Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

2006

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 3001 - 3030 of 11491

Full-Text Articles in Entire DC Network

An Economic-Engineering Optimization For The Binational Mexico-U.S. Lower Colorado River Delta: The Mexicali Valley Case Study, Josue Medellin-Azuara, Jay R. Lund Jul 2006

An Economic-Engineering Optimization For The Binational Mexico-U.S. Lower Colorado River Delta: The Mexicali Valley Case Study, Josue Medellin-Azuara, Jay R. Lund

2006

Agricultural water use in the binational Lower Colorado River Basin is about ninety percent of all the beneficial use. Fast growing border cities of Baja California and conservation uses will increase their water allocations in the near future. The CALVIN economic-engineering model was used to evaluate the benefits and costs of a variety of water management strategies in the Lower Colorado River Delta in Mexico. Results show that at 2025 water demand conditions, agriculture seems to be the most suitable donor of water to other sectors. Wastewater reuse for irrigation and/or conservation purposes may reduce dependence on agricultural water imports …

Go to article

Towards A Water Leasing/Banking System On The Middle Rio Grande: Progress To Date, David Brookshire Et Al. Jul 2006

Towards A Water Leasing/Banking System On The Middle Rio Grande: Progress To Date, David Brookshire Et Al.

2006

A recent report details the limited nature of water leasing/banking in the Western U.S. (West Water Research, 2004). The report provides an analysis of water banking legislation policies and programs in 12 Western states. There are 23 active water banks of which seven are market based pricing, meaning that the price is negotiated between the buyer and the seller with one bank having online negotiations. The other 16 banks are fixed pricing or administrative pricing schemes that are set annually. Length of transaction varies and the number of transactions is limited annually. Here we explore the role of water leasing/banking …

Go to article

Climate Change And Water Supply Adaptation In California 2050, Josue Medellin-Azuara Jul 2006

Climate Change And Water Supply Adaptation In California 2050, Josue Medellin-Azuara

2006

The cost and ability of California’s water supply system to adapt to major changes in climate are assessed using the CALVIN economic-engineering model. A dry climate warming GCM scenario is used to create statewide hydrologic changes, which are combined with 2050 water demands in the model. Results indicate that dry climate warming could have significant economic effects on California’s water supply, particularly for some agricultural areas. However, a portfolio of water management adaptations allows the magnitude of these economic impacts to be small compared with the overall state economy.

Go to article

Relative Risk Regression In Medical Research: Models, Contrasts, Estimators, And Algorithms, Thomas Lumley, Richard Kronmal, Shuangge Ma Jul 2006

Relative Risk Regression In Medical Research: Models, Contrasts, Estimators, And Algorithms, Thomas Lumley, Richard Kronmal, Shuangge Ma

UW Biostatistics Working Paper Series

The relative risk or prevalence ratio is a natural and familiar summary of association between a binary outcome and an exposure or intervention. For rare events, the relative risk can be approximately estimated by logistic regression. For common events estimation is more difficult. We review proposed estimation algorithms for relative risk regression. Some of these give inconsistent estimates or invalid standard errors. We show that the methods that give correct inference can be viewed as arising from a family of quasilikelihood estimating functions for the same generalized linear model, differing in their efficiency and in their robustness to outlying values …

Go to article

Indiana Wildlife Disease News, Volume 1, Issue 3 -- July 2006 Jul 2006

Indiana Wildlife Disease News, Volume 1, Issue 3 -- July 2006

Indiana Wildlife Disease News

Special points of interest:
• Special Issue on rabies
• Oral rabies vaccination zone
• Update - avian influenza surveillance in wild birds in Indiana
• Indiana Rabies Task Force
• An update on wildlife disease in Indiana and surrounding states

Inside this issue:
Oral Rabies Vaccination 2
Mechanics of a Rabies Infection 2
Rabies in Indiana 3 Submitting Animals for Testing 4
AI Update Avian Botulism 5
Canine Distemper 5
Indiana Rabies Task Force 6

Go to article

Water Options In California: Effective Management Of Supply-Side Risk, Richard Howitt, Jeffrey Williams Jul 2006

Water Options In California: Effective Management Of Supply-Side Risk, Richard Howitt, Jeffrey Williams

2006

In California, the tremendous spatial and temporal variation in precipitation suggests that flexible contractual arrangements, such as option contracts, would increase allocative efficiency of water over time and space. Under such arrangements, a water agency pays an option premium for the right to purchase water at some point in the future, if water conditions turn out to be dry. The premium represents the value of the flexibility gained by the buyer from postponing its decision whether to purchase water. In California, the seller of existing option arrangements is often an agricultural producer who can fallow land, in the event that …

Go to article

Towards Greater Certainty In Upper Klamath Basin Water Management, Brent Boehlert, William K. Jaeger Jul 2006

Towards Greater Certainty In Upper Klamath Basin Water Management, Brent Boehlert, William K. Jaeger

2006

In 2001, an extreme drought tightened water supply in the Upper Klamath Basin (basin) while earlier 2001 increases in Endangered Species Act (ESA) water requirements for basin fish species elevated demands. The Bureau of Reclamation (Reclamation), which manages irrigation water in parts of the basin located near the Oregon-California border, responded by severely curtailing water allocations to Reclamation Project (project) irrigators for the 2001 growing season. Consequently, project irrigators lost approximately $35 million in farm income, demonstrating that ESA requirements have significantly changed how water must be managed in the basin. These circumstances prompted Reclamation to establish a federally-funded water …

Go to article

Uncertainties In The Transient Capture-Zone Estimates Of Groundwater Supply Wells, Velimir V. Vesselinov Jul 2006

Uncertainties In The Transient Capture-Zone Estimates Of Groundwater Supply Wells, Velimir V. Vesselinov

2006

Capture zones of water-supply wells are a widely used analysis tool for protection of groundwater resources. Transient analyses of capture zones provide a more complete assessment than the commonly applied steady-state analyses. Previously, we have demonstrated that advection-only analyses can produce biased transient capture-zone estimates. Therefore, it is important to consider the dispersion of contaminant plumes. Here, we extend our study to incorporate temporal and spatial distribution in the contaminant sources and their respective uncertainties. Our analysis indicates that the capture-zone estimates can be very sensitive to the transients in the contaminant releases. Even relatively small uncertainties in the contaminant …

Go to article

Accumulation Of Phycotoxins In The Mussel Mytilus Galloprovincialis From The Central Adriatic Sea, Maja Pavela-Vrančić, Ivana Ujević, Živana Ninčević Gladan, Ambrose Furey Jul 2006

Accumulation Of Phycotoxins In The Mussel Mytilus Galloprovincialis From The Central Adriatic Sea, Maja Pavela-Vrančić, Ivana Ujević, Živana Ninčević Gladan, Ambrose Furey

Physical Sciences Publications

Surveys of DSP (Diarrheic Shellfish Poisoning) toxin profiles in the mussel Mytilus galloprovincialis from coastal waters of the central Adriatic Sea, over the years 1995 to 2001, demonstrate that incidents of shellfish toxicity in this area are dominated by the occurrence of okadaic acid (OA) and a PTX derivative, 7-epi-pectenotoxin-2-seco acid (7-epi-PTX-2SA). Toxin composition and the relative ratio of toxic components in shellfish is in correlation with the occurrence of DSP producing organisms from the Dinophysis species along with Prorocentrum micans and Lingulodinium polyedrum. The occurrence of D. sacculus shortly before the appearance of OA in shellfish implicates its possible …

Go to article

Characterizing Dynamic Power And Data Rate Policies For Wirelessusb Networks, Jeffrey L. Barlow Jul 2006

Characterizing Dynamic Power And Data Rate Policies For Wirelessusb Networks, Jeffrey L. Barlow

Theses and Dissertations

Wireless communication is increasingly ubiquitous. However, mobility depends intrinsically on battery life. Power can be conserved at the Media Access Control (MAC) layer by intelligently adjusting transmission power level and data rate encoding. WirelessUSB is a low-power, low-latency wireless technology developed by Cypress Semiconductor Corporation for human interface devices such as keyboards and mice. WirelessUSB devices conserve power by employing power-efficient hardware, dynamic power level adjustment and dynamic data rate adjustment. We characterize the effects on power consumption of dynamically adjusting node power using two dynamic power negotiation techniques as well as two reactive techniques. We also characterize the effects …

Go to article

Comparing Time And Accuracy Of Building Information Modeling To On-Screen Takeoff For A Quantity Takeoff Of A Conceptual Estimate, Morgan A. Alder Jul 2006

Comparing Time And Accuracy Of Building Information Modeling To On-Screen Takeoff For A Quantity Takeoff Of A Conceptual Estimate, Morgan A. Alder

Theses and Dissertations

Estimating is a critical aspect of every construction project. The most tedious component of an estimate is the quantity takeoff. Different tools are available to improve an estimator's productivity for a quantity takeoff. Faster quantity takeoffs enable estimator to bid more jobs. This study analyzed the time and accuracy of performing quantity takeoffs when using building information modeling (BIM) through a comparison study using Revit (BIM software) and On-Center's OST. In preparation for the study the researcher conducted a pilot study. Participants of the study were asked to perform a quantity takeoff using both Revit and OST. Their resulting data …

Go to article

Overview Of Artificial Recharge Projects: Planning And Implementation Challenges, Daniel B. Stephens Jul 2006

Overview Of Artificial Recharge Projects: Planning And Implementation Challenges, Daniel B. Stephens

2006

Artificial recharge is a process to replenish an aquifer through engineered systems. Systems commonly used for artificial recharge include spreading basins, infiltration galleries and vadose zone wells. Artificial recharge may also be accomplished by direct subsurface injection. Sources of water for recharge may include diverted storm water runoff and stream flow or recycled water. Artificial recharge projects may be key elements in the long term water resources management plans for many New Mexico communities and developments. This paper will discuss the multiple factors which require careful consideration for the successful design of an artificial recharge project. Most important are the …

Go to article

Fast Algorithms Using Minimal Data Structures For Common Topological Relationships In Large, Irregularly-Spaced Topographic Data Sets, Thomas H. Meyer Jul 2006

Fast Algorithms Using Minimal Data Structures For Common Topological Relationships In Large, Irregularly-Spaced Topographic Data Sets, Thomas H. Meyer

Department of Natural Resources and the Environment Articles

Digital terrain models (DTM) typically contain large numbers of postings, from hundreds of thousands to billions. Many algorithms that run on DTMs require topological knowledge of the postings, such as finding nearest neighbors, finding the posting closest to a chosen location, etc. If the postings are arranged irregu- larly, topological information is costly to compute and to store. This paper offers a practical approach to organizing and searching irregularly-space data sets by presenting a collection of efficient algorithms (O(N),O(lgN)) that compute important topological relationships with only a simple supporting data structure. These relationships include finding the …

Go to article

Shape-Persistent Macrocyclic Aromatic Tetrasulfonamides: Molecules With Nanosized Cavities And Their Nanotubular Assemblies In Solid State, Lan He, Yu An, Lihua Yuan, Wen Feng, Minfeng Li, Dechun Zhang, Kazuhiro Yamato, Chong Zheng, Xiao Cheng Zeng, Bing Gong Jul 2006

Shape-Persistent Macrocyclic Aromatic Tetrasulfonamides: Molecules With Nanosized Cavities And Their Nanotubular Assemblies In Solid State, Lan He, Yu An, Lihua Yuan, Wen Feng, Minfeng Li, Dechun Zhang, Kazuhiro Yamato, Chong Zheng, Xiao Cheng Zeng, Bing Gong

Xiao Cheng Zeng Publications

Alkoxy side-chain-flanked diarylsulfonamide serves as a reliable structural motif for constructing macrocyclic aromatic tetrasulfonamides. This 90° structural motif is persistent both in solution and in the solid state, which allows the one-step formation of tetrasulfonamide macrocycles. These macrocycles adopt a cone-shaped conformation in solution and in the solid state. For each molecule, an interior cavity surrounded by the aromatic residues is formed. The cavity sizes of the macrocycles can be tuned by incorporating aromatic residues of proper sizes. Guest (solvent) molecules are found in the cavities and bound by side chains. In solution, 1H NMR shows that the cone …

Go to article

Image Segmentation By Energy And Related Functional Minimization Methods, Eric Hudson Mason Jul 2006

Image Segmentation By Energy And Related Functional Minimization Methods, Eric Hudson Mason

Dissertations

Effective and efficient methods for partitioning a digital image into image segments, called ¿image segmentation,¿ have a wide range of applications that include pattern recognition, classification, editing, rendering, and compressed data for image search. In general, image segments are described by their geometry and similarity measures that identify them. For example, the well-known optimization model proposed and studied in depth by David Mumford and Jayant Shah is based on an L2 total energy functional that consists of three terms that govern the geometry of the image segments, the image fidelity (or closeness to the observed image), and the prior …

Go to article

Ground-Water Quality Beneath Irrigated Cropland Of The Northern And Southern High Plains Aquifer, Nebraska And Texas, 2003–04, Jennifer S. Stanton, Lynne Fahlquist Jul 2006

Ground-Water Quality Beneath Irrigated Cropland Of The Northern And Southern High Plains Aquifer, Nebraska And Texas, 2003–04, Jennifer S. Stanton, Lynne Fahlquist

United States Geological Survey: Publications

A study of the quality of ground water beneath irrigated cropland was completed for the northern and southern High Plains aquifer. Ground-water samples were collected from 30 water-table monitoring wells in the northern agricultural land-use (NAL) study area in Nebraska in 2004 and 29 water-table monitoring wells in the southern agricultural land-use (SAL) study area in Texas in 2003. The two study areas represented different agricultural and hydrogeologic settings. The primary crops grown in the NAL study area were corn and soybeans, and the primary crop in the SAL study area was cotton. Overall, pesticide and fertilizer application rates were …

Go to article

Uab Experts Available To Discuss Back-To-School Topics, Staff Jul 2006

Uab Experts Available To Discuss Back-To-School Topics, Staff

Browse All News

No abstract provided.

Go to article

How A Master Teacher Uses Questioning Within A Mathematical Discourse Community, Omel Angel Contreras Jul 2006

How A Master Teacher Uses Questioning Within A Mathematical Discourse Community, Omel Angel Contreras

Theses and Dissertations

Recent scholarly work in mathematics education has included a focus on learning mathematics with understanding (Hiebert & Carpenter, 1992; Hiebert et al., 1997; Fennema & Romberg, 1999; National Council of Teachers of Mathematics, 2000). Hiebert et al. (1997) discussed two processes that they suggested increase understanding and that are central to this study: reflection and communication. Learning mathematics with understanding requires that the students create a deeper knowledge of mathematics through reflection and communication. The environment in which such learning can take place must include patterns of behavior, known as social norms that promote deeper thinking. When the social norms …

Go to article

Magnetic Instabilities And Phase Diagram Of The Double-Exchange Model In Infinite Dimensions, R. S. Fishman, F. Popescu, G. Alvarez, J. Moreno, Th Maier, M. Jarrell Jul 2006

Magnetic Instabilities And Phase Diagram Of The Double-Exchange Model In Infinite Dimensions, R. S. Fishman, F. Popescu, G. Alvarez, J. Moreno, Th Maier, M. Jarrell

Faculty Publications

Dynamical mean-field theory is used to study the magnetic instabilities and phase diagram of the double-exchange (DE) model with Hund's coupling J H > 0 in infinite dimensions. In addition to ferromagnetic (FM) and antiferromagnetic (AF) phases, the DE model also supports a broad class of short-range ordered (SRO) states with extensive entropy and short-range magnetic order. For any site on the Bethe lattice, the correlation parameter q of an SRO state is given by the average q = 〈sin2(θ i/2)〉, where θi is the angle between any spin and its neighbours. Unlike the FM (q = 0) and AF (q …

Go to article

Wind And Solar Energy Driven Ro Brackish Water Desalination, Clark C. K. Liu, Krispin Fernandes Jul 2006

Wind And Solar Energy Driven Ro Brackish Water Desalination, Clark C. K. Liu, Krispin Fernandes

2006

The principal objective of this Research project was to develop a simple cost-effective desalination system for Pacific islands and other remote coastal communities where both freshwater and electricity are in short supply.

Go to article

The Effect Of Protein Dielectric Coefficient On The Ionic Selectivity Of A Calcium Channel, Douglas Henderson, Dezso Boda, Monika Valisko, Bob Eisenberg, Wolfgang Nonner, Dirk Gillespie Jul 2006

The Effect Of Protein Dielectric Coefficient On The Ionic Selectivity Of A Calcium Channel, Douglas Henderson, Dezso Boda, Monika Valisko, Bob Eisenberg, Wolfgang Nonner, Dirk Gillespie

Faculty Publications

Calcium-selective ion channels are known to have carboxylate-rich selectivity filters, a common motif that is primarily responsible for their high Ca2+ affinity. Different Ca2+ affinities ranging from micromolar (the L-type Ca channel) to millimolar (the ryanodine receptor channel) are closely related to the different physiological functions of these channels. To understand the physical mechanism for this range of affinities given similar amino acids in their selectivity filters, we use grand canonical Monte Carlo simulations to assess the binding of monovalent and divalent ions in the selectivity filter of a model Ca channel. We use a reduced model where the electrolyte …

Go to article

Ground-Water Quality Of The Northern High Plains Aquifer, 1997, 2002–04, Jennifer S. Stanton, Sharon L. Qi Jul 2006

Ground-Water Quality Of The Northern High Plains Aquifer, 1997, 2002–04, Jennifer S. Stanton, Sharon L. Qi

United States Geological Survey: Publications

An assessment of ground-water quality in the northern High Plains aquifer was completed during 1997 and 2002–04. Ground-water samples were collected at 192 low-capacity, primarily domestic wells in four major hydrogeologic units of the northern High Plains aquifer—Ogallala Formation, Eastern Nebraska, Sand Hills, and Platte River Valley. Each well was sampled once, and water samples were analyzed for physical properties and concentrations of nitrogen and phosphorus compounds, pesticides and pesticide degradates, dissolved solids, major ions, trace elements, dissolved organic carbon (DOC), radon, and volatile organic compounds (VOCs). Tritium and microbiology were analyzed at selected sites. The results of this assessment …

Go to article

Second Graders' Solution Strategies And Understanding Of A Combination Problem, Tiffany Marie Hessing Jul 2006

Second Graders' Solution Strategies And Understanding Of A Combination Problem, Tiffany Marie Hessing

Theses and Dissertations

I inquire about second graders' capabilities of developing solution strategies and the original variety of strategies they bring forth while solving a combination problem. Based on analysis of the data presented in this paper, students developed five different general strategies. After analyzing what the second grade students were capable of developing, we can conclude that young children are capable of developing powerful systematic strategies grounded in their personal experiences. This research shows that even when the teacher does not foster personal agency, children will still exercise agency. The social interactions in the classroom helped students learn to propose mathematical ideas, …

Go to article

Specialization Of Java Generic Types, Elena Machkasova, Sam Bevier Jul 2006

Specialization Of Java Generic Types, Elena Machkasova, Sam Bevier

Faculty Working Papers

No abstract provided.

Go to article

Grand Valley Forum, Volume 031, Number 02, July 17, 2006, Grand Valley State University Jul 2006

Grand Valley Forum, Volume 031, Number 02, July 17, 2006, Grand Valley State University

2006-2007, Volume 31

Grand Valley Forum is Grand Valley State's faculty and staff newsletter, published from 1976 to the present.

Go to article

Computerization Of Primary Care In The United States, James Anderson, E. Andrew Balas Jul 2006

Computerization Of Primary Care In The United States, James Anderson, E. Andrew Balas

RCHE Publications

The objective of this study was to assess the current level of information technology use by primary care ‎physicians in the U.S. Primary care physicians listed by the American Medical Association were contacted ‎by e-mail and asked to complete a Web-based questionnaire. A to¬tal of 2,145 physicians responded. ‎Overall, between 20% and 25% of primary care physicians reported using electronic medical records, e-‎prescribing, point-of-care decision support tools, and electronic communication with patients. This ‎indicates a slow rate of adoption since 2000. Differences in adoption rates suggest that future surveys need ‎to differentiate primary care and office-based physicians by specialty. An …

Go to article

Minimal Rankings And The A-Rank Number Of A Path, Victor Kostyuk, Darren Narayan, Victoria Shults Jul 2006

Minimal Rankings And The A-Rank Number Of A Path, Victor Kostyuk, Darren Narayan, Victoria Shults

Articles

Given a graph G, a function f:V(G)→ {1,2,…,k} is a k-ranking of G if f(u)=f(v) implies every u-v path contains a vertex w such that f(w)>f(u). A k-ranking is minimal if the reduction of any label greater than 1 violates the described ranking property. The arank number of a graph, denoted ψr(G), is the largest k such that G has a minimal k-ranking. We present new results involving minimal k-rankings of paths. In particular, we determine ψr(Pn), a problem posed by Laskar and Pillone in 2000 (Refer to PDF file for exact formulas).

Go to article

Geophysical Investigations And Groundwater Modeling Of The Hydrologic Conditions At Masaya Caldera, Nicaragua, Richard Eric Macneil Jul 2006

Geophysical Investigations And Groundwater Modeling Of The Hydrologic Conditions At Masaya Caldera, Nicaragua, Richard Eric Macneil

USF Tampa Graduate Theses and Dissertations

Masaya volcano, Nicaragua, has been the site of tremendous Plinian basaltic eruptions. Two eruptions ~6,500 and 2,250 BP formed the 6 kilometer (km) x 11 km, northwest trending Masaya caldera. The present day active Santiago Crater within the caldera is the site of persistent volcano degassing and occasional phreatic explosions. While the mechanism responsible for these phreatic explosions is unclear, one possible explanation is the interaction of groundwater with the shallow magma chamber beneath Masaya. This interaction with meteoric water is supported by the substantial steam discharge from the vent, which is significantly larger than other similar volcanoes in the …

Go to article

Polyvinylidene Fluoride–Trifluoroethylene As A Reservoir For Absorbed Water, P.A. Jacobson, Luis G. Rosa, Kristin Kraemer, Stephen Ducharme, Peter A. Dowben Jul 2006

Polyvinylidene Fluoride–Trifluoroethylene As A Reservoir For Absorbed Water, P.A. Jacobson, Luis G. Rosa, Kristin Kraemer, Stephen Ducharme, Peter A. Dowben

Peter Dowben Publications

The absorption of water in Langmuir–Blodgett films of ferroelectric copolymers of polyvinylidene fluoride with trifluoroethylene is shown to depend upon the film thickness. This water absorption can have a profound effect on the dielectric properties of the copolymer films.

Go to article

A Genetic Algorithm Approach To Solve For Multiple Solutions Of Inverse Kinematics Using Adaptive Niching And Clustering, Saleh Tabandeh, Christopher M. Clark, William Melek Jul 2006

A Genetic Algorithm Approach To Solve For Multiple Solutions Of Inverse Kinematics Using Adaptive Niching And Clustering, Saleh Tabandeh, Christopher M. Clark, William Melek

Computer Science and Software Engineering

Inverse kinematics is a nonlinear problem that may have multiple solutions. A Genetic Algorithm(GA) for solving the inverse kinematics of a serial robotic manipulator is presented. The algorithm is capable of finding multiple solutions of the inverse kinematics through niching methods. Despite the fact that the number and position of solutions in the search space depends on the the position and orientation of the end-effector as well as the configuration of the robot, the number of GA parameters that must be set by a user are limited to a minimum through the use of an adaptive niching method. The only …

Go to article

First Prev Next Last