bluuebunny/crossref_metadata_2025 huggingface dataset:
Sustainable Biochar and/or Melatonin Improve Salinity Tolerance in Borage Plants by Modulating Osmotic Adjustment, Antioxidants, and Ion Homeostasis
Authors: Farouk Saad , AL-Huqail Arwa Abdulkreem
Published: March 2022

Salinity is persistently a decisive feature confining agricultural sustainability and food security in arid and semi-arid regions. Biochar (Bi) has been advocated as a means of lessening climate changes by sequestering carbon, concurrently supplying energy and rising crop productivity under normal or stressful conditions. Melatonin (Mt) has been shown to mediate numerous biochemical pathways and play important roles in mitigating multi-stress factors. However, their integrated roles in mitigating salt toxicity remain largely inexpressible. A completely randomized design was conducted to realize the remediation potential of Bi and/or Mt in attenuation salinity injury on borage plants by evaluating its effects on growth, water status, osmotic adjustment, antioxidant capacity, ions, and finally the yield. Salinity stress significantly decreased the plant growth and attributed yield when compared with non-salinized control plants. The depression effect of salinity on borage productivity was associated with the reduction in photosynthetic pigment and ascorbic acid (AsA) concentrations, potassium (K+) percentage, K+-translocation, and potassium/sodium ratio as well as catalase (CAT) activity. Additionally, borage plants’ water status was disrupted by salinity through decreasing water content (WC), relative water content (RWC), and water retention capacity (WTC), as well as water potential (Ψw), osmotic potential (Ψs), and turgor potential (Ψp). Moreover, salinity stress evoked oxidative bursts via hyper-accumulation of hydrogen peroxide (H2O2) and malondialdehyde (MDA), as well as protein carbonyl, which is associated with membrane dysfunction. The oxidative burst was connected with the hyper-accumulation of sodium (Na+) and chloride (Cl−) in plant tissues, coupled with osmolytes’ accumulation and accelerating plants’ osmotic adjustment (OA) capacity. The addition of Bi and/or Mt had a positive effect in mitigating salinity on borage plants by reducing Cl−, Na+, and Na+-translocation, and oxidative biomarkers as well as Ψw, Ψs, and Ψp. Moreover, Bi and/or Mt addition to salt-affected plants increased plant growth and yield by improving plant water status and OA capacity associated with the activation of antioxidant capacity and osmolytes accumulation as well as increased photosynthetic pigments, K+, and K+/Na+ ratio. Considering these observations, Bi and/or Mt can be used as a promising approach for enhancing the productivity of salt-affected borage plants due to their roles in sustaining water relations, rising solutes synthesis, progressing OA, improving redox homeostasis, and antioxidant aptitude.
Bioactive Low Molecular Weight Keratin Hydrolysates for Improving Skin Wound Healing
Authors: Olariu Laura , Dumitriu Brindusa Georgiana , Gaidau Carmen , Stanca Maria , Tanase Luiza Mariana , Ene Manuela Diana , Stanculescu Ioana-Rodica , Tablet Cristina
Published: March 2022

Keratin biomaterials with high molecular weights were intensively investigated but few are marketed due to complex methods of extraction and preparation and limited understanding of their influence on cells behavior. In this context the aim of this research was to elucidate decisive molecular factors for skin homeostasis restoration induced by two low molecular weight keratin hydrolysates extracted and conditioned through a simple and green method. Two keratin hydrolysates with molecular weights of 3758 and 12,400 Da were physico-chemically characterized and their structure was assessed by circular dichroism (CD) and FTIR spectroscopy in view of bioactive potential identification. Other investigations were focused on several molecular factors: α1, α2 and β1 integrin mediated signals, cell cycle progression in pro-inflammatory conditions (TNFα/LPS stimulated keratinocytes and fibroblasts) and ICAM-1/VCAM-1 inhibition in human vascular endothelial cells. Flow cytometry techniques demonstrated a distinctive pattern of efficacy: keratin hydrolysates over-expressed α1 and α2 subunits, responsible for tight bounds between fibroblasts and collagen or laminin 1; both actives stimulated the epidermal turn-over and inhibited VCAM over-expression in pro-inflammatory conditions associated with bacterial infections. Our results offer mechanistic insights in wound healing signaling factors modulated by the two low molecular weight keratin hydrolysates which still preserve bioactive secondary structure.
Sidechain Metallopolymers with Precisely Controlled Structures: Synthesis and Application in Catalysis
Authors: Qu Rui , Suo Hongyi , Gu Yanan , Weng Yunxuan , Qin Yusheng
Published: March 2022

Inspired by the cooperative multi-metallic activation in metalloenzyme catalysis, artificial enzymes as multi-metallic catalysts have been developed for improved kinetics and higher selectivity. Previous models about multi-metallic catalysts, such as cross-linked polymer-supported catalysts, failed to precisely control the number and location of their active sites, leading to low activity and selectivity. In recent years, metallopolymers with metals in the sidechain, also named as sidechain metallopolymers (SMPs), have attracted much attention because of their combination of the catalytic, magnetic, and electronic properties of metals with desirable mechanical and processing properties of polymeric backbones. Living and controlled polymerization techniques provide access to SMPs with precisely controlled structures, for example, controlled degree of polymerization (DP) and molecular weight dispersity (Đ), which may have excellent performance as multi-metallic catalysts in a variety of catalytic reactions. This review will cover the recent advances about SMPs, especially on their synthesis and application in catalysis. These tailor-made SMPs with metallic catalytic centers can precisely control the number and location of their active sites, exhibiting high catalytic efficiency.
Effect of Active Bonding Application after Selective Dentin Etching on the Immediate and Long-Term Bond Strength of Two Universal Adhesives to Dentin
Authors: Hardan Louis , Orsini Giovanna , Bourgi Rim , Cuevas-Suárez Carlos , Nicastro Marco , Lazarescu Florin , Filtchev Dimitar , Cornejo-Ríos Elizabeth , Zamarripa-Calderón Juan , Sokolowski Krzysztof , Lukomska-Szymanska Monika
Published: March 2022

The objective was to evaluate the influence of active bonding applications (ABA) for different time intervals after selective dentin etching (SDE) for 3 s on the microtensile bond strength (μTBS) to dentin of two universal adhesive systems (UAs): one containing 2-hydroxyethyl methacrylate (HEMA) (Scotchbond Universal, SBU), and one that was HEMA-free (Prime&Bond Universal, PBU). Dentin bovine specimens were divided into four groups: self-etch as control (SE), SDE + ABA for 15 s (SDE15), SDE + ABA for 20 s (SDE20), and SDE + ABA for 25 s (SDE25). The μTBS test was performed after a water storage of 24 h and 6 months. Scanning electron microscopy (SEM) was used in order to examine the resin–dentin interface. For the PBU, the µTBS was significantly influenced only by the aging factor (p < 0.026). A statistically significant decrease in the µTBS after 6 months of aging was observed only for the SDE15 group. For SBU, µTBS was significantly influenced by the protocol application and the aging time (p ≤ 0.041). The groups SDE15, SDE20, and SDE25 achieved statistically significant higher values (after 24 h and 6 months). No considerable variances were noticed in the homogeneity and continuity of the hybrid layer (HL) among the groups. In conclusion, SDE and ABA improved the µTBS only of a HEMA-containing universal adhesive.
3D Woven Textile Structural Polymer Composites: Effect of Resin Processing Parameters on Mechanical Performance
Authors: Mishra Rajesh Kumar , Petru Michal , Behera Bijoya Kumar , Behera Promoda Kumar
Published: March 2022

This work presents the manufacture of polymer composites using 3D woven structures (orthogonal, angle interlock and warp interlock) with glass multifilament tows and epoxy as the resin. The mechanical properties were analyzed by varying the processing parameters, namely, add-on percentage, amount of hardener, curing time, curing temperature and molding pressure, at four different levels during the composite fabrication for three different 3D woven structures. The mechanical properties of composites are affected by resin infusion or resin impregnation. Resin infusion depends on many processing conditions (temperature, pressure, viscosity and molding time), the structure of the reinforcement and the compatibility of the resin with the reinforcement. The samples were tested for tensile strength, tensile modulus, impact resistance and flexural strength. Optimal process parameters were identified for different 3D-woven-structure-based composites for obtaining optimal results for tensile strength, tensile modulus, impact resistance and flexural strength. The tensile strength, elongation at break and tensile modulus were found to be at a maximum for the angle interlock structure among the various 3D woven composites. A composition of 55% matrix (including 12% of hardener added) and 45% fiber were found to be optimal for the tensile and impact performance of 3D woven glass–epoxy composites. A curing temperature of about 140 °C seemed to be optimal for glass–epoxy composites. Increasing the molding pressure up to 12 bar helped with better penetration of the resin, resulting in higher tensile strength, modulus and impact performance. The optimal conditions for the best flexural performance in 3D woven glass–epoxy composites were 12% hardener, 140 °C curing temperature, 900 s curing time and 12 bar molding pressure.
Nanoparticles Loaded Thermoresponsive In Situ Gel for Ocular Antibiotic Delivery against Bacterial Keratitis
Authors: Abbas Muhammad Naseer , Khan Saeed Ahmad , Sadozai Sajid Khan , Khalil Islam A. , Anter Asem , Fouly Marwa El , Osman Ahmed H. , Kazi Mohsin
Published: March 2022

Antibiotics delivered through conventional dosage against ophthalmic infections show lower therapeutic efficacy due to their low residence time. Therefore, there is a great need to design and develop novel dosage forms that would increase the ocular residence time of antibiotics at the site of infection. This study describes the development of nanoparticles laden in situ gelling solution, intended to sustain antibiotic release for improved therapeutic efficiency. Oxytetracycline-loaded gelatin-polyacrylic acid nanoparticles were prepared and incorporated in poloxamer-N407 solution. The rheological properties of the system were studied concerning time and temperature. Moreover, in vivo biocompatibility of the system was ascertained using the Draize test and histological studies. Finally, the optimized formulation was evaluated for in vitro antibacterial activity against one of the most common keratitis causing bacteria, Pseudomonas aeruginosa. Additionally, the in vivo efficacy was evaluated on the rabbit’s eye conjunctivitis model. The formulation showed a sustained effect against keratitis; furthermore, the antibacterial activity was comparable with the commercial product.
Tribological Properties of Polyamide 46/Graphene Nanocomposites
Authors: Lee Pyoung-Chan , Kim Su Young , Ko Youn Ki , Ha Jin Uk , Jeoung Sun Kyoung , Shin Donghyeok , Kim Jung Hoon , Kim Myeong-Gi
Published: March 2022

Polyamide 46 (PA46) is used in various automotive parts because of its excellent heat resistance and mechanical properties. This study aims to improve the frictional properties of PA46 using the lubricating ability of graphene. Nanocomposites are prepared via two mixing methods: Graphene powder is compounded directly with PA46 pellets through a twin-screw extruder, or PA46 powder is added to graphene dispersion for self-adsorption, and subsequently, it is dried and compounded with PA46 through the twin-screw extruder. Application of the nanocomposite in the friction field is evaluated via the pin-on-disk method. The coefficient of friction of the nanocomposite prepared by self-adsorption is lower than that of the nanocomposite prepared by direct compounding. The mechanical properties of the nanocomposite fabricated by self-adsorption are superior to those of other materials. This can be attributed to the uniform dispersion of graphene and the strong attractive force between the PA46 matrix and graphene.
Mechanical and Dielectric Properties of Fly Ash Geopolymer/Sugarcane Bagasse Ash Composites
Authors: Chuewangkam Nattapong , Nachaithong Theeranuch , Chanlek Narong , Thongbai Prasit , Pinitsoontorn Supree
Published: March 2022

Fly ash (FA) and sugarcane bagasse ash (SCBA) are the wastes from lignite power plants and sugar industries, usually disposed of as landfills. In this research, these wastes were effectively utilized as a construction material, namely geopolymer. The effect of the SCBA (0–40 wt.%) addition to the FA geopolymers was investigated. The compressive strength of the FA geopolymers was reduced with the SCBA addition. The reduction was mainly due to the presence of the highly stable and non-reactive quartz (SiO2) phase in SCBA. The SCBA was not dissolved in the alkaline activated solution and hence did not contribute to the geopolymerization process. The unreacted SCBA particles remained in the geopolymer matrix but did not provide strength. However, if the amount of SCBA was about 10 wt.% or less, the impact on the characteristics and properties of FA geopolymers was minimal. Furthermore, this research also studied the dielectric properties of the FA geopolymer/SCBA composites. The relatively large dielectric constant (ε′ = 3.6 × 103) was found for the pristine geopolymer. The addition of SCBA decreased the ε′ slightly due to high carbon content in SCBA. Nevertheless, the variation in ε′ was mainly controlled by the geopolymerization process to form the aluminosilicate gel structure.
Fluorophenol-Containing Hydrogen-Bond Acidic Polysiloxane for Gas Sensing-Synthesis and Characterization
Authors: Grabka Michał , Kula Przemysław , Szala Mateusz , Jasek Krzysztof , Czerwiński Michał
Published: March 2022

In this work, the synthesis of a new polysiloxane, poly {dimethylsiloxane-co-[4-(2,3-difluoro-4-hydroxyphenoxy) butyl] methylsiloxane} (dubbed PMFOS), is presented. This polymer exhibits high hydrogen bond acidity and was designed to be used as a sensor layer in gas sensors. The description of the synthetic route of the PMFOS has been divided into two main stages: the synthesis of the functional substituent 4-(but-3-en-1-yloxy)-2,3-difluorophenol, and the post-polymerization functionalization of the polysiloxane chain (methylhydrosiloxane-dimethylsiloxane copolymer) via hydrosilylation. The synthesized material was subjected to instrumental analysis, which confirmed its structure. The performed thermal analysis made it possible to determine some properties important for the sensor application, such as glass transition temperature and decomposition temperature. The results showed that PMFOS meets the requirements for materials intended for use in gas sensors based on acoustoelectric transducers.
High-Level Expression of Nitrile Hydratase in Escherichia coli for 2-Amino-2,3-Dimethylbutyramide Synthesis
Authors: Deng Senwen , Zhu Shujing , Zhang Xinyi , Sun Xi , Ma Xiaoqiang , Su Erzheng
Published: March 2022

In the synthesis of imidazolinone herbicides, 2-Amino-2,3-dimethylbutyramide (ADBA) is an important intermedium. In this study, the recombinant production of nitrile hydratase (NHase) in Escherichia coli for ADBA synthesis was explored. A local library containing recombinant NHases from various sources was screened using a colorimetric method. NHase from Pseudonocardia thermophila JCM3095 was selected, fused with a His-tag and one-step purified. The enzymatic properties of recombinant NHase were studied and indicated robust thermal stability and inhibition of cyanide ions due to substrate degradation. After systematic optimization of fermentation conditions, the OD600 (optical density at 600 nm), enzyme activity and specific activity of recombinant strain E. coli BL21(DE3)/pET-28a+NHase reached 19.4, 3.72 U/mL and 1.04 U/mg protein at 42 h, representing 5.86-, 26.6- and 4-fold increases, respectively. These results offered an efficient recombinant whole-cell biocatalyst for ADBA synthesis.
Impact of Residential Real-World Wood Stove Operation on Air Quality concerning PM2.5 Immission
Authors: Thieringer Julia R. D. , Szabadi Julia , Meyer Jörg , Dittler Achim
Published: March 2022

In Germany, the number of small wood-burning combustion plants was around 11 million in 2020. The PM2.5 immissions caused by the operation of these combustion plants are already about as high as those from traffic exhaust gases. Thus, particulate matter immissions occur not only on busy roads but also in residential areas. Since there are few official measuring stations for PM2.5 in residential areas and suburbs, this study determined PM2.5 concentrations from November 2020 to June 2021 at three stations (urban, suburban, and residential) in the Karlsruhe area. Simultaneous measurements of PM2.5 at the three locations have been implemented to determine short-term (peaks), medium-term, and long-term particulate matter levels and to assign them to sources by observation, considering wind direction. Illustratively, PM2.5 immission levels in January and May 2021 were compared in this paper. The comparison of the particulate matter immissions measured in the urban and residential area in January revealed that PM2.5 concentration peaks of up to 60 µg/m3 occurred for short periods in the residential area, especially on Fridays and in the evenings, which could be assigned to wood stove operation. In the urban and suburban areas, the number of the immission peaks was lower by 70–80%, and the peak concentrations were also lower by an average of 13–18%. However, the high short-term peaks have no significant impact when calculating the PM2.5 annual average according to the current limit value regulation (39. BImSchV).
Grafting of Cellulose and Microcrystalline Cellulose with Oligo(L-lactic acid) by Polycondensation Reaction
Authors: Rahaman Md. Hafezur , Haque Md. Anamul , Rahman Md. Aminur , Rana Md. Masud , Parvez Md. Masud , Alam S. M. Nur
Published: March 2022

Oligo(L-lactic acid) (OLLA) was synthesized by ring opening polymerization of L-lactides using stannous octoate (0.03 wt% of lactide). While this served as the initiator, L-lactic acids were the co-initiators at 140 °C for 10 h, wherein L-lactic acids were prepared by hydrolytic degradation of L-lactides at 100 °C for 1 h. The molecular weight or degree of polymerization was controlled with monomer/co-initiator ratio (mol/mol). α-cellulose and microcrystalline cellulose (MCC) were extracted from jute fiber by subsequent treatment with sodium chlorite (Na2ClO2), NaOH and H2SO4. Grafting of OLLA onto α-cellulose and MCC in toluene was carried out using para-toluene sulphonic acid as a catalyst and potassium persulphate (KPS) as an initiator at 130 °C under 380 mm (Hg) pressure for 3, 6, 9, 12, 15, and 18 h. New properties of α-cellulose and MCC were observed due to the successful grafting onto α-cellulose and MCC. Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) were conducted in order to confirm grafting of OLLA onto cellulose and MCC. The FTIR analysis results showed there are some new characteristic absorption peaks appeared (1728 to 1732 cm−1) in the spectrum, which confirmed the grafting of OLLA onto α-cellulose and MCC was successful. SEM images of α-cellulose and MCC before and after grafting revealed significant changes in surface morphology. Grafting of MCC could be more effective for further application in comparison to α-cellulose.
Religious Violence and Twitter: Networks of Knowledge, Empathy and Fascination
Authors: Senbel Samah , Seigel Carly , Bryan Emily
Published: March 2022

Twitter analysis through data mining, text analysis, and visualization, coupled with the application of actor-network-theory, reveals a coalition of heterogenous religious affiliations around grief and fascination. While religious violence has always existed, the prevalence of social media has led to an increase in the magnitude of discussions around the topic. This paper examines the different reactions on Twitter to violence targeting three religious communities: the 2015 Charleston Church shooting, the 2018 Pittsburgh Synagogue shooting, and the 2019 Christchurch Mosque shootings. The attacks were all perpetrated by white nationalists with firearms. By analyzing large Twitter datasets in response to the attacks, we were able to render visible associations among actors across religions communities, national identities, and political persuasions. What this project revealed is that if we apply actor-network-theory and data visualization to look at networks created by human/non-human (text, computer, phone, meme, tweet, retweet, hashtag) actors, we can see that knowledge, empathy, and fascination drive communication around mass violence against religious communities.
Smartphone–Camera–Based Water Reflectance Measurement and Typical Water Quality Parameter Inversion
Authors: Gao Min , Li Junsheng , Wang Shenglei , Zhang Fangfang , Yan Kai , Yin Ziyao , Xie Ya , Shen Wei
Published: March 2022

Crowdsourced data from smart devices play an increasingly important role in water quality monitoring. However, guaranteeing and evaluating crowdsourced data quality is a key issue. This study aims to extract more accurate water reflectance data from smartphone photographs with variable exposure parameters, and to test the usability of these data in deriving water quality parameters. A set of low–cost reference cards was designed to be placed in the center of the photograph near the water surface, and a calculation model was proposed to convert the photograph digital numbers (DNs) to water reflectance. A nonlinear DN–to–reflectance model was constructed using the inherent reflectance and DN of the reference card in the photograph. Then, the reflectance of the water surface in the same photograph was estimated. During the evaluation of this scheme in seven different waterbodies with 112 sampling sites, small differences were observed between the estimated and measured remote sensing reflectance; the average unbiased relative errors (AUREs) for the red, green, and blue bands were 25.7%, 29.5%, and 35.2%, respectively, while the RMSEs for the three bands were 0.0032, 0.0051, 0.0031, respectively. The derived water reflectance data were used to retrieve the Secchi–disk depth (Zsd) and turbidity, with accuracies of 72.4% and 60.2%, respectively. The results demonstrate that the proposed method based on the smartphone camera can be used to derive the remote sensing reflectance and water quality parameters effectively with acceptable accuracy.
Columnar Water Vapor Retrieval by Using Data from the Polarized Scanning Atmospheric Corrector (PSAC) Onboard HJ-2 A/B Satellites
Authors: Xie Yanqing , Hou Weizhen , Li Zhengqiang , Zhu Sifeng , Liu Zhenhai , Hong Jin , Ma Yan , Fan Cheng , Guang Jie , Yang Benyong , Lei Xuefeng , Huang Honglian , Sun Xiaobing , Liu Xiao , Zhang Ying , Song Maoxin , Zou Peng , Qiao Yanli
Published: March 2022

As the latest members of Chinese Environmental Protection and Disaster Monitoring Satellite Constellation, the first two of HuanjingJianzai-2 (HJ-2) series satellites were launched on 27 September 2020 by China and are usually abbreviated as HJ-2 A/B satellites. The polarized scanning atmospheric corrector (PSAC) is one of main sensors onboard HJ-2 A/B satellites, which is mainly used to monitor atmospheric components such as water vapor and aerosols. In this study, a columnar water vapor (CWV) retrieval algorithm using two bands (865 and 910 nm) is developed for PSAC. The validation results of PSAC CWV data based on ground-based CWV data derived from Aerosol Robotic Network (AERONET) show that PSAC CWV data has a high accuracy, and all statistical parameters of PSAC CWV data are better than those of Moderate-resolution Imaging Spectroradiometer (MODIS) CWV data released by NASA. Overall, there is no obvious overestimation or underestimation in PSAC CWV data. The root mean square error (RMSE), mean absolute error (MAE), relative error (RE), and percentage of CWV data with error within ±(0.05+0.10∗CWVAERONET) (PER10) of PSAC CWV data are 0.17 cm, 0.13 cm, 0.08, and 78.19%, respectively. The RMSE, MAE, RE, and PER10 of MODIS CWV data are 0.59 cm, 0.48 cm, 0.28, and 16.55%, respectively. Compared with MODIS CWV data, PSAC CWV data shows a 71% decrease in RMSE, a 73% decrease in MAE, a 71% decrease in RE, and a 372% increase in PER10. In addition, the results of day-to-day comparisons between PSAC CWV data and AERONET data show that PSAC CWV data can effectively characterize the change trend of CWV.
Improved-UWB/LiDAR-SLAM Tightly Coupled Positioning System with NLOS Identification Using a LiDAR Point Cloud in GNSS-Denied Environments
Authors: Chen Zhijian , Xu Aigong , Sui Xin , Wang Changqiang , Wang Siyu , Gao Jiaxin , Shi Zhengxu
Published: March 2022

Reliable absolute positioning is indispensable in long-term positioning systems. Although simultaneous localization and mapping based on light detection and ranging (LiDAR-SLAM) is effective in global navigation satellite system (GNSS)-denied environments, it can provide only local positioning results, with error divergence over distance. Ultrawideband (UWB) technology is an effective alternative; however, non-line-of-sight (NLOS) propagation in complex indoor environments severely affects the precision of UWB positioning, and LiDAR-SLAM typically provides more robust results under such conditions. For robust and high-precision positioning, we propose an improved-UWB/LiDAR-SLAM tightly coupled (TC) integrated algorithm. This method is the first to combine a LiDAR point cloud map generated via LiDAR-SLAM with position information from UWB anchors to distinguish between line-of-sight (LOS) and NLOS measurements through obstacle detection and NLOS identification (NI) in real time. Additionally, to alleviate positioning error accumulation in long-term SLAM, an improved-UWB/LiDAR-SLAM TC positioning model is constructed using UWB LOS measurements and LiDAR-SLAM positioning information. Parameter solving using a robust extended Kalman filter (REKF) to suppress the effect of UWB gross errors improves the robustness and positioning performance of the integrated system. Experimental results show that the proposed NI method using the LiDAR point cloud can efficiently and accurately identify UWB NLOS errors to improve the performance of UWB ranging and positioning in real scenarios. The TC integrated method combining NI and REKF achieves better positioning effectiveness and robustness than other comparative methods and satisfactory control of sensor errors with a root-mean-square error of 0.094 m, realizing subdecimeter indoor positioning.
Intelligent Control of Building Operation and Maintenance Processes Based on Global Navigation Satellite System and Digital Twins
Authors: Liu Zhansheng , Shi Guoliang , Meng Xiaolin , Sun Zhe
Published: March 2022

Building operation and maintenance (O&M) processes are tedious. Controlling such tedious processes requires extensive visualization and trustworthy decision-making strategies. Unfortunately, challenges still exist as existing technologies and practices can hardly achieve effective control of building O&M processes. This study has established a method for achieving intelligent control of building O&M processes by integrating Global Navigation Satellite System (GNSS) with Digital Twins (DTs) techniques. Specifically, GNSS could be used to capture real-time building information during building O&M processes. Such captured real-time information realizes the intelligent closed-loop control of building O&M driven by DTs. In this study, the authors have (1) captured the dynamic information required for achieving intelligent control of building O&M processes, (2) established a DT model of building O&M processes, (3) established a data management mechanism of intelligent building O&M processes, and (4) formalized an intelligent building O&M decision control platform. Finally, the authors have validated the proposed method using the 2022 Beijing Winter Olympics venue as a case study. The three-dimensional coordinates of various building information are captured based on GNSS automatic monitoring system. This realizes the precise positioning of O&M elements and feedbacks to the twin model of the venue. Through the intelligent analysis and prediction of O&M information, the characteristics of various O&M accidents are obtained. Finally, under the navigation function of GNSS, the processing measures are accurately formulated. Results indicate that the proposed GNSS–DTs-based method could help to achieve intelligent control of large building O&M processes.
Estimation of Parameters of Biomass State of Sowing Spring Wheat
Authors: Mikhailenko Ilya Mikhayilovich
Published: March 2022

The purpose of this work is to present a new method for estimating the parameters of the biomass of agricultural crops based on Earth remote sensing (ERS) data. The method includes mathematical models and algorithms estimation and has been tested on the example of spring wheat sowing. Sowing biomass parameters are the basis for making management decisions aimed at obtaining a given crop yield. Currently, for these purposes, vegetation indices are most widely used. It is impossible to estimate the physical parameters of the crop sowing biomass using these indices, due to their scalar form and lack of dimension. The paper develops a classical approach to the problem of estimating the parameters of the state of agricultural crops, in which remote sensing data are considered as an indirect measurement of the estimated parameters. The basis for the implementation of the estimation method is the dynamic model of biomass parameters and the remote sensing model, which reflects the relationship between the spectral reflection parameters and the estimated parameters of the crop biomass. The parameters of the dynamic model and the remote sensing model are refined by selective ground measurements in separate elementary sections of the field. The difference between this article and previous works of a similar nature lies in the fact that agricultural crops with a more complex morphological structure are considered as the object of evaluation. In addition, such an important feature of agricultural objects as their spatial distribution is considered here. To take it into account, a new type of mathematical models is used, in which spatial coordinates are introduced. Due to the significant complication of modeling and estimation algorithms based on such models, simpler approximation schemes are proposed. The advantage of the proposed approach is that the assessment is considered as a dynamic process that meets the content of the task of monitoring crops.
Analysis of Precise Orbit Determination for the HY2D Satellite Using Onboard GPS/BDS Observations
Authors: Peng Hailong , Zhou Chongchong , Zhong Shiming , Peng Bibo , Zhou Xuhua , Yan Haoming , Zhang Jie , Han Jinyang , Guo Fengcheng , Chen Runjing
Published: March 2022

High-precision orbits of Low Earth Orbit (LEO) satellites are essential for many scientific applications, such as assessing the change in current global mean sea level, estimating the coefficients of gravity field, and so on. How to determinate the high-precision orbits for LEO satellites has gradually become an important research focus. HY2D is a new altimetry satellite of China, which is equipped with a Global Positioning System (GPS) and the third generations of the BeiDou Global Navigation Satellite System (BDS-3) in order to guarantee the reliability of orbital precision in radar altimetry mission. Therefore, this study adopts one month of spaceborne data to conduct the research of precise orbit determination (POD) for the HY2D satellite. Our analysis results are: (1) The standard deviation of residuals for the HY2D satellite based on spaceborne BDS and GPS data are 9.12 mm and 8.53 mm, respectively, and there are no significant systematic errors in these residuals. (2) The comparison results with Doppler Orbitography and Radio-positioning Integrated by Satellite (DORIS)-derived orbits indicate that the HY2D satellite, using spaceborne BDS and GPS data, can achieve the radial accuracy of 1.4~1.5 cm, and the mean three-dimensional (3D) accuracy are 5.3 cm and 4.3 cm, respectively, which can satisfy high-precision altimetry applications. (3) By means of satellite laser ranging (SLR), the accuracy of Global Navigation Satellite System (GNSS)-derived orbits of HY2D is approximately 3.3 cm, which reflects that the model strategies are reliable.
Cotton Cultivated Area Extraction Based on Multi-Feature Combination and CSSDI under Spatial Constraint
Authors: Hong Yong , Li Deren , Wang Mi , Jiang Haonan , Luo Lengkun , Wu Yanping , Liu Chen , Xie Tianjin , Zhang Qing , Jahangir Zahid
Published: March 2022

Cotton is an important economic crop, but large-scale field extraction and estimation can be difficult, particularly in areas where cotton fields are small and discretely distributed. Moreover, cotton and soybean are cultivated together in some areas, further increasing the difficulty of cotton extraction. In this paper, an innovative method for cotton area estimation using Sentinel-2 images, land use status data (LUSD), and field survey data is proposed. Three areas in Hubei province (i.e., Jingzhou, Xiaogan, and Huanggang) were used as research sites to test the performance of the proposed extraction method. First, the Sentinel-2 images were spatially constrained using LUSD categories of irrigated land and dry land. Seven classification schemes were created based on spectral features, vegetation index (VI) features, and texture features, which were then used to generate the SVM classifier. To minimize misclassification between cotton and soybean fields, the cotton and soybean separation index (CSSDI) was introduced based on the red band and red-edge band of Sentinel-2. The configuration combining VI and spectral features yielded the best cotton extraction results, with F1 scores of 86.93%, 80.11%, and 71.58% for Jingzhou, Xiaogan, and Huanggang. When CSSDI was incorporated, the F1 score for Huanggang increased to 79.33%. An alternative approach using LUSD for non-target sample augmentation was also introduced. The method was used for Huangmei county, resulting in an F1 score of 78.69% and an area error of 7.01%. These results demonstrate the potential of the proposed method to extract cotton cultivated areas, particularly in regions with smaller and scattered plots.
Pedagogical Patterns for tMOOC as a Social Technology of Relationship
Authors: Amorós-Poveda Lucía , Cabero-Almenara Julio , Palacios-Rodríguez Antonio
Published: March 2022

Information communication technologies, as technologies of human relations (ICRT), are linked with pedagogical patterns. Co-design, as a dialogic, participatory, and relational process, leads task based Massive Open Online Course (tMOOC) to justify the use of ICRT for lifelong learning. From sociocultural constructivism principles, patterns offer possibilities for participation by collaborating with professionals (teachers, designers, researchers) and students. On this subject, patterns involve everyone in the learning scenario, transferring best practices in the pattern language. Applying triangulation as a methodology, we are focused on two aims: analyzing the documentation of pedagogical patterns as a technology of relation (O.1), and synthesizing the information according to tMOOC (O.2). Eleven documents are worked on, including scientific articles, research reports, and a conference paper. As a result, patterns are explored and described according to their processes, structures, modalities, methods, and resources. Finally, it is concluded that patterns underline collaborative tasks where the methodology based on design (IBL) is beneficial for the digital competence of educators. However, evaluative research directed to platforms in real contexts is necessary, attending to group management, metrics, and modeling.
The Relationship between Human-Capital Variables and Innovative Performance: Evidence from Colombia
Authors: Carvache-Franco Orly , Carvache-Franco Mauricio , Carvache-Franco Wilmer , Bustamante-Ubilla Miguel A.
Published: March 2022

The objective of the research is to analyze the variables of human capital and its relationship with innovation in manufacturing companies. The study is quantitative, nonexperimental, cross-sectional data obtained from Colombia, an emerging country, collected from a national survey of innovation activities. The regression used is bivariate probit. The findings show that the variable “R&D workers” is related to product and process innovation and the variable “workers with higher education” is related to product innovation. The theoretical implication is that the “R&D workers” variable is an important predictor for product and process innovation because it represents skills, abilities, and worker’s experience, and enables finding new uses for knowledge or combining knowledge to achieve innovation. Furthermore, in these companies, the human capital acquired through education develops the skills and abilities that enable product innovation to be achieved, while low investment in training means that the skills achieved by this means are not significant for innovation. The study has practical implications for managers in emerging countries who want to increase the companies’ innovative potential by increasing investment in education and training of its workers.
Passenger Flow Prediction of Scenic Spot Using a GCN–RNN Model
Authors: Xu Zhijie , Hou Liyan , Zhang Yueying , Zhang Jianqin
Published: March 2022

The prediction and control of passenger flow in scenic spots is very important to the traffic management and safety of scenic spots. This study aims to predict the passenger flow of a scenic spot based on the passenger flow of the bus and subway stations around the scenic spots. We propose a passenger flow prediction model based on graph convolutional network–recurrent neural network (GCN–RNN). First, a “graph” is constructed according to the geographical relationship between the scenic spot and the surrounding bus and subway stations. Then, characteristics of surrounding areas of bus and subway stations are constructed based on the crowd behavior analysis, and these are then used as the node-information of the “graph”. Last, the GCN–RNN model is used to extract the temporal and spatial characteristics of the passenger flow data of the scenic spot to realize the prediction. The experimental results show that the proposed model is effective in passenger flow prediction in scenic spots.
Elevated Atmospheric CO2 Concentration Influences the Rooting Habits of Winter-Wheat (Triticum aestivum L.) Varieties
Authors: Varga Balázs , Farkas Zsuzsanna , Varga-László Emese , Vida Gyula , Veisz Ottó
Published: March 2022

The intensity and the frequency of extreme drought are increasing worldwide. An elevated atmospheric CO2 concentration could counterbalance the negative impacts of water shortage; however, wheat genotypes show high variability in terms of CO2 reactions. The development of the root system is a key parameter of abiotic stress resistance. In our study, biomass and grain production, as well as the root growth of three winter-wheat varieties were examined under optimum watering and simulated drought stress in a combination with ambient and elevated atmospheric CO2 concentrations. The root growth was monitored by a CI-600 in situ root imager and the photos were analyzed by RootSnap software. As a result of the water shortage, the yield-related parameters decreased, but the most substantial yield reduction was first detected in Mv Karizma. The water shortage influenced the depth of the intensive root development, while under water-limited conditions, the root formation occurred in the deeper soil layers. The most intensive root development was observed until the heading, and the maximum root length was recorded at the beginning of the heading. The period of root development took longer under elevated CO2 concentration. The elevated CO2 concentration induced an accelerated root development in almost every soil layer, but generally, the CO2 fertilization induced in the root length of all genotypes and under each treatment.
Optimization of Solidification and Stabilization Efficiency of Heavy Metal Contaminated Sediment Based on Response Surface Methodology
Authors: Yang Yang , Li Moting , Sun Yan , Gao Huimin , Mao Lingchen , Zhang He , Tao Hong
Published: March 2022

Solidification and stabilization (S/S) by agents and stabilizers is an effective way to treat heavy metal-contaminated sediments. Optimization of curing condition is crucial to minimize the consumption of reagents on the base of effective S/S. In this work, the synergistic effects of cement and stabilizer on mechanical strength and leaching toxicity of contaminated sediments were investigated, and the S/S conditions were optimized using response surface methodology. On the basis of a single-factor test, multi-factor experiments were conducted to fit the relationship between the S/S effect of contaminated sediments and the amount of cement and stabilizer. The mechanism of stabilization was investigated by the results from the revised BCR method. The results indicate that the optimal curing conditions were 44.29% of cement content with 2.05% of trimercapto-s-triazine trisodium salt (TMT). After 28 days of curing, the compressive strength reached 2.07 MPa and the leaching concentrations of Cd, Cu, and Pb were 0.094 mg/L, 0.031 mg/L, and 0.173 mg/L, respectively, which met the requirement of in-situ resource recycling standard. The stability of heavy metals was significantly improved as a result of the removal of acid extractable fraction (15.58~69.92%) and an increase in the residual fraction (18.27~49.07%).
Anaerobic Co-Digestion of Food Waste with Livestock Manure at Ambient Temperature: A Biogas Based Circular Economy and Sustainable Development Goals
Authors: Dhungana Bipasyana , Lohani Sunil Prasad , Marsolek Michael
Published: March 2022

A shift from a linear economy to a circular economy of resource consumption is vital for diverting the value from lost resources to resource-efficient products towards developing a sustainable system. Household digesters provide one opportunity to create a biogas-based circular economy. Because household digesters are typically fed a wide and variable range of substrates, it is important to determine the ideal mixing ratios for them. In this study, an anaerobic digester startup process was analyzed and an assessment of anaerobic co-digestion of food waste with different livestock manures was carried out at ambient temperatures. Food waste (FW), cow manure (CM), poultry litter (PL) and goat manure (GM) were co-digested at mixing ratios (FW:PL:CM) of 2:1:1, 2:2:1, 1:1:2, 1:1:1 (wt/wt) and FW:PL:GM at mixing ratios of 2:1:1 and 1:1:2, at an organic loading rate of 1 g volatile solid (VS)/L/day, and 8% total solids. A maximum methane yield was obtained from co-digestion of FW:PL:GM at a mixing ratio of 2:1:1 in autumn-to-winter conditions, 21–10 °C, while the mixing ratio of FW:PL:CM at 2:2:1, showed negligible methane production under the same temperature condition. This study suggests that co-digestion of food waste and poultry litter with goat manure yields more biogas than other substrate combinations. Therefore, selecting suitable co-substrates with an optimized mixing ratio can promote several key indicators of a biogas-based circular economy towards achieving sustainable development goals 2, 3, 5, 6, 7, 9, 13 and 15.
Optimization of Phenolic Compound Extraction from Brewers’ Spent Grain Using Ultrasound Technologies Coupled with Response Surface Methodology
Authors: Iadecola Rosamaria , Ciccoritti Roberto , Ceccantoni Brunella , Bellincontro Andrea , Amoriello Tiziana
Published: March 2022

Brewers’ spent grain (BSG) is the main solid by-product from the brewery industry, rich in valuable nutrients and bioactive compounds. The aim of this study was to valorize this by-product, recovering phenolic compounds from BSG using ultrasound-assisted extraction (UAE) and chemometric techniques, such as the response surface methodology (RSM). Therefore, UAE process parameters (temperature and time) and solvent composition (ethanol aqueous mixtures) were optimized using a three-level Box–Behnken design, in order to carry out the maximum yield in phenols. Then, the extract obtained under optimal conditions was characterized for the total phenolic content and antioxidant capacity (2,20-azino-bis(3-ethylbenothiazoline-6-sulphonic acid, ABTS, and 2,2-diphenyl-1-picrylhydrazyl, DPPH), and individual phenolic compounds were identified using HPLC-DAD. The results show the highest level of total soluble phenolic content (4.1 ± 0.1 mg GAE/g d.w.) at 80 °C, 50 min and 65:35% ethanol:water, with a high goodness of fit between experimental and predicted values (R2 = 0.987), and a high antioxidant potential (DPPH: 0.42 ± 0.01 mg TE eq/g d.w.; ABTS: 5.82 ± 0.04 mg TE eq/g d.w.). A comparison between the classic extraction techniques and the UAE with the same solvent showed an increase of 156% in the phenol yield. The characterization of phenolic profile revealed that ferulic acid (1.5 ± 0.2 mg/L), vanillic acid (0.78 ± 0.18 mg/L) and p-coumaric acid (0.12 ± 0.03 mg/L) were the prevalent ones. UAE coupled with RSM was a useful tool to inexpensively and quickly recover bioactive phenolic compounds from BSG, which can be used in the food, pharmaceutical or cosmetic industries.
UK Government Policy and the Transition to a Circular Nutrient Economy
Authors: Yuille Andy , Rothwell Shane , Blake Lynsay , Forber Kirsty J. , Marshall Rachel , Rhodes Richard , Waterton Claire , Withers Paul J. A.
Published: March 2022

The “circular economy” is an increasingly influential concept linking economic and environmental policy to enable sustainable use of resources. A crucial although often overlooked element of this concept is a circular nutrient economy, which is an economy that achieves the minimization of nutrient losses during the production, processing, distribution, and consumption of food and other products, as well as the comprehensive recovery of nutrients from organic residuals at each of these stages for reuse in agricultural production. There are multiple interconnecting barriers to transitioning from the current linear economic system to a more circular one, requiring strongly directional government policy. This paper uses interpretive policy analysis to review six UK government strategies to assess their strengths and weaknesses in embracing nutrient circularisation. Our analysis highlights the acute underrepresentation of the circular nutrient economy concept in these strategies as well as the potential to reorient the current policy towards its development. We find significant barriers to transition presented by ambiguity in key policy terms and proposals, the use of inappropriate indicators, the lack of a systematic approach to key sustainability objectives, and the presence of a “techno-optimist imaginary” throughout the strategies. We develop these findings to make recommendations to help integrate definitions, objectives, and activities across the policy domains necessary for the operational development of a circular nutrient economy.