Micro controller and computer based reactive power compensation

Metode za kompenzaciju jalove snage su među najučinkovitijim metodama za povećanje učinkovitosti energetskih sustava. Stoga su projektiranje i primjene tih sustava vrlo važni. Cilj ovog istraživanje je projektirati i primijeniti sustave za kompenzaciju jalove snage koji najviše odgovaraju elektroenergetskim sustavima. Kompenzacija jalove snage može se realizirati primjenom električnih kompenzatora ili sinkronih motora. U ovom radu, kompenzacije pomoću mikroregulatora i računala izvršene su primjenom električnih kompenzatora i sinkronih motora pod istim uvjetima opterećenja. Pomoću takvog sustava pokušalo se odrediti koja je vrsta kompenzacije jalove snage pogodna u postojećem sustavu. U tu su se svrhu pokušala izbjeći nepotrebna ulaganja u postojeći sustav i stvoriti kvalitetan kompenzacijski sustav. Uz to, projektirani se sustav može lako prilagoditi svim vrstama promjena opterećenja te ne zahtijeva dodatnu opremu.Reactive power compensation methods are one of the most effective methods to improve the efficiency of energy systems. Therefore, the designs and implementations of these systems are important. The aim of this study is to design and implement the most appropriate reactive power compensation systems in electrical power systems. Reactive power compensation can be realized using capacitors or the synchronous motors. In this study, a microcontroller and computer-controlled compensation applications are done by capacitors and synchronous motors under the same load conditions has been performed. By means of this designed system, it has been tried to determine what type of reactive power compensation is suitable in the existing system. In this respect, it is aimed to avoid unnecessary investments for existing systems and to establish a quality compensation system. In addition, the designed system is easy to update against all kinds of load changes and does not require additional equipment

Using covariates for improving the minimum redundancy maximum relevance feature selection method

Maximizing the joint dependency with a minimum size of variables is generally the main task of feature selection. For obtaining a minimal subset, while trying to maximize the joint dependency with the target variable, the redundancy among selected variables must be reduced to a minimum. In this paper, we propose a method based on recently popular minimum Redundancy-Maximum Relevance (mRMR) criterion. The experimental results show that instead of feeding the features themselves into mRMR, feeding the covariates improves the feature selection capability and provides more expressive variable subsets

B-mode ultrasound assessment of carotid artery structural features in patients with normocalcaemic hyperparathyroidism

Introduction: Normocalcaemic hyperparathyroidism is a condition first defined in 2008, characterized by normal serum calcium and high parathormone levels. Although normocalcaemic hyperparathyroidism is considered to have a milder clinical picture compared to asymptomatic primary hyperparathyroidism, recent studies have shown that it may be associated with osteoporosis, insulin resistance, metabolic syndrome, and cardiovascular risk factors. Considering that normocalcaemic hyperparathyroidism may pose a cardiovascular risk in the setting of carotid atherosclerosis, we sought to examine the structural features of the carotid artery in patients with normocalcaemic hyperparathyroidism compared to a control group. Material and methods: After excluding patients with hypertension, diabetes, and dyslipidaemia (other factors contributing to atherosclerosis), 37 (32 females, 5 males) patients with normocalcaemic hyperparathyroidism with a mean age of 51.2 ± 8 (min: 32, max: 66) years and 40 controls (31 females, 9 males) with a mean age of 49.3 ± 7.5 (min: 34, max: 64) years with normal serum albumin-corrected calcium and parathyroid hormone levels were included in the study. Structural features of the carotid artery including intima-media thickness (mean and maximum), lumen diameter, and the presence of plaque were assessed using B-mode ultrasound. Results: On ANCOVA analysis corrected for atherosclerotic factors (body mass index, waist circumference, fasting plasma glucose, serum cholesterol, lipid, and blood pressure), greater mean intima-media thickness was found in patients with normocalcaemic hyperparathyroidism than in controls (0.65 mm vs. 0.59 mm, respectively) (p = 0.023). Maximum carotid intima-media thickness was also greater in patients with normocalcaemic hyperparathyroidism compared to controls (0.80 mm vs. 0.75 mm, respectively) (p = 0.044). The study groups did not show a significant difference in lumen diameter and the presence of carotid plaque. In addition, a negative correlation was found between parathormone (PTH) level and lumen diameter. Conclusion: The findings of this study show that as with asymptomatic primary hyperparathyroidism, normocalcaemic hyperparathyroidism may be associated with increased cardiovascular risk by predisposing to atherosclerosis

Cytocompatibility of Novel Algae-PLA Membranes For Guided Bone Regeneration At The Level of Types I, III And V Collagen Expression

Statement of the problem: In recent years, the development of innovative and increasingly optimized barrier membranes has focused on marine algae, which as a biopolymer can form a membrane composite together with polylactic acid, thus a combination could show numerous advantages such as antioxidant, antitumor, antibacterial, antiviral as well as antiallergic properties. Furthermore, algae can be produced in an ecologically sustainable way and offer an alternative for patients who refuse treatment with bovine or porcine derived membranes due to ethical or religious reasons.Objective: In this study, four different algal membranes were evaluated for their cytocompatibility with cultured human fibroblasts and osteoblasts.Materials & Methods: Mem-Lok® (Collagen Matrix, New Jersey, USA) as a resorbable collagen membrane and ArgonautTM (Botiss Biomaterials, Zossen, Germany) as a native pericardium GBR/GTR membrane served as reference membranes (RMs). As the negative control cells incubated with normal culture medium only were used. In addition to the cell viability and proliferation assays water soluble tetrazolium (WST), MTT and BrdU, a real time semiquantitative real time PCR (RT-PCR) was developed to investigate in vitro cytocompatibility at the level of types I, III and V collagen expression. A sandblasted- large grid-acid ached titanium surface (Dentcon® Dental Implant Systems, Ankara, Turkey) served as a positive inactive control group for osteoblastic cytocompatibility.Results: For human osteoblasts, the algal membranes showed very good proliferation levels in WST-1, MTT as well as BrdU, indicating cytocompatibility. Examination of the expression behavior of type I, type III, and type V collagen genes showed no evaluable results. However, the RT-PCR should be repeated with the incorporated optimizations to be able to make a statement regarding the success of bone, skin, and connective tissue regeneration after a possible application of the membrane in maxillofacial injury treatment.Conclusion: The investigated collagen types are essential for a proper healing of defects in both soft and bone tissue, as they have fundamental functions such as stability and structural integrity of the tissues

Volume CXIV, Number 4, November 7, 1996

Objective: Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population.Methods: Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014.Results: The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosis) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto's thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%.Conclusion: This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespa

Comparison Of Expert And Classical Systems Of Power Factor Control With Synchronous Motor

Elektrik enerjisinde verim; hizmet kalitesinden ve üretim miktarından ödün verilmeden bir işin daha az enerji kullanılarak yapılabilmesidir. Elektrik enerji sistemlerinde verimliliği arttırmanın ve enerji tasarrufunu sağlamanın en etkin önlemlerinden biri "Reaktif Güç Kompanzasyonu" dur. Reaktif güç kompanzasyonu iki işletme aracı kullanılarak yapılabilmektedir. Bu işletme araçları kondansatörler ve senkron motorlardır.Bu çalışmada, farklı yük koşullarında 3 fazlı bir sistem için hem kondansatör hem de senkron motor ile kompanzasyon uygulamaları tekrarlanmış ve sonuçlar analiz edilmiştir. Kompanzasyon uygulamaları hem manuel hem de otomatik kumanda şeklinde yapılmıştır. Manuel kumanda; kompanzasyon deneylerinin yapılması ve otomatik kumanda için gerekli veri tabanının oluşturulması için kullanılmıştır. Otomatik kumanda; kondansatör ile yapılan kompanzasyonda, belirlenen aralıklarda tanımlanmış kondansatör ya da kondansatör gruplarının anahtarlanması şeklinde, senkron motor ile yapılan kompanzasyonda ise YSA denetiminde gerçekleştirilmiştir. Sisteme ait U, I, Cosφ, P, F parametreleri tasarlanan devre ile tek fazdan ölçülmüştür. Ek olarak oluşturulan arayüz ile bu parametreler bilgisayardan izlenmiş ve sistemin kontrolü sağlanmıştır.Efficiency in electricity; A business without compromising on service quality and quantity of production can be done by using less energy. One of the most effective measures to provide productivity growth and energy saving in the electricity system is "Reactive Power Compensation". Reactive power compensation can be done using two business tool. These business tools are capacitors and synchronous motors.In this study, applications of both capacitors and synchronous motors were repeated for a 3-phase system with different loads and their results were analysis. The compensation applications were performed in the form of both manual and automatic control. Manuel control was used to perform the experiments of compensation and to consist of the database required for the automatic control. While automatic control method was performed with the switching of groups of capacitors or capacitor in the previous described range for capacitors, it was executed under the control of ANN (Artificial Neural Networks) in the compensation done with synchronous motors. The parameters U, I, Cosφ, P, F belonging to the system were measured from single phase by means of the envisaged circuit. Furthermore, these parameters were made monitoring in silco by the interface coded and system control were mantained by it

Heavy metal contents and the water quality of Karasu Creek in Nigde, Turkey

WOS: 000252295500014PubMed ID: 17525832Different sources of pollution in Karasu Creek were investigated to obtain the water quality and ratio of contamination in this region. To achieve the main objectives of the present study, water samples were collected from Karasu Creek, starting from flow pattern at the upstream site of Akkaya Dam to the end of the dam, crossing the place where the Creek drains into. Dissolved oxygen, electrical conductivity, temperature and maximum/minimum pH were measured systematically for 12 months in the stations, where the water samples were collected. Chemical analyses of the water samples were carried out by using Cadas 50 S brand UV spectrometer to find out the Pb, Fe, Cu, Zn, Ni, Cr, Cd, S, F and Cn concentrations. These concentration were determined in mu g/lt as 80-850; 180-4,920; 10-6,100; 440-25,530; 130-2,400; 120-280; 20-150; 214,250-1,113,580; 1,560-4,270 and 40-690, respectively. To determine metal levels of the water samples, multivariate analyses (element coefficient correlation, coefficient correlation dendrogram, hierarchical cluster analysis dendrogram, model summary and ANOVA) were used. The analyses yielded highly accurate results. There were positive correlations between some elements and their possible sources were the same. The stations which resembled each other along the creek were divided into three groups. The water quality of the creek was low and had toxic qualities. Eutrophication developed in Akkaya Dam along the creek. The source of pollution was thought to be industrial and residential wastes. Absolute (0-100 m), short distance (100-500 m) and medium distance (500-2,000 m) conservation areas should be determined in pollution areas along Karasu Creek and they should be improved