After-Fatigue Condition: A Novel Analysis Based on Surface EMG Signals

This study introduces a novel muscle activation analysis based on surface electromyography (sEMG) signals to assess the muscle's after-fatigue condition. Previous studies have mainly focused on the before-fatigue and fatigue conditions. However, a comprehensive analysis of the after-fatigue condition has been overlooked. The proposed method analyzes muscle fatigue indicators at various maximal voluntary contraction (MVC) levels to compare the before-fatigue, fatigue, and after-fatigue conditions using amplitude-based, spectral-based, and muscle fiber conduction velocity (CV) parameters. In addition, the contraction time of each MVC level is also analyzed with the same indicators. The results show that in the after-fatigue condition, the muscle activation changes significantly in the ways such as higher CV, power spectral density shifting to the right, and longer contraction time until exhaustion compared to the before-fatigue and fatigue conditions. The results can provide a comprehensive and objective evaluation of muscle fatigue and recovery, which can be helpful in clinical diagnosis, rehabilitation, and sports performance

Physical security with power beacon assisted in half-duplex relaying networks over Rayleigh fading channel: performance analysis

In this research, we proposed and investigated physical security with power beacon assisted in half-duplex relaying networks over a Rayleigh fading channel. In this model, the source (S) node communicates with the destination (D) node via the helping of the intermediate relay (R) node. The D and R nodes harvest energy from the power beacon (PB) node in the presence of a passive eavesdropper (E) node. Then we derived the integral form of the system outage probability (OP) and closed form of the intercept probability (IP). The correctness of the analytical of the OP and IP is verified by the Monte Carlo simulation. The influence of the main system parameters on the OP and IP also is investigated. The research results indicated that the analytical results are the same as the simulation ones

Energy harvesting-based spectrum access with incremental cooperation, relay selection and hardware noises

In this paper, we propose an energy harvesting (EH)-based spectrum access model in cognitive radio (CR) network. In the proposed scheme, one of available secondary transmitters (STs) helps a primary transmitter (PT) forward primary signals to a primary receiver (PR). Via the cooperation, the selected ST finds opportunities to access licensed bands to transmit secondary signals to its intended secondary receiver (SR). Secondary users are assumed to be mobile, hence, optimization of energy consumption for these users is interested. The EH STs have to harvest energy from the PT's radio-frequency (RF) signals to serve the PTPR communication as well as to transmit their signals. The proposed scheme employs incremental relaying technique in which the PR only requires the assistance from the STs when the transmission between PT and PR is not successful. Moreover, we also investigate impact of hardware impairments on performance of the primary and secondary networks. For performance evaluation, we derive exact and lower-bound expressions of outage probability (OP) over Rayleigh fading channel. Monte-Carlo simulations are performed to verify the theoretical results. The results present that the outage performance of both networks can be enhanced by increasing the number of the ST-SR pairs. In addition, the outage performance of both primary and secondary networks is severely degraded with the increasing of hardware impairment level. It is also shown that fraction of time used for EH and positions of the secondary users significantly impact on the system performance.Web of Science26125024

Chemical composition and antibacterial activities of essential oils from Homalomena pierreana (Araceae)

30-37Homalomena is a genus of the Araceae family which contains several remedies used extensively in traditional Vietnamese medicine. H. pierreana is a rare plant species of Homalomena genus and found only in Phu Quoc National Park, Phu Quoc Island, Kien Giang Province, Vietnam. Therefore, the number of studies about this species is limited and the bioactivity of this species is still unknown. In this study, the chemical composition of essential oils was investigated which was isolated from leaves and rhizomes of H. pierreana at the first time by GC-MS. Eight and twelve compounds were identified from the essential oils of rhizomes and leaves, respectively. The major component from both the rhizomes and the leaves was aromadendrene (44 and 48%, respectively). Furthermore, the antibacterial activity of essential oils collected from leaves and rhizomes of H. pierreana was investigated and it was observed that the essential oil of rhizomes could inhibit the growth of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, while the essential oil of leaves exhibited an inhibitory effect against Staphylococcus aureus and Escherichia coli.</em

Chemical composition and antibacterial activities of essential oils from Homalomena pierreana (Araceae)

Homalomena is a genus of the Araceae family which contains several remedies used extensively in traditional Vietnamese medicine. H. pierreana is a rare plant species of Homalomena genus and found only in Phu Quoc National Park, Phu Quoc Island, Kien Giang Province, Vietnam. Therefore, the number of studies about this species is limited and the bioactivity of this species is still unknown. In this study, the chemical composition of essential oils was investigated which was isolated from leaves and rhizomes of H. pierreana at the first time by GC-MS. Eight and twelve compounds were identified from the essential oils of rhizomes and leaves, respectively. The major component from both the rhizomes and the leaves was aromadendrene (44 and 48%, respectively). Furthermore, the antibacterial activity of essential oils collected from leaves and rhizomes of H. pierreana was investigated and it was observed that the essential oil of rhizomes could inhibit the growth of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, while the essential oil of leaves exhibited an inhibitory effect against Staphylococcus aureus and Escherichia coli

The Non-Parametric Approaches For Time-Varying Delay Estimation With Application To The Electromyography Signals

International audienc

Do the generalized correlation methods improve time-delay estimation for muscle conduction fiber velocity?

International audienc

Time-Varying Delay Estimation Applied to the Surface Electromyography Signals Using the Parametric Approach

International audienc

High active and coke-resistant CeNiO3-based catalyst for methane bi-reforming

In this study, Ce1-xLaxNiO3 catalysts (x = 0.2, 0.4, 0.6, and 0.8) and Ce1-xLaxNiO3 on porous silica were prepared by co-precipitation. The effect of the La content on the catalytic activity in methane bi-reforming was investigated in the temperature range of 550 °C-750 °C. The physicochemical properties of the prepared catalysts were analysed by several methods, including X-ray diffraction, hydrogen temperature-programmed reduction, CO2 temperature-programmed desorption, N2 adsorption isotherm, energy-dispersive X-ray spectroscopy, Raman spectroscopy, scanning electron microscopy and high-resolution transmission electron microscopy. From the research results, the suitable substitution rate of La in Ce1-xLaxNiO3 was found to be x = 0.4; its conversions of CH4 of 94% and CO2 of 92% were achieved at 700 °C and GHSV 30000 mL/(g.h). However, the intense coke accumulation on Ce0.6La0.4NiO3 limited its development. The porous silica carrier improved the structure and properties of the Ce0.6La0.4NiO3 catalyst. The SiO2-supported catalyst (Ce0.6La0.4NiO3/SiO2) showed excellent stability and coke resistance, which had stable activity for 100 h of time on stream, structure stability and low coke accumulation; 2.37 mgC/gcat formed after 100 h (coke formation rate of 0.02 mmolC/(gcat.h)), which demonstrated that it was one of the best coke-resistant perovskite catalysts for the BRM reaction. The large surface area of silica and strong interaction of Ni with metal oxide reduced the metal Ni particle size to the threshold size (2−4 nm), where the strongly reduced coke accumulation, high basicity, and vacancy oxygen content of CeO2 and La2O3 were considered major contributors to the high activity and exceptional coke resistance. The high structural stability, anti-sintering performance and high coke resistance all contributed to the excellent durability of the Ce0.6La0.4NiO3/SiO2 catalyst. This work provides a new resolution for the development of coke-resistant perovskite catalysts for methane reforming