Physical Sciences and Mathematics Commons^™

Thermal Links For The Implementation Of An Optical Refrigerator, John Parker, David Mar, Steven Von Der Porten, John Hankinson, Kevin Byram, Chris Lee, Michael K. Mayeda, Richard C. Haskell, Qimin Yang, Scott R. Greenfield, Richard I. Epstein

All HMC Faculty Publications and Research

Optical refrigeration has been demonstrated by several groups of researchers, but the cooling elements have not been thermally linked to realistic heat loads in ways that achieve the desired temperatures. The ideal thermal link will have minimal surface area, provide complete optical isolation for the load, and possess high thermal conductivity. We have designed thermal links that minimize the absorption of fluoresced photons by the heat load using multiple mirrors and geometric shapes including a hemisphere, a kinked waveguide, and a tapered waveguide. While total link performance is dependent on additional factors, we have observed net transmission of photons with …

Evaluation And Development Of Blackbird Repellents For Agricultural Applications, Scott J. Werner, Shelagh Tupper, George M. Linz, H. Jeffrey Homan

United States Department of Agriculture Wildlife Services: Staff Publications

We evaluated several registered fungicides and insecticides, and several natural compounds as candidate blackbird repellents for protecting agricultural production. We tested more than 750 red-winged blackbirds at the National Wildlife Research Center’s outdoor animal research facility in Fort Collins, CO to evaluate (1) their preference for treated versus untreated rice and sunflower seeds and (2) their consumption of seeds treated with varying concentrations of candidate repellents. Concentrations were varied between 10% and 200% of labeled application rates. With few exceptions, blackbirds discriminated between untreated seeds and seeds treated with one of the candidate repellents. We observed greatest repellency with caffeine …

Avian Use Of Rice-Baited Trays Attached To Cages With Live Decoy Blackbirds In Central North Dakota: Research Update, Jamison Winter, George M. Linz, William Bleier

United States Department of Agriculture Wildlife Services: Staff Publications

For decades, blackbird depredation of sunflower has been a problem. Sunflower growers consistently place blackbirds in the top tier of problems associated with growing sunflower in the northern Great Plains. Many non-lethal tactics have been employed in an attempt to protect ripening sunflower from foraging flocks of blackbirds. Thinning cattail-choked wetlands to reduce roosting habitat, using pyrotechniques to frighten feeding birds, planting Wildlife Conservation Sunflower Plots to lure bids away from commercial plots, applying taste repellents, and adapting cultural methods such as block planting to synchronize ripening are just a few such tactics. Even so, the numbers of blackbirds migrating …

Total Synthesis Of (±)-Quebrachamine Via [3+2] Cycloaddition And Efficient Chloroacetamide Photocyclization, Brian Pagenkopf, Barbora Bajtos

Chemistry Publications

The total synthesis of (±)-quebrachamine has been completed in 13 linear steps and 17.8 % overall yield. The indole core was constructed via a formal [3+2] dipolar cycloaddition between a functionalized nitrile and donor-acceptor cyclopropane, and the synthetically challenging nine-membered ring was secured by an efficient chloroacetamide photocyclization.

Assessment Of Endocrine And Gonadal Condition Of Male Largemouth Bass From Lake Mead, Nevada, Reynaldo Patino, Steven L. Goodbred, Erik Orsak, Jill A. Jenkins, Michael R. Rosen

Lake Mead Science Symposium

Las Vegas Bay (LVB) of Lake Mead receives combined flows of tertiary treated wastewater effluent, urban runoff, and groundwater from the Las Vegas metropolitan area. This study examined the potential for endocrine disrupting effects of these anthropogenic inputs on male largemouth bass (Micropterus salmoides). Adult male bass were collected at two sites within Lake Mead: Overton Arm (OA, reference site), and Las Vegas Bay (LVB). Post-spawn fish were collected in July 2007 (n = 6-10 per site) and pre-spawn fish in March 2008 (n = 13 per site). Post-spawn fish were characterized by regressed testes whereas pre-spawn bass had full-grown …

History Of Contaminant Inputs Into Lake Mead Derived From Sediment Cores, Michael R. Rosen, Peter C. Van Metre, David Alvarez, Kathy R. Echols, Steven L. Goodbred

Lake Mead Science Symposium

Assessing the changes in contaminant inputs (both organic and inorganic) over time is important in determining sources and sinks of these inputs. Variations in contaminant input were assessed in four sediment cores taken in 1998 from three different parts of Lake Mead (two from Las Vegas Bay and one from Overton Arm and Virgin Basin). Sediments were analyzed for major and trace elements, radionuclides, and organic compounds. Anthropogenic contaminant concentrations are greatest in Las Vegas Bay reflecting inputs from the Las Vegas urban area, although concentrations are low compared to sediment quality guidelines and to other USA lakes. One exception …

Monitoring Water Quality On Tributary Inflows To Lake Mead And On A Transect Of The Overton Arm, Jorge Arufe, Robert Burrows

Lake Mead Science Symposium

The USGS, in cooperation with the NPS and BOR (Bureau of Reclamation), is collecting water quality data to determine the temporal changes and spatial distributions of natural and anthropogenic compounds entering the Overton Arm of Lake Mead. These efforts and others already underway on the lake by BOR, USGS, and SNWA will aid in the development of a reservoir model of the lake. The effects of the flood flows on the water quality of the Overton Arm are largely unknown and necessary for model development and verification.

Water quality physical parameters are continuously monitored near the mouth of the Virgin …

Strategic Data Mining And Database Development For Research Projects At Lake Mead, Nevada-Arizona Usa, James Pollard, Gretchen M. Andrew

Lake Mead Science Symposium

“Water 2025” is a Department of Interior initiative designed to guide the management of scarce water resources in the American West. As an important Colorado River reservoir, Lake Mead is a fundamental component of Water 2025. For Water 2025 to achieve its goals, comprehensive knowledge is needed of historic and current Lake Mead water quality data. A task agreement between the National Park Service and the University of Nevada, Las Vegas provides for a strategic data mining project to identify research and monitoring projects on Lake Mead that have been conducted in the past, prioritize relevant projects, and ensure data …

Surface Water Monitoring For Fecal Indicator Bacteria In High-Use Sites Of The Lake Mead National Recreation Area, Patricia Cruz, Vanessa Stevens, Jessie Rinella

Lake Mead Science Symposium

The Lake Mead National Recreation Area incorporates 1.5 million acres, including Lake Mead and Lake Mohave. The abundance of recreational activities on Lakes Mead and Mohave can impact the contaminant levels in the water, potentially affecting the health of individuals in contact with the water. The purpose of this study was to review and synthesize information obtained for projects conducted by partner agencies from the Water 2025 Conservation Initiatives, specifically bacterial concentration in high-use areas. Surface water samples were collected between May and September, at 9 high-use sites from 2003 to 2007. Culture analysis was performed to determine the concentration …

Diversity Of Estrogen Degrading Microorganisms In Las Vegas Wash And Lake Mead, Nevada, Usa, Susanna Blunt, Jim Bruckner, Jenny C. Fisher, Duane P. Moser

Lake Mead Science Symposium

Endocrine disrupting chemicals (EDCs) are a subject of intense research as more studies reveal their persistence in the environment and detrimental effects on wildlife. Steroid hormones, including the natural and synthetic estrogens estrone (E1), 17-beta-estradiol (E2) and 17- alpha-ethinyl estradiol (EE2), are among the most bioactive and have been detected at low concentrations in waterways downstream from wastewater treatment plants. Las Vegas Wash, a stream flowing into Lake Mead and fed primarily by treated wastewater, provides a unique experimental system in which to study the role microorganisms play in the fate and dispersal of these compounds in surface waters.

Lake Mead Science Symposium, January 13 An 14, 2009, Las Vegas, Nevada: Program, Kent Turner

Lake Mead Science Symposium

Conference program for the 2009 Lake Mead Science Symposium. Includes abstracts of presentations, registration packet, exhibitor and sponsor information.

Lake Mead Symposium Plenary Schedule, Kent Turner

Lake Mead Science Symposium

Preliminary schedule for the symposium.

Dynamical Non-Ergodic Scaling In Continuous Finite-Order Quantum Phase Transitions, S. Deng, G. Ortiz, L. Viola

Dartmouth Scholarship

We investigate the emergence of universal dynamical scaling in quantum critical spin systems adiabatically driven out of equilibrium, with emphasis on quench dynamics which involves non-isolated critical points (i.e., critical regions) and cannot be a priori described through standard scaling arguments nor time-dependent perturbative approaches. Comparing to the case of an isolated quantum critical point, we find that non-equilibrium scaling behavior of a large class of physical observables may still be explained in terms of equilibrium critical exponents. However, the latter are in general non-trivially path-dependent, and detailed knowledge about the time-dependent excitation process becomes essential. In particular, …

The Most Representative Composite Rank Ordering Of Multi-Attribute Objects By The Particle Swarm Optimization, Sudhanshu K. Mishra

Sudhanshu K Mishra

Rank-ordering of individuals or objects on multiple criteria has many important practical applications. A reasonably representative composite rank ordering of multi-attribute objects/individuals or multi-dimensional points is often obtained by the Principal Component Analysis, although much inferior but computationally convenient methods also are frequently used. However, such rank ordering – even the one based on the Principal Component Analysis – may not be optimal. This has been demonstrated by several numerical examples. To solve this problem, the Ordinal Principal Component Analysis was suggested some time back. However, this approach cannot deal with various types of alternative schemes of rank ordering, mainly …

Comparison Of Polarization Consistent And Correlation Consistent Basis Sets For Noncovalent Interactions, Adel M. Elsohly, Gregory S. Tschumper

Chemistry Faculty Research & Creative Works

The convergence of the polarization consistent family of basis sets to the MP2 complete basis set (CBS) limit has been examined for the dissociation energies of five weakly bound clusters: (HF)₂, (HF)₃, (H₂O)₂, (H₂O)₃, and (C₂H₂)₂. MP2 results obtained with two series of polarization consistent basis sets and the analogous series of Dunning's correlation consistent basis sets are compared to the CBS limits obtained with the explicitly correlated MP2-R12 method. Although the polarization consistent basis sets do converge systematically to the CBS …

Walking Box Ranch Planning And Design Quarterly Progress Report: Period Ending April 10, 2009, Margaret N. Rees

Walking Box Ranch

• UNLV faculty and PLI scientists and interpreters participated in the 50% Design Concept Plan meeting, March 25-27 at UNLV-PLI and Walking Box Ranch (WBR), and provided comments toward proposed concepts for the museum and field, research, and training center at Walking Box Ranch.
• UNLV is continuing to work with the Architectural Resources Group (ARG) under our SAT grant, to complete Master and Preservation Plans that will guide the SNPLMA-funded museum and field station projects now underway.
• The National Historic Register nomination process, initiated under the SAT grant, was approved and WBR was placed on the NPS National Register of Historic …

Tilted Parallel Dielectric Slab As A Multilevel Attenuator For Incident P- Or S-Polarized Light, R. M.A. Azzam

Electrical Engineering Faculty Publications

Under the condition of first-order blooming, a parallel dielectric slab, which is inserted in the path of an obliquely incident p- or s-polarized light beam, introduces multiple discrete attenuation levels given by 1/3, 4/27, 4/243,...... in reflection and 4/9, 4/81, 4/729,...... in transmission. These attenuation levels are independent of the slab refractive index, incident p or s linear polarization, or the presence of identical transparent surface coatings at the front and back sides of the slab. Therefore, the tilted slab provides multidecade reflectance and attenuation reference values that can be used in calibrating spectrophotometers and filters, and also …

Hubble Space Telescope Observations Of The Quasar Pks 0637-752: Equipartition Electron-Proton Jet From The Most Complete Spectral Coverage To Date, Kushal T. Mehta, Markos Georganopoulos, Eric S. Perlman, Charles A. Padgett, George Chartas

Aerospace, Physics, and Space Science Faculty Publications

We present new Near-Infrared Camera and Multi-Object Spectrometer and attitude control system observations of the quasar jet PKS 0637-752, and we use them, together with existing multiwavelength observations, to produce the most complete spectral coverage of the source to date. We explore the implications of these observations in the context of models for the jet X-ray emission. By relaxing the assumption of equipartition, we undertake an exhaustive study of the parameter space for external Compton off the cosmic microwave background (CMB) (EC/CMB) model. We find that the multiwavelength observations exclude a magnetic-field-dominated jet. Using the method proposed by Georganopoulos et …

Corso Di Analisi Delle Serie Storiche A.A 2008/2009- Laboratorio Di Stata: Lezione 4 –Analisi Classica Delle Serie Storiche Ii (Formato Pdf), Carlo Drago

Carlo Drago

No abstract provided.

Corso Di Analisi Delle Serie Storiche A.A 2008/2009- Laboratorio Di Stata: Lezione 5 –Analisi Moderna Delle Serie Storiche (Formato Pdf), Carlo Drago

Carlo Drago

No abstract provided.

Entrapment Of Hydrophobic Drugs In Nanoparticle Monolayers With Efficient Release Into Cancer Cells, Ck Kim, P Ghosh, C Pagliuca, Zj Zhu, S Menichetti, Vm Rotello

Vincent Rotello

Gold nanoparticles functionalized with water-soluble zwitterionic ligands form kinetically stable complexes with hydrophobic drugs and dyes. These drugs and dyes are efficiently released into cells, as demonstrated through fluorescence microscopy and cytotoxicity assays. Significantly, there is little or no cellular uptake of particle, making these low toxicity particles promising for delivery applications.

Controlling Interlayer Exchange Coupling In One-Dimensional Fe/Pt Multilayered Nanowire, Puspamitra Panigrahi, Ranjit Pati

Department of Physics Publications

We report a first-principles density-functional study of interlayer exchange coupling (IEC) in one-dimensional Fe/Pt multilayered nanowire. The magnetic moment of the interfacial Fe atom in the Fe/Pt multilayered nanowire is found to be higher than that of the Fe atom away from the interface. A mechanism based on multistep electron transfer between the layers and spin flip within the layer is proposed to explain the magnetic-moment enhancement at the interface. The calculated IEC and magnetoresistance are found to switch signs as the width of the nonmagnetic Pt spacer varies. Depending on the width of the Pt spacer, the competition among …

Phenomena Induced By Powerful Hf Pumping Towards Magnetic Zenith With A Frequency Near The F-Region Critical Frequency And The Third Electron Gyro Harmonic Frequency, N. F. Blagoveshchenskaya, Herbert C. Carlson, V. A. Kornienko, T. D. Borisova, M. T. Rietveld, T. K. Yeoman, A. Brekke

Faculty publications

Multi-instrument observational data from an experiment on 13 October 2006 at the EISCAT/HEATING facility at Tromsø, Norway are analysed. The experiment was carried out in the evening hours when the electron density in the F-region dropped, and the HF pump frequency fH was near and then above the critical frequency of the F2 layer. The distinctive feature of this experiment is that the pump frequency was just below the third electron gyro harmonic frequency, while both the HF pump beam and UHF radar beam were directed towards the magnetic zenith (MZ). The HF pump-induced phenomena were diagnosed with several instruments: …

An Introduction To Enumeration Schemes, Lara Pudwell

Lara K. Pudwell

No abstract provided.

Anti-De Sitter Space From Supersymmetric Gauge Theory, Simon Catterall

Physics - All Scholarship

We construct a four dimensional Yang-Mills theory with {\cal N}=4 twisted supersymmetry whose classical vacua correspond to four dimensional anti-de Sitter space. The theory utilizes a complex gauge field whose real part is a spin connection which is used to enforce local Lorentz invariance. The imaginary part of the connection can then be interpreted as a vierbein. The topological construction ensures that the partition function and classical vacua are independent of the background geometry. Additionally a supersymmetric and gauge invariant lattice construction is possible yielding a non-perturbative definition of the theory.

Basic Statistics-I, Durgesh Chandra Pathak

Durgesh Chandra Pathak

It's a presentation that I prepared for JRF-students in Development Studies.

Predicting The Geodetic Signature Of Mw 8 Slow Slip Events, Brendan J. Meade, John P. Loveless

Geosciences: Faculty Publications

Elastic dislocation models of geodetic measurements

above subduction zones have led to the identification of

MW 6.0– 7.2 slow slip events (SSEs) that release elastic

strain over periods of days to months, but great (MW 8)

SSEs have remained unidentified. We extrapolate

observations of SSE duration and slip magnitude to show

that slip velocity decreases with event magnitude and

predict that the slip velocity of MW 8 SSEs is 50 mm/yr.

The slip velocity for great SSEs may never exceed the

plate convergence rate and thus never produce a reversal

in trench perpendicular motion. Instead, geodetically

constrained estimates of apparent …

A Multiagent Framework For Human Coalition Formation, Nobel Khandaker, Leen-Kiat Soh

CSE Technical Reports

Human users form coalitions to solve complex tasks and earn rewards. Examples of such coalition formation can be found in the military, education, and business domains. Multiagent coalition formation techniques cannot be readily used to form human coalitions due to the unique aspects of the human coalition formation problem, e.g., uncertainty in human user behavior and changes in human user behaviors due to human learning. Thus, a multiagent system designed to form human coalitions has to solve a learning problem, that is further made difficult by the limited learning opportunities and usability issues (i.e., actions or decisions being perceived as …

Multiagent Simulation Of Collaboration And Scaffolding Of A Cscl Environment, Nobel Khandaker, Leen-Kiat Soh

CSE Technical Reports

Multiagent techniques improves student learning in Computer-Supported Collaborative Learning (CSCL) environments through multiagent coalition formation and intelligent support to the instructors and students. Researchers designing the multiagent tools and techniques for CSCL environments are often faced with high cost, time, and effort required to investigate the effectiveness of their tools and techniques in large-scale and longitudinal studies in a real-world environment containing human users. Here, we propose SimCoL, a multiagent environment that simulates collaborative learning among students and agents providing support to the teacher and the students. Our goal with SimCoL is to provide a comprehensive testbed for multiagent researchers …

Agent Sensing In Limited Resource Environments, Adam Eck, Leen-Kiat Soh

CSE Technical Reports

One of the key challenges for multiagent systems (MAS) is optimizing performance in limited resource environments. Previous research in this area has focused on the problems of 1) resource allocation and arbitration, and 2) bounded rationality, which describe the relationship between resource constraints and both agent reasoning and actuation. However, less work exists ad-dressing the effect of consuming resources during agent sensing, particularly two important tradeoffs. First, sensing can reduce resource availability, resulting in a tradeoff between overall system performance and an agent’s sensing behavior (the Performance Tradeoff). Second, consuming resources during sensing can alter the outcome of the measurement …