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1

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

2

Lincoln Park Shoreline Erosion Control Project, Seattle, Washington: Operation and Maintenance Manual.  

National Technical Information Service (NTIS)

The purpose of this manual is to present information on project operation and maintenance (OM) for compliance with Federal regulations. Shoreline erosion control features at Lincoln Park, Seattle, Washington, were constructed in 1988 under the River and H...

1990-01-01

3

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

National Technical Information Service (NTIS)

The purpose of monitoring the Demonstration Erosion Control (DEC) Project is to evaluate and document watershed response to the implemented DEC Project. Documentation of watershed responses to DEC Project features will allow the participating agencies a u...

D. D. Abrams S. Sutton

1993-01-01

4

EROSION MECHANICAL CONTROL 1662  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soil erosion is a naturally occurring process. Accelerated erosion is a problem common to agriculture, mining, and construction wherever natural cover is reduced and soil is left unprotected. Mechanical erosion control measures are implemented to minimize onsite and offsite impacts of these activiti...

5

Emergency wind erosion control  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

6

Artificial Seaweed for Shoreline Erosion Control.  

National Technical Information Service (NTIS)

Over the last few years, artificial seaweed has been loudly hailed as a cure for oceanfront shoreline erosion control problems. The paper summarizes the history, theory and actual documented results of erosion control projects using artificial seaweed.

S. Rogers

1986-01-01

7

Fill Slope Erosion Control I-70-Straight Creek Corridor Project I-70-3(99).  

National Technical Information Service (NTIS)

The report documents the performance to date of the various features installed in test sections to control sedimentation of Straight Creek from erosion associated primarily with the fill slopes of I-70 along the seven mile corridor. Recommendations are al...

R. F. LaForce

1983-01-01

8

Controlled ultrasonic tissue erosion  

NASA Astrophysics Data System (ADS)

Controlled ultrasonic tissue erosion has many clinical applications, including the placement of very precise sharply defined perforations in biological interfaces and membranes with focused ultrasound. With carefully chosen acoustic parameters, tissue can be rapidly eroded away at a constant etching rate. The maximum erosion rate for minimal propagated energy is obtained by using very short high intensity pulses. The etching rate is higher with shorter pulse durations. For short pulses less than 10 cycles of the drive frequency, an optimum pulse repetition rate exists which maximizes the etching rate. Higher gas saturation in the surrounding medium reduces the etching rate and reduces the spatial sharpness of the holes produced. Most of the erosion appears to be produced in the first several cycles of the therapy pulse. For example, a series of short (about 3 cycles) focused pulses of 2100 W/cm2 (Isppa) at 788 kHz can erode a very well defined 2 mm diameter hole in a 1 mm thick sample of fresh pork atrial posterior wall in about 1 min at the optimum pulse repetition rate (about 18 kHz). Controlled ultrasonic tissue erosion may provide an effective image guided noninvasive tool in treatment of neonatal patients with hypoplastic left heart syndrome. Without the mixing of oxygenated blood across perforations placed in the atrial septum, these infants do not survive.

Cain, Charles

2003-04-01

9

Market Analysis of Erosion Control Mats.  

National Technical Information Service (NTIS)

Controlling erosion is a serious and challenging task. Annually, erosion is responsible for billions of dollars of damage worldwide. Erosion control mats (ECMs) were developed to control erosion and provide stability until vegetation can be established. T...

B. Shepley R. Smith G. L. Jackson

2002-01-01

10

WIND EROSION: PROCESSES AND CONTROL  

Technology Transfer Automated Retrieval System (TEKTRAN)

The presentation will cover the mission and research of the Wind Erosion Research Unit as well as exploring the problem, mechnics, and control of soil erosion by wind. After the lecture, the class will tour the Wind Erosion Research Unit wind tunnel facility where they will get a first hand look at...

11

WATER QUALITY OF NORTHERN MISSISSIPPI HILL LAND STREAMS IN THE DEMONSTRATION EROSION CONTROL (DEC) PROJECT DURING CALENDAR-YEAR 2002, WITH EMPHASIS ON CHLOROPHYLL  

Technology Transfer Automated Retrieval System (TEKTRAN)

As part of the Demonstration Erosion Control (DEC) Project in the Yazoo Basin, the Water Quality and Ecological Processes Research Unit at the USDA-ARS National Sedimentation Laboratory was requested by the US Army Corps of Engineers, Vicksburg District, to characterize current water quality. The D...

12

Title of Thesis: AN INVESTIGATION OF THE EFFICACY OF MAN-MADE TIDAL WETLANDS AS EROSION CONTROL TECHNIQUES ALONG THE CHESAPEAKE BAY AND A SOCIOLOGICAL EXAMINATION OF THE OPINIONS OF HOMEOWNERS ABOUT THE EROSION CONTROL PROJECT IMPLEMENTATION PROCESS  

Microsoft Academic Search

This report investigates the use of man-made tidal wetlands for erosion control along the Chesapeake Bay. Data was gathered from 80 shoreline sites on which tidal wetlands were implemented. Quantitative and qualitative data collection techniques, such as stem density counts and evidence of undercutting, were used to gauge the effectiveness of the wetlands. This data allowed for the development of

Justin Bosch; Cara Foley; Lindsay Lipinski; Chad McCarthy; James McNamara; Ashley Naimaster; Alya Raphael; Anna Yang

13

Erosion Control in Energy Systems.  

National Technical Information Service (NTIS)

The report of the findings of a Committee looking at erosion problems in energy systems: identifies the erosion conditions inherent in energy systems and categorizes them according to severity; describes the interplay between design and materials; describ...

1977-01-01

14

Controlling erosion in the Missouri River Basin  

NASA Astrophysics Data System (ADS)

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

Showstack, Randy

2012-09-01

15

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.

16

Robotic weld overlay coatings for erosion control  

SciTech Connect

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.

Not Available

1994-11-01

17

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.

18

Robotic weld overlay coatings for erosion control  

SciTech Connect

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

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

1993-04-18

19

7 CFR 3201.68 - Erosion control materials.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Erosion control materials. 3201.68 Section 3201...Items § 3201.68 Erosion control materials. (a) Definition. Woven...qualifying biobased erosion control materials. By that date, Federal...

2013-01-01

20

Modifying Erosion Control Structures for Ecological Benefits  

Technology Transfer Automated Retrieval System (TEKTRAN)

Edge-of-field water control structures known as drop pipes are widely employed to control gully erosion, particularly along incised streams. Previous research showed that incidental habitats created by installation of these structures supplemented stream corridors by supporting large numbers of inv...

21

Technological Solutions for Erosion Control and Water Clarification using Polyacrylamide (PAM) and PAM blends  

Microsoft Academic Search

Years of research, corporate publications, patents and trademarks have led to a greatly improved and cost efficient erosion control technology. Development of new polyacrylamide (PAM) blends and delivery methodologies has resulted in a whole new class of in-situ erosion control and water clarification tools. Multi-disciplinary environmental industry projects for mining, construction, water treatment and biological research have proven this class

William Gowdy; Jerry Hanna; Steven R. Iwinski; Dave Martin

22

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

ERIC Educational Resources Information Center

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

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

23

The control of erosion-corrosion in slurry pipelines  

Microsoft Academic Search

The results of erosion-corrosion testing in pilot plant slurry pipelines are related to the behaviour of operating slurry pipelines and the control of erosion-corrosion in such systems by use of inhibitors, solution conditioning and adjustment of slurry parameters. The erosion-corrosion component of the total wear is oxygen-mass-transfer controlled and the magnitude of the erosion-corrosion can be estimated using well established

Postlethwaite

1987-01-01

24

Use of palm-mat geotextiles for rainsplash erosion control  

Microsoft Academic Search

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

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

2010-01-01

25

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

PubMed

This paper summarizes key findings and identifies the main lessons learnt from a 5-year (2002-2008) coordinated research project (CRP) on "Assessing the effectiveness of soil conservation measures for sustainable watershed management and crop production using fallout radionuclides" (D1.50.08), organized and funded by the International Atomic Energy Agency through the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. The project brought together nineteen participants, from Australia, Austria, Brazil, Canada, Chile, China, Japan, Morocco, Pakistan, Poland, Romania, Russian Federation, Turkey, United Kingdom, United States of America and Vietnam, involved in the use of nuclear techniques and, more particularly, fallout radionuclides (FRN) to assess the relative impacts of different soil conservation measures on soil erosion and land productivity. The overall objective of the CRP was to develop improved land use and management strategies for sustainable watershed management through effective soil erosion control practices, by the use of ¹³?Cs (half-life of 30.2 years), ²¹?Pb(ex) (half-life of 22.3 years) and ?Be (half-life of 53.4 days) for measuring soil erosion over several spatial and temporal scales. The environmental conditions under which the different research teams applied the tools based on the use of fallout radionuclides varied considerably--a variety of climates, soils, topographies and land uses. Nevertheless, the achievements of the CRP, as reflected in this overview paper, demonstrate that fallout radionuclide-based techniques are powerful tools to assess soil erosion/deposition at several spatial and temporal scales in a wide range of environments, and offer potential to monitor soil quality. The success of the CRP has stimulated an interest in many IAEA Member States in the use of these methodologies to identify factors and practices that can enhance sustainable agriculture and minimize land degradation. PMID:22336567

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

2012-02-14

26

Adapting WEPP (Water Erosion Prediction Project) for Forest Watershed Erosion Modeling  

NASA Astrophysics Data System (ADS)

There has been an increasing public concern over forest stream pollution by excessive sedimentation resulting from human activities. Adequate and reliable erosion simulation tools are urgently needed for sound forest resources management. Computer models for predicting watershed runoff and erosion have been developed during the past. These models, however, are often limited in their applications due to inappropriate representation of the hydrological processes involved. The Water Erosion Prediction Project (WEPP) watershed model has proved useful in certain forest applications such as modeling erosion from a segment of insloped or outsloped road, harvested units, and burned units. Nevertheless, when used for modeling water flow and sediment discharge from a forest watershed of complex topography and channel systems, WEPP consistently underestimates these quantities, in particular, the water flow at the watershed outlet. The main purpose of this study was to improve the WEPP watershed model such that it can be applied to adequately simulate forest watershed hydrology and erosion. The specific objectives were to: (1) identify and correct WEPP algorithms and subroutines that inappropriately represent forest watershed hydrologic processes; and (2) assess the performance of the modified model by applying it a real forested watershed in the Pacific Northwest, USA. In modifying the WEPP model, changes were primarily made in the approach to, and algorithms for modeling deep percolation of soil water and subsurface lateral flow. The modified codes were subsequently applied to Hermada watershed, a small watershed located in the Boise National Forest in northern Idaho. The modeling results were compared with those obtained by using the original WEPP and the field-observed runoff and erosion data. Conclusions of this study include: (1) compared to the original model, the modified WEPP more realistically and properly represents the hydrologic processes in a forest setting; and (2) application of the modified model produced satisfactory results, demonstrating the adequacy of the model modifications.

Dun, S.; Wu, J. Q.; Elliot, W. J.; Robichaud, P. R.; Flanagan, D. C.

2006-12-01

27

Robotic weld overlay coatings for erosion control.  

National Technical Information Service (NTIS)

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. ...

1994-01-01

28

Abbreviated Detailed Project Report, Mitigation of Erosion Damages, Delaware River, Pennsville, New Jersey.  

National Technical Information Service (NTIS)

The purpose of this detailed project study and report was to determine how much shoreline erosion damage was attributable to a dike constructed at Pennsville, NJ on the Delaware River and to investigate possible solutions to the control of the bank erosio...

1980-01-01

29

Evaluation of compost blankets for erosion control from disturbed lands.  

PubMed

Soil erosion due to water and wind results in the loss of valuable top soil and causes land degradation and environmental quality problems. Site specific best management practices (BMP) are needed to curb erosion and sediment control and in turn, increase productivity of lands and sustain environmental quality. The aim of this study was to investigate the effectiveness of three different types of biodegradable erosion control blankets- fine compost, mulch, and 50-50 mixture of compost and mulch, for soil erosion control under field and laboratory-scale experiments. Quantitative analysis was conducted by comparing the sediment load in the runoff collected from sloped and tilled plots in the field and in the laboratory with the erosion control blankets. The field plots had an average slope of 3.5% and experiments were conducted under natural rainfall conditions, while the laboratory experiments were conducted at 4, 8 and 16% slopes under simulated rainfall conditions. Results obtained from the field experiments indicated that the 50-50 mixture of compost and mulch provides the best erosion control measures as compared to using either the compost or the mulch blanket alone. Laboratory results under simulated rains indicated that both mulch cover and the 50-50 mixture of mulch and compost cover provided better erosion control measures compared to using the compost alone. Although these results indicate that the 50-50 mixtures and the mulch in laboratory experiments are the best measures among the three erosion control blankets, all three types of blankets provide very effective erosion control measures from bare-soil surface. Results of this study can be used in controlling erosion and sediment from disturbed lands with compost mulch application. Testing different mixture ratios and types of mulch and composts, and their efficiencies in retaining various soil nutrients may provide more quantitative data for developing erosion control plans. PMID:21036461

Bhattarai, Rabin; Kalita, Prasanta K; Yatsu, Shotaro; Howard, Heidi R; Svendsen, Niels G

2010-10-30

30

Poplars and willows for soil erosion control in New Zealand  

Microsoft Academic Search

Poplars (Populus) and willows (Salix) are exotic to New Zealand and have been introduced and cultivated over the last 160 years, for soil erosion control on pastoral hill country, riverbank protection, shade, windbreaks and woodlot forestry. During the 1960s and 1970s over two million poplars were planted in government-subsidised erosion control schemes. Planting techniques and patterns are discussed. This type

A. G Wilkinson

1999-01-01

31

A Review of Mulches to Control Wind Erosion  

Microsoft Academic Search

HE need to increase food production and improve T the quality of our environment has prompted a search for materials to control wind and water erosion. This paper is a review of research and development as- sociated with application, methods, and amounts of mulch types-crop residues, chemical soil stabilizers, and feedlot wastes (manure)-required to control wind erosion. An effective wind

D. V. Armbrust

32

SOIL EROSION BY WIND AND ITS CONTROL  

Technology Transfer Automated Retrieval System (TEKTRAN)

More than sixty years after the end of the Dust Bowl, wind erosion continues to threaten the sustainability of our nations' natural resources. The Natural Resources Conservation Service (NRCS) is the primary agency through which research and knowledge about wind erosion is directly transferred to t...

33

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

34

Alternatives for Control of Shoreline Erosion at Fort Eustis, Virginia.  

National Technical Information Service (NTIS)

This study gives alternatives for control of shoreline erosion at thirteen sites at Fort Eustis, Virginia. Water waves are the major cause of erosion in the study area with design wave heights from 1.0 to 4.0 ft. Design still-water levels are +5.6 ft MLW ...

E. B. Perry R. D. Carver R. L. Lazor

1991-01-01

35

MULTIPLE POLYACRYLAMIDE APPLICATIONS FOR CONTROLLING SPRINKLER IRRIGATION RUNOFF AND EROSION  

Microsoft Academic Search

ABSTRACT. Runoff under sprinkler irrigation systems causes soil erosion and reduces water infiltration uniformity. Previous studies have shown that applying polyacrylamide,(PAM) with irrigation water can reduce runoff and soil loss. We hypothesized that applying PAM with three consecutive irrigations would more effectively control runoff and erosion than applying the same total amount,of PAM with a single irrigation. This study was

D. L. Bjorneberg; J. K. Aase

2000-01-01

36

18 CFR 1304.202 - General sediment and erosion control provisions.  

Code of Federal Regulations, 2013 CFR

...General sediment and erosion control provisions. 1304.202...ALTERATIONS TVA-Owned Residential Access Shoreland § 1304.202 General sediment and erosion control provisions. (a) During...appropriate erosion and sediment control measures be utilized to...

2013-04-01

37

A comparison of three erosion control mulches on decommissioned ...  

Treesearch

Title: A comparison of three erosion control mulches on decommissioned forest road corridors in the northern Rocky Mountains, United States ... This article was written and prepared by U.S. Government employees on official time, and is ...

38

Leucaena— A promising soil-erosion-control plant  

Microsoft Academic Search

This woody legume, originally native to Mexico but now naturalized in Arizona, Florida and Texas, has been extensively used\\u000a in Indonesia for soil erosion control and should be similarly employed in our Southern States.

M. J. Dijkman

1950-01-01

39

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

40

Sprinkler Irrigation Runoff and Erosion Control with Polyacrylamide — Laboratory Tests  

Microsoft Academic Search

ABSTRACT Many semiarid and arid soils are prone to irrigation-induced ero- sion. Polyacrylamide (PAM) greatly reduces erosion from furrow irrigation. We hypothesized that PAM applied via sprinklers will provide erosion control and benefit water infiltration and aggregate stability. Screened (6.4 mm) Rad silt loam (coarse silty, mixed, super- active mesic Durinodic Xeric Haplocambid) was placed in 1.5 by 1.2 by

J. Kristian Aase; David L. Bjorneberg; Robert E. Sojka

1998-01-01

41

Hillslope runoff and erosion as affected by rolled erosion control systems: a field study  

NASA Astrophysics Data System (ADS)

A replicated field study using rainfall simulation and overland flow application was conducted in central Oahu, Hawaii, on a clay-dominated Oxisol with a 9% slope. Three main treatment groups were examined: a bare treatment, a group of four rolled erosion control systems (RECSs) with open weave designs, and a group of five randomly oriented fibre RECSs. A total of 1122 measurements of runoff and erosion were made to examine treatment differences and to explore temporal patterns in runoff and sediment flux.All erosion control systems significantly delayed the time required to generate plot runoff under both simulated rainfall (35 mm h-1) and the more intense trickle flow application (114 mm h-1). Once runoff was generated during the rainfall application phase, the bare treatment runoff coefficients were significantly lower than those from the two groups of RECSs, as surface seal disruption by rilling is inferred to have enhanced infiltration in the bare treatments. During the more intense phase of overland flow application, the reverse pattern was observed. Interrill contributing-area roughness was reduced on the bare treatment, facilitating increased runoff to well-developed rill networks. Meanwhile, the form roughness associated with the RECSs delayed interrill flow to the poorly organized rills that formed under some of the RECSs.Regardless of runoff variations between treatments, sediment output was significantly lower from all surfaces covered by RECSs. The median cumulative sediment output from the bare surfaces was 6.9 kg, compared with 1.2 kg from the open-weave RECSs and 0.2 kg from the random-fibre RECSs. The random-fibre systems were particularly effective under the more stressful overland flow application phase, with 63 times less sediment eroded than the bare treatments and 12 times less than that from the open-weave systems. Architectural design differences between the two groups of RECSs are discussed in light of their relation to erosion process dynamics and shear stress partitioning.

Sutherland, Ross A.; Ziegler, Alan D.

2006-08-01

42

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

43

Virginia Beach, Virginia - Beach Erosion Control Project.  

National Technical Information Service (NTIS)

Continued nourishment is proposed of 3-1/3 miles of Virginia Beach shoreline by hydraulic dredge and truck haul. Environmental impacts include the removal of approximately 2 acres of marsh, turbidity increases during dredging, loss of benthic life in chan...

1973-01-01

44

Surface erosion control on the evolution of the deep lithosphere  

NASA Astrophysics Data System (ADS)

Thermal-mechanical numerical experiments are used to consider if the influence of surface erosion during continental plate collision and orogenesis extends beneath the crust into the mantle lithosphere. The models demonstrate that the modification of crustal mass flux by surface denudation can change the evolution of the deforming crust and consequently alter the behavior of the crust-mantle interface. The mantle lithosphere responds to these variable dynamics: with active surface erosion, stable subduction-like plate consumption is maintained; in the absence of erosion, subduction is inhibited by accumulating crust, causing the convergent plates to steepen dip, detach, and reverse consumption polarity. With strong subducting plates, the removal of surface processes can trigger a transition from stable subduction to delamination and/or retreat of the convergent plate. The influence of surface erosion is less important for mantle lithosphere undergoing Rayleigh-Taylor type dripping and is not significant at ocean plate collision, where there is relatively little buoyant crust to clog the subduction zone. The results of the experiments demonstrate that in certain tectonic regimes the influence of climate-controlled surface processes may reach much deeper into the lithosphere than has previously been appreciated.

Pysklywec, Russell N.

2006-04-01

45

Does control of soil erosion inhibit aquatic eutrophication?  

PubMed

Much of the phosphorus (P) from erosive soils is transported to water bodies together with eroded soil. Studies clarifying the impact of soil erosion on eutrophication have sought largely to quantify the reserves of P in soil particles that can be desorbed in different types of receiving waters. Aquatic microbiology has revealed that the cycling of P is coupled to the availability of common electron acceptors, Fe oxides and SO?, through anaerobic mineralization in sediments. Eroded soil is also rich in Fe oxides, and their effect on the coupled cycling of C, Fe, S, and P has been neglected in eutrophication research. Soil erosion, and its control, should therefore be studied by considering not only the processes occurring in the water phase but also those taking place after the soil particles have settled to the bottom. We propose that in SO?-rich systems, Fe oxides transported by eroded soil may promote Fe cycling, inhibit microbial SO? reduction and maintain the ability of sediment to retain P. We discuss the mechanisms through which eroded soil may affect benthic mineralization processes and the manner in which soil erosion may contribute to or counteract eutrophication. PMID:22054580

Ekholm, Petri; Lehtoranta, Jouni

2011-10-05

46

System and method for controlling erosion of a shoreline  

SciTech Connect

This patent describes a system for controlling erosion of the slope between the waterline of a shoreline. The system comprises an elongated conduit; means to pivotably secure the conduit to the shoreline approximately at the waterline; a plurality of individual armor bags attached to the conduit; and means for filling all of the individual armor bags with a grout material whereby the armor bags when filled with the grout material will be positioned as a unit onto the slope below the waterline.

Ingersoll, R.W.

1987-09-15

47

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

48

Effectiveness of coir-based rolled erosion control systems in reducing sediment transport from hillslopes  

Microsoft Academic Search

Accelerated soil erosion is ubiquitous on human-modified hillslopes. A variety of erosion control products have been developed to reduce on-site soil resource degradation, and off-site transport of sediment and sediment-associated contaminants to receiving water bodies. However, limited quantitative data are available to assess erosion reduction effectiveness, and to establish the salient properties of the erosion control products. A replicated field-based

Ross A. Sutherland; Alan D. Ziegler

2007-01-01

49

Control of Eolian soil erosion from waste site surface barriers  

SciTech Connect

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

Ligotke, M.W.

1994-11-01

50

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

51

Farmers' Knowledge of Soil Erosion and Control Measures in the Northwestern Highlands of Ethiopia  

Microsoft Academic Search

This study examines farmers' perception and knowledge of the soil erosion process and its impacts and control techniques in the northwestern highlands of Ethiopia. It is based on interviews with 119 farmers and informal discussions with 12 farmers from four villages. Of the interviewed farmers, over 83 percent stated that soil erosion was damaging their agricultural lands. Visible soil erosion

Woldeamlak Bewket

2011-01-01

52

Wetland Platform Erosion by Wave Action and its Implications for Future Mitigation Projects in South Louisiana  

NASA Astrophysics Data System (ADS)

The transition of marshland to open water in south Louisiana continues at an alarming rate, and freshwater diversions and marsh restoration projects have been implemented or are planned to address this loss. This project examines the magnitude and impact of wave-induced subaqueous platform erosion that occurs during and following subsidence of the subaerial marsh. Study and control sites have been chosen in Breton Sound, where an existing freshwater diversion project (Caernarvon) has been operational since 1991; Barataria Bay, where the Davis Pond diversion has been active since 2003; and the Deltas National Wildlife Refuge (DNWR), where marshes are still receiving significant freshwater and sediment from the Mississippi River. Study grids are established along marsh fringes in bay-fronting, gulf-fronting, and interior ponds that have a variety of orientations and open water fetch to predominant wave attack and in recent years (since the 1930s) have shown significant wetland loss. Subaqueous platform elevation and stratigraphy are examined with vibracores and transit elevation transects and detailed bathymetric maps of the 1 km grids are also made with an Odom Hydrotrak HT100 fathometer. Preliminary results suggest that the overall magnitude of wave-induced erosion is extreme (deflation of 1-1.5 m) in Barataria Bay sites, but may not be as great a magnitude in Breton Sound or the DNWR sites. Shoreline orientation to wave attack, the composition and resistance to wave re-working of the underlying sediment, or the presence of submerged aquatic vegetation (SAV) that serves to stabilize the substrata may help explain the resultant site to site variability. Predominant in many sites, once the aerial marsh has submerged, a portion of the peat deposits is preserved below more recent onlapping bay bottom sediments.

Wilson, C.; Allison, M.

2004-12-01

53

Erosion control at construction sites on red clay soils  

NASA Astrophysics Data System (ADS)

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

Lemly, A. Dennis

1982-07-01

54

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...

55

Project Planning and Control  

Microsoft Academic Search

\\u000a With projects growing in complexity and size, their planning and control becomes an increasingly important project management\\u000a function. Elementary methods and tools for accomplishing this task are described in this chapter. Basically, project planning\\u000a consists of developing a schedule and a budget for the execution of the project. Most commonly, this is done by applying network\\u000a based planning methods. Due

Robert Klein

56

Project management controls  

SciTech Connect

Project management controls are utilized to enhance the probability that a project will be successful. The control system used by a project manager can take many forms and can be applied at different times to varying degrees on a given project depending upon its complexity. The Consolidated Incineration Facility (CIF) is one project of many at the Savannah River Site (SRS). The United States Department of Energy Order 4700.1 is a project management system that is applied on a site-wide basis, thus including the CIF. The control system required by this order is proceduralized to ensure that it is applied in a consistent manner and will produce reliable results. These results provide the project manager with a correlation of both costs and schedule within the defined scope to adequately asses the status of the project. This is an iterative process and can be simply stated: plan, actual, variance, corrective action, prediction, and revision. This paper presents the basis for the project management controls applied at the Savannah River Site.

Hardin, D.S. [Bechtel Savannah River Inc., Savannah River Site, Aiken, SC (United States); Carnes, W.S. [Westinghouse Savannah River Co., Aiken, SC (United States)

1990-12-31

57

Project management controls  

SciTech Connect

Project management controls are utilized to enhance the probability that a project will be successful. The control system used by a project manager can take many forms and can be applied at different times to varying degrees on a given project depending upon its complexity. The Consolidated Incineration Facility (CIF) is one project of many at the Savannah River Site (SRS). The United States Department of Energy Order 4700.1 is a project management system that is applied on a site-wide basis, thus including the CIF. The control system required by this order is proceduralized to ensure that it is applied in a consistent manner and will produce reliable results. These results provide the project manager with a correlation of both costs and schedule within the defined scope to adequately asses the status of the project. This is an iterative process and can be simply stated: plan, actual, variance, corrective action, prediction, and revision. This paper presents the basis for the project management controls applied at the Savannah River Site.

Hardin, D.S. (Bechtel Savannah River Inc., Savannah River Site, Aiken, SC (United States)); Carnes, W.S. (Westinghouse Savannah River Co., Aiken, SC (United States))

1990-01-01

58

Performance of biological erosion control in New Zealand soft rock hill terrain  

Microsoft Academic Search

An investigation of the performance of biological erosion control measures applied to support pastoral land use in soft rock hill country has yielded information which can be applied in the design of more sustainable, silvopastoral land uses. Vegetation-based treatments, centred particularly on use of fast-growing poplars and willows, have successfully controlled a range of gully erosion and earthflow mass movement

R. C. Thompson; P. G. Luckman

1993-01-01

59

How two single events control the erosion process on citrus orchards in the Montesa soil erosion research station  

NASA Astrophysics Data System (ADS)

Single events control the soil erosion processes on Mediterranean type ecosystems. They contribute with the largest soil and water losses. A five year research carried out on the soil erosion experimental station of Montesa, eastern Spain demonstrates that the soil erosion by water is mainly concentrated on high intensity (> 100 mm day-1) thunderstorms. Six plots (300 m2) were built in 2003 to collect runoff and sediments after each rainfall event. The measurements show that 91.34 % of the total soil loss and the 76.32 % of the runoff collected from 2004 to 2008 was collected during two rainfall events that surpassed 160 mm day-1. The six plots were under organic farming strategies and then the soil losses were always lower than 1 Mg ha-1 year-1. Under dense vegetation cover found on organic farming orchards the soil erosion process is concentrated on short periods of time. In fact, two days of rainfall contributed with 9-times more runoff and soil losses than the 345 days of rainfall during the 5 year times of the study.

Cerdà, A.; Giménez-Morera, A.; Domínguez-Gento, A.

2010-05-01

60

Robotic weld overlay coatings for erosion control. Quarterly technical progress report, January 1994--March 1994  

SciTech Connect

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 waterwalls 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 circulated fluidized beds.

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

1994-04-21

61

Using the Water Erosion Prediction Project (WEPP) model to simulate field-observed runoff and erosion in the Apennines mountain range, Italy  

NASA Astrophysics Data System (ADS)

The Water Erosion Prediction Project (WEPP) model was tested using data from a detailed study conducted on experimental plots in the Apennines Mountain Range, northern Italy. Runoff, soil water and sediment data, together with weather information, were collected on an hourly basis at the study site. WEPP was first applied to simulate transient surface runoff, soil water and erosion. Two important input parameters, the biomass energy ratio for crop and the effective hydraulic conductivity of surface soil, were calibrated using field-observed runoff, soil water, erosion and plant biomass data. The calibrated model was then used to simulate the hydrologic and erosion impacts of three typical crop rotations, thereby to evaluate their abilities in reducing surface runoff and sediment yield. Results indicated that, with the definition of a restrictive layer at the bottom of the soil profile and the calibration of the two crucial model parameters, WEPP could adequately account for the water balance for the modeled experimental plot. For the study area, continuous corn with a conservation practice that delayed primary and secondary tillages produced low surface runoff and soil erosion, from both field observation and WEPP modeling. However, this mono-cultural practice may lead to accelerated soil-quality degradation. On the other hand, a four-year-rotation, corn wheat alfalfa alfalfa, was predicted to substantially reduce soil erosion and has potential to become a sustainable cropping system under the pedo-climatic settings of the study area.

Pieri, Linda; Bittelli, Marco; Wu, Joan Q.; Dun, Shuhui; Flanagan, Dennis C.; Pisa, Paola Rossi; Ventura, Francesca; Salvatorelli, Fiorenzo

2007-03-01

62

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

SciTech Connect

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

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

1993-04-18

63

Erosion Control at the Ares Facility Kirtland Air Force Base, New Mexico.  

National Technical Information Service (NTIS)

The report describes application of a dust-control system, DCA-1295 reinforced with fiberglass, for erosion control. Application conditions were unusual in several ways. A soil sterilant was used prior to application of the DCA-1295/fiberglass system afte...

C. R. Styron

1972-01-01

64

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

Microsoft Academic Search

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

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

2005-01-01

65

Influence of rolled erosion control systems on temporal rainsplash response—a laboratory rainfall simulation experiment  

Microsoft Academic Search

Reduction of erosion and sediment-related pollution from urban construction sites or other degraded hillslopes often relies on the initial application of suitable rolled erosion control systems (RECS) before natural vegetation cover can be established. However, research has not clearly explained why some RECS perform better than others, or under what particular conditions one system is more suitable than another. An

A. D. Ziegler; R. A. Sutherland; L. T. Tran

1997-01-01

66

Control and evaluation of particle impact conditions in a sand erosion test facility  

Microsoft Academic Search

For the prediction of actual damage to plant component materials and for making the erosion mechanisms clear, it is important to control and to evaluate the particle impact conditions in a testing facility. A sand blast type erosion test rig, which can achieve the particle impact velocities up to 135ms?1 and a wide range of impact angles has been constructed.

Y. I Oka; M Nishimura; K Nagahashi; M Matsumura

2001-01-01

67

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

68

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

69

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

70

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

NASA Astrophysics Data System (ADS)

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

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

2004-12-01

71

Investigation of Erosion Control Materials for Ditches in Highway Corridors in Missouri.  

National Technical Information Service (NTIS)

Plastic mat (Enkamat), Mulch Blanket (Hold Gro), Excelsior Blanket (Curlex Blanket), and Lightweight Mulch Blanket (Roll Lite) were installed and evaluated as alternates to concrete ditch liner, sod, and plastic netting over straw used for erosion control...

1983-01-01

72

Control of Eolian soil erosion from waste site surface barriers  

Microsoft Academic Search

Physical models were tested in a wind tunnel to determine optimum surface-ravel admixtures for protecting silt-loam soil from erosion by, wind and saltating, sand stresses. The tests were performed to support the development of a natural-material surface barrier for and waste sites. Plans call for a 2-m deep silt-loam soil reservoir to retain infiltrating water from rainfall and snowmelt. The

Ligotke

1994-01-01

73

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

74

Shoreline erosion control using marsh vegetation and low-cost structures  

SciTech Connect

Erosion is a serious threat to waterfront property along most of North Carolina's extensive estuarine shoreline. It is accelerated by man's intensive use and mismanagement. As demand for shoreline property increases -- for homesites, recreational areas, marinas and industrial sites -- its value increases, and landowners become more concerned about loss of land to erosion. There is a variety of erosion-control methods -- some beneficial, some useless and others that are even detrimental. Structural methods such as bulkheads, groins, revetments and riprap are often effective. But they are expensive to build and maintain and may have adverse environmental effects. Establishing vegetation is much cheaper than structural methods of erosion control, and the new marsh provides habitat, food and nutrients for organisms in the surrounding estuarine waters.

Broome, S.W.; Rogers, S.M.; Seneca, E.D.; Burgess, C.B.

1992-01-01

75

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

Microsoft Academic Search

In recent years, high-molecular-weight anionic polyacrylamide (PAM) have been widely tested on a variety of soils, primarily\\u000a in water erosion control. However, little information is available regarding the effectiveness of PAM on preventing soil loss\\u000a from wind erosion. The research adopted room wind tunnel experiment, two kinds of soils were used which were from the agro-pastoral\\u000a area of Inner Mongolia,

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

2008-01-01

76

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

77

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

NASA Astrophysics Data System (ADS)

To understand landscape response to climate change, baseline controls on erosion rates must be established for given climate conditions. Theory suggests a number of climate metrics should be important to erosion (i.e. precipitation, temperature, storminess, seasonality, snow fraction). Nevertheless, definitive field evidence quantifying how climate affects erosion rate has proven difficult to obtain. This is at least partly due to the difficulty of isolating climatic influences on erosion rates from topographic and rock strength influences. We circumvent this problem by evaluating how climate influences the relationship between erosion rate and topography in settings with similar rock types. At steady state, tectonic uplift dictates erosion rate, and climate and rock strength are manifest as changes in erosional efficiency - the topographic relief necessary to maintain the tectonically imposed erosion rate. In fluvial landscapes, bedrock rivers set the relevant scale of topographic relief, which can be described by the channel steepness index. A number of recent studies have shown that the relationship between channel steepness and millennial scale erosion rates is non-linear, implying that erosional efficiency increases with relief. Work in the San Gabriel Mountains suggests this relationship is due to erosion thresholds that limit incision of channels in low relief landscapes. By using a fluvial incision model that incorporates a range of daily discharge events coupled with an erosion threshold (Lague et al., 2005), the influence of flood frequency on the relationship between channel steepness and erosion rate can be explored. We apply this same modeling approach to five other landscapes that exhibit a range of channel steepness, have similar rock types (granitoids), but that are in dramatically different climate regimes ranging from desert to rainforest (annual rainfall, P, from 0.25 to 3 m/yr). Specifically, we present new cosmogenic 10Be erosion rate data from the San Jacinto Mountains, CA (P = ~0.25 m/yr); Sierra San Pedro Martir, MX (P = ~0.25 m/yr); Sangre de Cristo Mountains, NM (P = ~1 m/yr); North Sierra Nevada, CA (P = ~2 m/yr); Sierra Nombre de Dios, HN (P = ~3 m/yr). These landscapes exhibit large differences in mean annual precipitation, mean annual temperature, mean daily runoff, and runoff variability. Using long time-series hydrological and meteorological data, we assess the capabilities and limitations of stochastic-threshold incision models for predicting the relationship between channel steepness and erosion rate. Further, we document quantifiable changes in erosional efficiency for differing climate conditions that can be used as a baseline for interpreting the effects of climate change in steep mountain catchments.

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

2011-12-01

78

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

NASA Astrophysics Data System (ADS)

Proper spatial and temporal treatments of climate change scenarios projected by General Circulation Models (GCMs) are critical to accurate assessment of climatic impacts on natural resources and ecosystems. For accurate prediction of soil erosion risk at a particular farm or field under climate change, climate change scenarios projected by General Circulation Models (GCMs) must be appropriately downscaled to the target location. The objective of this study was to evaluate site-specific impacts of climate change on soil erosion and surface hydrology at El Reno, Oklahoma in U.S.A. using the Water Erosion Prediction Project (WEPP) model. Climate change scenarios during 2010-2039 projected by four GCMs (CCSR/NIES, CGCM2, CSIRO-Mk2 and HadCM3) under three emission scenarios (A2, B2 and GGa) were used. Monthly projections at the GCMs grid scales were tempo-spatially downscaled to daily weather data at the El Reno location. Univariate transfer functions were derived by matching probability distributions between location-measured and GCM-projected monthly precipitation and temperature for the 1957-2006 period. The derived functions were used to spatially downscale the GCMs monthly projections of 2010-2039 to the El Reno unit watershed. The downscaled monthly data were further disaggregated to daily weather series using a stochastic weather generator (CLIGEN). Potential changes in soil erosion risk or uncertainty at the study location will be evaluated using soil erosion rates predicted using the WEPP model for the climate change scenarios projected by the four GCMs. The effectiveness of conservation tillage under future climate change will also be explored.

Zhang, X.-C. John

2010-05-01

79

Alternative flow control nozzles/energy dissipation of highly erosive fluids: Final report  

SciTech Connect

An innovative Flow Control Device (FCD) utilizing multiple pairs of opposed coaxially-aligned nozzles was successfully tested in a three-phase erosive-flow stream. A mixture of air, water, and silica was selected to produce velocities representative of those resulting in a high-pressure letdown coal-liquefaction process. Aluminum was utilized for test hardware to provide accelerated erosion data. A globe valve with aluminum trim was tested at the same operating conditions to provide baseline performance data for direct comparison with nozzle results. The time rate of increase in flow-control area of the FCD was less than one third that of the globe valve. This demonstrates the relative severity of impingement erosion over scouring erosion, as there are no abrupt directional changes in the nozzle flow. The receiver walls showed no erosion damage for liquid levels well below the nozzle exit, indicating very efficient energy dissipation in the jet-impact zone. These favorable results coupled with the design simplicity of the FCD provides a solid basis for further development. 15 refs., 33 figs., 4 tabs.

Maddox, P.

1986-09-01

80

Earned quality: improving project control  

Microsoft Academic Search

The concept of earned value has been widely used in project management to measure and control the achievement of time and cost objectives. However, no such equivalent concept has ever been devised to assess and monitor the quality of a project. The goal of the paper is to propose a multiattribute utility theory approach that enables project managers to measure

J. P. Paquin; J. Couillard; R. Paquin; D. Godcharles

1996-01-01

81

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

82

Guide to the Development of an Air Force Erosion Control Manual.  

National Technical Information Service (NTIS)

The report is a comprehensive summary of research and operations experience in wind and water erosion control. It is intended to serve as a broad technical guide for command personnel who are directly involved in the search for effective solutions to seve...

D. F. Kibler C. E. Busby

1970-01-01

83

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

ERIC Educational Resources Information Center

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

Porter, Harry L., Jr.

84

Erosive pustular dermatosis of the leg: long-term control with topical tacrolimus.  

PubMed

Erosive pustular dermatosis of the leg is an unusual form of sterile pustulosis that typically affects the lower limbs of elderly patients. We report the cases of two women who developed erythematous skin plaques with pustules that coalesced and evolved into erosions and crusted areas. Histology showed epidermal spongiosis with subcorneal pustules and a dermal infiltrate with eosinophils and neutrophils. Lesions were treated with topical clobetasol propionate 0.05% for 10 days followed by topical tacrolimus daily until complete resolution, and then twice weekly for 1 year, without relapse. The response to topical corticosteroids and tacrolimus further support the close relationship with erosive pustular dermatosis of the scalp. Topical therapy with tacrolimus may offer good long-term disease control. PMID:21332681

Dall'Olio, Elena; Rosina, Paolo; Girolomoni, Giampiero

2011-02-01

85

Ediz Hook Beach Erosion Control, Port Angeles, Washington.  

National Technical Information Service (NTIS)

The project involves new rock revetment and beach nourishment of about 10,000 feet of the seaward shore of Ediz Hook. Material for the revetment would come from existing quarries in the Puget Sound Area, and beach nourishment material would come from a so...

1972-01-01

86

SEDIMENTATION IN THREE SMALL EROSION CONTROL RESERVOIRS IN NORTH MISSISSIPPI  

Technology Transfer Automated Retrieval System (TEKTRAN)

The water storage capacity and dam integrity of thousands of flood control reservoirs built in the last 50 years are compromised by excessive impounded sediments. The fate of these structures depends on the amount and characteristics of the impounded material. To aid in understanding the scope of ...

87

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...

88

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

NASA Astrophysics Data System (ADS)

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 richness (especially for intolerant groups) and low stability. These effects were most evident at the poorly managed sites. Sedimentation was the apparent major problem, but some changes at agricultural sites implied water quality problems. The groups most intolerant of agricultural runoff were Ephemeroptera, Plecoptera and Trichoptera. Tolerant species were usually filter-feeders or algal grazers, suggesting a modification of the food web by addition of particulate organic matter and nutrients. This study clearly indicates that agricultural runoff can severely impact stream biota. However, this impact can be greatly mitigated by currently recommended erosion control practices.

Lenat, David R.

1984-07-01

89

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

SciTech Connect

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

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

1990-06-01

90

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

Code of Federal Regulations, 2010 CFR

...Erosion, Sedimentation, and Pollution. 452.236-74 Section...Erosion, Sedimentation, and Pollution. As prescribed in 436...Erosion, Sedimentation, and Pollution (NOV 1996) (a) Operations...and muddying of streams, rivers, irrigation systems,...

2009-10-01

91

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

Code of Federal Regulations, 2010 CFR

...Erosion, Sedimentation, and Pollution. 452.236-74 Section...Erosion, Sedimentation, and Pollution. As prescribed in 436...Erosion, Sedimentation, and Pollution (NOV 1996) (a) Operations...and muddying of streams, rivers, irrigation systems,...

2010-10-01

92

Factors controlling soil erosion in small agricultural watersheds in central Navarre (Spain)  

NASA Astrophysics Data System (ADS)

Two experimental watersheds - La Tejería (1.69 km2) and Latxaga (2.07 km2)- located in the centre of Navarre (Spain) have been continually monitored for 13 years (1996-2009). As a result, a detailed description and a general characterization of the hydrological and erosion behaviour of these watersheds were published recently by the same authors of this current research. However, this information, although extensive and valuable, is still insufficient for finding out the internal functioning of these watersheds, especially those processes and factors controlling the erosion in their soils. Thus, the main objective of this article is to identify and weigh up the most relevant variables related to the production of sediments -and therefore to the predominant erosion processes- at the outlet of two grain-growing watersheds. All the above has the ultimate aim of gaining a better understanding of the hydrological-erosion behaviour of the typical agricultural watersheds in our region. A detailed statistical analysis was made of the extensive database available, to be specific, using multivariate methods: Principal Component Analysis (PCA) and Multivariate Regression (MR). Although these techniques do not establish per se any relation of dependence but that causality has to be subsequently formulated by the analyst, they are valuable analysis tools just the same. The PCA, particularly, permits a reduction in the large number of starting-off variables (in our case 28 metric and 1 categoric variables) identifying the most relevant ones which relate best to a specific illustrative variable. It should be clarified that the illustrative variables do not intervene in the analysis but are much useful as they facilitate the interpretation of the causality between each other with all the remaining variables. In our case, the fixed illustrative variable was, thus, the total production of sediments. Next, and complementarily to the PCA, an MR analysis was performed with the aim of quantifying the degree of importance of those variables recognized by means of the PCA as being explanatory of the erosion processes. The statistical analyses reveal that the variables which explained the generation of sediment in the watersheds studied best are, surprisingly, only two: the total runoff accumulated and the antecedent moisture; the latter was reflected by the mean flow generated one hour before the beginning of the event. Curiously, the intensity of the rainfall was hardly significant, which suggest that splash erosion is a minor form of soil erosion. In addition, the regression analysis indicates that of the 2 variables cited, the total runoff accumulated is, by far, that which carries the greatest weight at the moment of explaining the total generation of sediment.

Giménez, Rafael; Casalí, Javier; Díez, Javier; Grande, Ildefonso; Goñi, Mikel

2010-05-01

93

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

94

Materials for Advanced Turbine Engines (MATE). Project 4. Erosion Resistant Compressor Airfoil Coating.  

National Technical Information Service (NTIS)

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,...

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

1987-01-01

95

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

96

Microphonics control for Project X  

SciTech Connect

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

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

2011-03-01

97

Anthropogenic control on geomorphic process rates: can we slow down the erosion rates? (Geomorphology Outstanding Young Scientist Award & Penck Lecture)  

NASA Astrophysics Data System (ADS)

The surface of the Earth is changing rapidly, largely in response to anthropogenic perturbation. Direct anthropogenic disturbance of natural environments may be much larger in many places than the (projected) indirect effects of climate change. There is now large evidence that humans have significantly altered geomorphic process rates, mainly through changes in vegetation composition, density and cover. While much attention has been given to the impact of vegetation degradation on geomorphic process rates, I suggest that the pathway of restoration is equally important to investigate. First, vegetation recovery after crop abandonment has a rapid and drastic impact on geomorphic process rates. Our data from degraded catchments in the tropical Andes show that erosion rates can be reduced by up to 100 times when increasing the protective vegetation cover. During vegetation restoration, the combined effects of the reduction in surface runoff, sediment production and hydrological connectivity are stronger than the individual effects together. Therefore, changes in erosion and sedimentation during restoration are not simply the reverse of those observed during degradation. Second, anthropogenic perturbation causes a profound but often temporary change in geomorphic process rates. Reconstruction of soil erosion rates in Spain shows us that modern erosion rates in well-vegetated areas are similar to long-term rates, despite evidence of strong pulses in historical erosion rates after vegetation clearance and agriculture. The soil vegetation system might be resilient to short pulses of accelerated erosion (and deposition), as there might exist a dynamic coupling between soil erosion and production also in degraded environments.

Vanacker, V.

2012-04-01

98

Oklahoma Pediatric Injury Control Project.  

National Technical Information Service (NTIS)

The purpose of the Oklahoma Pediatric Injury Control Project was to increase the functional capacity of the Maternal and Child Health Service of the Oklahoma State Department of Health to address the problem of pediatric injuries. The objectives of the pr...

M. L. Brown

1994-01-01

99

Materials for advanced turbine engines (MATE). Project 4: erosion resistant compressor airfoil coating  

SciTech Connect

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.

1987-05-01

100

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

101

THE COLUMBIA PLATEAU WIND EROSION/AIR QUALITY PROJECT: TEN YEARS OF RESEARCH PROGRESS.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Highly erodible soils and fallow dryland fields often produce blowing dust emissions during wind storms. Several locations within the Columbia Plateau have failed to meet federal clean air standards during wind storms. A multi-disciplinary team has successfully defined mechanisms of wind erosion a...

102

Materials for advanced turbine engines (MATE). Project 4: erosion resistant compressor airfoil coating  

Microsoft Academic Search

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

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

1987-01-01

103

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

104

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

105

Robotic weld overlay coatings for erosion control. Quarterly technical progress report, October 1994--December 1994.  

National Technical Information Service (NTIS)

Research is presently being conducted to develop a criteria for selecting weld overlay coatings for erosion mitigation in Circulated Fluidized Beds. Initially, eleven weld overlay alloys were selected for erosion testing based upon a literature review. Al...

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

1995-01-01

106

Robotic weld overlay coatings for erosion control. Quarterly technical progress report, January 1994--March 1994.  

National Technical Information Service (NTIS)

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. ...

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

1994-01-01

107

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

108

Minimal climatic control on erosion rates in the Sierra Nevada, California  

Microsoft Academic Search

Climate is widely thought to regulate erosion rates, but the relationships among pre- cipitation, temperature, and erosion rate have remained speculative, because long-term erosion rates have been difficult to measure. We used cosmogenic nuclides to measure long-term erosion rates at climatically diverse sites in the Sierra Nevada, California, span- ning 20-180 cm\\/yr in annual precipitation and 4-15 8C in mean

Clifford S. Riebe; James W. Kirchner; Darryl E. Granger; Robert C. Finkel

2001-01-01

109

Cultural practices for soil erosion control in cassava-based cropping systems in Indonesia  

Microsoft Academic Search

In Indonesia about 1.3 million hectares of cassava are located on marginal sloping uplands, where soil erosion is a serious problem. Alfisols are the dominant soil type for cassava cultivation. Cassava cultivated on sloping land can cause severe erosion if it is not properly managed. A study on the effect of different cultural practices on erosion and yield of cassava

R. H. HOWELER

110

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

111

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

112

Robotic weld overlay coatings for erosion control. Quarterly technical progress report, July--September, 1994  

SciTech Connect

Research is presently being conducted to develop a criteria for selecting weld overlay coatings for erosion mitigation in Circulated Fluidized Beds. Initially, eleven weld overlay alloys were selected for erosion testing based upon a literature review. All eleven coatings were deposited on 1018 steel substrates using the plasma arc welding process. Ten samples from each coating were prepared for erosion testing. All selected coatings were erosion tested at 400 C and their erosion resistance was evaluated by determining the steady state erosion rate. In addition, the microstructure of each coating was characterized before and after the erosion tests. No correlations were found between room temperature hardness of the weld overlay coatings and their erosion resistance at elevated temperature. It was suggested that weld overlays mechanical properties such as fracture strength, toughness and work hardening rates may contributed to their erosion resistance. During the previous two quarters the microhardness tests were performed on the eroded samples in order to determine the size of the work hardened zone and the change in the coatings hardness due to erosion. As a result of these measurements it was established that one group of coatings deformed plastically, while another did not. In addition, the measurements of the weld overlays microhardness at 400 C were made. The coatings microhardness at 400 C was plotted versus their volume erosion rates. During the last quarter, erosion tests were performed for Inconel-625, 316L SS, and Iron-Aluminide wrought alloys in order to compare their erosion behavior with similar weld overlays. The results of microhardness profile measurements for all weld overlay coatings were analyzed. The factors that contribute to the erosion resistance of the coatings that deformed plastically are discussed in this progress report.

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

1994-10-26

113

PLATELET ACTIVATING FACTOR AND DISTINCT CHEMOKINES ARE ELEVATED IN MUCOSAL BIOPSIES OF EROSIVE COMPARED TO NON-EROSIVE REFLUX DISEASE PATIENTS AND CONTROLS  

PubMed Central

Background A distinction between symptomatic non-erosive reflux disease (NERD) and erosive esophagitis (EE) patientsis supported by the presence of inflammatory response in the mucosa of EE patients, leading to a damage of mucosal integrity. To explore the underlying mechanism of this difference we assessed inflammatory mediators in mucosal biopsies from EE and NERD patients and compared them to controls. Methods Nineteen NERD patients, fifteen EE patients and sixteen healthy subjects underwent endoscopy after a 3-week washout from PPI or H2 antagonists. Biopsies obtained from the distal esophagus, were examined by quantitative real-time polymerase chain reaction (qPCR) and multiplex ELISA for selected chemokines and lyso-PAF acetyltransferase (LysoPAF-AT), the enzyme responsible for production of platelet activating factor (PAF). Results Expression of LysoPAF-AT and multiple chemokines was significantly increased in mucosal biopsies derived from EE patients, when compared to NERD patients and healthy controls. Upregulated chemokines included interleukin 8, eotaxin-1, -2 and -3, macrophage inflammatory protein-1? (MIP-1?) and monocyte chemoattractant protein-1 (MCP-1). LysoPAF-AT and the chemokine profile in NERD patients were comparable to healthy controls. Conclusions Levels of selected cytokines and Lyso-PAF AT were significantly higher in the esophageal mucosa of EE patients compared to NERD and control patients. This difference may explain the distinct inflammatory response occurring in EE patients’ mucosa. In contrast, since no significant differences existed between the levels of all mediators in NERD and control subjects, an inflammatory response does not appear to play a major role in the pathogenesis of the abnormalities found in NERD patients.

Altomare, A.; Ma, J.; Guarino, M.P.L.; Cheng, L.; Rieder, F.; Ribolsi, M.; Fiocchi, C.; Biancani, P.; Harnett, K.; Cicala, M.

2012-01-01

114

Robotic weld overlay coatings for erosion control. Quarterly technical progress report, October 1994--December 1994  

SciTech Connect

Research is presently being conducted to develop a criteria for selecting weld overlay coatings for erosion mitigation in Circulated Fluidized Beds. Initially, eleven weld overlay alloys were selected for erosion testing based upon a literature review. All eleven 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 second quarterly report. All selected coatings were erosion tested at 400{degree}C and their erosion resistance was evaluated by determining the steady state erosion rate. In addition, the microstructure of each coating was characterized before and after the erosion tests. The results of the tests are discussed in the third quarterly report. No correlations were found between room temperature hardness of the weld overlay coatings and their erosion resistance at elevated temperature. During the last quarter tensile tests were performed at 400{degree}C for the Ultimet, Inconel-625, 316L SS, C-22, and Stellite-6 wrought alloys. The erosion tests for these materials at 400{degree}C are in progress. The results of mechanical and erosion tests will be used to correlate mechanical properties of selected wrought alloys such as tensile toughness, ductility, strain hardening coefficient and yield strength to their erosion resistance at 400{degree}C. Also, the erosion behavior of the wrought alloys compared with similar weld alloys will be analyzed. The experimental procedure and results of the tensile tests are presented in this progress report.

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

1995-01-25

115

Timing of control activities in project planning  

Microsoft Academic Search

This paper deals with the timing of monitoring and control in project planning. The need for monitoring and control actions arise because projects are dynamic in nature and because of changing environments. The monitoring of the project deviations from the planned schedule due to environmental changes allows the generation of proper feedback to enable corrective actions. After having reviewed the

Massimo de Falco; Roberto Macchiaroli

1998-01-01

116

A controlled study of hand function in nodal and erosive osteoarthritis.  

PubMed

Hand function using a standardised test of activities of daily living was assessed in (a) 57 patients (53 female, four male; mean age 69 years) with established (that is, symptom onset greater than 10 years before) nodal generalised osteoarthritis (NGOA); (b) 10 patients (nine female, one male; mean age 70 years) with established erosive osteoarthritis (EOA); and (c) 52 matched controls (48 female, four male; mean age 71 years) with asymptomatic, clinically normal hands. Although significant differences between controls and patient groups were observed for individual tasks, only minor global impairment was seen, the worst function occurring in patients with EOA. There was no consistent correlation between tested aspects of hand function and extent of radiographic change assessed by summated graded score for separate osteoarthritic features in individual joints. In controls increasing age correlated with longer time to complete all tasks and weaker power grip; a similar, less pronounced correlation occurred in patients. Differences between controls and patients with NGOA were most apparent in younger subjects; in the elderly (greater than 80 years) hand function was essentially the same. This study shows good functional outcome for patients with NGOA, and suggests that the OA process is of little functional importance to the aging hand. PMID:2619358

Pattrick, M; Aldridge, S; Hamilton, E; Manhire, A; Doherty, M

1989-12-01

117

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

Microsoft Academic Search

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

M. O'Connor; W. McDavitt

2002-01-01

118

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

National Technical Information Service (NTIS)

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 angl...

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

1995-01-01

119

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...

120

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

121

Robotic weld overlay coatings for erosion control. Quarterly technical progress report, January 1995--March 1995  

SciTech Connect

Research is presently being conducted to develop a criteria for selecting weld overlay coatings for erosion mitigation in Circulated Fluidized Beds. During the last two quarters tensile tests were performed at 400{degrees}C for the Ultimet, Inconel-625, 316L SS, C-22, and Stellite-6 wrought alloys. Also, the erosion tests for these materials at 400{degrees}C were completed. The results of mechanical and erosion tests are used to correlate mechanical properties of selected wrought alloys such as tensile toughness, ductility, strain hardening coefficient and yield strength to their erosion resistance at 400{degrees}C. Preliminary results of correlations between erosion resistance of wrought alloys at 400{degrees}C and their mechanical properties are presented in this progress report.

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

1995-04-25

122

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

123

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

124

Planning flood control projects in urban areas  

Microsoft Academic Search

Planning and design of flood control projects invariably involves a consideration of sociological, economic, political and ecological factors in order to derive maximum benefits from the project. In urbanizing areas, this is often a rule rather than an exception where a project tends to have a variety of interrelated impacts on the environment. This paper presents the details of the

Nageshwar Rao Bhaskar; Vijay P. Singh

1988-01-01

125

Thermal Control System Automation Project (TCSAP).  

National Technical Information Service (NTIS)

Information is given in viewgraph form on the Space Station Freedom (SSF) Thermal Control System Automation Project (TCSAP). Topics covered include the assembly of the External Thermal Control System (ETCS); the ETCS functional schematic; the baseline Fau...

R. L. Boyer

1991-01-01

126

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...

127

Erosion by Wind: Modeling  

Technology Transfer Automated Retrieval System (TEKTRAN)

Models of wind erosion are used to investigate fundamental processes and guide resource management. Many models are similar in that - temporal variables control soil wind erodibility; erosion begins when friction velocity exceeds a threshold; and transport capacity for saltation/creep is proportion...

128

The paradox of project control  

Microsoft Academic Search

Purpose – This paper aims to explore a case study example of the decision-making process that occurs within complex organizations. It exposes a murky “zone” of decision making and action between the strategic vision set by senior management and the work of teams to realise projects. Design\\/methodology\\/approach – A case study from the experience of one of the authors is

Lynda Bourne; Derek H. T. Walker

2005-01-01

129

EFFECTS OF DEM SOURCE AND RESOLUTION ON WEPP HYDROLOGIC AND EROSION SIMULATION: A CASE STUDY OF TWO FOREST WATERSHEDS IN NORTHERN IDAHO  

Microsoft Academic Search

The recent modification of the Water Erosion Prediction Project (WEPP) model has improved its applicability to hydrology and erosion modeling in forest watersheds. To generate reliable topographic and hydrologic inputs for the WEPP model, carefully selecting digital elevation models (DEMs) with appropriate resolution and accuracy is essential because topography is a major factor controlling water erosion. Light detection and ranging

J. X. Zhang; J. Q. Wu; K. Chang; W. J. Elliot; S. Dun

130

Interdisciplinary on-site evaluation of stone bunds to control soil erosion on cropland in Northern Ethiopia  

Microsoft Academic Search

Since two decades, stone bunds have been installed in large areas of the Tigray Highlands, Northern Ethiopia, to control soil erosion by water. Field studies were conducted to quantify the effectiveness, efficiency, side effects and acceptance of stone bunds. Based on measurements on 202 field parcels, average sediment accumulation rate behind 3–21 year old stone bunds is 58tha?1year?1.The Universal Soil

Jan Nyssen; Jean Poesen; Desta Gebremichael; Karen Vancampenhout; Margo D’aes; Gebremedhin Yihdego; Gerard Govers; Herwig Leirs; Jan Moeyersons; Jozef Naudts; Nigussie Haregeweyn; Mitiku Haile; Jozef Deckers

2007-01-01

131

Assessment of gas turbine erosion. Volume 1. Assessment of available erosion data  

SciTech Connect

This project was designed to address the question of gas turbine tolerance in the particle laden environment of pressurized fluidized bed (PFB) combustion gas. The project objectives were to investigate previous gas turbine erosion tests, to design a turbine erosion test facility and to plan a long range test program for commercializing this gas turbine application. This first volume of a two volume report reviews experience in the US and Australia on gas turbine erosion in a pressurized fluidized bed-type environment. From this literature search it was concluded that successful operation of PFB powered turbines is obtainable. However, there is insufficient data available at this time to permit a prediction of turbine life to be made in this type of erosive/corrosive environment. Therefore, three types of erosion/corrosion experiments must be performed to completely establish turbine capabilities in particulate laden environments. The first should consist of well controlled experiments where the effects of blade shape, blade size, particle size, gas velocity, and other controllable parameters are established over a wide range. The second set of experiments should consist of combined erosion/corrosion rig experiments in which candidate materials will be screened for relative performance under a simulated PFBC environment. The final and critical experiment should be the testing of the proposed gas turbine under actual operating conditions for extended periods. (LCL)

Boericke, R.R.; Grey, D.A; Spriggs, R.R.; Hantman, R.G.; Kuo, J.T.; Tabakoff, W.; Hamed, A.

1980-04-01

132

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

SciTech Connect

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

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

1993-07-20

133

Tectonic uplift and climate controlling erosion along the Southern Himalayan Front  

NASA Astrophysics Data System (ADS)

The spatial and temporal evolution of rock uplift in active orogens provide valuable insights into the relations between surface and tectonic processes, and topography. A prime example is the humid western and central part of the southern Himalayan mountain front, where rainfall is high and evenly distributed. In the orographic rain shadow north of the Shillong Plateau (25N, 91E) located 250 km south of the eastern mountain front, annual rainfall decreases to 70% from west to east (i.e. 6m/a vs. < 1.7m/a). Other areas with low precipitation occur along the entire southern Himalayan front at elevations over 3000m, where moisture has fallen as rain at lower elevations. Along the entire southern Himalayan front, lithology, tectonic style and neotectonic activity do not vary strongly along strike. Therefore, substantial along-strike variations of topography possibly reflect local differences in uplift and climate-controlled erosion. Digital elevation models were used in an analysis of topography and channel gradients. Precipitation data are based on calibrated passive microwave data (SSMI) with a spatial resolution of 12.5 km2; DEMs along the Southern Himalayan Front were generated using the GTOPO30 data set. High-resolution topographic data (1:25,000, 1:50,000 and 1:100,000 maps) were used to characterize geomorphology in several areas. The N-S trending Sutlej Valley (32N, 78E) is drained by the antecedent Sutlej River which cuts through the Tethyan Himalaya, High and Lower Himalayan Crystalline, and the Lesser Himalaya. The Arun (27N, 87E) and Manas valleys (27.5N, 91.5E) have a similar lithology and geologic structures, but the latter lies within the orographic rain shadow of the Shillong Plateau. Significantly diverse topographic swath profiles that show steep slopes in high precipitation areas while gentler slopes dominate in dry areas. All sectors with evenly distributed high orographic precipitation and runoff to elevations of approximately 3000m have smooth channel gradients. Above this elevation, rainfall decreases dramatically and knickpoints exist. River profiles of bedrock channels draining these high areas have high steepness indices (a measure of profile gradient normalized to drainage area). This observation shows that despite active tectonism knickpoint formation in the topographically lower and more humid segments of the profiles is counteracted by high erosional capacity and incision. In contrast to the humid Himalayan front, river profiles in the rain shadow north of the Shillong Plateau occur in a comparable setting regarding lithology, tectonism, and elevation to rivers in the higher, more arid parts of the Himalayan front. The regions north of the Shillong Plateau receive between 15 and 40% of the amount of precipitation in the lower elevated western sectors. Behind the Shillong Plateau river profiles within the lower elevation regions (up to 3000 m) are steeper and characterized by pronounced knickpoints. This is thus similar to knickpoint formation in the more arid, higher elevation regions along the rest of the southern Himalayan front. The evolution of longitudinal river profiles in this region is therefore clearly influenced by an effective erosive climate in those sectors of the orogen, where precipitation is high. This is in line with preliminary results from fission-track thermochronology that indicate high denudation/uplift rates in sectors with high precipitation, moderate rates at elevations of about 3000m, and lower rates that characterize drier regions in excess of 3000m, as well as leeward sectors behind the Shillong Plateau.

Bookhagen, B.; Thiede, R.

2001-12-01

134

A controlled study of hand function in nodal and erosive osteoarthritis  

Microsoft Academic Search

Hand function using a standardised test of activities of daily living was assessed in (a) 57 patients (53 female, four male; mean age 69 years) with established (that is, symptom onset greater than 10 years before) nodal generalised osteoarthritis (NGOA); (b) 10 patients (nine female, one male; mean age 70 years) with established erosive osteoarthritis (EOA); and (c) 52 matched

M Pattrick; S Aldridge; A Manhire; M Doherty

1989-01-01

135

Effective and low cost erosion control of inactive coal storage piles  

Microsoft Academic Search

Erosion of coal stockpiles by wind and rain cost utilities thousands of dollars each year in lost fuel, coal pile maintenance and environmental equipment. The main problem at Nelson Unit 6 was loss due to frequent and heavy rains. Average yearly rainfall in that part of Louisiana is 56''. There is a definite ''rainy season'' in the winter months and

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

1983-01-01

136

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...

137

Infection control team workforce project  

Microsoft Academic Search

Many features of the NHS conspire to make workforce planning different and difficult. It is often integrated with other planning processes. There are few available guidelines for workforce configurations of infection control (IC) teams or evidence that assesses the effectiveness of different staffing configurations. A telephone survey of IC practice in four NHS trusts in England was undertaken to assist

C. Barrett; D. Hilder; J. Prieto

2008-01-01

138

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

NASA Astrophysics Data System (ADS)

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

Marsh, William M.

1990-09-01

139

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

140

Rock-type control on erosion-induced uplift, eastern Swiss Alps  

Microsoft Academic Search

There is growing evidence that Quaternary rock uplift in parts of the European Alps is a consequence of climate- and erosion-driven isostatic rebound. Contemporary rates of rock uplift U in the Swiss Alps show two distinctive dome-like peak regions that attain ~1.6 mm yr?1. We focus on the Alpenrhein catchment and its surroundings, where one of these peak regions spatially coincides

Oliver Korup; Fritz Schlunegger

2009-01-01

141

Use of cover crops in short rotation hardwood plantations to control erosion  

Microsoft Academic Search

This study was designed to test whether the cultivation of cover crops between tree rows in short-rotation woody crop (SRWC) plantations could reduce erosion. Sweetgum (Liquidambar styraciflua L.) seedlings were planted as the SRWC at a 1.5×3 m spacing. Four cover crops, annual ryegrass (Lolium multiflorum L. a winter annual grass); tall fescue (Festuca arundinacea L. a cool-season perennial grass); crimson

R. K. Malik; T. H. Green; G. F. Brown; D. Mays

2000-01-01

142

Runoff and erosion control with conservation tillage and reduced-input practices on cropped watersheds  

Microsoft Academic Search

The North Appalachian Experimental Watershed near Coshocton, OH was established in 1935 to develop, evaluate, and refine conservation practices that reduce runoff and erosion under the hilly, humid conditions of the northeastern United States. Small (0.5 to 1 ha), single-practice, gaged watersheds comprised of sandstone- and shale-derived residual soils are used to evaluate the interaction of management, climate, and soils.

M. J. Shipitalo; W. M. Edwards

1998-01-01

143

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...

144

Erosive osteoarthritis  

Microsoft Academic Search

Erosive osteoarthritis (EOA) is believed to be a clinically uncommon subset of generalized osteoarthritis (OA) characterized by a clinical course, which is frequently aggressive. The diagnosis of EOA is accepted only for patients meeting American College of Rheumatology clinical criteria for OA of the hand and showing radiographic aspects of articular surface erosions. Conditions to be considered in the differential

Leonardo Punzi; Roberta Ramonda; Paolo Sfriso

2004-01-01

145

Ogunquit Sand Dune Land Stabilization Measure Threshold to Main Resource Conservation and Development Project, York County, Maine.  

National Technical Information Service (NTIS)

The project proposes land stabilization consisting of restoring and stabilizing a 28-acre barrier dune through the placement of sand, plantings of vegetation, and the installation of erosion and pedestrian control measures. The action will reduce erosion ...

1972-01-01

146

Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion system. Final technical report  

SciTech Connect

Research is presented on erosion and corrosion of fluidized bed combustor component materials. The characteristics of erosion of in-bed tubes was investigated. Anti-corrosion measures were also evaluated.

Lee, Seong W.

1996-11-01

147

Greenidge MultiPollutant Control Project  

Microsoft Academic Search

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, NO, Hg, acid gases (SO, HCl, and HF), and particulate matter from smaller coal-fired electric generating units (EGUs). There are about 400 units in

Daniel Connell

2008-01-01

148

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...

149

Control research in windpower project 506259 utilization  

Microsoft Academic Search

Control systems design is analyzed for a windpowered generator with variable velocity. A project for a simplified wind-diesel construction, without a separate bearing was investigated. Yaw motion influence on the lateral motion of the tower was studied. This effect can be attenuated with a better design of the yaw servomotors. The rotor speed was used as out-signal, instead of the

Eskil Ulen

1989-01-01

150

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

PubMed

Shelterbelt system is one of the main components of cultivated slope land in rolling hill black soil region of Northeast China, which plays an important role in the control of gully erosion. Based on the Quickbird high-resolution remote sensing image and the digital elevation model (DEM), and combining with field survey data, this paper analyzed the effects of shelterbelt system in a small watershed of rolling hill black soil region in Heshan Farm of Heilongjiang Province on the control of gully erosion in the cultivated slope land, and put forward an optimized scheme for gully erosion control based on the features of gully erosion in the cultivated slope land and their relations with the distribution of the shelterbelt system. In the study area, the current distribution of the shelterbelt system promoted the occurrence and development of shallow gully and gully directly and indirectly. The proposed scheme for optimizing the distribution of the present shelterbelts included the adjustment of the direction of the shelterbelt perpendicular to the aspect of slope, the enhancement of the maintenance and regeneration of the shelterbelts to reduce the gaps of the shelterbelts, the increase of the shelterbelt number, and the decrease of the distances between shelterbelts. A method for calculating the shelterbelt number and the distances between the shelterbelts was also given. This study could provide scientific basis for the gully erosion control and the shelterbelts programming in the cultivated slope land of rolling hill black soil region. PMID:22803452

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

2012-04-01

151

Rainfall erosivity estimates from climate change multi-model, multi-scenario projections in southern Appalachian region  

NASA Astrophysics Data System (ADS)

The potential change in rainfall erosivity, RUSLE R-factor, in the southern Appalachian region was investigated for three future climate change scenarios A1F1, A1B and B1 from GISS-GCM III (NASA/GISS) global model data, by using MM5 (NCAR) regional climate model, and spatial temporal statistical downscaling techniques. R-factors for future dates (2049, 2050 and 2051) were estimated by daily precipitation data obtained from previous study which used GISS-GCM III model to provide initial and boundary conditions for MM5 regional climate model. The MM5 model ultimately produced regional data with 12 km resolution. Also these R-factors, which computed by MM5 data, were compared with the R-factors calculated based on daily weather series generated by means of a stochastic weather generator, CLIGEN and other spatial temporal statistical downscaling techniques. CLIGEN was calibrated to the rainfall for the period 1949 to 2000 and used to downscale the GCM output. Different comparisons were made between R-factors produced based on MM5 output data and those generated by statistical downscaling methods' output data. Results from this study can widely be used to assess potential future soil erosion conditions in this area, and the extent how effective current best management practices (BMP) may be in reducing soil erosion and sediment delivery. This method is also applicable to other areas.

Hoomehr, S.; Schwartz, J. S.; Lam, Y.; Fu, J. S.

2010-12-01

152

Overlandflow generation and surface erosion in Mongolia  

Microsoft Academic Search

In Mongolia, significant soil erosion is thought to be caused by overgrazing and unsuitable management. Soil erosion also make desertification, a key issue of environmental concern. However, very few field data are available on overland flow mechanism, soil erosion processes and amount and the desertification processes. The purpose of our research project (2001-2006) is to study and assess the state

Y. Onda; T. Nishikawa; H. Kato; Y. Tanaka; M. Tsujimura; G. Davaa; D. Oyunbaatar

2003-01-01

153

Final Report Project Title: Quantification of Runoff and Erosion on Semi-arid Grasslands following a Wildfire JFSP Project No: 03-2-3-11  

Microsoft Academic Search

Summary Background • The objectives of the study were to 1. quantify the effects of a wildfire on runoff and erosion and 2. parameterize the USFS ERMiT model for two ungrazed desert grassland sites in southeastern Arizona. • Rainfall simulator experiments were conducted on the two sites immediately after a wildfire and for subsequent years to document the recovery process.

J J Stone; G B Paige; D P Guertin; G Gottfried; S. Gunzel

154

Measuring the efficiency of project control using fictitious and empirical project data  

Microsoft Academic Search

Dynamic scheduling refers to the integration of three important phases in the life cycle of a project: baseline scheduling, schedule risk analysis and project control. In this paper, the efficiency of controlling a project is measured and evaluated using a Monte-Carlo simulation study on fictitious and empirical project data. In the study, the construction of a project baseline schedule acts

Mario Vanhoucke

155

Erosion kinetics of hydrolytically degradable polymers.  

PubMed Central

Degradable polymers are beginning to play an increasing role as materials for environmental and medical applications. Understanding factors that control erosion, such as bond cleavage and the dissolution and diffusion of degradation products, will be critical to the future development of these materials. Erosion kinetics, photomicroscopy, and infrared spectroscopy were used to understand the erosion mechanism of two families of degradable polymers, polyanhydrides and polyesters. Polyanhydrides exhibit behavior more characteristic of surface erosion, whereas the polyesters exhibit bulk erosion patterns. Control of erosion times from a few days to several years can be achieved by a judicious choice of monomer units and bond selection. Images

Tamada, J A; Langer, R

1993-01-01

156

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

PubMed

Soil erosion is one of the most serious environmental and public health problems, and such land degradation can be effectively mitigated through performing land use transitions across a watershed. Optimal land use management can thus provide a way to reduce soil erosion while achieving the maximum net benefit. However, optimized land use allocation schemes are not always successful since uncertainties pertaining to soil erosion control are not well presented. This study applied an interval-parameter fuzzy two-stage stochastic programming approach to generate optimal land use planning strategies for soil erosion control based on an inexact optimization framework, in which various uncertainties were reflected. The modeling approach can incorporate predefined soil erosion control policies, and address inherent system uncertainties expressed as discrete intervals, fuzzy sets, and probability distributions. The developed model was demonstrated through a case study in the Xiangxi River watershed, China's Three Gorges Reservoir region. Land use transformations were employed as decision variables, and based on these, the land use change dynamics were yielded for a 15-year planning horizon. Finally, the maximum net economic benefit with an interval value of [1.197, 6.311] × 10(9) $ was obtained as well as corresponding land use allocations in the three planning periods. Also, the resulting soil erosion amount was found to be decreased and controlled at a tolerable level over the watershed. Thus, results confirm that the developed model is a useful tool for implementing land use management as not only does it allow local decision makers to optimize land use allocation, but can also help to answer how to accomplish land use changes. PMID:23851701

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

2013-07-14

157

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

158

Reduction of Soil Erosion on Forest Roads  

Microsoft Academic Search

Results of onsite erosion control work from across the United States provide estimates of the amount of erosion reduction on forest roads from various treatments. Supplementary information includes the effects of slope gradient, soil characteristics, and ground cover. Estimates of sediment travel below fillslopes can be made, together with the combined effect of erosion control treatments of the running surface,

Burroughs Jr. Edward R; John G. King

1989-01-01

159

Erosive osteoarthritis.  

PubMed

Erosive osteoarthritis (EOA) is believed to be a clinically uncommon subset of generalized osteoarthritis (OA) characterized by a clinical course, which is frequently aggressive. The diagnosis of EOA is accepted only for patients meeting American College of Rheumatology clinical criteria for OA of the hand and showing radiographic aspects of articular surface erosions. Conditions to be considered in the differential diagnosis include primarily nodal generalized OA, psoriatic arthritis and rheumatoid arthritis. It is possible to find erosive changes resembling EOA in endocrine diseases, microcrystal-induced diseases, chronic renal diseases, autoimmune diseases and others. Despite the absence of a clear etiology, immunogenetic studies are useful in identifying a possible predisposition to developing EOA in some subjects. No definitive therapeutic approach to EOA has been reported. It is reasonable to assume that in the presence of a symptomatic EOA our therapeutic approach should differ from that used for common, nodal, non-EOA. PMID:15454130

Punzi, Leonardo; Ramonda, Roberta; Sfriso, Paolo

2004-10-01

160

Recurrent erosion of the cornea  

Microsoft Academic Search

Altogether, 80 patients aged between 24 and 73 years with recurrent erosion of the cornea have been studied and compared with a control group of 200. The patients' erosions were divisible into macroform and microform types. The macroform occurred in 10%, the microform in 56%, and both types in the same patients in 31%. The macroform was more commonly related

N. Brown; A. Bron

1976-01-01

161

Financial appraisal of date-frond mat fence systems for wind erosion control and sand dune stabilization in the arid region of the United Arab Emirates  

Microsoft Academic Search

A discounted cash flow model was employed to assess the viability of four wind barrier systems. The systems were utilized for wind erosion control and sand dune stabilization in the Al-Ain region of the United Arab Emirates. These systems consisted of four densities of date-frond mat fences erected in the form of checker board grids between rows of two local

Y. T. Gumaa; I. Haffar; M. A. Al-Afifi

1998-01-01

162

VALIDATION OF WEPS EROSION PREDICTIONS FOR SINGLE WIND EVENTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

As part of the Global Change and Terrestrial Ecosystems Soil Erosion Network (GTE-SEN) wind erosion model validation project, we compared observed soil loss with simulated soil loss predictions for 46 individual storms using the erosion submodel of the Wind Erosion Prediction System (WEPS). The ex...

163

Mulching Practice in a Semi-Arid Zone of Nigeria for Soil Erosion Control and Grain Yield of Maize  

Microsoft Academic Search

Water erosion is a major factor degrading soils of the Nigerian semi-arid ecoregions, and making agriculture less sustainable. For example, soil erosion in the Northern Guinea savanna ecozones of Nigeria is prominent in cultivated areas during the early part of the rain-fed crop production season, when most soil surfaces are bare. In order to estimate the magnitude and timing of

A. C. Odunze

2002-01-01

164

Hydraulic erosion of cohesive riverbanks  

NASA Astrophysics Data System (ADS)

This study identifies and assesses the controls on hydraulic erosion of cohesive riverbanks on a 600-m reach of an urban ephemeral stream with active bank erosion. We examined hydraulic bank erosion by separating estimated bank shear stress into four properties: magnitude, duration, event peak, and variability. The values of these independent variables were used as a bank erosion context at three transects. Stepwise regression showed that the event peak (maximum peak) of excess shear stress best predicts cohesive bank erosion at the two transects with moderate critical shear stresses (1.93-4.08 N/m 2), while the variability (all peaks) of excess shear stress best predicts erosion at the transect with low critical shear stress (0.95 N/m 2). These results suggest that the amount of hydraulic erosion of cohesive riverbanks is dictated by flow peak intensities. Finally, the results of this study were combined with results from previous bank erosion studies to produce a conceptual model for estimating bank erosion rates based on their silt-clay content.

Julian, Jason P.; Torres, Raymond

2006-06-01

165

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

166

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

PubMed

Fugitive dust from eroding land poses risks to environmental quality and human health, and thus, is regulated nationally based on ambient air quality standards for particulate matter with mean aerodynamic diameter < or = 10 microm (PM10) established in the Clean Air Act. Agricultural straw has been widely used for rainfall-induced erosion control; however, its performance for wind erosion mitigation has been less studied, in part because straw is mobile at moderate wind velocities. A wood-based long-strand material has been developed for rainfall-induced erosion control and has shown operational promise for control of wind-induced erosion and dust emissions from disturbed sites. The purpose of this study was to evaluate the efficacy of both agricultural straw and wood-strand materials in controlling wind erosion and fugitive dust emissions under laboratory conditions. Wind tunnel tests were conducted to compare wood strands of several geometries to agricultural wheat straw and bare soil in terms of total sediment loss, PM10 vertical flux, and PM10 loss. Results indicate that the types of wood strands tested are stable at wind speeds of up to 18 m s(-1), while wheat straw is only stable at speeds of up to 6.5 m s(-1). Wood strands reduced total sediment loss and PM10 emissions by 90% as compared to bare soil across the range of wind speeds tested. Wheat straw did not reduce total sediment loss for the range of speeds tested, but did reduce PM10 emissions by 75% compared to a bare soil at wind speeds of up to 11 m s(-1). PMID:19141803

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

2009-01-13

167

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

168

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

169

Managing runoff, water quality and erosion in peatland forestry by peak runoff control  

Microsoft Academic Search

Retention of stormwater can in theory reduce peak flows, sediment and nutrient transport. This study presents results of peak runoff control (PRC) as a water protection method to decrease sediment and nutrient loads from drained peatland forestry in boreal conditions. Peak runoff rate and peak concentrations were reduced. The PRC method reduced suspended solids (SS) load (86%) by reducing flow

Hannu Marttila; Bjørn Kløve

2010-01-01

170

Postfire Seeding for Erosion Control: Effectiveness and Impacts on Native Plant Communities  

Microsoft Academic Search

Large, high-severity wildfires remove vegetation cover and expose mineral soil, ofen causing ero- sion and runoff during postfire rain events to increase dramatically. Land-management agencies in the United States are required to assess site conditions after wildfire and, where necessary, implement emergency water- shed rehabilitation measures to help stabilize soil; control movement of water, sediment, and debris; prevent permanent impairment

JAN L. BEYERS

2004-01-01

171

Beach erosion rates and the National Flood Insurance Program  

NASA Astrophysics Data System (ADS)

Thirty of the nation's 50 states have coastlines on the Atlantic and Pacific oceans, the Gulf of Mexico, and the Great Lakes. These 30 states contain approximately 85% of the nation's population, and about half of this population resides in the coastal zone. Continued population growth is projected in the future, with a greatly increasing demand for beachfront development. At present, there is considerable public concern over coastal erosion, erosion control measures, and land use regulations [National Research Council, 1990].Beach erosion is a significant and growing national problem. The National Shoreline Study, conducted by the U.S. Army Corps of Engineers in 1971, was the first national appraisal of shore erosion problems. Significant erosion was found to occur along 43% of the U.S. shoreline if Alaska is excluded. Other large sections of sandy shoreline are also eroding, but the U.S. Army Corps of Engineers categorized it as noncritical erosion largely because of the lack of immediate threat to buildings and infrastructure at that time.

Leatherman, Stephen P.; Dean, Robert G.

172

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

2013-07-16

173

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

174

The impact on project success of using technology in modern project planning and control  

Microsoft Academic Search

This paper examines the impact the use of technological tools for project planning and control have on project success. The paper is based on data and conclusions from two earlier international studies involving a wide range of project types and respondents with different stakeholder perspectives. The first study concluded that evaluating project success tended to use rather narrowly focused measures

Svein-Arne Jessen

2011-01-01

175

Erosion induced controllable release of gliclazide encapsulated inside degradable polymeric particles.  

PubMed

The microphase inversion of water-insoluble poly(L-lactide), "poly[(L-lactide)-co-glycolide] and polylactide-block-poly(ethylene oxide)-block-polylactide from THF to water can result in narrowly distributed stable particles. Gliclazide, a commercial drug, can be encapsulated inside during the process. The formation and degradation of such particles was studied by laser light scattering. In comparison with the corrosion of a bulk material, the degradation of each particle is so fast that we only detect the decrease of the particle number, not the corrosion of individual particles. Therefore, the degradation is a "one-by-one" random process, just like the chemical reaction of molecules in solution. The disappearing rate of the particle number is nearly independent of time, ideal for the controlled release of drugs encapsulated inside. The amount of encapsulated gliclazide depends on the copolymer's hydrophobicity (composition), while the releasing rate mainly is, directly related to the disappearing rate of the particles. The correlation between the fluorescence intensity and the degradation was used to study the kinetics of gliclazide releasing. The releasing pattern is controllable with a proper choice of the drug loading, copolymer composition, pH and temperature. PMID:15468221

Zhao, Yue; Chen, Wenna; Cai, Qing; Wang, Shenguo; Bo, Jun; Wu, Chi

2004-03-15

176

Predicting sheetwash and rill erosion over the Australian continent  

Microsoft Academic Search

Soil erosion is a major environmental issue in Australia. It reduces land productivity and has off-site effects of decreased water quality. Broad-scale spatially distributed soil erosion estimation is essential for prioritising erosion control programs and as a component of broader assessments of natural resource condition. This paper describes spatial modelling methods and results that predict sheetwash and rill erosion over

Ian P. ProsserA; Chris J. MoranA; John C. GallantA; Janelle G. StevensonA

177

A method to measure clinical erosion: the effect of orange juice consumption on erosion of enamel  

Microsoft Academic Search

Objective: Acidic soft drinks are frequently implicated in dental erosion, but there are limited supporting data. Research is problematic due to the insidious nature of erosion and accuracy in assessing tissue loss. The aim of this study was to develop and validate, using a negative control, a model to accurately measure erosion in situ due to a single aetiological agent

N. X. West; A. Maxwell; J. A. Hughes; D. M. Parker; R. G. Newcombe; M. Addy

1998-01-01

178

Assessment of gas turbine erosion. Volume 1. Assessment of available erosion data  

Microsoft Academic Search

This project was designed to address the question of gas turbine tolerance in the particle laden environment of pressurized fluidized bed (PFB) combustion gas. The project objectives were to investigate previous gas turbine erosion tests, to design a turbine erosion test facility and to plan a long range test program for commercializing this gas turbine application. This first volume of

R. R. Boericke; D. A Grey; R. R. Spriggs; R. G. Hantman; J. T. Kuo; W. Tabakoff; A. Hamed

1980-01-01

179

Measurement of soil water erosion in Africa: the potential support provided by nuclear techniques  

NASA Astrophysics Data System (ADS)

Conservation of soil and water resources has become a major agronomic and environmental concern. Degradation phenomena, such as erosion, desertification and salinization affect 65% of soils worldwide. Soil degradation is currently affecting 1.9 billion hectares and is increasing at a rate of 5 to 7 million hectares each year. Almost 50% of 133 million ha degraded soils by overexploitation are located in Africa. The degradation of arable lands affects especially arid areas with poor vegetation cover and tropical areas with high intensity rainfall. Water erosion is by far the most common type of land degradation in Africa. Accelerated erosion decreases soil productivity, increases sedimentation and is related to environmental pollution problems in agro-ecosystems. To control soil erosion there is a need to assess the impact of major land use and the effectiveness of specific soil conservation technologies using various approaches. Effective erosion control starts with the knowledge of soil erosion rates and mechanisms. In Africa, various research projects on water erosion have been implemented involving different conventional techniques such as remote sensing, morphometric investigation, sediment transport models and sediment loading measurements, runoff plots and rainfall erosivity measurements. However, only limited quantitative data on erosion and sedimentation magnitude under African agroenvironmental condition are available. Traditional monitoring and modeling techniques for soil water erosion require many parameters and years of measurements of (inter-annual and mid-term) climatic variability and cropping practices. Conventional erosion and sedimentation methods are limited to provide mid-term trends in soil erosion, however fallout radionuclides (FRN) - e.g. 137-Cs, 210-Pb and 7-Be - have proven to be very powerful tools to trace soil erosion and sedimentation within the landscape from plot to basin scale. FRN techniques allow the estimation of short and medium-term rates of soil redistribution integrating land use and climatic variability. FRN can be used to obtain average soil redistribution figures for time scales ranging from single events to many years of erosion processes, while direct erosion measurements are related to single rainfall events or rather short periods of time (e.g. erosion plots). FRN methodologies integrate all processes involving soil particle movements and allow quantification of soil loss and deposition associated with sheet erosion, which is difficult to assess using other conventional approaches. Sampling of individual points allows spatially distributed information on rates and patterns of soil redistribution. Also, one of the main advantages of the FRN is that time-consuming, costly maintenance, long-term monitoring programme and installations required by non isotopic and conventional methods can be avoided. Soil sampling can be completed in a short time and the site disturbance during sampling is minimal and does not interfere with seeding and cultivation operations. Since radionuclide-based measurements also provide information on the spatial distribution of erosion/sedimentation rates, they can be used to validate the results of distributed soil erosion models. The main purpose of this contribution is to present a synthetic overview of the usefulness in using nuclear techniques in Africa to investigate medium and short term soil erosion and sedimentation processes. Also, the advantages and limitations in using the FRN (137-Cs, 210-Pb and 7-Be) as soil redistribution tracer will be compared to other conventional water erosion methods. Keywords: Water erosion, conventional erosion assessment and measurement, nuclear techniques.

Mabit, Lionel

2010-05-01

180

THE UNITED STATES EXPERIENCE IN CONTROLLING EROSION: THE INVOLVEMENT OF GOVERNMENT, RURAL VS. URBAN CONTROLS, AND THE BLURRING OF THOSE DIFFERENCES  

Microsoft Academic Search

The United States history and experience in concern for erosion and its concequences is an interesting technical and public policy study. Starting with the nation's settlement and founding in the 1700's, there are papers and texts that demonstrate our earliest settlers and scientists were aware of the problems caused by erosion as man disturbed the soil, and were interested in

John W. Peterson

181

Large Scale Predictions of Potential Post-fire Erosion  

NASA Astrophysics Data System (ADS)

High-severity wildfires are of increasing concern because of their potential for initiating flash floods and surface erosion, degrading water quality, and reducing reservoir capacity. In many areas fire suppression has increased fuel accumulations and hence the potential for high-severity wildfires. Land management agencies are undertaking programs to reduce fuel loadings and the associated risk of high-severity wildfires, but the areas needing treatment greatly exceed the available funding. It is therefore necessary to determine which areas should have a higher priority for such treatments. Similarly, when wildfires do occur there is an immediate need to determine which areas should have the highest priority for post-fire rehabilitation treatments. One criterion for allocating treatments is the potential risk of post-fire erosion, but to be effective this assessment needs to be carried out at a broad scale. This paper presents a procedure and initial results for predicting spatially-explicit, post-fire erosion risks at the hillslope scale for forest and shrub lands across the western U.S. Our approach utilizes existing physical models and datasets in a GIS framework. The model for predicting erosion is GeoWEPP, the Geographical interface for the Water Erosion Prediction Project (WEPP). The primary inputs for GeoWEPP include climate, topography, soils, and land cover/land use. Daily climate inputs were generated with Cligen, which is a stochastic weather generator distributed with WEPP. A 30-m digital elevation model, STATSGO-derived soils data, and vegetation cover were obtained from the U.S. Forest Service's LANDFIRE project. Since recent research has shown that percent ground cover is a dominant control on post-fire erosion rates, we generated a spatially-explicit map of post-fire ground cover by first using historic weather data to determine the 1000-hr fuel moisture values when fuel conditions were at 98-100% ERC (Energy Released Component). These fuel moisture values were fed into FOFEM (First Order Fire Effects Model) to obtain spatially-explicit predictions of percent ground cover, and this provided the additional land cover/land use information needed by GeoWEPP. The predicted erosion rates are comparable to measured values in the Colorado Front Range, but are much too high for the higher rainfall areas along the Pacific Coast. This pattern indicates that precipitation is having a pre-dominant effect on predicted post-fire erosion rates, especially in areas that are projected to burn at low severity. Hence the predicted erosion rates will be most useful in relative terms at the local and possibly regional scale, while comparisons between regions may be of more limited validity.

Miller, M. E.; MacDonald, L. H.

2005-12-01

182

The relationship between planning & control risk and ERP project success  

Microsoft Academic Search

Enterprise resource planning (ERP) projects have often been found to be complex and risky to implement in business enterprises. Thus, an understanding of the risk factors inherent in implementing ERP projects can help to reduce the incidence of failure. The results not only revealed which planning & control risk factors are associated with ERP project implementation, but also showed that

W.-H. Tsai; S.-J. Lin; W.-R. Lin; J.-Y. Liu

2009-01-01

183

Ensuring smooth sailing: an overview of project planning and control  

Microsoft Academic Search

The discipline of project management has evolved slowly over the last century; and it has only recently been discovered and embraced by the business community at large. Project planning and control is one aspect of project management. It is concerned with providing the answers to five basic questions: what am I producing (outputs\\/goals); how do I get the work done

P. R. Seesing

1995-01-01

184

Hail Control. Operative and Scientific Research Project.  

National Technical Information Service (NTIS)

Contents: Physical basis of artificial modification of clouds; Development of hail control in the world; Characteristics of the hail control system developed in the U.S.S.R.; Development of hail control in Yugoslavia; Professional-scientific definition of...

D. Radinovic

1972-01-01

185

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

186

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

187

Tectonic and climatic controls on rift escarpments: Erosion and flexural rebound of the Dhofar passive margin (Gulf of Aden, Oman)  

Microsoft Academic Search

We investigate the respective roles of climatic parameters and the flexural rigidity of the lithosphere in the erosion history and behavior of two adjacent rift escarpments along the northern coast of the Gulf of Aden, in Oman. At this 25 Myr old passive margin, we define a type 1 scarp, which is high, sharp-crested and has retreated 25–30 km inland

C. Petit; M. Fournier; Y. Gunnell

2007-01-01

188

Tectonic and climatic controls on rift escarpments: Erosion and flexural rebound of the Dhofar passive margin (Gulf of Aden, Oman)  

Microsoft Academic Search

We investigate the respective roles of climatic parameters and the flexural rigidity of the lithosphere in the erosion history and behavior of two adjacent rift escarpments along the northern coast of the Gulf of Aden, in Oman. At this 25 Myr old passive margin, we define a type 1 scarp, which is high, sharp-crested and has retreated 25-30 km inland

C. Petit; M. Fournier; Y. Gunnell

2007-01-01

189

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

NASA Astrophysics Data System (ADS)

The interplay between topography and Indian summer monsoon circulation profoundly controls precipitation distribution, sediment transport, and river discharge along the Southern Himalayan Mountain Front (SHF). The Higher Himalayas form a major orographic barrier that separates humid sectors to the south and arid regions to the north. During the Indian summer monsoon, vortices transport moisture from the Bay of Bengal, swirl along the SHF to the northwest, and cause heavy rainfall when colliding with the mountain front. In the eastern and central parts of the Himalaya, precipitation measurements derived from passive microwave analysis (SSM/I) show a strong gradient, with high values at medium elevations and extensive penetration of moisture along major river valleys into the orogen. The end of the monsoonal conveyer belt is near the Sutlej Valley in the NW Himalaya, where precipitation is lower and rainfall maxima move to lower elevations. This region thus comprises a climatic transition zone that is very sensitive to changes in Indian summer monsoon strength. To constrain magnitude, temporal, and spatial distribution of precipitation, we analyzed high-resolution passive microwave data from the last decade and identified an abnormal monsoon year (AMY) in 2002. During the 2002 AMY, violent rainstorms conquered orographic barriers and penetrated far into otherwise arid regions in the northwest Himalaya at elevations in excess of 3 km asl. While precipitation in these regions was significantly increased and triggered extensive erosional processes (i.e., debris flows) on sparsely vegetated, steep hillslopes, mean rainfall along the low to medium elevations was not significantly greater in magnitude. This shift may thus play an important role in the overall sediment flux toward the Himalayan foreland. Using extended precipitation and sediment flux records for the last century, we show that these events have a decadal recurrence interval during the present-day monsoon circulation. Hence, episodically occurring AMYs control geomorphic processes primarily in the high-elevation arid sectors of the orogen, while annual recurring monsoonal rainfall distribution dominates erosion in the low- to medium-elevation parts along the SHF.

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

2005-02-01

190

A methodology for project control through risk analysis: the case of a pipeline project  

Microsoft Academic Search

Projects exposed to uncertainties can be effectively controlled with the application of risk analysis during the planning stages. The Analytic Hierarchy Process (AHP), can be used to analyse risks associated with such projects. The results from risk analysis along with activity analysis are combined to develop a logical contingency allowance for the project through the application of probability theory. Effective

S. O. Ogunlana; M. T. Tabucanon; P. Dey

1993-01-01

191

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

192

Project Control for Healthcare Information Systems Initiatives  

Microsoft Academic Search

If left unchecked, trends in healthcare will overwhelm our tax base. Information and communication technologies (ICTs) have the potential to improve quality of care and lower costs. They also have the potential to deliver new forms of care that will save money in the long term. The problem is that information technology projects are difficult to implement. This paper uses

Lorne D. Booker; H. Trabulsi

2009-01-01

193

Case Study Projects in an Undergraduate Process Control Course  

Microsoft Academic Search

In this paper we present a case study approach toteaching undergraduate chemical process control.During the last half of a one-semester chemicalprocess control course, the students work in threepersonteams on a multivariable control project thatthey have selected from a choice of five processes.Each project is advised by a different member of aninstructional team (instructor, course teachingassistant or a graduate student studying

B. Wayne Bequette; Kevin D. Schott; Vinay Prasad; Venkatesh Natarajan

1998-01-01

194

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

Microsoft Academic Search

Wind erosion is a phenomenon that is reasonably common in regions where dry winds blow. For the most part, these regions correspond\\u000a to the dry lands; areas where the soil, generally, is dry and shifting and lacks vegetation for most of the year. The winds\\u000a are sufficiently strong to lift and move sands and soil particles. The repeated removal of

M. R. Ekhtesasi; A. Sepehr

2009-01-01

195

Efficacy and safety of esomeprazole compared with omeprazole in GERD patients with erosive esophagitis: a randomized controlled trial  

Microsoft Academic Search

OBJECTIVE:In patients with gastroesophageal reflux disease (GERD), esomeprazole, the S-isomer of omeprazole, has demonstrated pharmacological and clinical benefits beyond those seen with the racemic parent compound. This study was designed to further evaluate the efficacy and tolerability of esomeprazole relative to that of omeprazole in healing erosive esophagitis and resolving accompanying symptoms of GERD.METHODS:Esomeprazole 40 mg was compared with omeprazole

Joel E. Richter; Peter J. Kahrilas; John Johanson; Paul Maton; Jeffrey R. Breiter; Clara Hwang; Victoria Marino; Bernard Hamelin; Jeffrey G. Levine

2001-01-01

196

Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion (FBC) system. Quarterly report  

SciTech Connect

This technical report summarizes the research work performed and progress achieved during the period of October 1, 1995 to December 31, 1995. A series of material wastage tests was carried out on cooled AISI 1018 steel and three thermal-sprayed coating specimens at an elevated environmental temperature (3000{degrees}C) using a nozzle type erosion tester. Test conditions simulated the erosion conditions at the in-bed tubes of fluidized combustors (FBCs). Angular silica quartz particles of average size 742 {micro}m were used for erodent particles for tests at an impact angle of 30{degrees}, at a particle velocity of 2.5 m/s for exposure periods up to 96 hours. The specimens were water-cooled on backside. Material wastage rates were determined from thickness loss measurements of specimens. Test results were compared with material wastage test results from testing isothermal specimens. The morphology of specimens was examined by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). It was found that the cooled specimens had greater material wastage than that of the isothermal specimens. The material wastage rate of cooling specimen for AISI 1018 was greater than that for thermal- sprayed coatings. The success in reduction of erosion wastage by cooled-coating specimens was related to the coatings, composition and morphology.

Lee, Seong W.

1996-01-01

197

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

198

Coastal erosion and the cape hatteras lighthouse  

Microsoft Academic Search

The famous Cape Hatteras Lighthouse is threatened with destruction by an eroding coastline. Recent attempts to control the\\u000a erosion have reduced but not stopped it The natural erosion trend for 41 km of coast from Rodanthe to Cape Hatteras was determined,\\u000a based on 94 years of survey records from 1852 to 1946 At the lighthouse, the natural erosion rate is

Lorance D. Lisle; Robert Dolan

1984-01-01

199

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

200

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

201

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.

202

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...

203

Project systems of procrastinators: a personal project-analytic and action control perspective  

Microsoft Academic Search

The purpose of this research was to explore the Personal Project Systems (e.g., Little, 1983) of state-oriented and action-oriented individuals. Eighty-four female and 57 male undergraduates enrolled in an introductory psychology class completed Little’s Personal Projects Analysis (e.g., 1983) and Kuhl’s Action Control Scale (Kuhl, 1994). The results from the present study revealed that the project systems of state-oriented individuals

Allan Blunt; Timothy A. Pychyl

2005-01-01

204

Modeling soil erosion and transport on forest landscape  

Treesearch

Steamboat Springs, CO: International Erosion Control Association: 189-198. ... This system has the capability to predict long-term soil erosion and sediment ... the total mass of sediment moving from each cell to the nearest stream network.

205

15 CFR 923.25 - Shoreline erosion/mitigation planning.  

Code of Federal Regulations, 2013 CFR

...erosion/mitigation planning. (a) The management program must include a planning process for assessing the effects of, and studying and evaluating ways to control, or lessen the impact of, shoreline erosion, including potential impacts of sea...

2013-01-01

206

Electrical control features of the Bonneville hydroelectric project  

SciTech Connect

With the addition of the second hydroelectric powerhouse at the Bonneville project a method of control of the second powerhouse needed to be designed. The development of this control will be explained by general discussion. A review of the method of integrating the second powerhouse control with the first powerhouse control will present a unique approach taken to the problem. The material presented should provide useful information to anyone confronted with a similar problem.

Brockschink, S.R.

1982-12-01

207

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

208

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...

209

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...

210

EFFECTS OF FIELD SIZE ON WIND EROSION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Field shape, size, and orientation are often manipulated to aid in wind erosion control. The effectiveness of these practices depends on both field surface conditions and the local wind climatology. Field surfaces are generally assumed to be uniform at the beginning of erosion events, but develop ...

211

Bank erosion processes on Lower Mekong River  

Microsoft Academic Search

Bank erosion processes are modelled by employing fully coupled fluvial erosion and mass-wasting models to identify the key controls on bank retreat at several study sites, and across a wide range of flows on a globally significant monsoonal river, the Mekong. With respect to mass-wasting processes, a limit equilibrium bank stability analysis, combined with a finite element seepage analysis, are

H. Q. Trieu; P. A. Carling; S. E. Darby

2009-01-01

212

Erosion Condition Classification System.  

National Technical Information Service (NTIS)

This technical note has been designed to (1) present a revised system for classifying the degree of accelerated erosion condition and (2) to give guidance on the field method for measuring the erosion condition class for a sample area.

R. D. Clark

1980-01-01

213

Mechanism of Electrical Erosion.  

National Technical Information Service (NTIS)

High-speed photography, in agreement with experiments on the investigation of erosion as a function of pulse length, has indicated that the ejection of metal from the electrodes during electrical erosion takes place during discharge, no metal being ejecte...

A. S. Zingerman

1965-01-01

214

Modeling soil erosion on steep sagebrush rangeland before and after prescribed fire  

Microsoft Academic Search

Fire in sagebrush rangelands significantly alters canopy cover, ground cover, and soil properties which influence runoff and erosion processes. Runoff can be generated more quickly and in larger volume following fire resulting in increased risk of severe erosion and downstream flooding. The Water Erosion Prediction Project (WEPP) model was developed to predict erosion on cropland, forest, and rangeland. WEPP is

Corey A. Moffet; Frederick B. Pierson; Peter R. Robichaud; Kenneth E. Spaeth; Stuart P. Hardegree

2007-01-01

215

Erosion-Corrosion-Wear Program.  

National Technical Information Service (NTIS)

Progress is reported concerning erosion mechanics in ductile metals, erosion of thin scales, erosion mechanics in brittle solids, effect of particle characteristics on erosion of ductile material, and the halo effect in jet impingement solid particle eros...

A. V. Levy

1980-01-01

216

Tectonic and climatic controls on rift escarpments: Erosion and flexural rebound of the Dhofar passive margin (Gulf of Aden, Oman)  

NASA Astrophysics Data System (ADS)

We investigate the respective roles of climatic parameters and the flexural rigidity of the lithosphere in the erosion history and behavior of two adjacent rift escarpments along the northern coast of the Gulf of Aden, in Oman. At this 25 Myr old passive margin, we define a type 1 scarp, which is high, sharp-crested and has retreated 25-30 km inland from its master fault, and a type 2 scarp, which exhibits a more rounded profile, lower relief, and still coincides with its mapped normal fault trace. Since about 15 Ma, the margin has been seasonally affected by monsoon precipitation but with contrasting effects at the type 1 and type 2 escarpments depending on the position of the Intertropical Convergence Zone in the geologic past: during peak monsoon conditions, both scarps experienced heavy rainfall and runoff, whereas during monsoon-starved conditions (such as today), the type 2 scarp experienced a foggy, moist climate while the type 1 scarp remained much drier. In order to assess the relative effects of climate and flexural parameters on the present-day morphology of the Dhofar margin, we present one-dimensional numerical models of erosion and flexure along two profiles representative of the type 1 and type 2 scarps. Unlike most surface process models previously published, where present-day topography is the only criterion by which to evaluate the quality of model outputs, model behavior here is additionally constrained by independent estimates of denudation provided by geological cross sections, well-defined fault traces, and other stratigraphic markers. The best fitting models indicate that the type 1 escarpment formed under relatively arid climatic conditions and was affected by significant erosion, recession and flexural uplift due to a low (7 km) effective elastic thickness. In contrast, the morphology of the type 2 fault scarp was smoothed by a more humid climate, but a high effective elastic thickness (?15 km) prevented it from uplifting or receding. In addition, we show that the sedimentary load acting at the foot of the escarpments exerts significant influence on their morphological evolution, though this parameter is often neglected in other scarp evolution models.

Petit, C.; Fournier, M.; Gunnell, Y.

2007-03-01

217

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...

218

Road Map for Future Controller Interface Device Projects.  

National Technical Information Service (NTIS)

The Controller Interface Device (CID) has been a major focus of the NIATT Center for Traffic Operation and Controls for the past several years, leading to the commercial release of the CID II. Several projects related to further CID development have since...

B. K. Johnson Z. Li T. R. Cuffn

2005-01-01

219

Decentralized robust control via quadratically invariant model projection  

Microsoft Academic Search

We propose a computational approach to systematically find decentralized H? suboptimal controllers for general unstructured models. Exploiting the quadratically invariant model projection and the classical robust control synthesis techniques, we show that the original nonconvex problem can be conservatively solved by a series of convex optimization problems.

Jong-Han Kim; Sanjay Lall; Walter Merrill; Alireza Behbahani

2011-01-01

220

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...

221

[JICA Leprosy Control and Basic Health Services Project in Myanmar].  

PubMed

Japan International Cooperation Agency (JICA) implemented a 5-year long bilateral technical cooperation project, "Leprosy Control and Basic Health Services Project" in Myanmar. The project was implemented by National Leprosy Control Program, Department of Health with close technical collaboration of JICA experts mainly from International Medical Center of Japan (IMCJ) and National Sanatoriums of leprosy in Japan. It accelerated to achieve the elimination of leprosy at national level, which was declared in January 2003, and at sub-national level onward. It also developed the appropriate technologies for prevention of disability and prevention of worsening of disability (POD/POWD), which were introduced in 9 townships as a pilot service program. The Government stratified the POD/POWD services as a national program since 2005 by taking up the former pilot area to start with. The project also strengthened the function of referral system of leprosy control (Diagnosis and treatment), POD/POWD and physical rehabilitation. Beside leprosy, the project conducted a series of refresher trainings for primary health care givers, Basic Health Service Staff (BHS), of project areas (48 townships) to improve the services on tuberculosis, Malaria, Leprosy, Trachoma and HIV/AIDS for 3 years (2001-2003), which was evaluated in 2004. It contributed to improve the services at township level hospitals in procurement of audio-visual equipments and in conducting microscope training on leprosy, Malaria and tuberculosis at project areas. PMID:16248354

Ishida, Yutaka; Hikita, Kazuo

2005-09-01

222

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

Code of Federal Regulations, 2013 CFR

...participants in a scrapie control pilot project by recording the requirements...waived in the scrapie control pilot project plan: (1) The determination...animal, if the scrapie control pilot project plan contains testing or other procedures that...

2013-01-01

223

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

Code of Federal Regulations, 2013 CFR

...participants in a scrapie control pilot project by recording the requirements...waived in the scrapie control pilot project plan: (a) The determination...animal, if the scrapie control pilot project plan contains testing or other procedures that...

2013-01-01

224

33 CFR 203.85 - Rehabilitation of Federal flood control projects.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Rehabilitation of Federal flood control projects. 203.85 Section 203...Agreements § 203.85 Rehabilitation of Federal flood control projects. Some sponsors of Federal flood control projects are not required to...

2013-07-01

225

Cultivating Systemic Capacity: The Rhode Island Tobacco Control Enhancement Project  

Microsoft Academic Search

This paper describes the Rhode Island Tobacco Control Enhancement Project (TCEP), a state-university-community technical assistance system. TCEP was developed under the auspices of the Rhode Island Department of Health's Tobacco Control program and was designed to build capacity among nine community-based organizations to mount comprehensive tobacco control interventions in five diverse communities within the state. This paper: (1) provides a

Paul Florin; Carolyn Celebucki; John Stevenson; Jasmine Mena; Dawn Salago; Andrew White; Betty Harvey; Marianela Dougal

2006-01-01

226

Greenridge MultiPollutant Control Project Preliminary Public Design Report  

Microsoft Academic Search

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, NO, Hg, acid gases (SO, HCl, and HF), and particulate matter from smaller coal-fired electrical generating units (EGUs). The multi-pollutant control system includes

Daniel P. Connell

2009-01-01

227

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

PubMed Central

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

Fong, G T; Cummings, K M

2006-01-01

228

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

229

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

SciTech Connect

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

Law, V.J.

1994-07-07

230

Predicting sheetwash and rill erosion over the Australian continent  

Microsoft Academic Search

Abstract Soil erosion is a major environmental,issue in Australia. It reduces land productivity and has off-site effects ofdecreased,water quality. Broad-scale spatially distributed soil erosion estimation ,is essential ,for prioritising erosion control programs ,and as a ,component ,of broader ,assessments ,of natural ,resource condition. This paper describes spatial modelling ,methods ,and results that predict sheetwash ,and rill erosion over the Australian

Hua Lu; Ian P. Prosser; Chris J. Moran; John C. Gallant; Graeme Priestley; Janelle G. Stevenson

2003-01-01

231

Corticothalamic Projections Control Synchronization in Locally Coupled Bistable Thalamic Oscillators  

NASA Astrophysics Data System (ADS)

Thalamic circuits are able to generate state-dependent oscillations of different frequencies and degrees of synchronization. However, little is known about how synchronous oscillations, such as spindle oscillations in the thalamus, are organized in the intact brain. Experimental findings suggest that the simultaneous occurrence of spindle oscillations over widespread territories of the thalamus is due to the corticothalamic projections, as the synchrony is lost in the decorticated thalamus. In this Letter we study the influence of corticothalamic projections on the synchrony in a thalamic network, and uncover the underlying control mechanism, leading to a control method which is applicable for several types of oscillations in the central nervous system.

Mayer, Jörg; Schuster, Heinz Georg; Claussen, Jens Christian; Mölle, Matthias

2007-08-01

232

Control aspects of the Tacoma superconducting magnetic energy storage project  

SciTech Connect

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 the response characteristics of the unit, a-priori modeling of power system response, tradeoffs in control-law design, measured power system dynamics, and projection of unit effectiveness as a stabilizer.

Hauer, J.F.; Boenig, H.J.

1987-05-01

233

Evaluation of sediment transport formulae and detachment parameters in eroding rills using PSEM_2D and the Water Erosion Prediction Project (WEPP) database  

Microsoft Academic Search

The numerical model PSEM_2D is applied to reproduce the rill experiments described by Elliot et al. (1989) for five different textured soils. PSEM_2D is a two-dimensional water flow and erosion model incorporating the first-order detachment-transport coupling model. The infiltration parameters and the friction factor are calibrated to reproduce both the flow discharges and the flow velocities measured by Elliot et

Guillaume Nord; Michel Esteves

2007-01-01

234

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

235

Projection learning algorithm for threshold - controlled neural networks  

SciTech Connect

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

Reznik, A.M.

1995-03-01

236

Monitoring Construction Equipment for Automated Project Performance Control  

Microsoft Academic Search

The ability of company managers to respond to variations in performance in construction projects is severely limited by the time delay common in existing information and control systems in reporting schedule, budget and quality deviations from plan. We propose a system for interpreting data acquired automatically by monitoring the activity of major construction site equipment, such as tower cranes, concrete

Rafael Sacks; Ronie Navon; Aviad Shapira; Irina Brodetsky

237

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

238

A Parallel Projected Fletcher-Reeves Method for Optimal Control  

Microsoft Academic Search

We propose a new parametrized gradient projection algorithm for solving large scale constrained optimization problems, and we demonstrate thlie efficiency of the approach by comparing implementations on both the Cray 2 and Connection Machine 2. Numerical results are provided in solving discrete optimal control problems with very high dimensionality (up to 2,097,152 variables).

Gerard G. L. Meyer; Louis J. Podrazik

1992-01-01

239

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

240

Intelligent control of autonomous underwater vehicles: the Orca project  

Microsoft Academic Search

Establishing a useful presence in the ocean is becoming increasingly important to science, industry, and the military, yet the undersea environment is hostile to human presence. Autonomous underwater vehicles (AUVs) offer a solution. Before widespread use of AUVs is practical, however, mechanisms for intelligent control must be developed. In this paper, we report on the Orca project, which has the

Roy M. Turner

1995-01-01

241

Saylorville Lake Flood Control Project, Des Moines River, Iowa.  

National Technical Information Service (NTIS)

The statement proposes to continue construction of Saylorville Lake multi-purpose project for flood control, low-flow augmentation, fish and wildlife management, and recreation. The damsite is located on the Des Moines River in Polk County, Iowa, about 5 ...

1973-01-01

242

Monmouth Beach, New Jersey: Beach-Fill 'Hot Spot' Erosion Evaluation. Report 2. Functional Design of Shore-Protection Alternatives for Beach-Fill Longevity.  

National Technical Information Service (NTIS)

The U.S. Army Engineer District, New York, is constructing Section I- Sea Bright to Ocean Township, New Jersey, of the Atlantic Coast of New Jersey - Sandy Hook to Barnegat Inlet Beach Erosion Control Project. Within the initial portion of this project, a...

S. J. Smith G. L. Williams N. C. Kraus

1999-01-01

243

Control design deficiencies in HUD solar demonstration projects  

SciTech Connect

The Department of Housing and Urban Devlopment (HUD) residential solar heating and cooling demonstration program provided funding support for over 600 solar projects. These projects provide the largest single data base of solar heating and cooling experience now available. These data suggest that controls were problematic in many of the active and passive heating and domestic and domestic hot water systems in the program. This paper will assess the active system modes of operation and the control components as to their ability to perform as intended. A large number of systems in the demonstration program experienced control problems during testing, checkout, and operation (there were 238 reported control problems involving 192 systems). Frequently, trouble-shooting site visitors found control problems had disabled the whole system or caused a portion of the system to malfunction. The consequences are not as significant on the more carefully designed systems (i.e., the auxiliary still functions) but, on systems with inappropriately designed solar-auxiliary interfaces, the homeowners often were without adequate heat. The most common control problems involved excessive modes in system and, therefore, control design; errors in sensor set points, location, or installation; and poorly engineered or installed wiring to and from controller panels.

Freeborne, W.E.

1985-01-01

244

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

SciTech Connect

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

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

1990-08-01

245

Post-fire Wind Erosion in a Semiarid Shrub Steppe  

NASA Astrophysics Data System (ADS)

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

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

2007-12-01

246

Why does project planning fail; A look at the basics of planning in an era of sophisticated project control tools  

Microsoft Academic Search

The technology of project controls have become increasingly sophisticated. Some say that the technological advancements of the Nineteen-Eighties represented a maturation of project control tools. Others say that the advancements were merely bells and whistles that added little or nothing to the project management process. Above it all, as we enter the Nineties, there is a popular outcry to get

M. Foley; G. Luciano

1991-01-01

247

Erosive Destruction by Cavitation Flow Erosive Zerstoerungen durch Stroemungskavitation.  

National Technical Information Service (NTIS)

An intensive erosion cavitation chamber is developed and used to prove the corrosive and erosive effects of bubble explosion on metal surfaces. The mechanical loads during initial fluidic impact on soft aluminum are studied for erosive cavitation intensit...

H. Louis

1973-01-01

248

Intelligent control in mobile robotics: the PANORAMA project  

NASA Astrophysics Data System (ADS)

The European Community's strategic research initiative in information technology has been in place for seven years. A good example of the pan-European collaborative projects conducted under this initiative is PANORAMA: Perception and Navigation for Autonomous Mobile Robot Applications. This four-and-a-half-year project, completed in October 1993, aimed to prove the feasibility of an autonomous mobile robotic system replacing a human-operated vehicle working outdoors in a partially structured environment. The autonomous control of a mobile rock drilling machine was chosen as a challenging and representative test scenario. This paper presents an overview of intelligent mobile robot control architectures. Goals and objectives of the project are described, together with the makeup of the consortium and the roles of the members within it. The main technical achievements from PANORAMA are then presented, with emphasis given to the problems of realizing intelligent control. In particular, the planning and replanning of a mission, and the corresponding architectural choices and infrastructure required to support the chosen task oriented approach, are discussed. Specific attention is paid to the functional decomposition of the system, and how the requirements for `intelligent control' impact on the organization of the identified system components. Future work and outstanding problems are considered in some concluding remarks.

Greenway, Phil

1994-03-01

249

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

250

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

251

Erosion and erosion-corrosion of metals  

SciTech Connect

The loss of material from the surface of a metal being impacted by small, solid particles carried in a flowing gas occurs by a sequence of mechanical actions. The present work, which was presented as the plenary lecture at Corrosion/95, describes the mechanisms that occur on ductile and brittle materials and relates these mechanisms to surface loss rates. The ability of these mechanisms to be represented by mathematical models is assessed. The effects of material properties on erosion behavior is discussed. Combined erosion-corrosion surface degradation mechanisms are explained.

Levy, A.V. [Lawrence Berkeley Lab., CA (United States)

1995-11-01

252

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

253

Erosivity of LOVA Propellants.  

National Technical Information Service (NTIS)

The erosivity of a series of LOVA propellants was evaluated with the BRL 37-mm blowout gun and with heat input measured in a 105-mm M68 tank cannon. The results in the 37-mm blowout gun suggested that three of the eight propellants were as erosive as M30....

J. R. Ward T. L. Brosseau R. P. Kaste I. C. Stobie B. Bensinger

1981-01-01

254

Nitramine Propellant Erosivity - III.  

National Technical Information Service (NTIS)

This report is the third in a series on erosion measurements in a 37-mm blowout gun to compare the erosivity of propellants with RDX and HMX, denoted nitramines, with conventional double- and triple-base propellants. In these tests, a series of nitramine,...

R. Geene B. Grollman A. Niiler A. Rye J. R. Ward

1980-01-01

255

Erosion of a Geopolymer.  

National Technical Information Service (NTIS)

Solid-particle erosion studies were conducted on a representative geopolymer. The test conditions were normal impact of 390-micro meters angular Al2O3 erodent particles moving at 50, 70, or 100 m/s. Steady-state erosion rates were obtained and the materia...

K. C. Goretta N. Chen J. L. Roubort G. C. Lukey J. S. J. van Deventer

2002-01-01

256

Erosion of Concrete.  

National Technical Information Service (NTIS)

Within the context of this research, erosion is taken to mean the wearing away of a surface by water and the sediments carried along in it. In structures in the sea, erosion may be a phenomenon of attack if water carrying sand and silt regularly flows to ...

M. G. M. Pat H. W. Reinhardt

1979-01-01

257

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

Microsoft Academic Search

System dynamics has 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 policy advice to managers to control project performance. To address this gap we examine the impact of three common project controls available to project managers to

David N. Ford; James M. Lyneis; Timothy R. B. Taylor

258

RefMod PM : Reference Information Model for Enterprise-Wide Project Planning, Controlling and Coordination in Matrix Project Organizations  

Microsoft Academic Search

Project information systems can be regarded as a sub-system of project management systems. Their aim is to supply all relevant\\u000a stakeholders with the information necessary to plan, control and coordinate projects. The objective of the research presented\\u000a in this paper is the development of a semi-formal, conceptual reference information model for the enterprise-wide planning,\\u000a controlling and coordination of projects in

Frederik Ahlemann

259

Erosion of a geopolymer.  

SciTech Connect

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

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

2002-07-02

260

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

261

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

262

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

263

Using Thermochronology to Understand Orogenic Erosion  

NASA Astrophysics Data System (ADS)

Erosion of orogenic mountain ranges exhumes deeply buried rocks and controls weathering, climate, and sediment production and transport at a variety of scales. Erosion also affects the topographic form and kinematics of orogens, and it may provide dynamic feedbacks between climate and tectonics by spatially focused erosion and rock uplift. Thermochronology measures the timing and rates at which rocks approach the surface and cool as a result of exhumation. Relatively well-understood noble gas and fission-track thermochronometric systems have closure temperatures ranging from 60 to 550°C, making them sensitive to exhumation through crustal depths of about one to tens of kilometers. Thus, thermochronology can constrain erosion rates and their spatial-temporal variations on timescales of 105 107 years, commensurate with orogenic growth and decay cycles and possible climate-tectonic feedback response times. Useful methods for estimating erosion rates include inverting ages for erosion rates using crustal thermal models, vertical transects, and detrital approaches. Spatial-temporal patterns of thermochronometrically determined erosion rates help constrain flow of material through orogenic wedges, orogenic growth and decay cycles, paleorelief, and relationships with structural, geomorphic, or climatic features.

Reiners, Peter W.; Brandon, Mark T.

2006-05-01

264

Fluvial Erosion Measurements of Streambank Using Photo-Electronic Erosion Pins (peep)  

NASA Astrophysics Data System (ADS)

Cohesive streambank erosion is characterized by two main mechanisms, fluvial entrainment of individual particles and bank failure due to gravity (Thorne, 1980). In this study, the relative importance of fluvial erosion (compared to mass failure) was determined in two reaches from different locations of the Clear Creek Watershed (CCW). The main goal of the project was the identification of the key erosion process at each site. Beyond the distinguished flow conditions (hydraulic forces), different stream orders, and land-use, no further attempts were made to identify other key driving agents behind the erosion, such subaerial processes (e.g., seepage, freeze/thaw) acting at the cohesive riverbanks (Lindow et al., 2009). Erosion lengths up to 38 cm were detected. The bank erosion monitoring at high resolution intervals due to the PEEPS allowed for better characterization the fluvial erosion occurring at this site and develop a correspondence between sedigraphs and hydrographs. .Similar statistical methods were used at both sites to support our findings. The moving average identified the dominant trend of the data and the variability of the erosion lengths at the two sites. Further, the use of the Shewhart Charts allowed us to detect the critical erosion events during the period of observation. Finally the overall performance of the PEEPs was evaluated during this study. A correlation analysis was conducted between the direct measurements of traditional methods (e.g., erosion pins, geodetical surveys, measure tape) and the automated data recorded by the PEEP. The maximum error between manual and automated measurements of the exposed length of the PEEPs was less than 27%. The error between the channel survey and the automated PEEP measurements was less than 14%.

Sutarto, T.; Papanicolaou, T.; Wilson, C. G.; Bertrand, F.

2010-12-01

265

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

266

Stop the software architecture erosion: building better software systems  

Microsoft Academic Search

In lots of software projects unfortunately an architectural erosion happens over time. Modules which were independent, become connected, plug-ins finally depend on each other, and in general the architecture gets violated more and more. In this paper we will discuss how to avoid such architecture- and design-erosion and how an already eroded system can be fixed again. We will look

Bernhard Merkle

2010-01-01

267

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

268

The article has been accredited by Health Authority - Abu Dhabi as having educational content and is acceptable for up to 2 (Category 1) credit hours. Credit may be claimed for one year from the date of subscription (20 CME hours per year). Approaches for Prevention & Control of Dental Erosion  

Microsoft Academic Search

In light of increasing reports of the incidence and prevalence of dental erosion, it is now nec- essary that dental practitioners are familiar with the etiological and predisposing factors of dental erosion, as well as the possible ways of its prevention and control. It may be easier to gain pa- tients' compliance with the advice of administering a remineralizing agent

Bennett T. Amaechi

269

Atmospheric CO 2 consumption by continental erosion: present-day controls and implications for the last glacial maximum  

Microsoft Academic Search

The export of carbon from land to sea by rivers represents a major link in the global carbon cycle. For all principal carbon forms, the main factors that control the present-day fluxes at the global scale have been determined in order to establish global budgets and to predict regional fluxes. Dissolved organic carbon fluxes are mainly related to drainage intensity,

Wolfgang Ludwig; Philippe Amiotte-Suchet; Guy Munhoven; Jean-Luc Probst

1998-01-01

270

Issues of upscaling in space and time with soil erosion models  

NASA Astrophysics Data System (ADS)

Soil erosion - the entrainment, transport and deposition of soil particles - is an important phenomenon to understand; the quantity of soil loss determines the long term on-site sustainability of agricultural production (Pimental et al., 1995), and has potentially important off-site impacts on water quality (Bilotta and Brazier, 2008). The fundamental mechanisms of the soil erosion process have been studied at the laboratory scale, plot scale (Wainwright et al., 2000), the small catchment scale (refs here) and river basin scale through sediment yield and budgeting work. Subsequently, soil erosion models have developed alongside and directly from this empirical work, from data-based models such as the USLE (Wischmeier and Smith, 1978), to ‘physics or process-based' models such as EUROSEM (Morgan et al., 1998) and WEPP (Nearing et al., 1989). Model development has helped to structure our understanding of the fundamental factors that control soil erosion process at the plot and field scale. Despite these advances, however, our understanding of and ability to predict erosion and sediment yield at the same plot, field and also larger catchment scales remains poor. Sediment yield has been shown to both increase and decrease as a function of drainage area (de Vente et al., 2006); the lack of a simple relationship demonstrates complex and scale-dependant process domination throughout a catchment, and emphasises our uncertainty and poor conceptual basis for predicting plot to catchment scale erosion rates and sediment yields (Parsons et al., 2006b). Therefore, this paper presents a review of the problems associated with modelling soil erosion across spatial and temporal scales and suggests some potential solutions to address these problems. The transport-distance approach to scaling erosion rates (Wainwright, et al., 2008) is assessed and discussed in light of alternative techniques to predict erosion across spatial and temporal scales. References Bilotta, G.S. and Brazier, R.E., 2008. Understanding the influence of suspended solids on water quality and aquatic biota. Water Research, 42(12): 2849-2861. de Vente, J., Poesen, J., Bazzoffi, P., Van Ropaey, A.V. and Verstraeten, G., 2006. Predicting catchment sediment yield in Mediterranean environments: the importance of sediment sources and connectivity in Italian drainage basins. Earth Surface Processes And Landforms, 31: 1017-1034. Morgan, R.P.C. et al., 1998. The European soil erosion model (EUROSEM): a dynamic approach for predicting sediment transport from fields to small catchments. Earth Surface Processes And Landforms, 23: 527-544. Nearing, M. A., G. R. Foster, L. J. Lane, and S. C. Finkner. 1989. A process-based soil erosion model for USDA Water Erosion Prediction Project technology. Trans. ASAE 32(5): 1587-1593. Parsons, A.J., Brazier, R.E., Wainwright, J. and Powell, D.M., 2006a. Scale relationships in hillslope runoff and erosion. Earth Surface Processes and Landforms, 31(11): 1384-1393. Parsons, A.J., Wainwright, J., Brazier, R.E. and Powell, D.M., 2006b. Is sediment delivery a fallacy? Earth Surface Processes and Landforms, 31(10): 1325-1328. Pimental, D. et al., 1995. Environmental and economic costs of soil erosion and conservation benefits. Science, 267:1117-1122. Wainwright, J., Parsons, A.J. and Abrahams, A.D., 2000. Plot-scale studies of vegetation, overland flow and erosion interactions: case studies from Arizona and New Mexico. Hydrological Processes, 14(16-17): 2921-2943. Wischmeier, W.H. and Smith, D.D., 1978. Predicting rainfall erosion losses - a guide for conservation planning., 537.

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

2009-04-01

271

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

272

Spark gap electrode erosion  

NASA Astrophysics Data System (ADS)

The results of a one-year contract on electrode erosion phenomena are summarized. The arc voltage drop in a spark gap was measured for various electrode, gas, and pressure combinations. A previously developed model of self breakdown voltage distribution was extended. A jet model for electrode erosion was proposed and an experimental arrangement for testing the model was constructed. The effects of inhomogeneities and impurities in the electrodes were investigated. Some of the work described here is scheduled for completion in 1985 under a current grant (AFOSR 84-0032). The areas of investigation described here include: (1) Self breakdown voltage distributions; (2) Electrode erosion; (3) Spark gap voltage recovery.

Krompholz, H.; Kristiansen, M.

1984-12-01

273

Variation of vegetation incidence by installation of a slit-type erosion control dam -a study based on mesh data and variation of substrata of habitats-  

NASA Astrophysics Data System (ADS)

This paper summarizes a field survey on physical features of and vegetation on a dry riverbed around a slit-type erosion control dam in Ozo river. Field surveys cover the range 130m to upstream and 200m to downstream of the dam and were performed in 2001 before the construction, and 2008 and 2009 after the construction. We developed a relationship between physical property of substrata and incidence of species of vegetation on the same property of substrata for each species. This incidence ratio is obtained from the observed data in 2001.Predicted mesh numbers and observed mesh numbers for all species observed in three years were shown in one figure. An estimation line between prediction and observation which is developed by Generalized Linear Mixed Model can give reliable relationship even for cases of sparse incidence of vegetation. It is shown that variation of vegetation incidence can be predicted by physical property of substrata. However, it is also shown that substrata and vegetation in studied area are still under succession stage in short period after the impact of construction.

Sannoh, Keinosuke; Sawa, Yasuo; Taya, Yuki; Tamai, Nobuyuki

274

Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion (FBC) system. Technical progress report No. 8, July 1994--September 1994  

SciTech Connect

This technical report summarizes the research work performed and progress achieved during the period of July 1, 1994 to September 30, 1994. The metal wastage of AISI 1018 low carbon steel at different particle velocity was discussed to understand the erosion phenomena of in-bed tube in FBC system. At both low velocity (2.5 m/s) and high (30 m/s), the maximum metal wastage was occurred at 45{degrees} of impact angle. The erosion rates at low particle velocity were two (2) to three (3) orders of magnitude lower than those at high particle velocity. The characteristics of anti-erosion and design considerations were discussed and suggested for some basic design guidelines, which might be important to the designer of bubbling fluidized combustors. The working principle and mechanism of anti-erosion devices will be discussed. Based upon the understanding of the working principle and mechanism of anti-erosion devices, different types of ant-erosion tube will be designed for the cold model bench-scale FBC system.

Lee, S.W.

1994-10-01

275

Project B610 process control configuration acceptance test procedure  

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

Silvan, G.R.

1994-09-20

276

Erosion dynamics of a wet granular medium  

NASA Astrophysics Data System (ADS)

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

Lefebvre, Gautier; Jop, Pierre

2013-09-01

277

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

278

Plasma Erosion Opening Switch.  

National Technical Information Service (NTIS)

The Plasma Erosion Opening Switch (PEOS) can conduct high current (approx. MA), open quickly (<10ns), and withstand high voltage (approx. MV). This switching technique has been used in inductive energy storage experiments and can be used with existing gen...

R. J. Commisso G. Cooperstein R. A. Meger J. M. Neri P. F. Ottinger

1985-01-01

279

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.

280

Rainfall erosivity in Central Chile  

NASA Astrophysics Data System (ADS)

We built the first rainfall erosivity map for most of the cultivated land in Chile. Erosivities varied as a result of the rainfall depths, elevation and latitude. We established a relation between the calculated erosivities and annual rainfall. This relation offers a means of estimating erosivity when time or data is limiting.

Bonilla, Carlos A.; Vidal, Karim L.

2011-11-01

281

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

282

Erosion Prevention in Boilers  

Microsoft Academic Search

\\u000a Erosion is a process of wear in which materials are removed from a solid surface by the action of solid particles impinging\\u000a on it. This type of wear is common in many industrial devices, including boilers. The combustion products of coal contain\\u000a fly ash particles, which impinge on boiler tubes or fan blades and erode them. Fly ash erosion is

Prabir Basu; Cen Kefa; Louis Jestin

283

Advanced Petroleum-Based Fuels--Diesel Emissions Control Project (APBF-DEC): Lubricants Project, Phase 1 Summary, July 2004  

SciTech Connect

The Advanced Petroleum Based Fuels-Diesel Emission Control project is a government/industry collaborative project to identify the optimal combinations of low-sulfur diesel fuels, lubricants, diesel engines, and emission control systems to meet projected emission standards for the 2004-2010 time period. This summary describes the results of the first phase of the lubricants study investigating the impact on lubricant formulation on engine-out emissions.

Not Available

2004-07-01

284

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

PubMed

New toothpastes with anti-erosion claims are marketed, but little is known about their effectiveness. This study investigates these products in comparison with various conventional NaF toothpastes and tin-containing products with respect to their erosion protection/abrasion prevention properties. In experiment 1, samples were demineralised (10 days, 6 × 2 min/day; citric acid, pH 2.4), exposed to toothpaste slurries (2 × 2 min/day) and intermittently stored in a mineral salt solution. In experiment 2, samples were additionally brushed for 15 s during the slurry immersion time. Study products were 8 conventional NaF toothpastes (1,400-1,490 ppm F), 4 formulations with anti-erosion claims (2 F toothpastes: NaF + KNO(3) and NaF + hydroxyapatite; and 2 F-free toothpastes: zinc-carbonate-hydroxyapatite, and chitosan) and 2 Sn-containing products (toothpaste: 3,436 ppm Sn, 1,450 ppm F as SnF(2)/NaF; gel: 970 ppm F, 3,030 ppm Sn as SnF(2)). A mouth rinse (500 ppm F as AmF/NaF, 800 ppm Sn as SnCl(2)) was the positive control. Tissue loss was quantified profilometrically. In experiment 1, most NaF toothpastes and 1 F-free formulation reduced tissue loss significantly (between 19 and 42%); the Sn-containing formulations were the most effective (toothpaste and gel 55 and 78% reduction, respectively). In experiment 2, only 4 NaF toothpastes revealed significant effects compared to the F-free control (reduction between 29 and 37%); the F-free special preparations and the Sn toothpaste had no significant effect. The Sn gel (reduction 75%) revealed the best result. Conventional NaF toothpastes reduced the erosive tissue loss, but had limited efficacy regarding the prevention of brushing abrasion. The special formulations were not superior, or were even less effective. PMID:22156703

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

2011-12-08

285

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

286

STREAM BANK EROSION UNDER DIFFERENT RIPARIAN LAND-USE PRACTICES IN NORTHEAST IOWA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Row-cropping and grazing in riparian areas have altered the natural hydrologic cycle and accelerated stream incision and bank erosion. In incised streams, bank erosion can typically contribute 50 to 90% of the stream's sediment and phosphorus load. In this northeast Iowa project, stream bank erosion...

287

CRCHD SPN Project: The Network for Cancer Control Research Among American Indian and Alaska Native Populations  

Cancer.gov

CRCHD SPN Project: The Network for Cancer Control Research Among American Indian and Alaska Native Populations  Back to CRCHD Completed Research SPN Project Listing The Network for Cancer Control Research Among American Indian and Alaska Native

288

Erosion in Dual-Phase Microstructures: Final Report.  

National Technical Information Service (NTIS)

This project was designed to provide a systematic investigation of the effects of microstructural variables on particle impact erosion of two-phase metallic alloys containing large second-phase particles (SPPs). Commercial alloys that contain large hard c...

T. H. Kosel

1987-01-01

289

Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion (FBC) system. Technical progress report No. 14, [January 1, 1996--March 31, 1996  

SciTech Connect

The material wastage tests were continued to analyze erosion phenomena under the simulated erosion conditions of in-bed tubes in fluidized bed combustors. AISI 1018 steel and three thermal sprayed coating specimens were tested at an elevated temperature (300{degrees}C) using nozzle type erosion tester. Bed ashes retrieved from the operating biomass-fired boiler were used for erodent particles at a particle loading of 375 g, at particle impact angle of 30{degrees}, at particle velocity 60 m/s for exposure periods of 4 hours. The specimens were water-cooled on the backside. The material wastage of specimens was determined by thickness measurements. Test results can be seen that the cooled specimen had greater material wastage than that of the uncooled specimens. In addition, all of thermal-sprayed coating specimens for both cooled and uncooled specimens could reduce the erosion wastage rates as compared with 1018 steel. Among the three thermal-sprayed coatings, a DS-105 specimen of high velocity oxygen fuel spraying exhibited the lowest erosion wastage rate. When tested a higher particle velocity (60 m/s), but at the same elevated temperature (300{degrees}C), the material wastage rate of all three coatings was about 6 to 18 times higher than that of the material wastage at a low particle velocity (2.5 m/s).

Lee, Seong W.

1996-04-01

290

Gastroesophageal Reflux is Not Associated with Dental Erosion in Children  

PubMed Central

Background & Aims Dental erosion is a complication of gastroesophageal reflux (GER) in adults; in children, it is not clear if GER has a role in dental pathologic conditions. Dietary intake, oral hygiene, high bacterial load, and decreased salivary flow might contribute independently to GER development or dental erosion, but their potential involvement in dental erosion from GER is not understood. We investigated the prevalence of dental erosion among children with and without GER symptoms, and whether salivary flow rate or bacterial load contribute to location-specific dental erosion. Methods We performed a cross-sectional study of 59 children (ages 9–17 y) with symptoms of GER and 20 asymptomatic children (controls); all completed a questionnaire on dietary exposure. Permanent teeth were examined for erosion into dentin, erosion locations, and affected surfaces. The dentist was not aware of GER status, nor was the gastroenterologist aware of dental status. Stimulated salivary flow was measured and salivary bacterial load was calculated for total bacteria, Streptococcus mutans and Lactobacilli. Results Controlling for age, dietary intake, and oral hygiene, there was no association between GER symptoms and dental erosion, by tooth location or affected surface. Salivary flow did not correlate with GER symptoms or erosion. Erosion location and surface were independent of total bacteria and levels of Streptococcus mutans and Lactobacilli. Conclusions Location-specific dental erosion is not associated with GER, salivary flow, or bacterial load. Prospective studies are required to determine the pathogenesis of GER-associated dental erosion and the relationship between dental caries to GER and dental erosion.

Wild, Yvette K.; Heyman, Melvin B.; Vittinghoff, Eric; Dalal, Deepal H.; Wojcicki, Janet M.; Clark, Ann L.; Rechmann, Beate; Rechmann, Peter

2011-01-01

291

Lithologic Control on the Form of Amphitheater-headed Channels and the Influence of Seepage Erosion vs. Downstream Incision on Rates of Waterfall Retreat  

NASA Astrophysics Data System (ADS)

The use of amphitheater-headed channels as indicators for groundwater sapping on Earth and Mars was recently challenged by Lamb et al., (2006, 2007) who demonstrated that this form-process relation is not unique. A field study of 27 channels with amphitheater-headed valleys along the Dead Sea western tectonic escarpment identified seepage indications only at 7 channels and seepage-related sapping at 2 of these 7 channels. These findings support the idea that amphitheater-headed valleys can form across waterfalls regardless of seepage erosion. Major controls on the amphitheater morphology of the studied channels include waterfall height and especially the height of the waterfall erodible subcaprock face ( Hscap), which dictates the length of talus slopes along the canyon walls adjacent to the waterfall. The characteristic width of the amphitheater can be approximated by: 2 Hscap/tan? + dpp where ? is the talus angle of repose and ( dpp) is the plunge pool diameter. Amphitheatre morphology is less pronounced and valley plan form is V- shaped across waterfalls with low Hscap. Utilizing the downstream rate of change in valley width ( dw/dx) we define a V-plan form as a condition where dw/dx is uniform and a U-plan form where dw/dx decreases downstream. We demonstrate that dw/dx is a positive function of channel gradient ( dz/dx) and argue that rapid downstream decrease in channel gradient can contribute to a U-plan form. Commonly found debris-induced oversteepened reaches below waterfalls are therefore another possible trigger to amphitheater morphology. Waterfalls within two of the escarpment stretches we have studied have quasi uniform subcaprock face height (i.e., similar toe stratigraphic position) independent of drainage area and retreat distance from the escarpment outlet. This indicates that their retreat rate and the rate of downstream incision are tightly interdependent. Retreat rates of these waterfalls are probably set by base level lowering and incision wave velocity at a downstream transition to a resistant formation. This velocity influences the efficiency of coarse debris evacuation (transportation and weathering) through its effect on the length and the gradients of the reach between the resistant formation and the waterfall. Under such conditions a theoretical onset of seepage along the contact marked by the upper end of the subcaprock talus slope at the waterfall face will not affect retreat rates assuming coverage of this contact by talus debris can suppress seepage-induced erosion. We demonstrate, however, that there are plausible theoretical cases where Hscap can vary over time and seepage can influence waterfall retreat rates for Myrs. We also show that groundwater sapping observed in two of the waterfalls we have studied probably still effects their retreat rate.

Haviv, I.; Enzel, Y.; Whipple, K. X.; Zilberman, E.; Matmon, A.; Stone, J.; Fifield, K.

2007-12-01

292

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

293

The threat of soil erosion to long-term crop production  

Microsoft Academic Search

National increases in row crops at the expense of hay and pasture crops, particularly on steeper slopes, have made the control of erosion a difficult prospect. Management practices that fit the various field conditions are needed to accomplish effective erosion control. These measures should be selected on the basis of soil characteristics, landscape type, and the amount of ongoing erosion.

W. E. Larson; F. J. Pierce; R. H. Dowdy

1983-01-01

294

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

295

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

296

Asthma and dental erosion.  

PubMed

Asthma is a chronic inflammatory condition of the airway, characterised by the presence of airflow obstruction which is variable over short periods of time, or is reversible with treatment. Medication comprises of bronchodilators, corticosteroids and anticholinergic drugs. Most asthma drugs are inhaled using various forms of inhalers or nebulizers. Inhaled drugs must be used regularly. The effects of these drugs on the dentition such as tooth decay and erosion have been a subject of debate among dental practitioners. Asthmatic medications can place the patient at risk of dental erosion by reducing salivary protection against extrinsic or intrinsic acids. Asthmatic individuals are one of the higher risk groups suffering from dental erosion. Therefore patients with bronchial asthma should receive special prophylactic attention. This article presents a case of an asthmatic with dental manifestations and reviews the possible causes and management of the same. PMID:20071821

Manuel, S T; Kundabala, M; Shetty, N; Parolia, A

297

Assessing Erosion on U.S. Cropland: Land Management and Physical Features.  

National Technical Information Service (NTIS)

The taxonomy of soil erosion presented here delineates land resources with high potential for erosion control. More than one-third of U.S. cropland is inherently nonerosive under all management regimes, about half requires conservation management to keep ...

N. L. Bills R. E. Heimlich

1984-01-01

298

Fluoride in dental erosion.  

PubMed

Dental erosion develops through chronic exposure to extrinsic/intrinsic acids with a low pH. Enamel erosion is characterized by a centripetal dissolution leaving a small demineralized zone behind. In contrast, erosive demineralization in dentin is more complex as the acid-induced mineral dissolution leads to the exposure of collagenous organic matrix, which hampers ion diffusion and, thus, reduces further progression of the lesion. Topical fluoridation inducing the formation of a protective layer on dental hard tissue, which is composed of CaF(2) (in case of conventional fluorides like amine fluoride or sodium fluoride) or of metal-rich surface precipitates (in case of titanium tetrafluoride or tin-containing fluoride products), appears to be most effective on enamel. In dentin, the preventive effect of fluorides is highly dependent on the presence of the organic matrix. In situ studies have shown a higher protective potential of fluoride in enamel compared to dentin, probably as the organic matrix is affected by enzymatical and chemical degradation as well as by abrasive influences in the clinical situation. There is convincing evidence that fluoride, in general, can strengthen teeth against erosive acid damage, and high-concentration fluoride agents and/or frequent applications are considered potentially effective approaches in preventing dental erosion. The use of tin-containing fluoride products might provide the best approach for effective prevention of dental erosion. Further properly designed in situ or clinical studies are recommended in order to better understand the relative differences in performance of the various fluoride agents and formulations. PMID:21701198

Magalhães, Ana Carolina; Wiegand, Annette; Rios, Daniela; Buzalaf, Marília Afonso Rabelo; Lussi, Adrian

2011-06-23

299

Evaluation of Propellant Erosivity with Vented Erosion Apparatus.  

National Technical Information Service (NTIS)

Gun steel erosion studies were performed using three propellant types (double-base, triple-base, and RDX composite), each formulated to have isochoric flame temperatures of approximately 2700 K, 3000 K, and 3300 K, respectively. These erosion studies were...

A. J. Bracuti L. Bottei J. A. Lannon L. H. Caveny

1981-01-01

300

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

Dupre, Bill

301

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

Code of Federal Regulations, 2012 CFR

...project-level mitigation and control measures. 93.125 Section 93.125 Protection...project-level mitigation and control measures. (a) Prior to determining that...project-level mitigation or control measures which are identified as conditions...

2012-07-01

302

Spinal projection neurons control turning behaviors in zebrafish.  

PubMed

Discrete populations of brainstem spinal projection neurons (SPNs) have been shown to exhibit behavior-specific responses during locomotion [1-9], suggesting that separate descending pathways, each dedicated to a specific behavior, control locomotion. In an alternative model, a large variety of motor outputs could be generated from different combinations of a small number of basic motor pathways. We examined this possibility by studying the precise role of ventromedially located hindbrain SPNs (vSPNs) in generating turning behaviors. We found that unilateral laser ablation of vSPNs reduces the tail deflection and cycle period specifically during the first undulation cycle of a swim bout, whereas later tail movements are unaffected. This holds true during phototaxic [10], optomotor [11], dark-flash-induced [12], and spontaneous turns [13], suggesting a universal role of these neurons in controlling turning behaviors. Importantly, we found that the ablation not only abolishes turns but also results in a dramatic increase in the number of forward swims, suggesting that these neurons transform forward swims into turns by introducing turning kinematics into a basic motor pattern of symmetric tail undulations. Finally, we show that vSPN activity is direction specific and graded by turning angle. Together, these results provide a clear example of how a specific motor pattern can be transformed into different behavioral events by the graded activation of a small set of SPNs. PMID:23910662

Huang, Kuo-Hua; Ahrens, Misha B; Dunn, Timothy W; Engert, Florian

2013-08-01

303

Spinal Projection Neurons Control Turning Behaviors in Zebrafish  

PubMed Central

Summary Discrete populations of brainstem spinal projection neurons (SPNs) have been shown to exhibit behavior-specific responses during locomotion [1–9], suggesting that separate descending pathways, each dedicated to a specific behavior, control locomotion. In an alternative model, a large variety of motor outputs could be generated from different combinations of a small number of basic motor pathways. We examined this possibility by studying the precise role of ventromedially located hindbrain SPNs (vSPNs) in generating turning behaviors. We found that unilateral laser ablation of vSPNs reduces the tail deflection and cycle period specifically during the first undulation cycle of a swim bout, whereas later tail movements are unaffected. This holds true during phototaxic [10], optomotor [11], dark-flash-induced [12], and spontaneous turns [13], suggesting a universal role of these neurons in controlling turning behaviors. Importantly, we found that the ablation not only abolishes turns but also results in a dramatic increase in the number of forward swims, suggesting that these neurons transform forward swims into turns by introducing turning kinematics into a basic motor pattern of symmetric tail undulations. Finally, we show that vSPN activity is direction specific and graded by turning angle. Together, these results provide a clear example of how a specific motor pattern can be transformed into different behavioral events by the graded activation of a small set of SPNs.

Huang, Kuo-Hua; Ahrens, Misha B.; Dunn, Timothy W.; Engert, Florian

2013-01-01

304

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

305

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%, 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. This talk considers 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

2010-10-01

306

Studies of some phenomena in control engineering projects - With application to precipitation processes.  

National Technical Information Service (NTIS)

This thesis deals with the life-cycle of a control engineering project and some phenomena encountered in such projects. Different types of control strategies are discussed and an attempt is made to classify them into categories. Some case projects are pre...

K. Stoele-Hansen

1998-01-01

307

Assessing and controlling the quality of a project end product: the earned quality method  

Microsoft Academic Search

Quality is achieved to the extent that a project end product meets the client's needs and expectations. This paper addresses the fundamental issues relating to the periodic assessment and control of the quality of the end product of a project. The proposed earned quality method (EQM) enables project managers to assess and control the quality of the end product throughout

Jean Paul Paquin; Jean Couillard; Dominique J. Ferrand

2000-01-01

308

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

309

THE UNITED STATES EXPERIENCE IN CONTROLLING EROSION: INVOLVEMENT OF GOVERNMENT, RURAL VS. URBAN CONTROLS, AND THE BLURRING OF THOSE DIFFERENCES Prepared for presentation at the 2002 ISCO Conference, May 26-31, 2002, Beijing, PRC  

Microsoft Academic Search

The United States history and experience in concern for erosion and its concequences is an interesting technical and public policy study. Starting with the nation's settlement and founding in the 1700's, there are papers and texts that demonstrate our earliest settlers and scientists were aware of the problems caused by erosion as man disturbed the soil, and were interested in

John W. Peterson

310

Recurrent Corneal Erosion  

MedlinePLUS

... Feeling that something is in the eye Pain Self-Care Guidelines The self-care for recurrent corneal erosion is very similar to ... the light sensitivity. What is very important in self-care is learning how to open your eyes when ...

311

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 ...

312

Mechanisms of Erosion.  

National Technical Information Service (NTIS)

A single stage gas gun and a whirling arm rig have been used to study the erosion of mono- and poly-crystalline MgO and Al and mono-crystalline LiF targets by millimeter scale steel and WC - 6% Co spheres. Both single and multiple impact studies were vari...

N. H. Macmillan

1980-01-01

313

Animating Corrosion and Erosion  

Microsoft Academic Search

In this paper, we present a simple method for animating natural phenomena such as erosion, sedimentation, and acidic corrosion. We discretize the appropriate physical or chemical equations using finite differences, and we use the results to modify the shape of a solid body. We remove mass from an object by treating its surface as a level set and advecting it

Christopher Wojtan; Mark Carlson; Peter J. Mucha; Greg Turk

2007-01-01

314

Erosion--Corrosion.  

National Technical Information Service (NTIS)

The deterioration of materials by corrosion or erosion by itself presents a formidable problem and for this reason investigators have studied these two phenomena independently. In fact, there are very few systematic studies on E-C and the majority of refe...

B. Vyas

1978-01-01

315

Dental 'erosion' revisited.  

PubMed

The term "erosion," as currently used in dentistry, is not only a misnomer but also is misleading, according to the authors. The authors highlight the critical roles of occlusal function and parafunction in the multifactorial etiology of cervical lesions and relate their significance to clinical practice. They propose a revised nomenclature for and classification of dental hard tissue lesions. PMID:7759687

Grippo, J O; Simring, M

1995-05-01

316

Reduction of erosion in elbows due to flow modifications: Final report, Phase 1. [Elbows  

SciTech Connect

The objective of this project is to investigate the concept of flow-field modification as a method for reducing erosion in bends (elbows) used in pneumatic transport systems. Flow field modifications were primarily accomplished by injecting air at selected locations within the bends. Part I of this project shows the feasibility of the concept. Part II of this project will include further experiments and analysis, leading to a design methodology for incorporating this concept into piping systems. This report represents the final report for Part I of this project. This report contains a survey of the literature dealing with the erosion in bends (elbows) and the fundamental subjects of erosion and two-phase, gas-solids, flow. Based on this literature survey, a pneumatic transport test loop was constructed. Several bend designs were tested, using sand, under a variety of operating conditions. The results of this exploratory effort indicate that modifying the flow field in a bend with jets may: (1) decrease erosion; (2) change the erosion pattern with the same amount of erosion; or (3) significantly increase the erosion process. Data indicate that the erosion rate may be reduced by low-velocity jets for high phase-density flow. Apparently the interaction of jets with dilute phase-density flow tends to accelerate the erosion process. It is recommended that the project be continued in order to more fully understand the process and its capabilities to solve the difficult technical problem of erosion in bends (elbows).

Johnson, E.K.; Means, K.H.; Eyler, R.L.; Holtzworth, J.D.

1987-11-01

317

Scale linkage and contingency effects of field-scale and hillslope-scale controls of long-term soil erosion: Anthropogeomorphic sediment flux in agricultural loess watersheds of Southern Germany  

NASA Astrophysics Data System (ADS)

Agricultural landscapes with a millennial-scale history of cultivation are common in many loess areas of central Europe. Over time, patterns of erosion and sedimentation have been continually modified via the variable imposition of anthropogenic discontinuities and linkages on fragmented hillslope sediment cascades, which eventually caused the complicated soilscape pattern. These field records challenge topographically oriented models of hillslope erosion and simple predictions of longer-term change of spatial soilscape by cultivation activities. A thorough understanding how soilscape patterns form in the long-term, however, is essential to develop spatial concepts of the sediment budget, particularly for the spatial modeling of anthropogenic hillslope sediment flux using GIS. In this study I used extensive datasets of anthropogenic soil truncation and burial in a typical undulating loess watershed in southern Germany (10 km 2, Wetterau Basin, N of Frankfurt a.M.). Spatial soilscape properties and historic sediment flux, as caused by cultivation over seven millennia, were evaluated by these data. The soilscape pattern on the low-gradient hillslopes of the study area was found to be marked by a statistical near-random pattern of varying depth (thickness) of truncation and overthickened burial. Moreover, it was shown that truncation and burial had developed independently from each other and did not correlate with either hillslope gradient or downslope curvature. Hence, in the field any combination of (few) nearly preserved, severely truncated or completely removed soil profiles with either no, some or a thick sediment cover is present, thereby lacking an obvious spatial pattern. Here, I suggest putting long-term change of the soilscape into a contextual anthropogeomorphic systems perspective, that accommodates components of human-induced soil erosion operating at different spatial scales to interpret the longer-term spatial consequences at the hillslope-system level. In the study area, system scale linkages are marked by the spatial intersection of a finer-scaled managed field system with a broader hillslope-scale framework of 'natural' erosion controls. In the low-gradient study area, field borders exert control over the spatial reference of soil erosion and sedimentation sites. Over time, this brought about a growing historical and spatial contingency change to the soilscape, because of arbitrary spatial changes of the field system which are inherent in its socio-agricultural maintenance. Thus, the very low-gradient and low-erosivity setting of the study area have singled out the agency of human-induced spatial and connectivity controls and contingency for long-term spatial hillslope sediment flux. Although these findings may be less true for different settings, they allow for deriving a generic conceptual model of the linkages between 'natural' and anthropogenic subsystems to interpret the effects of long-term human-induced sediment flux. Accordingly, the resulting balance between on-hillslope net storage and net delivery to streams is scaling with basic physiographic properties of erosivity and sedimentation as well as the degree of anthropogenic hillslope fragmentation. For loess areas in Europe variable fields are fundamental anthropogeomorphic units that determine appropriate system scaling for historic sediment flux analysis and constrain retrodiction and prediction of changing fluxes at a point and a time at watershed scales. Methodical implications address adequate sampling strategies to record soilscape change, as a result of which a critical review of the applicability of the catena concept to long-cultivated hillslopes in central Europe was included. Finally, the suggested refined generic model of long-term, human-controlled sediment flux involves a number of research opportunities, particularly for linking modeling approaches to long-term field records of cultivation-related change in the soilscape.

Houben, Peter

2008-10-01

318

Effects of topsoiling on rates of erosion and erosion processes in coal mine spoil banks in Utrillas, Teruel, Spain  

Microsoft Academic Search

Runoff production and soil erosion, produced by energetic Mediterranean storms, are amongst the first environmental impacts of opencast mining activity and amongst the main limiting factors in achieving self-sustaining reclaimed landscapes in Teruel. This paper aims to understand the geomorphological response of topsoiled and overburden-covered banks. This is considered essential in improving soil management and designing accurate erosion control plans.

José M. Nicolau

1996-01-01

319

Study of Single-Responsibility Concepts for Water Pollution Control Projects.  

National Technical Information Service (NTIS)

Characteristics of various types of construction projects are summarized. Method and time of contractor selection, level of contractor responsibility, degree of project control, potential for schedule compression, firmness of cost estimate, availability o...

1974-01-01

320

Company-wide project management: the planning and control of programmes of projects of different type  

Microsoft Academic Search

It has been perceived wisdom that where an organisation is undertaking a portfolio of projects, they should use a common approach to the management of all projects in the programme. Presumed benefits include comparable progress reporting, and consistent calculation of resource requirements enabling sharing of resources. People can also move freely between projects without having to learn a new management

John H Payne; J Rodney Turner

1999-01-01

321

Project W-320 SAR and process control thermal analyses  

SciTech Connect

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

Sathyanarayana, K.

1997-06-19

322

Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion (FBC) system. Technical progress report No. 12  

SciTech Connect

This technical report summarizes the research work performed and progress achieved during the period of July 1, 1995 to October 30, 1995. The characteristics of resistant coatings were determined and related to metal wastage of in-bed tubes in FBC under various laboratory test conditions, The tests were conducted at high impact velocity, 30 m/s, and short exposure time (4 hours) to minimize oxidation of surrounding surface specimens. No oxidation layer founded on the worn surfaces of AISI 1018 carbon steel, The eroded surfaces and cross sections of coatings tested at high velocity were investigated, The surfaces of coating specimens were eroded through a combined mechanism of brittle and ductile modes, These mechanical properties of materials are strongly dependent on the composition and microstate of materials, rather than to their hardness, For high velocity testing, all of the coatings exhibited {open_quotes}brittle behavior{close_quotes}, i.e., the erosion rate at shallow angles was higher than at steep angles and maximum erosion rate at impact angle of 90{degrees}. Tests will be continued and compared with erosion test results for different thermal sprayed coatings.

Lee, S.W.

1995-10-01

323

Pre-Project Water Quality of Two Watershed Streams in the Demonstration Erosion Control (DEC) Project in the Yazoo Basin of Mississippi: 1985-1987,  

National Technical Information Service (NTIS)

Two bluffline streams were sampled weekly for two years to establish water quality cycles as part of pre-construction evaluation of a watershed scale comprehensive land treatment and channel stability program. The interagency program was designed to demon...

C. M. Cooper S. S. Knight L. L. McDowell

1989-01-01

324

Landslides, Earthquakes, and Erosion  

NASA Astrophysics Data System (ADS)

In this paper, we quantify the role of landslides in erosion and in particular, the role of earthquakes to landslides to erosion. A landslide event consists of single to tens of thousands of landslides associated with a trigger, such as an earthquake, sudden snowmelt, or extended precipitation. We have previously introduced a general landslide distribution for landslide events and also a corresponding landslide-event magnitude scale, ML = log(NLT), with NLT the total number of landslides associated with the landslide event. The magnitude mL can be determined from both substantially `complete' inventories and partial inventories of the largest landslides in the event. Equivalent magnitude values can also be obtained for historical landslide inventories, which represent the sum of many landslide events over periods of one to many thousands of years or more. We believe that our landslide distribution does a rough quantification of the total area (and volume) of landslides that occur for landslide events of different magnitudes, and use this distribution to relate our landslide magnitude to total landslide volume. Using estimated recurrence intervals for three landslide event inventories, we have inferred regional erosion rates due to landslides for the Northridge earthquake-triggered, Umbria (Italy) snowmelt-triggered, and Guatemala heavy-rain triggered events, as 0.1, 0.4, and 2.5 mm yr-1, respectively. Comparing historical inventories to our general landslide event distribution, we have made extrapolations and estimated total landslide volumes associated with two historical inventories in Italy and Japan. Using estimates for time intervals over which these historical landslides accumulated, the associated long-term erosion rates were found to be 1.0 mm yr-1 in Umbria, Italy and 2.2 mm yr-1 in Japan. We then use an empirical relationship between total landslide volume and earthquake magnitude to determine analytic relationships between earthquake magnitude and the associated landslide event magnitude, area and volume of the largest landslide triggered, and total area of all landslides triggered. Using the Gutenberg--Richter frequency-magnitude relation for regional seismicity, we analytically relate the seismically-induced erosion rate to the regional seismic intensity and the moment magnitude of the largest regional earthquake. We find that typical seismically-induced erosion rates in very active subduction zones is ? 0.2--2 mm yr-1 and adjacent to plate boundary strike-slip zones ? 0.01--0.2 mm yr-1.

Malamud, B. D.; Turcotte, D. L.; Guzzetti, F.; Reichenbach, P.

2003-12-01

325

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.

Montgomery, David R.

2007-01-01

326

Fuzzy Representation of Soil Erosion  

NASA Astrophysics Data System (ADS)

Fuzzy representation is a productive method to explain the natural processes so that it is near to linguistic form and it is also applicable to estimate the environmental processes in where the uncertainty in information is high. As models proposed to estimate soil erosion also have uncertainties and fuzzy inference system is more flexible in describing the relationship between soil erosion and other factor, especially in managing data and model uncertainties. in the research, it is used simplified model of revised Universal Soil Loss Equation (RUSLE) to estimate soil erosion in dry lands of Kashan area in Central Iran . Then to discover the systematic (IF-Then) rules in soil erosion process, we used inductive reasoning method to discover rules of the causing agents of erosion such as rainfall erosivity, topography factors, soil erodibility , then highly supported rules converted to fuzzy rules. It is resulted that the application of fuzzy inference system for erosion evaluation is applicable in regional level.

Komaki, Ch. B.; Kainz, W.; Alavi Panah, S. K.; Matinfar, H. R.

2009-04-01

327

Soil erosion and agricultural sustainability.  

PubMed

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 ( approximately 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

2007-08-08

328

Modeling the impact of live barriers on soil erosion in the Pairumani sub-catchment, Bolivia  

Microsoft Academic Search

Abstract Process based soil erosion models, such as the European Soil Erosion Model (EUROSEM), have the potential to be used for the extrapolation to the catchment scale of plot scale investigations into the effectiveness of soil conservation practices. In this paper results from plot scale studies on the effectiveness of live barriers for soil erosion control, on steep mountainsides in

John Quinton; Felix Rodriguez

329

Oxidation-erosion of metals and alloys: Models, verification, and prediction  

Microsoft Academic Search

Models have been developed for synergistic interaction of oxidation and erosion of metals and alloys. The models are based on an extension of earlier work on paralinear kinetics in which oxidation of metal is assumed to be diffusion controlled, and erosion is assumed to result in a uniform removal of materials. Predictions of oxidaion-erosion behavior as a function of temperature

Yung Y. Liu; K. Natesan

1988-01-01

330

Soil Erosion: Advanced Crop and Soil Science. A Course of Study.  

ERIC Educational Resources Information Center

The course of study represents the last of six modules in advanced crop and soil science and introduces the agriculture student to the topic of soil erosion. Upon completion of the two day lesson, the student will be able to: (1) define conservation, (2) understand how erosion takes place, and (3) list ways of controlling wind and water erosion.…

Miller, Larry E.

331

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...

332

Negligible Soil Erosion After Wildfire Disturbance: Role of the Duff Layer  

Microsoft Academic Search

Wildfires are generally thought to result in increased soil erosion in the immediate post-disturbance years, but many unanswered questions remain regarding the controls of erosional response in different regional settings. Post-fire soil erosion is most often studied and reported in regions where noteworthy erosion occurs. In many of these studies, it may be the case that the duff layer has

Yvonne Martin; Edward Johnson; Joan Gallaway

2010-01-01

333

Hillslope Angle, Channel Steepness and Millennial Erosion Rates in the San Gabriel Mountains, CA  

Microsoft Academic Search

Steeper hillslopes have long been associated with higher erosion rates. Similarly, channel steepness when normalized for drainage area is expected to be controlled primarily by uplift rate, climate, and lithology. Importantly, it has been proposed that above relatively modest erosion rates, hillslope angle becomes insensitive to further increases in erosion rates as channels continue to steepen. Here we use new

R. A. Dibiase; A. M. Heimsath; K. X. Whipple

2008-01-01

334

Cavitation erosion of cobalt based STELLITE alloys, cemented carbides and surface treated low alloy steels  

Microsoft Academic Search

Results are given for erosion-resistance tests involving several STELLITE alloys, cemented carbides and surface-treated alloy steels. It is shown that the cobalt-rich, solid-solution phase of the STELLITE alloys is the basis of their erosion resistance, while the erosion of cemented carbides is predominantly controlled by the binder phase. It is also found that nickel-based tungsten carbides are more erosion-resistant than

C. J. Heathcock; A. Ball; B PROTHEROE

1981-01-01

335

Toothpaste and erosion.  

PubMed

Dental erosion develops from the chronic exposure to non-bacterial acids resulting in bulk mineral loss with a partly demineralised surface of reduced micro-hardness. Clinical features are loss of surface structures with shallow lesions on smooth surfaces and cupping and flattening of cusps; already in early stages, coronal dentine often is exposed. Not only enamel, but also dentine is therefore an important target tissue for anti-erosion strategies. The main goal of active ingredients against erosion is to increase the acid resistance of tooth surfaces or pellicles. The challenge with toothpastes is that abrasives, otherwise beneficial in terms of cleaning properties, may counteract the effects of active ingredients. Fluoride toothpastes offer a degree of protection, but in order to design more effective formulations, active ingredients in addition to, or other than, fluorides have been suggested. Polyvalent metal cations, Ca/P salts in nano-form, phosphates, proteins, and various biopolymers, e.g. chitosan, are substances under study. The complex combined action of active ingredients and abrasives on the dental hard tissues, and the role of excipients of complex toothpaste formulations are not yet fully understood. Current evidence is flawed by the diversity of experimental designs, and there is no knowledge from clinical studies with patients so far. However, research results indicate that there is potential to develop effective toothpastes in this field. As the prevalence of initial erosive lesions particularly in younger age groups is high in some countries, such strategies would be of great importance for maintaining oral health. PMID:23817062

Ganss, Carolina; Schulze, Katja; Schlueter, Nadine

2013-06-28

336

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

337

Statistics of rocky coast erosion and percolation theory  

NASA Astrophysics Data System (ADS)

The dynamics of rocky coasts is an erratic phenomenon featuring numerous small erosion events, but sometimes large dramatic collapses. In this sense, its study should not limit or rely on average erosion rates. Recent studies, based on historical as well as recent data, have indicated that the frequency of magnitude of erosion events display long tail distribution, similar to what observed in landslide. In other words the time evolution of a coast morphology does not enter the classical category of Gaussian process, but rather that of critical systems in physics. We recently proposed a minimal dynamical model of rocky coast erosion which is able to reproduce the diversity of rocky coast morphologies and their dynamics. This model is based on a single, simple ingredient, the retroaction of the coast morphology on the erosive power of the sea. It follows from the idea that erosion can spontaneously create irregular seashores, but, in turn, the geometrical irregularity of the coast participates to the damping of sea-waves, decreasing the average wave amplitude and erosive power. The resulting mutual self-stabilization dynamics of the sea erosion power and coastal irregular morphology leads spontaneously the system to a critical dynamics. Our results indicate then that rocky coast erosion and the statistical theory of percolation are closely related. In this framework, the sometimes fractal geometry of coastlines can be recovered and understood in terms of fractal dimension of the external perimeter of a percolation cluster. From a more practical point of view, the analogy with percolation interfaces means that the coast constitutes a strong, but possibly fragile, barrier to sea erosion, emerging from a self-organised selection process. Accordingly, the effect of a slow weathering degradation of the rocks mechanical properties, as well as other perturbations from natural or human cause, can trigger random and large erosion events difficult to predict and control. To the extent that these ideas apply, natural coasts should be "preserved" and managed with care.

Baldassarri, A.; Sapoval, B.

2012-04-01

338

An integrated concept for design project planning and design flow control  

Microsoft Academic Search

This paper presents a novel approach supporting administrative tasks within the lifecycle of design projects. Based upon comprehensive models of design environments and design activities it combines techniques known from project management and mechanisms for design flow con- trol. As a result it allows the planning, controlling and reviewing of design projects and supports algorithmic esti- mation of task durations

Michael Ryba; Utz G. Baitinger

1996-01-01

339

The CASCIDA project: a computer-aided system control for interactive design and analysis  

Microsoft Academic Search

Since 1985 at Setif University, Algeria, the author has initiated and worked on a project which was aimed at the development of a CACSD System. The results of the CASCIDA project (Computer Aided Systems Control for Interactive Design and Analysis) are briefly described. More importantly and over the years, this project laid down the basis for, and the nurturing of,

Aboubekeur HAMDI-CHERIF

1994-01-01

340

Projects of the Pollution Control Analysis Section, November 1972.  

National Technical Information Service (NTIS)

This report provides a listing of all active and completed research, development and demonstration projects funded by the Environmental Protection Agency and its predecessor agencies through the Office of Research and Monitoring, Technology Division, Appl...

E. P. Hall

1972-01-01

341

Project planning and control in practice, firm or fiction? The treatment of uncertainty in project planning and control  

Microsoft Academic Search

The authors investigate uncertainties in the world of projects, how they are usually dealt with, and how they could be dealt with. They first review deterministic planning, conclude that the future is by definition uncertain, and discuss methods to evaluate and reduce uncertainty, as well as the method of segmented planning in a phased project. They then consider the use

K. Sietsma; M. B. Sietsma

1991-01-01

342

Vetiver Grass: A Thin Green Line against Erosion.  

National Technical Information Service (NTIS)

Vetiver, a deeply rooting, persistent tropical grass, has for decades controlled erosion at sites in Fiji, India, and the Caribbean. The report, based on a literature review, personal contacts, site visits, and correspondence with experts in agronomy, for...

1993-01-01

343

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 datasets 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.

Mezõsi, G.; Blanka, V.; Bata, T.; Kovács, F.; Meyer, B.

2013-09-01

344

Rain simulator role in creating of Erosion Potential Method (EPM)  

NASA Astrophysics Data System (ADS)

Soil erosion is a natural process that depends on many variables factor. Unlike the other factors rain is meteoric phenomenon of short duration and intensity variation. This feature caused the application of rain simulators in the field of erosion research. During the development of erosion potential method, it was concluded that there is too large dissipation of observed erosion data. The first use of simulators did not give better results, because the rain simulator had no impact on other factors of erosion. Therefore, the research continued in the laboratory where the use of rain simulators takes a series of data for various intensity and duration of rain. Other factors are controlled for each series of measurements were constant. These data enabled more precise definition of the numerical coefficients and procedures of erosion potential method (EPM), which is known in the scientific public as Gavrilovic method. The paper will appear applied a combination of experimental erosion field and laboratory measurements obtained using rain simulators. Key words: Erosion, torrents, meteorology, climate, Rain simulator

Gavrilovic, Zoran; Stefanovic, Milutin; Milovanovic, Irina

2010-05-01

345

Inhibition of erosive wear by fluoride varnish.  

PubMed

It has been suggested that fluoride products with a protective mechanical component are advantageous in the prevention of erosive wear. The aim of this study was to evaluate in situ the effect of fluoride varnish (FV) in the prevention of wear due to erosion and combined erosion and toothbrush abrasion. Eleven volunteers wore for 3 weeks, during working hours, appliances containing 2 control and 2 FV-treated human enamel samples. Erosion took place extraorally 3 times a day (5 min) in the soft drink Sprite. At the end of each experimental day one control and one FV sample (C-er+abr and FV-er+abr) were brushed (5 s) with fluoridated dentrifice. The remaining control and FV sample (C-er and FV-er) were left unbrushed. Enamel volume loss was quantified by optical profilometry at day 5, 10 and 15. A statistically significant progression in enamel loss was found for the C-er, C-er+abr and FV-er+abr groups (p < 0.001, p < 0.001 and p = 0.001, respectively) but not for the FV-er group (p = 0.053). The values of cumulative normalized volume loss (x10(8) mum) at day 15 were: C-er 5.53 +/- 2.14, C-er+abr 5.70 +/- 2.07, FV-er 0.79 +/- 0.67 and FV-er+abr 2.76 +/- 1.35. The FV-er and FV-er+abr groups showed significant lower volume loss than the C-er group (p < 0.001 and p = 0.005, respectively) and the C-er+abr group (p < 0.001 and p = 0.002, respectively). The results indicate that fluoride varnish is effective in the reduction of erosive wear. PMID:17167261

Vieira, A; Jager, D H J; Ruben, J L; Huysmans, M C D N J M

2007-01-01

346

Ex-post evaluation analysis of flood control engineering system based on grey relation projection method  

Microsoft Academic Search

For those modern construction projects in the large-scale flood control engineering system built with great investment, they are of great importance. In the evaluation of these projects, many of their effects are concerned. To study the EX-Post Evaluation Analysis (PEA) of Flood Control Engineering System (FCES) from the viewpoint of sustainable development is an urgent need for water resource conservancy.

Yi Xiao; Dongguo Shao; Yunqing Wu

2007-01-01

347

Workflow technology-based monitoring and control for business process and project management  

Microsoft Academic Search

In this paper the application of workflow technology to monitor, control and coordinate business processes and projects is proposed. The conceptual characteristics of processes and projects as well as their management needs in the functions of planning, execution, monitoring and control are compared. The general design of the proposed system is then developed, with an application example. The proposed monitoring

Heloisa Martins Shih; Mitchell M Tseng

1996-01-01

348

[Problems in the ascertainment of sizes of the control areas of natural gas industrial projects].  

PubMed

The paper reviews the problems in the ascertainment of sizes of the control areas of industrial projects, including those of natural gas industry, and analyzes discrepancies in the normative-legal base. The historical aspects and results of substantiating the safe sizes of control areas for the projects of the Orenburg oil-gas condensate field are presented. PMID:19802941

Bystrykh, V V

349

Control in outsourced ISD projects based on psychological contract: a multiple case study  

Microsoft Academic Search

Purpose – The paper seeks to investigate the effects of psychological contract on control mechanisms in outsourced ISD projects, based on control theories and psychological contract theories. Design\\/methodology\\/approach – The paper is a multiple case study involving five outsourced projects completed by one of the largest and most successful telecommunication vendors in China. The company was the client in three

Xiaoyan Li; Jiye Mao; Jing Qian

2010-01-01

350

Soil erosion, policy and management in China coastal zone  

NASA Astrophysics Data System (ADS)

The coastal zone is very important in the world. China coastal zone was granted the first priority of developing economy in the late 1980s. Since then, high population density and rapid economic development hace caused intensive changes of LUCC in this zone. Those changes have lead to land degradation. Besides, China governments launched series of projects and policy to improve such problems. Those will inevitably cause to diverse spatial dynamics of land degradtion. However, the state of land degradation in certain time is still unknown. Soil erosion is an important indicator of land degradation.Therefore, we use RS images?RUSLE model to anlyze the spatial pattern of soil erosion for 2000. By spatial analysis, we found that soil erosion in China coastal zone is not serious. Widespread soil erosion is only occurred on coastal zones in Shandong, Hainan and werstern Guangdong Province. Although rainfall eosivity factor(R) is higher in southern coastal zone, erosion tends to occur on the slopes with lower LS values in northern coastal zone than southern coastal zone. Goevernments have enforced some policy to reduce the extent of soil erosion by conversion of farmland to woodland and barren mountains to woodland. But the difference between southern and northern coastal zone is still not realized. To improve soil eorosion in those areas, we should let governments put more funds to increase vegetation cover in north. Such study will provide helpful suggestions for governments to prevent soil erosion in coastal zone.

Lu, Qingshui; Gao, Zhiqiang; Chen, Qiao; Ning, Jicai; Shi, Runhe; Gao, Wei

2013-09-01

351

Experimental Erosion of Calcareous Ooze  

Microsoft Academic Search

Flume experiments on the erosion of abyssal calcareous ooze in shallow uniform flows of sea water show that erosion velocities range from 7-10 cm\\/sec soon after rapid deposition of the bed to 15-20 cm\\/sec after a few tens of hours. Continuing erosion produces shallow irregular longstream linearions but no sediment ripples. On the assumption of a hydrodynamically smooth boundary in

J. B. SOUTI-IARD; R. A. Young; C. D. Hollister

1971-01-01

352

The Monitoring Erosion of Agricultural Land and spatial database of erosion events  

NASA Astrophysics Data System (ADS)

In 2011 originated in The Czech Republic The Monitoring Erosion of Agricultural Land as joint project of State Land Office (SLO) and Research Institute for Soil and Water Conservation (RISWC). The aim of the project is collecting and record keeping information about erosion events on agricultural land and their evaluation. The main idea is a creation of a spatial database that will be source of data and information for evaluation and modeling erosion process, for proposal of preventive measures and measures to reduce negative impacts of erosion events. A subject of monitoring is the manifestations of water erosion, wind erosion and slope deformation in which cause damaged agriculture land. A website, available on http://me.vumop.cz, is used as a tool for keeping and browsing information about monitored events. SLO employees carry out record keeping. RISWC is specialist institute in the Monitoring Erosion of Agricultural Land that performs keeping the spatial database, running the website, managing the record keeping of events, analysis the cause of origins events and statistical evaluations of keeping events and proposed measures. Records are inserted into the database using the user interface of the website which has map server as a component. Website is based on database technology PostgreSQL with superstructure PostGIS and MapServer UMN. Each record is in the database spatial localized by a drawing and it contains description information about character of event (data, situation description etc.) then there are recorded information about land cover and about grown crops. A part of database is photodocumentation which is taken in field reconnaissance which is performed within two days after notify of event. Another part of database are information about precipitations from accessible precipitation gauges. Website allows to do simple spatial analysis as are area calculation, slope calculation, percentage representation of GAEC etc.. Database structure was designed on the base of needs analysis inputs to mathematical models. Mathematical models are used for detailed analysis of chosen erosion events which include soil analysis. Till the end 2012 has had the database 135 events. The content of database still accrues and gives rise to the extensive source of data that is usable for testing mathematical models.

Kapicka, Jiri; Zizala, Daniel

2013-04-01

353

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

354

Soil erosion and the global carbon budget  

Microsoft Academic Search

Soil erosion is the most widespread form of soil degradation. Land area globally affected by erosion is 1094 million ha (Mha) by water erosion, of which 751 Mha is severely affected, and 549 Mha by wind erosion, of which 296 Mha is severely affected. Whereas the effects of erosion on productivity and non-point source pollution are widely recognized, those on

R. Lal

2003-01-01

355

Distributed soil erosion simulation for effective erosion prevention  

Microsoft Academic Search

We present a bivariate model of erosion, sediment transport, and deposition by overland flow, designed for complex terrain, soil, and cover conditions. We use a Green's function Monte Carlo method to solve the underlying continuity equations, leading to improved robustness and implementation efficiency. By deriving the relationship between the terrain shape and erosion\\/deposition pattern, we clarify the physical interpretation of

Lubos Mitas; Helena Mitasova

1998-01-01

356

Epic Erosion Along Newly Constructed Roads in Yunnan, China  

NASA Astrophysics Data System (ADS)

The recent expansion and construction of new mountain roads in northwestern Yunnan Province, China, poses problems related to landslides and surface erosion that are impacting the headwaters of three great river systems: the Salween, Mekong, and Yangtze. Many of these newer roads are simply blasted into unstable hillsides with virtually no attention paid to optimal road location, construction practices, and erosion control measures. During summer 2006, seven people traveling in a minivan along a newly constructed road to Weixi were killed by a landslide. A survey conducted along a this 23.5 km road section (4 yr old) in the headwaters of the Mekong River revealed epic levels of landslides and surface erosion. Based on a preliminary survey, the road erosion was categorized as moderately severe, severe, or very severe, and a representative 0.75 to 0.90 km stretch of road was then surveyed for both landslide (based on dimensional analysis) and surface erosion (based on soil pedestal height). Average mass wasting rates (9608 t ha-1yr-1) along the road were more than 13 times higher than surface erosion (720 t ha-1yr-1), even though surface erosion rates are among the highest reported for disturbed lands. Dry ravel constituted a minor proportion of the mass wasting: 4% in the severe erosion section of the road and 0.5-0.6% in the moderately severe and very severe sections. For the very severe erosion road section (6 km long), estimated landslide erosion alone was > 33,000 t ha- 1yr-1, 620 times the average landslide erosion from forest roads built in unstable terrain in western North America. These levels of landslide erosion along the Weixi road are the highest ever documented and are somewhat representative of erosion along new mountain roads in this region of Yunnan. Sediment produced from roads is highly connected to fluvial systems; we estimate that 80-95% of the direct sediment contributions into the headwaters of these rivers are attributable to road erosion and landslides. These epic sediment loads represent cumulative effects that may persist in these important transnational rivers for decades.

Sidle, R. C.; Kono, Y.; Yamaguchi, T.

2007-05-01

357

Controlling Landfill Emissions For Environmental Protection : Mid Auchencarroch Experimental Project  

Microsoft Academic Search

This paper assesses the long term behaviour of Mid Auchencarroch experimental landfill site in Scotland, based on characteristic landfill biodegration parameters, making useful conclusions. and analyzes the effects of waste pretreatment and landfill management techniques on landfill emissions and waste biodegradation processes. The biodegradation of Mid Auchencarroch Experimental Landfill Project is studied in four different cells with different waste input

Telemachus C. Koliopoulos; D. M. Georgia Koliopoulou

358

Novel Shutter Glass Control for Simultaneous Projection and Picture Acquisition  

Microsoft Academic Search

Virtual reality offers completely new possibilities for collaborative work over distributed environments. To enable collaborative work, it is necessary that both, virtual objects as well as the other users, can be seen simultaneously in real -time. A novel technique is necessary to overcome the contradiction of darkness and light for image projection and video acquisition, respectively. A stroboscopic light and

Andreas M. Kunz; Christian P. Spagno

2001-01-01

359

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

National Technical Information Service (NTIS)

The now-cancelled Constellation Program included the Orion, Altair, and Lunar Surface Systems project offices. The first two elements, Orion and Altair, were planned to be manned space vehicles while the third element was much more diverse and included se...

R. A. Stephan

2011-01-01

360

NIF Projects Controls and Information Systems Software Quality Assurance Plan  

Microsoft Academic Search

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

Fishler

2011-01-01

361

Environmental Management Services Project Enhances Infection Control Program  

Microsoft Academic Search

ISSUE: In 2003, the Veterans Healthcare Administration (VHA) initiated a “Goalsharing” employee incentive program. This program was designed to improve performance and communication, enhance teamwork, increase quality, and promote pride in work. Teams were asked to identify a process improvement goal consistent with one of the objectives of VA Region 10, the local division, or VA national.PROJECT: The Environmental Management

P. Hawkins; H. Phillips; T. Reinhart; R. Fletcher; N. Moore; W. Nickol; E. Brown

2004-01-01

362

Control Structure in Project-Based Asynchronous Collaborative Learning  

Microsoft Academic Search

Although project-based, collaborative learning (PBCL) activities have been established as effective learning experiences, they have been shown to be difficult to implement, especially in an asynchronous, distributed environment. Students and faculty alike have shown resistance to team-based exercises, citing numerous management concerns such as equitably distributing the work, assessing the performance of the individuals comprising the team, and resolving conflicts

Timothy J. Ellis; William Hafner

2007-01-01

363

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

364

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

365

New Hampshire Title XIX Quality Control Project. Third Year Report.  

National Technical Information Service (NTIS)

The report is the final of the Title XIX Demonstration Project which was initiated in October 1975 with the purpose of testing the concept of using an Error Prone Profiles System to improve the management of the eligibility determination process for the M...

A. Friedberg B. Cummings J. Cummings

1979-01-01

366

Descending projections from the ventrolateral medulla and cardiovascular control  

Microsoft Academic Search

Antidromic responses were evoked in neurones in nucleus paragigantocellularies lateralis (PGL) by stimulation of the ipsilateral ventrolateral white matter or the contralateral dorsolateral white matter at T13-L1 in the cat. Estimated conduction velocities in the spinally projecting axons ranged from 5.0–61 m\\/s.

T. A. Lovick

1985-01-01

367

DiMES divertor erosion experiments on DIII-D  

SciTech Connect

The DiMES (Divertor Material Evaluation Studies) mechanism allows insertion of material samples to the lower divertor floor of the DIII-D tokamak. The main purpose of these studies is to measure erosion rates and redeposition mechanisms under tokamak divertor plasma conditions in order to obtain a physical understanding of the erosion/redeposition processes and to determine its implications for fusion power plant plasma facing components. Thin metal films of Be, W, V, and Mo, were deposited on a Si depth-marked graphite sample and exposed to the steady-state outer strike point on DIII-D. A variety of surface analysis techniques are used to determine the erosion/redeposition of the metals and the carbon after 5--15 seconds of exposure. These short exposure times ensure controlled exposure conditions and the extensive array of DIII-D divertor diagnostics provide a well characterized plasma for modeling efforts. Erosion rates and redeposition lengths are found to decrease with the atomic number of the metallic species, as expected. Under these conditions, the peak net erosion rate for carbon is {approximately} 4 nm/s, with the erosion following the ion flux profile. Comparisons of the measured carbon erosion with REDEP code calculations show good agreement for both the absolute net erosion rate and its spatial variation. Measured erosion rates of the metals are smaller than predicted for sputtering from a bare metal surface, apparently due to effects of carbon deposition on the metal surface. Visible spectroscopic measurements of singly ionized Be have determined that the erosion process reaches steady-state during the exposure.

Whyte, D.G. [Institut National de la Recherche Scientifique, Varennes, PQ (Canada); Brooks, J.N. [Argonne National Lab., IL (United States); Wong, C.P.C.; West, W.P. [General Atomics, San Diego, CA (United States); Bastasz, R.; Wampler, W.R. [Sandia National Labs., Albuquerque, NM (United States); Rubinstein, J. [Illinois Univ., Urbana, IL (United States)

1996-06-01

368

Project W-211, initial tank retrieval systems, retrieval control system software configuration management plan  

Microsoft Academic Search

This Software Configuration Management Plan (SCMP) provides the instructions for change control of the W-211 Project, Retrieval Control System (RCS) software after initial approval\\/release but prior to the transfer of custody to the waste tank operations contractor. This plan applies to the W-211 system software developed by the project, consisting of the computer human-machine interface (HMI) and programmable logic controller

1999-01-01

369

Improving Software Development Project Team Performance: A Web-based Expert Support System for Project Control  

Microsoft Academic Search

Delivered software is often late and over budget, while offering fewer features than requested by the user. Many software developers have difficulties establishing and adhering to a project plan and in delivering what the user wants within the budget and schedule. Developers also have difficulty in obtaining user involvement in the development process. This paper discusses a Web- enabled expert

Donna Dufner; Ojoung Kwon; Aaron Doty

1999-01-01

370

Using hilltop curvature to derive the spatial distribution of erosion rates  

NASA Astrophysics Data System (ADS)

Erosion rates dictate the morphology of landscapes, and therefore quantifying them is a critical part of many geomorphic studies. Methods to directly measure erosion rates are expensive and time consuming, whereas topographic analysis facilitates prediction of erosion rates rapidly and over large spatial extents. If hillslope sediment flux is nonlinearly dependent on slope then the curvature of hilltops will be linearly proportional to erosion rates. In this contribution we develop new techniques to extract hilltop networks and sample their adjacent hillslopes in order to test the utility of hilltop curvature for estimating erosion rates using high-resolution (1 m) digital elevation data. Published and new cosmogenic radionuclide analyses in the Feather River basin, California, suggest that erosion rates vary by over an order of magnitude (10 to 250 mm kyr-1). Hilltop curvature increases with erosion rates, allowing calibration of the hillslope sediment transport coefficient, which controls the relationship between gradient and sediment flux. Having constraints on sediment transport efficiency allows estimation of erosion rates throughout the landscape by mapping the spatial distribution of hilltop curvature. Additionally, we show that hilltop curvature continues to increase with rising erosion rates after gradient-limited hillslopes have emerged. Hence hilltop curvature can potentially reflect higher erosion rates than can be predicted by hillslope gradient, providing soil production on hilltops can keep pace with erosion. Finally, hilltop curvature can be used to estimate erosion rates in landscapes undergoing a transient adjustment to changing boundary conditions if the response timescale of hillslopes is short relative to channels.

Hurst, Martin D.; Mudd, Simon M.; Walcott, Rachel; Attal, Mikael; Yoo, Kyungsoo

2012-06-01

371

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

372

Noise prediction and control of Pudong International Airport expansion project  

Microsoft Academic Search

The Environmental Impact Assessment (EIA) process of the third runway building project of Pudong International Airport is\\u000a briefly introduced in the paper. The basic principle, the features, and the operation steps of newly imported FAA’s Integrated\\u000a Noise Model (INM) are discussed for evaluating the aircraft noise impacts. The prediction of the aircraft noise and the countermeasures\\u000a for the noise mitigation

Bin Lei; Xin Yang; Jianguo Yang

2009-01-01

373

FEM analysis of erosive wear  

Microsoft Academic Search

Surface damage caused by the impact of dispersed particles in gas or liquid flow is called “erosion”. Much attention has been paid to this phenomenon as one of the most serious problems to be solved, particularly concerning pipe-bends or valves in pneumatic conveying systems. But the phenomena of erosive wear are so complicated and vary depending on the factors of

K. Shimizu; T. Noguchi; H. Seitoh; M. Okada; Y. Matsubara

2001-01-01

374

Sliding Erosion Mechanism and Measurement  

Microsoft Academic Search

This paper describes the shortcomings in the determination of wear in equipment where the predominant wear mechanism is that due to sliding erosion with a very low angle of impact. A description is given of the design and operation of the novel erosion tester which overcomes the limitations of existing testers.Results with the spinning loop tester have shown that the

S. F. Scieszka

1992-01-01

375

Nocturnal lagophthalmos and recurrent erosion.  

PubMed Central

The symptoms and corneal changes caused by sleeping with one or both eyes open are described in 102 patients. The clinical picture is identical to that of the microform recurrent erosion. The close relationship between the micro- and macro-forms of recurrent corneal erosion suggests that the latter condition is also precipitated by nocturnal lagophthalmos. Images

Sturrock, G. D.

1976-01-01

376

Rangeland Hydrology and Erosion Model  

NASA Astrophysics Data System (ADS)

Soil loss rates on rangelands are considered one of the few quantitative indicators for assessing rangeland health and conservation practice effectiveness. An erosion model to predict soil loss specific for rangeland applications has been needed for many years. Most erosion models were developed from croplands where the hydrologic and erosion processes are different, largely due to much higher levels of heterogeneity in soil and plant properties at the plot scale and the consolidated nature of the soils. The Rangeland Hydrology and Erosion Model (RHEM) was designed to fill that need. RHEM is an event-based model that estimates runoff, erosion, and sediment delivery rates and volumes at the spatial scale of the hillslope and the temporal scale of a single rainfall event. It represents erosion processes under normal and fire-impacted rangeland conditions, it adopts a new splash erosion and thin sheet-flow transport equation developed from rangeland data, and it links the model hydrologic and erosion parameters with rangeland plant communities by providing a new system of parameter estimation equations based on 204 plots at 49 rangeland sites distributed across 15 western U.S. states. Recent work on the model is focused on representing intra-storm dynamics, using stream-power as the driver for detachment by flow, and deriving parameters for after-fire conditions.

Nearing, Mark; Pierson, Fred; Hernandez, Mariano; Al-Hamdan, Osama; Weltz, Mark; Spaeth, Ken; Wei, Haiyan; Stone, Jeff

2013-04-01

377

Helicobacter pylori and Gastric Erosions  

Microsoft Academic Search

Background\\/Aims:Helicobacter pylori is considered to be the primary cause of most forms of gastritis, but its role as a causative agent in gastric erosions is unclear. The aim of this study was to estimate the prevalence of gastric erosions and H. pylori infection in asymptomatic volunteers. Methods: 175 asymptomatic subjects underwent upper gastrointestinal endoscopy. Antral biopsies were taken for bacterial

Frank S. Lehmann; Eberhard L Renner; Beat Meyer-Wyss; Clive H. Wilder-Smith; Luca Mazzucchelli; Charles Ruchti; Jürgen Drewe; Christoph Beglinger; Hans S. Merk

2000-01-01

378

Integrating Aesthetic and Sustainable Principles in Stream Reclamation Projects  

Microsoft Academic Search

Stream regularization and the use of rigid, inert construction materials in engineering projects are not adequate for sustainable planning and development. Biotechnical stream protection and erosion control is characterized by the conjunctive use of live vegetation with retaining structures and revetments. The present work explores some of the issues relating aesthetic ideals and values, with sustainability principles and reclamation measures

BIBIANA RODRIGUES RAMOS; THOMAS PANAGOPOULOS

379

Dental erosions in subjects living on a raw food diet.  

PubMed

The aim of the study was to investigate the frequency and severity of dental erosions and its association with nutritional and oral hygiene factors in subjects living on a raw food diet. As part of a larger dietary study 130 subjects whose ingestion of raw food was more than 95% of the total food intake were examined. The median duration of the diet was 39 (minimum 17, maximum 418) months. Before the clinical examination, the participants answered questionnaires and recorded their food intake during a 7-day period. Dental erosions were registered using study models. As a control 76 sex- and age-matched patients from our clinic were randomly selected. The raw food diet records showed the median daily frequency of ingesting citrus fruit to be 4.8 (minimum 0.5, maximum 16.1). The median intake of fruit was 62% (minimum 25%, maximum 96%) of the total, corresponding to an average consumption of 9.5 kg of fruit (minimum 1.5, maximum 23.7) per week. Compared to the control group subjects living on a raw food diet had significantly (perosions. Only 2.3% of the raw food group (13.2% of the controls) had no erosive defects, whereas 37.2% had at least one tooth with a moderate erosion (55.2% of the controls) and 60.5% had at least one tooth with a severe erosion (31.6% of the controls). Within the raw food group no significant correlation was found between nutrition or oral health data and the prevalence of erosions. Nevertheless, the results showed that a raw food diet bears an increased risk of dental erosion compared to conventional nutrition. PMID:9831783

Ganss, C; Schlechtriemen, M; Klimek, J

1999-01-01

380

Is splash erosion potential species specific? Measuring of splash erosion potential under forest in different succession stages along a biodiversity gradient in the humid subtropics  

NASA Astrophysics Data System (ADS)

It is widely accepted that (forest) vegetation is a key control for the type and intensity of soil erosion. The current paradigm is that natural or quasi-natural vegetation protects the soil from erosion and that agricultural vegetation or land use generally enhances erosion. The latter was in focus of most research during the last decades and less interest was paid on natural systems, which are more difficult to study. Nevertheless, afforestation is widely used as a measure of soil protection against soil erosion. Rainfall can be highly erosive particularly in the humid subtropics. Regarding climate change, also precipitation regime may change in direction to even more severe storms and higher rainfall intensities; it is a research field of growing importance. Key mechanisms of a vegetation cover in reducing or enhancing erosion are modifications of drop-size distribution, retention of raindrop impact on the soil and changes in amount and spatial distribution of rainfall at the ground surface. Controlling determinants are rainfall intensity, drop size distribution, drop fall velocity, height of the canopy as well as density of the canopy, crown and leaf traits, LAI and coverage by a litter layer. Large drops are supposed to be significant sources of splash detachment in forests (Brandt 1989; Vis 1986). However, the mechanisms of reducing (or enhancing?) splash detachment under forest in relation to species richness and species composition are not well understood. Some studies indicate that raindrop impact is species specific (Calder 2001; Nanko et al. 2006) and some neglect the effects of species specific impacts (Foot & Morgan 2005). Our research uses different methods of rainfall characterization (splash cups, tipping-bucket rain gauge, laser distrometer) to reveal the described mechanisms from the canopy through different vegetation layers to the ground. First results of splash cup measurements (revised after Ellison 1947) show that sand loss under vegetation is 2.5 times higher than in open field despite the fact that only 60 percent of open field rainfall reaches the ground. The results also indicate that sand loss is a function of the age of the specific forest stand and the variability of sand loss under different species with respect to space and time. These and future results will help managing afforestation projects in giving implications which of the species (resp. species compositions) may reduce most effectively potential splash erosion. References: Brandt, C. J. (1989): The size distribution of throughfall drops under vegetation canopies. Catena 16, p. 507-524. Calder, I. R. (2001): Canopy processes: implications for transpiration, interception and splash induced erosion, ultimately for forest management and water resources. Plant Ecology 153, p. 203-214. Ellison, W. D. (1947): Soil Erosion Studies - Part II. Soil Detachment Hazard by Raindrop Splash. Agricultural Engineering 28, p. 197-201. Foot, K.; Morgan, R. P. C. (2005): The role of leaf inclination, leaf orientation and plant canopy architecture in soil particle detachment by raindrops. Earth Surface Processes and Landforms 30, p. 1509-1520. Nanko, K.; Hotta, N. & Suzuki, M. (2006): Evaluating the influence of canopy species and meteorological factors on throughfall drop size distribution. Journal of Hydrology 329, p. 422-431. Vis, M. (1986): Interception, drop size distributions and rainfall kinetic energy in four colombian forest ecosystems. Earth Surface Processes and Landforms 11, p. 591-603.

Geißler, C.; Kühn, P.; Scholten, T.

2009-04-01

381

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.

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

2009-01-01

382

Disappearing Rocks: How Erosion Creates Ventifacts  

NSDL National Science Digital Library

In this activity, students will learn what causes the various types of erosion that have formed our Earth as it is today and how different surfaces erode differently. The students will: predict the outcomes of erosion on different materials; describe ways of preventing erosion; and recognize erosion and predict what type of erosion caused it. The elaboration section of the activity explores erosion in Antarctica.

Elliott, Elissa

383

Anti-inflammatory effects of rebamipide according to Helicobacter pylori status in patients with chronic erosive gastritis: a randomized sucralfate-controlled multicenter trial in China-STARS study.  

PubMed

The aim of the study was to investigate the effects of rebamipide on symptom, histology, endogenous prostaglandin, and mucosal oxygen free radicals in chronic erosive gastritis (CEG) patients by using sucralfate as a control. The trial also examined whether Helicobacter pylori infection would affect rebamipide-induced protection. A total of 453 endoscopy-confirmed CEG patients from 11 hospitals in China were enrolled in the study. They randomly received either rebamipide (100 mg t.i.d) or sucralfate (1.0 t.i.d) for 8 weeks with a ratio of 3:1. Per-protocol analysis (n = 415) showed the accumulated symptom score in the rebamipide group dropped from 5.54 +/- 0.97 to 0.80 +/- 0.47 after 8 weeks (P < 0.001 versus control). The endoscopic inflammation score in rebamipide group also decreased from 2.65 +/- 0.09 to 0.60 +/- 0.10, which showed better effects than sucralfate. It was shown a significant improvement (P < 0.01) in prostaglandin E2 (PGE(2)) contents in rebamipide-treated subjects mucosa (225.4 +/- 18.3 pg/g versus 266.7 +/- 14.7 pg/g) compared with that in sucralfate group after 8 weeks of treatment. Malondialdehyde (MDA) contents were significantly depressed both in the trial and control group. When Helicobacter pylori infection was considered, no statistically difference was found in the effect of rebamipide on either symptom or inflammation scores. In conclusion, Rebamipide demonstrated a stronger suppressive effect on the mucosal inflammation in chronic erosive gastritis than sucralfate. The gastroprotection induced by rebamipide is not influenced by H. pylori infection, which indicates its usage in the treatment of H. pylori-associated CEG. PMID:18288617

Du, Yiqi; Li, Zhaoshen; Zhan, Xianbao; Chen, Jie; Gao, Jun; Gong, Yanfang; Ren, Jianlin; He, Liping; Zhang, Zhijian; Guo, Xiaozhong; Wu, Jianshen; Tian, Zibin; Shi, Ruihua; Jiang, Bo; Fang, Dianchun; Li, Youming

2008-02-21

384

Rainfall erosion model  

NASA Astrophysics Data System (ADS)

A model describing rainfall erosion over the course of a long time period is proposed. The model includes: (1) a new equation of detachment of soil particles by water flows based on the Mirtskhulava equation; (2) a new equation for the transport capacity of the flow based on a modified Bagnold equation, which is used in the AGNPS model; (3) modified SCS runoff equation; (4) probability distributions for rainfall. The proposed equations agree satisfactorily with the data of on-site observations of the Moldova and Nizhnedevitsk water-balance stations. The Monte Carlo method is used for numerical modeling of random variables. The results of modeling agree satisfactorily with empirical equations developed for conditions in Russia and the United States. The effect of climatic conditions on the dependence of longtime average annual soil loss on various factors is analyzed. Minimum information is used for assigning the initial data.

Sukhanovskii, Yu. P.

2010-09-01

385

Hoxb1 Controls Anteroposterior Identity of Vestibular Projection Neurons  

PubMed Central

The vestibular nuclear complex (VNC) consists of a collection of sensory relay nuclei that integrates and relays information essential for coordination of eye movements, balance, and posture. Spanning the majority of the hindbrain alar plate, the rhombomere (r) origin and projection pattern of the VNC have been characterized in descriptive works using neuroanatomical tracing. However, neither the molecular identity nor developmental regulation of individual nucleus of the VNC has been determined. To begin to address this issue, we found that Hoxb1 is required for the anterior-posterior (AP) identity of precursors that contribute to the lateral vestibular nucleus (LVN). Using a gene-targeted Hoxb1-GFP reporter in the mouse, we show that the LVN precursors originate exclusively from r4 and project to the spinal cord in the stereotypic pattern of the lateral vestibulospinal tract that provides input into spinal motoneurons driving extensor muscles of the limb. The r4-derived LVN precursors express the transcription factors Phox2a and Lbx1, and the glutamatergic marker Vglut2, which together defines them as dB2 neurons. Loss of Hoxb1 function does not alter the glutamatergic phenotype of dB2 neurons, but alters their stereotyped spinal cord projection. Moreover, at the expense of Phox2a, the glutamatergic determinants Lmx1b and Tlx3 were ectopically expressed by dB2 neurons. Our study suggests that the Hox genes determine the AP identity and diversity of vestibular precursors, including their output target, by coordinating the expression of neurotransmitter determinant and target selection properties along the AP axis.

Chen, Yiju; Takano-Maruyama, Masumi; Fritzsch, Bernd; Gaufo, Gary O.

2012-01-01

386

The Use of Fuzzy Numbers in Practical Project Planning and Control  

Microsoft Academic Search

\\u000a The paper proposes how to use fuzzy numbers in project planning and control in such a way that it would have a chance to be\\u000a used in practice. The method is destined for all the projects, but especially for those where in the initial phase the knowledge\\u000a about the project is very incomplete and is made stepwise more precise during

Dorota Kuchta

387

Tropical volcanic islands: best first cycle erosion laboratories.  

NASA Astrophysics Data System (ADS)

Lesser Antilles islands are located in a tropical climate with high temperatures (24 to 28 ° C), high precipitation (can reach 12 m/yr), very dense vegetation, sharp relief with a NS gradient of age. Antilles rivers have a torrential hydrologic regime with extreme erosion conditions. Chemical weathering rates are among highest world values 140-200 t/km2/yr on surface and 2 to 5 time higher when subsurface water circulations are taken account (Rad et al., 2007). Timescales and physical rates of erosion are calculated from U-Th isotopic compositions. Our results, with 3 different methods (all based on mass budgets between the river bedrock and its erosion products) show a good agreement for physical erosion rates with a maximum value of 2500 t/km2/yr. We show that solid loads of these volcanic rivers are dominated by sand, which represent more than 80% of the soil profile. Erosion rates are directly correlated to the age of basins. Indeed, among all parameters (climat, runoff, slopes, vegetation...) the age basins is a key control parameter. The younger the basin is the higher the weathering rate is. This correlation asserts that younger volcanic rocks are more easily weathered than old ones: young fresh material is easily mobilized by erosion, while for older rocks with thick soil covers, chemical and physical erosion rates are much lower, they reach a threshold with low chemical and physical rates once soils are constituted. It seems that rivers draining young lava flows are also the ones, which are not at steady state with the lowest mechanical denudation rates. Erosion processes in Lesser Antilles are typical of a first cycle erosion with simple relationship between rates, timescale of erosion and basins ages. It appears that first stage of erosion are characterized by high chemical denudation rates and low physical denudation rates, the erosion products are then close to the bedrock. It is then followed in a second stage by constant chemical weathering rates with higher mechanical denudation rates. \\small Setareh Denise Rad, Claude Jean Allegre and Pascale Louvat, 2007, Hidden erosion on volcanic islands, Earth and Planetary Science Letters. In Press.

Rad, S.; Rive, K.; Gaillardet, J.; Allegre, C. J.

2007-12-01

388

Control Systems for Information Systems Development Projects (Part I)  

ERIC Educational Resources Information Center

|Discusses control of management information systems and finds a similarity in management of research and development activity. Part II will appear in AEDS Journal, Volume 4, number 2, December 1970. (JF)|

Dickson, Gary W.

1970-01-01

389

Technical Assistance Project for the Minnesota Pollution Control Agency.  

National Technical Information Service (NTIS)

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 L...

L. Vimmerstedt

2006-01-01

390

SOLERAS Solar-Energy Controlled-Environment Agriculture Project.  

National Technical Information Service (NTIS)

Three commercial-size (5-ha), solar-powered, controlled-environment agriculture systems for hot, dry climates are described. The systems use brackish well water for cooling. The well water is desalinated for irrigation using reverse osmosis. Produce outpu...

W. Luft J. Froechtenigt A. Falatah

1982-01-01

391

Microprocessor control of offshore enhanced oil recovery project  

SciTech Connect

The proportioning of natural gas liquids among 6 injection wells is described and controlling the corresponding gas necessary to maintain a specified liquid to gas ratio for each individual well is discussed. To accomplish this proportioning, the system selects a master well, controls both liquid and gas header pressure, and calculates corrected flow rates. In addition to these functions the microprocessor also prints on demand both instantaneous flow rates and cumulative volume injected for each well.

Durham, M.; Lechler, R.; Long, W.

1983-01-01

392

Design of decentralized projective controls for disturbance rejection  

Microsoft Academic Search

A two-stage design problem is formulated to achieve disturbance rejection using low-order decentralized controllers. Using the H?-optimal state feedback solutions as the reference, the authors parameterize all decentralized controllers of a given order retaining the dominant poles in the closed-loop system. Using a Frobenius-Hankel norm-minimization approach, they determine the free parameters in the parameterization that can be used to place

J. V. Medanic; W. R. Perkins; Z. Uskokovic; F. A. Latuda

1989-01-01

393

Sour sweets: a new type of erosive challenge?  

Microsoft Academic Search

Objective To assess the erosive potential of a number of commercially available sour sweets in the laboratory.Methods The erosive potential was assessed by measuring the pH, neutralisable acidity and ability to erode permanent and deciduous enamel. These parameters were compared to those of an orange juice positive control.Results The pH of the sour sweets ranged from 2.30-3.14 with their neutralisable

R. Davies; L. Hunter; T. Loyn; J. Rees

2007-01-01

394

Arkansas Basin Chloride Control Project: A Critical Evaluation of Regional Effects.  

National Technical Information Service (NTIS)

The purpose is to assess the regional economic benefits and costs of the Arkansas River Basin Chloride Control Project, a project designed to alleviate a major saline pollution problem. The methods for the corps of engineers' study give estimates of natio...

K. W. Olson A. B. Holmes

1978-01-01

395

Report on the Archaeological Survey of the Mankato Flood Control Project.  

National Technical Information Service (NTIS)

The purpose of this project is to identify archaeological resources present in the areas to be altered during or as a result of the Army Corps of Engineers Flood Control Project in the Mankato area, and to evaluate the historic and prehistoric importance ...

R. A. Strachan K. A. Roetzel

1975-01-01

396

Computer based Intelligence, Design, Choice, Implementation, and Control of Intangible Investments Projects  

Microsoft Academic Search

In this paper we show by means of an actual project how a computer based system can support whole process of management of the intangible investments - intelligence, design, choice, implementation, and control - in an efficient manner. For the planning of intangible investment projects we have developed a set of tools where several decision aids are integrated to support

Hannu Kivijärvi; Markku Tuominen

1999-01-01

397

Project-based teaching unit using energetic macroscopic representation to design drive controllers  

Microsoft Academic Search

This paper describes an example of a student's simulation project based on a steer-by-wire system. The approach followed during this project relies on the Energetic Macroscopic Representation to help students to organize their simulation worksheet, and to deduce by inversion the control laws.

F. Giraud; A.-L. Alle?gre; A. Bouscayrol; K. Chen; B. Lemaire-Semail; W. Lhomme

2010-01-01

398

Report on the Archaeological Survey of the Rochester-Zumbro River Flood Control Project.  

National Technical Information Service (NTIS)

This is a report of an archaeological testing and survey project covering the proposed flood control construction in and around the city of Rochester Minnesota. It is preliminary in nature, involving surface reconnaissance and testing to be followed by mo...

R. A. Strachan

1975-01-01

399

Environmental Control Plan for Groundwater/Vadose Zone Technology Development Projects.  

National Technical Information Service (NTIS)

This environmental control plan (ECP) is applicable to field activities to groundwater/vadose zone technology development projects. These activities include excavation, soil sampling, borehole geophysical surveying, dye application, tracer injection, and ...

M. N. Jarayssi

2001-01-01

400

Summary of Phase 2 Implementation Plans: Diabetes Control Demonstration Project States.  

National Technical Information Service (NTIS)

The approach to the public health control of diabetes varied among the project states. Each state tailored its interventions to accomodate its unique mix of needs and resources. Important considerations included demonstration value, resource requirements,...

1979-01-01

401

Methodology for Evaluation of Feasibility: Multijurisdictional Urban Drainage and Flood Control Projects.  

National Technical Information Service (NTIS)

A methodology enabling engineers to evaluate the feasibility of urban drainage and flood control (UDFC) projects is reported. Currently, interest is increasing in nonstructural solutions to flooding. In addition to providing better land use plans and floo...

1977-01-01

402

THE WEPP MODEL FOR RUNOFF AND EROSION PREDICTION UNDER SPRINKLER IRRIGATION  

Microsoft Academic Search

Potential runoff and erosion is a serious problem for some types of sprinkler irrigation systems, particularly traveling laterals and center pivots on medium- to heavy-textured soils operating on sloping land. Prediction of when runoff might occur is part of the system design process. The USDA-ARS Water Erosion Prediction Project (WEPP) model was tested with 3 years of field data under

D. C. Kincaid

403

Effects of cropping and tillage systems on soil erosion under climate change in Oklahoma  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soil erosion under future climate change is very likely to increase due to projected increases in frequency and magnitude of heavy storms. The objective of this study is to quantify the effects of common cropping and tillage systems on soil erosion and surface runoff during 2010-2039 in central Okl...

404

Cropping and tillage systems effects on soil erosion under climate change in Oklahoma  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soil erosion under future climate change is very likely to increase due to projected increases in frequency and magnitude of heavy storms. The objective of this study is to quantify the effects of common cropping and tillage systems on soil erosion and surface runoff during 2010-2039 in central Okl...

405

Preliminary investigation of the use of air injection to mitigate cavitation erosion  

Microsoft Academic Search

This project was initiated as part of a new research and development focus to improve hydropower generation. One aspect of the problem is severe cavitation erosion which is experienced when hydroturbines are operated at best power or in spinning reserve. Air injection has been used successfully to minimize or eliminate cavitation erosion in other applications. Thus, an investigation was initiated

R. E. A. Arndt; C. R. Ellis; S. Paul

1995-01-01

406

Glacial Erosion by the Laurentide Ice Sheet and Its Relationship to Ice, Topographic and Bedrock Conditions.  

National Technical Information Service (NTIS)

The aim of this project was to map and analyse landscapes of glacial erosion associated with the Laurentide ice sheet and to relate them to the main variables affecting glacial erosion: basal thermal regime of the ice sheet, the topography and geology of ...

D. E. Sugden

1976-01-01

407

Pilot project to estimate the centralized volt\\/VAr control effectiveness  

Microsoft Academic Search

This paper describes a volt\\/VAr control (VVC) project in which a centralized network-model based VVC was put in place to control a 13.8 kV distribution subsystem. The goal of the project is to estimate the effectiveness of VVC based on different objective functions, including an objective function for future market economy (revenue maximization). The technical issues which are critical to

I. Roytelman; B. K. Wee; R. L. Lugtu; T. M. Kulas; T. Brossart

1997-01-01

408

Pilot project to estimate the centralized volt\\/VAr control effectiveness  

Microsoft Academic Search

This paper describes a volt\\/VAr control (VVC) project in which a centralized network-model based VVC was put in place to control a 13.8 kV distribution subsystem. The goal of the project is to estimate the effectiveness of VVC based on different objective functions, including an objective function for future market economy (revenue maximization). The technical issues which are critical to

I. Roytelman; B. K. Wee; R. L. Lugtu; T. M. Kulas; T. Brossart

1998-01-01

409

Athens automation and control experiment project review meeting, Knoxville, Tennessee, December 3-5, 1985  

SciTech Connect

The AACE is an electric power distribution automation project involving research and development of both hardware and software. Equipment for the project is being installed on the electric distribution system in Athens, Tennessee. Purposes of the AACE are to develop and test load control, volt/var control, and system reconfiguration capabilities on an electric distribution system and to transfer what is learned to the electric utility industry. Expected benefits include deferral of costly power generation plants and increased electric service reliability.

Braithwait, S.D.; Broadaway, E.R.; Fortson, N.D.; Gellings, C.W.; Hu, P.S.; Lawler, J.S.; Markel, L.C.; McKinley, K.F.; Monteen, L.D.; Newton, B.K.

1986-08-01

410

Sludge Treatment Project KOP Conceptual Design Control Decision Report.  

National Technical Information Service (NTIS)

This control decision addresses the Knock-Out Pot (KOP) Disposition KOP Processing System (KPS) conceptual design. The KPS functions to (1) retrieve KOP material from canisters, (2) remove particles less than 600 (micro)m in size and low density materials...

C. A. Carro

2010-01-01

411

INDUSTRIAL POLLUTION CONTROL DIVISION REPORTS AND PROJECT ABSTRACTS  

EPA Science Inventory

This report contains bibliographic information and abstracts for all reports issued by EPA and its predecessor agencies on the development and demonstration of technology to control pollution from those industries which are assigned to IERL-Cincinnati. The major industries includ...

412

SLUDGE TREATMENT PROJECT KOP CONCEPTUAL DESIGN CONTROL DECISION REPORT  

Microsoft Academic Search

This control decision addresses the Knock-Out Pot (KOP) Disposition KOP Processing System (KPS) conceptual design. The KPS functions to (1) retrieve KOP material from canisters, (2) remove particles less than 600 m in size and low density materials from the KOP material, (3) load the KOP material into Multi-Canister Overpack (MCO) baskets, and (4) stage the MCO baskets for subsequent

CARRO CA

2010-01-01

413

Gastroesophageal Reflux Disease and Tooth Erosion  

PubMed Central

The increasing prevalence of gastroesophageal reflux disease (GERD) in children and adults, and of “silent refluxers” in particular, increases the responsibility of dentists to be alert to this potentially severe condition when observing unexplained instances of tooth erosion. Although gastroesophageal reflux is a normal physiologic occurrence, excessive gastric and duodenal regurgitation combined with a decrease in normal protective mechanisms, including an adequate production of saliva, may result in many esophageal and extraesophageal adverse conditions. Sleep-related GERD is particularly insidious as the supine position enhances the proximal migration of gastric contents, and normal saliva production is much reduced. Gastric acid will displace saliva easily from tooth surfaces, and proteolytic pepsin will remove protective dental pellicle. Though increasing evidence of associations between GERD and tooth erosion has been shown in both animal and human studies, relatively few clinical studies have been carried out under controlled trial conditions. Suspicion of an endogenous source of acid being associated with observed tooth erosion requires medical referral and management of the patient as the primary method for its prevention and control.

Ranjitkar, Sarbin; Kaidonis, John A.; Smales, Roger J.

2012-01-01

414

Savannah River Site 1991 Road Erosion Inventory.  

SciTech Connect

Final Report. USDA Forest Service, Savannah River, Aiken, SC. 28 pp. Abstract - This paper explains the rationale and results of a 1991 road erosion inventory conducted by members of the USDA Forest Service – Savannah River (FS-SR) and USDA Natural Resources Conservation Service (NRCS). The inventory provided information for the Department of Energy - Savannah River (DOE-SR) to justify the need for developing an erosion and sediment control program with appropriate funding, personnel, and equipment. Federally managed since the early 1950’s, the SRS is located on 198,344 acres (80,301 hectares) in the South Carolina counties of Aiken, Barnwell, and Allendale. Located along the eastern border of the Savannah River, the SRS is located within the Upper and Lower Coastal Plains of South Carolina.

Jones, Cliff.

2007-06-22

415

Topographic and radiographic profile assessment of dental erosion. Part III: Effect of green and black tea on human dentition.  

PubMed

This study compared green and black tea to soda and orange juice in terms of their erosive effect on the human dentition. Vinegar and water were used as active and passive control fluids. An accelerated in vitro test was used to monitor how short- and long-term exposure to these fluids affected the topography and morphology of the coronal segments of the human dentition. This 20-week test was conducted under controlled conditions, independent of the influencing factors of the oral environment. The erosive effects of these fluids were categorized generally into three groups: highly erosive (vinegar), moderately erosive (soda and orange juice), and minimally erosive (black and green tea). The erosive effect of tea was similar to that of water, which has no erosion potential. Given the systemic and dental benefits of tea and the low potential for erosion, green and black tea should be highly encouraged for daily beverage consumption. PMID:18683403

Bassiouny, Mohamed A; Kuroda, Shuntaro; Yang, Jie

416

Soil erosion in developing countries: A politicoeconomic explanation  

NASA Astrophysics Data System (ADS)

Soil erosion is accelerating in developing countries of Asia, Africa, and Latin America. It has threatened the livelihood of millions of peasants, for agriculture is their economic mainstay. A probe into the forces causing erosion reveals that the elite’s resolve to accumulate ever more wealth and to maintain, consolidate, or expand their sociopolitical power and the necessity of the poor to fulfill their requirements of food, fuelwood, and fodder are the two major factors accelerating soil erosion. Unless the vast masses of poor people are integrated into the national mainstream through the implementation of equitable and redistributive development policies, it is impossible to control the accelerating rate of soil erosion and thus to achieve the objective of sustainable development.

Thapa, Gopal B.; Weber, Karl E.

1991-07-01

417

Solid-particle erosion of aluminum/particulate ceramic composites  

SciTech Connect

Impact erosion of 2014 aluminum, 2014 aluminum + 20 vol % particulate silicon carbide, and 2014 aluminum + 20 vol % particulate aluminum oxide has been studied at room temperature. The alloys were tested in the as-received and heat-treated conditions. Experiments were conducted with aluminum oxide abrasive in vacuum in a slinger-type apparatus over a range of abrasive size, velocity, and angle of impact. Erosion rates were influenced by reinforcement and heat treatment. Reduced ductility, both overall and local, attributed to reinforcement or heat treatment, caused, under most conditions, more rapid erosion of the composites. The data suggest that erosion rate can be minimized by proper microstructural control, involving reducing reinforcement segregation and the amount of intermetallic compounds. 37 refs., 7 figs.

Goretta, K.C.; Wu, W.; Routbort, J.L. (Argonne National Lab., IL (USA)); Rohatgi, P.K. (Wisconsin Univ., Milwaukee, WI (USA))

1990-06-01

418

3D seismic characterization of the Norwegian Channel Ice Stream - bedrock controls on ice streaming behaviour and spatio-temporal evolution of erosion and infill of a major cross-shelf trough through multiple glaciations  

NASA Astrophysics Data System (ADS)

The imprint of the Pleistocene glaciations in the North Sea Basin is known from various localities scattered across the North Sea Basin and to a large extent relies on widely spaced cored boreholes linked with 2D seismic profiles. Recent studies have demonstrated that a step change in levels of detail can be achieved when using 3D seismic data to image the glaciogenic sequences. However, to date only a relatively small part of the North Sea has been investigated with these data sets. Because of the long history of hydrocarbon exploration, the North Sea is now covered from coast to coast with high-quality 3D seismic data which allow the glacial succession to be examined in great spatio-temporal detail. This project used a regionally merged (c. 150 km by 150 km, 50 m bin spacing) 'mega survey' 3D seismic dataset to provide, for the first time, a 3D seismic geomorphological characterization of the Norwegian Channel Ice Stream, which records glaciations of the North Sea since at least 1.1 Ma. The project first linked the cored Troll borehole with the 3D seismic dataset, providing age and lithological calibrations of the ice stream base and key glacial surfaces within the fill. The interpretation was then extended to the greater survey extent. The basal ice stream footprint reveals a correlation between km-wide and tens of km long positive landform and dominantly sandy deposits in the substrate. The overall architecture of the infill reveals a progressive filling up of the eastern (proximal) part of the cross shelf trough whilst erosion dominated on the western (distal) flank. This evolution matches the evolution of the trough mouth fan situated on the Atlantic margin which shows a progressive westward migration of depocentres through the Pleistocene. On a smaller scale, the 3D seismic data display the interplay between fjord-supplied ice and the main ice stream conduit. Moreover the analysis suggests the occurrence of numerous grounded as well as floating glacial episodes, separated by marine sedimentation. Some of the marine inter-glacial units show evidence for tidal reworking and tidal cycles are depicted semi-quantitatively by sinuous iceberg scours. Importantly, the cross shelf trough provides a near complete record of glacial and interglacial sedimentation in a proximal setting which is available nowhere else, and yet there is only a single cored borehole within this archive. Clearly only full 3D coverage can ensure that future boreholes target the most complete sections including the oldest part of the ice stream fill which was not sampled in Troll, suggesting perhaps an even older origin of the basal erosion surface.

Grant, J.; Huuse, M.

2010-12-01

419

Application for Underground Injection Control Permit for the PUNA Geothermal Venture Project  

SciTech Connect

Puna Geothermal Venture (PGV) plans to construct and operate the 25 MW Puna Geothermal Venture Project in the Puna District of the Island of Hawaii. The project will drill geothermal wells within a dedicated 500-acre project area, use the produced geothermal fluid to generate electricity for sale to the Hawaii Electric Light Company for use on the Island of Hawaii, and inject all the produced geothermal fluids back into the geothermal reservoir. Since the project will use injection wells, it will require an Underground Injection Control (UIC) permit from the Drinking Water Section of the State of Hawaii Department of Health. The PGV Project is consistent with the State and County of Hawaii's stated objectives of providing energy self-sufficiency and diversifying Hawaii's economic base. The project will develop a new alternate energy source as well as provide additional information about the nature of the geothermal resource.

None

1989-06-01

420

Mechanics of Interrill Erosion with Wind-Driven Rain (WDR)  

Technology Transfer Automated Retrieval System (TEKTRAN)

This article provides an evaluation analysis for the performance of the interrill component of the Water Erosion Prediction Project (WEPP) model for Wind-Driven Rain (WDR) events. The interrill delivery rates (Di) were collected in the wind tunnel rainfall simulator facility of the International Cen...

421

Managing erosion-induced problems in NW Mediterranean urban beaches  

Microsoft Academic Search

The applicability of recommendations of the Eurosion project to define a policy to manage coastal erosion has been tested at the “beach” scale in the Mediterranean coast. Thus, a favourable sediment status has been defined for these beaches taking into account their main functions: recreation and protection. Because they act at two different seasons, this status needs to be seasonally

José A. Jiménez; Vicenç Gracia; Herminia I. Valdemoro; E. Tonatiuh Mendoza; Agustín Sánchez-Arcilla

422

Prefabricated erosion prevention wall  

US Patent & Trademark Office Database

Disclosed is a device for protecting against beach erosion. The device has a supporting platform that rests on the sea bottom, and an upwardly curved surface extending from the platform. In one embodiment the concave side faces incoming waves and the convex side faces the seabed. The upwardly curved surface deflects incoming waves upwardly, thus breaking the major portion of their force before they impact upon the beach. The platform and curved surface together form a wall like a barrier that blocks the path of sand washed from the beach, so as to trap the sand for reclaimation before it migrates so far out to seat to be lost irretrievably. The platform can have extending from it anchoring feet to anchor the device in the seabed. In another embodiment the disposition of these convex and concave surfaces is reversed. Incoming waves are broken to a lesser extent, enabling these waves to aid beach buildup by washing submerged sand blocked by the device back onto the beach, much like the known, natural, process by which gentle breaking waves wash up sand trapped in sea grasses.

Rauch; Hans G. (West Palm Beach, FL)

1989-04-04

423

Soleras solar energy controlled-environment agriculture project  

SciTech Connect

Three commercial-size (5-ha), solar-powered, controlled-environment agriculture systems for hot, dry climates are described. The systems use brackish well water for cooling. The well water is desalinated for irrigation using reverse osmosis. Produce output ranges from 44 to 78 kg/m/sup 2/. yr with an overall water consumption of 8 to 139 L/kg produce and electric energy consumption of 111 to 790 Wh/kg produce. The levelized cost ranges from $1.14 to $8.07 per kg of produce.

Luft, W.; Falatah, A.; Froechtenigt, J.

1982-08-01

424

SOLERAS solar-energy controlled-environment agriculture project  

SciTech Connect

Three commercial-size (5-ha), solar-powered, controlled-environment agriculture systems for hot, dry climates are described. The systems use brackish well water for cooling. The well water is desalinated for irrigation using reverse osmosis. Produce output ranges from 44 to 78 kg/m/sup 2/.yr with an overall water consumption of 8 to 139 L/kg produce and electric energy consumption of 111 to 790 Wh/kg produce. The levelized cost ranges from $1.14 to $8.07 per kg of produce.

Luft, W.; Froechtenigt, J.; Falatah, A.

1982-05-01

425

Thermal Erosion of Electrical Insulating Materials  

Microsoft Academic Search

The erosion of synthetic insulating materials by surface discharges constitutes an important problem in the application of these materials for high-voltage outdoor applications. A method of erosion testing is described that simulates the heat flux from surface discharges by radiant energy from a thermal imaging source. This permits accurate measurement of erosion. A theory of erosion is developed that is

MALCOLM J. BILLINGS; Leonard Warren; Robert Wilkings

1971-01-01

426

Soil Erosion and Agricultural Sustainability  

NASA Astrophysics Data System (ADS)

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 up to several orders of magnitude, similar global distributions of soil production and geological erosion rates suggest an approximate balance. Net soil erosion rates in conventionally plowed fields on the order of 1 mm/yr can erode typical hillslope soil profiles over centuries to millennia, time-scales comparable to the longevity of major civilizations. Well-documented episodes of soil loss associated with agricultural activities date back to the introduction of erosive agricultural methods in regions around the world, and stratigraphic records of accelerated anthropogenic soil erosion have been recovered from lake, fluvial, and colluvial stratigraphy, as well as truncation of soil stratigraphy (such as truncated A horizons). A broad convergence in the results from studies based on various approaches employed to study ancient soil loss and rates of downstream sedimentation implies that widespread soil loss has accompanied human agricultural intensification in examples drawn from around the world. While a broad range of factors, including climate variability and society-specific social and economic contexts — such as wars or colonial relationships — all naturally influence the longevity of human societies, the ongoing loss of topsoil inferred from studies of soil erosion rates in conventional agricultural systems has obvious long-term implications for agricultural sustainability. Consequently, modern agriculture — and therefore global society — faces a fundamental question over the upcoming centuries. Can an agricultural system capable of feeding a growing population safeguard both soil fertility and the soil itself? Although the experiences of past societies provide ample historical basis for concern about the long-term prospects for soil conservation, data compiled from recent studies indicate that no-till farming could reduce erosion to levels close to soil production rates. Consequently, agricultural production need not necessarily come at the expense of either soil fertility or the soil itself, even if recent proposals to rely on conventionally grown corn for biofuels exemplify how short-term social and economic trade-offs can de-prioritize soil conservation. Like the issues of climate change and loss of biodiversity, the ongoing global degradation and loss of soil presents a fundamental social challenge in which the slow pace of environmental change counter-intuitively makes solutions all the more difficult to adopt.

Montgomery, D. R.

2009-04-01

427

Cavitation erosion of aluminium alloys  

Microsoft Academic Search

Cast aluminium-silicon, cast aluminium-zinc and mechanically alloyed aluminium alloys were eroded in distilled water using a 20 kHz ultrasonic vibratory device. The erosion was measured by weight loss, and the damaged surface was examined using metallographic and profilometric techniques. The maximum differences in the incubation period, in the linear erosion rate and in the mass loss after a 10 h

W. J. Tomlinson; S. J. Matthews

1994-01-01

428

Combating dephasing decoherence by periodically performing tracking control and projective measurement  

SciTech Connect

We propose a scheme to overcome phase damping decoherence by periodically performing open loop tracking control and projective measurement. Although it is impossible to stabilize a qubit subject to Markovian dynamics only by open loop coherent control, one can attain a 'softened' control goal with the help of periodical projective measurement. The 'softened' control objective in our scheme is to keep the state of the controlled qubit to stay near a reference pure state with a high probability for a sufficiently long time. Two suboptimal control problems are given in the sense of trace distance and fidelity, respectively, and they are eventually reduced to the design of a period T. In our scheme, one can choose the period T as long as possible if the 'softened' control goal is attained. This is in contrast to the observation that quantum Zeno effect takes place only if measurements are performed in a very frequent manner, i.e., the period T must be extremely small.

Zhang Ming [College of Mechatronics and Automation, National University of Defense Technology, Changsha, 410073 (China); Key Laboratory of Systems and Control, Chinese Academy of Sciences, Beijing, 100080 (China); Dai Hongyi [College of Science, National University of Defense Technology, Changsha, 410073 (China); Xi Zairong [Key Laboratory of Systems and Control, Chinese Academy of Sciences, Beijing, 100080 (China); Xie Hongwei; Hu Dewen [College of Mechatronics and Automation, National University of Defense Technology, Changsha, 410073 (China)

2007-10-15

429

SIDASS project  

Microsoft Academic Search

The SIDASS project “A spatially distributed simulation model predicting the dynamics of agro-physical soil state within Eastern and Western Europe countries for the selection of management practices to prevent soil erosion based on sustainable soil–water interactions” required a method for estimating the dates (or soil water conditions) under which soil tillage operations could be performed. For this purpose, methods were

A. R. Dexter; E. A. Czy?; M. Birkás; E. Diaz-Pereira; E. Dumitru; R. Enache; H. Fleige; R. Horn; K. Rajkaj; D. de la Rosa; C. Simota

2005-01-01

430

Projections for the future development of international drug control policies.  

PubMed

With the adoption of the Declaration and the Comprehensive Multidisciplinary Outline of Future Activities in Drug Abuse Control by the International Conference on Drug Abuse and Illicit Trafficking (ICDAIT) in 1987 and the formulation in 1988 of the United Nations Convention against Illicit Traffic in Narcotic Drugs and Psychotropic Substances, the United Nations has made significant contributions to international drug control policy, in line with its responsibilities under article 55 of the Charter. Governments are acting, separately and through regional and other collective organizations, to adapt these policies to their own particular needs and to make the legislative changes needed to enable ratification of the new Convention. Simultaneously, the Commission on Narcotic Drugs continues to carry out its policy-making function by identifying areas of concern on which consensus can be achieved as well as appropriate techniques for achieving effective international co-operation as foreseen in the Charter of the United Nations. The present article draws attention to recent developments pointing to possible areas of policy formulation. These include enhanced cooperation of law enforcement agencies with overlapping jurisdictions; judicial methodology and inter-system co-operation to follow on from seizures from the illicit traffic and detention of suspects to consideration of treatment methodology; and adaptation of demand reduction techniques to target groups beyond the reach of formal educational institutions. The trend towards horizontal integration of trafficking networks is examined in the context of indications linking illicit traffic in psychotropic substances to the production and trade of chemical weapons, such as poison gas, and to the cultivation of new markets in response to the saturation of certain North American markets for specific illicit drugs. PMID:2095934

Oppenheimer, T M

1990-01-01

431

Controlled landfill project: Mountain View, California. Annual report, January-December 1982  

Microsoft Academic Search

This project studied the effects of leachate recirculation and added water, buffer and sludge on enhancing the generation and improving the recovery of landfill gas. It evaluated the various techniques by providing individual control cells for the demonstration of enhancement methods. The study also documents landfill gas productions from a controlled volume at field scale. Results from this study provide

T. A. Bonham; R. E. Van Heuit; W. M. Carroll; M. Donch

1984-01-01

432

Towards a Case-Based Reasoning Framework for Construction Project Planning and Control  

Microsoft Academic Search

The work presented in this paper is aimed at investigating the extent to which both 'user and system decision-making' in construction project planning and control can be captured and stored for future use. This paper presents work being conducted to establish a framework for the application of CBR to construction planning and control. Due to the high variability in the

R. Howes

433

Multi-Canister overpack pressurization monitoring and control methodology for the spent nuclear fuel project  

SciTech Connect

A control methodology is developed and monitoring alternatives evaluated for controlling pressurization in a Multi- Canister Overpack for the Hanford Spent Nuclear Fuel Project. Monitoring alternative evaluations include concept description, identification of uncertainties, and identification of experimental work required for implementation. A monitoring alternative is recommended and implementation requirements, risks and start up testing associated with the recommendation are discussed.

Pajunen, A.L., Westinghouse Hanford

1996-07-19

434

Evaluation of the USDA Northeast Area-wide Tick Control Project by Meta-analysis  

Technology Transfer Automated Retrieval System (TEKTRAN)

As part of the Northeast Area-wide Tick Control Project (NEATCP), meta-analyses were performed using pooled data on the extent of tick-vector control achieved through seven concurrent studies, conducted within five states, using USDA ‘4-Poster’ devices to deliver targeted-acaricide to white-tailed d...

435

AC 2009-1335: A MICROPROCESSOR-BASED CONTROL SYSTEM PROJECT FOR AN INTEGRATED FRESHMAN CURRICULUM  

Microsoft Academic Search

Abstract A project has been developed and implemented,in which the temperature and salinity are controlled in a small volume,of water which is circulated using a small pump. A conductivity sensor measures salinity, and a Resistance Temperature Device (RTD) monitors temperature, providing data to a BASIC Stamp controller. Two relays are used to operate solenoid valves that release either fresh or

Michael Swanbom

2009-01-01

436

The United States Department of Agriculture northeast area-wide tick control project - history and protocol  

Technology Transfer Automated Retrieval System (TEKTRAN)

This manuscript summarizes the history of development of the ARS-patented ‘4-Poster’ Deer Treatment Bait Station technology for the control of ticks feeding on white-tailed deer and other wild ungulates, provides the rationale for its use in the USDA Northeast Area-wide Tick Control Project, and des...

437

RUNOFF, EROSION AND NUTRIENT LOSSES FROM COMPOST AND MULCH BLANKETS UNDER SIMULATED RAINFALL 1592  

Technology Transfer Automated Retrieval System (TEKTRAN)

Control of soil erosion and associated nonpoint source pollution to improving water quality. The use of compost or mulch blankets as a soil cover canhelp control soil erosion and p[rovide sustainable alternatives to disposal for many biomass resources. The objective of this study was to investigae...

438

Erosion of heat exchanger tubes in fluidized beds  

Microsoft Academic Search

This final report describes the activities of the 3-year project entitled Erosion of Heat Exchanger Tubes In Fluidized Beds.'' which was completed at the end of 1990. Project accomplishments include the collection of a substantial body of wear data In a 24in. [times] 24in. fluidized bed, comparative wear results In a 6in. [times] 6in. fluidized bed, the development of a

E. K. Johnson; R. L. C. Flemmer

1991-01-01

439

Vegetation and erosion: the case of forest wildfires with a special emphasis on Portugal  

NASA Astrophysics Data System (ADS)

Vegetation or, to be more precise, the lack of it is widely regarded to play a key role in enhanced overland flow generation and associated sediment losses following wildfires. Nonetheless, as pointed out by Shakesby and Doerr (2006) in their review paper on wildfire as a hydrological and geomorphological agent, there continues to be a need to further untangle the effects of vegetation destruction and its post-fire recovery from those of the fire-induced changes in other factors, of which soil water repellency has received particular research attention. This is an all but trivial task, however, especially under field conditions, since post-fire changes in potentially influencing factors can be expected to correlate with time after fire and, thus, with each other, even if these factors are in fact themselves unrelated. Post-fire erosion control measures commonly aim at decreasing bare soil cover and, thereby, are perhaps easily taken to invoke the role of vegetation in reducing erosion risk. In the case of simple mulching, for example with straw, the provided cover rather emulates the function of a litter layer than that of vegetation. Furthermore, the presence of mulch, except perhaps immediately after its application, may well affect other factors that potentially play a direct role in runoff generation and soil erosion, including vegetation regeneration itself. The proposed presentation will involve a critical review of a selected number of published erosion studies that have or have not clearly suggested or demonstrated the importance of vegetation destruction and recovery in observed soil erosion rates following forest wildfires. Due attention will be given to case studies on the effectiveness of cover-increasing post-fire management practices. The main conclusions of this review will be confronted with results obtained in the ongoing EROSFIRE-I and II projects in north-central Portugal on the short-term effects of forest fire on soil erosion. Possibly, an outlook will be included on the implications for a recently started study on the longer term effects of wildfire in the same region, comparing the situation of the past few decades with that under likely climate change scenarios with increased fire frequencies.

Keizer, J. J.; Nunes, J. P.; Malvar, M. C.; Maia, P. A. A.; Varela, M. E. T.

2009-04-01

440

The Influence of Woodland Encroachment on Runoff and Erosion in Sagebrush Steppe Systems, Great Basin, USA.  

NASA Astrophysics Data System (ADS)

Pinyon and juniper woodlands have expanded 10 to 30% in the past 30 years and now occupy nearly 20 million hectares of sagebrush shrub steppe in the Great Basin Region and Colorado Plateau, USA. The conversion of sagebrush steppe to pinyon and juniper woodlands has been linked to changes in plant community structure and composition and respective increases in overland flow and erosion from these landscapes. The Sagebrush Steppe Treatment Evaluation Project (SageSTEP, www.sagestep.org) was implemented in 2005 as a 5 year interdisciplinary research study to evaluate restoration methodologies for sagebrush rangelands degraded by woodland and grassland encroachment over a six state area within the Great Basin. The hydrology component of SageSTEP focuses on the relationships between changes in vegetation and groundcover and runoff/erosion processes. In 2006, 140 small scale (0.5 m2) rainfall simulations were conducted at 2 locations within the Great Basin to determine whether critical thresholds exist in vegetation and ground cover that significantly influence infiltration, runoff, and erosion in pinyon and juniper woodlands. Simulation plots were distributed on interspaces (areas between shrub/tree canopies) and juniper, pinyon, and shrub coppices (areas underneath canopy). Water drop penetration times and litter depths were also collected for each plot to explore controls on soil hydrophobicity. Preliminary results suggest a positive correlation between litter depth and hydrophobicity, as soils under thick pinyon and juniper coppices are strongly water repellant and soils in interspaces and under shrub coppices are easily wettable. Interspace plots with varying amounts of grasses and forbs have the highest erosion and runoff rates due to higher percentages of bare ground and relatively low soil stability. Pinyon coppices have the least runoff and erosion due to very high litter depths and low bare ground cover, even though surface soils are hydrophobic. Juniper and shrub coppice plots produce a similar amount of sediment, but juniper coppices produce significantly more runoff. Lower sediment concentrations from juniper coppice plots are attributed to higher litter depths, higher surface soil stability, and a lower percent of bare ground, while high runoff rates are attributed to higher soil surface water repellency. Results suggest that runoff and erosion from woodland encroachment sites are highly influenced by the amount of ground cover and strength of water repellency.

Pierson, F. B.; Kormos, P. R.; Williams, C. J.

2007-12-01

441

Erosion Management of Construction Sites  

NASA Astrophysics Data System (ADS)

Improvements in medical technology and improved lifestyles around the globe have resulted in the population growth trend we see today. The outcome is an ever-increasing demand in construction activities, be it for housing purposes or to provide for additional infrastructures to sustain the population growth and improved lifestyles. Indirect impact of this increase in construction activities is an increase in soil erosion from these (construction sites) activities, accelerating the global threat posed by massive soil erosion from human induced activities. While little, if any, can be done to stop the natural erosion process, timely actions can be taken to reduce erosion resulting from construction activities. The constraint, however, is to strike a balance between adverse economic impacts and associated environmental hazards. This is where effective use can be made of mathematical models specifically developed with aims of predicting soil erosion. For construction activities, these mathematical models can be used to compare adverse impacts of different management practices, with the objective of choosing the most appropriate (i.e. Best) Management Practice (BMP) for minimizing adverse environmental effects. With a plethora of erosion models available, with varied degree of data requirements and associated reliabilities, the dilemma planners and managers face in selecting a set of BMPs for reducing soil erosion from construction activities is the selection of a suitable model itself. This paper addresses this dilemma through selection of a simple yet reliable model that will assist the planners, developers and decision makers in comparing impacts of a range of management practices. The result is the selection of management practices that will meet the economic requirements without causing adverse environmental impacts.

Pudasaini, M. S.; Shrestha, S. P.

2003-12-01

442

Glacier Erosion and Response to Climate in Chilean Patagonia  

NASA Astrophysics Data System (ADS)

A vibrant dimension in current research on landscape evolution is the potential impact of climate change on erosion rates due to differences in efficiency of glacial and non-glacial erosion processes. The climate-sensitive rate and spatial distribution of erosion can be as important as the tectonic environment in determining the development of mountain ranges. To evaluate properly how glacial erosion influences orogenic processes and reflects climate variability, it is necessary to understand how ice dynamics control erosion rates. The Patagonian Andes are a unique laboratory for documenting glacial erosion in a range of precipitation and thermal regimes, as zonal atmospheric circulation in the region creates strong latitudinal gradients. We will present relevant findings from two tidewater glaciers in Chilean Patagonia: San Rafael glacier, which drains the northern portion of the North Patagonian Icefield (46.6S, 74W), and Marinelli glacier, the largest glacier in the Cordillera Darwin of Tierra del Fuego (54.6S, 69W). Both glaciers have been in steady retreat during the latter half of the 20th century, and both calve into a fjord or lagoon, which provides an efficient trap for the sediment eroded by the glacier and deposited at the calving front. The reconstructed flux of ice into the glaciers is compared to the retreat of the ice fronts and to the sediment flux to examine the influence of ice dynamics on the rate of glacier erosion. NCEP-NCAR Reanalysis climate data, adjusted to local conditions by correlation with automatic weather stations installed at the glacier termini and coupled to a model of orographic enhancement of precipitation over the glacier basin, were used to reconstruct the daily precipitation input into and ablation output from the glaciers during the last 50 years. The sediment flux out of the glaciers during this period was calculated from acoustic reflection profiles of the sediments accumulated in the proglacial fjords, and used to infer erosion rates. Preliminary results indicate 1) that high rates of retreat of the ice front occur during years in which the total input of snow into the glacier is balanced by the total ablation, and hence the residual flux of ice at the terminus is insufficient to compensate for the calving, and 2) that the highest basin- wide erosion rates reflect years in which total ice accumulation is lower and retreat rates are high. Interestingly, basin-wide erosion rates from these glaciers are up to an order of magnitude higher than long- term exhumation rates derived from detrital apatite thermochronometry in the basins, indicating that current rates of erosion far exceed long-term rates, and are reflective of periods of warming climate and enhanced glacial retreat.

Koppes, M.; Hallet, B.; Stewart, R.

2006-12-01

443

A 30?000 yr record of erosion rates from cosmogenic 10Be in Middle European river terraces  

NASA Astrophysics Data System (ADS)

Cosmogenic 10Be in river-borne quartz sand records a time-integrated erosion rate representative of an entire drainage basin. When sequestered in a terrace of known age, paleo-erosion rates may be recovered from the nuclide content of the terrace material. Paleo-erosion rates between 30 and 80 mm/kyr are determined from terrace sediments 200 to 30?000 yr in age of the Allier and Dore Rivers, France, and the Meuse (Maas) River, the Netherlands. Erosion rates determined from cosmogenic nuclides on terraces from the Allier River are consistent with rates derived from the sedimentary fill of a lake in the Allier catchment. A strong decrease in cosmogenic nuclide-derived erosion rates from terraces of the Meuse River with Late Pleistocene to Holocene age is observed. The paleo-erosion signal from cosmogenic nuclides records projection of the elevated Late Pleistocene erosion rate into the time-integrated rates derived from Middle European rivers.

Schaller, M.; von Blanckenburg, F.; Veldkamp, A.; Tebbens, L. A.; Hovius, N.; Kubik, P. W.

2002-11-01

444

Control research in windpower project 506259-1 control FOA, stage 1  

Microsoft Academic Search

A simplified rotor blade control for engines with variable speed; resonance compensation; and turbulence and gust models for controller development are discussed. Control of windpowered generators, and the simulation of a stochastic process with nonrational spectrum are considered. Computer control programs for a windpowered electric power plant are mentioned.

E. Ulen

1986-01-01

445

Overview of implementing a project control system in the nuclear utility industry  

SciTech Connect

During the late 1980s, a metamorphosis began at Florida Power and Light Company (FPL). A strategic step in nuclear engineering's efforts to become more cost effective began in January 1990. A project control department was formed. The initial mission was to provide support for nuclear engineering design activities associated with FPL's two twin-unit nuclear power generation facilities - Turkey Point and St. Lucie. Later, the goal expanded to include the division's materials management, nuclear licensing, and information management departments. The project control group was organized along the lines of the organizations served. Separate dedicated groups were established for each plant. Since most engineering activity was based at the Juno Beach headquarters, the project control staff also was based there.

Cooprider, D.H. (Pacific Inst. of Seattle, WA (United States))

1994-03-01

446

The erosive effects of racism: reduced self-control mediates the relation between perceived racial discrimination and substance use in African American adolescents.  

PubMed

Perceived racial discrimination, self-control, anger, and either substance use or use cognitions were assessed in 2 studies conducted with samples of African American adolescents. The primary goal was to examine the relation between discrimination and self-control over time; a 2nd goal was to determine whether that relation mediates the link between discrimination and substance use found in previous research. Study 1, which included a latent growth curve analysis with 3 waves of data, indicated that experience with discrimination (from age 10 years to age 18 years) was associated with reduced self-control, which then predicted increased substance use. Additional analyses indicated anger was also a mediator of this discrimination to use relation. Study 2, which was experimental, showed that envisioning an experience involving discrimination was associated with an increase in substance-related responses to double entendre words (e.g., pot, roach) in a word association task, especially for participants who were low in dispositional self-control. The effect was again mediated by reports of anger. Thus, the "double mediation" pattern was discrimination ? more anger and reduced self-control ? increased substance use and/or substance cognitions. Results are discussed in terms of the long-term impact of discrimination on self-control and health behavior. Implications for interventions aimed at ameliorating the negative effects of discrimination and low self-control on health are also discussed. PMID:22390225

Gibbons, Frederick X; O'Hara, Ross E; Stock, Michelle L; Gerrard, Meg; Weng, Chih-Yuan; Wills, Thomas A

2012-03-05

447

The conceptual framework of the International Tobacco Control (ITC) Policy Evaluation Project  

PubMed Central

This paper describes the conceptual model that underlies the International Tobacco Control Policy Evaluation Project (ITC Project), whose mission is to measure the psychosocial and behavioural impact of key policies of the Framework Convention on Tobacco Control (FCTC) among adult smokers, and in some countries, among adult non?smokers and among youth. The evaluation framework utilises multiple country controls, a longitudinal design, and a pre?specified, theory?driven conceptual model to test hypotheses about the anticipated effects of specific policies. The ITC Project consists of parallel prospective cohort surveys of representative samples of adult smokers currently in nine countries (inhabited by over 45% of the world's smokers), with other countries being added in the future. Collectively, the ITC Surveys constitute the first?ever international cohort study of tobacco use. The conceptual model of the ITC Project draws on the psychosocial and health communication literature and assumes that tobacco control policies influence tobacco related behaviours through a causal chain of psychological events, with some variables more closely related to the policy itself (policy?specific variables) and other variables that are more downstream from the policy, which have been identified by health behaviour and social psychological theories as being important causal precursors of behaviour (psychosocial mediators). We discuss the objectives of the ITC Project and its potential for building the evidence base for the FCTC.

Fong, G T; Cummings, K M; Borland, R; Hastings, G; Hyland, A; Giovino, G A; Hammond, D; Thompson, M E

2006-01-01

448

ERMiT: Estimating Post-Fire Erosion in Probabilistic Terms  

NASA Astrophysics Data System (ADS)

Mitigating the impact of post-wildfire runoff and erosion on life, property, and natural resources have cost the United States government tens of millions of dollars over the past decade. The decision of where, when, and how to apply the most effective mitigation treatments requires land managers to assess the risk of damaging runoff and erosion events occurring after a fire. The Erosion Risk Management Tool (ERMiT) is a web-based application that estimates erosion in probabilistic terms on burned and recovering forest, range, and chaparral lands. Unlike most erosion prediction models, ERMiT does not provide `average annual erosion rates;' rather, it provides a distribution of erosion rates with the likelihood of their occurrence. ERMiT combines rain event variability with spatial and temporal variabilities of hillslope burn severity, soil properties, and ground cover to estimate Water Erosion Prediction Project (WEPP) model input parameter values. Based on 20 to 40 individual WEPP runs, ERMiT produces a distribution of rain event erosion rates with a probability of occurrence for each of five post-fire years. Over the 5 years of modeled recovery, the occurrence probability of the less erodible soil parameters is increased and the occurrence probability of the more erodible soil parameters is decreased. In addition, the occurrence probabilities and the four spatial arrangements of burn severity (arrangements of overland flow elements (OFE's)), are shifted toward lower burn severity with each year of recovery. These yearly adjustments are based on field measurements made through post-fire recovery periods. ERMiT also provides rain event erosion rate distributions for hillslopes that have been treated with seeding, straw mulch, straw wattles and contour-felled log erosion barriers. Such output can help managers make erosion mitigation treatment decisions based on the probability of high sediment yields occurring, the value of resources at risk for damage, cost, and other management considerations.

Pierson, F. B.; Robichaud, P. R.; Elliot, W. J.; Hall, D. E.; Moffet, C. A.

2006-12-01

449

ERIP Project No. 670, Nevada Energy Control Systems, Inc.. Final techincal progress report  

SciTech Connect

In order to gauge the effectiveness of the ERIP Project No. 670, Nevada Energy Control Systems, Inc., Grant Number DE-FG01-96EE15670, the Statement of Work must be compared to the achievements by NECSI during the grant period. The following report reflects the aforementioned statement and is coordinated directly with it. The project goal is to gather data and test in order to validate earlier tests of energy savings,safety,reliability and practicality of the NECSI Evaporator Fan Controller in order to fully commercialize and market the product.

Kimber, D.J.

1998-02-11

450

Effect of stone coverage on soil erosion  

NASA Astrophysics Data System (ADS)

Soil surface coverage has a significant impact on water infiltration, runoff and soil erosion yields. In particular, surface stones protect the soils from raindrop detachment, they retard the overland flow therefore decreasing its sediment transport capacity, and they prevent surface sealing. Several physical and environmental factors control to what extent stones on the soil surface modify the erosion rates and the related hydrological response. Among the most important factors are the moisture content of the topsoil, stone size, emplacement, coverage density and soil texture. Owing to the different inter-related processes, there is ambiguity concerning the quantitative effect of stones, and process-based understanding is limited. Experiments were performed (i) to quantify how stone features affect sediment yields, (ii) to understand the local