Power Enhancement Research Articles

EEG neural substrates of cognitive engagements for research-based learning with contemplative education in the young child

One becomes aware of the evidence of cognitive insights following attending the research-based learning program with contemplative education, electroencephalography (EEG), and electrodermal activity (EDA) were used to track the improvement of emotional and cognitive states. Research-based learning (RBL) and teaching models were developed to enhance research characteristics and cognitive training for children in the 21st century. To date, there have been no reliable cognitive tools to monitor the cognitive insight of the child who attends the course. The EEG, EDA, and cognitive scores of thirty healthy students participating in a research-based program for an hour per week were evaluated prior to the course, 3 months, and 6 months after the program started. The cognitive tests included a standard progressive matric (SPM) test, arithmetic test, Eriksen flanker task, and biofeedback sessions. The same procedures were determined in the comparative students’ group. After six months of taking the program, students in the RBL group showed a significant improvement in their SPM and arithmetic test scores. A significant increase in beta and gamma activity was detected in the temporal cortex of the RBL group during the SPM test. A more significant enhancement of frontal theta power was observed during the arithmetic test. This study shows that contemplative education and research-based learning improve cognitive abilities, indicating a significant increase in EEG quantity for cognitive engagement and the ability to confer individual differences in cognitive abilities.

Efficient and lightweight in-memory computing architecture for hardware security

This paper introduces an innovative solution for improving the efficiency and speed of the Advanced Encryption Standard (AES) based cryptographic algorithm. The approach leverages in-memory computing (IMC) and is versatile for application across a broad spectrum of IoT applications, including robotic autonomous vehicles and various other scenarios. To achieve this goal, memristor (MR) designs are proposed to emulate the arithmetic operations required for different phases of the AES algorithm, enabling efficient in-memory processing. The key contributions of this work include; 1) The development of a 4 bit-MR state element for implementing different arithmetic operations in an AES hardware prototype; 2) The creation of a pipeline AES design for massive parallelism and MR integration compatibility; and 3) The hardware implementation of the AES-IMC based architecture using the MR emulator. The results show that AES-IMC performs better than existing architectures in terms of higher throughput and energy efficiency. Compared to conventional AES hardware, AES-IMC achieves a 30% power enhancement with comparable throughput. Additionally, when compared to state-of-the-art AES-based NVM engines, AES-IMC demonstrates comparable power dissipation and a 62% increase in throughput. The IMC architecture enables cost-effective real-time deployment of AES, leading to high-performance computing. By leveraging the power of in-memory computing, this system is able to provide improved computational efficiency and faster processing speeds, making it a promising solution for a wide range of applications in the field of autonomous driving and robotics. The potential benefits of this system include improved safety and security of unmanned devices, as well as enhanced performance and cost-effectiveness in a variety of computing environments.

Influence of SiC and ZnO Doping on the Electrical Performance of Polylactic Acid-Based Triboelectric Nanogenerators.

Polylactic acid (PLA) is one of the most widely used materials for fused deposition modeling (FDM) 3D printing. It is a biodegradable thermoplastic polyester, derived from natural resources such as corn starch or sugarcane, with low environmental impact and good mechanical properties. One important feature of PLA is that its properties can be modulated by the inclusion of nanofillers. In this work, we investigate the influence of SiC and ZnO doping of PLA on the triboelectric performance of PLA-based tribogenerators. Our results show that the triboelectric signal in ZnO-doped PLA composites increases as the concentration of ZnO in PLA increases, with an enhancement in the output power of 741% when the ZnO concentration in PLA is 3 wt%. SiC-doped PLA behaves in a different manner. Initially the triboelectric signal increases, reaching a peak value with enhanced output power by 284% compared to undoped PLA, when the concentration of SiC in PLA is 1.5 wt%. As the concentration increases to 3 wt%, the triboelectric signal reduces significantly and is comparable to or less than that of the undoped PLA. Our results are consistent with recent data for PVDF doped with silicon carbide nanoparticles and are attributed to the reduction in the contact area between the triboelectric surfaces.

Hydrophobic and Luminescent Polydimethylsiloxane PDMS-Y2O3:Eu3+ Coating for Power Enhancement and UV Protection of Si Solar Cells.

Solar cells have been developed as a highly efficient source of alternative energy, collecting photons from sunlight and turning them into electricity. On the other hand, ultraviolet (UV) radiation has a substantial impact on solar cells by damaging their active layers and, as a result, lowering their efficiency. Potential solutions include the blocking of UV light (which can reduce the power output of solar cells) or converting UV photons into visible light using down-conversion optical materials. In this work, we propose a novel hydrophobic coating based on a polydimethylsiloxane (PDMS) layer with embedded red emitting Y2O3:Eu3+ (quantum yield = 78.3%) particles for UV radiation screening and conversion purposes. The favorable features of the PDMS-Y2O3:Eu3+ coating were examined using commercially available polycrystalline silicon solar cells, resulting in a notable increase in the power conversion efficiency (PCE) by ~9.23%. The chemical and UV stability of the developed coatings were assessed by exposing them to various chemical conditions and UV irradiation. It was found that the developed coating can endure tough environmental conditions, making it potentially useful as a UV-protective, water-repellent, and efficiency-enhancing coating for solar cells.

Power system resilience quantification and enhancement strategy for real-time operation

Power system resilience quantification and enhancement strategy for real-time operation

Investigation of cooling capability of ceramic substrates for power electronics applications

This study investigates the cooling capability of ceramic substrates, which are commonly used in power electronics. Ceramic substrates are pivotal in thermal management because they address the challenges posed by the concurrent trends of miniaturisation and power enhancement in power electronics. Therefore, a detailed numerical study of the cooling capabilities of Al2O3 and AlN substrates with various thicknesses from 0.05 mm to 3 mm in a model configuration with defined liquid cooling is conducted. This model configuration represents a commonly used stack-up for real power electronic modules. The results of the numerical study are verified through experimental measurements. It was demonstrated that for low substrate thicknesses (0.3–0.6 mm), similar cooling capabilities can be achieved by a combination of more efficiently cooling, less thermally conductive, and less expensive substrate. However, AlN is highly efficient for cooling in applications requiring substrates with thicknesses greater than 1.0 mm. The present study proved that increasing the thickness of the AlN substrate has a negligible effect on cooling efficiency. Based on the results of the numerical study, which is verified by experimental measurements, it is possible to design the optimal thickness of the ceramic substrate, flow rate of the cooling medium, and material of the ceramic substrate to achieve the required power dissipation from the substrate without exceeding the maximum defined operating temperature.

All‐Polarized Elastic Wave Attenuation and Harvesting via Chiral Mechanical Metamaterials

AbstractManipulating elastic waves of all polarizations is highly challenging due to the complex behavior of elastic waves. To achieve simultaneous broadband vibration attenuation and energy harvesting across all polarizations of elastic waves at low‐frequency ranges, a chiral mechanical metamaterial‐based energy harvester is proposed in this study. The systematic development of a complete bandgap and defect structure is achieved through theoretical eigenfrequency analysis and numerical simulations. The defect structure is incorporated to induce defect modes for all wave polarizations within the complete bandgap region, ensuring their compatibility with the overall shape of the structure. The proposed chiral mechanical metamaterial with defect (CMMD) demonstrated significant performance improvements, achieving electrical output power enhancements that are 20.5 times for flexural waves and 511.4 times for longitudinal‐torsional waves compared to the defectless chiral mechanical metamaterial. This study accentuates the thoughtful design and multifaceted utility of chiral mechanical metamaterials, paving the way for their application not only in energy harvesting but also in wave attenuation for various polarizations.

One-loop infrared rescattering by enhanced scalar fluctuations during inflation

We show that, whenever the perturbations of some field are excited during inflation by a physical process on sub-horizon scales, they unavoidably generate, even through gravitational interactions alone, a significant resonant IR cascade of power down to scales that are of the order of the horizon at that time (we denote these scales as near IR). We provide general analytic one-loop results for the enhancement of the IR power of the curvature perturbation generated by this effect, highlighting the role played by the resonance. We then study a number of examples in which the excited state is: (i) an isocurvature field, (ii) the curvature perturbation itself, (iii) a mixture of curvature and isocurvature fluctuations driven to an excited state by their coupled dynamics. In the cases shown, the cascade significantly modifies the near IR part of the power spectrum of the curvature perturbation with respect to the linear theory, indicating that this effect can impact the phenomenology associated with a variety of mechanisms considered in the literature, notably concerning primordial black holes and gravitational waves.

Terahertz power enhancement by combining photocurrent from arrayed UTC-PDs using Wilkinson power combiner

We designed a novel terahertz wave power combiner which combines HF currents from each photomixer in a micro strip line. The generator is composed of four uni-travelling carrier photodiodes (UTC-PDs) as the photomixers, a 4 × 1 Wilkinson power combiner and a microstrip rectangular patch antenna on a Silicon Carbide (SiC) substrate in which photocurrents of 300 GHz from the UTC-PDs are combined to be fed to the antenna. Experimental results show that the output power is multiplied by 11 dB (approximately 13 times) compared to that of a single UTC-PD. The combined power increases super-linearly with the number of the photomixers, confirms a great advantage of photomixing as a current source.

Reinforcement of executive power during the COVID -19 epidemic, a salient trend or temporary phenomenon related to pandemic control

The article is devoted to presenting the results of research on Polish legislation during the COVID-19 pandemic in terms of empowerment of public authority.The impact of the adopted laws on empowerment was assessed using an innovative research method based on the assumption that the creation of universally binding laws is based on long-term trends, and the law - like any other product - is driven by the law of supply and demand. The tendency for one or another legal intervention in social or economic relations can be seen in the periodic increase or decrease of legislative initiatives.We can talk about the strengthening of power when the adopted regulations serve the interests of public power, its better organization and strengthening of its potential. Most often, this is combined with the restriction of other authorities and the expansion of the interference of state power in social relations and citizens' rights.The article presents all the laws whose declared purpose was to combat the COVID-19 epidemic and its social and economic consequences and in which, in the process of evaluation, the occurrence of regulations strengthening public power was found (positive evaluation +1 and above).The graphs show how the adoption of power-enhancing and power-limiting regulations, respectively, has evolved since 1990, what this trend looked like in 2020, and finally how strong the power enhancement was in the so-called Covidovy laws.

The ubiquitous influence of image recognition in daily life

Image recognition technology has emerged due to the quick advancement of computer science. Using image recognition technology, a computer can identify and categorize diverse items in an image according to their functions. Artificial intelligence, image processing, and image recognition technology are all combined in this technology. The human eye and image recognition have a similar fundamental operating principle. The best outcomes can be achieved by taking out a few crucial elements from the image and contrasting them with the data that has been captured. This study describes how image recognition technology is used widely in modern life. It can improve people's lives if picture recognition is quick and precise. However, there are still many issues with picture recognition technology, such as security issues with gathering private information and loss of objectivity owing to algorithmic bias. Image recognition technology will become increasingly crucial in the connected world due to the ongoing development and enhancement of computer power. Image recognition technology will push what is technically possible in visual perception and artificial intelligence.

Sleep and local field potential effect of the D2 receptor agonist bromocriptine during the estrus cycle and postpartum period in female rats

BackgroundPituitary lactotrophs are under tonic dopaminergic inhibitory control and bromocriptine treatment blocks prolactin secretion. MethodsSleep and local field potential were addressed for 72 h after bromocriptine treatments applied during the different stages of the estrus cycle and for 24 h in the early- and middle postpartum period characterized by spontaneously different dynamics of prolactin release in female rats. ResultsSleep changes showed strong dependency on the estrus cycle phase of the drug application. Strongest increase of wakefulness and reduction of slow wave sleep- and rapid eye movements sleep appeared during diestrus-proestrus and middle postpartum treatments.Stronger sleep-wake effects appeared in the dark phase in case of the estrus cycle treatments, but in the light phase in postpartum treatments. Slow wave sleep and REM sleep loss in case of estrus cycle treatments was not compensated at all and sleep loss seen in the first day post-injection was gained further later. In opposition, slow wave sleep loss in the light phase after bromocriptine injections showed compensation in the postpartum period treatments.Bromocriptine treatments resulted in a depression of local field potential delta power during slow wave sleep while an enhancement in beta and gamma power during wakefulness regardless of the treatment timing. ConclusionsThese results can be explained by the interplay of dopamine D2 receptor agonism, lack of prolactin release and the spontaneous homeostatic sleep drive being altered in the different stages of the estrus cycle and the postpartum period.

Ionic liquid with hydrogen bonding reducing leakage charge for enhancing triboelectric performance

Refining the dielectric layer of a triboelectric nanogenerator (TENG) has been shown to maximize its output performance. Among the available strategies, utilizing an ionic dielectric can improve the output performance notably through the internal formation of an electrical double layer (EDL). However, ions dispersed in the ionic dielectric inevitably cause leakage charge between the surface charged layer and electrode of the ionic dielectric; this reduces the charge density, directly affecting output performance. Here, we investigate optimization of the ionic dielectric of a TENG using various ionic liquids (ILs), with the alkyl chain lengths of the cations and fluoride of anions with different size, to achieve power enhancement based on the EDL effect while concurrently suppressing leakage charge via hydrogen bonding. To elucidate the power enhancement working mechanisms within the ionic dielectric, we characterize the chemical, mechanical, and electrochemical properties of the ionic dielectric, including formation of hydrogen bonds, ionic conductivity, and dielectric constant. These parameters are investigated by varying the ion types, molecular sizes, and concentrations of the ILs within the ionic dielectric. As a results, our findings reveal that an IL of OMIM+PF6- dissolved in a base material of thermoplastic polyurethane (TPU) significantly enhances the voltage and current by 2.3 and 2.9 times, respectively, compared to those of a conventional TENG with TPU. These findings are expected to be implemented across a wide range of TENGs, paving the path for their advanced applications in next-generation energy harvesting.

박정희 정부의 전력증강 정책 추진에 대한 미국의 대응 분석

This article examines the response of the U.S. to the Korean government's power enhancement project in terms of alliance management. The Park Chung-hee administration resolved security concerns caused by increased threats from North Korea and the withdrawal of U.S. troops from Korea, and promoted a policy to increase power for self-defense. A dual-path strategy was implemented by the Park Chung-hee administration's power enhancement policy, which combined the conventional power enhancement policy and the nuclear weapons development policy. The U.S. showed double-faced strategy to the Korea’s power enhancement policy. First, the U.S. was in a favorable position to Korea’s conventional power enhancement policy. Second, the U.S. thwarted Korea’s nuclear weapons development by checking and obstructing it. Through this study, it can be confirmed that the success or failure of an attempt to change power through the power enhancement of a weaker country in an asymmetric alliance system depends on the interests of the powerful countries. Therefore, in order to resolve the imbalance in alliance relations through the increase of its own power, weaker countries must consider and persuade the interests of powerful countries.

Enhanced terahertz emission in a large-area photoconductive antenna through an array of tightly packed sapphire fibers

Experimental observation of the enhanced terahertz (THz) emission in a large-area photoconductive antenna-emitter (LAE), boosted by an array of cylindrical sapphire-fiber-based microlenses, is reported. The observed enhancement is achieved, thanks to the sharp focusing of a pump laser beam near the semiconductor surface, for which the high-refractive-index sapphire lenses are used. We predict numerically and confirm experimentally a considerable enhancement in the emitted THz spectral power for such a sapphire-fiber-coupled LAE, as compared to an ordinary one with an equal electrode topology. In fact, a ≃8.5-fold THz power boost is achieved, resulting in a +9.3 dB increase in the dynamic range. The results of our findings can be used to improve the performance of large-area THz devices, aimed at meeting the demands of rapidly developed THz spectroscopy, imaging, sensing, and exposure technologies.

Deficiency of Nuclear Receptor Coactivator 3 Aggravates Diabetic Kidney Disease by Impairing Podocyte Autophagy.

Nuclear receptors (NRs) are important transcriptional factors that mediate autophagy, preventing podocyte injury and the progression of diabetic kidney disease (DKD). However, the role of nuclear receptor coactivators that are powerful enhancers for the transcriptional activity of NRs in DKD remains unclear. In this study, a significant decrease in Nuclear Receptor Coactivator 3 (NCOA3) is observed in injured podocytes caused by high glucose treatment. Additionally, NCOA3 overexpression counteracts podocyte damage by improving autophagy. Further, Src family member, Fyn is identified to be the target of NCOA3 that mediates the podocyte autophagy process. Mechanistically, NCOA3 regulates the transcription of Fyn in a nuclear receptor, PPAR-γ dependent way. Podocyte-specific NCOA3 knockout aggravates albuminuria, glomerular sclerosis, podocyte injury, and autophagy in DKD mice. However, the Fyn inhibitor, AZD0530, rescues podocyte injury of NCOA3 knockout DKD mice. Renal NCOA3 overexpression with lentivirus can ameliorate podocyte damage and improve podocyte autophagy in DKD mice. Taken together, the findings highlight a novel target, NCOA3, that protects podocytes from high glucose injury by maintaining autophagy.

Site-specific wake steering strategy for combined power enhancement and fatigue mitigation within wind farms

Wind energy plays a crucial role in the quest for sustainable energy solutions. However, optimizing the efficiency of wind energy utilization remains a significant challenge. Wake steering, a key strategy in the field, offers the potential to address this challenge. This study introduces an innovative site-specific wake steering framework that incorporates a wake superposition model for wake steering, a machine-learning based fatigue and power predictor and a multi-objective optimizer to both enhance total power generation and mitigate fatigue loads within wind farms. The wake superposition model, developed and validated here, successfully replicates secondary wake steering effects and provides a new solution for calculating superimposed transverse velocity. The study comprehensively considers and implements constraints based on physical laws. Analysis of inflow speed and turbulence levels reveals that wake steering can continue to enhance total power output. Power enhancement can reach up to 18% at lower turbulence levels and still achieve significant increases even when inflow speeds exceed rated values, with only marginal increases in fatigue loads. Lower turbulence levels improve optimization results at the expense of heightened structural loads, while higher turbulence levels lead to diminishing power enhancement and additional fatigue loads. Examination of wind turbine spacing shows that smaller intervals yield substantial power enhancement, with improvements of up to 51.7%, although the effect diminishes as intervals increase and wake recovery takes place. In conclusion, the proposed site-specific wake steering framework offers an efficient means of balancing enhanced wind farm power output and structural integrity, representing a significant advancement in wind energy optimization.

Design of 2DOF control system fused with artificial intelligence for power enhancement and mitigation of degradation in fuel cell systems

The commercialization of Fuel Cell Systems (FCSs) faces a key obstacle in the form of limited cell lifespan and resultant cell degradation. This paper introduces a new approach, leveraging an artificial intelligence-based 2DOF control system to regulate the Oxygen Excess Ratio (OER) with two main goals: mitigating cell degradation due to oxygen starvation and optimizing net power output. The proposed control system incorporates a data-driven feedforward controller in conjunction with a feedback controller, facilitating the tracking of desired OER values generated by a data-driven reference generator. We develop fuzzy models and neural networks as the reference generator and feedforward controller to capture the complex FCS behavior by processing the stack current w/wo the temperature of FCS (i.e. Single input or Double input models). By exploring the effects of the structural settings of the models, this study provides a comprehensive understanding of their impact on the representation performance of the FCS characteristics. Although the fitting performances of all models are quite satisfactory, their actual performance gain is evaluated on a realistic FCS model at various operation points. The findings and comparative analysis emphasize the efficacy of incorporating stack temperature in fuzzy-model-based 2DOF control systems, showcasing their potential to maximize net power output through enhanced OER control loop performance while also extending the lifespan of FCSs, as confirmed by results from a developed degradation model.

Motor oscillations reveal new correlates of error processing in the human brain

It has been demonstrated that during motor responses, the activation of the motor cortical regions emerges in close association with the activation of the medial frontal cortex implicated with performance monitoring and cognitive control. The present study explored the oscillatory neurodynamics of response-related potentials during correct and error responses to test the hypothesis that such continuous communication would modify the characteristics of motor potentials during performance errors. Electroencephalogram (EEG) was recorded at 64 electrodes in a four-choice reaction task and response-related potentials (RRPs) of correct and error responses were analysed. Oscillatory RRP components at extended motor areas were analysed in the theta (3.5–7 Hz) and delta (1–3 Hz) frequency bands with respect to power, temporal synchronization (phase-locking factor, PLF), and spatial synchronization (phase-locking value, PLV). Major results demonstrated that motor oscillations differed between correct and error responses. Error-related changes (1) were frequency-specific, engaging delta and theta frequency bands, (2) emerged already before response production, and (3) had specific regional topographies at posterior sensorimotor and anterior (premotor and medial frontal) areas. Specifically, the connectedness of motor and sensorimotor areas contra-lateral to the response supported by delta networks was substantially reduced during errors. Also, there was an error-related suppression of the phase stability of delta and theta oscillations at these areas. This synchronization reduction was accompanied by increased temporal synchronization of motor theta oscillations at bi-lateral premotor regions and by two distinctive error-related effects at medial frontal regions: (1) a focused fronto-central enhancement of theta power and (2) a separable enhancement of the temporal synchronization of delta oscillations with a localized medial frontal focus. Together, these observations indicate that the electrophysiological signatures of performance errors are not limited to the medial frontal signals, but they also involve the dynamics of oscillatory motor networks at extended cortical regions generating the movement. Also, they provide a more detailed picture of the medial frontal processes activated in relation to error processing.

Wells turbine power enhancement by simultaneous and opposite motion of the turbine-chamber system

Wells turbine power enhancement by simultaneous and opposite motion of the turbine-chamber system