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Öğe A Density Functional Theory study for adsorption and sensing of 5-Fluo-rouracil on Ni-doped boron nitride nanotube(Elsevier, 2021) Yüksel, Numan; Köse, Ahmet; Fellah, Mehmet FerdiIn this research, the use of Ni-doped (8,0) boron nitride nanotube (Ni-BNNT) as both a sensor and an adsorbent for 5-Fluorouracil (5-FU) molecule was investigated by Density Functional Theory (DFT) method. The B3LYP method with 6-31G(d,p) basis set have been utilized. Six different adsorption configurations have been studied theoretically. After 5-FU adsorption on Ni-BNNT, the adsorption energy values were calculated as negative values in all configurations. Adsorption energy (Delta E) value and adsorption enthalpy (Delta H) value reached 0.75 eV and -0.78 eV values, respectively. Moreover, Gibbs free energy changes were computed to be negative values in all configurations and thus it was determined that the process could occur spontaneously. Charge transfer occurred between all configurations of Ni-BNNT and the 5-FU molecule. The HOMO-LUMO gap decreased in the NiN-BNNT (Ni-doped instead of N) structure, while it increased in the Ni-B-BNNT (Ni-doped instead of B) structure. The Ni-BNNT structure assistances from a recovery time as a sensor for 5-FU drug molecule. Moreover, the workfunction change occurred somewhat in all configurations, but it was calculated that there was more change (16.22%) in the NiN-O1-BNNT configuration. In addition, solvent (water) effect was also examined. Consequently, Ni-doped (8,0) BNNT structure can be used as both a sensor and an adsorbent for 5-FU molecule at room temperature.Öğe A Density Functional Theory study of molecular hydrogen adsorption on Mg site in OFF type zeolite cluster(Pergamon-Elsevier Science Ltd, 2020) Yüksel, Numan; Köse, Ahmet; Fellah, Mehmet FerdiIn this study, hydrogen molecule adsorption was investigated on additional framework of Mg atom in OFF type zeolite by way of DFT (Density Functional Theory). The adsorption enthalpy and adsorption energy, chemical potential, HOMO energy, electronegativity, LUMO energy, chemical hardness values have been computed on a 8T zeolite cluster model and compared with those of Mg exchanged ERI, LTL and DFT zeolite structures previously reported in literature. Hydrogen adsorption enthalpy value was computed as -17 kJ/mol. This value is meaningfully larger than the hydrogen molecule's liquefaction enthalpy value. This accordingly specifies that Mg-OFF zeolite structure appears to be an encouraging candidate cryoadsorbent for hydrogen storing. (c) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Öğe A Density Functional Theory Study on Rechargeable Mg-ion Batteries: C20 Fullerene as a Promising Anode Material(Wiley, 2022) Köse, Ahmet; Yüksel, Numan; Fellah, Mehmet FerdiIn this study, the applicability of C-20 fullerene as anode material in Mg-ion batteries was investigated by Density Functional Theory (DFT). The interaction energy of the Mg2+ ion on C-20 structure was found as -147.3 kcal/mol. The HOMO-LUMO gap value decreased during Mg interaction on C-20 structure while it increased during Mg2+ interaction. The charge distributions obtained after the interactions of Mg atoms on C-20 show that charge transfer has taken place. The storage capacity value of C-20 structure was calculated to be 893 mAhg(-1). The diffusion barrier was calculated as 1.9 kcal/mol. In addition, the diffusion coefficient for Mg and Mg2+ on C-20 structure were computed as 1.5x10(-25) and 4.61x10(-4), respectively. Consequently, the high storage capacity, high conductivity and low diffusion barrier for discharge/charge process and the suitability of the diffusion coefficient suggest that C-20 fullerene structure can be used as a potential anode material in rechargeable Mg-ion batteries.Öğe A DFT investigation of hydrogen adsorption and storage properties of Mg decorated IRMOF-16 structure(ELSEVIER, 2022) Yüksel, Numan; Köse, Ahmet; Fellah, Mehmet FerdiHerein, the hydrogen storage property of the Mg decorated isoreticular metal organic framework-16 (IRMOF-16) is investigated by Density Functional Theory (DFT) method. The WB97XD hybrid method (including dispersion) was used for hydrogen adsorption on Mg decorated IRMOF-16 structure. It was determined that the adsorption enthalpy for the structure was negative (-4.2 kJ/mol) at room temperature and thus it could be a potential adsorbent material for the hydrogen. The gravimetric hydrogen storage capacity of the IRMOF-16 structure decorated with four Mg atoms was determined as ~5.8 wt%. According to the electronic properties, it was revealed that the Mg-IRMOF-16 structure could not be used as an electronic sensor against the hydrogen molecule.Öğe Density functional theory study of ?-lactam anti-biotics (penicillin, floxacillin and ampicillin) detection and adsorption onto calix[4]arene(2025) Yüksel, NumanIn this work, the adsorption and sensing behavior of a calixarene macrocycle toward three ?-lactam anti-biotics was probed by density functional theory (DFT). All calculations were carried out with the B3LYP hybrid functional using the 6-31G(d,p) basis set. The simulations demonstrate that the calix[4]arene scaffold exhibits a pronounced sensing response exclusively for floxacillin: its sensor response factor is roughly six orders of magnitude greater than those obtained for ampicillin and penicillin. Additionally, analysis of frontier orbitals shows a 16.4% contraction of the HOMO–LUMO gap upon floxacillin binding, a perturbation that is visually evident in the density of states profile. Taken together, these findings establish calix[4]arene as a viable electronic sensor for floxacillin under ambient conditions.Öğe Host-guest complex properties of calix[4]arene derivatives: a DFT study of adsorption and sensing of an anticancer drug, 5-fluorouracil(Springer Wien, 2021) Yüksel, Numan; Fellah, Mehmet FerdiIn this study, it has been reported the host-guest complex properties of calix[4]arene compounds (the 3rd generation supramolecule) against the 5-fluorouracil (5-FU) anticancer drug by density functional theory calculations at room temperature. The B3LYP hybrid method was used to determine the optimized structures of the host and guest molecules and their complexes. The adsorption energy changes of the complexes formed between calix[4]arene compounds and 5-FU drug were calculated to be negative values. The strongest interaction was determined for the water-soluble calix[4]arene compound with sulfonyl (-SO3H) groups (Delta E = - 98 kJ/mol and Delta H = - 100.5 kJ/mol). Moreover, it was determined that HOMO-LUMO gaps of all calix[4]arene compounds decreased. The charge transfer has occurred between the four calix[4]arene compounds and the drug molecule. The work function values of calix[4]arene compounds have been changed. These results indicate that calix[4]arene derivatives can be used as well-suited 5-FU sensor at room temperature. Solvent effect calculations have stated that the interaction of 5-FU molecule with the calix[4]arene compound with sulfonyl (-SO3H) groups weakens and the Delta E becomes less negative value (- 71.6 kJ/mol). [GRAPHICS] .Öğe Hydrogen adsorption on Ni doped carbon nanocone(ELSEVIER SCIENCE SA, 2022) Köse, Ahmet; Yüksel, Numan; Fellah, Mehmet FerdiHydrogen adsorption was investigated on Ni doped carbon nanocone (Ni-CNC) 180 degrees C by Density Functional Theory (DFT). The WB97XD method was used with the 6-31G(d,p) and LanL2DZ basis sets. The electronegativity, HOMO and LUMO energies, chemical hardness, chemical potential, adsorption enthalpy and adsorption energy values have been calculated for hydrogen adsorption on Ni-CNC structure. The adsorption enthalpy value of hydrogen molecule was calculated as-27.8 kJ/mol. According to the storage capacity study for the Ni-CNC structure, it was found that this structure adsorbed eight hydrogen molecules and the hydrogen storage capacity was calculated to be similar to 4.3 wt%. After hydrogen adsorption, there was no significant decrease in HOMO-LUMO gap value. In addition, this situation indicates that the electrical conductivity of the Ni-CNC structure does not increase. These results show that the Ni-CNC structure cannot be used as a sensor for the hydrogen molecule, but it is a promising candidate material for hydrogen storage at room temperature.Öğe Metal-kaliks[4]aren komplekslerinin hidrojen adsorplama ve algılama özelliklerinin yoğunluk fonksiyoneli teorisi (DFT) ile incelenmesi(Bursa Teknik Üniversitesi, Lisansüstü Eğitim Enstitüsü, 2024) Yüksel, Numan; Fellah, Mehmet FerdiHidrojen yüksek ısıl değere sahip ve çevreyi kirletmeyen bir yakıt türüdür. Bu nedenle hidrojene olan ilgi günümüzde artmaktadır. Ancak hidrojen enerjisi üzerinde yapılan çalışmalar içerisindeki en önemli sorun hidrojenin güvenli depolanmasıdır. Hidrojenin gaz veya sıvı olarak depolanmasının çok ciddi dezavantajları vardır. Bu nedenle hidrojenin bir maddeye adsorplanarak depolanması önemli bir alternatif çalışma olarak görülmektedir. Son yıllarda, hidrojen adsorpsiyonu ve algılaması çalışmalarında metalo-organik komplekslere oldukça ilgi duyulmaktadır. Makrosiklik organik bileşiklerin metal kompleksleri üzerinde araştırmalar giderek artmaktadır. Çok çeşitli türevlendirilebilme özelliğine sahip olan kaliksaren makrosikliklerin hidrojen adsorpsiyon ve algılama çalışmaları yok denecek kadar azdır. Tez kapsamında yapılan bu çalışmada, adsorplanması veya algılanması istenilen analitin yapısı ile etkileşime girebilecek fonksiyonel gruplar ile kolaylıkla türevlendirilebilen kaliksaren bileşiklerinin hidrojen molekülünün adsorpsiyonunda ve algılanmasında kullanılabilecekleri gösterilmiştir. Tez çalışmasında Gaussian09 yazılımı kullanılarak DFT hesaplamaları gerçekleştirilmiştir. DFT hesaplamalarında wB97XD hibrit metodu, ve 6-31G(d,p)/LANL2DZ temel setleri kullanılmıştır. Çalışmada, temel kaliks[4]aren bileşiği olan p-tert-bütilkaliks[4]aren bileşiği ve ondan türetilen dört farklı yapılara sahip türevleri kullanılmıştır. Bu yapıların Cu, Fe, Ni ve Zn metal atomlarıyla kompleks oluşumları gerçekleştirilmiş ve hidrojen adsorpsiyon çalışmaları yürütülmüştür. En düşük adsorpsiyon enerji değerlerine sahip olan yapı C4-Cuhalka kompleks yapısı olarak belirlenmiştir. Bu kompleksin hidrojen molekülüne karşı adsorpsiyon enerji ve adsorpsiyon entalpi değerleri sırasıyla, -26,1 ve -28,6 kJ/mol olarak hesaplanmıştır. RDG analizlerine göre tüm adsorpsiyon proseslerinde van der Waals etkileşimleri baskındır. Yapıların H2 molekülüne karşı elektronik özellikleri incelendiğinde, C3-Fealt kompleksinin HOMO-LUMO band boşluğunda -78 kJ/mol'lük azalma meydana gelmiş, buna bağlı olarak elektriksel iletkenliğinde artma meydana gelmiştir. Ayrıca, en yüksek sensör tepki faktörü ve sensörün iş fonksiyonundaki en fazla değişime sahip yapı da C3-Fealt kompleksi olmuştur. Dolayısyla bu kompleks için oda sıcaklığında H2 sensörü olarak kullanılabileceği ortaya çıkmıştır. En iyi adsorpsiyon performansı gösteren C4-Cuhalka kompleksi üzerinde hidrojen depolama çalışmaları gerçekleştirilmiştir. 26 H2 molekülü adsorbe edebilen C4-Cuhalka kompleksinin gravimetrik hidrojen depolama kapasitesi %4,7 olarak hesaplanmıştır. Moleküler Dinamik hesaplamaları ile hem C3-Fealt kompleksi hem de C4-Cuhalka kompleksinin, çalışma sıcaklığında dinamik kararlılığını sürdürdükleri gözlemlenmiştir. Son olarak, hem hidrojen sensörü hem de hidrojen depolama malzemesi adayı olan C3-Fealt ve C4-Cuhalka komplekslerinin hidrojen molekülü ile etkileşimi, pertürbasyon analizi ile incelenmiş ve etkileşimde en yüksek stabilizasyon enerjilerine sahip atomlar belirlenmiştir. Gelecekte, bu çok yönlü makrosikliklerin farklı türevleri ile metal kompleks oluşumları incelenmeli ve güvenli hidrojen depolama malzemeleri olarak araştırma sayıları artırılmalıdr.Öğe Metal-Porphyrin Complexes: A DFT Study of Hydrogen Adsorption and Storage(Koray SAYIN, 2022) Köse, Ahmet; Yüksel, Numan; Fellah, Mehmet FerdiIt has been performed hydrogen adsorption on four metallo-porphyrin complexes by Density Functional Theory (DFT) calculations at room temperature. The WB97XD hybrid formalism method was used for hydrogen adsorption on metallo-porphyrin complexes formed with alkaline metal and alkaline earth metal (Na, K, Mg and Ca) atoms. It was determined that the adsorption energies for all complexes were negative, so that each of them could be a potential adsorbent for hydrogen storage. The adsorption enthalpy (?H) was calculated as -21.9 kJ/mol for the Na-Porphyrin (Na-P) complex structure. Moreover, the gravimetric hydrogen storage capacity for the Na-P complex was calculated to be ?5.5 wt%. Thus, the DOE's target for 2025 has been achieved. In addition, van der Waals weak interactions were found to be effective in hydrogen adsorption and storage studies. Based on the electronic properties the metallo-porphyrin complexes could not be used as electronic sensors against the hydrogen molecule.Öğe Methyl-mercaptane adsorption and sensing on Fe-/Co-graphene structures: A DFT study(DergiPark, 2021) Yüksel, Numan; Köse, Ahmet; Fellah, Mehmet FerdiIn this research, the adsorption and detection abilities of Fe and Co doped graphene structures for methyl-mercaptan molecule were investigated by Density Functional Theory (DFT) method. B3LYP hybrid functional and LANL2DZ/6-31G(d, p) basis sets were used in the calculations. At the end of the adsorption processes, Fe and Co doped graphene structures were determined to be suitable adsorbents for the methyl-mercaptan molecule. In addition, charge transfer happened from the methyl-mercaptan molecule to the Fe and Co-doped graphene structures. The electronic sensor and the Φ-type sensor properties were also investigated and it was determined that Fe-graphene structure could be only used as an electronic sensor for methyl-mercaptan molecule at room temperature.Öğe Pd, Ag and Rh doped (8,0) single-walled carbon nanotubes (SWCNTs): A DFT study on furan adsorption and detection(Elsevier, 2021) Yüksel, Numan; Köse, Ahmet; Fellah, Mehmet FerdiIn this study, the use of single-walled carbon nanotubes (SWCNTs) with doping Pd, Ag and Rh as both a sensor and an adsorbent for furan molecule was investigated by Density Functional Theory (DFT) method. The WB97XD method with 6-31G(d,p)/LanL2DZ basis sets have been utilized in theoretical calculations. The charge distribution indicates that the charge transfer happened (as an electron accepting system) from the adsorbed furan molecule to the Pd, Ag and Rh atoms of SWCNT structures. The HOMO-LUMO gaps of the Pd, Ag and Rh doped carbon nanotubes decreased slightly with adsorption of furan molecule. The electrical conductivities of Pd, Ag and Rh doped (8,0) SWCNT clusters increased somewhat after a furan molecule adsorption. Furthermore, adsorption enthalpies (-49.6 kJ/mol, -62.9 kJ/mol and -64.3 kJ/mol, respectively) of furan molecule adsorption on Pd, Ag and Rh doped (8,0) SWCNTs show that these materials have the ability to adsorb furan molecule. Consequently, Pd, Ag and Rh-doped SWCNTs might be used as both sensors and adsorbents for furan molecule at room temperature.Öğe The supramolecularly complexes of calix[4]arene derivatives toward favipiravir antiviral drug (used to treatment of COVID-19): a DFT study on the geometry optimization, electronic structure and infrared spectroscopy of adsorption and sensing(Springer Science and Business Media B.V., 2021) Yüksel, Numan; Köse, Ahmet; Fellah, Mehmet FerdiWhile the world is in search of a vaccine that can cure COVID-19 disease, favipiravir is the most commonly used antiviral drug in the treatment of patients during the pandemic process. In this study, we investigated the host–guest interaction between the popular supramolecule calix[4]arene derivatives and the favipiravir drug by using the DFT (Density Functional Theory) method. The B3LYP hybrid method and 6-31G (d,p) basis set were utilized to determine the optimized structures of the host and guest molecules and their complexes. The negative adsorption energy (∆E) and adsorption enthalpy (∆H) calculated for the complexes formed between calix[4]arene compounds and favipiravir drug molecule mentioned that adsorption of favipiravir molecule was an exothermic process on calix[4]arene structures. On the other hand, among the calixarene derivatives in the study, Gibbs free energy change (∆G) value for the adsorption was only negative on calix[4]arene4 molecule. The infrared spectroscopy (IR) calculations were performed by examining the C=O, O–H and NH2 vibrational frequencies to see the adsorption behavior in the favipiravir-calix[4]arene complex. After adsorption of the favipiravir molecule, HOMO–LUMO gap values decreased significantly for the structures and therefore electrical conductivity increased proportionally. In addition, sensor response factors, Fermi energy levels and workfunction changes of calix[4]arene derivatives were calculated and examined. Charge transfer between the four calix[4]arene compounds and the favipiravir molecule has occurred after adsorption. This attributes that calix[4]arene derivatives can be used as a well-suited favipiravir sensor (electronic and workfunction) and adsorbent at room temperature. Based on the calculations made to see the solvent effect on the adsorption of favipiravir it was determined that it did not affect the interaction between the drug molecule and the calix[4]arene compound too much and the adsorption energy turned into a slightly less negative value.Öğe The thermal analysis of paraffin wax in a box-type solar cooker(Amer Inst Physics, 2012) Yüksel, Numan; Arabacigil, Bihter; Avci, AtakanIn this study, the potential use and effectiveness of paraffin wax in solar cooker during the daylight and/or late evening hours is experimentally investigated. For these experiments, a box-type solar cooker was constructed by filling paraffin wax with metal shavings. The side-and sub-surface temperatures of the paraffin wax in the cooker are continuously measured during June and July 2011. The effect of the reflector angle on the thermal efficiency of the cooker is tested with different isolation conditions on different days. In conclusion, the designed cooker can be effectively used at an angle of 30 degrees. The thermal efficiency is increased to around 18.35% with the reflector. The maximum temperature of the paraffin achieved during the experiments is in the range of 75.1 degrees C to 80.5 degrees C. The reflected radiation makes a maximum contribution of 13.29% to the temperature of the paraffin wax. In addition, the heating time is decreased to approximately 1 h. So, the paraffin wax could be used as a phase change material integrated with the solar system. The rectangular solar cooker filled with the paraffin wax has a high thermal performance, which is indicated by high temperatures and decreased cooking times, for the given design conditions. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4768547]Öğe THE USE OF PARAFFIN WAX IN A NEW SOLAR COOKER WITH INNER AND OUTER REFLECTORS(Vinca Inst Nuclear Sci, 2015) Arabacigil, Bihter; Yüksel, Numan; Avci, AtakanThe potential use and effectiveness of paraffin wax in a new solar cooker was experimentally investigated during daylight and late evening hours. For these experiments, a cooker having an inner reflecting surface was designed, constructed by filling paraffin wax and metal shavings. The side- and sub-surface temperatures of the paraffin wax in the cooker were measured in the summer months of June and July. The thermal efficiency of the cooker was tested on different conditions. The results show that the optimum angle of the outer reflector is 30 degrees. Here, the peak temperature of the paraffin wax in the solar cooker was 83.4 degrees C. The average solar radiation reflected makes a contribution of 9.26% to the temperature of paraffin wax with the outer reflector. The solar cooker with the outer reflector angle of 30 degrees receives also reflected radiation from the inner reflectors. Besides, the heating time decreased to approximately one hour. The designed solar cooker can be effectively used with 30.3% daily thermal efficiency and paraffin wax due to the amount of energy stored.
