bluuebunny/crossref_metadata_2025 huggingface dataset:
Pollution Levels and Potential Health Risks of Potentially Toxic Elements in Indoor and Outdoor Dust during the COVID-19 Era in Gómez Palacios City, Mexico
Authors: Santoyo-Martínez Miguel , Aguilera Anahí , Gallegos Ángeles , Puente Cristo , Goguitchaichvili Avto , Bautista Francisco
Published: December 2022

The COVID-19 pandemic has caused a decrease in outdoor activities, but an increase in indoor ones. This change in the intensity of land use has caused changes in pollution patterns. Urban dust contaminated with heavy metals can be a risk to the human population. Therefore, the objective of this work was to evaluate the pollution caused by heavy metals in urban dust indoors and outdoors due to changes in land use during the pandemic. Sampling was carried out by the Gomez Palacio citizens. The total number of urban dust samples was 330, 50% indoor samples and 50% outdoor sample. The elements studied were Ca, Cu, Fe, K, Mn, Ni, Pb, Rb, Sr, Ti, Y, Zn, and Zr. The heavy metals were measured through a portable XRF; the contamination factor and the load pollution index were used to assess the pollution level. The human health risk was evaluated with the USEPA methodology. Cu, Pb, and Zn presented higher concentrations indoors than outdoors, probably due to domestic factors, such as the age of the houses and the paint on the walls. Zn presented the highest pollution level among all the metals, outdoors and indoors; spatially, the sites sampled in the northwest, close to agricultural areas, presented the highest Zn pollution. Pb had a moderate pollution level in most of the samples (60%), but some samples showed a high Pb pollution. The health risk was considered within the acceptable levels for Cu, Fe, Ni, Pb, Zn. However, Mn deserves attention because the average of the samples slightly exceeded the USEPA safety limits for children. Children are at higher risk compared to adults. Indoor environments need to be better analyzed because they were shown to represent a higher risk to the population than outdoor ones due to heavy metal pollution by Zn, Cu, and Pb. The pandemic impacted land use intensity; this study reports an apparent effect of the pandemic on the amount and type of heavy metals indoors and outdoors.
Postproduction in the Research on the Urban Cultural Landscape: From the Transfer of Results to the Exchange of Knowledge on Digital Platforms and Social Networks—The TRAHERE Project in Madrid
Authors: Trovato Graziella
Published: December 2022

The urban scenarios outlined by the environmental and economic crisis have fostered, on one hand, the unstoppable gentrification of the most central neighborhoods of the cities; and on the other hand, a growing associationism committed to cultural and environmental values, which demands tools from academia to negotiate with the administration. An emblematic case is that of Arganzuela, one of the three districts of the Spanish capital affected by the rise and fall of industrialization (the freight railway in 1861 and the M-30 ring road in 1970). The burying of these infrastructures began in 1990 with the Green Railway Corridor (PVF) operation, a year after the inauguration in Paris of the Promenade Plantée on the disused railway lands, which allows us to foreshadow new scenarios. The TRAHERE project researches the state of abandonment and disaffection of the public spaces of the PVF using social networks as a connection platform with participatory channels to promote its regeneration. The challenge is to convert the concept of transfer of results into a more inclusive one of knowledge exchange, which implies a methodological change in research, with an integrating perspective that combines urban historical studies with artistic practices of production and postproduction for the dissemination of content on the networks.
Machine Learning Models for Prediction of Soil Properties in the Riparian Forests
Authors: Zolfaghari Nia Masoud , Moradi Mostafa , Moradi Gholamhosein , Taghizadeh-Mehrjardi Ruhollah
Published: December 2022

Spatial variability of soil properties is a critical factor for the planning, management, and exploitation of soil resources. Thus, the use of different digital soil mapping models to provide accuracy plays a crucial role in providing soil physicochemical properties maps. Soil spatial variability in forest stands is not well-known in Iran. Meanwhile, riparian buffers are important for several services such as providing high water quality, nutrient recycling, and buffering agricultural production. Accordingly, in this research, 103 soil samples were taken using the Latin hypercubic method in the Maroon riparian forest of Behbahan and agricultural lands in the vicinity of the forest to evaluate the spatial variability of soil nitrogen, potassium, organic carbon, C:N ratio, pH, calcium carbonate, sand, silt, clay, and bulk density. Different machine learning models, including artificial neural networks, random forest, cubist regression tree, and k-nearest neighbor were used to compare the estimation of soil properties. Moreover, three main sources of spatial information including remote sensing images, digital elevation model, and climate parameters were used as ancillary data. Our results indicated that the random forest model has the best results in estimating soil pH, nitrogen, potassium, and bulk density. In contrast, the cubist regression tree indicated the best estimation for organic carbon, C:N ratio, phosphorous, and clay. Further, artificial neural networks showed the best estimation for calcium carbonate, sand, and silt contents. Our results revealed that geospatial information such as terrain parameters, climate parameters, and satellite images could be well used as ancillary data for the spatial mapping of soil physiochemical properties in riparian forests and agricultural lands. In conclusion, a specific machine learning model needs to be used for each soil property to provide highly accurate maps with less error.
Applicability Analysis of GF-2PMS and PLANETSCOPE Data for Ground Object Recognition in Karst Region
Authors: Zhang Yu , Shen Chaoyong , Zhou Shaoqi , Yang Ruidong , Luo Xuling , Zhu Guanglai
Published: December 2022

Remote sensing image with high spatial and temporal resolution is very important for rational planning and scientific management of land resources. However, due to the influence of satellite resolution, revisit period, and cloud pollution, it is difficult to obtain high spatial and temporal resolution images. In order to effectively solve the “space–time contradiction” problem in remote sensing application, based on GF-2PMS (GF-2) and PlanetSope (PS) data, this paper compares and analyzes the applicability of FSDAF (flexible spatiotemporal data fusion), STDFA (the spatial temporal data fusion approach), and Fit_FC (regression model fitting, spatial filtering, and residual compensation) in different terrain conditions in karst area. The results show the following. (1) For the boundary area of water and land, the FSDAF model has the best fusion effect in land boundary recognition, and provides rich ground object information. The Fit_FC model is less effective, and the image is blurry. (2) For areas such as mountains, with large changes in vegetation coverage, the spatial resolution of the images fused by the three models is significantly improved. Among them, the STDFA model has the clearest and richest spatial structure information. The fused image of the Fit_FC model has the highest similarity with the verification image, which can better restore the coverage changes of crops and other vegetation, but the actual spatial resolution of the fused image is relatively poor, the image quality is fuzzy, and the land boundary area cannot be clearly identified. (3) For areas with dense buildings, such as cities, the fusion image of the FSDAF and STDFA models is clearer and the Fit_FC model can better reflect the changes in land use. In summary, compared with the Fit_FC model, the FSDAF model and the STDFA model have higher image prediction accuracy, especially in the recognition of building contours and other surface features, but they are not suitable for the dynamic monitoring of vegetation such as crops. At the same time, the image resolution of the Fit_FC model after fusion is slightly lower than that of the other two models. In particular, in the water–land boundary area, the fusion accuracy is poor, but the model of Fit_FC has unique advantages in vegetation dynamic monitoring. In this paper, three spatiotemporal fusion models are used to fuse GF-2 and PS images, which improves the recognition accuracy of surface objects and provides a new idea for fine classification of land use in karst areas.
When Service-Led Activities and Tertiarization Processes Replace Old Industries and Local Brownfields: Changes, Perceptions and Perspectives in the Northern Industrial Area of Lugoj, Romania
Authors: JUCU Ioan Sebastian
Published: December 2022

This paper examines the transformation of the brownfield sites and the places occupied by old industrial activities in Romania, focusing on a medium-sized town since small- and medium-sized towns are mainly overlooked in the current scientific debates. These towns frequently followed similar development patterns to large cities, but at different paces in local urban regeneration. We conducted a case study on the Romanian town Lugoj, focusing on one of the most important industrial areas which encountered a significant decline during the post-socialist period where ruins remain as proof of the post-socialist urban regeneration efforts. Recent years (2020–2022) unveiled a great interest in the regeneration of this area with positive spatial outcomes, experiencing a massive development of tertiary activities and thus turning this former industrial area into a service-led one, with some industrial units that were completely regenerated while others remain in ruins. The research was conducted from 2020 to 2022 and used qualitative methods and spatial analysis through GIS methods. The results emphasize the recent changes in the former industrial areas, where service activities replaced the previous old industries. Furthermore, the main findings highlight that the investigated area provides multiple opportunities for further development, thus contributing to the regeneration of the area through the development of a wide variety of tertiary activities. Since small- and medium-sized municipalities remain overlooked in the recent research, this study could represent a significant example for further strategies of the urban development of small towns that have been strongly altered by the local inherited industrial brownfields.
Long-Term Visioning for Landscape-Based Spatial Planning—Experiences from Two Regional Cases in The Netherlands
Authors: Voskamp Ilse , Timmermans Wim , Roosenschoon Onno , Kranendonk Remco , van Rooij Sabine , van Hattum Tim , Sterk Marjolein , Pedroli Bas
Published: December 2022

Normative scenarios for long-term (e.g., 100 years) landscape development can be very inspiring to imagine outside the box landscape futures, without being obliged to define concrete policy objectives for the shorter term. However, it remains challenging to translate such long-term visions into clear transition pathways. We draw upon a landscape-based design approach to local spatial planning to foster a transition to a well-functioning landscape, resilient to various external pressures. Inspired by a national visioning exercise for the Netherlands in 2120, two local case studies at municipal level in the Netherlands are analysed, aiming to identify in what ways the setup of a regional landscape-based design study using future visions can optimise the spatial planning process. Therefore, this comparative case study analysed the cases on the landscape-based approach, the design process, and the future visions formulated. The comparison shows that fostering abiotic differences safeguards sustainable and resilient landscapes; moreover, co-creation relying on representative local actors appears fundamental for shared solutions, while a landscape-based approach guarantees transitions to adaptive and biodiverse landscapes. We conclude that a shared long-term future landscape vision is a crucial source of inspiration to solve today’s spatial planning problems. The constellation of the stakeholder group involved and the methodological setup of a visioning process are determinative for the way a long-term vision is suited to informing spatial planning for a sustainable future.
The Role of Ultrasound in Accessing the Distal Radial Artery at the Anatomical Snuffbox for Cardiovascular Interventions
Authors: Achim Alexandru , Péter Orsolya Ágnes , Kákonyi Kornél , Sasi Viktor , Nemes Attila , Homorodean Călin , Stanek Agata , Olinic Dan Mircea , Ruzsa Zoltán
Published: December 2022

In an effort to refine transcatheter vascular interventions, radial artery access has moved more distally at the anatomical snuffbox. Here, more challenges appear as the artery is smaller, more angulated, and more difficult to palpate. Including ultrasound guidance as a mandatory step during puncture may encourage more operators to switch to this approach. In the femoral approach, ultrasound guidance is strongly recommended because of bleeding complications, whereas in the proximal (conventional) radial approach, the role of ultrasound remains optional, and in current practice, almost all cases are performed by palpation of the pulse only. However, in distal radial access, the situation is different because the artery differs in caliber and position, and imaging can help the operator for a clean puncture, especially since repeated punctures are not only painful but also any hematoma formation leads to the complete compression of the artery and failure of access. The aim of this review is to investigate the rationale of vascular ultrasound during distal radial access and to establish some techniques and anatomical landmarks for the ultrasonographic exploration of the dorsal area of the hand.
Active Vibration Control of Composite Cantilever Beams
Authors: Huang Zhicheng , Huang Fan , Wang Xingguo , Chu Fulei
Published: December 2022

This paper deals with the active vibration control of composite cantilever beam. Based on the finite element method and Golla–Hughes–McTavish (GHM) model, the system dynamics equation is established. Models are simplified in physical and modal space because of unobservable and uncontrollable. Based on the particle swarm optimization (PSO) algorithm, the linear quadratic regulator (LQR) feedback gain was optimized. The effect of system vibration damping under different controller parameters, piezoelectric-constrained layer position and excitation signal was studied. The study show that the optimal feedback gain of the controller can effectively balance the control effect and the control cost. The closer the piezoelectric layer and viscoelastic layer are to the fixed end, the better the system control effect and the smaller the control cost. The reduced-order model has a good control effect on different excitation signals.
Synthesis, Structural and Magnetic Properties of Cobalt-Doped GaN Nanowires on Si by Atmospheric Pressure Chemical Vapor Deposition
Authors: Feng Zhe Chuan , Liu Yu-Lun , Yiin Jeffrey , Chen Li-Chyong , Chen Kuei-Hsien , Klein Benjamin , Ferguson Ian T.
Published: December 2022

GaN nanowires (NWs) grown on silicon via atmospheric pressure chemical vapor deposition were doped with Cobalt (Co) by ion implantation, with a high dose concentration of 4 × 1016 cm−2, corresponding to an average atomic percentage of ~3.85%, and annealed after the implantation. Co-doped GaN showed optimum structural properties when annealed at 700 °C for 6 min in NH3 ambience. From scanning electron microscopy, X-ray diffraction, high resolution transmission electron microscope, and energy dispersive X-ray spectroscopy measurements and analyses, the single crystalline nature of Co-GaN NWs was identified. Slight expansion in the lattice constant of Co-GaN NWs due to the implantation-induced stress effect was observed, which was recovered by thermal annealing. Co-GaN NWs exhibited ferromagnetism as per the superconducting quantum interference device (SQUID) measurement. Hysteretic curves with Hc (coercivity) of 502.5 Oe at 5 K and 201.3 Oe at 300 K were obtained. Applied with a magnetic field of 100 Oe, the transition point between paramagnetic property and ferromagnetic property was determined at 332 K. Interesting structural and conducive magnetic properties show the potential of Co-doped GaN nanowires for the next optoelectronic, electronic, spintronic, sensing, optical, and related applications.
Experimental Data Collection of Surface Quality Analysis of CuCrZr Specimens Manufactured with SLM Technology: Analysis of the Effects of Process Parameters
Authors: Caravella Ilaria , Cortis Daniele , Di Angelo Luca , Orlandi Donato
Published: December 2022

Selective laser melting (SLM) is the most widely used laser powder-bed fusion (L-PBF) technology for the additive manufacturing (AM) of parts from metallic powders. The surface quality of the SLM parts is highly dependent on many factors and process parameters. These factors include the powder grain size, the layer thickness, and the building angle. This paper conducted an experimental analysis of the effects of SLM process parameters on the surface quality of CuCrZr cubic specimens. Thanks to its excellent thermal and mechanical properties, CrCrZr has become one of the most widely used materials in SLM technology. The specimens have been produced with different combinations of layer thickness, laser patterns, building angles, and scanning speed, keeping the energy density constant. The results show how different combinations of parameters affect the surface quality macroscopically (i.e., layer thickness, building angle, and scanning speed); in contrast, other parameters (i.e., laser pattern) do not seem to have any contributions. By varying these parameters within typical ranges of the AM machine used, variations in surface quality can be achieved from 10.4 µm up to 40.8 µm. These results represent an important basis for developing research activities that will further focus on implementing a mathematical/experimental model to help designers optimize the surface quality during the AM pre-processing phase.
Enhanced High−Temperature Wear Performance of H13 Steel through TiC Incorporation by Laser Metal Deposition
Authors: Lu Chengqi , Chen Zhenyu , Yan Yuqing , Zhuo Yuhao , Wang Chuanyang , Jia Qingbo
Published: December 2022

High−temperature wear failure has been a major challenge to die parts. This work provides a comprehensive study on the high−temperature wear performance of a TiC/H13 composite coating prepared by laser metal deposition (LMD). The microstructures of wrought H13 samples, LMD−processed H13 and TiC/H13 samples were systematically investigated. The refined martensite size, the uniform distribution of TiC ceramic particles, as well as their bonding with the matrix endowed the fabricated composite coating with superior hardness. The LMD−prepared TiC/H13 composite coating material demonstrated outstanding wear resistance when compared with other counterparts, mainly due to the high thermal stability and the load-transferring effect triggered by the introduced TiC ceramic particles. The dominated wear mechanism transition from severe ploughing in the wrought H13 material to mild delamination in the TiC/H13 composite coating was confirmed. The present study is expected to shed light on high-temperature wear-resistant coating material design and applications within the highly demanding mould industry.
A Wideband High-Isolation Microstrip MIMO Circularly-Polarized Antenna Based on Parasitic Elements
Authors: Khan Ijaz , Zhang Kuang , Wu Qun , Ullah Inam , Ali Luqman , Ullah Habib , Rahman Saeed Ur
Published: December 2022

This work presents a wideband, all-side square-cut square patch multiple-input, multiple-output circularly-polarized (MIMO-CP) high-isolation antenna. The MIMO-CP antenna contains a two-port square cut on all corners of the square patch, and parasitic elements of 9 × 5 periodic square metallic plates are designed and operated. The outer dimensions of the antenna are 40 × 70 mm2, and the FR4 substrate height is 1.6 mm. The proposed antenna with the parasitic elements improves impedance matching and enhances S-parameters and axial ratio (AR). In the suggested MIMO-CP antenna, a parasitic element is designed and placed around the antenna periodically to reduce mutual coupling (MC) and improve CP. Simulated results show that the suggested antenna has a wide bandwidth (BW) from 4.89 to 6.85 GHz for S11 and was < −10 dB with AR ≤ 3 dB from 5.42 to 6.58 GHz, with a peak gain of 6.6 dB. The suggested antennas have more than 30 dB isolation and a low profile, are affordable, easily made, and are CP. To make a comparison with the measured and simulated results, a MIMO-CP antenna structure was fabricated and tested. The suggested antenna is better in terms of efficiency, envelope correlation coefficient (ECC), diversity gain (DG), channel capacity loss (CCL), and total active reflection coefficient (TARC). The proposed antenna is adequate for WLAN applications.
Effects of Excimer Laser Treatment of Zirconia Disks on the Adhesion of L929 Fibroblasts
Authors: Akashi Yoshihiko , Shimoo Yoshiaki , Hashiguchi Hayato , Nakajima Kei , Kokubun Katsutoshi , Matsuzaka Kenichi
Published: December 2022

The adhesion of zirconia and soft tissue is very important for the success of zirconia implants. The aim of this study was to characterize the effects of excimer laser treatment of zirconia on the adhesion of L929 fibroblasts. In this study, polished zirconia disks treated with an excimer laser were the experimental group and untreated zirconia disks were the control group. Surface roughness and contact angles of zirconia disks were measured. mRNA expression levels of integrin β1 and collagen type I α1 in L929 fibroblasts cultured on zirconia disks were measured using qRT-PCR. Cell morphology was evaluated using 3D laser microscopy and the expression of vinculin was characterized using confocal microscopy. There was no significant difference in the surface roughness of zirconia disks, but contact angles were significantly lower. mRNA expression of integrin β1 was significantly higher at 3, 6 and 24 h and of collagen type I α1 was significantly higher at 6 and 24 h. L929 fibroblasts tended to form elongated microspikes and vinculin colocalization in those microspikes. Furthermore, vinculin was strongly expressed in filopodia of L929 fibroblasts at 24 h. These results suggest that excimer laser treatment improves adhesion between zirconia disks and L929 fibroblasts.
Cryogenic Reliability Evaluation of Glass Fabric–Reinforced Composites Using Novel Slip-Prevention Method
Authors: Jeong Yong-Cheol , Lee Dong-Ha , Kim Seul-Kee , Kim Jeong-Hyeon , Lee Jae-Myung
Published: December 2022

Glass fabric–reinforced composites are the main insulating material components of the secondary barrier of cargo containment systems (CCSs), because they prevent liquefied natural gas (LNG) leakage during transport. Nevertheless, it is difficult to evaluate the material performance of glass fabric–reinforced composites at cryogenic temperatures (−163 °C) because it takes approximately 7 days to prepare the test specimens and because the slip-based test frequently fails. Although glass fabric–reinforced composites for the secondary barrier of LNG CCSs show various structural vulnerabilities, enhancing their material performance is significantly limited owing to the reasons mentioned above. This study evaluated the structural vulnerabilities and failure characteristics of glass fabric–reinforced composites by using the slip-prevention test method to determine the level difference and adhesive vacancies. The failure surface and the thermal expansion of the composites were also observed, to analyze their mechanical characteristics. By adopting our proposed test procedure, the failure rate of the experiment decreased by approximately 80%, and the sample preparation time for manufacturing was significantly shortened, to 1 day.
Study on the Tensile Behavior of Helical Auxetic Yarns with Finite Element Method
Authors: Liu Sai , Du Zhaoqun
Published: December 2022

Complex yarns with helical wrapping structure show auxetic effect under axial tension and a wide perspective application. Experimental results suggested that initial helical angle was one of the most important structural parameters. However, the experimental method was limited and could not effectively explain the deformation behavior or auxetic mechanism. A finite element model of the helical auxetic yarn was built and used to analyze the interactive relationship between the two components and the stress distribution mode. The effectiveness and accuracy of the model was first verified by comparing with the experimental results. The simulation results showed that the complex yarn with initial helical angle of 14.5° presented the maximum negative Poisson’s ratio of −2.5 under 5.0% axial strain. Both the contact property between the two components and the radial deformability of the elastic core filament were key factors of the auxetic property. When the contact surfaces were completely smooth and the friction coefficient μ was set to 0, the complex yarn presented non-auxetic behavior. When the Poisson’s ratio of the core filament was 0, the complex yarn showed greater auxetic effect. During the axial stretching, the tensile stress was mainly distributed in the wrap filament, which led to structural deformation and auxetic behavior. A pair of auxetic yarns showed pore effect and high expansion under axial strain. Thus, it may be necessary to consider new weaving structures and preparation methods to obtain the desired auxetic property and application of auxetic yarns.
Simulation Analysis and Experimental Study of the Strength of Aluminum Alloy Suspension Structure
Authors: Qian Wenxue , Wu Ningxiang , Li Hao , Yin Xiaowei , Xie Liyang
Published: December 2022

High-speed trains have a large amount of ancillary equipment, which is suspended from the underside of the train by means of a suspension structure. Due to the large mass of the ancillary equipment, the suspension structure is subjected to various loads during train operation and there is a risk of fatigue failure. In this paper, the stress distribution at the suspension point and the lo-cation of the maximum stress point under load are investigated in detail based on actual test loads at the suspension point and finite element simulation analysis. In order to further investigate the fracture failure of the suspension points, experimental studies were carried out. Firstly, static strength tests were carried out to obtain the load–displacement curves of the structural members and to determine the fracture strength of the structure based on the displacement sensors, and secondly, fatigue tests at different stress levels were carried out to obtain the load–life curves of the structural members and to investigate the probabilistic load–life curves at different reliability levels. The test results show that the structural component has a high fracture strength of 65kN, while the conditional fatigue strength is relatively low, corresponding to a load level of 12.5kN at a median life of 106 cycles. The above research work provides the necessary basis for the design, optimization and reliability assessment of the suspension structures of high-speed trains.
Damping and Mechanical Properties of Epoxy/316L Metallic Lattice Composites
Authors: Wei Yanpeng , Li Huaiqian , Yang Hao , Ma Yingchun , Cheng Jingchang , Gao Peng , Shi Jian , Yu Bo , Lin Feng
Published: December 2022

The lattice structure was prepared by selective laser melting of 316L metal powder, and the epoxy was naturally infiltrated into the pores of the 316L metallic lattice structure. The epoxy/316L metallic lattice composites with integrated structure and function were prepared. Scanning electron microscopy was used to observe the microstructure of the epoxy/316L metallic lattice composites. The damping performance of the epoxy/316L metallic lattice composites were studied by modal measurement method. At the same time, the engineering stress–strain curve was obtained by a quasi-static compression experiment on a universal testing machine. The results show that the interface of epoxy and 316L metallic lattice is well bonded, and there are a few bubbles in the epoxy. The epoxy/316L metallic lattice composites have high damping characteristics with damping ratio over 10%. The energy absorption of epoxy/316L metallic lattice composites is as high as 68.32 MJ/m3, showing high energy absorption characteristics.
How to Create Trusted Tribological Characterization Data of Soft Polymers as Input for FEM Simulations?
Authors: Herr Marin , Borras F. Xavier , Spaltmann Dirk , Kröll Mirco , Pirker Franz , Cihak-Bayr Ulrike
Published: December 2022

Soft polymers such as the investigated polyurethane, characterized by low Young’s moduli and prone to high shear deflection, are frequently applied in pneumatic cylinders. Their performance and lifetime without external lubrication are highly determined by the friction between seal and shaft and the wear rate. FEM simulation has established itself as a tool in seal design processes but requires input values for friction and wear depending on material, load, and velocity. This paper presents a tribological test configuration for long stroke, reciprocating movement, allowing the generation of data which meet the requirements of input parameters for FEM simulations without the geometrical influences of specific seal profiles. A numerical parameter study, performed with an FEM model, revealed the most eligible sample geometry as a flat, disc-shaped sample of the polymer glued on a stiff sample holder. At the same time, the study illustrates that the sensitivity of the contact pressure distribution to Poisson’s ratio and CoF can be minimized by the developed and verified setup. It ensures robust, reliable, and repeatable experimental results with uniform contact pressures and constant contact areas to be used in databases and FEM simulations of seals, enabling upscaling from generically shaped samples to complex seal profiles.
Digital Twins Utilizing XR-Technology as Robotic Training Tools
Authors: Kaarlela Tero , Padrao Paulo , Pitkäaho Tomi , Pieskä Sakari , Bobadilla Leonardo
Published: December 2022

Digital technology has evolved towards a new way of processing information: web searches, social platforms, internet forums, and video games have substituted reading books and writing essays. Trainers and educators currently face the challenge of providing natural training and learning environments for digital-natives. In addition to physical spaces, effective training and education require virtual spaces. Digital twins enable trainees to interact with real hardware in virtual training environments. Interactive real-world elements are essential in the training of robot operators. A natural environment for the trainee supports an interesting learning experience while including enough professional substances. We present examples of how virtual environments utilizing digital twins and extended reality can be applied to enable natural and effective robotic training scenarios. Scenarios are validated using cross-platform client devices for extended reality implementations and safety training applications.
Advanced Motor Control for Improving the Trajectory Tracking Accuracy of a Low-Cost Mobile Robot
Authors: Mérida-Calvo Luis , Rodríguez Andrés San-Millán , Ramos Francisco , Feliu-Batlle Vicente
Published: December 2022

Accurate trajectory tracking is a paramount objective when a mobile robot must perform complicated tasks. In high-speed movements, time delays appear when reaching the desired position and orientation, as well as overshoots in the changes of orientation, which prevent the execution of some tasks. One of the aspects that most influences the tracking performance is the control system of the actuators of the robot wheels. It usually implements PID controllers that, in the case of low-cost robots, do not yield a good tracking performance owing to friction nonlinearity, hardware time delay and saturation. We propose to overcome these problems by designing an advanced process control system composed of a PID controller plus a prefilter combined with a Smith predictor, an anti-windup scheme and a Coulomb friction compensator. The contribution of this article is the motor control scheme and the method to tune the parameters of the controllers. It has been implemented in a well-known low-cost small mobile robot and experiments have been carried out that demonstrate the improvement achieved in the performance by using this control system.
Two-Stage Optimal Active-Reactive Power Coordination for Microgrids with High Renewable Sources Penetration and Electrical Vehicles Based on Improved Sine−Cosine Algorithm
Authors: Sidea Dorian O. , Tudose Andrei M. , Picioroaga Irina I. , Bulac Constantin
Published: December 2022

As current global trends aim at the large-scale insertion of electric vehicles as a replacement for conventional vehicles, new challenges occur in terms of the stable operation of electric distribution networks. Microgrids have become reliable solutions for integrating renewable energy sources, such as solar and wind, and are considered a suitable alternative for accommodating the growing fleet of electrical vehicles. However, efficient management of all equipment within a microgrid requires complex solving algorithms. In this article, a novel two-stage scheme is proposed for the optimal coordination of both active and reactive power flows in a microgrid, considering the high penetration of renewable energy sources, energy storage systems, and electric mobility. An improved sine-cosine algorithm is introduced to ensure the day-ahead optimal planning of the microgrid’s components aiming at minimizing the total active energy losses of the system. In this regard, both local and centralized control strategies are investigated for multiple generations and consumption scenarios. The latter proved itself a promising control scheme for the microgrid operation, as important energy loss reduction is encountered when applied.
Novel Sesquiterpene and Diterpene Aminoglycosides from the Deep-Sea-Sediment Fungus Trichoderma sp. SCSIOW21
Authors: Li Hongxu , Liu Xinyi , Hu Zhangli , Wang Liyan
Published: December 2022

Six new sesquiterpene aminoglycosides, trichaspside F (2) and cyclonerosides A–E (5–9), two new diterpene aminoglycosides, harzianosides A and B (10, 11), and three known sesquiterpenes, trichodermoside (1), cycloneran-3,7,10,11-tetraol (3), and cyclonerodiol (4), have been isolated from the n-butanol extract of Trichoderma sp. SCSIOW21 (Hypocreaceae), a deep-sea-sediment-derived fungus. The structures and relative configurations of the new compounds were determined using spectroscopic techniques and comparisons with those reported in the literature. The absolute configurations of the aglycone part of cyclonerosides A–E (5–9) were tentatively proposed based on optical rotation and biogenic considerations. Cyclonerosides A–E (5–9) represent the first glycosides of cyclonelane-type sesquiterpenes generated from Trichoderma. The NO-production-inhibitory activities were evaluated using macrophage RAW264.7 cells. Among the isolated compounds, trichaspside F (2) and cyclonerosides B–E (6–9) exhibited the strongest NO-production-inhibitory activities with IC50 values of 54.8, 50.7, 57.1, 42.0, and 48.0 µM, respectively, compared to the IC50 value of 30.8 µM for the positive control (quercetin). When tested for anti-fungal activities against several pathogenic fungi, none of the compounds exhibited significant activities at a concentration of 100 µM.
Application of Alloys in Transport
Authors: Prentkovskis Olegas , Maruschak Pavlo , Panin Sergey , Berto Filippo
Published: December 2022

Improving the reliability of transport vehicles requires ensuring their durability while reducing metal consumption [...]
The Influence of Coating and Adhesive Layers on the Mechanical Performance of Additively Manufactured Aluminum–Polymer Hybrid Joints
Authors: Falck Rielson , Amancio-Filho Sergio T.
Published: December 2022

AddJoining technique has been recently introduced to produce metal–polymer composite hybrid layered structures. The methodology combines the principles of joining and polymeric additive manufacturing. This paper presents three AddJoining process-variants investigated and demonstrated for the material combination aluminum 2024-T3 and acrylonitrile butadiene styrene to form hybrid single lap joints. The microstructure and mechanical performance were assessed. The process variant using heating control showed the ultimate lap shear force of 1.2 ± 0.05 kN and displacement at a break of 1.21 ± 0.16 mm as a result of strong bonding formation at the interface of the hybrid joints. For instance, the other two process variants tested (with epoxy adhesive, and with thin-acrylonitrile butadiene styrene (ABS) coating layer applied on the metal) presented reduced mechanical performance in comparison to process variant using heating control, namely approximately 42% and 8.3%, respectively. The former had a mixed adhesive–cohesive failure due to the lower bonding performance between the adhesive and ABS printed layers. The latter displayed a slight decrease in force in comparison to heat-control specimens. This could be explained by the presence of micro-voids formed by solvent evaporation at the ABS coating layer during AddJoining.
Development of Tiny Vane-Type Magnetorheological Brake Considering Quality Function Deployment
Authors: Lutanto Agus , Ubaidillah U , Imaduddin Fitrian , Choi Seung-Bok , Lenggana Bhre Wangsa
Published: December 2022

Many studies focus on the torque-to-dimension ratio when designing magnetorheological brakes (MRB), especially for ankle foot orthosis (AFO) devices. Vane MRB is one type of MRB with a limited angle of motion that is naturally suitable to be applied to AFO. However, very few implement quality function deployment (QFD) when making MRB, whereas QFD is an essential factor in making product designs. In this study, a tiny vane-type MR brake (TVMRB) was successfully made using the QFD method. Torque characteristics are determined by analysis of magnetic flux density, theoretically, by 3D simulation, and by using Ansys Maxwell experimentally. For consideration, the analysis was carried out with fluid gap variations (0.5 mm, 0.75 mm, and 1 mm) and current variations (0.5–2 A with 0.5 A increments). As a result, ignoring the leakage of MR fluid (MRF), at a constant rotation of 10 rpm, the smallest torque of 6.14 Nm was obtained at the fluid gap variation of 1 mm and input current of 0.5 A, whereas the largest torque was 46.71 Nm at the fluid gap variation of 0.5 mm and input current of 2 A. Apart from torque, this article will also discuss other brake performances in the form of operational range and power consumption. Finally, the structure of the TVMRB design is compared with other designs presented in the House of Quality (HOQ).
Studying Plant–Insect Interactions through the Analyses of the Diversity, Composition, and Functional Inference of Their Bacteriomes
Authors: Mayoral-Peña Zyanya , Lázaro-Vidal Víctor , Fornoni Juan , Álvarez-Martínez Roberto , Garrido Etzel
Published: December 2022

As with many other trophic interactions, the interchange of microorganisms between plants and their herbivorous insects is unavoidable. To test the hypothesis that the composition and diversity of the insect bacteriome are driven by the bacteriome of the plant, the bacteriomes of both the plant Datura inoxia and its specialist insect Lema daturaphila were characterised using 16S sRNA gene amplicon sequencing. Specifically, the bacteriomes associated with seeds, leaves, eggs, guts, and frass were described and compared. Then, the functions of the most abundant bacterial lineages found in the samples were inferred. Finally, the patterns of co-abundance among both bacteriomes were determined following a multilayer network approach. In accordance with our hypothesis, most genera were shared between plants and insects, but their abundances differed significantly within the samples collected. In the insect tissues, the most abundant genera were Pseudomonas (24.64%) in the eggs, Serratia (88.46%) in the gut, and Pseudomonas (36.27%) in the frass. In contrast, the most abundant ones in the plant were Serratia (40%) in seeds, Serratia (67%) in foliar endophytes, and Hymenobacter (12.85%) in foliar epiphytes. Indeed, PERMANOVA analysis showed that the composition of the bacteriomes was clustered by sample type (F = 9.36, p < 0.001). Functional inferences relevant to the interaction showed that in the plant samples, the category of Biosynthesis of secondary metabolites was significantly abundant (1.4%). In turn, the category of Xenobiotics degradation and metabolism was significantly present (2.5%) in the insect samples. Finally, the phyla Proteobacteria and Actinobacteriota showed a pattern of co-abundance in the insect but not in the plant, suggesting that the co-abundance and not the presence–absence patterns might be more important when studying ecological interactions.
Occurrence of Rickettsia spp., Hantaviridae, Bartonella spp. and Leptospira spp. in European Moles (Talpa europaea) from the Netherlands
Authors: Cuperus Tryntsje , de Vries Ankje , Jaarsma Ryanne I. , Sprong Hein , Maas Miriam
Published: December 2022

The European mole (Talpa europaea) has a widespread distribution throughout Europe. However, little is known about the presence of zoonotic pathogens in European moles. We therefore tested 180 moles from the middle and the south of the Netherlands by (q)PCR for the presence of multiple (tick-borne) zoonotic pathogens. Spotted fever Rickettsia was found in one (0.6%), Leptospira spp. in three (1.7%), Bartonella spp. in 69 (38.3%) and Hantaviridae in 89 (49.4%) of the 180 moles. Infections with Anaplasma phagocytophilum, Babesia spp., Neoehrlichia mikurensis, Borrelia spp., Spiroplasma spp. and Francisella tularensis were not found. In addition, in a subset of 35 moles no antibodies against Tick-borne encephalitis virus were found. The obtained sequences of Bartonella spp. were closely related to Bartonella spp. sequences from moles in Spain and Hungary. The Hantaviridae were identified as the mole-borne Nova virus, with high sequence similarity to sequences from other European countries, and Bruges virus. Though the zoonotic risk from moles appears limited, our results indicate that these animals do play a role in multiple host-pathogen cycles.
Lewis Acid-Catalyzed Formal (4+2)-Cycloaddition between Cross-Conjugated Azatrienes and Styrylmalonates: The Way to Functionalized Quinolizidine Precursors
Authors: Sergeev Pavel G. , Novikov Roman A. , Tomilov Yury V.
Published: December 2022

Quinolizidine and azaphenalene alkaloids are common in nature and exhibit a pharmaceutical activity, which stirs up increased interest in expanding the range of methods for the synthesis of the corresponding derivatives. In this work, we attempted to adapt our previously presented method for the synthesis of tetrahydropyridines to the preparation of potential precursors for these heterocycles as a separate development of a necessary intermediate stage. To this end, we studied the reactions of β-styrylmalonates with N-protected cross-conjugated azatrienes in the presence of Sn(OTf)2. Moreover, the regioselectivity of the process involving unsymmetrically substituted azatrienes was estimated. The diene character of vinyltetrahydropyridines was studied in detail with the participation of PTAD. Finally, for the Ts-protected highly functionalized vinyltetrahydropyridines synthesized, a detosylation method to give new desired azadiene structures as precursors of the quinolizidine core was suggested.
Effect of Chicken Egg White-Derived Peptide and Hydrolysates on Abnormal Skin Pigmentation during Wound Recovery
Authors: Yap Pei-Gee , Gan Chee-Yuen , Naharudin Idanawati , Wong Tin-Wui
Published: December 2022

Abnormal skin pigmentation commonly occurs during the wound healing process due to the overproduction of melanin. Chicken egg white (CEW) has long been used to improve skin health. Previous published works had found CEW proteins house bioactive peptides that inhibit tyrosinase, the key enzyme of melanogenesis. The current study aimed to evaluate the anti-pigmentation potential and mechanism of the CEW-derived peptide (GYSLGNWVCAAK) and hydrolysates (CEWHmono and CEWHdi), using a cell-based model. All of these peptide and hydrolysates inhibited intracellular tyrosinase activity and melanin level up to 45.39 ± 1.31 and 70.01 ± 1.00%, respectively. GYSLGNWVCAAK and CEWHdi reduced intracellular cAMP levels by 13.38 ± 3.65 and 14.55 ± 2.82%, respectively; however, CEWHmono did not affect cAMP level. Moreover, the hydrolysates downregulated the mRNA expression of melanogenesis-related genes, such as Mitf, Tyr, Trp-1 and Trp-2, but GYSLGNWVCAAK only suppressed Tyr gene expression. Downregulation of the genes may lower the catalytic activities and/or affect the structural stability of TYR, TRP-1 and TRP-2; thus, impeding melanogenesis to cause an anti-pigmentation effect in the cell. Outcomes from the current study could serve as the starting point to understand the underlying complex, multifaceted melanogenesis regulatory mechanism at the cellular level.
GC-MS and LC-DAD-MS Phytochemical Profiling for Characterization of Three Native Salvia Taxa from Eastern Mediterranean with Antiglycation Properties
Authors: Gkioni Maria D. , Zeliou Konstantina , Dimaki Virginia D. , Trigas Panayiotis , Lamari Fotini N.
Published: December 2022

Salvia fruticosa and S. pomifera subsp. calycina are native to Eastern Mediterranean and S. pomifera subsp. pomifera is endemic to Greece. The primary aim of this study was to develop an analytical methodology for metabolomic profiling and to study their efficacy in combating glycation, the major biochemical complication of diabetes. After sequential ultrasound-assisted extraction of 2 g of leaves with petroleum ether and 70% methanol, the volatile metabolites in the petroleum ether extracts were studied with GC-MS (Gas Chromatography-Mass Spectrometry), whereas the polar metabolites in the hydroalcoholic extracts were determined and quantified by UHPLC-DAD–ESI-MS (Ultra-High Performance Liquid Chromatography–Diode Array Detector–Mass Spectrometry). This methodology was applied to five populations belonging to the three native taxa. 1,8-Cineole was the predominant volatile (34.8–39.0%) in S. fruticosa, while S. pomifera had a greater content of α-thujone (19.7–41.0%) and β-thujone (6.0–39.1%). Principal Component Analysis (PCA) analysis of the volatiles could discriminate the different taxa. UHPLC-DAD-ESI-MS demonstrated the presence of 50 compounds, twenty of which were quantified. PCA revealed that not only the taxa but also the populations of S. pomifera subsp. pomifera could be differentiated. All Salvia samples inhibited advanced glycation end-product formation in a bovine serum albumin/2-deoxyribose assay; rosmarinic and carnosic acid shared this activity. This study demonstrates the antiglycation activity of S. fruticosa and S. pomifera extracts for the first time and presents a miniaturized methodology for their metabolomic profiling, which could aid chemotaxonomic studies and serve as a tool for their authentication and quality control.