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Sample records for embankments and retaining walls

  1. 2. VIEW OF WEST HEADWALL AND WING WALL, FROM EMBANKMENT ...

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

    2. VIEW OF WEST HEADWALL AND WING WALL, FROM EMBANKMENT TO THE SOUTHWEST, FACING NORTHEAST. - Cut Stone Bridge, Southern Pacific Railroad line spanning runoff channel at South Spruce Avenue, South San Francisco, San Mateo County, CA

  2. Concrete and timber retaining wall and telegraph pole, milepost 145 ...

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

    Concrete and timber retaining wall and telegraph pole, milepost 145 vicinity, looking northeast. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  3. RIVER AND ROAD VIEW SHOWING METAL CRIB RETAINING WALLS AT ...

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

    RIVER AND ROAD VIEW SHOWING METAL CRIB RETAINING WALLS AT RIGHT, FACING SOUTHWEST. PHOTO IS TAKEN FROM SAME POSITION AS PHOTO NO. 84, BUT WITH LONG LENS - Generals Highway, Three Rivers, Tulare County, CA

  4. DETAIL VIEW OF SIDEWALK, CLINKER BRICK RETAINING WALL, AND ENTRANCE ...

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

    DETAIL VIEW OF SIDEWALK, CLINKER BRICK RETAINING WALL, AND ENTRANCE WAY TO WILLIAM R. THORSEN HOUSE BY CHARLES & HENRY GREENE, 1909. EAST SIDE OF PIEDMONT AVENUE LOOKING SE. Photograph by Fredrica Drotos and Michael Kelly, July 9, 2006 - Piedmont Way & the Berkeley Property Tract, East of College Avenue between Dwight Way & U.C. Memorial Stadium, Berkeley, Alameda County, CA

  5. 10. Photocopy copy of historic photograph showing retaining wall and ...

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

    10. Photocopy copy of historic photograph showing retaining wall and gabeon of lower dam. Date and photographer unknown. (original in possession of United States Department of Agriculture-Forest Service-Allegheny National Forest) VIEW NORTHEAST - Loleta Recreation Area, Lower Dam, 6 miles Southeast of interesection of State Route 24041 & State Route 66, Loleta, Elk County, PA

  6. Detail of staircase (stepped ramp) and retaining wall at West ...

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

    Detail of staircase (stepped ramp) and retaining wall at West 102nd Street, soccer field at right, looking south, with London Plane trees surrounding field. - Henry Hudson Parkway, Extending 11.2 miles from West 72nd Street to Bronx-Westchester border, New York County, NY

  7. Square concrete culvert and concrete retaining wall, 1/2 mile east ...

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

    Square concrete culvert and concrete retaining wall, 1/2 mile east of Indigo Tunnel, milepost 128. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  8. 26. GARAGE AND RETAINING WALLS NEAR SAR3. NOTE SEVEN OAKS ...

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

    26. GARAGE AND RETAINING WALLS NEAR SAR-3. NOTE SEVEN OAKS DAM ROAD CONSTRUCTION SCAR ON MOUNTAINSIDE IN DISTANCE. VIEW TO NORTHWEST. - Santa Ana River Hydroelectric System, Redlands, San Bernardino County, CA

  9. 4. CONSTRUCTION DETAIL, SW CORNER, SHOWING RETAINING WALL, BRIDGE WALL ...

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

    4. CONSTRUCTION DETAIL, SW CORNER, SHOWING RETAINING WALL, BRIDGE WALL AND EROSION ON ROAD SURFACE. - Bridalveil Fall Bridge No. 3, Spanning Bridalveil Creek on carriage road, Yosemite Village, Mariposa County, CA

  10. Dynamic response of cantilever retaining walls

    SciTech Connect

    Veletsos, A.S.; Younan, A.H.; Bandyopadhyay, K.

    1996-10-01

    A critical evaluation is made of the response to horizontal ground shaking of flexible cantilever retaining walls that are elastically constrained against rotation at their base. The retained medium is idealized as a uniform, linear, viscoelastic stratum of constant thickness and semi-infinite extent in the horizontal direction. The parameters varied include the flexibilities of the wall and its base, the properties of the retained medium, and the characteristics of the ground motion. In addition to long-period, effectively static excitations, both harmonic base motions and an actual earthquake record are considered. The response quantities examined include the displacements of the wall relative to the moving base, the wall pressures, and the associated shears and bending moments. The method of analysis employed is described only briefly, emphasis being placed on the presentation and interpretation of the comprehensive numerical solutions. It is shown that, for realistic wall flexibilities, the maximum wall forces are significantly lower than those obtained for fixed-based rigid walls and potentially of the same order of magnitude as those computed by the Mononobe-Okabe method.

  11. Automatic Thickness and Volume Estimation of Sprayed Concrete on Anchored Retaining Walls from Terrestrial LIDAR Data

    NASA Astrophysics Data System (ADS)

    Martínez-Sánchez, J.; Puente, I.; GonzálezJorge, H.; Riveiro, B.; Arias, P.

    2016-06-01

    When ground conditions are weak, particularly in free formed tunnel linings or retaining walls, sprayed concrete can be applied on the exposed surfaces immediately after excavation for shotcreting rock outcrops. In these situations, shotcrete is normally applied conjointly with rock bolts and mesh, thereby supporting the loose material that causes many of the small ground falls. On the other hand, contractors want to determine the thickness and volume of sprayed concrete for both technical and economic reasons: to guarantee their structural strength but also, to not deliver excess material that they will not be paid for. In this paper, we first introduce a terrestrial LiDAR-based method for the automatic detection of rock bolts, as typically used in anchored retaining walls. These ground support elements are segmented based on their geometry and they will serve as control points for the co-registration of two successive scans, before and after shotcreting. Then we compare both point clouds to estimate the sprayed concrete thickness and the expending volume on the wall. This novel methodology is demonstrated on repeated scan data from a retaining wall in the city of Vigo (Spain), resulting in a rock bolts detection rate of 91%, that permits to obtain a detailed information of the thickness and calculate a total volume of 3597 litres of concrete. These results have verified the effectiveness of the developed approach by increasing productivity and improving previous empirical proposals for real time thickness estimation.

  12. Oblique view of Bonita Ridge Access Road Retaining Wall, showing ...

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

    Oblique view of Bonita Ridge Access Road Retaining Wall, showing southernmost portion of intact wall and portion of concrete drainage ditch from Signal Corps Radar 296 Station 5 Transmitter Building foundation above, camera facing west-north - Fort Barry, Bonita Ridge Access Road, Retaining Wall, Point Bonita, Marin Headlands, Sausalito, Marin County, CA

  13. Dynamic response of flexible retaining walls

    SciTech Connect

    Younan, A.H.; Veletsos, A.S.; Bandyopadhyay, K.

    1997-01-01

    Making use of an extension of a recently proposed, relatively simple, approximate method of analysis, a critical evaluation is made of the response to horizontal ground shaking of flexible walls retaining a uniform, linear, viscoelastic stratum of constant thickness and semiinfinite extent in the horizontal direction. Both cantilever and top-supported walls are examined. Following a detailed description of the method and of its rate of convergence, comprehensive numerical solutions are presented that elucidate the action of the system and the effects of the various parameters involved. The parameters varied include the flexibility of the wall, the condition of top support, and the characteristics of the ground motion. The effects of both harmonic base motions and an actual earthquake record are examined. Special attention is paid to the effects of long-period, effectively static excitations. A maximum dynamic response is then expressed as the product of the corresponding static response and an appropriate amplification or deamplification factor. The response quantities examined include the displacements of the wall relative to the moving base, the dynamic wall pressures, and the total wall force, base shear and base moment.

  14. Inventory and Comparison of Floodplain Embankment along Large Rivers

    NASA Astrophysics Data System (ADS)

    Hudson, Paul

    2016-04-01

    Flood control is a fundamental human response to flood risk, and floodplain embankment by dike (levee) construction is among the oldest forms of societal impacts to natural systems. Large lowland alluvial valleys are some of Earth's most distinctive environments and represent high levels of geodiversity and biodiversity. Embankment of large lowland alluvial river valleys alters fundamental processes related to floodplain hydrology, sedimentation, and ecology and eventually results in a transformation of the embanked floodplain environment. Since embankment, many large lowland floodplains have been heaviliy modified for floodplain agriculture and include high population densities, increasing flood risk. While there is much discussion about the pros and cons of dike construction and the impact to floodplain environments there is no systematic inventory which documents the magnitude and intensity of floodplain embankment to lowland rivers. In this study we characterize and inventory floodplain embankment along large lowland alluvial valleys. The review includes some of Earth's largest embanked fluvial systems, and primarilly focuses on northern hemisphere rivers in the United States, Europe and Asia. Data sources includes the U.S. National Levee Database, SRTM DEM, recently obtained high resolution satellite imagery, various national topographic map series, and hydrologic data from the published literature. These data are integrated into a GIS framework to facilitate the measurement and characterisation of floodplain embankment. Spatial indices of floodplain embankment are constructed, including the intensity of embankment and how it relates to the natural floodplain and constriction of flooding.

  15. Detail of basaltic rock retaining walls just below top switchback. ...

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

    Detail of basaltic rock retaining walls just below top switchback. 500 ft long retaining wall at left, scale figure in distance, view south. - La Bajada Historic Trails and Roads, Approximately 1 mile East/Northeast of intersection of State Highway 16 and Indian Service Road 841, La Bajada, Santa Fe County, NM

  16. 6. CREST ROAD ON UPPER EMBANKMENT, SHOWING MASONRY UPSTREAM PARAPET ...

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

    6. CREST ROAD ON UPPER EMBANKMENT, SHOWING MASONRY UPSTREAM PARAPET WALL (LEFT) AND ENTRANCE TO DEER FLAT NAMPA CANAL HEADWORKS (ALSO LEFT). VIEW TO WEST. - Boise Project, Deer Flat Embankments, Lake Lowell, Nampa, Canyon County, ID

  17. Aspen Tension Wood Fibers Contain β-(1---> 4)-Galactans and Acidic Arabinogalactans Retained by Cellulose Microfibrils in Gelatinous Walls.

    PubMed

    Gorshkova, Tatyana; Mokshina, Natalia; Chernova, Tatyana; Ibragimova, Nadezhda; Salnikov, Vadim; Mikshina, Polina; Tryfona, Theodora; Banasiak, Alicja; Immerzeel, Peter; Dupree, Paul; Mellerowicz, Ewa J

    2015-11-01

    Contractile cell walls are found in various plant organs and tissues such as tendrils, contractile roots, and tension wood. The tension-generating mechanism is not known but is thought to involve special cell wall architecture. We previously postulated that tension could result from the entrapment of certain matrix polymers within cellulose microfibrils. As reported here, this hypothesis was corroborated by sequential extraction and analysis of cell wall polymers that are retained by cellulose microfibrils in tension wood and normal wood of hybrid aspen (Populus tremula × Populus tremuloides). β-(1→4)-Galactan and type II arabinogalactan were the main large matrix polymers retained by cellulose microfibrils that were specifically found in tension wood. Xyloglucan was detected mostly in oligomeric form in the alkali-labile fraction and was enriched in tension wood. β-(1→4)-Galactan and rhamnogalacturonan I backbone epitopes were localized in the gelatinous cell wall layer. Type II arabinogalactans retained by cellulose microfibrils had a higher content of (methyl)glucuronic acid and galactose in tension wood than in normal wood. Thus, β-(1→4)-galactan and a specialized form of type II arabinogalactan are trapped by cellulose microfibrils specifically in tension wood and, thus, are the main candidate polymers for the generation of tensional stresses by the entrapment mechanism. We also found high β-galactosidase activity accompanying tension wood differentiation and propose a testable hypothesis that such activity might regulate galactan entrapment and, thus, mechanical properties of cell walls in tension wood. PMID:26378099

  18. VIEW OF RETAINING WALL BEHIND FACILITY 532. VIEW FACING EAST ...

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

    VIEW OF RETAINING WALL BEHIND FACILITY 532. VIEW FACING EAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  19. 24. VIEW TO NORTHEAST; OBLIQUE VIEW OF SOUTH RETAINING WALL ...

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

    24. VIEW TO NORTHEAST; OBLIQUE VIEW OF SOUTH RETAINING WALL AND PARKING STRUCTURE BELOW REA LOADING DOCK (Asano) - Los Angeles Union Passenger Terminal, Mail, Baggage, & Express Building, 800 North Alameda Street, Los Angeles, Los Angeles County, CA

  20. Dynamic characteristics and seismic stability of expanded polystyrene geofoam embankments

    NASA Astrophysics Data System (ADS)

    Amini, Zahra A.

    Expanded Polystyrene (EPS) geofoam has become a preferred material in various construction applications due to its light weight. Application of EPS accelerates the projects particularly on soft soils. The focus of this research is on the application of the EPS in embankments and its behavior mainly under harmonic vibration. The goal of this study was to investigate dynamic characteristics of freestanding vertical EPS geofoam embankment and address potential seismic issues that result from the distinguished dynamic behavior of such systems due to the layered and discrete block structure. A series of experimental studies on EPS 19 and a commercially available adhesive was conducted. Two-dimensional numerical analyses were performed to replicate the response of EPS geofoam embankment to horizontal and vertical harmonic motions. The results of the analyses have shown that for some acceleration amplitude levels interlayer sliding is expected to occur in EPS geofoam embankments almost immediately after the start of the base excitation; however, as a highly efficient energy dissipation mechanism sliding ceases rapidly. Shear keys and adhesive may be used to prevent interlayer sliding if they cover the proper extent of area of the embankment. EPS blocks placed in the corners of the embankment and at the edges of the segment prohibited from sliding may experience high stress concentrations. The embankment may show horizontal sway and rocking once sliding is prevented.

  1. Seismic analysis for translational failure of landfills with retaining walls.

    PubMed

    Feng, Shi-Jin; Gao, Li-Ya

    2010-11-01

    In the seismic impact zone, seismic force can be a major triggering mechanism for translational failures of landfills. The scope of this paper is to develop a three-part wedge method for seismic analysis of translational failures of landfills with retaining walls. The approximate solution of the factor of safety can be calculated. Unlike previous conventional limit equilibrium methods, the new method is capable of revealing the effects of both the solid waste shear strength and the retaining wall on the translational failures of landfills during earthquake. Parameter studies of the developed method show that the factor of safety decreases with the increase of the seismic coefficient, while it increases quickly with the increase of the minimum friction angle beneath waste mass for various horizontal seismic coefficients. Increasing the minimum friction angle beneath the waste mass appears to be more effective than any other parameters for increasing the factor of safety under the considered condition. Thus, selecting liner materials with higher friction angle will considerably reduce the potential for translational failures of landfills during earthquake. The factor of safety gradually increases with the increase of the height of retaining wall for various horizontal seismic coefficients. A higher retaining wall is beneficial to the seismic stability of the landfill. Simply ignoring the retaining wall will lead to serious underestimation of the factor of safety. Besides, the approximate solution of the yield acceleration coefficient of the landfill is also presented based on the calculated method. PMID:20541389

  2. Ecohydrology of an Embanked Lowland UK River Meadow and the Effects of Embankment Removal

    NASA Astrophysics Data System (ADS)

    Clilverd, H.; Thompson, J.; Sayer, C.; Heppell, K.; Axmacher, J.

    2012-12-01

    Pristine riparian and floodplain ecosystems are in a state of dynamic balance due to the regular floods that continuously reshape river channels and their banks, and transport water, sediment and nutrients onto the floodplain. However, the natural flow regime of many rivers has been altered by channelization and artificial embankments designed to protect agricultural and urban developments from flooding. This has had a lasting impact on the hydrological characteristics of floodplain ecosystems and the biological communities that inhabit them. Floodplain restoration, through embankment removal and the reconfiguration of river channels, is now being increasingly employed to re-establish river-floodplain connections and assist the recovery of lost or declining species. In order to manage a river restoration site for plant biodiversity, it is necessary to understand the physical and nutritional status of the root environment. We conducted fine scale (10 × 10 m) botanical and chemical sampling on a 3 ha embanked grassland meadow in Norfolk (Eastern England) and assessed the spatial pattern of plant communities in relation to soil physicochemical conditions. Continuous measurements of groundwater depth and river stage were collectively used to determine changes in the hydrological regime following embankment-removal. Prior to the restoration the meadow plant community was dominated by Holcus lanatus, Ranunculus repens and Agrostis stolonifera. Species richness was fairly low (mean: 8 spp. per m2), and indices of alpha-diversity suggest low heterogeneity of the plant assemblages (mean values for Shannon's Diversity and 1/Simpson's Diversity = 1.4 and 3.4, respectively). Top soils were moderately fertile, with mean respective Olsen P and plant available potassium concentrations of 9.1 mg P kg-1and 1.6 mg K+g-1. Plant available ammonium and nitrate concentrations were on average 31.7 mg NH4+-N kg-1 and 2.8 mg NO3--N kg-1, respectively. River water was enriched in nitrate

  3. Chronic cutaneous chest wall fistula and gallstone empyema due to retained gallstones

    PubMed Central

    Gaster, Richard S; Berger, Aaron J; Ahmadi-Kashani, Mastaneh; Shrager, Joseph B; Lee, Gordon K

    2014-01-01

    We report a case of a 72-year-old man who presented with a persistent pleural effusion and painful abscess in the right lower chest wall 6 months following a laparoscopic cholecystectomy. The patient subsequently developed a chronic cutaneous chest wall fistula requiring a large resection and complex closure. The complication was likely secondary to intraoperative spillage of gallstones. While previous reports describe gallstone spillage in the abdominal cavity as benign, this case illustrates that stones left in the abdominal cavity can potentially lead to significant morbidity. Therefore, stones should be diligently removed from the abdominal cavity when spillage occurs. In addition, it is important that operative notes reflect the occurrence of stone spillage so stones may be suspected when a patient presents with an abdominal or thoracic infection following a cholecystectomy. PMID:25123567

  4. 13. View of the swimming pool retaining wall, the steps, ...

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

    13. View of the swimming pool retaining wall, the steps, ascending to the rock garden, and the Belvedere (less distant view). The view includes the bronze sculpture "Bather at the Seine" by Maillol (Ca. 1921), and a honey locust (Gleditsia triacanthos). - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

  5. 12. View of the swimming pool retaining wall, the steps, ...

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

    12. View of the swimming pool retaining wall, the steps, ascending to the rock garden, and the Belvedere (more distant view). The view includes the bronze sculpture "Bather at the Seine" by Maillol (Ca. 1921), and a honey locust (Gleditsia triacanthos). - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

  6. 14. DETAIL OF TRANSITION FROM WING WALL TO CONCRETE RETAINING ...

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

    14. DETAIL OF TRANSITION FROM WING WALL TO CONCRETE RETAINING WALL AT SOUTHERN END OF DAM - Upper Doughty Dam, 200 feet west of Garden State Parkway, 1.7 miles west of Absecon, Egg Harbor City, Atlantic County, NJ

  7. Development and characterization of soil material parameters for embankment breach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite the widespread use of earthen dams, the processes by which earthen embankments erode and fail when overtopped during extreme events are only imperfectly understood. Aging of these dams and the associated recent focus on dam rehabilitation has increased the need for new technology and tools ...

  8. 12. A VIEW LOOKING EAST, FROM ATOP THE RETAINING WALL ...

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

    12. A VIEW LOOKING EAST, FROM ATOP THE RETAINING WALL ON THE NORTHEAST ABUTMENT PROVIDES A COMPANION VIEW TO THE PREVIOUS PHOTOGRAPH. THE CLUB HOUSE, PORTIONS OF THE BOARDWALK, A PICNIC SHELTER AND THE SWIMMING STEPS ARE VISIBLE, ALONG WITH A PORTION OF THE NINETEENTH CENTURY BUILDING ON THE NORTH BANK WHICH IS NOW HOME TO COMMERCIAL ENDEAVORS - Delphi Bridge on U.S. Route 421, Spanning Deer Creek at U.S. Route 421, Delphi, Carroll County, IN

  9. 11. EAST VIEW OF RETAINING WALL C ON NORTH SIDE ...

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

    11. EAST VIEW OF RETAINING WALL C ON NORTH SIDE OF EASTBOUND TRAFFIC LANES, EAST OF HAMILTON AVENUE BRIDGE - Davison Freeway from M-10 to Oakland Avenue, Davison Freeway, M-10 to Highland Park, Highland Park, MI

  10. Stone retaining wall with telegraph pole along canal, milepost 146 ...

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

    Stone retaining wall with telegraph pole along canal, milepost 146 vicinity, looking northeast. - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  11. STONE RETAINING WALL IN CEMETERY CENTER, WITH BIVOUAC OF THE ...

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

    STONE RETAINING WALL IN CEMETERY CENTER, WITH BIVOUAC OF THE DEAD PLAQUE IN CENTER FOREGROUND. VIEW TO SOUTHEAST. - Fort Mackinac Post Cemetery, Mackinac State Park, Mackinac Island, Mackinac County, MI

  12. 15. VIEW LOOKING EAST, SHOWING RETAINING WALL ON EAST SIDE ...

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

    15. VIEW LOOKING EAST, SHOWING RETAINING WALL ON EAST SIDE OF PARK, SOUTH OF ENGINE HOUSE (4' X 5' negative) - Fairmount Waterworks, East bank of Schuylkill River, Aquarium Drive, Philadelphia, Philadelphia County, PA

  13. 1. VIEW TO SOUTH (RETAINING WALL OF ORE RECEIVING PLATFORM ...

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

    1. VIEW TO SOUTH (RETAINING WALL OF ORE RECEIVING PLATFORM TO LEFT). - Vanadium Corporation of America (VCA) Naturita Mill, Sampling Building & Ore Receiving Platform, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

  14. 6. TERRACED, STONE RETAINING WALLS BEHIND HOUSE No. 16. VIEW ...

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

    6. TERRACED, STONE RETAINING WALLS BEHIND HOUSE No. 16. VIEW TO WEST. - Rainbow Hydroelectric Facility, On north bank of Missouri River 2 miles Northeast of Great Falls, & end of Rainbow Dam Road, Great Falls, Cascade County, MT

  15. VIEW SHOWING THE ENTRY THROUGH THE RETAINING WALL (FOREGROUND) TO ...

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

    VIEW SHOWING THE ENTRY THROUGH THE RETAINING WALL (FOREGROUND) TO THE CONCRETE SLAB. NOTE THE 1¾" MOUNTING BOLTS FOR THE STEEL PLATE BASE OF THE 5" GUN, SET IN THE GUN BLOCK. STEEL REINFORCING RODS PROTRUDING FROM THE BROKEN TOPS OF THE RETAINING WALLS ARE ALSO VISIBLE. VIEW FACING EAST - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, South Gun Emplacement, Ford Island, Pearl City, Honolulu County, HI

  16. Characteristics of Wind Velocity and Temperature Change Near an Escarpment-Shaped Road Embankment

    PubMed Central

    Kim, Young-Moon; You, Ki-Pyo; You, Jang-Youl

    2014-01-01

    Artificial structures such as embankments built during the construction of highways influence the surrounding airflow. Various types of damage can occur due to changes in the wind velocity and temperature around highway embankments. However, no study has accurately measured micrometeorological changes (wind velocity and temperature) due to embankments. This study conducted a wind tunnel test and field measurement to identify changes in wind velocity and temperature before and after the construction of embankments around roads. Changes in wind velocity around an embankment after its construction were found to be influenced by the surrounding wind velocity, wind angle, and the level difference and distance from the embankment. When the level difference from the embankment was large and the distance was up to 3H, the degree of wind velocity declines was found to be large. In changes in reference wind velocities around the embankment, wind velocity increases were not proportional to the rate at which wind velocities declined. The construction of the embankment influenced surrounding temperatures. The degree of temperature change was large in locations with large level differences from the embankment at daybreak and during evening hours when wind velocity changes were small. PMID:25136681

  17. Characteristics of wind velocity and temperature change near an escarpment-shaped road embankment.

    PubMed

    Kim, Young-Moon; You, Ki-Pyo; You, Jang-Youl

    2014-01-01

    Artificial structures such as embankments built during the construction of highways influence the surrounding airflow. Various types of damage can occur due to changes in the wind velocity and temperature around highway embankments. However, no study has accurately measured micrometeorological changes (wind velocity and temperature) due to embankments. This study conducted a wind tunnel test and field measurement to identify changes in wind velocity and temperature before and after the construction of embankments around roads. Changes in wind velocity around an embankment after its construction were found to be influenced by the surrounding wind velocity, wind angle, and the level difference and distance from the embankment. When the level difference from the embankment was large and the distance was up to 3H, the degree of wind velocity declines was found to be large. In changes in reference wind velocities around the embankment, wind velocity increases were not proportional to the rate at which wind velocities declined. The construction of the embankment influenced surrounding temperatures. The degree of temperature change was large in locations with large level differences from the embankment at daybreak and during evening hours when wind velocity changes were small. PMID:25136681

  18. Aspen Tension Wood Fibers Contain β-(1→4)-Galactans and Acidic Arabinogalactans Retained by Cellulose Microfibrils in Gelatinous Walls1[OPEN

    PubMed Central

    Gorshkova, Tatyana; Mokshina, Natalia; Chernova, Tatyana; Ibragimova, Nadezhda; Salnikov, Vadim; Mikshina, Polina; Tryfona, Theodora; Banasiak, Alicja; Immerzeel, Peter; Dupree, Paul; Mellerowicz, Ewa J.

    2015-01-01

    Contractile cell walls are found in various plant organs and tissues such as tendrils, contractile roots, and tension wood. The tension-generating mechanism is not known but is thought to involve special cell wall architecture. We previously postulated that tension could result from the entrapment of certain matrix polymers within cellulose microfibrils. As reported here, this hypothesis was corroborated by sequential extraction and analysis of cell wall polymers that are retained by cellulose microfibrils in tension wood and normal wood of hybrid aspen (Populus tremula × Populus tremuloides). β-(1→4)-Galactan and type II arabinogalactan were the main large matrix polymers retained by cellulose microfibrils that were specifically found in tension wood. Xyloglucan was detected mostly in oligomeric form in the alkali-labile fraction and was enriched in tension wood. β-(1→4)-Galactan and rhamnogalacturonan I backbone epitopes were localized in the gelatinous cell wall layer. Type II arabinogalactans retained by cellulose microfibrils had a higher content of (methyl)glucuronic acid and galactose in tension wood than in normal wood. Thus, β-(1→4)-galactan and a specialized form of type II arabinogalactan are trapped by cellulose microfibrils specifically in tension wood and, thus, are the main candidate polymers for the generation of tensional stresses by the entrapment mechanism. We also found high β-galactosidase activity accompanying tension wood differentiation and propose a testable hypothesis that such activity might regulate galactan entrapment and, thus, mechanical properties of cell walls in tension wood. PMID:26378099

  19. View looking SW at brick retaining wall running parallel to ...

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

    View looking SW at brick retaining wall running parallel to Jones Street showing bricked up storage vaults - Central of Georgia Railway, Savannah Repair Shops & Terminal Facilities, Brick Storage Vaults under Jones Street, Bounded by West Broad, Jones, West Boundary & Hull Streets, Savannah, Chatham County, GA

  20. 9. PHOTO LOOKING SOUTH FROM THE RETAINING WALL ON THE ...

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

    9. PHOTO LOOKING SOUTH FROM THE RETAINING WALL ON THE NORTH ABUTMENT REVEALS THE SOUTHEAST ABUTMENT. DETAILS OF THE CONCRETE WORK ON THE BALUSTRADE ARE ALSO VISIBLE - Delphi Bridge on U.S. Route 421, Spanning Deer Creek at U.S. Route 421, Delphi, Carroll County, IN

  1. The impact of road and railway embankments on runoff and soil erosion in eastern Spain

    NASA Astrophysics Data System (ADS)

    Pereira, P.; Gimeìnez-Morera, A.; Novara, A.; Keesstra, S.; Jordán, A.; Masto, R. E.; Brevik, E.; Azorin-Molina, C.; Cerdà, A.

    2015-12-01

    Road and railway infrastructure increased in the Mediterranean region during the last three decades. This included the building of embankments, which are assumed to be a~large source of sediments and runoff. However, little is known about soil erosion rates, the factors that control them, and the processes that contribute to detachment, transport and deposition of sediments from road and railway embankments. The objective of this study was therefore to assess the impacts of road and railway embankments as a source of sediment and water, and compare them to other land use types (citrus plantations and shrublands) representative of the Cànyoles watershed to evaluate the importance of road embankments as a~source of water and sediment under high magnitude low frequency rainfall events. Sixty rainfall experiments (1 m2 plots; 60 min duration; 78 mm h-1 rainfall intensity) were carried out on these land use types: 20 on two railway embankments (10 + 10), 20 on two road embankments (10 + 10), and 10 on citrus and 10 on shrubland. Road and railway embankments were characterized by bare soils with low organic matter and high bulk density. Erosion processes were more active in road, railway and citrus plots, and null in the shrublands. The non-sustainable soil erosion rates of 3 Mg ha-1 y-1 measured on the road embankments were due to the efficient runoff connectivity plus low infiltration rates within the plot as the runoff took less than one minute to reach the runoff outlet. Road and railway embankments are both an active source of sediments and runoff, and soil erosion control strategies must be applied. The citrus plantations also act as a~source of water and sediments (1.5 Mg ha-1 y-1), while shrublands are sediment sinks, as no overland flow was observed due to the high infiltration rates.

  2. Thermal Stability Analysis under Embankment with Asphalt Pavement and Cement Pavement in Permafrost Regions

    PubMed Central

    Jinping, Li; Xiaojuan, Quan

    2013-01-01

    The permafrost degradation is the fundamental cause generating embankment diseases and pavement diseases in permafrost region while the permafrost degradation is related with temperature. Based on the field monitoring results of ground temperature along G214 Highway in high temperature permafrost regions, both the ground temperatures in superficial layer and the annual average temperatures under the embankment were discussed, respectively, for concrete pavements and asphalt pavements. The maximum depth of temperature field under the embankment for concrete pavements and asphalt pavements was also studied by using the finite element method. The results of numerical analysis indicate that there were remarkable seasonal differences of the ground temperatures in superficial layer between asphalt pavement and concrete pavement. The maximum influencing depth of temperature field under the permafrost embankment for every pavement was under the depth of 8 m. The thawed cores under both embankments have close relation with the maximum thawed depth, the embankment height, and the service time. The effective measurements will be proposed to keep the thermal stabilities of highway embankment by the results. PMID:24027444

  3. Construction of an embankment with a fly and bottom ash mixture: field performance study

    SciTech Connect

    Yoon, S.; Balunaini, U.; Yildirim, I.Z.; Prezzi, M.; Siddiki, N.Z.

    2009-06-15

    Fly ash and bottom ash are coal combustion by-products (CCBPs) that are generated in large quantities throughout the world. It is often economical to dispose ash as mixtures rather than separately; that notwithstanding, only a few studies have been performed to investigate the behavior of fly and bottom ash mixtures, particularly those with high contents of fly ash. Also, there is very limited data available in the literature on the field performance of structures constructed using ash mixtures. This paper describes the construction and the instrumentation of a demonstration embankment built with an ash mixture (60:40 by weight of fly ash:bottom ash) on State Road 641, Terre Haute, Ind. Monitoring of the demonstration embankment was conducted for a period of 1 year from the start of construction of the embankment. The settlement of the embankment stabilized approximately 5 months after the end of its construction. According to horizontal inclinometer readings, the differential settlement at the top of the embankment is about 5 mm. Results from field quality control tests performed during construction of the demonstration embankment and monitoring data from vertical and horizontal inclinometers and settlement plates indicate that the ash mixture investigated can be considered an acceptable embankment construction material.

  4. A counterfort versus a cantilever retaining wall - a seismic equivalence

    NASA Astrophysics Data System (ADS)

    Chugh, Ashok K.

    2005-08-01

    A procedure is presented to develop geometric dimensions and material property values for a model cantilever wall from those of a prototype counterfort wall such that the model wall will simulate the response of the prototype wall for seismic loads. The equivalency criteria are given. A sample problem is included to illustrate the use of the proposed procedure. Accuracy of results is discussed. Published in 2005 by John Wiley & Sons, Ltd.

  5. 6. "TEST STAND NO. 13, RETAINING WALLS & APRON, SECTIONS ...

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

    6. "TEST STAND NO. 1-3, RETAINING WALLS & APRON, SECTIONS & ELEVATIONS." Specifications No. OC11-50-10; Drawing No. 60-09-06; no sheet number within title block. D.O. SERIES 1109/20, Rev. B. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract DA-04-353 Eng. 177, Rev. B; Date: 26 Dec. 1951. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-3, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  6. River embankment characterization: The joint use of geophysical and geotechnical techniques

    NASA Astrophysics Data System (ADS)

    Perri, Maria Teresa; Boaga, Jacopo; Bersan, Silvia; Cassiani, Giorgio; Cola, Simonetta; Deiana, Rita; Simonini, Paolo; Patti, Salvatore

    2014-11-01

    Recent flood events in Northern Italy (particularly in the Veneto Region) have brought river embankments into the focus of public attention. Many of these embankments are more than 100 years old and have been repeatedly repaired, so that detailed information on their current structure is generally missing. The monitoring of these structures is currently based, for the most part, on visual inspection and localized measurements of the embankment material parameters. However, this monitoring is generally insufficient to ensure an adequate safety level against floods. For these reasons there is an increasing demand for fast and accurate investigation methods, such as geophysical techniques. These techniques can provide detailed information on the subsurface structures, are non-invasive, cost-effective, and faster than traditional methods. However, they need verification in order to provide reliable results, particularly in complex and reworked man-made structures such as embankments. In this paper we present a case study in which three different geophysical techniques have been applied: electrical resistivity tomography (ERT), frequency domain electromagnetic induction (FDEM) and Ground Penetrating Radar (GPR). Two test sites have been selected, both located in the Province of Venice (NE Italy) where the Tagliamento River has large embankments. The results obtained with these techniques have been calibrated against evidence resolving from geotechnical investigations. The pros and cons of each technique, as well as their relative merit at identifying the specific features of the embankments in this area, are highlighted. The results demonstrate that geophysical techniques can provide very valuable information for embankment characterization, provided that the data interpretation is constrained via direct evidence, albeit limited in space.

  7. Flood risk of natural and embanked landscapes on the Ganges-Brahmaputra tidal delta plain

    NASA Astrophysics Data System (ADS)

    Auerbach, L. W.; Goodbred, S. L., Jr.; Mondal, D. R.; Wilson, C. A.; Ahmed, K. R.; Roy, K.; Steckler, M. S.; Small, C.; Gilligan, J. M.; Ackerly, B. A.

    2015-02-01

    The Ganges-Brahmaputra river delta, with 170 million people and a vast, low-lying coastal plain, is perceived to be at great risk of increased flooding and submergence from sea-level rise. However, human alteration of the landscape can create similar risks to sea-level rise. Here, we report that islands in southwest Bangladesh, enclosed by embankments in the 1960s, have lost 1.0-1.5 m of elevation, whereas the neighbouring Sundarban mangrove forest has remained comparatively stable. We attribute this elevation loss to interruption of sedimentation inside the embankments, combined with accelerated compaction, removal of forest biomass, and a regionally increased tidal range. One major consequence of this elevation loss occurred in 2009 when the embankments of several large islands failed during Cyclone Aila, leaving large areas of land tidally inundated for up to two years until embankments were repaired. Despite sustained human suffering during this time, the newly reconnected landscape received tens of centimetres of tidally deposited sediment, equivalent to decades’ worth of normal sedimentation. Although many areas still lie well below mean high water and remain at risk of severe flooding, we conclude that elevation recovery may be possible through controlled embankment breaches.

  8. Case studies of geophysical imaging for road foundation design on soft soils and embankment risk assessment

    NASA Astrophysics Data System (ADS)

    Whiteley, Robert J.; Kelly, Richard B.; Stewart, Simon B.

    2015-12-01

    Population growth along the coast of eastern Australia has increased demand for new and upgraded transport infrastructure within intervening coastal floodplains and steeper hinterland areas. This has created additional challenges for road foundation design. The floodplain areas in this region are underlain by considerable thicknesses of recently deposited alluvial and clayey marine sediments. If characterisation of these deposits is inadequate they can increase road construction costs and affect long-term road stability and serviceability. Case studies from a major coastal highway upgrade demonstrate how combining surface wave seismic and electrical geophysical imaging with conventional geotechnical testing enhances characterisation of these very soft and soft soils. The geophysical results also provide initial foundation design parameters such as void ratio and pre-consolidation pressure. A further significant risk issue for roads is potential embankment instability. This can occur during new road construction or when upgrades of existing embankments are required. Assessing the causes of instability of existing steeper embankments with drilling and probing is often difficult and costly due to access and safety problems. In these situations combinations of electrical, ground penetrating radar and P-wave seismic imaging technologies can rapidly provide information on the likely conditions below both the roadway and embankment. Case studies show the application of these technologies on two unstable road embankments. It is concluded that the application of both geophysical imaging and geotechnical testing is a cost-effective enhancement for site characterisation of soft soils and for risk assessment of potentially unstable embankments. This approach overcomes many of the current limitations of conventional methods of site investigation that provide point location data only. The incorporation of geophysics into a well crafted site investigation allows concentration on

  9. Characteristics of dewatering induced drawdown curve under blocking effect of retaining wall in aquifer

    NASA Astrophysics Data System (ADS)

    Wu, Yong-Xia; Shen, Shui-Long; Yuan, Da-Jun

    2016-08-01

    For deep excavation pits that require the pumping of confined groundwater, a combination of a retaining wall and dewatering with large-diameter wells is usually adopted during excavation to improve safety. Since a retaining wall has a much lower hydraulic conductivity than the surrounding material in the aquifer, blocking of seepage to prolong the seepage path of the groundwater outside of the pit is effective. The retaining walls used during excavation dewatering cause hydraulic head drawdown inside the pit much faster than outside the pit. Thus, difference in hydraulic head between inside and outside of the pit increases. To investigate the mechanism of the blocking effect, numerical simulation using the finite difference method (FDM) was conducted to analyze the effects of pumping in the pit. The FDM results show that drawdown varies along the depth of the confined aquifer. The influence factors of drawdown inside and outside the pit include insertion depth of retaining walls, anisotropy of a confined aquifer and screen length of pumping wells. In addition, FDM results also show that the drawdown-time curve can be divided into four stages: in Stage I, drawdown inside the pit is very small and outside the pit it is almost zero; in Stage II, drawdown increases quickly with time; in Stage III, the drawdown curve is parallel to the Cooper-Jacob curve on semi-log axes; and in Stage IV, the drawdown becomes constant. These characteristics of the drawdown curve under the blocking effect of a retaining wall in an aquifer provide a way of estimating hydrogeological parameters according to pumping test results.

  10. Removal of river embankments and the modelled effects on river-floodplain hydrodynamics

    NASA Astrophysics Data System (ADS)

    Clilverd, Hannah; Thompson, Julian; Heppell, Kate; Sayer, Carl; Axmacher, Jan

    2015-04-01

    The channelization and embankment of rivers has led to major ecological degradation of aquatic habitats worldwide. River restoration, which often includes the removal of previously constructed barriers between a river and its floodplain, is now being widely used to create favourable hydrological conditions for target species or processes. However the effects of river restoration on hydraulic and hydrological processes are complex, and are often difficult to determine due to the infrequency of long-term monitoring programmes before and after restoration works. To examine the hydrological impacts of embankment removal under a variety of possible hydrological conditions, we developed coupled hydrological/hydraulic models of pre-embankment and post-embankment conditions at a wet grassland meadow in Norfolk, UK using the MIKE-SHE/MIKE 11 system. Groundwater hydrology and climate were monitored between 2007 and 2010 with river inflows being provided from an upstream gauging station. The embanked model was calibrated and validated with observed groundwater data for two consecutive 12-month periods, after which the restored topography was applied to the model and validated for a subsequent 12-month period. The restored model was then run for the same period as the embanked model (i.e. with the same river inflow, precipitation, and potential evapotranspiration data) to remove interannual climate variability and enable a direct comparison between models. Modelled groundwater levels compared well with piezometer observations and reproduced the observed rapid groundwater response to high magnitude rainfall and river flow events. Removal of the embankments resulted in frequent localised flooding at the river edge, widespread floodplain inundation at flows greater than 1.9 m3 sec-1, as well as higher groundwater levels and greater subsurface storage. Restoration had only a minor effect on flood peak attenuation (maximum 5% flood peak reduction), likely due to the small size of

  11. Active and passive electrical and seismic time-lapse monitoring of earthen embankments

    NASA Astrophysics Data System (ADS)

    Rittgers, Justin Bradley

    In this dissertation, I present research involving the application of active and passive geophysical data collection, data assimilation, and inverse modeling for the purpose of earthen embankment infrastructure assessment. Throughout the dissertation, I identify several data characteristics, and several challenges intrinsic to characterization and imaging of earthen embankments and anomalous seepage phenomena, from both a static and time-lapse geophysical monitoring perspective. I begin with the presentation of a field study conducted on a seeping earthen dam, involving static and independent inversions of active tomography data sets, and self-potential modeling of fluid flow within a confined aquifer. Additionally, I present results of active and passive time-lapse geophysical monitoring conducted during two meso-scale laboratory experiments involving the failure and self-healing of embankment filter materials via induced vertical cracking. Identified data signatures and trends, as well as 4D inversion results, are discussed as an underlying motivation for conducting subsequent research. Next, I present a new 4D acoustic emissions source localization algorithm that is applied to passive seismic monitoring data collected during a full-scale embankment failure test. Acoustic emissions localization results are then used to help spatially constrain 4D inversion of collocated self-potential monitoring data. I then turn to time-lapse joint inversion of active tomographic data sets applied to the characterization and monitoring of earthen embankments. Here, I develop a new technique for applying spatiotemporally varying structural joint inversion constraints. The new technique, referred to as Automatic Joint Constraints (AJC), is first demonstrated on a synthetic 2D joint model space, and is then applied to real geophysical monitoring data sets collected during a full-scale earthen embankment piping-failure test. Finally, I discuss some non-technical issues related to

  12. View of McKenzieRichey stone retaining wall. View from the north ...

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

    View of McKenzie-Richey stone retaining wall. View from the north fence facing south - McKenzie Property, Retaining Wall, North Bank of Sailor Gulch, 750 feet northwest of intersection of U.S.F.S. Roads 651 & 349, Placerville, Boise County, ID

  13. View of McKenzieRichey retaining wall. View from the yard facing ...

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

    View of McKenzie-Richey retaining wall. View from the yard facing northeast. Note the garage in the background - McKenzie Property, Retaining Wall, North Bank of Sailor Gulch, 750 feet northwest of intersection of U.S.F.S. Roads 651 & 349, Placerville, Boise County, ID

  14. Erodibility characteristics of embankment materials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Erosion is one of the least reliably defined elements of many hydraulic projects. Earthen embankments (i.e. dams and levees) are an example of hydraulic projects in which erosion and material erodibility have not been reliably defined in the past. Recent as well as past embankment failures have he...

  15. Subsurface imaging of flood embankment erosional-piping collapse using a combined MASW and ERI approach

    NASA Astrophysics Data System (ADS)

    Brook, Martin

    2016-04-01

    In recent years, non-destructive investigations and management of civil engineering structures is increasingly improving, and assessments are now supported by national and international standards. However, the literature on the applicability of different geophysical techniques to the problem of levee and river embankment monitoring is still limited. Accurate flood levee embankment stability assessment is critically important because embankments and earth dams are subject to water infiltration and internal erosion, which may lead to mechanical weakness and breaching. This study includes a 2D analysis of the instability of an earthen levee, using multichannel analysis of surface waves (MASW) and electrical resistivity imaging (ERI), along with direct observations of the site engineering geology and geomorphology. Both the modeled Vs and Ω indicate a horizontally-layered subsurface with rapid vertical transitions in both stiffness and conductivity. This conclusion is supported by a covariance analysis of Vs and Ω at varying depths and chainages along the levee. Together with a geomorphic assessment, this indicates that the structure is being destabilized by water infiltration, which is causing erosional-piping, leading to surface subsidence. While the key reason for applying various types of geophysical methods to embankment stability assessment is to undertake a safety examination of the embankment, a secondary reason is to compare and contrast the efficacy of the geophysical methods. To this end, it was found that the integration of covariance analysis of 2D geophysical datasets, alongside sedimentary and topographic data, can help the rapid location of anomalous zones in sub-levee soils between geotechnical boreholes.

  16. Retain Who and Why.

    ERIC Educational Resources Information Center

    Osborne, V. Con; And Others

    While the number of minority students in postsecondary education has climbed since 1970, the rates of minority graduation are still too low. Factors adding to the dropout rate include: inadequate finances, poor academic preparation, low motivation, poor study habits, low basic skills, and low institutional support. This paper describes support…

  17. Earthen embankment erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A large number of embankment structures, including dams, levees, dikes, and barriers, have been built by humans or formed naturally along rivers, lakes, and coastal lines around the world. These structures play very important roles in flood defense, while many are also used for water supply, power g...

  18. Earthen embankment breaching

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A large number of embankment structures, including dams, levees, dikes, and barriers, have been built by humans. These structures play a very important role in flood defense, while many are also used for water supply, power generation, transportation, sediment retention, etc. Since these structure...

  19. 2. RETAINING WALL, NORTHEAST VIEW (1992). WrightPatterson Air Force ...

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

    2. RETAINING WALL, NORTHEAST VIEW (1992). - Wright-Patterson Air Force Base, Area B, Building 71, Power Plant Engine Test Torque Stands, Seventh Street between D & G Streets, Dayton, Montgomery County, OH

  20. 3. RETAINING WALL, NORTHEAST VIEW (1992). WrightPatterson Air Force ...

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

    3. RETAINING WALL, NORTHEAST VIEW (1992). - Wright-Patterson Air Force Base, Area B, Building 71, Power Plant Engine Test Torque Stands, Seventh Street between D & G Streets, Dayton, Montgomery County, OH

  1. 6. RETAINING WALLS, NORTHEAST VIEW (1992). WrightPatterson Air Force ...

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

    6. RETAINING WALLS, NORTHEAST VIEW (1992). - Wright-Patterson Air Force Base, Area B, Building 71, Power Plant Engine Test Torque Stands, Seventh Street between D & G Streets, Dayton, Montgomery County, OH

  2. 4. RETAINING WALL, NORTHEAST VIEW (1992). WrightPatterson Air Force ...

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

    4. RETAINING WALL, NORTHEAST VIEW (1992). - Wright-Patterson Air Force Base, Area B, Building 71, Power Plant Engine Test Torque Stands, Seventh Street between D & G Streets, Dayton, Montgomery County, OH

  3. Railway cuttings and embankments: Experimental and numerical studies of ground vibration.

    PubMed

    Kouroussis, Georges; Connolly, David P; Olivier, Bryan; Laghrouche, Omar; Costa, Pedro Alves

    2016-07-01

    Railway track support conditions affect ground-borne vibration generation and propagation. Therefore this paper presents a combined experimental and numerical study into high speed rail vibrations for tracks on three types of support: a cutting, an embankment and an at grade section. Firstly, an experimental campaign is undertaken where vibrations and in-situ soil properties are measured at three Belgian rail sites. A finite element model is then developed to recreate the complex ground topology at each site. A validation is performed and it is found that although the at-grade and embankment cases show a correlation with the experimental results, the cutting case is more challenging to replicate. Despite this, each site is then analysed to determine the effect of earthworks profile on ground vibrations, with both the near and far fields being investigated. It is found that different earthwork profiles generate strongly differing ground-borne vibration characteristics, with the embankment profile generating lower vibration levels in comparison to the cutting and at-grade cases. Therefore it is concluded that it is important to consider earthwork profiles when undertaking vibration assessments. PMID:26994799

  4. Material Characteristics of Clinker Ash and Examination of Applicability for Embankment

    NASA Astrophysics Data System (ADS)

    Wakatsuki, Yoshitaka; Hyodo, Masayuki; Yoshimoto, Norimasa; Nakashita, Akifumi; Ikeda, Takashi

    2009-06-01

    The clinker ash is a coal ash generated by the coal-fired power station. It is characterized by its lightweight particle with asperity due to foaming during production process resulted in high shear stiffness and strength and high permeability. It is, therefore, increasingly used for the embankment material, the base course material, and the drainage material. Moreover, the application has started to be investigated for the vertical drain method and the compaction pile method. However, the physical characteristics and the mechanical characteristics of clinker ash have not been understood yet. It is expected that the stock yard for coal ashes will be insufficient as production of the coal ash will increase. It is necessary to use the coal ash more to maintain the global environment. The design parameter for clinker ash to apply to the embankment material was experimentally investigated in this research.

  5. Recruiting and Retaining Summer Staff.

    ERIC Educational Resources Information Center

    Crossen, Brian; Yerkes, Rita

    1998-01-01

    Recruiting of camp staff is challenged by economic and workplace restructuring, including business downsizing, part-time and temporary employment patterns, and generational attitude changes. Strategies for hiring and retaining staff include knowing what college-age workers want, marketing benefits, adopting new business strategies, and empowering…

  6. Spreading Topsoil Encourages Ecological Restoration on Embankments: Soil Fertility, Microbial Activity and Vegetation Cover

    PubMed Central

    Rivera, Desirée; Mejías, Violeta; Jáuregui, Berta M.; López-Archilla, Ana Isabel; Peco, Begoña

    2014-01-01

    The construction of linear transport infrastructure has severe effects on ecosystem functions and properties, and the restoration of the associated roadslopes contributes to reduce its impact. This restoration is usually approached from the perspective of plant cover regeneration, ignoring plant-soil interactions and the consequences for plant growth. The addition of a 30 cm layer of topsoil is a common practice in roadslope restoration projects to increase vegetation recovery. However topsoil is a scarce resource. This study assesses the effects of topsoil spreading and its depth (10 to 30 cm) on two surrogates of microbial activity (β-glucosidase and phosphatase enzymes activity and soil respiration), and on plant cover, plant species richness and floristic composition of embankment vegetation. The study also evaluates the differences in selected physic-chemical properties related to soil fertility between topsoil and the original embankment substrate. Topsoil was found to have higher values of organic matter (11%), nitrogen (44%), assimilable phosphorous (50%) and silt content (54%) than the original embankment substrate. The topsoil spreading treatment increased microbial activity, and its application increased β-glucosidase activity (45%), phosphatase activity (57%) and soil respiration (60%). Depth seemed to affect soil respiration, β-glucosidase and phosphatase activity. Topsoil application also enhanced the species richness of restored embankments in relation to controls. Nevertheless, the depth of the spread topsoil did not significantly affect the resulting plant cover, species richness or floristic composition, suggesting that both depths could have similar effects on short-term recovery of the vegetation cover. A significant implication of these results is that it permits the application of thinner topsoil layers, with major savings in this scarce resource during the subsequent slope restoration work, but the quality of topsoil relative to the

  7. Recruiting and Retaining Adult Students.

    ERIC Educational Resources Information Center

    Hadfield, Janice

    2003-01-01

    Adult learners, long the stepchildren of colleges and universities, have nearly become the norm, and they spend billions of dollars each year on education. This chapter takes a customer-oriented approach to recruiting and retaining adult students in higher education. (GCP)

  8. Dynamic response of a pair of walls retaining a viscoelastic solid

    SciTech Connect

    Veletsos, A.S.; Parikh, V.H.; Younan, A.H.; Bandyopadhyay, K.

    1995-01-01

    Making use of a previously reported, simple, approximate method of analysis, a critical evaluation is made of the dynamic pressures and forces induced by horizontal ground shaking on a pair of infinitely long, parallel walls retaining a uniform viscoelastic solid. The walls are presumed to be rigid but elastically constrained against rotation at their base. The effects of both harmonic and earthquake-induced excitations are examined. The accuracy of the method is assessed by comparing its predictions for the special case of fixed-based walls with those obtained by an exact method, and comprehensive numerical data are presented which elucidate the underlying response mechanisms, and the effects and relative importance of the parameters involved. The parameters examined include the characteristics of the ground motion, the ratio of the distance between walls to the height of the contained material, and the flexibility of the rotational wall constraints. In addition to valuable insights into the responses of the systems investigated, the results presented provide a convenient framework for the analysis of more complex systems as well.

  9. Soil erosion on road and railways embankments in the Canyoles river Basin. Eastern Spain.

    NASA Astrophysics Data System (ADS)

    Cerdà, Artemi; Antonio, Giménez-Morera; Félix Ángel, González-Peñaloza; María, Burguet; Paulo, Pereira; José Reyes, Ruiz

    2013-04-01

    Mediterranean landscapes are man-made. Its human ecosystems are characterized by a high population density, a long history of human settlement and an intense exchange of goods and people (Cerdà et al., 2010). This was possible due to a dense road network, most of it created during the Roman Empire. Modern roads and railways increased drastically during the last 30 years in the Mediterranean. Spain is a clear example of the acceleration of the road and railway infrastructures (Bel, 2005), especially during the 1960s as the tourism started to become a big issue in this part of the World. The increase in road and railways during the last 30 years resulted in a new transport system in Spain, which is based on high-speed railways and motorways. The characteristic of these infrastructures is that they were built by means of embankments, and little is now about the erosional response of those embankments to rainfall. The objective of this research is to assess the soil losses measured in road and railway embankments. The Canyoles River watershed was selected as an example of a region with a dense and recently developed modern network of roads, motorways and railway. The Canyoles river watershed is the natural path between the Mediterranean coast and Central Spain, the capital of the country and the touristic regions. Two motorways and two railways were built or re-built during the last two years and this paper assesses their impact on soil and water losses. As soil erosion rates are dependent on the high intensity - low frequency rainfall events, rainfall simulation experiments (40 experiments) were conducted (1 m2 plots; 60 minutes duration; 78 mm h-1 intensity) were carried out over plots on 2 railway (n=10 + 10) and motorway (n=10 + 10) research sites in August 2011, under very dry conditions. Soil moisture was below 5 % in the top 2 cm soil layer. The vegetation cover was very low in the two road and two railway embankments as the average cover was 4.2 % ranging from

  10. Soil erosion on road and railways embankments in the Canyoles river Basin. Eastern Spain.

    NASA Astrophysics Data System (ADS)

    Cerdà, Artemi; Antonio, Giménez-Morera; Félix Ángel, González-Peñaloza; María, Burguet; Paulo, Pereira; José Reyes, Ruiz

    2013-04-01

    Mediterranean landscapes are man-made. Its human ecosystems are characterized by a high population density, a long history of human settlement and an intense exchange of goods and people (Cerdà et al., 2010). This was possible due to a dense road network, most of it created during the Roman Empire. Modern roads and railways increased drastically during the last 30 years in the Mediterranean. Spain is a clear example of the acceleration of the road and railway infrastructures (Bel, 2005), especially during the 1960s as the tourism started to become a big issue in this part of the World. The increase in road and railways during the last 30 years resulted in a new transport system in Spain, which is based on high-speed railways and motorways. The characteristic of these infrastructures is that they were built by means of embankments, and little is now about the erosional response of those embankments to rainfall. The objective of this research is to assess the soil losses measured in road and railway embankments. The Canyoles River watershed was selected as an example of a region with a dense and recently developed modern network of roads, motorways and railway. The Canyoles river watershed is the natural path between the Mediterranean coast and Central Spain, the capital of the country and the touristic regions. Two motorways and two railways were built or re-built during the last two years and this paper assesses their impact on soil and water losses. As soil erosion rates are dependent on the high intensity - low frequency rainfall events, rainfall simulation experiments (40 experiments) were conducted (1 m2 plots; 60 minutes duration; 78 mm h-1 intensity) were carried out over plots on 2 railway (n=10 + 10) and motorway (n=10 + 10) research sites in August 2011, under very dry conditions. Soil moisture was below 5 % in the top 2 cm soil layer. The vegetation cover was very low in the two road and two railway embankments as the average cover was 4.2 % ranging from

  11. Particle Clogging in Filter Media of Embankment Dams: A Numerical and Experimental Study

    NASA Astrophysics Data System (ADS)

    Antoun, T.; Kanarska, Y.; Ezzedine, S. M.; Lomov, I.; Glascoe, L. G.; Smith, J.; Hall, R. L.; Woodson, S. C.

    2013-12-01

    The safety of dam structures requires the characterization of the granular filter ability to capture fine-soil particles and prevent erosion failure in the event of an interfacial dislocation. Granular filters are one of the most important protective design elements of large embankment dams. In case of cracking and erosion, if the filter is capable of retaining the eroded fine particles, then the crack will seal and the dam safety will be ensured. Here we develop and apply a numerical tool to thoroughly investigate the migration of fines in granular filters at the grain scale. The numerical code solves the incompressible Navier-Stokes equations and uses a Lagrange multiplier technique which enforces the correct in-domain computational boundary conditions inside and on the boundary of the particles. The numerical code is validated to experiments conducted at the US Army Corps of Engineering and Research Development Center (ERDC). These laboratory experiments on soil transport and trapping in granular media are performed in constant-head flow chamber filled with the filter media. Numerical solutions are compared to experimentally measured flow rates, pressure changes and base particle distributions in the filter layer and show good qualitative and quantitative agreement. To further the understanding of the soil transport in granular filters, we investigated the sensitivity of the particle clogging mechanism to various parameters such as particle size ratio, the magnitude of hydraulic gradient, particle concentration, and grain-to-grain contact properties. We found that for intermediate particle size ratios, the high flow rates and low friction lead to deeper intrusion (or erosion) depths. We also found that the damage tends to be shallower and less severe with decreasing flow rate, increasing friction and concentration of suspended particles. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under

  12. UMTRA Project value engineering plan. [Design and construction of stabilized tailings embankments

    SciTech Connect

    Not Available

    1990-06-01

    The objective of value engineering (VE) on the Uranium MILL Tailings Remedial Action (UMTRA) Project is to ensure that remedial action at the UMTRA Project sites is performed to meet the US Environmental Protection Agency (EPA) standards for inactive uranium mill tailings sites at the lowest cost, while maintaining a high quality of work. Through review of designs and consideration of reasonable, less expensive alternatives, VE can be an effective cost reduction tool and a means to improve the design. The UMTRA Project products are the design and construction of stabilized tailings embankments.

  13. 4. OVERVIEW TO EAST, FROM WEST END OF EARTHEN EMBANKMENT, ...

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

    4. OVERVIEW TO EAST, FROM WEST END OF EARTHEN EMBANKMENT, SHOWING DOWNSTREAM FACE OF DAM, AND SPILLWAY FACE IN DISTANCE AT UPPER RIGHT. - Prado Dam, Embankment, Santa Ana River near junction of State Highways 71 & 91, Corona, Riverside County, CA

  14. Piled Embankment Design Comparison

    NASA Astrophysics Data System (ADS)

    Drusa, Marián; Kais, Ladislav; Vlček, Jozef; Mečár, Martin

    2015-05-01

    There are currently several national standards or regulations for the design of the piled embankment, providing suitable solutions for foundation of transport structure on soft, high compressible subsoil, [1]. The most widely used and the best-known standard is British Standard BS8006 [2], which was confronted with another analytical design methodologies (Ebgeo, CUR). Today's popularity and versatility of FEM numerical models brings many advantages, which analytical methods cannot achieved, but must be verified by proposed scaled physical model, which was currently being developed by Department of Geotechnics, University of Žilina.

  15. Geotechnical properties of fly and bottom ash mixtures for use in highway embankments

    SciTech Connect

    Kim, B.; Prezzi, M.; Salgado, R.

    2005-07-01

    Class F fly ash and bottom ash are the solid residue byproducts produced by coal-burning electric utilities. They are usually disposed of together as a waste in utility disposal sites with a typical disposal rate of 80% fly ash and 20% bottom ash. Direct use of these materials in construction projects consuming large volumes of materials, such as highway embankment construction, not only provides a promising solution to the disposal problem, but also an economic alternative to the use of traditional materials. Representative samples of class F fly and bottom ash were collected from two utility power plants in Indiana and tested for their mechanical properties (compaction, permeability, strength, stiffness, and compressibility). Three mixtures of fly and bottom ash with different mixture ratios (i.e., 50, 75, and 100% fly ash content by weight) were prepared for testing. Test results indicated that ash mixtures compare favorably with conventional granular materials.

  16. Monitoring Coastal Embankment Subsidence and Relative Sea Level Rise in Coastal Bangladesh Using Satellite Geodetic Data

    NASA Astrophysics Data System (ADS)

    Guo, Q.; Shum, C. K.; Jia, Y.; Yi, Y.; Zhu, K.; Kuo, C. Y.; Liibusk, A.

    2015-12-01

    The Bangladesh Delta is located at the confluence of the mega Ganges, Brahmaputra and Meghan Rivers in the Bay of Bengal. It is home to over 160 million people and is one of the most densely populated countries in the world. It is prone to seasonal transboundary monsoonal flooding, potentially aggravated by more frequent and intensified cyclones resulting from anthropogenic climate change. Sea level rise, along with tectonic, sediment compaction/load and groundwater extraction induced land uplift/subsidence, have significantly exacerbated these risks and Bangladesh's coastal vulnerability. Bangladesh has built 123 coastal embankments or polders since the 1960's, to protect the coastal regions from cyclone/tidal flooding and to reduce salinity incursions. Since then, many coastal polders have suffered severe erosion and anthropogenic damage, and require repairs or rebuilding. However, the physical and anthropogenic processes governing the historic relative sea level rise and its future projection towards its quantification remain poorly understood or known, and at present not accurate enough or with an adequately fine local spatial scale for practical mitigation of coastal vulnerability or coastal resilience studies. This study reports on our work in progress to use satellite geodetic and remote sensing observations, including satellite radar altimetry/backscatter measurements over land and in coastal oceans, optical/infrared imageries, and SAR backscatter/InSAR data, to study the feasibility of coastal embankment/polder erosion monitoring, quantify seasonal polder water intrusions, observing polder subsidence, and finally, towards the goal of improving the relative sea level rise hazards assessment at the local scale in coastal Bangladesh.

  17. Losses of surface runoff, total solids, and nitrogen during bermudagrass establishment on levee embankments.

    PubMed

    Burwell, Robert W; Beasley, Jeffrey S; Gaston, Lewis A; Borst, Steven M; Sheffield, Ron E; Strahan, Ron E; Munshaw, Gregg C

    2011-01-01

    Nutrient and sediment runoff from newly constructed levee embankments pose a threat to water quality during soft armor vegetation establishment. Research was initiated in 2008 and 2009 to evaluate the effect of bermudagrass ( L.) coverage and N source on nutrient and sediment runoff from levee embankments during establishment. Bermudagrass plots were seeded at 195.3 kg pure live seed ha and fertilized at 50 kg N ha using a water-soluble N source, urea or NH-NO, or slow-release N source, S-coated urea (SCU) or urea formaldehyde (UF), with controls unfertilized. Vegetative cover percentage, time until the onset of runoff, runoff volume, and total solids (TS), NO-N, and NH-N concentrations were measured from simulated and natural rainfall events for 70 d in 2008 and 56 d in 2009. Bermudagrass at 90% grass cover delayed the onset of runoff an additional 441 to 538 s and reduced runoff volumes 74 to 84% of that exhibited at 10% grass cover. Nitrogen fertilizers did not accelerate bermudagrass growth sufficiently, however, to reduce TS loading compared with unfertilized bermudagrass in either year of the study. The application of urea and SCU resulted in cumulative N losses of 2.45 and 3.13 kg ha compared with 1.59 kg ha from the unfertilized bermudagrass in 2008, and 1.73 kg ha from NH-NO vs. 0.24 kg ha from controls in 2009. Only UF increased bermudagrass establishment without increasing cumulative N losses compared with unfertilized bermudagrass. Therefore, the benefit of greater erosion and runoff resistance expected from N-accelerated vegetative growth did not occur but had the unintended consequence of higher N losses when water-soluble N and SCU fertilizers were applied. PMID:21712593

  18. The protective and attractive covering of a vegetated embankment using coir geotextiles

    NASA Astrophysics Data System (ADS)

    Vishnudas, S.; Savenije, H. H. G.; van der Zaag, P.; Anil, K. R.; Balan, K.

    2006-08-01

    This paper presents the results of a field experiment conducted in Kerala, South India, to test the effectiveness of coir geotextiles for embankment protection. The results reveal that treatment with geotextile in combination with grass is an effective eco-hydrological measure to protect steep slopes from erosion. In the context of sustainable watershed management, coir is a cheap and locally available material that can be used to strengthen traditional earthen bunds or protect the banks of village ponds from erosion. Particularly in developing countries, where coir is abundantly available and textiles can be produced by small-scale industry, this is an attractive alternative for conventional methods. This paper analyses the performance of coir geotextile in different treatments with respect to soil moisture content, protection against erosion and biomass production.

  19. Bridge Structure, Foundation and Approach Embankment Performance for the October-November 2002 Earthquake Sequence on the Denali Fault, Alaska

    NASA Astrophysics Data System (ADS)

    Vinson, T. S.; Hulsey, L.; Ma, J.; Connor, B.; Brooks, T. E.

    2002-12-01

    More than two dozen major bridges were subjected to severe ground motions during the October-November 2002 Earthquake Sequence on the Denali Fault, Alaska. The bridges represented a number of conventional designs constructed over the past three to four decades. The objective of the field investigation presented herein was to determine the extent of the damage, if any, to the bridge structures, foundations and approach embankments. This was accomplished by direct inspection of the bridges by the authors (or employees of their organizations) along the Richardson, Alaska, Parks, and Denali Highways, the Tok Cutoff, and the railroad bridges for the railroad alignment between Trapper Creek and Fairbanks. More specifically, the members of the investigation team (represented by the authors) conducted more than three days of field inspections of bridges within the zone of severe ground shaking during the M6.7 and M7.9 Denali fault events. The primary conclusion noted was that while a substantial number of bridges were subjected to intense shaking they all performed very well and were not damaged to the extent that remedial repairs to the bridge structure were necessary. There were occurrences of lateral spreading/liquefaction related damage to the approach embankments and slight separation of the approach embankment from the abutment foundation systems. Overall, considering the severity of ground shaking, much greater damage to the bridge structures, foundations and approach embankments would be predicted. Had the earthquakes occurred during winter when the ground was frozen and the ductility of the structures was substantially reduced events comparable to the October-November 2002 Earthquake Sequence on the Denali Fault, Alaska could have resulted in significant damage to bridges. This reconnaissance was supported by the National Science Foundation, Alaska Dept. of Transportation and Public Facilities, and the Alaska Railroad Corporation.

  20. Modeling of hydrologic conditions and solute movement in processed oil shale waste embankments under simulated climatic conditions

    SciTech Connect

    Reeves, T.L.; Turner, J.P.; Hasfurther, V.R.; Skinner, Q.D.

    1992-06-01

    The scope of this program is to study interacting hydrologic, geotechnical, and chemical factors affecting the behavior and disposal of combusted processed oil shale. The research combines bench-scale testing with large scale research sufficient to describe commercial scale embankment behavior. The large scale approach was accomplished by establishing five lysimeters, each 7.3 {times} 3.0 {times} 3.0 m deep, filled with processed oil shale that has been retorted and combusted by the Lurgi-Ruhrgas (Lurgi) process. Approximately 400 tons of Lurgi processed oil shale waste was provided by RBOSC to carry out this study. Research objectives were designed to evaluate hydrologic, geotechnical, and chemical properties and conditions which would affect the design and performance of large-scale embankments. The objectives of this research are: assess the unsaturated movement and redistribution of water and the development of potential saturated zones and drainage in disposed processed oil shale under natural and simulated climatic conditions; assess the unsaturated movement of solubles and major chemical constituents in disposed processed oil shale under natural and simulated climatic conditions; assess the physical and constitutive properties of the processed oil shale and determine potential changes in these properties caused by disposal and weathering by natural and simulated climatic conditions; assess the use of previously developed computer model(s) to describe the infiltration, unsaturated movement, redistribution, and drainage of water in disposed processed oil shale; evaluate the stability of field scale processed oil shale solid waste embankments using computer models.

  1. Modeling of hydrologic conditions and solute movement in processed oil shale waste embankments under simulated climatic conditions

    SciTech Connect

    Reeves, T.L.; Turner, J.P.; Hasfurther, V.R.; Skinner, Q.D.

    1992-06-01

    The scope of this program is to study interacting hydrologic, geotechnical, and chemical factors affecting the behavior and disposal of combusted processed oil shale. The research combines bench-scale testing with large scale research sufficient to describe commercial scale embankment behavior. The large scale approach was accomplished by establishing five lysimeters, each 7.3 [times] 3.0 [times] 3.0 m deep, filled with processed oil shale that has been retorted and combusted by the Lurgi-Ruhrgas (Lurgi) process. Approximately 400 tons of Lurgi processed oil shale waste was provided by RBOSC to carry out this study. Research objectives were designed to evaluate hydrologic, geotechnical, and chemical properties and conditions which would affect the design and performance of large-scale embankments. The objectives of this research are: assess the unsaturated movement and redistribution of water and the development of potential saturated zones and drainage in disposed processed oil shale under natural and simulated climatic conditions; assess the unsaturated movement of solubles and major chemical constituents in disposed processed oil shale under natural and simulated climatic conditions; assess the physical and constitutive properties of the processed oil shale and determine potential changes in these properties caused by disposal and weathering by natural and simulated climatic conditions; assess the use of previously developed computer model(s) to describe the infiltration, unsaturated movement, redistribution, and drainage of water in disposed processed oil shale; evaluate the stability of field scale processed oil shale solid waste embankments using computer models.

  2. Attracting and retaining nurses in HIV care.

    PubMed

    Puplampu, Gideon L; Olson, Karin; Ogilvie, Linda; Mayan, Maria

    2014-01-01

    Attracting and retaining nurses in HIV care is essential to treatment success, preventing the spread of HIV, slowing its progression, and improving the quality of life of people living with HIV. Despite the wealth of studies examining HIV care, few have focused on the factors that influenced nurses' choices to specialize in HIV care. We examined the factors that attracted and retained eight nurses currently working in HIV care in two large Canadian cities. Participants were primarily women between the ages of 20 and 60 years. Interviews were conducted between November 2010 and September 2011 using interpretive description, a qualitative design. Factors that influenced participants to focus their careers in HIV care included both attracting factors and retaining factors. Although more research is needed, this exploration of attracting and retaining factors may motivate others to specialize in HIV nursing, and thus help to promote adequate support for individuals suffering from the disease. PMID:23499392

  3. Stabilization Columns for Embankment Support - Investigation, Verification and Further Development of Analytical Analyses

    NASA Astrophysics Data System (ADS)

    Pankrath, H.; Kaya, H.; Thiele, R.

    2015-09-01

    As a technical and economical alternative to foundations on piles, but also to shallow foundations on improved soil, in recent decades a high number of soil improvement methods have been developed and established. Many of these methods use non-reinforced, cylindrical load bearing elements. A very common application of stabilizing columns is the improvement of a few meters thick soft soils below dams and embankments. But especially for this application, many failure cases are documented worldwide. In the contribution the substantial content and results are presented for investigation, testing and further development of methods for evaluating the slope stability. After a description of the problem and consequential tasks the contribution contains main results of the investigations of international sources with the stepwise development of analytical solutions. Next to the in practice well- known approaches for gravel columns, less common approaches from Scandinavia are explained. The contribution is completed with a presentation and discussion of an illustrative example, taking into account a number of different failure modes of the columns and the surrounding soil. The example was compared and validated with a 3D Model using the Finite Element Method.

  4. Recruiting and Retaining High Achievers

    ERIC Educational Resources Information Center

    Greco, Ben

    1977-01-01

    That elite portion of candidates--the ones with brains, talent, and ambition--are a valuable asset for a company only when they can be successfully hired and utilized. This article tells how. (Author)

  5. Stragegies for Attracting and Retaining Teachers

    ERIC Educational Resources Information Center

    Bland, Paul; Church, Edwin; Luo, Mingchu

    2014-01-01

    Attracting and retaining high quality teachers is a challenge for many school districts. This is especially true in a time of increased accountability and limited resources. This report details best practice in the training, hiring, improvement, and retention of high quality teaching staff. The authors explain how school leaders can attract…

  6. Selecting and Retaining Teacher Mentors. ERIC Digest.

    ERIC Educational Resources Information Center

    Mullinix, Bonnie B.

    This digest examines considerations and strategies for selecting and retaining teacher mentors, suggesting that the degree to which mentors are meaningfully engaged in the mentoring process may have a significant impact on a program's success. Strategies for recruiting mentors range from opportunistic appointment to promoting self-nomination to…

  7. Retained Gas Sampler Calibration and Simulant Tests

    SciTech Connect

    CRAWFORD, B.A.

    2000-01-05

    This test plan provides a method for calibration of the retained gas sampler (RGS) for ammonia gas analysis. Simulant solutions of ammonium hydroxide at known concentrations will be diluted with isotopically labeled 0.04 M ammonium hydroxide solution. Sea sand solids will also be mixed with ammonium hydroxide solution and diluent to determine the accuracy of the system for ammonia gas analysis.

  8. Recruiting, Retaining, and Fairly Compensating Our Teachers

    ERIC Educational Resources Information Center

    Lynch, Matthew

    2012-01-01

    This article examines three interlinked problems facing public schools today: how to recruit, retain, and pay our teachers. The article begins with an overview of the current situation in the United States, paying particular attention to schools in areas where minorities are the majority. It goes on to examine some of the causes of teacher…

  9. Embankment erosion process model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA, Agricultural Research Service (ARS) Hydraulic Engineering Research Unit (HERU) laboratory’s conducts research in support of the USDA NRCS Small Watershed Program by addressing dam safety issues. This presentation describes research on improving methods for predicting earthen embankment er...

  10. Retaining African Americans in Higher Education: Challenging Paradigms for Retaining Students, Faculty and Administrators.

    ERIC Educational Resources Information Center

    Jones, Lee, Ed.

    This collection discusses some of the issues surrounding the retention of African Americans in higher education, and it challenges traditional paradigms for retaining African American students, administrators, and faculty at predominantly White colleges. The chapters of part 1, "Retaining African-American Students," are: (1) "Creating an Affirming…

  11. Discussion of "Aeration, flow instabilities, and residual energy on pooled stepped spillways of embankment dams" by Stephen Felder and Hubert Chanson

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stepped spillways applied to embankment dams provide overtopping protection and address a common deficiency in aging dams by providing increased spillway capacity. Pooled-stepped spillways offer a design alternative to the traditional flat-stepped spillways. Researchers from the University of Quee...

  12. Autofrettage: Stress distribution under load and retained stresses after depressurization

    NASA Astrophysics Data System (ADS)

    Avitzur, Boaz

    1992-07-01

    There is a long-standing interest in developing a capability to predict the distribution of retained stresses in thick-walled tubes after the removal of an internal pressure-post autofrettage. In this report, four different methods of calculating such stresses are presented and compared. The methods presented are based on the following assumed yield criteria and deformation conditions: (1) Tresca's yield criterion; (2) Tresca's yield criterion 2/3; (3) Mises' yield criterion in plane-stress; and (4) Mises' yield criterion in plane-strain.

  13. WinDAM C earthen embankment internal erosion analysis software

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two primary causes of dam failure are overtopping and internal erosion. For the purpose of evaluating dam safety for existing earthen embankment dams and proposed earthen embankment dams, Windows Dam Analysis Modules C (WinDAM C) software will simulate either internal erosion or erosion resulting f...

  14. Development of CCHE2D embankment break model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Earthen embankment breach often results in detrimental impact on downstream residents and infrastructure, especially those located in the flooding zone. Embankment failures are most commonly caused by overtopping or internal erosion. This study is to develop a practical numerical model for simulat...

  15. Development of CCHE2D embankment break model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flooding due to breaching of earth embankments often results in detrimental impact on the people and their properties in the flooding zone. The embankment breaching process is often caused by overtopping of excessive water in a reservoir or a river. This study is to develop a practical numerical m...

  16. Apparatus and Process for Controlled Nanomanufacturing Using Catalyst Retaining Structures

    NASA Technical Reports Server (NTRS)

    Nguyen, Cattien (Inventor)

    2013-01-01

    An apparatus and method for the controlled fabrication of nanostructures using catalyst retaining structures is disclosed. The apparatus includes one or more modified force microscopes having a nanotube attached to the tip portion of the microscopes. An electric current is passed from the nanotube to a catalyst layer of a substrate, thereby causing a localized chemical reaction to occur in a resist layer adjacent the catalyst layer. The region of the resist layer where the chemical reaction occurred is etched, thereby exposing a catalyst particle or particles in the catalyst layer surrounded by a wall of unetched resist material. Subsequent chemical vapor deposition causes growth of a nanostructure to occur upward through the wall of unetched resist material having controlled characteristics of height and diameter and, for parallel systems, number density.

  17. Real-scale investigation of the kinematic response of a rockfall protection embankment

    NASA Astrophysics Data System (ADS)

    Lambert, S.; Heymann, A.; Gotteland, P.; Nicot, F.

    2014-01-01

    This paper addresses the response of rockfall protection embankments when exposed to a rock impact. For this purpose, real-scale impact experiments were conducted with impact energies ranging from 200 to 2200 kJ. The structure was composed of a 4 m-high cellular wall leaned against a levee. The wall was a double-layer sandwich made from gabion cages filled with either stones or a sand-scrapped tyre mixture. For the first time, sensors were placed in different locations within the structure to measure real-time accelerations and displacements. The test conditions, measurement methods and results are presented in detail. The structure's response is discussed in a descriptive and phenomenological approach and compared with previous real-scale experiments on other types of embankments.

  18. Real-scale investigation of the kinematic response of a rockfall protection embankment

    NASA Astrophysics Data System (ADS)

    Lambert, S.; Heymann, A.; Gotteland, P.; Nicot, F.

    2014-05-01

    This paper addresses the response of rockfall protection embankments when exposed to a rock impact. For this purpose, real-scale impact experiments were conducted with impact energies ranging from 200 to 2200 kJ. The structure was composed of a 4 m high cellular wall leaned against a levee. The wall was a double-layer sandwich made from gabion cages filled with either stones or a sand-schredded-tyre mixture. For the first time, sensors were placed in different locations within the structure to measure real-time accelerations and displacements. The test conditions, measurement methods and results are presented in detail. The structure's response is discussed in a descriptive and phenomenological approach and compared with previous real-scale experiments on other types of embankments.

  19. 38. A photograph taken from the U.S. 24 embankment looking ...

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

    38. A photograph taken from the U.S. 24 embankment looking south, showing a unit dug to prove the length of the southwestern breast wall (in the right middle ground, beyond the cribs) and the irregular configuration of some of the ties within the cribs. - Wabash & Erie Canal, Lock No. 2, 8 miles east of Fort Wayne, adjacent to U.S. Route 24, New Haven, Allen County, IN

  20. Dynamic earth pressure on rigid retaining walls induced by a neighboring machine foundation, by the meshless local Petrov-Galerkin method

    NASA Astrophysics Data System (ADS)

    Veiskarami, Mehdi; Bahar, Arash; Zandi Lak, Erfan

    2015-12-01

    Dynamic earth pressure induced by machine foundations on a neighboring retaining wall is analyzed with emphasis on factors which control the intensity and location of the design forces. The meshless local Petrov-Galerkin (MLPG) method is used to analyze the problem for a variety of retaining wall and machine foundation geometries. The soil medium is assumed to be homogeneous and visco-elastic. The machine foundation is idealized as a harmonic sinusoidal dynamic force often encountered in practice. A number of analyses have been made to reveal the effect of the loading frequency, the location and size of the foundation and the soil shear wave velocity on the distribution and magnitude of the dynamic earth pressure. Results indicate that there is a critical frequency and a critical location for which the passive pressure takes the maxima in the entire duration of the dynamic load.

  1. Recruiting and retaining indigenous farmworker participants.

    PubMed

    Farquhar, Stephanie; de Jesus Gonzalez, Carmen; Hall, Jennifer; Samples, Julie; Ventura, Santiago; Sanchez, Valentin; Shadbeh, Nargess

    2014-10-01

    There is limited information on the specific practices used to successfully recruit and retain indigenous and Latino farmworkers in research studies. This article describes the strategies used in a community-based participatory research project with indigenous agricultural workers. Participants were recruited through consulting with indigenous relatives and friends, identifying and meeting with indigenous leaders from hometown associations in countries of origin, and asking current participants to recruit fellow farmworkers. Adjustments were initiated to the second year protocol to enhance recruitment and retention. The difference in attrition rates between years one and two was statistically significant, a difference partially attributed to modifications to recruitment and retention protocol. Findings confirmed that active recruitment techniques and word-of-mouth recruitment were more effective than passive methods. Trust among academic, organization, and community partners, and shared language and culture between those doing the recruitment and the participants, contributed to sustained farmworker participation. PMID:23733354

  2. Recruiting and retaining indigenous farmworker participants

    PubMed Central

    Farquhar, Stephanie; de Jesus Gonzalez, Carmen; Hall, Jennifer; Samples, Julie; Ventura, Santiago; Sanchez, Valentin; Shadbeh, Nargess

    2013-01-01

    There is limited information on the specific practices used to successfully recruit and retain indigenous and Latino farmworkers in research studies. This article describes the strategies used in a community-based participatory research project with indigenous agricultural workers. Participants were recruited through consulting with indigenous relatives and friends, identifying and meeting with indigenous leaders from hometown associations in countries of origin, and asking current participants to recruit fellow farmworkers. Adjustments were initiated to the second year protocol to enhance recruitment and retention. The difference in attrition rates between years one and two was statistically significant, a difference partially attributed to modifications to recruitment and retention protocol. Findings confirmed that active recruitment techniques and word-of-mouth recruitment were more effective than passive methods. Trust among academic, organization, and community partners, and shared language and culture between those doing the recruitment and the participants, contributed to sustained farmworker participation. PMID:23733354

  3. Strength of field compacted clayey embankments

    NASA Astrophysics Data System (ADS)

    Liang, Y.; Lovell, C. W.

    1982-02-01

    The shearing behavior of a plastic Indiana clay (St. Croix) was studied for both laboratory and field compaction. This interim report deals with the field compacted phase. The strength tests were performed by unconsolidated undrained (UU) and saturated consolidated undrained (CIU) triaxials. These were run at various confining pressures to approximate the end of construction and long term conditions at several embankment depths.

  4. Retained Placenta Accreta Mimicking Choriocarcinoma

    PubMed Central

    Kohi, Maureen P.; Rizzuto, Gabrielle A.; Fidelman, Nicholas; Lucero, Jennifer; Thiet, Mari-Paule

    2015-01-01

    This case demonstrates a rare event of retained invasive placenta masquerading as choriocarcinoma. The patient presented with heavy vaginal bleeding following vaginal delivery complicated by retained products of conception. Ultrasound and computed tomography demonstrated a vascular endometrial mass, invading the uterine wall and raising suspicion for choriocarcinoma. Hysterectomy revealed retained invasive placenta. PMID:26495146

  5. Inundation risk for embanked rivers

    NASA Astrophysics Data System (ADS)

    Strupczewski, W. G.; Kochanek, K.; Bogdanowicz, E.; Markiewicz, I.

    2013-08-01

    The Flood Frequency Analysis (FFA) concentrates on probability distribution of peak flows of flood hydrographs. However, examination of floods that haunted and devastated the large parts of Poland lead us to revision of the views on the assessment of flood risk of Polish rivers. It turned out that flooding is caused not only by the overflow of the levee crest but also due to the prolonged exposure to high water on levees structure causing dangerous leaks and breaches that threaten their total destruction. This is because the levees are weakened by long-lasting water pressure and as a matter of fact their damage usually occurs after the culmination has passed the affected location. The probability of inundation is the total of probabilities of exceeding embankment crest by flood peak and the probability of washout of levees. Therefore, in addition to the maximum flow one should also consider the duration of high waters in a river channel. In the paper the new two-component model of flood dynamics: "Duration of high waters-Discharge Threshold-Probability of non-exceedance" (DqF), with the methodology of its parameter estimation was proposed as a completion to the classical FFA methods. Such a model can estimate the duration of stages (flows) of an assumed magnitude with a given probability of exceedance. The model combined with the technical evaluation of the probability of levee breaches due to the duration (d) of flow above alarm stage gives the annual probability of inundation caused by the embankment breaking. The results of theoretical investigation were illustrated by a practical example of the model implementation to the series of daily flow of the Vistula River at Szczucin. Regardless of promising results, the method of risk assessment due to prolonged exposure of levees to high water is still in its infancy despite its great cognitive potential and practical importance. Therefore, we would like to point out the need for and usefulness of the DqF model as

  6. Inundation risk for embanked rivers

    NASA Astrophysics Data System (ADS)

    Strupczewski, W. G.; Kochanek, K.; Bogdanowicz, E.; Markiewicz, I.

    2013-03-01

    The Flood Frequency Analysis (FFA) concentrates on probability distribution of peak flows of flood hydrographs. However, examination of floods that haunted and devastated the large parts of Poland lead us to revision of the views on the assessment of flood risk of Polish rivers. It turned out that flooding is caused not only by overflow of the levees' crest but mostly due to the prolonged exposure to high water on levees structure causing dangerous leaks and breaches that threaten their total destruction. This is because, the levees are weakened by long-lasting water pressure and as a matter of fact their damage usually occurs after the culmination has passed the affected location. The probability of inundation is the total of probabilities of exceeding embankment crest by flood peak and the probability of washout of levees. Therefore, in addition to the maximum flow one should consider also the duration of high waters in a river channel. In the paper the new two-component model of flood dynamics: "Duration of high waters-Discharge Threshold-Probability of non-exceedance" (DqF), with the methodology of its parameters estimation was proposed as a completion to the classical FFA methods. Such model can estimate the duration of stages (flows) of an assumed magnitude with a given probability of exceedance. The model combined with the technical evaluation of probability of levees breach due to the d-days duration of flow above alarm stage gives the annual probability of inundation caused by the embankment breaking. The results of theoretical investigation were illustrated by a practical example of the model implementation to the series of daily flow of the Vistula River at Szczucin. Regardless promising results, the method of risk assessment due to prolonged exposure of levees to high water is still in its infancy despite its great cognitive potential and practical importance. Therefore, we would like to point out the need for and usefulness of the DqF model as

  7. 5 CFR 531.241 - Retaining and losing GM status.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... retained rate under 5 CFR part 536. (A retained grade is not considered in determining whether a GM employee has been reduced in grade. See 5 CFR 536.205.) ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Retaining and losing GM status....

  8. Rock walls and stairs leading to amphitheater from North Oakwood ...

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

    Rock walls and stairs leading to amphitheater from North Oakwood Drive, near hospital (facility no. 515). - Hamilton Field, Rock Retaining Walls, Various locations in housing & hospital areas, Novato, Marin County, CA

  9. Acquisition and Retaining Granular Samples via a Rotating Coring Bit

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Badescu, Mircea; Sherrit, Stewart

    2013-01-01

    This device takes advantage of the centrifugal forces that are generated when a coring bit is rotated, and a granular sample is entered into the bit while it is spinning, making it adhere to the internal wall of the bit, where it compacts itself into the wall of the bit. The bit can be specially designed to increase the effectiveness of regolith capturing while turning and penetrating the subsurface. The bit teeth can be oriented such that they direct the regolith toward the bit axis during the rotation of the bit. The bit can be designed with an internal flute that directs the regolith upward inside the bit. The use of both the teeth and flute can be implemented in the same bit. The bit can also be designed with an internal spiral into which the various particles wedge. In another implementation, the bit can be designed to collect regolith primarily from a specific depth. For that implementation, the bit can be designed such that when turning one way, the teeth guide the regolith outward of the bit and when turning in the opposite direction, the teeth will guide the regolith inward into the bit internal section. This mechanism can be implemented with or without an internal flute. The device is based on the use of a spinning coring bit (hollow interior) as a means of retaining granular sample, and the acquisition is done by inserting the bit into the subsurface of a regolith, soil, or powder. To demonstrate the concept, a commercial drill and a coring bit were used. The bit was turned and inserted into the soil that was contained in a bucket. While spinning the bit (at speeds of 600 to 700 RPM), the drill was lifted and the soil was retained inside the bit. To prove this point, the drill was turned horizontally, and the acquired soil was still inside the bit. The basic theory behind the process of retaining unconsolidated mass that can be acquired by the centrifugal forces of the bit is determined by noting that in order to stay inside the interior of the bit, the

  10. The VLF-EM imaging of potential collapse on the LUSI embankment

    NASA Astrophysics Data System (ADS)

    Sungkono; Husein, Alwi; Prasetyo, Hardi; Bahri, Ayi S.; Monteiro Santos, Fernando A.; Santosa, Bagus J.

    2014-10-01

    Collapse and overtopping repeatedly occur in LUSI Embankment. Discontinuities (crack or fracture) in the embankment are major reasons for embankment failures or collapses. Very-low frequency electromagnetic (VLF-EM) measurement is essentially a non-destructive technique which displays subsurface 2-D cross section of resistivity. The cross section result has the possibility of detecting discontinuities and liquid saturation in embankment before it collapsed by observing which part of it in the cross section has low resistivity. This paper presents results of a survey conducted at the LUSI embankment in Eastern Java, Indonesia in a part of potential collapse. VLF-EM profiles measured along the embankment crest provided an overview of the whole embankment and served to detect anomalous zones. The noise assisted multivariate empirical mode decomposition (NA-MEMD) is applied to reject unwanted VLF-EM noise and Inv2DVLF software is applied to obtain result of 2-D resistivity models. In the selected area, the drill log and the standard penetration test (SPT) value gave detailed information about subsurface layer below embankment. This information is valuable for supporting 2-D resistivity image obtained from VLF-EM data inversion. Furthermore, the low resistivity in embankment layer is associated to discontinuities (fracture, crack or fault) along the embankment which caused its collapse.

  11. An expression for the water-sediment moving layer in unsteady flows valid for open channels and embankments

    NASA Astrophysics Data System (ADS)

    Berta, A. M.; Bianco, G.

    2010-05-01

    During the floods, the effects of sediment transport in river beds are particulary significant and can be studied through the evolution of the water-sediment layer which moves in the lower part of a flow, named "moving layer". Moving layer variations along rivers lead to depositions and erosions and are typically unsteady, but are often tackled with expressions developed for steady (equilibrium) conditions. In this paper, we develop an expression for the moving layer in unsteady conditions and calibrate it with experimental data. During laboratory tests, we have in fact reproduced a rapidly changing unsteady flow by the erosion of a granular steep slope. Results have shown a clear tendency of the moving layer, for fixed discharges, toward equilibrium conditions. Knowing the equilibrium achievement has presented many difficulties, being influenced by the choice of the equilibrium expression and moreover by the estimation of the parameters involved (for example friction angle). Since we used only data relevant to hyper-concentrated mono-dimensional flows for the calibration - occurring for slope gradients in the range 0.03-0.20 - our model can be applied both on open channels and on embankments/dams, providing that the flows can be modelled as mono-dimensional, and that slopes and applied shear stress levels fall within the considered ranges.

  12. Modeling of hydrologic conditions and solute movement in processed oil shale waste embankments under simulated climatic conditions

    SciTech Connect

    Turner, J.P.; Hasfurther, V.

    1992-05-04

    The scope of the research program and the continuation is to study interacting hydrologic, geotechnical, and chemical factors affecting the behavior and disposal of combusted processed oil shale. The research combines bench-scale testing with large scale research sufficient to describe commercial scale embankment behavior. The large scale approach was accomplished by establishing five lysimeters, each 7.3 [times] 3.0 [times] 3.0 m deep, filled with processed oil shale that has been retorted and combusted by the Lurgi-Ruhrgas (Lurgi) process. Approximately 400 tons of Lurgi processed oil shale waste was provided by Rio Blanco Oil Shale Co., Inc. (RBOSC) through a separate cooperative agreement with the University of Wyoming (UW) to carry out this study. Three of the lysimeters were established at the RBOSC Tract C-a in the Piceance Basin of Colorado. Two lysimeters were established in the Environmental Simulation Laboratory (ESL) at UW. The ESL was specifically designed and constructed so that a large range of climatic conditions could be physically applied to the processed oil shale which was filled in the lysimeter cells.

  13. Discussion of "Simple design criterion for residual energy on embankment dam stepped spillways" by Stefan Felder and Hubert Chanson

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Researchers from the University of Queensland of New South Wales provided guidance to designers regarding the hydraulic performance of embankment dam stepped spillways. Their research compares a number of high-quality physical model data sets from multiple laboratories, emphasizing the variability ...

  14. 75. SECONDARY MILL AND CLASSIFIER FROM NORTHEAST. NOTE STONE/CONCRETE RETAINING ...

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

    75. SECONDARY MILL AND CLASSIFIER FROM NORTHEAST. NOTE STONE/CONCRETE RETAINING WALL TRANSITION AT RIGHT, BARREN SOLUTION PIPE FROM BARREN SOLUTION TANK, TOP CENTER, AND JOISTS FOR PRIMARY THICKENER No. 1, UPPER RIGHT. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  15. Design of highway embankments using tire chips

    SciTech Connect

    Bosscher, P.J.; Edil, T.B.; Kuraoka, S.

    1997-04-01

    This paper describes research undertaken to develop design procedures for using shredded scrap tires as a lightweight fill material in highway construction. The benefits of using scrap tires are particularly enhanced if they can be used to replace virgin construction materials made from nonrenewable resources. This paper addresses the use of tire chips as a highway embankment material. Design parameters for embankments constructed using discarded shredded tires are presented based on laboratory model studies, numerical analyses, and field performance of test fills. The conclusions of this report support the use of tire chips as an environmentally acceptable lightweight fill in highway applications if properly confined. Recommendations for design procedures and construction specifications for the use of tire chips in highway fills are provided.

  16. Tools for Success in Recruiting and Retaining Hispanic Students

    ERIC Educational Resources Information Center

    Gilroy, Marilyn

    2010-01-01

    In this article, the author talks about strategies for success in recruiting and retaining Hispanic students. One strategy suggested by Raul Lorenzo, account director for Bauza & Associates, a Hispanic marketing agency that helps colleges and universities recruit and retain Hispanic students, is that institutions need to speak to the heart as well…

  17. Cruciate retaining and cruciate substituting ultra-congruent insert

    PubMed Central

    Deledda, Davide; Rosso, Federica; Ratto, Nicola; Bruzzone, Matteo; Bonasia, Davide Edoardo; Rossi, Roberto

    2016-01-01

    The posterior cruciate ligament (PCL) conservation and the polyethylene insert constraint in total knee arthroplasty (TKA) are still debated. The PCL is one of the primary stabilizers of the joint, but cruciate retaining (CR) implants have the disadvantage of a difficult balancing of the PCL. Postero-stabilized (PS) implants were introduced to reduce this problem. However, also the PS implants have some disadvantages, due to the cam-mechanism, such as high risk of cam-mechanism polyethylene wear. To minimize the polyethylene wear of the cam-mechanism and the bone sacrifice due to the intercondylar box, different types of inserts were developed, trying to increase the implant conformity and to reduce stresses on the bone-implant interface. In this scenario ultra-congruent (UC) inserts were developed. Those inserts are characterized by a high anterior wall and a deep-dished plate. This conformation should guarantee a good stability without the posterior cam. Few studies on both kinematic and clinical outcomes of UC inserts are available. Clinical and radiological outcomes, as well as kinematic data are similar between UC mobile bearing (MB) and standard PS MB inserts at short to mid-term follow-up. In this manuscript biomechanics and clinical outcomes of UC inserts will be described, and they will be compared to standard PS or CR inserts. PMID:26855938

  18. Virtual techniques for designing and fabricating a retainer.

    PubMed

    Nasef, Ahmed A; El-Beialy, Amr R; Mostafa, Yehya A

    2014-09-01

    The purpose of this article was to report a procedure for using 3-dimensional cone-beam computed tomography imaging, computer-aided design, computer-aided manufacturing, and rapid prototyping to design and produce a retainer. PMID:25172262

  19. [Removal of nitrogen in simulated rivers embanked by ecological concrete].

    PubMed

    Chen, Yang-hui; Lü, Xi-wu; Wu, Yi-feng

    2008-08-01

    The removal of nitrogen was studied in four types of pilot-scale rivers. The embankment for rivers No. 1, 2 and 3 consisted of respectively spheriform ecological-concrete prefab-bricks, rectangular ecological-concrete prefab-bricks and square ecological-concrete prefab-bricks with 4 hemispheroids. The embankment for river No. 4 was made of concrete C25. The results show that the removal rates of NH4+ -N, NO2- -N, NO3- -N and TN of river 1 are 83.6%, 75.2%, 37.1% and 47.5% under hydraulic retention time of 2 days, 83.4%, 53.0%, 30.6% and 40.4% for river 2, 88.1%, 72.4%, 33.0% and 40.9% for river 3. Under the same condition, NH4+ -N, TN of river 4 decreasesby 61.1%, 9.1%, while NO2- -N, NO3- -N increase by 7.4%, 3.4% due to the transformation of NH4+ -N. It indicates that ecological embankment rivers can effectively remove nitrogen. Besides, the addition of pore rate in embankment structure and more rate of plant coverage are good for the removal of nitrogen in ecological embankment rivers. PMID:18839568

  20. Strategies for Recruiting and Retaining Hispanic Students

    ERIC Educational Resources Information Center

    Devall, Esther L.; Vail, Ann; Resendez, Jeanne

    2005-01-01

    Hispanic Americans are the largest- and fastest growing minority group in the U.S., yet their higher education enrollment and graduation rates lag behind those of other ethnic groups. In the Department of Family and Consumer Sciences at New Mexico State University, 42% of students are Hispanic. Of the students who graduate each year, 40% are…

  1. Attracting, Retaining, and Engaging Early Career Scientists

    NASA Astrophysics Data System (ADS)

    Jones, Alan; Heal, Kate; Pringle, Daniel

    2007-12-01

    Young Scientists Event, IUGG XXIV General Assembly; Perugia, Italy, 10 July 2007 This young scientists event was organized to engage younger scientists with the International Union of Geodesy and Geophysics (IUGG) and to provide a specific forum to express their views at the General Assembly. It comprised a panel discussion chaired by Kate Heal and with three young geosciences panelists (Masaki Hayashi, University of Calgary, Canada; Kalachand Sain, National Geophysical Research Institute, Hyderabad, India; and Simona Stefanescu, National Meteorological Administration, Bucharest). The group, which had identified several topics relevant to young geoscientists, presented their views in open discussion session. Thirty IUGG conference attendees were present.

  2. Attracting and Retaining Teachers in Rural Areas.

    ERIC Educational Resources Information Center

    Harmon, Hobart L.

    Although the problem varies across the United States, overall there is a shortage of rural teachers, especially in the subject areas of math, science, and special education. Recruiting teachers for rural settings requires targeting persons with rural backgrounds, attacking the negative stereotypes surrounding rural schools, and stressing the…

  3. Employee Engagement: Motivating and Retaining Tomorrow's Workforce

    ERIC Educational Resources Information Center

    Shuck, Michael Bradley; Wollard, Karen Kelly

    2008-01-01

    Tomorrow's workforce is seeking more than a paycheck; they want their work to meet their needs for affiliation, meaning, and self-development. Companies willing to meet these demands will capture the enormous profit potential of a workforce of fully engaged workers. This piece explores what engagement is, why it matters, and how human resource…

  4. Recruiting and Retaining Male Special Education Teachers

    ERIC Educational Resources Information Center

    Rice, Craig J.; Goessling, Deborah Peters

    2005-01-01

    The percentage of male students who complete an undergraduate degree in the field of special education continues to be much lower than that of female graduates. Low status, low salaries, the perception of teaching as women's work, potential complaints of child abuse and sexual harassment, and a lack of male peer groups factor into this low…

  5. Mentoring To Develop and Retain New Teachers.

    ERIC Educational Resources Information Center

    Monsour, Florence

    2003-01-01

    Suggests that mentoring shows great promise and proven results in supporting new teachers, describing the successful Beginning Teacher Assistance Program at the University of Wisconsin River Falls and examining: what makes mentoring work, the importance of commitment to the theory of mentoring, benefits for mentees, overcoming obstacles to…

  6. Attracting and Retaining Learning Disability Student Nurses

    ERIC Educational Resources Information Center

    Owen, Sara; Standen, Penny

    2007-01-01

    Recruitment onto pre-registration learning disability nursing courses has decreased considerably over the last decade. This paper reports the findings of the first stage of a longitudinal study that investigated the factors that influence students to train as learning disability nurses, and those that influence their decision to continue or leave…

  7. Hiring and Retaining Great Independent School Teachers

    ERIC Educational Resources Information Center

    Balossi, Matt; Hernández, Natalie R.

    2016-01-01

    While numerous studies measure teacher effectiveness in public schools, there is little research on teacher quality among independent schools. In fact, the topic of teacher quality in public schools receives widespread media coverage, funding, and special interest. In order to better understand how independent schools describe high-quality…

  8. Teachers Wanted: Attracting and Retaining Good Teachers

    ERIC Educational Resources Information Center

    Heller, Daniel A.

    2004-01-01

    Just as the pool of qualified teacher applicants is shrinking and attrition rates are soaring, new standards are making entry into the teaching profession more difficult. Teachers can make sure their school system doesn't get caught in the crunch by implementing the approach from this visionary guide. Daniel A. Heller describes a top-to-bottom…

  9. Reengineering marketing to retain and win customers

    SciTech Connect

    Hobson, J.

    1995-12-31

    According to the Oxford Dictionary, to engineer is to plan or accomplish something artfully by applying skill or contrivance. Reengineering implies starting again. Thus, it is no great surprise that business reengineering is the process of going back to the beginning and devising a better way of accomplishing the desired result. Michael Hammer, the originator of the concept of business reengineering, gives this definition: {open_quotes}Reengineering is the fundamental rethinking and radical redesign of business processes to achieve dramatic improvements in critical, contemporary measures of performance, such as cost, quality, service, and speed{close_quotes}. Not every process requires reengineering. If the process is narrow and has little impact on overall corporate performance, it is not a candidate for reengineering. More importantly the appropriate measure of reengineering success is found on the bottom line-not in improvements in individual processes. Thus, since the goal is to produce extensive, enduring profit improvement, the reengineering project must be broad and it must penetrate deep to the companys core. Identifying the activities that are critical for value creation in the whole business unit is not easy. For example, while it may be of interest to redesign the accounts-payable process, the result will probably be about a 1-2% cost reduction as a percent of the business unit. Likewise, redesign of a cross-functional process such as new product development, will result in a meager 3-5% cost reduction. Compare this to projects that reengineered processes that involve the critical activities of the business unit - those processes that propel competitive advantage - these projects result in a 15-20% reduction in business-unit costs.

  10. Apparatus for retaining and releasing a payload

    NASA Technical Reports Server (NTRS)

    Carrier, Alain (Inventor); Cobb, Bruce (Inventor)

    2000-01-01

    An apparatus for latching an object, such as a payload for a space vehicle, includes an expandible latch which is shifted between a relaxed open condition and a flexed closed condition by actuation of a pair of temperature-responsive members, such as shaped memory alloy (SMA) coil springs. One of the two temperature-responsive members biases an actuator into a first position that allows the expandible latch to open. The other SMA member biases the actuator in the opposite position to close the expandible latch. Heating the appropriate SMA member causes the actuator to move from one position to the other position. In the preferred embodiment, no power is required to maintain the actuator in either position once the position has been established. For example, the actuator may have a rest position that allows the expandible latch to remain open when the two SMA members are cooled and allowed to reach an equilibrium condition with respect to applied force to the actuator. A detent-and-ball arrangement may be used to maintain the position of the actuator after the expandible latch has been closed.

  11. Influences of sand accumulation on crushed-rock embankment along the Qinghai-Tibet Railway, China

    NASA Astrophysics Data System (ADS)

    Zu, Ruiping; He, Zhilin; Zong, Yumei; Zhang, Kecun; Qu, Jianjun

    2016-04-01

    The crushed-rock embankment, which is widely used in the Qinghai-Tibet Railway (QTR), has been proven to have active cooling effects and can effectively protect the stability of embankment in permafrost regions. However, with the increasing of desertification in Tibetan Plateau, the crushed-rock embankments along the QTR have suffered from sand filling or burial seriously, and the influences of sand accumulation on the crushed-rock embankment have not been effectively resolved so far. Therefore, this paper simulated the ground temperature variation in the case of the crushed-rock embankment filled and buried by sand through the indoor experiment. The results show that the bare crushed-rock has good cooling effect on its underlying embankment, but after filled or buried by sand, its cooling effect will significantly reduce or even disappear, and the thicker the sand layer, the higher the ground temperature of frozen soil. In the long term, the sand accumulation could be a serious and potential threat to embankment of the QTR. In order to ensure the stability of the crushed-rock embankment and safe operation of the QTR, it is necessary to set up comprehensive sand-protecting system along the railway as soon as possible.

  12. NORTH EMBANKMENT IN FOREGROUND, WITH (LR) SUBSTATION (MI98D), POWERHOUSE (MI98C), ...

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

    NORTH EMBANKMENT IN FOREGROUND, WITH (L-R) SUBSTATION (MI-98-D), POWERHOUSE (MI-98-C), AND COOKE DAM POND IN BACKGROUND. VIEW TO SOUTH - Cooke Hydroelectric Plant, North Embankment, Cook Dam Road at Au Sable River, Oscoda, Iosco County, MI

  13. Attracting and Retaining Women in Science and Engineering

    ERIC Educational Resources Information Center

    Rosser, Sue V.

    2003-01-01

    Fiscal year 2001 marked an important milestone in policies to attract and retain women in science and engineering. That year, the National Science Foundation (NSF) initiated an awards program called ADVANCE at a funding level of $19 million. The program supports efforts by institutions and individuals to empower women to participate fully in…

  14. Final report of coordination and cooperation with the European Union on embankment failure analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There has been an emphasis in the European Union (EU) community on the investigation of extreme flood processes and the uncertainties related to these processes. Over a 3-year period, the EU and the U.S. dam safety community (1) coordinated their efforts and collected information needed to integrate...

  15. From Freshman to Graduate: Recruiting and Retaining Minority Students

    ERIC Educational Resources Information Center

    Hobson-Horton, Lisa D.; Owens, Lula

    2004-01-01

    The purpose of this research project was to identify methods to retain minority teacher education candidates and identify curricular and environmental factors that affect recruitment and retention of minority teacher education candidates and student teachers. Because of the low enrollment of minority students in the department in comparison to the…

  16. Recruiting and Retaining Rural School Administrators. ERIC Digest.

    ERIC Educational Resources Information Center

    Howley, Aimee; Pendarvis, Edwina

    School districts nationwide, but especially rural districts, are finding it hard to recruit and retain administrators. In the past 25 years, administrators have had to address increasing demands for special programs, collaborative decision making, and accountability. In addition, potential for conflict with school boards and various constituencies…

  17. Rural Education: Attracting and Retaining Teachers in Small Schools

    ERIC Educational Resources Information Center

    Lowe, Jerry M.

    2006-01-01

    For many small rural school districts across America, the effort to attract and retain quality teachers continues to be a major concern. Schools located in what are considered to be "hard to staff" areas experience the most difficult. While not all communities face the problems of inadequate teacher supply, many small and rural school districts…

  18. An Integrated Approach to Recruiting and Retaining Appalachian Engineering Students

    ERIC Educational Resources Information Center

    Winn, Gary; Hensel, Robin; Curtis, Reagan; Taylor, Lydotta M.; Cilento, Gene

    2012-01-01

    Recruiting and retaining Appalachian engineering students is difficult for a variety of ecological and cultural reasons. At West Virginia University an NSF STEP grant has allowed the development of specific interventions to evolve from an ecological model we describe here. The interventions include web-based, realistic engineering design exercises…

  19. Attracting and Retaining Teachers: A Question of Motivation

    ERIC Educational Resources Information Center

    Muller, Karin; Alliata, Roberta; Benninghoff, Fabienne

    2009-01-01

    Attracting and retaining competent teachers is a key concern when it comes to managing the supply and demand for teachers. This article examines the motivation that prompts people to enter or leave the teaching profession with the aim of identifying a decision framework for defining teacher policies. The results are based on the teacher workforce…

  20. Attracting and Retaining High-Quality Professionals in Science Education.

    ERIC Educational Resources Information Center

    Weld, Jeffrey

    1998-01-01

    To attract and retain high-quality teachers, the education system must address science teachers' sense of professional isolation, administrators' lack of receptivity to thoughtful teachers' ideas, egalitarian salary compensation schemes, and lack of professional recognition. An outstanding chemistry teacher-turned-pharmaceutical saleswoman is…

  1. Recruiting and Retaining Physicians in Very Rural Areas

    ERIC Educational Resources Information Center

    Pepper, Carolyn M.; Sandefer, Ryan H.; Gray, Matt J.

    2010-01-01

    Context: Recruiting and retaining physicians is a challenge in rural areas. Growing up in a rural area and completing medical training in a rural area have been shown to predict decisions to practice in rural areas. Little is known, though, about factors that contribute to physicians' decisions to locate in very sparsely populated areas. Purpose:…

  2. Rheology and retained gas measurements in Hanford tank 101-SY

    SciTech Connect

    Shepard, C.L.; Alzheimer, J.M.; Terrones, G.

    1995-12-31

    Several high-level radioactive waste tanks at the Hanford site are known to produce flammable gases. The best known of these tanks is tank 241-SY-101, and to mitigate the safety concerns associated with flammable gas release from this tank, a mixer pump was installed in mid-1993 to mix the waste contents and thereby eliminate or reduce the capability of the waste to retain gas. The mixer pump has proven very effective and only needs to be operated for 30 min about every other day. Large periodic gas release events no longer occur in this tank. However, specific information about the Theological character of the mixed waste and the amount of retained gas has been lacking. In order to determine the amount of gas still retained in the waste and the rheology of the mixed fluid, which is important in establishing the capability of the waste for retaining gas, two instruments were developed to probe the waste in situ. These instruments were the ball rheometer and the void fraction instrument (VFI).

  3. Identification of a Lipoteichoic Acid Glycosyltransferase Enzyme Reveals that GW-Domain-Containing Proteins Can Be Retained in the Cell Wall of Listeria monocytogenes in the Absence of Lipoteichoic Acid or Its Modifications

    PubMed Central

    Percy, Matthew G.; Karinou, Eleni; Webb, Alexander J.

    2016-01-01

    ABSTRACT Listeria monocytogenes is a foodborne Gram-positive bacterial pathogen, and many of its virulence factors are either secreted proteins or proteins covalently or noncovalently attached to the cell wall. Previous work has indicated that noncovalently attached proteins with GW (glycine-tryptophan) domains are retained in the cell wall by binding to the cell wall polymer lipoteichoic acid (LTA). LTA is a glycerol phosphate polymer, which is modified in L. monocytogenes with galactose and d-alanine residues. We identified Lmo0933 as the cytoplasmic glycosyltransferase required for the LTA glycosylation process and renamed the protein GtlA, for glycosyltransferase LTA A. Using L. monocytogenes mutants lacking galactose or d-alanine modifications or the complete LTA polymer, we show that GW domain proteins are retained within the cell wall, indicating that other cell wall polymers are involved in the retention of GW domain proteins. Further experiments revealed peptidoglycan as the binding receptor as a purified GW domain fusion protein can bind to L. monocytogenes cells lacking wall teichoic acid (WTA) as well as purified peptidoglycan derived from a wild-type or WTA-negative strain. With this, we not only identify the first enzyme involved in the LTA glycosylation process, but we also provide new insight into the binding mechanism of noncovalently attached cell wall proteins. IMPORTANCE Over the past 20 years, a large number of bacterial genome sequences have become available. Computational approaches are used for the genome annotation and identification of genes and encoded proteins. However, the function of many proteins is still unknown and often cannot be predicted bioinformatically. Here, we show that the previously uncharacterized Listeria monocytogenes gene lmo0933 likely codes for a glycosyltransferase required for the decoration of the cell wall polymer lipoteichoic acid (LTA) with galactose residues. Using L. monocytogenes mutants lacking LTA

  4. Good Laboratory Practice. Part 2. Recording and Retaining Raw Data

    ERIC Educational Resources Information Center

    Wedlich, Richard C.; Libera, Agata E.; Pires, Amanda; Tellarini, Cassandra

    2013-01-01

    A clear understanding of how "raw data" is defined, recorded, and retained in the laboratory record is essential to the chemist employed in the laboratory compliant with the Good Laboratory Practices regulations. This article is intended to provide an understanding by drawing upon examples taken from the modern pharmaceutical analysis…

  5. 31 CFR 203.16 - Retainer and investor depositaries.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... account balance. On the business day that the TSC receives an AOC from a retainer or investor depositary, the TSC will credit the depositary's TIP main account balance for the amount reported on the AOC... debited to the reserve account and credited to the TGA. (b) Late delivery of AOC. If an AOC does...

  6. Clean-coal technology by-products used in a highway embankment stabilization demonstration project. Master's thesis

    SciTech Connect

    Nodjomian, S.M.

    1994-01-01

    Clean-coal technology by-products are used in a highway embankment demonstration project. This research chronicles the procedures used in the process and analyzes the stability of a repaired highway embankment. The reconstructed slope is analyzed using an Intelligent Discussion Support System that was developed from a slope stability program. Water quality studies are performed and an instrumentation plan is suggested. The calculated factors of safety and the observed embankment performance give indications that the field demonstration project was a success. Long-term monitoring will be the best barometer for determining embankment gross movement and the future of FGD by-products as a stabilizing material.

  7. Simulating effects of highway embankments on estuarine circulation

    USGS Publications Warehouse

    Lee, Jonathan K.; Schaffranek, Raymond W.; Baltzer, Robert A.

    1994-01-01

    A two-dimensional depth-averaged, finite-difference, numerical model was used to simulate tidal circulation and mass transport in the Port Royal Sound. South Carolina, estuarine system. The purpose of the study was to demonstrate the utility of the Surface-Water. Integrated. Flow and Transport model (SWIFT2D) for evaluating changes in circulation patterns and mass transport caused by highway-crossing embankments. A model of subregion of Port Royal Sound including the highway crossings and having a grid size of 61 m (200ft) was derived from a 183-m (600-ft) model of the entire Port Royal Sound estuarine system. The 183-m model was used to compute boundary-value data for the 61-m submodel, which was then used to simulate flow conditions with and without the highway embankments in place. The numerical simulations show that, with the highway embankment in place, mass transport between the Broad River and Battery Creek is reduced and mass transport between the Beaufort River and Battery Creek is increased. The net result is that mass transport into and out of upper Battery Creek is reduced. The presence of the embankments also alters circulation patterns within Battery Creek.

  8. Evolution of an Interfacial Crack on the Concrete Embankment Boundary

    NASA Astrophysics Data System (ADS)

    Smith, J.; Ezzedine, S. M.; Lomov, I.; Kanarska, Y.; Antoun, T.; Glascoe, L. G.; Hall, R. L.; Woodson, S. C.

    2013-12-01

    Failure of a dam can have subtle beginnings: a small crack or dislocation at the interface of the concrete dam and the surrounding embankment soil initiated by a seismic event, for example, can: a) result in creating gaps between the concrete dam and the lateral embankments; b) initiate internal erosion of embankment; and c) lead to a catastrophic failure of the dam. The dam may ';self-rehabilitate' if a properly designed granular filter is engineered around the embankment. Currently, the design criteria for such filters have only been based on experimental studies. We demonstrate the numerical prediction of filter effectiveness at the soil grain scale and relate it to the larger dam scale. Validated computer predictions highlight that a resilient (or durable) filter is consistent with the current design specifications for dam filters. These predictive simulations, unlike the design specifications, can be used to assess filter success or failure under different soil or loading conditions and can lead to meaningful estimates of the timing and nature of full-scale dam failure. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and was sponsored by the Department of Homeland Security (DHS), Science and Technology Directorate, Homeland Security Advanced Research Projects Agency (HSARPA).

  9. Simplified physically based model of earthen embankment breaching

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A simplified physically based model has been developed to simulate the breaching processes of homogenous and composite earthen embankments owing to overtopping and piping. The breach caused by overtopping flow is approximated as a flat broad-crested weir with a trapezoidal cross section, downstream ...

  10. WinDAM B earthern embankment overtopping analysis software

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Windows Dam Analysis Modules (WinDAM) is a modular software application being developed for the analysis of overtopped earth embankments and internal erosion. The development is being carried out in stages. The initial computational model development addressed routing of the flood through the rese...

  11. BREACH WIDENING OBSERVATIONS RELATED TO CLAY CORE EARTHEN EMBANKMENT TESTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many earthen embankment dams are reaching the end of their planned design and economic life. Over their service life, shifting hydrologic conditions, hazard classification changes, sedimentation causing reduction in storage volumes, or a combination of these items has raised the concern for dam ove...

  12. Construction of a test embankment using a sand-tire shred mixture as fill material.

    PubMed

    Yoon, Sungmin; Prezzi, Monica; Siddiki, Nayyar Zia; Kim, Bumjoo

    2006-01-01

    Use of tire shreds in construction projects, such as highway embankments, is becoming an accepted way of beneficially recycling scrap tires. However, in the last decade there was a decline in the use of pure tire shreds as fill materials in embankment construction, as they are susceptible to fire hazards due to the development of exothermic reactions. Tire shred-sand mixtures, on the other hand, were found to be effective in inhibiting exothermic reactions. When compared with pure tire shreds, tire shred-sand mixtures are less compressible and have higher shear strength. However, the literature contains limited information on the use of tire shred-soil mixtures as a fill material. The objectives of this paper are to discuss and evaluate the feasibility of using tire shred-sand mixtures as a fill material in embankment construction. A test embankment constructed using a 50/50 mixture, by volume, of tire shreds and sand was instrumented and monitored to: (a) determine total and differential settlements; (b) evaluate the environmental impact of the embankment construction on the groundwater quality due to leaching of fill material; and (c) study the temperature variation inside the embankment. The findings in this research indicate that mixtures of tire shreds and sand are viable materials for embankment construction. PMID:16343890

  13. Oscillons and domain walls

    SciTech Connect

    Hindmarsh, Mark; Salmi, Petja

    2008-05-15

    Oscillons, extremely long-lived localized oscillations of a scalar field, are shown to be produced by evolving domain wall networks in {phi}{sup 4} theory in two spatial dimensions. We study the oscillons in frequency space using the classical spectral function at zero momentum, and obtain that the velocity distribution is suppressed as {gamma}{sup -2} at large Lorentz factor {gamma}, with oscillons produced up to at least {gamma}{approx}10. This leads us to speculate that oscillons are produced at cusps, regions of the domain wall travelling near the speed of light. In order to gain some insight onto the dilute oscillon 'gas' produced by the domain walls, we prepare a denser gas by filling the simulation volume with oscillons boosted in random directions. We finish the study by revisiting collisions between oscillons and between an oscillon and a domain wall, showing that in the latter case they can pass straight through with minimal distortion.

  14. Railway Embankments as New Habitat for Pollinators in an Agricultural Landscape

    PubMed Central

    Moroń, Dawid; Skórka, Piotr; Lenda, Magdalena; Rożej-Pabijan, Elżbieta; Wantuch, Marta; Kajzer-Bonk, Joanna; Celary, Waldemar; Mielczarek, Łukasz Emil; Tryjanowski, Piotr

    2014-01-01

    Pollinating insect populations, essential for maintaining wild plant diversity and agricultural productivity, rely on (semi)natural habitats. An increasing human population is encroaching upon and deteriorating pollinator habitats. Thus the population persistence of pollinating insects and their associated ecosystem services may depend upon on man-made novel habitats; however, their importance for ecosystem services is barely understood. We tested if man-made infrastructure (railway embankments) in an agricultural landscape establishes novel habitats that support large populations of pollinators (bees, butterflies, hoverflies) when compared to typical habitats for these insects, i.e., semi-natural grasslands. We also identified key environmental factors affecting the species richness and abundance of pollinators on embankments. Species richness and abundance of bees and butterflies were higher for railway embankments than for grasslands. The occurrence of bare (non-vegetated) ground on embankments positively affected bee species richness and abundance, but negatively affected butterfly populations. Species richness and abundance of butterflies positively depended on species richness of native plants on embankments, whereas bee species richness was positively affected by species richness of non-native flowering plants. The density of shrubs on embankments negatively affected the number of bee species and their abundance. Bee and hoverfly species richness were positively related to wood cover in a landscape surrounding embankments. This is the first study showing that railway embankments constitute valuable habitat for the conservation of pollinators in farmland. Specific conservation strategies involving embankments should focus on preventing habitat deterioration due to encroachment of dense shrubs and maintaining grassland vegetation with patches of bare ground. PMID:25054427

  15. Engaging and Retaining Abused Women in Perinatal Home Visitation Programs

    PubMed Central

    Alhusen, Jeanne L.; Bullock, Linda; Bhandari, Shreya; Ghazarian, Sharon; Udo, Ifeyinwa E.; Campbell, Jacquelyn

    2013-01-01

    OBJECTIVES: Intimate partner violence (IPV) during pregnancy affects 0.9% to 17% of women and affects maternal health significantly. The impact of IPV extends to the health of children, including an increased risk of complications during pregnancy and the neonatal period, mental health problems, and cognitive delays. Despite substantial sequelae, there is limited research substantiating best practices for engaging and retaining high-risk families in perinatal home visiting (HV) programs, which have been shown to improve infant development and reduce maltreatment. METHODS: The Domestic Violence Enhanced Home Visitation Program (DOVE) is a multistate longitudinal study testing the effectiveness of a structured IPV intervention integrated into health department perinatal HV programs. The DOVE intervention, based on an empowerment model, combined 2 evidence-based interventions: a 10-minute brochure-based IPV intervention and nurse home visitation. RESULTS: Across all sites, 689 referrals were received from participating health departments. A total of 339 abused pregnant women were eligible for randomization; 42 women refused, and 239 women were randomly assigned (124 DOVE; 115 usual care), resulting in a 71% recruitment rate. Retention rates from baseline included 93% at delivery, 80% at 3 months, 76% at 6 months, and 72% at 12 months. CONCLUSIONS: Challenges for HV programs include identifying and retaining abused pregnant women in their programs. DOVE strategies for engaging and retaining abused pregnant women should be integrated into HV programs’ federal government mandates for the appropriate identification and intervention of women and children exposed to IPV. PMID:24187115

  16. Summary report on the design of the retained gas sampler system (retained gas sampler, extruder and extractor)

    SciTech Connect

    Wootan, D.W.; Bolden, R.C.; Bridges, A.E.; Cannon, N.S.; Chastain, S.A.; Hey, B.E.; Knight, R.C.; Linschooten, C.G.; Pitner, A.L.; Webb, B.J.

    1994-09-29

    This document summarizes work performs in Fiscal Year 1994 to develop the three main components of Retained Gas Sampler System (RGSS). These primary components are the Retained Gas Sampler (RGS), the Retained Gas Extruder (RGE), and the Retained Gas Extractor (RGEx). The RGS is based on the Westinghouse Hanford Company (WHC) Universal Sampler design, and includes modifications to reduce gas leakage. The primary data priorities for the RGSS are to measure the void fraction and the flammable gas concentration in the waste sample. Significant progress has been made in developing the RGSS. The RGSS is being developed by WHC to extract a representative waste sample from a Flammable Gas Watch List Tanks and to measure both the amount and composition of free and {open_quotes}bound{close_quotes} gases. Sudden releases of flammable gas mixtures are a safety concern for normal waste storage operations and eventual waste retrieval. Flow visualization testing was used to identify important fluid dynamic issues related to the sampling process. The primary data priorities for the RGSS are to measure the void fraction and the flammable gas concentration in the waste sample. The safety analysis for the RGSS is being performed by Los Alamos National Laboratory and is more than sixty percent (60%) complete.

  17. Computation of the seismic stability of earth retaining structures

    SciTech Connect

    1998-07-30

    The purpose of this CRADA project was to evaluate the seismic stability of block retaining wall systems. Retaining wall systems are used extensively in private and commercial developments. This study was designed to develop and demonstrate a computer modeling technology to be used to predict the seismic stability of any block wall system design. The nonlinear finite element computer programs developed at LLNL and employed in the Computational Earthquake Initiative were utilized in this small business CRADA to analyze the seismic stability of the block retaining walls. The unique capability of the LLNL programs to rigorously model frictional contact in a dynamic analysis problem were used in a computer simulation of the dynamic interaction the block wall/soil systems under seismic excitation. Another important application, and the focus of the proposal, was the use of block retaining walls in highway transportation systems to provide a vertical wall to hold back a mass of soil near highway bridges, and at on-ramps and off-ramps. Block retaining walls offered the potential of highway retaining wall construction which was both more flexible and more economical than existing poured-in-place and tilt-up highway retaining wall construction. However, block retaining wall technology was not embraced and utilized in the State of California as a result of seismic stability concerns expressed by Caltrans. Caltrans had an interest in utilizing block wall systems as soil retaining systems for major highway structures in California, but they stated to the block wall manufacturers and the manufacturer's engineering consultants that block retaining walls could not be employed until Caltrans was convinced of the earthquake stability of such systems.

  18. Decorin and biglycan retain LDL in disease-prone valvular and aortic subendothelial intimal matrix

    PubMed Central

    Neufeld, Edward B.; Zadrozny, Leah M.; Phillips, Darci; Aponte, Angel; Yu, Zu-Xi; Balaban, Robert S.

    2014-01-01

    Objective Subendothelial LDL retention by intimal matrix proteoglycans is an initial step in atherosclerosis and calcific aortic valve disease. Herein, we identify decorin and biglycan as the proteoglycans that preferentially retain LDL in intimal matrix at disease-prone sites in normal valve and vessel wall. Methods The porcine aortic valve and renal artery ostial diverter, initiation sites of calcific valve disease and renal atherosclerosis, respectively, from normal non-diseased animals were used as models in these studies. Results Fluorescent human LDL was selectively retained on the lesion-prone collagen/proteoglycan-enriched aortic surface of the valve, where the elastic lamina is depleted, as previously observed in lesion-prone sites in the renal ostium. iTRAQ mass spectrometry of valve and diverter protein extracts identified decorin and biglycan as the major subendothelial intimal matrix proteoglycans electrostatically retained on human LDL affinity columns. Decorin levels correlated with LDL binding in lesion-prone sites in both tissues. Collagen binding to LDL was shown to be proteoglycan-mediated. All known basement membrane proteoglycans bound LDL suggesting they may modulate LDL uptake into the subendothelial matrix. The association of purified decorin with human LDL in an in vitro microassay was blocked by serum albumin and heparin suggesting anti-atherogenic roles for these proteins in vivo. Conclusions LDL electrostatic interactions with decorin and biglycan in the valve leaflets and vascular wall is a major source of LDL retention. The complementary electrostatic sites on LDL or these proteoglycans may provide a novel therapeutic target for preventing one of the earliest events in these cardiovascular diseases. PMID:24529131

  19. Bicruciate retaining

    PubMed Central

    2016-01-01

    Total knee replacement (TKR) is a procedure used to treat knee arthropathy. Patients’ dissatisfaction is still relevant (literature reports dissatisfaction rates as high as 40%). The anterior cruciate ligament is usually removed while performing a total knee arthroplasty, thus changing knee biomechanics. As patients’ mean age to surgery is decreasing, bicruciate retaining models, which preserve normal biomechanics, may be useful in increasing patients’ outcomes. Limited data concerning bicruciate retaining arthroplasty is available; although clinical results are encouraging, there are concerns regarding surgical exposure, anterior cruciate integrity evaluation, and implant fixation. PMID:27162778

  20. Autolysis and extension of isolated walls from growing cucumber hypocotyls

    NASA Technical Reports Server (NTRS)

    Cosgrove, D. J.; Durachko, D. M.

    1994-01-01

    Walls isolated from cucumber hypocotyls retain autolytic activities and the ability to extend when placed under the appropriate conditions. To test whether autolysis and extension are related, we treated the walls in various ways to enhance or inhibit long-term wall extension ('creep') and measured autolysis as release of various saccharides from the wall. Except for some non-specific inhibitors of enzymatic activity, we found no correlation between wall extension and wall autolysis. Most notably, autolysis and extension differed strongly in their pH dependence. We also found that exogenous cellulases and pectinases enhanced extension in native walls, but when applied to walls previously inactivated with heat or protease these enzymes caused breakage without sustained extension. In contrast, pretreatment of walls with pectinase or cellulase, followed by boiling in methanol to inactivate the enzymes, resulted in walls with much stronger expansin-mediated extension responses. Crude protein preparations from the digestive tracts of snails enhanced extension of both native and inactivated walls, and these preparations contained expansin-like proteins (assessed by Western blotting). Our results indicate that the extension of isolated cucumber walls does not depend directly on the activity of endogenous wall-bound autolytic enzymes. The results with exogenous enzymes suggest that the hydrolysis of matrix polysaccharides may not induce wall creep by itself, but may act synergistically with expansins to enhance wall extension.

  1. Identification and behavior of label-retaining cells in epithelia

    SciTech Connect

    Bickenbach, J.R.

    1982-01-01

    A subpopulation of stem cells has been demonstrated in several renewing tissues. Such cells have a slow cell cycle and provide differentiating cells during normal turnover and during regeneration of the tissue following damage. The presence of slowly-cycling cells in epithelia from regions of skin and oral mucosa was examined by labeling 10-day-old mice and 5-day-old hamsters with tritiated thymidine (/sup 3/H-TdR) and observing the rate at which label was diluted from the basal cells. Label was rapidly diluted by cell division in most cells but a small percentage of basal cells (label-retaining cells, LRCS) was found to retain label for up to ninety days. Electron microscopic autoradiography and ..beta..-glucuronidase histochemistry with autoradiography were used to distinguish slowly-cycling keratinocytes from Langerhans cells. Such findings of slowly-cycling keratinocytes in epithelia with the ability to proliferate in culture and with a direct relationship to patterns of tissue architecture suggest that LRCs in epithelia correspond to stem cells described in other continuously renewing tissues.

  2. Three-Dimensional Dynamic Analyses of Track-Embankment-Ground System Subjected to High Speed Train Loads

    PubMed Central

    2014-01-01

    A three-dimensional finite element model was developed to investigate dynamic response of track-embankment-ground system subjected to moving loads caused by high speed trains. The track-embankment-ground systems such as the sleepers, the ballast, the embankment, and the ground are represented by 8-noded solid elements. The infinite elements are used to represent the infinite boundary condition to absorb vibration waves induced by the passing of train load at the boundary. The loads were applied on the rails directly to simulate the real moving loads of trains. The effects of train speed on dynamic response of the system are considered. The effect of material parameters, especially the modulus changes of ballast and embankment, is taken into account to demonstrate the effectiveness of strengthening the ballast, embankment, and ground for mitigating system vibration in detail. The numerical results show that the model is reliable for predicting the amplitude of vibrations produced in the track-embankment-ground system by high-speed trains. Stiffening of fill under the embankment can reduce the vibration level, on the other hand, it can be realized by installing a concrete slab under the embankment. The influence of axle load on the vibration of the system is obviously lower than that of train speed. PMID:24723838

  3. Wall thickness measuring method and apparatus

    DOEpatents

    Salzer, L.J.; Bergren, D.A.

    1987-10-06

    An apparatus for measuring the wall thickness of a nonmagnetic article having a housing supporting a magnet and a contiguous supporting surface. The tubular article and the housing are releasably secured to the supporting surface and a support member of an optical comparator, respectively. To determine the wall thickness of the article at a selected point, a magnetically responsive ball is positioned within the tubular article over said point and retained therein by means of a magnetic field produced by the magnet. Thereafter, an optical comparator is employed to project a magnified image of the ball on a screen and the wall thickness at the selected point is calculated by using a ball surface measurement taken with the comparator in conjunction with a previously determined base line measurement.

  4. Wall thickness measuring method and apparatus

    DOEpatents

    Salzer, Leander J.; Bergren, Donald A.

    1989-01-01

    An apparatus for measuring the wall thickness of a nonmagnetic article having a housing supporting a magnet and a contiguous supporting surface. The tubular article and the housing are releasably secured to the supporting surface and a support member of an optical comparator, respectively. To determine the wall thickness of the article at a selected point, a magnetically responsive ball is positioned within the tubular article over said point and retained therein by means of a magnetic field produced by the magnet. Thereafter, an optical comparator is employed to project a magnified image of the ball on a screen and the wall thickness at the selected point is calculated by using a ball surface measurement taken with the comparator in conjunction with a previously determined base line measurement.

  5. Modeling of hydrologic conditions and solute movement in processed oil shale waste embankments under simulated climatic conditions. Final report, November 1995

    SciTech Connect

    1995-12-31

    A study is described on the hydrological and geotechnical behavior of an oil shale solid waste. The objective was to obtain information which can be used to assess the environmental impacts of oil shale solid waste disposal in the Green River Basin. The spent shale used in this study was combusted by the Lurgi-Ruhrgas process by Rio Blanco Oil Shale Company, Inc. Laboratory bench-scale testing included index properties, such as grain size distribution and Atterberg limits, and tests for engineering properties including hydraulic conductivity and shear strength. Large-scale tests were conducted on model spent shale waste embankments to evaluate hydrological response, including infiltration, runoff, and seepage. Large-scale tests were conducted at a field site in western Colorado and in the Environmental Simulation Laboratory (ESL)at the University of Wyoming. The ESL tests allowed the investigators to control rainfall and temperature, providing information on the hydrological response of spent shale under simulated severe climatic conditions. All experimental methods, materials, facilities, and instrumentation are described in detail, and results are given and discussed. 34 refs.

  6. Modeling of hydrologic conditions and solute movement in processed oil shale waste embankments under simulated climatic conditions. Third quarterly report, April 1993--June 1993

    SciTech Connect

    Reeves, T.L.; Turner, J.P.; Rangarajan, S.; Skinner, Q.D.; Hasfurther, V.

    1993-08-11

    This report presents research objectives, discusses activities, and presents technical progress for the period April 1, 1993 through June 31, 1993 on Contract No. DE-FC21-86LC11084 with the Department of Energy, Laramie Project Office. The scope of the research program and the continuation is to study interacting hydrologic, geotechnical, and chemical factors affecting the behavior and disposal of combusted processed oil shale. The research combines bench-scale testing with large scale research sufficient to describe commercial scale embankment behavior. The large scale approach was accomplished by establishing five lysimeters, each 7.3 {times} 3.0 {times} 3.0 m deep, filled with processed oil shale that has been retorted and combusted by the Lurgi-Ruhrgas (Lurgi) process. Approximately 400 tons of Lurgi processed oil shale waste was provided by Rio Blanco Oil Shale Co., Inc. (RBOSC) through a separate cooperative agreement with the University of Wyoming (UW) to carry out this study. Three of the lysimeters were established at the RBOSC Tract C-a in the Piceance Basin of Colorado. Two lysimeters were established in the Environmental Simulation Laboratory (ESL) at UW. The ESL was specifically designed and constructed so that a large range of climatic conditions could be physically applied to the processed oil shale which was filled in the lysimeter cells.

  7. Modeling of hydrologic conditions and solute movement in processed oil shale waste embankments under simulated climatic conditions. Second quarterly report, January 1, 1992--March 31, 1992

    SciTech Connect

    Turner, J.P.; Hasfurther, V.

    1992-05-04

    The scope of the research program and the continuation is to study interacting hydrologic, geotechnical, and chemical factors affecting the behavior and disposal of combusted processed oil shale. The research combines bench-scale testing with large scale research sufficient to describe commercial scale embankment behavior. The large scale approach was accomplished by establishing five lysimeters, each 7.3 {times} 3.0 {times} 3.0 m deep, filled with processed oil shale that has been retorted and combusted by the Lurgi-Ruhrgas (Lurgi) process. Approximately 400 tons of Lurgi processed oil shale waste was provided by Rio Blanco Oil Shale Co., Inc. (RBOSC) through a separate cooperative agreement with the University of Wyoming (UW) to carry out this study. Three of the lysimeters were established at the RBOSC Tract C-a in the Piceance Basin of Colorado. Two lysimeters were established in the Environmental Simulation Laboratory (ESL) at UW. The ESL was specifically designed and constructed so that a large range of climatic conditions could be physically applied to the processed oil shale which was filled in the lysimeter cells.

  8. Reaching (and retaining) Broader Audiences in Citizen Science.

    NASA Astrophysics Data System (ADS)

    Cavalier, D.

    2015-12-01

    Individuals come to citizen science from different perspectives and preferences, and engage in a wide range of projects from data collection to public policy (Irwin 1995, Bonney et al. 2009a). Many participate exclusively online in crowdsourcing projects such as Galaxy Zoo, Fold-It, and Eyewire. Hundreds of thousands gather data on-the-ground for academic andcommunity research projects led by scientists at universities, government agencies/NGOs, and nonprofits. Untold others initiate their own projects in response to local environmental and health issues. All types of citizen science endeavors face challenges around data access and management, around relationships with scientists and project managers, and around making their scientific accomplishments visible as they accumulate over time. Among the most universal and ongoing challenges for all types of citizen science, however, "is attracting and retaining enough participants to make achievement of project goals possible." (Crowston and Prestopnik One known reason for this issue is the reality that individual projects and project types exist in "silos" - as self-segregated groups with particular shared interests (Dickinson et al. 2010). What efforts can be made in digital infrastructures and community building efforts to enable the unprecedented ability to support and retain diverse types of citizen science participation and data exchange between communities? How do we support participation in, and management of, multiple projects; continuity in, and sharing of, a broad and accessible citizen science community; and related social components? This presentation will provide a brief overview of the known barriers to this "utopia" and a snapshot of efforts underway to address many of these barriers.

  9. Application of sewage sludge compost on highway embankments.

    PubMed

    Pengcheng, Gao; Xinbao, Tang; Yanan, Tong; Yingxu, Chen

    2008-01-01

    More and more sewage sludge is being produced in China. Safe and economical methods for sewage sludge disposal should be found considering the increase in sewage treatment. In order to verify the feasibility of sludge disposal on newly built highway embankments, five treatments (0, 15, 30, 60 and 120 tons ha(-1)) of sewage sludge compost (SSC) were added to a silty-clay embankment soil on the Xi-Huang highway. The results showed that amendment with SSC increased soil available N, available P, organic matter, cation exchange capacity, and water content, and decreased soil bulk density. Application of SSC enhanced ryegrass growth and reduced runoff and soil erosion. Heavy metal losses from sediments in runoff remained constant or decreased relative to the control until a rate of 60 tons ha(-1) was exceeded, when heavy metal losses appeared to increase. PMID:17910912

  10. Hader bar and clip attachment retained mandibular complete denture

    PubMed Central

    Singh, Kunwarjeet; Gupta, Nidhi; Kapoor, Vikram; Gupta, Ridhimaa

    2013-01-01

    Bar and clip attachments significantly improve the level of satisfaction of denture-wearing patients by enhancing the retention and stability of the prosthesis. These attachments have been most commonly used for connecting the prosthesis to implants, but they can be effectively used to retain tooth-supported prosthesis as well. The primary functions of bar attachments are splinting the abutments together, even distribution of forces to the abutments and supporting areas, guiding the prosthesis into place, improving the retention, stability, support and comfort of the patient. The primary requirement for the use of bar attachments is the availability of sufficient vertical and buccolingual space for the proper placement of the bar, sleeves, teeth arrangement and sufficient thickness of acrylic denture base to minimise incidence of denture fracture in the area of bar assembly. PMID:24145505

  11. Recruiting and Retaining Arab Muslim Mothers and Children for Research

    PubMed Central

    Aroian, Karen J.; Katz, Anne; Kulwicki, Anahid

    2006-01-01

    Purpose To describe successful and not-so-successful strategies for recruiting and retaining Arab Muslim immigrant women and their adolescent children for research. Design and Methods A longitudinal study of mother-child adjustment of Arab immigrants to the US is used for illustration. A panel of experts was assembled and provided culturally specific advice about gatekeepers, advertising, data collectors, data collection, and how to track and encourage participation at subsequent time points in the study. Findings Most of the strategies recommended by the panel were overwhelmingly positive, including advice about data collectors, how to collect data, financial incentives, avoiding offending families, and personal contacts. Hiring data collectors who were able to establish personal and culturally appropriate relationships with study participants was the single most successful recruitment and retention strategy. Advice from cultural experts about which gatekeepers to engage and how to advertise for study participants was not productive. Conclusions Researchers should not only assemble a panel of cultural experts to provide advice about group specific strategies to build trust and maintain cultural sensitivity, but also to budget generously for time for data collectors to build and maintain rapport with study populations who, like Arab immigrant women, highly value personal relationships. PMID:17044343

  12. Best Practices for Recruiting and Retaining Women in Physics.

    NASA Astrophysics Data System (ADS)

    Murnane, Margaret

    2007-04-01

    Universities make a tremendous investment in faculty, often recruiting and hiring them at great expense. These faculty have highly specialized talents that are needlessly wasted when faculty spend time struggling in a bad environment, or leaving the university. Therefore, there is a great incentive to improve the working environment for female faculty. This talk will highlight specific strategies that departments can use to recruit and retain the best faculty, including female faculty. These strategies have been developed over several years of site visits by the APS Committee on the Status of Women in Physics to physics departments around the US. The mark of a successful departmental climate for women is one in which the enthusiasm and ambition of the women undergraduates is transformed smoothly into successful and ambitious women graduate students, with dynamic, forging-ahead female postdocs, energetic junior women faculty, and productive, happy, senior women faculty who all serve as positive role models.

  13. Dynamic interaction analysis of trains moving on embankments during earthquakes

    NASA Astrophysics Data System (ADS)

    Ju, S. H.; Li, H. C.

    2011-10-01

    This study developed a time-domain finite element method to simulate the derailment of trains moving on embankments under seismic loading. The finite element mesh included trains, rails, embankment foundation, soil, and the absorbing boundary condition, where the seismic displacements were applied at the bottom of the mesh. For the cases of a perfectly smooth rail with or without seismic loading, the train derailment coefficients are almost independent of train speeds. However, with minor rail irregularities, they are highly dependent on train speeds. This study also shows that the resonance between the train and earthquake plays an important role in train derailment. The maximum derailment coefficients are quite linear in proportion to the peak ground acceleration (PGA) of the earthquake, if the structural behaviors and dynamic soil properties are not nonlinear.

  14. 7. VIEW WEST ALONG THE UPSTREAM SLOPE OF THE EMBANKMENT, ...

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

    7. VIEW WEST ALONG THE UPSTREAM SLOPE OF THE EMBANKMENT, SHOWING ROCK PAVING IN PROGRESS.... Volume XIX, No. 7, June 24, 1940. - Prado Dam, Embankment, Santa Ana River near junction of State Highways 71 & 91, Corona, Riverside County, CA

  15. Earth melter with rubble walls and method of use

    DOEpatents

    Chapman, Chris C.

    1998-01-01

    The present invention is an improvement to the earth melter described and claimed in U.S. Pat. No. 5,443,618. The improvement is the use of rubble for retaining walls. More specifically, the retaining walls rest on ground level and extend above ground level piling rubble around a melt zone. A portion of the melter may be below grade wherein sidewalls are formed by the relatively undisturbed native soil or rock, and the rubble may be used as a backfill liner for the below grade sidewalls.

  16. Retaining Device For One-Piece Battery

    DOEpatents

    Gilabert, Claude; Leturque, Michel; Verhoog, Roclof

    2000-08-01

    The present invention consists of a device for retaining a one-piece battery with a prismatic casing having two longitudinal walls and two transverse walls. The device contains two plates applied to respective transverse walls and at least one cinching mechanism for the plates consisting of at least one flat strip closed on itself surrounding the longitudinal walls and the transverse walls are provided with the plates. The device is characterized in that at least one of the plates contains at least one recessed housing and the strip closely follows the shape of the housing.

  17. Grass plants bind, retain, uptake, and transport infectious prions.

    PubMed

    Pritzkow, Sandra; Morales, Rodrigo; Moda, Fabio; Khan, Uffaf; Telling, Glenn C; Hoover, Edward; Soto, Claudio

    2015-05-26

    Prions are the protein-based infectious agents responsible for prion diseases. Environmental prion contamination has been implicated in disease transmission. Here, we analyzed the binding and retention of infectious prion protein (PrP(Sc)) to plants. Small quantities of PrP(Sc) contained in diluted brain homogenate or in excretory materials (urine and feces) can bind to wheat grass roots and leaves. Wild-type hamsters were efficiently infected by ingestion of prion-contaminated plants. The prion-plant interaction occurs with prions from diverse origins, including chronic wasting disease. Furthermore, leaves contaminated by spraying with a prion-containing preparation retained PrP(Sc) for several weeks in the living plant. Finally, plants can uptake prions from contaminated soil and transport them to aerial parts of the plant (stem and leaves). These findings demonstrate that plants can efficiently bind infectious prions and act as carriers of infectivity, suggesting a possible role of environmental prion contamination in the horizontal transmission of the disease. PMID:25981035

  18. Grass plants bind, retain, uptake and transport infectious prions

    PubMed Central

    Pritzkow, Sandra; Morales, Rodrigo; Moda, Fabio; Khan, Uffaf; Telling, Glenn C.; Hoover, Edward; Soto, Claudio

    2015-01-01

    Prions are the protein-based infectious agents responsible for prion diseases. Environmental prion contamination has been implicated in disease transmission. Here we analyzed the binding and retention of infectious prion protein (PrPSc) to plants. Small quantities of PrPSc contained in diluted brain homogenate or in excretory materials (urine and feces) can bind to wheat grass roots and leaves. Wild type hamsters were efficiently infected by ingestion of prion-contaminated plants. The prion-plant interaction occurs with prions from diverse origins, including chronic wasting disease. Furthermore, leaves contaminated by spraying with a prion-containing preparation retained PrPSc for several weeks in the living plant. Finally, plants can uptake prions from contaminated soil and transport them to aerial parts of the plant (stem and leaves). These findings demonstrate that plants can efficiently bind infectious prions and act as carriers of infectivity, suggesting a possible role of environmental prion contamination in the horizontal transmission of the disease. PMID:25981035

  19. Lead poisoning from retained bullets. Pathogenesis, diagnosis, and management.

    PubMed Central

    Linden, M A; Manton, W I; Stewart, R M; Thal, E R; Feit, H

    1982-01-01

    Lead intoxication (plumbism) from retained bullets has rarely been reported but may be fatal if unrecognized. Bullets lodged within joint spaces or pseudocysts are more likely to develop this complication, although patients with retained missiles in other locations may also be at risk. Subtle findings such as the occurrence of unexplained anemia, abdominal colic, nephropathy, or neurologic deterioration in patients with retained missiles may suggest consideration of plumbism. An intercurrent metabolic stress such as infection, endocrinopathy, or alcoholism may be a precipitating factor. Among the various diagnostic studies available, mass spectrometric stable isotope dilution analysis may be the most reliable. It is important to employ chelation therapy prior to any operative intervention. This will reduce the mobilization of lead from bone during or following the surgical procedure. Images Fig. 1. Fig. 3. Fig. 5. PMID:6800314

  20. Typical Window, Interior Wall Paint Sequence, Wall Section, and Foundation ...

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

    Typical Window, Interior Wall Paint Sequence, Wall Section, and Foundation Sections - Civilian Conservation Corps (CCC) Camp NP-5-C, Barracks No. 5, CCC Camp Historic District at Chapin Mesa, Cortez, Montezuma County, CO

  1. Leading a multigenerational workforce: strategies for attracting and retaining millennials.

    PubMed

    Cahill, Terrence F; Sedrak, Mona

    2012-01-01

    Over the past several years, leaders in healthcare have noticed an increase in generational tension among employees, most often focused on the attitudes and behaviors of the arriving millennials (generation Y). While these employee relations issues were a nuisance, they rarely rose to the level of a priority demanding leadership intervention. Some leaders, in fact, hoped that the issues would resolve themselves as these young employees settled in and learned that they had to demonstrate new behaviors to be successful in the workplace. Most organizations adopted this wait-and-see attitude. Not so today. As the boomer generation has begun its exodus from the workplace, organizations are increasingly looking at the millennials as not a problem but a solution to the workplace manpower transition that is under way. Our problem is that we don't yet know how best to lead such a diverse, multigenerational workforce. This article examines the generational topic and provides advice concerning a variety of changes that leaders may implement to advance their organization's ability to attract and to retain the millennials. PMID:23050333

  2. Design principles for engaging and retaining virtual citizen scientists.

    PubMed

    Wald, Dara M; Longo, Justin; Dobell, A R

    2016-06-01

    Citizen science initiatives encourage volunteer participants to collect and interpret data and contribute to formal scientific projects. The growth of virtual citizen science (VCS), facilitated through websites and mobile applications since the mid-2000s, has been driven by a combination of software innovations and mobile technologies, growing scientific data flows without commensurate increases in resources to handle them, and the desire of internet-connected participants to contribute to collective outputs. However, the increasing availability of internet-based activities requires individual VCS projects to compete for the attention of volunteers and promote their long-term retention. We examined program and platform design principles that might allow VCS initiatives to compete more effectively for volunteers, increase productivity of project participants, and retain contributors over time. We surveyed key personnel engaged in managing a sample of VCS projects to identify the principles and practices they pursued for these purposes and led a team in a heuristic evaluation of volunteer engagement, website or application usability, and participant retention. We received 40 completed survey responses (33% response rate) and completed a heuristic evaluation of 20 VCS program sites. The majority of the VCS programs focused on scientific outcomes, whereas the educational and social benefits of program participation, variables that are consistently ranked as important for volunteer engagement and retention, were incidental. Evaluators indicated usability, across most of the VCS program sites, was higher and less variable than the ratings for participant engagement and retention. In the context of growing competition for the attention of internet volunteers, increased attention to the motivations of virtual citizen scientists may help VCS programs sustain the necessary engagement and retention of their volunteers. PMID:26365126

  3. Attracting and retaining GPs: a stakeholder survey of priorities

    PubMed Central

    Lorant, Vincent; Geerts, Charlotte; Duchesnes, Christiane; Goedhuys, Jo; Ryssaert, Lynn; Remmen, Roy; D'hoore, William

    2011-01-01

    Background Despite being a key player in the healthcare system, training and practising general practice has become less attractive in many countries and is in need of reform. Aim To identify political priorities for improving GPs' attraction to the profession and their retention within it. Design and setting Stakeholder face-to-face survey in Belgium, 2008. Method A total of 102 key stakeholders were recruited from policymakers, professional groups, academia, GP leaders, and the media. All interviewees were asked to score 23 policies on four criteria: effectiveness in attracting and retaining GPs, cost to society, acceptance by other health professionals, and accessibility of care. An overall performance score was computed (from –3 to +3) for each type of policy — training, financing, work–life balance, practice organisation, and governance — and for innovative versus conservative policies. Results Practice organisation policies and training policies received the highest scores (mean score ≥1.11). Financing policies, governance, and work–life balance policies scored poorly (mean score ≤0.65) because they had negative effects, particularly in relation to cost, acceptance, and accessibility of care. Stakeholders were keen on moving GPs towards team work, improving their role as care coordinator, and helping them to offload administrative tasks (score ≥1.4). They also favoured moves to increase the early and integrated exposure of all medical students to general practice. Overall, conservative policies were better scored than innovative ones (beta = –0.16, 95% confidence interval = –0.28 to –0.03). Conclusion The reforming of general practice is made difficult by the small-step approach, as well as the importance of decision criteria related to cost, acceptance, and access. PMID:21722449

  4. Webinar: Stepped chute design for embankment dams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Changing demographics in the vicinity of dams have led to hazard creep in a number of dams worldwide. Many of these dams now have insufficient spillway capacity as a result of these changes in hazard classification from low to significant or high hazard. Stepped chutes applied to the embankment da...

  5. Inception point for embankment dam stepped spillways

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stepped spillways applied to embankment dams have become a common design practice with the rehabilitation of aging watershed dams, especially those experiencing a hazard classification change from low to high hazard. Previous research on stepped spillways focused on gravity dams where aerated flow ...

  6. Method for residual stress relief and retained austenite destabilization

    DOEpatents

    Ludtka, Gerard M.

    2004-08-10

    A method using of a magnetic field to affect residual stress relief or phase transformations in a metallic material is disclosed. In a first aspect of the method, residual stress relief of a material is achieved at ambient temperatures by placing the material in a magnetic field. In a second aspect of the method, retained austenite stabilization is reversed in a ferrous alloy by applying a magnetic field to the alloy at ambient temperatures.

  7. A Geomorphic Analysis of Floodplain Lakes along the Embanked Lower Mississippi River for Managing Hydrologic Connectivity

    NASA Astrophysics Data System (ADS)

    Hudson, Paul; Boot, Dax; Sounny-Slitinne, M. Anwar; Kristensen, Kristiaan

    2015-04-01

    A Geomorphic Analysis of Floodplain Lakes along the Embanked Lower Mississippi River for Managing Hydrologic Connectivity Floodplain lakes are vital to the environmental integrity of lowland rivers. Embankment by levees (dikes) for flood control greatly reduces the size of lowland floodplains and is detrimental to the quality and functioning of floodplain water bodies, presenting a challenge to government agencies charged with environmental management. The embanked floodplain of the Lower Mississippi River is an enormous surface which includes a variety of lake types formed by geomorphic and anthropogenic processes. While much is known about the channel and hydrologic regime, very little is known about the physical structure and functioning of the embanked floodplain of the lower Mississippi. Importantly, management agencies do not have an inventory of the basic characteristics (e.g., type, frequency, location, size, shape) of water bodies within the lower Mississippi embanked floodplain. An analysis of lakes along the Lower Mississippi River embanked floodplain is performed by utilizing the National Hydrographic Dataset (NHD) from the U.S. Geological Survey, a LiDAR digital elevation model (DEM), as well as streamflow data from the USGS. The vector NHD data includes every official mapped water body (blue line polygons) on USGS topographic maps at scales of 1:100,000 and 1:24,000. Collectively, we identify thousands of discreet water bodies within the embanked floodplain. Utilizing planimetric properties the water bodies were classified into the following lake types: cutoffs (neck and chute), sloughs, crevasse (scour), local drainage (topographic), and borrow pits. The data is then statistically analyzed to examine significant differences in the spatial variability in lake types along the entire lower Mississippi embanked floodplain in association with geomorphic divisions and hydrologic regime. The total embanked floodplain area of the LMR is 7,303 km2,. The total

  8. Retainer for laboratory animals

    NASA Technical Reports Server (NTRS)

    Lee, R. W.

    1979-01-01

    Bio-retainer holds laboratory animals in fixed position for research and clinical experiments. Retainer allows full access to animals and can be rapidly opened and closed to admit and release specimens.

  9. Retaining and transferring nursing knowledge through a hospital internship program.

    PubMed

    Murphy, Mary; Petryshen, Patricia; Read, Nancy

    2004-05-01

    In healthcare, organizations recognize that human capital is their most valuable asset. The importance of investing in knowledge workers is imperative given the current and future shortage of health professionals. Knowledge acquisition occurs through continuous learning and the transfer of information from those who are highly experienced to those who are less qualified. At St. Michael's Hospital, two innovative and unique programs were created for the transfer of knowledge. The first was a nurse fellowship program that enabled experienced nurses to spend two to three months learning new skills to advance clinical practice. The second was a nurse internship program in which new graduates spend three to four months in their area of hire to enhance clinical practice through skill development and prioritization of patient care needs. This paper describes both programs and presents an evaluation of the new-graduate internship program as an opportunity for professional development and career enhancement For nurse interns, the program promotes self-esteem and professional confidence, improves job satisfaction and rewards nurses for their contribution. For nurse preceptors, the program provides job enrichment, experience in teaching and recognition by the organization and peers that they are knowledge experts. In healthcare, organizations have come to acknowledge that their most valuable asset is human capital, in particular, knowledge workers (Horibe 1999). Knowledge workers contribute a composite of information, intellectual property and experience (Horibe 1999), acquired by study, investigation, observation or practice (Webster's Dictionary 1989). Investing in knowledge workers is investing in the future. In this regard, organizations have implemented recruitment and retention strategies to attract, retain and advance the highest calibre of health professional. Knowledge workers contribute to an organization through their ideas, analyses of complex situations and sound

  10. Dynamical domain wall and localization

    NASA Astrophysics Data System (ADS)

    Toyozato, Yuta; Higuchi, Masafumi; Nojiri, Shin'ichi

    2016-03-01

    Based on the previous works (Toyozato et al., 2013 [24]; Higuchi and Nojiri, 2014 [25]), we investigate the localization of the fields on the dynamical domain wall, where the four-dimensional FRW universe is realized on the domain wall in the five-dimensional space-time. Especially we show that the chiral spinor can localize on the domain wall, which has not been succeeded in the past works as the seminal work in George et al. (2009) [23].

  11. Reconstruction of eroded and deposited sediment volumes in the floodplains of the embanked River Waal, the Netherlands, for the period 1650 - 1850 AD

    NASA Astrophysics Data System (ADS)

    Hobo, Noortje; Makaske, Bart; Middelkoop, Hans

    2010-05-01

    The embanked floodplains of the River Waal developed as a result of stepwise downstream migration of meander bends between confining dykes. Accretion in the upstream limb of the outer bend - enhanced by groynes and trees - and erosion in the downstream limb have resulted in a series of successively developed sand bars, separated by secondary channels. On top of the sand bars and the secondary channel fills, fine-grained overbank sediments were deposited. Downstream migration ceased around 1850 AD, when the river bed was fixed by large-scale construction of groynes, and only overbank deposition continued. Eroded and deposited sediment volumes associated with downstream migration are affected by human activities. Goal of the present research is to estimate a sediment budget for a 12-km-long section along the River Waal, by quantifying the amount of erosion and deposition. We estimated these volumes for time slices of 50 years, between 1650 and 1850 AD, in order to be able to assess the variable impact of human interference during this period. To estimate erosion, we created geomorphological maps for all time slices, based on maps dating from the 17th century to present. In these maps, distinction is made between sand bars, residual channels, and older deposits (all sediments deposited before 1650 AD). Comparison between all maps allowed us to calculate the eroded area per time slice. Eroded volumes were hence estimated by multiplying the eroded area by the average river depth at that period, which is assumed to be the erosion depth. For estimation of deposition we used lithological cross-sections. These cross-sections are positioned such that every sand bar and every residual channel is represented in at least one cross-section. In every cross-section isochrones were drawn, based on OSL datings, chronologic interpretation of heavy metal profiles, and the historical maps. These isochrones are used to calculate the thickness of the sand bars, the residual channel fills

  12. Systems and methods for retaining and removing irradiation targets in a nuclear reactor

    SciTech Connect

    Runkle, Gary A.; Matsumoto, Jack T.; Dayal, Yogeshwar; Heinold, Mark R.

    2015-12-08

    A retainer is placed on a conduit to control movement of objects within the conduit in access-restricted areas. Retainers can prevent or allow movement in the conduit in a discriminatory fashion. A fork with variable-spacing between prongs can be a retainer and be extended or collapsed with respect to the conduit to change the size of the conduit. Different objects of different sizes may thus react to the fork differently, some passing and some being blocked. Retainers can be installed in inaccessible areas and allow selective movement in remote portions of conduit where users cannot directly interface, including below nuclear reactors. Position detectors can monitor the movement of objects through the conduit remotely as well, permitting engagement of a desired level of restriction and object movement. Retainers are useable in a variety of nuclear power plants and with irradiation target delivery, harvesting, driving, and other remote handling or robotic systems.

  13. Fibre Bragg grating for flood embankment monitoring

    NASA Astrophysics Data System (ADS)

    Markowski, Konrad; Nevar, Stanislau; Dworzanski, Adam; Hackiewicz, Krzysztof; Jedrzejewski, Kazimierz

    2014-11-01

    In this article we present the preliminary studies for the flood embankment monitoring system based on the fibre Bragg gratings. The idea of the system is presented. The Bragg resonance shift is transformed to the change of the power detected by the standard InGaAs photodiode. The discrimination of the received power was executed by another fibre Bragg grating with different parameters. The project of the fully functional system is presented as well.

  14. Two-year survival analysis of twisted wire fixed retainer versus spiral wire and fiber-reinforced composite retainers: a preliminary explorative single-blind randomized clinical trial

    PubMed Central

    Sobouti, Farhad; Rakhshan, Vahid; Saravi, Mahdi Gholamrezaei; Zamanian, Ali

    2016-01-01

    Objective Traditional retainers (both metal and fiber-reinforced composite [FRC]) have limitations, and a retainer made from more flexible ligature wires might be advantageous. We aimed to compare an experimental design with two traditional retainers. Methods In this prospective preliminary clinical trial, 150 post-treatment patients were enrolled and randomly divided into three groups of 50 patients each to receive mandibular canine-to-canine retainers made of FRC, flexible spiral wire (FSW), and twisted wire (TW). The patients were monitored monthly. The time at which the first signs of breakage/debonding were detected was recorded. The success rates of the retainers were compared using chi-squared, Kaplan-Meier, and Cox proportional-hazard regression analyses (α = 0.05). Results In total, 42 patients in the FRC group, 41 in the FSW group, and 45 in the TW group completed the study. The 2-year failure rates were 35.7% in the FRC group, 26.8% in the FSW group, and 17.8% in the TW group. These rates differed insignificantly (chi-squared p = 0.167). According to the Kaplan-Meier analysis, failure occurred at 19.95 months in the FRC group, 21.37 months in the FSW group, and 22.36 months in the TW group. The differences between the survival rates in the three groups were not significant (Cox regression p = 0.146). Conclusions Although the failure rate of the experimental retainer was two times lower than that of the FRC retainer, the difference was not statistically significant. The experimental TW retainer was successful, and larger studies are warranted to verify these results. PMID:27019825

  15. VIEW OF EMBANKMENT ALONG SHERMAN AVE. FROM SOUTHEAST OF SHERMAN ...

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

    VIEW OF EMBANKMENT ALONG SHERMAN AVE. FROM SOUTHEAST OF SHERMAN & REYNOLDS AVENUES, LOOKING NORTH-NORTHWEST - Fort Leavenworth, Metropolitan Avenue & Seventh Street, Leavenworth, Leavenworth County, KS

  16. Impact of Geotechnical Factors on the Safety of Low Embankment Dams From the Perspective of Technical and Safety Supervision

    NASA Astrophysics Data System (ADS)

    Kasana, Andrej; Minárik, Marian; Nikolaj, Maroš

    2015-03-01

    Our research deals with a broad spectrum of problems concerning the variability of geotechnical factors and their influence on the safety of the biggest group of dam constructions in Slovakia, i.e., low earthfill dams. Its specific aim is the observation of their risk factors by using our experience and knowledge gained while working in the sector of technical and safety supervision. To achieve the aims of a research thesis, we analyzed 39 low earthfill dams. We performed observations and documented their conditions with the aim of clarifying the risk factors. After an analysis of the information materials that characterize dams and after a statistical analysis of the measurement results in situ, including measurements from technical and safety supervision databases, we performed an analysis by using mathematical modeling to evaluate the safety of the dam constructions. Out of the total number of 39 dam constructions, an analysis of the stability of the dam slopes was performed on 37 dams, and deformation problems were analyzed on 28 of the dams. Filtration problems were analyzed at 26 dams, and a complete evaluation of the intensity of filtration movements was performed on 19 of the constructions. On the basis of a detailed analysis of the 39 dam constructions, we specified their problems and the concomitant consequences of the problems. Geotechnical risk factors and specific risks that determine the safety of water constructions were characterized. The analysis confirmed the importance of an engineer-geological and geotechnical checkup in the process of preparation and building (alternatively, during reconstructions and sanitation work) of such water constructions and also the importance of monitoring in the process of dam usage. Technical and safety checkups were also shown to be important when analyzing risk factors. The conclusions of the knowledge gained and the recommendations for the practice deal with recommendations to change the flow policy, develop a

  17. The Impacts of Grade Retention: Benefits and Challenges Perceived by Retained Middle School Students

    ERIC Educational Resources Information Center

    Rand, Lauren E.

    2013-01-01

    No Child Left Behind legislation and high stakes testing have increased the pressure for public schools to ensure academic achievement for all students. Each year, a large number of students do not demonstrate adequate achievement and are retained to repeat the grade level. The large number of students retained is an indication that the system…

  18. Circle of Strength: Tribal Colleges Aim to Recruit and Retain Native Male Students

    ERIC Educational Resources Information Center

    Pember, Mary Annette

    2011-01-01

    As tribal colleges aim to retain Native male students, they're finding that talking, drumming, construction, and spirituality may keep men in school. Lac Courte Oreilles Ojibwe Community College (LCOOCC, Hayward, Wisconsin) is just one of the tribal colleges across the country looking for innovative ways to attract and retain more men.…

  19. 75 FR 11207 - Policy Statement on Obtaining and Retaining Beneficial Ownership Information for Anti-Money...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-10

    ... this provision. Special Due Diligence Programs for Certain Foreign Accounts, 72 FR 44768-44775 (August... COMMISSION Policy Statement on Obtaining and Retaining Beneficial Ownership Information for Anti-Money... retaining beneficial ownership information for anti-money laundering purposes. DATES: Effective Date:...

  20. RECRUITING, RETAINING, AND REPORTING EXPOSURE STUDY RESULTS TO PARTICIPANTS AND THE PUBLIC

    EPA Science Inventory

    EPA's National Exposure Research Laboratory (NERL) is developing techniques and capabilities to recruit and retain participants in exposure measurement studies and to effectively report study results to participants and the public. These techniques are being applied in three N...

  1. Determination of strength behaviour of slope supported by vegetated crib walls using centrifuge model testing

    NASA Astrophysics Data System (ADS)

    Sudan Acharya, Madhu

    2010-05-01

    The crib retaining structures made of wooden/bamboo logs with live plants inside are called vegetative crib walls which are now becoming popular due to their advantages over conventional civil engineering walls. Conventionally, wooden crib walls were dimensioned based on past experiences. At present, there are several guidelines and design standards for machine finished wooden crib walls, but only few guidelines for the design and construction of vegetative log crib walls are available which are generally not sufficient for an economic engineering design of such walls. Analytical methods are generally used to determine the strength of vegetated crib retaining walls. The crib construction is analysed statically by satisfying the condition of static equilibrium with acceptable level of safety. The crib wall system is checked for internal and external stability using conventional monolithic and silo theories. Due to limitations of available theories, the exact calculation of the strength of vegetated wooden/bamboo crib wall cannot be made in static calculation. Therefore, experimental measurements are generally done to verify the static analysis. In this work, a model crib construction (1:20) made of bamboo elements is tested in the centrifuge machine to determine the strength behaviour of the slope supported by vegetated crib retaining wall. A geotechnical centrifuge is used to conduct model tests to study geotechnical problems such as the strength, stiffness and bearing capacity of different structures, settlement of embankments, stability of slopes, earth retaining structures etc. Centrifuge model testing is particularly well suited to modelling geotechnical events because the increase in gravitational force creates stresses in the model that are equivalent to the much larger prototype and hence ensures that the mechanisms of ground movements observed in the tests are realistic. Centrifuge model testing provides data to improve our understanding of basic mechanisms

  2. Effects of the Upper Taum Sauk Reservoir Embankment Breach on the Surface-Water Quality and Sediments of the East Fork Black River and the Black River, Southeastern Missouri - 2006-07

    USGS Publications Warehouse

    Barr, Miya N.

    2009-01-01

    On December 14, 2005, a 680-foot wide section of the upper reservoir embankment of the Taum Sauk pump-storage hydroelectric powerplant located in Reynolds County, Missouri, suddenly failed. This catastrophic event sent approximately 1.5 billion gallons of water into the Johnson's Shut-Ins State Park and into the East Fork Black River, and deposited enormous quantities of rock, soil, and vegetation in the flooded areas. Water-quality data were collected within and below the impacted area to study and document the changes to the riverene system. Data collection included routine, event-based, and continuous surface-water quality monitoring as well as suspended- and streambed-sediment sampling. Surface water-quality samples were collected and analyzed for a suite of physical and chemical constituents including: turbidity; nutrients; major ions such as calcium, magnesium, and potassium; total suspended solids; total dissolved solids; trace metals such as aluminum, iron, and lead; and suspended-sediment concentrations. Suspended-sediment concentrations were used to calculate daily sediment discharge. A peculiar blue-green coloration on the water surface of the East Fork Black River and Black River was evident downstream from the lower reservoir during the first year of the study. It is possible that this phenomenon was the result of 'rock flour' occurring when the upper reservoir embankment was breached, scouring the mountainside and producing extremely fine sediment particles, or from the alum-based flocculent used to reduce turbidity in the lower reservoir. It also was determined that no long-term effects of the reservoir embankment breach are expected as the turbidity and concentrations of trace metals such as total recoverable aluminum, dissolved aluminum, dissolved iron, and suspended-sediment concentration graphically decreased over time. Larger concentrations of these constituents during the beginning of the study also could be a direct result of the alum

  3. Numerical Modelling of Embankment on Soft Clay

    NASA Astrophysics Data System (ADS)

    Nujid, M. M.; Taha, M. R.

    2016-07-01

    This paper aims to predict deformation of embankment on soft clay of Muar. The prediction performance focusing on displacement at critical fill height of 5.5 m. The study was based on reported result in 1992. With the aid of computer intelligence, the advanced constitutive soil models could be adopted to analyze the soft clay behavior. The COMSOL Multiphysics (v4.4) has been used to simulate the problem with coupled physics available in the software. The vertical displacements are in good agreement close to published result.

  4. Recruiting and Retaining Geology Majors at CSUSB: Successes and Barriers

    NASA Astrophysics Data System (ADS)

    Smith, A. L.; McGill, S. F.; Fryxell, J. E.; Leatham, W. B.; Melchiorre, E.; Brunkhorst, B.

    2003-12-01

    Our efforts to build a strong geology department at CSUSB have focused on two main areas (1) increasing the number of geology majors, and (2) involving our majors more directly in the department through their involvement in scientific research and outreach activities. To increase the number of majors we have undertaken a three pronged approach: (a) by actively working with middle and high school teachers to better prepare them to teach Earth Sciences in their schools, by providing them with the necessary tools to accomplish this, and by developing a new course on Earth Sciences with emphasis on the California Earth Science Standards to be taken by students in the multi-subject credential program; (b) by showing middle school, high school, and college students that geology is interesting and exciting by involving them in geological activities such as field trips, hands on geological exercises, and in directed research projects; and (c) by conducting a public relations campaign to inform both potential students and the general public about activities being undertaken by the department. The latter has been accomplished by the use of a glossy color brochure designed to illustrate what geology is, and what kinds of careers are possible; by flyers sent to approximately 120 local schools outlining opportunities for field trips and for teachers to bring their students to our campus for various activities; by developing an outreach web site; and by various newspaper articles on departmental activities. We are also looking into the use of TV spots on geological subjects to be aired on public access television. Since the start of our efforts two years ago we have seen a positive response by local teachers, and an increase in the number of applications to study geology at CSUSB, including a significant increase in the number of minority applicants. A major barrier to recruitment has been the misconceived idea in local schools that a course in Earth Sciences does not count

  5. Wall Shear Stress, Wall Pressure and Near Wall Velocity Field Relationships in a Whirling Annular Seal

    NASA Technical Reports Server (NTRS)

    Morrison, Gerald L.; Winslow, Robert B.; Thames, H. Davis, III

    1996-01-01

    The mean and phase averaged pressure and wall shear stress distributions were measured on the stator wall of a 50% eccentric annular seal which was whirling in a circular orbit at the same speed as the shaft rotation. The shear stresses were measured using flush mounted hot-film probes. Four different operating conditions were considered consisting of Reynolds numbers of 12,000 and 24,000 and Taylor numbers of 3,300 and 6,600. At each of the operating conditions the axial distribution (from Z/L = -0.2 to 1.2) of the mean pressure, shear stress magnitude, and shear stress direction on the stator wall were measured. Also measured were the phase averaged pressure and shear stress. These data were combined to calculate the force distributions along the seal length. Integration of the force distributions result in the net forces and moments generated by the pressure and shear stresses. The flow field inside the seal operating at a Reynolds number of 24,000 and a Taylor number of 6,600 has been measured using a 3-D laser Doppler anemometer system. Phase averaged wall pressure and wall shear stress are presented along with phase averaged mean velocity and turbulence kinetic energy distributions located 0.16c from the stator wall where c is the seal clearance. The relationships between the velocity, turbulence, wall pressure and wall shear stress are very complex and do not follow simple bulk flow predictions.

  6. 27. "TEST STAND; STRUCTURAL; SIDEWALL, NORTH WALL AND SOUTH WALL ...

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

    27. "TEST STAND; STRUCTURAL; SIDEWALL, NORTH WALL AND SOUTH WALL FRAMING ELEVATIONS." Specifications No. ENG-04353-55-72; Drawing No. 60-09-12; sheet 27 of 148; file no. 1320/78. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract no. 4338, Rev. B; date: 15 April 1957. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-A, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  7. MHD Electrode and wall constructions

    DOEpatents

    Way, Stewart; Lempert, Joseph

    1984-01-01

    Electrode and wall constructions for the walls of a channel transmitting the hot plasma in a magnetohydrodynamic generator. The electrodes and walls are made of a plurality of similar modules which are spaced from one another along the channel. The electrodes can be metallic or ceramic, and each module includes one or more electrodes which are exposed to the plasma and a metallic cooling bar which is spaced from the plasma and which has passages through which a cooling fluid flows to remove heat transmitted from the electrode to the cooling bar. Each electrode module is spaced from and electrically insulated from each adjacent module while interconnected by the cooling fluid which serially flows among selected modules. A wall module includes an electrically insulating ceramic body exposed to the plasma and affixed, preferably by mechanical clips or by brazing, to a metallic cooling bar spaced from the plasma and having cooling fluid passages. Each wall module is, similar to the electrode modules, electrically insulated from the adjacent modules and serially interconnected to other modules by the cooling fluid.

  8. 40 CFR 35.925-17 - Retained amounts for reconstruction and expansion.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.925-17 Retained amounts for reconstruction and expansion. That the allowable...

  9. 40 CFR 35.925-17 - Retained amounts for reconstruction and expansion.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.925-17 Retained amounts for reconstruction and expansion. That the allowable...

  10. 40 CFR 35.925-17 - Retained amounts for reconstruction and expansion.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.925-17 Retained amounts for reconstruction and expansion. That the allowable...

  11. 40 CFR 35.925-17 - Retained amounts for reconstruction and expansion.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.925-17 Retained amounts for reconstruction and expansion. That the allowable...

  12. 40 CFR 35.925-17 - Retained amounts for reconstruction and expansion.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.925-17 Retained amounts for reconstruction and expansion. That the allowable...

  13. Retaining Large and Adjustable Elastic Strains of Kilogram-Scale Nb Nanowires.

    PubMed

    Hao, Shijie; Cui, Lishan; Wang, Hua; Jiang, Daqiang; Liu, Yinong; Yan, Jiaqiang; Ren, Yang; Han, Xiaodong; Brown, Dennis E; Li, Ju

    2016-02-10

    Individual metallic nanowires can sustain ultralarge elastic strains of 4-7%. However, achieving and retaining elastic strains of such magnitude in kilogram-scale nanowires are challenging. Here, we find that under active load, ∼ 5.6% elastic strain can be achieved in Nb nanowires embedded in a metallic matrix deforming by detwinning. Moreover, large tensile (2.8%) and compressive (-2.4%) elastic strains can be retained in kilogram-scale Nb nanowires when the external load was fully removed, and adjustable in magnitude by processing control. It is then demonstrated that the retained tensile elastic strains of Nb nanowires can increase their superconducting transition temperature and critical magnetic field, in comparison with the unstrained original material. This study opens new avenues for retaining large and tunable elastic strains in great quantities of nanowires and elastic-strain-engineering at industrial scale. PMID:26745016

  14. Optofluidic realization and retaining of cell–cell contact using an abrupt tapered optical fibre

    PubMed Central

    Xin, Hongbao; Zhang, Yao; Lei, Hongxiang; Li, Yayi; Zhang, Huixian; Li, Baojun

    2013-01-01

    Studies reveal that there exists much interaction and communication between bacterial cells, with parts of these social behaviors depending on cell–cell contacts. The cell–cell contact has proved to be crucial for determining various biochemical processes. However, for cell culture with relatively low cell concentration, it is difficult to precisely control and retain the contact of a small group of cells. Particularly, the retaining of cell–cell contact is difficult when flows occur in the medium. Here, we report an optofluidic method for realization and retaining of Escherichia coli cell–cell contact in a microfluidic channel using an abrupt tapered optical fibre. The contact process is based on launching a 980-nm wavelength laser into the fibre, E. coli cells were trapped onto the fibre tip one after another, retaining cell–cell contact and forming a highly organized cell chain. The formed chains further show the ability as bio-optical waveguides. PMID:23771190

  15. Optofluidic realization and retaining of cell-cell contact using an abrupt tapered optical fibre

    NASA Astrophysics Data System (ADS)

    Xin, Hongbao; Zhang, Yao; Lei, Hongxiang; Li, Yayi; Zhang, Huixian; Li, Baojun

    2013-06-01

    Studies reveal that there exists much interaction and communication between bacterial cells, with parts of these social behaviors depending on cell-cell contacts. The cell-cell contact has proved to be crucial for determining various biochemical processes. However, for cell culture with relatively low cell concentration, it is difficult to precisely control and retain the contact of a small group of cells. Particularly, the retaining of cell-cell contact is difficult when flows occur in the medium. Here, we report an optofluidic method for realization and retaining of Escherichia coli cell-cell contact in a microfluidic channel using an abrupt tapered optical fibre. The contact process is based on launching a 980-nm wavelength laser into the fibre, E. coli cells were trapped onto the fibre tip one after another, retaining cell-cell contact and forming a highly organized cell chain. The formed chains further show the ability as bio-optical waveguides.

  16. 9 CFR 310.3 - Carcasses and parts in certain instances to be retained.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... certain instances to be retained. Each carcass, including all detached organs and other parts, in which..., detached organ, or other part shall be maintained until the final inspection has been completed....

  17. Assessment of Factors Affecting Adolescent Patients’ Compliance with Hawley and Vacuum Formed Retainers

    PubMed Central

    Mirzakouchaki, Behnam; Sharghi, Reza; Shirazi, Samaneh

    2016-01-01

    Introduction Success of orthodontic retention with removable retainers almost entirely depends on patients’ compliance. Aim This study was carried out to investigate the relationship between adolescent orthodontic patients’ compliance and various clinical and social factors. Materials and Methods The data were collected from 77 orthodontic patients aged 7-11 years old who had finished the full fixed appliance therapy. Hawley’s retainers were used in 34 patients and 43 patients used Vacuum Formed Retainers (VFRs). The subjects completed a questionnaire including several identifiers allowing the respondents to be classified into subgroups. They were also asked to indicate how long they wore their retainers during the day, by writing the number of hours in the report-card for the next three months. Comparison of the results was performed by one-way ANOVA and independent sample-t tests. Results No significant differences were found between males and females. Type of the retainer, patients’ grade of study, mothers’ occupation, clinicians’ and parents’ attitudes and filling the report cards had significant effect on mean wear hours per day. When compliance of the patients was assessed according to treatment location, Living place, parents’ educational degrees and ethnicity, no significant differences could be found. Conclusion The adolescent patients’ compliance was greater with VFRs than with Hawley’s retainers. Parental attitude and doctor-patient relationship had a great impact on adolescent patients’ compliance. PMID:27504404

  18. Autofrettage: Stress distribution under load and retained stresses after depressurization. A modified plane-strain case

    NASA Astrophysics Data System (ADS)

    Avitzur, Boaz

    1993-04-01

    There is a long-standing interest in developing a capability to predict the distribution of retained stresses in thick-walled pressure vessels after the removal of an internal pressure--post autofrettage. The key to such a prediction is in the capacity to compute the stress distribution in a vessel while under externally imposed stress sufficient enough to cause at least partial plastic deformation. A good approximation of the stress distribution was developed by Mises in his 1913 plane-stress solution. The fact that such vessels are not representative of the plane-stress condition not withstanding, Mises recognized that his solution was mathematically restricted to a limited range of vessels' wall ratios. More recently, Avitzur offered a solution similar to that of Mises, but for a plane-strain condition. Depending on the material's Poisson's factor, Avitzur's solution is also mathematically applicable for a limited range of vessels' wall ratios only. The wall ratio, beyond which Avitzur's solution in plane-strain is not applicable, is a few times larger than that which limits Mises' solution in plane-stress. This work introduces a modification to Avitzur's solution in plane-strain, which makes its applicability unlimited.

  19. Retaining and attracting large customers in a competitive market

    SciTech Connect

    Solger, S.

    1996-12-31

    This paper describes marketing and customer satisfaction in the electric power industry and the experiences of Wal-Mart stores. Customer service, reliability, working relationships, and customer knowledge are discussed.

  20. Colleges Design New Housing to Engage and Retain Students

    ERIC Educational Resources Information Center

    Peterkin, Caitlin

    2013-01-01

    With goals of fostering an intellectual atmosphere, building relationships, and increasing students' involvement on campus--and, ultimately, their rates of retention--universities around the country, including Elon, Michigan State, and Southern Methodist, are looking to residence life. House systems, residential neighborhoods, and living-learning…

  1. Hydrologic Analysis of Ungauged Catchments For The Supply of Water For Irrigation On Railway Embankment Batters

    NASA Astrophysics Data System (ADS)

    Gyasi-Agyei, Y.; Nissen, D.

    Water has been identified as a key component to the success of grass establishment on railway embankment batters (side slope) within Central Queensland, Australia, to control erosion. However, the region under study being semi-arid experiences less than 600 mm average annual rainfall occurring on about 60 days of the year. Culverts and bridges are integral part of railway embankments. They are used to cross water courses, be it an ephemeral creek or just a surface runoff path. Surface runoff through an ungauged railway embankment culvert is diverted to a temporary excavated pond located at the downstream side of the hydraulic structure. The temporary excavated pond water is used to feed an automated drip irrigation system, with solar as a source of energy to drive a pump. Railway embankment batter erosion remediation is timed in the wet season when irrigation is used to supplement natural rainfall. Hydrologic analysis of ungauged catchments for sizing the temporary excavated pond is presented. It is based on scenarios of runoff coefficient and curve number, and mass curve (Rippl diagram). Three years of continuous rainfall data (1997/1998 -1999/2000) were used to design a pond. The performance of the designed pond was evaluated in a field experiment during the next wet season (2000/2001). It supplied adequate water for irrigation as predicted by the hydrologic analysis during the grass establishment. This helped to achieve 100% grass cover on the railway embankment batter within 12 weeks. The proposed irrigation system has been demonstrated t o be feasible and cost effective.

  2. Lactating Rats Retain Nursing Behavior and Maternal Care in Space

    NASA Technical Reports Server (NTRS)

    Daly, Megan E.; Ronca, April E.; Dalton, Bonnie (Technical Monitor)

    2001-01-01

    In 1997, suckling mammals were flown in space for the first time as part of the NIH.R3 experiment sponsored jointly by NIH (National Institutes of Health) and NASA. Six rat dams and litters (Rattus norvegicus) were launched on an eight-day Space Shuttle mission at each of three postnatal ages (P5, P8, and P15). Dams and litters (N = 10 pups/litter) were housed within modified Animal Enclosure Modules (AEMs). Comparisons were made to ground controls. Dams and litters were videotaped daily in flight. The P8 and P15 flight litters showed excellent survival (99%) and weight gain relative to AEM ground controls, whereas P5 litters showed reduced survival (0% and 60%, respectively) and weight gain (less than 40% AEM). To examine the possibility that failures of maternal care contributed to P5 results, we analyzed the dams' in-flight nursing, licking and retrieving from four video segments ranging from twelve to fifteen minutes in length with control data derived from multiple ground segments. Video analyses revealed clear evidence of maternal care in flight. For P5 dams, frequency and duration of nursing and licking bouts fell within or above one standard deviation of control values. Retrieving was noted in the P5 and P8 groups only. The observed results suggest that factors other than maternal care contributed to the low survival rates and body weight gains of the P5 flight offspring.

  3. Hydraulics of embankment-dam breaching

    NASA Astrophysics Data System (ADS)

    Walder, J. S.; Iverson, R. M.; Logan, M.; Godt, J. W.; Solovitz, S.

    2012-12-01

    the hydrograph in another way: the broader the initial dam crest, the longer the time before critical flow control is established. Flood duration is thus increased but peak discharge is decreased. Visual inspection and overhead videography reveal little turbidity in water pouring over the weir, implying that sediment there moves dominantly as bedload. Furthermore, underwater videography gives the overall impression that along the upstream dam face, erosion occurs without redeposition. Thus it would be a mistake to use empiricisms for equilibrium bedload transport to model erosion of the embankment. In mathematical terms, erosion rate cannot be backed out by calculating the divergence of transport rate; rather, transport rate should be regarded as the spatial integral of erosion rate. We use photogrammetry and motion of the colored markers to determine the erosion rate of the weir, and then infer shear stress at the weir by applying the van Rijn sediment-pickup function. Shear stress determined in this fashion is much less than what one calculates from the gradient of the energy head (an approach appropriate to steady flow). Shear stress inferred from the pickup-function calculation can serve as a constraint on computational fluid-dynamics models. Another constraint on such models, revealed by the underwater videography, is the upstream limit of sand movement, where bed shear stress equals the critical value for sand entrainment.

  4. Negligent Hiring and Retaining of Sexually Abusive Teachers.

    ERIC Educational Resources Information Center

    Regotti, Terri L.

    1992-01-01

    Explores negligent hiring, supervision, and retention of teachers who sexually abuse students. Examines the issue of defamation and suggests school policy that will work toward eradication of sexual abuse of students by teachers. (33 references) (MLF)

  5. Recruiting and Retaining Adult Students: An Organizational Theory Perspective.

    ERIC Educational Resources Information Center

    Cookson, Peter S.

    1989-01-01

    Describes the recruitment and retention of adult students in light of two varieties of organizational theory. Compliance theory was formulated to classify relationships between organizational representatives and "lower participants" in large organizations. Open systems theory emphasizes the nature of the interaction between an organization and its…

  6. Stemming the Tide: Retaining and Supporting Science Teachers

    ERIC Educational Resources Information Center

    Pirkle, Sheila F.

    2011-01-01

    Chronically high rates of new and experienced science teacher attrition and the findings of new large-scale mentoring programs indicate that administrators should adopt new approaches. A science teacher's role encompasses demanding responsibilities, such as observing laboratory safety and OSHA mandates, as well as management of a business-like,…

  7. Recruiting and Retaining Speech-Language Pathologists in Rural Areas.

    ERIC Educational Resources Information Center

    Prichard, Cheryl L.

    This study surveyed special education directors and speech language pathologists (SLPs) to identify recruitment and retention strategies currently in place in West Virginia and related problems. A 13-item questionnaire was mailed to all 55 Special Education Directors (SED) in West Virginia. A second survey instrument, consisting of 36 items, was…

  8. Recruiting and Retaining Information Technology Staff in Higher Education.

    ERIC Educational Resources Information Center

    Educause Quarterly, 2000

    2000-01-01

    Recruitment and retention of higher education information technology (IT) professionals is a campuswide problem. This paper presents information from meetings of a working group of IT professionals, human resources (HR) professionals, and business officers that examined recruitment, retention, retraining, and restructuring, highlighting:…

  9. Recruiting and Retaining New Generations of Community College Faculty

    ERIC Educational Resources Information Center

    Mouchayleh, Theresa Stewart

    2009-01-01

    Much generational research has been conducted in the last decade, prompted most likely by the drastic social and technological changes of the late 20th century, the increase in enrollments in higher education, the increase in families with two working parents, and the meteoric rise in the widespread use and acceptance of emerging technologies.…

  10. Recruiting and Retaining High-Quality Teachers in Rural Areas

    ERIC Educational Resources Information Center

    Monk, David H.

    2007-01-01

    In examining recruitment and retention of teachers in rural areas, David Monk begins by noting the numerous possible characteristics of rural communities--small size, sparse settlement, distance from population concentrations, and an economic reliance on agricultural industries that are increasingly using seasonal and immigrant workers to minimize…

  11. Retaining Public and Political Trust: Teacher Education in Scotland

    ERIC Educational Resources Information Center

    Gray, Donald; Weir, Douglas

    2014-01-01

    This paper traces the key periods, players and events which have contributed to the shaping of the current landscape of teacher education in Scotland. Starting with the Wheatley Report and the formation of the General Teaching Council (Scotland) in the 1960s through to the most recent Donaldson Review of Teacher Education, we examine ebb and flow…

  12. On-Line Course Development: Engaging and Retaining Students

    ERIC Educational Resources Information Center

    Bruster, Benita G.

    2015-01-01

    As the number of on-line classes and the demand for on-line education continues to sky-rocket, it is critical that course developers and university faculty have the skills to effectively design curricula, to develop engaging learning opportunities, and to create responsive courses that meet individual student needs. This paper details three…

  13. Recruiting and retaining plasmapheresis donors: A critical belief analysis.

    PubMed

    Bagot, Kathleen L; Masser, Barbara M; White, Katherine M; Starfelt, Louise C

    2015-06-01

    This paper identifies critical beliefs underpinning intentions to commence and continue plasmapheresis donation. Whole blood (n = 624) and first-time plasmapheresis (n = 460) donors completed a cross-sectional survey assessing the belief-base of the theory of planned behaviour and rated their plasmapheresis donation intentions. While the idea of red blood cells being returned was a key deterrent for all donors, critical beliefs underlying commencement and continuation in the plasmapheresis donor panel differed and varied as a function of blood donation history. Findings will assist the development of targeted persuasion messages to optimise recruitment and retention of plasmapheresis donors in a non-remunerated context. PMID:25824702

  14. Using nonqualified benefits to recruit and retain physicians.

    PubMed

    Nolan, M

    2000-10-01

    Financial managers of healthcare organizations often are charged with developing incentives that encourage physicians to join or stay with the organization. Standard incentives such as higher salaries and qualified retirement plans may not attract physicians, because much of a physician's salary increase may be lost to taxes, and regulations limit amounts that physicians can contribute to and receive from qualified retirement plans. Incentives that may be valued more highly by physicians include Section 162 bonus plans, which can allow the healthcare organization to compensate for the fact that bonuses are taxable to physicians; split-dollar welfare benefit plans, which allow the healthcare organization and the physician to split the premium payments, cash values, and death proceeds of a life insurance policy; and discounted stock option plans, which can increase the physician's compensation significantly if the shares appreciate in value by the time they are exercised. PMID:11183546

  15. Retained IOL fragment and corneal decompensation after pseudophakic IOL exchange.

    PubMed

    Hoffman, Richard S; Fine, I Howard; Packer, Mark

    2004-06-01

    A 72-year-old man had exchange of a foldable silicone multifocal intraocular lens (IOL) by transection, removal, and monofocal IOL replacement. One month after the exchange, irreversible corneal edema developed and penetrating keratoplasty was performed. At the time of the corneal transplant, a small silicone fragment was discovered in and removed from the anterior chamber. Histologic evaluation of the patient's cornea demonstrated an absence of corneal endothelium, suggesting the fragment was the etiology of the corneal decompensation. PMID:15177618

  16. Recruiting and Retaining Adult Students: A Practice Perspective.

    ERIC Educational Resources Information Center

    Cookson, Peter S.

    1989-01-01

    In continuing education, recruitment is the step whereby adults are inducted into a program of systematic learning; retention relates to the capacity of the program to transform the initial commitment into continuing participation. Adult students are more likely to initiate and to continue participation when recruitment and retention activities…

  17. Water-retaining barrier and method of construction

    DOEpatents

    Adams, Melvin R.; Field, Jim G.

    1996-01-01

    An agricultural barrier providing a medium for supporting plant life in an arid or semi-arid land region having a ground surface, the barrier being disposed on native soil of the region, the barrier including: a first layer composed of pieces of basalt, the first layer being porous and being in contact with the native soil; a porous second layer of at least one material selected from at least one of sand and gravel, the second layer being less porous than, and overlying, the first layer; and a porous third layer containing soil which favors plant growth, the third layer being less porous than, and overlying, the second layer and having an exposed upper surface, wherein the porosities of the second and third layers differ from one another by an amount which impedes transport of soil from the first layer into the second layer. Soil for the third layer may be provided by washing salinated or contaminated soil with water and using the washed soil for the third layer.

  18. Retaining Latino Students: Culturally Responsive Instruction in Colleges and Universities

    ERIC Educational Resources Information Center

    Pappamihiel, N. Eleni; Moreno, Marcio

    2011-01-01

    In this article the authors define and describe culturally responsive teaching (CRT) in college and university courses. Whereas, the Latino population in our K-12 schools has grown rapidly, we have not seen such growth in the population of Latino students in our postsecondary schools. It is the authors' position that CRT can be a tool in helping…

  19. Recruiting, retaining, and advancing careers for employees from underrepresented groups.

    PubMed

    Smith, Toni C; Ingersoll, Gail L; Robinson, Regina; Hercules, Hazeldene; Carey, Janet

    2008-04-01

    In response to the need to increase the number of persons from underrepresented groups working in acute care settings, 2 hospitals in upstate New York implemented a multidimensional workforce development project targeting existing and new employees meeting federally defined poverty levels. The authors describe the project and its outcomes, which surpassed original expectations. PMID:18403992

  20. Factors in Recruiting and Retaining Health Professionals for Rural Practice

    ERIC Educational Resources Information Center

    Daniels, Zina M.; VanLeit, Betsy J.; Skipper, Betty J.; Sanders, Margaret L.; Rhyne, Robert L.

    2007-01-01

    Context: Rural communities, often with complex health care issues, have difficulty creating and sustaining an adequate health professional workforce. Purpose: To identify factors associated with rural recruitment and retention of graduates from a variety of health professional programs in the southwestern United States. Methods: A survey…

  1. Recruiting and Retaining Black Male Teachers in Gifted Education

    ERIC Educational Resources Information Center

    Bryan, Nathaniel; Ford, Donna Y.

    2014-01-01

    Every school district shares the pervasive issue of having males under-represented in the teaching profession. Likewise, most have a paucity of teachers who are African American. Combining both gender and race, only 1% of teachers are Black males. In the article, we rely on scholarship regarding the lack of diversity among teachers and among males…

  2. Evaluating Programs for Recruiting and Retaining Community Faculty.

    ERIC Educational Resources Information Center

    Single, Peg Boyle; Jaffe, Arnold; Schwartz, Robert

    1999-01-01

    Surveyed community physicians affiliated with a teaching hospital to assess factors influencing their decisions to serve as preceptors and the relative value of incentives. Found that student influence on patient care was a driving factor, that preceptors preferred nonmonetary compensation, such as continuing medical education credit, and that…

  3. Recruiting, Training, and Retaining High-Performance Development Teams

    ERIC Educational Resources Information Center

    Elder, Stephen D.

    2010-01-01

    This chapter offers thoughts on some key elements of a high-performing development environment. The author describes how good development officers love to be part of something big, something that transforms a place and its people, and that thinking big is a powerful concept for development officers. He reminds development officers to be clear…

  4. Insoluble and soluble roasted walnut proteins retain antibody reactivity.

    PubMed

    Downs, Melanie L; Simpson, Angela; Custovic, Adnan; Semic-Jusufagic, Aida; Bartra, Joan; Fernandez-Rivas, Montserrat; Taylor, Steve L; Baumert, Joseph L; Mills, E N Clare

    2016-03-01

    Thermal processing techniques commonly used during food production have the potential to impact food allergens by inducing physical and/or chemical changes to the proteins. English walnuts (Juglans regia) are among the most commonly allergenic tree nuts, but little information is available regarding how walnut allergens respond to thermal processing. This study evaluated the effects of dry roasting (132 or 180°C for 5, 10, or 20min) on the solubility and immunoreactivity of walnut proteins. A dramatic decrease in walnut protein solubility was observed following dry roasting at 180°C for 20min. However, both the soluble and insoluble protein fractions from roasted walnuts maintained substantial amounts of IgG immunoreactivity (using anti-raw and anti-roasted walnut antisera), with similar patterns of reactivity observed for human IgE from walnut-allergic individuals. Thus, walnut proteins are relatively stable under certain thermal processing conditions, and IgE reactivity remains present even when insoluble aggregates are formed. PMID:26471647

  5. Water-retaining barrier and method of construction

    DOEpatents

    Adams, M.R.; Field, J.G.

    1996-02-20

    An agricultural barrier is disclosed which provides a medium for supporting plant life in an arid or semi-arid land region having a ground surface. The barrier is disposed on native soil of the region. The barrier includes a first porous layer composed of pieces of basalt, and is in contact with the native soil. There is a less porous second layer of at least one material selected from at least one of sand and gravel. The second layer overlies the first layer. A third layer, less porous than the second layer, contains soil which favors plant growth. The third layer overlies the second layer and has an exposed upper surface. The porosities of the second and third layers differ from one another by an amount which impedes transport of soil from the first layer into the second layer. Soil for the third layer may be provided by washing salinated or contaminated soil with water and using the washed soil for the third layer. 2 figs.

  6. Retaining Students in Science, Technology, Engineering, and Mathematics (STEM) Majors

    ERIC Educational Resources Information Center

    Watkins, Jessica; Mazur, Eric

    2013-01-01

    In this paper we present results relating undergraduate student retention in science, technology, engineering, and mathematics (STEM) majors to the use of Peer Instruction (PI) in an introductory physics course at a highly selective research institution. We compare the percentages of students who switch out of a STEM major after taking a physics…

  7. Recruiting, Preparing and Retaining Teachers for Urban Schools

    ERIC Educational Resources Information Center

    Howey, Kenneth R., Ed.; Post, Linda M., Ed.; Zimpher, Nancy L., Ed.

    2006-01-01

    How can the "revolving door" at the nation's high-poverty schools be slowed down? How can diversity be taught in teacher preparation that relates to teaching and learning? How can teachers learn to use the diverse urban classroom as a rich asset? By focusing on reconceptualizing general education studies, addressing key urban understanding and…

  8. Recruiting, Reviewing, and Retaining High-Risk Older Adult Populations

    ERIC Educational Resources Information Center

    Rosen, Daniel

    2014-01-01

    The Institute on Aging and Social Work (IASW) provides social work faculty with advanced training in aging research with the goal of mentoring individuals to develop National Institutes of Health (NIH) research proposals. The program offers an excellent opportunity for top-level training with nationally recognized experts in research methodology…

  9. Protean Organizations: Reshaping Work and Careers to Retain Female Talent

    ERIC Educational Resources Information Center

    Cabrera, Elizabeth F.

    2009-01-01

    Purpose: This paper aims to understand women's careers better in order to help organizations make changes to increase female retention. Two specific questions are addressed: Are women adopting a protean career orientation by becoming career self-agents?; and Are women's career decisions guided by the kaleidoscope values of challenge, balance, and…

  10. Device Acquires and Retains Rock or Ice Samples

    NASA Technical Reports Server (NTRS)

    Giersch, Louis R.; Backes, Paul G.

    2009-01-01

    The Rock Baller is a sample acquisition tool that improves sample retention. The basic elements of the Rock Baller are the tool rotation axis, the hub, the two jaws, and the cutting blades, which are located on each of the jaws. The entire device rotates about the tool rotation axis, which is aligned parallel to the nominal normal direction of the parent rock surface. Both jaws also rotate about the jaw axis, which is perpendicular to the tool rotation axis, at a rate much slower than the rotation about the tool rotation axis. This movement gradually closes the jaws into a nearly continuous hemispherical shell that encloses the sample as it is cut from the parent rock. When required the jaws are opened to release the sample. The hemispherical cutting method eliminates the sample retention problems associated with existing sample acquisition methods that employ conventional cylindrical cutting. The resulting samples are hemispherical, or nearly hemispherical, and as a result the aspect ratio (sample depth relative to sample radius) is essentially fixed. This fixed sample aspect ratio may be considered a drawback of the Rock Baller method, as samples with a higher aspect ratio (more depth, less width) may be considered more scientifically valuable because such samples would allow for a broader inspection of the geological record. This aspect ratio issue can be ameliorated if the Rock Baller is paired with a device similar to the Rock Abrasion Tool (RAT) used on the Mars Exploration Rovers. The RAT could be used to first grind into the surface of the parent rock, after which the Rock Baller would extract a sample from a depth inside the rock that would not have been possible without first using the RAT. Other potential applications for this technology include medical applications such as the removal of tissue samples or tumors from the body, particularly during endoscopic, laparoscopic, or thoracoscopic surgeries.

  11. Tailoring Protocols to Successfully Recruit and Retain Elders in a Longitudinal Study of Sleep and Cognition

    PubMed Central

    Carlson, John R.; Neelon, Virginia J.; Hartman, Marilyn

    2012-01-01

    Many studies attest to the challenges of recruiting and retaining older adults in longitudinal studies. This article presents the methods used by the Physiological Research to Improve Sleep and Memory Project to recruit and retain 115 adults (70+ years) in a 2-year study that involved yearly administrations of two neurocognitive test batteries and two nights of polysomnography. The paper describes strategies which are built on knowledge obtained from participant informants and the use of tailored, individualize protocols. Together, these strategies enabled participants to become vested in the research process and to fully participate in all aspects of the study. PMID:20077997

  12. 17 CFR 240.17g-2 - Records to be made and retained by nationally recognized statistical rating organizations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... retained by nationally recognized statistical rating organizations. 240.17g-2 Section 240.17g-2 Commodity... Recognized Statistical Rating Organizations § 240.17g-2 Records to be made and retained by nationally recognized statistical rating organizations. (a) Records required to be made and retained. A...

  13. 17 CFR 240.17g-2 - Records to be made and retained by nationally recognized statistical rating organizations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... retained by nationally recognized statistical rating organizations. 240.17g-2 Section 240.17g-2 Commodity... Recognized Statistical Rating Organizations § 240.17g-2 Records to be made and retained by nationally recognized statistical rating organizations. (a) Records required to be made and retained. A...

  14. 17 CFR 240.17g-2 - Records to be made and retained by nationally recognized statistical rating organizations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... retained by nationally recognized statistical rating organizations. 240.17g-2 Section 240.17g-2 Commodity... Recognized Statistical Rating Organizations § 240.17g-2 Records to be made and retained by nationally recognized statistical rating organizations. (a) Records required to be made and retained. A...

  15. Cryogenic-Compatible Winchester Connector Mount and Retaining System for Composite Tubes

    NASA Technical Reports Server (NTRS)

    Pontius, James; McGuffey, Douglas

    2011-01-01

    A connector retainer and mounting system has been designed to replace screw-mounting of Winchester connectors. Countersunk screws are normally used to secure connectors to structures, and to keep them from coming apart. These screws are normally put into threaded or through-holes in metallic structures. This unique retainer is designed such that integral posts keep the connector halves retained, and a groove permits a cable tie to be fastened around the retainer and composite tube, thus securing the connector to the structure. The system is compatible for use on cryogenic (and conventional) bonded composite tube assemblies. Screws and tapped/through-holes needed to retain and mount Winchester connectors cannot be used on blind-access composite tubes. This system allows for rapid installation, removal, low-molecular-outgassing materials, and particulate-free installation and removal. Installation and/or changes late in the integration, and test flow with limited access in a cleanroom environment are possible. No sanding or bonding is needed.

  16. Strategies to Recruit and Retain Students in Physical Science and Mathematics on a Diverse College Campus

    ERIC Educational Resources Information Center

    Chang, Jen-Mei; Kwon, Chuhee; Stevens, Lora; Buonora, Paul

    2016-01-01

    This article presents implementation details and findings of a National Science Foundation Scholarship in Science, Technology, Engineering, and Mathematics Program (S-STEM) consisting of many high-impact practices to recruit and retain students in the physical sciences and mathematics programs, particularly first-generation and underrepresented…

  17. Math and Science Teachers: Recruiting and Retaining California's Workforce. Policy Brief

    ERIC Educational Resources Information Center

    EdSource, 2008

    2008-01-01

    Middle and high school math and science teachers provide the foundation for education in the growing science, technology, engineering, and mathematics fields. They are crucial to California's efforts to remain competitive in a global economy. This policy brief looks at the shortage and challenges involved in recruiting and retaining fully prepared…

  18. Retained Austenite in SAE 52100 Steel Post Magnetic Processing and Heat Treatment

    SciTech Connect

    Pappas, Nathaniel R; Watkins, Thomas R; Cavin, Odis Burl; Jaramillo, Roger A; Ludtka, Gerard Michael

    2007-01-01

    Steel is an iron-carbon alloy that contains up to 2% carbon by weight. Understanding which phases of iron and carbon form as a function of temperature and percent carbon is important in order to process/manufacture steel with desired properties. Austenite is the face center cubic (fcc) phase of iron that exists between 912 and 1394 C. When hot steel is rapidly quenched in a medium (typically oil or water), austenite transforms into martensite. The goal of the study is to determine the effect of applying a magnetic field on the amount of retained austenite present at room temperature after quenching. Samples of SAE 52100 steel were heat treated then subjected to a magnetic field of varying strength and time, while samples of SAE 1045 steel were heat treated then subjected to a magnetic field of varying strength for a fixed time while being tempered. X-ray diffraction was used to collect quantitative data corresponding to the amount of each phase present post processing. The percentage of retained austenite was then calculated using the American Society of Testing and Materials standard for determining the amount of retained austenite for randomly oriented samples and was plotted as a function of magnetic field intensity, magnetic field apply time, and magnetic field wait time after quenching to determine what relationships exist with the amount of retained austenite present. In the SAE 52100 steel samples, stronger field strengths resulted in lower percentages of retained austenite for fixed apply times. The results were inconclusive when applying a fixed magnetic field strength for varying amounts of time. When applying a magnetic field after waiting a specific amount of time after quenching, the analyses indicate that shorter wait times result in less retained austenite. The SAE 1045 results were inconclusive. The samples showed no retained austenite regardless of magnetic field strength, indicating that tempering removed the retained austenite. It is apparent

  19. Staffing an Empty Schoolhouse: Attracting and Retaining Teachers in Rural, Remote and Isolated Communities

    ERIC Educational Resources Information Center

    Roberts, Phil

    2004-01-01

    Attracting and retaining staff in rural and remote schools has been a perennial problem n Australia virtually since federation in 1901. In this report the author uses a mixed method approach of an on-line survey, unstructured interviews and policy analysis to develop a comprehensive overview of approaches to overcome these staffing problems…

  20. 75 FR 32857 - Academic Competitiveness Grant (ACG) and National Science and Mathematics Access To Retain Talent...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-10

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF EDUCATION 34 CFR Part 691 Academic Competitiveness Grant (ACG) and National Science and Mathematics Access To Retain Talent Grant (National Smart Grant) Programs CFR Correction In Title 34 of the Code of...

  1. Influence of retained austenite on short fatigue crack growth and wear resistance of case carburized steel

    SciTech Connect

    Silva, V.F. da; Canale, L.F.; Spinelli, D.P.; Bose-Filho, W.W.; Crnkovic, O.R.

    1999-10-01

    The influence of the amount of retained austenite on short fatigue crack growth and wear resistance in carburized SAE 8620 steel was studied in this article. Different amounts of retained austenite in the microstructure of the carburized case were obtained through different heat treatment routes applied after the carburizing process. The wear tests were carried out using pin on disk equipment. After every 200 turns the weight loss was registered. Four point bend fatigue tests were carried out at room temperature, using three different levels of stress and R = 0.1. Crack length versus number of cycles and crack growth rate versus mean crack length curves were analyzed. In both tests the results showed that the test pieces with higher levels of retained austenite in the carburized case exhibited longer fatigue life and better wear resistance.

  2. Recruiting and Retaining Mobile Young Injection Drug Users in a Longitudinal Study

    PubMed Central

    Lankenau, Stephen E.; Sanders, Bill; Hathazi, Dodi; Jackson Bloom, Jennifer

    2011-01-01

    Longitudinal studies that research homeless persons or transient drug users face particular challenges in retaining subjects. Between 2005 and 2006, 101 mobile young injection drug users were recruited in Los Angeles into a 2-year longitudinal study. Several features of ethnographic methodology, including fieldwork and qualitative interviews, and modifications to the original design, such as toll-free calls routed directly to ethnographer cell phones and wiring incentive payments, resulted in retention of 78% of subjects for the first follow-up interview. Longitudinal studies that are flexible and based upon qualitative methodologies are more likely to retain mobile subjects while also uncovering emergent research findings. PMID:20222779

  3. Evaluation of the cytotoxicity of fiber reinforced composite bonded retainers and flexible spiral wires retainers in simulated high and low cariogenic environments

    PubMed Central

    Jahanbin, Arezoo; Shahabi, Mostafa; Ahrari, Farzaneh; Bozorgnia, Yasaman; Shajiei, Arezoo; Shafaee, Hooman; Afshari, Jalil Tavakkol

    2015-01-01

    Objectives: The aim of this study was to evaluate the cytotoxic effects of fiber reinforced composite bonded retainers in comparison with flexible spiral wires (FSWs) under high and low cariogenic-simulated environments using human oral fibroblasts. Materials and Methods: Four types of bonded retainers were evaluated: (1) reinforced with glass fibers: Interlig (Angelus), (2) reinforced with polyethylene fibers: Connect (Kerr), (3) reinforced with quartz fibers: Quartz Splint UD (RTD), and (4) FSW. Twenty specimens of each sample group were prepared with the same surface area and halved. Next, half of them were placed in a high cariogenic environment 60 min in 10% lactic acid 3 times a day and remained in Fusayama Meyer artificial saliva for the rest of the day) and the other half were placed in a low cariogenic environment 20 min in 10% lactic acid 3 times a day and remained in Fusayama Meyer artificial saliva for the rest of the day) for 1, 7 and 30 days. Cell viability was assessed by MTT assay. Data were analyzed using SPSS software (α =0.05). Results: During the 1st month, cytotoxicity reduced gradually. In the low cariogenic-simulated environment, the cytotoxicity of all of the groups were reported to be mild at day 30 and the difference between them was significant (P = 0.016). In the same period in the high cariogenic-simulated environment, the cytotoxicity of Connect and Quartz Splint was mild, and they had lower cytotoxicity than the other groups. Meanwhile, Interlig had moderate (52%) and FSW had severe cytotoxicity (22%) and the difference between the groups was also significant (P = 0.000). Conclusions: FSW retainers are not recommended in those at high-risk for dental caries. However, in those at low-risk, there is no difference from the standpoint of cytotoxicity. PMID:25657987

  4. Combined Endoscopic and Percutaneous Retrieval of a Retained 4-Wire Ureteral Stone Basket

    PubMed Central

    Kaplan, Adam G.; Preminger, Glenn M.

    2015-01-01

    Abstract Complex endourologic procedures may require the use of a combined ureteroscopic and percutaneous approach. Endoscopic removal of a retained 4-wire ureteral stone basket is particularly complex, as broken tines can potentially injure the ureter if the basket is removed in a retrograde manner. The patient in this case presented with a ureteral stone basket embedded within the urothelium of the upper pole of the kidney. Holmium laser incision of the overlying urothelium allowed retrieval of the basket, although the tines were broken. Endoscopically guided percutaneous access to the kidney was obtained to allow for direct passage of the retained basket out of a nephrostomy sheath, thereby protecting the kidney.

  5. 29 CFR 1926.854 - Removal of walls, masonry sections, and chimneys.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... any scaffold or wall. (h) Walls, which serve as retaining walls to support earth or adjoining structures, shall not be demolished until such earth has been properly braced or adjoining structures...

  6. 29 CFR 1926.854 - Removal of walls, masonry sections, and chimneys.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... any scaffold or wall. (h) Walls, which serve as retaining walls to support earth or adjoining structures, shall not be demolished until such earth has been properly braced or adjoining structures...

  7. 29 CFR 1926.854 - Removal of walls, masonry sections, and chimneys.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... any scaffold or wall. (h) Walls, which serve as retaining walls to support earth or adjoining structures, shall not be demolished until such earth has been properly braced or adjoining structures...

  8. 29 CFR 1926.854 - Removal of walls, masonry sections, and chimneys.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... any scaffold or wall. (h) Walls, which serve as retaining walls to support earth or adjoining structures, shall not be demolished until such earth has been properly braced or adjoining structures...

  9. Incentives for Attracting and Retaining K-12 Teachers: Lessons for Early Education. Policy Brief.

    ERIC Educational Resources Information Center

    Laurence, Wendy; Hass, Bob; Burr, Elizabeth; Fuller, Bruce; Gardner, Mary; Hayward, Gerald; Kuboyama, Emlei

    This policy brief examines programs from California and elsewhere in the United States for attracting and retaining quality preschool and child-care staff and places these programs within the broader context of K-12 reforms. While this brief is specifically aimed at early-childhood-education planners and policymakers, it contains information for…

  10. 31 CFR 1021.410 - Additional records to be made and retained by casinos.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Additional records to be made and retained by casinos. 1021.410 Section 1021.410 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FINANCIAL CRIMES ENFORCEMENT NETWORK, DEPARTMENT OF THE TREASURY RULES FOR CASINOS AND CARD CLUBS Records Required To...

  11. An alternative means of retaining ocular structure and improving immunoreactivity for light microscopy studies

    PubMed Central

    Sun, Ning; Shibata, Brad; Hess, John F.

    2015-01-01

    Purpose Several properties of ocular tissue make fixation for light microscopy problematic. Because the eye is spherical, immersion fixation necessarily results in a temporal gradient of fixation, with surfaces fixing more rapidly and thoroughly than interior structures. The problem is compounded by the fact that the layers of the eye wall are compositionally quite different, resulting in different degrees of fixation-induced shrinkage and distortion. Collectively, these result in non-uniform preservation, as well as buckling and/or retinal detachment. This gradient problem is most acute for the lens, where the density of proteins can delay fixation of the central lens for days, and where the fixation gradient parallels the age gradient of lens cells, which complicates data interpretation. Our goal was to identify a simple method for minimizing some of the problems arising from immersion fixation, which avoided covalent modification of antigens, retained high quality structure, and maintained tissue in a state that is amenable to common cytochemical techniques. Methods A simple and inexpensive derivative of the freeze-substitution approach was developed and compared to fixation by immersion in formalin. Preservation of structure, immunoreactivity, GFP and tdTomato fluorescence, lectin reactivity, outer segment auto fluorescence, Click-iT chemistry, compatibility with in situ hybdrdization, and the ability to rehydrate eyes after fixation by freeze substitution for subsequent cryo sectioning were assessed. Results An inexpensive and simple variant of the freeze substitution approach provides excellent structural preservation for light microscopy, and essentially eliminates ocular buckling, retinal detachment, and outer segment auto-fluorescence, without covalent modification of tissue antigens. The approach shows a notable improvement in preservation of immunoreactivity. TdTomato intrinsic fluorescence is also preserved, as is compatibility with in situ

  12. Investing in Teachers: Retain and Recruit Teachers through Tax-Deferred Savings Programs.

    ERIC Educational Resources Information Center

    Healy, Barbara

    2002-01-01

    Describes how the combination of tax-deferred savings and tax-deferred retirement programs provided for in the Economic, Growth and Tax Relief and Reconciliation Act of 2001 can be used by school districts to attract and retain quality teachers. (PKP)

  13. Masticatory efficiency and oral health-related quality of life with implant-retained mandibular overdentures

    PubMed Central

    Sun, Xu; Zhai, Jun-Jiang; Liao, Jian; Teng, Min-Hua; Tian, Ai; Liang, Xing

    2014-01-01

    Objectives: To evaluate masticatory efficiency (ME) and oral health-related quality of life (OHRQoL) in patients rehabilitated with implant-retained mandibular overdentures. Methods: In this randomized controlled clinical trial, 50 edentulous patients visiting the Implant Center and Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu, China between June 2010 and June 2012 were selected and received 2 implant-retained mandibular overdenture treatments. All patients were rehabilitated with maxillary complete dentures. The ME and OHRQoL were determined both one month before the mandibular complete denture was anchored to the osseointegrated implants, and 6 months after anchoring. Paired t-tests were used to compare means of ME, and oral health impact profile-49 (OHIP-49) domains scores between pre- and post-implant. Linear regression models were utilized to seek correlations between ME and OHIP domains scores. Results: The ME increased from pre- to post-implant retained mandibular overdentures significantly (p<0.001). The total OHIP score and 4 subscales scores were changed significantly from pre- to post-implant; namely, functional limitation, psychological discomfort, physical disability, and physical pain. The total OHIP score, functional limitation, physical disability, and physical pain subscale scores were related to ME. Conclusion: Implant-retained mandibular over dentures can significantly improve patients’ ME and OHRQoL. The improvement in OHRQoL is mainly because of the improved ME. An improved chewing experience, and pain relief also contributes to improvement of OHRQoL. PMID:25316463

  14. Attracting, Developing and Retaining Effective Teachers: Background Report for the United States

    ERIC Educational Resources Information Center

    Walsh, Kate; Wilcox, Danielle; Palmaffy, Tyce; Tracy, Christopher; Yiamouyiannis, Zeus; Ostermeier, Amy; Garcia, Lenore Yaffee

    2004-01-01

    This report presents a balanced picture of the debate on teacher quality in the U.S. and focuses on the aspects of teacher policy dealing with attracting, recruiting, developing and retaining effective teachers by synthesizing relevant research, identifying innovative and successful policy practices, facilitating exchanges of lessons among…

  15. An Approach to Training and Retaining Primary Care Physicians in Rural Appalachia.

    ERIC Educational Resources Information Center

    Roberts, Allan; And Others

    1993-01-01

    The West Virginia School of Osteopathic Medicine's success in educating and retaining primary care physicians for practice in rural Appalachia is ascribed to its focused mission; a multistate student exchange program; careful recruitment, admission, and placement; early clinical training in rural sites; and status as a state-supported institution.…

  16. A case of severe caries and demineralisation in a patient wearing an essix-type retainer.

    PubMed

    Birdsall, Jo; Robinson, Stephen

    2008-04-01

    This case report presents a patient who developed significant caries and demineralisation due to consumption of large quantities of cariogenic drinks while he was wearing an Essix retainer. The risks to dental health during orthodontic retention and the responsibilities of general dental practitioners, orthodontists and patients are highlighted. PMID:18397593

  17. Effects of Hardness on Pintle Rod Performance in the Universal and Retained Gas Samplers

    SciTech Connect

    BOGER, R.M.

    1999-11-18

    Interaction between hardness of the pintle rods and the retainer rings used in the core samplers is investigated. It is found that ordinary Rockwell C measurements are not sufficient and superficial hardness instruments are recommended to verify hardness since in-production hardness of pintle rods is found to vary widely and probably leads to some premature release of pistons in samplers.

  18. Netting an Elusive Breed: How to Attract and Retain Better Teachers

    ERIC Educational Resources Information Center

    Warner, Mark R.

    2004-01-01

    The most important asset of any enterprise is the talent and enthusiasm of its workforce. In operating a successful business, there is no greater challenge than to attract and retain the best-qualified, hardest-working employees. And perhaps the most important factors in keeping the best people are providing workers with the tools to succeed at…

  19. Rubber and alumina gaskets retain vacuum seal in high temperature EMF cell

    NASA Technical Reports Server (NTRS)

    Hesson, J. C.

    1966-01-01

    Silicone rubber gasket and an alumina gasket retain a vacuum inside a high temperature EMF cell in which higher and lower density liquid metal electrodes are separated by an intermediate density fused salt electrolyte. This innovation is in use on a sodium bismuth regenerable EMF cell in which the fused salts and metals are at about 500 deg to 600 deg C.

  20. Recruiting and Retaining Learners in Workplace Literacy Programs in New Zealand

    ERIC Educational Resources Information Center

    Benseman, John

    2013-01-01

    Successful workplace literacy and numeracy programs are dependent on effective strategies to recruit and then retain course participants. This article reports on the recruitment strategies used in a large workplace literacy and numeracy project involving 535 workers in 18 courses. It provides an analysis of the strategies used, their rates of…

  1. Identifying, Recruiting, Developing, and Retaining Quality Adjunct Faculty in Rural Community Colleges in Ohio

    ERIC Educational Resources Information Center

    Wise, Jessica L.

    2013-01-01

    The purpose of this research was to determine how to identify, recruit, develop, and retain suitable adjunct faculty in rural community colleges in Ohio. The research problem resulted from a limited availability of potential faculty possessing the required credentials and andragogical training in Ohio's rural and Appalachian areas. Research…

  2. Compression retaining piston

    SciTech Connect

    Quaglino, A.V. Jr.

    1987-06-16

    A piston apparatus is described for maintaining compression between the piston wall and the cylinder wall, that comprises the following: a generally cylindrical piston body, including: a head portion defining the forward end of the body; and a continuous side wall portion extending rearward from the head portion; a means for lubricating and preventing compression loss between the side wall portion and the cylinder wall, including an annular recessed area in the continuous side wall portion for receiving a quantity of fluid lubricant in fluid engagement between the wall of the recessed and the wall of the cylinder; a first and second resilient, elastomeric, heat resistant rings positioned in grooves along the wall of the continuous side wall portion, above and below the annular recessed area. Each ring engages the cylinder wall to reduce loss of lubricant within the recessed area during operation of the piston; a first pump means for providing fluid lubricant to engine components other than the pistons; and a second pump means provides fluid lubricant to the recessed area in the continuous side wall portion of the piston. The first and second pump means obtains lubricant from a common source, and the second pump means including a flow line supplies oil from a predetermined level above the level of oil provided to the first pump means. This is so that should the oil level to the second pump means fall below the predetermined level, the loss of oil to the recessed area in the continuous side wall portion of the piston would result in loss of compression and shut down of the engine.

  3. Proactive Steps to Successfully Recruit, Retain, and Mentor Minority Educators. Issues in Education.

    ERIC Educational Resources Information Center

    Barnett, Ernest; Gibson, Meichelle; Black, Pam

    2003-01-01

    This article highlights strategies used at various Kentucky universities to recruit, retain, and mentor minority educators. Recruitment strategies include making staff diversity an institutional priority, involving enrolled minority students in recruiting others, and establishing a separate budget for minority candidate recruitment. Retention…

  4. Standing in the Gap: Research that Informs Strategies for Motivating and Retaining Rural High School Students

    ERIC Educational Resources Information Center

    Hardre, Patricia L.

    2012-01-01

    Rural schools face the challenges of motivating and retaining students, often in the face of severe resource constraints. This paper synthesizes fifteen years of the author's rural research on secondary students' school-related motivation, distilling it into strategic principles for rural teachers and administrators. Effective motivational…

  5. FOCUS: A State-Wide Initiative to Select and Retain Transition Teachers

    ERIC Educational Resources Information Center

    Cobia, Debra C.; Stephens, Cynthia E.; Sherer, Gail

    2015-01-01

    Through Focus on Change in Understanding Staff and Staffing Systems in Georgia Public Schools (FOCUS), over 500 teachers of record were recruited, selected, and placed in Georgia's high-need schools. Teachers in the first three cohorts were retained at very high levels as well as achieving full certification. Project outcomes also included the…

  6. Using New Social Media to Recruit and Retain Qualified Special Education Personnel. Practice Brief

    ERIC Educational Resources Information Center

    Muller, Eve

    2011-01-01

    As communication technologies continue to evolve at an ever-expanding rate, some states and localities are turning to new social media tools as a means of recruiting and retaining qualified education personnel. Based on examples from around the country drawn from early intervention (EI) programs, state education agencies (SEAs), local education…

  7. K-12 Education Nonprofit Employees' Perceptions of Strategies for Recruiting and Retaining Employees

    ERIC Educational Resources Information Center

    Byrne, Tara Marie

    2013-01-01

    This qualitative study explored the key reasons individuals who work in K-12 education nonprofit organizations enter the field of K-12 nonprofit education and their motivations for doing so. The purpose of this study was to find new strategies for recruiting and retaining K-12 education nonprofit employees by examining the obstacles that exist to…

  8. First Wall and Operational Diagnostics

    SciTech Connect

    Lasnier, C; Allen, S; Boedo, J; Groth, M; Brooks, N; McLean, A; LaBombard, B; Sharpe, J; Skinner, C; Whyte, D; Rudakov, D; West, W; Wong, C

    2006-06-19

    In this chapter we review numerous diagnostics capable of measurements at or near the first wall, many of which contribute information useful for safe operation of a tokamak. There are sections discussing infrared cameras, visible and VUV cameras, pressure gauges and RGAs, Langmuir probes, thermocouples, and erosion and deposition measurements by insertable probes and quartz microbalance. Also discussed are dust measurements by electrostatic detectors, laser scattering, visible and IR cameras, and manual collection of samples after machine opening. In each case the diagnostic is discussed with a view toward application to a burning plasma machine such as ITER.

  9. Case Report: retained gutta-percha as a cause for persistent maxillary sinusitis and pain

    PubMed Central

    Hodnett, Benjamin L.; Ferguson, Berrylin

    2014-01-01

    Dental sources of infection can produce acute and chronic maxillary sinusitis. In some cases, the source of the infection may be related to the presence of endodontic materials in the oral cavity. In this article, we report a case of retained gutta-percha in the maxillary sinus resulting in chronic sinusitis. PMID:24795809

  10. Tapping the Potential: Retaining and Developing High-Quality New Teachers

    ERIC Educational Resources Information Center

    Alliance for Excellent Education, 2010

    2010-01-01

    There is growing consensus that the single most important factor in determining student performance is the quality of the teacher. Therefore, if the national goal of providing an equitable education to children across this nation is to be met, it is critical that efforts be concentrated on developing and retaining high-quality teachers in every…

  11. E-Mentoring as a Means to Develop and Retain Expatriate Managers

    ERIC Educational Resources Information Center

    Wood, Evan D.

    2007-01-01

    As globalization increases, many corporations are faced with sending managers to foreign countries. With the increase in expatriate managers, a critical issue must be addressed--the high failure rate of expatriates. The literature shows mentoring to be a critical component in developing and retaining expatriate managers. The growing discipline of…

  12. Why Some Hope Scholarship Recipients Retain the Scholarship and Others Lose It

    ERIC Educational Resources Information Center

    Trant, Eleanore C.; Crabtree, Katelyn E.; Ciancio, Dennis J.; Hart, Leslie A.; Watson, Tiffany B.; Williams, Robert L.

    2015-01-01

    The study we report here examined parental, pre-course, and in-course predictors of students' probability of retaining (n = 136) or losing the HOPE scholarship (n = 41). The study was conducted in a multi-section, entry-level course (n = 203) for the Teacher-Education Program at a large state university in the southeastern U.S. Logistic regression…

  13. Reflections on Recruiting, Supporting, Retaining, Graduating, and Obtaining Employment for Doctoral Students from Diverse Backgrounds

    ERIC Educational Resources Information Center

    Dieker, Lisa; Wienke, Wilfred; Straub, Carrie; Finnegan, Lisa

    2014-01-01

    In this article, the authors provide a summary of the current techniques being used to recruit, retain, and support a diverse range of scholars, including students with disabilities, in a doctoral program. The manuscript provides a summary of the current need for leadership personnel who are scholars with knowledge in special education, general…

  14. 31 CFR 1021.410 - Additional records to be made and retained by casinos.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and Finance (Continued) FINANCIAL CRIMES ENFORCEMENT NETWORK, DEPARTMENT OF THE TREASURY RULES FOR... be maintained by § 1010.410 of this chapter or this section on computer disk, tape, or other machine-readable media shall retain the same on computer disk, tape, or machine-readable media. (2) All...

  15. 31 CFR 1021.410 - Additional records to be made and retained by casinos.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... and Finance (Continued) FINANCIAL CRIMES ENFORCEMENT NETWORK, DEPARTMENT OF THE TREASURY RULES FOR... be maintained by § 1010.410 of this chapter or this section on computer disk, tape, or other machine-readable media shall retain the same on computer disk, tape, or machine-readable media. (2) All...

  16. Finite element analysis to compare complete denture and implant-retained overdentures with different attachment systems.

    PubMed

    Barão, Valentim Adelino Ricardo; Assunção, Wirley Gonçalves; Tabata, Lucas Fernando; Delben, Juliana Aparecida; Gomes, Erica Alves; de Sousa, Edson Antonio Capello; Rocha, Eduardo Passos

    2009-07-01

    This finite element analysis compared stress distribution on complete dentures and implant-retained overdentures with different attachment systems. Four models of edentulous mandible were constructed: group A (control), complete denture; group B, overdenture retained by 2 splinted implants with bar-clip system; group C, overdenture retained by 2 unsplinted implants with o'ring system; and group D, overdenture retained by 2 splinted implants with bar-clip and 2 distally placed o'ring system. Evaluation was performed on Ansys software, with 100-N vertical load applied on central incisive teeth. The lowest maximum general stress value (in megapascal) was observed in group A (64.305) followed by groups C (119.006), D (258.650), and B (349.873). The same trend occurred in supporting tissues with the highest stress value for cortical bone. Unsplinted implants associated with the o'ring attachment system showed the lowest maximum stress values among all overdenture groups. Furthermore, o'ring system also improved stress distribution when associated with bar-clip system. PMID:19553853

  17. A comparative study on complete and implant retained denture treatments: a biomechanics perspective.

    PubMed

    Chen, Junning; Ahmad, Rohana; Suenaga, Hanako; Li, Wei; Swain, Michael; Li, Qing

    2015-02-01

    Although implant-retained overdenture allows edentulous patients to take higher occlusal forces than the conventional complete dentures, the biomechanical influences have not been explored yet. Clinically, there is limited knowledge and means for predicting localized bone remodelling after denture treatment with and without implant support. By using finite element (FE) analysis, this article provides an in-silico approach to exploring the treatment effects on the oral mucosa and potential resorption of residual ridge under three different denture configurations in a patient-specific manner. Based on cone beam computerized tomography (CBCT) scans, a 3D heterogeneous FE model was created; and the supportive tissue, mucosa, was characterized as a hyperelastic material. A measured occlusal load (63N) was applied onto three virtual models, namely complete denture, two and four implant-retained overdentures. Clinically, the bone resorption was measured after one year in the two implant-retained overdenture treatment. Despite the improved stability and enhanced masticatory function, the implant-retained overdentures demonstrated higher hydrostatic stress in mucosa (43.6kPa and 39.9kPa for two and four implants) at the posterior ends of the mandible due to the cantilever effect, than the complete denture (33.4kPa). Hydrostatic pressure in the mucosa signifies a critical indicator and can be correlated with clinically measured bone resorption, pointing to severer mandibular ridge resorption posteriorly with implant-retained overdentures. This study provides a biomechanical basis for denture treatment planning to improve long-term outcomes with minimal residual ridge resorption. PMID:25560272

  18. Neuroblastoma patient-derived orthotopic xenografts retain metastatic patterns and geno- and phenotypes of patient tumours

    PubMed Central

    Braekeveldt, Noémie; Wigerup, Caroline; Gisselsson, David; Mohlin, Sofie; Merselius, My; Beckman, Siv; Jonson, Tord; Börjesson, Anna; Backman, Torbjörn; Tadeo, Irene; Berbegall, Ana P; Öra, Ingrid; Navarro, Samuel; Noguera, Rosa; Påhlman, Sven; Bexell, Daniel

    2015-01-01

    Neuroblastoma is a childhood tumour with heterogeneous characteristics and children with metastatic disease often have a poor outcome. Here we describe the establishment of neuroblastoma patient-derived xenografts (PDXs) by orthotopic implantation of viably cryopreserved or fresh tumour explants of patients with high risk neuroblastoma into immunodeficient mice. In vivo tumour growth was monitored by magnetic resonance imaging and fluorodeoxyglucose–positron emission tomography. Neuroblastoma PDXs retained the undifferentiated histology and proliferative capacity of their corresponding patient tumours. The PDXs expressed neuroblastoma markers neural cell adhesion molecule, chromogranin A, synaptophysin and tyrosine hydroxylase. Whole genome genotyping array analyses demonstrated that PDXs retained patient-specific chromosomal aberrations such as MYCN amplification, deletion of 1p and gain of chromosome 17q. Thus, neuroblastoma PDXs recapitulate the hallmarks of high-risk neuroblastoma in patients. PDX-derived cells were cultured in serum-free medium where they formed free-floating neurospheres, expressed neuroblastoma gene markers MYCN, CHGA, TH, SYP and NPY, and retained tumour-initiating and metastatic capacity in vivo. PDXs showed much higher degree of infiltrative growth and distant metastasis as compared to neuroblastoma SK-N-BE(2)c cell line-derived orthotopic tumours. Importantly, the PDXs presented with bone marrow involvement, a clinical feature of aggressive neuroblastoma. Thus, neuroblastoma PDXs serve as clinically relevant models for studying and targeting high-risk metastatic neuroblastoma. What's new? Neuroblastoma is a childhood tumour with heterogeneous characteristics and children with metastatic disease have a poor outcome. Here, the authors established neuroblastoma patient-derived xenografts (PDXs) by orthotopic implantation of viably cryopreserved or fresh tumour explants of patients with high-risk neuroblastoma into immunodeficient mice

  19. Polyurethane retainers for ball bearings

    NASA Technical Reports Server (NTRS)

    Christy, R. I.

    1973-01-01

    Evaluation of a new ball bearing retainer material is reported. A special composite polyurethane foam ball retainer has been developed that has virtually zero wear, is chemically inert to hydrocarbon lubricants, and stores up to 60 times as much lubricant per unit volume as the most commonly used retainer material, cotton phenolic. This new retainer concept shows promise of years of ball bearing operation without reoiling, based on life testing in high vacuum.

  20. Rock Mass Behavior Under Hydropower Embankment Dams: A Two-Dimensional Numerical Study

    NASA Astrophysics Data System (ADS)

    Bondarchuk, A.; Ask, M. V. S.; Dahlström, L.-O.; Nordlund, E.

    2012-09-01

    Sweden has more than 190 large hydropower dams, of which about 50 are pure embankment dams and over 100 are concrete/embankment dams. This paper presents results from conceptual analyses of the response of typical Swedish rock mass to the construction of a hydropower embankment dam and its first stages of operation. The aim is to identify locations and magnitudes of displacements that are occurring in the rock foundation and grout curtain after construction of the dam, the first filling of its water reservoir, and after one seasonal variation of the water table. Coupled hydro-mechanical analysis was conducted using the two-dimensional distinct element program UDEC. Series of the simulations have been performed and the results show that the first filling of the reservoir and variation of water table induce largest magnitudes of displacement, with the greatest values obtained from the two models with high differential horizontal stresses and smallest spacing of sub-vertical fractures. These results may help identifying the condition of the dam foundation and contribute to the development of proper maintenance measures, which guarantee the safety and functionality of the dam. Additionally, newly developed dams may use these results for the estimation of the possible response of the rock foundation to the construction.

  1. [Diagnosis and therapy of retained fetal membranes, puerperal metritis and clinical endometritis in cattle: Results of the Online-survey among Swiss practitioners. I Retained fetal membranes].

    PubMed

    Hehenberger, E M; Doherr, M G; Bodmer, M; Steiner, A; Hirsbrunner, G

    2015-09-01

    The aim of this study was to obtain the diagnostic and therapeutic approach among Swiss practitioners in cows with retained fetal membranes (RFM) (part 1). All members of the Association for ruminant health were contacted per email via the newsletter. The survey was completed by 128 veterinarians, partially responded by 140 veterinarians. The manual removal of the fetal membranes is practiced by 129 of the responding veterinarians. Cows with/without fever are treated usually with intrauterine antibiotics. Cows with RFM with/without fever are most commonly treated parenterally with tetracycline or penicillin. The use of cephalosporins and quinolones in cows with fever is more common than in cows without fever. With the present results of the survey veterinarians should critically question the supposed benefits of the manual removal of the placenta and the use of antibiotics in cows with RFM. PMID:26757590

  2. RETAIN Act

    THOMAS, 112th Congress

    Rep. Baca, Joe [D-CA-43

    2012-05-08

    09/26/2012 Referred to the Subcommittee on Early Childhood, Elementary, and Secondary Education. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

  3. Science and Mathematics Alliance for Recruiting and Retaining Teachers (SMARRT): Addressing the Teacher Shortage in At-Risk Schools

    ERIC Educational Resources Information Center

    Staudt, Denise; Risku, Michael; Martinez, Elda

    2008-01-01

    The Science and Mathematics Alliance for Recruiting and Retaining Teachers (SMARRT) is a collaborative partnership pursuing aggressive strategies to recruit high quality minority teachers to teach in high-need schools in urban school districts. This partnership is dedicated to recruiting, preparing, and retaining high quality teachers with strong…

  4. Monitoring of railway embankment settlement with fiber-optic pulsed time-of-flight radar

    NASA Astrophysics Data System (ADS)

    Kilpelä, Ari; Lyöri, Veijo; Duan, Guoyong

    2012-12-01

    This paper deals with a fiber-optic pulsed time-of-flight (PTOF) laser radar used for monitoring the settlement of a railway embankment. The operating principle is based on evaluating the changes in the lengths of the fiber-optic cables embedded in the embankment by measuring the time separation of the optical pulses reflected from both ends of the sensor fiber. The advantage of this method is that it integrates the elongation of the whole sensor, and many sensor fibers can be connected in series. In a field test, seven polyurethane-coated optical cables were installed in a railway embankment and used as 20-m long sensors. The optical timing pulses were created using specially polished optical connectors. The measured precision was 0.28 ps, which corresponds 1.8 μstrain elongation using a 20 m long sensor fiber, using an averaged value of 10 000 pulses for a single measurement value. The averaged elongation value of all sensors was used for cancelling out the effect of temperature variation on the elongation value of each individual sensor. The functionality of the method was tested by digging away a 7.5 m long and approximately 18 mm high section of sand below one sensor. It was measured as a +3 mm change in the length of the sensor fiber, which matched well with the theoretically calculated elongation value, 2.9 mm. The sensor type proved to be strong but flexible enough for this type of use.

  5. A simulation-optimization model for Stone column-supported embankment stability considering rainfall effect

    NASA Astrophysics Data System (ADS)

    Deb, Kousik; Dhar, Anirban; Purohit, Sandip

    2016-02-01

    Landslide due to rainfall has been and continues to be one of the most important concerns of geotechnical engineering. The paper presents the variation of factor of safety of stone column-supported embankment constructed over soft soil due to change in water level for an incessant period of rainfall. A combined simulation-optimization based methodology has been proposed to predict the critical surface of failure of the embankment and to optimize the corresponding factor of safety under rainfall conditions using an evolutionary genetic algorithm NSGA-II (Non-Dominated Sorted Genetic Algorithm-II). It has been observed that the position of water table can be reliably estimated with varying periods of infiltration using developed numerical method. The parametric study is presented to study the optimum factor of safety of the embankment and its corresponding critical failure surface under the steady-state infiltration condition. Results show that in case of floating stone columns, period of infiltration has no effect on factor of safety. Even critical failure surfaces for a particular floating column length remain same irrespective of rainfall duration.

  6. Surgical management for retained distal embolic protection device and fractured guidewire after carotid artery stenting.

    PubMed

    Li, Tongxun; Zha, Yuanting; Bo, Liyang; Wirthlin, Douglas J; Zhang, Qinyi

    2016-01-01

    Entrapment and fracture of carotid angioplasty and stenting hardware is a rare complication of percutaneous stenting procedures. We describe a case of a retained distal filter embolic protection device and guidewire in a 57-year-old male in Beijing, China. After unsuccessful attempts at removal via interventional methods, a second stent was deployed to secure the original hardware in situ, and the patient was discharged. He later experienced guidewire fragmentation in the carotid artery and aortic arch, with subsequent thrombus formation. We report partial removal of the guidewire and stent via carotid artery cutdown and open thoracotomy without complication. When efforts to retrieve stenting hardware are unsuccessful, it is never a suitable choice to leave them within the artery. We advocate for early surgical management of retained materials after unsuccessful carotid artery stenting. Furthermore, improved quality monitoring and assurance programs are needed to prevent such complications in the future. PMID:27316621

  7. Retaining and assisting nontraditional nursing students in a baccalaureate nursing program utilizing Blackboard & Tegrity technologies.

    PubMed

    Merrill, Earlene B; Reinckens, Tina; Yarborough, Mildred; Robinson, Vaple I

    2006-01-01

    Historically Black College and University (HBCU) implemented new teaching methodologies that incorporate both technology and face-to-face teaching as a means of assisting and retaining the non-traditional student. Teaching strategies were enhanced through a new instructional delivery method, Tegrity. The course, Introduction to Nursing Process I, was transformed to a hybrid on-line course using Blackboard and Tegrity. Its transformation reflected inherent strengths when faculty used a systematic approach and implemented a strong team effort. A team approach including collaboration on lecture content and shared PowerPoint presentations in all sections of the course facilitated consistency in the course content. A conceptual model, which included a systems approach that encourages student involvement, was actualized throughout the project. This article utilizes a descriptive approach and explains what faculty did to retain and assist the 157 newly admitted non-traditional baccalaureate nursing students using two technological methods. PMID:16948363

  8. Surgical management for retained distal embolic protection device and fractured guidewire after carotid artery stenting

    PubMed Central

    Li, Tongxun; Zha, Yuanting; Bo, Liyang; Wirthlin, Douglas J.; Zhang, Qinyi

    2016-01-01

    Entrapment and fracture of carotid angioplasty and stenting hardware is a rare complication of percutaneous stenting procedures. We describe a case of a retained distal filter embolic protection device and guidewire in a 57-year-old male in Beijing, China. After unsuccessful attempts at removal via interventional methods, a second stent was deployed to secure the original hardware in situ, and the patient was discharged. He later experienced guidewire fragmentation in the carotid artery and aortic arch, with subsequent thrombus formation. We report partial removal of the guidewire and stent via carotid artery cutdown and open thoracotomy without complication. When efforts to retrieve stenting hardware are unsuccessful, it is never a suitable choice to leave them within the artery. We advocate for early surgical management of retained materials after unsuccessful carotid artery stenting. Furthermore, improved quality monitoring and assurance programs are needed to prevent such complications in the future. PMID:27316621

  9. Young children retain fast mapped object labels better than shape, color, and texture words.

    PubMed

    Holland, Amanda; Simpson, Andrew; Riggs, Kevin J

    2015-06-01

    We compared short- and long-term retention of fast mapped color, shape, and texture words as well as object labels. In an exposure session, 354 3- and 4-year-old children were shown a set of two familiar and three novel stimuli. One of the novel stimuli was labeled with a new object label, color, shape, or texture word. Retention of the mapping between the new word and the novel object or property was measured either 5 min or 1 week later. After 5 min, retention was significantly above chance in all conditions. However, after 1 week, only the mappings for object labels were retained above chance levels. Our findings suggest that fast mapped object labels are retained long term better than color, shape, and texture words. The results also highlight the importance of comparing short- and long-term retention when studying children's word learning. PMID:25765990

  10. Direct calculation of wall interferences and wall adaptation for two-dimensional flow in wind tunnels with closed walls

    NASA Technical Reports Server (NTRS)

    Amecke, Juergen

    1986-01-01

    A method for the direct calculation of the wall induced interference velocity in two dimensional flow based on Cauchy's integral formula was derived. This one-step method allows the calculation of the residual corrections and the required wall adaptation for interference-free flow starting from the wall pressure distribution without any model representation. Demonstrated applications are given.

  11. The dinoflagellates Durinskia baltica and Kryptoperidinium foliaceum retain functionally overlapping mitochondria from two evolutionarily distinct lineages

    PubMed Central

    Imanian, Behzad; Keeling, Patrick J

    2007-01-01

    Background The dinoflagellates Durinskia baltica and Kryptoperidinium foliaceum are distinguished by the presence of a tertiary plastid derived from a diatom endosymbiont. The diatom is fully integrated with the host cell cycle and is so altered in structure as to be difficult to recognize it as a diatom, and yet it retains a number of features normally lost in tertiary and secondary endosymbionts, most notably mitochondria. The dinoflagellate host is also reported to retain mitochondrion-like structures, making these cells unique in retaining two evolutionarily distinct mitochondria. This redundancy raises the question of whether the organelles share any functions in common or have distributed functions between them. Results We show that both host and endosymbiont mitochondrial genomes encode genes for electron transport proteins. We have characterized cytochrome c oxidase 1 (cox1), cytochrome oxidase 2 (cox2), cytochrome oxidase 3 (cox3), cytochrome b (cob), and large subunit of ribosomal RNA (LSUrRNA) of endosymbiont mitochondrial ancestry, and cox1 and cob of host mitochondrial ancestry. We show that all genes are transcribed and that those ascribed to the host mitochondrial genome are extensively edited at the RNA level, as expected for a dinoflagellate mitochondrion-encoded gene. We also found evidence for extensive recombination in the host mitochondrial genes and that recombination products are also transcribed, as expected for a dinoflagellate. Conclusion Durinskia baltica and K. foliaceum retain two mitochondria from evolutionarily distinct lineages, and the functions of these organelles are at least partially overlapping, since both express genes for proteins in electron transport. PMID:17892581

  12. Moss cell walls: structure and biosynthesis

    PubMed Central

    Roberts, Alison W.; Roberts, Eric M.; Haigler, Candace H.

    2012-01-01

    The genome sequence of the moss Physcomitrella patens has stimulated new research examining the cell wall polysaccharides of mosses and the glycosyl transferases that synthesize them as a means to understand fundamental processes of cell wall biosynthesis and plant cell wall evolution. The cell walls of mosses and vascular plants are composed of the same classes of polysaccharides, but with differences in side chain composition and structure. Similarly, the genomes of P. patens and angiosperms encode the same families of cell wall glycosyl transferases, yet, in many cases these families have diversified independently in each lineage. Our understanding of land plant evolution could be enhanced by more complete knowledge of the relationships among glycosyl transferase functional diversification, cell wall structural and biochemical specialization, and the roles of cell walls in plant adaptation. As a foundation for these studies, we review the features of P. patens as an experimental system, analyses of cell wall composition in various moss species, recent studies that elucidate the structure and biosynthesis of cell wall polysaccharides in P. patens, and phylogenetic analysis of P. patens genes potentially involved in cell wall biosynthesis. PMID:22833752

  13. Hepatocellular carcinoma cell lines retain the genomic and transcriptomic landscapes of primary human cancers

    PubMed Central

    Qiu, Zhixin; Zou, Keke; Zhuang, Liping; Qin, Jianjie; Li, Hong; Li, Chao; Zhang, Zhengtao; Chen, Xiaotao; Cen, Jin; Meng, Zhiqiang; Zhang, Haibin; Li, Yixue; Hui, Lijian

    2016-01-01

    Hepatocellular carcinoma (HCC) cell lines are useful in vitro models for the study of primary HCCs. Because cell lines acquire additional mutations in culture, it is important to understand to what extent HCC cell lines retain the genetic landscapes of primary HCCs. Most HCC cell lines were established during the last century, precluding comparison between cell lines and primary cancers. In this study, 9 Chinese HCC cell lines with matched patient-derived cells at low passages (PDCs) were established in the defined culture condition. Whole genome analyses of 4 HCC cell lines showed that genomic mutation landscapes, including mutations, copy number alterations (CNAs) and HBV integrations, were highly stable during cell line establishment. Importantly, genetic alterations in cancer drivers and druggable genes were reserved in cell lines. HCC cell lines also retained gene expression patterns of primary HCCs during in vitro culture. Finally, sequential analysis of HCC cell lines and PDCs at different passages revealed their comparable and stable genomic and transcriptomic levels if maintained within proper passages. These results show that HCC cell lines largely retain the genomic and transcriptomic landscapes of primary HCCs, thus laying the rationale for testing HCC cell lines as preclinical models in precision medicine. PMID:27273737

  14. Hepatocellular carcinoma cell lines retain the genomic and transcriptomic landscapes of primary human cancers.

    PubMed

    Qiu, Zhixin; Zou, Keke; Zhuang, Liping; Qin, Jianjie; Li, Hong; Li, Chao; Zhang, Zhengtao; Chen, Xiaotao; Cen, Jin; Meng, Zhiqiang; Zhang, Haibin; Li, Yixue; Hui, Lijian

    2016-01-01

    Hepatocellular carcinoma (HCC) cell lines are useful in vitro models for the study of primary HCCs. Because cell lines acquire additional mutations in culture, it is important to understand to what extent HCC cell lines retain the genetic landscapes of primary HCCs. Most HCC cell lines were established during the last century, precluding comparison between cell lines and primary cancers. In this study, 9 Chinese HCC cell lines with matched patient-derived cells at low passages (PDCs) were established in the defined culture condition. Whole genome analyses of 4 HCC cell lines showed that genomic mutation landscapes, including mutations, copy number alterations (CNAs) and HBV integrations, were highly stable during cell line establishment. Importantly, genetic alterations in cancer drivers and druggable genes were reserved in cell lines. HCC cell lines also retained gene expression patterns of primary HCCs during in vitro culture. Finally, sequential analysis of HCC cell lines and PDCs at different passages revealed their comparable and stable genomic and transcriptomic levels if maintained within proper passages. These results show that HCC cell lines largely retain the genomic and transcriptomic landscapes of primary HCCs, thus laying the rationale for testing HCC cell lines as preclinical models in precision medicine. PMID:27273737

  15. Root canal retained restorations: 1. General considerations and custom-made cast posts and cores.

    PubMed

    Edmunds, D H; Dummer, P M

    1990-06-01

    The first article in this series reviews general considerations relating to the use of root canal retained restorations. The authors discuss factors affecting retention, the arguments for cast versus wrought posts, reinforcement of the tooth, and treatment planning. Clinical procedures for constructing custom-made cast posts and cores, using direct and indirect techniques, are also described. The three subsequent articles will deal with threaded and unthreaded prefabricated post-and-core systems, and root-face attachments for the retention of complete and partial overdentures. PMID:2079151

  16. Knowledge and practice of implant-retained restorations among dental students in Saudi Arabia

    PubMed Central

    Vohra, Fahim; Shah, Altaf Hussain; Zafar, Mohammad Sohail; Kola, Zaheer

    2015-01-01

    Objectives: The aim of the study was to assess the knowledge and practice of implant retained restorations (IRR) among senior dental students in Saudi Arabia. Methods: Four hundred questionnaires were distributed among senior dental students of five dental schools in Saudi Arabia. Student’s knowledge was assessed regarding which implant restoration [cement retained restoration (CRR) or screw retained restoration (SRR)] better provides the desired clinical properties. Students’ practice of IRR, perception of their knowledge and need for further education related to IRR were also assessed. Descriptive statistics and chi-square test were employed to assess collected data. Results: Three hundred and fifty four senior dental students responded at a response rate of 88.5%. Thirty three percent respondents did not have any practical experience of IRR. Students showed a clear preference for CRR with regards to aesthetics (71.4%), passive fit (55.3%), fabrication ease (57.3%) and fracture resistance (40%). SRR were considered to provide better retention (59.6%), soft tissue health (51.1%) and ease of retrievability (72%). Nearly 40% of students agreed that they did not get sufficient information related to IRR in undergraduate courses. Conclusions: Clinical training of IRR is compromised in the undergraduate curriculum in dental schools of Saudi Arabia. The knowledge of dental students regarding IRR was broadly in line with current evidence. PMID:26430416

  17. Measuring air layer volumes retained by submerged floating-ferns Salvinia and biomimetic superhydrophobic surfaces.

    PubMed

    Mayser, Matthias J; Bohn, Holger F; Reker, Meike; Barthlott, Wilhelm

    2014-01-01

    Some plants and animals feature superhydrophobic surfaces capable of retaining a layer of air when submerged under water. Long-term air retaining surfaces (Salvinia-effect) are of high interest for biomimetic applications like drag reduction in ship coatings of up to 30%. Here we present a novel method for measuring air volumes and air loss under water. We recorded the buoyancy force of the air layer on leaf surfaces of four different Salvinia species and on one biomimetic surface using a highly sensitive custom made strain gauge force transducer setup. The volume of air held by a surface was quantified by comparing the buoyancy force of the specimen with and then without an air layer. Air volumes retained by the Salvinia-surfaces ranged between 0.15 and 1 L/m(2) depending on differences in surface architecture. We verified the precision of the method by comparing the measured air volumes with theoretical volume calculations and could find a good agreement between both values. In this context we present techniques to calculate air volumes on surfaces with complex microstructures. The introduced method also allows to measure decrease or increase of air layers with high accuracy in real-time to understand dynamic processes. PMID:24991518

  18. On milling of thin-wall conical and tubular workpieces

    NASA Astrophysics Data System (ADS)

    Tsai, Mu-Ping; Tsai, Nan-Chyuan; Yeh, Cheng-Wei

    2016-05-01

    Thin-wall tubular-geometry workpieces have been widely applied in aircraft and medical industries. However, due to the special geometry of this kind of workpieces and induced poor machinability, the desired accuracy of machining tends to be greatly degraded, no matter what type of metal-cutting task such as milling, drilling or turning is undertaken. Though numerous research reports are available that the tool path can be planned on the basis of preset surface profile before actual milling operation is performed, it is still difficult to predict the real-time surface profile errors for peripheral milling of thin-wall tubular workpieces. Instead of relying on tool path planning, this research is focused on how to real-time formulate the appropriate applied cutting torque via feedback of spindle motor current. On the other hand, a few suitable cutting conditions which are able to prevent potential break/crack of thin-wall workpieces and enhance productivity but almost retain the same cutting quality is proposed in this research. To achieve this goal, estimated surface profile error on machined parts due to deflections caused by both tool and workpiece is studied at first. Traditionally, by adjusting cutting parameters such as feed rate or cut depth, the deflection of tool or workpiece can be expected not to exceed the specified limit. Instead, an effective feedback control loop is proposed by this work for applying real-time appropriate applied cutting torque to prevent potential break/crack of the thin-wall conical workpieces. The torque estimation approach by spindle motor current feedback and the corresponding fuzzy logic controller are employed. Compared with constant cutting torque during milling operation in tradition manner, it is observed that the time consumption of milling cycle by aid of the aforesaid fuzzy logic controller is greatly shortened while the resulted cutting accuracy upon finish of workpiece can be almost retained.

  19. On the reaction pathways and determination of transition-state structures for retaining alpha-galactosyltransferases.

    PubMed

    André, Isabelle; Tvaroska, Igor; Carver, Jeremy P

    2003-04-22

    The catalytic mechanism of retaining glycosyltransferases is not yet completely understood, but one possible mechanism, by analogy with retaining glycosidases, is a double-displacement mechanism via a covalent glycosyl-enzyme intermediate (CGE). We have investigated various reaction pathways for this mechanism using non-empirical quantum mechanical methods. Because a double-displacement mechanism presumes a reaction happening in two steps, we have used predefined reaction coordinates to calculate the potential energy surface describing each step of the mechanism. By investigating several potential candidates to act as a catalytic base, this study attempts to shed some light on the unclear mechanism of the second step of the reaction. All intermediates and transition states on the reaction pathways were characterized using basis sets up to the DFT/B3LYP/6-311++G**//DFT/B3LYP/6-31G* level. Reaction pathways and structural changes were compared with the results previously obtained for inverting glycosyltransferases. The outcome of this study indicates, that among the reaction models investigated, the energetically favorable one is also the most plausible given the existing experimental data. This model requires the presence of only one catalytic acid in the active site with the UDP functioning as a general base in the second step of the reaction. This mechanism is in agreement with both kinetic data in the literature and the description of X-ray structures of retaining glycosyltransferases solved up to today. PMID:12681911

  20. Leukotriene B4 in cows with normal calving, and in cows with retained fetal membranes and/or uterine subinvolution.

    PubMed Central

    Slama, H; Vaillancourt, D; Goff, A K

    1993-01-01

    Two experiments were performed to study the relationship between leukotriene B4 (LTB4) synthesis and placental separation and uterine involution in the cow. In experiment I, the concentration and synthesis of LTB4 by caruncular tissue was lower in cows with retained fetal membranes (RFM cows, n = 11) than in cows that expelled the fetal membranes normally (NFM cows, n = 19). The presence of bacterial cell wall, especially of alpha-hemolytic streptococci and coagulase positive staphylococci enhanced LTB4 synthesis by allantochorion only in NFM cows. In the RFM group, Escherichia coli lipopolysaccharide decreased allantochorionic LTB4 synthesis. With caruncle, only epidermal growth factor increased LTB4 production in NFM cows. In experiment II, the caruncular and endometrial secretion of LTB4 was lower in cows with subuterine involution (SUI cows, n = 5) or cows with SUI and RFM (SUI+RFM cows, n = 4) than in cows with normal uterine involution (NUI cows, n = 8). This decrease was especially noticeable in the previously gravid horn. In the three uterine involution groups, there were no differences in LTB4 synthesis by caruncular tissue taken from the previously gravid horn. However, progesterone and a bacterial suspension of E. coli reduced the synthesis of LTB4. Estradiol had no effect on LTB4 synthesis at the end of the postpartum period. These results suggest that LTB4 may play an important role in both placental separation and uterine involution in cattle and LTB4 synthesis may be modulated by endocrine and bacterial factors. PMID:8269369

  1. The retained surgical sponge.

    PubMed Central

    Kaiser, C W; Friedman, S; Spurling, K P; Slowick, T; Kaiser, H A

    1996-01-01

    OBJECTIVE. A review was performed to investigate the frequency of occurrence and outcome of patients who have retained surgical sponges. METHODS. Closed case records from the files of the Medical Professional Mutual Insurance Company (ProMutual, Boston, MA) involving a claim of retained surgical sponges were reviewed for a 7-year period. RESULTS. Retained sponges occurred in 40 patients, comprising 48% of all closed claims for retained foreign bodies. A falsely correct sponge count after an abdominal procedure was documented in 76% of these claims. Ten percent of claims involved vaginal deliveries and minor non-body cavity procedures, for which no sponge count was performed. Total indemnity payments were $2,072,319, and defense costs were $572,079. In three cases, the surgeon was deemed responsible by the court despite the nursing staff's admitting liability and evidence presented that the surgeon complied completely with the standard of care. A wide range of indemnity payments was made despite a remarkable similarity of outcome in the patients studied. CONCLUSIONS. Despite the rarity of the reporting of a retained surgical sponge, this occurrence appears to be encountered more commonly than generally is appreciated. Operating teams should ensure that sponges be counted for all vaginal and any incisional procedures at risk for retaining a sponge. In addition, the surgeon should not unquestioningly accept correct count reports, but should develop the habit of performing a brief but thorough routine postprocedure wound/body cavity exploration before wound closure. The strikingly similar outcome for most patients would argue for a standardized indemnity payment being made without the need for adversarial legal procedures. PMID:8678622

  2. Reliability assessment of granular filters in embankment dams

    NASA Astrophysics Data System (ADS)

    Mínguez, Roberto; Delgado, Fernando; Escuder, Ignacio; de Membrillera, Manuel G.

    2006-08-01

    Empirical criteria have been used successfully to design filters of most embankment large dam projects throughout the world. However, these empirical rules are only applicable to a particular range of soils tested in laboratory and do not take into account the variability of the base material and filter particle sizes. In addition, it is widely accepted that the safety of fill dams is mainly dependent on the reliability of their filter performance. The work herein presented consists in a new general method for assessing the probability of fulfilling any empirical filter design criteria accounting for base and filter heterogeneity by means of first-order reliability methods (FORM), so that reliability indexes and probabilities of fulfilling any particular criteria are obtained. This method will allow engineers to estimate the safety of existing filters in terms of probability of fulfilling their design criteria and might also be used as a decision tool on sampling needs and material size tolerances during construction. In addition, sensitivity analysis makes possible to analyse how reliabilities are influenced by different sources of input data. Finally, in case of a portfolio risk assessment, this method will allow engineers to compare the safety of several existing dams in order to prioritize safety investments and it is expected to be a very useful tool to evaluate probabilities of failure due to internal erosion.

  3. Experimental investigation of wall shock cancellation and reduction of wall interference in transonic testing

    NASA Technical Reports Server (NTRS)

    Ferri, A.; Roffe, G.

    1975-01-01

    A series of experiments were performed to evaluate the effectiveness of a three-dimensional land and groove wall geometry and a variable permeability distribution to reduce the interference produced by the porous walls of a supercritical transonic test section. The three-dimensional wall geometry was found to diffuse the pressure perturbations caused by small local mismatches in wall porosity permitting the use of a relatively coarse wall porosity control to reduce or eliminate wall interference effects. The wall porosity distribution required was found to be a sensitive function of Mach number requiring that the Mach number repeatability characteristics of the test apparatus be quite good. The effectiveness of a variable porosity wall is greatest in the upstream region of the test section where the pressure differences across the wall are largest. An effective variable porosity wall in the down stream region of the test section requires the use of a slightly convergent test section geometry.

  4. Attracting and Retaining Adult Learners (ARAL). A Compilation of Selected Program Descriptions Taken from the 1980 ARAL Survey.

    ERIC Educational Resources Information Center

    American Coll. Testing Program, Iowa City, IA. National Center for the Advancement of Educational Practices.

    A catalog of 205 descriptions of college programs to recruit and retain adult learners is presented, based on a national survey, "Attracting and Retaining Adult Learners" (ARAL), conducted in 1980 by the American College Testing Program. In addition to a brief program description, each program form provides information on the type of program, the…

  5. Correlation between mechanical properties and retained austenite characteristics in a low-carbon medium manganese alloyed steel plate

    SciTech Connect

    Chen, Jun; Lv, Mengyang; Tang, Shuai; Liu, Zhenyu; Wang, Guodong

    2015-08-15

    The effects of retained austenite characteristics on tensile properties and low-temperature impact toughness have been investigated by means of transmission electron microscopy and X-ray diffraction. It was found that only part of austenite phase formed during heat treating was left at room temperature. Moreover, the film-like retained austenite is displayed between bcc-martensite laths after heat treating at 600 °C, while the block-form retained austenite with thin hcp-martensite laths is observed after heat treating at 650 °C. It has been demonstrated that the film-like retained austenite possesses relatively high thermal and mechanical stability, and it can greatly improve low-temperature impact toughness, but its contribution to strain hardening capacity is limited. However, the block-form retained austenite can greatly enhance ultimate tensile strength and strain hardening capacity, but its contribution to low-temperature impact toughness is poor. - Highlights: • Correlation between retained austenite and impact toughness was elucidated. • The impact toughness is related to mechanical stability of retained austenite. • The effect of retained austenite on tensile and impact properties is inconsistent.

  6. Architecture of dermatophyte cell Walls: Electron microscopic and biochemical analysis

    NASA Technical Reports Server (NTRS)

    Nozawa, Y.; Kitajima, Y.

    1984-01-01

    A review with 83 references on the cell wall structure of dermatophytes is presented. Topics discussed include separation and preparation of cell walls; microstructure of cell walls by electron microscopy; chemical composition of cell walls; structural model of cell walls; and morphological structure of cell walls.

  7. The formation and evolution of domain walls

    NASA Technical Reports Server (NTRS)

    Press, William H.; Ryden, Barbara S.; Spergel, David N.

    1991-01-01

    Domain walls are sheet-like defects produced when the low energy vacuum has isolated degenerate minima. The researchers' computer code follows the evolution of a scalar field, whose dynamics are determined by its Lagrangian density. The topology of the scalar field determines the evolution of the domain walls. This approach treats both wall dynamics and reconnection. The researchers investigated not only potentials that produce single domain walls, but also potentials that produce a network of walls and strings. These networks arise in axion models where the U(1) Peccei-Quinn symmetry is broken into Z sub N discrete symmetries. If N equals 1, the walls are bounded by strings and the network quickly disappears. For N greater than 1, the network of walls and strings behaved qualitatively just as the wall network shown in the figures given here. This both confirms the researchers' pessimistic view that domain walls cannot play an important role in the formation of large scale structure and implies that axion models with multiple minimum can be cosmologically disastrous.

  8. Kinematics and Mechanical Properties of Knees following Patellar Replacing and Patellar Retaining Total Knee Arthroplasty

    PubMed Central

    Huang, Rongying; Liu, Yanqiang; Zhu, Jun

    2015-01-01

    Knee injury is a common medical issue. A full understanding of the kinematics and mechanical properties of knees following total knee arthroplasty (TKA) repair utilizing patellar replacement (only the base of the patella is replaced) versus patellar retaining surgical techniques is still lacking. In the current paper, we investigated magnetic resonance (MR) imaging data from knees repaired by these two methods and evaluated total knee models created using imaging reconstruction technology that simulated gait conditions. Results revealed that patellar replacement had little influence on tibiofemoral kinematics, although the tibia-surface equivalent stress increased slightly. By contrast, patellar replacement had a significant influence on the patellofemoral joint; patellar internal rotation, external rotation, and medial-lateral translation were all increased. Moreover, the stress distribution on patellar prostheses was altered, resulting in an increased surface maximal equivalent stress on the corresponding area. Moreover, during the gait cycle, we found that the area with maximal equivalent stress shifted its position. Finally, the patellofemoral joint showed decreased motion stability. From the view of kinematics and mechanics, this paper suggests that patella should be retained during TKA if it is possible. The present study presented approaches and technologies for evaluating kinematics and mechanical properties of total knee joint after TKA under gait loads. PMID:27057134

  9. Kinematics and Mechanical Properties of Knees following Patellar Replacing and Patellar Retaining Total Knee Arthroplasty.

    PubMed

    Huang, Rongying; Liu, Yanqiang; Zhu, Jun

    2015-01-01

    Knee injury is a common medical issue. A full understanding of the kinematics and mechanical properties of knees following total knee arthroplasty (TKA) repair utilizing patellar replacement (only the base of the patella is replaced) versus patellar retaining surgical techniques is still lacking. In the current paper, we investigated magnetic resonance (MR) imaging data from knees repaired by these two methods and evaluated total knee models created using imaging reconstruction technology that simulated gait conditions. Results revealed that patellar replacement had little influence on tibiofemoral kinematics, although the tibia-surface equivalent stress increased slightly. By contrast, patellar replacement had a significant influence on the patellofemoral joint; patellar internal rotation, external rotation, and medial-lateral translation were all increased. Moreover, the stress distribution on patellar prostheses was altered, resulting in an increased surface maximal equivalent stress on the corresponding area. Moreover, during the gait cycle, we found that the area with maximal equivalent stress shifted its position. Finally, the patellofemoral joint showed decreased motion stability. From the view of kinematics and mechanics, this paper suggests that patella should be retained during TKA if it is possible. The present study presented approaches and technologies for evaluating kinematics and mechanical properties of total knee joint after TKA under gait loads. PMID:27057134

  10. Walls and chains of planar Skyrmions

    SciTech Connect

    Harland, Derek; Ward, R. S.

    2008-02-15

    In planar (baby) Skyrme systems, there may be extended linear structures which resemble either domain walls or chains of skyrmions, depending on the choice of potential and boundary conditions. We show that systems with a single vacuum, for example, with potential V=1-{phi}{sub 3}, admit chain solutions, whereas walls are ruled out by the uniqueness of the vacuum. On the other hand, in double-vacuum systems such as V=(1/2)(1-{phi}{sub 3}{sup 2}), one has stable wall solutions, but there are no stable chains; the walls may be viewed as the primary objects in such systems, with skyrmions being made out of them.

  11. Confinement and localization on domain walls

    NASA Astrophysics Data System (ADS)

    Auzzi, R.; Bolognesi, S.; Shifman, M.; Yung, A.

    2009-02-01

    We continue the studies of localization of the U(1) gauge fields on domain walls. Depending on dynamics of the bulk theory the gauge field localized on the domain wall can be either in the Coulomb phase or squeezed into flux tubes implying (Abelian) confinement of probe charges on the wall along the wall surface. First, we consider a simple toy model with one flavor in the bulk at weak coupling (a minimal model) realizing the latter scenario. We then suggest a model presenting an extension of the Seiberg-Witten theory which is at strong coupling, but all theoretical constructions are under full control if we base our analysis on a dual effective action. Finally, we compare our findings with the wall in a “nonminimal” theory with two distinct quark flavors that had been studied previously. In this case the U(1) gauge field trapped on the wall is exactly massless because it is the Goldstone boson of a U(1) symmetry in the bulk spontaneously broken on the wall. The theory on the wall is in the Coulomb phase. We explain why the mechanism of confinement discussed in the first part of the paper does not work in this case, and strings are not formed on the walls.

  12. New flow depth relationships for embankment dam stepped spillway design

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A common deficiency for embankment dams changing from a low hazard to a high hazard dam is inadequate spillway capacity. Roller compacted concrete (RCC) stepped spillways are a popular method to address this issue. Stepped spillway research has gained momentum in recent years due to the need for d...

  13. Successful strategies for retaining and recruiting imaging specialists: a two-year perspective.

    PubMed

    Bova, J B

    1993-01-01

    Strategies for retaining and recruiting of imaging personnel must focus on job enrichment through personal and professional growth opportunities; support and recognition for continuing education activities that promote those goals; and compensation and benefit programs that are commensurate with increased expectations and responsibilities. In this article, the author describes the process used to develop and successfully implement a comprehensive, integrated strategic plan, whose central focus is a multi-modality career path. Also discussed are the benefits realized over the past two years in the Department of Diagnostic Radiology and Nuclear Medicine at Rush-Presbyterian-St. Luke's Medical Center in Chicago. PMID:10126670

  14. Incentives for retaining and motivating health workers in Pacific and Asian countries

    PubMed Central

    Henderson, Lyn N; Tulloch, Jim

    2008-01-01

    This paper was initiated by the Australian Agency for International Development (AusAID) after identifying the need for an in-depth synthesis and analysis of available literature and information on incentives for retaining health workers in the Asia-Pacific region. The objectives of this paper are to: 1. Highlight the situation of health workers in Pacific and Asian countries to gain a better understanding of the contributing factors to health worker motivation, dissatisfaction and migration. 2. Examine the regional and global evidence on initiatives to retain a competent and motivated health workforce, especially in rural and remote areas. 3. Suggest ways to address the shortages of health workers in Pacific and Asian countries by using incentives. The review draws on literature and information gathered through a targeted search of websites and databases. Additional reports were gathered through AusAID country offices, UN agencies, and non-government organizations. The severe shortage of health workers in Pacific and Asian countries is a critical issue that must be addressed through policy, planning and implementation of innovative strategies – such as incentives – for retaining and motivating health workers. While economic factors play a significant role in the decisions of workers to remain in the health sector, evidence demonstrates that they are not the only factors. Research findings from the Asia-Pacific region indicate that salaries and benefits, together with working conditions, supervision and management, and education and training opportunities are important. The literature highlights the importance of packaging financial and non-financial incentives. Each country facing shortages of health workers needs to identify the underlying reasons for the shortages, determine what motivates health workers to remain in the health sector, and evaluate the incentives required for maintaining a competent and motivated health workforce. Decision-making factors and

  15. Incentives for retaining and motivating health workers in Pacific and Asian countries.

    PubMed

    Henderson, Lyn N; Tulloch, Jim

    2008-01-01

    This paper was initiated by the Australian Agency for International Development (AusAID) after identifying the need for an in-depth synthesis and analysis of available literature and information on incentives for retaining health workers in the Asia-Pacific region. The objectives of this paper are to: 1. Highlight the situation of health workers in Pacific and Asian countries to gain a better understanding of the contributing factors to health worker motivation, dissatisfaction and migration. 2. Examine the regional and global evidence on initiatives to retain a competent and motivated health workforce, especially in rural and remote areas. 3. Suggest ways to address the shortages of health workers in Pacific and Asian countries by using incentives. The review draws on literature and information gathered through a targeted search of websites and databases. Additional reports were gathered through AusAID country offices, UN agencies, and non-government organizations. The severe shortage of health workers in Pacific and Asian countries is a critical issue that must be addressed through policy, planning and implementation of innovative strategies--such as incentives--for retaining and motivating health workers. While economic factors play a significant role in the decisions of workers to remain in the health sector, evidence demonstrates that they are not the only factors. Research findings from the Asia-Pacific region indicate that salaries and benefits, together with working conditions, supervision and management, and education and training opportunities are important. The literature highlights the importance of packaging financial and non-financial incentives. Each country facing shortages of health workers needs to identify the underlying reasons for the shortages, determine what motivates health workers to remain in the health sector, and evaluate the incentives required for maintaining a competent and motivated health workforce. Decision-making factors and

  16. Management of a malpositioned implant using custom abutment and screw-retained fixed dental prosthesis.

    PubMed

    Turkyilmaz, Ilser

    2014-01-01

    A 32-year-old woman with missing permanent mandibular right molars and left first molar presented for treatment. One of the implants were misaligned during the placement due to sudden mouth closure of the patient. All implants success fully osseointegrated. However, the misaligned implant resulted in substantial mechanical and esthetic restorative challenges. The prosthodontic treatment included a custom abutment and a screw-retained fixed dental prosthesis on the right side. The patient did not report any problems with the implants and restorations during the first year of service. The treatment presented in this clinical report may be an alternative option to restore malpositioned implants. PMID:25307826

  17. Transmural penetration of sigmoid colon and rectum by retained surgical sponge after hysterectomy.

    PubMed

    Shin, Woo Young; Im, Chan Hyuk; Choi, Sun Keun; Choe, Yun-Mee; Kim, Kyung Rae

    2016-03-14

    Gossypiboma is a surgical sponge that is retained in the body after the operation. A 39-year-old female presented with vague lower abdominal pain, fever, and rectal discharge 15 mo after hysterectomy. The sponge remaining in the abdomen had no radiopaque marker. Therefore a series of radiographic evaluations was fruitless. The surgical sponge was found in the rectosigmoid colon on colonoscopy. The sponge penetrated the sigmoid colon and rectum transmurally, forming an opening on both sides. The patient underwent low anterior resection and was discharged without postoperative complications. PMID:26973401

  18. Transmural penetration of sigmoid colon and rectum by retained surgical sponge after hysterectomy

    PubMed Central

    Shin, Woo Young; Im, Chan Hyuk; Choi, Sun Keun; Choe, Yun-Mee; Kim, Kyung Rae

    2016-01-01

    Gossypiboma is a surgical sponge that is retained in the body after the operation. A 39-year-old female presented with vague lower abdominal pain, fever, and rectal discharge 15 mo after hysterectomy. The sponge remaining in the abdomen had no radiopaque marker. Therefore a series of radiographic evaluations was fruitless. The surgical sponge was found in the rectosigmoid colon on colonoscopy. The sponge penetrated the sigmoid colon and rectum transmurally, forming an opening on both sides. The patient underwent low anterior resection and was discharged without postoperative complications. PMID:26973401

  19. Bioinspired superhydrophobic carbonaceous hairy microstructures with strong water adhesion and high gas retaining capability.

    PubMed

    Zhao, Yun; Qin, Minglei; Wang, Anjie; Kim, Dongpyo

    2013-09-01

    Various hydrophobic hairy carbonaceous fibers are obtained by a low-temperature CVD process on catalyst-patterned surface patches which are selectively coated with silica to make the surface superhydrophobic and yet allow strong water adhesion for the "Salvinia effect". The versatility of the functional hairy fiber surfaces is demonstrated with a liquid barrier grid for cell microarray, a gas retaining capability under water/liquid for a membrane-free microfluidic chemical process, and functionalized papillae for cell immobilization with green algae. PMID:23813481

  20. [Experience with surgical-orthodontic management of impacted and retained upper canines].

    PubMed

    Herényi, G

    1990-07-01

    On basis of experiences obtained in the course of the surgical orthodontic treatment of 26 upper impacted and retained, respectively, incisors it has been established that, at given conditions, positioning the incisor into occlusion should be tried, even if the axis position approaches 90 degrees. The lesion is discovered relatively lately, many do not risk the treatment and the number of interrupted treatments is high as well. There is possibility to avoid possible complications, interruption of joining to force system, loss of anchorage, pulpa necrosis, root resorption, cysta follicularis. PMID:2390994

  1. Challenges and Opportunities in Recruiting and Retaining Underrepresented Populations Into Health Promotion Research

    PubMed Central

    Warren-Findlow, Jan; Prohaska, Thomas R.; Freedman, David

    2012-01-01

    Purpose To evaluate how recruitment strategies and program characteristics interact with participant characteristics to influence recruitment and retention in an exercise intervention study targeted to African American and White older adults with multiple chronic illnesses. Design and Methods Characteristics of 273 referrals and 103 enrollees were analyzed in conjunction with programmatic decisions about recruitment design and eligibility criteria. Results Eligible participants who did not enroll were younger and more likely to be under 60 and to self-report having diabetes. After 1 year, 70% of the enrolled participants remained in the program. Program attrition was not associated with randomization, race, or chronic illness but was associated with functional status, having a high school degree, and program site. Implications Program design decisions can significantly influence the participation of underrepresented populations in exercise health promotion programs for older adults. In particular, group-specific efforts targeted to recruiting and retaining African Americans can be successful. PMID:12637688

  2. Artificial Climbing Wall Design and Use.

    ERIC Educational Resources Information Center

    Cinnamon, Jerry

    Climbing walls can be designed to satisfy the needs of both untrained and experienced climbers offering these people a place to learn their craft as well as a place for them to keep their skills honed during off seasons. Users of the artificial wall can be classified into special groups, such as "Youth at Risk," who are engaged in challenge/growth…

  3. Steel shear walls, behavior, modeling and design

    SciTech Connect

    Astaneh-Asl, Abolhassan

    2008-07-08

    In recent years steel shear walls have become one of the more efficient lateral load resisting systems in tall buildings. The basic steel shear wall system consists of a steel plate welded to boundary steel columns and boundary steel beams. In some cases the boundary columns have been concrete-filled steel tubes. Seismic behavior of steel shear wall systems during actual earthquakes and based on laboratory cyclic tests indicates that the systems are quite ductile and can be designed in an economical way to have sufficient stiffness, strength, ductility and energy dissipation capacity to resist seismic effects of strong earthquakes. This paper, after summarizing the past research, presents the results of two tests of an innovative steel shear wall system where the boundary elements are concrete-filled tubes. Then, a review of currently available analytical models of steel shear walls is provided with a discussion of capabilities and limitations of each model. We have observed that the tension only 'strip model', forming the basis of the current AISC seismic design provisions for steel shear walls, is not capable of predicting the behavior of steel shear walls with length-to-thickness ratio less than about 600 which is the range most common in buildings. The main reasons for such shortcomings of the AISC seismic design provisions for steel shear walls is that it ignores the compression field in the shear walls, which can be significant in typical shear walls. The AISC method also is not capable of incorporating stresses in the shear wall due to overturning moments. A more rational seismic design procedure for design of shear walls proposed in 2000 by the author is summarized in the paper. The design method, based on procedures used for design of steel plate girders, takes into account both tension and compression stress fields and is applicable to all values of length-to-thickness ratios of steel shear walls. The method is also capable of including the effect of

  4. External Insulation of Masonry Walls and Wood Framed Walls

    SciTech Connect

    Baker, P.

    2013-01-01

    The use of exterior insulation on a building is an accepted and effective means to increase the overall thermal resistance of the assembly that also has other advantages of improved water management and often increased air tightness of building assemblies. For thin layers of insulation (1" to 1 1/2"), the cladding can typically be attached directly through the insulation back to the structure. For thicker insulation layers, furring strips have been added as a cladding attachment location. This approach has been used in the past on numerous Building America test homes and communities (both new and retrofit applications), and has been proven to be an effective and durable means to provide cladding attachment. However, the lack of engineering data has been a problem for many designers, contractors, and code officials. This research project developed baseline engineering analysis to support the installation of thick layers of exterior insulation on existing masonry and frame walls. Furthermore, water management details necessary to integrate windows, doors, decks, balconies and roofs were created to provide guidance on the integration of exterior insulation strategies with other enclosure elements.

  5. External Insulation of Masonry Walls and Wood Framed Walls

    SciTech Connect

    Baker, P.

    2013-01-01

    The use of exterior insulation on a building is an accepted and effective means to increase the overall thermal resistance of the assembly that also has other advantages of improved water management and often increased air tightness of building assemblies. For thin layers of insulation (1” to 1 ½”), the cladding can typically be attached directly through the insulation back to the structure. For thicker insulation layers, furring strips have been added as a cladding attachment location. This approach has been used in the past on numerous Building America test homes and communities (both new and retrofit applications), and has been proven to be an effective and durable means to provide cladding attachment. However, the lack of engineering data has been a problem for many designers, contractors, and code officials. This research project developed baseline engineering analysis to support the installation of thick layers of exterior insulation on existing masonry and frame walls. Furthermore, water management details necessary to integrate windows, doors, decks, balconies and roofs were created to provide guidance on the integration of exterior insulation strategies with other enclosure elements.

  6. A behavior model for blood donors and marketing strategies to retain and attract them

    PubMed Central

    Aldamiz-echevarria, Covadonga; Aguirre-Garcia, Maria Soledad

    2014-01-01

    Objective analyze and propose a theoretical model that describes blood donor decisions to help staff working in blood banks (nurses and others) in their efforts to capture and retain donors. Methods analysis of several studies on the motivations to give blood in Spain over the last six years, as well as past literature on the topic, the authors' experiences in the last 25 years in over 15 Non Governmental Organizations with different levels of responsibilities, their experiences as blood donors and the informal interviews developed during those 25 years. Results a model is proposed with different internal and external factors that influence blood donation, as well as the different stages of the decision-making process. Conclusion the knowledge of the donation process permits the development of marketing strategies that help to increase donors and donations. PMID:25029059

  7. Recruiting and retaining family caregivers to a randomized controlled trial on mindfulness-based stress reduction.

    PubMed

    Whitebird, Robin R; Kreitzer, Mary Jo; Lewis, Beth A; Hanson, Leah R; Crain, A Lauren; Enstad, Chris J; Mehta, Adele

    2011-09-01

    Caregivers for a family member with dementia experience chronic long-term stress that may benefit from new complementary therapies such as mindfulness-based stress reduction. Little is known however, about the challenges of recruiting and retaining family caregivers to research on mind-body based complementary therapies. Our pilot study is the first of its kind to successfully recruit caregivers for a family member with dementia to a randomized controlled pilot study of mindfulness-based stress reduction. The study used an array of recruitment strategies and techniques that were tailored to fit the unique features of our recruitment sources and employed retention strategies that placed high value on establishing early and ongoing communication with potential participants. Innovative recruitment methods including conducting outreach to health plan members and generating press coverage were combined with standard methods of community outreach and paid advertising. We were successful in exceeding our recruitment goal and retained 92% of the study participants at post-intervention (2 months) and 90% at 6 months. Recruitment and retention for family caregiver interventions employing mind-body based complementary therapies can be successful despite many challenges. Barriers include cultural perceptions about the use and benefit of complementary therapies, cultural differences with how the role of family caregiver is perceived, the use of group-based designs requiring significant time commitment by participants, and travel and respite care needs for busy family caregivers. PMID:21601010

  8. The role of the Azores Archipelago in capturing and retaining incoming particles

    NASA Astrophysics Data System (ADS)

    Sala, Iria; Harrison, Cheryl S.; Caldeira, Rui M. A.

    2016-02-01

    The capacity of the Azores Archipelago to capture and retain incoming particles and organisms that are drifting with the oceanic currents was the main focus of this study. Using the Hybrid Coordinate Ocean Model coupled with the Connectivity Modeling System (an offline Lagrangian tool) a series of experiments were conducted to determine: i) the origin of the particles that reach the archipelago, ii) the capacity of each island sub-group to retain incoming particles and organisms, as well as the iii) oceanographic phenomena that lead to their transport and retention. The Gulf Stream (GS) and the westward propagating eddy corridors were identified as the main transport pathways affecting the Azores region. Eddy Kinetic Energy from altimetry data and Lyapunov exponent analysis suggest that eddies and filaments are the main delivery mechanisms. In the upper mixed layer, the GS and its associated eddies are a predominant regional oceanographic feature injecting particles from the north and west boundaries toward the Azores. The capacity to capture particles of each island sub-group was directly proportional to their size, while the retention time within the Azores region increased with depth, associated with the decrease in velocity of the intermediate water currents. This study opens new prospects to understand transport in the Mid-Atlantic (Azores) region and the islands' role in marine colonization, dispersal, fisheries recruitment and speciation.

  9. Spin bearing retainer design optimization

    NASA Technical Reports Server (NTRS)

    Boesiger, Edward A.; Warner, Mark H.

    1991-01-01

    The dynamics behavior of spin bearings for momentum wheels (control-moment gyroscope, reaction wheel assembly) is critical to satellite stability and life. Repeated bearing retainer instabilities hasten lubricant deterioration and can lead to premature bearing failure and/or unacceptable vibration. These instabilities are typically distinguished by increases in torque, temperature, audible noise, and vibration induced by increases into the bearing cartridge. Ball retainer design can be optimized to minimize these occurrences. A retainer was designed using a previously successful smaller retainer as an example. Analytical methods were then employed to predict its behavior and optimize its configuration.

  10. Imaging Beads-Retained Prey Assay for Rapid and Quantitative Protein-Protein Interaction

    PubMed Central

    Zhou, Yan; Hong, Wanjin; Lu, Lei

    2013-01-01

    Conventional Western blot based pull-down methods involve lengthy and laborious work and the results are generally not quantitative. Here, we report the imaging beads-retained prey (IBRP) assay that is rapid and quantitative in studying protein-protein interactions. In this assay, the bait is immobilized onto beads and the prey is fused with a fluorescence protein. The assay takes advantage of the fluorescence of prey and directly quantifies the amount of prey binding to the immobilized bait under a microscope. We validated the assay using previously well studied interactions and found that the amount of prey retained on beads could have a relative linear relationship to both the inputs of bait and prey. IBRP assay provides a universal, fast, quantitative and economical method to study protein interactions and it could be developed to a medium- or high-throughput compatible method. With the availability of fluorescence tagged whole genome ORFs in several organisms, we predict IBRP assay should have wide applications. PMID:23555762

  11. European project RETAIN: new approach for IBC in teleradiology and PACS based on full ATM network

    NASA Astrophysics Data System (ADS)

    Cordonnier, Emmanuel; Jensch, Peter F.; Piqueras, Joachim; Gandon, Yves

    1995-05-01

    This paper describes the RETAIN project (radiological examination transfer on ATM Integrated Network), which is supported by the European Community, in the frame of the TEN-IBC program (trans-European networks integrated broad band communication). It links together three European sites in France (Rennes), Spain (Barcelona), and Germany (Oldenburg) and involves a partnership between the public national operators France Telecom, Telefonica, and Telekom. One important reason to explicitly consider asynchronous transfer mode (ATM) for medical imaging is that multimedia applications on such networks allow integration of digital data and person-to-person communication. The RETAIN project includes trials of teleworking sessions between radiologists of Rennes and Barcelona within a clinical and/or scientific context based on ATM equipments performing DICOM transfer on examination, digital remote manipulation within a comprehensive dialogue, and high quality visiophony on ATM adaptation layer (AAL) type 1. The project includes also visiophony trials with Oldenburg and preparation of harmonized regional experimentation within an emergency context. The network used is a full 10 Mbits/s ATM network directly connected to local PACSs.

  12. Photoelastic analysis to compare implant-retained and conventional obturator dentures

    NASA Astrophysics Data System (ADS)

    Goiato, Marcelo Coelho; Prado Ribeiro, Paula do; Pellizzer, Eduardo Piza; Pesqueira, Aldiéris Alves; Haddad, Marcela Filiè; dos Santos, Daniela Micheline; Moreno, Amália

    2012-06-01

    The use of photoelastic analysis contributes to the rehabilitation of patients with oral-sinus-nasal sequelae, which in turn affect important functions such as chewing, swallowing, and speech. The prosthetic rehabilitation with implant-retained dentures is a suitable treatment option. The purpose of this study was to verify, by using a photoelastic analysis, the stress distribution in implant-retained palatal obturator dentures (relined or not) associated with different attachment systems (O-ring, bar-clip, and bar-clip associated with distally placed O-rings). Two photoelastic models were obtained from an experimental maxillary cast presenting an oral-nasal communication. One model had two 13-mm length implants placed on the left region. A total of eight colorless maxillary obturators were fabricated and subsequently four of them were relined with soft silicone soft, and three had attachment systems associated. The assembly (model/attachment system/prosthesis) was positioned in a circular polariscope and a 100-N load was applied at 10 mm/s. The results showed that the denture relining influenced the distribution and amount of stress on the models. The O-ring group displayed the lowest stress levels, followed by bar-clip system associated with distally placed O-rings and bar-clip groups.

  13. A comparison between screw- and cement-retained implant prostheses. A literature review.

    PubMed

    Shadid, Rola; Sadaqa, Nasrin

    2012-06-01

    Implant-supported restorations can be secured to implants with screws (screw-retained), or they can be cemented to abutments which are attached to implants with screws (cement-retained). This literature review discusses the advantages and disadvantages of each method of retention from different aspects. These aspects include: ease of fabrication and cost, esthetics, access, occlusion, retention, incidence of loss of retention, retrievability, clinical prosthesis fit, restriction of implant position, effect on peri-implant tissue health, provisionalization, immediate loading, impression procedures, porcelain fracture, and clinical performance. Peer-reviewed literature published in the English language between 1955 and 2010 was reviewed using PubMed and hand searches. Since the choice of using either method of retention is still controversial, this review article offers some clinical situations that prefer one method of retention over the other. The review demonstrated that each method of retention has certain advantages and disadvantages; however, there are some clinical situations in which it is better to select one method of retention rather than the other. PMID:21091343

  14. Dynamic modeling and response of soil-wall systems

    SciTech Connect

    Veletsos, A.S.; Younan, A.H.

    1993-10-01

    The study reported herein is the third in a series of investigations motivated by need to gain improved understanding of the responses to earthquakes of deeply embedded and underground tanks storing radioactive wastes, and to develop rational but simple methods of analysis and design for such systems. Following a brief review of the errors that may result from the use of a popular model for evaluating the dynamic soil forces induced in a base-excited rigid wall retaining an elastic stratum, the sources of the errors are identified and a modification is proposed which defines correctly the action of the system. In the proposed modification, the stratum is modeled by a series of elastically supported, semi-infinite horizontal bars with distributed mass instead of massless springs. The concepts involved are introduced by reference to a system composed of a fixed-based wall and a homogeneous elastic stratum, and are then applied to the analysis of more complex soil-wall systems. Both harmonic and transient excitations are considered, and comprehensive numerical solutions are presented which elucidate the actions involved and the effects and relative importance of the relevant parameters.

  15. Living on the Edge of Stagnant Water: An Assessment of Environmental Impacts of Construction-Phase Drainage Congestion Along Dhaka City Flood Control Embankment, Bangladesh

    NASA Astrophysics Data System (ADS)

    Rasid, Harun; Mallsk, Azim U.

    1996-01-01

    Environmental impacts of the construction-phase drainage congestion along the Dhaka City Flood Control Embankment were assessed by a pilot questionnaire survey (in 1991) among the target population adjacent to the embankment. The results of the survey indicated that, despite significant alleviation of river flooding, the majority of the respondents experienced a new type of flood problem in the form of stagnant water inside the embankment, immediately following its construction. Not only had this stagnant water flooded and damaged their property, it had exposed them to a number of other environmental problems, such as accumulation of municipal sewage, foul odors, mosquitoes, and growth of water hyacinth. The study found that the respondents’ assessments of these environmental problems differed significantly according to the magnitude of the impact of stagnant water upon two subgroups within the target population. A postsurvey follow-up in 1994 indicated that this problem of drainage congestion had largely been alleviated by completing the construction of a number of drainage regulators. The study concludes by stressing the importance of synchronizing the construction of drainage structures with that of the embankment systems and by underlining policy implications for flood-vulnerable land use adjacent to embankments.

  16. Comparison of stress distribution between complete denture and implant-retained overdenture-2D FEA.

    PubMed

    Assunção, W G; Tabata, L F; Barão, V A R; Rocha, E P

    2008-10-01

    The aim of this study was to compare the stress distribution induced by posterior functional loads on conventional complete dentures and implant-retained overdentures with different attachment systems using a two-dimentional Finite Element Analysis (FEA-2D). Three models representative of edentulous mandible were constructed on AutoCAD software; Group A (control), a model of edentulous mandible supporting a complete denture; Group B, a model of edentulous mandible supporting an overdenture over two splinted implants connected with the bar-clip system; Group C, a model of edentulous mandible supporting an overdenture over two unsplinted implants with the O-ring system. Evaluation was conducted on Ansys software, with a vertical force of 100 N applied on the mandibular left first molar. When the stress was evaluated in supporting tissues, groups B (51.0 MPa) and C (52.6 MPa) demonstrated higher stress values than group A (10.1 MPa). Within the limits of this study, it may be concluded that the use of an attachment system increased stress values; furthermore, the use of splinted implants associated with the bar-clip attachment system favoured a lower stress distribution over the supporting tissue than the unsplinted implants with an O-ring abutment to retain the mandibular overdenture. PMID:18482352

  17. Electromagnetic approaches to wall characterization, wall mitigation, and antenna design for through-the-wall radar systems

    NASA Astrophysics Data System (ADS)

    Thajudeen, Christopher

    Through-the-wall imaging (TWI) is a topic of current interest due to its wide range of public safety, law enforcement, and defense applications. Among the various available technologies such as, acoustic, thermal, and optical imaging, which can be employed to sense and image targets of interest, electromagnetic (EM) imaging, in the microwave frequency bands, is the most widely utilized technology and has been at the forefront of research in recent years. The primary objectives for any Through-the-Wall Radar Imaging (TWRI) system are to obtain a layout of the building and/or inner rooms, detect if there are targets of interest including humans or weapons, determine if there are countermeasures being employed to further obscure the contents of a building or room of interest, and finally to classify the detected targets. Unlike conventional radar scenarios, the presence of walls, made of common construction materials such as brick, drywall, plywood, cinder block, and solid concrete, adversely affects the ability of any conventional imaging technique to properly image targets enclosed within building structures as the propagation through the wall can induce shadowing effects on targets of interest which may result in image degradation, errors in target localization, and even complete target masking. For many applications of TWR systems, the wall ringing signals are strong enough to mask the returns from targets not located a sufficient distance behind the wall, beyond the distance of the wall ringing, and thus without proper wall mitigation, target detection becomes extremely difficult. The results presented in this thesis focus on the development of wall parameter estimation, and intra-wall and wall-type characterization techniques for use in both the time and frequency domains as well as analysis of these techniques under various real world scenarios such as reduced system bandwidth scenarios, various wall backing scenarios, the case of inhomogeneous walls, presence

  18. 5. 'Stones for Wing Walls, Tunnel Walls, BeltCourse and Coping,' ...

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

    5. 'Stones for Wing Walls, Tunnel Walls, Belt-Course and Coping,' Southern Pacific Standard Plan Tunnels, ca. 1909. - Central Pacific Transcontinental Railroad, Sacramento to Nevada state line, Sacramento, Sacramento County, CA

  19. Characterization of the Carbon and Retained Austenite Distributions in Martensitic Medium Carbon, Low Alloy, Steel

    SciTech Connect

    Sherman, D. H.; Cross, Steven M; Kim, Sangho; Grandjean, F.; Long, G. J.; Miller, Michael K

    2007-01-01

    The retained austenite content and carbon distribution in martensite were determined as a function of cooling rate and temper temperature in steel that contained 1.31 at. pct C, 3.2 at. pct Si, and 3.2 at. pct non-iron metallic elements. Mossbauer spectroscopy, transmission electron microscopy (TEM), transmission synchrotron X-ray diffraction (XRD), and atom probe tomography were used for the microstructural analyses. The retained austenite content was an inverse, linear function of cooling rate between 25 and 560 K/s. The elevated Si content of 3.2 at. pct did not shift the start of austenite decomposition to higher tempering temperatures relative to SAE 4130 steel. The minimum tempering temperature for complete austenite decomposition was significantly higher (>650 C) than for SAE 4130 steel ({approx}300 C). The tempering temperatures for the precipitation of transition carbides and cementite were significantly higher (>400 C) than for carbon steels (100 C to 200 C and 200 C to 350 C), respectively. Approximately 90 pct of the carbon atoms were trapped in Cottrell atmospheres in the vicinity of the dislocation cores in dislocation tangles in the martensite matrix after cooling at 560 K/s and aging at 22 C. The 3.2 at. pct Si content increased the upper temperature limit for stable carbon clusters to above 215 C. Significant autotempering occurred during cooling at 25 K/s. The proportion of total carbon that segregated to the interlath austenite films decreased from 34 to 8 pct as the cooling rate increased from 25 to 560 K/s. Developing a model for the transfer of carbon from martensite to austenite during quenching should provide a means for calculating the retained austenite. The maximum carbon content in the austenite films was 6 to 7 at. pct, both in specimens cooled at 560 K/s and at 25 K/s. Approximately 6 to 7 at. pct carbon was sufficient to arrest the transformation of austenite to martensite. The chemical potential of carbon is the same in martensite

  20. Characterization of the Carbon and Retained Austenite Distributions in Martensitic Medium Carbon, High Silicon Steel

    NASA Astrophysics Data System (ADS)

    Sherman, Donald H.; Cross, Steven M.; Kim, Sangho; Grandjean, Fernande; Long, Gary J.; Miller, Michael K.

    2007-08-01

    The retained austenite content and carbon distribution in martensite were determined as a function of cooling rate and temper temperature in steel that contained 1.31 at. pct C, 3.2 at. pct Si, and 3.2 at. pct noniron metallic elements. Mössbauer spectroscopy, transmission electron microscopy (TEM), transmission synchrotron X-ray diffraction (XRD), and atom probe tomography were used for the microstructural analyses. The retained austenite content was an inverse, linear function of cooling rate between 25 and 560 K/s. The elevated Si content of 3.2 at. pct did not shift the start of austenite decomposition to higher tempering temperatures relative to SAE 4130 steel. The minimum tempering temperature for complete austenite decomposition was significantly higher (>650 °C) than for SAE 4130 steel (˜300 °C). The tempering temperatures for the precipitation of transition carbides and cementite were significantly higher (>400 °C) than for carbon steels (100 °C to 200 °C and 200 °C to 350 °C), respectively. Approximately 90 pct of the carbon atoms were trapped in Cottrell atmospheres in the vicinity of the dislocation cores in dislocation tangles in the martensite matrix after cooling at 560 K/s and aging at 22 °C. The 3.2 at. pct Si content increased the upper temperature limit for stable carbon clusters to above 215 °C. Significant autotempering occurred during cooling at 25 K/s. The proportion of total carbon that segregated to the interlath austenite films decreased from 34 to 8 pct as the cooling rate increased from 25 to 560 K/s. Developing a model for the transfer of carbon from martensite to austenite during quenching should provide a means for calculating the retained austenite. The maximum carbon content in the austenite films was 6 to 7 at. pct, both in specimens cooled at 560 K/s and at 25 K/s. Approximately 6 to 7 at. pct carbon was sufficient to arrest the transformation of austenite to martensite. The chemical potential of carbon is the same in

  1. Adsorption of quinolone antibiotics in spherical mesoporous silica: Effects of the retained template and its alkyl chain length.

    PubMed

    Liang, Zhijie; Zhaob, Zhiwei; Sun, Tianyi; Shi, Wenxin; Cui, Fuyi

    2016-03-15

    In this study, mesoporous silica (meso-silica) MCM-41 and those with the templates retained were synthesized and characterized. Adsorption capacities of the synthesized materials towards typical quinolone antibiotic pollutants, enrofloxacin and norfloxacin as representative, were investigated, and effects of the alkyl chain length of the templates on the adsorption capacity were evaluated. The results of this study indicated that the retained templates enhanced the adsorption capacities (Qmax) of the meso-silica MCM-41 toward hydrophobic enrofloxacin, but had an inhibitory effect on that towards hydrophilic norfloxacin, which were attributed to the hydrophobic inter-environment created by the long alkyl chains of the retained templates. Importantly, the adsorption capacity increased with the increase of the alkyl chain length of the retained templates. PMID:26642441

  2. Differences in articular track area of posterior-stabilized and cruciate-retaining retrieved total knee implants.

    PubMed

    Bradley, Michael P; Mayor, Michael B; Collier, John P

    2004-12-01

    Press-fit condylar total knee arthroplasties removed at revision surgery from 27 knees were examined. Fourteen of the implants were posterior-stabilized press-fit condylar systems and 13 were cruciate-retaining press-fit condylar systems. The articular track areas were examined using a digital camera and manual measurements. Findings revealed the track area in posterior-stabilized implants (93%) was larger than in cruciate-retaining implants (59%). Mean posterior distance ratio of the articular track from the posterior limit of the polyethylene was 2% (.08 cm) for posterior-stabilized implants versus 23% (.97 cm) for cruciate-retaining implants. No differences in wear rating were noted. The pattern of articular contact in cruciate-retaining knees demonstrated little migration of the femoral contact surface across the tibial polyethylene plateau. PMID:15633958

  3. Development and pathologies of the arterial wall.

    PubMed

    Seidelmann, Sara B; Lighthouse, Janet K; Greif, Daniel M

    2014-06-01

    Arteries consist of an inner single layer of endothelial cells surrounded by layers of smooth muscle and an outer adventitia. The majority of vascular developmental studies focus on the construction of endothelial networks through the process of angiogenesis. Although many devastating vascular diseases involve abnormalities in components of the smooth muscle and adventitia (i.e., the vascular wall), the morphogenesis of these layers has received relatively less attention. Here, we briefly review key elements underlying endothelial layer formation and then focus on vascular wall development, specifically on smooth muscle cell origins and differentiation, patterning of the vascular wall, and the role of extracellular matrix and adventitial progenitor cells. Finally, we discuss select human diseases characterized by marked vascular wall abnormalities. We propose that continuing to apply approaches from developmental biology to the study of vascular disease will stimulate important advancements in elucidating disease mechanism and devising novel therapeutic strategies. PMID:24071897

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

    NASA Astrophysics Data System (ADS)

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

    2001-12-01

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

  5. Epithelial Label-Retaining Cells Are Absent during Tooth Cycling in Salmo salar and Polypterus senegalus.

    PubMed

    Vandenplas, Sam; Willems, Maxime; Witten, P Eckhard; Hansen, Tom; Fjelldal, Per Gunnar; Huysseune, Ann

    2016-01-01

    The Atlantic salmon (Salmo salar) and African bichir (Polypterus senegalus) are both actinopterygian fish species that continuously replace their teeth without the involvement of a successional dental lamina. Instead, they share the presence of a middle dental epithelium: an epithelial tier enclosed by inner and outer dental epithelium. It has been hypothesized that this tier could functionally substitute for a successional dental lamina and might be a potential niche to house epithelial stem cells involved in tooth cycling. Therefore, in this study we performed a BrdU pulse chase experiment on both species to (1) determine the localization and extent of proliferating cells in the dental epithelial layers, (2) describe cell dynamics and (3) investigate if label-retaining cells are present, suggestive for the putative presence of stem cells. Cells proliferate in the middle dental epithelium, outer dental epithelium and cervical loop at the lingual side of the dental organ to form a new tooth germ. Using long chase times, both in S. salar (eight weeks) and P. senegalus (eight weeks and twelve weeks), we could not reveal the presence of label-retaining cells in the dental organ. Immunostaining of P. senegalus dental organs for the transcription factor Sox2, often used as a stem cell marker, labelled cells in the zone of outer dental epithelium which grades into the oral epithelium (ODE transition zone) and the inner dental epithelium of a successor only. The location of Sox2 distribution does not provide evidence for epithelial stem cells in the dental organ and, more specifically, in the middle dental epithelium. Comparison of S. salar and P. senegalus reveals shared traits in tooth cycling and thus advances our understanding of the developmental mechanism that ensures lifelong replacement. PMID:27049953

  6. Epithelial Label-Retaining Cells Are Absent during Tooth Cycling in Salmo salar and Polypterus senegalus

    PubMed Central

    Vandenplas, Sam; Willems, Maxime; Witten, P. Eckhard; Hansen, Tom; Fjelldal, Per Gunnar; Huysseune, Ann

    2016-01-01

    The Atlantic salmon (Salmo salar) and African bichir (Polypterus senegalus) are both actinopterygian fish species that continuously replace their teeth without the involvement of a successional dental lamina. Instead, they share the presence of a middle dental epithelium: an epithelial tier enclosed by inner and outer dental epithelium. It has been hypothesized that this tier could functionally substitute for a successional dental lamina and might be a potential niche to house epithelial stem cells involved in tooth cycling. Therefore, in this study we performed a BrdU pulse chase experiment on both species to (1) determine the localization and extent of proliferating cells in the dental epithelial layers, (2) describe cell dynamics and (3) investigate if label-retaining cells are present, suggestive for the putative presence of stem cells. Cells proliferate in the middle dental epithelium, outer dental epithelium and cervical loop at the lingual side of the dental organ to form a new tooth germ. Using long chase times, both in S. salar (eight weeks) and P. senegalus (eight weeks and twelve weeks), we could not reveal the presence of label-retaining cells in the dental organ. Immunostaining of P. senegalus dental organs for the transcription factor Sox2, often used as a stem cell marker, labelled cells in the zone of outer dental epithelium which grades into the oral epithelium (ODE transition zone) and the inner dental epithelium of a successor only. The location of Sox2 distribution does not provide evidence for epithelial stem cells in the dental organ and, more specifically, in the middle dental epithelium. Comparison of S. salar and P. senegalus reveals shared traits in tooth cycling and thus advances our understanding of the developmental mechanism that ensures lifelong replacement. PMID:27049953

  7. The Chilean Rural Practitioner Programme: a multidimensional strategy to attract and retain doctors in rural areas

    PubMed Central

    Peña, Sebastian; Ramirez, Jorge; Becerra, Carlos; Carabantes, Jorge

    2010-01-01

    Abstract Developing countries currently face internal and external migration of their health workforce and interventions are needed to attract and retain health professionals in rural areas. Evidence of multidimensional interventions, however, is scarce. This study explores a long-standing strategy to attract and retain doctors to rural areas in Chile: the Rural Practitioner Programme. The main objective is to describe the programme, characterize its multidimensional set of incentives and appraise preliminary programme outcomes. Retrospective national data were employed to examine recruitment, retention and incentives provided to extend the length of stay and motivate non-clinical work. The programme has successfully recruited a large number of applicants, with acceptance rates close to 100%. Retention rates are nearly 100% (drop-outs are exceptional), but only 58% of participants stay for the maximum period. Areas with greater work difficulty are attracting the best-ranked applicants, but incentives to engage in community projects, management responsibilities, continuous medical education and research have achieved mixed results. Rural doctors are satisfied with their experience and 70% plan to practise as specialists in a referral hospital. The programme has successfully matched the interests of physicians in specialization with the country’s need for rural doctors. However, a gap might be forming between the demand for certain specialties and what the programme can offer. There is a need to conciliate both parties, which will require a more refined strategy than before. This should be grounded in robust knowledge based on programme outcomes and evidence of the interests and motivations of health professionals. PMID:20461139

  8. In vitro determination of the mechanical and chemical properties of a fibre orthodontic retainer.

    PubMed

    Silvestrini-Biavati, Armando; Angiero, Francesca; Gibelli, Francesca; Signore, Antonio; Benedicenti, Stefano

    2012-12-01

    The aim of this study was to analyse, in vitro, the chemical and mechanical properties of a new fibre retainer, Everstick, comparing its characteristics with the requirements for an orthodontic retainer. Chemical analysis was used to examine seven fibre bundles exposed to a photocuring lamp and then to different acids and resistance to corrosion by artificial saliva fortified with plaque acids. The mechanical properties examined were tensile strength and resistance to flexural force. Ten fibre samples were tested for each mechanical analysis and the mean value and standard deviation were calculated. Wilcoxon signed rank test was used to evaluate change in weight after treatment in each group. To determine changes over time between the groups for each acid considered separately, both repeated measures analysis of variance (ANOVA) on original data and on rank transformed data were used. If the results were different, ANOVA on rank-transformed data was considered. Acetic acid was found to be the most corrosive and caused the most substance loss: both pure and at the salivary pH value. Hydrofluoric acid was the most damaging. For all acids analysed in both groups (lactic, formic, acetic, propionic), changes after treatment were statistically different between two groups (P < 0.001 for lactic, acetic, propionic; P = 0.004 for formic acid).The mean Young's modulus value was 68 510 MPa. Deformation before the fibre separated into its constituent elements (glass fibre and composite) was 3.9 per cent, stress to rupture was 1546 MPa, and resistance to bending was 534 MPa. The deflection produced over a length of 12 mm was 1.4 mm. The fibre bundle was attacked by acids potentially present in the oral cavity; the degree of aggressiveness depending on the acid concentration. To preserve fibre bundles long term, careful plaque control is necessary, especially in the interproximal spaces, to avoid acid formation. The tested product was found to be sufficiently strong to oppose

  9. The Chilean Rural Practitioner Programme: a multidimensional strategy to attract and retain doctors in rural areas.

    PubMed

    Peña, Sebastian; Ramirez, Jorge; Becerra, Carlos; Carabantes, Jorge; Arteaga, Oscar

    2010-05-01

    Developing countries currently face internal and external migration of their health workforce and interventions are needed to attract and retain health professionals in rural areas. Evidence of multidimensional interventions, however, is scarce. This study explores a long-standing strategy to attract and retain doctors to rural areas in Chile: the Rural Practitioner Programme. The main objective is to describe the programme, characterize its multidimensional set of incentives and appraise preliminary programme outcomes.Retrospective national data were employed to examine recruitment, retention and incentives provided to extend the length of stay and motivate non-clinical work. The programme has successfully recruited a large number of applicants, with acceptance rates close to 100%. Retention rates are nearly 100% (drop-outs are exceptional), but only 58% of participants stay for the maximum period. Areas with greater work difficulty are attracting the best-ranked applicants, but incentives to engage in community projects, management responsibilities, continuous medical education and research have achieved mixed results. Rural doctors are satisfied with their experience and 70% plan to practise as specialists in a referral hospital.The programme has successfully matched the interests of physicians in specialization with the country's need for rural doctors. However, a gap might be forming between the demand for certain specialties and what the programme can offer. There is a need to conciliate both parties, which will require a more refined strategy than before. This should be grounded in robust knowledge based on programme outcomes and evidence of the interests and motivations of health professionals. PMID:20461139

  10. The Glanville fritillary genome retains an ancient karyotype and reveals selective chromosomal fusions in Lepidoptera

    PubMed Central

    Ahola, Virpi; Lehtonen, Rainer; Somervuo, Panu; Salmela, Leena; Koskinen, Patrik; Rastas, Pasi; Välimäki, Niko; Paulin, Lars; Kvist, Jouni; Wahlberg, Niklas; Tanskanen, Jaakko; Hornett, Emily A.; Ferguson, Laura C.; Luo, Shiqi; Cao, Zijuan; de Jong, Maaike A.; Duplouy, Anne; Smolander, Olli-Pekka; Vogel, Heiko; McCoy, Rajiv C.; Qian, Kui; Chong, Wong Swee; Zhang, Qin; Ahmad, Freed; Haukka, Jani K.; Joshi, Aruj; Salojärvi, Jarkko; Wheat, Christopher W.; Grosse-Wilde, Ewald; Hughes, Daniel; Katainen, Riku; Pitkänen, Esa; Ylinen, Johannes; Waterhouse, Robert M.; Turunen, Mikko; Vähärautio, Anna; Ojanen, Sami P.; Schulman, Alan H.; Taipale, Minna; Lawson, Daniel; Ukkonen, Esko; Mäkinen, Veli; Goldsmith, Marian R.; Holm, Liisa; Auvinen, Petri; Frilander, Mikko J.; Hanski, Ilkka

    2014-01-01

    Previous studies have reported that chromosome synteny in Lepidoptera has been well conserved, yet the number of haploid chromosomes varies widely from 5 to 223. Here we report the genome (393 Mb) of the Glanville fritillary butterfly (Melitaea cinxia; Nymphalidae), a widely recognized model species in metapopulation biology and eco-evolutionary research, which has the putative ancestral karyotype of n=31. Using a phylogenetic analyses of Nymphalidae and of other Lepidoptera, combined with orthologue-level comparisons of chromosomes, we conclude that the ancestral lepidopteran karyotype has been n=31 for at least 140 My. We show that fusion chromosomes have retained the ancestral chromosome segments and very few rearrangements have occurred across the fusion sites. The same, shortest ancestral chromosomes have independently participated in fusion events in species with smaller karyotypes. The short chromosomes have higher rearrangement rate than long ones. These characteristics highlight distinctive features of the evolutionary dynamics of butterflies and moths. PMID:25189940

  11. Axions from cosmic string and wall decay

    SciTech Connect

    Hagmann, Chris

    2010-08-30

    If inflation occurred with a reheat temperature > T{sub PQ}, axions from the decay of global axion strings and domain walls would make an important contribution to the cosmological energy density, comparable to that from vacuum misalignment. Several groups have numerically studied the evolution of axion strings and walls in the past, however substantial uncertainties remain in their contribution to the present density {Omega}{sub a,string+wall{approx}}1-100(f{sub a}/10{sup 12} GeV){sup 7/6}, where f{sub a} is the axion decay constant. I will describe the numerical methods used in our simulations and show results for several string and wall configurations.

  12. Axions from cosmic string and wall decay

    SciTech Connect

    Hagmann, C A

    2010-03-10

    If inflation occurred with a reheat temperature > T{sub PQ}, axions from the decay of global axion strings and domain walls would make an important contribution to the cosmological energy density, comparable to that from vacuum misalignment. Several groups have numerically studied the evolution of axion strings and walls in the past, however substantial uncertainties remain in their contribution to the present density {Omega}{sub a,string+wall} {approx} 1-100 (f{sub a}/10{sup 12} GeV){sup 7/6}, where f{sub a} is the axion decay constant. I will describe the numerical methods used in our simulations and show results for several string and wall configurations.

  13. Shear wall experiments and design in Japan

    SciTech Connect

    Park, Y.J.; Hofmayer, C.

    1994-12-01

    This paper summarizes the results of recent survey studies on the available experimental data bases and design codes/standards for reinforced concrete (RC) shear wall structures in Japan. Information related to the seismic design of RC reactor buildings and containment structures was emphasized in the survey. The seismic requirements for concrete structures, particularly those related to shear strength design, are outlined. Detailed descriptions are presented on the development of Japanese shear wall equations, design requirements for containment structures, and ductility requirements.

  14. Evolution of string-wall networks and axionic domain wall problem

    SciTech Connect

    Hiramatsu, Takashi; Kawasaki, Masahiro; Saikawa, Ken'ichi E-mail: kawasaki@icrr.u-tokyo.ac.jp

    2011-08-01

    We study the cosmological evolution of domain walls bounded by strings which arise naturally in axion models. If we introduce a bias in the potential, walls become metastable and finally disappear. We perform two dimensional lattice simulations of domain wall networks and estimate the decay rate of domain walls. By using the numerical results, we give a constraint for the bias parameter and the Peccei-Quinn scale. We also discuss the possibility to probe axion models by direct detection of gravitational waves produced by domain walls.

  15. Assessment of Susceptibility to Liquefaction of Saturated Road Embankment Subjected to Dynamic Loads

    NASA Astrophysics Data System (ADS)

    Borowiec, Anna; Maciejewski, Krzysztof

    2014-03-01

    Liquefaction has always been intensely studied in parts of the world where earthquakes occur. However, the seismic activity is not the only possible cause of this phenomenon. It may in fact be triggered by some human activities, such as constructing and mining or by rail and road transport. In the paper a road embankment built across a shallow water reservoir is analyzed in terms of susceptibility to liquefaction. Two types of dynamic loadings are considered: first corresponding to an operation of a vibratory roller and second to an earthquake. In order to evaluate a susceptibility of soil to liquefaction, a factor of safety against triggering of liquefaction is used (FSTriggering). It is defined as a ratio of vertical effective stresses to the shear stresses both varying with time. For the structure considered both stresses are obtained using finite element method program, here Plaxis 2D. The plastic behavior of the cohesionless soils is modeled by means of Hardening Soil (HS) constitutive relationship, implemented in Plaxis software. As the stress tensor varies with time during dynamic excitation, the FSTriggering has to be calculated for some particular moment of time when liquefaction is most likely to occur. For the purposes of this paper it is named a critical time and established for reference point at which the pore pressures were traced in time. As a result a factor of safety distribution throughout embankment is generated. For the modeled structure, cyclic point loads (i.e., vibrating roller) present higher risk than earthquake of magnitude 5.4. Explanation why considered structure is less susceptible to earthquake than typical dam could lay in stabilizing and damping influence of water, acting here on both sides of the slope. Analogical procedure is applied to assess liquefaction susceptibility of the road embankment considered but under earthquake excitation. Only the higher water table is considered as it is the most unfavorable. Additionally the

  16. Prevalence of cysts and tumors around the retained and unerupted third molars in the Indian population

    PubMed Central

    Patil, Santosh; Halgatti, Vishal; Khandelwal, Suneet; Santosh, B.S.; Maheshwari, Sneha

    2014-01-01

    Aim Tooth impaction is a frequent phenomena and surgical removal of these teeth are the commonest of the dental surgical procedures. The debate over the removal of asymptomatic impacted third molars still continues. The aim of this retrospective study was to determine the incidence of development of cysts and tumors around the retained and unerupted third molars in the Indian population. Material and methods 5486 impacted third molars of 4133 patients were studied through the panoramic radiographs for the presence of associated cysts and tumors. The ages of the patients ranged from 17 to 67 years, with a mean of 33.7 years. The results were evaluated using the Pearson chi-square test. P-values less than 0.05 were considered to be statistically significant. Results There were 134 cysts (2.24%) and 63 tumors (1.16%) found that were associated with impacted third molars, of which 3 were malignant (0.05%). 143 patients had symptoms such as swelling or pain due to cystic or neoplastic lesions. The remainder 54 patients had no symptoms suggestive of pathology. The most common cyst was dentigerous cyst and the most common tumor was ameloblastoma. Conclusion The results indicate that cysts and tumors do develop in a relatively small but still considerable minority of patients. The fact that a considerable number of patients had no signs or symptoms indicating pathology is certainly worth considering. Consultation should be sought from dental specialists if there are symptoms in the third molar region. PMID:25737923

  17. LCF on turbogenerator rotors and coil retaining rings: material characterization and sensitivity analyses

    NASA Astrophysics Data System (ADS)

    Olmi, G.; Freddi, A.

    2010-06-01

    Turbogenerator rotors and coil retaining rings (CRRs) are highly loaded components typically subjected to LCF at any machine switch-on and switch-off. The present study aims at LCF characterization of two widely applied steels, 26 NiCrMoV 14 5 (for rotor manufacturing) and 18Mn18Cr (for CRR). Material anisotropy is also considered by performing an extended experimental campaign on specimens machined along different (tangential and radial) directions from trial components. The experimental tests, carried out with the use of a novel testing-constraining device for misalignment auto-compensation and with an original methodology for strain controlling, led to the determination of static, cyclic and fatigue curves for all the investigated cases. The research was completed by sensitivity analyses on the adopted models, thus determining fatigue curve tolerance bands, and by a statistical Analysis of Variance to compare the LCF performance of the different materials along the two considered machining directions. Results showed a significantly better performance of 18Mn18Cr and a weak anisotropy effect, remarkable just at the highest strain values, on a reduced portion of the LCF life range.

  18. 4-D imaging of seepage in earthen embankments with time-lapse inversion of self-potential data constrained by acoustic emissions localization

    NASA Astrophysics Data System (ADS)

    Rittgers, J. B.; Revil, A.; Planes, T.; Mooney, M. A.; Koelewijn, A. R.

    2015-02-01

    New methods are required to combine the information contained in the passive electrical and seismic signals to detect, localize and monitor hydromechanical disturbances in porous media. We propose a field experiment showing how passive seismic and electrical data can be combined together to detect a preferential flow path associated with internal erosion in a Earth dam. Continuous passive seismic and electrical (self-potential) monitoring data were recorded during a 7-d full-scale levee (earthen embankment) failure test, conducted in Booneschans, Netherlands in 2012. Spatially coherent acoustic emissions events and the development of a self-potential anomaly, associated with induced concentrated seepage and internal erosion phenomena, were identified and imaged near the downstream toe of the embankment, in an area that subsequently developed a series of concentrated water flows and sand boils, and where liquefaction of the embankment toe eventually developed. We present a new 4-D grid-search algorithm for acoustic emissions localization in both time and space, and the application of the localization results to add spatially varying constraints to time-lapse 3-D modelling of self-potential data in the terms of source current localization. Seismic signal localization results are utilized to build a set of time-invariant yet spatially varying model weights used for the inversion of the self-potential data. Results from the combination of these two passive techniques show results that are more consistent in terms of focused ground water flow with respect to visual observation on the embankment. This approach to geophysical monitoring of earthen embankments provides an improved approach for early detection and imaging of the development of embankment defects associated with concentrated seepage and internal erosion phenomena. The same approach can be used to detect various types of hydromechanical disturbances at larger scales.

  19. Secondary cell walls: biosynthesis and manipulation.

    PubMed

    Kumar, Manoj; Campbell, Liam; Turner, Simon

    2016-01-01

    Secondary cell walls (SCWs) are produced by specialized plant cell types, and are particularly important in those cells providing mechanical support or involved in water transport. As the main constituent of plant biomass, secondary cell walls are central to attempts to generate second-generation biofuels. Partly as a consequence of this renewed economic importance, excellent progress has been made in understanding how cell wall components are synthesized. SCWs are largely composed of three main polymers: cellulose, hemicellulose, and lignin. In this review, we will attempt to highlight the most recent progress in understanding the biosynthetic pathways for secondary cell wall components, how these pathways are regulated, and how this knowledge may be exploited to improve cell wall properties that facilitate breakdown without compromising plant growth and productivity. While knowledge of individual components in the pathway has improved dramatically, how they function together to make the final polymers and how these individual polymers are incorporated into the wall remain less well understood. PMID:26663392

  20. Residual interference and wind tunnel wall adaption

    NASA Technical Reports Server (NTRS)

    Mokry, Miroslav

    1989-01-01

    Measured flow variables near the test section boundaries, used to guide adjustments of the walls in adaptive wind tunnels, can also be used to quantify the residual interference. Because of a finite number of wall control devices (jacks, plenum compartments), the finite test section length, and the approximation character of adaptation algorithms, the unconfined flow conditions are not expected to be precisely attained even in the fully adapted stage. The procedures for the evaluation of residual wall interference are essentially the same as those used for assessing the correction in conventional, non-adaptive wind tunnels. Depending upon the number of flow variables utilized, one can speak of one- or two-variable methods; in two dimensions also of Schwarz- or Cauchy-type methods. The one-variable methods use the measured static pressure and normal velocity at the test section boundary, but do not require any model representation. This is clearly of an advantage for adaptive wall test section, which are often relatively small with respect to the test model, and for the variety of complex flows commonly encountered in wind tunnel testing. For test sections with flexible walls the normal component of velocity is given by the shape of the wall, adjusted for the displacement effect of its boundary layer. For ventilated test section walls it has to be measured by the Calspan pipes, laser Doppler velocimetry, or other appropriate techniques. The interface discontinuity method, also described, is a genuine residual interference assessment technique. It is specific to adaptive wall wind tunnels, where the computation results for the fictitious flow in the exterior of the test section are provided.

  1. 14. INTERIOR VIEW OF FIREPLACE AND SURROUNDING WALL IN FIRST ...

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

    14. INTERIOR VIEW OF FIREPLACE AND SURROUNDING WALL IN FIRST FLOOR, NORTHWEST PARLOR, NORTH WALL, WITH SCALE (NOTE WALL STENCILING) - George W. Eckhart House, 810 Main Street, Wheeling, Ohio County, WV

  2. Reduced concentrations of apolipoproteins B-100 and A-I in serum from cows with retained placenta.

    PubMed Central

    Oikawa, S; Katoh, N

    1997-01-01

    The purpose of the present study was to evaluate apolipoprotein B-100 and A-I concentrations in cows with retained placenta. Animals used were cows with retained placenta alone (n = 10), those with both retained placenta and ketosis (n = 7), and controls (n = 10). Apolipoprotein B-100 concentrations at 2 to 4 d after parturition were significantly (P < 0.01) decreased in cows with retained placenta alone (mean +/- SD, 0.084 +/- 0.029 mg/ML of serum) when compared with those in control cows (0.154 +/- 0.022 mg/mL). Apolipoprotein A-I concentrations (0.713 +/- 0.177 mg/ML) were also significantly (P < 0.05) lower than those of controls (0.895 +/- 0.159 mg/mL). These decreases were more distinct for apolipoproteins B-100 (55% of controls) than A-I concentrations (80% of controls). Concentrations of apolipoprotein B-100 (0.071 +/- 0.032 mg/mL; P < 0.01) and A-I (0.708 +/- 0.189 mg/mL; P < 0.05) in the cows with both retained placenta and ketosis were also reduced, when compared with values in controls. Other than apolipoproteins, cows with retained placenta alone had significantly (P < 0.01) higher serum nonesterified fatty acids, and lower triglyceride concentrations. Significantly (P < 0.01) higher nonesterified fatty acids and lower triglyceride concentrations were similarly observed in cows with both retained placenta and ketosis. PMID:9342458

  3. Fluvial landscapes - human societies interactions during the last 2000 years: the Middle Loire River and its embanking since the Middle Ages (France)

    NASA Astrophysics Data System (ADS)

    Castanet, Cyril; Carcaud, Nathalie

    2015-04-01

    This research deals with the study of fluvial landscapes, heavily and precociously transformed by societies (fluvial anthroposystems). It aims to characterize i), fluvial responses to climate, environmental and anthropogenic changes ii), history of hydraulical constructions relative to rivers iii), history of fluvial origin risks and their management - (Program: AGES Ancient Geomorphological EvolutionS of the Loire River hydrosystem). The Middle Loire River valley in the Val d'Orléans was strongly and precociously occupied, particularly during historical periods. Hydrosedimentary flows are there irregular. The river dykes were built during the Middle Ages (dykes named turcies) and the Modern Period, but ages and localizations of the oldest dykes were not precisely known. A systemic and multi-scaled approach aimed to characterize i), palaeo-hydrographical, -hydrological and -hydraulical evolutions of the Loire River, fluvial risks (palaeo-hazards and -vulnerabilities) and their management. It is based on an integrated approach, in and out archaeological sites: morpho-stratigraphy, sedimentology, geophysics, geochemistry, geomatics, geochronology, archaeology. Spatio-temporal variability of fluvial hazards is characterized. A model of the Loire River fluvial activity is developed: multicentennial scale variability, with higher fluvial activity episodes during the Gallo-Roman period, IX-XIth centuries and LIA. Fluvial patterns changes are indentified. Settlement dynamics and hydraulical constructions of the valley are specified. We establish the ages and localizations of the oldest discovered dikes of the Middle Loire River: after the Late Antiquity and before the end of the Early Middle Ages (2 dated dykes), between Bou and Orléans cities. During historical periods, we suggest 2 main thresholds concerning socio-environmental interactions: the first one during the Early Middle Ages (turcies: small scattered dykes), the second during the Modern Period (levees: high

  4. Consumption of unsafe food in the adjacent area of Hazaribag tannery campus and Buriganga River embankments of Bangladesh: heavy metal contamination.

    PubMed

    Islam, G M Rabiul; Khan, Faysal Elahi; Hoque, Md Mozammel; Jolly, Yeasmin Nahar

    2014-11-01

    The concentrations of Cr, Cd, Pb, Hg, and As in water, poultry meat, fish, vegetables, and rice plants obtained from the area adjacent to the Hazaribag tannery campus, Dhaka, Bangladesh, were estimated and compared with permissible levels established by the WHO and FAO and levels reported previously by other authors. The metal contents were in the following order according to the concentration in contaminated irrigation water: Cr > Pb > As > Hg > Cd. Mean concentrations of Cr, Pb, Hg, and As in irrigated water were above the permissible levels, whereas the results were below the permissible levels for Cd. The metal concentrations in poultry meat, fish, rice, and vegetables were in the following orders: Pb > Cr > Cd > Hg > As, Pb > Cr > Cd > As > Hg, Pb > As, and Cr > Pb > Cd > As > Hg, respectively. The mean concentrations of metals in poultry meat, fish, rice, and vegetables were much higher than the permissible levels. The trends of weekly intake of heavy metals (WIMs) from poultry meat, fish, rice, and vegetables were as follows: Pb > Cr > Cd > Hg > As, Pb > Cr > Cd > As > Hg, Pb > As, and Cr > Pb > Cd > As > Hg, respectively. WIMs for all the metals were lower than the provisional maximum weekly intake recommended by WHO/FAO and USNAS. PMID:25030244

  5. Crystal Melting and Wall Crossing Phenomena

    NASA Astrophysics Data System (ADS)

    Yamazaki, Masahito

    This paper summarizes recent developments in the theory of Bogomol'nyi-Prasad-Sommerfield (BPS) state counting and the wall crossing phenomena, emphasizing in particular the role of the statistical mechanical model of crystal melting. This paper is divided into two parts, which are closely related to each other. In the first part, we discuss the statistical mechanical model of crystal melting counting BPS states. Each of the BPS states contributing to the BPS index is in one-to-one correspondence with a configuration of a molten crystal, and the statistical partition function of the melting crystal gives the BPS partition function. We also show that smooth geometry of the Calabi-Yau manifold emerges in the thermodynamic limit of the crystal. This suggests a remarkable interpretation that an atom in the crystal is a discretization of the classical geometry, giving an important clue as such to the geometry at the Planck scale. In the second part, we discuss the wall crossing phenomena. Wall crossing phenomena states that the BPS index depends on the value of the moduli of the Calabi-Yau manifold, and jumps along real codimension one subspaces in the moduli space. We show that by using type IIA/M-theory duality, we can provide a simple and an intuitive derivation of the wall crossing phenomena, furthermore clarifying the connection with the topological string theory. This derivation is consistent with another derivation from the wall crossing formula, motivated by multicentered BPS extremal black holes. We also explain the representation of the wall crossing phenomena in terms of crystal melting, and the generalization of the counting problem and the wall crossing to the open BPS invariants.

  6. Crystal Melting and Wall Crossing Phenomena

    NASA Astrophysics Data System (ADS)

    Yamazaki, Masahito

    2010-02-01

    This paper summarizes recent developments in the theory of Bogomol'nyi-Prasad-Sommerfield (BPS) state counting and the wall crossing phenomena, emphasizing in particular the role of the statistical mechanical model of crystal melting. This paper is divided into two parts, which are closely related to each other. In the first part, we discuss the statistical mechanical model of crystal melting counting BPS states. Each of the BPS state contributing to the BPS index is in one-to-one correspondence with a configuration of a molten crystal, and the statistical partition function of the melting crystal gives the BPS partition function. We also show that smooth geometry of the Calabi-Yau manifold emerges in the thermodynamic limit of the crystal. This suggests a remarkable interpretation that an atom in the crystal is a discretization of the classical geometry, giving an important clue as to the geometry at the Planck scale.In the second part we discuss the wall crossing phenomena. Wall crossing phenomena states that the BPS index depends on the value of the moduli of the Calabi-Yau manifold, and jumps along real codimension one subspaces in the moduli space. We show that by using type IIA/M-theory duality, we can provide a simple and an intuitive derivation of the wall crossing phenomena, furthermore clarifying the connection with the topological string theory. This derivation is consistent with another derivation from the wall crossing formula, motivated by multi-centered BPS extremal black holes. We also explain the representation of the wall crossing phenomena in terms of crystal melting, and the generalization of the counting problem and the wall crossing to the open BPS invariants.

  7. Combined Visualization of Wall Thickness and Wall Shear Stress for the Evaluation of Aneurysms.

    PubMed

    Glaßer, Sylvia; Lawonn, Kai; Hoffmann, Thomas; Skalej, Martin; Preim, Bernhard

    2014-12-01

    For an individual rupture risk assessment of aneurysms, the aneurysm's wall morphology and hemodynamics provide valuable information. Hemodynamic information is usually extracted via computational fluid dynamic (CFD) simulation on a previously extracted 3D aneurysm surface mesh or directly measured with 4D phase-contrast magnetic resonance imaging. In contrast, a noninvasive imaging technique that depicts the aneurysm wall in vivo is still not available. Our approach comprises an experiment, where intravascular ultrasound (IVUS) is employed to probe a dissected saccular aneurysm phantom, which we modeled from a porcine kidney artery. Then, we extracted a 3D surface mesh to gain the vessel wall thickness and hemodynamic information from a CFD simulation. Building on this, we developed a framework that depicts the inner and outer aneurysm wall with dedicated information about local thickness via distance ribbons. For both walls, a shading is adapted such that the inner wall as well as its distance to the outer wall is always perceivable. The exploration of the wall is further improved by combining it with hemodynamic information from the CFD simulation. Hence, the visual analysis comprises a brushing and linking concept for individual highlighting of pathologic areas. Also, a surface clustering is integrated to provide an automatic division of different aneurysm parts combined with a risk score depending on wall thickness and hemodynamic information. In general, our approach can be employed for vessel visualization purposes where an inner and outer wall has to be adequately represented. PMID:26356964

  8. Saline pulse test monitoring with the self-potential method to nonintrusively determine the velocity of the pore water in leaking areas of earth dams and embankments

    NASA Astrophysics Data System (ADS)

    Ikard, S. J.; Revil, A.; Jardani, A.; Woodruff, W. F.; Parekh, M.; Mooney, M.

    2012-04-01

    A method is proposed to localize preferential fluid flow pathways in porous media on the basis of time-lapse self-potential measurements associated with salt tracer injection upstream. This method is first tested using laboratory data. A network of nonpolarizing electrodes located is connected to a highly sensitive voltmeter used to record the resulting electrical field fluctuations occurring over time at the surface of the tank. The transport of the conductive salt plume through the permeable porous materials changes the localized streaming potential coupling coefficient associated with the advective drag of the excess charge of the pore water and is also responsible for a diffusion current associated with the salinity gradient. Monitoring of the electrical potential distribution at the ground surface can be used to localize the pulse of saline water over time and to determine its velocity. This method applies in real time and can be used to track highly localized flow pathways characterized by high permeability. Our sandbox experiment demonstrates the applicability of this new method under well-controlled conditions with a coarse-sand channel embedded between fine-sand banks. A finite element model allows us to reproduce the time-lapse electrical potential distribution over the channel, but some discrepancies were observed on the banks. Finally, we performed a numerical simulation for a synthetic case study inspired by a recently published field case study. A Markov chain Monte Carlo sampler is used to determine the permeability and the porosity of the preferential fluid flow pathway of this synthetic case study.

  9. Wall shear stress manifolds and near wall flow topology in aneurysms

    NASA Astrophysics Data System (ADS)

    Arzani, Amirhossein; Gambaruto, Alberto M.; Chen, Guoning; Shadden, Shawn C.

    2015-11-01

    Transport of atherogenic and thrombogenic chemicals near the vessel wall highly influences atherosclerosis and thrombosis. The high Schmidt number of these species leads to a thin concentration boundary layer near the wall. The wall shear stress (WSS) vector field can be scaled to obtain the near wall velocity in this region, thus providing first order approximation to near wall transport. In this study, the complex blood flow in patient-specific abdominal aortic aneurysms was considered. Lagrangian tracking of surface-bound tracers representing near wall species was employed to identify Lagrangian coherent structures (LCS) for the WSS surface vector field. The WSS LCS matched the stable and unstable manifolds of saddle type fixed points of the time-average WSS vector field, due to the quasi-steady nature of these near wall transport processes. A WSS exposure time measure is introduced to quantify the concentration of near wall species. The effect of diffusion and normal flow on these structures is investigated. The WSS LCS highly influence the concentration of near wall species, and provide a template for near-wall transport.

  10. Cell Wall Remodeling Enzymes Modulate Fungal Cell Wall Elasticity and Osmotic Stress Resistance

    PubMed Central

    Ene, Iuliana V.; Walker, Louise A.; Schiavone, Marion; Lee, Keunsook K.; Martin-Yken, Hélène; Dague, Etienne; Gow, Neil A. R.; Munro, Carol A.

    2015-01-01

    ABSTRACT The fungal cell wall confers cell morphology and protection against environmental insults. For fungal pathogens, the cell wall is a key immunological modulator and an ideal therapeutic target. Yeast cell walls possess an inner matrix of interlinked β-glucan and chitin that is thought to provide tensile strength and rigidity. Yeast cells remodel their walls over time in response to environmental change, a process controlled by evolutionarily conserved stress (Hog1) and cell integrity (Mkc1, Cek1) signaling pathways. These mitogen-activated protein kinase (MAPK) pathways modulate cell wall gene expression, leading to the construction of a new, modified cell wall. We show that the cell wall is not rigid but elastic, displaying rapid structural realignments that impact survival following osmotic shock. Lactate-grown Candida albicans cells are more resistant to hyperosmotic shock than glucose-grown cells. We show that this elevated resistance is not dependent on Hog1 or Mkc1 signaling and that most cell death occurs within 10 min of osmotic shock. Sudden decreases in cell volume drive rapid increases in cell wall thickness. The elevated stress resistance of lactate-grown cells correlates with reduced cell wall elasticity, reflected in slower changes in cell volume following hyperosmotic shock. The cell wall elasticity of lactate-grown cells is increased by a triple mutation that inactivates the Crh family of cell wall cross-linking enzymes, leading to increased sensitivity to hyperosmotic shock. Overexpressing Crh family members in glucose-grown cells reduces cell wall elasticity, providing partial protection against hyperosmotic shock. These changes correlate with structural realignment of the cell wall and with the ability of cells to withstand osmotic shock. PMID:26220968

  11. Potential use of lateritic and marine clay soils as landfill liners to retain heavy metals.

    PubMed

    Chalermyanont, Tanit; Arrykul, Surapon; Charoenthaisong, Nanthanit

    2009-01-01

    The potential of a lateritic soil and a marine clay, typical of those found in hot and humid climatic regions, was assessed for use as a landfill liner material. A series of tests were conducted - physical and chemical, batch adsorption, column, hydraulic conductivity, etc., - to evaluate the heavy metal sorption capacity, chemical compatibility of hydraulic conductivity, and transport parameters of the soils. Experimental results showed that the marine clay had better adsorption capacity than that of the lateritic soil and that its hydraulic conductivity was an order of magnitude lower. In addition, the hydraulic conductivities of both soils when permeated with low concentration heavy metal solutions were below 1x10(-7)cm/s. When permeated with Cr, Pb, Cd, Zn, and Ni solutions, the retardation factors of the lateritic soil and the marine clay ranged from 10 to 98 and 37 to 165, respectively, while the diffusion coefficients ranged from 1.0x10(-5) to 7.5x10(-6) and 3.0 to 9.14x10(-7)cm2/s, respectively. For both soils, Cr and Pb were retained relatively well, while Cd, Zn, and Ni were more mobile. The marine clay had higher retardation factors and lower diffusion coefficients, and its hydraulic conductivity was more compatible with Cr solution, than that of the lateritic soil. In general, the properties of the marine clay indicate that it has significant advantages over the lateritic soil as landfill liner material. PMID:18550353

  12. Assessment of Retained Austenite in AISI D2 Tool Steel Using Magnetic Hysteresis and Barkhausen Noise Parameters

    NASA Astrophysics Data System (ADS)

    Kahrobaee, Saeed; Kashefi, Mehrdad

    2015-03-01

    Inaccurate heat treatment process could result in excessive amount of retained austenite, which degrades the mechanical properties, like strength, wear resistance, and hardness of cold work tool steel parts. Thus, to control the mechanical properties, quantitative measurement of the retained austenite is a critical step in optimizing the heat-treating parameters. X-ray diffraction method is the most frequently used technique for this purpose. This technique is, however, destructive and time consuming. Furthermore, it is not applicable to 100% quality inspection of industrial parts. In the present paper, the influence of austenitizing temperature on the retained austenite content and hardness of AISI D2 tool steel has been studied. Additionally, nondestructive magnetic hysteresis parameters of the samples including coercivity, magnetic saturation, and maximum differential permeability as well as their magnetic Barkhausen noise features (RMS peak voltage and peak position) have been investigated. The results revealed direct relations between magnetic saturation, differential permeability, and MBN peak amplitude with increasing austenitizing temperature due to the retained austenite formation. Besides, both parameters of coercivity and peak position had an inverse correlation with the retained austenite fraction.

  13. Fluctuation of neutrophil counts around parturition in Holstein dairy cows with and without retained placenta.

    PubMed

    Moretti, Pierangelo; Probo, Monica; Cantoni, Andrea; Paltrinieri, Saverio; Giordano, Alessia

    2016-08-01

    Retained placenta (RP) is often diagnosed in high-yielding dairy cows and can negatively affect reproductive performances. The objective of the present study was to investigate the hematological and biochemical profile of cows with RP before and immediately after parturition, with particular emphasis on neutrophil counts, since a previous study demonstrated the presence of peripheral neutropenia in dairy cows with RP sampled a few days after parturition. Results from 12 Holstein cows affected by RP and from 17 clinically healthy controls sampled one week pre-partum, within 12h after calving and between 48 and 72h after parturition were compared between groups and over time. Compared with controls, cows with RP had lower lymphocyte counts before parturition, lower leukocyte and neutrophil counts at parturition, lower monocyte counts at all times, and higher β-hydroxybutyrate before and after parturition. Erythroid and biochemical parameters were similar over time in both groups, whereas RP cows did not show the increase of neutrophil counts that occurs in controls at parturition. Hence, the finding of a lower neutrophil count in a routinely hemogram performed at parturition could be used as an alarm signal suggesting to monitor the affected animals. Moreover, although the underlying pathogenetic mechanism should be better investigated, the present study describes for the first time the association between altered blood leukocyte concentrations at parturition in RP compared to control cows. PMID:27473997

  14. The Study of External Dose Rate and Retained Body Activity of Patients Receiving 131I Therapy for Differentiated Thyroid Carcinoma

    PubMed Central

    Zhang, Haiying; Jiao, Ling; Cui, Songye; Wang, Liang; Tan, Jian; Zhang, Guizhi; He, Yajing; Ruan, Shuzhou; Fan, Saijun; Zhang, Wenyi

    2014-01-01

    Radiation safety is an integral part of targeted radionuclide therapy. The aim of this work was to study the external dose rate and retained body activity as functions of time in differentiated thyroid carcinoma patients receiving 131I therapy. Seventy patients were stratified into two groups: the ablation group (A) and the follow-up group (FU). The patients’ external dose rate was measured, and simultaneously, their retained body radiation activity was monitored at various time points. The equations of the external dose rate and the retained body activity, described as a function of hours post administration, were fitted. Additionally, the release time for patients was calculated. The reduction in activity in the group receiving a second or subsequent treatment was more rapid than the group receiving only the initial treatment. Most important, an expeditious method was established to indirectly evaluate the retained body activity of patients by measuring the external dose rate with a portable radiation survey meter. By this method, the calculated external dose rate limits are 19.2, 8.85, 5.08 and 2.32 μSv·h−1 at 1, 1.5, 2 and 3 m, respectively, according to a patient’s released threshold level of retained body activity <400 MBq. This study is beneficial for radiation safety decision-making. PMID:25337944

  15. Thermally treated wine retains vasodilatory activity in rat and guinea pig aorta.

    PubMed

    Mudnić, Ivana; Budimir, Danijela; Jajić, Ivan; Boban, Nataša; Sutlović, Davorka; Jerončić, Ana; Boban, Mladen

    2011-06-01

    In contrast to the intact wine, cardiovascular effects of the thermally treated wine have not been studied, despite widespread habits of cooking with wine and consumption of mulled wine. Vasodilatory effects of the red wine heated at 75 and 125°C were examined in the isolated rat and guinea pig aorta and compared with the intact and wine dealcoholized without thermal stress. Samples were analyzed for their phenolic content, antioxidant capacity, resveratrol and ethanol contents. Heating-induced degradation of individual phenolic fraction was observed only in the samples treated at 125°C, although total phenolic concentration and related antioxidant activity increased in the thermally treated samples due to the reduction in their volume. All wine samples regardless of treatment caused similar maximal relaxation in both species, but the response was stronger in aortas from guinea pigs. At the lowest concentrations up to 1‰, dealcoholized wine produced vasodilation greater than that produced by intact wine and wines treated at 75 and 125°C, which showed similar vasodilating activity at all concentrations. Our results indicate that wine thermally treated under heating conditions applicable to the preparation of a mulled wine and cooking with wine largely retains vasodilatory activity in vitro despite significant heat-induced changes in its composition. PMID:21423027

  16. [The 'van der Linden' retainer].

    PubMed

    van der Linden, F P

    2003-11-01

    Normally, only the anterior teeth have to be retained after an orthodontic treatment. For that purpose, a lingually bonded wire is preferred in the mandible and a removable plate in the maxilla. The design of the Van der Linden-retainer is based on theoretical considerations and secures rigid fixation of the six anterior teeth with solid anchorage in that region. A retention plate should not be used to move anterior teeth. However, with instant corrections small improvements can be realized. The fabrication and clinical use of the Van der Linden-retainer is explained and illustrated. PMID:14669487

  17. Interactions between domain walls and spin currents

    NASA Astrophysics Data System (ADS)

    Klaui, M.; Laufenberg, M.; Backes, D.; Buhrer, W.; Rudiger, U.; Vila, L.; Vouille, C.; Faini, G.

    2006-03-01

    A promising novel approach for switching magnetic nanostructures is current-induced domain wall propagation (CIDP), where due to a spin torque effect, electrons transfer angular momentum to a head-to-head domain wall and thereby push it in the direction of the electron flow without any externally applied fields. This effect has been observed with a variety of techniques including MFM [1] and spin polarized scanning electron microscopy [2] to directly observe current-induced domain wall propagation in ferromagnetic nanostructures and magnetoresistance measurements to systematically probe the critical current densities as a function of the geometry [3]. The observed wall velocities and critical current densities, where wall motion sets in at room temperature, do not agree well with theoretical 0K calculations [4]. We have therefore measured the critical current densities as a function of the sample temperature. We find that the spin torque effect becomes more efficient at low temperatures, which could account for some of the observed discrepancies between the 300K experiment and the 0K simulation. [1] A. Yamaguchi et al., Phys. Rev. Lett. 92, 77205 (2004); [2] M. Klaui et al., PRL 95, 26601 (2005); [3] M. Klaui et al., PRL 94, 106601 (2005); [4] A. Thiaville et al., EPL 69, 990 (2005); G. Tatara et al., APL 86, 252509 (2005);

  18. Starch derivative-based superabsorbent with integration of water-retaining and controlled-release fertilizers.

    PubMed

    Zhong, Kang; Lin, Zuan-Tao; Zheng, Xi-Liang; Jiang, Gang-Biao; Fang, Yu-Sheng; Mao, Xiao-Yun; Liao, Zong-Wen

    2013-02-15

    Phosphate rock (PHR), a traditional fertilizer, is abundant, but is hard to be utilized by plants. To improve the utilization of PHR, and to integrate water-retaining and controlled-release fertilizers, an agricultural superabsorbent polymer based on sulfonated corn starch/poly (acrylic acid) embedding phosphate rock (SCS/PAA/PHR) was prepared. PHR can be suspended and well-dispersed in SCS/PAA by sulfonated corn starch (SCS). PHR and KOH were mixed in acrylic acid solution to provide phosphorus (P) and potassium (K) nutrients, respectively. Impacts on water absorption capacity of the superabsorbent were investigated. The maximum swelling capacity in distilled water or 0.9 wt.% (weight percent) NaCl solution reached 498 g g(-1) and 65 g g(-1) (water/prepared dry superabsorbent) respectively. Moreover, release behaviours of P and K in SCS/PAA/PHR were also investigated. The results showed that SCS/PAA/PHR possessed excellent sustained-release property of plant nutrient, and the SCS/PAA could improve the P release greatly. Besides, the XPS analysis was employed to study the relationship between PHR and superabsorbent polymer. PMID:23399166

  19. Wind tunnel analysis of the aerodynamic loads on rolling stock over railway embankments: the effect of shelter windbreaks.

    PubMed

    Avila-Sanchez, Sergio; Pindado, Santiago; Lopez-Garcia, Oscar; Sanz-Andres, Angel

    2014-01-01

    Wind-flow pattern over embankments involves an overexposure of the rolling stock travelling on them to wind loads. Windbreaks are a common solution for changing the flow characteristic in order to decrease unwanted effects induced by the presence of cross-wind. The shelter effectiveness of a set of windbreaks placed over a railway twin-track embankment is experimentally analysed. A set of two-dimensional wind tunnel tests are undertaken and results corresponding to pressure tap measurements over a section of a typical high-speed train are herein presented. The results indicate that even small-height windbreaks provide sheltering effects to the vehicles. Also, eaves located at the windbreak tips seem to improve their sheltering effect. PMID:25544954

  20. Wind Tunnel Analysis of the Aerodynamic Loads on Rolling Stock over Railway Embankments: The Effect of Shelter Windbreaks

    PubMed Central

    Avila-Sanchez, Sergio; Lopez-Garcia, Oscar; Sanz-Andres, Angel

    2014-01-01

    Wind-flow pattern over embankments involves an overexposure of the rolling stock travelling on them to wind loads. Windbreaks are a common solution for changing the flow characteristic in order to decrease unwanted effects induced by the presence of cross-wind. The shelter effectiveness of a set of windbreaks placed over a railway twin-track embankment is experimentally analysed. A set of two-dimensional wind tunnel tests are undertaken and results corresponding to pressure tap measurements over a section of a typical high-speed train are herein presented. The results indicate that even small-height windbreaks provide sheltering effects to the vehicles. Also, eaves located at the windbreak tips seem to improve their sheltering effect. PMID:25544954

  1. Effect of Retained Austenite on the Fracture Toughness of Quenching and Partitioning (Q&P)-Treated Sheet Steels

    NASA Astrophysics Data System (ADS)

    Wu, Riming; Li, Wei; Zhou, Shu; Zhong, Yong; Wang, Li; Jin, Xuejun

    2014-04-01

    Fracture toughness K IC was measured by double edge-notched tension (DENT) specimens with fatigue precracks on quenching and partitioning (Q&P)-treated high-strength (ultimate tensile strength [UTS] superior to 1200 MPa) sheet steels consisting of 4 to 10 vol pct of retained austenite. Crack extension force, G IC, evaluated from the measured K IC, is used to analyze the role of retained austenite in different fracture behavior. Meanwhile, G IC is deduced by a constructed model based on energy absorption by martensite transformation (MT) behavior of retained austenite in Q&P-treated steels. The tendency of the change of two results is in good agreement. The Q&P-treated steel, quenched at 573 K (300 °C), then partitioned at 573 K (300 °C), holding for 60 seconds, has a fracture toughness of 74.1 MPa·m1/2, which is 32 pct higher than quenching and tempering steel (55.9 MPa·m1/2), and 16 pct higher than quenching and austempering (QAT) steel (63.8 MPa·m1/2). MT is found to occur preferentially at the tips of extension cracks on less stable retained austenite, which further improves the toughness of Q&P steels; on the contrary, the MT that occurs at more stable retained austenite has a detrimental effect on toughness.

  2. DC-Electrical Resistivity Imaging for embankment dike investigation: A 3D extended normalisation approach

    NASA Astrophysics Data System (ADS)

    Fargier, Yannick; Lopes, Sérgio Palma; Fauchard, Cyrille; François, Daniel; Côte, Philippe

    2014-04-01

    Levee, dike and earth embankment dam structures are difficult to assess because of their length and complexity. Managers often include geophysical investigations in the overall dike condition assessment and the DC-Electrical Resistivity Imaging (ERI) method is particularly applicable owing to its cost-effectiveness and its potential sensitivity to internal erosion. However, due to the truly 3D nature of embankment dikes, implementing inline longitudinal tomographies along with conventional 2D inversion is likely to yield image artefacts. 3D effects from external causes (geometry, water reservoir) can be predicted and therefore we present a new approach based on redefining the normalisation principle to derive apparent resistivities from the measured data. The aim is to provide a set of pre-processed apparent resistivities that are not contaminated by external 3D effects and that yield more reliable results when processed within a 2D conventional inversion scheme. The presented approach is successfully applied to synthetic and real data sets, proving superior to the conventional 2D approach, although data acquisition approach is the same thus keeping the same cost-effectiveness.

  3. Conservative and timely treatment in retained products of conception: a case report of placenta accreta ritention

    PubMed Central

    Antonella, Guarino; Luisa, Di Benedetto; Chiara, Assorgi; Alessandra, Rocca; Caserta, Donatella

    2015-01-01

    The term retained products of conception (RPOC) refers to intrauterine tissue that develops after conception and persists after medical and surgical pregnancy termination, miscarriage, and vaginal or cesarean delivery. One of the most important factor risk for RPOC is placenta accreta, defined as “the abnormal adherence, either in whole or in part, of the afterbirth to the underlying uterine wall”. We report a case of a 37 years old woman referred to our gynecologic department with irregular vaginal bleeding. On her medical history, she had a cesarean occurred 3 months before. Ultrasonography revealed in the uterine cavity hyperechoic mass, treated with curettage. Two weeks later the curettage, patient complained still vaginal bleeding. On the transvaginal ultrasound, the uterine cavity was occupied again by a hyperechoic mass. She underwent to hysteroscopic resection and histological diagnosis was compatible with placenta accreta residual. In the follow up she had not complications. Early diagnosis, prompt evaluation of bleeding is important for timely treatment and for preventing immediate complications and demolitive approach. A careful follow up is necessary to prevent late consequences. The purpose of this study is to report our experience in timely diagnosis and conservative management. PMID:26722586

  4. Recruiting and Retaining Underrepresented Groups and Special Populations in Nursing Programs. Napa Valley College, October 1991-June 1992.

    ERIC Educational Resources Information Center

    Zylinski, Doris; Metson, Elena

    In 1991-92, Napa Valley College participated in a statewide project to develop and publish this guide for recruiting and retaining underrepresented groups and special populations in vocational nursing. Among the highlighted recommendations presented in the guide are the following: (1) disseminate information on nursing education and job…

  5. Training needs for general dentistry residents to place and restore two-implant-retained mandibular overdentures.

    PubMed

    Malmstrom, Hans; Xiao, Jin; Romanos, Georgios E; Ren, Yan-Fang

    2015-01-01

    Implant therapy is rapidly becoming a standard of care for replacing missing dentition. Predoctoral dental curricula include some training in the implant restorative phase but offer limited exposure to the surgical phase, so it is important for postdoctoral general dentistry residency programs to provide competency training in all phases of implant therapy. The aim of this study was to determine the training needed for general dentistry residents to achieve competence in this area, specifically by defining the number of clinical experiences necessary in both the surgical and prosthetic phases of implant-retained mandibular overdenture construction (IRMOD). Fifteen Advanced Education in General Dentistry (AEGD) residents at one academic dental institution placed two implants in a total of 50 patients with edentulous mandibles and subsequently restored them with IRMOD. The supervising faculty member and the residents evaluated the competency level on a five-point scale after each implant placement and prosthetic case completion. According to the faculty evaluations, the residents achieved surgical competence after placing two implants in four to six cases and prosthetic management competence after restoring two to four cases of IRMOD. All 50 patients were satisfied with the treatment outcomes of IRMOD. This study concluded that general dentistry residents could potentially achieve competence in both the surgical and prosthetic phases of implant therapy while enrolled in an AEGD program. PMID:25576555

  6. Lung-retained contaminants, urinary chromium and nickel among stainless steel welders.

    PubMed

    Kalliomäki, P L; Rahkonen, E; Vaaranen, V; Kalliomäki, K; Aittoniemi, K

    1981-01-01

    The magnetic method of measuring the amount of lung retained contaminants as well as urinary chromium and nickel determinations have been performed among 83 stainless steel (SS) welders who have used manual metal arc (MMA) and tungsten inert gas (TIG) welding techniques. The welders were divided into four groups according to the time percentage used for MMA welding. Only exposure to MMA/SS welding fumes resulted in clearly elevated chromium concentrations in the urine, the correlation coefficient between the values of urinary chromium and MMA/SS percentage being very significant (p less than 0.001). Among the smokers the urinary chromium values were increased (p less than 0.05) perhaps owing to contaminated cigarettes. In many workplaces the urinary chromium values of several welders exceeded the value of 30 microgram/l which is the recommended reference value in Finland. Owing to the solubility properties of nickel compounds in SS welding fumes urinary nickel concentrations were only slightly elevated among MMA/SS welders, and therefore, the urinary nickel determinations do not reflect the level of exposure to nickel compounds. The measured average remanent magnetic field of the chest area correlated well (p less than 0.01) with the use of the MMA technique. A very significant correlation (p less than 0.001) existed between the average remanent magnetic fields of the chest and the urinary chromium values of MMA/ss welders. PMID:7298215

  7. Recruiting, Preparing, and Retaining High Quality Secondary Mathematics and Science Teachers for Urban Schools: The Cal Teach Experimental Program

    ERIC Educational Resources Information Center

    Newton, Xiaoxia A.; Jang, Heeju; Nunes, Nicci; Stone, Elisa

    2010-01-01

    Recruiting, preparing, and retaining high quality secondary mathematics and science teachers are three of the most critical problems in the nation's urban schools that serve a vast majority of children from socially and economically disadvantaged backgrounds. Although the factors contributing to these problems are complex, one area that has caught…

  8. Domain walls and the creation of strings

    NASA Astrophysics Data System (ADS)

    Bergshoeff, Eric; Gran, Ulf; Linares, Román; Nielsen, Mikkel; Roest, Diederik

    2003-08-01

    The phenomenon of creation of strings, occurring when particles pass through a domain wall and related to the Hanany Witten effect via dualities, is discussed in ten and nine dimensions. We consider both the particle actions in massive backgrounds and the 1/4-supersymmetric particle string domain-wall supergravity solutions and discuss their physical interpretation. In 10D we discuss the D0 F1 D8 system in massive IIA theory while in 9D the SL(2, Bbb R)-generalization is constructed. It consists of (p, q)-particles, (r, s)-strings and the double domain-wall solution of the three different 9D gauged supergravities where a subgroup of SL(2, Bbb R) is gauged.

  9. Conservative management of retained cardiac missiles: case report and literature review.

    PubMed

    Lundy, Jonathan B; Johnson, Eric K; Seery, Jason M; Pham, Tach; Frizzi, James D; Chasen, Arthur B

    2009-01-01

    Intracardiac foreign bodies may be caused by direct penetrating trauma, embolization from injury to another area of the body, or iatrogenically from fragments of intravascular access devices. Penetrating cardiac trauma commonly presents with a hemodynamically unstable patient necessitating emergent life-saving procedures. Missile embolization to the heart can occur after injury to systemic and pulmonary veins. Central venous access devices may fracture after placement and embolize. Especially in the setting of penetrating cardiac trauma, these intracardiac foreign bodies require expeditious removal. Limited data exist regarding the conservative management of intracardiac material after trauma. We present the case of a 42-year-old male soldier injured in a mortar blast in Iraq who suffered multiple injuries to include a right hemopneumothorax and soft tissue injuries to the chest and both lower extremities that was found to have a 2-cm by 2-mm intracardiac metal fragment. Additional imaging revealed a metallic fragment localized to the interatrial septum. The patient suffered no adverse sequelae from nonoperative management. A review of the world literature regarding the subject of posttraumatic retained cardiac missiles (RCMs) is also included to help future surgeons in the management of this rare entity. PMID:19896630

  10. Surgical Removal of Retained Subfoveal Perfluorocarbon Liquid through a Therapeutic Macular Hole with Intravitreal PFCL Injection and Gas Tamponade

    PubMed Central

    Kim, Jae Min; Park, Kyu Hyung; Chung, Hum

    2013-01-01

    We report two cases of surgical removal of a retained subfoveal perfluorocarbon liquid (PFCL) bubble through a therapeutic macular hole combined with intravitreal PFCL injection and gas tamponade. Two patients underwent pars plana vitrectomy with PFCL injection for rhegmatogenous retinal detachment. In both cases, a retained subfoveal PFCL bubble was noticed postoperatively by funduscopy and optical coherence tomography. Both patients underwent surgical removal of the subfoveal PFCL through a therapeutic macular hole and gas tamponade. The therapeutic macular holes were completely closed by gas tamponade and the procedure yielded a good visual outcome (best-corrected visual acuity of 20 / 40 in both cases). In one case, additional intravitreal PFCL injection onto the macula reduced the size of the therapeutic macular hole and preserved the retinal structures in the macula. Surgical removal of a retained subfoveal PFCL bubble through a therapeutic macular hole combined with intravitreal PFCL injection and gas tamponade provides an effective treatment option. PMID:24082781

  11. Defect junctions and domain wall dynamics

    SciTech Connect

    Avelino, P.P.; Oliveira, J.C.R.E.; Martins, C.J.A.P.; Menezes, J.; Menezes, R.

    2006-06-15

    We study a number of domain wall forming models where various types of defect junctions can exist. These illustrate some of the mechanisms that will determine the evolution of defect networks with junctions. Understanding these mechanisms is vital for a proper assessment of a number of cosmological scenarios: we will focus on the issue of whether or not cosmological frustrated domain wall networks can exist at all, but our results are also relevant for the dynamics of cosmic (super)strings, where junctions are expected to be ubiquitous. We also define and discuss the properties that would make up the ideal model in terms of hypothetical frustrated wall networks, and provide an explicit construction for such a model. We carry out a number of numerical simulations of the evolution of these networks, analyze and contrast their results, and discuss their implications for our no-frustration conjecture.

  12. First wall and blanket design for a high wall loading compact tokamak power reactor

    SciTech Connect

    Sviatoslavsky, I.N.; Abdel-Khalik, S.I.; Corradini, M.L.; El-Afify, M.; Huh, K.Y.; Kuleinski, G.L.; Wittenberg, L.J.

    1985-07-01

    Among the specific limitations which tend to complicate a compact high wall loading (HWL) tokamak reactor design are high surface and nuclear heating, compactness leading to crowded components, unlikely breeding on the inboard side and frequent first wall/blanket replacement. This paper describes the mechanical, thermal hydraulic and tritium aspects of an improved blanket design for a high ..beta.. (20%), high wall loading (R 10 MW/m/sup 2/) compact fusion power reactor of 1000 MW /sub th/ power output.

  13. Retained gas inventory comparison

    SciTech Connect

    BARTON, W.B.

    1999-05-18

    Gas volume data derived from four different analytical methods were collected and analyzed for comparison to volumes originally used in the technical basis for the Basis for Interim Operations (BIO). The original volumes came from Hodgson (1996) listed in the reference section of this document. Hodgson (1996) screened all 177 single and double-shell tanks for the presence of trapped gas in waste via two analytical methods: Surface Level Rise (SLR), and Barometric Pressure Effect (BPE). More recent gas volume projections have been calculated using different analytical techniques along with updates to the parameters used as input to the SLR and BPE models. Gas volumes derived from new analytical instruments include those as measured by the Void Fraction Instrument (VFI) and Retained Gas Sampler (RGS). The results of this comparison demonstrate that the original retained gas volumes of Hodgson (1996) used as a technical basis in developing the BIO were conservative, and were conservative from a safety analysis standpoint. These results represent only comparisons to the original reported volumes using the limited set of newly acquired data that is available.

  14. Differentiating the role of lithium and oxygen in retaining deuterium on lithiated graphite plasma-facing components

    SciTech Connect

    Taylor, C. N.; Allain, J. P.; Luitjohan, K. E.; Krstic, P. S.; Dadras, J.; Skinner, C. H.

    2014-05-15

    Laboratory experiments have been used to investigate the fundamental interactions responsible for deuterium retention in lithiated graphite. Oxygen was found to be present and play a key role in experiments that simulated NSTX lithium conditioning, where the atomic surface concentration can increase to >40% when deuterium retention chemistry is observed. Quantum-classical molecular dynamic simulations elucidated this oxygen-deuterium effect and showed that oxygen retains significantly more deuterium than lithium in a simulated matrix with 20% lithium, 20% oxygen, and 60% carbon. Simulations further show that deuterium retention is even higher when lithium is removed from the matrix. Experiments artificially increased the oxygen content in graphite to ∼16% and then bombarded with deuterium. X-ray photoelectron spectroscopy showed depletion of the oxygen and no enhanced deuterium retention, thus demonstrating that lithium is essential in retaining the oxygen that thereby retains deuterium.

  15. Differentiating the role of lithium and oxygen in retaining deuterium on lithiated graphite plasma-facing components

    SciTech Connect

    C.N. Taylor; J. P. Allain; P. S. Krstic; J. Dadras; C. H. Skinner; K. E. Luitjohan

    2013-11-01

    Laboratory experiments have been used to investigate the fundamental interactions responsible for deuterium retention in lithiated graphite. Oxygen was found to be present and play a key role in experiments that simulated NSTX lithium conditioning, where the atomic surface concentration can increase to >40% when deuterium retention chemistry is observed. Quantum-classical molecular dynamic simulations elucidated this oxygen-deuterium effect and showed that oxygen retains significantly more deuterium than lithium in a simulated matrix with 20% lithium, 20% oxygen, and 60% carbon. Simulations further show that deuterium retention is even higher when lithium is removed from the matrix. Experiments artificially increased the oxygen content in graphite to approximately 16% and then bombarded with deuterium. XPS showed depletion of the oxygen and no enhanced deuterium retention, thus demonstrating that lithium is essential in retaining the oxygen that thereby retains deuterium.

  16. How to Retain the Trust of Patients and Families When We Will Not Provide the Treatment They Want.

    PubMed

    Howe, Edmund G

    2015-01-01

    How might clinicians best try to retain the trust of patients and family members after clinicians oppose giving a treatment? If clinicians can maintain the trust of patients and families in these situations, this may soften what may be the greatest possible loss--the death of a loved one. I discuss what clinicians seeking to retain trust should not do--namely impose their values and reason wrongly--and introduce strategies that clinicians may use to reduce both. I present five principles that clinicians can follow to try to retain trust, with examples that illustrate each. I suggest specific interventions that clinicians can make, especially when they anticipate that a patient and/or family may, in time, want a treatment that is futile. PMID:26132054

  17. Application of sludge from urban wastewater treatment plants in road's embankments.

    PubMed

    De Oña, J; Osorio, F

    2006-04-17

    While different kinds of compost have been tested for highway revegetation, sewage sludge has only been used for agricultural purposes. In this work, its application for helping vegetation establishment on roads embankments is studied. Testing areas measuring 4x5m were constructed on a new highway embankment in an arid location. Several variables are analyzed: side slope (2); sludge dosage (4); vegetative species (4). Results are presented on growth, survival rate and germination of the plants; colonization of other species; cover crop for the plots; estimation of the erosion. The species planted manually showed satisfactory results although any variable was specially significant in this case. However, in relation to the species planted using hydroseeding, 2:1 side slope presented better results than 3:2 side slope. Using hydroseeding, the performance of different species was significantly different, thyme did not grow if sludge was not applied and the cover crop was higher in plots with 3:2 side slope than in plots with 2:1 side slope, essentially due to the presence of colonizing species. Finally, the costs of the proposed treatments are figured out, being concluded that, so much from the technical as the economic point of view, it is a viable proposal for sewage sludge management. PMID:16233951

  18. Quick locking/unlocking retainer

    NASA Technical Reports Server (NTRS)

    Okamoto, G.; Williams, B. B.

    1979-01-01

    Spring clip retainer may prove more convenient than clamps or wingnut and stud combination when holding two small parts together in test fixtures and other applications where parts must be frequently moved or changed.

  19. Wall slip and fluidity in emulsion flow

    NASA Astrophysics Data System (ADS)

    Paredes, José; Shahidzadeh, Noushine; Bonn, Daniel

    2015-10-01

    The microscopic origin of apparent wall slip is studied systematically using a confocal laser scanning microscope coupled to a rheometer. We obtain flow curves on a model emulsion from classical macroscopic measurements that are compared with flow curves obtained from microscopic measurements. By controlling the wetting properties of the shearing walls, we show that the characteristic length used in the so-called fluidity model, proposed by Goyon et al. [Nature (London) 454, 84 (2008), 10.1038/nature07026], can be understood in terms of roughness induced by adsorbed droplets on the surface. Additionally, we disentangle two different effects that contribute to the difference between micro- and macrorheology. Both effects manifest themselves as gap-dependent viscosities due to either the formation of a lubricating layer close to the shearing walls or cooperative effects when the flow is strongly confined. Finally, we show that the cooperative effects can also be translated into an effective slip velocity.

  20. 17. DETAIL OF INTERIOR AND EXTERIOR WALL CONSTRUCTION, VIEW TOWARD ...

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

    17. DETAIL OF INTERIOR AND EXTERIOR WALL CONSTRUCTION, VIEW TOWARD NORTHEAST CORNER, THIRD BAY Showing insulated exterior wall at right; asphalt felt on interior separation wall at left; sill beam, stud, and concrete foundation detailing of interior wall. - U.S. Military Academy, Ice House, Mills Road at Howze Place, West Point, Orange County, NY

  1. Attracting, equipping and retaining young medical doctors in HIV vaccine science in South Africa

    PubMed Central

    Flood, Danna; Wallace, Melissa; Bloch, Kimberly; Kublin, James; Bekker, Linda-Gail

    2016-01-01

    Background HIV remains a significant health problem in South Africa (SA). The development of a preventive vaccine offers promise as a means of addressing the epidemic, yet development of the human resource capacity to facilitate such research in SA is not being sustained. The HIV Vaccine Trials Network (HVTN) has responded by establishing South African/HVTN AIDS Early Stage Investigator Programme (SHAPe), a programme to identify, train and retain clinician scientists in HIV vaccine research in SA. Objectives The present study sought to identify factors influencing the attraction and retention of South African medical doctors in HIV vaccine research; to understand the support needed to ensure their success; and to inform further development of clinician research programmes, including SHAPe. Methods Individual interviews and focus groups were held and audio-recorded with 18 senior and junior research investigators, and medical doctors not involved in research. Recordings were transcribed, and data were coded and analysed. Results Findings highlighted the need for: (1) medical training programmes to include a greater focus on fostering interest and developing research skills, (2) a more clearly defined career pathway for individuals interested in clinical research, (3) an increase in programmes that coordinate and fund research, training and mentorship opportunities and (4) access to academic resources such as courses and libraries. Unstable funding sources and inadequate local funding support were identified as barriers to promoting HIV research careers. Conclusion Expanding programmes that provide young investigators with funded research opportunities, mentoring, targeted training and professional development may help to build and sustain SA’s next generation of HIV vaccine and prevention scientists.

  2. Potential risk indicators of retained placenta and other diseases in multiparous cows.

    PubMed

    Qu, Y; Fadden, A N; Traber, M G; Bobe, G

    2014-07-01

    Retained placenta (RP), defined as fetal membranes not being expelled within 24 h after calving, is a costly disease in multiparous dairy cows that has been linked to immune suppression, infections, elevated lipid mobilization, and depleted status of antioxidants including α-tocopherol, and that increases the risk of other diseases (OD) in early lactation. Early detection of cows at increased risk of developing RP, OD, or both in early lactation could improve treatment success and result in improved milk production and reproductive performance. To identify risk indicators of RP, OD, or both, we used a nested case-control design and compared multiparous dairy cows that developed RP (n=32) with cows that remained healthy (H; n=32) or cows that developed OD (n=32) in early lactation. We compared peripartal body condition score (BCS) as well as serum concentrations of α-tocopherol, metabolites [β-hydroxybutyrate (BHBA), cholesterol, glucose, nonesterified fatty acids (NEFA), and urea N], haptoglobin, and macrominerals (i.e., calcium, magnesium, and phosphorus) on d -21, -14, -7, -3, -1, 0, 1, 3, 7, 14, 21, 28, 35, 42, and 49 postpartum. In addition, average serum concentrations were calculated for each cow for the last 3 wk prepartum, for 3 and 2 wk prepartum combined, for the last week prepartum, and for the morning after calving and compared between groups. The RP cows had lower BCS than the H or OD cows until 2 wk postpartum. During the prepartal periods, RP and OD cows had lower α-tocopherol concentrations (corrected or not for cholesterol concentration) and higher NEFA and BHBA concentrations than H cows. Thus, lower prepartal BCS could be an early predictor for RP risk, and lower α-tocopherol concentrations and higher NEFA and BHBA concentrations could be early predictors for disease. PMID:24792789

  3. A Qualitative Study of the Personal Reactions and Experiences of Adolescent Students Who Have Been Retained

    ERIC Educational Resources Information Center

    Fournier, Jessica Robertson

    2009-01-01

    Grade retention is an educational practice that requires students to repeat the grade level they have just completed (Jimerson, 2001). In the United States, an estimated 15% to 19% of students are retained each year (Holmes, 2006). Previous research on grade retention is comprised of quantitative studies describing students who have been retained…

  4. Peer Contexts: Do Old for Grade and Retained Peers Influence Student Behavior in Middle School?

    ERIC Educational Resources Information Center

    Muschkin, Clara G.; Glennie, Elizabeth; Beck, Audrey N.

    2014-01-01

    Background: Many school systems have ended social promotion by implementing accountability systems where students who fail academic assessments are retained in grade. Additionally, some parents have delayed their children's entry into school, believing that older students have an advantage. While research has examined outcomes for students…

  5. Does the Relationship between Retained Mandibular Third Molar and Mandibular Angle Fracture Exist? An Assessment of Three Possible Causes

    PubMed Central

    Duarte, Bruno G.; Assis, Diogo; Ribeiro-Júnior, Paulo; Gonçales, Eduardo Sanches

    2012-01-01

    The objective of this study is to discuss problems associated with dental retention through three clinical cases of mandible fractures related to the presence of retained lower third molars, emphasizing the possibility of mandible fractures resulting from this or from the extraction procedure. The three evaluated patients had a fracture in the mandible angle. The third molars were present in all the cases, as was the relationship of the fracture with the teeth. After evaluating the three cases and reviewing literature, it is believed that the presence of the retained lower third molars and the surgical procedures for their extraction increase the risk of mandible angle fractures. PMID:23997857

  6. Stem Cells Expanded from the Human Embryonic Hindbrain Stably Retain Regional Specification and High Neurogenic Potency

    PubMed Central

    Tailor, Jignesh; Kittappa, Raja; Leto, Ketty; Gates, Monte; Borel, Melodie; Paulsen, Ole; Spitzer, Sonia; Karadottir, Ragnhildur Thora; Rossi, Ferdinando

    2013-01-01

    Stem cell lines that faithfully maintain the regional identity and developmental potency of progenitors in the human brain would create new opportunities in developmental neurobiology and provide a resource for generating specialized human neurons. However, to date, neural progenitor cultures derived from the human brain have either been short-lived or exhibit restricted, predominantly glial, differentiation capacity. Pluripotent stem cells are an alternative source, but to ascertain definitively the identity and fidelity of cell types generated solely in vitro is problematic. Here, we show that hindbrain neuroepithelial stem (hbNES) cells can be derived and massively expanded from early human embryos (week 5–7, Carnegie stage 15–17). These cell lines are propagated in adherent culture in the presence of EGF and FGF2 and retain progenitor characteristics, including SOX1 expression, formation of rosette-like structures, and high neurogenic capacity. They generate GABAergic, glutamatergic and, at lower frequency, serotonergic neurons. Importantly, hbNES cells stably maintain hindbrain specification and generate upper rhombic lip derivatives on exposure to bone morphogenetic protein (BMP). When grafted into neonatal rat brain, they show potential for integration into cerebellar development and produce cerebellar granule-like cells, albeit at low frequency. hbNES cells offer a new system to study human cerebellar specification and development and to model diseases of the hindbrain. They also provide a benchmark for the production of similar long-term neuroepithelial-like stem cells (lt-NES) from pluripotent cell lines. To our knowledge, hbNES cells are the first demonstration of highly expandable neuroepithelial stem cells derived from the human embryo without genetic immortalization. PMID:23884946

  7. Identification, origin and evidence for retained functionality of two IκBα paralogs in Megalobrama amblycephala.

    PubMed

    Jakovlić, Ivan; Liu, Han; Wang, Wei-Min

    2016-09-01

    IκBα plays an essential role in the innate immune response in mammals. We found two functional IκBα paralogs, originating from the teleost-specific genome duplication, in Megalobrama amblycephala: maIκBαa and maIκBαb. Their size (936/933 bp) and structure are highly analogous to known orthologs. mRNA expression was analysed by qPCR in spleen, liver, kidney, intestine and gills. Apart from maIκBαb in gills (<0.001-fold), both paralogs were constitutively expressed in all tissues. Differential expression was observed in gills (high for maIκBαa) and liver: maIκBαa - 2nd lowest (0.47), maIκBαb - 2nd highest (4.25). Both paralogs (mRNA) were upregulated in liver, spleen and kidney after a bacterial (Aeromonas hydrophila) challenge. In spleen, expressions peaked at 12 h post injection (hpi) (maIκBαa = 14.3-fold, maIκBαb = 21.3-fold), but only maIκBαb was highly upregulated at 4, 24 and 120 hpi. In liver, both were upregulated early, but maIκBαa peaked at 4 hpi (15.2-fold) and maIκBαb at 12 hpi (9.8-fold). In kidney, maIκBαa was highly upregulated only at 12 hpi (8.7-fold), and maIκBαb at 4 (peak - 8.2-fold), 12 and 24 hpi. The results indicate that both IκBα paralogs have retained their functionality, that they are structurally and functionally homologous to IκBα orthologs described in other animal species, and that they both play an important role in the innate immune system of M. amblycephala. PMID:27155355

  8. Tearing Down the Wall: Literature and Science.

    ERIC Educational Resources Information Center

    Westcott, Warren B.; Spell, J. Everett

    1999-01-01

    Suggests English teachers might draw from authors such as Carl Sagan, Arthur C. Clarke, Mary Shelly and others: (1) to knock down the walls that separate science and literature; (2) to show their interrelationship; and (3) to instill enthusiasm for the study of both. (NH)

  9. Dry under water: comparative morphology and functional aspects of air-retaining insect surfaces.

    PubMed

    Balmert, Alexander; Florian Bohn, Holger; Ditsche-Kuru, Petra; Barthlott, Wilhelm

    2011-04-01

    Superhydrophobic surfaces prevent certain body parts of semiaquatic and aquatic insects from getting wet while submerged in water. The air layer on these surfaces can serve the insects as a physical gill. Using scanning electron microscopy, we investigated the morphology of air-retaining surfaces in five insect species with different levels of adaptation to aquatic habitats. We found surfaces with either large and sparse hairs (setae), small and dense hairs (microtrichia), or hierarchically structured surfaces with both types of hairs. The structural parameters and air-film persistence of these surfaces were compared. Air-film persistence varied between 2 days in the beetle Galerucella nymphaea possessing only sparse setae and more than 120 days in the bugs Notonecta glauca and Ilyocoris cimicoides possessing dense microtrichia (up to 6.6 × 10(6) microtrichia per millimeter square). From our results, we conclude that the density of the surface structures is the most important factor that affects the persistence of air films. Combinations of setae and microtrichia are not decisive for the overall persistence of the air film but might provide a thick air store for a short time and a thin but mechanically more stable air film for a long time. Thus, we assume that a dense cover of microtrichia acts as a "backup system" preventing wetting of the body surface in case the air-water interface is pressed toward the surface. Our findings might be beneficial for the development of biomimetic surfaces for long-term air retention and drag reduction under water. In addition, the biological functions of the different air retention capabilities are discussed. PMID:21290417

  10. Instrumental and sensory quantification of oral coatings retained after swallowing semi-solid foods.

    PubMed

    Prinz, J F; Huntjens, L; de Wijk, R A

    2006-12-01

    After a mouthful of food has been swallowed, some food material is always retained in the mouth. With semi-solid foods this is in the form of a coating that adheres to the oral mucosa. The amount and location of this material may play an important role in food sensations. In this study two quantitative methods of describing the coatings, generated by a set of 16 model custards varying in degree of lubrication (fat content) and degree of viscosity (starch concentration) are investigated. In the first method, a trained quantitative descriptive analysis panel (N=8) was instructed to take single mouthfuls of semi-solid foods, swallow and then rinse twice for 5s with water and spit out. The turbidity of the rinse water was then measured. During the same session, sensory assessments of the products were obtained. In the second method the thickness of the coating on the anterior and middle one-thirds of the tongue was quantified using a pair of opto-electronic reflectance sensors mounted on a probe which was placed on the tongue, one sensor measuring the anterior part of the tongue the other the posterior (middle third) of the tongue. Turbidity of the first rinse related strongly to the food's viscosity, as well as to sensory attributes associated with the food's fat content and viscosity, such as perceived thickness, creaminess and fattiness. Turbidity of subsequent rinses related primarily to fat content. These results indicate that turbidity of rinse water is a useful tool in fundamental (e.g., food texture research) as well as applied research (e.g., product development and quality assurance in food industry). Reflectance varied primarily with fat content and did not relate well to sensory attributes. PMID:17045954

  11. Retaining Your IT Staff: Insights from the ECAR Workforce Study for Higher Education CIOs and IT. ECAR Research Bulletin

    ERIC Educational Resources Information Center

    Bichsel, Jacqueline

    2014-01-01

    Today's higher education IT organization needs a "lean and mean" cadre of staff who possess skills that are both deep and broad. Recruiting and developing the right team is an endeavor requiring much time, effort, and resources. How then do you make the most of this investment and retain the individuals who provide so much value to the…

  12. Abdominal wall herniae and their underlying pathology

    PubMed Central

    Upchurch, Emma; Al-Akash, Musallam

    2016-01-01

    We describe a case of pseudomyxoma peritonei presenting as a strangulated inguinal hernia. We review the current literature regarding the incidence of underlying pathology in patients presenting with abdominal wall herniae and discuss the need for histological assessment of the hernia sac in selected patients. We highlight the importance of assessing for and being aware of significant underlying pathology in certain patients. PMID:26855074

  13. 31 CFR 1010.420 - Records to be made and retained by persons having financial interests in foreign financial accounts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Records to be made and retained by persons having financial interests in foreign financial accounts. 1010.420 Section 1010.420 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FINANCIAL CRIMES ENFORCEMENT NETWORK, DEPARTMENT OF THE TREASURY...

  14. 25 CFR 171.600 - What information is collected and retained on the irrigation service I receive?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... irrigation service I receive? 171.600 Section 171.600 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER IRRIGATION OPERATION AND MAINTENANCE Records, Agreements, and Other Matters § 171.600 What information is collected and retained on the irrigation service I receive? We will...

  15. 25 CFR 171.600 - What information is collected and retained on the irrigation service I receive?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... irrigation service I receive? 171.600 Section 171.600 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER IRRIGATION OPERATION AND MAINTENANCE Records, Agreements, and Other Matters § 171.600 What information is collected and retained on the irrigation service I receive? We will...

  16. 25 CFR 171.600 - What information is collected and retained on the irrigation service I receive?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... irrigation service I receive? 171.600 Section 171.600 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER IRRIGATION OPERATION AND MAINTENANCE Records, Agreements, and Other Matters § 171.600 What information is collected and retained on the irrigation service I receive? We will...

  17. 25 CFR 171.600 - What information is collected and retained on the irrigation service I receive?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... irrigation service I receive? 171.600 Section 171.600 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER IRRIGATION OPERATION AND MAINTENANCE Records, Agreements, and Other Matters § 171.600 What information is collected and retained on the irrigation service I receive? We will...

  18. 25 CFR 171.600 - What information is collected and retained on the irrigation service I receive?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... irrigation service I receive? 171.600 Section 171.600 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER IRRIGATION OPERATION AND MAINTENANCE Records, Agreements, and Other Matters § 171.600 What information is collected and retained on the irrigation service I receive? We will...

  19. The dynamics of domain walls and strings

    NASA Technical Reports Server (NTRS)

    Gregory, Ruth; Haws, David; Garfinkle, David

    1989-01-01

    The leading order finite-width corrections to the equation of motion describing the motion of a domain wall are derived. The regime in which this equation of motion is invalid is discussed. Spherically and cylindrically symmetric solutions to this equation of motion are found. A misconception that has arisen in recent years regarding the rigidity (or otherwise) of cosmic strings is also clarified.

  20. Educating Farmers' Market Consumers on Best Practices for Retaining Maximum Nutrient and Phytonutrient Levels in Local Produce

    ERIC Educational Resources Information Center

    Ralston, Robin A.; Orr, Morgan; Goard, Linnette M.; Taylor, Christopher A.; Remley, Dan

    2016-01-01

    Few farmers' market consumers are aware of how to retain optimal nutritional quality of produce following purchase. Our objective was to develop and evaluate educational materials intended to inform market consumers about best practices for storing, preserving, and consuming local produce to maximize nutrients and phytonutrients. Printed…

  1. Bicruciate retaining arthroplasty.

    PubMed

    Mont, Michael A; John, Mario; Johnson, Aaron

    2012-12-01

    Total knee arthroplasty (TKA) is one of the most successful orthopaedic procedures with 10 to 20 year survivorships from multiple studies of greater than 95%. These success rates typically apply to patients over 70 years of age who may only want to return to activities of daily living. However, recently there is a demand by both senior citizens as well as young patients to have TKAs that return them to high activity levels and occasionally high performance sports. In this review, we will describe bicruciate retaining prostheses, including knowledge of their kinematics from fluoroscopic and gait studies, results of clinical studies, a summary of their potential advantages and disadvantages, anterior cruciate ligament viability at time of arthroplasty, considerations for implantation of these devices, and their role in the future of total knee arthroplasty. PMID:22915498

  2. Effects of age, weight, and fat slaughter end points on estimates of breed and retained heterosis effects for carcass traits.

    PubMed

    Ríos-Utrera, A; Cundiff, L V; Gregory, K E; Koch, R M; Dikeman, M E; Koohmaraie, M; Van Vleck, L D

    2006-01-01

    The influence of different levels of adjusted fat thickness (AFT) and HCW slaughter end points (covariates) on estimates of breed and retained heterosis effects was studied for 14 carcass traits from serially slaughtered purebred and composite steers from the US Meat Animal Research Center (MARC). Contrasts among breed solutions were estimated at 0.7, 1.1, and 1.5 cm of AFT, and at 295.1, 340.5, and 385.9 kg of HCW. For constant slaughter age, contrasts were adjusted to the overall mean (432.5 d). Breed effects for Red Poll, Hereford, Limousin, Braunvieh, Pinzgauer, Gelbvieh, Simmental, Charolais, MARC I, MARC II, and MARC III were estimated as deviations from Angus. In addition, purebreds were pooled into 3 groups based on lean-to-fat ratio, and then differences were estimated among groups. Retention of combined individual and maternal heterosis was estimated for each composite. Mean retained heterosis for the 3 composites also was estimated. Breed rankings and expression of heterosis varied within and among end points. For example, Charolais had greater (P < 0.05) dressing percentages than Angus at the 2 largest levels of AFT and smaller (P < 0.01) percentages at the 2 largest levels of HCW, whereas the 2 breeds did not differ (P > or = 0.05) at a constant age. The MARC III composite produced 9.7 kg more (P < 0.01) fat than Angus at AFT of 0.7 cm, but 7.9 kg less (P < 0.05) at AFT of 1.5 cm. For MARC III, the estimate of retained heterosis for HCW was significant (P < 0.05) at the lowest level of AFT, but at the intermediate and greatest levels estimates were nil. The pattern was the same for MARC I and MARC III for LM area. Adjustment for age resulted in near zero estimates of retained heterosis for AFT, and similarly, adjustment for HCW resulted in nil estimates of retained heterosis for LM area. For actual retail product as a percentage of HCW, the estimate of retained heterosis for MARC III was negative (-1.27%; P < 0.05) at 0.7 cm but was significantly

  3. The Influence of a Lilly Endowment Grant to Recruit and Retain Part-Time Faculty in a Community College System

    ERIC Educational Resources Information Center

    Lepper, Charles Wilmer

    2010-01-01

    This qualitative study examines the influence of a grant from the Lilly Endowment to recruit and retain intellectual capital of part-time faculty in a community college system. Through the use of grant funds, the college used in this study developed and implemented nine college-wide initiatives. This study examined adjunct faculty members'…

  4. Evaluation of Beef Cattle Operations Utilizing Different Seasons of Calving, Weaning Strategies, Post-weaning Management, and Retained Ownership

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Production data from a 3-yr study conducted at Fort Keogh Livestock and Range Research Laboratory near Miles City, MT were utilized to evaluate impacts of season of calving, weaning strategy, post-weaning management of replacement heifers, and retained ownership of steer calves on enterprise profita...

  5. Geoelectrical Monitoring for Observation of Changes in Water Content in the Slope of an Embankment Caused By Heavy Rain Using a Large-Scale Rainfall Simulator

    NASA Astrophysics Data System (ADS)

    Takakura, S.; Yoshioka, M.; Ishizawa, T.; Sakai, N.

    2014-12-01

    Measuring the temporal variation of water content along a slope is important for predicting and preventing slope disasters. We conducted repeated monthly geoelectrical surveys since February 2011 on one slope of an embankment in the large-scale rainfall simulator of the National Research Institute for Earth Science and Disaster Prevention (NIED). In order to confirm the relationship between water content and resistivity changes in the slope due to heavy rain, we conducted seven artificial rain experiments at the embankment, controlling the total amount and intensity of rainfall using the mobile rainfall simulator. We observed soil water content and conducted geoelectrical measurements on the slope of the embankment before, during and after the artificial rains. It is difficult to obtain the rapid change of resistivity structure due to the rain because the analysis of resistivity structure requires measurement by much electrode array combination. Therefore, we performed only a continuous measurement using a Wenner array with "a" spacing of 0.5 m and 1 m. The changes in analyzed resistivity took place almost simultaneously with changes in water content. The fall of resistivity accelerates as the intensity of rainfall increases. The resistivity changed significantly with a rapid change in water content. The change in resistivity is slightly earlier than the change in volumetric water content at the same depth. These facts indicate that geoelectrical monitoring is effective for observing changes in the water content of the slope of an embankment caused by heavy rain.

  6. Plant cell wall dynamics and wall-related susceptibility in plant–pathogen interactions

    PubMed Central

    Bellincampi, Daniela; Cervone, Felice; Lionetti, Vincenzo

    2014-01-01

    The cell wall is a dynamic structure that often determines the outcome of the interactions between plants and pathogens. It is a barrier that pathogens need to breach to colonize the plant tissue. While fungal necrotrophs extensively destroy the integrity of the cell wall through the combined action of degrading enzymes, biotrophic fungi require a more localized and controlled degradation of the cell wall in order to keep the host cells alive and utilize their feeding structures. Also bacteria and nematodes need to degrade the plant cell wall at a certain stage of their infection process, to obtain nutrients for their growth. Plants have developed a system for sensing pathogens and monitoring the cell wall integrity, upon which they activate defense responses that lead to a dynamic cell wall remodeling required to prevent the disease. Pathogens, on the other hand, may exploit the host cell wall metabolism to support the infection. We review here the strategies utilized by both plants and pathogens to prevail in the cell wall battleground. PMID:24904623

  7. The Plant Cell Wall: A Complex and Dynamic Structure As Revealed by the Responses of Genes under Stress Conditions.

    PubMed

    Houston, Kelly; Tucker, Matthew R; Chowdhury, Jamil; Shirley, Neil; Little, Alan

    2016-01-01

    The plant cell wall has a diversity of functions. It provides a structural framework to support plant growth and acts as the first line of defense when the plant encounters pathogens. The cell wall must also retain some flexibility, such that when subjected to developmental, biotic, or abiotic stimuli it can be rapidly remodeled in response. Genes encoding enzymes capable of synthesizing or hydrolyzing components of the plant cell wall show differential expression when subjected to different stresses, suggesting they may facilitate stress tolerance through changes in cell wall composition. In this review we summarize recent genetic and transcriptomic data from the literature supporting a role for specific cell wall-related genes in stress responses, in both dicot and monocot systems. These studies highlight that the molecular signatures of cell wall modification are often complex and dynamic, with multiple genes appearing to respond to a given stimulus. Despite this, comparisons between publically available datasets indicate that in many instances cell wall-related genes respond similarly to different pathogens and abiotic stresses, even across the monocot-dicot boundary. We propose that the emerging picture of cell wall remodeling during stress is one that utilizes a common toolkit of cell wall-related genes, multiple modifications to cell wall structure, and a defined set of stress-responsive transcription factors that regulate them. PMID:27559336

  8. The Plant Cell Wall: A Complex and Dynamic Structure As Revealed by the Responses of Genes under Stress Conditions

    PubMed Central

    Houston, Kelly; Tucker, Matthew R.; Chowdhury, Jamil; Shirley, Neil; Little, Alan

    2016-01-01

    The plant cell wall has a diversity of functions. It provides a structural framework to support plant growth and acts as the first line of defense when the plant encounters pathogens. The cell wall must also retain some flexibility, such that when subjected to developmental, biotic, or abiotic stimuli it can be rapidly remodeled in response. Genes encoding enzymes capable of synthesizing or hydrolyzing components of the plant cell wall show differential expression when subjected to different stresses, suggesting they may facilitate stress tolerance through changes in cell wall composition. In this review we summarize recent genetic and transcriptomic data from the literature supporting a role for specific cell wall-related genes in stress responses, in both dicot and monocot systems. These studies highlight that the molecular signatures of cell wall modification are often complex and dynamic, with multiple genes appearing to respond to a given stimulus. Despite this, comparisons between publically available datasets indicate that in many instances cell wall-related genes respond similarly to different pathogens and abiotic stresses, even across the monocot-dicot boundary. We propose that the emerging picture of cell wall remodeling during stress is one that utilizes a common toolkit of cell wall-related genes, multiple modifications to cell wall structure, and a defined set of stress-responsive transcription factors that regulate them. PMID:27559336

  9. Surface tension driven processes densify and retain permeability in magma and lava

    NASA Astrophysics Data System (ADS)

    Kennedy, Ben M.; Wadsworth, Fabian B.; Vasseur, Jérémie; Ian Schipper, C.; Mark Jellinek, A.; von Aulock, Felix W.; Hess, Kai-Uwe; Kelly Russell, J.; Lavallée, Yan; Nichols, Alexander R. L.; Dingwell, Donald B.

    2016-01-01

    We offer new insights into how an explosive eruption can transition into an effusive eruption. Magma containing >0.2 wt% dissolved water has the potential to vesiculate to a porosity in excess of 80 vol.% at atmospheric pressure. Thus all magmas contain volatiles at depth sufficient to form foams and explosively fragment. Yet gas is often lost passively and effusive eruptions ensue. Magmatic foams are permeable and understanding permeability in magma is crucial for models that predict eruptive style. Permeability also governs magma compaction models. Those models generally imply that a reduction in magma porosity and permeability generates an increased propensity for explosivity. Here, our experimental results show that surface tension stresses drive densification without creating an impermeable 'plug', offering an additional explanation of why dense magmas can avoid explosive eruption. In both an open furnace and a closed autoclave, we subject pumice samples with initial porosity of ∼70 vol.% to a range of isostatic pressures (0.1-11 MPa) and temperatures (350-950 °C) relevant to shallow volcanic environments. Our experimental data and models constrain the viscosity, permeability, timescales, and length scales over which densification by pore-scale surface tension stresses competes with density-driven compaction. Where surface tension dominates the dynamics, densification halts at a plateau connected porosity of ∼25 vol.% for our samples. SEM, pycnometry and micro-tomography show that in this process (1) microporous networks are destroyed, (2) the relative pore network surface area decreases, and (3) a remaining crystal framework enhances the longevity of macro-pore connectivity and permeability critical for sustained outgassing. We propose that these observations are a consequence of a surface tension-driven retraction of viscous pore walls at areas of high bubble curvature (micro-vesicular network terminations), and that this process drives bulk

  10. The role of automated feedback in training and retaining biological recorders for citizen science.

    PubMed

    van der Wal, René; Sharma, Nirwan; Mellish, Chris; Robinson, Annie; Siddharthan, Advaith

    2016-06-01

    The rapid rise of citizen science, with lay people forming often extensive biodiversity sensor networks, is seen as a solution to the mismatch between data demand and supply while simultaneously engaging citizens with environmental topics. However, citizen science recording schemes require careful consideration of how to motivate, train, and retain volunteers. We evaluated a novel computing science framework that allowed for the automated generation of feedback to citizen scientists using natural language generation (NLG) technology. We worked with a photo-based citizen science program in which users also volunteer species identification aided by an online key. Feedback is provided after photo (and identification) submission and is aimed to improve volunteer species identification skills and to enhance volunteer experience and retention. To assess the utility of NLG feedback, we conducted two experiments with novices to assess short-term (single session) and longer-term (5 sessions in 2 months) learning, respectively. Participants identified a specimen in a series of photos. One group received only the correct answer after each identification, and the other group received the correct answer and NLG feedback explaining reasons for misidentification and highlighting key features that facilitate correct identification. We then developed an identification training tool with NLG feedback as part of the citizen science program BeeWatch and analyzed learning by users. Finally, we implemented NLG feedback in the live program and evaluated this by randomly allocating all BeeWatch users to treatment groups that received different types of feedback upon identification submission. After 6 months separate surveys were sent out to assess whether views on the citizen science program and its feedback differed among the groups. Identification accuracy and retention of novices were higher for those who received automated feedback than for those who received only confirmation of the

  11. Stability of resistive wall modes with plasma rotation and thick wall in ITER scenario

    NASA Astrophysics Data System (ADS)

    Zheng, L. J.; Kotschenreuther, M.; Chu, M.; Chance, M.; Turnbull, A.

    2004-11-01

    The rotation effect on resistive wall modes (RWMs) is examined for realistically shaped, high-beta tokamak equilibria, including reactor relevant cases with low mach number M and realistic thick walls. For low M, Stabilization of RWMs arises from unusually thin inertial layers. The investigation employs the newly developed adaptive eigenvalue code (AEGIS: Adaptive EiGenfunction Independent Solution), which describes both low and high n modes and is in good agreement with GATO in the benchmark studies. AEGIS is unique in using adaptive methods to resolve such inertial layers with low mach number rotation. This feature is even more desirable for transport barrier cases. Additionally, ITER and reactors have thick conducting walls ( ˜.5-1 m) which are not well modeled as a thin shell. Such thick walls are considered here, including semi-analytical approximations to account for the toroidally segmented nature of real walls.

  12. In situ microscopic analysis of asbestos and synthetic vitreous fibers retained in hamster lungs following inhalation.

    PubMed Central

    Rogers, R A; Antonini, J M; Brismar, H; Lai, J; Hesterberg, T W; Oldmixon, E H; Thevenaz, P; Brain, J D

    1999-01-01

    Hamsters breathed, nose-only, for 13 weeks, 5 days/week, 6 hr/day, either man-made vitreous fiber (MMVF)10a, MMVF33, or long amosite asbestos at approximately 300 World Health Organization (WHO) fibers/cc or long amosite at 25 WHO fibers/cc. [World Health Organization fibers are longer than 5 microm and thicker than 3 microm, with aspect ratio >3.] After sacrifice, fiber burden was estimated (left lungs) by ashing and scanning electron microscopy (ashing/SEM) or (right middle lobes) by confocal laser scanning microscopy (CLSM) in situ. In situ CLSM also provided three-dimensional views of fibers retained, undisturbed, in lung tissue. Fibers of each type were lodged in alveoli and small airways, especially at airway bifurcations, and were seen fully or partly engulfed by alveolar macrophages. Amosite fibers penetrated into and through alveolar septa. Length densities of fibers in parenchyma (total length of fiber per unit volume of lung) were estimated stereologically from fiber transsections counted on two-dimensional optical sections and were 30.5, 25.3, 20.0, and 81.6 mm/mm3 for MMVF10a, MMVF33, and low- and high-dose amosite, respectively. Lengths of individual fibers were measured in three dimensions by tracking individual fibers through series of optical sections. Length distributions of amosite fibers aerosolized, but before inhalation versus after retention in the lung were similar, whether determined by ashing/SEM or in situ CLSM. In contrast, the fraction of short MMVF10a and MMVF33 fibers increased and the geometric mean fiber lengths of both MMVFs decreased by approximately 60% during retention. Most likely due to fiber deposition pattern and differences in sampling, fiber burdens [MMVF10a, MMVF33, and amosite (high dose; 269 WHO fibers/cc)] determined by ashing/SEM were 1.4, 1. 5, and 3.5 times greater, respectively, than those calculated from in situ CLSM data. In situ CLSM is able to provide detailed information about the anatomic sites of fiber

  13. Creating Authentic Research Centers In Secondary Classrooms And Retaining The Best Science Teachers

    NASA Astrophysics Data System (ADS)

    Rodriguez, D.; McHenry, R. M.

    2006-12-01

    . Elementary through high school teachers in the state of Florida were contacted and asked to collect a sample of Spanish Moss from trees near their schools. These samples were sent to scientists and educators involved in the RET program at the National High Magnetic Field Lab who examined and compared the concentrations of a number of pollutants. When presented with a an opportunity leave the classroom two years ago to take on a new position, I decided to continue teaching middle school science, in large part due to my continued involvement in the research programs available at the the National High Magnetic Field Lab. Programs such as the RET program are essential to retaining the best science teachers in our schools.

  14. Retaining large and adjustable elastic strains of kilogram-scale Nb nanowires [Better Superconductor by Elastic Strain Engineering: Kilogram-scale Free-Standing Niobium Metal Composite with Large Retained Elastic Strains

    DOE PAGESBeta

    Hao, Shijie; Cui, Lishan; Wang, Hua; Jiang, Daqiang; Liu, Yinong; Yan, Jiaqiang; Ren, Yang; Han, Xiaodong; Brown, Dennis E.; Li, Ju

    2016-02-10

    Crystals held at ultrahigh elastic strains and stresses may exhibit exceptional physical and chemical properties. Individual metallic nanowires can sustain ultra-large elastic strains of 4-7%. However, retaining elastic strains of such magnitude in kilogram-scale nanowires is challenging. Here, we find that under active load, ~5.6% elastic strain can be achieved in Nb nanowires in a composite material. Moreover, large tensile (2.8%) and compressive (-2.4%) elastic strains can be retained in kilogram-scale Nb nanowires when the composite is unloaded to a free-standing condition. It is then demonstrated that the retained tensile elastic strains of Nb nanowires significantly increase their superconducting transitionmore » temperature and critical magnetic fields, corroborating ab initio calculations based on BCS theory. This free-standing nanocomposite design paradigm opens new avenues for retaining ultra-large elastic strains in great quantities of nanowires and elastic-strain-engineering at industrial scale.« less

  15. Dynamic Acoustic Radiation Force Retains Bone Structural and Mechanical Integrity in a Functional Disuse Osteopenia Model

    PubMed Central

    Uddin, Sardar M. Z.; Qin, Yi-Xian

    2015-01-01

    femurs. LIPUS provides the essential mechanical stimulus to retain bone morphological and mechanical integrity in disuse conditions. This study demonstrates LIPUS potential as regional therapeutic agent to countermeasure disuse induced bone loss while maintaining bone's integrity. PMID:25661670

  16. Study on optimal inertial-confinement-fusion hohlraum wall radial density and wall loss

    SciTech Connect

    Zhang Lu; Wu Shunchao; Ding Yongkun; Yang Jiamin; Jiang Shaoen

    2011-03-15

    Reducing hohlraum wall loss is one of the most important ways to improve hohlraum coupling efficiency in laser indirect drive inertial-confinement fusion. It is appeared that a high Z metallic foam as hohlraum wall material will reduce wall loss. By adjusting initial hohlraum wall density distribution along radial axes to {rho}{sub 0}(r)=kr, the numerical simulation results show that it can indeed bring best savings of {approx}40% general wall loss. We conclude that absorbed energy mainly decreases by restraining rarefactions, and a proper slope k can optimize internal energy loss of low density and increased kinetic loss by subsonic. Also saved energy ratio reduces with source temperature decreasing. This approach would cut the reactor driver that needs quite substantially if experiments demonstrate it.

  17. 30 CFR 57.20010 - Retaining dams.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Retaining dams. 57.20010 Section 57.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....20010 Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be...

  18. 30 CFR 56.20010 - Retaining dams.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Retaining dams. 56.20010 Section 56.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be of...

  19. Wall relaxation and the driving forces for cell expansive growth

    NASA Technical Reports Server (NTRS)

    Cosgrove, D. J.

    1987-01-01

    When water uptake by growing cells is prevented, the turgor pressure and the tensile stress in the cell wall are reduced by continued wall loosening. This process, termed in vivo stress relaxation, provides a new way to study the dynamics of wall loosening and to measure the wall yield threshold and the physiological wall extensibility. Stress relaxation experiments indicate that wall stress supplies the mechanical driving force for wall yielding. Cell expansion also requires water absorption. The driving force for water uptake during growth is created by wall relaxation, which lowers the water potential of the expanding cells. New techniques for measuring this driving force show that it is smaller than believed previously; in elongating stems it is only 0.3 to 0.5 bar. This means that the hydraulic resistance of the water transport pathway is small and that rate of cell expansion is controlled primarily by wall loosening and yielding.

  20. USDA earthen embankment dams: Defining the problem

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is estimated that there on the order of 2 to 9 million earthen dams in this country with 80,000 large or significant enough to be placed on the National Inventory of Dams (NID). This is an infrastructure that has significant issues related to: aging components; sedimentation; and changing hydrol...

  1. Controlled Patterning and Growth of Single Wall and Multi-wall Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Delzeit, Lance D. (Inventor)

    2005-01-01

    Method and system for producing a selected pattern or array of at least one of a single wall nanotube and/or a multi-wall nanotube containing primarily carbon. A substrate is coated with a first layer (optional) of a first selected metal (e.g., Al and/or Ir) and with a second layer of a catalyst (e.g., Fe, Co, Ni and/or Mo), having selected first and second layer thicknesses provided by ion sputtering, arc discharge, laser ablation, evaporation or CVD. The first layer and/or the second layer may be formed in a desired non-uniform pattern, using a mask with suitable aperture(s), to promote growth of carbon nanotubes in a corresponding pattern. A selected heated feed gas (primarily CH4 or C2Hn with n=2 and/or 4) is passed over the coated substrate and forms primarily single wall nanotubes or multiple wall nanotubes, depending upon the selected feed gas and its temperature. Nanofibers, as well as single wall and multi-wall nanotubes, are produced using plasma-aided growth from the second (catalyst) layer. An overcoating of a selected metal or alloy can be deposited, over the second layer, to provide a coating for the carbon nanotubes grown in this manner.

  2. 12 CFR 1805.504 - Retained earnings.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 9 2012-01-01 2012-01-01 false Retained earnings. 1805.504 Section 1805.504.... Retained earnings accumulated after the end of the Applicant's most recent fiscal year ending prior to the... over the Applicant's most recent fiscal year (e.g., retained earnings at the end of fiscal year...

  3. Modeling of Long-Term Fate of Mobilized Fines due to Dam-Embankment Interfacial Dislocations

    NASA Astrophysics Data System (ADS)

    Glascoe, L. G.; Ezzedine, S. M.; Kanarska, Y.; Lomov, I.; Antoun, T. H.

    2011-12-01

    Transverse cracks in embankment dams can develop as a result of post-construction settlements, earthquake deformations, or anthropogenic loads such as emplaced explosives. During these dislocations, fine particles are released from the damaged zones and can create unwanted inertial erosion and piping through the transverse cracks. These processes are equally critical to the overall stability of the dam. We present numerical results related to the problem of the fluid flow, transport, and filtration of particulates from damaged zones between the concrete sections of a gravity dam and the embankment wraparound sections. The model solves simultaneously the flow, attachment, and washout of fine particles within a wraparound heterogeneous porous media. We used a state-of-the-art finite element method with adaptive mesh refinement to capture 1) the interface between water dense with fines and clear water, and 2) the non-linearity of the free surface itself. A few scenarios of sediment entrapment in the filter layers of a gravity dam were considered. Several parameterizations of the filtration model and constitutive laws of soil behavior were also investigated. Through these analyses, we concluded that the attachment kinetic isotherm is the key function of the model. More parametric studies need to be conducted to assess the sensitivity of the kinetic isotherm parameters on the overall stability of the embankment. These kinetic parameters can be obtained, for example, through numerical micro- and meso-scale studies. It is worth mentioning that the current model, for the more realistic non-linear kinetic isotherms, has predicted a self-rehabilitation of the breached core with retention of 50% of the mobilized fines using a very conservative filtration length. A more realistic value should exceed the assumed one, resulting in a retention exceeding 50%. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under

  4. 40 CFR 721.10277 - Single-walled and multi-walled carbon nanotubes (generic) (P-10-40).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... not intended to undergo further processing except for mechanical processing. (2) The significant new... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Single-walled and multi-walled carbon... Significant New Uses for Specific Chemical Substances § 721.10277 Single-walled and multi-walled...

  5. Enzymes and other agents that enhance cell wall extensibility

    NASA Technical Reports Server (NTRS)

    Cosgrove, D. J.

    1999-01-01

    Polysaccharides and proteins are secreted to the inner surface of the growing cell wall, where they assemble into a network that is mechanically strong, yet remains extensible until the cells cease growth. This review focuses on the agents that directly or indirectly enhance the extensibility properties of growing walls. The properties of expansins, endoglucanases, and xyloglucan transglycosylases are reviewed and their postulated roles in modulating wall extensibility are evaluated. A summary model for wall extension is presented, in which expansin is a primary agent of wall extension, whereas endoglucanases, xyloglucan endotransglycosylase, and other enzymes that alter wall structure act secondarily to modulate expansin action.

  6. Vascular MR segmentation: wall and plaque

    NASA Astrophysics Data System (ADS)

    Yang, Fuxing; Holzapfel, Gerhard; Schulze-Bauer, Christian; Stollberger, Rudolf; Thedens, Daniel; Bolinger, Lizann; Stolpen, Alan; Sonka, Milan

    2003-05-01

    Cardiovascular events frequently result from local rupture of vulnerable atherosclerotic plaque. Non-invasive assessment of plaque vulnerability is needed to allow institution of preventive measures before heart attack or stroke occur. A computerized method for segmentation of arterial wall layers and plaque from high-resolution volumetric MR images is reported. The method uses dynamic programming to detect optimal borders in each MRI frame. The accuracy of the results was tested in 62 T1-weighted MR images from 6 vessel specimens in comparison to borders manually determined by an expert observer. The mean signed border positioning errors for the lumen, internal elastic lamina, and external elastic lamina borders were -0.12+/-0.14 mm, 0.04+/-0.12mm, and -0.15+/-0.13 mm, respectively. The presented wall layer segmentation approach is one of the first steps towards non-invasive assessment of plaque vulnerability in atherosclerotic subjects.

  7. Two- and three-dimensional model and wall data from a flexible-walled transonic test section

    NASA Technical Reports Server (NTRS)

    Goodyer, M. J.; Cook, I. D.

    1984-01-01

    Both two- and three-dimensional model testing is being carried out in the transonic flexible-walled wind tunnel test section. The test section has flexible top and bottom walls with rigid sidewalls. Interference is eliminated by adjustments based on data taken at walls in two dimensional models. Cast-7 data will illustrate agreement between various flexible-walled tunnels. In three-dimensional models interference cannot be eliminated but wall adjustments can control and relieve the principal sources of wall-induced errors. Estimates of magnitudes of the control which may be exercised on flow by movement of one wall jack are presented. A wall control algorithm (still in analytic development stage) based on use of this data is described. Brief examples of control of wall-induced perturbations in region of model are given.

  8. Plant and algal cell walls: diversity and functionality

    PubMed Central

    Popper, Zoë A.; Ralet, Marie-Christine; Domozych, David S.

    2014-01-01

    Background Although plants and many algae (e.g. the Phaeophyceae, brown, and Rhodophyceae, red) are only very distantly related they are united in their possession of carbohydrate-rich cell walls, which are of integral importance being involved in many physiological processes. Furthermore, wall components have applications within food, fuel, pharmaceuticals, fibres (e.g. for textiles and paper) and building materials and have long been an active topic of research. As shown in the 27 papers in this Special Issue, as the major deposit of photosynthetically fixed carbon, and therefore energy investment, cell walls are of undisputed importance to the organisms that possess them, the photosynthetic eukaryotes (plants and algae). The complexities of cell wall components along with their interactions with the biotic and abiotic environment are becoming increasingly revealed. Scope The importance of plant and algal cell walls and their individual components to the function and survival of the organism, and for a number of industrial applications, are illustrated by the breadth of topics covered in this issue, which includes papers concentrating on various plants and algae, developmental stages, organs, cell wall components, and techniques. Although we acknowledge that there are many alternative ways in which the papers could be categorized (and many would fit within several topics), we have organized them as follows: (1) cell wall biosynthesis and remodelling, (2) cell wall diversity, and (3) application of new technologies to cell walls. Finally, we will consider future directions within plant cell wall research. Expansion of the industrial uses of cell walls and potentially novel uses of cell wall components are both avenues likely to direct future research activities. Fundamentally, it is the continued progression from characterization (structure, metabolism, properties and localization) of individual cell wall components through to defining their roles in almost every

  9. Large eddy simulation of smooth-wall, transitional and fully rough-wall channel flow

    NASA Astrophysics Data System (ADS)

    Saito, Namiko; Pullin, Dale I.; Inoue, Michio

    2012-07-01

    Large eddy simulation (LES) is reported for both smooth and rough-wall channel flows at resolutions for which the roughness is subgrid. The stretched vortex, subgrid-scale model is combined with an existing wall-model that calculates the local friction velocity dynamically while providing a Dirichlet-like slip velocity at a slightly raised wall. This wall model is presently extended to include the effects of subgrid wall roughness by the incorporation of the Hama's roughness function Δ U^+(k_{sinfty }^+) that depends on some geometric roughness height ks∞ scaled in inner variables. Presently Colebrook's empirical roughness function is used but the model can utilize any given function of an arbitrary number of inner-scaled, roughness length parameters. This approach requires no change to the interior LES and can handle both smooth and rough walls. The LES is applied to fully turbulent, smooth, and rough-wall channel flow in both the transitional and fully rough regimes. Both roughness and Reynolds number effects are captured for Reynolds numbers Reb based on the bulk flow speed in the range 104-1010 with the equivalent Reτ, based on the wall-drag velocity uτ varying from 650 to 108. Results include a Moody-like diagram for the friction factor f = f(Reb, ɛ), ɛ = ks∞/δ, mean velocity profiles, and turbulence statistics. In the fully rough regime, at sufficiently large Reb, the mean velocity profiles show collapse in outer variables onto a roughness modified, universal, velocity-deficit profile. Outer-flow stream-wise turbulence intensities scale well with uτ for both smooth and rough-wall flow, showing a log-like profile. The infinite Reynolds number limits of both smooth and rough-wall flows are explored. An assumption that, for smooth-wall flow, the turbulence intensities scaled on uτ are bounded above by the sum of a logarithmic profile plus a finite function across the whole channel suggests that the infinite Reb limit is inviscid slip flow without

  10. Effect of lower bainite/martensite/retained austenite triplex microstructure on the mechanical properties of a low-carbon steel with quenching and partitioning process

    NASA Astrophysics Data System (ADS)

    Li, Wan-song; Gao, Hong-ye; Li, Zhong-yi; Nakashima, Hideharu; Hata, Satoshi; Tian, Wen-huai

    2016-03-01

    We present a study concerning Fe-0.176C-1.31Si-1.58Mn-0.26Al-0.3Cr (wt%) steel subjected to a quenching and partitioning (Q&P) process. The results of scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and tensile tests demonstrate that the microstructures primarily consist of lath martensite, retained austenite, lower bainite (LB), and a small amount of tempered martensite; moreover, few twin austenite grains were observed. In the microstructure, three types of retained austenite with different sizes and morphologies were observed: blocky retained austenite (~300 nm in width), film-like retained austenite (80-120 nm in width), and ultra- fine film-like retained austenite (30-40 nm in width). Because of the effect of the retained austenite/martensite/LB triplex microstructure, the specimens prepared using different quenching temperatures exhibit high ultimate tensile strength and yield strength. Furthermore, the strength effect of LB can partially counteract the decreasing strength effect of martensite. The formation of LB substantially reduces the amount of retained austenite. Analyses of the retained austenite and the amount of blocky retained austenite indicated that the carbon content is critical to the total elongation of Q&P steel.

  11. Retained Hawthorn fragment in a child's foot complicated by infection: diagnosis and excision aided by localization with ultrasound.

    PubMed

    Harris, Edwin J

    2010-01-01

    Puncture wounds in children are very common and often result in foreign body retention. Organic materials in the form of plant thorns present problems in identification and localization because they are not visualized with plain radiographs. A case of a 10-year-old girl with a small piece of retained hawthorn is presented. Correct diagnosis and treatment were delayed because of misinterpretation of magnetic resonance image studies. Ultrasound ultimately located the foreign body, and assisted in its excision. Plant thorns may be toxic and produce an intense local inflammatory response. In the case described in this article, deep infection caused by Enterobacter cloacae and Pantoea agglomerans was associated with the retained thorn. The small size of the foreign body, misinterpretation of diagnostic images, and the deep infection highlight the challenges that can be encountered by physicians managing puncture wounds in children. PMID:19962326

  12. Hot wire production of single-wall and multi-wall carbon nanotubes

    DOEpatents

    Dillon, Anne C.; Mahan, Archie H.; Alleman, Jeffrey L.

    2010-10-26

    Apparatus (210) for producing a multi-wall carbon nanotube (213) may comprise a process chamber (216), a furnace (217) operatively associated with the process chamber (216), and at least one filament (218) positioned within the process chamber (216). At least one power supply (220) operatively associated with the at least one filament (218) heats the at least one filament (218) to a process temperature. A gaseous carbon precursor material (214) operatively associated with the process chamber (216) provides carbon for forming the multi-wall carbon nanotube (213). A metal catalyst material (224) operatively associated with the process (216) catalyzes the formation of the multi-wall carbon nanotube (213).

  13. Retained folates in the rat.

    PubMed Central

    Barford, P A; Staff, R J; Blair, J A

    1977-01-01

    The retention of radioactivity after doses of 14C- and 3H-labelled folic acid is described. Radioactivity was retained in liver, kidney and gut of rats for some time after administration of the dose. The retained radioactivity could not be displaced by large doses of unlabelled folic acid or unlabelled 5-methyltetrahydrofolate. 14C- and 3H-labbelled folates showed similar chromatographic behaviour onion-exchange chromatography to 5-methyltetrahydrofolate, and on ion-exchange and gel-permeation chromatography to synthetic pteroylhepta-gamma-glutamate. PMID:883955

  14. Retaining Teacher Talent: Convergence and Contradictions in Teachers' Perceptions of Policy Reform Ideas. A Retaining Teacher Talent Report from Learning Point Associates and Public Agenda

    ERIC Educational Resources Information Center

    Coggshall, Jane G.; Ott, Amber

    2010-01-01

    As a new decade dawns, teachers stand at the center of a policy vortex. They serve as the primary focus of one of the Obama administration's four pillars of educational reform--effective teachers and leaders. Educational reformers of all stripes have focused tremendous energy on thinking of ways to identify effective teachers and in turn recruit,…

  15. Lateral patellar facetectomy and medial reefing in patients with lateral facet syndrome after patellar-retaining total knee arthroplasty.

    PubMed

    Pagenstert, Geert; Seelhoff, Juliane; Henninger, Heath B; Wirtz, Dieter C; Valderrabano, Victor; Barg, Alexej

    2014-11-01

    We analyzed clinical outcomes of partial lateral patellar facetectomy and medial reefing in patients with lateral patellar facet syndrome with painful patellar-retaining total knee arthroplasty. 34 patients were followed for a mean of 40 months. All 34 patients were matched with those having secondary patellar resurfacing without facetectomy. Both groups experienced significant pain relief and range of motion improvement. The facetectomy group had higher Kujala scores than those in patellar resurfacing group. Patients with facetectomy had significantly less pain postoperatively. There were significant differences in postoperative lateral patellar tilt and congruency angle in both groups. The mid-term results for LPF with medial reefing are promising to resolve pain in patients with lateral patellar facet syndrome in patellar-retaining TKA. Therapeutic level III (retrospective comparative study). PMID:25070901

  16. Lock 5 View west of wing walls and chamber ...

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

    Lock 5 - View west of wing walls and chamber with gate pockets visible. Note two small notches in brick at lower portion of wing walls - Savannah & Ogeechee Barge Canal, Between Ogeechee & Savannah Rivers, Savannah, Chatham County, GA

  17. View of intersection with west wall of north wing and ...

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

    View of intersection with west wall of north wing and north wall of west wing; camera facing southeast. - Mare Island Naval Shipyard, Marine Prison, Suisun Avenue, west side between Mesa Road & San Pablo, Vallejo, Solano County, CA

  18. Detail of northeast wing wall and guiderail. The section of ...

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

    Detail of northeast wing wall and guiderail. The section of the wing wall in the foreground is a historic extension of this element. - Chester County Bridge No. 225, Spanning Tweed Creek at Hopewell Road, Oxford, Chester County, PA

  19. Motion of a viscous fluid and a wall in the presence of a stationary wall

    NASA Astrophysics Data System (ADS)

    Sennitskii, V. L.

    2016-03-01

    The problem of damping motion of a hydromechanical system consisting of a viscous fluid and its bounding rigid walls is solved. A condition under which there is an abrupt deceleration of the hydromechanical system is determined.

  20. Fluorescent tags to explore cell wall structure and dynamics

    PubMed Central

    Gonneau, Martine; Höfte, Herman; Vernhettes, Samantha

    2012-01-01

    Plant cell walls are highly dynamic and heterogeneous structures, which vary between cell types, growth stages but also between microdomains within a single cell wall. In this review, we summarize the imaging techniques using fluorescent tags that are currently being used and which should in the coming years revolutionize our understanding of the dynamics of cell wall architecture and the cellular processes involved in the synthesis of cell wall components. PMID:22783266

  1. Site preparation for switchgrass intercropping in loblolly pine plantations reduces retained trees and snags, but maintains downed woody debris

    USGS Publications Warehouse

    Loman, Zachary G.; Riffell, Samuel K.; Miller, Darrin A.; Martin, James A.; Vilella, Francisco

    2013-01-01

    Within young pine (Pinus spp.) plantations, coarse woody debris (CWD) and green trees are important habitat structures that may be impacted by the production of biofuel feedstock. Therefore, we compared site preparation procedures associated with switchgrass (Panicum virgatum L.) intercropping to determine effects on CWD and green trees in stands (n = 24) site-prepared for intercropping, with switchgrass only, or pine plantation in Mississippi, USA. Following site preparation, CWD dispersal or volume did not differ between intercropped and control stands. Intercropped stands had significantly fewer retained trees and snags. Switchgrass monocultures had no retained trees or piles and significantly fewer pieces and less volume of CWD than the other treatments. Our results suggest switchgrass intercropping may provide similar habitat quality to traditional pine plantations for wildlife species using these areas in the year following disturbance, but may provide a less suitable habitat for species that require snags. However, the relationship between snag reduction and wildlife population response in an intercropped setting is not clear and should be further investigated. Regardless, if retaining snags is a desired outcome, site preparation for switchgrass should be restricted to the interbed area where it will be cultivated as opposed to extensive debris removal from the entire site.                   

  2. The Bond Strength of Resin Bonded Bridge Retainers to Abutments of Differing Proportions of Enamel and Composite.

    PubMed

    Durey, Kathryn; Nattress, Brian

    2015-03-01

    Four groups of specimens were constructed using bovine enamel and composite resin. After a period of ageing, the specimens were roughened and acid etched before they were cemented to air abraded base metal alloy beams with a universal resin cement. After further ageing, tensile peel testing was carried out using a Universal Testing Machine. The force required to produce failure increased as the amount of composite resin on the bonding surface of the abutment increased. This difference reached statistical significance (p < 0.5) when the abutments contained > 50% composite. The mode of failure was mixed on the majority of retainers. Within the limitations of the study, findings suggest that RBB retainers can be cemented to abutments restored with composite resin without a reduction in bond strength. PMID:26415336

  3. Response to Intervention and Retention for Children with Specific Learning Disabilities: Differences in Academic Achievement between Retained and Non-Retained Students

    ERIC Educational Resources Information Center

    Keller-Margulis, Milena; Gischlar, Karen

    2014-01-01

    Research indicates that the practice of grade-level retention may have negative effects on students; nevertheless it is often used in practice for students who fail to meet academic standards. In contrast to retention, response to intervention (RtI) is a sound practice that is based on a preventive framework and utilizes differentiated instruction…

  4. Flood control embankments contribute to the improvement of the health status of children in rural Bangladesh.

    PubMed

    Myaux, J A; Ali, M; Chakraborty, J; de Francisco, A

    1997-01-01

    Every year, Bangladesh experiences major floods that inundate about one-third of the country. Therefore, flood control projects that comprise earthen dikes and irrigation/drainage systems are built along the major rivers to protect the people living in low-lying areas, stabilize the river banks and improve agricultural productivity. However, the adverse effects of these projects are regularly emphasized, such as environmental degradation and reduction of fishing supplies. The Demographic Surveillance System of the International Centre for Diarrhoeal Diseases Research, Bangladesh (ICDDR,B) was used to assess the effect of a flood control programme on the mortality of 0-4-year-old children residing in the Matlab study area. Adjusted mortality rates were used in comparing four adjacent child populations residing either inside or outside a flood-control embankment and according to the type of health services provided in this area. Between the periods 1983-86 and 1989-92, the crude child mortality in the total study area decreased by 37%, from 185.9 per 1000 live births to 117.9 per 1000 live births. Following the construction of the embankment, death rates outside were up to 29% higher in 1-4-year-old children and 9% higher for 0-4-year age group compared to the flood-protected area (P < 0.001). Simultaneously, in the same study area, health interventions contributed to a 40% reduction in mortality among children less than 5 years of age in all causes of deaths (P < 0.001). Migration patterns and the effect of distances to the hospital are discussed. PMID:9509625

  5. Electrical transmission line diametrical retainer

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David; Dahlgren, Scott; Sneddon, Cameron; Briscoe, Michael; Fox, Joe

    2004-12-14

    The invention is a mechanism for retaining an electrical transmission line. In one embodiment of the invention it is a system for retaining an electrical transmission line within down hole components. In accordance with one aspect of the invention, the system includes a plurality of downhole components, such as sections of pipe in a drill string. The system also includes a coaxial cable running between the first and second end of a drill pipe, the coaxial cable having a conductive tube and a conductive core within it. The invention allows the electrical transmission line to with stand the tension and compression of drill pipe during routine drilling cycles.

  6. 30 CFR 56.3130 - Wall, bank, and slope stability.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Wall, bank, and slope stability. 56.3130... Mining Methods § 56.3130 Wall, bank, and slope stability. Mining methods shall be used that will maintain wall, bank, and slope stability in places where persons work or travel in performing their...

  7. 30 CFR 56.3130 - Wall, bank, and slope stability.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Wall, bank, and slope stability. 56.3130... Mining Methods § 56.3130 Wall, bank, and slope stability. Mining methods shall be used that will maintain wall, bank, and slope stability in places where persons work or travel in performing their...

  8. 30 CFR 56.3130 - Wall, bank, and slope stability.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Wall, bank, and slope stability. 56.3130... Mining Methods § 56.3130 Wall, bank, and slope stability. Mining methods shall be used that will maintain wall, bank, and slope stability in places where persons work or travel in performing their...

  9. 30 CFR 56.3130 - Wall, bank, and slope stability.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Wall, bank, and slope stability. 56.3130... Mining Methods § 56.3130 Wall, bank, and slope stability. Mining methods shall be used that will maintain wall, bank, and slope stability in places where persons work or travel in performing their...

  10. 30 CFR 56.3130 - Wall, bank, and slope stability.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Wall, bank, and slope stability. 56.3130... Mining Methods § 56.3130 Wall, bank, and slope stability. Mining methods shall be used that will maintain wall, bank, and slope stability in places where persons work or travel in performing their...

  11. Management of a Fractured Multiunit Maxillary Implant-Supported Fixed Prosthesis with Stripped Abutment Screws Using a Hybrid Cement-Retained and Screw-Retained Design: A 5-Year Follow-Up Clinical Report.

    PubMed

    Al Amri, Mohammad D

    2016-06-01

    Fracture and loosening of implant-supported prostheses (ISPs) are complications encountered in routine dental practice. In the present report, management of a fractured maxillary full-arch cement-retained (CR) fixed dental prosthesis supported by six implants is presented. Due to stripped screws, complications were encountered that prevented the retrieval of two of the six abutment screws, which was managed by using a hybrid retention approach, whereby a single full-arch CR and screw-retained (SR) ISP was used. The techniques used to successfully retrieve four of the abutment screws are described. The final retention design involved a combination of three CR and three SR restorations, which offers the advantages of both retention designs. PMID:26713868

  12. Evolutionary conservation of a molecular machinery for export and expression of mRNAs with retained introns

    PubMed Central

    Wang, Baomin; Rekosh, David

    2015-01-01

    Intron retention is one of the least studied forms of alternative splicing. Through the use of retrovirus and other model systems, it was established many years ago that mRNAs with retained introns are subject to restriction both at the level of nucleocytoplasmic export and cytoplasmic expression. It was also demonstrated that specific cis-acting elements in the mRNA could serve to bypass these restrictions. Here we show that one of these elements, the constitutive transport element (CTE), first identified in the retrovirus MPMV and subsequently in the human NXF1 gene, is a highly conserved element. Using GERP analysis, CTEs with strong primary sequence homology, predicted to display identical secondary structure, were identified in NXF genes from >30 mammalian species. CTEs were also identified in the predicted NXF1 genes of zebrafish and coelacanths. The CTE from the zebrafish NXF1 was shown to function efficiently to achieve expression of mRNA with a retained intron in human cells in conjunction with zebrafish Nxf1 and cofactor Nxt proteins. This demonstrates that all essential functional components for expression of mRNA with retained introns have been conserved from fish to man. PMID:25605961

  13. CHARACTERIZATION OF TANK 18F WALL AND SCALE SAMPLES

    SciTech Connect

    Hay, Michael; Click, Damon; Diprete, c.; Diprete, David

    2010-03-01

    Samples from the wall of Tank 18F were obtained to determine the associated source term using a special wall sampling device. Two wall samples and a scale sample were obtained and characterized at the Savannah River National Laboratory (SRNL). All the analyses of the Tank 18F wall and scale samples met the targeted detection limits. The upper wall samples show {approx}2X to 6X higher concentrations for U, Pu, and Np on an activity per surface area basis than the lower wall samples. On an activity per mass basis, the upper and lower wall samples show similar compositions for U and Pu. The Np activity is still {approx}2.5X higher in the upper wall sample on a per mass basis. The scale sample contains 2-3X higher concentrations of U, Pu, and Sr-90 than the wall samples on an activity per mass basis. The plutonium isotopics differ for all three wall samples (upper, lower, and scale samples). The Pu-238 appears to increase as a proportion of total plutonium as you move up the tank wall from the lowest sample (scale sample) to the upper wall sample. The elemental composition of the scale sample appears similar to other F-Area PUREX sludge compositions. The composition of the scale sample is markedly different than the material on the floor of Tank 18F. However, the scale sample shows elevated Mg and Ca concentrations relative to typical PUREX sludge as do the floor samples.

  14. Effect of different mucosa thickness and resiliency on stress distribution of implant-retained overdentures-2D FEA.

    PubMed

    Barão, Valentim Adelino Ricardo; Assunção, Wirley Gonçalves; Tabata, Lucas Fernando; de Sousa, Edson Antonio Capello; Rocha, Eduardo Passos

    2008-11-01

    The study aimed to evaluate the effect of different mucosa thickness and resiliency on stress distribution of implant-retained overdentures using a two-dimensional finite element analysis. Models were used in order to simulate two situations. In group A, model represented an edentulous mandible supporting an overdenture retained by two-splinted-implants connected with bar-clip system while in group B, model simulated an edentulous mandible supporting an overdenture retained by two-splinted-implants connected with bar-clip system associated with two-distally placed o'ring system. In each group, mucosa assumed three characteristics of thickness (1, 3 and 5 mm) in the resiliencies: hard, resilient and soft, respectively. Evaluation was performed on Ansys software. Group A showed higher stress values regardless of the mucosa characteristics. Overall, stress decreased at the supporting tissues as mucosa thickness and resiliency increased. Regarding supporting tissues, cortical bone showed the highest stress values. The use of bar-clip attachment system with distally placed o'ring attachment design optimized the stress distribution. PMID:18783845

  15. The Wall of Death: Newtons, Nerves, and Nausea.

    ERIC Educational Resources Information Center

    Charoenkul, Niran; Wheeler, David; Dejasvanong, Chanwit

    1999-01-01

    Describes an experience as passengers in a car that traveled around the "Wall of Death" during a country fair show. Explains the physics behind riding vehicles around the Wall. Finds that cars don't need to lean, motorcycles must lean, and people should lean to avoid nausea while traveling around the Wall. (WRM)

  16. Skyrmion domain wall collision and domain wall-gated skyrmion logic

    NASA Astrophysics Data System (ADS)

    Xing, Xiangjun; Pong, Philip W. T.; Zhou, Yan

    2016-08-01

    Skyrmions and domain walls are significant spin textures of great technological relevance to magnetic memory and logic applications, where they can be used as carriers of information. The unique topology of skyrmions makes them display emergent dynamical properties as compared with domain walls. Some studies have demonstrated that the two topologically inequivalent magnetic objects could be interconverted by using cleverly designed geometric structures. Here, we numerically address the skyrmion domain wall collision in a magnetic racetrack by introducing relative motion between the two objects based on a specially designed junction. An electric current serves as the driving force that moves a skyrmion toward a trapped domain wall pair. We see different types of collision dynamics depending on the driving parameters. Most importantly, the modulation of skyrmion transport using domain walls is realized in this system, allowing a set of domain wall-gated logical NOT, NAND, and NOR gates to be constructed. This work provides a skyrmion-based spin-logic architecture that is fully compatible with racetrack memories.

  17. Brick walls and AdS/CFT

    NASA Astrophysics Data System (ADS)

    Kay, Bernard S.; Ortíz, L.

    2014-05-01

    We discuss the relationship between the bulk-boundary correspondence in Rehren's algebraic holography (and in other `fixed-background', QFT-based, approaches to holography) and in mainstream string-theoretic `Maldacena AdS/CFT'. Especially, we contrast the understanding of black-hole entropy from the point of view of QFT in curved spacetime—in the framework of 't Hooft's `brick wall' model—with the understanding based on Maldacena AdS/CFT. We show that the brick-wall modification of a Klein-Gordon field in the Hartle-Hawking-Israel state on dimensional Schwarzschild AdS has a well-defined boundary limit with the same temperature and entropy as the brick-wall-modified bulk theory. One of our main purposes is to point out a close connection, for general AdS/CFT situations, between the puzzle raised by Arnsdorf and Smolin regarding the relationship between Rehren's algebraic holography and mainstream AdS/CFT and the puzzle embodied in the `complementarity principle' proposed by Mukohyama and Israel in their work on the brick-wall approach to black hole entropy. Working on the assumption that similar results will hold for bulk QFT other than the Klein-Gordon field and for Schwarzschild AdS in other dimensions, and recalling the first author's proposed resolution to the Mukohyama-Israel puzzle based on his `matter-gravity entanglement hypothesis', we argue that, in Maldacena AdS/CFT, the algebra of the boundary CFT is isomorphic only to a proper subalgebra of the bulk algebra, albeit (at non-zero temperature) the (GNS) Hilbert spaces of bulk and boundary theories are still the `same'—the total bulk state being pure, while the boundary state is mixed (thermal). We also argue from the finiteness of its boundary (and hence, on our assumptions, also bulk) entropy at finite temperature, that the Rehren dual of the Maldacena boundary CFT cannot itself be a QFT and must, instead, presumably be something like a string theory.

  18. 42 CFR 137.100 - May a Self-Governance Tribe retain and spend interest earned on any funds paid under a compact or...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false May a Self-Governance Tribe retain and spend... OF HEALTH AND HUMAN SERVICES TRIBAL SELF-GOVERNANCE Funding Interest Or Other Income on Transfers § 137.100 May a Self-Governance Tribe retain and spend interest earned on any funds paid under a...

  19. 42 CFR 137.100 - May a Self-Governance Tribe retain and spend interest earned on any funds paid under a compact or...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false May a Self-Governance Tribe retain and spend... OF HEALTH AND HUMAN SERVICES TRIBAL SELF-GOVERNANCE Funding Interest Or Other Income on Transfers § 137.100 May a Self-Governance Tribe retain and spend interest earned on any funds paid under a...

  20. 42 CFR 137.100 - May a Self-Governance Tribe retain and spend interest earned on any funds paid under a compact or...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false May a Self-Governance Tribe retain and spend... OF HEALTH AND HUMAN SERVICES TRIBAL SELF-GOVERNANCE Funding Interest Or Other Income on Transfers § 137.100 May a Self-Governance Tribe retain and spend interest earned on any funds paid under a...