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2006

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Articles 3511 - 3540 of 5872

Full-Text Articles in Physical Sciences and Mathematics

2006 Chesapeake Bay Bridge Tunnel Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans Jan 2006

2006 Chesapeake Bay Bridge Tunnel Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans

Miscellaneous

These calendars are produced monthly using David Evans' Tidecal.

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Pure Extensions Of Locally Compact Abelian Groups, Peter Loth Jan 2006

Pure Extensions Of Locally Compact Abelian Groups, Peter Loth

Mathematics Faculty Publications

In this paper, we study the group Pext(C,A) for locally compact abelian (LCA) groups A and C. Sufficient conditions are established for Pext(C,A) to coincide with the first Ulm subgroup of Ext(C,A). Some structural information on pure injectives in the category of LCA groups is obtained. Letting K denote the class of LCA groups which can be written as the topological direct sum of a compactly generated group and a discrete group, we determine the groups G in K which are pure injective in the category of LCA groups. Finally we describe those groups G in K such that every …

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Effects Of Carbonation On The Mineral Composition Of Cement Kiln Dust, Cecilia P. Anderson Jan 2006

Effects Of Carbonation On The Mineral Composition Of Cement Kiln Dust, Cecilia P. Anderson

Dissertations, Master's Theses and Master's Reports - Open

Due to their relatively high calcium oxide content, industrial mineral oxide wastes are potential candidates for mineral sequestration of carbon dioxide (CO2). Cement kiln dust (CKD), a byproduct of cement manufacturing contains 20-60% CaO making it a possible candidate for CO2 sequestration. In this study, three types of CKD are characterized, before and after carbonation, using environmental scanning electron microscopy and energy dispersive x-ray microanalysis to determine the mineralogical and morphological changes occurring due to carbonation. The reactants, products, and precipitation mechanisms were investigated to enhance understanding of the governing processes and allow better utilization of CKD …

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Carbon Dioxide Sequestration In Cement Kiln Dust Through Miner Carbonation, Deborah N. Huntzinger Jan 2006

Carbon Dioxide Sequestration In Cement Kiln Dust Through Miner Carbonation, Deborah N. Huntzinger

Dissertations, Master's Theses and Master's Reports - Open

The feasibility of carbon sequestration in cement kiln dust (CKD) was investigated in a series of batch and column experiments conducted under ambient temperature and pressure conditions. The significance of this work is the demonstration that alkaline wastes, such as CKD, are highly reactive with carbon dioxide (CO2). In the presence of water, CKD can sequester greater than 80% of its theoretical capacity for carbon without any amendments or modifications to the waste. Other mineral carbonation technologies for carbon sequestration rely on the use of mined mineral feedstocks as the source of oxides. The mining, pre-processing and reaction …

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Analyzing The Effects Of Vertical Acceleration And Deceleration In Multi-Phase, Debris-Flow Sediment-Column Experiments / By Christine Marie Williams., Christine Marie Williams Jan 2006

Analyzing The Effects Of Vertical Acceleration And Deceleration In Multi-Phase, Debris-Flow Sediment-Column Experiments / By Christine Marie Williams., Christine Marie Williams

Dissertations, Master's Theses and Master's Reports - Open

Water-saturated debris flows are among some of the most destructive mass movements. Their complex nature presents a challenge for quantitative description and modeling. In order to improve understanding of the dynamics of these flows, it is important to seek a simplified dynamic system underlying their behavior. Models currently in use to describe the motion of debris flows employ depth-averaged equations of motion, typically assuming negligible effects from vertical acceleration. However, in many cases debris flows experience significant vertical acceleration as they move across irregular surfaces, and it has been proposed that friction associated with vertical forces and liquefaction merit inclusion …

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Exploration Of Ground Penetrating Radar And Time Domain Reflectometry Methods For The Determination Of Pavement Dielectric Constant, Baron W. Colbert Jan 2006

Exploration Of Ground Penetrating Radar And Time Domain Reflectometry Methods For The Determination Of Pavement Dielectric Constant, Baron W. Colbert

Dissertations, Master's Theses and Master's Reports - Open

Traditionally, densities of newly built roadways are checked by direct sampling (cores) or by nuclear density gauge measurements. For roadway engineers, density of asphalt pavement surfaces is essential to determine pavement quality. Unfortunately, field measurements of density by direct sampling or by nuclear measurement are slow processes. Therefore, I have explored the use of rapidly-deployed ground penetrating radar (GPR) as an alternative means of determining pavement quality. The dielectric constant of pavement surface may be a substructure parameter that correlates with pavement density, and can be used as a proxy when density of asphalt is not known from nuclear or …

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Hands-On Oceanography. Settling Of Particles In Aquatic Environments Low Reynolds Numbers, Emmanuel Boss, Lee Karp-Boss, Peter A. Jumars Jan 2006

Hands-On Oceanography. Settling Of Particles In Aquatic Environments Low Reynolds Numbers, Emmanuel Boss, Lee Karp-Boss, Peter A. Jumars

Marine Sciences Faculty Scholarship

The purpose of this activity is to familiarize students with how a particle’s size, shape and orientation affects its settling at low Reynolds numbers. This activity can also be used to teach statistical skills (e.g., replication of measurements, propagation of error, type I vs. type II regressions).

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Potential Of Argo Drifters For Estimating Biological Production Within The Water Column, Seung Hyun Son, Emmanuel Boss, Jae Hoon Noh Jan 2006

Potential Of Argo Drifters For Estimating Biological Production Within The Water Column, Seung Hyun Son, Emmanuel Boss, Jae Hoon Noh

Marine Sciences Faculty Scholarship

Argo drifters provide information of the vertical structure in the water column and have a potential for the improvement of understanding phytoplankton primary production and biogeochemical cycles in combination with ocean color satellite data, which can obtain the horizontal distribution of phytoplankton biomass in the surface layer. Our examples show that using Argo drifters with satellite-measured horizontal distribution of phytoplankton biomass at the sea surface allow an improved understanding of the development of the spring bloom. The other possible uses of Argo drifter are discussed.

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Spanning Eulerian Subgraphs In Claw-Free Graphs, Zhi-Hong Chen, Hong-Jian Lai, Weiqi Luo, Yehomg Shao Jan 2006

Spanning Eulerian Subgraphs In Claw-Free Graphs, Zhi-Hong Chen, Hong-Jian Lai, Weiqi Luo, Yehomg Shao

Scholarship and Professional Work - LAS

A graph is claw-free if it has no induced K 1,3, subgraph. A graph is essential 4-edge-connected if removing at most three edges, the resulting graph has at most one component having edges. In this note, we show that every essential 4-edge-connected claw free graph has a spanning Eulerian subgraph with maximum degree at most 4.

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Emerging Chemicals And Analytical Methods (2006), Matthew C. Morley, Daniel D. Snow, Chad Cecrle, Patrick Denning, Lindsey Miller Jan 2006

Emerging Chemicals And Analytical Methods (2006), Matthew C. Morley, Daniel D. Snow, Chad Cecrle, Patrick Denning, Lindsey Miller

Nebraska Water Center: Faculty Publications

This review summarizes peer-reviewed literature related to analysis, occurrence, and fate of emerging chemical contaminants in the water environment. The review focuses on the following broad categories of emerging contaminants: pharmaceuticals and personal care products (PPCPs); endocrine disrupting compounds (EDCs), including hormones, surfactants, and plasticizers; and brominated flame retardants (BFRs). Although many of the cited articles refer to multiple types of contaminants (particularly hormones and pharmaceuticals), each article is summarized in only one section. Articles pertaining to specific treatment methods, risk assessments, or biological effects are not included in this review, and articles covering disinfection byproducts (DBPs), fluorinated compounds, and …

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A Metrics Tool For Multi-Language .Net Software Applications, Panos K. Linos, G. Mcgullogh, E. Maier Jan 2006

A Metrics Tool For Multi-Language .Net Software Applications, Panos K. Linos, G. Mcgullogh, E. Maier

Scholarship and Professional Work - LAS

The measurement of software metrics at the MSIL (Microsoft Intermediate Language) level can be as effective as measuring such metrics at the level of each individual language (e.g. VB, Java, C# etc.).

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Widespread Presence Of Naturally Occurring Perchlorate In High Plains Of Texas And New Mexico, Srinath Rajagopalan, Todd Anderson, Lynne Fahlquist, Ken Rainwater, Moira Ridley, W. Andrew Jackson Jan 2006

Widespread Presence Of Naturally Occurring Perchlorate In High Plains Of Texas And New Mexico, Srinath Rajagopalan, Todd Anderson, Lynne Fahlquist, Ken Rainwater, Moira Ridley, W. Andrew Jackson

United States Geological Survey: Staff Publications

Perchlorate (ClO4-) occurrence in groundwater has previously been linked to industrial releases and the historic use of Chilean nitrate fertilizers. However, recently a number of occurrences have been identified for which there is no obvious anthropogenic source. Groundwater from an area of 155 000 km2 in 56 counties in northwest Texas and eastern New Mexico is impacted by the presence of ClO4-. Concentrations were generally low (<4 ppb), although some areas are impacted by concentrations up to 200 ppb. ClO4- distribution is not related to well type (public water system, domestic, agricultural, or water-table monitoring) or aquifer (Ogallala, Edward Trinity High Plains, Edwards Trinity …

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Phytostabilization As A Remediation Alternative At Mining Sites, Dannis Neuman, Karl L. Ford Jan 2006

Phytostabilization As A Remediation Alternative At Mining Sites, Dannis Neuman, Karl L. Ford

United States Bureau of Land Management: Staff Publications

In the last 10 years, the Bureau of Land Management (BLM) has reclaimed a number of abandoned mine land (AML) sites, often by removing mine, mill, and smelter wastes and taking them to a repository. This removal process involves excavating, hauling, placing, and capping tens of thousands of cubic yards of material, which can be quite costly.
BLM is seeking more cost-effective methods for reclaiming AML sites. Phytostabilization is a promising alternative for accomplishing the goals of a removal at a tenth of the cost. Phytostabilization is an in situ technology involving soil amendments and metals-tolerant plants to establish a …

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A Report On The Potential Use Of Usda Forest Service Forest Inventory And Analysis Data By The Bureau Of Land Management, Bill Williams, Tracey Frescino, Larry Deblander, Sharon Woudenberg, Michael J. Wilson Jan 2006

A Report On The Potential Use Of Usda Forest Service Forest Inventory And Analysis Data By The Bureau Of Land Management, Bill Williams, Tracey Frescino, Larry Deblander, Sharon Woudenberg, Michael J. Wilson

United States Bureau of Land Management: Staff Publications

The Bureau of Land Management (BLM) does not have a consistent internal program or source of vegetation data to use for strategic level planning, such as in resource management plans. This technical note discusses and evaluates the potential of the USDA Forest Service Forest Inventory and Analysis (FIA) Program to assist the BLM in filling this data gap. The FIA program is the Forest Service’s national program for collecting and reporting information on status and trends in forested ecosystems. The FIA is considered here because it is the only standard, nationwide, systematic assessment of forest land available. The technical note …

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Evaluation Of The National Weather Service Operational Hydrologic Model And Forecasts For The American River Basin, Eylon Shamir, Theresa M. Carpenter, Peter Fickenscher, Konstantine P. Georgakakos Jan 2006

Evaluation Of The National Weather Service Operational Hydrologic Model And Forecasts For The American River Basin, Eylon Shamir, Theresa M. Carpenter, Peter Fickenscher, Konstantine P. Georgakakos

United States Department of Commerce: Staff Publications

This paper evaluates the National Weather Service operational hydrologic model and operational flow forecasts for several subbasins of the American River. The evaluation includes: (1) the quality of the 6-h operational flow forecasts with up to 5 days lead time; (2) the hydrologic model ability to reproduce observed mean daily flows; and (3) the reliability of the ensemble streamflow predictions of the hydrologic model to reproduce extremes of the monthly volume of full natural flow to Folsom Lake. The results indicate that the model represents the observed flow record well for sites and/or flow ranges unaffected by upstream regulation. Real …

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Effect Of Deposition Conditions On Mechanical Properties Of Low-Temperature Pecvd Silicon Nitride Films, H. Huang, K. J. Winchester, A. Suvorova, B. R. Lawn, Y. Liu, X. Z. Hu, J. M. Dell, L. Faraone Jan 2006

Effect Of Deposition Conditions On Mechanical Properties Of Low-Temperature Pecvd Silicon Nitride Films, H. Huang, K. J. Winchester, A. Suvorova, B. R. Lawn, Y. Liu, X. Z. Hu, J. M. Dell, L. Faraone

United States Department of Commerce: Staff Publications

The effect of deposition conditions on characteristic mechanical properties – elastic modulus and hardness – of low-temperature PECVD silicon nitrides is investigated using nanoindentation. It is found that increase in substrate temperature, increase in plasma power and decrease in chamber gas pressure all result in increases in elastic modulus and hardness. Strong correlations between the mechanical properties and film density are demonstrated. The silicon nitride density in turn is shown to be related to the chemical composition of the films, particularly the silicon/nitrogen ratio.

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Blue Whale (Balaenoptera Musculus) Sightings And Recordings South Of The Aleutian Islands, Shannon Rankin, Jay Barlow, Kathleen M. Stafford Jan 2006

Blue Whale (Balaenoptera Musculus) Sightings And Recordings South Of The Aleutian Islands, Shannon Rankin, Jay Barlow, Kathleen M. Stafford

United States Department of Commerce: Staff Publications

Blue whales have been sighted throughout the North Pacific Ocean (Mizroch et al. 1984), and were harvested around the Pacific Rim from Mexico to Japan (Fig. 1). The International Whaling Commission (IWC) currently recognizes only one stock of blue whales in the North Pacific (Donovan 1991); however, there may be up to five (reviewed in Stafford 2003). While past shipboard and aerial surveys in the Aleutian Island chain found no blue whales (Rice and Wolman 1982, Stewart et al. 1987), their contemporary presence in this area has been well documented by acoustic monitoring (Watkins et al. 2000, Stafford et al. …

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Change In Atmospheric Mineral Aerosols In Response To Climate: Last Glacial Period, Preindustrial, Modern, And Doubled Carbon Dioxide Climates, Natalie M. Mahowald, Daniel R. Muhs, Samuel Levis, Philip J. Rasch, Masaru Yoshioka, Charles S. Zender, Chao Luo Jan 2006

Change In Atmospheric Mineral Aerosols In Response To Climate: Last Glacial Period, Preindustrial, Modern, And Doubled Carbon Dioxide Climates, Natalie M. Mahowald, Daniel R. Muhs, Samuel Levis, Philip J. Rasch, Masaru Yoshioka, Charles S. Zender, Chao Luo

United States Geological Survey: Staff Publications

Desert dust simulations generated by the National Center for Atmospheric Research’s Community Climate System Model for the current climate are shown to be consistent with present day satellite and deposition data. The response of the dust cycle to last glacial maximum, preindustrial, modern, and doubled-carbon dioxide climates is analyzed. Only natural (non-land use related) dust sources are included in this simulation.

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Survival Estimates Of Western Gray Whales Eschrichtius Robustus Incorporating Individual Heterogeneity And Temporary Emigration, Amanda Bradford, Paul R. Wade, David Weller, Alexander M. Burdin, Yulia V. Ivashchenko, Grigory A. Tsidulko, Glenn R. Vanblaricom, Robert L. Brownell Jr. Jan 2006

Survival Estimates Of Western Gray Whales Eschrichtius Robustus Incorporating Individual Heterogeneity And Temporary Emigration, Amanda Bradford, Paul R. Wade, David Weller, Alexander M. Burdin, Yulia V. Ivashchenko, Grigory A. Tsidulko, Glenn R. Vanblaricom, Robert L. Brownell Jr.

United States Department of Commerce: Staff Publications

Gray whales Eschrichtius robustus exist as a 2 geographically and genetically distinct populations in the eastern and western North Pacific. Subjected to intensive commercial whaling during the 19th and 20th centuries, the western population presently numbers approximately 100 individuals and is regarded as one of the most endangered baleen whale populations in the world.

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Studies Of Beaked Whale Diving Behavior And Odontocete Stock Structure In Hawai‘I In March/April 2006, Robin W. Baird, Gregory S. Schorr, Daniel L. Webster, Daniel J. Mcsweeney, Sabre D. Mahaffy Jan 2006

Studies Of Beaked Whale Diving Behavior And Odontocete Stock Structure In Hawai‘I In March/April 2006, Robin W. Baird, Gregory S. Schorr, Daniel L. Webster, Daniel J. Mcsweeney, Sabre D. Mahaffy

United States Department of Commerce: Staff Publications

Small-boat surveys were undertaken in March/April 2006 off the west side of the island of Hawai‘i for the purposes of obtaining dive data from Blainville’s (Mesoplodon densirostris) and Cuvier’s (Ziphius cavirostris) beaked whales, as well as collecting biopsy samples and photo-identification of these and other species of odontocetes for studies of stock structure and residency patterns. There were 157 sightings of 13 species of odontocetes in 4,264 km of effort, with 120 genetic samples from seven species and over 29,000 photographs from 13 species obtained. Photographic matching to existing catalogs is currently underway for eight species. …

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Cetacean Abundance In Hawaiian Waters Estimated From A Summer/Fall Survey In 2002, Jay Barlow Jan 2006

Cetacean Abundance In Hawaiian Waters Estimated From A Summer/Fall Survey In 2002, Jay Barlow

United States Department of Commerce: Staff Publications

Cetacean abundance is estimated for the U.S. Exclusive Economic Zone (EEZ) around the Hawaiian Islands based on a ship line-transect survey from August to November, 2002. Sighting detection functions are estimated from this and other NOAA research surveys from 1986 to 2002 using a new, multiple-covariate approach. Twenty-four species were seen on this survey, including two species (Fraser’s dolphin [Lagenodelphis hosei] and sei whale [Balaenoptera borealis]) that had not been previously documented to occur in Hawaiian waters. The most abundant large whales are sperm whales (Physeter macrocephalus) and Bryde’s whales (Balaenoptera edeni). The most …

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Integrated View And Comparison Of Alignment Semantics, Pascal Hitzler, Jerome Euzenat, Markus Krotzsch, Luciano Serafini, Heiner Stuckenschmidt, Holger Wache, Antoine Zimmermann Jan 2006

Integrated View And Comparison Of Alignment Semantics, Pascal Hitzler, Jerome Euzenat, Markus Krotzsch, Luciano Serafini, Heiner Stuckenschmidt, Holger Wache, Antoine Zimmermann

Computer Science and Engineering Faculty Publications

We take a general perspective on alignment in order to develop common theoretical foundations for the subject. The deliverable comprises a comparative study of different mapping languages by means of distributed first-order logic, and a study on category-theoretical modelling of alignment and merging by means of pushout-combinations.

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Why Is The Number Of Dna Bases 4?, Bo Deng Jan 2006

Why Is The Number Of Dna Bases 4?, Bo Deng

Department of Mathematics: Faculty Publications

In this paper we construct a mathematical model for DNA replication based on Shannon’s mathematical theory for communication. We treatDNAreplication as a communication channel. We show that the mean replication rate is maximal with four nucleotide bases under the primary assumption that the pairing time of the G–C bases is between 1.65 and 3 times the pairing time of the A–T bases.

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Decentralized Convex-Type Equilibrium In Nonconvex Models Of Welfare Economics Via Nonlinear Prices, Boris S. Mordukhovich Jan 2006

Decentralized Convex-Type Equilibrium In Nonconvex Models Of Welfare Economics Via Nonlinear Prices, Boris S. Mordukhovich

Mathematics Research Reports

The paper is devoted to applications of modern tools of variational analysis to equilibrium models of welfare economics involving nonconvex economies with infinite-dimensional commodity spaces. The main results relate to generalized/ extended second welfare theorems ensuring an equilibrium price support at Pareto optimal allocations. Based on advanced tools of generalized differentiation, we establish refined results of this type with the novel usage of nonlinear prices at the three types to optimal allocations: weak Pareto, Pareto, and strong Pareto. The usage of nonlinear (vs. standard linear) prices allow us to decentralized price equilibria in fully nonconvex models similarly to linear prices …

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Magnetic Memory And Current Amplification Devices Using Moving Domain Walls, Stewart E. Barnes, J. Ieda, S. Maekawa Jan 2006

Magnetic Memory And Current Amplification Devices Using Moving Domain Walls, Stewart E. Barnes, J. Ieda, S. Maekawa

Physics Articles and Papers

A moving magnetic domain wall produces an electromotive force (emf). It is therefore possible to read the state of a magnetic memory device via the emf it produces when subjected to an interrogation pulse. It is also possible to amplify currents in pulse circuits, opening up the possibility of all magnetic logic circuits.

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Comment On “Theory Of Current-Driven Domain Wall Motion: Spin Transfer Versus Momentum Transfer”, S. E. Barnes Jan 2006

Comment On “Theory Of Current-Driven Domain Wall Motion: Spin Transfer Versus Momentum Transfer”, S. E. Barnes

Physics Articles and Papers

A Comment on the Letter by Gen Tatara and Hiroshi Kohno, Phys. Rev. Lett. 92 086601 (2004). The authors of the Letter offer a Reply.

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Near-Infrared And The Inner Regions Of Protoplanetary Disks, Dejan Vinković, Željko Ivezić, Tomislav Jurkić, Moshe Elitzur Jan 2006

Near-Infrared And The Inner Regions Of Protoplanetary Disks, Dejan Vinković, Željko Ivezić, Tomislav Jurkić, Moshe Elitzur

Physics and Astronomy Faculty Publications

We examine the “puffed-up inner disk” model proposed by Dullemond, Dominik, & Natta for explaining the near-IR excess radiation from Herbig Ae/Be stars. Detailed model computations show that the observed near-IR excess requires more hot dust than is contained in the puffed-up disk rim. The rim can produce the observed near-IR excess only if its dust has perfectly gray opacity, but such dust is in conflict with the observed 10 μm spectral feature. We find that a compact (~10 AU), tenuous (τV ≲ 0.4), dusty halo around the disk inner regions contains enough dust to readily explain …

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On-Farm Field Research: Setting Up A Valid Comparison, John H. Grove Jan 2006

On-Farm Field Research: Setting Up A Valid Comparison, John H. Grove

Soil Science News and Views

Producers now have the tools (grain carts with load cells, yield monitors, GPS) to do on-farm field research. Additionally, growers are being made aware of more and more products/management options that they might use. One might read farm magazines, talk to neighbors, attend extension and industry presentations, but still wonder whether a particular recommendation would be of benefit. So the question remains. How would this (product, change in management) work on the land that I farm? Tools plus uncertainty equals motivation for an on-farm comparison.

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The Corn Belt Multi-State Corn Nitrogen Rate Calculator: Not Reliable For Kentucky Corn Producers, John H. Grove, Gregory J. Schwab Jan 2006

The Corn Belt Multi-State Corn Nitrogen Rate Calculator: Not Reliable For Kentucky Corn Producers, John H. Grove, Gregory J. Schwab

Soil Science News and Views

Because of the rising price of nitrogen (N) fertilizer, university personnel across the country are in the process of fine tuning N recommendations for com. Historically, each state has had different N recommendations based on research results obtained in different production systems and growing environments across each state. Some states in the Com Belt have used a yield potential (yield goal) approach to N recommendations. The expected yield is multiplied by a factor (usually 1.2) and then N credits for previous crop, manure, etc. are subtracted. One problem with this method is that as com yields increase N recommendations also …

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On-Farm Field Research: Replicating Your Valid Comparison, John H. Grove Jan 2006

On-Farm Field Research: Replicating Your Valid Comparison, John H. Grove

Soil Science News and Views

On-farm research is motivated by a desire to learn more about a product/practice/system on land you manage. You may now have the tools (yield monitor, weighing grain cart, etc.) to accomplish on-farm research that generates information you can use in management decision-making. Your on-farm research should start with the design of a ''valid comparison", according to your research objective (Soil Science News & Views 26:01).

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