- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2017 14th IEEE India Council International Conference (INDICON) - Roorkee, India (2017.12.15-2017.12.17)] 2017 14th IEEE India Council International Conference (INDICON) - Power Management In Solar PV Fed Microgrid System With Battery Support
摘要： Installation of renewable resources at single phase residential premises calls on for the need of power management and coordination control of operating system. System is divided components which includes, solar PV maximum power point tracking (MPPT) via boost converter, bi-directional DC-DC converter for battery charging applications, and bidirectional AC-DC converter for feeding AC loads, etc.,. This paper, the solar PV alongside with battery power elaborates management scenario so as to form a sophisticated residential consumer system capable of operating in both grid forming (or, islanded) and feeding (or, grid connected) modes. System is tested via PSCAD based simulation platform, for operation in varying operating modes such that the power could be fed from DC to AC microgrid and vice-versa. DC-AC converter operating in closed loop sine pulse width modulation (SPWM) scheme, is used to control AC side voltage while operating in islanded mode. It works in rectification mode during grid connected mode. In day time, system is in islanded mode where excess / deficit power is exchanged with energy storage unit (ESU). In evening or night time, it operates in grid connected mode so as to charge the ESU.
关键词： Converter control,power management,grid forming,energy storage unit,microgrid,grid feeding
更新于2025-09-11 14:15:04
-
[Micro/Nano Technologies] Micro and Nano Fabrication Technology Volume 1 || Fabrication of Metallic Nanodot Arrays
摘要： Metal nanodot arrays exhibit unique optical characteristics, and they are expected to find widespread applications in biosensors and various optical devices. In this section, simple and efficient manufacturing processes are introduced for metal nanodot arrays. These processes are based on the combination of thin metal film coatings deposited on substrates and thermal dewetting. The first process discussed herein is a conventional thermal dewetting method. With this method, it is shown that the average dot diameter can be controlled based on the chosen process conditions. The second process is based on the use of grid patterning on coated metal films. This process can allow fabrication of nanodot arrays with uniform dot diameters and achieve highly ordered alignment of dots. The third process generates a metal nanodot array based on a self-organization manner on a nanogrid-patterned substrate. It constitutes a high-productivity process based on the transfer of the metal nanodot array to an adhesive film. The basic mechanisms underlying these processes are discussed herein.
关键词： Productivity,Metal coating,Dot transfer,Surface energy,Metal nanoparticles,Agglomeration,Nano plastic forming,Optical characteristics,Grid patterning,Self-organization,Biosensors,Thermal dewetting
更新于2025-09-10 09:29:36
-
[IEEE 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Trebic, Czech Republic (2018.9.18-2018.9.20)] 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Public Lighting, Public Health
摘要： Impact of artificial light at night on sleep and health of humans and other living species is discussed among scientists. This paper analyses the properties of several commercially available light sources with regards to their effects on wildlife, human sleep, and health. A novel, environmentally considerate LED light source is introduced. Further, integration of this light source into the pilot biodynamic street lighting system is described. Based on the season and time of day, a control system changes the spectral composition of the light in lighting without compromising on safety, psychological needs or energy savings.
关键词： advanced control system,spectral power distribution,light at night,LED,biodynamic lighting,non-image forming light perception,Circadian rhythm
更新于2025-09-10 09:29:36
-
Influence of the ceramic powder morphology and forming conditions on the optical transmittance of YAG:Yb ceramics
摘要： The influence of the dispersity and morphology of ceramic powders on the characteristics of green bodies and the optical transmittance of YAG:Yb (20 at.%) ceramics was considered. The effect of the specific surface area on the relative density of compacts was studied. An increase in the specific surface area from 1.45 to 12.38 m2/g led to a decrease in the relative density of green body compacts from 52 to 38% under the fixed uniaxial pressure of 50 MPa. An increase in the uniaxial pressing value up to 150 MPa provided a maximum increase of the optical transmission of ceramics. However, an increase in the specific surface area and uniaxial pressure led to the appearance of macrodefects in ceramic samples. Cold isostatic pressing at 200 MPa after uniaxial pressing at 50 MPa resulted in an increase of optical transparency and the elimination of the macrodefect formation in ceramics. Dispersity and morphology of ceramic powders have a significant effect on the optical transparency of ceramics. Forming conditions had insignificant influence on optical characteristics. Highly transparent YAG:Yb ceramics with 80% transmittance were developed.
关键词： specific surface area,highly transparent YAG:Yb ceramics,agglomeration coefficient,forming,cold isostatic pressing
更新于2025-09-10 09:29:36
-
Photochemical generation of radicals from alkyl electrophiles using a nucleophilic organic catalyst
摘要： Chemists extensively use free radical reactivity for applications in organic synthesis, materials science, and life science. Traditionally, generating radicals requires strategies that exploit the bond dissociation energy or the redox properties of the precursors. Here, we disclose a photochemical catalytic approach that harnesses different physical properties of the substrate to form carbon radicals. We use a nucleophilic dithiocarbamate anion catalyst, adorned with a well-tailored chromophoric unit, to activate alkyl electrophiles via an SN2 pathway. The resulting photon-absorbing intermediate affords radicals upon homolytic cleavage induced by visible light. This catalytic SN2-based strategy, which exploits a fundamental mechanistic process of ionic chemistry, grants access to open-shell intermediates from a variety of substrates that would be incompatible with or inert to classical radical-generating strategies. We also describe how the method’s mild reaction conditions and high functional group tolerance could be advantageous for developing C–C bond-forming reactions, for streamlining the preparation of a marketed drug, for the late-stage elaboration of biorelevant compounds and for enantioselective radical catalysis.
关键词： radicals,SN2 pathway,alkyl electrophiles,photochemical,C–C bond-forming reactions,visible light,enantioselective radical catalysis,nucleophilic organic catalyst
更新于2025-09-10 09:29:36
-
Light modulates oscillatory alpha activity in the occipital cortex of totally visually blind individuals with intact non-image-forming photoreception
摘要： The discovery of intrinsically photosensitive retinal ganglion cells (ipRGCs) marked a major shift in our understanding of how light information is processed by the mammalian brain. These ipRGCs influence multiple functions not directly related to image formation such as circadian resetting and entrainment, pupil constriction, enhancement of alertness, as well as the modulation of cognition. More recently, it was demonstrated that ipRGCs may also contribute to basic visual functions. The impact of ipRGCs on visual function, independently of image forming photoreceptors, remains difficult to isolate, however, particularly in humans. We previously showed that exposure to intense monochromatic blue light (465 nm) induced non-conscious light perception in a forced choice task in three rare totally visually blind individuals without detectable rod and cone function, but who retained non-image-forming responses to light, very likely via ipRGCs. The neural foundation of such light perception in the absence of conscious vision is unknown, however. In this study, we characterized the brain activity of these three participants using electroencephalography (EEG), and demonstrate that unconsciously perceived light triggers an early and reliable transient desynchronization (i.e. decreased power) of the alpha EEG rhythm (8–14 Hz) over the occipital cortex. These results provide compelling insight into how ipRGC may contribute to transient changes in ongoing brain activity. They suggest that occipital alpha rhythm synchrony, which is typically linked to the visual system, is modulated by ipRGCs photoreception; a process that may contribute to the non-conscious light perception in those blind individuals.
关键词： non-image-forming photoreception,alpha EEG rhythm,ipRGCs,blind individuals,occipital cortex
更新于2025-09-10 09:29:36
-
Performance Analysis of Fractional Fourier Domain Beam-Forming Methods for Sensor Arrays
摘要： The problem of estimating the direction of arrival (DoA) of multiple far-field moving targets, producing broad-banded chirp signals, in both active and passive mode of operation is addressed. As the chirp signal, commonly used in both radar and sonar systems is better processed in fractional Fourier domain, the detection is done using fractional Fourier transform (FrFT) in the proposed work. Subsequently, the DoA estimation is achieved using both conventional and subspace methods. Even though FrFT beamforming method has been studied in the past, its performance in respect of varying signal-to-noise ratios (SNRs) and multiple target detection has not been extensively analyzed yet. The results of simulation experiments reported in the present work show that FrFT enjoys better estimation accuracy over the conventional frequency domain beam-forming for chirp signals using Fourier transform (FT), in terms of computational efficiency, accuracy and resolution with low SNR, limited snapshots and sensors, and spatially coherent/multi-path signals. The performance metrics used for the study are (i) root mean square error, (ii) 3-dB beam width and (iii) CPU time for accuracy, resolution and computation time, respectively. It is seen from computer simulations that MUSIC outperforms other DoA estimation techniques from the performance curves for both active and passive systems.
关键词： direction of arrival estimation,chirp signal,Sensor arrays,beam-forming,fractional Fourier transform
更新于2025-09-09 09:28:46
-
[IEEE 2018 Conference on Emerging Devices and Smart Systems (ICEDSS) - Tiruchengode, India (2018.3.2-2018.3.3)] 2018 Conference on Emerging Devices and Smart Systems (ICEDSS) - Poor Quality Underwater Image Enhancement for Aqua Farming using Hybrid WCID
摘要： Enhancement of underwater is more complicated when compared with normal images due to color scatter and cast. Haze effects create significant impact on image contrast and visibility. Underwater environment has more smudge due to light attenuation. Under these circumstances capturing the clear pictures of fish and prawn for health monitoring is very difficult. Conventional enhancement algorithms fail to provide better solution for poor quality underwater images. To overcome these difficulties this paper presents a hybrid approach that includes image dehazing along with wavelength compensation (WCID). Several realistic aqua images were considered in this paper to prove the novelty of the proposed hybrid WCID based underwater image enhancement.
关键词： Wavelength compensation,Aqua Forming,Dehazing,Color scatter and cast
更新于2025-09-09 09:28:46
-
Pore forming channels as a drug delivery system for photodynamic therapy in cancer associated with nanoscintillators
摘要： According to the World Health Organization (WHO), cancer is one of main causes of death worldwide, with 8.2 million people dying from this disease in 2012. Because of this, new forms of treatments or improvement of current treatments are crucial. In this regard, Photodynamic therapy (PDT) has been used to successfully treat cancers that can be easily accessed externally or by fibre-optic endoscopes, such as skin, bladder and esophagus cancers. In addition, this therapy can used alongside radiotherapy and chemotherapy in order to kill cancer cells. The main problem in implementing PDT is penetration of visible light deeper than 10 mm in tissues, due to scattering and absorption by tissue chromophores. Unfortunately, this excludes several internal organs affected by cancer. Another issue in this regard is the use of a selective cancer cell-photosensitizing compound. Nevertheless, several groups have recently developed scintillation nanoparticles, which can be stimulated by X-rays, thereby making this a possible solution for light production in deeper tissues. Alternative approaches have also been developed, such as photosensitizer structure modifications and cell membrane permeabilizing agents. In this context, certain channels lead to transitory plasma membrane permeability changes, such as pannexin, connexin hemmichannels, TRPV1-4 and P2X7, which allow for the non-selective passage of molecules up to 1,000 Da. Herein, we discuss the particular case of the P2X7 receptor-associated pore as a drug delivery system for hydrophilic substances to be applied in PDT, which could also be carried out with other channels. Methylene blue (MB) is a low cost dye used as a prototype photosensitizer, approved for clinical use in several other clinical conditions, as well as photodynamic therapy for fungi infections.
关键词： PDT,pore forming channels,nanoscintillators,drug delivery,cancer
更新于2025-09-09 09:28:46
-
A SIMPLE 2×3 BEAM-FORMING NETWORK WITH A 2-BIT PHASE SHIFTER FOR FOUR-BEAM RECONFIGURATION
摘要： A simple 2×3 recon?gurable beam-forming network (R-BFN) for four-beam recon?guration application is designed and implemented. The proposed R-BFN with two input ports and three output ports consists of a 2:1 power divider, a 90? hybrid, a 180? hybrid and a 2-bit phase shifter. The 2-bit phase shifter has two states: one is a 180? phase shifter (State 1); the other is a 0?/360? phase shifter (State 2). By introducing the 2-bit phase shifter, the constant phase di?erences of three output ports can be recon?gured. When the proposed R-BFN is connected to an antenna array, a four-beam recon?guration is obtained. Simulated and measured results show that good impedance matching, high port isolation, equal power division, and constant phase di?erence have been achieved simultaneously within the operation band of 2.4–2.6 GHz. The capability of the proposed R-BFN to recon?gure beams is also veri?ed experimentally by using a 2.5 GHz dipole array.
关键词： antenna array,phase shifter,recon?guration,beam-forming network
更新于2025-09-09 09:28:46