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2009

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Articles 1711 - 1740 of 7616

Full-Text Articles in Physical Sciences and Mathematics

Complex Adaptive Systems As A Model For Evaluating Organisational Change Caused By The Introduction Of Health Information Systems, Kieren Diment Mr, Ping Yu, K. Garrety Aug 2009

Complex Adaptive Systems As A Model For Evaluating Organisational Change Caused By The Introduction Of Health Information Systems, Kieren Diment Mr, Ping Yu, K. Garrety

Faculty of Informatics - Papers (Archive)

This paper documents the preliminary development of a framework for evaluating organisational change processes during the implementation of an electronic nursing documentation system in residential aged care facilities. It starts with a brief outline of organisational change processes. This is followed by a more detailed exposition of the principles underlying complex adaptive systems (CAS) theory, where we explain how mathematical concepts can be used to illuminate qualitative research approaches. Finally we present some preliminary findings on the facilitators and barriers for the introduction of the electronic documentation system, explained with reference to the CAS theory, based on analysis of interviews …


An Integrated Crop- And Soil-Based Strategy For Variable-Rate Nitrogen Management In Corn, Darrin F. Roberts Aug 2009

An Integrated Crop- And Soil-Based Strategy For Variable-Rate Nitrogen Management In Corn, Darrin F. Roberts

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nitrogen (N) management in cereal crops has been the subject of considerable research and debate for several decades. Historic N management practices have contributed to low nitrogen use efficiency (NUE). Low NUE can be caused by such things as poor synchronization between soil N supply and crop demand, uniform application rates of fertilizer N to spatially variable landscapes, and failure to account for temporally variable influences on soil N supply and crop N need. Active canopy reflectance sensors and management zones (MZ) have been studied separately as possible plant- and soil-based N management tools to increase NUE. Recently, some have …


Nanostructured Semiconductor Heterojunctions From Quantum Dot Layers, Rolf Könenkamp, Robert Campbell Word, Athavan Nadarajah Aug 2009

Nanostructured Semiconductor Heterojunctions From Quantum Dot Layers, Rolf Könenkamp, Robert Campbell Word, Athavan Nadarajah

Physics Faculty Publications and Presentations

We report the deposition of conformal thin layers of 10?50 nm thickness from II-VI quantum dot suspensions on ZnO nanowire substrates. Smooth polycrystalline films of high electronic quality can be obtained from CdSe quantum dots after annealing at moderate temperatures. The electronic properties are adequate for detector and solar cell applications. The growth and annealing temperatures permit deposition on light-weight and flexible substrates. Some elemental diffusion of Se across the CdSe/ZnO interface occurs in the film formation. A comparison with CdS/ZnO junctions indicates that the low Se diffusion rates are essential for efficient charge transfer.


A Discrete Impulsive Model For Random Heating And Brownian Motion, John D. Ramshaw Aug 2009

A Discrete Impulsive Model For Random Heating And Brownian Motion, John D. Ramshaw

Physics Faculty Publications and Presentations

The energy of a mechanical system subjected to a random force with zero mean increases irreversibly and diverges with time in the absence of friction or dissipation. This random heating effect is usually encountered in phenomenological theories formulated in terms of stochastic differential equations, the epitome of which is the Langevin equation of Brownian motion. We discuss a simple discrete impulsive model that captures the essence of random heating and Brownian motion. The model may be regarded as a discrete analog of the Langevin equation, although it is developed ab initio. Its analysis requires only simple algebraic manipulations and elementary …


The Very Basics Of Sustainability - An Alternative Viewpoint, Jim Mcgovern Aug 2009

The Very Basics Of Sustainability - An Alternative Viewpoint, Jim Mcgovern

Other resources

This paper examines the context and meaning of the term ‘sustainability’, the factors that determine and govern climate on Earth, the population of the Earth and its trends and influencers, the requirements for sustaining life and the options that are available to humankind. Some viewpoints are presented that are alternative to ‘conventional alternative’ thinking. The author advocates keeping an open mind on all available options, including the use of oil, gas, coal, tar sands, carbon capture and sequestration, nuclear power etc., as well as the technologies that are more widely considered ‘green’ and also argues that humankind needs to face …


The Very Basics Of Sustainability - An Alternative Viewpoint (Slides With Audio) (Large File! To Speed Up Download, Right-Click On "Download" Link To Save To Own Pc.), Jim Mcgovern Aug 2009

The Very Basics Of Sustainability - An Alternative Viewpoint (Slides With Audio) (Large File! To Speed Up Download, Right-Click On "Download" Link To Save To Own Pc.), Jim Mcgovern

Other resources

This presentation sets out the very basics of ‘sustainability’, although a definition of sustainability is not attempted. Some of the very basics are the context in which the Earth and humankind exist in space and time, the Earth’s climate, the Earth’s population and humankind’s options and choices. The author advocates keeping an open mind on all available options, including the use of oil, gas, coal, tar sands, carbon capture and sequestration, nuclear power etc., as well as the technologies that are more widely considered ‘green’. The author also argues that, in addressing the challenges that humankind faces, globally concerted effort …


Chemistry Division Aug 2009

Chemistry Division

Sci-Tech News

The Chemistry Division is concerned with chemistry and chemical technology, and the economics, educational advances, and information handling of developments in the field of chemistry and related subjects.


Science-Technology Division Aug 2009

Science-Technology Division

Sci-Tech News

The objectives of the Science-Technology Division shall be to draw together those members of the Special Libraries Association having an interest in the role of library and information science as applied to the recording, retrieval and dissemination of knowledge and information in all areas of science and technology, and to promote and improve the communication, dissemination and use of such knowledge for the benefit of libraries and their users.


Winners Of The Sci-Tech Division Free Student Memberships Contest, Thea Allen Aug 2009

Winners Of The Sci-Tech Division Free Student Memberships Contest, Thea Allen

Sci-Tech News

No abstract provided.


Sci-Tech Book News Reviews Aug 2009

Sci-Tech Book News Reviews

Sci-Tech News

This section consists of 100 book reviews selected from Sci-Tech Book News, reprinted with the permission of Book News, Inc.


Generalized Mean Curvature Flow In Carnot Groups, Luca Capogna, Giovanna Citti Aug 2009

Generalized Mean Curvature Flow In Carnot Groups, Luca Capogna, Giovanna Citti

Mathematics Sciences: Faculty Publications

In this paper we study the generalized mean curvature flow of sets in the sub-Riemannian geometry of Carnot groups. We extend to our context the level sets method and the weak (viscosity) solutions introduced in the Euclidean setting in [4] and [12]. We establish two special cases of the comparison principle, existence, uniqueness and basic geometric properties of the flow.


Does Organic Modification Of Layered Double Hydroxides Improve The Fire Performance Of Pmma?, Calistor Nyambo, Dan Chen, Shengpei Shu, Charles A. Wilkie Aug 2009

Does Organic Modification Of Layered Double Hydroxides Improve The Fire Performance Of Pmma?, Calistor Nyambo, Dan Chen, Shengpei Shu, Charles A. Wilkie

Chemistry Faculty Research and Publications

The effect of modified layered double hydroxides (LDHs) on fire properties of poly(methyl methacrylate) is investigated. Organically-modified LDHs were prepared via rehydration of calcined hydrotalcite in a palmitate solution. Composites consisting of the organo-LDHs, unmodified hydrotalcite and calcined oxides were prepared with poly(methyl methacrylate) using melt blending. Thermal and fire properties of the (nano)composites were studied. The thermogravimetric analyses of the composites show an increase in thermal stability. Fire performance, evaluated using cone calorimetry, show that organically-modified LDHs composites give the best reductions in peak heat release rate, PHRR, i.e., 51% at 10% weight loading. Dispersion of the LDHs was …


Aqua {6,60-Dimethoxy-2,20-[Ethane-1,2- Diylbis(Nitrilomethylidyne)]Diphenolato}- (4-Hydroxybenzoato)Manganese(Iii), R. Reshma, V. Soumya, S. M. Simi, V. S. Thampidas, Robert D. Pike Aug 2009

Aqua {6,60-Dimethoxy-2,20-[Ethane-1,2- Diylbis(Nitrilomethylidyne)]Diphenolato}- (4-Hydroxybenzoato)Manganese(Iii), R. Reshma, V. Soumya, S. M. Simi, V. S. Thampidas, Robert D. Pike

Arts & Sciences Articles

The title compound, [Mn(C18H18N2O4)(C7H5O3)(H2O)], was synthesized by a template reaction of ethane-1,2-diamine and 3-methoxy­salicylaldehyde in presence of manganese(II) 4-hydroxy­benzoate. The Jahn-Teller-distorted manganese(III) centre has an octa­hedral geometry. Extensive O-HO hydrogen-bonding inter­actions generate a two-dimensional sheet structure parallel to (103).


Multiwavelength Observations Of Ls I+61 Degrees 303 With Veritas, Swift, And Rxte, P. T. Reynolds, Et. Al. Aug 2009

Multiwavelength Observations Of Ls I+61 Degrees 303 With Veritas, Swift, And Rxte, P. T. Reynolds, Et. Al.

Physical Sciences Publications

We present results from a long-term monitoring campaign on the TeV binary LSI +61° 303 with VERITAS at energies above 500 GeV, and in the 2-10 keV hard X-ray bands with RXTE and Swift, sampling nine 26.5 day orbital cycles between 2006 September and 2008 February. The binary was observed by VERITAS to be variable, with all integrated observations resulting in a detection at the 8.8σ (2006/2007) and 7.3σ (2007/2008) significance level for emission above 500 GeV. The source was detected during active periods with flux values ranging from 5% to 20% of the Crab Nebula, varying over the course …


Modelling, Design And Diagnostics For A Photoionised Plasma Experiment, I. M. Hall, T. Turmaz, R. C. Mancini, J. E. Bailey, G. Rochau, Michael Jonathan Rosenberg , '08, David H. Cohen, I. Golovkin, J. J. Macfarlane, M. E. Sherril, J. Abdallah, R. F. Heeter, M. E. Foord, S. H. Glenzer, H. A. Scott Aug 2009

Modelling, Design And Diagnostics For A Photoionised Plasma Experiment, I. M. Hall, T. Turmaz, R. C. Mancini, J. E. Bailey, G. Rochau, Michael Jonathan Rosenberg , '08, David H. Cohen, I. Golovkin, J. J. Macfarlane, M. E. Sherril, J. Abdallah, R. F. Heeter, M. E. Foord, S. H. Glenzer, H. A. Scott

Physics & Astronomy Faculty Works

Photoionised plasmas are common in astrophysical environments and new high resolution spectra from such sources have been recorded in recent years by the Chandra and XMM-Newton satellites. These provide a wealth of spectroscopic information and have motivated recent efforts aimed at obtaining a detailed understanding of the atomic-kinetic and radiative characteristics of photoionised plasmas. The Z-pinch facility at the Sandia National Laboratories is the most powerful terrestrial source of X-rays and provides an opportunity to produce photoionised plasmas in a well characterised radiation environment. We present modelling work and experimental design considerations for a forthcoming experiment at Sandia in which …


Search For Correlated Fluctuations In The B+ Decay Of Na-22, Mark P. Silverman, Wayne Strange Aug 2009

Search For Correlated Fluctuations In The B+ Decay Of Na-22, Mark P. Silverman, Wayne Strange

Faculty Scholarship

Claims for a “cosmogenic” force that correlates otherwise independent stochastic processes have been made for at least 10 years, based on visual inspection of histograms whose shapes were interpreted as suggestive of recurrent patterns. Building on our earlier work to test nuclear alpha, beta, and electron-capture decay processes for non-randomness, we searched for correlations in the time series of e+e- annihilations deriving from the decay of 22Na. Coincident gamma photons were counted within narrow time and energy windows over a period of 167 hours leading to a time series of more than 1 million events. Statistical …


Spectroscopic Imaging For The Detection And Identification Of Bacterial Contaminations, Michael Gilbert Aug 2009

Spectroscopic Imaging For The Detection And Identification Of Bacterial Contaminations, Michael Gilbert

Doctoral Dissertations

There exist many types of harmful bacteria that can contaminate foods and cause serious illness, which often have their own best courses of treatment. This requires the classification of different types of bacteria. Traditional methods of bacterial identification, while able to provide accurate classification, are often very time-consuming processes. In the case of a potentially fatal bacterial infection, time is often of the essence. FTIR spectroscopy is a faster, more practical alternative that can discriminate different strains of bacteria, based on their spectral signatures, with high confidence.

Bacterial contaminations on food exist as small, localized colonies that must be found …


Reaction-Diffusion Systems With A Nonlinear Rate Of Growth, Yubing Wan Aug 2009

Reaction-Diffusion Systems With A Nonlinear Rate Of Growth, Yubing Wan

Theses and Dissertations - UTB/UTPA

In the literature there are quite a few elegant approaches which have been proposed to find (he first integrals of nonlinear differential equations. Recently, the modified Prelle-Singer method for finding the first integrals of second-order nonlinear ordinary differential equations (ODEs) has attracted considerable attention. Many researchers used this method to derive the first integrals to various systems. In this thesis, we are concerned with the first integrals for reaction-diffusion systems with a nonlinear rate of growth. Under certain parametric conditions we express the first integrals explicitly by applying an analytical method as well as the modified Prelle-Singer method.


Investigations Of 2-Thiazoline-2-Thiol As A Ligand: Synthesis And X-Ray Structures Of [Mn2(Co)7(Μ-Ns2C3H4)2] And [Mn(Co)3(Pph3)(Κ2-Ns2C3H4)], Shishir Ghosh, Faruque Ahmed, Rafique Al-Mamun, Daniel T. Haworth, Sergey V. Lindeman, Tasneem Siddiquee, Dennis W. Bennett, Shariff E. Kabir Aug 2009

Investigations Of 2-Thiazoline-2-Thiol As A Ligand: Synthesis And X-Ray Structures Of [Mn2(Co)7(Μ-Ns2C3H4)2] And [Mn(Co)3(Pph3)(Κ2-Ns2C3H4)], Shishir Ghosh, Faruque Ahmed, Rafique Al-Mamun, Daniel T. Haworth, Sergey V. Lindeman, Tasneem Siddiquee, Dennis W. Bennett, Shariff E. Kabir

Chemistry Faculty Research and Publications

Treatment of Mn2(CO)10 with 2-thiazoline-2-thiol in the presence of Me3NO at room temperature afforded the dimanganese complexes [Mn2(CO)7(μ-NS2C3H4)2] (1) and [Mn2(CO)6(μ-NS2C3H4)2] (2) in 51 and 34% yields, respectively. Compound 1 was quantitatively converted into 2 when reacted with one equiv of Me3NO. Reaction of 1 with triphenylphosphine at room temperature furnished the mononuclear complex [Mn(CO)3(PPh3)(κ 2 …


Analysis And Modeling Of Ducted And Evanescent Gravity Waves Observed In The Hawaiian Airglow, D. B. Simkhada, J. B. Snively, Michael J. Taylor, S. J. Franke Aug 2009

Analysis And Modeling Of Ducted And Evanescent Gravity Waves Observed In The Hawaiian Airglow, D. B. Simkhada, J. B. Snively, Michael J. Taylor, S. J. Franke

All Physics Faculty Publications

Short-period gravity waves of especially-small horizontal scale have been observed in the Maui, Hawaii airglow. Typical small-scale gravity wave events have been investigated, and intrinsic wave propagation characteristics have been calculated from simultaneous meteor radar wind measurements. Here we report specific cases where wave structure is significantly determined by the local wind structure, and where wave characteristics are consistent with ducted or evanescent waves throughout the mesopause region. Two of the documented events, exhibiting similar airglow signatures but dramatically different propagation conditions, are selected for simple numerical modeling case studies. First, a Doppler-ducted wave trapped within relatively weak wind flow …


Reducing Source Load In Bittorrent, Brian Sanderson, Daniel Zappala Aug 2009

Reducing Source Load In Bittorrent, Brian Sanderson, Daniel Zappala

Faculty Publications

One of the main goals of BitTorrent is to reduce load on web servers by encouraging clients to share content between themselves. However, BitTorrent’s current design relies heavily on the original source to serve a disproportionate amount of the file. We modify standard BitTorrent software so that a source determines the current popularity of each of the blocks of a file and tries to serve only those blocks that are rare. Using extensive PlanetLab experiments, we show that this modification can save a significant amount of the source’s upload bandwidth, with the tradeoff of some increased peer download time. In …


Fan Cohomology And Equivariant Chow Rings Of Toric Varieties, Mu-Wan Huang Aug 2009

Fan Cohomology And Equivariant Chow Rings Of Toric Varieties, Mu-Wan Huang

Department of Mathematics: Dissertations, Theses, and Student Research

Toric varieties are varieties equipped with a torus action and constructed from cones and fans. In the joint work with Suanne Au and Mark E. Walker, we prove that the equivariant K-theory of an affine toric variety constructed from a cone can be identified with a group ring determined by the cone. When a toric variety X(Δ) is smooth, we interpret equivariant K-groups as presheaves on the associated fan space Δ. Relating the sheaf cohomology groups to equivariant K-groups via a spectral sequence, we provide another proof of a theorem of Vezzosi and Vistoli: equivariant K …


Cyclic Shifts Of The Van Der Corput Set, Dmitriy Bilyk Aug 2009

Cyclic Shifts Of The Van Der Corput Set, Dmitriy Bilyk

Faculty Publications

In 1980, K. Roth showed that the expected value of the L2 discrepancy of the cyclic shifts of the N-point van der Corput set is bounded by a constant multiple of √logN, thus guaranteeing the existence of a shift with asymptotically minimal L2 discrepancy. In the present paper, we construct a specific example of such a shift.


Linear Reconfiguration Of Cube-Style Modular Robots, Greg Aloupis, Sébastien Collette, Mirela Damian, Erik D. Demaine, Robin Flatland, Stefan Langerman, Joseph O'Rourke, Suneeta Ramaswami, Vera Sacristán, Stefanie Wuhrer Aug 2009

Linear Reconfiguration Of Cube-Style Modular Robots, Greg Aloupis, Sébastien Collette, Mirela Damian, Erik D. Demaine, Robin Flatland, Stefan Langerman, Joseph O'Rourke, Suneeta Ramaswami, Vera Sacristán, Stefanie Wuhrer

Computer Science: Faculty Publications

In this paper we propose a novel algorithm that, given a source robot S and a target robot T, reconfigures S into T. Both S and T are robots composed of n atoms arranged in 2×2×2 meta-modules. The reconfiguration involves a total of O(n) atomic operations (expand, contract, attach, detach) and is performed in O(n) parallel steps. This improves on previous reconfiguration algorithms [D. Rus, M. Vona, Crystalline robots: Self-reconfiguration with compressible unit modules, Autonomous Robots 10 (1) (2001) 107-124; S. Vassilvitskii, M. Yim, J. Suh, A complete, local and parallel reconfiguration algorithm for cube style modular robots, in: Proc. …


Link Scheduling For Scalable Data Aggregation, Jamie Macbeth, Majid Sarrafzadeh Aug 2009

Link Scheduling For Scalable Data Aggregation, Jamie Macbeth, Majid Sarrafzadeh

Computer Science: Faculty Publications

We explore the link scheduling optimization problem in the context of scalable in-network data aggregation, extending results for broadcast networks to routing in general networks. The primary vehicle for resource preservation is transmission suppression. For certain types of queries, nodes can avoid transmitting records if they can locally infer that their data is not needed to execute the query. We introduce a novel protocol paradigm for duplicate-insensitive exemplary monotonic (e.g. MIN and MAX) data aggregation queries. Performance of query execution in these networks is measured through collective expected number of transmissions in the network, and is linked to the minimum …


Detection Of Protease-Resistant Cervid Prion Protein In Water From A Cwd-Endemic Area, T. A. Nichols, Bruce Pulford, A. Christy Wyckoff, Crystal Meyerett, Brady Michel, Kevin Gertig, Edward A. Hoover, Jean E. Jewell, Glenn C. Telling, Mark D. Zabel Aug 2009

Detection Of Protease-Resistant Cervid Prion Protein In Water From A Cwd-Endemic Area, T. A. Nichols, Bruce Pulford, A. Christy Wyckoff, Crystal Meyerett, Brady Michel, Kevin Gertig, Edward A. Hoover, Jean E. Jewell, Glenn C. Telling, Mark D. Zabel

United States Department of Agriculture Wildlife Services: Staff Publications

Chronic wasting disease (CWD) is the only known transmissible spongiform encephalopathy affecting free-ranging wildlife. Although the exact mode of natural transmission remains unknown, substantial evidence suggests that prions can persist in the environment, implicating components thereof as potential prion reservoirs and transmission vehicles. CWD-positive animals may contribute to environmental prion load via decomposing carcasses and biological materials including saliva, blood, urine and feces. Sensitivity limitations of conventional assays hamper evaluation of environmental prion loads in soil and water. Here we show the ability of serial protein misfolding cyclic amplification (sPMCA) to amplify a 1.3 x 10-7 dilution of CWD-infected …


Tactics And Economics Of Wildlife Oral Rabies Vaccination, Canada And The United States, Ray T. Sterner, Martin I. Meltzer, Stephanie A. Shwiff, Dennis Slate Aug 2009

Tactics And Economics Of Wildlife Oral Rabies Vaccination, Canada And The United States, Ray T. Sterner, Martin I. Meltzer, Stephanie A. Shwiff, Dennis Slate

United States Department of Agriculture Wildlife Services: Staff Publications

Progressive elimination of rabies in wildlife has been a general strategy in Canada and the United States; common campaign tactics are trap–vaccinate–release (TVR), point infection control (PIC), and oral rabies vaccination (ORV). TVR and PIC are labor intensive and the most expensive tactics per unit area (≈$616/km2 [in 2008 Can$, converted from the reported $450/km2 in 1991 Can$] and ≈$612/km2 [$500/km2 in 1999 Can$], respectively), but these tactics have proven crucial to elimination of raccoon rabies in Canada and to maintenance of ORV zones for preventing the spread of raccoon rabies in the United States. Economic …


Response To Plevin: Implications For Life Cycle Emissions Regulations, Adam Liska, Kenneth G. Cassman Aug 2009

Response To Plevin: Implications For Life Cycle Emissions Regulations, Adam Liska, Kenneth G. Cassman

Nebraska Center for Energy Sciences Research: Publications

A robust dialogue concerning appropriate parameter values for life cycle assessment (LCA) models is necessary because regulation of life cycle greenhouse gas (GHG) emissions from biofuel systems will determine market access and government subsidies for biofuel producers.1 Such a dialogue is also critical for creating more accurate LCA methods that will be accepted by scientists, industry, and the public. Plevin (2009) has identified multiple concerns with the life cycle emissions methodology employed in our previous analysis using the Biofuel Energy Systems Simulator (BESS) model (Liska et al. 2009), but only four alter our estimates substantially: (1) denaturant addition (+6.5 gCO …


Photoionization Of Rare Gas Clusters, Huaizhen Zhang Aug 2009

Photoionization Of Rare Gas Clusters, Huaizhen Zhang

Dissertations

This thesis concentrates on the study of photoionization of van der Waals clusters with different cluster sizes. The goal of the experimental investigation is to understand the electronic structure of van der Waals clusters and the electronic dynamics. These studies are fundamental to understand the interaction between UV-X rays and clusters. The experiments were performed at the Advanced Light Source at Lawrence Berkeley National Laboratory. The experimental method employs angle-resolved time-of-flight photoelectron spectrometry, one of the most powerful methods for probing the electronic structure of atoms, molecules, clusters and solids.

The van der Waals cluster photoionization studies are focused on …


The John Muir Newsletter, Fall 2009, The John Muir Center For Environmental Studies Aug 2009

The John Muir Newsletter, Fall 2009, The John Muir Center For Environmental Studies

Muir Center Newsletters (1981-2015)

THE JOHN MUIR NEWSLETTER FALL 2009 UNIVERSITY OF THE PACIFIC STOCKTON, CALIFORNIA Muir Center Has a New Home & New Staff This past June, Marilyn Norton, Administrative Assistant and Budget Accountant for the Division of Social Sciences, retired after fifteen years at Pacific. She and her husband, Dan, along with pets Abbey and Bear live in Mokelumne Hill, where they remain active in Restore Hetch Hetchy, Yosemite Associates, and many conservation issues. We wish her the best in the years ahead as she explores more of the high country so familiar to Muir. During August, John Muir Center was moved …