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2009

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Articles 1981 - 2010 of 7616

Full-Text Articles in Physical Sciences and Mathematics

Fires And Their Implications For Acidic Peatlands, Northeastern Nsw, Jeffrey Parr, Kathryn Taffs, Geoffrey Kerr, J Arthur Jul 2009

Fires And Their Implications For Acidic Peatlands, Northeastern Nsw, Jeffrey Parr, Kathryn Taffs, Geoffrey Kerr, J Arthur

Jeffrey Parr

No abstract provided.


Interactions Between Human Activity, Volcanic Eruptions And Vegetation During The Holocene At Garua And Numundo, West New Britain, Png, William Boyd, Carol Lentfer, Jeffrey Parr Jul 2009

Interactions Between Human Activity, Volcanic Eruptions And Vegetation During The Holocene At Garua And Numundo, West New Britain, Png, William Boyd, Carol Lentfer, Jeffrey Parr

Jeffrey Parr

This paper reviews recent fossil phytolith analysis from wet tropical West New Britain (Papua New Guinea). The Holocene vegetation has been influenced by spatially and temporally diverse patterns of both prehistoric human settlement and catastrophic volcanic events. We have hypothesized different landscape responses and recovery pathways to events during the last six millennia. Phytolith sequences on the coastal lowlands, the Willaumez Peninsula, and nearby island of Garua provide details of vegetational change and human interactions at different landscape scales since c. 5900 cal yr B.P. During this period four major volcanic eruptions (c. 5900, 3600, 1700 and 1400 cal yr …


Chronology And Palaeoecology Of An Acidic Wetland Peat In Northeastern Nsw, Kathryn Taffs, Jeffrey Parr, Keith Bolton Jul 2009

Chronology And Palaeoecology Of An Acidic Wetland Peat In Northeastern Nsw, Kathryn Taffs, Jeffrey Parr, Keith Bolton

Jeffrey Parr

No abstract provided.


Reconstructing Fire Histories: Methods, Interpretation And Common On-Ground Across Fire History Research In Australia, Jeffrey Parr, Geoffrey Kerr, J Arthur, Keith Bolton, Geraldine Jacobsen, Kathryn Taffs Jul 2009

Reconstructing Fire Histories: Methods, Interpretation And Common On-Ground Across Fire History Research In Australia, Jeffrey Parr, Geoffrey Kerr, J Arthur, Keith Bolton, Geraldine Jacobsen, Kathryn Taffs

Jeffrey Parr

No abstract provided.


Response To Cotter And Cotter: Confirming The Probable Industrial Origin Of Archaeological Daub At An Iron Age Site In Northeast Thailand, William Boyd, Jeffrey Parr Jul 2009

Response To Cotter And Cotter: Confirming The Probable Industrial Origin Of Archaeological Daub At An Iron Age Site In Northeast Thailand, William Boyd, Jeffrey Parr

Jeffrey Parr

No abstract provided.


Fires Impact On An Acidic Peatland In Northeastern Nsw: Implications For The Interpretation Of Fire Histories, Pyrite Formation And Loss Of Organic Carbon, Jeffrey Parr, Geoffrey Kerr, J Arthur, Kathryn Taffs Jul 2009

Fires Impact On An Acidic Peatland In Northeastern Nsw: Implications For The Interpretation Of Fire Histories, Pyrite Formation And Loss Of Organic Carbon, Jeffrey Parr, Geoffrey Kerr, J Arthur, Kathryn Taffs

Jeffrey Parr

No abstract provided.


West Byron Wetland Vegetation History Report., Jeffrey Parr, Kathryn Taffs Jul 2009

West Byron Wetland Vegetation History Report., Jeffrey Parr, Kathryn Taffs

Jeffrey Parr

No abstract provided.


Comet C/2004 Q2 (Machholz): Parent Volatiles, A Search For Deuterated Methane, And Constraint On The Ch4 Spin Temperature, Boncho P. Bonev, Michael J. Mumma, Erika L. Gibb, Michael A. Disanti, Geronimo L. Villanueva, Karen Magee-Sauer, Richard S. Ellis Jul 2009

Comet C/2004 Q2 (Machholz): Parent Volatiles, A Search For Deuterated Methane, And Constraint On The Ch4 Spin Temperature, Boncho P. Bonev, Michael J. Mumma, Erika L. Gibb, Michael A. Disanti, Geronimo L. Villanueva, Karen Magee-Sauer, Richard S. Ellis

Erika Gibb

High-dispersion (λ/δλ ≈ 25,000) infrared spectra of Comet C/2004 Q2 (Machholz) were acquired on 2004 November 28-29, and 2005 January 19 (UT dates) with the Near InfraRed echelle SPECtrograph (NIRSPEC) at the Keck-2 telescope on Mauna Kea. We detected H2O, CH4, C2H2, C2H6, CO, H2CO, CH3OH, HCN, and NH3 and we conducted a sensitive search for CH3D. We report rotational temperatures, production rates, and mixing ratios (with respect to H2O) at heliocentric distances of 1.49 AU (2004 November) and 1.21 AU (2005 January). We highlight three principal results. (1) The mixing ratios of parent volatiles measured at 1.49 AU and …


Moment Release Rate Of Cascadia Tremor Constrained By Gps, Ana C. Aguiar, Timothy I. Melbourne, Craig W. Scrivner Jul 2009

Moment Release Rate Of Cascadia Tremor Constrained By Gps, Ana C. Aguiar, Timothy I. Melbourne, Craig W. Scrivner

All Faculty Scholarship for the College of the Sciences

A comparison of GPS and seismic analyses of 23 distinct episodic tremor and slip events, located throughout the Cascadia subduction zone over an 11-year period, yields a highly linear relationship between moment release, as estimated from GPS, and total duration of nonvolcanic tremor, as summed from regional seismic arrays. The events last 1–5 weeks, typically produce ~5 mm of static forearc deformation, and show cumulative totals of tremor that range from 40 to 280 h. Moment released by each event is estimated by inverting GPS-measured deformation, which is sensitive to all rates of tremor-synchronous faulting, including aseismic creep, for total …


Development Of Scoring Rubrics And Pre-Service Teachers Ability To Validate Mathematical Proofs, Timothy J. Middleton Jul 2009

Development Of Scoring Rubrics And Pre-Service Teachers Ability To Validate Mathematical Proofs, Timothy J. Middleton

Mathematics & Statistics ETDs

The basic aim of this exploratory research study was to determine if a specific instructional strategy, that of developing scoring rubrics within a collaborative classroom setting, could be used to improve pre-service teachers facility with proofs. During the study, which occurred in a course for secondary mathematics teachers, the primary focus was on creating and implementing a scoring rubric, rather than on direct instruction about proofs. In general, the study had very mixed results. Statistically, the quantitative data indicated no significant improvement occurred in participants' ability to validate proofs. However, the qualitative results and the considerable improvement by some participants …


Relaxation Of Vibrationally Excited Trifluorobenzene And Tetrafluorobenzene By Collisions With Carbon Dioxide, Alan M. Johnson Jul 2009

Relaxation Of Vibrationally Excited Trifluorobenzene And Tetrafluorobenzene By Collisions With Carbon Dioxide, Alan M. Johnson

Theses and Dissertations

An investigation into the relaxation of highly vibrationally excited trifluorobenzene and tetrafluorobenzene following collisions with carbon dioxide was performed using diode laser transient absorption spectroscopy. A 248 nm excimer laser prepared the vibrationally hot (E'~41,000 cm-1) fluorobenzene molecules. Large amounts of translational and rotational energy are transferred through collisions between the hot donor molecule and CO2. Rate constants and collisional probabilities were calculated by probing the high J states (J=58~80) of CO2 in the vibrational ground state, 0000, with measurements taken 1 µsec, ¼ the mean gas collision time, following each excimer laser pulse. The energy transfer probability distribution function, …


Estimating The Effect Of Disability On Medicare Expenditures, David Morris Burk Jul 2009

Estimating The Effect Of Disability On Medicare Expenditures, David Morris Burk

Theses and Dissertations

We consider the effect of disability status on Medicare expenditures. Disabled elderly historically have accounted for a significant portion of Medicare expenditures. Recent demographic trends exhibit a decline in the size of this population, causing some observers to predict declines in Medicare expenditures. There are, however, reasons to be suspicious of this rosy forecast. To better understand the effect of disability on Medicare expenditures, we develop and estimate a model using the generalized method of moments technique. We find that newly disabled elderly generally spend more than those who have been disabled for longer periods of time. Also, we find …


Ion Transport Behaviors Upstream And Downstream From The Sampling Cone Of An Inductively Coupled Plasma Mass Spectrometer, Haibin Ma Jul 2009

Ion Transport Behaviors Upstream And Downstream From The Sampling Cone Of An Inductively Coupled Plasma Mass Spectrometer, Haibin Ma

Theses and Dissertations

Inductively coupled plasma - mass spectrometry (ICP-MS) is the technique of choice worldwide for trace elemental determinations because of its excellent ionization ability, low detection limits and fast analysis speeds. However, the ICP-MS still suffers from some disadvantages, such as spectral overlap and severe matrix effects. Matrix effects or interferences, partly arise from changes in the analyte transmission through the interfacial region between the ICP and mass spectrometer with changes in sample matrix. Better understanding of the transmission behaviors of analyte through the sampling and skimmer cones will provide the insights needed to alleviate matrix interferences and to improve the …


Reactivity-Dependent Pcr: Direct, Solution-Phase In Vitro Selection For Bond Formation, David J. Gorin, Adam S. Kamlet, David R. Liu Jul 2009

Reactivity-Dependent Pcr: Direct, Solution-Phase In Vitro Selection For Bond Formation, David J. Gorin, Adam S. Kamlet, David R. Liu

Chemistry: Faculty Publications

(Figure Presented) In vitro selection is a key component of efforts to discover functional nucleic acids and small molecules from libraries of DNA, RNA, and DNA-encoded small molecules. Such selections have been widely used to evolve RNA and DNA catalysts and, more recently, to discover new reactions from DNA-encoded libraries of potential substrates. While effective, current strategies for selections of bond-forming and bond-cleaving reactivity are generally indirect, require the synthesis of biotin-linked substrates, and involve multiple solution-phase and solid-phase manipulations. In this work we report the successful development and validation of reactivity-dependent PCR (RDPCR), a new method that more directly …


The Role Of Smpb In The Early Stages Of Trans-Translation, Deanna June Cazier Jul 2009

The Role Of Smpb In The Early Stages Of Trans-Translation, Deanna June Cazier

Theses and Dissertations

Ribosomes stall on defective messenger RNA transcripts in eubacteria. Without a mechanism to release stalled ribosomes, these cells would die. Transfer-messenger RNA (tmRNA) and small protein B (SmpB) reactivate stalled ribosomes in a process known as trans-translation. Together, tmRNA and SmpB mimic alanyl-tRNA, entering the A site of stalled ribosomes and accepting transfer of the stalled polypeptide. A portion of tmRNA is then positioned as a template for the ribosome to resume translating. The tmRNA open reading frame encodes a proteolysis tag to mark the aberrant polypeptide for degradation and a stop codon to release the ribosome. How are tmRNA …


Inconsistency And Incompleteness In Relational Databases And Logic Programs, Navin Viswanath Jul 2009

Inconsistency And Incompleteness In Relational Databases And Logic Programs, Navin Viswanath

Computer Science Dissertations

The aim of this thesis is to study the role played by negation in databases and to develop data models that can handle inconsistent and incomplete information. We develop models that also allow incompleteness through disjunctive information under both the CWA and the OWA in relational databases. In the area of logic programming, extended logic programs allow explicit representation of negative information. As a result, a number of extended logic programs have an inconsistent semantics. We present a translation of extended logic programs to normal logic programs that is more tolerant to inconsistencies. Extended logic programs have also been used …


Measurement Of Beauty Production From Dimuon Events At Hera, S. Chekanov, M. Derrick, S. Magill, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, F. Cindolo, M. Corradi, G. Iacobucci, A. Margotti, R. Nania, A. Polini, S. Antonelli, M. Basile, M. Bindi, L. Cifarelli, A. Contin, S. De Pasquale, G. Sartorelli, A. Zichichi, D. Bartsch, I. Brock, H. Hartmann Jul 2009

Measurement Of Beauty Production From Dimuon Events At Hera, S. Chekanov, M. Derrick, S. Magill, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, F. Cindolo, M. Corradi, G. Iacobucci, A. Margotti, R. Nania, A. Polini, S. Antonelli, M. Basile, M. Bindi, L. Cifarelli, A. Contin, S. De Pasquale, G. Sartorelli, A. Zichichi, D. Bartsch, I. Brock, H. Hartmann

Faculty Publications

Beauty production in events containing two muons in the final state has been measured with the ZEUS detector at HERA using an integrated luminosity of 114 pb-1. A low transverse-momentum threshold for muon identification, in combination with the large rapidity coverage of the ZEUS muon system, gives access to almost the full phase space for beauty production. The total cross section for beauty production in ep collisions at (s)1/2 = 318 GeV has been measured to be σtot(ep bX) = 13.9 1.5(stat.)+4.0-4.3(syst.)nb. Differential cross sections and a measurement of b correlations are also obtained, and compared to other beauty cross-section …


Some Congruence Properties Of Pell's Equation, Nathan C. Priddis Jul 2009

Some Congruence Properties Of Pell's Equation, Nathan C. Priddis

Theses and Dissertations

In this thesis I will outline the impact of Pell's equation on various branches of number theory, as well as some of the history. I will also discuss some recently discovered properties of the solutions of Pell's equation.


Zero-Inflated Censored Regression Models: An Application With Episode Of Care Data, Jonathan P. Prasad Jul 2009

Zero-Inflated Censored Regression Models: An Application With Episode Of Care Data, Jonathan P. Prasad

Theses and Dissertations

The objective of this project is to fit a sequence of increasingly complex zero-inflated censored regression models to a known data set. It is quite common to find censored count data in statistical analyses of health-related data. Modeling such data while ignoring the censoring, zero-inflation, and overdispersion often results in biased parameter estimates. This project develops various regression models that can be used to predict a count response variable that is affected by various predictor variables. The regression parameters are estimated with Bayesian analysis using a Markov chain Monte Carlo (MCMC) algorithm. The tests for model adequacy are discussed and …


Evans Function Computation, Blake H. Barker Jul 2009

Evans Function Computation, Blake H. Barker

Theses and Dissertations

In this thesis, we review the stability problem for traveling waves and discuss the Evans function, an emerging tool in the stability analysis of traveling waves. We describe some recent developments in the numerical computation of the Evans function and discuss STABLAB, an interactive MATLAB based tool box that we developed. In addition, we verify the Evans function for shock layers in Burgers equation and the p-system with and without capillarity, as well as pulses in the generalized Kortweg-de Vries (gKdV) equation. We conduct a new study of parallel shock layers in isentropic magnetohydrodynamics (MHD) obtaining results consistent with stability.


Using Rfid To Overcome Inventory Control Challenges: A Proof Of Concept, Dane Hamilton, Katina Michael, Samuel Fosso Wamba Jul 2009

Using Rfid To Overcome Inventory Control Challenges: A Proof Of Concept, Dane Hamilton, Katina Michael, Samuel Fosso Wamba

Dr Samuel Fosso Wamba

Using a Proof of Concept approach, this paper examines RFID’s impact on inventory control of a small-to-medium retailer. Results indicate that RFID technology can function effectively in a small-to-medium hardware environment. Also, the majority of the simulations recorded reasonable read rates even though the simulations were set up over a short period of time without a great deal of fine-tuning. Moreover, RFID could have a positive impact on the inventory-related processes of the organisation by either streamlining or formalizing them and facilitate the electronic storage of information captured in real-time, relating to the movement of stock and the amount of …


Using Rfid To Overcome Inventory Control Challenges: A Proof Of Concept, Dane Hamilton, Katina Michael, Samuel Fosso Wamba Jul 2009

Using Rfid To Overcome Inventory Control Challenges: A Proof Of Concept, Dane Hamilton, Katina Michael, Samuel Fosso Wamba

Professor Katina Michael

Using a Proof of Concept approach, this paper examines RFID’s impact on inventory control of a small-to-medium retailer. Results indicate that RFID technology can function effectively in a small-to-medium hardware environment. Also, the majority of the simulations recorded reasonable read rates even though the simulations were set up over a short period of time without a great deal of fine-tuning. Moreover, RFID could have a positive impact on the inventory-related processes of the organisation by either streamlining or formalizing them and facilitate the electronic storage of information captured in real-time, relating to the movement of stock and the amount of …


Mechanisms Controlling Metal And Phosphorus Dynamics In An Experimentally Acidified Watershed In Maine, Ivan J. Fernandez Jul 2009

Mechanisms Controlling Metal And Phosphorus Dynamics In An Experimentally Acidified Watershed In Maine, Ivan J. Fernandez

University of Maine Office of Research Administration: Grant Reports

The Bear Brook Watershed in Maine (BBWM) is a long-term (14+ years), whole-watershed experiment designed to study ecosystem responses to acid deposition. One watershed has been treated bimonthly by helicopter with nitrogen and sulfur since 1989. Results have documented progressive acidification of soils and streams, substantial losses of soil nutrients (e.g., calcium), increased nitrogen cycling, and changes in tree foliar chemistry. Little research has been done on phosphorus, a critical nutrient in ecosystems. This project will evaluate the effects of long-term watershed acidification on metal mobilization (focusing on aluminum and iron) and linked effects on phosphorus at BBWM by studying …


The Effect Of Correlation In False Discovery Rate Estimation, Armin Schwartzman, Xihong Lin Jul 2009

The Effect Of Correlation In False Discovery Rate Estimation, Armin Schwartzman, Xihong Lin

Harvard University Biostatistics Working Paper Series

No abstract provided.


Production Of O2 Herzberg States In The Deep Uv Photodissociation Of Ozone, Reinhard Schinke, George C. Mcbane, L. Shen, P. C. Singh, A. G. Suits Jul 2009

Production Of O2 Herzberg States In The Deep Uv Photodissociation Of Ozone, Reinhard Schinke, George C. Mcbane, L. Shen, P. C. Singh, A. G. Suits

Peer Reviewed Articles

High-resolution imaging experiments combined with new electronic structure and dynamics calculations strongly indicate that the O(3P)+O2 products with very low kinetic energy release (Etr2: A' 3Δu(v=0, 1, 2) and A 3Σ+u(v=0, 1). This interpretation contradicts the earlier assignment to very high (v≥26) vibrational states of O2(3Σ-g).


Catching Relativity Violations With Atoms, Quentin G. Bailey Jul 2009

Catching Relativity Violations With Atoms, Quentin G. Bailey

Physics & Astronomy - Prescott

A Viewpoint on: Atom interferometry tests of local Lorentz invariance in gravity and electrodynamics Keng-Yeow Chung, Sheng-wey Chiow, Sven Herrmann, Steven Chu and Holger Müller Phys. Rev. D 80, 016002 (2009) – Published July 6, 2009.


Numerical Solutions For Stochastic Differential Equations And Some Examples, Yi Luo Jul 2009

Numerical Solutions For Stochastic Differential Equations And Some Examples, Yi Luo

Theses and Dissertations

In this thesis, I will study the qualitative properties of solutions of stochastic differential equations arising in applications by using the numerical methods. It contains two parts. In the first part, I will first review some of the basic theory of the stochastic calculus and the Ito-Taylor expansion for stochastic differential equations (SDEs). Then I will discuss some numerical schemes that come from the Ito-Taylor expansion including their order of convergence. In the second part, I will use some schemes to solve the stochastic Duffing equation, the stochastic Lorenz equation, the stochastic pendulum equation, and the stochastic equations which model …


Collaborative Learning Strategies To Overcome Barriers To Science Translation In Coastal Watershed Management: A Final Report Submitted To The Noaa/Unh Cooperative Institute For Coastal And Estuarine Environmental Technology (Ciceet), Christine Baumann Feurt Jul 2009

Collaborative Learning Strategies To Overcome Barriers To Science Translation In Coastal Watershed Management: A Final Report Submitted To The Noaa/Unh Cooperative Institute For Coastal And Estuarine Environmental Technology (Ciceet), Christine Baumann Feurt

Environmental Studies Faculty Publications

An important non-point source pollution challenge facing municipal officials in southern Maine is the conversion of forested and undeveloped land to development (Krum & Feurt, 2002; Wells NERR, 2003; 2001). There is a critical need, during the next decade, to apply science-based knowledge and facilitate the adoption of practices associated with low impact development, protection of riparian buffers, preservation of wetlands and innovative stormwater management technology to land use decision-making. The science and technology that supports municipal efforts to preserve the ecological services provided by an undeveloped landscape as it is converted to what is considered economic use are the …


Properties Of The Zero Forcing Number, Kayla Denise Owens Jul 2009

Properties Of The Zero Forcing Number, Kayla Denise Owens

Theses and Dissertations

The zero forcing number is a graph parameter first introduced as a tool for solving the minimum rank problem, which is: Given a simple, undirected graph G, and a field F, let S(F,G) denote the set of all symmetric matrices A=[a_{ij}] with entries in F such that a_{ij} doess not equal 0 if and only if ij is an edge in G. Find the minimum possible rank of a matrix in S(F,G). It is known that the zero forcing number Z(G) provides an upper bound for the maximum nullity of a graph. I investigate properties of the zero forcing number, …


Computational Thinking (Ct): On Weaving It In, Paul Curzon, Joan Peckham, Harriet G. Taylor, Amber Settle, Eric Roberts Jul 2009

Computational Thinking (Ct): On Weaving It In, Paul Curzon, Joan Peckham, Harriet G. Taylor, Amber Settle, Eric Roberts

Amber Settle

Computing offers essential problem-solving tools needed for contemporary challenges. The role of computing in education, and appropriate pathways for modern students, are of concern [10]. Educators recognize the importance of improving information technology (IT) skills and fluency, and studies have developed guidelines [7][8], but the analytical concepts and tools of computing have benefits beyond IT fluency. CT [12] continues earlier discussions on the nature of computing, [3][9]. This has helped the computing community to strengthen definition of the problem solving skills that computing brings to society, through education, outreach, and research. Recently, CT has served as a basis for several …