Digital Commons Network^™

Polarization Effects In Photoluminescence Of C- And M-Plane Gan/Algan Multiple Quantum Wells, E. Kuokstis, C. Q. Chen, M. E. Gaevski, W. H. Sun, J. W. Yang, Grigory Simin, M. Asif Khan, H. P. Maruska, D. W. Hill, M. C. Chou, J. J. Gallagher, B. Chai

Faculty Publications

Polarizationeffects have been studied in GaN/AlGaN multiple quantum wells(MQWs) with different c-axis orientation by means of excitation-dependent photoluminescence(PL) analysis. Quantum structures were grown on [0001]-oriented sapphire substrates (C plane) and single-crystalline [11̄00]-oriented freestanding GaN (M plane) using the metalorganic chemical vapor deposition technique. Strong PL spectrum line blueshifts (up to 140 meV) which are correlated with the excitation intensity have been obtained for C-plane MQWs, whereas no shift has been observed for M-plane MQWs.Theoretical calculations and comparison with the PL data confirm that the built-in electric field for C-plane structures is much stronger than the field present for M-plane MQWs. …

Statistical Cataloging Of Archival Data For Luminosity Class Iv-V Stars - Ii. The Epoch 2001 [Fe/H] Catalog, B. J. Taylor

Faculty Publications

This paper describes the derivation of an updated statistical catalog of metallicities. The stars for which those metallicities apply are of spectral types F, G, and K, and are on or near the main sequence. The input data for the catalog are values of [Fe/H] published before 2002 February and derived from lines of weak and moderate strength. The analyses used to derive the data have been based on one-dimensional LTE model atmospheres. Initial adjustments which are applied to the data include corrections to a uniform temperature scale which is given in a companion paper (see Taylor 2003). After correction, …

Statistical Cataloging Of Archival Data For Luminosity Class Iv-V Stars, B. J. Taylor

Faculty Publications

This paper is one of a pair in which temperatures and metallicity catalogs for class IV-V stars are considered. The temperature catalog described here is derived from a calibration based on stellar angular diameters. If published calibrations of this kind are compared by using color-index transformations, temperature-dependent differences among the calibrations are commonly found. However, such differences are minimized if attention is restricted to calibrations based on Johnson V-K. A calibration of this sort from Di Benedetto (1998) is therefore tested and adopted. That calibration is then applied to spectroscopic and photometric data, with the latter predominating. Cousins R-I photometry …

Annotated Bibliography Of Research In The Teaching Of English, Deborah Brown, Catherine Beavis, Judith Kalman, Macrina Gómez, Gert Rijlaarsdam, Anne D'Antonio Stinson, Melissa E. Whiting

Faculty Publications

Twice a year, in the May and November issues, RTE publishes a selected bibliography of recent research in the teaching of English. Most of the studies appeared during the six-month period preceding the compilation of the bibliography (January through June 2002 for the present bibliography), but some studies that appeared earlier are occasionally included. The listing is selective; we make no attempt to include all research and research-related articles that appeared in the period under review. Comments on the bibliography and suggestions about items for inclusion may be directed to the bibliography editors. We encourage you to send your suggestions …

The Design And Evaluation Of Interactivities In A Digital Library, Muniram Budhu, Anita Coleman

Faculty Publications

The US National Science Foundation has established a program to create a National Science, Mathematics, Engineering and Technology Education Digital Library (NSDL). One of the subsidiary NSDL libraries under development is the National Civil Engineering Educational Resources Library (NCERL). The first phase of NCERL is the creation and collection of digital resources in three areas of civil engineering—geotechnical (soil), rock, and water engineering (GROW). The concept of interactivities guides the design, development, and evaluation efforts of the GROW digital collection. This article describes the salient features of GROW, defines and discusses interactivities as an emerging, integral part of teaching and …

Activity Patterns And Correlates Among Youth: Differences By Weight Status, Wendell C. Taylor, James F. Sallis, Marsha Dowda, Patty S. Freedson, Karen Eason, Russell R. Pate

Faculty Publications

The purposes of the study were to assess differences in physical activity levels and correlates of physical activity among overweight (‡ 85th percentile of body mass index for their sex and age) and non-overweight (< 85th percentile) youth. The sample included 509 seventh through twelfth graders. Activity was measured by a 7-day, 46-item activity checklist. Overweight girls were more sedentary than non-overweight girls (p<.03), and non-overweight girls engaged in more vigorous physical activity than overweight girls (p<.03). For boys, there were no significant differences in activity. The regression analyses for vigorous activity yielded the largest total R²'s (R²=.049 for overweight and R²=.27 for non-overweight.) The significant factor for overweight youth was greater athletic coordination (p<.01). For non-overweight youth, the significant factors were greater family support (p<.05), greater peer support (p<.001), fewer barriers (p<.03), and greater athletic coordination (p<.01). Correlates of physical activity vary by weight status of young people.

Associations Between Cardiorespiratory Fitness And C-Reactive Protein In Men, Timothy S. Church, Carolyn E. Barlow, Conrad P. Earnest, James B. Kampert, Elisa L. Priest, Steven N. Blair

Faculty Publications

Objective - This study examined the association between cardiorespiratory fitness and C-reactive protein (CRP), with adjustment for weight and within weight categories.

Methods and Results - We calculated median and adjusted geometric mean CRP levels, percentages of individuals with an elevated CRP (≥2.00 mg/L), and odds ratios of elevated CRP across 5 levels of cardiorespiratory fitness for 722 men. CRP values were adjusted for age, body mass index, vitamin use, statin medication use, aspirin use, the presence of inflammatory disease, cardiovascular disease, and diabetes, and smoking habit. We found an inverse association of CRP across fitness levels (P for …

Review Of The New Americans: How The Melting Pot Can Work Again, By Michael Barone, Fred Foldvary

Faculty Publications

A review of The New Americans: How the Melting Pot Can Work Again, by Michael Barone. Regnery Publishing • 2001 • 338 pages • $27.95 

Mapping The Mesoscale Interface Structure In Polycrystalline Materials, Brent L. Adams, C. L. Bauer, D. Casasent, A. Morawiec, S. Ozdemir, A. Talukder, Chialin T. Wu

Faculty Publications

This work was supported primarily by the MRSEC Program of the National Science Foundation under Award Numbers DMR-9632556 and DMR-0079996. A new experimental approach to the quantitative characterization of polycrystalline microstructure by scanning electron microscopy is described. Combining automated electron backscattering diffraction with conventional scanning contrast imaging and with calibrated serial sectioning, the new method (Mesoscale Interface Mapping System, MIMS) recovers precision estimates of the 3-dimensional idealized aggregate function G(x). This function embodies a description of lattice phase and orientation (limiting resolution ~ 1 degree) at each point x (limiting spatial resolution ~ 100 nanometers), and therefore contains a complete …

Modeling The Multicast Address Allocation Problem, Daniel Zappala, Chris Gauthierdickey, Virginia Lo

Faculty Publications

To support IP multicast, domains must assign a unique multicast address to each application from a limited, globally-shared address space. We examine the performance of several classes of address allocation algorithms withln the context of the MASC architecture. This study is the first of its kind to model the generalized multicast address allocation problem and consider non-contiguous allocation algorithms. We find that prefix-based allocation outperforms our non-contiguous algorithm, despite the apparent advantages of non-contiguous allocation. We also verify the benefits of using worst-fit for new allocations.

A Theoretical Framework For The Multicast Address Allocation Problem, Daniel Zappala, Chris Gauthierdickey, Virginia Lo, Timothy Singer

Faculty Publications

The multicast address allocation problem requires Internet domains to allocate unique addresses to multicast applications from a globally-shared space. We develop a theoretical framework for multicast allocation algorithms that is influenced by subcube allocation in hypercube computer systems. Based on this framework we derive complexity results for the address allocation problem and describe several new allocation algorithms that use a hypercube model for address representation.

Horizon Occlusion Culling For Real-Time Rendering Of Hierarchical Terrains, Parris K. Egbert, Brandon Lloyd

Faculty Publications

We present a technique to perform occlusion culling for hierarchical terrains at run-time. The algorithm is simple to implement and requires minimal pre-processing and additional storage, yet leads to 2-4 times improvement in framerate for views with high degrees of occlusion. Our method is based on the well-known occlusion horizon algorithm. We show how to adapt the algorithm for use with hierarchical terrains. The occlusion horizon is constructed as the terrain is traversed in an approximate front to back ordering. Regions of the terrain are compared to the horizon to determine when they are completely occluded from the viewpoint. Culling …

Gan Homoepitaxy On Freestanding (11̄00) Oriented Gan Substrates, C. Q. Chen, M. E. Gaevski, W. H. Sun, E. Kuokstis, J. P. Zhang, R. S. Q. Fareed, H. M. Wang, J. W. Yang, Grigory Simin, M. A. Khan, Herbert-Paul Maruska, David W. Hill, Mitch M. C. Chou, Bruce Chai

Faculty Publications

We report homoepitaxialGaNgrowth on freestanding (11̄00) oriented (M-plane GaN) substrates using low-pressure metalorganic chemical vapor deposition.Scanning electron microscopy,atomic-force microscopy, and photoluminescence were used to study the influence of growth conditions such as the V/III molar ratio and temperature on the surface morphology and optical properties of the epilayers. Optimized growth conditions led to high quality (11̄00) oriented GaN epilayers with a smooth surface morphology and strong band-edge emission. These layers also exhibited strong room temperature stimulated emission under high intensity pulsed optical pumping. Since for III-N materials the (11̄00) crystal orientation is free from piezoelectric or spontaneous polarization electric fields, …

Low-Temperature Operation Of Alfan Single-Quantum-Well Light-Emitting Diodes With Deep Ultraviolet Emission At 285 Nm, A. Chitnis, R. Pachipulusu, V. Mandavilli, M. Shatalov, E. Kuokstis, J. P. Zhang, V. Adivarahan, S. Wu, Grigory Simin, M. Asif Khan

Faculty Publications

We present a study of the electrical and optical characteristics of 285 nm emission deep ultraviolet light-emitting diodes(LED) at temperatures from 10 to 300 K. At low bias, our data show the tunneling carrier transport to be the dominant conduction mechanism. The room-temperature performance is shown to be limited mostly by poor electron confinement in the active region and a pronounced deep level assisted recombination but not by the hole injection into the active region. At temperatures below 100 K, the electroluminescence peak intensity increases by more than one order of magnitude indicating that with a proper device design and …

Rf Rendez-Blue: Reducing Power And Inquiry Costs In Bluetooth-Enabled Mobile Systems, Eric S. Hall, Charles D. Knutson, David K. Vawdrey

Faculty Publications

In resource-limited mobile computing devices, Bluetooth wireless technology imposes a weighty burden due to inefficient power utilization and a sluggish device discovery process. Buttressing Bluetooth with Radio Frequency Identification (RFID) technology by performing an operation we call “Rendez-Blue” alleviates these limitations. In the Rendez-Blue process, an RFID signal is used as a cue to “wake-up” a sleeping Bluetooth radio. This ensures that the Bluetooth radio is active only when needed, significantly reducing power consumption. In addition, RFID is used to communicate Bluetooth device information, allowing the user to bypass the traditional 10.24-second discovery process.

An Evaluation Of Factors Related To The Disproportionate Representation Of Children Of Color In Santa Clara County’S Child Welfare System: Child And Family Characteristics And Pathways Through The System Phase 2, Alice Hines, Peter Lee, Laurie Drabble, Lonnie Snowden, Kathy Lemon Osterling

Faculty Publications

While child abuse and neglect appears to affect children of all racial and ethnic origins (US Department of Health and Human Services, 1998; Sedlack & Broadhurst, 1996), an analysis of national, California and Santa Clara County data on the ethnicities of children in out of home placement reveals that, compared to their presence in the general population, there is a disproportionate involvement of children of color in the public child welfare system (CWS). In Santa Clara County, in particular, when compared to the general population, African American, Hispanic/Latino and Native American children are overrepresented in the CWS, while Asian American/Pacific …

Experiments With Grow, Anita Coleman

Faculty Publications

No abstract provided.

Hate Speech In The Constitutional Law Of The United States, William B. Fisch

Faculty Publications

Our general reporter, Professor Pizzorusso, has given us “incitement to hatred” - primarily against a group of persons defined in terms of race, ethnicity, national origin, gender, religion, sexual orientation, and the like--as the working definition of “hate speech”, and asks to what extent such speech is constitutionally protected in the reporting countries. The United States of America are known at least in recent times for providing exceptionally broad protection for otherwise objectionable speech and expression, and hate speech is understood to be one of the areas in which they have positioned themselves further out on the speech-protective end of …

Between Law And Grace: Ritual And Ritual Studies In Recent Evangelical Thought, Gerald Klingbeil

Faculty Publications

No abstract provided.

Drawing The Line Between Taxes And Takings: The Continuous Burdens Principle, And Its Broader Application, Eric Kades

Faculty Publications

No abstract provided.

The End Of The Hudson Valley's Peculiar Institution: The Anti-Rent Movement's Politics, Social Relations, & Economics, Eric Kades

Faculty Publications

No abstract provided.

Isolation And Characterization Of Atriplex Hortensis And Sweet Chenopodium Quinoa Starches, K. H. Wright, K. C. Huber, Daniel J. Fairbanks, C. S. Huber

Faculty Publications

Starches from garden orach (Atriplex hortensis) and sweet quinoa (Chenopodium quinoa Willd. "Surumi") seeds were isolated, examined for compositional characteristics, and compared with bitter quinoa (Cheno-podium quinoa Willd.) starch. Garden orach and sweet quinoa seeds were similar in fat and ash contents, while garden orach seeds contained 10% more protein. Starches were isolated from seeds following a 12-hr soak in dilute alkaline solution using a series of grinding, screening, centrifugation, and washing steps. Isolated starches viewed by scanning electron microscopy yielded angular, polygonal granules 2 m in diameter. Starches displayed typical A-type crystalline packing arrangements as determined by X-ray powder …

Compact Focusing Von Hamos Spectrometer For Quantitative X-Ray Spectroscopy, Larry V. Knight, A. P. Shevelko, Yu S. Kasyanov, O. F. Yakushev

Faculty Publications

A compact focusing crystal spectrometer based on the von Hamos scheme is described. Cylindrically curved mica and graphite crystals with a radius of curvature of R = 20 mm are used in the spectrometer. A front illuminated charge-coupled device (CCD) linear array detector makes this spectrometer useful for real-time spectroscopy of laser-produced plasma x-ray sources within the wavelength range of lambda= 1.8-10 Angstroms. Calibration of crystals and the CCD linear array makes it possible to measure absolute photon fluxes. X-ray spectra in an absolute intensity scale were obtained from Mg, Ti, and Fe laser-produced plasmas, with a spectral resolution lambda/delta …

Bluetooth: An Emerging Technology For Wireless Personal Area Networks, Eric S. Hall, Charles D. Knutson, David K. Vawdrey

Faculty Publications

Look under your desk or behind your computer. See that rat’s nest of wires and cables? Almost every cable or wire that tethers us to our devices (or our devices to one another) is unnecessary. Bluetooth wireless technology promises to reduce the cabling chaos that afflicts us all. Bluetooth is a recently developed technology that uses radio frequency (RF) transceivers to provide point-to-multipoint wireless connectivity within a personal space. Bluetooth was designed for both voice and data communication at low per-unit costs while consuming little power. To achieve the cost and power goals, Bluetooth limits connectivity to a sphere of …

Performance Evaluation Of Path Searching Heuristics For Multicast Qos Routing, Daniel Zappala, Dayi Zhou

Faculty Publications

Quality of Service routing for multicast enables a group member to find and install a branch of the multicast tree that can meet its QoS constraints. The most promising protocols in this area use receiver-oriented path searching heuristics to find feasible routes. In this paper, we examine the performance of the path searching heuristics used by these protocols, to determine which techniques are the most effective. We find that several low-overhead path searching heuristics are effective, and that generic path searching can work as well as targeted, QoS-specific searching.

Near-Band-Edge Photoluminescence Of Wurtzite-Type Aln, E. Kuokstis, J. Zhang, Q. Fareed, J. W. Yang, Grigory Simin, M. Asif Khan, R. Gaska, M. Shur, C. Rojo, L. Schowalter

Faculty Publications

Temperature-dependentphotoluminescence(PL)measurements were performed for A-plane and C-plane bulk AlN single crystals and epitaxial layers on sapphire. A strong near-band-edge (NBE) emission and deep-level luminescence were observed. At low excitations, the emission spectra are dominated by free and bound excitonic transitions and their LO-phonon replicas. At high excitations, the broadening and redshift of the NBE band is attributed to dense electron–hole plasma formation. The PL spectra differences of bulk single crystals and epilayers is explained by the electron–hole plasma expansion peculiarities.

I Am/Was The Walrus, Daniel Beller-Mckenna

Faculty Publications

For most of his adult life, John Lennon fought to define himself against his public identity as "Beatle-:John." That image, crafted by the Beatles' manager Brian Epstein and the pop music industry became a burden to all four of the Beatles during the group's seven years of international star-dom. In place of the rough leather-clad rock and roll band that played rambling one hour sets in the Hamburg Kaiserkeller and the Liverpool Cavern Club during 1960-61, Epstein forged a more commercially viable group of four well (and uniformly) dressed young men whose stage act was reduced to twenty minute carefully …

The Rhetoric And Promises Of Accountability (Lecture), Melvin J. Dubnick

Faculty Publications

This document discusses the conceptual challenges, historical roots, and cultural ambiguities of the term “accountability” and advocates for its careful reexamination and preservation in modern governance.

An Extension Of Elton's L(1)(N) Theorem To Complex Banach Spaces, S J. Dilworth, Joseph P. Patterson

Faculty Publications

No abstract provided.

Seeking Salvation For Accountability, Melvin J. Dubnick

Faculty Publications

This is a paper in defense of a concept that is threatened by its popularity and undermined by those who use it most. It is a call for a reexamination and reaffirmation of “accountability” from the perspective of its central role in modern governance. It is a plea for saving the concept of accountability from the abuses it suffers in the hands of friends and advocates. It is an effort at salvation for a concept that has lost its meaningful “soul” in a world filled with rhetoricians, reformers, and functionalists – all well intentioned, but each contributing to accountability’s fall …