17 research outputs found
Reliable Colour Detection for Matching Repaint Application
This paper presents the design and development of a system that creates the optimal conditions to sense colour for matching repaint application. The effectiveness of eliminating, and then recreating the lighting conditions to a desired level in a controlled enclosure is explored. The desired artificial light is introduced into the enclosure, providing optimal, constant conditions to measure surface reflectance. The tests conducted showed that the proposed system worked well. The testing results were good and showed that the relative results between samples taken at exactly the same location were an accurate match and consistent.fals
Enhancement of Wind Energy Conversion Using Axial Flux Generator
This paper investigates the application of the axial flux machine (AFM) to the wind energy conversion systems (WECS) to obtain high power and torque at reduced cost. By developing mathematical equations using the phase and active transformations, the three-phase model is transformed to two-phase equations by making both the stator and rotor as reference frames, finally converting to arbitrary reference frame, which is useful for the modelling of the axial flux machine. The torque, current, and voltage equations are expressed to improve the simulation reliability. Based on the developed equations, the mathematical model for the axial flux machine is developed using the MATLAB/Simulink. Starting with the axial flux motor model, when the load on the motor increases, how the parameters like torque, current, and speed of the motor vary are explored in this paper. Then for the axial flux generator model, when the wind speed exceeds the rated speed how the torque, line voltages, currents, power and speed of the generator behave are investigated and presented in this paper. The developed model in this paper could be extended to a twin-rotor axial flux synchronous machine, which will lead to the development of more efficient WECS.fals
Simulation of Switched Reluctance Generator in Low and Medium Speed Operations for Wind Energy Application
This paper provides a new approach to maximize the amount of power generated by the switched reluctance generator (SRG) in the low and medium speed operations. There are many control variables which affect the power generated such as: firing angles, reference current, speed and voltage. It will incur high costs and time consuming to modify the variables using experimental set up. Hence, to minimize time, cost and aid in the manufacturing industry, a simulation model of the overall SRG drive is developed. The objective of the work is to identify the optimal parameters and characterize them under closed loop control. The study indicates that there is an optimal voltage, firing angles and reference current at each speed range. Also, the percentage of the power generated can be categorized as a function of dwell angle and speed at optimal voltage level. The optimal dwell angle is determined using the least square method. Within the closed loop system, the high percentage of power generated can be maintained by adjusting the voltage level. It allows operation in single pulse mode as opposed to the conventional current chopping during the low and medium speed.13 page(s
A Comprehensive simulation platform for switched reluctance generator system
A Switched Reluctance Generator (SRG) system normally encompasses three main components: SR machine, controller and converter. On-going research on simulation and modelling of SRG system has focused on one component. There is a lack of a more comprehensive approach which integrates all three components into one simulation platform. We have developed a simulation model comprising SR machine, control and converter using MATLAB/Simulink. The main advantage of a simulation model is to reduce time and cost by having to perform changes on the prototype machine. In this paper, the work is focused on developing the optimal control algorithm for the platform. Optimal parameters are identified and characterized in terms of highest percentage of power generated. From simulation, the most influential parameters affecting the power generated are the firing angles and voltage level. So, a function relating the optimized parameter with machine performance was developed. The proposed control technique will provide easy implementation and ensure high machine performance. The effectiveness of the proposed method is demonstrated by simulation results. The work will aid in development of SRG by providing a platform to determine the best generating operation before real implementation, reducing manufacturing time and cost.11 page(s
Rapid and molecular selective electrochemical sensing of phthalates in aqueous solution
Reported research work presents real time non-invasive detection of phthalates in spiked aqueous samples by employing electrochemical impedance spectroscopy (EIS) technique incorporating a novel interdigital capacitive sensor with multiple sensing thin film gold micro-electrodes fabricated on native silicon dioxide layer grown on semiconducting single crystal silicon wafer. The sensing surface was functionalized by a self-assembled monolayer of 3-aminopropyltrietoxysilane (APTES) with embedded molecular imprinted polymer (MIP) to introduce selectivity for the di(2-ethylhexyl) phthalate (DEHP) molecule. Various concentrations (1ā100 ppm) of DEHP in deionized MilliQ water were tested using the functionalized sensing surface to capture the analyte. Frequency response analyzer (FRA) algorithm was used to obtain impedance spectra so as to determine sample conductance and capacitance for evaluation of phthalate concentration in the sample solution. Spectrum analysis algorithm interpreted the experimentally obtained impedance spectra by applying complex nonlinear least square (CNLS) curve fitting in order to obtain electrochemical equivalent circuit and corresponding circuit parameters describing the kinetics of the electrochemical cell. Principal component analysis was applied to deduce the effects of surface immobilized molecular imprinted polymer layer on the evaluated circuit parameters and its electrical response. The results obtained by the testing system were validated using commercially available high performance liquid chromatography diode array detector system.8 page(s
Development and evaluation of portable low cost testing system for phthalates
A portable low-cost microcontroller based testing system was designed and constructed to detect phthalates in aqueous media. Phthalates, especially di (2-ethylhexyl) phthalate is the most ubiquitous endocrine disrupting compound (EDC) posing highest reproductive toxicity threat to all living species on earth. Frequency response analyser (FRA) approach was used to develop the rapid response, non-invasive electrochemical impedimetric system for detection. A smart thin film gold interdigital electrodes capacitive sensor with enhanced penetration depth was used with the proposed system for detection of the said EDC. The performance of the developed system was evaluated by comparing the results to the commercially available electrochemical Impedimetric frequency response analyzer equipment. Complex nonlinear least square (CNLS) curve fitting algorithm was used to deduce the equivalent circuit for the developed system. The DEHP detection results by the developed system were validated using high performance liquid chromatography (HPLC) diode array detection confirming that the proposed system was able to detect the concentration of phthalates in aqueous medium.7 page(s
Introducing molecular selectivity in rapid impedimetric sensing of phthalates
This research article reports a real-time and non-invasive detection technique for phthalates in liquids by Electrochemical Impedance Spectroscopy (EIS), incorporating molecular imprinting technique to introduce selectivity for the phthalate molecule in the detection system. A functional polymer with Bis (2-ethylhexyl) phthalate (DEHP) template was immobilized on the sensing surface of the inter-digital (ID) capacitive sensor with sputtered gold sensing electrodes fabricated over a native layer of silicon dioxide on a single crystal silicon substrate. Various concentrations (10 to 200 ppm) of DEHP in deionized MilliQ water were exposed to the sensor surface functionalized with molecular imprinted polymer (MIP) in order to capture the analyte molecule, hence introducing molecular selectivity to the testing system. Impedance spectra were obtained using EIS in order to determine sample conductance for evaluation of phthalate concentration in the solution. Electrochemical Spectrum Analyzer algorithm was used to deduce equivalent circuit and equivalent component parameters from the experimentally obtained impedance spectra employing Randle's cell model curve fitting technique. Experimental results confirmed that the immobilization of the functional polymer on sensing surface introduces selectivity for phthalates in the sensing system. The results were validated by testing the samples using High Performance Liquid Chromatography (HPLC-DAD).6 page(s
Sensor and instrumentation for progesterone detection
The reported research work uses a real time and noninvasive method to detect progesterone hormone concentration in purified water using Electrochemical Impedance Spectroscopy (E.I.S.) technique. Planar capacitive sensor, consisting of inter-digitated microelectrodes, is designed and fabricated on silicon substrate using thin-film Microelectromechanical system (MEMS) based semiconductor device fabrication technology. The sensor in conjunction with EIS is used to evaluate conductivity, permeability and dielectric properties of reproductive hormone progesterone and its concentration quantification in purified water. Impedance spectrums are obtained with various concentrations of the hormone in purified water by using an electric circuit in order to extract sample conductance. Relationship of sample conductance with progesterone concentration level is studied in this research work. The ability of E.I.S. to detect progesterone concentration is aimed to be used in dairy farming industry in order to obtain better reproductive performance of the dairy cattle.6 page(s
Development of electrochemical impedance spectroscopy based sensing system for DEHP detection
This research work presents a real time and non invasive technique to detect Di(2-ethylhexyl) phthalate (DEHP)content in purified water and quantify its concentration by Electrochemical Impedance Spectroscopy(E.I.S.). Planar Inter-digital capacitive sensor is employed to evaluate conductivity, permeability and dielectric properties of material under test. This sensor, consisting of inter-digitated microelectrodes, is fabricated on silicon substrate using thin-film Microelectromechanical system (MEMS) based semiconductor device fabrication technology. Impedance spectrums are obtained with various concentrations of DEHP in purified water by using an electric circuit in order to extract sample conductance. Relationship of sample conductance with DEHP concentration is studied in this research work which enables us to show the ability of E.I.S. to detect DEHP concentration in water and hence can be applied in water treatment process for contamination quantification.9 page(s