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

Wall shear stress and pressure patterns in aortic stenosis patients with and without aortic dilation captured by high-performance image-based computational fluid dynamics.

Spatial patterns of elevated wall shear stress and pressure due to blood flow past aortic stenosis (AS) are studied using GPU-accelerated patient-specific computational fluid dynamics. Three cases of moderate to severe AS, one with a dilated ascending aorta and two within the normal range (root diameter less than 4cm) are simulated for physiological waveforms obtained from echocardiography. The computational framework is built based on sharp-interface Immersed Boundary Method, where aortic geometries segmented from CT angiograms are integrated into a high-order incompressible Navier-Stokes solver. The key question addressed here is, given the presence of turbulence due to AS which increases wall shear stress (WSS) levels, why some AS patients undergo much less aortic dilation. Recent case studies of AS have linked the existence of an elevated WSS hotspot (due to impingement of AS on the aortic wall) to the dilation process. Herein we further investigate the WSS distribution for cases with and without dilation to understand the possible hemodynamics which may impact the dilation process. We show that the spatial distribution of elevated WSS is significantly more focused for the case with dilation than those without dilation. We further show that this focal area accommodates a persistent pocket of high pressure, which may have contributed to the dilation process through an increased wall-normal forcing. The cases without dilation, on the contrary, showed a rather oscillatory pressure behaviour, with no persistent pressure "buildup" effect. We further argue that a more proximal branching of the aortic arch could explain the lack of a focal area of elevated WSS and pressure, because it interferes with the impingement process due to fluid suction effects. These phenomena are further illustrated using an idealized aortic geometry. We finally show that a restored inflow eliminates the focal area of elevated WSS and pressure zone from the ascending aorta

Enhancement of NMP degradation under UV light by nitrogen-doped TiO2 thin films using a design of experiment

Doping nitrogen within TiO2 is an effective way to enhance visible light photocatalysis due to a direct electron excitation from the N2p states within the band gap. However, nitrogen doping is not always efficient for UV photocatalytic activity. Here, different structures of N-doped TiO2 (TiOxNy) have been prepared by reactive RF (13.56 MHz) magnetron sputtering. The morphological, optical, structural, and photocatalytic properties of the films have been studied in order to investigate the competitive effect of the morphology and the chemical composition on the efficiency of the photocatalytic activity. The variation of surface wettability of the film over time in the dark and under visible and UV irradiation was also studied. The reduction in wettability by dark storage can be explained by the adsorption of hydrocarbon contamination on the thin film’s surface. Additionally, from water contact angle experiments, it was found that these films developed hydrophilic properties upon UV and visible illumination. The photoinduced change in the contact angle of water was due to the removal of hydrocarbon contamination on the surface and also the photo-oxidation of the water droplet. Samples prepared at high pressure gave the best photocatalytic activity, even though the deposition rate was lower at higher pressures (lower film thicknesses), due to the high specific surface area and the optimal presence of TiOxNy crystals in the lattice. However, at low pressure, the TiN crystals became more predominant, and acted as recombination centers for the photo-generated charge carriers. A design of experiments was used in order to optimize the deposition parameters to have the best photocatalytic activity. The high photocatalytic activity under UV light was found to be due to the introduction of discrete energy levels within the band gap, the increased sample wettability, and the higher specific surface area. However, the post annealing process did not effect the activity under UV irradiation. Using the response surface methodology, RSM, based on a design of experiment, DOE, we are able to achieve a good understanding of the complex processes involved in the deposition of the thin films and their effect on the photocatalytic activity. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/930

Detection of hepatitis B virus covalently closed circular DNA in the plasma of Iranian HBeAg-negative patients with chronic hepatitis B

Background: Covalently closed circular DNA (cccDNA) of hepatitis B virus (HBV) is a marker of HBV replication in the liver of patients infected with HBV. Objectives: This study aimed to investigate the association between the presence of cccDNA in the plasma samples of Iranian treatment-naive patients with chronic hepatitis B infection and HBV viral load and HBsAg levels. Patients and Methods: From April 2012 to May 2015, 106 treatment-naive patients with chronic hepatitis B infection were enrolled in this cross-sectional study. The HBsAg titer was measured by the Roche HBsAg II assay on the Cobas e411 system, and HBV DNA quantitation was performed using the COBAS TaqMan 48 kit. Real-time polymerase chain reaction was performed for the detection of HBV cccDNA. Results: The mean (SD) age of the patients was 41.1 ± 12.4 years (range, 20 - 62 years). From a total of 106 study participants, 67 (63.2) were males. The HBV cccDNA was detected in plasma specimens in 19 (17.9) out of the total 106 patients, and a significant relationship was found between the presence of cccDNA in plasma sample of males (23.9) and females (7.7) (P = 0.039). Also, a significant correlation was found between the presence of cccDNA in plasma sample of the patients and HBV viral load level (P < 0.0001) and HBsAg titer (P = 0.0043). Conclusions: This study showed that cccDNA can be detected in the plasma specimen of 17.9 of Iranian treatment-naive patients with chronic hepatitis B infection. Therefore, designing prospective studies focusing on the detection of cccDNA in these patients would provide more information. © 2015, Kowsar Corp

The impact of nurse short message services and telephone follow-ups on diabetic adherence: Which one is more effective?

Aim. To compare the effectiveness of two methods of follow-up: short message service and telephone follow-up on type 2 diabetes adherence for threemonths. Background. Using telemedicine approaches may preserve appropriate blood glucose levels and may improve adherence to diabetes control recommendations in diabetic patients. Design. A quasi-experimental, two-group, pretest and post-test design was used in this study to evaluate the effectiveness of nurse's follow-up via cellular phones and telephones. Methods. The sample consisted of 77 patients with type 2 diabetes that randomly were assigned to two groups: telephone follow-up (n=39) and short message service (n=38). Telephone interventions were applied by a researcher for threemonths; twice a week for the first month and every week for the second and third month. For three successive months, the short message service group that received messages about adherence to therapeutic regimen was examined. The data gathering instrument included data sheets - to record glycosylated haemoglobin - and the questionnaire related to adherence therapeutic regimen. Data gathering was carried out at the beginning of the study and after three and sixmonths. The data were analysed using descriptive and inferential statistic methods with SPSS version 11.5. Results. Results showed that both interventions had significant mean changes in glycosylated haemoglobin. For the telephone group (p<0·001), a mean change of -0·93 and for the short message service group (p<0·001), a mean change of -1·01. There was no significant difference in diet adherence (p=0·000), physical exercise (p=0·000) and medication taking (p=0·000) adherence in either groups. Conclusion. Intervention using short message services of cellular phones and nurse-led-telephone follow-up improved HbA1c levels and adherence to diabetes therapeutic regimen for threemonths in type 2 diabetic patients. Relevance to clinical practice. Both of follow-up intervention uses in this study can decrease HbA1c levels and escalate adherence to diabetes control recommendations in people with type 2 diabetes for three months. © 2012 Blackwell Publishing Ltd

The impact of nurse short message services and telephone follow-ups on diabetic adherence: Which one is more effective?

Aim. To compare the effectiveness of two methods of follow-up: short message service and telephone follow-up on type 2 diabetes adherence for threemonths. Background. Using telemedicine approaches may preserve appropriate blood glucose levels and may improve adherence to diabetes control recommendations in diabetic patients. Design. A quasi-experimental, two-group, pretest and post-test design was used in this study to evaluate the effectiveness of nurse's follow-up via cellular phones and telephones. Methods. The sample consisted of 77 patients with type 2 diabetes that randomly were assigned to two groups: telephone follow-up (n=39) and short message service (n=38). Telephone interventions were applied by a researcher for threemonths; twice a week for the first month and every week for the second and third month. For three successive months, the short message service group that received messages about adherence to therapeutic regimen was examined. The data gathering instrument included data sheets - to record glycosylated haemoglobin - and the questionnaire related to adherence therapeutic regimen. Data gathering was carried out at the beginning of the study and after three and sixmonths. The data were analysed using descriptive and inferential statistic methods with SPSS version 11.5. Results. Results showed that both interventions had significant mean changes in glycosylated haemoglobin. For the telephone group (p<0·001), a mean change of -0·93 and for the short message service group (p<0·001), a mean change of -1·01. There was no significant difference in diet adherence (p=0·000), physical exercise (p=0·000) and medication taking (p=0·000) adherence in either groups. Conclusion. Intervention using short message services of cellular phones and nurse-led-telephone follow-up improved HbA1c levels and adherence to diabetes therapeutic regimen for threemonths in type 2 diabetic patients. Relevance to clinical practice. Both of follow-up intervention uses in this study can decrease HbA1c levels and escalate adherence to diabetes control recommendations in people with type 2 diabetes for three months. © 2012 Blackwell Publishing Ltd