Review of battery storage and power electronic systems in flexible A-R-OPF frameworks. - In: Electronics, ISSN 2079-9292, Bd. 12 (2023), 14, 3127, S. 1-15
This paper provides an overview of power electronics and its applications in various fields, emphasizing power conditioning and minimizing losses for high energy efficiency. It discusses the distinction between unidirectional and bidirectional converters and their applications in power systems. The significance of unidirectional and bidirectional power flow in different scenarios is explored. The importance of battery storage systems (BSSs) for grid stabilization, frequency regulation, and renewable energy integration is highlighted. The paper focuses on flexible active-reactive optimal power flow (A-R-OPF) frameworks in battery storage and power electronic systems, reviewing existing research, identifying gaps, and offering new perspectives. It addresses the challenges and potential of grid-scale energy storage for reliable and cost-effective power systems with high renewable energy penetration. The need for energy curtailment, demand response, and smart grid implementation is discussed. The paper emphasizes comprehensive coordination, new power lines, European collaboration, and smart grid implementation to meet the dynamic needs of Europe’s power grids.
https://doi.org/10.3390/electronics12143127
Geometric feature extraction in manufacturing based on a knowledge graph. - In: Heliyon, ISSN 2405-8440, Bd. 9 (2023), 9, e19694, S. 1-15
In times of global crises, the resilience of production chains is becoming increasingly important. If a supply chain is interrupted, a cost-effective solution must be established quickly. In the context of Industry 4.0, the concept of smart manufacturing offers a solution for fast and automated decision-making in production planning. The core idea of smart manufacturing is the digitalization of the product life cycle and the linking of individual phases of this cycle. Computer Aided Process Planning (CAPP) plays an important role as the connecting element between design and manufacturing. An important prerequisite for CAPP is the automated analysis of 3D models of components. The aim of this work is the development of an automatic feature recognition (AFR) -method to recognize geometric manufacturing features and their properties from 3D-models and then store them in a knowledge base. In that way, the result of the design can be automatically analysed and compared with manufacturing information afterwards in order to achieve an automated process planning. Geometric and topological information of a 3D model (STEP-AP242 format) generated by CAD systems is extracted by a Python-script developed and stored in an ontology-based knowledge base. The extracted product data is analysed using a Python-script to identify manufacturing features. To provide a comprehensive extensibility of the model, geometric features are defined according to a layered and hierarchical structure.
https://doi.org/10.1016/j.heliyon.2023.e19694
The effect of C60 fullerene on the mechanokinetics of muscle gastrocnemius contraction in chronically alcoholized rats. - In: Heliyon, ISSN 2405-8440, Bd. 9 (2023), 8, e18745, S. 1-10
The C60 fullerene effect (oral administration at a dose of 1 mg kg−1) on the selected biomechanical parameters of muscle gastrocnemius contraction, biochemical indicators of blood and muscle tissue as well as histological changes in rat muscle tissue after chronic alcoholization for 3, 6 and 9 months was studied in detail. Water-soluble C60 fullerenes were shown to reduce the pathological processes development in the muscle apparatus by an average of (35-40)%. In particular, they reduced the time occurrence of fatigue processes in muscle during the long-term development of alcoholic myopathy and inhibited oxidative processes in muscle, thereby preventing its degradation. These findings open up the possibility of using C60 fullerenes as potent antioxidants for the correction of the pathological conditions of the muscle system arising from alcohol intoxication.
https://doi.org/10.1016/j.heliyon.2023.e18745
Suppressing the intrinsic photoelectric response of organic semiconductors for highly-photostable organic transistors. - In: Small, ISSN 1613-6829, Bd. 19 (2023), 50, 2304634, S. 1-8
Suppressing the photoelectric response of organic semiconductors (OSs) is of great significance for improving the operational stability of organic field-effect transistors (OFETs) in light environments, but it is quite challenging because of the great difficulty in precisely modulating exciton dynamics. In this work, photostable OFETs are demonstrated by designing the micro-structure of OSs and introducing an electrical double layer at the OS/polyelectrolyte dielectric interface, in which multiple exciton dynamic processes can be modulated. The generation and dissociation of excitons are depressed due to the small light-absorption area of the microstripe structure and the excellent crystallinity of OSs. At the same time, a highly efficient exciton quenching process is activated by the electrical double layer at the OS/polyelectrolyte dielectric interface. As a result, the OFETs show outstanding tolerance to the light irradiation of up to 306 mW&hahog;cm−2, which far surpasses the solar irradiance value in the atmosphere (≈138 mW&hahog;cm−2) and achieves the highest photostability ever reported in the literature. The findings promise a general and practicable strategy for the realization of photostable OFETs and organic circuits.
https://doi.org/10.1002/smll.202304634
Why temporal inference stimulation may fail in the human brain: a pilot research study. - In: Biomedicines, ISSN 2227-9059, Bd. 11 (2023), 7, 1813, S. 1-25
Temporal interference stimulation (TIS) aims at targeting deep brain areas during transcranial electrical alternating current stimulation (tACS) by generating interference fields at depth. Although its modulatory effects have been demonstrated in animal and human models and stimulation studies, direct experimental evidence is lacking for its utility in humans (in vivo). Herein, we directly test and compare three different structures: firstly, we perform peripheral nerve and muscle stimulation quantifying muscle twitches as readout, secondly, we stimulate peri-orbitally with phosphene perception as a surrogate marker, and thirdly, we attempt to modulate the mean power of alpha oscillations in the occipital area as measured with electroencephalography (EEG). We found strong evidence for stimulation efficacy on the modulated frequency in the PNS, but we found no evidence for its utility in the CNS. Possible reasons for failing to activate CNS targets could be comparatively higher activation thresholds here or inhibitory stimulation components to the carrier frequency interfering with the effects of the modulated signal.
https://doi.org/10.3390/biomedicines11071813
Human-sized quantitative imaging of magnetic nanoparticles with nonlinear magnetorelaxometry. - In: Physics in medicine and biology, ISSN 1361-6560, Bd. 68 (2023), 15, 155002, S. 1-10
Objective. Magnetorelaxomety imaging (MRXI) is a noninvasive imaging technique for quantitative detection of magnetic nanoparticles (MNPs). The qualitative and quantitative knowledge of the MNP distribution inside the body is a prerequisite for a number of arising biomedical applications, such as magnetic drug targeting and magnetic hyperthermia therapy. It was shown throughout numerous studies that MRXI is able to successfully localize and quantify MNP ensembles in volumes up to the size of a human head. However, deeper regions that lie far from the excitation coils and the magnetic sensors are harder to reconstruct due to the weaker signals from the MNPs in these areas. On the one hand, stronger magnetic fields need to be applied to produce measurable signals from such MNP distributions to further upscale MRXI, on the other hand, this invalidates the assumption of a linear relation between applied magnetic field and particle magnetization in the current MRXI forward model which is required for the imaging procedure. Approach. We tackle this problem by introducing a nonlinear MRXI forward model that is also valid for strong magnetic excitation fields. Main results. We demonstrate in our experimental feasibility study that scaling up the imaging region to the size of a human torso using nonlinear MRXI is possible. Despite the extreme simplicity of the imaging setup applied in this study, an immobilized MNP sample with 6.3 cm3 and 12 mg Fe could be localized and quantified with an acceptable quality. Significance. A well-engineered MRXI setup could provide much better imaging qualities in shorter data acquisition times, making nonlinear MRXI a viable option for the supervision of MNP related therapies in all regions of the human body, specifically magnetic hyperthermia.
https://doi.org/10.1088/1361-6560/ace304
Water-soluble pristine C60 fullerenes attenuate isometric muscle force reduction in a rat acute inflammatory pain model. - In: BMC musculoskeletal disorders, ISSN 1471-2474, Bd. 24 (2023), 606, S. 1-8
Background: Being a scavenger of free radicals, C60 fullerenes can influence on the physiological processes in skeletal muscles, however, the effect of such carbon nanoparticles on muscle contractility under acute muscle inflammation remains unclear. Thus, the aim of the study was to reveal the effect of the C60 fullerene aqueous solution (C60FAS) on the muscle contractile properties under acute inflammatory pain. Methods: To induce inflammation a 2.5% formalin solution was injected into the rat triceps surae (TS) muscle. High-frequency electrical stimulation has been used to induce tetanic muscle contraction. A linear motor under servo-control with embedded semi-conductor strain gauge resistors was used to measure the muscle tension. Results: In response to formalin administration, the strength of TS muscle contractions in untreated animals was recorded at 23% of control values, whereas the muscle tension in the C60FAS-treated rats reached 48%. Thus, the treated muscle could generate 2-fold more muscle strength than the muscle in untreated rats. Conclusions: The attenuation of muscle contraction force reduction caused by preliminary injection of C60FAS is presumably associated with a decrease in the concentration of free radicals in the inflamed muscle tissue, which leads to a decrease in the intensity of nociceptive information transmission from the inflamed muscle to the CNS and thereby promotes the improvement of the functional state of the skeletal muscle.
https://doi.org/10.1186/s12891-023-06719-w
Positioning of pivot points in quadrupedal locomotion: limbs global dynamics in four different dog breeds. - In: Frontiers in Bioengineering and Biotechnology, ISSN 2296-4185, Bd. 11 (2023), 1193177, S. 1-16
Dogs (Canis familiaris) prefer the walk at lower speeds and the more economical trot at speeds ranging from 0.5 Fr up to 3 Fr. Important works have helped to understand these gaits at the levels of the center of mass, joint mechanics, and muscular control. However, less is known about the global dynamics for limbs and if these are gait or breed-specific. For walk and trot, we analyzed dogs’ global dynamics, based on motion capture and single leg kinetic data, recorded from treadmill locomotion of French Bulldog (N = 4), Whippet (N = 5), Malinois (N = 4), and Beagle (N = 5). Dogs’ pelvic and thoracic axial leg functions combined compliance with leg lengthening. Thoracic limbs were stiffer than the pelvic limbs and absorbed energy in the scapulothoracic joint. Dogs’ ground reaction forces (GRF) formed two virtual pivot points (VPP) during walk and trot each. One emerged for the thoracic (fore) limbs (VPPTL) and is roughly located above and caudally to the scapulothoracic joint. The second is located roughly above and cranially to the hip joint (VPPPL). The positions of VPPs and the patterns of the limbs’ axial and tangential projections of the GRF were gaits but not always breeds-related. When they existed, breed-related changes were mainly exposed by the French Bulldog. During trot, positions of the VPPs tended to be closer to the hip joint or the scapulothoracic joint, and variability between and within breeds lessened compared to walk. In some dogs, VPPPL was located below the pelvis during trot. Further analyses revealed that leg length and not breed may better explain differences in the vertical position of VPPTL or the horizontal position of VPPPL. The vertical position of VPPPL was only influenced by gait, while the horizontal position of VPPTL was not breed or gait-related. Accordingly, torque profiles in the scapulothoracic joint were likely between breeds while hip torque profiles were size-related. In dogs, gait and leg length are likely the main VPPs positions’ predictors. Thus, variations of VPP positions may follow a reduction of limb work. Stability issues need to be addressed in further studies.
https://www.frontiersin.org/articles/10.3389/fbioe.2023.1193177
Bimetallic-based composites for potassium-ion storage: challenges and perspectives. - In: Inorganic chemistry frontiers, ISSN 2052-1553, Bd. 10 (2023), 16, S. 4668-4694
Potassium ion batteries (PIBs) are important for the development of energy storage systems as an effective complement to lithium ion batteries (LIBs) owing to the abundance of potassium resources in the earth's crust to meet the needs of large-scale energy storage systems. To this end, numerous studies have focused on anode materials, which can provide high capacity for PIBs. Bimetallic-based compounds (ABXs) achieve higher capacity and structural diversity due to their different chemical compositions and rich spatial structures. Moreover, the synergistic effect of the two metals makes the structure of ABXs more stable. Hence, ABXs are one of the most promising anode materials. This review focuses on performance optimization strategies (such as metal base selection, structural design, voltage regulation, and electrolyte optimization) and the electrochemical properties of ABXs. Finally, the current challenges and research prospectives of ABXs are presented. This review is expected to provide new perspectives and deeper insights into the study of ABXs as anode materials for PIBs and large-scale energy storage devices.
https://doi.org/10.1039/D3QI00585B
Ultrathin metal Ni layer on ZnO/TiO2 photoelectrodes with excellent photoeletrochemical performance in multiple electrolyte solutions. - In: Fuel, ISSN 1873-7153, Bd. 351 (2023), 128774
It is well known that the oxygen vacancy (Ovac) as the electron-donor dopant in semiconductor can increase the electron-holes separation in photoeletrochemical (PEC) water splitting. Furthermore, the metal Ni can promote the hydrogen evolution reaction (HER) on the surface of semiconductor. In this paper, the ZnO/TiO2 photoelectrodes with rich Ovac was synthesized by electrostatic adsorption through using ZIF-8 as the precursor. Then the ultrathin Ni layer with about 7 nm was deposited on the surface of ZnO/TiO2 (Ni/ZnO/TiO2) by vacuum thermal evaporation method. The Ni/ZnO/TiO2 photoelectrodes showed the highest photocurrent than ZnO/TiO2, Ni/ TiO2 and pure TiO2 photoelectrodes. The durability of Ni/ZnO/TiO2 photoelectrodes was keeping for 10 h in multiple electrolyte solutions under AM 1.5 G illumination and the photocurrent decline can be ignored. The UV-vis absorption spectra demonstrated that the ultrathin Ni layer showed plasma with ZnO/TiO2 for enhancing the water splitting performance. Furthermore, the ultrathin Ni layer enhanced the photogenerated charges transfer for improving the PEC performance. This work provides a new method for ultrathin metal Ni layer with Ovac semiconductor photoelectrode to improve the PEC performance in multiple electrolyte solutions.
https://doi.org/10.1016/j.fuel.2023.128774