New Model Reference Adaptive System Speed Observer for Field-Oriented Control Induction Motor Drives Using Neural Networks

One of the primary advantages of field-oriented controlled induction motor for high performance application is the capability for easy field weakening and the full utilization of voltage and current rating of the inverter to obtain a wide dynamic speed rangeThis paper describes a Model Reference Adaptive System (MRAS) based scheme using Artificial Neural Network (ANN) for online speed estimation of sensorless vector controlled induction motor drive. The proposed MRAS speed observer uses the current model as an adaptive model. The neural network has been then designed and trained online by employing a back propagation network (BPN) algorithm. The estimator was designed and simulated in Matlab/Simulink. Simulation result shows a good performance of speed estimator. The simulation results show good performance in various operating conditions. Also Performance analysis of speed estimator with the change in resistances of stator is presented. Simulation results show this estimator robust to parameter variations especially resistances of stator

New Model Reference Adaptive System Speed Observer for Field-Oriented Control Induction Motor Drives Using Neural Networks

One of the primary advantages of field-oriented controlled induction motor for high performance application is the capability for easy field weakening and the full utilization of voltage and current rating of the inverter to obtain a wide dynamic speed rangeThis paper describes a Model Reference Adaptive System (MRAS) based scheme using Artificial Neural Network (ANN) for online speed estimation of sensorless vector controlled induction motor drive. The proposed MRAS speed observer uses the current model as an adaptive model. The neural network has been then designed and trained online by employing a back propagation network (BPN) algorithm. The estimator was designed and simulated in Matlab/Simulink. Simulation result shows a good performance of speed estimator. The simulation results show good performance in various operating conditions. Also Performance analysis of speed estimator with the change in resistances of stator is presented. Simulation results show this estimator robust to parameter variations especially resistances of stator

Association of IFN-γ and P2X7 Receptor Gene Polymorphisms in Susceptibility to Tuberculosis Among Iranian Patients

Interferon-gamma (IFN-γ) and P2X7 receptor are crucial for host defence against mycobacterial infections. Recent studies have indicated that IFN-γ, IFN-γ receptor 1 (IFN-γR1) andP2X7 gene polymorphisms are associated with susceptibility to pulmonary tuberculosis (TB). However, the relationship between IFN-γ and P2X7 polymorphism and TB susceptibility remains inconclusive in Iranian population. For this reason, single nucleotide polymorphisms (SNPs) in IFN-γ (G+2109A), IFN-γR1 (G-611A) and P2X7 genes (at –762, 1513 position) in patients (n = 100) were assessed using PCR-RFLP. Data were analysed with SPSS version 18. For the 2109 loci of IFN-γ gene, the frequency of mutant alleles between patients and controls were not statistically significant. However, there was a significant difference between the TB patient and controls for –611 alleles of IFN-γR1 (P = 0.01). Additionally, the frequency of P2X7 gene polymorphisms (SNP-762 and 1513) between patients and controls was statistically significant. In conclusions, our study revealed a significant association of IFN-γR1 and P2X7 genes polymorphisms with risk of developing TB in Iranian population

A New Robust Nonlinear Control Strategy for UIPC in Isolated Hybrid Microgrids

This paper focuses on the control of unified interphase power controller (UIPC) in isolated hybrid microgrids (HmGs), where the UIPC is used as the main component for interconnecting of AC and DC sub-grids. The investigated HmG encompasses two AC sub-grids and one purely storage DC sub-grid (PSDC) and multiple adjustable loads. A robust nonlinear model reference adaptive control (NMRC) strategy is offered for controlling the UIPC, keeping an acceptable two-way power exchange control with uncomplicated topology. Further, a novel configuration for the DC link power converter is suggested using the dual-active-bridge topology. Also, a harmonic-based modeling method is used to model the UIPC's power converter. The proposed configuration provides bidirectional power flow, increased power density, straightforward adaptation of zero-voltage switching, and direct access to cascading and parallelism to increase the ratings and reliability of UIPC. The simulation results illustrate the feasibility of the suggested topology for isolated HmGs

Evaluation and Optimization of Acanthophyllum Extract in Washing of the Historical Textiles

Contamination is an unwanted threat, which affects the health and the artistic features of a piece of textile. One of the most important concerns in the area of protection of historical woven fabrics is the presentation and use of safe materials and methods for the historic works. So far, many researchers have been working on this field and have caused a lot of changes in this field. The purpose of this research is to apply Acanthophyllum extract to the cleaning and washing of historical cotton fabrics. For this purpose, after preparing the Acanthophyllum, using the Soxhlet method, the extract of hydro-alcoholic was obtained. The extract was applied, as a detergent, to the prepared contaminated samples in the washing step. In the washing process, all constant independent variables were concerned, and only three concentrations of extract, washing frequency and times were considered in the design of the test, using a Central Composite Design (CCD). The detection of delta DE* by spectrophotometer as a dependent variable expresses the effect of extract cleansing rate. The results show that extract concentrations, washing frequency and time are most effective in cleaning the contamination. However, the adopted washing process and the applied materials had the least impact on reducing the strength of the fabric

Gas Chromatography-Mass Spectrometry Analysis of Agricultural Residues using Indigenous Laccase producing Fungi (Albifimbria viridis) as Herbicides

Background and Objective: Discarded as wastes, parts of the agricultural products can be used for feed productivity as well as management of animal feed production. Production of various products is possible using appropriate processing. The objective of the present study was to use laccase of Albifimbria viridis in degradation of agricultural residues and to produce compounds with herbicide properties. Material and Methods: The fungi were isolated from agricultural soils. The isolates were identified using morphological detection and PCR amplification of the internal transcribed spacer. Supernatants were collected from semi-solid cultures and laccase activity was assessed using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) substrate. This was carried out using n-hexane and degradation of the agricultural residues was investigated using gas chromatography-mass spectrometry. Results and Conclusion: Growth of the fungal isolate in culture media with tannic acid was studied using scanning electron microscopy. In total, the isolate produced 50 U ml-1 laccase. Gas chromatography-mass spectrometry analyses revealed production of oxime, methoxy-phenyl and 2-cyclopenten-1-one for tannic acids, o-guaiacol, tetradecane, hexadecane, octadecane, octadecanoic acid, hexadecanoic acid and benzene, 1,3-bis(1,1-dimethylethyl) for sorghum seeds and 2-acetyl-5-methylfuran, phenol, 2-methoxy and benzene, 1,2-dimethoxy for wheat straw during fungal growth (0.73 mg ml-1). Results have shown that the laccase enzyme produced from Albifimbria viridis native strain is capable of hydrolytic cleavage of chemical pollutants from agricultural wastes for herbicide bioremediation. Conflict of interest: The authors declare no conflict of interest