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2002

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Articles 181 - 210 of 3435

Full-Text Articles in Physical Sciences and Mathematics

Detection And Analysis Of Sec1 Immunological Reaction By Afm And Electrochemical Method, Sa-Ying Dong, Hong-Ren Wang Nov 2002

Detection And Analysis Of Sec1 Immunological Reaction By Afm And Electrochemical Method, Sa-Ying Dong, Hong-Ren Wang

Journal of Electrochemistry

The goals of this work were to demonstrate the ability of atomic force microscopy (AFM) to detect various immunological processes between antibodies and antigens.A sensor was designed by covalently linking the antibody of staphylococcal enterotoxin Cl (SEC1) on the self-assembled gold surface. This sensor permitted detection of antibody-antigen recognition events which were highly correlated with the topography under different conditions. The statistic data of AFM were analysed. As control experiments, nonspecific antigens and lower concentration SEC1 antigens were directly observed. In addition, an acidic solution was used to break the antigen-antibody pair and made the sensor reuse. Electrochemical evidence was …


Theoretical Issues In The Economics Of International Trade And Environment., Meeta Keswani Mehra Dr. Nov 2002

Theoretical Issues In The Economics Of International Trade And Environment., Meeta Keswani Mehra Dr.

Doctoral Theses

In the wake of substantial trade liberalization in the world economy over the last two decades and growing environmental consciousness, the issues of the impacts of international goods trade and foreign direct investment (FDI) on local and global environment are becoming increasingly contentious. Whilst trade and FDI have been said to bring higher incomes and well-being for all, these are seen to act as "magnifiers" of environmental deterioration - especially in the developing countries. On the other hand, growing environmentalism is perceived to act as an impediment to freer trade and investment flows across countries. Hence, the central issues are …


Nano-Sized Cobalt-Based Oxides As Negative Electrode For Lithium-Ion Batteries, Feng Huang, Zheng-Yong Yuan, Yun-Hong Zhou, Ju-Tang Sun Nov 2002

Nano-Sized Cobalt-Based Oxides As Negative Electrode For Lithium-Ion Batteries, Feng Huang, Zheng-Yong Yuan, Yun-Hong Zhou, Ju-Tang Sun

Journal of Electrochemistry

Nanosized cobalt-based oxide (Co 3O 4, CoB 1.36 O 2.8 and CoB 0.5 Al 0.1 O 1.5 ) samples were prepared by rheological phase method and were tested as anodes in secondary lithium batteries. The cells were cycled between 0.01V and 3.00 V. The best electrochemical performance was obtained from the Li/Co 3O 4 cell, which retained 95% of its initial capacity (931 mAh/g) after 30 cycles. The doping of B, Al reduced the reversible capacity during the first discharge/charge cycle, and the quantity of reversible capacity reduced with B, A1 increasing. The modifying structures at difference charge and discharge …


Mechanistic Study Of Oxidation Of Hypophosphite On Pt Electrodes By Sniftirs, Tai-Xiang Jiang, Hui-Huang Wu Nov 2002

Mechanistic Study Of Oxidation Of Hypophosphite On Pt Electrodes By Sniftirs, Tai-Xiang Jiang, Hui-Huang Wu

Journal of Electrochemistry

The oxidation of hypophosphite on a polycrystalline platinum electrode was studied by SNIFTIRS and cyclic voltammetry, the in-situ IR spectra were analyzed as a function of Pt electrode potentials in the solution of 0.5 mol/L H 2SO 4+0.1 mol/L NaH 2PO 2. It was found that the dissociative adsorption of hypophosphite ions occurs on Pt surface, and the oxidation product is H 3PO 4, rather than H 2PO 3 - which was considered to produce on Ni electrodes, thereby a new insight into mechanism of hypophosphite oxidation on Pt in acidic media was provided.


Effect Of Dissolved Oxygen On The Corrosion Behavior Of Coalesced Copper And Stainless Steel-206 In Acetic Solutions, Rong-Zong Hu, Xiong-Cao Zhao, Yu-Hua Weng, Chang-Jian Lin Nov 2002

Effect Of Dissolved Oxygen On The Corrosion Behavior Of Coalesced Copper And Stainless Steel-206 In Acetic Solutions, Rong-Zong Hu, Xiong-Cao Zhao, Yu-Hua Weng, Chang-Jian Lin

Journal of Electrochemistry

Linear sweeping technique and dissolving oxygen sensor were used to study the effect of dissolved oxygen and relating factors on the corrosion behavior of coalesced copper and stainless steel-206 in acetic solutions. It was found: 1. The existing of dissolved oxygen is one of the important factors, which strongly influenced the corrosion behavior of coalesced copper and stainless steel-206 in acetic solution. 2. The existing of dissolved oxygen is benefitial to the preventing stainless steel-206 from corrosion in acetic solutions, but damage to the preventing coalesced copper from corrosion. 3. At the high temperature since the dissolved oxygen was escaping …


Improvement Of The Low Temperature Electrochemical Performance Of Ab_5-Type Hydrogen Storage Alloy, Hui Ye, Zhu Wu, Zhi-Lin Li, Hong Zhang Nov 2002

Improvement Of The Low Temperature Electrochemical Performance Of Ab_5-Type Hydrogen Storage Alloy, Hui Ye, Zhu Wu, Zhi-Lin Li, Hong Zhang

Journal of Electrochemistry

Optimizing the rare earth composition and doping with boron have been used to improve the low temperature performance of AB 5 hydrogen storage alloy.The results show that Ce-rich alloy with a proper amount of boron is suitable for Ni/MH battery with the lower-limit temperature down to 238 K under smaller current density (120 mA/g). The improvement of low temperature performance of hydrogen storage alloy is well consistent with its microstructure,thermodynamic and kinetic properties.


An Investigation On Microstructure And Performance Of The Recasting Perfluorosulfonated Membrane, Feng-Ling Liu, Rong Zeng, Pei-Jin Li, Pin-Qing Wang, Chang-Hong Zhao Nov 2002

An Investigation On Microstructure And Performance Of The Recasting Perfluorosulfonated Membrane, Feng-Ling Liu, Rong Zeng, Pei-Jin Li, Pin-Qing Wang, Chang-Hong Zhao

Journal of Electrochemistry

The microsturcture and performance of the recasting perfluorosulfonated membrane were investigated by comparison with Nafion . The results indicated that although chemical components of the recasting membrane FYM1150 kept the same as Nafion , the dry FYM1150 differed from dry Nafion  membrane in structure, the former possessed some small pores which are not through-holes having a diameter of 50~300 nm while the latter had almost no pores; The mechanical properties of the FYM1150 were better than those of Nafion ; The discharge performance at high current density of MEA using FYM1150 membrane as an electrolyte was also better than …


Searches For Excited Fermions In Ep Collisions At Hera, S. Chekanov, M. Derrick, D. Krakauer, S. Magill, B. Musgrave, A. Pellegrino, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Levi, A. Margotti, T. Massam, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli Nov 2002

Searches For Excited Fermions In Ep Collisions At Hera, S. Chekanov, M. Derrick, D. Krakauer, S. Magill, B. Musgrave, A. Pellegrino, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Levi, A. Margotti, T. Massam, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli

Faculty Publications

Searches in ep collisions for heavy excited fermions have been performed with the ZEUS detector at HERA. Excited states of electrons and quarks have been searched for in e+ p collisions at a centre-of-mass energy of 300 GeV using an integrated luminosity of 47.7 pb-1. Excited electrons have been sought via the decays e± → eγ, e± → eZ and e± → vW. Excited quarks have been sought via the decays q± → qγ and q± → qW. A search for excited neutrinos decaying via v± → vγ, v± → vZ and v± → eW is presented using e-p collisions …


Preparation And Performance Of Lifeo_2 Coated Nickel Oxide Cathode For Molten Carbonate Fuel Cells, Chun-Ming Wang, Fei Li, Ke-Ao Hu Nov 2002

Preparation And Performance Of Lifeo_2 Coated Nickel Oxide Cathode For Molten Carbonate Fuel Cells, Chun-Ming Wang, Fei Li, Ke-Ao Hu

Journal of Electrochemistry

A novel cathode for molten carbonate fuel cells was prepared by coating LiFeO 2 over the surface of porous NiO cathode by a simple combustion process. The analytical results of X-ray diffraction (XRD), energy dispersive analysis of X-ray (EDAX), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated that the LiFeO 2 coating on the surface of NiO particles consisted of nonometer-sized LiFeO 2 grains and sintered tightly with the NiO particles. The LiFeO 2 coating dramatically reduced the contacting area of NiO with the carbonate melts, thus the solubility of NiO in the carbonate melts was decreased. Meanwhile, …


Electrocatalytic Oxidation Of Formic Acid On Molybdate-Modified Platinum Electrode, Jun-Hua Du, Xue-Hui Xu, Hong Li, Hong-Yu Cheng, Wei-Shan Li Nov 2002

Electrocatalytic Oxidation Of Formic Acid On Molybdate-Modified Platinum Electrode, Jun-Hua Du, Xue-Hui Xu, Hong Li, Hong-Yu Cheng, Wei-Shan Li

Journal of Electrochemistry

The electrochemical behavior of molybdates on a platinum electrode in H 2SO 4 solutions with different H 2SO 4 concentrations was studied by cyclic voltammetry and double chronoamperometry. Molybdates were reduced to adsorb hydrogen molybdenum bronzes on the platinum electrode in H 2SO 4 solutions during cathodically potential sweep. The hydrogen molybdenum bronzes were oxidized to different forms of hydrogen molybdenum bronzes with less hydrogen, depending on the H 2SO 4 concentration. Platinum electrode was modified by these hydrogen molybdenum bronzes. However, this modified electrode was not stable in H 2SO 4 solutions. The modified electrode was used to study …


The Galois Correspondence For Branched Covering Spaces And Its Relationship To Hecke Algebras, Matthew Ong Nov 2002

The Galois Correspondence For Branched Covering Spaces And Its Relationship To Hecke Algebras, Matthew Ong

Mathematical Sciences Technical Reports (MSTR)

There is a very beautiful correspondence between branched covers of the Riemann sphere P1 and subgroups of the fundamental group π1(P1 − {branch points}), exactly analogous to the correspondence between subfields of an algebraic extension E/F and subgroups of the Galois group Gal(E/F). This paper explores the concept of a Hecke algebra, which in this context is a generalization of the Galois group to the case of non- Galois covers S/P1. Specifically, we show that the isomorphism type of a Hecke algebra C[H\G/H] is completely determined by the decomposition of …


Analysis Of Longitudinal Marginal Structural Models , Jennifer F. Bryan, Zhuo Yu, Mark J. Van Der Laan Nov 2002

Analysis Of Longitudinal Marginal Structural Models , Jennifer F. Bryan, Zhuo Yu, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

In this article we construct and study estimators of the causal effect of a time-dependent treatment on survival in longitudinal studies. We employ a particular marginal structural model (MSM), and follow a general methodology for constructing estimating functions in censored data models. The inverse probability of treatment weighted (IPTW) estimator is used as an initial estimator and the corresponding treatment-orthogonalized, one-step estimator is consistent and asymptotically linear when the treatment mechanism is consistently estimated. We extend these methods to handle informative censoring. A simulation study demonstrates that the the treatment-orthogonalized, one-step estimator is superior to the IPTW estimator in terms …


Land-Cover Detection And Landscape Structure Analysis In The Pachitea Basin, Peruvian Amazon, Daniel Gann Nov 2002

Land-Cover Detection And Landscape Structure Analysis In The Pachitea Basin, Peruvian Amazon, Daniel Gann

FIU Electronic Theses and Dissertations

Classification procedures, including atmospheric correction satellite images as well as classification performance utilizing calibration and validation at different levels, have been investigated in the context of a coarse land-cover classification scheme for the Pachitea Basin. Two different correction methods were tested against no correction in terms of reflectance correction towards a common response for pseudo-invariant features (PIF). The accuracy of classifications derived from each of the three methods was then assessed in a discriminant analysis using crossvalidation at pixel, polygon, region, and image levels. Results indicate that only regression adjusted images using PIFs show no significant difference between images in …


Proofs Of Soundness And Strong Normalization For Linear Memory Types, Heng Huang, Chris Hawblitzel Nov 2002

Proofs Of Soundness And Strong Normalization For Linear Memory Types, Heng Huang, Chris Hawblitzel

Computer Science Technical Reports

Efficient low-level systems need more control over memory than safe high-level languages usually provide. As a result, run-time systems are typically written in unsafe languages such as C. This report describes an abstract machine designed to give type-safe code more control over memory. It includes complete definitions and proofs.


Routing In Mobile Ad Hoc Networks With Global Knowledge, D. Platt Nov 2002

Routing In Mobile Ad Hoc Networks With Global Knowledge, D. Platt

Faculty of Informatics - Papers (Archive)

This paper describes a method of routing in mobile ad hoc networks. The problem is exacerbated by the fact that the radio links between the nodes of the network are continually being made and broken. The method consists of using the known connections to construct a "map" of the network which is intended to reproduce the geographical layout of the network at any time. An algorithm is described which finds a route from one node to another by always attempting to move geographically closer to the destination at every hop. This produces nearly optimal performance with very short computation time. …


Improved Utilisation In Ip Networks Using Multiple Path Routing, D. Platt Nov 2002

Improved Utilisation In Ip Networks Using Multiple Path Routing, D. Platt

Faculty of Informatics - Papers (Archive)

This paper considers routing in an IP network running a routing protocol such as OSPF It takes as a benchmark a routing scheme. which computes a single lowest cost path between every source/destination pair. It proposes two more schemes which each generate two routes for each source/destination pair. The second scheme uses the present lowest cost route and the previous lowest cost route, different from the present one. The third scheme uses the present lowest cost route and re-computes a route by removing all the links used in the first route and using the Dijkstra algorithm. A number of tests …


Ecotones: The Heartbeat Of Huxley, 2002, Fall, Issue 08, Laurel Eddy, Huxley College Of The Environment, Western Washington University Nov 2002

Ecotones: The Heartbeat Of Huxley, 2002, Fall, Issue 08, Laurel Eddy, Huxley College Of The Environment, Western Washington University

Historical Collection of Huxley Newsletters

No abstract provided.


Heterojunction Diode Fabrication From Polyaniline And A Ferroelectric Polymer, B Xu, Y. Ovchenkov, Mengjun Bai, A. N. Caruso, A.V. Sorokin, Stephen Ducharme, Bermard Doudin, Peter A. Dowben Nov 2002

Heterojunction Diode Fabrication From Polyaniline And A Ferroelectric Polymer, B Xu, Y. Ovchenkov, Mengjun Bai, A. N. Caruso, A.V. Sorokin, Stephen Ducharme, Bermard Doudin, Peter A. Dowben

Peter Dowben Publications

We have fabricated a p – n heterojunction diode by vapor depositing a thin film of polyaniline on top of the crystalline copolymer: poly(vinylidene fluoride with trifluoroethylene). The formation of a diode is expected from the band offsets of the two polymers near the Fermi level. The interface between the two components was investigated, and an abrupt interface was found that is very different from the inorganic analog.


Cross Section For Forward J/Ψ Production In Pp̅ Collisions At √S=1.8 Tev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Nov 2002

Cross Section For Forward J/Ψ Production In Pp̅ Collisions At √S=1.8 Tev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

The inclusive cross section for J/ψ production times the branching ratio B(J/ψ→μ+μ-) has been measured in the forward pseudorapidity region: B×dσ[+p→J/ψ(pT>10 GeV/c,2.1<|η|<2.6)+X]/dη=192±9(stat)±29(syst) pb. The results are based on 74.1±5.2 pb-1 of data collected by the CDF Collaboration at the Fermilab Tevatron Collider. The measurements extend earlier measurements of the D0 Collaboration to higher pTJ/ψ. In the kinematic range where the experiments partially overlap, these data are in good agreement with previous measurements.


A Convenient One-Pot, Organoaluminum Mediated Vinylsilane Synthesis From Non-Enolizable Ketones Via The Peterson Protocol, Man Lung Kwan, Merle Battiste Nov 2002

A Convenient One-Pot, Organoaluminum Mediated Vinylsilane Synthesis From Non-Enolizable Ketones Via The Peterson Protocol, Man Lung Kwan, Merle Battiste

Man Lung Desmond Kwan

Vinylsilanes serve as convenient vinyl anion equivalents which have gained popularity over decades. A variety of non-enolizable aromatic ketones are converted to the corresponding vinylsilanes in a one-pot procedure involving the addition of (trimethylsilylmethyl)lithium to aromatic ketones followed by addition of diethylaluminum chloride and then small amounts of water. Halide and alkoxide substituents are tolerated, and this trans-stereoselective (broad generalization; the most sterically bulky group on the double bond is trans to the trimethylsilyl group) reaction affords vinylsilanes in good yield.


Monte Carlo Simulation Of Vapor–Liquid Binodal Of Water, S. Yoo, Xiao Cheng Zeng Nov 2002

Monte Carlo Simulation Of Vapor–Liquid Binodal Of Water, S. Yoo, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Among many popular potential models of water, the nonpolarizable four-site TIP4P potential is one of the more widely used. Recently, two new potential models of water on the basis of the TIP4P potential have been developed. One is the four-site Dang–Chang polarizable potential and another is the five-site TIP5P potential. The former is designed to describe not only bulk and interfacial properties of liquid water but also microclusters of water. The nonpolarizable TIP5P potential is the latest version in the TIP series from the Jorgensen group. Compared with the TIP4P potential, for example, the TIP5P potential gives a much improved …


Q2 Evolution Of The Generalized Gerasimov-Drell-Hearn Integral For The Neutron Using A 3He Target, M. Amarian, L. Auerbach, T. Avertett, J. Berthot, P. Bertin, W. Bertozzi, T. Black, E. Brash, D. Brown, E. Burtin, J. R. Calarco, G. D. Cates, Z. Chai, J. P. Chen, Seonho Choi, E. Chudakov, E. Cisbani, C. W. De Jager, A. Deur, R. Disalvo, S. Dieterich, P. Djawotho, M. Finn, K. Fissum, H. Fovieille, S. Frullani, H. Gao, J. Gao, F. Garibaldi, A. Gasparian, S. Gilad, R. Gilman, A. Glamazdin, C. Glashausser, E. Goldberg, J. Gomez, V. Gorbenko, J. O. Hansen, F. W. Hersman, R. Holmes, G. M. Huber, E. W. Hughes, T. B. Humensky, S. Incerti, M. Iodice, S. Jensen, X. Jiang, C. Jones, G. M. Jones, M. Jones, C. Jutier, A. Ketikyan, I. Kominis, W. Korsch, K. Kramer, K. S. Kumar, G. Kumbartzki, M. Kuss, Enkeleida K. Lakuriqi, G. Laveissiere, J. Lerose, M. Liang, N. Liyanage, G. Lolos, S. Mavlov, J. Marroncle, K. Mccormick, R. Mckeown, Z. E. Meziani, R. Michaels, J. Mitchell, Z. Papandreou, T. Pavlin, G. G. Petratos, D. Pripstein, D. Prout, R. Ransome, Y. Roblin, D. Rowntree, M. Rvachev, F. Sabatie, A. Saha, K. Slifer, P. A. Souder, T. Saito, S. Strauch, R. Suleiman, K. Takahashi, S. Teijiro, L. Todor, H. Tsubota, H. Ueno, G. Urciuoli, R. Van De Meer, P. Vernin, H. Voskanian, B. Wojtsekhowski, F. Xiong, W. Xu, J. C. Yang, B. Zhang, P. Zolnierczuk Nov 2002

Q2 Evolution Of The Generalized Gerasimov-Drell-Hearn Integral For The Neutron Using A 3He Target, M. Amarian, L. Auerbach, T. Avertett, J. Berthot, P. Bertin, W. Bertozzi, T. Black, E. Brash, D. Brown, E. Burtin, J. R. Calarco, G. D. Cates, Z. Chai, J. P. Chen, Seonho Choi, E. Chudakov, E. Cisbani, C. W. De Jager, A. Deur, R. Disalvo, S. Dieterich, P. Djawotho, M. Finn, K. Fissum, H. Fovieille, S. Frullani, H. Gao, J. Gao, F. Garibaldi, A. Gasparian, S. Gilad, R. Gilman, A. Glamazdin, C. Glashausser, E. Goldberg, J. Gomez, V. Gorbenko, J. O. Hansen, F. W. Hersman, R. Holmes, G. M. Huber, E. W. Hughes, T. B. Humensky, S. Incerti, M. Iodice, S. Jensen, X. Jiang, C. Jones, G. M. Jones, M. Jones, C. Jutier, A. Ketikyan, I. Kominis, W. Korsch, K. Kramer, K. S. Kumar, G. Kumbartzki, M. Kuss, Enkeleida K. Lakuriqi, G. Laveissiere, J. Lerose, M. Liang, N. Liyanage, G. Lolos, S. Mavlov, J. Marroncle, K. Mccormick, R. Mckeown, Z. E. Meziani, R. Michaels, J. Mitchell, Z. Papandreou, T. Pavlin, G. G. Petratos, D. Pripstein, D. Prout, R. Ransome, Y. Roblin, D. Rowntree, M. Rvachev, F. Sabatie, A. Saha, K. Slifer, P. A. Souder, T. Saito, S. Strauch, R. Suleiman, K. Takahashi, S. Teijiro, L. Todor, H. Tsubota, H. Ueno, G. Urciuoli, R. Van De Meer, P. Vernin, H. Voskanian, B. Wojtsekhowski, F. Xiong, W. Xu, J. C. Yang, B. Zhang, P. Zolnierczuk

Enkeleida K. Lakuriqi

We present data on the inclusive scattering of polarized electrons from a polarized 3He target at energies from 0.862 to 5.06 GeV, obtained at a scattering angle of 15.5°.Our data include measurements from the quasielastic peak, through the nucleon resonance region, and beyond, and were used to determine the virtual photon cross-section difference σ1/2-σ3/2. We extract the extended Gerasimov-Drell-Hearn integral for the neutron in the range of four-momentum transfer squared Q2 of 0.1-0.9 GeV2.


Oral History Interview With Laszlo A. Belady, Philip L. Frana Nov 2002

Oral History Interview With Laszlo A. Belady, Philip L. Frana

Philip L Frana

Belady discusses his early life and education in Hungary, escape to West Germany during the 1956 revolution, and work as a draftsman at Ford Motor Company in Cologne and as an aerodynamics engineer at Dassault in Paris. Belady covers his 1961 immigration into the United States, where he joined International Business Machines and did early work in operating systems, virtual machine architectures, program behavior modeling, memory management, computer graphics, Asian character sets, and data security. He also ...


Stripes From (Noncommutative) Stars, Simon Catterall, J. Ambjorn Nov 2002

Stripes From (Noncommutative) Stars, Simon Catterall, J. Ambjorn

Physics - All Scholarship

We show that lattice regularization of noncommutative field theories can be used to study non-perturbative vacuum phases. Specifically we provide evidence for the existence of a striped phase in two-dimensional noncommutative scalar field theory


A Proof-Of-Principle Experiment Of Optical Injection Of Electrons In Laser-Driven Plasma Waves, N. Saleh, P. Zhang, Shouyuan Chen, Z.-M. Sheng, Anatoly Maksimchuk, V. Yanovsky, Donald P. Umstadter Nov 2002

A Proof-Of-Principle Experiment Of Optical Injection Of Electrons In Laser-Driven Plasma Waves, N. Saleh, P. Zhang, Shouyuan Chen, Z.-M. Sheng, Anatoly Maksimchuk, V. Yanovsky, Donald P. Umstadter

Donald Umstadter Publications

We report on a proof-of-principle experiment that demonstrates, for the first time, the feasibility of optically injecting electrons into laser-driven plasma waves, first proposed by [D. Umstadter, J.-K. Kim, and E. Dodd, Phys. Rev. Lett. 76, 2073 (1996)l. Using a Table-Top-Tera Watt laser system (I ~5x1018 W/cm2, λ = 1 μm, τ = 400 fs), whose output beam is split by 1:4 ratio into a pump and injection beams, respectively, spatial (within 10 μm) and temporal (within 400 fs) overlap of the two beams were achieved by intersecting them orthogonally in an under-dense (~ 4x1019 cm …


Exact Formulae For The Lovasz Theta Function Of Sparse Circulant Graphs, Valentino Crespi Nov 2002

Exact Formulae For The Lovasz Theta Function Of Sparse Circulant Graphs, Valentino Crespi

Computer Science Technical Reports

The Lovasz theta function has attracted a lot of attention for its connection with diverse issues, such as communicating without errors and computing large cliques in graphs. Indeed this function enjoys the remarkable property of being computable in polynomial time, despite being sandwitched between clique and chromatic number, two well known hard to compute quantities. In this paper I provide a closed formula for the Lovasz function of a specific class of sparse circulant graphs thus generalizing Lovasz results on cycle graphs (circulant graphs of degree 2).


Study Of Energetic Ion Generation From High-Intensity-Laser Dense-Plasma Interactions, K. Flippo, Anatoly Maksimchuk, Sudeep Banerjee, K. Nash, V. Wong, T. Lin, K. Nemoto, V. Yu. Bychenkov, Y. Sentoku, G. Mourou, Donald P. Umstadter Nov 2002

Study Of Energetic Ion Generation From High-Intensity-Laser Dense-Plasma Interactions, K. Flippo, Anatoly Maksimchuk, Sudeep Banerjee, K. Nash, V. Wong, T. Lin, K. Nemoto, V. Yu. Bychenkov, Y. Sentoku, G. Mourou, Donald P. Umstadter

Donald Umstadter Publications

We report on the characteristics of an ultrafast-laser driven proton beam from thinfilm targets. The difference in proton beam profiles, beam energies, and laser induced back ablation plumes between a dielectric (Mylar) and a conductor (aluminum) are discussed. Evidence for front-side acceleration and a method for beam manipulation are also presented.


Developments In Relativistic Nonlinear Optics, Donald P. Umstadter, Sudeep Banerjee, Shouyuan Chen, E. Dodd, K. Flippo, Anatoly Maksimchuk, N. Saleh, A. Valenzuela, P. Zhang Nov 2002

Developments In Relativistic Nonlinear Optics, Donald P. Umstadter, Sudeep Banerjee, Shouyuan Chen, E. Dodd, K. Flippo, Anatoly Maksimchuk, N. Saleh, A. Valenzuela, P. Zhang

Donald Umstadter Publications

We report recent results of experiments and simulations in the regime of peak laser intensities above 1019 W/cm2, including the following topics: (1) electron and proton acceleration to energies in excess of 10 MeV in well collimated beams; (2) use of laser chirp to control the growth of plasma waves and acceleration of electrons by the Raman instability; (3) all optical injection and acceleration of electrons; (4) relativistic self-focusing by means of the mutual index of refraction of two overlapping laser pulses; (5) creation of a radioisotope by the reaction 10B(d,n)11C; (6) …


The Tev Spectrum Of H1426+428, P. T. Reynolds, Et. Al. Nov 2002

The Tev Spectrum Of H1426+428, P. T. Reynolds, Et. Al.

Physical Sciences Publications

The BL Lac object H1426+428 was recently detected as a high-energy γ-ray source by the VERITAS collaboration (Horan et al.). We have reanalyzed the 2001 portion of the data used in the detection in order to examine the spectrum of H1426+428 above 250 GeV. We find that the time-averaged spectrum agrees with a power law of the shape






The statistical evidence from our data for emission above 2.5 TeV is 2.6 σ. At the 95% confidence level, the integral flux of H1426+428 above 2.5 TeV is larger than 3% of the corresponding flux from the Crab Nebula. The spectrum is …


Synthesis Of A Spacer-Armed Disulfated Tetrasaccharide Of Sb1a, A Carbohydrate Hapten Associated With Human Hepatocellular Carcinoma, Qin Li, Hui Li, Qing Li, Qing Hua Lou, Bin Su, Meng Shen Cai, Zhong Jun Li Nov 2002

Synthesis Of A Spacer-Armed Disulfated Tetrasaccharide Of Sb1a, A Carbohydrate Hapten Associated With Human Hepatocellular Carcinoma, Qin Li, Hui Li, Qing Li, Qing Hua Lou, Bin Su, Meng Shen Cai, Zhong Jun Li

Chemistry Faculty Publications

A disulfated tetrasaccharide fragment with a spacer arm of human hepatocellular carcinoma carbohydrate antigen SB1a, namely, 2-aminoethyl 3-O-sulfo-β-d-galactopyranosyl-(1→3)-2-acetamido-2-deoxy-β-d-galactopyranosyl-(1→4)-3-O-sulfo-β-d-galactopyranosyl-(1→4)-β-d-glucopyranoside was synthesized via a [2+1+1] block building mode. In the last coupling step toward the trisaccharide acceptor 8, benzoyl protected galactosyl bromide donor 14 was found to be much more reactive than the acetyl-protected donors. A disulfated tetrasaccharide fragment with a spacer arm of human hepatocellular carcinoma carbohydrate antigen SB1a was synthesized via a [2+1+1] block building mode.