Investigation of Supra-Harmonics through Signal Processing Methods in Smart Grids

Nowadays supra-harmonic distortion studies are gaining attention day by day in power quality research area. When handling communication systems especially Power Line Carrier (PLC) systems in frequency range 2- 150 kHz, they are suitable for causing electromagnetic interference (EMI) to other systems. This study shows results of analysis employing advanced method called ensemble empirical mode decomposition (EEMD) to describe supra-harmonic distortion. Unlike the traditional method (short time fourier transform- STFT), EEMD gives extensive representation for supra-harmonic component

Electrodynamic forces in compensated pulsed electrical machines

textCompensated pulsed electrical machines of different topologies are located at the forefront of the today technology due to their extremely high power and highly transient and short duration operation. They must operate into a variable structure, carefully tuned system due to the necessity of an optimal drive of the supplied accelerators (e.g. military and civilian such as plasma deposition accelerators.) The present research is dedicated to deriving different means to calculate the extremely high forces occurring in such machines using theoretical and numerical methods in order to assure original designs which can survive the extreme and critical requirements for different topologies the machines. The accurate and expedient evaluation of the electromagnetic field diffusion in pulsed machines conductors as a prerequisite to calculating the exact volume distribution of electromagnetic forces and the necessity of precise but expeditious calculations of forces in compensated structures are addressed. The theoretical electrodynamic approach using the Poynting’s vector in conditions of moving media as a method of electromagnetic power balance is employed for force calculations. Also, finite element method applied to forces in nonlinear magnetic materials and the use of magnetic vector potential for linear magnetic materials is addressed. As a special case of force calculations, a quasistatic magnetic regime of harmonic excitation as applied to underwater electro-acoustic research is analyzed. Finally, a library of cases of actively compensated structures is presented in which a performance evaluation of magnetic flux compression machines is shown, in order to achieve optimal configurations for plasma deposition and plasma spraying using railgun accelerators.Electrical and Computer Engineerin

An Implementation of Exploratory Start for Power Quality Disturbance Pattern Recognition

Identification of system disturbances and detection of them guarantees smart grids power quality system reliability and long lasting life of the power system. The key goal of this study is to generate non - time consuming features for CPU, for recognizing different types of non-stationary and non-linear smart grid faults based on signal processing techniques. This paper proposes a new solution for real time power system monitoring against power quality faults focusing on voltage sag and noise. EEMD is used for noise reduction with first intrinsic mode function (imf1). Hilbert Huang Transform (HHT) is used for generating instantaneous amplitude (IA) and instantaneous frequency (IF) feature of real time voltage sag power signal. The proposed power system monitoring system is able to detect power system voltage sag disturbances and capable of recognize and remove EMI (Electromagnetic Interference)-Noise.  In this study based on experimental studies, Hilbert Huang based pattern recognition technique was used to investigate power signal to diagnose voltage sag in power grid. SVM and Decision Tree (C4.5) were operated and their achievements were matched for calculation error and CPU time. According to the analysis, decision tree algorithm without dimensionality reduction produces the best solution

Results of ICSI in Severe Oligozoospermic and Azoospermic Patients with AZF Microdeletions

Background: The aim of this study was to determine the incidence of AZF (Azoospermia Factor) microdeletions of the Y chromosome in infertile Turkish male patients and intracytoplasmic sperm injection (ICSI) outcome of these patients. Objective: This study was undertaken in order to evaluate the outcome of intracytoplasmic sperm injection (ICSI) in infertil man with AZF microdeletions Materials and Methods: We evaluated 348 azoospermic and oligozoospermic patients retrospectively. Fourty of these patients had various types of AZF microdeletions. These patients had non-obstructive severe oligoasthenospermia or azoospermia with normal karyotype. Azoospermic patients underwent testicular sperm extraction and aspiration (TESE, TESA). Then ICSI was performed to patients who had testicular sperm or ejeculat. Results: Fourty patients with AZF microdeletion were evaluated in this study. No spermium could be found in 27 patients. Three of these patients had only AZFa microdeletion, three had AZFb microdeletion, three had AZF (b+c), six had AZF (a+b+c) and 12 patients had AZFc microdeletion. Only two of all patients achieved a pregnancy and both had only AZFc microdeletion. Conclusion: AZFc microdeletions have a better prognosis for achieving spermium in ejaculate or TESE, TESA materials.Wo

Unexpected condition in a rare disease: encephalopathy in early-onset sarcoidosis

Background. Granulomatous autoinflammatory diseases are monogenic syndromes caused by mutations in the region encoding the nucleotide-binding domain of the nucleotide-binding oligomerization domain-containing 2 gene. Blau syndrome and early-onset sarcoidosis are familial and sporadic forms of the same disease and are very rare. Many organ systems may be involved; however, neurologic involvement is infrequent. We reported a case of encephalitis in a 12-year-old girl followed with a diagnosis of early-onset sarcoidosis

The effect of intra-articular steroid injection on the cartilage and tendon thicknesses in juvenile idiopathic arthritis

Objectives Intra-articular corticosteroid injection (IACI) is a safe first-line or adjunct therapy used in any subtype of juvenile idiopathic arthritis (JIA). Limited studies evaluated the effect of IACI on cartilage. Our study aimed to examine the femoral cartilage thickness of patients with JIA who received IACI to the knee joint using ultrasound.Methods We randomly selected JIA patients who performed IACI in the knee joint. Baseline bilateral joint cartilage and tendon thicknesses were measured. The articular fluid was aspirated, and applied IACI at the same period. Six months after injection, the exact measurements were repeated. Distal femoral cartilage, quadriceps tendon, and distal and proximal patellar tendon thicknesses were compared at the baseline (before IACI) and 6 months after IACI.Results Thirty patients with JIA were included, and 23 (76.7%) were female. The median age was 11 years (interquartile range, 6 to 14), and the median disease duration was 3.3 years (interquartile range, 5 months to 5 years). The subtypes of JIA were oligoarticular in 25 (83.3%), polyarticular in 2 (6.7%), enthesitis-related arthritis in 2 (6.7%), and juvenile psoriatic arthritis in 1 (3.3%). Distal femoral cartilage thickness was 2.96 +/- 0.79 mm at baseline and 2.85 +/- 0.70 mm at 6 months after IACI (P = .35). The tendon thicknesses were similar at 6 months after baseline measurements.Conclusions Our findings reveal that knee IACI in patients with JIA did not significantly change cartilage and tendon thicknesses. This observation could indicate that IACIs have no detrimental effects on the cartilage and the tendons

Assessing the Quality of Life of Dental Students by using the WHOQOL-BREF Scale

Background/Aim: The study aimed to evaluate the quality of life (QOL) of dental students in a private dental school with the use of the WHOQOLBREF scale

Evaluation of liver elasticity with shear-wave elastography in juvenile idiopathic arthritis patients receiving methotrexate

Background Methotrexate (MTX) is the first-choice disease-modifying drug in juvenile idiopathic arthritis (JIA) treatment. Methotrexate is metabolized in the liver and can cause liver toxicity and fibrosis with long-term use. Ultrasound shear wave elastography (SWE) is a non-invasive method and can detect liver fibrosis by evaluating the liver elasticity. The aim of this study was to assess liver stiffness and detect if there is an increase in liver stiffness or fibrosis findings with the non-invasive SWE method in JIA patients under MTX treatment. Method The study included 49 JIA patients under MTX treatment and 48 healthy controls, matched for age and sex with a body mass index below the 95th percentile. The demographic data and clinical characteristics of patients were obtained from medical records. Liver function tests were evaluated, and liver tissue stiffness measurements were performed with SWE. Results Of the 49 patients, 67.35% were girls and the mean age was 10.69 (+/- 4.33) years. The duration of MTX treatment was 23.00 (1-80) months, and the cumulative dose of MTX was 1,280.867 mg (+/- 934.2) in the patient group. There was no statistically significant difference in liver stiffness between patients receiving MTX and healthy controls (P = 0.313). There was no relationship between MTX duration, cumulative dose, route of administration, and liver stiffness. Only gamma glutamyl transferase values were weakly correlated with liver stiffness (P = 0.029). Conclusions We did not detect an increase in liver tissue stiffness in JIA patients using methotrexate in comparison with controls