https://erdc-library.erdc.dren.mil:443/xmlui The Knowledge Core, a service of the U.S. Army Engineer Research and Development Center (ERDC) Information Science and Knowledge Management (LSKM) Branch, collects, preserves and distributes ERDC's research publications and historical knowledge. The growing collection includes articles, technical reports, working papers, photographs, videos and more. Wed, 12 Jul 2017 06:06:01 GMT 2017-07-12T06:06:01Z http://hdl.handle.net/11681/22724 Design of deflectors for Little Goose Spillway, Snake River, Oregon : a physical model study Wilhelms, Steven C.; Yates, Laurin I. Abstract: Based on the results of the Dissolved Gas Abatement Studies, spillway deflectors were recommended for the exterior bays of the Little Goose Spillway to reduce total dissolved gas production during spill operations. The design of the deflectors was developed by examining their hydraulic performance in a 1:40-scale section model of the spillway. Four different deflector designs were compared relative to flow conditions in the stilling basin and tailrace area of the section model. The authors recommend the design of the existing deflector, designated Type I, which is 8 feet (ft) long at elevation 532.0 (National Geodetic Vertical Datum) with no transition radius for the exterior bays at Little Goose Spillway. There was essentially no difference in the performance character of the Type I deflector and the Type II deflector (12 ft long without transition radius) over the design discharge range of 7,000–10,000 cubic feet per second per spill bay. Velocities, as high as 17 ft/second, were measured along the tailrace channel bottom. Detailed hydrographic survey data should be taken in the stilling basin and tailrace to assess changes in bathymetry caused by potential scour or ball-mill grinding. Thu, 01 Jun 2017 00:00:00 GMT http://hdl.handle.net/11681/22724 2017-06-01T00:00:00Z http://hdl.handle.net/11681/22722 Geologic controls of sand boil formation at Buck Chute, Mississippi Martin, Seth M.; Dunbar, Joseph B.; Corcoran, Maureen K.; Schmitz, Darrel Wayne. Abstract: Sand boil formation due to underseepage is a potential failure mechanism for levees in the Lower Mississippi River Valley. Sand boils were identified in the Buck Chute study area in the 1990s during high-water events and during the 2009 Flood. The site is unique due to the presence of point bar and abandoned channel deposits. To understand the role of these alluvial deposits on sand boil formation at the site, a geologic investigation of the subsurface was conducted. Using shallow geophysics, cone penetrometer tests (CPT), borings, and a geographic information system (GIS), researchers concluded that the thin blanket associated with point bar deposits, abandoned channel deposits causing a blocked seepage path, and head differential changes caused by the Muddy Bayou Control Structure were the controls of sand boil formation at Buck Chute. Thu, 01 Jun 2017 00:00:00 GMT http://hdl.handle.net/11681/22722 2017-06-01T00:00:00Z http://hdl.handle.net/11681/22721 Invasive species management on military lands : clustered regularly interspaced short palindromic repeat/CRISPR-associated protein 9 (CRISPR/Cas9)-based gene drives Gong, Ping. Abstract: Applications of genetic engineering-based technologies to the control of invasive species are emerging as an important area of innovation. As a mechanism to spread the desired genes and associated traits into the target population, gene drive is recognized as a promising genetic biocontrol strategy to combat invasive species. Unlike existing technologies that depend on the cumbersome custom-making of new proteins for each DNA target, the CRISPR system uses RNA as its DNA-homing mechanism, which makes it low cost, high efficiency, easy to implement, and it dramatically shortens the design-build-test cycle for gene drive development. The CRISPR/Cas9 technology can alter multiple loci at the target gene that prevent mutations from blocking the spread of the drive. It can also be used to develop multiple types of gene drives such as precision, immunization and reversal drives to precisely target a specific subpopulation, protect a population from any future gene drive “invasions,” and overwrite previously released drives in case of unanticipated effects, respectively. Poised to become a self-sustaining, highly efficient, environmentally benign, and cost-effective alternative for invasive species control, CRISPR/Cas9-mediated gene drives can sweep a “deleterious” gene through a population exponentially faster than the normal Mendelian inheritance, and thus suppress or eradicate the target invasive species. Thu, 01 Jun 2017 00:00:00 GMT http://hdl.handle.net/11681/22721 2017-06-01T00:00:00Z http://hdl.handle.net/11681/22701 Report on Hurricane "Beulah", 8-21 September 1967 United States. Army. Corps of Engineers. Galveston District. Foreword: Hurricane "Beulah" was first reported by the Weather Bureau as a tropical depression on 7 September 1967. It then began its long westerly course towards the southern Texas area. At about 6:00 a.m. CST on 20 September, thirteen days after the first advisory was issued, Hurricane "Beulah" crossed the most southern tip of Texas. In its devastating wake, "Beulah" left a reported 44 persons dead and thousands homeless. A total of 115 tornadoes spawned by Hurricane "Beulah" was reported by the Weather Bureau. The previous record was 26 tornadoes spawned by Hurricane "Carla" in 1961. Not all damages can be attributed to tornadoes and to the storm surge which inundated approximately 630,000 acres of coastal lowlands. Approximately 1.4 million acres of land were inundated from stream flooding and ponded water due to the torrential rains that accompanied the storm. "Beulah" disrupted transportation, communication, and utility service· throughout the southern area of Texas for weeks. Twenty-nine counties in south Texas were declared a major disaster area by the President. The purpose of this report is to record the pertinent meteorologic and hydrologic phenomena of the storm and to present an evaluation of the damages to physical property that resulted from this hurricane. The data presented and the conclusions drawn from these results are as accurate as possible with the time, manpower, and funds available to collect the field data. Report Sun, 01 Sep 1968 00:00:00 GMT http://hdl.handle.net/11681/22701 1968-09-01T00:00:00Z