 2021

Recent studies have shown that the high-resolution satellite Landsat-8 has the capability to retrieve aerosol optical depth (AOD) over urban areas at a 30 m spatial resolution. However, its long revisiting time and narrow swath limit the coverage and frequency of the high resolution AOD observations. With the increasing number of Earth observation satellites launched in recent years, combining the observations of multiple satellites can provide higher temporal-spatial coverage. In this study, a fusing retrieval algorithm is developed to retrieve high-resolution (30 m) aerosols over urban areas from Landsat-8 and Sentinel-2 A/B satellite measurements. The new fusing algorithm was tested and evaluated over Beijing city and its surrounding area in China. The validation results show that the retrieved AODs show a high level of agreement with the local urban ground-based Aerosol Robotic Network (AERONET) AOD measurements, with an overall high coefficient of determination (R2) of 0.905 and small root mean square error (RMSE) of 0.119. Compared with the operational AOD products processed by the Landsat-8 Surface Reflectance Code (LaSRC-AOD), Sentinel Radiative Transfer Atmospheric Correction code (SEN2COR-AOD), and MODIS Collection 6 AOD (MOD04) products, the AOD retrieved from the new fusing algorithm based on the Landsat-8 and Sentinel-2 A/B observations exhibits an overall higher accuracy and better performance in spatial continuity over the complex urban area. Moreover, the temporal resolution of the high spatial resolution AOD observations was greatly improved (from 16/10/10 days to about two to four days over globe land in theory under cloud-free conditions) and the daily spatial coverage was increased by two to three times compared to the coverage gained using a single sensor.
Leaf Surface Reflectance Does Not Affect Biophysical Traits Modelling from VIS-NIR Spectra in Plants with Sparsely Distributed Trichomes
Authors: Neuwirthová Eva , Lhotáková Zuzana , Lukeš Petr , Albrechtová Jana
Published: October 2021

In this study, we examine leaf reflectance as the main optical property used in remote sensing of vegetation. The total leaf reflectance consists of two main components: a diffuse component, originating from the leaf interior, and a component reflected directly from the leaf surface. The latter contains specular (mirror-like) reflectance (SR) and surface particle scattering, driven by the surface roughness. Our study aimed to (1) reveal the effects of key leaf structural traits on SR in 400–2500 nm, and (2) compare the performance of PLSR models of leaf biophysical properties based on the total reflectance and SR removal reflectance. Four Arabidopsis thaliana structural surface mutants and six Hieracium species differing in trichome properties were studied. PCA did not reveal any systematic effect of trichome density, length, and morphology on SR. Therefore, the results do not support the hypothesis that leaves with denser and longer trichomes have lower SR and higher total reflectance than the smooth leaves. SR removal did not remarkably improve PLSR models of biophysical traits (up to 2% of RMSE). Thus, in herbaceous dorsiventral leaves with relatively sparse trichomes of various morphology and without apparent waxy surface, we cannot confirm that SR removal significantly improves biophysical trait prediction.
Monitoring the Severity of Pantana phyllostachysae Chao on Bamboo Using Leaf Hyperspectral Data
Authors: Huang Xuying , Xu Zhanghua , Yang Xu , Shi Jingming , Hu Xinyu , Ju Weimin
Published: October 2021

Effectively monitoring Pantana phyllostachysae Chao (PPC) is essential for the sustainable development of the bamboo industry. However, the morphological similarity between damaged and off-year bamboo imposes challenges in the monitoring. The knowledge on whether the severity of this pest could be effectively monitored by using remote sensing methods is very limited. To fill this gap, this study aimed to identify the PPC damage of moso bamboo leaves using hyperspectral data. Specifically, we investigated differences in relative chlorophyll content (RCC), leaf water content (LWC), leaf nitrogen content (LNC), and hyperspectral spectrum among healthy, damaged (mildly damage, moderately damage, severely damage), and off-year bamboo leaves. Then, the hyperspectral indices sensitive to pest damage were selected by recursive feature elimination (RFE). The PPC damage identification model was constructed using the light gradient boosting machine (LightGBM) algorithm. We designed two different scenarios, without (A) and with (B) off-year samples, to evaluate the impact of off-year leaves on identification results. The RCC, the LWC, and the LNC of damaged leaves generally showed clear declined trends with the deterioration of damaged severity. The RCC and the LNC of off-year leaves were significantly lower than those of healthy and damaged leaves, whereas the LWC of off-leaves was significantly different from that of damaged leaves. The pest infestation caused noticeable distortion of leaf spectrum, increases in red and shortwave infrared bands, and decreases in green and near-infrared bands. The magnitude of reflectance change increased with the pest severity. The reflectance of off-year leaves in visible and near-infrared regions was distinguishably higher than that of healthy and damaged leaves. The overall accuracy (OA) of the constructed model for the identification of leaves with different degrees of damage severity reached 81.51%. When off-year, healthy, and damaged leaves were lumped together, the OA of the constructed model decreased by 5%. About half of the off-year leaf samples were misclassified into the damaged group. The identification of off-year leaves is a challenge for monitoring PPC damage using hyperspectral data. These results can provide practical guidance for monitoring PPC using remote sensing methods.
EFM-Net: Feature Extraction and Filtration with Mask Improvement Network for Object Detection in Remote Sensing Images
Authors: Wang Yu , Jia Yannan , Gu Lize
Published: October 2021

Object detection is an essential task in computer vision. Many methods have made significant progress in ordinary object detection. Due to the particularity of remote sensing images, the detection target is tiny, the background is messy, dense, and has mutual occlusion, which makes the general detection method challenging to apply to remote sensing images. For these problems, we propose a new detection framework feature extraction and filtration method with a mask improvement network (EFM-Net) to enhance object detection ability. In EFM-Net, we designed a multi-branched feature extraction (MBFE) module to better capture the information in the feature graph. In order to suppress the background interference, we designed a background filtering module based on attention mechanisms to enhance the attention of objects. Finally, we proposed a mask generate the boundary improvement method to make the network more robust to occlusion detection. We tested the DOTA v1.0, NWPU VHR-10, and UCAS-AOD datasets, and the experimental results show that our method has excellent effects.
Assessing the Responses of Aviation-Related SO2 and NO2 Emissions to COVID-19 Lockdown Regulations in South Africa
Authors: Shikwambana Lerato , Kganyago Mahlatse
Published: October 2021

Aircraft emit harmful substances, such as carbon dioxide (CO2), water vapour (H2O), nitrogen oxides (NOx), sulphur oxides (SOx), particulates, and other trace compounds. These emissions degrade air quality and can deteriorate human health and negatively impact climate change. Airports are the nucleus of the ground and low-altitude emissions from aircraft during approach, landing, take-off, and taxi. During the global lockdown due to the COVID-19 pandemic, tight restrictions of the movement were imposed, leading to temporary closures of airports globally. In this study, we look at the variability of emissions at two major airports in South Africa, namely the OR Tambo international airport (FAOR) and the Cape Town international airport (FACT). Trend analysis of aircraft movements, i.e., departures and arrivals, showed a sharp decline at the two airports coinciding with the lockdowns to prevent the spread of the COVID-19. Consequently, a decrease in NO2 emissions by 70.45% (12.6 × 10−5 mol/m2) and 64.58% (11.6 × 10−5 mol/m2) at FAOR and FACT were observed, respectively. A noticeable SO2 emission decline was also observed, particularly over FAOR during the lockdown period in South Africa. Overall, this study observed that the global lockdown regulations had a positive impact on the air quality, causing a brief decline in emissions from commercial aviation at the South African major airports.
High-Resolution Cooperate Density-Integrated Inversion Method of Airborne Gravity and Its Gradient Data
Authors: Ma Guoqing , Gao Tong , Li Lili , Wang Taihan , Niu Runxin , Li Xinwei
Published: October 2021

Airborne (or satellite) gravity measurement is a commonly used remote sensing method to obtain the underground density distribution. Airborne gravity gradiometry data have a higher horizontal resolution to shallower causative sources than airborne gravity anomaly, so joint exploration of airborne gravity and its gradient data can simultaneously obtain the anomaly feature of sources with different depths. The most commonly used joint inversion method of gravity and its gradient data is the data combined method, which is to combine all the components into a data matrix as mutual constraints to reduce ambiguity and non-uniqueness. In order to obtain higher resolution results, we proposed a cooperate density-integrated inversion method of airborne gravity and its gradient data, which firstly carried out the joint inversion using cross-gradient constraints to obtain two density structures, and then fused two recovered models into a result through Fourier transform; finally, data combined joint inversion of airborne gravity, and gradient data were reperformed to achieve high-resolution density result using fused density results as a reference model. Compared to the data combined joint inversion method, the proposed cooperate density-integrated inversion method can obtain higher resolution and more accurate density distribution of shallow and deep bodies meanwhile. We also applied it to real data in the mining area of western Liaoning Province, China. The results showed that the depth of the skarn-type iron mine in the region is about 900–1300 m and gives a more specific distribution compared to the geological results, which provided reliable data for the next exploration plan.
Mapping Crop Rotation by Using Deeply Synergistic Optical and SAR Time Series
Authors: Liu Yiqing , Zhao Wenzhi , Chen Shuo , Ye Tao
Published: October 2021

Crop rotations, the farming practice of growing crops in sequential seasons, occupy a core position in agriculture management, showing a key influence on food security and agro-ecosystem sustainability. Despite the improvement in accuracy of identifying mono-agricultural crop distribution, crop rotation patterns remain poorly mapped. In this study, a hybrid convolutional neural network (CNN) and long short-term memory (LSTM) architecture, namely crop rotation mapping (CRM), were proposed to synergize the synthetic aperture radar (SAR) and optical time series in a rotational mapping task. The proposed end-to-end architecture had reasonable accuracies (i.e., accuracy > 0.85) in mapping crop rotation, which outperformed other state-of-the-art non-deep or deep-learning solutions. For some confusing rotation types, such as fallow-single rice and crayfish-single rice, CRM showed substantial improvements from traditional methods. Furthermore, the deeply synergistic SAR-optical, time-series data, with a corresponding attention mechanism, were effective in extracting crop rotation features, with an overall gain of accuracy of four points compared with ablation models. Therefore, our proposed method added wisdom to dynamic crop rotation mapping and yields important information for the agro-ecosystem management of the study area.
The Amber-Colored Liquid: A Review on the Color Standards, Methods of Detection, Issues and Recommendations
Authors: Hasnul Hadi Muhamad Haziq , Ker Pin Jern , Thiviyanathan Vimal A. , Tang Shirley Gee Hoon , Leong Yang Sing , Lee Hui Jing , Hannan Mahammad A. , Jamaludin Md. Zaini , Mahdi Mohd Adzir
Published: October 2021

For most natural or naturally-derived liquid products, their color reflects on their quality and occasionally affects customer preferences. To date, there are a few subjective and objective methods for color measurement which are currently utilized by various industries. Researchers are also improving these methods and inventing new methods, as color is proven to have the ability to provide various information on the condition and quality of the liquid. However, a review on the methods, especially for amber-colored liquid, has not been conducted yet. This paper presents a comprehensive review on the subjective and objective methods for color measurement of amber-colored liquids. The pros and cons of the measurement methods, the effects of the color on customer preferences, and the international industry standards on color measurements are reviewed and discussed. In addition, this study elaborates on the issues and challenges related to the color measurement techniques as well as recommendations for future research. This review demonstrates that the existing color measurement technique can determine the color according to the standards and color scales. However, the efforts toward minimizing the complexity of the hardware while maximizing the signal processing through advanced computation are still lacking. Therefore, through this critical review, this review can hopefully intensify the efforts toward finding an optimized method or technique for color measurement of liquids and thus expedite the development of a portable device that can measure color accurately.
Numerical Modelling of a Distributed Acoustic Sensor Based on Ultra-Low Loss-Enhanced Backscattering Fibers
Authors: van Putten Lieke Dorine , Masoudi Ali , Snook James , Brambilla Gilberto
Published: October 2021

In this study, a distributed acoustic sensor (DAS) was numerically modeled based on the non-ideal optical components with their noises and imperfections. This model is used to compare the response of DAS systems to standard single-mode fibers and ultra-low loss-enhanced backscattering (ULEB) fibers, a fiber with an array of high reflective points equally spaced along its length. It is shown that using ULEB fibers with highly reflective points improves the signal-to-noise ratio and linearity of the measurement, compared with the measurement based on standard single-mode fibers.