23 research outputs found

    PID Control of Hybrid DC-DC Converter System in Complex Load with Double Reference Time

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    DC-DC converters are circuits that are widely used in energy distribution systems, in industry and technology applications, as well as in household appliances such as computers and televisions, and in uninterruptible power supplies used to feed all these systems. For the design and optimization of DC-DC converter circuits, it is important to create and analyze mathematical models according to the load it is connected to. Simple load structures and circuit structures have been examined and control units have been designed in studies carried out to date. In this study, while the DC-DC converter with a more complex load structure is discussed, mathematical analysis and PID control of DC-DC converters with Buck-Boost feature are performed with the same modulation index in different time periods. In the results obtained, it is shown how to create the mathematical models of a system that provides DC-DC energy conversion with a complex load structure and how to formulate the PID control in a system with this complex load structure

    Articaine versus lidocaine inferior alveolar nerve block in posterior mandible implant surgeries:a randomized controlled trial

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    The aim of this study is to compare the effects of %4 articaine and %2 lidocaine on inferior alveolar nerve block (IANB) for implant surgery in the posterior mandible. The patients who have inserted implants in the posterior mandible were divided into 2 groups for IANB: lidocaine and articaine. VAS = visual analog scale, pain during surgery and injection, lip numbness time, mandibular canal-implant apex distance, age, gender, bone density, implant number, release incision, adjacent teeth, and duration of surgery were analyzed using t-test, Mann-Whitney U test, Spearman's coefficient, and, Pearson's chi-squared test. This trial followed the recommendations of the Consort Statement for reporting randomized controlled trials. 577 patients were included and 1185 dental implants were analyzed. There was no significant difference between the two groups in terms of injection and surgery VAS values (p>0.05). The lip numbness time of lidocaine was 3.06±3.22min while articaine was found to be 2.96±3.09min (p>0.05). Mandibular canal-implant apex distance was found to be 2.28±0.75mm in the articaine and 2.45±0.86mm in the lidocaine group (p<0.05). Release incision was made more in the articaine group (51/252) than in the lidocaine group (40/325) (p<0.05). There was no difference between the %4 articaine and %2 lidocaine in terms of pain perception in posterior mandible implant applications. Both anesthetics provided adequate anesthesia for implant application

    LAMINATE VENEER - CAD / CAM: CASE REPORTS

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    ABSTRACTThe recent increase in the variety and functionality of materials and the innovations in the application techniques invigorated the conservative efforts within dental prosthetics to achieve natural looking aesthetic results. Porcelain laminate veneers are very effective tools in terms of both aesthetic and functional rehabilitation. This study narrates and explains the clinical application and cementation stages of porcelain laminate veneers techniques.Key words: Laminate veneer, zirconia, CAD-CA

    Farklı Akışkan Bulk Fill Kompozitlerin Mikrosertliklerinin Araştırılması

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    ÖzetAmaç: bu çalışma üç farklı bulk fill kompozit (Surefil SDR flow, Dentsply, Caulk, USA and Tetric, EvoCeram, Ivoclar Vivadent, Schaan, Liechtenstein, X-tra base, Voco, Cuxhaven, Germany) mikrosertliklerinin araştırılmasıdır.Gereç Yöntem: Çalışma için 4mm ve 2mm kalınlığında 4mm yarı çapında hazırlanan herbir bulk fill kompozit Plama ark ışık kayanağı kullanılarak polimerize edildi. Her bir örneğin alt ve üst mikrosertlik değerlendirmeleri Vickers mikrosertlik test cihazı kullanılarak yapıldıBulgular: çalışmada kullanılan tüm materyallerin polimerizasyonu ışık kaynağı ile yapıldıktan sonra alt yüzeylere ait sertlik değeri üst yüzeylerden daha düşük bulundu. Tüm komozitler arasında en yüksek Vickers sertlik değeri (40.02±4.06) olan grup üst Xtra base bulk fill kompozitine aitdir. En düşük Vickers sertlik değeri (5.80±0.83) alt ölçüm yapılan SDR bulk fill grubuna aittir.Sonuç: Tüm örnek gruplarına ait sertlik oranı 0.80 den daha düşük bulundu.örnek gruplarına ait sertlik oranı 0,19±0,3 ile 0,72±0,06 arasındadır.Anahtar kelimeler: mikrosertlik, akışkan kompositler, sertlik oran

    On the electrical and charge conduction properties of thermally evaporated MoOx on n- and p-type crystalline silicon

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    In this work, the electrical and charge conduction characteristics of a contact structure featuring thermally evaporated MoOx, deposited on n- and p-type crystalline silicon (c-Si), are extensively investigated by room temperature current-voltage (I-V), transmission line measurements (TLM), and temperaturedependent current-voltage measurements (I-V-T). XRD diffraction spectrum shows that the deposited MoOx film exhibits amorphous nature. From TLM measurements, the values of contact resistivity are calculated to be rho(c): 55.9 mXcm(2) for Ag/MoOx/n-Si and rho(c): 48.7 m Omega-cm(2) for Ag/MoOx/p-Si. The barrier parameters such as barrier height (phi(e)) and ideality factor (n) are investigated by the thermionic emission theory for I-V and I-V-T measurements. The phi(e), n, and conventional Richardson plot demonstrate resolute temperature dependency, obeying the barrier height of Gaussian distribution model. The uniform barrier height values are calculated to be phi(b):1.24 eV for Ag/MoOx/n-Si and /b:0.66 eV for Ag/MoOx/p-Si from the extrapolation of phi(e) at n = 1 of the linear fitting of the variation with the experimental barrier height phi(e)with ideality factor. The activation energy (Ea) and Richardson constant (A*), obtained from Richardson plot, are much smaller than phi(b) and the theoretical values of n- and p-type c-Si. The modified Richardson plot yields more reliable Richardson constant and homogeneous barrier height values of 106.2 Acm(-2) K-2 and 1.21 eV, 23.4 Acm(-2) K-2 and 0.63 eV for Ag/MoOx/n-Si and Ag/MoOx/p-Si heterostructures, respectively. The results demonstrate that thermally evaporated MoOx has particular advantages due to its good rectifying characteristics such as the extra enhancement to barrier height and low contact resistivity for interfacial layer applications
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