Photopolymerizable Nanocomposites For Holographic Applications,
2010
Technological University Dublin
Photopolymerizable Nanocomposites For Holographic Applications, Elsa Leite
Doctoral
Photopolymerizable nanocomposites with good optical properties consisting of an acrylamide based photopolymer and zeolite nanoparticles (Beta, zeolite A, AlPO-18, silicalite-1 and zeolite L) were fabricated and characterized for holographic applications. The colloidal zeolite solutions used in this project were characterized by several techniques including X-Ray Diffraction (XRD), Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM) and Raman spectroscopy to ensure their successful synthesis. The dependence of grating performances in these nanocomposites on recording intensity, spatial frequency and zeolite concentration were studied. It was found that the incorporation of silicalite-1 nanoparticles or a small amount of zeolite A nanoparticles (up to …
A Phenomenographic Study Of Introductory Physics Students: Approaches To Their Learning And Perceptions Of Their Learning Environment In A Physics Problem-Based Learning Environment,
2010
Technological University Dublin
A Phenomenographic Study Of Introductory Physics Students: Approaches To Their Learning And Perceptions Of Their Learning Environment In A Physics Problem-Based Learning Environment, Paul Irving
Doctoral
This phenomenographic study describes students’ approaches to learning and their perceptions of the learning environment in an introductory physics course which is taught using a problem-based learning approach. This research builds on previous studies which showed that these students develop a greater conceptual knowledge than their counterparts in a more traditional learning environment while others showed very little development even though they engaged fully with the pedagogy. This study aimed to examine and describe the students’ approaches to learning. The definitions of surface, strategic and deep approaches to learning are not appropriate in this context and could not be applied …
Magnetocaloric Effect In Thin Films And Heterostructures,
2010
University of South Florida
Magnetocaloric Effect In Thin Films And Heterostructures, Christopher Bauer
USF Tampa Graduate Theses and Dissertations
The goals of this work are the optimization of the magnetocaloric effect in Gadolinium thin film structures. We approach this issue from two directions, that of process optimization and of interface effects. Past results showed Gd2O3 in our Gadolinium thin films, and the presence of such oxide seemed to grow with the temperature at which the film was grown or annealed. Comparison of samples grown without chamber gettering to those that were gettered show differences in their structural and magnetic properties, and we conclude that gettering is an effective step in enhancing the quality of Gd thin …
Pmma-Cnt Matrices For Vacuum Electronic, Biosensing And Energy Applications,
2010
Michigan Technological University
Pmma-Cnt Matrices For Vacuum Electronic, Biosensing And Energy Applications, Archana Pandey
Dissertations, Master's Theses and Master's Reports - Open
Carbon nanotubes (CNTs) are interesting materials with extraordinary properties for various applications. Here, vertically-aligned multiwalled CNTs (VA-MWCNTs) are grown by our dual radio frequency plasma enhanced chemical vapor deposition (PECVD). After optimizing the synthesis processes, these VA-MWCNTs were fabricated in to a series of devices for applications in vacuum electronics, glucose biosensors, glucose biofuel cells, and supercapacitors In particular, we have created the so-called PMMA-CNT matrices (opened-tip CNTs embedded in poly-methyl methacrylate) that are promising components in a novel energy sensing, generation and storage (SGS) system that integrate glucose biosensors, biofuel cells, and supercapacitors. The content of this thesis work …
Dielectrophoretic Choking Phenomenon In A Converging-Diverging Microchannel,
2010
Old Dominion University
Dielectrophoretic Choking Phenomenon In A Converging-Diverging Microchannel, Ye Ai, Shizhi Qian, Sheng Liu, Sang W. Joo
Mechanical & Aerospace Engineering Faculty Publications
Experiments show that particles smaller than the throat size of converging-diverging microchannels can sometimes be trapped near the throat. This critical phenomenon is associated with the negative dc dielectrophoresis arising from nonuniform electric fields in the microchannels. A finite-element model, accounting for the particle-fluid-electric field interactions, is employed to investigate the conditions for this dielectrophoretic (DEP) choking in a converging-diverging microchannel for the first time. It is shown quantitatively that the DEP choking occurs for high nonuniformity of electric fields, high ratio of particle size to throat size, and high ratio of particle's zeta potential to that of microchannel. © …
Determining Metastable Densities In An Argon Discharge Through Optical Emission Spectroscopy,
2010
Wright State University
Determining Metastable Densities In An Argon Discharge Through Optical Emission Spectroscopy, Jared A. Miles
Browse all Theses and Dissertations
A plasma diagnostic technique has been experimentally demonstrated where optical emission measurements of relative intensities of spectral lines in the violet range were combined with available electron-impact cross sections to yield absolute Ar metastable species concentration. An enabling factor of this analysis was that the electron excitation pattern was quite different between the Ar ground state and the metastable state. The result of this pattern was that the optical spectrum was unique depending on whether the emission was generated by direct excitation from the ground state, or by stepwise excitation from one of the metastable states. This study has shown …
Phonon Transmission Via Nanojunctions In Bcc Waveguides,
2010
TÜBİTAK
Phonon Transmission Via Nanojunctions In Bcc Waveguides, Ouahiba Nafa, Boualem Bourahla, Rachid Tigrine
Turkish Journal of Physics
Coherent and ballistic phonon transport via nanojunctions between bcc lattices is presented. The model system A/B/A consists of a finite number of bcc atomic layers of an element B sandwiched between two bcc semi-infinite crystals of another element A. The matching method theoretical approach is used to study the dynamical properties of the bcc sandwich system. A calculation is presented for the coherent reflection and transmission scattering probabilities of the system phonons, as elements of a Landauer type scattering matrix. The scattering and transmission spectra via the nanojunctions are analyzed as a function of the incident frequency per propagating mode …
Computations Of Ultrasonic Parameters Of Lanthanide Metals Ti, Zr And Hf,
2010
TÜBİTAK
Computations Of Ultrasonic Parameters Of Lanthanide Metals Ti, Zr And Hf, Pramod Kumar Yadawa, Dharmendra Kumar Pandey, Devraj Singh, Raja Ram Yadav, Giridhar Mishra
Turkish Journal of Physics
The ultrasonic properties in the hexagonal structured lanthanide metals Ti, Zr and Hf have been studied at room temperature. The higher order elastic constants have been calculated for these metals using Lennard-Jones Potential for evaluating orientation-dependent ultrasonic properties. An anomalous behaviour in orientation dependent velocity is obtained, which is due to the combined effect of second order elastic constants and density. The achieved ultrasonic properties are compared with known physical parameters to differentiate them from third group nitrides/laves phase compounds.
Sublimation Of Graphite In Continuous And Pulsed Arc Discharges,
2010
TÜBİTAK
Sublimation Of Graphite In Continuous And Pulsed Arc Discharges, Afshan Ashraf, Kashif Yaqub, Sumera Javeed, Sumaira Zeeshan, Rahila Khalid, Sohail Ahmad Janjua, Shoaib Ahmad
Turkish Journal of Physics
Sublimation of graphite has been investigated in continuous and pulsed arc discharges. The results of continuous arc discharge between graphite electrodes are compared with pulsed arc discharge between cylindrical Aluminum cathode and annular graphite anode. The sublimed species include monoatomic and diatomic carbon clusters with their relative composition depending upon the mechanism of energy dissipation in graphite electrodes. Diatomic carbon (C_2) is the dominant subliming cluster. Emission spectroscopy of the Swan band system [d^3\prod _g -a^3\prod _u ] of C_2 has been used to investigate the thermodynamic state and to deduce the vibrational temperature (T_{vib}). The vibrational level densities indicate …
Chemical Bath Deposition And Characterization Of Cu_2o-Cu_Xs Thin Films,
2010
TÜBİTAK
Chemical Bath Deposition And Characterization Of Cu_2o-Cu_Xs Thin Films, D. D. O. Eya
Turkish Journal of Physics
Cu_2O-Cu_xS thin films have been deposited on glass substrate by chemical bath deposition technique. The films were obtained by depositing Copper Sulphide (Cu_xS) on Copper (I) Oxide (Cu_2O) and then Cu_2O on Cu_xS. The peak solar transmittance across the thin films were found to be
Vibration Spectra Of Polar Mixing Optical Phonon States And Fröhlich Electron-Phonon Coupling Behaviors In A Wurtzite Zno Quantum Dot, Li Zhang
Turkish Journal of Physics
Based on the dielectric continuum model and Loudon's uniaxial crystal model, the interface-optical-propagating (IO-PR) mixing phonon states of a quasi-zero-dimensional (Q0D) wurtzite cylindrical quantum dot (QD) are investigated. It is found that there are two types of IO-PR mixing phonon modes, i.e. \rho-IO/z-PR mixing modes and the z-IO/\rho-PR mixing modes coexisting in Q0D wurtzite QDs. Numerical calculation on a wurtzite ZnO QD shows that the dispersion frequencies of the mixing modes are discrete functions of the azimuthal quantum number and axial wave-number. The calculated results agree well with the recent experimental spectra in ZnO QDs. An abnormal electron-phonon coupling strength …
Inept Nmr Spectroscopy Of ^{14}Nd_N Groups: Product Operator Theory And Simulation,
2010
TÜBİTAK
Inept Nmr Spectroscopy Of ^{14}Nd_N Groups: Product Operator Theory And Simulation, Deni̇z Türkpençe, İrfan Şaka, Azmi̇ Gençten
Turkish Journal of Physics
Product operator formalism is widely used for the analytical description of multi-dimensional and multiple-pulse NMR experiments for the weakly coupled spin systems having spin-1/2 and spin-1 nuclei. The INEPT NMR experiment is a polarization transfer experiment including J-coupling. In this study, the INEPT NMR experiment was analytically investigated by using product operator theory for weakly coupled IS_n(^{14}ND_n) (I=1, S=1; n=1, 2, 3) spin systems. The obtained theoretical results represent the FID values of ^{14}ND_n groups. In order to make Fourier transform of the obtained FID values, a Maple program is used and then simulated spectra of the INEPT experiment are …
On The S-Wave Jost Solution For Coulomb-Distorted Nuclear Potential,
2010
TÜBİTAK
On The S-Wave Jost Solution For Coulomb-Distorted Nuclear Potential, Ujjwal Laha, Bibekananda Kundu
Turkish Journal of Physics
A closed form expression of the off-shell Jost solution for Coulomb plus separable nuclear potential is derived using interacting Green's functions and their integral transforms. As an application of our result the off-shell Jost function for the proton-proton scattering in the ^1S_0 channel is computed for various laboratory energies to investigate the role of long range Coulomb interaction in off-shell scattering.
Assessment Of The Accuracy Of An Ultrasound Elastography Liver Scanning System Using A Pva-Cryogel Phantom With Optimal Acoustic And Mechanical Properties,
2010
St. James's Hospital, Dublin
Assessment Of The Accuracy Of An Ultrasound Elastography Liver Scanning System Using A Pva-Cryogel Phantom With Optimal Acoustic And Mechanical Properties, S. Cournane, Louise Cannon, Jacinta Browne, Andrew Fagan
Articles
The accuracy of a transient elastography liver-scanning ultrasound system was assessed using a novel application of PVA-cryogel as a tissue-mimicking material with acoustic and shear elasticity properties optimized to best represent those of liver tissue. Although the liver scanning system has been shown to offer a safer alternative for diagnosing liver cirrhosis through stiffness measurement, as compared to the liver needle biopsy exam, the scanner’s accuracy has not been fully established. The Young’s elastic modulus values of 5-6wt% PVA cryogel phantoms, also containing glycerol and 0.3μm Al2O3 and 3μm Al2O3, were measured using a ‘gold standard’ mechanical testing technique and …
The Study Of Radio Frequency Interference (Rfi) For Radio Astronomy In Some Remote Locations In Peninsular Malaysia.,
2010
Universiti Malaya
The Study Of Radio Frequency Interference (Rfi) For Radio Astronomy In Some Remote Locations In Peninsular Malaysia., Syed Bahari Ramadzan Syed Adnan
Student Works (2010-2019)
Radio Frequency Interference (RFI) is the main parameter to find the best site for radio astronomy research development. The increasing levels of RFI will pose a big problem for researchers in the radio astronomy field. The radio astronomers are encouraged to choose sites as free as possible from interference. In this research we aimed to survey the RFI at frequency 1 MHz-2000MHz to look the overview of the RFI profile and at frequency 1419 MHz-1421 MHz to monitor the RFI profile at Hydrogen line frequency (1420.4 MHz). We chose Peninsular Malaysia as the research area for RFI observation. We have …
Intonation And Compensation Of Fretted String Instruments,
2010
Loyola Marymount University
Intonation And Compensation Of Fretted String Instruments, Gabriele U. Varieschi, Christina M. Gower
Physics Faculty Works
We discuss theoretical and physical models that are useful for analyzing the intonation of musical instruments such as guitars and mandolins and can be used to improve the tuning on these instruments. The placement of frets on the fingerboard is designed according to mathematical rules and the assumption of an ideal string. The analysis becomes more complicated when we include the effects of deformation of the string and inharmonicity due to other string characteristics. As a consequence, perfect intonation of all the notes on the instrument cannot be achieved, but complex compensation procedures can be introduced to minimize the problem. …
Selected Studies Of Orbital Stability And Habitability In Star-Planet Systems,
2010
University of Texas at Arlington
Selected Studies Of Orbital Stability And Habitability In Star-Planet Systems, William Jason Eberle
Physics Dissertations - Archive
The study of planets remaining in orbit around one star with another starinterfering is an important topic of orbital mechanics and astrobiology. The onset of instability for a planet which is part of a stellar binary system is investigated by performing numerical simulations of the circular restricted three body problem. Synodic velocity phase space portraits are used with the hodograph in order to obtain a new criterion for determining planetary stability. The stability limits obtained via these methods agree with previous methods that were obtained based on simulations over much longer time intervals. In addition, the timely case of a …
Synthesis Of Cdte And Pbs Semiconductor Quantum Dots And Their Biological And Photochemical Applications,
2010
University of Texas at Arlington
Synthesis Of Cdte And Pbs Semiconductor Quantum Dots And Their Biological And Photochemical Applications, Xing Zhang
Physics Theses - Archive
Semiconductor quantum dots are inorganic nanoparticles with unique photophysical properties. In particular, water soluble quantum dots which have been synthesized by colloidal chemistry in aqueous environment are highly luminescent. Their huge absorption cross sections, tunable, narrow emission bands and effectiveness of surface functionality have stimulated these luminescent probes in various applications like biological sensors as well as imaging contrast agents. In this paper we will discuss several aspects about the synthesize processes of the water soluble, highly luminescent type of CdTe quantum dots and its near infrared counterpart HgxCd1-xTe, the extremely crystallized PbS quantum dots with the application of the …
Search For Standard Model Higgs In Two Photon Final State At Atlas,
2010
University of Texas at Arlington
Search For Standard Model Higgs In Two Photon Final State At Atlas, Hyeon Jin Kim
Physics Dissertations - Archive
The Standard Model of particle physics describes very precisely the nuclear strong and weak forces and the eletromagnetic interaction, by the exchange of vector bosons. It also describes all matter as composed of quarks and leptons and predicts their interactions. The Higgs boson is the last missing piece of the Standard Model, yet to be observed. The search for the Higgs particle is one of the most important goals of the ATLAS experiment at the Large Hadron Collider (LHC). The ATLAS electromagnetic (EM) calorimeter is a crucial subdetector system of the ATLAS detector in searching for the Higgs boson, in …
The Role Of The Y-Component Of The Interplanetary Magnetic Field In Transpolar Saturation And Ring Current Response As Found In Data And Simulation,
2010
University of Texas at Arlington
The Role Of The Y-Component Of The Interplanetary Magnetic Field In Transpolar Saturation And Ring Current Response As Found In Data And Simulation, Elizabeth Joy Mitchell
Physics Dissertations - Archive
Energy is transferred into the magnetosphere of Earth through merging of magnetic fields (Dungey cycle and lobe cell convection) and through momentum transfer across the magnetopause (viscous interactions). These processes cause enhanced plasma convection in the inner magnetosphere and ionosphere, which in turn form the ring current and the transpolar potential, respectively. These processes have been studied extensively with regard to the role of the north-south component of the interplanetary magnetic field (IMF). The role of the dawn-dusk IMF is less well known.We use the LFM global MHD simulation, the CRCM, and data to quantify the transpolar potential and ring …
