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Öğe Compliance with General Rules and Periodically Differences During the COVID-19 Pandemic in Türkiye: A Cross-Sectional Study(Turkiye Klinikleri, 2022) Şahin, İ.; Toluk, Ö.; Uzunoğlu, A.; Yabacı, Tak, A.; Ercan, İsmailObjective: The aim of this research is to investigate the compliance of the society with the general 14 rules of the Ministry of Health and the generally accepted hygiene rules recommended in the literature during the coronavirus disease-2019 (COVID-19) pandemic process. In line with the purpose, behavioral differences related to demographic characteristics and pandemic periods were also evaluated. Material and Methods: The study was conducted in August 2021 and snowball sampling technique was used. A questionnaire of 23 questions was applied to participants, in which compliance with the hygiene rules, including demographic questions, was investigated. The study included 1,069 participants between the ages of 18 and 65, living in Türkiye, using smartphones. Results: In our study, when the results of the compliance with the measures are examined, the compliance has decreased in almost all the other periods compared to the first period of the pandemic. In general, females pay more attention to complying with hygiene rules than males. It has been observed that those who have had COVID-19 disease pay less attention to participating in public areas than those who have not had COVID-19 disease. Conclusion: Social distancing, avoidance of mass events, hygiene, etc., are the most criti-cal measures in slowing the spread of coronavirus. For this reason, it should not be forgotten that non-compliance with the rules will lead to an increase in cases. In terms of the “normalization” steps taken during the pandemic process, analyzing the compliance rate with the hygiene rules seems very important in guiding future studies. © 2022, Turkiye Klinikleri. All rights reserved.Öğe Concentration effect of Cadmium Selenide Sulphide/Zinc Sulphide quantum dots on electro-optic and dielectric properties in nematic liquid crystals composite(Elsevier Science Bv, 2018) Kocakülah, Gülsüm; Önsal, Gülnur; Gökşen, Kadir; Ercan, İsmail; Köysal, OğuzIn this work, we have studied concentration effect of Cadmium Selenide Sulphide/Zinc Sulphide (CdSeS/ZnS) quantum dots (QDs) dispersed on liquid crystalline material, 4-penty1-4'-cyanobiphenyl nematic liquid crystal (5CB NLC). We used the dielectric spectroscopy technique to obtain electrical and dielectric properties for pure 5CB and doped with QDs form. To observe the effect of CdSeS/ZnS QDs concentration, 5CB was dispersed with 0.05, 0.1 and 0.15% wt/wt CdSeS/ZnS QDs. Some physical parameters such as real part of dielectric permittivity (epsilon'), imaginary part of dielectric permittivity (epsilon ''), loss tangent (tan delta), dielectric anisotropy (Delta epsilon') and ac conductivity (sigma(ac)) of pure 5CB NLC and CdSeS/ZnS QDs doped 5CB NLC composite were measured in the frequency range of 1 kHz-10 MHz at various bias voltages by using dielectric spectroscopy technique at room temperature. In addition, the threshold voltage (V-th) and splay elastic constant (K-11) parameters were calculated dependent on doping concentration. The current-voltage (I-V) characteristics of the samples were also in vestigated. The results showed that the electro-optic and dielectric parameters change significantly with CdSeS/ZnS QDs doping and which were explained by the molecular interaction mechanism between LC molecules and CdSeS/ZnS QDs.Öğe The effects of Zn/Fe co-dopants on the structural, thermal, magnetic, and in vitro biocompatibility properties of calcium pyrophosphate ceramics(Elsevier, 2022) Kebiroğlu, Hanifi; Ateş, Tankut; Bulut, Niyazi; Ercan, İsmail; Ercan, Filiz; Açarı, İdil Karaca; Köytepe, SüleymanIn the present work, calcium pyrophosphate (CPP) samples co-doped with Zn and Fe were prepared by using a wet chemical method, and their thermal, magnetic, structural, morphologic, and in vitro biocompatibility properties were investigated for the first time. X-ray diffraction (XRD) results showed that a continuous decreasing trend in two lattice parameters, unit cell volume, and average crystallite size was observed with the increasing Zn content. Zn content affected the magnetic and thermal behaviors, cell viability property of the CPP, as well as morphology. The sample containing 0.22 at.% Zn and 0.22 at.% Fe showed the best biocompatibility among all the samples, and the higher amount of Zn caused the lower cell viability. The bandgap of the CPP decreased with adding of Zn, while the linear absorption coefficient value increased.Öğe Enhanced photocatalytic degradation of methylene blue by nanocomposites prepared by laser ablation of Bi on CNT-a-Fe2O3 nanoparticles(Elsevier Sci Ltd, 2022) Manda, Abdullah A.; Elsayed, Khaled; Gaya, Umar İbrahim; Haladu, Shamsuddeen A.; Ercan, İsmail; Ercan, Filiz; Alheshibri, MuidhThe low conductivity and high combination rate of photogenerated electrons (e-) and photogenerated holes (h+) are the real challenges of photocatalysis. These problems could be mitigated by the synthesis of heterostructured nanocomposites (NCs). In this study, Bi@CNT-Fe2O3 nanocomposite was fabricated via pulsed laser ablation in liquid and characterized by UV-Vis spectroscopy, photoluminescence (PL), X-ray diffraction (PXRD) and field scanning electron microscopy (FESEM). These techniques revealed successfully the formation of CNT-alpha-Fe2O3 and Bi@CNT-alpha-Fe2O3 nanocomposites. The photocatalytic activities of the Fe2O3, CNT-alpha-Fe2O3, and Bi@CNT-Fe2O3 photocatalysts were evaluated by the degradation of methylene blue (MB) dye under ultraviolet (UV) light irradiation in the presence of a very low concentration of hydrogen peroxide (H2O2) as an oxidizing agent. The results show that the Bi@CNT-alpha-Fe2O3 NC has the highest photocatalytic degradation efficiency of MB which completes in 20 min of UV light irradiation. In addition, the obtained rate constants (min-1) of Bi@CNT-alpha-Fe2O3 NC were 1.3 and 3.4 times higher than those of CNT-alpha-Fe(2)O(3 )and alpha-Fe2O3. nanocatalysts, respectively.Öğe GÜÇ SİSTEMLERİNDE HARMONİKLERİN KRİTİK DEĞERLERE ETKİSİ(Düzce Üniversitesi, 2016) Alaşahan, Yusuf; Ercan, İsmail; Öztürk, Ali; Tosun, SalihGünümüz dünyasında gelişen teknoloji ile birlikte her geçen gün insan hayatına yeni cihazlar girmektedir. Bunun sonucunda ise enerji ihtiyacı gerek bireysel gerekse endüstriyel olarak artmaktadır. Bu artış “Enerji Kalitesi” kavramını ortaya çıkarmıştır. Enerji kalitesini etkileyen unsurlardan biri de “Harmonikler”dir. Bu çalışmada “Güç Sisteminin Kritik Değerleri” dediğimiz, sistemde taşınacak maksimum güç ve sistemin kritik gerilim değerlerine harmoniklerin etkisi incelenecektir. Bu kapsamda örnek bir sistemde Harmonik Güç Akışı yapılacak; sonra da bu işlemin sonucunda bulunacak olan sistemdeki baralara ait aktif ve reaktif güç değerleri ile gerilim genlik ve faz açısı değerleri kullanılarak elde edilen PV eğrisi üzerinden sistemde harmonik bileşenlerin olması halinde kritik değerlerdeki değişim hakkında bir yargıya varılacaktır.Öğe Photoconductivity kinetics in AgIn5S8 thin films(Elsevier Science Sa, 2010) Qasrawi, A.F.; Kayed, Tarek S.; Ercan, İsmailThe temperature (T) and illumination intensity (F) effects on the photoconductivity of as grown and heat-treated AgIn5S8 thin films has been investigated. At fixed illumination intensity, in the temperature region of 40-300K, the photocurrent (I-ph) of the films was observed to decrease with decreasing temperature. The I-ph of the as grown sample behaved abnormally in the temperature region of 170-180K. At fixed temperature and variable illumination intensity, the photocurrent of the as grown sample exhibited linear, sublinear and supralinear recombination mechanisms at 300 K and in the regions of 160-260K and 25-130 K. respectively. This behavior is attributed to the exchange of role between the linear recombination at the surface near room temperature and trapping centers in the film which become dominant as temperature decreases. Annealing the sample at 350 K for 1 h improved the characteristic curves of I-ph. The abnormality disappeared and the I-ph - T dependence is systematic. The data analysis of which revealed two recombination centers located at 66 and 16 meV. In addition, the sublinear recombination mechanism disappeared and the heat-treated films exhibited supralinear recombination in most of the studied temperature range. (C) 2010 Elsevier B.V. All rights reserved.Öğe Structural, optical and photocatalytic properties of cerium doped Ba2TiMoO6 double perovskite(Elsevier B.V., 2023) Ghrib, Taher; Al-Otaibi, A.; Ercan, F.; Manda, Abdullah A.; Özçelik, Beraat; Ercan, İsmailCe doped Ba2TiMoO6 nanomaterials with different Ce concentrations were synthesized by solid state technique. It was determined by the XRPD method that the atomic and molecular structures of Ba2Ti1-xCexMoO6 [x=(1,3,5,7)%] compound was in the tetragonal crystal system and crystallized in the P4mm space group. The purification parameters were found to be gof 1.2 and Rf 1.60. The Scanning Electron Microscopy, Transmission Electron Microscopy, and surface area analysis were used to examine the surface morphology. The UV–Vis diffuse reflectance and photoluminescence spectroscopies were used to investigate the optical properties. The study results showed the successful synthesis of pure and Ce doped Ba2TiMoO6 nanopowders, characterized by 8–20 nm grain size, 3.41–3.6 eV bandgap, and violet emission at 426.67 nm wavelength. The photocatalytic activities of the produced samples were tested against Methyl and it was observed that these activity values increased with the percentage of Ce doping. © 2022 Elsevier B.V.Öğe Structural, optical, and electrical properties of Zn(1-x)MgxO nano-compounds and ZnO/Zn(1-x)MgxO heterostructures(Elsevier Science Sa, 2022) Ercan, Filiz; Alamroo, Nabilah; Ghrib, Taher; Kayed, Tarek; Özçelik, Bekir; Ercan, İsmail; Alonizan, NorahIn this study, the structural, thermal, optical, electrical and magnetic properties of Zn(1-x)MgxO (x = 0.0, 0.1, 0.3, 0.5) nano-compounds obtained by the addition of MgO to pure ZnO nano-compounds obtained by solid state reaction were investigated in detail. These nanomaterials were deposited by spin coating technique in hetero-structure of ZnO/Zn(1-x)MgxO. It was found by detailed structure solution that the crystal systems of nano materials obtained with MgO additive remained hexagonal, but the space group was transferred from P63mc to P6/mmm. The thermal gravimetry analysis shows the stability of prepared nanomaterials, the UV-Vis spectroscopy shows that the bandgap of the prepared was decreased from 3.02 to 2.52 eV with the Mg doping percentage. The Magnetization measurements at room temperature showed that all four of these Zn(1-x)MgxO nanostructures exhibited soft ferromagnetic behavior. The analysis of the ZnO/Zn(1-x)MgxO heterostructure showed that its band gap was increased from 3.69 to 3.79 eV, its carrier density was decreased from 1.14 x 10(19) to 4.20 x 10(13 )cm(-3) which introduce it as a good material to be used in optoelectronic devices field.Öğe Structural, Optical, Dielectric and Magnetic Properties of Double Perovskite Oxides A(2)FeTiO(6) (A = Zn, Mg, Cu) Nanopowders(Springer Heidelberg, 2022) Ghrib, Taher; Ercan, Filiz; Kayed, T. S.; Flemban, Tahani H.; Yıldız, Mesut; Kaygılı, Ömer; Ercan, İsmailThe investigation of structural, microstructural, optical, dielectric, and magnetic properties of double perovskite materials Zn2FeTiO6 (M1), Mg2FeTiO6 (M2), and Cu2FeTiO6 (M3) synthesized by solid-state reaction was reported in this work. The three compounds crystalized in a monoclinic structure with the space group of P12(1)/c. The microstructure of M1, M2, M3 samples was scanned by SEM to show the crystallinity in shape, and elemental mappings from EDX confirmed the consistency with sample concentrations. Similar spectra were observed from the FTIR technique. The diffused reflectance in the 200-800 nm wavelength range and photoluminescence for the samples were measured to investigate the optical properties. Dielectric constants, conductivity, frequency dependence of the tangent loss (tan delta), AC conductivity at different dc bias voltages, and the electric modulus M(omega) were examined to ensure the potential of the examined materials for microelectronic applications in circuit devices.Öğe Structure and thermal decomposition of mu-1,1-azido bridged dinuclear Fe(III) complexes(Oldenbourg Verlag, 2007) Ercan, Filiz; Ateş, B. Meltem; Aksu, Levent; Sözeri, Hüseyin; Ercan, İsmail; Atakol, OrhanFe(III) complexes were prepared by the reaction of two different ONNO type Schiff bases N,N'-bis (salicylidene)-1,3-propanediamine (LH2) and N,N'-bis (salicylidene)-2,2'-dimethyl-1,3-propane diamine (LDMH2) in N-3(-) containing medium. The X-ray diffraction studies revealed that the complexes are of dinuclear type connected with mu-1,1-azido bridges. It was observed from the thermogravimetric analyses of the complexes that the azide group decomposed around 200 degrees C with exothermic reaction. This exothermic decomposition did not affect the rest of the molecule. Following the decomposition of the azide group the remainder of the molecule decomposed with carbonization process. It was seen that the molecule decomposed into Fe2O3 above 650 degrees C in oxygen containing medium. [FeLDMN3](2) complex was found to have N4O2 distorted octahedral sphere with Fe...Fe distance of 3.414 angstrom.Öğe Synthesis of Ag nanoparticles-decorated on CNTs/TiO2 nanocomposite as efficient photocatalysts via nanosecond pulsed laser ablation(Elsevier Sci Ltd, 2022) Alheshibri, Muidh; Elsayed, Khaled; Haladu, Shamsuddeen A.; Magami, Saminu Musa; Al Baroot, Abbad; Ercan, İsmail; Ercan, FilizA simple, reproducible, and non-surfactant self-templating approach was developed for the synthesis of silver nanoparticles decorated on CNTs/TiO2 nanocomposite via a nanosecond pulsed laser ablation method. In addition, the effective use of the resulting nanocatalysts was carried out in the enhanced photocatalytic degradation of methylene blue dye contaminant. Following the synthesis of the nanocomposite catalysts, their morphology, heterostructure, and the nature of incorporation of their constituents were confirmed by TEM and SEM microscopy. In addition, characteristic diffraction patterns of the materials were studied by XRD powder diffraction method, confirming the crystalline nature of the nanocatalysts. The photoluminescence (PL) analysis provided information about the surface defects present as well as the electron-hole recombination properties of the prepared nanocatalysts. Despite the poor ultraviolet light absorption of the neat CNT and the TiO2 constituents beyond 400 nm, an efficient ultraviolet light-induced photodegradation of the methylene blue dye was successfully achieved. In this, by carrying out 50 min of ultraviolet light irradiation of the dye in the presence of the TiO2/CNT and the Ag/TiO2/CNT nanocomposite catalysts, 89.8% and 96 % reduction efficiencies were achieved, respectively. The experimental error associated with the photodegradation efficiency was within +/- 3%. The ultraviolet light-induced catalytic degradation of the dye follows first-order reaction kinetics, with rate constants of 3.95 x10-2 min-1 and 4.56 x 10-2 min-1 associated with the TiO2/CNT and the Ag/TiO2/CN catalyzed reactions, respectively.
