Physical Sciences and Mathematics Commons^™

สรุปข่าวสิ่งแวดล้อม

Thai Environment

No abstract provided.

ข่าวประชาสัมพันธ์

Thai Environment

No abstract provided.

Entech '96 Show Preview

Thai Environment

No abstract provided.

ไขปัญหาสารพัน

Thai Environment

No abstract provided.

ข่าวผลิตภัณฑ์

Thai Environment

No abstract provided.

ประวัติผู้เขียน

Thai Environment

No abstract provided.

A Comparative Analysis Of Viable Solar Thermal Technologies For Solar Field Development And Commercialization, Sean M. Crawford

UNLV Theses, Dissertations, Professional Papers, and Capstones

Diminishing fossil fuels and concerns about the quality of the environment has lead the recent drive to establish a commercialized solar field in Southern Nevada. The competing solar thermal technologies for the Solar Enterprise Zone (SEZ) are Parabolic Dish-Stirling, Central Receiver Power Towers, and Parabolic Trough Systems. It is important to compare the technologies based on the guidelines set by the Corporation for Solar Technology and Renewable Resources. The variables weighted are solar conversion performances, initial capital investment, operation and maintenance costs, water and land use, and electricity production costs. All technologies have been proven to viable power sources and …

Error Correction Via A Post-Processor For Continuous Speech Recognition, Eric K. Ringger, James F. Allen

Faculty Publications

This paper presents a new technique for overcoming several types of speech recognition errors by post-processing the output of a continuous speech recognizer. The post-processor output contains fewer errors, thereby making interpretation by higher-level modules, such as a parser, in a speech understanding system more reliable. The primary advantage to the post-processing approach over existing approaches for overcoming SR errors lies in its abilityto introduce options that are not available in the SR module’s output. This work provides evidence for the claim that a modern continuous speech recognizer can be used successfully in “black-box” fashion for robustly interpreting spontaneous utterances …

Characterization And Catalytic Properties Of Sulfated Zirconia, Melody Bi

Masters Theses & Specialist Projects

Sulfated zirconia has attracted extensive attention due to its superactivity to isomerize alkane and alkenes. Platinum or iron/manganese promoted sulfated zirconia has been shown to increase the reaction rate. These catalysts are normally activated to 650-725°C in air before use. Through on-line analysis of evolved gas species during dynamic heating of the catalysts, some significant information can be obtained concerning the activation mechanism. In the present investigation, combined TG-FTIR, TG-MS and TGDTA techniques were utilized to measure the weight loss of the samples, analyze the evolved gas species and to monitor the phase transformation temperature of the solid. Four samples …

Polarization Stability And Dynamics In A Model For A Polarization-Isotropic Laser That Goes Beyond Third-Order Lamb Theory, N. B. Abraham, Mark Matlin, R. S. Gioggia

Physics Faculty Research and Scholarship

Instabilities and dynamical pulsations are common features of solutions of a model that includes the material variable dynamics for a laser with a polarization isotropic resonator and with a homogeneously broadened j=1 --> j=0 transition. These resemble in some respects features found in third-order Lamb theories under anisotropic conditions, such as splitting of the optical field into two relatively independent orthogonally polarized modes with different optical frequencies. At higher intensities the amplitudes and frequencies of these modes exhibit such strong coupling that a ''two-mode'' description loses its usefulness or effectiveness. Various periodic attractors with strong intensity and polarization pulsations are …

Gnarly Rantings About The Hacker And The Ants, Rudy Rucker

SWITCH

The article is an excerpt from Rucker’s book “The Happy Mutant”. It begins with his reflection of his career with GoMotion. He discusses the relation that he saw between design and cyberspace. Later he discusses his experience with a game a colleague found on the net: a virtual world where player is an ant. He talks about the struggles he goes through in this virtual world because of game difficulty and poor visuals. He ties it all in with how the Silicon Valley works in a similar way, and is filled with hackers and programers all needing each other to …

Gnarled Defined, Rudy Rucker

SWITCH

The article is a reflection of the author’s conception of the term ‘gnarly’, extending the term’s meaning from its origins in California surfer slang. 'Gnarly' is often used in a colloquial context, however, the author believes that the term is able to be used in an academic field as it pertains to outcomes and results of equations. Discussions towards the application of the term 'gnarly' showcase how it can be used in a scientific, mathematical, and artistic context through seemingly random patterns. In order to be gnarly, things must lie and exist between the realm of orderly and chaotic often …

What Limits Tailed Frog Tadpole Density And Distribution In Western Montana Streams?, Megan Barker

Undergraduate Honors Capstone Projects

We explored the possible limitation of temperature and other habitat features on tailed frog tadpole populations in northwestern Montana. We sampled densities and habitat features in two regions with different climatic regimes and in streams with and without tadpoles, expecting larger density and size in the warmer region. We also expected habitat conditons to be more optimal (higher gradient, swifter velocity, and less canopy cover) in streams with tadpoles. Temperature appeared to positively influence tadpole size, though both tadpole size and density were strongly correlated with other variables. Density was correlated with gradient, canopy, depth, and elevation, whereas length was …

Integrated Multimedia Timeline Of Medical Images And Data For Thoracic Oncology Patients, Denise R. Aberle, John David N. Dionisio, Michael F. Mcnitt-Gray, Ricky K. Taira, Alfonso F. Cárdenas, Jonathan G. Goldin, Kathleen Brown, Robert A. Figlin, Wesley W. Chu

Computer Science Faculty Works

A prototype multimedia medical database has been developed to provide image and textual data for thoracic oncology patients undergoing treatment of advanced malignancies. The database integrates image data from the hospital pieture archiving and communication system with textual reports from the radiology information system, alphanumeric data contained in the hospital information system, and other electronic medical data. The database presents information in a timeline format and also contains visualization programs that permit the user to view and annotate radiographic measurements in tabular or graphic form. The database provides an efficient and intuitive display of the changing status of oncology patients. …

A Survey Of Employees Of The United States Department Of Agriculture's Animal Damage Control Program, Susan A. Schroeder

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study examined the attitudes of employees of the United States Department of Agriculture's Animal Damage Control (ADC) Program. This research examined ADC employees' attitudes about wildlife, the ADC program and ADC employment, wildlife damage management methods, euthanasia and the killing process, and the role of various public and private groups on ADC policy. This study also applied the theory of organizational capture to the ADC program to test its utility in explaining the attitudes and behaviors of employees. Results were based on a survey of ADC employees conducted in January 1995.

Survey responses were analyzed to explore associations between …

The Influence Of Forest Fragmentation And Landscape Pattern On American Martens And Their Prey, Christina D. Hargis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Habitat fragmentation occurs when large tracts of an orginal habitat are replaced by smaller patches of two or more habitat types, largely through human activities. I studied the behavior of six measures of landscape pattern that seemed appropriate for quantifying fragmentation, and used these measures to investigate the effects of forest fragmentation on American martens (Martes americana) and their prey. The measures I selected were edge density, contagion, mean nearest neighbor distance between patches, mean proximity index, perimeter-area fractal dimension, and mass fractal dimension. To test the behavior of these measures with a variety of landscape patterns, I …

Adaptive Density Estimation Based On The Mode Existence Test, Nizar Sami Jawhar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The kernel persists as the most useful tool for density estimation. Although, in general, fixed kernel estimates have proven superior to results of available variable kernel estimators, Minnotte's mode tree and mode existence test give us newfound hope of producing a useful adaptive kernel estimator that triumphs when the fixed kernel methods fail. It improves on the fixed kernel in multimodal distributions where the size of modes is unequal, and where the degree of separation of modes varies. When these latter conditions exist, they present a serious challenge to the best of fixed kernel density estimators. Capitalizing on the work …

Thermodynamics And Kinetics Of Small Molecule Binding To [Cyclopentadienyl-Ru-No] And [Rh-Co] Electrophilic Centers, Anna Svetlanova

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This work is concentrated on the thermodynamic and kinetic aspects of water, alcohols, alkyl halides, ethers, and lactones bound and activated by the electrophilic [Cp'Ru(N0)]⁺² and [Cp’Ru (NO)(CH₃)] + centers (Cp' = cyclopentadienyl group). Counterions in these systems include OSO₂CF₃- (OTf`) and [(3, 5-(CF₃)₂C₆H₃)₄B]- ([BAr₄']-). The displacement of OTf- in Cp'Ru(N0) (0Tf)2 by H20 in dichloromethane is exothermic but entropically unfavorable due to the required reorganization of the solvent cage around released triflate ions. Thermodynamic parameters are also determined for OTf …

Paleoenvironmental And Stratigraphic Interpretation Of The Middle Cambrian Ute Formation, Northern Utah, Keith E. Eagan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Middle Cambrian Ute Formation includes some 200 m of cyclically alternating carbonates and mud rocks. These are arranged in eight to nine, meter-scale, shallowing-upwards packages, representing deposition under predominantly subtidal conditions. The packages consist of vertical sequences of shale, silty limestone, oncolitic packstone, and oolitic grainstone that exhibit little variance in this general pattern. Small-scale unconformities separate the packages. The inferred depositional environment consists of an intrashelf basin that has a peritidal platform near its margins. The craton, which supplied most of the terrigenous sediment, was situated to the south (Cambrian orientation), and located near the equator. One cycle …

Structural Analysis Of The Mitten Park Reverse Fault And Related Deformation In Dinosaur National Monument, Northwestern Colorado And Northeastern Utah, Clint M. Brown

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An integrated field and structural analysis of the Mitten Park fault-fold structure, northwestern Colorado and northeastern Utah, examines its structural origin. The Mitten Park structure is a modified fault-propagation-fold. This new model incorporates faulting, folding, and fracturing in one deformational event to produce the Mitten Park fault and associated monocline.

The largest structure in the study area is the Mitten Park fault and associated monocline. The Mitten Park fault has approximately 127 meters (415 feet) of net slip, strikes S28°W and dips 55°WNW. In the footwall, net shortening was accommodated by reverse and normal faulting. Faulting was the result of …

Pre-Late-Wisconsin Glacial History Of The Naknek River Valley, Southwestern Alaska, Caleb H. Thompson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The lower Naknek River in southwestern Alaska dissects thick (~20m) exposures of Pleistocene glaciogenic sediments. The stratigraphy of the deposits and their physical, geochemical, mineralogical, and geochronological properties were studies to determine the number and timing of glacial advances represented. Multivariate data reduction methods (cluster and principal component analyses) were applied to the data to differentiate diamicton beds. The results show a clear separation of drift of the lower Naknek River valley from drift of northern Bristol Bay and from younger, moraine-comprising drift up valley. Within the Naknek River valley, however, there is no stratigraphic trend to the clusterings. The …

Aminostratigraphy Of Thatcher Basin, Se Idaho: Reassessment Of Pleistocene Lakes, Amy Hochberg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Quaternary geologic history of Lake Thatcher, southeastern Idaho, is pivotal in determining when the Bear River carved its through-flowing channel into the Bonneville Basin. Bright's reconstruction of the history of Lake Thatcher was based on ¹⁴C dates that are now known to be inaccurate. Lava Creek B ash found interbedded with lacustrine sediment suggests that Thatcher Basin contained a lake well before Bright's original estimate of 34 ka.

D/L ratios, which measure the extent of racemization in fossil gastropods, in conjunction with paleosols and tephra, were used to correlate between four localities across Thatcher Basin to reassess lake-level …

Habitat Selection And Movement Of A Stream-Resident Salmonid In A Regulated River And Tests Of Four Bioenergetic Optimization Models, Mark D. Bowen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A bioenergetics model was constructed for stream-resident drift-feeding salmonids. Model predictions of surplus power (energy available per unit time for growth and reproduction) were not statistically distinguishable from observations of surplus power in three laboratory studies. Of 40 experimental trials in these three studies, the model correctly predicted surplus power in 39 cases (p < 0.05).

I collected observations of rainbow trout (Oncorhynchus mykiss) focal velocity and physical habitat availability in the Green River of northeastern Utah, USA (1988-1990). In the winter of 1988, Flaming Gorge Dam generated hydropower and delivered an lJDStable discharge regime with a higher mean discharge …

The Effect Of Salinity Level Upon The Yield, Root Growth, And Water Extraction Of Contrasting Rooting Subpopulations Of Alfalfa (Medicago Sativa) Under Conditions Of Zero Leaching, Laura A. Vincent

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A major problem in irrigated agriculture in the Western U.S. is the gradual accumulation of salinity in the plant root zone. These nonuniformly saline soils contain increasing amounts of salinity with depth, and salt accumulation is accelerated in situations where leaching is minimized. Root growth and thus plant yield is limited in these soils due to decreased water uptake. We studied the root growth of two subpopulations of alfalfa differing in their ability to produce fibrous roots to determine if altering root morphology would increase plant yield and water extraction, in an irrigated saline soil.

Soil profiles for a control …

Mule Deer Highway Mortality In Northeastern Utah: An Analysis Of Population-Level Impacts And A New Mitigative System, Mark E. Lehnert

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rerouting highways to accommodate construction of the Jordanelle Reservoir in northeastern Utah caused a dramatic increase in vehicle collisions with mule deer (Odocoileus hemionus). I evaluated the effectiveness of a new system of highway crosswalk structures installed to reduce deer losses and preserve seasonal migrations. In addition, I constructed computer simulation models to investigate how highway mortality has impacted the Jordanelle deer population.

The crosswalk system restricted deer crossings to specific, well-marked areas along highways where motorists could anticipate them. Subsequent to installation, mortality declined 42.3% and 36.8% along a four-lane and two-lane highway, respectively. I was unable …

An Ecological History Of Tintic Valley, Juab County, Utah, Jeffrey A. Creque

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This work was a case study of historical ecological change in Tintic Valley, Juab County, Utah, an area historically impacted by mining and ranching activities common to much of the American West. The temporal framework for the study was approximately 120 years, the period of direct Euroamerican influence. In recognition of the ecological implications of cultural change, however, the impacts of prehistoric and protohistoric human activity on study area landscape patterns and processes were also explicitly addressed.

The study included a narrative description of historic land uses and ecological change in Tintic Valley, and examined the changes in landscape patterns …

An Instrument For Experimental Secondary Electron Emission Investigations, With Application To The Spacecraft Charging Problem, Robert Davies

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Secondary electron emission (SEE) and incident-particle backscattering are important processes accompanying the impact of energetic electrons and ions on surfaces. The phenomena play a key role in the buildup of electrical charge on spacecraft surfaces. and are therefore of particular interest to scientists attempting to model spacecraft charging. In response to a demonstrated need for data, techniques for determining total secondary electron (SE) and backscatter (BS) yields S and n, and associated scattering-angle-resolved, scattering-energy-resolved, and simultaneous angle-energy-resolved yields have been developed. Further, an apparatus capable of making the necessary measurements for experimental determination of these quantities-for conducting materials in …

Livestock As Seed Disseminators For Reseeding Degraded Rangelands: The Role Of Dung In Gap Formation And Plant Establishment, Brian S. Auman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Livestock (cattle and sheep) were examined as seed disseminators for reseeding degraded Intermountain rangelands. "Hycrest" crested wheatgrass [Agropyron desertorum (Fisch. ex Link) Schult. X A. cristatum (L.) Gaert.] seed was fed to yearling Holstein steers and Suffolk ewes. Dung was collected from each animal type and deposited on plots of high and low densities of an annual [cheatgrass (Bromus tectorum L.)] and perennial [squirreltail (Sitanion hystrix Nutt.)] grass species. The experiment evaluated the ability of the dung to suppress the resident vegetation, and the recruitment and establishment of Hycrest seedlings emerging from the dung.

Sheep dung had …

Geršgorin And Beyond•••, Jason Knight Belnap

Undergraduate Honors Capstone Projects

Eigenvalues are useful in various areas of mathematics, such as in testing the critical values of a multi variable function to see if it is a local extrema. One of the more common ways to define eigenvalues is:

Definition (1): Given that A is an n by n matrix, λ is an eigenvalue of A if and only if det(A - λI_n) = 0. Any nonzero vector in Null(A - λI) is called an eigenvector associated with λ.

A Study Of On-Line Analysis Of Hydrogen Chloride Evolution During Coal Combustion, Jennifer Humble

Masters Theses & Specialist Projects

This study involved the use of a thermogravimetric analyzer (TG) interfaced with a fourier transform infrared spectrometer (FTIR) and a mass spectrometer (MS) to determine the evolution of hydrogen chloride from coal during combustion as a function of the chlorine content and mesh size of the coal. It was determined that combined TG-FTIR and TG-MS systems offer the user an efficient means to investigate the mechanism of hydrogen chloride evolution from coal combustion. From the HC1 evolution profiles, it was determined that a good correlation exists between the chlorine content in the coal and the total amount of HC1 evolved. …