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[IEEE 2018 IEEE 3rd International Conference on Signal and Image Processing (ICSIP) - Shenzhen, China (2018.7.13-2018.7.15)] 2018 IEEE 3rd International Conference on Signal and Image Processing (ICSIP) - Analysis of Linear FM Signal Based on the STFT in the Filtering Viewpoint
摘要： Analyzing signal with STFT transformation is not able to achieve a fine resolution in both the time and frequency due to the restriction of the Heisenberg–Gabor inequality. However, little has been studied about the STFT in the filtering viewpoint, such as the influence of the length of the filter impulse response. This paper mainly studies the frequency estimation of linear frequency modulated (LFM) signal with the STFT in the filtering viewpoint. The length of the filter impulse response is observed in its impact on the variation of time-frequency distribution (TFD). Based on a series of experiments, it is proved that the longer impulse response does not always guarantee the better concentration in the TFD. To obtain the best TFD for the LFM signal processing, an optimal impulse response length needs to be determined beforehand.
关键词： filtering viewpoint,frequency modulation parameters,impulse response
更新于2025-09-23 15:23:52
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Facile synthesis of two-dimensional tailored graphitic carbon nitride with enhanced photoelectrochemical properties through a three-step polycondensation method for photocatalysis and photoelectrochemical immunosensor
摘要： Graphitic carbon nitride (g-C3N4) is an ideal alternative two-dimensional (2D) nanostructure for photocatalysis and photoelectrochemical (PEC) application, while controllably fabricating 2D shaped g-C3N4 nanolayers/nanosheets is still facing challenges. On the basis of temperature-dependent polymorphic characters, herein, a 2D extending g-C3N4 (g-CNS3) is synthesized from dicyandiamide as the precursor by operating the condensation temperature in a continuously three-step thermal polycondensation procedure. The g-CNS3 with film-like morphology showed improved visible-light absorption ability and enhanced PEC performance compared to g-CNS1 synthesized via the traditional one-step thermal polymerization method. Benefiting from its excellent PEC properties, the g-CNS3 exhibited high photocatalytic activity to removal MB with fast kinetics and served as the photoactive layer to construct a PEC immunosensor with high sensitivity and specificity for subgroup J avian leukosis virus detection. A linear range from 102.14 to 103.35 TCID50/mL and a detection limit of 102.08 TCID50/mL were obtained for the PEC immunoassay of the target virus. This work might provide a novel protocol for tailoring shaped 2D g-C3N4 nanosemiconductor with superior properties and shed light on its promising PEC applications.
关键词： Two-dimensional material,Photocurrent response,Graphitic carbon nitride,Photocatalysis,Photoelectrochemical immunosensor
更新于2025-09-23 15:23:52
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A coumarin-based colorimetric fluorescent probe for rapid response and highly sensitive detection of hydrogen sulfide in living cells
摘要： Hydrogen sulfide (H2S) plays a vital role in numerous biological processes in living organisms. To better understand its functions, a fluorescent probe to fast and sensitively detect H2S is imminently needed. Keep this in mind, we reasonably designed probe DHC for detecting H2S based on α, β-unsaturated ethanoylcoumarin fluorophore. The limit of detection (LOD) is found to be as low as 5 × 10?8 M, which is superior to most reported fluorescent probes to detect H2S. Furthermore, the wide pH range of 4–11 makes it capable of application in biological systems. Most importantly, MTT assays and cell imaging experiments indicate that probe DHC has hypotoxicity and outstanding membrane permeability, which makes DHC successful imaging of H2S in Baby Hamster Syrian Kidney (BHK) cells.
关键词： Cell-imaging,Fluorescent probe,Rapid response,H2S,Coumarin
更新于2025-09-23 15:23:52
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Adsorption and photodegradation efficiency of TiO2/Fe2O3/PAC and TiO2/Fe2O3/zeolite nanophotocatalysts for the removal of cyanide
摘要： The synthesized TiO2/Fe2O3 nanostructures supported on powder activated carbon (PAC) and zeolite at different mole ratios of Fe3+/TiO2 were characterized by XRD, XRF, FESEM, EDX, TEM, FTIR, BET and, PL analyses and their cyanide photodegradation mechanism was thoroughly discussed. The results confirmed not only TiO2/Fe2O3/PAC had higher photocatalytic and adsorption capability but also better structural stability and reusability for cyanide removal than TiO2/Fe2O3/zeolite. The first order kinetics model indicated that the photodegradation rate using TiO2/Fe2O3/PAC was 1.3 times higher than that of TiO2/Fe2O3/zeolite. The response surface methodology (RSM) assessment showed that pH, irradiation time and initial cyanide concentration using UV/H2O2/TiO2/Fe2O3/zeolite system had more effects on the degradation respectively; whereas the effectiveness of UV/H2O2/TiO2/Fe2O3/PAC process was highly influenced by initial cyanide concentration than the other two parameters. High R2 and well-fitted residual plots approved the accuracy of the models in predicting the cyanide degradation efficiency using both the photocatalysts.
关键词： and adsorption comparison,Cyanide,Response surface methodology (RSM),TiO2/Fe2O3/zeolite and TiO2/Fe2O3/PAC photocatalysts,Photodegradation,Kinetic
更新于2025-09-23 15:23:52
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Heterobimetallic (Fe <sup>II</sup> /Pt <sup>II</sup> )-Based Supramolecular Coordination Complexes Using 1,1′-Ferrocene Dicarboxylate: Self-Assembly and Interaction with Carbon Dots
摘要： The synthesis and characterization of a new pyrazine-based ditopic organoplatinum(II) complex having a bite angle of 180° is reported. The facile and efficient syntheses are described of three discrete neutral Fe(II)/Pt(II) heterobimetallic SCCs with Pt(II) acceptor clips of different binding angles, 0, 120, and 180°. These new SCCs were characterized by multinuclear NMR and mass spectrometry. Electrochemical response of these ferrocene containing self-assembled ensembles was studied using cyclic voltammetry. The diplatinum acceptor organometallic clips significantly quench the fluorescence of highly emitting carbon quantum dots (CD), while the self-assembled macrocycles tend to nullify the quenching effect of the organometallic clips. Interestingly, the inefficient quenching of CD fluorescence by these SCCs was found to be directly related to the angular disposition of the binding sites in the Pt(II) based organometallic clips.
关键词： carbon dots,heterobimetallic,electrochemical response,self-assembly,supramolecular coordination complexes,fluorescence quenching,ferrocene
更新于2025-09-23 15:23:52
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Smart Energy Optimization Using Heuristic Algorithm in Smart Grid with Integration of Solar Energy Sources
摘要： Smart grid (SG) vision has come to incorporate various communication technologies, which facilitate residential users to adopt different scheduling schemes in order to manage energy usage with reduced carbon emission. In this work, we have proposed a residential load management mechanism with the incorporation of energy resources (RESs) i.e., solar energy. For this purpose, a real-time electricity price (RTP), energy demand, user preferences and renewable energy parameters are taken as an inputs and genetic algorithm (GA) has been used to manage and schedule residential load with the objective of cost, user discomfort, and peak-to-average ratio (PAR) reduction. Initially, RTP is used to reduce the energy consumption cost. However, to minimize the cost along with reducing the peaks, a combined pricing model, i.e., RTP with inclining block rate (IBR) has been used which incorporates user preferences and RES to optimally schedule load demand. User comfort and cost reduction are contradictory objectives, and difficult to maximize, simultaneously. Considering this trade-off, a combined pricing scheme is modelled in such a way that users are given priority to achieve their objective as per their requirements. To validate and analyze the performance of the proposed algorithm, we first propose mathematical models of all utilized loads, and then multi-objective optimization problem has been formulated. Furthermore, analytical results regarding the objective function and the associated constraints have also been provided to validate simulation results. Simulation results demonstrate a significant reduction in the energy cost along with the achievement of both grid stability in terms of reduced peak and high comfort.
关键词： inclining block rate,real-time pricing,renewable energy sources,appliances scheduling,demand response,genetic algorithm,demand side management
更新于2025-09-23 15:23:52
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Photocatalytic degradation of yellow 2G dye using titanium dioxide/ultraviolet A light through a Box–Behnken experimental design: Optimization and kinetic study
摘要： Yellow 2G (Y2G), a type of anionic, synthetic monoazo dye that is widely used in household applications, textiles, and food industries, has been found to have cardiovascular and neurological effects on all living beings. In the present study, heterogeneous photocatalytic degradation of commercial Y2G was conducted using pure titanium dioxide (TiO2) in a batch reactor system under ultraviolet A (UVA) light for 180 min. TiO2 dosage, pH, and initial Y2G concentration were the three experimental parameters selected and studied to obtain preliminary information about the photocatalytic activities within a specified range. The Box–Behnken design method (BBD) was used to determine optimal values of the results using the above parameters of Y2G photocatalysis under response surface methodology (RSM). The optimum conditions were 0.914 g L?1 TiO2, pH 3.45, and an initial Y2G concentration of 20 mg L?1. The Y2G degradation efficiency was 96.19% using a second-order polynomial equation with R2 = 0.999. The experimental results also showed that the photocatalytic process could be successfully explained using the modified Langmuir–Hinshelwood model, where kc and KLH were 0.787 mg L?1 min and 0.010 L mg?1, respectively.
关键词： photocatalysis,Box–Behnken design (BBD),optimization,Yellow 2G (Y2G) dye,response surface methodology (RSM)
更新于2025-09-23 15:23:52
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Fiber Bragg grating-based experimental and numerical investigations of CO <sub/>2</sub> migration front in saturated sandstone under subcritical and supercritical conditions
摘要： Carbon dioxide (CO2) can be at risk of leakage during its storage in deep saline aquifers due to stress field changes in the reservoir. The aim of this study was to investigate the effects of CO2 injection pressure on dynamic strain response of the reservoir and the CO2 migration process. A series of core flooding experiments was performed with the-state-of-art fiber Bragg grating sensors. The results show that the surface strain response was linearly correlated with CO2 injection pressure. Carbon dioxide migration velocity can be estimated from the strain response time differences among three gratings. The migration velocity of supercritical CO2 is higher than that of liquid CO2 but lower than gaseous CO2. Finally, numerical simulation was applied to model the CO2 migration process and the simulated values were compatible with those of experiments.
关键词： reservoir sandstone,core flooding,CO2 geological storage,CO2 migration front,fiber Bragg grating,strain response
更新于2025-09-23 15:23:52
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Sol-gel assisted nano-structured SnO<sub>2</sub> sensor for low concentration ammonia detection at room temperature
摘要： Sol-gel assisted nano-structured SnO2 sensor for low concentration ammonia detection at room temperature. Upon exposure to 500 ppb and 1 ppm of NH3, sensor manifests appreciable response ~ 28 % and ~ 31.5 %, respectively. High response of the sensor at RT is attributed due to porous nanograins (with average particle size ~ 50 nm) based SnO2 thin film layer. Nanograins structure is obtained due to addition of glycerine in the sol solution, which also leads to porosity enhancement of the sensing layer. Good reproducibility and appreciable immunity to drift behavior are other attributes of the fabricated device. High response and good selectivity towards ammonia are observed with very fast response and recovery time at RT, for extreme low concentrations level ~ 55 % RH for concentration range 500 ppb-500 ppm. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and scanning electron microscopy (SEM) results are used to study the structural, chemical composition, topography and morphological characteristics of the prepared SnO2 thin film, respectively.
关键词： Sol-gel,Room temperature,Ammonia sensor,Metal oxides,% Response,Nanostructured
更新于2025-09-23 15:23:52
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Parametric Study and Optimization of Linear and Nonlinear Vibration Absorbers Combined with Piezoelectric Energy Harvester
摘要： In this work, a harmonically excited generalized two degree of freedom non-linear system is used to manifest the functions of both the vibration absorber and energy harvester simultaneously. The generalized system has been reduced to a linear primary system with linear/nonlinear absorber and harvester or nonlinear primary system with linear/nonlinear absorber and harvester. Multi-harmonic balance method (MHBM) along with arc length continuation is used for generating frequency response plots for different absorber and energy harvester system parameters with constant primary system parameters and excitation amplitude. The frequency response plots show multiple branches of stable periodic solutions and jump at certain frequency ranges for systems with nonlinearity. The absorber and energy harvester parameters are optimized using an optimization procedure based on genetic algorithm in combination with response surface methodology. The method is validated with analytical solutions available in the literature for a linear primary system with linear absorber and harvester and nonlinear primary system with nonlinear absorber alone. This study demonstrates that the proposed optimization framework along with MHBM is suitable for generating the optimal frequency response for multifunctional energy harvesting systems or systems with nonlinear absorber. The frequency response plots with optimal parameter values reiterates the fact that the absorber system with nonlinear element perform better compared to its linear counterpart over a wider band of frequencies. The study also reports the comparison of the performance of a combined nonlinear absorber harvester system with that of a nonlinear energy sink (NES) absorber harvester system.
关键词： vibration absorber,multi-harmonic balancing,energy harvesting,optimization,response surface method,genetic algorithm
更新于2025-09-23 15:23:52