Search

This study aims to develop and evaluate a unique 3D haptic system utilizing a gimbal mechanism and three Magneto-Rheological Brakes (MRBs). The research begins with a comprehensive literature review to propose a configuration for a 3D haptic joystick with force feedback, employing MRF actuators. The gimbal mechanism integrates the three MRBs to provide force feedback for rotational movement along the X, Y, and Z axes. The design and simulation of the MRBs are carried out using the finite element method and the Bingham plastic rheological model, with a focus on minimizing mass and production costs. To address the objective optimization problem associated with the MRBs, Particle Swarm Optimization is applied. Subsequently, a physical prototype of the 3D haptic joystick is constructed, and an evaluation is conducted to assess the feedback force. This research also paves the way for future investigations into force feedback in remote control, particularly within the context of the Master-Slave system.

This research presents a novel approach to sealing components by proposing an optimized design and experimental evaluation of a magneto-rheological fluid (MRF) sealing component for reciprocal motion, with a specific focus on MR dampers. The traditional O-ring is replaced by a continuously activated MRF seal using an axial permanent magnet. The paper begins with a comprehensive overview of previous research on the application of MR fluid in sealing and presents a proposed configuration for a MRF based seal (MRF seal shortly) for reciprocal motion. Optimal design and modeling of the MRF seal are performed through finite element analysis, and a prototype is manufactured for experimental testing. The performance characteristics of the MRF seal are thoroughly investigated based on both experimental and simulated results. The study evaluates the effectiveness of the MRF seal in terms of its sealing capability and durability. The findings of this research have potential applications across various industries that require sealing components for reciprocating motion, including automotive, aerospace, and manufacturing. By embracing this innovation, these industries can achieve significant energy savings by minimizing friction and enhancing overall operational efficiency.

In this manuscript, we first initiate several types of effective arcs of intuitionistic fuzzy directed graphs, followed by discussions on different types of dominations in intuitionistic fuzzy directed graphs and their application in decision-making. The notion of dominations in fuzzy graphs, fuzzy directed graphs, intuitionistic fuzzy graphs and picture fuzzy graphs have been extensively discussed in the literature. Thus, the work presented in our study is two-fold: on one side, it extends the notion of domination in fuzzy directed graphs, while on the other side, it fills the gap existing in the literature. Initially, we introduce several types of effective arcs like semi-λ effective arc, semi-ν effective arcs in intuitionistic fuzzy directed graphs. Subsequently, we initiate the notions of dominations and domination numbers for several types of intuitionistic fuzzy directed graphs based on these effective arcs. We present numerous significant characterizations of dominations in intuitionistic fuzzy directed graphs by utilizing minimal dominating sets. Furthermore, we investigate the minimal dominating sets and domination numbers of intuitionistic fuzzy-dipaths and dicycles, and provide various fascinating results. Finally, by utilizing the concepts presented in this study, we provide the algorithm for the solution of the problem related to decision-making regarding the opening of restaurants in various areas of the different cities.

Conamomum vietnamense is an endemic and rare species from Vietnam. The aim of this study is to determine the chemical compositions, antibacterial and antioxidant properties of the acetone extracts obtained from the different organs of this species for the first time. A total of 82 components were identified from the acetone extracts of leaf, flower, and rhizome of C. vietnamense using Gas chromatography–mass spectrometry (GC/MS) technique. Furthermore, the agar disk-diffusion method was also used to determine the antibacterial activity of the C. vietnamense extracts. Accordingly, the leaf extract was found to be effective against eight out of nine bacterial strains while the flower and rhizome extracts displayed activity against four out of nine tested bacteria. In addition, the three organs of C. vietnamense also possessed the high DPPH scavenging properties. The results of this study indicate that C. vietnamense extracts have the potential to be developed into pharmaceutical products in the future.

Many real-life problems present multiple options necessitating modern researchers to identify the most suitable choice or decision. In this context, fuzzy sets have proven to be valuable tools for addressing such problems. Picture fuzzy sets (PFSs), due to their increased flexibility and broader domain as compared to other extensions of fuzzy sets (FSs) have been extensively used in solving various decision-making problems. To achieve optimal decisions, various fuzzy graphs and fuzzy hypergraph structures are employed. Picture fuzzy directed hypergraphs (PFDHGs) offer greater utility in addressing problems with multiple options or uncertainties. In this study, we introduce novel concepts of PFDHGs, along with their applications in decision-making theory and hazardous chemicals management. Initially, we present the foundational concepts of PFDHGs, including essential terminologies such as hyper-edge and height. Subsequently, we explore various types of PFDHGs, such as simple PFDHGs and support simple PFDHGs. Additionally, we introduce the concept of $({\widetilde {\alpha }}, {\widetilde {\beta }}, {\widetilde {\gamma }})$ -level hyperarcs and elucidate the fundamental sequence in PFDHGs based on these arcs. The study further examines elementary PFDHGs, partial PFDHGs, and ordered PFDHGs, investigating the relationships among them. Structural properties of PFDHGs are analyzed through different types of homomorphisms of PFDHGs. We also define the order and size of PFDHGs. Finally, we present the applications of PFDHGs in decision-making and managing hazardous chemicals, emphasizing the innovative contributions and practical implications of our work.

ABSTRACTThis paper presents an energy-saving and lifetime-maximizing solution for the LoRa wireless mesh network (WMN). Energy dissipation is a crucial factor affecting the usability of the LoRa WMN. In the worst cases, in systems without electric mains, the life of a sensor node battery may last for only a few hours. Two proposed solutions are characterized as energy-saving due to the use of deep sleep in the ESP8266-12F microcontroller. This allows the optimization of duty cycling, which refers to the ratio between active and inactive periods of sensor nodes power-gating the node, i.e. turning off all circuitries. This solution benefits applications using active power-hungry sensors sampled many times daily. Notably, reducing power consumption during idle time increases the optimal battery life by up to hundreds of times. As a result, the automatic uptime of a LoRa WMN can increase from days to months or even years, depending on usage. Therefore, energy-saving must be optimized if the node is to be installed in locations without a grid or renewable energy source. Experimental results show that the proposed energy-saving solution is more effective than those introduced by previous studies.

We extend the so-called universal potential estimates of Kuusi-Mingione type (J. Funct. Anal. 262: 4205–4269, 2012) to the singular case $ 1 < p\leq 2-1/n $ for the quasilinear equation with measure data $ \begin{equation*} -\operatorname{div}(A(x,\nabla u)) = \mu \end{equation*} $ in a bounded open subset $ \Omega $ of $ \mathbb{R}^n $, $ n\geq 2 $, with a finite signed measure $ \mu $ in $ \Omega $. The operator $ \operatorname{div}(A(x, \nabla u)) $ is modeled after the $ p $-Laplacian $ \Delta_p u: = {\rm div}\, (|\nabla u|^{p-2}\nabla u) $, where the nonlinearity $ A(x, \xi) $ ($ x, \xi \in \mathbb{R}^n $) is assumed to satisfy natural growth and monotonicity conditions of order $ p $, as well as certain additional regularity conditions in the $ x $-variable.

Abstract Asthma with fixed airway obstruction (FAO) is associated with significant morbidity and rapid decline in lung function, making its treatment challenging. Quantitative computed tomography (QCT) along with data postprocessing is a useful tool to obtain detailed information on airway structure, parenchymal function, and computational flow features. In this study, we aim to identify the structural and functional differences between asthma with and without FAO. The FAO group was defined by a ratio of forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC), FEV1/FVC

This study investigated the chemical components and bioactivities of acetone leaf extracts of nine Annonaceae plants collected in the Binh Chau-Phuoc Buu Nature Reserve, Vietnam. A total of 182 constituents were identified, with linolenic acid, diaeudesmin, germacrene D, 1-octadecenoic acid, 8-(3-octyl-2-oxiranyl)-1-octanol, oleic acid, and phenylmethyl ester being the major compounds. The antimicrobial activity of the extracts was evaluated using a disc diffusion assay. Eight of the nine extracts, except for the Mitrephora thorelii extract, showed an inhibition effect against Bacillus cereus and Staphylococcus aureus. The antioxidant activity of the extracts was determined using DPPH assay, and the cytotoxic activity was deter mined using SRB assay. The results showed that the acetone extracts of Artabotrys hexapetalus, Uvularia grandiflora, Polyalthia luensis, Xylopia pierrei, Sphaerocoryne affinis, Desmos cochinchinensis, Uvaria littoralis, Mitrephora thorelii, and Goniothalamus touranensis had significant activity with IC50 for the DPPH radical scavenging activity ranging from 18.56 to 702.33 μg/mL, and the IC50 for the cytotoxic effects ranged from 5.39 to 251.77 μg/mL. Overall, the results obtained provide experimental evidence for the potential use of these plants in medicine and other related fields.

The main purpose of this research is to propose and empirical test a conceptual model that clarifies the relationship between green hotel practices and customer citizenship behavior (CCB) with the mediating role is green hotel image and satisfaction in the perspective of customers. To test the hypothesis this research utilizes the data collected from a questionnaire survey from tourists who have visited the Moc Chau national tourist area, Son La – a mountainous province situated in the North West of Vietnam. Finally, the authors collected 212 valid questionnaires to test the hypothesis. The testing results indicated that green hotel practices positively influence customer citizenship behavior. Moreover, green hotel image and customer satisfaction contribute as the mediating effects in the relationship between green hotel practice and customer citizenship behavior. In contrast, green hotel image and customer satisfaction do not act as the serial mediation in this relationship.

Galactorrhea is a physiologic response classically associated with gonadal-hormonal axis changes, medication side effects, and increased prolactin levels. A less common cause of galactorrhea is chest wall trauma, which includes surgical procedures affecting the chest wall. We present the case of an adolescent female with milky discharge from both breasts sixteen days after video-assisted pectus excavatum repair with intercostal nerve cryoablation. Evaluation was significant for elevated prolactin levels but otherwise unremarkable. Both the galactorrhea and elevated prolactin levels resolved without specific therapy. The etiology may be related to the surgical repair, cryoablation, or a combination of the two.

Tower crane is a multiple-input and multiple-output (MIMO) under-actuated system which is popularly used in both goods tranfering and constructing. In operating process, the loads ,which are transferred by tower crane, such as goods, material,…, are fluctuated. Fluctuation of load takes part of decreasing performance in goods transferring. In this paper, we propose a structure of PID to control tower crane to avoid this fluctuation of load. Simulation and Experimental results and demonstrate the success of PID algorithm in this research.

Solid polymer electrolytes are promising candidates for implementation in next-generation all-solid-state batteries (ASSBs) which could replace conventional batteries used today. However, the materialization of ASSBs on a mass scale is restricted by the low ionic conductivity and high interfacial resistance of solid electrolytes. In this work, succinonitrile (SN) with lithium (trifluoromethylsulphonyl)imide (LiTFSI) and Al-doped Li7La3Zr2O12 (Al-LLZO) nanoparticles were used to improve the ionic conductivity of a polyethylene oxide-based composite electrolyte. The Al-LLZO nanoparticles were synthesized by a facile synthesis process at low temperatures, which contributed to an enhancement in the ionic conductivity. A solid polymer electrolyte with 7.5 wt% of Al-LLZO and 15 wt% of SN achieved a high ionic conductivity of 4.17 × 10−4 Scm−1 at room temperature and a large value of 0.451 for the lithium-ion transport number at 60 °C. By adding 10 wt% SN and 10 wt% of Al-LLZO in the LiFePO4 cathode, the cell could operate at 25 °C with a specific capacity of 130 mAh g−1 and 89% capacity retention after 200 cycles at current density of 20 mA g−1. This study therefore proposes a solution to improve the ionic conductivity of solid polymer electrolytes in all-solid-state batteries.

The explosive growth of the social media community has increased many kinds of misinformation and is attracting tremendous attention from the research community. One of the most prevalent ways of misleading news is cheapfakes. Cheapfakes utilize non-AI techniques such as unaltered images with false context news to create false news, which makes it easy and “cheap” to create and leads to an abundant amount in the social media community. Moreover, the development of deep learning also opens and invents many domains relevant to news such as fake news detection, rumour detection, fact-checking, and verification of claimed images. Nevertheless, despite the impact on and harmfulness of cheapfakes for the social community and the real world, there is little research on detecting cheapfakes in the computer science domain. It is challenging to detect misused/false/out-of-context pairs of images and captions, even with human effort, because of the complex correlation between the attached image and the veracity of the caption content. Existing research focuses mostly on training and evaluating on given dataset, which makes the proposal limited in terms of categories, semantics and situations based on the characteristics of the dataset. In this paper, to address these issues, we aimed to leverage textual semantics understanding from the large corpus and integrated with different combinations of text-image matching and image captioning methods via ANN/Transformer boosting schema to classify a triple of (image, caption1, caption2) into OOC (out-of-context) and NOOC (no out-of-context) labels. We customized these combinations according to various exceptional cases that we observed during data analysis. We evaluate our approach using the dataset and evaluation metrics provided by the COSMOS baseline. Compared to other methods, including the baseline, our method achieves the highest Accuracy, Recall, and F1 scores.

Nanopores have a wide range of applications in the field of sensing. Here the authors report on synthetic nanopores made of DNA and designed for the transit of folded proteins across membranes to allow for biosensing.

All-solid-state batteries have gained significant attention as promising candidates to replace liquid electrolytes in lithium-ion batteries for high safety, energy storage performance, and stability under elevated temperature conditions. However, the low ionic conductivity and unsuitability of lithium metal in solid polymer electrolytes is a critical problem. To resolve this, we used a cubic garnet oxide electrolyte (Li7La3Zr2O12 – LLZO) and ionic liquid in combination with a polymer electrolyte to produce a composite electrolyte membrane. By applying a solid polymer electrolyte on symmetric stainless steel, the composite electrolyte membrane shows high ionic conductivity at elevated temperatures. The effect of LLZO in suppressing lithium dendrite growth within the composite electrolyte was confirmed through symmetric lithium stripping/plating tests under various current densities showing small polarization voltages. The full cell with lithium iron phosphate as the cathode active material achieved a highest specific capacity of 137.4 mAh g−1 and a high capacity retention of 98.47% after 100 cycles at a current density of 50 mA g−1 and a temperature of 60°C. Moreover, the specific discharge capacities were 137 and 100.8 mAh g−1 at current densities of 100 and 200 mA g−1, respectively. This research highlights the capability of solid polymer electrolytes to suppress the evolution of lithium dendrites and enhance the performance of all-solid-state batteries.

BACKGROUND:Chorioamnionitis has been linked to spontaneous preterm labor and complications such as neonatal sepsis. We hypothesized that microbial cell-free (cf) DNA would be detectable in maternal plasma in patients with chorioamnionitis and could be the basis for a non-invasive method to detect fetal exposure to microorganisms. OBJECTIVE:The purpose of this study was to determine whether next generation sequencing could detect microbial cfDNA in maternal plasma in patients with chorioamnionitis. STUDY DESIGN:Maternal plasma (n = 94) and umbilical cord plasma (n = 120) were collected during delivery at gestational age 28-41 weeks. cfDNA was extracted and sequenced. Umbilical cord plasma samples with evidence of contamination were excluded. The prevalence of microorganisms previously implicated in choriomanionitis, neonatal sepsis and intra-amniotic infections, as described in the literature, were examined to determine if there was enrichment of these microorganisms in this cohort. Specific microbial cfDNA associated with chorioamnionitis was first detected in umbilical cord plasma and confirmed in the matched maternal plasma samples (n = 77 matched pairs) among 14 cases of histologically confirmed chorioamnionitis and one case of clinical chorioamnionitis; 63 paired samples were used as controls. A correlation of rank of a given microorganism across maternal plasma and matched umbilical cord plasma was used to assess whether signals found in umbilical cord plasma were also present in maternal plasma. RESULTS:Microbial DNA sequences associated with clinical and/or histological chorioamnionitis were enriched in maternal plasma in cases with suspected chorioamnionitis when compared to controls (12/14 microorganisms, p = 0.02). Analysis of the microbial cfDNA in umbilical cord plasma among the 1,251 microorganisms detectable with this assay identified Streptococcus mitis, Ureaplasma spp., and Mycoplasma spp. in cases of suspected chorioamnionitis. This assay also detected cfDNA from Lactobacillus spp. in controls. Comparison between maternal plasma and umbilical cord plasma confirmed these signatures were also present in maternal plasma. Unbiased analysis of microorganisms with significantly correlated signal between matched maternal plasma and umbilical cord plasma identified the above listed 3 microorganisms, all of which have previously been implicated in patients with chorioamnionitis (Mycoplasma hominis p = 0.0001; Ureaplasma parvum p = 0.002; Streptococcus mitis p = 0.007). These data show that the pathogen signal relevant for chorioamnionitis can be identified in both maternal and umbilical cord plasma. CONCLUSION:This is the first report showing the detection of relevant microbial cell-free cfDNA in maternal plasma and umbilical cord plasma in patients with clinical and/or histological chorioamnionitis. These results may lead to the development of a specific assay to detect perinatal infections for targeted therapy to reduce early neonatal sepsis complications.

In this work, we show an effective ultrasonication-assisted self-assembly method under surfactant solution for a high-rate capable rGO-wrapped LiNi0.6Co0.2Mn0.2O2 (Ni-rich cathode material) composite. Ultrasonication indicates the pulverization of the aggregated bulk material into primary nanoparticles, which is effectively beneficial for synthesizing a homogeneous wrapped composite with rGO. The cathode composite demonstrates a high initial capacity of 196.5 mAh/g and a stable capacity retention of 83% after 100 cycles at a current density of 20 mA/g. The high-rate capability shows 195 and 140 mAh/g at a current density of 50 and 500 mA/g, respectively. The high-rate capable performance is attributed to the rapid lithium ion diffusivity, which is confirmed by calculating the transformation kinetics of the lithium ion by galvanostatic intermittent titration technique (GITT) measurement. The lithium ion diffusion rate (DLi) of the rGO-wrapped LiNi0.6Co0.2Mn0.2O2 composite is ca. 20 times higher than that of lithium metal plating on anode during the charge procedure, and this is demonstrated by the high interconnection of LiNi0.6Co0.2Mn0.2O2 and conductive rGO sheets in the composite. The unique transformation kinetics of the cathode composite presented in this study is an unprecedented verification example of a high-rate capable Ni-rich cathode material wrapped by highly conductive rGO sheets.

Perennial fruit crops generally and temperate fruits in particular make an important contribution to the sustainable development of the socio-economy in the northern mountainous region of Vietnam where the living standard of local farmers - 40% of whom are minorities from 30 groups - is still low (about 70% of the average of the country as a whole), though significant assistance has been made by the government and a slowly developed socio-economy has been recorded. It is obvious that proper temperate fruit production not only benefits local growers but also protects the environment in a significant way. Recent results concerning varietal selection and cultivation technologies for temperate fruits are summarized in this paper and some of the principal solutions, including proper planning, breeding programme enhancement, the establishing of production and value chains, and the training of skillful technicians and producers that is aimed at promoting production in the future, are also proposed.

In this paper we study the Peskin problem in two dimensions, which describes the dynamics of a one-dimensional closed elastic structure immersed in a steady Stokes flow. We prove the local well-posedness for arbitrary initial configuration in (C²)Ḃ¹ ∞,∞ satisfying the well-stretched condition, and the global well-posedness when the initial configuration is sufficiently close to an equilibrium in .æ. Here (C²)Ḃ¹ ∞,∞ is the closure of C² in the Besov space .æ. The global-in-time solution will converge to an equilibrium exponentially as t A Too. This is the first well-posedness result for the Peskin problem with non-Lipschitz initial data. [ABSTRACT FROM AUTHOR]

Magnetorheological (MR) dampers have been widely investigated and proposed for vibration mitigation systems because they possess continuous variability of damping coefficient in response to different operating conditions. In the conventional design of MR dampers, a separate controller and power supply are required, causing an increment of complexity and cost, which are not suitable for home appliances like washing machines. To solve these issues and to reuse wasted energy from vibration of washing machines, in this study, a self-powered shear-mode MR damper, which integrates MR damping and energy-harvesting technologies into a single device, is proposed. The MR damper is composed of an inner housing, on which magnetic coils are wound directly, and an outer housing for covering and creating a closed magnetic circuit of the damper. The gap between the inner housing and the moving shaft is filled with MR fluid to produce the damping force. The energy-harvesting part consists of permanent magnets fastened together on the shaft and induction coils wound directly on slots of the housing. The induced power from the induction coils is directly applied to the excitation coils of the damping part to generate a corresponding damping force against the vibration. In order to achieve optimal geometry of the self-powered MR damper, an optimization for both the damping part and the energy harvesting part of the proposed dampers are conducted based on ANSYS finite element analysis. From optimal solutions, a prototype of the proposed damper is designed in detail, manufactured, and experimentally validated.

This research focuses on the development of a new 3-DOF (Degree of Freedom) force feedback system featuring a spherical arm mechanism and three magnetorheological (MR) brakes, namely two rotary MR brakes and one linear MR brake. The first rotary MR brake is integrated in the waist joint to reflect the horizontal tangent force, the other rotary MR brake is integrated in the shoulder joint to reflect the elevation tangent force, while the linear MR brake is integrated in the sliding joint of the arm to reflect the radial force (approach force). The proposed configuration can reflect a desired force to the operator at the end-effectors of the arm independently in 3 DOFs by controlling the current applied to the coils of the MR brakes. After the introduction, the configuration of the proposed force feedback system is presented. Afterward, the design and conducted simulation of the MR brakes for the systems are provided. The prototype of the force feedback system, which was manufactured for the experiment, is then presented as well as some of the obtained experimental results. Finally, the proposed control system is presented and its implementation to provide a desired feedback force to the operator is provided.