7 research outputs found

    Digital PID Temperature Controlled Laminator Test Kit Design and Production for Small & Medium Scale Photovoltaic Module Production

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    In this study, laminator design and production are realized for small & medium scale photovoltaic (PV) module production. The reliability of the energy to be supplied by the PV modules and / or the system is possible by being durable against external conditions and long life. This can be ensured by the protection provided by industrially mandatory lamination techniques. For the aim of the study, first, the solid model of the system is created using the Solidworks® program and the system is simulated for optimum production conditions. After this step, the components of the designed system are identified and aluminium plates are produced in CNC and assembled on the chassis. The temperature control is provided by the PID controller while the desired thermal distribution for lamination of the PV module layers is provided by cartridge resistors. The upper aluminium sheet with flexible membrane for vacuum and / or pressure procedures required for the lamination of the PV module components is positioned on the slide rails. Following completion of the design and assembly, cell matrices are constructed by connecting solar cells in series and / or parallel, and the system is tested for industrial performance. As a result, the digital PID temperature-controlled laminator test kit for PV module production will provide insight into the lamination processes in existing technologies and ensure that students at undergraduate / graduate level have the necessary knowledge and experience

    Investigation of Hourly and Daily Patterns for Lithosphere-Ionosphere Coupling Before Strong Earthquakes

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    The ionosphere can be characterized with its electron density distribution which is a complex function of spatial and temporal variations, geomagnetic, solar and seismic activity. An important measurable quantity about the electron density is the Total Electron Content (TEC) which is proportional to the total number of electrons on a line crossing the atmosphere. TEC measurements enable monitoring variations in the space weather. Global Positioning System (GPS) and the network of world-wide receivers provide a cost-effective solution in estimating TEC over a significant proportion of global land mass. In this study, five earthquakes between 2003-2008 that occurred in Japan with different seismic properties, and the China earthquake in play 2008 are investigated. The TEC data set is investigated by using the Kullback-Leibler Divergence (KLI), Kullback-Leibler Distance (KLD) and L2-Norm (L2N) which are used for the first time in the literature in this context and Cross Correlation Function (CCF) which is used in the literature before for quiet day period (QDP), disturbed day period (DDP), periods of IS days before a strong earthquake (BE) and after the earthquake (AE). In summary, it is observed that the CCF, KLD and L2N between the neighbouring GPS stations cannot be used as a definitive earthquake precursor due to the complicated nature of earthquakes and various uncontrolled parameters that effect the behavior of TEC such as distance to the earthquake epicenter, distance between the stations, depth of the earthquake, strength of the earthquake and tectonic structure of the earthquake. KLD, KLI and L2N are used for the first time in literature for the investigation of earthquake precursor for the first time in literature and the extensive study results indicate that for more reliable estimates further space-time TEC analysis is necessary over a denser GPS network in the earthquake zones.Wo

    The effect of hydrogen sulfide on ischemi̇a /reperfusion injury in an experimental testicular torsion model

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    © 2021 Journal of Pediatric Urology CompanyIntroduction: Testicular torsion is an acute pediatric surgical emergency requiring rapid diagnosis to prevent the permanent ischaemic damage of the testicles. Hydrogen Sulfide (H2S) have shown to cure tissue damage and has a role in the prevention of I/R damage. We aimed to evaluate the effect of H2S in testicular torsion. Materials and methods: Eighteen male, Wistar albino rats were divided into 3 groups. The sham group which is applied surgical stress. The ischemia/reperfusion group (I/R) which detorsion performed 1 h later than testicular torsion application. I/R + NaHS treatment group, NaHS solution was injected intraperitoneally for 1 week. On the 7th day of the detorsion all left testes were fixed in Bouin solution and sent to Pathology Department for histopathological examination. All right testes were washed with normal saline, dried in a sterile way and stored in – 80 °C deepfreeze up to the date of biochemical processes. Testicular tissues were obtained for the detection of myeloperoxidase (MPO), malondialdehyde (MDA), AOPP (advanced oxidation protein product) for oxidant markers and ferric reducing antioxidant power (FRAP) levels, superoxide dismutase (SOD),glutathione peroxidase (GSH-Px) activities for antioxidant markers and histopathological exploration. Results: The effects of NaHs administration on oxidation were evaluated by determination of testicular MPO, MDA and AOPP levels. Increased testicular MPO (58.6%) activity was observed in the I/R group compared to the sham group. Following NaHS treatment, MPO (26.7%) activity was significantly decreased in rats exposed to I/R injury (Figure 1). MDA levels did not alter. Increases in AOPP (20.9%) levels were observed in the I/R group. NaHS treatment resulted in significant decreases in AOPP (25.1%) levels in testes tissues of rats exposed to I/R injury. The effects of NaHS treatment on antioxidant system FRAP, SOD, GSH and GSH-Px activities were evaluated. GSH levels were significantly increased in the IR + NaHS group compared to the I/R group. In histopathological examination degeneration of seminiferous tubules and spermatogenic cells were observed in the I/R group. After NaHS treatment, normal spermatogenic activity with many spermatozoa in the lumen of most seminiferous tubules were observed in the I/R injured rats. According to Johnsen's scoring (JS), the I/R group was significantly decreased compared to the sham group. JS values for the I/R + NaHS group were significantly increased compared to the I/R group. Conclusion: Our study supports that ischemia/reperfusion injury plays an important role in the testicular torsion injury, and it is a pioneer study showing that H₂S may have a potential for therapeutic effect. The limitation of this work is this is an experimental study with limited number of animals. According to the results of our study, hydrogen sulfide treatment has beneficial effects on biochemical and histopathological results of testicular injury in testic torsion

    Space Weather Studies Of Ionolab Group

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    IONOLAB is an interdisciplinary research group dedicated for handling the challenges of near earth environment on communication, positioning and remote sensing systems. IONOLAB group contributes to the space weather studies by developing state-of-the-art analysis and imaging techniques. On the website of IONOLAB group, www.ionolab.org, four unique space weather services, namely, IONOLAB-TEC, IRI-PLAS-2015, IRI-PLAS-MAP and IRI-PLAS-STEC, are provided in a user friendly graphical interface unit. Newly developed algorithm for ionospheric tomography, IONOLAB-CIT, provides not only 3-D electron density but also tracking of ionospheric state with high reliability and fidelity. The algorithm for ray tracing through ionosphere, IONOLAB-RAY, provides a simulation environment in all communication bands. The background ionosphere is generated in voxels where IRI-Plas electron density is used to obtain refractive index. One unique feature is the possible update of ionospheric state by insertion of Total Electron Content (TEC) values into IRI-Plas. Both ordinary and extraordinary paths can be traced with high ray and low ray scenarios for any desired date, time and transmitter location. 2-D regional interpolation and mapping algorithm, IONOLAB-MAP, is another tool of IONOLAB group where automatic TEC maps with Kriging algorithm are generated from GPS network with high spatio-temporal resolution. IONOLAB group continues its studies in all aspects of ionospheric and plasmaspheric signal propagation, imaging and mapping.Wo

    Investigation of Total Electron Content Variability Due to Seismic and Geomagnetic Disturbances in the Lonosphere

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    Variations in solar, geomagnetic, and seismic activity can cause deviations in the ionospheric plasma that can be detected as disturbances in both natural and man-made signals. Total electron content (TEC) is an efficient means for investigating the structure of the ionosphere by making use of GPS receivers. In this study, TEC data obtained for eight GPS stations are compared with each other using the cross-correlation coefficient (CC), symmetric Kullback-Leibler distance (KLD), and L2 norm (L2N) for quiet days of the ionosphere, during severe geomagnetic storms and strong earthquakes. It is observed that only KLD and L2N can differentiate the seismic activity from the geomagnetic disturbance and quiet ionosphere if the stations are in a radius of 340 km. When TEC for each station is compared with an average quiet day TEC for all periods using CC, KLD, and L2N, it is observed that, again, only KLD and L2N can distinguish the approaching seismicity for stations that are within 150 km radius to the epicenter. When the TEC of consecutive days for each station and for all periods are compared, it is observed that CC, KLD, and L2N methods are all successful in distinguishing the geomagnetic disturbances. Using sliding-window statistical analysis, moving averages of daily TEC with estimated variance bounds are also obtained for all stations and for all days of interest. When these bounds are compared with each other for all periods, it is observed that CC, KLD, and L2N are successful tools for detecting ionospheric disturbances.Wo
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