Interpretative Analysis of Surfical Sediments as an Aid in Transport Studies of Dredged Materials, Cape Canaveral, Florida

Source: https://erdc-library.erdc.dren.mil/jspui/Analyses of surface and core sediment samples; dredging records; bathymetric surveys; wind, wave, and current data; and pertinent literature were undertaken to determine the amount and direction of sediment transport from a dredge disposal site. The site is located 4.5 miles east of Cocoa Beach, Florida, in 40-55 ft of water, on the inner continental shelf. Dredge disposal material is composed of clay, silt, and fine sand removed from the entrance channel t o Port Canaveral Harbor located approximately 7 miles to the north. Volumetric calculations were made using 1983 bathymetric data. Comparison between the bathymetric data and the known amount of sediment placed on the site during disposal operations (1974-1983) indicates a loss of material from the site. However, consolidation of disposal material, unknown predisposal bathymetry, and "short-dumping" could account for much of the loss. Sediment analysis and subsequent plotting of sedimentologic parameters (mean grain size, standard deviation, and skewness) revealed no trends in sediment distribution at the disposal site. Insufficient sample intensity and the general similarity in the size and composition of the dredge disposal material and the indigenous shelf sediments may explain the lack of identifiable trends in sediment distribution. Sediment transport studies conducted in the Cape Canaveral region by previous investigators indicate that net movement is alongshore, or approximately north- south. The variability of local winds and currents in the vicinity of Cape Canaveral makes such generalizations only moderately reliable relative to this specific disposal site. Sand waves on the shelf surface, detected on side- scan sonar profiles, indicate recent current activity at the disposal site capable of transporting sediment. Results of this study suggest that detailed site-specific data are necessary in order to make conclusive statements about sediment transport off the disposal site

Inlet Processes at Eel Pond, Falmouth, Massachusetts

Source: https://erdc-library.erdc.dren.mil/jspui/This report describes a combined office and field study designed to define the causes of a shoaling problem at the entrance to a small craft harbor. The office study consisted of an evaluation of the history of inlet development and an analysis of available wind, current, and wave data. In addition, a one dimensional numerical model was used to predict stability with varying inlet geometry and the addition of stabilizing structures. Field measurements used in model calibration included water level, current velocity, beach and nearshore sediment samples, bathymetric surveys, and bedform measurements. Inlet hydraulics were found to be dominated by flood tidal flow through Eel Pond into the adjoining Waquoit Bay, causing the pond to act as a sediment sink. Several modifications to the inlet geometry are proposed for reducing inlet shoaling rates

PREDICTING THE ENERGY COST OF STEEP UPHILL TREADMILL WALKING: A CROSS-VALIDATION

PREDICTING THE ENERGY COST OF STEEP UPHILL TREADMILL WALKING: A CROSS-VALIDATION E.Davila1, E.C. Ranta1, L.M. Whalen1, D. Weishar2, A. Blake2, D.E. Lankford2, & D.P. Heil, FACSM1. 1Montana State University, Bozeman, MT; 2Brigham Young University, Rexburg, ID INTRODUCTION: There are a growing number of commercially-available electronic monitoring devices that claim to predict the energy cost of exercising as a function of one or more predictive metrics. Devices relying upon global positioning satellite (GPS) data, for example, can predict the energy cost of walking and running outdoors by determining real-time changes in travel speed and surface incline. These data can then be combined with a laboratory-derived prediction algorithm, but the algorithm must include both steep uphill and downhill inclines to remain ecologically valid. A well-known formula by Minetti et al. (JAP 2002), considered valid for inclines between -45% and +45%, would seem well suited but does not appear to have been cross-validated in the literature. The purpose of this study was to cross-validate the original Minetti formula for predicting relative energy cost (CW, J/kg/m) between -5% and +30% for treadmill walking using a broad range of healthy adults. METHODS: 31 recreationally-active adults (18 men: (Mean±SD) 28 ± 8 yrs, 20-45 yrs, and 23.0±3.3, 21.0-34.4 kg/m2; 13 women: 29 ± 3 yrs, 25-35 yrs, and 23.1±2.8, 19.1-29.8 kg/m2) were recruited to walk on a treadmill at 53.6 m/min (2.0 MPH) at one of four lower inclines (-5%, -2.5%, 0%, +8%) and one of four steeper inclines (+15%, +19%, +22.5%, +30%) across four separate lab visits for 20 mins at each incline. Steady-state oxygen consumption (VO2), recorded via standard indirect calorimetry procedures, were averaged from the end of each 20-min test. Net VO2 (exercise VO2 – resting VO2) was then converted to CW using the measured non-protein RER, body mass, and treadmill speed. Predicted CW, as determined from the original Minetti formula, was compared to measured CW using a two-factor repeated measures ANOVA, including a comparison by gender, at each incline (0.05 alpha). RESULTS: Mean predicted CW was statistically similar between genders for both measured and predicted CW. In contrast, measured CW was significantly lower (P\u3c0.001) than predicted CW at the lower inclines (≤ +15%), statistically similar at the +19% incline, and significantly higher at the steepest inclines (+22.5% and +30%; P\u3c0.001). CONCLUSIONS: The Minetti formula for predicting CW for steep downhill and uphill walking was derived using well-trained men accustomed to mountain running. The present study, in contrast, used a more diverse adult population (i.e., recreationally active, men and women, wide range of BMI) which suggests that the Minetti formula may lack a broad generalizability for the range of inclines tested (-5% to +30%) for populations dissimilar to the original validation sample