366 research outputs found
MOSFET-C-based grounded active inductors with electronically tunable properties
No full textYesil, Abdullah/0000-0002-0607-8226In this study, two new grounded metal oxide semiconductor field effect transistor (MOSFET)-C active inductors (AIs) are proposed. The proposed AIs contain only eight MOS transistors and a single grounded capacitor that is attractive for integrated circuit fabrication. Inductance values of them can be electronically tuned by a single control voltage. They do not include any current sources. Therefore, the designs of the proposed AIs are simple and useful. They do not suffer from body effects. Hence, they can be designed with low power supply voltages. Simulation results by using the Cadence analog environment program with 180 nm Taiwan Semiconductor Manufacturing Company (TSMC) nm technology parameters are carried out to indicate the performance of them. Layouts of both proposed AIs occupy the same area of about 78 mu m x 78 mu m. Postlayout simulation results are given to confirm the validity of the theoretical analysis
New simple transistor realizations of second‐ generation voltage conveyor
No full textYesil, Abdullah/0000-0002-0607-8226In this paper, two new complementary metal oxide semiconductor (CMOS) realizations for second-generation voltage conveyor (VCII) are presented. The first proposed VCII has a very simple structure employing only six transistors. The second proposed VCII employs 11 transistors, and none of the transistors at both proposed circuits suffer from the body effect. Small-signal analysis, parasitic elements, and input-referred noise of the proposed VCIIs are given. Moreover, a new active element called voltage controlled second-generation voltage conveyor (VC-VCII) is proposed as dual element of current controlled second-generation current conveyor (CCCII) active element. Its parasitic resistance at theYterminal can be controlled electronically. Two presented CMOS structures of VCII are worked as VC-VCII with slight modification. Proposed circuits are simulated in Cadence Analog environment using TSMC 0.18-mu m process parameters with +/- 0.9-V supply voltages. Both CMOS structures occupy a small chip area of 276.8 and 271 mu m(2), respectively. The bandwidth of the current follower stage of the proposed VCIIs is found as 794 MHz, whereas the bandwidth of the voltage follower stage for the first and second proposed VCIIs is found as 2.57 and 1.92 GHz, respectively. As an application example, voltage-mode first-order low-pass filter has been given with its tunable gain by using VC-VCII
The Impact of Climate Change on the Water Systems of the Yesil River Basin in Northern Kazakhstan
No full text[EN] The geographical location of Kazakhstan, situated in the central part of the Eurasian continent, has played a crucial role in shaping a distinctly continental climate. This positioning has led to Kazakhstan facing a signi¿cant challenge in terms of water resource availability. The country¿s water resources are highly vulnerable to the dual pressures of climate change and human activities. It is noteworthy that the Yesil River basin is the sole region within Kazakhstan¿s borders where water resources are predominantly generated, while all other river basins experience substantial out¿ows beyond the nation¿s boundaries. This research undertaking involves a comprehensive analysis of long-term climatic data collected from meteorological stations located within the con¿nes of the Yesil basin in Northern Kazakhstan. Additionally, the study encompasses the computation of water consumption and annual runoff within this region. Historical meteorological observations spanning from 1961 to 2020 reveal notable trends. Most signi¿cantly, a 1.2 ¿ C increase in temperature is observed during the spring season. Winters have also become relatively milder and warmer, particularly towards the end of February, where temperatures have shifted from ¿16.2 ¿ C in the ¿rst 30-year period to ¿14.6 ¿ C in the second period. These ¿ndings underscore the ongoing climatic changes within the region, with signi¿cant implications for the management and sustainability of water resources in Kazakhstan.This research work was funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan (Grant No. AP13268760).Kakabayev, AA.; Yessenzholov, B.; Khussainov, A.; Rodrigo-Ilarri, J.; Rodrigo-Clavero, M.; Kyzdarbekova, G.; Dankina, G. (2023). The Impact of Climate Change on the Water Systems of the Yesil River Basin in Northern Kazakhstan. Sustainability. 15(22):1-19. https://doi.org/10.3390/su152215745S119152
Application of HEC-RAS (2D) for Flood Hazard Maps Generation for Yesil (Ishim) River in Kazakhstan
No full textThe use of hydraulic models for carrying out flood simulations is a common practice globally. The current study used HEC-RAS (2D) in order to simulate different flood scenarios on the River Yesil (Ishim). Comparison of different mesh sizes (25, 50 and 75 m) indicated no significant difference in model performance. However, a significant difference was observed in simulation time. In addition, the inclusion of breaklines showed that there was a slight improvement in model performance and a shortening of the simulation time. Sensitivity analysis and the consequent manual calibration of sensitive parameters resulted in a slight improvement (an increase in the model accuracy from 58.4% for uncalibrated to 59.7% for calibrated). Following the simulations inundation maps for 10-, 20- and 100-year flood events were obtained. Hazard classification of the flood extents generated indicated that the settlements of Zhibek Zholy and Arnasay were flooded in all the simulated events. Volgodonovka village experienced flooding when a 100-year flood event was simulated. On the other hand, settlement No. 42 did not experience any flooding in any of the scenarios. The model results also demonstrate that the Counter-Regulator was not overtopped in the event of the 100-year hydrograph
Utilization of coordinating green solvents for high quality methylammonium bismuth iodide thin films for photovoltaic applications
No full textPhotovoltaic performances of the bismuth-based solar cells are profoundly affected by the thin film quality of the photoactive layer. Herein, we report on various green solvent system to obtain the highly crystalline, pinhole free and homogeneously methylammonium bismuth iodide (MBI) active layer. The MBI structure prepared with tetrahydrofuran:2-ethoxy-ethanol (THF-2ETO) solvent system was found to have the best film quality. Adding 0.05 M 2ETO as the co-solvent is sufficient to produce high quality BiI3 and MBI thin films. According to the Xray photoelectron spectroscopy (XPS) analyzes, we have demonstrated that there is an interaction between BiI3 and 2ETO according to the concentration of 2ETO added to the main THF. Our study clarifies the importance of THF-2ETO solvent system that can accelerate the evolution of the Bi-based solar cells by creating high-quality BiI3 or MBI thin films.Presidency of Turkish Republic Department of Strategy and Budget [2016K12-2841]; Scientific and Technical Research Council of Turkey (TUBITAK) [2211/C, 1649B031903340, 118Z948]Authors acknowledge to Presidency of Turkish Republic Department of Strategy and Budget for the financial support Project Grant Nr: 2016K12-2841 and Scientific and Technical Research Council of Turkey (TUBITAK) for financial support of A. MUTLU within the Program Nr.: 2211/C (Grant Nr.:1649B031903340) and for financial support of T. YESIL (Grant Nr.: 118Z948)
Flame Retarded Plasticized Poly(lactic Acid) Using Phosphorus-Based Additives
No full textIn this study, the synergistic effect of the flame-retardant additives on the properties of poly(lactic acid) (PLA) was investigated and at the same time, it was tried to increase the toughness of PLA by adding small amounts of phosphate-based additives to plasticized PLA as binary and ternary mixtures. Poly(ethylene glycol) (PEG) was used as a plasticizer. As flame retardant additives, ammonium polyphosphate (APP), tri-phenyl phosphate (TPP), and boron phosphate (BP) were used. Characterization of the composites was carried out by tensile test, impact test, differential scanning calorimetry (DSC), thermal gravimetric analyses (TGA), scanning electron microscopy (SEM), limiting oxygen index (LOI), and UL-94 horizontal burning tests. In addition, TGA-FTIR analyses were carried out to understand the thermal degradation mechanism of composites during combustion. According to the SEM micrographs of the burnt surfaces of the samples, a smooth and flat structure is observed in PLA/PEG/5TPP-5BP sample, while a porous structure and branching formations are observed in other composite samples. Among the composite samples, the best flame retardancy features were observed in the composite containing PLA/PEG/5APP-2.5TPP-2.5BP sample, and the highest impact strength and elongation at break values were obtained in the composite containing PLA/PEG/5APP-5TPP sample.Scientific and Technological Research Council of Turkiye (TUBITAK) [213M396]The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Sertan Yesil reports financial support was provided by The Scientific and Technological Research Council of Turkiye (TUBITAK) (Project No: 213M396)
Comparison of Psychometric Properties of the Dual-Task Timed Up-And Test (Cognitive) and the 3-M Walk Backward Test in Community-Dwelling Stroke Patients
No full textBaskan, Emre/0000-0001-7069-0658; Taskin, Gulsen/0000-0002-2016-4147; Yesil, Hilal/0000-0002-8291-1515; Eken, Fatma/0000-0003-2975-7480Background: There is a need for practical, easy-to-use and accurately assessing balance tools in stroke patients. Objectives: This study aimed to compare the psychometric properties of the dual-task Timed Up-and-Go test (cognitive) (DTUG) and the 3-m walk backward test (3MBWT) in stroke patients. Methods: This study evaluated the practicality, validity, and reliability of the DTUG and the 3MBWT. The test-retest method was used for reliability. The Modified Four Square Step Test (MFSST), the Timed Up-and-Go (TUG), and Berg Balance Scale (BBS) were administered for concurrent validity. A cutoff value was calculated to discriminate between fallers and non-fallers. Results: The mean practicality times of the tests were 63.58 +/- 47.32 sec for DTUG and 37.42 +/- 24.036 sec for 3MBWT. Intraclass correlation coefficient of the DTUG and 3MBWT were 0.977, 0.964, respectively which showed excellent test - retest reliability. The DTUG demonstrated strong/very strong correlations with the MFSST (r = 0.724, p 0.001), TUG (r = 0.909, p 0.001), and BBS (r = -0.740, p 0.001). The 3MBWT showed strong correlations with the MFSST (r = 0.835, p 0.001), the TUG (r = 0.799, p 0.001), and the BBS (r = -0.740, p 0.001). The cutoff point was 36.945 s for DTUG and 14.605 s for 3MBWT. Conclusions: The 3MBWT was a more practical test than the DTUG; however, the DTUG was more discriminative than the 3MBWT in identifying fallers after stroke
Glyptothorax armeniacus
No full textGlyptothorax armeniacus (Berg 1918) Glyptosternum armeniacum Berg 1918: 146. Type locality: Mukhlassi-darasi River, Upper Euphrates River system, Turkey. Syntypes: (5) ZMT (?4), ZSI [ex ZIN 20806] F11319/1 (1), ZIN 20806 (5, now 4). Distribution: Tigris and Euphrates basin, Turkey (Berg, 1918; Berg, 1931; Coad, 1979; Coad & Delmastro, 1985). Coad & Delmastro (1985) tentatively assigned a specimen from the Yesil Irmak, which is part of the Black Sea basin in Turkey, to this species.Published as part of Alfred W. Thomson & Lawrence M. Page, 2006, Genera of the Asian Catfish Families Sisoridae and Erethistidae (Teleostei: Siluriformes)., pp. 1-96 in Zootaxa 1345 on page 4
Floating Memristor Employing Single MO-OTA with Hard-Switching Behavior
No full text In this paper, we presented Multi-Output Operational Transconductance Amplifier (MO-OTA)-based floating memristor emulator circuit. The designed memristor circuit has only one MO-OTA and one grounded capacitor which is attractive for an integrated circuit. It does not consist of any multiplication circuit block to obtain nonlinear behavior of memristor. It is difficult to obtain the hard-switching voltage–current relationship than the smooth-switching voltage–current relationship of memristor but we obtained hard-switching voltage–current characteristics using single floating memristor circuit. The complete memristor circuit is laid by using Cadence Environment using TSMC 0.18[Formula: see text][Formula: see text]m process parameters. The layout area of MO-OTA occupies an area of 34[Formula: see text][Formula: see text]m [Formula: see text] 14[Formula: see text][Formula: see text]m. Its post-layout simulation results are given to demonstrate the performance of the presented memristor emulator in different operating frequencies, process corner and radical temperature changes. All post-layout simulations agree well with theoretical analyses. As application examples, different connections such as serial, parallel and single of memristor emulator are investigated to test its connectivity. </jats:p
Prevalence of metabolic dysfunction-associated fatty liver disease in kidney transplant recipients: A cross-sectional study using FibroScan
No full textBackground and Aim: Metabolic dysfunction-associated fatty liver disease (MAFLD) is expected to be prevalent among kidney transplant recipients (KTRs). In this study, we evaluated the prevalence of MAFLD among KTRs, data that have not been investigated by any clinical study to date. Materials and Methods: We included a total of 52 KTRs and 53 age-, sex-, and BMI-matched individuals as the control group through prospective consecutive recruitment. We detected the presence of hepatic steatosis and liver fibrosis using the controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) defined by FibroScan. Results: Among the KTRs, 18 (34.6%) had metabolic syndrome. The prevalence of MAFLD among the KTRs and controls was 42.3% and 51.9%, respectively (p=0.375). The CAP and LSM values did not differ significantly between the KTRs and controls (p=0.222 and p=0.119). Among the KTRs, patients with MAFLD had significantly higher age, p=0.011, p=0.033, p=0.022, and p=0.029, respectively). In multivariable analysis, age was the only independent factor for MAFLD among the KTRs (OR: 1.120, 95% confidence interval (CI): 1.039-1.208). Conclusion: MAFLD among KTRs did not show a significantly higher with larger populations are needed
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