The 2023 MDPI Annual Report has
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24 pages, 990 KiB  
Article
Phenotypic Diversity of Pomegranate Cultivars: Discriminating Power of Some Morphological and Fruit Chemical Characteristics
by Mira Radunić, Maja Jukić Špika and Jelena Gadže
Horticulturae 2024, 10(6), 563; https://doi.org/10.3390/horticulturae10060563 (registering DOI) - 28 May 2024
Abstract
In modern agricultural production, where a small number of commercial cultivars dominate, the collection, evaluation, and preservation of germplasm are important tasks to reduce the erosion of genes and preserve biodiversity. The aim of this study is to characterize the morphological and fruit [...] Read more.
In modern agricultural production, where a small number of commercial cultivars dominate, the collection, evaluation, and preservation of germplasm are important tasks to reduce the erosion of genes and preserve biodiversity. The aim of this study is to characterize the morphological and fruit chemical properties of the pomegranate germplasm grown on the East Adriatic coast, including the commercial cultivars ‘Hicaznar’, ‘Granada’, and ‘Wonderful’, and to highlight the characteristics with the greatest discriminating power. The characterization of the tree, leaf, flower, arils, seed, and juice was carried out using the UPOV descriptor. The colors of the peel, arils, and juice were analyzed according to the CIEL*a*b* method, total soluble solids were measured using refractometers, and total acidity was determined by titration with 0.1 M NaOH. The research results showed significant diversity between the cultivars, which were grouped into several clusters using an unsupervised analysis technique. Factors such as plant vigor, plant growth habit, predominant number of leaves per node on young shoots, crown type, fruit shape, fruit shape in cross-section, peel weight, total aril weight, aril weight, number of arils per fruit, seed length and width, seed yield, total acidity, TSS/TA ratio, and color parameters of the peel, arils, and juice showed high variability, indicating their strong discriminating power in determining the phenotypic diversity of pomegranate. Full article
(This article belongs to the Special Issue Research on Pomegranate Germplasm, Breeding, Genetics and Multiomics)
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13 pages, 1252 KiB  
Article
Challenges of the Application of In Vitro Digestion for Nanomaterials Safety Assessment
by Nádia Vital, Ana Catarina Gramacho, Mafalda Silva, Maria Cardoso, Paula Alvito, Michel Kranendonk, Maria João Silva and Henriqueta Louro
Foods 2024, 13(11), 1690; https://doi.org/10.3390/foods13111690 (registering DOI) - 28 May 2024
Abstract
Considering the increase in the production and use of nanomaterials (NM) in food/feed and food contact materials, novel strategies for efficient and sustainable hazard characterization, especially in the early stages of NM development, have been proposed. Some of these strategies encompass the utilization [...] Read more.
Considering the increase in the production and use of nanomaterials (NM) in food/feed and food contact materials, novel strategies for efficient and sustainable hazard characterization, especially in the early stages of NM development, have been proposed. Some of these strategies encompass the utilization of in vitro simulated digestion prior to cytotoxic and genotoxic assessment. This entails exposing NM to fluids that replicate the three successive phases of digestion: oral, gastric, and intestinal. Subsequently, the resulting digestion products are added to models of intestinal cells to conduct toxicological assays, analyzing multiple endpoints. Nonetheless, exposure of intestinal cells to the digested products may induce cytotoxicity effects, thereby posing a challenge to this strategy. The aim of this work was to describe the challenges encountered with the in vitro digestion INFOGEST 2.0 protocol when using the digestion product in toxicological studies of NM, and the adjustments implemented to enable its use in subsequent in vitro biological assays with intestinal cell models. The adaptation of the digestion fluids, in particular the reduction of the final bile concentration, resulted in a reduced toxic impact of digestion products. Full article
(This article belongs to the Special Issue Prospects for Risks and Benefits in the Context of Food and Health)
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20 pages, 7771 KiB  
Article
Active Vibration Avoidance Method for Variable Speed Welding in Robotic Friction Stir Welding Based on Constant Heat Input
by Guanchen Zong, Cunfeng Kang and Shujun Chen
Materials 2024, 17(11), 2593; https://doi.org/10.3390/ma17112593 (registering DOI) - 28 May 2024
Abstract
Robotic Friction Stir Welding (RFSW) technology integrates the advantages of friction stir welding and industrial robots, finding extensive applications and research in aerospace, shipbuilding, and new energy vehicles. However, the high-speed rotational process of friction stir welding combined with the low stiffness characteristics [...] Read more.
Robotic Friction Stir Welding (RFSW) technology integrates the advantages of friction stir welding and industrial robots, finding extensive applications and research in aerospace, shipbuilding, and new energy vehicles. However, the high-speed rotational process of friction stir welding combined with the low stiffness characteristics of serial industrial robots inevitably introduces vibrations during the welding process. This paper investigates the vibration patterns and impacts during the RFSW process and proposes an active vibration avoidance control method for variable speed welding based on constant heat input. This method utilizes a vibration feedback strategy that adjusts the spindle speed actively if the end-effector’s vibration exceeds a threshold, thereby avoiding the modal frequencies of the robot at its current pose. Concurrently, it calculates and adjusts the welding speed of the robot according to the thermal equilibrium equation to maintain constant heat input. A simplified dynamic model of the RFSW robot was established, and the feasibility of this method was validated through simulation experiments. This study fills the gap in vibration analysis of RFSW and provides new insights into control strategies and process optimization for robotic friction stir welding. Full article
(This article belongs to the Topic Development of Friction Stir Welding and Processing)
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14 pages, 1007 KiB  
Article
Phenotype, Biomass, Carbon and Nitrogen Assimilation, and Antioxidant Response of Rapeseed under Salt Stress
by Long Wang, Guobing Lin, Yiyang Li, Wenting Qu, Yan Wang, Yaowei Lin, Yihang Huang, Jing Li, Chen Qian, Guang Yang and Qingsong Zuo
Plants 2024, 13(11), 1488; https://doi.org/10.3390/plants13111488 (registering DOI) - 28 May 2024
Abstract
Salt stress is one of the major adverse factors affecting plant growth and crop production. Rapeseed is an important oil crop, providing high-quality edible oil for human consumption. This experiment was conducted to investigate the effects of salt stress on the phenotypic traits [...] Read more.
Salt stress is one of the major adverse factors affecting plant growth and crop production. Rapeseed is an important oil crop, providing high-quality edible oil for human consumption. This experiment was conducted to investigate the effects of salt stress on the phenotypic traits and physiological processes of rapeseed. The soil salinity was manipulated by setting three different levels: 0 g NaCl kg−1 soil (referred to as S0), 1.5 g NaCl kg−1 soil (referred to as S1), and 3.0 g NaCl kg−1 soil (referred to as S2). In general, the results indicated that the plant height, leaf area, and root neck diameter decreased with an increase in soil salinity. In addition, the biomass of various organs at all growth stages decreased as soil salinity increased from S0 to S2. The increasing soil salinity improved the distribution of biomass in the root and leaf at the seedling and flowering stages, indicating that rapeseed plants subjected to salt stress during the vegetative stage are capable of adapting their growth pattern to sustain their capacity for nutrient and water uptake, as well as leaf photosynthesis. However, as the soil salinity increased, there was a decrease in the distribution of biomass in the pod and seed at the maturity stage, while an increase was observed in the root and stem, suggesting that salt stress inhibited carbohydrate transport into reproductive organs. Moreover, the C and N accumulation at the flowering and maturity stages exhibited a reduction in direct correlation with the increase in soil salinity. High soil salinity resulted in a reduction in the C/N, indicating that salt stress exerted a greater adverse effect on C assimilation compared to N assimilation, leading to an increase in seed protein content and a decrease in oil content. Furthermore, as soil salinity increased from S0 to S2, the activity of superoxide dismutase (SOD) and catalase (CAT) and the content of soluble protein and sugar increased by 58.39%, 33.38%, 15.57%, and 13.88% at the seedling stage, and 38.69%, 22.85%, 12.04%, and 8.26% at the flowering stage, respectively. In summary, this study revealed that salt stress inhibited C and N assimilation, leading to a suppressed phenotype and biomass accumulation. The imbalanced C and N assimilation under salt stress contributed to the alterations in the seed oil and protein content. Rapeseed had a certain degree of salt tolerance by improving antioxidants and osmolytes. Full article
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18 pages, 10711 KiB  
Article
Human-Centered Design and Manufacturing of a Pressure-Profile-Based Pad for Better Car Seat Comfort
by Alessandro Naddeo, Alfonso Morra and Rosaria Califano
Machines 2024, 12(6), 374; https://doi.org/10.3390/machines12060374 (registering DOI) - 28 May 2024
Abstract
A car seat’s function is to support, protect, and make passengers and drivers feel comfortable during a trip. A more uniform pressure distribution and a larger contact area usually provide less discomfort. Consequently, the seat pan’s material and geometry play an essential role [...] Read more.
A car seat’s function is to support, protect, and make passengers and drivers feel comfortable during a trip. A more uniform pressure distribution and a larger contact area usually provide less discomfort. Consequently, the seat pan’s material and geometry play an essential role in the design process. A shaped pad was opportunely designed and realized, starting from the pressure distributions between the buttocks and the seat pan; pressure data were acquired during an initial experiment involving 41 people, representing a wide range of percentiles. The shaped pad was compared with a standard one by building a special seat with an interchangeable internal pad and testing the standard and the new seat; the second experiment involved 52 people that tested both seats. The tests were conducted to assess comfort (33 subjects were asked to be seated for 1 min each) and discomfort (19 subjects were asked to be seated for 15 min each); during the tests, pressure distribution and contact area data were gathered. The results showed that, for both tests, about 80% of the participants, among which 100% of the female sample, preferred the shaped seat pan pad. Even if the material was exactly the same, the shaped pad seemed to be softer, more comfortable, and more suited to the body’s shape than the standard one. The design methodology was demonstrated to be very useful for granting a more uniform pressure distribution and a wider contact area, i.e., higher comfort and less discomfort. Full article
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20 pages, 17703 KiB  
Article
Development of an In-Pipe Inspection Robot for Large-Diameter Water Pipes
by Kwang-Woo Jeon, Eui-Jung Jung, Jong-Ho Bae, Sung-Ho Park, Jung-Jun Kim, Goobong Chung, Hyun-Joon Chung and Hak Yi
Sensors 2024, 24(11), 3470; https://doi.org/10.3390/s24113470 (registering DOI) - 28 May 2024
Abstract
This paper describes the development of an in-pipe inspection robot system designed for large-diameter water pipes. The robot is equipped with a Magnetic Flux Leakage (MFL) sensor module. The robot system is intended for pipes with diameters ranging from 900 mm to 1200 [...] Read more.
This paper describes the development of an in-pipe inspection robot system designed for large-diameter water pipes. The robot is equipped with a Magnetic Flux Leakage (MFL) sensor module. The robot system is intended for pipes with diameters ranging from 900 mm to 1200 mm. The structure of the in-pipe inspection robot consists of the front and rear driving parts, with the inspection module located centrally. The robot is powered by 22 motors, including eight wheels with motors positioned at both the bottom and the top for propulsion. To ensure that the robot’s center aligns with that of the pipeline during operation, lifting units have been incorporated. The robot is equipped with cameras and LiDAR sensors at the front and rear to monitor the internal environment of the pipeline. Pipeline inspection is conducted using the MFL inspection modules, and the robot’s driving mechanism is designed to execute spiral maneuvers while maintaining contact with the pipeline surface during rotation. The in-pipe inspection robot is configured with wireless communication modules and batteries, allowing for wireless operation. Following its development, the inspection robot underwent driving experiments in actual pipelines to validate its performance. The field test bed used for these experiments is approximately 1 km in length. Results from the driving experiments on the field test bed confirmed the robot’s ability to navigate various curvatures and obstacles within the pipeline. It is posited that the use of the developed in-pipe inspection robot can reduce economic costs and enhance the safety of inspectors when examining aging pipes. Full article
(This article belongs to the Special Issue Intelligent Autonomous System)
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18 pages, 4732 KiB  
Article
Synthesis and Characterization of Multiple Stimuli-Responsive Fluorescent Polymer Hydrogels Based on Terpyridine and N-isopropylacrylamide
by Zihan Ma, Longhao Zhao, Chunhua Xie, Xianjian Wang, Ziyuan He and Xuegang Chen
Polymers 2024, 16(11), 1519; https://doi.org/10.3390/polym16111519 (registering DOI) - 28 May 2024
Abstract
A series of stimuli-responsive fluorescent hydrogels were successfully synthesized via micelle radical copolymerization of hydrophilic acrylamide (AM), hydrophobic chromophore terpyridine-based monomer (TPY), and N-isopropylacrylamide (NIPAM). These hydrogels presented blue emissions (423–440 nm) under room temperature, which is caused by the π-π* transition [...] Read more.
A series of stimuli-responsive fluorescent hydrogels were successfully synthesized via micelle radical copolymerization of hydrophilic acrylamide (AM), hydrophobic chromophore terpyridine-based monomer (TPY), and N-isopropylacrylamide (NIPAM). These hydrogels presented blue emissions (423–440 nm) under room temperature, which is caused by the π-π* transition of the conjugated structures. Once the ambient temperature was increased to 55 °C, the fluorescence color changed from blue (430 nm) to pink (575 nm) within 10 min, subsequently to yellow (535 nm), and eventually back to pink. The thermal-responsive properties are attributed to the transition of the TPY units from unimer to dimer aggregation via the intermolecular charge transfer complex at high temperatures. The hydrogels showed pH-responsive properties. The emission peak of the hydrogel exhibited a blue shift of ~54 nm from neuter conditions to acidic conditions, while a 6 nm red shift to an alkaline environment was observed. The hydrogels demonstrated an obvious change in fluorescence intensity and wavelength upon adding different metal ions, which is caused by the coordination between the terpyridine units incorporated on the backbones and the metal ions. As a consequence, the hydrogels presented a sharp quenching fluorescence interaction with Fe2+, Fe3+, Cu2+, Hg2+, Ni2+, and Co2+, while it exhibited an enhanced fluorescence intensity interaction with Sn2+, Cd2+, and Zn2+. The microstructural, mechanical, and rheological properties of these luminescent hydrogels have been systematically investigated. Full article
(This article belongs to the Special Issue Applications of Polymer-Based Absorbent Materials)
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24 pages, 14567 KiB  
Article
Penetration Characteristics of Mono-Column Composite Bucket Foundation for Offshore Wind Turbines
by Jiandong Xiao, Xiaoqiang Gu, Yifeng Lin, Haifeng Cheng, Xin Qi, Puyang Zhang and Shuyang Wang
J. Mar. Sci. Eng. 2024, 12(6), 897; https://doi.org/10.3390/jmse12060897 (registering DOI) - 28 May 2024
Abstract
To address the issue of seepage and soil plugging during the sinking of mono-column composite bucket foundations (MCCBFs), experiments were conducted on the installation of foundations under a variety of complex geological conditions. The effect of negative pressure sinking mode on the foundation’s [...] Read more.
To address the issue of seepage and soil plugging during the sinking of mono-column composite bucket foundations (MCCBFs), experiments were conducted on the installation of foundations under a variety of complex geological conditions. The effect of negative pressure sinking mode on the foundation’s seepage field was analyzed, the formation mechanism of soil plugging in sand was explained, and an efficient method for calculating the height of soil plugging was proposed in conjunction with these investigations. The findings demonstrate that the finite element method simulation of the soil’s seepage field is the most accurate, that the pumping volume of the foundation during sinking through is high, that the formation of the soil plug height is high, and that clear depressions can be seen on the foundation manifold’s exterior. The equation presented in this study makes it easier to forecast the height of a foundation plug and can offer direction for engineering design. Full article
(This article belongs to the Section Ocean Engineering)
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18 pages, 951 KiB  
Article
A Ciphertext Reduction Scheme for Garbling an S-Box in an AES Circuit with Minimal Online Time
by Xu Yan, Bin Lian, Yunhao Yang, Xiaotie Wang, Jialin Cui, Xianghong Zhao, Fuqun Wang and Kefei Chen
Symmetry 2024, 16(6), 664; https://doi.org/10.3390/sym16060664 (registering DOI) - 28 May 2024
Abstract
The secure computation of symmetric encryption schemes using Yao’s garbled circuits, such as AES, allows two parties, where one holds a plaintext block m and the other holds a key k, to compute Enc(k,m) without [...] Read more.
The secure computation of symmetric encryption schemes using Yao’s garbled circuits, such as AES, allows two parties, where one holds a plaintext block m and the other holds a key k, to compute Enc(k,m) without leaking m and k to one another. Due to its wide application prospects, secure AES computation has received much attention. However, the evaluation of AES circuits using Yao’s garbled circuits incurs substantial communication overhead. To further improve its efficiency, this paper, upon observing the special structures of AES circuits and the symmetries of an S-box, proposes a novel ciphertext reduction scheme for garbling an S-box in the last SubBytes step. Unlike the idea of traditional Yao’s garbled circuits, where the circuit generator uses the input wire labels to encrypt the corresponding output wire labels, our garbling scheme uses the input wire labels of an S-box to encrypt the corresponding “flip bit strings”. This approach leads to a significant performance improvement in our garbling scheme, which necessitates only 28 ciphertexts to garble an S-box and a single invocation of a cryptographic primitive for decryption compared to the best result in previous work that requires 8×28 ciphertexts to garble an S-box and multiple invocations of a cryptographic primitive for decryption. Crucially, the proposed scheme provides a new idea to improve the performance of Yao’s garbled circuits. We analyze the security of the proposed scheme in the semi-honest model and experimentally verify its efficiency. Full article
(This article belongs to the Special Issue New Advances in Symmetric Cryptography)
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30 pages, 27023 KiB  
Article
Sequential Infection with Influenza A Virus Followed by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Leads to More Severe Disease and Encephalitis in a Mouse Model of COVID-19
by Jordan J. Clark, Rebekah Penrice-Randal, Parul Sharma, Xiaofeng Dong, Shaun H. Pennington, Amy E. Marriott, Stefano Colombo, Andrew Davidson, Maia Kavanagh Williamson, David A. Matthews, Lance Turtle, Tessa Prince, Grant L. Hughes, Edward I. Patterson, Ghada Shawli, Daniele F. Mega, Krishanthi Subramaniam, Jo Sharp, Joseph D. Turner, Giancarlo A. Biagini, Andrew Owen, Anja Kipar, Julian A. Hiscox and James P. Stewartadd Show full author list remove Hide full author list
Viruses 2024, 16(6), 863; https://doi.org/10.3390/v16060863 (registering DOI) - 28 May 2024
Abstract
COVID-19 is a spectrum of clinical symptoms in humans caused by infection with SARS-CoV-2. The coalescence of SARS-CoV-2 with seasonal respiratory viruses, particularly influenza viruses, is a global health concern. To understand this, transgenic mice expressing the human ACE2 receptor (K18-hACE2) were infected [...] Read more.
COVID-19 is a spectrum of clinical symptoms in humans caused by infection with SARS-CoV-2. The coalescence of SARS-CoV-2 with seasonal respiratory viruses, particularly influenza viruses, is a global health concern. To understand this, transgenic mice expressing the human ACE2 receptor (K18-hACE2) were infected with influenza A virus (IAV) followed by SARS-CoV-2 and the host response and effect on virus biology was compared to K18-hACE2 mice infected with IAV or SARS-CoV-2 alone. The sequentially infected mice showed reduced SARS-CoV-2 RNA synthesis, yet exhibited more rapid weight loss, more severe lung damage and a prolongation of the innate response compared to the singly infected or control mice. Sequential infection also exacerbated the extrapulmonary encephalitic manifestations associated with SARS-CoV-2 infection. Conversely, prior infection with a commercially available, multivalent live-attenuated influenza vaccine (Fluenz Tetra) elicited the same reduction in SARS-CoV-2 RNA synthesis, albeit without the associated increase in disease severity. This suggests that the innate immune response stimulated by IAV inhibits SARS-CoV-2. Interestingly, infection with an attenuated, apathogenic influenza vaccine does not result in an aberrant immune response and enhanced disease severity. Taken together, the data suggest coinfection (‘twinfection’) is deleterious and mitigation steps should be instituted as part of the comprehensive public health and management strategy of COVID-19. Full article
(This article belongs to the Section Animal Viruses)
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14 pages, 339 KiB  
Article
Begging for Knowledge in Senegal: Conflicting Understandings and Interests of the Dominant Anti-Trafficking Approach and Quranic Education
by Hamadou Boiro and Jónína Einarsdóttir
Soc. Sci. 2024, 13(6), 288; https://doi.org/10.3390/socsci13060288 (registering DOI) - 28 May 2024
Abstract
Diverse actors, including foreign and national states, international agencies, donors, non-governmental organisations (NGOs), and private ventures, demand, fund, and implement anti-trafficking activities worldwide. Bissau-Guinean Quran schoolboys begging in Senegalese cities are defined as victims of child trafficking, and their teachers as traffickers. This [...] Read more.
Diverse actors, including foreign and national states, international agencies, donors, non-governmental organisations (NGOs), and private ventures, demand, fund, and implement anti-trafficking activities worldwide. Bissau-Guinean Quran schoolboys begging in Senegalese cities are defined as victims of child trafficking, and their teachers as traffickers. This article aims to explore the Quran teachers’ understanding of begging and their response to being accused of child trafficking. It rests on data collected during anthropological fieldwork in Guinea-Bissau and Senegal since 2009, including interviews and participation in religious events. The Quran teachers, some of whom admit colleagues might exploit their students, highlight four aspects of begging: allowing poor populations economically to study the Quran; contributing to humbleness, humility, and empathy with underprivileged groups; redistributing resources across generations; and allowing the acquisition of knowledge, liberation, and power. They maintain that the NGOs are profiting from funds provided to “rescue” the students and act as real traffickers, and together with funders, they aim to eliminate Islam. Embedded in layers of coloniality, the Quran teachers keep their position as community leaders. Banning begging is bound to fail if the anti-trafficking NGOs ignore their understanding of meaningful suffering and begging, including the economic and religious aspects of alms-seeking and its reciprocal nature. Full article
(This article belongs to the Special Issue International Counter-Trafficking: A Zero-Sum Game?)
19 pages, 13981 KiB  
Article
MCML-BF: A Metal-Column Embedded Microstrip Line Transmission Structure with Bias Feeders for Beam-Scanning Leakage Antenna Design
by Shunhu Hou, Shengliang Fang, Youchen Fan, Yuhai Li, Zhao Ma and Jinming Li
Sensors 2024, 24(11), 3467; https://doi.org/10.3390/s24113467 (registering DOI) - 28 May 2024
Abstract
This article proposes a novel fixed-frequency beam scanning leakage antenna based on a liquid crystal metamaterial (LCM) and adopting a metal column embedded microstrip line (MCML) transmission structure. Based on the microstrip line (ML) transmission structure, it was observed that by adding two [...] Read more.
This article proposes a novel fixed-frequency beam scanning leakage antenna based on a liquid crystal metamaterial (LCM) and adopting a metal column embedded microstrip line (MCML) transmission structure. Based on the microstrip line (ML) transmission structure, it was observed that by adding two rows of metal columns in the dielectric substrate, electromagnetic waves can be more effectively transmitted to reduce dissipation, and attenuation loss can be lowered to improve energy radiation efficiency. This antenna couples TEM mode electromagnetic waves into free space by periodically arranging 72 complementary split ring resonators (CSRRs). The LC layer is encapsulated in the transmission medium between the ML and the metal grounding plate. The simulation results show that the antenna can achieve a 106° continuous beam turning from reverse −52° to forward 54° at a frequency of 38 GHz with the holographic principle. In practical applications, beam scanning is achieved by applying a DC bias voltage to the LC layer to adjust the LC dielectric constant. We designed a sector-blocking bias feeder structure to minimize the impact of RF signals on the DC source and avoid the effect of DC bias on antenna radiation. Further comparative experiments revealed that the bias feeder can significantly diminish the influence between the two sources, thereby reducing the impact of bias voltage introduced by LC layer feeding on antenna performance. Compared with existing approaches, the antenna array simultaneously combines the advantages of high frequency band, high gain, wide beam scanning range, and low loss. Full article
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11 pages, 8689 KiB  
Article
Investigation of Synthesis, Characterization, and Finishing Applications of Spherical Al2O3 Magnetic Abrasives via Plasma Molten Metal Powder and Powder Jetting
by Shujun Wang, Yusheng Zhang, Shuo Meng, Yugang Zhao and Jianbing Meng
Micromachines 2024, 15(6), 709; https://doi.org/10.3390/mi15060709 (registering DOI) - 28 May 2024
Abstract
Magnetic abrasive finishing (MAF) is an efficient finishing process method using magnetic abrasive particles (MAPs) as finishing tools. In this study, two iron-based alumina magnetic abrasives with different particle size ranges were synthesized by the plasma molten metal powder and powder jetting method. [...] Read more.
Magnetic abrasive finishing (MAF) is an efficient finishing process method using magnetic abrasive particles (MAPs) as finishing tools. In this study, two iron-based alumina magnetic abrasives with different particle size ranges were synthesized by the plasma molten metal powder and powder jetting method. Characterization of the magnetic abrasives in terms of microscopic morphology, phase composition, magnetic permeability, particle size distribution, and abrasive ability shows that the magnetic abrasives are spherical in shape, that the hard abrasives are combined in the surface layer of the iron matrix and remain sharp, and that the hard abrasives combined in the surface layer of the magnetic abrasives with smaller particle sizes are sparser than those of the magnetic abrasives with larger particle sizes. The magnetic abrasives are composed of α-Fe and Al2O3; the magnetic permeability of the magnetic abrasives having smaller particle sizes is slightly higher than that of the magnetic abrasives having larger particle sizes; the two magnetic abrasives are distributed in a range of different particle sizes; the magnetic abrasives have different magnetic permeabilities, which are higher than those of the larger ones; both magnetic abrasives are distributed in the range of smaller particle sizes; and AZ31B alloy can obtain smaller surface roughness of the workpiece after the grinding process of the magnetic abrasives with a small particle size. Full article
(This article belongs to the Special Issue Advanced Manufacturing Technology and Systems, 3rd Edition)
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11 pages, 3014 KiB  
Article
An Ecosystem for the Provision of Digital Accessibility for People with Special Needs
by Galina Bogdanova, Todor Todorov, Nikolay Noev, Negoslav Sabev, Neda Chehlarova, Mirena Todorova-Ekmekci and Aleksandar Krastev
Information 2024, 15(6), 315; https://doi.org/10.3390/info15060315 (registering DOI) - 28 May 2024
Abstract
Digital technologies occupy an important place in today’s developing world. They are also strongly related to new trends in educational technologies. In this context, the digital accessibility of this new environment for people with various special needs is of particular concern. A novel [...] Read more.
Digital technologies occupy an important place in today’s developing world. They are also strongly related to new trends in educational technologies. In this context, the digital accessibility of this new environment for people with various special needs is of particular concern. A novel tool for assessment of the technological ecosystem, designed to provide digital accessibility to people with special needs, is described in the paper. The overall structure and the initial test of the system are discussed in the paper. The conceptual framework of the ecosystem and its ontological model are described. Special attention is paid to the accessibility of digital learning and e-learning for people with special needs from a robotic perspective. Full article
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27 pages, 18300 KiB  
Article
Statistical Analysis of Bubble Parameters from a Model Bubble Column with and without Counter-Current Flow
by P. Kováts and K. Zähringer
Fluids 2024, 9(6), 126; https://doi.org/10.3390/fluids9060126 (registering DOI) - 28 May 2024
Abstract
Bubble columns are widely used in numerous industrial processes because of their advantages in operation, design, and maintenance compared to other multiphase reactor types. In contrast to their simple design, the generated flow conditions inside a bubble column reactor are quite complex, especially [...] Read more.
Bubble columns are widely used in numerous industrial processes because of their advantages in operation, design, and maintenance compared to other multiphase reactor types. In contrast to their simple design, the generated flow conditions inside a bubble column reactor are quite complex, especially in continuous mode with counter-current liquid flow. For the design and optimization of such reactors, precise numerical simulations and modelling are needed. These simulations and models have to be validated with experimental data. For this reason, experiments were carried out in a laboratory-scale bubble column using shadow imaging and particle image velocimetry (PIV) techniques with and without counter-current liquid flow. In the experiments, two types of gases—relatively poorly soluble air and well-soluble CO2—were used and the bubbles were generated with three different capillary diameters. With changing gas and liquid flow rates, overall, 108 different flow conditions were investigated. In addition to the liquid flow fields captured by PIV, shadow imaging data were also statistically evaluated in the measurement volume and bubble parameters such as bubble diameter, velocity, aspect ratio, bubble motion direction, and inclination. The bubble slip velocity was calculated from the measured liquid and bubble velocities. The analysis of these parameters shows that the counter-current liquid flow has a noticeable influence on the bubble parameters, especially on the bubble velocity and motion direction. In the case of CO2 bubbles, remarkable bubble shrinkage was observed with counter-current liquid flow due to the enhanced mass transfer. The results obtained for bubble aspect ratio are compared to known correlations from the literature. The comprehensive and extensive bubble data obtained in this study will now be used as a source for the development of correlations needed in the validation of numerical simulations and models. The data are available from the authors on request. Full article
(This article belongs to the Special Issue Mass Transfer in Multiphase Reactors)
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13 pages, 1495 KiB  
Article
Concomitant Botulinum Toxin Injections for Neurogenic Detrusor Overactivity and Spasticity—A Retrospective Analysis of Practice and Safety
by Arnaud Leilaz, Charles Joussain, Pierre Denys, Djamel Bensmail and Jonathan Levy
Toxins 2024, 16(6), 252; https://doi.org/10.3390/toxins16060252 (registering DOI) - 28 May 2024
Abstract
As multiple indications for botulinum toxin injections (BTIs) can coexist for neurological patients, there are to date no description of concomitant injections (CIs) to treat both spasticity and neurogenic detrusor overactivity incontinence (NDOI) in patients with spinal cord injuries (SCIs) and multiple sclerosis [...] Read more.
As multiple indications for botulinum toxin injections (BTIs) can coexist for neurological patients, there are to date no description of concomitant injections (CIs) to treat both spasticity and neurogenic detrusor overactivity incontinence (NDOI) in patients with spinal cord injuries (SCIs) and multiple sclerosis (MS). We therefore identified patients followed at our institution by health data hub digging, using a specific procedure coding system in use in France, who have been treated at least once with detrusor and skeletal muscle BTIs within the same 1-month period, over the past 5 years (2017–2021). We analyzed 72 patients representing 319 CIs. Fifty (69%) were male, and the patients were mostly SCI (76%) and MS (18%) patients and were treated by a mean number of CIs of 4.4 ± 3.6 [1–14]. The mean cumulative dose was 442.1 ± 98.8 U, and 95% of CIs were performed within a 72 h timeframe. Among all CIs, five patients had symptoms evocative of distant spread but only one had a confirmed pathological jitter in single-fiber EMG. Eleven discontinued CIs for surgical alternatives: enterocystoplasty (five), tenotomy (three), intrathecal baclofen (two) and neurotomy (one). Concomitant BTIs for treating both spasticity and NDOI at the same time appeared safe when performed within a short delay and in compliance with actual knowledge for maximum doses. Full article
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21 pages, 8289 KiB  
Article
Application of Continuous Stability Control to a Lightweight Solar-Electric Vehicle Using SMC and MPC
by Anna Lidfors Lindqvist, Shilei Zhou, Benjamin Halkon, Ricardo P. Aguilera and Paul D. Walker
Vehicles 2024, 6(2), 874-894; https://doi.org/10.3390/vehicles6020042 (registering DOI) - 28 May 2024
Abstract
This paper investigates the application of contusion stability yaw control of a lightweight solar-electric vehicle. The vehicle’s customized design envelope makes it more sensitive to variations in load due to its low weight and relatively large size. To address this issue, control strategies [...] Read more.
This paper investigates the application of contusion stability yaw control of a lightweight solar-electric vehicle. The vehicle’s customized design envelope makes it more sensitive to variations in load due to its low weight and relatively large size. To address this issue, control strategies were developed using differential motor torques to generate direct yaw moments using the vehicle’s rear in-wheel motors. This paper introduces the working conditions of solar vehicles and demonstrates the necessity of stability control. Vehicle parameters such as mass and center of gravity position are obtained to apply control to the real vehicle. The paper then describes two stability control strategies, using (i) sliding-mode control (SMC) and (ii) model predictive control (MPC). To account for the road bank angle of the test area and the impact of additional weight from a driver and passenger, a Kinematic-Based Observer is designed to estimate the vehicle’s side-slip based on measured values. To collect real-time data, a dSPACE MicroAutobox was installed on the solar vehicle. The results show the effect of the observer and controllers under different vehicle speeds and load conditions. Finally, closed-loop simulation results are presented to support the findings from the open-loop testing. Full article
(This article belongs to the Topic Vehicle Dynamics and Control)
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12 pages, 476 KiB  
Article
Resolution of RHCE Haplotype Ambiguities in Transfusion Settings
by Caroline Izard, Laurine Laget, Sophie Beley, Nelly Bichel, Lugdivine De Boisgrollier, Christophe Picard, Jacques Chiaroni and Julie Di Cristofaro
Int. J. Mol. Sci. 2024, 25(11), 5868; https://doi.org/10.3390/ijms25115868 (registering DOI) - 28 May 2024
Abstract
Red blood cell (RBC) transfusion, limited by patient alloimmunization, demands accurate blood group typing. The Rh system requires specific attention due to the limitations of serological phenotyping methods. Although these have been compensated for by molecular biology solutions, some RhCE ambiguities remain unresolved. [...] Read more.
Red blood cell (RBC) transfusion, limited by patient alloimmunization, demands accurate blood group typing. The Rh system requires specific attention due to the limitations of serological phenotyping methods. Although these have been compensated for by molecular biology solutions, some RhCE ambiguities remain unresolved. The RHCE mRNA length is compatible with full-length analysis and haplotype discrimination, but the RHCE mRNA analyses reported so far are based on reticulocyte isolation and molecular biology protocols that are fastidious to implement in a routine context. We aim to present the most efficient reticulocyte isolation method, combined with an RT-PCR sequencing protocol that embraces the phasing of all haplotype configurations and identification of any allele. Two protocols were tested for reticulocyte isolation based either on their size/density properties or on their specific antigenicity. We show that the reticulocyte sorting method by antigen specificity from EDTA blood samples collected up to 48 h before processing is the most efficient and that the combination of an RHCE-specific RT-PCR followed by RHCE allele-specific sequencing enables analysis of cDNA RHCE haplotypes. All samples analyzed show full concordance between RHCE phenotype and haplotype sequencing. Two samples from the immunohematology laboratory with ambiguous results were successfully analyzed and resolved, one of them displaying a novel RHCE allele (RHCE*03 c.340C>T). Full article
(This article belongs to the Special Issue New Advances in Erythrocyte Biology and Functions)
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17 pages, 2165 KiB  
Review
Forty Years of HIV Research in French Guiana: Comprehend to Combat
by Mathieu Nacher, Aude Lucarelli, Astrid Van-Melle, Célia Basurko, Sébastien Rabier, Malorie Chroum, Thiago Santana, Karine Verin, Ketty Bienvenu, Myriam El Guedj, Tania Vaz, Hawa Cisse, Loïc Epelboin, Paul Le Turnier, Philippe Abboud, Félix Djossou, Roger Pradinaud, Antoine Adenis and Pierre Couppié
Pathogens 2024, 13(6), 459; https://doi.org/10.3390/pathogens13060459 (registering DOI) - 28 May 2024
Abstract
The drivers of the HIV epidemic, the viruses, the opportunistic infections, the attitudes and the resources allocated to the fight against HIV/AIDS, vary substantially across countries. French Guiana, at the crossroads between Amazonian South America and the Caribbean, constitutes a singular context with [...] Read more.
The drivers of the HIV epidemic, the viruses, the opportunistic infections, the attitudes and the resources allocated to the fight against HIV/AIDS, vary substantially across countries. French Guiana, at the crossroads between Amazonian South America and the Caribbean, constitutes a singular context with poor populations and rich country health funding, which has allowed researchers to gather lots of information on the particulars of our epidemic. We aimed to focus on the little known story of forty years of HIV research in French Guiana and emphasize how local research intertwined with public health action has yielded continuous progress, despite the difficult social conditions of the affected population. We searched Web of Science and associated local experts who worked through much of the epidemic in selecting the most meaningful products of local research for clinical and public health outcomes in French Guiana. Research tools and facilities included, from 1991 onwards, the HIV hospital cohort and the HIV-histoplasmosis cohort. Ad hoc studies funded by the ANRS or the European Regional Development fund shed light on vulnerable groups. The cumulative impact of prospective routine collection and focused efforts has yielded a breadth of knowledge, allowing for informed decisions and the adaptation of prevention, testing and care in French Guiana. After this overview, we emphasize that the close integration of research and public health was crucial in adapting interventions to the singular context of French Guiana. Full article
(This article belongs to the Special Issue Viral Infections of Humans: Epidemiology and Control)
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15 pages, 1686 KiB  
Article
Food Web Structure and Ecosystem Functions of the Water Source in the Middle Route of China’s South-to-North Water Diversion Project
by Yuanyuan Zhang, Kaidi Gu, Xinyu Wang, Ji’ao Zhang, Jiaoyang Duan, Zhongjun Hu and Qigen Liu
Fishes 2024, 9(6), 202; https://doi.org/10.3390/fishes9060202 (registering DOI) - 28 May 2024
Abstract
The Danjiangkou Reservoir is the water source of the middle route of China’s South-to-North Water Diversion Project, encompassing the Dan Reservoir and Han Reservoir. However, little is known about the ecological functions of this important ecosystem. Based on a survey conducted in 2023 [...] Read more.
The Danjiangkou Reservoir is the water source of the middle route of China’s South-to-North Water Diversion Project, encompassing the Dan Reservoir and Han Reservoir. However, little is known about the ecological functions of this important ecosystem. Based on a survey conducted in 2023 in the Dan Reservoir, a mass balance model was constructed using Ecopath with Ecosim 6.6 software to characterize its food web structure and ecosystem properties. The model consisted of 18 functional groups, including producers, consumers, and detritus, covering the entire process of energy flow in the ecosystem. The outputs indicated that the fractional trophic level of functional groups in the Dan Reservoir ecosystem ranged from 1.00 to 3.50. The ecotrophic efficiencies of the main economic fish species were all less than 0.9, and the ecotrophic efficiencies of phytoplankton and detritus were less than 0.5. There were two main food chains: the detritus food chain (39%) and the grazing food chain (61%). The total energy transfer efficiency between trophic levels was only 6.02%, and there was a significant phenomenon of energy transfer blockage between trophic levels II and V. Analysis of the overall characteristics of the ecosystem revealed that the total primary production to total biomass (67.96619), connectance index (0.274), and Finn’s cycling index (2.856) of the Dan Reservoir ecosystem all indicate that the ecosystem is immature, with low nutrient recycling efficiency and poor resistance to external disturbances. This may be related to the low proportion of silver carp and bighead carp in the reservoir and the unreasonable structure of the fish community. Our results suggest that it is necessary to scientifically adjust the structure of the fish community, enhance the proportion of filter-feeding and omnivorous fish to improve the energy flow efficiency, and promote the maturity and stability of the Dan Reservoir. Full article
(This article belongs to the Section Biology and Ecology)
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24 pages, 8302 KiB  
Article
Design of a Spherical Rover Driven by Pendulum and Control Moment Gyroscope for Planetary Exploration
by Matteo Melchiorre, Tommaso Colamartino, Martina Ferrauto, Mario Troise, Laura Salamina and Stefano Mauro
Robotics 2024, 13(6), 87; https://doi.org/10.3390/robotics13060087 (registering DOI) - 28 May 2024
Abstract
The spherical shape is an interesting approach to develop exploration robots, or rovers, thanks to its capability of ensuring omnidirectional motion and of being basically unsensitive to possible rollovers. This works intends to propose a novel detailed design for such a kind of [...] Read more.
The spherical shape is an interesting approach to develop exploration robots, or rovers, thanks to its capability of ensuring omnidirectional motion and of being basically unsensitive to possible rollovers. This works intends to propose a novel detailed design for such a kind of robot and to discuss the performance that can be reached by adopting this solution. The work hence introduces the requirements assumed for the design of the robot and discloses the general layout that was selected, which includes a pendulum for motion transmission and two coupled gyroscopes to overcome high, steep obstacles, such as steps. The paper then summarizes the functional design computation carried out to size and selects the components of the system. Eventually, a control algorithm is described and tested on a complete multibody model of the robot. The results in the execution of standard maneuvers such as motion on a horizontal plane, as well as in the overcome of a step, are shown. The energetic balance of the rover is described, and some preliminary consideration about mission planning are reported in the final discussion. Full article
(This article belongs to the Section Aerospace Robotics and Autonomous Systems)
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20 pages, 411 KiB  
Article
Language Policy and Practices in an Ethiopian University towards Multilingualism
by Keresa Kumera Chali and Andrea Parapatics
Languages 2024, 9(6), 198; https://doi.org/10.3390/languages9060198 (registering DOI) - 28 May 2024
Abstract
The study explores an Ethiopian higher education institution’s language policy and practices, explicitly focusing on multilingualism. Thе rеsеarch highlights a discrеpancy between languagе policy and classroom rеalitiеs. Despite English being officially designated as the primary instructional medium of higher education institutions, the prevalent [...] Read more.
The study explores an Ethiopian higher education institution’s language policy and practices, explicitly focusing on multilingualism. Thе rеsеarch highlights a discrеpancy between languagе policy and classroom rеalitiеs. Despite English being officially designated as the primary instructional medium of higher education institutions, the prevalent environment for teaching and learning is multilingual, incorporating Afaan Oromoo, Amharic, and other languages alongside English. This disparity challеngеs thе monolingual languagе еducation policy mandatеd by thе Ethiopian constitution. The study employs a mixed-methods approach to offer a comprehensive perspective on the issue, stressing the necessity for a more holistic understanding of the situation. Furthеrmorе, thе rеsеarch indicatеs that thе Ethiopian constitution lacks еxplicit provisions addressing multilingualism within highеr еducation institutions, rеvеaling a gap in thе lеgal framework. This misalignmеnt calls for potential policy adjustmеnts to bеttеr accommodatе thе multilingual nature of highеr еducation. Bеyond thе classroom, both instructors and studеnts frеquеntly usе Afaan Oromoo, Amharic, and othеr hеritagе languagеs in thеir intеractions, furthеr еmphasizing thе importancе of undеrstanding thеsе languagе dynamics in thе Ethiopian highеr еducation contеxt. Ovеrall, this study undеrscorеs thе nееd for a closеr еxamination of languagе practicеs and thеir implications, offеring insights into promoting morе inclusivе еducation and informеd languagе policiеs within Ethiopian highеr еducation institutions. Full article
(This article belongs to the Special Issue Linguistic Practices in Heritage Language Acquisition)
11 pages, 4053 KiB  
Article
A Simple, Robust, and Versatile MATLAB Formulation of the Dynamic Memdiode Model for Bipolar-Type Resistive Random Access Memory Devices
by Emili Salvador, Rosana Rodriguez and Enrique Miranda
J. Low Power Electron. Appl. 2024, 14(2), 30; https://doi.org/10.3390/jlpea14020030 (registering DOI) - 28 May 2024
Abstract
Modeling in an emerging technology like RRAM devices is one of the pivotal concerns for its development. In the current bibliography, most of the models face difficulties in implementing or simulating unconventional scenarios, particularly when dealing with complex input signals. In addition, circuit [...] Read more.
Modeling in an emerging technology like RRAM devices is one of the pivotal concerns for its development. In the current bibliography, most of the models face difficulties in implementing or simulating unconventional scenarios, particularly when dealing with complex input signals. In addition, circuit simulators like Spice require long running times for high-resolution results because of their internal mathematical implementation. In this work, a fast, simple, robust, and versatile model for RRAM devices built in MATLAB is presented. The proposed model is a recursive and discretized version of the dynamic memdiode model (DMM) for bipolar-type resistive switching devices originally implemented in LTspice. The DMM model basically consists of two coupled equations: one for the current (non-linear current generator) and a second one for the memory state of the device (time-dependent differential equation). This work presents an easy-to-use tool for researchers to reproduce the experimental behavior of their devices and predict the outcome from non-trivial experiments. Three study cases are reported, aimed at capturing different phenomenologies: a frequency effect study, a cycle-to-cycle variability fit, and a stochastic resonance impact analysis. Full article
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