- 标题
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- 实验方案
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Rapid determination of mercury in dust emission using Cold Vapour Inductively Coupled Plasma Optical Emission Spectrometer (CV ICP OES)
摘要： Mercury emissions generated by the human activities were ranged between 60% and 90% from total mercury content determined in some industrialised regions. It is well known that urban dust has adverse health effects, being related to respiratory diseases. In this study, Cold Vapour Inductively Coupled Plasma Optical Emission Spectrometer (CV ICP OES) was optimised, validated, and applied in routine analysis for the determination of vapour mercury in dust emission samples collected from different Egyptian cement plants. The estimated detection limit, practical quantification limit, linearity (linear dynamic ranges and method linearity), accuracy (trueness and precision), and measurement uncertainty parameters were studied under optimised (CV ICP OES) conditions. The method showed that the estimated detection limit was found to be equal to 0.12 μg/L, and the quantification limit was found to be equal to 0.5 μg/L. The mean recoveries ± standard deviations at different levels were varied between 88.60 ± 8.18 and 110.20 ± 5.93% with a coefficient of variation expressed as relative standard deviation ranged from 0.64 and 7.25%. The method trueness was confirmed by using four different certified references materials purchased from Food Analysis Performance Assessment Scheme (FAPAS) and all obtained results were within satisfactory ranges and had acceptable recovery and Z-score values. The method precision, in terms of relative standard deviation (RSD), was being below 7.74%. The method uncertainty expressed as expanded uncertainty was found to be ≤ 16.11%. The results obtained make the method suitable for accurate determination of vapour mercury in dust emission samples at low concentration. The validated method was used for the determination of mercury in fifty-eight dust emissions samples and the results were compared with the maximum limit stated by European standard on the incineration of waste.
关键词： CV ICP OES,cement plants,mercury,Method validation,Egypt
更新于2025-09-19 17:13:59
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Determination of electrical characteristics and temperature of PV modules by means of a coupled electrical-thermal model
摘要： Photovoltaic (PV) modules are commonly tested under standard test conditions. However, the performance of the PV module is highly dependent on the location, climate condition, and sun spectrum. Simulation is one of the inexpensive and practical approaches to estimate the performance of PV modules under different climatic conditions. Modeling of PV modules can be complex because different physical phenomena must be coupled and interact with each other. There are several existing multi-physic models, but they are either complex such as numerical models or highly simpli?ed with a lot of assumptions. In this work, we introduce a thermal-electrical model to evaluate the performance of PV modules under different climate conditions based on a previously developed optical-electrical model. The model calculates the electrical parameters and temperature of the PV module after the module reaches the steady-state condition. The temperature, heat ?ow of all layers of the module, and the heat transfer thermal resistances can be determined. Comparison of the simulation and experimental results shows a deviation of around 1%, which indicates that the simulation and experimental results are in good agreement.
关键词： climate conditions,simulation,thermal-electrical model,experimental validation,Photovoltaic modules
更新于2025-09-19 17:13:59
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High-Performance Emulator for Fixed Photovoltaic Panels
摘要： This paper presents the design and implementation of a photovoltaic emulator, based on an accurate mathematical model of a photovoltaic panel, instead of the look-up table method. The latter requires more memory for increasing accuracy and considering all the desired environmental situations. Furthermore, the proposed approach takes into account the incidence solar angle, as an input parameter, to offer the possibility of evaluating daily losses for different values of tilt angle. The validation of the proposed emulator is carried out by comparing in real-time, both the studied panel output and the emulator output, under variable load, temperature, and irradiation levels. The emulator is able to operate online with connected solar radiation and temperature sensors or offline with recorded measurement vectors. The practical tests were performed on a prototype designed using a MATLAB C MEX S-function, dSPACE board 1104, and a controlled DC/DC converter. The results showed that the emulator was able to behave accurately as the studied photovoltaic panel.
关键词： DC/DC converter,mathematical model,real-time validation,incidence solar angle,photovoltaic emulator
更新于2025-09-19 17:13:59
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The effect of laser and ultrasound synchronization in photo-mediated ultrasound therapy
摘要： Fractional vegetation cover (FVC) is one of the most important criteria for surface vegetation status. This criterion corresponds to the complement of gap fraction unity at the nadir direction and accounts for the amount of horizontal vegetation distribution. This study aims to directly validate the accuracy of FVC products over crops at coarse resolutions (1 km) by employing ?eld measurements and high-resolution data. The study area was within an oasis in the Heihe Basin, Northwest China, where the Heihe Watershed Allied Telemetry Experimental Research was conducted. Reference FVC was generated through upscaling, which ?tted ?eld-measured data with spaceborne and airborne data to retrieve high-resolution FVC, and then high-resolution FVC was aggregated with a coarse scale. The fraction of green vegetation cover product (i.e., GEOV1 FVC) of SPOT/VEGETATION data taken during the GEOLAND2 project was compared with reference data. GEOV1 FVC was generally overestimated for crops in the study area compared with our estimates. Reference FVC exhibits a systematic uncertainty, and GEOV1 can overestimate FVC by up to 0.20. This ?nding indicates the necessity of reanalyzing and improving GEOV1 FVC over croplands.
关键词： fractional vegetation cover,Coarse resolution,product validation,SPOT/VEGETATION
更新于2025-09-19 17:13:59
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Chalcogenide Glass Fiber Components for the Fabrication of Mid-Infrared Optical Sources
摘要： The positioning of electromagnetic (EM) sources on the complex plane, though a mathematical construct, is often applied in solving EM problems with directive confined (collimated) propagation characteristics. Equivalent dipole modeling, which finds its application in characterizing various current sources can be computationally expensive for large structures. Here, the complex localization of equivalent source points combined with the particle swarm optimization is used to improve the performance of the equivalent dipole modeling.
关键词： Complex source point,edge dipoles,diffraction,particle swarm optimization,equivalent dipole model,feature selective validation
更新于2025-09-19 17:13:59
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Preheating and thermal behaviour of a rotating cylindrical workpiece in laser-assisted machining
摘要： Laser-assisted machining is a widely used technique for preheating workpiece to reduce cutting forces and promote machinability in metal machining, thereby enhancing manufacturing quality and productivity. In setting laser-assisted machining parameters, the current practice typically relies on trial-and-error approaches. The uncertainties thereof could lead to adverse outcomes in product manufacturing, thus negating the potential benefits of this machining method. A clear understanding of workpiece thermal behaviour under laser spot heating is pivotal to developing a systematic basis for determining required preheating levels and optimised cutting variables for laser-assisted machining. In achieving this, the experimental methods are recognised to be largely impractical, if not tedious, due to instrument limitations and practicality of suitable non-intrusive measuring methods. Conversely, numerical methodologies do provide precise, flexible and cost-effective analytical options, warranting potential for insightful understanding on the transient thermal impact from laser preheating on rotating workpiece. Presenting such an investigation, this article presents a finite volume-based numerical simulation that examines and analyses the thermal response imparted by laser spot preheating on a rotating cylinder surface. On a rotating frame of reference using the ANSYS Fluent solver, the numerical model is formulated, accounting for transient heat conduction into the cylinder body and the combined convection and radiation loses from the cylinder surface. The model is comprehensively validated to ascertaining its high predictive accuracy and the applicability under reported laser-assisted machining operating conditions. The extensive parametric analyses carried out deliver clear insight into the dynamics of thermal penetration occurring within the workpiece due to laser spot pre-heating. This facilitates appropriate consideration of laser preheating intensity in relation to other operating variables to achieve necessary material softening depth at the workpiece surface prior to setting out on the subsequent machining process. Building upon the data generated, a practically simpler and cost-effective preheating parametric predictor is synthesised for laser-assisted machining using neural network principles incorporating the Levenberg–Marquardt algorithm. This predictive tool is trained and verified as a practical preheating guide for laser-assisted machining for a range of operating conditions.
关键词： numerical thermal modelling,Laser-assisted machining,artificial neural network,validation,thermal treatment
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE Innovative Smart Grid Technologies - Asia (ISGT Asia) - Chengdu, China (2019.5.21-2019.5.24)] 2019 IEEE Innovative Smart Grid Technologies - Asia (ISGT Asia) - Review on modeling of photovoltaic power generation systems
摘要： In recent years, photovoltaic (PV) power generation has developed rapidly at China and abroad. PV power generation is on the trend from auxiliary power supply to main power supply even leading power supply. Due to the fluctuation and intermittent characteristics of PV power generation, and zero inertia, the integration of large-scale grid-connected PV power generation may have a negative impact on the stability of the power system. Modeling grid-connected PV power generation systems is the key factor to investigate the influence between it and other parts of power system. Modeling of PV is also a hot issue that has been studied continuously for many years around the world. GE, WECC, CIGRE, CEPRI and so on have attached great importance to this issue and have published many research results. The existing research at China and abroad is reviewed in this paper, the existing problems are analyzed, and suggestions for future research are given.
关键词： power plant,model validation,photovoltaic (PV) power generation,power unit,modeling
更新于2025-09-16 10:30:52
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Optimization of back ITO layer as the sandwiched reflector for exploiting longer wavelength lights in thin and flexible (30?μm) single junction c-Si solar cells
摘要： Fabrication of thin and ?exible crystalline silicon solar cells based on single junction concept is reported with detailed investigations on each step of the production ?ow chain. With the aim of minimizing material use/wastage as per the international technology roadmap for photovoltaic (ITRPV), which is also directly related to the device cost, e?orts have been made to introduce thin (~30 μm) c-Si wafers instead of a conventional 180 μm wafer to fabricate single-junction solar cells. Due to the introduction of thin (~30 μm) c-Si wafer, the device becomes ?exible, which is also an additional bene?t towards the development of future roll-to-roll electronics. In order to address better carrier collection in thin silicon as well as light management, measures have been taken by introducing an indium tin oxide (ITO) layer both on top and at the bottom. The in?uence of this ITO layer along with back Al contact toward the cell e?ciency has been discussed. X-ray di?raction (XRD) analysis has been carried out to investigate microstrain and dislocation density related changes in the thin wafer, which are known to have in?uence on the photoconversion e?ciency. Under 1 Sun illumination, current – voltage characteristics and external quantum e?ciency were measured and found to be promising.
关键词： Sandwiched back ITO layer,Theoretical validation,Single junction,Thin silicon solar cells,Monocrystalline Si
更新于2025-09-16 10:30:52
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Performance Assessment of ICESat-2 Laser Altimeter Data for Water-Level Measurement Over Lakes and Reservoirs in China
摘要： Although the Advanced Topographic Laser Altimeter System (ATLAS) onboard the Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2) was primarily designed for glacier and sea-ice measurement, it can also be applied to monitor lake surface height (LSH). However, its performance in monitoring lakes/reservoirs has rarely been assessed. Here, we report an accuracy evaluation of the ICESat-2 laser altimetry data over 30 reservoirs in China using gauge data. To show its characteristics in large-scale lake monitoring, we also applied an advanced radar altimeter SARAL (Satellite for ARgos and ALtika) and the first laser altimeter ICESat (Ice, Cloud and land Elevation Satellite) to investigate all lakes and reservoirs (>10 km2) in China. We found that the ICESat-2 has a greatly improved altimetric capability, and the relative altimetric error was 0.06 m, while the relative altimetric error was 0.25 m for SARAL. Compared with SARAL and ICESat data, the ICESat-2 data had the lowest measurement uncertainty (the standard deviation of along-track heights; 0.02 m vs. 0.07 m and 0.17 m), the greatest temporal frequency (3.43 vs. 1.35 and 1.48 times per year), and the second greatest lake coverage (636 vs. 814 and 311 lakes). The precise altimetric profiles derived from the ICESat-2 data indicate that most lakes (90% of 636 lakes) are quasi-horizontal (measurement uncertainty <0.05 m), and special methods are needed for mountainous lakes or shallow lakes to extract precise LSHs.
关键词： Water level,Validation,ICESat-2,ICESat,SARAL,Lake and reservoir
更新于2025-09-16 10:30:52
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Deep UV laser-induced fluorescence for pharmaceutical cleaning validation
摘要： Cleaning verification and validation is a requirement in the pharmaceutical industry. Due to the limited number of mobile devices that do effective and accurate onsite cleaning verification, it is mostly done via lab-based quality control techniques. These techniques, such as High-Performance Liquid Chromatography (HPLC) or Total Organic Carbon, often lead to extending the validation of cleaning by days. The void of more sensitive, accurate, and portable instruments to verify cleaning onsite has to be filled. The article discusses the use of Deep Ultra Violet (DUV) laser-induced fluorescence for detecting carryover of Active Pharmaceutical Ingredients (APIs) and detergents onsite. A modified spectrometer was used as an offsite bench type prototype for analyzing trace samples of API and cleaning detergents with various substrates. Even if the API to be detected has a low fluorescence efficiency, the specificity of the technique allows API traces having concentrations as low as ≈0.20 μg/cm2 to be identified. The work also shows the possibility of using a probe for validating cleaning of hard to reach areas using DUV laser-induced fluorescence. DUV laser-induced fluorescence of trace API over any polymer/glass substrate has better Signal to Background Ratio (SBR) compared to FTIR absorption techniques. Processing times of DUV laser-induced fluorescence trace detection are shown to be much less than swab based methods.
关键词： Active Pharmaceutical Ingredients (APIs),pharmaceutical cleaning validation,Deep Ultra Violet (DUV),signal to background ratio (SBR),laser-induced fluorescence
更新于2025-09-12 10:27:22