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Öğe 106Sg, 107Bh and 108Hs çekirdekleri için Alfa Bozunum Enerjilerinin Belirlenmesi(2016) Akkoyun, Serkan; Bayram, TuncayHem teorik hem de deneysel bakış açısıyla, super ağır bölgenin özelliklerini anlamak için, buradaki çekirdeklerin alfa bozunum özelliklerini incelemek oldukça ilgi çekicidir. Nükleer fizikteki pek çok olguda başarılı sonuçlar veren yapay sinir ağları (YSA), super ağır çekirdeklerin deneysel alfa bozunum enerjileri üzerinde kullanılmış ve Sg, Bh ve Hs çekirdeklerinin alfa bozunum enerjileri bu yöntemle tahmin edilmiştir. Farklı modeldeki YSA'lar veriler üzerinde test edilmiştir. Bu çalışmanın sonuçları, YSA metodunun bu iş için uygun olduğunu göstermektedir. Sonuçlara ait ortalama kare hatalar, ½1-1,5 civarındadır. En iyi sonuçlar, bulanık mantık YSA modeli ile elde edilmiştirÖğe 116,117,118,119,120,124Sn ve233,234,235,236,238U İzotopları İçin Dev Dipol RezonansEnerjilerinin Kestirimi(2017) Akkoyun, Serkan; Bayram, Tuncay; Özgüven, YücelDev dipol rezonans (GDR) parametrelerini elde etmek için birçok deneysel ve teorik metot uygulanmaktadır.Bu çalışmada, Sn ve U izotopları için GDR enerjileri, yapay sinir ağları (YSA) metodu ile tahmin edilmiştir. Sonuçlara göre, YSA'nın eğitiminde deneysel verilerden ortalama sapma, %1 seviyesindedir. Sn ve U izotopları için tahmin edilen enerjilerdeki ortalama kare hata, 0,034 MeV'dir.Teorik bir model için ise hata, 0,061 MeV'dir.Bu sonuç, GDR enerjileri üzerinde ANN tahmininin, teorik hesaplamalardaki sonuçlardan daha iyi olduğunu göstermektedir.Öğe A Computer Program for Calculation of Approximate Embryo/Fetus Radiation Dose in Nuclear Medicine Applications(Galenos Publ House, 2012) Bayram, Tuncay; Sonmez, BircanObjective: In this study, we aimed to make a computer program that calculates approximate radiation dose received by embryo/fetus in nuclear medicine applications. Material and Methods: Radiation dose values per MBq-1 received by embryo/fetus in nuclear medicine applications were gathered from literature for various stages of pregnancy. These values were embedded in the computer code, which was written in Fortran 90 program language. Results: The computer program called nmfdose covers almost all radiopharmaceuticals used in nuclear medicine applications. Approximate radiation dose received by embryo/fetus can be calculated easily at a few steps using this computer program. Conclusion: Although there are some constraints on using the program for some special cases, nmfdose is useful and it provides practical solution for calculation of approximate dose to embryo/fetus in nuclear medicine applications.Öğe A Microscopic Analysis on Shape of Ruthenium Isotopes(Romanian Journal of Physics, 2013) Bayram, Tuncay[Abstract Not Available]Öğe A study on ground-state energies of nuclei by using neural networks(Pergamon-Elsevier Science Ltd, 2014) Bayram, Tuncay; Akkoyun, Serkan; Kara, S. OkanOne of the fundamental ground-state properties of nuclei is binding energy. Artificial neural networks (ANN) have been performed to obtain binding energies of nuclei based on the data calculated from Hartree-Fock-Bogolibov method with two Skyrme forces SLy4 and SKP. ANN has been employed to obtain two-neutron and two-proton separation energies of nuclei. Statistical modeling of ground-state energies using ANN has been seen as to be successful in this study. Particularly, predictive power of ANN has been drawn from estimations for energies of Sr, Xe, Er and Pb isotopic chains which are not seen before by the network. The study shows that such a statistical model can be possible tool for searching in systematic of nuclei beyond existing experimental data. (C) 2013 Elsevier Ltd. All rights reserved.Öğe A study on structural evolution of 142-164Nd isotopes(Journal of Physics: Conference Series, 2014) Kara, Seyit Okan; Bayram, Tuncay; Akkoyun, SerkanConstrained Hartree-Fock-Bogoliubov theory with SLy5 Skyrme force has been applied for even-even 142-164Nd isotopes to investigate the structural evolution of Nd isotopic chain. In this work, ground-state energies and charge radii of Nd isotopes have been carried out as in good agreement with the experimental data. The systematic investigation of ground-state shape evolution between spherical U(5) and axially deformed SU(3) for 142-164Nd has been studied by using potential energy curves.Öğe An analysis of E(5) shape phase transitions in Cr isotopes with covariant density functional theory(Iop Publishing Ltd, 2013) Bayram, Tuncay; Akkoyun, SerkanConstrained relativistic mean field theory (RMF) has been employed for analysis of the shape phase transitions of even-even Cr52-66 isotopes. The systematic investigation of ground-state shape evolution between spherical U(5) and gamma-unstable O(6) for these nuclei has been carried out by using the potential energy curves (PECs) obtained from the effective interactions NL3*, TM1, PK1 and DD-ME2. The calculated PECs have indicated that Cr-58 can be a candidate for the critical-point nucleus with E(5) symmetry. A similar conclusion is also drawn from the calculated single-particle spectra of Cr-58 and is supported by the experimental data via observed ratios of the excitation energies. Furthermore, the gamma-independent character of Cr-58 has been pointed out by using its binding energy map in the beta-gamma plane obtained from the triaxial RMF calculations, in agreement with the condition of E(5) symmetry.Öğe An approach to adjustment of relativistic mean field model parameters(E D P Sciences, 2017) Bayram, Tuncay; Akkoyun, SerkanThe Relativistic Mean Field (RMF) model with a small number of adjusted parameters is powerful tool for correct predictions of various ground-state nuclear properties of nuclei. Its success for describing nuclear properties of nuclei is directly related with adjustment of its parameters by using experimental data. In the present study, the Artificial Neural Network (ANN) method which mimics brain functionality has been employed for improvement of the RMF model parameters. In particular, the understanding capability of the ANN method for relations between the RMF model parameters and their predictions for binding energies (BEs) of Ni-58 and Pb-208 have been found in agreement with the literature values.Öğe An investigation of gamma ray mass attenuation from 80.1 to 834.86 keV for fabric coating pastes used in textile sector(Springer Singapore Pte Ltd, 2020) Erenler, Alev; Bayram, Tuncay; Demirel, Yusuf; Cengiz, Erhan; Bayrak, RizaIn the present study, we investigate several textile coating pastes used in the market based on their radiation protection capability for gamma rays. The gamma ray mass absorption coefficients of some coating pastes doped with antimony, boron and silver elements have been investigated. It has been determined that the gamma ray mass attenuation coefficient decreases rapidly as the energy of the gamma rays increases. It was determined that the doping of the main printing paste with silver and antimony considerably increased the gamma ray absorption capability of main paste. However, the doping of the paste with boron reduces the mass absorption of gamma rays. In particular, the gamma ray mass absorption power of the main paste doped with silver and antimony was determined to be useful in the gamma energy range from 80 to 140 keV. This indicates that the newly doped textile material may be considered for radiation protection in the case of low-energy gamma rays .Öğe AN INVESTIGATION ON SHAPE EVOLUTION OF Ti ISOTOPES WITH HARTREE-FOCK-BOGOLIUBOV THEORY(World Scientific Publ Co Pte Ltd, 2012) Bayram, TuncayConstrained Hartree-Fock-Bogoliubov theory with SLy4 and SLy5 Skyrme forces is used to investigate the shape transition between spherical and gamma-unstable nuclei in Ti38-66. by examining potential energy curves and neutron single-particle levels of even-even Ti isotopes, Ti-46,Ti-52,Ti-60 are suggested as possible candidates of the nuclei with E(5) symmetry.Öğe Axially Deformed Relativistic Mean Field Calculations On The Properties Of Isotopic Chain Of Super-Heavy Hs Nuclei(Balkan Physics Letters, 2011) Yılmaz, Ahmet Hakan; Bayram, TuncayAt present many laboratories in the field of nuclear physics study on the Super-Heavy Nuclei (SHN) because the successful synthesizing of super-heavy elements (SHE) in lab has stimulated the research. This speeds up the researches on SHN theoretically. There are some theor etical studies on the Super-Heavy Nuclei based on the self-consistent mean field models. In this study, the structures of the Super-Heavy Hs nuclei for a wide range of neutron numbers were investigated using the deformed relativistic mean field (RMF) theory with new Lagrangian parameters set. Binding energy, quadrupole moment, deformation parameter, neutron radii, proton radii, two-neutron separation energy, ?-decay energy and ?-decay half-lives of Hs isotopes were calculated. The results were compared with available experimental data and predictions of some nuclear models. The results show that RMF theory with newly revised NL3* parameters set yields successful description for ground-state properties of isotopic chains of super-heavy Hs nuclei.Öğe Calculation of Fission Barrier of 230-234Pa Isotopes(Azerbaijan Journal of Physics - Fizika, 2010) Yılmaz, Ahmet Hakan; Engin, B.; Bayram, Tuncay; Demirci, M.The fission barriers of 230-234Pa have been carried out by using the BARRIER code developed by Garcia. The nuclear shape has been parameterized in terms of Cassini ovaloids proposed by Pashkevich. The single- particle energies have been calculated as function of the deformation parameters of an axially deformed Woods-Saxon potential, as input to the shell correction calculations. To obtain the total nuclear energy, it is also necessary to add a pairing energy in order to take into consideration the short range nuclear interactions.Öğe ?-decay half-life calculations of superheavy nuclei using artificial neural networks(Journal of Physics: Conference Series, 2014) Bayram, Tuncay; Akkoyun, Serkan; Kara, Seyit OkanInvestigations of superheavy elements (SHE) have received much attention in the last two decades, due to the successful syntheses of SHE. In particular, ?-decay of SHEs has a great importance because most synthesized SHE have a-decay and the experimentalists have evaluated the theoretical predictions of the a-decay half-life during the experimental design. Because of this, the correct prediction of ?-decay half-life is important to investigate superheavy nuclei as well as heavy nuclei. In this work, artificial neural networks (ANN) have been employed on experimental a-decay half-lives of superheavy nuclei. Statistical modeling of a-decay half-life of superheavy nuclei have been found as to be successful.Öğe Deforme 166Gd Çekirdeğinde Sözdespin Çiftlerinin Özellikleri(Cumhuriyet Üniversitesi Fen Bilimleri Dergisi, 2012) Bayram, Tuncay; Yılmaz, A. HakanSözdespin simetrisi küresel çekirdeklerde elli yıl kadar önce gözlendi. Uzun yıllar orijini anlaşılamayan bu simetrinin on yıl kadar önce çekirdek içerisinde eşit büyüklükte ancak zıt işaretli çekici skaler ve itici vektör potansiyeller varlığında ortaya çıktığı anlaşıldı. Bu durum yaklaşık bir biçimde bu tür potansiyelleri içeren ve çekirdeklerin birçok taban-durum özelliklerinin ortaya çıkarılmasında başarılı bir biçimde kullanılan relativistik ortalama alan (RMF) teorisinin sözdespin simetrisi incelemelerinde kullanılmasını mümkün kılmaktadır. Bu simetri çerçevesinde tek-parçacık enerji seviyelerinin kuantum sayılarına göre yerleşimlerinin gösterimi klasik gösterimden farklılık göstermektedir. Bu bağlamda sözdespin simetrisi çerçevesinde tek-parçacık enerji seviyelerinin çekirdek deformasyonuna bağlı olarak değişiminin incelenmesi ilginç olabilir. Bu nedenle bu çalışmada RMF teorisi çerçevesinde deforme olduğu deneysel olarak iyi bilinen 166Gd çekirdeğinin nötron ve proton tek-parçacık enerji seviyelerindeki sözdespin çiftlerinin kuadrupol deformasyon parametresine göre değişimleri incelendi. Ayrıca sözdespin kavramı ve RMF teorisi detaylıca irdelendi.Öğe Energy level and half-life determinations from photonuclear reaction on Ga target(World Scientific Publ Co Pte Ltd, 2016) Akkoyun, Serkan; Bayram, Tuncay; Dulger, Fatih; Dapo, Haris; Boztosun, IsmailPhotonuclear reactions are important tools in the understanding of the nucleus. These reactions are also interesting for realizing the element creation processes in stellar environment. The use of bremsstrahlung photons generated from clinic linear accelerator is practical for performing these type of reactions. In this study, the bremsstrahlung photons with endpoint energy of 18 MeV have been used for activating gallium target material. After irradiation, the transition energies and half-lives associated with the decay of Ga-68, Ga-70 and Ga-72 isotopes have been determined The values obtained for half-life of Ga-68, Ga-70 and Ga-72 isotopes are 67.5 +/- 0.9 min, 21.1 +/- 0.9 min and 13.8 +/- 0.4 h, respectively. It has been seen that the values are consistent with the present literature values. In addition, the new measurements of gamma-ray energies for transition energies have been obtained comparable to the literature values with good uncertainties.Öğe Estimations of beta-decay energies through the nuclidic chart by using neural network(Pergamon-Elsevier Science Ltd, 2014) Akkoyun, Serkan; Bayram, Tuncay; Turker, TugbaOne of the main characteristics of unstable nuclei is beta-decay energy (Q(beta)). It is determined by different methods such as beta endpoint measurements, counting in coincidence with annihilation radiation, electron capture (EC)/beta(+) ratio method, method of gamma absorption with X-ray coincidence. Beta-decay energy is a roughly linear function of atomic and mass numbers. Due to the fact that artificial neural network (ANN) is sufficient for nonlinear function approximation, in this study by using the nuclear masses from Hartree-Fock-BCS method, Q(beta) values have been obtained by ANN. It is seen that the estimations of the ANN are consistent with the calculated data within some deviation. (C) 2013 Elsevier Ltd. All rights reserved.Öğe Estimations of fission barrier heights for Ra, Ac, Rf and Db nuclei by neural networks(World Scientific Publ Co Pte Ltd, 2014) Akkoyun, Serkan; Bayram, TuncayAccurate information about the fission barrier is important for studying of the fission process. Fission barrier is needed for discovering the island of stability in superheavy region and searching of the superheavy elements. Furthermore, the astrophysical r-process is closely related to the fission barrier of the neutron-rich nuclei. In this study, by using artificial neural network (ANN) method, we have estimated the fission barrier heights of the Rf, Db, Ra and Ac nuclei covering 230 isotopes. For inner barrier calculation, we have used Rf and Db nuclei and the barrier heights have been determined between nearly 1 MeV and 7 MeV. The related mean square error value has been obtained as 0.108 MeV. For outer barrier calculation, we have used Ra and Ac nuclei and the heights have been determined between nearly 8 MeV and 28 MeV. The related mean square error has been obtained as 0.407. The results of this study indicate that ANN is capable for the estimations of inner and outer fission barrier heights.Öğe Ground State Nuclear Properties of Some Rare Earth Nuclei in Relativistic Mean Field Theory(Azerbaijan Journal of Physics - Fizika, 2010) Yılmaz, Ahmet Hakan; Bayram, Tuncay; Demirci, M.; Engin, B.In this study, rare earth nuclei, 160Gd, 168Er , 170Er and isotopic chain of Dy were investigated using relativistic mean field theory with non-linear NL3 and NLSH parameters sets. Binding energies per nucleon, neutron radii, proton radii, charge radii, neutron and proton quadrupole moments of these nuclei were calculated. Also, these ground state properties were calculated using non-relativistic Hartree-Fock-Bogoliubov method with parameters set SKP. Predictions of this work were compared with available experimental data and some predictions calculated with different parameters set in relativistic mean field theory.Öğe Ground State Nuclear Propertıes Of Mo And Ru Isotopes In Skyrme-Hartree-Fock-Bogolıubov Method(Balkan Physics Letters, 2011) Bayram, Tuncay; Yılmaz, Ahmet Hakan; Engin, B.; Demirci, M.Ground-state nuclear properties of Mo and Ru isotopes were studied within the Hartree-Fock-Bogoliubov method with SL y4 and SL y5 Skyrme forces. Nuclei which have neutron numbers close to magic number 50 have received much attention because the nuclei are known well deformed and exhibit anomalous behaviour in the isotope shifts. Therefore, a systematic study of even-even Mo and Ru isotopes was carried out. Almost all ground-state properties which include binding energy per nucleon, quadrupole deformation, nuclear radii, two -neutron separation energyand shape-coexistence for axially deformed Mo and Ru isotopes were analyzed. The results were compared with available experimental data and predictions of some nuclear models (Finite Range Liquid-Drop Model (FRDM), Extended Thomas Fermi Model with Strutinski Integral (ETF-SI) and Relativistic Mean Field (RMF) Theory) and discussed in detail. The results show that the HFB method with SLy4 and SL y5 Skyrme forces is capable of describing of isotopic chain of even-even Mo and Ru nuclei.Öğe Ground-State Properties of Axially Deformed Sr Isotopes in Skyrme-Hartree-Fock-Bogoliubov Method(Azerbaijan Journal of Physics - Fizika, 2010) Yılmaz, Ahmet Hakan; Bayram, Tuncay; Demirci, M.; Engin, B.Binding energies, the mean-square nuclear radii, neutron radii, quadrupole moments and deformation parameters to axially deformed Strontium isotopes were evaluated using Hartree-Fock-Bogoliubov method. Shape coexistence was also discussed. The results were compared with experimental data and some estimates obtained within some nuclear models. The calculations were performed for Sly4 set of Skyrme forces and for a wide range of the neutron numbers of Sr isotopes.
