Physical Sciences and Mathematics Commons^™

Periodicity And Disorder, Simeon D. Simeonov

Dissertations

We have studied four examples of periodicity and disorder in nature and the phenomena associated with them.

In the first chapter of the dissertation we present an introduction to this work.

In the second chapter, the photonic band structures of two types of zinc blend structures are computed using the plane wave expansion method. Both structures are formed from an array of dielectric spheres in a vacuum background. In a first type zinc blend structure the spheres have the same size but different dielectric constants. In a second type of structure we keep the dielectric contrast of the spheres the …

Magnetic And Mössbauer Spectral Study Of Mixed Valent La₀.₂Sr₀.₈Cu₀.₂Fe₀.₈O2.68 And Related Perovskites, Gary J. Long, Dimitri Hautot, Amitabh Mohan, Ingeborg Kaus, Harlan U. Anderson, Fernande Grandjean

Chemistry Faculty Research & Creative Works

The La_0.2Sr_0.8Cu_1-xFe_xO _3-δ perovskites are important because they are mixed electron and oxygen anion conductors and thus are able to serve as dense oxygen separation membranes. In order to better understand the mechanism for this separation a Mössbauer spectral study has been carried out to determine the ratio of iron(III) to iron(IV) in these mixed valent compounds. The Mössbauer spectra of La_0.2Sr_0.8Cu_0.2Fe_0.8O _3-δ obtained between 4.2 and 78 K reveal that its Néel temperature is ~75 K and the two well-resolved magnetic sextets observed …

Atomic Structure And Magnetism Of Ordered And Disordered Al₀.₅Fe₀.₅₋ₓmnₓ Alloys, V. G. Harris, D. J. Fatemi, K. B. Hathaway, Q. Huang, Amitabh Mohan, Gary J. Long

Chemistry Faculty Research & Creative Works

The equiatomic FeAl alloy has been modified by partial substitution of Mn for Fe, and its magnetic and structural properties investigated by neutron diffraction (ND), x-ray absorption fine structure (XAFS) spectroscopy, Mössbauer spectroscopy (MS), and SQUID magnetometry both for the ordered (B2) and disordered states. The unit cell volume is measured to increase linearly with Mn concentration. XAFS measurements indicate local structural displacements occur at the Mn sites in both ordered and disordered states that may act to frustrate long-range magnetic order (LRMO). Although MS and ND show no evidence of LRMO, SQUID magnetometry indicates an induced movement in the …

Coordinated Water Resource Planning For The Sandia Basin - A Perspective Into Regional Water Planning Needs, Jeffrey L. Peterson

Water Resources Professional Project Reports

Regional water planning, a strategy adopted by the State Legislature to protect New Mexico's scant water resources from depletion and mismanagement, is evident in various water planning efforts that draw upon the cooperation of interested and vested stakeholders at the local level. Regional water-planning efforts that are currently underway can be found in the Estancia Basin, portions of the Rio Grande Basin, and the Tularosa Basin. This project utilized these water-planning efforts in order to assist in developing the basis of a regional water plan for the Sandia Basin.

Cheyenne County Test-Hole Logs: Nebraska Water Survey Test-Hole Report No. 17, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

In 1930, the Conservation and Survey Division (CSD) of the University of Nebraska and the United States Geological Survey began a program of cooperative groundwater studies in Nebraska. Since then test drilling by use of rotary drilling equipment has been an integral part of that program. This report contains logs of all the test-holes drilled in the county under the program as well as those drilled by the Conservation and Survey Division with financial assistance from other government agencies. Also included are logs of test-holes drilled by cooperators with the South Platte Natural Resources District.

The maps in this report …

Excitation Of Morphology-Dependent Resonances And Van De Hulst's Localization Principle, James A. Lock

Physics Faculty Publications

When a laser beam scatters from a microparticle whose shape deviates from that of a sphere, a number of partial waves of the incident beam couple to a given partial wave of the scattered and interior fields. As a result, partial-wave coupling caused by small surface irregularities of a liquid droplet provides the mechanism for exciting low-radial-order morphology-dependent resonances. (C) 1999 Optical Society of America.

Golf Courses In Southern Nevada Will Significantly Impact The Water Management Efforts By Using Recycled Water Rather Than Potable Water To Irrigate Their Turf, Sean D. Ainsworth

UNLV Theses, Dissertations, Professional Papers, and Capstones

As the number of people continually move to the Las Vegas Valley and take up residence, the possibility of "running out of water" can become a reality. Having large water users (i.e. golf courses) irrigate their turf with recycled water, they will significantly impact the water management efforts in the Las Vegas Valley. When each course is irrigating their turf with recycled water, this will help ease the drinking water demand in the valley, especially during the peak demand season (summer).

Novel Precursors For Chemical Vapor Deposition Of Copper Metal, Zuzanna T. Cygan

Honors Theses

No abstract provided.

Synthesis And Antimalarial Activity Of 11 Dispiro-1,2,4,5-Tetraoxane Analogues Of Wr 148999. 7,8,15,16-Tetraoxadispiro[5.2.5.2]Hexadecanes Substituted At The 1 And 10 Positions With Unsaturated And Polar Functional Groups, Yuxiang Dong, F. Hoffmann-Laroche Ltd., Jacques Chollet, Ronald Kaminsky, James K. Wood, Jonathan L. Vennerstrom

Chemistry Faculty Publications

Eleven novel dispiro-1,2,4,5-tetraoxanes 3 bearing unsaturated and polar functional groups were designed to enhance the oral antimalarial activity of the prototype tetraoxane 2 (WR 148999). With the exception of 3g and 3h, tetraoxanes 3 were available via the peroxidation of corresponding cyclohexanone derivatives in H2SO4/CH3CN. Tetraoxanes 3g and 3h were prepared by hydrolysis of ester tetraoxanes 3e and 3i, respectively. Five of the 11 tetraoxanes were inactive, but six tetraoxanes had IC₅₀ values of 6-26 nM against the K1 and NF54 strains of Plasmodium falciparum compared to corresponding IC₅₀ values of 28 and 39 nM for …

Airport Bird Threat In North America From Large Flocking Birds (Geese) (As Viewed By An Engine Manufacturer)-- Part 2, Thomas Alge

Bird Strike Committee-USA/Canada Joint Annual Meeting: 1st (1999)

Although the perceived threat from the growing geese population in North America has been increasing in recent years (and needs to be addressed), progress appears to have been made in reducing the damaging bird strikes through improved awareness and more effective airport bird hazard control programs worldwide. The following statistics attempt to quantify this progress for selected geographic regions. Reasons for the improvements and lessons learned, if known, are mentioned.

Airport Bird Threat In North America From Large Flocking Birds (Geese) (As Viewed By An Engine Manufacturer)--Part 3, Thomas Alge

Bird Strike Committee-USA/Canada Joint Annual Meeting: 1st (1999)

This paper focuses on the increasing threat to aircraft and engines posed by the recorded growth in geese populations in North America. Service data show that goose strikes to aircraft and engines are increasing, especially in North America - consistent with the growing resident geese populations estimated by the USDA. Airport managers, along with the governmental authorities, need to develop a strategy to address this large flocking bird issue. This paper also presents statistics on the overall status of the bird threat for birds of all sizes in North America relative to other geographic regions. Overall, the data show that …

Evolution Of The Dfw International Airport Wildlife Management Program –- Lessons Learned, Curt W. Kuehner, John R. Alexander

Bird Strike Committee-USA/Canada Joint Annual Meeting: 1st (1999)

On January 7, 1997, Dallas-Fort Worth International Airport experienced its first large bird strike event, involving the collision of over 350 European starlings with an American Airlines MD-80. This prompted a serious assessment of existing wildlife control procedures, and eventually resulted in the formation of the DFW Wildlife Control Program. The number of reported strikes has dropped from 157 in 1996 to 52 in 1998. The success of DFW’s program is the result of long, hard hours and extensive trial and error. However, wildlife management personnel at other airfields do not have to go through all the growing pains and …

Bird Proofing Hangars, Carl Lahser, Will Summers

Bird Strike Committee-USA/Canada Joint Annual Meeting: 1st (1999)

Birds can damage flight line structures and create serious health and safety risks for workers. Many of our structures are old and not designed as bird proof. Many controllable factors are discussed but the underlying principles are to deny birds food, water and access to resting/nesting areas. Various "tools" are discussed including grounds and building maintenance, landscaping, personnel management, chemical deterrents, poisons, and shooting or trapping.

On The Run: Unexpected Outcomes Of Random Events [Post-Print], Mark P. Silverman

Faculty Scholarship

When purportedly random processes give rise to surprisingly nonrandom outcomes, how can one tell whether the process are truly random? One way exploits the relatively little-known method of runs. We discuss the perplexing probability problem that brought this procedure to our attention, and our experimental tests of random processes produced by (a) numerical algorithm, (b) coin selection, and (c) nuclear decay.

Pretty Tree Bench Vegetation Project, Draft Environmental Impact Statement, Usda Forest Service

All U.S. Government Documents (Utah Regional Depository)

This Draft Environmental Impact Statement documents the analysis of the No Action, Proposed Action, and three action alternatives developed for the Pretty Tree Bench Project area. The Proposed Action and action alternatives considered in detail, are consistent with current management direction. Each alternative responds differently to the issues associated with the Proposed Action.

The Proposed Action prescribes disturbances within a number of different vegetation types throughout the project area. One disturbance practice uses prescribed fire. The acres of treatment by vegetation type through the use of prescribed fire are: Sagebrush (200-250 acres), Gambel Oak (450-500 acres), Pinyon/Juniper (3000-3500 acres), Ponderosa …

Race, Ethnicity And Use Of The National Park System, Dr. Myron Floyd, National Park Service, Department Of The Interior

All U.S. Government Documents (Utah Regional Depository)

This paper reviews the social science literature on racial and ethnic minority use of the National Park System. Four theoretical perspectives are examined--the marginality hypothesis, subcultural hypothesis, assimilation theory, and the discrimination hypothesis. Each perspective is described, and its strengths and limitations discussed. Research on race, ethnicity, and participation in outdoor recreation is also examined. Studies consistently show that racial and ethnic groups visit national parks and participate in recreation activities at differing rates. The style and pattern of park use also vary among racial and ethnic groups. Social science research on this topic can help park managers serve the …

Radar And Satellite Global Equatorial F-Region Vertical Drift Model, L. Scherliess, Bela G. Fejer

Bela G. Fejer

We present the first global empirical model for the quiet time F region equatorial vertical drifts based on combined incoherent scatter radar observations at Jicamarca and Ion Drift Meter observations on board the Atmospheric Explorer E satellite. This analytical model, based on products of cubic-B splines and with nearly conservative electric fields, describes the diurnal and seasonal variations of the equatorial vertical drifts for a continuous range of all longitudes and solar flux values. Our results indicate that during solar minimum, the evening prereversal velocity enhancement exhibits only small longitudinal variations during equinox with amplitudes of about 15–20 m/s, is …

In Situ Measurement Of The Aerosol Size Distribution In Stratospheric Solid Rocket Motor Exhaust Plumes, Martin N. Ross, Philip D. Whitefield, Donald E. Hagen, Alfred R. Hopkins

Chemistry Faculty Research & Creative Works

The concentration and size distribution of aerosol in the stratospheric exhaust plumes of two Space Shuttle rockets and one Titan IV rocket were measured using a two component aerosol sampling system carried aboard a WB‐57F aircraft. Aerosol size distribution in the 0.01 µm to 4 µm diameter size range was measured using a two component sampling system. The measured distributions display a trimodal form with modes near 0.005 µm, 0.09 µm, and 2.03 µm and are used to infer the relative mass fractionation among the three modes. While the smallest mode has been estimated to contain as much as 10% …

The Feasibility Of Controlling The Brown Treesnake In Small Plots, Gordon H. Rodda, Thomas H. Fritts, Earl W. Campbell Iii

United States Department of Agriculture Wildlife Services: Staff Publications

There is an urgent need to provide snake-free or snake-reduced habitats for the wildlife species on Guam that have declined or disappeared as a result of predation by the Brown Treesnake, Boiga irregularis (Savidge, 1987; Fritts, 1988; Rodda and Fritts, 1992; Rodda et al., this volume, Chap. 2). At present, we know of no practical techniques for reducing or eradicating the snake throughout Guam, a densely populated island of 54,100 ha. Conserving native wildlife and reducing the incidences of snakes boarding ship and aircraft may not require the elimination of snakes from the entire island, however. Elimination of snakes from …

An Overview Of The Biology Of The Brown Treesnake* (Boiga Irregularis), A Costly Introduced Pest On Pacific Islands, Gordon H. Rodda, Thomas H. Fritts, Michael J. Mccoid, Earl W. Campbell Iii

United States Department of Agriculture Wildlife Services: Staff Publications

The 20-30 species of the genus Boiga (Colubridae, Boiginae) range from tropical Africa through southern Asia to Melanesia and Australia (Leviton, 1968). Collectively, they are known as catsnakes, mangrove snakes, or treesnakes (Obst et al., 1988; Greene, 1989). The common name "catsnakes" is sometimes used for snakes in the genus Telescopus as well (Obst et 1, 1988).

Members of the genus Boiga are nocturnal, oviparous, opisthoglyphic, euryphagic, and slender; they have vertical elliptical pupils (thus “cat” snakes) set in large eyes, and short, blunt heads that are noticeably larger than their necks. With one exception they are arboreal or semiarboreal …

The John Muir Newsletter, Spring 1999, The John Muir Center For Regional Studies

Muir Center Newsletters (1981-2015)

NEWSLETTER c Reconstructing John Mum's First Public Lecture, Sacramento, 1876 by Steve Pauly, Pleasant Hill, California (Editor's Note: In our previous issue, Steve Pauley's article placed John Muir's first public talk in context. Wmere is his re-creation of some sections of the talk.) n the beginning of the long glacial winter, the lofty Sierra seems to have consisted of one vast undulated wave, in which a thousand separate mountains, with their domes and spires, their innumerable canons and lake basins, lay concealed. In the development of these, the Master Builder chose for a tool, not the earthquake nor lightning to …

Graphical Display And Data Structure For Virtual Prototyping, David William Manry

Doctoral Dissertations

One of the goals of engineering firms is to bring better products to market faster. Although concurrent engineering can aid in this endeavor, it requires that all areas of an organization work simultaneously. Thus, current product data must be accessible to everyone.

Virtual prototyping allows this simultaneous exchange of information. Virtual prototyping not only replaces the physical model in product development with a virtual model, but also it goes further by allowing data associated with each part of the model to be accessed. This data is not limited to just geometric properties but could contain other quantifiable properties, such as …

Binary Nucleation Kinetics. Iv. Directional Properties And Cluster Concentrations At The Saddle Point, Gerald Wilemski

Physics Faculty Research & Creative Works

Using a new approach, Stauffer's expression for the rate of steady state binary nucleation and Trinkaus's expression for the steady state cluster concentrations f are derived directly from the diffusion equation that governs the evolution of f in composition space. The behavior of φ (≡f/N, where N is the equilibrium cluster concentration) is explored since this function provides a characterization of the nucleating binary system that, to lowest order, is independent of the actual composition of the mother phase. The angle ω that describes the direction of ▽ φ at the saddle point differs, in general, from the angle φ …

กิจกรรมสิ่งแวดล้อม

Thai Environment

No abstract provided.

สรุปข่าวสิ่งแวดล้อม : สถานการณ์สิ่งแวดล้อมในรอบปี่ พ.ศ. 2541

Thai Environment

No abstract provided.

สัมภาษณ์ : คุรทนง ศรีจิตร์ กรรมการและผู้จัดการโครงการ บริษัทสหพัฒนาอินเตอร์โฮลดิ้ง จำกัด (มหาชน)

Thai Environment

No abstract provided.

โครงการจัดตั้งเครือข่ายศูนย์วิจัยร่วมอุตสาหกรรม-มหาวิทยาลัย ด้านการจัดการสิ่งแวดล้อมและวัตถุอันตราย จุฬาลงกรณ์มหาวิทยาลัย, วสันต์ พงศาพิชญ์

Thai Environment

No abstract provided.

การป้องกันผลกระทบจากการพัฒนาอุตสาหกรรมต่อสิ่งแวดล้อม, ธรรมนูญ โรจนะบุรานนท์

Thai Environment

No abstract provided.

การใช้น้ำเพื่อการเกษตร, สุจินต์ พนาปวุฒิกุล

Thai Environment

No abstract provided.

วันอนุรักษ์น้ำโลก, ชัยรัตน์ วงศ์กิจรุ่งเรือง

Thai Environment

No abstract provided.