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Measurement Of Dijet Cross Sections For Events With A Leading Neutron In Photoproduction At Hera, J. Breitweg, S. Chekanov, M. Derrick, D. Krakauer, S. Magill, B. Musgrave, A. Pellegrino, J. Repond, R. Stanek, 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 Feb 2001

Measurement Of Dijet Cross Sections For Events With A Leading Neutron In Photoproduction At Hera, J. Breitweg, S. Chekanov, M. Derrick, D. Krakauer, S. Magill, B. Musgrave, A. Pellegrino, J. Repond, R. Stanek, 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

Faculty Publications

Differential cross sections for dijet photoproduction in association with a leading neutron using the reaction e+ + p → e+ + n + jet + jet + Xr have been measured with the ZEUS detector at HERA using an integrated luminosity of 6.4 pb-1. The fraction of dijet events with a leading neutron in the final state was studied as a function of the jet kinematic variables. The cross sections were measured for jet transverse energies EjetT > 6 GeV, neutron energy En > 400 GeV, and neutron production angle θn < 0.8 mrad. The data are broadly consistent with factorization of the lepton and hadron vertices and with a simple one-pion-exchange model. © 2001 Elsevier Science B.V. All rights reserved.

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A Note On Doubles Of Groups, Nadia Benakli, Oliver T. Dasbach, Yair Glasner, Brian Mangum Feb 2001

A Note On Doubles Of Groups, Nadia Benakli, Oliver T. Dasbach, Yair Glasner, Brian Mangum

Faculty Publications

Recently, Rips produced an example of a double of two free groups which has unsolvable generalized word problem. In this paper, we show that Rips's example fits into a large class of doubles of groups, each member of which contains F2×F2 and therefore has unsolvable generalized word problem and is incoherent. © 2001 Elsevier Science B.V.

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Neutrino Reactions On The Deuteron, S. Nakamura, T. Sato, Vladimir Gudkov, K. Kubodera Feb 2001

Neutrino Reactions On The Deuteron, S. Nakamura, T. Sato, Vladimir Gudkov, K. Kubodera

Faculty Publications

The cross sections for the ν-d and ν̅ -d reactions are calculated for incident energy up to Eν=170 MeV with the use of a phenomenological Lagrangian approach. We assess and improve the reliability of the employed calculational method by examining the dependence of the results on various input and approximations that go into the calculation. The main points of improvement over the existing work are (1) use of the “modern” NN potentials, (2) use of the more accurate nucleon weak-interaction form factors, and (3) monitoring the strength of a vertex that governs the exchange-current contribution, with the use …

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Diamagnetic Persistent Current In Diffusive Normal-Metal Rings, E. M.Q. Jariwala, P. Mohanty, M. B. Ketchen, Richard A. Webb Feb 2001

Diamagnetic Persistent Current In Diffusive Normal-Metal Rings, E. M.Q. Jariwala, P. Mohanty, M. B. Ketchen, Richard A. Webb

Faculty Publications

We have measured a diamagnetic persistent current with flux periodicities of both h/e and h/2e in an array of thirty diffusive mesoscopic gold rings. At the lowest temperatures, the magnitudes of the currents per ring corresponding to the h/e- and h/2e-periodic responses are both comparable to the Thouless energy Ec≡ħ/τD, where τD is the diffusion time. Taken in conjunction with earlier experiments, our results strongly challenge the conventional theories of persistent current. We consider a new approach associated with the saturation of …

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Process For Immobilizing Waste Using Bagasse (Us Patent 6174275), Michael A. Janusa Jan 2001

Process For Immobilizing Waste Using Bagasse (Us Patent 6174275), Michael A. Janusa

Faculty Publications

No abstract provided.

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Semiclassical Application Of The Mo”Ller Operators In Reactive Scattering, Sophya Garashchuk, John C. Light Jan 2001

Semiclassical Application Of The Mo”Ller Operators In Reactive Scattering, Sophya Garashchuk, John C. Light

Faculty Publications

Mo\ller operators in the formulation of reaction probabilities in terms of wave packet correlation functions allow us to define the wave packets in the interaction region rather than in the asymptotic region of the potential surface. We combine Mo\ller operators with the semiclassical propagator of Herman and Kluk. This does not involve further approximations and can be used with any initial value representation (IVR) semiclassical propagator. Time propagation in asymptotic regions of the potential due to Mo\ller operators reduces the oscillations of the propagator integrand and improves convergence of the results with respect to the number of trajectories. The effectiveness …

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An Ellam Scheme For Multidimensional Advection-Reaction Equations And Its Optimal-Order Error Estimate, Hong Wang, Xiquan Shi, Richard E. Ewing Jan 2001

An Ellam Scheme For Multidimensional Advection-Reaction Equations And Its Optimal-Order Error Estimate, Hong Wang, Xiquan Shi, Richard E. Ewing

Faculty Publications

We present an Eulerian-Lagrangian localized adjoint method (ELLAM) scheme for initial-boundary value problems for advection-reaction partial differential equations in multiple space dimensions. The derived numerical scheme is not subject to the Courant-Friedrichs-Lewy condition and generates accurate numerical solutions even if large time steps are used. Moreover, the scheme naturally incorporates boundary conditions into its formulation without any artificial outflow boundary conditions needed, and it conserves mass. An optimal-order error estimate is proved for the scheme. Numerical experiments are performed to verify the theoretical estimate.

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Microelectronics Process Engineering: A Non-Traditional Approach To Ms&E (Ingeniería De Procesos Microelectrónicos: Un Acercamiento No Tradicional A La Ciencia De Materiales E Ingeniería), E. Allen, Stacy H. Gleixner, G. Young, David W. Parent, Yasser Dessouky, L. Vanasupa Jan 2001

Microelectronics Process Engineering: A Non-Traditional Approach To Ms&E (Ingeniería De Procesos Microelectrónicos: Un Acercamiento No Tradicional A La Ciencia De Materiales E Ingeniería), E. Allen, Stacy H. Gleixner, G. Young, David W. Parent, Yasser Dessouky, L. Vanasupa

Faculty Publications

Materials Science and Engineering straddles the fence between engineering and science. In order to produce more work-ready undergraduates, we offer a new interdisciplinary program to educate materials engineers with a particular emphasis on microelectronics-related manufacturing. The bachelor's level curriculum in Microelectronics Process Engineering (J1ProE) is interdisciplinary, drawing from materials, chemical, electrical and industrial engineering programs and tied together with courses, internships and projects which integrate thin film processing with manufacturing control methods. Our graduates are prepared for entry level engineering jobs that require knowledge and experience in microelectronics-type fabrication and statistics applications in manufacturing engineering. They also go on to …

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Molecular Simulations Of Sound Wave Propagation In Simple Gases, Alejandro Garcia, N. Hadjiconstantinou Jan 2001

Molecular Simulations Of Sound Wave Propagation In Simple Gases, Alejandro Garcia, N. Hadjiconstantinou

Faculty Publications

Molecular simulations of sound waves propagating in a dilute hard sphere gas have been performed using the direct simulation Monte Carlo method. A wide range of frequencies is investigated, including very high frequencies for which the period is much shorter than the mean collision time. The simulation results are compared to experimental data and approximate solutions of the Boltzmann equation. It is shown that free molecular flow is important at distances smaller than one mean free path from the excitation point.

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An Alternative Use For Bagasse: Stabilizing Agent For Lead Waste, Michael A. Janusa Jan 2001

An Alternative Use For Bagasse: Stabilizing Agent For Lead Waste, Michael A. Janusa

Faculty Publications

Bagasse amounts to one- third of the cane ground and supplies fuel for the generation of steam in raw factories; however, most factories have an excess of bagasse during regular grinding season. Another method for the utilization of bagasse was investigated using bagasse as a stabilizing agent for heavy metal waste solidified /stabilized in cement. Lead nitrate was used as the model heavy me ta l waste with a 10 or 15 per cent lead by weight to cement loading. Samples were cured for 7, 14, and 28 days at 24°C. Samples containing bagasse typically resulted in TCLP extract lead …

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A Usage-Based Simulation Of Spanish S-Weakening, David Eddington Jan 2001

A Usage-Based Simulation Of Spanish S-Weakening, David Eddington

Faculty Publications

The pronunciation of Spanish /s/ as an aspirate [h] (or its deletion) is studied in a usagebased simulation that assumes that prior linguistic experiences are stored as memory traces, and that these stored experiences, instead of generalizations abstracted from them, are the source of the knowledge speakers have of their language. This exploratory simulation was carried out using the algorithm of Analogical Modeling of Language (Skousen 1989, 1992).

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Naturalized Epistemology And The Critique Of Evidence Theory, Dale A. Nance Jan 2001

Naturalized Epistemology And The Critique Of Evidence Theory, Dale A. Nance

Faculty Publications

In this article I give a mixed review Allen and Leiter’s naturalized epistemology theory of evidence. I applaud their focus on naturalized epistemology, but I question the claims that they argue follow from it. In some ways, my reaction is that they have not gone far enough in pressing its implications, and I attempt to suggest how further progress might be made along this path. On the whole, I conclude that the antipathy toward algrithms expressed by Allen and Leiter is misplaced.

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Beyond Campaign Finance: The First Amendment Implications Of Nixon V. Shrink Missouri Pac, Christina E. Wells Jan 2001

Beyond Campaign Finance: The First Amendment Implications Of Nixon V. Shrink Missouri Pac, Christina E. Wells

Faculty Publications

This essay, however, is less concerned with the campaign finance aspects of Shrink than with the decision's broader implications. In the course of its decision, the Shrink Court not only obfuscated the standard of scrutiny applicable to contribution regulations, it effectively ignored the government's lack of factual support for the law, instead accepting the state's assertions at face-value. Consequently, Shrink is far more than a simple application of Buckley. Rather, it reflects fundamental problems with the Court's standards of review in First Amendment cases generally. The more global nature of Shrink's problems suggest that, despite scholarly focus on the Buckley …

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A Preliminary Assessment Of Tidal Flooding Along The New Hampshire Coast: Past, Present And Future, Larry G. Ward, Jamie R. Adams Jan 2001

A Preliminary Assessment Of Tidal Flooding Along The New Hampshire Coast: Past, Present And Future, Larry G. Ward, Jamie R. Adams

Faculty Publications

This report presents the results of a preliminary study that examines several critical coastal issues for New Hampshire including sea level fluctuations (past, present and future), shoreline migrations, and tidal flooding. Included are: 1) an analysis of sea level changes over the Holocene and resulting shoreline migrations, 2) an assessment of low-lying areas with elevations below selected tidal flooding datums in coastal areas, and 3) an assessment of increases in low-lying areas that are potentially at risk to tidal flooding over the next century due to sea level rise.

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Evolutionary Implications Of Divergent Clines In An Avian (Manacus: Aves) Hybrid Zone, Robb T. Brumfield, Robert W. Jernigan, David B. Mcdonald, Michael J. Braun Jan 2001

Evolutionary Implications Of Divergent Clines In An Avian (Manacus: Aves) Hybrid Zone, Robb T. Brumfield, Robert W. Jernigan, David B. Mcdonald, Michael J. Braun

Faculty Publications

A previous study of the hybrid zone in western Panama between white-collared (Manacus candei) and golden-collared manakins (M. vitellinus) documented the unidirectional introgression of vitellinus male secondary sexual traits across the zone. Here, we examine the hybrid zone in greater genetic and morphological detail. Statistical comparisons of clines are performed using maximum-likelihood and nonparametric bootstrap methods. Our results demonstrate that an array of six molecular and two morphometric markers agree in cline position and width. Clines for male collar and belly color are similar in width to the first eight clines, but are shifted in position by at least five …

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The Asymptotic Equivalence Of The Fisher Information Matrices For Type I And Type Ii Censored Data From Location-Scale Families, Luis A. Escobar, William Q. Meeker Jan 2001

The Asymptotic Equivalence Of The Fisher Information Matrices For Type I And Type Ii Censored Data From Location-Scale Families, Luis A. Escobar, William Q. Meeker

Faculty Publications

Type I and Type II censored data arise frequently in controlled laboratory studies concerning time to a particular event (e.g., death of an animal or failure of a physical device). Log-location-scale distributions (e.g., Weibull, log-normal, and loglogistic) are commonly used to model the resulting data. Maximum likelihood (ML) is generally used to obtain parameter estimates when the data are censored. The Fisher information matrix can be used to obtain large-sample approximate variances and covariances of the ML estimates or to estimate these variances and covariances from data. The derivations of the Fisher information matrix proceed differently for Type I (time …

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Seiberg-Witten Invariants Of 4-Manifolds With Free Circle Actions, Scott Baldridge Jan 2001

Seiberg-Witten Invariants Of 4-Manifolds With Free Circle Actions, Scott Baldridge

Faculty Publications

The main results of this paper describes a formula for the Seiberg-Witten invariant of a 4-manifold which admits a nontrivial free circle action. We use this theorem to produce a nonsymplectic 4-manifold with a free circle action whose orbit space fibers over circle. We also describe a nontrivial 3-manifold which is not the orbit space of any symplectic 4-manifold with a free circle action. A corollary of the main theorem is a formula for the 3-dimensional Seiberg-Witten invariants of the total space of a circle bundle over a surface. © World Scientific Publishing Company.

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Causal Compactification And Hardy Spaces For Spaces Of Hermitian Type, Frank Betten, Gestur Ólafsson Jan 2001

Causal Compactification And Hardy Spaces For Spaces Of Hermitian Type, Frank Betten, Gestur Ólafsson

Faculty Publications

Let G/H be a compactly causal symmetric space with causal compactification Φ : G/H → Š1, where Š1 is the Bergman-Šilov boundary of a tube type domain G1/K1. The Hardy space H2(C) of G/H is the space of holomorphic functions on a domain Ξ(C°) ⊂ Gℂ/Hℂ with L2-boundary values on G/H. We extend Φ to imbed Ξ(C°) into G1/K1, such that Ξ(C°) = {z ∈ G1/K1 | ψm(z) ≠ 0}, with ψm explicitly known. We use this to construct an isometry I of the classical Hardy space Hcl on G1/K1 into H2(C) or into a Hardy space H̃2(C) defined on …

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Useful Alternative To The Multipole Expansion Of Potentials, H. S. Cohl, A. R.P. Rau, J. E. Tohline, D. A. Browne, J. E. Cazes, E. I. Barnes Jan 2001

Useful Alternative To The Multipole Expansion Of Potentials, H. S. Cohl, A. R.P. Rau, J. E. Tohline, D. A. Browne, J. E. Cazes, E. I. Barnes

Faculty Publications

Few-body problems involving Coulomb or gravitational interactions between pairs of particles, whether in classical or quantum physics, are generally handled through a standard multipole expansion of the two-body potentials. We develop an alternative based on an old, but hitherto forgotten, expression for the inverse distance between two points that builds on azimuthal symmetry. This alternative should have wide applicability throughout physics and astronomy, both for computation and for the insights it provides through its emphasis on different symmetries and structures than are familiar from the standard treatment. We compare and contrast the two methods, develop addition theorems for Legendre functions …

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The Bennequin Number Of N-Trivial Closed N-Braids Is Negative, Oliver T. Dasbach, Lin Xiao-Song Jan 2001

The Bennequin Number Of N-Trivial Closed N-Braids Is Negative, Oliver T. Dasbach, Lin Xiao-Song

Faculty Publications

A famous result of Bennequin states that for any braid representative of the unknot the Bennequin number is negative. We will extend this result to all n-trivial closed n-braids. This is a class of infinitely many knots closed under taking mirror images. Our proof relies on a non-standard parameterization of the HOMFLY polynomial. Another interesting corollary of this parameterization is that if all Vassiliev invariants up to degree c vanish on a knot of crossing number c, then this knot has trivial HOMFLY polynomial.

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Viscosity Solutions Of The Bellman Equation For Exit Time Optimal Control Problems With Non-Lipschitz Dynamics, Michael Malisoff Jan 2001

Viscosity Solutions Of The Bellman Equation For Exit Time Optimal Control Problems With Non-Lipschitz Dynamics, Michael Malisoff

Faculty Publications

We study the Bellman equation for undiscounted exit time optimal control problems with fully nonlinear Lagrangians and fully nonlinear dynamics using the dynamic programming approach. We allow problems whose non-Lipschitz dynamics admit more than one solution trajectory for some choices of open loop controls and initial positions. We prove a uniqueness theorem which characterizes the value functions of these problems as the unique viscosity solutions of the corresponding Bellman equations that satisfy appropriate boundary conditions. We deduce that the value function for Sussmann’s Reflected Brachystochrone Problem for an arbitrary singleton target is the unique viscosity solution of the corresponding Bellman …

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Quantum Measurement And Decoherence, G. W. Ford, J. T. Lewis, R. F. O’Connell Jan 2001

Quantum Measurement And Decoherence, G. W. Ford, J. T. Lewis, R. F. O’Connell

Faculty Publications

Distribution functions defined in accordance with the quantum theory of measurement are combined with results obtained from the quantum Langevin equation to discuss decoherence in quantum Brownian motion. Closed form expressions for wave packet spreading and the attenuation of coherence of a pair of wave packets are obtained. The results are exact within the context of linear passive dissipation. It is shown that, contrary to widely accepted current belief, decoherence can occur at high temperature in the absence of dissipation. Expressions for the decoherence time with and without dissipation are obtained that differ from those appearing in earlier discussions. © …

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Cure For Unstable Numerical Evolutions Of Single Black Holes: Adjusting The Standard Adm Equations In The Spherically Symmetric Case, Bernard Kelly, Pablo Laguna, Keith Lockitch, Jorge Pullin, Erik Schnetter, Deirdre Shoemaker, Manuel Tiglio Jan 2001

Cure For Unstable Numerical Evolutions Of Single Black Holes: Adjusting The Standard Adm Equations In The Spherically Symmetric Case, Bernard Kelly, Pablo Laguna, Keith Lockitch, Jorge Pullin, Erik Schnetter, Deirdre Shoemaker, Manuel Tiglio

Faculty Publications

Numerical codes based on a direct implementation of the standard Arnowitt-Deser-Misner (ADM) formulation of Einstein's equations have generally failed to provide long-term stable and convergent evolutions of black hole space-times when excision is used to remove the singularities. We show that, for the case of a single black hole in spherical symmetry, it is possible to circumvent these problems by adding terms involving the constraints to the evolution equations, thus adjusting the standard ADM system. We investigate the effect that the choice of the lapse and shift has on the stability properties of numerical simulations and thus on the form …

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Monodromy Of Fiber-Type Arrangements And Orbit Configuration Spaces, Daniel C. Cohen Jan 2001

Monodromy Of Fiber-Type Arrangements And Orbit Configuration Spaces, Daniel C. Cohen

Faculty Publications

We prove similar theorems concerning the structure of bundles involving complements of fiber-type hyperplane arrangements and orbit configuration spaces. These results facilitate analysis of the fundamental groups of these spaces, which may be viewed as generalizations of the Artin pure braid group. In particular, we resolve two disparate conjectures. We show that the Whitehead group of the fundamental group of the complement of a fiber-type arrangement is trivial, as conjectured by Aravinda, Farrell, and Rouchon [AFR]. For the orbit configuration space corresponding to the natural action of a finite cyclic group on the punctured plane, we determine the structure of …

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Semiclassical Application Of The Mo/Ller Operators In Reactive Scattering, Sophya V. Garashchuk, J. C. Light Jan 2001

Semiclassical Application Of The Mo/Ller Operators In Reactive Scattering, Sophya V. Garashchuk, J. C. Light

Faculty Publications

Mo/ller operators in the formulation of reaction probabilities in terms of wave packet correlation functions allow us to define the wave packets in the interaction region rather than in the asymptotic region of the potential surface. We combine Mo/ller operators with the semiclassical propagator of Herman and Kluk. This does not involve further approximations and can be used with any initial value representation (IVR) semiclassical propagator. Time propagation in asymptotic regions of the potential due to Mo/ller operators reduces the oscillations of the propagator integrand and improves convergence of the results with respect to the number of trajectories. The effectiveness …

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Self-Assembly Of A Bis-Urea Macrocycle Into A Columnar Nanotube, Linda S. Shimizu, Mark D. Smith, A. D. Hughes, Ken D. Shimizu Jan 2001

Self-Assembly Of A Bis-Urea Macrocycle Into A Columnar Nanotube, Linda S. Shimizu, Mark D. Smith, A. D. Hughes, Ken D. Shimizu

Faculty Publications

A bis-urea macrocycle 1 was synthesized and shown to form extended nanotubular columns byX-ray crystallography.

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Structure Determination Of Ba8Corh6O21, A New Member Of The 2h-Perovskite Related Oxides, Hans Conrad Zur Loye, M. D. Smith, K. E. Stitzer, A. El Abed, J. Darriet Jan 2001

Structure Determination Of Ba8Corh6O21, A New Member Of The 2h-Perovskite Related Oxides, Hans Conrad Zur Loye, M. D. Smith, K. E. Stitzer, A. El Abed, J. Darriet

Faculty Publications

Single crystals of Ba8CoRh6O21 were grown out of a potassium carbonate flux. The structure was solved by a general method using the superspace group approach. The superspace group employed was R3m(00γ)0s with a = 10.0431(1) Å, c1 = 2.5946(1) Å and c2 = 4.5405(1) Å, V = 226.60(1) Å3. Ba8CoRh6O21 represents the first example of an m = 5, n = 3 member of the A3n+3mA'nB3m+nO9m+6n family of 2H hexagonal perovskite related oxides and contains chains consisting of six …

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The Emerging Law Of Race And Student Assignment Plans, John Charles Boger, Elizabeth Jean Bower Jan 2001

The Emerging Law Of Race And Student Assignment Plans, John Charles Boger, Elizabeth Jean Bower

Faculty Publications

No abstract provided.

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The Craft Of Due Process, Kevin C. Mcmunigal Jan 2001

The Craft Of Due Process, Kevin C. Mcmunigal

Faculty Publications

Response to Professor Israel's presentation "On the Costs of Uniformity and the Prospects of Dualism in Constitutional Criminal Procedure."

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Design Of Peptides With, Α,Β-Dehydro-Residues: A Dipeptide With A Branched Β-Carbon Dehydro-Residue At The (I+1) Position, Methyl N-(Benzyloxycarbonyl)-Α,Β-Didehydrovalyl-L-Tryptophanate, Vijayaraghavan Rangachari, Pravindra Kumar, Sharmistha Dey, Tej P. Singh Jan 2001

Design Of Peptides With, Α,Β-Dehydro-Residues: A Dipeptide With A Branched Β-Carbon Dehydro-Residue At The (I+1) Position, Methyl N-(Benzyloxycarbonyl)-Α,Β-Didehydrovalyl-L-Tryptophanate, Vijayaraghavan Rangachari, Pravindra Kumar, Sharmistha Dey, Tej P. Singh

Faculty Publications

The structure of the title peptide, C25H27N3O5, has been determined and its conformation analysed. Values of the standard peptide torsion angles are φ(1) = -44.2 (3)°, ψ(1) = 135.9 (2)°, φ(2) = -141.6 (2)° and ψ(T/2) = 168.0 (2)°. The crystal structure is stabilized by an intermolecular hydrogen bond, with an N···O distance of 2.919 (3)Å, which is formed between screw-axis-related NH and CO groups of dehydrovaline residues.

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