Browsing by Author "Tasci A.T."

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A study on nucleation, crystallization kinetics, microstructure and mechanical properties of Ru-Bi partial substituted BSCCO glass ceramics
(2016-02-01) Ozturk O.; Gokcen T.; Cavdar S.; Koralay H.; Tasci A.T.
This study deals with the effects of Ru-Bi partial substitutions on the thermal, structural and mechanical properties of Bi1.8-x Ru x Pb0.2Sr2CaCu2O10+δ (x = 0.0, 0.025, 0.050, 0.075) system, produced by using glass ceramics method. The effects of Ru-Bi partial substitutions on glass transition, nucleation and crystallization temperature were analyzed via differential thermal analyzer (DTA). Besides, microstructure and micromechanical properties of Ru-Bi partially substituted BSCCO glass ceramics were also investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Vickers microhardness measurements. From the DTA results, nucleation kinetics were studied by using Ozawa, Augis-Bennett, Takhor and Kissinger equations. In addition to this, activation energies and Avrami parameters were also calculated. According to the results of the thermogravimetric analyses, the amount of oxidation was seen to be increased with increasing Ru concentration. Moreover, the lattice parameters, volume fractions and surface morphologies of our newly produced glass ceramics were investigated by XRD and SEM measurements, respectively. RISE behavior obtained from the microhardness measurements for all samples. Microhardness, elastic modulus, yield strength and fracture toughness values decreased with increasing Ru doping.
Analyzing the anomalous dipole moment type couplings of heavy quarks with FCNC interactions at the CLIC
(2014-01-01) Tasci A.T.; Senol A.; Verep C.
We examine both anomalous magnetic and dipole moment type couplings of a heavy quark via its single production with subsequent dominant standard model decay modes at the compact linear collider (CLIC). The signal and background cross sections are analyzed for heavy quark masses 600 and 700 GeV. We make the analysis to delimitate these couplings as well as to find the attainable integrated luminosities for 3 σ observation limit. © 2014 A. T. Tasci et al.
Anomalous HZγ couplings in photon-induced collisions at the LHC
(2014-11-30) Senol A.; Tasci A.T.; Cakir I.T.; Cakir O.
We examined HZγ vertex and obtained the limits on anomalous aγ, bγ and bγ couplings in a model-independent way through the ?p collisions via the process pp → pγp → pHqX. The sensitivities to the anomalous couplings can be obtained as |bγ|, | bγ| 10-3 for the integrated luminosity of Lint = 100 fb-1 at the LHC with √s = 13 TeV.
Anomalous single production of fourth family up-type quark associated with neutral gauge bosons at the LHC
(2012-05-01) Çakr O.; Çakr I.T.; Senol A.; Tasci A.T.
The fourth family quarks are expected to have mass larger than the top quark considering the results from recent studies on the allowed parameter space. They could also have different dynamics than the quarks of three families of the standard model. The single production of the fourth family up-type quark t is studied via the anomalous production process pp → t′VX (where V = g, Z, γ) at the LHC with the center of mass energy of 7 and 14TeV. The signatures of such process are discussed within both the SM and the anomalous decay modes of t quarks. The sensitivity to anomalous coupling κ/Λ = 0.004TeV -1 can be reached at TeV and L int = 100 pb 1. © 2012 IOP Publishing Ltd.
Anomalous single production of fourth generation t' quarks at ILC and CLIC
(2011-10-11) Senol A.; Tasci A.T.; Ustabas F.
We present a detailed study of the anomalous single fourth generation t' quark production within the dominant Standard Model (SM) decay modes at future e+e- colliders. We calculate the signal and background cross sections in the mass range 300-800 GeV. We also discuss the limits of t'q' and t'qZ (q=u,c) anomalous couplings as well as values of attainable integrated luminosity for 3. σ observation limit. © 2011 Elsevier B.V.
Associated production of different flavor heavy quarks through W bosons at the LHC
(2013-02-01) Cakir I.T.; Senol A.; Tasci A.T.
Associated production of different flavor heavy quarks can provide a probe for W' bosons at the LHC. We study pp → t'b̄' X process with the subsequent decays t' → W+b and b̄' → W -W+b̄, and compare the results with the tb̄ final state. The effects of the W' boson to the different flavor pair production cross section are shown to be important in some parameter region for the heavy quark masses of 600 and 700 GeV. We present accessible mass limits for the W' boson at the LHC with √s = 14 TeV.
Associated production of single top quark and W boson through anomalous couplings at LHeC based γp colliders
(2014-02-10) Cakir I.T.; Senol A.; Tasci A.T.
We consider the production of a single top quark in association with a W boson at LHeC based γp collider. We compute the cross-section for the process γp→WtX with the anomalous Wtb and Wtbγ couplings. We find that the sensitivities to anomalous couplings of top quark are shown to be comparable, even better than the ones obtained from direct searches at hadron colliders. © 2014 World Scientific Publishing Company.
Experimental and theoretical approaches for magnetic, superconducting and structural characterization of Bi1.75Pb0.25Sr2Ca2Cu3-xSnxO10+y glass ceramics
(2017-12-01) Koralay H.; Cavdar S.; Arslan A.; Ozturk O.; Tasci A.T.; Tugluoglu N.
In this work, the effect of the partial substitution of Sn for Cu on structural, electrical and magnetic properties in the superconducting ceramic glass Bi1.75Pb0.25Sr2Ca2Cu3-xSnxO10+y system (x = 0, 0.1, 0.5) has been examined. The structural characterization of samples produced by glass-ceramic technique were done by X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements. The electrical and magnetic properties were determined by resistance-temperature (R-T) measurement and magnetization-magnetic field measurement (M-H) in the low temperature by using vibrating sample magnetometer (VSM), respectively. From the results of R-T measurement, the value of critical temperature (Tcoffset) has been decreased from 98 K to 73 K with increasing Sn- concentration. The critical current density has also been decreased with increasing magnetic field intensity. It has been observed from M-H plots that it was decreased with increasing the value of temperature. We have observed from M-H curves that the area size of the hysteresis curve decreases with increasing the value of temperature.
Probing anomalous hzz couplings at the lhec
(2013-10-10) Çakir I.T.; Çakir O.; Senol A.; Tasci A.T.
We examine the sensitivity to anomalous couplings of the Higgs boson to neutral gauge bosons in a model-independent way at the Large Hadron electron Collider (LHeC). We have obtained the constraints on anomalous couplings for HZZ vertex via the process e-p→e-HqX. We find the accessible limits on the CP-conserving coupling bZ as (-0.12,0.43) and (-0.10,0.33), while the limits on CP-violating coupling βZ as (-0.32,0.32) and (-0.24,0.24) at the electron beam energy Ee = 60 GeV and Ee = 140 GeV, respectively. © 2013 World Scientific Publishing Company. © World Scientific Publishing Company.
Search for anomalous WWγ and WWZ couplings with polarized E-beam at the LHeC
(2014-10-01) Cakir I.T.; Cakir O.; Senol A.; Tasci A.T.
We examine the possibility of constraining the anomalous WWγ and WWZ couplings by measuring total cross sections of the ep → νeqγX and ep → νeqZX processes at the LHeC collider with the electron beam energy Ee = 60 GeV and Ee = 140 GeV. We consider the cases of unpolarized and polarized electron beams. The difference of the upper and lower bounds on the anomalous couplings, (δ Δκγ,δλγ) and (δ Δκz,δλz) are obtained as (0:990, 0:122) and (0:362, 0:012) without electron beam polarization at the beam energy of Ee = 140 GeV for an integrated luminosity of Lint = 100 fb-1, respectively. With the possibility of e-beam polarization, we obtain more improved results as (0:975, 0:118) and (0:285, 0:009) for (δ Δκγ,δλγ) and (δ Δκz,δλz), respectively. The results are found to be comparable with the current experimental limits obtained from two-parameter fits to the data collected in the lepton and hadron colliders. It is found that the limits on the anomalous couplings (Δκz,δλz) through the process ep → νeqZX at the LHeC can further improve the current experimental limits.
Search for top quark FCNC couplings in Z'models at the LHC and CLIC
(2010-11-01) Çakir O.; Çakir I.T.; Senol A.; Tasci A.T.
The top quark is the heaviest particle to date discovered, with a mass close to the electroweak symmetry breaking scale. It is expected that the top quark would be sensitive to the new physics at the TeV scale. One of the most important aspects of the top quark physics can be the investigation of the possible anomalous couplings. Here, we study the top quark flavor changing neutral current (FCNC) couplings via the extra gauge boson Z' at the Large Hadron Collider (LHC) and the Compact Linear Collider (CLIC) energies. We calculate the total cross sections for the signal and the corresponding Standard Model (SM) background processes. For an FCNC mixing parameter x=0.2 and the sequential Z' mass of 1 TeV, we find the single top quark FCNC production cross sections 0.38(1.76) fb at the LHC with Spp= 7(14)TeV, respectively. For the resonance production of sequential Z′ boson and decays to single top quark at the Compact Linear Collider (CLIC) energies, including the initial state radiation and beamstrahlung effects, we find the cross section to be 27.96(0.91) fb at Se+e- = 1(3) TeV, respectively. We make the analysis to investigate the parameter space (mixing-mass) through various Z′ models. It is shown that the results benefit from the flavor tagging. © 2010 Springer-Verlag / Società Italiana di Fisica.
Searching for Single Production of Charged Heavy Leptons via Anomalous Interactions at CLIC
(2013-01-01) Tasci A.T.; Senol A.
We consider the possible discovery potential for single production of charged heavy leptons via anomalous interactions at the envisaged compact linear collider by taking into account initial state radiation and beamstrahlung effects. We calculate the production cross sections and decay widths of charged heavy leptons in the context of anomalous interactions at center of mass energies √s = 1 and 3 TeV. The signal and corresponding backgrounds are studied in detail for the mass range 300-1900 GeV. © 2012 King Fahd University of Petroleum and Minerals.
Single production of fourth-family t′ quarks at the CERN large hadron electron collider
(2009-11-09) Cakir O.; Senol A.; Tasci A.T.
We study the electroweak single production of fourth-family t′ quarks via the process ep→t′ν at the Large Hadron electron Collider (LHeC). We calculate the background and signal cross-sections for the mass range 300-800 GeV. It is shown that the LHeC can discover a single t′ quark up to the mass of 750 GeV for the optimized mixing parameters. Copyright © 2009 EPLA.
Solar light performances of n-ZnO nanorods/p-Si-based photodetectors under high illumination intensity
(2022-06-01) Ozturk O.; Candan B.M.; Kurnaz S.; Cicek O.; Tasci A.T.
We present ZnO nanorod/ZnO thin film structures synthesized at different molarities and growth times using a hydrothermal method, exhibiting uniquely solar sensing characteristics. ZnO thin film was deposited on p-Si(100) substrate by using RF sputter. ZnO nanorods with different molarities (10 and 20 mM) and growth times (2, 3, and 4 h) were fabricated at 90 °C by using the hydrothermal method on the n-ZnO/p-Si. The surface texture was also examined by scanning electron microscopy. The diameter of ZnO NRs was in the range of 62–119 nm. The current–time measurements were done under solar light illumination intensity (50 and 100 mW/cm2) and forward bias voltage (1, 5, and 10 V). Decay time (τd), rise time (τr), detectivity (D*), responsivity (R), and sensitivity (S) parameters were calculated. Samples produced at 2 h and 3 h in 10 mM solution performed best due to low τd, τr, and high D*, R, S. Especially, the S for the PD102 changed from 4.24 to 11.8, while it was in the range of 0.41–7.33 for the PD103. The R was 5.81 AW−1 in PD102 and 1.19 AW−1 in PD103. The D* was 109–1011 cmHz1/2/W in PD102 and 1010–1011 cmHz1/2/W in PD103 at ± 6 V.
Structural and mechanical characterization of Bi1.75Pb 0.25Sr2Ca2Cu3-xSnxO 10+y superconductor ceramics using Vickers microhardness test
(2013-11-01) Koralay H.; Arslan A.; Cavdar S.; Ozturk O.; Asikuzun E.; Gunen A.; Tasci A.T.
In this work we investigated the role of Sn doping on mechanical and structural properties of Bi1.75Pb0.25Sr2Ca 2Cu3-xSnxO10+y (x = 0.0, 0.1, 0.3 and 0.5) superconducting ceramic material. All samples were fabricated with glass ceramic method. The prepared samples were characterized by using scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), X-ray powder diffractometer (XRD) and static microhardness indenter. Surface morphology, orientation of grains, and elemental composition analysis of the samples were made by SEM and EDS measurements, respectively. Texturing and lattice parameters a and c were determined by XRD measurements. Load dependent and load independent microhardness, elastic modulus, yield strength and fracture toughness were obtained by hardness measurements. In this work we focused on Vickers microhardness measurements in order to characterize the mechanical properties of our samples. Experimental results of Vickers microhardness measurements were analyzed by using Meyer's law, the elastic/plastic deformation model, proportional sample resistance model (PSR), modified PSR model and Hays-Kendall (HK) approach. From these analyses, HK approach was determined as the most successful model describing the mechanical properties of our samples. Finally in this study, the changes on the mechanical and microstructural properties of Sn doped Bi-2223 superconductors and their possible reasons were also discussed in detail. © 2013 Springer Science+Business Media New York.
The Effect of Zinc on the Structural, Electrical, and Mechanical Properties of YBCO-123 Superconducting Nanoparticles Prepared by an Acetate-Based Sol-Gel Process
(2019-11-01) Asikuzun E.; Ozturk O.; Aydemir G.A.; Tasci A.T.
In this study, zinc (Zn)-doped YBaCuO (YBCO)-123-based high-temperature superconducting samples were produced using the sol-gel method, which is commonly used for preparing nanosize materials. Zn ions were substituted by Cu ions (YBa2Cu3-xZnxO), and Zn doping effects on structural, electrical, and mechanical properties of the YBCO-123 superconductors were examined in detail. Undoped sample was prepared under same conditions. X-ray diffraction analysis (XRD) was used to determine phase analysis and lattice parameters of the superconducting samples. To analyze the microstructure properties, scanning electron microscope (SEM) measurements were performed. Resistivity and microhardness measurements were also carried out for superconducting and mechanic properties, respectively. Vickers microhardness, young modulus, fracture toughness, and yield strength values of the samples were calculated. Microhardness measurements were analyzed using the Kick’s law, proportional sample resistance (PSR) model, EPD model, the Hays-Kendall (HK) approach, and indentation-induced cracking (IIC) model.