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2009

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Full-Text Articles in Physical Sciences and Mathematics

Proposal For Evaluation Of The Feasibility Of Erecting Regional Wind Energy System Within The East Bay Of Rhode Island, Eapc Wind Energy Services, Llc Aug 2009

Proposal For Evaluation Of The Feasibility Of Erecting Regional Wind Energy System Within The East Bay Of Rhode Island, Eapc Wind Energy Services, Llc

East Bay Energy Consortium Documents

No abstract provided.


Asa Proposal: Evaluation Of The Feasibility Of Erecting Regional Wind Energy System Within The East Bay Of Ri, For East Bay Energy Consortium, Bristol, Rhode Island, Applied Science Associates, Inc Aug 2009

Asa Proposal: Evaluation Of The Feasibility Of Erecting Regional Wind Energy System Within The East Bay Of Ri, For East Bay Energy Consortium, Bristol, Rhode Island, Applied Science Associates, Inc

East Bay Energy Consortium Documents

No abstract provided.


Evaluation Of The Feasibility Of Erecting A Regional Wind Energy System Within The East Bay Of Rhode Island, Sustainable Global Energy, Llc Aug 2009

Evaluation Of The Feasibility Of Erecting A Regional Wind Energy System Within The East Bay Of Rhode Island, Sustainable Global Energy, Llc

East Bay Energy Consortium Documents

No abstract provided.


Response To Request For Evaluation Of The Feasibility Of Erecting A Regional Wind Energy System Within The East Bay Of R.I., Non-Price Proposal, Boreal Renewable Energy Development Aug 2009

Response To Request For Evaluation Of The Feasibility Of Erecting A Regional Wind Energy System Within The East Bay Of R.I., Non-Price Proposal, Boreal Renewable Energy Development

East Bay Energy Consortium Documents

No abstract provided.


Wind Power Feasibility Study: Proposal To East Bay Energy Consortium, Kema, Inc. Aug 2009

Wind Power Feasibility Study: Proposal To East Bay Energy Consortium, Kema, Inc.

East Bay Energy Consortium Documents

No abstract provided.


Targeted Maximum Likelihood Estimation: A Gentle Introduction, Susan Gruber, Mark J. Van Der Laan Aug 2009

Targeted Maximum Likelihood Estimation: A Gentle Introduction, Susan Gruber, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

This paper provides a concise introduction to targeted maximum likelihood estimation (TMLE) of causal effect parameters. The interested analyst should gain sufficient understanding of TMLE from this introductory tutorial to be able to apply the method in practice. A program written in R is provided. This program implements a basic version of TMLE that can be used to estimate the effect of a binary point treatment on a continuous or binary outcome.


Comparing Risk Scoring Systems Beyond The Roc Paradigm In Survival Analysis, Hajime Uno, Lu Tian, Tianxi Cai, Isaac S. Kohane, L. J. Wei Aug 2009

Comparing Risk Scoring Systems Beyond The Roc Paradigm In Survival Analysis, Hajime Uno, Lu Tian, Tianxi Cai, Isaac S. Kohane, L. J. Wei

Harvard University Biostatistics Working Paper Series

No abstract provided.


Education In The Environment: A Strategy For Continued Interagency Outdoor Education Programming: Quarterly Progress Report: Period Ending August 31, 2009, Environmental Education Strategy For Nevada Aug 2009

Education In The Environment: A Strategy For Continued Interagency Outdoor Education Programming: Quarterly Progress Report: Period Ending August 31, 2009, Environmental Education Strategy For Nevada

Reports (PLI Education)

Highlights of the university’s focused efforts during the past three months include the following:

  • Evaluation results from the NEEI Certification program will be presented at the North American Association for Environmental Education National Conference on October 9-10, 2009.
  • A grant was received from the Nevada Community Foundation for the printing of The Story of Gill graphic novel.
  • A total of 75 people participated in Families in Nature events at the Spring Mountains and Lake Mead National Recreation Areas.
  • A third Nevada Environmental Education & Interpretation Certification program was held August 12-18, 2009 for twelve participants.
  • A third Our Places Tell …


High-K Multi-Quasiparticle States And Rotational Bands In 255103Lr., H. B. Jeppesen, R. M. Clark, K. E. Gregorich, A. V. Afanasjev, M. N. Ali, J. M. Allmond, C. W. Beausang, M. Cromaz, M. A. Deleplanque, I. Dragojevic, J. Dvorak, P. A. Ellison, P. Fallon, M. A. Garcia, J. M. Gates, S. Gros, I. Y. Lee, A. O. Macchiavelli, S. L. Nelson, H. Nitsche, L. Stavsetra, F. S. Stephens, M. Wiedeking Aug 2009

High-K Multi-Quasiparticle States And Rotational Bands In 255103Lr., H. B. Jeppesen, R. M. Clark, K. E. Gregorich, A. V. Afanasjev, M. N. Ali, J. M. Allmond, C. W. Beausang, M. Cromaz, M. A. Deleplanque, I. Dragojevic, J. Dvorak, P. A. Ellison, P. Fallon, M. A. Garcia, J. M. Gates, S. Gros, I. Y. Lee, A. O. Macchiavelli, S. L. Nelson, H. Nitsche, L. Stavsetra, F. S. Stephens, M. Wiedeking

Physics Faculty Publications

Two isomeric states have been identified in 255Lr. The decay of the isomers populates rotational structures. Comparison with macroscopic-microscopic calculations suggests that the lowest observed sequence is built upon the [624]9/2+ Nilsson state. However, microscopic cranked relativistic Hartree-Bogoliubov (CRHB) calculations do not reproduce the moment of inertia within typical accuracy. This is a clear challenge to theories describing the heaviest elements.


Waves In Inhomogeneous Solids, Arkadi Berezovski, Mihhail Berezovski, Juri Engelbrecht Aug 2009

Waves In Inhomogeneous Solids, Arkadi Berezovski, Mihhail Berezovski, Juri Engelbrecht

Publications

The paper aims at presenting a numerical technique used in simulating the propagation of waves in inhomogeneous elastic solids. The basic governing equations are solved by means of a finite-volume scheme that is faithful, accurate, and conservative. Furthermore, this scheme is compatible with thermodynamics through the identification of the notions of numerical fluxes (a notion from numerics) and of excess quantities (a notion from irreversible thermodynamics). A selection of one-dimensional wave propagation problems is presented, the simulation of which exploits the designed numerical scheme. This selection of exemplary problems includes (i) waves in periodic media for weakly nonlinear waves with …


Wind Power Pre-Feasibility Study For The East Bay Of Rhode Island, Technical Proposal, Ea Engineering, Science, And Technology, Inc. Aug 2009

Wind Power Pre-Feasibility Study For The East Bay Of Rhode Island, Technical Proposal, Ea Engineering, Science, And Technology, Inc.

East Bay Energy Consortium Documents

No abstract provided.


Proposal For Evaluation Of The Feasibility Of Erecting Regional Wind Energy System Within The East Bay Of Rhode Island, Ess Group, Inc. Aug 2009

Proposal For Evaluation Of The Feasibility Of Erecting Regional Wind Energy System Within The East Bay Of Rhode Island, Ess Group, Inc.

East Bay Energy Consortium Documents

No abstract provided.


Operations Research Methods For Optimization In Radiation Oncology, M Ehrgott, Allen Holder Aug 2009

Operations Research Methods For Optimization In Radiation Oncology, M Ehrgott, Allen Holder

Mathematical Sciences Technical Reports (MSTR)

Operations Research has a successful tradition of applying mathematical analysis to a wide range of applications, with one of the burgeoning areas of growth being in medical physics. The original application was in the optimal design of the influence map for a radiotherapy treatment, a problem that has continued to receive attention. However, operations research has been applied to other clinical problems like patient scheduling, vault design, and image alignment. The overriding theme of this article is to present how techniques in operations research apply to clinical problems, which we accomplish in three parts. First, we present the perspective from …


Contact Process In A Wedge, J. Theodore Cox, Nevena Maric, Rinaldo Schinazi Aug 2009

Contact Process In A Wedge, J. Theodore Cox, Nevena Maric, Rinaldo Schinazi

Mathematics - All Scholarship

We prove that the supercritical one-dimensional contact process survives in certain wedge-like space-time regions, and that when it survives it couples with the unrestricted contact process started from its upper invariant measure. As an application we show that a type of weak coexistence is possible in the nearest-neighbor "grass-bushes-trees'' successional model introduced in Durrett and Swindle (1991).


Strain Energy And Lateral Friction Force Distributions Of Carbon Nanotubes Manipulated Into Shapes By Atomic Force Microscopy, Mark C. Strus, Roya R. Lahiji, Pablo Ares, Vincente Lopez, Arvind Raman, Ron R. Reifenberger Aug 2009

Strain Energy And Lateral Friction Force Distributions Of Carbon Nanotubes Manipulated Into Shapes By Atomic Force Microscopy, Mark C. Strus, Roya R. Lahiji, Pablo Ares, Vincente Lopez, Arvind Raman, Ron R. Reifenberger

Other Nanotechnology Publications

The interplay between local mechanical strain energy and lateral frictional forces determines the shape of carbon nanotubes on substrates. In turn, because of its nanometer-size diameter, the shape of a carbon nanotube strongly influences its local electronic, chemical, and mechanical properties. Few, if any, methods exist for resolving the strain energy and static frictional forces along the length of a deformed nanotube supported on a substrate. We present a method using nonlinear elastic rod theory in which we compute the flexural strain energy and static frictional forces along the length of single walled carbon nanotubes (SWCNTs) manipulated into various shapes …


Lifting Bailey Pairs To Wp-Bailey Pairs, James Mclaughlin, Andrew Sills, Peter Zimmer Aug 2009

Lifting Bailey Pairs To Wp-Bailey Pairs, James Mclaughlin, Andrew Sills, Peter Zimmer

Department of Mathematical Sciences Faculty Publications

A pair of sequences (αn(a,k,q),βn(a,k,q)) such that α0(a,k,q)=1 and βn(a,k,q)=∑nj=0 (k/a;q)n−j (k;q)n+j / (q;q)n−j (aq;q)n+j αj (a,k,q) is termed a WP-Bailey Pair. Upon setting k=0 in such a pair we obtain a Bailey pair.

In the present paper we consider the problem of “lifting” a Bailey pair to a WP-Bailey pair, and use some …


Magma Extraction From The Mantle Wedge At Convergent Margins Through Dikes: A Parametric Sensitivity Analysis, Scott E. Johnson, Z.-H. Jin Aug 2009

Magma Extraction From The Mantle Wedge At Convergent Margins Through Dikes: A Parametric Sensitivity Analysis, Scott E. Johnson, Z.-H. Jin

Earth Science Faculty Scholarship

We address under what conditions a magma generated by partial melting at 100 km depth in the mantle wedge above a subduction zone can reach the crust in dikes before stalling. We also address under what conditions primitive basaltic magma (Mg # >60) can be delivered from this depth to the crust. We employ linear elastic fracture mechanics with magma solidification theory and perform a parametric sensitivity analysis. All dikes are initiated at a depth of 100 km in the thermal core of the wedge, and the Moho is fixed at 35 km depth. We consider a range of melt …


A Simple Model Of Cortical Dynamics Explains Variability And State Dependence Of Sensory Responses In Urethane-Anesthetized Auditory Cortex, Carina Curto, Shuzo Sakata, Stephan Marguet, Vladimir Itskov, Kenneth D. Harris Aug 2009

A Simple Model Of Cortical Dynamics Explains Variability And State Dependence Of Sensory Responses In Urethane-Anesthetized Auditory Cortex, Carina Curto, Shuzo Sakata, Stephan Marguet, Vladimir Itskov, Kenneth D. Harris

Department of Mathematics: Faculty Publications

The responses of neocortical cells to sensory stimuli are variable and state dependent. It has been hypothesized that intrinsic cortical dynamics play an important role in trial-to-trial variability; the precise nature of this dependence, however, is poorly understood. We show here that in auditory cortex of urethane-anesthetized rats, population responses to click stimuli can be quantitatively predicted on a trial-by-trial basis by a simple dynamical system model estimated from spontaneous activity immediately preceding stimulus presentation. Changes in cortical state correspond consistently to changes in model dynamics, reflecting a nonlinear, self-exciting system in synchronized states and an approximately linear system in …


Destruction, Amorphization And Reactivity Of Nano-Bn Under Ball Milling, A. N. Streletskii, D. G. Permenov, B. B. Bokhonov, I. V. Kolbanev, A. V. Leonov, I. V. Berestetskaya, Kiril A. Streletzky Aug 2009

Destruction, Amorphization And Reactivity Of Nano-Bn Under Ball Milling, A. N. Streletskii, D. G. Permenov, B. B. Bokhonov, I. V. Kolbanev, A. V. Leonov, I. V. Berestetskaya, Kiril A. Streletzky

Physics Faculty Publications

The processes of mechanical activation of a hexagonal boron nitride (h-BN) and its reactivity upon interaction with hydrogen and water were investigated using X-ray, TEM, Microdiffraction, Dynamic Light Scattering, FTIR-spectroscopy, adsorption (BET). Initial h-BN samples were monocrystalline plates 70–80 nm thick. Mechanical treatment of h-BN is accompanied by plate splitting and formation of crystallographically oriented “rods.” The rod thickness gradually diminishes to less than 5 nm. Specific surface area of the rods (400 m2/g), is found to be equal to the outer geometrical surface of rods. As nanocrystallites form “c” parameter of h-BN increases. When nanocrystallites are less than several …


Transition To Mixing And Oscillations In A Stokesian Viscoelastic Flow, Becca Thomases, Michael Shelley Aug 2009

Transition To Mixing And Oscillations In A Stokesian Viscoelastic Flow, Becca Thomases, Michael Shelley

Mathematics Sciences: Faculty Publications

In seeking to understand experiments on low-Reynolds-number mixing and flow transitions in viscoelastic fluids, we simulate the dynamics of the Oldroyd-B model, with a simple background force driving the flow. We find that at small Weissenberg number, flows are "slaved" to the extensional geometry imposed by forcing. For large Weissenberg number, such solutions become unstable and transit to a structurally dissimilar state dominated by a single large vortex. This new state can show persistent oscillatory behavior with the production and destruction of smaller-scale vortices that drive mixing.


Search For Gravitational Waves From Low Mass Compact Binary Coalescence In 186 Days Of Ligo's Fifth Science Run, B. P. Abbott, R. Abbott, R. Adhikari, P. Ajith, B. Allen, G. Allen, R. S. Amin, S. B. Anderson, W. G. Anderson, M. A. Arain, Rodica Martin Aug 2009

Search For Gravitational Waves From Low Mass Compact Binary Coalescence In 186 Days Of Ligo's Fifth Science Run, B. P. Abbott, R. Abbott, R. Adhikari, P. Ajith, B. Allen, G. Allen, R. S. Amin, S. B. Anderson, W. G. Anderson, M. A. Arain, Rodica Martin

Department of Physics and Astronomy Faculty Scholarship and Creative Works

We report on a search for gravitational waves from coalescing compact binaries, of total mass between 2 and 35M, using LIGO observations between November 14, 2006 and May 18, 2007. No gravitational-wave signals were detected. We report upper limits on the rate of compact binary coalescence as a function of total mass. The LIGO cumulative 90%-confidence rate upper limits of the binary coalescence of neutron stars, black holes and black hole-neutron star systems are 1.4×10-2, 7.3×10-4 and 3.6×10-3yr-1L10-1, respectively, where L10 is 1010 times the blue solar luminosity.


Doubt And The Values Of An Ignorance-Based World View For Restoration: Coastal Louisiana Wetlands, R. Eugene Turner Aug 2009

Doubt And The Values Of An Ignorance-Based World View For Restoration: Coastal Louisiana Wetlands, R. Eugene Turner

Faculty Publications

Embracing doubt, a signature strength of science, is an essential core component of an ignorance-based-world view (IBWV) that assumes the areas of certainty are small relative to the large field of ignorance. The contrasting knowledge-based world view (KBWV) assumes that small and mostly insignificant knowledge gaps exist. When the KBWV is combined with a sense of urgency to “do something,” then the intellectual landscape is flattened, the introduction of new ideas is impeded, monitoring and adaptive management is marginalized, risky behaviors continue, and social learning is restricted. The history of three coastal Louisiana land-uses (agricultural impoundment, marsh management, and dredging) …


Detection Of Extended Vhe Gamma Ray Emission From G106.3+2.7 With Veritas, P. T. Reynolds, Et Al Aug 2009

Detection Of Extended Vhe Gamma Ray Emission From G106.3+2.7 With Veritas, P. T. Reynolds, Et Al

Physical Sciences Publications

We report the detection of very-high-energy (VHE) gamma-ray emission from supernova remnant (SNR) G106.3+2.7. Observations performed in 2008 with the VERITAS atmospheric Cherenkov gamma-ray telescope resolve extended emission overlapping the elongated radio SNR. The 7.3σ (pre-trials) detection has a full angular extent of roughly 06 by 04. Most notably, the centroid of the VHE emission is centered near the peak of the coincident 12CO (J = 1-0) emission, 04 away from the pulsar PSR J2229+6114, situated at the northern end of the SNR. Evidently the current-epoch particles from the pulsar wind nebula are not participating in the gamma-ray production. …


Search For Gravitational Waves From Low Mass Compact Binary Coalescence In 186 Days Of Ligo's Fifth Science Run, B. P. Abbott, R. Abbott, R. Adhikari, P. Ajith, B. Allen, G. Allen, R. S. Amin, S. B. Anderson, W. G. Anderson, M. A. Arain, M. Araya, H. Armandula, P. Armor, Y. Aso, S. Aston, P. Aufmuth, C. Aulbert, S. Babak, P. Baker, S. Ballmer, C. Barker, D. Barker, B. Barr, P. Barriga, L. Barsotti, M. A. Barton, I. Bartos, R. Bassiri, M. Bastarrika, B. Behnke, M. Benacquista, Tiffany Z. Summerscales Aug 2009

Search For Gravitational Waves From Low Mass Compact Binary Coalescence In 186 Days Of Ligo's Fifth Science Run, B. P. Abbott, R. Abbott, R. Adhikari, P. Ajith, B. Allen, G. Allen, R. S. Amin, S. B. Anderson, W. G. Anderson, M. A. Arain, M. Araya, H. Armandula, P. Armor, Y. Aso, S. Aston, P. Aufmuth, C. Aulbert, S. Babak, P. Baker, S. Ballmer, C. Barker, D. Barker, B. Barr, P. Barriga, L. Barsotti, M. A. Barton, I. Bartos, R. Bassiri, M. Bastarrika, B. Behnke, M. Benacquista, Tiffany Z. Summerscales

Faculty Publications

We report on a search for gravitational waves from coalescing compact binaries, of total mass between 2 and 35M, using LIGO observations between November 14, 2006 and May 18, 2007. No gravitational-wave signals were detected. We report upper limits on the rate of compact binary coalescence as a function of total mass. The LIGO cumulative 90%-confidence rate upper limits of the binary coalescence of neutron stars, black holes and black hole-neutron star systems are 1.4×10-2, 7.3×10-4 and 3.6×10-3yr-1L10-1, respectively, where L10 is 1010 times the blue solar luminosity. © 2009 The American Physical Society.


Combinational Mixtures Of Multiparameter Distributions, Valeria Edefonti, Giovanni Parmigiani Aug 2009

Combinational Mixtures Of Multiparameter Distributions, Valeria Edefonti, Giovanni Parmigiani

Johns Hopkins University, Dept. of Biostatistics Working Papers

We introduce combinatorial mixtures - a flexible class of models for inference on mixture distributions whose component have multidimensional parameters. The key idea is to allow each element of the component-specific parameter vectors to be shared by a subset of other components. This approach allows for mixtures that range from very flexible to very parsimonious, and unifies inference on component-specific parameters with inference on the number of components. We develop Bayesian inference and computation approaches for this class of distributions, and illustrate them in an application. This work was originally motivated by the analysis of cancer subtypes: in terms of …


Online Piece-Wise Linear Approximation Of Numerical Streams With Precision Guarantees, Hazem Elmeleegy, Ahmed Elmagarmid, Emmanuel Cecchet, Walid G. Aref, Willy Zwaenepoel Aug 2009

Online Piece-Wise Linear Approximation Of Numerical Streams With Precision Guarantees, Hazem Elmeleegy, Ahmed Elmagarmid, Emmanuel Cecchet, Walid G. Aref, Willy Zwaenepoel

Cyber Center Publications

Continuous “always-on” monitoring is beneficial for a number of applications, but potentially imposes a high load in terms of communication, storage and power consumption when a large number of variables need to be monitored. We introduce two new filtering techniques, swing filters and slide filters, that represent within a prescribed precision a time-varying numerical signal by a piecewise linear function, consisting of connected line segments for swing filters and (mostly) disconnected line segments for slide filters. We demonstrate the effectiveness of swing and slide filters in terms of their compression power by applying them to a reallife data set plus …


Quality Control Of Soil Water Data In Applied Climate, Jinshing You, Kenneth Hubbard, Rezaul Mamood, Venkataramana Sridhar, Dennis Todey Aug 2009

Quality Control Of Soil Water Data In Applied Climate, Jinshing You, Kenneth Hubbard, Rezaul Mamood, Venkataramana Sridhar, Dennis Todey

School of Natural Resources: Faculty Publications

Abstract: Soil moisture is a key state variable from both climate and hydrologic cycle assessment perspectives. Recently, automated measurements of soil moisture with sensors deployed at sites in a real-time monitoring network have provided valuable new data to monitor the soil water resource. However, to assure the quality of the data, quality control QC tools are needed. Earlier studies left little literature on the QC of soil water data as measurements were generally not part of a network that routinely collected measurements. This paper presents a systematic QC analysis and methodology to evaluate the performance of candidate QC techniques using …


Florida Boating Access Facilities Inventory And Economic Study, Including A Pilot Study For Lee County: A Report To The Florida Fish And Wildlife Conservation Commission, Urban Harbors Institute, University Of Massachusetts Boston, Bordner Research, Inc., Recreational Marine Research Center Of Michigan State University, Center For Urban And Environmental Solutions Of Florida Atlantic University, Environmental Economics, Inc., Planning And Zoning Center Of Michigan State University, Resource Economics Research, Llc Aug 2009

Florida Boating Access Facilities Inventory And Economic Study, Including A Pilot Study For Lee County: A Report To The Florida Fish And Wildlife Conservation Commission, Urban Harbors Institute, University Of Massachusetts Boston, Bordner Research, Inc., Recreational Marine Research Center Of Michigan State University, Center For Urban And Environmental Solutions Of Florida Atlantic University, Environmental Economics, Inc., Planning And Zoning Center Of Michigan State University, Resource Economics Research, Llc

Urban Harbors Institute Publications

This report describes the work program and results of the "Statewide Boating Access Facilities Inventory and Economic Study Including a Pilot Study for Lee County, Florida" commissioned by the Florida Fish and Wildlife Conservation Commission (FWC) in 2005. The study was funded in part by a grant to the FWC from the U.S. Fish and Wildlife Service and by Lee County. The scope and objectives of the study are summarized in the introduction, and the subsequent sections report on the various components of the study.

For many years, Florida has been among the fastest growing states in the nation, which …


Proceedings Of The Scheme And Functional Programming Workshop, John Clements (Editor) Aug 2009

Proceedings Of The Scheme And Functional Programming Workshop, John Clements (Editor)

Computer Science and Software Engineering

This volume contains the papers of the tenth annual Workshop on Scheme and Functional Programming, held August 22nd at Northeastern University in close proximity to the Symposium in honor of Mitchell Wand.


Pah Emission From Ultraluminous Infrared Galaxies, V. Desai, L. Armus, H. W. W. Spoon, Vassilis Charmandaris, J. Bernard-Salas, B. R. Brandl, D. Farrah, B.T. Soifer, H. I. Teplitz, P. M. Ogle, D. Devost, Sarah J.U. Higdon, J. A. Marshall, J. R. Houck Aug 2009

Pah Emission From Ultraluminous Infrared Galaxies, V. Desai, L. Armus, H. W. W. Spoon, Vassilis Charmandaris, J. Bernard-Salas, B. R. Brandl, D. Farrah, B.T. Soifer, H. I. Teplitz, P. M. Ogle, D. Devost, Sarah J.U. Higdon, J. A. Marshall, J. R. Houck

Department of Physics and Astronomy Faculty Publications

We explore the relationships between the Polycyclic Aromatic Hydrocarbon (PAH) feature strengths, mid-infrared continuum luminosities, far-infrared spectral slopes, optical spectroscopic classifications, and silicate optical depths within a sample of 107 ULIRGs observed with the Infrared Spectrograph on the Spitzer Space Telescope. The detected 6.2 µm PAH equivalent widths (EQWs) in the sample span more than two orders of magnitude (∼0.006–0.8 µm), and ULIRGs with HII-like optical spectra or steep far-infrared spectral slopes (S25/S60 < 0.2) typically have 6.2 µm PAH EQWs that are half that of lower-luminosity starbursts. A significant fraction (∼40–60%) of HII-like, LINER-like, and cold ULIRGs have very weak PAH EQWs. Many of these ULIRGs also have large (τ9.7 > 2.3) silicate optical depths. The far-infrared spectral slope is strongly correlated with PAH EQW, but not with silicate optical depth. In addition, the PAH EQW decreases with …