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An Efficient Second Order In Time Scheme For Approximating Long Time Statistical Properties Of The Two Dimensional Navier-Stokes Equations, Xiaoming Wang Aug 2012

An Efficient Second Order In Time Scheme For Approximating Long Time Statistical Properties Of The Two Dimensional Navier-Stokes Equations, Xiaoming Wang

Mathematics and Statistics Faculty Research & Creative Works

We investigate the long-time behavior of the following efficient second order in time scheme for the 2D Navier-Stokes equations in a periodic box: The scheme is a combination of a 2nd-order in time backward-differentiation and a particular explicit Adams-Bashforth treatment of the advection term. Therefore, only a linear constant coefficient Poisson solver is needed at each time step. We prove uniform in time bounds on this scheme in L 2, H per1 and H per2 provided that the time-step is sufficiently small. These time uniform estimates further lead to the convergence of long-time statistics (stationary statistical properties) of the scheme …

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Oscillation And Spectral Theory For Linear Hamiltonian Systems With Nonlinear Dependence On The Spectral Parameter, Martin Bohner, Werner Kratz, Roman Šimon Hilscher Aug 2012

Oscillation And Spectral Theory For Linear Hamiltonian Systems With Nonlinear Dependence On The Spectral Parameter, Martin Bohner, Werner Kratz, Roman Šimon Hilscher

Mathematics and Statistics Faculty Research & Creative Works

In this paper, we consider linear Hamiltonian differential systems which depend in general nonlinearly on the spectral parameter and with Dirichlet boundary conditions. Our results generalize the known theory of linear Hamiltonian systems in two respects. Namely, we allow nonlinear dependence of the coefficients on the spectral parameter and at the same time we do not impose any controllability and strict normality assumptions. We introduce the notion of a finite eigenvalue and prove the oscillation theorem relating the number of finite eigenvalues which are less than or equal to a given value of the spectral parameter with the number of …

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Conceptions Of Topological Transitivity, Ethan Akin, Jeffrey D. Carlson Aug 2012

Conceptions Of Topological Transitivity, Ethan Akin, Jeffrey D. Carlson

Mathematics and Statistics Faculty Research & Creative Works

There are several different common definitions of a property in topological dynamics called "topological transitivity," and it is part of the folklore of dynamical systems that under reasonable hypotheses, they are equivalent. Various equivalences are proved in different places, but the full story is difficult to find. This note provides a complete description of the relationships among the different properties. © 2012 Elsevier B.V.

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Experimental Composite Guidance Conduits For Peripheral Nerve Repair: An Evaluation Of Ion Release, X. F. Zhang, A. Coughlan, H. O'Shea, Mark R. Towler, S. Kehoe, D. Boyd Aug 2012

Experimental Composite Guidance Conduits For Peripheral Nerve Repair: An Evaluation Of Ion Release, X. F. Zhang, A. Coughlan, H. O'Shea, Mark R. Towler, S. Kehoe, D. Boyd

Chemical and Biochemical Engineering Faculty Research & Creative Works

Poly (lactide-co-glycolide) (PLGA) - Pluronic F127 - glass composites have demonstrated excellent potential, from the perspective of controlled mechanical properties and cytocompatibility, for peripheral nerve regeneration. In addition to controlling the mechanical properties and cytotoxicity for such composite devices, the glass component may mediate specific responses upon implantation via degradation in the physiological environment and release of constituent elements. However, research focused on quantifying the release levels of such therapeutic ions from these experimental medical devices has been limited. To redress the balance, this paper explores the ion release profiles for Si4+, Ca2+, Na+, …

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A Highly Optimized Algorithm For Continuous Intersection Join Queries Over Moving Objects, Rui Zhang, Jianzhong Qi, Dan Lin, Wei Wang, Raymond Chi Wing Wong Aug 2012

A Highly Optimized Algorithm For Continuous Intersection Join Queries Over Moving Objects, Rui Zhang, Jianzhong Qi, Dan Lin, Wei Wang, Raymond Chi Wing Wong

Computer Science Faculty Research & Creative Works

Given two sets of moving objects with nonzero extents, the continuous intersection joins query reports every pair of intersecting objects, one from each of the two moving object sets, for every timestamp. This type of queries is important for a number of applications, e. g., in the multi-billion-dollar computer game industry, massively multiplayer online games like World of Warcraft need to monitor the intersection among players' attack ranges and render players' interaction in real time. the computational cost of a straightforward algorithm or an algorithm adapted from another query type is prohibitive, and answering the query in real time poses …

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Common Ground Newsletter Summer 2012, Missouri University Of Science And Technology Aug 2012

Common Ground Newsletter Summer 2012, Missouri University Of Science And Technology

Common Ground

-Low-Impact Day
-Friendships and Fun!
-Kummer Student Design Center

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Gallium Containing Glass Polyalkenoate Anti-Cancerous Bone Cements: Glass Characterization And Physical Properties, A. W. Wren, A. Coughlan, L. Placek, Mark R. Towler Aug 2012

Gallium Containing Glass Polyalkenoate Anti-Cancerous Bone Cements: Glass Characterization And Physical Properties, A. W. Wren, A. Coughlan, L. Placek, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

A gallium (Ga) glass series (0.48SiO2-0.40ZnO-0.12CaO, with 0.08 mol% substitution for ZnO) was developed to formulate a Ga-containing Glass Polyalkenoate Cement (GPC) series. Network connectivity (NC) and X-ray Photoelectron Spectroscopy (XPS) was employed to investigate the role of Ga3+ in the glass, where it is assumed to act as a network modifier. Ga-GPC series was formulated with E9 and E11 polyacrylic acid (PAA) at 50, 55 and 60 wt% additions. E11 working times (Tw) ranged from 68 to 96 s (Lcon.) and 106 s for the Ga-GPCs (LGa-1 and LGa-2). Setting times (Ts) …

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Tinypack Xml: Real Time Xml Compression For Wireless Sensor Networks, Tommy Szalapski, Sanjay Madria, Mark Linderman Aug 2012

Tinypack Xml: Real Time Xml Compression For Wireless Sensor Networks, Tommy Szalapski, Sanjay Madria, Mark Linderman

Computer Science Faculty Research & Creative Works

Wireless networks possess significant limitations in bandwidth. Additionally, real-time networks cannot tolerate high latency. While some good XML compression algorithms exist, there remains a need for methods that reduce latency and bandwidth usage further in real time wireless applications. This paper presents a new compression scheme which reduces bandwidth while minimizing latency of XML data while in transit. XML structural data is reduced to format strings and arguments are sent as they are generated using modifications of real-time compression techniques specific to each data type. Methods are introduced to gracefully handle lost data in environments where delivery of all packets …

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Erratum: Triple Compton Effect: A Photon Splitting Into Three Upon Collision With A Free Electron (Physical Review Letters (2012) 108 (233201)), Erik Loetstedt, Ulrich D. Jentschura Aug 2012

Erratum: Triple Compton Effect: A Photon Splitting Into Three Upon Collision With A Free Electron (Physical Review Letters (2012) 108 (233201)), Erik Loetstedt, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

No abstract provided.

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Quantum Electrodynamic Corrections To The G Factor Of Helium P States, Mariusz Puchalski, Ulrich D. Jentschura Aug 2012

Quantum Electrodynamic Corrections To The G Factor Of Helium P States, Mariusz Puchalski, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

The Landég factor describes the response of an atomic energy level to an external perturbation by a uniform and constant magnetic field. In the case of many-electron systems, the leading term is given by the interaction μ B(L- +2S- )•B- , where L- and S- are the orbital and spin angular momentum operators, respectively, summed over all electrons. For helium, a long-standing experimental-theoretical discrepancy for P states motivates a re-evaluation of the higher order terms which follow from relativistic quantum theory and quantum electrodynamics (QED). The tensor structure of relativistic corrections involves scalar, vector, and symmetric and antisymmetric tensor …

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Percolation Transition In Quantum Ising And Rotor Models With Sub-Ohmic Dissipation, Manal Al-Ali, Jose Abel Hoyos, Thomas Vojta Aug 2012

Percolation Transition In Quantum Ising And Rotor Models With Sub-Ohmic Dissipation, Manal Al-Ali, Jose Abel Hoyos, Thomas Vojta

Physics Faculty Research & Creative Works

We investigate the influence of sub-Ohmic dissipation on randomly diluted quantum Ising and rotor models. The dissipation causes the quantum dynamics of sufficiently large percolation clusters to freeze completely. As a result, the zero-temperature quantum phase transition across the lattice percolation threshold separates an unusual super-paramagnetic cluster phase from an inhomogeneous ferromagnetic phase. We determine the low-temperature thermodynamic behavior in both phases, which is dominated by large frozen and slowly fluctuating percolation clusters. We relate our results to the smeared transition scenario for disordered quantum phase transitions, and we compare the cases of sub-Ohmic, Ohmic, and super-Ohmic dissipation.

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Composition-Dependent Oxygen Vacancy Formation In Multicomponent Wide-Band-Gap Oxides, Altynbek Murat, Julia E. Medvedeva Aug 2012

Composition-Dependent Oxygen Vacancy Formation In Multicomponent Wide-Band-Gap Oxides, Altynbek Murat, Julia E. Medvedeva

Physics Faculty Research & Creative Works

The formation and distribution of oxygen vacancy in layered multicomponent InAMO 4 oxides with A3 +=Al or Ga and M2 +=Ca or Zn and in the corresponding binary oxide constituents is investigated using first-principles density functional calculations. Comparing the calculated formation energies of the oxygen defect at six different site locations within the structurally and chemically distinct layers of InAMO 4 oxides, we find that the vacancy distribution is significantly affected not only by the strength of the metal-oxygen bonding, but also by the cation's ability to adjust to anisotropic oxygen environment created by the vacancy. In particular, …

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Conductivity Of Twin-Domain-Wall/Surface Junctions In Ferroelastics: Interplay Of Deformation Potential, Octahedral Rotations, Improper Ferroelectricity, And Flexoelectric Coupling, Eugene A. Eliseev, Anna N. Morozovska, Yijia Gu, Albina Borisevich, Long-Qing Chen, For Full List Of Authors, See Publisher's Website. Aug 2012

Conductivity Of Twin-Domain-Wall/Surface Junctions In Ferroelastics: Interplay Of Deformation Potential, Octahedral Rotations, Improper Ferroelectricity, And Flexoelectric Coupling, Eugene A. Eliseev, Anna N. Morozovska, Yijia Gu, Albina Borisevich, Long-Qing Chen, For Full List Of Authors, See Publisher's Website.

Materials Science and Engineering Faculty Research & Creative Works

Electronic and structural phenomena at the twin-domain-wall/surface junctions in the ferroelastic materials are analyzed. Carriers accumulation caused by the strain-induced band structure changes originated via the deformation potential mechanism, structural order parameter gradient, rotostriction, and flexoelectric coupling is explored. Approximate analytical results show that inhomogeneous elastic strains, which exist in the vicinity of the twin-domain-wall/surface junctions due to the rotostriction coupling, decrease the local band gap via the deformation potential and flexoelectric coupling mechanisms. This is the direct mechanism of the twin-wall static conductivity in ferroelastics and, by extension, in multiferroics and ferroelectrics. On the other hand, flexoelectric and rotostriction …

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Three-Body Dynamics In Single Ionization Of Atomic Hydrogen By 75 Kev Proton Impact, Aaron Laforge, Kisra Egodapitiya, Sachin Sharma, Michael Schulz Aug 2012

Three-Body Dynamics In Single Ionization Of Atomic Hydrogen By 75 Kev Proton Impact, Aaron Laforge, Kisra Egodapitiya, Sachin Sharma, Michael Schulz

Physics Faculty Research & Creative Works

We have measured and calculated doubly differential cross sections for ionization of atomic hydrogen using 75-keV proton impact for fixed projectile energy losses as a function of scattering angle.

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Projectile Coherence Effects In Electron Capture By Protons Colliding With H₂ And He, Sachin D. Sharma, Ahmad Hasan, Kisra N. Egodapitiya, T. P. Arthanayaka, G. Sakhelashvili, Michael Schulz Aug 2012

Projectile Coherence Effects In Electron Capture By Protons Colliding With H₂ And He, Sachin D. Sharma, Ahmad Hasan, Kisra N. Egodapitiya, T. P. Arthanayaka, G. Sakhelashvili, Michael Schulz

Physics Faculty Research & Creative Works

We have measured differential cross sections for single and dissociative capture for 25 and 75 keV protons colliding with H2 and He. Significant differences were found depending on whether the projectile beam was coherent or incoherent. For 75 keV p+H2 these differences can be mostly associated with molecular two-center interference and possibly some contributions from path interference. For 25 keV (both targets) they are mostly due to path interference between different impact parameters leading to the same scattering angles and, for the H2 target, possibly some contributions from molecular two-center interference.

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Adsorption Kinetics Of Pb(Ii) And Zn(Ii) Ions Unto Carbonized Groundnut Shells And Maize Cobs, Leke Luter, Aboi Julius, Henry T. Dekaa, B. A. Ikyenge, Ande Sesugh, Monday Uchenna Okoronkwo Aug 2012

Adsorption Kinetics Of Pb(Ii) And Zn(Ii) Ions Unto Carbonized Groundnut Shells And Maize Cobs, Leke Luter, Aboi Julius, Henry T. Dekaa, B. A. Ikyenge, Ande Sesugh, Monday Uchenna Okoronkwo

Chemical and Biochemical Engineering Faculty Research & Creative Works

Maize cobs and groundnut shell adsorbents from agricultural by-products were carbonized and investigated for adsorption of two selected metals, Lead (Pb II) and Zinc (Zn II) from aqueous solutions of these metals. Kinetic studies of the adsorption processes were investigated employing Elovich and the intraparticle diffussion models. The results showed that, the adsorption capacities of these comparatively cheaper adsorbents and their efficiency for the removal of Pb(II) and Zn(II) ions from aqueous solution present them suitable for use in place of the costly commercial activated carbons.

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Fall 2012 E-Certi Newsletter, Center For Educational Research And Teaching Innovation Aug 2012

Fall 2012 E-Certi Newsletter, Center For Educational Research And Teaching Innovation

CAFE Faculty Newsletters

Hello S&T instructors: The fall semester is here and with it a time of saying farewell to Vice Provost Harvest Collier. Read a tribute to him here. Also, read about how Hank Pernicka teaches rocket science and consistently garners teaching awards, plus, find out little known facts about S&T’s Woman of the Year and details of this year’s Curators’ Teaching Summit. Welcome back!

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Ais-Based Coordinated And Adaptive Control Of Generator Excitation Systems For An Electric Ship, Chuan Yan, Ganesh Kumar Venayagamoorthy, Keith Corzine Aug 2012

Ais-Based Coordinated And Adaptive Control Of Generator Excitation Systems For An Electric Ship, Chuan Yan, Ganesh Kumar Venayagamoorthy, Keith Corzine

Electrical and Computer Engineering Faculty Research & Creative Works

An artificial immune system (AIS)-Based control of generator excitation systems for the U.S. Navy's electric ship is presented in this paper to solve power quality problems caused by high-energy loads such as direct energy weapons. the coordinated development of the AIS controllers mainly consists of two parts innate immunity (optimal) and adaptive immunity. the parameters of the controllers for the former, to provide optimal performance, are determined simultaneously using particle swarm optimization. for dramatic changes in the ship's power system, adaptive control based on the immune system feedback law is developed. the feedback law adapts the controllers' parameters only during …

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Processes For The Production Of Buprenorphine With Reduced Impurity Formation, Brenda E. Allen, Esa T. Jarvi, Dennis J. Kaluta, James R. Meyer, Keith Tomazi, Anthony Mannino, Brian Orr Jul 2012

Processes For The Production Of Buprenorphine With Reduced Impurity Formation, Brenda E. Allen, Esa T. Jarvi, Dennis J. Kaluta, James R. Meyer, Keith Tomazi, Anthony Mannino, Brian Orr

Chemical and Biochemical Engineering Faculty Research & Creative Works

The present invention provides process for the production of opiate alkaloids. In particular, the present invention provides processes for the production of buprenorphine or a derivative of buprenorphine that minimizes the formation of impurities.

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The Min-Dist Location Selection Query, Jianzhong Qi, Rui Zhang, Lars Kulik, Dan Lin, Yuan Xue Jul 2012

The Min-Dist Location Selection Query, Jianzhong Qi, Rui Zhang, Lars Kulik, Dan Lin, Yuan Xue

Computer Science Faculty Research & Creative Works

We propose and study a new type of location optimization problem given a set of clients and a set of existing facilities, we select a location from a given set of potential locations for establishing a new facility so that the average distance between a client and her nearest facility is minimized. We call this problem the min-dist location selection problem, which has a wide range of applications in urban development simulation, massively multiplayer online games, and decision support systems. We explore two common approaches to location optimization problems and propose methods based on those approaches for solving this new …

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Parameterized Model Order Reduction Of Delayed Systems Using An Interpolation Approach With Amplitude And Frequency Scaling Coefficients, F. Ferranti, M. Nakhla, G. Antonini, T. Dhaene, L. Knockaert, Albert E. Ruehli Jul 2012

Parameterized Model Order Reduction Of Delayed Systems Using An Interpolation Approach With Amplitude And Frequency Scaling Coefficients, F. Ferranti, M. Nakhla, G. Antonini, T. Dhaene, L. Knockaert, Albert E. Ruehli

Electrical and Computer Engineering Faculty Research & Creative Works

When the geometric dimensions become electrically large or signal waveform rise times decrease, time delays must be included in the modeling. We present an innovative PMOR technique for neutral delayed differential systems, which is based on an efficient and reliable combination of univariate model order reduction methods, amplitude and frequency scaling coefficients and positive interpolation schemes. It is able to provide parameterized reduced order models passive by construction over the design space of interest. Pertinent numerical examples validate the proposed PMOR approach. © 2012 IEEE.

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Introduction Of R-Lcs And Comparative Analysis With Fsc And Mahalanobis-Taguchi Method For Breast Cancer Classification, Benjamin Daniels, Steven M. Corns, Elizabeth A. Cudney Jul 2012

Introduction Of R-Lcs And Comparative Analysis With Fsc And Mahalanobis-Taguchi Method For Breast Cancer Classification, Benjamin Daniels, Steven M. Corns, Elizabeth A. Cudney

Engineering Management and Systems Engineering Faculty Research & Creative Works

Classification for medical diagnosis is an important problem in the field of pattern recognition. We introduce a new method for classification based on repeated analysis of information tailored to small data sets - the Rote Learning Classifier System. using the Wisconsin Breast Cancer study, this method was compared to three other methods of classification: Mahalanobis-Taguchi Systems, Finite State Classifiers, and Neural Networks. It was found that for the given data set, the Rote Learning Classifier System outperformed the other methods of classification. This new algorithm correctly classified over 92% of the data set. © 2012 IEEE.

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A Master-Slave Soc Structure For Hmm Based Speech Recognition, Hui Geng, Yiyu Shi, Ming Dong, Runsheng Liu Jul 2012

A Master-Slave Soc Structure For Hmm Based Speech Recognition, Hui Geng, Yiyu Shi, Ming Dong, Runsheng Liu

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we propose a master-slave SoC structure composed of an ARM7-TDMI and a co-processor for Mahala Nobis distance calculation. the SoC was implemented on an Actel ProASIC series M7A3P1000 FPGA. Furthermore, we implement a HMM based speech recognition system based on this SoC. Compared with the conventional ASIC co-processor and slave SoC structure, the new master-slave structure reduces the number of SRAM access and improves the bus efficiency. Experiment results show that with 1.40s Chinese speech feixi and 24MHz clock, the processing time of the M-S SoC system is 1.85s, a 64.12% reduction compared with the software implement …

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Linear Precoding For Finite-Alphabet Signaling Over Mimome Wiretap Channels, Yongpeng Wu, Chengshan Xiao, Zhi Ding, Xiqi Gao, Shi Jin Jul 2012

Linear Precoding For Finite-Alphabet Signaling Over Mimome Wiretap Channels, Yongpeng Wu, Chengshan Xiao, Zhi Ding, Xiqi Gao, Shi Jin

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we investigate the secrecy rate of finite-alphabet communications over multiple-input-multiple-output-multiple-antenna eavesdropper (MIMOME) channels. Traditional precoding designs based on Gaussian input assumption may lead to substantial secrecy rate loss when the Gaussian input is replaced by practical finite-alphabet input. to address this issue, we investigate linear precoding designs to directly maximize the secrecy rate for MIMOME systems under the constraint of finite-alphabet input. by exploiting the theory of Karush-Kuhn-Tucker (KKT) analysis and matrix calculus, we first present necessary conditions of the optimal precoding design when instantaneous channel-state information (CSI) of the eavesdropper is known at the transmitter. in …

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Transition Of Deformation Behavior In An Ultrafine Grained Magnesium Alloy, S. K. Panigrahi, K. Kumar, N. Kumar, W. Yuan, R. S. Mishra, R. Delorme, B. Davis, R. A. Howell, K. Cho Jul 2012

Transition Of Deformation Behavior In An Ultrafine Grained Magnesium Alloy, S. K. Panigrahi, K. Kumar, N. Kumar, W. Yuan, R. S. Mishra, R. Delorme, B. Davis, R. A. Howell, K. Cho

Materials Science and Engineering Faculty Research & Creative Works

The deformation behavior of friction stirs processed magnesium alloy with average grain size ranging from 25 μm to 240 nm was studied. an evaluation of critical grain size for transition of deformation mode from twinning to slip was carried out by employing tensile and compressive tests. the role of critical grain size in transition of deformation behavior from strain hardening to softening was established. Inhomogeneous yielding was observed during tensile test of ultrafine-grained magnesium alloy below the critical grain size. © 2012 Elsevier B.V.

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High-Throughput Rear-Surface Drilling Of Microchannels In Glass Based On Electron Dynamics Control Using Femtosecond Pulse Trains, Lan Jiang, Pengjun Liu, Xueliang Yan, Ni Leng, Chuancai Xu, Hai Xiao, Yongfeng Lu Jul 2012

High-Throughput Rear-Surface Drilling Of Microchannels In Glass Based On Electron Dynamics Control Using Femtosecond Pulse Trains, Lan Jiang, Pengjun Liu, Xueliang Yan, Ni Leng, Chuancai Xu, Hai Xiao, Yongfeng Lu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This study proposes a rear-surface ablation enhancement approach to fabricate high-aspect-ratio microchannels by temporally shaping femtosecond laser pulse trains. in the case study of K9 glass, enhancements of up to a 56 times higher material removal rate and a three times greater maximum drilling depth are obtained by the proposed method, as compared with conventional femtosecond laser drilling at the same processing parameters. the improvements are due to the changes of photon-electron interactions by shaping femtosecond pulse train, which can effectively adjust the photon absorption and localized transient material properties by changing electron dynamics such as free electron densities. © …

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Timely Tidbits, Jul. 13, 2012, Library And Learning Resources Jul 2012

Timely Tidbits, Jul. 13, 2012, Library And Learning Resources

Timely Tidbits

No abstract provided.

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Effect Of Shock Front Geometry On Shock Depolarization Of Pb(Zr 0.52ti 0.48)O₃ Ferroelectric Ceramics, S. I. Shkuratov, Jason Baird, E. F. Talantsev Jul 2012

Effect Of Shock Front Geometry On Shock Depolarization Of Pb(Zr 0.52ti 0.48)O₃ Ferroelectric Ceramics, S. I. Shkuratov, Jason Baird, E. F. Talantsev

Mining Engineering Faculty Research & Creative Works

By use of experimentation, we detected a shock wave geometry effect on the depolarization of poled PbZr0.52Ti0.48)O3 Z(PZT 52/48) ferroelectrics. It follows from the experimental results that shock front geometry is one of key parameters in the shock depolarization of PZT 5248 ferroelectrics. This shock depolarization effect forms a fundamental limit to miniaturization of explosive-driven shock-wave ferroelectric generators (FEGs). Based on obtained experimental results, we developed miniature generators that reliably produce pulsed voltages exceeding 140 kV.

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Note: Utilizing Pb(Zr 0.95ti 0.05)O₃ Ferroelectric Ceramics To Scale Down Autonomous Explosive-Driven Shock-Wave Ferroelectric Generators, S. I. Shkuratov, Jason Baird, E. F. Talantsev Jul 2012

Note: Utilizing Pb(Zr 0.95ti 0.05)O₃ Ferroelectric Ceramics To Scale Down Autonomous Explosive-Driven Shock-Wave Ferroelectric Generators, S. I. Shkuratov, Jason Baird, E. F. Talantsev

Mining Engineering Faculty Research & Creative Works

Further miniaturization of recently designed autonomous ferroelectric generators (FEGs) S. I. Shkuratov, J. Baird, and E. F. Talantsev, Rev. Sci. Instrum. 82, 086107 (2011), which are based on the effect of explosive-shock-wave depolarization of poled ferroelectrics is achieved. The key miniaturization factor was the utilization of high-energy density Pb(Zr0.95Ti0.05)O3 (PZT 955) ferroelectric ceramics as energy-carrying elements of FEGs instead of the previously used Pb(Zr0.52Ti0.48)O3 (PZT 5248). A series of experiments demonstrated that FEGs based on smaller PZT 955 ferroelectric elements are capable of producing the same output voltage as those …

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Method For Producing Pressurelessly Sintered Zirconium Diboride/Silicon Carbide Composite Bodies, Shi C. Zhang, Greg Hilmas, William Fahrenholtz Jul 2012

Method For Producing Pressurelessly Sintered Zirconium Diboride/Silicon Carbide Composite Bodies, Shi C. Zhang, Greg Hilmas, William Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

A method of sintering a ZrB2-SiC composite body at ambient pressures, including blending a first predetermined amount of ZrB2 powder with a second predetermined amount of SiC powder, wherein both powders are characterized by the presence of surface oxide impurities. Next the blended powders are mixed to yield a substantially homogeneous powder mixture and a portion of the substantially homogeneous powder mixture is formed into a green body. The body is fired to a first temperature, wherein substantially all surface oxide impurities are reduced and/or volatilized to substantially eliminate oxides from the green body, and the body …

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