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SEMPOZYUM BĐLĐM KURULU

Prof. Dr. Zehra AKDENĐZ Piri Reis Üniversitesi

Prof. Dr. Sevim AKYÜZ Kültür Üniversitesi

Prof. Dr. A. Nihat BERKER Sabancı Üniversitesi

Prof. Dr. Bedia Erim BERKER Đstanbul Teknik Üniversitesi

Prof. Dr. Can Fuat DELALE Đstanbul Teknik Üniversitesi

Prof. Dr. Gülay DERELĐ Yıldız Teknik Üniversitesi

Prof. Dr. Bekir KARAOĞLU Đstanbul Aydın Üniversitesi

Prof. Dr. Mustafa KESKĐN Erciyes Üniversitesi

Prof. Dr. Ş. Erol OKAN Trakya Üniversitesi

Prof. Dr. Oktay SĐNANOĞLU Yale Üniversitesi

Prof. Dr. Yani SKARLATOS Boğaziçi Üniversitesi

Prof. Dr. Bilal TANATAR Bilkent Üniversitesi

Prof. Dr. Hasan TATLIPINAR Yıldız Teknik Üniversitesi

Prof. Dr. Mehmet TOMAK Ortadoğu Teknik Üniversitesi

Prof. Dr. Đskender YILGÖR Koç Üniversitesi

Prof. Dr. Ersin YURTSEVER Koç Üniversitesi

SEMPOZYUM DÜZE�LEME KURULU

Prof. Dr. Zehra AKDENĐZ Piri Reis Üniversitesi

Yrd. Doç. Dr. Ali KARAMAN Đstanbul Üniversitesi

Yrd. Doç. Dr. Zeynep Çiçek ÖNEM Đstanbul Üniversitesi

Hanifi ARSLAN Piri Reis Üniversitesi

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Sıvıhal Fiziği Çalışma Grubu

13. ULUSAL SIVIHAL FĐZĐĞĐ SEMPOZYUMU 27-29 Ekim 2009

Piri Reis Üniversitesi Konferans Salonu, Tuzla, Đstanbul

PROGRAM

27 October/Ekim 2009, Tuesday/Salı 10.00-13.00 Registration/Kayıt

10.15-10.30 Opening/Açılış

Chairperson/Oturum Başkanı: Zehra Akdeniz 10.30-11.10 Water: Its Physics, (anophysics, Chemistry, and Geopolitics

A. �ihat Berker (Sabancı Üniversitesi)

BREAK / ARA 11.20-11.50 Lanthanide-alkali metal halide systems: characterization and prediction of

phase diagram topology Marcelle Gaune Escard, Leszek Rycerz, Slobodan Gadzuric (Ecole Polytechnique, Mecanique Energetique, Technopole de Chateau-Gombert, France)

11.50-12.20 A-body system problem: (on-symmetrized Basis Function for Identical Particles Mario Gattobigio, A.Kievsky and M.Viviani (�ice Sophia Antipolis University, France)

12.20-12.40 Su Damlalarının Su Tutmayan Yüzeyler Üzerindeki Hareketinin Fısıldayan Galeri Modları ile Gözlenmesi Y. Karadağ, M. Y. Yüce, A. Kiraz, M. Bayındır (Koç Üniversitesi)

12.40-13.00 Single Wall Carbon (anotubes Under Uniaxial Strain

Gülay Dereli, �ecati Vardar, Önder Eyecioğlu (Yıldız Teknik Üniversitesi)

13.00-13.20 Density profiles and inertia moments of interacting bosons in anisotropic harmonic confinement A Đ. Meşe, P. Capuzzi, Z. Akdeniz, Ş. E. Okan

(Trakya Üniversitesi)

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13.30-14.30 LU�CH/ÖĞLE YEMEĞĐ

Chairperson/Oturum Başkanı: Bilal Tanatar 14.40-15.20 Localization-Delocalization Transition in Ultracold Atomic Mixtures

Patrizia Vignolo (Institut �on Linéaire de �ice, C�RS-France)

15.20-15.40 Multilayered Quantum Wires and Quantum Dots Ş. Aktaş (Trakya Üniversitesi)

BREAK / ARA 15.50-16.10 The Binding Energy of the Multilayered Spherical Quantum Dot under a

Magnetic Field F. K. Boz, Ş. Aktaş, Ş. E. Okan (Trakya Üniversitesi)

16.10-16.30 Density-of-State and Transport Properties for Random Dimer Hamiltonian S. Sucu, Ş. Aktaş, P. Vignolo, Z. Akdeniz, Ş.E. Okan (Trakya Üniversitesi)

16.30-16.50 Effect of Laser on Quantum Well B. Bekar, Ş. Aktaş, F. K. Boz, Ş. E. Okan (Trakya Üniversitesi)

16.50-17.10 The multilayered cubic quantum dot under the external fields Özge Kılıçoğlu, Ş. Aktaş, F. K. Boz, Ş. E. Okan (Trakya Üniversitesi)

28 October/Ekim 2009, Wednesday/Çarşamba Chairperson/Oturum Başkanı: Hasan Tatlıpınar 10.30-11.10 Water Dynamics in the Hydration Shell of a Protein

Cem Servantie (Sabancı Üniversitesi)

11.10-11.30 Reorientation of Carbon (anotubes by Liquid Crystal Mediums S. Eren San (Gebze Yüksek Teknoloji Enstitüsü)

11.30-11.50 Density functional theory study on molecular structure and vibrational spectra of m- methylaniline M. Kumru, T. Bardakçı, L. Sarı (Fatih Üniversitesi)

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11.50-12.10

Optical and Microstructural Properties of Tm3+ Doped (1-x)TeO2-(x)ZnO-5TiO2 Glasses Đdris Kabalcı (Harran Üniversitesi)

BREAK / ARA 12.20-12.50 Simulation of Atomic and Molecular Clusters and Complexes

Mustafa Böyükata (Bozok Üniversitesi)

12.50-13.10 DFT study of titanium-doped boron clusters: TiBn (n=1-9) M. Akar, M. Böyükata, Z. B. Güvenç (Bozok Üniversitesi)

13.10-13.30 Benzene hosting on 4-, 5- and 6-atom cage boron clusters �. Elmas, M. Böyükata, Z. B. Güvenç (Bozok Üniversitesi)

13.30-14.30 LU�CH/ÖĞLE YEMEĞĐ

Chairperson/Oturum Başkanı: Gülay Dereli 14.40-15.20 Scale Separation in Cavitating Flows

Can Fuat Delale (Đstanbul Teknik Üniversitesi)

15.20-15.50 Lantan Elementinin Aşırı Đnce Yapısının Đncelenmesi

Feyza Güzelçimen, Gönül Başar (Đstanbul Üniversitesi)

15.50-16.20 Feedforward neural network approach to nonlinear optics of nematic liquid crystals �ihat Yıldız (Cumhuriyet Üniversitesi)

29 October/Ekim 2009, Thursday/Perşembe 11.00-16.00 Çalıştay; Aşırısoğuk Atomik Sistemler, Trakya Üniversitesi, Edirne

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Water: Its Physics, �anophysics, Chemistry, and Geopolitics

A. �ihat Berker

Sabancı Üniversitesi

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Lanthanide-alkali Metal Halide Systems: Characterization and Prediction of Phase Diagram Topology

Marcelle Gaune-Escard1, Leszek Rycerz 2, Slobodan Gadzuric3

(1) Ecole Polytechnique, Mecanique Energetique, Technopole de Chateau-Gombert,

5 rue Enrico Fermi, 13453 Marseille Cedex 13, France (2) Chemical Metallurgy Group, Faculty of Chemistry, Wroclaw University of Technology,

Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland (3)Faculty of Science, Department of Chemistry, University of (ovi Sad,

Trg. D. Obradovica 3, 21000 (ovi Sad, Serbia

E-mail : marcelle.gaune-escard@polytech.univ-mrs.fr

Complex phase equilibria in lanthanide halide-alkali metal halide systems are

characterized by the existence of several stoichiometric compounds. Their stability depends

both on the nature of cations (lanthanide, alkali) and of the halide.

A simple scheme for classifying phase diagram topology, with predictive capability, is

presented.

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�on-simmetryzed Hyperspherical Harmonics basis for A _ 4 system M. Gattobigioa, A. Kievskyb, and M. Vivianib

aUniversit´e de Nice, INLN, 1361 Route des Lucioles, 06560 Valbonne, France. (Mario.Gattobigio@inln.cnrs.fr) bIstituto Nazionale di Fisica Nucleare, Largo Pontecorvo 3, 56100 Pisa, Italy. The Hyperspherical Harmonic (HH) method has been widely used in nuclear physics to describe nuclei with A=3,4 [1]. The extension to larger systems is hampered by the large degeneracy of the HH basis. The construction of specifically anti-symmetric states reduces the dimensionality of the basis but encounters technical and numerical difficulties. The coefficients of anti-symmetric basis elements, constructed as a linear combination of HH basis elements times appropriate spin-isospin vectors, are the more difficult to obtain the larger the number of basis elements and/or the number of particles considered; however, once the basis has been anti-symmetrized, the solution of the Schroedinger equation becomes much easier because the potential energy matrix elements can be calculated efficiently. In a preliminary work [2,3] we have discussed the possibility of using the HH method without resorting to the construction of anti-symmetrized basis states, and we have used the proposed formalism to calculate the discrete states of A=3,4 nuclei described by a simple nucleon-nucleon potential. The obvious disadvantage of the proposed approach lies in the very large basis that one needs to handle, which has to be balanced with the simplicity of avoiding the initial construction of antisymmetric basis states; the physical basis states, having the desired symmetry, are automatically generated in the diagonalization of the Hamiltonian. In the present talk we extend the use of non-symmetrized HH basis set to systems made of A = 5, 6 body. The growing dimension of the basis set is taken into account by avoiding the explicit construction of the Hamiltonian; we show that the Hamiltonian can be written as a sum of tensor products of sparse matrices. These matrices are the transformation coefficients of HH constructed with different sets of Jacobi vectors [4], and the potential energy evaluated on the reference Jacobi set. This factorization of the Hamiltonian permits to calculate its action on a vector, that is the basic ingredient for an iterative diagonalization.

References 1. A. Kievsky, S. Rosati, M. Viviani, L.E. Marcucci, and L. Girlanda, J. Phys. G: Nucl. Part. Phys. 35, 063101 (2008). 2. M. Gattobigio, A. Kievky, M. Viviani, and P. Barletta Phys. Rev. A 79, 032513 (2009). 3. M. Gattobigio, A. Kievky, M. Viviani, and P. Barletta Few-Body Systems 45, 127 (2009). 4. M. Viviani, Few-Body Systems 25, 177 (1998).

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Su Damlalarının Su Tutmayan Yüzeyler Üzerindeki Hareketinin Fısıldayan Galeri Modları ile Gözlenmesi

Yasin Karadağ1, M. Yavuz Yüce1, Alper Kiraz1, Mehmet Bayındır2

1 Koç Üniversitesi, Fizik Bölümü, Sarıyer, Đstanbul

2 Bilkent Üniversitesi, Fizik Bölümü, Çankaya, Ankara

Su tutmayan yüzeyler sıvıhal fiziğinde ilgi çeken bir araştırma konusu olmuştur. Bu

konudaki çalışmaların önemli bir kısmı su tutmama özelliği ile yüzey pürüzlülüğü arasındaki bağlantının anlaşılmasını amaçlamaktadır.

Su tutmayan yüzey üzerine bırakılan bir su damlası -pürüzlülüğün derecesine bağlı olarak- yüzeyi tamamen ıslatmayabilir. Bu durumda damla sadece belirli noktalardan yüzeye tutunur (Şekil 1), ve yüzey üzerindeki hareketi de bu tutunma noktaları arasındaki atlamalar şeklinde gerçekleşir [1]. Bu çalışmalara katkı sağlaması umuduyla spektroskopi temelli yeni bir teknik geliştirmekteyiz [2]. Bu teknikte su tutmayan yüzey üzerinde bulunan su damlası kızılötesi bir lazer kullanılarak ısıtılmakta, ve meydana gelen hacim değişiklikleri damla içinde oluşturulan fısıldayan galeri modları yardımıyla izlenmektedir. Kullandığımız tekniği klasik temas açısı ölçümlerinden farklı kılan özellikler mikrometre boyutundaki damlalarla çalışabilmemiz ve oluşturduğumuz hacim değişikliğini –bir yoğuşma hücresi yardımıyla- geri dönüşümlü olarak kontrol edebilmemizdir. Aerojel, nanoparçacık, ve tanecik-nanoparçacık karışımı su tutmayan yüzeyler kullanarak yapmış olduğumuz ilk denemelerde kızılötesi lazerin gücünü bir sinüs dalgası şeklinde değiştirerek, fısıldayan galeri modlarının gözlendiği dalgaboyunun zamana bağlı değişimini izledik (Şekil 2-3). Modlardaki değişim aerojel yüzeylerde sinüs dalgası şeklinde olup lazer gücündeki değişimi yansıtırken, nanoparçacık yüzeylerde sinüs dalgasından sapmalar görüldü. Tanecik-nanoparçacık karışımı yüzeylerde ise bu sapmalar daha da arttı. Sinüs dalgasındaki bozulmalar ani hacim değişikliklerine karşılık gelmektedir ve su damlasının haraketi sırasında yüzeyle olan temas noktaları arasındaki atlamalara işaret etmektedir.Bu yönüyle, kullandığımız teknik su tutmaz yüzeylerde görülen farklı ıslatma türlerinin incelenmesinde yararlı olabilir.

Şekil 1 (üst) : Damlanın su tutmayan üzerindeki duruşunu gösteren temsili çizim. Şekil 2-3 (sağ): Aerojel (üst), ve tanecik-nanoparçacık karışımı (alt) yüzeyler ile yapılan ölçümlerde fısıldayan galeri modlarının zamana bağlı değişimi.

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Single Wall Carbon �anotubes Under Uniaxial Strain

G.Dereli, �.Vardar* and Ö.Eyecioğlu**

Deparment of Physics,Yildiz Technical University,Istanbul,Turkey, gdereli@yildiz.edu.tr *Deparment of Physics,Yildiz Technical University,Istanbul,Turkey,

necativardar@gmail.com ** Deparment of Physics,Yildiz Technical University,Istanbul,Turkey, oeyeci@yildiz.edu.tr

Single Wall Carbon Nanotubes (SWCNTs) have attracted wide attention for application in

nano-devices due to their remarkable electronic and mechanical properties. Depending on

their chirality, they could be metal or semiconductor. Electronic and mechanical properties of

semiconducting single wall carbon nanotubes can also be modulated by an application of

uniaxial strain. In this study, we will report on the change of electronic and mechanical

properties of semiconducting single wall carbon nanotubes under uniaxial strain. Changes in

the electronic structure will be displayed through Fermi energy level, density of states and

energy band gaps of the semiconducting SWCNTs. Change in the mechanical properties will

be expressed in terms of elastic limit, Poisson ratio and Young’s modulus of the SWCNTs.

During our simulations we used the parallel, Order N Tight-Binding Molecular Dynamics

technique which is improved and successfully applied to SWCNTs simulations by G. Dereli

et. al. The research reported here was supported through the Yıldız Technical University

Research Found Project No: 24-01-01-04. Simulations are performed in parallel environment

at Carbon Nanotube Simulation Laboratory of Yıldız Technical University, Physics

Department.(http://www.yildiz/edu/tr/~gdereli/lab_homepage/index.html)

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Density Profiles and Inertia Moments of Interacting Bosons in Anisotropic Harmonic Confinement

A I. Mese1, P Capuzzi2, Z Akdeniz3 and S E Okan1

1 Department of Physics, Trakya University, 22030 Edirne, Turkey 2 Consejo (acional de Investigaciones Cient´ıficas y T´ecnicas and Departamento de F´ısica,

FCEy(, Universidad de Buenos Aires, Buenos Aires, RA-1428, Argentina 3 Physics Department, Piri Reis University, 34940 Tuzla, Istanbul, Turkey

We study a rubidium gas of few atoms trapped by anisotropic two-dimensional

harmonic potential, interacting via a K0(r) potentials [1] which is proper for two dimensional

systems within the variational approximation. Increasing the anisotropy of the confinement

potential can drive the system from a two-dimensional 2D to a one-dimensional 1D

configuration. We found analytical expression for the inertia moment. as a function of the

number and position of the particles in the system.

Our results of the ground state configurations are compared with recent experiments

[2] and published numerical results [3,4] and we obtained a satisfactory agreement.

[1] Nelson D R and Seung H S, Phys. Rev. B, 39 9153, 1989

[2] M Saint Jean and C Guthmann, J. Phys.: Condens. Matter 14 (2002) 13653–13660

[3] A. I. Mese, P Capuzzi, J. Phys.: Condens. Matter 20 , 335222, 2008

[4] S. W. S. Apolinario, B. Partoens, and F. M. Peeters, Physical Review E 72, 046122 2005

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Localization-Delocalization Transition in Ultracold Atomic Mixtures

Patrizia Vignolo

Institut (on Linéaire de (ice, C(RS-France

We propose an experiment to study the transport properties of a Bose-Einstein condensate in

the presence of short-range correlated disorder where defects appear as dimers (random-dimer

model). We suggest an experimental scheme and calculate the parameters entering the

effective Hamiltonian for a realistic experiment where a first atomic species plays the role of

impurities for the second one. We show that a localization-delocalization transition occurs

when the interspecies scattering length is increased, and evaluate the localization length and

the transmittivity across this transition.

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Multilayered Quantum Wires and Quantum Dots

Şaban Aktaş

Department of Physics, Trakya University, Edirne 22030, Turkey

sabana@trakya.edu.tr The binding energy of a hydrogenic impurity in the multilayered quantum wires and

dots is investigated as a function of the barrier thickness for different impurity positions under

the external electric and the magnetic fields. Within the effective mass approximation, the

ground state binding energy of a hydrogenic impurity is found employing a variational

method. It is found that the binding energy in critical barrier thickness shows an increase or

decrease depending on the impurity position, the magnetic and the electric field strengths.

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The Binding Energy of the Multilayered Spherical Quantum Dot under a Magnetic Field

F. K. Boz, S. Aktas, S. E. Okan

Department of Physics, Trakya University, Edirne 22030, Turkey

figenb@trakya.edu.tr

The binding energy of an impurity located at the center of multilayered spherical

quantum dot (MSQD) is reported under the influence of a magnetic field. Within the effective

mass approximation, the binding energy has been calculated using the fourth order Runge-

Kutta method without magnetic field. A variational approach has been employed if a

magnetic field is present. The binding energy in MSQD with equal dot and barrier thickness is

calculated. Our results show that the structural confinement is very effective for thin MSQD,

and the influence of magnetic field is more effective according to the geometric effect for

thick MSQD.

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Density-of-State and Transport Properties for Random Dimer Hamiltonian

S.Sucu1, Ş.Akatş1, P.Vignolo2, Z.Akdeniz3, S.E.Okan1

1)Deparment of Physics, Trakya University, Edirne-22030, Turkey 2)Institut (on Linéaire de (ice, C(RS-Fransa

3)Piri Reis Üniversitesi, Đstanbul-Tuzla, Turkey

We study the transport prorerties and density-of-state of Bose-Einstein Condensation

in periodic optical lattice with short-range correlated disorder. One of the simplest and

succesfull examples of correlate disorder is the short-range order of the Random Dimer

Model(RDM). It consists in the random distribution of dimers along a tight-binding linear

chain; this is realized when one of the two-site energies of the chain is assigned to couples of

adjacent sites; thus one of the components of the lattice is a cluster made by a couple of sites

with the sama energy (E2_E2) or different energy (E2_E1).

We describe the system by means of a 1D Bose-Hubbard Hamiltonian, using a

renormalization of the scattering lengths to embody the transverse confinement. The

Hamiltonian is not explicitly solved, but the whole lattice is reduced to a single dimer by a

renormalization/decimation procedure. Incoming and outgoing leads are connected to the

effective dimer and the steady-state transport coefficient of the bosons is inferred from the

evaluation of the scattered wave function of the leads due to the presence of the dimer.

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Effect of Laser on Quantum Well

Bahadır Bekar, Şaban Aktaş, Figen Karaca Boz, Ş. Erol Okan

Department of Physics, Trakya University, 22030 Edirne, Turkey

In this work, we are investigated effects of laser on symetric quantum square well

using the finite different method. The effects of the different amplitude laser on the binding

energy are observed.the binding energy decrases with increasing amplitute of laser. this

behavior was presented in the Ref[1,2]

References: 1) E.C. �iculescu , L.M. Burileanu, A. Radu “Density of impurity states of shallow donors in a quantum well under intense laser field” Superlattices and Microstructures 2008 2) E. Kasapoğlu, H. Sari, I. Sökmen “Binding energy of impurity states in an inverse parabolic quantum well under magnetic field” Physica B 390 (2007) 216–219. 3) H. Sari , E. Kasapoğlu, I. Sökmen “The effect of an intense laser field on magneto donors in semiconductors” Physics Letters A 311 (2003) 60–66 4) F. M. S. Lima, M. A. Amato,, L. S. F. Olavo, O. A. C. �unes, A. L. A. Fonseca,1 and E. F. da Silva, Jr. “Intense laser field effects on the binding energy of impurities in semiconductors” 10.1103/PhysRevB.75.073201 5) Q. Fanyao., L.A. Fonseca and, O.A.C. �unes “Intense Laser Field Effect on Confined Hydrogenic Impurities in Quantum Semiconductors” phys. stat. sol. (b) 197,349 (1996) 6) C. S. Han “Dressing Effect on the Electron-Atom Scattering in Intense Laser Field “CHINESE JOURNAL OF PHYSICS VOL. 31. NO. 3 JUNE 1993 7) Yaşam Saften yüksek lisans tezi 2007 8) Emine Ozturk, ismail Sokmen “ Effect of the intense laser field on the valance band for Ga1−xAlxAs/GaAs heterostructure” Superlattices and Microstructures Volume 45, Issue 1, January 2009, Pages 16-21

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The Multilayered Cubic Quantum Dot Under the External Fields

Ozge Kilicoglu, Saban Aktas, Figen Karaca Boz and S.Erol Okan

Trakya University Art and Science Faculty Physics Department, Edirne, Turkey

In this work, we have investigated the binding energy of the hydrogenic impurity of

the multilayerd cubic GaAs(Ga,Al)As quantum dot (MCQD) as a function of the barrier

thickness and the inner dot thickness under the electric and magnetic field strengths.” We

calculate the ground state energy implementing the finite difference method. The binding

energy of hydrogenic impurity located at the center of a quantum dot has been studied with a

variational approach.We found that the binding energy depends on the geometry of the dot,

the magnetic and the electric field strengths. Our results are good agreement with the pervious

works.

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Water Dynamics in the Hydration Shell of a Protein

Cem Servantie

Faculty of Engineering and (atural Sciences, Sabanci University, Istanbul, Turkey Water is essential for the stability and function of proteins. For instance the equilibrium shape

of a protein is dictated by the hydrophobic folding process. Moreover, water modies

dynamical properties of proteins such as the dynamic transition temperature, Td , above which

proteins are biologically active. The dynamics of the hydration shell water/protein association

for two dierent folded proteins (lysozyme and myoglobin) are studied thanks to molecular

dynamics simulations. The results show that the number of water molecules within a cuto

distance of each residue scales linearly with protein depth. Keeping track of the water

molecules within the cuto sphere, one can compute an effective residence time, scaling

inversely with depth index at physiological temperatures and a temperature independent

stretch exponent. A depth independent orientational memory loss is obtained for the average

dipole vector of the water molecules within the sphere when the protein is functional. The

hydration layer surrounding the protein is slaved by the fluctuations of the residues below the

transition temperature. At the transition, the slavery process ceases and water molecules

collectively make the protein more exible, slowly relaxing matter.

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Reorientation of Carbon �anotubes by Liquid Crystal Mediums

S. Eren San

Department of Physics, Gebze Institute of Technology, 41400, Kocaeli, Türkiye erens@gyte.edu.tr

Carbon nanoparticle-Liquid Crystal dispersions have been subject for scientific interest not

only because they are efficient candidates for improving the performance of Liquid Crystal

(LC) based devices but also such systems are promising for controlling the orientation of

carbon nanotubes1-2-3. In the scope of this work, Single Walled Walled Carbon Nanotubes

(SWCNT) are employed in Nematic LC host so that an electrically and magnetically steered

switch structures would be constructed. Proposed devices exploit the conductivity anisotropy

of nanotubes in combination with the reorientation of Nematic LC, which sweeps and

reinforces the neighbour nanotubes. The performances of the systems are characterized by

conductivity measurements. It was found that such systems could be proposed as sensors and

nano-electronic components.

References: [1] I. Dierking, G. Scalia, P. Morales, Advanced Materials, 16, 865 (2004). [2] M.D. Lynch, D.L. Patrick, (ano Letters, 2, 1197 (2002). [3] I. Dierking, S. E. San , Applied Physics Letters, 87 233507, (2005) 233507

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Density Functional Theory Study on Molecular Structure and Vibrational Spectra of M-methylaniline

M. Kumru, T. Bardakçı, L. Sarı

Fatih University, Faculty of Arts and Sciences, Department of Physics, 34500 Büyükçekmece,

Istanbul, Turkey We have discussed the applicability limits of HF, MP2 and DFT-B3LYP methods on m-

methylaniline in our previous work*. We have found the DFT-B3LYP method very promising

for vibrational spectral analyses.

In this study, we extend DFT calculations with different basis sets for more

appropriateness to exprimental results. The optimized molecular structures, vibrational

frequencies and coresponding vibrational assigments of m- methylaniline have been obtained

from the DFT-B3LYP, DFT-B3PW91 and DFT-PBEPBE methods implementing the 6-

311G+** and aug-ccPVQZ basis sets. Scale factors, which bring computational frequencies in

closer agreement with the experimental data, have been calculated for predominant vibrational

motions of the normal modes at each level considered. All observed harmonic IR and Raman

bands of m- methylaniline have been assigned in the frameworks of the calculations. The

comparison of calculations with FT-IR and FT-Raman spectra of m- methylaniline have been

carried out.

Keywords: m-methylaniline, Infrared and Raman spectra, Ab initio calculations, Density functional theory (DFT), �ormal mode * A. Altun, K. Gölcük, M. KUMRU, Journal of Molecular Structure (Theochem) 625 (2003) 17–24

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Optical and Microstructural Properties of Tm3+ Doped (1-x)TeO2-(x)ZnO 5TiO2 Glasses

Đdris Kabalcı

Harran University, Education Faculty, Physics Education, Şanlıurfa kabalci@harran.edu.tr, kabalci@itu.edu.tr

Tellurite based optical glasses exhibit significant properties which give them important

industrial applications such as fiber lasers, fiber optic amplifiers, and laser hosts. The aim of

this investigation is the fabrication and characterization of the ternary tellurite based glasses

with zinc oxide-titanium oxide by using melt-quenching techniques. In this work, the optical

and microstructural properties of Tm3+ doped (1-x)TeO2-(x)ZnO-5TiO2 glasses were

synthesized for different ZnO glass compositions. From measurements of the optical

absorption (UV-VIS) on very thin bulk glass samples, the optical band gap (Eg) was

determined for the different compositions. In addition, the density of each glasses was

determined by using Archimede’s prenciple with distilled water as the immersion liquid.

Furthermore, glass characteristic temperatures such as, glass transition (Tg), crytallization

(Tc), and melting temperatures (Tm) were determined by using Differantial Thermal Analiysis

(DTA) investigations in the temperature range between 20 and 700oC with the heating rate of

10oC/min. Crytallization types of each glass samples were characterized by FT-IR

spectroscopy and XRD techniques.

Keywords: Tellurite glasses, thermal analysis, energy band gap, laser materials.

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Simulation of Atomic and Molecular Clusters and Complexes

Mustafa Böyükata

Department of Physics, Bozok University, 66200 Yozgat, Turkey

In this talk our resent studies on simulation of atomic and molecular clusters and complexes

will be presented. Structural and energetic analysis have been realized for pure metal clusters

(Fe, Au, Ti, V, Cr, Cu and Pd) [1-5] via Molecular Dynamics (MD) by using pair potentials.

Characteristic changes in structural arrangements of atoms have been observed around

energetically magic sizes. Similarly, rearrangement approximation has been improved for

ArnCO2 complexes [6] with MD method and pair-additive potentials. Density Functional

Theory (DFT) studies on hydrogenated boron clusters such as B4Hn series and hydrogen

hosting on cage B5-B10 has been reported in Refs. [7-9], respectively. The effect of metal (like

Al and Ti) putting in boron clusters for hydrogenations are under investigations. Various

structural isomers for Al-doped boron microclusters and their hydrogenated complexes have

been optimized by using DFT/B3LYP functional and 6-311++G** basis set [10]. Our

findings (binding energies, HOMO-LUMO energies, fragmentation energies and second order

energy differences of these clusters) will be discussed in detail through comparing with

literature [11-13].

Acknowledgment. This work is partially supported by TUBITAK (Grand No. 108T466).

References [1] Böyükata, M., et al., J. Alloys and Compounds, 403, 349, (2006). [2] Böyükata, M., Physica E, 33, 182, (2006). [3] Böyükata, M., J. Theo. Comp. Chem., 6, 81, (2007). [4] Böyükata, M.,Belchior, J.C., J. Brazilian Chem. Soc., 19, 884, (2008). [5] Böyükata, M.,Belchior, J.C., Croatica Chemica Acta, 81, 289, (2008). [6] Böyükata, M., et al., Canadian J. Chem., 85, 1, 47, (2007). [7] Böyükata, M.,Özdoğan, C., Güvenç, Z.B., J. Mol. Struc.-Theochem, 805, 91, (2007). [8] Böyükata, M.,Özdoğan, C., Güvenç, Z.B., Physica Scripta, 77, 025602, (2008). [9] Böyükata, M.,Özdoğan, C., Güvenç, Z.B., Romanian J. Inf. Sci. Tech., 11, 59, (2008). [10] Frisch M. J. et. al., GAUSSIA( 03, Revision D.01, Gaussian Inc., Wallingford, CT, (2004). [11] Atış, M., Özdoğan, C., Güvenç, Z.B., J. Quantum Chem., 107, 3, 729, (2007). [12] Liu, X., et. Al., Phys. Rev. A 75, 063201, (2007). [13] Feng, J.X., and Luo, Y.H., J. Phys. Chem. A, 111, 2420, (2007).

.

DFT Study of Titanium-doped Boron Clusters: TiBn (n=1-9)

M. Akar1, M. Böyükata1, Z. B. Güvenç2

1Department of Physics, Bozok University, 66200 Yozgat, Turkey

2Department of Elect. and Comm. Eng., Çankaya University, 06530 Ankara, Turkey

In this preliminary work the geometry optimizations have been carried out for titanium doped

boron microclusters by using DFT/B3LYP functional and 6-311++G** basis set [1]. The

lower-lying energy configurations of TiBn clusters up to n=9 are presented. The obtained

stable structures of TiBn clusters for n=1-3,9 and for n=4-8 prefer two-dimensional and three-

dimensional arrays, respectively. Binding energies, HOMO-LUMO energies, fragmentation

energies and second order energy differences of these clusters have been obtained. The results

are compared with pure Bn clusters [2] and any boron-metal complexes [3-6].

Acknowledgment. This work is supported by TUBITAK (Grand No. 108T466).

References

[1] Frisch M. J. et. al., GAUSSIA( 03, Revision D.01, Gaussian Inc., Wallingford, CT, (2004).

[2] Atış, M., Özdoğan, C., Güvenç, Z.B., J. Quantum Chem., 107, 3, 729, (2007).

[3] Liu, X., Zhao, G.F., Guo, L.J., Jing, Q., Luo, Y.H., Phys. Rev. A 75, 063201, (2007).

[4] Feng, J.X., and Luo, Y.H., J. Phys. Chem. A, 111, 2420, (2007).

[5] Yang, Z., and Xiong, S.J., J. Chem. Phys., 128, 184310, (2008).

[6] Yao, J.G., Wang, X.W., and Wang, Y.X., Chem. Phys., 351, 1, (2008).

.

Benzene Hosting on 4-, 5- and 6-atom Cage Boron Clusters

�. Elmas1, M. Böyükata1, Z. B. Güvenç2

1Department of Physics, Bozok University, 66200 Yozgat, Turkey

2Department of Elect. and Comm. Eng., Çankaya University, 06530 Ankara, Turkey

A theoretical study based on Density Functional Theory has been performed to investigate the

electronic structure of benzene hosted cage boron microstructures by using B3LYP functional

and 6-311g basis set [1]. Total energies, binding energies, HOMO-LUMO energy gaps,

frequencies, electronic state, structural parameters and point groups of structures have been

calculated for Bm(C6H5)n, (m=4,5,6 and n≤m) complexes. Within a similar way of previous

works [2,3] boron clusters here are used as bridge between the molecules. It is observed that

the cage form of the boron clusters have structural stability.

Acknowledgment. This work is supported by TUBITAK (Grand No. 108T466).

References

[1] Frisch, M. J. et. al., Gaussian 03, revision D.01, Gaussian, Inc., Wallingford, CT, 2004.

[2] Qiu, Y. Q. et. al., Chinese Science Bulletin 52, 2326 (2007).

[3] Peng, B. et. al., Chemical Physics 356, 171 (2009).

.

Scale Separation in Cavitating Flows

Can Fuat Delale

Istanbul Technical University

The two-phase homogeneous bubbly mixture model is discussed as a model of

hydrodynamic cavitation with recent modifications. In particular, its application to quasi-

one-dimensional and two-dimensional bubbly cavitating nozzle flows will be considered to

obtain model equations of cavitating nozzle flows. In quasi-one-dimensional flows, by

scale separation the model equations can be cast into two normalized evolution equations

for the bubble radius and for the flow speed where the rest of the flow variables (the

normalized pressure, void fraction and the density) are related to the solution of these

evolution equations. In particular, the pressure, void fraction and the dilation are shown to

satisfy a relation independent of flow dimensionality. For two-dimensional nozzle flows,

three evolution equations are obtained for the bubble radius and for the flow velocity,

where the unsteady acceleration field is shown to satisfy equations that constitute the

fundamental equations for the generation of the normalized dilation and of the normalized

vorticity in 2-D cavitating flows. For non-cavitating flow, the fundamental equations

reduce to the classical Cauchy-Riemann equations (existence of the complex velocity

potential) of potential flow.

.

Lantan Elementinin Aşırı Đnce Yapısının Đncelenmesi

Feyza Güzelçimen , Gönül Başar

Đstanbul Üniversitesi, Fen Fakültesi, Fizik Bölümü, 34459 Vezneciler, Đstanbul-Türkiye

feyzag@istanbul.edu.tr

Aşırı ince yapı incelemelerinde enerjideki ayrışmaları hesaplayabilmek için, A manyetik dipol

ve B elektrik kuadropol aşırı ince yapı sabitlerine ihtiyaç vardır. Bu çalışmada, 5d-kabuğu

metallerinden Lantan (139La) elementinin aşırı ince yapısı, deneysel olarak Laser Uyarılmış

Floresans Spektroskopisi (LIF) metodu ile incelenmiştir. 139La (çekirdek spini I = 7/2) kararlı

izotopunun atomik spektrumu, büyük çekirdek manyetik dipol momentle µI = 2.7830455(9)µ(

ve buna karşılık küçük elektrik kuadropol momentle Q = -0.20(1)b tanımlanmaktadır.

Deneysel olarak elde edilen spektrumların aşırı ince yapı analizi, Classification ve Fitter

bilgisayar programları ile yapılmıştır. La elementinin 595–635 nm dagaboyu aralığındaki

spektral geçişlerinin alt-üst enerji seviyeleri ve bu seviyelere ait A manyetik dipol ve B

elektrik kuadropol aşırı ince yapı sabitleri belirlenmiştir.

.

Feedforward �eural �etwork Approach to �onlinear Optics of �ematic Liquid Crystals

�ihat Yıldız

Cumhuriyet University, Faculty of Science and Literature, Dept. of Physics, 58140, Sivas, TURKEY

nyildiz@cumhuriyet.edu.tr

Inherent nonlinearity, among other important issues, poses serious difficulties in constructing

empirical formulas for both explaining and predicting the experimental physical data. In this

paper, to produce explicit nonlinear empirical formulas for nonlinear optics of nematic liquid

crystals (NLCs) [1], we introduce and apply a novel method. This method is entirely based on

an appropriate layered feedforward neural network (LFNN) application to extract the

inherited nonlinearity involved in various nonlinear optical properties of NLCs. We first

observe that with universal nonlinear function approximation capabilities [2], the LFNN is

also relevant to experimental physics [3]. To illustrate the relevance of LFNN to nonlinear

optics of NLCs, we second present LFNN results applied to some nonlinear experimental

electro-optical responses of NLCs [4]. Finally, we conclude that LFNN can be a very useful

tool in analysing the induced nonlinear perturbations in physical properties of doped NLCs.

References [1] Khoo I C 2009 Physics Reports 471 221-267. [2] Hornik K, Stinchcombe M and White H 1989 (eural (etworks 2 359-366. [3] Yildiz N 2005 Phys Lett. A 345 (1-3) 69-87. [4] Yildiz N, San S E, Okutan M and Kaya H (submitted to J of Phys Condensed Matter)