Abstract: A optical scour sensor monitors scour, including deposition and ablation, in bodies of water that may be too lossy to enable use of electrical signals. A specially configured optical fiber is inserted into the sediment and the interface between the sediment and water thereby monitored using a top-mounted control box to pulse light down the cable and capture reflected signals. The optical fiber may be armored by a soft plastic concentric shield and incorporate a micro-bend inducer for detecting minute indentations in the fiber. The presence of a non-liquid, e.g., sediment, against the cable is detected because the sediment impinges on the fiber causing an indentation therein. At each indentation a reflection is sent back to the source. Using principles of optical time domain reflectometry (OTDR), the location of the indentiation is determined. The data are fed to a remote system for processing, analysis and display.
Type:
Grant
Filed:
June 13, 2001
Date of Patent:
February 25, 2003
Assignee:
The United States of America as represented by the Secretary
of the Army
Abstract: A device for securing a knot in a tight condition in a cord includes a generally tubular member defining a longitudinal hole therethrough. The tubular member includes a score line for dividing it into two sections by applying a bending or torsional force on the ends thereof. The tubular member further includes a longitudinal slit extending substantially through the thickness thereof. A pre-stretched elastomeric band is disposed around the tubular member.
Type:
Grant
Filed:
August 25, 2000
Date of Patent:
October 8, 2002
Assignee:
The United States of America Corps of Engineers as
respresented by the Secretary of the Army
Abstract: A geotechnical structure that includes a first body of soil having a first unsaturated concentration of moisture. There is also a second body of soil, which includes a second unsaturated concentration of moisture that is different from the first concentration. A moisture barrier is interposed between the first body of soil and the second body of soil. The moisture barrier includes an upper and lower layer that draw water laterally. A medial capillary barrier layer prevents traverse moisture migration between the first and second bodies of soil. Moisture migration both upwardly and downwardly is thus prevented, and water in the first and second bodies of unsaturated soil is drained laterally to reduce pore water pressures in the first and second bodies of soil.