Physical Sciences and Mathematics | Open Access Articles

ศูนย์ภูมิรักษ์ธรรมชาติ

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การจัดการทรัพยากรน้ำในอ่างเก็บน้ำลำตะคอง กับการพัฒนาเมืองนครราชสีมา, เสาวนีย์ วิจิตรโกสุม

Thai Environment

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งานพยาบาลกับการลดขยะติดเชื้อ

Thai Environment

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ระบบบำบัดน้ำเสียสำเร็จรูปกับการเลือกใช้, นุชนาถ แช่มช้อย

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ภาวะโลกร้อน : มหันตภัยร้ายจากโลกยุคอุตสาหกรรม, มนนภา เทพสุด

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น้ำหอมสร้างความเสี่ยงในสุขภาพ, มณีรัตน์ องค์วรรณดี

Thai Environment

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Lower Confidence Bounds For System Reliability From Binary Failure Data Using Bootstrapping, Lawrence Leemis

Arts & Sciences Book Chapters

We consider the problem of determining a (1 – A) 100% lower confidence bound on the system reliability for a coherent system of k components using the failure data (yi, ni), where yi is the number of components of type i that pass the test and ni is the number of components of type i on test, i1, 2, …, k. We assume throughout that the components fail independently, e.g. no common-cause failures. The outline of the article is as follows. We begin with the case of a single (k1) component system where n components are placed on a test …

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Imaging-Based Parametric Resonance In An Optical Dipole-Atom Trap, S. Balik, A. L. Win, M. D. Havey

Physics Faculty Publications

We report sensitive detection of parametric resonances in a high-density sample of ultracold ⁸⁷Rb atoms confined to a far-off-resonance optical dipole trap. Fluorescence imaging of the expanded ultracold atom cloud after a period of parametric excitation shows significant modification of the atomic spatial distribution and has high sensitivity compared with traditional measurements of parametrically driven trap loss. Using this approach, a significant shift of the parametric resonance frequency is observed and attributed to the anharmonic shape of the dipole trap potential. 2009 The American Physical Society.

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Energy And System Size Dependence Of Φ Meson Production In Cu + Cu And Au + Au Collisions, B. I. Abelev, M. M. Aggarwal, Z. Ahammed, B. D. Anderson, D. Arkhipkin, G. S. Averichev, Y. Bai, J. Balewski, O. Barannikova, L. S. Barnby, S. Bültmann

Physics Faculty Publications

We study the beam-energy and system-size dependence of ϕ meson production (using the hadronic decay mode ϕ → K⁺ K⁻ ) by comparing the new results from Cu + Cu collisions and previously reported Au + Au collisions at √^sNN = 62.4 and 200 GeV measured in the STAR experiment at RHIC. Data presented in this Letter are from mid-rapidity ( | y | < 0.5 ) for 0.4 < PT < 5 GeV /c . At a given beam energy, the transverse momentum distributions for ϕ mesons are observed to be similar in yield and shape for Cu + Cu and Au + …

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New Compact Tem-Type Deflecting And Crabbing Rf Structure, J. R. Delayen, H. Wang

Physics Faculty Publications

A new type of rf structure for the deflection and crabbing of particle beams is presented. The structure is comprised of a number of parallel TEM resonant lines operating in opposing phase from each other. One of its advantages is its compactness compared to conventional crabbing cavities operating in the TM₁₁₀ mode, thus allowing low frequency designs. This geometry would also be effective for the deflection of beams propagating at velocities substantially less than that of light.

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Moments Of The Spin Structure Functions G(1)(P) And G(1)(D) For 0.05 < Q2 < 3.0 Gev2, Clas Collaboration, Y. Prok, K. V. Dharmawardane, G. E. Dodge, S. E. Kuhn, M. J. Amaryan, H. Bagdasaryan, M. Bektasoglu, S. Bültmann, S. L. Careccia, G. Gavalian, N. Guler, C. E. Hyde-Wright, H. G. Juengst, N. Kalantarians, A. Klein, J. Lachniet, R. A. Niyazov, L. M. Qin, S. Sabatie, S. Tkachenko, L. B. Weinstein, J. Zhang

Physics Faculty Publications

The spin structure functions g1 for the proton and the deuteron have been measured over a wide kinematic range in x and Q² using 1.6 and 5.7 GeV longitudinally polarized electrons incident upon polarized NH3 and ND3 targets at Jefferson Lab. Scattered electrons were detected in the CEBAF Large Acceptance Spectrometer, for 0.05 < Q² < 5GeV² and W < 3 GeV. The first moments of g1 for the proton and deuteron are presented – both have a negative slope at low Q², as predicted by the extended Gerasimov–Drell–Hearn sum rule. The first extraction of the generalized forward spin polarizability of the proton γ p 0 the Q² evolution of the first moment of g1 shows agreement in leading order with Heavy …

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Virtual Compton Scattering And Neutral Pion Electroproduction In The Resonance Region Up To The Deep Inelastic Region At Backward Angles, G. Laveissiere, N. Degrande, S. Jaminion, C. Jutier, L. Todor, G. E. Dodge, C. E. Hyde, K. Mccormick, P. E. Ulmer, L. B. Weinstein, Jefferson Lab Hall A Collaboration

Physics Faculty Publications

We have made the first measurements of the virtual Compton scattering (VCS) process via the H(e, e′p)γ exclusive reaction in the nucleon resonance region, at backward angles. Results are presented for the W-dependence at fixed Q²=1 GeV² and for the Q² dependence at fixed W near 1.5 GeV. The VCS data show resonant structures in the first and second resonance regions. The observed Q² dependence is smooth. The measured ratio of H(e, e′p)γ to H(e, e′p)π⁰ cross sections emphasizes the different sensitivity of these two reactions to the various nucleon resonances. Finally, when compared …

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Measurement Of Semi-Inclusive Π+ Electroproduction Off The Proton, Clas Collaboration, M. J. Amaryan, H. Bagdasaryan, M. Bektasoglu, S. Bültmann, K. V. Dharmawardane, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, A. Klein, A. V. Klimenko, S. E. Kuhn, M. R. Niroula, L. M. Qin, L. B. Weinstein, J. Zhang

Physics Faculty Publications

Semi-inclusive π+ electroproduction on protons has been measured with the CLAS detector at Jefferson Lab. The measurement was performed on a liquid-hydrogen target using a 5.75 GeV electron beam. The complete five-fold differential cross sections were measured over a wide kinematic range including the complete range of azimuthal angles between hadronic and leptonic planes, ϕ , enabling us to separate the ϕ-dependent terms. Our measurements of the ϕ -independent term of the cross section at low Bjorken x were found to be in fairly good agreement with pQCD calculations. Indeed, the conventional current fragmentation calculation can account for almost all …

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Photodisintegration Of 4He Into P+T, Clas Collaboration, M. J. Amaryan, S. L. Careccia, G. E. Dodge, C. E. Hyde, S. E. Kuhn, M. Mayer, C. S. Nepali, M. R. Niroula, H. Seraydaryan, S. Tkachenko, L.B. Weinstein, J. Zhang

Physics Faculty Publications

The two-body photodisintegration of 4He into a proton and a triton has been studied using the CEBAF Large-Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. Real photons produced with the Hall-B bremsstrahlung-tagging system in the energy range from 0.35 to 1.55 GeV were incident on a liquid ⁴He target. This is the first measurement of the photodisintegration of ⁴He above 0.4 GeV. The differential cross sections for the γ ⁴He →pt reaction were measured as a function of photon-beam energy and proton-scattering angle and are compared with the latest model calculations by J.-M. Laget. At …

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Electroexcitation Of Nucleon Resonances From Clas Data On Single Pion Electroproduction, Clas Collaboration, K. P. Adhikari, S. L. Careccia, T. A. Forest, C. E. Hyde, A. Klein, S. E. Kuhn, M. Mayer, C. S. Nepali, M. R. Niroula, H. Seraydaryan

Physics Faculty Publications

We present results on the electroexcitation of the low mass resonances Δ(1232)P₃₃ , N(1440)P₁₁ , N(1520)D₁₃ , and N(1535)S₁₁ in a wide range of Q². The results were obtained in the comprehensive analysis of data from the Continuous Electron Beam Accelerator Facility (CEBAF) large acceptance spectrometer (CLAS) detector at the Thomas Jefferson National Accelerator Facility (JLab) on differential cross sections, longitudinally polarized beam asymmetries, and longitudinal target and beam-target asymmetries for π electroproduction off the proton. The data were analyzed using two conceptually different approaches—fixed-t dispersion relations and a unitary isobar model—allowing us to …

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Precise Measurement Of The Neutron Magnetic Form Factor Gnm In The Few-Gev² Region, Clas Collaboration, J. Lachniet, H. Bagdasaryan, S. Bültmann, N. Kalantarians, G. E. Dodge, T. A. Forest, G. Gavalian, C. E. Hyde-Wright, A. Klien, S. E. Kuhn, M. R. Niroula, R. A. Niyazov, L. M. Qin, L. B. Weinstein, J. Zhang

Physics Faculty Publications

The neutron elastic magnetic form factor was extracted from quasielastic electron scattering on deuterium over the range Q²= 1.0–4.8 GeV² with the CLAS detector at Jefferson Lab. High precision was achieved with a ratio technique and a simultaneous in situ calibration of the neutron detection efficiency. Neutrons were detected with electromagnetic calorimeters and time-of-flight scintillators at two beam energies. The dipole parametrization gives a good description of the data

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Measurement Of Direct Fₒ(980) Photoproduction On The Proton, K. P. Adhikari, H. Bagdasaryan, S. Bültmann, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, N. Kalantarians, A. Klein, A.V. Klimenko, S. E. Kuhn, J. Lanchiet, M. R. Niroula, J. Zhang

Physics Faculty Publications

We report on the results of the first measurement of exclusive f₀(980) meson photoproduction on protons for E_γ= 3.0–3.8 GeV and −t = 0.4–1.0 GeV² . Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. The resonance was detected via its decay in the π⁺π⁻ channel by performing a partial wave analysis of the reaction γp→pπ⁺π⁻ . Clear evidence of the f₀(980) meson was found in the interference between P and S waves at M _π+π− ∼1 GeV. The S -wave differential …

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Electroproduction Of P Π⁺Π⁻ Off Protons At 0.2 < Q² < 0.6 Gev² And 1.3 < W < 1.57 Gev With The Clas Detector, M. J. Amaryan, H. Baghdasaryan, M. Bektasoglu, S. Bültmann, S. L. Careccia, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde, W. Kim, A. Klein, F. J. Klein, A. Klimenko, S. E. Kuhn, S. Tkachenko, L. B. Weinstein, Et Al., Clas Collaboration

Physics Faculty Publications

This paper reports on the most comprehensive data set obtained on differential and fully integrated cross sections for the process ep → e'pπ⁺π^-. The data were collected with the CLAS detector at Jefferson Laboratory. Measurements were carried out in the as yet unexplored kinematic region of photon virtuality 0.2 < Q² < 0.6 GeV² and invariant mass of the final hadron system W from 1.3 to 1.57 GeV. For the first time, nine independent one-fold differential cross sections were determined in each bin of W and Q² covered by the measurements. A phenomenological analysis of the data allowed …

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An Inventory And Condition Survey Of The Lower Murchison River Area, Western Australia, P Hennig

Technical Bulletins

The inventory and condition survey of the lower Murchison River area, undertaken by the Department of Agriculture and Food, Western Australia (DAFWA) between 2002 and 2003, describes and maps the natural resources of the region’s pastoral leasehold land. This survey report provides a baseline record of the existence and condition of the natural area’s resources, to assist with the planning and implementation of land management practices. The report identified and described the condition of soils, landforms, vegetation, habitat, ecosystems, and declared plants and animals. It also assessed the impact of pastoralism and made land management recommendations. This survey report presents …

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Design Optimization Of Superconducting Parallel-Bar Cavities, Subashini De Silva, Jean R. Delayen

Physics Faculty Publications

The parallel-bar structure is a new superconducting geometry whose features and properties may have significant advantages over conventional superconducting deflecting and crabbing cavities for a number of applications. Jefferson Lab is in need for a 499 MHz, 11 GeV rf separator as part of its 12 GeV upgrade program. We report on design optimization studies performed todate for this and other applications.

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A New Tem-Type Deflecting And Crabbing Rf Structure, Jean R. Delayen, H. Wang

Physics Faculty Publications

A new type of rf structure for the deflection and crabbing of particle bunches is introduced. It is comprised of a number of parallel TEM-resonant lines operating in opposite phase from each other. One of its main advantages is its compactness compared to conventional crabbing cavities operating in the TM110 mode, thus allowing low frequency designs. The properties and characteristics of this type of structure are presented.

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Theoretical Study Of Electronic Properties Of The Cu(001) Surface Under Conditions Of High Coverage Oxidation, Willie Burton Maddox

Physics Theses

The study of adsorption of oxygen on transition metal surface is important for the understanding of oxidation, heterogeneous catalysis, and metal corrosion. The structures formed on oxidized transition metal surfaces vary from simple adlayers of chemisorbed oxygen to more complex structures which result from the diffusion of oxygen into sub-surface regions. In this thesis, an textit{ab-initio} investigation of stability and associated physical and electronic properties of different adsorption phases of oxygen on Cu(001) as well as of the clean Cu surfaces using density functional theory in the generalized gradient approximation, is presented. All surface geometries are fully optimized. Results of …

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Development And Characterization Of Gas Electron Multiplier Chambers For A Digital Hadron Calorimeter In The International Linear Collider, Jacob Russell Smith

Physics Theses

Gas Electron Multiplier, or GEM, technology provides an attractive option for high precision jet energy measurements for future high energy physics experiments at the International Linear Collider. High voltage settings and gas mixture ratios are determined to optimize double GEM chamber gain and efficiency performance. Electronics readout using QPAO2 chipset and the analog KPIX system developed by Stanford Linear Accelerator Center are used at different stages of the development and characterization of double GEM chambers. The results presented in this thesis are performed primarily at UTA using radioactive sources and cosmic ray particles but also include results from test beam …

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Cellulosic Ethanol Production In The United States: Conversion Technologies, Current Production Status, Economics, And Emerging Developments, Puneet Dwivedi, Janaki R.R. Alavalapati, Pankaj Lal

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Details of existing conversion technologies for cellulosic ethanol production, both hydrolysis and thermochemical, have been discussed along with their present adoption status. Furthermore, economics of ethanol production by using different conversion technologies has been discussed. Emerging conversion technologies and other developments which might affect the cellulosic ethanol production are also characterized. Based on current estimates, it was found that about 400 million gallons of cellulosic ethanol will be produced in the country in coming years using different conversion technologies. It was noticed that out of several available conversion technologies, thermochemical-based technologies are gaining popularity and it is projected that the …

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Arecibo Pulsar Survey Using Alpha: Probing Radio Pulsar Intermittency And Transients, J. S. Deneva, J. M. Cordes, M. A. Mclaughlin, D. J. Nice, D. R. Lorimer, F. Crawford, N. D.R. Bhat, F. Camilo, D. J. Champion, P. C.C. Freire, S. Edel, V. I. Kondratiev, J. W.T. Hessels, F. A. Jenet, L. Kasian, V. M. Kaspi, M. Kramer, P. Lazarus, S. M. Ransom, I. H. Stairs, B. W. Stappers, J. Van Leeuwen, A. Brazier, A. Venkataraman, J. A. Zollweg, S. Bogdanov

Physics and Astronomy Faculty Publications and Presentations

We present radio transient search algorithms, results, and statistics from the ongoing Arecibo Pulsar ALFA (PALFA) survey of the Galactic plane. We have discovered seven objects through a search for isolated dispersed pulses. All of these objects are Galactic and have measured periods between 0.4 and 4.7 s. One of the new discoveries has a duty cycle of 0.01%, smaller than that of any other radio pulsar. We discuss the impact of selection effects on the detectability and classification of intermittent sources, and compare the efficiencies of periodicity and single-pulse (SP) searches for various pulsar classes. For some cases we …

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Strong Field Effects On Pulsar Arrival Times: Circular Orbits And Equatorial Beams, Yan Wang, F. A. Jenet, Teviet Creighton, Richard H. Price

Physics and Astronomy Faculty Publications and Presentations

If a pulsar orbits a supermassive black hole, the timing of pulses that pass close to the hole will show a variety of strong field effects. To compute the intensity and timing of pulses that have passed close to a nonrotating black hole, we introduce here a simple formalism based on two \"universal functions,\" one for the bending of photon trajectories and the other for the photon travel time on these trajectories. We apply this simple formalism to the case of a pulsar in circular orbit that beams its pulses into the orbital plane. In addition to the \"primary\" pulses …

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Case Study: Implementing Tools For Software Quality Assurance, James Brennan

Regis University Student Publications (comprehensive collection)

Test tools have become ubiquitous in the practice of Software Quality Assurance. Every year, many millions of dollars are spent on specialized software to help manage requirements, test cases, or defects—or to automate test execution. But, after purchasing the software, many companies fail to successfully implement the tools. Given the cost of most test software, it’s not surprising that companies often make a second attempt at using the tools. This thesis describes a second-chance effort to use a suite of tools to manage various aspects of the test process. It examines some of the goals driving the adoption of test …

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Open Source Trouble Ticket System, Steve Chapman

Regis University Student Publications (comprehensive collection)

The productivity of many organizations in the IT industry suffer greatly because most have yet to implement a process to manage and track IT issues from the time a problem is reported by the enduser to the time in which the problem is resolved. Until such a process exists, many organizations will find themselves unable to effectively manage time and resources thus resulting in unnecessary downtime, decrease in productivity and ultimately becoming an organization who "throw money at the problem" instead of fixing the root cause. One such solution would be to use a trouble ticket system application. There are …

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Interaction Of Tollmien-Schlichting Waves In The Air With The Sea Surface, Shahrdad G. Sajjadi, Harihar Khanal

Publications

No abstract provided.

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A Plotless Density Estimator Based On The Asymptotic Limit Of Ordered Distance Estimation Values, Barry J. Kronenfeld

Barry J. Kronenfeld

Estimation of tree density from point-tree distances is an attractive option for quick inventory of new sites, but estimators that are unbiased in clustered and dispersed situations have not been found. Noting that bias of an estimator derived from distances to the kth nearest neighbor from a random point tends to decrease with increasing k, a method is proposed for estimating the limit of an asymptotic function through a set of ordered distance estimators. A standard asymptotic model is derived from the limiting case of a clustered distribution. The proposed estimator is evaluated against 13 types of simulated generating processes, …

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Full-Text Articles in Physical Sciences and Mathematics

ศูนย์ภูมิรักษ์ธรรมชาติ

Thai Environment

การจัดการทรัพยากรน้ำในอ่างเก็บน้ำลำตะคอง กับการพัฒนาเมืองนครราชสีมา, เสาวนีย์ วิจิตรโกสุม

Thai Environment

งานพยาบาลกับการลดขยะติดเชื้อ

Thai Environment

ระบบบำบัดน้ำเสียสำเร็จรูปกับการเลือกใช้, นุชนาถ แช่มช้อย

Thai Environment

ภาวะโลกร้อน : มหันตภัยร้ายจากโลกยุคอุตสาหกรรม, มนนภา เทพสุด

Thai Environment

น้ำหอมสร้างความเสี่ยงในสุขภาพ, มณีรัตน์ องค์วรรณดี

Thai Environment

Lower Confidence Bounds For System Reliability From Binary Failure Data Using Bootstrapping, Lawrence Leemis

Arts & Sciences Book Chapters

Imaging-Based Parametric Resonance In An Optical Dipole-Atom Trap, S. Balik, A. L. Win, M. D. Havey

Physics Faculty Publications

Energy And System Size Dependence Of Φ Meson Production In Cu + Cu And Au + Au Collisions, B. I. Abelev, M. M. Aggarwal, Z. Ahammed, B. D. Anderson, D. Arkhipkin, G. S. Averichev, Y. Bai, J. Balewski, O. Barannikova, L. S. Barnby, S. Bültmann

Physics Faculty Publications

New Compact Tem-Type Deflecting And Crabbing Rf Structure, J. R. Delayen, H. Wang

Physics Faculty Publications

Physics Faculty Publications

Physics Faculty Publications

Physics Faculty Publications

Photodisintegration Of 4He Into P+T, Clas Collaboration, M. J. Amaryan, S. L. Careccia, G. E. Dodge, C. E. Hyde, S. E. Kuhn, M. Mayer, C. S. Nepali, M. R. Niroula, H. Seraydaryan, S. Tkachenko, L.B. Weinstein, J. Zhang

Physics Faculty Publications

Electroexcitation Of Nucleon Resonances From Clas Data On Single Pion Electroproduction, Clas Collaboration, K. P. Adhikari, S. L. Careccia, T. A. Forest, C. E. Hyde, A. Klein, S. E. Kuhn, M. Mayer, C. S. Nepali, M. R. Niroula, H. Seraydaryan

Physics Faculty Publications

Physics Faculty Publications

Measurement Of Direct Fₒ(980) Photoproduction On The Proton, K. P. Adhikari, H. Bagdasaryan, S. Bültmann, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, N. Kalantarians, A. Klein, A.V. Klimenko, S. E. Kuhn, J. Lanchiet, M. R. Niroula, J. Zhang

Physics Faculty Publications

Physics Faculty Publications

An Inventory And Condition Survey Of The Lower Murchison River Area, Western Australia, P Hennig

Technical Bulletins

Design Optimization Of Superconducting Parallel-Bar Cavities, Subashini De Silva, Jean R. Delayen

Physics Faculty Publications

A New Tem-Type Deflecting And Crabbing Rf Structure, Jean R. Delayen, H. Wang

Physics Faculty Publications

Theoretical Study Of Electronic Properties Of The Cu(001) Surface Under Conditions Of High Coverage Oxidation, Willie Burton Maddox

Physics Theses

Development And Characterization Of Gas Electron Multiplier Chambers For A Digital Hadron Calorimeter In The International Linear Collider, Jacob Russell Smith

Physics Theses

Cellulosic Ethanol Production In The United States: Conversion Technologies, Current Production Status, Economics, And Emerging Developments, Puneet Dwivedi, Janaki R.R. Alavalapati, Pankaj Lal

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Physics and Astronomy Faculty Publications and Presentations

Strong Field Effects On Pulsar Arrival Times: Circular Orbits And Equatorial Beams, Yan Wang, F. A. Jenet, Teviet Creighton, Richard H. Price

Physics and Astronomy Faculty Publications and Presentations

Case Study: Implementing Tools For Software Quality Assurance, James Brennan

Regis University Student Publications (comprehensive collection)

Open Source Trouble Ticket System, Steve Chapman

Regis University Student Publications (comprehensive collection)

Interaction Of Tollmien-Schlichting Waves In The Air With The Sea Surface, Shahrdad G. Sajjadi, Harihar Khanal

Publications

A Plotless Density Estimator Based On The Asymptotic Limit Of Ordered Distance Estimation Values, Barry J. Kronenfeld

Barry J. Kronenfeld