Fuzzy-based estimation of reference flux, reference torque and sector rotation for performance improvement of DTC-IM drive

In this study, the fuzzy-based reference flux estimator (RFE), reference torque estimator (RTE) and sector rotation strategy called fuzzy logic estimator are proposed to direct torque control of induction motor (DTC-IM) drive for performance improvement. The basic DTC-IM drive with conventional RFE, RTE and sector division causes large torque ripple, variable switching frequency and uneven voltage vector contribution in stator flux. The torque and speed responses of the proposed system are investigated with load variations. The simulation results of the proposed DTC-IM drive are compared with the basic DTC-IM drive. The assessment of the proposed system shows improved performance. A hardware is developed using Xilinx Spartan-6XC6SLX45-Field Programmable Gate Array (FPGA) Kit for experimental verification of the results. Moreover, sinusoidal pulse width modulation and space vector pulse width modulation techniques are applied to reduce the torque ripples. The performance of the drive is investigated for various speed ranges. The comparison of the simulated and experimental results proves that the proposed fuzzy-based DTC-IM drive provides better performance than the basic DTC-IM drive

Investigation on the photocatalytic activity of chemically synthesized zirconium doped cadmium selenide nanoparticles for indigo carmine dye degradation under solar light irradiation

A simple chemical methodology has been adopted for the synthesis of zirconium (Zr) doped and un-doped cadmium selenide (CdSe) nanoparticles for the application towards photocatalytic degradation of indigo carmine (IC) dye under solar light irradiation. The as prepared Zr-CdSe (doped) and CdSe (un-doped) nanoparticles were characterized by ultraviolet visible spectroscopy (UV-vis), X-ray diffraction (XRD), Scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDAX) and Transmission electron microscopy (TEM) studies. The inclusion of Zr ion into the CdSe nanoparticles matrix was confirmed by SEM-EDAX and XRD studies. TEM studies confirm the zirconium ions are uniformly doped over the CdSe surface. The photocatalytic degradation performance of Zr doped and un-doped CdSe nanoparticles were examined for the degradation of IC dye under solar light irradiation. The experimental results showed that the Zr doped CdSe possessed greater photocatalytic activity in comparison to un-doped CdSe. Photodegradation process parameters such as the initial concentration of the dye, as well as the amount of catalyst and time were investigated. The photocatalytic degradation rate was favored by a high concentration of solution in respect to Langmuir–Hinshelwood model

ELECTROCHEMICAL STUDIES OF PARACETAMOL ON POLYANILINE-SILVER NANOSTRUCTURAL THIN FILMS MODIFIED GLASSY CARBON ELECTRODE

Analysis of biomolecule of paracetamol through stripping voltammetric determination procedure on polyaniline-silver thin films modified glassy carbon electrode. The effect of pH was studied at different pH media such as 1.0 to pH 13.0. The voltammetric investigation of paracetamol was carried out from −0.2 V to 1.2 V versus Ag/AgCl using modified glassy carbon (GC) as working electrode. The electroanalytical determination parameters are highly dependent on their configuration and on the dimensions of the working carbon electrode. The cyclic voltammogram exhibited one oxidation and one reduction peak. Peak current dependence on the scan rate is studied by varying the scan rate from 25 to 500 mv/s at concentration 300 ppm. The best limit of detection obtained for paracetamol was 10 ppb and the linear range from 100 to 600 ppb on GCE configuration. The biosensors were successfully applied for the detection of paracetamol in several drug formulations

Simulation of 3-phase matrix converter using space vector modulation

This paper illustrates the simulation of 3-phase matrix converter using Space Vector Modulation (SVM). Variable AC output voltage engendered using matrix converter with bidirectional power switches controlled by appropriate switching pulse. The conventional PWM converter engenders switching common mode voltage across the load system terminals, which cause to common mode current and its leads to bearing failure in load drive. These problems can be rectified using SVM and which minimize the effect on the harmonic fluctuation in AC output voltage and stress on the power switch is reduced using bidirectional switch for proposed 3-phase matrix converter. The simulation results have been presented to validate the proposed system using matlab / simulink

Surfactant-mediated and morphology-controlled nanostructured LiFePO4/carbon composite as a promising cathode material for Li-ion batteries

The synthesis of morphology-controlled carbon-coated nanostructured LiFePO4 (LFP/Carbon) cathode materials by surfactant-assisted hydrothermal method using block copolymers is reported. The resulting nanocrystalline high surface area materials were coated with carbon and designated as LFP/C123 and LFP/C311. All the materials were systematically characterized by various analytical, spectroscopic and imaging techniques. The reverse structure of the surfactant Pluronic® 31R1 (PPO-PEO-PPO) in comparison to Pluronic® P123 (PEO-PPO-PEO) played a vital role in controlling the particle size and morphology which in turn ameliorate the electrochemical performance in terms of reversible specific capacity (163 mAhg 1 and 140 mAhg 1 at 0.1 C for LFP/C311 and LFP/ C123, respectively). In addition, LFP/C311 demonstrated excellent electrochemical performance including lower charge transfer resistance (146.3 Ω) and excellent cycling stability (95% capacity retention at 1 C after 100 cycles) and high rate capability (163.2 mAhg 1 at 0.1 C; 147.1 mAhg 1 at 1 C). The better performance of the former is attributed to LFP nanoparticles (< 50 nm) with a specific spindle-shaped morphology. Further, we have also evaluated the electrode performance with the use of both PVDF and CMC binders employed for the electrode fabrication

Infrared Thermography for the Ante Mortem Detection of Bruising in Horses Following Transport to a Slaughter Plant

Undetected injury of horses sustained during road transport to slaughter is a welfare concern. This study evaluated digital infrared thermography (DT) for the detection of ante-mortem bruising in horses following transport to a slaughter plant. The sensitivity and specificity of DT for the detection of bruises following transport was evaluated. DT images were obtained from 93 horses (2–3 horses per load; 40 loads) at a Canadian federally approved slaughter plant. From an elevated platform 5 m from the horses, left and right lateral DT images, and one caudal pelvic area image were obtained from each horse. After slaughter the carcasses were examined for bruising (a visually discolored area on the carcass caused by damage to the blood vessels) and findings documented. Sensitivity, specificity, and predictive values were calculated for DT assessment of bruising. The prevalence of bruising on post mortem inspection was 54%. The DT approach to bruise detection at the region of interest level of 93 horses (n = 186 sides) resulted in a sensitivity of 42% and specificity of 79%. As the sensitivity was low, a more sensitive DT camera and allowing for a longer equilibration time for horses after transport may improve this approach to post transport assessment of subclinical injury

The oxidative stress of hyperglycemia and the inflammatory process in endothelial cells

Hyperglycemia and insulin resistance are common in many critically ill patients. Hyperglycemia increases the production of reactive oxygen species in cells, stimulates the production of the potent proinflammatory cytokines IL-8 and TNF-alpha, and enhances the expression of haem oxygenase-1, an inducible stress protein. It has been shown that administration of insulin and the semi-essential amino acid glutamine have been beneficial to the septic patient. The aim of our study is to test whether these two molecules, glutamine and insulin used in combination attenuate the proinflammatory responses in endothelial cells which have been triggered by hyperglycaemia. Our results demonstrate that a combination of insulin and glutamine are significantly more effective in reducing the expression of IL-8, TNF-alpha and HO-1 than insulin or glutamine alone

“Nano”: an emerging avenue in electrochemical detection of neurotransmitters

The growing importance of nanomaterials toward the detection of neurotransmitter molecules has been chronicled in this review. Neurotransmitters (NTs) are chemicals that serve as messengers in synaptic transmission and are key players in brain functions. Abnormal levels of NTs are associated with numerous psychotic and neurodegenerative diseases. Therefore, their sensitive and robust detection is of great significance in clinical diagnostics. For more than three decades, electrochemical sensors have made a mark toward clinical detection of NTs. The superiority of these electrochemical sensors lies in their ability to enable sensitive, simple, rapid, and selective determination of analyte molecules while remaining relatively inexpensive. Additionally, these sensors are capable of being integrated in robust, portable, and miniaturized devices to establish point-of-care diagnostic platforms. Nanomaterials have emerged as promising materials with significant implications for electrochemical sensing due to their inherent capability to achieve high surface coverage, superior sensitivity, and rapid response in addition to simple device architecture and miniaturization. Considering the enormous significance of the levels of NTs in biological systems and the advances in sensing ushered in with the integration of nanotechnology in electrochemistry, the analysis of NTs by employing nanomaterials as interface materials in various matrices has emerged as an active area of research. This review explores the advancements made in the field of electrochemical sensors for the sensitive and selective determination of NTs which have been described in the past two decades with a distinctive focus on extremely innovative attribut,es introduced by nanotechnology