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2013

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Articles 91 - 120 of 223

Full-Text Articles in Nanoscience and Nanotechnology

High Element Gold Nanorod Plasmonic Sensing Array For Harsh Environment Gas Detection Grant Proposal, Brian Janiszweski May 2013

High Element Gold Nanorod Plasmonic Sensing Array For Harsh Environment Gas Detection Grant Proposal, Brian Janiszweski

Nanoscale Science & Engineering (discontinued with class year 2014)

In order to acquire funding for scientific endeavors very specific grant proposal documents must be written and submitted. The following is an example of that. This project was very useful because my peers and I will undoubtedly have to write a grant of some type or another in our future careers. This specific proposal is a mock grant requesting money from the National Science Foundation to fund research into a gas sensor that utilizes gold nanostructures as sensing mechanism. The research done behind this project was performed over three semesters in the lab of Dr. Michael Carpenter form the College …

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Generation Of Saws In Ghz Range For Nanoscale Particle Removal, Leigh Kent Lydecker Iv May 2013

Generation Of Saws In Ghz Range For Nanoscale Particle Removal, Leigh Kent Lydecker Iv

Nanoscale Science & Engineering (discontinued with class year 2014)

In order to do research at CNSE, funding is required. Funding is achieved by submitting a grant proposal stating the background of the problem one hopes to address, a proposed solution, and sufficient information to prove success is achievable. These grant proposals follow a very particular format, which is extremely valuable to be familiar with in the scientific field of study. Therefore, learning to write a grant proposal for some of the work I have done during my undergraduate studies was proved a valuable learning experience. The following grant proposal is based on the work I have done during the …

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Neoadjuvant Therapy For Ovarian Cancer Using Bioglycogentm Nanoparticles Sbir Grant Proposal, Alexander E. Talamo May 2013

Neoadjuvant Therapy For Ovarian Cancer Using Bioglycogentm Nanoparticles Sbir Grant Proposal, Alexander E. Talamo

Nanoscale Science & Engineering (discontinued with class year 2014)

Project Summary Technical Abstract This Small Business Innovation Research Phase I project, presented by Talamo Inc., is to test an ovarian cancer therapeutic delivery system, comprised of a nanoscale biocompatible vesicle that carries a bioactive small interfering RNA molecule (siRNA), in vivio in mice. The siRNA has shown to reduce the expression of an enzyme (Sod2) that is highly expressed in multiple ovarian cancer types. The reduced expression of Sod2 will allow the tumor to become increasingly susceptible to chemotherapy agents, while simultaneously diminishing tumor progression. Research has proved that the nanoscale vesicle is non-toxic and in combination with siRNA …

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Electrical Characterization Of Gold Functionalized Dna Origami Nanotubes, Christopher Vinhtroung Buu May 2013

Electrical Characterization Of Gold Functionalized Dna Origami Nanotubes, Christopher Vinhtroung Buu

Boise State University Theses and Dissertations

Conductivity types (i.e., insulator, semiconductor, and conductor) can be tuned by varying the size of metallic nanoparticles. DNA origami, a molecular self-assembly technique, has promise to programmatically self-assemble nanoparticles (NPs) with nanometer precision. The work presented here demonstrates the programmatic self-assembly of AuNPs on DNA origami nanotubes (NTs). DNA origami NTs were also functionalized with positively charged Au clusters. DNA origami NTs, both bare and functionalized with Au, were electrically characterized using DC current-voltage (DC-IV) measurements. The measurements showed that bare, undecorated DNA NTs behaved as an insulator, whereas linear, ohmic conductivity was observed for Au enhanced Au decorated NTs. …

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Iii-V Bismide Optoelectronic Devices, Dongsheng Fan May 2013

Iii-V Bismide Optoelectronic Devices, Dongsheng Fan

Graduate Theses and Dissertations

This dissertation explores modeling, molecular beam epitaxy growth, and fabrication of III-V bismide optoelectronic devices, which are of great importance in modern applications of telecommunication, gas sensing, environment monitoring, etc. In the current room-temperature continuous-wave operational GaSb-based type-I InGaAsSb/AlGaInAsSb quantum well laser diodes in 3-4 um mid-wavelength range, the lasing wavelength and performance of the devices are limited due to the lack of hole confinement in the active regions. In this dissertation, a novel GaSb-based GaInAsSbBi material is proposed to replace the conventional InGaAsSb material in the quantum well region, which enables the laser diodes achieve up to 4 µm …

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Quantum Criticality Analysis By Finite-Size Scaling And Exponential Basis Sets, Fahhad H. Alberbi, Sabre Kais Apr 2013

Quantum Criticality Analysis By Finite-Size Scaling And Exponential Basis Sets, Fahhad H. Alberbi, Sabre Kais

Birck and NCN Publications

We combine the finite-size scaling method with the mesh-free spectral method to calculate quantum critical parameters for a given Hamiltonian. The basic idea is to expand the exact wave function in a finite exponential basis set and extrapolate the information about system criticality from a finite basis to the infinite basis set limit. The used exponential basis set, though chosen intuitively, allows handling a very wide range of exponential decay rates and calculating multiple eigenvalues simultaneously. As a benchmark system to illustrate the combined approach, we choose the Hulthen potential. The results show that the method is very accurate and …

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Broadband Enhancement Of Spontaneous Emission From Nitrogen-Vacancy Centers In Nanodiamonds By Hyperbolic Metamaterials, Mikhail Y. Shalaginov, Satoshi Ishii, J. Liu, Joseph Irudayaraj, A. Lagutchev, Alexander V. Kildishev, Vladimir M. Shalaev Apr 2013

Broadband Enhancement Of Spontaneous Emission From Nitrogen-Vacancy Centers In Nanodiamonds By Hyperbolic Metamaterials, Mikhail Y. Shalaginov, Satoshi Ishii, J. Liu, Joseph Irudayaraj, A. Lagutchev, Alexander V. Kildishev, Vladimir M. Shalaev

Birck and NCN Publications

We experimentally demonstrate a broadband enhancement of emission from nitrogen-vacancy centers in nanodiamonds. The enhancement is achieved by using a multilayer metamaterial with hyperbolic dispersion. The metamaterial is fabricated as a stack of alternating gold and alumina layers. Our approach paves the way towards the construction of efficient single-photon sources as planar on-chip devices. (C) 2013 AIP Publishing LLC.

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Pre-Breakdown Evaluation Of Gas Discharge Mechanisms In Microgaps, Abbas Semnani, Ayyaswamy Venkattraman, Alina A. Alexeenko, Dimitrios Peroulis Apr 2013

Pre-Breakdown Evaluation Of Gas Discharge Mechanisms In Microgaps, Abbas Semnani, Ayyaswamy Venkattraman, Alina A. Alexeenko, Dimitrios Peroulis

Birck and NCN Publications

The individual contributions of various gas discharge mechanisms to total pre-breakdown current in microgaps are quantified numerically. The variation of contributions of field emission and secondary electron emission with increasing electric field shows contrasting behavior even for a given gap size. The total current near breakdown decreases rapidly with gap size indicating that microscale discharges operate in a high-current, low-voltage regime. This study provides the first such analysis of breakdown mechanisms and aids in the formulation of physics-based theories for microscale breakdown. (C) 2013 AIP Publishing LLC

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An Electrochemical Impedance Spectroscopic Study Of Cuf2/Moo3/C Cathode Composites, Yue-Li Shi, Nan Wu, Ming-Fang Shen, Jia-Qun Dong, Quang-Chao Zhuang, Li Jiang Apr 2013

An Electrochemical Impedance Spectroscopic Study Of Cuf2/Moo3/C Cathode Composites, Yue-Li Shi, Nan Wu, Ming-Fang Shen, Jia-Qun Dong, Quang-Chao Zhuang, Li Jiang

Journal of Electrochemistry

Composite electrode of CuF2/MoO3/C was fabricated through high energy mechanical milling. The properties of CuF2/MoO3/C were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (TEM), galvanostatic charge-discharge measurements, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results showed that the grain sizes of CuF2 and MoO3 after milling were 200 ~ 300 nm, and the initial discharge capacity of CuF2/MoO3/C was 647 mAh·g-1 at room temperature and at a current density of 10 mA·g-1. However, the …

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Electrochemical Activities Of Oxygen-Doped Carbon Surface For V(Iv)/V(V) Redox Couple, Huan Zhang, Lin-Lin Qin, Yi-Ning Shi, Ming-Sen Zheng, Quan-Feng Dong, Zhao-Wu Tian Apr 2013

Electrochemical Activities Of Oxygen-Doped Carbon Surface For V(Iv)/V(V) Redox Couple, Huan Zhang, Lin-Lin Qin, Yi-Ning Shi, Ming-Sen Zheng, Quan-Feng Dong, Zhao-Wu Tian

Journal of Electrochemistry

Graphite plate electrodes were treated with oxygen plasma and doped with oxygen as well as oxygen functional groups. With the treatment, the activities of graphite plate electrodes toward VO2+/VO2+ redox reactions were improved. FT-IR and EDS analysis results indicated that oxygen functional groups were introduced to the surface of graphite plates after oxygen plasma treatment. In this paper, the graphite plate treated for 20 min showed the highest activity. The average charge efficiency reached 91%, suggesting an increase of 19%, compared with that of the untreated graphite plate under a current density of 8 mA·cm-2 …

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Preparation And Catalytic Properties Of Feco Alloy Nanocatalyst, Ming-Xuan Li, Jie-Lian Ou, Sheng-Pei Chen, Peng Wang, Bin-Bin Xu, Shi-Gang Sun Apr 2013

Preparation And Catalytic Properties Of Feco Alloy Nanocatalyst, Ming-Xuan Li, Jie-Lian Ou, Sheng-Pei Chen, Peng Wang, Bin-Bin Xu, Shi-Gang Sun

Journal of Electrochemistry

The FeCo alloy nanoparticles were electrodeposited on glassy carbon electrode by chronoamperometry and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the shapes of FeCo nanoparticles were cubes with an average size of 65 nm. The atom ratio of Fe and Co is 1:1. As indicated from the pattern of selected area electron diffraction (SAED), the FeCo cubic nanoparticles were single crystal which belonged to body-centered cubic with an interval of 0.201 nm referring to the (110) facets of FeCo alloy. The FeCo cubic nanoparticles exhibited the enhanced electrocatalytic …

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Fabrication And Localized Surface Plasmon Resonance Of Ultrathin Nanoporous Gold Films, Shi Feng, Shu Chen, Qing Yang, Juan Xiang Apr 2013

Fabrication And Localized Surface Plasmon Resonance Of Ultrathin Nanoporous Gold Films, Shi Feng, Shu Chen, Qing Yang, Juan Xiang

Journal of Electrochemistry

Ultrathin nanoporous gold films (NPGF) with a thickness of approximately 50 nm were fabricated via electrochemical dealloy method. The morphology of NPGF was evaluated with a parameter of surface roughness. SEM results demonstrate that the fabrication of NPGF with different roughness factors can be achieved by controlling the circles of cyclic voltammetry. UV-Vis spectra indicate that the localized surface plasmon resonance (LSPR) of NPGF is affected by the roughness of NPGF. With the optimal roughness factor, NPGF displays a linear relationship between the ethanediol concentration and the absorbance intensity at λ = 450 nm. The LSPR effect of NPGF presents …

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Electrochemical Synthesis Of Hierarchical Dendritic Polyaniline Nanostructures, Shao-Huang Weng, Jian-Zhang Zhou, Zhong-Hua Lin, Xin-Hua Lin Apr 2013

Electrochemical Synthesis Of Hierarchical Dendritic Polyaniline Nanostructures, Shao-Huang Weng, Jian-Zhang Zhou, Zhong-Hua Lin, Xin-Hua Lin

Journal of Electrochemistry

In this work, the p-TSA doped and hierarchical dendritic nanostructured polyanilines (PANI) have been prepared by potentiostatic electropolymerization without using any templates at room temperature. The mechanism of the polymerization has been discussed according to the electrodeposition curves. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to confirm the formation of uniform hierarchical dendritic structure on PANI. UV-Vis spectroscopy (UV-Vis) and infrared spectroscopy (FTIR) proved that the prepared PANI is in the form of emeraldine salt. The templateless electrodeposition method is simple, easy to operate, can be applied to fabricate other nanostructures of conducting polymers.

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Preparation And Methanol Electrooxidation Of Pt/Pmo12/Pedot/Gc Electrodes, Jing-Hua Ma, Rui-Xiang Wang, Yi-Liang Tan, Shan-Shan Wang, Yan-Qin Zhang, You-Jun Fan Apr 2013

Preparation And Methanol Electrooxidation Of Pt/Pmo12/Pedot/Gc Electrodes, Jing-Hua Ma, Rui-Xiang Wang, Yi-Liang Tan, Shan-Shan Wang, Yan-Qin Zhang, You-Jun Fan

Journal of Electrochemistry

Modification of phosphomolybdic acid (PMo12) on poly(3,4-ethylenedioxythiophene) (PEDOT) film (PEDOT/GC) obtained through the electrochemical polymerization was performed using adsorption method (PMo12/PEDOT/GC), followed by electrodepositing Pt on PMo12/PEDOT/GC to prepare Pt/PMo12/PEDOT/GC electrode. Effects of PMo12 and PEDOT on the methanol oxidation performance of electrode were investigated. Results showed that PMo12 obviously changed the morphology and structure of Pt loaded on the electrode, leading to the formation of sharp thorns at the edge of Pt nanostructures. Cyclic voltammetry and chronoamperometry data demonstrated that the catalytic activities of methanol electrooxidation on the Pt/PMo …

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Current Development Of Quantum Dots Based Electrochemiluminescence Immunosensors, Ling-Ling Li, Qian Lu, Jun-Jie Zhu Apr 2013

Current Development Of Quantum Dots Based Electrochemiluminescence Immunosensors, Ling-Ling Li, Qian Lu, Jun-Jie Zhu

Journal of Electrochemistry

Electrochemiluminescence exhibits the merits of both luminescence and electrochemistry analysis, and has been extensively employed in biosensors. Quantum dots are considered one of the three main kinds of electrochemiluminescence luminophores due to their unique properties. This paper briefly reviews the classification and signal amplification technology of quantum dots based electrochemiluminescence immunosensors. Future research trends are also suggested.

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Synthesis And Electrocatalysis Of Pdcu Alloy Nanocrystals, Hai-Bin Wu, Rui-Zhong Zhang, Wei Chen Apr 2013

Synthesis And Electrocatalysis Of Pdcu Alloy Nanocrystals, Hai-Bin Wu, Rui-Zhong Zhang, Wei Chen

Journal of Electrochemistry

Monodispersed PdCu alloy nanoparticles were synthesized by co-reduction of Cu(acac)2 and Pd(acac)2 with 1, 2-hexadecanediol. The spherical and popcorn-like shapes of PdCu alloy nanoparticles were obtained by changing the ratios of mixed surface protecting ligands of 1-octadecene, and oleylamine or oleic acid. TEM and XRD measurements showed that both PdCu nanoparticles are alloy nanocrystals dominated with (111) planes and the average sizes are 12.7 ± 0.18 and 20.4 ± 0.31 nm for he spherical and popcorn-like PdCu nanoparticles, respectively. The electrocatalytic activities of the PdCu nanocrystals for formic acid oxidation were evaluated by electrochemical cyclic voltammetry (CV). The result showed …

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Evidence For Effective Mass Reduction In Gaas/Algaas Quantum Wells, A. T. Hatke, M. A. Zudov, J. D. Watson, Michael J. Manfra, L. N. Pfeiffer, K. W. West Apr 2013

Evidence For Effective Mass Reduction In Gaas/Algaas Quantum Wells, A. T. Hatke, M. A. Zudov, J. D. Watson, Michael J. Manfra, L. N. Pfeiffer, K. W. West

Birck and NCN Publications

We have performed microwave photoresistance measurements in high mobility GaAs/AlGaAs quantum wells and investigated the value of the effective mass. Surprisingly, the effective mass, obtained from the period of microwave-induced resistance oscillations, is found to be about 12% lower than the band mass in GaAs, m(b)*. This finding provides strong evidence for electron-electron interactions which can be probed by microwave photoresistance in very high Landau levels. In contrast, the measured magnetoplasmon dispersion revealed an effective mass which is close to m(b)*, in accord with previous studies. DOI: 10.1103/PhysRevB.87.161307

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Modification Of Nanostructures Via Laser Processing, Louis Franzel Apr 2013

Modification Of Nanostructures Via Laser Processing, Louis Franzel

Theses and Dissertations

Modification of nanostructures via laser processing is of great interest for a wide range of applications such as aerospace and the storage of nuclear waste. The primary goal of this dissertation is to improve the understanding of nanostructures through two primary routes: the modification of aerogels and pulsed laser ablation in ethanol. A new class of materials, patterned aerogels, was fabricated by photopolymerizing selected regions of homogeneous aerogel monoliths using visible light. The characterization and fabrication of functionally graded, cellular and compositionally anisotropic aerogels and ceramics is discussed. Visible light was utilized due to it’s minimal absorption and scattering by …

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Investigation Of Surface Properties For Ga- And N-Polar Gan Using Scanning Probe Microscopy Techniques, Josephus Daniel Ferguson Iii Apr 2013

Investigation Of Surface Properties For Ga- And N-Polar Gan Using Scanning Probe Microscopy Techniques, Josephus Daniel Ferguson Iii

Theses and Dissertations

Because the surface plays an important role in the electrical and optical properties of GaN devices, an improved understanding of surface effects should help optimize device performance. In this work, atomic force microscopy (AFM) and related techniques have been used to characterize three unique sets of n-type GaN samples. The sample sets comprised freestanding bulk GaN with Ga polar and N polar surfaces, epitaxial GaN films with laterally patterned Ga- and N-polar regions on a common surface, and truncated, hexagonal GaN microstructures containing Ga-polar mesas and semipolar facets. Morphology studies revealed that bulk Ga-polar surfaces treated with a chemical-mechanical polish …

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Thermoelectric Properties Of Epitaxial Scn Films Deposited By Reactive Magnetron Sputtering Onto Mgo(001) Substrates, Polina V. Burmistrova, Jesse Maassen, Tela Favaloro, Bivas Saha, Shuaib Salamat, Yee Rui Koh, Mark S. Lundstrom, Ali Shakouri, Timothy D. Sands Apr 2013

Thermoelectric Properties Of Epitaxial Scn Films Deposited By Reactive Magnetron Sputtering Onto Mgo(001) Substrates, Polina V. Burmistrova, Jesse Maassen, Tela Favaloro, Bivas Saha, Shuaib Salamat, Yee Rui Koh, Mark S. Lundstrom, Ali Shakouri, Timothy D. Sands

Birck and NCN Publications

Epitaxial ScN(001) thin films were grown on MgO(001) substrates by dc reactive magnetron sputtering. The deposition was performed in an Ar/N-2 atmosphere at 2 x 10(-3) Torr at a substrate temperature of 850 degrees C in a high vacuum chamber with a base pressure of 10(-8) Torr. In spite of oxygen contamination of 1.6 +/- 1 at. %, the electrical resistivity, electron mobility, and carrier concentration obtained from a typical film grown under these conditions by room temperature Hall measurements are 0.22 m Omega cm, 106 cm(2) V-1 s(-1), and 2.5 x 10(20) cm(-3), respectively. These films exhibit remarkable thermoelectric …

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Length And Temperature Dependent 1/F Noise In Vertical Single-Walled Carbon Nanotube Arrays, Robert A. Sayer, Jeffrey D. Engerer, N. S. Vidhyadhiraja, Timothy S. Fisher Apr 2013

Length And Temperature Dependent 1/F Noise In Vertical Single-Walled Carbon Nanotube Arrays, Robert A. Sayer, Jeffrey D. Engerer, N. S. Vidhyadhiraja, Timothy S. Fisher

Birck and NCN Publications

We report measurements of temperature-and length-dependent 1/f noise in vertical single-walled carbon nanotube (SWCNT) arrays. Carbon nanotubes are synthesized in a porous anodic alumina template with sub-micrometer channel lengths ranging from 100 to 700 nm. A significant difference is observed in the 1/f noise magnitude of quasi-ballistic and diffusive SWCNT devices, with quasi-ballistic devices exhibiting 1/f noise levels that are one to two orders of magnitude less than diffusively conducting devices. Furthermore, 1/f noise was measured from 90 to 400 K, and the noise prefactor decreased significantly at temperatures below 250 K. (C) 2013 AIP Publishing LLC. [http://dx.doi.org/10.1063/1.4800856]

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Atomic Force Microscopy-Coupled Microcoils For Cellular-Scale Nuclear Magnetic Resonance Spectroscopy, Charilaos Mousoulis, Teimour Maleki, Babak Ziaie, Corey Neu Apr 2013

Atomic Force Microscopy-Coupled Microcoils For Cellular-Scale Nuclear Magnetic Resonance Spectroscopy, Charilaos Mousoulis, Teimour Maleki, Babak Ziaie, Corey Neu

Birck and NCN Publications

We present the coupling of atomic force microscopy (AFM) and nuclear magnetic resonance (NMR) technologies to enable topographical, mechanical, and chemical profiling of biological samples. Here, we fabricate and perform proof-of-concept testing of radiofrequency planar microcoils on commercial AFM cantilevers. The sensitive region of the coil was estimated to cover an approximate volume of 19.4 x 10(3) mu m(3) (19.4 pl). Functionality of the spectroscopic module of the prototype device is illustrated through the detection of H-1 resonance in deionized water. The acquired spectra depict combined NMR capability with AFM that may ultimately enable biophysical and biochemical studies at the …

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Mechanism Of Fatigue Performance Enhancement In A Laser Sintered Superhard Nanoparticles Reinforced Nanocomposite Followed By Laser Shock Peening, Dong Lin, Chang Ye, Yiliang Liao, Sergey Suslov, Richard Liu, Gary J. Cheng Apr 2013

Mechanism Of Fatigue Performance Enhancement In A Laser Sintered Superhard Nanoparticles Reinforced Nanocomposite Followed By Laser Shock Peening, Dong Lin, Chang Ye, Yiliang Liao, Sergey Suslov, Richard Liu, Gary J. Cheng

Birck and NCN Publications

This study investigates the fundamental mechanism of fatigue performance enhancement during a novel hybrid manufacturing process, which combines laser sintering of superhard nanoparticles integrated nanocomposites and laser shock peening (LSP). Through laser sintering, TiN nanoparticles are integrated uniformly into iron matrix to form a nanocomposite layer near the surface of AISI4140 steel. LSP is then performed on the nanocomposite layer to generate interaction between nanoparticles and shock waves. The fundamental mechanism of fatigue performance enhancement is discussed in this paper. During laser shock interaction with the nanocomposites, the existence of nanoparticles increases the dislocation density and also helps to pin …

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High-Resolution Correlation Spectroscopy Of 13c Spins Near A Nitrogen-Vacancy Centre In Diamond, Abdelghani Laraoui, Florian Dolde, Christian Burk, Friedemann Reinhard, Jorg Wrachtrup, Carlos A. Meriles Apr 2013

High-Resolution Correlation Spectroscopy Of 13c Spins Near A Nitrogen-Vacancy Centre In Diamond, Abdelghani Laraoui, Florian Dolde, Christian Burk, Friedemann Reinhard, Jorg Wrachtrup, Carlos A. Meriles

Department of Mechanical and Materials Engineering: Faculty Publications

Spin complexes comprising the nitrogen-vacancy centre and neighbouring spins are being considered as a building block for a new generation of spintronic and quantum information processing devices. As assembling identical spin clusters is difficult, new strategies are being developed to determine individual node structures with the highest precision. Here we use a pulse protocol to monitor the time evolution of the 13C ensemble in the vicinity of a nitrogenvacancy centre. We observe long-lived time correlations in the nuclear spin dynamics, limited by nitrogen-vacancy spin–lattice relaxation. We use the host 14N spin as a quantum register and demonstrate that hyperfine-shifted resonances …

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The Effect Of Network Transitions On Spontaneous Activity And Sycnhrony In Devloping Neural Networks, Jude P. J. Savarraj Apr 2013

The Effect Of Network Transitions On Spontaneous Activity And Sycnhrony In Devloping Neural Networks, Jude P. J. Savarraj

Doctoral Dissertations

Connectivity patterns of developing neural circuits and the effects of its dynamics on network behavior, particularly the emergence of spontaneous activity and synchrony, are not clear. We attempt to quantify anatomical connectivity patterns of rat cortical cultures during different stages of development. By culturing the networks on dishes embedded with micro electrode arrays, we simultaneously record electrical activity from multiple regions of the developing network and monitor its electrical behavior, particularly its tendency to fire spontaneously and to synchronize under certain conditions. We investigate possible correlations between changes in the network connectivity patterns and spontaneous electrical activity and synchrony. Cocultures …

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Intrinsic Mode Function Synchronization Measures For The Anticipation Of Seizures In Epilpsy, Daniel William Moller Apr 2013

Intrinsic Mode Function Synchronization Measures For The Anticipation Of Seizures In Epilpsy, Daniel William Moller

Doctoral Dissertations

Epileptic seizures affect as many as 50 million people and often occur without warning or apparent provocation. We explore the applicability of noise-assisted Ensemble Empirical Mode Decomposition (EEMD) for patient-specific seizure anticipation synchronization measures as applied to the EEMD intrinsic mode function (IMF) output. Intracranial EEG data were obtained from pre-surgical monitoring at the Epilepsy Center of the University Hospital of Freiburg. Data from twenty patients were analyzed. For each recorded channel, non-overlapping time windows were submitted to the EEMD algorithm, producing twelve levels of IMFs. IMF synchronization measures (mean and maximum coherence, mean and maximum cross-correlation, correlation coefficient and …

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Thickness-Shear Vibration Of A Rectangular Quartz Plate With Partial Electrodes, Huijing He, Jiashi Yang, John A. Kosinski, Ji Wang Apr 2013

Thickness-Shear Vibration Of A Rectangular Quartz Plate With Partial Electrodes, Huijing He, Jiashi Yang, John A. Kosinski, Ji Wang

Department of Mechanical and Materials Engineering: Faculty Publications

We study free vibration of a thickness-shear mode crystal resonator of AT-cut quartz. The resonator is a rectangular plate partially and symmetrically electroded at the center with rectangular electrodes. A single-mode, three-dimensional equation governing the thickness-shear displacement is used. A Fourier series solution is obtained. Numerical results calculated from the series show that there exist trapped thickness-shear modes whose vibration is mainly under the electrodes and decays rapidly outside the electrodes. The effects of the electrode size and thickness on the trapped modes are examined.

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Nanopatterning Of Metal-Coated Silicon Surfaces Via Ion Beam Irradiation: Real Time X-Ray Studies Reveal The Effect Of Silicide Bonding, Osman El-Atwani, Sean Gonderman, Alexander Demasi, Anastassiya Suslova, Justin Fowler, Mohamad El-Atwani, Karl Ludwig, Jean Paul Allain Mar 2013

Nanopatterning Of Metal-Coated Silicon Surfaces Via Ion Beam Irradiation: Real Time X-Ray Studies Reveal The Effect Of Silicide Bonding, Osman El-Atwani, Sean Gonderman, Alexander Demasi, Anastassiya Suslova, Justin Fowler, Mohamad El-Atwani, Karl Ludwig, Jean Paul Allain

Birck and NCN Publications

We investigated the effect of silicide formation on ion-induced nanopatterning of silicon with various ultrathin metal coatings. Silicon substrates coated with 10 nm Ni, Fe, and Cu were irradiated with 200 eV argon ions at normal incidence. Real time grazing incidence small angle x-ray scattering (GISAXS) and x-ray fluorescence (XRF) were performed during the irradiation process and real time measurements revealed threshold conditions for nanopatterning of silicon at normal incidence irradiation. Three main stages of the nanopatterning process were identified. The real time GISAXS intensity of the correlated peaks in conjunction with XRF revealed that the nanostructures remain for a …

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Full Band Calculations Of The Intrinsic Lower Limit Of Contact Resistivity, Jesse Maassen, C. Jeong, A. Baraskar, M. Rodwell, Mark S. Lundstrom Mar 2013

Full Band Calculations Of The Intrinsic Lower Limit Of Contact Resistivity, Jesse Maassen, C. Jeong, A. Baraskar, M. Rodwell, Mark S. Lundstrom

Birck and NCN Publications

The intrinsic lower limit of contact resistivity (rho(LL)(c)) for InAs, In0.53Ga0.47As, GaSb, and Si is calculated using a full band ballistic quantum transport approach. Surprisingly, our results show that rho(LL)(c) is almost independent of the semiconductor. An analytical model, derived for 1D, 2D, and 3D, correctly reproduces the numerical results and explains why rho(LL)(c) is very similar in all cases. Our analysis sets a minimal carrier density required to meet the International Technology Roadmap for Semiconductors call for rho(c) x 10(-9) Omega-cm(2) by 2023. Comparison with experiments shows there is room for improvement, which will come from optimizing interfacial properties. …

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Coupled Vibrational Modes In Multiple-Filled Skutterudites And The Effects On Lattice Thermal Conductivity Reduction, Liang Guo, Xianfan Xu, J. R. Salvador, G. P. Meisner Mar 2013

Coupled Vibrational Modes In Multiple-Filled Skutterudites And The Effects On Lattice Thermal Conductivity Reduction, Liang Guo, Xianfan Xu, J. R. Salvador, G. P. Meisner

Birck and NCN Publications

The influence of guest atoms on thermal conduction in filled skutterudites was studied using ultrafast reflectance spectroscopy. Different filling species cause coupled vibrational modes between the guest atoms and the host lattice at different frequencies, which scatter phonons in different spectral spans. Using a Debye model for the measured lattice thermal conductivity together with the measured vibration frequencies and scattering rates, it is shown that scattering due to the coupled vibrational modes has a considerable contribution to the suppression of lattice thermal conduction. This demonstrates that filling with multiple species can efficiently reduce the lattice thermal conductivity in skutterudites. (C) …

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