84 research outputs found
Analysis of a Novel Four Level Flying Capacitor H – Bridge Converter
In this paper, a novel four-level flying capacitor inverter and its comparison with the conventional flying capacitor topology in terms of THD analysis are proposed. This new topology have some advantages over conventional one as following: The blocking voltages are the same for all switches used in the configuration, there is no need for capacitor midpoint connection and this eliminates low frequency current which circulate in dc-link capacitors, and the number of flying capacitor is reduced as compared with conventional form of it. The operation of the topology, modulation strategy, simulation results, and THD analysis for the output waveforms are presented in this paper.Article History: Received: 17th July 2017; Received: October 14th 2017; Accepted: Januari 18th 2018; Available onlineHow to Cite This Article: Gülpınar, F., Sarı, F., and Uzun, Y. (2017) Analysis of a Novel Four Level Flying Capacitor H – Bridge Converter. International Journal of Renewable Energy Development, 7(1), 71-75.https://doi.org/10.14710/ijred.7.1.71-7
The Evaluation of Water Sorption/Solubility on Various Acrylic Resins
Objectives: The absorption of water by acrylic resins is a phenomenon of considerable importance since it is accompanied by dimensional changes, a further undesirable effect of absorbed water in acrylic resins to reduce the tensile strength of the material. Solubility is also an important property because it represents the mass of soluble materials from the polymers. Methods: Ten acrylic resin-based materials were evaluated: two heat cure acrylic resins (De Trey QC-20, Meliodent Heat Cure) and eight self cure acrylic resins (Meliodent Cold, Akrileks, Akribel, Akribel Transparent, Vertex Trayplast, Formatray, Dentalon Plus, Palavit G). To evaluate water sorption and water solubility, thirty square-shaped specimens (20x20x1.5 mm) were fabricated from the wax specimens. One way ANOVA test, Tukey test and Pearson correlation coefficient performed for data. Results: Water sorption mean values varied from 11.33±0.33 to 30.46±0.55 µg/mm 3. Water solubility mean values varied from-0.05±0.23 to 3.69±0.12 µg/mm 3. There was statistically significant difference between mean values of the materials (P<.05). There was no linear correlation between sorption and solubility values. Conclusions: The results of the water sorption and water solubility values of both self-cured and heat-cured acrylic resins were in accordance with the ISO specification. No correlation found between water sorption and water solubility values. (Eur J Dent 2008;2:191-197
The effects of postural control to gender differences in children
Abstract The aim of this study was to compare the effects of gender differences on children’s static balance parameters. A total number of 60 children (girls group N=30, boys group N=30) aged 9-11 who had been never involved in any sport activities before, took part in this study voluntarily. Anthropometric measurements (height, weight) and bilateral, unilateral static balance tests were conducted on the both groups. For statistical comparison of the students, t test was used. When bilateral (EO, EC) and unilateral (left leg) static balance parameters of boys were compared to the balance parameters of girls, it was found statisticaly significant (p<0.05). No statistical differences were found for Romberg test (perimeter ratio, area ratio) and unilateral (right leg) static balance of the subjects between genders. (p>0.05). It was stated that 1) boys spend more time outside than the girls and that’s why their physical suitability was higher than the girls, 2) although they aren’t involved in any sport professionally, they play team games like soccer, basketball more than girls. It can be concluded that physical activity increases muscle strength of boys and affect their balance performance positively
Effects of Cornus mas L. and Morus rubra L. extracts on penicillin‑induced epileptiform activity: an electrophysiological and biochemical study
Traditionally, Morus rubra L. (Moraceae) (red mulberry) and Cornus mas L. (Cornacea) (cornelian cherry) fruits are eaten fresh and are also used in marmalades, juices, jam, natural dyes in Turkey and are believed to have beneficial effects in case of multiple health issues such as antipyretic, diarrhea and intestinal parasites. However, the effects of M. rubra and C. mas on epilepsy has not been known. This study evaluates the effects of M. rubra and C. mas extracts on penicillin‑induced epileptiform activity. Sixty Wistar rats randomly divided into ten groups (n=6): control, sham, penicillin, penicillin+M. rubra extract (2.5, 5, 10, 20 mg/kg) and penicillin+C. mas extract (2.5, 5, 10 mg/kg). Epileptiform activity was induced by using penicillin (500 IU, i.c.) and electrocorticogram records (150 min) were obtained. Also, biochemical analysis in blood samples were evaluated. According to the electrocorticogram analysis, the effective dose was detected as 10 mg/kg for both C. mas and M. rubra. This dose decreased the spike frequencies of convulsions while amplitude wasn't changed by both substances. In erythrocyte studies, there were significant differences regarding nitric oxide in the control, sham and penicillin groups. There were significant differences regarding malondialdehyde in all groups. In the plasma, there were significant differences among groups regarding xanthine oxidase in the penicillin‑C. mas and penicillin‑M. rubra groups. There were differences regarding malondialdehyde in the penicillin‑C. mas and M. rubra‑C. mas groups. Both extracts reduced the frequency of epileptiform activity. After administration of the extracts malondialdehyde levels decreased also in both erythrocytes and plasma
Effects of Cornus mas L. and Morus rubra L. extracts on penicillin‑induced epileptiform activity: an electrophysiological and biochemical study
Traditionally, Morus rubra L. (Moraceae) (red mulberry) and Cornus mas L. (Cornacea) (cornelian cherry) fruits are eaten fresh and are also used in marmalades, juices, jam, natural dyes in Turkey and are believed to have beneficial effects in case of multiple health issues such as antipyretic, diarrhea and intestinal parasites. However, the effects of M. rubra and C. mas on epilepsy has not been known. This study evaluates the effects of M. rubra and C. mas extracts on penicillin‑induced epileptiform activity. Sixty Wistar rats randomly divided into ten groups (n=6): control, sham, penicillin, penicillin+M. rubra extract (2.5, 5, 10, 20 mg/kg) and penicillin+C. mas extract (2.5, 5, 10 mg/kg). Epileptiform activity was induced by using penicillin (500 IU, i.c.) and electrocorticogram records (150 min) were obtained. Also, biochemical analysis in blood samples were evaluated. According to the electrocorticogram analysis, the effective dose was detected as 10 mg/kg for both C. mas and M. rubra. This dose decreased the spike frequencies of convulsions while amplitude wasn't changed by both substances. In erythrocyte studies, there were significant differences regarding nitric oxide in the control, sham and penicillin groups. There were significant differences regarding malondialdehyde in all groups. In the plasma, there were significant differences among groups regarding xanthine oxidase in the penicillin‑C. mas and penicillin‑M. rubra groups. There were differences regarding malondialdehyde in the penicillin‑C. mas and M. rubra‑C. mas groups. Both extracts reduced the frequency of epileptiform activity. After administration of the extracts malondialdehyde levels decreased also in both erythrocytes and plasma
Analysis of a novel four level flying capacitor h - bridge converter
WOS: 000429409200010In this paper, a novel four-level flying capacitor inverter and its comparison with the conventional flying capacitor topology in terms of THD analysis are proposed. This new topology have some advantages over conventional one as following: The blocking voltages are the same for all switches used in the configuration, there is no need for capacitor midpoint connection and this eliminates low frequency current which circulate in dc-link capacitors, and the number of flying capacitor is reduced as compared with conventional form of it. The operation of the topology, modulation strategy, simulation results, and THD analysis for the output waveforms are presented in this paper.Aksaray University [2016-031]This work has been supported by Research Fund of the Aksaray University. Project Number: 2016-031
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