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Articles 2161 - 2190 of 4602

Full-Text Articles in Physical Sciences and Mathematics

Monitoring Relative Abundance Of American Shad In Virginia Rivers 2007 Annual Report, John E. Olney, Brian Watkins Apr 2008

Monitoring Relative Abundance Of American Shad In Virginia Rivers 2007 Annual Report, John E. Olney, Brian Watkins

Reports

Concern about the decline in landings of American shad (Alosa sapidissima) along the Atlantic coast prompted the development of an interstate fisheries management plan (FMP) under the auspices of the Atlantic States Marine Fisheries Management Program (ASMFC 1999). Legislation enables imposition of federal sanctions on fishing in those states that fail to comply with the FMP. To be in compliance, coastal states are required to implement and maintain fishery-dependent and fishery-independent monitoring programs as specified by the FMP. For Virginia, these requirements include spawning stock assessments, the collection of biological data on the spawning run (e.g., age-structure, sex ratio, and …


Semiclassical Theory Of The Structure Of The Hydrogen Spectrum In Near-Perpendicular Electric And Magnetic Fields: Derivations And Formulas For Einstein-Brillouin-Keller-Maslov Quantization And Description Of Monodromy, Christopher Robert Schleif, John B. Delos Apr 2008

Semiclassical Theory Of The Structure Of The Hydrogen Spectrum In Near-Perpendicular Electric And Magnetic Fields: Derivations And Formulas For Einstein-Brillouin-Keller-Maslov Quantization And Description Of Monodromy, Christopher Robert Schleif, John B. Delos

Arts & Sciences Articles

In a previous paper [Schleif and Delos, Phys. Rev. A 76, 013404 (2007)] we described the spectrum of hydrogen atoms in near-perpendicular electric and magnetic fields. We displayed a number of previously unrecognized structures in the spectrum, most of which are connected with a classical phenomenon called “nontrivial monodromy of action and angle variables in a Hamiltonian system,” or simply “monodromy.” In that paper, we presented only the results, giving predictions of what to look for in various ranges of electric and magnetic fields. Here we present the underlying theory. Starting from Kepler action and angle variables, we give a …


Virginia Wetlands Report Vol. 23, No. 1, Virginia Institute Of Marine Science, Center For Coastal Resources Management Mar 2008

Virginia Wetlands Report Vol. 23, No. 1, Virginia Institute Of Marine Science, Center For Coastal Resources Management

Virginia Wetlands Reports

On the road with CCRM


Eastern Us Continental Shelf Carbon Budget Integrating Models, Data Assimilation, And Analysis, E Hofmann, Jn Droun, Mam Friedrichs, Et Al Mar 2008

Eastern Us Continental Shelf Carbon Budget Integrating Models, Data Assimilation, And Analysis, E Hofmann, Jn Droun, Mam Friedrichs, Et Al

VIMS Articles

No abstract provided.


Delaware Shoreline Inventory: Appoquinimink River, Blackbird Creek, St. Jones River, Marcia Berman, Harry Berquist, Carl Hershner, Sharon Killeen, Tamia Rudnicky, Karen Reay, David Weiss Mar 2008

Delaware Shoreline Inventory: Appoquinimink River, Blackbird Creek, St. Jones River, Marcia Berman, Harry Berquist, Carl Hershner, Sharon Killeen, Tamia Rudnicky, Karen Reay, David Weiss

Reports

This shoreline inventory is developed as a tool for assessing conditions along primary shoreline in three watersheds that discharge into Delaware Bay. Field data were collected between September 11-13, 2007. Conditions are reported for three zones within the immediate riparian river area: riparian land use, bank and buffers, and the shoreline. A series of maps, tabular data, and GIS files are posted to a website and available electronically to serve as a resource to all managers and planners within the three watersheds. The survey provides a baseline to which future conditions can be compared and tracked through time.

Access report …


New Point Comfort Lighthouse Mathews, Virginia Site Assessment Plan, C. Scott Hardaway Jr., Donna A. Milligan, Kevin P. O'Brien, Christine A. Wilcox Feb 2008

New Point Comfort Lighthouse Mathews, Virginia Site Assessment Plan, C. Scott Hardaway Jr., Donna A. Milligan, Kevin P. O'Brien, Christine A. Wilcox

Reports

New Point Comfort is located at the southern tip of Mathews County (Figure 1) between Chesapeake and Mobjack Bays. The New Point Comfort Lighthouse itself is on an island (Figure 2) that was once attached to the mainland but is now almost 0.6 miles from the mainland and only 0.33 acres in area above mean low water. Previous studies have highlighted the problems which contribute to the instability of the island. McKay (2003) listed these factors which may allow continued erosion and potential damage up to and including the base of the lighthouse itself: rise in sea level, low base …


Six Fish And 600,000 Thirsty Folks—A Fishing Moratorium On American Shad Thwarts A Controversial Municipal Reservoir Project In Virginia, Usa, J. E. Olney, Donna M. Bilkovic, Carl Hershner, Lyle M. Varnell, Harry V. Wang, Roger L. Mann Jan 2008

Six Fish And 600,000 Thirsty Folks—A Fishing Moratorium On American Shad Thwarts A Controversial Municipal Reservoir Project In Virginia, Usa, J. E. Olney, Donna M. Bilkovic, Carl Hershner, Lyle M. Varnell, Harry V. Wang, Roger L. Mann

VIMS Books and Book Chapters

Moratoria on fishing directly impact fishers, distributors and marketers of product and can have serious socio-economic implications. Moratoria can impact communities but usually populations closely linked to the banned activity. In an unprecedented example, a moratorium on fishing in Virginia has directly impacted a nonfishing citizenry by thwarting plans for a public utility. In May 2003, a panel empowered to regulate marine resources denied permission to withdraw raw water from a pristine freshwater river, the Mattaponi. The controversial action spoiled a multi-million dollar plan to establish the King William Reservoir, a water source considered essential to future growth and development …


A Comparison Of Structural And Nonstructural Methods For Erosion Control And Providing Habitat In Virginia Salt Marshes, Karen A. Duhring Jan 2008

A Comparison Of Structural And Nonstructural Methods For Erosion Control And Providing Habitat In Virginia Salt Marshes, Karen A. Duhring

VIMS Books and Book Chapters

Shoreline stabilization methods that emphasize the use of tidal marshes and riparian vegetation are encouraged as a baseline defense for tidal shoreline erosion in Virginia. The effectiveness of three of these methods in preventing erosion and providing habitat was evaluated, including marsh stabilization structures (marsh toe revetments and sills), planted tidal marshes, and bank grading. This evaluation includes results from a recent field survey of 36 tidal marsh stabilization structures, permitting records, and other monitoring data. Marsh structures effectively reduced erosion of fringing and embayed marshes but were not as effective for gradually disappearing spit marshes. Adverse impacts of restricted …


2008 Chesapeake Bay Bridge Tunnel Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans Jan 2008

2008 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.


2008 Hampton Roads Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans Jan 2008

2008 Hampton Roads Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans

Miscellaneous

These calendars are produced monthly using David Evans' Tidecal.


2008 Gloucester Point Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans Jan 2008

2008 Gloucester Point Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans

Miscellaneous

These calendars are produced monthly using David Evans' Tidecal.


2008 Wachapreague Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans Jan 2008

2008 Wachapreague Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans

Miscellaneous

These calendars are produced monthly using David Evans' Tidecal.


Technical Note: Molecular Characterization Of Aerosol-Derived Water Soluble Organic Carbon Using Ultrahigh Resolution Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, As Wosniak, Je Bauer, Rl Sleighter, Rm Dickhut, Pg Hatcher Jan 2008

Technical Note: Molecular Characterization Of Aerosol-Derived Water Soluble Organic Carbon Using Ultrahigh Resolution Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, As Wosniak, Je Bauer, Rl Sleighter, Rm Dickhut, Pg Hatcher

VIMS Articles

Despite the acknowledged relevance of aerosol-derived water-soluble organic carbon (WSOC) to climate and biogeochemical cycling, characterization of aerosol WSOC has been limited. Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) was utilized in this study to provide detailed molecular level characterization of the hi(,h molecular weight (HMW; m/z>223) component of aerosol-derived WSOC collected from rural sites in Virginia and New York, USA. More than 3000 peaks were detected by ESI FT-ICR MS within a m/z range of 223-600 for each sample. Approximately 86% (Virginia) and 78% (New York) of these peaks were assigned molecular formulas …


Bis{L-2,20-[1,10-(Ethane-1,2-Diyldinitrilo)- Diethylidyne]Diphenolato}Bis[(Benzoatojo)Manganese(Iii)] Dihydrate, V. S. Thampidas, T. Radhakrishnan, Robert D. Pike Jan 2008

Bis{L-2,20-[1,10-(Ethane-1,2-Diyldinitrilo)- Diethylidyne]Diphenolato}Bis[(Benzoatojo)Manganese(Iii)] Dihydrate, V. S. Thampidas, T. Radhakrishnan, Robert D. Pike

Arts & Sciences Articles

The title compound, [Mn2(C18H18N2O2)2Cl2], was synthesized by the reaction between manganese(II) o-chloro­benzoate and the Schiff base generated in situ by the condensation of ethane-1,2-diamine and o-hydroxy­acetophenone. The centrosymmetric dimer contains two Jahn-Teller-distorted mangan­ese(III) ions, each in an octa­hedral geometry, connected through two phen­oxy bridges from two ligands.


Poly[L-2-Aminopyrazine-J2 N1 :N4 - L-Cyanido-Copper(I)]: A Three-Dimensional Network From Laboratory Powder Diffraction Data, Silvina Pagola, Robert D. Pike, Kathryn Dekrafft, Tristan A. Tronic Jan 2008

Poly[L-2-Aminopyrazine-J2 N1 :N4 - L-Cyanido-Copper(I)]: A Three-Dimensional Network From Laboratory Powder Diffraction Data, Silvina Pagola, Robert D. Pike, Kathryn Dekrafft, Tristan A. Tronic

Arts & Sciences Articles

In the title compound, [Cu(CN)(C4H5N3)]n or [Cu(-CN)(-PyzNH2)]n (PyzNH2 is 2-amino­pyrazine), the CuI center is tetra­hedrally coordinated by two cyanide and two PyzNH2 ligands. The CuI-cyano links give rise to [Cu-CN] chains running along the c axis, which are bridged by bidentate PyzNH2 ligands. The three-dimensional framework can be described as being formed by two inter­penetrated three-dimensional honeycomb-like networks, both made of 26-membered rings of composition [Cu6(-CN)2(-PyzNH2)4].


Parallel Unstructured Grid Generation For Complex Real-World Aerodynamic Simulations, George Zagaris Jan 2008

Parallel Unstructured Grid Generation For Complex Real-World Aerodynamic Simulations, George Zagaris

Dissertations, Theses, and Masters Projects

No abstract provided.


Mesopelagic Zooplankton Feeding Ecology And Effects On Particle Repackaging And Carbon Transport In The Subtropical And Subarctic North Pacific Ocean, Stephanie E. Wilson Jan 2008

Mesopelagic Zooplankton Feeding Ecology And Effects On Particle Repackaging And Carbon Transport In The Subtropical And Subarctic North Pacific Ocean, Stephanie E. Wilson

Dissertations, Theses, and Masters Projects

Differences in zooplankton community structure and diet within the mesopelagic zone (base of euphotic zone to 1000 m) play a key role in affecting the efficiency by which organic matter is exported to depth, but how the structure of mesopelagic food webs change with depth or location is poorly known. I examined how mesopelagic zooplankton affect particle export in an oligotrophic (Hawaii Ocean Time-series site ALOHA) compared to a mesotrophic (Japanese time series site K2) open-ocean system. In the first part of the study, I investigated how fecal pellet characteristics change with depth in order to quantify the extent of …


Novel Use Of A Natural Isotope Signature To Track Recruitment And Evaluate Age Determination Methods For The 2002 Year Class Of American Shad In The York River, Sally A. Upton Jan 2008

Novel Use Of A Natural Isotope Signature To Track Recruitment And Evaluate Age Determination Methods For The 2002 Year Class Of American Shad In The York River, Sally A. Upton

Dissertations, Theses, and Masters Projects

No abstract provided.


Summary Tables: New Kent County, Virginia Shoreline Inventory Report, Marcia Berman, Harry Berquist, Sharon Killeen, Tamia Rudnicky, Daniel E. Schatt, David Weiss, Karen Reay Jan 2008

Summary Tables: New Kent County, Virginia Shoreline Inventory Report, Marcia Berman, Harry Berquist, Sharon Killeen, Tamia Rudnicky, Daniel E. Schatt, David Weiss, Karen Reay

Reports

The Shoreline Inventory Summary Tables quantify observed conditions based on river systems, such as the combined length of linear features (e.g. shoreline miles surveyed, miles of bulkhead and revetment), the total number of point features (e.g. docks, boathouses, boat ramps) & total acres of polygon features (tidal marshes).


Overview Of Living Shoreline Design Options For Erosion Protection On Tidal Shorelines, Karen A. Duhring Jan 2008

Overview Of Living Shoreline Design Options For Erosion Protection On Tidal Shorelines, Karen A. Duhring

VIMS Books and Book Chapters

The term “living shoreline” was recently associated with particular types of shoreline stabilization methods that emphasize the use of natural habitat features such as deeply rooted riparian vegetation, vegetated wetlands, and sand beaches. This overview of living shoreline design options for tidal tributaries describes six nonstructural and four “hybrid” or structural methods for erosion protection. Structures are included with living shoreline design options to make habitat restoration or creation possible without substantial impacts to tidal exchange or habitat functions. The use and effectiveness of other methods not included in this summary are still under investigation, such as oyster shell reefs …


Current Understanding Of The Effectiveness Of Nonstructural And Marsh Sill Approaches, Bhaskaran Subramanian, Gene Slear, Kevin M. Smith, Karen A. Duhring Jan 2008

Current Understanding Of The Effectiveness Of Nonstructural And Marsh Sill Approaches, Bhaskaran Subramanian, Gene Slear, Kevin M. Smith, Karen A. Duhring

VIMS Books and Book Chapters

A panel session at the Living Shorelines Summit in Williamsburg, Virginia was dedicated to the current understanding of the effectiveness of nonstructural erosion protection methods and marsh sills. Four panelists described their professional experience with either design and construction or monitoring of projects in tidal waters of Maryland and Virginia, including marsh edge stabilization (marsh toe revetments), marsh sills with sand fill, and planted marshes. Their collective experience revealed that planted tidal marshes and supporting structures can be effective alternatives to revetments and bulkheads. Site-specific engineering is required to ensure they provide functional ecological benefits, particularly in medium and high …


Crystal Structure Of Di-Iso-Butylammonium Thiolactatotriphenylstannate, Olaniran Atchade, Xueqing Song, Robert Pike, George Eng Jan 2008

Crystal Structure Of Di-Iso-Butylammonium Thiolactatotriphenylstannate, Olaniran Atchade, Xueqing Song, Robert Pike, George Eng

Arts & Sciences Articles

The title compounds, [(iso-C4H9)2NH2][SnPh3(O2CCH(CH3)S)], crystallized in a monoclinic space group P21/n with the following cell parameters: a = 9.8537(2)Å, b = 16.7775(3)Å, c = 17.5845(3)Å, β = 103.7740(10)°, V = 2823.48(9)Å3, Z = 4 and Dx = 1.375 Mg m-3. The structure was refined to a final R value of 0.0222 for 5042 reflections [I > 2σ(I)]. The structure of the complex is ionic consisting of an anionic triphenyltin moiety and a cationic di-iso-butylammonium portion. In addition, a hydrogen bonding network between the cations and anions was observed.


Aqua {2,2-[Ethane-1,2-Diylbis(Nitrilomethylidyne)]Diphenolato}(3-Nitrobenzoato)Manganese(Iii), V. S. Thampidas, T. Radhakrishnan, Robert D. Pike Jan 2008

Aqua {2,2-[Ethane-1,2-Diylbis(Nitrilomethylidyne)]Diphenolato}(3-Nitrobenzoato)Manganese(Iii), V. S. Thampidas, T. Radhakrishnan, Robert D. Pike

Arts & Sciences Articles

The title compound, [Mn(C16H14N2O2)(C7H4NO4)(H2O)], is a Jahn-Teller-distorted manganese(III) monomer with an octa­hedral geometry. The tetra­dentate Schiff base accommodates the MnIII ion at the centre of a nearly planar square. The axial positions are occupied by a monodentate carboxyl­ate group and a water mol­ecule. Adjacent monomers inter­act through hydrogen bonding between the noncoordinated C=O group of the carboxyl­ate and the coordinated water mol­ecule to produce chains extending parallel to the b axis.


2,2,3,30-Tetraphenyl-7,70-Biquinoxaline, Eric E. Dueno, Ricky J. Paul, Ralph N. Salvatore, Robert D. Pike Jan 2008

2,2,3,30-Tetraphenyl-7,70-Biquinoxaline, Eric E. Dueno, Ricky J. Paul, Ralph N. Salvatore, Robert D. Pike

Arts & Sciences Articles

In the crystal structure of the title compound, C40H26N4, mol­ecules reside on crystallographic centers of inversion and are linked via C-HN inter­actions about inversion centers into one-dimensional chains: longer C-H(arene) inter­actions complete the inter­molecular inter­actions.


Controls On Continental Shelf Stratigraphy: Waiapu River, New Zealand, Heidi M. Wadman Jan 2008

Controls On Continental Shelf Stratigraphy: Waiapu River, New Zealand, Heidi M. Wadman

Dissertations, Theses, and Masters Projects

A quantitative understanding of the processes controlling sediment transport and deposition across the land/sea interface is crucial to linking terrestrial and marine environments and understanding the formation of marine stratigraphy. The nature and distribution of terrestrial-derived sediment preserved in shelf stratigraphy in turn provides insight into the complex linkages inherent in source-to-sink sediment dynamics. Located inboard of an actively subducting plate boundary and characterized by one of the highest sediment yields in the world, the open-shelf setting off of the Waiapu River in New Zealand presents an excellent location to improve our understanding of the factors controlling the formation of …


Topics In Mode Conversion Theory And The Group Theoretical Foundations Of Path Integrals, Andrew Stephen Richardson Jan 2008

Topics In Mode Conversion Theory And The Group Theoretical Foundations Of Path Integrals, Andrew Stephen Richardson

Dissertations, Theses, and Masters Projects

This dissertation reports research about the phase space perspective for solving wave problems, with particular emphasis on the phenomenon of mode conversion in multicomponent wave systems, and the mathematics which underlie the phase space perspective. Part I of this dissertation gives a review of the phase space theory of resonant mode conversion. We describe how the WKB approximation is related to geometrical structures in phase space, and how in particular ray-tracing algorithms can be used to construct the WKB solution. We further review how to analyze the phenomena of mode conversion from the phase space perspective. By making an expansion …


The Semiclassical Description Of The Energy Spectrum Of Hydrogen In Near-Perpendicular Fields, Christopher Robert Schleif Jan 2008

The Semiclassical Description Of The Energy Spectrum Of Hydrogen In Near-Perpendicular Fields, Christopher Robert Schleif

Dissertations, Theses, and Masters Projects

We examine the energy spectrum of hydrogen in weak near-perpendicular electric and magnetic fields using quantum computations and semiclassical analysis. The structure of the quantum spectrum is displayed in a lattice constructed by plotting the difference between total energy and first order energy versus first order energy, for all states of a given principal quantum number n. For some field parameters, the lattice structure is not regular, but has a lattice defect structure which may be characterized by the transport of lattice vectors. We find that in near-perpendicular fields the structure of the spectrum is divided into six distinct parameter …


Assessing Stakeholder Preferences For Chesapeake Bay Restoration Options : A Stated Preference Discrete Choice-Based Assessment, Rob Hicks, James Kirkley, Kenneth Mcconnell, Winifred Ryan, Tara Scott, Ivar Strand Jan 2008

Assessing Stakeholder Preferences For Chesapeake Bay Restoration Options : A Stated Preference Discrete Choice-Based Assessment, Rob Hicks, James Kirkley, Kenneth Mcconnell, Winifred Ryan, Tara Scott, Ivar Strand

Reports

Chesapeake 2000 or C2K is a multi-jurisdictional agreement between the states of Virginia, Maryland, Pennsylvania, the District of Columbia, the Chesapeake Bay Commission and the U.S. Environmental Protection Agency, representing the federal government, to restore the health of the Chesapeake Bay’s ecosystem. This agreement commits the participants to achieve five major restoration goals, 22 sub-objectives or categories, and 102 specific commitments or restoration activities. The five major goals are the following: (1) restore and protect natural living resources; (2) restore and protect vital habitat; (3) restore and protect water quality; (4) promote sound land use; and (5) promote stewardship and …


Gis Data: New Kent County, Virginia Shoreline Inventory Report, Marcia Berman, Harry Berquist, Sharon Killeen, Karinna Nunez, Tamia Rudnicky, Daniel E. Schatt, David Weiss, Karen Reay Jan 2008

Gis Data: New Kent County, Virginia Shoreline Inventory Report, Marcia Berman, Harry Berquist, Sharon Killeen, Karinna Nunez, Tamia Rudnicky, Daniel E. Schatt, David Weiss, Karen Reay

Data

The data inventory developed for the Shoreline Inventory is based on a three‑tiered shoreline assessment approach. In most cases this assessment characterizes conditions that can be observed from a small boat navigating along the shoreline. The three tiered shoreline assessment approach divides the shorezone into three regions: 1) the immediate riparian zone, evaluated for land use; 2) the bank, evaluated for height, stability, cover and natural protection; and 3) the shoreline, describing the presence of shoreline structures for shore protection and recreational purposes. Hand-held GPS units are used to log features observed in the field.

Three GIS coverages are developed …


Community Dynamics In Submersed Aquatic Vegetation: Intermediate Consumers As Mediators Of Environmental Change, James G. Douglass Jan 2008

Community Dynamics In Submersed Aquatic Vegetation: Intermediate Consumers As Mediators Of Environmental Change, James G. Douglass

Dissertations, Theses, and Masters Projects

Natural ecosystems are strongly affected by changes in resource supply (bottom-up forces) and by changes in upper trophic levels (top-down forces). The extent to which these processes impact a system depends largely on the responses of organisms at middle trophic levels. In seagrass beds, a group of mid-level consumers known as mesograzers form a critical link in the chain of impact, connecting seagrass and epiphytic algae with predatory fishes and crustaceans. I observed dramatic seasonal and interannual changes in mesograzer abundance and species composition in eelgrass (Zostera marina) beds of lower Chesapeake Bay, Virginia, and endeavored to explain the top-down …