Science.gov

Sample records for river bend station

  1. 78 FR 50454 - Entergy Operations, Inc., River Bend Station, Unit 1

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-19

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Entergy Operations, Inc., River Bend Station, Unit 1 AGENCY: Nuclear Regulatory Commission. ACTION...-47, issued to Entergy Operations, Inc. (the licensee), for operation of the River Bend Station,...

  2. 78 FR 53482 - Entergy Operations, Inc., River Bend Station, Unit 1; Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ... environment (78 FR 50454; August 19, 2013). This exemption is effective upon issuance. Dated at Rockville... COMMISSION Entergy Operations, Inc., River Bend Station, Unit 1; Exemption 1.0 Background Entergy Operations... operation of the River Bend Station, Unit 1 (RBS). The license provides, among other things, that...

  3. 75 FR 61219 - Entergy Operations, Inc.; River Bend Station, Unit 1; Environmental Assessment and Finding of No...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-04

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Entergy Operations, Inc.; River Bend Station, Unit 1; Environmental Assessment and Finding of No Significant Impact The U.S. Nuclear Regulatory Commission (NRC) is considering changes to the Emergency Plan, pursuant to 10 CFR 50.54, ``Conditions...

  4. Divisional isolation using electro-pneumatic controls at Entergy`s River Bend Power Station

    SciTech Connect

    Finkenaur, R.G. III

    1995-10-01

    In 1991, The Service Water System at River Bend Nuclear Plant was modified from an open flume system to a closed system. Closing the system presented some unique challenges to the Design Engineering staff with respect to compliance to The Nuclear Regulatory Commission`s Regulatory Guide 1.75 (RG 1.75). This paper will explain the mechanical and electrical changes made to the plant in order to maintain compliance with the applicable regulations and the reasoning for the design decisions involved.

  5. Flood characteristics of the Buffalo River at Tyler Bend, Arkansas

    USGS Publications Warehouse

    Neely, Braxtel L.

    1987-01-01

    The Buffalo River is located in the Ozark Mountains in north-central Arkansas. Tyler Bend is on the Buffalo River about 1.5 miles upstream from U.S. Highway 65. The National Park Service is developing several recreational park sites along this scenic river. The magnitude, frequency, duration and velocities of floods are primary factors needed for establishing guidelines for developing facilities and managing park sites. The Park Service plans to develop park facilities at Tyler Bend and needs flood information at this site. This report provides information on the 100-, 75-, 50-, 30-, 20-, 10-, and 5-year floods on the Buffalo River at Tyler Bend. It was prepared by the U.S. Geological Survey in cooperation with the National Park Service and is based on data collected during the December 1982 flood, gaging station data for the Buffalo River near St. Joe, Arkansas and a Statewide flood-frequency report. (Lantz-PTT)

  6. Advantages of customer/supplier involvement in the upgrade of River Bend`s IST program

    SciTech Connect

    Womack, R.L.; Addison, J.A.

    1996-12-01

    At River Bend Station, IST testing had problems. Operations could not perform the test with the required repeatability; engineering could not reliably trend test data to detect degradation; licensing was heavily burdened with regulatory concerns; and maintenance could not do preventative maintenance because of poor prediction of system health status. Using Energy`s Total Quality principles, it was determined that the causes were: lack of ownership, inadequate test equipment usage, lack of adequate procedures, and lack of program maintenance. After identifying the customers and suppliers of the IST program data, Energy management put together an upgrade team to address these concerns. These customers and suppliers made up the IST upgrade team. The team`s mission was to supply River Bend with a reliable, functional, industry correct and user friendly IST program. The IST program in place went through a verification process that identified and corrected over 400 individual program discrepancies. Over 200 components were identified for improved testing methods. An IST basis document was developed. The operations department was trained on ASME Section XI testing. All IST tests have been simplified and shortened, due to heavy involvement by operations in the procedure development process. This significantly reduced testing time, resulting in lower cost, less dose and greater system availability.

  7. HYDRODYNAMICS AND SEDIMENT TRANSPORT IN LOWER MISSISSIPPI RIVER MEANDER BENDS (LOUISIANA): IMPLICATIONS FOR LARGE SEDIMENT DIVERSIONS

    NASA Astrophysics Data System (ADS)

    Allison, M. A.; McCorquodale, A.; Meselhe, E. A.

    2009-12-01

    Field data collection and numerical modeling is being conducted in the lower Mississippi River in the region of a meander bend at Myrtle Grove, LA (river km 96 above Head of Passes) in support of a proposed large water and sediment diversion (1,130-2,830 cms) for coastal wetland restoration. Field studies in October 2008, April and May 2009, at discharges ranging from 11,000-21,000 cms, examined the role of bend dynamics on sediment transport through this reach relative to control sites further downriver and USGS monitoring stations upriver. Suspended loads and grain size character measured by ADCP (velocities and backscatter), isokinetic point sampler (P-63), and optical sensors (LISST, OBS, transmissometer) indicate that during the rising-to-high discharge phase, sand lifting off from the downstream edge of the lateral bar upriver of the bend augments that carried from further upriver, and is entrained in the upper 10-25m of the water column. This excess suspended sand is advected around the bend before concentrations are reduced to background levels over the lateral bar downstream of the bend. Bedload transport rates measured by repeat swath bathymetric mapping of migrating dunes are comparable upstream of the bend, downstream, and in the control sites. However, no bedforms are observed in the bend thalweg (up to 60 m deep) supporting the dominance of suspended sand transport in the bend. Both 1D (HEC-RAS and HEC6-T) and 3D (Flow3D) numerical hydrodynamic and sediment transport modeling is underway to simulate this process and the large-scale eddy present in the bend that generates upriver transport along the inside of the meander bend at all observed discharges. Our preliminary results suggest that the outside of meander bends might be an appropriate site for sediment diversions that draw near-surface water from this sediment-rich layer.

  8. Sharp bends associated with deep scours in a tropical river: The river Mahakam (East Kalimantan, Indonesia)

    NASA Astrophysics Data System (ADS)

    Vermeulen, B.; Hoitink, A. J. F.; Berkum, S. W.; Hidayat, H.

    2014-07-01

    Autogenic scouring in sharp river bends has received ample attention in laboratory and modeling studies. These studies have significantly advanced our understanding of how flow processes are influenced by strong curvature and how they affect the bathymetry. Here we present a 300 km reach of the Mahakam River in Indonesia, which features several sharp bends (W/R > 0.5), providing a unique field data set to validate existing knowledge on sharp bends. Scour depths were found to strongly exceed what can be expected based on existing understanding of sharp bends and are highly correlated with curvature. A comprehensive stream reconnaissance was carried out to compare the occurrence of sharp bends and deep scours with lateral bank migration. Histograms of the occurrence of erosive, stable, advancing, and bar-type banks as a function of curvature quantify the switch from a mildly curved bend regime to a sharp bend regime. In mild bends, outer banks erode and inner banks advance. In sharp bends the erosion pattern inverts. Outer banks stabilize or advance, while inner banks erode. In sharply curved river bends, bars occur near the outer banks that become less erosive for higher curvatures. Inner banks become more erosive for higher curvatures but nevertheless accommodate the larger portion of exposed bars. No relation was found between the land cover adjacent to the river and the occurrence of sharp bends. Soil processes may play a crucial role in the formation of sharp bends, which is inferred from iron and manganese concretions observed in the riverbanks, indicating ferric horizons and early stages of the formation of plinthic horizons. Historical topographic maps show the planform activity of the river is low, which may relate to the scour holes slowing down planimetric development.

  9. Analytical determination of coupled bending-torsion vibrations of cantilever beams by means of station functions

    NASA Technical Reports Server (NTRS)

    Mendelson, Alexander; Gendler, Selwyn

    1951-01-01

    A method based on the concept of station functions is presented for calculating the modes and the frequencies of nonuniform cantilever beams vibrating in torsion, bending, and coupled bending-torsion motion. The method combines some of the advantages of the Rayleigh-Ritz and Stodola methods, in that a continuous loading function for the beam is used, with the advantages of the influence-coefficient method, in that the continuous loading function is obtained in terms of the displacements of a finite number of stations along the beam.

  10. 13. VIEW FROM POTOMAC RIVER BRIDGE PLATFORM WEST TOWARDS STATION. ...

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

    13. VIEW FROM POTOMAC RIVER BRIDGE PLATFORM WEST TOWARDS STATION. HARPERS FERRY DEPOT IS ON LEFT, NORTH TRACK WAITING STATION IS ON RIGHT. - Baltimore & Ohio Railroad, Harpers Ferry Station, Potomac Street, Harpers Ferry, Jefferson County, WV

  11. VIEW, LOOKING NORTHWEST, OF MIANUS RIVER PUMP STATION AND MIANUS ...

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

    VIEW, LOOKING NORTHWEST, OF MIANUS RIVER PUMP STATION AND MIANUS RIVER DAM. AT THE LEFT END OF THE DAM IS A FISH LADDER INSTALLED IN 1993 - New York, New Haven & Hartford Railroad, Mianus River Pumping Station, River Road & Boston Post Road, Greenwich, Fairfield County, CT

  12. Autogenic Scour and Channel Widening in Sharp Bends of the River Mahakam

    NASA Astrophysics Data System (ADS)

    Hoitink, T.; Vermeulen, B.; van Berkum, S.; Hidayat, H.; Labeur, R. J.

    2014-12-01

    Field evidence of the River Mahakam reveals autogenic scour and channel widening in a series of sharp bends. An integral analysis of a 300 km reach of the river is presented, including a comprehensive survey of the river banks, delineation of the river corridor from radar observations, Large Eddy Simulations of observed flow patterns, and a geometric analysis of planform and depth information. Scour depths strongly exceed what can be expected based on existing understanding of sharp bends, and are highly correlated with curvature. Histograms of the occurrence of erosive, stable, advancing, and bar-type banks as a function of curvature quantify the switch from a mildly curved bend regime to a sharp bend regime. In mild bends, outer banks erode and inner banks advance. In sharp bends the erosion pattern inverts. Outer banks stabilize or advance, while inner banks erode. In sharply curved river bends, bars occur near the outer banks that become less erosive for higher curvatures. Inner banks become more erosive for higher curvatures, but nevertheless accommodate the larger portion of exposed bars. Soil processes may play a crucial role in the formation of sharp bends, which is inferred from iron and manganese concretions observed in the riverbanks, indicating ferric horizons and early stages of the formation of plinthic horizons. Historical topographic maps show the planform activity of the river is low, which may relate to the scours slowing down planimetric development. The occurrence of exceptionally deep scours is attributed to downflow near the scour exceeding 12 cm/s, increasing the bed shear stress. The downflow, in turn, is explained from the cross-sectional area increase, which is shown to be important in generating adverse surface gradients driving flow recirculation in the Large Eddy Simulations. Strong secondary flow distorts the vertical pressure distribution that is no longer hydrostatic. The downflow advects longitudinal momentum, moving the core of the

  13. Composition of Age-0 Fish Assemblages in the Apalachicola River, River Styx, and Battle Bend, Florida

    USGS Publications Warehouse

    Walsh, Stephen J.; Buttermore, Elissa N.; Burgess, O. Towns; Pine, William E., III

    2009-01-01

    Light traps were used to sample the age-0 year class of fish communities in the Apalachicola River and associated floodplain water bodies of River Styx and Battle Bend, Florida, in 2006-2007. A total of 629 light traps were deployed during the spring and early summer months (341 between March 15 and June 6, 2006; 288 between March 9 and July 3, 2007). For combined years, 13.8 percent of traps were empty and a total of 20,813 age-0 fish were captured representing at least 40 taxa of 29 genera and 16 families. Trap catches were dominated by relatively few species, with the most abundant groups represented by cyprinids, centrarchids, percids, and catostomids. Six taxa accounted for about 80 percent of all fish collected: Micropterus spp. (28.9 percent), Notropis texanus (28.9 percent), Lepomis macrochirus (7.9 percent), Carpiodes cyprinus (6.2 percent), Cyprinidae sp. (4.6 percent), and Minytrema melanops (4.2 percent). Based on chronological appearance in light traps and catch-per-unit effort, including data from previous years of sampling, peak spawning periods for most species occurred between early March and mid-June. A complementary telemetry study of pre-reproductive adults of select target species (Micropterus spp., Lepomis spp., and M. melanops) revealed distinct patterns of habitat use, with some individual fish exclusively utilizing mainstem river habitat or floodplain habitat during spawning and post-spawning periods, and other individuals migrating between habitats. A comparison of light-trap catches between a pre-enhancement, high-water year (2003) and post-enhancement, low-water year (2007) for the oxbow at Battle Bend revealed some difference in community composition, with slightly greater values of diversity and evenness indices in 2007. Two dominant species, Lepomis macrochirus and Micropterus salmoides, were substantially greater in relative abundance among all age-0 fish collected in 2007 in comparison to 2003. Excavation of sediments at the mouth

  14. INTERIOR VIEW OF MIANUS RIVER PUMP STATION LOOKING SOUTHEAST. THE ...

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

    INTERIOR VIEW OF MIANUS RIVER PUMP STATION LOOKING SOUTHEAST. THE CYLINDRICAL TANKS ON THE RIGHT SIDE OF THE PHOTOGRAPH ARE SAND-GRAVEL FILTERS. THE DIESEL POWERED PUMPS LOCATED IN THE CENTER LEFT FOREGOUND SUPPLIED FRESH WATER THROUGH A 16" LINE TO THE POWER PLANT BOILERS LOCATED ONE MILE SOUTH OF THE PUMP STATION - New York, New Haven & Hartford Railroad, Mianus River Pumping Station, River Road & Boston Post Road, Greenwich, Fairfield County, CT

  15. 15. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN (MODEL ...

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

    15. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN (MODEL SCALE: 1' = 26'). - Waterways Experiment Station, Hydraulics Laboratory, Halls Ferry Road, 2 miles south of I-20, Vicksburg, Warren County, MS

  16. 17. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN. ENGINEERS ...

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

    17. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN. ENGINEERS EXAMINING MODEL PUMPS, VIEW FROM MODEL BED. - Waterways Experiment Station, Hydraulics Laboratory, Halls Ferry Road, 2 miles south of I-20, Vicksburg, Warren County, MS

  17. 16. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN. MECHANICAL ...

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

    16. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN. MECHANICAL AND HYDRAULIC ENGINEERS EXAMINING MODEL PUMPS. - Waterways Experiment Station, Hydraulics Laboratory, Halls Ferry Road, 2 miles south of I-20, Vicksburg, Warren County, MS

  18. 19. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN. ELECTRONICS ...

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

    19. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN. ELECTRONICS ENGINEER AT DATA COLLECTION COMPUTER ROOM. - Waterways Experiment Station, Hydraulics Laboratory, Halls Ferry Road, 2 miles south of I-20, Vicksburg, Warren County, MS

  19. 18. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN. CIVIL ...

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

    18. YAZOO BACKWATER PUMPING STATION MODEL, YAZOO RIVER BASIN. CIVIL ENGINEERING AIDE AT CONTROL BOX. - Waterways Experiment Station, Hydraulics Laboratory, Halls Ferry Road, 2 miles south of I-20, Vicksburg, Warren County, MS

  20. An integrated approach to investigate the reach-averaged bend scale dynamics of large meandering rivers

    NASA Astrophysics Data System (ADS)

    Monegaglia, Federico; Henshaw, Alex; Zolezzi, Guido; Tubino, Marco

    2016-04-01

    Planform development of evolving meander bends is a beautiful and complex dynamic phenomenon, controlled by the interplay among hydrodynamics, sediments and floodplain characteristics. In the past decades, morphodynamic models of river meandering have provided a thorough understanding of the unit physical processes interacting at the reach scale during meander planform evolution. On the other hand, recent years have seen advances in satellite geosciences able to provide data with increasing resolution and earth coverage, which are becoming an important tool for studying and managing river systems. Analysis of the planform development of meandering rivers through Landsat satellite imagery have been provided in very recent works. Methodologies for the objective and automatic extraction of key river development metrics from multi-temporal satellite images have been proposed though often limited to the extraction of channel centerlines, and not always able to yield quantitative data on channel width, migration rates and bed morphology. Overcoming such gap would make a major step forward to integrate morphodynamic theories, models and real-world data for an increased understanding of meandering river dynamics. In order to fulfill such gaps, a novel automatic procedure for extracting and analyzing the topography and planform dynamics of meandering rivers through time from satellite images is implemented. A robust algorithm able to compute channel centerline in complex contexts such as the presence of channel bifurcations and anabranching structures is used. As a case study, the procedure is applied to the Landsat database for a reach of the well-known case of Rio Beni, a large, suspended load dominated, tropical meandering river flowing through the Bolivian Amazon Basin. The reach-averaged evolution of single bends along Rio Beni over a 30 years period is analyzed, in terms of bend amplification rates computed according to the local centerline migration rate. A

  1. Local sorting, bend curvature, and particle mobility in meandering gravel bed rivers

    NASA Astrophysics Data System (ADS)

    Clayton, Jordan A.

    2010-02-01

    Hydraulic, grain scale sorting of mixed bed sediment influences the mobility of grains in discrete areas of river channels. To assess this effect, local values of surface grain size sorting were compared with measurements of bed load at corresponding locations in a bend of the Colorado River in Rocky Mountain National Park (RMNP), and the distribution of local Shields stress through the reach was derived from a two-dimensional flow model. With decreasing degrees of local sorting, the relative mobility of the fine- and coarse-size fractions of the load appeared to decrease and increase, respectively. Furthermore, back-calculated critical Shields stress values for sediment entrainment decreased with values of local sorting, particularly for the upstream portion of the reach where particles were more poorly sorted and coarse grains had higher relative exposure. To evaluate the pervasiveness of these and other patterns of sorting in gravel rivers, detailed field measurements of channel topography and surface grain size (317 pebble counts) were obtained for seven additional reaches of differing curvature (radius of curvature/width from 1 to 28) near the headwaters of the Colorado and Fall rivers in RMNP. Moderately curved and tight bends (radius of curvature/width ≤ 7) were significantly better sorted than comparatively straight reaches. Values of local sorting decreased with distance downstream for the majority of curved channels, reflecting a reduction in the standard deviation of surface grain sizes toward the lower end of the reach; this effect increased slightly with bend sharpness.

  2. Finite Amplitude Bars in Mixed Bedrock-Alluvial River Channel Bends

    NASA Astrophysics Data System (ADS)

    Nelson, P. A.; Seminara, G.; Bolla Pittaluga, M.

    2012-12-01

    A common and well-understood feature of alluvial rivers is the tendency for channel curvature to induce bed deformations, producing a point bar on the inner bank and scour on the outer bank. However, for mixed bedrock-alluvial rivers, where the amount of sediment supplied from upstream is less than the local sediment transport capacity, our understanding of this phenomenon is less clear. Our goal here is to develop a theory capable of answering the question: How does channel curvature influence sediment deposition and bedrock exposure in mixed bedrock-alluvial rivers? We have developed a nonlinear asymptotic theory of fully developed flow and bed topography in a wide channel of constant curvature to describe finite-amplitude perturbations of bottom topography, subject to an inerodible bedrock layer. The flow field is evaluated at leading order of approximation as a slowly varying sequence of locally uniform flows, slightly perturbed by a weak curvature-induced secondary flow. Using the constraint of constant fluid discharge, we calculate an analytical solution for the cross-sectional profile of flow depth and bed topography, and we determine the average slope in the bend necessary to transport the sediment supplied from a straight, alluvial, upstream reach. Both fully-alluvial bends and bends with partial bedrock exposure are shown to require a larger average slope than a straight upstream reach; the relative slope increase is much larger for partially alluviated bends. Curvature has a strong effect on the characteristics of the point bars in mixed bedrock-alluvial channels, with higher curvature bends exhibiting bars of larger amplitude and more bedrock exposure through the cross section. Differences in the relative roughness of sediment and bedrock have a smaller, secondary effect on point bar characteristics. This theory can potentially be extended to the not fully developed case, and should ultimately lead to an improved understanding of the formation of

  3. Incision of the Yangtze River at the First Bend Determined by Three-Nuclide Burial Dating

    NASA Astrophysics Data System (ADS)

    McPhillips, D. F.; Hoke, G. D.; Rood, D. H.; Bierman, P. R.

    2015-12-01

    On the southeast margin of the Tibetan Plateau, the evolution of the Yangtze River and its major tributaries has become an important source of data for investigating geodynamics. In particular, the timing of river incision is frequently interpreted as a proxy for the timing of surface uplift in the absence of structural evidence. We investigate the timing of the incision of the gorge at the First Bend using cosmogenic nuclide burial dating of coarse, quartz sediments from caves. Sediments were deposited when the caves were near river level and subsequently abandoned as the river incised. To resolve burial ages >5 Ma, we measured the radionuclides 10Be and 26Al, and the stable nuclide 21Ne. Results from 4 caves show that 26Al and 10Be concentrations are an order of magnitude lower in abandoned cave samples than in a river-level cave sample where deposition is active (10Be: 1.3x104 and 3.4x105 at/g). In contrast, 26Al/10Be ratios in all caves are ≥6.2 and indistinguishable within error. 21Ne concentrations range from 2.1x106 to 7.8x106 at/g. The results are consistent with an old age for the abandoned cave deposits, such that most of the radionuclides initially present have decayed and the concentrations that we measure today are the result of millions of years of exposure to muons. We solve for burial ages, taking into account in situ muogenic production, and find that the majority of the gorge (1 km) was likely incised between ~12 and 9 Ma. The results also require that the rate of river incision declined after the gorge was cut below the lowest elevation cave at 9 Ma. Inverse modeling of published low-temperature thermochronology (Ouimet et al., 2010) supports our burial age results. River capture near the First Bend, which likely integrated the modern Yangtze, likely occurred prior to the mid-Miocene incision of the gorge. In view of the geographic position of the First Bend—just downslope from the southeast margin of the Plateau—it is difficult to explain

  4. 50. VIEW OF CENTRAL CONTROL STATION AND VISITOR CENTER/RIVER SIDES ...

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

    50. VIEW OF CENTRAL CONTROL STATION AND VISITOR CENTER/RIVER SIDES (Visitor Center Building constructed after field negatives were taken and numbered.) - Mississippi River 9-Foot Channel Project, Lock & Dam No. 11, Upper Mississippi River, Dubuque, Dubuque County, IA

  5. Role of river bends for the formation and evolution of channel bedforms: Combined field studies and numerical modeling from the tidally influenced zones of the Yellow River, China, and Mississippi River, USA.

    NASA Astrophysics Data System (ADS)

    Ma, H.; Nittrouer, J. A.; Moodie, A.; Calson, B.; Parker, G.

    2015-12-01

    River bedforms represent the unstable interface between fluid flow and the granular channel bed, and these features play an important role for modifying flow resistance and sediment transport rates, and thus influencing river morphology. Although widely observed in natural rivers, bedforms are difficult to measure quantitatively and are rarely connected to other fluvial morphological processes. This study presents high-resolution channel bathymetric data from the tidally influenced, lowermost Yellow River, China, collected using a multibeam swath profiler. Repeat surveys were conducted over rising and flood discharge conditions, which is the first such kind of survey in Yellow River. The bathymetry data show that for all water discharges, a flat bed, devoid of a thalweg or dunes, persists within straight-reach segments near the bends of the Yellow River, despite the bed consisting of fine sand. Interestingly, in bend segments, the channel deepens, and linear dunes develop. Moreover, as the water discharge increases over time, the edge of dune field contained in the bend segments propagates into the adjacent upstream and downstream straight-reach segments. In contrasting case study, Nittrouer et al. (2008) reported persistent dune field in the straight reaches of the tidally influenced Mississippi River; however these dunes disappear in neighboring river bends. Based on the two cases of the Yellow and Mississippi Rivers, which have fundamentally different conditions of water-to-sediment discharge ratios, the threshold condition of bedform formation and stability are evaluated, and connected to local conditions of river bend morphology. This work improves the understanding of the co-evolution of bedforms and flow conditions in river bends, which are intertwined and important morphological processes that affect fluvial-deltaic sediment transport dynamics. In addition, the straight-bend structure is a basic element of river morphology, and so the results of this study

  6. Experimental salinity alleviation at Malaga Bend of the Pecos River, Eddy County, New Mexico

    USGS Publications Warehouse

    Havens, John S.; Wilkins, D.W.

    1979-01-01

    Upward-leaking brine, from a confined aquifer at the base of the Rustler Formation, mixes with fresher water in a shallow aquifer , resulting in discharge to the Pecos River in southern Eddy County, New Mexico, of about 0.5 cubic feet per second of saturated brine. Pumping brine from the aquifer at a rate greater than 0.5 cubic feet per second lowered the potentiometric head in the confined aquifer. From July 22, 1963, through December 1968, approximately 3,878 acre-feet of brine had been pumped into the Northeast Depression. The depression leaked brine to the Pecos River. Water downgradient of the depression increased in specific conductance ranging from 1,500 to 99,400 milligrams per liter chloride and water levels near the depression increased over 3 feet from 1963 to 1968. For water years 1952-63, the Pecos River gained about 240 tons per day of chloride in the reach from Malaga gaging station to Pierce Canyon Crossing. The average chloride gain to the Pecos River from July 1963 to August 1966 was 167 tons per day; the 1967-68 gain increased to 256 tons per day after a major flood in August 1966. (USGS)

  7. Southwest region solar pond study for three sites: Tularosa Basin, Malaga Bend, and Canadian River

    SciTech Connect

    Boegli, W.J.; Dahl, M.M.; Remmers, H.E.

    1984-08-01

    In the study, the Bureau of Reclamation investigated the technical and economic feasibility of using solar salt-gradient ponds to generate power and to produce freshwater in Bureau projects at three sites--the Canadian River at Logan, New Mexico; Malaga Bend on the Pecos River near Carlsbad, New Mexico; and the Tularosa Basin in the vicinity of Alamogordo, New Mexico. The ponds would be used to generate electric power that could be integrated with the Bureau's power grid or used in combination with thermal energy from the ponds to power commercially available desalination systems to produce freshwater. Results of the economic analysis, which concentrated primarily on the Tularosa Basin site, showed that solar-pond-generated intermediate load power would cost between 62 and 90 mills/kWh and between 52 and 83 mills/kWh for baseload power. This results in benefit-cost ratios of approximately 2.0 and 1.3 for intermediate and baseload, respectively, when compared to similar facilities powered by fossil fuels. The cost savings are even more pronounced when comparing the two (solar versus fossil fuel) as a source of power for conventional distillation and membrane-type desalination systems.

  8. Flow structure caused by a local cross-sectional area increase and curvature in a sharp river bend

    NASA Astrophysics Data System (ADS)

    Vermeulen, B.; Hoitink, A. J. F.; Labeur, R. J.

    2015-09-01

    Horizontal flow recirculation is often observed in sharp river bends, causing a complex three-dimensional flow structure with large implications for the morphological and planimetric development of meanders. Several field observations in small-scale systems show that sharp bends are often found in association with a strong increase in cross-sectional area, the deposition of outer bank benches, and reattachment bars near the inner bank. Recent studies show that these bends can also occur in large-scale systems. In this study, we present field measurements of a sharp bend in the Mahakam River, East Kalimantan, Indonesia. The cross-sectional area increases by a factor of 3 compared with the reach-averaged cross-sectional area. Along a river reach of about 150 km, cross-sectional area correlates strongly with curvature. The field measurements are analyzed together with the results from numerical simulation with a three-dimensional finite element model, which yields a comprehensive view of the intricate flow structure. In turn, the model is used to validate a new equation that captures the water surface topography dependence on cross-sectional area variation and curvature. The results show the importance of the increase in cross-sectional area in the development of horizontal recirculation. Vertical acceleration of the flow into the scour causes the pressure to deviate from a hydrostatic pressure distribution. Strong downflow (up to 12 cm s-1) advects longitudinal momentum toward the bed, causing the flow to concentrate in the lower part of the cross section. This increases the velocity magnitude throughout the cross section, which is expected to maintain the large scour depth found in several bends along the Mahakam River.

  9. Base Flow (1966-2005) and Streamflow Gain and Loss (2006) of the Brazos River, McLennan County to Fort Bend County, Texas

    USGS Publications Warehouse

    Turco, Michael J.; East, Jeffery W.; Milburn, Matthew S.

    2007-01-01

    During 2006?07, the U.S. Geological Survey (USGS), in cooperation with the Texas Water Development Board, did a study to quantify historical (water years 1966?2005) base flow and streamflow gains and losses from two streamflow-measuring surveys (March and August 2006) in the Brazos River from McLennan County to Fort Bend County, Texas. The Brazos River is hydraulically connected to the Brazos River alluvium aquifer, which in turn is hydraulically connected to several underlying aquifers, the outcrops of which occur in laterally adjacent layers generally parallel to the coast (major aquifers, Carrizo-Wilcox and Gulf Coast, and minor aquifers, Queen City, Sparta, and Yegua-Jackson). Hydrograph separation was done using the USGS computer program Hydrograph Separation and Analysis with historical streamflow from 10 USGS gaging stations, three on the Brazos River and seven on selected tributaries to the Brazos River. Streamflow data for computation of gains and losses were collected in March 2006 from 36 sites on the Brazos River and 19 sites on 19 tributaries to the Brazos River; and in August 2006 from 28 sites on the Brazos River and 16 sites on tributaries. Hydrograph separation and associated analyses indicate an appreciable increase in base flow as a percentage of streamflow in the reach of the Brazos River that crosses the outcrops of the Carrizo-Wilcox, Queen City, Sparta, and Yegua-Jackson aquifers compared to that in the adjacent upstream reach (on average from about 43 percent to about 60 percent). No increase in base flow as a percentage of streamflow in the reach of the Brazos River crossing the Gulf Coast aquifer compared to that in the adjacent upstream reach was indicated. Streamflow gains and losses computed for March 2006 for 35 reaches defined by pairs of sites on the Brazos River indicated that five reaches were verifiably gaining streamflow (computed gain exceeded potential flow measurement error) and none were verifiably losing streamflow. Four of

  10. Population trends, bend use relative to available habitat and within-river-bend habitat use of eight indicator species of Missouri and Lower Kansas River benthic fishes: 15 years after baseline assessment

    USGS Publications Warehouse

    Wildhaber, Mark L.; Yang, Wen-Hsi; Arab, Ali

    2016-01-01

    A baseline assessment of the Missouri River fish community and species-specific habitat use patterns conducted from 1996 to 1998 provided the first comprehensive analysis of Missouri River benthic fish population trends and habitat use in the Missouri and Lower Yellowstone rivers, exclusive of reservoirs, and provided the foundation for the present Pallid Sturgeon Population Assessment Program (PSPAP). Data used in such studies are frequently zero inflated. To address this issue, the zero-inflated Poisson (ZIP) model was applied. This follow-up study is based on PSPAP data collected up to 15 years later along with new understanding of how habitat characteristics among and within bends affect habitat use of fish species targeted by PSPAP, including pallid sturgeon. This work demonstrated that a large-scale, large-river, PSPAP-type monitoring program can be an effective tool for assessing population trends and habitat usage of large-river fish species. Using multiple gears, PSPAP was effective in monitoring shovelnose and pallid sturgeons, sicklefin, shoal and sturgeon chubs, sand shiner, blue sucker and sauger. For all species, the relationship between environmental variables and relative abundance differed, somewhat, among river segments suggesting the importance of the overall conditions of Upper and Middle Missouri River and Lower Missouri and Kansas rivers on the habitat usage patterns exhibited. Shoal and sicklefin chubs exhibited many similar habitat usage patterns; blue sucker and shovelnose sturgeon also shared similar responses. For pallid sturgeon, the primary focus of PSPAP, relative abundance tended to increase in Upper and Middle Missouri River paralleling stocking efforts, whereas no evidence of an increasing relative abundance was found in the Lower Missouri River despite stocking.

  11. From meander bend to oxbow lake: flow, channel morphology and sedimentology of an evolving chute cutoff on the Wabash River, IL-IN

    NASA Astrophysics Data System (ADS)

    Zinger, J. A.; Rhoads, B. L.; Best, J. L.; Johnson, K.

    2012-12-01

    Chute channels develop on meandering rivers in a wide variety of environments, and in many cases result in bend cutoff and formation of an oxbow lake. During the transition from active meander bend to oxbow lake, the chute channel and original bend create a paired bifurcation-confluence unit. Here, we present field documentation of the evolving flow structure within a recent chute cutoff on the Wabash River, IL-IN, focusing on the bifurcation located on the upstream limb of the original bend. Previous studies indicate that this is the location of greatest sedimentation rates prior to complete plugging of the bend (e.g. Shields & Abt, 1989). We seek to isolate the fundamental processes causing rapid sedimentation in the upstream limb of the bend, using repeated hydroacoustic measurements of bed elevation and three-dimensional flow velocity at several key cross-sections. We also employ differential GPS surveys of channel banklines, analysis of aerial photographs and sampling of sediment on exposed bars at low flow, to aid interpretations of the cross-sectional data. This paper will detail the co-evolution of flow structure and channel morphology at this site and examine the coherent patterns of erosion and deposition responsible for oxbow lake formation. Reference: Shields, FD; Abt, SR (1989). Sediment deposition in cutoff meander bends and implications for effective management. Regulated Rivers: Research & Management 4, 381-396.

  12. Structure and geological history of the Lepanto-Cervantes releasing bend on the Abra river fault, Luzon Central Cordillera, Philippines

    NASA Astrophysics Data System (ADS)

    Ringenbach, Jean Claude; Stephan, Jean François; Maleterre, Philippe; Bellon, Herve

    1990-11-01

    The Luzon Central Cordillera corresponds to the uplifted and tectonized magmatic arc associated with the Manila Trench subduction zone. It is cut into N-S trending strips by the horsetail-like overprint of the Philippine strike-slip fault. The median branch, herein named the Abra River Fault, splits away to the west from the Dalton Fault and runs north-northwestward for 240 km through the range. Trending N150E in its southern part, it undergoes a sinistral bend in the Lepanto-Cervantes area, and then strikes N-S, makes a second bend and runs north-northeast up to the northwestern tip of the island. In the bend area, the compartment east of the fault has subsided, forming a narrow strip along the southern Lepanto segment and a wider trough parallel to the fault which stretches 25 km from Cervantes. The basement of the strip is position dependent, corresponding either to the Oligo-Miocene arc succession (volcanoclastic sediments and dioritic intrusive), or to the pre-Late Eocene ophiolitic basement of the arc. In the Lepanto area, two volcanic formations are preserved: the oldest one, the Malaya Formation is latest Miocene in age (6.1 ± 0.3 and 5.7 ± 0.28 Ma by K/Ar) and represents the infill of the trough, the youngest, the Mount Pudso volcanics, is Holocene in age (0.5 Ma by K/Ar). The Cervantes trough contains a thick (reaching 1700 m) volcanoclastic sequence dated as latest Miocene-Early Pliocene (3.7 ± 0.18-6.2 ± 0.28 Ma by K/Ar (the Malaya Formation). On the western and southern sides, the Abra River Fault separates the very deformed infill from the strongly uplifted pre-Late Miocene basement. On the east side, the basement, whose elevation increases gradually eastward, is disconformably overlain by the Mio-Pliocene sequence. To the north, the trough is slightly deformed. The structural analysis of the Lepanto-Cervantes strip, together with the local and regional geological and geochronological data, allow us to propose a three-stage history. The first

  13. Geologic and hydrogeologic information for a geodatabase for the Brazos River Alluvium Aquifer, Bosque County to Fort Bend County, Texas

    USGS Publications Warehouse

    Shah, Sachin D.; Houston, Natalie A.

    2007-01-01

    During July-October 2006, the U.S. Geological Survey (USGS), in cooperation with the Texas Water Development Board (TWDB), developed geologic and hydrogeologic information for a geodatabase for use in development of a Groundwater Availability Model (GAM) of the Brazos River alluvium aquifer along the Brazos River from Bosque County to Fort Bend County, Texas. The report provides geologic and hydrogeologic information for a study area that encompasses the Brazos River alluvium aquifer, a 1/2-mile-wide lateral buffer surrounding the aquifer, and the rocks immediately underlying the aquifer. The geodatabase involves use of a thematic approach to create layers of feature data using a geographic information system. Feature classes represent the various types of data that are keyed to spatial location and related to one another within the geodatabase. The 1/2-mile-wide buffer surrounding the aquifer was applied to include data from wells constructed primarily in alluvium but outside the boundary of the Brazos River alluvium aquifer. A 1/2- by 1/2-mile grid was generated on the study area to facilitate uniform distribution of data for eventual input into the GAM. Data were compiled primarily from drillers and borehole geophysical logs from government agencies and universities, hydrogeologic sections and maps from published reports, and agency files. The geodatabase contains 450 points with geologic data and 280 points with hydrogeologic data.

  14. Influence of Channel Morphology on Flow Hydraulics in a Compound Meander Bend of the Lower Brazos River, Texas

    NASA Astrophysics Data System (ADS)

    Hales, B. U.; Guneralp, I.; Filippi, A. M.

    2013-12-01

    At a meander-bend scale, process-form interactions between channel morphology and flow hydraulics generate unique features called geomorphic units, such as pools, sediment bars, and backwater regions. Geomorphic units play an important role as distinct habitats for aquatic species. In this study, we investigate channel morphology and flow structure of an incised meander bend on the lower Brazos River, Texas, to inform aquatic habitat assessment. The bend represents the characteristics of sand-bed and high-amplitude meandering rivers and contains a localized bank-protection structure along its cutbank. We examine: 1) the spatial characteristics of channel morphology (i.e., geomorphic units); 2) spatial characteristics of flow hydraulics in relation to geomorphic units at low- (Q1), medium- (Q2), and high- (Q3) discharge conditions; and 3) the influence of channel morphology on flow hydraulics within this meander bend. We utilize bathymetric and hydraulic surveys conducted using Acoustic Doppler Current Profiler (ADCP) and simultaneously collected bed-sediment samples. To characterize channel morphology, we use a digital terrain model (DTM) of the bend that we generate by fusing our bathymetric data and an airborne interferometric synthetic aperture radar (InSAR)-derived DTM. We examine flow hydraulics by performing quasi 3-D hydraulic modeling. Results show that channel morphology has a strong influence on the spatial distribution of hydraulic parameters, including water depth, flow velocities, Froude number, and helix strength. At Q1, the emergent mid-channel bar forces flow divergence/convergence and acts as a macro-roughness structure. High flow velocity concentrates in the deeper and narrower sub-channel along the cutbank side. At Q2, the location of the mid-channel bar shifts toward the point bar, forming a new chute sub-channel. Highest flow velocities are still concentrated in the permanent sub-channel along the cutbank, but shift downstream toward the exit

  15. 78 FR 75386 - Entergy Operations, Inc.; Combined License Application for River Bend Station Unit 3, Exemption...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-11

    ... Register on November 3, 2011 (76 FR 72560). Part 50, Appendix E, Section I.5 gives those COL applicants.... NRC's Agencywide Documents Access and Management System (ADAMS): You may access publicly available documents online in the NRC Library at http://www.nrc.gov/reading-rm/adams.html . To begin the...

  16. 33 CFR 165.554 - Security Zone; Three Mile Island Generating Station, Susquehanna River, Dauphin County...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security Zone; Three Mile Island... Areas Fifth Coast Guard District § 165.554 Security Zone; Three Mile Island Generating Station... waters of the Susquehanna River in the vicinity of the Three Mile Island Generating Station bounded by...

  17. 33 CFR 165.554 - Security Zone; Three Mile Island Generating Station, Susquehanna River, Dauphin County...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Security Zone; Three Mile Island... Areas Fifth Coast Guard District § 165.554 Security Zone; Three Mile Island Generating Station... waters of the Susquehanna River in the vicinity of the Three Mile Island Generating Station bounded by...

  18. 33 CFR 165.554 - Security Zone; Three Mile Island Generating Station, Susquehanna River, Dauphin County...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Security Zone; Three Mile Island... Areas Fifth Coast Guard District § 165.554 Security Zone; Three Mile Island Generating Station... waters of the Susquehanna River in the vicinity of the Three Mile Island Generating Station bounded by...

  19. 33 CFR 165.554 - Security Zone; Three Mile Island Generating Station, Susquehanna River, Dauphin County...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Security Zone; Three Mile Island... Areas Fifth Coast Guard District § 165.554 Security Zone; Three Mile Island Generating Station... waters of the Susquehanna River in the vicinity of the Three Mile Island Generating Station bounded by...

  20. 33 CFR 165.554 - Security Zone; Three Mile Island Generating Station, Susquehanna River, Dauphin County...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Security Zone; Three Mile Island... Areas Fifth Coast Guard District § 165.554 Security Zone; Three Mile Island Generating Station... waters of the Susquehanna River in the vicinity of the Three Mile Island Generating Station bounded by...

  1. Toward global mapping of river discharge using satellite images and at-many-stations hydraulic geometry.

    PubMed

    Gleason, Colin J; Smith, Laurence C

    2014-04-01

    Rivers provide critical water supply for many human societies and ecosystems, yet global knowledge of their flow rates is poor. We show that useful estimates of absolute river discharge (in cubic meters per second) may be derived solely from satellite images, with no ground-based or a priori information whatsoever. The approach works owing to discovery of a characteristic scaling law uniquely fundamental to natural rivers, here termed a river's at-many-stations hydraulic geometry. A first demonstration using Landsat Thematic Mapper images over three rivers in the United States, Canada, and China yields absolute discharges agreeing to within 20-30% of traditional in situ gauging station measurements and good tracking of flow changes over time. Within such accuracies, the door appears open for quantifying river resources globally with repeat imaging, both retroactively and henceforth into the future, with strong implications for water resource management, food security, ecosystem studies, flood forecasting, and geopolitics. PMID:24639551

  2. River Discharge Estimation Solely from Satellite Imagery and at-Many-Stations Hydraulic Geometry (AMHG)

    NASA Astrophysics Data System (ADS)

    Gleason, C. J.; Smith, L. C.; Lee, J.

    2014-12-01

    Knowledge of river discharge is critically important for water resource management, climate modeling, and improved understanding of the global water cycle, yet discharge is poorly known in much of the world. Remote sensing holds promise to mitigate this gap, yet many current approaches for quantitative retrievals of river discharge require in situ calibration or a priori knowledge of river hydraulics, limiting their utility in unmonitored regions. This talk demonstrates a novel remotely sensed discharge retrieval method that requires no prior knowledge and no ancillary data whatsoever. The approach is enabled by a newly discovered river-specific geomorphic scaling phenomenon, termed at-many-stations hydraulic geometry (AMHG), which holds that a river's paired at-a-station hydraulic geometry (AHG) parameters (a and b, c and f, k and m) are log-linearly related along a river. An associated AMHG discharge retrieval method uses only remotely sensed cross sectional river top width as an input to an unconstrained optimization of width-AHG via a genetic algorithm. Using the AMHG approach, we demonstrate successful retrieval of river discharge to within 20-30% of in situ gauge observations for the Mississippi, Athabasca, and Yangtze rivers. Expanding the method to 34 rivers globally, we find that the AMHG discharge retrieval method is sensitive to river morphology, cross sectional geometry, the quality of input widths, and genetic algorithm optimization parameters. These results suggest that the AMHG discharge retrieval method can meaningfully address global discharge knowledge gaps solely from repeat satellite imagery.

  3. Short-Term and Long-Term Variability of Antenna Position Due to Thermal Bending of Pillar Monument at Permanent GNSS Station

    NASA Astrophysics Data System (ADS)

    Gerhatova, Lubomira; Hefty, Jan; Spanik, Peter

    2016-06-01

    The variability of daily site coordinates at permanent GNSS station is a sum of many disturbing factors influencing the actual satellite observations, data processing, and bias modelling. In the paper are analysed possibilities of monitoring the instability of GNSS antenna pillar monument by the independent observations using the precise inclination sensor. Long-term series from three different types of pillars show specific features in amplitude and temporal evolution of monument bending. Correlations with daily temperature and/or solar radiation changes were proved.

  4. Toward global mapping of river discharge using satellite images and at-many-stations hydraulic geometry

    PubMed Central

    Gleason, Colin J.; Smith, Laurence C.

    2014-01-01

    Rivers provide critical water supply for many human societies and ecosystems, yet global knowledge of their flow rates is poor. We show that useful estimates of absolute river discharge (in cubic meters per second) may be derived solely from satellite images, with no ground-based or a priori information whatsoever. The approach works owing to discovery of a characteristic scaling law uniquely fundamental to natural rivers, here termed a river’s at-many-stations hydraulic geometry. A first demonstration using Landsat Thematic Mapper images over three rivers in the United States, Canada, and China yields absolute discharges agreeing to within 20–30% of traditional in situ gauging station measurements and good tracking of flow changes over time. Within such accuracies, the door appears open for quantifying river resources globally with repeat imaging, both retroactively and henceforth into the future, with strong implications for water resource management, food security, ecosystem studies, flood forecasting, and geopolitics. PMID:24639551

  5. Changing Station Coverage in the Upper Colorado River Basin: Is This a Problem?

    NASA Astrophysics Data System (ADS)

    McAfee, S. A.; Woodhouse, C. A.; Morino, K.; Pederson, G. T.

    2015-12-01

    Almost 40 million people living in the arid western U.S. depend on the Colorado River. The high demand, recent drought, and paleoclimatic studies documenting long, severe droughts have spurred numerous studies on the drivers of Colorado River flow. Understanding low-frequency variability and trends in a large and complex basin like the Upper Colorado (UCRB), which contributes the vast majority of Colorado River flow, requires long, high-spatial resolution climatological records. However, researchers sometimes find discrepancies between long climate data products and hydrological records. One explanation for such disparities is the composition of the climate data record. The National Center for Environmental Information's Master Station History Report (MSHR) documents significant changes in the number and spatial distribution of weather stations within the UCRB. These shifts are reflected in the basin-average station elevation, which has varied by over 300m since 1950 and by over 365m since 1875. Strong elevation and aspect controls on both temperature and precipitation combined with the high degree of variability in station location could drive trends in gridded products in the absence of real climatological trends, although differences in base data, spatial resolution and gridding algorithms can complicate comparisons. Yet limiting analysis to only those stations with long, consistent records is impractical and would be problematic as station density in the early part of the record was not sufficient to characterize the basin. Here we document changes in station coverage within the UCRB and identify the degree to which coverage may have influenced climatic trends.

  6. Analysis of fixed-station water-quality data in the Umpqua River basin, Oregon

    USGS Publications Warehouse

    Rinella, J.F.

    1986-01-01

    An appraisal of surface water quality in the Umpqua River basin was made using existing monthly data collected by the Oregon Department of Environmental Quality and the U.S. Geological Survey in cooperation with the Douglas County Water Resources Survey. This appraisal was limited to interpretation of instantaneous monthly water quality data collected in the Umpqua River basin from water years 1974 to 1983. These data were used to compare water quality conditions throughout the basin and to determine if data collected from the NASQAN (National Stream Quality Accounting network) station are representative of upstream basin conditions. In general, data collected at the NASQAN station represent a composite of water quality from the North and South Umpqua Rivers. These river basins account for 82 % of the NASQAN station drainage. Water quality concentrations, loads, yields, and trends were statistically described and related to point source effluent loads and basin characteristics including geohydrology, hydrology, population, land use, and water use. Available point-and nonpoint-source data provided minimal information for determining cause-effect relations and for explaining observed trends in water quality; however, the data did indicate that the largest effluent discharges are located in the South Umpqua River basin in the Roseburg-Winston area. Instantaneous and annual flow weighted levels of specific conductance, phosphorus, organic plus ammonia nitrogen, nitrite plus nitrate, and fecal coliform bacteria are generally highest in the South Umpqua River near Roseburg. These high levels generally occur during the summer months when river flow is extremely low relative to flow in the North Umpqua River. The North Umpqua River has among the lowest constituent concentrations observed in the basin. (Lantz-PTT)

  7. 33 CFR 165.552 - Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey. 165.552 Section 165.552 Navigation and Navigable... Coast Guard District § 165.552 Security Zone; Oyster Creek Generation Station, Forked River,...

  8. 33 CFR 165.552 - Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey. 165.552 Section 165.552 Navigation and Navigable... Coast Guard District § 165.552 Security Zone; Oyster Creek Generation Station, Forked River,...

  9. 33 CFR 165.552 - Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey. 165.552 Section 165.552 Navigation and Navigable... Coast Guard District § 165.552 Security Zone; Oyster Creek Generation Station, Forked River,...

  10. 33 CFR 165.552 - Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey. 165.552 Section 165.552 Navigation and Navigable... Coast Guard District § 165.552 Security Zone; Oyster Creek Generation Station, Forked River,...

  11. 33 CFR 165.552 - Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey. 165.552 Section 165.552 Navigation and Navigable... Coast Guard District § 165.552 Security Zone; Oyster Creek Generation Station, Forked River,...

  12. 33 CFR 334.155 - Severn River, Naval Station Annapolis, Small Boat Basin, Annapolis, MD; naval restricted area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Severn River, Naval Station Annapolis, Small Boat Basin, Annapolis, MD; naval restricted area. 334.155 Section 334.155 Navigation and... RESTRICTED AREA REGULATIONS § 334.155 Severn River, Naval Station Annapolis, Small Boat Basin, Annapolis,...

  13. 33 CFR 334.155 - Severn River, Naval Station Annapolis, Small Boat Basin, Annapolis, MD; naval restricted area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Severn River, Naval Station Annapolis, Small Boat Basin, Annapolis, MD; naval restricted area. 334.155 Section 334.155 Navigation and... RESTRICTED AREA REGULATIONS § 334.155 Severn River, Naval Station Annapolis, Small Boat Basin, Annapolis,...

  14. Field Bending Tests of Three Riparian Species Common to the Central Platte River: Resistance, Rigidity and Plant Streamlining

    NASA Astrophysics Data System (ADS)

    Thomas, R. E.; Bankhead, N. L.; Simon, A.

    2010-12-01

    The braided Platte River, central Nebraska, was described by the 19th Century wit Artemus Ward as being “a mile wide and an inch deep”. 150 years on, the upstream diversion and storage of water for agricultural, municipal and industrial uses has caused significant alteration of the hydrologic regime. As a result, sandbars have been progressively colonized by vegetation, leading to the formation of semi-permanent islands and the narrowing of braids by 30-90%. In response, a program was initiated early in 2007 to recreate habitat for endangered birds. One potential management strategy is to modify the hydrologic regime with the goal of removing vegetation and hence re-establishing a dynamic braided channel. An interdisciplinary approach has been adopted to evaluate the likelihood for successful implementation of such a strategy. In a companion paper, Bankhead et al. describe field tests conducted to quantify the forces necessary to uproot and/or break the stems and roots of four common riparian species. Herein, we describe field measurements of the behavior of reed canary grass, phragmites australis and cottonwood plants in response to being pulled horizontally at a known height above the ground. During the tests, the extent of plant bending in response to the applied force and the resistance to bending were monitored continuously. Furthermore, a novel approach employing time lapse photography and image processing was used to quantify associated changes in plant projected area. The mean stem diameter of reed canary grass plants was 3.21 ± 1.08 mm (μ ± σ, n = 69), that of phragmites australis plants was 6.05 ± 1.95 mm (n = 90), and that of cottonwood plants was 4.18 ± 3.59 mm (n = 76). The mean stem length of reed canary grass was 0.77 ± 0.35 m (n = 69), that of phragmites australis was 0.86 ± 0.64 m (n = 90), and that of cottonwoods was 0.55 ± 0.43 m (n = 76). The flexural rigidities (J) of cottonwoods were particularly sensitive to plant age: for 1 year

  15. Flow structure and channel morphodynamics of meander bend chute cutoffs: A case study of the Wabash River, USA

    NASA Astrophysics Data System (ADS)

    Zinger, Jessica A.; Rhoads, Bruce L.; Best, James L.; Johnson, Kevin K.

    2013-12-01

    paper documents the three-dimensional structure of flow and bed morphology of two developing chute cutoffs on a single meander bend on the lower Wabash River, USA, and relates the flow structure to patterns of morphologic change in the evolving cutoff channels. The upstream end of the cutoff channels is characterized by: (1) a zone of flow velocity reduction/stagnation and bar development in the main channel across from the cutoff entrance, (2) flow separation and bar development along the inner (left) bank of the cutoff channel immediately downstream from the cutoff entrance, and (3) helical motion and outward advection of flow momentum entering the cutoff channel, leading to erosion of the outer (right) bank of the cutoff channel. At the downstream end of the cutoff channels, the major hydrodynamic and morphologic features are: (1) flow stagnation along the bank of the main channel immediately upstream of the cutoff channel mouth, (2) convergence of flows from the cutoff and main channels, (3) helical motion of flow from the cutoff, (4) a zone of reduced velocity along the bank of the main channel immediately downstream from the cutoff channel mouth, and (5) development of a prominent bar complex that penetrates into the main channel and extends from the stagnation zone upstream to downstream of the cutoff mouth. These results provide the basis for a conceptual model of chute-cutoff dynamics in which the upstream and downstream ends of a cutoff channel are treated as a bifurcation and confluence, respectively.

  16. SURVEY OF FLUE GAS DESULFURIZATION SYSTEMS: GREEN RIVER STATION, KENTUCKY UTILITIES

    EPA Science Inventory

    The report gives results of a survey of the flue gas desulfurization (FGD) system retrofitted to Boilers 1, 2, and 3 at the Green River Station of Kentucky Utilities. The FGD system consists of one wet lime scrubber module designed to handle a maximum of 170 cu m/sec (360,000 afc...

  17. ALARA Overview System at Crystal River Unit 3 Nuclear Station.

    PubMed

    Kline, K B; Cope, W B

    1995-08-01

    During the Spring of 1994 the Health Physics Department at Florida Power Company used video and audio equipment to support remote health physics coverage for their Crystal River Unit 3 refueling outage (Refuel 9). The system consisted of eight cameras with audio interface linked to a control center located in a low-dose area. The system allowed health physics personnel to monitor steam generator and refueling activities with minimum exposure in high-dose areas, cutting by half the dose from the previous outage. B&W Nuclear Technologies provided complete setup, maintenance and tear-down, as well as assuming responsibilities for contaminated video and audio equipment. PMID:7622378

  18. Characteristics of suspended and streambed sediment within constructed chutes and the main channel at Upper Hamburg and Glovers Point Bends, Missouri River, Nebraska, 2008

    USGS Publications Warehouse

    Woodward, Brenda K.; Rus, David L.

    2011-01-01

    The U.S. Army Corps of Engineers, Omaha District, as part of the Missouri River Bank Stabilization and Navigation Mitigation Project, has constructed 17 off-channel chutes along the channelized Missouri River, downstream from Sioux City, Iowa, to increase habitat diversity. To better understand characteristics of suspended and streambed sediment within these constructed chutes, the U.S. Geological Survey investigated specific aspects of chute design and function in relation to sediment characteristics including: (1) effects of inlet structures; (2) changes occurring between the inlet and the outlet of a chute; (3) effects of chutes on sediment characteristics in the main channel; and (4) differences in chute dynamics between sampled chutes. Two chutes differing in design, location, and dynamics were studied, Upper Hamburg Bend near Nebraska City, Nebr., and Glovers Point Bend near Winnebago, Nebr. Each site was characterized using five or more sampling transects (two in the chute and three to four in the main channel) designed to bracket sediment exchanges between chutes and the main channel. A sixth transect was included at the Upper Hamburg Bend study site to account for the effects of a nontarget chute having its inlet midway between the inlet and outlet of the primary chute. Representative samples of suspended and streambed sediment were collected at each transect, along with measurements of turbidity and streamflow, between June and November 2008. Four sets of samples were collected at the Glovers Point Bend study site and five sample sets were collected from the Upper Hamburg Bend study site. Results from paired t-tests and standard t-tests indicated that the inlet structure design, passing inflow only from the top of the main-channel water column, reduced the supply of coarse-grained suspended sediment entering the chutes. Statistical comparisons did not indicate differences between the inlet and outlet of either chute; however, anecdotal evidence of recent

  19. NOx reduction through combustion optimization at PEPCO`s Potomac River Station

    SciTech Connect

    Cramer, D.S.; Williams, S.E.; Watkins, J.T.

    1995-06-01

    This paper describes the work done under EPRI Project RP 3383 at Potomac River Station to reduce NOx emissions by adjusting boiler controls. it details the method followed by PEPCO and Lehigh engineers to achieve a 35% reduction in average NOx emissions over a one-month extended test. Parameters that had the largest effect on NOx are discussed. A description of instruments installed to better monitor and control combustion is included.

  20. Bacteriological and Physicochemical Studies on Tigris River Near the Water Purification Stations within Baghdad Province

    PubMed Central

    Al-Bayatti, Khalid K.; Al-Arajy, Kadhum H.; Al-Nuaemy, Seba Hussain

    2012-01-01

    We studied the physical, chemical, and microbiological factors that influence drinking water quality processed from River Tigris, and of the three main drinking water purification stations located at different parts of Tigris River, along with evaluation of drinking water of Al-Shula region in Baghdad city. Water samples were taken monthly from December 2009 to September 2010. Physical and chemical analyses of water included determination of temperature, pH, turbidity, electrical conductivity, total dissolved solids, salinity, dissolved oxygen, and biological oxygen demand. The results of water before and after purification indicated values within the international allowable levels. Microbial analyses included estimation of the number of total viable microbial counts, total coliform, total fecal E. coli and Pseudomonas aeruginosa, and other pathogenic bacteria that might be present in the water of the three stations and of the Tigris River, and also the tap water from Al-Shula houses. The results indicated that the types and proportions of various bacterial species isolated from different water sources were almost similar. This indicates inefficient purification procedures in all the stations studied, which exceeded the internationally allowable level of pathogens in potable water. Also, this explains the high incidence rate of children diarrheal reported in Al-Shula region. PMID:23365587

  1. 78 FR 57323 - York River and the Naval Weapons Station Yorktown-Cheatham Annex, Yorktown, Virginia; Danger Zone

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-18

    ... Department of the Army, Corps of Engineers 33 CFR Part 334 York River and the Naval Weapons Station Yorktown... and the Naval Weapons Station Yorktown- Cheatham Annex, Yorktown, Virginia; danger zone. (a) The area... firing activities shall be conducted when the visibility is less that the maximum range of the...

  2. 33 CFR 334.285 - York River and the Naval Weapons Station Yorktown-Cheatham Annex, Yorktown, Virginia; danger zone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false York River and the Naval Weapons... RESTRICTED AREA REGULATIONS § 334.285 York River and the Naval Weapons Station Yorktown-Cheatham Annex... less than the maximum range of the weapons being used at the facility or while a vessel is within...

  3. 33 CFR 165.553 - Security Zone; Salem and Hope Creek Generation Stations, Delaware River, Salem County, New Jersey.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Creek Generation Stations, Delaware River, Salem County, New Jersey. 165.553 Section 165.553 Navigation... Limited Access Areas Fifth Coast Guard District § 165.553 Security Zone; Salem and Hope Creek Generation...: the waters of the Delaware River in the vicinity of the Salem and Hope Creek Generation...

  4. 33 CFR 165.553 - Security Zone; Salem and Hope Creek Generation Stations, Delaware River, Salem County, New Jersey.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Creek Generation Stations, Delaware River, Salem County, New Jersey. 165.553 Section 165.553 Navigation... Limited Access Areas Fifth Coast Guard District § 165.553 Security Zone; Salem and Hope Creek Generation...: the waters of the Delaware River in the vicinity of the Salem and Hope Creek Generation...

  5. 33 CFR 165.553 - Security Zone; Salem and Hope Creek Generation Stations, Delaware River, Salem County, New Jersey.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Creek Generation Stations, Delaware River, Salem County, New Jersey. 165.553 Section 165.553 Navigation... Limited Access Areas Fifth Coast Guard District § 165.553 Security Zone; Salem and Hope Creek Generation...: the waters of the Delaware River in the vicinity of the Salem and Hope Creek Generation...

  6. 33 CFR 165.553 - Security Zone; Salem and Hope Creek Generation Stations, Delaware River, Salem County, New Jersey.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Creek Generation Stations, Delaware River, Salem County, New Jersey. 165.553 Section 165.553 Navigation... Limited Access Areas Fifth Coast Guard District § 165.553 Security Zone; Salem and Hope Creek Generation...: the waters of the Delaware River in the vicinity of the Salem and Hope Creek Generation...

  7. 33 CFR 165.553 - Security Zone; Salem and Hope Creek Generation Stations, Delaware River, Salem County, New Jersey.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Creek Generation Stations, Delaware River, Salem County, New Jersey. 165.553 Section 165.553 Navigation... Limited Access Areas Fifth Coast Guard District § 165.553 Security Zone; Salem and Hope Creek Generation...: the waters of the Delaware River in the vicinity of the Salem and Hope Creek Generation...

  8. Benthic community of the Savannah River below a peaking hydropower station

    USGS Publications Warehouse

    Hudson, Patrick L.; Nichols, S. Jerrine

    1986-01-01

    The Savannah River below Hartwell Dam, on the South Carolina-Georgia border, contains at least 206 benthic invertebrate taxa, even though this tailwater undergoes substantial daily fluctuations in water flow, temperature, and dissolved oxygen. Oligochaetes, chironomids, and amphipods dominate the community immediately below the dam. Farther downstream, larger organisms (i.e., Ephemeroptera, Trichoptera, etc.) dominate the benthic community. The high diversity of this system is primarily attributed to the intensive effort we expended to identify invertebrates to species level. We conclude that tailwaters associated with peaking hydropower stations may in fact have the diverse community assemblages found in natural streams and that this has not been recognized by other investigators because the bulk of the fauna is made up of small forms that are easily overlooked. Comparisons of tailwater fauna communities with those in control areas should be limited to rivers of similar size.

  9. Flood hazard assessment of the Hoh River at Olympic National Park ranger station, Washington

    USGS Publications Warehouse

    Kresch, D.L.; Pierson, T.C.

    1987-01-01

    Federal regulations require buildings and public facilities on Federal land to be located beyond or protected from inundation by a 100-year flood. Flood elevations, velocities and boundaries were determined for the occurrence of a 100-year flood through a reach, approximately 1-mi-long, of the Hoh River at the ranger station complex in Olympic National Park. Flood elevations, estimated by step-backwater analysis of the 100-year flood discharge through 14 channel and flood-plain cross sections of the Hoh River, indicate that the extent of flooding in the vicinity of buildings or public facilities at the ranger station complex is likely to be limited mostly to two historic meander channels that lie partly within loop A of the public campground and that average flood depths of about 2 feet or less would be anticipated in these channels. Mean flow velocities at the cross sections, corresponding to the passage of a 100-year flood, ranged from about 5 to over 11 ft/sec. Flooding in the vicinity of either the visitors center or the residential and maintenance areas is unlikely unless the small earthen dam at the upstream end of Taft Creek were to fail. Debris flows with volumes on the order of 100 to 1,000 cu yards could be expected to occur in the small creeks that drain the steep valley wall north of the ranger station complex. Historic debris flows in these creeks have generally traveled no more than about 100 yards out onto the valley floor. The potential risk that future debris flows in these creeks might reach developed areas within the ranger station complex is considered to be small because most of the developed areas within the complex are situated more than 100 yards from the base of the valley wall. Landslides or rock avalanches originating from the north valley wall with volumes potentially much larger than those for debris flows could have a significant impact on the ranger station complex. The probability that such landslides or avalanches may occur is

  10. Numerical modeling of erosional and depositional bank processes in migrating river bends with self-formed width: Morphodynamics of bar push and bank pull

    NASA Astrophysics Data System (ADS)

    Eke, Esther; Parker, Gary; Shimizu, Yasuyuki

    2014-07-01

    Meandering rivers display active communication between bank erosion and bar deposition processes. How does this occur? How does the river select its width? To answer these questions, we implement a model for meander migration where both bank processes (erosion and deposition) are considered independently. Bank erosion is modeled as erosion of purely noncohesive bank material damped by natural slump block armoring; channel deposition is modeled via flow-retarded vegetal encroachment. Both processes are tied to a slope-dependent channel forming Shields number; banks with near-bank Shields number below this value undergo deposition, and those above it undergo erosion. Channel-forming Shields number must increase with slope, as dictated by available data and model performance. Straight channel modeling shows that a channel arrives at an equilibrium width from any initial condition. For the channel bend, the river always approaches an asymptotic state where width reduces slowly in time and where bank erosion and deposition occur at nearly equal rates. Before this state is reached, however, the river follows a phase-plane trajectory with four possible regimes: (a) both banks erode, (b) both banks deposit, (c) both banks migrate outward, but with a faster depositing bank (bar push), and (d) both banks migrate outward, but with a faster eroding bank (bank pull). The trajectory of migration on the phase plane depends on initial conditions and input parameters controlling the rate of depositional and erosional migration. All input parameters have specific physical meaning, and the potential to be measured in the field.

  11. Uncertainty in low-flow data from three streamflow-gaging stations on the upper Verde River, Arizona

    USGS Publications Warehouse

    Anning, D.W.

    2004-01-01

    The evaluation of uncertainty in low-flow data collected from three streamflow-gaging stations on the upper Verde River, Arizona, was presented. In downstream order, the stations are Verde River near Paulden, Verde River near Clarkdale, and Verde River near Camp Verde. A monitoring objective of the evaluation was to characterize discharge of the lower flow regime through a variety of procedures such as frequency analysis and base-flow analysis. For Verde River near Paulden and near Camp Verde, the uncertainty of daily low flows can be reduced by decreasing the uncertainty of discharge-measurement frequency, or building an artificial control that would have a stable stage-discharge relation over time.

  12. SRI CAT Section 1 bending magnet beamline description

    SciTech Connect

    Srajer, G.; Rodricks, B.; Assoufid, L.; Mills, D.M.

    1994-03-10

    This report discusses: APS bending magnet source; beamline layout; beamline optical components; beamline operation; time-resolved studies station; polarization studies station; and commissioning and operational schedule.

  13. Intercomparison study of atmospheric methane and carbon dioxide concentrations measured at the Ebre River Delta Station

    NASA Astrophysics Data System (ADS)

    Occhipinti, Paola; Morguí, Josep Anton; Àgueda, Alba; Batet, Oscar; Borràs, Sílvia; Cañas, Lídia; Curcoll, Roger; Grossi, Claudia; Nofuentes, Manel; Vazquez, Eusebi; Rodó, Xavier

    2015-04-01

    In the framework of the ClimaDat project, IC3 has established a network of eight monitoring stations across the Iberian Peninsula and the Canarian Archipelago with the aim of studying climate processes. The monitoring station at the Ebre River Delta (DEC3) is located in the Ebre River Delta Natural Park (40° 44' N; 0° 47' E) and it is characterized by the typical North-Western Mediterranean climate. Since 2013, atmospheric greenhouse gases (GHG) and 222Rn tracer gas together with the meteorological parameters are continuously measured from a 10 m a.g.l. height tower. Atmospheric GHG (CO2, CH4, CO and N2O) concentrations are determined using a Picarro analyzer G2301 (CO2 and CH4) and a modified gas chromatograph (GC) Agilent 6890N (CO2, CH4, CO and N2O). Open data access is available from the www.climadat.es website. Data collected at the DEC3 station are also submitted to the InGOS platform since this station is part of the InGOS European infrastructure project. Researchers from the Laboratory of the Atmosphere and the Oceans (LAO) at IC3 have performed an intercomparison study at the DEC3 site between three different Picarro analyzers (two Picarro G2301 and one Picarro G2301M), a Los Gatos Research (LGR) analyzer and the GC system already installed at the station. The aim of this study is to compare and assess the measuring agreement between the four optical gas analyzers and the GC. In the first part of the experiment, all instruments have been calibrated using NOAA gases as primary standards analyzing five Praxair provided targets to evaluate the precision of the measuring instruments. Max Plank Institute (MPI) gases have been used as secondary standards for the GC whereas Praxair provided tanks are used as secondary standards for the Picarro and the LGR analyzers. In the second part of the experiment, atmospheric GHG were measured from natural atmospheric air taken from a 10 m a.g.l. inlet. Daily cycles of GHG measurements were carried out using different

  14. A novel permanent gauge-cam station for surface-flow observations on the Tiber River

    NASA Astrophysics Data System (ADS)

    Tauro, Flavia; Petroselli, Andrea; Porfiri, Maurizio; Giandomenico, Lorenzo; Bernardi, Guido; Mele, Francesco; Spina, Domenico; Grimaldi, Salvatore

    2016-06-01

    Flow monitoring of riverine environments is crucial for hydrology and hydraulic engineering practice. Besides few experimental implementations, flow gauging relies on local water level and surface-flow velocity measurements through ultrasonic meters and radars. In this paper, we describe a novel permanent gauge-cam station for large-scale and continuous observation of surface flows, based on remote acquisition and calibration of video data. Located on the Tiber River, in the center of Rome, Italy, the station captures 1 min videos every 10 min over an area oriented along the river cross section of up to 20.6 × 15.5 m2. In a feasibility study, we demonstrate that accurate surface-flow velocity estimations can be obtained by analyzing experimental images via particle tracking velocimetry (PTV). In medium illumination conditions (70-75 lux), PTV leads to velocity estimations in close agreement with radar records and is less affected by uneven lighting than large-scale particle image velocimetry. Future efforts will be devoted to the development of a comprehensive test bed infrastructure for investigating the potential of multiple optics-based approaches for surface hydrology.

  15. Retrieval of river discharge solely from satellite imagery and at-many-stations hydraulic geometry: Sensitivity to river form and optimization parameters

    NASA Astrophysics Data System (ADS)

    Gleason, Colin J.; Smith, Laurence C.; Lee, Jinny

    2014-12-01

    Knowledge of river discharge is critically important for water resource management, climate modeling, and improved understanding of the global water cycle, yet discharge is poorly known in much of the world. Remote sensing holds promise to mitigate this gap, yet current approaches for quantitative retrievals of river discharge require in situ calibration or a priori knowledge of river hydraulics, limiting their utility in unmonitored regions. Recently, Gleason and Smith (2014) demonstrated discharge retrievals within 20-30% of in situ observations solely from Landsat TM satellite images through discovery of a river-specific geomorphic scaling phenomenon termed at-many-stations hydraulic geometry (AMHG). This paper advances the AMHG discharge retrieval approach via additional parameter optimizations and validation on 34 gauged rivers spanning a diverse range of geomorphic and climatic settings. Sensitivity experiments reveal that discharge retrieval accuracy varies with river morphology, reach averaging procedure, and optimization parameters. Quality of remotely sensed river flow widths is also important. Recommended best practices include a proposed global parameter set for use when a priori information is unavailable. Using this global parameterization, AMHG discharge retrievals are successful for most investigated river morphologies (median RRMSE 33% of in situ gauge observations), except braided rivers (median RRMSE 74%), rivers having low at-a-station hydraulic geometry b exponents (reach-averaged b < 0.1, median RRMSE 86%), and arid rivers having extreme discharge variability (median RRMSE > 1000%). Excluding such environments, 26-41% RRMSE agreement between AMHG discharge retrievals and in situ gauge observations suggests AMHG can meaningfully address global discharge knowledge gaps solely from repeat satellite imagery.

  16. Delivery of water from Belton Reservoir to the Brazos River gaging station at Richmond, Texas, by way of the Leon, Little, and Brazos River channels, 1956

    USGS Publications Warehouse

    Havelka, D.E.; Parten, E.M.

    1957-01-01

    Beginning November 1, 1956 and ending December 14, 1956, the Corps of Engineers, in cooperation with the Brazos River Authority released 73,000 acre-feet of water (as measured at the gaging station on Leon river near Belton) from the Belton Reservoir for industrial use in the vicinity of Freeport, Tex. (see fig. 1). The need for this water at Freeport came as a result of the prolonged drought conditions causing flows in the Brazos River in the vicinity of Freeport to be insufficient to satisfy the industrial and other uses of vital importance.

  17. Discharge Estimation Using Satellite Gravity During Flood Seasons at the Óbidos Gauge Station, Amazon River

    NASA Astrophysics Data System (ADS)

    Eom, J.; Seo, K. W.; Lee, Y. K.

    2014-12-01

    Reliable measurement of river discharge is important for management of water resource and understanding of hydrological cycles particularly associated with global and regional climate changes. Practically, to obtain continuous time series of river discharge, regression analysis of an empirical relationship between accumulated water level and discharge data is used. During wet season, however, the relationship includes more uncertainty due to the difficulty of accurate discharge measurement. This is particularly true for the Amazon River because significant amount of water flows outside river channel during flooding. For an alternative way to estimate river discharge, we use GRACE time-varying gravity measurement from January 2003 to December 2012. We first apply Empirical Orthogonal Function (EOF) for GRACE time-varying gravity fields in Amazon and successfully isolate gravity signal in the main stream. The EOF time series represents relative river discharge variations without larger uncertainty during flooding season compared to conventional in-situ discharge estimate. Estimates of Amazon River discharge based on GRACE data are very close to those from observed at gauge stations during dry seasons. However, our estimates are larger than in-situ data in high water seasons, and the difference is the maximum at the 2009 flooding. This is probably because in-situ observation underestimates river discharge during wet season due possibly to detoured water in river pathway developed during flooding while GRACE observes integrated water mass variations in river channels.

  18. Output improvement of Sg. Piah run-off river hydro-electric station with a new computed river flow-based control system

    NASA Astrophysics Data System (ADS)

    Jidin, Razali; Othman, Bahari

    2013-06-01

    The lower Sg. Piah hydro-electric station is a river run-off hydro scheme with generators capable of generating 55MW of electricity. It is located 30km away from Sg. Siput, a small town in the state of Perak, Malaysia. The station has two turbines (Pelton) to harness energy from water that flow through a 7km tunnel from a small intake dam. The trait of a run-off river hydro station is small-reservoir that cannot store water for a long duration; therefore potential energy carried by the spillage will be wasted if the dam level is not appropriately regulated. To improve the station annual energy output, a new controller based on the computed river flow has been installed. The controller regulates the dam level with an algorithm based on the river flow derived indirectly from the intake-dam water level and other plant parameters. The controller has been able to maintain the dam at optimum water level and regulate the turbines to maximize the total generation output.

  19. Disturbance of the Boundary Layer at Summit Station, Greenland by an Atmospheric River

    NASA Astrophysics Data System (ADS)

    Neff, William; Shupe, Mathew; Ralph, Marty

    2014-05-01

    On 11 July 2012, a rare melt episode occurred at Summit Station Greenland. As described by Neff et al. 2014 (Submitted JGR), a major factor in this melt event was an Atmospheric River (AR), a narrow corridor of high water-vapor content. This AR transited the western Atlantic and theen moved up the west coast of Greenland and thence over Greenland. Back trajectories also indicated significant warm air advection from mid-North America during a major heat wave. We present here the boundary layer changes during this event using sodar to distinguish well-mixed from stable periods and relate these to changes in synoptic forcing and resulting changes in radiative forcing by low-level, shallow, warm clouds. A second near-melt episode also occurred on 29 July which provides an opportunity to compare and contrast boundary layer responses in the two cases.

  20. Holocene sedimentation and coastal wetlands response to rising sea level at the Aucilla river mouth, a low energy coast in the Big Bend area of Florida

    USGS Publications Warehouse

    Garrett, Connie; Hertler, Heidi; Hoenstine, Ronald; Highley, Brad

    1993-01-01

    The shallow dip of the Florida carbonate platform results in low wave energy on Florida ???Big Bend??? coasts. Therefore sedimentation is dominated by river-and tidal-hydrodynamics near the Aucilla River mouth. Where present, Holocene sediments are thin and unconformably overlie Oligocene-aged Suwannee Limestone. The oldest unlithified sediments include reworked carbonate rubble with clay and wood fragments (seven thousand years old or less, based on wood radio-carbon dating). Although this basal sequence is observed in most areas, the sediments that overlie it vary. Sediment sequences from the outer littoral to submarine environments include organic-rich sands, oyster biotherm remains, and cleaner sands with organic-filled burrows. Inner littoral (salt-marsh) sequences generally consist of sandy, fining-upwards sequences in which dry weights of fine-grained clastics and organic components increase up-sequence at similar rates. Offshore sediments preserve greatly attenuated fluvial and salt-marsh facies, if these facies are preserved at all. With sea-level rise, erosion can result from insufficient sediment supply and down-cutting by tidal currents (Dolotov, 1992; and Dalrymple et al., 1992). Dolotov (1992) attributes displacement of original coastal stratigraphy to insufficient sediments for beach profile maintenance, while Dalrymple et al. (1992) attribute erosional truncation (ravinement) or complete removal of portions of typical estuarine sequences to headward migration of tidal channels.

  1. Flow Estimate of Carbon Dioxide in a Amazon River Hydrological Station

    NASA Astrophysics Data System (ADS)

    Moura, J. M. S.; Ferreira, R. B., Jr.; Tapajós, R. P.

    2014-12-01

    Recent measurements in the Amazon suggest that the flow of CO2 in surface waters may reach the order of 1GT per year and isotopic analyzes suggest that this carbon is a direct result of organic matter degradation (OMD) in rivers and the measured concentration exceeds the value expected for there to be equilibrium with the atmosphere (Richey et al, 2002). This study aimed to measure and check the seasonal variability of CO2 fluxes in a range of six months (September 2013-February 2014) in the Strait Óbidos hydrological station located geographically in the coordinates 55 ° 1 '4 "S and 55 ° 31' 4" W. In addiction, it is intended to correlate the data with physical-chemical water parameters pH, dissolved oxygen (DO), and temperature and humidity. The method used for the measurement of CO2 concentration in the atmosphere-water interface is the floating chamber liked with an infrared gas analyzer (IRGA- Infrared Gas Analyzer). The physical-chemical parameters of water were measured using a multiparameter probe YSI Professional Plus model. The preliminary results shows values average CO2 flux was approximately 15.65 1,01ppm / m2s-1 for the months of September and October and between the months of November, 2013 and February 2014 the CO2 flux average was 4.40 + 1.94 ppm / m2s-1. In addiction to the high temperature in dry season, in the water column there is sufficient convection for the existence of gases transport from water to atmosphere, resulting in increase of exchange. Thus, the decreased amount of radiation and consequently the low temperatures in the humid period (on average 27.2 ° C) should affect the OMD in the river, responsible for the production of dissolved CO2. Keywords: CO2 flux, seasonal variability, amazon river

  2. Dating the incision of the Yangtze River gorge at the First Bend using three-nuclide burial ages

    NASA Astrophysics Data System (ADS)

    McPhillips, Devin; Hoke, Gregory D.; Liu-Zeng, Jing; Bierman, Paul R.; Rood, Dylan H.; Niedermann, Samuel

    2016-01-01

    Incision of the Yangtze River gorge is widely interpreted as evidence for lower crustal flow beneath the southeast margin of the Tibetan Plateau. Previous work focused on the onset of incision, but the duration of incision remains unknown. Here we present cosmogenic nuclide burial ages of sediments collected from caves on the walls of the gorge that show the gorge was incised ~1 km sometime between 18 and 9 Ma. Thereafter, incision slowed substantially. We resolve middle Miocene burial ages by using three nuclides and accounting for in situ muogenic production. This approach explains the absolute concentrations of 10Be, 26Al, and 21Ne, as well as 26Al/10Be and 21Ne/10Be ratios. A declining incision rate challenges existing geodynamic interpretations by suggesting that either (1) surface uplift has ceased immediately south of the plateau margin or (2) gorge incision is not a useful proxy for the timing of surface uplift.

  3. Spatial patterns of groundwater-surface water interactions at the meander-bend scale in a gravel-bed lowland river during a large-scale flow experiment

    NASA Astrophysics Data System (ADS)

    Bray, E. N.; Dunne, T.

    2012-12-01

    Improved characterization of 1) streambed hydraulic conductivity and 2) near-bed and subsurface water temperatures allows better understanding of the spatial patterns of groundwater-surface water exchange in rivers. We measured the effects of a large-scale flow experiment on groundwater-surface water exchange and temperature using fiber optic distributed temperature sensing (DTS), measured temperature in the shallow hyporheic zone (46 cm), and measured streambed saturated hydraulic conductivity (Ksat) over the length of three river meander bends (2 km). Measured channel bed elevation, flow depth, velocity, and bed-material grain size were used to develop a two-dimensional numerical model of the flow field as boundary conditions for a model of the hyporheic flow field. We deployed 2 km of fiber-optic cable directly on top of the riverbed over three pool-riffle sequences each with a different degree of bed mobility. DTS data were collected every 2 m for 32 days (1.5 days at 10 cms, 10 days at 20 cms, 16 days at 10 cms, and 4.5 days at 2-4 cms). Three installations of six hyporheic zone sensors, located near the upstream and downstream ends of the DTS cable, recorded interstitial pore water temperature at depths of 46 cm. During flows of 10 cms, we measured Ksat in the streambed at depths of 60 cm using a groundwater standpipe and backpack permeameter over the length of two meander bends. DTS results showed relatively uniform temperature over the 2-km reach during the initial flow of 10 cms. Near-bed temperatures averaged 15.6°C while pore water temperatures averaged 15.4°C. The 20 cms flow decreased near-bed temperatures to 14.9°C and pore water temperatures averaged 14.7°C. However, during the 20 cms flow, the bed became mobile causing local scour and deposition at three locations and buried the DTS cable with gravel/sand up to 26 cm deep. Our DTS results allowed us to record the transition from near-bed temperatures to shallow subsurface temperatures during a

  4. Analysis of current-meter data at Columbia River gaging stations, Washington and Oregon

    USGS Publications Warehouse

    Savini, John; Bodhaine, G.L.

    1971-01-01

    The U.S. Geological Survey developed equipment to measure stream velocity simultaneously with 10 current meters arranged in a vertical and to measure velocity closer to the streambed than attainable with conventional equipment. With the 10 current meters, synchronous velocities were recorded for a period of 66 minutes at 10 different depths in one vertical of one gaging-station cross section. In addition, with a current meter installed on a special bracket to allow measurements to 0.5 foot above streambed, data were obtained at two to four verticals in four gaging-station cross sections. The mean velocity determined for the 66-minute period of record was 3.30 fps (feet per second). The graphic record of velocity was analyzed on a minute-by-minute basis. It was noted that the shape of the vertical velocity curves (plot of horizontal flow velocities measured in a vertical) changed from one minute to the next, but the change seemed to be random. Velocities obtained at different depths in the, profile fluctuated significantly, with the 1-minute velocities obtained at 0.05 depth (5 percent of total depths measured from the surface at indicated vertical) showing the smallest range--0.66 fps--and those at 0.55 depth the largest range--l.22 fps. The standard deviation, expressed in feet per second, of the velocity at each point in the vertical tended to increase with depth--from 0.16 fps at 0.05 depth to a maximum of 0.24 fps at 0.75 depth. The standard deviation, expressed as a percentage of the mean velocity, ranged from about 4 percent near the surface to 11 percent at 0.95 depth. In spite of the fluctuation in mean velocity that occurred during the 66 minutes and observation period of 4 minutes yields a mean velocity that differs from the 66-minute mean by less than one-half of a percent. Determining the mean velocity by averaging the 10-point observations of the 66minute run proved to be as accurate as by plotting the vertical velocity curvy (from the averaged 10

  5. A Rolling Flood Forecast Method for River Basins with Newly-Built Meteorological and Hydrological Station Network

    NASA Astrophysics Data System (ADS)

    Shi, H.

    2014-12-01

    Destructive flash floods occurred more frequently in the small and medium river basins in China recently. However, meteorological and hydrological station networks in such river basins were usually poor. Some of them were newly-built only several years ago so that long-series observations are unavailable; and therefore, it is impossible to gain the most suitable parameters for flood forecast from the historical data directly. This paper developed a rolling flood forecast method for such regions, taking the Leli River basin in Guangxi Province, China, as the study area. The Digital Yellow River Integrated Model (DYRIM) was adopted to simulate the streamflows of the Tianlin hydrological station for each flood during the study period, and the model parameters were rolling optimized in real time as follows. First, the parameters were calibrated with the observed rainfall and streamflow data of the first flood, and they were used to forecast the flood caused by the next rain. Second, when the rain came true, the parameters were modified with the newly-observed rainfall and streamflow data if the simulation result obtained with the parameters of the last flood was not satisfied; and the new parameters would be used to forecast the next flood. Through repeating the above two steps for each flood, the parameters may be optimized constantly; and finally, the value ranges of the parameters could be obtained. From a sample demonstration, it can be concluded that this flood forecast method was feasible; it would be valuable for the flood forecast of river basins with newly-built meteorological and hydrological station network.

  6. Using NASA's Giovanni System to Simulate Time-Series Stations in the Outflow Region of California's Eel River

    NASA Technical Reports Server (NTRS)

    Acker, James G.; Shen, Suhung; Leptoukh, Gregory G.; Lee, Zhongping

    2012-01-01

    Oceanographic time-series stations provide vital data for the monitoring of oceanic processes, particularly those associated with trends over time and interannual variability. There are likely numerous locations where the establishment of a time-series station would be desirable, but for reasons of funding or logistics, such establishment may not be feasible. An alternative to an operational time-series station is monitoring of sites via remote sensing. In this study, the NASA Giovanni data system is employed to simulate the establishment of two time-series stations near the outflow region of California s Eel River, which carries a high sediment load. Previous time-series analysis of this location (Acker et al. 2009) indicated that remotely-sensed chl a exhibits a statistically significant increasing trend during summer (low flow) months, but no apparent trend during winter (high flow) months. Examination of several newly-available ocean data parameters in Giovanni, including 8-day resolution data, demonstrates the differences in ocean parameter trends at the two locations compared to regionally-averaged time-series. The hypothesis that the increased summer chl a values are related to increasing SST is evaluated, and the signature of the Eel River plume is defined with ocean optical parameters.

  7. Hanford Meteorological Station computer codes: Volume 7, The RIVER computer code

    SciTech Connect

    Andrews, G.L.; Buck, J.W.

    1988-03-01

    The RIVER computer code is used to archive Columbia River data measured at the 100N reactor. The data are recorded every other hour starting at 0100 Pacific Standard Time (12 observations in a day), and consists of river elevation, temperature, and flow rate. The program prompts the user for river data by using a data entry form. After the data have been enetered and verified, the program appends each hour of river data to the end of each corresponding surface observation record for the current day. The appended data are then stored in the current month's surface observation file.

  8. 33 CFR 334.540 - Banana River at the Eastern Range, 45th Space Wing, Cape Canaveral Air Force Station, FL...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., 45th Space Wing, Cape Canaveral Air Force Station, FL; restricted area. 334.540 Section 334.540... navigable waters of the United States, as defined at 33 CFR part 329, within the Banana River contiguous to... AND RESTRICTED AREA REGULATIONS § 334.540 Banana River at the Eastern Range, 45th Space Wing,...

  9. GENERAL VIEW OF TUMALO FEED CANAL (RIGHT) AND BEND FEED ...

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

    GENERAL VIEW OF TUMALO FEED CANAL (RIGHT) AND BEND FEED CANAL (LEFT) INTERSECTION. LOOKING SOUTHEAST - Tumalo Irrigation District, Tumalo Project, West of Deschutes River, Tumalo, Deschutes County, OR

  10. An extensive survey of dayside diffuse aurora based on optical observations at Yellow River Station

    NASA Astrophysics Data System (ADS)

    Han, De-Sheng; Chen, Xiang-Cai; Liu, Jian-Jun; Qiu, Qi; Keika, K.; Hu, Ze-Jun; Liu, Jun-Ming; Hu, Hong-Qiao; Yang, Hui-Gen

    2015-09-01

    By using 7 years optical auroral observations obtained at Yellow River Station (magnetic latitude 76.24°N) at Ny-Alesund, Svalbard, we performed the first extensive survey for the dayside diffuse auroras (DDAs) and acquired observational results as follows. (1) The DDAs can be classified into two broad categories, i.e., unstructured and structured DDAs. The unstructured DDAs are mainly distributed in morning and afternoon, but the structured DDAs predominantly occurred around the magnetic local noon (MLN). (2) The unstructured DDAs observed in morning and afternoon present obviously different properties. The afternoon ones are much stable and seldom show pulsating property. (3) The DDAs are more easily observed under geomagnetically quiet times. (4) The structured DDAs mainly show patchy, stripy, and irregular forms and are often pulsating and drifting. The drifting directions are mostly westward (with speed ~5 km/s), but there are cases showing eastward or poleward drifting. (5) The stripy DDAs are exclusively observed near the MLN and, most importantly, their alignments are confirmed to be consistent with the direction of ionospheric convection near the MLN. (6) A new auroral form, called throat aurora, is found to be developed from the stripy DDAs. Based on the observational results and previous studies, we proposed our explanations to the DDAs. We suggest that the unstructured DDAs observed in the morning are extensions of the nightside diffuse aurora to the dayside, but that observed in the afternoon are predominantly caused by proton precipitations. The structured DDAs occurred near the MLN are caused by interactions of cold plasma structures, which are supposed to be originated from the ionospheric outflows or plasmaspheric drainage plumes, with hot electrons from the plasma sheet. We suppose that the cold plasma structures for producing the patchy DDAs are in lumpy and are more likely from the plasmaspheric drainage plumes. The cold plasma structure for

  11. Analysis of minimum 7-day discharges and estimation of minimum 7-day, 2-year discharges for streamflow-gaging stations in the Brazos River basin, Texas

    USGS Publications Warehouse

    Raines, Timothy H.; Asquith, William H.

    1997-01-01

    The 7Q2 is zero for 31 of the 46 unregulated-only stations and for 9 of the 26 regulated-only stations. The 7Q2 also is zero for 9 stations before regulation and for 3 stations after regulation of the 25 stations with both unregulated and regulated data. The 7Q2 ranges from 33 to 631 cubic feet per second for the eight regulated-only stations on the mainstem Brazos River. For the seven stations on the mainstem Brazos River with at least 10 years of unregulated and 10 years of regulated discharge data, the 7Q2 ranges from 0 to 568 cubic feet per second before regulation and from 0.30 to 670 cubic feet per second after regulation. The 7Q2 increased during regulation for 19 of the 25 stations with both unregulated and regulated data. The effect of regulation for most stations generally was an increase in the magnitude of the 7Q2.

  12. Testing simple methodologies to estimate at-a-station hydraulic geometry in large river networks with limited observations

    NASA Astrophysics Data System (ADS)

    Gomez-Velez, J. D.; Choi, J. J.; Harvey, J. W.

    2015-12-01

    Explaining water quality in large basins requires estimates of hydraulic geometry at sampling sites or stations with water quality data sets for varying flow conditions. In this work, we present two parsimonious methodologies to estimate channel width and depth as a function of channel discharge in large river networks. The first method uses high quality but relatively sparse measurements to empirically estimate downstream hydraulic geometry expressions for mean annual and bankfull flow conditions and the theory of at-a-station hydraulic geometry. The second method combines conservation of mass, momentum (encapsulated in a resistance parameterization), and a morphological classification scheme to estimate hydraulic geometry. As a proof-of-concept, we use both methods to estimate the hydraulic geometry for the conterminous US at the scale of the NHD Plus river network. The main advantages of the proposed methodologies are (i) the parameterization in terms of data widely available at the continental scale, (ii) the low computational burden, and (iii) the consistency with previous observational efforts at the scale of individual watersheds and the ability to capture the main scaling characteristics observed in natural systems.

  13. Nitrogen cycling processes and microbial community composition in bed sediments in the Yukon River at Pilot Station

    NASA Astrophysics Data System (ADS)

    Repert, Deborah A.; Underwood, Jennifer C.; Smith, Richard L.; Song, Bongkeun

    2014-12-01

    Information on the contribution of nitrogen (N)-cycling processes in bed sediments to river nutrient fluxes in large northern latitude river systems is limited. This study examined the relationship between N-cycling processes in bed sediments and N speciation and loading in the Yukon River near its mouth at the Bering Sea. We conducted laboratory bioassays to measure N-cycling processes in sediment samples collected over distinct water cycle seasons. In conjunction, the microbial community composition in the bed sediments using genes involved in N-cycling (narG, napA, nosZ, and amoA) and 16S rRNA gene pyrosequences was examined. Temporal variation was observed in net N mineralization, nitrate uptake, and denitrification rate potentials and correlated strongly with sediment carbon (C) and extractable N content and microbial community composition rather than with river water nutrient concentrations. The C content of the bed sediment was notably impacted by the spring flood, ranging from 1.1% in the midst of an ice-jam to 0.1% immediately after ice-out, suggesting a buildup of organic material (OM) prior to scouring of the bed sediments during ice break up. The dominant members of the microbial community that explained differences in N-processing rates belonged to the genera Crenothrix, Flavobacterium, and the family of Comamonadaceae. Our results suggest that biogeochemical processing rates in the bed sediments appear to be more coupled to hydrology, nutrient availability in the sediments, and microbial community composition rather than river nutrient concentrations at Pilot Station.

  14. Nitrogen cycling processes and microbial community composition in bed sediments in the Yukon River at Pilot Station

    USGS Publications Warehouse

    Repert, Deborah A.; Underwood, Jennifer C.; Smith, Richard L.; Song, Bongkeun

    2014-01-01

    Information on the contribution of nitrogen (N)-cycling processes in bed sediments to river nutrient fluxes in large northern latitude river systems is limited. This study examined the relationship between N-cycling processes in bed sediments and N speciation and loading in the Yukon River near its mouth at the Bering Sea. We conducted laboratory bioassays to measure N-cycling processes in sediment samples collected over distinct water cycle seasons. In conjunction, the microbial community composition in the bed sediments using genes involved in N-cycling (narG, napA, nosZ, and amoA) and 16S rRNA gene pyrosequences was examined. Temporal variation was observed in net N mineralization, nitrate uptake, and denitrification rate potentials and correlated strongly with sediment carbon (C) and extractable N content and microbial community composition rather than with river water nutrient concentrations. The C content of the bed sediment was notably impacted by the spring flood, ranging from 1.1% in the midst of an ice-jam to 0.1% immediately after ice-out, suggesting a buildup of organic material (OM) prior to scouring of the bed sediments during ice break up. The dominant members of the microbial community that explained differences in N-processing rates belonged to the genera Crenothrix,Flavobacterium, and the family of Comamonadaceae. Our results suggest that biogeochemical processing rates in the bed sediments appear to be more coupled to hydrology, nutrient availability in the sediments, and microbial community composition rather than river nutrient concentrations at Pilot Station.

  15. Evaluating long-term trends in mean- and high- river flows using a network of reference stations in Ireland

    NASA Astrophysics Data System (ADS)

    Wilby, R. L.; Murphy, C.; Harrigan, S.; Hall, J.

    2012-12-01

    This paper describes the development of a reference hydrometric network for Ireland established primarily for the detection of climate driven trends in mean and high river flows. Thirty-five stations were identified for inclusion in the network plus a further 8 from the UK Benchmark Network. Their average record length is 40 years with a minimum of 28 and maximum of 63 years. Time series were derived for eight river flow indices: annual and seasonal mean flows and the annual maximum 1-, 10- and 30-day flows. Mann Kendall and Theil Sen statistics were applied to all indices using fixed and variable start/end dates. Trends in the winter mean are found to be highly dependent on the chosen period of analysis with the longest records showing increased flows. Contrary to expectations (of regional climate change scenarios), increases are also evident for long-term summer mean flows. High flow metrics exhibit positive and persistent trends that are less affected by inter-annual variability and period of record. Overall, there is strong spatial coherence in these patterns of change, linked to temporal variations in precipitation. Our results highlight the dangers of using conventional fixed periods such as 1961-1990 for trend detection, recognising that there is always a trade-off between record length, density of the network, and geographic coverage. Furthermore, outliers at the beginning of the record can be an artefact of the original motivation for installing the gauging station(s). In this case, water resource concerns during a markedly dry period in the mid-1970s favour positive trends over subsequent decades. Future work will focus on detection times for climate change signals and the identification of sentinel sites for discerning early signs of anthropogenic climate change across Ireland. Broader lessons for monitoring and detection of anthropogenic climate change signals will also be distilled.

  16. Data for selected gaging stations in the upper Red River of the North Basin in Minnesota, September 2001 through September 2003

    USGS Publications Warehouse

    Damschen, William C.; Nustad, Rochelle A.

    2005-01-01

    Surface-water and water-quality data were collected to use in development of upper Red River of the North Basin Total Maximum Daily Loads (TMDLs). This report presents the data that were collected. During September 2001 through September 2003, data were collected at 13 selected gaging stations in the upper Red River of the North Basin. Continuous streamflow data were collected at three of the gaging stations. Water-quality samples were collected at all 13 gaging stations; and, simultaneous with sample collection, in-stream specific conductance, pH, water temperature, dissolved oxygen, and turbidity were measured. Samples were analyzed for selected nutrients, selected bacteria, chlorophyll a, and suspended sediment. Continuous in-stream water-quality monitors were installed at two gaging stations to measure specific conductance, pH, water temperature, dissolved oxygen, and turbidity.

  17. Rural Land Use in the Monongahela River Basin. [Agricultural Experiment Station] Bulletin 641.

    ERIC Educational Resources Information Center

    Akintola, Jacob; And Others

    In order to determine rural land use in the Monongahela River Basin, 11,528 landowners, controlling 40 percent of 10 contiguous counties in north-central West Virginia and constituting 19 percent of the rural population, were surveyed. Data derived from 892 questionnaire responses were analyzed in terms of past, present, and future land use; land…

  18. Big Bend National Park, TX, USA, Mexico

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Sierra del Carmen of Mexico, across the Rio Grande River from Big Bend National Park, TX, (28.5N, 104.0W) is centered in this photo. The Rio Grande River bisects the scene; Mexico to the east, USA to the west. The thousand ft. Boquillas limestone cliff on the Mexican side of the river changes colors from white to pink to lavender at sunset. This severely eroded sedimentary landscape was once an ancient seabed later overlaid with volcanic activity.

  19. Characteristics of sediment data and annual suspended-sediment loads and yields for selected lower Missouri River mainstem and tributary stations, 1976-2008

    USGS Publications Warehouse

    Heimann, David C.; Rasmussen, Patrick P.; Cline, Teri L.; Pigue, Lori M.; Wagner, Holly R.

    2010-01-01

    Suspended-sediment data from 18 selected surface-water monitoring stations in the lower Missouri River Basin downstream from Gavins Point Dam were used in the computation of annual suspended-sediment and suspended-sand loads for 1976 through 2008. Three methods of suspended-sediment load determination were utilized and these included the subdivision method, regression of instantaneous turbidity with suspended-sediment concentrations at selected stations, and regression techniques using the Load Estimator (LOADEST) software. Characteristics of the suspended-sediment and streamflow data collected at the 18 monitoring stations and the tabulated annual suspended-sediment and suspended-sand loads and yields are presented.

  20. Orientation variation of dayside auroral arc alignments obtained from all-sky observation at yellow river station, Svalbard

    NASA Astrophysics Data System (ADS)

    Qiu, Qi; Yang, Hui-Gen; Lu, Quan-Ming; Hu, Ze-Jun; Han, De-Sheng; Wang, Qian

    2016-05-01

    The orientations of dayside auroral arc alignments were calculated for over 40,000 images from all-sky observation at Yellow River Station, Svalbard. For each arc, its "orientation" and "tilt" are defined as the angle the arc alignment makes with the dusk-dawn direction and the local east-west direction, respectively. The mean arc orientation increases linearly with the increasing magnetic local time (MLT). There is a reversal point of the arc tilt located at near 10.5 MLT. Compared with the mean orientation, auroral arc alignment tilts to morning side in the higher latitude and tilts to evening side in the lower latitude in the prenoon sector, whereas it is the opposite in the postnoon sector. We further studied the effects of the interplanetary magnetic field (IMF) on the location of the arc tilt reversal point. We found that the reversal position shifts toward the midday for negative By.

  1. Reversal bending fatigue testing

    SciTech Connect

    Wang, Jy-An John; Wang, Hong; Tan, Ting

    2014-10-21

    Embodiments for apparatuses for testing reversal bending fatigue in an elongated beam are disclosed. Embodiments are configured to be coupled to first and second end portions of the beam and to apply a bending moment to the beam and create a pure bending condition in an intermediate portion of the beam. Embodiments are further configured to cyclically alternate the direction of the bending moment applied to the beam such that the intermediate portion of the beam cyclically bends in opposite directions in a pure bending condition.

  2. Innovation in monitoring: The U.S. Geological Survey Sacramento–San Joaquin River Delta, California, flow-station network

    USGS Publications Warehouse

    Burau, Jon; Ruhl, Cathy; Work, Paul

    2016-01-01

    The U.S. Geological Survey (USGS) installed the first gage to measure the flow of water into California’s Sacramento–San Joaquin River Delta from the Sacramento River in the late 1800s. Today, a network of 35 hydro-acoustic meters measure flow throughout the delta. This region is a critical part of California’s freshwater supply and conveyance system. With the data provided by this flow-station network—sampled every 15 minutes and updated to the web every hour—state and federal water managers make daily decisions about how much freshwater can be pumped for human use, at which locations, and when. Fish and wildlife scientists, working with water managers, also use this information to protect fish species affected by pumping and loss of habitat. The data are also used to help determine the success or failure of efforts to restore ecosystem processes in what has been called the “most managed and highly altered” watershed in the country.

  3. Combining a spatial model with geochemical tracers and river station data to construct a catchment sediment budget

    NASA Astrophysics Data System (ADS)

    Rustomji, Paul; Caitcheon, Gary; Hairsine, Peter

    2008-01-01

    Information about diffuse pollutant sources in river catchments and the processes responsible for their generation is often obtained using geochemical tracing, in-stream monitoring, or process based modeling. Yet these methods are rarely combined. In this study, we combine these three methods to produce a catchment sediment budget for the Lake Burragorang catchment in Australia. The physically based process model SedNet was modified using local catchment data to constrain predicted hillslope erosion rates in forested areas, the rate and texture of sediment supply from gully erosion, and the predicted floodplain deposition rates. The model's capacity to match the geochemical tracer (both spatial source and erosion process) data and gauging station load data improved markedly. Hillslope erosion, primarily in the steeper, mainly forested areas near the reservoir, is identified by the model as the main source of sediment delivered to Lake Burragorang. The contribution from gully and river bank erosion is comparatively small, though gully erosion can be locally dominant. This result is consistent with the tracer data. Utilizing multiple independent data sets allows for a more rigorous evaluation of model performance and, it is argued, increases the likelihood that the model is correctly representing the main components of the catchment's sediment budget. The identification of diffuse sediment sources in other catchments can clearly benefit from combining a range of observational data with a structured model evaluation process.

  4. Determination of base-flow characteristics at selected streamflow-gaging stations on the Mad River, Ohio

    USGS Publications Warehouse

    Koltun, G.F.

    1995-01-01

    This report describes the results of a study to estimate characteristics of base flow and sustained ground-water discharge at five streamflow-gaging stations on the Mad River in Ohio. The five streamflow-gaging stations are located at Zanesfield, near Urbana, at St. Paris Pike (at Eagle City), near Springfield, and near Dayton. The median of the annual-mean base flows, determined by means of hydrograph separation, ranged from 0.64 (ft3/s)/mi2 (cubic feet per second per square mile) at Zanesfield to 0.74 (ft3/s)/mi2 at St. Paris Pike. The median percentage of annual total streamflow attributed to base flow ranged from 61.8 percent at Zanesfield to 76.1 percent near Urbana. Estimates of an upper limit (or threshold) at which base flows can be considered to be composed predominately of sustained ground-water discharge were made by constructing and analyzing base- flow-duration curves. The sustained ground-water discharges (base flows less than or equal to the estimated sustained ground-water-discharge thresholds) are assumed to originate from ground-water- flow systems that are minimally affected by seasonal climatic changes. The median sustained ground- water discharge ranged from 0.11 (ft3/s)/mi2 at Zanesfield to 0.26 (ft3/s)/mi2 at St. Paris Pike (at Eagle City) and near Springfield. The median sustained ground-water discharge, expressed as a percentage of the median annual-mean base flow, ranged from 17.2 percent at Zanesfield to 38.6 percent near Springfield.

  5. A Current and Retrospective Landscape-Level C Budget for the Fluxnet-Canada Coastal British Columbia Station (Oyster River).

    NASA Astrophysics Data System (ADS)

    Trofymow, J. A.; Stinson, G.; Kurz, W.

    2006-12-01

    A retrospective carbon (C ) budget for the Fluxnet-Canada coastal BC Station (5 x 5 km Oyster River Area) for the period 1920 to 2005 was developed using the spatially-explicit version of the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3). CBM-CFS3 is an inventory-based C budget modeling tool that has been used to simulate forest C dynamics at national, regional, and operational scales. A current (circa 2000) forest inventory map for the Oyster River Area was compiled using data provided by forest companies (TimberWest and Island Timberlands). This inventory was overlaid with historic disturbance maps and orthophotographs to generate a coverage of forest cover polygons with unique disturbance histories. A 1920 timber cruise map was then used to help estimate the volume, cover type, and age of the forest in each polygon in 1920. Data were loaded into the CBM-CFS3 initialization routine and the model was then used to simulate the forest dynamics and C budget for the 85-year period. The C budget of the Oyster River Area is strongly tied to its disturbance history. In 1920, old-growth forest covered the majority of the study area and net C flux was neutral or small. In the 1930's and 40's, ground fires, clear-cut harvesting (using railroad logging), and slash burning resulted in a significant loss of biomass C and a substantial flux of C into dead organic matter, the atmosphere, and wood product pools (area net average C loss 5 - 20 Mg C/ha/yr). A gradual recovery of ecosystem C stocks followed this period of high disturbance activity but the area remained a significant C source, and did not become a net C sink until well into the 1950's. From 1960 through 1987 disturbance was minimal and the area remained a C sink (area average net uptake 2 - 6 Mg C/ha/yr). As harvesting of the second-growth forest began in the late 1980's, the C budget of the area was once again dominated by disturbances, albeit buffered by ongoing C uptake by living biomass in the

  6. Comparison of oxide- and metal-core behavior during CRBRP (Clinch River Breeder Reactor Plant) station blackout

    SciTech Connect

    Polkinghorne, S T; Atkinson, S A

    1986-01-01

    A resurrected concept that could significantly improve the inherently safe response of Liquid-Metal cooled Reactors (LMRs) during severe undercooling transients is the use of metallic fuel. Analytical studies have been reported on for the transient behavior of metal-fuel cores in innovative, inherently safe LMR designs. This paper reports on an analysis done, instead, for the Clinch River Breeder Reactor Plant (CRBRP) design with the only innovative change being the incorporation of a metal-fuel core. The SSC-L code was used to simulate a protected station blackout accident in the CRBRP with a 943 MWt Integral Fast Reactor (IFR) metal-fuel core. The results, compared with those for the oxide-fueled CRBRP, show that the margin to boiling is greater for the IFR core. However, the cooldown transient is more severe due to the faster thermal response time of metallic fuel. Some additional calculations to assess possible LMR design improvements (reduced primary system pressure losses, extended flow coastdown) are also discussed. 8 refs., 13 figs., 2 tabs.

  7. Hydrogeology of the Piney Point-Nanjemoy, Aquia, and Upper Patapsco Aquifers, Naval Air Station Patuxent River and Webster Outlying Field, St. Marys County, Maryland, 2000-06

    USGS Publications Warehouse

    Klohe, Cheryl A.; Kay, Robert T.

    2007-01-01

    Recent and projected population growth in southern Maryland continues to bring ground-water-quality and quantity issues to the forefront. Lithologic, borehole geophysical, water-level, and water-use data were compiled and interpreted to revise understanding of the hydrogeologic framework of the Piney Point-Nanjemoy, Aquia, and Upper Patapsco aquifers in southern Maryland, with emphasis on the Naval Air Station Patuxent River and Webster Outlying Field. Understanding of the hydrogeologic framework for the Upper Patapsco aquifer also has been revised based on the results of aquifer testing and water-quality sampling of two wells. The Piney Point-Nanjemoy aquifer is 50 to 70 feet thick, with a top altitude of 213 to 260 feet below the North American Vertical Datum of 1988 and a hydraulic conductivity of 2 feet per day at Naval Air Station Patuxent River and Webster Outlying Field. Ground-water withdrawals from the Piney Point-Nanjemoy aquifer have been minimal since 1999 and water levels in the aquifer have not changed substantially since the 1950s. An overall decline of about 2.5 feet has been observed since 1997, however. The Aquia aquifer is 100 to 145 feet thick, with a top altitude of approximately 450 feet below the North American Vertical Datum of 1988 and a hydraulic conductivity of 6 to 10 feet per day at Naval Air Station Patuxent River. The Aquia aquifer is approximately 50 feet thick, with a top altitude of 470 feet below sea level and a hydraulic conductivity of 6 to 10 feet per day at Webster Outlying Field. Water levels in the Aquia aquifer declined in response to increased withdrawals from the aquifer from the early 1940s through about 2000 at Naval Air Station Patuxent River and Webster Outlying Field, but have been generally stable from about 1999 through April 2006. The Upper Patapsco aquifer at the Naval Air Station Patuxent River and Webster Outlying Field consists of layers of sand interbedded with layers of clay that total over 200 feet in

  8. Scaling the Geomorphic and Ecological Consequences of Contemporary Climate Change Within the Salmon River Watershed, Central Idaho: A View From Taylor Ranch Field Station

    NASA Astrophysics Data System (ADS)

    Crosby, B. T.; Baxter, C. V.

    2008-12-01

    Established in 1970 by the University of Idaho, Taylor Ranch Field Station is located in the Frank Church Wilderness of No Return, along Big Creek, a 1445 km2 tributary to the Middle Fork of the Salmon River. The field station has provided a stable center for terrestrial and aquatic ecological studies within the Salmon River for almost 40 years. Dr. Wayne Minshall began monitoring aquatic ecology indices at numerous sites in the Salmon River basin in the late 1970's. This rare continuum of roughly 30 years of field data can be coupled with publically available hydrologic, geomorphic and meteorological data sets to reveal a rich record of how recent demonstrable changes in climate have affected this wilderness watershed. As a consequence of improved access and automated and telemetered sensors of water quality and quantity, contemporary studies continue through out the watershed at an increasing temporal and spatial resolution. The impetuous is upon current researchers to understand both the role of the basin as a major water source to the Snake and Columbia River systems and also the function of the basin as ideal habitat for threatened native fish. Beyond these applied questions that directly impact management decisions, the pristine nature of much of the Salmon River basin also favors studies of fundamental feedbacks between the physical and biological systems. These interdisciplinary studies are augmented by increasing collections of high resolution spatial data sets such as Hyperspectral Imagery, Distributed Sensor Networks and LiDAR topography. We present a study that explicitly examines the feedbacks between wildfire, sediment production, basin hydrology and aquatic ecosystem function. Because the tributaries to the Salmon River span discrete ranges in elevation across the snow- to rainfall-dominated hydrologic regimes, these studies reveal how sensitive different portions of the Salmon River system are to projected changes in temperature. Depending on the

  9. GENERAL VIEW ROUTE OF BEND FEED CANAL FLUME #4 REPLACEMENT ...

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

    GENERAL VIEW ROUTE OF BEND FEED CANAL FLUME #4 REPLACEMENT SIPHON FROM WEST BANK TUMALO CREEK. LOOKING EAST - Tumalo Irrigation District, Tumalo Project, West of Deschutes River, Tumalo, Deschutes County, OR

  10. VIEW OF BEND FEED CANAL FLUME #4 REPLACEMENT SIPHON OUTLET ...

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

    VIEW OF BEND FEED CANAL FLUME #4 REPLACEMENT SIPHON OUTLET STRUCTURE ON WEST BANK OF TUMALO CREEK. LOOKING EAST - Tumalo Irrigation District, Tumalo Project, West of Deschutes River, Tumalo, Deschutes County, OR

  11. Hydrodynamic Simulations of Physical Aquatic Habitat Availability for Pallid Sturgeon in the Lower Missouri River, at Yankton, South Dakota, Kenslers Bend, Nebraska, Little Sioux, Iowa, and Miami, Missouri, 2006-07

    USGS Publications Warehouse

    Jacobson, Robert B.; Johnson, Harold E., III; Dietsch, Benjamin J.

    2009-01-01

    The objective of this study was to assess the sensitivity of habitat availability in the Lower Missouri River to discharge variation, with emphasis on habitats that might support spawning of the endangered pallid sturgeon. We constructed computational hydrodynamic models for four reaches that were selected because of evidence that sturgeon have spawned in them. The reaches are located at Miami, Missouri (river mile 259.6-263.5), Little Sioux, Iowa (river mile 669.6-673.5), Kenslers Bend, Nebraska (river mile 743.9-748.1), and Yankton, South Dakota reach (river mile 804.8-808.4). The models were calibrated for a range of measured flow conditions, and run for a range of discharges that might be affected by flow modifications from Gavins Point Dam. Model performance was assessed by comparing modeled and measured water velocities. A selection of derived habitat units was assessed for sensitivity to hydraulic input parameters (drag coefficient and lateral eddy viscosity). Overall, model results were minimally sensitive to varying eddy viscosity; varying lateral eddy viscosity by 20 percent resulted in maximum change in habitat units of 5.4 percent. Shallow-water habitat units were most sensitive to variation in drag coefficient with 42 percent change in unit area resulting from 20 percent change in the parameter value; however, no habitat unit value changed more than 10 percent for a 10 percent variation in drag coefficient. Sensitivity analysis provides guidance for selecting habitat metrics that maximize information content while minimizing model uncertainties. To assess model sensitivities arising from topographic variation from sediment transport on an annual time scale, we constructed separate models from two complete independent surveys in 2006 and 2007. The net topographic change was minimal at each site; the ratio of net topographic change to water volume in the reaches at 95 percent exceedance flow was less than 5 percent, indicating that on a reach

  12. A statistical study of dayside diffuse aurora observed at Yellow River Station in Ny-Ålesund, Svalbard

    NASA Astrophysics Data System (ADS)

    Han, D.; Hu, Z.; Hu, H.; Yang, H.; Huang, D. H.; Chen, X.

    2014-12-01

    Chinese Yellow River Station (YRS), at Ny-Alesund, Svalbard is one of the few stations that can make longtime optical auroral observation at the cusp latitude in the dayside during the boreal winter season on the Earth. Since November 2003, an optical observation system consisting of three identical all-sky imagers supplied with the narrow band filters centered at 427.8, 557.5 and 630.0nm, has been installed at YRS, and the continuous observations providing us with an unprecedented opportunity to investigate some new properties of dayside aurora. Optical diffuse auroras are normally observed at the sub-aurora latitude in nightside on the ground. However, by using 7-year continuous observations obtained at YRS, we found that the diffuse auroras are very frequently observed on the dayside at the high latitude, i.e., near the cusp. We classified the dayside diffuse aurora into four primary categories. They are (1) Veiling Diffuse Aurora, which has no obvious morphological structure and clear boundaries, sometimes likes a thick cloud cover the entire sky, (2) Patch Diffuse Aurora, which is an aurora patch normally in ~10-100km in width and usually owns pulsating property; (3) Diffuse Arcs, which looks like an arc but is apparently different from the discrete auroral arcs in morphology, and (4) Pulsating Aurora, occurring with sparkling forms. We statistical studied how the occurrence of the four types of dayside diffuse auroras depends on the local time, magnetic activity, and solar wind conditions. We found that the occurrence of each type of dayside diffuse aurora shows a unimodal distribution with magnetic local time and their peaks are mostly appeared near the magnetic local noon. We also noted that ~92.2% of the dayside diffuse auroras is observed under low magnetic activity, i.e., Kp ≤ 3, and the dayside diffuse auroras prefer to be observed under IMF By<0 and Bz>0. Although previous studies suggested that the dayside diffuse aurora should be caused by wave

  13. 33 CFR 334.430 - Neuse River and tributaries at Marine Corps Air Station Cherry Point, North Carolina; restricted...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Marine Corps Air Station Cherry Point, North Carolina; restricted area and danger zone. 334.430 Section... Air Station Cherry Point, North Carolina; restricted area and danger zone. (a) The restricted area... Station, Cherry Point, North Carolina, extending from the mouth of Hancock Creek to a point...

  14. 33 CFR 334.430 - Neuse River and tributaries at Marine Corps Air Station Cherry Point, North Carolina; restricted...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Marine Corps Air Station Cherry Point, North Carolina; restricted area and danger zone. 334.430 Section... Air Station Cherry Point, North Carolina; restricted area and danger zone. (a) The restricted area... Station, Cherry Point, North Carolina, extending from the mouth of Hancock Creek to a point...

  15. 33 CFR 334.430 - Neuse River and tributaries at Marine Corps Air Station Cherry Point, North Carolina; restricted...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Marine Corps Air Station Cherry Point, North Carolina; restricted area and danger zone. 334.430 Section... Air Station Cherry Point, North Carolina; restricted area and danger zone. (a) The restricted area... Station, Cherry Point, North Carolina, extending from the mouth of Hancock Creek to a point...

  16. 33 CFR 334.430 - Neuse River and tributaries at Marine Corps Air Station Cherry Point, North Carolina; restricted...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Marine Corps Air Station Cherry Point, North Carolina; restricted area and danger zone. 334.430 Section... Air Station Cherry Point, North Carolina; restricted area and danger zone. (a) The restricted area... Station, Cherry Point, North Carolina, extending from the mouth of Hancock Creek to a point...

  17. Microhole Tubing Bending Report

    DOE Data Explorer

    Oglesby, Ken

    2012-01-01

    A downhole tubing bending study was made and is reported herein. IT contains a report and 2 excel spreadsheets to calculate tubing bending and to estimate contact points of the tubing to the drilled hole wall (creating a new support point).

  18. Discovering Gee's Bend Quilts

    ERIC Educational Resources Information Center

    Johnson, Ann

    2008-01-01

    Gee's Bend is a small community near Selma, Alabama where cotton plantations filled the land before the Civil War. After the war, the freed slaves of the plantations worked as tenant farmers and founded an African-American community. In 2002, the women of this community brought international attention and acclaim to Gee's Bend through the art of…

  19. Ozone and fine particle in the western Yangtze River Delta: an overview of 1-yr data at the SORPES station

    NASA Astrophysics Data System (ADS)

    Ding, A. J.; Fu, C. B.; Yang, X. Q.; Sun, J. N.; Zheng, L. F.; Xie, Y. N.; Herrmann, E.; Petäjä, T.; Kerminen, V.-M.; Kulmala, M.

    2013-01-01

    This work presents an overview of 1-yr measurements of ozone (O3) and fine particular matter (PM2.5) and related trace gases at a recently developed regional background site, the Station for Observing Regional Processes of the Earth System (SORPES), in the western part of the Yangtze River Delta (YRD) in East China. O3 and PM2.5 showed distinguished seasonal cycles but with contrast patterns: O3 reached a maximum in warm seasons but PM2.5 in cold seasons. Correlation analysis suggests a VOC-sensitive regime for O3 chemistry and also indicates a substantial formation of secondary aerosols under conditions of high O3 in summer. Compared with the National Ambient Air Quality Standards in China, our measurements report 15 days of O3 exceedance and 148 days of PM2.5 exceedance during the 1-yr period, suggesting a severe air pollution situation in this region. Case studies for typical O3 and PM2.5 episodes demonstrated that these episodes were generally associated with an air mass transport pathway over the mid-YRD, i.e. along the Nanjing-Shanghai axis with its city clusters, and showed that synoptic weather played an important role in air pollution, especially for O3. Agricultural burning activities caused high PM2.5 and O3 pollution during harvest seasons, especially in June. A calculation of potential source contributions based on Lagrangian dispersion simulations suggests that emissions from the YRD contributed to over 70% of the O3 precursor CO, with a majority from the middle-YRD. North-YRD and the North China Plain are the main contributors to PM2.5 pollution in this region, especially for the burning episode days. This work shows an important environmental impact from industrialization and urbanization in the YRD region, and suggests an urgent need for improving air quality in these areas through collaborative control measures among different administrative regions.

  20. Ozone and fine particle in the western Yangtze River Delta: an overview of 1 yr data at the SORPES station

    NASA Astrophysics Data System (ADS)

    Ding, A. J.; Fu, C. B.; Yang, X. Q.; Sun, J. N.; Zheng, L. F.; Xie, Y. N.; Herrmann, E.; Nie, W.; Petäjä, T.; Kerminen, V.-M.; Kulmala, M.

    2013-06-01

    This work presents an overview of 1 yr measurements of ozone (O3) and fine particular matter (PM2.5) and related trace gases at a recently developed regional background site, the Station for Observing Regional Processes of the Earth System (SORPES), in the western part of the Yangtze River Delta (YRD) in eastern China. Ozone and PM2.5 showed strong seasonal cycles but with contrast patterns: O3 reached a maximum in warm seasons but PM2.5 in cold seasons. Correlation analysis suggests a VOC-sensitive regime for O3 chemistry and a formation of secondary aerosols under conditions of high O3 in summer. Compared with the National Ambient Air Quality Standards in China, our measurements report 15 days of O3 exceedance and 148 days of PM2.5 exceedance during the 1 yr period, suggesting a severe air pollution situation in this region. Case studies for typical O3 and PM2.5 episodes demonstrated that these episodes were generally associated with an air mass transport pathway over the mid-YRD, i.e., along the Nanjing-Shanghai axis with its city clusters, and showed that synoptic weather played an important role in air pollution, especially for O3. Agricultural burning activities caused high PM2.5 and O3 pollution during harvest seasons, especially in June. A calculation of potential source contributions based on Lagrangian dispersion simulations suggests that emissions from the YRD contributed to over 70% of the O3 precursor CO, with a majority from the mid-YRD. North-YRD and the North China Plain are the main contributors to PM2.5 pollution in this region. This work shows an important environmental impact from industrialization and urbanization in the YRD region, and suggests an urgent need for improving air quality in these areas through collaborative control measures among different administrative regions.

  1. Analysis of Flood-Magnitude and Flood-Frequency Data for Streamflow-Gaging Stations in the Delaware and North Branch Susquehanna River Basins in Pennsylvania

    USGS Publications Warehouse

    Roland, Mark A.; Stuckey, Marla H.

    2007-01-01

    The Delaware and North Branch Susquehanna River Basins in Pennsylvania experienced severe flooding as a result of intense rainfall during June 2006. The height of the flood waters on the rivers and tributaries approached or exceeded the peak of record at many locations. Updated flood-magnitude and flood-frequency data for streamflow-gaging stations on tributaries in the Delaware and North Branch Susquehanna River Basins were analyzed using data through the 2006 water year to determine if there were any major differences in the flood-discharge data. Flood frequencies for return intervals of 2, 5, 10, 50, 100, and 500 years (Q2, Q5, Q10, Q50, Q100, and Q500) were determined from annual maximum series (AMS) data from continuous-record gaging stations (stations) and were compared to flood discharges obtained from previously published Flood Insurance Studies (FIS) and to flood frequencies using partial-duration series (PDS) data. A Wilcoxon signed-rank test was performed to determine any statistically significant differences between flood frequencies computed from updated AMS station data and those obtained from FIS. Percentage differences between flood frequencies computed from updated AMS station data and those obtained from FIS also were determined for the 10, 50, 100, and 500 return intervals. A Mann-Kendall trend test was performed to determine statistically significant trends in the updated AMS peak-flow data for the period of record at the 41 stations. In addition to AMS station data, PDS data were used to determine flood-frequency discharges. The AMS and PDS flood-frequency data were compared to determine any differences between the two data sets. An analysis also was performed on AMS-derived flood frequencies for four stations to evaluate the possible effects of flood-control reservoirs on peak flows. Additionally, flood frequencies for three stations were evaluated to determine possible effects of urbanization on peak flows. The results of the Wilcoxon signed

  2. Application of continuous seismic-reflection techniques to delineate paleochannels beneath the Neuse River at US Marine Corps Air Station, Cherry Point, North Carolina

    USGS Publications Warehouse

    Cardinell, Alex P.

    1999-01-01

    A continuous seismic-reflection profiling survey was conducted by the U.S. Geological Survey on the Neuse River near the Cherry Point Marine Corps Air Station during July 7-24, 1998. Approximately 52 miles of profiling data were collected during the survey from areas northwest of the Air Station to Flanner Beach and southeast to Cherry Point. Positioning of the seismic lines was done by using an integrated navigational system. Data from the survey were used to define and delineate paleochannel alignments under the Neuse River near the Air Station. These data also were correlated with existing surface and borehole geophysical data, including vertical seismic-profiling velocity data collected in 1995. Sediments believed to be Quaternary in age were identified at varying depths on the seismic sections as undifferentiated reflectors and lack the lateral continuity of underlying reflectors believed to represent older sediments of Tertiary age. The sediments of possible Quaternary age thicken to the southeast. Paleochannels of Quaternary age and varying depths were identified beneath the Neuse River estuary. These paleochannels range in width from 870 feet to about 6,900 feet. Two zones of buried paleochannels were identified in the continuous seismic-reflection profiling data. The eastern paleochannel zone includes two large superimposed channel features identified during this study and in re-interpreted 1995 land seismic-reflection data. The second paleochannel zone, located west of the first paleochannel zone, contains several small paleochannels near the central and south shore of the Neuse River estuary between Slocum Creek and Flanner Beach. This second zone of channel features may be continuous with those mapped by the U.S. Geological Survey in 1995 using land seismic-reflection data on the southern end of the Air Station. Most of the channels were mapped at the Quaternary-Tertiary sediment boundary. These channels appear to have been cut into the older sediments

  3. Groundwater quality and occurrence and distribution of selected constituents in the Aquia and Upper Patapsco aquifers, Naval Air Station Patuxent River, St. Mary's County, Maryland, July 2008

    USGS Publications Warehouse

    Dieter, Cheryl A.; Campo, Kimberly W.; Baker, Anna C.

    2012-01-01

    The Naval Air Station Patuxent River in southern Maryland has continued to expand in the first decade of the 21st century, contributing to rapid population growth in the surrounding area. The increase in population has caused State and County water managers and others to be concerned about the impact of population growth on the quantity and quality of groundwater supplies. The U.S. Geological Survey has been investigating the groundwater resources of the air station since 1998. As part of that ongoing investigation, groundwater was sampled in 2008 in six wells in the Aquia aquifer and two wells in the Upper Patapsco aquifer in the vicinity of Naval Air Station Patuxent River and Webster Outlying Field. Groundwater samples were analyzed for basic chemistry (field parameters, major ions, and nutrients) as well as several water-quality issues of concern including the occurrence of arsenic and tungsten, and saltwater intrusion. The results of the 2008 groundwater-quality sampling indicate that the overall quality of groundwater in the Aquia aquifer has not changed since 1943; data are too limited to determine if groundwater quality has changed in the Upper Patapsco aquifer. At one well in the Aquia aquifer, the arsenic concentration exceeded the U.S. Environmental Protection Agency standard for drinking water. Arsenic was not detected in samples from the Upper Patapsco aquifer. Tungsten concentrations were detected at low concentrations near the laboratory reporting level in all eight samples. There was no evidence of saltwater intrusion in any of the wells.

  4. On the 5D Extra-Force according to Basini Capozziello Ponce De Leon Formalism and five important features: Kar Sinha Gravitational Bending of Light, Chung Freese Superluminal Behaviour, Maartens Clarkson Black Strings, experimental measures of Extra Dimensions on board International Space Station (ISS) and the existence of the Particle Z due to a higher dimensional spacetime

    NASA Astrophysics Data System (ADS)

    Loup, Fernando

    2006-10-01

    We use the Conformal Metric as described in Kar Sinha work on Gravitational Bending of Light in a 5 D Spacetime to recompute the equations of the 5 D Force in Basini Capozziello Ponce De Leon Formalism and we arrive at a result that possesses some advantages. The equations of the Extra Force as proposed by Ponce De Leon are now more elegant in Conformal Formalism and many algebraic terms can be simplified or even suppressed. Also we recompute the Kar Sinha Gravitational Bending of Light affected by the presence of the Extra Dimension and analyze the Superluminal Chung Freese Features of this Formalism describing the advantages of the Chung Freese BraneWorld when compared to other Superluminal spacetime metrics (e.g. Warp Drive) and we describe why the Extra Dimension is invisible and how the Extra Dimension could be made visible at least in theory. We also examine the Maartens Clarkson Black Holes in 5 D (Black Strings) coupled to massive Kaluza Klein graviton modes predicted by Extra Dimensions theories and we study experimental detection of Extra Dimensions on-board LIGO and LISA Space Telescopes. We also propose the use of International Space Station (ISS) to measure the additional terms (resulting from the presence of Extra Dimensions) in the Kar Sinha Gravitational Bending of Light in Outer Space to verify if we really lives in a Higher Dimensional Spacetime. Also we demonstrate that Particle Z can only exist if the 5 D spacetime exists.

  5. An Extensive Survey of Dayside Diffuse Aurora (DDA) Based on Optical Observations at Yellow River Station (YRS)

    NASA Astrophysics Data System (ADS)

    Desheng, H.

    2015-12-01

    By using 7 years optical auroral observations obtained at Yellow River Station at Ny-Alesund, Svalbard, we performed the first extensive survey for the dayside diffuse auroras (DDAs) and acquired observational results as follows. (1) The DDAs can be classified into 2 broad categories, i.e., unstructured and structured DDAs. The unstructured DDAs are mainly distributed in morning and afternoon, but the structured DDAs predominantly occurred around the magnetic local noon (MLN). (2) The unstructured DDAs observed in morning and afternoon present obviously different properties. The afternoon ones are much stable and seldom show pulsating property. (3) The DDAs are more easily observed under geomagnetically quiet times. (4) The structured DDAs mainly show patchy, stripy, and irregular forms, and are often pulsating and drifting. The drifting directions are mostly westward (with speed ~5 km/s), but there are cases showing eastward or poleward drifting. (5) The stripy DDAs are exclusively observed near the MLN and, most importantly, their alignments are confirmed to be consistent with the direction of ionospheric convection near the MLN. (6) A new auroral form, called throat aurora, is found to be developed from the stripy DDAs. Based on the observational results and previous studies, we proposed our explanations to the DDAs. We suggest that the unstructured DDAs observed in the morning are extensions of the nightside diffuse aurora to the dayside, but that observed in the afternoon are predominantly caused by proton precipitations. The structured DDAs occurred near the MLN are caused by interactions of cold plasma structures, which are supposed to be originated from the ionospheric outflows or plasmaspheric drainage plumes, with hot electrons from the plasma sheet. We suppose that the cold plasma structures for producing the patchy DDAs are in lumpy and are more likely from the plasmaspheric drainage plumes. The cold plasm structure for producing the stripy DDAs should

  6. Simulation of Ground-Water Flow and Optimization of Withdrawals from Aquifers at the Naval Air Station Patuxent River, St. Mary's County, Maryland

    USGS Publications Warehouse

    Dieter, Cheryl A.; Fleck, William B.

    2008-01-01

    Potentiometric surfaces in the Piney Point-Nanjemoy, Aquia, and Upper Patapsco aquifers have declined from 1950 through 2000 throughout southern Maryland. In the vicinity of Lexington Park, Maryland, the potentiometric surface in the Aquia aquifer in 2000 was as much as 170 feet below sea level, approximately 150 feet lower than estimated pre-pumping levels before 1940. At the present rate, the water levels will have declined to the regulatory allowable maximum of 80 percent of available drawdown in the Aquia aquifer by about 2050. The effect of the withdrawals from these aquifers by the Naval Air Station Patuxent River and surrounding users on the declining potentiometric surface has raised concern for future availability of ground water. Growth at Naval Air Station Patuxent River may increase withdrawals, resulting in further drawdown. A ground-water-flow model, combined with optimization modeling, was used to develop withdrawal scenarios that minimize the effects (drawdown) of hypothetical future withdrawals. A three-dimensional finite-difference ground-water-flow model was developed to simulate the ground-water-flow system in the Piney Point-Nanjemoy, Aquia, and Upper Patapsco aquifers beneath the Naval Air Station Patuxent River. Transient and steady-state conditions were simulated to give water-resource managers additional tools to manage the ground-water resources. The transient simulation, representing 1900 through 2002, showed that the magnitude of withdrawal has increased over that time, causing ground-water flow to change direction in some areas. The steady-state simulation was linked to an optimization model to determine optimal solutions to hypothetical water-management scenarios. Two optimization scenarios were evaluated. The first scenario was designed to determine the optimal pumping rates for wells screened in the Aquia aquifer within three supply groups to meet a 25-percent increase in withdrawal demands, while minimizing the drawdown at a control

  7. 33 CFR 334.430 - Neuse River and tributaries at Marine Corps Air Station Cherry Point, North Carolina; restricted...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Station, Cherry Point, North Carolina, extending from the mouth of Hancock Creek to a point approximately 6,800 feet west of the mouth of Slocum Creek, and all waters of Hancock and Slocum Creeks and...

  8. Dispersion suppressors with bending

    SciTech Connect

    Garren, A.

    1985-10-01

    Dispersion suppressors of two main types are usually used. In one the cell quadrupole focussing structure is the same as in normal cells but some of the dipoles are replaced by drifts. In the other, the quadrupole strengths and/or spacings are different from those of the normal cells, but the bending is about the same as it is in the cells. In SSC designs to date, dispersion suppressors of the former type have been used, consisting of two cells with bending equivalent to one. In this note a suppressor design with normal bending and altered focussing is presented. The advantage of this scheme is that circumference is reduced. The disadvantages are that additional special quadrupoles must be provided (however, they need not be adjustable), and the maximum beta values within them are about 30% higher than the cell maxima.

  9. Right-angle slot waveguide bends with high bending efficiency.

    PubMed

    Ma, Changbao; Zhang, Qun; Van Keuren, Edward

    2008-09-15

    Two right-angle bends for nanoscale slot waveguides with high bending efficiency based on a corner mirror and different resonant cavities are presented, one with a triangular cavity and the other with a square cavity. Through two-dimensional parametric scanning of the position of the mirror and the dimension of the cavity, a maximum bending efficiency calculated using mode overlap integral (MOI) of 94.3% is achieved for the bend with the triangular cavity and 93.1% is achieved for the bend with the square cavity. Although they both have similar bending performance, the position of the mirror is different between the two cases. PMID:18794968

  10. Reconstructing meteorological time series to quantify the uncertainties of runoff simulation in the ungauged Qira River Basin using data from multiple stations

    NASA Astrophysics Data System (ADS)

    Xue, Jie; Gui, Dongwei; Lei, Jiaqiang; Feng, Xinlong; Zeng, Fanjiang; Zhou, Jie; Mao, Donglei

    2015-07-01

    The existence and development of oases in arid plain areas depends mainly on the runoff generated from alpine regions. Quantifying the uncertainties of runoff simulation under climatic change is crucial for better utilization of water resources and management of oases in arid areas. In the present study, based on the ungauged Qira River Basin in Xinjiang, China, a modified version of the Delta statistical downscaling method was applied to reconstruct the monthly mean temperature (MMT), monthly accumulated precipitation (MAP), and monthly accumulated evaporation (MAE) of two target stations. Then, the uncertainty in runoff simulation, implemented using the Three-Layered Feedforward Neural Network model with the Back-Propagation learning algorithm, was quantified. The modified Delta method reproduced the MMT, MAP, and MAE time series of the two target stations very well during the calibrated periods, and the reconstructed uncertainty ranges were small among reconstructed datasets using data from 12 observation stations. The monthly accumulated runoff simulated by the reconstructed MMT, MAP, and MAE as input variables of the model possessed unpredictable uncertainty. Although the use of multi-data ensembles in model inputs are considered an effective way to minimize uncertainties, it could be concluded that, in this case, the efficiency of such an approach was limited because of errors in the meteorological data and the deficiency of the model's structure. The uncertainty range in the runoff peak was unable to capture the actual monthly runoff. Nevertheless, this study represents a significant attempt to reproduce historical meteorological data and to evaluate the uncertainties in runoff simulation through multiple input ensembles in an ungauged basin. It can be used as reference meteorological data for researching long-term climate change and producing runoff forecasts for assessing the risk of droughts and/or floods, as well as the existence and management of plain

  11. A progress report on the Malaga Bend Experimental Salinity Alleviation Project, Eddy County, New Mexico

    USGS Publications Warehouse

    Cox, E.R.; Havens, J.S.

    1965-01-01

    At Malaga Bend on the Pecos River in Eddy County, New Mexico, a brine aquifer about 1950 feet below the stream channel has a pressure head about 10 feet above the river bed. This aquifer normally discharges about 430 tons of dissolved minerals daily into the river of which about 370 tons was sodium chloride. The Malaga Bend Experimental Salinity Alleviation Project, authorized by the U.S. Congress in 1958, Public Law 85-333,is an attempt to determine if the salinity content of the Pecos River below Malaga Bend can be decreased by reducing the inflow of saline water into the river at Malaga Bend by pumping from the brine aquifer. Construction for the project was supervised by the Bureau of Reclamation, and the collection of data and its interpretation were the responsibility cooperatively of the U. S. Geological Survey and the Pecos River Commission.

  12. Measuring graphene's bending stiffness

    NASA Astrophysics Data System (ADS)

    Blees, Melina; Barnard, Arthur; Roberts, Samantha; Kevek, Joshua W.; Ruyack, Alexander; Wardini, Jenna; Ong, Peijie; Zaretski, Aliaksandr; Wang, Siping; McEuen, Paul L.

    2013-03-01

    Graphene's unusual combination of in-plane strength and out-of-plane flexibility makes it promising for mechanical applications. A key value is the bending stiffness, which microscopic theories and measurements of phonon modes in graphite put at κ0 = 1.2 eV.1 However, theories of the effects of thermal fluctuations in 2D membranes predict that the bending stiffness at longer length scales could be orders of magnitude higher.2,3 This macroscopic value has not been measured. Here we present the first direct measurement of monolayer graphene's bending stiffness, made by mechanically lifting graphene off a surface in a liquid and observing both motion induced by thermal fluctuations and the deflection caused by gravity's effect on added weights. These experiments reveal a value κeff = 12 keV at room temperature -- four orders of magnitude higher than κ0. These results closely match theoretical predictions of the effects of thermally-induced fluctuations which effectively thicken the membrane, dramatically increasing its bending stiffness at macroscopic length scales.

  13. Two-dimensional resistivity investigation along West Fork Trinity River, Naval Air Station-Joint Reserve Base, Carswell Field, Fort Worth, Texas, October 2004

    USGS Publications Warehouse

    Shah, Sachin D.; Stanton, Gregory P.

    2006-01-01

    Naval Air Station-Joint Reserve Base Carswell Field (NAS-JRB) at Fort Worth, Tex., constitutes a government-owned, contractor-operated facility that has been in operation since 1942. Contaminants, primarily volatile organic compounds and metals, have entered the ground-water-flow system through leakage from waste-disposal sites and manufacturing processes. Ground water flows from west to east toward the West Fork Trinity River. During October 2004, the U.S. Geological Survey conducted a two-dimensional (2D) resistivity investigation at a site along the West Fork Trinity River at the eastern boundary of NAS-JRB to characterize the distribution of subsurface resistivity. Five 2D resistivity profiles were collected, which ranged from 500 to 750 feet long and extended to a depth of 25 feet. The Goodland Limestone and the underlying Walnut Formation form a confining unit that underlies the alluvial aquifer. The top of this confining unit is the top of bedrock at NAS-JRB. The bedrock confining unit is the zone of interest because of the potential for contaminated ground water to enter the West Fork Trinity River through saturated bedrock. The study involved a capacitively-coupled resistivity survey and inverse modeling to obtain true or actual resistivity from apparent resistivity. The apparent resistivity was processed using an inverse modeling software program. The results of this program were used to generate distributions (images) of actual resistivity referred to as inverted sections or profiles. The images along the five profiles show a wide range of resistivity values. The two profiles nearest the West Fork Trinity River generally showed less resistivity than the three other profiles.

  14. Hydrological variability from gauging stations and simulated SWOT data, for major French rivers over the past decades

    NASA Astrophysics Data System (ADS)

    Chevalier, Laetitia; Laignel, Benoit; Turki, Imen; Lyard, Florent; Lion, Christine

    2014-05-01

    This study was carried out in the framework of the program Surface Water and Ocean Topography (SWOT) associated to the National Center of Space Studies (CNES). Basing on discharge measurements, and simulated Surface Water and Ocean Topography (SWOT) data, we have investigated the hydrological variability of the main French rivers (Seine, Loire, Garonne and Rhône) by the use of a minimum, maximum and mean annual discharge analyses, Loess and wavelet approach (continuous wavelet analyses and wavelet coherence analyses). Results show (i) strong coherence between the four watershed discharges, varying between 73% and 92% and (ii) three different periods for hydrological variability: before 1970, between 1970 and 1990, and after 1990. From these results, simulated SWOT data and discharges are compared for these three periods using same analyses. Simulated SWOT data are obtained by re-sampling river discharges from the SWOT crossing time calculated. Simulated SWOT data can reproduce the hydrological variability of rivers despite number of SWOT passages (from two to four). These results are validated by coherence wavelet, which underlines coherence higher than 90% between simulated SWOT data and in-situ discharge. However, the results indicate that simulated SWOT data don't reproduce exactly the minimum and maximum annual discharge: (i) maximum annual SWOT data are underestimated and (ii) minimum annual SWOT data are overestimated

  15. Analysis of watersheds monitored by the U.S. Geological Survey streamflow-gaging station network in the Upper Colorado River Basin

    USGS Publications Warehouse

    Kenney, Terry A.; Buto, Susan G.; Susong, David D.

    2011-01-01

    The U.S. Geological Survey (USGS) has operated streamflow-gaging stations in 1,053 watersheds in the Upper Colorado River Basin (UCRB) since 1894. Currently, 223 of these streamgages are active. This report presents selected watershed characteristics for 10,338 watersheds in the UCRB. These watersheds are compared to the watersheds upstream of USGS streamgages to assess how well the USGS streamgage network represents the physical characteristics of the watersheds in the entire basin. To conduct this assessment, 17 watershed characteristics, including physiographic parameters, land cover types, lithology, and parameters that describe anthropogenic influence, were computed for each of the gaging station drainage basins. The set of 10,338 watersheds in the UCRB was constructed from a previously developed stream-reach network, and the same 17 basin characteristics were computed for each watershed to facilitate comparisons. The USGS streamgage watersheds and the UCRB watersheds were split into those that are currently unaffected by upstream reservoir regulation and those currently affected by upstream reservoir regulation. In general, for unregulated watersheds, the streamgage network represents the range of most basin characteristics in the watersheds of the UCRB. However, the active streamgage network for unregulated watersheds is generally lacking in representation of most basin characteristics compared with watersheds in the UCRB. At regulated locations, the streamgage network including the active network, generally represents the range of most basin characteristics well.

  16. Hydrometry's classical and Innovative methods and tools comparison for Stara river flows at Agios Germanos monitoring station in north-west Greece.

    NASA Astrophysics Data System (ADS)

    Filintas, Agathos, , Dr; Hatzigiannakis, Evagellos, , Dr; Arampatzis, George, , Dr; Ilias, Andreas; Panagopoulos, Andreas, , Dr; Hatzispiroglou, Ioannis

    2015-04-01

    The aim of the present study is a thorough comparison of hydrometry's conventional and innovative methods-tools for river flow monitoring. A case study was conducted in Stara river at Agios Germanos monitoring station (northwest Greece), in order to investigate possible deviations between conventional and innovative methods-tools on river flow velocity and discharge. For this study, two flowmeters were used, which manufac-tured in 2013 (OTT Messtechnik Gmbh, 2013), as follows: a) A conventional propeller flow velocity meter (OTT-Model C2) which is a me-chanical current flow meter with a certification of calibration BARGO, operated with a rod and a relocating device, along with a digital measuring device including an elec-tronic flow calculator, data logger and real time control display unit. The flowmeter has a measurement velocity range 0.025-4.000 m/s. b) An innovative electromagnetic flowmeter (OTT-Model MF pro) which it is con-sisted of a compact and light-weight sensor and a robust handheld unit. Both system components are designed to be attached to conventional wading rods. The electromag-netic flowmeter uses Faraday's Law of electromagnetic induction to measure the process flow. When an electrically conductive fluid flows along the meter, an electrode voltage is induced between a pair of electrodes placed at right angles to the direction of mag-netic field. The electrode voltage is directly proportional to the average fluid velocity. The electromagnetic flowmeter was operated with a rod and relocating device, along with a digital measuring device with various logging and graphical capabilities and vari-ous methods of velocity measurement (ISO/USGS standards). The flowmeter has a measurement velocity range 0.000-6.000 m/s. The river flow data were averaged over a pair measurement of 60+60 seconds and the measured river water flow velocity, depths and widths of the segments were used for the estimation of cross-section's mean flow velocity in each measured

  17. 2. VIEW OF CENTRAL BEND OF LOWER DIAGONAL NO. 1 ...

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

    2. VIEW OF CENTRAL BEND OF LOWER DIAGONAL NO. 1 DRAIN, LOOKING 2932 EAST OF NORTH. - Truckee-Carson Irrigation District, Lower Diagonal No. 1 Drain, Bounded by West Gate Road & Weapons Delivery Road, Naval Air Station Fallon, Fallon, Churchill County, NV

  18. 10. MOVABLE BED SEDIMENTATION MODELS. DOGTOOTH BEND MODEL (MODEL SCALE: ...

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

    10. MOVABLE BED SEDIMENTATION MODELS. DOGTOOTH BEND MODEL (MODEL SCALE: 1' = 400' HORIZONTAL, 1' = 100' VERTICAL), AND GREENVILLE BRIDGE MODEL (MODEL SCALE: 1' = 360' HORIZONTAL, 1' = 100' VERTICAL). - Waterways Experiment Station, Hydraulics Laboratory, Halls Ferry Road, 2 miles south of I-20, Vicksburg, Warren County, MS

  19. Extreme daily precipitation in the Northern Sierra Precipitation 8-Station index: The combined impact of landfalling atmospheric rivers and the Sierra barrier jet

    NASA Astrophysics Data System (ADS)

    Cordeira, J. M.; Ralph, F. M.; Neiman, P. J.; Hughes, M.

    2014-12-01

    The Upper Sacramento River area is vital to California's water supply, and is susceptible to major floods. Recent studies indicate that orographic precipitation in this complex terrain involves both inland penetrating atmospheric rivers (ARs) and the Sierra barrier jet (SBJ). The southerly SBJ induces orographic precipitation along south-facing slopes in the Shasta region, whereas landfalling ARs ascend up and over the statically stable SBJ and induce orographic precipitation along west-facing upper slopes in the Northern Sierra Nevada. This paper explores the hypothesis that extreme daily precipitation here is controlled by the presence of both a landfalling AR and a SBJ. Three 10-year-long (2000-2011) observational datasets are used. ARs are identified from the Neiman et al. (2008) AR catalog that uses an SSM/I satellite-based AR-detection method from Ralph et al. (2004), whereas SBJ conditions are determined from Chico, CA wind profiler data using the method from Neiman et al. (2010). Extreme daily precipitation is identified from the average of 8 rain gauges spanning the region known as the "Northern Sierra 8-Station Index." The "index" is used by water managers to assess water supply. Extreme events are defined as the 50 largest daily precipitation totals in the index for the 10-year period (the top ~1.37%). These dates in the 8-station index are compared with the catalogs of landfalling ARs and SBJs. In summary, 46 of 50 (92%) extreme daily precipitation events are associated with landfalling ARs on either the day before or the day of precipitation, whereas 45 of 50 (90%) extreme daily precipitation events are associated with SBJ conditions. 38 of 50 (76%) extreme daily precipitation events are associated with both a landfalling AR and an SBJ. The 10 days with the largest daily precipitation in the index were all associated with both a landfalling AR and an SBJ. Thus, extreme daily precipitation in Northern California is strongly controlled by the presence of

  20. Phase trombones with bending

    SciTech Connect

    Courant, E.D.; Garren, A.

    1985-10-01

    The phase shifting trombones considered up to now for SSC application consisted of sets of evenly spaced quadrupoles separated by drift spaces. One such trombone was placed between a dispersion suppressor and a crossing insertion, so that the trombone had zero dispersion. With such trombones, it is possible to change {beta}{sup *} at constant tune, or to change the tunes by several units without altering the cell phase advances in the arcs. An objection to the above type of phase trombone is that it adds to the circumference, since no bending is included. This objection may or may not be valid depending on the potential usefulness of the drift spaces in them. In this note the authors show an alternative trombone design in which dipoles are included between the quadrupoles as in the normal arc cells. Since these trombones have dispersion, they are placed at the ends of the arcs, to be followed in turn by the dispersion suppressors and crossing insertions.

  1. Evaluation of impingement losses of white perch at the Indian Point Nuclear Station and other Hudson River power plants

    SciTech Connect

    Van Winkle, W.; Barnthouse, L.W.; Kirk, B.L.; Vaughan, D.S.

    1980-06-01

    This report evaluates two independent lines of evidence concerning impingement losses of white perch at the power plants on the Hudson River. Based on regression analyses of impingement rate as an index of year-class strength versus year over the period 1972 through 1977, it is concluded that there is little evidence of a statistically significant downward trend. However, an analysis of minimum detectable differences in impingement rates indicates that a long time series of year-class strength would be required to detect even substantial reductions (e.g., 50%). Second, based on our estimates of percent reduction in year-class strength due to impingement (> 20% for the 1974 year class and >15% for the 1975 year class), it is concluded that the level of impingement impact is not acceptable a priori from the point of view of managing the white perch population. Our methodologies and results are compared with those of the utilities, and the bases for the substantial differences in estimate of impingement are discussed. Appendices are included on survival of impinged white perch, impingement rate as an index of population abundance, and ability to detect decreases in population abundance. 57 refs., 29 tabs.

  2. Concentrations and loads of cadmium, lead, and zinc measured near the peak of the 1999 snowmelt-runoff hydrographs for 42 water-quality stations, Coeur d'Alene River basin, Idaho

    USGS Publications Warehouse

    Woods, Paul F.

    2000-01-01

    The Coeur d’Alene River near Harrison transported 924 pounds of dissolved lead per day, of which 82.8 pounds came from the South Fork and 11.7 pounds from the North Fork. Only 10.2 percent of the load at Harrison was measured at the Pinehurst and Enaville stations; therefore, a substantial load of dissolved lead is being contributed downstream from the confluence of the North and South Forks.

  3. Seasonal variations in water quality of an oxbow lake in response to multiple short-time pulses of flooding (Jataí Ecological Station--Mogi-Guaçu River, Luiz Antonio, SP-Brazil).

    PubMed

    Krusche, A V; Mozeto, A A

    1999-01-01

    Mogi-Guaçu River is a six-order floodplain river in the upper Paraná River Basin, Southern Brazil. Its yearly discharge varies from a minimum of 100 m3.s-1 to a maximum of 600 m3.s-1. Diogo Lake is a shallow lake located at its floodplain within the Jataí Ecological Station (Luiz Antonio, São Paulo State) and is connected throughout the year to the river through a narrow and shallow channel. The main finding of this study is that the river hidrology controls the annual variations in lake hydrochemistry through a series of hydraulic effects related to oscillations in river discharge. Lake water quality is a resultant of differential contribution from local and regional watersheds. During the low water period, lake water quality is determined by inputs from Cafundó Creek, which drains the local watershed into the lake. Raising the river level during the rain season results in the damming of lake and culminates with the entrance of river waters into the plain. The geochemistry of waters in this system is determined by weathering of sandstones with basalt intrusions. Waters are acidic (river pH = 6.00 to 7.02 and stream-lake pH = 5.15 to 6.7) and dominant cations are Na+ and K+. Major anions are almost exclusively represented by bicarbonate and an unknown concentration of organic acid anions. The overall ionic load of these soft waters in the system is therefore very low. PMID:10683673

  4. Digital modeling of radioactive and chemical waste transport in the aquifer underlying the Snake River Plain at the National Reactor Testing Station, Idaho

    USGS Publications Warehouse

    Robertson, J.B.

    1974-01-01

    Industrial and low-level radioactive liquid wastes at the National Reactor Testing Station (NRTS) in Idaho have been disposed to the Snake River Plain aquifer since 1952. Monitoring studies have indicated that tritium and chloride have dispersed over a 15-square mile (39-square kilometer) area of the aquifer in low but detectable concentrations and have only migrated as far as 5 miles (8 kilometers) downgradient from discharge points. The movement of cationic waste solutes, particularly 90Sr and 137Cs, has been significantly retarded due to sorption phenomena, principally ion exchange. 137Cs has shown no detectable migration in the aquifer and 90Sr has migrated only about 1.5 miles (2 kilometers) from the Idaho Chemical Processing Plant (ICPP) discharge well, and is detectable over an area of only 1.5 square miles ( 4 square kilometers) of the aquifer. Digital modeling techniques have been applied successfully to the analysis of the complex waste-transport system by utilizing numerical solution of the coupled equations of groundwater motion and mass transport. The model includes the effects of convective transport, flow divergence, two-dimensional hydraulic dispersion, radioactive decay, and reversible linear sorption. The hydraulic phase of the model uses the iterative, alternating direction, implicit finite-difference scheme to solve the groundwater flow equations, while the waste-transport phase uses a modified method of characteristics to solve the solute transport equations simulated by the model. The modeling results indicate that hydraulic dispersion (especially transverse) is a much more significant influence than previously suggested by earlier studies. The model has been used to estimate future waste migration patterns for varied assumed hydrological and waste conditions up through the year 2000. The hydraulic effects of recharge from the Big Lost River have an important (but not predominant) influence on the simulated future migration patterns. For the

  5. Evaluation of machine learning tools as a statistical downscaling tool: temperatures projections for multi-stations for Thames River Basin, Canada

    NASA Astrophysics Data System (ADS)

    Goyal, Manish Kumar; Burn, Donald H.; Ojha, C. S. P.

    2012-05-01

    Many impact studies require climate change information at a finer resolution than that provided by global climate models (GCMs). This paper investigates the performances of existing state-of-the-art rule induction and tree algorithms, namely single conjunctive rule learner, decision table, M5 model tree, and REPTree, and explores the impact of climate change on maximum and minimum temperatures (i.e., predictands) of 14 meteorological stations in the Upper Thames River Basin, Ontario, Canada. The data used for evaluation were large-scale predictor variables, extracted from National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis dataset and the simulations from third generation Canadian coupled global climate model. Data for four grid points covering the study region were used for developing the downscaling model. M5 model tree algorithm was found to yield better performance among all other learning techniques explored in the present study. Hence, this technique was applied to project predictands generated from GCM using three scenarios (A1B, A2, and B1) for the periods (2046-2065 and 2081-2100). A simple multiplicative shift was used for correcting predictand values. The potential of the downscaling models in simulating predictands was evaluated, and downscaling results reveal that the proposed downscaling model can reproduce local daily predictands from large-scale weather variables. Trend of projected maximum and minimum temperatures was studied for historical as well as downscaled values using GCM and scenario uncertainty. There is likely an increasing trend for T max and T min for A1B, A2, and B1 scenarios while decreasing trend has been observed for B1 scenarios during 2081-2100.

  6. 33 CFR 334.540 - Banana River at the Eastern Range, 45th Space Wing, Cape Canaveral Air Force Station, FL...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... navigable waters of the United States, as defined at 33 CFR part 329, within the Banana River contiguous to... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Banana River at the Eastern Range... AND RESTRICTED AREA REGULATIONS § 334.540 Banana River at the Eastern Range, 45th Space Wing,...

  7. Passive, achromatic, nearly isochronous bending system

    DOEpatents

    Douglas, David R.; Yunn, Byung C.

    2004-05-18

    A particle beam bending system having a geometry that applies active bending only beyond the chord of the orbit for any momentum component. Using this bending configuration, all momentum components emerge dispersed in position only; all trajectories are parallel by construction. Combining a pair of such bends with reflective symmetry produces a bend cell that is, by construction, achromatic to all orders. By the particular choice of 45.degree. individual bends, a pair of such achromats can be used as the basis of a 180.degree. recirculation arc. Other rational fractions of a full 180.degree. bend serve equally well (e.g., 2 bends/cell.times.90.degree./bend.times.1 cell /arc; 2 bends/cell.times.30.degree./bend.times.3 cells/arc, etc), as do combinations of multiple bending numerologies (e.g., 2 bends/cell.times.22.5.degree./bend.times.2 cells+2 bends/cell.times.45.degree./bend.times.1 cell). By the choice of entry pole face rotation of the first magnet and exit pole face rotation of the second magnet (with a value to be determined from the particular beam stability requirements imposed by the choice of bending angle and beam properties to be used in any particular application), desirable focusing properties can be introduced and beam stability can be insured.

  8. INEL seismograph stations

    SciTech Connect

    Jackson, S.M.; Anderson, D.M.

    1985-10-01

    The report describes the array of five seismograph stations operated by the Idaho National Engineering Laboratory to monitor earthquake activity on and adjacent to the eastern Snake River plain. Also included is the earthquake catalog from October 1972-December 1984. 2 refs., 2 figs. (ACR)

  9. A preliminary study on the effects of combined halogenation and thermal recirculation at a coal-fired generating station

    SciTech Connect

    Schnelle, R.C.; Strimple, P.D.

    1995-06-01

    East Bend Station is a single-unit, 650 megawatt, coal-fired generating station, located at Ohio River mile 510, near Rabbit Hash, Kentucky. Zebra mussel (Dreissena polymorpha) veligers were first detected at East Bend on 23 July 1992. Since then, the station has adopted a plan for preventing the settlement of zebra mussel veligers, by utilizing a combined halogenation and thermal recirculation treatment regime. A backflush pipeline was constructed, allowing 100% of the heated service water to be recycled through the intake well. During weekly treatments, the service water return to the river is valved out and water temperature is ramped up to between 31{degrees} - 35{degrees}C. HTH (calcium hypochlorite @65% available chlorine) is then slug-fed directly into the intake well. The temperature is maintained until the chlorine residual is below detectable limits. In addition to the weekly combined treatments, the service water system is also brominated for two hours, three times weekly, to 0.5 mg/1 TRO. Treatment efficacy is monitored, using a plexiglas biobox, seeded with adult mussels obtained from a substrate monitor attached to a barge cell and submerged to a depth of 3 meters. Preliminary results show both treatments to be ineffective for adult kill, however, it is believed that any newly-settle juveniles are being killed. Intake and equipment inspections during an upcoming unit outage will provide further verification. Additional testing, using various halogenation techniques, will be conducted during 1995.

  10. Bromide, Chloride, and Sulfate Concentrations and Loads at U.S. Geological Survey Streamflow-Gaging Stations 07331600 Red River at Denison Dam, 07335500 Red River at Arthur City, and 07336820 Red River near DeKalb, Texas, 2007-09

    USGS Publications Warehouse

    Baldys, Stanley; Churchill, Christopher J.; Mobley, Craig A.; Coffman, David K.

    2010-01-01

    The U.S. Geological Survey, in cooperation with the City of Dallas Water Utilities Division, did a study to characterize bromide, chloride, and sulfate concentrations and loads at three U.S. Geological Survey streamflow-gaging stations on the reach of the Red River from Denison Dam, which impounds Lake Texoma, to the U.S. Highway 259 bridge near DeKalb, Texas. Bromide, chloride, and sulfate concentrations and loads were computed for streamflow-gaging stations on the study reach of the Red River. Continuous streamflow and specific conductance data and discrete samples for bromide, chloride, sulfate, and specific conductance were collected at three main-stem streamflow-gaging stations on the Red River: 07331600 Red River at Denison Dam near Denison, Texas (Denison Dam gage), 07335500 Red River at Arthur City, Texas (Arthur City gage), and 07336820 Red River near DeKalb, Texas (DeKalb gage). At each of these streamflow-gaging stations, discrete water-quality data were collected during January 2007-February 2009; continuous water-quality data were collected during March 2007-February 2009. Two periods of high flow resulted from floods during the study; floods during June-July 2007 resulted in elevated flow during June-September 2007 and smaller floods during March-April 2008 resulted in elevated flow during March-April 2008. Bromide, chloride, and sulfate concentrations in samples collected at the three gages decreased downstream. Median bromide concentrations ranged from 0.32 milligram per liter at the Denison Dam gage to 0.19 milligram per liter at the DeKalb gage. Median chloride concentrations ranged from 176 milligrams per liter at the Denison Dam gage to 108 milligrams per liter at the DeKalb gage, less than the 300-milligrams per liter secondary maximum contaminant level established by the Texas Commission on Environmental Quality. Median sulfate concentrations ranged from 213 milligrams per liter at the Denison Dam gage to 117 milligrams per liter at the De

  11. Bending fracture in carbon nanotubes.

    PubMed

    Kuo, Wen-Shyong; Lu, Hsin-Fang

    2008-12-10

    A novel approach was adopted to incur bending fracture in carbon nanotubes (CNTs). Expanded graphite (EG) was made by intercalating and exfoliating natural graphite flakes. The EG was deposited with nickel particles, from which CNTs were grown by chemical vapor deposition. The CNTs were tip-grown, and their roots were fixed on the EG flakes. The EG flakes were compressed, and many CNTs on the surface were fragmented due to the compression-induced bending. Two major modes of the bending fracture were observed: cone-shaped and shear-cut. High-resolution scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the crack growth within the graphene layers. The bending fracture is characterized by two-region crack growth. An opening crack first appears around the outer-tube due to the bending-induced tensile stress. The crack then branches to grow along an inclined direction toward the inner-tube due to the presence of the shear stress in between graphene layers. An inner-tube pullout with inclined side surface is formed. The onset and development of the crack in these two regions are discussed. PMID:21730690

  12. Biomorphodynamic modelling of inner bank advance in migrating meander bends

    NASA Astrophysics Data System (ADS)

    Zen, Simone; Zolezzi, Guido; Toffolon, Marco; Gurnell, Angela M.

    2016-07-01

    We propose a bio-morphodynamic model at bend cross-sectional scale for the lateral migration of river meander bends, where the two banks can migrate separately as a result of the mutual interaction between river flow, sediments and riparian vegetation, particularly at the interface between the permanently wet channel and the advancing floodplain. The model combines a non-linear analytical model for the morphodynamic evolution of the channel bed, a quasi-1D model to account for flow unsteadiness, and an ecological model describing riparian vegetation dynamics. Simplified closures are included to estimate the feedbacks among vegetation, hydrodynamics and sediment transport, which affect the morphology of the river-floodplain system. Model tests reveal the fundamental role of riparian plants in generating bio-morphological patterns at the advancing floodplain margin. Importantly, they provide insight into the biophysical controls of the 'bar push' mechanism and into its role in the lateral migration of meander bends and in the temporal variations of the active channel width.

  13. Trace gases, aerosols and their interactions with synoptic weather: An overview of in-situ measurements at the SORPES Station in the western Yangtze River Delta, China

    NASA Astrophysics Data System (ADS)

    Ding, A.; Fu, C.; Yang, X.; Petaja, T.; Kerminen, V.; Kulmala, M. T.

    2013-12-01

    This work presents an overview of 1 yr measurements of ozone (O3) and fine particular matter (PM2.5) and related trace gases at a recently developed regional background site, the Station for Observing Regional Processes of the Earth System (SORPES), in the western part of the Yangtze River Delta (YRD) in eastern China. Ozone and PM2.5 showed strong seasonal cycles but with contrast patterns: O3 reached a maximum in warm seasons but PM2.5 in cold seasons. Correlation analysis suggests a VOC-sensitive regime for O3 chemistry and a formation of secondary aerosols under conditions of high O3 in summer. Compared with the National Ambient Air Quality Standards in China, our measurements report 15 days of O3 exceedance and 148 days of PM2.5 exceedance during the 1 yr period, suggesting a severe air pollution situation in this region. A calculation of potential source contributions based on Lagrangian dispersion simulations suggests that emissions from the YRD contributed to over 70% of the O3 precursor CO, with a majority from the mid-YRD. North-YRD and the North China Plain are the main contributors to PM2.5pollution in this region. Case studies for typical O3 and PM2.5 episodes showed that synoptic weather played an important role in air pollution, especially for O3. Observation during the typical biomass burning seasons also shows clear air pollution - weather interactions. For the typical episode occurred on 10 June, 2012, the measurement suggest that the mixed agricultural burning plumes with fossil fuel combustion pollution resulted in a decrease of solar radiation by more than 70 %, of sensible heat flux over 85 %, a temperature drop by almost 10 K, and a change 10 of rainfall during daytime and nighttime. This work shows an important environmental impact from industrialization and urbanization in the YRD region, and suggests an urgent need for improving air quality in these areas through collaborative control measures among different administrative regions, and

  14. Trace gases, aerosols and their interactions with synoptic weather: An overview of in-situ measurements at the SORPES Station in the western Yangtze River Delta, China

    NASA Astrophysics Data System (ADS)

    Ding, A.; Fu, C.; Yang, X.; Petaja, T.; Kerminen, V.; Kulmala, M. T.

    2011-12-01

    This work presents an overview of 1 yr measurements of ozone (O3) and fine particular matter (PM2.5) and related trace gases at a recently developed regional background site, the Station for Observing Regional Processes of the Earth System (SORPES), in the western part of the Yangtze River Delta (YRD) in eastern China. Ozone and PM2.5 showed strong seasonal cycles but with contrast patterns: O3 reached a maximum in warm seasons but PM2.5 in cold seasons. Correlation analysis suggests a VOC-sensitive regime for O3 chemistry and a formation of secondary aerosols under conditions of high O3 in summer. Compared with the National Ambient Air Quality Standards in China, our measurements report 15 days of O3 exceedance and 148 days of PM2.5 exceedance during the 1 yr period, suggesting a severe air pollution situation in this region. A calculation of potential source contributions based on Lagrangian dispersion simulations suggests that emissions from the YRD contributed to over 70% of the O3 precursor CO, with a majority from the mid-YRD. North-YRD and the North China Plain are the main contributors to PM2.5pollution in this region. Case studies for typical O3 and PM2.5 episodes showed that synoptic weather played an important role in air pollution, especially for O3. Observation during the typical biomass burning seasons also shows clear air pollution - weather interactions. For the typical episode occurred on 10 June, 2012, the measurement suggest that the mixed agricultural burning plumes with fossil fuel combustion pollution resulted in a decrease of solar radiation by more than 70 %, of sensible heat flux over 85 %, a temperature drop by almost 10 K, and a change 10 of rainfall during daytime and nighttime. This work shows an important environmental impact from industrialization and urbanization in the YRD region, and suggests an urgent need for improving air quality in these areas through collaborative control measures among different administrative regions, and

  15. Bending rules for animal propulsion.

    PubMed

    Lucas, Kelsey N; Johnson, Nathan; Beaulieu, Wesley T; Cathcart, Eric; Tirrell, Gregory; Colin, Sean P; Gemmell, Brad J; Dabiri, John O; Costello, John H

    2014-01-01

    Animal propulsors such as wings and fins bend during motion and these bending patterns are believed to contribute to the high efficiency of animal movements compared with those of man-made designs. However, efforts to implement flexible designs have been met with contradictory performance results. Consequently, there is no clear understanding of the role played by propulsor flexibility or, more fundamentally, how flexible propulsors should be designed for optimal performance. Here we demonstrate that during steady-state motion by a wide range of animals, from fruit flies to humpback whales, operating in either air or water, natural propulsors bend in similar ways within a highly predictable range of characteristic motions. By providing empirical design criteria derived from natural propulsors that have convergently arrived at a limited design space, these results provide a new framework from which to understand and design flexible propulsors. PMID:24548870

  16. Method for uniformly bending conduits

    DOEpatents

    Dekanich, S.J.

    1984-04-27

    The present invention is directed to a method for bending metal tubing through various radii while maintaining uniform cross section of the tubing. The present invention is practical by filling the tubing to a sufficient level with water, freezing the water to ice and bending the ice-filled tubing in a cooled die to the desired radius. The use of the ice as a filler material provides uniform cross-sectional bends of the tubing and upon removal of the ice provides an uncontaminated interior of the tubing which will enable it to be used in its intended application without encountering residual contaminants in the tubing due to the presence of the filler material.

  17. Compaction managed mirror bend achromat

    DOEpatents

    Douglas, David

    2005-10-18

    A method for controlling the momentum compaction in a beam of charged particles. The method includes a compaction-managed mirror bend achromat (CMMBA) that provides a beamline design that retains the large momentum acceptance of a conventional mirror bend achromat. The CMMBA also provides the ability to tailor the system momentum compaction spectrum as desired for specific applications. The CMMBA enables magnetostatic management of the longitudinal phase space in Energy Recovery Linacs (ERLs) thereby alleviating the need for harmonic linearization of the RF waveform.

  18. Characterization of bending EAP beams

    NASA Technical Reports Server (NTRS)

    Bao, Xiaoqi; Bar-Cohen, Yoseph; Chang, Zensheu; Sherrit, Stewart

    2004-01-01

    Electroactive polymers are attractive actuation materials because of their large deformation, flexibility, and lightweight. A CCD camera system was constructed to record the curved shapes of bending during the activation of EAP films and image-processing software was developed to digitize the bending curves. A computer program was developed to solve the invese problem of cantilever EAP beams with tip position limiter. using the developed program and acquired curves without tip position limiter as well as the corresponding tip force, the EAP material properties of voltage-strain sensitivity and Young's modulus were determined.

  19. Regression Equations for Estimating Concentrations of Selected Water-Quality Constituents for Selected Gaging Stations in the Red River of the North Basin, North Dakota, Minnesota, and South Dakota

    USGS Publications Warehouse

    Williams-Sether, Tara

    2004-01-01

    The Dakota Water Resources Act, passed by the U.S. Congress on December 15, 2000, authorized the Secretary of the Interior to conduct a comprehensive study of future water-quantity and quality needs of the Red River of the North Basin in North Dakota and possible options to meet those water needs. Previous Red River of the North Basin studies conducted by the Bureau of Reclamation used streamflow and water-quality data bases developed by the U.S. Geological Survey that included data for 1931-84. As a result of the recent congressional authorization and results of previous studies by the Bureau of Reclamation, redevelopment of the streamflow and water-quality data bases with current data through 1999 are needed in order to evaluate and predict the water-quantity and quality effects within the Red River of the North Basin. This report provides updated statistical summaries of selected water-quality constituents and streamflow and the regression relations between them. Available data for 1931-99 were used to develop regression equations between 5 selected water-quality constituents and streamflow for 38 gaging stations in the Red River of the North Basin. The water-quality constituents that were regressed against streamflow were hardness (as CaCO3), sodium, chloride, sulfate, and dissolved solids. Statistical summaries of the selected water-quality constituents and streamflow for the gaging stations used in the regression equations development and the applications and limitations of the regression equations are presented in this report.

  20. Bending behavior of lapped plastic ehv cables

    SciTech Connect

    Morgan, G H; Muller, A C

    1980-01-01

    One of the factors delaying the development of lapped polymeric cables has been their reputed poor bending characteristics. Complementary programs were begun at BNL several years ago to mathematically model the bending of synthetic tape cables and to develop novel plastic tapes designed to have moduli more favorable to bending. A series of bend tests was recently completed to evaluate the bending performance of several tapes developed for use in experimental superconducting cables. The program is discussed and the results of the bend tests are summarized.

  1. Hormonal regulation of gravitropic bending

    NASA Astrophysics Data System (ADS)

    Hu, X.; Cui, D.; Xu, X.; Hu, L.; Cai, W.

    Gravitropic bending is an important subject in the research of plant Recent data support the basics of the Cholodny-Went hypothesis indicating that differential growth in gravitropism is due to redistribution of auxin to the lower sides of gravistimulated roots but little is known regarding the molecular details of such effects So we carried a series of work surround the signals induced by auxin end center We found the endogenous signaling molecules nitric oxide NO and cGMP mediate responses to gravistimulation in primary roots of soybean Glycine max Horizontal orientation of soybean roots caused the accumulation of both NO and cGMP in the primary root tip Fluorescence confocal microcopy revealed that the accumulation of NO was asymmetric with NO concentrating in the lower side of the root Auxin induced NO accumulation in root protoplasts and asymmetric NO accumulation in root tips Gravistimulation NO and auxin also induced the accumulation of cGMP a response inhibited by removal of NO or by inhibitors of guanylyl cyclase compounds that also reduced gravitropic bending Asymmetric NO accumulation and gravitropic bending were both inhibited by an auxin transport inhibitor and the inhibition of bending was overcome by treatment with NO or 8-bromo-cGMP a cell-permeable analog of cGMP These data indicate that auxin-induced NO and cGMP mediate gravitropic curvature in soybean roots From Hu et al Plant Physiol 2005 137 663-670 The asymmetric distribution of auxin plays a fundamental role in plant gravitropic bending

  2. Membrane Bending by Protein Crowding

    NASA Astrophysics Data System (ADS)

    Stachowiak, Jeanne

    2014-03-01

    From endosomes and synaptic vesicles to the cristae of the mitochondria and the annulus of the nuclear pore, highly curved membranes are fundamental to the structure and physiology of living cells. The established view is that specific families of proteins are able to bend membranes by binding to them. For example, inherently curved proteins are thought to impose their structure on the membrane surface, while membrane-binding proteins with hydrophobic motifs are thought to insert into the membrane like wedges, driving curvature. However, computational models have recently revealed that these mechanisms would require specialized membrane-bending proteins to occupy nearly 100% of a curved membrane surface, an improbable physiological situation given the immense density and diversity of membrane-bound proteins, and the low expression levels of these specialized proteins within curved regions of the membrane. How then does curvature arise within the complex and crowded environment of cellular membranes? Our recent work using proteins involved in clathrin-mediated endocytosis, as well as engineered protein-lipid interactions, has suggested a new hypothesis - that lateral pressure generated by collisions between membrane-bound proteins can drive membrane bending. Specifically, by correlating membrane bending with quantitative optical measurements of protein density on synthetic membrane surfaces and simple physical models of collisions among membrane-bound proteins, we have demonstrated that protein-protein steric interactions can drive membrane curvature. These findings suggest that a simple imbalance in the concentration of membrane-bound proteins across a membrane surface can drive a membrane to bend, providing an efficient mechanism by which essentially any protein can contribute to shaping membranes.

  3. Experiments in a high-amplitude Kinoshita meandering channel: 1. Implications of bend orientation on mean and turbulent flow structure

    NASA Astrophysics Data System (ADS)

    Abad, Jorge D.; Garcia, Marcelo H.

    2009-02-01

    Meandering rivers exhibit complex planform patterns with both upstream and downstream valley oriented meander bends. In order to describe the effects of bend orientation on long-term river evolution, it is of great importance to be able to describe bend orientation (curvature) effects on the hydrodynamics of the flow as a first approximation. Mean flow and turbulence characteristics were investigated experimentally in a periodic, asymmetric, meandering channel herein called "the Kinoshita channel". The channel planform configuration retains high-order harmonic modes. Upstream and downstream valley oriented meander bends can be studied by reversing the flow. A flat, smooth bed (without sediment) condition has been considered to avoid further complexity. Spatial distributions of mean flow (e.g., velocities) and turbulence parameters (Reynolds stresses, turbulent kinetic energy) were observed at several cross sections along the meander wavelength. Measurements show that at the bend apex, the core of maximum velocity is found near the inner bank for both planform orientations. At the same cross section, observations show that when bends are oriented upstream valley, the secondary flow is not as well developed as in the case where bends are oriented downstream valley. Furthermore, for the upstream condition the energy gradient is smaller than that for the downstream condition, suggesting that the friction (i.e., flow resistance) due to curvature is higher for the downstream-skewed condition. Implications about having upstream and downstream bends in the meandering river migration framework are also discussed herein.

  4. Bend ductility of tungsten heavy alloys

    SciTech Connect

    Gurwell, W.E.; Garnich, M.R.; Dudder, G.B.; Lavender, C.A.

    1992-11-01

    A bend ductility test is used to indicate the formability of tungsten heavy alloys sheet. The primary test bends a notchless Charpy impact specimen to a bend angle of approximately 100C. This can be augmented by a bend-completion test. Finite element modeling as well as strain-gaged bend specimens elucidate the strain distribution in the specimen as a function of material thickness and bend angle. The bend ductilities of 70%W, 807.W and 90%W alloys are characterized. As expected, decreasing thickness or tungsten content enhances bend ductility. Oxidation is not detrimental; therefore, controlled atmosphere is not required for cooling. The potentially detrimental effects of mechanical working (e.g., rolling, roller-leveling, grit blasting, and peening) and machining (e.g., cutting and sanding) are illustrated.

  5. 33 CFR 334.540 - Banana River at the Eastern Range, 45th Space Wing, Cape Canaveral Air Force Station, FL...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... navigable waters of the United States, as defined at 33 CFR part 329, within the Banana River contiguous to... advance notice. Closure of the area shall be noticed by the display of a red beacon located at...

  6. 33 CFR 334.540 - Banana River at the Eastern Range, 45th Space Wing, Cape Canaveral Air Force Station, FL...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... navigable waters of the United States, as defined at 33 CFR part 329, within the Banana River contiguous to... advance notice. Closure of the area shall be noticed by the display of a red beacon located at...

  7. 33 CFR 334.540 - Banana River at the Eastern Range, 45th Space Wing, Cape Canaveral Air Force Station, FL...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... navigable waters of the United States, as defined at 33 CFR part 329, within the Banana River contiguous to... advance notice. Closure of the area shall be noticed by the display of a red beacon located at...

  8. Design and installation of continuous flow and water qualitymonitoring stations to improve water quality forecasting in the lower SanJoaquin River

    SciTech Connect

    Quinn, Nigel W.T.

    2007-01-20

    This project deliverable describes a number ofstate-of-the-art, telemetered, flow and water quality monitoring stationsthat were designed, instrumented and installed in cooperation with localirrigation water districts to improve water quality simulation models ofthe lower San Joaquin River, California. This work supports amulti-disciplinary, multi-agency research endeavor to develop ascience-based Total Maximum Daily Load for dissolved oxygen in the SanJoaquin River and Stockton Deep Water Ship Channel.

  9. Improved Method Of Bending Concentric Pipes

    NASA Technical Reports Server (NTRS)

    Schroeder, James E.

    1995-01-01

    Proposed method for bending two concentric pipes simultaneously while maintaining void between them replaces present tedious, messy, and labor-intensive method. Array of rubber tubes inserted in gap between concentric pipes. Tubes then inflated with relatively incompressible liquid to fill gap. Enables bending to be done faster and more cleanly, and amenable to automation of significant portion of bending process on computer numerically controlled (CNC) tube-bending machinery.

  10. Bending Stiffness of Multiwall Sandwich

    NASA Technical Reports Server (NTRS)

    Blosser, M. L.

    1983-01-01

    An analytical and experimental study was carried out to understand the extensional and flexural behavior of multiwall sandwich, a metallic insulation composed of alternate layers of flat and dimpled foil. The multiwall sandwich was structurally analyzed by using several simplifying assumptions combined with a finite element analysis. The simplifying assumptions made in this analysis were evaluated by bending and tensile tests. Test results validate the assumption that flat sheets in compression do not significantly contribute to the flexural stiffness of multiwall sandwich for the multiwall geometry tested. However, calculations show that thicker flat sheets may contribute significantly to bending stiffness and cannot be ignored. Results of this analytical approach compare well with test data; both show that the extensional stiffness of the dimpled sheet in he 0 deg direction is about 30 percent of that for a flat sheet, and that in the 45 deg direction, it is about 10 percent. The analytical and experimental multiwall bending stiffness showed good agreement for the particular geometry tested.

  11. Geomorphic Effects of Engineered Log Jams in River Restoration, Middle Fork John Day River

    NASA Astrophysics Data System (ADS)

    Duffin, J.; McDowell, P. F.

    2014-12-01

    The Middle Fork of the John Day River (MFJD) Intensively Monitored Watershed in eastern Oregon is a multi-phase restoration implementation and monitoring project. MFJD is a tributary to the Colombia and is part of one of the longest free flowing rivers systems in the continental United States. It is a gravel and cobble bed river with a drainage area of 2,100 km2. The river has endured extensive channel and floodplain degradation from years of channel alteration and straightening due to human influences including dredge mining, ranching, and farming. As part of the river restoration project on the MFJD, engineered log jams have been constructed to address many of the restoration goals including creating scour pools, inhibiting bank erosion, creating and maintaining a sinuous river planform, and increasing complexity of fish habitat. There is a need for more detailed understanding on ELJ channel morphologic effects and how site-specific characteristics and differences in log jam infrastructure interact to create the in-channel features over timescales longer than a few years. This study uses detailed channel bed topographic surveys collected either with a total station or RTK-GPS technology. Geomorphic change detection techniques are utilized to monitor topographic change under and around the 26 log structures in two different river reaches over a six to seven year period The log structures are often associated with deepening of pools as desired, but also some structures show sedimentation under the structure. Differences in the patterns will be assessed based on the design, location, and specific characteristics of the log structures; variables include number and placement of logs, volume of structure, location on meander bend, and sediment sizes.

  12. Estimated loads of selected constituents from permitted and nonpermitted sources at selected surface-water-quality stations in the Musconetcong, Rockaway, and Whippany River basins, New Jersey, 1985-90

    USGS Publications Warehouse

    Price, C.V.; Schaefer, F.L.

    1995-01-01

    Surface-water-quality data from the cooperative sampling network maintained by the U.S. Geological Survey and the New Jersey Department of Environmental Protection for 1985-90 are summarized for stations in the Musconetcong, Rockaway, and Whippany River Basins. Four constituents are included in the analysis: biochemical oxygen demand (BOD), total nitrogen, total phosphorus, and total organic carbon (TOC). Contemporaneous streamflow estimates were used to calculate instream loads from constituent concentrations in water-quality samples. Loads from permitted point sources were estimated as the sum of reported loads of BOD, total nitrogen, and total phosphorus upstream from each station. TOC permitted-source loads were not estimated because point-source release data were insufficient. The relative contribution of loads from permitted sources to the total instream loads differed markedly among the basins and between upstream and downstream locations within the basins. Some of these differences can be attributed to reesrvoir effects; others are related to the presence or absence of major permitted sources upstream from water-quality stations.

  13. Annual Peak-Flow Frequency Characteristics and (or) Peak Dam-Pool-Elevation Frequency Characteristics of Dry Dams and Selected Streamflow-Gaging Stations in the Great Miami River Basin, Ohio

    USGS Publications Warehouse

    Koltun, G.F.

    2009-01-01

    This report describes the results of a study to determine frequency characteristics of postregulation annual peak flows at streamflow-gaging stations at or near the Lockington, Taylorsville, Englewood, Huffman, and Germantown dry dams in the Miami Conservancy District flood-protection system (southwestern Ohio) and five other streamflow-gaging stations in the Great Miami River Basin further downstream from one or more of the dams. In addition, this report describes frequency characteristics of annual peak elevations of the dry-dam pools. In most cases, log-Pearson Type III distributions were fit to postregulation annual peak-flow values through 2007 (the most recent year of published peak-flow values at the time of this analysis) and annual peak dam-pool storage values for the period 1922-2008 to determine peaks with recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years. For one streamflow-gaging station (03272100) with a short period of record, frequency characteristics were estimated by means of a process involving interpolation of peak-flow yields determined for an upstream and downstream gage. Once storages had been estimated for the various recurrence intervals, corresponding dam-pool elevations were determined from elevation-storage ratings provided by the Miami Conservancy District.

  14. Ecological evaluation of proposed dredged material from the Point Frazer Bend Reach, Winyah Bay, South Carolina

    SciTech Connect

    Gardiner, W.W.; Ward, J.A.; Word, J.Q.

    1995-02-01

    The port of Georgetown, South Carolina, is served by navigational channels within Winyah Bay and the lower Sampit River. Dredging is required to maintain these waterways and to facilitate normal shipping traffic. Prior to dredging, ecological evaluations must be conducted to determine the suitability of the proposed dredged material for open-ocean disposal. These evaluations are to be performed under Section 103 of the Marine Protection, Research, and, Sanctuaries Act of 1972 (MPRSA), following the testing protocols presented in Evaluation of Dredged Material Proposed for Ocean Disposal Testing Manual, hereafter referred to as the 1991 Implementation Manual. The Charleston Intensive Project is a reevaluation of sediments collected from two stations (IH-2 and IH-3) in the Frazier Point Bend reach of the Winyah Bay channel. Reference sediment was also collected from site IH-R2, just south of Hare Island. The results of physical/chemical analyses indicated that some contaminants of concern were present in test treatments representing dredged material when compared with the reference treatment IH-R2. The results of this study indicate that, based on the acute toxicity and chemical analyses, dredged material represented by these test treatments is suitable for open-ocean disposal.

  15. Geomorpho-tectonic evolution of the Jamaican restraining bend

    NASA Astrophysics Data System (ADS)

    Domínguez-González, Leomaris; Andreani, Louis; Stanek, Klaus P.; Gloaguen, Richard

    2015-01-01

    This work applies recent advances in tectonic geomorphology in order to understand the geomorphic evolution of the Jamaican restraining bend located along the Caribbean-Gonâve-North American plate boundary. We propose a classification of landscapes according to their erosional stages. The approach is mainly based on the combination of two DEM-based geomorphic indices: the hypsometric integral which highlights elevated surfaces, and the surface roughness which increases when the relief is incised by the drainage network. River longitudinal profiles were also analyzed as the drainage network responds quickly to base-level change triggered by external forcing such as tectonics. Anomalies in river profiles (knickpoints and convex segments) were mapped using stream length-gradient (SL) and normalized steepness (ksn) indices. The results provide new insights for understanding the complex evolution of the Jamaican restraining bend. Three main morphotectonic regions were identified in Jamaica: (1) the Blue Mountain-Wagwater unit located at the eastern tip of the island, (2) the Jamaican highlands plateau which covers most of the northern and central areas and (3) the tilted block province located along the southern part of Jamaica. Each region has a specific morphological signature which marks a different stage in the Late Miocene to present evolution of the Jamaican restraining bend. The evolution of the bend is mainly associated with the western propagation of major E-trending strike-slip faults and NW-trending thrusts. In the western and central parts of Jamaica the present-day motion between the Caribbean plate and the Gonâve microplate is broadly distributed along several structures, while in the easternmost part of the island this motion seems to be almost completely accommodated along the Blue Mountain range and the Plantain-Garden Fault.

  16. Space station

    NASA Technical Reports Server (NTRS)

    Stewart, Donald F.; Hayes, Judith

    1989-01-01

    The history of American space flight indicates that a space station is the next logical step in the scientific pursuit of greater knowledge of the universe. The Space Station and its complement of space vehicles, developed by NASA, will add new dimensions to an already extensive space program in the United States. The Space Station offers extraordinary benefits for a comparatively modest investment (currently estimated at one-ninth the cost of the Apollo Program). The station will provide a permanent multipurpose facility in orbit necessary for the expansion of space science and technology. It will enable significant advancements in life sciences research, satellite communications, astronomy, and materials processing. Eventually, the station will function in support of the commercialization and industrialization of space. Also, as a prerequisite to manned interplanetary exploration, the long-duration space flights typical of Space Station missions will provide the essential life sciences research to allow progressively longer human staytime in space.

  17. Space Station

    NASA Technical Reports Server (NTRS)

    Anderton, D. A.

    1985-01-01

    The official start of a bold new space program, essential to maintain the United States' leadership in space was signaled by a Presidential directive to move aggressively again into space by proceeding with the development of a space station. Development concepts for a permanently manned space station are discussed. Reasons for establishing an inhabited space station are given. Cost estimates and timetables are also cited.

  18. LOWER CLARK FORK RIVER SYSTEM - RESULTS OF ALGAL ASSAYS PERFORMED ON WATERS COLLECTED AT STATIONS BELOW MILLTOWN DAM TO BELOW NOXON DAM, 1985

    EPA Science Inventory

    A large amount of public concern has been expressed over the general health of the lower Clark Fork River system, Idaho (17010213). The proposed modification of the existing wastewater discharge permit for the Champion International paper mill at Frenchtown has generated much of...

  19. 10. Interior of Pumping Station No. 1 showing details of ...

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

    10. Interior of Pumping Station No. 1 showing details of the gallery, and Greek Revival interior finishes, from the northeast. - Louisville Water Company Pumping Stations, Zorn Avenue & River Road, Louisville, Jefferson County, KY

  20. 4. View of the front of Pumping Station No. 1 ...

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

    4. View of the front of Pumping Station No. 1 showing the two-story central block and the single story wings. - Louisville Water Company Pumping Stations, Zorn Avenue & River Road, Louisville, Jefferson County, KY

  1. 7. STATION 'L' FROM THE WEST BANK OF THE WILLAMETTE ...

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

    7. STATION 'L' FROM THE WEST BANK OF THE WILLAMETTE RIVER LOOKING EAST, SCREEN HOUSES AND TURBINE BUILDINGS IN FOREGROUND - Portland General Electric Company, Station "L", 1841 Southeast Water Street, Portland, Multnomah County, OR

  2. 5. VIEW OF STATION 'L' FROM WEST BANK OF THE ...

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

    5. VIEW OF STATION 'L' FROM WEST BANK OF THE WILLAMETTE RIVER, SCREEN HOUSES AND TURBINE BUILDINGS IN FOREGROUND - Portland General Electric Company, Station "L", 1841 Southeast Water Street, Portland, Multnomah County, OR

  3. Where the Granular Flows Bend

    NASA Astrophysics Data System (ADS)

    Khomenko, E.; Martínez Pillet, V.; Solanki, S. K.; del Toro Iniesta, J. C.; Gandorfer, A.; Bonet, J. A.; Domingo, V.; Schmidt, W.; Barthol, P.; Knölker, M.

    2010-11-01

    Based on IMaX/SUNRISE data, we report on a previously undetected phenomenon in solar granulation. We show that in a very narrow region separating granules and intergranular lanes, the spectral line width of the Fe I 5250.2 Å line becomes extremely small. We offer an explanation of this observation with the help of magneto-convection simulations. These regions with extremely small line widths correspond to the places where the granular flows bend from upflow in granules to downflow in intergranular lanes. We show that the resolution and image stability achieved by IMaX/SUNRISE are important requisites to detect this interesting phenomenon.

  4. 26. INTERIOR VIEW OF OPERATOR'S HOUSE (CENTRAL CONTROL STATION), OLD ...

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

    26. INTERIOR VIEW OF OPERATOR'S HOUSE (CENTRAL CONTROL STATION), OLD LE CLAIRE LOCK, LOOKING WEST - Mississippi River 9-Foot Channel, Lock & Dam No. 14, Upper Mississippi River, Le Claire, Scott County, IA

  5. 49. View of unlined canal near inline stream gaging station, ...

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

    49. View of unlined canal near in-line stream gaging station, looking west. Photo by Robin Lee Tedder, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  6. 50. Stream gaging station in steelpipe well and shelter, looking ...

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

    50. Stream gaging station in steel-pipe well and shelter, looking west. Photo by Robin Lee Tedder, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  7. 1. Photocopied from Photo 1645, Wheelon Station Folder #1, Engineering ...

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

    1. Photocopied from Photo 1645, Wheelon Station Folder #1, Engineering Department, Utah Power & Light Co., Salt Lake City, Utah. UTAH SUGAR CO.'S DAM -- BEAR RIVER CANYON. - Irrigation Diversion Canal, Bear River, Fielding, Box Elder County, UT

  8. 14. PROJECT PLAN, INTAKE PIER, RAW WATER CONDUITS, PUMPING STATION ...

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

    14. PROJECT PLAN, INTAKE PIER, RAW WATER CONDUITS, PUMPING STATION FORCE MAINS, TREATED WATER PIPELINES, AND FILTRATION PLANT, SHEET 1 OF 117, 1920. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  9. Sensitivity analysis of channel-bend hydraulics influenced by vegetation

    NASA Astrophysics Data System (ADS)

    Bywater-Reyes, S.; Manners, R.; McDonald, R.; Wilcox, A. C.

    2015-12-01

    Alternating bars influence hydraulics by changing the force balance of channels as part of a morphodynamic feedback loop that dictates channel geometry. Pioneer woody riparian trees recruit on river bars and may steer flow, alter cross-stream and downstream force balances, and ultimately change channel morphology. Quantifying the influence of vegetation on stream hydraulics is difficult, and researchers increasingly rely on two-dimensional hydraulic models. In many cases, channel characteristics (channel drag and lateral eddy viscosity) and vegetation characteristics (density, frontal area, and drag coefficient) are uncertain. This study uses a beta version of FaSTMECH that models vegetation explicitly as a drag force to test the sensitivity of channel-bend hydraulics to riparian vegetation. We use a simplified, scale model of a meandering river with bars and conduct a global sensitivity analysis that ranks the influence of specified channel characteristics (channel drag and lateral eddy viscosity) against vegetation characteristics (density, frontal area, and drag coefficient) on cross-stream hydraulics. The primary influence on cross-stream velocity and shear stress is channel drag (i.e., bed roughness), followed by the near-equal influence of all vegetation parameters and lateral eddy viscosity. To test the implication of the sensitivity indices on bend hydraulics, we hold calibrated channel characteristics constant for a wandering gravel-bed river with bars (Bitterroot River, MT), and vary vegetation parameters on a bar. For a dense vegetation scenario, we find flow to be steered away from the bar, and velocity and shear stress to be reduced within the thalweg. This provides insight into how the morphodynamic evolution of vegetated bars differs from unvegetated bars.

  10. Peeling, sliding, pulling and bending

    NASA Astrophysics Data System (ADS)

    Lister, John; Peng, Gunnar

    2015-11-01

    The peeling of an elastic sheet away from thin layer of viscous fluid is a simply-stated and generic problem, that involves complex interactions between the flow and elastic deformation on a range of length scales. Consider an analogue of capillary spreading, where a blister of injected viscous fluid spreads due to tension in the overlying elastic sheet. Here the tension is coupled to the deformation of the sheet, and thus varies in time and space. A key question is whether or not viscous shear stresses ahead of the blister are sufficient to prevent the sheet sliding inwards and relieving the tension. Our asymptotic analysis reveals a dichotomy between fast and slow spreading, and between two-dimensional and axisymmetric spreading. In combination with bending stresses and gravity, which may dominate parts of the flow but not others, there is a plethora of dynamical regimes.

  11. 4. ENVIRONMENT, FROM NORTH, SHOWING RIVER ROAD BRIDGE CARRYING CASSELMAN ...

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

    4. ENVIRONMENT, FROM NORTH, SHOWING RIVER ROAD BRIDGE CARRYING CASSELMAN RIVER ROAD OVER CASSELMAN RIVER, WITH MARYLAND GEOLOGICAL SURVEY STREAM-GAUGING STATION AT NORTHEAST CORNER OF BRIDGE - River Road Bridge, Crossing Casselman River on Casselman River Road, Grantsville, Garrett County, MD

  12. Evaluation of the Malaga Bend salinity alleviation project, Eddy County, New Mexico

    USGS Publications Warehouse

    Kunkler, J.L.

    1980-01-01

    In an effort to reduce the flow of brine springs in the Malaga Bend reach of the Pecos River in southeastern New Mexico, brine was pumped from an aquifer underlying the Malaga Bend reach to a local depression known as Anderson Lake. The attempt to improve the quality of river water with this experiment was not successful because brine leakage from Anderson Lake to the nearby Pecos River through permeable subsurface rocks was greater than the previous natural spring inflow. Brine leakage from Anderson Lake from July 22, 1963, through September 30, 1968, was estimated by evaporation-pan, salt accumulation, and dissolved-constituent methods. The leakage values given by these three methods are in good agreement with each other and indicate that between the dates given, leakage from the lake was about 2 ,300 acre-feet, compared with a brine inflow to the lake of about 3,690 acre-feet. Other data indicate that pumping from the brine aquifer greatly reduced the natural inflow from brine springs to the Malaga Bend reach. The rate of brine leakage from Anderson Lake is probably greater than might be expected from other brine lakes in the area because the cavities in the bottom of the lake apparently are in hydrologic connection with the Pecos River. This connection is shown by a relation between the salinity of the Pecos River and the reservoir stage of Anderson Lake. (USGS)

  13. 8. VIEW LOOKING UPSTREAM FROM THE RIVER ARM OF THE ...

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

    8. VIEW LOOKING UPSTREAM FROM THE RIVER ARM OF THE COFFERDAM NEAR STATION (September 1936) - Mississippi River 9-Foot Channel Project, Lock & Dam No. 13, Upper Mississippi River, Fulton, Whiteside County, IL

  14. 46 CFR 56.80-5 - Bending.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....1 of ASME B31.1 (incorporated by reference; see 46 CFR 56.01-2). This shall not prohibit the use of..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Bending and Forming § 56.80-5 Bending. Pipe may be bent by any hot or cold method and to any radius which will...

  15. Application of Surface Geophysical Methods, With Emphasis on Magnetic Resonance Soundings, to Characterize the Hydrostratigraphy of the Brazos River Alluvium Aquifer, College Station, Texas, July 2006 - A Pilot Study

    USGS Publications Warehouse

    Shah, Sachin D.; Kress, Wade H.; Legchenko, Anatoly

    2007-01-01

    The U.S. Geological Survey, in cooperation with the Texas Water Development Board, used surface geophysical methods at the Texas A&M University Brazos River Hydrologic Field Research Site near College Station, Texas, in a pilot study, to characterize the hydrostratigraphic properties of the Brazos River alluvium aquifer and determine the effectiveness of the methods to aid in generating an improved ground-water availability model. Three non-invasive surface geophysical methods were used to characterize the electrical stratigraphy and hydraulic properties and to interpret the hydrostratigraphy of the Brazos River alluvium aquifer. Two methods, time-domain electromagnetic (TDEM) soundings and two-dimensional direct-current (2D-DC) resistivity imaging, were used to define the lateral and vertical extent of the Ships clay, the alluvium of the Brazos River alluvium aquifer, and the underlying Yegua Formation. Magnetic resonance sounding (MRS), a recently developed geophysical method, was used to derive estimates of the hydrologic properties including percentage water content and hydraulic conductivity. Results from the geophysics study demonstrated the usefulness of combined TDEM, 2D-DC resistivity, and MRS methods to reduce the need for additional boreholes in areas with data gaps and to provide more accurate information for ground-water availability models. Stratigraphically, the principal finding of this study is the relation between electrical resistivity and the depth and thickness of the subsurface hydrostratigraphic units at the site. TDEM data defined a three-layer electrical stratigraphy corresponding to a conductor-resistor-conductor that represents the hydrostratigraphic units - the Ships clay, the alluvium of the Brazos River alluvium aquifer, and the Yegua Formation. Sharp electrical boundaries occur at about 4 to 6 and 20 to 22 meters below land surface based on the TDEM data and define the geometry of the more resistive Brazos River alluvium aquifer

  16. Wire and Cable Cold Bending Test

    NASA Technical Reports Server (NTRS)

    Colozza, Anthony

    2010-01-01

    One of the factors in assessing the applicability of wire or cable on the lunar surface is its flexibility under extreme cold conditions. Existing wire specifications did not address their mechanical behavior under cold, cryogenic temperature conditions. Therefore tests were performed to provide this information. To assess this characteristic 35 different insulated wire and cable pieces were cold soaked in liquid nitrogen. The segments were then subjected to bending and the force was recorded. Any failure of the insulation or jacketing was also documented for each sample tested. The bending force tests were performed at room temperature to provide a comparison to the change in force needed to bend the samples due to the low temperature conditions. The results from the bending tests were plotted and showed how various types of insulated wire and cable responded to bending under cold conditions. These results were then used to estimate the torque needed to unroll the wire under these low temperature conditions.

  17. Bending of light in conformal Weyl gravity

    NASA Astrophysics Data System (ADS)

    Sultana, Joseph; Kazanas, Demosthenes

    2010-06-01

    We reexamine the bending of light issue associated with the metric of the static, spherically symmetric solution of Weyl gravity discovered by Mannheim and Kazanas (1989). To this end we employ the procedure used recently by Rindler and Ishak to obtain the bending angle of light by a centrally concentrated spherically symmetric matter distribution in a Schwarzschild-de Sitter background. In earlier studies the term γr in the metric led to the paradoxical result of a bending angle proportional to the photon impact parameter, when using the usual formalism appropriate to asymptotically flat space-times. However, employing the approach of light bending of Rindler and Ishak we show that the effects of this term are in fact insignificant, with the discrepancy between the two procedures attributed to the definition of the bending angle between the asymptotically flat and nonflat spaces.

  18. Effects of airplane flexibility on wing bending strains in rough air

    NASA Technical Reports Server (NTRS)

    Coleman, Thomas L; Press, Harry; Shufflebarger, C C

    1957-01-01

    Some results on the effects of wing flexibility on wing bending strains as determined from flight tests of a Boeing B-29 and a Boeing B-47A airplane in rough air are presented. Results from an analytical study of the flexibility effects on the B-29 wing strains are compared with the experimental results. Both the experimental and calculated results are presented as frequency-response functions of the bending strains at various spanwise wing stations to gust disturbances. In addition, some indirect evidence of the effect of spanwise variations in turbulence on the response of the B-47A airplane is presented.

  19. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  20. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  1. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  2. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  3. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  4. 49 CFR 195.212 - Bending of pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Bending of pipe. 195.212 Section 195.212... PIPELINE Construction § 195.212 Bending of pipe. (a) Pipe must not have a wrinkle bend. (b) Each field bend must comply with the following: (1) A bend must not impair the serviceability of the pipe. (2)...

  5. Gravitropic bending of fruit bodies

    NASA Astrophysics Data System (ADS)

    Hock, Bertold

    Fruit bodies of basidiomycetes exhibit a unique mechanism of gravitropic bending, related to their specific architecture. The gravisensitive region of the stipe directly below the cap coincides with the bending zone. The hyphae of this region are equipped with the ability to generate positional information and translate it into differential growth. A model is introduced with the fundamental characteristics of agent-based modeling as it is applied in robotics and artificial intelligence. The hyphae are equivalent to autonomous decision-making agents on the basis of a simple set of rules. Repetitive interactions between the agents, i.e. the hyphae, permit the correct adjustment of the fruit body independent from its relative position in space. This model is based on the following structural as well as biochemical data derived from the basidiomycete Flammulina velutipes. A statolith-mediated mechanism in each individual hypha of the gravisensitive region accounts for graviperception. Cell nuclei with a density of 1.22 g cm-3 are considered the most likely candidates for gravity-induced sedimentation (statoliths). The number of nuclei in this zone is increased from 2 to up to 10 individual nuclei within each hyphal compartment. The nuclei are suspended in a web of actin filaments anchored in the plasma membrane. Any shift from the vertical position is converted into a change in the gravitational pull exerted on the plasma membrane. This leads to a functional distinction of the upper and lower flanks of each hypha. Each hypha is equipped with the ability to generate and amplify a positional signal perpendicular to the axis of the gravisensitive zone. This signal coordinates different hyphal extension of the upper and lower flank of the stipe: upper flank hyphae grow slower than lower flank hyphae. Hyphal growth requires continued turgor pressure and depends on the expansion of the vacuolar compartment. This vacuolation is conspicuously increased in lower flank

  6. Bend Properties of Sapphire Fibers at Elevated Temperatures. 1; Bend Survivability

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.; Sayir, Haluk

    1995-01-01

    The effect of temperature on the bend radius that a c-axis-oriented sapphire fiber can withstand was determined for fibers of various diameter. Bend stress rupture tests were performed for times of 1-100 h and temperatures of 300-1700 C. Fibers would survive the bend test undeformed, would fracture or would deform. The bend survival radius was determined to be the radius above which no fibers fractured or deformed for a given time-temperature treatment. It was found that the ability of fibers to withstand curvature decreases substantially with time and increasing temperature and that fibers of smaller diameter (46-83 micron) withstood smaller bend radii than would be expected from just a difference in fiber diameter when compared with the bend results of the fibers of large diameter (144 micron). This was probably due to different flaw populations, causing high temperature bend failure for the tested sapphire fibers of different diameters.

  7. 1. VIEW NORTH OF HAMPDEN STATION AND (AT LEFT) CHICOPEE ...

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

    1. VIEW NORTH OF HAMPDEN STATION AND (AT LEFT) CHICOPEE RIVER MOUTH; CONDENSER WATER INTAKE IS AT CENTER, END OF VIADUCT IS VISIBLE THROUGH TREES AT RIGHT - Turners Falls Power & Electric Company, Hampden Station, East bank of Connecticut River, Chicopee, Hampden County, MA

  8. [Effects of the installation of the Rosal hydroelectric power station, Itabapoana River, States of Espírito Santo and Rio de Janeiro, on anophelinae, planorbidae and phlebotominae].

    PubMed

    Rezende, Helder Ricas; Sessa, Paulo Augusto; Ferreira, Adelson Luiz; dos Santos, Claudiney Biral; Leite, Gustavo Rocha; Falqueto, Aloísio

    2009-01-01

    The construction of dams usually changes the composition of the fauna within their areas of influence. In the area where the Rosal hydroelectric power station has been installed, in the States of Espírito Santo and Rio de Janeiro, changes to the abundance of anophelinae, planorbidae and phlebotominae were evaluated before (1998-2000) and after (2000-2005) the damming. Nine sample collection points were defined, each represented by a home and its outbuildings, shelters for domestic animals and water collection points within a radius of 150m. One hundred and three adult anophelinae were collected before the damming and 313 afterwards; 200 immature anophelinae before and 708 afterwards; 868 planorbidae before and 486 afterwards; and 2,979 phlebotominae before and 912 afterwards. The vector record, consisting of anophelinae, planorbidae and phlebotominae, shows the potential of this area for transmission of malaria, schistosomiasis and American cutaneous leishmaniasis. However, the environmental changes did not increase the risk of the occurrence of these diseases. PMID:19448934

  9. Observation Station

    ERIC Educational Resources Information Center

    Rutherford, Heather

    2011-01-01

    This article describes how a teacher integrates science observations into the writing center. At the observation station, students explore new items with a science theme and use their notes and questions for class writings every day. Students are exposed to a variety of different topics and motivated to write in different styles all while…

  10. Averaged indicators of secondary flow in repeated acoustic Doppler current profiler crossings of bends

    USGS Publications Warehouse

    Dinehart, R.L.; Burau, J.R.

    2005-01-01

    [1] Cross-stream velocity was measured in a large river bend at high spatial resolution over three separate survey episodes. A suite of methods for resolving cross-stream velocity distributions was tested on data collected using acoustic Doppler current profilers (ADCP) in the sand-bedded Sacramento River, California. The bend was surveyed with repeated ADCP crossings at eight cross sections during a rising limb of high discharge in February 2004 and twice on recession in March 2004. By translating and interpolating repeated ADCP crossings to planar grids, velocity ensembles at similar positions along irregular boat paths could be averaged. The averaging minimized turbulent fluctuations in streamwise velocities over 1 m/s, enabling the resolution of weaker cross-stream velocities (???15-30 cm/s). Secondary-flow influence on suspended sediment was inferred from a lateral region of acoustic backscatter intensity aligned with outward flow over the point bar. A near-bed decrease in backscatter intensity across the pool corresponded with inward cross-stream flow. These suspension indicators were used to orient averaged velocity grids for unambiguously defining the cross-stream velocity magnitudes. Additional field investigations could test whether the correlation between cross-stream velocity and backscatter intensity patterns results from helical recirculation of suspended sediment to the inside of the bend. These river measurements, consistent with classic and recent laboratory studies, show that ADCP surveys can provide refined views of secondary flow and sediment movement in large rivers.

  11. Analysis and detection of functional outliers in water quality parameters from different automated monitoring stations in the Nalón river basin (Northern Spain).

    PubMed

    Piñeiro Di Blasi, J I; Martínez Torres, J; García Nieto, P J; Alonso Fernández, J R; Díaz Muñiz, C; Taboada, J

    2015-01-01

    The purposes and intent of the authorities in establishing water quality standards are to provide enhancement of water quality and prevention of pollution to protect the public health or welfare in accordance with the public interest for drinking water supplies, conservation of fish, wildlife and other beneficial aquatic life, and agricultural, industrial, recreational, and other reasonable and necessary uses as well as to maintain and improve the biological integrity of the waters. In this way, water quality controls involve a large number of variables and observations, often subject to some outliers. An outlier is an observation that is numerically distant from the rest of the data or that appears to deviate markedly from other members of the sample in which it occurs. An interesting analysis is to find those observations that produce measurements that are different from the pattern established in the sample. Therefore, identification of atypical observations is an important concern in water quality monitoring and a difficult task because of the multivariate nature of water quality data. Our study provides a new method for detecting outliers in water quality monitoring parameters, using turbidity, conductivity and ammonium ion as indicator variables. Until now, methods were based on considering the different parameters as a vector whose components were their concentration values. This innovative approach lies in considering water quality monitoring over time as continuous curves instead of discrete points, that is to say, the dataset of the problem are considered as a time-dependent function and not as a set of discrete values in different time instants. This new methodology, which is based on the concept of functional depth, was applied to the detection of outliers in water quality monitoring samples in the Nalón river basin with success. Results of this study were discussed here in terms of origin, causes, etc. Finally, the conclusions as well as advantages of

  12. Initial Ares I Bending Filter Design

    NASA Technical Reports Server (NTRS)

    Jang, Jiann-Woei; Bedrossian, Nazareth; Hall, Robert; Norris, H. Lee; Hall, Charles; Jackson, Mark

    2007-01-01

    The Ares-I launch vehicle represents a challenging flex-body structural environment for control system design. Software filtering of the inertial sensor output will be required to ensure control system stability and adequate performance. This paper presents a design methodology employing numerical optimization to develop the Ares-I bending filters. The filter design methodology was based on a numerical constrained optimization approach to maximize stability margins while meeting performance requirements. The resulting bending filter designs achieved stability by adding lag to the first structural frequency and hence phase stabilizing the first Ares-I flex mode. To minimize rigid body performance impacts, a priority was placed via constraints in the optimization algorithm to minimize bandwidth decrease with the addition of the bending filters. The bending filters provided here have been demonstrated to provide a stable first stage control system in both the frequency domain and the MSFC MAVERIC time domain simulation.

  13. Thermal static bending of deployable interlocked booms

    NASA Technical Reports Server (NTRS)

    Staugaitis, C. L.; Predmore, R. E.

    1973-01-01

    Metal ribbons processed with a heat-forming treatment are enabled to form tubelike structures when deployed from a roll. Deployable booms of this have been utilized for gravity-gradient stabilization on the RAE, ATS, and Nimbus D satellites. An experimental thermal-mechanics test apparatus was developed to measure the thermal static bending and twist of booms up to 3 meters long. The apparatus was calibrated by using the correlation between calculated and observed thermal bending of a seamless tube. Thermal static bending values of 16 interlocked deployable booms were observed to be within a factor of 2.5 of the values calculated from seamless-tube theory. Out-of-Sun-plane thermal bending was caused by complex heat transfer across the interlocked seam. Significant thermal static twisting was not observed.

  14. Turbulent flow analysis on bend and downstream of the bend for different curvature ratio

    NASA Astrophysics Data System (ADS)

    Chowdhury, Rana Roy; Biswas, Suranjan; Alam, Md. Mahbubul; Islam, A. K. M. Sadrul

    2016-07-01

    A CFD analysis on the bend and downstream of the bend has been carried out for turbulent flow through 90 degree bend pipe with different curvature ratios using standard k-epsilon turbulence model. Numerical results are compared with the existing experimental results, and then a detailed study has been performed to investigate the flow characteristics. For different curvature ratios, the static pressure distributions along inner, outer wall and pressure loss factor with different Reynolds number is analyzed. The obtained results show that pressure distribution and pressure loss factor are dependent for different Reynolds number and curvature ratio throughout the bend. Again, It is observed that the disturbance of the flow due to bend exists for a downstream distance of 50D from the central plane of the bend.

  15. Bending rigidity of composite resin coating clasps.

    PubMed

    Ikebe, K; Kibi, M; Ono, T; Nokubi, T

    1993-12-01

    The purpose of this study is to examine the bending profiles of composite resin coating cast clasps. The cobalt-chromium alloy cast clasps were made using tapered wax pattern. Silane coupling method (Silicoater MD, Kulzer Co.) was used to attach composite resin to metal surface. The breakage and the bending rigidity of composite resin coating clasps were evaluated. Results were as follows: 1) After the repeated bending test to the tips of clasp arm at 10,000 times in 0.25 mm deflection, neither crack on composite resin surface nor separation at resin/metal interface was observed in any specimen. 2) There was no significant difference in the bending rigidity of clasp arms between before and after composite resin coating. From these results, it was demonstrated that the composite resin coating cast clasp was available in clinical cases and coating with composite resin had little influence on the bending rigidity of clasp arms. Therefore, it was suggested that our clasp designing and fabricating system to control the bending rigidity of clasp arms could be applied to composite resin coating clasps. PMID:8935086

  16. A transparent bending-insensitive pressure sensor

    NASA Astrophysics Data System (ADS)

    Lee, Sungwon; Reuveny, Amir; Reeder, Jonathan; Lee, Sunghoon; Jin, Hanbit; Liu, Qihan; Yokota, Tomoyuki; Sekitani, Tsuyoshi; Isoyama, Takashi; Abe, Yusuke; Suo, Zhigang; Someya, Takao

    2016-05-01

    Measuring small normal pressures is essential to accurately evaluate external stimuli in curvilinear and dynamic surfaces such as natural tissues. Usually, sensitive and spatially accurate pressure sensors are achieved through conformal contact with the surface; however, this also makes them sensitive to mechanical deformation (bending). Indeed, when a soft object is pressed by another soft object, the normal pressure cannot be measured independently from the mechanical stress. Here, we show a pressure sensor that measures only the normal pressure, even under extreme bending conditions. To reduce the bending sensitivity, we use composite nanofibres of carbon nanotubes and graphene. Our simulations show that these fibres change their relative alignment to accommodate bending deformation, thus reducing the strain in individual fibres. Pressure sensitivity is maintained down to a bending radius of 80 μm. To test the suitability of our sensor for soft robotics and medical applications, we fabricated an integrated sensor matrix that is only 2 μm thick. We show real-time (response time of ∼20 ms), large-area, normal pressure monitoring under different, complex bending conditions.

  17. A transparent bending-insensitive pressure sensor.

    PubMed

    Lee, Sungwon; Reuveny, Amir; Reeder, Jonathan; Lee, Sunghoon; Jin, Hanbit; Liu, Qihan; Yokota, Tomoyuki; Sekitani, Tsuyoshi; Isoyama, Takashi; Abe, Yusuke; Suo, Zhigang; Someya, Takao

    2016-05-01

    Measuring small normal pressures is essential to accurately evaluate external stimuli in curvilinear and dynamic surfaces such as natural tissues. Usually, sensitive and spatially accurate pressure sensors are achieved through conformal contact with the surface; however, this also makes them sensitive to mechanical deformation (bending). Indeed, when a soft object is pressed by another soft object, the normal pressure cannot be measured independently from the mechanical stress. Here, we show a pressure sensor that measures only the normal pressure, even under extreme bending conditions. To reduce the bending sensitivity, we use composite nanofibres of carbon nanotubes and graphene. Our simulations show that these fibres change their relative alignment to accommodate bending deformation, thus reducing the strain in individual fibres. Pressure sensitivity is maintained down to a bending radius of 80 μm. To test the suitability of our sensor for soft robotics and medical applications, we fabricated an integrated sensor matrix that is only 2 μm thick. We show real-time (response time of ∼20 ms), large-area, normal pressure monitoring under different, complex bending conditions. PMID:26809055

  18. Aerosol size distribution and new particle formation in the western Yangtze River Delta of China: 2 years of measurements at the SORPES station

    NASA Astrophysics Data System (ADS)

    Qi, X. M.; Ding, A. J.; Nie, W.; Petäjä, T.; Kerminen, V.-M.; Herrmann, E.; Xie, Y. N.; Zheng, L. F.; Manninen, H.; Aalto, P.; Sun, J. N.; Xu, Z. N.; Chi, X. G.; Huang, X.; Boy, M.; Virkkula, A.; Yang, X.-Q.; Fu, C. B.; Kulmala, M.

    2015-11-01

    Aerosol particles play important roles in regional air quality and global climate change. In this study, we analyzed 2 years (2011-2013) of measurements of submicron particles (6-800 nm) at a suburban site in the western Yangtze River Delta (YRD) of eastern China. The number concentrations (NCs) of particles in the nucleation, Aitken and accumulation modes were 5300 ± 5500, 8000 ± 4400, 5800 ± 3200 cm-3, respectively. The NCs of total particles are comparable to those at urban/suburban sites in other Chinese megacities, such as Beijing, but about 10 times higher than in the remote western China. Long-range and regional transport largely influenced number concentrations and size distributions of submicron particles. The highest and lowest accumulation-mode particle number concentrations were observed in air masses from the YRD and coastal regions, respectively. Continental air masses from inland brought the highest concentrations of nucleation-mode particles. New particle formation (NPF) events, apparent in 44 % of the effective measurement days, occurred frequently in all the seasons except winter. The frequency of NPF in spring, summer and autumn is much higher than other measurement sites in China. Sulfuric acid was found to be the main driver of NPF events. The particle formation rate was the highest in spring (3.6 ± 2.4 cm-3 s-1), whereas the particle growth rate had the highest values in summer (12.8 ± 4.4 nm h-1). The formation rate was typically high in relatively clean air masses, whereas the growth rate tended to be high in the polluted YRD air masses. The frequency of NPF events and the particle growth rates showed a strong year-to-year difference. In the summer of 2013, associated with a multi-week heat wave and strong photochemical processes, NPF events occurred with larger frequency and higher growth rates compared with the same period in 2012. The difference in the location and strength of the subtropical high pressure system, which influences

  19. Aerosol size distribution and new particle formation in western Yangtze River Delta of China: two-year measurement at the SORPES station

    NASA Astrophysics Data System (ADS)

    Qi, X. M.; Ding, A. J.; Nie, W.; Petäjä, T.; Kerminen, V.-M.; Herrmann, E.; Xie, Y. N.; Zheng, L. F.; Manninen, H.; Aalto, P.; Sun, J. N.; Xu, Z. N.; Chi, X. G.; Huang, X.; Boy, M.; Virkkula, A.; Yang, X.-Q.; Fu, C. B.; Kulmala, M.

    2015-04-01

    Aerosol particles play important roles in regional air quality and global climate change. In this study, we analyzed two-year (2011-2013) of measurements of submicron particles (6-800 nm) at a suburban site in western Yangtze River delta (YRD) of East China. The number concentrations (NCs) of particles in the nucleation, Aitken and accumulation modes were 5300 ± 5500, 8000 ± 4400, 5800 ± 3200 cm-3, respectively. Number concentrations and size distributions of submicron particles were also influenced by long-range and regional transport of air masses. The highest and lowest accumulation mode particle number concentrations were observed in air masses from YRD and coastal region, respectively. Continental air masses from inland had the highest concentrations of nucleation mode particles. New particle formation (NPF) events, apparent in 44% of the effective measurement days, occurred frequently in all the seasons except winter. Radiation and pre-existing particles were found to be the main factors influencing the occurrence of NPF events. The particle formation rate was the highest in spring (3.6 ± 2.4 cm-3 s-1), whereas the particle growth rate had the highest values in summer (12.8 ± 4.4 nm h-1). The formation rate was typically high in relatively clean air masses, whereas the growth rate tended to be high in the polluted YRD air masses. The frequency of NPF events and the growth rate showed a strong year-to-year difference. In the summer of 2013, associated with a multi-week heat wave and photochemical pollution, NPF events occurred more frequently and the growth rate was much higher than in the same period of 2012. The difference in the location and strength of sub-tropical High, which influences the air mass transport pathways and solar radiation, seems to be the driving cause for year-to-year differences. This study reported the longest continuous measurement records of submicron particles in the East China and gained a comprehensive understanding of the

  20. Radio occultation bending angle anomalies during tropical cyclones

    NASA Astrophysics Data System (ADS)

    Biondi, R.; Neubert, T.; Syndergaard, S.; Nielsen, J.

    2011-02-01

    The tropical deep convection affects the radiation balance of the atmosphere changing the water vapor mixing ratio and the temperature of the upper troposphere lower stratosphere. The aim of this work is to better understand these processes and to investigate if severe storms leave a significant signature in radio occultation profiles in the tropical tropopause layer. Using tropical cyclone best track database and data from different GPS radio occultation missions (COSMIC, GRACE, CHAMP, SACC and GPSMET), we selected 1194 profiles in a time window of 3 h and a space window of 300 km from the eye of the cyclone. We show that the bending angle anomaly of a GPS radio occultation signal is typically larger than the climatology in the upper troposphere and lower stratosphere and that a double tropopause during deep convection can easily be detected using this technique. Comparisons with co-located radiosondes, climatology of tropopause altitudes and GOES analyses are also shown to support the hypothesis that the bending angle anomaly can be used as an indicator of convective towers. The results are discussed in connection to the GPS radio occultation receiver which will be part of the Atomic Clock Ensemble in Space (ACES) payload on the International Space Station.

  1. Radio occultation bending angle anomalies during tropical cyclones

    NASA Astrophysics Data System (ADS)

    Biondi, R.; Neubert, T.; Syndergaard, S.; Nielsen, J. K.

    2011-06-01

    The tropical deep convection affects the radiation balance of the atmosphere changing the water vapor mixing ratio and the temperature of the upper troposphere lower stratosphere. The aim of this work is to better understand these processes and to investigate if severe storms leave a significant signature in radio occultation profiles in the tropical tropopause layer. Using tropical cyclone best track database and data from different GPS radio occultation missions (COSMIC, GRACE, CHAMP, SACC and GPSMET), we selected 1194 profiles in a time window of 3 h and a space window of 300 km from the eye of the cyclone. We show that the bending angle anomaly of a GPS radio occultation signal is typically larger than the climatology in the upper troposphere and lower stratosphere and that a double tropopause during deep convection can easily be detected using this technique. Comparisons with co-located radiosondes, climatology of tropopause altitudes and GOES analyses are also shown to support the hypothesis that the bending angle anomaly can be used as an indicator of convective towers. The results are discussed in connection to the GPS radio occultation receiver which will be part of the Atomic Clock Ensemble in Space (ACES) payload on the International Space Station.

  2. Estimation of blade airloads from rotor blade bending moments

    NASA Technical Reports Server (NTRS)

    Bousman, William G.

    1987-01-01

    This paper presents a method for the estimation of blade airloads, based on the measurements of flap bending moments. In this procedure, the blade rotation in vacuum modes is calculated, and the airloads are expressed as an algebraic sum of the mode shapes, modal amplitudes, mass distribution, and frequency properties. The method was validated by comparing the calculated airload distribution with the original wind tunnel measurements which were made using ten modes and twenty measurement stations. Good agreement between the predicted and the measured airloads was found up to 0.90 R, but the agreement degraded towards the blade tip. The method is shown to be quite robust to the type of experimental problems that could be expected to occur in the testing of full-scale and model-scale rotors.

  3. Form of developing bends in reactivated sperm flagella.

    PubMed

    Goldstein, S F

    1976-02-01

    1. Dark-field, multiple-exposure photographs of reactivated tritonated sea urchin sperm flagella swimming under a variety of conditions were analysed. 2. The length, radius and subtended angle of bends increased during bend development. The pattern of development was essentially the same under all conditions observed. 3. The angles of the two bends nearest the base tend to increase at the same rate, cancelling one another, so that the development of new bends causes little if any net microtubular sliding. 4. The direction of microtubular sliding within a bend is initially in the same direction as that within the preceding bend, and reverses as the bend develops. PMID:1270988

  4. A Novel Circular TE01-Mode Bend

    SciTech Connect

    Tantawi, S

    2004-04-19

    Future Linear Colliders and Accelerators require rf systems and components that are capable of handling hundreds of megawatts power levels at x-band frequencies and higher. Standard rf components that have been in use for a long time such as waveguide bends, directional couplers and hybrids, can not be used because of peak field considerations. Indeed, one has to reinvent most of these components taking into account the constraints imposed by ultra-high-power operation. Here, we present a new design for circular waveguides bends propagating the low-loss TE{sub 01} mode. The bend has smooth walls and low field levels. We present a simple synthesis process for designing such device. The general philosophy of this technique can be applied to other components as well. We describe the detailed design of the bend and compare our design with finite element simulations and experimental data. The bend has very low ohmic losses, and the TE{sub 01} mode is transmitted with virtually perfect mode purity.

  5. Sharp bends of phononic crystal surface modes

    NASA Astrophysics Data System (ADS)

    Cicek, Ahmet; Salman, Aysevil; Adem Kaya, Olgun; Ulug, Bulent

    2015-12-01

    Sharp bending of surface waves at the interface of a two-dimensional phononic crystal (PnC) of steel cylinders in air and the method of using a diagonally offset cylindrical scatterer are numerically demonstrated by finite-element method simulations. The radii of the diagonally offset scatterer and the cylinder at the PnC corner, along with the distance between them, are treated as optimization parameters in the genetic algorithm optimization of sharp bends. Surface wave transmittance of at most 5% for the unmodified sharp bend is significantly enhanced to approximately 75% as a result of optimization. A series of transmittance peaks whose maxima increase exponentially, as their widths reduce, with increasing frequency is observed for the optimized sharp bend. The transmittance peaks appear at frequencies corresponding to integer plus half-beat periods, depending on the finite surface length. The optimal parameters are such that the cylinder radius at the PnC corner is not significantly modified, whereas a diagonally offset scatterer having a diameter of almost two periods and a shortest distance of about 0.7 periods between them is required for the strongest transmittance peak. Utilization of PnC surface sharp bends as acoustic ring resonators is demonstrated.

  6. Tunable thermoelectric properties in bended graphene nanoribbons

    NASA Astrophysics Data System (ADS)

    Chang-Ning, Pan; Jun, He; Mao-Fa, Fang

    2016-07-01

    The ballistic thermoelectric properties in bended graphene nanoribbons (GNRs) are systematically investigated by using atomistic simulation of electron and phonon transport. We find that the electron resonant tunneling effect occurs in the metallic–semiconducting linked ZZ-GNRs (the bended GNRs with zigzag edge leads). The electron-wave quantum interference effect occurs in the metallic–metallic linked AA-GNRs (the bended GNRs with armchair edge leads). These different physical mechanisms lead to the large Seebeck coefficient S and high electron conductance in bended ZZ-GNRs/AA-GNRs. Combined with the reduced lattice thermal conduction, the significant enhancement of the figure of merit ZT is predicted. Moreover, we find that the ZTmax (the maximum peak of ZT) is sensitive to the structural parameters. It can be conveniently tuned by changing the interbend length of bended GNRs. The magnitude of ZT ranges from the 0.15 to 0.72. Geometry-controlled ballistic thermoelectric effect offers an effective way to design thermoelectric devices such as thermocouples based on graphene. Project supported by the National Natural Science Foundation of China (Grant No. 61401153) and the Natural Science Foundation of Hunan Province, China (Grant Nos. 2015JJ2050 and 14JJ3126).

  7. 27. Photocopy of scale drawing (from Station 'L' office files, ...

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

    27. Photocopy of scale drawing (from Station 'L' office files, Portland, Oregon) Portland General Electric proposal to city/state, 10/15/1929 FOUNDATION AND LOCATION OF THE STATION SCREEN HOUSE AND A LOOK AT THE TYPICAL DREDGING OF THE RIVER BED WHICH TOOK PLACE ON A PERIODIC BASIS AT STATION 'L' - Portland General Electric Company, Station "L", 1841 Southeast Water Street, Portland, Multnomah County, OR

  8. Using High-Resolution Field Measurements to Model Dune Kinematics in a Large Elongate Meander Bend.

    NASA Astrophysics Data System (ADS)

    Konsoer, K. M.; Rhoads, B. L.; Best, J.; Frias, C. E.; Abad, J. D.; Langendoen, E. J.

    2014-12-01

    Due to recent advances in hydroacoustic technology, such as the development of multibeam echo sounders, it is now possible to obtain highly accurate and detailed bathymetric data for river channels. These data provide the basis for detailed characterizations of bed form morphology ranging from individual ripples to composite dune fields. Theoretical models suggest that bed forms reach an equilibrium morphology based on hydraulic conditions during steady flow. However, at the scale of individual meander bends, bed form morphology will vary according to the local flow structure as influenced by overall bed morphology and planform curvature. Thus, the coevolution of flow structure, bed form morphology, and sediment transport should vary throughout a meander bend. This paper examines spatial variation in bed form characteristics and rates of bed form migration, and thus bed material transport, within a large, actively migrating, elongate meander loop. During a May 2013 flood event on Maier Bend, Wabash River (IL-IN, USA), repeat multibeam echo sounding surveys were conducted ~4 hours apart, providing estimates of dune celerity and volumetric rates of sediment transport at different locations around the bend. Three-dimensional velocity measurements, obtained using an acoustic Doppler current profiler, provide hydraulic data for evaluating interactions between flow structure and bed form morphology. Results show that bed form morphology is highly variable within the bend, ranging from barchans dunes on the upstream limb, 2D ripples across the point bar, and 3D composite dunes with wavelength of ~20 meters near the bend apex. Rates of dune celerity varied from 0.3 m/hr to 0.7 m/hr and were dependent on bed form geometry and local hydraulic conditions. The high-resolution data on flow and form are used to calibrate a 2D numerical model of sediment transport through the bend. Simulations using the calibrated model are used to evaluate the fluvial processes underlying

  9. Mechanism of bending electrostriction in thermoplastic polyurethane

    NASA Astrophysics Data System (ADS)

    Zhou, Y.; Wong, Y. W.; Shin, F. G.

    2004-07-01

    The mechanism of bending electrostriction in polyurethane films is discussed and elucidated through a numerical calculation. The simulations are carried out on a model in which charge carriers are assumed to be electrons injected from the cathode by the Schottky effect, and the positive charges are immobile. Under a dc field, our simulation results show that the electrons go out of the anode, leaving behind a large quantity of positive charge around the anode. As a result, the electric field near the anode eventually becomes much larger than that near the cathode. The asymmetrical electric field distribution leads to an asymmetrical stress distribution through the electrostriction effect and thus to bending of the polyurethane film under the application of a dc electric field. The results can also explain the gradual change in bending direction after reversing the polarity of the electric field.

  10. PHYSICAL, CHEMICAL AND BIOLOGICAL CONDITIONS OF THE SAGAVANIRKTOK RIVER AND NEARBY CONTROL STREAMS, SHAVIOVIK AND CANNING RIVERS

    EPA Science Inventory

    Biological, physical and chemical data were collected from 28 stations on the Sagavanirktok River and five of its tributaries, the Canning River, Shaviovik River, two tundra lakes and Galbraith Lake. These stations are located on the North Slope of Alaska and in the area impacted...

  11. Robotic Arm Comprising Two Bending Segments

    NASA Technical Reports Server (NTRS)

    Mehling, Joshua S.; Difler, Myron A.; Ambrose, Robert O.; Chu, Mars W.; Valvo, Michael C.

    2010-01-01

    The figure shows several aspects of an experimental robotic manipulator that includes a housing from which protrudes a tendril- or tentacle-like arm 1 cm thick and 1 m long. The arm consists of two collinear segments, each of which can be bent independently of the other, and the two segments can be bent simultaneously in different planes. The arm can be retracted to a minimum length or extended by any desired amount up to its full length. The arm can also be made to rotate about its own longitudinal axis. Some prior experimental robotic manipulators include single-segment bendable arms. Those arms are thicker and shorter than the present one. The present robotic manipulator serves as a prototype of future manipulators that, by virtue of the slenderness and multiple- bending capability of their arms, are expected to have sufficient dexterity for operation within spaces that would otherwise be inaccessible. Such manipulators could be especially well suited as means of minimally invasive inspection during construction and maintenance activities. Each of the two collinear bending arm segments is further subdivided into a series of collinear extension- and compression-type helical springs joined by threaded links. The extension springs occupy the majority of the length of the arm and engage passively in bending. The compression springs are used for actively controlled bending. Bending is effected by means of pairs of antagonistic tendons in the form of spectra gel spun polymer lines that are attached at specific threaded links and run the entire length of the arm inside the spring helix from the attachment links to motor-driven pulleys inside the housing. Two pairs of tendons, mounted in orthogonal planes that intersect along the longitudinal axis, are used to effect bending of each segment. The tendons for actuating the distal bending segment are in planes offset by an angle of 45 from those of the proximal bending segment: This configuration makes it possible to

  12. 43. WEST TO DETAIL OF WHEELED SHEET METAL WORK STATION ...

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

    43. WEST TO DETAIL OF WHEELED SHEET METAL WORK STATION BEARING ON LEFT CIRCA 1900 ROLLS FOR BENDING STEEL WINDMILL BLADES TO PROPER CURVATURE AND ON RIGHT CIRCA 1900 BEADING MACHINE FOR ADDING STIFFENING CREASES TO THE EDGES OF SHEET METAL PARTS SUCH AS BLADES. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  13. Temporal Differences in the Hydrologic Regime of the Lower Platte River, Nebraska, 1895-2006

    USGS Publications Warehouse

    Ginting, Daniel; Zelt, Ronald B.; Linard, Joshua I.

    2008-01-01

    Hydroecological Integrity Assessment Process software developed by the U.S. Geological Survey. A subset of 27 nonredundant indices (of the 171 indices) was selected using principal component analysis. Indices that described monthly streamflow?mean, maximum, minimum, skewness, and coefficients of variation?also were used. Comparison of these selected indices allowed determination of temporal differences among the six 11-water-year periods for each gaging station. The lower Platte River basin was affected by moderate to severe drought conditions in the 1934?44 period. The widespread drought was preceded by mildly to moderately wet conditions in the 1895?1906 period, followed by incipient drought to incipiently wet conditions in the 1951?61 periods and mildly wet conditions in 1966?76 period, moderately wet conditions in the 1985?1995 period, and incipient drought to mildly wet conditions in the 1996?2006 period. Monthly streamflow of the Platte River from Duncan through Louisville, Nebraska, correlated significantly with the monthly Palmer Hydrological Drought Index. Temporal differences in median values of monthly-mean and monthly-maximum streamflow measured at Duncan, North Bend, and Ashland stations between the two moderately wet periods (1895?1905 and 1985?95) indicated that streamflow storage reservoirs and regulation some time after 1906 significantly reduced monthly streamflow magnitude and amplitude?the difference between the highest and lowest median values of monthly mean streamflow. Effects of storage reservoirs on the median values of monthly-minimum streamflow were less obvious. Temporal differences among the other five periods, from 1934 through 2006 when streamflow was affected by storage and regulation, indicated the predominant effects of contrasting climate conditions on median values of monthly mean, maximum, and minimum streamflow. Significant temporal differences in monthly streamflow values were evident mainly between the two periods of greatly

  14. Distributed and Localized Deformation Along the Lebanese Restraining Bend from Geomorphic Observations and Modeling

    NASA Astrophysics Data System (ADS)

    Goren, L.; Castelltort, S.; Klinger, Y.

    2014-12-01

    The Dead Sea Fault System changes its orientation across Lebanon and forms a restraining bend. The oblique deformation along the Lebanese restraining bend is characterized by a complex suite of tectonic structures, among which, the Yammouneh Fault (YF), is believed to be the main strand that relays deformation from the southern section to the northern section of the Dead Sea Fault System. However, uncertainties regarding slip rates and strain partitioning in Lebanon still prevail. Here, we use morphometric analysis together with analytical and numerical models to constrain rates and modes of distributed and localized deformation along the Lebanese restraining bend.The rivers that drain the western flank of Mount Lebanon show a consistent counterclockwise rotation with respect to an expected orogen perpendicular orientation. Moreover, a pattern of divide disequilibrium in between these rivers emerges from an application of the χ mapping technique, which aims at estimating the degree of geometrical and topological disequilibrium in river networks. These geometrical patterns are compatible with simulation results using a landscape evolution model, which imposes a distributed velocity field along a domain that represents the western flank of Mount Lebanon. We further develop an analytical model that relates the river orientation to a set of kinematic parameters that represents a combined pure and simple shear strain field, and we find the parameters that best explain the present orientation of the western Lebanon rivers. Our results indicate that distributed deformation to the west of the YF takes as much as 30% of the relative Arabia-Sinai plate velocity since the late Miocene, and that the average slip rate along the YF during the same time interval has been 3.8-4.4 mm/yr. The theoretical model can further explain the inferred rotation from Paleomagnetic measurements.

  15. The life of a meander bend: Connecting shape and dynamics via analysis of a numerical model

    NASA Astrophysics Data System (ADS)

    Schwenk, Jon; Lanzoni, Stefano; Foufoula-Georgiou, Efi

    2015-04-01

    Analysis of bend-scale meandering river dynamics is a problem of theoretical and practical interest. This work introduces a method for extracting and analyzing the history of individual meander bends from inception until cutoff (called "atoms") by tracking backward through time the set of two cutoff nodes in numerical meander migration models. Application of this method to a simplified yet physically based model provides access to previously unavailable bend-scale meander dynamics over long times and at high temporal resolutions. We find that before cutoffs, the intrinsic model dynamics invariably simulate a prototypical cutoff atom shape we dub simple. Once perturbations from cutoffs occur, two other archetypal cutoff planform shapes emerge called long and round that are distinguished by a stretching along their long and perpendicular axes, respectively. Three measures of meander migration—growth rate, average migration rate, and centroid migration rate—are introduced to capture the dynamic lives of individual bends and reveal that similar cutoff atom geometries share similar dynamic histories. Specifically, through the lens of the three shape types, simples are seen to have the highest growth and average migration rates, followed by rounds, and finally longs. Using the maximum average migration rate as a metric describing an atom's dynamic past, we show a strong connection between it and two metrics of cutoff geometry. This result suggests both that early formative dynamics may be inferred from static cutoff planforms and that there exists a critical period early in a meander bend's life when its dynamic trajectory is most sensitive to cutoff perturbations. An example of how these results could be applied to Mississippi River oxbow lakes with unknown historic dynamics is shown. The results characterize the underlying model and provide a framework for comparisons against more complex models and observed dynamics.

  16. Variation of dissolved organic carbon transported by two Chinese rivers: The Changjiang River and Yellow River.

    PubMed

    Liu, Dong; Pan, Delu; Bai, Yan; He, Xianqiang; Wang, Difeng; Zhang, Lin

    2015-11-15

    Real-time monitoring of riverine dissolved organic carbon (DOC) and the associated controlling factors is essential to coastal ocean management. This study was the first to simulate the monthly DOC concentrations at the Datong Hydrometric Station for the Changjiang River and at the Lijin Hydrometric Station for the Yellow River from 2000 to 2013 using a multilayer back-propagation neural network (MBPNN), along with basin remote-sensing products and river in situ data. The average absolute error between the modeled values and in situ values was 9.98% for the Changjiang River and 10.84% for the Yellow River. As an effect of water dilution, the variations of DOC concentrations in the two rivers were significantly negatively affected by discharge, with lower values reported during the wet season. Moreover, vegetation growth status and agricultural activities, represented by the gross primary product (GPP) and cropland area percent (CropPer) in the river basin, respectively, also significantly affected the DOC concentration in the Changjiang River, but not the Yellow River. The monthly riverine DOC flux was calculated using modeled DOC concentrations. In particular, the riverine DOC fluxes were affected by discharge, with 71.06% being reported for the Changjiang River and 90.71% for the Yellow River. Over the past decade, both DOC concentration and flux in the two rivers have not shown significant changes. PMID:26404069

  17. Interdisciplinary Invitations: Exploring Gee's Bend Quilts

    ERIC Educational Resources Information Center

    Mitchell, Rebecca; Whitin, Phyllis; Whitin, David

    2012-01-01

    Engaging with the quilts of Gee's Bend offers a rich opportunity for students in grades four through eight to develop appreciation for pattern, rhythm, and innovation while learning about history, entrepreneurship, and political activism. By easily accessing print, film, and Internet resources teachers can include these vibrant quilts and…

  18. Aerosol deposition in bends with turbulent flow

    SciTech Connect

    McFarland, A.R.; Gong, H.; Wente, W.B.

    1997-08-01

    The losses of aerosol particles in bends were determined numerically for a broad range of design and operational conditions. Experimental data were used to check the validity of the numerical model, where the latter employs a commercially available computational fluid dynamics code for characterizing the fluid flow field and Lagrangian particle tracking technique for characterizing aerosol losses. Physical experiments have been conducted to examine the effect of curvature ratio and distortion of the cross section of bends. If it curvature ratio ({delta} = R/a) is greater than about 4, it has little effect on deposition, which is in contrast with the recommendation given in ANSI N13.1-1969 for a minimum curvature ratio of 10. Also, experimental results show that if the tube cross section is flattened by 25% or less, the flattening also has little effect on deposition. Results of numerical tests have been used to develop a correlation of aerosol penetration through a bend as a function of Stokes number (Stk), curvature ratio ({delta}) and the bend angle ({theta}). 17 refs., 10 figs., 2 tabs.

  19. Probing the elastic limit of DNA bending

    PubMed Central

    Le, Tung T.; Kim, Harold D.

    2014-01-01

    Sharp bending of double-stranded DNA (dsDNA) plays an essential role in genome structure and function. However, the elastic limit of dsDNA bending remains controversial. Here, we measured the opening rates of small dsDNA loops with contour lengths ranging between 40 and 200 bp using single-molecule Fluorescence Resonance Energy Transfer. The relationship of loop lifetime to loop size revealed a critical transition in bending stress. Above the critical loop size, the loop lifetime changed with loop size in a manner consistent with elastic bending stress, but below it, became less sensitive to loop size, indicative of softened dsDNA. The critical loop size increased from ∼60 bp to ∼100 bp with the addition of 5 mM magnesium. We show that our result is in quantitative agreement with the kinkable worm-like chain model, and furthermore, can reproduce previously reported looping probabilities of dsDNA over the range between 50 and 200 bp. Our findings shed new light on the energetics of sharply bent dsDNA. PMID:25122748

  20. UV - BIG BEND NATIONAL PARK TX

    EPA Science Inventory

    Brewer 130 is located in Big Bend NP, measuring ultraviolet solar radiation. Irradiance and column ozone are derived from this data. Ultraviolet solar radiation is measured with a Brewer Mark IV, single-monochrometer, spectrophotometer manufactured by SCI-TEC Instruments, Inc. of...

  1. The Hungarian-Americans of South Bend.

    ERIC Educational Resources Information Center

    Scherer, Darlene; Rasmussen, Karen, Ed.

    Developed as part of an ethnic heritage studies program, this historical narrative of Hungarian Americans in South Bend, Indiana, is intended to increase cultural awareness and appreciation. The document is divided into three sections. Section I offers a brief history of Hungary and describes the background of the three emigrant groups; lower…

  2. Bending of skew plates of variable rigidity.

    NASA Technical Reports Server (NTRS)

    Willems, N.; Mahmood, S. S.

    1972-01-01

    Description of an analytical procedure for studying the bending of thin skew plates of a thickness varying in one direction, under arbitrary lateral loading. The analysis was programmed for execution on an electronic computer for various conditions and types of loading. The results obtained suggest that the proposed analytical procedure is more accurate than the finite-difference technique used in earlier investigations.

  3. Age of the Hawaiian-Emperor bend

    USGS Publications Warehouse

    Dalrymple, G.B.; Clague, D.A.

    1976-01-01

    40Ar/39Ar age data on alkalic and tholeiitic basalts from Diakakuji and Kinmei Seamounts in the vicinity of the Hawaiian-Emperor bend indicate that these volcanoes are about 41 and 39 m.y. old, respectively. Combined with previously published age data on Yuryaku and Ko??ko Seamounts, the new data indicate that the best age for the bend is 42.0 ?? 1.4 m.y. Petrochemical data indicate that the volcanic rocks recovered from bend seamounts are indistinguishable from Hawaiian volcanic rocks, strengthening the hypothesis that the Hawaiian-Emperor bend is part of the Hawaiian volcanic chain. 40Ar/39Ar total fusion ages on altered whole-rock basalt samples are consistent with feldspar ages and with 40Ar/39Ar incremental heating data and appear to reflect the crystallization ages of the samples even though conventional K-Ar ages are significantly younger. The cause of this effect is not known but it may be due to low-temperature loss of 39Ar from nonretentive montmorillonite clays that have also lost 40Ar. ?? 1976.

  4. 33 CFR 117.171 - Middle River.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Middle River. 117.171 Section 117... OPERATION REGULATIONS Specific Requirements California § 117.171 Middle River. (a) The draw of the San..., mile 9.8 near Middle River Station, shall open on signal if at least 12 hours notice is given to...

  5. 33 CFR 117.171 - Middle River.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Middle River. 117.171 Section 117... OPERATION REGULATIONS Specific Requirements California § 117.171 Middle River. (a) The draw of the San..., mile 9.8 near Middle River Station, shall open on signal if at least 12 hours notice is given to...

  6. 33 CFR 117.171 - Middle River.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Middle River. 117.171 Section 117... OPERATION REGULATIONS Specific Requirements California § 117.171 Middle River. (a) The draw of the San..., mile 9.8 near Middle River Station, shall open on signal if at least 12 hours notice is given to...

  7. 33 CFR 117.171 - Middle River.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Middle River. 117.171 Section 117... OPERATION REGULATIONS Specific Requirements California § 117.171 Middle River. (a) The draw of the San..., mile 9.8 near Middle River Station, shall open on signal if at least 12 hours notice is given to...

  8. 33 CFR 117.171 - Middle River.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Middle River. 117.171 Section 117... OPERATION REGULATIONS Specific Requirements California § 117.171 Middle River. (a) The draw of the San..., mile 9.8 near Middle River Station, shall open on signal if at least 12 hours notice is given to...

  9. Three-Dimensional Gravity-Current Flow Within a Subaqueous Bend: Spatial Evolution and Force Balance Variations

    NASA Astrophysics Data System (ADS)

    Parsons, D. R.; Peakall, J.; Wei, T.; Best, J. L.; Chen, Z.; Zhao, B.

    2012-12-01

    The nature of three-dimensional flow in submarine channel bends is poorly understood, largely due to the absence of detailed data from natural channels. Here data from density-driven flows in a large reservoir on the Yellow River are presented showing the spatio-temporal variation of flow around a subaqueous bend. The data demonstrate for the first time that reversed helical flow, relative to that found in river channel bends, can occur from the centrifugal forcing of flow, even when the Coriolis force acts in the opposite direction. The data also suggest that reversed helical flow fields in submarine channels may be considerably more frequent than currently estimated, notably for bends where Coriolis and centrifugal forces combine. Additionally, our study provides the first field evidence suggesting that sinuous submarine channels can exhibit asymmetry in helical flow orientation between left and right-turning bends, with major implications for the morphodynamics of submarine channels and their resultant patterns of sedimentation and the distribution of depositional units across submarine fans.

  10. Spatio-temporal variation in bed-material load using dune topography collected during a severe flood on the coastal Trinity River, east TX, USA

    NASA Astrophysics Data System (ADS)

    Mason, J.; Mohrig, D. C.

    2015-12-01

    A series of six repeat surveys along 27 kilometers of the coastal Trinity River in east Texas, USA, reveal the temporal and spatial changes in bed material load during and following a historically large flood. The river event was above the National Weather Service flood stage for 55 days at the Liberty USGS station, and had a maximum discharge of about 80,000 cfs. As a community, we are beginning to understand how fluvial geomorphology is influenced by the backwater effect, but we still lack an understanding of how the bed-material transport adjusts to accommodate larger-scale changes in river bend pattern and kinematics. Survey data from this project includes sidescan sonar along the channel centerline, multibeam bathymetry, and channel bed sediment samples. In combination, this data set provides new insight into how and when bed material, primarily medium sand with some pebbles, moves through this region, and how this connects to previously observed changes in channel geometry (including downstream decreases in channel width to depth ratio, bar form volume and surface area, and lateral migration rates of river bends). Preliminary examination of sidescan sonar of two bends within the survey area, one upstream and one downstream, reveal a striking difference in bedform behavior in response to the changing hydrograph. Upstream, bedforms decrease 80% in height and 83% in length and increase in 3-dimensionality throughout the extended peak flow. During the falling limb of the flood these same bedforms increase in size as they become more laterally continuous and straight-crested. Downstream, 3-dimensional bedforms decrease 80% in height and 87% in length throughout the extended peak flow and then remain this size during the falling limb of the flood. This presentation will discuss these results with respect to backwater dynamics, sediment supply and transport, implications for coastal geomorphology as well as sediment delivery into deltaic systems.

  11. 55. INTERIOR VIEW OF CENTRAL CONTROL STATION, WITH A DETAIL ...

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

    55. INTERIOR VIEW OF CENTRAL CONTROL STATION, WITH A DETAIL VIEW OF THE CENTRAL CONTROL PANEL, LOOKING SOUTHWEST - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 10, Guttenberg, Clayton County, IA

  12. 56. INTERIOR VIEW OF CENTRAL CONTROL STATION, WITH A DETAIL ...

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

    56. INTERIOR VIEW OF CENTRAL CONTROL STATION, WITH A DETAIL VIEW OF THE CENTRAL CONTROL PANEL, LOOKING SOUTHWEST - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 10, Guttenberg, Clayton County, IA

  13. 54. INTERIOR VIEW OF CENTRAL CONTROL STATION, FIRST FLOOR, SHOWING ...

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

    54. INTERIOR VIEW OF CENTRAL CONTROL STATION, FIRST FLOOR, SHOWING CENTRAL CONTROL PANEL AND GENERATOR MOTOR, LOOKING SOUTH - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 10, Guttenberg, Clayton County, IA

  14. 5. ROSS POWERHOUSE: SAME CAMERA STATION AS ABOVE PHOTO BUT ...

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

    5. ROSS POWERHOUSE: SAME CAMERA STATION AS ABOVE PHOTO BUT LOOKING EAST. NOTE INFORMATION DISPLAY FOR TOURISTS AT FLOOR LEVEL, 1987. - Skagit Power Development, Ross Powerhouse, On Skagit River, 10.7 miles upstream from Newhalem, Newhalem, Whatcom County, WA

  15. Northern view of inside diameter welding station of the saw ...

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

    Northern view of inside diameter welding station of the saw line in bay9 of the main pipe mill building. - U.S. Steel National Tube Works, Main Pipe Mill Building, Along Monongahela River, McKeesport, Allegheny County, PA

  16. MAIN HYDRAULIC OIL TANK FOR GOVERNORS, AND 56 KW STATION ...

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

    MAIN HYDRAULIC OIL TANK FOR GOVERNORS, AND 56 KW STATION GENERATOR WITH MECHANICAL GOVERNOR. PHOTO BY JET LOWE, HAER, 1995. - Elwha River Hydroelectric System, Glines Hydroelectric Dam & Plant, Port Angeles, Clallam County, WA

  17. ORIGINAL 1912 STATION POWER TRANSFORMERS IN HIGHTENSION ROOM, SW CORNER ...

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

    ORIGINAL 1912 STATION POWER TRANSFORMERS IN HIGH-TENSION ROOM, SW CORNER OF THE POWERHOUSE. PHOTO BY JET LOWE, HAER, 1995. - Elwha River Hydroelectric System, Elwha Hydroelectric Dam & Plant, Port Angeles, Clallam County, WA

  18. 51. INTERIOR VIEW OF CENTRAL CONTROL STATION ON FIRST FLOOR, ...

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

    51. INTERIOR VIEW OF CENTRAL CONTROL STATION ON FIRST FLOOR, SHOWING CENTRAL CONTROL PANEL AND GENERATOR MOTOR, LOOKING SOUTHWEST - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 9, Lynxville, Crawford County, WI

  19. 31. INTERIOR VIEW OF MAIN LOCK, WITH CENTRAL CONTROL STATION ...

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

    31. INTERIOR VIEW OF MAIN LOCK, WITH CENTRAL CONTROL STATION IN RIGHT BACKGROUND, LOOKING NORTHEAST, UPSTREAM - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 9, Lynxville, Crawford County, WI

  20. 58. VIEW SHOWING MASONRY WORK ON CENTRAL CONTROL STATION NEARING ...

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

    58. VIEW SHOWING MASONRY WORK ON CENTRAL CONTROL STATION NEARING COMPLETION Photograph No. 4042. October 12, 1938 - Upper Mississippi River Nine-Foot Channel Project, Lock & Dam No. 25, Cap au Gris, Lincoln County, MO

  1. 19. DETAIL VIEW OF UPPER EAST WALL CONTROL STATION, SHOWING ...

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

    19. DETAIL VIEW OF UPPER EAST WALL CONTROL STATION, SHOWING EMERGENCY BULKHEAD STIFFLEG DERRICK TO RIGHT, LOOKING WEST - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 27, Granite City, Madison County, IL

  2. Integrated Hydrogeological Investigation on the Vulnerability of a Pumping Station at a Losing Stream

    NASA Astrophysics Data System (ADS)

    Ngueleu Kamangou, Stephane; Vogt, Tobias; Cirpka, Olaf

    2010-05-01

    River restoration usually includes alteration of the river channel morphology. Thereby the interaction between river and groundwater can be modified. For the design of a river restoration project - especially in the vicinity of a groundwater pumping well for drinking water production - this impact must be predicted. But a good prediction requires a proper understanding of the existing situation. Numerical models help to improve the strategy of a successful river restoration project. The main objective of this study was to investigate the vulnerability of a pumping station located at losing river in northeast Switzerland. Besides the effect that river restoration could create, a particular attention was placed on the effect of a beaver dam in a side channel close to the pumping station. Analysis of field measurements coupled with numerical modeling of the pumping station area improved the understanding of the interactions in the river corridor between the river, side channels and the alluvial aquifer.

  3. Intelligent Virtual Station (IVS)

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Intelligent Virtual Station (IVS) is enabling the integration of design, training, and operations capabilities into an intelligent virtual station for the International Space Station (ISS). A viewgraph of the IVS Remote Server is presented.

  4. Residual Field Correction of Pulsed Bending Magnet

    NASA Astrophysics Data System (ADS)

    Takano, Junpei; Igarashi, Susumu; Kamikubota, Norihiko; Meigo, Shin-ichiro; Sato, Kenichi; Shirakata, Masashi; Yamada, Shuei

    The Japan Proton Accelerator Research Complex (J-PARC) has an accelerator chain, Linac, Rapid Cycling Synchrotron (RCS), and Main Ring (MR). The RCS accelerates the proton beam up to 3 GeV every 40 msec. After the beam is extracted from the RCS, it is delivered to a beam transport line, which is 3NBT for the Material and Life Science Experimental Facility (MLF). Some bunches of the proton beam are bended from the 3NBT to another beam transport line, which is 3-50BT for the MR, by using a pulsed bending magnet (PB) [1]. However, the beam orbit in the 3NBT is kicked by the residual magnetic field of the PB. In order to correct the residual magnetic field, additional coils had been wound on the PB poles. As a result of scanning the current pattern of the correction coils, the orbit distortion in the 3NBT has been reduced.

  5. Monitoring thermoplastic composites under cyclic bending tests

    NASA Astrophysics Data System (ADS)

    Boccardi, Simone; Meola, Carosena; Carlomagno, Giovanni Maria; Simeoli, Giorgio; Acierno, Domenico; Russo, Pietro

    2016-05-01

    This work is concerned with the use of infrared thermography to visualize temperature variations linked to thermo-elastic effects developing over the surface of a specimen undergoing deflection under bending tests. Several specimens are herein considered, which involve change of matrix and/or reinforcement. More specifically, the matrix is either a pure polypropylene, or a polypropylene added with a certain percentage of compatibilizing agent; the reinforcement is made of glass, or jute. Cyclic bending tests are carried out by the aid of an electromechanical actuator. Each specimen is viewed, during deflection, from one surface by an infrared imaging device. As main finding the different specimens display surface temperature variations which depend on the type of material in terms of both matrix and reinforcement.

  6. Combined bending-torsion fatigue reliability. III

    NASA Technical Reports Server (NTRS)

    Kececioglu, D.; Chester, L. B.; Nolf, C. F., Jr.

    1975-01-01

    Results generated by three, unique fatigue reliability research machines which can apply reversed bending loads combined with steady torque are presented. AISI 4340 steel, grooved specimens with a stress concentration factor of 1.42 and 2.34, and Rockwell C hardness of 35/40 were subjected to various combinations of these loads and cycled to failure. The generated cycles-to-failure and stress-to-failure data are statistically analyzed to develop distributional S-N and Goodman diagrams. Various failure theories are investigated to determine which one represents the data best. The effects of the groove, and of the various combined bending-torsion loads, on the S-N and Goodman diagrams are determined. Two design applications are presented which illustrate the direct useability and value of the distributional failure governing strength and cycles-to-failure data in designing for specified levels of reliability and in predicting the reliability of given designs.

  7. Torsion and transverse bending of cantilever plates

    NASA Technical Reports Server (NTRS)

    Reissner, Eric; Stein, Manuel

    1951-01-01

    The problem of combined bending and torsion of cantilever plates of variable thickness, such as might be considered for solid thin high-speed airplane or missile wings, is considered in this paper. The deflections of the plate are assumed to vary linearly across the chord; minimization of the potential energy by means of the calculus of variations then leads to two ordinary linear differential equations for the bending deflections and the twist of the plate. Because the cantilever is analyzed as a plate rather than as a beam, the effect of constraint against axial warping in torsion is inherently included. The application of this method to specific problems involving static deflection, vibration, and buckling of cantilever plates is presented. In the static-deflection problems, taper and sweep are considered.

  8. Fracture of surface cracks loaded in bending

    SciTech Connect

    Chao, Y.J.; Reuter, W.G.

    1997-12-31

    Theoretical background of the constraint effect in brittle fracture of solids is reviewed. Fracture test data from D6-aC, a high strength steel, using three-point-bend (SE(B)) specimens and surface cracked plate (SC(B)) specimens under bending are presented. It is shown that the SE(B) data has an elevated fracture toughness for increasing a/W, i.e., a crack geometry with a larger T/K corresponds to a higher K{sub c} which is consistent with the theoretical prediction. The fundamental fracture properties, i.e., the critical strain and the critical distance, determined from the SE(B) test data are then applied to the interpretation and prediction of the SC(B) test data. Reasonable agreement is achieved for the crack growth initiation site and the load.

  9. Effect of confinements: Bending in Paramecium

    NASA Astrophysics Data System (ADS)

    Eddins, Aja; Yang, Sung; Spoon, Corrie; Jung, Sunghwan

    2012-02-01

    Paramecium is a unicellular eukaryote which by coordinated beating of cilia, generates metachronal waves which causes it to execute a helical trajectory. We investigate the swimming parameters of the organism in rectangular PDMS channels and try to quantify its behavior. Surprisingly a swimming Paramecium in certain width of channels executes a bend of its flexible body (and changes its direction of swimming) by generating forces using the cilia. Considering a simple model of beam constrained between two walls, we predict the bent shapes of the organism and the forces it exerts on the walls. Finally we try to explain how bending (by sensing) can occur in channels by conducting experiments in thin film of fluid and drawing analogy to swimming behavior observed in different cases.

  10. Development of Bend Sensor for Catheter Tip

    NASA Astrophysics Data System (ADS)

    Nagano, Yoshitaka; Sano, Akihito; Fujimoto, Hideo

    Recently, a minimally invasive surgery which makes the best use of the catheter has been becoming more popular. In endovascular coil embolization for a cerebral aneurysm, the observation of the catheter's painting phenomenon is very important to execute the appropriate manipulation of the delivery wire and the catheter. In this study, the internal bend sensor which consists of at least two bending enhanced plastic optical fibers was developed in order to measure the curvature of the catheter tip. Consequently, the painting could be more sensitively detected in the neighborhood of the aneurysm. In this paper, the basic characteristics of the developed sensor system are described and its usefulness is confirmed from the comparison of the insertion force of delivery wire and the curvature of catheter tip in the experiment of coil embolization.

  11. Molecular Origin of Model Membrane Bending Rigidity

    SciTech Connect

    Kurtisovski, Erol; Taulier, Nicolas; Waks, Marcel; Ober, Raymond; Urbach, Wladimir

    2007-06-22

    The behavior of the bending modulus {kappa} of bilayers in lamellar phases was studied by Small Angle X-ray Scattering technique for various nonionic C{sub i}E{sub j} surfactants. The bilayers are either unswollen and dispersed in water or swollen by water and dispersed in dodecane. For unswollen bilayers, the values of {kappa} decrease with both an increase in the area per surfactant molecule and in the polar head length. They increase when the aliphatic chain length increases at constant area per surfactant molecule. Whereas for water-swollen membranes, the values of {kappa} decrease as the content of water increases converging to the value of the single monolayer bending modulus. Such a behavior results from the decoupling of the fluctuations of the two surfactant membrane monolayers. Our results emphasize the determinant contribution of the surfactant conformation to {kappa}.

  12. Molecular Origin of Model Membrane Bending Rigidity

    NASA Astrophysics Data System (ADS)

    Kurtisovski, Erol; Taulier, Nicolas; Ober, Raymond; Waks, Marcel; Urbach, Wladimir

    2007-06-01

    The behavior of the bending modulus κ of bilayers in lamellar phases was studied by Small Angle X-ray Scattering technique for various nonionic CiEj surfactants. The bilayers are either unswollen and dispersed in water or swollen by water and dispersed in dodecane. For unswollen bilayers, the values of κ decrease with both an increase in the area per surfactant molecule and in the polar head length. They increase when the aliphatic chain length increases at constant area per surfactant molecule. Whereas for water-swollen membranes, the values of κ decrease as the content of water increases converging to the value of the single monolayer bending modulus. Such a behavior results from the decoupling of the fluctuations of the two surfactant membrane monolayers. Our results emphasize the determinant contribution of the surfactant conformation to κ

  13. Index of stations : surface-water data-collection network of Texas, September 1998

    USGS Publications Warehouse

    Gandara, S. C., (compiler); Barbie, Dana L.

    1999-01-01

    As of September 30, 1998, the surface-water data-collection network of Texas (table 1) included 313 continuous-recording streamflow stations (D), 22 gage-height record only stations (G), 23 crest-stage partial-record stations (C), 39 flood-hydrograph partial-record stations (H), 25 low-flow partial-record stations (L), 1 continuous-recording temperature station (M1), 25 continuous-recording temperature and conductivity stations (M2), 3 continuous-recording temperature, conductivity, and dissolved oxygen stations (M3), 13 continuous-recording temperature, conductivity, dissolved oxygen, and pH stations (M4), 5 daily chemical-quality stations (Qd), 133 periodic chemical-quality stations (Qp), 16 reservoir/lake surveys for water quality (Qs), and 70 continuous or daily reservoir-content stations (R). Plate 1 identifies the major river basins in Texas and shows the location of the stations listed in table 1.

  14. Meandering down to the Sea: The Wandering Ways of Rivers.

    ERIC Educational Resources Information Center

    Aslamazov, Lev

    1992-01-01

    Discusses the hydrodynamic reasons why a riverbed meanders through a plain. Describes how water movement at a bend in a river causes erosion and changes in the riverbed. Provides a mathematical model to explain the periodic shape of meanders of a river in a plain. (MDH)

  15. Strain Engineering of Phosphorene via Bending

    NASA Astrophysics Data System (ADS)

    Verma, Deepti; Dumitrica, Traian

    Phosphorene (PE) - the newly discovered 2D derivative of Phosphorus - has an inherent band gap and a high current on/off ratio. Manipulating strain in PE films - strain engineering (SE) - will offer the opportunity to further tailor its electronic properties. Using objective boundary conditions (OBC) coupled with density functional tight binding model (DFTB), we calculate bending rigidity of PE and its 2D allotropes by modeling bent PE as large diameter nanotubes (PNTs). OBCs not only allow for drastic reductions in the number of atoms in simulations but also enable simulations of chiral PNTs, which is impossible with periodic boundary conditions. At the same time, the method describes how bending influences the electronic structure. We establish a robust platform for achieving SE for anisotropic 2D films. Using results from our calculations and orthotropic thin shell model we develop equivalent continuum structure (ECS) for PE and its allotropes upon bending. The developed ECS can be used for performing finite element simulations of PE films on substrates.

  16. Forming and Bending of Metal Foams

    NASA Astrophysics Data System (ADS)

    Nebosky, Paul; Tyszka, Daniel; Niebur, Glen; Schmid, Steven

    2004-06-01

    This study examines the formability of a porous tantalum foam, known as trabecular metal (TM). Used as a bone ingrowth surface on orthopedic implants, TM is desirable due to its combination of high strength, low relative density, and excellent osteoconductive properties. This research aims to develop bend and stretch forming as a cost-effective alternative to net machining and EDM for manufacturing thin parts made of TM. Experimentally, bending about a single axis using a wiping die was studied by observing cracking and measuring springback. It was found that die radius and clearance strongly affect the springback properties of TM, while punch speed, embossings, die radius and clearance all influence cracking. Depending on the various combinations of die radius and clearance, springback factor ranged from .70-.91. To examine the affect of the foam microstructure, bending also was examined numerically using a horizontal hexagonal mesh. As the hexagonal cells were elongated along the sheet length, elastic springback decreased. This can be explained by the earlier onset of plastic hinging occurring at the vertices of the cells. While the numerical results matched the experimental results for the case of zero clearance, differences at higher clearances arose due to an imprecise characterization of the post-yield properties of tantalum. By changing the material properties of the struts, the models can be modified for use with other open-cell metallic foams.

  17. Controlled impact demonstration airframe bending bridges

    NASA Technical Reports Server (NTRS)

    Soltis, S. J.

    1986-01-01

    The calibration of the KRASH and DYCAST models for transport aircraft is discussed. The FAA uses computer analysis techniques to predict the response of controlled impact demonstration (CID) during impact. The moment bridges can provide a direct correlation between the predictive loads or moments that the models will predict and what was experienced during the actual impact. Another goal is to examine structural failure mechanisms and correlate with analytical predictions. The bending bridges did achieve their goals and objectives. The data traces do provide some insight with respect to airframe loads and structural response. They demonstrate quite clearly what's happening to the airframe. A direct quantification of metal airframe loads was measured by the moment bridges. The measured moments can be correlated with the KRASH and DYCAST computer models. The bending bridge data support airframe failure mechanisms analysis and provide residual airframe strength estimation. It did not appear as if any of the bending bridges on the airframe exceeded limit loads. (The observed airframe fracture was due to the fuselage encounter with the tomahawk which tore out the keel beam.) The airframe bridges can be used to estimate the impact conditions and those estimates are correlating with some of the other data measurements. Structural response, frequency and structural damping are readily measured by the moment bridges.

  18. 76 FR 81992 - PPL Bell Bend, LLC; Combined License Application for Bell Bend Nuclear Power Plant; Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-29

    ... COMMISSION PPL Bell Bend, LLC; Combined License Application for Bell Bend Nuclear Power Plant; Exemption 1.0..., Certifications, and Approvals for Nuclear Power Plants.'' This reactor is to be identified as Bell Bend Nuclear... application is based upon the U.S. EPR reference COL (RCOL) application for UniStar's Calvert Cliffs...

  19. COTTAGE FARM COMBINED SEWER DETENTION AND CHLORINATION STATION, CAMBRIDGE, MASSACHUSETTS

    EPA Science Inventory

    The Cottage Farm Detention and Chlorination Station was placed in operation by the Metropolitan District Commission on April 29, 1971. The station, located in Cambridge, Massachusetts, diverts and treats combined sewage flows from the Charles River Valley sewer system (15,600 acr...

  20. 11. Station Accumulator Tanks, view to the northeast. The tanks ...

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

    11. Station Accumulator Tanks, view to the northeast. The tanks are visible along the right side of photograph, opposite a wall of the Unit 1 turbine pit. - Washington Water Power Clark Fork River Cabinet Gorge Hydroelectric Development, Powerhouse, North Bank of Clark Fork River at Cabinet Gorge, Cabinet, Bonner County, ID

  1. Dubuque generation station, Dubuque, Iowa

    SciTech Connect

    Peltier, R.

    2008-10-15

    Alliant Energy's Dubuque generation station is a fine example of why small does not mean insignificant in the power generation industry. This winner of the EUCG best performer award in the small plant category shows that its operating excellence towers over that of many larger and much newer coal-fired power plants. The plant has three operating units with boilers originally designed for Illinois basin coal but now Powder River Basin coal makes up 75% of the coal consumed. The boilers can also burn natural gas. 4 photos.

  2. Design of a 90{degree} overmoded waveguide bend

    SciTech Connect

    Nantista, C.; Kroll, N.M.; Nelson, E.M.

    1993-04-01

    A design for a 90{degree} bend for the TE{sub 01} mode in over-moded circular waveguide is presented. A pair of septa, symmetrically placed perpendicular to the plane of the bend, are adiabatically introduced into the waveguide before the bend and removed after it. Introduction of the curvature excites five propagating modes in the curved section. The finite element field solver YAP is used to calculate the propagation constants of these modes in the bend, and the guide diameter, septum depth, septum thickness, and bend radius are set so that the phase advances of all five modes through the bend are equal modulo 2{pi}. To a good approximation these modes are expected to recombine to form a pure mode at the end of the bend.

  3. Characterization of bending loss in hollow flexible terahertz waveguides.

    PubMed

    Doradla, Pallavi; Joseph, Cecil S; Kumar, Jayant; Giles, Robert H

    2012-08-13

    Attenuation characteristics of hollow, flexible, metal and metal/dielectric coated polycarbonate waveguides were investigated using an optically pumped far infrared (FIR) laser at 215 µm. The bending loss of silver coated polycarbonate waveguides were measured as a function of various bending angles, bending radii, and bore diameters. Minimal propagation losses of 1.77, 0.96 dB/m were achieved by coupling the lowest loss TE11 mode into the silver or gold coated waveguide, and HE11 mode into the silver/polystyrene coated waveguides respectively. The maximal bending loss was found to be less than 1 dB/m for waveguides of 2 to 4.1 mm bore diameters, with a 6.4 cm bend radius, and up to 150° bending angle. The investigation shows the preservation of single laser mode in smaller bore waveguides even at greater bending angles. PMID:23038558

  4. Structural geology of the Big Bend anticline, Brooks Range Foothills, Alaska

    NASA Astrophysics Data System (ADS)

    Sanders, Cheryl M.

    Big Bend anticline is near the northern edge of the Brooks Range foothills of northern Alaska. The structure of the foothills is a low-taper triangle zone or passive-roof duplex within Brooks Range foreland basin deposits. The dominant structures are detachment folds locally cut by thrust faults and Big Bend anticline is one of these. This research combines detailed surface mapping (1:25,000) with interpretation of aerial photos and satellite imagery of the Big Bend anticline and seismic reflection data from the Umiat anticline to reconstruct its surface and subsurface geometry. The research area surrounds the Big Bend of the Chandler River and covers approximately 10 km2. The mechanical stratigraphy of the area consists of the competent Nanushuk sandstones between two incompetent units-the overlying Seabee and underlying Torok shales. The structure of the area consists of an east-trending anticline with a hinge that branches westward into two open, broad anticlines and an intervening syncline. A forethrust near the southern hinge and a backthrust near the northern hinge have broken through the anticline west of the branch point. Subsurface data of Umiat anticline combined with surface projected cross sections from the study area provide an analog of the subsurface structure in the Big Bend area. These cross sections show gentle anticlines separated by flat bottomed synclines in competent Nanushuk Formation sandstone. The anticlines overly Torok Formation thickened by north vergent folds and thrust faults above a detachment zone. Collectively, these structures form a low-taper triangle zone. Cross section restoration suggests more shortening in the Torok duplex than in the overlying folds and breakthrough faults. Results of this research provide an analog for other anticlines in the region that are currently the focus of oil and gas exploration.

  5. Evolving efficiency of restraining bends within wet kaolin analog experiments

    NASA Astrophysics Data System (ADS)

    Hatem, Alexandra E.; Cooke, Michele L.; Madden, Elizabeth H.

    2015-03-01

    Restraining bends along strike-slip fault systems evolve by both propagation of new faults and abandonment of fault segments. Scaled analog modeling using wet kaolin allows for qualitative and quantitative observations of this evolution. To explore how bend geometry affects evolution, we model bends with a variety of initial angles, θ, from θ = 0° for a straight fault to θ = 30°. High-angle restraining bends (θ ≥ 20°) overcome initial inefficiencies by abandoning unfavorably oriented restraining segments and propagating multiple new, inwardly dipping, oblique-slip faults that are well oriented to accommodate convergence within the bend. Restraining bends with 0° < θ ≤ 15° maintain activity along the restraining bend segment and grow a single new oblique slip fault on one side of the bend. In all restraining bends, the first new fault propagates at ~5 mm of accumulated convergence. Particle Image Velocimetry analysis provides a complete velocity field throughout the experiments. From these data, we quantify the strike-slip efficiency of the system as the percentage of applied plate-parallel velocity accommodated as slip in the direction of plate motion along faults within the restraining bend. Bends with small θ initially have higher strike-slip efficiency compared to bends with large θ. Although they have different fault geometries, all systems with a 5 cm bend width reach a steady strike-slip efficiency of 80% after 50 mm of applied plate displacement. These experimental restraining bends resemble crustal faults in their asymmetric fault growth, asymmetric topographic gradient, and strike-slip efficiency.

  6. Cricket antennae shorten when bending (Acheta domesticus L.)

    PubMed Central

    Loudon, Catherine; Bustamante, Jorge; Kellogg, Derek W.

    2014-01-01

    Insect antennae are important mechanosensory and chemosensory organs. Insect appendages, such as antennae, are encased in a cuticular exoskeleton and are thought to bend only between segments or subsegments where the cuticle is thinner, more flexible, or bent into a fold. There is a growing appreciation of the dominating influence of folds in the mechanical behavior of a structure, and the bending of cricket antennae was considered in this context. Antennae will bend or deflect in response to forces, and the resulting bending behavior will affect the sensory input of the antennae. In some cricket antennae, such as in those of Acheta domesticus, there are a large number (>100) of subsegments (flagellomeres) that vary in their length. We evaluated whether these antennae bend only at the joints between flagellomeres, which has always been assumed but not tested. In addition we questioned whether an antenna undergoes a length change as it bends, which would result from some patterns of joint deformation. Measurements using light microscopy and SEM were conducted on both male and female adult crickets (Acheta domesticus) with bending in four different directions: dorsal, ventral, medial, and lateral. Bending occurred only at the joints between flagellomeres, and antennae shortened a comparable amount during bending, regardless of sex or bending direction. The cuticular folds separating antennal flagellomeres are not very deep, and therefore as an antenna bends, the convex side (in tension) does not have a lot of slack cuticle to “unfold” and does not lengthen during bending. Simultaneously on the other side of the antenna, on the concave side in compression, there is an increasing overlap in the folded cuticle of the joints during bending. Antennal shortening during bending would prevent stretching of antennal nerves and may promote hemolymph exchange between the antenna and head. PMID:25018734

  7. Deregulation and Station Trafficking.

    ERIC Educational Resources Information Center

    Bates, Benjamin J.

    To test whether the revocation of the Federal Communications Commission's "Anti-Trafficking" rule (requiring television station owners to keep a station for three years before transferring its license to another party) impacted station owner behavior, a study compared the behavior of television station "traffickers" (owners seeking quick turnovers…

  8. Space Station Spartan study

    NASA Technical Reports Server (NTRS)

    Lane, J. H.; Schulman, J. R.; Neupert, W. M.

    1985-01-01

    The required extension, enhancement, and upgrading of the present Spartan concept are described to conduct operations from the space station using the station's unique facilities and operational features. The space station Spartan (3S), the free flyer will be deployed from and returned to the space station and will conduct scientific missions of much longer duration than possible with the current Spartan. The potential benefits of a space station Spartan are enumerated. The objectives of the study are: (1) to develop a credible concept for a space station Spartan; and (2) to determine the associated requirements and interfaces with the space station to help ensure that the 3S can be properly accommodated.

  9. Database for the geologic map of the Bend 30- x 60-minute quadrangle, central Oregon

    USGS Publications Warehouse

    Koch, Richard D.; Ramsey, David W.; Sherrod, David R.; Taylor, Edward M.; Ferns, Mark L.; Scott, William E.; Conrey, Richard M.; Smith, Gary A.

    2010-01-01

    The Bend 30- x 60-minute quadrangle has been the locus of volcanism, faulting, and sedimentation for the past 35 million years. It encompasses parts of the Cascade Range and Blue Mountain geomorphic provinces, stretching from snowclad Quaternary stratovolcanoes on the west to bare rocky hills and sparsely forested juniper plains on the east. The Deschutes River and its large tributaries, the Metolius and Crooked Rivers, drain the area. Topographic relief ranges from 3,157 m (10,358 ft) at the top of South Sister to 590 m (1,940 ft) at the floor of the Deschutes and Crooked Rivers where they exit the area at the north-central edge of the map area. The map encompasses a part of rapidly growing Deschutes County. The city of Bend, which has over 70,000 people living in its urban growth boundary, lies at the south-central edge of the map. Redmond, Sisters, and a few smaller villages lie scattered along the major transportation routes of U.S. Highways 97 and 20. This geologic map depicts the geologic setting as a basis for structural and stratigraphic analysis of the Deschutes basin, a major hydrologic discharge area on the east flank of the Cascade Range. The map also provides a framework for studying potentially active faults of the Sisters fault zone, which trends northwest across the map area from Bend to beyond Sisters. This digital release contains all of the information used to produce the geologic map published as U.S. Geological Survey Geologic Investigations Series I-2683 (Sherrod and others, 2004). The main component of this digital release is a geologic map database prepared using ArcInfo GIS. This release also contains files to view or print the geologic map and accompanying descriptive pamphlet from I-2683.

  10. Contribution of Elasticity in Slab Bending

    NASA Astrophysics Data System (ADS)

    Fourel, L.; Goes, S. D. B.; Morra, G.

    2014-12-01

    Previous studies have shown that plate rheology exerts a dominant control on the shape and velocity of subducting plates. Here, we perform a systematic investigation of the, often disregarded, role of elasticity in slab bending at the trench, using simple, yet fully dynamic, set of 2.5D models where an elastic, visco-elastic or visco-elasto-plastic plate subducts freely into a purely viscous mantle. We derive a scaling relationship between the bending radius of visco-elastic slabs and the Deborah number, De, which is the ratio of Maxwell time over deformation time. We show that De controls the ratio of elastically stored energy over viscously dissipated energy and find that at De exceeding 10-2, it requires substantially less energy to bend a visco-elastic slab to the same shape as a purely viscous slab with the same viscosity (90% less for De=0.1). Elastically stored energy at higher De facilitates slab unbending and hence favours retreating modes of subduction, while trench advance only occurs for some cases with De<10-2. We use our scaling relation to estimate apparent Deborah numbers, Deapp, from a global compilation of subduction-zone parameters. Values range from 10-3 to >1, where most zones have low Deapp<10-2, but a few young plates have Deapp>0.1. Slabs with Deapp ≤ 10-2 either have very low viscosities, ≤10 times mantle viscosity, or they may be yielding, in which case our apparent Deborah number may underestimate actual De by up to an order of magnitude. If a significant portion of the low Deapp slabs yield, then elastically stored energy may actually be important in quite a large number of subduction zones. Interestingly, increasing Deapp correlates with increasing proportion of larger seismic events (b-value) in both instrumental and historic catalogues, indicating that increased contribution of elasticity may facilitate rupture in larger, less frequent earthquakes.

  11. A two-dimensional analytical model describing groundwater level fluctuations in an anisotropic and bending leaky aquifer system near estuary

    NASA Astrophysics Data System (ADS)

    Yeh, Hund-Der; Chuang, Mo-Hsiung

    2014-05-01

    Tide-induced head fluctuation in a two-dimensional estuarine aquifer system is complicated and rather important in dealing with many groundwater management or remediation problems. The conceptual model of the aquifer system we considered is anisotropic, multi-layered with a bending estuarine bank, and subject to the tidal fluctuation effects from both the sea shore and estuarine river. The solution of the model describing the groundwater head distribution in such a coastal aquifer system is developed based on the method of separation of variables and a coordinate transformation applied to the river boundary at the bend with an angle of arbitrary degree to the line perpendicular to the sea shore. The solutions by Sun (Sun H. A two-dimensional analytical solution of groundwater response to tidal loading in an estuary, Water Resour. Res. 1997; 33:1429-35) as well as Tang and Jiao (Tang Z. and J. J. Jiao, A two-dimensional analytical solution for groundwater flow in a leaky confined aquifer system near open tidal water, Hydrological Processes, 2001; 15: 573-585) can be shown to be special cases of the present solution if the degree of the bending angle is zero. On the basis of the analytical solution, the groundwater head distribution in response to estuarine boundary is examined and the influences of anisotropy, leakage, hydraulic parameters, and bending angle on the groundwater head fluctuation are investigated and discussed.

  12. Great Bend tornadoes of August 30, 1974

    NASA Technical Reports Server (NTRS)

    Umenhofer, T. A.; Fujita, T. T.; Dundas, R.

    1977-01-01

    Photogrammetric analyses of movies and still pictures taken of the Great Bend, Kansas Tornado series have been used to develop design specifications for nuclear power plants and facilities. A maximum tangential velocity of 57 m/sec and a maximum vertical velocity of 27 m/sec are determined for one suction vortex having a translational velocity of 32 m/sec. Three suction vortices with radii in the 20 to 30 m range are noted in the flow field of one tornado; these suction vortices apparently form a local convergence of inflow air inside the outer portion of the tornado core.

  13. Self-bending symmetric cusp beams

    SciTech Connect

    Gong, Lei; Liu, Wei-Wei; Lu, Yao; Li, Yin-Mei; Ren, Yu-Xuan

    2015-12-07

    A type of self-bending symmetric cusp beams with four accelerating intensity maxima is theoretically and experimentally presented. Distinguished from the reported regular polygon beams, the symmetric cusp beams simultaneously exhibit peculiar features of natural autofocusing and self-acceleration during propagation. Further, such beams take the shape of a fine longitudinal needle-like structure at the focal region and possess the strong ability of self-healing over obstacles. All these intriguing properties were verified experimentally. Particularly, the spatial profile of the reconstructed beam exhibits spatially sculpted optical structure with four siamesed curved arms. Thus, we anticipate that the structured beam will benefit optical guiding and optofluidics in surprising ways.

  14. Self-bending symmetric cusp beams

    NASA Astrophysics Data System (ADS)

    Gong, Lei; Liu, Wei-Wei; Ren, Yu-Xuan; Lu, Yao; Li, Yin-Mei

    2015-12-01

    A type of self-bending symmetric cusp beams with four accelerating intensity maxima is theoretically and experimentally presented. Distinguished from the reported regular polygon beams, the symmetric cusp beams simultaneously exhibit peculiar features of natural autofocusing and self-acceleration during propagation. Further, such beams take the shape of a fine longitudinal needle-like structure at the focal region and possess the strong ability of self-healing over obstacles. All these intriguing properties were verified experimentally. Particularly, the spatial profile of the reconstructed beam exhibits spatially sculpted optical structure with four siamesed curved arms. Thus, we anticipate that the structured beam will benefit optical guiding and optofluidics in surprising ways.

  15. Bending of light in quantum gravity.

    PubMed

    Bjerrum-Bohr, N E J; Donoghue, John F; Holstein, Barry R; Planté, Ludovic; Vanhove, Pierre

    2015-02-13

    We consider the scattering of lightlike matter in the presence of a heavy scalar object (such as the Sun or a Schwarzschild black hole). By treating general relativity as an effective field theory we directly compute the nonanalytic components of the one-loop gravitational amplitude for the scattering of massless scalars or photons from an external massive scalar field. These results allow a semiclassical computation of the bending angle for light rays grazing the Sun, including long-range ℏ contributions. We discuss implications of this computation, in particular, the violation of some classical formulations of the equivalence principle. PMID:25723201

  16. Mixed-Mode-Bending Delamination Apparatus

    NASA Technical Reports Server (NTRS)

    Crews, John H., Jr.; Reeder, James R.

    1991-01-01

    Mixed-mode-bending delamination apparatus generates two types of delamination stress simultaneously in specimen from single externally applied point load. In technique, indivial mode I and mode II contributions to delamination in specimen analyzed by use of simple beam-theory equations, eliminating need for time-consuming, difficult numerical analysis. Allows wider range of mode I/mode II ratios than possible with many other methods. Mixed-mode delamination testing of interest in all fields utilizing composite materials, used mostly in aerospace field, but also used in automobiles, lightweight armored military vehicles, boats, and sporting equipment. Useful in general lumber, plywood, and adhesive industries, as well.

  17. Bending and buckling of wet paper

    NASA Astrophysics Data System (ADS)

    Lee, Minhee; Kim, Seungho; Kim, Ho-Young; Mahadevan, L.

    2016-04-01

    Flat paper stained with water buckles and wrinkles as it swells and deforms out of the original plane. Here we quantify the geometry and mechanics of a strip of paper that swells when it imbibes water from a narrow capillary. Characterizing the hygroexpansive nature of paper shows that thickness-wise swelling is much faster than in-plane water imbibition, leading to a simple picture for the process by which the strip of paper bends out of the plane. We model the out-of-plane deformation using a quasi-static theory and show that our results are consistent with quantitative experiments.

  18. Internal connectivity of meandering rivers: Statistical generalization of channel hydraulic geometry

    NASA Astrophysics Data System (ADS)

    Czapiga, M. J.; Smith, V. B.; Nittrouer, J. A.; Mohrig, D.; Parker, G.

    2015-09-01

    The geometry of rivers has been characterized in terms of downstream and at-a-station hydraulic geometry, based on individual cross sections. Such analyses do not, however, provide insight as to how these cross sections are connected. We generalize the concept of hydraulic geometry, using data on bathymetry from four reaches of meandering rivers that include at least five bends. We quantify connectivity in terms of the probability that a connected path exists such that a given attribute remains within specified bounds along it. While the concept is general, here we apply it to vessel navigability. We develop a predictor for navigability in meandering rivers, which requires only the following, relatively easily obtained input: vessel draft, vessel width, bankfull depth, bankfull width, relative difference between current and bankfull water surface elevation, and length of desired navigation path. The predictor is applicable to both bankfull and below-bankfull stage. A key input parameter is the standard deviation of the probability distribution of depth. This parameter, in and of itself, yields no information on connectivity as it does not capture the spatial orientation of depth variation. We find, however, that (a) the probability function for connectivity does depend on this parameter, and (b) its use allows for an approximate similarity collapse of the probability function, so providing a quasi-universal predictive relation applying to all four reaches. The results also suggest potential application to more complex forms for connectivity that involve other or multiple in-stream physical variables.

  19. 76 FR 56638 - Safety Zone; Head of the Cuyahoga, Cuyahoga River, Cleveland, OH

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-14

    ... 41.29'19'' N, 81.40'50'' W (Marathon Bend) to a line drawn perpendicular to each river bank at 41.29... perpendicular to each riverbank at 41.29'19'' N, 81.40'50'' W (Marathon Bend) to a line drawn perpendicular...

  20. Multifiber optical bend sensor to aid colonoscope navigation

    NASA Astrophysics Data System (ADS)

    Kesner, Jessica E.; Gavalis, Robb M.; Wong, Peter Y.; Cao, Caroline G. L.

    2011-12-01

    A colonoscopy's near-blind navigation process frequently causes disorientation for the scope operator, leading to harm for the patient. Navigation can be improved if real-time colonoscope shape, location, and orientation information is provided by a shape-tracking aid, such as a fiber optic bend sensor. Fiber optic bend sensors provide advantages over conventional electromechanical shape-trackers, including low cost and ease of integration. However, current fiber optic bend sensors lack either the ability to detect both bending direction and curvature, or the ability to detect multiple localized bends. An inexpensive multifiber bend sensor was developed to aid users in navigation during colonoscopy. The bend sensor employs active-cladding optical fibers modified with fluorescent quantum dots, bandpass filters, and a complementary metal-oxide-semiconductor imager as key components. Results from three-fiber sensors demonstrate the bend sensor's ability to measure curvature (error of 0.01 mm), direction (100% accuracy), and location (predetermined distance) of a bend in the fiber bundle. Comparison with spectroscopy data further confirmed the accuracy of the bending direction measurement for a three-fiber sensor. Future work includes improvements in fiber manufacturing to increase sensor sensitivity and consistency. An expanded 31 fiber bundle would be needed to track the full length of a colonoscope.

  1. The design of an agent to bend DNA.

    PubMed Central

    Akiyama, T; Hogan, M E

    1996-01-01

    An artificial DNA bending agent has been designed to assess helix flexibility over regions as small as a protein binding site. Bending was obtained by linking a pair of 15-base-long triple helix forming oligonucleotides (TFOs) by an adjustable polymeric linker. By design, DNA bending was introduced into the double helix within a 10-bp spacer region positioned between the two sites of 15-base triple helix formation. The existence of this bend has been confirmed by circular permutation and phase-sensitive electrophoresis, and the directionality of the bend has been determined as a compression of the minor helix groove. The magnitude of the resulting duplex bend was found to be dependent on the length of the polymeric linker in a fashion consistent with a simple geometric model. Data suggested that a 50-70 degrees bend was achieved by binding of the TFO chimera with the shortest linker span (18 rotatable bonds). Equilibrium analysis showed that, relative to a chimera which did not bend the duplex, the stability of the triple helix possessing a 50-70 degrees bend was reduced by less than 1 kcal/mol of that of the unbent complex. Based upon this similarity, it is proposed that duplex DNA may be much more flexible with respect to minor groove compression than previously assumed. It is shown that this unusual flexibility is consistent with recent quantitation of protein-induced minor groove bending. Images Fig. 2 Fig. 3 PMID:8901543

  2. Nonlinear Bending Stiffness of Plates Clamped by Bolted Joints under Bending Moment

    NASA Astrophysics Data System (ADS)

    Naruse, Tomohiro; Shibutani, Yoji

    Equivalent stiffness of plates clamped by bolted joints for designing should be evaluated according to not only the strength of bolted joints but also the deformation and vibration characteristics of the structures. When the applied external axial load or the bending moment is sufficiently small, the contact surfaces of the bolted joint are stuck together, and thus both the bolt and the clamped plates deform linearly. Although the sophisticated VDI 2230 code gives the appropriate stiffness of clamped plates for the infinitesimal deformation, the stiffness may vary nonlinearly with increasing the loading because of changing the contact state. Therefore, the present paper focuses on the nonlinear behaviour of the bending stiffness of clamped plates by using Finite Element (FE) analyses, taking the contact condition on bearing surfaces and between the plates into account. The FE models of the plates with thicknesses of 3.2, 4.5, 6.0 and 9.0 mm tightened with M8, 10, 12 and 16 bolts were constructed. The relation between bending moment and bending compliance of clamped plates is found to be categorized into three regions, namely, (i) constant compliance with fully stuck contact surfaces, (ii) transition showing the nonlinear compliance, and (iii) constant compliance with one-side contact surfaces. The mechanical models for these three regions are proposed and compared with FEM solutions. The prediction on the bounds of three regions is in a fairly good agreement except the case with smaller bolts and thicker plates.

  3. Guided Wave Travel Time Tomography for Bends

    NASA Astrophysics Data System (ADS)

    Volker, Arno; Bloom, Joost

    2011-06-01

    The concept of predictive maintenance using permanent sensors that monitor the integrity of an installation is an interesting addition to the current method of periodic inspections. Guided wave tomography has been developed to map the wall thickness using the travel times of guided waves. The method has been demonstrated for straight pipes. The extension of this method to bends is not straightforward because natural focusing occurs due to geometrical path differences. This yields a phase jump, which complicates travel time picking. Because ray-tracing is no longer sufficient to predict the travel times a recursive wave field extrapolation has been developed. The method uses a short spatial convolution operator to propagate a wave field through a bend. The method allows to calculate the wave field at the detector ring, including the phase jump as a consequence of the natural focusing. The recursive wave field extrapolation is done in the space-frequency domain. Therefore dispersion effects can be included easily in the forward modeling. Comparison with measurements shows the accuracy of the method.

  4. The Danube Bend, Hungary - proposal for its recognition as a geoheritage

    NASA Astrophysics Data System (ADS)

    Karátson, Dávid

    2016-04-01

    The Danube Bend in North Hungary is a river curvature along the Danube river, cut into a rocky section that reveals Miocene volcanic sucessions. The deepest and narrowest part of the curvature, 5 km in diameter (called Visegrád Gorge), is one of the most picturesque landscapes in Hungary. There, the Danube, before changing its direction toward the south, forms a U-shaped valley in planform - a peculiar shape that has been an enigmatic issue in Hungarian earth sciences since the 19th century. A number of geomorphological theories have been put forward for the origin of the valley, which is incised between remnants of ca. 16 Ma old, small-sized dacitic stratovolcanoes of the Börzsöny Mts to the north, and the ~15 Ma Keserűs Hill lava dome complex to the south, all of which emerged in a contemporaneous archipelago (existent up to Pannonian times). According to Karátson et al. (2006), the U-shaped loop is partly inherited from a late-stage horseshoe caldera morphology of Keserűs Hill volcano, open to the north. Several Ma later, the formation of the Danube Bend was initiated by river incision, removing the post-volcanic sedimentary cover in mid- or rather, late Pleistocene times. Fluvial processes and erosion in turn were triggered by mountain uplift, climate changes, and drop of remote erosion base level. The present curvature of the river was controlled by the exhumation of the horseshoe caldera as well as the surrounding resistant volcaniclastic rocks (e.g. Visegrád Castle Hill) and a hilltop lava dome (Szent Mihály Hill). Moreover, an early-stage meander of Danube may have also inherited. The accelerated Late Quaternary erosion and intense dissection has resulted in a "re-birth" of the volcanic relief, which exhibits again steep slopes to form the spectacular gorge. At present, exposed rock formations (e.g. Vadálló-kövek) tower above the Danube Bend, making the area one of the most scenic landscape in East-Central Europe. Therefore, in 1997, the Danube

  5. Precision Small Angle Bending of Sheet Metals Using Shear Deformation

    NASA Astrophysics Data System (ADS)

    Hirota, Kenji; Mori, Yorifumi

    This paper deals with a new method to bend sheet metals at a small angle precisely, in which a sheet metal is slightly bent by shear deformation at negative punch-die clearance. Deformation behavior and key factors affecting on the bend angle were studied in detail with pure aluminum sheets. It was proved that the bend angle was changed in proportion to both punch penetration and negative punch-die clearance within a certain range. The same was true for high-strength steel and phosphor bronze, which are difficult to bend precisely by conventional methods due to large springback after unloading. By using this relationship as a control law, four kinds of sheet metals were precisely bent within a few degrees. This method was applied to correct the angular errors in U-bend products of high-strength steel and to bend leaf springs of phosphor bronze at an arbitrary small angle.

  6. Bending strain tolerance of MgB2 superconducting wires

    NASA Astrophysics Data System (ADS)

    Kováč, P.; Hušek, I.; Melišek, T.; Kulich, M.; Kopera, L.

    2016-04-01

    This work describes the strain tolerance of MgB2 superconductors subjected to variable bending stresses. Bending of MgB2 wire was done at room temperature in different modes: (i) direct bending of straight annealed samples to variable diameters and by (ii) indirect bending by straightening of bent and annealed samples. I c-bending strain characteristics of samples made by in situ PIT and by the internal magnesium diffusion (IMD) process were measured at 4.2 K. The results show a good agreement between the direct and indirect bending mode, which allows easier estimation of limits important for the winding process of MgB2 superconductors with brittle filaments. A comparison of MgB2 wires made by in situ PIT and IMD processes showed improved strain tolerance for IMD due to better grain connectivity the low annealing temperature, which does not appear to reduce the mechanical strength of sheath material.

  7. Space Station Power System

    NASA Technical Reports Server (NTRS)

    Baraona, C. R.

    1984-01-01

    The strategies, reasoning, and planning guidelines used in the development of the United States Space Station Program are outlined. The power required to support Space Station missions and housekeeping loads is a key driver in overall Space Station design. conversely, Space Station requirements drive the power technology. Various power system technology options are discussed. The mission analysis studies resulting in the required Space Station capabilities are also discussed. An example of Space Station functions and a concept to provide them is presented. The weight, area, payload and altitude requirements on draft and mass requirements are described with a summary and status of key power systems technology requirements and issues.

  8. Space Station power system

    SciTech Connect

    Baraona, C.R.

    1984-04-01

    The strategies, reasoning, and planning guidelines used in the development of the United States Space Station Program are outlined. The power required to support Space Station missions and housekeeping loads is a key driver in overall Space Station design. conversely, Space Station requirements drive the power technology. Various power system technology options are discussed. The mission analysis studies resulting in the required Space Station capabilities are also discussed. An example of Space Station functions and a concept to provide them is presented. The weight, area, payload and altitude requirements on draft and mass requirements are described with a summary and status of key power systems technology requirements and issues.

  9. 23. Station Compressor Room 1 with Air Compressors and Accumulator ...

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

    23. Station Compressor Room 1 with Air Compressors and Accumulator Tanks, view to the south. One of the two large station air compressor units used for depressing the draft tube water level is visible atop a concrete pedestal on the left side of photograph (the second identical compressor is located in an adjacent room). Two of the six station air accumulator tanks are visible in the background. The smaller station service air compressor is visible in right foreground of the photograph was installed in the early 1980s, and replaced the original station service air compressor. - Washington Water Power Clark Fork River Noxon Rapids Hydroelectric Development, Powerhouse, South bank of Clark Fork River at Noxon Rapids, Noxon, Sanders County, MT

  10. Transient Pinning and Pulling: A Mechanism for Bending Microtubules.

    PubMed

    Kent, Ian A; Rane, Parag S; Dickinson, Richard B; Ladd, Anthony J C; Lele, Tanmay P

    2016-01-01

    Microtubules have a persistence length of the order of millimeters in vitro, but inside cells they bend over length scales of microns. It has been proposed that polymerization forces bend microtubules in the vicinity of the cell boundary or other obstacles, yet bends develop even when microtubules are polymerizing freely, unaffected by obstacles and cell boundaries. How these bends are formed remains unclear. By tracking the motions of microtubules marked by photobleaching, we found that in LLC-PK1 epithelial cells local bends develop primarily by plus-end directed transport of portions of the microtubule contour towards stationary locations (termed pinning points) along the length of the microtubule. The pinning points were transient in nature, and their eventual release allowed the bends to relax. The directionality of the transport as well as the overall incidence of local bends decreased when dynein was inhibited, while myosin inhibition had no observable effect. This suggests that dynein generates a tangential force that bends microtubules against stationary pinning points. Simulations of microtubule motion and polymerization accounting for filament mechanics and dynein forces predict the development of bends of size and shape similar to those observed in cells. Furthermore, simulations show that dynein-generated bends at a pinning point near the plus end can cause a persistent rotation of the tip consistent with the observation that bend formation near the tip can change the direction of microtubule growth. Collectively, these results suggest a simple physical mechanism for the bending of growing microtubules by dynein forces accumulating at pinning points. PMID:26974838

  11. Bending response of single layer MoS2.

    PubMed

    Xiong, Si; Cao, Guoxin

    2016-03-11

    Using molecular mechanics (or dynamics) simulations, three different approaches, including the targeted molecular mechanics, four-point bending and nanotube methods, are employed to investigate the bending response of single layer MoS2 (SLMoS2), among which four-point bending is the most accurate approach to determine the bending stiffness according to the continuum theory. It is found that when the bending curvature radius is large enough (e.g. >4 nm), three approaches will give the same bending stiffness of SLMoS2 and the bending behavior is isotropic for SLMoS2, whereas the nanotube method with small tubes (e.g. <4 nm) cannot give the correct bending stiffness. Compared with the reported result from the MoS2 nanotube calculated by density functional theory, the revised Stillinger-Weber (SW) and reactive empirical bond-order (REBO) potentials can give the reasonable bending stiffness of SLMoS2 (8.7-13.4 eV) as well as the effective deformed conformation. In addition, since the Mo-S bond deformation of SLMoS2 under bending is similar to that under in-plane tension/compression, the continuum bending theory can quite accurately predict the bending stiffness of SLMoS2 if a reasonable thickness of SLMoS2 is given. For SLMoS2, the reasonable thickness should be larger than the distance between its two S atomic planes and lower than the distance between two Mo atomic planes of bulk MoS2 crystal, e.g. 0.375-0.445 nm. PMID:26861930

  12. The mechanics of gravitropic bending in leafy dicot stems

    NASA Technical Reports Server (NTRS)

    Salisbury, F. B.; Mueller, W. J.; Blotter, P. T.; Harris, C. S.; White, R. G.; Gillespie, L. S.; Sliwinski, J. E.

    1982-01-01

    The mechanism of the gravitropic bending in stems of the cocklebur and castor bean are investigated. The results of these experiments demonstrate the quick stopping of growth and the increased tensions on the upper layer of a horizontal stem. It is suggested that bending apparently occurs as the resistance of the upper surface layers is extended to the inner cells below. A model of stem bending is developed which can explain the asymmetry of the stem-cell response.

  13. Transient Pinning and Pulling: A Mechanism for Bending Microtubules

    PubMed Central

    Kent, Ian A.; Rane, Parag S.; Dickinson, Richard B.; Ladd, Anthony J. C.; Lele, Tanmay P.

    2016-01-01

    Microtubules have a persistence length of the order of millimeters in vitro, but inside cells they bend over length scales of microns. It has been proposed that polymerization forces bend microtubules in the vicinity of the cell boundary or other obstacles, yet bends develop even when microtubules are polymerizing freely, unaffected by obstacles and cell boundaries. How these bends are formed remains unclear. By tracking the motions of microtubules marked by photobleaching, we found that in LLC-PK1 epithelial cells local bends develop primarily by plus-end directed transport of portions of the microtubule contour towards stationary locations (termed pinning points) along the length of the microtubule. The pinning points were transient in nature, and their eventual release allowed the bends to relax. The directionality of the transport as well as the overall incidence of local bends decreased when dynein was inhibited, while myosin inhibition had no observable effect. This suggests that dynein generates a tangential force that bends microtubules against stationary pinning points. Simulations of microtubule motion and polymerization accounting for filament mechanics and dynein forces predict the development of bends of size and shape similar to those observed in cells. Furthermore, simulations show that dynein-generated bends at a pinning point near the plus end can cause a persistent rotation of the tip consistent with the observation that bend formation near the tip can change the direction of microtubule growth. Collectively, these results suggest a simple physical mechanism for the bending of growing microtubules by dynein forces accumulating at pinning points. PMID:26974838

  14. BEND3 mediates transcriptional repression and heterochromatin organization.

    PubMed

    Khan, Abid; Prasanth, Supriya G

    2015-01-01

    Transcription repression plays a central role in gene regulation. Transcription repressors utilize diverse strategies to mediate transcriptional repression. We have recently demonstrated that BEND3 (BANP, E5R and Nac1 domain) protein represses rDNA transcription by stabilizing a NoRC component. We discuss the role of BEND3 as a global regulator of gene expression and propose a model whereby BEND3 associates with chromatin remodeling complexes to modulate gene expression and heterochromatin organization. PMID:26507581

  15. Compliance measurements of chevron notched four point bend specimen

    NASA Technical Reports Server (NTRS)

    Calomino, Anthony; Bubsey, Raymond; Ghosn, Louis J.

    1994-01-01

    The experimental stress intensity factors for various chevron notched four point bend specimens are presented. The experimental compliance is verified using the analytical solution for a straight through crack four point bend specimen and the boundary integral equation method for one chevron geometry. Excellent agreement is obtained between the experimental and analytical results. In this report, stress intensity factors, loading displacements and crack mouth opening displacements are reported for different crack lengths and different chevron geometries, under four point bend loading condition.

  16. Bending response of single layer MoS2

    NASA Astrophysics Data System (ADS)

    Xiong, Si; Cao, Guoxin

    2016-03-01

    Using molecular mechanics (or dynamics) simulations, three different approaches, including the targeted molecular mechanics, four-point bending and nanotube methods, are employed to investigate the bending response of single layer MoS2 (SLMoS2), among which four-point bending is the most accurate approach to determine the bending stiffness according to the continuum theory. It is found that when the bending curvature radius is large enough (e.g. >4 nm), three approaches will give the same bending stiffness of SLMoS2 and the bending behavior is isotropic for SLMoS2, whereas the nanotube method with small tubes (e.g. <4 nm) cannot give the correct bending stiffness. Compared with the reported result from the MoS2 nanotube calculated by density functional theory, the revised Stillinger-Weber (SW) and reactive empirical bond-order (REBO) potentials can give the reasonable bending stiffness of SLMoS2 (8.7-13.4 eV) as well as the effective deformed conformation. In addition, since the Mo-S bond deformation of SLMoS2 under bending is similar to that under in-plane tension/compression, the continuum bending theory can quite accurately predict the bending stiffness of SLMoS2 if a reasonable thickness of SLMoS2 is given. For SLMoS2, the reasonable thickness should be larger than the distance between its two S atomic planes and lower than the distance between two Mo atomic planes of bulk MoS2 crystal, e.g. 0.375-0.445 nm.

  17. EAST GALLATIN RIVER, MONTANA: MACROINVERTEBRATE DISTRIBUTION AND WATER ANALYSIS 1973-1974

    EPA Science Inventory

    Macroinvertebrate samples from seven stations and water chemistry samples from 10 stations in the East Gallatin River, Montana, were collected on thirteen dates throughout the year between June 1973 and August 1974. The stations were selected to cover a stretch of the river both ...

  18. Static Fatigue of Optical Fibers in Bending

    NASA Astrophysics Data System (ADS)

    Roberts, D.; Cuellar, E.; Middleman, L.; Zucker, J.

    1987-02-01

    While delayed fracture, or static fatigue, of optical fibers is well known, it is not well understood, and the prediction of the time to failure under a given set of conditions can be problematic. Unlike short term fracture, which is quite well understood and quantified in terms of the theory of linear elastic fracture mechanics, the long term strength remains empirical. The goal of this study is to determine the design criteria for optical fibers subjected to long term applied mechanical loads. One difficulty in making lifetime predictions, as pointed out by Matthewson (Reference 1) and others, is that predictions made from data taken in tension and in bending do not agree. Another difficulty is the statistical nature of the fracture of glass. In making lifetime predictions it becomes important therefore that one (a) have ample data for statistical analysis and (b) have data for the loading configuration of interest. This is the purpose of our work. Since there is less data available in bending, and since several applications (such as wiring in aircraft and missiles) require bending, the data are taken in that configuration. The most significant finding in our work so far is the very large difference in static fatigue behavior between buffer coatings. Chandan and Kalish (Reference 2) and others have reported static fatigue curves, log (time to failure) versus log (applied stress), which are not linear, but rather bimodal. Our study confirms this result, but so far only for acrylate coated fibers. Silicone coated fibers show unimodal behavior. That is, the log (time to failure) versus log (applied stress) curve is linear, at least on the time scale studied so far. Data for acrylate coated fibers at 80°C in water are linear only for time scales of about one day, where a pronounced "knee" is observed. Data for silicone coated fibers under the same conditions are linear up to at least 6 months. Longer time scale tests and tests on fibers with other buffer materials

  19. PERMEABILITY OF SALTSTONE MEASUREMENT BY BEAM BENDING

    SciTech Connect

    Harbour, J; Tommy Edwards, T; Vickie Williams, V

    2008-01-30

    One of the goals of the Saltstone variability study is to identify (and, quantify the impact of) the operational and compositional variables that control or influence the important processing and performance properties of Saltstone mixes. A performance property for Saltstone mixes that is important but not routinely measured is the liquid permeability or saturated hydraulic conductivity of the cured Saltstone mix. The value for the saturated hydraulic conductivity is an input into the Performance Assessment for the SRS Z-Area vaults. Therefore, it is important to have a method available that allows for an accurate and reproducible measurement of permeability quickly and inexpensively. One such method that could potentially meet these requirements for the measurement of saturated hydraulic conductivity is the technique of beam bending, developed by Professor George Scherer at Princeton University. In order to determine the feasibility of this technique for Saltstone mixes, a summer student, David Feliciano, was hired to work at Princeton under the direction of George Scherer. This report details the results of this study which demonstrated the feasibility and applicability of the beam bending method to measurement of permeability of Saltstone samples. This research effort used samples made at Princeton from a Modular Caustic side solvent extraction Unit based simulant (MCU) and premix at a water to premix ratio of 0.60. The saturated hydraulic conductivities for these mixes were measured by the beam bending technique and the values determined were of the order of 1.4 to 3.4 x 10{sup -9} cm/sec. These values of hydraulic conductivity are consistent with independently measured values of this property on similar MCU based mixes by Dixon and Phifer. These values are also consistent with the hydraulic conductivity of a generic Saltstone mix measured by Langton in 1985. The high water to premix ratio used for Saltstone along with the relatively low degree of hydration for

  20. Bending waves and the structure of Saturn's rings

    NASA Technical Reports Server (NTRS)

    Lissauer, J. J.

    1985-01-01

    The surface mass density profiles at four locations within Saturn's rings are calculated using Voyager spacecraft images of spiral bending waves. The identification of a feature in Saturn's outer B ring as Mimas's 4:2 bending waves is confirmed, and these 4:2 waves are analyzed to determine the surface density in Saturn's B ring. A fourth set of bending waves, the Mimas 7:4, located in the inner A ring, is identified and analyzed. Mimas's 5:3 and 8:5 bending waves, observed in the middle and outer A ring respectively, are reanalyzed.

  1. Sorting of bed load sediment by flow in meander bends.

    USGS Publications Warehouse

    Parker, G.; Andrews, E.D.

    1985-01-01

    Equilibrium sorting of coarse mobile bed load sediment in meander bends is considered. A theory of two-dimensional bed load transport of graded material, including the effects of gravity on lateral slopes and secondary currents, is developed. This theory is coupled with a simple tratement of flow in bends, an analytically determined bend shape, and the condition of continuity of each grain size range in transport to describe sorting. The theory indicates that the locus of coarse sediment shifts from the inside bank to the outside bank near the bend apex, as is observed.-Authors

  2. Adaptive waveguide bends with homogeneous, nonmagnetic, and isotropic materials.

    PubMed

    Han, Tiancheng; Qiu, Cheng-Wei; Tang, Xiaohong

    2011-01-15

    We propose a method for adaptive waveguide bends using homogeneous, nonmagnetic, and isotropic materials, which simplifies the parameters of the bends to the utmost extent. The proposed bend has an adaptive and compact shape because of all the flat boundaries. The nonmagnetic property is realized by selecting OB'/OC = 0.5. Only two nonmagnetic isotropic dielectrics are needed throughout, and the transmission is not sensitive to nonmagnetic isotropic dielectrics. Results validate and illustrate these functionalities, which make the bend much easier to fabricate and apply, owing to its simple parameters, compact shape, and versatility in connecting different waveguides. PMID:21263493

  3. Fatigue life prediction in bending from axial fatigue information

    NASA Technical Reports Server (NTRS)

    Manson, S. S.; Muralidharan, U.

    1982-01-01

    Bending fatigue in the low cyclic life range differs from axial fatigue due to the plastic flow which alters the linear stress-strain relation normally used to determine the nominal stresses. An approach is presented to take into account the plastic flow in calculating nominal bending stress (S sub bending) based on true surface stress. These functions are derived in closed form for rectangular and circular cross sections. The nominal bending stress and the axial fatigue stress are plotted as a function of life (N sub S) and these curves are shown for several materials of engineering interest.

  4. Rawhide Energy Station, Fort Collins, Colorado

    SciTech Connect

    Peltier, R.

    2008-10-15

    The staff of Platte River Power Authority's Rawhide Energy Station have been racking up operating stats and an environmental performance record that is the envy of other plant managers. In the past decade Rawhide has enjoyed an equivalent availability factor in the mid to high 90s and an average capacity factor approaching 90%. Still not content with this performance, Rawhide invested in new technology and equipment upgrades to further optimise performance, reduce emissions, and keep cost competitive. The Energy Station includes four GE France 7EA natural gas-fired turbines totalling 260 MW and a 274 MW coal-fired unit located in northeastern Colorado. 7 figs.

  5. Space station automation II

    SciTech Connect

    Chiou, W.C.

    1986-01-01

    This book contains the proceedings of a conference on space station automation. Topics include the following: distributed artificial intelligence for space station energy management systems and computer architecture for tolerobots in earth orbit.

  6. Station Tour: Russian Segment

    NASA Video Gallery

    Expedition 33 Commander Suni Williams concludes her tour of the International Space Station with a visit to the Russian segment, which includes Zarya, the first segment of the station launched in 1...

  7. Space station power system

    NASA Technical Reports Server (NTRS)

    Forestieri, A. F.; Baraona, C. R.

    1984-01-01

    It is pointed out that space station planning at NASA began when NASA was created in 1958. However, the initiation of the program for a lunar landing delayed the implementation of plans for a space station. The utility of a space station was finally demonstrated with Skylab, which was launched in 1972. In May 1982, the Space Station Task Force was established to provide focus and direction for space station planning activities. The present paper provides a description of the planning activities, giving particular attention to the power system. The initial space station will be required to supply 75 kW of continuous electrical power, 60 kW for the customer and 15 kW for space station needs. Possible alternative energy sources for the space station include solar planar or concentrator arrays of either silicon or gallium arsenide.

  8. Dynamic characteristics of power-tower space stations with 15-foot truss bays

    NASA Technical Reports Server (NTRS)

    Dorsey, J. T.

    1986-01-01

    A power tower space station concept which generates power with photovoltaic arrays and where the truss structure has a bay size of 15 ft is described. Rigid body and flexible body dynamic characteristics are presented for a 75-kW Initial Operating Capability (IOC) and 150-kW and 300-kW growth stations. The transient response of the IOC and 300-kW growth stations to shuttle dock, orbit reboost, and mobile remote manipulator system translation loads are studied. Displacements, accelerations, and bending moments at various locations on the IOC and 300-kW growth stations are presented.

  9. Separation of blood in microchannel bends

    NASA Astrophysics Data System (ADS)

    Blattert, Christoph; Jurischka, Reinhold; Schoth, Andreas; Kerth, Paul; Menz, Wolfgang

    2004-01-01

    Biological applications of micro assay devices require integrated on-chip microfluidics for separation of plasma or serum from blood. This is achieved by a new blood separation technique based on a microchannel bend structure developed within the collaborative Micro-Tele-BioChip (μTBC) project co-funded by the German Ministry For Education and Research (BMBF). Different prototype polymer chips have been manufactured with an UV-LIGA process and hot embossing technology. The separation efficiency of these chips has been determined by experimental measurements using human whole blood. Results show different separation efficiencies for cells and plasma depending on microchannel geometry and blood sample characteristics and suggest an alternative blood separation method as compared to existing micro separation technologies.

  10. Separation of blood in microchannel bends

    NASA Astrophysics Data System (ADS)

    Blattert, Christoph; Jurischka, Reinhold; Schoth, Andreas; Kerth, Paul; Menz, Wolfgang

    2003-12-01

    Biological applications of micro assay devices require integrated on-chip microfluidics for separation of plasma or serum from blood. This is achieved by a new blood separation technique based on a microchannel bend structure developed within the collaborative Micro-Tele-BioChip (μTBC) project co-funded by the German Ministry For Education and Research (BMBF). Different prototype polymer chips have been manufactured with an UV-LIGA process and hot embossing technology. The separation efficiency of these chips has been determined by experimental measurements using human whole blood. Results show different separation efficiencies for cells and plasma depending on microchannel geometry and blood sample characteristics and suggest an alternative blood separation method as compared to existing micro separation technologies.

  11. Bending the Cost Curve in Childhood Cancer.

    PubMed

    Russell, Heidi; Bernhardt, M Brooke

    2016-08-01

    Healthcare for children with cancer costs significantly more than other children. Cost reduction efforts aimed toward relatively small populations of patients that use a disproportionate amount of care, like childhood cancer, could have a dramatic impact on healthcare spending. The aims of this review are to provide stakeholders with an overview of the drivers of financial costs of childhood cancer and to identify possible directions to curb or decrease these costs. Costs are incurred throughout the spectrum of care. Recent trends in pharmaceutical costs, evidence identifying the contribution of administration costs, and overuse of surveillance studies are described. Awareness of cost and value, i.e., the outcome achieved per dollar or burden spent, in delivery of care and research is necessary to bend the cost curve. Incorporation of these dimensions of care requires methodology development, prioritization, and ethical balance. PMID:27193602

  12. A comparison of needle bending models.

    PubMed

    Dehghan, Ehsan; Goksel, Orcun; Salcudean, Septimiu E

    2006-01-01

    Modeling the deflection of flexible needles is an essential part of needle insertion simulation and path planning. In this paper, three models are compared in terms of accuracy in simulating the bending of a prostate brachytherapy needle. The first two utilize the finite element method, one using geometric non-linearity and triangular plane elements, the other using non-linear beam elements. The third model uses angular springs to model cantilever deflection. The simulations are compared with the experimental bent needle configurations. The models are assessed in terms of geometric conformity using independently identified and pre-identified model parameters. The results show that the angular spring model, which is also the simplest, simulates the needle more accurately than the others. PMID:17354904

  13. Pure bending of a solid cone

    NASA Astrophysics Data System (ADS)

    Renton, J. D.

    1997-05-01

    The problems of torsion, axial loading and shear of a solid cone were solved around the turn of the century by Michell and Föppl. Surprisingly, no solution to the problem of the elastic response of a cone to the only other possible resultant applied to its apex seems to have been published until now. The method used here is based on certain theoretical considerations related to the author's work on generalizing the engineering theory of beams. This means that the result is derived rather than being the result of a trial-and-error process. A comparison is made with the usual engineering theory as modified for variable bending stiffness. The two analyses give the same results at the limit as the cone angle tends to zero.

  14. Light bending in f(T) gravity

    NASA Astrophysics Data System (ADS)

    Ruggiero, Matteo Luca

    2016-05-01

    In the framework of f(T) gravity, we focus on a weak-field and spherically symmetric solution for the Lagrangian f(T) = T + αT2, where α is a small constant which parametrizes the departure from general relativity (GR). In particular, we study the propagation of light and obtain the correction to the general relativistic bending angle. Moreover, we discuss the impact of this correction on some gravitational lensing observables, and evaluate the possibility of constraining the theory parameter α by means of observations. In particular, on taking into account the astrometric accuracy in the Solar System, we obtain that |α|≤ 1.85 × 105m2; this bound is looser than those deriving from the analysis of Solar System dynamics, e.g. |α|≤ 5 × 10‑1m2 [L. Iorio, N. Radicella and M. L. Ruggiero, J. Cosmol. Astropart. Phys. 1508 (2015) 021, arXiv:1505.06996 [gr-qc].], |α|≤ 1.8 × 104m2 [L. Iorio and E. N. Saridakis, Mon. Not. R. Astron. Soc. 427 (2012) 1555, arXiv:1203.5781 [gr-qc].] or |α|≤ 1.2 × 102m2 [Y. Xie and X. M. Deng, Mon. Not. R. Astron. Soc. 433 (2013) 3584, arXiv:1312.4103 [gr-qc].]. However, we suggest that, since the effect only depends on the impact parameter, better constraints could be obtained by studying light bending from planetary objects.

  15. The Space Station program

    NASA Technical Reports Server (NTRS)

    Hinners, N. W.

    1986-01-01

    Cost constraints to a large degree control the functionality and form of the IOC of the Space Station. Planning of Station missions must be delayed to retain flexibility, a goal also served by modular development of the Station and by multi-use laboratory modules. Early emphasis on servicing other spacecraft is recommended, as is using available Shuttle flight time for R&D on Space Station technologies and operations.

  16. Powder River: data for cross-channel profiles at 22 sites in southeastern Montana from 1975 through 2012

    USGS Publications Warehouse

    Moody, John A.; Meade, Robert H.

    2013-01-01

    Powder River rises in the Bighorn Mountains of Wyoming and flows northward through a semi-arid landscape in Wyoming and Montana to the Yellowstone River. The river drains an area of 34,700 km2 and has an average discharge of about 500 million m3 y-1 or 16 m3 s-1. This view of the river looking northward, and hence downstream, was taken in October 2012 (see study reach map), about 20 km north of the Wyoming-Montana state line, about 4 km downstream from an operating gaging station at Moorhead, Montana (USGS station number 06324500), and about 80 river km upstream from a discontinued gaging station at Broadus, Montana (USGS station number 06324710). The river is emerging from a narrowly-confined reach, and the valley widens northward, bordered by hills of the coal-bearing Fort Union Formation. The river in this photo is at about bed-full flow (12 m3 s-1, Moody and others, 1999), and several riffles with disturbed water can be seen downstream between smooth glassy reaches of the river. A narrow band (~2-4 m wide) of reddish sedge (Scirpus spp.) grows just above the bed-full level along the edge of water with a wider band of mixed grasses (Agropyron repens, A. pauciflorum, Bromus inermis, Elymus canadenis, Spartina pectinata, and S. cynosoroids), willow (Salix exigua), tamarisk (Tamirix ramosissima) and small cottonwood seedlings and trees (Populus sargentii) on the flood plain. Three terrace levels have been identified along the river (Leopold and Miller, 1954; Moody and Meade, 2008). The first is the Lightning terrace with small cottonwood trees (seen here without leaves) adjacent to the floodplain in the right-center of the photo. The second is the Moorcroft terrace seen best forming the left bank and extending as a flat surface to the left (west) with a few large cottonwood trees still retaining their green leaves. The third is the colluvial Kaycee terrace that grades slowly upwards and meets the hills of the Fort Union Formation. It can be seen on the right side

  17. Canadian Space Station program

    NASA Technical Reports Server (NTRS)

    Doetsch, K. H.

    1991-01-01

    Information on the Canadian Space Station Program is given in viewgraph form. Topics covered include the Mobile Servicing Center (MSC), Space Station Freedom assembly milestones, the MB-3 launch configuration, a new workstation configuration, strategic technology development, the User Development Program, the Space Station Program budget, and Canada's future space activities.

  18. Metamaterial-waveguide bends with effective bend radius < λ₀/2.

    PubMed

    Shen, Bing; Polson, Randy; Menon, Rajesh

    2015-12-15

    We designed, fabricated, and characterized broadband, efficient, all-dielectric metamaterial-waveguide bends (MWBs) that redirect light by 180 deg. The footprint of each MWB is 3  μm×3  μm and redirection is achieved for single-mode waveguides spaced by 1.3 μm, which corresponds to an effective bend radius of 0.65 μm (<λ₀/2 for λ₀=1.55  μm). The designed and measured transmission efficiencies are >80% and ∼70%, respectively. Furthermore, the MWBs have an operating bandwidth >66 nm (design) and >56  nm (experiments). Our design methodology that incorporates fabrication constraints enables highly robust devices. The methodology can be extended to the general routing of light in tight spaces for large-scale photonic integration. PMID:26670503

  19. Stage measurement at gaging stations

    USGS Publications Warehouse

    Sauer, Vernon B.; Turnipseed, D. Phil

    2010-01-01

    Stream and reservoir stage are critical parameters in the computation of stream discharge and reservoir volume, respectively. In addition, a record of stream stage is useful in the design of structures that may be affected by stream elevation, as well as for the planning for various uses of flood plains. This report describes equipment and methodology for the observation, sensing, and recording of stage in streams and reservoirs. Although the U.S. Geological Survey (USGS) still uses the traditional, basic stilling-well float system as a predominant gaging station, modern electronic stage sensors and water-level recorders are now commonly used. Bubble gages coupled with nonsubmersible pressure transducers eliminate the need for stilling wells. Submersible pressure transducers have become common in use for the measurement of stage in both rivers and lakes. Furthermore, noncontact methods, such as radar, acoustic, and laser methods of sensing water levels, are being developed and tested, and in the case of radar, are commonly used for the measurement of stage. This report describes commonly used gaging-station structures, as well as the design and operation of gaging stations. Almost all of the equipment and instruments described in this report will meet the accuracy standard set by the USGS Office of Surface Water (OSW) for the measurement of stage for most applications, which is ?0.01 foot (ft) or 0.2 percent of the effective stage. Several telemetry systems are used to transmit stage data from the gaging station to the office, although satellite telemetry has become the standard. These telemetry systems provide near real-time stage data, as well as other information that alerts the hydrographer to extreme or abnormal events, and instrument malfunctions.

  20. Space Station Live: Station Communications Upgrade

    NASA Video Gallery

    NASA Public Affairs Officer Nicole Cloutier-Lemasters recently spoke with Penny Roberts, one of the leads for the International Space Station Avionics and Software group, about the upgrade of the K...

  1. 36 CFR 7.41 - Big Bend National Park.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Big Bend National Park. 7.41 Section 7.41 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.41 Big Bend National Park. (a) Fishing; closed...

  2. COASTAL BEND BAYS & ESTUARIES PROGRAM IMPLEMENTATION REVIEW 2004

    EPA Science Inventory

    The Coastal Bend Bays & Estuaries Program, Inc. (CBBEP) is a nonprofit 501(c)(3)organization. The CBBEP project area encompasses 12 counties coincident with the Coastal Bend Council of Governments and extends from the Land-Cut in the Laguna Madre, through the Corpus Christi Bay s...

  3. Regulation of transcription by synthetic DNA-bending agents.

    PubMed

    Bednarski, David; Firestine, Steven M

    2006-11-01

    Gene expression is regulated by a complex interplay between binding and the three-dimensional arrangement of transcription factors with RNA polymerase and DNA. Previous studies have supported a direct role for DNA bending and conformation in gene expression, which suggests that agents that induce bends in DNA might be able to control gene expression. To test this hypothesis, we examined the effect of triple-helix-forming oligonucleotide (TFO) bending agents on the transcription of luciferase in an in vitro transcriptional/translational system. We find that transcription is regulated only by a TFO that induces a bend in the DNA. Related TFOs that do not induce bends in DNA have no effect on transcription. Reporter expression can be increased by as much as 80 % or decreased by as much as 50 % depending on the phasing of the upstream bend relative to the promoter. We interpret the results as follows: when the bend is positioned such that the upstream DNA is curved toward the RNA polymerase on the same DNA face, transcription is enhanced. When the upstream DNA is curved away, transcription is attenuated. These results support the hypothesis that DNA-bending agents might have the capability to regulate gene expression, thereby opening up a previously undervalued avenue in research on the artificial control of gene expression. PMID:17004274

  4. General plan, bending machinge, Johnson Company, Johnstown, Pa. Scale 3 ...

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

    General plan, bending machinge, Johnson Company, Johnstown, Pa. Scale 3 inches - 1 ft, March 13th 1893, drawing number 15384 (photograph of drawing of rail bending machine held at the Johnstown Corporation General Office, Johnstown, Pennsylvania) - Johnson Steel Street Rail Company, 525 Central Avenue, Johnstown, Cambria County, PA

  5. View north of tube bending shop in boilermakers department located ...

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

    View north of tube bending shop in boilermakers department located in southeast corner of the structural shop building (building 57). The computer controlled tube bender can be programmed to bend boiler tubing to nearly any required configuration - Naval Base Philadelphia-Philadelphia Naval Shipyard, Structure Shop, League Island, Philadelphia, Philadelphia County, PA

  6. Observation and Modeling of Single Wall Carbon Nanotube Bend Junctions

    NASA Technical Reports Server (NTRS)

    Han, Jie; Anantram, M. P.; Jaffe, R. L.; Kong, J.; Dai, H.; Saini, Subhash (Technical Monitor)

    1998-01-01

    Single wall carbon nanotube (SWNT) bends, with diameters from approx. 1.0 to 2.5 nm and bend angles from 18 deg. to 34 deg., are observed in catalytic decomposition of hydrocarbons at 600 - 1200 C. An algorithm using molecular dynamics simulation (MD) techniques is developed to model these structures that are considered to be SWNT junctions formed by topological defects (i.e. pentagon-heptagon pairs). The algorithm is used to predict the tube helicities and defect configurations for bend junctions using the observed tube diameters and bend angles. The number and arrangement of the defects at the junction interfaces are found to depend on the tube helicities and bend angle. The structural and energetic calculations using the Brenner potential show a number of stable junction configurations for each bend angle with the 34 deg. bends being more stable than the others. Tight binding calculations for local density of state (LDOS) and transmission coefficients are carried out to investigate electrical properties of the bend junctions.

  7. 49 CFR 195.212 - Bending of pipe.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Construction § 195.212 Bending of pipe. (a) Pipe must not have a wrinkle bend. (b) Each field...

  8. 49 CFR 195.212 - Bending of pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Construction § 195.212 Bending of pipe. (a) Pipe must not have a wrinkle bend. (b) Each field...

  9. 49 CFR 195.212 - Bending of pipe.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Construction § 195.212 Bending of pipe. (a) Pipe must not have a wrinkle bend. (b) Each field...

  10. 49 CFR 195.212 - Bending of pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Construction § 195.212 Bending of pipe. (a) Pipe must not have a wrinkle bend. (b) Each field...

  11. Actuators Help Correct For Gravitational Bending Of Antenna

    NASA Technical Reports Server (NTRS)

    Levy, Roy; Strain, Douglas M.

    1996-01-01

    Force-actuator scheme devised to help correct for decrease, caused by gravitational bending, in gain of 34-m-diameter paraboloidal microwave antenna reflector used for tracking distant spacecraft and observing celestial radio sources. Also applicable to other antennas bending significantly under own weight, with consequent degradation of performance.

  12. BENDING SHOP & OVEN. United Engineering Co., Alameda, California. Plan, ...

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

    BENDING SHOP & OVEN. United Engineering Co., Alameda, California. Plan, two elevations, sections, and details. Alben Froberg, Architect, Oakland, California. Sheet no. 1 of 1. Various scales. December 15, 1941. pencil on tracing paper - United Engineering Company Shipyard, Bending Shop & Oven, 2900 Main Street, Alameda, Alameda County, CA

  13. 33 CFR 117.511 - West Pearl River.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false West Pearl River. 117.511 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.511 West Pearl River. (a) The draw of the Norfolk Southern railroad bridge, mile 22.1 at Pearl River Station, shall open on signal if...

  14. 33 CFR 117.511 - West Pearl River.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false West Pearl River. 117.511 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.511 West Pearl River. (a) The draw of the Norfolk Southern railroad bridge, mile 22.1 at Pearl River Station, shall open on signal if...

  15. 33 CFR 117.511 - West Pearl River.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false West Pearl River. 117.511 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.511 West Pearl River. (a) The draw of the Norfolk Southern railroad bridge, mile 22.1 at Pearl River Station, shall open on signal if...

  16. 33 CFR 117.511 - West Pearl River.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false West Pearl River. 117.511 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.511 West Pearl River. (a) The draw of the Norfolk Southern railroad bridge, mile 22.1 at Pearl River Station, shall open on signal if...

  17. Towards the `hyporheic meter': prediction of hyporheic exchange from bedforms to bars and bends

    NASA Astrophysics Data System (ADS)

    Cardenas, M. B.

    2009-04-01

    The hyporheic zone is now recognized as an integral component of the river-aquifer-floodplain continuum. It hosts myriad ecosystem services and biogeochemical processes. These phenomena are typically mediated by fluid flow processes; by definition, the hyporheic zone is a fluid flow path beginning and ending at the stream-sediment interface. A holistic understanding of the hyporheic zone therefore begins with a solid hydrodynamic basis. This talk presents recent lessons learned about hyporheic zone hydrology primarily from a suite of both standard and state-of-the-art numerical simulations. Coupled simulations of turbulent open channel flow and porewater flow lead to a set of equations useful for predicting hyporheic zone flux, depth, and residence time at the bedform scale under neutral, losing and gaining river conditions. Traditional groundwater flow simulations of hyporheic flow across meander bends and bars lead to a similar set of predictive equations for flux, depth and residence time in rivers of increasing sinuosity and under neutral, gaining and losing conditions. The approach presented here could be used as a template to generate predictive equations for other hyporheic-flow inducing features, such as pool-riffle or step-pool sequences and other in-stream structures. Eventually, this would result in a matrix of predictive equations, and convolution/superposition of the appropriate equations representing a collection of hyporheic forcing mechanisms present in a given river would lead to a robust ‘hyporheic meter'.

  18. Bend stresses arising from ion-exchange diffusion in glasses

    SciTech Connect

    Babukova, M.V.; Glebov, L.B.; Nikonorov, N.V.; Petrovskii, G.T.

    1985-11-01

    This paper demonstrates experimental confirmation of the presence of gigastresses arising under ion exchange, for the purpose of providing data relating to the magnitudes of stress greater than 1 GPa in these ion-exchange layers. To determine the stresses, a bend method was used on a specimen under nonuniform load. Small values of bend were determined on an IT-70 inferometer. With larger values of bend the radius of curvature of the surface was determined by measuring the focal distance in the beam of a He-Ne laser reflected from the specimen. Bending is observed in silicate glass subjected to unilateral ion-exchange diffusion of K/sup +/. It is shown that the bending of the specimens is caused by compressive stresses arising in the diffusion layer and having a value of greater than 1.5 GPa. The changes in the refractive index (RI) in the diffusion layer are determined primarily by the photoelastic effect.

  19. Limits of stability in supported graphene nanoribbons subject to bending

    NASA Astrophysics Data System (ADS)

    Korhonen, Topi; Koskinen, Pekka

    2016-06-01

    Graphene nanoribbons are prone to in-plane bending even when supported on flat substrates. However, the amount of bending that ribbons can stably withstand remains poorly known. Here, by using molecular dynamics simulations, we study the stability limits of 0.5-1.9-nm-wide armchair and zigzag graphene nanoribbons subject to bending. We observe that the limits for maximum stable curvatures are below ˜10 deg /nm in case the bending is externally forced and the limit is caused by buckling instability. Furthermore, it turns out that the limits for maximum stable curvatures are also below ˜10 deg /nm in case the bending is not forced and the limit arises only from the corrugated potential-energy landscape due to the substrate. Both of the stability limits lower rapidly when ribbons widen. These results agree with recent experiments and can be understood by means of transparent elasticity models.

  20. Bending properties of nickel electrodes for nickel-hydrogen batteries

    NASA Astrophysics Data System (ADS)

    Lerch, Bradley

    1995-04-01

    Recent changes in manufacturing have resulted in nickel-hydrogen batteries which fail prematurely by electrical shorting. This is believed to be a result of a blistering problem in the nickel electrodes. This study investigates the bending properties of nickel electrodes in an attempt to correlate the bending properties with the propensity of the electrode to blister. Nickel electrodes from three different batches of material were tested in both the as-received and impregnated forms. Effects of specimen curvature and position within the electrode on the bending strength were studied and within-electrode and batch-to-batch variation were addressed. Two color imaging techniques were employed which allowed differentiation of phases within the electrodes. These techniques aided in distinguishing the relative amounts of nickel hydroxide surface loading on each electrode, relating surface loading to bend strength. Bend strength was found to increase with the amount of surface loading.

  1. Bending Properties of Nickel Electrodes for Nickel-Hydrogen Batteries

    NASA Technical Reports Server (NTRS)

    Lerch, Brad A.; Wilson, Richard M.; Keller, Dennis; Corner, Ralph

    1995-01-01

    Recent changes in manufacturing have resulted in nickel-hydrogen batteries that fail prematurely by electrical shorting, This failure is believed to be a result of a blistering problem in the nickel electrodes. In this study the bending properties of nickel electrodes are investigated in an attempt to correlate the bending properties of the electrode with its propensity to blister. Nickel electrodes from three different batches of material were tested in both the as-received and impregnated forms. The effects of specimen curvature and position within the electrode on the bending strength were studied, and within-electrode and batch-to-batch variations were addressed. Two color-imaging techniques were employed to differentiate between the phases within the electrodes. These techniques aided in distinguishing the relative amounts of nickel hyroxide surface loading on each electrode, thereby relating surface loading to bend strength. Bend strength was found to increase with the amount of surface loading.

  2. Ultimate bending capacity of strain hardening steel pipes

    NASA Astrophysics Data System (ADS)

    Chen, Yan-fei; Zhang, Juan; Zhang, Hong; Li, Xin; Zhou, Jing; Cao, Jing

    2016-04-01

    Based on Hencky's total strain theory of plasticity, ultimate bending capacity of steel pipes can be determined analytically assuming an elastic-linear strain hardening material, the simplified analytical solution is proposed as well. Good agreement is observed when ultimate bending capacities obtained from analytical solutions are compared with experimental results from full-size tests of steel pipes. Parametric study conducted as part of this paper indicates that the strain hardening effect has significant influence on the ultimate bending capacity of steel pipes. It is shown that pipe considering strain hardening yields higher bending capacity than that of pipe assumed as elastic-perfectly plastic material. Thus, the ignorance of strain hardening effect, as commonly assumed in current codes, may underestimate the ultimate bending capacity of steel pipes. The solutions proposed in this paper are applicable in the design of offshore/onshore steel pipes, supports of offshore platforms and other tubular structural steel members.

  3. Electronic and optical properties of carbon nanotubes under pure bending

    NASA Astrophysics Data System (ADS)

    Koskinen, Pekka

    2010-11-01

    The high aspect ratio of carbon nanotubes makes them prone to bending. To know how bending affects the tubes is therefore crucial for tube identification and for electrical component design. Very few studies, however, have investigated tubes under small bending well below the buckling limit, because of technical problems due to broken translational symmetry. In this Brief Report a cost-effective and exact modeling of singe-walled nanotubes under such small bending is enabled by revised periodic boundary conditions, combined with density-functional tight-binding. The resulting, bending-induced changes in electronic and optical properties fall in clear chirality-dependent trend families. While the correct trends require full structural relaxation, they can be understood by one general argument. To know these trends fills a fundamental gap in our understanding of the properties of carbon nanotubes.

  4. Bending properties of nickel electrodes for nickel-hydrogen batteries

    NASA Technical Reports Server (NTRS)

    Lerch, Bradley

    1995-01-01

    Recent changes in manufacturing have resulted in nickel-hydrogen batteries which fail prematurely by electrical shorting. This is believed to be a result of a blistering problem in the nickel electrodes. This study investigates the bending properties of nickel electrodes in an attempt to correlate the bending properties with the propensity of the electrode to blister. Nickel electrodes from three different batches of material were tested in both the as-received and impregnated forms. Effects of specimen curvature and position within the electrode on the bending strength were studied and within-electrode and batch-to-batch variation were addressed. Two color imaging techniques were employed which allowed differentiation of phases within the electrodes. These techniques aided in distinguishing the relative amounts of nickel hydroxide surface loading on each electrode, relating surface loading to bend strength. Bend strength was found to increase with the amount of surface loading.

  5. Mechanical properties of graphynes under shearing and bending

    NASA Astrophysics Data System (ADS)

    Yi, Lijun; Zhang, Yingyan; Feng, Xiqiao; Chang, Tienchong; Wang, Ji; Du, Jianke; Zhou, Jianxin

    2016-05-01

    Graphynes are the allotrope of graphene. In this work, extensive molecular dynamics simulations are performed on four different graphynes ( α - , β - , γ - , and 6,6,12-graphynes) to explore their mechanical properties (shear modulus, shear strength, and bending rigidity) under shearing and bending. While the shearing properties are anisotropic, the bending rigidity is almost independent of the chirality of graphynes. We also find that the shear modulus and shear fracture strength of graphynes decrease with increasing temperature. The effect of the percentage of the acetylenic linkages on the shear mechanical properties and bending rigidity is investigated. It is shown that the fracture shear strengths and bending rigidities of the four types of graphynes decrease, while the fracture shear strain increases, with increasing percentages of the acetylenic linkages. Significant wrinkling is observed in graphyne under shear strain. The influence of the temperatures and percentages of the acetylenic linkages on the ratio of amplitude-to-wavelength in the wrinkles are examined.

  6. Geologic and seismic investigations for relocation of Route 20 (Springfield Bypass) Alden Street to Chicopee River, proposed cuts, stations 783-788, and 790-796 in Ludlow, Mass.

    USGS Publications Warehouse

    May, James E.; Linehan, Rev. Daniel

    1954-01-01

    This work was done to obtain geologic and seismic data that would aid in establishing a grade for the proposed highway and, also, be of value in preparing estimates on the quantities of materials to be excavated from the cuts. Seismic work was done at two sites, namely, stations 783-788; and 790-796. The work was performed in February 19852 as part of a cooperative program of the Massachusetts Department of Public Works and the United State Geological Survey.

  7. Evaluation of canoe surveys for anurans along the Rio Grande in Big Bend National Park, Texas

    USGS Publications Warehouse

    Jung, R.E.; Bonine, K.E.; Rosenshield, M.L.; de la Reza, A.; Raimondo, S.; Droege, S.

    2002-01-01

    Surveys for amphibians along large rivers pose monitoring and sampling problems. We used canoes at night to spotlight and listen for anurans along four stretches of the Rio Grande in Big Bend National Park, Texas, in 1998 and 1999. We explored temporal and spatial variation in amphibian counts and species richness and assessed relationships between amphibian counts and environmental variables, as well as amphibian-habitat associations along the banks of the Rio Grande. We documented seven anuran species, but Rio Grande leopard frogs (Rana berlandieri) accounted for 96% of the visual counts. Chorus surveys along the river detected similar or fewer numbers of species, but orders of magnitude fewer individuals compared to visual surveys. The number of species varied on average by 37% across monthly and nightly surveys. We found similar average coefficients of variation in counts of Rio Grande leopard frogs on monthly and nightly bases (CVs = 42-44%), suggesting that canoe surveys are a fairly precise technique for counts of this species. Numbers of Rio Grande leopard frogs observed were influenced by river gage levels and air and water temperatures, suggesting that surveys should be conducted under certain environmental conditions to maximize counts and maintain consistency. We found significant differences in species richness and bullfrog (Rana catesbeiana) counts among the four river stretches. Four rare anuran species were found along certain stretches but not others, which could represent either sampling error or unmeasured environmental or habitat differences among the river stretches. We found a greater association of Rio Grande leopard frogs with mud banks compared to rock or cliff (canyon) areas and with seepwillow and open areas compared to giant reed and other vegetation types. Canoe surveys appear to be a useful survey technique for anurans along the Rio Grande and may work for other large river systems as well.

  8. Flooding along Danube River

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Heavy rains in Central and Eastern Europe over the past few weeks have led to some of the worst flooding the region has witnessed in over a century. The floods have killed more than 100 people in Germany, Russia, Austria, Hungary and the Czech Republic and have led to as much as $20 billion in damage. This false-color image of the Danube River and its tributaries was taken on August 19, 2002, by the Moderate Resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite. Budapest, the capital of Hungary, sits just south of the large bend in the river at the top of the image. Here the water reached levels not seen since 1965. Fortunately, the riverbanks are lined with 33-foot retainer walls throughout the city, so it did not face the same fate as Dresden or Prague along the Elbe River. But as one can see, the floodwaters hit many rural areas farther south. As last reported, the water was receding along the Danube. Credit: Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC.

  9. Nonlinear bending models for beams and plates

    PubMed Central

    Antipov, Y. A.

    2014-01-01

    A new nonlinear model for large deflections of a beam is proposed. It comprises the Euler–Bernoulli boundary value problem for the deflection and a nonlinear integral condition. When bending does not alter the beam length, this condition guarantees that the deflected beam has the original length and fixes the horizontal displacement of the free end. The numerical results are in good agreement with the ones provided by the elastica model. Dynamic and two-dimensional generalizations of this nonlinear one-dimensional static model are also discussed. The model problem for an inextensible rectangular Kirchhoff plate, when one side is clamped, the opposite one is subjected to a shear force, and the others are free of moments and forces, is reduced to a singular integral equation with two fixed singularities. The singularities of the unknown function are examined, and a series-form solution is derived by the collocation method in terms of the associated Jacobi polynomials. The procedure requires solving an infinite system of linear algebraic equations for the expansion coefficients subject to the inextensibility condition. PMID:25294960

  10. ZERODUR: bending strength data for etched surfaces

    NASA Astrophysics Data System (ADS)

    Hartmann, Peter; Leys, Antoine; Carré, Antoine; Kerz, Franca; Westerhoff, Thomas

    2014-07-01

    In a continuous effort since 2007 a considerable amount of new data and information has been gathered on the bending strength of the extremely low thermal expansion glass ceramic ZERODUR®. By fitting a three parameter Weibull distribution to the data it could be shown that for homogenously ground surfaces minimum breakage stresses exist lying much higher than the previously applied design limits. In order to achieve even higher allowable stress values diamond grain ground surfaces have been acid etched, a procedure widely accepted as strength increasing measure. If surfaces are etched taking off layers with thickness which are comparable to the maximum micro crack depth of the preceding grinding process they also show statistical distributions compatible with a three parameter Weibull distribution. SCHOTT has performed additional measurement series with etch solutions with variable composition testing the applicability of this distribution and the possibility to achieve further increase of the minimum breakage stress. For long term loading applications strength change with time and environmental media are important. The parameter needed for prediction calculations which is combining these influences is the stress corrosion constant. Results from the past differ significantly from each other. On the basis of new investigations better information will be provided for choosing the best value for the given application conditions.

  11. Occipital bending (Yakovlevian torque) in bipolar depression.

    PubMed

    Maller, Jerome J; Anderson, Rodney; Thomson, Richard H; Rosenfeld, Jeffrey V; Daskalakis, Zafiris J; Fitzgerald, Paul B

    2015-01-30

    Differing levels of occipital lobe asymmetry and enlarged lateral ventricles have been reported within patients with bipolar disorder (BD) compared with healthy controls, suggesting different rates of occipital bending (OB). This may exert pressure on subcortical structures, such as the hippocampus, reduced among psychiatric patients. We investigated OB prevalence in 35 patients with BD and 36 healthy controls, and ventricular and occipital volumes. Prevalence was four times higher among BD patients (12/35 [34.3%]) than in control subjects (3/36 [8.3%]), as well as larger lateral ventricular volumes (LVVs). Furthermore, we found OB to relate to left-to-right ventricular and occipital lobe volume (OLV) ratios. Those with OB also had reduced left-to-right hippocampal volume ratios. The results suggest that OB is more common among BD patients than healthy subjects, and prevalent in both BD Type I and Type II patients. We posit that anomalies in neural pruning or ventricular enlargement may precipitate OB, consequently resulting in one occipital lobe twisting around the other. Although the clinical implications of these results are unclear, the study suggests that asymmetrical ventricular volume matched with a pattern of oppositely asymmetrical occipital volume is related to OB and may be a marker of psychiatric illness. PMID:25480522

  12. Large Deformation Dynamic Bending of Composite Beams

    NASA Technical Reports Server (NTRS)

    Derian, E. J.; Hyer, M. W.

    1986-01-01

    Studies were conducted on the large deformation response of composite beams subjected to a dynamic axial load. The beams were loaded with a moderate eccentricity to promote bending. The study was primarily experimental but some finite element results were obtained. Both the deformation and the failure of the beams were of interest. The static response of the beams was also studied to determine potential differences between the static and dynamic failure. Twelve different laminate types were tested. The beams tested were 23 in. by 2 in. and generally 30 plies thick. The beams were loaded dynamically with a gravity-driven impactor traveling at 19.6 ft/sec and quasi-static tests were conducted on identical beams in a displacement controlled manner. For laminates of practical interest, the failure modes under static and dynamic loadings were identical. Failure in most of the laminate types occurred in a single event involving 40% to 50% of the plies. However, failure in laminates with 300 or 150 off-axis plies occurred in several events. All laminates exhibited bimodular elastic properties. The compressive flexural moduli in some laminates was measured to be 1/2 the tensile flexural modulus. No simple relationship could be found among the measured ultimate failure strains of the different laminate types. Using empirically determined flexural properties, a finite element analysis was reasonably accurate in predicting the static and dynamic deformation response.

  13. Bending analysis of laminated composite box beams

    SciTech Connect

    Tripathy, A.K.; Patel, H.J.; Pang, S.S. . Dept. of Mechanical Engineering)

    1994-01-01

    Box beams are widely used in weight reduction structures such as aircraft wings. The use of composite box beams further reduces the weight factor for such structures with the same deflection and stress as that of isotropic box beams. The difference in the behavior of composite box beam with different fiber orientation, number of plies, and number of stringers also provides a wide range of designing parameters to achieve the required performance for a given problem. A bending analysis has been carried out for the study of deflections and stresses for box beams of different material (isotropic and laminated composites), size, and number of stringers subjected to different kinds of loading conditions. A finite element model has been developed based on the strain energy principle, and the results are compared with an available commercial code COSMOS/M.'' Experiments using aluminum and scotchply composite laminates were conducted to verify the results. An optimal design for size and number of stiffeners for a given loading condition has been achieved. Investigations have also been carried out to find the effect of transverse shear on the span-wise normal stress.

  14. UPPER YELLOWSTONE RIVER, MONTANA: MACROINVERTEBRATE DISTRIBUTION AND WATER ANALYSIS 1973-1974

    EPA Science Inventory

    Macroinvertebrate and water chemistry samples were taken at seven stations in the Yellowstone River between August 1973 and August 1974. The stations were located between Gardiner and Laurel, Montana. Macroinvertebrate samples were collected on six, and water chemistry samples on...

  15. Remotely Sensed Optical Water Quality for Water Quality Assessment and Seagrass Protection in Florida's Big Bend Region

    NASA Astrophysics Data System (ADS)

    Carlson, P. R.; Hu, C.; Cannizarro, J.; Yarbro, L. A.; English, D. C.; Magley, W.; Charbonneau, M.; Barnes, B.

    2012-12-01

    Florida's Big Bend coastal region contains the second largest contiguous seagrass bed in the continental US. Approximately 250,000 ha of seagrass have been mapped in the region, but the total area of offshore seagrass beds might be several times greater. The Suwannee River drains a largely agricultural watershed (26,000 km2) in Georgia and Florida, and its discharge (x= 280 m3/s) affects water clarity over most of the Big Bend seagrass beds. Seagrass density, species composition and areal extent were severely affected by discharge associated with tropical cyclones in 2004 and 2005, focusing attention on this important resource and the near- and far-field impacts of the Suwannee River discharge. The Lower Suwannee River also has been identified by the Florida Department of Environmental Protection as an impaired water body due to high nitrogen and algal biomass. This project attempts to improve water quality and to protect Big Bend seagrasses by making remotely sensed optical water quality data more accessible to managers and stakeholders involved in the process of regulating nutrient loads in the Suwannee River and to provide data to assess effectiveness of management actions. To accomplish these goals, we have developed and tested new algorithms for retrieval of Kd, chlorophyll, and CDOM from Modis imagery, created a time series of optical water quality (OWQ) for the Suwannee River Estuary (SRE), and related seagrass gains and losses to annual variations in optical water quality. During two years of bimonthly ground-truth cruises, chlorophyll concentrations, Aph, Ad, and Acdom in the SRE were 0.3-38.3 mgm-3, 0.013-1.056, 0.013-0.735, and 0.042-7.24, respectively. For most locations and most cruises, CDOM was the dominant determinant of Kd. In the Modis time series, Kd488 estimates (calculated using the Quasi-Analytic Algorithm of Lee et al. 2006) covaried with Suwannee River discharge between 2002 and 2011 with an overall r2 value of 0.64. This relationship is

  16. Channel adjustments to historical disturbances along the lower Brazos and Sabine Rivers, south-central USA

    NASA Astrophysics Data System (ADS)

    Heitmuller, Franklin T.

    2014-01-01

    Historical channel adjustments are documented and discussed in context with anthropogenic disturbances along two meandering, coastal plain rivers - the lower Brazos and Sabine Rivers in the south-central United States. Hard-copy streamflow-measurement notes of the U.S. Geological Survey were utilized to render historical cross sections (1925-2007) at nine gauging stations, which were complemented with repeat photographs and flood-frequency analysis to assess trajectories of channel change and interpret causative mechanisms. Downstream- and upstream-propagating disturbances caused episodes of channel-bed incision and aggradation at different locations for distinct time periods along both rivers. Incision associated with upstream dams is detected, but channels are compensated downstream with sediment inputs from lateral channel migration and tributaries. In one case, temporary aggradation along the Brazos River at Waco was likely caused by a combination of dam construction and regional soil erosion. Channel-bed incision on the lowermost Brazos River is unrelated to dams, but is associated with instream aggregate extraction, possibly in conjunction with downstream channelization. On the Sabine River, extensive aggradation during the 1930s might be associated with logging activities (1880s-1930s), but whether the cause is pervasive regional-scale hillslope erosion or local-scale mill-site activities is indeterminate. Following passage of this sediment, the river generally recovered to pre-disturbance conditions and has exhibited stability despite a mainstem reservoir. Translation of this sediment slug is attenuated by a transition to a flood-prone, distributary-dominated system downstream of the Holocene-Pleistocene terrace onlap position. Additional findings include cross-channel hingepoints separating thalweg incision from simultaneous point-bar or bank accretion at meander bends, which indicates channel adjustment occurs along non-cohesive beds in preference to

  17. Space Station Freedom Utilization Conference

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The topics addressed in Space Station Freedom Utilization Conference are: (1) space station freedom overview and research capabilities; (2) space station freedom research plans and opportunities; (3) life sciences research on space station freedom; (4) technology research on space station freedom; (5) microgravity research and biotechnology on space station freedom; and (6) closing plenary.

  18. Condition and residual life assessment of seamless steam pipe bends

    SciTech Connect

    Dufour, L.B.

    1995-12-01

    The majority of steam pipe bends in Dutch power plants are seamless. Reliable assessment of the condition of seamless bends after {approximately}100,000 hours of operation and beyond is a very complex and sometime frustrating procedure. Complex because external pipe forces can influence the damage and/or strain distribution in the bend. Besides, metallurgical, wall thickness and ovality variations are present anyhow, making the damage distribution in fact unknown. In accordance with a Dutch authority rule, a seamless bend is tested using a magnetic particles and investigated metallurgically with the aid of five surface replicas. Sometime more replicas are investigated and wall thickness and diameter measurements are performed as well. Occasionally, strain measurements are executed by applying capacitive strain gauges and the speckle correlation technique. In rare cases samples are taken from the first bend near the boiler outlet in order to perform isostress creep tests, allowing the determination of the condition and the residual life of other bends in the pipe systems. Based on years of experience the authors have learned that there is no single method or technique capable of assessing the condition and residual life of seamless steam pipe bends. Some experiences will be highlighted, together with recent developments in the field of quantified creep (void) damage--in order to determine inspection intervals--and the field of the speckle correlation technique.

  19. Atmospheric Refractive Electromagnetic Wave Bending and Propagation Delay

    NASA Astrophysics Data System (ADS)

    Mangum, Jeffrey G.; Wallace, Patrick

    2015-01-01

    In this tutorial we summarize the physics and mathematics behind refractive electromagnetic wave bending and delay. Refractive bending and delay through the Earth's atmosphere at both radio/millimetric and optical/IR wavelengths are discussed, but with most emphasis on the former, and with Atacama Large Millimeter Array (ALMA) applications in mind. As modern astronomical measurements often require subarcsecond position accuracy, care is required when selecting refractive bending and delay algorithms. For the spherically-uniform model atmospheres generally used for all refractive bending and delay algorithms, positional accuracies lsim1'' are achievable when observing at zenith angles lsim75°. A number of computationally economical approximate methods for atmospheric refractive bending and delay calculation are presented, appropriate for astronomical observations under these conditions. For observations under more realistic atmospheric conditions, for zenith angles lsim75°, or when higher positional accuracy is required, more rigorous refractive bending and delay algorithms must be employed. For accurate calculation of the refractive bending, we recommend the Auer and Standish method, using numerical integration to ray-trace through a two-layer model atmosphere, with an atmospheric model determination of the atmospheric refractivity. For the delay calculation we recommend numerical integration through a model atmosphere.

  20. Space station power system

    NASA Technical Reports Server (NTRS)

    Baraona, Cosmo R.

    1987-01-01

    The major requirements and guidelines that affect the space station configuration and power system are explained. The evolution of the space station power system from the NASA program development-feasibility phase through the current preliminary design phase is described. Several early station concepts are described and linked to the present concept. Trade study selections of photovoltaic system technologies are described in detail. A summary of present solar dynamic and power management and distribution systems is also given.

  1. 20. Station Unwatering Pumps and Sump Pump, view to the ...

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

    20. Station Unwatering Pumps and Sump Pump, view to the north. The station unwatering pumps are the two large units in the center and right foreground of photograph and are marked with the numbers 1 and 2. The sump pump is the smaller unit in left foreground of photograph. These pumps are used for unwatering the draft chests for maintenance. Note the draft tube unwatering valve visible in background between the two unwatering pumps. - Washington Water Power Clark Fork River Noxon Rapids Hydroelectric Development, Powerhouse, South bank of Clark Fork River at Noxon Rapids, Noxon, Sanders County, MT

  2. Station Crew Celebrates Christmas

    NASA Video Gallery

    Aboard the orbiting International Space Station, Expedition 34 Commander Kevin Ford, Russian Flight Engineers Oleg Novitskiy, Evgeny Tarelkin and Roman Romanenko, NASA Flight Engineer Tom Marshburn...

  3. Space Station fluid resupply

    NASA Technical Reports Server (NTRS)

    Winters, AL

    1990-01-01

    Viewgraphs on space station fluid resupply are presented. Space Station Freedom is resupplied with supercritical O2 and N2 for the ECLSS and USL on a 180 day resupply cycle. Resupply fluids are stored in the subcarriers on station between resupply cycles and transferred to the users as required. ECLSS contingency fluids (O2 and N2) are supplied and stored on station in a gaseous state. Efficiency and flexibility are major design considerations. Subcarrier approach allows multiple manifest combinations. Growth is achieved by adding modular subcarriers.

  4. Space Station operations

    NASA Technical Reports Server (NTRS)

    Gray, R. H.

    1985-01-01

    An evaluation of the success of the Space Station will be based on the service provided to the customers by the Station crew, the productivity of the crew, and the costs of operation. Attention is given to details regarding Space Station operations, a summary of operational philosophies and requirements, logistics and resupply operations, prelaunch processing and launch operations, on-orbit operations, aspects of maintainability and maintenance, habitability, and questions of medical care. A logistics module concept is considered along with a logistics module processing timeline, a habitability module concept, and a Space Station rescue mission.

  5. Flood discharges in the upper Mississippi River basin, 1993

    USGS Publications Warehouse

    Parrett, Charles; Melcher, Nick B.; James, Robert W., Jr.

    1993-01-01

    Flood-peak discharges that equaled or exceeded the 10-year recurrence interval were recorded at 154 streamflow-gaging stations in the upper Mississippi River Basin. At 41 streamflowgaging stations, the peak discharge was greater than the previous maximumknown discharge. At 15 additional gaging stations, peak discharges exceeded the previous maximum regulated peak discharge. At 45 gaging stations, peak discharges exceeded 100-year recurrence intervals.

  6. Bending Electrostriction in Polyurethanes Containing Ions as Contaminants or Additives

    NASA Astrophysics Data System (ADS)

    Watanabe, Masashi; Kato, Takahiro; Suzuki, Makoto; Amaike, Yoichi; Hirai, Toshihiro

    1999-08-01

    We demonstrated that the bending electrostriction in polyurethane films is controlled by the ions contained as contaminants or additives. The sample film used in this investigation was composed of a segmented polyester-polyurethane and was coated with a thin gold electrode on each surface by ion-sputtering. Although the application of an electric field (2 MV/m) can caused bending deformation of the film, removal of the ionic contaminants from the polyurethane by electrodialysis reduced the degree of deformation. On the other hand, the addition of a small amount of lithium bromide changed the bending direction.

  7. Integration of high power lasers in bending tools

    NASA Astrophysics Data System (ADS)

    Bammer, F.; Holzinger, B.; Humenberger, G.; Schuöcker, D.; Schumi, T.

    The integration of high power lasers into bending tools creates a possibility to bend brittle materials with conventional presses. A diode laser, which is based on 200W-laser-bars and a solid state laser with 3 kW are used in this work. By heating the material within a narrow zone the ductility is increased and the forming process can be enabled. The assembly of the heat source within the bending tools is a prerequisite in order to feed energy into the workpiece before, during and after the forming process. As a result the heating and forming process can be optimized regarding any material.

  8. Damage Analysis of Rectangular Section Composite Beam under Pure Bending

    NASA Astrophysics Data System (ADS)

    Liu, Yiping; Xiao, Fan; Liu, Zejia; Tang, Liqun; Fang, Daining

    2013-02-01

    Laminated composite beams are commonly used in engineering applications involving macro to nano structures. Based on the assumption that plain sections remain plain after deformation, this paper analyzes stress distributions in cross-ply laminated composite beams with rectangular cross-sections, and formulates the basic damage equations through Kachanov's damage definition and Janson's failure criterion. The location of the neutral axis and the ultimate bending moment are obtained for pure bending cases. The effect of the elastic modulus of the two layers on the damage evolution is analyzed; a reasonable damage composite beam model is proposed to predict the ultimate bending moment.

  9. Coupled composite rotor blades under bending and torsional loads

    NASA Astrophysics Data System (ADS)

    Chandra, Ramesh; Chopra, Inderjit

    This paper presents an analytical-cum-experimental study of the structural response of composite rotor blades with elastic couplings. Vlasov theory is expanded to analyze two-cell composite rotor blades made out of general composite laminates including the transverse shear deformation of the cross-section. In order to validate this analysis, two-cell graphite-epoxy composite blades with bending-torsion coupling were fabricated using matched-die molding technique. These blades were tested under tip bending and torsional loads, and their structural response in terms of bending slope and twist was measured with a laser optical system. Good correlation between theory and experiment is achieved.

  10. Propagating director bend fluctuations in nematic liquid crystals.

    PubMed

    Humpert, Anja; Allen, Michael P

    2015-01-16

    We show, by molecular simulation, that for a range of standard, coarse-grained, nematic liquid crystal models, the director bend fluctuation is a propagating mode. This is in contrast to the generally accepted picture of nematic hydrodynamics, in which all the director modes (splay, twist, bend, and combinations thereof) are overdamped. By considering the various physical parameters that enter the equations of nematodynamics, we propose an explanation of this effect and conclude that propagating bend fluctuations may be observable in some experimental systems. PMID:25635566

  11. 24. Station Oil Tanks, view to the south. The four ...

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

    24. Station Oil Tanks, view to the south. The four oil storage tanks located along the east wall (left side of photograph) are, from foreground to background: dirty transformer oil tank, clean transformer oil tank, dirty lubricating oil tank, and clean lubricating oil tank. An oil filter system is also visible in background along the far wall. - Washington Water Power Clark Fork River Noxon Rapids Hydroelectric Development, Powerhouse, South bank of Clark Fork River at Noxon Rapids, Noxon, Sanders County, MT

  12. 18. Station Service Control and Motor Control Center #2, view ...

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

    18. Station Service Control and Motor Control Center #2, view to the northeast. Note the circuit breaker switch on cart in left corner of photograph. This switch is part of the motor control center which has been temporarily removed from the slot marked with a tag that is visible at lower left end of control center. - Washington Water Power Clark Fork River Noxon Rapids Hydroelectric Development, Powerhouse, South bank of Clark Fork River at Noxon Rapids, Noxon, Sanders County, MT

  13. 10. Station Air Compressors, view to the north. The compressors, ...

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

    10. Station Air Compressors, view to the north. The compressors, visible in the center of the photograph, are linked to the large accumulator tanks visible in the right background of the photograph. Note that part of the compressor in the center foreground of the photograph is disassembled for maintenance. - Washington Water Power Clark Fork River Cabinet Gorge Hydroelectric Development, Powerhouse, North Bank of Clark Fork River at Cabinet Gorge, Cabinet, Bonner County, ID

  14. 17. Station Power Center 1 and Load Center 1, view ...

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

    17. Station Power Center 1 and Load Center 1, view to the northwest. The power center is the cabinet on the right and the load center is the cabinet on the left of the photograph. A door to the generator barrel of Unit 1 is visible in the background. - Washington Water Power Clark Fork River Cabinet Gorge Hydroelectric Development, Powerhouse, North Bank of Clark Fork River at Cabinet Gorge, Cabinet, Bonner County, ID

  15. Optimum design of ninety degree bends

    NASA Technical Reports Server (NTRS)

    Modi, Vijay; Cabuk, Hayri; Huan, Jian-Chun; Quadracci, Richard

    1992-01-01

    An algorithm for the optimum design of an internal flow component to obtain the maximum pressure rise is presented. Maximum pressure rise in a duct with simultaneous turning and diffusion is shown to be related to the control of flow separation on the passage walls. Such a flow is usually associated with downstream conditions that are desirable in turbomachinery and propulsion applications to ensure low loss and stable performance. The algorithm requires the solution of an 'adjoint' problem in addition to the 'direct' equations governing the flow in a body, which in the present analysis are assumed to be the laminar Navier-Stokes equations. The theoretical framework and computational algorithms presented in this study are for the steady Navier-Stokes equations. A procedure is developed for the numerical solution of the adjoint equations. This procedure is coupled with a direct solver in a design iteration loop, that provides a new shape with a higher pressure rise. This procedure is first validated for the design of optimum plane diffusers in two-dimensional flow. The direct Navier-Stokes and the 'adjoint' equations are solved using a finite volume formulation for spatial discretization in an artificial compressibility framework. A simplified version of the above approach is then utilized to design ninety degree diffusing bends. Calculations were carried out for a mean radius ratio at inlet of 2.5 and Reynolds numbers varying from 100 to 500. While at this stage laminar flows is assumed, it is shown that a similar approach can be conceived for turbulent flows.

  16. Amazon River

    Atmospheric Science Data Center

    2013-04-17

    article title:  Mouth of the Amazon River     View Larger Image ... over 6450 kilometers eastward across Brazil, the Amazon River originates in the Peruvian Andes as tiny mountain streams that eventually ...

  17. Space station executive summary

    NASA Technical Reports Server (NTRS)

    1972-01-01

    An executive summary of the modular space station study is presented. The subjects discussed are: (1) design characteristics, (2) experiment program, (3) operations, (4) program description, and (5) research implications. The modular space station is considered a candidate payload for the low cost shuttle transportation system.

  18. "Inventive" Learning Stations

    ERIC Educational Resources Information Center

    Jarrett, Olga

    2010-01-01

    Learning stations can be used for myriad purposes--to teach concepts, integrate subject matter, build interest, and allow for inquiry--the possibilities are limited only by the imagination of the teacher and the supplies available. In this article, the author shares suggestions and a checklist for setting up successful learning stations. In…

  19. Space station dynamics

    NASA Technical Reports Server (NTRS)

    Berka, Reg

    1990-01-01

    Structural dynamic characteristics and responses of the Space Station due to the natural and induced environment are discussed. Problems that are peculiar to the Space Station are also discussed. These factors lead to an overall acceleration environment that users may expect. This acceleration environment can be considered as a loading, as well as a disturbance environment.

  20. The Station System

    ERIC Educational Resources Information Center

    Brooks, David W.

    1970-01-01

    Describes an introductory college chemistry course utilizing laboratory stations and laboratory instruction by video taped presentations. Author discusses the general operation of the laboratory, the method used in evaluating students' progress, the teaching effectiveness and economy of the station system. Results of a student questionnaire reveal…

  1. Turbulent flow computation in a circular U-Bend

    NASA Astrophysics Data System (ADS)

    Miloud, Abdelkrim; Aounallah, Mohammed; Belkadi, Mustapha; Adjlout, Lahouari; Imine, Omar; Imine, Bachir

    2014-03-01

    Turbulent flows through a circular 180° curved bend with a curvature ratio of 3.375, defined as the the bend mean radius to pipe diameter is investigated numerically for a Reynolds number of 4.45×104. The computation is performed for a U-Bend with full long pipes at the entrance and at the exit. The commercial ANSYS FLUENT is used to solve the steady Reynolds-Averaged Navier-Stokes (RANS) equations. The performances of standard k-ɛ and the second moment closure RSM models are evaluated by comparing their numerical results against experimental data and testing their capabilities to capture the formation and extend this turbulence driven vortex. It is found that the secondary flows occur in the cross-stream half-plane of such configurations and primarily induced by high anisotropy of the cross-stream turbulent normal stresses near the outer bend.

  2. DESIGN MANUAL: SWIRL AND HELICAL BEND POLLUTION CONTROL DEVICES

    EPA Science Inventory

    This design manual contains descriptions of design procedures and operating experience to date, including results obtained, for secondary flow pollution control devices. Two types of combined sewer overflow regulators are described: the swirl and the helical bend regulator/separa...

  3. Technique cuts time and cost of bending jacketed piping

    NASA Technical Reports Server (NTRS)

    Gardner, J. N.

    1967-01-01

    Technique uses a stiff medium in the annular space between inner and outer pipes of jacketed piping in transfer lines. The process eliminates splitting and welding and makes possible the use of standard pipe-bending tools.

  4. Thickness-dependent bending modulus of hexagonal boron nitride nanosheets

    NASA Astrophysics Data System (ADS)

    Li, Chun; Bando, Yoshio; Zhi, Chunyi; Huang, Yang; Golberg, Dmitri

    2009-09-01

    Bending modulus of exfoliation-made single-crystalline hexagonal boron nitride nanosheets (BNNSs) with thicknesses of 25-300 nm and sizes of 1.2-3.0 µm were measured using three-point bending tests in an atomic force microscope. BNNSs suspended on an SiO2 trench were clamped by a metal film via microfabrication based on electron beam lithography. Calculated by the plate theory of a doubly clamped plate under a concentrated load, the bending modulus of BNNSs was found to increase with the decrease of sheet thickness and approach the theoretical C33 value of a hexagonal BN single crystal in thinner sheets (thickness<50 nm). The thickness-dependent bending modulus was suggested to be due to the layer distribution of stacking faults which were also thought to be responsible for the layer-by-layer BNNS exfoliation.

  5. Active vibration control of structures undergoing bending vibrations

    NASA Technical Reports Server (NTRS)

    Pla, Frederic G. (Inventor); Rajiyah, Harindra (Inventor)

    1995-01-01

    An active vibration control subassembly for a structure (such as a jet engine duct or a washing machine panel) undergoing bending vibrations caused by a source (such as the clothes agitator of the washing machine) independent of the subassembly. A piezoceramic actuator plate is vibratable by an applied electric AC signal. The plate is connected to the structure such that vibrations in the plate induced by the AC signal cause canceling bending vibrations in the structure and such that the plate is compressively pre-stressed along the structure when the structure is free of any bending vibrations. The compressive prestressing increases the amplitude of the canceling bending vibrations before the critical tensile stress level of the plate is reached. Preferably, a positive electric DC bias is also applied to the plate in its poling direction.

  6. VIEW OF NORTHWEST BEND IN BIRCH CIRCLE. VIEW FACING WEST ...

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

    VIEW OF NORTHWEST BEND IN BIRCH CIRCLE. VIEW FACING WEST - 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

  7. POU proteins bend DNA via the POU-specific domain.

    PubMed Central

    Verrijzer, C P; van Oosterhout, J A; van Weperen, W W; van der Vliet, P C

    1991-01-01

    POU proteins constitute a family of ubiquitous as well as cell type-specific transcription factors that share the conserved POU DNA binding domain. This domain consists of two distinct subdomains, a POU-specific domain and a POU homeodomain, that are both required for high affinity sequence-specific DNA binding. In a circular permutation assay, several POU proteins, including Oct-1, Oct-2A, Oct-6 and Pit-1, demonstrated a position dependent mobility of the protein-DNA complexes, suggesting induction of DNA bending. This was confirmed by detection of relative bend direction, using pre-bent DNA, and by enhanced ligase mediated cyclization. Bending was caused by interaction with the POU domain. By contrast, binding of the POU homeodomain did not distort the DNA structure, indicating that the POU-specific domain confers DNA bending. Images PMID:1915275

  8. Bending Properties of Nickel Electrodes for Nickel-Hydrogen Batteries

    NASA Technical Reports Server (NTRS)

    Lerch, Brad A.; Wilson, Richard M.; Keller, Dennis; Corner, Ralph

    1996-01-01

    Recent changes in manufacturing have resulted in nickel-hydrogen batteries that fail prematurely by electrical shorting. This failure is believed to be a result of a blistering problem in the nickel electrodes. In this study, the bending properties of nickel electrodes are investigated in an attempt to correlate the bending properties of the electrode with its propensity to blister. Nickel electrodes from three different batches of material were tested in both the as-received and impregnated forms. The effects of specimen curvature and position within the electrode on the bending strength were studied, and within-electrode and batch-to-batch variations were addressed. Bend strength was found to increase with the amount of surface loading.

  9. 9. NORTH SIDE, FROM A BOAT. THE TWO BENDING SHOP ...

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

    9. NORTH SIDE, FROM A BOAT. THE TWO BENDING SHOP AND OVEN BUILDINGS ARE VISIBLE AT THE RIGHT. - United Engineering Company Shipyard, Engineering Building, 2900 Main Street, Alameda, Alameda County, CA

  10. Tsunami Impacts in River Environments

    NASA Astrophysics Data System (ADS)

    Tolkova, E.; Tanaka, H.; Roh, M.

    2014-12-01

    The 2010 Chilean and the 2011 Tohoku tsunami events demonstrated the tsunami's ability to penetrate much farther along rivers than the ground inundation. At the same time, while tsunami impacts to the coastal areas have been subject to countless studies, little is known about tsunami propagation in rivers. Here we examine the field data and conduct numerical simulations to gain better understanding of the tsunami impacts in rivers.The evidence which motivated our study is comprised of water level measurements of the aforementioned tsunamis in multiple rivers in Japan, and the 2011 Tohoku and some other tsunamis in the Columbia River in the US. When the available tsunami observations in these very different rivers are brought together, they display remarkably similar patterns not observed on the open coast. Two phenomena were discovered in the field data. First, the phase of the river tide determines the tsunami penetration distance in a very specific way common to all rivers. Tsunami wave progressively disappears on receding tide, whereas high tide greatly facilitates the tsunami intrusion, as seen in the Figure. Second, a strong near-field tsunami causes substantial and prolonged water accumulation in lower river reaches. As the 2011 tsunami intruded rivers in Japan, the water level along rivers rose 1-2 m and stayed high for many hours, with the maximum rise occurring several km from the river mouth. The rise in the water level at some upstream gaging stations even exceeded the tsunami amplitude there.Using the numerical experiments, we attempt to identify the physics behind these effects. We will demonstrate that the nonlinear interactions among the flow components (tsunami, tide, and riverine flow) are an essential condition governing wave dynamics in tidal rivers. Understanding these interactions might explain some previous surprising observations of waves in river environments. Figure: Measurements of the 2010/02/27 tsunami along Naruse and Yoshida rivers

  11. Targeting space station technologies

    NASA Technical Reports Server (NTRS)

    Olstad, W. B.

    1983-01-01

    NASA's Space Station Technology Steering Committee has undertaken the definition of the level of technology that is desirable for use in the initial design and operation of an evolutionary, long service life space station, as well as the longer term technology required for the improvement of capabilities. The technology should initially become available in 1986, in order to support a space station launch as early as 1990. Toward this end, the committee seeks to assess technology forecasts based on existing research and testing capacity, and then plan and monitor a program which will move current technology to the requisite level of sophistication and reliability. The Space Shuttle is assumed to be the vehicle for space station delivery, assembly, and support on a 90-day initial cycle. Space station tasks will be military, commercial, and scientific, including on-orbit satellite servicing.

  12. Nile River

    Atmospheric Science Data Center

    2013-04-15

    article title:  Nile River Fluctuations Near Khartoum, Sudan     ... history, the rising and falling waters of the mighty Nile River have directly impacted the lives of the people who live along its banks. ... the area around Sudan's capital city of Khartoum capture the river's dynamic nature. Acquired by the Multi-angle Imaging SpectroRadiometer ...

  13. Mississippi River

    Atmospheric Science Data Center

    2014-05-15

    article title:  Mississippi River Flooding during Spring 2001     ... South TIFF: 1024 x 724 The Mississippi River, from its source at Lake Itasca Minnesota to the Gulf of Mexico is ... 2348 miles long. Over the course of it's history, the mighty river has flooded many times. The largest flood recorded in the lower valley ...

  14. Niger River

    Atmospheric Science Data Center

    2013-04-15

    article title:  Niger River after the Rainy Season     View larger image The third largest river in Africa, the Niger, forms an inland delta in central Mali. This ... is situated near the top of the image, where the Niger River changes direction to flow more directly eastward. Six hundred years ago, ...

  15. Theory of bending waves with applications to disk galaxies

    SciTech Connect

    Mark, J.W.K.

    1982-01-01

    A theory of bending waves is surveyed which provides an explanation for the required amplification of the warp in the Milky Way. It also provides for self-generated warps in isolated external galaxies. The shape of observed warps and partly their existence in isolated galaxies are indicative of substantial spheroidal components. The theory also provides a plausible explanation for the bending of the inner disk (<2 kpc) of the Milky Way.

  16. Calibration of combined bending-torsion fatigue reliability data reduction

    NASA Technical Reports Server (NTRS)

    Kececioglu, D.; Mcconnell, J. B.

    1969-01-01

    The combined bending-torsion fatigue reliability research machines are described. Three such machines are presently in operation. The calibration of these machines is presented in depth. Fatigue data generated with these machines for SAE 4340 steel grooved specimens subjected to reversed bending and steady torque loading are given. The data reduction procedure is presented. Finally, some comments are made about notch sensitivity and stress concentration as applied to combined fatigue.

  17. Bending strength studies on hot-pressed silicon carbide

    NASA Technical Reports Server (NTRS)

    Kriegesmann, J.

    1984-01-01

    The 4-point bending strength of 4 grades of hot-pressed SiC was determined at different temperatures. With a transgranular mode of fracture the values for bending strength are retained up to high temperatures. For intergranular fracture the decrease of strength is governed by subcritical crack growth. The intergranular fracture is caused by a high content of silicate glassy phase at the grain boundaries of hot-pressed SiC.

  18. Stream-floodwave propagation through the Great Bend alluvial aquifer, Kansas: Field measurements and numerical simulations

    USGS Publications Warehouse

    Sophocleous, M.A.

    1991-01-01

    The hypothesis is explored that groundwater-level rises in the Great Bend Prairie aquifer of Kansas are caused not only by water percolating downward through the soil but also by pressure pulses from stream flooding that propagate in a translatory motion through numerous high hydraulic diffusivity buried channels crossing the Great Bend Prairie aquifer in an approximately west to east direction. To validate this hypothesis, two transects of wells in a north-south and east-west orientation crossing and alongside some paleochannels in the area were instrumented with water-level-recording devices; streamflow data from all area streams were obtained from available stream-gaging stations. A theoretical approach was also developed to conceptualize numerically the stream-aquifer processes. The field data and numerical simulations provided support for the hypothesis. Thus, observation wells located along the shoulders or in between the inferred paleochannels show little or no fluctuations and no correlations with streamflow, whereas wells located along paleochannels show high water-level fluctuations and good correlation with the streamflows of the stream connected to the observation site by means of the paleochannels. The stream-aquifer numerical simulation results demonstrate that the larger the hydraulic diffusivity of the aquifer, the larger the extent of pressure pulse propagation and the faster the propagation speed. The conceptual simulation results indicate that long-distance propagation of stream floodwaves (of the order of tens of kilometers) through the Great Bend aquifer is indeed feasible with plausible stream and aquifer parameters. The sensitivity analysis results indicate that the extent and speed of pulse propagation is more sensitive to variations of stream roughness (Manning's coefficient) and stream channel slope than to any aquifer parameter. ?? 1991.

  19. U.S. Geological Survey Real-Time River Data Applications

    USGS Publications Warehouse

    Morlock, Scott E.

    1998-01-01

    Real-time river data provided by the USGS originate from streamflow-gaging stations. The USGS operates and maintains a network of more than 7,000 such stations across the nation (Mason and Wieger, 1995). These gaging stations, used to produce records of stage and streamflow data, are operated in cooperation with local, state, and other federal agencies. The USGS office in Indianapolis operates a statewide network of more than 170 gaging stations. The instrumentation at USGS gaging stations monitors and records river information, primarily river stage (fig. 1). As technological advances are made, many USGS gaging stations are being retrofitted with electronic instrumentation to monitor and record river data. Electronic instrumentation facilitates transmission of real-time or near real-time river data for use by government agencies in such flood-related tasks as operating flood-control structures and ordering evacuations.

  20. Tunable characteristics of bending resonance frequency in magnetoelectric laminated composites

    NASA Astrophysics Data System (ADS)

    Chen, Lei; Li, Ping; Wen, Yu-Mei; Zhu, Yong

    2013-07-01

    As the magnetoelectric (ME) effect in piezoelectric/magnetostrictive laminated composites is mediated by mechanical deformation, the ME effect is significantly enhanced in the vicinity of resonance frequency. The bending resonance frequency (fr) of bilayered Terfenol-D/PZT (MP) laminated composites is studied, and our analysis predicts that (i) the bending resonance frequency of an MP laminated composite can be tuned by an applied dc magnetic bias (Hdc) due to the ΔE effect; (ii) the bending resonance frequency of the MP laminated composite can be controlled by incorporating FeCuNbSiB layers with different thicknesses. The experimental results show that with Hdc increasing from 0 Oe (1 Oe=79.5775 A/m) to 700 Oe, the bending resonance frequency can be shifted in a range of 32.68 kHz <= fr <= 33.96 kHz. In addition, with the thickness of the FeCuNbSiB layer increasing from 0 μm to 90 μm, the bending resonance frequency of the MP laminated composite gradually increases from 33.66 kHz to 39.18 kHz. This study offers a method of adjusting the strength of dc magnetic bias or the thicknesses of the FeCuNbSiB layer to tune the bending resonance frequency for ME composite, which plays a guiding role in the ME composite design for real applications.

  1. ACHRO: A program to help design achromatic bends

    SciTech Connect

    Rusthoi, D.

    1993-01-01

    ACHRO is a very simple 2000-line. FORTRAN code that provides help for the designer of the achromatic bend. Given a beam momentum, the program calculates the required drift lengths and dipole parameters which it will apply to any one of several different types of achromats. The types of achromats that the code helps to design include the Enge dual-270,'' the Brown 2-dipole, the Leboutet 3-dipole, and the Enge 4-dipole, as well as the periodic systems which can be designed to any order in symmetric, nonsymmetric and stair-step varieties. Given the dimensions into which a bend must fit, ACHRO will calculate the geometrical parameters in an X-Y plane for a single or multiple achromat, and for achromatic S-bend'' configurations where possible. ACHRO makes it very easy to optimize a bend with respect to drift lengths and magnet parameters by allowing the user to change parameter values and see the resulting calculation. Used in conjunction with a beam-transport code, ACHRO makes it possible for a designer to consider various types of achromatic bends in the same beamline layout in order to compare important bend characteristics such as dispersion, Isochronicity, sensitivity, geometric and chromatic aberrations, aperture requirements, space for diagnostics, etc., all of which are largely a function of the geometry and the type of achromat selected.

  2. ACHRO: A program to help design achromatic bends

    SciTech Connect

    Rusthoi, D.

    1993-03-01

    ACHRO is a very simple 2000-line. FORTRAN code that provides help for the designer of the achromatic bend. Given a beam momentum, the program calculates the required drift lengths and dipole parameters which it will apply to any one of several different types of achromats. The types of achromats that the code helps to design include the Enge dual-270,`` the Brown 2-dipole, the Leboutet 3-dipole, and the Enge 4-dipole, as well as the periodic systems which can be designed to any order in symmetric, nonsymmetric and stair-step varieties. Given the dimensions into which a bend must fit, ACHRO will calculate the geometrical parameters in an X-Y plane for a single or multiple achromat, and for achromatic ``S-bend`` configurations where possible. ACHRO makes it very easy to optimize a bend with respect to drift lengths and magnet parameters by allowing the user to change parameter values and see the resulting calculation. Used in conjunction with a beam-transport code, ACHRO makes it possible for a designer to consider various types of achromatic bends in the same beamline layout in order to compare important bend characteristics such as dispersion, Isochronicity, sensitivity, geometric and chromatic aberrations, aperture requirements, space for diagnostics, etc., all of which are largely a function of the geometry and the type of achromat selected.

  3. Bending Boundary Layers in Laminated-Composite Circular Cylindrical Shells

    NASA Technical Reports Server (NTRS)

    Nemeth, Michael P.; Smeltzer, Stanley S., III

    2000-01-01

    A study of the attenuation of bending boundary layers in balanced and unbalanced, symmetrically and unsymmetrically laminated cylindrical shells is presented for nine contemporary material systems. The analysis is based on the linear Sanders-Koiter shell equations and specializations to the Love-Kirchhoff shell equations and Donnell's equations are included. Two nondimensional parameters are identified that characterize the effects of laminate orthotropy and anisotropy on the bending boundary-layer decay length in a very general manner. A substantial number of structural design technology results are presented for a wide range of laminated-composite cylinders. For all laminates considered, the results show that the differences between results obtained with the Sanders-Koiter shell equations, the Love-Kirchhoff shell equations, and Donnell's equations are negligible. The results also show that the effect of anisotropy in the form of coupling between pure bending and twisting has a negligible effect on the size of the bending boundary-layer decay length of the balanced, symmetrically laminated cylinders considered. Moreover, the results show that coupling between the various types of shell anisotropies has a negligible effect on the calculation of the bending boundary-layer decay length in most cases. The results also show that, in some cases, neglecting the shell anisotropy results in underestimating the bending boundary-layer decay length and, in other cases, results in an overestimation.

  4. Bending Boundary Layers in Laminated-Composite Circular Cylindrical Shells

    NASA Technical Reports Server (NTRS)

    Nemeth, Michael P.; Smeltzer, Stanley S., III

    2000-01-01

    An analytical, parametric study of the attenuation of bending boundary layers or edge effects in balanced and unbalanced, symmetrically and unsymmetrically laminated thin cylindrical shells is presented for nine contemporary material systems. The analysis is based on the linear Sanders-Koiter shell equations and specializations to the Love-Kirchhoff shell equations and Donnell's equations are included. Two nondimensional parameters are identified that characterize and quantify the effects of laminate orthotropy and laminate anisotropy on the bending boundary-layer decay length in a very general and encompassing manner. A substantial number of structural design technology results are presented for a wide range of laminated-composite cylinders. For all the laminate constructions considered, the results show that the differences between results that were obtained with the Sanders-Koiter shell equations, the Love-Kirchhoff shell equations, and Donnell's equations are negligible. The results also show that the effect of anisotropy in the form of coupling between pure bending and twisting has a negligible effect on the size of the bending boundary-layer decay length of the balanced, symmetrically laminated cylinders considered. Moreover, the results show that coupling between the various types of shell anisotropies has a negligible effect on the calculation of the bending boundary-layer decay length in most cases. The results also show that in some cases neglecting the shell anisotropy results in underestimating the bending boundary-layer decay length and in other cases it results in an overestimation.

  5. Bending of Light in Modified Gravity at Large Distances

    NASA Technical Reports Server (NTRS)

    Sultana, Joseph; Kazanas, Demosthenes

    2012-01-01

    We discuss the bending of light in a recent model for gravity at large distances containing a Rindler type acceleration proposed by Grumiller. We consider the static, spherically symmetric metric with cosmological constant and Rindler-like term 2ar presented in this model, and we use the procedure by Rindler and Ishak. to obtain the bending angle of light in this metric. Earlier work on light bending in this model by Carloni, Grumiller, and Preis, using the method normally employed for asymptotically flat space-times, led to a conflicting result (caused by the Rindler-like term in the metric) of a bending angle that increases with the distance of closest approach r(sub 0) of the light ray from the centrally concentrated spherically symmetric matter distribution. However, when using the alternative approach for light bending in nonasymptotically flat space-times, we show that the linear Rindler-like term produces a small correction to the general relativistic result that is inversely proportional to r(sub 0). This will in turn affect the bounds on Rindler acceleration obtained earlier from light bending and casts doubts on the nature of the linear term 2ar in the metric

  6. Building No. 1057, Experiment Station Assistant’s Residence, view of south ...

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

    Building No. 1057, Experiment Station Assistant’s Residence, view of south elevation - Wind River Administrative Site, Building No. 1057, Chapman Road, near Lookout Mountain Road, Carson, Skamania County, WA

  7. Building No. 1057, Experiment Station Assistant’s Residence, view of west ...

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

    Building No. 1057, Experiment Station Assistant’s Residence, view of west elevation - Wind River Administrative Site, Building No. 1057, Chapman Road, near Lookout Mountain Road, Carson, Skamania County, WA

  8. Building No. 1057, Experiment Station Assistant’s Residence, view of north ...

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

    Building No. 1057, Experiment Station Assistant’s Residence, view of north elevation - Wind River Administrative Site, Building No. 1057, Chapman Road, near Lookout Mountain Road, Carson, Skamania County, WA

  9. Building No. 1057, Experiment Station Assistant’s Residence, view of east ...

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

    Building No. 1057, Experiment Station Assistant’s Residence, view of east elevation - Wind River Administrative Site, Building No. 1057, Chapman Road, near Lookout Mountain Road, Carson, Skamania County, WA

  10. Building No. 1053, Experiment Station Director’s Residence, view of west ...

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

    Building No. 1053, Experiment Station Director’s Residence, view of west elevation - Wind River Administrative Site, Building No. 1053, Chapman Avenue, near Lookout Mountain Road, Carson, Skamania County, WA

  11. Building No. 1053, Experiment Station Director’s Residence, view of east ...

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

    Building No. 1053, Experiment Station Director’s Residence, view of east elevation - Wind River Administrative Site, Building No. 1053, Chapman Avenue, near Lookout Mountain Road, Carson, Skamania County, WA

  12. Building No. 1053, Experiment Station Director’s Residence, view of south ...

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

    Building No. 1053, Experiment Station Director’s Residence, view of south elevation - Wind River Administrative Site, Building No. 1053, Chapman Avenue, near Lookout Mountain Road, Carson, Skamania County, WA

  13. Building No. 1053, Experiment Station Director’s Residence, view of north ...

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

    Building No. 1053, Experiment Station Director’s Residence, view of north elevation - Wind River Administrative Site, Building No. 1053, Chapman Avenue, near Lookout Mountain Road, Carson, Skamania County, WA

  14. Topographic steering, flow recirculation, velocity redistribution, and bed topography in sharp meander bends

    NASA Astrophysics Data System (ADS)

    Blanckaert, K.

    2010-09-01

    The bed topography and associated flow field are investigated in a laboratory configuration with parameters that are representative for sharp natural meander bends. Zones of inward mass transport are characterized by a quasi-linear transverse bed profile, whereas zones of outward mass transport, induced by pronounced curvature variations, are characterized by a quasi-horizontal shallow point bar at the inside of the bend, a deep pool at the outside, and an increase in overall cross-sectional area. These quasi-bilinear bed profiles can be attributed to the curvature-induced secondary flow that is confined to the pool. Topographic steering, mainly due to mass conservation, concentrates the major part of the discharge over the deepest zones of the bend. But the pattern of depth-averaged velocities, which is relevant with respect to the development of the bed topography, does not show maximum values over the deepest zones. A term-by-term analysis of the depth-averaged streamwise momentum equation reveals that the water surface gradient is the principal mechanism with respect to flow velocity redistribution, although inertia and secondary flow are also processes of dominant order of magnitude. A required condition for the occurrence of adverse pressure gradients and flow recirculation due to planform curvature variations is established. A different type of flow recirculation, due to a subtle feedback between the flow and the bed topography, occurs over the point bar. The neglect of the influence of vertical velocities impinging on the bed in models for sediment transport is identified as a major shortcoming in the modeling of the morphodynamics of meandering river channels.

  15. 4. EASTBOUND VIEW. NORTH TRACK WAITING STATION ON LEFT. STATION ...

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

    4. EASTBOUND VIEW. NORTH TRACK WAITING STATION ON LEFT. STATION ON RIGHT. NOTE TUNNEL IN BACKGROUND. - Baltimore & Ohio Railroad, Harpers Ferry Station, Potomac Street, Harpers Ferry, Jefferson County, WV

  16. History of suspended-sediment data collection and inventory of available data for the Tennessee and Cumberland River basins

    USGS Publications Warehouse

    Carey, William P.; Brown, Russell T.; Chatham, Carrie G.

    1988-01-01

    In 1934 and 1935, the Tennessee Valley Authority established 51 daily record suspended-sediment stations on the Tennessee River and its major tributaries. Most of these stations were operated for 8 years. From 1962 to 1965, the Tennessee Valley Authority again collected daily sediment record at 10 of the original 49 stations. In addition to the data sets collected on the major rivers, the Tennessee Valley Authority has conducted several intensive studies of small watersheds throughout the Tennessee River basin. In the Cumberland River basin, daily sediment records have been collected primarily by the Survey. Daily stations have been operated for various periods on 17 basins ranging in size from 0.67 to 1,977 sq mi, with the earliest data of daily record being October 1953. All of these daily stations are located in the upper Cumberland River basin upstream of any major impoundments. Periodic sediment data have been collected by the Survey at 194 stations in the Tennessee River basin and at 106 stations in the Cumberland River basin, however; the number of samples/station is quite low. 86% of the periodic stations in the Tennessee River basin and 91% of the periodic stations in the Cumberland River basin have 30 samples or less. (USGS)

  17. Nonlinear Curvature Expressions for Combined Flapwise Bending, Chordwise Bending, Torsion and Extension of Twisted Rotor Blades

    NASA Technical Reports Server (NTRS)

    Kvaternik, R. G.; Kaza, K. R. V.

    1976-01-01

    The nonlinear curvature expressions for a twisted rotor blade or a beam undergoing transverse bending in two planes, torsion, and extension were developed. The curvature expressions were obtained using simple geometric considerations. The expressions were first developed in a general manner using the geometrical nonlinear theory of elasticity. These general nonlinear expressions were then systematically reduced to four levels of approximation by imposing various simplifying assumptions, and in each of these levels the second degree nonlinear expressions were given. The assumptions were carefully stated and their implications with respect to the nonlinear theory of elasticity as applied to beams were pointed out. The transformation matrices between the deformed and undeformed blade-fixed coordinates, which were needed in the development of the curvature expressions, were also given for three of the levels of approximation. The present curvature expressions and transformation matrices were compared with corresponding expressions existing in the literature.

  18. Coupled bending-bending-torsion flutter of a mistuned cascade with nonuniform blades

    NASA Technical Reports Server (NTRS)

    Kaza, K. R. V.; Kielb, R. E.

    1982-01-01

    A set of aeroelastic equations describing the motion of an arbitrarily mistuned cascade with flexible, pretwisted, nonuniform blades is developed using an extended Hamilton's principle. The derivation of the equations has its basis in the geometric nonlinear theory of elasticity in which the elongations and shears are negligible compared to unity. A general expression for foreshortening of a blade is derived and is explicity used in the formulation. The blade aerodynamic loading in the subsonic and supersonic flow regimes is obtained from two dimensional, unsteady, cascade theories. The aerodynamic, inertial and structural coupling between the bending (in two planes) and torsional motions of the blade is included. The equations are used to investigate the aeroelastic stability and to quantify the effect of frequency mistuning on flutter in turbofans. Results indicate that a moderate amount of intentional mistuning has enough potential to alleviate flutter problems in unshrouded, high aspect ratio turbofans.

  19. Comparison of bed form variance spectra within a meander bend during flood and average discharge.

    USGS Publications Warehouse

    Levey, R.A.; Kjerfve, B.; Getzen, R.T.

    1980-01-01

    Time series analysis of streambed elevation in a meander bend along the Congaree River was used to determine the changes in bed form population succeeding a 16-year flood event. Variance spectra computed for a 595m longitudinal profile indicate that: a) the bed form variance for the flood record is significantly greater for all wavelengths from 5 to 30m; b) no well-demarcated bed form classes were present during the survey times, pointing to the possible existence of a continuum of bed form sizes rather than well-defined classes; and c) bed forms produced by the flood discharge were rapidly altered as the stage returned toward average level. -from Authors

  20. Space Station Induced Monitoring

    NASA Technical Reports Server (NTRS)

    Spann, James F. (Editor); Torr, Marsha R. (Editor)

    1988-01-01

    This report contains the results of a conference convened May 10-11, 1988, to review plans for monitoring the Space Station induced environment, to recommend primary components of an induced environment monitoring package, and to make recommendations pertaining to suggested modifications of the Space Station External Contamination Control Requirements Document JSC 30426. The contents of this report are divided as Follows: Monitoring Induced Environment - Space Station Work Packages Requirements, Neutral Environment, Photon Emission Environment, Particulate Environment, Surface Deposition/Contamination; and Contamination Control Requirements.

  1. Space station propulsion technology

    NASA Technical Reports Server (NTRS)

    Norman, A. M.; Briley, G. L.; Evans, S. A.

    1987-01-01

    The objectives of this program are to provide a demonstration of hydrogen/oxygen propulsion technology readiness for the initial operational capability (IOC) space station application, specifically gaseous hydrogen/oxygen and warm hydrogen thruster concepts, and to establish a means for evolving from the IOC space station propulsion system (SSPS) to that required to support and interface with advanced station functions. These objectives were met by analytical studies and by furnishing a propulsion test bed to the Marshall Space Flight Center for testing.

  2. Madrid space station

    NASA Technical Reports Server (NTRS)

    Fahnestock, R. J.; Renzetti, N. A.

    1975-01-01

    The Madrid space station, operated under bilateral agreements between the governments of the United States and Spain, is described in both Spanish and English. The space station utilizes two tracking and data acquisition networks: the Deep Space Network (DSN) of the National Aeronautics and Space Administration and the Spaceflight Tracking and Data Network (STDN) operated under the direction of the Goddard Space Flight Center. The station, which is staffed by Spanish employees, comprises four facilities: Robledo 1, Cebreros, and Fresnedillas-Navalagamella, all with 26-meter-diameter antennas, and Robledo 2, with a 64-meter antenna.

  3. The space station

    NASA Technical Reports Server (NTRS)

    Munoz, Abraham

    1988-01-01

    Conceived since the beginning of time, living in space is no longer a dream but rather a very near reality. The concept of a Space Station is not a new one, but a redefined one. Many investigations on the kinds of experiments and work assignments the Space Station will need to accommodate have been completed, but NASA specialists are constantly talking with potential users of the Station to learn more about the work they, the users, want to do in space. Present configurations are examined along with possible new ones.

  4. Methods for Quantifying Shallow-Water Habitat Availability in the Missouri River

    SciTech Connect

    Hanrahan, Timothy P.; Larson, Kyle B.

    2012-04-09

    As part of regulatory requirements for shallow-water habitat (SWH) restoration, the U.S. Army Corps of Engineers (USACE) completes periodic estimates of the quantity of SWH available throughout the lower 752 mi of the Missouri River. To date, these estimates have been made by various methods that consider only the water depth criterion for SWH. The USACE has completed estimates of SWH availability based on both depth and velocity criteria at four river bends (hereafter called reference bends), encompassing approximately 8 river miles within the lower 752 mi of the Missouri River. These estimates were made from the results of hydraulic modeling of water depth and velocity throughout each bend. Hydraulic modeling of additional river bends is not expected to be completed for deriving estimates of available SWH. Instead, future estimates of SWH will be based on the water depth criterion. The objective of this project, conducted by the Pacific Northwest National Laboratory for the USACE Omaha District, was to develop geographic information system methods for estimating the quantity of available SWH based on water depth only. Knowing that only a limited amount of water depth and channel geometry data would be available for all the remaining bends within the lower 752 mi of the Missouri River, the intent was to determine what information, if any, from the four reference bends could be used to develop methods for estimating SWH at the remaining bends. Specifically, we examined the relationship between cross-section channel morphology and relative differences between SWH estimates based on combined depth and velocity criteria and the depth-only criterion to determine if a correction factor could be applied to estimates of SWH based on the depth-only criterion. In developing these methods, we also explored the applicability of two commonly used geographic information system interpolation methods (TIN and ANUDEM) for estimating SWH using four different elevation data

  5. The statistical difference between bending arcs and regular polar arcs

    NASA Astrophysics Data System (ADS)

    Kullen, A.; Fear, R. C.; Milan, S. E.; Carter, J. A.; Karlsson, T.

    2015-12-01

    In this work, the Polar UVI data set by Kullen et al. (2002) of 74 polar arcs is reinvestigated, focusing on bending arcs. Bending arcs are typically faint and form (depending on interplanetary magnetic field (IMF) By direction) on the dawnside or duskside oval with the tip of the arc splitting off the dayside oval. The tip subsequently moves into the polar cap in the antisunward direction, while the arc's nightside end remains attached to the oval, eventually becoming hook-shaped. Our investigation shows that bending arcs appear on the opposite oval side from and farther sunward than most regular polar arcs. They form during By-dominated IMF conditions: typically, the IMF clock angle increases from 60 to 90° about 20 min before the arc forms. Antisunward plasma flows from the oval into the polar cap just poleward of bending arcs are seen in Super Dual Auroral Radar Network data, indicating dayside reconnection. For regular polar arcs, recently reported characteristics are confirmed in contrast to bending arcs. This includes plasma flows along the nightside oval that originate close to the initial arc location and a significant delay in the correlation between IMF By and initial arc location. In our data set, the highest correlations are found with IMF By appearing at least 1-2 h before arc formation. In summary, bending arcs are distinctly different from regular arcs and cannot be explained by existing polar arc models. Instead, these results are consistent with the formation mechanism described in Carter et al. (2015), suggesting that bending arcs are caused by dayside reconnection.

  6. LOCK, DOG HOUSE, CONTROL STATION, DAM GATE, MANEUVER BOAT No. ...

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

    LOCK, DOG HOUSE, CONTROL STATION, DAM GATE, MANEUVER BOAT No. 1, AND DAM. NOTE LOWER LOCK GATE IN FOREGROUND. LOOKING NORTH NORTHEAST. - Illinois Waterway, La Grange Lock and Dam, 3/4 mile south of Country 795N at Illinois River, Versailles, Brown County, IL

  7. General view of outside diameter welding stations of the saw ...

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

    General view of outside diameter welding stations of the saw line in bay 8 of the main pipe mill building looking northwest. - U.S. Steel National Tube Works, Main Pipe Mill Building, Along Monongahela River, McKeesport, Allegheny County, PA

  8. 2. Photocopied from Photo 11456, Wheelon Station Special Folder, Engineering ...

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

    2. Photocopied from Photo 11456, Wheelon Station Special Folder, Engineering Dept., Utah Power & Light Co., Salt Lake City, Utah. 'WHEELON HYDRO-ELECTRIC PLANT (7125 KW). INTERIOR OF MAIN BUILDING SHOWING FOUR 1000 KW UNITS. NOV 1914.' - Utah Sugar Company, Wheelon Hydoelectric Plant, Bear River, Fielding, Box Elder County, UT

  9. 5. Photocopied from drawing 70, Nunns Station Folder, Engineering Department, ...

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

    5. Photocopied from drawing 70, Nunns Station Folder, Engineering Department, Utah Power & Light Co., Salt Lake City, Utah. 'TILE TELLURIDE POWER TRANSMISSION CO. POWER HOUSE IN PROVO CANYON, PROVO, UTAH' SECTION, c. 1900. - Telluride Power Company, Nunn Hydroelectric Plant, Southeast side of Provo River, 300 feet West of US Route 189, Orem, Utah County, UT

  10. [Relationship between hardness, abrasion and bending strength of UV-polymerizable adhesives].

    PubMed

    Reinhardt, K J; Vahl, J

    1978-04-01

    These experiments were undertaken to explore the influence of hardening on bending and bending strength of photopolymerisable adhesives. It was shown that light sources at present in use only influence the bending strength to a small degree but enable 40% variation in bending. The use of more intensive light sources not yet in commercial use led to further improvements. PMID:274282

  11. Station Assembly Animation

    NASA Video Gallery

    This animation depicts the assembly of the International Space Station since Nov. 20, 1998, with the delivery of the Zarya module, through May 16, 2011, with the delivery of the EXPRESS Logistics C...

  12. Multiple Craft Stations.

    ERIC Educational Resources Information Center

    Johns, Mary Sue

    1980-01-01

    Described are three craft stations (claywork, papermaking, and stamp designing) for intermediate grade students, to correlate with their classroom study which focused on Ohio: its history, geography, cities, industries, products and famous natives. (KC)

  13. Space Station Live! Tour

    NASA Video Gallery

    NASA is using the Internet and smartphones to provide the public with a new inside look at what happens aboard the International Space Station and in the Mission Control Center. NASA Public Affairs...

  14. Space Station Software Issues

    NASA Technical Reports Server (NTRS)

    Voigt, S. (Editor); Beskenis, S. (Editor)

    1985-01-01

    Issues in the development of software for the Space Station are discussed. Software acquisition and management, software development environment, standards, information system support for software developers, and a future software advisory board are addressed.

  15. Space Station Food System

    NASA Technical Reports Server (NTRS)

    Thurmond, Beverly A.; Gillan, Douglas J.; Perchonok, Michele G.; Marcus, Beth A.; Bourland, Charles T.

    1986-01-01

    A team of engineers and food scientists from NASA, the aerospace industry, food companies, and academia are defining the Space Station Food System. The team identified the system requirements based on an analysis of past and current space food systems, food systems from isolated environment communities that resemble Space Station, and the projected Space Station parameters. The team is resolving conflicts among requirements through the use of trade-off analyses. The requirements will give rise to a set of specifications which, in turn, will be used to produce concepts. Concept verification will include testing of prototypes, both in 1-g and microgravity. The end-item specification provides an overall guide for assembling a functional food system for Space Station.

  16. Destination Station Atlanta

    NASA Video Gallery

    Destination Station was recently in Atlanta from April 15 through April 21. During the week, NASA visited schools, hospitals, museums, and the city’s well known Atlanta Science Tavern Meet Up gro...

  17. Space Station - early concept

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Display model of space station concept--Manned Orbiting Research Laboratory in Saturn S-IVB Orbit configuration. Published in James R. Hansen, Spaceflight Revolution: NASA Langley Research Center From Sputnik to Apollo, (Washington: NASA, 1995).

  18. Space station propulsion technology

    NASA Technical Reports Server (NTRS)

    Briley, G. L.

    1986-01-01

    The progress on the Space Station Propulsion Technology Program is described. The objectives are to provide a demonstration of hydrogen/oxygen propulsion technology readiness for the Initial Operating Capability (IOC) space station application, specifically gaseous hydrogen/oxygen and warm hydrogen thruster concepts, and to establish a means for evolving from the IOC space station propulsion to that required to support and interface with advanced station functions. The evaluation of concepts was completed. The accumulator module of the test bed was completed and, with the microprocessor controller, delivered to NASA-MSFC. An oxygen/hydrogen thruster was modified for use with the test bed and successfully tested at mixture ratios from 4:1 to 8:1.

  19. Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Keyes, Gilbert

    1991-01-01

    Information is given in viewgraph form on Space Station Freedom. Topics covered include future evolution, man-tended capability, permanently manned capability, standard payload rack dimensions, the Crystals by Vapor Transport Experiment (CVTE), commercial space projects interfaces, and pricing policy.

  20. Enabler operator station

    NASA Technical Reports Server (NTRS)

    Bailey, Andrea; Kietzman, John; King, Shirlyn; Stover, Rae; Wegner, Torsten

    1992-01-01

    The objective of this project was to design an onboard operator station for the conceptual Lunar Work Vehicle (LWV). The LWV would be used in the colonization of a lunar outpost. The details that follow, however, are for an Earth-bound model. The operator station is designed to be dimensionally correct for an astronaut wearing the current space shuttle EVA suit (which include life support). The proposed operator station will support and restrain an astronaut as well as to provide protection from the hazards of vehicle rollover. The threat of suit puncture is eliminated by rounding all corners and edges. A step-plate, located at the front of the vehicle, provides excellent ease of entry and exit. The operator station weight requirements are met by making efficient use of rigid members, semi-rigid members, and woven fabrics.

  1. Pilot's Desk Flight Station

    NASA Technical Reports Server (NTRS)

    Sexton, G. A.

    1984-01-01

    Aircraft flight station designs have generally evolved through the incorporation of improved or modernized controls and displays. In connection with a continuing increase in the amount of information displayed, this process has produced a complex and cluttered conglomeration of knobs, switches, and electromechanical displays. The result was often high crew workload, missed signals, and misinterpreted information. Advances in electronic technology have now, however, led to new concepts in flight station design. An American aerospace company in cooperation with NASA has utilized these concepts to develop a candidate conceptual design for a 1995 flight station. The obtained Pilot's Desk Flight Station is a unique design which resembles more an operator's console than today's cockpit. Attention is given to configuration, primary flight controllers, front panel displays, flight/navigation display, approach charts and weather display, head-up display, and voice command and response systems.

  2. Space station data flow

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The results of the space station data flow study are reported. Conceived is a low cost interactive data dissemination system for space station experiment data that includes facility and personnel requirements and locations, phasing requirements and implementation costs. Each of the experiments identified by the operating schedule is analyzed and the support characteristics identified in order to determine data characteristics. Qualitative and quantitative comparison of candidate concepts resulted in a proposed data system configuration baseline concept that includes a data center which combines the responsibility of reprocessing, archiving, and user services according to the various agencies and their responsibility assignments. The primary source of data is the space station complex which provides through the Tracking Data Relay Satellite System (TDRS) and by space shuttle delivery data from experiments in free flying modules and orbiting shuttles as well as from the experiments in the modular space station itself.

  3. The Space Station Chronicles

    NASA Video Gallery

    As early as the nineteenth century, writers and artists and scientists around the world began to publish their visions of a crewed outpost in space. Learn about the history of space stations, from ...

  4. Space Station Software Recommendations

    NASA Technical Reports Server (NTRS)

    Voigt, S. (Editor)

    1985-01-01

    Four panels of invited experts and NASA representatives focused on the following topics: software management, software development environment, languages, and software standards. Each panel deliberated in private, held two open sessions with audience participation, and developed recommendations for the NASA Space Station Program. The major thrusts of the recommendations were as follows: (1) The software management plan should establish policies, responsibilities, and decision points for software acquisition; (2) NASA should furnish a uniform modular software support environment and require its use for all space station software acquired (or developed); (3) The language Ada should be selected for space station software, and NASA should begin to address issues related to the effective use of Ada; and (4) The space station software standards should be selected (based upon existing standards where possible), and an organization should be identified to promulgate and enforce them. These and related recommendations are described in detail in the conference proceedings.

  5. Station Commander Praises AMS

    NASA Video Gallery

    When asked what's the most important International Space Station experiment, Commander Chris Hadfield names the Alpha Magnetic Spectrometer-2, a state-of-the-art particle physics detector that coul...

  6. Space station proposed

    NASA Astrophysics Data System (ADS)

    In his State of the Union address on January 25, President Ronald Reagan announced that he was directing the National Aeronautics and Space Administration (NASA) to “develop a permanently manned space station, and to do it within a decade.”Included in the NASA budget proposal sent to Congress the following week was $150 million for the station. This is the first request of many; expected costs will total roughly $8 billion by the early 1990's.

  7. Space Station galley design

    NASA Technical Reports Server (NTRS)

    Trabanino, Rudy; Murphy, George L.; Yakut, M. M.

    1986-01-01

    An Advanced Food Hardware System galley for the initial operating capability (IOC) Space Station is discussed. Space Station will employ food hardware items that have never been flown in space, such as a dishwasher, microwave oven, blender/mixer, bulk food and beverage dispensers, automated food inventory management, a trash compactor, and an advanced technology refrigerator/freezer. These new technologies and designs are described and the trades, design, development, and testing associated with each are summarized.

  8. Potentials of real time control, stormwater infiltration and urine separation to minimize river impacts: dynamic long term simulation of sewer network, pumping stations, pressure pipes and waste water treatment plant.

    PubMed

    Peters, C; Keller, S; Sieker, H; Jekel, M

    2007-01-01

    River Panke (Berlin, Germany) suffers from hydraulic peak loads and pollutant loads from separate sewers and combined sewer overflows (CSOs). Pumping the wastewater through long pressure pipes causes extreme peak loads to the wastewater treatment plant (WWTP) during stormwater events. In order to find a good solution, it is essential not to decide on one approach at the beginning, but to evaluate a number of different approaches. For this reason, an integrated simulation study is carried out, assessing the potentials of real time control (RTC), stormwater infiltration, storage and urine separation. Criteria for the assessment are derived and multi-criteria analysis is applied. Despite spatial limitations, infiltration has the highest potential and is very effective with respect to both overflows and the WWTP. Due to a high percentage of separate systems, urine separation has a similar potential and causes the strongest benefits at the WWTP. Unconventional control strategies can lead to significant improvement (comparable to infiltrating the water from approximately 10% of the sealed area). PMID:18048971

  9. Space station task force perspective

    NASA Technical Reports Server (NTRS)

    Hicks, C.

    1984-01-01

    Space station planning quidelines; architecture; functions; preliminary mission data base; scope for international and commercial participation; schedules; servicing capability; technology development; and space station program interfaces are discussed.

  10. Space station mobile transporter

    NASA Technical Reports Server (NTRS)

    Renshall, James; Marks, Geoff W.; Young, Grant L.

    1988-01-01

    The first quarter of the next century will see an operational space station that will provide a permanently manned base for satellite servicing, multiple strategic scientific and commercial payload deployment, and Orbital Maneuvering Vehicle/Orbital Transfer Vehicle (OMV/OTV) retrieval replenishment and deployment. The space station, as conceived, is constructed in orbit and will be maintained in orbit. The construction, servicing, maintenance and deployment tasks, when coupled with the size of the station, dictate that some form of transportation and manipulation device be conceived. The Transporter described will work in conjunction with the Orbiter and an Assembly Work Platform (AWP) to construct the Work Station. The Transporter will also work in conjunction with the Mobile Remote Servicer to service and install payloads, retrieve, service and deploy satellites, and service and maintain the station itself. The Transporter involved in station construction when mounted on the AWP and later supporting a maintenance or inspection task with the Mobile Remote Servicer and the Flight Telerobotic Servicer is shown.

  11. The Princess Elisabeth Station

    NASA Technical Reports Server (NTRS)

    Berte, Johan

    2012-01-01

    Aware of the increasing impact of human activities on the Earth system, Belgian Science Policy Office (Belspo) launched in 1997 a research programme in support of a sustainable development policy. This umbrella programme included the Belgian Scientific Programme on Antarctic Research. The International Polar Foundation, an organization led by the civil engineer and explorer Alain Hubert, was commissioned by the Belgian Federal government in 2004 to design, construct and operate a new Belgian Antarctic Research Station as an element under this umbrella programme. The station was to be designed as a central location for investigating the characteristic sequence of Antarctic geographical regions (polynia, coast, ice shelf, ice sheet, marginal mountain area and dry valleys, inland plateau) within a radius of 200 kilometers (approx.124 miles) of a selected site. The station was also to be designed as "state of the art" with respect to sustainable development, energy consumption, and waste disposal, with a minimum lifetime of 25 years. The goal of the project was to build a station and enable science. So first we needed some basic requirements, which I have listed here; plus we had to finance the station ourselves. Our most important requirement was that we decided to make it a zero emissions station. This was both a philosophical choice as we thought it more consistent with Antarctic Treaty obligations and it was also a logistical advantage. If you are using renewable energy sources, you do not have to bring in all the fuel.

  12. 2. TEN MILE RIVER CULVERT WITH DODGEVILLE MILL IN BACKGROUND. ...

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

    2. TEN MILE RIVER CULVERT WITH DODGEVILLE MILL IN BACKGROUND. DODGEVILLE, BRISTOL CO., MA. Sec. 4116, MP 195.55. - Northeast Railroad Corridor, Amtrak Route between RI/MA State Line & South Station, Boston, Suffolk County, MA

  13. WATER QUALITY REPORT, PALOUSE RIVER, WASHINGTON, 1970-1971

    EPA Science Inventory

    Accumulated water quality monitoring data indicates that Palouse River mainstem and south fork waters (17060108) suffer severe pollution problems throughout the year. South fork stations were more seriously affected. Coliform levels were generally far in excess of water quality...

  14. 8. NEW YORK HARBOR MODEL. VIEW FACING DOWN EAST RIVER ...

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

    8. NEW YORK HARBOR MODEL. VIEW FACING DOWN EAST RIVER TO NEW YORK HARBOR, WITH LOWER MANHATTAN ISLAND AT RIGHT. - Waterways Experiment Station, Hydraulics Laboratory, Halls Ferry Road, 2 miles south of I-20, Vicksburg, Warren County, MS

  15. How do spin waves pass through a bend?

    PubMed Central

    Xing, Xiangjun; Yu, Yongli; Li, Shuwei; Huang, Xiaohong

    2013-01-01

    Spin-wave devices hold great promise to be used in future information processing. Manipulation of spin-wave propagation inside the submicrometer waveguides is at the core of promoting the practical application of these devices. Just as in today's silicon-based chips, bending of the building blocks cannot be avoided in real spin-wave circuits. Here, we examine spin-wave transport in bended magnonic waveguides at the submicron scale using micromagnetic simulations. It is seen that the impact of the bend is relevant to the frequency of the passing spin wave. At the lowest frequencies, the spin wave continuously follows the waveguide in the propagation process. At the higher frequencies, however the bend acts as a mode converter for the passing spin wave, causing zigzag-like propagation path formed in the waveguide behind the bend. Additionally, we demonstrate a logic-NOT gate based on such a waveguide, which could be combined to perform logic-NAND operation. PMID:24129823

  16. Bending-induced phase transition in monolayer black phosphorus

    NASA Astrophysics Data System (ADS)

    Pan, Dou-Xing; Wang, Tzu-Chiang; Guo, Wan-Lin

    2015-08-01

    Bending-induced phase transition in monolayer black phosphorus is investigated through first principles calculations. By wrapping the layer into nanotubes along armchair and zigzag directions with different curvatures, it is found that phase transitions of the tubes occur when radius of curvature is smaller than 5 Å in bending along the zigzag direction, while the tubes remain stable along the armchair direction. Small zigzag tubes with odd numbered monolayer unit cells tend to transfer toward armchair-like phases, but the tubes with even numbered monolayer unit cells transfer into new complex bonding structures. The mechanism for the bending-induced phase transition is revealed by the comprehensive analyses of the bending strain energies, electron density distributions, and band structures. The results show significant anisotropic bending stability of black phosphorus and should be helpful for its mechanical cleavage fabrication in large size. Project supported by the National Natural Science Foundation of China (Grant Nos. 11021262, 11172303, and 11132011) and the National Basic Research Program of China (Grant No.2012CB937500).

  17. Performance evaluation of bending actuators made from electrostrictive graft elastomers

    NASA Astrophysics Data System (ADS)

    Su, Ji; Costen, Robert C.; Harrison, Joycelyn S.; Newbury, Kenneth M.; Leo, Donald J.

    2002-07-01

    Recently a new class of electrostrictive polymers, called electrostrictive graft elastomers, was developed at NASA Langley Research Center. In this work, the output force of a bending actuator made from electrostrictive graft elastomer was measured and modeled to understand the dependence of performance on device configuration. This understanding should lead to better actuator design and fabrication. The prototype bending actuator is 47micrometers thick and 8 mm wide. The output bending force at the tip was measured as a function of applied voltage and the distance from the tip to the holding stage. The output force at 2.1 kV increases from 124(mu) N at a length of 33.5 mm to 662(mu) N at 7 mm. Accourding to a small displacement, 5-layer, a strength-of- materials model, the output bending force of the actuator varies inversely with its length and directly with the square of the applied voltage. Consequently, the output bending force can be about 5 mN when the length of the actuator is reduced to 1 mm for application to micro- electromechanical (MEMS) devices. The experimental results will be presented and a method for enhancing the performance will also be discussed.

  18. Hysteresis of the resonance frequency of magnetostrictive bending cantilevers

    NASA Astrophysics Data System (ADS)

    Löffler, Michael; Kremer, Ramona; Sutor, Alexander; Lerch, Reinhard

    2015-05-01

    Magnetostrictive bending cantilevers are applicable for wirelessly measuring physical quantities such as pressure and strain. Exploiting the ΔE-effect, the resonance frequency of the cantilevers is shifted because of a change in the magnetic biasing field. The biasing field, in turn, depends on the applied pressure or strain, respectively. With a view to the application as a reliable sensor, maximum sensitivity but minimum hysteresis in the biasing field/resonance frequency dependence is preferred. In this contribution, monomorph bending cantilevers fabricated using magnetostrictive Fe49Co49V2 and Metglas 2605SA1 are investigated regarding their applicability for future sensors. For this purpose, the biasing field-dependent polarization of the magnetostrictive materials and bending of the cantilevers are determined. Furthermore, a setup to magnetically bias the cantilevers and determine the bending resonance frequency is presented. Here, the resonance frequency is identified by measuring the impulse response employing a laser Doppler vibrometer. The measurement results reveal that cantilevers made of Fe49Co49V2 possess a distinct hysteretic behaviour at low magnetic biasing field magnitudes. This is ascribed to the polarization and bending hysteresis. Cantilevers fabricated using Metglas 2605SA1 feature a lower resonance frequency shift compared to cantilevers with Fe49Co49V2, which would result in a lower sensitivity of the sensor. However, their resonance frequency hysteresis is almost negligible.

  19. Experiments of hydraulics mechanics through different arrangement of submerged bending vegetation

    NASA Astrophysics Data System (ADS)

    Chen, Ye-Hong; Chen, Su Chun

    2014-05-01

    Laboratory experiments are used to explore the effect of different arrangement of submerged bending vegetation in the fixed bed on flow field around vegetation and area downstream. The two simulated bending vegetation were composed of pipe curved to 90 degree for stems and P.P.C films for blades. The two bending vegetation were arranged in alignment and paralleled with flow direction. The test arrangement was distinguished by different overlap rate of vegetation. Overlap rate of vegetation were defined that percentage of blades of bending vegetation overlap the other one. Overlap rate is greater than zero and it means that vegetation overlap the other one. On the other hand, overlap rate is smaller than zero and it means that two plants were separated in percentage of total length of vegetation The experiments were carried out 10 test in forms of overlap rate of vegetation (50%, 25%, 0%,-25%,-50%) by blades of 20cm and 25cm.Velocity and turbulence intensity around the vegetation (u, v, w and urms, vrms, wrms) were acquired by Ultrasound Velocity Profiler (UVP). Furthermore, to elaborate variation of the flow field, the swinging motion of vegetation was recorded by digital camera. Three arrangement types (overlapped, continuous and isolated) were concluded from the 10 tests. In case of isolated vegetation, it could be observed that there was a better effect on slowing flow velocity in x direction in case of the tests with -25% overlap rate due to a discontinuous shear layer between two plants which induced wake interference. It also showed that turbulence intensity was significant between two plants. Two plants disturbed rarely each other in the tests of isolated vegetation with -50% overlap rate .Flow was disturbed by swinging of blades only and returned to stable quickly. In 25% and 50% tests, two plants were overlapped and their behavior was similar to a longer blades plant. Its blades swinging were not obvious result as low effect on slowing velocity in x

  20. Annual bank and point bar morphodynamics of a meandering river determined by high-accuracy multitemporal laser scanning and flow data

    NASA Astrophysics Data System (ADS)

    Lotsari, E.; Vaaja, M.; Flener, C.; Kaartinen, H.; Kukko, A.; Kasvi, E.; Hyyppä, H.; Hyyppä, J.; Alho, P.

    2014-07-01

    The knowledge has been insufficient concerning the effects of peak flows, and local bend and flow characteristics on annual morphodynamics of consecutive bends in meandering rivers. Therefore, it was determined how flow peak magnitude and duration affect morphodynamics, how the short-term spatial evolution of a given meander bend associates with the neighboring bends, and how local bend and flow characteristics affect morphodynamics. The annual bank and point bar morphodynamics of eight consecutive bends of a subarctic meandering river were analyzed between 2009 and 2012 on the basis of high-accuracy multitemporal data, measured by mobile and terrestrial laser scanning and an Acoustic Doppler Current Profiler. According to the results, multiple years of highly accurate data are crucial for a broader picture of meandering channel evolution. The results showed for the first time in detail that none of the years were similar in terms of point bar and bank morphodynamics. The duration of point bar submergence and maximum water stage was more important for evolution of the meandering channel than the local effects of each bend. The detailed topographical data of the present study confirmed that the higher the flow and water stage peak the more deposition occurred on point bars. More importantly, the independence of the short-term spatial evolution of meander bends from the association with neighboring bends was confirmed. Erosion patterns did not relate particularly to the sinuosity or radius of curvature. A clear relation between velocity and bend curvature, on which some meander migration models rely, was not found.

  1. Bathymetric surveys at highway bridges crossing the Missouri River in Kansas City, Missouri, using a multibeam echo sounder, 2010

    USGS Publications Warehouse

    Huizinga, Richard J.

    2010-01-01

    , resulting in a deep channel thalweg on the outside of the bend at these sites. At structure A5817 on State Highway 269, bedrock exposure was evident in the channel thalweg. The surveyed channel bed at a given site from this study generally was lower than the channel bed obtained during Level II scour assessments in 2002. At piers with well-defined scour holes, the frontal slopes of the holes were somewhat less than recommended values in the literature, and the shape of the holes appeared to be affected by the movement of dune features into and around the holes. The channel bed at all of the surveyed sites was lower than the channel bed at the time of construction, and an analysis of measurement data from the U.S. Geological Survey continuous streamflow-gaging station on the Missouri River at Kansas City, Missouri (station number 06893000), confirmed a lowering trend of the channel-bed elevations with time at the gaging station. The size of the scour holes observed at the surveyed sites likely was affected by the moderate flood conditions on the Missouri River at the time of the surveys. The scour holes likely would be substantially smaller during conditions of low flow.

  2. Final MTI Data Report: Pilgrim Nuclear Station

    SciTech Connect

    Parker, M.J.

    2003-03-17

    During the period from May 2000 to September 2001, ocean surface water temperature data was collected at the Pilgrim Nuclear Power Station near Plymouth, MA. This effort was led by the Savannah River Technology Center (SRTC) with the assistance of a local sub-contractor, Marine BioControl Corporation of Sandwich, MA. Permission for setting up the monitoring system was granted by Energy Corporation, which owns the plant site. This work was done in support of SRTC's ground truth mission for the U.S. Department of Energy's Multispectral Thermal Imager (MTI) satellite.

  3. Effect of bend separation distance on the mass transfer in back-to-back pipe bends arranged in a 180° configuration

    NASA Astrophysics Data System (ADS)

    Chen, X.; Le, T.; Ewing, D.; Ching, C. Y.

    2016-02-01

    The mass transfer to turbulent flow through back-to-back pipe bends arranged in a 180° configuration with different lengths of pipe between the bends was measured using a dissolving gypsum test section in water. The measurements were performed for bends with a radius of curvature of 1.5 times the pipe diameter (D) at a Reynolds numbers of 70,000 and Schmidt number of 1280. The maximum mass transfer in the bends decreased from approximately 1.8 times the mass transfer in the upstream pipe when there was no separation distance between the bends to 1.7 times when there was a 1D or 5D length of pipe between the bends. The location of the maximum mass transfer was on the inner sidewall downstream of the second bend when there was no separation distance between the bends. This location changed to the inner wall at the beginning of the second bend when there was a 1D long pipe between the bends, and to the inner sidewall at the end of the first bend when there was a 5D long pipe between the bends.

  4. Shoring pumping station excavation

    SciTech Connect

    Glover, J.B.; Reardon, D.J. )

    1991-11-01

    The city of San Mateo, Calif., operates three 12- to 50-year old wastewater pumping stations on a 24-m (80-ft) wide lot located in a residential area near San Francisco Bay. Because the aging stations have difficulty pumping peak 2.19-m{sup 3}/s (50-mgd) wet-weather flows and have structural and maintenance problems, a new 2.62-m{sup 3}/s (60-mgd) station was proposed - the Dale Avenue Pumping Station - to replace the existing ones. To prevent potential damage to adjacent homes, the new station was originally conceived as a circular caisson type; however, a geotechnical investigation recommended against this type of structure because the stiff soils could make sinking the structure difficult. This prompted an investigation of possible shoring methods for the proposed structure. Several shoring systems were investigated, including steel sheeting, soldier beams and lagging, tieback systems, open excavation, and others; however, each had disadvantages that prevented its use. Because these conventional techniques were unacceptable, attention was turned to using deep soil mixing (DSM) to create a diaphragm wall around the area to be excavated before constructing the pumping station. Although this method has been used extensively in Japan since 1983, the Dale Avenue Pumping Station would be the technology's first US application. The technology's anticipated advantages were its impermeability, its fast and efficient installation that did not require tiebacks under existing homes, its adaptability to subsurface conditions ranging from soft ground to stiff clay to gravels, and its lack of pile-driving requirements that would cause high vibration levels during installation.

  5. Contact and Bending Durability Calculation for Spiral-Bevel Gears

    NASA Technical Reports Server (NTRS)

    Vijayakar, Sandeep

    2016-01-01

    The objective of this project is to extend the capabilities of the gear contact analysis solver Calyx, and associated packages Transmission3D, HypoidFaceMilled, HypoidFaceHobbed. A calculation process for the surface durability was implemented using the Dowson-Higginson correlation for fluid film thickness. Comparisons to failure data from NASA's Spiral Bevel Gear Fatigue rig were carried out. A bending fatigue calculation has been implemented that allows the use of the stress-life calculation at each individual fillet point. The gears in the NASA test rig did not exhibit any bending fatigue failure, so the bending fatigue calculations are presented in this report by using significantly lowered strength numbers.

  6. Simulated Single Tooth Bending of High Temperature Alloys

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert, F.; Burke, Christopher

    2012-01-01

    Future unmanned space missions will require mechanisms to operate at extreme conditions in order to be successful. In some of these mechanisms, very high gear reductions will be needed to permit very small motors to drive other components at low rotational speed with high output torque. Therefore gearing components are required that can meet the mission requirements. In mechanisms such as this, bending fatigue strength capacity of the gears is very important. The bending fatigue capacity of a high temperature, nickel-based alloy, typically used for turbine disks in gas turbine engines and two tool steel materials with high vanadium content, were compared to that of a typical aerospace alloy-AISI 9310. Test specimens were fabricated by electro-discharge machining without post machining processing. Tests were run at 24 and at 490 C. As test temperature increased from 24 to 490 C the bending fatigue strength was reduced by a factor of five.

  7. Stretching and bending in cross-linked biopolymer networks

    NASA Astrophysics Data System (ADS)

    Heussinger, Claus; Frey, Erwin

    2007-03-01

    The elastic response of cross-linked biopolymer networks is usually interpreted in terms of affine stretching models, adopted from the theory of rubber-elasticity valid for flexible polymer gels. Unlike flexible polymers, however, stiff polymers have a highly anisotropic elastic response, where the low-energy elastic excitations are actually of bending nature. As a consequence, similar to springs connected in series, one would expect the softer bending mode to dominate the elastic energy rather than the stiff stretching mode. We propose a theory that, unlike recent affine models, properly accounts for the soft bending response of stiff polymers. It allows calculating the macroscopic elastic moduli starting from a microscopic characterization of the (non-affine) deformation field. The calculated scaling properties for the shear modulus are in excellent agreement with the results of recent simulations obtained in simple two-dimensional model networks, and can also be applied to rationalize bulk rheological data in reconstituted actin networks.

  8. Estimation of blade airloads from rotor blade bending moments

    NASA Technical Reports Server (NTRS)

    Bousman, William G.

    1987-01-01

    A method is developed to estimate the blade normal airloads by using measured flap bending moments; that is, the rotor blade is used as a force balance. The blade's rotation is calculated in vacuum modes and the airloads are then expressed as an algebraic sum of the mode shapes, modal amplitudes, mass distribution, and frequency properties. The modal amplitudes are identified from the blade bending moments using the Strain Pattern Analysis Method. The application of the method is examined using simulated flap bending moment data that have been calculated for measured airloads for a full-scale rotor in a wind tunnel. The estimated airloads are compared with the wind tunnel measurements. The effects of the number of measurements, the number of modes, and errors in the measurements and the blade properties are examined, and the method is shown to be robust.

  9. Modeling of bend effects on fiber Bragg gratings

    NASA Astrophysics Data System (ADS)

    Cadusch, Peter J.; Thompson, Alexander C.; Stoddart, Paul R.; Wade, Scott A.

    2012-02-01

    Sensing and telecommunication applications requiring the bending of optical fibers to small diameters are on the increase. Recent work has shown that the centre wavelength of fiber Bragg gratings has a bend dependence the magnitude of which varies with the type of fiber in which the grating is written. In this work the basis of the centre wavelength shift is investigated by modeling the effects of several potential causes for standard and depressed cladding fiber designs. The majority of the expected affects, including bend induced stress and mode field deformation, were found to result in small wavelength shifts in the opposite direction to those observed experimentally. However, a new account of the shift, based on simplistic geometrical optics, does show wavelength changes in the observed direction, of up to -0.15 nm, which is in the range of the experimentally measured shifts.

  10. Flow resistance of ice slurry in bends and elbow pipes

    NASA Astrophysics Data System (ADS)

    Niezgoda-Żelasko, B.; Żelasko, J.

    2014-08-01

    The present paper covers the flow of ice slurry made of a 10.6% ethanol solution through small-radius bends and elbow pipes. The paper presents the results of experimental research on the flow resistances of Bingham-fluid ice slurry in bends and elbows. The research, performed for three pipe diameters and a relative bend radius of 1<=D/di<=2, has made it possible to take into consideration the influence of friction resistances as well the of the flow geometry on the total local resistance coefficients. The study attempts to make the local resistance coefficient dependent on the Dean number defined for a generalized Reynolds number according to Metzner-Reade

  11. Longitudinal-bending mode micromotor using multilayer piezoelectric actuator.

    PubMed

    Yao, K; Koc, B; Uchino, K

    2001-07-01

    Longitudinal-bending mode ultrasonic motors with a diameter of 3 mm were fabricated using stacked multilayer piezoelectric actuators, which were self-developed from hard lead zirconate titanate (PZT) ceramic. A bending vibration was converted from a longitudinal vibration with a longitudinal-bending coupler. The motors could be bidirectionally operated by changing driving frequency. Their starting and braking torque were analyzed based on the transient velocity response. With a load of moment of inertia 2.5 x 10(-7) kgm2, the motor showed a maximum starting torque of 127.5 microNm. The braking torque proved to be a constant independent on the motor's driving conditions and was roughly equivalent to the maximum starting torque achievable with our micromotors. PMID:11477764

  12. Strain localization and damage development in 2060 alloy during bending

    NASA Astrophysics Data System (ADS)

    Jin, Xiao; Fu, Bao-qin; Zhang, Cheng-lu; Liu, Wei

    2015-12-01

    The microstructure evolution and damage development of the third-generation Al-Li alloy 2060 (T8) were studied using in situ bending tests. Specimens were loaded with a series of punches of different radii, and the microstructure evolution was studied by scanning electron microscopy, electron backscatter diffraction, and digital image correlation (DIC) methods. The evolution of the microscopic fracture strain distribution and microstructure in 2060 alloy during bending was characterized, where the dispersion distribution of precipitates was recorded by backscattered electron imaging and later inputted into a DIC system for strain calculations. The experimental results showed that strain localization in the free surface of bent specimens induced damage to the microstructure. The region of crack initiation lies on the free surface with maximum strain, and the shear crack propagates along the macro-shear band in the early stages of bending. Crack propagation in the later stages was interpreted on the basis of the conventional mechanism of ductile fracture.

  13. Bending properties of foamed aluminum panels and sandwiches

    SciTech Connect

    Simancik, F.; Kovacik, J.; Minarikova, N.

    1998-12-31

    The foamed panels and sandwiches were prepared by powder metallurgical route using various matrix alloys. The effect of the apparent density, geometry and structure of the foam on its bending stiffness was studied with respect to the results of the four-point-bending. It has been shown that the modulus of elasticity of the foam cannot be related only to its apparent density, because the distribution of the cell-wall material along the thickness of the foamed panel is not uniform. Therefore the real moment of inertia of the foam`s cross-section should be used for the calculation of bending stiffness. This moment can be determined from the square weight of the foamed sample.

  14. Platonic Scattering Cancellation for Bending Waves in a Thin Plate

    PubMed Central

    Farhat, M.; Chen, P.-Y.; Bağcı, H.; Enoch, S.; Guenneau, S.; Alù, A.

    2014-01-01

    We propose an ultra-thin elastic cloak to control the scattering of bending waves in isotropic heterogeneous thin plates. The cloak design makes use of the scattering cancellation technique applied, for the first time, to the biharmonic operator describing the propagation of bending waves in thin plates. We first analyze scattering from hard and soft cylindrical objects in the quasistatic limit, then we prove that the scattering of bending waves from an object in the near and far-field regions can be suppressed significantly by covering it with a suitably designed coating. Beyond camouflaging, these findings may have potential applications in protection of buildings from earthquakes and isolating structures from vibrations in the motor vehicle industry. PMID:24844801

  15. [Effect of bending on shot peened and polished osteosynthesis plates].

    PubMed

    Starker, M; Fröhling, M; Hirsch, T

    1991-03-01

    Shot peening can increase the fatigue strength of commercially available surgical plates made of 1.4435 alloy by 40% even in a corrosive environment. Our investigations show that residual stresses resulting from shot peening are reduced by additional bending of the plates. In such plates smaller tensile residual stresses were found than after polishing of the plates. Bending of polished plates results in considerable tensile residual stresses. The hardening achieved by shot peening is not reduced by bending. As the fatigue strength of soft materials depends mainly on the hardening and less on the residual stresses, only little influence of the changed residual stresses on the fatigue strength can be expected. Shot peening of surgical implants thus means an improvement in quality. PMID:2054460

  16. Ultrathin 90-degree sharp bends for spoof surface plasmon polaritons.

    PubMed

    Yang, Yihao; Chen, Hongsheng; Xiao, Sanshui; Mortensen, N Asger; Zhang, Jingjing

    2015-07-27

    At low frequencies outside the plasmonic range, strongly confined surface waves can be achieved on periodically structured metal surfaces, thereby allowing for the design of compact electromagnetic guiding devices. Here, we propose an approach to realize highly efficient transmission of spoof surface plasmons around 90-degree sharp bends on ultrathin metallic films in the microwave regime. We demonstrate that by judiciously engineering the structure, the dispersion relation can be designed to reduce the scattering. Furthermore, the reflection can be suppressed by proper structural decoration at the bending corner. A one-dimensional scattering theory is employed to understand and verify the transmission properties of our waveguide bend structure. Our design scheme is not restricted to the specific structure we propose here but can be applied to other guiding components built up on two dimensional metal surfaces. PMID:26367570

  17. Single crystal plasticity with bend-twist modes

    NASA Astrophysics Data System (ADS)

    Elkhodary, Khalil I.; Bakr, Mohamed A.

    2015-06-01

    In this work a formulation is proposed and computationally implemented for rate dependent single crystal plasticity, which incorporates plastic bend-twist modes that arise from dislocation density based poly-slip mechanisms. The formulation makes use of higher order continuum theory and may be viewed as a generalized micromechanics model. The formulation is then linked to the burgers and Nye tensors, showing how their material rates are derivable from a newly proposed third-rank tensor Λp, which incorporates a crystallographic description of bend-twist plasticity through selectable slip-system level constitutive laws. A simple three-dimensional explicit finite element implementation is outlined and employed in three simulations: (a) bi-crystal bending; (b) tension on a notched single crystal; and (c) the large compression of a microstructure to induce the plastic buckling of secondary phases. All simulation are transient, for computational expediency. The results shed light on the physics resulting from dynamic inhomogeneous plastic deformation.

  18. Platonic Scattering Cancellation for Bending Waves in a Thin Plate

    NASA Astrophysics Data System (ADS)

    Farhat, M.; Chen, P.-Y.; Bağcı, H.; Enoch, S.; Guenneau, S.; Alù, A.

    2014-04-01

    We propose an ultra-thin elastic cloak to control the scattering of bending waves in isotropic heterogeneous thin plates. The cloak design makes use of the scattering cancellation technique applied, for the first time, to the biharmonic operator describing the propagation of bending waves in thin plates. We first analyze scattering from hard and soft cylindrical objects in the quasistatic limit, then we prove that the scattering of bending waves from an object in the near and far-field regions can be suppressed significantly by covering it with a suitably designed coating. Beyond camouflaging, these findings may have potential applications in protection of buildings from earthquakes and isolating structures from vibrations in the motor vehicle industry.

  19. Bending of light in modified gravity at large distances

    NASA Astrophysics Data System (ADS)

    Sultana, Joseph; Kazanas, Demosthenes

    2012-04-01

    We discuss the bending of light in a recent model for gravity at large distances containing a Rindler-type acceleration proposed by Grumiller [Phys. Rev. Lett. 105, 211303 (2010)10.1103/PhysRevLett.105.211303PRLTAO0031-9007]. We consider the static, spherically symmetric metric with cosmological constant Λ and Rindler-like term 2ar presented in this model, and we use the procedure by Rindler and Ishak [W. Rindler and M. Ishak, Phys. Rev. DPRVDAQ1550-7998 76, 043006 (2007).10.1103/PhysRevD.76.043006] to obtain the bending angle of light in this metric. Earlier work on light bending in this model by Carloni, Grumiller, and Preis [Phys. Rev. DPRVDAQ1550-7998 83, 124024 (2011)10.1103/PhysRevD.83.124024], using the method normally employed for asymptotically flat space-times, led to a conflicting result (caused by the Rindler-like term in the metric) of a bending angle that increases with the distance of closest approach r0 of the light ray from the centrally concentrated spherically symmetric matter distribution. However, when using the alternative approach for light bending in nonasymptotically flat space-times, we show that the linear Rindler-like term produces a small correction to the general relativistic result that is inversely proportional to r0. This will in turn affect the bounds on Rindler acceleration obtained earlier from light bending and casts doubts on the nature of the linear term 2ar in the metric.

  20. Large rivers of the United States

    USGS Publications Warehouse

    Iseri, Kathleen T.; Langbein, Walter Basil

    1974-01-01

    Information on the flow of the 28 largest rivers in the United States is presented for the base periods 1931-60 and 1941-70. Drainage area, stream length, source, and mouth are included. Table 1 shows the average discharge at downstream gaging stations. Table 2 lists large rivers in order of average discharge at the mouth, based on the period 1941-70.