Temporal And Spatial Variations Of The Chesapeake Bay Plume

Historical records and data obtained during the Superflux experiments are used to describe the temporal and spatial variations of the effluent waters of Chesapeake Bay. The alongshore extent of the plume resulting from variations of fresh water discharge into the Bay and the effects of wind are illustrated. Variations of the cross-sectional configuration of the plume over portions of a tidal cycle and results of a rapid-underway water sampling system are discussed.https://scholarworks.wm.edu/vimsbooks/1131/thumbnail.jp

Suspended Sediments near Pier 12 Norfolk Navy Base on 26 June and 15 September, 1973

Results of two suspended sediment studies near Norfolk Navy Base Pier 12 are given. The studies were conducted during one tidal cycle on both 26 June and 15 September 1973. The following parameters were measured at five stations in the vicinity of the pier: suspended sediment water temperature, salinity and density current speed and direction i

Changes in salinity structure of the James, York and Rappahannock estuaries resulting from the effects of Tropical Storm Agnes

The peak effect of the flood waters produced by Tropical Storm Agnes was seen on June 25 in the James, June 26 in the Rappahannock, and June 30 in the York. Recovery toward normal salinity conditions after the high runoffs proceeded discontinuously, with alternating periods of vertical stratification and destratification. During strongly stratified stages, saline water advanced upstream along the bottom. In the York and James Rivers, the most dramatic stratification occurred about July 20- 25. This event resulted in bottom salinity values exceeding normal ambient values and, at the river mouths, reaching values hitherto unobserved. This event was apparently controlled by the salinity distribution in the Bay. ~ess pronounced stratification maxima occurred in the James about July 6 and August 18 and in the York during August. These events do not appear to be correlated with stream gauge flow records or local precipitation. These events are possible instances of overshooting of equilibrium by the intruding salt water near the bottom.https://scholarworks.wm.edu/vimsbooks/1042/thumbnail.jp

Study to Investigate Source and Transport Route of Marine Organisms (Hydroids and Bryozoans) in Hampton Roads and Current Velocity Profiles of the Pier 12 Area, Naval Station, Norfolk, Virginia

Entrainment of the hydroid (Sertularia argentea) and the fleshly bryozoan (Alcyonidium verrilli) in the sea suction of deep draft naval vessels (carriers) in the area of the Norfolk Naval station has been a recurring problem since the early 60\u27s. These fouling organisms (the term fouling is used in this report to indicate clogging of hull bottom intake grates and cooling system condenser tube sheets and not the growth of organisms on any part of the vessel) are winter species, growing only in the fall and winter and not the summer. Unfortunately they are also the most abundant and widely distributed species of hydroid and bryozoan in the entire Chesapeake Bay. The problems caused by the fouling organisms in the Pier 12 area are not a result of organisms that have grown up within Pier 12, but result from adult organisms that have been transported to the pier area by water currents. The transport of organisms into Pier 12, which acts as a settling basin, combined with deep vessel draft and vessel pre-departure procedures are the three main elements that form the fouling problem. more ...

Interaction Between Circulation of the Estuary of the James River and Transport of Oyster Larvae

Hydraulic model dye test results are examined to provide estimates of nontidal horizontal circulation and movement/retention of oyster larvae in the James River Estuary. Test conditions maintained a constant mean tide and average summer low freshwater discharge. It was assumed that movement of dye in the model would approximate movement of the planktonic (larval) stages of oysters (Crassostroa virginica) in the prototype. Test results were used to rank six dye release points (candidate brood stock locations) with respect to relative quantities of dye retained in areas of the model representing commercially important seed oyster beds during the period 20-40 tidal cycles after release (the time, after spawning, when oyster larvae will permanently attach to a suitable substrate). Under the test conditions, nontidal circulation in the model was similar to that found in a weak partially mixed estuary: upstream motion along the bottom and over the right hand shoals (looking upstream) and downstream motion elsewhere. The pattern was modified by cyclonic motion of surface waters in the upstream and downstream reaches which increased residence time of material in the seed oyster bed region. Greatest retention during the 20-40 tidal cycle period was from releases over upstream and right hand side shoals and is reflected in release point ranking.https://scholarworks.wm.edu/vimsbooks/1031/thumbnail.jp

Overcoming the level bubble : terrestrial laser scanning reference frame transformations

Terrestrial Laser Scanning (TLS) is an efficient, effective, and precise measurement tool rapidly growing in popularity in a wide variety of fields. Use of TLS data often requires aligning multiple scans for a more complete model of a scene or object, a procedure known as scan registration. Each scan setup must be transformed (i.e., rotated, scaled, and translated) and adjusted to match the other setups as closely as possible. This research investigates and compares the traditional least squares method against a rapid, noniterative technique recently proposed and develops possible solutions to achieve the strengths of both methods. Additionally, modern TLS instruments are commonly equipped with an inclination sensor to measure deviations from a level setup in order to simplify the registration process. This thesis investigates the reliability, usefulness, and limitations of these sensors. In particular, the concept of a "stability threshold" that ensures reliable inclination measurements in modern, rapid scanners is introduced and sources of inclination sensor error, and procedures to minimize that error, are investigated. While level and unlevel setups appear to produce consistent results, full 360° scan windows measured in both the clockwise and counter-clockwise direction are recommended. Finally, some field applications of TLS reference frame transformations are presented and discussed, including the development of a coordinate system in a large-scale research laboratory and steps toward the development of real-time change detection

New Renewable and Biodegradable Particleboards from Jatropha Press Cakes

The influence of thermo-pressing conditions on the mechanical properties of particleboards obtained from Jatropha press cakes was evaluated in this study. Conditions such as molding temperature and press cake oil content were included. All particleboards were cohesive, with proteins and fibers acting respectively as binder and reinforcing fillers. Generally, it was the molding temperature that most affected particleboard mechanical properties. The most resistant boards were obtained using 200°C molding temperature. Glass transition of proteins then occurred during molding, resulting in effective wetting of the fibers. At this optimal molding temperature, the best compromise between flexural properties (7.2 MPa flexural strength at break and 2153 MPa elastic modulus), Charpy impact strength (0.85 kJ/m²) and Shore D surface hardness (71.6°), was a board obtained from press cake with low oil content (7.7%). Such a particleboard would be usable as interlayer sheets for pallets, for the manufacture of containers or furniture, or in the building trade

Recovery self-efficacy and intention as predictors of running or jogging behavior: a cross-lagged panel analysis over a two-year period

Objectives: The study investigates whether two kinds of self-efficacy and intention predict regular running or jogging behavior over 2 yr. Maintenance self-efficacy refers to beliefs about one's ability to maintain a behavior, whereas recovery self-efficacy pertains to beliefs about one's ability to resume a behavior after a setback. Design and methods: Longitudinal data from runners (N=139, 80% men) were collected twice with a time gap of 2 yr. Results: Cross-lagged panel analysis revealed that recovery self-efficacy and intention jointly predicted running/jogging behavior 2 yr later, whereas running/jogging behavior did not predict recovery self-efficacy and intention. No effects of maintenance self-efficacy were found. The majority of participants (n=120) experienced at least one 2-week period of decline in running or jogging behavior. Among those who experienced lapses, recovery self-efficacy remained the only significant social-cognitive predictor of behavior. Conclusions: Recovery self-efficacy is a crucial predictor of regular running or jogging behavior over 2 yr