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Multi-objective optimization of a solar assisted heat pump-driven by hybrid PV
摘要： The role of renewable energy sources becomes more and more important in modern times. Solar energy utilization in the building sector is one attractive solution for covering heating and electricity needs. In this direction, the investigation of a solar heating-electricity production system ideal for building applications is investigated in this study. This cogeneration system includes hybrid PV (or PV/T) collectors and a heat pump which is driven totally (heat and electricity) by the solar collector. The system is designed properly in order to produce net electricity production except for the need of the heat pump. This system is optimized using an innovative multi-objective procedure with heating and electricity production as the objective functions. The optimization is performed in steady-state conditions for seven different working fluids in the heat pumps. The optimum design points for all the working fluids are compared and finally, R32 is selected as the most suitable choice with R1234yf to be the second one. In the optimum design conditions, 10 m2 of hybrid PV collector are able to feed the heat pump and finally 4.33 kWth of heating and 0.53 kWel of net electricity to be produced. The next step in this study is the investigation of the system with R32 for all the winter period in the climate conditions of Athens (Greece). Six different typical days (one for every month from November to April) are examined and the final results are given. For January, which is a representative winter month, it is found that the daily heating and electricity production is 34.9 kWh and 5.13 kWh respectively. Moreover, the mean daily energy efficiency is found 60.53% while the exergy 9.26% for this month.
关键词： Working fluid investigation,Cogeneration,Space heating,Multi-objective optimization,PVT
更新于2025-09-23 15:23:52
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BEAUTIFUL FACES ENHANCE VERBAL WORKING MEMORY PERFORMANCE: AN NIRS STUDY
摘要： In addition to material rewards (such as money, food, and liquid), various social signals, including facial attractiveness, are perceived as incentives. Although material and monetary rewards are known to enhance various aspects of cognitive performance, it is not clear whether and how social signals affect cognition. The present study focused on facial attractiveness and investigated its effects on working memory. In addition, we used near-infrared spectroscopy (NIRS) to characterize the activation in the dorsolateral prefrontal cortex (DLPFC), an area known to be involved in the processing of reward-related cues in working memory. Our results show that compared to the non-reward condition, the cue for attractive faces enhanced working memory performance, but DLPFC activation did not differ between these two conditions. These results provide new evidence that facial attractiveness enhances verbal working memory performance and function via neural mechanisms different from those characterized for other types of rewarding cues.
关键词： DLPFC,attractive face,working memory,reward,NIRS
更新于2025-09-23 15:22:29
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Applications of Functional Near-Infrared Spectroscopy (fNIRS) Neuroimaging in Exercise–Cognition Science: A Systematic, Methodology-Focused Review
摘要： For cognitive processes to function well, it is essential that the brain is optimally supplied with oxygen and blood. In recent years, evidence has emerged suggesting that cerebral oxygenation and hemodynamics can be modified with physical activity. To better understand the relationship between cerebral oxygenation/hemodynamics, physical activity, and cognition, the application of state-of-the art neuroimaging tools is essential. Functional near-infrared spectroscopy (fNIRS) is such a neuroimaging tool especially suitable to investigate the effects of physical activity/exercises on cerebral oxygenation and hemodynamics due to its capability to quantify changes in the concentration of oxygenated hemoglobin (oxyHb) and deoxygenated hemoglobin (deoxyHb) non-invasively in the human brain. However, currently there is no clear standardized procedure regarding the application, data processing, and data analysis of fNIRS, and there is a large heterogeneity regarding how fNIRS is applied in the field of exercise–cognition science. Therefore, this review aims to summarize the current methodological knowledge about fNIRS application in studies measuring the cortical hemodynamic responses during cognitive testing (i) prior and after different physical activities interventions, and (ii) in cross-sectional studies accounting for the physical fitness level of their participants. Based on the review of the methodology of 35 as relevant considered publications, we outline recommendations for future fNIRS studies in the field of exercise–cognition science.
关键词： working memory,executive functions,cognition,physical activity,optical imaging,fNIRS
更新于2025-09-23 15:21:21
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Interface Engineering of CsPbBr <sub/>3</sub> Nanocrystal Light-Emitting Diodes via Atomic Layer Deposition
摘要： Perovskite nanocrystal (PNC) suffers from solution corrosion and water/oxygen oxidation when used in light-emitting diodes (LEDs). Atomic layer deposition (ALD) is applied to introduce Al2O3 infilling and interface engineering for the CsPbBr3 nanocrystal emission layers, and the inorganic electron transport layer-based CsPbBr3–ZnMgO LED device is fabricated. The introduction of Al2O3 ALD layers significantly improves the tolerance of CsPbBr3 PNC thin films to polar solvents ethanol of ZnMgO during spin coating. The operation lifetime of ALD-treated CsPbBr3 PNC–ZnMgO LED is prolonged to about two orders of magnitude greater than that of the CsPbBr3 PNC-TPBi LED device with a largely improved external quantum efficiency (EQE) value. Moreover, the infilling of Al2O3 into the CsPbBr3 layer boosts the carrier mobility for more than 40 times inside the light-emission layer. However, the interfacial carrier transport between different functional layers is hindered by the insulated Al2O3 layer, which provides an effective barrier for excess electron transport. Such a favorable band alignment facilitates the carrier balance of the device and contributes to the improved electroluminescent performance of the device with ALD Al2O3 interface engineering, which is further supported by theoretical device modeling. Herein, a facile method is provided to fabricate PNC-LED devices with both high efficiency and long-term lifetime.
关键词： light emitting diodes,working stability,interface engineering,atomic layer deposition,CsPbBr3 perovskite nanocrystals
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Evaluation of ultrasound reflection coefficient measurement result and its uncertainty by the method of linearization
摘要： It is shown that, if the ultrasound amplitudes before (A0) and after(A) application of the test liquid (soybean oil) to the working surface of the acoustic cell are measured using only one (working) channel of the installation, the measurement results become mutually correlated. And if A0 is measured on the reference installation channel and the amplitude A is measured on the working channel of the installation, the measurement results are not mutually correlated. And thus, it becomes possible to use the method of linearization to evaluate the measurement result and its accuracy characteristics (error and / or uncertainty).
关键词： error,uncertainty,ultrasound,acoustic cell,method of linearization,reference,liquid,measurement,working,correlation,reflection coefficient,soybean oil
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 9th International Conference on Consumer Electronics (ICCE-Berlin) - Berlin, Germany (2019.9.8-2019.9.11)] 2019 IEEE 9th International Conference on Consumer Electronics (ICCE-Berlin) - Case Study of Photovoltaic Energy Surplus Absorption by Charging Lithium-Ion Batteries Considering Chargea??Discharge Energy Efficiency
摘要： In Autumn 2018, reductive control of photovoltaic surplus energy was performed in Kyushu, Japan. This was a lost opportunity to utilize renewable energy, which could have been otherwise stored in rechargeable batteries. In this study, we simulated the absorption of the photovoltaic energy surplus by charging battery systems of a working electric vehicle considering the energy efficiency of lithium-ion battery systems to reduce the operation cost. This study clarified the quantitative effects of a real-time energy efficiency diagnosis of lithium-ion battery systems. From the simulation results, we discovered that the improvements of the charge–discharge energy loss and the economic gain of the photovoltaic energy surplus absorption depended on the input–output power of the bidirectional vehicle- to-grid charger and the amount of surplus energy. When the input–output power is sufficiently high and the ratio of surplus energy to total capacity of the battery systems is sufficiently low, is the reasonable. The real-time degradation diagnosis of the battery systems and selection considering charge–discharge energy efficiency is necessary to improve the profit from surplus energy absorption.
关键词： charge – discharge energy efficiency,Lithium-ion battery,degradation diagnosis,photovoltaic surplus energy,working electric vehicle
更新于2025-09-23 15:21:01
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Calibration method of 1D laser rangefinder for large-scale 3D measurement under harsh environment
摘要： Vision measurement has encountered the bottlenecks in capturing and processing the images of laser spots under harsh working environment of strong sunshine and complex background. Breaking through the camera calibration, we propose that the corresponding relationship between pixel coordinates of laser spots, but not the camera, and measurement distances generated from laser rangefinder is directly calibrated under good working environment. The pixel coordinates of laser spots can be obtained from the calibration model and measurement distances during practical measurement. The imaging of laser spots by camera is no longer needed. Experimental results demonstrate that the measurement errors are in the millimeter level within 20 m distance outdoors.
关键词： vision measurement,laser rangefinder,harsh working environment,calibration
更新于2025-09-23 15:21:01
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Characterization of Long Working Distance Optical Coherence Tomography for Imaging of Pediatric Retinal Pathology
摘要： Purpose: We determined the feasibility of fovea and optic nerve head imaging with a long working distance (LWD) swept source optical coherence tomography (OCT) prototype in adults, teenagers, and young children. Methods: A prototype swept source OCT system with a LWD (defined as distance from the last optical element of the imaging system to the eye) of 350 mm with custom fixation targets was developed to facilitate imaging of children. Imaging was performed in 49 participants from three age groups: 26 adults, 16 children 13 to 18 years old (teenagers), and seven children under 6 years old (young children) under an approved institutional review board protocol. The imaging goal was to acquire high quality scans of the fovea and optic nerve in each eye in the shortest time possible. OCT B-scans and volumes of the fovea and optic nerve head of each eligible eye were captured and graded based on four categories (lateral and axial centration, contrast, and resolution) and on ability to determine presence or absence of pathology. Results: LWD-OCT imaging was successful in 88 of 94 eligible eyes, including seven of 10 eyes of young children. Of the successfully acquired OCT images, 83% of B-scan and volumetric images, including 86% from young children, were graded as high-quality scans. Pathology was observed in high-quality OCT images. Conclusions: The prototype LWD-OCT system achieved high quality retinal imaging of adults, teenagers, and some young children with and without pathology with reasonable alignment time. Translational Relevance: The LWD-OCT system can facilitate imaging in children.
关键词： pediatric imaging,retinal imaging,long working distance,optical coherence tomography
更新于2025-09-23 15:21:01
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Processing and Study of Optical and Electrical Properties of (Mg, Al) Co-Doped ZnO Thin Films Prepared by RF Magnetron Sputtering for Photovoltaic Application
摘要： In this study, high transparent thin films were prepared by radio frequency (RF) magnetron sputtering from a conventional solid state target based on ZnO:MgO:Al2O3 (10:2 wt %) material. The films were deposited on glass and silicon substrates at the different working pressures of 0.21, 0.61, 0.83 and 1 Pa, 300 °C and 250 W of power. X-ray diffraction patterns (XRD), atomic force microscopy (AFM), UV-vis absorption and Hall effect measurements were used to evaluate the structural, optical, morphological and electrical properties of thin films as a function of the working pressure. The optical properties of the films, such as the refractive index, the extinction coefficient and the band gap energy were systematically studied. The optical band gap of thin films was estimated from the calculated absorption coefficient. That parameter, ranged from 3.921 to 3.655 eV, was hardly influenced by the working pressure. On the other hand, the lowest resistivity of 8.8 × 10?2 ? cm was achieved by the sample deposited at the lowest working pressure of 0.21 Pa. This film exhibited the best optoelectronic properties. All these data revealed that the prepared thin layers would offer a good capability to be used in photovoltaic applications.
关键词： working pressure,Al doped ZnO-MgO powder,RF magnetron sputtering,photovoltaic applications,thin films,solid-state method,optoelectronic properties
更新于2025-09-23 15:21:01
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Fabrication and characterization of metal oxide and lignocelluloses fibers based working electrode for dye-sensitized solar cells (DSSCs)
摘要： This study presents the fabrication of flexible composite sheets of titanium dioxide (TiO2) by incorporation of natural lignocelluloses fibers extracted from the self-growing plant, Typha Angustifolia to address the inherent rigid structure and superior absorption properties of the working electrode. Furthermore, fabricated TiO2 based composites were characterized by scanning electron microscope (SEM), Fourier transforms infrared (FTIR), ultraviolet-visible (UV-VIS) spectroscopy and employed as a working electrode for DSSC after deposition on fluorine doped tin oxide (FTO) glass substrate. SEM morphology reveals that LC fibers acted as a thread to bind the TiO2 nanoparticles and also with better voids for adsorption of electrolyte whereas FTIR spectroscopy confirms the successful formation of the paper composite. J-V measurements reveal the high efficiency of 2.95% for TiO2/LC flexible and environmentally safe composite which can be feasible for modern bendable DSSC.
关键词： Working Electrode,TiO2,Dye-Sensitized Solar Cell,lignocelluloses fibers
更新于2025-09-23 15:19:57