bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of the Properties of Epoxy Resins Containing Various Trifluoromethyl Groups with Low Dielectric Constant
Authors: Zhang Yurong , Lin Haidan , Dong Kai , Tang Shasha , Zhao Chengji
Published: June 2023

A series of epoxy resins containing various trifluoromethyl groups were synthesized and thermally cured with diaminodiphenylmethane (DDM) and aminophenyl sulfone (DDS). All epoxy resins exhibited excellent thermal stability with the glass transition temperatures of above 128 °C and 5% weight loss temperatures of above 300 °C. DDS-cured epoxy resins possessed higher thermal stability than that of DDM-cured epoxy resins, while DDM-cured epoxy resins showed better mechanical, dielectric, and hydrophobic properties. Additionally, DDM-cured epoxy resins with different locations and numbers of trifluoromethyl groups showed flexural strength in the range of 95.55~152.36 MPa, flexural modulus in the range of 1.71~2.65 GPa, dielectric constant in the range of 2.55~3.05, and water absorption in the range of 0.49~0.95%. These results indicate that the incorporation of trifluoromethyl pendant groups into epoxy resins can be a valid strategy to improve the dielectric and hydrophobic performance.
Formulation and Characteristics of Edible Oil Nanoemulsions Modified with Polymeric Surfactant for Encapsulating Curcumin
Authors: Chiang Tzu-Chi , Chang Jia-Yaw , Chou Tzung-Han
Published: June 2023

Curcumin (Cur) is a beneficial phytochemical with numerous health advantages. However, its limited solubility in oil and poor stability hinder its potential for biomedical applications. In this study, we employed a mixture of food-grade Tween 60, a polymeric surfactant, and Span 60 to adjust the hydrophilic lipophilic balance number (HLBt) and prepared nanoemulsions (NEs) of coconut oil (Cc oil) as carriers for Cur. The effects of HLBt values, surfactant-to-oil ratio, and oil ratio on the physicochemical characteristics of the food-grade oil-NEs were investigated using dynamic light scattering, transmission electron microscopy, differential scanning calorimetry, fluorescence polarization spectroscopy, and viscometry. Increasing the addition ratio of Tween 60 in the NEs, thereby increasing the HLBt, resulted in a reduction in NE size and an improvement in their storage stability. The temperature and size of the phase transition region of the NEs decreased with increasing HLBt. NEs with higher HLBt exhibited a disordering effect on the intra-NE molecular packing of Cc oil. NEs with high HLBt displayed low viscosity and demonstrated nearly Newtonian fluid behavior, while those with lower HLBt exhibited pseudoplastic fluid behavior. Cur was effectively encapsulated into the Cc oil-NEs, with higher encapsulation efficiency observed in NEs with higher HLBt values. Furthermore, the Cur remaining activity was significantly enhanced through encapsulation within stable NEs. The biocompatibility of the Cc oil-NEs was also demonstrated in vitro. In summary, this study highlights the preparation of stable NEs of Cc oil by adjusting the HLBt using Tween 60, facilitating effective encapsulation of Cur. These findings provide valuable insights for the development of Cur carriers with improved solubility, stability, and bioavailability.
Antifouling and Water Flux Enhancement in Polyethersulfone Ultrafiltration Membranes by Incorporating Water-Soluble Cationic Polymer of Poly [2-(Dimethyl amino) ethyl Methacrylate]
Authors: Asif Khan Raja Muhammad , Ahmad Nasir M. , Nasir Habib , Mahmood Azhar , Iqbal Mudassir , Janjua Hussnain A.
Published: June 2023

Novel ultrafiltration (UF) polymer membranes were prepared to enhance the antifouling features and filtration performance. Several ultrafiltration polymer membranes were prepared by incorporating different concentrations of water-soluble cationic poly [2-(dimethyl amino) ethyl methacrylate] (PDMAEMA) into a homogenous casting solution of polyethersulfone (PES). After adding PDMAEMA, the effects on morphology, hydrophilicity, thermal stability, mechanical strength, antifouling characteristics, and filtration performance of these altered blended membranes were investigated. It was observed that increasing the quantity of PDMAEMA in PES membranes in turn enhanced surface energy, hydrophilicity, and porosity of the membranes. These new modified PES membranes, after the addition of PDMAEMA, showed better filtration performance by having increased water flux and a higher flux recovery ratio (FRR%) when compared with neat PES membranes. For the PES/PDMAEMA membrane, pure water flux with 3.0 wt.% PDMAEMA and 0.2 MPa pressure was observed as (330.39 L·m−2·h−1), which is much higher than that of the neat PES membrane with the value of (163.158 L·m−2·h−1) under the same conditions. Furthermore, the inclusion of PDMAEMA enhanced the antifouling capabilities of PES membranes. The total fouling ratio (TFR) of the fabricated PES/PDMAEMA membranes with 3.0 wt.% PDMAEMA at 0.2 MPa applied pressure was 36 percent, compared to 64.9 percent for PES membranes.
Influence of Dielectric Barrier Discharge Plasma Treatment on Corn Starch Properties
Authors: Goiana Mayara L. , Fernandes Fabiano A. N.
Published: June 2023

This study evaluated the effects of dielectric barrier discharge (DBD) plasma technology on some physicochemical and structural properties of corn starch. Amylose content, solubility, water absorption index, turbidity, structural relationships, and surface morphology were measured at 100, 200, and 300 Hz excitation frequencies and at 10 and 20 min exposure times. The plasma treatment at 200 Hz and 20 min promoted the most significant modifications in amylose content, solubility, the water absorption index, and surface morphology. Turbidity did not change significantly. The surface of the granule became smoother with the presence of pores. Slight changes were observed in the ordered structure of starch. Plasma changed several physicochemical properties, significantly decreasing the amylose to amylopectin ratio. Plasma treatment at 200 Hz is recommended to increase the amylopectin content in starches.
Non-Carcinogenic Risk Assessment for Heavy Metals in the Soil and Rice in the Vicinity of Dabaoshan Mine, South China
Authors: Zhao Huarong , Shi Kangming , Qin Jianqiao , Ren Zikang , Yang Guoliang
Published: June 2023

Heavy-metal pollution has attracted wide attention in recent years. The problem of heavy-metal pollution in the vicinity of the Dabaoshan mine, the largest polymetallic mine in South China, has attracted widespread attention. In this study, 38 samples of rice and paddy soil near the Dabaoshan mine were collected. The physical and chemical properties of the soil, including Cu, Cd, Zn, Pb, and Ni levels in the soil and rice, were analyzed. The heavy-metal baseline in paddy soil was analyzed by a normal Q–Q plot. The bioaccumulation factor of the rice was calculated. The non-carcinogenic risk of heavy metals was evaluated by calculating the hazard quotient (HQ). Threshold values of Cu, Cd, Zn, Pb, and Ni were 35.01, 0.51, 70.94, 59.78, and 16.34 mg/kg, respectively. The threshold values of Cu, Zn, and Pb were higher than the background value and lower than the secondary value of China’s soil environmental quality standard. The threshold value of Cd was higher than both the background value and the secondary value of China’s soil environmental quality standard. There was no significant threshold value for Ni in soil. The bioaccumulation factors of Cd, Zn, and Ni were straw > rice > husk. The bioaccumulation factors of Cu and Pb were straw > husk > rice. The HQ of Cd showed that the values for both adults and children were greater than 1, and the HQ for children was higher than that for adults. The HQs of Cu, Pb, Zn, and Ni were all less than 1. This indicated that Cu, Cd, Zn, and Pb pollution had occurred in the area, and that the Cd pollution was more serious. Therefore, it is necessary to strengthen land management, carry out the treatment of soil heavy metal pollution, and reduce the health risks of heavy metals in the study area.
Torrefaction under Different Reaction Atmospheres to Improve the Fuel Properties of Wheat Straw
Authors: Torres Ramos Ricardo , Valdez Salas Benjamín , Montero Alpírez Gisela , Coronado Ortega Marcos A. , Curiel Álvarez Mario A. , Tzintzun Camacho Olivia , Beleño Cabarcas Mary Triny
Published: June 2023

This study aimed to produce biochar with an energy value in the range of sub-bituminous carbon by investigating the effect of oxidative and non-oxidative torrefaction on the torrefaction yield and fuel properties of wheat straw. Three independent variables were considered at different levels: temperature (230, 255, 280, 305 °C), residence time (20, 40, 60 min), and reaction atmosphere (0, 3, 6 vol% O2; N2 balance); and three dependent variables: mass yield, energy yield, and percentage increase in higher heating value (HHV). The results showed that it is possible to produce a sub-bituminous carbon type C biochar using oxidative torrefaction, significantly reducing time and temperature compared with non-oxidative torrefaction. The optimum torrefaction conditions were 287 °C–20 min–6.0% O2, which increased the HHV of wheat straw from 13.86 to 19.41 MJ kg−1. The mass and energy yields were 44.11 and 61.78%, respectively. The physicochemical and fuel properties of the obtained biochar were improved compared with the raw biomass. The atomic O/C ratio was reduced from 1.38 to 0.86. In addition, the hydroxyl groups in the lignocellulosic structure decreased and the hemicellulose content decreased from 26.08% to 1.61%. This improved grindability, thermal stability, porosity, and hydrophobicity.
Effect of Mold Flow Channel Parameters on Gas-Assisted Extrusion of Medical Microtubules
Authors: Zhang Xiaohui , Huang Xingyuan , Liu Bin , Jiang Shiyu , Ren Shaoyi
Published: June 2023

Due to the complexity of mold flow channel parameters, they have a significant impact on medical microtubule forming quality during the gas-assisted extrusion process. In this paper, the influence mechanism of mold flow channel parameters on medical microtubule forming quality is investigated. First, the multiphase flow model of the medical microtubule gas-assisted extrusion process is established. Then, the numerical solution of medical microtubule extrusion is presented based on Polyflow finite element software. Further, the medical microtubule size, morphology, velocity, pressure, and first normal stress difference under different mold flow channel parameters are compared and analyzed. Finally, the experimental platform for gas-assisted extrusion is built, and the correctness of the numerical simulation is verified by the extrusion experiment. The simulation and experimental results show that under the 15–5 condition, the inner radius, outer radius, and wall thickness of the microtubule are closer to ideal values, and the forming quality is better than other parameters. As the ratio of the gas-assisted to non-gas-assisted sections increases, the gas effect becomes more intense, and the shrinkage of the microtube increases. In the gas-assisted section, the wall thickness and outer radius of the microtubes increase first and then decrease, and they stay the same near the exit section. This reveals that gas-assisted forming technology can effectively eliminate extrusion swelling.
CFD Modeling of Phase Change during the Flashing-Induced Instability in a Natural Circulation Circuit
Authors: Liao Yixiang , Lucas Dirk
Published: June 2023

Flashing-induced instability (FII) has a significant impact on the safe operation of a natural circulation circuit, a phenomenon frequently encountered in the cooling systems of advanced light water reactors. While one-dimensional system codes are commonly used for the engineering design and safety analysis of FII, there is a strong academic interest in understanding the underlying physical mechanisms. To address this, high-resolution computational fluid dynamics (CFD) simulations serve as a valuable tool. However, the current state of CFD modeling for two-phase flows with phase change, which are particularly highly transient fluctuating flashing flows, is still in its early stages of development. In this study, we establish a CFD model that focuses on interphase heat transfer to analyze the phase change during FII. By incorporating experimental data from the literature, we investigate the transient flow field and thermodynamic behavior in the riser of the GENEVA test facility. The study provides valuable insights into the non-equilibrium and interfacial transfer phenomena during the phase change as well as the effect of high-frequency fluctuation. Additionally, we discuss in detail the challenges associated with FII modeling and the limitations of the current model. We also provide suggestions for potential improvements in future numerical studies. The results show that the thermal phase change and heat transfer coefficient model adopted for the simulation reasonably captures the evaporation and condensation process. However, it tends to under-predict the evaporation rate, which results in a larger pressure drop through the riser. The observation that the void fraction close to the wall is higher than that in the riser center evidences that the reliable modeling of bubble size distribution as well as the inclusion of non-drag forces are important for predicting the transverse void distribution. Furthermore, it reveals that both the temperature and pressure change in an FII, and their effects on phase change should be taken into account simultaneously.
Reaction–Diffusion Process for Hydrogels with a Tailored Layer Structure
Authors: Wang Yongliang , Xu Yaxin , Wang Yunfei , Li Baoqiang , Wang Chunfeng , Han Zhidong , Weng Ling
Published: June 2023

The architecture of hydrogel composites results in not only synergistic property enhancement but also superior functionality. The reaction–diffusion (RD) process is acommon phenomenon throughout nature which induced ordered structure on a length scale from microscopic to macroscopic. Different from commonly used inorganic salts or oppositely charged nanoparticles for the RD process, a modified RD process was used for layered chitosan hydrogel (L-CH) and layered magnetic chitosan hydrogel (L-MCH). During the modified RD process reported in this paper, the protonated chitosan (CS-NH3+) with iron ions (Fe3+ and Fe2+) was used as an inner-reactant and hydroxide ion (-OH−) was used as an out-reactant. The protonated chitosan (CS-NH3+) not only played the role of an inner-reactant but also the reaction medium which controlled the diffusion behavior of the out-reactant (-OH−). A series of ordered layers were constructed and the ordered layers were parallel with the longitudinal axis. The layer width of L-CH and L-MCH can be tailored by varying interval time T. The mean layer width of L-MCH increased from 50 ± 5.8 μm to 90 ± 6.4 μm when the interval time T increased from 2 min to 5 min. The tailored layer structure of L-CH and L-MCH obeyed the time law and spacing law, which declared that the L-CH and L-MCH were constructed via the reaction–diffusion process. We also show that the tailored layer structure endows hydrogel with enhanced mechanical properties, especially toughness. The yield strength of magnetic chitosan hydrogel was improved significantly (from 95.1 ± 7.6 kPa to 401.7 ± 12.1 kPa, improved by about 4 times) when 10 wt. % magnetite nanoparticles were involved. The enhancement of the mechanical propertieswas due to a physical crosslinking effect of magnetite nanoparticles on chitosan. For L-MCH, the probe displacement reached 28.93 ± 2.6 mm when the rupture occurred, which was as high as 284.7% compared with that of the non-layered hydrogel. The tailor-made hydrogels might be possible for application as a tough implantable scaffold.
Numerical Simulation of Pore Pressure Change Caused by Hydrocarbon Generation in Chezhen Sag and Its Influence on Hydrocarbon Accumulation
Authors: Wang Mingwen , Luo Gang , Qin Feng , Liao Zonghu , Zhou Shuhong , Yang Nianfa
Published: June 2023

The pore fluid pressure is important for the generation, migration, and accumulation of hydrocarbons. The Chezhen Sag region in the Bohai Bay Basin is typically characterized by pore fluid overpressure, which is the difference between the pore fluid pressure and the hydrostatic pore pressure. The formation mechanisms of pore overpressure and the accumulation regularity of the “upper source-lower reservoir” type in this region remain unknown. In order to investigate these problems, based on the existing seismic, logging data, and regional tectonic stress environment, we established a two-dimensional finite element model to simulate the fluid–solid coupling processes in the Chegu 25 block of the Chezhen depression. We calculated the abnormal overpressure generated at the source rock during hydrocarbon generation and the processes of hydrocarbon migration and accumulation along the faults and analyzed the dynamic conditions of the hydrocarbon downward accumulation. The results showed that overpressure could accelerate the migration of hydrocarbon and improve the efficiency of hydrocarbon accumulation. When the overpressure was too large, tensile fractures and shear fractures could occur, resulting in hydrocarbon dissipation, and changing the results of the oil and gas accumulation. The overpressure at the source rock was mainly caused by hydrocarbon generation, while the overpressure at the reservoir was primarily created by unbalanced compaction. As the dominant channel of hydrocarbon migration that exists, overpressure will change the direction and path of hydrocarbon migration in the fault. Therefore, the high permeability of the fault and the existence of pore fluid overpressure can explain the “upper source-lower reservoir” hydrocarbon accumulation model strongly explained the high permeability of faults and the presence of overpressure. The simulated overpressure results were also in good agreement with the mud weight equivalent overpressure and the drill stem tests (DSTs).
3D Imaging of On-Chip Porous Medium Using X-ray Laminography: Application to Reactive Flow Dissolution at Small Scales
Authors: Morais Sandy , Lecoutre Carole , Philippot Gilles , Aubert Guillaume , Nguyen Olivier , Cario Anaïs , Vidal Emeline , Campbell Zachary S. , Garrabos Yves , Azaroual Mohamed , Helfen Lukas , Bernard Dominique , Marre Samuel
Published: June 2023

In this study, X-ray laminography is used to monitor the evolution of a model 3D packed bed porous medium on a chip (micromodels) undergoing reactive flows. The obtained 3D images are used to compute the fluid flow patterns and develop insights into dissolution mechanisms. This study is a first proof of concept study, with controlled micromodels, and could later be extended towards deeper understanding of the dissolution and precipitation processes occurring in porous media at the microscale, mechanisms which are relevant to many industrial areas including catalysis, geochemistry, energy, and waste storage in deep geological formations, etc.
Fatigue Crack Propagation Behavior and Life Prediction of Welded Joints of SMA490BW Steel for Bogies
Authors: Xu Xingyuan , Xie Liyang , Zhou Song , An Jinlan , Huang Yanqing , Li Dongxia
Published: June 2023

In this paper, the precrack propagation behavior of an SMA490BW welded joint in the core zone and heat-affected zone was analyzed through experiments based on the FRANC 3D and ABAQUS cosimulation method, and life prediction of these cracks was also investigated. The results show that the experimental crack propagation path and crack propagation rate in the weld core zone and heat-affected zone agree well with the simulation results, with a small relative error. The life span of the prefabricated crack in the heat-affected zone was higher than that in the core zone. Furthermore, regarding the life prediction results for the two samples, the relative error obtained using FRANC 3D was about 5%, which was verified using the method of joint simulation of crack propagation behavior in the zone simulation and their life prediction with accurate feasibility.
A Woman’s History: A Lifetime of Practising Yiguandao—The Senior Leader of the Subdivision Baoguang Chongzheng
Authors: Shen Yeh-Ying
Published: June 2023

This paper examines a female Yiguandao (一貫道) leader’s lifelong history of practising the faith: Huang Shih-Yen (黃世妍, 1940–), the Elder (qianren 前人) of the subdivision Baoguang Chongzheng (寶光崇正). The journey begins with her conversion to Yiguandao and devotion to its religious practices, followed by her assuming leadership of a subdivision and expanding overseas proselytising missions. Female leaders are not uncommon in modern and contemporary Yiguandao; however, Huang presents a different image from that of conventional female leadership in popular Chinese religions. First, unlike most female leaders who refuse marriage, Huang is a wife and mother; she has shouldered both sacred and secular duties. Second, when she gained leadership, her husband, who was also an Elder of Baoguang Chongzheng, followed and assisted her in managing the temple affairs. Third, she was personally and actively involved in missionary outreach rather than being a spiritual mentor. The materials used to investigate Huang’s life history were predominantly oral history and my own participant observations. This paper illustrates that women’s contributions to religious practices may be on par with their male counterparts, but their stories have been overlooked.
The Rothko Chapel: Profane or Sacred Space?
Authors: Allen Mark
Published: June 2023

Despite the atheism of renowned abstract expressionist painter Mark Rothko, the artist was commissioned by Christians to create a sacred space that was originally intended to be used by religious believers: the Rothko Chapel in Houston, Texas. The project started out as a collaboration between Rothko and another atheist: famed architect Phillip Johnson, who designed several prominent religious spaces throughout his distinguished career. While Johnson removed himself from the Chapel project early on, Rothko would have carried his conceptual vision all the way to the end if it were not for his tragic suicide just prior to the Chapel’s completion. Using as a guide the criteria for sacred space set forth in the classic work The Sacred and The Profane by famed historian Mircea Eliade, I will consider the question of how a religious space designed by non-believers can be rightly considered sacred, as well as ways in which it falls short.
Thermodynamic Approach to the Discount Rate and Discounted Cash Flow Method
Authors: Dobija Mieczysław , Renkas Jurij
Published: June 2023

Current theories of the discount rate have a theoretical basis focused on risk; risk-free rate and risk premium. The basic component of the discount rate, the risk-free rate as purely empirical has a natural infirmity which consequently weakens the final theory. Similarly, the risk premium category is not theoretically perfect. The fundamental shortcoming is that the theory of the discount rate does not relate to fundamental knowledge of capital and the natural rate of its potential growth. Therefore, the purpose of the discussion is to justify the discount rate structure with the constant of potential growth of capital; a = 0.08 [1/year] as the main component. It is proven that the theory of the discount rate is linked to the essence of time and the pace of its passage and is an essential component of the capital–labor–time triad.
2D-DOA Estimation in Multipath Using EMVS Rectangle Array
Authors: Zhang Zhe , Zhang Lei , Wang Han , Shi Junpeng
Published: June 2023

Electromagnetic vector sensor (EMVS) arrays bring an epochal opportunity for direction finding, as they enable the estimation of two-dimensional direction of arrival (2D-DOA) and polarization characteristics. In this paper, we revisit the 2D-DOA estimation problem in an EMVS rectangle array under multipath propagation. An improved subspace estimator is proposed, which addresses the rank-deficit problem through matrix arrangement, and the 2D-DOA and polarization parameters are estimated via combining the normalized vector cross-product with the least squares method. Our proposed method is suitable for a single snapshot scenario and offers superior accuracy compared to existing methods. To validate its effectiveness, several numerical simulations have been designed and conducted.
Enhancing Remote Sensing Image Super-Resolution Guided by Bicubic-Downsampled Low-Resolution Image
Authors: Chung Minkyung , Jung Minyoung , Kim Yongil
Published: June 2023

Image super-resolution (SR) is a significant technique in image processing as it enhances the spatial resolution of images, enabling various downstream applications. Based on recent achievements in SR studies in computer vision, deep-learning-based SR methods have been widely investigated for remote sensing images. In this study, we proposed a two-stage approach called bicubic-downsampled low-resolution (LR) image-guided generative adversarial network (BLG-GAN) for remote sensing image super-resolution. The proposed BLG-GAN method divides the image super-resolution procedure into two stages: LR image transfer and super-resolution. In the LR image transfer stage, real-world LR images are restored to less blurry and noisy bicubic-like LR images using guidance from synthetic LR images obtained through bicubic downsampling. Subsequently, the generated bicubic-like LR images are used as inputs to the SR network, which learns the mapping between the bicubic-like LR image and the corresponding high-resolution (HR) image. By approaching the SR problem as finding optimal solutions for subproblems, the BLG-GAN achieves superior results compared to state-of-the-art models, even with a smaller overall capacity of the SR network. As the BLG-GAN utilizes a synthetic LR image as a bridge between real-world LR and HR images, the proposed method shows improved image quality compared to the SR models trained to learn the direct mapping from a real-world LR image to an HR image. Experimental results on HR satellite image datasets demonstrate the effectiveness of the proposed method in improving perceptual quality and preserving image fidelity.
Investigation into the Affect of Chemometrics and Spectral Data Preprocessing Approaches upon Laser-Induced Breakdown Spectroscopy Quantification Accuracy Based on MarSCoDe Laboratory Model and MarSDEEP Equipment
Authors: Liu Ziyi , Li Luning , Xu Weiming , Xu Xuesen , Cui Zhicheng , Jia Liangchen , Lv Wenhao , Shen Zhihui , Shu Rong
Published: June 2023

As part of China’s Tianwen-1 Mars mission, the Mars Surface Composition Detector (MarSCoDe) instrument on the Zhurong rover adopts laser-induced breakdown spectroscopy (LIBS) to perform chemical component detection of the materials on the Martian surface. However, it has always been a challenging issue to achieve high accuracy in LIBS quantification. This study investigated the effect of chemometrics and spectral data preprocessing approaches on LIBS quantification accuracy based on different chemometrics algorithms and diverse preprocessing methods. A total of 2340 LIBS spectra were collected from 39 kinds of geochemical samples by a laboratory duplicate model of the MarSCoDe instrument. The samples and the MarSCoDe laboratory model were placed in a simulated Martian atmosphere environment based on equipment called the Mars-Simulated Detection Environment Experiment Platform (MarSDEEP). To quantify the concentration of MgO in the samples, we employed two common LIBS chemometrics; i.e., partial least squares (PLS) and a back-propagation neural network (BPNN). Meanwhile, in addition to necessary routine preprocessing such as dark subtraction, we used five specific preprocessing approaches, namely intensity normalization, baseline removal, Mg-peak wavelength correction, Mg-peak feature engineering, and concentration range reduction. The results indicated that the performance of the BPNN was better than that of the PLS and that the preprocessing of Mg-peak wavelength correction had the most prominent effect to improve the quantification accuracy. The results of this study are expected to provide inspiration for the processing and analysis of the in situ LIBS data acquired by MarSCoDe on Mars.
Evaluating Gait Stability and Muscle Activation in Different Hand Holding Conditions Using the Robotic Walker-mTPAD
Authors: Jacobs Malka , Stramel Danielle Marie , Shair Mayyada , Agrawal Sunil K.
Published: June 2023

While walkers are used as mobility aids for different gait impairments, little is known about the factors that affect the performance of such aids. Therefore, we investigated the impact of arm-holding conditions on gait stability and muscle activation. We used surface electromyography (sEMG) sensors on specific arm and leg muscles while the users took laps with a robotic walker, the mobile Tethered Pelvic Assist Device (mTPAD), on an instrumented mat. Eleven participants without gait disorders walked with and without a 10% body weight (BW) force applied on the pelvis in the following three configurations: (i) while gripping the walker’s frame, (ii) while using an armrest with their arms at a 90∘ angle, and (iii) while using an armrest with their arms at a 130∘ angle for 5 min each. Our results showed that when applying a force, the users changed their gait to increase stability. We also discovered differences in muscle activation based on the user’s specific arm conditions. Specifically, the 130∘ condition required the least muscle activation, while gripping the walker’s frame increased specific muscle activation compared to 90∘ and 130∘. This study is the first to evaluate how arm-holding and external loading conditions alter gait and muscle activations using the mTPAD.
A Low-Cost Measurement Methodology for LiDAR Receiver Integrated Circuits
Authors: Joo Ji-Eun , Choi Shinhae , Chon Yeojin , Park Sung-Min
Published: June 2023

This paper presents a test methodology to facilitate the measuring processes of LiDAR receiver ICs by avoiding the inherent walk error issue. In a typical LiDAR system, a costly laser diode driver emits narrow light pulses with fast rising edges, and the reflected pulses from targets enter an optical detector followed by an analog front-end (AFE) circuit. Then, the received signals pass through the cascaded amplifiers down to the time-to-digital converter (TDC) that can estimate the detection range. However, this relatively long signal journey leads to the significant decline of rising-edge slopes and the output pulse spreading, thus producing inherent walk errors in LiDAR receiver ICs. Compensation methods requiring complex algorithms and extra chip area have frequently been exploited to lessen the walk errors. In this paper, however, a simpler and lower-cost methodology is proposed to test LiDAR receiver ICs by employing a high-speed buffer and variable delay cells right before the TDC. With these circuits, both START and STOP pulses show very similar pulse shapes, thus effectively avoiding the walk error issue. Additionally, the time interval between two pulses is easily determined by varying the number of the delay cells. Test chips of the proposed receiver IC implemented in a 180-nm CMOS process successfully demonstrate easier and more accurate measurement results.
Metric Learning in Histopathological Image Classification: Opening the Black Box
Authors: Amato Domenico , Calderaro Salvatore , Lo Bosco Giosué , Rizzo Riccardo , Vella Filippo
Published: June 2023

The application of machine learning techniques to histopathology images enables advances in the field, providing valuable tools that can speed up and facilitate the diagnosis process. The classification of these images is a relevant aid for physicians who have to process a large number of images in long and repetitive tasks. This work proposes the adoption of metric learning that, beyond the task of classifying images, can provide additional information able to support the decision of the classification system. In particular, triplet networks have been employed to create a representation in the embedding space that gathers together images of the same class while tending to separate images with different labels. The obtained representation shows an evident separation of the classes with the possibility of evaluating the similarity and the dissimilarity among input images according to distance criteria. The model has been tested on the BreakHis dataset, a reference and largely used dataset that collects breast cancer images with eight pathology labels and four magnification levels. Our proposed classification model achieves relevant performance on the patient level, with the advantage of providing interpretable information for the obtained results, which represent a specific feature missed by the all the recent methodologies proposed for the same purpose.
A Federated Attention-Based Multimodal Biometric Recognition Approach in IoT
Authors: Lin Leyu , Zhao Yue , Meng Jintao , Zhao Qi
Published: June 2023

The rise of artificial intelligence applications has led to a surge in Internet of Things (IoT) research. Biometric recognition methods are extensively used in IoT access control due to their convenience. To address the limitations of unimodal biometric recognition systems, we propose an attention-based multimodal biometric recognition (AMBR) network that incorporates attention mechanisms to extract biometric features and fuse the modalities effectively. Additionally, to overcome issues of data privacy and regulation associated with collecting training data in IoT systems, we utilize Federated Learning (FL) to train our model This collaborative machine-learning approach enables data parties to train models while preserving data privacy. Our proposed approach achieves 0.68%, 0.47%, and 0.80% Equal Error Rate (EER) on the three VoxCeleb1 official trial lists, performs favorably against the current methods, and the experimental results in FL settings illustrate the potential of AMBR with an FL approach in the multimodal biometric recognition scenario.
The Impact of Harvesting Height on Farmers’ Musculoskeletal Tissue
Authors: Wang Chun-Yao , Hsu Ying-Fang , Chuang Chi-Yu , Hung Po-Chen , Huang Hsiao-Chien , Chen Chiou-Jong , Yang Shinhao
Published: June 2023

This study aimed to examine whether different agricultural work patterns may cause MSDs in different body areas and assess their severity. In previous studies, musculoskeletal disorders (MSDs) have been recognized as an occupational disease in agricultural workers. However, not all MSDs resulting from agriculture occur in the same body areas or have similar severity. This study conducted a questionnaire survey to inquire about the body areas and severity of MSDs among fruit farmers. A total of 212 valid answers were collected. Subsequently, their main harvesting postures were classified into three groups to examine the differences in MSD occurrence and severity among those groups. The results indicate that the harvesting posture did result in different severities of MSDs in certain body areas. Raising hands above the shoulders caused significantly higher MSD severity in the neck, shoulder, upper back, and elbows despite the same standing posture. Additionally, those who squatted, bent, or kneeled had a significantly higher severity of MSDs in the shoulders compared to those who stood but did not raise their hands above their shoulders. This study confirmed that the different harvesting heights of fruits can affect farmers’ posture, leading to differences in the body areas affected by, and severity of, MSDs.
Analytical Investigation of Forced Oxidized Anti-VEGF IgG Molecules: A Focus on the Alterations in Antigen and Receptor Binding Activities
Authors: Parlar Ayhan , Gurel Busra , Sönmez Mehmet Reşit , Yüce Meral
Published: June 2023

Alterations in the biological activity of the molecules under stress conditions have not been documented as widely in the literature yet. This study was designed to reveal the functional impacts of various oxidation conditions on a model mAb, a commercial anti-VEGF IgG molecule. The responses to antigen binding, cell proliferation, FcRn receptors, and C1q binding, which rarely appear in the current literature, were investigated. The authors report peptide mapping data, post-translational modification (PTM) analysis, cell proliferation performance, and antigen (VEGF), C1q, and FcRn binding activities of the mAb under various stress conditions. The oxidation-prone site of the mAb was determined as Met252 in the DTLMISR peptide. The VEGF binding activity and anti-cell proliferation activity of the mAbs did not alter, while C1q and FcRn binding capacity significantly decreased under oxidative stress conditions. The full report is vital for many scientific and industrial processes about mAbs. The authors recommend performing functional analyses in addition to the structural studies while investigating the impacts of stress factors on therapeutic mAbs.
The Experiences of Expectant and New Mothers in Accessing Maternal Healthcare Services during the COVID-19 Pandemic in Mmabatho, North-West, South Africa
Authors: Mohulatsi Makgake Ziphorah , Garutsa Tendayi Clotilda , Bahule Boipelo
Published: June 2023

Access to maternal healthcare has been a challenge for women of African descent. Similarly, to previous illness outbreaks such as the Ebola and Zika outbreaks, the Coronavirus pandemic effects vary from one demographic group to another. Women, compared to men, are left in a more vulnerable position due to long-existing social inequalities and disparities. Differentiated effects include, amongst others, access to health and healthcare, risk of infection and coping strategies. This study examined the experiences of expectant and new mothers in accessing maternal healthcare services during the COVID-19 pandemic. In-depth interviews were used, and participants were selected from Mmabatho, North-West Province in South Africa. The findings show that women accessing maternal healthcare services have had diverse experiences. Some expectant and new mothers experienced fear, anxiety, and frustration, while some had more positive experiences. The positive experiences included spending more time with their families and newborn babies. Some of the participants were worried because of the fear of being infected with the coronavirus. Furthermore, the unavailability and inadequacy of, as well as limited access to, maternal healthcare services during the COVID-19 pandemic negatively affected some of the women in the study. This study recommends that public and private sectors responsible for providing maternal healthcare should have emergency preparedness measures in place to ensure the continuous provision of maternal healthcare and cushion women in future disease pandemics.
Water Requirements and Comprehensive Benefit Evaluation of Diversified Crop Rotations in the Huang-Huai Plain
Authors: Peng Huanhuan , Xiong Jinran , Zhang Jiayi , Zhu Linghui , Wang Guiyan , Pacenka Steven , Yang Xiaolin
Published: June 2023

An intensified farming system can significantly increase crop productivity but can also cause major groundwater overdraft for irrigation and the loss of crop diversity. It is imperative to develop alternative crop rotations beyond the simplified conventional winter wheat–summer maize (W–M) rotation for alleviating the groundwater over-extraction in China’s Huang-Huai Plain. This study systematically quantified crop water requirement (ETc) and irrigation water requirement (ETaw) of eight crops from 2013 to 2018 based on the SIMETAW model applied to the Shangqiu area in the Huang-Huai Plain. Fourteen crop rotations (CI (i.e., crop harvests per rotation cycle year) 1.5 or 2) were constructed based on the ROTAT model. Results showed that compared to W–M rotation, the alternative rotations (CI = 1.5) significantly reduced the annual ETc in wet, normal, and dry years by 9–21%. Replacing winter wheat in the double cropping system did not significantly decrease annual ETc. Wheat–soybean rotation had similar annual ETc and ETaw accompanied by higher economic output and equivalent yield about 1.2 times, with 9% more protein output than the W–M rotation. There were eight crop rotations having greater comprehensive evaluation index (CEI) than W–M rotation by Entropy-TOPSIS when considering 10 indicators including water requirements, yield, economic benefits, water use efficiency, energy, and nutritional values. Spring potato–summer soybean had the highest CEI of 0.627. Sweet potato and potato showed advantages when included in rotations by increasing yield. “Wheat–soybean”-based rotations (CI = 1.5) also performed well in profitability and protein output. Replacing summer maize with soybean is promising for profitability and nutrition output without increasing irrigation requirements. Therefore, decreasing the cropping index, or involving soybean or sweet potato in rotations can be a useful way to improve sustainable land use, save water, and ensure food products in this water stressed region.
Comparison of Ratioing and RCNA Methods in the Detection of Flooded Areas Using Sentinel 2 Imagery (Case Study: Tulun, Russia)
Authors: Fernandez Helena Maria , Granja-Martins Fernando , Dziuba Olga , Pereira David A. B. , Isidoro Jorge M. G. P.
Published: June 2023

Climate change and natural disasters caused by hydrological, meteorological, and climatic phenomena have a significant impact on cities. Russia, a continental country with a vast territory of complex geographic–ecological environments and highly variable climatic conditions, is subject to substantial and frequent natural disasters. On 29 June 2019, an extreme precipitation event occurred in the city of Tulun in the Irkutsk oblast, Russian Federation, which caused flooding due to the increase in the water level of the Iya River that passes through the city, leaving many infrastructures destroyed and thousands of people affected. This study aims to determine the flooded areas in the city of Tulun based on two change detection methods: Radiometric Rotation Controlled by No-change Axis (RCNA) and Ratioing, using Sentinel 2 images obtained before the event (19 June 2019) and during the flood peak (29 June 2019). The results obtained by the two methodologies were compared through cross-classification, and a 98% similarity was found in the classification of the areas. The study was validated based on photointerpretation of Google Earth images. The methodology presented proved to be useful for the automatic precession of flooded areas in a straightforward, but rigorous, manner. This allows stakeholders to efficiently manage areas that are buffeted by flooding episodes.
Research on Database Construction and Calculation of Building Carbon Emissions Based on BIM General Data Framework
Authors: Zhang Ruizhe , Zhang Hong , Hei Shangang , Ye Hongyu
Published: June 2023

China is entering a new era characterized by carbon peaking and carbon neutrality, and the construction industry, which accounts for a high proportion of social carbon emissions, urgently needs a method to calculate and predict building carbon emissions in advance. This study proposes a method for calculating the life cycle carbon emissions (LCCEs) of buildings based on building information modeling (BIM) technology. The method uses a BIM universal data framework to establish a building carbon emission calculation model and a building carbon emission factor database instance. Taking prefabricated construction projects as an example, it is compared with the traditional calculation method. The results show that the method can more accurately predict building carbon emissions and provide methods and a basis for the construction industry to control carbon emissions in advance.
Construction of Community Grid Unit Assessment System from the Perspective of Refined Governance
Authors: Li Ningzhi , Su Lilan
Published: June 2023

On the basis of reviewing the typical models of urban community grid governance, the framework of the community grid unit assessment system was put forward according to the main tasks of current grid management. The five grid governance tasks such as convenient service, risk reporting, contradiction persuasion, grid patrol, and problem investigation were taken as the first-level indicators, a theoretical model of a three-level grid unit assessment was established, and the community grid unit assessment system was constructed. Combined with big data platforms such as public security, civil administration, and the politics and law committee, this paper aims to solve the problems of performance assessment of community grid members, the distribution of grid members, the needs of the people, and the service of enterprises and volunteers, and promote the common development of communities, grid members, enterprises, and volunteers, and realize the refinement of grid governance.
Dibutyl Phthalate Adsorbed on Multiwalled Carbon Nanotubes Causes Fetal Developmental Toxicity in Balb/C Mice
Authors: Qin Yujie , He Suli , Peng Haiyan , Ye Xin , Zhang Hongmao , Ding Shumao
Published: June 2023

This study investigated whether using multiwalled carbon nanotubes (MWCNTs) as a carrier for dibutyl phthalate (DBP) could delay the degradation rate of DBP in mice and increase its estrogen-like interference effect. Pregnant Balb/C mice were divided into four groups and exposed to different treatments via tail-vein injection every 3 days until gestational day 20. The female and male mice were then sacrificed for toxicological study. The results showed that the combination of MWCNTs and DBP resulted in a higher fetal mortality rate than if the mice were exposed to MWCNTs or DBP alone. H&E staining showed that the estrous period of the exposed mice was delayed, the development of oocytes was blocked in the combination group, the number of spermatogenic cells decreased, and the quality of sperm decreased. Our experiment showed that the expression levels of the genes involved in sex hormone synthesis in the testis and ovaries were significantly increased after combined treatment compared with the MWCNT group (p < 0.01). The study suggests that DBP degradation is delayed when absorbed on MWCNTs, which increases its estrogen-like interference and interferes with fetal development, ultimately leading to increased fetal mortality.
Effect of Arsenic Soil Contamination on Stress Response Metabolites, 5-Methylcytosine Level and CDC25 Expression in Spinach
Authors: Popov Marek , Kubeš Jan , Vachová Pavla , Hnilička František , Zemanová Veronika , Česká Jana , Praus Lukáš , Lhotská Marie , Kudrna Jiří , Tunklová Barbora , Štengl Karel , Krucký Jiří , Turnovec Tomáš
Published: June 2023

Experimental spinach plants grown in soil with (5, 10 and 20 ppm) arsenic (As) contamination were sampled in 21 days after As(V) contamination. Levels of As in spinach samples (from 0.31 ± 0.06 µg g−1 to 302.69 ± 11.83 µg g−1) were higher in roots and lower in leaves, which indicates a low ability of spinach to translocate As into leaves. Species of arsenic, As(III) and As(V), were represented in favor of the As (III) specie in contaminated variants, suggesting enzymatic arsenate reduction. In relation to predominant As accumulation in roots, changes in malondialdehyde levels were observed mainly in roots, where they decreased significantly with growing As contamination (from 11.97 ± 0.54 µg g−1 in control to 2.35 ± 0.43 µg g−1 in 20 ppm As). Higher values in roots than in leaves were observed in the case of 5-methylcytosine (5-mC). Despite that, a change in 5-mC by As contamination was further deepened in leaves (from 0.20 to 14.10%). In roots of spinach, expression of the CDC25 gene increased by the highest As contamination compared to the control. In the case of total phenolic content, total flavonoid content, total phenolic acids content and total antioxidant capacity were higher levels in leaves in all values, unlike the roots.