Independent trapping and manipulation of microparticles using dexterous acoustic tweezers

An electronically controlled acoustic tweezer was used to demonstrate two acoustic manipulation phenomena: superposition of Bessel functions to allow independent manipulation of multiple particles and the use of higher-order Bessel functions to trap particles in larger regions than is possible with first-order traps. The acoustic tweezers consist of a circular 64-element ultrasonic array operating at 2.35MHz which generates ultrasonic pressure fields in a millimeter-scale fluid-filled chamber. The manipulation capabilities were demonstrated experimentally with 45 and 90-lm-diameter polystyrene spheres. These capabilities bring the dexterity of acoustic tweezers substantially closer to that of optical tweezers

Dune Evolution Accomack County, Virginia Chesapeake Bay Shorelines

Shoreline evolution is the change in shore position through time. In fact, it is the material resistance of the coastal geologic underpinnings against the impinging hydrodynamic (and aerodynamic) forces. Along the shores of Chesapeake Bay, it is a process-response system. The processes at work include winds, waves, tides and currents, which shape and modify coastlines by eroding, transporting and depositing sediments. The shore line is commonly plotted and measured to provide a rate of change but it is as important to understand the geomorphic patterns of change. Shore analysis provides the basis to know how a particular coast has changed through time and how it might proceed in the future. The purpose of this report is to document how the dunes on Chesapeake Bay shores of Accomack (Figure 1) have evolved since 1938. Aerial imagery was taken for most of the Bay region beginning that year, and it is this imagery that allows one to assess the geomorphic nature of shore change. Aerial imagery shows how the coast has changed, how beaches, dunes, bars, and spits have grown or decayed, how barriers have breached, how inlets have changed course, and how one shore type has displaced another or has not changed at all. Shore change is a natural process but, quite often, the impacts of man through shore hardening or inlet stabilization come to dominate a given shore reach. Most of the change in shore positions where dunes occur will be quantified in this report. Others, particularly very irregular coasts, around inlets, and other complicated areas will be subject to interpretation

Shoreline Evolution Chesapeake Bay and Piankatank River Shorelines Mathews County, VA

Shoreline evolution is the change in shore position through time. In fact, it is the material resistance of the coastal geologic underpinnings against the impinging hydrodynamic (and aerodynamic) forces. Along the shores of Chesapeake Bay, it is a process-response system. The processes at work include winds, waves, tides and currents, which shape and modify coastlines by eroding, transporting and depositing sediments. The shore line is commonly plotted and measured to provide a rate of change but it is as important to understand the geomorphic patterns of change. Shore analysis provides the basis to know how a particular coast has changed through time and how it might proceed in the future. The purpose of this report is to document how the Bay shore of Mathews (Figure 1) has evolved since 1937. Aerial imagery was taken for most of the Bay region beginning that year, and it is this imagery that allows one to assess the geomorphic nature of shore change. Aerial imagery shows how the coast has changed, how beaches, dunes, bars, and spits have grown or decayed, how barriers have breached, how inlets have changed course, and how one shore type has displaced another or has not changed at all. Shore change is a natural process but, quite often, the impacts of man through shore hardening or inlet stabilization come to dominate a given shore reach. Most of the change in shore positions will be quantified in this report. Others, particularly very irregular coasts, around inlets, and other complicated areas will be subject to interpretation

Shoreline evolution, Chesapeake Bay and Potomac River shorelines, Northumberland County, Virginia

Shoreline evolution is the change in shore position through time. In fact, it is the material resistance of the coastal geologic underpinnings against the impinging hydrodynamic (and aerodynamic) forces. Along the shores of Chesapeake Bay, it is a process-response system. The processes at work include winds, waves, tides and currents, which shape and modify coastlines by eroding, transporting and depositing sediments. The shoreline is commonly plotted and measured to provide a rate of change but it is as important to understand the geomorphic patterns of change. Shore analysis provides the basis to know how a particular coast has changed through time and how it might proceed in the future. The purpose of this report is to document how dunes on the Potomac River and Chesapeake Bay shores of Northumberland (Figure 1) has evolved since 1937. Aerial imagery was taken for most of the Bay region beginning that year, and it is this imagery that allows one to assess the geomorphic nature of shore change. Aerial imagery shows how the coast has changed, how beaches, dunes, bars, and spits have grown or decayed,how barriers have breached, how inlets have changed course, and how one shore type has displaced another or has not changed at all. Shore change is a natural process but, quite often, the impacts of man through shore hardening or inlet stabilization come to dominate a given shore reach. Most of the change in shore positions will be quantified in this report. Others, particularly very irregular coasts, around inlets, and other complicated areas will be subject to interpretation

Yorktown Beach 2003-2005, with Hurricane Isabel Impacts

The Yorktown Public Beach is located on the south side of the York River at Yorktown, Virginia (Figure 1). It is approximately 1,200 feet in length. Historically, the beach was a product of erosion of nearby sandy upland banks and the littoral transport system. Over the years, the beaches along the waterfront began to narrow as the natural sediment supply was depleted by hardening of the updrift shorelines and were easily overwashed in storms and had continually eroded. Since 1978, various projects have taken place along Yorktown’s shoreline in order to abate erosion, provide a recreational beach, and minimize damage to the upland during storms. Since 1994, seven breakwaters with beach fill have been installed along the shoreline. These structures have created a stable beach planform designed to withstand a 50-yr storm event. In September 2003, Hurricane Isabel impacted the Yorktown Beach and backshore. This event, with its high storm surge, caused considerable damage to the buildings along Water St. However, the rock breakwater units sustained no damage, and the beach required only the placement of 3,500 cubic yards of sand to be brought back to it’s pre-storm condition

Northern Neck Regional Shallow Draft Channel Dredging Plan: Initial Phase

The purpose of this project is to develop a regional dredging program for the localities of the Northern Neck. This report encompasses Phase 1 of the project, which included creating a database of waterbodies in Lancaster, Northumberland, Richmond, and Westmoreland Counties and the Town of Colonial Beach along the Potomac and Rappahannock Rivers and Chesapeake Bay. Generally, these waterbodies can be categorized into three basic types of shallow draft channels: federally-authorized to include aids to navigation (ATONS), non-federal with ATONS, and non-federal without ATONs. Along the Northern Neck, presently identified, are 13 federal channels, 37 non-federal channels in creeks with ATONs, and 92 in creeks without defined channels or ATONs, for a total of 142 waterbodies. Additional non-federal creeks, coves, branches, and ponds (all are interchangeably identified as waterbodies in this report) occur in these localities, but the analysis was limited to waterbodies that had some residential or economic usage. These waterbodies occur in Lancaster (35 waterbodies), Northumberland (67 waterbodies), Richmond (4 waterbodies), and Westmoreland (31 waterbodies) counties. To avoid double counting of waterbodies, 5 additional waterbodies that are located on the boundaries of these counties were attributed to just one county for this report. These waterbodies have been grouped within one of their boundary counties bringing the number of waterbodies in Lancaster to 38 and Westmoreland to 33. Physical parameter data was collected or created for each of these waterbodies. These data included creek mouth morphology, amount of shoaling in the waterbody mouth, waterbody type (primary, secondary, etc.), water surface area, combined shoreline length, historical (1971- 2020) and current (2016-2020) SAV presence, private and public oyster lease presence and the amount of area they cover, number of remotely-sensed coastal structures such as piers, marinas, boat ramps, and verified economic facilities such as marinas and other mooring places, resource, seafood related, and transportation facilities that impact the locality’s economics. Utilizing the collected data, the steps that localities need to take for additional data collection to develop a dredging project were outlined, and recommendations were made for additional regional management considerations for use in Phases 2 and 3. Finally, next steps were suggested. By creating a regional program for dredging of shallow water, localities can save time, effort, and money. Such a program also provides ways for localities to plan for the utilization of dredge material to combat repetitive flooding and improve coastal resiliency

Shoreline evolution, City of Hampton, Virginia, Hampton Roads, Chesapeake Bay, and Back River Shorelines

Shoreline evolution is the change in shore position through time. In fact, it is the material resistance of the coastal geologic underpinnings against the impinging hydrodynamic (and aerodynamic) forces. Along the shores of Chesapeake Bay, it is a process-response system. The processes at work include winds, waves, tides and currents, which shape and modify coastlines by eroding, transporting and depositing sediments. The shore line is commonly plotted and measured to provide a rate of change but it is as important to understand the geomorphic patterns of change. Shore analysis provides the basis to know how a particular coast has changed through time and how it might proceed in the future. The purpose of this report is to document how the Hampton Roads, Chesapeake Bay, and Back River shores of Hampton (Figure 1) has evolved since 1937. Aerial imagery was taken for most of the Bay region beginning that year, and it is this imagery that allows one to assess the geomorphic nature of shore change. Aerial imagery shows how the coast has changed, how beaches, dunes, bars, and spits have grown or decayed, how barriers have breached, how inlets have changed course, and how one shore type has displaced another or has not changed at all. Shore change is a natural process but, quite often, the impacts of man through shore hardening or inlet stabilization come to dominate a given shore reach. Most of the change in shore positions will be quantified in this report. Others, particularly very irregular coasts, around inlets, and other complicated areas will be subject to interpretation

Shoreline Evolution Chesapeake Bay Shoreline Northampton County, VA

Shoreline evolution is the change in shore position through time. In fact, it is the material resistance of the coastal geologic underpinnings against the impinging hydrodynamic (and aerodynamic) forces. Along the shores of the Chesapeake Bay, it is a process-based response system. The processes at work include winds, waves, tides, and currents, which together provide the energy which shapes and modifies coastlines by eroding, transporting, and depositing sediments. The shore line is commonly plotted and measured to provide a rate of change, but it is as important to understand the geomorphic patterns of change. Shore analysis provides the basis to know how a particular coast has changed through time and how it may proceed in the future. The purpose of this report is to document how the Bay shore of Northampton County, Virginia (Figure 1) has evolved since 1938. Aerial imagery was taken for most of the Bay region beginning that year, and it is this imagery that allows one to assess the geomorphic nature of shore change. Aerial imagery shows how the nature of the coast has changed, how beaches, dunes, bars, and spits have grown or decayed, how barriers have breached, how inlets have changed course, and how one shore type has displaced another or has not changed at all. Shore change is a natural process but, quite often, the impacts of man through shore hardening or inlet stabilization come to dominate a given shore reach. Most of the shore positions will be quantified in this report. Others, particularly very irregular coasts, around inlets, and other areas will be subject to interpretation

Dune Evolution Westmoreland County, Virginia Potomac River Shoreline

Shoreline evolution is the change in shore position through time. In fact, it is the material resistance of the coastal geologic underpinnings against the impinging hydrodynamic (and aerodynamic) forces. Along the shores of Chesapeake Bay, it is a process-response system. The processes at work include winds, waves, tides and currents, which shape and modify coastlines by eroding, transporting and depositing sediments. The shore line is commonly plotted and measured to provide a rate of change but it is as important to understand the geomorphic patterns of change. Shore analysis provides the basis to know how a particular coast has changed through time and how it might proceed in the future. The purpose of this report is to document how the dunes on Potomac River shores of Westmoreland (Figure 1) have evolved since 1937. Aerial imagery was taken for most of the Bay region beginning that year, and it is this imagery that allows one to assess the geomorphic nature of shore change. Aerial imagery shows how the coast has changed, how beaches, dunes, bars, and spits have grown or decayed, how barriers have breached, how inlets have changed course, and how one shore type has displaced another or has not changed at all. Shore change is a natural process but, quite often, the impacts of man through shore hardening or inlet stabilization come to dominate a given shore reach. Most of the change in shore positions where dunes occur will be quantified in this report. Others, particularly very irregular coasts, around inlets, and other complicated areas will be subject to interpretation