bluuebunny/crossref_metadata_2025 huggingface dataset:
A Metabolic Enhancer Protects against Diet-Induced Obesity and Liver Steatosis and Corrects a Pro-Atherogenic Serum Profile in Mice
Authors: Platko Khrystyna , Lebeau Paul , Nederveen Joshua , Byun Jae , MacDonald Melissa , Bourgeois Jacqueline , Tarnopolsky Mark , Austin Richard
Published: May 2023

Objective: Metabolic Syndrome (MetS) affects hundreds of millions of individuals and constitutes a major cause of morbidity and mortality worldwide. Obesity is believed to be at the core of metabolic abnormalities associated with MetS, including dyslipidemia, insulin resistance, fatty liver disease and vascular dysfunction. Although previous studies demonstrate a diverse array of naturally occurring antioxidants that attenuate several manifestations of MetS, little is known about the (i) combined effect of these compounds on hepatic health and (ii) molecular mechanisms responsible for their effect. Methods: We explored the impact of a metabolic enhancer (ME), consisting of 7 naturally occurring antioxidants and mitochondrial enhancing agents, on diet-induced obesity, hepatic steatosis and atherogenic serum profile in mice. Results: Here we show that a diet-based ME supplementation and exercise have similar beneficial effects on adiposity and hepatic steatosis in mice. Mechanistically, ME reduced hepatic ER stress, fibrosis, apoptosis, and inflammation, thereby improving overall liver health. Furthermore, we demonstrated that ME improved HFD-induced pro-atherogenic serum profile in mice, similar to exercise. The protective effects of ME were reduced in proprotein convertase subtilisin/kexin 9 (PCSK9) knock out mice, suggesting that ME exerts it protective effect partly in a PCSK9-dependent manner. Conclusions: Our findings suggest that components of the ME have a positive, protective effect on obesity, hepatic steatosis and cardiovascular risk and that they show similar effects as exercise training.
Translational Research on Bee Pollen as a Source of Nutrients: A Scoping Review from Bench to Real World
Authors: Kacemi Rachid , Campos Maria G.
Published: May 2023

The emphasis on healthy nutrition is gaining a forefront place in current biomedical sciences. Nutritional deficiencies and imbalances have been widely demonstrated to be involved in the genesis and development of many world-scale public health burdens, such as metabolic and cardiovascular diseases. In recent years, bee pollen is emerging as a scientifically validated candidate, which can help diminish conditions through nutritional interventions. This matrix is being extensively studied, and has proven to be a very rich and well-balanced nutrient pool. In this work, we reviewed the available evidence on the interest in bee pollen as a nutrient source. We mainly focused on bee pollen richness in nutrients and its possible roles in the main pathophysiological processes that are directly linked to nutritional imbalances. This scoping review analyzed scientific works published in the last four years, focusing on the clearest inferences and perspectives to translate cumulated experimental and preclinical evidence into clinically relevant insights. The promising uses of bee pollen for malnutrition, digestive health, metabolic disorders, and other bioactivities which could be helpful to readjust homeostasis (as it is also true in the case of anti-inflammatory or anti-oxidant needs), as well as the benefits on cardiovascular diseases, were identified. The current knowledge gaps were identified, along with the practical challenges that hinder the establishment and fructification of these uses. A complete data collection made with a major range of botanical species allows more robust clinical information.
Kudoa septempunctata Spores Cause Acute Gastroenteric Symptoms in Mouse and Musk Shrew Models as Evidenced In Vitro in Human Colon Cells
Authors: Hong Sung-Hee , Kwon Ji-Young , Lee Soon-Ok , Lee Hee-Il , Hong Sung-Jong , Ju Jung-Won
Published: May 2023

Kudoa septempunctata is a myxosporean parasite that infects the trunk muscles of olive flounder (Paralichthys olivaceus) and has been reported to cause foodborne illnesses in humans. However, the molecular mechanisms underlying K. septempunctata spore toxicity remain largely unknown. In this study, the gastroenteropathy of K. septempunctata was examined in human colon adenocarcinoma cells as well as experimental mice inoculated with spores. We found that K. septempunctata decreased transepithelial resistance and disrupted epithelial tight junctions by deleting ZO-1 in Caco-2 monolayers. Additionally, serotonin (5-HT), an emetic neurotransmitter, was increased in K. septempunctata-inoculated cells. In vivo, K. septempunctata spores induced diarrhea in suckling mice (80% in ddY and 70% in ICR mice), with a minimum provocative dose of 2 × 105 K. septempunctata spores. In house musk shrews, K. septempunctata induced emesis within 1 h and induced serotonin secretion in the intestinal epithelium. In conclusion, K. septempunctata may induce diarrhea and emesis by increasing intestinal permeability and serotonin secretion.
Comparative study of Plasmodium falciparum msp-1 and msp-2 Genetic Diversity in Isolates from Rural and Urban Areas in the South of Brazzaville, Republic of Congo
Authors: Baina Marcel Tapsou , Lissom Abel , Assioro Doulamo Naura Veil , Djontu Jean Claude , Umuhoza Dieu Merci , Mbama-Ntabi Jacques Dollon , Diafouka-Kietela Steve , Mayela Jolivet , Missontsa Georges , Wondji Charles , Adegnika Ayola Akim , Nguimbi Etienne , Borrmann Steffen , Ntoumi Francine
Published: May 2023

Polymorphisms in the genes encoding the merozoite surface proteins msp-1 and msp-2 are widely used markers for characterizing the genetic diversity of Plasmodium falciparum. This study aimed to compare the genetic diversity of circulating parasite strains in rural and urban settings in the Republic of Congo after the introduction of artemisinin-based combination therapy (ACT) in 2006. A cross-sectional survey was conducted from March to September 2021 in rural and urban areas close to Brazzaville, during which Plasmodium infection was detected using microscopy (and nested-PCR for submicroscopic infection). The genes coding for merozoite proteins-1 and -2 were genotyped by allele-specific nested PCR. Totals of 397 (72.4%) and 151 (27.6%) P. falciparum isolates were collected in rural and urban areas, respectively. The K1/msp-1 and FC27/msp-2 allelic families were predominant both in rural (39% and 64%, respectively) and urban (45.4% and 54.5% respectively) areas. The multiplicity of infection (MOI) was higher (p = 0.0006) in rural areas (2.9) compared to urban settings (2.4). The rainy season and the positive microscopic infection were associated with an increase in MOI. These findings reveal a higher P. falciparum genetic diversity and MOI in the rural setting of the Republic of Congo, which is influenced by the season and the participant clinical status.
Herb Robert’s Gift against Human Diseases: Anticancer and Antimicrobial Activity of Geranium robertianum L.
Authors: Świątek Łukasz , Wasilewska Inga , Boguszewska Anastazja , Grzegorczyk Agnieszka , Rezmer Jakub , Rajtar Barbara , Polz-Dacewicz Małgorzata , Sieniawska Elwira
Published: May 2023

Geranium robertianum L. is a widely distributed plant used as a traditional herbal medicine, but the knowledge of its biological properties still needs to be improved. Thus, the purpose of this presented research was to assess the phytochemical profile of extracts from aerial parts of G. robertianum, commercially available in Poland and to study their anticancer potential and antimicrobial properties, including the antiviral, antibacterial, and antifungal effects. Additionally, the bioactivity of fractions obtained from the hexane and ethyl acetate extract was analyzed. The phytochemical analysis revealed the presence of organic and phenolic acids, hydrolysable tannins (gallo- and ellagitannins), and flavonoids. Significant anticancer activity was found for G. robertianum hexane extract (GrH) and ethyl acetate extract (GrEA) with an SI (selectivity index) between 2.02 and 4.39. GrH and GrEA inhibited the development of HHV-1-induced cytopathic effect (CPE) in virus-infected cells and decreased the viral load by 0.52 log and 1.42 log, respectively. Among the analyzed fractions, only those obtained from GrEA showed the ability to decrease the CPE and reduce the viral load. The extracts and fractions from G. robertianum showed a versatile effect on the panel of bacteria and fungi. The highest activity was observed for fraction GrEA4 against Gram-positive bacteria, including Micrococcus luteus ATCC 10240 (MIC 8 μg/mL), Staphylococcus epidermidis ATCC 12228 (MIC 16 μg/mL), Staphylococcus aureus ATCC 43300 (MIC 125 μg/mL), Enterococcus faecalis ATCC 29212 (MIC 125 μg/mL), and Bacillus subtilis ATCC 6633 (MIC 125 μg/mL). The observed antibacterial effect may justify the traditional use of G. robertianum to treat hard-to-heal wounds.
Laws Governing Nitrogen Loss and Its Numerical Simulation in the Sloping Farmland of the Miyun Reservoir
Authors: Li Yan , Jin Liang , Wu Jiajun , Shi Chuanqi , Li Shuo , Xie Jianzhi , An Zhizhuang , Suo Linna , Ding Jianli , Wei Dan , Wang Lei
Published: May 2023

Surface flow (SF) and subsurface flow (SSF) are important hydrological processes occurring on slopes, and are driven by two main factors: rainfall intensity and slope gradient. To explore nitrogen (N) migration and loss from sloping farmland in the Miyun Reservoir, the characteristics of total nitrogen (TN) migration and loss via SF and SSF under different rainfall intensities (30, 40, 50, 60, 70, and 80 mm/h) and slope gradients (5°, 10°, and 15°) were studied using indoor stimulated rainfall tests and mathematical models. Nitrogen loss via SF and SSF was found to increase exponentially and linearly with time, respectively, with SSF showing 14–78 times higher loss than SF. Under different rainfall intensities, SSF generally had larger TN loss loading than SF, thereby indicating that SSF was the main route for TN loss. However, the TN loss loading proportion via SF increasing from 14.03% to 35.82% with increasing rainfall intensity is noteworthy. Furthermore, compared with the measurement data, the precision evaluation index Nash-Suttcliffe efficient (NSE) and the determination coefficient (R2) of the effective mixing depth model in the numerical simulation of TN loss through SF in the sloping farmland in the Miyun Reservoir were 0.74 and 0.831, respectively, whereas those of the convection-dispersion equation for SSF were 0.81 and 0.811, respectively, thus indicating good simulation results. Therefore, this paper provides a reference for studying the mechanism of N migration and loss in sloping farmland in the Miyun Reservoir.
GASA Proteins: Review of Their Functions in Plant Environmental Stress Tolerance
Authors: Bouteraa Mohamed Taieb , Ben Romdhane Walid , Baazaoui Narjes , Alfaifi Mohammad Y. , Chouaibi Yosra , Ben Akacha Bouthaina , Ben Hsouna Anis , Kačániová Miroslava , Ćavar Zeljković Sanja , Garzoli Stefania , Ben Saad Rania
Published: May 2023

Gibberellic acid-stimulated Arabidopsis (GASA) gene family is a class of functional cysteine-rich proteins characterized by an N-terminal signal peptide and a C-terminal-conserved GASA domain with 12 invariant cysteine (Cys) residues. GASA proteins are widely distributed among plant species, and the majority of them are involved in the signal transmission of plant hormones, the regulation of plant development and growth, and the responses to different environmental constraints. To date, their action mechanisms are not completely elucidated. This review reports an overview of the diversity, structure, and subcellular localization of GASA proteins, their involvement in hormone crosstalk and redox regulation during development, and plant responses to abiotic and biotic stresses. Knowledge of this complex regulation can be a contribution to promoting multiple abiotic stress tolerance with potential agricultural applications through the engineering of genes encoding GASA proteins and the production of transgenic plants.
Optimization of One-Time Fertilization Scheme Achieved the Balance of Yield, Quality and Economic Benefits of Direct-Seeded Rice
Authors: Cheng Shuang , Xing Zhipeng , Tian Chao , Weng Wen’an , Hu Qun , Zhang Hongcheng
Published: May 2023

There is limited information available to assess the impact of one-time fertilization on the yield, quality, and economic benefits of direct-seeded rice. This study reports the effects of three one-time fertilizer treatments (BBU1, BBU2, and BBU3) on the yield, quality, and economic benefits of direct-seeded rice, where controlled-release nitrogen (N) fertilizer (CRNF) provided 50%, 60%, and 70% of the total N (270 kg N ha−1), and the control treatment (CK) was a split application of conventional urea (CU). The results showed that the yield of direct-seeded rice decreased significantly (p < 0.05) with the increased application ratio of CRNF under one-time fertilization, which was mainly related to N accumulation between the heading time and maturity stages. Compared to CK, the one-time fertilization treatments (BBU1, BBU2, and BBU3) maintained high milling quality, with significantly reduced chalkiness (p < 0.05), which could be related to the slow rate of N release from the CRNF. In addition, the one-time fertilization treatments reduced the protein content and increased the amylose content of the milled rice, which significantly improved the eating quality (p < 0.05). Furthermore, there was no significant difference in yield and economic benefit between BBUI and CK (p > 0.05). Overall, CRNF replacing conventional urea with 50% total N could be helpful to reduce fertilization frequency, achieve high yield and high economic efficiency, and improve rice quality of direct-seeded rice under one-time fertilization.
Estimation of Fracture Height in Tight Reserviors via a Finite Element Approach
Authors: Cai Jiujie , Li Fengxia
Published: May 2023

In tight reservoirs, the rock formations are typically less porous and permeable, which makes it more difficult for hydrocarbons to flow through them. In addition to length and conductivity, the height of a fracture is another critical parameter of the hydraulic fracturing treatments in unconventional tight/shale formations, which determines the stimulated reservoir volume. If the fracture height is too shallow, the volume of rock exposed to the fluid and proppant may not be sufficient to improve the reservoir’s production significantly. Conversely, if the fracture height is too deep, the injected fluid may not be able to propagate high enough to reach the desired formation. However, after years of research, fracture height has often been simplified in traditional or recent studies of fracture simulation and estimation. The objective of this work is to propose an innovative way to simulate the hydraulic fracturing process in both horizontal and vertical directions in tight formations with a well-built finite element numerical model. Fracture toughness KIC is calculated based on the Brazilian test. Vertical fracturing fluid was also considered, and the model was validated by fracture height monitoring data from a stimulated well in the Montney formation. The influence of rock and fluid properties on the fracture height propagation was studied thoroughly with sensitivity analysis. The results indicated the fracture height prediction model was in good accordance with the monitoring data collected from the field, with an error margin of 7.2%. Sensitivity analysis results showed that a high Young’s modulus led to a larger stress intensity factor at the fracture tip, thus further advancing the fracture. Minimum horizontal stress also tends to facilitate the fracture to propagate. The influence of Poisson’s ratio and fluid viscosity on fracture height propagation was also investigated.
Interfacial Adsorption Mechanism of Diethyldithiocarbamate in High-Sulfur Residue Flotation
Authors: Liu Hong , He Jing , Luo Tao , Dai Jie , Cao Shuqiong , Yang Shenghai , Tang Chaobo , Wang Changhong , Chen Yongming
Published: May 2023

Diethyldithiocarbamate (DDTC) is employed in the sulfide ore flotation process due to its excellent collection performance. Herein, we investigated the interfacial adsorption behavior of DDTC on the four main mineral phases of high-sulfur residue: sulfur, pyrite, sphalerite, and lead sulfate. The adsorption behavior of DDTC and H2O, namely, the adsorption structure and the energy and electron localization function cross section, were explored using density function theory calculation. The results were helpful in constructing a coadsorption model of DDTC and H2O, which was validated by pure mineral flotation and characterization of Fourier transform infrared spectra. The coadsorption model indicated that the adsorption of DDTC on sulfur, sphalerite, and lead sulfate was weak with physical bonding, while its adsorption on pyrite was strong with chemical bonding. Practical bench-scale high-sulfur residue flotation was performed, and the result was different from that obtained from pure mineral flotation. Our developed model predictions and mineral fugacity pattern analysis were synergistically used to explain this difference. Overall, this work proposes for the first time a coadsorption model of DDTC and H2O and provides important insights into interfacial adsorption in high-sulfur residue flotation.
Generalized Distribution Feeder Switching with Fuzzy Indexing for Energy Saving
Authors: Lin Whei-Min , Tsai Wen-Chang
Published: May 2023

The objective of this study is to analyze feeder loss minimization and load balance under given constrains. Effective methods are required for feeder switching/reconfiguration. Feeder switching is a mixed-integer large-scale combinatorial problem for optimization, not easily solvable with classical optimization techniques, especially involving a great number of switches. This paper proposes a fuzzy indexing algorithm for feeder switching, with membership functions defined for switches such as thermometers or indices. The optimal switches can be determined through fuzzy index operations. With membership functions defined, the developed method used numerical operations for indices instead of the “set” operation or the min-max operations of traditional fuzzy algorithms. The optimization problem becomes a simple numeric calculation instead of a large-scale sorting problem and is much faster than most algorithms. It greatly reduces the computation time and enhances efficiency, which is suitable for either planning or operation purposes. Many algorithms were tested with three typical examples chosen for illustration, including the “optimal” results with an exhausted search. It shows that the proposed algorithm is very effective and can balance the load to reduce the loss and costs in obtaining the solution.
Special Issue on “Composting in the Framework of a Circular Economy”
Authors: Sánchez Antoni
Published: May 2023

Composting has been recognized as a sustainable technology to treat and manage organic waste [...]
An Experimental Study on the Elbow Pressure Drop and Conveying Stability of Pneumatic Conveying for Stiff Shotcrete Based on Response Surface Methodology
Authors: Sun Zhenjiao , Chen Lianjun , Ma Guanguo , Ma Hui , Gao Kang
Published: May 2023

The pressure drop and conveying stability caused by the bend significantly affect the pneumatic conveying process of stiff shotcrete, which is the key to solving the problem of long-distance transportation. In this paper, the effects of different air velocities (32 m/s, 36 m/s, 40 m/s), water-cement ratios (0.1, 0.2, and 0.3), and bending-diameter ratios (4, 12, and 20) on the pressure drop of the elbow R1 and conveying stability R2 are studied using the response surface method. The conveying stability is characterized by the pressure variation coefficient (C.V). The response surface graph aids in the intuitive analysis of the effects of these variables. The results show that the impact of air velocity on R1 and R2 is exceptionally significant, and the interaction of each factor on the response value is analyzed. The response value and the quadratic polynomial regression equation between the various factors are obtained in addition to the flow characteristics of stiff shotcrete under different working conditions. The relationship established by the statistical processing of the experimental results can provide some reference for specifying the pressure loss model of stiff shotcrete.
Prediction and Application of Surface Settlement of Shallow Buried Tunnels Taking into Account Strata Slip Cracks
Authors: Ma Zhonggang , Xie Xiaofei , Jia He , Zhao Junwei , He Sunwen , Wang Xiaohua
Published: May 2023

The empirical formula is one of the traditional methods used for predicting ground deformation settlement caused by tunnel excavation. Due to its rationality and simplicity, the Peck formula is widely used for predicting surface subsidence. However, due to its limitations, it is necessary to modify it when predicting surface settlement caused by tunnel excavation in different strata. In this paper, a correction formula for the width coefficient of a tunnel surface settlement slot is derived from the Peck formula by taking into account the theory of strata slip cracks. Values are calculated using the correction formula and compared with measured data to verify the effectiveness of the correction formula. The main conclusions are: (1) The position corresponding to the width of the settlement in the Peck curve is the point where the formation is most prone to slip cracking. (2) In the general shallow buried case, the settlement groove width coefficient K and the internal friction angle φ of the ground satisfy the formula K = 1/tan(45° + φ/2 + a) + b, and the values of parameters a and b reflect the average values of the geometric properties of the tunnel based on the measured data. (3) The prediction of the correction formula is consistent with the measured data, and thus the correction formula can be applied to problems related to the stability of shallow buried tunnels.
Modification of Meso-Micromixing Interaction Reaction Model in Continuous Reactors
Authors: Jiang Junan , Yang Ning , Liu Hanyang , Tang Jianxin , Wang Chenfeng , Wang Rijie , Yang Xiaoxia
Published: May 2023

The yields of chemical reactions are highly dependent on the mixing pattern between reactants. Herein, we report the modification of a meso-micromixing interaction reaction model which is applied in batch reactors by leveraging the flow characteristics in the continuous reactors. Both experimental and model-predicted yields were compared using the classical Villermaux–Dushman method in a self-designed split and recombination reactor. This modified model significantly reduced the error in predicted product yields from approximately 15% to within 3%, compared to a model containing the micromixing term only. The effects of flow rates and reactor structure parameters on mixing performance were analyzed. We found that increasing flow rates and the degree of twist in the mixing element’s grooves, as well as decreasing the cross-sectional area of grooves, improved mixing performance. The optimization of reactor flow rates and structural parameters was achieved by combining Gaussian process regression and Bayesian optimization with the modified model. This approach provided higher target product yields for consecutive reactions, while simultaneously achieving a lower pressure drop in the reactor. Corresponding combinations of reactor parameters were also identified during this process. Our modified model-based optimization methodology can be applied to a diversity of reactors, serving as a reference for the selection of their structure and operational parameters.
An Enhanced Storm Warning and Nowcasting Model in Pre-Convection Environments
Authors: Ma Zheng , Li Zhenglong , Li Jun , Min Min , Sun Jianhua , Wei Xiaocheng , Schmit Timothy J. , Cucurull Lidia
Published: May 2023

A storm tracking and nowcasting model was developed for the contiguous US (CONUS) by combining observations from the advanced baseline imager (ABI) and numerical weather prediction (NWP) short-range forecast data, along with the precipitation rate from CMORPH (the Climate Prediction Center morphing technique). A random forest based model was adopted by using the maximum precipitation rate as the benchmark for convection intensity, with the location and time of storms optimized by using optical flow (OF) and continuous tracking. Comparative evaluations showed that the optimized models had higher accuracy for severe storms with areas equal to or larger than 5000 km2 over smaller samples, and loweraccuracy for cases smaller than 1000 km2, while models with sample-balancing applied showed higher possibilities of detection (PODs). A typical convective event from August 2019 was presented to illustrate the application of the nowcasting model on local severe storm (LSS) identification and warnings in the pre-convection stage; the model successfully provided warnings with a lead time of 1–2 h before heavy rainfall. Importance score analysis showed that the overall impact from ABI observations was much higher than that from NWP, with the brightness temperature difference between 6.2 and 10.3 microns ranking at the top in terms of feature importance.
Establishing the Position and Drivers of the Eastern Andean Treeline with Automated Transect Sampling
Authors: Zelazowski Przemyslaw , Jozefowicz Stefan , Feeley Kenneth J. , Malhi Yadvinder
Published: May 2023

The eastern Andean treeline (EATL) is the world’s longest altitudinal ecotone and plays an important role in biodiversity conservation in the context of land use/cover and climate change. The purpose of this study was to assess to what extent the position of the tropical EATL (9°N–18°S) is in near-equilibrium with the climate, which determines its potential to adapt to climate change. On a continental scale, we have used land cover maps (MODIS MCD12) and elevation data (SRTM) to make the first-order assessment of the EATL position and continuity. For the assessment on a local scale and to address the three-dimensional nature of environmental change in mountainous environments, a novel method of automated delineation and assessment of altitudinal transects was devised and applied to Landsat-based forest maps (GLAD) and fine-resolution climatology (CHELSA). The emergence of a consistent longitudinal gradient of the treeline elevation over half of the EATL extent, which increases towards the equator by ~30 m and ~60 m per geographic degree from the south and north, respectively, serves as a first-order validation of the approach, while the local transects reveal a more nuanced aspect-dependent pattern. We conclude that the applied dual-scale approach with automated mass transect sampling allows for an improved understanding of treeline dynamics.
Cotton Seedling Detection and Counting Based on UAV Multispectral Images and Deep Learning Methods
Authors: Feng Yingxiang , Chen Wei , Ma Yiru , Zhang Ze , Gao Pan , Lv Xin
Published: May 2023

Cotton is one of the most important cash crops in Xinjiang, and timely seedling inspection and replenishment at the seedling stage are essential for cotton’s late production management and yield formation. The background conditions of the cotton seedling stage are complex and variable, and deep learning methods are widely used to extract target objects from the complex background. Therefore, this study takes seedling cotton as the research object and uses three deep learning algorithms, YOLOv5, YOLOv7, and CenterNet, for cotton seedling detection and counting using images at six different times of the cotton seedling period based on multispectral images collected by UAVs to develop a model applicable to the whole cotton seedling period. The results showed that when tested with data collected at different times, YOLOv7 performed better overall in detection and counting, and the T4 dataset performed better in each test set. Precision, Recall, and F1-Score values with the best test results were 96.9%, 96.6%, and 96.7%, respectively, and the R2, RMSE, and RRMSE indexes were 0.94, 3.83, and 2.72%, respectively. In conclusion, the UAV multispectral images acquired about 23 days after cotton sowing (T4) with the YOLOv7 algorithm achieved rapid and accurate seedling detection and counting throughout the cotton seedling stage.
A Minimalist Self-Localization Approach for Swarm Robots Based on Active Beacon in Indoor Environments
Authors: Duan Mengyuan , Lei Xiaokang , Duan Zhongxing , Zheng Zhicheng
Published: May 2023

When performing indoor tasks, miniature swarm robots are suffered from their small size, poor on-board computing power, and electromagnetic shielding of buildings, which means that some traditional localization methods, such as global positioning system (GPS), simultaneous localization and mapping (SLAM), and ultra-wideband (UWB), cannot be employed. In this paper, a minimalist indoor self-localization approach for swarm robots is proposed based on active optical beacons. A robotic navigator is introduced into a swarm of robots to provide locally localization services by actively projecting a customized optical beacon on the indoor ceiling, which contains the origin and the reference direction of localization coordinates. The swarm robots observe the optical beacon on the ceiling via a bottom-up-view monocular camera, and extract the beacon information on-board to localize their positions and headings. The uniqueness of this strategy is that it uses the flat, smooth, and well-reflective ceiling in the indoor environment as a ubiquitous plane for displaying the optical beacon; meanwhile, the bottom-up view of swarm robots is not easily blocked. Real robotic experiments are conducted to validate and analyze the localization performance of the proposed minimalist self-localization approach. The results show that our approach is feasible and effective, and can meet the needs of swarm robots to coordinate their motion. Specifically, for the stationary robots, the average position error and heading error are 2.41 cm and 1.44°; when the robots are moving, the average position error and heading error are less than 2.40 cm and 2.66°.
In-Lab Demonstration of an Underwater Acoustic Spiral Source
Authors: Viegas Ruben , Zabel Friedrich , Silva Antonio
Published: May 2023

Underwater acoustic spiral sources can generate spiral acoustic fields where the phase depends on the bearing angle. This allows estimating the bearing angle of a single hydrophone relative to a single source and implementing localization equipment, e.g., for target detection or unmanned underwater vehicle navigation, without requiring an array of hydrophones and/or projectors. A spiral acoustic source prototype made out of a single standard piezoceramic cylinder, which is able to generate both spiral and circular fields, is presented. This paper reports the prototyping process and the multi-frequency acoustic tests performed in a water tank where the spiral source was characterized in terms of the transmitting voltage response, phase, and horizontal and vertical directivity patterns. A receiving calibration method for the spiral source is proposed and showed a maximum angle error of 3° when the calibration and the operation were carried out in the same conditions and a mean angle error of up to 6° for frequencies above 25 kHz when the same conditions were not fulfilled.
Estimation of Knee Joint Angle from Surface EMG Using Multiple Kernels Relevance Vector Regression
Authors: Li Hui-Bin , Guan Xiao-Rong , Li Zhong , Zou Kai-Fan , He Long
Published: May 2023

In wearable robots, the application of surface electromyography (sEMG) signals in motion intention recognition is a hot research issue. To improve the viability of human–robot interactive perception and to reduce the complexity of the knee joint angle estimation model, this paper proposed an estimation model for knee joint angle based on the novel method of multiple kernel relevance vector regression (MKRVR) through offline learning. The root mean square error, mean absolute error, and R2_score are used as performance indicators. By comparing the estimation model of MKRVR and least squares support vector regression (LSSVR), the MKRVR performs better on the estimation of the knee joint angle. The results showed that the MKRVR can estimate the knee joint angle with a continuous global MAE of 3.27° ± 1.2°, RMSE of 4.81° ± 1.37°, and R2 of 0.8946 ± 0.07. Therefore, we concluded that the MKRVR for the estimation of the knee joint angle from sEMG is viable and could be used for motion analysis and the application of recognition of the wearer’s motion intentions in human–robot collaboration control.
High-Performance Surface Electromyography Armband Design for Gesture Recognition
Authors: Zhang Ruihao , Hong Yingping , Zhang Huixin , Dang Lizhi , Li Yunze
Published: May 2023

Wearable surface electromyography (sEMG) signal-acquisition devices have considerable potential for medical applications. Signals obtained from sEMG armbands can be used to identify a person’s intentions using machine learning. However, the performance and recognition capabilities of commercially available sEMG armbands are generally limited. This paper presents the design of a wireless high-performance sEMG armband (hereinafter referred to as the α Armband), which has 16 channels and a 16-bit analog-to-digital converter and can reach 2000 samples per second per channel (adjustable) with a bandwidth of 0.1–20 kHz (adjustable). The α Armband can configure parameters and interact with sEMG data through low-power Bluetooth. We collected sEMG data from the forearms of 30 subjects using the α Armband and extracted three different image samples from the time–frequency domain for training and testing convolutional neural networks. The average recognition accuracy for 10 hand gestures was as high as 98.6%, indicating that the α Armband is highly practical and robust, with excellent development potential.
Design of 3D Controller Using Nanocracking Structure-Based Stretchable Strain Sensor
Authors: Yang Seongjin , Kim Minjae , Hong Seong Kyung , Kim Suhyeon , Chung Wan Kyun , Lim Geunbae , Jeon Hyungkook
Published: May 2023

In this study, we introduce a novel design for a three-dimensional (3D) controller, which incorporates the omni-purpose stretchable strain sensor (OPSS sensor). This sensor exhibits both remarkable sensitivity, with a gauge factor of approximately 30, and an extensive working range, accommodating strain up to 150%, thereby enabling accurate 3D motion sensing. The 3D controller is structured such that its triaxial motion can be discerned independently along the X, Y, and Z axes by quantifying the deformation of the controller through multiple OPSS sensors affixed to its surface. To ensure precise and real-time 3D motion sensing, a machine learning-based data analysis technique was implemented for the effective interpretation of the multiple sensor signals. The outcomes reveal that the resistance-based sensors successfully and accurately track the 3D controller’s motion. We believe that this innovative design holds the potential to augment the performance of 3D motion sensing devices across a diverse range of applications, encompassing gaming, virtual reality, and robotics.
Theoretical Study of a Closed-Cycle Evaporation System for Seawater Desalination
Authors: Liu Jun , Sun Yong , Zhang Yizhu , Wang Jiaquan
Published: May 2023

This paper presents a numerical study of a closed-cycle evaporation system for the desalination of seawater. The system couples the condensing end of a heat pump with a humidifier, where the air is dehumidified in the heat pump evaporator. First, the mechanism of action of the closed-cycle evaporation system was analyzed from the perspective of heat transfer, and the control equations for the heat and mass transfer of the system were investigated. In addition, a mathematical model of the system was developed and validated. The influence of several important parameters of the air and seawater entering the system on the system’s performance under the design conditions was investigated numerically. The parametric analysis showed that the effect of the seawater mass flow rate on the system’s productivity was not significant. As the air mass flow rate increases, the freshwater production rate increases and then decreases. The output ratio (GOR) of the system was estimated and found to be competitive with other reported HDH systems.
High-Tech Augmentative and Alternative Communication Devices: Observing Children’s Need for Help and Interaction with Caregivers
Authors: Almeida Ivone , Moreira António , Ribeiro Jaime
Published: May 2023

There are many children with disabilities who need specialised devices to communicate and to be understood, which poses an added challenge for their caregivers. This study aims to diagnose the training needs of informal caregivers concerning high-tech devices for augmentative and alternative communication (AAC), to enhance the use of these devices in the home setting. The aim is to study children’s performance and their interaction with caregivers, to improve practices and contribute to reducing technology abandonment at home. Participant observation sessions were carried out in three home settings to describe the interaction between children and their caregivers, as well as to assess the former’s need for assistance in using the Grid3 software when combined with eye-gaze-controlled technology. The findings seem to demonstrate the importance of interactions between caregivers and children for carrying out tasks and improving performance. Therefore, it can be inferred that positive reinforcement is important to foster children’s motivation to overcome difficulties in using such devices, along with corrective feedback. The data suggest the need to promote technology-mediated communicative interaction in all life contexts. It is also possible to infer that the lack of regular device use at home compromises skills development. These findings have contributed to the planning and implementation of parental training intervention regarding using assistive technology for augmentative and alternative communication.
The Judicial Geography of Patent Litigation in Germany: Implications for the Institutionalization of the European Unified Patent Court
Authors: Zipf Marius , Glückler Johannes , Khuchua Tamar , Lazega Emmanuel , Lachapelle François , Hoffmann Jakob
Published: May 2023

The Unified Patent Court (UPC) will be the pillar of a unified European patent enforcement system. Crucial to its success will be the harmonization of geographical variation in national jurisdictions. Germany offers a unique opportunity to explore such harmonization, as plaintiffs can choose between twelve regional courts to file a patent suit, resulting in different patent court practices within the same jurisdiction. Adopting a legal geography perspective, we examine the appellate process as a mechanism that reconciles regional variation in court practices. Based on more than 100 decisions from 34 contentious litigations that went through all instances up to the Federal Court of Justice between 2005 and 2019, we find that decision reversals, case citations and guiding principles are important tools to improve error correction and judicial consistency within an IP system. We see these instruments as crucial for national harmonization also in the upcoming European framework.
Air Quality Impacts on the Giant Panda Habitat in the Qinling Mountains: Chemical Characteristics and Sources of Elements in PM2.5
Authors: Wu Junhua , Chen Yiping , Zhao Yan , Zhang Yong , Liu Wangang , Wang Jin , Wang Qiyuan , He Xiangbo
Published: May 2023

The wild giant panda habitat is inaccessible and far away from the main areas of human activity, so environmental pollutants entering the habitat are mainly the result of external migration and spread through the atmospheric advection and diffusion processes and particulate matter deposition. To research the variation, transmission route, chemical characteristics, and source of PM2.5 in the habitat of wild giant pandas, we set up a PM2.5 sampling point near the Shaanxi Foping National Nature Reserve (SFNNR), which is the area with the highest population density of wild giant pandas in the Qinling Mountains. The 12-month average concentration of PM2.5 was 11.3 ± 7.9 μg/m3 from July 2021 to June 2022, and the 12-month average concentration did not exceed the limit value set in the standard. In the results of our analysis of element concentrations, As and Pb were much lower than the limit standard. Si, S, P, and Cl accounted for 99.60% of nonmetallic elements, while the proportion of the six metallic elements, Na, Mg, Al, K, Ca, and Fe, was 96.27%. According to the analysis results of enrichment factor (EF) and pollutant emission sources, there were four sources for the total elements in PM2.5, which were mainly distributed in the areas around the reserve. These included dust, coal combustion, biomass burning, and traffic-related emissions, which contributed 55.10%, 24.78%, 11.91%, and 8.22% of the total element mass in PM2.5, respectively. Additionally, Pb, Cu, Zn, As, Sc, Co, Ga, Mg, and, especially, Se were severely affected by human activities (coal burning, biomass burning, and traffic-related emissions). In the villages and towns around the wild giant panda habitat, the majority of energy for cooking and heating comes from coal and biomass burning, and older vehicles with high emissions are used more frequently. Therefore, to better protect the health of and reduce the impact of environmental pollution on wild giant pandas, we put forward relevant recommendations, including upgrading the energy structure of towns and villages near the habitat to increase the proportion of clean energy, such as photovoltaic power generation, natural gas, etc.; decreasing the combustion of coal and biomass; encouraging the upgrading of agricultural diesel machines and older vehicles used in these areas; and setting limits on vehicle emissions in areas surrounding the habitat.
Analysis of Wind Turbine Equipment Failure and Intelligent Operation and Maintenance Research
Authors: Peng Han , Li Songyin , Shangguan Linjian , Fan Yisa , Zhang Hai
Published: May 2023

Power generation from wind farms is growing rapidly around the world. In the past decade, wind energy has played an important role in contributing to sustainable development. However, wind turbines are extremely susceptible to component damage under complex environments and over long-term operational cycles, which directly affects their maintenance, reliability, and operating costs. It is crucial to realize efficient early warning of wind turbine failure to avoid equipment breakdown, to prolong the service life of wind turbines, and to maximize the revenue and efficiency of wind power projects. For this purpose, wind turbines are used as the research object. Firstly, this paper outlines the main components and failure mechanisms of wind turbines and analyzes the causes of equipment failure. Secondly, a brief analysis of the cost of wind power projects based on equipment failure is presented. Thirdly, the current key technologies for intelligent operation and maintenance (O&M) in the wind power industry are discussed, and the key research on decision support systems, fault diagnosis models, and life-cycle costs is presented. Finally, current challenges and future development directions are summarized.
Evolution and Parametric Analysis of Concrete Temperature Field Induced by Electric Heating Curing in Winter
Authors: Han Jianyong , Liu Lin , Zuo Congbing , Wang Haoshuang , Lin Fenglai , Zhao Yue , Li Tianliang , Liu Dong
Published: May 2023

Electric heat treatment is a widely used concrete curing method during the winter. Through direct and indirect heat exchange, the electric heating system tracks and controls the temperature of the heating medium based on a positive temperature coefficient (PTC) effect. In this study, to standardize the application of this treatment in the winter curing of concrete, the thermal energy conversion of an electric heating system and the heat-transfer characteristics of concrete have been studied. Based on the theoretical derivation, a calculation model of the relationship between the thermal energy of the electric heating system and the temperature of the concrete is established. The model is verified using the concrete heating and curing test results. The numerical analysis program COMSOL is used to analyze the effects of various factors on the concrete temperature field, including the electric heating power (e.g., the surface temperature of the electric heating system), concrete casting temperature, thermal conductivity, and heat release coefficient. The results show that decreasing the surface exothermic coefficient and increasing the heating temperature will significantly increase the peak temperature of the concrete. When the heat source temperature increases by 20 °C, the peak temperature could increase by approximately 13 °C. When the heating stops, the concrete volume increases temporarily, particularly in the region where the heating cable is buried. Consequently, an excessive heating power increase may cause cracks on the concrete surface. Compared with the factors of thermal conductivity and surface exothermic coefficient, the ambient temperature has the most significant effect on the concrete cooling rate when the heating stops. When the ambient temperature decreases by −20 °C, the cooling rate of concrete increases by 0.72 °C/h. The role of concrete insulation materials needs to be strengthened to reduce cooling rates during power outages and form removal. The findings from the study provide industry practitioners with a comprehensive guide regarding the specific applications of the electric heating system in early-age concrete curing.
A Study of Vulnerable Road Users’ Behaviors Using Schema Theory and the Perceptual Cycle Model
Authors: Liu Zhengrong , Wu Jianping , Yousaf Adnan , McIlroy Rich C. , Wang Linyang , Liu Mingyu , Plant Katherine L. , Stanton Neville A.
Published: May 2023

China is currently in a rapid urbanization phase, and road traffic accidents occur frequently, with vulnerable road users often being easily injured. Traditional road traffic safety research often focuses on environmental and structural safety issues or considers human factors as the cause of accidents. This study organized 30 vulnerable road users to travel in a quadrangular road area in the Wudaokou area of Beijing, collected language data from the subjects for analysis, and attempted to apply schema theory and the perceptual cycle model from the field of cognitive psychology to analyze the perception and decision-making processes of vulnerable road users, thus discovering accident risks in the traffic environment and their underlying causes from the perspective of vulnerable road users. The study found that factors such as disorderly placement of shared bicycles, food delivery vehicles occupying the road, damaged road infrastructure, and unreasonable road design affect traffic safety and order, and proposes targeted improvement suggestions.