Science.gov

Sample records for erosion control project

  1. Demonstration Erosion Control Project Monitoring Program. Fiscal Year 1994 Report.

    DTIC Science & Technology

    1996-12-01

    Technical Report HL-96-22 December 1996 US Army Corps of Engineers Waterways Experiment Station Demonstration Erosion Control Project...C. Watson, Colorado State University Approved For Public Release; Distribution Is Unlimited 19970520 143 Prepared for U.S. Army Engineer District...Derrick, Billy E. Johnson, Michael J. Trawle U.S. Army Corps of Engineers Waterways Experiment Station 3909 Halls Ferry Road Vicksburg, MS 39180

  2. Targeting Erosion Control: Adoption of Erosion Control Practices. A Report from a National Research Project.

    ERIC Educational Resources Information Center

    West, Peter; And Others

    Research analyzed adoption of erosion control practices by farm operators in two counties in each of four states: Alabama, Missouri, Tennessee, and Washington. Analysis was based on farm survey data and technical and financial assistance information from county Soil Conservation Service (SCS) and Agricultural Stabilization and Conservation Service…

  3. 33 CFR 263.26 - Small beach erosion control project authority (Section 103).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Small beach erosion control project authority (Section 103). 263.26 Section 263.26 Navigation and Navigable Waters CORPS OF ENGINEERS....26 Small beach erosion control project authority (Section 103). (a) Legislative authority....

  4. 33 CFR 263.26 - Small beach erosion control project authority (Section 103).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Small beach erosion control project authority (Section 103). 263.26 Section 263.26 Navigation and Navigable Waters CORPS OF ENGINEERS....26 Small beach erosion control project authority (Section 103). (a) Legislative authority....

  5. 33 CFR 263.26 - Small beach erosion control project authority (Section 103).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Small beach erosion control project authority (Section 103). 263.26 Section 263.26 Navigation and Navigable Waters CORPS OF ENGINEERS....26 Small beach erosion control project authority (Section 103). (a) Legislative authority....

  6. 33 CFR 263.26 - Small beach erosion control project authority (Section 103).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Small beach erosion control project authority (Section 103). 263.26 Section 263.26 Navigation and Navigable Waters CORPS OF ENGINEERS....26 Small beach erosion control project authority (Section 103). (a) Legislative authority....

  7. 33 CFR 263.26 - Small beach erosion control project authority (Section 103).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Small beach erosion control project authority (Section 103). 263.26 Section 263.26 Navigation and Navigable Waters CORPS OF ENGINEERS....26 Small beach erosion control project authority (Section 103). (a) Legislative authority....

  8. Demonstration and Erosion Control Project Monitoring Program, Fiscal Year 1992 Report. Volume 5, Appendix D. Stream Gauging Data Report

    DTIC Science & Technology

    1993-11-01

    Monitoring Program Fiscal Year 1992 Report Volume V: Appendix D Stream Gauging Data Report DTICS ELECTEmmm by David D. Abraham, Steve Sutton EJAN04...November 1993 Demonstration Erosion Control Project Monitoring Program Fiscal Year 1992 Report Volume V: Appendix D Stream Gauging Data Report by David D...39180-5191 us Ai Co"p of engine.. Walsuways Experimen Sim~on Calmiogingn-Pufcatn Date Abraham, David D. DemostraionErosion Control Project Monitoring

  9. Emergency wind erosion control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    February through May is the critical time for wind erosion in Kansas, but wind erosion can happen any time when high winds occur on smooth, wide fields with low vegetation and poor soil structure. The most effective wind erosion control is to ensure a protective cover of residue or growing crop thro...

  10. Projected changes in US erosivity

    NASA Astrophysics Data System (ADS)

    Biasutti, M.; Seager, R.

    2015-02-01

    Downscaled rainfall projections from 21 climate models from the CMIP5 archive are used to estimate future changes in rainfall erosivity in the continental Unites States. To estimate erosivity from rainfall in the absence of sub-hourly data, we have used both daily rainfall values and the modified Fournier Index - which is based on monthly rainfall accumulation - and derived the scaling relationship between rainfall and erosivity from observational estimates of both. The expectation of overall increase in erosivity is confirmed by these calculations, but a quantitative assessment is marred by large uncertainties. Specifically, the uncertainty in the method of estimation of erosivity is more consequential than that deriving from the spread in climate simulations, and leads to changes of uncertain sign in parts of the Southwest and Texas. We suggest that progress can be made by establishing a more reliable functional relationship between daily rainfall and erosivity.

  11. Lincoln Park shoreline erosion control project: Monitoring for surface substrate, infaunal bivalves and eelgrass, 1993

    SciTech Connect

    Antrim, L.D.; Thom, R.M.; Gardiner, W.W.

    1993-09-01

    In 1988, the US Army Corps of Engineers and the City of Seattle placed material on the upper beach at Lincoln Park, in West Seattle, Washington. The fill served to mitigate shoreline erosion that had caused undercutting and collapse of the seawall in several places. A series of pre- and post-construction studies have been conducted to assess the impacts to marine biota of fill placement and movement of surface substrate. This study was designed to monitor infaunal bivalves and eelgrass from intertidal areas in and adjacent to the area of original fill placement. Findings from this survey were compared to previous survey results to determine (1) if recruitment of infaunal bivalves to the fill area has occurred, (2) if infaunal bivalve densities outside the fill area are stable, and (3) if eelgrass distribution and abundance have remained stable along the adjacent shoreline. To maximize comparability of findings from this survey with previous studies, sampling techniques, transects, and tidal elevations were consistent with previous studies at this site.

  12. Projected changes in US rainfall erosivity

    NASA Astrophysics Data System (ADS)

    Biasutti, M.; Seager, R.

    2015-06-01

    Downscaled rainfall projections from 21 climate models from the CMIP5 (Coupled Model Intercomparison Project Phase 5) archive are used to estimate future changes in rainfall erosivity in the continental Unites States. To estimate erosivity from rainfall in the absence of sub-hourly data, we have used both daily rainfall values and the modified Fournier index - which is based on monthly rainfall accumulation - and derived the scaling relationship between rainfall and erosivity from observational estimates of both. The expectation of overall increase in erosivity is confirmed by these calculations, but a quantitative assessment is marred by large uncertainties. Specifically, the uncertainty in the method of estimation of erosivity is more consequential than that deriving from the spread in climate simulations and leads to changes of uncertain sign in parts of the southwest and Texas. We suggest that progress can be made by establishing a more reliable functional relationship between daily rainfall and erosivity.

  13. Erosion Control Management Plan for Army Training Lands

    DTIC Science & Technology

    1990-07-01

    ECMP), which will provide guidance for reducing soil erosion, resource loss , stream pollution, and offsite sedimen- tation. This report describes ECMP...erosion, resource loss , stream pollution, and offsite sedimenta:ion. This report describes ECMP, which offers procedures to accurately identify erosion...Center (USAEHSC) under Project 4A162720A896, " Base Facility Environmental Quality" Work Unit AO;047, "Physi- cal/Structural Erosion Control for

  14. Robotic weld overlay coatings for erosion control

    SciTech Connect

    Not Available

    1994-11-01

    The erosion of materials by the impact of solid particles has received increasing attention during the past twenty years. Recently, research has been initiated with the event of advanced coal conversion processes in which erosion plays an important role. The resulting damage, termed Solid Particle Erosion (SPE), is of concern primarily because of the significantly increased operating costs which result in material failures. Reduced power plant efficiency due to solid particle erosion of boiler tubes and waterfalls has led to various methods to combat SPE. One method is to apply coatings to the components subjected to erosive environments. Protective weld overlay coatings are particularly advantageous in terms of coating quality. The weld overlay coatings are essentially immune to spallation due to a strong metallurgical bond with the substrate material. By using powder mixtures, multiple alloys can be mixed in order to achieve the best performance in an erosive environment. However, a review of the literature revealed a lack of information on weld overlay coating performance in erosive environments which makes the selection of weld overlay alloys a difficult task. The objective of this project is to determine the effects of weld overlay coating composition and microstructure on erosion resistance. These results will lead to a better understanding of erosion mitigation in CFB`s.

  15. Robotic weld overlay coatings for erosion control

    NASA Astrophysics Data System (ADS)

    The erosion of materials by the impact of solid particles has received increasing attention during the past twenty years. Recently, research has been initiated with the event of advanced coal conversion processes in which erosion plays an important role. The resulting damage, termed Solid Particle Erosion (SPE), is of concern primarily because of the significantly increased operating costs which result in material failures. Reduced power plant efficiency due to solid particle erosion of boiler tubes and waterfalls has led to various methods to combat SPE. One method is to apply coatings to the components subjected to erosive environments. Protective weld overlay coatings are particularly advantageous in terms of coating quality. The weld overlay coatings are essentially immune to spallation due to a strong metallurgical bond with the substrate material. By using powder mixtures, multiple alloys can be mixed in order to achieve the best performance in an erosive environment. However, a review of the literature revealed a lack of information on weld overlay coating performance in erosive environments which makes the selection of weld overlay alloys a difficult task. The objective of this project is to determine the effects of weld overlay coating composition and microstructure on erosion resistance. These results will lead to a better understanding of erosion mitigation in CFB's.

  16. Robotic weld overlay coatings for erosion control

    SciTech Connect

    Levin, B.F.; Dupont, J.N.; Marder, A.R.

    1993-04-18

    Twelve weld overlay hardfacing alloys have been selected for preliminary erosion testing based on a literature review These alloys have been separated into three major groups: (1) Cobalt containing alloys, (2) Nickel-base alloys, (3) Iron base alloys. These alloys are being applied to carbon steel substrates and will undergo preliminary erosion testing to identify candidates weld overlay alloys for erosion control in CFB boilers. The candidate alloys selected from the preliminary erosion tests will then undergo more detailed evaluations in future research.

  17. 78 FR 34374 - Notice of Availability of Final Revisions to the Upland Erosion Control, Revegetation, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-07

    ... Energy Regulatory Commission Notice of Availability of Final Revisions to the Upland Erosion Control... of the Office of Energy Projects has revised its Upland Erosion Control, Revegetation, and... minimizing erosion, enhancing revegetation, and minimizing the extent and duration of disturbance on...

  18. Controlling erosion in the Missouri River Basin

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-09-01

    The most pervasive conservation concern in the vast 510,000 square mile Missouri River basin in the western United States is excessive rates of wind erosion during dry periods, though conservation efforts can help control erosion, according to a 30 August report by the U.S. Department of Agriculture's (USDA) Conservation Effects Assessment Project. During some dry years, rates of wind erosion—which include nitrogen and phosphorus losses—can be higher than 4 tons per acre on 12% and higher than 2 tons per acre on 20% of the approximately 148,000 square miles of cultivated cropland, notes the report Assessment of the Effects of Conservation Practices on Cultivated Cropland in the Missouri River Basin. Between 2003 and 2006, conservation practices, including reducing tillage and building terraces, yielded about a 75% reduction in sediment runoff and phosphorus loss and a 68% reduction in nitrogen loss, according to the report. About 15 million acres in the region—18% of cultivated cropland—are considered to have either a high or moderate level of need for conservation treatment, and efforts in those areas in particular could result in additional reductions in sediment, phosphorus, and nitrogen loss, the report states.

  19. Airphoto analysis of erosion control practices

    NASA Technical Reports Server (NTRS)

    Morgan, K. M.; Morris-Jones, D. R.; Lee, G. B.; Kiefer, R. W.

    1980-01-01

    The Universal Soil Loss Equation (USLE) is a widely accepted tool for erosion prediction and conservation planning. In this study, airphoto analysis of color and color infrared 70 mm photography at a scale of 1:60,000 was used to determine the erosion control practice factor in the USLE. Information about contour tillage, contour strip cropping, and grass waterways was obtained from aerial photography for Pheasant Branch Creek watershed in Dane County, Wisconsin.

  20. Geospatial application of the Water Erosion Prediction Project (WEPP) model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Water Erosion Prediction Project (WEPP) model is a process-based technology for prediction of soil erosion by water at hillslope profile, field, and small watershed scales. In particular, WEPP utilizes observed or generated daily climate inputs to drive the surface hydrology processes (infiltrat...

  1. Engineering geomorphology at the cutting edge of land disturbance: erosion and sediment control on construction sites

    NASA Astrophysics Data System (ADS)

    Harbor, Jon

    1999-12-01

    Construction site management, traditionally dominated by professional engineers, provides an important opportunity for engineers and geomorphologists to work together in minimizing the environmental impacts of land disturbance. Areas disturbed for construction activity have soil erosion rates from 2 to 40,000 times greater than pre-construction conditions, and are important components of nonpoint source (NPS) pollution that degrades surface water quality. Despite significant local-to-watershed-scale environmental and economic impacts, the lack of an individual economic incentive for land developers to control erosion has limited voluntary adoption of erosion and sediment control measures. However, increased regulatory requirements, combined with efforts to identify and publicize the benefits of erosion control, are increasing the number of construction sites on which erosion control efforts are being implemented. Geomorphologists have the opportunity to play an active role in erosion and sediment control by implementing knowledge of erosion and sedimentation processes and of the variables that effect these processes. Pre-project geomorphological site assessments allow project designers to work around areas with high erosion potential, and to stage and schedule land disturbing activities to minimize erosion potential. Combined engineering and geomorphological analyses can increase the likelihood that streams and drainage channels are stable under altered hydrologic conditions, both during and after land use change, and can be used to design a drainage plan that minimizes surface water flow through disturbed areas. A variety of temporary measures to reduce erosion and to trap sediment on site can be designed and implemented, such as temporary surface covers, silt fence, and sedimentation basins. However, design and implementation of these measures require an understanding of erosion and sedimentation processes, and in many cases incorrect installation and maintenance

  2. Principles of Wind Erosion and its Control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nearly sixty years after the Dust Bowl ended, wind erosion continues to threaten the sustainability of our nations' natural resources. This publication presents a review of the current state of wind erosion science by describing the problem of wind erosion, the physical basis of wind erosion proces...

  3. 7 CFR 3201.68 - Erosion control materials.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Erosion control materials. 3201.68 Section 3201.68... Designated Items § 3201.68 Erosion control materials. (a) Definition. Woven or non-woven fiber materials manufactured for use on construction, demolition, or other sites to prevent wind or water erosion of...

  4. 7 CFR 3201.68 - Erosion control materials.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Erosion control materials. 3201.68 Section 3201.68... Designated Items § 3201.68 Erosion control materials. (a) Definition. Woven or non-woven fiber materials manufactured for use on construction, demolition, or other sites to prevent wind or water erosion of...

  5. 7 CFR 3201.68 - Erosion control materials.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 15 2012-01-01 2012-01-01 false Erosion control materials. 3201.68 Section 3201.68... Designated Items § 3201.68 Erosion control materials. (a) Definition. Woven or non-woven fiber materials manufactured for use on construction, demolition, or other sites to prevent wind or water erosion of...

  6. Virginia Erosion and Sediment Control Handbook. Standards, Criteria and Guidelines.

    ERIC Educational Resources Information Center

    Virginia State Soil and Water Conservation Commission, Richmond, VA.

    Guidelines and technical standards for development of local erosion and sediment control programs and conservation standards to meet the goals established by the Virginia Erosion and Sediment Control law are presented in this handbook. Part I defines natural and manmade erosion, sedimentation, and the hazards of uncontrolled wear and damage to the…

  7. Urban Runoff: Model Ordinances for Erosion and Sediment Control

    EPA Pesticide Factsheets

    The model ordinance in this section borrows language from the erosion and sediment control ordinance features that might help prevent erosion and sedimentation and protect natural resources more fully.

  8. Estimation of sediment-discharge reduction for two sites of the Yazoo River basin demonstration erosion control project, north-central Mississippi, 1985-94

    USGS Publications Warehouse

    Rebich, R.A.

    1995-01-01

    Sediment-discharge reduction was estimated at two Demonstration Erosion Control sites in north-central Mississippi for the period 1985 through 1994. Decreasing trends were detected in flow-adjusted sediment discharge at Hotopha Creek near Batesville for the study period. The annual reduction in sediment discharge at this site was about 7 percent (0.68 ton per day per year). Decreasing trends were also detected in flow- adjusted sediment discharge at Otoucalofa Creek Canal near Water Valley for the study period. The annual reduction in sediment discharge at this site was about 11 percent (5.33 tons per day per year). The computations used to estimate sediment-discharge reduction were based on time series of instantaneous sediment discharges for the study period. Non-parametric procedures were used to compute trends in sediment discharge and to quantify reductions over time at the two sites. Parametric procedures were then used to verify the non-parametric results.

  9. Fallout radionuclide-based techniques for assessing the impact of soil conservation measures on erosion control and soil quality: an overview of the main lessons learnt under an FAO/IAEA Coordinated Research Project.

    PubMed

    Dercon, G; Mabit, L; Hancock, G; Nguyen, M L; Dornhofer, P; Bacchi, O O S; Benmansour, M; Bernard, C; Froehlich, W; Golosov, V N; Haciyakupoglu, S; Hai, P S; Klik, A; Li, Y; Lobb, D A; Onda, Y; Popa, N; Rafiq, M; Ritchie, J C; Schuller, P; Shakhashiro, A; Wallbrink, P; Walling, D E; Zapata, F; Zhang, X

    2012-05-01

    This paper summarizes key findings and identifies the main lessons learnt from a 5-year (2002-2008) coordinated research project (CRP) on "Assessing the effectiveness of soil conservation measures for sustainable watershed management and crop production using fallout radionuclides" (D1.50.08), organized and funded by the International Atomic Energy Agency through the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. The project brought together nineteen participants, from Australia, Austria, Brazil, Canada, Chile, China, Japan, Morocco, Pakistan, Poland, Romania, Russian Federation, Turkey, United Kingdom, United States of America and Vietnam, involved in the use of nuclear techniques and, more particularly, fallout radionuclides (FRN) to assess the relative impacts of different soil conservation measures on soil erosion and land productivity. The overall objective of the CRP was to develop improved land use and management strategies for sustainable watershed management through effective soil erosion control practices, by the use of ¹³⁷Cs (half-life of 30.2 years), ²¹⁰Pb(ex) (half-life of 22.3 years) and ⁷Be (half-life of 53.4 days) for measuring soil erosion over several spatial and temporal scales. The environmental conditions under which the different research teams applied the tools based on the use of fallout radionuclides varied considerably--a variety of climates, soils, topographies and land uses. Nevertheless, the achievements of the CRP, as reflected in this overview paper, demonstrate that fallout radionuclide-based techniques are powerful tools to assess soil erosion/deposition at several spatial and temporal scales in a wide range of environments, and offer potential to monitor soil quality. The success of the CRP has stimulated an interest in many IAEA Member States in the use of these methodologies to identify factors and practices that can enhance sustainable agriculture and minimize land degradation.

  10. Water Erosion Prediction Project (WEPP) model status and updates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This presentation will provide current information on the USDA-ARS Water Erosion Prediction Project (WEPP) model, and its implementation by the USDA-Forest Service (FS), USDA-Natural Resources Conservation Service (NRCS), and other agencies and universities. Most recently, the USDA-NRCS has begun ef...

  11. Geospatial application of the Water Erosion Prediction Project (WEPP) model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    At the hillslope profile and/or field scale, a simple Windows graphical user interface (GUI) is available to easily specify the slope, soil, and management inputs for application of the USDA Water Erosion Prediction Project (WEPP) model. Likewise, basic small watershed configurations of a few hillsl...

  12. Erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Erosion is the detachment of soil particles and transportation to another location. Wind erosion occurs when wind speed exceeds a critical threshold level, and loose soil particles or soil particles removed by abrasion then move in one of three ways: creep, saltation, and suspension. Erosion by wate...

  13. Weld overlay coatings for erosion control

    SciTech Connect

    Levin, B.; DuPont, J.N.; Marder, A.R.

    1993-03-03

    A literature review was made. In spite of similarities between abrasive wear and solid particle erosion, weld overlay hardfacing alloys that exhibit high abrasion resistance may not necessarily have good erosion resistance. The performance of weld overlay hardfacing alloys in erosive environments has not been studied in detail. It is believed that primary-solidified hard phases such as carbides and intermetallic compounds have a strong influence on erosion resistance of weld overlay hardfacing alloys. However, relationships between size, shape, and volume fraction of hard phases in a hardfacing alloys and erosion resistance were not established. Almost all hardfacing alloys can be separated into two major groups based upon chemical compositions of the primary solidified hard phases: (a) carbide hardening alloys (Co-base/carbide, WC-Co and some Fe base superalloys); and (b) intermetallic hardening alloys (Ni-base alloys, austenitic steels, iron-aluminides).

  14. Can control of soil erosion mitigate water pollution by sediments?

    PubMed

    Rickson, R J

    2014-01-15

    The detrimental impact of sediment and associated pollutants on water quality is widely acknowledged, with many watercourses in the UK failing to meet the standard of 'good ecological status'. Catchment sediment budgets show that hill slope erosion processes can be significant sources of waterborne sediment, with rates of erosion likely to increase given predicted future weather patterns. However, linking on-site erosion rates with off-site impacts is complicated because of the limited data on soil erosion rates in the UK and the dynamic nature of the source-pathway-receptor continuum over space and time. Even so, soil erosion control measures are designed to reduce sediment production (source) and mobilisation/transport (pathway) on hill slopes, with consequent mitigation of pollution incidents in watercourses (receptors). The purpose of this paper is to review the scientific evidence of the effectiveness of erosion control measures used in the UK to reduce sediment loads of hill slope origin in watercourses. Although over 73 soil erosion mitigation measures have been identified from the literature, empirical data on erosion control effectiveness are limited. Baseline comparisons for the 18 measures where data do exist reveal erosion control effectiveness is highly variable over time and between study locations. Given the limitations of the evidence base in terms of geographical coverage and duration of monitoring, performance of the different measures cannot be extrapolated to other areas. This uncertainty in effectiveness has implications for implementing erosion/sediment risk reduction policies, where quantified targets are stipulated, as is the case in the EU Freshwater Fish and draft Soil Framework Directives. Also, demonstrating technical effectiveness of erosion control measures alone will not encourage uptake by land managers: quantifying the costs and benefits of adopting erosion mitigation is equally important, but these are uncertain and difficult to

  15. Cloud forest restoration for erosion control in a Kichwa community of the Ecuadorian central Andes Mountains

    NASA Astrophysics Data System (ADS)

    Backus, L.; Giordanengo, J.; Sacatoro, I.

    2013-12-01

    The Denver Professional Chapter of Engineers Without Borders (EWB) has begun conducting erosion control projects in the Kichwa communities of Malingua Pamba in the Andes Mountains south of Quito, Ecuador. In many high elevation areas in this region, erosion of volcanic soils on steep hillsides (i.e., < 40%) is severe and often associated with roads, water supply systems, and loss of native cloud forests followed by burning and cultivation of food crops. Following a 2011 investigation of over 75 erosion sites, the multidisciplinary Erosion Control team traveled to Malingua Pamba in October 2012 to conduct final design and project implementation at 5 sites. In partnership with the local communities, we installed woody cloud forest species, grass (sig-sig) contour hedges, erosion matting, and rock structures (toe walls, plunge pools, bank armoring, cross vanes, contour infiltration ditches, etc.) to reduce incision rates and risk of slump failures, facilitate aggradation, and hasten revegetation. In keeping with the EWB goal of project sustainability, we used primarily locally available resources. High school students of the community grew 5000 native trees and some naturalized shrubs in a nursery started by the school principal, hand weavers produced jute erosion mats, and rocks were provided by a nearby quarry. Where possible, local rock was harvested from landslide areas and other local erosion features. Based on follow up reports and photographs from the community and EWB travelers, the approach of using locally available materials installed by the community is successful; plants are growing well and erosion control structures have remained in place throughout the November to April rainy season. The community has continued planting native vegetation at several additional erosion sites. Formal monitoring will be conducted in October 2013, followed by analysis of data to determine if induced meandering and other low-maintenance erosion control techniques are working

  16. The Streambank Erosion Control Evaluation and Demonstration Act of 1974, Section 32, Public Law 93-251. Appendix F. Yazoo River Basin Demonstration Projects.

    DTIC Science & Technology

    1981-12-01

    working upstream. This problem is compounded since the energy of the flow is concentrated at the overfall . As thesehead cuts move upstream, the...unconsolidated sand. The erosive energy of the flow is concentrated at the overfall . Headcuts are prevalent throughout the Yazoo Basin, and several...involved in simulating such conditions in process- based models. Failure occurs in reaches of 0 excessive energy expenditure typically associated with

  17. 76 FR 68745 - Notice of Intent To Update the Upland Erosion Control and Revegetation and Maintenance Plan and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-07

    ...-000] Notice of Intent To Update the Upland Erosion Control and Revegetation and Maintenance Plan and... the Office of Energy Projects is in the process of reviewing its Upland Erosion Control, Revegetation... Existing Regulations Under Part 157 and Related Sections of the Commission's Regulations Under the...

  18. Can we manipulate root system architecture to control soil erosion?

    NASA Astrophysics Data System (ADS)

    Ola, A.; Dodd, I. C.; Quinton, J. N.

    2015-03-01

    Soil erosion is a major threat to soil functioning. The use of vegetation to control erosion has long been a topic for research. Much of this research has focused on the above ground properties of plants, demonstrating the important role that canopy structure and cover plays in the reduction of water erosion processes. Less attention has been paid to plant roots. Plant roots are a crucial yet under-researched factor for reducing water erosion through their ability to alter soil properties, such as aggregate stability, hydraulic function and shear strength. However, there have been few attempts to manipulate plant root system properties to reduce soil erosion. Therefore, this review aims to explore the effects that plant roots have on soil erosion and hydrological processes, and how plant root architecture might be manipulated to enhance its erosion control properties. We clearly demonstrate the importance of root system architecture for the control of soil erosion. We also demonstrate that some plant species respond to nutrient enriched patches by increasing lateral root proliferation. The soil response to root proliferation will depend upon its location: at the soil surface dense mats of roots may block soil pores thereby limiting infiltration, enhancing runoff and thus erosion; whereas at depth local increases in shear strength may reinforce soils against structural failure at the shear plane. Additionally, in nutrient deprived regions, root hair development may be stimulated and larger amounts of root exudates released, thereby improving aggregate stability and decreasing erodibility. Utilising nutrient placement at depth may represent a potentially new, easily implemented, management strategy on nutrient poor agricultural land or constructed slopes to control erosion, and further research in this area is needed.

  19. Can we manipulate root system architecture to control soil erosion?

    NASA Astrophysics Data System (ADS)

    Ola, A.; Dodd, I. C.; Quinton, J. N.

    2015-09-01

    Soil erosion is a major threat to soil functioning. The use of vegetation to control erosion has long been a topic for research. Much of this research has focused on the above-ground properties of plants, demonstrating the important role that canopy structure and cover plays in the reduction of water erosion processes. Less attention has been paid to plant roots. Plant roots are a crucial yet under-researched factor for reducing water erosion through their ability to alter soil properties, such as aggregate stability, hydraulic function and shear strength. However, there have been few attempts to specifically manipulate plant root system properties to reduce soil erosion. Therefore, this review aims to explore the effects that plant roots have on soil erosion and hydrological processes, and how plant root architecture might be manipulated to enhance its erosion control properties. We demonstrate the importance of root system architecture for the control of soil erosion. We also show that some plant species respond to nutrient-enriched patches by increasing lateral root proliferation. The erosional response to root proliferation will depend upon its location: at the soil surface dense mats of roots may reduce soil erodibility but block soil pores thereby limiting infiltration, enhancing runoff. Additionally, in nutrient-deprived regions, root hair development may be stimulated and larger amounts of root exudates released, thereby improving aggregate stability and decreasing erodibility. Utilizing nutrient placement at specific depths may represent a potentially new, easily implemented, management strategy on nutrient-poor agricultural land or constructed slopes to control erosion, and further research in this area is needed.

  20. Controlling template erosion with advanced cleaning methods

    NASA Astrophysics Data System (ADS)

    Singh, SherJang; Yu, Zhaoning; Wähler, Tobias; Kurataka, Nobuo; Gauzner, Gene; Wang, Hongying; Yang, Henry; Hsu, Yautzong; Lee, Kim; Kuo, David; Dress, Peter

    2012-03-01

    We studied the erosion and feature stability of fused silica patterns under different template cleaning conditions. The conventional SPM cleaning is compared with an advanced non-acid process. Spectroscopic ellipsometry optical critical dimension (SE-OCD) measurements were used to characterize the changes in pattern profile with good sensitivity. This study confirmed the erosion of the silica patterns in the traditional acid-based SPM cleaning mixture (H2SO4+H2O2) at a rate of ~0.1nm per cleaning cycle. The advanced non-acid clean process however only showed CD shift of ~0.01nm per clean. Contamination removal & pattern integrity of sensitive 20nm features under MegaSonic assisted cleaning is also demonstrated.

  1. Environmental stochasticity controls soil erosion variability

    PubMed Central

    Kim, Jongho; Ivanov, Valeriy Y.; Fatichi, Simone

    2016-01-01

    Understanding soil erosion by water is essential for a range of research areas but the predictive skill of prognostic models has been repeatedly questioned because of scale limitations of empirical data and the high variability of soil loss across space and time scales. Improved understanding of the underlying processes and their interactions are needed to infer scaling properties of soil loss and better inform predictive methods. This study uses data from multiple environments to highlight temporal-scale dependency of soil loss: erosion variability decreases at larger scales but the reduction rate varies with environment. The reduction of variability of the geomorphic response is attributed to a ‘compensation effect’: temporal alternation of events that exhibit either source-limited or transport-limited regimes. The rate of reduction is related to environment stochasticity and a novel index is derived to reflect the level of variability of intra- and inter-event hydrometeorologic conditions. A higher stochasticity index implies a larger reduction of soil loss variability (enhanced predictability at the aggregated temporal scales) with respect to the mean hydrologic forcing, offering a promising indicator for estimating the degree of uncertainty of erosion assessments. PMID:26925542

  2. Environmental stochasticity controls soil erosion variability

    NASA Astrophysics Data System (ADS)

    Kim, Jongho; Ivanov, Valeriy Y.; Fatichi, Simone

    2016-03-01

    Understanding soil erosion by water is essential for a range of research areas but the predictive skill of prognostic models has been repeatedly questioned because of scale limitations of empirical data and the high variability of soil loss across space and time scales. Improved understanding of the underlying processes and their interactions are needed to infer scaling properties of soil loss and better inform predictive methods. This study uses data from multiple environments to highlight temporal-scale dependency of soil loss: erosion variability decreases at larger scales but the reduction rate varies with environment. The reduction of variability of the geomorphic response is attributed to a ‘compensation effect’: temporal alternation of events that exhibit either source-limited or transport-limited regimes. The rate of reduction is related to environment stochasticity and a novel index is derived to reflect the level of variability of intra- and inter-event hydrometeorologic conditions. A higher stochasticity index implies a larger reduction of soil loss variability (enhanced predictability at the aggregated temporal scales) with respect to the mean hydrologic forcing, offering a promising indicator for estimating the degree of uncertainty of erosion assessments.

  3. Climatic controls on the pace of glacier erosion

    NASA Astrophysics Data System (ADS)

    Koppes, Michele; Hallet, Bernard; Rignot, Eric; Mouginot, Jeremie; Wellner, Julia; Love, Katherine

    2016-04-01

    Mountain ranges worldwide have undergone large-scale modification due the erosive action of ice, yet the mechanisms that control the timing of this modification and the rate by which ice erodes remain poorly understood. Available data report a wide range of erosion rates from individual ice masses over varying timescales, suggesting that modern erosion rates exceed orogenic rates by 2-3 orders of magnitude. These modern rates are presumed to be due to dynamic acceleration of the ice masses during deglaciation and retreat. Recent numerical models have focused on replicating the processes that produce the geomorphic signatures of glacial landscapes. Central to these models is a simple quantitative index that relates erosion rate to ice dynamics and to climate. To provide such an index, we examined explicitly the factors controlling modern glacier erosion rates across climatic regimes. Holding tectonic history, bedrock lithology and glacier hypsometries relatively constant across a latitudinal transect from Patagonia to the Antarctic Peninsula, we find that modern, basin-averaged erosion rates vary by three orders of magnitude, from 1->10 mm yr-1 for temperate tidewater glaciers to 0.01-<0.1 mm yr-1 for polar outlet glaciers, largely as a function of temperature and basal thermal regime. Erosion rates also increase non-linearly with both the sliding speed and the ice flux through the ELA, in accord with theory. The general relationship between ice dynamics and erosion suggests that the erosion rate scales non-linearly with basal sliding speed, with an exponent n ≈ 2-2.62. Notably, erosion rates decrease by over two orders of magnitude between temperate and polar glaciers with similar ice discharge rates. The difference in erosion rates between temperate and colder glaciers of similar shape and size is primarily related to the abundance of meltwater accessing the bed. Since all glaciers worldwide have experienced colder than current climatic conditions, the 100-fold

  4. The Streambank Erosion Control Evaluation and Demonstration Act of 1974, Section 32, Public Law 93-251. Appendix E. Missouri River Demonstration Projects. Volume 1.

    DTIC Science & Technology

    1981-12-01

    Act of 1974 VISsOUut RvIM, caue DM To 1&U ohm, I -DA A INUCRATIUN g A. P2JECT ElMW AMD LOCII. Seventeen demonstration projects have been constructed ...evaluate the per- formance of the 17 Section 32 demonstration projects on the Missouri ’ River, between Garrison Dam and Lake Oahe, constructed and...of Garrison Dam which causes sizable fluctuation in daily releases, as discussed in subparagraph c. b. Construction Reference Plane. The Construction

  5. Soil erosion assessment and control in Northeast Wollega, Ethiopia

    NASA Astrophysics Data System (ADS)

    Adugna, A.; Abegaz, A.; Cerdà, A.

    2015-12-01

    Soil erosion is the main driver of land degradation in Ethiopia, and in the whole region of East Africa. This study was conducted at the Northeast Wollega in West Ethiopia to estimate the soil losses by means of the Revised Universal Soil Loss Equation (RUSLE). The purpose of this paper is to identify erosion spot areas and target locations for appropriate development of soil and water conservation measures. Fieldwork and household survey were conducted to identify major determinants of soil erosion control. Six principal factors were used to calculate soil loss per year, such as rainfallerosivity, soil erodiblity, slope length, slope steepness, crop management and erosion-control practices. The soil losses have shown spatio-temporal variations that range from 4.5 Mg ha-1 yr-1 in forest to 65.9 Mg ha-1 yr-1 in cropland. Results from the analysis of stepwise multiple linear regression show that sustainable soil erosion control are determined byknowledge of farmers about soil conservation, land tenure security and off-farm income at community level. Thus, policy aim at keeping land productivity will need to focus on terracing, inter-cropping and improved agro-forestry practices.

  6. CO₂ laser emission modes to control enamel erosion.

    PubMed

    Scatolin, Renata Siqueira; Alonso-Filho, Fernando Luiz; Galo, Rodrigo; Rios, Daniela; Borsatto, Maria Cristina; Corona, Silmara Aparecida Milori

    2015-08-01

    Considering the importance and prevalence of dental erosion, the aim of this in vitro study was to evaluate the influence of different modes of pulse emission of CO2 laser associated or not to acidulated phosphate fluoride (APF) 1.23% gel, in controlling enamel erosion by profilometry. Ninety-six fragments of bovine enamel were flattened and polished, and the specimens were subjected to initial erosive challenge with hydrochloric acid (pH = 2). Specimens were randomly assigned according to surface treatment: APF 1.23% gel and gel without fluoride (control), and subdivided according to the modes of pulse CO2 laser irradiation: no irradiation (control), continuous, ultrapulse, and repeated pulse (n = 12). After surface treatment, further erosive challenges were performed for 5 days, 4 × 2 min/day. Enamel structure loss was quantitatively determined by a profilometer, after surface treatment and after 5 days of erosive challenges. Two-away ANOVA revealed a significant difference between the pulse emission mode of the CO2 laser and the presence of fluoride (P ≤ 0.05). The Duncan's test showed that CO2 laser irradiation in continuous mode and the specimens only received fluoride, promoted lower enamel loss than that other treatments. A lower dissolution of the enamel prisms was observed when it was irradiated with CO2 laser in continuous mode compared other groups. It can be concluded that CO2 laser irradiation in continuous mode was the most effective to control the enamel structure loss submitted to erosive challenges with hydrochloric acid.

  7. Geologic controls of erosion and sedimentation on Mars

    NASA Technical Reports Server (NTRS)

    Tanaka, K. L.; Dohm, J. M.; Carr, M. H.

    1993-01-01

    Because Mars has had a history of diverse erosional and depositional styles, a variety of erosional landforms and sedimentary deposits can be seen on Viking orbiter images. Here we review how geologic processes involving rock, water, and structure have controlled erosion and sedimentation on Mars. Additionally, we review how further studies will help refine our understanding of these processes.

  8. LONG-TERM EVALUATION OF REGIONAL EROSION CONTROL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Under legislation passed in 1984, three federal agencies constructed more than $300 million worth of channel erosion control measures in 16 watersheds in northern Mississippi between 1985 and 2003. Most work was completed between 1985 and 1995, and was confined to six larger watersheds. Flows of w...

  9. Use of palm-mat geotextiles for rainsplash erosion control

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, R.; Fullen, M. A.; Davies, K.; Booth, C. A.

    2010-07-01

    Soil detachment by raindrop action (rainsplash erosion) is a very important subprocess of erosion by water. It is a particular problem in the UK as most soils are sandy or loamy sand in texture and lands have gentle to medium slope. However, few studies report potential rainsplash erosion control options under field conditions. Hence, the utilization of palm-mat geotextiles as a rainsplash erosion control technique was investigated at Hilton, east Shropshire, U.K. (52°33'5.7″ N, 2°19'18.3″ W). Geotextile-mats constructed from Borassus aethiopum (Borassus palm of West Africa) and Mauritia flexuosa (Buriti palm of South America) leaves are termed Borassus mats and Buriti mats, respectively. Two-year field experiments were conducted at Hilton to study the effects of emplacing Borassus and Buriti mats on rainsplash erosion of a loamy sand soil. Two sets (12 plots each) of experiments were established to study the effects of these mats on splash height and splash erosion. Splash height needs to be known to assess the transport mechanism of major soil fraction and its constituents on sloping land by rainsplash. In both sets, six randomly-selected plots were covered with mats, and the rest were bare. Results (during 22/01/2007‒23/01/2009; total precipitation = 1731.5 mm) show that Borassus mat-covered plots had ˜ 89% ( P < 0.001) less total splash erosion (2.97 kg m - 2 ) than bare plots (27.02 kg m - 2 ). Comparatively, mean splash height from Borassus mat-covered plots (0.12 m) was significantly ( P < 0.001) less than the bare plots, by ˜ 54%. However, Buriti mat-cover on bare plots had no significant ( P > 0.05) effect in rainsplash erosion control during that period, although plots with Buriti mats significantly ( P < 0.05) decreased splash height (by ˜ 18%) compared with bare plots (0.26 m). Buriti mats, probably due to their ˜ 43, 62 and 50% lower cover percentage (44%), mass per unit area (413 g - 2 ) and thickness (10 mm), respectively, compared with

  10. Demonstration of the Water Erosion Prediction Project (WEPP) internet interface and services

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Water Erosion Prediction Project (WEPP) model is a process-based FORTRAN computer simulation program for prediction of runoff and soil erosion by water at hillslope profile, field, and small watershed scales. To effectively run the WEPP model and interpret results additional software has been de...

  11. Does control of soil erosion inhibit aquatic eutrophication?

    PubMed

    Ekholm, Petri; Lehtoranta, Jouni

    2012-01-01

    Much of the phosphorus (P) from erosive soils is transported to water bodies together with eroded soil. Studies clarifying the impact of soil erosion on eutrophication have sought largely to quantify the reserves of P in soil particles that can be desorbed in different types of receiving waters. Aquatic microbiology has revealed that the cycling of P is coupled to the availability of common electron acceptors, Fe oxides and SO₄, through anaerobic mineralization in sediments. Eroded soil is also rich in Fe oxides, and their effect on the coupled cycling of C, Fe, S, and P has been neglected in eutrophication research. Soil erosion, and its control, should therefore be studied by considering not only the processes occurring in the water phase but also those taking place after the soil particles have settled to the bottom. We propose that in SO₄-rich systems, Fe oxides transported by eroded soil may promote Fe cycling, inhibit microbial SO₄ reduction and maintain the ability of sediment to retain P. We discuss the mechanisms through which eroded soil may affect benthic mineralization processes and the manner in which soil erosion may contribute to or counteract eutrophication.

  12. Plume Mitigation: Soil Erosion and Lunar Prospecting Sensor Project

    NASA Technical Reports Server (NTRS)

    Metzger, Philip T.

    2014-01-01

    Demonstrate feasibility of the simplest, lowest-mass method of measuring density of a cloud of lunar soil ejected by rocket exhaust, using new math techniques with a small baseline laser/camera system. Focus is on exploring the erosion process that occurs when the exhaust plume of a lunar rocket impacts the regolith. Also, predicting the behavior of the lunar soil that would be blasted from a lunar landing/launch site shall assist in better design and protection of any future lunar settlement from scouring of structures and equipment. NASA is gathering experimental data to improve soil erosion models and understand how lunar particles enter the plume flow.

  13. 48 CFR 436.574 - Control of erosion, sedimentation, and pollution.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Control of erosion... 436.574 Control of erosion, sedimentation, and pollution. The contracting officer shall insert the clause at 452.236-74, Control of Erosion, Sedimentation and Pollution, if there is a need for...

  14. 48 CFR 436.574 - Control of erosion, sedimentation, and pollution.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 4 2013-10-01 2013-10-01 false Control of erosion... 436.574 Control of erosion, sedimentation, and pollution. The contracting officer shall insert the clause at 452.236-74, Control of Erosion, Sedimentation and Pollution, if there is a need for...

  15. 48 CFR 436.574 - Control of erosion, sedimentation, and pollution.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 4 2014-10-01 2014-10-01 false Control of erosion... 436.574 Control of erosion, sedimentation, and pollution. The contracting officer shall insert the clause at 452.236-74, Control of Erosion, Sedimentation and Pollution, if there is a need for...

  16. 48 CFR 452.236-74 - Control of Erosion, Sedimentation, and Pollution.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 4 2013-10-01 2013-10-01 false Control of Erosion....236-74 Control of Erosion, Sedimentation, and Pollution. As prescribed in 436.574, insert the following clause: Control of Erosion, Sedimentation, and Pollution (NOV 1996) (a) Operations shall...

  17. 48 CFR 452.236-74 - Control of Erosion, Sedimentation, and Pollution.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Control of Erosion....236-74 Control of Erosion, Sedimentation, and Pollution. As prescribed in 436.574, insert the following clause: Control of Erosion, Sedimentation, and Pollution (NOV 1996) (a) Operations shall...

  18. 48 CFR 436.574 - Control of erosion, sedimentation, and pollution.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Control of erosion... 436.574 Control of erosion, sedimentation, and pollution. The contracting officer shall insert the clause at 452.236-74, Control of Erosion, Sedimentation and Pollution, if there is a need for...

  19. 48 CFR 452.236-74 - Control of Erosion, Sedimentation, and Pollution.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Control of Erosion....236-74 Control of Erosion, Sedimentation, and Pollution. As prescribed in 436.574, insert the following clause: Control of Erosion, Sedimentation, and Pollution (NOV 1996) (a) Operations shall...

  20. 48 CFR 436.574 - Control of erosion, sedimentation, and pollution.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 4 2012-10-01 2012-10-01 false Control of erosion... 436.574 Control of erosion, sedimentation, and pollution. The contracting officer shall insert the clause at 452.236-74, Control of Erosion, Sedimentation and Pollution, if there is a need for...

  1. 48 CFR 452.236-74 - Control of Erosion, Sedimentation, and Pollution.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 4 2014-10-01 2014-10-01 false Control of Erosion....236-74 Control of Erosion, Sedimentation, and Pollution. As prescribed in 436.574, insert the following clause: Control of Erosion, Sedimentation, and Pollution (NOV 1996) (a) Operations shall...

  2. 48 CFR 452.236-74 - Control of Erosion, Sedimentation, and Pollution.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 4 2012-10-01 2012-10-01 false Control of Erosion....236-74 Control of Erosion, Sedimentation, and Pollution. As prescribed in 436.574, insert the following clause: Control of Erosion, Sedimentation, and Pollution (NOV 1996) (a) Operations shall...

  3. 18 CFR 1304.202 - General sediment and erosion control provisions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... erosion control provisions. 1304.202 Section 1304.202 Conservation of Power and Water Resources TENNESSEE... OTHER ALTERATIONS TVA-Owned Residential Access Shoreland § 1304.202 General sediment and erosion control provisions. (a) During construction activities, TVA shall require that appropriate erosion and...

  4. 18 CFR 1304.202 - General sediment and erosion control provisions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... erosion control provisions. 1304.202 Section 1304.202 Conservation of Power and Water Resources TENNESSEE... OTHER ALTERATIONS TVA-Owned Residential Access Shoreland § 1304.202 General sediment and erosion control provisions. (a) During construction activities, TVA shall require that appropriate erosion and...

  5. 18 CFR 1304.202 - General sediment and erosion control provisions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... erosion control provisions. 1304.202 Section 1304.202 Conservation of Power and Water Resources TENNESSEE... OTHER ALTERATIONS TVA-Owned Residential Access Shoreland § 1304.202 General sediment and erosion control provisions. (a) During construction activities, TVA shall require that appropriate erosion and...

  6. 18 CFR 1304.202 - General sediment and erosion control provisions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... erosion control provisions. 1304.202 Section 1304.202 Conservation of Power and Water Resources TENNESSEE... OTHER ALTERATIONS TVA-Owned Residential Access Shoreland § 1304.202 General sediment and erosion control provisions. (a) During construction activities, TVA shall require that appropriate erosion and...

  7. 18 CFR 1304.202 - General sediment and erosion control provisions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... erosion control provisions. 1304.202 Section 1304.202 Conservation of Power and Water Resources TENNESSEE... OTHER ALTERATIONS TVA-Owned Residential Access Shoreland § 1304.202 General sediment and erosion control provisions. (a) During construction activities, TVA shall require that appropriate erosion and...

  8. Control of Eolian soil erosion from waste site surface barriers

    SciTech Connect

    Ligotke, M.W.

    1994-11-01

    Physical models were tested in a wind tunnel to determine optimum surface-ravel admixtures for protecting silt-loam soil from erosion by, wind and saltating, sand stresses. The tests were performed to support the development of a natural-material surface barrier for and waste sites. Plans call for a 2-m deep silt-loam soil reservoir to retain infiltrating water from rainfall and snowmelt. The objective of the study was to develop a gravel admixture that would produce an erosion-resistant surface layer during, periods of extended dry climatic stress. Thus, tests were performed using simulated surfaces representing dry, unvegetated conditions present just after construction, after a wildfire, or during an extended drought. Surfaces were prepared using silt-loam soil mixed with various grades of sand and Travel. Wind-induced surface shear stresses were controlled over the test surfaces, as were saltating, sand mass flow rates and intensities. Tests were performed at wind speeds that approximated and exceeded local 100-year peak gust intensities. Surface armors produced by pea gravel admixtures were shown to provide the best protection from wind and saltating sand stresses. Compared with unprotected silt-loam surfaces, armored surfaces reduced erosion rates by more than 96%. Based in part on wind tunnel results, a pea gravel admixture of 15% will be added to the top 1 in of soil in a prototype barrier under construction in 1994. Field tests are planned at the prototype site to provide data for comparison with wind tunnel results.

  9. Global carbon export from the terrestrial biosphere controlled by erosion.

    PubMed

    Galy, Valier; Peucker-Ehrenbrink, Bernhard; Eglinton, Timothy

    2015-05-14

    Riverine export of particulate organic carbon (POC) to the ocean affects the atmospheric carbon inventory over a broad range of timescales. On geological timescales, the balance between sequestration of POC from the terrestrial biosphere and oxidation of rock-derived (petrogenic) organic carbon sets the magnitude of the atmospheric carbon and oxygen reservoirs. Over shorter timescales, variations in the rate of exchange between carbon reservoirs, such as soils and marine sediments, also modulate atmospheric carbon dioxide levels. The respective fluxes of biospheric and petrogenic organic carbon are poorly constrained, however, and mechanisms controlling POC export have remained elusive, limiting our ability to predict POC fluxes quantitatively as a result of climatic or tectonic changes. Here we estimate biospheric and petrogenic POC fluxes for a suite of river systems representative of the natural variability in catchment properties. We show that export yields of both biospheric and petrogenic POC are positively related to the yield of suspended sediment, revealing that POC export is mostly controlled by physical erosion. Using a global compilation of gauged suspended sediment flux, we derive separate estimates of global biospheric and petrogenic POC fluxes of 157(+74)(-50) and 43(+61)(-25) megatonnes of carbon per year, respectively. We find that biospheric POC export is primarily controlled by the capacity of rivers to mobilize and transport POC, and is largely insensitive to the magnitude of terrestrial primary production. Globally, physical erosion rates affect the rate of biospheric POC burial in marine sediments more strongly than carbon sequestration through silicate weathering. We conclude that burial of biospheric POC in marine sediments becomes the dominant long-term atmospheric carbon dioxide sink under enhanced physical erosion.

  10. Erosion control at construction sites on red clay soils

    NASA Astrophysics Data System (ADS)

    Lemly, A. Dennis

    1982-07-01

    Five single-treatment methods used to stabilize seeded areas at urban and highway construction sites (asphalt-tacked straw, jute netting, mulch blanket, wood chips, excelsior blanket) were tested for their ability to control erosion of red clay soils by comparisons with exposed sites and multiple treatments. Sediment in runoff from experimental plots was characterized during low and high intensity precipitation from natural rainfall episodes during April, May, and June. Reductions in the total sediment concentration of runoff ranged from 28 percent (asphalt-tacked straw, 50 percent slope) to 90 percent (multiple treatments, 40 percent slope), with ≥85 percent of the eroded material composed of particles <0.04 mm in diameter. Larger size fractions were effectively reduced by all treatments tested regardless of slope (≥70 percent decrease). Established grass cover exceeded 90 percent on all plots after 60 days, but sediment release remained similar, attributable to high intensity rainfall, poor establishment of root systems, and piping on plots treated with tacked straw or jute netting. Results indicate that current stabilization methods shift sediment compostion toward a smaller particle size, causing single treatments to be minimally effective for controlling erosion of the major component of red clay soils. Because small particles have the greatest direct effect on aquatic biota, certain impacts of sedimentation may not be measurably lessened by single treatments in regions where red clays predominate even though the total sediment load is reduced by as much as 75 percent. Clearly, a multiple-treatment approach offers significantly greater control of erosion on red clay soils, however, current economic and construction policy represents a substantial deterrent to implementation.

  11. Field studies of beach cones as coastal erosion control/reversal devices for areas with significant oil and gas activities. Technical progress report, April--June 1992 and Project status report, June 1992

    SciTech Connect

    Not Available

    1992-07-17

    A field demonstration/study of a novel shoreline erosion protection device called beach cones is planned. These patented, fiberglass- reinforced concreted devices are to be deployed in a number of geometric patterns at seven location in the Bastian Bay area of Western Plaquemines Parish. The purpose of the work described in this report was to evaluate the proposed study`s impact on living and non-living shellfish resources within each of the project`s seven separate Study Areas. Major accomplishments for this reporting period were as follows: aerial photographs of the experimental sites were taken; all permit applications were filed; information was submitted for the Environmental Report; several reconnaissance trips to the experimental sites were made; meetings were held among all participating organizations to further plan the research; permit was obtained from the US Army Corps of Engineers; test sites were surveyed by the Xavier University contingent; survey data were taken at all sites; the Oyster Assessment was completed; permit was obtained from the State of Louisiana Department of Natural Resources; and initial survey data were finalized at all sites.

  12. Projected rainfall erosivity changes under climate change from multimodel and multiscenario projections in Northeast China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Future changes in precipitation will induce changes in the erosive power of rainfall and hence changes in soil erosion rates. In this study we calculated downscaled mean annual precipitation and USLE rainfall erosivity (R) for time periods 2030 through 2059 and 2070 through 2099 in Northeast China u...

  13. Current projects in Fuzzy Control

    NASA Technical Reports Server (NTRS)

    Sugeno, Michio

    1990-01-01

    Viewgraphs on current projects in fuzzy control are presented. Three projects on helicopter flight control are discussed. The projects are (1) radio control by oral instructions; (2) automatic autorotation entry in engine failure; and (3) unmanned helicopter for sea rescue.

  14. No-till spring barley to control wind erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind erosion is a major concern for growers and communities in the Pacific Northwest. Wind erosion not only degrades the soil resource which can affect the long-term productivity of agricultural lands, but it also degrades air quality in the region. Continuous no-till spring cereal cropping systems ...

  15. Buhne Point Shoreline Erosion Demonstration Project. Volume 2. Appendices E.

    DTIC Science & Technology

    1987-08-01

    APPENDIX A Cost Estimates B Wave Data Statistics C Wind Data 3tatistics D Plates From F’revicus U.b. Corps Reports E Concfiptual Plens of Alternatc...4 3 Project Layout, Plan A ....................... 6 4 Typical Wave Pattern. Buhne Spit ........ 10 PLATES : Page I Local Wind...8217.CTION,HEIGHT B PERIOD to WIND rREQUENCY Ii DlS7ftiVa~lQd AOSW JULY 1939-OEC1,42UfiC *EATHqCaLUflCM gTA J*i~eeDC ~Y~tOD~avP PLATE I - P6 v:c-a ,nr

  16. Beach erosion control study at Pass Christian. [using remote sensors and satellite observation

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The methods of measuring the existence of erosion and the effects of sand stabilization control systems are described. The mechanics of sand movement, the nature of sand erosion, and the use of satellite data to measure these factors and their surrogates are discussed using the locational and control aspects of aeolian and litoral erosion zones along the sand beach of the Mississippi coast. The aeolian erosion is highlighted due to the redeposition of the sand which causes high cleanup costs, property damage, and safety and health hazards. The areas of differential erosion and the patterns of beach sand movement are illustrated and the use of remote sensing methods to identify the areas of erosion are evaluated.

  17. Device Oriented Project Controller

    SciTech Connect

    Dalesio, Leo; Kraimer, Martin

    2013-11-20

    This proposal is directed at the issue of developing control systems for very large HEP projects. A de-facto standard in accelerator control is the Experimental Physics and Industrial Control System (EPICS), which has been applied successfully to many physics projects. EPICS is a channel based system that requires that each channel of each device be configured and controlled. In Phase I, the feasibility of a device oriented extension to the distributed channel database was demonstrated by prototyping a device aware version of an EPICS I/O controller that functions with the current version of the channel access communication protocol. Extensions have been made to the grammar to define the database. Only a multi-stage position controller with limit switches was developed in the demonstration, but the grammar should support a full range of functional record types. In phase II, a full set of record types will be developed to support all existing record types, a set of process control functions for closed loop control, and support for experimental beam line control. A tool to configure these records will be developed. A communication protocol will be developed or extensions will be made to Channel Access to support introspection of components of a device. Performance bench marks will be made on both communication protocol and the database. After these records and performance tests are under way, a second of the grammar will be undertaken.

  18. Glaciation's topographic control on Holocene erosion at the eastern edge of the Alps

    NASA Astrophysics Data System (ADS)

    Dixon, Jean L.; von Blanckenburg, Friedhelm; Stüwe, Kurt; Christl, Marcus

    2016-12-01

    What is the influence of glacial processes in driving erosion and uplift across the European Alps? It has largely been argued that repeated erosion and glaciation sustain isostatic uplift and topography in a decaying orogen. But some parts of the Alps may still be actively uplifting via deep lithospheric processes. We add insight to this debate by isolating the role of post-glacial topographic forcing on erosion rates. To do this, we quantify the topographic signature of past glaciation on millennial-scale erosion rates in previously glaciated and unglaciated catchments at the easternmost edge of the Austrian Alps. Newly measured catchment-wide erosion rates, determined from cosmogenic 10Be in river-borne quartz, correlate with basin relief and mean slope. GIS-derived slope-elevation and slope-area distributions across catchments provide clear topographic indicators of the degree of glacial preconditioning, which further correlates with erosion rates. Erosion rates in the easternmost, non-glaciated basins range from 40 to 150 mm ky-1 and likely reflect underlying tectonic forcings in this region, which have previously been attributed to recent (post 5 Ma) uplift. By contrast, erosion rates in previously glaciated catchments range from 170 to 240 mm ky-1 and reflect the erosional response to local topographic preconditioning by repeated glaciations. Together, these data suggest that Holocene erosion across the Eastern Alps is strongly shaped by the local topography relict from previous glaciations. Broader, landscape-wide forcings, such as the widely debated deep mantle-driven or isostatically driven uplift, result in lesser controls on both topography and erosion rates in this region. Comparing our data to previously published erosion rates across the Alps, we show that post-glacial erosion rates vary across more than 2 orders of magnitude. This high variation in post-glacial erosion may reflect combined effects of direct tectonic and modern climatic forcings but

  19. Robotic weld overlay coatings for erosion control. Quarterly technical progress report, January 1993--March 1993

    SciTech Connect

    Levin, B.F.; Dupont, J.N.; Marder, A.R.

    1993-04-18

    Twelve weld overlay hardfacing alloys have been selected for preliminary erosion testing based on a literature review These alloys have been separated into three major groups: (1) Cobalt containing alloys, (2) Nickel-base alloys, (3) Iron base alloys. These alloys are being applied to carbon steel substrates and will undergo preliminary erosion testing to identify candidates weld overlay alloys for erosion control in CFB boilers. The candidate alloys selected from the preliminary erosion tests will then undergo more detailed evaluations in future research.

  20. Quantitative evaluation of strategies for erosion control on a railway embankment batter

    NASA Astrophysics Data System (ADS)

    Gyasi-Agyei, Y.; Sibley, J.; Ashwath, N.

    2001-12-01

    Strategies for erosion control on a railway embankment batter (side slope) are quantitatively evaluated in this paper. The strategies were centred on control (do nothing treatment), grass seeding, gypsum application, jute mat (an erosion control blanket) placement and planting hedgerows of Monto vetiver grass. Rainfall and runoff were monitored at 1 min intervals on 10 m wide embankment batter plots during 1998 and 1999. Total bedload and suspended sediment eroded from the plots were also measured but only for a group of storm events within sampling intervals. It has been demonstrated that vetiver grass is not cost-effective in controlling erosion on railway batters within Central Queensland region. Seeding alone could cause 60% reduction in the erosion rate compared with the control treatment. Applying gypsum to the calcium-deficient soil before seeding yielded an additional 25% reduction in the erosion rate. This is the result, primarily, of 100% grass cover establishment within seven months of sowing. Therefore, for railway embankment batter erosion control, the emphasis needs to be on rapid establishment of 100% grass cover. For rapid establishment of grass cover, irrigation is necessary during the initial stages of growth as the rainfall is unpredictable and the potential evaporation exceeds rainfall in the study region. The risk of seeds and fertilizers being washed out by short-duration and high-intensity rainfall events during the establishment phase may be reduced by the use of erosion control blankets on sections of the batters. Accidental burning of grasses on some plots caused serious erosion problems, resulting in very slow recovery of grass growth. It is therefore recommended that controlled burning of grasses on railway batters should be avoided to protect batters from being exposed to severe erosion.

  1. The contribution of mulches to control high soil erosion rates in vineyards in Eastern Spain

    NASA Astrophysics Data System (ADS)

    Cerdà, Artemi; Jordán, Antonio; Zavala, Lorena; José Marqués, María; Novara, Agata

    2014-05-01

    Soil erosion take place in degraded ecosystem where the lack of vegetation, drought, erodible parent material and deforestation take place (Borelli et al., 2013; Haregeweyn et al., 2013; Zhao et al., 2013). Agriculture management developed new landscapes (Ore and Bruins, 2012) and use to trigger non-sustainable soil erosion rates (Zema et al., 2012). High erosion rates were measured in agriculture land (Cerdà et al., 2009), but it is also possible to develop managements that will control the soil and water losses, such as organic amendments (Marqués et al., 2005), plant cover (Marqués et al., 2007) and geotextiles (Giménez Morera et al., 2010). The most successful management to restore the structural stability and the biological activity of the agriculture soil has been the organic mulches (García Orenes et al; 2009; 2010; 2012). The straw mulch is also very successful on bare fire affected soil (Robichaud et al., 2013a; 2013b), which also contributes to a more stable soil moisture content (García-Moreno et al., 2013). The objective of this research is to determine the impact of two mulches: wheat straw and chipped branches, on the soil erosion rates in a rainfed vineyard in Eastern Spain. The research site is located in the Les Alcusses Valley within the Moixent municipality. The Mean annual temperature is 13 ºC, and the mean annual rainfall 455 mm. Soil are sandy loam, and are developed at the foot-slope of a Cretaceous limestone range, the Serra Grossa range. The soils use to be ploughed and the features of soil erosion are found after each thunderstorm. Rills are removed by ploughing. Thirty rainfall simulation experiments were carried out in summer 2011 during the summer drought period. The simulated rainfall lasted during 1 hour at a 45 mmh-1 intensity on 1 m2 plots (Cerdà and Doerr, 2010; Cerdà and Jurgensen 2011). Ten experiments were carried out on the control plots (ploughed), 10 on straw mulch covered plots, and 10 on chipped branches covered

  2. Precise spatial control of cavitation erosion in a vessel phantom by using an ultrasonic standing wave.

    PubMed

    Shi, Aiwei; Huang, Peixuan; Guo, Shifang; Zhao, Lu; Jia, Yingjie; Zong, Yujin; Wan, Mingxi

    2016-07-01

    In atherosclerotic inducement in animal models, the conventionally used balloon injury is invasive, produces excessive vessel injuries at unpredictable locations and is inconvenient in arterioles. Fortunately, cavitation erosion, which plays an important role in therapeutic ultrasound in blood vessels, has the potential to induce atherosclerosis noninvasively at predictable sites. In this study, precise spatial control of cavitation erosion for superficial lesions in a vessel phantom was realised by using an ultrasonic standing wave (USW) with the participation of cavitation nuclei and medium-intensity ultrasound pulses. The superficial vessel erosions were restricted between adjacent pressure nodes, which were 0.87 mm apart in the USW field of 1 MHz. The erosion positions could be shifted along the vessel by nodal modulation under a submillimetre-scale accuracy without moving the ultrasound transducers. Moreover, the cavitation erosion of the proximal or distal wall could be determined by the types of cavitation nuclei and their corresponding cavitation pulses, i.e., phase-change microbubbles with cavitation pulses of 5 MHz and SonoVue microbubbles with cavitation pulses of 1 MHz. Effects of acoustic parameters of the cavitation pulses on the cavitation erosions were investigated. The flow conditions in the experiments were considered and discussed. Compared to only using travelling waves, the proposed method in this paper improves the controllability of the cavitation erosion and reduces the erosion depth, providing a more suitable approach for vessel endothelial injury while avoiding haemorrhage.

  3. The South Carolina Coastal Erosion Study: Integrated Circulation and Sediment Transport Studies. A Project Overview.

    NASA Astrophysics Data System (ADS)

    Voulgaris, G.; Warner, J. C.; Work, P. A.; Hanes, D. M.; Haas, K. A.

    2004-12-01

    The South Carolina Coastal Erosion Study (SCCES) is a cooperative research program funded by the U.S. Geological Survey Coastal and Marine Geology Program and managed by the South Carolina Sea Grant Consortium. The main objective of the study is to understand the factors and processes that control coastal sediment movement along the northern part of the South Carolina coast while at the same time advance our basic understanding of circulation, wave propagation and sediment transport processes. Earlier geological framework studies carried out by the same program provided detailed data on bathymetry, bottom sediment thickness and grain size distribution. They identified an extensive (10km long, 2km wide) sand body deposit located in the inner shelf that has potential use for beach nourishment. The main objectives are to: (1) identify the role of wind-driven circulation in controlling regional sediment distribution on the SC shelf; (2) examine the hypothesis that the shoal is of the "fair-weather type" with bedload being the dominant sediment transport mode and the tidally-averaged flow being at different directions at the two flanks of the shoal; (3) investigate the possibility that the sediment source for the shoal is derived from the nearshore as the result of the convergence of the longshore sediment transport; and finally, (4) quantify the control that the shoal exerts on the nearshore conditions through changes on the wave energy propagation characteristics. Field measurements and numerical modeling techniques are utilized in this project. Two deployments of oceanographic and sediment transport systems took place for a period of 6 months (October 2003 to April 2004) measuring wind forcing, vertical distribution of currents, stratification, and wave spectral characteristics. Further, bed-flow interactions were measured at two locations, with instrumented tripods equipped with pairs of ADVs for measuring turbulence, PC-ADPs for measuring vertical current profiles

  4. Control of water erosion and sediment in open cut coal mines in tropical areas

    SciTech Connect

    Ueda, T.; Nugraha, C.; Matsui, K.; Shimada, H.; Ichinose, M.; Gottfried, J.

    2005-07-01

    The purpose is to reduce the environmental impacts from open cut mining in tropical areas, such as Indonesia and Vietnam. Research conducted on methods for the control of water erosion and sediment from open cut coal mines is described. Data were collected on climate and weathering in tropical areas, mechanism of water erosion and sedimentation, characteristics of rocks in coal measures under wet conditions, water management at pits and haul roads and ramps, and construction of waste dumps and water management. The results will be applied to the optimum control and management of erosion and sediments in open cut mining. 6 refs., 8 figs.

  5. Integrating Phosphorus Movement with Soil and Water Loss in the Daily Erosion Project

    NASA Astrophysics Data System (ADS)

    Sklenar, Tim; Perez-Bidegain, Mario; Cruse, Richard; Gelder, Brian; Herzmann, Daryl

    2016-04-01

    The Daily Erosion Project (DEP) is an ongoing modelling effort which is now in its second generation. DEP provides comprehensive and dynamic estimates of sediment delivery, soil erosion, and hill slope runoff for agricultural land areas across the Midwestern United States every day for Hydrologic Unit Code 12 (HUC 12) size watersheds. Results are posted every morning on the Internet at dailyerosion.org. Currently DEP covers all of Iowa and portions of Kansas and Minnesota, but expansion of coverage is ongoing. The integration of highly resolute spatial and temporal climate data, soil properties, crop rotation and residue management data affords the opportunity to test the effects of using multiple conservation practices on the transport and fate of water borne nutrients, especially phosphorus, on the Midwestern United States agricultural landscapes. Understanding the interaction of different environmental and land management practices on phosphorus movement will allow data from the DEP to guide conservation efforts as expansion continues into surrounding Midwestern states. The presentation will provide an overview of the DEP technology, including how input data are derived and used to make daily erosion estimates on over 200,000 flowpaths in the modelling area, as well as a discussion of the ongoing phosphorus transport modelling efforts and plans for future expansion (both land area and model functionality).

  6. Cover crops effectiveness for soil erosion control in Sicilian vineyard

    NASA Astrophysics Data System (ADS)

    Gristina, L.; Novara, A.; Saladino, S.; Santoro, A.

    2009-04-01

    In vineyards, which are very common in Mediterranean area, cover crops are becoming increasingly used to reduce soil erosion. Cover crops reduce runoff by increasing infiltration and increasing roughness and then reducing the ovelandflow velocity. The aim of the present study was to quantify soil and water losses under different soil managements systems on vineyards. The study site was a Sauvignon blanc winegrape vineyard located in Southwestern Sicily. Vineyards were managed both traditionally (conventional tillage) and alternative management using cover crops: 1) Vicia faba ; 2) Vicia faba and Vicia sativa; 3) Trifolium subterraneum, Lolium perenne, Festuca rubra; 4)Trifolium subterraneum, Festuca rubra and Festuca ovina, 5) Triticum durum, 6) Triticum durum and Vicia sativa. To monitor water and sediment yield, a Gerlach trough was installed at each treatment on the vineyard inter-row, with the row vineyard used as a border (topographical border). Runoff was measured after each rainfall event (raingauge 0.2 mm accuracy) from November 2005 to April 2007. And sediments were measured after desiccation. The results show that runoff and erosion were reduced considerably under the treatments with Trifolium subterraneum, Lolium perenne, Festuca rubra and Trifolium subterraneum, Festuca rubra and Festuca ovina (treatments 3 and 4). The soil losses were reduced by 73% under treatment 4 compared to the tillage plot. Conventional tillage and alternative management using Vicia faba cover crop (treatment 1) result the most ineffective treatment to soil erosion. These results show that the use of a cover crop can be a simple soil and water conservation practice in Sicilian vineyards. Key words: soil erosion, cover crops, vineyard, Mediterranean area.

  7. Reflectance loss of prospective solar concentrator mirrors in erosive environments. The Crosbyton Solar Power Project

    SciTech Connect

    Bethea, R.M.; Barringer, M.T.; Chin, S.; Collier, E.G.; Cooper, A.M.; Reichert, J.D. Jr.; Williams, P.F.

    1986-01-01

    The problem addressed in this phase of the Crosbyton Solar Power Project was that of the effect of weathering of solar concentrator mirrors proposed for use in the fixed-mirror, distributed-focus (solar bowl) system with particular emphasis on erosion due to exposure during dust storms. The specific objectives of this research were to evaluate the mirrors with respect to initial reflectance, loss of reflectance due to dust storms and other outdoor exposure phenomena, and dimensional stability; and to develop a rapid technique for the simulation of dust storms so that a model for such reflectance loss as a function of exposure could be developed.

  8. Adapting the Water Erosion Prediction Project (WEPP) model for forest applications

    NASA Astrophysics Data System (ADS)

    Dun, Shuhui; Wu, Joan Q.; Elliot, William J.; Robichaud, Peter R.; Flanagan, Dennis C.; Frankenberger, James R.; Brown, Robert E.; Xu, Arthur C.

    2009-03-01

    SummaryThere has been an increasing public concern over forest stream pollution by excessive sedimentation due to natural or human disturbances. Adequate erosion simulation tools are needed for sound management of forest resources. The Water Erosion Prediction Project (WEPP) watershed model has proved useful in forest applications where Hortonian flow is the major form of runoff, such as modeling erosion from roads, harvested units, and burned areas by wildfire or prescribed fire. Nevertheless, when used for modeling water flow and sediment discharge from natural forest watersheds where subsurface flow is dominant, WEPP (v2004.7) underestimates these quantities, in particular, the water flow at the watershed outlet. The main goal of this study was to improve the WEPP v2004.7 so that it can be applied to adequately simulate forest watershed hydrology and erosion. The specific objectives were to modify WEPP v2004.7 algorithms and subroutines that improperly represent forest subsurface hydrologic processes; and, to assess the performance of the modified model by applying it to a research forest watershed in the Pacific Northwest, USA. Changes were made in WEPP v2004.7 to better model percolation of soil water and subsurface lateral flow. The modified model, WEPP v2008.9, was applied to the Hermada watershed located in the Boise National Forest, in southern Idaho, USA. The results from v2008.9 and v2004.7 as well as the field observations were compared. For the period of 1995-2000, average annual precipitation for the study area was 954 mm. Simulated annual watershed discharge was negligible using WEPP v2004.7, and was 262 mm using WEPP v2008.9, agreeable with field-observed 275 mm.

  9. Tectonic control on 10Be-derived erosion rates in the Garhwal Himalaya, India

    NASA Astrophysics Data System (ADS)

    Scherler, Dirk; Bookhagen, Bodo; Strecker, Manfred R.

    2014-02-01

    Erosion in the Himalaya is responsible for one of the greatest mass redistributions on Earth and has fueled models of feedback loops between climate and tectonics. Although the general trends of erosion across the Himalaya are reasonably well known, the relative importance of factors controlling erosion is less well constrained. Here we present 25 10Be-derived catchment-averaged erosion rates from the Yamuna catchment in the Garhwal Himalaya, northern India. Tributary erosion rates range between ~0.1 and 0.5 mm yr-1 in the Lesser Himalaya and ~1 and 2 mm yr-1 in the High Himalaya, despite uniform hillslope angles. The erosion-rate data correlate with catchment-averaged values of 5 km radius relief, channel steepness indices, and specific stream power but to varying degrees of nonlinearity. Similar nonlinear relationships and coefficients of determination suggest that topographic steepness is the major control on the spatial variability of erosion and that twofold to threefold differences in annual runoff are of minor importance in this area. Instead, the spatial distribution of erosion in the study area is consistent with a tectonic model in which the rock uplift pattern is largely controlled by the shortening rate and the geometry of the Main Himalayan Thrust fault (MHT). Our data support a shallow dip of the MHT underneath the Lesser Himalaya, followed by a midcrustal ramp underneath the High Himalaya, as indicated by geophysical data. Finally, analysis of sample results from larger main stem rivers indicates significant variability of 10Be-derived erosion rates, possibly related to nonproportional sediment supply from different tributaries and incomplete mixing in main stem channels.

  10. Wind tunnel experimental study on the effect of PAM on soil wind erosion control.

    PubMed

    He, Ji-Jun; Cai, Qiang-Guo; Tang, Ze-Jun

    2008-10-01

    In recent years, high-molecular-weight anionic polyacrylamide (PAM) have been widely tested on a variety of soils, primarily in water erosion control. However, little information is available regarding the effectiveness of PAM on preventing soil loss from wind erosion. The research adopted room wind tunnel experiment, two kinds of soils were used which were from the agro-pastoral area of Inner Mongolia, the northwest of China, the clay content of soils were 22.0 and 13.7%, respectively. For these tests, all the treatments were performed under the condition of wind velocity of 14 m s(-1) and a blown angle of 8.75%, according to the actual situation of experimented area. The study results indicated that using PAM on the soil surface could enhance the capability of avoiding the wind erosion, at the same time, the effect of controlling wind soil erosion with 4 g m(-2) PAM was better than 2 g m(-2) PAM's. Economically, the 2 g m(-2) PAM used in soil surface can control wind erosion effectively in this region. The prophase PAM accumulated in soil could not improve the capability of avoiding the wind erosion, owing to the degradation of PAM in the soil and the continual tillage year after year. The texture of soil is a main factor influencing the capability of soil avoiding wind erosion. Soil with higher clay content has the higher capability of preventing soil from wind erosion than one with the opposite one under the together action of PAM and water.

  11. Extreme soil erosion rates in citrus slope plantations and control strategies. A literature review

    NASA Astrophysics Data System (ADS)

    Cerdà, Artemi; Ángel González Peñaloza, Félix; Pereira, Paulo; Reyes Ruiz Gallardo, José; García Orenes, Fuensanta; Burguet, María

    2013-04-01

    irrigated land, and this contributes to increase the soil losses due to the sloping terrain. Although citrus is a world wide food, and occupy a large surface little is being researched on their impact on soil erosion, land degradation and strategies to control the soil, water and nutrient losses. This paper review the research developed until now and the results show that there is a poor background on this topic. It is necessary to develop research projects to improve the knowledge on the impact of citrus plantations on soil degradation and soil erosion. Another key information from the literature review done, is that most of the research was done in two regions of China and one of the Mediterranean. Definitively, a poor understanding of a huge environmental problem that need more scientific research. Acknowledgements The research projects GL2008-02879/BTE and LEDDRA 243857 supported this research. References Bombino, G., Denisi, P., Fortugno, D., Tamburino, V., Zema, D.A., Zimbone, S.M. 2010. Land spreading of solar-dried citrus peel to control runoff and soil erosion. WIT Transactions on Ecology and the Environment, 140, 145-154. Cerdà, A., Giménez Morera, A., Burguet, M., Arcenegui, V., González Peñaloza, F.A., García-Orenes, F., Pereira, P. 2012. The impact of the farming, abandonment and agricultural intensification on loss of water and soil. The example of the northern slopes of the Serra Grossa, Eastern Spain [El impacto del cultivo, el abandono y la intensificación de la agricultura en la pérdida de agua y suelo. el ejemplo de la vertiente norte de la serra grossa en el este peninsular] Cuadernos de Investigacion Geografica, 38 (1), 75-94. Cerdà, A., Jurgensen, M.F. 2008. The influence of ants on soil and water losses from an orange orchard in eastern Spain. Journal of Applied Entomology, 132 (4), 306-314. Cerdà, A., Jurgensen, M.F. 2011. Ant mounds as a source of sediment on citrus orchard plantations in eastern Spain. A three-scale rainfall simulation

  12. Large-scale performance and design for construction activity erosion control best management practices.

    PubMed

    Faucette, L B; Scholl, B; Beighley, R E; Governo, J

    2009-01-01

    The National Pollutant Discharge Elimination System (NPDES) Phase II requires construction activities to have erosion and sediment control best management practices (BMPs) designed and installed for site storm water management. Although BMPs are specified on storm water pollution prevention plans (SWPPPs) as part of the construction general permit (GP), there is little evidence in the research literature as to how BMPs perform or should be designed. The objectives of this study were to: (i) comparatively evaluate the performance of common construction activity erosion control BMPs under a standardized test method, (ii) evaluate the performance of compost erosion control blanket thickness, (iii) evaluate the performance of compost erosion control blankets (CECBs) on a variety of slope angles, and (iv) determine Universal Soil Loss Equation (USLE) cover management factors (C factors) for these BMPs to assist site designers and engineers. Twenty-three erosion control BMPs were evaluated using American Society of Testing and Materials (ASTM) D-6459, standard test method for determination of ECB performance in protecting hill slopes from rainfall induced erosion, on 4:1 (H:V), 3:1, and 2:1 slopes. Soil loss reduction for treatments exposed to 5 cm of rainfall on a 2:1 slope ranged from-7 to 99%. For rainfall exposure of 10 cm, treatment soil loss reduction ranged from 8 to 99%. The 2.5 and 5 cm CECBs significantly reduced erosion on slopes up to 2:1, while CECBs < 2.5 cm are not recommended on slopes >or= 4:1 when rainfall totals reach 5 cm. Based on the soil loss results, USLE C factors ranged from 0.01 to 0.9. These performance and design criteria should aid site planners and designers in decision-making processes.

  13. Climatic controls on steady state erosion using the relationship between channel steepness and cosmogenic 10Be-derived catchment averaged erosion rates

    NASA Astrophysics Data System (ADS)

    Rossi, M. W.; Whipple, K. X.; DiBiase, R. A.; Heimsath, A. M.

    2011-12-01

    To understand landscape response to climate change, baseline controls on erosion rates must be established for given climate conditions. Theory suggests a number of climate metrics should be important to erosion (i.e. precipitation, temperature, storminess, seasonality, snow fraction). Nevertheless, definitive field evidence quantifying how climate affects erosion rate has proven difficult to obtain. This is at least partly due to the difficulty of isolating climatic influences on erosion rates from topographic and rock strength influences. We circumvent this problem by evaluating how climate influences the relationship between erosion rate and topography in settings with similar rock types. At steady state, tectonic uplift dictates erosion rate, and climate and rock strength are manifest as changes in erosional efficiency - the topographic relief necessary to maintain the tectonically imposed erosion rate. In fluvial landscapes, bedrock rivers set the relevant scale of topographic relief, which can be described by the channel steepness index. A number of recent studies have shown that the relationship between channel steepness and millennial scale erosion rates is non-linear, implying that erosional efficiency increases with relief. Work in the San Gabriel Mountains suggests this relationship is due to erosion thresholds that limit incision of channels in low relief landscapes. By using a fluvial incision model that incorporates a range of daily discharge events coupled with an erosion threshold (Lague et al., 2005), the influence of flood frequency on the relationship between channel steepness and erosion rate can be explored. We apply this same modeling approach to five other landscapes that exhibit a range of channel steepness, have similar rock types (granitoids), but that are in dramatically different climate regimes ranging from desert to rainforest (annual rainfall, P, from 0.25 to 3 m/yr). Specifically, we present new cosmogenic 10Be erosion rate data from

  14. Using a paleo perspective to decipher climate controls on erosion and landscape evolution

    NASA Astrophysics Data System (ADS)

    Roering, J. J.; Marshall, J. A.; Granger, D. E.; Fox, M.; Gavin, D. G.; White, L. W.

    2015-12-01

    Today, topographic, erosion, and climate data are measured in abundance but the role of climate in modulating sediment production and landscape evolution remains difficult to characterize. Studies that quantify climate controls on denudation by analyzing multiple study areas with varying temperature and precipitation are hampered by site-to-site variations in topography, substrate, and vegetation, as well as uncertainty in the state of landscape adjustment. Alternatively, sedimentary records at a given location provide a means to track how climate variations influence sediment flux and weathering rates and mechanisms. Cosmogenic nuclide concentrations in well-dated sediment cores provide a means to quantify how erosion rates track climate, particularly orbital (or Milankovitch), fluctuations. Most cosmogenic analyses of erosion assume steady exhumation. By contrast, time-varying cosmogenic concentrations at a given location require a systematic inverse analysis of inheritance to decipher actual erosion rate changes that integrate in observed cosmogenic concentrations. Failure to consider transient erosion results in biased interpretations of paleo-erosion datasets. Here, we use a suite of inverse methods to constrain erosion rates through the last 50kya at our forested, steepland field site in western Oregon where Last Glacial Maximum (LGM) erosion rates are observed to be 2.5x faster than modern rates. Both paleoclimate simulations and paleovegetation data indicate colder and drier conditions during the LGM across our study domain, such that temperature, rather than precipitation, may be the dominant driver of geomorphic processes during glacial intervals in many mid-latitude regions. Other climate dependencies will apply elsewhere, but the coupling of process theory and climate reconstructions with well-characterized sedimentary records will help resolve the enigmatic role of climate fluctuations.

  15. Model based optimization of wind erosion control by tree shelterbelt for suitable land management

    NASA Astrophysics Data System (ADS)

    Bartus, M.; Farsang, A.; Szatmári, J.; Barta, K.

    2012-04-01

    The degradation of soil by wind erosion causes huge problem in many parts of the world. The wind erodes the upper, nutrition rich part of the soil, therefore erosion causes soil productivity loss. The length of tree shelterbelts was significantly reduced by the collectivisation (1960-1989) and the wind erosion affected areas expanded in Hungary. The tree shelterbelt is more than just a tool of wind erosion control; by good planning it can increase the yield. The tree shelterbelt reduces the wind speed and changes the microclimate providing better condition to plant growth. The aim of our work is to estimate wind erosion risk and to find the way to reduce it by tree shelterbelts. A GIS based model was created to calculate the risk and the optimal windbreak position was defined to reduce the wind erosion risk to the minimum. The model is based on the DIN 19706 (Ermitlung der Erosiongefährdung von Böden durch Wind, Estimation of Wind Erosion Risk) German standard. The model uses five input data: structure and carbon content of soil, average yearly wind speed at 10 meters height, the cultivated plants and the height and position of windbreak. The study field (16km2) was chosen near Szeged (SE Hungary). In our investigation, the cultivated plant species and the position and height of windbreaks were modified. Different scenarios were made using the data of the land management in the last few years. The best case scenario (zero wind erosion) and the worst case scenario (with no tree shelter belt and the worst land use) were made to find the optimal windbreak position. Finally, the research proved that the tree shelterbelts can provide proper protection against wind erosion, but for optimal land management the cultivated plant types should also controlled. As a result of the research, a land management plan was defined to reduce the wind erosion risk on the study field, which contains the positions of new tree shelterbelts planting and the optimal cultivation.

  16. Erosion risk assessment of controlled burning of grasses established on steep slopes

    NASA Astrophysics Data System (ADS)

    Gyasi-Agyei, Yeboah

    2006-02-01

    It is a standard practice to establish grasses on steep slopes (batters) of embankments and cuttings to minimise erosion problems. However, the increase in grass density (high biomass) on the steep slopes poses a greater risk of fire. Controlled burning is a common fuel hazard reduction program employed to minimise the fire risks. The increased risk of erosion on the steep slopes after controlled burning has received little attention if any. This paper assesses the erosion risks associated with controlled burning of grasses established on steep slopes. Grasses, with and without the aid of waste ballast rock mulch, were established on 10 m wide railway embankment batter experiment plots. Two-and-a-half years after the grass establishment, selected plots were controlled burned. Runoff and soil loss from the experimental plots were monitored throughout the 3½-year period of the experiment. After one year the grass cover on the burned plots has hardly exceeded 60%, far below the average pre-burn levels of about 80%. All treatments achieved an incredible soil loss reduction of over 95% (compared with the bare scenario) without controlled burning at the end of the 3½-year period. This percentage value was decreased numerically by 14 where controlled burning was implemented. Compared with the 100% grass cover treatment, runoff rates tripled while erosion rates increased by nine-fold for the waste ballast treatment, and 17-fold for the non-waste ballast treatment, during the first year following controlled burning.

  17. Estimating soil erosion risk and evaluating erosion control measures for soil conservation planning at Koga watershed in the highlands of Ethiopia

    NASA Astrophysics Data System (ADS)

    Molla, Tegegne; Sisheber, Biniam

    2017-01-01

    Soil erosion is one of the major factors affecting sustainability of agricultural production in Ethiopia. The objective of this paper is to estimate soil erosion using the universal soil loss equation (RUSLE) model and to evaluate soil conservation practices in a data-scarce watershed region. For this purpose, soil data, rainfall, erosion control practices, satellite images and topographic maps were collected to determine the RUSLE factors. In addition, measurements of randomly selected soil and water conservation structures were done at three sub-watersheds (Asanat, Debreyakob and Rim). This study was conducted in Koga watershed at upper part of the Blue Nile basin which is affected by high soil erosion rates. The area is characterized by undulating topography caused by intensive agricultural practices with poor soil conservation practices. The soil loss rates were determined and conservation strategies have been evaluated under different slope classes and land uses. The results showed that the watershed is affected by high soil erosion rates (on average 42 t ha-1 yr-1), greater than the maximum tolerable soil loss (18 t ha-1 yr-1). The highest soil loss (456 t ha-1 yr-1) estimated from the upper watershed occurred on cultivated lands of steep slopes. As a result, soil erosion is mainly aggravated by land-use conflicts and topographic factors and the rugged topographic land forms of the area. The study also demonstrated that the contribution of existing soil conservation structures to erosion control is very small due to incorrect design and poor management. About 35 % out of the existing structures can reduce soil loss significantly since they were constructed correctly. Most of the existing structures were demolished due to the sediment overload, vulnerability to livestock damage and intense rainfall. Therefore, appropriate and standardized soil and water conservation measures for different erosion-prone land uses and land forms need to be implemented in Koga

  18. Er:YAG laser irradiation to control the progression of enamel erosion: an in situ study.

    PubMed

    Scatolin, R S; Colucci, V; Lepri, T P; Alexandria, A K; Maia, L C; Galo, R; Borsatto, M C; Corona, S A M

    2015-07-01

    This in situ study evaluated the effect of Er:YAG laser irradiation in controlling the progression of enamel erosion-like lesions. Fifty-six enamel slabs (330 KHN ± 10 %) with one fourth of the surface covered with resin composite (control area) were submitted to initial erosion-like lesion formation with citric acid. The slabs were divided into two groups: irradiated with Er:YAG laser and non-irradiated. Fourteen volunteers used an intraoral palatal appliance containing two slabs, in two phases of 5 days each. During the intraoral phase, in a crossed-over design, half of the volunteers immersed the appliance in citric acid while the other half used deionized water, both for 5 min, three times per day. Enamel wear was determined by an optical 3D profilometer. ANOVA revealed that when deionized water was used as immersion solution during the intraoral phase, lower values of wear were showed when compared with the groups that were eroded with citric acid, whether irradiated or non-irradiated with Er:YAG laser. When erosion with citric acid was performed, Er:YAG laser was not able to reduce enamel wear. Small changes on enamel surface were observed when it was irradiated with Er:YAG laser. It may be concluded that Er:YAG laser irradiation did not reduce the progression of erosive lesions on enamel submitted to in situ erosion with citric acid.

  19. Tempo-spatial downscaling of multiple GCMs projections for soil erosion risk analysis at El Reno, Oklahoma, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proper spatial and temporal treatments of climate change scenarios projected by General Circulation Models (GCMs) are critical to accurate assessment of climatic impacts on natural resources and ecosystems. For accurate prediction of soil erosion risk at a particular farm or field under climate cha...

  20. Effective and low cost erosion control of inactive coal storage piles

    SciTech Connect

    Simmons, D.E.; Degenhardt, G.M.; Jones, R.W.

    1983-11-01

    Erosion of coal stockpiles by wind and rain cost utilities thousands of dollars each year in lost fuel, coal pile maintenance and environmental equipment. The main problem at Nelson Unit 6 was loss due to frequent and heavy rains. Average yearly rainfall in that part of Louisiana is 56''. There is a definite ''rainy season'' in the winter months and the long summer brings heavy tropical type downpours. This paper outlines efforts to control erosion by conventional methods, chemical treatment and finally the application of aereated flyash to the coal pile slopes.

  1. Processes and controls of ditch erosion and suspended sediment transport in drained peatland forests

    NASA Astrophysics Data System (ADS)

    Tuukkanen, Tapio; Stenberg, Leena; Marttila, Hannu; Finér, Leena; Piirainen, Sirpa; Koivusalo, Harri; Kløve, Bjørn

    2016-04-01

    Drainage and periodic ditch cleaning are needed in peatland forests to allow adequate tree growth. The downside is that these practices usually increase erosion and transport of organic and inorganic matter to downstream waterbodies. In this study, our aim was to assess the role of hydrological factors and ditch-level bed and bank erosion processes in controlling suspended sediment (SS) transport in peatland forests after ditch cleaning. To do this, a 113 ha catchment and a nested sub-catchment (5.2 ha) in eastern Finland were instrumented for continuous hydrological and SS concentration (turbidity) measurements and for the detection of ditch bed and bank erosion with erosion pins. The impacts of ditch cleaning on instantaneous unit hydrographs were also assessed against two reference catchments. The results suggested that, in small intensively drained catchments, SS transport is likely to be limited by the availability of easily erodible sediment in the ditch network, and that ditch cleaning operations as well as preparatory bank erosion processes such as peat desiccation and frost action can be important in producing erodible sediment for transport. Detachment of soil particle from ditch banks by raindrop impact can also be an important factor explaining variations in SS concentrations in small catchments. In larger drainage areas, peak runoff characteristics may play a more dominant role in SS transport. The results give new insights into the dynamics of sediment transport in drained peatland catchments, which can be useful, for example, for planning and implementation of water conservation measures.

  2. Evaluating a Wood-strand Material for Wind Erosion Control and Air Quality Protection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fugitive dust from eroding land poses both environmental quality and human health problems in the western United States. Since the advent of the Clean Air Act in 1990, regulations have been imposed on particulate matter in the atmosphere. Agricultural straw has been widely used for erosion control...

  3. Using computer models to design gully erosion control structures for humid northern Ethiopia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Classic gully erosion control measures such as check dams have been unsuccessful in halting gully formation and growth in the humid northern Ethiopian highlands. Gullies are typically formed in vertisols and flow often bypasses the check dams as elevated groundwater tables make gully banks unstable....

  4. 77 FR 47063 - Notice of Availability of Draft Revisions; Upland Erosion Control, Revegetation, and Maintenance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-07

    ... Certificates: Construction, Acquisition, and Abandonment'' (OMB Control No. 1902-0060), which is used by the... reuse of construction materials is provided in revised Plan sections II.B.17. and III.E. Identification... Energy Regulatory Commission Notice of Availability of Draft Revisions; Upland Erosion...

  5. An Economic Analysis of USDA Erosion Control Programs: A New Perspective. Agricultural Economic Report No. 560.

    ERIC Educational Resources Information Center

    Strohbehn, Roger, Ed.

    A study analyzed the total (public and private) economic costs and benefits of three U.S. Department of Agriculture erosion control programs. These were the Conservation Technical Assistance Program, Great Plains Conservation Program, and Agricultural Conservation Program. Significant efforts at funding for current programs were directed to…

  6. Comprehensive Erosion and Sediment Control Training Program for Job Superintendents and Inspectors.

    ERIC Educational Resources Information Center

    Porter, Harry L., Jr.

    One of two training program texts built around the Virginia Erosion and Sediment Control Law and Program, this guide presents a program designed to meet the needs of job superintendents and inspectors. (The other guide, containing a program for engineers, architects, and planners, was designed to train professional people who need engineering and…

  7. Comprehensive Erosion and Sediment Control Training Program for Engineers, Architects and Planners.

    ERIC Educational Resources Information Center

    Porter, Harry L., Jr.

    This program training text was designed to provide uniform instruction to the engineer, architect, planner, and others who will be helping to implement an erosion and sediment control program. Although tailored for use in Virginia, the basic principles covered are universal, and the material is adaptable to meet the needs in any State. The 11…

  8. Erosion and Soil Contamination Control Using Coconut Flakes And Plantation Of Centella Asiatica And Chrysopogon Zizanioides

    NASA Astrophysics Data System (ADS)

    Roslan, Rasyikin; Che Omar, Rohayu; Nor Zuliana Baharuddin, Intan; Zulkarnain, M. S.; Hanafiah, M. I. M.

    2016-11-01

    Land degradation in Malaysia due to water erosion and water logging cause of loss of organic matter, biodiversity and slope instability but also land are contaminated with heavy metals. Various alternative such as physical remediation are use but it not showing the sustainability in term of environmental sustainable. Due to that, erosion and soil contamination control using coconut flakes and plantation of Centella asiatica and Chrysopogon zizanioides are use as alternative approach for aid of sophisticated green technology known as phytoremediation and mycoremediation. Soil from cabonaceous phyllite located near to Equine Park, Sri Kembangan are use for monitoring the effect of phytoremediation and mycoremediation in reducing soil contamination and biotechnology for erosion control. Five laboratory scale prototypes were designed to monitor the effect of different proportion of coconut flakes i.e. 10%, 25%, 50% & 100% and plantation of Centella asiatica and Chrysopogon zizanioides to reduce the top soil from eroding and reduce the soil contamination. Prototype have been observe started from first week and ends after 12 weeks. Centella asiatica planted on 10% coconut flakes with 90% soil and Chrysopogon zizanioides planted on 25% coconut flakes with 75% soil are selected proportion to be used as phytoremediation and mycoremediation in reducing soil contamination and biotechnology for erosion control.

  9. Soil erosion and sediment control laws. A review of state laws and their natural resource data requirements

    NASA Technical Reports Server (NTRS)

    Klein, S. B.

    1980-01-01

    Twenty states, the District of Columbia, and the Virgin Islands enacted erosion and sediment control legislation during the past decade to provide for the implementation or the strengthening of statewide erosion and sediment control plans for rural and/or urban lands. That legislation and the state programs developed to implement these laws are quoted and reviewed. The natural resource data requirements of each program are also extracted. The legislation includes amendments to conservation district laws, water quality laws, and erosion and sediment control laws. Laws which provides for legislative review of administrative regulations and LANDSAT applications and/or information systems that were involved in implementing or gathering data for a specific soil erosion and sediment control program are summarized as well as principal concerns affecting erosion and sediment control laws.

  10. Chosing erosion control nets. Can't you decide? Ask the lab.

    NASA Astrophysics Data System (ADS)

    Simkova, Jana; Jacka, Lukas

    2015-04-01

    Geotextiles (GTXs) have been used to protect steep slopes against soil erosion for about 60 years and many products have become available. The choice of individual product is always based on its ratio of cost versus effectiveness. Generally applicable recommendations for specific site conditions are missing and testing the effectiveness of GTXs in the field is time consuming and costly. Due to various site conditions, results of numerous case-studies cannot be generalized. One of the major and site-specific factors affecting the erosion process, and hence the effectiveness of GTXs, is the soil. This study aimed to determine the rate of influence of three natural erosion control nets on the volume and velocity of surface runoff caused by rainfall. The nets were installed on slope under laboratory conditions and then exposed to simulated rainfall. An impermeable plastic film was used as a substrate instead of soil to simulate non-infiltrating conditions. A comparison of the influence of tested GTX samples on surface runoff may indicate to their erosion control effect. Thus, the results could help with choosing a particular product. Under real conditions, the effect of erosion control nets would be increased by the infiltration capacity of the soil, equally for all samples. Therefore, the order of effectiveness of the samples should stay unchanged. To validate this theory, a field experiment was carried out where soil loss was recorded along with runoff characteristics. The data trends of discharge culmination under natural conditions were similar to trends under laboratory conditions and corresponded to soil loss records.

  11. Project resources planning and control

    NASA Technical Reports Server (NTRS)

    Sibbers, C. W.

    1984-01-01

    This report contains instructional guidelines for the resources planning and control of research and development (R&D) projects managed by NASA's Langley Research Center (LaRC). Although written to serve primarily as a practical guide and reference for those LaRC personnel who perform resources planning, analysis, control, and reporting functions, it should also be meaningful to other NASA personnel who are directly or indirectly involved in or affected by these functions, especially project technical managers whose responsibilities include resources management. Certain sections should help Contractor personnel to better understand what resources information must usually be submitted on LaRC projects and what use is made of such information. The Project Manager of a large R&D project typicaly receives support from an Analyst in the area of resources management. The Analyst provides assistance in four functional areas: Planning, Analysis/Control, Administration, and Reporting. Each of these functions are discussed in detail. Examples of techniques used effectively on LaRC projects have been included where applicable. A considerable amount of information has been included on the use of Performance Measurement (Earned Value) Systems for contract cost control and reporting as little information is currently available on this subject in NASA publications.

  12. Offshore sand resources for coastal erosion control in Louisiana

    SciTech Connect

    Ramsey, K.E.; Penland, S.; McBride, R.A. ); Suter, J.R. ); Williams, J. )

    1990-09-01

    An inventory of existing geophysical data supplemented by more than 15,000 km of high-resolution seismic profiles and 400 vibracores collected cooperatively by the Louisiana Geological Survey and US Geological Survey since 1981 indicates that a wide range of aggregate minerals occurs on the continental shelf in a variety of depositional settings. The distribution of these deposits is controlled by the geometry of the preexisting fluvial and deltaic channel systems and the stratigraphic signature of the Holocene Transgression across these features. The geology of coastal and offshore Louisiana is tied to the depositional history of the Mississippi River. Offshore of the delta plain, five types of aggregate sources can be identified: inner shelf shoals, submerged barrier islands, tidal inlets, distributary channels, and barrier platforms. This paper describes the geology of offshore Louisiana, the available geophysical data sets, and the distribution of aggregate mineral resources. On the continental shelf of the Mississippi River delta plain, two extensive seismic survey grids have been developed by the Louisiana Geological Survey and US Geological Survey. The most prospective resources found are the huge sand bodies of Ship Shoal and associated distributaries, Cat Island Pass tidal channels and associated tidal deltas, and Barataria Pass/Grand Terre tidal channels and associated tidal deltas. East of the mouth of the Mississippi River are the Chandeleur Islands, where LGS identified seven major sand resource targets, truncated barrier-spit and tidal inlet deposits, submerged beach ridges, and distributaries associated with abandoned St. Bernard delta complexes. Abundant sand resources can be found in offshore Louisiana. Many of the sand bodies contain heavy minerals, but their concentration and distribution is unknown. Other potential sand resources not yet adequately explored include Sabine Bank, the Outer Shoal, and the St. Bernard shoal.

  13. Assessment of the role of bottomland hardwoods in sediment and erosion control

    USGS Publications Warehouse

    Molinas, A.; Auble, Gregor T.; Segelquist, C.A.; Ischinger, Lee S.

    1988-01-01

    Drainage and clearing of bottomland hardwoods have long been recognized by the U.S. Environmental Protection Agency (EPA) and the U.S. Fish and Wildlife Service (Service) as important impacts of Federal water projects in the lower Mississippi River Valley. More recently, the water quality impacts of such projects (e.g., increases in sediments, nutrients, and pesticides) have also become of concern. In 1984, in an effort to better define problems concerning wetland losses and water degradation, EPA initiated a cooperative project with the Western Energy and Land Use Team (now the National Ecology Research Center) of the Service. Three phases of the project were identified: 1. To collect existing literature and data; 2. To select, develop, and test the utility of methods to quantify the relationships between land use, cover types, soils, hydrology, and water quality (as represented by sediment); and 3. To apply selected methodologies to several sites within the Yazoo Basin of Mississippi to determine the, potential effectiveness of various management alternatives to reduce sediment yield, increase sediment deposition, and improve water quality. Methods development focused on linking a simulation of water and sediment movement to a computerized geographic information system. We had several objectives for the resulting model. We desired that it should: 1. Estimate the importance of bottomland and hardwoods as a cover type that performs the functions of erosion and sediment control, 2. Simulate effects of proportions of ' various cover types and their specific spatial configurations, 3. Be applicable to moderately large spatial areas with minimal site-specific calibration, 4. Simulate spatial patterns of sediment loss-gain over time, and 5. Represent both sediment detachment and transport. While it was recognized that impacts and management alternatives could be sorted roughly into landscape measures and channel measures, the decision was made to focus study efforts

  14. Project test plan for runoff and erosion on fine-soil barrier surfaces and rock-covered side slopes

    SciTech Connect

    Walters, W.H.; Hoover, K.A.; Cadwell, L.L.

    1990-06-01

    Pacific Northwest Laboratory (PNL) and Westinghouse Hanford Company are working together to develop protective barriers to isolate near-surface radioactive waste. The purpose of the barriers is to protect defense wastes at the US Department of Energy's (DOE) Hanford Site from infiltration of precipitation, biointrusion, and surficial erosion for up to 10,000 years without the need for long-term monitoring, maintenance, or institutional control. The barriers will be constructed of layered earth and rock material designed to direct surface and groundwater pathways away from the buried waste. To address soil erosion as it applies to barrier design and long-term stability, a task designed to study this problem has been included in the Protective Barriers Program at PNL. The barrier soil-erosion task will investigate the ability of the soil cover and side slopes to resist the erosional and destabilizing processes from externally applied water. The study will include identification and field testing of the dominant processes contributing to erosion and barrier failure. The effects of rock mulches, vegetation cover on the top fine-grained soil surface, as well as the stability of rock armoring on the side slopes, will be evaluated. Some of the testing will include the effects of animal intrusion on barrier erosion, and these will be coordinated with other animal intrusion studies. 6 refs., 4 figs., 1 tab.

  15. Ventura County, California. Survey Report for Beach Erosion Control. Main Report.

    DTIC Science & Technology

    1980-05-01

    AD-Ai7i 548 VENTURA COUNTY CALIFORNIA SURVEY REPORT FOR BEACH 1/i EROSION CONTROL MAIN REPORT(U) ARMY ENGINEER DISTRICT LOS ANGELES CA MAY 88...areas that furnish sediments to the beaches consist of the Ventura River Basin, Santa Clara River Basin, and Calleguas-Simi Creek Basin. Bedrock in...considerable extent in Ojai Valley, the foothills south of Ventura , the Saugus and Santa Paula Creek regions, the headwaters of Piru Creek and the Santa

  16. Evaluation of different techniques for erosion control on different roadcuts in its first year of implantation

    NASA Astrophysics Data System (ADS)

    Gomez, Jose Alfonso; Rodríguez, Abraham; Viedma, Antonio; Contreras, Valentin; Vanwalleghem, Tom; Taguas, Encarnación V.; Giráldez, Juan Vicente

    2014-05-01

    Linear infrastructures, such as highways and railways, present a large environmental impact. Among this impact is the effect on landscape and the modification of the hydrological conditions of the area and an increase in erosive processes (Martin et al., 2011). The increase of erosive processes is specially significant in roadbanks, resulting in high maintenance costs as well as security risks for the use of the infrastructure if it is not properly controlled. Among roadbanks, roadcuts are specially challenging areas for erosion control and ecological restoration, due to their usually steep slope gradient and poor conditions for establishment of vegetation. There are several studies in Mediterranean conditions indicating how the combination of semiarid conditions with, sporadic, intense rainfall events makes a successful vegetation development and erosion control in motorway roadbanks extremely difficult (e.g. Andrés and Jorbat, 2000; Bochet and García-Fayos, 2004). This communication presents the results of the first year evaluation (hydrological year 2012-2013) of five different erosion control strategies on six different locations under different materials on roadcuts of motorways or railways in Andalusia during 2012-2013 using natural rainfall and simulated rainfall. The six sites were located on roadcuts between 10 and 20 m long on slope steepness ranging from 40 to 90%, in motorways and railways spread over different materials in Andalusia. Site 1, Huelva was located on consolidated sand material, sites 2, Osuna I, site 3, Osuna II and site 4, Mancha Real, on marls. Sites 5, Guadix, and 6, Fiñana, were located on phyllites, in comparison a harder material. At each site 12 plots (10 m long and 2 m wide) were installed using metal sheets buried 10 cm within the soil with their longest side in the direction of the roadcut maximum slope. Six different treatments were evaluated at each site, two replications each. These treatments were: 1- A control with bare

  17. [Mechanisms of grass in slope erosion control in Loess sandy soil region of Northwest China].

    PubMed

    Zhao, Chun-Hong; Gao, Jian-En; Xu, Zhen

    2013-01-01

    By adopting the method of simulated precipitation and from the viewpoint of slope hydrodynamics, in combining with the analysis of soil resistance to erosion, a quantitative study was made on the mechanisms of grass in controlling the slope erosion in the cross area of wind-water erosion in Loess Plateau of Northwest China under different combinations of rainfall intensity and slope gradient, aimed to provide basis to reveal the mechanisms of vegetation in controlling soil erosion and to select appropriate vegetation for the soil and water conservation in Loess Plateau. The grass Astragalus adsurgens with the coverage about 40% could effectively control the slope erosion. This grass had an efficiency of more than 70% in reducing sediment, and the grass root had a greater effect than grass canopy. On bare slope and on the slopes with the grass plant or only the grass root playing effect, there existed a functional relation between the flow velocity on the slopes and the rainfall intensity and slope gradient (V = DJ(0.33 i 0.5), where V is flow velocity, D is the comprehensive coefficient which varies with different underlying surfaces, i is rainfall intensity, and J is slope gradient). Both the grass root and the grass canopy could markedly decrease the flow velocity on the slopes, and increase the slope resistance, but the effect of grass root in decreasing flow velocity was greater while the effect in increasing resistance was smaller than that of grass canopy. The effect of grass root in increasing slope resistance was mainly achieved by increasing the sediment grain resistance, while the effect of canopy was mainly achieved by increasing the slope form resistance and wave resistance. The evaluation of the soil resistance to erosion by using a conceptual model of sediment generation by overland flow indicated that the critical shear stress value of bare slope and of the slopes with the grass plant or only the grass root playing effect was 0.533, 1.672 and 0

  18. Managing the Arroyo Seco for Flood Prevention, Erosion Control, Waterway and Habitat Restoration

    SciTech Connect

    Sanchez, L; Wang, C; Laurant, J

    2003-02-06

    One of the most important tasks for a site facility manager is to ensure that appropriate channel erosion controls are applied to on-site drainage channels. These erosion controls must minimize risks to the public and structures. Water and sediment loads commonly originate from off-site sources and many of the traditional reactionary measures (installing rip-rap or some other form of bed or bank armor) simply transfer or delay the problem. State and federal agency requirements further complicate the management solution. One case in point is the Arroyo Seco, an intermittent stream that runs along the southwest corner of the Lawrence Livermore National Laboratory (LLNL) in Livermore, California. In 2001, LLNL contracted Questa Engineering Corporation to conduct hydraulic, geomorphic, and biological investigations and to prepare an alternatives and constraints analysis. From these investigations, LLNL has selected a water management plan that encompasses overall flood prevention, erosion control, and waterway and habitat restoration and enhancement elements. The most unique aspect of the Arroyo Seco management plan is its use of non-traditional and biotechnical techniques.

  19. Microphonics control for Project X

    SciTech Connect

    Schappert, W.; Barbanotti, S.; Branlard, J.; Cancelo, G.; Carcagno, R.; Chase, B.; Champion, M.; Gonin, I.; Klebaner, A.; Orris, D.; Pischalnikov, Y.; /Fermilab

    2011-03-01

    The proposed multi-MW Project X facility at Fermilab will employ cavities with bandwidths as narrow as 20 Hz. This combination of high RF power with narrow bandwidths combined requires careful attention to detuning control if these cavities are to be operated successfully. Detuning control for Projects X will require a coordinated effort between the groups responsible for various machine subsystems. Considerable progress in this area has been made over the past year. Detuning levels in the Project X cavities, specifically the Low and High {beta} 650 MHz elliptical types, can have a significant impact on the overall cost of the project. The narrow bandwidths, and the high RF Power requirements, and the large number of these cavities mean that careful attention to detuning control will be required if these cavities are to operate successfully. Limiting cavity detuning in Project X will require a coordinated effort between the groups responsible for various subsystems of the planned machine. Considerable progress towards this goal has been made by each of these groups over the past year.

  20. Meta-analysis of the effects of plant roots in controlling concentrated flow erosion rates

    NASA Astrophysics Data System (ADS)

    Vannoppen, Wouter; Poesen, Jean; Vanmaercke, Matthias; De Baets, Sarah

    2015-04-01

    Vegetation is often used in ecological restoration programs to control various soil erosion processes. During the last two decades several studies reported on the effects of plant roots in controlling concentrated flow erosion rates. However a global analysis of the now available data on root effects is still lacking. Yet, a meta-data analysis will contribute to a better understanding of the soil-root interactions as our capability to assess the effectiveness of roots in reducing soil erosion rates due to concentrated flow in different environments remains difficult. The objectives of this study are therefore i) to provide a state of the art on studies quantifying the effectiveness of roots in reducing soil erosion rates due to concentrated flow; and ii) to explore the overall trends in erosion reduction as a function of the root (length) density, root system architecture and soil texture, based on a global analysis of published research data. We therefore compiled a dataset of measured relative soil detachment rates (RSD) for the root density (RD; 822 observations) as well as the root length density (RLD; 274 observations). Non-linear regression analyses showed that decreases in RSD as a function of RD and RLD could be best described with the Hill curve model. However, a large proportion of the variability in RSD could not be attributed to RD or RLD, resulting in a relatively low predictive accuracy of the Hill curve model with model efficiencies of 0.11 and 0.17 for RD and RLD respectively. Considering root architecture and soil texture yielded a better predictive model especially for RLD with ME of 0.37 for fibrous roots in a non-sandy soil. The unexplained variance is to a large extent attributable to measuring errors and differences in experimental set ups that could not be explicitly accounted for (e.g. tested plant species, soil and flow characteristics). However, using a Monte Carlo simulation approach, we were able to establish relationships that allow

  1. Controls on Quaternary Sediment Erosion and Provenance in the Himalayan Rain Shadow, Zanskar River, Northwest India

    NASA Astrophysics Data System (ADS)

    Jonell, T. N.; Clift, P. D.; Carter, A.

    2015-12-01

    The Asian Summer Monsoon exerts strong control over erosion in the frontal Himalaya and possibly farther onto the periphery of the Tibetan Plateau in the Himalayan rain shadow. This study evaluates the Zanskar River, a large rain shadow tributary to the Indus River system, to establish how monsoonal precipitation controls erosion patterns, sediment yield, and sediment composition in the Himalayan rain shadow. Bulk sediment petrography and U-Pb detrital zircon ages demonstrate that Zanskar River sands are overwhelmingly dominated by 600-850 Ma zircon, which is consistent with material eroding from Greater Himalayan lithologies. In particular, modern sediment production appears to be heavily concentrated in the wettest and most glaciated subcatchment. River terrace sands indicate that no significant change in the area of sediment production and basin-wide provenance signal has occurred since ~11.5 ka, despite changes in monsoon strength. Variability in subcatchment provenance signals, however, do shift locally with enhanced precipitation around the time of the Monsoon Maximum (10-8 ka). Detrital apatite fission track ages suggest rates of erosion typical for the northwest Indian Himalaya for the last 6.4 M.y. in Zanskar, in spite of the changing monsoonal climate. Together these data indicate most sediment in the Zanskar River is freshly-eroded and transmitted immediately downstream into the Indus River with only modest buffering in terraces.

  2. Performance and efficiency of geotextile-supported erosion control measures during simulated rainfall events

    NASA Astrophysics Data System (ADS)

    Obriejetan, Michael; Rauch, Hans Peter; Florineth, Florin

    2013-04-01

    Erosion control systems consisting of technical and biological components are widely accepted and proven to work well if installed properly with regard to site-specific parameters. A wide range of implementation measures for this specific protection purpose is existent and new, in particular technical solutions are constantly introduced into the market. Nevertheless, especially vegetation aspects of erosion control measures are frequently disregarded and should be considered enhanced against the backdrop of the development and realization of adaptation strategies in an altering environment due to climate change associated effects. Technical auxiliaries such as geotextiles typically used for slope protection (nettings, blankets, turf reinforcement mats etc.) address specific features and due to structural and material diversity, differing effects on sediment yield, surface runoff and vegetational development seem evident. Nevertheless there is a knowledge gap concerning the mutual interaction processes between technical and biological components respectively specific comparable data on erosion-reducing effects of technical-biological erosion protection systems are insufficient. In this context, an experimental arrangement was set up to study the correlated influences of geotextiles and vegetation and determine its (combined) effects on surface runoff and soil loss during simulated heavy rainfall events. Sowing vessels serve as testing facilities which are filled with top soil under application of various organic and synthetic geotextiles and by using a reliable drought resistant seed mixture. Regular vegetational monitoring as well as two rainfall simulation runs with four repetitions of each variant were conducted. Therefore a portable rainfall simulator with standardized rainfall intensity of 240 mm h-1 and three minute rainfall duration was used to stress these systems on different stages of plant development at an inclination of 30 degrees. First results show

  3. Erosion Coatings for High-Temperature Polymer Composites: A Collaborative Project With Allison Advanced Development Company

    NASA Technical Reports Server (NTRS)

    Sutter, James K.

    2000-01-01

    The advantages of replacing metals in aircraft turbine engines with high-temperature polymer matrix composites (PMC's) include weight savings accompanied by strength improvements, reduced part count, and lower manufacturing costs. Successfully integrating high-temperature PMC's into turbine engines requires several long-term characteristics. Resistance to surface erosion is one rarely reported property of PMC's in engine applications because PMC's are generally softer than metals and their erosion resistance suffers. Airflow rates in stationary turbine engine components typically exceed 2.3 kg/sec at elevated temperatures and pressures. In engine applications, as shown in the following photos, the survivability of PMC components is clearly a concern, especially when engine and component life-cycle requirements become longer. Although very few publications regarding the performance of erosion coatings on PMC's are available particularly in high-temperature applications the use of erosion-resistant coatings to significantly reduce wear on metallic substrates is well documented. In this study initiated by the NASA Glenn Research Center at Lewis Field, a low-cost (less than $140/kg) graphite-fiber-reinforced T650 35/PMR 15 sheet-molding compound was investigated with various coatings. This sheet-molding compound has been compression molded into many structurally complicated components, such as shrouds for gas turbine inlet housings and gearboxes. Erosion coatings developed for PMC s in this study consisted of a two-layered system: a bondcoat sprayed onto a cleaned PMC surface, followed by an erosion-resistant, hard topcoat sprayed onto the bondcoat as shown in following photomicrograph. Six erosion coating systems were evaluated for their ability to withstand harsh thermal cycles, erosion resistance (ASTM G76 83 "Standard Practice for Conducting Erosion Tests by Solid Particle Impingement Using Gas Jets") using Al2O3, and adhesion to the graphite fiber polyimide

  4. Direct and indirect impacts of climate change on soil erosion and land degradation in Mediterranean watersheds: a presentation of the ERLAND project

    NASA Astrophysics Data System (ADS)

    Nunes, João. Pedro; Corte-Real, João.; Keizer, Jan Jacob; Abrantes, Nelson; César Lima, Júlio; Roebeling, Peter; Sampaio, Elsa; Santos, João.; Eufémia Varela, Maria

    2010-05-01

    This presentation will describe the recently-approved ERLAND project (2010-2013), whose main aim is to estimate the impacts of climate change on soil erosion in representative Portuguese agroforestry watersheds, due to changes in rainfall, runoff generation and vegetation cover. Soil erosion is a critical driver for desertification in Mediterranean regions, degrading the soil's capacity to sustain vegetation under marginal climatic conditions. An increase in climatic aridity, caused by global climate change, could lead to increases or decreases in erosion, depending on the interaction between lower rainfall and lower vegetation biomass productivity The main objective of ERLAND is to characterize the most important impacts climate change could cause on different erosive processes within Mediterranean catchments, and help define the costs and benefits of different adaptation options. The project explicitly addresses important limitations of similar past studies, such as: (i) lack of appropriate downscaling of climate change scenarios; (ii) focus on hillslope or, in rare instances, channel processes, ignoring gully erosion; or (iii) lack of sufficient erosion data for the proper evaluation of the erosion models used in these assessments. The main analysis tool will be a new vegetation, runoff and erosion model, built by joining together existing and widely tested concepts to simulate vegetation, hydrology and erosion. It will aim at the continuous simulation of sediment detachment and transport within catchments, using a detailed simulation of spatial patterns while simplifying the simulation of temporal patterns, allowing for a multi-year application. The project will focus on two catchments, corresponding to typical combinations of climate and land cover/use under humid and dry climate conditions: in northern Portugal, eucalypt/pine commercial forestry combined with annual cultures or vineyards; in southern Portugal, extensive cork oak forestry (montado) associated

  5. Materials for Advanced Turbine Engines (MATE). Project 4: Erosion resistant compressor airfoil coating

    NASA Technical Reports Server (NTRS)

    Rashid, J. M.; Freling, M.; Friedrich, L. A.

    1987-01-01

    The ability of coatings to provide at least a 2X improvement in particulate erosion resistance for steel, nickel and titanium compressor airfoils was identified and demonstrated. Coating materials evaluated included plasma sprayed cobalt tungsten carbide, nickel carbide and diffusion applied chromium plus boron. Several processing parameters for plasma spray processing and diffusion coating were evaluated to identify coating systems having the most potential for providing airfoil erosion resistance. Based on laboratory results and analytical evaluations, selected coating systems were applied to gas turbine blades and evaluated for surface finish, burner rig erosion resistance and effect on high cycle fatigue strength. Based on these tests, the following coatings were recommended for engine testing: Gator-Gard plasma spray 88WC-12Co on titanium alloy airfoils, plasma spray 83WC-17Co on steel and nickel alloy airfoils, and Cr+B on nickel alloy airfoils.

  6. Use of Sediment Budgets for Watershed Erosion Control Planning: A Case Study From Northern California

    NASA Astrophysics Data System (ADS)

    O'Connor, M.; McDavitt, W.

    2002-05-01

    Erosion, sedimentation and peak flow increases caused by forest management for commercial timber production may negatively affect aquatic habitat of endangered anadromous fish such as coho salmon ({\\ it O. kisutch}). This paper summarizes a portion of a Watershed Analysis study performed for Pacific Lumber Company, Scotia, CA, focusing on erosion and sedimentation processes and rates and downstream sediment routing and water quality in the Freshwater Creek watershed in northwest California. Hillslope, road and bank erosion, channel sedimentation and sediment rates were quantified using field surveys, aerial photo interpretation, and empirical modeling approaches for different elements of the study. Sediment transport rates for bedload were modeled, and sediment transport rates for suspended sediment were estimated based on size distribution of sediment inputs in relation to sizes transported in suspension. The resulting sediment budget was validated through comparison using recent short-term, high-quality estimates of suspended sediment yield collected by a community watershed group at a downstream monitoring site with technical assistance from the US Forest Service. Another check on the sediment budget was provided by bedload yield data from an adjacent watershed, Jacoby Creek. The sediment budget techniques and bedload routing models used for this study provide sediment yield estimates that are in good agreement with available data. These results suggest that sediment budget techniques that require moderate levels of fieldwork can be used to provide relatively accurate technical assessments for use in the TMDL process. The sediment budget also identifies the most significant sediment sources and suggests a framework within which effective erosion control strategies can be developed.

  7. From structure- to erosion-controlled subsiding calderas: evidence thresholds and mechanics

    NASA Astrophysics Data System (ADS)

    Geshi, Nobuo; Acocella, Valerio; Ruch, Joel

    2012-08-01

    Collapse calderas evolve by increasing their depth/diameter ratio. To properly characterize caldera evolution, a structural S/D (ratio between structural subsidence and ring-fault diameter; S s / D s ), and a topographic S/D (ratio between topographic caldera depth and topographic caldera width; S t / D t ), are considered. We review the evolution of the A.D. 2000 Miyakejima caldera, with two concentric ring faults at earlier collapsing stages, and erosion of its wall, accumulating debris on the floor, at later collapsing stages. While S t / D t and S s / D s show a similar increase at initial stages, when S s / D s ˜0.33 the S s / D s becomes significantly different from S t / D t : while continuous caldera subsidence monotonically increases S s / D s , the erosion of the wall and the filling of the floor decrease S t / D t . This evolution finds close similarities with recent caldera collapses of Krakatau (1883), Katmai (1912), Fernandina (1968), Tolbachik (1975-1976), Pinatubo (1991), and Dolomieu (2007). Analog experiments mimic the observed variation, evolving from a depression controlled by the activity of the double-ring faults to that controlled by the erosion of the wall and sedimentation at the floor. These natural and modeling results show that the control on the shape of mature calderas ( S s / D s > 0.07) and approaching S s / D s = 0.3-0.4 passes from a mainly structural to a mainly erosional control. Both S t / D t and S s / D s are needed to describe the evolution of a collapse and the processes accompanying it. Evaluating S t / D t and S s / D s allows proper description of the precise evolutionary stage of a caldera and of the relative importance of the structural and erosional processes and allows making semiquantitative comparisons between evolutionary stages.

  8. Costs and benefits of urban erosion and sediment control: The North Carolina experience

    NASA Astrophysics Data System (ADS)

    Paterson, Robert G.; Luger, Michael I.; Burby, Raymond J.; Kaiser, Edward J.; Malcom, H. Rooney; Beard, Alicia C.

    1993-03-01

    The EPA’s new nonpoint source pollution control requirements will soon institutionalize urban erosion and sediment pollution control practices nationwide. The public and private sector costs and social benefits associated with North Carolina’s program (one of the strongest programs in the country in terms of implementation authority, staffing levels, and comprehensiveness of coverage) are examined to provide general policy guidance on questions relating to the likely burden the new best management practices will have on the development industry, the likely costs and benefits of such a program, and the feasibility of running a program on a cost recovery basis. We found that urban erosion and sediment control requirements were not particularly burdensome to the development industry (adding about 4% on average to development costs). Public-sector program costs ranged between 2.4 and 4.8 million in fiscal year 1989. Our contingent valuation survey suggests that urban households in North Carolina are willing to pay somewhere between 7.1 and 14.2 million a year to maintain current levels of sediment pollution control. Our benefit-cost analysis suggests that the overall ratio is likely to be positive, although a definitive figure is elusive. Lastly, we found that several North Carolina localities have cost recovery fee systems that are at least partially self-financing.

  9. Can warmwater streams be rehabilitated using watershed-scale standard erosion control measures alone?

    PubMed

    Shields, F Douglas; Knight, Scott S; Cooper, Charles M

    2007-07-01

    Degradation of warmwater streams in agricultural landscapes is a pervasive problem, and reports of restoration effectiveness based on monitoring data are rare. Described is the outcome of rehabilitation of two deeply incised, unstable sand-and-gravel-bed streams. Channel networks of both watersheds were treated using standard erosion control measures, and aquatic habitats within 1-km-long reaches of each stream were further treated by addition of instream structures and planting woody vegetation on banks ("habitat rehabilitation"). Fish and their habitats were sampled semiannually during 1-2 years before rehabilitation, 3-4 years after rehabilitation, and 10-11 years after rehabilitation. Reaches with only erosion control measures located upstream from the habitat measure reaches and in similar streams in adjacent watersheds were sampled concurrently. Sediment concentrations declined steeply throughout both watersheds, with means > or = 40% lower during the post-rehabilitation period than before. Physical effects of habitat rehabilitation were persistent through time, with pool habitat availability much higher in rehabilitated reaches than elsewhere. Fish community structure responded with major shifts in relative species abundance: as pool habitats increased after rehabilitation, small-bodied generalists and opportunists declined as certain piscivores and larger-bodied species such as centrarchids and catostomids increased. Reaches without habitat rehabilitation were significantly shallower, and fish populations there were similar to the rehabilitated reaches prior to treatment. These findings are applicable to incised, warmwater streams draining agricultural watersheds similar to those we studied. Rehabilitation of warmwater stream ecosystems is possible with current knowledge, but a major shift in stream corridor management strategies will be needed to reverse ongoing degradation trends. Apparently, conventional channel erosion controls without instream habitat

  10. Monsoonal versus Anthropogenic Controls on Erosion Patterns and Sediment Flux in the Song Gianh, Vietnam

    NASA Astrophysics Data System (ADS)

    Clift, Peter; Jonell, Tara; Carter, Andrew; Van Hoang, Long; Böning, Philipp

    2016-04-01

    The Song Gianh is a small drainage on the northern central coast of Vietnam that delivers sediment into the Gulf of Tonkin. The basin provides the opportunity to evaluate what surface processes control continental erosion rates and patterns because there is a strong monsoonal precipitation gradient from the SW to NE. We apply several complimentary provenance methods to modern siliciclastic sediments of the Song Gianh to pinpoint regions of focused sediment generation and evaluate how sediment is mixed downstream and delivered to the ocean. We find that detrital zircon populations of Song Gianh main channel change radically downstream of the confluence with the northern Rao Tro tributary, which is dominated by 100-300 Ma grains eroded from granite bedrock. This tributary provides almost as much zircon to the main channel as all the headwater tributaries combined, despite being a much smaller, drier, and flatter sub-basin. In contrast, bulk sediment Nd and Sr isotopes indicate that most sediment is derived from the wetter headwater tributaries. Contribution from the southern tributaries to the net siliciclastic river flux is negligible. Precipitation and topography do not appear to modulate zircon production in the modern river although regions controlling bulk Nd and Sr compositions are wetter and have higher local relief. This apparent contrast in regions of sediment production suggests disequilibrium and differential travel times for zircon and mineral phases rich in Nd and Sr. Optically Stimulated Luminescence (OSL) dating of alluvial terraces on the main channel show that the valleys aggraded rapidly from ~7-9 ka during a period of strong summer monsoon, suggesting that heavy rainfall generated large sediment volumes. Younger terraces dated to 500-1000 yrs BP are interpreted to reflect erosion and aggradation driven by extensive human agriculture. We speculate that agriculture, together with bedrock compositions, are the most likely control on producing the

  11. Corrective measures technology for shallow land burial at arid sites: field studies of biointrusion barriers and erosion control

    SciTech Connect

    Nyhan, J.W.; Hakonson, T.E.; Lopez, E.A.

    1986-03-01

    The field research program involving corrective measures technologies for arid shallow land burial (SLB) sites is described. Results of field testing of a biointrusion barrier installed at a close-out waste disposal site (Area B) at Los Alamos are presented. Soil erosion and infiltration of water into a simulated trench cap with various surface treatments were measured, and the interaction between erosion control and subsurface water dynamics is discussed relative to waste management.

  12. INNOVATIVE IN-SITU REMEDIATION OF CONTAMINATED SEDIMENTS FOR SIMULTANEOUS CONTROL OF CONTAMINATION AND EROSION

    SciTech Connect

    Knox, A; Michael Paller, M; Danny D. Reible, D; Ioana G. Petrisor, I

    2007-11-28

    New technologies are needed that neutralize contaminant toxicity and control physical transport mechanisms that mobilize sediment contaminants. The last 12 months of this comprehensive project investigated the use of combinations of sequestering agents to develop in situ active sediment caps that stabilize mixtures of contaminants and act as a barrier to mechanical disturbance under a broad range of environmental conditions. Efforts focused on the selection of effective sequestering agents for use in active caps, the composition of active caps, and the effects of active cap components on contaminant bioavailability and retention. Results from this project showed that phosphate amendments, some organoclays, and the biopolymer, chitosan, were very effective at removing metals from both fresh and salt water. These amendments also exhibited high retention (80% or more) of most metals indicating reduced potential for remobilization to the water column. Experiments on metal speciation and retention in contaminated sediment showed that apatite and organoclay can immobilize a broad range of metals under both reduced and oxidized conditions. These studies were followed by sequential extractions to evaluate the bioavailability and retention of metals in treated sediments. Metal fractions recovered in early extraction steps are more likely to be bioavailable and were termed the Potentially Mobile Fraction (PMF). Less bioavailable fractions collected in later extraction steps were termed the Recalcitrant Factor (RF). Apatite and organoclay reduced the PMF and increased the RF for several elements, especially Pb, Zn, Ni, Cr, and Cd. Empirically determined partitioning coefficients and modeling studies were used to assess the retention of organic contaminants on selected sequestering agents. Organoclays exhibited exceptionally high sorption of polycyclic aromatic hydrocarbons as indicated by a comparison of K{sub d} values among 12 amendments. These results suggested that

  13. Factors controlling gully erosion at different spatial and temporal scales in rangelands of SW Spain

    NASA Astrophysics Data System (ADS)

    Gómez Gutiérrez, Á.; Schnabel, S.; Lavado Contador, J. F.; Pulido Fernández, M.

    2009-04-01

    Mediterranean climate with Atlantic influences. Results showed that at the catchment scale, and for a short period (1-10 years), rainfall and soil moisture were the most important factors controlling gully erosion rates. In fact, gully erosion was highly related with the rainfall amount (r=0,90), with the number of times event discharge exceeded 1000 cubic meters (r=0,76) and with the number of times peak discharge exceeded 100 l/s (r=0,72). However, when the temporal scale was extended to several decades (from 1945 to 2006), land use and vegetation cover (specially the extension of cultivated area and livestock density) proved to be the most important factors determining the area affected by gullying. With respect to the spatial variation of gullying at the regional scale, the model results indicate lithology as being the most important variable, followed by vegetation structure and summer rainfall. This model was able to explain a large portion of the spatial distribution of gullies at the regional scale. Concluding, at different spatial and temporal scales the importance of factors which determine gully erosion intensity, extension and rates varies notably. At the short-term rainfall and runoff dynamics and the moisture content of the sediments are the dominant factors, whereas at the medium-term land use and vegetation cover become more important. At the regional scale lithology and vegetation turned out to be the dominant factors in determining the location of areas susceptible to gully erosion in rangelands of Extremadura.

  14. Erosion rates as a potential bottom-up control of forest structural characteristics in the Sierra Nevada Mountains.

    PubMed

    Milodowski, David T; Mudd, Simon M; Mitchard, Edward T A

    2015-01-01

    The physical characteristics of landscapes place fundamental constraints on vegetation growth and ecosystem function. In actively eroding landscapes, many of these characteristics are controlled by long-term erosion rates: increased erosion rates generate steeper topography and reduce the depth and extent of weathering, limiting moisture storage capacity and impacting nutrient availability. Despite the potentially important bottom-up control that erosion rates place on substrate characteristics, the relationship between the two is largely unexplored. We investigate spatial variations in aboveground biomass (AGB) across a structurally diverse mixed coniferous/deciduous forest with an order of magnitude erosion-rate gradient in the Northern Californian Sierra Nevada, USA, using high resolution LiDAR data and field plots. Mean basin slope, a proxy for erosion rate, accounts for 32% of variance in AGB within our field area (P < 0.001), considerably outweighing the effects of mean annual precipitation, temperature, and bedrock lithology. This highlights erosion rate as a potentially important, but hitherto unappreciated, control on AGB and forest structure.

  15. Robotic weld overlay coatings for erosion control. [Quarterly report, July--September 1993

    SciTech Connect

    Levin, B.F.; DuPont, J.N.; Marder, A.R.

    1993-10-20

    In the previous period of work, twelve overlay hardfacing alloys were selected for erosion testing based upon a literature review. All twelve coatings were deposited on 1018 steel substrates using the plasma arc welding process. Ten samples from each coating were prepared for erosion testing. The coating deposition and sample preparation procedures were described in the previous quarterly report. During the past quarter, all the coatings were erosion tested at 400 C. The erosion resistance of each coating was evaluated by determining the steady state erosion rate. In addition, the microstructure of each coating was characterized before and after the erosion tests. This progress report describes the erosion test results and coating microstructures. Also, a preliminary analysis on the relationships, between weld overlay coating hardness, microstructure, and erosion resistance will be discussed.

  16. Event-based design tool for construction site erosion and sediment controls

    NASA Astrophysics Data System (ADS)

    Trenouth, William R.; Gharabaghi, Bahram

    2015-09-01

    This paper provides additional discussion surrounding the novel event-based soil loss models developed by Trenouth and Gharabaghi (2015) for the design of erosion and sediment controls (ESCs) for various phases of construction - from pre-development to post-development conditions. The datasets for the study were obtained from three Ontario sites - Greensborough, Cookstown, and Alcona - in addition to datasets mined from the literature for three additional sites - Treynor, Iowa, Coshocton, Ohio and Cordoba, Spain. Model performances were evaluated for each of the study sites, and quantified using commonly-reported statistics. This work is nested within a broader conceptual framework, which includes the estimation of ambient receiving water quality, the prediction of event mean runoff quality for a given design storm, and the calculation of the required level of protection using adequate ESCs to meet receiving water quality guidelines. These models allow design engineers and regulatory agencies to assess the potential risk of ecological damage to receiving waters due to inadequate soil erosion and sediment control practices using dynamic scenario forecasting when considering rapidly changing land use conditions during various phases of construction, typically for a 2- or 5-year design storm return period.

  17. Ecosystem services in Mediterranean river basin: climate change impact on water provisioning and erosion control.

    PubMed

    Bangash, Rubab F; Passuello, Ana; Sanchez-Canales, María; Terrado, Marta; López, Alfredo; Elorza, F Javier; Ziv, Guy; Acuña, Vicenç; Schuhmacher, Marta

    2013-08-01

    The Mediterranean basin is considered one of the most vulnerable regions of the world to climate change and such changes impact the capacity of ecosystems to provide goods and services to human society. The predicted future scenarios for this region present an increased frequency of floods and extended droughts, especially at the Iberian Peninsula. This paper evaluates the impacts of climate change on the water provisioning and erosion control services in the densely populated Mediterranean Llobregat river basin of. The assessment of ecosystem services and their mapping at the basin scale identify the current pressures on the river basin including the source area in the Pyrenees Mountains. Drinking water provisioning is expected to decrease between 3 and 49%, while total hydropower production will decrease between 5 and 43%. Erosion control will be reduced by up to 23%, indicating that costs for dredging the reservoirs as well as for treating drinking water will also increase. Based on these data, the concept for an appropriate quantification and related spatial visualization of ecosystem service is elaborated and discussed.

  18. Influence of gully erosion control on amphibian and reptile communities within riparian zones of channelized streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Riparian zones of streams in northern Mississippi have been impacted by agriculture, channelization, channel incision, and gully erosion. Gully erosion is the most severe form of erosion and has resulted in the fragmentation of remnant riparian zones within agricultural watersheds. One widely used c...

  19. Influence of Gully Erosion Control on Amphibian and Reptile Communities Within Riparian Zones of Channelized Streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Riparian zones of streams in northern Mississippi have been impacted by agriculture, channelization, channel incision, and gully erosion. Gully erosion is the most severe form of erosion and has resulted in the fragmentation of remnant riparian zones within agricultural watersheds. One widely used c...

  20. Potential controls of alluvial bench deposition and erosion in southern Piedmont streams, Alabama (USA)

    NASA Astrophysics Data System (ADS)

    Haney, Nicholas R.; Davis, Lisa

    2015-07-01

    Benches are bank-attached channel deposits occurring at an elevation between the channel bed and top of banks. Their occurrence in a variety of geologic and hydrologic settings has led to confusion about the mechanisms driving their formation, which in turn contributes to difficulty identifying the active floodplain, bankfull stage, and the determination of environmental flows in some rivers. Hydrodynamic modeling software (River 2D), in combination with sediment particle size analysis and total station topographic surveys, was used to simulate flow conditions needed to erode and deposit the D84, D50, and D15 particle sizes of concave and lateral benches in two rivers (Talladega and Hillabee creeks) in Alabama. Results suggest that bench erosion requires flows at least 150% larger than benchfull stage at the Talladega site, while the Hillabee site experienced erosion at all discharges meeting and exceeding benchfull flow stage, likely owing to its overall smaller sediment particle sizes. At both sites, the presence of vegetation increased the bench area subjected to deposition but, somewhat counterintuitively, also helped influence the location of erosion by limiting flow vectors. In contrast with previous research findings, the occurrence of reverse flow was neither sustained nor widespread at either site. These findings provide new insight into alluvial benches, suggest that the study benches are relatively stable features under the prevailing hydrologic regime, and that in some temperate climate settings, such as the southern Piedmont, localized hydraulic controls on bench formation can be superseded in importance by hydrologic flow regime, even in the case of concave benches and where flow regulation is not a factor.

  1. Soil tillage conservation and its effect on erosion control, water management and carbon sequestration

    NASA Astrophysics Data System (ADS)

    Rusu, T.; Gus, P.; Bogdan, I.; Moraru, P.; Pop, A.; Clapa, D.; Pop, L.

    2009-04-01

    fuel for preparing the germination bed. Presently it is necessary a change concerning the concept of conservation practices and a new approach regarding the control of erosion. The real conservation of soil must be expanded beyond the traditional understanding of soil erosion. The real soil conservation is represented by carbon management. We need to focus to another level concerning conservation by focusing on of soil quality. Carbon management is necessary for a complex of matters including soil, water management, field productivity, biological fuel and climatic change.

  2. Soil tillage conservation and its effect on erosion control, water management and carbon sequestration

    NASA Astrophysics Data System (ADS)

    Rusu, Dr.; Gus, Dr.; Bogdan, Dr.; Moraru, Dr.; Pop, Dr.; Clapa, Dr.; Pop, Drd.

    2009-04-01

    fuel for preparing the germination bed. Presently it is necessary a change concerning the concept of conservation practices and a new approach regarding the control of erosion. The real conservation of soil must be expanded beyond the traditional understanding of soil erosion. The real soil conservation is represented by carbon management. We need to focus to another level concerning conservation by focusing on of soil quality. Carbon management is necessary for a complex of matters including soil, water management, field productivity, biological fuel and climatic change. Profound research is necessary in order to establish the carbon sequestration practices and their implementation impact.

  3. Robotic weld overlay coatings for erosion control. Final technical progress report, July 1992--July 1995

    SciTech Connect

    Levin, B.F.; DuPont, J.N.; Marder, A.R.

    1995-10-15

    The erosion behavior of weld overlay coatings has been studied. Eleven weld overlay alloys were deposited on 1018 steel substrates using the plasma arc welding process and erosion tested at 400{degrees}C at 90{degrees} and 30{degrees} particle impact angles. The microstructure of each coating was characterized before erosion testing. A relative ranking of the coatings erosion resistance was developed by determining the steady state erosion rates. Ultimet, Inconel-625, and 316L SS coatings showed the best erosion resistance at both impact angles. It was found that weld overlays that exhibit good abrasion resistance did not show good erosion resistance. Erosion tests were also performed for selected wrought materials with chemical composition similar to weld overlays. Eroded surfaces of the wrought and weld alloys were examined by Scanning Electron Microscopy (SEM). Microhardness tests were performed on the eroded samples below the erosion surface to determine size of the plastically deformed region. It was found that one group of coatings experienced significant plastic deformation as a result of erosion while the other did not. It was also established that, in the steady state erosion regime, the size of the plastically deformed region is constant.

  4. Validation of Erosion 3D in Lower Saxony - Comparison between modelled soil erosion events and results of a long term monitoring project

    NASA Astrophysics Data System (ADS)

    Bug, Jan; Mosimann, Thomas

    2013-04-01

    Since 2000 water erosion has been surveyed on 400 ha arable land in three different regions of Lower Saxony (Mosimann et al. 2009). The results of this long-term survey are used for the validation of the soil erosion models such as USLE and Erosion 3D. The validation of the physically-based model Erosion 3D (Schmidt & Werner 2000) is possible because the survey analyses the effects (soil loss, sediment yield, deposition on site) of single thunder storm events and also maps major factors of soil erosion (soil, crop, tillage). A 12.5 m Raster DEM was used to model the soil erosion events.Rainfalldata was acquired from climate stations. Soil and landuse parameters were derived from the "Parameterkatalog Sachsen"(Michael et al. 1996). During thirteen years of monitoring, high intensity storms fell less frequently than expected. High intensity rainfalls with a return period of five or ten years usually occurred during periods of maximum plant cover.Winter events were ruled out because dataon snow melt and rainfallwere not measured. The validation is therefore restricted to 80 events. The validation consists of three parts. The first part compares the spatial distribution of the mapped soil erosion with the model results. The second part calculates the difference in the amount of redistributed soil. The third part analyses off-site effects such as sediment yield and pollution of water bodies. The validation shows that the overall result of erosion 3D is quite good. Spatial hotspots of soil erosion and of off-site effects are predicted correctly in most cases. However, quantitative comparison is more problematic, because the mapping allows only the quantification of rillerosion and not of sheet erosion. So as a rule,the predicted soil loss is higher than the mapped. The prediction of rill development is also problematic. While the model is capable of predicting rills in thalwegs, the modelling of erosion in tractor tracks and headlands is more complicated. In order to

  5. Cropping systems and control of soil erosion in a Mediterranean environment

    NASA Astrophysics Data System (ADS)

    Cosentino, Salvatore; Copani, Venera; Testa, Giorgio; Scalici, Giovanni

    2013-04-01

    The research has been carried out over the years 1996-2010 in an area of the internal hill of Sicily region (Enna, c.da Geracello, 550 m a. s. l. 37° 23' N. Lat, 14° 21' E. Long) in the center of Mediterranean Sea, mainly devoted to durum wheat cultivation, using the experimental plots, established in 1996 on a slope of 26-28%, equipped to determine surface runoff and soil losses. The establishment consists of twelve plots, having 40 m length and 8 m width. In order to study the effect of different field crop systems in controlling soil erosion in slopes subjected to water erosion, the following systems were studied: permanent crops, tilled annual crops, no-tilled annual crops, set-aside. The used crops were: durum wheat, faba bean, rapeseed, subterranean clover, Italian ryegrass, alfalfa, sweetvetch, moon trefoil, barley, sweet sorghum, sunflower. The results pointed out that the cropping systems with perennial crops allowed to keep low the soil loss, while annual crop rotation determined a high amount of soil loss. Sod seeding showed promising results also for annual crop rotations.

  6. Toxicity of anionic polyacrylamide formulations when used for erosion control in agriculture.

    PubMed

    Weston, Donald P; Lentz, Rodrick D; Cahn, Michael D; Ogle, R Scott; Rothert, Amanda K; Lydy, Michael J

    2009-01-01

    Addition of anionic polyacrylamide (PAM) to agricultural irrigation water can dramatically reduce erosion of soils. However, the toxicity of PAM to aquatic life, while often claimed to be low, has not been thoroughly evaluated. Five PAM formulations, including two oil-based products, one water-based product, one granular product and one tablet product, were evaluated for acute and/or chronic toxicity to five species commonly used for freshwater toxicity testing [Hyalella azteca (Saussure), Chironomus dilutus (Shobanov et al.), Ceriodaphnia dubia (Richard), Pimephales promelas (Rafinesque), and Selenastrum capricornutum (Printz)]. When applied as an oil-based product, acute toxicity was seen to four of the five species at concentrations less than the 10 mg/L that is often used for erosion control. Toxicity was diminished, but still remained, after passage of the irrigation water across an agricultural field, indicating a potential impact to nearby surface waters. Results from the non-oil-based products indicated minimal toxicity associated with PAM even at concentrations 10 times those used in agriculture when applied in the granular form, as a tablet, or in a water-based liquid. These data suggest that other agents in the oil-based products, such as surfactants or emulsifiers, rather than the PAM itself, contribute to the toxicity. Care is required in selecting an appropriate PAM formulation when the potential exists for entry of tailwater to nearby surface waters.

  7. In Situ analysis of CO2 laser irradiation on controlling progression of erosive lesions on dental enamel.

    PubMed

    Lepri, Taísa Penazzo; Scatolin, Renata Siqueira; Colucci, Vivian; De Alexandria, Adílis Kalina; Maia, Lucianne Cople; Turssi, Cecília Pedroso; Corona, Silmara Aparecida Milori

    2014-08-01

    The present study aimed to evaluate in situ the effect of CO2 laser irradiation to control the progression of enamel erosive lesions. Fifty-six slabs of bovine incisors enamel (5 × 3 × 2.5 mm(3) ) were divided in four distinct areas: (1) sound (reference area), (2) initial erosion, (3) treatment (irradiated or nonirradiated with CO2 laser), (4) final erosion (after in situ phase). The initial erosive challenge was performed with 1% citric acid (pH = 2.3), for 5 min, 2×/day, for 2 days. The slabs were divided in two groups according to surface treatment: irradiated with CO2 laser (λ = 10.6 µm; 0.5 W) and nonirradiate. After a 2-day lead-in period, 14 volunteers wore an intraoral palatal appliance containing two slabs (irradiated and nonirradiated), in two intraoral phases of 5 days each. Following a cross-over design during the first intraoral phase, half of the volunteers immersed the appliance in 100 mL of citric acid for 5 min, 3×/day, while other half of the volunteers used deionized water (control). The volunteers were crossed over in the second phase. Enamel wear was determined by an optical 3D profilometer. Three-way ANOVA for repeated measures revealed that there was no significant interaction between erosive challenge and CO2 laser irradiation (P = 0.419). Erosive challenge significantly increased enamel wear (P = 0.001), regardless whether or not CO2 laser irradiation was performed. There was no difference in enamel wear between specimens CO2 -laser irradiated and non-irradiated (P = 0.513). Under intraoral conditions, CO2 laser irradiation did not control the progression of erosive lesions in enamel caused by citric acid.

  8. Open Innovation and the Erosion of the Traditional Information Systems Project's Boundaries

    NASA Astrophysics Data System (ADS)

    Elbanna, Amany

    This paper examines the notion of open innovation and its implication on information systems management. It investigates a project of an enterprise resource planning system implementation in an international organization to unravel the resemblance with the open innovation model. The study shows that the conceptualization of ERP project as an open innovation could reveal the complex architecture of today's organization from which the ERP project cannot be isolated. It argues that the traditional boundaries around IS projects are dissolving and the relationship between what used to be outside and what used to be inside the project is increasingly blurred. The study calls for a different perspective of project management that goes beyond single and multiple project management to scan the open space of innovation and actively look for partners, competitors, and collaborators.

  9. NASA's Evolutionary Xenon Thruster (NEXT) Project Qualification Propellant Throughput Milestone: Performance, Erosion, and Thruster Service Life Prediction After 450 kg

    NASA Technical Reports Server (NTRS)

    Herman, Daniel A.

    2010-01-01

    The NASA s Evolutionary Xenon Thruster (NEXT) program is tasked with significantly improving and extending the capabilities of current state-of-the-art NSTAR thruster. The service life capability of the NEXT ion thruster is being assessed by thruster wear test and life-modeling of critical thruster components, such as the ion optics and cathodes. The NEXT Long-Duration Test (LDT) was initiated to validate and qualify the NEXT thruster propellant throughput capability. The NEXT thruster completed the primary goal of the LDT; namely to demonstrate the project qualification throughput of 450 kg by the end of calendar year 2009. The NEXT LDT has demonstrated 28,500 hr of operation and processed 466 kg of xenon throughput--more than double the throughput demonstrated by the NSTAR flight-spare. Thruster performance changes have been consistent with a priori predictions. Thruster erosion has been minimal and consistent with the thruster service life assessment, which predicts the first failure mode at greater than 750 kg throughput. The life-limiting failure mode for NEXT is predicted to be loss of structural integrity of the accelerator grid due to erosion by charge-exchange ions.

  10. The effectiveness of jute and coir blankets for erosion control in different field and laboratory conditions

    NASA Astrophysics Data System (ADS)

    Kalibová, Jana; Jačka, Lukáš; Petrů, Jan

    2016-03-01

    Vegetation cover is found to be an ideal solution to most problems of erosion on steep slopes. Biodegradable geotextiles (GTXs) have been proved to provide sufficient protection against soil loss in the period before vegetation reaches maturity, so favouring soil formation processes. In this study, 500 g m-2 jute (J500), 400 g m-2 (C400), and 700 g m-2 coir (C700) GTXs were first installed on a 9° slope under "no-infiltration" laboratory conditions, then on a 27° slope under natural field conditions. The impact of GTXs on run-off and soil loss was investigated to compare the performance of GTXs under different conditions. Laboratory run-off ratio (percentage portion of control plot) equalled 78, 83, and 91 %, while peak discharge ratio equalled 83, 91, and 97 % for J500, C700, and C400 respectively. In the field, a run-off ratio of 31, 62, and 79 %, and peak discharge ratio of 37, 74, and 87 % were recorded for C700, J500, and C400 respectively. All tested GTXs significantly decreased soil erosion. The greatest soil loss reduction in the field was observed for J500 (by 99.4 %), followed by C700 (by 97.9 %) and C400 (by 93.8 %). Irrespective of slope gradient or experimental condition, C400 performed with lower run-off and peak discharge reduction than J500 and C700. The performance ranking of J500 and C700 in the laboratory differed from the field, which may be explained by different slope gradients, and also by the role of soil, which was not included in the laboratory experiment.

  11. Factors controlling erosion/deposition phenomena related to lahars at Volcán de Colima, Mexico

    NASA Astrophysics Data System (ADS)

    Vázquez, Rosario; Capra, Lucia; Coviello, Velio

    2016-08-01

    One of the most common phenomena at Volcán de Colima is the annual development of lahars that runs mainly through the southern ravines of the edifice. Since 2011 the study and the monitoring of these flows and of the associated rainfall has been achieved by means of an instrumented station located along the Montegrande ravine, together with the systematic surveying of cross-topographic profiles of the main channel. From these, we present the comparison of the morphological changes experimented by this ravine during the 2013, 2014 and 2015 rainy seasons. The erosion/deposition effects of 11 lahars that occurred during this period of time were quantified by means of the topographic profiles taken at the beginning and at the end of the rainy seasons and before and after the major lahar event of 11 June 2013. We identified (i) an erosive zone between 2100 and 1950 m a.s.l., 8° in slope, with an annual erosional rate of 10.3 % mainly due to the narrowness of the channel and to its high slope angle and (ii) an erosive-depositional zone, between 1900 and 1700 m a.s.l., ( ˜ 8 % erosion and ˜ 16 % deposition), characterized by a wider channel that decreases in slope angle (4°). Based on these observations, the major factors controlling the erosion/deposition rates in the Montegrande ravine are the morphology of the gully (i.e., channel bed slope and the cross section width) and the joint effect of sediment availability and accumulated rainfall. On the distal reach of the ravine, the erosion/deposition processes tend to be promoted preferentially one over the other, mostly depending on the width of the active channel. Only for extraordinary rainfall events are the largest lahars mostly erosive all along the ravine up to the distal fan where the deposition takes place. In addition, as well as the morphological characteristics of the ravine, the flow depth is a critical factor in controlling erosion, as deeper flows will promote erosion against deposition. Finally, by

  12. Integrated watershed management for saturation excess generated runoff, erosion and nutrient control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding the basic hydrology and erosion is vital for effective management and utilization of water resources and soil conservation planning. An important question for judging effectiveness of soil and water conservation practices is whether runoff erosion and nutrient loss is affected by infil...

  13. The Streambank Erosion Control Evaluation and Demonstration Act of 1974, Section 32, Public Law 93-251. Main Report.

    DTIC Science & Technology

    1981-12-01

    Conservation Service . Demonstration Projects on Other Streams, Nationwide (Work Unit 8) A variety of streambank protection methods and materials were...participated in the 1969 study, particularly the Soil Conservation Service , also contributed to the new evaluation of extent of streambank erosion...Denver, Colorado.) U. S. Department of Agriculture, Soil Consersation Service (SCS) and Science and Education Administration (SEA) A survey was made of

  14. Weld overlay coatings for erosion control. Task A: Literature review, progress report

    SciTech Connect

    Levin, B.; DuPont, J.N.; Marder, A.R.

    1993-03-03

    A literature review was made. In spite of similarities between abrasive wear and solid particle erosion, weld overlay hardfacing alloys that exhibit high abrasion resistance may not necessarily have good erosion resistance. The performance of weld overlay hardfacing alloys in erosive environments has not been studied in detail. It is believed that primary-solidified hard phases such as carbides and intermetallic compounds have a strong influence on erosion resistance of weld overlay hardfacing alloys. However, relationships between size, shape, and volume fraction of hard phases in a hardfacing alloys and erosion resistance were not established. Almost all hardfacing alloys can be separated into two major groups based upon chemical compositions of the primary solidified hard phases: (a) carbide hardening alloys (Co-base/carbide, WC-Co and some Fe base superalloys); and (b) intermetallic hardening alloys (Ni-base alloys, austenitic steels, iron-aluminides).

  15. Influence of Gully Erosion Control on Amphibian and Reptile Communities within Riparian Zones of Channelized Streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Riparian zones of streams in northwestern Mississippi have been impacted by agriculture, channelization, channel incision, and gully erosion. Riparian gully formation has resulted in the fragmentation of remnant riparian zones within agricultural watersheds. One widely used conservation practice for...

  16. Holocene Fire, Climate and Erosion in the Jemez Mountains, New Mexico: Natural and Anthropogenic Controls

    NASA Astrophysics Data System (ADS)

    Meyer, G. A.; Fitch, E. P.

    2013-12-01

    Ponderosa pine and mixed-conifer forests in the Jemez Mountains have been ravaged by extensive severe fires in the last two decades, which burned almost 1000 km2, roughly 30% of this middle-elevation range. Tree-ring fire history reconstructions indicate that a low-severity fire regime characterized the ca. 400 years before Euroamerican settlement, and that fuel buildup from fire suppression and land-use impacts contributed to increased fire severity in recent years. In order to better understand natural variability, climatic influences, and erosional effects of wildfire activity since ~5000 cal yr BP, we identified and 14C-dated fire-related alluvial deposits in the 2002 Lakes Fire area in the southwestern Jemez Mountains. These deposits indicate that most late Holocene fire-related erosional events were relatively minor, consistent with the low-severity burns that dominate the tree-ring record, but larger debris flows also occurred, suggesting at least small areas of high-severity fire. Although changes in postfire sedimentation are not so clearly related to millennial-scale Holocene climatic changes as in the Northern Rocky Mountains, peaks in fire-event probability correspond with severe regional multidecadal droughts ca. 1800 and 375 cal yr BP. Local microclimatic controls on vegetation, soils, and post-fire sedimentation are also evident. Relatively dense mixed-conifer stands including Douglas-fir typify moister north-facing basins, where soils are apparently thicker and more permeable than on southerly aspects. Alluvial fans of these basins are dominated by fire-related deposits (77% of measured stratigraphic thickness), thus we interpret that little erosion occurs in the absence of wildfires. Holocene fire-related events from north slopes are also of somewhat lower frequency, and possibly of higher severity. In contrast, in ponderosa pine-dominated south-facing basins, fire-related deposits make up only 39% of measured fan deposits. On drier south aspects

  17. Stormwater control measure (SCM) design standards to limit stream erosion for Piedmont North Carolina

    NASA Astrophysics Data System (ADS)

    Tillinghast, E. D.; Hunt, W. F.; Jennings, G. D.

    2011-12-01

    SummaryThis study evaluated the potential impacts of sub-bankfull flows produced by stormwater control measures (SCMs) on stream geomorphic stability. In part, design standards for SCMs include peak flow attenuation to maintain pre-development flow conditions to those of undeveloped watersheds or return urbanized, developed watersheds back to the pre-developed state. Most SCMs target lower frequency storms, usually the 2-and/or 10-year discharge events, but leave peak flows resulting from higher frequency storms uncontrolled. SCMs are possibly subjecting streams to longer and more frequent periods of erosion, increasing stream channel instability. The d65 substrate size, pattern, profile, and dimension of 33 reference stream cross-sections in Piedmont North Carolina were modeled using the continuous simulations program, SWMM, to develop (1) a unit critical discharge metric in L/s/ha, Q c = 0.0035( d65) 1.5048, (2) allowable annual erosional hour standard, Log(AAEH) = -1.26Log( d65) + 1.21, and (3) allowable volume of eroded bedload standard, Log(AV) = -0.64( Q c) - 1.52, for watersheds containing SCMs discharging into surface waters. The unit critical discharge represents a threshold that, once exceeded, incipient motion of the d65 particle can occur. These standards represented benchmarks of stable, naturally eroding reference streams. Ninety-four percent of the unit critical discharges were less than the 2-year 24-h event, indicating the necessity of controlling higher frequency sub-bankfull flows. The standards were applied to an urbanized watershed (one sub-catchment containing a structural SCM and two sub-catchments without) in Raleigh, North Carolina. The unit critical discharge metric appeared to adequately represent urbanized stream geomorphic processes for the sub-catchment undergoing urbanization (4.5% difference) but not for the mature urbanized sub-catchments (47.5% and 68.8% difference). Depending on the long-term management goal of the unstable stream

  18. Version Control in Project-Based Learning

    ERIC Educational Resources Information Center

    Milentijevic, Ivan; Ciric, Vladimir; Vojinovic, Oliver

    2008-01-01

    This paper deals with the development of a generalized model for version control systems application as a support in a range of project-based learning methods. The model is given as UML sequence diagram and described in detail. The proposed model encompasses a wide range of different project-based learning approaches by assigning a supervisory…

  19. Barrier erosion control test plan: Gravel mulch, vegetation, and soil water interactions

    SciTech Connect

    Waugh, W.J.; Link, S.O. )

    1988-07-01

    Soil erosion could reduce the water storage capacity of barriers that have been proposed for the disposal of near-surface waste at the US Department of Energy's Hanford Site. Gravel mixed into the top soil surface may create a self-healing veneer that greatly retards soil loss. However, gravel admixtures may also enhance infiltration of rainwater, suppress plant growth and water extraction, and lead to the leaching of underlying waste. This report describes plans for two experiments that were designed to test hypotheses concerning the interactive effects of surface gravel admixtures, revegetation, and enhanced precipitation on soil water balance and plant abundance. The first experiment is a factorial field plot set up on the site selected as a soil borrow area for the eventual construction of barriers. The treatments, arranged in a a split-split-plot design structure, include two densities of gravel admix, a mixture of native and introduced grasses, and irrigation to simulate a wetter climate. Changes in soil water storage and plant cover are monitored with neutron moisture probes and point intercept sampling, respectively. The second experiment consists of an array of 80 lysimeters containing several different barrier prototypes. Surface treatments are similar to the field-plot experiment. Drainage is collected from a valve at the base of each lysimeter tube, and evapotranspiration is estimated by subtraction. The lysimeters are also designed to be coupled to a whole-plant gas exchange system that will be used to conduct controlled experiments on evapotranspiration for modeling purposes. 56 refs., 6 figs., 8 tabs.

  20. Erosion Effects

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    The impact crater in this THEMIS image is a model illustration to the effects of erosion on Mars. The degraded crater rim and several landslides observed in crater walls is evidence to the mass wasting of materials. Layering in crater walls also suggests the presence of materials that erode at varying rates.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

    Image information: VIS instrument. Latitude 31.6, Longitude 44.3 East (315.7 West). 19 meter/pixel resolution.

  1. Effects of aridity in controlling the magnitude of runoff and erosion after wildfire

    NASA Astrophysics Data System (ADS)

    Noske, Philip J.; Nyman, Petter; Lane, Patrick N. J.; Sheridan, Gary J.

    2016-06-01

    This study represents a uniquely high-resolution observation of postwildfire runoff and erosion from dry forested uplands of SE Australia. We monitored runoff and sediment load, and temporal changes in soil surface properties from two (0.2-0.3 ha) dry forested catchments burned during the 2009 Black Saturday wildfire. Event-based surface runoff to rainfall ratios approached 0.45 during the first year postwildfire, compared to reported values <0.01 for less arid hillslopes. Extremely high runoff ratios in these dry forests were attributed to wildfire-induced soil water repellency and inherently low hydraulic conductivity. Mean ponded hydraulic conductivity ranged from 3 to 29 mm h-1, much lower than values commonly reported for wetter forest. Annual sediment yields peaked at 10 t ha-1 during the first year before declining dramatically to background levels, suggesting high-magnitude erosion processes may become limited by sediment availability on hillslopes. Small differences in aridity between equatorial and polar-facing catchments produced substantial differences in surface runoff and erosion, most likely due to higher infiltration and surface roughness on polar-facing slopes. In summary, the results show that postwildfire erosion processes in Eucalypt forests in south-east Australia are highly variable and that distinctive response domains within the region exist between different forest types, therefore regional generalizations are problematic. The large differences in erosion processes with relatively small changes in aridity have large implications for predicting hydrologic-driven geomorphic changes, land degradation, and water contamination through erosion after wildfire across the landscape.

  2. Environmental Control Unit Harness Project

    NASA Technical Reports Server (NTRS)

    Oliva-Buisson, Yvette J.

    2014-01-01

    Testing four new Environmental Control Unit Harnesses for improved user comfort during SCAPE operations. Phase I, testing in a lab environment, Phase II will continue testing the best candidates in a field environment.

  3. Robotic weld overlay coatings for erosion control. Quarterly technical progress report, April 1993--June 1993

    SciTech Connect

    Levin, B.F.; Dupont, J.N.; Marder, A.R.

    1993-07-20

    Twelve weld overlay hardfacing alloys have been selected for preliminary erosion testing based upon a literature review. Four of the selected coatings were deposited on a 1018 steel substrate using plasma arc welding process. During the past quarter, the remaining eight coatings were deposited in the same manner. Ten samples from each coatings were prepared for erosion testing. Microstructural characterization of each coating is in progress. This progress report describes coating deposition and sample preparation procedures. Relation between coatings hardness and formation of cracks in coatings is discussed.

  4. Chronic erosion in Wissant Bay coast, northern France - Causes and trials of management projects

    NASA Astrophysics Data System (ADS)

    Sedrati, M.; Anthony, E. J.

    2012-04-01

    Cape Gris Nez to the southwest and Cape Blanc Nez to the northeast limit's Wissant Bay. This extreme northern coast of France, facing the Dover Strait, is one of the most rapidly eroding sector of coast in France. Shoreline retreat has exceeded 250 m in the last fifty years in the central and western parts of the bay, while the eastern sector of the bay is now a zone of accretion, after being a sand-starved zone in the past, when the western sector was either stable or in accretion. The reasons for these changes are still not clear. They seem to involve interactions between a nearshore sand bank and the activity of current gyres related to the projecting headland of Cape Gris Nez, beach rotation processes and human activities, notably past aggregate extraction from the nearshore sand bank which acted hitherto as both a dissipater of incident storm wave energy and as a coastal sand source. The aim of this paper to contribute to the understanding of these long-term changes and investigate the mechanisms of this mildly embayed coast evolution. To this end, 10-years of topographic profile data throughout the bay were analysed and confronted with offshore wave data. This analysis complements a previous analytical effort that determined gross rates of annual shoreline retreat by time slices of several decades from the careful interpretation of long series of ortho-rectified aerial photographs. The overall data suggest chronic sand bleeding from the western sector of the beach and longshore transport to the east, within a framework of what appears to be an ongoing beach rotation process within a dominant longshore sediment transport cell between the headland of Cape Gris Nez and the bold chalk cliffs of Cape Blanc Nez. Retreat of the beach-dune barrier in the western sector of Wissant Bay poses a threat in the coming years as there is a likelihood of storm breaching of the narrow dune barrier. Face to this critical situation, a proper management strategy involving a good

  5. Tectonic uplift and climate controlling erosion along the Southern Himalayan Front

    NASA Astrophysics Data System (ADS)

    Bookhagen, B.; Thiede, R.

    2001-12-01

    The spatial and temporal evolution of rock uplift in active orogens provide valuable insights into the relations between surface and tectonic processes, and topography. A prime example is the humid western and central part of the southern Himalayan mountain front, where rainfall is high and evenly distributed. In the orographic rain shadow north of the Shillong Plateau (25N, 91E) located 250 km south of the eastern mountain front, annual rainfall decreases to 70% from west to east (i.e. 6m/a vs. < 1.7m/a). Other areas with low precipitation occur along the entire southern Himalayan front at elevations over 3000m, where moisture has fallen as rain at lower elevations. Along the entire southern Himalayan front, lithology, tectonic style and neotectonic activity do not vary strongly along strike. Therefore, substantial along-strike variations of topography possibly reflect local differences in uplift and climate-controlled erosion. Digital elevation models were used in an analysis of topography and channel gradients. Precipitation data are based on calibrated passive microwave data (SSMI) with a spatial resolution of 12.5 km2; DEMs along the Southern Himalayan Front were generated using the GTOPO30 data set. High-resolution topographic data (1:25,000, 1:50,000 and 1:100,000 maps) were used to characterize geomorphology in several areas. The N-S trending Sutlej Valley (32N, 78E) is drained by the antecedent Sutlej River which cuts through the Tethyan Himalaya, High and Lower Himalayan Crystalline, and the Lesser Himalaya. The Arun (27N, 87E) and Manas valleys (27.5N, 91.5E) have a similar lithology and geologic structures, but the latter lies within the orographic rain shadow of the Shillong Plateau. Significantly diverse topographic swath profiles that show steep slopes in high precipitation areas while gentler slopes dominate in dry areas. All sectors with evenly distributed high orographic precipitation and runoff to elevations of approximately 3000m have smooth

  6. Guidelines for Vegetative Erosion Control on Wave-Impacted Coastal Dredged Material Sites

    DTIC Science & Technology

    1990-09-01

    severity is shore geometry (the shape of the shoreline). Common sense would dictate that sites located in narrow coves may be effectively sheltered from...3 Background.................................................... ....... 3 Role of Marshes in Shore ...Stability................................... 4 Impact of Mars-res on Shore Erosion................................... 6 PARI II: SHORELINE REVEGETATION

  7. Watershed management for erosion and sedimentation control Case Study: Goodwin Creek, Panola County, MS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Goodwin Creek watershed is located within the loessal hills of northern Mississippi, a region of high erosion risk and elevated watershed sediment yields. This manuscript combines a regional history of land management and conservation issues from the time of European settlement to present with a...

  8. Alginate controls heartburn in patients with erosive and nonerosive reflux disease

    PubMed Central

    Savarino, Edoardo; de Bortoli, Nicola; Zentilin, Patrizia; Martinucci, Irene; Bruzzone, Luca; Furnari, Manuele; Marchi, Santino; Savarino, Vincenzo

    2012-01-01

    AIM: To evaluate the effect of a novel alginate-based compound, Faringel, in modifying reflux characteristics and controlling symptoms. METHODS: In this prospective, open-label study, 40 patients reporting heartburn and regurgitation with proven reflux disease (i.e., positive impedance-pH test/evidence of erosive esophagitis at upper endoscopy) underwent 2 h impedance-pH testing after eating a refluxogenic meal. They were studied for 1 h under basal conditions and 1 h after taking 10 mL Faringel. In both sessions, measurements were obtained in right lateral and supine decubitus positions. Patients also completed a validated questionnaire consisting of a 2-item 5-point (0-4) Likert scale and a 10-cm visual analogue scale (VAS) in order to evaluate the efficacy of Faringel in symptom relief. Tolerability of the treatment was assessed using a 6-point Likert scale ranging from very good (1) to very poor (6). RESULTS: Faringel decreased significantly (P < 0.001), in both the right lateral and supine decubitus positions, esophageal acid exposure time [median 10 (25th-75th percentil 6-16) vs 5.8 (4-10) and 16 (11-19) vs 7.5 (5-11), respectively] and acid refluxes [5 (3-8) vs 1 (1-1) and 6 (4-8) vs 2 (1-2), respectively], but increased significantly (P < 0.01) the number of nonacid reflux events compared with baseline [2 (1-3) vs 3 (2-5) and 3 (2-4) vs 6 (3-8), respectively]. Percentage of proximal migration decreased in both decubitus positions (60% vs 32% and 64% vs 35%, respectively; P < 0.001). Faringel was significantly effective in controlling heartburn, based on both the Likert scale [3.1 (range 1-4) vs 0.9 (0-2); P < 0.001] and VAS score [7.1 (3-9.8) vs 2 (0.1-4.8); P < 0.001], but it had less success against regurgitation, based on both the Likert scale [2.6 (1-4) vs 2.2 (1-4); P = not significant (NS)] and VAS score [5.6 (2-9.6) vs 3.9 (1-8.8); P = NS]. Overall, the tolerability of Faringel was very good 5 (2-6), with only two patients reporting modest adverse

  9. Controlling Gully Erosion: An Analysis of Land Reclamation Processes and Challenges in Chambal Badlands, India

    NASA Astrophysics Data System (ADS)

    Pani, Padmini

    2016-04-01

    Gully erosion is among the significant environmental problems in the Central Indian states. The Chambal badlands, spread over an area of around 4000 sq. kms is among the worst affected regions in terms of land degradation. The enormity of the Chambal ravines, which achieve depths of more than 60 metres, points to the significance of the geological explanation, suggesting that neotectonics may have paved the way for ravine erosion, but it is most definitely exacerbated by anthropogenic activities. Although, there is field evidence that ephemeral gully erosion is responsible for significant soil losses, little is known about the contributing factors. The region also faces significant developmental challenges and the inaccessibility and low productivity of the area contributes to its continued underdevelopment. This study uses a combination of geo-spatial techniques and physical and socio-economic field survey to evaluate the responses to gully erosion and its implications. This paper attempts to study (a) extent and severity of gully erosion process in the Chambal badlands; (b) an evaluation of reclamation measures undertaken by various agencies, including the affected people; (c) to examine the sustainability implications of land reclamation measures. The extent, pattern and inter-temporal changes of gully erosion have been examined through various mapping techniques and field survey. The land reclamation have been mapped using satellite images and ground truth verification. The various kinds of land reclamation measures that have been undertaken on the ground and their sustainability implications have been investigated through survey of affected households in selected villages. The results show that in response to the severe loss of agricultural land because of gully head encroachment in the agricultural field and decline in land productivity, farmers have undertaken various land reclamation measures, including mechanised land levelling. The land levelling

  10. The role of forest stand density in controlling soil erosion: implications to sediment-related disasters in Japan.

    PubMed

    Razafindrabe, Bam H N; He, Bin; Inoue, Shoji; Ezaki, Tsugio; Shaw, Rajib

    2010-01-01

    The role of forest stand density in controlling soil erosion was investigated in Ehime Prefecture, Japan. The main objective was to compare soil erosion under different forest conditions including forest type, species composition, and stand density as influenced by thinning operations. Relative yield index (Ry) was used as an indicator of stand density to reflect the degree of management operations in the watershed. Eleven treatments were established based on the above forest conditions. Soil loss was collected in each of the 11 treatments after each rainfall event for a period of 1 year. The paper presents summary data on soil loss as affected by forest conditions and rainfall patterns. Findings showed that an appropriate forest management operation, which can be insured by stand density control, is needed to reduce soil loss. The present study plays an important role in clarifying technical processes related to soil erosion, while it helps linking these elements to current Japanese forestry issues and bringing new inputs to reducing sediment-related disasters in Japan.

  11. Nourishment of perched sand dunes and the issue of erosion control in the Great Lakes

    NASA Astrophysics Data System (ADS)

    Marsh, William M.

    1990-09-01

    Although limited in coverage, perched sand dunes situated on high coastal bluffs are considered the most prized of Great Lakes dunes. Grand Sable Dunes on Lake Superior and Sleeping Bear Dunes on Lake Michigan are featured attractions of national lakeshores under National Park Service management. The source of sand for perched dunes is the high bluff along their lakeward edge. As onshore wind crosses the bluff, flow is accelerated upslope, resulting in greatly elevated levels of wind stress over the slope brow. On barren, sandy bluffs, wind erosion is concentrated in the brow zone, and for the Grand Sable Bluff, it averaged 1 m3/yr per linear meter along the highest sections for the period 1973 1983. This mechanism accounts for about 6,500 m3 of sand nourishment to the dunefield annually and clearly has been the predominant mechanism for the long-term development of the dunefield. However, wind erosion and dune nourishment are possible only where the bluff is denuded of plant cover by mass movements and related processes induced by wave erosion. In the Great Lakes, wave erosion and bluff retreat vary with lake levels; the nourishment of perched dunes is favored by high levels. Lake levels have been relatively high for the past 50 years, and shore erosion has become a major environmental issue leading property owners and politicians to support lake-level regulation. Trimming high water levels could reduce geomorphic activity on high bluffs and affect dune nourishment rates. Locally, nourishment also may be influenced by sediment accumulation associated with harbor protection facilities and by planting programs aimed at stabilizing dunes.

  12. The Indonesian treponematoses control project.

    PubMed

    SOETOPO, M; WASITO, R; SOEDARSONO, H; TJOKRODIPO, D

    1956-01-01

    Yaws control in Indonesia is based on use of the trained polyclinic nurse and his assistant, the "djuru-patek"; the polyclinics existed before the control began and each serves one subdistrict with a population of about 30 000. The campaign is thus part of the established health services from the start and consolidation presents few difficulties of integration. Surveys and resurveys are held by calling together the village population for examination and later for treatment. The maximum dose (1.2 million units of PAM) is given to active cases only. At resurveys most active cases are found in those who had latent or incubating yaws when seen earlier.It is pointed out that prevalence ratios of active cases to seroreactors of 1: 3-4 are probably due to previous treatment having been given; in previously untreated areas, a ratio of 1: 2 is more usual.In the consolidation stage, surveillance is maintained in polyclinics, villages and schools and the fullest co-operation of the population is sought, as it is at all stages of the campaign.

  13. Holocene activity of an alpine debris-flow catchment: does climate control erosion rate variability?

    NASA Astrophysics Data System (ADS)

    Savi, S.; Norton, K. P.; Brardinoni, F.; Akçar, N.; Kubik, P.; Picotti, V.; Schlunegger, F.

    2012-12-01

    The Zielbach catchment is located in the central-eastern Italian Alps. It covers an area of ca. 40 km2 and is characterized by fluvial sediment transport along the main drainage basin, and by the supply of sediment through debris flows, derived from a ca. 10 km2 tributary catchment. A debris-flow database demonstrates that nowadays this latter tributary dominates the sediment budget of the entire Zielbach. In this study, we analyze modern and paleo-erosion rates of the catchment through the application of the cosmogenic nuclides technique. For modern erosion rate, samples of river-born sand were taken from the main river and tributaries along the entire drainage system, while paleo-erosion rates are calculated thanks to cores' samples, which were collected on the alluvial fan and which were likewise dated based on 14C measurements of organic matter. Results obtained from the modern drainage system reveal the spatial erosion rate variability that characterizes the catchment nowadays (values ranging from 2.6 to 0.15 mm/yr). This spatial pattern is characterized by a generally increasing trend of 10Be values where hillslope contributions predominate and by a decreasing concentration trend where sediment has been supplied by debris flows. Results obtained from the cores allow the reconstruction of the Zielbach Holocene evolution and the assignment of the climate role on the temporal erosion rate variability (values ranging between 21 and 0.43 mm/yr). 14C concentrations of organic material collected from the core material indicate a lowermost age of 10'000 yr at ca. 35 m depth. The sedimentary fabric of the deposits indicates that the fan is built up by alternation of alluvial and debris-flow deposits, where the latter ones dominate in volumes. The stratigraphic architecture also infers that alluvial deposits correspond to periods of low activity of the debris-flow catchment. Most important, however, paleo-erosion rates indicate a decreasing trend for the debris

  14. Watershed-scale evaluation of the Water Erosion Prediction Project (WEPP) model in the Lake Tahoe basin

    NASA Astrophysics Data System (ADS)

    Brooks, Erin S.; Dobre, Mariana; Elliot, William J.; Wu, Joan Q.; Boll, Jan

    2016-02-01

    Forest managers need methods to evaluate the impacts of management at the watershed scale. The Water Erosion Prediction Project (WEPP) has the ability to model disturbed forested hillslopes, but has difficulty addressing some of the critical processes that are important at a watershed scale, including baseflow and water yield. In order to apply WEPP to forested watersheds, we developed and assessed new approaches for simulating streamflow and sediment transport from large watersheds using WEPP. We created specific algorithms to spatially distribute soil, climate, and management input files for all the subwatersheds within the basin. The model enhancements were tested on five geologically and climatically diverse watersheds in the Lake Tahoe basin, USA. The model was run with minimal calibration to assess WEPP's ability as a physically-based model to predict streamflow and sediment delivery. The performance of the model was examined against 17 years of observed snow water equivalent depth, streamflow, and sediment load data. Only region-wide baseflow recession parameters related to the geology of the basin were calibrated with observed streamflow data. Close agreement between simulated and observed snow water equivalent, streamflow, and the distribution of fine (<20 μm) and coarse (>20 μm) sediments was achieved at each of the major watersheds located in the high-precipitation regions of the basin. Sediment load was adequately simulated in the drier watersheds; however, annual streamflow was overestimated. With the exception of the drier eastern region, the model demonstrated no loss in accuracy when applied without calibration to multiple watersheds across Lake Tahoe basin demonstrating the utility of the model as a management tool in gauged and ungauged basins.

  15. "Back fall" dust controls seasonal erosion and composition measurements of 67P

    NASA Astrophysics Data System (ADS)

    Keller, Horst Uwe; Hviid, Stubbe F.; Mottola, Stefano; Agarwal, Jessica; OSIRIS

    2016-10-01

    Seasonal effects of 67P's activity are very pronounced due to the strong insolation during southern summer when the comet is near its perihelion. About ¾ of the overall gas and dust production are released from the southern hemisphere when large parts of the surface near the north pole are in polar night (Keller et al. 2015). This leads to a dichotomy of the hemispheres. The southern regions show rough consolidated material whereas the northern plain surfaces are covered by what looks like dust (El Maary et al 2015). Recent close up observations of the northern territories show a granularity near the resolution limit of the images. This is comparable to the sizes of particles (10-20 cm) seen to cross the coma at velocities comparable to or below the escape speed from the nucleus around perihelion. These large particles are deprived from super volatiles but maintain their water ice content. A major part will cover the northern hemisphere as "back fall" over the aphelion passage and will lead to water controlled activity from the northern hemisphere during the next cometary approach. New dune-like features (Thomas et al. 2015) have been recently observed in the gravitational low Hapi region. Philae ROLIS images show wind tails and moats around obstacles, all oriented in a south-north direction, that are well modelled by abrasion by impinging back fall from the south (Mottola et al. 2015). Consequently activity from the northern hemisphere during the early Rosetta mission revealed mainly water molecules (Fougere et al. to be submitted) originating from back fall and not from the original consolidated surface, that was widely isolated by the cover of back fall. Hence more volatile compounds such as CO2 and CO are not reached by insolation. Composition measurements of the northern hemisphere are strongly influenced by the back fall cover and do not reflect the original composition of the nucleus. A further consequence is that erosion of the nucleus of 67P takes place

  16. Changes in forcing factors affecting coastal and shallow water erosion in the future Arctic climate change projections.

    NASA Astrophysics Data System (ADS)

    Dobrynin, Mikhail; Razumov, Sergey; Brovkin, Victor; Ilyina, Tatiana; Grigoriev, Mikhail

    2016-04-01

    Driving factors of seabed and coastal erosion in the Arctic can be classified as thermal and mechanical. Thermal factors such as air and ocean temperatures affect the seabed and coastal ground temperatures. Mechanical factors such as ocean currents and surface gravity waves contribute to the seabed and costal erosion due to shear stress. Due to polar amplification, the Arctic experiences strong increase in air and water temperature, sea-ice loss and changes in the ocean and atmospheric circulation, temperature and wind distribution. These climatic changes lead to changes in factors driving seabed and coastal erosion, which is expected to accelerate in the shallow Arctic regions such as the Laptev sea and East Siberian sea. In these regions, the coastal line to a large extent consists of frozen rocks, sediments and organic soils including ground ice. The increase of erosion rate of the coastal line will increase the release of organic and inorganic matter from thawed permafrost. Dynamics of thermal and mechanical drivers of seabed and coastal erosion in the present and future climate change (RCP8.5 scenario) simulated by the CMIP5 version of the MPI Earth system model and wave model WAM will be presented. Special attention will be given to changes in the air temperature, wind dynamics and development of new waves system in the ``ice-free'' Arctic and its role in the seabed and coastal erosion.

  17. Monsoonal vs. glacial control on erosion and sediment storage in the Himalayan rain shadow, Zanskar River, northwest India

    NASA Astrophysics Data System (ADS)

    Jonell, Tara; Clift, Peter; Carter, Andrew; Böning, Philipp; Wittmann, Hella

    2016-04-01

    Summer monsoon precipitation strongly controls erosion and sediment storage in the frontal Himalaya but the relationship between monsoonal variability and erosion is less well-constrained beyond the High Himalayan topographic divide in the rain shadow. Here we establish a Quaternary erosional history for a rain shadow tributary of the upper Indus River system, the Zanskar River, by applying several sediment provenance techniques to modern and dated terrace river sediments. We evaluate if there are temporal links between sediment storage and moisture supply to the rain shadow and if regions like the Zanskar River basin play a significant role in controlling total sediment flux to the Indus River. We compile bulk sediment petrography and Sr and Nd isotope geochemistry, detrital U-Pb zircon and apatite fission track dating with in-situ 10Be cosmogenic radionuclide techniques to identify patterns of erosion and sediment production across Zanskar. Bulk petrography, Sr and Nd isotope geochemistry, and U-Pb detrital zircon spectra of modern and older terrace sediments indicate high rates of erosion along the Greater Himalaya in the Zanskar River basin. We find that the wettest and most glaciated subcatchment dominates the bulk sediment provenance signal, with only moderate input from other tributaries, and that other basin parameters cannot explain our observations. Catchment-averaged in-situ 10Be cosmogenic nuclide concentrations of modern sediments indicate erosion rates up to ˜1.2 mm y-1 but show strong dilution attributed to glacial sediment recycling into the modern river, suggesting rates nearer 0.4-0.6 mm•y-1. These rates are consistent with longer-term rates of incision (0.3-0.7 mm•y-1) calculated from detrital apatite fission track ages, and incision rates inferred from Late Glacial and Holocene terraces near the Zanskar-Indus confluence. Our findings suggest that sediment production in glaciated Himalayan rain shadow environments like Zanskar is largely

  18. Erosion Control and Recultivation Measures at a Headrace Channel of a Hydroelectric Power Plant using Different Combined Soil Bioengineering Techniques

    NASA Astrophysics Data System (ADS)

    Obriejetan, M.; Florineth, F.; Rauch, H. P.

    2012-04-01

    As a consequence of land use change resulting in an increased number of slope protection constructions and with respect to effects associated with climate change like extremes in temperatures and temperature variations or increased frequency of heavy precipitation, adaptation strategies for sustainable erosion protection systems are needed which meet ecological compatibility and economical requirements. Therefore a wide range of different technical solutions respectively geotextiles and geotextile-related products (blankets, nettings, grids etc.) are available on the market differing considerably in function, material, durability and pricing. Manufacturers usually provide product-specific information pertaining to application field, functional range or (technical) installation features whereas vegetational aspects are frequently neglected while vegetation can contribute substantially to increased near-surface erosion protection respectively slope stability. Though, the success of sustainable erosion control is directly dependent on several vegetational aspects. Adequate development of a functional vegetation layer in combination with geotextiles is closely associated to application aspects such as seeding technique, sowing date and intensity, seed-soil contact or maintenance measures as well as to qualitative aspects like seed quality, germination rates, area of origin, production method or certification. As a general guideline, erosion control within an initial phase is directly related to restoration techniques whereas vegetation specifics with regard to species richness or species composition play a key role in medium to long-term development and slope protection. In this context one of the fundamental objectives of our study is the identification and subsequently the determination of the main interaction processes between technical and biological components of combined slope protection systems. The influence of different geotextile characteristics on specific

  19. Role of mechanical erosion in controlling the effusion rate of basaltic eruptions

    NASA Astrophysics Data System (ADS)

    Piombo, Antonello; Tallarico, Andrea; Dragoni, Michele

    2016-09-01

    In many basaltic eruptions, observations show that the effusion rate of magma has a typical dependence on time: the effusion rate curves show first a period of increasing and later a decreasing phase by a maximum value. We present a model to explain this behavior by the emptying of a magma reservoir through a vertical cylindrical conduit with elliptical cross section, coupled with the its widening due to mechanical erosion, produced by the magma flow. The model can reproduce the observed dependence on time of effusion rate in basaltic eruptions. Eruption duration and the maximum value of effusion rate depend on the size of magma chamber, on lava viscosity and strongly on erosion rate per unit traction.

  20. The role of the Asian monsoon in controlling erosion, weathering and the flux of sediment to the ocean

    NASA Astrophysics Data System (ADS)

    Clift, Peter

    2013-04-01

    The summer monsoon dominates the rainfall of South and SE Asia and is anticipated to be the primary control on continental erosion and weathering during the Quaternary when tectonic processes do not vary significantly except at local scales. Periods of strong monsoon generally correlate with interglacial, sealevel highstands. Such periods are recognized as times of enhanced reworking of stored sediment from flood plains or fluvial terraces within mountains, resulting in fast sedimentation being recorded in delta systems. Rising sealevels usually prevent large sediment volumes being reworked on to the continental slope, but what is deposited during periods of intensifying monsoon is more altered than sediment deposited prior to that time. In the South China Sea sedimentation on to the slope is largely driven by reworking of older weathered materials from the shelf, rather than directly from productive sources, such as Taiwan. Enhanced reworking is only curtailed by rising sealevels drowning the continental slope and shifting erosion further back onshore. While hotter, wetter conditions favor faster chemical weathering, the more weathered nature of sediment deposited at that time represents reworking of older stored sediment, not an immediate response to changing environmental conditions. New OSL dates from the Indus Basin support the idea of valley filling during time of strengthening monsoon followed by subsequent incision and reworking. Landslide damming caused by heavy summer rains may be a dominant process in this sediment buffering process, which results in lag times between initial erosion and delivery to the ocean on the order of 5-15 k.y. for finer grained sediment and potentially longer for dense detrital phases, such as zircon. Recognizing these lags is important when correlating marine erosion records with terrestrial climate records derived from lakes or caves if we are to understand the response of landscape to climate change.

  1. Erosion Control Methods for Army Training Land Rehabilitation: Survey of Current Technology

    DTIC Science & Technology

    1988-05-01

    be filled and shaped in order to produce a uniformly smoothed surface that is free of blockages which could produce overfalls and increased erosion...for More Permanent Protection from Runoff Structures and Systems for Runoff Management Grade Stabilization Structures Energy Dissipation Structures for...Spillway 50 27 Flume Designed With Energy Dissipators 50 28 Concrete Chute 51 29 Stilling Well 53 30 Stilling Basins 53 31 Straw Bales Used at Storm Drain

  2. Maintenance and Control of Erosion and Sediment Along Secondary Roads and Tertiary Trails.

    DTIC Science & Technology

    1997-07-01

    Clays are and base course materials, in all but the free - the worst materials to use. draining, coarse-grained materials, is directly linked to the...less desirable it pH Tests. pH stands for potential hydrogen and is for subgrade, subbase, or base material. refers to the amount of free hydrogen in...to accelerated erosion in steeply sloping ered coarse-grained materials. Typically the best ditches. subgrade and base materials are those free -drain

  3. [Influence of three types of riparian vegetation on fluvial erosion control in Pantanos de Centla, Mexico].

    PubMed

    Sepúlveda-Lozada, Alejandra; Geissen, Violette; Ochoa-Gaona, Susana; Jarquín-Sánchez, Aarón; de la Cruz, Simón Hernández; Capetillo, Edward; Zamora-Cornelio, Luis Felipe

    2009-12-01

    Wetlands constitute very important ecological areas. The aim of this study was to quantify the soil losses due to fluvial erosion from 2006 to 2008 in two riverbanks under three types of vegetal coverage dominated by Haematoxylum campechianum, Dalbergia brownei and Brachiaria mutica, in the Pantanos de Centla Biosphere Reserve, SE Mexico. The relationship between the texture, organic matter and pH of soils and soil losses was evaluated. We used erosion sticks to estimate soil losses in 18 plots (three plots per type, three vegetation types, two riverbanks). Soil loss decreased in this order: H. campechianum>B. mutica>D. brownei indicating that D. brownei scrubland has the most potential to retain soil. The higher erosive impact within H. campechianum sites can be related with the low density of these trees in the study areas, as well as the lack of association with other types of vegetation that could reinforce the rooting of the soil profile. Furthermore, soil losses in H. campechianum sites were dependent on soil texture. The soils under this type of vegetal coverage were mainly sandy, which are more vulnerable to the erosive action in comparison with fine textured soils or soils with higher clay content, like the ones found in D. brownei and B. mutica sites. Soil losses of 100 % in the second year (B. mutica plots) can be attributed to the distribution of roots in the upper soil layer and also to livestock management along riverbanks. This study recognizes the importance of D. brownei scrublands in riverbank soil retention. Nevertheless it is necessary to consider the role of an entire vegetal community in future research.

  4. An investigation of bergmounds as analogs to erosion control factors on protective barriers

    SciTech Connect

    Chamness, M.A.

    1993-09-01

    Included in several of the final disposal strategies proposed in the Interim Hanford Waste Management Plan (DOE-RL 1986a) is design of a protective barrier to isolate the underlying waste sites from the environment. The conceptual protective barrier design requires a fine-grained sediment to retain precipitation near the top of the barrier where evapotranspiration can recycle the moisture back into the atmosphere. The design incorporates gravel into the topsoil as one way to reduce its erosion. Information is needed to determine the optimal ratio of gravel to topsoil needed to reduce erosion without significantly reducing evapotranspiration, and its effect on erosion. Bergmounds are mounds with a gravelly surface that were formed about 13,000 years ago and represent natural analogs to the topsoil portion of the protective barrier. The primary goal of this study was to identify characteristics of bergmounds and the effects of these characteristics, especially the gravelly surface, on the amount and rate of erosion. A secondary goal was to apply a technique normally used to estimate vegetation cover to measure percent gravel cover, and to compare this technique with particle size distribution based on weight percent. Four bergmounds were investigated for this study, two in a windy site and two in a more sheltered site. Each bergmound was sampled in eight locations. Two methods were used to estimate the amount of surface gravel: the ocular point-intercept method which estimates the percent gravel cover, and sieved samples of the surface sediments which measure the percent gravel by weight. Holes were dug at each bergmound`s eight sampling sites to examine and sample the subsurface sediments.

  5. Effect of chemical and mechanical weed control on cassava yield, soil quality and erosion under cassava cropping system

    NASA Astrophysics Data System (ADS)

    Islami, Titiek; Wisnubroto, Erwin; Utomo, Wani

    2016-04-01

    Three years field experiments were conducted to study the effect of chemical and mechanical weed control on soil quality and erosion under cassava cropping system. The experiment were conducted at University Brawijaya field experimental station, Jatikerto, Malang, Indonesia. The experiments were carried out from 2011 - 2014. The treatments consist of three cropping system (cassava mono culture; cassava + maize intercropping and cassava + peanut intercropping), and two weed control method (chemical and mechanical methods). The experimental result showed that the yield of cassava first year and second year did not influenced by weed control method and cropping system. However, the third year yield of cassava was influence by weed control method and cropping system. The cassava yield planted in cassava + maize intercropping system with chemical weed control methods was only 24 t/ha, which lower compared to other treatments, even with that of the same cropping system used mechanical weed control. The highest cassava yield in third year was obtained by cassava + peanuts cropping system with mechanical weed control method. After three years experiment, the soil of cassava monoculture system with chemical weed control method possessed the lowest soil organic matter, and soil aggregate stability. During three years of cropping soil erosion in chemical weed control method, especially on cassava monoculture, was higher compared to mechanical weed control method. The soil loss from chemical control method were 40 t/ha, 44 t/ha and 54 t/ha for the first, second and third year crop. The soil loss from mechanical weed control method for the same years was: 36 t/ha, 36 t/ha and 38 t/ha. Key words: herbicide, intercropping, soil organic matter, aggregate stability.

  6. Radial Erosion

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The ejecta surrounding the crater (off image to the left) in this image has undergone significant erosion by the wind. The wind has stripped the surface features from the ejecta and has started to winnow away the ejecta blanket. Near the margin of the ejecta the wind is eroding along a radial pattern -- taking advantage of radial emplacement. Note the steep margin of the ejecta blanket. Most, if not all, of the fine ejecta material has been removed and the wind in now working on the more massive continuous ejecta blanket.

    Image information: VIS instrument. Latitude 12.5, Longitude 197.4 East (162.6 West). 37 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  7. NASA Project Planning and Control Handbook

    NASA Technical Reports Server (NTRS)

    Moreland, Robert; Claunch, Cathy L.

    2016-01-01

    This handbook provides an overview of the fundamental principles and explains the functions and products that go into project planning and control. The 2010 Interim Results of the NASA Program Planning and Control (PPC) Study identified seven categories of activities for PPC, and those provide the basis for the seven functions described in this handbook. This handbook maps out the interfaces and interactions between PPC functions, as well as their external interfaces. This integration of information and products within and between functions is necessary to form the whole picture of how a project is progressing. The handbook descriptions are meant to facilitate consistent, common, and comprehensive approaches for providing valued analysis, assessment, and evaluation focused on the project level at NASA. The handbook also describes activities in terms of function rather than the job title or the specific person or organization responsible for the activity, which could differ by Center or size of a project. This handbook is primarily guidance for project planning and control: however, the same principles apply to programs and generally apply to institutional planning and control.

  8. Investigation of wind erosion process for estimation, prevention, and control of DSS in Yazd-Ardakan plain.

    PubMed

    Ekhtesasi, M R; Sepehr, A

    2009-12-01

    accidents on the main roads of Yazd-Ardakan and can cancel the airplane flights in the stormy days. At present, it is estimated that wind erosion causes more than $6.8 million damages to socioeconomic resources in Yazd plain each year. This paper describes the pattern of occurrence of wind erosion and major contributing factors, summarizes measured rates of wind erosion, outlines the techniques used to mitigate wind erosion hazard, and suggests research priorities. Also, damages of DSS have been estimated and methods for prevention and control are suggested.

  9. Biocompatible photocrosslinked poly(ester anhydride) based on functionalized poly(epsilon-caprolactone) prepolymer shows surface erosion controlled drug release in vitro and in vivo.

    PubMed

    Mönkäre, J; Hakala, R A; Vlasova, M A; Huotari, A; Kilpeläinen, M; Kiviniemi, A; Meretoja, V; Herzig, K H; Korhonen, H; Seppälä, J V; Järvinen, K

    2010-09-15

    Star-shaped poly(epsilon-caprolactone) oligomers functionalized with succinic anhydride were used as prepolymers to prepare photocrosslinked poly(ester anhydride) to evaluate their in vivo drug delivery functionality and biocompatibility. Thus, in this work, erosion, drug release and safety of the photocrosslinked poly(ester anhydride) were examined in vitro and in vivo. A small water-soluble drug, propranolol HCl (M(w) 296 g/mol, solubility 50 mg/ml), was used as the model drug in an evaluation of the erosion controlled release. Drug-free and drug-loaded (10-60% w/w) poly(ester anhydride) discoids eroded in vitro (pH 7.4 buffer, +37 degrees C) linearly within 24-48 h. A strong correlation between the polymer erosion and the linear drug release in vitro was observed, indicating that the release had been controlled by the erosion of the polymer. Similarly, in vivo studies (s.c. implantation of discoids in rats) indicated that surface erosion controlled drug release from the discoids (drug loading 40% w/w). Oligomers did not decrease cell viability in vitro and the implanted discoids (s.c., rats) did not evoke any cytokine activity in vivo. In summary, surface erosion controlled drug release and the safety of photocrosslinked poly(ester anhydride) were demonstrated in this study.

  10. Erosion: Wind

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind erosion refers to the detachment, transport and deposition of sediment by wind. It is a dynamic, physical process where loose, dry, bare soils are transported by strong winds. Wind erosion is a soil degrading process that affects over 500 million ha of land worldwide and creates between 500 an...

  11. Irrigation: Erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigation is essential for global food production. However, irrigation erosion can limit the ability of irrigation systems to reliably produce food and fiber in the future. The factors affecting soil erosion from irrigation are the same as rainfall—water detaches and transports sediment. However, t...

  12. Ecosystem-controlled Erosion in a Loess-mantled Landscape in Eastern Washington

    NASA Astrophysics Data System (ADS)

    Walther, S. C.; Roering, J. J.; Almond, P. C.; Hughes, M.

    2005-12-01

    Vegetation varies with climate so it is important to constrain how different vegetation types affect sediment transport. In forested landscapes, tree throw plays a large role in increased sediment transport relative to shrub and grassland. In this study, we quantify soil transport rates in a coniferous forest using hillslope profiles and tephra abundance. The loess-mantled hillslopes of Robinette Mountain in the Blue Mountains, confining the southeastern edge of the Columbia Plateau in southeast Washington State, USA, have been forested since the Holocene transition. Approximately 6800 years ago, the eruption of Mt. Mazama blanketed the region with tephra. Near the crest of hillslopes of different degrees of convexity, we identified and sampled soils for cryptotephra analysis. The depth of the tephra abundance spike is used as a proxy for erosion/exhumation rate since deposition. The slope dependent sediment transport model suggests that the change in elevation with time (or landscape lowering rate) is proportional to the hillslope curvature, with the constant of proportionality referred to as K (m2 yr-1). Therefore, we surveyed slope morphology for comparison with erosion rate at each site. K generally depends on processes such as soil creep, rain splash, variations in soil moisture (wet/dry) and temperature (freeze/thaw), tree throw, and faunal burrowing/biogenic activity. By estimating the value of K we can relate sediment transport to dominant processes in our forested landscape, such as frequency of tree turnover or faunal burrowing, and determine the spatial variability of erosion rates and sediment delivery using topographic hillslope surveys.

  13. A PERMEABLE ACTIVE AMENDMENT CONCRETE (PAAC) FOR CONTAMINANT REMEDIATION AND EROSION CONTROL

    SciTech Connect

    Knox, A.; Paller, M.; Dixon, K.

    2012-06-29

    The final project report for SEED SERDP ER - 2134 describes the development of permeable active amendment concrete (PAAC), which was evaluated through four tasks: 1) development of PAAC; 2) assessment of PAAC for contaminant removal; 3) evaluation of promising PAAC formulations for potential environmental impacts; and 4) assessment of the hydraulic, physical, and structural properties of PAAC. Conventional permeable concrete (often referred to as pervious concrete) is concrete with high porosity as a result of an extensive and interconnected void content. It is made from carefully controlled amounts of water and cementitious materials used to create a paste that forms a coating around aggregate particles. The mixture has a substantial void content (e.g., 15% - 25%) that results in a highly permeable structure that drains quickly. In PAAC, the aggregate material is partly replaced by chemically-active amendments that precipitate or adsorb contaminants in water that flows through the concrete interstices. PAAC combines the relatively high structural strength, ample void space, and water permeability of pervious concrete with the contaminant sequestration ability of chemically-active amendments to produce a new material with superior durability and ability to control contaminant mobility. The high surface area provided by the concrete interstices in PAAC provides significant opportunity for contaminants to react with the amendments incorporated into the concrete matrix. PAAC has the potential to immobilize a large variety of organic and inorganic contaminants by incorporating different active sequestering agents including phosphate materials (rock phosphate), organoclays, zeolite, and lime individually or in combinations.

  14. Polyanhydride degradation and erosion.

    PubMed

    Göpferich, A; Tessmar, J

    2002-10-16

    It was the intention of this paper to give a survey on the degradation and erosion of polyanhydrides. Due to the multitude of polymers that have been synthesized in this class of material in recent years, it was not possible to discuss all polyanhydrides that have gained in significance based on their application. It was rather the intention to provide a broad picture on polyanhydride degradation and erosion based on the knowledge that we have from those polymers that have been intensively investigated. To reach this goal this review contains several sections. First, the foundation for an understanding of the nomenclature are laid by defining degradation and erosion which was deemed necessary because many different definitions exist in the current literature. Next, the properties of major classes of anhydrides are reviewed and the impact of geometry on degradation and erosion is discussed. A complicated issue is the control of drug release from degradable polymers. Therefore, the aspect of erosion-controlled release and drug stability inside polyanhydrides are discussed. Towards the end of the paper models are briefly reviewed that describe the erosion of polyanhydrides. Empirical models as well as Monte-Carlo-based approaches are described. Finally it is outlined how theoretical models can help to answer the question why polyanhydrides are surface eroding. A look at the microstructure and the results from these models lead to the conclusion that polyanhydrides are surface eroding due to their fast degradation. However they switch to bulk erosion once the device dimensions drop below a critical limit.

  15. Effects of erosion control structures along a portion of the northern Chesapeake Bay shoreline

    USGS Publications Warehouse

    Zabawa, C.F.; Kerhin, R.T.; Bayley, S.

    1981-01-01

    A 6.500-meter reach of western Chesapeake Bay shoreline (lower Mayo Peninsula) lost about 1.1??106 cubic meters of sediment (equivalent to 170 cubic meters lost per meter of shoreline) between 1846 and 1932, when the first aerial photographs show the shoreline already substantially protected by a system of groins and intermittent bulkheading. These structures have eliminated the fastland as a source of erodable material, and have starved the supply of sand for littoral drift, thus limiting the extent of the beaches to the remaining groin fields. Volumes of sediment involved in these impacts are small in the overall sediment budget. Bulkheads produce no deficit in the budget since scouring of the beaches on their seaward sides makes up for the decreased erosion of protected fastland. Groins trap little of the potential littoral drift (computed to be about 104 cubic meters per meter of shoreline per year). The sand supply in the remaining beaches is nearly equivalent to the annual loss of sediment from the entire shoreline system due to the long-term rate of erosion of the shoreline and nearshore between 1846 and 1932. ?? 1981 Springer-Verlag New York Inc.

  16. Erosion control in orchards and vineyards by a new soil and cover crop management method

    NASA Astrophysics Data System (ADS)

    Hartl, Wilfried; Guettler, Hans; Auer, Karl; Erhart, Eva

    2016-04-01

    Cover crops are the basis for an erosion-free soil management in orchards and vineyards. The soil cover provided by the foliage and the intensive root formation counteract erosion. Cover crops provide the soil microfauna with fresh organic matter which improves soil structure and porosity. The water demand of cover crops, however, may pose problems for the water supply of the trees and vines in dry seasons. Therefore it is necessary to adjust the growth of the cover crops to the actual water conditions. In years with ample precipitation cover crops may be allowed lush vegetative growth till flowering and formation of seeds. In dry years, the growth of the cover crop must be restricted to stop the competition for water, sometimes even by cutting off the cover crop roots. The course of the weather is incalculable and rainfall may be very variable during the year, so it is sometimes necessary to adust the cover crop management several times a year. A new special equipment, which can perform all the tasks necessary for the flexible cover crop management has been developed together with the agricultural machinery manufacturers Bodenwerkstatt Ertl-Auer GmbH and Güttler GmbH. The GreenManager® device consists of three modules, namely a specific type of cultivator, a harrow and a prismatic roller with seeding equipment, which can be used separately or in combination. The GreenManager® can reduce cover crops by flattening the plants in the whole row middle, by bringing down the cover crops with the harrow, or by horizontally cutting the cover crop roots a few centimetres beneath the soil surface in the central part of the row middle or in the whole row middle. These measures reduce the water competition by cover crops without generating further losses of soil moisture through intensive soil cultivation. At the same time the risk of soil erosion is kept to a minimum, because the soil remains covered by dead plant biomass. In one passage the GreenManager® can direct

  17. Orbital controls on paleo erosion rates in the Western Escarpment of the Andes at 13° latitude

    NASA Astrophysics Data System (ADS)

    Schlunegger, Fritz; Bekaddour, Toufik; Delunel, Romain; Norton, Kevin; Akçar, Naki; Vogel, Hendrik

    2014-05-01

    The formation of fluvial terrace sequences in mountainous areas requires that two boundary conditions have to be fulfilled. First, hilllslope material available for erosion needs to be sufficiently thick and abundant. Second stripping off of this regolith cover has to occur fast and within a short time period. Contrariwise, if hillslope erosion operates at a pace concordant with the fluvial regime and in equilibrium to the prevailing climate, then no terrace sequence will form. Here, we present a 10Be-based sediment budget from the cut-and-fill terrace sequences in the Pisco valley, and particularly the Minchin terrace sequence deposited between 48-36 ka, to illustrate how the erosional regime and the precipitation pattern has changed in response to orbitally-driven climate cycles. We find that the Minchin period was characterized by an erosional pulse along the Pacific coast during which denudation rates reached values as high as 600 mm/ka (provided that the lateral valley flanks have been the major sediment source) for a relatively short time span lasting a few thousands of years. This contrasts to the younger orbitally-controlled pluvial periods and the modern situation when 10Be-based sediment budgets yield nearly zero erosion at the Pacific coast. We interpret these contrasts to indicated different erosional conditions between the modern and the Minchin time. First, the sediment budget infers a precipitation pattern that is similar to the modern climate ca. 1000 km farther north near the boundary between Peru and Ecuador, where highly erratic and extreme El Niño-related precipitation are associated with landsliding and flooding along the coast. Second, the formation of a thick terrace sequence requires the supply of sufficient material through erosion on the catchment's hillslopes. It is likely that a relatively thick regolith sequence had accumulated before the start of the Minchin period, because this erosional epoch was preceded by a >50 ka-long time span

  18. Assessment of Soil Moisture and Fixatives Performance in Controlling Wind Erosion of Contaminated Soil at the Hanford Site

    SciTech Connect

    Lagos, L.E.; Gudavalli, R.K.

    2008-07-01

    During the remediation of burial grounds at the US Department of Energy's (DOE's) Hanford Site in Washington State, the dispersion of contaminated soil particles and dust is an issue that is faced by site workers on a daily basis. This contamination issue is even more of a concern when one takes into account the semi-arid characteristics of the region where the site is located. To mitigate this problem, workers at the site use a variety of engineered methods to minimize the dispersion of contaminated soil and dust particles. Once such methods is the use of water and/or suppression agents (fixatives) that stabilizes the soil prior to soil excavation, segregation, and removal activities. A primary contributor to the dispersion of contaminated soil and dust is wind soil erosion. The erosion process occurs when the wind speed exceeds a certain threshold value (threshold shear velocity), which depends on a number of factors including wind force loading, particle size, surface soil moisture, and the geometry of the soil. Thus under these circumstances the mobility of contaminated soil and generation and dispersion of particulate matter are significantly influenced by these parameters. Wind tunnel experiments were conducted at the Florida International University's Applied Research Center (FIU-ARC) to evaluate the effectiveness of three commercially available fixatives in controlling the mobility of soil particles on soil mounds when exposed to varying wind forces. The fixatives tested included: (1) a calcium chloride solution; (2) a petroleum hydrocarbon emulsion; and 3) a synthetic organic. As an initial step, approximately 500 lbs of uncontaminated soil was obtained from the Hanford Reservation in Washington State. Soil samples were placed in an open-loop, low speed wind tunnel and exposed to wind forces ranging from 10 to 30 miles per hour (mph). Wind erosion controlling capabilities of commercially available fixatives and soil moisture were tested at a laboratory

  19. Interactive control of minerals, wildfire, and erosion on soil carbon stabilization in conifer ecosystems of the western U.S.

    NASA Astrophysics Data System (ADS)

    Rasmussen, C.

    2014-12-01

    Answering the question of what controls the fate and stabilization of organic carbon in forest soils is central to understanding the role of western US ecosystems in mitigating climate change, optimizing forest management, and quantifying local and regional terrestrial carbon budgets. Over half of forest soil C is stored belowground, stabilized by a number of separate, but interacting physical, chemical and biological mechanisms. Here we synthesize data from a series of field and laboratory studies focused on identifying mineral, physical, and landscape position controls on belowground C stabilization mechanisms in western U.S. conifer ecosystems. Results from these studies demonstrate an important for role for short-range-order Fe- and Al-oxyhydroxides and Al-humus complexes in C stabilization, and that the soil mineral assemblage moderates C cycling via control on partitioning of C into physical fractions ("free", "occluded", "mineral") with varying MRT and chemistry. Measures of occluded fraction chemical composition by 13C-NMR indicate this fraction is 2-5 times more enriched in pyrogenic C than the bulk soil and that this fraction is on the order of ~25 to 65% charred materials. Radiocarbon analyses of a large set of conifer soil samples from California and Arizona further indicate the occluded fraction is generally older than either the free light or mineral fraction. In particular, soil C in convergent, water and sediment gathering portions of the landscape are enriched in long MRT charred materials. These results indicate an important role for the interaction of soil mineral assemblage, wildfire, and erosion in controlling belowground C storage and stabilization in western conifer forests. Drought and wildfire are expected to increase with climate change and thus may exert significant control on belowground C storage directly through biochemical and physical changes in aboveground biomass, production of charred materials, and indirectly via post

  20. The AFIT gross motion control project

    NASA Technical Reports Server (NTRS)

    Leahy, M. B., Jr.

    1991-01-01

    The objective of the Gross Motion Control project is to study alternative control approaches that will provide payload invariant high speed trajectory tracking for nonrepetitive motions in free space. The research has concentrated on modifications to the model-based control structure. Development and evaluation is being actively pursued of both adaptive primary (inner loop) and robust secondary (output loop) controllers. In-house developments are compared and contrasted to the techniques proposed by other researchers. The case study for the evaluation is the first three links of a PUMA-560. Incorporating the principals of multiple model adaptive estimation, artificial neural networks, and Lyapunov theory into the model based paradigm has shown the potential for enhanced tracking. Secondary controllers based on Quantitative Feedback Theory, or augmented with auxiliary inputs, significantly improve the robustness to payload variations and unmodeled drive system dynamics. An overview is presented of the different concepts under investigation and a sample is provided of the latest experimental results.

  1. Thermal Control System Automation Project (TCSAP)

    NASA Technical Reports Server (NTRS)

    Boyer, Roger L.

    1991-01-01

    Information is given in viewgraph form on the Space Station Freedom (SSF) Thermal Control System Automation Project (TCSAP). Topics covered include the assembly of the External Thermal Control System (ETCS); the ETCS functional schematic; the baseline Fault Detection, Isolation, and Recovery (FDIR), including the development of a knowledge based system (KBS) for application of rule based reasoning to the SSF ETCS; TCSAP software architecture; the High Fidelity Simulator architecture; the TCSAP Runtime Object Database (RODB) data flow; KBS functional architecture and logic flow; TCSAP growth and evolution; and TCSAP relationships.

  2. [Optimization of shelterbelt distribution for the gully erosion control of cultivated slope land in rolling hill black soil region of Northeast China].

    PubMed

    Su, Zi-Long; Cui, Ming; Fan, Hao-Ming

    2012-04-01

    Shelterbelt system is one of the main components of cultivated slope land in rolling hill black soil region of Northeast China, which plays an important role in the control of gully erosion. Based on the Quickbird high-resolution remote sensing image and the digital elevation model (DEM), and combining with field survey data, this paper analyzed the effects of shelterbelt system in a small watershed of rolling hill black soil region in Heshan Farm of Heilongjiang Province on the control of gully erosion in the cultivated slope land, and put forward an optimized scheme for gully erosion control based on the features of gully erosion in the cultivated slope land and their relations with the distribution of the shelterbelt system. In the study area, the current distribution of the shelterbelt system promoted the occurrence and development of shallow gully and gully directly and indirectly. The proposed scheme for optimizing the distribution of the present shelterbelts included the adjustment of the direction of the shelterbelt perpendicular to the aspect of slope, the enhancement of the maintenance and regeneration of the shelterbelts to reduce the gaps of the shelterbelts, the increase of the shelterbelt number, and the decrease of the distances between shelterbelts. A method for calculating the shelterbelt number and the distances between the shelterbelts was also given. This study could provide scientific basis for the gully erosion control and the shelterbelts programming in the cultivated slope land of rolling hill black soil region.

  3. Latitudinal Controls on Topography: The Role of Precipitation and Fluvial Erosion

    NASA Astrophysics Data System (ADS)

    Sorensen, C.; Yanites, B.

    2014-12-01

    Observations from the North and South American Cordillera show that mean and maximum elevations decrease with increasing latitude. The trend in elevation follows the latitudinal dependence of snowline altitudes. This correlation between elevation and snowline altitude has been the impetus behind the glacial 'buzzsaw' hypothesis, which states that glaciers limit the elevation of mountain peaks. Underlying this hypothesis is an assumption that elevations prior to glaciation were either uniform, randomly distributed, or followed a pattern that is no longer present. However, there may be other factors that are responsible for these patterns, such as latitudinal trends in precipitation. Here, we address this assumption and the necessity of glacial erosion in explaining the latitudinal trend in elevation. We use the CHILD landscape evolution model parameterized by modern precipitation data along a latitudinal gradient in the Andes to predict the topography in the absence of glaciation. Using NCEP/NCAR Reanalysis precipitation data from 1981-2010, we derive storm duration, intensity, and frequency statistics for a series of locations along the Andean orogen. For each location, we run a model using a sequence of storms generated from these statistics. Erodibility and rock-uplift are held constant between the different locations and the models are run until topographic steady-state is achieved. We also present runs exploring the role of a threshold for bedrock detachment in the modeled results. For each run, we track the maximum and mean elevation as well as the time to steady-state. Preliminary results for all cases show that fluvial processes alone are sufficient to account for the latitudinal dependence of topography. For example, landscapes produced with precipitation statistics similar to the dry central Andes are more than an order of magnitude higher than landscapes from the southern, wetter, part of the orogen. Future analysis will use precipitation data from

  4. Measurement of the fluorescence of crop residues: A tool for controlling soil erosion

    NASA Technical Reports Server (NTRS)

    Daughtry, C. S. T.; Mcmurtrey, J. E., III; Chappelle, E. W.; Hunter, W. J.

    1994-01-01

    Management of crop residues, the portion of a crop left in the field after harvest, is an important conservation practice for minimizing soil erosion and for improving water quality. Quantification of crop residue cover is required to evaluate the effectiveness of conservation tillage practices. Methods are needed to quantify residue cover that are rapid, accurate, and objective. The fluorescence of crop residue was found to be a broadband phenomenon with emission maxima at 420 to 495 nm for excitations of 350 to 420 nm. Soils had low intensity broadband emissions over the 400 to 690 nm region for excitations of 300 to 600 nm. The range of relative fluorescence intensities for the crop residues was much greater than the fluorescence observed of the soils. As the crop residues decompose their blue fluorescence values approach the fluorescence of the soil. Fluorescence techniques are concluded to be less ambiguous and better suited for discriminating crop residues and soils than reflectance methods. If properly implemented, fluorescence techniques can be used to quantify, not only crop residue cover, but also photosynthetic efficiency in the field.

  5. Soil erosion control, plant diversity, and arthropod communities under heterogeneous cover crops in an olive orchard.

    PubMed

    Gómez, José Alfonso; Campos, Mercedes; Guzmán, Gema; Castillo-Llanque, Franco; Vanwalleghem, Tom; Lora, Ángel; Giráldez, Juan V

    2017-01-30

    A 3-year experiment compared in an olive orchard the effect of different cover crops' composition on runoff, water erosion, diversity of annual plants, and arthropod communities which could provide an alternative to conventional management based on tillage (CT). The cover crops evaluated were a seeded homogeneous grass (GC), a seeded mix of ten different species (MCseeded), and a non-seeded cover by vegetation naturally present at the farm after 20 years of mowing (MCnatural). The results suggest that heterogeneous cover crops can provide a viable alternative to homogeneous ones in olives, providing similar benefits in reducing runoff and soil losses compared to management based on bare soil. The reduction in soil loss was particularly large: 46.7 in CT to 6.5 and 7.9 t ha(-1) year(-1) in GC and MCseeded, respectively. The heterogeneous cover crops resulted in greater diversity of plant species and a modification of the arthropod communities with an increased number of predators for pests. The reduction of the cost of implanting heterogeneous cover crops, improvement of the seeding techniques, and selection of species included in the mixes require additional research to promote the use of this practice which can deliver enhanced environmental benefits.

  6. In-situ measurements of alloy oxidation/corrosion/erosion using a video camera and proximity sensor with microcomputer control

    NASA Technical Reports Server (NTRS)

    Deadmore, D. L.

    1984-01-01

    Two noncontacting and nondestructive, remotely controlled methods of measuring the progress of oxidation/corrosion/erosion of metal alloys, exposed to flame test conditions, are described. The external diameter of a sample under test in a flame was measured by a video camera width measurement system. An eddy current proximity probe system, for measurements outside of the flame, was also developed and tested. The two techniques were applied to the measurement of the oxidation of 304 stainless steel at 910 C using a Mach 0.3 flame. The eddy current probe system yielded a recession rate of 0.41 mils diameter loss per hour and the video system gave 0.27.

  7. Controls on coastal dune morphology, shoreline erosion and barrier island response to extreme storms

    USGS Publications Warehouse

    Houser, C.; Hapke, C.; Hamilton, S.

    2008-01-01

    The response of a barrier island to an extreme storm depends in part on the surge elevation relative to the height and extent of the foredunes which can exhibit considerable variability alongshore. While it is recognized that alongshore variations in dune height and width direct barrier island response to storm surge, the underlying causes of the alongshore variation remain poorly understood. This study examines the alongshore variation in dune morphology along a 11??km stretch of Santa Rosa Island in northwest Florida and relates the variation in morphology to the response of the island during Hurricane Ivan and historic and storm-related rates of shoreline erosion. The morphology of the foredune and backbarrier dunes was characterized before and after Hurricane Ivan using Empirical Orthogonal Function (EOF) analysis and related through Canonical Correlation Analysis (CCA). The height and extent of the foredune, and the presence and relative location of the backbarrier dunes, varied alongshore at discrete length scales (of ~ 750, 1450 and 4550??m) that are statistically significant at the 95% confidence level. Cospectral analysis suggests that the variation in dune morphology is correlated with transverse ridges on the inner-shelf, the backbarrier cuspate headlands, and the historical and storm-related trends in shoreline change. Sections of the coast with little to no dune development before Hurricane Ivan were observed in the narrowest portions of the island (between headlands), west of the transverse ridges. Overwash penetration tended to be larger in these areas and island breaching was common, leaving the surface close to the watertable and covered by a lag of shell and gravel. In contrast, large foredunes and the backbarrier dunes were observed at the widest sections of the island (the cuspate headlands) and at crest of the transverse ridges. Due to the large dunes and the presence of the backbarrier dunes, these areas experienced less overwash penetration

  8. Do erosion rates control the long-term carbon isotope mass balance?

    NASA Astrophysics Data System (ADS)

    Shields-Zhou, G. A.

    2014-12-01

    The long-term marine carbon isotope record responds to changes in the proportional burial rates of organic carbon relative to carbonate carbon on a global scale. For this reason, high δ13C values in marine carbonate rocks are normally interpreted to reflect faster rates of organic burial and increased atmospheric oxygenation. Geochemical redox tracers fail to support this paradigm for sustained deviations from the long-term δ13C mean, indicating perhaps that proportionally high organic burial may be associated with lower overall flux rates. Here I propose that ~107-108 year trends in average δ13C, as with seawater 87Sr/86Sr, are driven by changes in the balance between volcanism and denudation (~uplift). In other words, high proportional organic burial may be related to increases in the net CO2 flux (= organic carbon burial + Ca-Mg silicate weathering) relative to the carbonate weathering flux. According to this model, high baseline δ13C values will be associated with periods of heightened volcanic activity and/or diminished tectonic uplift. Conversely, lower baseline δ13C values can be related to times when the global carbon cycle was dominated by carbonate and oxidative weathering due to high rates of physical erosion. Shorter 105-106 year positive δ13C excursions have also been interpreted as the 'smoking gun' to extreme oxygenation events. However, large increases in organic burial are difficult to sustain under steady-state conditions without very high volcanic fluxes, indicating that some of these excursions might be better explained by transient changes to the isotopic composition of carbon sources and sinks.

  9. A Statistical Project Control Tool for Engineering Managers

    NASA Technical Reports Server (NTRS)

    Bauch, Garland T.

    2001-01-01

    This slide presentation reviews the use of a Statistical Project Control Tool (SPCT) for managing engineering projects. A literature review pointed to a definition of project success, (i.e., A project is successful when the cost, schedule, technical performance, and quality satisfy the customer.) The literature review also pointed to project success factors, and traditional project control tools, and performance measures that are detailed in the report. The essential problem is that with resources becoming more limited, and an increasing number or projects, project failure is increasing, there is a limitation of existing methods and systematic methods are required. The objective of the work is to provide a new statistical project control tool for project managers. Graphs using the SPCT method plotting results of 3 successful projects and 3 failed projects are reviewed, with success and failure being defined by the owner.

  10. Optimal land use management for soil erosion control by using an interval-parameter fuzzy two-stage stochastic programming approach.

    PubMed

    Han, Jing-Cheng; Huang, Guo-He; Zhang, Hua; Li, Zhong

    2013-09-01

    Soil erosion is one of the most serious environmental and public health problems, and such land degradation can be effectively mitigated through performing land use transitions across a watershed. Optimal land use management can thus provide a way to reduce soil erosion while achieving the maximum net benefit. However, optimized land use allocation schemes are not always successful since uncertainties pertaining to soil erosion control are not well presented. This study applied an interval-parameter fuzzy two-stage stochastic programming approach to generate optimal land use planning strategies for soil erosion control based on an inexact optimization framework, in which various uncertainties were reflected. The modeling approach can incorporate predefined soil erosion control policies, and address inherent system uncertainties expressed as discrete intervals, fuzzy sets, and probability distributions. The developed model was demonstrated through a case study in the Xiangxi River watershed, China's Three Gorges Reservoir region. Land use transformations were employed as decision variables, and based on these, the land use change dynamics were yielded for a 15-year planning horizon. Finally, the maximum net economic benefit with an interval value of [1.197, 6.311] × 10(9) $ was obtained as well as corresponding land use allocations in the three planning periods. Also, the resulting soil erosion amount was found to be decreased and controlled at a tolerable level over the watershed. Thus, results confirm that the developed model is a useful tool for implementing land use management as not only does it allow local decision makers to optimize land use allocation, but can also help to answer how to accomplish land use changes.

  11. Greenidge Multi-Pollutant Control Project

    SciTech Connect

    Connell, Daniel

    2008-10-18

    The Greenidge Multi-Pollutant Control Project was conducted as part of the U.S. Department of Energy's Power Plant Improvement Initiative to demonstrate an innovative combination of air pollution control technologies that can cost-effectively reduce emissions of SO{sub 2}, NO{sub x}, Hg, acid gases (SO{sub 3}, HCl, and HF), and particulate matter from smaller coal-fired electric generating units (EGUs). There are about 400 units in the United States with capacities of 50-300 MW that currently are not equipped with selective catalytic reduction (SCR), flue gas desulfurization (FGD), or mercury control systems. Many of these units, which collectively represent more than 55 GW of installed capacity, are difficult to retrofit for deep emission reductions because of space constraints and unfavorable economies of scale, making them increasingly vulnerable to retirement or fuel switching in the face of progressively more stringent environmental regulations. The Greenidge Project sought to confirm the commercial readiness of an emissions control system that is specifically designed to meet the environmental compliance requirements of these smaller coal-fired EGUs by offering a combination of deep emission reductions, low capital costs, small space requirements, applicability to high-sulfur coals, mechanical simplicity, and operational flexibility. The multi-pollutant control system includes a NO{sub x}OUT CASCADE{reg_sign} hybrid selective non-catalytic reduction (SNCR)/in-duct SCR system for NO{sub x} control and a Turbosorp{reg_sign} circulating fluidized bed dry scrubbing system (with a new baghouse) for SO{sub 2}, SO{sub 3}, HCl, HF, and particulate matter control. Mercury removal is provided as a co-benefit of the in-duct SCR, dry scrubber, and baghouse, and by injection of activated carbon upstream of the scrubber, if required. The multi-pollutant control system was installed and tested on the 107-MW{sub e}, 1953-vintage AES Greenidge Unit 4 by a team including

  12. A Permeable Active Amendment Concrete (PAAC) for Contaminant Remediation and Erosion Control

    DTIC Science & Technology

    2012-06-01

    average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed...assistance in the laboratory, data analysis, and project support. SRNL-STI-2012-00356 ii TABLE OF...Procedure (TCLP) desorption data . ... 61  Figure 25. Relationship between pH and number of surviving Hyalella azteca (out of 10) in static bioassay chambers

  13. Field studies of beach cones as coastal erosion control/reversal devices for areas with significant oil and gas activities

    SciTech Connect

    Not Available

    1992-07-17

    A field demonstration/study of a novel shoreline erosion protection device called beach cones is planned. These patented, fiberglass- reinforced concreted devices are to be deployed in a number of geometric patterns at seven location in the Bastian Bay area of Western Plaquemines Parish. The purpose of the work described in this report was to evaluate the proposed study's impact on living and non-living shellfish resources within each of the project's seven separate Study Areas. Major accomplishments for this reporting period were as follows: aerial photographs of the experimental sites were taken; all permit applications were filed; information was submitted for the Environmental Report; several reconnaissance trips to the experimental sites were made; meetings were held among all participating organizations to further plan the research; permit was obtained from the US Army Corps of Engineers; test sites were surveyed by the Xavier University contingent; survey data were taken at all sites; the Oyster Assessment was completed; permit was obtained from the State of Louisiana Department of Natural Resources; and initial survey data were finalized at all sites.

  14. Modeling erosion and sediment control practices in RUSLE 2.0: A management approach for natural gas well sites in Denton County, TX, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sediment yields from natural gas well sites can be substantial and warrant consideration of appropriate erosion and sediment control Best Management Practices(BMPs). Version 2 of the Revised Universal Soil Loss Equation (RUSLE 2.0) was used to predict sediment yields and evaluate the efficiency of ...

  15. Section 32 Program. Streambank Erosion Control, Evaluation and Demonstration. Work Unit 4. Research on Soil Stability and Identification of Causes of Streambank Erosion. Investigation of a Grid for Bank Protection,

    DTIC Science & Technology

    1979-11-01

    NOV 79 A C SPIVEY, C R STYRON UNCLASSIFIED WES-INVESTISATION- 3 SECTION 32 PROGRAM STREAMBANK EROSION CONTROL EVALUATION AND DEMONSTRATION WORK UNIT 4 ...piece of 3 / 4 -in. (19.05-mm) plywood (Photo 5). The front wheels of a half-ton truck were driven on the plywood to press the grids into the soil (Photo...400 300 U 20 0 40 -~ z 0- 0 a 4 0 a 𔃺 12 14 Is is 20 22 24 20 28 30JANUARY Figure 3 .(Sheet 2 of 3 ) 40 -100’ 30- -8’ MAXIMUM -70’ 0 0 0, Z0 40 MINIMUM

  16. Beach Erosion

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Two miles of beach at Cape Canaveral eroded by construction of a port and jetties was recently restored. Such work in harbors of many cities often disrupts normal flow of sand for many miles along coasts. Brevard County, FL residents now enjoy a 400 ft. wide public beach in an area in imminent danger of destructive erosion just a year previously. Before and after aerial photos show how more than two miles of beach were rebuilt with 2.7 million cubic yards of sand helping abate the erosion problem caused by construction of jetties. NASA volunteered its remote-sensing technology and instrumented aircraft to provide low-altitude color infrared photography about every three months since 1972.

  17. Erosion dynamics in Chile

    NASA Astrophysics Data System (ADS)

    Carretier, Sebastien; Tolorza, Violeta; Regard, Vincent; Riquelme, Rodrigo; Aguilar, German

    2016-04-01

    Erosion and sediment transport in arid environments is thought to depend on the frequency of large floods as well as on mean precipitation rate and slope, but their relative impact remains a matter of active debate. The Chilean Andes are elongated along a sharp precipitation rate gradient, offering the possibility to rank these factors over different time spans. We compare suspended load measurements-derived decennial erosion rates and 10Be-derived millennial erosion rates along this gradient. Both parameters follow the same latitudinal trend and peak where the climate is Mediterranean (mean runoff ~0.55 m/m), confirming that slope is the main factor even along this contrasted climate. The comparison of these erosion rates documents the progressive contribution of rare and strong climatic events on the millennial erosion from humid to arid catchments. In the wetter BíoBio catchment, the separation of suspended sediment yield during base and direct flows shows that the dynamics of groundwater circulation controls most of the sediment hysteresis at gauging stations at annual scale. In addition, the mega El Maule earthquake (Mw8.8 in 2010), in front of humid to semi-arid catchments, has not increased the suspended sediment concentration in rivers, excepted in the steepest and driest catchments. Over millennial scales, preliminary 10Be concentrations in individual gravels and cobbles suggest mean river transport rates of several m/yr in an arid canyon of north Chile.

  18. Floodplain Assessment for the Proposed Engineered Erosion Controls at TA-72 in Lower Sandia Canyon, Los Alamos National Laboratory

    SciTech Connect

    Hathcock, Charles D.

    2012-08-27

    Los Alamos National Laboratory (LANL) is preparing to implement engineering controls in Sandia Canyon at Technical Area (TA) 72. Los Alamos National Security (LANS) biologists conducted a floodplain determination and this project is located within a 100-year floodplain. The proposed project is to rehabilitate the degraded channel in lower Sandia Canyon where it crosses through the outdoor firing range at TA-72 to limit the loss of sediment and dissipate floodwater leaving LANL property (Figure 1). The proposed construction of these engineered controls is part of the New Mexico Environment Department's (NMED) approved LANL Individual Storm Water Permit. The purpose of this project is to install storm water controls at Sandia Watershed Site Monitoring Area 6 (S-SMA-6). Storm water controls will be designed and installed to meet the requirements of NPDES Permit No. NM0030759, commonly referred to as the LANL Individual Storm Water Permit (IP). The storm water control measures address storm water mitigation for the area within the boundary of Area of Concern (AOC) 72-001. This action meets the requirements of the IP for S-SMA-6 for storm water controls by a combination of: preventing exposure of upstream storm water and storm water generated within the channel to the AOC and totally retaining storm water falling outside the channel but within the AOC.

  19. A wood-strand material for wind erosion control: effects on total sediment loss, PM10 vertical flux, and PM10 loss.

    PubMed

    Copeland, N S; Sharratt, B S; Wu, J Q; Foltz, R B; Dooley, J H

    2009-01-01

    Fugitive dust from eroding land poses risks to environmental quality and human health, and thus, is regulated nationally based on ambient air quality standards for particulate matter with mean aerodynamic diameter < or = 10 microm (PM10) established in the Clean Air Act. Agricultural straw has been widely used for rainfall-induced erosion control; however, its performance for wind erosion mitigation has been less studied, in part because straw is mobile at moderate wind velocities. A wood-based long-strand material has been developed for rainfall-induced erosion control and has shown operational promise for control of wind-induced erosion and dust emissions from disturbed sites. The purpose of this study was to evaluate the efficacy of both agricultural straw and wood-strand materials in controlling wind erosion and fugitive dust emissions under laboratory conditions. Wind tunnel tests were conducted to compare wood strands of several geometries to agricultural wheat straw and bare soil in terms of total sediment loss, PM10 vertical flux, and PM10 loss. Results indicate that the types of wood strands tested are stable at wind speeds of up to 18 m s(-1), while wheat straw is only stable at speeds of up to 6.5 m s(-1). Wood strands reduced total sediment loss and PM10 emissions by 90% as compared to bare soil across the range of wind speeds tested. Wheat straw did not reduce total sediment loss for the range of speeds tested, but did reduce PM10 emissions by 75% compared to a bare soil at wind speeds of up to 11 m s(-1).

  20. Dust and Erosion Control Methods for US Army Construction Projects in Honduras

    DTIC Science & Technology

    1989-06-01

    necetury and Identify by block number) A joint US/ Honduran venture to develop the infrastructure of Honduras includes the construction of several roads and...joint US/ Honduran venture to develop the infrastructure of Honduras. As part of the venture, several roads and airfields are being con- structed. This...multistoried for- ests that form a dense, continuous canopy. The upper story is dominated by hardwood species such as mahogany , laurel, castilla

  1. A Constructability Study of the Sargent Beach, Texas Erosion Control Project

    DTIC Science & Technology

    1993-12-01

    Following contract award, using either in- house personnel or an independent materials testing laboratory, the COE should verify the quality of the proposed...the names of their proposed material suppliers with their bids. 2. That following contract award, the COE verify, using either in- house personnel or...Government Furnished Facilities, Materials , or Equipment ........ 43 5.1.1 General ........................................................ 43 5.1.2 Mooring

  2. Detailed Project Report. Liza Jackson Park. Shoreline Erosion Control at Fort Walton Beach, Florida.

    DTIC Science & Technology

    1984-06-01

    Oligoplites saurus) F, P Lemon shark (Negaprion brevirostris) F, Nt Longnose gar (Lepisosteus osseus) F, P Longnose killifish (Fundulus similis) F, R...N, P Scalloped hammerhead (Sphyrna lewini) F, Nt Scrawled cowfish (Acanthostracion quadriocornis) F, R, Nu, P Sea catfish (Arius felis) F, Nu, R, P...tiburo) F, Nt Bull, shark (Carcharhinus leucas) F, Nt Chain pipefish (Snygnathus louisianae) F, R, Nu, GR N Chainell catfish (Ictalurus punctatus) F

  3. Controlled Ecological Life Support System Breadboard Project - 1988

    NASA Technical Reports Server (NTRS)

    Knott, W. M.

    1989-01-01

    The Controlled Ecological Life Support System (CELSS) Breadboard Project, NASA's effort to develop the technology required to produce a functioning bioregenerative system, is discussed. The different phases of the project and its current status are described. The relationship between the project components are shown, and major project activities for fiscal years 1989-1993 are listed. The biomass production chamber to be used by the project is described.

  4. Climatic control on erosion in the Himalayas over the past 40 ka

    NASA Astrophysics Data System (ADS)

    Dosseto, A.; Hesse, P. P.; Fink, D.; Singh, T.; Srivastava, P.

    2012-12-01

    How do fluvial systems adapt to climate variability and what are the implications for weathering fluxes and the global carbon budget? One possible approach to tackle these questions is to re-construct how the residence time of sediments in river basins has varied over time. This is done by measuring the fractionation between uranium isotopes in sediments deposited on fluvial terraces. Samples have been collected from sedimentary deposits in three catchments draining the Lesser Himalayas to investigate how fluvial systems have responded to past climate change in this region: the Yamuna River, the Alaknanda River (upper Ganges) and the Donga Fan (located between the Yamuna and the Ganges). Results from the Yamuna and Donga Fan suggest a decrease in sediment residence time during the last deglaciation by a factor 2-3. This coincides with an intensification of the monsoon. Contrastingly, sediment residence time in the Alaknanda is very short (<10 ka) which suggests rapid sediment transport in this river. Because of this short residence time, weathering flux from the Alaknanda is inferred to be minimal and the impact on atmospheric carbon dioxide consumption negligible. Conversely, the decrease in residence time in the Yamuna and Donga Fan as a result of monsoon intensification can be modelled to infer a significant decrease in weathering consumption at the end of the Pleistocene. Thus, the rise of atmospheric carbon dioxide at the transition into the Holocene could have been promoted by this climatically-controlled decrease in weathering fluxes.

  5. Coprates Erosion

    NASA Technical Reports Server (NTRS)

    2006-01-01

    4 June 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows layered, light-toned, sedimentary rocks that have been exposed by erosion in Coprates Chasma, one of the many chasms which comprise the Valles Marineris trough system on Mars.

    Location near: 13.1oS, 65.0oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Autumn

  6. Quantification of swelling and erosion in the controlled release of a poorly water-soluble drug using synchrotron X-ray computed microtomography.

    PubMed

    Yin, Xianzhen; Li, Haiyan; Guo, Zhen; Wu, Li; Chen, Fangwei; de Matas, Marcel; Shao, Qun; Xiao, Tiqiao; York, Peter; He, You; Zhang, Jiwen

    2013-10-01

    The hydration layer plays a key role in the controlled drug release of gel-forming matrix tablets. For poorly water-soluble drugs, matrix erosion is considered as the rate limiting step for drug release. However, few investigations have reported on the quantification of the relative importance of swelling and erosion in the release of poorly soluble drugs, and three-dimensional (3D) structures of the hydration layer are poorly understood. Here, we employed synchrotron radiation X-ray computed microtomography with 9-μm resolution to investigate the hydration dynamics and to quantify the relative importance of swelling and erosion on felodipine release by a statistical model. The 3D structures of the hydration layer were revealed by the reconstructed 3D rendering of tablets. Twenty-three structural parameters related to the volume, the surface area (SA), and the specific surface area (SSA) for the hydration layer and the tablet core were calculated. Three dominating parameters, including SA and SSA of the hydration layer (SA hydration layer and SSA hydration layer ) and SA of the glassy core (SA glassy core ), were identified to establish the statistical model. The significance order of independent variables was SA hydration layer > SSA hydration layer > SA glassy core , which quantitatively indicated that the release of felodipine was dominated by a combination of erosion and swelling. The 3D reconstruction and structural parameter calculation methods in our study, which are not available from conventional methods, are efficient tools to quantify the relative importance of swelling and erosion in the controlled release of poorly soluble drugs from a structural point of view.

  7. Application of video-cameras for quality control and sampling optimisation of hydrological and erosion measurements in a catchment

    NASA Astrophysics Data System (ADS)

    Lora-Millán, Julio S.; Taguas, Encarnacion V.; Gomez, Jose A.; Perez, Rafael

    2014-05-01

    Long term soil erosion studies imply substantial efforts, particularly when there is the need to maintain continuous measurements. There are high costs associated to maintenance of field equipment keeping and quality control of data collection. Energy supply and/or electronic failures, vandalism and burglary are common causes of gaps in datasets, reducing their reach in many cases. In this work, a system of three video-cameras, a recorder and a transmission modem (3G technology) has been set up in a gauging station where rainfall, runoff flow and sediment concentration are monitored. The gauging station is located in the outlet of an olive orchard catchment of 6.4 ha. Rainfall is measured with one automatic raingauge that records intensity at one minute intervals. The discharge is measured by a flume of critical flow depth, where the water is recorded by an ultrasonic sensor. When the water level rises to a predetermined level, the automatic sampler turns on and fills a bottle at different intervals according to a program depending on the antecedent precipitation. A data logger controls the instruments' functions and records the data. The purpose of the video-camera system is to improve the quality of the dataset by i) the visual analysis of the measurement conditions of flow into the flume; ii) the optimisation of the sampling programs. The cameras are positioned to record the flow at the approximation and the gorge of the flume. In order to contrast the values of ultrasonic sensor, there is a third camera recording the flow level close to a measure tape. This system is activated when the ultrasonic sensor detects a height threshold, equivalent to an electric intensity level. Thus, only when there is enough flow, video-cameras record the event. This simplifies post-processing and reduces the cost of download of recordings. The preliminary contrast analysis will be presented as well as the main improvements in the sample program.

  8. Influence of inhomogeneous static magnetic field-exposure on patients with erosive gastritis: a randomized, self- and placebo-controlled, double-blind, single centre, pilot study

    PubMed Central

    Juhász, Márk; Nagy, Viktor L.; Székely, Hajnal; Kocsis, Dorottya; Tulassay, Zsolt; László, János F.

    2014-01-01

    This pilot study was devoted to the effect of static magnetic field (SMF)-exposure on erosive gastritis. The randomized, self- and placebo-controlled, double-blind, pilot study included 16 patients of the 2nd Department of Internal Medicine, Semmelweis University diagnosed with erosive gastritis. The instrumental analysis followed a qualitative (pre-intervention) assessment of the symptoms by the patient: lower heartburn (in the ventricle), upper heartburn (in the oesophagus), epigastric pain, regurgitation, bloating and dry cough. Medical diagnosis included a double-line upper panendoscopy followed by 30 min local inhomogeneous SMF-exposure intervention at the lower sternal region over the stomach with peak-to-peak magnetic induction of 3 mT and 30 mT m−1 gradient at the target site. A qualitative (post-intervention) assessment of the same symptoms closed the examination. Sham- or SMF-exposure was used in a double-blind manner. The authors succeeded in justifying the clinically and statistically significant beneficial effect of the SMF- over sham-exposure on the symptoms of erosive gastritis, the average effect of inhibition was 56% by p = 0.001, n = 42 + 96. This pilot study was aimed to encourage gastroenterologists to test local, inhomogeneous SMF-exposure on erosive gastritis patients, so this intervention may become an evidence-based alternative or complementary method in the clinical use especially in cases when conventional therapy options are contraindicated. PMID:25008086

  9. Influence of inhomogeneous static magnetic field-exposure on patients with erosive gastritis: a randomized, self- and placebo-controlled, double-blind, single centre, pilot study.

    PubMed

    Juhász, Márk; Nagy, Viktor L; Székely, Hajnal; Kocsis, Dorottya; Tulassay, Zsolt; László, János F

    2014-09-06

    This pilot study was devoted to the effect of static magnetic field (SMF)-exposure on erosive gastritis. The randomized, self- and placebo-controlled, double-blind, pilot study included 16 patients of the 2nd Department of Internal Medicine, Semmelweis University diagnosed with erosive gastritis. The instrumental analysis followed a qualitative (pre-intervention) assessment of the symptoms by the patient: lower heartburn (in the ventricle), upper heartburn (in the oesophagus), epigastric pain, regurgitation, bloating and dry cough. Medical diagnosis included a double-line upper panendoscopy followed by 30 min local inhomogeneous SMF-exposure intervention at the lower sternal region over the stomach with peak-to-peak magnetic induction of 3 mT and 30 mT m(-1) gradient at the target site. A qualitative (post-intervention) assessment of the same symptoms closed the examination. Sham- or SMF-exposure was used in a double-blind manner. The authors succeeded in justifying the clinically and statistically significant beneficial effect of the SMF- over sham-exposure on the symptoms of erosive gastritis, the average effect of inhibition was 56% by p = 0.001, n = 42 + 96. This pilot study was aimed to encourage gastroenterologists to test local, inhomogeneous SMF-exposure on erosive gastritis patients, so this intervention may become an evidence-based alternative or complementary method in the clinical use especially in cases when conventional therapy options are contraindicated.

  10. Relations between rainfall–runoff-induced erosion and aeolian deposition at archaeological sites in a semi-arid dam-controlled river corridor

    USGS Publications Warehouse

    Collins, Brian; Bedford, David; Corbett, Skye; Fairley, Helen; Cronkite-Ratcliff, Collin

    2016-01-01

    Process dynamics in fluvial-based dryland environments are highly complex with fluvial, aeolian, and alluvial processes all contributing to landscape change. When anthropogenic activities such as dam-building affect fluvial processes, the complexity in local response can be further increased by flood- and sediment-limiting flows. Understanding these complexities is key to predicting landscape behavior in drylands and has important scientific and management implications, including for studies related to paleoclimatology, landscape ecology evolution, and archaeological site context and preservation. Here we use multi-temporal LiDAR surveys, local weather data, and geomorphological observations to identify trends in site change throughout the 446-km-long semi-arid Colorado River corridor in Grand Canyon, Arizona, USA, where archaeological site degradation related to the effects of upstream dam operation is a concern. Using several site case studies, we show the range of landscape responses that might be expected from concomitant occurrence of dam-controlled fluvial sand bar deposition, aeolian sand transport, and rainfall-induced erosion. Empirical rainfall-erosion threshold analyses coupled with a numerical rainfall–runoff–soil erosion model indicate that infiltration-excess overland flow and gullying govern large-scale (centimeter- to decimeter-scale) landscape changes, but that aeolian deposition can in some cases mitigate gully erosion. Whereas threshold analyses identify the normalized rainfall intensity (defined as the ratio of rainfall intensity to hydraulic conductivity) as the primary factor governing hydrologic-driven erosion, assessment of false positives and false negatives in the dataset highlight topographic slope as the next most important parameter governing site response. Analysis of 4+ years of high resolution (four-minute) weather data and 75+ years of low resolution (daily) climate records indicates that dryland erosion is dependent on short

  11. Section 32 Program. Streambank Erosion Control, Evaluation and Demonstration. Work Unit 2. Evaluation of Existing Bank Protection. Field Inspection of Morameal Revetment on the Red River,

    DTIC Science & Technology

    1979-09-01

    INSPECTION OF MORAMEAL REVETMENT ON THE RED RIVER by .0 Malcolm P. Keown, E. A. Dardeau, Jr. Hydraulics Laboratory U. S . Army Engineer Waterways...Engineers, U. S . Army Washington, D. C. 20314 e* 0 v W W .. v W W A-4 . .. . . .. . SECTION 32 PROGRAM STREAM4BANK EROSION CONTROL EVALUATION AND...mile 256.6 (mileage established in 1967 by the Corps of Engineers). The revetment was inspected by the U. S . Army Engineer Waterways Experiment Station

  12. Effect of erosion-control structures on sediment and nutrient transport, Edgewood Creek drainage, Lake Tahoe basin, Nevada, 1981-83

    USGS Publications Warehouse

    Garcia, K.T.

    1988-01-01

    Three sites in the Edgewood Creek basin with a combined drainage area of about 1.2 sq mi were selected to assess the effect of erosion-control structures along Nevada State Highway 207, on sediment and nutrient transport. The flow at site one is thought to have been largely unaffected by urban development, and was completely unaffected by erosion control structures. The flow at site two was from a basin affected by urban development and erosion control structures. Site three was downstream from the confluence of streams measured at sites one and two. Most data on streamflow and water quality were collected between June 1981 and May 1983 to assess the hydrologic characteristics of the three sites. As a result of the erosion control structures, mean annual concentrations of total sediment were reduced from about 24,000 to about 410 mg/l at site two and from about 1,900 to about 190 ml/l at site three. Sediment loads were reduced from about 240 to about 10 tons/year at site two and from about 550 to about 110 tons/year at site three. At site one, in contrast, mean concentrations and loads remained low throughout the study period. At site two, sediment particle size changed from predominately coarse prior to construction, to predominately fine thereafter; at site three, it changed from about half coarse sediments to predominately fine. Mean concentration and loads of total iron also were significantly reduced after construction at sites two and three, whereas mean concentrations of nitrogen and phosphorus species did not change appreciably. (Author 's abstract)

  13. The Streambank Erosion Control Evaluation and Demonstration Act of 1974, Section 32, Public Law 93-251. Appendix A. Literature Survey.

    DTIC Science & Technology

    1981-12-01

    Activities," presented at International Workshop on Engineering Problems S in the Management of Gravel-Bed Rivers, Newton , Wales, United Kingdom...Wetlands, Lake Buena Vista, Fla., American Water Resources Association, Minneapolis, S Minn., pp 403-414. Allsap, F., and Johns, J. H. 1973. "The Story of...9R21 131 THE STRERMBANC EROSION CONTROL EVALUATION AND -- 5 DEMONSTRATION ACT OF 1974 S .. (U) ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS

  14. Self-Correcting HVAC Controls Project Final Report

    SciTech Connect

    Fernandez, Nicholas; Brambley, Michael R.; Katipamula, Srinivas; Cho, Heejin; Goddard, James K.; Dinh, Liem H.

    2010-01-04

    This document represents the final project report for the Self-Correcting Heating, Ventilating and Air-Conditioning (HVAC) Controls Project jointly funded by Bonneville Power Administration (BPA) and the U.S. Department of Energy (DOE) Building Technologies Program (BTP). The project, initiated in October 2008, focused on exploratory initial development of self-correcting controls for selected HVAC components in air handlers. This report, along with the companion report documenting the algorithms developed, Self-Correcting HVAC Controls: Algorithms for Sensors and Dampers in Air-Handling Units (Fernandez et al. 2009), document the work performed and results of this project.

  15. Erosion resistance of irrigated soils in the republic of Azerbaijan

    NASA Astrophysics Data System (ADS)

    Babaev, M. P.; Gurbanov, E. A.

    2010-12-01

    It was found that the average size of water-stable aggregates in irrigated soils varies in the range 0.23-2.0 mm, and the eroding flow velocity is 0.03-0.12 m/s. A five-point scale was used for assessing erosion resistance, predicting irrigation erosion, and developing erosion control measures on irrigated soils. According to this system, gray-brown soils and light sierozems were classified as the least erosion-resistant, sierozemic and meadow-sierozemic soils as low erosion-resistant, gray-cinnamonic soils as moderately erosion-resistant, mountain gray-cinnamonic soils as highly erosion-resistant, and steppe mountain cinnamonic soils as very highly erosion-resistant ones. The determination of the erosion resistance of soils is of great importance for assessing the erosion-resistance potential of irrigated areas and developing erosion control measures.

  16. Effects of salinity and particle concentration on sediment hydrodynamics and critical bed-shear-stress for erosion of fine grained sediments used in wetland restoration projects

    NASA Astrophysics Data System (ADS)

    Ghose-Hajra, M.; McCorquodale, A.; Mattson, G.; Jerolleman, D.; Filostrat, J.

    2015-03-01

    Sea-level rise, the increasing number and intensity of storms, oil and groundwater extraction, and coastal land subsidence are putting people and property at risk along Louisiana's coast, with major implications for human safety and economic health of coastal areas. A major goal towards re-establishing a healthy and sustainable coastal ecosystem has been to rebuild Louisiana's disappearing wetlands with fine grained sediments that are dredged or diverted from nearby rivers, channels and lakes to build land in open water areas. A thorough geo-hydrodynamic characterization of the deposited sediments is important in the correct design and a more realistic outcome assessment of the long-term performance measures for ongoing coastal restoration projects. This paper evaluates the effects of salinity and solid particle concentration on the re-suspension characteristics of fine-grained dredged sediments obtained from multiple geographic locations along the Gulf coast. The critical bed-shear-stress for erosion has been evaluated as a function of sedimentation time. The sediment hydrodynamic properties obtained from the laboratory testing were used in a numerical coastal sediment distribution model to aid in evaluating sediment diversions from the Mississippi River into Breton Sound and Barataria Bay.

  17. Abnormal monsoon years and their control on erosion and sediment flux in the high, arid northwest Himalaya

    NASA Astrophysics Data System (ADS)

    Bookhagen, Bodo; Thiede, Rasmus C.; Strecker, Manfred R.

    2005-02-01

    circulation. Hence, episodically occurring AMYs control geomorphic processes primarily in the high-elevation arid sectors of the orogen, while annual recurring monsoonal rainfall distribution dominates erosion in the low- to medium-elevation parts along the SHF.

  18. Guidance and Control Software Project Data - Volume 1: Planning Documents

    NASA Technical Reports Server (NTRS)

    Hayhurst, Kelly J. (Editor)

    2008-01-01

    The Guidance and Control Software (GCS) project was the last in a series of software reliability studies conducted at Langley Research Center between 1977 and 1994. The technical results of the GCS project were recorded after the experiment was completed. Some of the support documentation produced as part of the experiment, however, is serving an unexpected role far beyond its original project context. Some of the software used as part of the GCS project was developed to conform to the RTCA/DO-178B software standard, "Software Considerations in Airborne Systems and Equipment Certification," used in the civil aviation industry. That standard requires extensive documentation throughout the software development life cycle, including plans, software requirements, design and source code, verification cases and results, and configuration management and quality control data. The project documentation that includes this information is open for public scrutiny without the legal or safety implications associated with comparable data from an avionics manufacturer. This public availability has afforded an opportunity to use the GCS project documents for DO-178B training. This report provides a brief overview of the GCS project, describes the 4-volume set of documents and the role they are playing in training, and includes the planning documents from the GCS project. Volume 1 contains five appendices: A. Plan for Software Aspects of Certification for the Guidance and Control Software Project; B. Software Development Standards for the Guidance and Control Software Project; C. Software Verification Plan for the Guidance and Control Software Project; D. Software Configuration Management Plan for the Guidance and Control Software Project; and E. Software Quality Assurance Activities.

  19. Guidance and Control Software Project Data - Volume 2: Development Documents

    NASA Technical Reports Server (NTRS)

    Hayhurst, Kelly J. (Editor)

    2008-01-01

    The Guidance and Control Software (GCS) project was the last in a series of software reliability studies conducted at Langley Research Center between 1977 and 1994. The technical results of the GCS project were recorded after the experiment was completed. Some of the support documentation produced as part of the experiment, however, is serving an unexpected role far beyond its original project context. Some of the software used as part of the GCS project was developed to conform to the RTCA/DO-178B software standard, "Software Considerations in Airborne Systems and Equipment Certification," used in the civil aviation industry. That standard requires extensive documentation throughout the software development life cycle, including plans, software requirements, design and source code, verification cases and results, and configuration management and quality control data. The project documentation that includes this information is open for public scrutiny without the legal or safety implications associated with comparable data from an avionics manufacturer. This public availability has afforded an opportunity to use the GCS project documents for DO-178B training. This report provides a brief overview of the GCS project, describes the 4-volume set of documents and the role they are playing in training, and includes the development documents from the GCS project. Volume 2 contains three appendices: A. Guidance and Control Software Development Specification; B. Design Description for the Pluto Implementation of the Guidance and Control Software; and C. Source Code for the Pluto Implementation of the Guidance and Control Software

  20. Western Lake Erie Shore Study, Ohio. Reconnaissance Report (Stage 1) on Flood Protection and Shoreline Erosion Control,

    DTIC Science & Technology

    1981-06-01

    Representatives, United States, that the Board of Engineers for Rivers and Harbors is hereby requested to review the report, Lake Erie Shore Line from the...FFR and its recommendations is reviewed by the North Central Division of the Corps, the Board of Engineers for Rivers and Harbors, the Office of the...Erosion and Beach Restoration at Maumee Bay State Park, Ohio under the Western Lake Erie Shore study authorization. Approval to conduct this interim

  1. Technology Transfer of Biopolymer Soil Amendment for Rapid Revegetation and Erosion Control at Fort A. P. Hill, Virginia

    DTIC Science & Technology

    2016-05-01

    consisting of a polysaccharide polymeric material, a natural product of plant/soil rhyzobial microbial activity, was demonstrated to enhance site...its prolific production of a gel-like, extracellular polymeric substance (EPS), a biopolymer (Gil-Serrano et al. 1990). The natural functions of the...TN) evaluates application of this biopolymer to a highly disturbed and erodible soil. BACKGROUND: Most training areas present soil erosion

  2. DA-9601 for erosive gastritis: Results of a double-blind placebo-controlled phase III clinical trial

    PubMed Central

    Seol, Sang Yong; Kim, Myung Hwan; Ryu, Jong Sun; Choi, Myung Gyu; Shin, Dong Wook; Ahn, Byoung Ok

    2004-01-01

    AIM: To determine the efficacy and safety of DA-9601 on erosive gastritis versus cetraxate as a standard drug by gastrointestinal endoscopy. METHODS: Five hundred and twelve patients with erosive gastritis were divided into three groups. The groups received 180 mg or 360 mg of DA-9601, or 600 mg of cetraxate (NeuerTM) t.i.d. for 2 wk, respectively. Endoscopic observations were performed before and 2 wk after the treatment, and the cure and improvement rates were investigated. RESULTS: Of the 512 intention-to-treat (ITT) population, 457 patients comprised the per protocol (PP) analysis. Endoscopic cure rate was significantly higher in the DA-9601 group than in the cetraxate group in both the PP (56%, 58% vs 36%; DA-9601 180 mg, 360 mg and cetraxate, respectively) and ITT (52%, 51% vs 35%) populations. Two DA-9601 groups (180 and 360 mg) had significantly higher endoscopic improvement rates than the cetraxate group in both the PP (67%, 65% vs 46%) and ITT (63%, 58% vs 45%) populations. The percentage of symptom relief over the 2 wk was found not significantly different between groups. During the study, both DA-9601 and cetraxate produced no treatment-associated adverse events. CONCLUSION: From these results, it appears that DA-9601 has excellent efficacy on erosive gastritis. This study also confirms the safety profile of DA-9601. PMID:15285023

  3. Late Quaternary glacial relief evolution and fracture-density control on erosion revealed by low-temperature thermochronometry and remote sensing (Granite Range, Alaska)

    NASA Astrophysics Data System (ADS)

    Valla, Pierre; Champagnac, Jean-Daniel; Herman, Frédéric; Lowick, Sally; Guralnik, Benny; Shuster, David; Fellin, Giuditta

    2013-04-01

    Long-term erosion and topographic evolution of mountain belts arise from complex coupling between tectonics, climate and surface processes. The Granite Range (Wrangell-St Elias National Park, Alaska) presents an ideal setting to study such interactions. Its alpine landscape, preserving typical glacial features (U-shaped valleys, cirques), appears highly smoothed in the west, and progressively more rugged towards the east. In the field, this is evidenced by minor and only localized faulting of massive bedrock (granite and paragneiss) in the west, while the eastern part shows highly fractured bedrock (penetrative faults, fault gouges). Remote-sensing analysis confirms that fracture density is much higher towards east, and also reveals high post-glacial incision only in areas associated with high fracture density. To quantify our morphometric observations, we sampled four elevation profiles (~15 samples in total) over an 80-km East-West transect for low-temperature thermochrometry. Apatite (U-Th-Sm)/He dating provides ages between ~10 and 30 Ma, in agreement with published data, and shows apparent low long-term exhumation rates (~0.05-0.1 km/Ma). Preliminary 4He/3He thermochronometry data reveal a more complex exhumation history, with a significant increase since ~6-5 Ma which can be related to either onset of glaciations in Alaska or a major change in tectonic activity occurring at that period. Further data collected within the Granite Range will help to decipher the origin of this late-Miocene acceleration in exhumation. We also performed luminescence thermochronometry measured on feldspar separates from bedrock samples. Our results show a strong East-West gradient in samples saturation ratio. Apparent ages vary from ~250 ka in the western part of the range, towards younger ages of ~30 ka in the east. This pattern reveals spatially variable erosion rates during the late Quaternary associated with a major fracture-density control on erosion, and further supports the

  4. First-of-A-Kind Control Room Modernization Project Plan

    SciTech Connect

    Thomas, Kenneth David

    2016-02-01

    This project plan describes a comprehensive approach to the design of an end-state concept for a modernized control room for Palo Verde. It describes the collaboration arrangement between the DOE LWRS Program Control Room Modernization Project and the APS Palo Verde Nuclear Generating Station. It further describes the role of other collaborators, including the Institute for Energy Technology (IFE) and the Electric Power Research Institute (EPRI). It combines advanced tools, methodologies, and facilities to enable a science-based approach to the validation of applicable engineering and human factors principles for nuclear plant control rooms. It addresses the required project results and documentation to demonstrate compliance with regulatory requirements. It describes the project tasks that will be conducted in the project, and the deliverable reports that will be developed through these tasks. This project plan will be updated as new tasks are added and as project milestones are completed. It will serve as an ongoing description on the project both for project participants and for industry stakeholders.

  5. MINE WASTE TECHNOLOGY PROGRAM - UNDERGROUND MINE SOURCE CONTROL DEMONSTRATION PROJECT

    EPA Science Inventory

    This report presents results of the Mine Waste Technology Program Activity III, Project 8, Underground Mine Source Control Demonstration Project implemented and funded by the U. S. Environmental Protection Agency (EPA) and jointly administered by EPA and the U. S. Department of E...

  6. Design of decentralized multivariable excitation controllers in multimachine power systems by projective controls

    SciTech Connect

    Arnautovic, D.; Medanic, J.

    1987-12-01

    A methodology for the design of decentralized multivariable excitation and controllers in multimachine power systems is developed using projective controls. The existing methodology, is extended to permit the coordinated design of AVR and PSS controllers in power systems.

  7. An Open Specification for Space Project Mission Operations Control Architectures

    NASA Technical Reports Server (NTRS)

    Hooke, A.; Heuser, W. R.

    1995-01-01

    An 'open specification' for Space Project Mission Operations Control Architectures is under development in the Spacecraft Control Working Group of the American Institute for Aeronautics and Astro- nautics. This architecture identifies 5 basic elements incorporated in the design of similar operations systems: Data, System Management, Control Interface, Decision Support Engine, & Space Messaging Service.

  8. Controls on project proponents and environmental impact assessment effectiveness

    SciTech Connect

    Ortolano, L. )

    1993-01-01

    The degree of effectiveness of environmental impact assessment (EIA) for particular projects is associated with the existence of mechanisms of organizational control. Five dimensions of EIA effectiveness are considered: procedural compliance, completeness of EIA documents, methods to assess impacts, influence on project decisions, and weight given to environmental factors. Six mechanisms of control are introduced and illustrated by programs and projects in several countries. Experience in the Philippines under President Marcos demonstrates that procedural control in the form of EIA regulations, when used without other control mechanisms, will lead at most to token compliance. Judicial control, as practiced in the US, yields high procedural compliance. Evaluative control can yield effective EIA, but some systems based on this form of control treat only a small fraction of the major projects proposed. Both control exerted by development assistance organizations and control by professionals have great potential for yielding effective EIA, but that potential has not been fully realized. Control exerted directly by citizens or agencies not otherwise involved in EIA is uncommon, but cases from Taiwan demonstrate that those controls can be significant. An understanding of relationships between control mechanisms and EIA effectiveness is useful in designing EIA policies and programs.

  9. MILA Antenna Control Unit Replacement Project

    NASA Technical Reports Server (NTRS)

    Bresette, Jeremy

    2007-01-01

    The Air to Ground Subsystem (AGS) Antenna Control Units at the MILA Ground Network Tracking Station are at end-of-life and are being replaced. AGS consists of two antennas at MILA (Quad-Helix and Teltrac). Software was taken from the existing Subsystem Controller and modified for the Antenna Control Unit (ACU). The software is capable of receiving and sending commands to and from the ACU. Moving the azimuth clockwise, counterclockwise, moving the elevation up or down, turning servo power on and off, and inputting azimuth and elevation angles are commands that the antenna can receive.

  10. Rebuilding Habitat and Shoreline Resilience through Improved Flood Control Project

    EPA Pesticide Factsheets

    Information about the SFBWQP Rebuilding Habitat and Shoreline Resilience through Improved Flood Control Project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  11. Controlled Hydrogen Fleet and Infrastructure Demonstration Project

    SciTech Connect

    Dr. Scott Staley

    2010-03-31

    This program was undertaken in response to the US Department of Energy Solicitation DE-PS30-03GO93010, resulting in this Cooperative Agreement with the Ford Motor Company and BP to demonstrate and evaluate hydrogen fuel cell vehicles and required fueling infrastructure. Ford initially placed 18 hydrogen fuel cell vehicles (FCV) in three geographic regions of the US (Sacramento, CA; Orlando, FL; and southeast Michigan). Subsequently, 8 advanced technology vehicles were developed and evaluated by the Ford engineering team in Michigan. BP is Ford's principal partner and co-applicant on this project and provided the hydrogen infrastructure to support the fuel cell vehicles. BP ultimately provided three new fueling stations. The Ford-BP program consists of two overlapping phases. The deliverables of this project, combined with those of other industry consortia, are to be used to provide critical input to hydrogen economy commercialization decisions by 2015. The program's goal is to support industry efforts of the US President's Hydrogen Fuel Initiative in developing a path to a hydrogen economy. This program was designed to seek complete systems solutions to address hydrogen infrastructure and vehicle development, and possible synergies between hydrogen fuel electricity generation and transportation applications. This project, in support of that national goal, was designed to gain real world experience with Hydrogen powered Fuel Cell Vehicles (H2FCV) 'on the road' used in everyday activities, and further, to begin the development of the required supporting H2 infrastructure. Implementation of a new hydrogen vehicle technology is, as expected, complex because of the need for parallel introduction of a viable, available fuel delivery system and sufficient numbers of vehicles to buy fuel to justify expansion of the fueling infrastructure. Viability of the fuel structure means widespread, affordable hydrogen which can return a reasonable profit to the fuel provider, while

  12. Guidance and Control Software Project Data - Volume 3: Verification Documents

    NASA Technical Reports Server (NTRS)

    Hayhurst, Kelly J. (Editor)

    2008-01-01

    The Guidance and Control Software (GCS) project was the last in a series of software reliability studies conducted at Langley Research Center between 1977 and 1994. The technical results of the GCS project were recorded after the experiment was completed. Some of the support documentation produced as part of the experiment, however, is serving an unexpected role far beyond its original project context. Some of the software used as part of the GCS project was developed to conform to the RTCA/DO-178B software standard, "Software Considerations in Airborne Systems and Equipment Certification," used in the civil aviation industry. That standard requires extensive documentation throughout the software development life cycle, including plans, software requirements, design and source code, verification cases and results, and configuration management and quality control data. The project documentation that includes this information is open for public scrutiny without the legal or safety implications associated with comparable data from an avionics manufacturer. This public availability has afforded an opportunity to use the GCS project documents for DO-178B training. This report provides a brief overview of the GCS project, describes the 4-volume set of documents and the role they are playing in training, and includes the verification documents from the GCS project. Volume 3 contains four appendices: A. Software Verification Cases and Procedures for the Guidance and Control Software Project; B. Software Verification Results for the Pluto Implementation of the Guidance and Control Software; C. Review Records for the Pluto Implementation of the Guidance and Control Software; and D. Test Results Logs for the Pluto Implementation of the Guidance and Control Software.

  13. Projection Operator: A Step Towards Certification of Adaptive Controllers

    NASA Technical Reports Server (NTRS)

    Larchev, Gregory V.; Campbell, Stefan F.; Kaneshige, John T.

    2010-01-01

    One of the major barriers to wider use of adaptive controllers in commercial aviation is the lack of appropriate certification procedures. In order to be certified by the Federal Aviation Administration (FAA), an aircraft controller is expected to meet a set of guidelines on functionality and reliability while not negatively impacting other systems or safety of aircraft operations. Due to their inherent time-variant and non-linear behavior, adaptive controllers cannot be certified via the metrics used for linear conventional controllers, such as gain and phase margin. Projection Operator is a robustness augmentation technique that bounds the output of a non-linear adaptive controller while conforming to the Lyapunov stability rules. It can also be used to limit the control authority of the adaptive component so that the said control authority can be arbitrarily close to that of a linear controller. In this paper we will present the results of applying the Projection Operator to a Model-Reference Adaptive Controller (MRAC), varying the amount of control authority, and comparing controller s performance and stability characteristics with those of a linear controller. We will also show how adjusting Projection Operator parameters can make it easier for the controller to satisfy the certification guidelines by enabling a tradeoff between controller s performance and robustness.

  14. Supporting the Future Air Traffic Control Projection Process

    NASA Technical Reports Server (NTRS)

    Davison, Hayley J.; Hansman, R. John, Jr.

    2002-01-01

    In air traffic control, projecting what the air traffic situation will be over the next 30 seconds to 30 minutes is a key process in identifying conflicts that may arise so that evasive action can be taken upon discovery of these conflicts. A series of field visits in the Boston and New York terminal radar approach control (TRACON) facilities and in the oceanic air traffic control facilities in New York and Reykjavik, Iceland were conducted to investigate the projection process in two different ATC domains. The results from the site visits suggest that two types of projection are currently used in ATC tasks, depending on the type of separation minima and/or traffic restriction and information display used by the controller. As technologies improve and procedures change, care should be taken by designers to support projection through displays, automation, and procedures. It is critical to prevent time/space mismatches between interfaces and restrictions. Existing structure in traffic dynamics could be utilized to provide controllers with useful behavioral models on which to build projections. Subtle structure that the controllers are unable to internalize could be incorporated into an ATC projection aid.

  15. Validating and Improving Interrill Erosion Equations

    PubMed Central

    Zhang, Feng-Bao; Wang, Zhan-Li; Yang, Ming-Yi

    2014-01-01

    Existing interrill erosion equations based on mini-plot experiments have largely ignored the effects of slope length and plot size on interrill erosion rate. This paper describes a series of simulated rainfall experiments which were conducted according to a randomized factorial design for five slope lengths (0.4, 0.8, 1.2, 1.6, and 2 m) at a width of 0.4 m, five slope gradients (17%, 27%, 36%, 47%, and 58%), and five rainfall intensities (48, 62.4, 102, 149, and 170 mm h−1) to perform a systematic validation of existing interrill erosion equations based on mini-plots. The results indicated that the existing interrill erosion equations do not adequately describe the relationships between interrill erosion rate and its influencing factors with increasing slope length and rainfall intensity. Univariate analysis of variance showed that runoff rate, rainfall intensity, slope gradient, and slope length had significant effects on interrill erosion rate and that their interactions were significant at p = 0.01. An improved interrill erosion equation was constructed by analyzing the relationships of sediment concentration with rainfall intensity, slope length, and slope gradient. In the improved interrill erosion equation, the runoff rate and slope factor are the same as in the interrill erosion equation in the Water Erosion Prediction Project (WEPP), with the weight of rainfall intensity adjusted by an exponent of 0.22 and a slope length term added with an exponent of −0.25. Using experimental data from WEPP cropland soil field interrill erodibility experiments, it has been shown that the improved interrill erosion equation describes the relationship between interrill erosion rate and runoff rate, rainfall intensity, slope gradient, and slope length reasonably well and better than existing interrill erosion equations. PMID:24516624

  16. Validating and improving interrill erosion equations.

    PubMed

    Zhang, Feng-Bao; Wang, Zhan-Li; Yang, Ming-Yi

    2014-01-01

    Existing interrill erosion equations based on mini-plot experiments have largely ignored the effects of slope length and plot size on interrill erosion rate. This paper describes a series of simulated rainfall experiments which were conducted according to a randomized factorial design for five slope lengths (0.4, 0.8, 1.2, 1.6, and 2 m) at a width of 0.4 m, five slope gradients (17%, 27%, 36%, 47%, and 58%), and five rainfall intensities (48, 62.4, 102, 149, and 170 mm h(-1)) to perform a systematic validation of existing interrill erosion equations based on mini-plots. The results indicated that the existing interrill erosion equations do not adequately describe the relationships between interrill erosion rate and its influencing factors with increasing slope length and rainfall intensity. Univariate analysis of variance showed that runoff rate, rainfall intensity, slope gradient, and slope length had significant effects on interrill erosion rate and that their interactions were significant at p = 0.01. An improved interrill erosion equation was constructed by analyzing the relationships of sediment concentration with rainfall intensity, slope length, and slope gradient. In the improved interrill erosion equation, the runoff rate and slope factor are the same as in the interrill erosion equation in the Water Erosion Prediction Project (WEPP), with the weight of rainfall intensity adjusted by an exponent of 0.22 and a slope length term added with an exponent of -0.25. Using experimental data from WEPP cropland soil field interrill erodibility experiments, it has been shown that the improved interrill erosion equation describes the relationship between interrill erosion rate and runoff rate, rainfall intensity, slope gradient, and slope length reasonably well and better than existing interrill erosion equations.

  17. Field studies of beach cones as coastal erosion control/reversal devices for areas with significant oil and gas activities. [Annual report], February 24, 1992--February 23, 1993

    SciTech Connect

    Law, V.J.

    1993-03-15

    The primary objective of this project is to evaluate the utility of a device called the ``beach cone`` in combating coastal erosion. Seven initial sites were selected for testing beach cones in a variety of geometric configurations. Permits were obtained from the State of Louisiana and the US Army Corps of Engineers to perform the work associated with this study. Six hundred beach cones were actually installed at six of the sites in late July and early August, 1992. One of the initial sites was abandoned because it was found to be unsuitable for beach cone placement. The test sites have been observed for six months and preliminary findings indicate that beach cones accreted significant amounts of materials along the beach of a barrier island. At other test sites, accretion rates have been less dramatic but importantly, no significant additional erosion has occurred, which is a positive result. It is too soon to state the categorical success of the beach cones, but results to date are encouraging.

  18. ANG coal gasification project management control system report. [Great Plains project

    SciTech Connect

    Not Available

    1981-01-01

    Much time, money and effort has been spent in the forefront of this project for project controls. The work breakdown structure for the systems has been custom designed. The systems, both manual and computerized, have been well scrutinized and chosen by ANG to represent the most cost effective and efficient way of controlling a project the magnitude of $1.5 billion. These systems have been developed in a manner so that information can be gathered as detailed or as summarized as necessary, and in the most timely and expeditious ways.

  19. Applying Water-Level Difference Control to Central Arizona Project

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Central Arizona Project (CAP) has been supplying Colorado River water to Central Arizona for roughly 25 years. The CAP canal is operated remotely with a Supervisory Control and Data Acquisition (SCADA) System. Gate position changes are made either manually or through the use of automatic control...

  20. Overview of NASA's Thermal Control System Development for Exploration Project

    NASA Technical Reports Server (NTRS)

    Stephan, Ryan A.

    2009-01-01

    NASA s Constellation Program includes the Orion, Altair, and Lunar Surface Systems project offices. The first two elements, Orion and Altair, are manned space vehicles while the third element is broader and includes several subelements including Rovers and a Lunar Habitat. The upcoming planned missions involving these systems and vehicles include several risks and design challenges. Due to the unique thermal environment, many of these risks and challenges are associated with the vehicles thermal control system. NASA s Exploration Systems Mission Directorate (ESMD) includes the Exploration Technology Development Program (ETDP). ETDP consists of several technology development projects. The project chartered with mitigating the aforementioned risks and design challenges is the Thermal Control System Development for Exploration Project. The risks and design challenges are addressed through a rigorous technology development process that culminates with an integrated thermal control system test. The resulting hardware typically has a Technology Readiness Level (TRL) of six. This paper summarizes the development efforts being performed by the technology development project. The development efforts involve heat acquisition and heat rejection hardware including radiators, heat exchangers, and evaporators. The project has also been developing advanced phase change material heat sinks and performing assessments for thermal control system fluids. The current paper will provide an update to a similar overview paper published at last year s International Conference on Environmental Systems (ICES).

  1. Overview of NASA's Thermal Control System Development for Exploration Project

    NASA Technical Reports Server (NTRS)

    Stephan, Ryan A.

    2009-01-01

    NASA's Constellation Program includes the Orion, Altair, and Lunar Surface Systems (LSS) project offices. The first two elements, Orion and Altair, are manned space vehicles while the third element is broader and includes several subelements including Rovers and a Lunar Habitat. The upcoming planned missions involving these systems and vehicles include several risks and design challenges. Due to the unique thermal environment, many of these risks and challenges are associated with the vehicles thermal control system. NASA s Exploration Systems Mission Directorate (ESMD) includes the Exploration Technology Development Program (ETDP). ETDP consists of several technology development projects. The project chartered with mitigating the aforementioned risks and design challenges is the Thermal Control System Development for Exploration Project. The risks and design challenges are addressed through a rigorous technology development process that culminates with an integrated thermal control system test. The resulting hardware typically has a Technology Readiness Level (TRL) of approximately six. This paper summarizes the development efforts being performed by the technology development project. The development efforts involve heat acquisition and heat rejection hardware including radiators, heat exchangers, and evaporators. The project has also been developing advanced phase change material heat sinks and performing assessments for thermal control system fluids.

  2. Overview of NASA's Thermal Control Technology Development Project

    NASA Technical Reports Server (NTRS)

    Stephan, Ryan A.

    2010-01-01

    NASA?s Constellation Program included the Orion, Altair, and Lunar Surface Systems project offices. The first two elements, Orion and Altair, were planned to be manned space vehicles while the third element was much broader and included several sub-elements including Rovers and a Lunar Habitat. The planned missions involving these systems and vehicles included several risks and design challenges. Due to the unique thermal operating environment, many of these risks and challenges were associated with the vehicles? thermal control system. NASA?s Exploration Technology Development Program (ETDP) consisted of several technology development projects. The project chartered with mitigating the aforementioned thermal risks and design challenges was the Thermal Control System Development for Exploration Project. These risks and design challenges were being addressed through a rigorous technology development process that was planned to culminate with an integrated thermal control system test. Although these Constellation elements have been cancelled or significantly changed, the thermal technology development process is being continued within a new program entitled Enabling Technology Development and Demonstration (ETDD). The current paper summarizes the development efforts being performed by the technology development project. The development efforts involve heat acquisition and heat rejection hardware including radiators, heat exchangers, and evaporators. The project has also been developing advanced phase change material heat sinks and performing a material compatibility assessment for a promising thermal control system working fluid. The to-date progress and lessons-learned from these development efforts will be discussed throughout the paper.

  3. Overview of NASA's Thermal Control System Development for Exploration Project

    NASA Technical Reports Server (NTRS)

    Stephan, Ryan A.

    2010-01-01

    NASA's Constellation Program includes the Orion, Altair, and Lunar Surface Systems project offices. The first two elements, Orion and Altair, are manned space vehicles while the third element is broader and includes several sub-elements including Rovers and a Lunar Habitat. The upcoming planned missions involving these systems and vehicles include several risks and design challenges. Due to the unique thermal environment, many of these risks and challenges are associated with the vehicles' thermal control system. NASA's Exploration Systems Mission Directorate (ESMD) includes the Exploration Technology Development Program (ETDP). ETDP consists of several technology development projects. The project chartered with mitigating the aforementioned risks and design challenges is the Thermal Control System Development for Exploration Project. The risks and design challenges are addressed through a rigorous technology development process that culminates with an integrated thermal control system test. The resulting hardware typically has a Technology Readiness Level (TRL) of six. This paper summarizes the development efforts being performed by the technology development project. The development efforts involve heat acquisition and heat rejection hardware including radiators, heat exchangers, and evaporators. The project has also been developing advanced phase change material heat sinks and performing assessments for thermal control system fluids.

  4. Preparation of SLN-containing Thermoresponsive In-situ Forming Gel as a Controlled Nanoparticle Delivery System and Investigating its Rheological, Thermal and Erosion Behavior

    PubMed Central

    Dorraj, Golnar; Moghimi, Hamid Reza

    2015-01-01

    Various nanoparticles have been investigated as novel drug delivery systems, including solid lipid nanoparticles (SLNs). Due to their rapid clearance from systemic circulation, nanoparticles do not provide sustained action in most cases. Different strategies have been employed to overcome this problem. In this direction, the present study introduces erodible in-situ forming gel systems as potential vehicles for prolonged release of SLNs. SLNs were prepared by solidification of an oil-in-water microemulsion containing stearic acid, surfactants and co-surfactants. Nanoparticles were then dispersed in a thermosensitive Poloxamer 407 aqueous solution (sol) at 4 °C and their effects on gel forming ability, sol-gel transition and rheological behavior of the system were investigated over 5-50 °C. Thermal behavior of the system was investigated by differential scanning calorimetry too. Erosion rate of the gel in the presence and absence of SLN was measured by gravimetric method. Integrity of SLNs in the system was investigated by scanning electron microscopy (SEM) and particle size analysis. SLN showed particle size and zeta potential of 130 ± 1.39 nm and - 44 ± 2.1 mV respectively. Particle size analysis and SEM studies after gel erosion revealed presence of intact SLN in the hydrogel. SLN reduced erosion rate of Poloxamer gel and increased its sol-gel transition temperature from 26 to 29 °C. However, gelling kinetic did not change significantly after addition of SLN. Damping factor <1 indicated stability of the SLN-containing system. Present results indicate potential of sol-gel systems for controlled nanoparticle delivery and show that SLN affects properties of the system. PMID:25901142

  5. Building the evidence base for effective tobacco control policies: the International Tobacco Control Policy Evaluation Project (the ITC Project).

    PubMed

    Fong, G T; Cummings, K M; Shopland, D R

    2006-06-01

    The Framework Convention on Tobacco Control (FCTC) is a seminal event in tobacco control and in global health. Scientific evidence guided the creation of the FCTC, and as the treaty moves into its implementation phase, scientific evidence can be used to guide the formulation of evidence-based tobacco control policies. The International Tobacco Control Policy Evaluation Project (ITC Project) is a transdisciplinary international collaboration of tobacco control researchers who have created research studies to evaluate and understand the psychosocial and behavioural impact of FCTC policies as they are implemented in participating ITC countries, which together are inhabited by over 45% of the world's smokers. This introduction to the ITC Project supplement of Tobacco Control presents a brief outline of the ITC Project, including a summary of key findings to date. The overall conceptual model and methodology of the ITC Project--involving representative national cohort surveys created from a common conceptual model, with common methods and measures across countries--may hold promise as a useful paradigm in efforts to evaluate and understand the impact of population-based interventions in other important domains of health, such as obesity.

  6. F-15 837 IFCS Intelligent Flight Control System Project

    NASA Technical Reports Server (NTRS)

    Bosworth, John T.

    2007-01-01

    This viewgraph presentation reviews the use of Intelligent Flight Control System (IFCS) for the F-15. The goals of the project are: (1) Demonstrate Revolutionary Control Approaches that can Efficiently Optimize Aircraft Performance in both Normal and Failure Conditions (2) Advance Neural Network-Based Flight Control Technology for New Aerospace Systems Designs. The motivation for the development are to reduce the chance and skill required for survival.

  7. CLEAR LAKE BASIN 2000 PROJECT

    SciTech Connect

    LAKE COUNTY SANITATION DISTRICT

    2003-03-31

    The following is a final report for the Clear Lake Basin 2000 project. All of the major project construction work was complete and this phase generally included final details and testing. Most of the work was electrical. Erosion control activities were underway to prepare for the rainy season. System testing including pump stations, electrical and computer control systems was conducted. Most of the project focus from November onward was completing punch list items.

  8. Saliva parameters and erosive wear in adolescents.

    PubMed

    Zwier, N; Huysmans, M C D N J M; Jager, D H J; Ruben, J; Bronkhorst, E M; Truin, G J

    2013-01-01

    The aim of this study was to investigate the relationship between several parameters of saliva and erosive wear in adolescents. (Un-)stimulated saliva was collected from 88 adolescents with erosion and 49 controls (age 16 ± 1 years). Flow rate, pH and buffer capacity were determined immediately. Total protein content, carbonic anhydrase VI, amylase, albumin, calcium, phosphate, urea, sodium, chloride and potassium were measured at a later time. Unstimulated flow rate was found to be significantly lower in subjects with erosive wear (p = 0.016). The chloride concentration in unstimulated saliva was found to be significantly higher in the erosion group (p = 0.019).

  9. Controlled cooling of an electronic system based on projected conditions

    DOEpatents

    David, Milnes P.; Iyengar, Madhusudan K.; Schmidt, Roger R.

    2015-08-18

    Energy efficient control of a cooling system cooling an electronic system is provided based, in part, on projected conditions. The control includes automatically determining an adjusted control setting(s) for an adjustable cooling component(s) of the cooling system. The automatically determining is based, at least in part, on projected power consumed by the electronic system at a future time and projected temperature at the future time of a heat sink to which heat extracted is rejected. The automatically determining operates to reduce power consumption of the cooling system and/or the electronic system while ensuring that at least one targeted temperature associated with the cooling system or the electronic system is within a desired range. The automatically determining may be based, at least in part, on an experimentally obtained model(s) relating the targeted temperature and power consumption of the adjustable cooling component(s) of the cooling system.

  10. Controlled cooling of an electronic system based on projected conditions

    DOEpatents

    David, Milnes P.; Iyengar, Madhusudan K.; Schmidt, Roger R.

    2016-05-17

    Energy efficient control of a cooling system cooling an electronic system is provided based, in part, on projected conditions. The control includes automatically determining an adjusted control setting(s) for an adjustable cooling component(s) of the cooling system. The automatically determining is based, at least in part, on projected power consumed by the electronic system at a future time and projected temperature at the future time of a heat sink to which heat extracted is rejected. The automatically determining operates to reduce power consumption of the cooling system and/or the electronic system while ensuring that at least one targeted temperature associated with the cooling system or the electronic system is within a desired range. The automatically determining may be based, at least in part, on an experimentally obtained model(s) relating the targeted temperature and power consumption of the adjustable cooling component(s) of the cooling system.

  11. Rainfall profile characteristics in erosive and not-erosive events

    NASA Astrophysics Data System (ADS)

    Todisco, Francesca

    2014-05-01

    In a storm the rainfall rate shows fluctuations with showers, low rain periods or rainless periods that follow one another at short or long time intervals. The intra-storm rainfall variations and event profile have been proved to have an important influence and exert a fundamental control in many field and research areas among which in runoff generation and soil erosion (Dunkerley, 2012; Frauenfeld and Truman, 2004; Mermut et al., 1997; Parsons and Stone 2006; Ran et al, 2012; Watung et al. 1996;). In particular the possibility to incorporate into simulated rain events pre-determined intensity variations, have recently driven more investigation on the effect of further intra-storm properties on the hydrograph and on the soil loss dynamic such as the position among the rainfall of the maximum rainfall intensity and of the rainless intervals (Dunkerley, 2008, 2012; El-Jabi and Sarraf, 1991; Parsons and Stone 2006; Ran et al, 2012). The objective of this paper is to derive the statistical expressions for the time distribution of erosive and not-erosive rainfalls and to describe the rainfall factors that influence the time distribution characteristics and that characterize an erosive event compared to a not erosive event. The analysis is based on the database of the experimental site of Masse (Central Italy): event soil loss and runoff volume from bare plot and climatic data, at 5 min time interval for the 5-years period 2008-2012 (Bagarello et al., 2011, Todisco et al., 2012). A total of 228 rainfall events were used in which the rainfall exceed 1 mm, 60 of which erosive. The soil is a Typic Haplustept (Soil Survey Staff, 2006) with a silty-clay-loam texture. The runs theory (Yevjevich, 1967) were applied to the rainfall events hyetograph to select the heavier ones named storms. The sequential periods with rainfall intensity above a threshold are defined as heavy intensity in series and called runs. All the rainfall events characterized by at least one run were

  12. Management of sediment and erosion processes in boreal headwaters affected by peatland drainage

    NASA Astrophysics Data System (ADS)

    Marttila, H.; Tammela, S.; Kløve, B.

    2009-04-01

    Peatland drainage for forestry, agriculture, peat harvesting and urban infrastructure has been altered landscape in Finland. Pristine peatlands and headwaters provide important hydrological and ecological functions that can be lost after drainage. The drainage has resulted in increase of forest resources but also negative environmental effects including changes in runoffs, erosion processes, siltation and eutrophication. The changes that can occur after drainage are, however, complex and must be better understood if the negative impacts of drainage are to be reduced or prevented. Especially erosion and transport processes of organic peat sediment are not well understood (Marttila and Kløve, 2008). Methods for controlling the sediment load include erosion and transport control practices in the catchment area (Marttila and Kløve, 2009; Tammela et al. 2009). The presentation/poster will present methods and preliminary results project from Northern Finland. The issues especially covered are sediment erosion and transport and methods to restore and reduce impacts of peatland drainage in boreal headwaters. Keywords: sediment transport, erosion, peatland drainage, organic and inorganic sediment, stream and catchment restoration, management, environment References: Marttila, H. and Kløve. B. 2008. Erosion and delivery of deposited peat sediment. Water Resources Research. 44 (6). Marttila, H. Kløve. B. 2009. Retention of sediment and nutrient loads with peak runoff control. Journal of Irrigation and Drainage Engineering (in press). Tammela, S. Marttila, H. and Kløve. B. 2009. Effect and design of an underminer structure on flow distribution and local bed topography (submitted).

  13. Erosion resistant coatings

    NASA Technical Reports Server (NTRS)

    Falco, L.; Cushini, A.

    1981-01-01

    Apparatus for measuring the resistance of materials to erosion is examined and a scheme for standardization of the test parameters is described. Current materials being used for protecting aircraft parts from erosion are surveyed, their chief characteristics being given. The superior properties of urethane coatings are pointed out. The complete cycle for painting areas subject to erosion is described.

  14. Project Management Using Modern Guidance, Navigation and Control Theory

    NASA Technical Reports Server (NTRS)

    Hill, Terry R.

    2011-01-01

    Implementing guidance, navigation, and control (GN&C) theory principles and applying them to the human element of project management and control is not a new concept. As both the literature on the subject and the real-world applications are neither readily available nor comprehensive with regard to how such principles might be applied, this paper has been written to educate the project manager on the "laws of physics" of his or her project (not to teach a GN&C engineer how to become a project manager) and to provide an intuitive, mathematical explanation as to the control and behavior of projects. This paper will also address how the fundamental principles of modern GN&C were applied to the National Aeronautics and Space Administration's (NASA) Constellation Program (CxP) space suit project, ensuring the project was managed within cost, schedule, and budget. A project that is akin to a physical system can be modeled and managed using the same over arching principles of GN&C that would be used if that project were a complex vehicle, a complex system(s), or complex software with time-varying processes (at times nonlinear) containing multiple data inputs of varying accuracy and a range of operating points. The classic GN&C theory approach could thus be applied to small, well-defined projects; yet when working with larger, multiyear projects necessitating multiple organizational structures, numerous external influences, and a multitude of diverse resources, modern GN&C principles are required to model and manage the project. The fundamental principles of a GN&C system incorporate these basic concepts: State, Behavior, Feedback Control, Navigation, Guidance and Planning Logic systems. The State of a system defines the aspects of the system that can change over time; e.g., position, velocity, acceleration, coordinate-based attitude, and temperature, etc. The Behavior of the system focuses more on what changes are possible within the system; this is denoted in the state

  15. Field studies of beach cones as coastal erosion control/reversal devices for areas with significant oil and gas activities. Final report, February 24, 1992--September 18, 1995

    SciTech Connect

    Law, V.J.

    1995-09-18

    The primary objective of this project was to evaluate the utility of a device called the {open_quotes}beach cone{close_quotes} in combating coastal erosion. Seven initial sites were selected for testing beach cones in a variety of geometric configurations. Permits were obtained from the State of Louisiana and the U.S. Army Corps of Engineers to perform the work associated with this study. Six hundred beach cones were actually installed at six of the sites in late July and early August, 1992. Findings indicate that beach cones accreted significant amounts of materials along the beach of a barrier island, and they might have been instrumental in repairing an approximately 200 meter gap in the island. At the eighth installation the amount of accreted material was measured by surveys to be 2200 cubic meters (2900 cubic yards) in February of 1993, when the cones were found to have been completely covered by the material. At other test sites, accretion rates have been less dramatic but importantly, no significant additional erosion has occurred, which is a positive result. The cost of sediment accretion using beach cones was found to be about $13.72 per cubic yard, which would be much lower if the cones were mass produced (on the order of $3.00 per cubic yard). The survival of the cones through the fringes of Hurricane Andrew indicates that they can be anchored sufficiently to survive significant storms. The measurements of the cones settling rates indicate that this effect is not significant enough to hinder their effectiveness. A subcontract to Xavier University to assess the ecological quality of the experimental sites involved the study of the biogeochemical cycle of trace metals. The highest concentration of heavy metals were near a fishing camp while the lowest levels were in the beach sand of a barrier island. This suggests that the metals do not occur naturally in these areas, but have been placed in the sediments by man`s activities.

  16. Field studies of beach cones as coastal erosion control/reversal devices for areas with significant oil and gas activities. Annual report, February 24, 1993--February 23, 1994

    SciTech Connect

    Law, V.J.

    1994-07-07

    The primary objective of this project was to evaluate the utility of a device called the ``beach cone`` in combating coastal erosion. Seven initial sites were selected for testing beach cones in a variety of geometric configurations, and six sites were actually used. Six hundred beach cones were installed at the six sites in late July and early August, 1992. An additional 109 cones were installed at an eighth site in December of 1992. Findings indicate that beach cones accreted significant amounts of materials along the beach of a barrier island. At the eighth installation the amount of accreted material was measured by surveys to be 2200 cubic meters (2900 cubic yards) in February of 1993, when the cones were found to have been completely covered by the material. The average increase in elevation was about 7 inches (0. 18 in) with a maximum buildup of 3 ft. (I in). At other test sites, accretion rates have been less dramatic but importantly, no significant additional erosion has occurred, which is a positive result. The cost of sediment accretion using beach cones was found to be about $13.72 per cubic yard of sand or approximately $500,000 per mile of beach, which would be much lower if the cones were mass produced. The survival of the cones through the fringes of Hurricane Andrew indicates that they can be anchored sufficiently to survive significant storms. The measurements of the cones settling rates indicate that this effect is negligible, does not hinder their effectiveness. We do not yet have sufficient data to state the categorical success of the beach cones, but results to date are encouraging.

  17. Overview of NASA's Thermal Control System Development for Exploration Project

    NASA Technical Reports Server (NTRS)

    Stephan, Ryan A.

    2011-01-01

    The now-cancelled Constellation Program included the Orion, Altair, and Lunar Surface Systems project offices. The first two elements, Orion and Altair, were planned to be manned space vehicles while the third element was much more diverse and included several sub-elements. Among other things, these sub-elements were Rovers and a Lunar Habitat. The planned missions involving these systems and vehicles included several risks and design challenges. Due to the unique thermal operating environment, many of these risks and challenges were associated with the vehicles thermal control system. NASA s Exploration Technology Development Program (ETDP) consisted of various technology development projects. The project chartered with mitigating the aforementioned thermal risks and design challenges was the Thermal Control System Development for Exploration Project. These risks and design challenges were being addressed through a rigorous technology development process that was planned to culminate with an integrated thermal control system test. Although the technologies being developed were originally aimed towards mitigating specific Constellation risks, the technology development process is being continued within a new program. This continued effort is justified by the fact that many of the technologies are generically applicable to future spacecraft thermal control systems. The current paper summarizes the development efforts being performed by the technology development project. The development efforts involve heat acquisition and heat rejection hardware including radiators, heat exchangers, and evaporators. The project has also been developing advanced phase change material heat sinks and performing a material compatibility assessment for a promising thermal control system working fluid. The to-date progress and lessons-learned from these development efforts will be discussed throughout the paper.

  18. Spillway and foundation erosion: Predicting erosion threshold

    SciTech Connect

    Annandale, G.W.; Wittler, R.J.; Mefford, B.W.

    1995-12-31

    This paper summarizes the method that will be used by the Bureau of Reclamation to investigate scour of spillways and dam foundations, and to develop a numerical model to compute the same. In what follows the basis of a unique relationship between the erosive power of water and the ability of earth materials to resist erosion, known as the Erodibility Index Method, is presented. The paper also provides a description of the approach that will be used by the numerical model to calculate the erosive power of plunging, aerated jets. The complimentary paper, Wittler (1995), describes the approach that will be used to investigate the extent of scour of spillways and dam foundations.

  19. Projection learning algorithm for threshold - controlled neural networks

    SciTech Connect

    Reznik, A.M.

    1995-03-01

    The projection learning algorithm proposed in [1, 2] and further developed in [3] substantially improves the efficiency of memorizing information and accelerates the learning process in neural networks. This algorithm is compatible with the completely connected neural network architecture (the Hopfield network [4]), but its application to other networks involves a number of difficulties. The main difficulties include constraints on interconnection structure and the need to eliminate the state uncertainty of latent neurons if such are present in the network. Despite the encouraging preliminary results of [3], further extension of the applications of the projection algorithm therefore remains problematic. In this paper, which is a continuation of the work begun in [3], we consider threshold-controlled neural networks. Networks of this type are quite common. They represent the receptor neuron layers in some neurocomputer designs. A similar structure is observed in the lower divisions of biological sensory systems [5]. In multilayer projection neural networks with lateral interconnections, the neuron layers or parts of these layers may also have the structure of a threshold-controlled completely connected network. Here the thresholds are the potentials delivered through the projection connections from other parts of the network. The extension of the projection algorithm to the class of threshold-controlled networks may accordingly prove to be useful both for extending its technical applications and for better understanding of the operation of the nervous system in living organisms.

  20. Dental erosion, summary.

    PubMed

    ten Cate, J M; Imfeld, T

    1996-04-01

    Although reports on dental erosion have always appeared in the dental literature, there is currently a growing interest among researchers and clinicians. Potential risk factors for dental erosion are changed lifestyle and eating patterns, with increased consumption of acidic foods and beverages. Various gastrointestinal and eating disorders expose the dentition to frequent contacts with very acidic gastric content, which may lead to erosion. Whether these factors indeed lead, on a population scale, to a higher prevalence and incidence of erosion is yet to be established. This article summarizes the different aspects of the prevalence, pathology, etiology, assessment, prevention and treatment of dental erosion, and concludes with recommendations for future research.

  1. SOLERAS - Solar Controlled Environment Agriculture Project. Final report, Volume 1. Project summary

    SciTech Connect

    Not Available

    1985-12-30

    A summary of the Solar Controlled Environment Agriculture Project is presented. The design of the greenhouses include transparent double pane glass roof with channels for fluid between the panes, inner pane tinted and double pane extruded acrylic aluminized mylar shade and diffuser. Solar energy technologies provide power for water desalination, for pumping irrigation water, and for cooling and heating the controlled environment space so that crops can grow in arid lands. The project is a joint effort between the United States and Saudi Arabia. (BCS)

  2. Controlled release from hydrogel-based solid matrices. A model accounting for water up-take, swelling and erosion.

    PubMed

    Lamberti, Gaetano; Galdi, Ivan; Barba, Anna Angela

    2011-04-04

    Design and realization of drug delivery systems based on polymer matrices could be greatly improved by modeling the phenomena which take place after the systems administration. Availability of a reliable mathematical model, able to predict the release kinetic from drug delivery systems, could actually replace the resource-consuming trial-and-error procedures usually followed in the manufacture of these latter. In this work, the complex problem of drug release from polymer (HPMC) based matrices systems was faced. The phenomena, previously observed and experimentally quantified, of water up-take, system swelling and erosion, and drug release were here described by transient mass balances with diffusion. The resulting set of differential equations was solved by using finite element methods. Two different systems were investigated: cylindrical matrices in which the transport phenomena were allowed only by lateral surfaces ("radial" case), and cylindrical matrices with the overall surface exposed to the solvent ("overall" case). A code able to describe quantitatively all the observed phenomena has been obtained.

  3. Temporal and spatial climatic controls on Holocene fire-related erosion and sedimentation, Jemez Mountains, New Mexico

    NASA Astrophysics Data System (ADS)

    Fitch, Erin P.; Meyer, Grant A.

    2016-01-01

    In the Jemez Mountains, tree-ring data indicate that low-severity fires characterized the 400 yr before Euro-American settlement, and that subsequent fire suppression promoted denser forests, recent severe fires, and erosion. Over longer timescales, climate change may alter fire regimes; thus, we used fire-related alluvial deposits to assess the timing of moderate- to high-severity fires, their geomorphic impact, and relation to climate over the last 4000 yr. Fire-related sedimentation does not clearly follow millennial-scale climatic changes, but probability peaks commonly correspond with severe drought, e.g., within the interval 1700-1400 cal yr BP, and ca. 650 and ca. 410 cal yr BP. The latter episodes were preceded by prolonged wet intervals that could promote dense stands. Estimated recurrence intervals for fire-related sedimentation are 250-400 yr. Climatic differences with aspect influenced Holocene post-fire response: fire-related deposits constitute 77% of fan sediments from north-facing basins but only 39% of deposits from drier southerly aspects. With sparser vegetation and exposed bedrock, south aspects can generate runoff and sediment when unburned, whereas soil-mantled north aspects produce minor sediment unless severely burned. Recent channel incision appears unprecedented over the last 2300 yr, suggesting that fuel loading and extreme drought produced an anomalously severe burn in 2002.

  4. Advanced Guidance and Control Project for Reusable Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Hanson, John M.

    2000-01-01

    The goals of this project are to significantly reduce the time and cost associated with guidance and control design for reusable launch vehicles, and to increase their safety and reliability. Success will lead to reduced cycle times during vehicle design and to reduced costs associated with flying to new orbits, with new payloads, and with modified vehicles. Success will also lead to more robustness to unforeseen circumstances in flight thereby enhancing safety and reducing risk. There are many guidance and control methods available that hold some promise for improvement in the desired areas. Investigators are developing a representative set of independent guidance and control methods for this project. These methods are being incorporated into a high-fidelity off is being conducted across a broad range of flight requirements. The guidance and control methods that perform the best will have demonstrated the desired qualities.

  5. [Essential issues for project management and quality control in the national schistosomiasis control programme of China].

    PubMed

    Zhou, Xiao-Nong; Li, Shi-Zhu

    2012-08-01

    Based on theoretic management and quality control of the project, this paper summarizes the 3 major management modes in the national schistosomiasis control programme of China, and the health system management mechanisms under the guidance of national legislation, national programme and national standard and regulation. It is revealed that scientific assessment and assurance of the quality of each control programme is one of the highlighted concerns in the management mode of schistosomiasis control in China after a case study on mollusciciding project. Therefore, it is recommended that the actions, including management of every step in the project management of schistosomiasis control, formulation of operation procedure for each control programme and standardization of the working flow for professional staff, are not only a prerequistite to achievment-based evaluation, but also the key to ensure the quality of every control intervention and present the actual control effect.

  6. DESCHUTES PROJECT – WICKIUP DAM, CONTROL TOWER COMPLETE TO ELEVATION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DESCHUTES PROJECT – WICKIUP DAM, CONTROL TOWER COMPLETE TO ELEVATION 4348.5 WITH TEMPORARY ROOF. BURNING OPERATIONS ON RESERVOIR CLEARING IN THE DISTANCE. Photocopy of historic photographs (original photograph on file at National Archives, Rocky Mountain Region, Denver, CO). Unknown USBR Photographer, August 31, 1943 - Wickiup Dam, Deschutes River, La Pine, Deschutes County, OR

  7. Relationship of runoff, erosion and sediment yield to weather types in the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Nadal-Romero, E.; González-Hidalgo, J. C.; Cortesi, N.; Desir, G.; Gómez, J. A.; Lasanta, T.; Lucía, A.; Marín, C.; Martínez-Murillo, J. F.; Pacheco, E.; Rodríguez-Blanco, M. L.; Romero Díaz, A.; Ruiz-Sinoga, J. D.; Taguas, E. V.; Taboada-Castro, M. M.; Taboada-Castro, M. T.; Úbeda, X.; Zabaleta, A.

    2015-01-01

    Precipitation has been recognized as one of the main factors driving soil erosion and sediment yield (SY), and its spatial and temporal variability is recognized as one of the main reasons for spatial and temporal analyses of soil erosion variability. The weather types (WTs) approach classifies the continuum of atmospheric circulation into a small number of categories or types and has been proven a good indicator of the spatial and temporal variability of precipitation. Thus, the main objective of this study is to analyze the relationship between WTs, runoff, soil erosion (measured in plots), and sediment yield (measured in catchments) in different areas of the Iberian Peninsula (IP) with the aim of detecting spatial variations in these relationships. To this end, hydrological and sediment information covering the IP from several Spanish research teams has been combined, and related with daily WTs estimated by using the NMC/NCAR 40-Year Reanalysis Project. The results show that, in general, a few WTs (particularly westerly, southwesterly and cyclonic) provide the largest amounts of precipitation; and southwesterly, northwesterly and westerly WTs play an important role in runoff generation, erosion and sediment yield as they coincide with the wettest WTs. However, this study highlights the spatial variability of erosion and sediment yield in the IP according to WT, differentiating (1) areas under the influence of north and/or north-westerly flows (the north coast of Cantabria and inland central areas), (2) areas under the influence of westerly, southwesterly and cyclonic WTs (western and southwestern IP), (3) areas in which erosion and sediment yield are controlled by easterly flows (Mediterranean coastland), and (4) lastly, a transitional zone in the inland northeast Ebro catchment, where we detected a high variability in the effects of WTs on erosion. Overall results suggest that the use of WTs derived from observed atmospheric pressure patterns could be a useful

  8. A geometric approach to quantum control in projective hilbert spaces

    NASA Astrophysics Data System (ADS)

    Pastorello, Davide

    2017-02-01

    A quantum theory in a finite-dimensional Hilbert space can be formulated as a proper geometric Hamiltonian theory as explained in [2, 3, 7, 9]. From this point of view a quantum system can be described within a classical-like framework where quantum dynamics is represented by a Hamiltonian flow in the phase space given by a projective Hilbert space. This paper is devoted to investigating how the notion of an accessibility algebra from classical control theory can be applied within the geometric Hamiltonian formulation of quantum mechanics to study controllability of a quantum system. A new characterization of quantum controllability in terms of Killing vector fields w.r.t. the Fubini-Study metric on projective space is also discussed.

  9. Education and the Professionalization of Nursing: Non-Collective Action and the Erosion of Labour-Market Control.

    ERIC Educational Resources Information Center

    Humphreys, John

    2000-01-01

    Between 1984-1989, following establishment of the United Kingdom Central Council for Nursing, Midwifery and Health Visiting, a reform-oriented, noncollective professional project emerged that marooned 30 percent of the nursing work force in an obsolescent occupational group. UKCC eroded nursing's labor-market position with the National Health…

  10. CE IGCC repowering project: Controls & instrumentation. Topical report, June 1993

    SciTech Connect

    Not Available

    1993-12-01

    The IGCC Control System is used to provide operator interface and controls for manual and auto operation of the IGCC Repowering Project Located at Springfield, Illinois. A Distributed Control System (DCS) is provided for analog (process control) loop functions and to provide the operator interface. A Data Acquisition System (DAS) is provided for gathering performance data and optimization. Programmable Logic Controllers will be provided for the following digital control systems: (a) GSSS (Gasifier Supervisory Safety System) including pulverized coal handling and char handling; (b) Coal Pulverization System; (c) HRSG (Heat Recovery Steam Generation); (d) Hot Gas Cleanup System; (e) Steam Turbine; and (f) Combined Cycle Operation. In general all systems are provided for auto/manual cascade operation; upstream equipment is interlocked to be proven in service operation and/or valve position before downstream equipment may operate.

  11. Version control friendly project management system for FPGA designs

    NASA Astrophysics Data System (ADS)

    Zabołotny, Wojciech M.

    2016-09-01

    In complex FPGA designs, usage of version control system is a necessity. It is especially important in the case of designs developed by many developers or even by many teams. The standard development mode, however, offered by most FPGA vendors is the GUI based project mode. It is very convenient for a single developer, who can easily experiment with project settings, browse and modify the sources hierarchy, compile and test the design. Unfortunately, the project configuration is stored in files which are not suited for use with Version Control System (VCS). Another important problem in big FPGA designs is reuse of IP cores. Even though there are standard solutions like IEEE 1685-2014, they suffer from some limitations particularly significant for complex systems (e.g. only simple types are allowed for IP-core ports, it is not possible to use parametrized instances of IP-cores). Additionally, the overhead associated with packaging of IP-cores is significant and not justified for simple reusable blocks. This paper presents a system aimed at storing the whole design in a VCS oriented form. The hierarchy of sources is described with textual "extended project (EPRJ) files" which are fully controlled by the user and may also be put in a VCS. The IP blocks may be easily added to the project just by including the accompanying EPRJ file. Both absolute and relative file paths may be used which allows the flexible structure of directories. The sources of locally developed IP blocks may be stored in directories located inside the main source tree, while sources of independently developed blocks, using separate VCS repositories, may be located outside that tree. The environment allows splitting the design into smaller parts, which are synthesized independently. That reduces the time needed to recompile the whole design if only a few blocks are modified. The system creates the standard project, which can be used for convenient interactive work with the design. After the

  12. The management submodel of the Wind Erosion Prediction System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Wind Erosion Prediction System (WEPS) is a process-based, daily time-step, computer model that predicts soil erosion via simulation of the physical processes controlling wind erosion. WEPS is comprised of several individual modules (submodels) that reflect different sets of physical processes, ...

  13. Project Management Using Modern Guidance, Navigation and Control Theory

    NASA Technical Reports Server (NTRS)

    Hill, Terry

    2010-01-01

    The idea of control theory and its application to project management is not new, however literature on the topic and real-world applications is not as readily available and comprehensive in how all the principals of Guidance, Navigation and Control (GN&C) apply. This paper will address how the fundamental principals of modern GN&C Theory have been applied to NASA's Constellation Space Suit project and the results in the ability to manage the project within cost, schedule and budget. A s with physical systems, projects can be modeled and managed with the same guiding principles of GN&C as if it were a complex vehicle, system or software with time-varying processes, at times non-linear responses, multiple data inputs of varying accuracy and a range of operating points. With such systems the classic approach could be applied to small and well-defined projects; however with larger, multi-year projects involving multiple organizational structures, external influences and a multitude of diverse resources, then modern control theory is required to model and control the project. The fundamental principals of G N&C stated that a system is comprised of these basic core concepts: State, Behavior, Control system, Navigation system, Guidance and Planning Logic, Feedback systems. The state of a system is a definition of the aspects of the dynamics of the system that can change, such as position, velocity, acceleration, coordinate-based attitude, temperature, etc. The behavior of the system is more of what changes are possible rather than what can change, which is captured in the state of the system. The behavior of a system is captured in the system modeling and if properly done, will aid in accurate system performance prediction in the future. The Control system understands the state and behavior of the system and feedback systems to adjust the control inputs into the system. The Navigation system takes the multiple data inputs and based upon a priori knowledge of the input

  14. Experiential learning in control systems laboratories and engineering project management

    NASA Astrophysics Data System (ADS)

    Reck, Rebecca Marie

    2015, a panel of 40 control systems faculty members, from a variety of institutions, completed a multi-round Delphi survey in order to bring them toward consensus on the common aspects of their laboratories. The following winter, 45 additional faculty members and practitioners from the control systems community completed a follow-up survey to gather feedback on the results of the Delphi survey. During the Delphi study, the panelists identified 15 laboratory objectives, 26 concepts, and 15 components that were common in their laboratories. Then in both the Delphi survey and follow-up survey each participant rated the importance of each of these items. While the average ratings differed slightly between the two groups, the order of each set of items was compared with two different tests and the order was found to be similar. Some of the common and important learning objectives include connecting theory to what is implemented and observed in the laboratory, designing controllers, and modeling and simulating systems. The most common component in both groups was Math-Works software. Some of the common concepts include block diagrams, stability, and PID control. Defining common aspects of undergraduate control systems laboratories enables common development, detailed comparisons, and simplified adaptation of equipment and experiments between campuses and programs. Throughout an undergraduate program in engineering, there are multiple opportunities for hands-on laboratory experiences that are related to course content. However, a similarly immersive experience for project management graduate students is harder to incorporate for all students in a course at once. This study explores an experiential learning opportunity for graduate students in engineering management or project management programs. The project management students enroll in a project management course. Undergraduate students interested in working on a project with a real customer enroll in a different projects

  15. Erosion and Wind Deposition

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 22 April 2003

    Streamlined buttes and mesas are left as remnants of an erosive wind that has carried away sediments and even the rim of a small crater. Two wind directions are apparent in the buttes and mesas that cross each other at 90 degrees. Small dark dunes wind their way between the remnant towers, indicating that the work of the wind is an ongoing process.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

    Image information: VIS instrument. Latitude 5.3, Longitude 350.1 East (9.9 West). 19 meter/pixel resolution.

  16. Process identification of soil erosion in steep mountain regions

    NASA Astrophysics Data System (ADS)

    Konz, N.; Baenninger, D.; Konz, M.; Nearing, M.; Alewell, C.

    2010-04-01

    Mountainous soil erosion processes were investigated in the Urseren Valley (Central Switzerland) by means of measurements and simulations. The quantification of soil erosion was performed on hill slope scale (2·20 m) for three different land use types: hayfields, pastures with dwarf shrubs and pastures without dwarf shrubs with three replicates each. Erosion rates during growing season were measured with sediment traps between June 2006 and November 2007. Long-term soil erosion rates were estimated based on Cs- 137 redistribution. In addition, soil moisture and surface flow were recorded during the growing season in the field and compared to model output. We chose the WEPP model (Water Erosion Prediction Project) to simulate soil erosion during the growing season. Model parameters were determined in the field (slope, plant species, fractional vegetation cover, initial saturation level), by laboratory analyses (grain size, organic matter) and by literature study. The WEPP model simulates sheet erosion processes (interrill and splash erosion processes, please note that no rill erosion occurs at our sites). Model output resulted in considerable smaller values than the measured erosion rates with sediment traps for the same period. We attribute the differences to observed random gravity driven erosion of soil conglomerates. The Cs-137 measurements deliver substantially higher mean annual erosion rates, which are most likely connected to snow cover related processes such as snow gliding and avalanche activities.

  17. Erosion of dust aggregates

    NASA Astrophysics Data System (ADS)

    Seizinger, A.; Krijt, S.; Kley, W.

    2013-12-01

    Aims: The aim of this work is to gain a deeper insight into how much different aggregate types are affected by erosion. Especially, it is important to study the influence of the velocity of the impacting projectiles. We also want to provide models for dust growth in protoplanetary disks with simple recipes to account for erosion effects. Methods: To study the erosion of dust aggregates we employed a molecular dynamics approach that features a detailed micro-physical model of the interaction of spherical grains. For the first time, the model has been extended by introducing a new visco-elastic damping force, which requires a proper calibration. Afterwards, different sample generation methods were used to cover a wide range of aggregate types. Results: The visco-elastic damping force introduced in this work turns out to be crucial to reproduce results obtained from laboratory experiments. After proper calibration, we find that erosion occurs for impact velocities of 5 ms-1 and above. Though fractal aggregates as formed during the first growth phase are most susceptible to erosion, we observe erosion of aggregates with rather compact surfaces as well. Conclusions: We find that bombarding a larger target aggregate with small projectiles results in erosion for impact velocities as low as a few ms-1. More compact aggregates suffer less from erosion. With increasing projectile size the transition from accretion to erosion is shifted to higher velocities. This allows larger bodies to grow through high velocity collisions with smaller aggregates.

  18. [Discussion on water conservancy projects and schistosomiasis control in Poyang Lake area].

    PubMed

    Liu, Dao-Nan

    2013-02-01

    According to the schistosomiasis endemic situation in the Poyang Lake area, this paper analyzes the relationship between the water conservancy projects and schistosomiasis control, and reviews and discusses the effects of the Water Level Control Project of Poyang Lake, the Lake Dike Slope Hardening Project, and the Lifting Delta and Descending Beach Project on Oncomelania snail control.

  19. 77 FR 3754 - Boise Project Board of Control; Notice of Application Accepted for Filing, Soliciting Comments...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-25

    ... Energy Regulatory Commission Boise Project Board of Control; Notice of Application Accepted for Filing..., 2011. d. Applicant: Boise Project Board of Control. e. Name of Project: Fargo Drop No. 1 Hydroelectric.... Applicant Contact: Paul Deveau, Manager, Boise Project Board of Control, 2465 Overland Road, Boise, ID...

  20. Controlled Hydrogen Fleet and Infrastructure Demonstration and Validation Project

    SciTech Connect

    Stottler, Gary

    2012-02-08

    General Motors, LLC and energy partner Shell Hydrogen, LLC, deployed a system of hydrogen fuel cell electric vehicles integrated with a hydrogen fueling station infrastructure to operate under real world conditions as part of the U.S. Department of Energy's Controlled Hydrogen Fleet and Infrastructure Validation and Demonstration Project. This technical report documents the performance and describes the learnings from progressive generations of vehicle fuel cell system technology and multiple approaches to hydrogen generation and delivery for vehicle fueling.

  1. Soil Erosion Protection Potential of Young Paulownia Plantation

    NASA Astrophysics Data System (ADS)

    Stepchich, Avgusta; Djodjov, Christo

    2014-05-01

    Soil erosion is removal of soil and rock particles by water, wind, ice and gravity. It is widely recognized as a global soil threat. Soils impacted by different forms of erosion cover large areas around the world. While landscape, soil and climate conditions trigger soil erosion processes, the vegetation cover reduces the soil erosion risk. About 60 % of the area of agricultural land in Bulgaria is under erosion risk, which necessitates implementation of series of measures for soil erosion control. The aim of this study is to determine the erosion protection potential and the loss of soil nutrients of young Paulownia plantation. Field experiments have been set up under unirrigated conditions at the experimental field for soil erosion studies of the N. Poushkarov Institute of Soil Science, Agrotechnology and Plant Protection near Suhodol. The local soils are Chromic Luvisols, moderately eroded. The altitude is 750 m and the slope gradient is 80. The experiment consists of four field plots for soil erosion studies, three of which planted with Paulownia Bellissima and a reference one with bare soil. The plants have been planted at a distance of 2 m between adjacent rows and 1 m between each two plants within the row. The size of each field plot is 32 m2 (4 m width and 8 m length). The plots are equipped with containers for collecting the surface runoff caused by erosive rainfall events. Biometrics, including the root-striking of the plants, their growth in height, foliage cover (projection) and stem diameter, was studied from May 13th to October 21st. The data reported cover the results from the studies during the first vegetation period after planting in the Spring of 2013. During the year four erosive rainfalls were observed with a total amount of 79.2 mm, resulting to a total amount of soil loss of 772 kg/ha from a planted plot and 551 kg/ha from bear soil. The total surface runoff is 156.7 m3/ha from planted plot and 153.1 m3/ha from bare soil. The total losses of

  2. NIF Projects Controls and Information Systems Software Quality Assurance Plan

    SciTech Connect

    Fishler, B

    2011-03-18

    Quality achievement for the National Ignition Facility (NIF) and the National Ignition Campaign (NIC) is the responsibility of the NIF Projects line organization as described in the NIF and Photon Science Directorate Quality Assurance Plan (NIF QA Plan). This Software Quality Assurance Plan (SQAP) is subordinate to the NIF QA Plan and establishes quality assurance (QA) activities for the software subsystems within Controls and Information Systems (CIS). This SQAP implements an activity level software quality assurance plan for NIF Projects as required by the LLNL Institutional Software Quality Assurance Program (ISQAP). Planned QA activities help achieve, assess, and maintain appropriate quality of software developed and/or acquired for control systems, shot data systems, laser performance modeling systems, business applications, industrial control and safety systems, and information technology systems. The objective of this SQAP is to ensure that appropriate controls are developed and implemented for management planning, work execution, and quality assessment of the CIS organization's software activities. The CIS line organization places special QA emphasis on rigorous configuration control, change management, testing, and issue tracking to help achieve its quality goals.

  3. Geomorphic considerations for erosion prediction

    USGS Publications Warehouse

    Osterkamp, W.R.; Toy, T.J.

    1997-01-01

    Current soil-erosion prediction technology addresses processes of rainsplash, overland-flow sediment transport, and rill erosion in small watersheds. The effects of factors determining sediment yield from larger-scale drainage basins, in which sediment movement is controlled by the combined small-scale processes and a complex set of channel and other basin-scale sediment-delivery processes, such as soil creep, bioturbation, and accelerated erosion due to denudation of vegetation, have been poorly evaluated. General suggestions are provided for the development of erosion-prediction technology at the geomorphic or drainage-basin scale based on the separation of sediment-yield data for channel and geomorphic processes from those of field-scale soil loss. An emerging technology must consider: (1) the effects on sediment yield of climate, geology and soils, topography, biotic interactions with other soil processes, and land-use practices; (2) all processes of sediment delivery to a channel system; and (3) the general tendency in most drainage basins for progressively greater sediment storage in the downstream direction.

  4. Introduction to tillage erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tillage as a source of erosion Tillage erosion is the downslope movement of soil by tillage. During tillage, soil is lifted and gravity moves soil downslope. Soil movement by tillage increases with slope steepness. However, net soil transport by tillage is determined by the change in slope. Soil mov...

  5. Saliva and dental erosion

    PubMed Central

    BUZALAF, Marília Afonso Rabelo; HANNAS, Angélicas Reis; KATO, Melissa Thiemi

    2012-01-01

    Dental erosion is a multifactorial condition. The consideration of chemical, biological and behavioral factors is fundamental for its prevention and therapy. Among the biological factors, saliva is one of the most important parameters in the protection against erosive wear. Objective This review discusses the role of salivary factors on the development of dental erosion. Material and Methods A search was undertaken on MEDLINE website for papers from 1969 to 2010. The keywords used in the research were "saliva", "acquired pellicle", "salivary flow", "salivary buffering capacity" and "dental erosion". Inclusion of studies, data extraction and quality assessment were undertaken independently and in duplicate by two members of the review team. Disagreements were solved by discussion and consensus or by a third party. Results Several characteristics and properties of saliva play an important role in dental erosion. Salivary clearance gradually eliminates the acids through swallowing and saliva presents buffering capacity causing neutralization and buffering of dietary acids. Salivary flow allows dilution of the acids. In addition, saliva is supersaturated with respect to tooth mineral, providing calcium, phosphate and fluoride necessary for remineralization after an erosive challenge. Furthermore, many proteins present in saliva and acquired pellicle play an important role in dental erosion. Conclusions Saliva is the most important biological factor affecting the progression of dental erosion. Knowledge of its components and properties involved in this protective role can drive the development of preventive measures targeting to enhance its known beneficial effects. PMID:23138733

  6. Post-fire Wind Erosion in a Semiarid Shrub Steppe

    NASA Astrophysics Data System (ADS)

    Glenn, N.; Sankey, J.; Germino, M.

    2007-12-01

    The objective of this project is to determine and describe the effects of fire on the potential for soil erosion by wind in a semiarid shrub steppe in southeastern Idaho. We apply a previously developed method for determining the threshold wind speed (critical threshold) required to initiate saltation of soil particles at several sampling locations within wildfires that burned in summers 2006 and 2007. Sampling locations have data collection stations with anemometers, a piezoelectric sensor mounted at 5 cm above the ground surface that records impacts from saltating soil particles, temperature and relative humidity sensors mounted at ground level, soil moisture sensors, and soil erosion bridges. Analysis is intended to identify key controlling variables of post- wildfire eolian transport with the intention of continued monitoring over longer time periods with the incorporation of LiDAR data for surface characterization. Initial field results indicate substantial differences in wind erosion potential between burned and unburned sites. Saltation activity is greater and more frequently detected at the burned sites in comparison to the unburned sites. Comparison between the burned sites indicates periods of similar saltation activity and threshold wind speeds. Comparison also shows periods when saltation is detected at one burned site but not the other, and periods when greater wind speeds are required at one burned site to initiate saltation. This suggests that within-burn variability exists in wind erosion potential and requires more complete characterization to accurately model and predict post-fire eolian transport. In parallel to the field-based research, we are developing remote sensing techniques to characterize the soil surface and vegetation communities at a scale appropriate for wind erosion modeling. These techniques include hyperspectral and LiDAR analysis of the soil surface and structural information of the vegetation. Soil and vegetation surface

  7. The Large Synoptic Survey Telescope project management control system

    NASA Astrophysics Data System (ADS)

    Kantor, Jeffrey P.

    2012-09-01

    The Large Synoptic Survey Telescope (LSST) program is jointly funded by the NSF, the DOE, and private institutions and donors. From an NSF funding standpoint, the LSST is a Major Research Equipment and Facilities (MREFC) project. The NSF funding process requires proposals and D&D reviews to include activity-based budgets and schedules; documented basis of estimates; risk-based contingency analysis; cost escalation and categorization. "Out-of-the box," the commercial tool Primavera P6 contains approximately 90% of the planning and estimating capability needed to satisfy R&D phase requirements, and it is customizable/configurable for remainder with relatively little effort. We describe the customization/configuration and use of Primavera for the LSST Project Management Control System (PMCS), assess our experience to date, and describe future directions. Examples in this paper are drawn from the LSST Data Management System (DMS), which is one of three main subsystems of the LSST and is funded by the NSF. By astronomy standards the LSST DMS is a large data management project, processing and archiving over 70 petabyes of image data, producing over 20 petabytes of catalogs annually, and generating 2 million transient alerts per night. Over the 6-year construction and commissioning phase, the DM project is estimated to require 600,000 hours of engineering effort. In total, the DMS cost is approximately 60% hardware/system software and 40% labor.

  8. Greenridge Multi-Pollutant Control Project Preliminary Public Design Report

    SciTech Connect

    Connell, Daniel P

    2009-01-12

    The Greenidge Multi-Pollutant Control Project is being conducted as part of the U.S. Department of Energy's Power Plant Improvement Initiative to demonstrate an innovative combination of air pollution control technologies that can cost-effectively reduce emissions of SO{sub 2}, NO{sub x}, Hg, acid gases (SO{sub 3}, HCl, and HF), and particulate matter from smaller coal-fired electrical generating units (EGUs). The multi-pollutant control system includes a hybrid selective non-catalytic reduction (SNCR)/in-duct selective catalytic reduction (SCR) system to reduce NOx emissions by {ge}60%, followed by a Turbosorp{reg_sign} circulating fluidized bed dry scrubber system to reduce emissions of SO{sub 2}, SO{sub 3}, HCl, and HF by {ge}95%. Mercury removal of {ge}90% is also targeted via the co-benefits afforded by the in-duct SCR, dry scrubber, and baghouse and by injection of activated carbon upstream of the scrubber, as required. The technology is particularly well suited, because of its relatively low capital and maintenance costs and small space requirements, to meet the needs of coal-fired units with capacities of 50-300 MWe. There are about 440 such units in the United States that currently are not equipped with SCR, flue gas desulfurization (FGD), or mercury control systems. These smaller units are a valuable part of the nation's energy infrastructure, constituting about 60 GW of installed capacity. However, with the onset of the Clean Air Interstate Rule, Clean Air Mercury Rule, and various state environmental actions requiring deep reductions in emissions of SO{sub 2}, NO{sub x}, and mercury, the continued operation of these units increasingly depends upon the ability to identify viable air pollution control retrofit options for them. The large capital costs and sizable space requirements associated with conventional technologies such as SCR and wet FGD make these technologies unattractive for many smaller units. The Greenidge Project aims to confirm the

  9. Composition of enamel pellicle from dental erosion patients.

    PubMed

    Carpenter, G; Cotroneo, E; Moazzez, R; Rojas-Serrano, M; Donaldson, N; Austin, R; Zaidel, L; Bartlett, D; Proctor, G

    2014-01-01

    Oral health is dependent upon a thin mobile film of saliva on soft and hard tissues. Salivary proteins adhere to teeth to form the acquired enamel pellicle which is believed to protect teeth from acid erosion. This study investigated whether patients suffering diet-induced dental erosion had altered enamel pellicles. Thirty patients suffering erosion were compared to healthy age-matched controls. Subjects wore a maxillary splint holding hydroxyapatite and human enamel blocks for 1 h. The acquired enamel pellicle was removed from the blocks and compared to the natural incisor pellicle. Basic Erosive Wear Examination scores confirmed that dental erosion was present in erosion patients and absent from healthy age-matched controls. Erosion patients had half the amount of proteins (BCA assay) within the acquired pellicle forming on splint blocks compared to normal controls (p < 0.05). In particular, statherin, a calcium-binding protein, was 35% less abundant (p < 0.05). Calcium concentration within the acquired pellicle was also reduced by 50% in erosion patients (p < 0.001). In contrast, the natural pellicle on the incisor had similar amounts of total protein in erosion patients and healthy controls. In summary, the formation of new acquired pellicles on surfaces was reduced in erosion patients, which may explain their greater susceptibility to acid erosion of teeth.

  10. Erosion of a geopolymer.

    SciTech Connect

    Goretta, K. C.; Chen, N.; Routbort, J. L.; Lukey, G. C.; van Deventer, J. S. J.

    2002-07-02

    Solid-particle erosion studies were conducted on a representative geopolymer. The test conditions were normal impact of 390-{micro}m angular Al{sub 2}O{sub 3} erodent particles moving at 50, 70, or 100 m/s. Steady-state erosion rates were obtained and the material-loss mechanism was studied by scanning electron microscopy. The geopolymer responded as a classic brittle material. Elastic-plastic indentation events led to formation of brittle cleavage cracks that resulted in spallation of material. The erosion rate was proportional to erodent velocity to the 2.3 power. The erosion rate and mechanism for the geopolymer were nearly identical to what has been observed for erosion of Si single crystals.

  11. SLUDGE TREATMENT PROJECT KOP CONCEPTUAL DESIGN CONTROL DECISION REPORT

    SciTech Connect

    CARRO CA

    2010-03-09

    This control decision addresses the Knock-Out Pot (KOP) Disposition KOP Processing System (KPS) conceptual design. The KPS functions to (1) retrieve KOP material from canisters, (2) remove particles less than 600 {micro}m in size and low density materials from the KOP material, (3) load the KOP material into Multi-Canister Overpack (MCO) baskets, and (4) stage the MCO baskets for subsequent loading into MCOs. Hazard and accident analyses of the KPS conceptual design have been performed to incorporate safety into the design process. The hazard analysis is documented in PRC-STP-00098, Knock-Out Pot Disposition Project Conceptual Design Hazard Analysis. The accident analysis is documented in PRC-STP-CN-N-00167, Knock-Out Pot Disposition Sub-Project Canister Over Lift Accident Analysis. Based on the results of these analyses, and analyses performed in support of MCO transportation and MCO processing and storage activities at the Cold Vacuum Drying Facility (CVDF) and Canister Storage Building (CSB), control decision meetings were held to determine the controls required to protect onsite and offsite receptors and facility workers. At the conceptual design stage, these controls are primarily defined by their safety functions. Safety significant structures, systems, and components (SSCs) that could provide the identified safety functions have been selected for the conceptual design. It is anticipated that some safety SSCs identified herein will be reclassified based on hazard and accident analyses performed in support of preliminary and detailed design.

  12. Regionalization of monthly rainfall erosivity patternsin Switzerland

    NASA Astrophysics Data System (ADS)

    Schmidt, Simon; Alewell, Christine; Panagos, Panos; Meusburger, Katrin

    2016-10-01

    One major controlling factor of water erosion is rainfall erosivity, which is quantified as the product of total storm energy and a maximum 30 min intensity (I30). Rainfall erosivity is often expressed as R-factor in soil erosion risk models like the Universal Soil Loss Equation (USLE) and its revised version (RUSLE). As rainfall erosivity is closely correlated with rainfall amount and intensity, the rainfall erosivity of Switzerland can be expected to have a regional characteristic and seasonal dynamic throughout the year. This intra-annual variability was mapped by a monthly modeling approach to assess simultaneously spatial and monthly patterns of rainfall erosivity. So far only national seasonal means and regional annual means exist for Switzerland. We used a network of 87 precipitation gauging stations with a 10 min temporal resolution to calculate long-term monthly mean R-factors. Stepwise generalized linear regression (GLM) and leave-one-out cross-validation (LOOCV) were used to select spatial covariates which explain the spatial and temporal patterns of the R-factor for each month across Switzerland. The monthly R-factor is mapped by summarizing the predicted R-factor of the regression equation and the corresponding residues of the regression, which are interpolated by ordinary kriging (regression-kriging). As spatial covariates, a variety of precipitation indicator data has been included such as snow depths, a combination product of hourly precipitation measurements and radar observations (CombiPrecip), daily Alpine precipitation (EURO4M-APGD), and monthly precipitation sums (RhiresM). Topographic parameters (elevation, slope) were also significant explanatory variables for single months. The comparison of the 12 monthly rainfall erosivity maps showed a distinct seasonality with the highest rainfall erosivity in summer (June, July, and August) influenced by intense rainfall events. Winter months have the lowest rainfall erosivity. A proportion

  13. Soil erosion rates from mixed soil and gravel surfaces in a wind tunnel

    SciTech Connect

    Ligotke, M.W.; Klopfer, D.C.

    1990-08-01

    Protective barriers have been identified as integral components of plans to isolate defense waste on the Hanford Site. The use of natural materials to construct protective barriers over waste site is being considered. Design requirements for protective barriers include preventing exposure of buried waste, and restricting penetration or percolation of surface waters through the waste zone. Studies were initiated to evaluate the effects of wind erosion on candidate protective barrier surfaces. A wind tunnel was used to provide controlled erosive stresses and to investigate the erosive effects of wind forces on proposed surface layers for protective barriers. Mixed soil and gravel surfaces were prepared and tested for resistance to wind erosion at the Pacific Northwest Laboratory Aerosol Wind Tunnel Research Facility. These tests were performed to investigate surface deflation caused by suspension of soil from various surface layer configurations and to provide a comparison of the relative resistance of the different surfaces to wind erosion. Planning, testing, and analyzing phases of this wind erosion project were coordinated with other tasks supporting the development of protective barriers. These tasks include climate-change predictions, field studies and modeling efforts. This report provides results of measurements of deflation caused by wind forces over level surfaces. Section 2.0 reviews surface layer characteristics and previous relevant studies on wind erosion, describes effects of erosion, and discusses wind tunnel modeling. Materials and methods of the wind tunnel tests are discussed in Section 3.0. Results and discussion are presented in Section 4.0, and conclusions and recommendations Section 5.0. 53 refs., 29 figs., 7 tabs.

  14. Impact of Water Control Projects on Fisheries Resources in Bangladesh

    PubMed

    Mirza; Ericksen

    1996-07-01

    Bangladesh is a very flat delta built up by the Ganges-Brahmaputra-Meghna/Barak river systems. Because of its geographical location, floods cause huge destruction of lives and properties almost every year. Water control programs have been undertaken to enhance development through mitigating the threat of disasters. This structural approach to flood hazard has severely affected floodplain fisheries that supply the major share of protein to rural Bangladesh, as exemplified by the Chandpur Irrigation Project. Although the regulated environment of the Chandpur project has become favorable for closed-water cultured fish farming, the natural open-water fishery loss has been substantial. Results from research show that fish yields were better under preproject conditions. Under project conditions per capita fish consumption has dropped significantly, and the price of fish has risen beyond the means of the poor people, so that fish protein in the diet of poor people is gradually declining. Bangladesh is planning to expand water control facilities to the remaining flood-prone areas in the next 15-20 years. This will cause further loss of floodplain fisheries. If prices for closed-water fish remain beyond the buying power of the poor, alternative sources of cheap protein will be required.

  15. Rainfall erosivity in Europe.

    PubMed

    Panagos, Panos; Ballabio, Cristiano; Borrelli, Pasquale; Meusburger, Katrin; Klik, Andreas; Rousseva, Svetla; Tadić, Melita Perčec; Michaelides, Silas; Hrabalíková, Michaela; Olsen, Preben; Aalto, Juha; Lakatos, Mónika; Rymszewicz, Anna; Dumitrescu, Alexandru; Beguería, Santiago; Alewell, Christine

    2015-04-01

    Rainfall is one the main drivers of soil erosion. The erosive force of rainfall is expressed as rainfall erosivity. Rainfall erosivity considers the rainfall amount and intensity, and is most commonly expressed as the R-factor in the USLE model and its revised version, RUSLE. At national and continental levels, the scarce availability of data obliges soil erosion modellers to estimate this factor based on rainfall data with only low temporal resolution (daily, monthly, annual averages). The purpose of this study is to assess rainfall erosivity in Europe in the form of the RUSLE R-factor, based on the best available datasets. Data have been collected from 1541 precipitation stations in all European Union (EU) Member States and Switzerland, with temporal resolutions of 5 to 60 min. The R-factor values calculated from precipitation data of different temporal resolutions were normalised to R-factor values with temporal resolutions of 30 min using linear regression functions. Precipitation time series ranged from a minimum of 5 years to a maximum of 40 years. The average time series per precipitation station is around 17.1 years, the most datasets including the first decade of the 21st century. Gaussian Process Regression (GPR) has been used to interpolate the R-factor station values to a European rainfall erosivity map at 1 km resolution. The covariates used for the R-factor interpolation were climatic data (total precipitation, seasonal precipitation, precipitation of driest/wettest months, average temperature), elevation and latitude/longitude. The mean R-factor for the EU plus Switzerland is 722 MJ mm ha(-1) h(-1) yr(-1), with the highest values (>1000 MJ mm ha(-1) h(-1) yr(-1)) in the Mediterranean and alpine regions and the lowest (<500 MJ mm ha(-1) h(-1) yr(-1)) in the Nordic countries. The erosivity density (erosivity normalised to annual precipitation amounts) was also the highest in Mediterranean regions which implies high risk for erosive events and floods.

  16. Canada Chair in hypertension prevention and control: a pilot project.

    PubMed

    Campbell, Norm R C

    2007-05-15

    A five-year pilot project was initiated in Canada to fund an individual to lead the effort in improving hypertension prevention and control. As the initial recipient of the funding, the author's objectives were to provide leadership to improve the management of hypertension through enhancements to the Canadian Hypertension Education Program, to increase public knowledge of hypertension, to reduce the prevalence of hypertension by reducing dietary sodium additives and to develop a comprehensive hypertension surveillance program. The initiative has received strong support from the hypertension community, the Public Health Agency of Canada, the Heart and Stroke Foundation of Canada, and many Canadian health care professional and scientific organizations. Progress has been made on all objectives. The pilot project was funded by The Canadian Hypertension Society, the Canadian Institutes of Health Research and sanofi-aventis, in partnership with Blood Pressure Canada, and will finish in July 2011.

  17. Evaluation of Rhizobium tropici-derived Biopolymer for Erosion Control of Protective Berms. Field Study: Iowa Army Ammunition Plant

    DTIC Science & Technology

    2016-06-01

    biopolymer outperformed the commercial petroleum-based polymers in all applications . ERDC TR-16-5 5 Figure 1-2. Comparison of the production of...manufacturer estimates of application times, the treatment was successful. Biologically produced polymers have a number of unique benefits when compared...biopolymer with grass seed. The control area received plain water and seed. Evaluated biopolymer application methods include single surface application

  18. The INCO Expert System Project: CLIPS in Shuttle mission control

    NASA Technical Reports Server (NTRS)

    Rasmussen, Arthur N.; Muratore, John F.; Heindel, Troy A.

    1990-01-01

    The INCO (Integrated Communications Officer) Expert System Project (IESP) was undertaken in 1987 by the Mission Operations Directorate (MOD) at NASA's Johnson Space Center (JSC) to explore the use of advanced automation in the mission operations arena. One of MOD's primary responsibilities in the space shuttle program is the manning of the flight control positions in the Mission Control Center (MCC) at JSC. The MCC is the central hub for all ground support activities in support of Space Shuttle missions. Its responsibility extends from the moment of lift-off from the launch pad though the completion of landing. The flight controllers in the MCC are tasked with monitoring the health and status of all on-board systems and payloads, detecting and remedying errors and failures, and modifying flight activity plans accordingly.

  19. Project B610 process control configuration acceptance test procedure

    SciTech Connect

    Silvan, G.R.

    1994-09-20

    The purpose of this test is to verify the Westinghouse configuration of the MICON A/S Distributed Control System for project B610. The following will be verified: proper assignment and operation of all field inputs to and outputs from the MICON Termination panels; proper operation of all display data on the operator`s console; proper operation of all required alarms; and proper operation of all required interlocks. The MICON A/S control system is configured to replace all the control, indication, and alarm panels now located in the Power Control Room. Nine systems are covered by this control configuration, 2736-ZB HVAC, 234-5Z HVAC, Process Vacuum, Dry Air, 291-Z Closed Loop Cooling, Building Accelerometer, Evacuation Siren, Stack CAMs, and Fire. The 2736-ZB HVAC system consists of the ventilation controls for 2736-ZB and 2736-Z as well as alarms for the emergency generators and 232-Z. The 234-5Z HVAC system is the ventilation controls for 235-5Z and 236-Z buildings. Process Vacuum covers the controls for the 26 inch vacuum system. Dry Air covers the controls for the steam and electric air dryers. The 291-Z Closed Loop Cooling system consists of the status indications and alarms for the 291-Z compressor and vacuum pump closed loop cooling system. The rest of closed loop cooling was tested earlier. The Building Accelerometer system consists of the status indications for the two seismic system accelerometers. The Evacuation Siren system includes the controls for the evacuation and take cover sirens. Stack CAMs cover the alarms for the various building ventilation stack continuous air monitors. Finally, the Fire system covers the various fire alarms now located in Room 321-A.

  20. Splash erosion. A bibliometric Review

    NASA Astrophysics Data System (ADS)

    Fernández Raga, M. B.

    2012-04-01

    Ellison (1944) developed the splash board as a system for measuring splash erosion that was both cheap and reliable. Bollinne (1975), Morgan (1978, 1981). Mutchler (1967) described another different type of splash detectors according to whether they were passive or could register data. In the study mentioned above these authors included bottles, funnels, glasses, photography, markers. After that several devices has been made up like the splash sampler (Leguedois et al., 2005), soil tray (Van Dijk et al., 2002), splash funnel (Terry, 1989) and several rain cups (Fernandez-Raga et al., 2010; Molina and Llinares, 1996; Torri et al., 1987). Splash erosion research has materialized in the form of a number of papers published in international journals. The database of bibliographic references employed has been one of the most prestigious ones: theWeb of Science (ISI). The search was carried out on January 27th 2012. Among the 3x10^8 scholarly documents included in the Science Citation Index Expanded (SCI-EXPANDED) 1899 to present , the searching engine located 439 containing the word "splash erosion*", where the asterisk acts as a wildcard for any letter or group of letters. Of these, 383 were classified as articles, 87 as proceeding papers, 5 as editorial material, 2 as notes and 1 as correction. These documents have been published in 163 different journals, although four are particularly recurrent: Earth surface processes and Landforms, Catena, Soil Science Society of America Journal and Hydrological processes, with 41, 35, 35 and 26 published documents respectively. A geographic analysis of these articles has been carried out in an attempt to determine in what parts of the world research projects were making use of splash erosion. The results are that anglo-saxon countries, as USA, England and Australia dominate, particularly USA, with 130 articles. China and Japan are large communities of researches too, and some Central European countries as Belgium, France Germany

  1. Plant materials and amendments for controlling wind and water erosion on a fly ash disposal area: TVA Colbert Fossil Plant, Alabama

    SciTech Connect

    Maddox, J.J.; Behel, D.; Soileau, J.M.; Kelsoe, J.

    1996-12-31

    Fly ash disposal sites adjacent to fossil fueled generating plants are subject to wind and water erosion which increases the operation and maintenance costs. Gullies and unstable areas in the disposal sites require expensive leveling and filling practices. Test evaluated both warm- and cool-season cover crops established by either sod or seed. Amendments to the ash consisted of composted poultry litter (CPL), soil, soil+CPL, fertilizer and beneficial soil microbes including mycorrhizal fungi. Turf sods (419 Bermuda, Emerald zoysia, and Raleigh St. Augustine) were compared in greenhouse and field studies. Six legumes and 12 grass species were tested in the greenhouse as seeded cover crops using similar amendments and raw poultry litter (PL). Legumes grew better with CPL and Boil amendments and grasses grew better on PL and soil amendments possibly due to differences in N requirements and N supply. Cool season crops generally grew faster than warm season species in the greenhouse tests. Amendments should be mixed with the FA to ameliorate the effects of boron and salt toxicity and to increase the water holding capacity. Bermuda sod grew faster than either St, Augustine or Emerald zoysia, but requires more water. A microbial amendment increased dry matter yields of bermuda sod 2 to 3 times after 40 to 60 days over unamended controls. Microbial amendments may be justified on an economic and sustainable basis. A field study is assessing the environmental and cultural requirements to grow a cover crop on an annual basis.

  2. Erosion in America

    SciTech Connect

    Not Available

    1984-03-23

    The US loses about five billion tons of soil a year from erosion, and scientists estimate that from 20 to 50% of world cropland suffers from excessive erosion. The effect of erosion is a loss in both land and water productivity. When combined with the problems of overpopulation, overgrazing, and deforestation, the environmental impacts are very serious. There are some signs that countries are beginning to adopt conservation tilling techniques, but even cooperative government programs in the US such as the 1983 Payment-in-Kind (PIK) program have had only partial success because of expanded production on marginal farmlands. 20 reference 5 figures.

  3. Topical clobetasol in the treatment of atrophic-erosive oral lichen planus: a randomized controlled trial to compare two preparations with different concentrations.

    PubMed

    Carbone, M; Arduino, P G; Carrozzo, M; Caiazzo, G; Broccoletti, R; Conrotto, D; Bezzo, C; Gandolfo, S

    2009-02-01

    Oral lichen planus (OLP) is a chronic inflammatory disease that can be painful, mainly in the atrophic and erosive forms. Numerous drugs have been used with dissimilar results, but most treatments are empirical and do not have adequate control groups or correct study designs. However, to date, the most commonly employed and useful agents for the treatment of LP are topical corticosteroids. A randomized, double-blind, placebo-controlled trial has been designed to compare the efficacy and safety of two different formulations of clobetasol, a very potent topical steroid, in the topical management of OLP and to evaluate which gives the longest remission from signs and symptoms. Thirty-five consecutive patients were divided into two groups: the first received clobetasol propionate 0.025% and the second was given clobetasol propionate 0.05%. Both drugs were placed in 4% hydroxyethyl cellulose bioadhesive gel. Anti-mycotic prophylaxis was also added. After the end of therapy, patients received a 2-month follow-up. In all, 14 of the 15 clobetasol 0.025% patients (93%) and 13 of the 15 clobetasol 0.05% patients (87%), had symptoms improvement after 2 months of therapy (P = 0.001 in both groups). Also, 13 of the 15 clobetasol 0.025% patients (87%) and 11 of the 15 clobetasol 0.05% patients (73%) had clinical improvement after 2 months of therapy (P < 0.05 in both groups). No statistical differences were found in comparing the two different formulations. A larger concentration of the active molecules cannot further improve the therapeutic findings or optimize the obtained results in a significant manner.

  4. Dental Surface Texture Characterization Based on Erosive Tooth Wear Processes.

    PubMed

    Hara, A T; Livengood, S V; Lippert, F; Eckert, G J; Ungar, P S

    2016-05-01

    The differential diagnosis of dental wear lesions affects their clinical management. We hypothesized that surface texture parameters can differentiate simulated erosion, abrasion, and erosion-abrasion lesions on human enamel and dentin. This in vitro study comprised 2 parts (both factorial 4 × 2), with 4 lesion types (erosion, abrasion, erosion-abrasion, and sound [no lesion; control]) and 2 substrates (enamel and dentin). Flattened/polished dental specimens were used in part 1, whereas natural dental surfaces were used in part 2. Testing surfaces were evaluated in blind conditions, using average surface roughness (Sa) and the following scale-sensitive fractal analysis parameters: area-scale fractal complexity (Asfc), exact proportion length-scale anisotropy of relief (eplsar), scale of maximum complexity (Smc), and textural fill volume (Tfv). Two-way analyses of variance, followed by Fisher's protected least significant difference tests (α = 0.05), were used to evaluate the effects of lesion and substrate. Classification trees were constructed to verify the strength of potential associations of the tested parameters. In part 1,Asfc, Sa, and Tfv were able to differentiate erosion and erosion-abrasion lesions from the sound (no lesion) control in both substrates; only Asfc differentiated erosion and erosion-abrasion enamel lesions (allP< 0.05). The best association of parameters correctly classified up to 84% and 94% of the lesions on enamel and dentin, respectively. In part 2, only Asfc differentiated erosion and erosion-abrasion lesions from the sound (no lesion) control in both substrates, whereas eplsar was able to differentiate erosion from erosion-abrasion (allP< 0.05). The association of parameters correctly classified up to 81% and 91% of the lesions in enamel and dentin, respectively.Asfc, Sa, and Tfv were able to differentiate erosion and erosion-abrasion lesions, despite their complicated surface textures. The association of parameters improved the

  5. Potential for monitoring soil erosion features and soil erosion modeling components from remotely sensed data

    NASA Technical Reports Server (NTRS)

    Langran, K. J.

    1983-01-01

    Accurate estimates of soil erosion and its effects on soil productivity are essential in agricultural decision making and planning from the field scale to the national level. Erosion models have been primarily developed for designing erosion control systems, predicting sediment yield for reservoir design, predicting sediment transport, and simulating water quality. New models proposed are more comprehensive in that the necessary components (hydrology, erosion-sedimentation, nutrient cycling, tillage, etc.) are linked in a model appropriate for studying the erosion-productivity problem. Recent developments in remote sensing systems, such as Landsat Thematic Mapper, Shuttle Imaging Radar (SIR-B), etc., can contribute significantly to the future development and operational use of these models.

  6. Erosion of soil organic carbon: implications for carbon sequestration

    USGS Publications Warehouse

    Van Oost, Kristof; Van Hemelryck, Hendrik; Harden, Jennifer W.; McPherson, B.J.; Sundquist, E.T.

    2009-01-01

    Agricultural activities have substantially increased rates of soil erosion and deposition, and these processes have a significant impact on carbon (C) mineralization and burial. Here, we present a synthesis of erosion effects on carbon dynamics and discuss the implications of soil erosion for carbon sequestration strategies. We demonstrate that for a range of data-based parameters from the literature, soil erosion results in increased C storage onto land, an effect that is heterogeneous on the landscape and is variable on various timescales. We argue that the magnitude of the erosion term and soil carbon residence time, both strongly influenced by soil management, largely control the strength of the erosion-induced sink. In order to evaluate fully the effects of soil management strategies that promote carbon sequestration, a full carbon account must be made that considers the impact of erosion-enhanced disequilibrium between carbon inputs and decomposition, including effects on net primary productivity and decomposition rates.

  7. Erosion dynamics of a wet granular medium.

    PubMed

    Lefebvre, Gautier; Jop, Pierre

    2013-09-01

    Liquid may give strong cohesion properties to a granular medium, and confer a solidlike behavior. We study the erosion of a fixed circular aggregate of wet granular matter subjected to a flow of dry grains inside a half-filled rotating drum. During the rotation, the dry grains flow around the fixed obstacle. We show that its diameter decreases linearly with time for low liquid content, as wet grains are pulled out of the aggregate. This erosion phenomenon is governed by the properties of the liquids. The erosion rate decreases exponentially with the surface tension while it depends on the viscosity to the power -1. We propose a model based on the force fluctuations arising inside the flow, explaining both dependencies: The capillary force acts as a threshold and the viscosity controls the erosion time scale. We also provide experiments using different flowing grains, confirming our model.

  8. Water droplet erosion mechanisms of Ti-6Al-4V

    NASA Astrophysics Data System (ADS)

    Kamkar Zahmatkesh, Niloofar

    Water impingement erosion of materials can be a life-limiting phenomenon for the components in many erosive environments. For example, aircraft body exposed to rain, steam turbine blade, and recently in gas turbine coupled with inlet fogging system. The last is the focus of this study. Inlet fogging system is the most common method used to augment gas turbine output during hot days; high ambient temperature causes strong deterioration of the engine performance. Micro-scaled droplets introduced into the inlet airflow allow the cooling of entering air as well as intercooling the compressor (overspray) and thus optimizes the output power. However, erosion damage of the compressor blades in overspray stage is one of the major concerns associated with the inlet fogging system. The main objective of this research work (CRIAQ MANU419 project) is to understand the erosion induced by water droplets on Titanium alloy to eventually optimize the erosion resistance of the Ti-based compressor blade. Therefore, characterization of the water droplet erosion damage on Ti-6Al-4V receives the major importance. The influence of base material microstructure and impact parameters were considered in erosion evaluation in present study. This work covers the characterization of the erosion damage on Ti-6Al-4V alloy in two parts: - The water droplet erosion damage through a novel experimental approach. The collected data were processed both qualitatively and quantitatively for multi-aspects damage study. - The influence of impact velocity on erosion in an attempt to represent the in-service conditions.

  9. Conventional and anti-erosion fluoride toothpastes: effect on enamel erosion and erosion-abrasion.

    PubMed

    Ganss, C; Lussi, A; Grunau, O; Klimek, J; Schlueter, N

    2011-01-01

    New toothpastes with anti-erosion claims are marketed, but little is known about their effectiveness. This study investigates these products in comparison with various conventional NaF toothpastes and tin-containing products with respect to their erosion protection/abrasion prevention properties. In experiment 1, samples were demineralised (10 days, 6 × 2 min/day; citric acid, pH 2.4), exposed to toothpaste slurries (2 × 2 min/day) and intermittently stored in a mineral salt solution. In experiment 2, samples were additionally brushed for 15 s during the slurry immersion time. Study products were 8 conventional NaF toothpastes (1,400-1,490 ppm F), 4 formulations with anti-erosion claims (2 F toothpastes: NaF + KNO(3) and NaF + hydroxyapatite; and 2 F-free toothpastes: zinc-carbonate-hydroxyapatite, and chitosan) and 2 Sn-containing products (toothpaste: 3,436 ppm Sn, 1,450 ppm F as SnF(2)/NaF; gel: 970 ppm F, 3,030 ppm Sn as SnF(2)). A mouth rinse (500 ppm F as AmF/NaF, 800 ppm Sn as SnCl(2)) was the positive control. Tissue loss was quantified profilometrically. In experiment 1, most NaF toothpastes and 1 F-free formulation reduced tissue loss significantly (between 19 and 42%); the Sn-containing formulations were the most effective (toothpaste and gel 55 and 78% reduction, respectively). In experiment 2, only 4 NaF toothpastes revealed significant effects compared to the F-free control (reduction between 29 and 37%); the F-free special preparations and the Sn toothpaste had no significant effect. The Sn gel (reduction 75%) revealed the best result. Conventional NaF toothpastes reduced the erosive tissue loss, but had limited efficacy regarding the prevention of brushing abrasion. The special formulations were not superior, or were even less effective.

  10. Issues of upscaling in space and time with soil erosion models

    NASA Astrophysics Data System (ADS)

    Brazier, R. E.; Parsons, A. J.; Wainwright, J.; Hutton, C.

    2009-04-01

    Soil erosion - the entrainment, transport and deposition of soil particles - is an important phenomenon to understand; the quantity of soil loss determines the long term on-site sustainability of agricultural production (Pimental et al., 1995), and has potentially important off-site impacts on water quality (Bilotta and Brazier, 2008). The fundamental mechanisms of the soil erosion process have been studied at the laboratory scale, plot scale (Wainwright et al., 2000), the small catchment scale (refs here) and river basin scale through sediment yield and budgeting work. Subsequently, soil erosion models have developed alongside and directly from this empirical work, from data-based models such as the USLE (Wischmeier and Smith, 1978), to ‘physics or process-based' models such as EUROSEM (Morgan et al., 1998) and WEPP (Nearing et al., 1989). Model development has helped to structure our understanding of the fundamental factors that control soil erosion process at the plot and field scale. Despite these advances, however, our understanding of and ability to predict erosion and sediment yield at the same plot, field and also larger catchment scales remains poor. Sediment yield has been shown to both increase and decrease as a function of drainage area (de Vente et al., 2006); the lack of a simple relationship demonstrates complex and scale-dependant process domination throughout a catchment, and emphasises our uncertainty and poor conceptual basis for predicting plot to catchment scale erosion rates and sediment yields (Parsons et al., 2006b). Therefore, this paper presents a review of the problems associated with modelling soil erosion across spatial and temporal scales and suggests some potential solutions to address these problems. The transport-distance approach to scaling erosion rates (Wainwright, et al., 2008) is assessed and discussed in light of alternative techniques to predict erosion across spatial and temporal scales. References Bilotta, G.S. and

  11. Streambank Protection and Erosion Control.

    DTIC Science & Technology

    1987-01-01

    figure 29. Diagonal Bracing Port Elevation - - Dragon Cl Bracing Br T al Waling A re Mesh orTYD a’ %reM Barbed Wire B askeSt S t r e a m W i r e M e s h o...the nearly vertical walls of f- .a narrow steep gorge in a mountain area, or somewhere in between these .,, *two extreme cases. The stream water can be...Figure 22. Trench-fill revetment ( Source 2 ) •.-. 7.3 Gan [25] Gabions are prefabricated wire-mesh cages or baskets divided by %"• .. diaphragms into

  12. Design Analysis for a Scaled Erosion Test

    SciTech Connect

    Lee, S.Y.

    2002-04-10

    In support of a slurry wear evaluation in the pretreatment filtration and evaporation systems of RPP-WTP, Engineering Modeling and Simulation Group (EMSG) has developed the computational models to help guide component design and scaling decisions and to assist in the full-scale analyses. This report deals with the filtration system. In this project, computational fluid dynamics (CFD) methods were applied to ensure that the test facility design would capture the erosion phenomena expected in the full-scale cross-flow ultrafiltration facility. The literature survey was initially performed to identify the principal mechanisms of erosion for a solids laden fluid.

  13. A project plans to develop two ASICs for CCD controller

    NASA Astrophysics Data System (ADS)

    Song, Qian; Wei, Mingzhi; Sun, Quan; Zhang, Yuheng

    2016-07-01

    Astronomical instrumentation, in many cases, especially the large field of view application while huge mosaic CCD or CMOS camera is needed, requires the camera electronics to be much more compact and of much smaller the size than the controller used to be. Making the major parts of CCD driving circuits into an ASIC or ASICs can greatly bring down the controller's volume, weight and power consumption and make it easier to control the crosstalk brought up by the long length of the cables that connect the CCD output ports and the signal processing electronics, and, therefore, is the most desirable approach to build the large mosaic CCD camera. A project endeavors to make two ASICs, one to achieve CCD signal processing and another to provide the clock drives and bias voltages, is introduced. The first round of design of the two ASICs has been completed and the devices have just been manufactured. Up to now the test of one of the two, the signal processing ASIC, was partially done and the linearity has reached the requirement of the design.

  14. A Rangeland Hydrology and Erosion Model for Developing Ecological Site Descriptions

    NASA Astrophysics Data System (ADS)

    Nearing, M. A.; Hernandez, M.; Armendariz, G.; Barker, S.; Williams, C. J.

    2014-12-01

    Predicting soil erosion is common practice in natural resource management for assessing the effects of management practices and control techniques of soil productivity, sediment delivery and off site water quality. The Rangeland Hydrology and Erosion Model (RHEM) was designed for this purpose. RHEM is an event-based model that estimates runoff, erosion, and sediment delivery rates and volumes at the spatial scale of the hillslope and the temporal scale of as single rainfall event. It represents erosion processes under normal and fire-impacted rangeland conditions. Moreover, it adopts a new splash erosion and thin sheet -flow transport equation developed from rangeland data, and it links the model hydrologic and erosion parameters with rangeland plant community by providing a new system of parameter estimation equations based on 204 plots at 49 rangeland sites distributed across 15 western U.S. states. Testing was done using long-term runoff and erosion data from small semi-aridland catchments. One of our goals with this project is to develop a framework for incorporating key ecohydrologic information/relationships in Ecological Site Descriptions and thereby enhanced utility of Ecological Site Descriptions s for guiding management. These key ecohydrologic relationships govern the ecologic resilience of the various states and community phases on many rangeland ecological sites and are strongly affected by management practices, land use, and disturbances. However, ecohydrologic data and relationships are often missing in Ecological Site Descriptions and resilience-based state-and-transition models. In this study we applied the RHEM model to data from multiple points in several ecological sites in Arizona, New Mexico, and Utah to assess the utility of the model for informing these Ecological Site Descriptions.

  15. Integrated Project Scheduling and Staff Assignment with Controllable Processing Times

    PubMed Central

    Framinan, Jose M.

    2014-01-01

    This paper addresses a decision problem related to simultaneously scheduling the tasks in a project and assigning the staff to these tasks, taking into account that a task can be performed only by employees with certain skills, and that the length of each task depends on the number of employees assigned. This type of problems usually appears in service companies, where both tasks scheduling and staff assignment are closely related. An integer programming model for the problem is proposed, together with some extensions to cope with different situations. Additionally, the advantages of the controllable processing times approach are compared with the fixed processing times. Due to the complexity of the integrated model, a simple GRASP algorithm is implemented in order to obtain good, approximate solutions in short computation times. PMID:24895672

  16. Active Spacecraft Potential Control: Results From the Double Star Project

    NASA Astrophysics Data System (ADS)

    Torkar, K.; Fazakerley, A.; Steiger, W.

    2006-10-01

    The ion emitter instrument "active spacecraft potential control" (ASPOC) has been used successfully in several magnetospheric missions including the European Space Agency Cluster Project. An improved version has been developed for the equatorial spacecraft of the Chinese-European Double Star mission (TC-1) launched in December 2003. The modifications include a new design of the ion emitter modules. As a result, higher currents than in previous missions can be achieved. The main objective of the investigation is the reduction of positive spacecraft potential in order to minimize perturbations to the plasma measurements onboard, in particular to the plasma electron instrument PEACE. These data show an almost complete suppression of photoelectrons when ASPOC is emitting at 30- to 50-muA beam current. The angular distribution of the electrons in the presence of the ion beam is investigated in detail. The measurement of ambient electron distributions is highly improved.

  17. Management of a large distributed control system development project

    SciTech Connect

    Gurd, D. P.

    2002-01-01

    Building an accelerator at six geographically dispersed sites is quite mad, but politically expedient. The Spallation Neutron Source (SNS), currently under construction in Oak Ridge, Tennessee, combines a pulsed 1 Gev H{sup -} superconducting linac with a compressor ring to deliver 2 MW of beam power to a liquid mercury target for neutron production [1]. Accelerator components, target and experimental (neutron-scattering) instruments are being developed collaboratively by Lawrence Berkeley (Ion Source and Front End), Los Alamos (Linac), Thomas Jefferson (Cryosystems), Brookhaven (Compressor Ring), Oak Ridge (Target and Conventional Facilities) and Argonne (Neutron Scattering Instruments) National Laboratories. Similarly, a team distributed among all of the participating laboratories is developing the EPICS-based control system. this paper discusses the management model and strategies being used to address the unusual issues of organization, communication, standardization, integration and hand-off inherent in this widely-distributed project.

  18. Instantaneous Project Controls: Current Status, State of the Art, Benefits, and Strategies

    ERIC Educational Resources Information Center

    Abbaszadegan, Amin

    2016-01-01

    Despite advancements in construction and construction-related technology, capital project performance deviations, typically overruns, remain endemic within the capital projects industry. Currently, management is generally unaware of the current status of their projects, and thus monitoring and control of projects are not achieved effectively. In…

  19. 23 CFR 751.23 - Concurrent junkyard control and right-of-way projects.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Concurrent junkyard control and right-of-way projects...-WAY AND ENVIRONMENT JUNKYARD CONTROL AND ACQUISITION § 751.23 Concurrent junkyard control and right-of-way projects. The State is encouraged to coordinate junkyard control and highway right-of-way...

  20. An empirical approach to estimate soil erosion risk in Spain.

    PubMed

    Martín-Fernández, Luis; Martínez-Núñez, Margarita

    2011-08-01

    Soil erosion is one of the most important factors in land degradation and influences desertification worldwide. In 2001, the Spanish Ministry of the Environment launched the 'National Inventory of Soil Erosion (INES) 2002-2012' to study the process of soil erosion in Spain. The aim of the current article is to assess the usefulness of this National Inventory as an instrument of control, measurement and monitoring of soil erosion in Spain. The methodology and main features of this National Inventory are described in detail. The results achieved as of the end of May 2010 are presented, together with an explanation of the utility of the Inventory as a tool for planning forest hydrologic restoration, soil protection, erosion control, and protection against desertification. Finally, the authors make a comparative analysis of similar initiatives for assessing soil erosion in other countries at the national and European levels.

  1. A wood-strand material for wind erosion control: effects on total sediment loss, PM10 vertical flux, and PM10 loss

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind erosion is a widespread problem in much of the western United States due to arid conditions and persistent winds. Fugitive dust emitted from eroding land poses a risk to both environmental quality and human health. The Clean Air Act, established in 1971, was revised in 1987 to include ambient a...

  2. Can erosion control structures in large dryland arroyo channels lead to resilient riparian and cienega restoration? Observations from LiDAR, monitoring and modeling at Rancho San Bernardino, Sonora, MX

    NASA Astrophysics Data System (ADS)

    DeLong, S.; Henderson, W. M.

    2012-12-01

    The use of erosion control structures to mitigate or even reverse erosion and to restore ecological function along dryland channels (arroyos and gullies) has led to a long list of both successful and failed restoration efforts. We propose that successful implementation of "engineering" approaches to fluvial restoration that include in-channel control structures require either a quantitative approach to design (by scientists and engineers), or intimate on-the-ground knowledge, local observation, and a commitment to adapt and maintain restoration efforts in response to landscape change (by local land managers), or both. We further propose that the biophysical interactions among engineering, sedimentation, flood hydrology and vegetation reestablishment are what determine resilience to destructive extreme events that commonly cause erosion control structure failure. Our insights come from comprehensive monitoring of a remarkable experiment underway at Ranch San Bernardino, Sonora, MX. At this site, private landowners are working to restore ecosystem function to riparian corridors and former cieñega wetlands using cessation of grazing; vegetation planting; upland grass restoration; large scale rock gabions (up to 100 m wide) to encourage local sediment deposition and water storage; and large earthen berms (up to 900 m wide) with cement spillways that form reservoirs that fill rapidly with water and sediment. Well-planned and managed erosion control structures have been used elsewhere successfully in smaller gully networks, but we are unaware of a comparable attempt to use gabions and berms for the sole purpose of ecological restoration along >10 km of arroyo channels draining watersheds on the order of ~400 km2 and larger. We present an approach to monitoring the efficacy of arroyo channel restoration using terrestrial and airborne LiDAR, remote sensing, streamflow monitoring, shallow groundwater monitoring, hydrological modeling and field observation. Our methods

  3. An alternate approach to hospital cost control: the Rochester project.

    PubMed Central

    Sorensen, A A; Saward, E W

    1978-01-01

    The rapid escalation in health care costs has demonstrated a need to control costs in general and hospital costs in particular. In New York State, efforts at control have followed one of several paths, including reduction of Medicaid program expenditures, elimination of hospital beds, and prospective reimbursement of hospital costs. Although some success has been achieved in each of these areas, hospital costs containment has not been as successful as had been hoped. A new project called MAXICAP, being developed in the Rochester region, seeks to link payment with regional hospital planning. MAXICAP represents a voluntary attempt by hospitals, third party payers, planners, consumers, and governmental agencies to devise a prospective hospital payment system. Under this system community hospital plans in the Rochester region would be integrated and a cap imposed on both revenues and expenses for acute hospital care. The principal advantage of the MAXICAP is that it offers a mechanism for linking hospital planning with payment functions on a regional basis. The principal disadvantage is that the success of the MAXICAP depends upon the voluntary cooperation of the vast majority of the acute care hospitals in the area--hospitals that may be scattered throughout a relatively large region. PMID:98805

  4. Particulate erosion mechanisms

    NASA Technical Reports Server (NTRS)

    Veerabhadrarao, P.; Buckley, D. H.

    1983-01-01

    Particulate damage and erosion of ductile metals are today plaguing design and field engineers in diverse fields of engineering and technology. It was found that too many models and theories were proposed leading to much speculation from debris analysis and failure mechanism postulations. Most theories of solid particle erosion are based on material removal models which do not fully represent the actual physical processes of material removal. The various mechanisms proposed thus far are: melting, low-cycle fatigue, extrusion, delamination, shear localization, adhesive material transfer, etc. The experimental data on different materials highlighting the observed failure modes of the deformation and cutting wear processes using optical and scanning electron microscopy are presented. The most important mechanisms proved from the experimental observations of the specimens exposed to both spherical and angular particles are addressed, and the validity of the earlier theories discussed. Both the initial stages of damage and advanced stages of erosion were studied to gain a fundamental understanding of the process.

  5. Arctic Coastal Erosion Modeling

    NASA Astrophysics Data System (ADS)

    Ravens, T. M.; Jones, B.; Zhang, J.; Tweedie, C. E.; Erikson, L. H.; Gibbs, A.; Richmond, B. M.

    2011-12-01

    A process-based coastal erosion/shoreline change model has been developed for Arctic coastal bluffs subject to niche erosion/block collapse. The model explicitly accounts for many environmental/geographic variables including: water temperature, water level, wave height, and bluff height. The model was originally developed for a small coastal segment near Drew Point, Beaufort Sea, Alaska. This coastal setting has experienced a dramatic increase in erosion since the early 2000's. The bluffs at this site are 3-4 m tall and consist of ice-wedge bounded blocks of fine-grained sediments cemented by ice-rich permafrost and capped with a thin organic layer. The bluffs are typically fronted by a narrow (~ 5 m wide) beach or none at all. During a storm surge, the sea contacts the base of the bluff and a niche is formed through thermal and mechanical erosion. The niche grows both vertically and laterally and eventually undermines the bluff, leading to block failure or collapse. The fallen block is then eroded both thermally and mechanically by waves and currents, which must occur before a new niche forming episode may begin. The model has been calibrated based on shoreline change data at Drew Point for two time periods: 1979-2002 and 2002-2007. Measured and modeled shoreline change rates were about 8 m/yr and 16 m/yr, for the earlier and later periods, respectively. In this paper, this work is extended to include modeling and measurement of coastal erosion at Drew Point on an annual basis for the period 2007-2010. In addition, the model is applied at three other Arctic coastal locations - Elson Lagoon, Cape Halkett, and Barter Island - where niche erosion/block collapse prevails.

  6. Controlled ecological life support system breadboard project, 1988

    NASA Technical Reports Server (NTRS)

    Knott, W. M.

    1990-01-01

    The Closed Ecological Life Support System (CELSS) Breadboard Project, NASA's effort to develop the technology required to produce a functioning bioregenerative system, is discussed. The different phases of the project and its current status are described. The relationship between the project components are shown, and major project activities for fiscal years 1989 to 1993 are listed. The Biomass Production Chamber (BPC) became operational and tests of wheat as a single crop are nearing completion.

  7. Dating and quantification of erosion processes based on exposed roots

    NASA Astrophysics Data System (ADS)

    Stoffel, Markus; Corona, Christophe; Ballesteros-Cánovas, Juan Antonio; Bodoque, José Maria

    2013-08-01

    Soil erosion is a key driver of land degradation and heavily affects sustainable land management in various environments worldwide. An appropriate quantification of rates of soil erosion and a localization of hotspots are therefore critical, as sediment loss has been demonstrated to have drastic consequences on soil productivity and fertility. A consistent body of evidence also exists for a causal linkage between global changes and the temporal frequency and magnitude of erosion, and thus calls for an improved understanding of dynamics and rates of soil erosion for an appropriate management of landscapes and for the planning of preventive or countermeasures. Conventional measurement techniques to infer erosion rates are limited in their temporal resolution or extent. Long-term erosion rates in larger basins have been analyzed with cosmogenic nuclides, but with lower spatial and limited temporal resolutions, thus limiting the possibility to infer micro-geomorphic and climatic controls on the timing, amount and localization of erosion. If based on exposed tree roots, rates of erosion can be inferred with up to seasonal resolution, over decades to centuries of the past and for larger surfaces with homogenous hydrological response units. Root-based erosion rates, thus, constitute a valuable alternative to empirical or physically-based approaches, especially in ungauged basins, but will be controlled by individual or a few extreme events, so that average annual rates of erosion might be highly skewed. In this contribution, we review the contribution made by this biomarker to the understanding of erosion processes and related landform evolution. We report on recent progress in root-based erosion research, illustrate possibilities, caveats and limitations of reconstructed rates, and conclude with a call for further research on various aspects of root-erosion research and for work in new geographic regions.

  8. Wind Erosion in Tithonium

    NASA Technical Reports Server (NTRS)

    2005-01-01

    30 April 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows wind-eroded sedimentary rocks in Tithonium Chasma, one of the troughs of the Valles Marineris system. The winds responsible for the majority of the erosion blew from the northeast (upper right), creating yardangs (wind erosion ridges) with their tapered ends pointing downwind.

    Location near: 4.6oS, 88.3oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Winter

  9. Ecological site-based assessments of wind and water erosion: informing accelerated soil erosion management in rangelands

    USGS Publications Warehouse

    Webb, Nicholas P.; Herrick, Jeffrey E.; Duniway, Michael C.

    2014-01-01

    Accelerated soil erosion occurs when anthropogenic processes modify soil, vegetation or climatic conditions causing erosion rates at a location to exceed their natural variability. Identifying where and when accelerated erosion occurs is a critical first step toward its effective management. Here we explore how erosion assessments structured in the context of ecological sites (a land classification based on soils, landscape setting and ecological potential) and their vegetation states (plant assemblages that may change due to management) can inform systems for reducing accelerated soil erosion in rangelands. We evaluated aeolian horizontal sediment flux and fluvial sediment erosion rates for five ecological sites in southern New Mexico, USA, using monitoring data and rangeland-specific wind and water erosion models. Across the ecological sites, plots in shrub-encroached and shrub-dominated vegetation states were consistently susceptible to aeolian sediment flux and fluvial sediment erosion. Both processes were found to be highly variable for grassland and grass-succulent states across the ecological sites at the plot scale (0.25 Ha). We identify vegetation thresholds that define cover levels below which rapid (exponential) increases in aeolian sediment flux and fluvial sediment erosion occur across the ecological sites and vegetation states. Aeolian sediment flux and fluvial erosion in the study area can be effectively controlled when bare ground cover is 100 cm in length is less than ~35%. Land use and management activities that alter cover levels such that they cross thresholds, and/or drive vegetation state changes, may increase the susceptibility of areas to erosion. Land use impacts that are constrained within the range of natural variability should not result in accelerated soil erosion. Evaluating land condition against the erosion thresholds identified here will enable identification of areas susceptible to accelerated soil erosion and the development of

  10. Effective Monitoring and Control of Outsourced Software Development Projects

    NASA Astrophysics Data System (ADS)

    Ponisio, Laura; Vruggink, Peter

    In our study of four outsourcing projects we discover mechanisms to support managerial decision making during software development processes. We report on Customer Office, a framework used in practice that facilitates reasoning about projects by highlighting information paths and making co-ordination issues explicit. The results suggest a key role of modularisation and standardisation to assist in value creation, by facilitating information flow and keeping the overview of the project. The practical implications of our findings are guidelines for managing outsourcing projects such as to have a modularised view of the project based on knowledge domains and to standardise co-ordination operations.

  11. Erosion on a line

    NASA Astrophysics Data System (ADS)

    Willett, Sean D.

    2010-03-01

    An erosion model is proposed to calculate erosion rates for plane-strain models in which the Earth's surface is represented on a line. The fundamentals of river erosion networks are captured by two principles, Hack's Law, which describes the drainage area structure of river network and a stream-power erosion law, which describes the rate of incision of a river. For a simple morphology of parallel transverse rivers with rectangular drainage basins, this allows the earth's surface to be parameterized by two heights: the trunk stream channel height and the interfluvial ridge height. The resulting expressions are solved for the simple cases of constant uplift rate and a constant mean slope as occurs in critical wedge problems. In the latter case, the uplift rate is variable and changes in space so that the trunk channel elevation and the interfluvial ridge elevation average to maintain a constant mean slope. A general, numerical solution is presented for application to any numerical model with arbitrary surface velocity, variable rock erodibility and precipitation. This algorithm is coupled to a plane-strain, plastic-deformation model to demonstrate the utility of the model.

  12. Erosion of polyurethane insulation.

    NASA Technical Reports Server (NTRS)

    Kraus, S.

    1973-01-01

    Detailed description of the test program in which erosion of the spray foam insulation used in the S-II stage of the Saturn-V Apollo launch vehicle was investigated. The behavior of the spray foam was investigated at the elevated temperature and static pressure appropriate to the S-II stage environment, but in the absence of the aerodynamic shear stress.

  13. 33 CFR 263.23 - Small flood control project authority (Section 205).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Small flood control project..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.23 Small flood control project authority (Section 205). (a) Legislative authority. Section 205 of the...

  14. 33 CFR 263.23 - Small flood control project authority (Section 205).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Small flood control project..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.23 Small flood control project authority (Section 205). (a) Legislative authority. Section 205 of the...

  15. 33 CFR 263.23 - Small flood control project authority (Section 205).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Small flood control project..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.23 Small flood control project authority (Section 205). (a) Legislative authority. Section 205 of the...

  16. 33 CFR 263.23 - Small flood control project authority (Section 205).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Small flood control project..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.23 Small flood control project authority (Section 205). (a) Legislative authority. Section 205 of the...

  17. 33 CFR 263.23 - Small flood control project authority (Section 205).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Small flood control project..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.23 Small flood control project authority (Section 205). (a) Legislative authority. Section 205 of the...

  18. Project W-320 SAR and process control thermal analyses

    SciTech Connect

    Sathyanarayana, K.

    1997-06-19

    This report summarizes the results of thermal hydraulic computer modeling supporting Project W-320 for process control and SAR documentation. Parametric analyses were performed for the maximum steady state waste temperature. The parameters included heat load distribution, tank heat load, fluffing factor and thermal conductivity. Uncertainties in the fluffing factor and heat load distribution had the largest effect on maximum waste temperature. Safety analyses were performed for off normal events including loss of ventilation, loss of evaporation and loss of secondary chiller. The loss of both the primary and secondary ventilation was found to be the most limiting event with saturation temperature in the bottom waste reaching in just over 30 days. An evaluation was performed for the potential lowering of the supernatant level in tank 241-AY-102. The evaluation included a loss of ventilation and steam bump analysis. The reduced supernatant level decreased the time to reach saturation temperature in the waste for the loss of ventilation by about one week. However, the consequence of a steam bump were dramatically reduced.

  19. Role of projection in the control of bird flocks

    PubMed Central

    Pearce, Daniel J. G.; Miller, Adam M.; Rowlands, George; Turner, Matthew S.

    2014-01-01

    Swarming is a conspicuous behavioral trait observed in bird flocks, fish shoals, insect swarms, and mammal herds. It is thought to improve collective awareness and offer protection from predators. Many current models involve the hypothesis that information coordinating motion is exchanged among neighbors. We argue that such local interactions alone are insufficient to explain the organization of large flocks of birds and that the mechanism for the exchange of long-range information necessary to control their density remains unknown. We show that large flocks self-organize to the maximum density at which a typical individual still can see out of the flock in many directions. Such flocks are marginally opaque—an external observer also still can see a substantial fraction of sky through the flock. Although this seems intuitive, we show it need not be the case; flocks might easily be highly diffuse or entirely opaque. The emergence of marginal opacity strongly constrains how individuals interact with one another within large swarms. It also provides a mechanism for global interactions: an individual can respond to the projection of the flock that it sees. This provides for faster information transfer and hence rapid flock dynamics, another advantage over local models. From a behavioral perspective, it optimizes the information available to each bird while maintaining the protection of a dense, coherent flock. PMID:25002501

  20. The effect of enamel proteins on erosion

    NASA Astrophysics Data System (ADS)

    Baumann, T.; Carvalho, T. S.; Lussi, A.

    2015-10-01

    Enamel proteins form a scaffold for growing hydroxyapatite crystals during enamel formation. They are then almost completely degraded during enamel maturation, resulting in a protein content of only 1% (w/v) in mature enamel. Nevertheless, this small amount of remaining proteins has important effects on the mechanical and structural properties of enamel and on the electrostatic properties of its surface. To analyze how enamel proteins affect tooth erosion, human enamel specimens were deproteinated. Surface microhardness (SMH), surface reflection intensity (SRI) and calcium release of both deproteinated and control specimens were monitored while continuously eroding them. The deproteination itself already reduced the initial SMH and SRI of the enamel significantly (p < 0.001 and p < 0.01). During the course of erosion, the progression of all three evaluated parameters differed significantly between the two groups (p < 0.001 for each). The deproteinated enamel lost its SMH and SRI faster, and released more calcium than the control group, but these differences were only significant at later stages of erosion, where not only surface softening but surface loss can be observed. We conclude that enamel proteins have a significant effect on erosion, protecting the enamel and slowing down the progression of erosion when irreversible surface loss starts to occur.

  1. The effect of enamel proteins on erosion

    PubMed Central

    Baumann, T.; Carvalho, T. S.; Lussi, A.

    2015-01-01

    Enamel proteins form a scaffold for growing hydroxyapatite crystals during enamel formation. They are then almost completely degraded during enamel maturation, resulting in a protein content of only 1% (w/v) in mature enamel. Nevertheless, this small amount of remaining proteins has important effects on the mechanical and structural properties of enamel and on the electrostatic properties of its surface. To analyze how enamel proteins affect tooth erosion, human enamel specimens were deproteinated. Surface microhardness (SMH), surface reflection intensity (SRI) and calcium release of both deproteinated and control specimens were monitored while continuously eroding them. The deproteination itself already reduced the initial SMH and SRI of the enamel significantly (p < 0.001 and p < 0.01). During the course of erosion, the progression of all three evaluated parameters differed significantly between the two groups (p < 0.001 for each). The deproteinated enamel lost its SMH and SRI faster, and released more calcium than the control group, but these differences were only significant at later stages of erosion, where not only surface softening but surface loss can be observed. We conclude that enamel proteins have a significant effect on erosion, protecting the enamel and slowing down the progression of erosion when irreversible surface loss starts to occur. PMID:26468660

  2. Erosion by an Alpine glacier.

    PubMed

    Herman, Frédéric; Beyssac, Olivier; Brughelli, Mattia; Lane, Stuart N; Leprince, Sébastien; Adatte, Thierry; Lin, Jiao Y Y; Avouac, Jean-Philippe; Cox, Simon C

    2015-10-09

    Assessing the impact of glaciation on Earth's surface requires understanding glacial erosion processes. Developing erosion theories is challenging because of the complex nature of the erosion processes and the difficulty of examining the ice/bedrock interface of contemporary glaciers. We demonstrate that the glacial erosion rate is proportional to the ice-sliding velocity squared, by quantifying spatial variations in ice-sliding velocity and the erosion rate of a fast-flowing Alpine glacier. The nonlinear behavior implies a high erosion sensitivity to small variations in topographic slope and precipitation. A nonlinear rate law suggests that abrasion may dominate over other erosion processes in fast-flowing glaciers. It may also explain the wide range of observed glacial erosion rates and, in part, the impact of glaciation on mountainous landscapes during the past few million years.

  3. Erosion by an Alpine glacier

    NASA Astrophysics Data System (ADS)

    Herman, Frédéric; Beyssac, Olivier; Brughelli, Mattia; Lane, Stuart N.; Leprince, Sébastien; Adatte, Thierry; Lin, Jiao Y. Y.; Avouac, Jean-Philippe; Cox, Simon C.

    2015-10-01

    Assessing the impact of glaciation on Earth’s surface requires understanding glacial erosion processes. Developing erosion theories is challenging because of the complex nature of the erosion processes and the difficulty of examining the ice/bedrock interface of contemporary glaciers. We demonstrate that the glacial erosion rate is proportional to the ice-sliding velocity squared, by quantifying spatial variations in ice-sliding velocity and the erosion rate of a fast-flowing Alpine glacier. The nonlinear behavior implies a high erosion sensitivity to small variations in topographic slope and precipitation. A nonlinear rate law suggests that abrasion may dominate over other erosion processes in fast-flowing glaciers. It may also explain the wide range of observed glacial erosion rates and, in part, the impact of glaciation on mountainous landscapes during the past few million years.

  4. Bioengineering applied to erosion and stability control in the North Apennines (Emilia-Romagna Region, Italy): a check about critical aspects of the works.

    NASA Astrophysics Data System (ADS)

    Selli, Lavinia; Cavazza, Claudio; Pavanelli, Donatella

    2013-04-01

    Because of its geological structure, in the Emilia-Romagna Region over 32,000 landslides have been identified. Several works have been made in order to control mass movement's dynamics and to secure of Reno and Lamone Mountain Basin Rivers, the road network and near by villages and towns. Most of the control works dealt with bioengineering practices: palisades piles, geotextiles, seedings, surface flow control works, dikes within main drainage ditches. In order to check about critical aspects related to the use of these techniques in the Apennines, a survey in this basins was designed with specific interest in the several kinds of works realised, in which plant species were mostly used and in the factors that affected the success or failure of the works. Territory encompasses steep slopes covered with woods to low reliefs covered with grasslands. It is characterized by prevailing clays, inducing instability, and arenaceous lithology with impermeable soils; drainage density is quite high and hillsides suffer extensive and severe erosion and slope stability problems. Chestnut woods mainly represent land use at higher altitudes, while coppice, pastures and crops are present on milder hillsides. The remaining part of the basin is covered by vineyards, orchards, ponds and urban areas, which are basically located in the valley floor. Precipitation events mainly consist of rainfall ranging between 950-1015 mm per year; few snowfalls occur during winter and a long dry season lasts from June until September. We have analyzed 187 works designed mainly for the consolidation of slope instabilities through a widespread enhancement of the vegetation cover. The surveyed works are classified as a function of their building features: it can be seen that cribwalls and palisades are by far the most common types, being the 24% and the 34% respectively of the works. As far as the most adopted plant species, they were silver willow (Salix alba), Spanish Broom (Spartium Junceum) and

  5. Control of syntectonic erosion and sedimentation on kinematic evolution of a multidecollement fold and thrust zone: Analogue modeling of folding in the southern subandean of Bolivia

    NASA Astrophysics Data System (ADS)

    Darnault, Romain; Callot, Jean-Paul; Ballard, Jean-François; Fraisse, Guillaume; Mengus, Jean-Marie; Ringenbach, Jean-Claude

    2016-08-01

    Several analogue modeling studies have been conducted during the past fifteen years with the aim to discuss the effects of sedimentation and erosion on Foreland Fold and Thrust Belt, among which a few have analyzed these processes at kilometric scale (Malavieille et al., 1993; Nalpas et al., 1999; Barrier et al., 2002; Pichot and Nalpas, 2009). The influence of syn-deformation sedimentation and erosion on the structural evolution of FFTB has been clearly demonstrated. Here, we propose to go further in this approach by the study of a more complex system with a double decollement level. The natural study case is the Bolivian sub-Andean thrust and fold belt, which present all the required criteria, such as the double decollement level. A set of analogue models performed under a CT-scan have been used to test the influence of several parameters on a fold and thrust belt system, among which: (i) the spatial variation of the sediment input, (ii) the spatial variation of the erosion rate, (iii) the relative distribution of sedimentation between foreland and hinterland. These experiments led to the following observations: 1. The upper decollement level acts as a decoupling level in case of increased sedimentation rate: it results in the verticalization of the shallower part (above the upper decollement level), while the deeper parts are not impacted. 2. Similarly, the increase of the erosion rate involves the uplift of the deeper part (below the upper decollement level), whereas the shallower parts are not impacted. 3. A high sedimentation rate in the foreland involves a fault and fold vergence reversal, followed by a back-thrusting of the shallower part. 4. A high sedimentation rate in the hinterland favours thrust development toward the foreland in the shallower parts.

  6. The economics of tobacco control: evidence from the International Tobacco Control (ITC) Policy Evaluation Project.

    PubMed

    Tauras, John A; Chaloupka, Frank J; Quah, Anne Chiew Kin; Fong, Geoffrey T

    2014-03-01

    Over the past few decades, the importance of economic research in advancing tobacco control policies has become increasingly clear. Extensive research has demonstrated that increasing tobacco taxes and prices is the single most cost-effective tobacco control measure. The research contained in this supplement adds to this evidence and provides new insights into how smokers respond to tax and price changes using the rich data on purchase behaviours, brand choices, tax avoidance and evasion, and tobacco use collected systematically and consistently across countries and over time by the International Tobacco Control (ITC) Project. The findings from this research will help inform policymakers, public health professionals, advocates, and others seeking to maximise the public health and economic benefits from higher taxes.

  7. Guidance and Control Software Project Data - Volume 4: Configuration Management and Quality Assurance Documents

    NASA Technical Reports Server (NTRS)

    Hayhurst, Kelly J. (Editor)

    2008-01-01

    The Guidance and Control Software (GCS) project was the last in a series of software reliability studies conducted at Langley Research Center between 1977 and 1994. The technical results of the GCS project were recorded after the experiment was completed. Some of the support documentation produced as part of the experiment, however, is serving an unexpected role far beyond its original project context. Some of the software used as part of the GCS project was developed to conform to the RTCA/DO-178B software standard, "Software Considerations in Airborne Systems and Equipment Certification," used in the civil aviation industry. That standard requires extensive documentation throughout the software development life cycle, including plans, software requirements, design and source code, verification cases and results, and configuration management and quality control data. The project documentation that includes this information is open for public scrutiny without the legal or safety implications associated with comparable data from an avionics manufacturer. This public availability has afforded an opportunity to use the GCS project documents for DO-178B training. This report provides a brief overview of the GCS project, describes the 4-volume set of documents and the role they are playing in training, and includes configuration management and quality assurance documents from the GCS project. Volume 4 contains six appendices: A. Software Accomplishment Summary for the Guidance and Control Software Project; B. Software Configuration Index for the Guidance and Control Software Project; C. Configuration Management Records for the Guidance and Control Software Project; D. Software Quality Assurance Records for the Guidance and Control Software Project; E. Problem Report for the Pluto Implementation of the Guidance and Control Software Project; and F. Support Documentation Change Reports for the Guidance and Control Software Project.

  8. Discussion of internal erosion modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Internal erosion is one common mode of dam failure. Internal erosion occurs when water flows through a cavity, crack, and/or other continuous opening within the embankment, detaching material. The detachment of material (erosion) results in expansion of the continuous flow path, increased discharg...

  9. Reduction of erosion in elbows due to flow modifications: Final report, Phase 1. [Elbows

    SciTech Connect

    Johnson, E.K.; Means, K.H.; Eyler, R.L.; Holtzworth, J.D.

    1987-11-01

    The objective of this project is to investigate the concept of flow-field modification as a method for reducing erosion in bends (elbows) used in pneumatic transport systems. Flow field modifications were primarily accomplished by injecting air at selected locations within the bends. Part I of this project shows the feasibility of the concept. Part II of this project will include further experiments and analysis, leading to a design methodology for incorporating this concept into piping systems. This report represents the final report for Part I of this project. This report contains a survey of the literature dealing with the erosion in bends (elbows) and the fundamental subjects of erosion and two-phase, gas-solids, flow. Based on this literature survey, a pneumatic transport test loop was constructed. Several bend designs were tested, using sand, under a variety of operating conditions. The results of this exploratory effort indicate that modifying the flow field in a bend with jets may: (1) decrease erosion; (2) change the erosion pattern with the same amount of erosion; or (3) significantly increase the erosion process. Data indicate that the erosion rate may be reduced by low-velocity jets for high phase-density flow. Apparently the interaction of jets with dilute phase-density flow tends to accelerate the erosion process. It is recommended that the project be continued in order to more fully understand the process and its capabilities to solve the difficult technical problem of erosion in bends (elbows).

  10. Soil erosion survey using remote sensing images

    NASA Astrophysics Data System (ADS)

    Jakab, Gergely; Kertész, Ádám; Madarász, Balázs; Pálinkás, Melinda; Tóth, Adrienn

    2016-04-01

    Soil erosion is one of the most effective soil degradation processes reducing crop production on arable fields significantly. It also leads to serious environmental hazards such as eutrophication, mud and flesh floods. Beyond the processes there is an urgent need to survey and descript the current degree of erosion of arable lands in order to provide adequate land use techniques and mitigate the harmful effects. Surveying soil erosion is a very time consuming process since soil loss and deposition take place next to each other resulting a rather diverse erosion pattern even within a plot. Remote sensing is a possible way to determine the degree of soil erosion without special efforts taken in the field. The application of images can provide high resolution erosion maps of almost any type of arable fields. The method is based on the identification of the origin of the surface soil layer, i.e. whether it represents an originally deeper laying horizon (e.g. B horizon), or the parent material. A case study was carried out on a Cambisol formed on loess parent material. The soil and the parent rock have various reflectance spectra in the visible range, so this strip was used for the investigations. For map creation "training sites" were used in ArcMap environment. The obtained results suggest that the method is highly effective and useful, however, other properties like moisture content and plant cover can limit automated application. In this case new training sites are needed. The study was supported by the National Research, Development and Innovation Office (NKFIH),), project Nr. 108755 and the support is gratefully acknowledged here. G. Jakab was supported by the János Bolyai Fellowship.

  11. Illuminating wildfire erosion and deposition patterns with repeat terrestrial lidar

    NASA Astrophysics Data System (ADS)

    Rengers, F. K.; Tucker, G. E.; Moody, J. A.; Ebel, B. A.

    2016-03-01

    Erosion following a wildfire is much greater than background erosion in forests because of wildfire-induced changes to soil erodibility and water infiltration. While many previous studies have documented post-wildfire erosion with point and small plot-scale measurements, the spatial distribution of post-fire erosion patterns at the watershed scale remains largely unexplored. In this study lidar surveys were collected periodically in a small, first-order drainage basin over a period of 2 years following a wildfire. The study site was relatively steep with slopes ranging from 17° to > 30°. During the study period, several different types of rain storms occurred on the site including low-intensity frontal storms (2.4 mm h-1) and high-intensity convective thunderstorms (79 mm h-1). These storms were the dominant drivers of erosion. Erosion resulting from dry ravel and debris flows was notably absent at the site. Successive lidar surveys were subtracted from one another to obtain digital maps of topographic change between surveys. The results show an evolution in geomorphic response, such that the erosional response after rain storms was strongly influenced by the previous erosional events and pre-fire site morphology. Hillslope and channel roughness increased over time, and the watershed armored as coarse cobbles and boulders were exposed. The erosional response was spatially nonuniform; shallow erosion from hillslopes (87% of the study area) contributed 3 times more sediment volume than erosion from convergent areas (13% of the study area). However, the total normalized erosion depth (volume/area) was highest in convergent areas. From a detailed understanding of the spatial locations of erosion, we made inferences regarding the processes driving erosion. It appears that hillslope erosion is controlled by rain splash (for detachment) and overland flow (for transport and quasi-channelized erosion), with the sites of highest erosion corresponding to locations with the

  12. Illuminating wildfire erosion and deposition patterns with repeat terrestrial lidar

    USGS Publications Warehouse

    Rengers, Francis; Tucker, G.E.; Moody, J.A.; Ebel, Brian

    2016-01-01

    Erosion following a wildfire is much greater than background erosion in forests because of wildfire-induced changes to soil erodibility and water infiltration. While many previous studies have documented post-wildfire erosion with point and small plot-scale measurements, the spatial distribution of post-fire erosion patterns at the watershed scale remains largely unexplored. In this study lidar surveys were collected periodically in a small, first-order drainage basin over a period of 2 years following a wildfire. The study site was relatively steep with slopes ranging from 17° to > 30°. During the study period, several different types of rain storms occurred on the site including low-intensity frontal storms (2.4 mm h−1) and high-intensity convective thunderstorms (79 mm h−1). These storms were the dominant drivers of erosion. Erosion resulting from dry ravel and debris flows was notably absent at the site. Successive lidar surveys were subtracted from one another to obtain digital maps of topographic change between surveys. The results show an evolution in geomorphic response, such that the erosional response after rain storms was strongly influenced by the previous erosional events and pre-fire site morphology. Hillslope and channel roughness increased over time, and the watershed armored as coarse cobbles and boulders were exposed. The erosional response was spatially nonuniform; shallow erosion from hillslopes (87% of the study area) contributed 3 times more sediment volume than erosion from convergent areas (13% of the study area). However, the total normalized erosion depth (volume/area) was highest in convergent areas. From a detailed understanding of the spatial locations of erosion, we made inferences regarding the processes driving erosion. It appears that hillslope erosion is controlled by rain splash (for detachment) and overland flow (for transport and quasi-channelized erosion), with the sites of highest erosion corresponding to locations

  13. Highly erodible terrain in agriculture land against chipped pruned branches. Or how to stop the soil erosion with low investment

    NASA Astrophysics Data System (ADS)

    Cerdà, A.

    2009-04-01

    The session on "Soil erosion and sediment control with vegetation and bioengineering on severely eroded terrain" pays special attention to the severe soil erosion suffered on steep slopes and erodible parent materials and soils. Within the last 20 years, in the Mediterranean lands, the citrus orchards were reallocated on steep slopes due to the urban development and better climatic and management conditions of the new plantations. The lack of vegetation cover on the new slope plantations of citrus resulted in high erosion rates. Those non-sustainable soil losses were measured by means of rainfall simulation experiments, Gerlach collectors, geomorphological transect and topographical measurements. The October 2007 and October 2008 rainy periods resulted in sheet, rill and gully erosion. Some recently planted orchards (2005) had the first pruning season in 2008. The pruned chipped branches reduced the soil losses to 50 % of the expected, although the litter (pruned branches) covered 4.67 % of the soil. This is why a research was developed by means of simulated rainfall experiments to determine the vegetation cover (litter, mainly leaves) to protect the soil to reach a sustainable erosion rate. Rainfall simulation experiments at 43 mm h-1 where performed on 1 m2 plots covered with 0, 3, 7, 15, 30, 45, 60, 80 and 100 % litter cover (pruned chipped branches) to determine the sustainable litter cover to avoid the soil losses. The results show that more that 45 % litter cover almost reduces the soil losses to negligible rates. The results confirm that 4 % of vegetation cover reduces the soil losses to 50 %. Key words: Agriculture land, erodible terrain, land management, citrus, erosion, Spain, Valencia, herbicides. Acknowledgements, We thanks the financial support of the Ministerio de Ciencia e Innovación by means of the project CGL2008-02879/BTE, "PERDIDA DE SUELO EN NUEVAS EXPLOTACIONES CITRICOLAS EN PENDIENTE. ESTRATEGIAS PARA EL CONTROL DE LA EROSION HIDRICA"

  14. Infiltration and instability in dune erosion

    NASA Astrophysics Data System (ADS)

    Palmsten, Margaret L.; Holman, Robert A.

    2011-10-01

    Forecasting dune erosion prior to a storm or over longer periods requires knowledge of the fluid forces on the dune sediments. To improve our predictive capability for this process, we propose a new model in which dune slumping occurs when water, which infiltrates horizontally into the dune, increases the overburden sufficiently to destabilize the dune. Horizontal infiltration is driven by suction of water from swash into the dune via capillary action and is a surprisingly strong process with rapid time scales. Because the elevated pore water concentrations increase the apparent cohesion of the wetted sediments, we also propose that the entire volume of wetted sand slumps as a unit when the dune becomes unstable and erosion can be modeled based on the force balance on a sliding block. Several versions of this model were tested, including a numerical infiltration model, a simplified infiltration equation, and an equation based on offshore wave forcing, rather than known forcing at the dune. The model was tested using data from a large-scale laboratory experiment with a storm hydrograph to investigate the time dependence of dune erosion. Predicting slope stability using a numerical infiltration model with known forcing explained 72% of the observed variance in erosion rate, while a simplified stability and infiltration model explained 58%. Error statistics suggest that we captured the majority of the physics controlling dune erosion in this laboratory experiment and that the simplified model will be useful as a forecasting tool.

  15. Requirements management: keeping your technology acquisition project under control.

    PubMed

    Carr, J J

    2000-03-01

    Whether you are acquiring clinical or business information systems, patient monitoring systems, or therapeutic and diagnostic systems, the odds are good that the project will be delivered late, will cost far more than predicted, and will not provide all the features promised. The principal reason for project failure is improper management of the requirements of the system. Requirements engineering and management is a skill from the systems engineering profession that can be learned by nearly any professional who is managing a technology acquisition project. The author discusses what requirements engineering and management is and how it is done.

  16. Modeling Wind Erosion Intermittency

    NASA Astrophysics Data System (ADS)

    Dupont, S.

    2015-12-01

    To improve dust emission schemes in large scale transport models, we developed the first physically-based model simulating the full erosion process in a turbulent flow by resolving explicitly saltating particle trajectories and dust suspension, in presence of vegetation. The large-eddy simulation technic is used here to simulate the turbulent flow, allowing to solve explicitly the main wind gusts near the surface and so the intermittency of the erosion process. The model appeared able to reproduce the saltation intermittency as visualized through the presence of blowing sand structures near the surface, known as aeolian streamers observed on beaches during windy days. In presence of vegetation, the model further allowed us to investigate the sensitivity of sand erosion to the arrangement and morphology of plants (shrubs versus trees). More recently, we further used the model to reanalyze the dependence of the size distribution of the dust flux to the wind speed for idealized erosion events starting from an air free of dust. We found that the suspension of small dust (around 1 μm) can be a long nonstationary process (several hours depending on the wind intensity) due to the low deposition velocity of this particle size range. This leads to a continuous enrichment of the near-surface dust flux in small particles, enrichment that is enhanced with wind intensity, independently of the possible role of saltators. The model also showed that the size distribution and magnitude of dust fluxes at a few meters height differ from those of the emitted flux at the surface as particles start to be sorted through the deposition process within the saltation layer. This last result should be considered when evaluating or calibrating "physically based" dust emission schemes against measured near-surface turbulent diffusive dust fluxes.

  17. Influence of human saliva on the development of artificial erosions.

    PubMed

    Hellwig, E; Lussi, A; Goetz, F

    2013-01-01

    It was hypothesized that saliva from patients with erosion exhibits lower protective efficacy compared to saliva from patients without erosion, based on in vitro enamel softening studies. A total of 645 enamel specimens were distributed among seven experimental groups. Saliva was gathered from each of 10 volunteers without clinical signs of dental erosion and from 10 patients exhibiting severe erosive defects. Aliquots of 50 ml of saliva from each patient were mixed with sour drops or citric acid, respectively. Pooled saliva, sour drops and citric acid mixed with water served as controls. The enamel specimens were soaked in the respective mixture for 5 min and were subsequently incubated in pure saliva for 2 min. This cycle was repeated three times, then the specimens were kept in 100 ml of saliva for 8 h. Surface microhardness was evaluated at the beginning of the experiment and after each cycle. During the experiments, microhardness decreased significantly in all groups except for the pure saliva group. For sour drops and citric acid mixed with saliva from patients without erosion, the final microhardness was higher compared to the mixture of the two erosive compounds with saliva from patients with erosion. The storage of saliva for 8 h resulted in a certain amount of rehardening, with the highest level of rehardening being observed in the group that was least demineralized (sour drops plus saliva from patients without erosion). It is concluded that salivary components play a crucial role in the development of dental erosion.

  18. 33 CFR 203.85 - Rehabilitation of Federal flood control projects.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Rehabilitation of Federal flood... PROCEDURES Local Interests/Cooperation Agreements § 203.85 Rehabilitation of Federal flood control projects. Some sponsors of Federal flood control projects are not required to furnish written assurances of...

  19. 33 CFR 203.85 - Rehabilitation of Federal flood control projects.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Rehabilitation of Federal flood... PROCEDURES Local Interests/Cooperation Agreements § 203.85 Rehabilitation of Federal flood control projects. Some sponsors of Federal flood control projects are not required to furnish written assurances of...

  20. 33 CFR 203.85 - Rehabilitation of Federal flood control projects.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Rehabilitation of Federal flood... PROCEDURES Local Interests/Cooperation Agreements § 203.85 Rehabilitation of Federal flood control projects. Some sponsors of Federal flood control projects are not required to furnish written assurances of...

  1. 33 CFR 203.85 - Rehabilitation of Federal flood control projects.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Rehabilitation of Federal flood... PROCEDURES Local Interests/Cooperation Agreements § 203.85 Rehabilitation of Federal flood control projects. Some sponsors of Federal flood control projects are not required to furnish written assurances of...

  2. 33 CFR 203.85 - Rehabilitation of Federal flood control projects.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Rehabilitation of Federal flood... PROCEDURES Local Interests/Cooperation Agreements § 203.85 Rehabilitation of Federal flood control projects. Some sponsors of Federal flood control projects are not required to furnish written assurances of...

  3. Mechanical Engineering Design Project report: Enabler control systems

    NASA Technical Reports Server (NTRS)

    Cullen, Christian; Delvecchio, Dave; Scarborough, Alan; Havics, Andrew A.

    1992-01-01

    The Controls Group was assigned the responsibility for designing the Enabler's control system. The requirement for the design was that the control system must provide a simple user interface to control the boom articulation joints, chassis articulation joints, and the wheel drive. The system required controlling hydraulic motors on the Enabler by implementing 8-bit microprocessor boards. In addition, feedback to evaluate positions and velocities must be interfaced to provide the operator with confirmation as well as control.

  4. Surface-to-base transfer and subglacial hydrology controls on subglacial erosion evidenced from 7 years of hydro-sedimentary observations within Bossons glacier catchment (Mont-Blanc massif, France)

    NASA Astrophysics Data System (ADS)

    Guillon, Hervé; Mugnier, Jean-Louis; Buoncristiani, Jean-François

    2016-04-01

    . Finally, we focus on subglacial erosion processes by comparing Bossons and Crosette catchments, and analyzing export distribution throughout each melt season. Excluding the case of extreme event, the mean proglacial erosion rate is significantly lower, 0.12±0.10 mm.yr-1, than the mean supraglacial and subglacial erosion rates, 0.86±0.42 and 0.51±0.39 mm.yr-1, respectively. Our results show peaks of sediment export in the middle of the ablation season. Additionnally, uncommon export peaks took place during the late 2010 and 2012 melt season and are not correlated with increase in temperature, melt water runoff or precipitations. These results could indicate the presence of an heterogeneous sediment storage beneath Bossons glacier and abrupt exports related to the evolution of the subglacial drainage system. Furthermore, the calculated glacial erosion rates are 0.41±0.44 and 0.61±0.35 mm.yr-1 for Crosette and Bossons streams, respectively. Such difference could be explained by moulins and bédières efficiently transferring surface sediment and melt water towards glacier base in the lower ablation area drained by Bossons stream but not present in the thickest and steepest parts of glacier drained by Crosette stream. Surface-to-base sediment and water transfer as well as subglacial drainage development may thus significantly control subglacial erosion.

  5. Soil erosion in Iran: Issues and solutions

    NASA Astrophysics Data System (ADS)

    Hamidreza Sadeghi, Seyed; Cerdà, Artemi

    2015-04-01

    Iran currently faces many soil erosion-related problems (see citations below). These issues are resulted from some inherent characteristic and anthropogenic triggering forces. Nowadays, the latter plays more important rule to accelerate the erosion with further emphasis on soil erosion-prone arid and semi arid regions of the country. This contribution attempts to identify and describe the existing main reasons behind accelerated soil erosion in Iran. Appropriate solutions viz. structural and non-structural approaches will be then advised to combat or minimise the problems. Iran can be used as a pilot research site to understand the soil erosion processes in semiarid, arid and mountainous terrain and our research will review the scientific literature and will give an insight of the soil erosion rates in the main factors of the soil erosion in Iran. Key words: Anthropogenic Erosion, Land Degradation; Sediment Management; Sediment Problems Acknowledgements The research projects GL2008-02879/BTE, LEDDRA 243857 and PREVENTING AND REMEDIATING DEGRADATION OF SOILS IN EUROPE THROUGH LAND CARE (RECARE)FP7-ENV-2013- supported this research. References Aghili Nategh, N., Hemmat, A., & Sadeghi, M. (2014). Assessing confined and semi-confined compression curves of highly calcareous remolded soil amended with farmyard manure. Journal of Terramechanics, 53, 75-82. Arekhi, S., Bolourani, A. D., Shabani, A., Fathizad, H., Ahamdy-Asbchin, S. 2012. Mapping Soil Erosion and Sediment Yield Susceptibility using RUSLE, Remote Sensing and GIS (Case study: Cham Gardalan Watershed, Iran). Advances in Environmental Biology, 6(1), 109-124. Arekhi, S., Shabani, A., Rostamizad, G. 2012. Application of the modified universal soil loss equation (MUSLE) in prediction of sediment yield (Case study: Kengir Watershed, Iran). Arabian Journal of Geosciences, 5(6), 1259-1267.Sadeghi, S. H., Moosavi, V., Karami, A., Behnia, N. 2012. Soil erosion assessment and prioritization of affecting factors at plot

  6. A Study of Cavitation Erosion

    SciTech Connect

    Hiromu Isaka; Masatsugu Tsutsumi; Tadashi Shiraishi; Hiroyuki Kobayashi

    2002-07-01

    The authors performed experimental study for the purpose of the following two items from a viewpoint of cavitation erosion of a cylindrical orifice in view of a problem at the letdown orifice in PWR (Pressurized Water Reactor). 1. To get the critical cavitation parameter of the cylindrical orifice to establish the design criteria for prevention of cavitation erosion, and 2. to ascertain the erosion rate in such an eventuality that the cavitation erosion occurs with the orifice made of stainless steel with precipitation hardening (17-4-Cu hardening type stainless steel), so that we confirm the appropriateness of the design criteria. Regarding the 1. item, we carried out the cavitation tests to get the critical cavitation parameters inside and downstream of the orifice. The test results showed that the cavitation parameter at inception is independent of the length or the diameter of the orifice. Moreover, the design criteria of cavitation erosion of cylindrical orifices have been established. Regarding the 2. item, we tested the erosion rate under high-pressure conditions. The cavitation erosion actually occurred in the cylindrical orifice at the tests that was strongly resemble to the erosion occurred at the plant. It will be seldom to reproduce resemble cavitation erosion in a cylindrical orifice with the hard material used at plants. We could establish the criteria for preventing the cavitation erosion from the test results. (authors)

  7. Noise prediction and control of Pudong International Airport expansion project.

    PubMed

    Lei, Bin; Yang, Xin; Yang, Jianguo

    2009-04-01

    The Environmental Impact Assessment (EIA) process of the third runway building project of Pudong International Airport is briefly introduced in the paper. The basic principle, the features, and the operation steps of newly imported FAA's Integrated Noise Model (INM) are discussed for evaluating the aircraft noise impacts. The prediction of the aircraft noise and the countermeasures for the noise mitigation are developed, which includes the reasonable runway location, the optimized land use, the selection of low noise aircrafts, the Fly Quit Program, the relocation of sensitive receptors and the noise insulation of sensitive buildings. Finally, the expansion project is justified and its feasibility is confirmed.

  8. Two Undergraduate Projects for Data Acquisition and Control

    NASA Astrophysics Data System (ADS)

    Hiersche, Kelly; Pena, Tara; Grogan, Tanner; Wright, Matthew

    We are designing two separate instruments for use in our undergraduate laboratory. In the first project, a Raspberry Pi is used to simultaneously monitor a large number of current and voltage readings and store them in a database. In our second project, we are constructing our own microcontrollers to work as a general-purpose interface based off work carried out in Review of Scientific Instruments 84, 103101 (2013). It was designed for low cost and simple construction, making it ideal for undergraduate level work. This circuit has room for two interchangeable daughter boards, giving it the capability to work as a general lab interface, lock-in detector, or waveform generator.

  9. Evaluating soil erodibility dynamics to improve estimates of wind erosion in drylands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind erosion is a key driver of land degradation in the world’s drylands. Soil loss and nutrient decline due to wind erosion increase the sensitivity of drylands to climate stressors. Better understanding the factors controlling wind erosion in drylands will provide a basis for identifying and testi...

  10. Soil Erosion: Advanced Crop and Soil Science. A Course of Study.

    ERIC Educational Resources Information Center

    Miller, Larry E.

    The course of study represents the last of six modules in advanced crop and soil science and introduces the agriculture student to the topic of soil erosion. Upon completion of the two day lesson, the student will be able to: (1) define conservation, (2) understand how erosion takes place, and (3) list ways of controlling wind and water erosion.…

  11. Preventive Planning for Behavior Control: A Project APT Resource Manual.

    ERIC Educational Resources Information Center

    Gendreau, Joan C.; And Others

    One of a series of materials developed by Project APT (Administrators, Parents, and Teachers/Assessment, Programing, and Training), a program designed to foster home/school coordination in educational planning and program implementation for severely mentally retarded and/or multiply handicapped students; the booklet focuses on techniques for…

  12. Skills Conversion Project, Chapter 8, Pollution Control. Final Report.

    ERIC Educational Resources Information Center

    National Society of Professional Engineers, Washington, DC.

    The Skills Conversion Project conducted by the National Society of Professional Engineers sought to study the transition mechanisms required to transfer available technical manpower from aerospace and defense industries into other areas of employment in private industry and public service. Fourteen study teams assessed the likelihood of future…

  13. The environmental control and life support system advanced automation project

    NASA Technical Reports Server (NTRS)

    Dewberry, Brandon S.

    1991-01-01

    The objective of the ECLSS Advanced Automation project includes reduction of the risk associated with the integration of new, beneficial software techniques. Demonstrations of this software to baseline engineering and test personnel will show the benefits of these techniques. The advanced software will be integrated into ground testing and ground support facilities, familiarizing its usage by key personnel.

  14. Towards Greater Learner Control: Web Supported Project-Based Learning

    ERIC Educational Resources Information Center

    Guthrie, Cameron

    2010-01-01

    Project-based learning has been suggested as an appropriate pedagogy to prepare students in information systems for the realities of the business world. Web-based resources have been used to support such pedagogy with mixed results. The paper argues that the design of web-based learning support to cater to different learning styles may give…

  15. Perception of a schistosomiasis control project in rural Kenya by the beneficiaries.

    PubMed

    Katsivo, M N; Muthami, L N; Karama, M; Kingori, F

    1993-10-01

    A schistosomiasis control project was implemented in Mwea Rice Irrigation Scheme in Central Kenya between late 1983 and December 1988 by Kenya Medical Research Institute scientists in collaboration with the National Irrigation Board. The aim of the project was to control schistosomiasis through provision of alternative water sources, bath and laundry units, latrines, chemotherapy and health education. The community participated fully. Five years later in December 1988, 203 household heads were interviewed on their perception of the control project in terms of purpose, project ownership and management, benefits, continuity and their knowledge of schistosomiasis transmission cycle. 61% of the respondents were females and 39% males. 92% of them said that the purpose for the project was to treat, control and prevent bilharzia from spreading, and to promote good health. Slightly over 50% said that the project belonged to them but that they would have liked to be more involved in its management. 74% said that they are able to save time because the facilities are now nearer to them; whilst 79% felt that they were saving money because they did not have to buy drugs since they felt healthier. 99% said that they thought that bilharzia has been controlled, and 82% said that their children looked healthier. 95% said that they could see the project surviving for a long time period suggesting that it was self sustaining and they were willing to start a maintenance of facilities fund. Overall, the community appreciated the social, economic and health benefits derived from the control project.

  16. Wind Erosion in Aeolis

    NASA Technical Reports Server (NTRS)

    2004-01-01

    09 August 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the effects of severe wind erosion of layered sedimentary rock in the Aeolis region of Mars. The sharp ridges formed by wind movement from the lower left (southwest) toward top/upper right (northeast) are known as yardangs. The dark patches in the lower half of the image are sand dunes. This scene is located near 5.0oS, 203.7oW, and covers an area about 3 km (1.9 mi) across. Sunlight illuminates the terrain from the left/upper left.

  17. South Polar Erosion

    NASA Technical Reports Server (NTRS)

    2004-01-01

    24 June 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the results of erosion acting upon a layer of material in the south polar region of Mars. The elliptical pit in the lower left corner of the image was once buried beneath this eroding layer, as well. The processes that eroded the material, and the composition of the material, are unknown. The image is located near 80.7oS, 300.9oW, and covers an area about 3 km (1.9 mi) wide. Sunlight illuminates this scene from the top.

  18. Comparison of WEPP and APEX runoff and erosion prediction at field scale in Goodwater Creek Experimental Watershed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Water Erosion Prediction Project (WEPP) and the Agricultural Policy/Environmental eXtender (APEX) are process-based models that can predict spatial and temporal distributions of erosion for hillslopes and watersheds. This study applies the WEPP model to predict runoff and erosion for a 35-ha fie...

  19. How does slope form affect erosion in CATFLOW-SED?

    NASA Astrophysics Data System (ADS)

    Gabelmann, Petra; Wienhöfer, Jan; Zehe, Erwin

    2016-04-01

    Erosion is a severe environmental problem in agro-ecosystems with highly erodible loess soils. It is controlled by various factors, e.g. rainfall intensity, initial wetness conditions, soil type, land use and tillage practice. Furthermore slope form and gradient have been shown to influence erosion amounts to a large extent. Within the last fifty years, various erosion models have been developed to describe the erosion process, estimate erosion amounts and identify erosion-prone areas. These models differ in terms of complexity, the processes which are considered, and the data required for model calibration and they can be categorised into empirical or statistical, conceptual, and physically-based models. CATFLOW-SED is a process-based hydrology and erosion model that can operate on catchment and hillslope scales. Soil water dynamics are described by the Richards equation including effective approaches for preferential flow. Evapotranspiration is simulated using an approach based on the Penman-Monteith equation. The model simulates overland flow using the diffusion wave equation. Soil detachment is related to the attacking forces of rainfall and overland flow, and the erosion resistance of soil. Sediment transport capacity and sediment deposition are related to overland flow velocity using the equation of Engelund and Hansen and the sinking velocity of grain sizes respectively. We performed a study to analyse the erosion process on different virtual hillslopes, with varying slope gradient and slope form, using the CATFLOW-SED model. We explored the role of landform on erosion and sedimentation, particularly we look for forms that either maximise or minimise erosion. Results indicate the importance to performing the process implementation within physically meaningful limits and choose appropriate model parameters respectively.

  20. Sr-Nd-Os evidence for a stable erosion regime in the Himalaya during the past 12 Myr

    NASA Astrophysics Data System (ADS)

    Galy, Valier; France-Lanord, Christian; Peucker-Ehrenbrink, Bernhard; Huyghe, Pascale

    2010-02-01

    Modern erosion of the Himalaya, the world's largest mountain range, transfers huge dissolved and particulate loads to the ocean. It plays an important role in the long-term global carbon cycle, mostly through enhanced organic carbon burial in the Bengal Fan. To understand the role of past Himalayan erosion, the influence of changing climate and tectonic on erosion must be determined. Here we use a 12 Myr sedimentary record from the distal Bengal Fan (Deep Sea Drilling Project Site 218) to reconstruct the Mio-Pliocene history of Himalayan erosion. We use carbon stable isotopes ( δ13C) of bulk organic matter as paleo-environmental proxy and stratigraphic tool. Multi-isotopic — Sr, Nd and Os — data are used as proxies for the source of the sediments deposited in the Bengal Fan over time. δ13C values of bulk organic matter shift dramatically towards less depleted values, revealing the widespread Late Miocene (ca. 7.4 Ma) expansion of C4 plants in the basin. Sr, Nd and Os isotopic compositions indicate a rather stable erosion pattern in the Himalaya range during the past 12 Myr. This supports the existence of a strong connection between the southern Tibetan plateau and the Bengal Fan. The tectonic evolution of the Himalaya range and Southern Tibet seems to have been unable to produce large re-organisation of the drainage system. Moreover, our data do not suggest a rapid change of the altitude of the southern Tibetan plateau during the past 12 Myr. Variations in Sr and Nd isotopic compositions around the late Miocene expansion of C4 plants are suggestive of a relative increase in the erosion of High Himalaya Crystalline rock (i.e. a simultaneous reduction of both Transhimalayan batholiths and Lesser Himalaya relative contributions). This could be related to an increase in aridity as suggested by the ecological and sedimentological changes at that time. A reversed trend in Sr and Nd isotopic compositions is observed at the Plio-Pleistocene transition that is likely

  1. An application of mathematical models to select the optimal alternative for an integral plan to desertification and erosion control (Chaco Area - Salta Province - Argentina)

    NASA Astrophysics Data System (ADS)

    Grau, J. B.; Antón, J. M.; Tarquis, A. M.; Colombo, F.; de Los Ríos, L.; Cisneros, J. M.

    2010-11-01

    Multi-criteria Decision Analysis (MCDA) is concerned with identifying the values, uncertainties and other issues relevant in a given decision, its rationality, and the resulting optimal decision. These decisions are difficult because the complexity of the system or because of determining the optimal situation or behaviour. This work will illustrate how MCDA is applied in practice to a complex problem to resolve such us soil erosion and degradation. Desertification is a global problem and recently it has been studied in several forums as ONU that literally says: "Desertification has a very high incidence in the environmental and food security, socioeconomic stability and world sustained development". Desertification is the soil quality loss and one of FAO's most important preoccupations as hunger in the world is increasing. Multiple factors are involved of diverse nature related to: natural phenomena (water and wind erosion), human activities linked to soil and water management, and others not related to the former. In the whole world this problem exists, but its effects and solutions are different. It is necessary to take into account economical, environmental, cultural and sociological criteria. A multi-criteria model to select among different alternatives to prepare an integral plan to ameliorate or/and solve this problem in each area has been elaborated taking in account eight criteria and five alternatives. Six sub zones have been established following previous studies and in each one the initial matrix and weights have been defined to apply on different criteria. Three multicriteria decision methods have been used for the different sub zones: ELECTRE, PROMETHEE and AHP. The results show a high level of consistency among the three different multicriteria methods despite the complexity of the system studied. The methods are fully described for La Estrella sub zone, indicating election of weights, Initial Matrixes, algorithms used for PROMETHEE, and the Graph of

  2. Reprint of: Assessment of the use of sediment fences for control of erosion and sediment phosphorus loss after potato harvesting on sloping land.

    PubMed

    Vinten, A J A; Loades, K; Addy, S; Richards, S; Stutter, M; Cook, Y; Watson, H; Taylor, C; Abel, C; Baggaley, N; Ritchie, R; Jeffrey, W

    2014-01-15

    In humid temperate areas, after harvest of potatoes, it is difficult to prevent soil erosion and diffuse pollution. In some autumn weather conditions, in-field mitigation such as cultivation or sowing are not possible, while edge of field measures can be costly and inflexible. We have assessed the potential of modified sediment fences, widely used on building sites, for erosion mitigation post-harvest of potato crops. Field scale assessments were conducted on fields in the Lunan catchment, eastern Scotland. Sediment retention was estimated by two methods: a topographic survey method using a hand held Real Time Kinematic Global Positioning System (RTK-GPS), and direct measurement of sediment depth using a graduated cane. In the 2010/11 trial the main fence comprised 70 m of entrenched fine mesh (0.25 mm) and coarser mesh (4mm) fabric pinned to a contour fence near the base of the field. This retained an estimated 50.9 m(3) (80.2 tonnes) of sediment, with weighted mean total P (TP) content of 0.09 % in the<2mm soil fraction. In the 2011/12 trial, the main 146 m fence was of intermediate mesh size (1.2mm). The fence was partitioned into nine upslope plots, with 3 replicates of each of 3 cultivation methods: T1 (full grubbing--a light, tined cultivator), T2 (partial grubbing) and T3 (no grubbing). Average plot slopes ranged from 9.9 to 11.0 %. The amounts of TP accumulating as sediment at the fences were: 9.3 (sd=7.8), 11.8 (sd=10.2) and 25.7 (sd=5.8)kg P/ha of upslope plot for the T1, T2 and T3 treatments respectively.

  3. Assessment of the use of sediment fences for control of erosion and sediment phosphorus loss after potato harvesting on sloping land.

    PubMed

    Vinten, A J A; Loades, K; Addy, S; Richards, S; Stutter, M; Cook, Y; Watson, H; Taylor, C; Abel, C; Baggaley, N; Ritchie, R; Jeffrey, W

    2014-01-15

    In humid temperate areas, after harvest of potatoes, it is difficult to prevent soil erosion and diffuse pollution. In some autumn weather conditions, in-field mitigation such as cultivation or sowing are not possible, while edge of field measures can be costly and inflexible. We have assessed the potential of modified sediment fences, widely used on building sites, for erosion mitigation post-harvest of potato crops. Field scale assessments were conducted on fields in the Lunan catchment, eastern Scotland. Sediment retention was estimated by two methods: a topographic survey method using a hand held Real Time Kinematic Global Positioning System (RTK-GPS), and direct measurement of sediment depth using a graduated cane. In the 2010/11 trial the main fence comprised 70 m of entrenched fine mesh (0.25 mm) and coarser mesh (4mm) fabric pinned to a contour fence near the base of the field. This retained an estimated 50.9 m(3) (80.2 tonnes) of sediment, with weighted mean total P (TP) content of 0.09 % in the<2mm soil fraction. In the 2011/12 trial, the main 146 m fence was of intermediate mesh size (1.2mm). The fence was partitioned into nine upslope plots, with 3 replicates of each of 3 cultivation methods: T1 (full grubbing--a light, tined cultivator), T2 (partial grubbing) and T3 (no grubbing). Average plot slopes ranged from 9.9 to 11.0 %. The amounts of TP accumulating as sediment at the fences were: 9.3 (sd = 7.8), 11.8 (sd = 10.2) and 25.7 (sd = 5.8)kg P/ha of upslope plot for the T1, T2 and T3 treatments respectively.

  4. Low frequency cavitation erosion

    NASA Astrophysics Data System (ADS)

    Pardue, Sally J.; Chandekar, Gautam

    2002-11-01

    Damage of diesel engine piston sleeve liners due to cavitation of the coolant fluid can be severe. Coolant fluid additives are used to inhibit cavitation damage, and are evaluated by industry suppliers using ASTM G32-98 Standard Test Method for Cavitation Erosion Using Vibratory Apparatus. The ASTM G32-98 test procedure uses an ultrasonic horn at 20 kHz to vibrate a test button in the coolant. The test button mass loss and surface appearance are studied to sort the performance of new coolant additives. Mismatch between good lab performers and actual engine test runs has raised concerns over the current lab test. The frequency range of the current test has been targeted for investigation. A low frequency, less than 2000 Hz, test rig was built to explore the cavitation damage. The test system did produce cavitation on the surface of the test button for a period of 36 h, with minimal mass loss. The test rig experienced cyclic fatigue when test times were extended. The work is now focusing on designing a better test rig for long duration tests and on developing numerical models in order to explore the effects of cavitation excitation frequency on surface erosion.

  5. Soil erosion from two small construction sites, Dane County, Wisconsin

    USGS Publications Warehouse

    Owens, David W.; Jopke, Peter; Hall, David W.; Balousek, Jeremy; Roa, Aicardo

    2000-01-01

    Soil erosion from construction sites has long been identified as a significant source of sediment and other suspended solids in runoff in many parts of the United States (Hagman and others, 1980; Yorke and Herb, 1976: Becker and others, 1974). In some states, such as Wisconsin, sediment has been identified as the number one pollutant (by volume) of surface waters (Wisconsin Depart- ment of Natural Resources, 1994). Because numerous water-quality problems in streams are associated with excessive sedimentation, Federal and state regulations requiring erosion-control measures at construction sites larger than 5 acres have been developed and implemented from the 1970's to the present. During the 1990's, excessive erosion and sediment production associated with small residential and commercial sites of less than 5 acres has been increasingly recognized for its effects on streams not only erosion from individual sites but also erosion from discontinuous groups of sites within a stream basin.

  6. The Monitoring Erosion of Agricultural Land and spatial database of erosion events

    NASA Astrophysics Data System (ADS)

    Kapicka, Jiri; Zizala, Daniel

    2013-04-01

    In 2011 originated in The Czech Republic The Monitoring Erosion of Agricultural Land as joint project of State Land Office (SLO) and Research Institute for Soil and Water Conservation (RISWC). The aim of the project is collecting and record keeping information about erosion events on agricultural land and their evaluation. The main idea is a creation of a spatial database that will be source of data and information for evaluation and modeling erosion process, for proposal of preventive measures and measures to reduce negative impacts of erosion events. A subject of monitoring is the manifestations of water erosion, wind erosion and slope deformation in which cause damaged agriculture land. A website, available on http://me.vumop.cz, is used as a tool for keeping and browsing information about monitored events. SLO employees carry out record keeping. RISWC is specialist institute in the Monitoring Erosion of Agricultural Land that performs keeping the spatial database, running the website, managing the record keeping of events, analysis the cause of origins events and statistical evaluations of keeping events and proposed measures. Records are inserted into the database using the user interface of the website which has map server as a component. Website is based on database technology PostgreSQL with superstructure PostGIS and MapServer UMN. Each record is in the database spatial localized by a drawing and it contains description information about character of event (data, situation description etc.) then there are recorded information about land cover and about grown crops. A part of database is photodocumentation which is taken in field reconnaissance which is performed within two days after notify of event. Another part of database are information about precipitations from accessible precipitation gauges. Website allows to do simple spatial analysis as are area calculation, slope calculation, percentage representation of GAEC etc.. Database structure was designed

  7. [The Southern Cone Sub-Regional Project on Cystic Echinococcosis Control and Surveillance].

    PubMed

    Irabedra, Pilar; Salvatella, Roberto

    2010-01-01

    Southern Cone Sub-Regional Project on Cystic Echinococcosis Control and Surveillance: Argentina, Brasil, Chile and Uruguay, is a joint and collaborative tool with the aim of promoting the implementation or the strengthening of programs for disease control. The paper describes the background, the institutional aspects that regulates the structure and functions, as well as the guidelines defined in the technical and operational project. The article emphasize the achievements through Projects of Technical Cooperation among Countries, and the development of integrated and innovative approaches for prevention and control of the disease and training of human resources of the control programs. Some of the challenges are: to achieve the sustainability of the project, implementation of technical groups for analysis and assessment at request of the countries, improvement of the regional information systems, to continue training human resources of the control programs and to expand and strengthen the technical cooperation among countries.

  8. Critical issues in process control system security : DHS spares project.

    SciTech Connect

    Hernandez, Jacquelynne; McIntyre, Annie; Henrie, Morgan

    2010-10-01

    The goals of this event are: (1) Discuss the next-generation issues and emerging risks in cyber security for control systems; (2) Review and discuss common control system architectures; (3) Discuss the role of policy, standards, and supply chain issues; (4) Interact to determine the most pertinent risks and most critical areas of the architecture; and (5) Merge feedback from Control System Managers, Engineers, IT, and Auditors.

  9. Soil erosion, policy and management in China coastal zone

    NASA Astrophysics Data System (ADS)

    Lu, Qingshui; Gao, Zhiqiang; Chen, Qiao; Ning, Jicai; Shi, Runhe; Gao, Wei

    2013-09-01

    The coastal zone is very important in the world. China coastal zone was granted the first priority of developing economy in the late 1980s. Since then, high population density and rapid economic development hace caused intensive changes of LUCC in this zone. Those changes have lead to land degradation. Besides, China governments launched series of projects and policy to improve such problems. Those will inevitably cause to diverse spatial dynamics of land degradtion. However, the state of land degradation in certain time is still unknown. Soil erosion is an important indicator of land degradation.Therefore, we use RS images,RUSLE model to anlyze the spatial pattern of soil erosion for 2000. By spatial analysis, we found that soil erosion in China coastal zone is not serious. Widespread soil erosion is only occurred on coastal zones in Shandong, Hainan and werstern Guangdong Province. Although rainfall eosivity factor(R) is higher in southern coastal zone, erosion tends to occur on the slopes with lower LS values in northern coastal zone than southern coastal zone. Goevernments have enforced some policy to reduce the extent of soil erosion by conversion of farmland to woodland and barren mountains to woodland. But the difference between southern and northern coastal zone is still not realized. To improve soil eorosion in those areas, we should let governments put more funds to increase vegetation cover in north. Such study will provide helpful suggestions for governments to prevent soil erosion in coastal zone.

  10. Geoinformation mapping of soil erosion in the Middle Volga region

    NASA Astrophysics Data System (ADS)

    Yermolaev, O. P.

    2017-01-01

    The results of a medium-scale geoinformation mapping of soil erosion on an area of about 150000 km2 in the Middle Volga region are analyzed using the catchment-based approach. A quantitative index of the development of soil erosion on the agricultural lands is suggested. It reflects the intensity of soil erosion on slopes within the river catchments. A computer-based vector map of the boundaries of 3331 elementary catchments has been developed. It represents the territorial units for the analysis of soil erosion. Archive materials from the former institutes for land survey have been used to compile a series of the maps of soil erosion in river catchments on a scale of 1: 200000. The zoning of erosional processes has been performed, and the natural and anthropogenic levels of soil erosion in different basins have been estimated. The analysis of these materials shows that the topography and agricultural activity of humans are the major factors controlling the development of erosion. The maximum development of soil erosion in the studied region is typical of the subzone of broadleaved forests.

  11. Comparison of Erosion Rates Estimated by Sediment Budget Techniques and Suspended Sediment Monitoring and Regulatory Implications

    NASA Astrophysics Data System (ADS)

    O'Connor, M.; Eads, R.

    2007-12-01

    Watersheds in the northern California Coast Range have been designated as "impaired" with respect to water quality because of excessive sediment loads and/or high water temperature. Sediment budget techniques have typically been used by regulatory authorities to estimate current erosion rates and to develop targets for future desired erosion rates. This study examines erosion rates estimated by various methods for portions of the Gualala River watershed, designated as having water quality impaired by sediment under provisions of the Clean Water Act Section 303(d), located in northwest Sonoma County (~90 miles north of San Francisco). The watershed is underlain by Jurassic age sedimentary and meta-sedimentary rocks of the Franciscan formation. The San Andreas Fault passes through the western edge of watershed, and other active faults are present. A substantial portion of the watershed is mantled by rock slides and earth flows, many of which are considered dormant. The Coast Range is geologically young, and rapid rates of uplift are believed to have contributed to high erosion rates. This study compares quantitative erosion rate estimates developed at different spatial and temporal scales. It is motivated by a proposed vineyard development project in the watershed, and the need to document conditions in the project area, assess project environmental impacts and meet regulatory requirements pertaining to water quality. Erosion rate estimates were previously developed using sediment budget techniques for relatively large drainage areas (~100 to 1,000 km2) by the North Coast Regional Water Quality Control Board and US EPA and by the California Geological Survey. In this study, similar sediment budget techniques were used for smaller watersheds (~3 to 8 km2), and were supplemented by a suspended sediment monitoring program utilizing Turbidity Threshold Sampling techniques (as described in a companion study in this session). The duration of the monitoring program to date

  12. Lake Darling Flood Control Project, Souris River, North Dakota. General Project Design.

    DTIC Science & Technology

    1983-06-01

    earth dams, cover much of the valley floor. Lake Darling is the largest, extending from the southern boundary of Renville County, North Dakota, to...valley reach extending north from the southwestern limit of the glacial Lake Souris area is very shallow, but downstream from Upham the valley...project extends from Upham downstream to the international bound- ary and provides for ponding water behind a series of five low dams. 16. The refuges

  13. Design Project on Controlled-Release Drug Delivery Devices: Implementation, Management, and Learning Experiences

    ERIC Educational Resources Information Center

    Xu, Qingxing; Liang, Youyun; Tong, Yen Wah; Wang, Chi-Hwa

    2010-01-01

    A design project that focuses on the subject of controlled-release drug delivery devices is presented for use in an undergraduate course on mass transfer. The purpose of the project is to introduce students to the various technologies used in the fabrication of drug delivery systems and provide a practical design exercise for understanding the…

  14. Advanced Ground Systems Maintenance Cryogenics Test Lab Control System Upgrade Project

    NASA Technical Reports Server (NTRS)

    Harp, Janice Leshay

    2014-01-01

    This project will outfit the Simulated Propellant Loading System (SPLS) at KSC's Cryogenics Test Laboratory with a new programmable logic control system. The control system upgrade enables the Advanced Ground Systems Maintenace Element Integration Team and other users of the SPLS to conduct testing in a controls environment similar to that used at the launch pad.

  15. Development of a statistical model for the determination of the probability of riverbank erosion in a Meditteranean river basin

    NASA Astrophysics Data System (ADS)

    Varouchakis, Emmanouil; Kourgialas, Nektarios; Karatzas, George; Giannakis, Georgios; Lilli, Maria; Nikolaidis, Nikolaos

    2014-05-01

    the independent variables tested (Atkinson et al. 2003). The developed statistical model is applied to the Koiliaris River Basin in the island of Crete, Greece. The aim is to determine the probability of erosion along the Koiliaris' riverbanks considering a series of independent geomorphological and/or hydrological variables. Data for the river bank slope and for the river cross section width are available at ten locations along the river. The riverbank has indications of erosion at six of the ten locations while four has remained stable. Based on a recent work, measurements for the two independent variables and data regarding bank stability are available at eight different locations along the river. These locations were used as validation points for the proposed statistical model. The results show a very close agreement between the observed erosion indications and the statistical model as the probability of erosion was accurately predicted at seven out of the eight locations. The next step is to apply the model at more locations along the riverbanks. In November 2013, stakes were inserted at selected locations in order to be able to identify the presence or absence of erosion after the winter period. In April 2014 the presence or absence of erosion will be identified and the model results will be compared to the field data. Our intent is to extend the model by increasing the number of independent variables in order to indentify the key factors favouring erosion along the Koiliaris River. We aim at developing an easy to use statistical tool that will provide a quantified measure of the erosion probability along the riverbanks, which could consequently be used to prevent erosion and flooding events. Atkinson, P. M., German, S. E., Sear, D. A. and Clark, M. J. 2003. Exploring the relations between riverbank erosion and geomorphological controls using geographically weighted logistic regression. Geographical Analysis, 35 (1), 58-82. Luppi, L., Rinaldi, M., Teruggi, L. B

  16. Integrated Resilient Aircraft Control Project Full Scale Flight Validation

    NASA Technical Reports Server (NTRS)

    Bosworth, John T.

    2009-01-01

    Objective: Provide validation of adaptive control law concepts through full scale flight evaluation. Technical Approach: a) Engage failure mode - destabilizing or frozen surface. b) Perform formation flight and air-to-air tracking tasks. Evaluate adaptive algorithm: a) Stability metrics. b) Model following metrics. Full scale flight testing provides an ability to validate different adaptive flight control approaches. Full scale flight testing adds credence to NASA's research efforts. A sustained research effort is required to remove the road blocks and provide adaptive control as a viable design solution for increased aircraft resilience.

  17. Physical modeling and monitoring of the process of thermal-erosion of an ice-wedge during a partially-controlled field experiment (Bylot Island, NU, Canada)

    NASA Astrophysics Data System (ADS)

    Godin, E.; Fortier, D.

    2013-12-01

    Syngenetic ice-wedges polygons are widespread periglacial features of the Arctic. On Bylot Island, Nunavut, Canada, numerous thermo-erosion gullies up to several 100's m in length developed in polygonal wetlands during the last decades. These gullies contributed to drainage of these wetlands and changed dramatically local ecological conditions. Concentrated and repeated snowmelt surface runoff infiltrated frost cracks, where convective heat transfer between flowing water and ice initiated piping in ice wedges leading to the rapid development of tunnels and gullies in the permafrost (Fortier D. et al., 2007). We conducted field experiments to quantify the convection process and speed of ice wedges ablation. The experiments were accomplished between the 23/06/2013 and the 05/07/2013 over A; an exposed sub-horizontal ice-wedge surface and B; a tunnel in an ice-wedge crack. The ice was instrumented with graduated sticks to calculate the ice ablation following the flow of a defined amount of water. A fixed quantity of water obtained from a nearby waterfall was diverted over the ice through a PVC pipe. Water temperature Wt (K), quantity Wq (L s-1 or m3 s-1), ice ablation rate Iar (m s-1) and convective heat transfer coefficient α (W m-2 K) were obtained during the 5 experiments. The objective of this paper is to quantify the heat transfer process from field measurements from an ice wedge under ablation and to compare with coefficients from previous researches and in the literature. For each experiment with the ice-surface scenario, water temperature varied between 280 K and 284 K. Discharge varied between 0.0001 and 0.0003 m3 s-1. Ablation rate varied between 1.8 * 10-5 and 0.0004 m s-1. Heat transfer coefficient varied between 706 and 11 655 W m-2 K and between 54 and 4802 W of heat was transferred to ice. For each experiment with the tunnel scenario, water temperature was 284 K × 1 K. Discharge was 0.0002 m3 s-1. Ablation rate varied between 0.0001 and 0.0003 m s-1

  18. [Project summarize of "reestablishing disease prevention and control system of China"].

    PubMed

    Hao, Mo; Yu, Jingjin; Yu, Mingzhu; Duan, Yong

    2005-01-01

    This paper introduced the project of "reestablishing the disease control and prevention system of China" in brief, including background, objectives, funding resources, researching objects and sampling methods. This project which funded by National Outstanding Younger Fund and the research fund of MOH aimed at nailing down the key problem existed in disease control and prevention system of China, demonstrating the reasons and mechanism of key problem, developing feasible policy idea and strategy. This paper also introduced some issues concerning the reestablishing of the disease control and prevention system of China: the definition of public function, the standard of human resource allocation and the standard of financing. The Centers for Disease Control and Prevention in 8 provinces, 80 cities and 80 counties have been sampled to provide information that project needed. In addition, this project also cited some data which come from the early study, in which 3 provinces, 12 counties, 49 towns, 179 villages and 9781 rural families have been sampled and investigated.

  19. Control Systems for Information Systems Development Projects (Part I)

    ERIC Educational Resources Information Center

    Dickson, Gary W.

    1970-01-01

    Discusses control of management information systems and finds a similarity in management of research and development activity. Part II will appear in AEDS Journal, Volume 4, number 2, December 1970. (JF)

  20. Mathematical model to select the optimal alternative for an integral plan to desertification and erosion control for the Chaco Area in Salta Province (Argentine)

    NASA Astrophysics Data System (ADS)

    Grau, J. B.; Anton, J. M.; Tarquis, A. M.; Colombo, F.; de Los Rios, L.; Cisneros, J. M.

    2010-04-01

    Multi-criteria Decision Analysis (MCDA) is concerned with identifying the values, uncertainties and other issues relevant in a given decision, its rationality, and the resulting optimal decision. These decisions are difficult because the complexity of the system or because of determining the optimal situation or behavior. This work will illustrate how MCDA is applied in practice to a complex problem to resolve such us soil erosion and degradation. Desertification is a global problem and recently it has been studied in several forums as ONU that literally says: "Desertification has a very high incidence in the environmental and food security, socioeconomic stability and world sustained development". Desertification is the soil quality loss and one of FAO's most important preoccupations as hunger in the world is increasing. Multiple factors are involved of diverse nature related to: natural phenomena (water and wind erosion), human activities linked to soil and water management, and others not related to the former. In the whole world this problem exists, but its effects and solutions are different. It is necessary to take into account economical, environmental, cultural and sociological criteria. A multi-criteria model to select among different alternatives to prepare an integral plan to ameliorate or/and solve this problem in each area has been elaborated taking in account eight criteria and six alternatives. Six sub zones have been established following previous studies and in each one the initial matrix and weights have been defined to apply on different criteria. Three Multicriteria Decision Methods have been used for the different sub zones: ELECTRE, PROMETHEE and AHP. The results show a high level of consistency among the three different multicriteria methods despite the complexity of the system studied. The methods are described for La Estrella sub zone, indicating election of weights, Initial Matrixes, the MATHCAD8 algorithms used for PROMETHEE, and the

  1. Erosion by Wind: Environmental Effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind erosion is the movement and loss of soil resulting from the interaction of a bare, loose, dry soil surface with wind. Wind erosion is a soil degrading process that reduces soil productivity, damages crops, and may, in extreme cases, result in burial of fertile soil horizons and structures. Th...

  2. Model of beam head erosion

    SciTech Connect

    Lee, E.P.

    1980-08-08

    An analytical model of beam head dynamics is presented, leading to an estimate of the erosion rate due to the combined effects of Ohmic dissipation and scattering. Agreement with the results of a computer simulation and detailed one-dimensional computations is good in all respects except for the scaling of the erosion rate with net current.

  3. SST Control by Subsurface Mixing during Indian Ocean Monsoons: 1-yr Pilot Project

    DTIC Science & Technology

    2013-09-30

    public release; distribution is unlimited. SST Control by Subsurface Mixing during Indian Ocean Monsoons : 1-yr Pilot Project Emily Shroyer and James...observational basis and physical interpretation for new mixing parameterizations that will contribute to improved monsoon predictions in this sensitive...4. TITLE AND SUBTITLE SST Control by Subsurface Mixing during Indian Ocean Monsoons : 1-yr Pilot Project 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

  4. Limited-angle holographic tomography with optically controlled projection generation

    NASA Astrophysics Data System (ADS)

    Kuś, A.; Krauze, W.; Kujawińska, M.

    2015-03-01

    In the paper we demonstrate a holographic tomography system with limited angle of projections, realized by optical- only, diffraction-based beam steering. The system created for this purpose is a Mach-Zehnder interferometer modified to serve as a digital holographic microscope with high Numerical Aperture illumination module and a Spatial Light Modulator. Such solution is fast and robust. Apart from providing an elegant solution to the viewing angle shifting, it also adds new capabilities of the holographic microscope system. SLM, being an active optical element, allows wavefront correction in order to improve measurement accuracy. Integrated phase data captured with different scenarios within a highly limited angular range are processed by a new tomographic reconstruction algorithm based on the compressed sensing technique: total variation minimization, which is applied to non-piecewise constant samples. Finally, the accuracy of full measurement and processing path proposed is tested for a calibrated 3D microobject.

  5. Toward integrated opisthorchiasis control in northeast Thailand: the Lawa project.

    PubMed

    Sripa, Banchob; Tangkawattana, Sirikachorn; Laha, Thewarach; Kaewkes, Sasithorn; Mallory, Frank F; Smith, John F; Wilcox, Bruce A

    2015-01-01

    Human liver fluke, Opisthorchis viverrini, a food-borne trematode is a significant public health problem in Southeast Asia, particularly in Thailand. Despite a long history of control programmes in Thailand and a nationwide reduction, O. viverrini infection prevalence remains high in the northeastern provinces. Therefore, a new strategy for controlling the liver fluke infection using the EcoHealth/One Health approach was introduced into the Lawa Lake area in Khon Kaen province where the liver fluke is endemic. A programme has been carried using anthelminthic treatment, novel intensive health education methods both in the communities and in schools, ecosystem monitoring and active community participation. As a result, the infection rate in the more than 10 villages surrounding the lake has declined to approximate one third of the average of 50% as estimated by a baseline survey. Strikingly, the Cyprinoid fish species in the lake, which are the intermediate host, now showed less than 1% prevalence compared to a maximum of 70% at baseline. This liver fluke control programme, named "Lawa model," is now recognised nationally and internationally, and being expanding to other parts of Thailand and neighbouring Mekong countries. Challenges to O. viverrini disease control, and lessons learned in developing an integrative control programme using a community-based, ecosystem approach, and scaling-up regionally based on Lawa as a model are described.

  6. Toward integrated opisthorchiasis control in Northeast Thailand: The Lawa Project

    PubMed Central

    Sripa, Banchob; Tangkawattana, Sirikachorn; Laha, Thewarach; Kaewkes, Sasithorn; Mallory, Frank F.; Smith, John F.; Wilcox, Bruce A.

    2015-01-01

    Human liver fluke, Opisthorchis viverrini, a food-borne trematode is a significant public health problem in Southeast Asia, particularly in Thailand. Despite a long history of control programs in Thailand and a nationwide reduction, O. viverrini infection prevalence remains high in the Northeastern Provinces. Therefore, a new strategy for controlling the liver fluke infection using the EcoHealth/One Health approach was introduced into the Lawa Lake area in Khon Kaen province where the liver fluke is endemic. A program has been carried using anthelminthic treatment, novel intensive health education methods both in the communities and in schools, ecosystem monitoring and active community participation. As a result, the infection rate in the more than 10 villages surrounding the Lake has declined to approximate one third of the average of 50% as estimated by a baseline survey. Strikingly, the Cyprinoid fish species in the Lake, which are the intermediate host, now showed less than 1% prevalence compared to a maximum of 70% at baseline. This liver fluke control program, named “Lawa model,” is now recognized nationally and internationally, and being expanding to other parts of Thailand and neighboring Mekong countries. Challenges to O. viverrini disease control, and lessons learned in developing an integrative control program using a community-based, ecosystem approach, and scaling-up regionally based on Lawa as a model are described. PMID:25102053

  7. Experiments for understanding soil erosion processes

    NASA Astrophysics Data System (ADS)

    Seeger, Manuel

    2015-04-01

    Soil erosion processes are usually quantified by observation and measurement of their related forms. Rill, and gullies, moulds or sediment sinks are often used to estimate the soil loss. These forms are generally related directly to different types of processes, thus are also used to identify the dominant processes on a certain type of land-use. Nevertheless, the direct observation of erosion processes is constrained by their temporal and spatial erratic occurrence. As a consequence, the process understanding is generally deduced by analogies. Another possibility is to reproduce processes in experiments in both, the lab and in the field. Laboratory experiments are implemented when we want to have full control over all parameters we think are relevant for the process in our focus. So are very useful for identification of parameters influencing processes and their intensities, but also as physical models of the processes and process interactions in our focus. Therefore, we can use them to verify our concepts, and to define relevant parameters. Field experiments generally only simulate with controlled driving forces, this is the rain or the runoff, but dealing with the uncertainty of our study object, the soil. This enables two things: 1) similar as with lab experiments, we are able to identify processes and process interactions and so, to get a deeper understanding of soil erosion; 2) experiments are suitable for providing data about singular processes in the field and thus, to provide data suitable for model parametrisation and calibration. These may be quantitative data about erodibility or soil resistance, sediment detachment or transport. The Physical Geography Group at Trier University has a long lasting experience in the application of experiments in soil erosion research in the field, and has become lead in the further development conception and of devices and procedures to investigate splash detachment and initial transport of soil particles by wind and water

  8. A revealed preference approach to estimating supply curves for ecosystem services: use of auctions to set payments for soil erosion control in Indonesia.

    PubMed

    Jack, B Kelsey; Leimona, Beria; Ferraro, Paul J

    2009-04-01

    To supply ecosystem services, private landholders incur costs. Knowledge of these costs is critical for the design of conservation-payment programs. Estimating these costs accurately is difficult because the minimum acceptable payment to a potential supplier is private information. We describe how an auction of payment contracts can be designed to elicit this information during the design phase of a conservation-payment program. With an estimate of the ecosystem-service supply curve from a pilot auction, conservation planners can explore the financial, ecological, and socioeconomic consequences of alternative scaled-up programs. We demonstrate the potential of our approach in Indonesia, where soil erosion on coffee farms generates downstream ecological and economic costs. Bid data from a small-scale, uniform-price auction for soil-conservation contracts allowed estimates of the costs of a scaled-up program, the gain from integrating biophysical and economic data to target contracts, and the trade-offs between poverty alleviation and supply of ecosystem services. Our study illustrates an auction-based approach to revealing private information about the costs of supplying ecosystem services. Such information can improve the design of programs devised to protect and enhance ecosystem services.

  9. Soil erosion after forest fires in the Valencia region

    NASA Astrophysics Data System (ADS)

    González-Pelayo, Óscar; Keizer, Jan Jacob; Cerdà, Artemi

    2014-05-01

    et al., 2007; González-Pelayo et al., 2010b). The knowledge achieved on post-fire erosion must very valuable for new insights and new strategies for landscape management. This research will review the State-of-the-Art of the contribution of the research on soil erosion as a consequence of forest fires in the Valencia Region. The review will show the contribution of the pioneers in the 80's when the USLE and mapping was the main too, the use of plots under simulated and natural rainfall, and also the strategies to control the soil erosion. Acknowledgements The research projects GL2008-02879/BTE, LEDDRA 243857 and RECARE FP7 project 603498 supported this research. References Abad, N., Bautista, S., Blade, C., Caturla, R.N. 2000. Seeding and mulching as erosion control techniques after wildfires in the Valencia region. En P. Balabanis, D. Peter, A. Ghazi y M. Tsogas (Eds.), Mediterranean Desertification Research Results and Policy Implications. Directorate-General Research, vol. 2. European Commission, Brussels, 419-429. Andreu, V., Imeson, A.C., Rubio, J.L. 2001. Temporal changes in soil aggregates and water erosion after a wildfire in a Mediterranean pine forest. Catena. 44, 69-84. Arcenegui, V., Mataix-Solera, J., Guerrero, C., Zornoza, R., Mataix-Beneyto, J., García-Orenes, F., 2008. Immediate effects of wildfires on water repellency and aggregate stability in Mediterranean calcareous soils. Catena 74, 219-226. Bautista, S., Bellot, J., Vallejo, R. 1996. Mulching treatment for postfire soil conservation in a semiarid ecosystem. Arid Soil Research and Rehabilitation 10, 235-242. Bodí, M., Mataix-Solera, J., Stefan H. Doerr, S.H., Cerdà, A. 2012. The wettability of ash from burned vegetation and its relationship to Mediterranean plant species type, burn severity and total organic carbon content. Geoderma 160, 599-607. Boix-Fayos, C. 1997. The roles of texture and structure in the water retention capacity of burnt Mediterranean soils with varying rainfall. Catena

  10. Tuberculosis infection control in health facilities in Lithuania: lessons learnt from a capacity support project.

    PubMed

    Turusbekova, N; Ljungqvist, I; Davidavičiene, E; Mikaityte, J; van der Werf, M J

    2016-03-21

    Tuberculosis (TB) infection control (IC) is key in controlling TB transmission in health facilities in Lithuania. This article presents a project that aimed at supporting health care facilities in Lithuania in implementing TB-IC. The project consisted of 1) facility TB-IC assessments, 2) development of facility TB-IC plans, 3) TB-IC training and 4) site visits. We assessed the impact of these activities through a self-assessment questionnaire. The project resulted in limited improvements. Most progress was seen in administrative and managerial activities. Possible reasons for the limited improvements are challenges with funding and the lack of supportive legislation and a national TB-IC plan.

  11. Reduction of Gun Erosion and Correlation of Gun Erosion Measurements

    NASA Technical Reports Server (NTRS)

    Bogdanoff, Dave; Wercinski, Paul (Technical Monitor)

    1997-01-01

    Gun barrel erosion is serious problem with two-stage light gas guns. Excessive barrel erosion can lead to poor or failed launches and frequent barrel changes, with the corresponding down time. Also, excessive barrel erosion can limit the maximum velocity obtainable by loading down the hydrogen working gas with eroded barrel material. Guided by a CFD code, the operating conditions of the Ames 0.5-inch gun were modified to reduce barrel erosion. The changes implemented included: (1) reduction in the piston mass, powder mass and hydrogen fill pressure; and (2) reduction in pump tube volume, while maintaining hydrogen mass. The latter change was found, in particular, to greatly reduce barrel erosion. For muzzle velocity ranges of 6.1 - 6.9 km/sec, the barrel erosion was reduced by a factor of 10. Even for the higher muzzle velocity range of 7.0 - 8.2 km/sec, the barrel erosion was reduced by a factor of 4. Gun erosion data from the Ames 0.5-inch, 1.0-inch, and 1.5-inch guns operated over a wide variety of launch conditions was examined and it was found that this data could be correlated using four different parameters: normalized powder charge energy, normalized hydrogen energy density, normalized pump tube volume and barrel diameter. The development of the correlation and the steps used to collapse the experimental data are presented. Over a certain parameter range in the correlation developed, the barrel erosion per shot is found to increase very rapidly. The correlation should prove useful in the selection of gun operating conditions and the design of new guns. Representative shapes of eroded gun barrels are also presented.

  12. Coastal Change Along the Shore of Northeastern South Carolina: The South Carolina Coastal Erosion Study

    USGS Publications Warehouse

    Barnhardt, W. A.

    2009-01-01

    The U.S. Geological Survey, in cooperation with the South Carolina Sea Grant Consortium, conducted a 7-year, multi-disciplinary study of coastal erosion in northeastern South Carolina. The main objective was to understand the geologic and oceanographic processes that control sediment movement along the region's shoreline and thereby improve projections of coastal change. The study used high-resolution remote sensing and sampling techniques to define the geologic framework and assess historic shoreline change. Based on these findings, oceanographic-process studies and numerical modeling were carried out to determine the rates and directions of sediment transport along South Carolina's Grand Strand.

  13. Project Orion, Environmental Control and Life Support System Integrated Studies

    NASA Technical Reports Server (NTRS)

    Russell, James F.; Lewis, John F.

    2008-01-01

    Orion is the next vehicle for human space travel. Humans will be sustained in space by the Orion subystem, environmental control and life support (ECLS). The ECLS concept at the subsystem level is outlined by function and technology. In the past two years, the interface definition with other subsystems has increased through different integrated studies. The paper presents the key requirements and discusses three recent studies (e.g., unpressurized cargo) along with the respective impacts on the ECLS design moving forward.

  14. Is splash erosion potential species specific? Measuring of splash erosion potential under forest in different succession stages along a biodiversity gradient in the humid subtropics

    NASA Astrophysics Data System (ADS)

    Geißler, C.; Kühn, P.; Scholten, T.

    2009-04-01

    It is widely accepted that (forest) vegetation is a key control for the type and intensity of soil erosion. The current paradigm is that natural or quasi-natural vegetation protects the soil from erosion and that agricultural vegetation or land use generally enhances erosion. The latter was in focus of most research during the last decades and less interest was paid on natural systems, which are more difficult to study. Nevertheless, afforestation is widely used as a measure of soil protection against soil erosion. Rainfall can be highly erosive particularly in the humid subtropics. Regarding climate change, also precipitation regime may change in direction to even more severe storms and higher rainfall intensities; it is a research field of growing importance. Key mechanisms of a vegetation cover in reducing or enhancing erosion are modifications of drop-size distribution, retention of raindrop impact on the soil and changes in amount and spatial distribution of rainfall at the ground surface. Controlling determinants are rainfall intensity, drop size distribution, drop fall velocity, height of the canopy as well as density of the canopy, crown and leaf traits, LAI and coverage by a litter layer. Large drops are supposed to be significant sources of splash detachment in forests (Brandt 1989; Vis 1986). However, the mechanisms of reducing (or enhancing?) splash detachment under forest in relation to species richness and species composition are not well understood. Some studies indicate that raindrop impact is species specific (Calder 2001; Nanko et al. 2006) and some neglect the effects of species specific impacts (Foot & Morgan 2005). Our research uses different methods of rainfall characterization (splash cups, tipping-bucket rain gauge, laser distrometer) to reveal the described mechanisms from the canopy through different vegetation layers to the ground. First results of splash cup measurements (revised after Ellison 1947) show that sand loss under vegetation

  15. Does vegetation prevent wave erosion of salt marsh edges?

    PubMed

    Feagin, R A; Lozada-Bernard, S M; Ravens, T M; Möller, I; Yeager, K M; Baird, A H

    2009-06-23

    This study challenges the paradigm that salt marsh plants prevent lateral wave-induced erosion along wetland edges by binding soil with live roots and clarifies the role of vegetation in protecting the coast. In both laboratory flume studies and controlled field experiments, we show that common salt marsh plants do not significantly mitigate the total amount of erosion along a wetland edge. We found that the soil type is the primary variable that influences the lateral erosion rate and although plants do not directly reduce wetland edge erosion, they may do so indirectly via modification of soil parameters. We conclude that coastal vegetation is best-suited to modify and control sedimentary dynamics in response to gradual phenomena like sea-level rise or tidal forces, but is less well-suited to resist punctuated disturbances at the seaward margin of salt marshes, specifically breaking waves.

  16. Does vegetation prevent wave erosion of salt marsh edges?

    PubMed Central

    Feagin, R. A.; Lozada-Bernard, S. M.; Ravens, T. M.; Möller, I.; Yeager, K. M.; Baird, A. H.

    2009-01-01

    This study challenges the paradigm that salt marsh plants prevent lateral wave-induced erosion along wetland edges by binding soil with live roots and clarifies the role of vegetation in protecting the coast. In both laboratory flume studies and controlled field experiments, we show that common salt marsh plants do not significantly mitigate the total amount of erosion along a wetland edge. We found that the soil type is the primary variable that influences the lateral erosion rate and although plants do not directly reduce wetland edge erosion, they may do so indirectly via modification of soil parameters. We conclude that coastal vegetation is best-suited to modify and control sedimentary dynamics in response to gradual phenomena like sea-level rise or tidal forces, but is less well-suited to resist punctuated disturbances at the seaward margin of salt marshes, specifically breaking waves. PMID:19509340

  17. Coastal Erosion along Monterey Bay.

    DTIC Science & Technology

    1985-03-01

    RD-Al155 61@ COASTAL EROSION ALONG MONTEREY BAY(U) NAVAL1/ A8POSTGRADUATE SCHOOL MONTEREY CA A I SKLAVIDIS El AL. UNCLASSIFIED F/G 8/3 NmIIhllllllll...RESOLUTION TEST CHART NAVAL POSTGRADUATE SCHOOL Monterey, California 0 to Lfl IC)I I ~JUN 2 71985 THESIS~ COASTAL EROSION ALONG MONTEREY BAY by Anastasios I...PERIOD COVERED Master’s thesis; COASTAL EROSION ALONG MONTEREY BAY March 1985 4. PERFORMING ORG. REPORT NUMBIER 7. AUTMOR(s) 6. CONTRACT OR GRANT NUMBER(a

  18. High Voltage TAL Erosion Characterization

    NASA Technical Reports Server (NTRS)

    Jacobson, David T.

    2003-01-01

    Extended operation of a D-80 anode layer thruster at high voltage was investigated. The thruster was operated for 1200 hours at 700 Volts and 4 Amperes. Laser profilometry was employed to quantify the erosion of the thruster's graphite guard rings and electrodes at 0, 300, 600, 900, and 1200 hours. Thruster performance and electrical characteristics were monitored over the duration of the investigation. The guard rings exhibited asymmetric erosion that was greatest in the region of the cathode. Erosion of the guard rings exposed the magnet poles between 600 to 900 hours of operation.

  19. Cavitation erosion size scale effects

    NASA Technical Reports Server (NTRS)

    Rao, P. V.; Buckley, D. H.

    1984-01-01

    Size scaling in cavitation erosion is a major problem confronting the design engineers of modern high speed machinery. An overview and erosion data analysis presented in this paper indicate that the size scale exponent n in the erosion rate relationship as a function of the size or diameter can vary from 1.7 to 4.9 depending on the type of device used. There is, however, a general agreement as to the values of n if the correlations are made with constant cavitation number.

  20. National Ignition Facility Project Completion and Control System Status

    SciTech Connect

    Van Arsdall, P J; Azevedo, S G; Beeler, R G; Bryant, R M; Carey, R W; Demaret, R D; Fisher, J M; Frazier, T M; Lagin, L J; Ludwigsen, A P; Marshall, C D; Mathisen, D G; Reed, R K

    2009-10-02

    The National Ignition Facility (NIF) is the world's largest and most energetic laser experimental system providing a scientific center to study inertial confinement fusion (ICF) and matter at extreme energy densities and pressures. Completed in 2009, NIF is a stadium-sized facility containing a 1.8-MJ, 500-TW 192-beam ultraviolet laser and target chamber. A cryogenic tritium target system and suite of optical, X-ray and nuclear diagnostics will support experiments in a strategy to achieve fusion ignition starting in 2010. Automatic control of NIF is performed by the large-scale Integrated Computer Control System (ICCS), which is implemented by 2 MSLOC of Java and Ada running on 1300 front-end processors and servers. The ICCS framework uses CORBA distribution for interoperation between heterogeneous languages and computers. Laser setup is guided by a physics model and shots are coordinated by data-driven distributed workflow engines. The NIF information system includes operational tools and a peta-scale repository for provisioning experimental results. This paper discusses results achieved and the effort now underway to conduct full-scale operations and prepare for ignition.

  1. General Design Memorandum. Phase I and Environmental Impact Statement for Flood Control and Related Purposes, Sheyenne River, North Dakota.

    DTIC Science & Technology

    1982-01-01

    not increase down- stream flood problems and that existing drainage projects be reassessed to determine if additional controls are needed. The North...More Land Treatment Use of more land treatment measures throughout the basin could provide water quality and erosion control benefits. Encouragement of...National Grasslands is managed under the multiple-use concept with emphasis on grazing and erosion control . In the future, increased emphasis will be

  2. The erosion of citizenship.

    PubMed

    Turner, B S

    2001-06-01

    The Marshallian paradigm of social citizenship has been eroded because the social and economic conditions that supported postwar British welfare consensus have been transformed by economic and technological change. This article argues that effective entitlement was based on participation in work, war and reproduction, resulting in three types of social identity: worker-citizens, warrior-citizens and parent-citizens. The casualization of labour and the technological development of war have eroded work and war as routes to active citizenship. Social participation through reproduction remains important, despite massive changes to marriage and family as institutions. In fact the growth of new reproductive technologies have reinforced the normative dominance of marriage as a social relation. These rights of reproduction are described as 'reproductive citizenship'. The article also considers the role of voluntary associations in Third-Way strategies as sources of social cohesion in societies where social capital is in decline, and argues that the voluntary sector is increasingly driven by an economic logic of accumulation. With the erosion of national citizenship, Marshall's three forms of rights (legal, political and social) have been augmented by rights that are global, namely environmental, aboriginal and cultural rights. These are driven by global concerns about the relationship between environment, community and body such that the quest for social security has been replaced by concerns for ontological security.

  3. Tropical volcanic islands: best first cycle erosion laboratories.

    NASA Astrophysics Data System (ADS)

    Rad, S.; Rive, K.; Gaillardet, J.; Allegre, C. J.

    2007-12-01

    Lesser Antilles islands are located in a tropical climate with high temperatures (24 to 28 ° C), high precipitation (can reach 12 m/yr), very dense vegetation, sharp relief with a NS gradient of age. Antilles rivers have a torrential hydrologic regime with extreme erosion conditions. Chemical weathering rates are among highest world values 140-200 t/km2/yr on surface and 2 to 5 time higher when subsurface water circulations are taken account (Rad et al., 2007). Timescales and physical rates of erosion are calculated from U-Th isotopic compositions. Our results, with 3 different methods (all based on mass budgets between the river bedrock and its erosion products) show a good agreement for physical erosion rates with a maximum value of 2500 t/km2/yr. We show that solid loads of these volcanic rivers are dominated by sand, which represent more than 80% of the soil profile. Erosion rates are directly correlated to the age of basins. Indeed, among all parameters (climat, runoff, slopes, vegetation...) the age basins is a key control parameter. The younger the basin is the higher the weathering rate is. This correlation asserts that younger volcanic rocks are more easily weathered than old ones: young fresh material is easily mobilized by erosion, while for older rocks with thick soil covers, chemical and physical erosion rates are much lower, they reach a threshold with low chemical and physical rates once soils are constituted. It seems that rivers draining young lava flows are also the ones, which are not at steady state with the lowest mechanical denudation rates. Erosion processes in Lesser Antilles are typical of a first cycle erosion with simple relationship between rates, timescale of erosion and basins ages. It appears that first stage of erosion are characterized by high chemical denudation rates and low physical denudation rates, the erosion products are then close to the bedrock. It is then followed in a second stage by constant chemical weathering rates

  4. 75 FR 28626 - Disease, Disability, and Injury Prevention and Control Special Interest Projects (SIPs): SIP 10...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Disease, Disability, and Injury Prevention and Control Special Interest Projects (SIPs): SIP 10-029, Pilot Study--Cancer Survivorship Care Planning & SIP 10-030, Evaluating Special Events as...

  5. Evaluation of the USDA Northeast Area-wide Tick Control Project by Meta-analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As part of the Northeast Area-wide Tick Control Project (NEATCP), meta-analyses were performed using pooled data on the extent of tick-vector control achieved through seven concurrent studies, conducted within five states, using USDA ‘4-Poster’ devices to deliver targeted-acaricide to white-tailed d...

  6. 9 CFR 54.9 - Waiver of requirements for scrapie control pilot projects.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Waiver of requirements for scrapie... CONTROL OF SCRAPIE Scrapie Indemnification Program § 54.9 Waiver of requirements for scrapie control pilot projects. The Administrator may waive the following requirements of this part for participants in a...

  7. 77 FR 31358 - Disease, Disability, and Injury Prevention and Control Special Interest Projects (SIPs): Initial...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-25

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Disease, Disability, and Injury Prevention and Control Special Interest Projects (SIPs): Initial Review The meeting announced below concerns Research...

  8. Multi-Canister overpack pressurization monitoring and control methodology for the spent nuclear fuel project

    SciTech Connect

    Pajunen, A.L., Westinghouse Hanford

    1996-07-19

    A control methodology is developed and monitoring alternatives evaluated for controlling pressurization in a Multi- Canister Overpack for the Hanford Spent Nuclear Fuel Project. Monitoring alternative evaluations include concept description, identification of uncertainties, and identification of experimental work required for implementation. A monitoring alternative is recommended and implementation requirements, risks and start up testing associated with the recommendation are discussed.

  9. Chaos control and function projective synchronization of fractional-order systems through the backstepping method

    NASA Astrophysics Data System (ADS)

    Das, S.; Yadav, V. K.

    2016-10-01

    We study the chaos control and the function projective synchronization of a fractional-order T-system and Lorenz chaotic system using the backstepping method. Based on stability theory, we consider the condition for the local stability of nonlinear three-dimensional commensurate fractional-order system. Using the feedback control method, we control the chaos in the considered fractional-order T-system. We simulate the function projective synchronization between the fractional-order T-system and Lorenz system numerically using MATLAB and depict the results with plots.

  10. Climate change impacts on soil erosion in the Great Lakes Region

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantifying changes in potential soil erosion under projections of changing climate is important for the sustainable management of land resources, especially for regions dominated by agricultural land use, as soil loss estimates will be helpful in identifying areas susceptible to erosion, targeting ...

  11. Uncertainty of climate change impacts on soil erosion from cropland in central Oklahoma

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Impacts of climate change on soil erosion and the potential need for additional conservation actions are typically estimated by applying a hydrologic and soil erosion model under present and future climate conditions defined by an emission scenario. Projecting future climate conditions harbors sever...

  12. Impact of Precipitation Changes on Runoff and Soil Erosion in Korea using CLIGEN and WEPP

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The quality of spatially and temporally distributed weather information is critical in soil erosion model results because of the primary influence of rainfall on runoff and soil movement. Detailed climate data for the Water Erosion Prediction Project (WEPP) model can be generated by a climate genera...

  13. Does WEPP meet the specificity of soil erosion in steep mountain regions?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We chose the USDA-ARS-WEPP model (Water Erosion Prediction Project) to describe the soil erosion in the Urseren valley (Central Switzerland) as it seems to be one of the most promising models for steep mountain environments. Crucial model parameters were determined in the field (slope, plant species...

  14. Potential change in soil erosion trend and risk during 2010-2039 in central Oklahoma, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potential for global climate changes to increase risk of soil erosion is clear, but quantitative analysis of this risk is limited due to high spatial and temporal variability in projected climate change scenarios. For accurate prediction of soil erosion risk under climate change, climate chang...

  15. Model development and applications at the USDA-ARS National Soil Erosion Research Laboratory

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The United States Department of Agriculture (USDA) has a long history of development of soil erosion prediction technology, initially with empirical equations like the Universal Soil Loss Equation (USLE), and more recently with process-based models such as the Water Erosion Prediction Project (WEPP)...

  16. Shrublands and Soil Erosion. An State-of-the-Art

    NASA Astrophysics Data System (ADS)

    García Estríngana, Pablo; Dunkerley, David; Cerdà, Artemi

    2014-05-01

    Shrublands and Soil Erosion. An State-of-the-Art Arid and semiarid regions occupy two-fifth of the continents (Reynolds et al., 2007). These regions are characterized by dry climatic conditions, recurrent droughts and a scant rainfall pattern with a marked seasonality and a high inter-annual variability which makes water to be a scant resource and vegetation to follow a high variability spatial distribution pattern (Breshears et al., 1998; Cecchi et al., 2006; Dunkerley, 2008). These conditions make these areas more sensitive to climate change (Rowell, 2005) and to land use change as a consequence of land abandonment (Poyatos et al., 2003; Delgado et al., 2010; García-Ruiz, 2010), increasing the risk of desertification (Puigdefábregas and Mendizabal, 1998; Geeson et al., 2002), in such a way that 65-70% of arid and semiarid areas are vulnerable to this degradation process (UNEP, 1991). Soil Erosion and Land Degradation are closely related to the changes in the vegetation cover (Zhao et al., 2013). Although other factors such as rainfall intensity or slope (Ziadat and Taimeh, 2013) the plant cover is the main factor that controls the soil erosion, controlling the infiltration and runoff generation (Cerdà, 1998a; Kargar Chigani et al., 2012; Haregeweyn, 2013). Soil erosion show non-sustainable rates under these regions, such as under Mediterranean conditions (Cerdà et al., 2010) and on agriculture land (Cerdà et al; 2007; 2009) due to climatic conditions, to parent material and to the roughed terrain (Romero Díaz et al., 2010). The traditional impact of grazing, of extremely intense fires, of ploughing and the widespread use of herbicides on agriculture, the increase of the road and railway embankments and the agricultural land abandonment cause vegetation removal. Canopy cover partitions rainfall reducing the amount of water reaching the soil and the kinetic energy of rainfall drops, protecting the soil against the impact of rainfall drops. Vegetation

  17. Transition from control to elimination: impact of the 10-year global fund project on malaria control and elimination in China.

    PubMed

    Wang, Ru-Bo; Zhang, Qing-Feng; Zheng, Bin; Xia, Zhi-Gui; Zhou, Shui-Sen; Tang, Lin-Hua; Gao, Qi; Wang, Li-Ying; Wang, Rong-Rong

    2014-01-01

    The Global Fund to Fight AIDS, Tuberculosis and Malaria (GFATM) supported a project on the control and elimination of malaria in People's Republic of China which was one of the biggest-scale international cooperation programmes to control malaria in the country during the past 10 years. The project promoted the effective implementation of the Chinese national malaria control programme. On the basis of epidemiologic data, an overview of the project activities and key performance indicators, the overall impact of the GFATM project was evaluated. We also reviewed relevant programme features including technological and management approaches, with a focus on best practice, innovations in implementation and the introduction of international standards. Last, we summarised the multi-stakeholder cooperation mechanism and comments on its sustainability in the post-GFATM period. Recommendations for the future management of the Chinese national malaria elimination programme are put forward after considering the challenges, shortcomings and lessons learnt during the implementation of the GFATM project in China to sustain past achievements and foster the attainment of the ultimate goal of malaria elimination for the country.

  18. The Erosive Potential of Some Flavoured Waters

    PubMed Central

    Rees, Jeremy; Loyn, Theresa; Hunter, Lindsay; Sadaghiani, Leili; Gilmour, Alan

    2007-01-01

    Objectives To assess the erosive potential of a number of readily available flavoured waters in the laboratory. Methods The erosive potential was assessed by measuring the pH, neutralisable acidity and ability to erode enamel. These were compared to an orange juice positive control. Results The pH of the flavoured waters ranged from 2.64–3.24 with their neutralisable acidity ranging from 4.16–16.30 mls of 0.1M NaOH. The amount of enamel removed following 1-hour immersion in the drinks ranged from 1.18–6.86 microns. In comparison, the orange juice control had a pH of 3.68, a neutralisable acidity of 19.68 mls of 0.1 M NaOH and removed 3.24 microns of enamel. Conclusions Many of the flavoured waters tested were found to be as erosive as orange juice. This information will be of use to clinicians when counselling patients with tooth surface loss. (Eur J Dent 2007;1:5–9) PMID:19212489

  19. A Manual of Mosquito Control Projects and Committee Assignments for 4-H and Scouts Biology Class Projects, Organized Community Service Programs, and Individuals Interested in Environmental Management.

    ERIC Educational Resources Information Center

    Hart, Richard A.

    The mosquito control projects presented in this manual were prepared from an educational viewpoint and are intended for use by students in 4-H and Scouts and as a supplement to high school and college biology course work. The major emphasis of the projects is on integrated pest management, an approach utilizing cost-effective control methods which…

  20. Savannah River Site 1991 Road Erosion Inventory.

    SciTech Connect

    Jones, Cliff.

    2007-06-22

    Final Report. USDA Forest Service, Savannah River, Aiken, SC. 28 pp. Abstract - This paper explains the rationale and results of a 1991 road erosion inventory conducted by members of the USDA Forest Service – Savannah River (FS-SR) and USDA Natural Resources Conservation Service (NRCS). The inventory provided information for the Department of Energy - Savannah River (DOE-SR) to justify the need for developing an erosion and sediment control program with appropriate funding, personnel, and equipment. Federally managed since the early 1950’s, the SRS is located on 198,344 acres (80,301 hectares) in the South Carolina counties of Aiken, Barnwell, and Allendale. Located along the eastern border of the Savannah River, the SRS is located within the Upper and Lower Coastal Plains of South Carolina.

  1. Materials erosion and redeposition studies at the PISCES-facility: net erosion under redeposition

    SciTech Connect

    Hirooka, Y.; Goebel, D.M.; Conn, R.W.; Leung, W.K.; Campbell, G.A.

    1986-05-01

    Simultaneous erosion and redeposition of copper and 304 stainless steel under controlled and continuous plasma (D,He,Ar) bombardment has been investigated in the PISCES-facility, which generates typical edge-plasma conditions of magnetic fusion devices. The plasma bombardment conditions are: incident ion flux in the range from 10/sup 17/ to 10/sup 18/ ions/sec/cm/sup 2/, ion bombarding energy of 100 eV, electron temperature in the range from 5 to 15 eV, plasma density in the range from 10/sup 11/ to 10/sup 13/ cm/sup -3/, target temperature in the range from 300 to 900K, and the total ion fluence in the range from 10/sup 20/ to 10/sup 22/ ions/cm/sup 2/. The net erosion yield under redeposition is found to be significantly smaller than the classical sputtering yield data. A first-order modeling is attempted to interpret the erosion and redeposition behavior of materials under plasma bombardment. It is pointed out both theoretically and experimentally that the mean free path for electron impact ionization of the sputtered material is the key parameter to control the overall mechanism of erosion and redeposition. Strongly modified surface morphologies of bombarded targets are observed and indicate a retrapping effect.

  2. Flood control projects in Bangladesh: reasons for failure and recommendations for improvement.

    PubMed

    Hoque, M M; Siddique, M A

    1995-09-01

    Flood control and drainage projects in Bangladesh are intended to give protection from main river floods, flash floods in the east and northeast of the country, and saline intrusion in the lower delta and to improve drainage in order to avoid crop damage. While in some cases such projects have had positive results, in many others their benefits have fallen well below expectations. One of the major reasons for the poor performance of projects is embankment failure, brought about by poor planning, design, construction, operation and maintenance. Recommended measures to improve the efficiency of projects include the involvement of local people in the planning and operation of projects, better training of management staff and the allocation of adequate funds for maintenance.

  3. Runoff mapping using WEPP erosion model and GIS tools

    NASA Astrophysics Data System (ADS)

    de Jong van Lier, Quirijn; Sparovek, Gerd; Flanagan, Dennis C.; Bloem, Elke M.; Schnug, Ewald

    2005-12-01

    Soil erosion, associated with environmental impacts and crop productivity loss, is usually considered the most impacting of surface hydrology processes. Runoff plays a major role in the erosion process, but it is also important by itself as it directly influences several surface hydrologic processes. In this paper, a computer interface (Erosion Database Interface, EDI) is described that allows processing the surface hydrology output database of the Water Erosion Prediction Project (WEPP) erosion prediction model, resulting in a georeferenced estimation of runoff. WEPP output contains non-georeferenced daily information about estimated runoff at the lower end of each Overland Flow Element. EDI, when running with WEPP, allows extracting WEPP-calculated runoff values, transforming them into annual means and relocating them in a georeferenced database readable by Geographic Information Systems (GIS). EDI was applied to a 1990 ha watershed in southeast Brazil, with vegetation of mainly sugarcane, forest, and pasture. A 100-year climate simulation was used as input to WEPP, and erosion values were calculated at about six points per hectare and interpolated to a raster format. EDI was successful in preparing the database for automatic calculation of erosion and hydrologic parameters with WEPP and to restore georeferences to mean annual accumulated runoff data that were imported in the GIS as a vector database. Of all the resulting maps, the runoff map is the one that integrates all of the input parameters required for WEPP simulation, thus reflecting not only the physical environment but also crop growth and management and tillage operations. A very small correlation between runoff and erosion shows them to behave independently. Moreover, it is concluded that on analyzing runoff related to agricultural management, georeferenced runoff studies are especially important. In this context, EDI may be a useful tool to assess the effect of tillage and crop management on runoff

  4. Erosion-resistant composite material

    DOEpatents

    Finch, C.B.; Tennery, V.J.; Curlee, R.M.

    A highly erosion-resistant composite material is formed of chemical vapor-deposited titanium diboride on a sintered titanium diboride-nickel substrate. This material may be suitable for use in cutting tools, coal liquefaction systems, etc.

  5. Mechanics of interrill erosion with wind-driven rain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The vector physics of wind-driven rain (WDR) differs from that of wind-free rain, and the interrill soil detachment equations in the Water Erosion Prediction Project (WEPP) model were not originally developed to deal with this phenomenon. This article provides an evaluation of the performance of the...

  6. Mechanics of Interrill Erosion with Wind-Driven Rain (WDR)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This article provides an evaluation analysis for the performance of the interrill component of the Water Erosion Prediction Project (WEPP) model for Wind-Driven Rain (WDR) events. The interrill delivery rates (Di) were collected in the wind tunnel rainfall simulator facility of the International Cen...

  7. Remote Imaging Applied to Schistosomiasis Control: The Anning River Project

    NASA Technical Reports Server (NTRS)

    Seto, Edmund Y. W.; Maszle, Don R.; Spear, Robert C.; Gong, Peng

    1997-01-01

    The use of satellite imaging to remotely detect areas of high risk for transmission of infectious disease is an appealing prospect for large-scale monitoring of these diseases. The detection of large-scale environmental determinants of disease risk, often called landscape epidemiology, has been motivated by several authors (Pavlovsky 1966; Meade et al. 1988). The basic notion is that large-scale factors such as population density, air temperature, hydrological conditions, soil type, and vegetation can determine in a coarse fashion the local conditions contributing to disease vector abundance and human contact with disease agents. These large-scale factors can often be remotely detected by sensors or cameras mounted on satellite or aircraft platforms and can thus be used in a predictive model to mark high risk areas of transmission and to target control or monitoring efforts. A review of satellite technologies for this purpose was recently presented by Washino and Wood (1994) and Hay (1997) and Hay et al. (1997).

  8. Control room crew operations research project. Final report

    SciTech Connect

    Parry, G.W.; Mosleh, A.

    1995-12-01

    This report presents an assessment of the current state of the art in human reliability analysis (HRA) and highlights the principal shortcomings of current approaches. Issues that should be addressed in an improved HRA approach as well as the constraints imposed by current methodologies used to perform Probabilistic Safety Assessment (PSAs) are identified. A generalized conceptual model for estimating the probabilities of the human failure events that are included in a PSA logic model is presented. The model is expressed as a sum over error modes and error causes. The report emphasizes the importance of understanding the causality of error and suggests one approach to the representation of error causes. An example approach to the qualitative screening of errors of commission is presented. The second part of the report describes an alternative approach to modeling accident scenarios that explicitly considers the dynamic interactions of the various elements and provides the needed environment for implementation of advanced human reliability models. This approach has been incorporated into the Accident Dynamic Simulator (ADS), a computer tool that removes the main roadblock to implementation of this methodology by handling the computational complexities of an integrated model of a large system, its physical processes, and the human behavior of the control room operators. ADS runs on a personal computer and is designed to facilitate the PSA of nuclear power plants. The application of the code to a SGTR initiating event at a Westinghouse PWR is presented.

  9. Control of the formation of projective synchronisation in lower-dimensional discrete-time systems

    NASA Astrophysics Data System (ADS)

    Chee, Chin Yi; Xu, Daolin

    2003-11-01

    Projective synchronisation was recently observed in partially linear discrete-time systems. The scaling factor that characterises the behaviour of projective synchronisation is however unpredictable. In order to manipulate the ultimate state of the synchronisation, a control algorithm based on Schur-Chon stability criteria is proposed to direct the scaling factor onto any predestined value. In the numerical experiment, we illustrate the application on two chaotic discrete-time systems.

  10. Maximum Entropy/Optimal Projection Design Synthesis for Decentralized Control of Large Space Structures

    DTIC Science & Technology

    1988-05-01

    evolve efficient approaches to the solution of the MEOP design equations for optimal , decentralized control. 1.1 Objectives The specific tasks...design. It should also be noted that in a broader context, these results illustrate a new general approach to nonconvex optimization problems. Further...equations. 3 3.2 Extensions to Decentralized Controllers In keeping with the optimal projection philosophy, our approach to decentralized control design

  11. Chevrons formation in laminar erosion

    NASA Astrophysics Data System (ADS)

    Devauchelle, Olivier; Josserand, Christophe; Lagree, Pierre-Yves; Zaleski, Stephane; Nguyen, Khanh-Dang; Malverti, Luce; Lajeunesse, Eric

    2007-11-01

    When eroded by laminar free-surface flows, granular substrates may generate a rich variety of natural patterns. Among them are dunes, similar to the ones observed by Charru and Hinch in a Couette cell (Charru F, Hinch EJ ; Ripple formation on a particle bed sheared by a viscous liquid. Part 1. Steady flow ; JOURNAL OF FLUID MECHANICS 550: 111-121 MAR 10 2006). Chevron-shaped instabilities as those found on the sea-shore, can also be observed, sometimes in competition against dunes formation. These were first pointed out by Daerr et al. when pulling a plate covered with granular material out of a bath of water (Daerr A, Lee P, Lanuza J, et al. ; Erosion patterns in a sediment layer ; PHYSICAL REVIEW E 67 (6): Art. No. 065201 Part 2 JUN 2003). Both instabilities can grow in laminar open-channel flows, an experimental set-up which is more easily controlled. The mechanisms leading to the formation of these patterns are investigated and compared. Whereas dunes formation requires vertical inertia effects, we show that chevrons may result from the non-linear evolution of bars instability, which may grow even in purely viscous flows.

  12. Fractal Tectonics and Erosion

    NASA Astrophysics Data System (ADS)

    Turcotte, Donald L.

    Tectonic processes build landforms that are subsequently destroyed by erosional processes. Landforms exhibit fractal statistics in a variety of ways; examples include (1) lengths of coast lines; (2) number-size statistics of lakes and islands; (3) spectral behavior of topography and bathymetry both globally and locally; and (4) branching statistics of drainage networks. Erosional processes are dominant in the development of many landforms on this planet, but similar fractal statistics are also applicable to the surface of Venus where minimal erosion has occurred. A number of dynamical systems models for landforms have been proposed, including (1) cellular automata; (2) diffusion limited aggregation; (3) self-avoiding percolation; and (4) advective-diffusion equations. The fractal statistics and validity of these models will be discussed. Earthquakes also exhibit fractal statistics. The frequency-magnitude statistics of earthquakes satisfy the fractal Gutenberg-Richter relation both globally and locally. Earthquakes are believed to be a classic example of self-organized criticality. One model for earthquakes utilizes interacting slider-blocks. These slider block models have been shown to behave chaotically and to exhibit self-organized criticality. The applicability of these models will be discussed and alternative approaches will be presented. Fragmentation has been demonstrated to produce fractal statistics in many cases. Comminution is one model for fragmentation that yields fractal statistics. It has been proposed that comminution is also responsible for much of the deformation in the earth's crust. The brittle disruption of the crust and the resulting earthquakes present an integrated problem with many fractal aspects.

  13. Joint Power and Multiple Access Control for Wireless Mesh Network with Rose Projection Method

    PubMed Central

    Tang, Meiqin; Shang, Lili; Xin, Yalin; Liu, Xiaohua; Wei, Xinjiang

    2014-01-01

    This paper investigates the utility maximization problem for the downlink of the multi-interface multichannel wireless mesh network with orthogonal frequency division multiple access. A cross-layer joint power and multiple access control algorithm are proposed. Rosen projection matrix is combined with Solodov projection techniques to build a three-memory gradient Rosen projection method, which is applied to solve this optimization problem. The convergence analysis is given and simulations show that the proposed solution achieves significant throughput compared with existing approaches. PMID:24883384

  14. Joint power and multiple access control for wireless mesh network with Rose projection method.

    PubMed

    Tang, Meiqin; Shang, Lili; Xin, Yalin; Liu, Xiaohua; Wei, Xinjiang

    2014-01-01

    This paper investigates the utility maximization problem for the downlink of the multi-interface multichannel wireless mesh network with orthogonal frequency division multiple access. A cross-layer joint power and multiple access control algorithm are proposed. Rosen projection matrix is combined with Solodov projection techniques to build a three-memory gradient Rosen projection method, which is applied to solve this optimization problem. The convergence analysis is given and simulations show that the proposed solution achieves significant throughput compared with existing approaches.

  15. Erosion by an Alpine glacier

    NASA Astrophysics Data System (ADS)

    Herman, Frédéric; Beyssac, Olivier; Lane, Stuart; Brughelli, Mattia; Leprince, Sebastien; Brun, Fanny

    2015-04-01

    Most mountain ranges on Earth owe their morphology to the action of glaciers and icecaps over the last few million years. Our current understanding of how glaciers have modified mountainous landforms has mainly been driven through landscape evolution models. These have included an array of erosion laws and mainly progressed through the implementation of various levels of sophistication regarding ice dynamics, subglacial hydrology or thermodynamics of water flow. However, the complex nature of the erosion processes involved and the difficulty of directly examining the ice-bedrock interface of contemporary glaciers has precluded the establishment of a prevailing erosion theory. Here we quantify the spatial variations in ice sliding velocity and erosion rate of a fast-flowing Alpine glacier in New Zealand during a 5-month period. By combining high resolution 3D measurements of surface velocity from optical satellite imagery with the quantification of both the production and provenance of sediments by the glacier, we show that erosion rates are proportional to sliding velocity raised to a power of about two. This result is consistent with abrasion theory. Given that the ice sliding velocity is a nonlinear function of ice thickness and ice surface slope, the response of glacial erosion to precipitation changes is highly nonlinear. Finally, our ability to constrain the glacial abrasion law present opportunities to further examine the interaction between glaciation and mountain evolution.

  16. Lessons Learned and Flight Results from the F15 Intelligent Flight Control System Project

    NASA Technical Reports Server (NTRS)

    Bosworth, John

    2006-01-01

    A viewgraph presentation on the lessons learned and flight results from the F15 Intelligent Flight Control System (IFCS) project is shown. The topics include: 1) F-15 IFCS Project Goals; 2) Motivation; 3) IFCS Approach; 4) NASA F-15 #837 Aircraft Description; 5) Flight Envelope; 6) Limited Authority System; 7) NN Floating Limiter; 8) Flight Experiment; 9) Adaptation Goals; 10) Handling Qualities Performance Metric; 11) Project Phases; 12) Indirect Adaptive Control Architecture; 13) Indirect Adaptive Experience and Lessons Learned; 14) Gen II Direct Adaptive Control Architecture; 15) Current Status; 16) Effect of Canard Multiplier; 17) Simulated Canard Failure Stab Open Loop; 18) Canard Multiplier Effect Closed Loop Freq. Resp.; 19) Simulated Canard Failure Stab Open Loop with Adaptation; 20) Canard Multiplier Effect Closed Loop with Adaptation; 21) Gen 2 NN Wts from Simulation; 22) Direct Adaptive Experience and Lessons Learned; and 23) Conclusions

  17. Overview of implementing a project control system in the nuclear utility industry

    SciTech Connect

    Cooprider, D.H. )

    1994-03-01

    During the late 1980s, a metamorphosis began at Florida Power and Light Company (FPL). A strategic step in nuclear engineering's efforts to become more cost effective began in January 1990. A project control department was formed. The initial mission was to provide support for nuclear engineering design activities associated with FPL's two twin-unit nuclear power generation facilities - Turkey Point and St. Lucie. Later, the goal expanded to include the division's materials management, nuclear licensing, and information management departments. The project control group was organized along the lines of the organizations served. Separate dedicated groups were established for each plant. Since most engineering activity was based at the Juno Beach headquarters, the project control staff also was based there.

  18. Projective synchronization of nonidentical fractional-order neural networks based on sliding mode controller.

    PubMed

    Ding, Zhixia; Shen, Yi

    2016-04-01

    This paper investigates global projective synchronization of nonidentical fractional-order neural networks (FNNs) based on sliding mode control technique. We firstly construct a fractional-order integral sliding surface. Then, according to the sliding mode control theory, we design a sliding mode controller to guarantee the occurrence of the sliding motion. Based on fractional Lyapunov direct methods, system trajectories are driven to the proposed sliding surface and remain on it evermore, and some novel criteria are obtained to realize global projective synchronization of nonidentical FNNs. As the special cases, some sufficient conditions are given to ensure projective synchronization of identical FNNs, complete synchronization of nonidentical FNNs and anti-synchronization of nonidentical FNNs. Finally, one numerical example is given to demonstrate the effectiveness of the obtained results.

  19. Inverting the Pendulum Using Fuzzy Control (Center Director's Discretionary Fund (Project 93-02)

    NASA Technical Reports Server (NTRS)

    Kissel, R. R.; Sutherland, W. T.

    1997-01-01

    A single pendulum was simulated in software and then built on a rotary base. A fuzzy controller was used to show its advantages as a nonlinear controller since bringing the pendulum inverted is extremely nonlinear. The controller was implemented in a Motorola 6811 microcontroller. A double pendulum was simulated and fuzzy control was used to hold it in a vertical position. The double pendulum was not built into hardware for lack of time. This project was for training and to show advantages of fuzzy control.

  20. Three Gorges Reservoir Area: soil erosion under natural condition vs. soil erosion under current land use

    NASA Astrophysics Data System (ADS)

    Schönbrodt, Sarah; Behrens, Thorsten; Scholten, Thomas

    2010-05-01

    Xiangjiaba site (mean 640.1 t ha-1 a-1) the maximum soil erosion of 1,115.4 t ha-1 a-1 under natural conditions is negligible lower. Compared to these erosion rates the mean soil loss under current land use is considerably lower (Xiangxi Catchment: mean 161.5 t ha-1 a-1; Backwater area: mean 166.3 t ha-1 a-1; Quyuan: mean 211.2 t ha-1 a-1; Xiangjiaba: mean 158.6 t ha-1 a-1). However, soil loss of maximum 2,662.2 t ha-1 a-1 for Xiangxi Catchment, 2,397.9 t ha-1 a-1 for the backwater area, 1,689.9 t ha-1 a-1 for Quyuan site, and 957.1 t ha-1 a-1 for Xiangjiaba site are also potentially possible. According to the Chinese Soil Erosion Rate Standard (cf. Xu et al., 2008) almost 44 % of the area of the Xiangxi Catchment show extreme (> 80 t ha-1 a-1) soil erosion which mainly occur in the backwater area. Our results show that the Xiangxi Catchment is already highly prone to soil erosion under natural conditions. In places, the current land use in the mountainous relief of the Xiangxi Catchment still increases the potential soil erosion to an extreme high level. However, mean potential soil loss rates under current land use lie under those due to the natural disposition. This is due to the fact that the natural disposition to soil erosion does not consider the complete topography factor (LS factor), that effects the potential soil loss (R² = 0.77) by the human-influenced erosive slope length through farmland terraces. Moreover, our results indicate an urgent need of proper management and conservation decisions in order to reduce soil erosion against the background of a high land use dynamic in a region with low carrying capacity (Beattie, 2002). Literature Beattie, J. (2002): Dam Building, Dissent, And Development: The Emergence Of The Three Gorges Project. New Zealand Journal of Asian Studies, Vol. 4(1): 138-158. Behrens, T., Schmidt, K. and Scholten, T. (2008). An approach to remove uncertainties in nominal environmental covariates and soil class maps. In: Hartemink, A. E., Mc

  1. Soil erosion in developing countries: A politicoeconomic explanation

    NASA Astrophysics Data System (ADS)

    Thapa, Gopal B.; Weber, Karl E.

    1991-07-01

    Soil erosion is accelerating in developing countries of Asia, Africa, and Latin America. It has threatened the livelihood of millions of peasants, for agriculture is their economic mainstay. A probe into the forces causing erosion reveals that the elite’s resolve to accumulate ever more wealth and to maintain, consolidate, or expand their sociopolitical power and the necessity of the poor to fulfill their requirements of food, fuelwood, and fodder are the two major factors accelerating soil erosion. Unless the vast masses of poor people are integrated into the national mainstream through the implementation of equitable and redistributive development policies, it is impossible to control the accelerating rate of soil erosion and thus to achieve the objective of sustainable development.

  2. Solid-particle erosion of aluminum/particulate ceramic composites

    SciTech Connect

    Goretta, K.C.; Wu, W.; Routbort, J.L. ); Rohatgi, P.K. )

    1990-06-01

    Impact erosion of 2014 aluminum, 2014 aluminum + 20 vol % particulate silicon carbide, and 2014 aluminum + 20 vol % particulate aluminum oxide has been studied at room temperature. The alloys were tested in the as-received and heat-treated conditions. Experiments were conducted with aluminum oxide abrasive in vacuum in a slinger-type apparatus over a range of abrasive size, velocity, and angle of impact. Erosion rates were influenced by reinforcement and heat treatment. Reduced ductility, both overall and local, attributed to reinforcement or heat treatment, caused, under most conditions, more rapid erosion of the composites. The data suggest that erosion rate can be minimized by proper microstructural control, involving reducing reinforcement segregation and the amount of intermetallic compounds. 37 refs., 7 figs.

  3. Stimulation Controls and Mitigation of Induced Seismicity for EGS Project: Examples from the Newberry EGS Demonstration Project (Invited)

    NASA Astrophysics Data System (ADS)

    Petty, S.; Cladouhos, T. T.; Osborn, W.; Iovenitti, J.

    2010-12-01

    Creating an EGS reservoir depends upon injection induced seismicity (IIS) to create fracture permeability and allow the reservoir to be mapped using passive microseismic monitoring. However, in some cases, the seismicity induced through the stimulation has been felt by surrounding populations and in one case caused sufficient concern to force shut-down of the project. AltaRock Energy, Inc. is working with universities, national labs and consultants on the Newberry Volcano EGS Demonstration Project (Funded in part through a grant from the US DOE: DE-EE0002777). This project will attempt to stimulate a very low permeability existing deep geothermal well with high temperature to develop a circulating geothermal system that be able to sustain production of economic quantities of hot water and steam for power production. In order to allay concerns that IIS might become hazardous at Newberry, AltaRock Energy has agreed to a robust series of safeguards and mitigation controls. The safeguards detail how the EGS stimulation will be monitored and under what circumstances the stimulation should be safely reduced or halted to avoid perceptible seismic events that would alarm or possibly cause damage to the local community. The International Energy Agency (IEA) Implementing Agreement for a Cooperative Programme on Geothermal Energy Research and Technology, or Geothermal Implementing Agreement (GIA), developed an induced seismicity mitigation protocol which has been adopted by the US Department of Energy for their funded EGS Demonstration Projects. AltaRock is the process of making this protocol site specific for the Newberry project.The Notice of Intent (NOI) to the BLM for the Newberry EGS Demonstration includes plans to conduct an induced seismicity hazards and risk assessment. These plans include implementing the Protocol for Induced Seismicity Associated with Geothermal System (Majer et al., 2008), adopted by the International Energy Agency. The theory of IIS has recently

  4. Spinal sensory projection neuron responses to spinal cord stimulation are mediated by circuits beyond gate control

    PubMed Central

    Zhang, Tianhe C.; Janik, John J.; Peters, Ryan V.; Chen, Gang; Ji, Ru-Rong

    2015-01-01

    Spinal cord stimulation (SCS) is a therapy used to treat intractable pain with a putative mechanism of action based on the Gate Control Theory. We hypothesized that sensory projection neuron responses to SCS would follow a single stereotyped response curve as a function of SCS frequency, as predicted by the Gate Control circuit. We recorded the responses of antidromically identified sensory projection neurons in the lumbar spinal cord during 1- to 150-Hz SCS in both healthy rats and neuropathic rats following chronic constriction injury (CCI). The relationship between SCS frequency and projection neuron activity predicted by the Gate Control circuit accounted for a subset of neuronal responses to SCS but could not account for the full range of observed responses. Heterogeneous responses were classifiable into three additional groups and were reproduced using computational models of spinal microcircuits representing other interactions between nociceptive and nonnociceptive sensory inputs. Intrathecal administration of bicuculline, a GABAA receptor antagonist, increased spontaneous and evoked activity in projection neurons, enhanced excitatory responses to SCS, and reduced inhibitory responses to SCS, suggesting that GABAA neurotransmission plays a broad role in regulating projection neuron activity. These in vivo and computational results challenge the Gate Control Theory as the only mechanism underlying SCS and refine our understanding of the effects of SCS on spinal sensory neurons within the framework of contemporary understanding of dorsal horn circuitry. PMID:25972582

  5. The conceptual framework of the International Tobacco Control (ITC) Policy Evaluation Project.

    PubMed

    Fong, G T; Cummings, K M; Borland, R; Hastings, G; Hyland, A; Giovino, G A; Hammond, D; Thompson, M E

    2006-06-01

    This paper describes the conceptual model that underlies the International Tobacco Control Policy Evaluation Project (ITC Project), whose mission is to measure the psychosocial and behavioural impact of key policies of the Framework Convention on Tobacco Control (FCTC) among adult smokers, and in some countries, among adult non-smokers and among youth. The evaluation framework utilises multiple country controls, a longitudinal design, and a pre-specified, theory-driven conceptual model to test hypotheses about the anticipated effects of specific policies. The ITC Project consists of parallel prospective cohort surveys of representative samples of adult smokers currently in nine countries (inhabited by over 45% of the world's smokers), with other countries being added in the future. Collectively, the ITC Surveys constitute the first-ever international cohort study of tobacco use. The conceptual model of the ITC Project draws on the psychosocial and health communication literature and assumes that tobacco control policies influence tobacco related behaviours through a causal chain of psychological events, with some variables more closely related to the policy itself (policy-specific variables) and other variables that are more downstream from the policy, which have been identified by health behaviour and social psychological theories as being important causal precursors of behaviour (psychosocial mediators). We discuss the objectives of the ITC Project and its potential for building the evidence base for the FCTC.

  6. The conceptual framework of the International Tobacco Control (ITC) Policy Evaluation Project

    PubMed Central

    Fong, G T; Cummings, K M; Borland, R; Hastings, G; Hyland, A; Giovino, G A; Hammond, D; Thompson, M E

    2006-01-01

    This paper describes the conceptual model that underlies the International Tobacco Control Policy Evaluation Project (ITC Project), whose mission is to measure the psychosocial and behavioural impact of key policies of the Framework Convention on Tobacco Control (FCTC) among adult smokers, and in some countries, among adult non‐smokers and among youth. The evaluation framework utilises multiple country controls, a longitudinal design, and a pre‐specified, theory‐driven conceptual model to test hypotheses about the anticipated effects of specific policies. The ITC Project consists of parallel prospective cohort surveys of representative samples of adult smokers currently in nine countries (inhabited by over 45% of the world's smokers), with other countries being added in the future. Collectively, the ITC Surveys constitute the first‐ever international cohort study of tobacco use. The conceptual model of the ITC Project draws on the psychosocial and health communication literature and assumes that tobacco control policies influence tobacco related behaviours through a causal chain of psychological events, with some variables more closely related to the policy itself (policy‐specific variables) and other variables that are more downstream from the policy, which have been identified by health behaviour and social psychological theories as being important causal precursors of behaviour (psychosocial mediators). We discuss the objectives of the ITC Project and its potential for building the evidence base for the FCTC. PMID:16754944

  7. Hydraulic Model Investigation: Walnut Creek Flood-Control Project Contra Costa County, California.

    DTIC Science & Technology

    1987-10-01

    TECHNICAL REPORT HL-87-14 WALNUT CREEK FLOOD-CONTROL PROJECT CONTRA COSTA COUNTY, CALIFORNIA Hydraulic Model Investigation by W. G. Davis O11C tLE...34’ : AA Ii iA e d S O a :::: SCALE IN MILES 5 0 5 10 Figure 1. Vicinity map 4~ 4.. %- . " . " %____ WALNUT CREEK FLOOD-CONTROL PROJECT CONTRA COSTA COUNTY...Pleasant Hi-1, nd Martinez, California, on its way to the Suisin Bay. All of th.e planned imcrovements are located in Contra Costa County, California

  8. ERIP Project No. 670, Nevada Energy Control Systems, Inc.. Final techincal progress report

    SciTech Connect

    Kimber, D.J.

    1998-02-11

    In order to gauge the effectiveness of the ERIP Project No. 670, Nevada Energy Control Systems, Inc., Grant Number DE-FG01-96EE15670, the Statement of Work must be compared to the achievements by NECSI during the grant period. The following report reflects the aforementioned statement and is coordinated directly with it. The project goal is to gather data and test in order to validate earlier tests of energy savings,safety,reliability and practicality of the NECSI Evaporator Fan Controller in order to fully commercialize and market the product.

  9. Control room modernization at Finnish nuclear power plants - Two projects compared

    SciTech Connect

    Laarni, J.; Norros, L.

    2006-07-01

    The modernization of automation systems and human-machine interfaces is a current issue at both of the two nuclear power plants (i.e., Fortum's Loviisa plant and TVO's Olkiluoto plant) in Finland. Since the plants have been launched in the 1970's or 1980's, technology is in part old-fashioned and needs to be renewed. At Olkiluoto upgrades of the turbine operator systems have already been conducted; at Loviisa the first phase of the modernization project has just started. Basically, there is a question of the complete digitalization of the information streams at the two plants, and transition from a conventional hard-wired or hybrid control room to a screen-based one. The new human-machine interfaces will comprise new technology, such as PC workstations, soft control, touch screens and large-screen overall displays. The modernization of human-system interfaces is carried out in a stepwise manner at both plants. At both plants the main driver has not been the need to renew the user interfaces of the control room, but the need to upgrade the automation systems. In part because of this, there is a lack of a systematic top-down approach in which different aspects of human factors (HF) engineering are considered in relationship to higher level goals. Our aim here is to give an overview description of the control room modernization projects at the two plants and provide a preliminary evaluation of their progress to date. The projects are also compared, for example, in terms of duration, scope and phasing, and who is responsible for the realization of the project. In addition, we also compare experiences from the Finnish projects to experiences from similar projects abroad. The main part of the data used in this study is based on designers' and project members' interviews. (authors)

  10. Erosion-Resistant Nanocoatings for Improved Energy Efficiency in Gas Turbine Engines

    SciTech Connect

    2009-06-01

    This factsheet describes a research project whose goal is to test and substantiate erosion-resistant (ER) nanocoatings for application on compressor airfoils for gas turbine engines in both industrial gas turbines and commercial aviation.

  11. Surface Erosion and Flow

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 7 April 2003

    The mottled surface texture and flow features observed in this THEMIS image suggest materials may be, or have been, mixed with ice. There is also evidence in some areas for infilling of sediments as crater rims and ridges appear covered.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

    Image information: VIS instrument. Latitude 45.3, Longitude 48.8 East (311.2 West). 19 meter/pixel resolution.

  12. Controllable 3D Display System Based on Frontal Projection Lenticular Screen

    NASA Astrophysics Data System (ADS)

    Feng, Q.; Sang, X.; Yu, X.; Gao, X.; Wang, P.; Li, C.; Zhao, T.

    2014-08-01

    A novel auto-stereoscopic three-dimensional (3D) projection display system based on the frontal projection lenticular screen is demonstrated. It can provide high real 3D experiences and the freedom of interaction. In the demonstrated system, the content can be changed and the dense of viewing points can be freely adjusted according to the viewers' demand. The high dense viewing points can provide smooth motion parallax and larger image depth without blurry. The basic principle of stereoscopic display is described firstly. Then, design architectures including hardware and software are demonstrated. The system consists of a frontal projection lenticular screen, an optimally designed projector-array and a set of multi-channel image processors. The parameters of the frontal projection lenticular screen are based on the demand of viewing such as the viewing distance and the width of view zones. Each projector is arranged on an adjustable platform. The set of multi-channel image processors are made up of six PCs. One of them is used as the main controller, the other five client PCs can process 30 channel signals and transmit them to the projector-array. Then a natural 3D scene will be perceived based on the frontal projection lenticular screen with more than 1.5 m image depth in real time. The control section is presented in detail, including parallax adjustment, system synchronization, distortion correction, etc. Experimental results demonstrate the effectiveness of this novel controllable 3D display system.

  13. Auditory cortex controls sound-driven innate defense behaviour through corticofugal projections to inferior colliculus

    PubMed Central

    Xiong, Xiaorui R.; Liang, Feixue; Zingg, Brian; Ji, Xu-ying; Ibrahim, Leena A.; Tao, Huizhong W.; Zhang, Li I.

    2015-01-01

    Defense against environmental threats is essential for animal survival. However, the neural circuits responsible for transforming unconditioned sensory stimuli and generating defensive behaviours remain largely unclear. Here, we show that corticofugal neurons in the auditory cortex (ACx) targeting the inferior colliculus (IC) mediate an innate, sound-induced flight behaviour. Optogenetic activation of these neurons, or their projection terminals in the IC, is sufficient for initiating flight responses, while the inhibition of these projections reduces sound-induced flight responses. Corticocollicular axons monosynaptically innervate neurons in the cortex of the IC (ICx), and optogenetic activation of the projections from the ICx to the dorsal periaqueductal gray is sufficient for provoking flight behaviours. Our results suggest that ACx can both amplify innate acoustic-motor responses and directly drive flight behaviours in the absence of sound input through corticocollicular projections to ICx. Such corticofugal control may be a general feature of innate defense circuits across sensory modalities. PMID:26068082

  14. The interaction between soil erosion and soil organisms in temperate agroecosystems: nematode redistribution in tramlines

    NASA Astrophysics Data System (ADS)

    Baxter, Craig; Rowan, John S.; McKenzie, Blair M.; Neilson, Roy

    2014-05-01

    Arable agriculture presents a unique set of challenges, and one of the most important is soil erosion. Whilst policy and practice look towards sustainable intensification of production to ensure food security, fundamental gaps in our understanding still exist. The physical processes involved in the detachment, transport and deposition of soil are well characterised but further research considering chemical and nutrient transport, fertiliser and pesticide losses, and environmental impacts to downstream environments is still required. Furthermore the interaction between soil erosion and soil organisms have largely been ignored, even though soil organisms serve a myriad of functions essential in the provision of soil ecosystem goods and services. Here we present the findings of a field-scale experiment into soil biotic redistribution undertaken at the James Hutton Institute's Balruddery Farm, Scotland (Link Tramlines Project XDW8001). Farm vehicle-tyre wheelings left in arable fields (tramlines) to enable crop spraying during the crop growth cycle have been identified as key transport pathways for sediment and associated nutrients. We tested the hypothesis that soil organisms were also transported by tramline erosion. During the winter of 2012/13 an experiment was undertaken to measure soil organism export from unbound hillslope plots subject to four different tramline treatments set out in a randomised block design. We used soil nematodes as a model organism as they are ubiquitous and sensitive to disturbance and an established indicator taxa of biological and physico-chemical changes in soil. Tramline treatments included a control tyre (conventional tractor tyre), a control tyre with a sown tramline, a low pressure tyre with sown tramline, and a control tyre with a spiked harrow. Post-event sampling of rainfall events was undertaken, and a range of variables measured in the laboratory. The spiked harrow treatment produced the greatest overall reductions in nematode

  15. Processes of barrier island erosion

    SciTech Connect

    Sallenger, A.H. Jr. ); Williams, S.J. )

    1989-09-01

    During 1986, the US Geological Survey and the Louisiana Geological Survey began a 5-year study of the processes causing the extreme rates (up to 20 m/year) of erosion of Louisiana's barrier islands. These processes must be better understood in order to predict future erosion and to assess management and erosion mitigation plans. The study is divided into three parts: the geologic development of barrier islands, the critical processes leading to erosion, and applications of results. This paper provides an overview of the part of the study on critical processes. The process part includes modeling erosion of the barrier islands due to sea level rise, the net loss of sand offshore, gradients in longshore transport, and overwash. Evidence indicates that the low-lying barrier beaches on much of the Louisiana coast do not approach an equilibrium configuration. These beaches, which, in many places, are not protected by dunes, are overwashed even during moderate storms and apparently are not evolving to a configuration that limits overwash. As a result, even with stable sea level, the beaches will continue to overwash and migrate landward during storms. Commonly used methods of modeling beach response to rising sea level assume beaches approach an equilibrium configuration, hence applying these methods to coastal Louisiana is problematical.

  16. [Tooth erosion - a multidisciplinary approach].

    PubMed

    Strużycka, Izabela; Rusyan, Ewa; Bogusławska-Kapała, Agnieszka

    2016-02-01

    During the last decades, an increasingly greater interest in dental erosion has been observed in clinical dental practice, in dental public health and in dental research because prevalence of erosive tooth wear is still increasing especially in young age group of population. Erosive tooth wear is a multifactorial etiology process characterized by progressive loss of hard dental tissue. It is defined as the exogenous and/or endogenous acids dissolution of the dental tissue, without bacterial involvement. In the development of dental erosive wear, interactions are required which include chemical, biological, behavioral, diet, time, socioeconomic, knowledge, education, and general health factors. Examples of risk groups could be patients with eating disorders, like anorexia nervosa or bulimia nervosa, gastroesophageal reflux disease, chronic alcohol abuse or dependence. Special nutrition habits groups with high consumption of soft or sport drinks, special diets like vegetarian, vegan or raw food diet, the regular intake of drugs, medications and food supplements can also increase the risk for dental erosion. Comprehensive knowledge of the different risk and protective factors is a perquisite for initiating adequate preventive measures.

  17. ACFA 2020 - An FP7 project on active control of flexible fuel efficient aircraft configurations

    NASA Astrophysics Data System (ADS)

    Maier, R.

    2013-12-01

    This paper gives an overview about the project ACFA 2020 which is funded by the European Commission within the 7th framework program. The acronym ACFA 2020 stands for Active Control for Flexible Aircraft 2020. The project is dealing with the design of highly fuel efficient aircraft configurations and, in particular, on innovative active control concepts with the goal to reduce loads and structural weight. Major focus lays on blended wing body (BWB) aircraft. Blended wing body type aircraft configurations are seen as the most promising future concept to fulfill the so-called ACARE (Advisory Council for Aeronautics Research in Europe) vision 2020 goals in regards to reduce fuel consumption and external noise. The paper discusses in some detail the overall goals and how they are addressed in the workplan. Furthermore, the major achievements of the project are outlined and a short outlook on the remaining work is given.

  18. Deposition + Erosion = Textures

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 7 May 2003

    Toward the westernmost extent of the Medusae Fossae Formation, a 5000+ km long belt of eroding sediments, the interleaving of erosional surfaces produces dramatic textural variations. In the lower third of this image, the cross-hatched MFF layer is being stripped back from a surface that was already heavily eroded before the MFF layer was deposited. Also, note the sinuous and, in places, dendritic ridges that are either linear dunes or inverted channels.

    Image information: VIS instrument. Latitude -3.9, Longitude 154.1East (205.9). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  19. Channels and Erosion

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 20 June 2003

    The dissected and eroded channel observed in this THEMIS image taken of plains materials southwest of the volcano Elysium Mons shows typical erosional islands and depositional features. The interesting thing about this channel is that it appears to start out of nowhere. The MOLA context image shows that the channel originates from a fissure within the ground, whose origin is likely volcanic, but may also be related to volatile processes.

    Image information: VIS instrument. Latitude 19.5, Longitude 126.8 East (233.2 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  20. The Influence of Woodland Encroachment on Runoff and Erosion in Sagebrush Steppe Systems, Great Basin, USA.

    NASA Astrophysics Data System (ADS)

    Pierson, F. B.; Kormos, P. R.; Williams, C. J.

    2007-12-01

    Pinyon and juniper woodlands have expanded 10 to 30% in the past 30 years and now occupy nearly 20 million hectares of sagebrush shrub steppe in the Great Basin Region and Colorado Plateau, USA. The conversion of sagebrush steppe to pinyon and juniper woodlands has been linked to changes in plant community structure and composition and respective increases in overland flow and erosion from these landscapes. The Sagebrush Steppe Treatment Evaluation Project (SageSTEP, www.sagestep.org) was implemented in 2005 as a 5 year interdisciplinary research study to evaluate restoration methodologies for sagebrush rangelands degraded by woodland and grassland encroachment over a six state area within the Great Basin. The hydrology component of SageSTEP focuses on the relationships between changes in vegetation and groundcover and runoff/erosion processes. In 2006, 140 small scale (0.5 m2) rainfall simulations were conducted at 2 locations within the Great Basin to determine whether critical thresholds exist in vegetation and ground cover that significantly influence infiltration, runoff, and erosion in pinyon and juniper woodlands. Simulation plots were distributed on interspaces (areas between shrub/tree canopies) and juniper, pinyon, and shrub coppices (areas underneath canopy). Water drop penetration times and litter depths were also collected for each plot to explore controls on soil hydrophobicity. Preliminary results suggest a positive correlation between litter depth and hydrophobicity, as soils under thick pinyon and juniper coppices are strongly water repellant and soils in interspaces and under shrub coppices are easily wettable. Interspace plots with varying amounts of grasses and forbs have the highest erosion and runoff rates due to higher percentages of bare ground and relatively low soil stability. Pinyon coppices have the least runoff and erosion due to very high litter depths and low bare ground cover, even though surface soils are hydrophobic. Juniper and