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1

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

Code of Federal Regulations, 2014 CFR

... 3 2014-07-01 2014-07-01 false Small beach erosion control project authority (Section 103). 263.26 Section...PROGRAMS Shore Protection Policy § 263.26 Small beach erosion control project authority (Section 103). (a)...

2014-07-01

2

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

Code of Federal Regulations, 2012 CFR

... 3 2012-07-01 2012-07-01 false Small beach erosion control project authority (Section 103). 263.26 Section...PROGRAMS Shore Protection Policy § 263.26 Small beach erosion control project authority (Section 103). (a)...

2012-07-01

3

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

Code of Federal Regulations, 2013 CFR

... 3 2013-07-01 2013-07-01 false Small beach erosion control project authority (Section 103). 263.26 Section...PROGRAMS Shore Protection Policy § 263.26 Small beach erosion control project authority (Section 103). (a)...

2013-07-01

4

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

Code of Federal Regulations, 2011 CFR

... 3 2011-07-01 2011-07-01 false Small beach erosion control project authority (Section 103). 263.26 Section...PROGRAMS Shore Protection Policy § 263.26 Small beach erosion control project authority (Section 103). (a)...

2011-07-01

5

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

Code of Federal Regulations, 2010 CFR

... 3 2010-07-01 2010-07-01 false Small beach erosion control project authority (Section 103). 263.26 Section...PROGRAMS Shore Protection Policy § 263.26 Small beach erosion control project authority (Section 103). (a)...

2010-07-01

6

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

ERIC Educational Resources Information Center

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…

West, Peter; And Others

7

Erosion Control Measures  

NSDL National Science Digital Library

This lesson will discuss erosion control practices in the agricultural and construction environments. The impact of erosion management practices will be demonstrated with exercises using a USLE calculator.

8

Erosion Control Progress in the HUA IDAHO SNAKE-PAYETTE RIVERS --HUA WATER QUALITY PROJECT FINAL REPORT  

E-print Network

Erosion Control Progress in the HUA IDAHO SNAKE-PAYETTE RIVERS -- HUA WATER QUALITY PROJECT FINAL HUAWater Quality Project encompassing Canyon, Gem, Payette, and Washington counties in southwestern Idaho. Washington Payette Gem Canyon BUL 808 The Idaho Snake-Payette Rivers Hydrologic Unit Water Quality Project

O'Laughlin, Jay

9

Projected changes in US erosivity  

NASA Astrophysics Data System (ADS)

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.

Biasutti, M.; Seager, R.

2015-02-01

10

Controlled Ultrasound Tissue Erosion  

PubMed Central

The ability of ultrasound to produce highly controlled tissue erosion was investigated. This study is motivated by the need to develop a noninvasive procedure to perforate the neonatal atrial septum as the first step in treatment of hypoplastic left heart syndrome. A total of 232 holes were generated in 40 pieces of excised porcine atrial wall by a 788 kHz single-element transducer. The effects of various parameters [e.g., pulse repetition frequency (PRF), pulse duration (PD), and gas content of liquid] on the erosion rate and energy efficiency were explored. An Isppa of 9000 W/cm2, PDs of 3, 6, 12, and 24 cycles; PRFs between 1.34 kHz and 66.7 kHz; and gas saturation of 40–55% and 79–85% were used. The results show that very short pulses delivered at certain PRFs could maximize the erosion rate and energy efficiency. We show that well-defined perforations can be precisely located in the atrial wall through the controlled ultrasound tissue erosion (CUTE) process. A preliminary in vivo experiment was conducted on a canine subject, and the atrial septum was perforated using CUTE. PMID:15244286

Xu, Zhen; Ludomirsky, Achiau; Eun, Lucy Y.; Hall, Timothy L.; Tran, Binh C.; Fowlkes, J. Brian; Cain, Charles A.

2009-01-01

11

Erosion Control for Local Roads  

E-print Network

Erosion Control Handbook for Local Roads M I N N E S OT A DEPARTME N T OF T R A N S PORTATION was extremely helpful in identifying key issues and concerns of those responsible for controlling erosion on low. This report does not constitute a standard, specification, or regulation. 2 #12;Table of Contents Erosion

Minnesota, University of

12

Weathering and Erosion Video Project  

NSDL National Science Digital Library

Using a digital video recorder, 6th grade students will create an informational video that teaches 4th grade (or 5th as an FCAT review) students about weathering and erosion using images from around the school and local areas. This will most likely be a long-term project, depending on how many digital video recorders and computers are available.

Amber Thibedeau

2012-07-25

13

Ceramic corrosion/erosion project description  

SciTech Connect

As a part of the United States Department of Energy's High Temperature Turbine Technology Program, the Morgantown Energy Technology Center is participating in a Ceramics Corrosion/Erosion Materials Study. Objective is to create a technology base for ceramic materials which could be used by stationary gas power turbines operating with a high-temperature, coal-derived, low-Btu gas products of combustion environment. Two facilities are designed and installed to burn a varying low-Btu coal-derived gas in a controlled manner. This report contains the objectives and testing philosophy as well as the operating, specimen handling, and emergency procedures for the facilities. The facilities were checked out in August/September 1980. Testing is scheduled to begin in late 1980 with completion of 1000 hours of ceramic materials exposure to be completed by early 1981. Most of the enclosed is an update of two METC Information Releases (IR), i.e., IR 442 (1979) Test Plan for Ceramic Corrosion/Erosion Project, and IR 817 (1980) Ceramic Corrosion/Erosion Project Description.

Nakaishi, C.V.; Carpenter, L.K.

1981-02-01

14

Effectiveness of postfire erosion control treatments  

Technology Transfer Automated Retrieval System (TEKTRAN)

To mitigate potential postfire erosion and flooding, various erosion control treatments are applied on highly erodible areas with downstream resources in need of protection. Recent efforts to evaluate the effectiveness of postfire erosion mitigation treatments have used natural rainfall experiments...

15

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

SciTech Connect

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.

Antrim, L.D.; Thom, R.M.; Gardiner, W.W. [Battelle/Marine Sciences Lab., Sequim, WA (United States)

1993-09-01

16

The International Erosion Control Society - Photo Gallery  

NSDL National Science Digital Library

Users can access photographs of various forms of erosion, erosion damage, and "before and after" photos showing how the problem was brought under control. Each photograph is accompanied by a description of the activity which is taking place.

17

Coastal erosion project, Diani beach, Kenya  

Microsoft Academic Search

Master project report.\\u000aSince the seventies, the establishment of hotels and other facilities has increased the pressure on the Kenyan coast. During the last decade, hotel managers and residents in Diani Beach have been experiencing problems with erosion. The only measures taken to address the problem are individually built seawalls to protect private properties. These seawalls are mostly not properly

J. Ballot; C. Hoyng; I. Kateman; M. Smits; R. De Winter

2006-01-01

18

Soil Erosion Control After Wildfire  

NSDL National Science Digital Library

The potential for severe soil erosion is a consequence of wildfire because as a fire burns it destroys important plant material and the litter layer that stabilizes soil and slows water movement after severe rainstorms. This information sheet discusses how intense heat from fire can make soils hydrophobic, or water repellent, and identifies the actions landowners can take to minimize erosion after a fire.

19

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.

20

Application of the Water Erosion Prediction Project (WEPP) Model for Soil Erosion Estimation and Conservation Planning  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Water Erosion Prediction Project (WEPP) model is a process-based, continuous- simulation, distributed parameter erosion simulation model for application to field-scale hillslope profiles and small watersheds. Developed over the past 25 years by the United States Department of Agriculture, it con...

21

Using Compost for Erosion Control and Revegetation  

E-print Network

and to retain sediment (Fig. 4). Another applications at a West Texas municipal landfill uses compost produced from a mixture of poultry manure, sawdust and other wood residuals to control erosion, as a soil amendment and to create a vegetated cover over... closed landfill cells. TxDOT accepts high-quality compost, such as dairy manure compost, for use in compost-manufactured topsoil (CMT), in erosion-control compost (ECC) and as general- use compost (GUC) (TxDOT Special Specification 161, Compost). Tx...

Mukhtar, Saqib

2005-08-08

22

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...

23

International Erosion Control Association www.ieca.org  

E-print Network

International Erosion Control Association www.ieca.org October 1, 2009 TO: Professors Chapter of the International Erosion Control Association, I am very pleased to announce a scholarship opportunity for students considering a career in a field related to sediment and erosion control. Amount

Ma, Lena

24

7 CFR 3201.68 - Erosion control materials.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Erosion control materials. 3201.68 Section...PROCUREMENT Designated Items § 3201.68 Erosion control materials. (a) Definition...or other sites to prevent wind or water erosion of loose earth surfaces, which may...

2013-01-01

25

7 CFR 3201.68 - Erosion control materials.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Erosion control materials. 3201.68 Section...PROCUREMENT Designated Items § 3201.68 Erosion control materials. (a) Definition...or other sites to prevent wind or water erosion of loose earth surfaces, which may...

2012-01-01

26

7 CFR 3201.68 - Erosion control materials.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 2014-01-01 false Erosion control materials. 3201.68 Section...PROCUREMENT Designated Items § 3201.68 Erosion control materials. (a) Definition...or other sites to prevent wind or water erosion of loose earth surfaces, which may...

2014-01-01

27

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...

28

RESIDUE CHARACTERISTICS FOR WIND AND WATER EROSION CONTROL  

Technology Transfer Automated Retrieval System (TEKTRAN)

Standing residue is an effective means of controlling erosion and preventing dust emission in areas prone to wind erosion. In northern climates, standing stubble retains snow deposits and enhances soil water, and in areas affected by water erosion, surface residue is an effective means of protecting...

29

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

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.

Rebich, R.A.

1995-01-01

30

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...

31

Robotic weld overlay coatings for erosion control  

NASA Astrophysics Data System (ADS)

Research is being conducted to develop criteria for selecting weld overlay coatings for erosion mitigation in circulated fluidized beds. Twelve weld overlay alloys were deposited on 1018 steel substrates using plasma arc welding. Ten samples from each coating were prepared for erosion testing. All selected coatings were erosion tested at 400C and their erosion resistance and microstructure evaluated. Steady state erosion rates were similar for several weld overlay coatings (Ultimet, Inconel-625, Iron-Aluminide, 316L SS, and High Chromium Cast Iron) and were considerably lower than the remaining coating evaluated. These coatings had different base (Co, Fe, Ni-base). No correlations were found between room temperature microhardness of the weld overlay coatings and their erosion resistance at elevated temperature, although this criteria is often thought to be an indicator of erosion resistance. It was suggested that the coatings that showed similar erosion rates may have similar mechanical properties such as fracture strength, toughness and work hardening rates at this temperature. During the past quarter, Iron-Aluminide, Inconel-625, and 316L SS coatings were selected for more detailed investigations based upon the preliminary erosion test results. Microhardness tests were performed on eroded samples to determine the size of the work hardened zone and change in coatings hardness due to erosion. The work hardened zone was correlated with erosion resistance of the coatings. Additional Iron-Aluminide, Inconel-625, and 316L SS coatings were deposited on 1018 steel substrates.

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

1994-01-01

32

Can control of soil erosion mitigate water pollution by sediments?  

PubMed

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 express in monetary terms. PMID:23815978

Rickson, R J

2014-01-15

33

Improving frost-simulation subroutines of the Water Erosion Prediction Project (WEPP) model  

Technology Transfer Automated Retrieval System (TEKTRAN)

Erosion models play an important role in assessing the influence of human activities on the environment. For cold areas, adequate frost simulation is crucial for predicting surface runoff and water erosion. The Water Erosion Prediction Project (WEPP) model, physically-based erosion-prediction softwa...

34

Weld overlay coatings for erosion control  

SciTech Connect

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).

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

1993-03-03

35

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

NASA Astrophysics Data System (ADS)

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 as planned. For comparison of techniques, we will consider installing check dams in comparable gullies. The October 2013 project will also focus on training the community how to conduct erosion control site assessments, design site-appropriate structures, and implement erosion control and revegetation plans. Following the training, the community will teach these skills to adjacent villages.

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

2013-12-01

36

Exploring monsoonal controls on Himalayan erosion  

NASA Astrophysics Data System (ADS)

The impact of climatic changes on erosion rates is one of the currently most debated topics in geomorphology and is central in the discussion of feedbacks between Late Cenozoic climate change and tectonics. Considering a simple discharge-based erosion law, a wetter climate is commonly associated with higher erosion rates. However, in the presence of an erosion threshold, the variability of discharge events can have a pronounced effect on the long-term erosional efficiency of a certain climate. While this effect is considered to be potentially important, relatively few observations exist that help testing this hypothesis. Available erosion rate data from the Siwaliks, the Himalaya, and the eastern margin of the Tibetan Plateau show markedly different relationships between erosion rates and normalized channel steepness, pointing at first-order differences between these regions. Erosion rates in the Siwaliks are over an order of magnitude higher compared to the other two regions while channel steepness indices are amongst the lowest. In the Himalaya and eastern Tibet, channel steepness indices are similar at low erosion rates, but consistently higher in the Himalaya for increasing channel steepness indices. While differences in substrate erodibility may serve to explain the different relationships in the Siwaliks and the Himalaya, the observed differences between the Himalaya and eastern Tibet are more likely due to climatic factors, as lithologic variations within the regions are greater than between the regions. Here, we use a generalized stream power incision model that includes a threshold for incision and explore how differences in mean annual runoff and discharge variability help explaining the different trends of channel steepness indices and erosion in the Himalaya and eastern Tibet. We augment our study with analysis of discharge records from both regions to derive a functional description of the distribution of monsoonal floods. Importantly, our representation of flood discharges, allows us to explore the effect of variations in monsoon strength on erosional efficiency.

Scherler, D.; Avouac, J.

2013-12-01

37

Erosion  

NSDL National Science Digital Library

Soil erosion is a global problem. Each year, erosion costs billions of dollars in loss of land productivity, damage from soil sediment deposition and subsequent restoration costs, and harm to plant, animal, and human health due to air and water pollution. This lesson will consider the impacts of erosion at local, regional, national, and international levels. It will discuss how erosion occurs and the main factors that contribute to erosion. In addition, the different types of water and wind erosion will be discussed.The lesson is written to target educational needs of lower level undergraduate students and is open for use by the public and educational institutions. Depending on the goals/objectives of a course, training, workshop, part or all sections of the lesson could be used.

38

18 CFR 1304.202 - General sediment and erosion control provisions.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 false General sediment and erosion control provisions. 1304.202 Section... § 1304.202 General sediment and erosion control provisions. (a) During construction...activities, TVA shall require that appropriate erosion and sediment control measures be...

2014-04-01

39

18 CFR 1304.202 - General sediment and erosion control provisions.  

Code of Federal Regulations, 2013 CFR

...2012-04-01 true General sediment and erosion control provisions. 1304.202 Section... § 1304.202 General sediment and erosion control provisions. (a) During construction...activities, TVA shall require that appropriate erosion and sediment control measures be...

2013-04-01

40

18 CFR 1304.202 - General sediment and erosion control provisions.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false General sediment and erosion control provisions. 1304.202 Section... § 1304.202 General sediment and erosion control provisions. (a) During construction...activities, TVA shall require that appropriate erosion and sediment control measures be...

2012-04-01

41

18 CFR 1304.202 - General sediment and erosion control provisions.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false General sediment and erosion control provisions. 1304.202 Section... § 1304.202 General sediment and erosion control provisions. (a) During construction...activities, TVA shall require that appropriate erosion and sediment control measures be...

2011-04-01

42

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

Code of Federal Regulations, 2011 CFR

... 2011-10-01 false Control of erosion, sedimentation, and pollution. 436...Contract Clauses 436.574 Control of erosion, sedimentation, and pollution. ...the clause at 452.236-74, Control of Erosion, Sedimentation and Pollution, if...

2011-10-01

43

18 CFR 1304.202 - General sediment and erosion control provisions.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false General sediment and erosion control provisions. 1304.202 Section... § 1304.202 General sediment and erosion control provisions. (a) During construction...activities, TVA shall require that appropriate erosion and sediment control measures be...

2010-04-01

44

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

Code of Federal Regulations, 2011 CFR

... 2011-10-01 false Control of Erosion, Sedimentation, and Pollution. 452...Clauses 452.236-74 Control of Erosion, Sedimentation, and Pollution. As...insert the following clause: Control of Erosion, Sedimentation, and Pollution...

2011-10-01

45

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

Code of Federal Regulations, 2010 CFR

... 2010-10-01 false Control of erosion, sedimentation, and pollution. 436...Contract Clauses 436.574 Control of erosion, sedimentation, and pollution. ...the clause at 452.236-74, Control of Erosion, Sedimentation and Pollution, if...

2010-10-01

46

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

Code of Federal Regulations, 2010 CFR

... 2010-10-01 false Control of Erosion, Sedimentation, and Pollution. 452...Clauses 452.236-74 Control of Erosion, Sedimentation, and Pollution. As...insert the following clause: Control of Erosion, Sedimentation, and Pollution...

2010-10-01

47

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

Code of Federal Regulations, 2012 CFR

...Control of erosion, sedimentation, and pollution. 436.574 Section 436.574 ...Control of erosion, sedimentation, and pollution. The contracting officer shall insert...Control of Erosion, Sedimentation and Pollution, if there is a need for applying...

2012-10-01

48

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

Code of Federal Regulations, 2013 CFR

...Control of Erosion, Sedimentation, and Pollution. 452.236-74 Section 452.236-74...Control of Erosion, Sedimentation, and Pollution. As prescribed in 436.574, insert...Control of Erosion, Sedimentation, and Pollution (NOV 1996) (a) Operations...

2013-10-01

49

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

Code of Federal Regulations, 2012 CFR

...Control of Erosion, Sedimentation, and Pollution. 452.236-74 Section 452.236-74...Control of Erosion, Sedimentation, and Pollution. As prescribed in 436.574, insert...Control of Erosion, Sedimentation, and Pollution (NOV 1996) (a) Operations...

2012-10-01

50

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

Code of Federal Regulations, 2014 CFR

...Control of Erosion, Sedimentation, and Pollution. 452.236-74 Section 452.236-74...Control of Erosion, Sedimentation, and Pollution. As prescribed in 436.574, insert...Control of Erosion, Sedimentation, and Pollution (NOV 1996) (a) Operations...

2014-10-01

51

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

Code of Federal Regulations, 2013 CFR

...Control of erosion, sedimentation, and pollution. 436.574 Section 436.574 ...Control of erosion, sedimentation, and pollution. The contracting officer shall insert...Control of Erosion, Sedimentation and Pollution, if there is a need for applying...

2013-10-01

52

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

Code of Federal Regulations, 2014 CFR

...Control of erosion, sedimentation, and pollution. 436.574 Section 436.574 ...Control of erosion, sedimentation, and pollution. The contracting officer shall insert...Control of Erosion, Sedimentation and Pollution, if there is a need for applying...

2014-10-01

53

Erosion  

NSDL National Science Digital Library

In this activity, learners model erosion using a clear shoebox and sand or soil. Learners observe and discuss wind and water erosion in action and determine what effect sod and rocks have on their model. They examine gullies, valleys, landslides, and waves. During the investigation, learners draw diagrams of what they see. Later in the activity, learners take a walking field trip and look for evidence of erosion. They record their observations and explanations in a science log.

2012-06-26

54

DEMONSTRATION OF EROSION AND SEDIMENT CONTROL TECHNOLOGY. LAKE TAHOE REGION OF CALIFORNIA  

EPA Science Inventory

A three-year project was conducted by the California State Water Resources Control Board to determine methods of preventing and correcting erosion problems which severely effect the quality of the waters of the State of California. Two-project sites were chosen in the vicinity of...

55

Erosion by water and sediment control: Amendment techniques  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soil erosion by water and wind are worldwide problems and serious threats to profitability and sustainability of agriculture. Soil amendments are effective means for controlling soil erosion and improving crop production. Soil amendments are materials added to soil to improve chemical, physical, a...

56

Erosion  

NSDL National Science Digital Library

Students will design and conduct an open-ended investigation using a variety of earth materials to answer a question posed by the teacher: How does the erosion of sand compare with the erosion of gravel? After producing evidence that addresses this question, they will generate their own question that could be answered with further scientific inquiry.

PALS-Performance Assessment Links in Science

2012-04-24

57

Effects of Rising Relative Energy Prices on Soil Erosion and Its Control  

Microsoft Academic Search

Efforts to develop public programs to control soil erosion should not ignore other economic trends which may affect soil erosion. This programming analysis considers the impact of rising relative energy prices on cropland erosion in conjunction with alternative erosion control policies. Higher relative energy prices are found to reduce soil erosion significantly, complement soil loss restriction policies, and have an

John Miranowski; L. Zinser; James S. Shortle; Michael J. Monson

1985-01-01

58

Using a Stream Table to Investigate Erosion Control  

NSDL National Science Digital Library

This activity will introduce students to water-induced topsoil erosion and different ways to control it. Using a stream table (prepared by the teacher), they will vary the surface of the 'soil', and the height of the table, pour in water, and observe sheet, rill, and gully erosion. They can also investigate the effects of check dams (by plugging gullies with pebbles), observe the results of contour plowing, and test the effectiveness of different types of mulch (straw, shredded paper, pine needles, etc.) in preventing erosion. Instructions for constructing a stream table, a student worksheet, and discussion questions are provided.

2005-10-06

59

Controlling template erosion with advanced cleaning methods  

NASA Astrophysics Data System (ADS)

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.

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

60

Implementation of Channel-Routing Routines in the Water Erosion Prediction Project (WEPP) Model  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Water Erosion Prediction Project (WEPP) model is a process-based, continuous-simulation, watershed hydrology and erosion model. It is an important tool for water erosion simulation owing to its unique functionality in representing diverse landuse and management conditions. Its applicability is l...

61

ACOUSTIC PROFILING OF SEDIMENT ACCUMULATION IN THREE SMALL EROSION CONTROL RESERVOIRS IN NORTH MISSISSIPPI  

Technology Transfer Automated Retrieval System (TEKTRAN)

In Northern Mississippi, as part of a preventative erosion control program, the Yazoo-Little Tallahatchie Project (YLTP) created a system of small dams and reservoirs to regulate stream flow and to stop the movement of sediment over large distances. These structures were designed to have a lifetime ...

62

Erosion  

NSDL National Science Digital Library

Relate the building up and breaking down of the Earth\\'s surface over time to the various physical land features. Some of the amazing land forms we see in the world are formed by erosion. A lot of these land forms are found in the United States. Can you think of a few landforms you have heard of in the United States? Write a few of them ...

wstewart

2007-10-08

63

Management of Winter Soil Temperatures to Control Streambank Erosion  

E-print Network

recognized by agriculturists, silviculturists, and engineers as impor tant mechanisms of soil aggregateManagement of Winter Soil Temperatures to Control Streambank Erosion CAROLYN BORN! Range, Wildlife and Forestry Department University of Nevada-Reno Reno, Nevada 89512 USA Abstract.-Winter soil temperatures

64

Geologic controls of erosion and sedimentation on Mars  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

65

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...

66

Use of palm-mat geotextiles for rainsplash erosion control  

NASA Astrophysics Data System (ADS)

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 Borassus mats, were not effective in rainsplash erosion control. Both mats did not significantly ( P > 0.05) improve selected soil properties (i.e., soil organic matter, particle size distribution, aggregate stability and total soil carbon) as soil organic matter (SOM) input from mat-decomposition was much less than total SOM content. However, the changes in fine and medium sand contents (after 2 years) in the Borassus covered plots were significantly ( P < 0.05; n = 6) related to the total rainsplash erosion during 2007?2009. Emplacement of Borassus and Buriti mats on bare soils did not decrease SOM contents after 2 years, indicating that improvements in some soil properties might occur over longer durations. After ˜ 10 months, Buriti mats lost ˜ 70% of their initial weight ( P < 0.001) and their initial cover percentage ( C, %) decreased drastically ( P < 0.05); whereas, Borassus mats maintained similar C to the initial condition, although mass per unit area decreased by ˜ 20% ( P < 0.05). Moreover, the functional longevity of Borassus mats was ˜ 2 years against only 1 year for Buriti mats. Hence, use of Borassus mats is highly effective for rainsplash erosion control in the UK.

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

2010-07-01

67

Adapting the Water Erosion Prediction Project (WEPP) Model to Forest Conditions  

Microsoft Academic Search

Abstract.Adequate and reliable erosion prediction tools are needed for sound forest resources management. Numerous watershed models have been developed during the past. These models, however, are often limited in their applications largely due to their inappropriate representations of the hydrological processes involved. The Water Erosion Prediction Project (WEPP) model has demonstrated its usefulness in certain forest applications, such as modeling

Joan Q. Wu; William J. Elliot

2006-01-01

68

Water Erosion Prediction Project (WEPP) –Development History, Model Capabilities and Future Enhancements  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Water Erosion Prediction Project (WEPP) was initiated in August 1985 to develop new generation water erosion prediction technology for use by federal agencies involved in soil and water conservation and environmental planning and assessment. Developed by USDA-ARS as a replacement for empirically...

69

Adapting the Water Erosion Prediction Project (WEPP) Model for Forest Applications  

Technology Transfer Automated Retrieval System (TEKTRAN)

There 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 usef...

70

A Comparison of Erosion and Water Pollution Control Strategies for an Agricultural Watershed  

Microsoft Academic Search

The effectiveness and efficiency of two erosion control strategies and one water pollution control (riparian) strategy are compared for Idaho's Tom Beall watershed. Erosion control strategies maximize annualized net returns per hectare on each field and restrict field erosion rates to no more than 11.2 or 16.8 tons per hectare. The riparian strategy uses good vegetative cover on all fields

Tony Prato; Hongqi Shi

1990-01-01

71

A comparison of erosion and water pollution control strategies for an agricultural watershed  

Microsoft Academic Search

The effectiveness and efficiency of two erosion control strategies and one water pollution control (riparian) strategy are compared for Idaho's Tom Beall watershed. Erosion control strategies maximize annualized net returns per hectare on each field and restrict field erosion rates to no more than 11.2 or 16.8 tons per hectare. The riparian strategy uses good vegetative cover on all fields

Tony Prato; Hongqi Shi

1990-01-01

72

Erosion control and watershed management by Spacelab photography  

NASA Astrophysics Data System (ADS)

The interpretability of false color Spacelab photographs for erosion control and water shed management was assessed using photos taken over Nepal and the Mount Everest Massif. The thematic interpretation was done by a geologist working in this region. Scale limitations, image reproduction, and filtering of the photographs are discussed. Results show that much information can be extracted using relatively simple means. Color infrared photography must be used since panchromatic imagery does not show enough detail.

Koelbl, O.; Depury, P.

1985-04-01

73

Modeling of technical soil-erosion control measures and its impact on soil erosion off-site effects within urban areas  

NASA Astrophysics Data System (ADS)

The paper presents results of surface runoff, soil erosion and sediment transport modeling using Erosion 3D software - physically based mathematical simulation model, event oriented, fully distributed. Various methods to simulate technical soil-erosion conservation measures were tested, using alternative digital elevation models of different precision and resolution. Ditches and baulks were simulated by three different approaches, (i) by change of the land-cover parameters to increase infiltration and decrease flow velocity, (ii) by change of the land-cover parameters to completely infiltrate the surface runoff and (iii) by adjusting the height of the digital elevation model by "burning in" the channels of the ditches. Results show advantages and disadvantages of each approach and conclude suitable methods for combinations of particular digital elevation model and purpose of the simulations. Further on a set of simulations was carried out to model situations before and after technical soil-erosion conservation measures application within a small catchment of 4 km2. These simulations were focused on quantitative and qualitative assessment of technical soil-erosion control measures impact on soil erosion off-site effects within urban areas located downstream of intensively used agricultural fields. The scenarios were built upon a raster digital elevation model with spatial resolution of 3 meters derived from LiDAR 5G vector point elevation data. Use of this high-resolution elevation model allowed simulating the technical soil-erosion control measures by direct terrain elevation adjustment. Also the structures within the settlements were emulated by direct change in the elevation of the terrain model. The buildings were lifted up to simulate complicated flow behavior of the surface runoff within urban areas, using approach of Arévalo (Arévalo, 2011) but focusing on the use of commonly available data without extensive detailed editing. Application of the technical soil-erosion control measures induced strong change in overall amount of eroded/deposited material as well as spatial erosion/deposition patterns within the settlement areas. Validation of modeled scenarios and effects on measured data was not possible as no real runoff event was recorded in the target area so the conclusions were made by comparing the different modeled scenarios. Advantages and disadvantages of used approach to simulate technical soil-erosion conservation measures are evaluated and discussed as well as the impact of use of high-resolution elevation data on the intensity and spatial distribution of soil erosion and deposition. Model approved ability to show detailed distribution of damages over target urban area, which is very sensitive for off-site effects of surface runoff, soil erosion and sediment transport and also high sensitivity to input data, especially to DEM, which affects surface runoff pattern and therefore intensity of harmful effects. Acknowledgement: This paper has been supported by projects: Ministry of the interior of the CR VG 20122015092, and project NAZV QI91C008 TPEO.

Dostal, Tomas; Devaty, Jan

2013-04-01

74

Postmine drainage reconstruction and erosion control at Trapper Mine in northwest Colorado  

SciTech Connect

Portions of five major drainageways and their tributaries were regraded and appropriately treated to reduce the erosion rate and assist in permanent channel stabilization at Trapper Mine (surface coal mine) in 1987, 1988, and 1989. A wide variety of erosion control materials, methods and sediment reducing measures were used in reconstructed drainageways and on adjacent sideslopes. Vegetation response, decreased flow rates and reduced gully formation were the primary factors in assessing the success of drainage reconstruction projects. Postmine herbaceous cover, above-ground primary production and woody stem density were evaluated in reconstructed drainage channels and compared to sample data from undisturbed premine drainage locations. As expected, vegetation measurements were lower in postmine drainages than in undisturbed drainages. However, considerable vegetation growth was reported in all reconstructed drainages at the conclusion of the initial growing season and during the second growing season. The mean herbaceous cover in postmine drainages was 39% compared to 71% in undisturbed sites in 1988. In 1989, canopy cover had increased to 60% in postmine drainages and decreased on undisturbed drainage segments to 69% cover. Herbaceous primary productions was severely limited in 1989 due to severe drought conditions. Flow rates were significantly reduced following the establishment of water harvesting techniques. Following treatments, the estimated erosion rate was reduced 24 times the pre-treatment erosion rates.

Agnew, W. [Trapper Mining, Inc., Craig, CO (United States); Humphries, H.B. [Colorado Mined Land Reclamation Division, Denver, CO (United States)

1990-12-31

75

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

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.

Not Available

1992-07-17

76

A Comparison of Erosion and Water Pollution Control Strategies for an Agricultural Watershed  

NASA Astrophysics Data System (ADS)

The effectiveness and efficiency of two erosion control strategies and one water pollution control (riparian) strategy are compared for Idaho's Tom Beall watershed. Erosion control strategies maximize annualized net returns per hectare on each field and restrict field erosion rates to no more than 11.2 or 16.8 tons per hectare. The riparian strategy uses good vegetative cover on all fields adjacent to the creek and in noncropland areas and the resource management system that maximizes annualized net returns per hectare on remaining fields. The Agricultural Nonpoint Source Pollution model is used to simulate the levels and concentrations of sediment, nitrogen, phosphorus, and chemical oxygen demand at the outlet of the watershed. Erosion control strategies generate less total erosion and water pollution but are less efficient than the riparian strategy. The riparian strategy is less equitable for farmers than the erosion control strategies.

Prato, Tony; Shi, Hongqi

1990-02-01

77

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...

78

A numerical investigation of solid particle erosion experienced within oilfield control valves  

Microsoft Academic Search

Sand particles, produced in addition to petroleum fluid, present a major erosional hazard to transport and process control equipment within the petroleum industry. Control valves are most susceptible to erosion due to their fundamental action, experiencing failure through loss of control in a matter of days in extreme cases. This paper presents a computational fluid dynamics erosion model which allows

Alister Forder; Martin Thew; David Harrison

1998-01-01

79

Backshore sill beach and dune erosion control system  

SciTech Connect

A backshore sill beach and dune erosion control system is described comprising: a supporting protective apron formed of weather and water resistant cloth. The apron includes a flat base portion and an angularly sloped portion extending seaward of the base portion, a toe scour anchor tube connected to the seaward end of the apron sloped portion, and longitudinal sand-filled geotextile containers placed upon the apron base portion each extending longitudinally shore parallel to the incoming surf. The sand-filled geotextile containers are specifically placed upon the beach in a pyramidal longitudinally extending shore parallel relation to an area being protected whereby wave action impacts upon relatively soft surfaces of the containers and is dissipated before normally impacting surfaces that would otherwise be eroded.

Sample, J.W.

1988-03-08

80

WATER EROSION PREDICTION PROJECT (WEPP) TECHNOLOGY FOR ASSESSMENT OF RUNOFF, SOIL LOSS AND SEDIMENT YIELD POTENTIAL  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Water Erosion Prediction Project (WEPP) model is a process-based, distributed parameter, continuous simulation computer program for estimation of runoff, soil loss and sediment yield from fields and small watersheds. In addition to having large databases for application to a multitude of U.S. s...

81

INVESTIGATION OF COMPOST BLANKETS FOR EROSION CONTROL UNDER CONCENTRATED FLOW CONDITIONS  

Microsoft Academic Search

Compost blankets are recognized as an ef- fective erosion control practice and have been utilized widely. While previous studies have proven that compost blankets can control erosion as well or better than tradi- tional methods under normal rainfall and sheet flow con- ditions, little attention has been paid on how compost will respond to concentrated flow conditions. The objec- tive

Xianben Zhu; Mark Risse

82

Current projects in Fuzzy Control  

NASA Technical Reports Server (NTRS)

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.

Sugeno, Michio

1990-01-01

83

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

NASA Technical Reports Server (NTRS)

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.

1978-01-01

84

Coastal Erosion Phenomenon in Nigeria: Causes, Control and Implications  

Microsoft Academic Search

Coastal erosion, which is a natural occurrence and process have become an increasing problem in many parts of the world as a result of the socio-economic impacts that are often associated with this event. Nigeria with about 853 km stretch of coastline has also been characterized with differing erosive activities; a result of combination of natural and anthropogenic forces. However,

Adeyinka Sunday Okude; Israel Ajewole Ademiluyi

85

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

...Erosion Control and Revegetation and Maintenance Plan and the Wetland and Waterbody Construction and Mitigation Procedures and Request...Erosion Control, Revegetation and Maintenance Plan (Plan) and Wetland and Waterbody Construction and Mitigation Procedures...

2011-11-07

86

Device Oriented Project Controller  

SciTech Connect

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.

Dalesio, Leo; Kraimer, Martin

2013-11-20

87

Use of calliandra–Napier grass contour hedges to control erosion in central Kenya  

Microsoft Academic Search

Contour hedgerow systems consisting of various combinations of tree and grass species can be used on sloping lands to minimize erosion, restore fertility, and improve crop productivity, but there is need to evaluate the effectiveness of each system for its suitability at any locality as effective erosion control. The objectives of this study were to determine the amount of soil

S. D. Angima; D. E. Stott; M. K. O’Neill; C. K. Ong; G. A. Weesies

2002-01-01

88

GEOLOGY, November 2009 975 Climate controls erosion and weathering on soil-mantled land-  

E-print Network

temperature and water through-flow rates. The effects of temperature and precipitation on chemical weathering of landscape change, and few have quantified the mechanisms by which climate influences erosion and weatheringGEOLOGY, November 2009 975 ABSTRACT Climate controls erosion and weathering on soil-mantled land

Heimsath, Arjun M.

89

Bedload transport controls intra-event bedrock erosion  

NASA Astrophysics Data System (ADS)

Fluvial bedrock incision constrains the pace of mountainous landscape evolution. Fluvial erosion processes have been described with incision models that are widely applied in river reach and catchment scale studies. However, so far, no linked field data set at the process scale had been published that allows to assess model requirements and adequacy. Here, we evaluate the predictive power of various incision models on data on hydraulics, bedload transport and erosion recorded on an artificial bedrock slab installed in a steep mountain stream for a single bedload transport event. The influence of transported bedload on erosion rate (the "tools effect") is shown to be dominant while other effects are of minor importance. Hence, a simple temporal distributed incision model in which erosion rate is proportional to bedload transport rate is proposed for transient local studies. This model can be site-calibrated with temporally lumped bedload and erosion data and its applicability can be assessed by visual inspection of the study site. Basic discharge-based models like derivatives of the stream power model family however, are adequate to reproduce the overall trend of the observed erosion rate, at least for the event on hand. This is relevant for long-term studies of e.g. landscape evolution with no interest in transient local behaviour.

Beer, A. R.; Turowski, J. M.

2015-01-01

90

Innovative erosion control involving the beneficial use of dredge material, indigenous vegetation and landscaping along the Lake Erie Shoreline  

Microsoft Academic Search

Current conventional erosion protection techniques are both costly and can detract from the natural environment. The purpose of this paper is to describe how Presque Isle State Park, located along the shoreline of Lake Erie in Pennsylvania, implemented a low-cost and innovative erosion protection project. Erosion within the back bay area of the park threatened the park's heavily used multi-purpose

Eugene J Comoss; Denise A Kelly; Harry Z Leslie

2002-01-01

91

USING THE WATER EROSION PREDICTION PROJECT (WEPP) MODEL TO SIMULATE FIELD-OBSERVED RUNOFF AND EROSION IN THE APENNINES MOUNTAIN RANGE, ITALY  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Water Erosion Prediction Project (WEPP) model was tested using data from a detailed field-scale study conducted on experimental plots in the Apennines Mountain Range, Northern Italy. Runoff, soil water and sediment data, together with weather information, were automatically collected on a contin...

92

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

SciTech Connect

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.

Ueda, T.; Nugraha, C.; Matsui, K.; Shimada, H.; Ichinose, M.; Gottfried, J. [Kyushu University, Fukuoka (Japan). Department of Earth Resources Engineering

2005-07-01

93

Stubble Mulch Management for Water Conservation and Erosion Control on Hardlands of the Southern Great Plains.  

E-print Network

LIBRARY A; & k!. COLl EGF f STUBBLE MULCH MANAGEMENT for Water Conservation and Erosion Control on Hardlands of the Southern Great Plains in cooperation with the UNITED STATES DEPARTMENT OF AGRICULTURE [Blank Page in Original Bulletin... STUBBLE MULCH MANAGEMENT For Water Conservation and Erosion Control Hardlands the Southern Great Plains CHARLES J. WHITFIELD, C. E. VAN DOREN and WENDELL JOHNSON* L EARNING to farm the heavy soils of the Southern Great Plains successfully has been...

Johnson, Wendell C. (Wendell Clifford); Van Doren, C. E.; Whitfield, Charles J. (Charles James)

1949-01-01

94

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

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

95

Erosion Basics  

NSDL National Science Digital Library

This homepage of Dr. Richard A. McLaughlin at North Carolina State University includes a four-part tutorial about soil erosion and mitigation. Slide presentations include an introduction to the factors that lead to soil erosion, a general discussion of soil characteristics and susceptibility to erosion, an overview of the formation of rills and gullies, and some examples of sediment transport dynamics and erosion reduction techniques. The site also features short videos that show tests of erosion control methods in an artificial environment.

Richard A. McLaughlin

96

Cover crops effectiveness for soil erosion control in Sicilian vineyard  

NASA Astrophysics Data System (ADS)

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.

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

2009-04-01

97

PUBLISHED ONLINE: 28 FEBRUARY 2010 | DOI: 10.1038/NGEO776 Landslide erosion controlled by hillslope material  

E-print Network

LETTERS PUBLISHED ONLINE: 28 FEBRUARY 2010 | DOI: 10.1038/NGEO776 Landslide erosion controlled belts are eroded by landslides, and landsliding is ultimately driven by the topographic relief produced by fluvial and glacial erosion1­5 . Landslide erosion rates are derived from estimates of landslide volume

Montgomery, David R.

98

Two case studies in river naturalization: planform migration and bank erosion control  

NASA Astrophysics Data System (ADS)

A sound understanding of river planform evolution and bank erosion control, along with integration of expertise from several disciplines is required for the development of predictive models for river naturalization. Over the last few years, several methodologies have been presented for naturalization projects, from purely heuristic to more advanced methods. Since the time and space scales of concern in naturalization vary widely, there is a need for appropriate tools at a variety of time and space scales. This study presents two case studies at different scales. The first case study describes the prediction of river planform evolution for a remeandering project based on a simplified two-dimensional hydrodynamic model. The second case study describes the applicability of a Computational Fluid Dynamics (CFD) model for evaluating the effectiveness of bank-erosion control structures in individual meander bends. Understanding the hydrodynamic influence of control structures on flow through bends allows accurate prediction of depositional and erosional distribution patterns, resulting in better assessment on river planform stability, especially for the case of natural complex systems. The first case study introduces a mathematical model for evolution of meandering rivers that can be used in remeandering projects. In United States in particular, several rivers have been channelized in the past causing environmental and ecological problems. Following Newton's third law, "for every action, there is a reaction", naturalization techniques evolve as natural reactive solutions to channelization. This model (herein referred as RVR Meander) can be used as a stand-alone Windows application or as module in a Geographic Information System. The model was applied to the Poplar Creek re-meanderization project and used to evaluate re-meandering alternatives for an approximately 800-meter long reach of Poplar Creek that was straightened in 1938. The second case study describes a streambank protection project using bendway weirs. In the State of Illinois, bendway weirs constructed of rock have been installed at hundreds of sites, especially on small streams, to control streambank erosion. Bendway weirs are low hard structures installed in the concave bank of a meander bend. Design criteria for these weirs are approximate and have not been rigorously evaluated for overall effectiveness at low-, medium- and high flows. This initial step of the study attempted to describe the hydrodynamics around the weirs and the influence of the hydrodynamic patterns on sediment transport (near-field and far-field). To do that, a state-of-the-art three-dimensional CFD model was used to simulate flow through meander bends where 3D velocity measurements have been obtained to validate model predictions at low stages. Results indicate that the weirs produce highly complex patterns of flow around the weirs, which in some cases may actually increase erosional potential near the outer bank. These two case studies represent components of an emerging initiative to develop predictive tools for naturalization over a range of spatial and temporal scales

Abad, J. D.; Guneralp, I.; Rhoads, B. L.; Garcia, M. H.

2005-05-01

99

The Use of Submerged Narrow-Crested Breakwaters for Shoreline Erosion Control  

Microsoft Academic Search

STAUBLE, D.K. and TABAR, J.R., 2003. The Use of Submerged Narrow-Crested Breakwaters for Shoreline Erosion Control. Journal of Coastal Research, 19(3), 684-722. West Palm Beach (Florida), ISSN 0749-0208. The performance of six installations of modular narrow-crested submerged breakwaters constructed of prefabricated concrete has been reviewed as a possible lower cost shoreline erosion prevention device. Two types of breakwaters that have

Donald K. Stauble; Jeffery R. Tabar

100

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

SciTech Connect

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.

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

1986-01-01

101

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

NASA Astrophysics Data System (ADS)

Soil Erosion is a natural process that shapes the Earth. Due to the impact of agriculture, soil erosion rates increase, landforms show gullies and rills, and soils are depleted. In the Mediterranean, wheat, olive and vineyards were the main agriculture products, but new plantations are being found in sloping terrain due to the drip-irrigation. This new strategy results in the removal of the traditional terraces in order to make suitable for mechanization the agriculture plantation. Citrus is a clear example of the impact of the new chemical agriculture with a high investment in herbicides, pesticides, mechanisation, land levelling and drip computer controlled irrigation systems. The new plantation of citrus orchards is found in the Mediterranean, but also in California, Florida, China and Brazil. Chile, Argentina, and South Africa are other producers that are moving to an industrial production of citrus. This paper shows how the citrus plantations are found as one of the most aggressive plantation due to the increase in soil erosion, and how we can apply successful control strategies. The research into the high erosion rates of citrus orchard built on the slopes are mainly found in China (Wu et al., 1997; Xu et al., 2010; Wang et al., 2011; Wu et al., 2011; Liu et al., 2011; Lü et al., 2011; Xu et al., 2012) and in the Mediterranean (Cerdà and Jurgensen, 2008; 2009; Cerdà et al., 2009a; 2009b; Cerdà et al., 2011; 2012) Most of the research done devoted to the measurements of the soil losses but also some research is done related to the soil properties (Lu et al., 1997; Lü et al., 2012; Xu et al., 2012) and the impact of cover crops to reduce the soil losses (Lavigne et al., 2012; Le Bellec et al., 2012) and the use of residues such as dried citrus peel in order to reduce the soil losses. There are 116 million tonnes of citrus produced yearly, and this affects a large surface of the best land. The citrus orchards are moving from flood irrigated to drip 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 approach. Catena, 85 (3), 231-236. Cerdà, A., Jurgensen, M.F., Bodi, M.B. 2009. Effects of ants on

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

2013-04-01

102

This project studied the effects of urbanization on flooding and erosion of small streams in the District of Columbia. The Hickey Run, which covers 1075 acres (435 ha)  

E-print Network

#12;ABSTRACT This project studied the effects of urbanization on flooding and erosion of small; in the Hickey Run and by 50% in the Watts Branch. Among many practical erosion mitigation measures, better land Study of Erosion and Sedimentation of Selected Small Streams in the District of Columbia By Dr. Fred M

District of Columbia, University of the

103

Agriculture and stream water quality: A biological evaluation of erosion control practices  

Microsoft Academic Search

Agricultural runoff affects many streams in North Carolina. However, there is is little information about either its effect on stream biota or any potential mitigation by erosion control practices. In this study, benthic macroinvertebrates were sampled in three different geographic areas of North Carolina, comparing control watersheds with well-managed and poorly managed watersheds. Agricultural streams were characterized by lower taxa

David R. Lenat

1984-01-01

104

Environmental evaluation of flue gas desulfurization gypsum as a BMP for erosion control  

Technology Transfer Automated Retrieval System (TEKTRAN)

Flue Gas Desulfurization Gypsum (FGDG) is produced from pollution control systems reducing sulfur dioxide emissions from thermo-electric coal-fired power plants. Natural gypsum and FGDG both have been shown to be useful in control of soil erosion. However, concerns have been raised recently by envir...

105

Erosion control on a steeply sloped pipeline right-of-way in southwestern Pennsylvania  

SciTech Connect

The results of precipitation on steeply sloped pipeline rights-of-way (ROWs) during the time between ROW rehabilitation and the establishment of a dense, self-sustaining vegetative ground cover can cause locally severe soil erosion. This erosion results in elevated sediment loads in receiving streams and increases the difficulty and costs of ROW maintenance. A field study was completed that compared the environmental effectiveness of nine treatments on a 28% ROW slope in southwestern Pennsylvania. The six erosion-control methods investigated in the study, selected to represent a wide range in material type and installation cost, were (1) heavy application of straw mulch, (2) light application of straw mulch, (3) processed wood fiber, (4) chemical soil binder, (5) paper strips in netting, and (6) light straw mulch with a tacking agent. Each of the test plots also received the basic treatment of limestone, fertilizer, and a seed mixture commonly used to rehabilitate ROWs in the region. Precipitation, runoff volumes, and sediment yields were measured on each of 51 plots for 45 precipitation events during the 18-month study. Vegetation data were collected by the point-intercept method four times during the study to determine the amount of plant cover and species composition. Differences in sediment yield were observed among methods and between ROW location, but plant cover development was not influenced by erosion-control method or location. The relationship between environmental and cost data indicated that, of the six erosion-control methods tested, a light application of straw mulch was the most effective erosion-control treatment. 19 refs., 2 figs., 6 tabs.

Zellmer, S.D.; Edgar, D.E. (Argonne National Lab., IL (USA)); Isaacson, H.R. (Gas Research Inst., Chicago, IL (USA))

1991-01-01

106

Sediment storage dam: A structural gully erosion control and sediment trapping measure, northern Ethiopia  

NASA Astrophysics Data System (ADS)

Gully erosion is a prime problem in Ethiopia. This study assessed the severity of gully erosion and the role of sediment storage dams (SSD) in restoring gullies and preventing further gully development, its sediment trapping efficacy (STE) and its capacity in converting degraded gully lands to productive land. On average 2.5 m deep, 6.6 m wide and 28.3 m long gullies were formed in Minizr watershed, northwest Ethiopia, in 2013. Concentrated surface runoff, traditional ditches, graded terraces without suitable water ways and road construction are the main causes of such serious gully erosion. Over grazing, tunnel flow and lack of proper immediate gully treatment actions after gully initiation are found to be additional causes of the problem. Gully erosion was also found as the major source of sediment for downstream rivers and water reservoirs. The annual volume of soil eroded from only four gullies was 1941.3 m3. To control gully erosion, SSDs were found to be important physical structures, which can trap significant amount of sediment within gullies and they can convert unproductive gully land to productive agricultural land for fruit and crop production. Eight SSDs trapped about 44*103 m3 of sediment within 2 to 8 years. Two representative SSDs constructed using gabion and stone were tested for their STE. Results showed that their efficacy was 74.1% and 66.4% for the gabion and stone SSDs, respectively. Six of the older SSDs were already full of sediment and created 0.75 ha of productive land within 2 to 8 years. SSDs best fits to treat large size and deep gullies where other gully control measures, check dams, could not function well. To prevent gully formation, controlling its causes that is avoiding traditional ditches, practicing grassed water ways to safely remove runoff water from graded terraces, integrated watershed and road side management practices are important solutions. KEY WORDS: Sediment storage dam, gully erosion, sediment trapping efficacy, productive land, Ethiopia

Mekonnen, Mulatie; Keesstra, Saskia; Baartman, Jantiene; Ritsema, Coen

2014-05-01

107

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

ERIC Educational Resources Information Center

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…

Strohbehn, Roger, Ed.

108

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...

109

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....

110

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

NASA Technical Reports Server (NTRS)

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.

Klein, S. B.

1980-01-01

111

Geotubes for erosion control along the Texas Gulf Intracoastal Waterway  

E-print Network

maintenance dredging project. A physical model built in a shallow water wave basin was used to model the effects of a passing barge on the hydrodynamics around a gesture. Results showed that velocities around the end of a gesture are the greatest and other...

Cobb, David Earl

1999-01-01

112

Controls of initial topography on temporal and spatial patterns of glacial erosion  

NASA Astrophysics Data System (ADS)

Here we investigate the influence of initial pre-glacial topography on spatial and temporal patterns of glacial erosion using numerical surface process modelling, including a higher order ice sheet model. First, we consider glacier dynamics when simulating glaciation in two real landscapes, representing plateau-type topography (southeast Australia) and characteristic steady-state fluvial topography (southern Taiwan). We find that the different initial landscape configurations result in distinctly different ice configurations and patterns of basal sliding. The sliding patterns are controlled by ice configuration and the resulting basal shear stresses and by the thermal properties at the base of the ice. We then investigate how these characteristic patterns of basal sliding control glacial erosion and long-term landscape evolution using synthetic representations of the two landscapes. The two landscape configurations result in markedly different spatial and temporal patterns of glacial erosion. However, the resulting landscapes may have similar morphology, irrespective of initial landscapes and glacial erosion patterns being significantly different. The numerical experiments also suggest that, in addition to basal temperature, basal shear stress is important in restricting long-term glacial erosion, which is relevant for the preservation of landforms during glaciations. Specifically, pre-glacial landforms may be eroded although they are initially protected by cold-based ice, when the ice configuration promotes significant basal shear stress (glacial erosion) at the edge of a plateau-like landscape. In contrast, pre-glacial landforms may be preserved irrespective of the ice being warm-based, when low gradients in the ice surface act to limit basal shear stress.

Pedersen, Vivi K.; Huismans, Ritske S.; Herman, Frédéric; Egholm, David L.

2014-10-01

113

7Be and hydrological model for more efficient implementation of erosion control measure  

NASA Astrophysics Data System (ADS)

Increased concern about the on-site and off-site impacts of soil erosion in agricultural and forested areas has endorsed interest in innovative methods to assess in an unbiased way spatial and temporal soil erosion rates and redistribution patterns. Hence, interest in precisely estimating the magnitude of the problem and therefore applying erosion control measures (ECM) more efficiently. The latest generation of physically-based hydrological models, which fully couple overland flow and subsurface flow in three dimensions, permit implementing ECM in small and large scales more effectively if coupled with a sediment transport algorithm. While many studies focused on integrating empirical or numerical models based on traditional erosion budget measurements into 3D hydrological models, few studies evaluated the efficiency of ECM on watershed scale and very little attention is given to the potentials of environmental Fallout Radio-Nuclides (FRNs) in such applications. The use of FRN tracer 7Be in soil erosion/deposition research proved to overcome many (if not all) of the problems associated with the conventional approaches providing reliable data for efficient land use management. This poster will underline the pros and cones of using conventional methods and 7Be tracers to evaluate the efficiency of coconuts dams installed as ECM in experimental field in Belgium. It will also outline the potentials of 7Be in providing valuable inputs for evolving the numerical sediment transport algorithm needed for the hydrological model on field scale leading to assess the possibility of using this short-lived tracer as a validation tool for the upgraded hydrological model on watershed scale in further steps. Keywords: FRN, erosion control measures, hydrological modes

Al-Barri, Bashar; Bode, Samuel; Blake, William; Ryken, Nick; Cornelis, Wim; Boeckx, Pascal

2014-05-01

114

Thermal load testing of erosion-monitoring beryllium marker tile for the ITER-Like Wall Project at JET  

Microsoft Academic Search

ITER-Like Wall Project has been launched at JET in order to perform a fully integrated test of plasma-facing materials. During the next major shutdown a full metal wall will be installed: tungsten in the divertor and beryllium in the main chamber. Beryllium erosion is one of key issues to be addressed. Special marker tiles have been designed for this purpose.

T. Hirai; J. Linke; M. Rubel; J. P. Coad; J. Likonen; C. P. Lungu; G. F. Matthews; V. Philipps; E. Wessel

2008-01-01

115

Sedimentation in three small erosion control reservoirs in northern Mississippi  

Technology Transfer Automated Retrieval System (TEKTRAN)

The water storage capacity and dam integrity of thousands of flood control reservoirs built since 1950 are potentially compromised by excessive impounded sediments. The fate of these structures depends on the amount and characteristics of this accumulated material. To aid in understanding the scop...

116

Offshore sand resources for coastal erosion control in Louisiana  

Microsoft Academic Search

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

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

1990-01-01

117

Gullying and erosion control 507 Copyright 2006 John Wiley & Sons, Ltd. Earth Surf. Process. Landforms 31, 507525 (2006)  

E-print Network

Gullying and erosion control at archaeological sites in Grand Canyon, Arizona Joel L. Pederson1 *, Paul A Present address: GeoGraphics, Inc., Logan, UT 84321, USA 3 Grand Canyon National Park, Flagstaff, AZ 86001, USA Abstract Gully erosion of cultural sites in Grand Canyon National Park is an urgent management

Pederson, Joel L.

118

Controlled ultrasound tissue erosion: The role of dynamic interaction between insonation and microbubble activity  

PubMed Central

Previous studies showed that ultrasound can mechanically remove tissue in a localized, controlled manner. Moreover, enhanced acoustic backscatter is highly correlated with the erosion process. “Initiation” and “extinction” of this highly backscattering environment were studied in this paper. The relationship between initiation and erosion, variability of initiation and extinction, and effects of pulse intensity and gas saturation on time to initiation (initiation delay time) were investigated. A 788-kHz single-element transducer was used. Multiple pulses at a 3-cycle pulse duration and a 20-kHz pulse repetition frequency were applied. ISPPA values between 1000 and 9000 W/cm2 and gas saturation ranges of 24%–28%, 39%–49%, and 77%–81% were tested. Results show the following: (1) without initiation, erosion was never observed; (2) initiation and extinction of the highly backscattering environment were stochastic in nature and dependent on acoustic parameters; (3) initiation delay times were shorter with higher intensity and higher gas saturation (e.g., the mean initiation delay time was 66.9 s at ISPPA of 4000 W/cm2 and 3.6 ms at ISPPA of 9000 W/cm2); and (4) once initiated by high-intensity pulses, the highly backscattering environment and erosion can be sustained using a significantly lower intensity than that required to initiate the process. PMID:15704435

Xu, Zhen; Fowlkes, J. Brian; Rothman, Edward D.; Levin, Albert M.; Cain, Charles A.

2009-01-01

119

Can Warmwater Streams Be Rehabilitated Using Watershed-Scale Standard Erosion Control Measures Alone?  

Microsoft Academic Search

Degradation of warmwater streams in agricultural landscapes is a pervasive problem, and reports of restoration effectiveness\\u000a based on monitoring data are rare. Described is the outcome of rehabilitation of two deeply incised, unstable sand-and-gravel-bed\\u000a streams. Channel networks of both watersheds were treated using standard erosion control measures, and aquatic habitats within\\u000a 1-km-long reaches of each stream were further treated by

F. Douglas Shields Jr; Scott S. Knight; Charles M. Cooper

2007-01-01

120

Consistency of Rain Splash Soil Erosion under Controlled Laboratory Flume Conditions  

NASA Astrophysics Data System (ADS)

Prediction of soil erosion is challenging due to the wide range of factors that can affect it. At the catchment scale, for instance, inconsistent soil erosion yields have been reported in numerous studies. Explanations involve nonlinearities in these contributing factors and their interactions (such as soil surface properties, precipitation characteristic, topography and land cover). Controlled laboratory flume experiments provide a means to improve our process physical understanding. Here, we report on experiments wherein the dependence of rain-splash soil erosion on the precipitation rate, area of soil exposed and initial soil conditions was investigated using laboratory flume experiments. The role of these factors on predicting experimental results was examined based on a prototype experiment and area-based approach. That is, we hypothesised that flume erosion can be predicted by a simple linear scaling of the different factors. Fourteen experiments were carried out in which we varied the precipitation rate (28, 60 and 74 mm/h), the fraction of surface rock fragments (20, 30, and 40%) and initial soil conditions (dry hand-cultivated, wet sealed-compacted and dry compacted). In addition, the influence of time was investigated by considering different experiment durations (2-5 h). In all experiments, we measured the discharge rate, the total sediment concentration and the sediment concentrations of the individual size classes at the flume exit. The presence of surface rock fragments on the soil surface prevents surface sealing and reduces the cross-sectional area available for flow, thereby affecting the development of steady-state equilibrium. Results revealed that, generally, estimates of the individual size classes' sediment concentrations, taking the exposed area into account, reproduce satisfactorily the measured data at steady state, independent of the initial conditions and rainfall intensity. Before steady state, however, the main feature in most sediment size classes is an early concentration peak, which was found not to be proportional to the area exposed and effective rainfall. Rather, results showed that the short time behaviour is mainly controlled by the soil antecedent and initial conditions, such as surface sealing, surface compaction and soil moisture. In addition, findings suggested that the larger size classes are more sensitive to prior soil conditions than the finer size classes. It was found, also, that this proportionality of erosion to area of exposed soil can be obtained for the entire erosive event under carefully controlled conditions. Steady state erosion rates, based on a prototype precipitation, were within a factor two of measured rates, for total and individual size classes. However, at short times, erosion due to raindrop splash is not proportionally controlled by the precipitation rate. Overall, the results thus indicate that, for a given soil, experimental data based on a given rainfall rate can be used as a rough estimator of the steady rate of erosion for a different rainfall rates.

Jomaa, Seifeddine; Barry, D. Andrew; Sander, Graham G.; Parlange, J.-Yves

2014-05-01

121

Offshore sand resources for coastal erosion control in Louisiana  

SciTech Connect

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.

Ramsey, K.E.; Penland, S.; McBride, R.A. (Louisiana Geological Survey, Baton Rouge (USA)); Suter, J.R. (Exxon Production Research, Houston, TX (USA)); Williams, J. (Geological Survey, Reston, VA (USA))

1990-09-01

122

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

USGS Publications Warehouse

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 mainly on landscape measures. Landscape measures include altered drainage and flooding patterns, altered cover types (e.g., conversion of bottomland hardwoods to agricultural crops, reforestation of cropland to bottomland hardwoods, and creation of riparian buffer strips), altered cropping and tillage patterns, altered routing of water, and creation of buffer strips along wetlands and channel margins. Channel measures include vegetative bank stabilization, grade control structures, and regulation of channel water volume and velocity. During the first year of the study, EPA decided not to fund the third phase of the project. This required considerable rescoping of the project with the result that application of the sediment mobilization, routing, and deposition models to various management alternatives and portions of the Yazoo Basin was somewhat restricted. We believe, however, that this report will provide a good understanding of the various modes of sediment mobilization, transport, and deposition within the Yazoo Basin, as well as of the role of bottomland hardwoods. The model developed in this study could be applied to a variety of management or mitigation alternatives prior to implementation to determine their relative effectiveness. Policy, political, and socio-economic consequences of any proposed management/mitigation practice, however, must ultimately be taken into consideration by those charged with management of water resources within the Yazoo Basin before any practice is implemented. This study makes no effort to judge the feasibility of management alternatives in this regard.

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

1988-01-01

123

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

PubMed

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 0.925 Pa, respectively. PMID:23717998

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

2013-01-01

124

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

NASA Astrophysics Data System (ADS)

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 significant differences between the systems referring to sediment yield and runoff amount respectively vegetation development.

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

2013-04-01

125

Vegetation cover plays the most important role in soil erosion control.  

PubMed

To obtain, characteristics and behaviors of soil erosion phenomena, to control it's harms and reduce it's risks, realistic data from soil erosion rates are necessary. Mean while, measuring soil erosion rates particularly in large scale is a time consuming and expensive task. Moreover, spatial and temporal changes of soil erosion increase this problem. Therefore, to find out a certain way of creating capable methods which easily and quickly be able to estimate soil erosion rate, is quite logical. So, different models are widely used, but, may be the most important consideration with this regard is that, these models should be previously, tested and adopted to defined areas to stop probability of causing some huge and meaningful errors. Therefore, to achieve the above mentioned aim, different methods are used. Anyway, conditions which resulted to create a suitable model, should be considered in a defined area where, model is applied, unless, model application can leads to huge risks. This study is an attempt with this refer, that is, with comparing measured soil loss rates and predicted soil erosion rates from a defined catchment area, created a reasonable relationship between them and achieved the main aim of the study. That is, one of the small upland catchments of Emam kandi of Urmia with 75 ha area which is part of the Urmia lake catchment area and under layned by calcareous parent material, is selected as a study site. Selected catchment has natural pasture and has closured during the recent years. To calculate sediment yield the following processes were done: first, estimating the volume of trapped sediments, then, surveying the catchment area, for calculating sediment yield. Measured sediment yield is 6.19 t ha(-1) year(-1) which leads to soil loss rate of 13.76 t ha(-1) year(-1) by using Sediment Delivery Ratio (SDR). Also, inside the measurement of sediment yields and calculation of soil loss rates, two models of MUSLE and PSIAC were used respectively after exclosure and before exclosure to predict soil loss rates. Predicted soil loss rates by MUSLE and PSIAC respectively are 12.80 and 26.5 t ha(-1) year(-1). Finally, Comparisons and statistical analysis and scientific discussions were made. PMID:19069506

Mahmoudzadeh, A

2007-02-01

126

Beach Erosion  

NSDL National Science Digital Library

The Beach Erosion site of the WhyFiles (last mentioned in the August 9, 1996 Scout Report), a project funded by the graduate school of the University of Wisconsin-Madison, has been recently updated. Its newest addition includes a story about the population of the tiny Pacific Island nation of Tuvalu that is preparing to abandon its home due to rising sea levels. The site takes a look at this subject and the resulting increased beach erosion that takes place around the world. Visitors can read about the physical processes of beach erosion, view a QuickTime movie of a house falling into the ocean, and more. The site includes good descriptions, photographs, and links to additional information (although some were broken at the time of this annotation), giving interested readers insight into this widespread phenomenon.

127

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

NASA Astrophysics Data System (ADS)

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.

O'Connor, M.; McDavitt, W.

2002-05-01

128

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

NASA Astrophysics Data System (ADS)

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.

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

1993-03-01

129

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)

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 with annual cultures or pastures. Data on climate, vegetation, hydrology and soil erosion will be collected at different spatial scales (hillslope, gullies, catchment), to allow for a correct calibration of the model in simulating the most important erosive processes for current conditions. Climate change scenarios for 2071-2100 will be downscaled for the study areas based on existing regional climate models through a statistical approach. Results are expected to provide insights on the erosive impacts of changes in key erosive factors, i.e.: rainfall regime, vegetation cover (including increased wildfire frequency), soil moisture and hydrological regimes. Impacts will be assessed in terms of soil loss at the slope scale, gully erosion processes and catchment sediment yield. Scenarios for land-use change and agroforestry adaptation due to climate change will also be developed and tested using the model. ERLAND will represent one of the few studies performed for Mediterranean conditions, and explicitly including gully erosion and sediment connectivity.

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

130

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

NASA Technical Reports Server (NTRS)

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 composite (ASTM D 4541 95 "Pull Off Strength of Coatings"). Glenn and Allison Advanced Development Company collaborated to optimize erosion coatings for gas turbine fan and compressor applications. All the coating systems survived aggressive thermal cycling without spalling. During erosion tests (see the final photo), the most promising coating systems tested had Cr3C2-NiCr and WC-Co as the hard topcoats. In all cases, these coating systems performed significantly better than that with a TiN hard topcoat. When material depth (thickness) loss is considered, the Cr3C2-NiCr and WC-Co coating systems provided, on average, an erosion resistance 8.5 times greater than that for the uncoated PMR 15/T650 35 composite. Similarly, Cr3C2-NiCr and WC-Co coating systems adhered to the PMC substrate during tensile tests significantly better than systems containing a TiN topcoat. Differences in topcoats of Cr3C2-NiCr and WC-Co were determined by considering issues such as cost and environmental impact. The preferred erosion-resistant coating system for PMR 15/T650 35 has WC-Co as the hard topcoat. This system provides the following benefits in comparison to the coating system with Cr3C2-NiCr topcoat: lower powder material cost (15 to 20 percent), environmentally friendly materials (Cr3C2-NiCr is hazardous), and higher deposition yield (10 to 15 percent), which results in less waste.

Sutter, James K.

2000-01-01

131

Can Warmwater Streams Be Rehabilitated Using Watershed-Scale Standard Erosion Control Measures Alone?  

NASA Astrophysics Data System (ADS)

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 ?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 measures are ineffective tools for ecosystem restoration in incised, warmwater streams of the Southeastern U.S., even if applied at the watershed scale and accompanied by significant reductions in suspended sediment concentration.

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

2007-07-01

132

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

NASA Astrophysics Data System (ADS)

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 soil, 2-Hydroseeding with a mix of grasses and legumes adapted for Mediterranean conditions, 3- Plantation of Mediterranean shrub species at a 1 plant m-2 density, 4- organic erosion control mat (made of coconut or esparto grass, Stipa tenacissima, fiber) plus hydroseeding. 5- synthetic net mat for erosion control plus hydroseeding. 6- synthetic 3D-net mat for erosion control plus hydroseeding. All the plots had an outlet with routed runoff and sediment to a sediment trap located at the base of the roadcut. The treatments were installed during early fall 2012. Since that date sediments were regularly collected and the evolution of vegetation was monitored. In four of the sites (the other two were vandalized) rainfall simulation experiments using a mesoplot rainfall simulator based on Sumner et al. (1996) were performed in summer 2013. The evaluation of vegetation cover and number of plants made in May, at the end of the rainy season, indicated how the hydroseeding treatments (the three mats plus the hydroseeding without mat) presented a relatively high ground cover (between 25 to 35 %) but with a relatively large standard deviation (around 25%). This variability was clearly related to site features (slope, parent material, and climate conditions for the year) with no clear differences among treatments. The plantation and control treatments presented a much lower ground cover, as expected, ranging, in average, from 5 to 10%. There was a large variability in the pattern of plant distribution within the plots, with site to site differences. So in sites 1, 2 and 5 there was a trend towards increased plant density in the lower area of the plot while in site 3 this trend was reversed and in sites 4 and 6 there was not a clear pattern. Sediment lost during the rainfall period, which ranged from 294 to 778 mm from October 1st to May 31st, presented a large variability among sites with maximum values ranging from 2.5 g m-2 (Fiñana) to 1800 (Mancha real). In all the sites there was a clear difference between the mat treatments which presented very low erosion rates, with

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

2014-05-01

133

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

Microsoft Academic Search

The role of forest stand density in controlling soil erosion was investigated in Ehime Prefecture, Japan. The main objective\\u000a was to compare soil erosion under different forest conditions including forest type, species composition, and stand density\\u000a as influenced by thinning operations. Relative yield index (Ry) was used as an indicator of stand density to reflect the degree\\u000a of management operations

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

2010-01-01

134

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

SciTech Connect

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.

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

1986-03-01

135

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

NASA Technical Reports Server (NTRS)

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.

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

1987-01-01

136

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

PubMed

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. PMID:23660520

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

2013-08-01

137

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

NASA Astrophysics Data System (ADS)

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 with dry conditions, allowing for sufficient regolith to build up on the hillslopes. Finally, this study suggests a strong control of orbitally and ice sheet forced latitudinal shifts of the ITCZ on the erosional gradients and sediment production on the western escarpment of the Peruvian Andes at 13° during the Minchin period. Accordingly, cut-and-fill sequences cannot only be inverted into contrasting erosional regimes, but also into different paleogeographic and paleoecological conditions.

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

2014-05-01

138

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

SciTech Connect

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.

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

1993-10-20

139

Coercive versus cooperative pollution control: Comparative study of state programs to reduce erosion and sedimentation pollution in urban areas  

NASA Astrophysics Data System (ADS)

This article examines coercive and cooperative approaches to implementing state urban erosion and sedimentation pollution control programs. State administrators report serious shortfalls in their ability to control sources of pollution, but comparison of more and less successful programs provides evidence of what states can do to make programs more effective. Key ingredients for a successful state effort include the use of coercion with both the private sector and local government, adequate staffing, application of severe sanctions when violations of state standards are detected, and provision of technical assistance. Many state programs lack one or more of those elements, which explains their inability to adequately control urban erosion and sedimentation pollution.

Burby, Raymond J.

1995-05-01

140

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...

141

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...

142

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

NASA Astrophysics Data System (ADS)

The energetic function of the soil expressed through the potential energy accumulated through humus, the biogeochemical function (the circuit of the nutrient elements) are significantly influenced by its hydrophysical function and especially by the state of the bedding- consolidation, soil capacity of retaining an optimal quantity of water, and then its gradual disponibility for plant consumption. The understanding of soil functions and management including nutrient production, stocking, filtering and transforming minerals, water , organic matter , gas circuit and furnishing breeding material, all make the basis of human activity, Earth's past, present and especially future. The minimum tillage soil systems - paraplow, chisel or rotary grape - are polyvalent alternatives for basic preparation, germination bed preparation and sowing, for fields and crops with moderate loose requirements being optimized technologies for: soil natural fertility activation and rationalization, reduction of erosion, increasing the accumulation capacity for water and realization of sowing in the optimal period. By continuously applying for 10 years the minimum tillage system in a crop rotation: corn - soy-bean - wheat - potato / rape, an improvement in physical, hydro-physical and biological properties of soil was observed, together with the rebuilt of structure and increase of water permeability of soil. The minimum tillage systems ensure an adequate aerial-hydrical regime for the biological activity intensity and for the nutrients solubility equilibrium. The vegetal material remaining at the soil surface or superficially incorporated has its contribution to intensifying the biological activity, being an important resource of organic matter. The minimum tillage systems rebuild the soil structure, improving the global drainage of soil which allows a rapid infiltration of water in soil. The result is a more productive soil, better protected against wind and water erosion and needing less 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.

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

2009-04-01

143

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

NASA Astrophysics Data System (ADS)

The energetic function of the soil expressed through the potential energy accumulated through humus, the biogeochemical function (the circuit of the nutrient elements) are significantly influenced by its hydrophysical function and especially by the state of the bedding- consolidation, soil capacity of retaining an optimal quantity of water, and then its gradual disponibility for plant consumption. The understanding of soil functions and management including nutrient production, stocking, filtering and transforming minerals, water , organic matter, gas circuit and furnishing breeding material, all make the basis of human activity, Earth's past, present and especially future. The minimum tillage soil systems - paraplow, chisel or rotary grape - are polyvalent alternatives for basic preparation, germination bed preparation and sowing, for fields and crops with moderate loose requirements being optimized technologies for: soil natural fertility activation and rationalization, reduction of erosion, increasing the accumulation capacity for water and realization of sowing in the optimal period. By continuously applying for 10 years the minimum tillage system in a crop rotation: corn - soy-bean - wheat - potato / rape, an improvement in physical, hydro-physical and biological properties of soil was observed, together with the rebuilt of structure and increase of water permeability of soil. The minimum tillage systems ensure an adequate aerial-hydrical regime for the biological activity intensity and for the nutrients solubility equilibrium. The vegetal material remaining at the soil surface or superficially incorporated has its contribution to intensifying the biological activity, being an important resource of organic matter. The minimum tillage systems rebuild the soil structure, improving the global drainage of soil which allows a rapid infiltration of water in soil. The result is a more productive soil, better protected against wind and water erosion and needing less 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.

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

2009-04-01

144

Cropping systems and control of soil erosion in a Mediterranean environment  

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

145

Robotic weld overlay coatings for erosion control. Quarterly progress report, October 1993--December 1993  

SciTech Connect

Research is being conducted to develop criteria for selecting weld overlay coatings for erosion mitigation in Circulated Fluidized Beds. Twelve weld overlay alloys were deposited on 1018 steel substrates using plasma arc welding. Ten samples from each coating were prepared for erosion testing. All selected coatings were erosion tested at 400C and their erosion resistance and microstructure evaluated. Steady state erosion rates were similar for several weld overlay coatings (Ultimet, Inconel-625, Iron-Aluminide, 316L SS, and High Chromium Cast Iron) and were considerably lower than the remaining coating evaluated. These coatings had different base (Co, Fe, Ni-base). No correlations were found between room temperature microhardness of the weld overlay coatings and their erosion resistance at elevated temperature, although this criteria is often thought to be an indicator of erosion resistance. It was suggested that the coatings that showed similar erosion rates may have similar mechanical properties such as fracture strength, toughness and work hardening rates at this temperature. During the past quarter, Iron-Aluminide, Inconel-625, and 316L SS coatings were selected for more detailed investigations based upon the preliminary erosion test results. Microhardness tests were performed on eroded samples to determine the size of the work hardened zone and change in coatings hardness due to erosion. The work hardened zone was to correlated with erosion resistance of the coatings. Additional Iron-Aluminide, Inconel-625, and 316L SS coatings were deposited on 1018 steel substrates.

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

1994-01-20

146

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

SciTech Connect

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.

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

1995-10-15

147

Poster Session--Effectiveness of Regreen Seeding for Erosion Control--Beyers USDA Forest Service Gen. Tech. Rep. PSW-GTR-189. 2008.330  

E-print Network

Poster Session--Effectiveness of Regreen Seeding for Erosion Control--Beyers USDA Forest Service Gen. Tech. Rep. PSW-GTR-189. 2008.330 Growth of Regreen, Seeded for Erosion Control, in the Manter controlled on September 6 after burning 32,074 ha (79,244 ac) of National Forest System, Bureau of Land

Standiford, Richard B.

148

UMTRA Project document control system manual  

SciTech Connect

This manual defines the Project Document Control System (PDCS) operated by the US DOE Uranium Mill tailings Remedial Action (UMTRA) project Office. The purpose of the PDCS is to provide an active and continuing program for acquiring, controlling, retaining, retrieving, retiring and disposing of all UMTRA Project documents. The PDCS also provides guidance and coordination in transferring documents by various UMTRA Projection document control centers to a central location.

Not Available

1994-09-01

149

Combined Wind and Water Erosion Modeling  

Technology Transfer Automated Retrieval System (TEKTRAN)

Current soil erosion prediction technologies in the United States for water and wind erosion are vastly different. An effort is underway to create a combined process-based water and wind erosion model, based upon the technologies in the USDA Water Erosion Prediction Project (WEPP) and Wind Erosion P...

150

Short-term soil moisture response to low-tech erosion control structures in a semi arid rangeland  

Technology Transfer Automated Retrieval System (TEKTRAN)

Although rock check dams have been used for centuries to control erosion and support subsistence agriculture on western US rangelands, there is a lack of data for quantifying their impact on soil moisture distribution. The purpose of this study was to measure and document soil moisture in associatio...

151

Biodiversity in riverbank techniques for erosion control: assessment of animal and plant species diversity along a natural gradient.  

E-print Network

: assessment of animal and plant species diversity along a naturality gradient. 7th SER European Conference and ecological succession processes. We compared plant species diversity and animal taxonomic diversity aboveBiodiversity in riverbank techniques for erosion control: assessment of animal and plant species

Paris-Sud XI, Université de

152

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)

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.

Herman, Daniel A.

2010-01-01

153

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

NASA Astrophysics Data System (ADS)

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.

Elbanna, Amany

154

Soil conservation policy measures to control wind erosion in northwestern Europe  

Microsoft Academic Search

Wind erosion is not as significant or a widespread problem in Europe as in dryer parts of the world, but it can cause major damage in small areas. The hazard is greatest in the lowlands of northwestern Europe with more than 3 million ha at high-potential wind erosion risk. Crop damage and off-site damage have prompted farmers and policymakers to

Michel Riksen; Floor Brouwer; Jan de Graaff

2003-01-01

155

WIND EROSION RESEARCH AND CONTROL IN CHINA: PAST, PRESENT AND FUTURE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Wind erosion is one of most important processes associated with land degradation and desertification in China, particularly in the arid and semiarid regions of the country. Documentation of wind erosion and its negative impacts in China dates back over 2000 years. The total land area that experien...

156

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

SciTech Connect

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).

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

1993-03-03

157

The control mechanisms of erosion and weathering at basin scale from cosmogenic nuclides in river sediment  

NASA Astrophysics Data System (ADS)

The study of a sample of river sediment enables the determination of spatially averaged denudation rates that provide an exceptional perspective on erosion and weathering processes that have taken place within a landscape. These measurements are done with in-situ-produced cosmogenic nuclides (e.g., 10Be, 26Al), mostly in quartz from alluvial sediment. Cosmogenic nuclides are produced when secondary cosmic rays interact with the very uppermost layer of the Earth's surface. They are produced within a characteristic depth scale of about 1 m, which means that the measured concentrations record an integrated denudation history while material passed through this depth interval. Depending on the denudation rate the resulting integration time scales are 10 3 to 10 5 years, and one obtains a robust long-term estimate of natural denudation that is relatively insensitive to short-term changes. The last 10 years have seen significant research activity using these methods, and an array of fascinating tectono-geomorphologic and geochemical insights are emerging. Amongst these is the ability to identify the physical and chemical processes with which a landscape responds to tectonic activity or climate change. A compilation of world-wide denudation rates in non-glaciated areas, that however, does not yet include some of the world's most active mountain belts, has resulted in the following findings, some of which have been unexpected: (1) No obvious relationship between precipitation or mean annual temperature and total denudation is apparent. (2) Topographic relief alone does not result in high rates of denudation. (3) Denudation rates are high in areas of landscape rejuvenation; that is triggered and controlled by tectonic activity (faulting, escarpment formation and retreat, rifting, surface uplift). (4) Rates of weathering (using a combination of cosmogenic nuclides and zirconium-normalised cation loss balances) co-vary primarily with physical erosion rates and much less with temperature or precipitation. (5) In some areas of high land use short-term rates (from river load gauging) exceed those from cosmogenic nuclides by several orders of magnitude, which serve to highlight the severity of geomorphic change caused by human action. In the future, the control mechanisms over denudation will be determined on all spatial scales, ranging from the single soil section to entire river basins. The same analysis can be done back through time on well-dated terraces, lake records, and marine sediment cores, which is possible with 10Be for the past 1-2 My. The rates obtained will be used to develop a quantitative understanding of tectonic, geomorphologic, and geochemical landscape processes, which in turn is a prerequisite to design and calibrate models of the response of landscapes to tectonic, climate, and anthropogenic forcing.

von Blanckenburg, Friedhelm

2006-02-01

158

The control mechanisms of erosion and weathering at basin scale from cosmogenic nuclides in river sediment  

NASA Astrophysics Data System (ADS)

The study of a sample of river sediment enables the determination of spatially averaged denudation rates that provide an exceptional perspective on erosion and weathering processes that have taken place within a landscape. These measurements are done with in-situ produced cosmogenic nuclides (e.g. 10Be, 26Al), mostly in quartz from alluvial sediment. Cosmogenic nuclides are produced when secondary cosmic rays interact with the very uppermost layer of the Earth's surface. They are produced within a characteristic depth scale of about 1 m, which means that the measured concentrations record an integrated denudation history while material passed through this depth interval. Depending on the denudation rate the resulting integration time scales are 10 3 to 10 5 years, and one obtains a robust long-term estimate of natural denudation that is relatively insensitive to short-term changes. The last 10 years have seen significant research activity using these methods, and an array of fascinating tectono-geomorphologic and geochemical insights are emerging. Amongst these is the ability to identify the physical and chemical processes with which a landscape responds to tectonic activity or climate change. A compilation of world-wide denudation rates in non-glaciated areas, that however, does not yet include some of the world's most active mountain belts, has resulted in the following findings, some of which have been unexpected: (1) No obvious relationship between precipitation or mean annual temperature and total denudation is apparent. (2) Topographic relief alone does not result in high rates of denudation. (3) Denudation rates are high in areas of landscape rejuvenation; that is triggered and controlled by tectonic activity (faulting, escarpment formation and retreat, rifting, surface uplift). (4) Rates of weathering (using a combination of cosmogenic nuclides and zirconium-normalised cation loss balances) co-vary primarily with physical erosion rates and much less with temperature or precipitation. (5) In some areas of high land use short-term rates (from river load gauging) exceed those from cosmogenic nuclides by several orders of magnitude, which serves to highlight the severity of geomorphic change caused by human action. In the future, the control mechanisms over denudation will be determined on all spatial scales, ranging from the single soil section to entire river basins. The same analysis can be done back through time on well-dated terraces, lake records, and marine sediment cores, which is possible with 10Be for the past 1-2 My. The rates obtained will be used to develop a quantitative understanding of tectonic, geomorphologic, and geochemical landscape processes, which in turn is a prerequisite to design and calibrate models of the response of landscapes to tectonic, climate, and anthropogenic forcing.

von Blanckenburg, Friedhelm

2005-09-01

159

Reconciling water harvesting and soil erosion control by thoughtful implementation of SWC measures  

NASA Astrophysics Data System (ADS)

Soil and water conservation (SWC) structures are largely present in Southeast Spain. Traditionally, SWC structures such as step terraces and earthen check dams were implemented in agricultural fields. They are usually found in semi-arid traditional rainfed agricultural systems that heavily rely on SWC structures to supplement the sparse rainfall. The on-site SWC measures favor water infiltration and reduce water runoff and soil erosion. In the river system (off site), large concrete/gabion check dams have been constructed since the 70's. The analysis of orthophotographs and field survey observations indicate a severe decay of on-site SWC structures in the agricultural area. This has been observed for the Cárcavo catchment (Murcia). The density of step terraces and check dams decreased by 25% between 1956 and 2005. Changes in the agricultural area can be summarized as: (i) rapid expansion of rainfed crops in marginal areas and (ii) mechanization of agriculture associated with frequent tillage operations. It became evident that the high density of SWC structures has now become a nuisance in rainfed orchards that are maintained by regular shallow tillage. We constrained the effects of SWC structures on hydrological connectivity by assessing their functioning during a heavy storm (return period 8.2 yrs in 2006). The percentage of cropland draining directly on the river system without interference of a check dam has increased from 9% in 1956 to 31% in 2005 and 40 % after the storm in November 2006. While there is a strong decrease of traditional SWC structures, several hundred large check dams have been constructed during the last decades in ephemeral streams (Almeria). 36 of them have been investigated in selected Sierras. The volume of sediment retained was found low (mean: 1.4 t ha-1 yr-1). 67% of the variability has been explained by topographical, land use and agricultural activities. After a field survey in 2009, a large majority of check dams located in non-agricultural catchments have been found only partially filled with sediments. Extensive reforestation programs, recovery of natural vegetation (dense matorral) and abandonment of agricultural fields in the Sierras led to a strong reduction of the sediment transport towards the river system. Although the effect of the check dams on the transport of sediment has not been important, the check dams have played a major role in flood control in the area. Our data indicate that thoughtful design of SWC schemes is necessary to reconcile water harvesting, erosion mitigation and flood control. Currently, the erosion hotspots are clearly localized in the agricultural fields, and not in the marginal lands in the Sierras. The combination of on-site and off-site SWC measures in the agricultural areas is highly efficient to reduce fluxes of sediment and surface water.

Bellin, N.; Vanacker, V.; van Wesemael, B.

2012-04-01

160

Identifying Erosion  

NSDL National Science Digital Library

In this environmental science activity (page 3 of the PDF), leaners will identify and explain the causes of erosion. They will observe the effects of erosion on the surrounding area and further explore examples of erosion online. An extension activity allows learners to make a hands-on model of soil erosion. Though this was created as a pre-visit activity for a workshop about water flow and erosion, it makes a great stand-alone activity as well!

COSI

2009-01-01

161

WEPPCAT: An Online tool for assessing and managing the potential impacts of climate change on sediment loading to streams using the Water Erosion Prediction Project (WEPP) Model  

EPA Science Inventory

WEPPCAT is an on-line tool that provides a flexible capability for creating user-determined climate change scenarios for assessing the potential impacts of climate change on sediment loading to streams using the USDA?s Water Erosion Prediction Project (WEPP) Model. In combination...

162

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...

163

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

NASA Astrophysics Data System (ADS)

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, thin soils, large areas of steep exposed bedrock, and sparser vegetation allow greater runoff and sediment in the absence of fire, making for a lesser relative importance of fire in erosion. The lack of exposed and dated deposits older than 5000 cal yr BP, even where fan feeder channels were incised to bedrock in debris-flow and flood events after the 2002 Lakes Fire, indicates that most stored alluvium was scoured from these channels in the middle Holocene, possibly from more severe fires and postfire erosion. It also suggests that erosional response after the Lakes Fire was at least locally greater than at any time in the last 5000 yr, possibly from the combined influence of fire suppression and recent warming and severe drought. However, expansion of this small study area would allow a clearer view of fire-climate-erosional linkages in the Jemez Mountains, and the degree to which modern climatic warming and anthropogenic impacts have heightened severe fire activity.

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

2013-12-01

164

Use of hold-gro erosion control fabric in the establishment of plant species on coal mine soil  

Microsoft Academic Search

Experiments were conducted on the Black Mesa Coal Mine, Kayenta, Arizona in 1977 and 1978 to study the effectiveness of Hold-Gro\\u000a Erosion Control Fabric (a product from the Gulf States Paper Corporation, Tuscaloosa, Alabama) in the establishment of plants\\u000a on coal mine soil following the surface mining of coal. Four plant species were planted: (1) spring barley (Horduem vulgare L.),

A. D. Day; K. L. Ludeke

1986-01-01

165

Late Quaternary climatic control on erosion and weathering in the eastern Tibetan Plateau and the Mekong Basin  

Microsoft Academic Search

High-resolution siliciclastic grain size and bulk mineralogy combined with clay mineralogy, rubidium, strontium, and neodymium isotopes of Core MD01-2393 collected off the Mekong River estuary in the southwestern South China Sea reveals a monsoon-controlled chemical weathering and physical erosion history during the last 190,000 yr in the eastern Tibetan Plateau and the Mekong Basin. The ranges of isotopic composition are

Zhifei Liu; Christophe Colin; Alain Trentesaux; Giuseppe Siani; Norbert Frank; Dominique Blamart; Segueni Farid

2005-01-01

166

Reducing Erosion and Runoff  

NSDL National Science Digital Library

Reducing Erosion and Runoff, from the Virginia Cooperative Extension, describes what erosion and runoff are, methods of control, including the use of plants and groundcover selection. The site also describes how to handle steep slopes and some steps for building and protecting soil. This information can also be downloaded as a pdf.

167

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

NASA Astrophysics Data System (ADS)

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, this metric is not applicable for all urbanized watersheds due to the discrepancy between the field and calculated unit critical discharges. Standards developed from urbanized reference streams could possibly better represent SCMs in urbanized watersheds. All three sub-catchments failed to meet the erosional standards demonstrating the ability of the standards to predict unstable geomorphic processes in streams. The addition of a detention SCM (wet pond), in the urbanized sub-catchment extended the duration of erosive flows from 37 to 87 h/ha/yr, but reduced the estimated volume of eroded bedload from 1.81 to 0.99 m 3/m/ha/yr when compared to uncontrolled urbanization (no wet pond). Alterations to the design of the wet pond, increased volume size and change in orifice diameter, were explored to see if erosional standards could be better met. This study demonstrated the effect of current SCM design standards on stream stability and why geomorphic processes of stream channels should be incorporated in SCM design standards.

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

2011-12-01

168

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

SciTech Connect

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.

Waugh, W.J.; Link, S.O. (Pacific Northwest Lab., Richland, WA (USA))

1988-07-01

169

Micro-Management of Lighting Controls Projects  

E-print Network

A common lighting project is to evaluate a block of rooms for savings and payback from the use of photocells or occupancy sensors. The designer counts the fixtures to be controlled, calculates the watts used and then the expected savings...

Clark, W. H.

1994-01-01

170

The Kenya railways wagon control project  

Microsoft Academic Search

As long ago as 1967 Kenya Railways decided to embark on a long term project to design and implement a computer?based system for control of its stock of some 10,000 goods wagons. Large financial savings were expected to result from the increased operational efficiency that would be achieved. The first phase of the project, providing a continuous full record of

N. J. Makhulo

1987-01-01

171

Version Control in Project-Based Learning  

ERIC Educational Resources Information Center

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…

Milentijevic, Ivan; Ciric, Vladimir; Vojinovic, Oliver

2008-01-01

172

WATER EROSION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Water erosion is caused by the detachment and transport of soil by runoff, melting snow or ice, and irrigation. Excessive erosion could threaten the production of agricultural and forest products. Erosion may also impact water conveyance and storage structures, and contribute to pollution from land ...

173

Effects of various sport drink modifications on dental caries and erosion in rats with controlled eating and drinking pattern.  

PubMed

A sport drink mixture, pH 3.2, containing 6% sucrose, was given to Osborne-Mendel rats, either as such or supplemented with 15 ppm fluoride, 38.5 ppm magnesium or both. Distilled water was given to the control groups. The rats were fed either a slightly cariogenic, powdered food containing 15% sucrose, or commercial pellets. Food and drink were available ad libitum for 6 weeks. A feeding machine was used to facilitate control of eating and drinking pattern. Daily intake of powdered, sugar-containing food was significantly smaller than that of pellets and, on the other hand, sport drink was consumed significantly more than distilled water. However, an appropriate energy balance was achieved with all of the dietary combinations, and no significant differences in weight gains were found. Sport drink did not significantly promote caries but induced marked erosion on the lingual surfaces of the lower molar teeth. Addition of fluoride to the sport drink significantly reduced caries (caused by powdered food) and had preventive effect on erosion, while addition of magnesium had no clear effect on either caries or erosion. No significant intergroup differences were found in eating or drinking patterns due to fluoride or magnesium additions. PMID:2734284

Sorvari, R

1989-01-01

174

Evaluation of compost/mulch as highway embankment erosion control in Louisiana at the plot-scale  

NASA Astrophysics Data System (ADS)

SummaryTotal suspended solids (TSS) and associated turbidity in runoff water are considered the most problematic nonpoint source pollutant of Louisiana surface waters. With high precipitation in Louisiana, attention should be given to controlling highway right-of-way erosion. The use of compost/mulch for erosion control enhances soil conservation and substantially reduces erosion. The main objective of this study was to assess the effect of compost/mulch placement on runoff water quality on roadsides. Our hypothesis was that the use of compost/mulch would significantly reduce TSS and turbidity in runoff from highway right-of-ways in Louisiana. Two locations constituting four sites and eight individual plots were chosen; one in an active highway construction area and another in an established area plagued by continual rill and sheet erosion. Thicknesses of compost/mulch (5 and 10 cm), slope inclination (10-34%), and tillage practices (till vs. no-till) were evaluated. Runoff, triggered by storm water events, was collected using ISCO auto-samplers from June 2010 to August 2011 and the samples were analyzed for TSS, turbidity, biochemical oxygen demand, electrical conductivity, and pH. The results of factor analysis showed that the compost/mulch thickness was the most influential variable affecting water quality. Two samples t-test results indicated that TSS and turbidity were significantly different across all comparative variables; construction activities, compost/mulch applications, and tillage practices. The results confirmed the effectiveness of compost/mulch cover as a successful best management practice. Specifically decreases in TSS of 70% and 74% were achieved for the 5 cm and 10 cm compost/mulch application when compared to no compost/mulch, respectively. Light tillage application increased TSS as much as 67%. Therefore, light tillage is not recommended since it decreased the effectiveness of compost/mulch in reducing runoff and sediment losses.

Bakr, Noura; Weindorf, David C.; Zhu, Yuanda; Arceneaux, Allen E.; Selim, H. M.

2012-10-01

175

Alginate controls heartburn in patients with erosive and nonerosive reflux disease  

PubMed Central

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 events (i.e., nausea and bloating). CONCLUSION: Our findings demonstrate that Faringel is well-tolerated and effective in reducing heartburn by modifying esophageal acid exposure time, number of acid refluxes and their proximal migration. PMID:22969201

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

2012-01-01

176

Erosion Effects  

NASA Technical Reports Server (NTRS)

[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.

2003-01-01

177

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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...

178

Evaluating Material Properties to Optimize Wood Strands for Wind Erosion Control  

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 from eroding land poses a risk to both environmental quality and human health. Since the advent of the Clean Air Act in 1971, ambient air quality standards have been ...

179

Contour Ripping and Composted Dairy Manure for Erosion Control on Fort Hood Military Installation, Texas  

E-print Network

dairy manure may increase vegetation, while contour ripping may decrease discharge, both of which will lead to a decrease in erosion. Three small 0.30 ha watersheds were established on Fort Hood in January 2005. Each watershed had 0.46 m berms installed...

Prcin, Lisa J.

2010-07-14

180

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...

181

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)

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 vegetation properties are studied by setting up comparative test plots at a field study site located at a headrace channel of a hydroelectric power plant. Different vegetational parameters such as basal coverage, species richness, species composition, abundance/dominance values by using a refined Braun-Blanquet cover estimation scale were collected as well as local environmental properties. Results during the first vegetation period show distinct effects of geotextiles especially on overall vegetation coverage and grasses-herbs-ratio. Geotextile supported plots show 20% higher overall coverage but lower amount of herbs after three months of vegetation growth compared to control plots without installation of auxiliary materials. Furthermore coir blankets reveal higher penetration resistance for seed leaves of herbal plants compared to coir nettings. Hence technical erosion protection products, biological components and it's combination have to be closely coordinated in order to achieve specified revegetation objectives and meet long-term functionality.

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

2012-04-01

182

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

NASA Astrophysics Data System (ADS)

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.

Clift, Peter

2013-04-01

183

77 FR 21722 - Gore Creek Restoration Project; Intent To Prepare an Environmental Impact Statement  

Federal Register 2010, 2011, 2012, 2013, 2014

...Pass area to improve watershed health and reduce potential erosion issues. Timber harvesting that took place outside of previously...ripping, seeding, slash, re- contouring, scarification, and erosion control. Watershed improvement projects are proposed on...

2012-04-11

184

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

PubMed

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. PMID:20073341

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

185

Aspect and soil water repellency controlling water erosion in dry Mediterranean environment  

NASA Astrophysics Data System (ADS)

Soil hydrological response in Mediterranean areas is usually highly complex due to the strong spatial variability. This fact is amplified by the marked seasonality of precipitations, which provokes dramatic changes in vegetation cover and soil properties, such as soil water content or soil water repellency (SWR). The goal of this study is to shed light on the relations between SWR, aspect and vegetation, determining the soil hydrological and erosive response throughout the rainy period in different microenvironments. Erosion plots were set up in the north- and the south-facing hillslope, in shrub-covered as well in inter-shrub patches, and rainfall, runoff, sediments and SWR were monitored. Soils showed water repellency at the end of the dry season in both microenvironments of the north-facing hillslope but only in covered patches of the south-facing one. With the onset of the wet season, SWR disappeared and runoff coefficients decrease dramatically in the north-facing hillslope, revealing the importance of SWR in the hydrological response. In the south-facing hillslope seasonal changes were less important and the hydrological behaviour was mainly modulated by the vegetation pattern. Sediment losses were also affected by SWR and it decreased in the wet season when repellency disappeared. Regarding precipitation, the main factor determining the hydrological and erosive response was rainfall intensity, regardless of the rainfall depth of the event.

Gabarron-Galeote, Miguel A.; Martínez-Murillo, Juan F.; Quesada, Miguel A.; Ruiz-Sinoga, José D.

2014-05-01

186

Radial Erosion  

NASA Technical Reports Server (NTRS)

[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.

2005-01-01

187

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

SciTech Connect

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.

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

2012-06-29

188

Commercial versus synthesized polymers for soil erosion control and growth of Chinese cabbage.  

PubMed

Soil erosion leads to environmental degradation and reduces soil productivity. The use of anionic polyacrylamide (PAM) and synthesized biopolymer (BP) using lignin, corn starch, acrylamide, and acrylic acid were tested to evaluate soil erosion, water quality, and growth of Chinese cabbage (Brassica campestris L.). Each treatment of PAM and BP was applied at 200 kg ha(-1) to loamy sand soil and subjected to a slope of 36% with a 20 mm h(-1) simulated rainfall. Application of BP decreased soil pH compared to the untreated check (CK); however, the soil pH was not altered with PAM. The decrease in pH might most likely be due to availability of anionic sites to be protonated on soils having pH >6 and soil buffering capacity. Both PAM and BP applications may not induce eutrophication with stable levels of total contents of N and P. With PAM and BP, the average values of suspended soil (SS) and turbidity were reduced by up to 96.0 and 99.9%, respectively, compared to CK. Reduction of SS can be attributed to increasing soil stability and shear strength by clay flocculation. There was no toxicity effects resulting from germination tests and the dry weight was increased by 17.7% (vs. CK) when PAM and BP were applied. These results are attributed to increases in water retention and plant-available water. The use of polymeric soil amendments is an environmentally friendly way to mitigate soil erosion and nonpoint source pollution. PMID:25674399

Lee, Sang Soo; Chang, Scott X; Chang, Yoon-Young; Ok, Yong Sik

2013-01-01

189

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...

190

Erosion can be a problem in many airfield areas. Erosion and sedimentation affect  

E-print Network

Erosion can be a problem in many airfield areas. Erosion and sedimentation affect local water. Effective erosion control requires an integrated approach that takes into account government regu- lations and erosion control methods (see examples in Figs. 1 and 2). This article outlines several considerations

Minnesota, University of

191

ELKINS MINE DRAINAGE POLLUTION CONTROL DEMONSTRATION PROJECT  

EPA Science Inventory

In 1964 several federal agencies in cooperation with the State of West Virginia initiated a project to demonstrate methods to control the pollution from abandoned underground and surface mines in the Roaring Creek-Grassy Run Watersheds near Elkins, West Virginia. The Roaring Cree...

192

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

SciTech Connect

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 scale. Soil samples with varying moisture (W/W %) content and soil samples treated with fixatives, selected from a wide range of commercially available products, were exposed to a wind speeds ranging from 10 - 30 miles per hour (MPH). During these experiments, amount of soil displaced due to the wind forces, the amount of airborne particulates generated, and the moisture loss were measured to better understand the performance of selected fixatives and soil moisture. Results obtained during the study showed that there is a significant reduction in wind erosion and airborne particles generation by increasing the soil moisture for the velocities tested. Similar trend was observed when the soil samples treated with fixatives were exposed to the same range of velocities (10 - 30 MPH). (authors)

Lagos, L.E.; Gudavalli, R.K. [Applied Research Center, Florida International Univ., Miami, FL (United States)

2008-07-01

193

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

USGS Publications Warehouse

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.

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

1981-01-01

194

Dental Erosion in Industry  

PubMed Central

Five hundred and fifty-five acid workers were examined between March 1962 and October 1964. One hundred and seventy-six (31·7%) were affected by industrial dental erosion at the first examinations. In 33 cases (6·0%) the dentine was affected. During the period of the survey, 66 (20·4%) of 324 workers examined more than once showed evidence that erosion was progressing. The prevalence and incidence of erosion were highest among battery formation workers, lower among picklers, and least among other processes covered by the survey. The age of workers did not appear to influence their susceptibility to erosion. The habit of working with the lips slightly parted had little effect. Erosion superimposed upon attrition predisposed to more severe loss of tooth structure than either operating alone. Little inconvenience or functional disability was suffered by acid workers due to erosion. Twenty-seven (23·7%) of 114 erosions were considered to be disfiguring. Regular dental treatment was sought less by acid workers than by controls, and the oral hygiene of the latter was superior. There was no evidence to show any difference between caries experience among acid workers and controls. Calculus and periodontal disease were more prevalent among acid workers than among controls, but it was not possible to attribute this to the working environment. Black staining in iron picklers was considered to be due to the working environment. The use of closed acid containers or lip extraction on open acid vats prevented significant atmospheric contamination and diminished the prevalence of erosion. The use of wall fans and detergent foaming agents was helpful. Images PMID:5723349

Cate, H. J. Ten Bruggen

1968-01-01

195

Distinguishing between tectonic and lithologic controls on bedrock channel longitudinal profiles using cosmogenic 10Be erosion rates and channel steepness index  

NASA Astrophysics Data System (ADS)

Models of rivers undergoing steady tectonic and climatic forcing predict smooth, concave-up longitudinal profiles. Deviations from this predicted form in purely fluvial channels (e.g. knickpoints) are commonly cited as evidence for disequilibrium conditions, and often attributed to either non-uniform or unsteady rock uplift associated with either active or ancient structures. However, knickpoints are not always formed in response to uplift; they can also be the result of spatial variations in bedrock erodibility, with steeper channels occurring in more resistant rock. Recently, normalized channel steepness index (ksn), derived from digital elevation data, has been used to identify active structures and to infer relative differences in rock uplift rates, providing a powerful tool for studying landscape evolution and active tectonics. However, the distinction between channel morphologies controlled by tectonic forcing and those controlled by changes in substrate erodibility are difficult to make from digital elevation data alone. We will show how cosmogenic nuclide-based erosion rates can be used in tandem with stream profiles to distinguish tectonic from lithologic control on bedrock channel morphology. We first present four idealized predictions of bedrock channel characteristics (longitudinal profiles, slope-area relationships, ksn values, and erosion rates) that can be interpreted as the result of either tectonic or lithologic control. In cases where channel morphology is controlled by rock uplift rate, ksn and erosion rate should be positively correlated. Alternatively, where the channel profile is controlled by differences in erodibility, ksn and erosion rate should be inversely-correlated (e.g. hard rocks should have steeper channels but slower erosion rates than softer rocks). These predictions are then compared to the spatial patterns of ksn and cosmogenic 10Be erosion rates from four distinct landscapes in Italy: the Romagna Apennines, which exposes a uniform lithology and where rock uplift rates are low; the Peloritani Mountains, which exposes a uniform lithology and where rock uplift rates are non-uniform; the Sila Massif, which exposes a uniform lithology but has experienced unsteady rock uplift rates; and the Emilia Apennines, where rocks are more resistant near the range crest than at the range front but rock uplift rates are uniform. In each case, the along-channel distribution of both ksn and erosion rate are consistent with our model predictions of channel profile evolution driven by differences in either tectonic forcing or lithologic resistance to erosion. While we do not suggest that cosmogenic nuclide methods can be used as a substitute for field mapping, our analysis indicates that they can be applied to objectively distinguish between tectonic and lithologic controls on bedrock channel longitudinal profiles.

Cyr, A. J.; Granger, D. E.; Olivetti, V.; Molin, P.

2009-12-01

196

Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion (FBC) system. Technical progress report No. 3, [April 1, 1993--June 30, 1993  

SciTech Connect

This technical report summarizes the research work performed and progress achieved during the period of during the period of April 1, 1993 to June 30, 1993. The erosion test was conducted in the bench-scale FBC model along with the preparation of the test particles/tube specimens. The effect of the tube-to-distributor (T-to-D) clearance was discussed on the tube specific weight loss for low, medium, and high superficial velocities. Electrostatic impact probes for measuring the particle-surface collision frequency were designed to verify the some of the measurement and to identify the primary erosion points. The erosion models were briefly to understand the phenomena of in-bed erosion. The project has been progressing well. Instrumentation for the erosion-measuring will be continued: to measure the tube weight loss under different operating conditions. Development of the electrostatic probes will be continued and implemented for measuring the particle-tube collision frequency in the bench-scale FBC model.

Lee, Seong W.

1993-07-01

197

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

NASA Technical Reports Server (NTRS)

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.

Deadmore, D. L.

1984-01-01

198

Geomorphic considerations for erosion prediction  

Microsoft Academic Search

Current soil-erosion prediction technology addresses processes of rainsplash, overland-flow sediment transport, and rill\\u000a erosion in small watersheds. The effects of factors determining sediment yield from larger-scale drainage basins, in which\\u000a sediment movement is controlled by the combined small-scale processes and a complex set of channel and other basin-scale sediment-delivery\\u000a processes, such as soil creep, bioturbation, and accelerated erosion due to

W. R. Osterkamp; T. J. Toy

1997-01-01

199

Optimal Land Use Management for Soil Erosion Control by Using an Interval-Parameter Fuzzy Two-Stage Stochastic Programming Approach  

NASA Astrophysics Data System (ADS)

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] × 109 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.

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

2013-09-01

200

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

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

201

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Revegetation, and Maintenance Plan; Wetland and Waterbody Construction and Mitigation...Revegetation, and Maintenance Plan (Plan) and Wetland and Waterbody Construction and Mitigation...duration of project-related disturbance on wetlands and waterbodies. Attached to this...

2012-08-07

202

Environmental Impact Statement Truckee Meadows Flood Control Project  

E-print Network

DRAFT Environmental Impact Statement for the Truckee Meadows Flood Control Project Nevada General 2013 #12;#12;DRAFT Environmental Impact Statement for the Truckee Meadows Flood Control Project Nevada

US Army Corps of Engineers

203

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 ...

204

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

USGS Publications Warehouse

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 and most of the sediment from the beachface and dunes was deposited within the upper-shoreface. It is argued that this sediment is returned to the beachface through nearshore bar migration following the storm and that the areas with larger foredunes and backbarrier dunes have smaller rates of historical shoreline erosion compared to areas with smaller dunes and greater transfer of sediment to the washover terrace. Since the recovery of the dunes will vary depending on the availability of sediment from the washover and beachface, it is further argued that the alongshore pattern of dune morphology and the response of the island to the next extreme storm is forced by the transverse ridges and island width through alongshore variations in storm surge and overwash gradients respectively. These findings may be particularly important for coastal managers involved in the repair and rebuilding of coastal infrastructure that was damaged or destroyed during Hurricane Ivan. ?? 2008 Elsevier B.V. All rights reserved.

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

2008-01-01

205

Project W-058 monitor and control system logic  

SciTech Connect

This supporting document contains the printout of the control logic for the Project W-058 Monitor and Control System, as developed by Programmable Control Services, Inc. The logic is arranged in five appendices, one for each programmable logic controller console.

ROBERTS, J.B.

1999-05-12

206

A Statistical Project Control Tool for Engineering Managers  

NASA Technical Reports Server (NTRS)

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.

Bauch, Garland T.

2001-01-01

207

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

Microsoft Academic Search

The role of forest stand density in con- trolling soil erosion was investigated in Ehime Prefecture, Japan. The main objective was to com- pare 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 indi- cator of stand density to reflect the degree

Bam H. N. Razafindrabe; Shoji Inoue; Tsugio Ezaki; Rajib Shaw

2008-01-01

208

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

SciTech Connect

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.

Not Available

1992-07-17

209

Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion (FBC) system. Technical progress report No. 4, [July 1, 1993--September 30, 1993  

SciTech Connect

This technical report Summarizes the research work performed and progress achieved during the period of July 1, 1993 to September 30, 1993. Design and fabrication of the electrostatic impact probe were continued for measuring particle-tube collision frequency in the bench-scale FBC model. To verify the working principle of the electrostatic impact probe and to establish the reliability of probe readings, several readings were performed. The number of impact particles can be conveniently read from the frequency counter by the impact probe, which was reproducible and consistent data. The erosion measurement was conducted under different superficial fluidizing velocity in the bench-scale FBC model. Results of specific weight loss versus excess air velocity (air velocity above the minimum fluidization velocity) show the dominant effect of the fluidizing velocity on the tube erosion. The project has been progressing well. Measurement of the particle-tube collision frequency will be conducted under different tube location by the electrostatic impact probe. Instrumentation for the measurement of the in-bed tube erosion will be continued under various operating conditions. In addition to that, the relationship between the results of particle-tube collision frequency and the measurement of in-bed tube erosion will be predicted.

Lee, Seong W.

1993-11-01

210

Greenidge Multi-Pollutant Control Project  

SciTech Connect

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 CONSOL Energy Inc. as prime contractor, AES Greenidge LLC as host site owner, and Babcock Power Environmental Inc. as engineering, procurement, and construction contractor. About 44% of the funding for the project was provided by the U.S. Department of Energy, through its National Energy Technology Laboratory, and the remaining 56% was provided by AES Greenidge. Project goals included reducing high-load NO{sub x} emissions to {le} 0.10 lb/mmBtu; reducing SO{sub 2}, SO{sub 3}, HCl, and HF emissions by at least 95%; and reducing Hg emissions by at least 90% while the unit fired 2-4% sulfur eastern U.S. bituminous coal and co-fired up to 10% biomass. This report details the final results from the project. The multi-pollutant control system was constructed in 2006, with a total plant cost of $349/kW and a footprint of 0.4 acre - both substantially less than would have been required to retrofit AES Greenidge Unit 4 with a conventional SCR and wet scrubber. Start-up of the multi-pollutant control system was completed in March 2007, and the performance of the system was then evaluated over an approximately 18-month period of commercial operation. Guarantee tests conducted in March-June 2007 demonstrated attainment of all of the emission reduction goals listed above. Additional tests completed throughout the performance evaluation period showed 96% SO{sub 2} removal, 98% mercury removal (with no activated carbon injection), 95% SO{sub 3} removal, and 97% HCl removal during longer-term operation. Greater than 95% SO{sub 2} removal efficiency was observed even when the unit fired high-sulfur coals containing up to 4.8 lb SO{sub 2}/mmBtu. Particulate matter emissions were reduced by more than 98% relative to the emission rate observed prior to installation of the technology. The performance of the hybrid SNCR/SCR system was affected by problems with large particle ash, ammonia slip, and nonideal combustion characteristics, and high-load NO{sub x} emissions averaged 0.14 lb/mmBtu during long-term operation. Nevertheless, the system has reduced the unit's overall NO{sub x} emiss

Daniel Connell

2008-10-18

211

TRMM project contamination control using molecular adsorbers  

SciTech Connect

The Tropical Rainfall Measuring Mission (TRMM) is a spacecraft under development by the National Aeronautics and Space Administration (NASA) and the National Space Development Agency of Japan (NASDA) and is scheduled for launch in August 1997. The spacecraft design includes the use of numerous optical instruments and the thermal control surfaces. In addition to the inherent contamination sensitivities of the optical and thermal systems, TRMM has had the added challenge of designing systems to function at a relatively low altitude (350 km), with solar exposure. Under these conditions, high atomic oxygen densities and potentially high levels of backscattered contamination (self-contamination), as well as UV photopolymerization effects, all pose major threats to sensitive TRMM elements. In considering the various contamination control paths to follow, the TRMM project management has opted for pursuing a relatively new, but very promising technology for the TRMM spacecraft in order to lower the on-orbit contamination levels. TRMM will be incorporating Molecular Adsorbers as part of the basic spacecraft design. This paper will summarize the TRMM requirements, describe the Molecular Adsorbers being fabricated for the mission, and discuss the expected benefits of this method of on-orbit contamination control. {copyright} {ital 1996 American Institute of Physics.}

Straka, S.; Chen, P.; Thomson, S. [NASA Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States); Bettini, R.; Triolo, J.; Carosso, N. [Swales and Associates, Inc., 5050 Powder Mill Road, Beltsville, Maryland 20705 (United States)

1996-03-01

212

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

SciTech Connect

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.

Hathcock, Charles D. [Los Alamos National Laboratory

2012-08-27

213

Erosion in Rivers  

NSDL National Science Digital Library

Students learn about water erosion through an experimental process in which small-scale buildings are placed along a simulated riverbank to experience a range of flooding conditions. They learn how soil conditions are important to the stability or failure of civil engineering projects and how a river's turns and bends (curvature, sinuosity) make a difference in the likelihood of erosion. They make model buildings either with a 3D printer or with LEGO® pieces and then see how their designs and riverbank placements are impacted by slow (laminar) and fast (turbulent) water flow over the soil. Students make predictions, observations and conclusions about the stability of their model houses, and develop ideas for how to mitigate damage in civil engineering projects.

2014-09-18

214

ECONOMIC IMPACTS OF SELECTED EROSION CONTROL POLICIES: DISTRIBUTION AMONG CORN BELT STATES  

EPA Science Inventory

If states in the Corn Belt adopt varying soil loss limits as a part of a nonpoint source of water pollution control program will there be adverse economic consequences. If so, what types of impacts would be felt and would they be severe. The objective of this analysis was focused...

215

Modeling the air traffic controller's cognitive projection process  

E-print Network

Cognitive projection enables the operator of a supervisory control system, such as air traffic control, to use predicted future behavior of the system to make decisions about if and how to control the system. New procedures ...

Reynolds, Hayley J. Davison (Hayley Jaye Davison)

2006-01-01

216

Erosion and Sediment Damages and Economic Impacts of Potential 208 Controls: A Summary of Five Watershed Studies in Texas  

E-print Network

This report summarizes results of economic analyses of erosion and sedimentation in five agricultural watersheds in Texas (see fig. 1). Economic analyses of the study areas considered both the on-farm economics of soil conservation and the economic...

Taylor, C. R.; Reneau, D. R.; Harris, B. L.

217

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

PubMed

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-?m 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. PMID:23861022

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

218

The erosive wear of mild and stainless steels under controlled corrosion in alkaline slurries containing alumina particles  

Microsoft Academic Search

The erosive wear in an alkaline slurry containing alumina particles of three typical engineering materials, the mild steel BS 6323 (Fe-C), the AISI 410 stainless steel (Fe-Cr-C), and the AISI 304 stainless steel (Fe-Cr-Ni), was carried out, by means of rotating cylinder, three-electrode erosion-corrosion test, with a view to investigation into the roles of the typical elements and the mechanical

H. W. Wang; M. M. Stack

2000-01-01

219

Comparing lansoprazole and omeprazole in onset of heartburn relief: results of a randomized, controlled trial in erosive esophagitis patients  

Microsoft Academic Search

OBJECTIVE:This randomized, double-blind, multicenter study was conducted to confirm a previous finding that lansoprazole relieves heartburn faster than omeprazole in patients with erosive esophagitis.METHODS:A total of 3510 patients with erosive esophagitis and at least one episode of moderate to very severe daytime and\\/or nighttime heartburn during the 3 days immediately before the screening visit were randomized to lansoprazole 30 mg

Joel E. Richter; Peter J. Kahrilas; Stephen J. Sontag; Thomas O. G. Kovacs; Bidan Huang; Jennifer L. Pencyla

2001-01-01

220

Laboratory Projects in Developing Inexpensive Control System Experiments  

E-print Network

, along with its supporting electronics. Humidity Control: Build a scale-model room, with windowsLaboratory Projects in Developing Inexpensive Control System Experiments Kevin M. Passino Dept@ece.osu.edu At OSU we have a project that focuses on the development of inexpensive control system experiments

221

Integrated visualized time control system for repetitive construction projects  

Microsoft Academic Search

Construction control is an essential management function for successful delivery and achieving of construction projects’ goals. Considerable research efforts have been done regarding project control. However, literature suffers from a lack of visualizing the controlling process. With the growth of using visualization techniques in construction, Building Information Modeling (BIM) and Geographic Information System (GIS) have recently attained a widespread contribution

Emad Elbeltagi; Mahmoud Dawood

2011-01-01

222

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

223

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

USGS Publications Warehouse

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)

Garcia, K.T.

1988-01-01

224

The role of fine and coarse roots in shallow slope stability and soil erosion control with a focus on root system architecture: a review  

Microsoft Academic Search

The contribution of plant root systems to slope stability and soil erosion control has received a lot of attention in recent\\u000a years. The plant root system is an intricate and adaptive object, and understanding the details of soil–root interaction is\\u000a a difficult task. Although the morphology of a root system greatly influences its soil-fixing efficiency, limited architectural\\u000a work has been

Bert Reubens; Jean Poesen; Frédéric Danjon; Guy Geudens; Bart Muys

2007-01-01

225

A Precise Controllable Projection System for Projected Virtual Characters and Its Calibration   

E-print Network

In this paper we describe a system to project virtual characters that shall live with us in the same environment. In order to project the characters' visual representations onto room surfaces we use a controllable projector.

Ehnes, Jochen

2010-01-01

226

OPTIMAL CONTROL OF PROJECTS BASED ON KALMAN FILTER APPROACH FOR TRACKING & FORECASTING THE PROJECT PERFORMANCE  

E-print Network

Covariance Matrix Adaption Evolution Strategy (CMA-ES). The implementation of the developed framework is used with a hypothetical project and tested for its robustness in updating the assumed initial project dynamics model and yielding the optimal control...

Bondugula, Srikant

2010-07-14

227

Coprates Erosion  

NASA Technical Reports Server (NTRS)

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

2006-01-01

228

Control Account Manager (CAM) Responsibilities Control Account Manager (CAM) responsibilities are listed in the PPPL Project  

E-print Network

are listed in the PPPL Project Management System Description (PMSD) and PMSD Appendix E Supporting loaded tasks After project start: · Manage the daytoday work execution (addressing risk or technicalControl Account Manager (CAM) Responsibilities Control Account Manager (CAM) responsibilities

Princeton Plasma Physics Laboratory

229

An optimal projection controller for an experimental truss structure  

SciTech Connect

An Optimal Projection reduced order controller is designed and implemented on an experimental controlled structure testbed. Twenty modes of the test structure lie within the controller bandwidth. Four strain sensor signals are fed back through an eighteenth order dynamic controller into four stress actuators (not collocated with the sensors) to reduce the vibration of the structure. Five independent performance measures are simultaneously minimized with an Optimal Projection controller derived from a 58th order state space model. The controller reduces the RMS vibration response by up to 65% without saturating the actuators and without destabilizing high frequency modes. The Optimal Projection controller always performs better than a sub-optimal controller based on ordinary Linear Quadratic Gaussian theory. The homotopy algorithm used to solve the Optimal Projection synthesis equations is described, and both analytical and experimental results are presented. 26 refs., 6 figs., 5 tabs.

Peterson, L.D.

1989-01-01

230

Administrative Leadership as Projection, Social Control, and Action.  

ERIC Educational Resources Information Center

Over the past 50 years, theoretical and methodological problems have plagued the study of leadership. This paper, proposing an alternative theory, argues that leadership has three fundamental components: projection and social control, which are linked by action. Projection is the visualization of a project to be completed. Educational…

Reed, Donald B.

231

Self-Correcting HVAC Controls Project Final Report  

SciTech Connect

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.

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

2010-01-04

232

Assessing soil erosion and control factors by radiometric technique in the source region of the Yellow River, Tibetan Plateau  

NASA Astrophysics Data System (ADS)

Measurements of 137Cs concentration in soils were made in a representative catchment to quantify erosion rates and identify the main factors involved in the erosion in the source region of the Yellow River in the Tibetan Plateau. In order to estimate erosion rates in terms of the main factors affecting soil loss, samples were collected taking into account the slope and vegetation cover along six selected transects within the Dari County catchment. The reference inventory for the area was established at a stable, well-preserved, site of small thickness (value of 2324 Bq·m- 2). All the sampling sites had been eroded and 137Cs inventories varied widely in the topsoil (14.87-25.56 Bq·kg- 1). The effective soil loss values were also highly variable (11.03-28.35 t·km- 1·yr- 1) in line with the vegetation cover change. The radiometric approach was useful in quantifying soil erosion rates and examining patterns of soil movement.

Wang, Yibo; Niu, Fujun; Wu, Qingbai; Gao, Zeyong

2014-05-01

233

Soil erosion in a man-made landscape: the Mediterranean  

NASA Astrophysics Data System (ADS)

Mediterranean-type ecosystems are characterised by a seasonally contrasted distribution of precipitation, by the coincidence of the driest and hottest season in summer, by an often-mountainous terrain, and by a long history of intense human occupation, especially around the Mediterranean Sea. The history of the Mediterranean lands is the history of human impacts on the soil system, and soil erosion is the most intense and widespread impact on this land where high intensity and uneven rainfall is found. A review of the soil erosion rates measured in the Mediterranean basin will be shown. The measurements done by means of erosion pins, topographical measurements, rainfall simulators, Gerlach collectors in open or close plots, watershed/basin measurements, reservoirs siltation and historical data will be shown. A review of the soil erosion models applied in the Mediterranean will be shown. The tentative approach done until October 2011 show that the soil erosion rates on Mediterranean type ecosystems are not as high as was supposed by the pioneers in the 70's. And this is probably due to the fact that the soils are very shallow and sediments are not available after millennia of high erosion rates. This is related to the large amount of rock fragments are covering the soil, and the rock outcrops that are found in the upper slope trams and the summits. Soil erosion in the Mediterranean is seasonal due to the rainfall concentration in winter, and highly variable within years as the high intensity rainfall events control the sediment production. Natural vegetation is adapted to the Mediterranean environmental conditions, and they are efficient to control the soil losses. An example are the forest fire that increase the soil losses but this is a temporal change as after 2-4 years the soil erosion rates are similar to the pre-fire period. Agriculture lands are the source of sediments although the highest erosion rates are found in badland areas that cover a small part of the Mediterranean lands. The methods applied to measure or estimate the soil erosion should be improved to make them comparable. An agreement is necessary to decide the size of the plots, the material and equipment to be used and the future research topics. This research study is being supported by the the research project CGL2008-02879/BTE

Cerdà, A.; Ruiz Sinoga, J. D.; Cammeraat, L. H.

2012-04-01

234

Radiological evaluation of erosions  

PubMed Central

1 The most reliable method for evaluating possible remission-inducing properties in a drug is to measure how well it prevents the appearance of new erosions in serial X-rays of the hands. 2 I have reviewed the literature on the development, over the last 25 years, of a standard method for quantitatively assessing the progress of erosions radiologically. 3 The only drugs thus far shown to be genuinely remission-inducing are cyclophosphamide, high-dose penicillamine, and (most consistently over several decades) gold-thiols, all drugs with life-threatening toxicity. 4 The search for a non-steroidal drug with remission-inducing properties is crucial in our efforts to find a safe drug to control the progression of rheumatoid arthritis. PMID:3620278

O'Brien, W. M.

1986-01-01

235

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)

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.

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

2015-03-01

236

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

NASA Technical Reports Server (NTRS)

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.

Hayhurst, Kelly J. (Editor)

2008-01-01

237

Erosion of mud\\/sand mixtures  

Microsoft Academic Search

The prediction of sediment erosion is an important issue in coastal engineering projects. There are methods for predicting the erosion of cohesive sediment (mud) and non-cohesive sediment (sand), but there are presently no relationships for mixed sediments. However, natural sediments rarely consist of only mud or sand and the erosional properties of combined mud and sand sediments are required so

Helen Mitchener; Hilde Torfs

1996-01-01

238

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

SciTech Connect

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.

Arnautovic, D.; Medanic, J.

1987-12-01

239

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

NASA Technical Reports Server (NTRS)

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

Hayhurst, Kelly J. (Editor)

2008-01-01

240

DIVISION OF DRUG ABUSE CONTROL A Project Evaluation  

E-print Network

L,: . -'" -- . : NARCONON 1/1 DIVISION OF DRUG ABUSE CONTROL FA-48-72 74-007 75-009 A Project. In Relation to the Stated Objectives of the Division of Drug Abuse Control's Application .......... II ........·..··.· Appendix C - NARCONON - Division of Drug Abuse Control Contract ..·.............·..... Appendix D - Job

Touretzky, David S.

241

Controls on project proponents and environmental impact assessment effectiveness  

SciTech Connect

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.

Ortolano, L. (Stanford Univ., CA (United States))

1993-01-01

242

Analysing, quantifying and modelling soil erosion on steep hillslopes in different climatic areas using LiDAR and SFM DEMs  

NASA Astrophysics Data System (ADS)

Soil erosion is a worldwide well known problem and has therefore been subject to various scientific studies, especially on agricultural areas. However soil erosion on steep hillslopes in mountainous drainage basins can be a threat to human infrastructure as it supplies material, e.g. for debris flows to torrents. The study presented here aims to analyse, quantify and model soil erosion on (very) steep hillslopes free of vegetation in different climatic areas ranging from South Germany to Central Italy. Multitemporal digital elevation models were acquired with terrestrial laserscanning and from terrestrial and aerial structure from motion-based imagery. Analysis of erosion is mainly based on slope wash and rill erosion during summer months as well as erosion through freezing and melting processes during winter months in catchments of the Bavarian Alps. Erosional processes in the Mediterranean are mainly controlled by different precipitation regimes throughout the year. Annual erosion and accumulation rates are quantified and used for modelling purposes. First results of the presented project show, that the amount of material eroded is mainly controlled by the size of the sediment contributing area. However there are also other controlling factors, such as slope angle, slope length and vegetation cover which are investigated within this project.

Neugirg, Fabian; Haas, Florian; Kaiser, Andreas; Schmidt, Jürgen; Becht, Michael

2014-05-01

243

Estimating soil erosion and deposition under historical and projected climate and land cover change scenarios in the Temperate Prairies ecoregion of the United States  

NASA Astrophysics Data System (ADS)

Soil erosion from agricultural lands is one of the major causes of water quality deterioration in the Midwest United States. In addition, soil erosion and deposition play an important role in the lateral exchange of carbon and other elements between adjacent landscape positions. Movement of upland eroded soil into deposition areas such as water-logged environments may reduce the Soil Organic Carbon (SOC) at eroded sites and increase the SOC at deposition sites. Few studies have investigated the spatial and temporal changes of soil erosion and deposition under various land cover and climate change scenarios over large areas. In this study, we estimated soil erosion and deposition in the Temperate Prairies Ecoregion (Level II) from 1996 to 2050 using the Unit Stream Power-based Erosion Deposition (USPED) model. Driving datasets included precipitation, soil erodibility factor, topography, land cover change, and land management (e.g., tillage). We used high-resolution climate change scenarios (A1B, A2, and B1) from 2006 to 2050 from the CGCM3 climate model. Results were partially validated using tracer measurements on an agricultural landscape in Iowa. Variability in regional soil erosion between 1996 and 2050 was expected. A correlation analysis of the interannual rainfall and cover factors was applied to assess the impact of these factors on soil erosion in the region.

Young, C. J.; Liu, S.; Oeding, J.; Liu, J.; Schmidt, G.; Sohl, T. L.; Bliss, N. B.

2011-12-01

244

Projection Operator: A Step Towards Certification of Adaptive Controllers  

NASA Technical Reports Server (NTRS)

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.

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

2010-01-01

245

Soil and Sediment Erosion  

NSDL National Science Digital Library

This brief article discusses the effect of soil and sediment erosion and its significance in social and economic aspects. The methods of measuring erosion and knowledge of past erosion rates are also briefly discussed to use as a predictor of future erosion rates.

246

Erosion from low slopes  

Microsoft Academic Search

Simulated rainfall was used to generate erosion of plots on 0.1% slopes with different surface water depths. Maximum erosion rates occurred under an average surface runoff depth of about 2 mm. Little change in erosion rates occurred for depths greater than about 20 mm. These results help explain the mechanics of erosion on low slopes and suggest that manipulation of

Calvin K. Mutchler; K. C. McGregor

1983-01-01

247

Erosion control blankets, organic amendments and site variability influenced the initial plant community at a limestone quarry in the Canadian Rocky Mountains  

NASA Astrophysics Data System (ADS)

Season of seeding and soil amendment with manure mix, wood shavings and erosion control blankets were evaluated over two growing seasons to determine their effect on soil properties and native grass establishment at a Canadian limestone quarry and lime processing plant. A season (fall, spring) of soil amending and seeding did not significantly affect revegetation or soil properties. Site characteristics such as slope, aspect, initial soil nutrients and surrounding plant communities influenced early plant community development and overall effects of soil treatments. Erosion control blankets resulted in the highest seeded plant cover and the lowest non-seeded plant cover despite not significantly changing soil chemical properties. Total nitrogen and carbon significantly increased establishment of seeded grasses and non-seeded species. Increased nitrogen and carbon in the constructed soils were best achieved through addition of manure. Wood shavings did not favour establishment of vegetation and resulted in similar, and in some cases less, vegetation than the controls. Assisted revegetation increased plant cover from < 6 to 50% and reduced cover of non-seeded species. Amendments that modified both chemical and physical soil conditions were best to increase vegetation establishment in the harsh conditions of the quarry.

Cohen-Fernández, A. C.; Naeth, M. A.

2013-07-01

248

Erosion control blankets, organic amendments and site variability influenced the initial plant community at a limestone quarry in the Canadian Rocky Mountains  

NASA Astrophysics Data System (ADS)

Season of seeding and soil amendment with manure mix, wood shavings and erosion control blankets were evaluated over two growing seasons to determine their effect on soil properties and native grass establishment at a Canadian limestone quarry and lime processing plant. Season (fall, spring) of soil amending and seeding did not significantly affect revegetation or soil properties. Site characteristics such as slope, aspect, initial soil nutrients and surrounding plant communities influenced early plant community development and overall effects of soil treatments. Erosion control blankets resulted in the highest seeded plant cover and the lowest non seeded plant cover despite not significantly changing soil chemical properties. Total nitrogen and carbon significantly increased establishment of seeded grasses and non seeded species. Increased nitrogen and carbon in the constructed soils were best achieved through addition of manure. Wood shavings did not favour establishment of vegetation and resulted in similar, and in some cases less, vegetation than controls. Assisted revegetation increased plant cover from < 6 to 50% and reduced cover of non seeded species. Amendments that modified both chemical and physical soil conditions were best to increase vegetation establishment in the harsh conditions of the quarry.

Cohen-Fernández, A. C.; Naeth, M. A.

2013-02-01

249

MILA Antenna Control Unit Replacement Project  

NASA Technical Reports Server (NTRS)

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.

Bresette, Jeremy

2007-01-01

250

Supporting the Future Air Traffic Control Projection Process  

E-print Network

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 ...

Davison, H. J.

2003-01-01

251

The Tactical Tomahawk Weapons Control System: Interface Design Project  

E-print Network

Tomahawk cruise missile. The goals of this project were to: Design, develop and test interface conceptsThe Tactical Tomahawk Weapons Control System: Interface Design Project Student Team: Julie, and Alan Thomas Naval Surface Warfare Center Dahlgren, VA E-mail HarmanWL@nswc.navy.mil KEYWORDS: Cruise

Virginia, University of

252

Statistical Process Control. A Summary. FEU/PICKUP Project Report.  

ERIC Educational Resources Information Center

A project was conducted to develop a curriculum and training materials to be used in training industrial operatives in statistical process control (SPC) techniques. During the first phase of the project, questionnaires were sent to 685 companies (215 of which responded) to determine where SPC was being used, what type of SPC firms needed, and how…

Owen, M.; Clark, I.

253

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...

254

Validating and Improving Interrill Erosion Equations  

PubMed Central

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

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

2014-01-01

255

Validating and improving interrill erosion equations.  

PubMed

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

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

2014-01-01

256

Intelligence support to arms control. Study project  

SciTech Connect

This paper argues that intelligence support is critical to the success of arms control. It identifies and describes the roles of intelligence in the arms control process, describes the existing intelligence organizational structure for arms control support, and identifies and analyzes issues. The roles include support to policy formulation, support to treaty negotiation, support to ratification, and finally, during verification, support for the implementation of the treaty through monitoring. The Director of Central Intelligence is responsible for monitoring, while the Arms Control and Disarmament Agency has responsibility for verification. Adjudication of conflicting interpretations occurs within the NSC committee structure. For several reasons, intelligence cannot be expected to do the actual verification of an arms control treaty. Most importantly, determination of an acceptable degree of confidence is always a political issue, although based on military judgement. Assigning intelligence responsibility for monitoring, rather than verification, helps to limit the politicization of intelligence. Issues identified during the research for this paper were analyzed within three subgroups: those inherent in the intelligence discipline; these must be managed successfully to limit adverse impact on intelligence products. Second, issues and challenges inherent in arms control bureaucratic relationships; these are best managed by keeping separate the actual monitoring analysis and verification this gives the West justification for caution, and reinforces the need for continued emphasis on verification.

Grisham, A.E.

1990-04-09

257

Wind Erosion Research  

NSDL National Science Digital Library

Wind Erosion Research (WER) provides science-based wind erosion technology for environmentally, economically, and socially sustainable agriculture in the United States. This website introduces the Wind Erosion Equation (WEQ), the first model for estimating soil loss by wind from agricultural fields and the newly developed Wind Erosion Prediction System (WEPS) which provides new capabilities assessing plant damage and calculating suspension loss. Simulation models, multimedia archive and history of wind erosion research are available for educators and students.

2006-02-27

258

Gully erosion and environmental change: importance and research needs  

Microsoft Academic Search

Assessing the impacts of climatic and, in particular, land use changes on rates of soil erosion by water is the objective of many national and international research projects. However, over the last decades, most research dealing with soil erosion by water has concentrated on sheet (interrill) and rill erosion processes operating at the (runoff) plot scale. Relatively few studies have

J Poesen; J Nachtergaele; G Verstraeten; C Valentin

2003-01-01

259

Supporting the Future Air Traffic Control Projection Process  

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

260

Reactive Accelerated Cluster Erosion (race)  

NASA Astrophysics Data System (ADS)

Beams of ionized clusters of some thousand atoms are accelerated to about 100-keV kinetic energy to be used for area selective surface erosion. Mask projective cluster-impact lithography allows surface structuring in the submicron regime. Chemical reactions between the cluster and the target material may provide volatile reaction products facilitating ejecta removal. The reactive accelerated cluster erosion (RACE) process is applied to metals like copper and gold, to semiconductors such as silicon, and to insulators like glass, quartz, or sapphire, giving very smooth eroded surface and steep sidewalls.

Gspann, Jürgen

261

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

NASA Technical Reports Server (NTRS)

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.

Hayhurst, Kelly J. (Editor)

2008-01-01

262

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

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.

Law, V.J.

1993-03-15

263

TRMM project contamination control using molecular adsorbers  

Microsoft Academic Search

The Tropical Rainfall Measuring Mission (TRMM) is a spacecraft under development by the National Aeronautics and Space Administration (NASA) and the National Space Development Agency of Japan (NASDA) and is scheduled for launch in August 1997. The spacecraft design includes the use of numerous optical instruments and the thermal control surfaces. In addition to the inherent contamination sensitivities of the

Sharon Straka; Philip Chen; Shaun Thomson; Ron Bettini; Jack Triolo; Nancy Carosso

1996-01-01

264

Controlled Hydrogen Fleet and Infrastructure Demonstration Project  

SciTech Connect

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 viability of the vehicle requires an expected level of cost, comfort, safety and operation, especially driving range, that consumers require. This presents a classic 'chicken and egg' problem, which Ford believes can be solved with thoughtful implementation plans. The eighteen Ford Focus FCV vehicles that were operated for this demonstration project provided the desired real world experience. Some things worked better than expected. Most notable was the robustness and life of the fuel cell. This is thought to be the result of the full hybrid configuration of the drive system where the battery helps to overcome the performance reduction associated with time related fuel cell degradation. In addition, customer satisfaction surveys indicated that people like the cars and the concept and operated them with little hesitation. Although the demonstrated range of the cars was near 200 miles, operators felt constrained because of the lack of a number of conveniently located fueling stations. Overcoming this major concern requires overcoming a key roadblock, fuel storage, in a manner that permits sufficient quantity of fuel without sacrificing passenger or cargo capability. Fueling infrastructure, on the other hand, has been problematic. Only three of a planned seven stations were opened. The difficulty in obtaining public approval and local government support for hydrogen fuel, based largely on the fear of hydrogen that grew from past disasters and atomic weaponry, has inhibited progress and presents a major roadblock to implementation. In addition the cost of hydrogen production, in any of the methodologies used in this program, does not show a rapid reduction to commercially viable rates. On the positive side of this issue was the demonstrated safety of the fueling station, equipment and process. In the Ford program, there were no reported safety incidents.

Dr. Scott Staley

2010-03-31

265

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...

266

Serials Control and Deselection Projects. SPEC Kit 147.  

ERIC Educational Resources Information Center

This Systems and Procedures Exchange Center (SPEC) Kit on serials control and deselection projects provides a timely review of the efforts of research libraries to control the increasing costs of serial subscriptions. This kit contains documents from 13 libraries: University of California at Los Angeles and Riverside; Universities of Florida,…

Association of Research Libraries, Washington, DC. Office of Management Studies.

267

Apollo Soyuz Test Project photographic processing control plan  

Microsoft Academic Search

The laboratory controls to be used within the photographic technology division (PTD) for processing original space flight films exposed on the Apollo Soyuz Test Project mission are specified. The sensitometric exposures to be used by PTD for certifying processes, for exposing Houston Controls, and for preflight and postflight exposures on original films as well as procedures for film certification are

H. E. Lockwood

1975-01-01

268

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

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.

Dorraj, Golnar; Moghimi, Hamid Reza

2015-01-01

269

CLEAR LAKE BASIN 2000 PROJECT  

SciTech Connect

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.

LAKE COUNTY SANITATION DISTRICT

2003-03-31

270

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

SciTech Connect

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.

Not Available

1981-01-01

271

Microprocessor-based monitoring and control project: Phase 2 report  

SciTech Connect

This report summarizes the activities of Phase II of the microprocessor-based monitoring and control project. The object of this multiphase project in the Electrical Systems Group of TVA's Division of Energy Demonstration and Technology (ED and T) is the development of microprocessor-based systems for special-purpose applications in monitoring, control, and protection of the power system. Phase II dealt with the hardware enhancements and software development to simulate the switching of the 46-kV capacitor banks at the Concord substation for voltage and VAR control.

Not Available

1986-09-01

272

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

NASA Technical Reports Server (NTRS)

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.

Stephan, Ryan A.

2010-01-01

273

F-15 837 IFCS Intelligent Flight Control System Project  

NASA Technical Reports Server (NTRS)

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.

Bosworth, John T.

2007-01-01

274

THE SWIRL CONCENTRATOR FOR EROSION RUNOFF TREATMENT  

EPA Science Inventory

A device for the partial removal of erosion products in stormwater runoff has been developed. The swirl concentrator as an erosion control device has been designed to concentrate the heavier soils from large flows. The concentrated underflow of up to 14 percent of the flow can be...

275

Mechanisms of polymer degradation and erosion  

Microsoft Academic Search

The most important features of the degradation and erosion of degradable polymers in vitro are discussed. Parameters of chemical degradation, which is the scission of the polymer backbone, are described such as the type of polymer bond, pH and copolymer composition. Examples are given how these parameters can be used to control degradation rates. Degradation leads finally to polymer erosion,

Achim Göpferich

1996-01-01

276

Rainfall profile characteristics in erosive and not-erosive events  

NASA Astrophysics Data System (ADS)

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 considered as a heavy storm and included in the analysis. The rainfall event is defined as a sequence of rainless and rainy periods defined as burst. The statistical expressions for the time distribution of erosive and not-erosive rainfalls were derived and the rainfall factors that influence the time distribution characteristics and that characterize an erosive event compared to a not erosive event were identified. The time distribution of erosive and not erosive storms have been expressed as cumulative percentages of storm rainfall and storm duration to make valid comparisons between storms and to simplify analysis presentation of data. The time distribution models presented as probability distributions, provide quantitative measures of both the inter-storm variability and the general characteristics of the time sequence of precipitation in storms. Other characteristics derived and analyzed, that are pertinent in classification of storms, include the number and the duration of individual runs in the total storm period, the total severity of the runs, the location of the heaviest run in the storm period, the percentage of the total storm period that had occurred at the start and end of this run, the percentage of the total storm rainfall preceding the heaviest run, the percentage of the total storm rainfall occurring at the heaviest run, the percentage of total storm rainfall occurring at the shower that contain the heaviest run, the percentage of the total storm period during which rain actually fell. The results obtained should aid the hydrologist in design problems or other application such as: the design of experiments for soil erosion study corresponding with the comparable measures of natural events (Agassi et al., 1999; Dunkerley, 2008; Kinnell, 2005; Mathys et al., 2005;) both in intra-storm dynamic and overall characteristics (Hanke et al., 2004); or the extrapolation of the erosive event inter-storm characteristics in which the time distribution is a pertinent factor.

Todisco, Francesca

2014-05-01

277

Experiences in the design of CRA`s for erosion/corrosion control in the production facilities of eastern Venezuela oil fields  

SciTech Connect

It is a well known fact that CRA`s are used in the oil industry as one way to control erosion/corrosion effects. Many fields in the eastern region of Venezuela are considered corrosive due to the presence of CO{sub 2} (5 to 20%), H{sub 2}S (up to 5 ppm), and water (50% water cut) contained in the produced hydrocarbons (condensated). For some areas, the hydrocarbon is accompanied by sand, making them erosive as well. These conditions and frequent failures experienced in the field, led to the use of CRA`s. For the wells, 13% Cr and bimetallic (carbon steel/13% Cr) tubing was used for 51 condensate wells containing 5 to 20% CO{sub 2}. For the surface equipment (valves, reducers, expanders and other types of fittings) tungsten carbide hard facing were used, for some of the valves, a epoxi-phenolic coating was used. This article describes the different design criteria used for the installation of the tubing, the logistics involved during field inspections and handling tips to avoid galling during workovers. It also, presents results from the bi-metallic tubing and the hard facings used for the surface equipment.

Romero, N. [CORPOVEN, S.A., Anaco (Venezuela); Palacios, C.A. [CORPOVEN, S.A., Puerto La Cruz (Venezuela). Ingenieria de Petroleo

1997-08-01

278

332: 418 --Project 3 --Spring 2006 Design of a Controller for a Vehicle Lateral Dynamics Control  

E-print Network

PART A: CONTROLLER ANALYTICAL DESIGN AND MATLAB SIMULATION (10 points) The error of the lateral a control engineering point of view: a) Find the open-loop transfer function and make a conclusion about332: 418 --Project 3 -- Spring 2006 Design of a Controller for a Vehicle Lateral Dynamics Control

Gajic, Zoran

279

Internal erosion and impact of erosion resistance  

Technology Transfer Automated Retrieval System (TEKTRAN)

The two most common causes of earthen embankment and levee failure are embankment overtopping and internal erosion. Internal erosion occurs when water flows through a cavity, crack, and/or other opening within the embankment. These openings may be a result of inadequate compaction during construct...

280

SOIL MANAGEMENT AND CONSERVATION: EROSION: WIND EROSION  

Technology Transfer Automated Retrieval System (TEKTRAN)

This manuscript is a chapter for the Encyclopedia of Soils in the Environment on Wind Erosion. The chapter includes discussion of the wind profile, modes of particle transportation, soil surface conditions, effect of vegetation, wind erosion modeling, sampling, use of radioisotope tracers to estimat...

281

Runoff generation and soil erosion processes after clear-cuttings  

NASA Astrophysics Data System (ADS)

Timber harvesting by large scale clear-cut is known to impose environmental impact including severe disturbance of the soil-hydraulic properties which in turn intensify surface runoff and soil erosion in both frequency and magnitude. However, it remains unanswered if such clear-cut harvest areas act rather as sources or sinks for runoff and soil erosion and whether such behaviour is steady or dynamically alternating. For this purpose, 92 small scale rainfall simulations of different intensities were carried out under pine plantation conditions and on two clear-cut harvest areas of different age in the Chilean Coastal Range. Non-parametrical Random Forest statistical models were set up to quantify the impact of environmental variables on the hydrological and erosion response. The plot-scale responses were linked to observations at the catchment outlets. Against all expectations, infiltration rates slightly increased after logging while runoff initiated fastest and generated highest infiltration excess rates under plantation forest floor regardless of the applied rainfall intensity. Exceeding a threshold rainfall intensity of 20 mm/h, the clear-cut areas started to act as a source for both runoff and erosion after connectivity established while they remained a sink under lower applied rainfall intensities. Post-logging soil erosion increased by two orders of magnitude compared with unlogged conditions highlighting the importance of reforestation immediately after the timber harvest. The results suggest that surface runoff connectivity by overcoming microtopography restrictions, preferential flow along recent and former root systems and water repellence control runoff generation and soil erosion processes in such environments. Fast hydrological response to rainfall, sediment-discharge-hystereses and enhanced post-logging groundwater recharge at catchment scale support our interpretation. The persistent impact of timber harvest by clear-cut practice implies that inter-harvest periods of 24 years are too short to allow complete recovery of the initial soil-hydraulic conditions. The authors thank Project CONICYT-BMBF 243-2010.

Iroume, A.; Mohr, C. H.; Bronstert, A.; Huber, A.

2012-12-01

282

Erosion in Our World  

NSDL National Science Digital Library

This activity is a field investigation where students find real-life examples of erosion in their school surroundings. Students will extend what they learned during stream table lessons about erosion, deposition, deltas, meandering streams, and dams.

Abbey Payeur

283

Improving soil bioengineering techniques to control erosion and sedimentation within the context of torrential Mediterranean climate: a French-Canadian experience  

NASA Astrophysics Data System (ADS)

On marly eroded terrains of the French Southern Alps, many researches are undertaken in order to better understand the role of vegetation and bioengineering works on erosion and sedimentation control. To this view, the eroded marly gullies of the French Southern Alps are an experimental design where an original French strategy of rehabilitation, developed by scientists from Irstea (ex-Cemagref), has been tested since 2002. It is comprised of the construction of bioengineering works, namely of "brush layers and brush mats of cuttings on deadwood microdams", and implements the use of willow cuttings (Salix purpurea and S. incana). The main objective of these works is to sustainably trap and retain marly sediment, by checking their performance (growth and survival of the cuttings, sediment trapping) in a mountainous and Mediterranean climate. In Canada, several private companies have developed their own knowledge and expertise in the conception and building of bioengineering works for erosion control, especially in the context of hilly and mountainous landscapes and climates. Therefore, it was decided to use the competence and expertise of Terra Erosion Control Ltd., a Canadian company, in the French torrential Mediterranean climate. Ten modalities were tested, the aims being to develop and/or to modify existing designs of current techniques, to experiment with other live cuttings (Populus nigra) and rooted species (Alnus spp. and Hippophae spp.), to evaluate and compare the potential use of different organic soil amendments in order to increase beneficial soil microorganisms and finally, to evaluate the potential use of specialized tools and equipment in order to increase the efficiency of the installation for vegetation establishment and sediment trapping, while decreasing the implementation costs. The experimental design was installed in March 2011 and the early observations in Spring 2012 showed that: 1/ most of the cuttings and the plants resisted to burial and to drought conditions; in particular, the structures using wooden boards instead of locally harvested logs appeared to be holding up well; 2/ designs of current techniques with vertical cuttings were better for resprouting and sediment trapping; 3/ 0.8m live cuttings of Populus nigra may represent an alternative to Salix spp., but resprout appeared lower; 4/ it was not possible to evaluate the performance of rooted species (Alnus spp. and Hippophae spp.); therefore more experiment is needed, especially with longer plants; 5/ organic soil amendments may increase vegetation development (BRF > fertilizer > compost > mixes). By comparing the results with similar sites used as benchmarks, installed since 2002, further observations in the spring of 2013 will allow us to evaluate the efficiency of the different modalities to improve vegetation establishment and sediment trapping.

Rey, Freddy; Louis, Séverine; Burylo, Mélanie; Raymond, Pierre

2013-04-01

284

Anthropogenic Effects on Erosion  

NSDL National Science Digital Library

This exercise focuses on anthropogenic effects on erosion. It could be run as a single lab or as a series of in-class exercises or problem sets. We discussed an article by Hooke and used it as a launching pad for a discussion of back of the envelope calculations. Students then estimate the volume moved by mountain-top removal and how long it might take a river to mobilize that sediment. They estimate the cost for beach nourishment along Florida beaches. They estimate the contribution of local construction projects and road gravel to stream sediment loads. This activity gives students a chance to formulate a problem, make simple measurements, estimate unknowns, and calculate volumes, rates, and costs of various human earth-moving activities. Designed for a geomorphology course Addresses student fear of quantitative aspect and/or inadequate quantitative skills Uses geomorphology to solve problems in other fields

Karen Gran

285

Erosion resistant coatings  

NASA Technical Reports Server (NTRS)

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.

Falco, L.; Cushini, A.

1981-01-01

286

PREDICTING MINESOIL EROSION POTENTIAL  

EPA Science Inventory

Two experimental plots were instrumented with erosion pins to study the correspondence between point erosion and erosion over an area on strip mine soil. Using a rotating boom rainfall simulator, data were collected by sampling the runoff every five minutes for the duration of th...

287

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

NASA Astrophysics Data System (ADS)

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 tool for inclusion in future projections of the spatial variability of erosion and sediment yield, as models capture pressure fields reliably.

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

288

Instrument remote control project at TNG: SARG implementation  

NASA Astrophysics Data System (ADS)

The high resolution spectrograph at TNG (SARG), mounted at the telescope in 2000, is based on the 'first generation CCD controller, transputers and VME real time computer that control the instrument and the detectors. The evolution of the CCD controller, with high performance in speed acquisition and transfer rate, has changed the architecture of the instrument control. Due to the high performances of modern LAN, it has become possible to have direct access to CCD controller and instruments features. The architecture is based on a remote system, connected to a local system through standard network facilities and communicating with it using an XML-like syntax. The remote system receives from the local system commands and, in turn, sends back telemetry and images. This control system will be tested for the first time with the SARG spectrograph, in the framework of the Instruments remote control project at the Telescopio Nazionale Galileo (TNG).

Cosentino, Rosario; Bruno, Pietro; Gonzalez, Manuel; Huertas, Manuel; Scuderi, Salvatore

2004-09-01

289

Project Management Using Modern Guidance, Navigation and Control Theory  

NASA Technical Reports Server (NTRS)

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 of the system. The behavior of a system, as captured in the system modeling, when properly done will aid in accurately predicting future system performance. The Feedback Control system understands the state and behavior of the system and uses feedback to adjust control inputs into the system. The feedback, which is the right arm of the Control system, allows change to be affected in the overall system; it therefore is important to not only correctly identify the system feedback inputs, but also the system response to the feedback inputs. The Navigation system takes multiple data inputs and based on a priori knowledge of the inputs, develops a statistically based weighting of the inputs and measurements to determine the system's state. Guidance and Planning Logic of the system, complete with an understanding of where the system is (provided by the Navigation system), will in turn determine where the system needs to be and how to get it there. With any system/project, it is critical that the objective of the system/project be clearly defined -- not only to plan but to measure performance and to aid in guiding the system or the project. The system principles discussed above, which can be and have been applied to the current CxP space suit development project, can also be mapped to real-world constituents, thus allowing project managers to apply systems theories that are well defined in engineering and mathematics to a discipline (i.e., Project Management) that historically has been based in personal experience and intuition. This mapping of GN&C theory to Project Management will, in turn, permit a direct, methodical approach to Project Management, planning and control providing a tool to help predict (and guide) performance and an understanding of the project constraints, how the project can be controlled, and the impacts to external influences and inputs. This approach, to a project manager, flows down to the three bottom-line variables of cost, schedule, and scope ando the needed control of these three variables to successfully perform and complete a pr

Hill, Terry R.

2011-01-01

290

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

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.

Law, V.J.

1995-09-18

291

15 CFR 923.25 - Shoreline erosion/mitigation planning.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Shoreline erosion/mitigation planning. 923.25 Section...Management Areas § 923.25 Shoreline erosion/mitigation planning. (a) The...control, or lessen the impact of, shoreline erosion, including potential impacts of...

2012-01-01

292

15 CFR 923.25 - Shoreline erosion/mitigation planning.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Shoreline erosion/mitigation planning. 923.25 Section...Management Areas § 923.25 Shoreline erosion/mitigation planning. (a) The...control, or lessen the impact of, shoreline erosion, including potential impacts of...

2013-01-01

293

The Basics of Agricultural Erosion and Sedimentation Requirements  

E-print Network

The Basics of Agricultural Erosion and Sedimentation Requirements On November 19, 2010, additions and changes to long-standing PA Chapter 102 regulations addressing Erosion and Sediment (E&S) Control erosion when plowing and tilling (includes no-till cropping). Chapter 102 always (since 1972) stated

Guiltinan, Mark

294

15 CFR 923.25 - Shoreline erosion/mitigation planning.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 2014-01-01 false Shoreline erosion/mitigation planning. 923.25 Section...Management Areas § 923.25 Shoreline erosion/mitigation planning. (a) The...control, or lessen the impact of, shoreline erosion, including potential impacts of...

2014-01-01

295

15 CFR 923.25 - Shoreline erosion/mitigation planning.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Shoreline erosion/mitigation planning. 923.25 Section...Management Areas § 923.25 Shoreline erosion/mitigation planning. (a) The...control, or lessen the impact of, shoreline erosion, including potential impacts of...

2011-01-01

296

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, ...

297

Advanced Guidance and Control Project for Reusable Launch Vehicles  

NASA Technical Reports Server (NTRS)

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.

Hanson, John M.

2000-01-01

298

Links between erosion, runoff variability, and seismicity in the Taiwan orogen  

Microsoft Academic Search

Erosion of mountain belts controls their topographic and structural evolution and is the main source of sediment delivered to the oceans. While mountain erosion rates have been estimated from relief and precipitation, full evaluation of controls on erosion rates and patterns is challenging and requires detailed measurements across multiple time-scales. We report erosion rates in the Taiwan mountains estimated from

Simon J. Dadson; Niels Hovius; Hongey Chen; W. Brian Dade; Meng-Long Hsieh; Sean D. Willett; Jyr-Ching Hu; Ming-Jame Horng; Meng-Chiang Chen; Colin P. Stark; Dimitri Lague; Jiun-Chuan Lin

2003-01-01

299

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

SciTech Connect

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)

Not Available

1985-12-30

300

Environmental Impact Statement Truckee Meadows Flood Control Project  

E-print Network

DRAFT Environmental Impact Statement for the Truckee Meadows Flood Control Project Nevada General Reevaluation Report Volume I ­ Draft Environmental Impact Statement prepared by U.S. Army Corps of Engineers Sacramento District May 2013 #12;#12;DRAFT Environmental Impact Statement for the Truckee Meadows Flood

US Army Corps of Engineers

301

Control Aspects of the Tacoma Superconducting Magnetic Energy Storage Project  

Microsoft Academic Search

On February 16, 1983, a 10 MW\\/30 MJ superconducting magnetic energy storage unit was energized at the Bonneville Power Administration (BPA) substation in Tacoma, Washington. The unit was retired a year later, after extensive tests directed toward its experimental use as a small-signal stabilizer for the Pacific AC Intertie. This paper addresses the control aspects of the project. These include

J. F. Hauer; H. J. Boenig

1987-01-01

302

Multivariate statistical process control based on multiway locality preserving projections  

Microsoft Academic Search

An approach for multivariate statistical process control based on multiway locality preserving projections (LPP) is presented. The recently developed LPP is a linear dimensionality reduction technique for preserving the neighborhood structure of the data set. It is characterized by capturing the intrinsic structure of the observed data and finding more meaningful low-dimensional information hidden in the high-dimensional observations compared with

Kunlun Hu; Jingqi Yuan

2008-01-01

303

Coherence of erodibility for erosion processes and different scales  

Technology Transfer Automated Retrieval System (TEKTRAN)

Erosion is one of the least reliably defined elements of many hydraulic projects. Earthen embankments (i.e. dams and levees) are an example of hydraulic projects for which erosion and erodibility have not been reliably defined in the past. Characterizing material erodibility is one of the essentia...

304

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Small flood control project authority (Section 205...OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.23 Small flood control project authority (Section...

2013-07-01

305

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

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Small flood control project authority (Section 205...OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.23 Small flood control project authority (Section...

2014-07-01

306

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Small flood control project authority (Section 205...OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.23 Small flood control project authority (Section...

2011-07-01

307

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

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Small flood control project authority (Section 205...OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.23 Small flood control project authority (Section...

2010-07-01

308

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

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Small flood control project authority (Section 205...OF DEFENSE CONTINUING AUTHORITIES PROGRAMS Flood Control Policy § 263.23 Small flood control project authority (Section...

2012-07-01

309

Evaluation of the Serum Zinc Level in Erosive and Non-Erosive Oral Lichen Planus  

PubMed Central

Statement of Problem: Lichen planus is a chronic inflammatory immunologic-based disease involving skin and mucosa. This disease is generally divided into two categories: erosive and non-erosive. Many etiologic factors are deliberated regarding the disease; however, the disorders of immune system and the role of cytotoxic T-lymphocytes and monocytes are more highlighted. Zinc is an imperative element for the growth of epithelium and its deficiency induces the cytotoxic activity of T-helper2 cells, which seems to be associated with lichen planus. Purpose: This study was aimed to evaluate the levels of serum zinc in erosive and non-erosive oral lichen planus (OLP) and to compare it with the healthy control group to find out any feasible inference. Materials and Method: A total of 22 patients with erosive oral lichen planus, 22 patients with non erosive OLP and 44 healthy individuals as the control group were recruited in this descriptive-comparative study. All the participants were selected from the referees to the department of oral medicine, school of dentistry, Tabriz University of Medical Sciences. Serum zinc level was examined for all the individuals with liquid-stat kit (Beckman Instruments Inc.; Carlsbad, CA). Data were analyzed by adopting the ANOVA and Tukey tests, using SPSS 16 statistical software. Results: The mean age of patients with erosive and non-erosive LP was 41.7 and 41.3 years, respectively. The mean age of the healthy control group was 34.4 years .The mean serum zinc levels in the erosive and non erosive lichen planus groups and control groups were 8.3 (1.15), 11.15 (0.92) and 15.74 (1.75) ?g/dl respectively. The difference was statistically significant (p< 0.05). Conclusion: The serum zinc levels were decreased in patients with erosive oral lichen planus. This finding may probably indicate the promising role of zinc in development of oral lichen planus. PMID:24883340

Gholizadeh, N.; Mehdipour, M.; Najafi, Sh.; Bahramian, A.; Garjani, Sh.; Khoeini Poorfar, H.

2014-01-01

310

Soil Erosion Protection Potential of Young Paulownia Plantation  

NASA Astrophysics Data System (ADS)

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 N-NO3- are 0.994 kg/ha from plated plots and 0.718 kg/ha from bare soils and the losses of N-NH4+ are respectively 0.042 and 0.117 kg/ha. The results from biometrics showed that 58 % of the plants were found to have stroken roots; an average growth of 0.3 m and a mean increase in the number of leaves with 3 were recorded. The results reported here show that the losses of soil and nutrients from the field plots planted with Paulownia Bellissima are about 40 % higher than these from the plot with bare soil. This discouraging result needs further experimental and theoretical analyses. The research throughout the following years will give further information about the soil erosion protection potential of young Paulownia plantation.

Stepchich, Avgusta; Djodjov, Christo

2014-05-01

311

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

NASA Astrophysics Data System (ADS)

This work explores how soil erosion assessments can be structured in the context of ecological sites and site dynamics to inform systems for managing accelerated soil erosion. We evaluated wind and water erosion rates for five ecological sites in southern New Mexico, USA, using monitoring data and rangeland-specific wind and water erosion models. Our results show that wind and water erosion can be highly variable within and among ecological sites. Plots in shrub-encroached and shrub-dominated states were consistently susceptible to both wind and water erosion. However, grassland plots and plots with a grass-succulent mix had a high indicated susceptibility to wind and water erosion respectively. Vegetation thresholds for controlling erosion are identified that transcend the ecological sites and their respective states. The thresholds define vegetation cover levels at which rapid (exponential) increases in erosion rates begin to occur, suggesting that erosion in the study ecosystem can be effectively controlled when bare ground cover is <20% of a site or total ground cover is >50%. Similarly, our results show that erosion can be controlled when the cover of canopy interspaces >50 cm in length reaches ~50%, the cover of canopy interspaces >100 cm in length reaches ~35% or the cover of canopy interspaces >150 cm in length reaches ~20%. This process-based understanding can be applied, along with knowledge of the differential sensitivity of vegetation states, to improve erosion management systems. 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 sites to erosion. Land use impacts that are constrained within the natural variability of sites should not result in accelerated soil erosion. Evaluating land condition against the erosion thresholds and natural variability of ecological sites will enable improved identification of where and when accelerated soil erosion occurs and the development of practical management solutions.

Webb, N.; Herrick, J.; Duniway, M.

2013-12-01

312

Project Management Using Modern Guidance, Navigation and Control Theory  

NASA Technical Reports Server (NTRS)

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, will develop a statistical-based weighting of the input to determine where the system currently is located. Guidance and Planning logic of the system with the understanding of where it is (provided by the navigation system) will in turn determine where it needs to be and how to get there. Lastly, the system Feedback system is the right arm of the control system to allow it to affect change in the overall system and therefore it is critical to not only correctly identify the system feedback inputs but also the system response to the feedback inputs. And with any systems project it is critical that the objective of the system be clearly defined for not only planning but to be used to measure performance and to aid in the guidance of the system or project.

Hill, Terry

2010-01-01

313

Preventing inadmissible erosion-corrosion thinning from occurring in the diffuser segments of feedwater supply control systems of power units at nuclear power stations equipped with RBMK-1000 reactors  

NASA Astrophysics Data System (ADS)

Results obtained from investigations of erosion-corrosion processes that occur during operation of the feedwater supply control systems used in power units of nuclear power stations equipped with RBMK-1000 reactors and the sensitivity of these processes to variations in the chemical composition of metal and in the flow path geometry are presented. It is found that local erosion-corrosion thinning of the walls in the diffuser segments of feedwater supply control systems occur mainly due to intense mass transfer in the near-wall region taken in combination with a low content of chromium. Hydrodynamic simulation was carried out, and it was shown based on its results that local erosion-corrosion thinning of the walls of pipeline segments downstream of the valves controlling the supply of feedwater to power units of nuclear power stations equipped with RBMK-1000 reactors can be prevented by subjecting them to appropriate modernization. It is found that the above mentioned diffuser parts can be made more resistant to erosion-corrosion wear by keeping the content of chromium in the main metal and weld joints at a level of no less than 0.25% and concurrently reducing the hydrodynamic effect in the zones of weld connections.

Tomarov, G. V.; Shipkov, A. A.; Golubeva, T. N.; Greblov, P. N.

2013-05-01

314

Control and Coordination Research & Integrated Management System Development of Chemical Engineering Project Design  

Microsoft Academic Search

Integration and Informatization management of engineering project is the effective way to improve project management. How to use the limited resource and the lowest cost to implement integrated management is the goal of the project manager. On the ground of analyzing characteristics of modern chemical engineering project design, This paper focuses on quality control, progress control and coordination control of

Xiajie Jin; Caixin Lin

2010-01-01

315

Weathering and Erosion  

NSDL National Science Digital Library

In this multi-station lab, learners conduct a series of experiments to explore the processes and effects of weathering and erosion. Using the results from these explorations, learners design and conduct an experiment comparing the rate of erosion in different biomes. Use this activity to teach weathering and erosion, and also to illustrate how scientists often use the results of one experiment to inspire another. This activity is intended to be conducted over multiple meetings.

Lise Whitfield

2010-01-01

316

Geomorphic considerations for erosion prediction  

USGS Publications Warehouse

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.

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

1997-01-01

317

Controlled Hydrogen Fleet and Infrastructure Demonstration and Validation Project  

SciTech Connect

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.

Stottler, Gary

2012-02-08

318

NIF Projects Controls and Information Systems Software Quality Assurance Plan  

SciTech Connect

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.

Fishler, B

2011-03-18

319

An investigation of the effect of hydrodynamics of flow on erosion-corrosion resistance of components of a feedwater control assembly used in power units of nuclear power plants equipped with RBMK-1000 reactors  

NASA Astrophysics Data System (ADS)

The results of computational hydrodynamic simulation of the flow of a working medium in the flow path of the feedwater control assembly used in power units of nuclear power plants (NPPs) equipped with the reactors of the RBMK-1000 type are presented It was established that the rate of control valve opening has an influence on the position of the areas of the intense local erosion-corrosion thinning of metal of the diffuser section downstream of the valve.

Tomarov, G. V.; Shipkov, A. A.; Golubeva, T. N.; Greblov, P. N.

2013-08-01

320

Soil Erosion and Agricultural Sustainability  

Microsoft Academic Search

Data drawn from a global compilation of studies support the long articulated contention that erosion rates from conventionally plowed agricultural fields greatly exceed rates of soil production, erosion under native vegetation, and long-term geological erosion. Whereas data compiled from around the world show that soil erosion under conventional agriculture exceeds both rates of soil production and geological erosion rates by

D. R. Montgomery

2009-01-01

321

Modeling vegetation coverage and soil erosion in the Loess Plateau Area of China  

Microsoft Academic Search

Soil erosion is still one of major issues limiting agricultural and forestry productivity in Loess Plateau of China. Vegetation plays an important role in controlling soil erosion, but studies on modeling dynamics of vegetation and soil erosion and interaction between them were hardly reported. We hypothesized that changes of vegetation coverage and soil erosion as affected by climate factors and

Z. C. Zhou; Z. P. Shangguan; D. Zhao

2006-01-01

322

Greenridge Multi-Pollutant Control Project Preliminary Public Design Report  

SciTech Connect

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 commercial readiness of an emissions control system that is specifically designed to meet the environmental compliance requirements of these smaller coal-fired EGUs. The multi-pollutant control system is being installed and tested on the AES Greenidge Unit 4 (Boiler 6) by a team including CONSOL Energy Inc. as prime contractor, AES Greenidge LLC as host site owner, and Babcock Power Environmental Inc. as engineering, procurement, and construction contractor. All funding for the project is being provided by the U.S. Department of Energy, through its National Energy Technology Laboratory, and by AES Greenidge. AES Greenidge Unit 4 is a 107 MW{sub e} (net), 1950s vintage, tangentially-fired, reheat unit that is representative of many of the 440 smaller coal-fired units identified above. Following design and construction, the multi-pollutant control system will be demonstrated over an approximately 20-month period while the unit fires 2-4% sulfur eastern U.S. bituminous coal and co-fires up to 10% biomass. This Preliminary Public Design Report is the first in a series of two reports describing the design of the multi-pollutant control facility that is being demonstrated at AES Greenidge. Its purpose is to consolidate for public use all available nonproprietary design information on the Greenidge Multi-Pollutant Control Project. As such, the report includes a discussion of the process concept, design objectives, design considerations, and uncertainties associated with the multi-pollutant control system and also summarizes the design of major process components and balance of plant considerations for the AES Greenidge Unit 4 installation. The Final Public Design Report, the second report in the series, will update this Preliminary Public Design Report to reflect the final, as-built design of the facility and to incorporate data on capital costs and projected operating costs.

Daniel P. Connell

2009-01-12

323

Numerical simulation of the erosion in the 90° elbow  

NASA Astrophysics Data System (ADS)

In the process of natural gas transportation, cement production and coal-fired power, the gas-solid two-phase flow exists widely in pipelines. The existence of solid particles may cause the erosion of the pipeline, especially in the elbow of the pipeline. Equations used to predict erosion rate are usually obtained from well-controlled experimental tests for solid particles carried in a gas or liquid flow. The particle impact speed and impact angle affect the erosion process and are two major parameters in most erosion equations. In this paper, the erosion of 90° elbow was studied by using Computational Fluid Dynamics (CFD), Discrete Particle Model (DPM) and erosion equations. The maximum erosion rate and the erosion position were reported. Particle size does not influence the erosion rate when particle size is bigger than a certain degree. When the mass ratio of sand loading to fluid is less than 1, erosion ratio is proportional to the loading mass. The erosion rate is lower for larger radius elbow, and the erosion rate is greatly declined by using the plugged tee instead of an elbow.

Deng, Yunzhong; Liu, Yinhe; Chen, Jianying; Zhang, Yongjian

2013-07-01

324

Erosion-corrosion of metals and alloys at high temperatures  

Microsoft Academic Search

This project was undertaken to investigate the possibility of developing guidelines for the incorporation of erosion resistance into high-temperature alloys. An apparatus was developed to allow the laboratory study of erosion of a number of alloys over a range of conditions of erosion at temperatures up to 760°C (1400°F). The results of extensive studies showed that the conventional guideline of

I. G. Wright; V. Nagarajan; W. E. Merz

1984-01-01

325

Scales and erosion  

Technology Transfer Automated Retrieval System (TEKTRAN)

There is a need to develop scale explicit understanding of erosion to overcome existing conceptual and methodological flaws in our modelling methods currently applied to understand the process of erosion, transport and deposition at the catchment scale. These models need to be based on a sound under...

326

COASTAL EROSION EMERGENCY PLANNING  

Microsoft Academic Search

Approximately two thirds of the NSW open ocean coastline is characterised by sandy beaches. These beaches are highly dynamic, undergoing continual cycles of erosion and accretion in response to the variation of tides, wind and waves. In many places existing foreshore development has been built within the active beach system and is at risk from coastal erosion. With current predictions

D. J. Hanslow; A. Gissing

327

Saliva and dental erosion  

PubMed Central

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

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

2012-01-01

328

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...

329

Coastal Erosion Online Discussion  

NSDL National Science Digital Library

The students are given the following: Read the articles below about erosion along the Lake Erie shoreline and discuss them. What causes the erosion? What can be done to prevent erosion? Should people be allowed to build structures to protect their property from erosion? Should people be allowed to live along the shoreline in high erosion areas? Students are expected to have completed the coastal erosion module (read text book, view powerpoint lecture and take a quiz) and read articles regarding coastal erosion along the Lake Erie coastline. In the online discussion, students must show that they understand coastal processes, the impact of man made structures on coastal processes, and can apply their values as they discuss what should be done, if anything, to reduce the impact of coastal erosion. Teaching Tips Adaptations that allow this activity to be successful in an online environment This was designed as an online activity. I have also used it in face-to-face courses (students participate in online discussion prior to in-class discussion). Elements of this activity that are most effective This gets students thinking about how what they learn in class can be used to solve real problems faced by the local community and/or the world. Although some students propose impractical solutions, they are at least thinking. Recommendations for other faculty adapting this activity to their own course: Find local issues and/or global issues that show how geology can be used to solve problems.

Sheila Roberts

330

The Large Synoptic Survey Telescope project management control system  

NASA Astrophysics Data System (ADS)

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.

Kantor, Jeffrey P.

2012-09-01

331

Rainfall erosivity in Europe.  

PubMed

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 60min. The R-factor values calculated from precipitation data of different temporal resolutions were normalised to R-factor values with temporal resolutions of 30min using linear regression functions. Precipitation time series ranged from a minimum of 5years to a maximum of 40years. The average time series per precipitation station is around 17.1years, 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 1km 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 722MJmmha(-1)h(-1)yr(-1), with the highest values (>1000MJmmha(-1)h(-1)yr(-1)) in the Mediterranean and alpine regions and the lowest (<500MJmmha(-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. PMID:25622150

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

2015-04-01

332

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

SciTech Connect

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.

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

1996-12-31

333

Self-organization of control circuits for invariant fiber projections.  

PubMed

Assuming that patterns in memory are represented as two-dimensional arrays of local features, just as they are in primary visual cortices, pattern recognition can take the form of elastic graph matching (Lades et al., 1993 ). Neural implementation of this may be based on preorganized fiber projections that can be activated rapidly with the help of control units (Wolfrum, Wolff, Lücke, & von der Malsburg, 2008 ). Each control unit governs a set of projection fibers that form part of a coherent mapping. We describe a mathematical model for the ontogenesis of the underlying connectivity based on a principle of network self-organization as described by the Häussler system (Häussler & von der Malsburg, 1983 ), modified to be sensitive to pattern similarity and to support formation of multiple mappings, each under the command of a control unit. The process takes the form of a soft-winner-take-all, where units compete for the representation of maps. We show simulations for invariant point-to-point and feature-to-feature mappings. PMID:25710088

Fernandes, Tomas; von der Malsburg, Christoph

2015-05-01

334

Project B610 process control configuration acceptance test report  

SciTech Connect

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: (1) proper assignment and operation of all field inputs to and outputs from the MICON Termination panels; (2) proper operation of all display data on the operators` console; (3) proper operation of all required alarms; and (4) proper operation of all required interlocks. This test only verifies the proper operation of the Westinghouse control configuration (or program). It will not be responsible for verifying proper operation of the MICON hardware or operating software. Neither does it test any of the B610 instrument. The MICON hardware and software has been tested as part of the equipment procurement. Instrumentation and wiring installed under project B620 will be tested under a separate functional test. In some cases, precise transmitter ranges, alarm setpoints, and controller tuning parameters are not available at this time. Therefore, approximate values are used during the test. This should not affect the proper operation of the configuration or the validity of this test. Final values will be assigned during operability testing.

Silvan, G.R.

1995-06-27

335

Splash erosion. A bibliometric Review  

NASA Astrophysics Data System (ADS)

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 and Netherlands. It is interesting to analyze the evolution of research by means of splash erosion publications. Figure 6 shows the number of documents published every decade from 1961 (the first publication appears in 1967) . Various aspects need to be commented: • The decades show an exponential increase in the number of publications. • The line in the figure represents the rise in the number of publications, which have been larger in the last two decades (900s and 20000s). • The last decade included began in 2001 leads us to predict a strong boost in research in this particular field. It is also worthwhile to consider briefly the main concepts dealt with in the documents published: • There are only 3 publications with disdrometer + splash erosion as topic words. • After 1991 and 2000 we find that there are several lines of measurement of two main research lines today are already defined: the study of the splash produces with rain simulation processes or splash produces with natural rain (relationship with atmospheric variables and accuracy of the measurements). • The current decade is characterized by an increase in research using disdrometers for studying splash erosion. Summing up, the research that is being carried out using splash erosion is evolving towards an increasing number of projects, countries, and especially, papers published in prestigious scientific journals.

Fernández Raga, M. B.

2012-04-01

336

Erosion of soil organic carbon: implications for carbon sequestration  

USGS Publications Warehouse

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.

Van Oost, Kristof; Van Hemelryck, Hendrik; Harden, Jennifer W.

2009-01-01

337

Technical Assistance Project for the Minnesota Pollution Control Agency  

SciTech Connect

This report was prepared in response to a request for technical assistance from the Minnesota Pollution Control Agency (MPCA). The U.S. Department of Energy's (DOE) Office of Energy Efficiency and Renewable Energy supported the National Renewable Energy Laboratory (NREL) in its response to this request through the Technical Assistance Project. Discussion with the MPCA identified the following as the highest-priority questions: What is the effect of (1) size of Renewable Energy Reserve (RER) and (2) duration of allocation award on (a) NOx emissions in Minnesota and (b) retail electricity prices? What data is available on the response of wind energy development to financial incentives? This report addresses those questions.

Vimmerstedt, L.

2006-12-01

338

Modeling of state of vegetation and soil erosion over large areas  

Microsoft Academic Search

A vegetation-erosion model was developed to assess the extent of soil erosion and development trend of vegetation in the context of existing and contemplated vegetation-based soil erosion controls under different climatic, topographical and soil conditions. The model recognizes four vegetation-mediated soil erosion states: (i) an expanding vegetation coverage coupled with reduced erosion (C), (ii) a deteriorating vegetation coverage coupled with

Zhao-Yin WANG; Guangqian WANG; Guohe HUANG

2008-01-01

339

Erosion in America  

SciTech Connect

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.

Not Available

1984-03-23

340

Erosion dynamics of a wet granular medium  

E-print Network

Liquid may give strong cohesion properties to a granular medium, and confer a solid-like 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.

Gautier Lefebvre; Pierre Jop

2014-12-08

341

Removing erosion control projects increases bank swallow ( Riparia riparia) population viability modeled along the Sacramento River, California, USA  

Microsoft Academic Search

Spatially-explicit population viability analysis (PVA) is a powerful method for modeling the extinction risk of populations that show variation over space and time. It is especially effective for comparing relative effect of different management scenarios on population dynamics. Here, I present a habitat patch-based PVA for a population of the California state-listed threatened bank swallow (Riparia riparia) nesting along the

Evan H. Girvetz

2010-01-01

342

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

NASA Astrophysics Data System (ADS)

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.

Kamkar Zahmatkesh, Niloofar

343

Naked Dirt: Erosion  

NSDL National Science Digital Library

This file explains that the United States Department of Agriculture developed the Universal Soil Loss Equation (revised in 1993 to RUSLE) to help farmers, landscapers, and architects decide how to prevent erosion. The equation predicts the rate of erosion for a site based on the annual rainfall, soil type, and degree of slope. The site includes a table that shows how different practices affect erosion rates. It explains that sediment pollution makes swimming and boating less fun, clogs city drinking water systems, fills in lakes, and smothers fish and insect habitat. Sediments often float awhile before settling out, making water cloudy or turbid. There is an explanation of which native grasses are best for holding the soil in place and other suggestions to stop erosion.

344

Ice Cream Erosion  

NSDL National Science Digital Library

This demonstration will help students identify and describe the process of erosion and transfer this knowledge from class exercises to real world examples. The teacher will explain the demonstration and how it depicts the process of erosion; students will make predictions about what will happen when hot chocolate is poured over ice cream, and record their predictions as well as their observations of what happens.

345

Weathering and Erosion  

NSDL National Science Digital Library

This unit provides an introduction for younger students to the concepts of weathering and erosion. Topics include types of weathering (physical versus chemical), rates of weathering, and weathering products (soil). The section on erosion explains the importance of water and gravity in the process, and discusses some of the more important erosional agents such as wind, water and ice, streams and glaciers. A vocabulary list and downloadable, printable student worksheets are provided.

Medina, Philip

346

Controls on decadal erosion rates in Qilian Shan: Re-evaluation and new insights into landscape evolution in north-east Tibet  

NASA Astrophysics Data System (ADS)

Available data from the Qilian Shan in north-east Tibet suggested that decadal-scale erosion rates were closely correlated with local topographic gradient, but not with climatic factors. However, a climatic change to more arid condition was proposed to explain the discrepancy between short-term and long-term erosion rates. In order to re-evaluate the topographic, tectonic and climatic influences on erosion, we adopted five parameters (slope, mean local relief, historical cumulative seismic moment, runoff coefficient of variation and fault density) to study 11 drainage basins in north-east Tibet. Our results showed that terrain gradient, rock fracture density and rainstorm intensity had strong influence on erosion rates while 60-year cumulative seismic moments of historical earthquakes showed weaker correlations. There was a spatial variation in the erosional mechanisms across the basin, with detachment-limited dominance around the ridges (slope > 20°) and deposition dominant in the flat areas. The variation may lead to the discrepancy between short-term and long-term erosion rates. In general, our study supports the ‘bath-tub’ model for low relief intermountain basins, hence providing new insights into the landscape evolution of the Qilian Shan in northeastern Tibetan Plateau.

Yizhou, Wang; Huiping, Zhang; Dewen, Zheng; Wenjun, Zheng; Zhuqi, Zhang; Weitao, Wang; Jingxing, Yu

2014-10-01

347

Understanding Subduction Erosion Through Scaled Sandbox Analogue Experiments  

NASA Astrophysics Data System (ADS)

The removal of material by tectonic erosion at ~60% of the Earth's convergent margins is a significant but still poorly understood process. We explored mass transfer processes and the structural evolution of erosive systems in a series of 2D sandbox experiments. A wedge-shaped sand body with an initial wedge geometry of 125 cm (length) x 30 cm (height) x 20 cm (width) represented the forearc in a sandbox 3 m long. A conveyor belt with a rough surface at the base simulated subducting oceanic crust. The initial slope angle ? was set to 13.5°, the basal angle ? to zero. For the system to develop dynamics similar to those observed in nature, the mechanical properties of the materials were properly scaled. Our study explored the role of a controlled volume of sediment leaving the sand wedge on its mechanics and dynamics by varying the width of the subduction window (Global Capacity GC) at the base of the back wall. We quantified our results, including frontal erosion (removing material from the tip of the slope), basal erosion (detachments from the base of the forearc, causing surface subsidence), subsidence, accretion and tip retreat, and compared them to natural examples of erosive convergent margins. Basal erosion, subsidence and frontal prism evolution are related to subduction channel (SC) characteristics. Volumes of frontal and basal erosion decrease as GC decreases. Basal erosion can amount to up to twice the frontal erosion in case of a sufficiently wide subduction window. As a consequence, wedges with large GCs produced erosion ratios (basal erosion/frontal erosion) > 1, in agreement with estimates from natural forearcs. Total erosion (i.e., frontal plus basal erosion) was favored by wide GCs. Commonly, the size of the frontal prism varied in size with the GC. "Accretionary" systems evolved in erosive systems by varying the GC, without adding sediment to the toe. Thinner GCs developed a higher number of backthrusts at the frontal slope. We identified three segments along the wedge and the SC, related to the mass transfer modes. At the toe, the total sediment entering the channel is restricted by the inlet capacity (IC). Volumes of eroded material correlate with the IC/GC-ratio. If IC ? GC, frontal erosion is controlled by GC; if IC > GC, by IC. In addition, the IC/GC-ratio also controlled basal erosion: when IC/GC>>1, basal erosion was very low; in contrast, when IC/GC

Albert, F.; Kukowski, N.; Tassara, A.; Oncken, O.

2012-04-01

348

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)

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 allow us to directly quantify the magnitude of sedimentation (and hence reversal of arroyo cutting) upstream of in-channel structures as a function of hydrology, and to quantify the dampening of flood energy caused by erosion control structures and by the restoration of riparian vegetation. We are also able to create a surface water budget that constrains water storage and infiltration by monitoring streamflow at several places above, within, and downstream of restoration efforts. We also speculate on the resilience of such efforts. Quantifying the effects of the restoration efforts at Rancho San Bernardino may prove useful in guiding similar large-scale ecological restoration efforts elsewhere in degraded dryland landscapes.

DeLong, S.; Henderson, W. M.

2012-12-01

349

Dating and quantification of erosion processes based on exposed roots  

NASA Astrophysics Data System (ADS)

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.

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

2013-08-01

350

Assessment of Soil Erosion at a DC Park Facility Spring Valley Park  

E-print Network

1 Assessment of Soil Erosion at a DC Park Facility Spring Valley Park NW Washington, DC Annual of this project is to provide a preliminary site inventory and assessment of soil erosion for the Spring Valley erosion. Due to its location relative to the University and small size it was determined to be an ideal

District of Columbia, University of the

351

Reactive accelerated cluster erosion (RACE) for micromachining  

NASA Astrophysics Data System (ADS)

Accelerated ionized cluster beams are used for micromachining of bulk diamond, CVD diamond films, single-crystalline silicon, or Pyrex glass, among others. Beams of clusters of CO2 or of SF6 with about 1000 molecules per unit charge are accelerated to up to 120 KeV kinetic energy for mask projective surface bombardment. Patterning is achieved via physical as well as chemical surface erosion: reactive accelerated cluster erosion (RACE). Very smooth eroded surfaces result for bulk natural diamond, silicon, metals and glass. Polycrystalline, strongly faceted CVD diamond films are effectively planarized. Submicrometer structures with adjustable wall inclination can be generated. Surface melting seems to govern the cluster impact induced nanomodifications.

Gspann, J.

1997-02-01

352

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

USGS Publications Warehouse

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 practical management solutions.

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

2014-01-01

353

Management of a large distributed control system development project  

SciTech Connect

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.

Gurd, D. P. (David P.)

2002-01-01

354

Integrated Project Scheduling and Staff Assignment with Controllable Processing Times  

PubMed Central

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

Framinan, Jose M.

2014-01-01

355

Vision-based Guidance and Control of Robots in Projective Andreas Ruf, et al  

E-print Network

-to-find" projective models of both, the stereo geometry and the robot's "projective kinematics", may be used. More in modeling multi-camera sys- tems by using algebraic projective geometry. One of the most interesting resultsVision-based Guidance and Control of Robots in Projective Space Andreas Ruf, et al GRAVIR

Paris-Sud XI, Université de

356

Forests and Soil Erosion across Europe  

NASA Astrophysics Data System (ADS)

Land use and climate change threaten the ability of Europe's forests to provide a vital service in limiting soil erosion, e.g. from forest fires and landslides. However, our ability to define the threat and to propose mitigation measures suffers from two deficiencies concerning the forest/erosion interface: 1) While there have been a considerable number of field studies of the relationship between forest cover and erosion in different parts of Europe, the data sets are scattered among research groups and a range of literature outlets. There is no comprehensive overview of the forest/erosion interface at the European scale, essential for considering regional variations and investigating the effects of future changes in land use and climate. 2) Compared with forest/water studies, we have a poorer quantitative appreciation of forest/erosion interactions. In the forest/water area it is possible to make quantitative statements such as that a 20% change in forest cover across a river catchment is needed for the effect on annual water yield to be measurable or that a forested catchment in upland UK has an annual water yield around 15% lower than an otherwise comparable grassland catchment. Comparable statements are not yet possible for forest/erosion interactions and there are uncertainties in the mathematical representation of forest/erosion interactions which limit our ability to make predictions, for example of the impact of forest loss in a given area. This presentation therefore considers the next step in improving our predictive capability. It proposes the integration of existing research and data to construct the "big picture" across Europe, i.e. erosion rates and sediment yields associated with forest cover and its loss in a range of erosion regimes (e.g. post-forest fire erosion or post-logging landslides). This would provide a basis for generalizations at the European scale. However, such an overview would not form a predictive capability. Therefore it is also necessary to identify a range of predictive methods, from empirical guidelines to computer models, which can be recommended for applications such as extrapolating from the local to the regional scale and for planning mitigation strategies. Such developments could help improve efficiency in the integrated management of forest, soil and water resources, benefit local engineering projects ranging from hazard mitigation plans to road culvert design, contribute to the implementation of the EU Water Framework Development, form a more objective basis for cost/benefit analysis of proposed management actions and help in putting a value on forest services.

Bathurst, J. C.

2012-04-01

357

Hydro-abrasive erosion: Problems and solutions  

NASA Astrophysics Data System (ADS)

The number of hydro power plants with hydro-abrasive erosion is increasing worldwide. An overall approach is needed to minimize the impact of this phenomenon. Already at the start of the planning phase an evaluation should be done to quantify the erosion and the impact on the operation. For this, the influencing parameters and their impact on the erosion have to be known. The necessary information for the evaluation comprises among others the future design, the particle parameters of the water, which will pass the turbine, and the power plant owner's framework for the future operation like availability or maximum allowable efficiency loss, before an overhaul needs to be done. Based on this evaluation of the erosion, an optimised solution can then be found, by analysing all measures in relation to investments, energy production and maintenance costs as decision parameters. Often a more erosion-resistant design, instead of choosing the turbine design with the highest efficiency, will lead to higher revenue. The paper will discuss the influencing parameters on hydro-abrasive erosion and the problems to acquire this information. There are different optimisation possibilities, which will be shown in different case studies. One key aspect to reduce the erosion and prolong the operation time of the components is to coat all relevant parts. But it is very important that this decision is taken early in the design stage, as the design has to be adapted to the requirements of the coating process. The quality of coatings and their impact on the operation will be discussed in detail in the paper as due to the non-availability of standards many questions arise in projects.

Winkler, K.

2014-12-01

358

Controls on the strength of coupling among climate, erosion, and deformation in two-sided, frictional orogenic wedges at steady state  

Microsoft Academic Search

Many important insights regarding the coupling among climate, erosion, and tectonics have come from numerical simulations using coupled tectonic and surface process models. However, analyses to date have left the strength of the coupling between climate and tectonics uncertain and many questions unanswered. We present an approximate analytical solution for two-sided orogenic wedges obeying a frictional rheology, and in a

K. X. Whipple; B. J. Meade

2004-01-01

359

Minimal Change Esophagitis: Prospective Comparison of Endoscopic and Histological Markers between Patients with Non-Erosive Reflux Disease and Normal Controls Using Magnifying Endoscopy  

Microsoft Academic Search

Introduction: More than half the patients with gastroesophageal reflux disease (GERD) show no endoscopic abnormality or minimal change esophagitis (non-erosive reflux disease, NERD). We investigated the value of endoscopic and histological markers for the prediction of NERD before and after treatment with 20 mg esomeprazole. Methods: Between July and October 2002, consecutive patients presenting for upper endoscopy were stratified into

R. Kiesslich; S. Kanzler; M. Moehler; J. Neidig; B. J. Thanka Nadar; D. Schilling; J. Burg; B. Nafe; M. F. Neurath; P. R. Galle

2004-01-01

360

Motor Controls for the NIFFTE Time Projection Chamber Positioning Stand  

NASA Astrophysics Data System (ADS)

The next generation nuclear power plants will be more efficient and produce smaller amounts of radioactive waste. Design of these new reactors is limited partially by the lack of precise neutron induced fission cross sections at certain incident neutron energies of several isotopes. In order to reduce the uncertainty of the cross sections to less than 1 percent, a Time Projection Chamber (TPC) was built by the Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) collaboration. These improvements in precision will be possible due to the TPC's ability for a full 3-D reconstruction of the fission fragment tracks. The NIFFTE TPC will be installed at Los Alamos National Lab's LANSCE facility. Thin targets will be mounted in the center of the TPC in a pressurized hydrogen gas chamber so that both hemispheres of the reaction will be covered. In this work we will discuss the control of the stepper motors that drive the positioning table of the TPC, which has all of its readout electronics attached, to be lined up with the beam. This includes both the controlling software and its graphical interface to the MIDAS online data acquisition system.

Pamplin, Daniel; Pickle, Nathan

2010-11-01

361

Calibrating thermal erosion models along an Arctic coastline  

NASA Astrophysics Data System (ADS)

Coastal erosion rates of 20-30 meters per year have been documented along Alaska’s Beaufort Sea coastline, and a number of studies suggest that erosion rates have accelerated as a result of climate change. However, a lack of direct observational evidence has limited our progress in quantifying the role of climate change on coastal erosion rates in the Arctic. In particular, while longer ice-free periods are likely to lead to both warmer surface waters and longer fetch, the relative roles of thermal and mechanical (wave) erosion in driving coastal retreat have not been comprehensively quantified. We focus on the potential magnitude of thermal erosion along a permafrost coastline in the northern National Petroleum Reserve-Alaska (NPR-A), where erosion rates have averaged 10-15 meters/year over two years of direct monitoring. We take advantage of these extraordinary rates of coastal erosion to directly observe erosion processes via time-lapse photography, while monitoring temperature, solar radiation and wind speed at the same time. These combined observations are used to calibrate models of thermal erosion. Our observations suggest that virtually all of the erosion in this setting can be explained as a purely thermal process. Coastal bluffs are first notched and then topple into the ocean, failing dominantly along ice wedges that serve as planes of weakness. Furthermore, the high ice content and the fine grain size of the coastal plain materials that comprise the bluffs appear to limit any strong negative feedback on erosion rates, since the sediments are readily dispersed on the shallow shelf. Although erosion driven purely by thermal processes may be unique to this particular coastal zone, these observations implicate a direct relationship between climatic warming and landscape change. Erosion of sandy coastlines in other parts of the NPR-A may also be ultimately controlled by thermal energy, once a thin veneer of clastic material is removed by wave action from late summer storms.

Wobus, C. W.; Anderson, R. S.; Overeem, I.; Urban, F. E.; Clow, G. D.; Stanton, T. P.

2009-12-01

362

9 CFR 54.9 - Waiver of requirements for scrapie control pilot projects.  

Code of Federal Regulations, 2013 CFR

...determination that an animal is a high-risk animal, if the scrapie control...project plan contains testing or other procedures that indicate that an animal, despite meeting the...project plan contains alternative procedures to...

2013-01-01

363

9 CFR 54.9 - Waiver of requirements for scrapie control pilot projects.  

Code of Federal Regulations, 2014 CFR

...determination that an animal is a high-risk animal, if the scrapie control...project plan contains testing or other procedures that indicate that an animal, despite meeting the...project plan contains alternative procedures to...

2014-01-01

364

9 CFR 54.9 - Waiver of requirements for scrapie control pilot projects.  

Code of Federal Regulations, 2011 CFR

...determination that an animal is a high-risk animal, if the scrapie control...project plan contains testing or other procedures that indicate that an animal, despite meeting the...project plan contains alternative procedures to...

2011-01-01

365

9 CFR 54.9 - Waiver of requirements for scrapie control pilot projects.  

Code of Federal Regulations, 2010 CFR

...determination that an animal is a high-risk animal, if the scrapie control...project plan contains testing or other procedures that indicate that an animal, despite meeting the...project plan contains alternative procedures to...

2010-01-01

366

9 CFR 54.9 - Waiver of requirements for scrapie control pilot projects.  

Code of Federal Regulations, 2012 CFR

...determination that an animal is a high-risk animal, if the scrapie control...project plan contains testing or other procedures that indicate that an animal, despite meeting the...project plan contains alternative procedures to...

2012-01-01

367

Erosion of composite ceramics  

SciTech Connect

The theoretical basis to describe solid-particle erosion of monolithic ceramics is well developed. In many cases, the models can account for the impact velocity, impact angle and erodent-size dependencies of the steady-state erosion rate. In addition, the models account for effects of materials parameters such as fracture toughness and hardness. Steady-state erosion measurements on a wide variety of composite ceramics, including SiC whisker-reinforced Al[sub 2]O[sub 3], Si[sub 3]N[sub 4] containing Si[sub 3]N[sub 4] or SiC whiskers, Y[sub 2]O[sub 3]-stabilized ZrO[sub 2] reinforced with SiC whiskers, and duplex-microstructure Si[sub 3]N[sub 4] have been reported. The theories developed for monolithic ceramics are, however, less successful in describing the results for composites.

Routbort, J.L.

1992-08-01

368

Erosion of composite ceramics  

SciTech Connect

The theoretical basis to describe solid-particle erosion of monolithic ceramics is well developed. In many cases, the models can account for the impact velocity, impact angle and erodent-size dependencies of the steady-state erosion rate. In addition, the models account for effects of materials parameters such as fracture toughness and hardness. Steady-state erosion measurements on a wide variety of composite ceramics, including SiC whisker-reinforced Al{sub 2}O{sub 3}, Si{sub 3}N{sub 4} containing Si{sub 3}N{sub 4} or SiC whiskers, Y{sub 2}O{sub 3}-stabilized ZrO{sub 2} reinforced with SiC whiskers, and duplex-microstructure Si{sub 3}N{sub 4} have been reported. The theories developed for monolithic ceramics are, however, less successful in describing the results for composites.

Routbort, J.L.

1992-08-01

369

Wind Erosion in Tithonium  

NASA Technical Reports Server (NTRS)

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

2005-01-01

370

River Flooding and Erosion  

NSDL National Science Digital Library

Students are presented with a real-life problem of flooding and erosion in the town of Simonton. They must use historical dischage data to determine the future risk of flooding. They must also use historical map data to asses the risk of future losses due to erosion. Using these data, they must dertermine the feasibility of levee systems proposed by the Corp of Engineers. Lastly, they must discuss their assumption and possible sources of error. Has minimal/no quantitative component Uses geophysics to solve problems in other fields

Bill Dupre

371

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)

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"

Cerdà, A.

2009-04-01

372

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)

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 purple willow (Salix purpurea). Only the 25% of the interventions was accomplished by the use of secondary plant species, as tamarisk (Tamarix spp.,) blackthorn (Prunus spinosa) , whitethorn (Crataegus spp.), sea-buckthorn (Hipphopae rhamnoides), wild pear (Pyrus pyraster), cottonwood (Populus nigra), eglantine (Rosa spp.), goat-willow (Salix caprea) and cornel (Cornus sanguinea). Better results were achieved with Spanish Broom, a very rural plant that can effectively colonise even poor soils like badlands; as a matter of fact, more than the 75% of the interventions had positive outcomes The efficacy of the consolidation work by the presence of living structures point out an increase of the stability of those interventions older than 4 years, with taking root species present from 54% to 78%. So far, the construction and the reliability of the works have been monitored, in order to capture critical aspects for the success of works and to build a geo-referenced data base of the existing works and their status.

Selli, Lavinia; Cavazza, Claudio; Pavanelli, Donatella

2013-04-01

373

40 CFR 93.125 - Enforceability of design concept and scope and project-level mitigation and control measures.  

Code of Federal Regulations, 2010 CFR

...Enforceability of design concept and scope and project-level mitigation and control measures...of Transportation Plans, Programs, and Projects Developed, Funded or Approved Under...Enforceability of design concept and scope and project-level mitigation and control...

2010-07-01

374

40 CFR 93.125 - Enforceability of design concept and scope and project-level mitigation and control measures.  

Code of Federal Regulations, 2011 CFR

...Enforceability of design concept and scope and project-level mitigation and control measures...of Transportation Plans, Programs, and Projects Developed, Funded or Approved Under...Enforceability of design concept and scope and project-level mitigation and control...

2011-07-01

375

40 CFR 93.125 - Enforceability of design concept and scope and project-level mitigation and control measures.  

Code of Federal Regulations, 2013 CFR

...Enforceability of design concept and scope and project-level mitigation and control measures...of Transportation Plans, Programs, and Projects Developed, Funded or Approved Under...Enforceability of design concept and scope and project-level mitigation and control...

2013-07-01

376

40 CFR 93.125 - Enforceability of design concept and scope and project-level mitigation and control measures.  

Code of Federal Regulations, 2012 CFR

...Enforceability of design concept and scope and project-level mitigation and control measures...of Transportation Plans, Programs, and Projects Developed, Funded or Approved Under...Enforceability of design concept and scope and project-level mitigation and control...

2012-07-01

377

40 CFR 93.125 - Enforceability of design concept and scope and project-level mitigation and control measures.  

Code of Federal Regulations, 2014 CFR

...Enforceability of design concept and scope and project-level mitigation and control measures...of Transportation Plans, Programs, and Projects Developed, Funded or Approved Under...Enforceability of design concept and scope and project-level mitigation and control...

2014-07-01

378

Erosion modelling towards, and sediment transport modelling in unnavigable watercourses in Flanders, Belgium  

NASA Astrophysics Data System (ADS)

Antea Group and KULeuven were awarded a project in Flanders to identify the regions exporting high sediment loads to unnavigable watercourses and the sedimentation zones within them. Two types of models are applied: hydrological sediment export models (SEM) and hydraulic sediment transport models (STM). The influence of erosion control measures on sediment export as well as river engineering measures needs to be taken into account. A concept will be developed to connect the SEM and STM, enabling the sediment to be routed from upstream to the sedimentation zones. Results of the study will be used by the Flemish government to plan erosion control measures, estimate future sedimentation volumes, steer sedimentation and optimize river engineering and dredging works. Finally, model results could also be used to obtain better insights to the re-suspension risks of contaminated sediment in watercourses.

Ferket, B.; Van De Broek, M.; Van Hoestenberghe, T.; Degerickx, J.; De Sutter, R.; Govers, G.; Dezillie, N.; Deproost, P.

2015-03-01

379

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

PubMed

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. PMID:24500268

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

2014-03-01

380

Tooth Abrasion and Tooth Erosion  

MedlinePLUS

... problem is called acid reflux. People with the eating disorder bulimia can get tooth erosion because of repeated vomiting. Even the chlorine and other chemicals in a swimming pool can cause erosion over time. Symptoms Toothbrush abrasion causes V- ...

381

External Resource: Weathering and Erosion  

NSDL National Science Digital Library

This activity includes background information about weathering, as well as simple demonstrations/activities to model how weather conditions contribute to weathering and erosion. Topics include: chemical weathering, dunes, erosion, floods, glaciers, physi

1900-01-01

382

External Resource: Erosion and Weathering  

NSDL National Science Digital Library

This is a Teachers' Domain photo essay with images that depict surface features on Earth that result from weathering and erosion, as well as measures designed to mitigate their unwanted effects. Topics: weathering, erosion, sediments, dunes, deltas, glaci

1900-01-01

383

Erosion on a line  

NASA Astrophysics Data System (ADS)

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.

Willett, Sean D.

2010-03-01

384

Erosion of dust aggregates  

E-print Network

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 m/s and above. Though fractal aggregates as ...

Seizinger, Alexander; Kley, Wilhelm

2013-01-01

385

EROSION OF EARTH SPILLWAYS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Natural Resources Conservation Service (NRCS) Water Resources Site Analyses computer program, Sites, contains a vegetated earth spillway erosion prediction model. Since the beta release of Sites in 1996, the program has been successfully applied in the analysis of a number of existing spillways...

386

SOIL EROSION IN TEPETATES  

Technology Transfer Automated Retrieval System (TEKTRAN)

The valley of Mexico is one of the most populous places on earth. Although rainfall is low and infrequent, there is considerable soil erosion by water and land destruction due to high intensity storms, steep slopes, highly erodible volcanic derived soils and disturbance by man. The disturbance by ...

387

Soil Erosion by Water  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soil erosion by water, the wearing away of the earth's surface by the forces of water and gravity, consists of rock or soil particle dislodgement, entrainment, transport, and deposition. This sequence of events occurs over a wide range of temporal and spatial scales, from raindrop splash moving par...

388

Recurrent Corneal Erosion Syndrome  

Microsoft Academic Search

Recurrent corneal erosion syndrome is a chronic relapsing disease of the corneal epithelium characterized by repeated episodes of sudden onset of pain usually at night or upon first awakening, accompanied by redness, photophobia, and watering of the eyes. Individual episodes may vary in severity and duration. These symptoms are related to corneal deepithelialization in an area in which the epithelium

Sujata Das; Berthold Seitz

2008-01-01

389

Role of projection in the control of bird flocks  

PubMed Central

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

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

2014-01-01

390

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

NASA Technical Reports Server (NTRS)

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.

Hayhurst, Kelly J. (Editor)

2008-01-01

391

Erosion and Deposition in Turbomachinery  

Microsoft Academic Search

This paper presents a review of erosion and deposition research in turbomachines and the associated degrada- tion in engine performance caused by particulate matter ingestion. Parameters affecting surface material losses as a result of erosion and development of experimental and analytical approaches to predict flowpath erosion and deposition are discussed. Tests results that quantify the effects of temperature, impact particle

A. Hamed; W. C. Tabakoff; R. V. Wenglarz

2006-01-01

392

Soil formation in response to perturbed erosion rates  

NASA Astrophysics Data System (ADS)

Time is recognized as one of the soil forming factors. In upland, sloping landscapes time is controlled by erosion rates. These erosion rates may be forced by climate, tectonics, and increasingly anthropogenic disturbance. Perturbations to erosion rates alter the exposure of near surface material to both physical and chemical weathering, which can influence water retention, plant growth and sediment transport. All of these can feed back into further perturbation of erosion rates. Here we present field data, topographic analysis and numerical modelling from a field site in the Sierra Nevada of California where we have attempted to examine soil formation across a range of erosion rates, and determine their influence on soil particle size, geochemistry and plant life, as well as the geomorphic signature of overland flow. Erosion rates have strong impact on soils, leading to coarser soils that support less biomass when erosion rates are high and clay rich soils with higher biomass when erosion rates are low. Erosion rates also appear to influence the dissection of the landscape by channels, which we quantify using high resolution topographic analysis.

Mudd, Simon; Milodowski, David; Yoo, Kyungsoo; Gabet, Emmanuel; Weinman, Beth; Attal, Mikael; Clubb, Fiona

2014-05-01

393

Projects for M.Sc. thesis Modeling and control of complex systems  

E-print Network

- PnP control for microgrids Renewable resources · Photovoltaic arrays · Wind energy · Micro turbines Advantages · Clean electricity · Distributed Generation (DG) units #12;Project 1 - PnP control for microgrids

Ferrari-Trecate, Giancarlo

394

Successful Pursuit of Small Electrical and Controls Projects by a Small Civil Engineering Firm  

E-print Network

This paper determines how a small, primarily civil engineering firm possessing an electrical and controls group can successfully pursue small electrical and controls projects issued by local electrical generation utilities. Not only...

Gates, Craig

2008-07-25

395

78 FR 64909 - Southwestern Region: Invasive Plant Control Project, Carson and Santa Fe National Forests, New...  

Federal Register 2010, 2011, 2012, 2013, 2014

...and correct deficiencies identified in the 2005 Invasive Plant Control Project Final Environmental Impact Statement...action, which includes the use of herbicides to control invasive species, remains the preferred alternative. The...

2013-10-30

396

Project Controls to Minimize Cost and Schedule Overruns: A Model, Research Agenda, and Initial Results  

E-print Network

1 of 27 Project Controls to Minimize Cost and Schedule Overruns: A Model, Research Agenda been successfully applied to the study of projects for many years. While this modeling has clearly defined the structures which create project dynamics, it has been less helpful in providing explicit

Ford, David N.

397

The Role of Preferential Flow Through Soil-Pipes on Ephemeral Gully Erosion  

Technology Transfer Automated Retrieval System (TEKTRAN)

Estimates by the USDA for 17 States suggest that ephemeral gully erosion ranges from 18 to 73% of the total erosion with a median of 35%. Concentrated flow is generally considered the controlling process and subsurface flow is often overlooked. Pipe-erosion may occur with no visible evidence until p...

398

The Role of Vegetation for Reducing Wind Erosion on Military Lands  

Technology Transfer Automated Retrieval System (TEKTRAN)

It is well known that vegetation (kind, amount, position) reduces wind erosion. Control and prediction of wind erosion requires knowledge of the effectiveness of surface vegetation. Knowing the role of vegetation in reducing wind erosion enhances effective management of military lands. The purpos...

399

Sustainable farm income in the presence of soil erosion: an agricultural Hartwick rule  

Microsoft Academic Search

Soil erosion is a physical and economic problem of natural capital degradation. Even along an intertemporally efficient trajectory, one can have in a loss of soil fertility and a continuous decline of agricultural net revenue. Moreover, soil erosion is a major source of surface water pollution in rural areas. Erosion control is thus a challenge for sustainable resource management and

Werner Hediger

2003-01-01

400

Mechanical Engineering Design Project report: Enabler control systems  

NASA Technical Reports Server (NTRS)

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.

Cullen, Christian; Delvecchio, Dave; Scarborough, Alan; Havics, Andrew A.

1992-01-01

401

OPERATION OF THE OLD RIVER CONTROL PROJECT, ATCHAFALAYA BASIN: AN EVALUATION FROM MULTIUSE MANAGEMENT STANDPOINT  

EPA Science Inventory

This report evaluated from a multiuse management standpoint the operation of the Old River Control Project. It was found that limiting diversions to the extent presently being considered by the Old River Control Project would effectively remove those wetlands that are presently f...

402

Know Your Enemy: The Use of Molecular Ecology in the Onopordum Biological Control Project  

Microsoft Academic Search

Experience has repeatedly shown that accurate identification of the target weed(s) for a biological control project is critical to the success of a biological control project. This is particularly true where the weed may comprise different biotypes or be part of a species complex, where hybridisation is suspected or where the agent - host plant relationship is very tight. Molecular

P. C. O'HANLON; D. T. BRIESE; R. PEAKALL

403

Soil erosion and agricultural sustainability  

PubMed Central

Data drawn from a global compilation of studies quantitatively confirm the long-articulated contention that erosion rates from conventionally plowed agricultural fields average 1–2 orders of magnitude greater than rates of soil production, erosion under native vegetation, and long-term geological erosion. The general equivalence of the latter indicates that, considered globally, hillslope soil production and erosion evolve to balance geologic and climate forcing, whereas conventional plow-based agriculture increases erosion rates enough to prove unsustainable. In contrast to how net soil erosion rates in conventionally plowed fields (?1 mm/yr) can erode through a typical hillslope soil profile over time scales comparable to the longevity of major civilizations, no-till agriculture produces erosion rates much closer to soil production rates and therefore could provide a foundation for sustainable agriculture. PMID:17686990

Montgomery, David R.

2007-01-01

404

Erosive burning. Modeling problems  

Microsoft Academic Search

Existing models for the erosive burning of homogeneous energetic materials ignore the fact that the burning regime can be\\u000a changed radically by exposure to a hot gas blowing over the burning surface. In other words, transition can occur from the\\u000a gasification regime at very high blowing rates (where the burning rate is determined primarily by the heat transfer from the

L. K. Gusachenko; V. E. Zarko

2007-01-01

405

Actinides, accelerators and erosion  

NASA Astrophysics Data System (ADS)

Fallout isotopes can be used as artificial tracers of soil erosion and sediment accumulation. The most commonly used isotope to date has been 137Cs. Concentrations of 137Cs are, however, significantly lower in the Southern Hemisphere, and furthermore have now declined to 35% of original values due to radioactive decay. As a consequence the future utility of 137Cs is limited in Australia, with many erosion applications becoming untenable within the next 20 years, and there is a need to replace it with another tracer. Plutonium could fill this role, and has the advantages that there were six times as many atoms of Pu as of 137Cs in fallout, and any loss to decay has been negligible due to the long half-lives of the plutonium isotopes. Uranium-236 is another long-lived fallout isotope with significant potential for exploitation as a tracer of soil and sediment movement. Uranium is expected to be more mobile in soils than plutonium (or caesium), and hence the 236U/Pu ratio will vary with soil depth, and so could provide an independent measure of the amount of soil loss. In this paper we discuss accelerator based ultra-sensitive measurements of plutonium and 236U isotopes and their advantages over 137Cs as tracers of soil erosion and sediment movement.

Tims, S. G.; Fifield, L. K.

2012-10-01

406

Computerized adaptive control weld skate with CCTV weld guidance project  

NASA Technical Reports Server (NTRS)

This report summarizes progress of the automatic computerized weld skate development portion of the Computerized Weld Skate with Closed Circuit Television (CCTV) Arc Guidance Project. The main goal of the project is to develop an automatic welding skate demonstration model equipped with CCTV weld guidance. The three main goals of the overall project are to: (1) develop a demonstration model computerized weld skate system, (2) develop a demonstration model automatic CCTV guidance system, and (3) integrate the two systems into a demonstration model of computerized weld skate with CCTV weld guidance for welding contoured parts.

Wall, W. A.

1976-01-01

407

Spent Nuclear Fuel Project document control and Records Management Program Description  

SciTech Connect

The Spent Nuclear Fuel (SNF) Project document control and records management program, as defined within this document, is based on a broad spectrum of regulatory requirements, Department of Energy (DOE) and Project Hanford and SNF Project-specific direction and guidance. The SNF Project Execution Plan, HNF-3552, requires the control of documents and management of records under the auspices of configuration control, conduct of operations, training, quality assurance, work control, records management, data management, engineering and design control, operational readiness review, and project management and turnover. Implementation of the controls, systems, and processes necessary to ensure compliance with applicable requirements is facilitated through plans, directives, and procedures within the Project Hanford Management System (PHMS) and the SNF Project internal technical and administrative procedures systems. The documents cited within this document are those which directly establish or define the SNF Project document control and records management program. There are many peripheral documents that establish requirements and provide direction pertinent to managing specific types of documents that, for the sake of brevity and clarity, are not cited within this document.

MARTIN, B.M.

2000-05-18

408

The relationship of control and learning to project performance  

Microsoft Academic Search

Management controls can be divided into two types that can have opposite effects on organizational learning: behavioral controls, which promote efficiency but also stifle much of the learning opportunity, and outcome controls, which foster interaction among stakeholders can add to the learning environment. This article reports on a study that confirms these observations and explores the nature of their direct

Gary Klein; Peggy M. Beranek; Ben Martz; James J. Jiang

2006-01-01

409

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...

410

Estimation of regional differences in wind erosion sensitivity in Hungary  

NASA Astrophysics Data System (ADS)

In Hungary, wind erosion is one of the most serious natural hazards. Spatial and temporal variation in the factors that determine the location and intensity of wind erosion damage are not well known, nor are the regional and local sensitivities to erosion. Because of methodological challenges, no multi-factor, regional wind erosion sensitivity map is available for Hungary. The aim of this study was to develop a method to estimate the regional differences in wind erosion sensitivity and exposure in Hungary. Wind erosion sensitivity was modelled using the key factors of soil sensitivity, vegetation cover and wind erodibility as proxies. These factors were first estimated separately by factor sensitivity maps and later combined by fuzzy logic into a regional-scale wind erosion sensitivity map. Large areas were evaluated by using publicly available data sets of remotely sensed vegetation information, soil maps and meteorological data on wind speed. The resulting estimates were verified by field studies and examining the economic losses from wind erosion as compensated by the state insurance company. The spatial resolution of the resulting sensitivity map is suitable for regional applications, as identifying sensitive areas is the foundation for diverse land development control measures and implementing management activities.

Mez?si, G.; Blanka, V.; Bata, T.; Kovács, F.; Meyer, B.

2015-01-01

411

Eolian erosion of the Martian surface. I - Erosion rate similitude  

NASA Technical Reports Server (NTRS)

A similitude parameter is derived which is based on theoretical considerations of erosion due to sand in saltation. This parameter has been used to correlate wind tunnel experiments of particle flow over model craters. The characteristics of the flow field in the vicinity and downstream of a crater are discussed and it is shown that erosion is initiated in areas lying under a pair of trailing vortices. The erosion rate parameter is used to calculate erosion rates on Mars, reported in Part 2, to be published later.

Iversen, J. D.; White, B. R.; Greeley, R.; Pollack, J. B.

1975-01-01

412

Soil erosion after forest fires in the Valencia region  

NASA Astrophysics Data System (ADS)

Soil erosion after forest fire is triggered by the lack of vegetation cover and the degradation of the physical, biological and chemical properties (Martí et al., 2012; Fernández et al., 2012; Guénon, 2013). Valencia region belongs to the west Mediterranean basin ("Csa", Köppen climate classification), with drought summer periods that enhance forest fire risk. The characteristics of the climate, lithology and land use history makes this region more vulnerable to soil erosion. In this area, fire recurrence is being increased since late 50s (Pausas, 2004) and post-fire erosion studies became more popular from 80's until nowadays (Cerdá and Mataix-Solera, 2009). Research in Valencia region has contributed significantly to a better understanding of the effect of spatial and temporal scale on runoff and sediment yield measurements. The main achievements concerns: a) direct measurement of erosion rates under a wide range of methodologies (natural vs simulated rainfall, open vs closed plots); from micro- to meso-plot and catchment scale in single (Rubio et al., 1994; Cerdà et al., 1995; Cerdà 1998a; 1998b; Llovet et al., 1998; Cerdà, 2001; Calvo-Cases et al., 2003; Andreu et al., 2001; Mayor et al., 2007; Cerdà and Doerr, 2008) and multiples fires (Campo et al., 2006; González-Pelayo et al., 2010a). Changes in soil properties (Sanroque et al., 1985; Rubio et al., 1997; Boix-Fayós, 1997; Gimeno-Garcia et al., 2000; Guerrero et al., 2001; Mataix-Solera et al., 2004; González-Pelayo et al., 2006; Arcenegui et al., 2008; Campo et al., 2008; Bodí et al., 2012), in post-fire vegetation patterns (Gimeno-García et al., 2007) and, studies on mitigation strategies (Bautista et al., 1996; Abad et al., 2000). b) Progress to understanding post-fire erosion mechanism and sediment movement (Boix-Fayós et al., 2005) by definition of thresholds for sediment losses; fire severity, slope angle, bedrock, rain characteristics, vegetation pattern and ecosystem resilience (Mayor 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 31, 219-236. Boix-Fayos, C., Martínez-Mena, M., Calvo-Cases, A., Castillo, V.M., Albad

González-Pelayo, Óscar; Keizer, Jan Jacob; Cerdà, Artemi

2014-05-01

413

South Polar Erosion  

NASA Technical Reports Server (NTRS)

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.

2004-01-01

414

Wind Erosion in Aeolis  

NASA Technical Reports Server (NTRS)

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.

2004-01-01

415

Galveston Island and erosion  

E-print Network

directly in front of many of the developed areas appeared to be relatively successful at keeping erosion to a minimum. September 23, 1980 to September 22, 1983 Two tropical storms, Jeanne and Chris, affected the Texas Coast along with Hurricane Alicia.... VITA 73 74 80 85 97 101 115 LIST OF TABLES Table Page 1. Ai rphoto Scale Determination with the Aid of a Base Map . . 16 2. Actual-vs-l4easured Photo Scale and Resulting Error 3. Tropical Cyclones Affecting the Texas Coast from 1952...

Bolleter, Jim Mason

1985-01-01

416

Comparison of Erosion Rates Estimated by Sediment Budget Techniques and Suspended Sediment Monitoring and Regulatory Implications  

NASA Astrophysics Data System (ADS)

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 spanned the winter runoff seasons of Water Years 2006 and 2007. These were unusually wet and dry years, respectively, providing perspective on the range of measured sediment yield in relation to sediment budget estimates. The measured suspended sediment yields were substantially lower than predicted by sediment budget methods. Variation in geomorphic processes over time and space and methodological problems of sediment budgets may be responsible for these apparent discrepancies. The implications for water quality policy are discussed.

O'Connor, M.; Eads, R.

2007-12-01

417

Critical issues in process control system security : DHS spares project.  

SciTech Connect

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.

Hernandez, Jacquelynne; McIntyre, Annie; Henrie, Morgan

2010-10-01

418

Temperature Control System with Multi-Closed Loops for Lithography Projection Lens  

Microsoft Academic Search

Image quality is one of the most important specifications of optical lithography tool and is affected notably by temperature, vibration, and contamination of projection lens(PL). Traditional method of local temperature control is easier to introduce vibration and contamination, so temperature control system with multi-closed loops is developed to control the temperature inside the PL, and to isolate the influence of

NIE Hongfei; LI Xiaoping; HE Yan

419

Erosive tooth wear in children.  

PubMed

Erosive tooth wear in children is a common condition. Besides the anatomical differences between deciduous and permanent teeth, additional histological differences may influence their susceptibility to dissolution. Considering laboratory studies alone, it is not clear whether deciduous teeth are more liable to erosive wear than permanent teeth. However, results from epidemiological studies imply that the primary dentition is less wear resistant than permanent teeth, possibly due to the overlapping of erosion with mechanical forces (like attrition or abrasion). Although low severity of tooth wear in children does not cause a significant impact on their quality of life, early erosive damage to their permanent teeth may compromise their dentition for their entire lifetime and require extensive restorative procedures. Therefore, early diagnosis of erosive wear and adequate preventive measures are important. Knowledge on the aetiological factors of erosive wear is a prerequisite for preventive strategies. Like in adults, extrinsic and intrinsic factors, or a combination of them, are possible reasons for erosive tooth wear in children and adolescents. Several factors directly related to erosive tooth wear in children are presently discussed, such as socio-economic aspects, gastroesophageal reflux or vomiting, and intake of some medicaments, as well as behavioural factors such as unusual eating and drinking habits. Additionally, frequent and excessive consumption of erosive foodstuffs and drinks are of importance. PMID:24993274

Carvalho, Thiago S; Lussi, Adrian; Jaeggi, Thomas; Gambon, Dein L

2014-01-01

420

Towards Greater Learner Control: Web Supported Project-Based Learning  

ERIC Educational Resources Information Center

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…

Guthrie, Cameron

2010-01-01

421

Skills Conversion Project, Chapter 8, Pollution Control. Final Report.  

ERIC Educational Resources Information Center

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…

National Society of Professional Engineers, Washington, DC.

422

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)

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 Expert Choice showing the AHP results. A brief schema of the actions recommended for each of the six different sub zones is discussed.

Grau, J. B.; Antón, J. M.; Tarquis, A. M.; Colombo, F.; de Los Ríos, L.; Cisneros, J. M.

2010-11-01

423

Soil erosion dynamics through multiple rainfall events  

NASA Astrophysics Data System (ADS)

The dynamics of soil erosion during repeated rainfall events was studied, in particular focusing on the effect of initial soil characteristics and surface shielding by rock fragments. A sequence of four 2-h erosive events (named H7- E1, E2, and E3, respectively) separated by 22 h of air drying was performed using a 6-m long laboratory rainfall simulator and erosion flume. A loamy soil was used in all experiments. The surface was hand cultivated before the first event. Rainfall intensities of 28, 74, 74 and 28 mm h-1 were considered. The erosion flume was divided into two identical 1-m wide sections, one of which was covered with rock fragments. Results showed that steady-state behavior is mainly controlled by the rainfall intensity. Soil initial conditions, in particular whether steady state was reached during the previous event, control the sediment yields during the initial transient phase of the erosive event. If quasi-steady behavior was reached for a particular sediment size class, that class's effluent concentration peaked rapidly in the next rainfall event, then declined gradually to its steady-state value. In contrast, if the sediment concentrations were still varying at the end of a rainfall event, the subsequent event produced effluent concentrations that increased gradually to steady state. The surface rock fragments reduced the time needed to achieve the steady state, compared to bare soil conditions. The Hairsine and Rose erosion model was adopted to analyze the measured sediment delivery. A satisfactory comparison was observed for the two experiments in which the soil was only slightly modified by raindrop impact (H7-E3 and H7-E4). On the contrary, the model could not predict accurately the erosion yields of the first two rainfall events (H7-E1 and H7-E2), during which the soil surface was heavily compacted and a surface seal developed. Furthermore, the model could not reproduce in detail the sediment concentrations of the individual size classes, when partially steady conditions were obtained during the event.

Jomaa, S.; Barry, D. A.; Brovelli, A.; Heng, B. P.; Parlange, J.

2012-12-01

424

Abstracting human control strategy in projecting light source  

Microsoft Academic Search

In this paper, we present a method for modeling human strategies in controlling a light source in a dynamic environment. In order to illustrate the procedure and method, we take a simple example of how to control a light source so as to avoid a shadow and to maintain appropriate illumination conditions on the target area of attention. This work

Yangsheng Xu; Jiong Zhang

2001-01-01

425

Assessment of Rainfall, Erosivity, Runoff and Erosion in the Area  

E-print Network

of the road is over grazed public Maasai land, susceptible to erosion. 1 Centre for Development loss through runoff and erosion on over grazed areas. Intensification in land use (due to an increase of the road is private land and does hardly suffer of soil loss and land degradation whilst the other side

Richner, Heinz

426

Using 137Cs measurements to quantify soil erosion and redistribution rates for areas under different land use in the Upper Kaleya River basin, southern Zambia  

Microsoft Academic Search

Although soil erosion is a serious environmental problem in many African countries, its assessment using traditional techniques is hampered by a range of problems. Reliable information on soil erosion rates is, nevertheless, an essential prerequisite for the design of targeted erosion and sediment control strategies. This contribution reports the use of 137Cs measurements to quantify medium-term (?40 years) soil erosion

A. L Collins; D. E Walling; H. M Sichingabula; G. J. L Leeks

2001-01-01

427

Integrated Resilient Aircraft Control Project Full Scale Flight Validation  

NASA Technical Reports Server (NTRS)

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.

Bosworth, John T.

2009-01-01

428

The United States Department Of Agriculture Northeast Area-wide Tick Control Project: history and protocol.  

PubMed

The Northeast Area-wide Tick Control Project (NEATCP) was funded by the United States Department of Agriculture (USDA) as a large-scale cooperative demonstration project of the USDA-Agricultural Research Service (ARS)-patented 4-Poster tick control technology (Pound et al. 1994) involving the USDA-ARS and a consortium of universities, state agencies, and a consulting firm at research locations in the five states of Connecticut (CT), Maryland (MD), New Jersey (NJ), New York (NY), and Rhode Island (RI). The stated objective of the project was "A community-based field trial of ARS-patented tick control technology designed to reduce the risk of Lyme disease in northeastern states." Here we relate the rationale and history of the technology, a chronological listing of events leading to implementation of the project, the original protocol for selecting treatment, and control sites, and protocols for deployment of treatments, sampling, assays, data analyses, and estimates of efficacy. PMID:19650730

Pound, Joe Mathews; Miller, John Allen; George, John E; Fish, Durland

2009-08-01

429

9 CFR 79.7 - Waiver of requirements for scrapie control pilot projects.  

Code of Federal Regulations, 2011 CFR

...DEPARTMENT OF AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS SCRAPIE IN SHEEP AND GOATS § 79.7 Waiver of requirements for scrapie control pilot projects. (a) The Administrator may waive the...

2011-01-01

430

9 CFR 79.7 - Waiver of requirements for scrapie control pilot projects.  

Code of Federal Regulations, 2014 CFR

...DEPARTMENT OF AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS SCRAPIE IN SHEEP AND GOATS § 79.7 Waiver of requirements for scrapie control pilot projects. (a) The Administrator may waive the...

2014-01-01

431

9 CFR 79.7 - Waiver of requirements for scrapie control pilot projects.  

Code of Federal Regulations, 2013 CFR

...DEPARTMENT OF AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS SCRAPIE IN SHEEP AND GOATS § 79.7 Waiver of requirements for scrapie control pilot projects. (a) The Administrator may waive the...

2013-01-01

432

9 CFR 79.7 - Waiver of requirements for scrapie control pilot projects.  

Code of Federal Regulations, 2012 CFR

...DEPARTMENT OF AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS SCRAPIE IN SHEEP AND GOATS § 79.7 Waiver of requirements for scrapie control pilot projects. (a) The Administrator may waive the...

2012-01-01

433

9 CFR 79.7 - Waiver of requirements for scrapie control pilot projects.  

Code of Federal Regulations, 2010 CFR

...DEPARTMENT OF AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS SCRAPIE IN SHEEP AND GOATS § 79.7 Waiver of requirements for scrapie control pilot projects. (a) The Administrator may waive the...

2010-01-01

434

Cooperative project scheduling with controllable processing times: a game theory framework  

E-print Network

competencies and have to collaborate together for supply- ing a product or a service to a customerCooperative project scheduling with controllable processing times: a game theory framework Cyril-money. For per- forming the project, actors have to collaborate with each other intending to satisfy a desired

Briand, Cyril

435

RIPARIAN AND RELATED VALUES ASSOCIATED WITH FLOOD CONTROL PROJECT ALTERNATIVES AT WILDCAT AND SAN  

E-print Network

RIPARIAN AND RELATED VALUES ASSOCIATED WITH FLOOD CONTROL PROJECT ALTERNATIVES AT WILDCAT AND SAN PABLO CREEKS1 Philip A. Meyer 2 1 Presented at the California Riparian Systems Conference; September 22 will consider Riparian benefits from alternative project designs at Wildcat and San Pablo Creeks. Particular

Standiford, Richard B.

436

Control of visually guided behavior by distinct populations of spinal projection neurons  

Microsoft Academic Search

A basic question in the field of motor control is how different actions are represented by activity in spinal projection neurons. We used a new behavioral assay to identify visual stimuli that specifically drive basic motor patterns in zebrafish. These stimuli evoked consistent patterns of neural activity in the neurons projecting to the spinal cord, which we could map throughout

Adam R Kampff; Kristen E Severi; Johann H Bollmann; Florian Engert; Michael B Orger

2008-01-01

437

Design Project on Controlled-Release Drug Delivery Devices: Implementation, Management, and Learning Experiences  

ERIC Educational Resources Information Center

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…

Xu, Qingxing; Liang, Youyun; Tong, Yen Wah; Wang, Chi-Hwa

2010-01-01

438

Application of best practicable technology in air pollution control for the Syncrude project  

Microsoft Academic Search

For technology to be deemed the best practical technology, there are 3 fundamental requirements: (1) environmental need; (2) demonstrated technological and commercial feasibility; and (3) acceptable overall project economics including consideration of energy and environmental costs. By reviewing the air pollution control facilities in the Syncrude project against these criteria for the best practical technology, it can be demonstrated that

Goforth

1977-01-01

439

Does vegetation prevent wave erosion of salt marsh edges?  

PubMed Central

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

Feagin, R. A.; Lozada-Bernard, S. M.; Ravens, T. M.; Möller, I.; Yeager, K. M.; Baird, A. H.

2009-01-01

440

Soil erosion and sediment yield prediction on catchment and regional scale using a process based simulation model  

NASA Astrophysics Data System (ADS)

The prevention of erosion is one of the main issues in the EU-Water Framework Directive (WFD) and the European Agricultural Fund for Rural Development (EAFRD). Planning and dimensioning of soil conservation measures require reliable and detailed information on the temporal and spatial distribution of soil detachment, soil transport and deposition. Soil erosion models are increasingly used, in order to simulate the physical processes involved and to predict the effects of soil erosion control measures. In this study the EROSION 3D simulation model is used for surveying soil erosion and deposition on the catchment scale covering the entire state of Saxony/Germany (18.500 km²). EROSION 3D is a distributed, extensively validated GIS based soil loss and deposition model including sediment delivery to surface water bodies. However, the application of the model for an entire state is a new challenge, because of the enormous data requirements and complex data processing operations prior to simulation. In this context the study includes the compilation, validation and generalisation of existing land use and soil data in order to generate a consistent EROSION 3D input dataset for the entire state of Saxony. As a part of this process the interface software DPROC allows to transfer the original soil and land use data into model specific data. The project aims to extend the interface software DPROC by an interactive GIS-component which enables the user to select arbitrary hydrological watersheds including the related soil and land use data. Based on these data DPROC automatically creates the according EROSION 3D input files using a relational database of primary data and model specific data. DPROC uses parameter transfer tables in order to specify the relationship between primary soil and land use data and model specific data. This combined methodology provides different risk assessment maps for certain demands on the regional scale of a Federal State. Besides soil loss and sediment transport sediment pass over points into surface water bodies and particle enrichment can be simulated using the EROSION 3D model. Thus the estimation of particle bound nutrient and pollutant inputs into surface water bodies according to the WFD demands is possible. The study ended up in a user-friendly, timesaving and improved software package for the simulation of soil loss and deposition on a regional scale providing essential information for the planning of soil and water conservation measures particularly under consideration of expected land use and climate changes.

Schindewolf, Marcus; Schmidt, Jürgen

2010-05-01