Efficiency of two-way weirs and prepositioned electrofishing for sampling potamodromous fish migrations

USGS Publications Warehouse

Favrot, Scott D.; Kwak, Thomas J.

2016-01-01

Potamodromy (i.e., migration entirely in freshwater) is a common life history strategy of North American lotic fishes, and efficient sampling methods for potamodromous fishes are needed to formulate conservation and management decisions. Many potamodromous fishes inhabit medium-sized rivers and are mobile during spawning migrations, which complicates sampling with conventional gears (e.g., nets and electrofishing). We compared the efficiency of a passive migration technique (resistance board weirs) and an active technique (prepositioned areal electrofishers; [PAEs]) for sampling migrating potamodromous fishes in Valley River, a southern Appalachian Mountain river, from March through July 2006 and 2007. A total of 35 fish species from 10 families were collected, 32 species by PAE and 19 species by weir. Species richness and diversity were higher for PAE catch, and species dominance (i.e., proportion of assemblage composed of the three most abundant species) was higher for weir catch. Prepositioned areal electrofisher catch by number was considerably higher than weir catch, but biomass was lower for PAE catch. Weir catch decreased following the spawning migration, while PAEs continued to collect fish. Sampling bias associated with water velocity was detected for PAEs, but not weirs, and neither gear demonstrated depth bias in wadeable reaches. Mean fish mortality from PAEs was five times greater than that from weirs. Catch efficiency and composition comparisons indicated that weirs were effective at documenting migration chronology, sampling nocturnal migration, and yielding samples unbiased by water velocity or habitat, with low mortality. Prepositioned areal electrofishers are an appropriate sampling technique for seasonal fish occupancy objectives, while weirs are more suitable for quantitatively describing spawning migrations. Our comparative results may guide fisheries scientists in selecting an appropriate sampling gear and regime for research, monitoring, conservation, and management of potamodromous fishes.

Alien reef-building polychaete drives long-term changes in invertebrate biomass and diversity in a small, urban estuary

NASA Astrophysics Data System (ADS)

McQuaid, K. A.; Griffiths, C. L.

2014-02-01

Two of the greatest threats to native biodiversity are the construction of artificial structures in natural environments and the introduction of invasive species. As the development and urbanisation of estuaries continues at an increasing rate worldwide, these environments are being simultaneously affected by these threats. This study quantifies the spread of an invasive reef-building polychaete, Ficopomatus enigmaticus, in a small, highly manipulated urban estuary in South Africa and investigates its role as an ecosystem engineer. Anthropogenic changes to the Zandvlei Estuary, including construction of a rubble weir and canalisation near the estuary mouth, construction of an extensive marina development and hardening of the banks with concrete, have facilitated the expansion of F. enigmaticus. The standing stock of F. enigmaticus increased from 13.69 t, as measured in 1986, to 50.03 t in 2012, due both to increase in the total area colonised and standing stock per m2. Since F. enigmaticus reefs support a greater biomass of infauna than adjacent sandy areas, total invertebrate biomass in the estuary is estimated to have increased from less than 0.30 t in 1942, to over 56.80 t in 2012, due mainly to hardening of banks in parts of the main estuary with concrete and construction of a marina system. A positive correlation between reef mass and infaunal biomass, density and diversity was also found.

National Program for Inspection of Non-Federal Dams. Mill Pond Dam MA 00436, Merrimack River Basin, Ashland, Massachusetts. Phase I Inspection Report.

DTIC Science & Technology

1979-04-01

blocked " PL ..wa___________ ,, ,., ~ . , .o ’- ft". o" ,* ." . B-3 w W W W * W * W *0...22. undr M~yrtle Stst oStreet o pC-- C...77 M H PRODIU(J 1) A I (3OVERNJILNT FXP ,.1[ 13. Concrete wall separating two spillways ~wz 14. Eroded earth...berm on downstream side of concrete wall c-8 P I PROOIICH) l GOV [ RNMEFNT FXPFN:;F-, 15. Weir and trapped debris at left (northerly) spillway 16

Approach, passage, and survival of juvenile salmonids at Little Goose Dam, Washington: Post-construction evaluation of a temporary spillway weir, 2009

USGS Publications Warehouse

Beeman, J.W.; Braatz, A.C.; Hansel, H.C.; Fielding, S.D.; Haner, P.V.; Hansen, G.S.; Shurtleff, D.J.; Sprando, J.M.; Rondorf, D.W.

2010-01-01

This report describes a study of dam passage and survival of radio-tagged juvenile salmonids after installation of a temporary spillway weir (TSW) at Little Goose Dam, Washington, in 2009. The purpose of the study was to document fish passage and survival when the dam was operated with the TSW in place. Spillway weirs are one of several methods used to improve downstream passage of juvenile salmonids. Each spillway weir design is based on the concept of providing an overflow weir with a depth more similar to the natural migration depth of juvenile salmonids than conventional spill bays. Little Goose Dam was the last of the four lower Snake River dams to have a spillway weir installed. This was the first year that some form of surface passage device was operating at all Snake River and Columbia River dams between Lewiston, Idaho, and the Columbia River estuary. The study design stipulated that a total of 30 percent of the river discharge would continuously be passed over the TSW and the conventional spill bays, and this percentage was achieved. The TSW also was to be operated at the 'low crest' elevation during the spring and the 'high crest' elevation during the summer, but the TSW was only operated at the low crest elevation during this study. Behavior, passage, and survival of spring and summer juvenile salmonid migrants passing through Little Goose Dam were examined using radio telemetry. Survival was estimated using the Route Specific Survival Model (RSSM) by releasing tagged fish near Central Ferry State Park 21 kilometers upstream of the dam and in the tailrace approximately 0.5 kilometer downstream of the dam. From April 18 to May 21, 2009, 1,520 yearling Chinook salmon (Oncorhynchus tshawytscha) and 1,517 juvenile steelhead (O. mykiss) were radio tagged and released. From June 6 to July 5, 2009, 4,251 subyearling Chinook salmon (O. tshawytscha) were radio tagged and released. Release dates of subyearling Chinook salmon were selected to avoid 'reservoir-type' fish that cease to migrate around July. Detection sites were installed in the forebay 2 kilometers upstream of the dam, on the dam, and at several sites downstream. Detection equipment was operated from April 18 to June 5, 2009, and from June 6 to July 6, 2009, hereinafter referred to as the study periods. We describe passage behaviors through the forebay, main passage routes, and tailrace, survival probabilities through the pool (release to the forebay) and forebay and passage and survival probabilities through the main passage routes (TSW, conventional spill bays, turbines, juvenile bypass), and survival passing the concrete (the dam itself) and the dam (concrete plus the forebay).

Removal of small dams and its influence on physical habitat for salmonids in a Norwegian river

NASA Astrophysics Data System (ADS)

Fjeldstad, Hans-Petter; Barlaup, Bjørn; Stickler, Morten; Alfredsen, Knut; Gabrielsen, Sven-Erik

2010-05-01

While research and implementation of upstream migration solutions is extensive, and indeed often successful, full scale restoration projects and investigations of their influence on fish biology are rare in Norway. Acid deposition in Norwegian catchments peaked in the 1980's and resulted in both chronically and episodically acidified rivers and Salmonids in River Nidelva, one of the largest cathments in southern Norway, where extinct for decades. During this period hydropower development in the river paid limited attention to aquatic ecology. Weirs were constructed for esthetic purposes in the late 1970's and turned a 3 km stretch into a lake habitat, well suited for lake dwelling fish species, but unsuited for migration, spawning and juvenile habitat for salmonids. Since 2005, continuous liming to mitigate acidification has improved the water quality and a program for reintroduction of Atlantic salmon has been implemented. We used hydraulic modeling to plan the removal of two weirs on a bypass reach of the river. The 50 meters wide concrete weirs were blasted and removed in 2007, and ecological monitoring has been carried out in the river to assess the effect of weir removal. Topographic mapping, hydraulic measurements and modeling, in combination with biological surveys before and after the removal of the weirs, has proved to represent a powerful method for design of physical habitat adjustments and assessing their influence on fish biology. The model results also supported a rapid progress of planning and executing of the works. While telemetry studies before weir removal suggested that adult migration past the weirs was delayed with several weeks the fish can now pass the reach with minor obstacles. Spawning sites were discovered in the old bed substrate and were occupied already the first season after water velocities increased to suitable levels for spawning. Accordingly, the densities of Atlantic salmon juveniles have shown a marked increased after the conclusion of the project. Catches of pike and cyprinids on the reach is reduced, indicating that their habitat is no longer suitable, while salmon anglers have found new favorite spots in the restored pools and runs.

Effectiveness of a redesigned water diversion using rock vortex weirs to enhance longitudinal connectivity for small Salmonids

USGS Publications Warehouse

Martens, Kyle D.; Connolly, Patrick J.

2010-01-01

For nearly 100 years, water diversions have affected fish passage in Beaver Creek, a tributary of the lower Methow River in north-central Washington State. From 2000 to 2004, four dam-style water diversions were replaced with a series of rock vortex weirs (RVWs). The weirs were designed to allow fish passage while maintaining the ability to divert water into irrigation canals. We observed the new appearance of three species (juvenile Chinook salmon Oncorhynchus tshawytscha, juvenile coho salmon O. kisutch, and mountain whitefish Prosopium williamsoni) upstream of the RVWs, indicating successful restoration of longitudinal connectivity. We used passive integrated transponder (PIT) tags and instream PIT tag interrogation systems during 2004–2007 to evaluate upstream passage of small salmonids (<240 mm fork length) through one series of RVWs. We documented 109 upstream passage events by small salmonids through the series of RVWs; most of the events (81%) involved passage of rainbow trout O. mykiss or juvenile steelhead (anadromous rainbow trout). Small rainbow trout or steelhead ranging from 86 to 238 mm (adjusted fork length) were able to pass upstream through the RVWs, although a delay in fish passage at discharges below 0.32 m3/s was detected in comparison with nearby control sections.

JPRS Report, Science & Technology China: Energy

DTIC Science & Technology

1992-09-23

combined actual models and math - ematical models to conduct the research and established a total of nine actual models with boundary conditions supplied...10,000 ton-grade flotillas after the Three Gorges project is completed. Simulation experiments of actual passage of 10,000 ton-grade flotillas at...excavate the deep trench for the core wall of the weir for the second phase. Concrete tank cars, spreaders, and other equipment were also devel- oped

National Program for Inspection of Non-Federal Dams. Abbey Lake Dam MA 00305, Connecticut River Basin, Sandisfield, Massachusetts. Phase I Inspection Report.

DTIC Science & Technology

1980-02-01

There are three anti-vortex walls placed perpendicular to and across the top of the weir walls with a solid concrete platform bridging the two upstream...F- cc: wIX 0 0-. w a -- a: U : <w >- w w 0o 0 w ~ I a .. U&SO 5U "* " - . V , -. - - -. -. "." " r ". -V-, .- --- "i - -.- r w

Implementation of Structures in the CMS: Part 2, Weir

DTIC Science & Technology

2013-08-01

sharp - crested weir , it is between 0.55 and 0.58, and a broad - crested ...implementation, different weir coefficients are specified for the weir structure design, sharp - crested or broad - crested weir . The lowest value in the...coefficient range is used for the sharp - crested (0.55) and broad - crested (0.46) weir , respectively; the flux comparison between these two

The Colletotrichum boninense species complex

PubMed Central

Damm, U.; Cannon, P.F.; Woudenberg, J.H.C.; Johnston, P.R.; Weir, B.S.; Tan, Y.P.; Shivas, R.G.; Crous, P.W.

2012-01-01

Although only recently described, Colletotrichum boninense is well established in literature as an anthracnose pathogen or endophyte of a diverse range of host plants worldwide. It is especially prominent on members of Amaryllidaceae, Orchidaceae, Proteaceae and Solanaceae. Reports from literature and preliminary studies using ITS sequence data indicated that C. boninense represents a species complex. A multilocus molecular phylogenetic analysis (ITS, ACT, TUB2, CHS-1, GAPDH, HIS3, CAL) of 86 strains previously identified as C. boninense and other related strains revealed 18 clades. These clades are recognised here as separate species, including C. boninense s. str., C. hippeastri, C. karstii and 12 previously undescribed species, C. annellatum, C. beeveri, C. brassicicola, C. brasiliense, C. colombiense, C. constrictum, C. cymbidiicola, C. dacrycarpi, C. novae-zelandiae, C. oncidii, C. parsonsiae and C. torulosum. Seven of the new species are only known from New Zealand, perhaps reflecting a sampling bias. The new combination C. phyllanthi was made, and C. dracaenae Petch was epitypified and the name replaced with C. petchii. Typical for species of the C. boninense species complex are the conidiogenous cells with rather prominent periclinal thickening that also sometimes extend to form a new conidiogenous locus or annellations as well as conidia that have a prominent basal scar. Many species in the C. boninense complex form teleomorphs in culture. Taxonomic novelties: New combination - Colletotrichum phyllanthi (H. Surendranath Pai) Damm, P.F. Cannon & Crous. Name replacement - C. petchii Damm, P.F. Cannon & Crous. New species - C. annellatum Damm, P.F. Cannon & Crous, C. beeveri Damm, P.F. Cannon, Crous, P.R. Johnst. & B. Weir, C. brassicicola Damm, P.F. Cannon & Crous, C. brasiliense Damm, P.F. Cannon, Crous & Massola, C. colombiense Damm, P.F. Cannon, Crous, C. constrictum Damm, P.F. Cannon, Crous, P.R. Johnst. & B. Weir, C. cymbidiicola Damm, P.F. Cannon, Crous, P.R. Johnst. & B. Weir, C. dacrycarpi Damm, P.F. Cannon, Crous, P.R. Johnst. & B. Weir, C. novae-zelandiae Damm, P.F. Cannon, Crous, P.R. Johnst. & B. Weir, C. oncidii Damm, P.F. Cannon & Crous, C. parsonsiae Damm, P.F. Cannon, Crous, P.R. Johnst. & B. Weir, C. torulosum Damm, P.F. Cannon, Crous, P.R. Johnst. & B. Weir. Typifications: Epitypifications - C. dracaenae Petch. PMID:23136457

Experimental investigation on discharge coefficient for a combined broad crested weir-box culvert structure

NASA Astrophysics Data System (ADS)

Guven, A.; Hassan, M.; Sabir, Shahin

2013-09-01

This study investigates the hydraulic characteristics of simultaneous flow over broad crested weir and through box (square) culverts experimentally. The variation of discharge coefficient (Cd) of the combined structure with various affective parameters such as upstream head, length of culvert, culvert inlet shape, culvert internal dimension, weir crest height, weir side slope angle, and weir width was analyzed. For this purpose 12 glass models of combined broad crested weirs and box culverts were manufactured and tested in a laboratory flume of 12 m. Discharge coefficient predicting equations were developed as a function of the dimensionless terms. The overall results showed that Cd increases as the ratio of the total head of water above the weir crest to the height of the weir crest H/P increases for all the models and for each flow state (weir and combined). Cd values increased as the head increased for all the models tested as culvert flow only, and also with decreasing of the angle between crest of the weir with the sides.

Assessment of Instream Restoration in the Cache River, Illinois: Macroinvertebrate Community Structure on Rock Weirs Compared to Snag and Streambed Habitats

NASA Astrophysics Data System (ADS)

Walther, D. A.; Whiles, M. R.

2005-05-01

Rock weirs were constructed in a degraded section of the Cache River in southern Illinois in 2001 and 2003 to prevent channel incision and protect riparian wetlands. We sampled macroinvertebrates in two older weirs and in two sites downstream of the restored section in April 2003, October 2003, and April 2004 to evaluate differences in community structure between weir, snag, and streambed (scoured clay) habitats. Three recently constructed weirs were also sampled in April 2004. Functional composition differed among sample dates and habitats. Although collector-gatherers consistently dominated streambed habitats, functional composition on weirs and snags was more variable. Filterer and predator biomass was generally higher on weirs, and snags harbored the only shredders collected in the system (Pycnopsyche spp.). Weirs generally supported higher biomass of Ephemeroptera, Plecoptera, and Trichoptera than other habitats. For example, mean EPT biomass on weirs in 2003 (April=187 mgAFDM/m2; October=899 mgAFDM/m2) was 4 to 10-fold higher than EPT biomass in snag or streambed habitats. Late instar Pycnopsyche contributed 41% of snag biomass in April 2004, resulting in EPT biomass similar to rock weirs. Results indicate rock weirs provide suitable stable substrate for macroinvertebrates and may enhance populations of sensitive EPT taxa in degraded systems.

The impact of a small weir on flood risk modelling and management

NASA Astrophysics Data System (ADS)

Bulcock, Amelia; Whitfield, Elizabeth; Andres Lopez-Tarazon, Jose; Whitfield, R. Greg; Byrne, Patrick

2016-04-01

Some ~26,000 obstructions govern British river systems with the majority of these being weirs. Most of the weirs in the UK were built in the 18th century for reasons such as flood control, fishing purposes and navigation. Despite hydroelectric power being at the forefront of new weir construction, many of the existing weirs are being considered for removal to adhere to the Water Framework Directive. However, there are concerns about weir removal regarding increased flood risk, erosion, deposition, pollution redistribution and gradient changes. Before weirs can be removed it is important to understand how a weir is altering a river in order to identify how it may respond to removal; a concept that is poorly understood. Weirs can significantly modify flow regime and sediment transport, ultimately greatly affecting habitats and ecosystems and make constrained rivers behave considerably different to unconstrained channels. The aim of this study is to identify the effect of a weir on morphology, hydraulics, flood risk and sediment transport to determine its current effect and help inform if removal is logical. Hydraulic and sediment transport modeling will be used to determine the effect of the weir on flood risk, flow and sediment transport and historical and present maps to determine morphological changes. Modelling will also be used to establish the effect of removal on flood risk.

Weir Farm National Historic Site : alternative transportation feasibility study

DOT National Transportation Integrated Search

2012-07-31

This report provides an assessment of the feasibility of alternative transportation options to accommodate visitation at Weir Farm National Historic Site in Ridgefield, Connecticut. Weir Farm, the historic home of artist J. Alden Weir, faces numerous...

Impacts of Small Scale Flow Regulation on Sediment Dynamics in an Ecologically Important Upland River

NASA Astrophysics Data System (ADS)

Quinlan, E.; Gibbins, C. N.; Batalla, R. J.; Vericat, D.

2015-03-01

Flow regulation is widely recognized as affecting fluvial processes and river ecosystems. Most impact assessments have focused on large dams and major water transfer schemes, so relatively little is known about the impacts of smaller dams, weirs and water diversions. This paper assesses sediment dynamics in an upland river (the Ehen, NW England) whose flows are regulated by a small weir and tributary diversion. The river is important ecologically due to the presence of the endangered freshwater pearl mussel Margaritifera margaritifera, a species known to be sensitive to sedimentary conditions. Fine sediment yield for the 300-m long study reach was estimated to be 0.057 t km-2 year-1, a very low value relative to other upland UK rivers. Mean in-channel storage of fine sediment was also low, estimated at an average of around 40 g m-2. Although the study period was characterized by frequent high flow events, little movement of coarser bed material was observed. Data therefore indicate an extremely stable fluvial system within the study reach. The implication of this stability for pearl mussels is discussed.

Effects of weir management on marsh loss, Marsh Island, Louisiana, USA

NASA Astrophysics Data System (ADS)

Nyman, John A.; Chabreck, Robert H.; Linscombe, R. G.

1990-11-01

Weirs are low-level dams traditionally used in Louisiana's coastal marshes to improve habitat for ducks and furbearers. Currently, some workers hope that weirs may reduce marsh loss, whereas others fear that weirs may accelerate marsh loss. Parts of Marsh Island, Louisiana, have been weir-managed since 1958 to improve duck and furbearer habitat. Using aerial photographs, marsh loss that occurred between 1957 and 1983 in a 2922-ha weir-managed area was compared to that in a 2365-ha unmanaged area. Marsh loss was 0.38%/yr in the weir-managed area, and 0.35%/yr in the unmanaged area. Because marsh loss in the two areas differed less than 0.19%/yr, it was concluded that weirs did not affect marsh loss. The increase in open water between 1957 and 1983 did not result from the expansion of lakes or bayous. Rather, solid marsh converted to broken marsh, and the amount of vegetation within previously existing broken marsh decreased. Solid marsh farthest from large lakes and bayous, and adjacent to existing broken marsh, seemed more likely to break up. Marsh Island has few canals; therefore, marsh loss resulted primarily from natural processes. Weirs may have different effects under different hydrological conditions; additional studies are needed before generalizations regarding weirs and marsh loss can be made.

77 FR 4290 - Conway Ranch Hydropower Project; Notice of Preliminary Permit Application Accepted for Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-27

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13089-002] Conway Ranch... facilities: (1) A diversion on Virginia Creek (notched weir design); (2) a de minimus reservoir operated run-of river at approximately 8,800 feet elevation above mean sea level; (3) a 2-mile-long, 8-inch...

National Dam Safety Program. Bayman Dam - No Name 381 (MO 20240), Missouri - Kansas City Basin, Jackson County, Missouri. Phase I Inspection Report.

DTIC Science & Technology

1978-08-01

broad - crested weir equation and the sharp crested circular... weir equation. Broad - crested weir equation: Q = CLH 1 .5 (C = varies, L = varies, H is the head on weir ). Circular weir equation: Q = C0 2rR (H0 )5 (C0...the toe of the downstream embankment. The spillway inlet is about 25 feet upstream of the crest of the dam. (3) Pertinent physical data are given

Modeling of Aircraft Deicing Fluid Induced Biochemical Oxygen Demand in Subsurface-Flow Constructed Treatment Wetlands

DTIC Science & Technology

2009-03-01

meters. The input and output control structures are modeled as sharp crested , rectangular weirs one meter in width. The elevation of the input weir is...manipulated by adjusting the width of both the input and output weirs and the crest height of the output weir . All of these adjustments were found to be...reduction of the weir crest height had an effect on the amount of storm water retained during low precipitation conditions, but not on the crest

Concerning human well-being and ecosystems sustainability on water resources management for Qishan River

NASA Astrophysics Data System (ADS)

Wang, C. Y.; Ho, C. C.; Chang, L. C.

2016-12-01

There are no large hydraulic structures in Qishan River cause the less human interference than other major river in Taiwan. However, the aquatic habitats still suffer disturbance from the discharge changes greatly between wet and drought season, and Jiaxian Weir and Yuemei Weir draw surplus water from Qishan River to Nanhua Reservoir and Agongdian Reservoir respectively. The weir operation rule doesn't clear define how much environmental flow should be preserved for maintaining downstream ecological environment. Hence, the study proposes a process for evaluating environmental flow under considering impact on human well-being and ecosystems sustainability. Empirical formula, hydrological, hydraulic and habitat methodologies were used to propose the environmental flow alternatives. Next, water allocation model and Habitat model were used to analysis the impact of environment flow alternatives on human well-being and ecosystems sustainability. The results show the suggested environmental flow in Qishan River is estimated by MAF10%. The environmental flow is between 8.03 10.83 cms during wet season and is between 1.07 1.44cms during wet season. The simulation results also provide the evidence from diverse aspect to help different authorities realized what they get and lose. The information can advance to reach a consensus during negotiations with different authorities and help decision maker make decisions.

Event-based washload transport and sedimentation in and around flood bypasses: Case study from the Sacramento Valley, California

NASA Astrophysics Data System (ADS)

Singer, M. B.; Aalto, R. A.

2005-05-01

In large river systems, suspended sediment transport and deposition patterns are often affected by channel constraints engineered for flood conveyance or navigation. Such managed channels typically have a limited number of overflow loci through which suspended sediment enters the river's floodplain. Engineered flood bypasses are narrow relic floodplains that are supplied by overflow diversion weirs along managed river channels, and support agriculture and complex aquatic and riparian habitats that are sensitive to the delivery of floods, fine sediment, and adsorbed contaminants. They function as wide, shallow conveyance channels parallel to the main river, and therefore present an opportunity to assess the applicability of existing theory for delivery to and settling of suspended sediment within floodplains. This study is an investigation of hydrograph characteristics, sediment delivery, and sedimentation within the upstream reaches of flood bypasses closest to the weir. We present analysis of hydrologic and sediment records and modeling in the Sacramento River basin. The effects of a single large flood in 1964-1965 were analyzed by documenting hydrograph characteristics, computing event-based sediment discharges and reach erosion/deposition through the bypass system, modeling bypass deposition, and comparing modeled results near the weirs with dated sediment cores. The rapidly rising, slowly declining 1964 flood was generated by storm runoff in the Sierra Nevada. The modeling results indicate: washload discharge through the lower valley 0.5 to 1.7 times long-term annual averages; mainstem reach erosion/deposition 0.5 to 1.25 times annual averages; and centimeter scale deposition in flood bypasses. The results are corroborated by a set of sediment cores extracted from Sacramento Valley bypasses, which were dated with 210Pb geochronology and analyzed for grain size. The modeling and data suggest net sediment accumulation between the channel and flood weirs and in the `hydraulic shadow' of the flood weir, the length of which varies depending on flow and sediment characteristics. Net accumulation in the hydraulic shadow is hypothesized to be associated with infrequent, episodic erosion of stored upland mining legacy sediments. As a result, more frequent, relatively clear-water flooding erodes prior bypass sediment deposits at the downstream end of the hydraulic shadow and propagates upstream toward the weir. Such sediment remobilization and scour events were extensively documented in our cores and have implications for the fate and transport of contaminants such as mercury, left over from decades of foothill mining, and for sediment and contaminant delivery to the Sacramento-San Francisco Bay-Delta. The modeling and field data highlighted shortcomings in conventional theory for event-based sediment concentration profiles and particle settling. These limitations could be addressed with appropriate data collection and model revision to account for the processes of sediment transport over weirs and into flood conveyance channels.

Physical modeling of river spanning rock structures: Evaluating interstitial flow, local hydraulics, downstream scour development, and structure stability

USGS Publications Warehouse

Collins, K.L.; Thornton, C.I.; Mefford, B.; Holmquist-Johnson, C. L.

2009-01-01

Rock weir and ramp structures uniquely serve a necessary role in river management: to meet water deliveries in an ecologically sound manner. Uses include functioning as low head diversion dams, permitting fish passage, creating habitat diversity, and stabilizing stream banks and profiles. Existing information on design and performance of in-stream rock structures does not provide the guidance necessary to implement repeatable and sustainable construction and retrofit techniques. As widespread use of rock structures increases, the need for reliable design methods with a broad range of applicability at individual sites grows as well. Rigorous laboratory testing programs were implemented at the U.S. Bureau of Reclamation (Reclamation) and at Colorado State University (CSU) as part of a multifaceted research project focused on expanding the current knowledge base and developing design methods to improve the success rate of river spanning rock structures in meeting project goals. Physical modeling at Reclamation is being used to measure, predict, and reduce interstitial flow through rock ramps. CSU is using physical testing to quantify and predict scour development downstream of rock weirs and its impact on the stability of rock structures. ?? 2009 ASCE.

National Dam Safety Program. St. Joe State Park Dam (MO 30277), Mississippi - Kaskaskia - St. Louis Basin, St. Francois County, Missouri. Phase I Inspection Report.

DTIC Science & Technology

1980-02-01

discharge coefficient of C = 3.4 was used. 0 Orifice flow condition when the reservoir water surface sub- merges the inlet opening. * Broad crested weir flow...2.7 was used. The intake tower will operate as a weir , as a weir and an orifice, or as an orifice and a broad crested weir depending upon the...spillway C prior to overtopping the railroad embankment into the original dam pond. Flow over this low point was calculated as flow over a broad crested weir

Weirs: Counting and sampling adult salmonids in streams and rivers

USGS Publications Warehouse

Zimmerman, Christian E.; Zabkar, Laura M.; Johnson, David H.; Shrier, Brianna M.; O'Neal, Jennifer S.; Knutzen, John A.; Augerot, Xanthippe; O'Neal, Thomas A.; Pearsons, Todd N.

2007-01-01

Weirs—which function as porous barriers built across stream—have long been used to capture migrating fish in flowing waters. For example, the Netsilik peoples of northern Canada used V-shaped weirs constructed of river rocks gathered onsite to capture migrating Arctic char Salvelinus alpinus (Balikci 1970). Similarly, fences constructed of stakes and a latticework of willow branches or staves were used by Native Americans to capture migrating salmon in streams along the West Coast of North America (Stewart 1994). In modern times, weirs have also been used in terminal fisheries and to capture brood fish for use in fish culture. Weirs have been used to gather data on age structure, condition, sex ratio, spawning escapement, abundance, and migratory patterns of fish in streams. One of the critical elements of fisheries management and stock assessment of salmonids is a count of adult fish returning to spawn. Weirs are frequently used to capture or count fish to determine status and trends of populations or direct inseason management of fisheries; generally, weirs are the standard against which other techniques are measured. To evaluate fishery management actions, the number of fish escaping to spawn is often compared to river-specific target spawning requirements (O’Connell and Dempson 1995). A critical factor in these analyses is the determination of total run size (O’Connell 2003). O’Connell compared methods of run-size estimation against absolute counts from a rigid weir and concluded that, given the uncertainty of estimators, the absolute counts obtained at the weir wer significantly better than modeled estimates, which deviated as much as 50–60% from actual counts. The use of weirs is generally restricted to streams and small rivers because of construction expense, formation of navigation barriers, and the tendency of weirs to clog with debris, which can cause flooding and collapse of the structure (Hubert 1996). When feasible, however, weirs are generally regarded as the most accurate technique available to quantify escapement as the result is supposedly an absolute count (Cousens et al. 1982). Weirs also provide the opportunity to capture fish for observation and sampling of biological characteristics and tissues; they may also serve as recapture sites for basin-wide, mark–recapture population estimates. Temporary weirs are useful in monitoring wild populations of salmonids as well as for capturing broodstock for artificial propagation.

A Saxon Fish Weir and Undated Fish Trap Frames Near Ashlett Creek, Hampshire, UK: Static Structures on a Dynamic Foreshore

NASA Astrophysics Data System (ADS)

Cooper, John P.; Caira, Gianni; Opdebeeck, Johan; Papadopoulou, Chryssanthi; Tsiairis, Vassilis

2017-04-01

The remains of a wooden V-shaped fish weir and associated structures have been discovered near Ashlett Creek on the tidal mudflats of Southampton Water in Hampshire, southern Britain. Radiocarbon dating of oak roundwood stakes taken from the main weir structure date it to the middle Saxon period. Clusters of as-yet undated roundwood posts within the catchment area of the weir are interpreted as the frames for fish traps that are assumed to pre- or post-date the operational period of the weir itself. The weir is contemporary with wooden V-shaped fish weirs found elsewhere in southern and central Britain, and also Ireland, but its circular catchment `pound' remains restricted, in these islands, to the Solent and Severn estuaries: it has a close parallel with another Saxon-era weir on the nearby Isle of Wight. It also shows striking structural similarities with examples in use today in Basse Normandy, on the southern shore of the English Channel. The paper discusses the function and operation of the weir, and places it in its social and historical context. Regressive cartography demonstrates that the structures have become exposed as a result of saltmarsh retreat in this area of Southampton Water since the nineteenth century. The radiocarbon dates returned for the posts demonstrate that this transgression of the marsh must have been preceded by a prolonged period of progradation, which covered and preserved the site; its subsequent re-exposure has negative implications for its survival.

Spatio-temporal variation of stream-aquifer interaction: Effect of a weir construction in Korea

NASA Astrophysics Data System (ADS)

Lee, Hyeonju; Koo, Min-Ho; Kim, Kisu; Kim, Yongcheol

2015-04-01

The Four Major Rivers Restoration Project was conducted to secure sufficient water resources, introduce comprehensive flood control measures, and improve water quality while restore the river ecosystem in Korea. The dredging of river bed and the installation of 16 weirs were done in Han, Geum, Yeongsan, and Nakdong rivers from late 2010 to early 2012 as a part of the project. Groundwater data obtained from 213 groundwater monitoring wells near the four major rivers were used to analyze the impacts of weir construction on the nearby groundwater flow system. The groundwater level and chemical characteristics were analyzed to investigate how the groundwater flow system and water quality changed after the weir construction. The results showed that groundwater level rose immediately following the rise of stream stage after the weir construction. Also, the hydrologic condition of the stream in some upland of the weirs was changed from a gaining to a losing stream. Consequently, the direction of groundwater flow was changed from perpendicular to parallel to the stream, and it swapped the groundwater in the downstream of the weir for the water recharged from the stream. Considering the results, some groundwater quality is expected to be changed and become similar to that of the stream, although the change has been not observed yet. Therefore, both further monitoring of the groundwater quality and hydrogeochemical analysis are required for quantitatively evaluating the effect of the weir.

Hydraulic and biological analysis of the passability of select fish species at the U.S. Geological Survey streamgaging weir at Blackwells Mills, New Jersey

USGS Publications Warehouse

Haro, Alexander J.; Mulligan, Kevin; Suro, Thomas P.; Noreika, John; McHugh, Amy

2017-10-16

Recent efforts to advance river connectivity for the Millstone River watershed in New Jersey have led to the evaluation of a low-flow gauging weir that spans the full width of the river. The methods and results of a desktop modelling exercise were used to evaluate the potential ability of three anadromous fish species (Alosa sapidissima [American shad], Alosa pseudoharengus [alewife], and Alosa aestivalis [blueback herring]) to pass upstream over the U.S. Geological Survey Blackwells Mills streamgage (01402000) and weir on the Millstone River, New Jersey, at various streamflows, and to estimate the probability that the weir will be passable during the spring migratory season. Based on data from daily fishway counts downstream from the Blackwells Mills streamgage and weir between 1996 and 2014, the general migratory period was defined as April 14 to May 28. Recorded water levels and flow data were used to theoretically estimate water depths and velocities over the weir, as well as flow exceedances occurring during the migratory period.Results indicate that the weir is a potential depth barrier to fish passage when streamflows are below 200 cubic feet per second using a 1-body-depth criterion for American shad (the largest fish among the target species). Streamflows in that range occur on average 35 percent of the time during the migratory period. An increase of the depth criterion to 2 body depths causes the weir to become a possible barrier to passage when flows are below 400 cubic feet per second. Streamflows in that range occur on average 73 percent of the time during the migration season. Average cross-sectional velocities at several points along the weir do not seem to be limiting to the fish migration, but maximum theoretical velocities estimated without friction loss over the face of the weir could be potentially limiting.

Development of a Distributed Nutrient Sub-Model (NSM Version 1.0) for Watersheds - Kinetic Process Descriptions

DTIC Science & Technology

2006-11-01

Broad Crested Weir 0.70 to 0.90 Sharp Crested Weir with Straight Slope Face 1.05 Sharp Crested Weir with Vertical Face 0.80 Sluice Gates with...Reaeration by turbulent flow over a dam Reaeration will occur when water falls over a dam, weir , or other structure in the stream. The amount of reaeration...Goulding. 1995. Phosphorus leaching from soils containing different phosphorus concentrations in the Broad - balk experiment. J. Environ. Qual. 24:904–910

New type side weir discharge coefficient simulation using three novel hybrid adaptive neuro-fuzzy inference systems

NASA Astrophysics Data System (ADS)

Bonakdari, Hossein; Zaji, Amir Hossein

2018-03-01

In many hydraulic structures, side weirs have a critical role. Accurately predicting the discharge coefficient is one of the most important stages in the side weir design process. In the present paper, a new high efficient side weir is investigated. To simulate the discharge coefficient of these side weirs, three novel soft computing methods are used. The process includes modeling the discharge coefficient with the hybrid Adaptive Neuro-Fuzzy Interface System (ANFIS) and three optimization algorithms, namely Differential Evaluation (ANFIS-DE), Genetic Algorithm (ANFIS-GA) and Particle Swarm Optimization (ANFIS-PSO). In addition, sensitivity analysis is done to find the most efficient input variables for modeling the discharge coefficient of these types of side weirs. According to the results, the ANFIS method has higher performance when using simpler input variables. In addition, the ANFIS-DE with RMSE of 0.077 has higher performance than the ANFIS-GA and ANFIS-PSO methods with RMSE of 0.079 and 0.096, respectively.

Sluiceway Operations to Pass Juvenile Salmonids at The Dalles Dam, Columbia River, USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Gary E.; Khan, Fenton; Skalski, J. R.

Existing ice and trash sluiceways are commonly used to pass juvenile salmonids downstream at hydropower dams through a benign, non-turbine route. At The Dalles Dam on the Columbia River, managers undertook optimizing operations of sluiceway weirs to maximize survival of juvenile salmonids at the powerhouse. We applied fixed-location hydroacoustic methods to compare fish passage rates and sluiceway efficiencies for two weir configurations during 2004 and 2005: three weirs versus six weirs, located at the mid- versus east powerhouse, respectively. We also analyzed horizontal distributions of passage at the sluiceway and turbines and the effects of operating turbines beneath open sluicewaymore » gates to provide supporting data relevant to operations optimization. Based on the findings, we recommend the following for long-term operations for the sluiceway at The Dalles Dam: open six rather than three sluiceway weirs to take advantage of the maximum hydraulic capacity of the sluiceway; open the three weirs above the western-most operating main turbine unit (MU) and the three weirs at MU 8 where turbine passage rates are relatively high; operate the turbine units below open sluiceway weirs as a standard procedure; operate the sluiceway 24 h/d year-round to maximize its benefits to juvenile salmonids; and use the same operations for spring and summer emigrants. These operational concepts are transferable to dams where sluiceway surface flow outlets are used protect downstream migrating fishes.« less

Do weirs affect the physical and geochemical mobility of toxic metals in mining-impacted floodplain sediments?

NASA Astrophysics Data System (ADS)

Bulcock, Amelia; Coleman, Alexandra; Whitfield, Elizabeth; Andres Lopez-Tarazon, Jose; Byrne, Patrick; Whitfield, Greg

2015-04-01

Weirs are common river structures designed to modify river channel hydraulics and hydrology for purposes of navigation, flood defence, irrigation and hydrometry. By design, weirs constrain natural flow processes and affect sediment flux and river channel forms leading to homogenous river habitats and reduced biodiversity. The recent movement towards catchment-wide river restoration, driven by the EU Water Framework Directive, has recognised weirs as a barrier to good ecological status. However, the removal of weirs to achieve more 'natural' river channels and flow processes is inevitably followed by a period of adjustment to the new flow regime and sediment flux. This period of adjustment can have knock-on effects that may increase flood risk, sedimentation and erosion until the river reaches a state of geomorphological equilibrium. Many catchments in the UK contain a legacy of toxic metals in floodplain sediments due to historic metal mining activities. The consequences of weir removal in these catchments may be to introduce 'stored' mine wastes into the river system with severe implications for water quality and biodiversity. The purpose of this study is to investigate the potential impact of a weir on the physical and geochemical mobilisation of mine wastes in the formerly mined River Twymyn catchment, Wales. Our initial investigations have shown floodplain and riverbed sediments to be grossly contaminated (up to 15,500 mg/kg Pb) compared to soil from a pre-mining Holocene terrace (180 mg/kg Pb). Geomorphological investigations also suggest that weir removal will re-establish more dynamic river channel processes resulting in lateral migration of the channel and erosion of contaminated floodplain sediments. These data will be used as a baseline for more detailed investigations of the potential impact of weirs on the physical and geochemical mobilisation of contaminated sediments. We have two specific objectives. (1) Geomorphological assessments will use unmanned aerial vehicle (UAV) photographic surveys, historical aerial photographs, ground-based topographic surveys, surface and subsurface particle size determination, bed stability and sediment entrainment assessment, together with discharge and sediment (both suspended and bedload) monitoring to establish the effect of the weir on patterns of sediment flux and the physical transport of metal contaminants. 2D and 1D models (IBER, HEC-RAS) of the weir-affected reach will investigate sediment and metal flux following weir removal. (2) The physicochemical speciation and geochemical stability of contaminated floodplain sediments will be characterised using bulk chemistry, mineralogical (XRD, SEM) and speciation methods (sequential extractions, electron microprobe analysis).

Passive containment cooling water distribution device

DOEpatents

Conway, Lawrence E.; Fanto, Susan V.

1994-01-01

A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using a series of radial guide elements and cascading weir boxes to collect and then distribute the cooling water into a series of distribution areas through a plurality of cascading weirs. The cooling water is then uniformly distributed over the curved surface by a plurality of weir notches in the face plate of the weir box.

An efficient smolt trap for sandy and debris-laden streams

USGS Publications Warehouse

Scace, J.G.; Letcher, B.H.; Noreika, J.

2007-01-01

Tripod weir and box traps are traditionally used to capture and enumerate out-migrating salmonid smolts in short-term studies and in streams where temporary or portable traps are the only practical option. Although traditional traps can be effective when conditions are ideal, they are often unable to withstand high-discharge events in streams containing a large amount of debris or sandy substrates. We created a rotary-screw trap and resistance board weir hybrid design that we evaluated along with a tripod weir and box trap, both in a 6.1-m-wide flume and in the field. The new design outperformed the tripod weir in both situations. The tripod weir failed in 10 min in the flume trial, whereas the new design was still operating at the conclusion of an 8-h trial under the same conditions. The new design operated continuously in the field during a high-discharge event that caused the tripod weir to fail. The new design also required less frequent cleaning than the tripod weir. The trap efficiency of the new design was estimated by using passive integrated transponder (PIT) tag antennas and radiotelemetry. The trap was 80% efficient (n = 40) in capturing migrating PIT-tagged individuals detected at an antenna upstream of the trap and 87.5% efficient (n = 48) at recapturing fish that had been tagged and released upstream. With its high efficiency and increased resiliency over the tripod weir, the new trap design will benefit management and research efforts in streams where traditional traps are unsuitable. ?? Copyright by the American Fisheries Society 2007.

Determining the spill flow discharge of combined sewer overflows using rating curves based on computational fluid dynamics instead of the standard weir equation.

PubMed

Fach, S; Sitzenfrei, R; Rauch, W

2009-01-01

It is state of the art to evaluate and optimise sewer systems with urban drainage models. Since spill flow data is essential in the calibration process of conceptual models it is important to enhance the quality of such data. A wide spread approach is to calculate the spill flow volume by using standard weir equations together with measured water levels. However, these equations are only applicable to combined sewer overflow (CSO) structures, whose weir constructions correspond with the standard weir layout. The objective of this work is to outline an alternative approach to obtain spill flow discharge data based on measurements with a sonic depth finder. The idea is to determine the relation between water level and rate of spill flow by running a detailed 3D computational fluid dynamics (CFD) model. Two real world CSO structures have been chosen due to their complex structure, especially with respect to the weir construction. In a first step the simulation results were analysed to identify flow conditions for discrete steady states. It will be shown that the flow conditions in the CSO structure change after the spill flow pipe acts as a controlled outflow and therefore the spill flow discharge cannot be described with a standard weir equation. In a second step the CFD results will be used to derive rating curves which can be easily applied in everyday practice. Therefore the rating curves are developed on basis of the standard weir equation and the equation for orifice-type outlets. Because the intersection of both equations is not known, the coefficients of discharge are regressed from CFD simulation results. Furthermore, the regression of the CFD simulation results are compared with the one of the standard weir equation by using historic water levels and hydrographs generated with a hydrodynamic model. The uncertainties resulting of the wide spread use of the standard weir equation are demonstrated.

Spatial Variations of DOM Compositions in the River with Multi-functional Weir

NASA Astrophysics Data System (ADS)

Yoon, S. M.; Choi, J. H.

2017-12-01

With the global trend to construct artificial impoundments over the last decades, there was a Large River Restoration Project conducted in South Korea from 2010 to 2011. The project included enlargement of river channel capacity and construction of multi-functional weirs, which can alter the hydrological flow of the river and cause spatial variations of water quality indicators, especially DOM (Dissolved Organic Matter) compositions. In order to analyze the spatial variations of organic matter, water samples were collected longitudinally (5 points upstream from the weir), horizontally (left, center, right at each point) and vertically (1m interval at each point). The specific UV-visible absorbance (SUVA) and fluorescence excitation-emission matrices (EEMs) have been used as rapid and non-destructive analytical methods for DOM compositions. In addition, parallel factor analysis (PARAFAC) has adopted for extracting a set of representative fluorescence components from EEMs. It was assumed that autochthonous DOM would be dominant near the weir due to the stagnation of hydrological flow. However, the results showed that the values of fluorescence index (FI) were 1.29-1.47, less than 2, indicating DOM of allochthonous origin dominated in the water near the weir. PARAFAC analysis also showed the peak at 450 nm of emission and < 250 nm of excitation which represented the humic substances group with terrestrial origins. There was no significant difference in the values of Biological index (BIX), however, values of humification index (HIX) spatially increased toward the weir. From the results of the water sample analysis, the river with multi-functional weir is influenced by the allochthonous DOM instead of autochthonous DOM and seems to accumulate humic substances near the weir.

Numerical simulation of overflow at vertical weirs using a hybrid level set/VOF method

NASA Astrophysics Data System (ADS)

Lv, Xin; Zou, Qingping; Reeve, Dominic

2011-10-01

This paper presents the applications of a newly developed free surface flow model to the practical, while challenging overflow problems for weirs. Since the model takes advantage of the strengths of both the level set and volume of fluid methods and solves the Navier-Stokes equations on an unstructured mesh, it is capable of resolving the time evolution of very complex vortical motions, air entrainment and pressure variations due to violent deformations following overflow of the weir crest. In the present study, two different types of vertical weir, namely broad-crested and sharp-crested, are considered for validation purposes. The calculated overflow parameters such as pressure head distributions, velocity distributions, and water surface profiles are compared against experimental data as well as numerical results available in literature. A very good quantitative agreement has been obtained. The numerical model, thus, offers a good alternative to traditional experimental methods in the study of weir problems.

A simulation for the gated weir opening of Wonokromo River, Rungkut District, Surabaya

NASA Astrophysics Data System (ADS)

Handajani, N.; Wahjudijanto, I.; Mu'afi, M.

2018-01-01

The gated weir is a weir that the crest elevation could be operated based on the flow through the river. The upstream water level of the gated weir could be controlled with gate opening or closing. This study applied a simulation with HEC-RAS 4,0 program in order to know the river hydraulic condition after the gated weir has built. According to the rainfall intensity from each sub-watershed, Distribution Log Pearson III with return period 50 years (Q50) was determined to calculate the design flood discharge. By using Rational Method, the design flood discharge is 470 m3/s. The Results show that capacity of the river is able to accomodate Q50 with discharge 470 m3/s and the gate should be fully opened during flood. This condition could passed the normal discharge at + 5.00 m elevation.

Responses of aquatic macrophytes to anthropogenic pressures: comparison between macrophyte metrics and indices.

PubMed

Camargo, Julio A

2018-02-26

Macrophyte responses to anthropogenic pressures in two rivers of Central Spain were assessed to check if simple metrics can exhibit a greater discriminatory and explanatory power than complex indices at small spatial scales. Field surveys were undertaken during the summer of 2014 (Duraton River) and the spring of 2015 (Tajuña River). Aquatic macrophytes were sampled using a sampling square (45 × 45 cm). In the middle Duraton River, macrophytes responded positively to the presence of a hydropower dam and a small weir, with Myriophyllum spicatum and Potamogeton pectinatus being relatively favored. Index of Macrophytes (IM) was better than Macroscopic Aquatic Vegetation Index (MAVI) and Fluvial Macrophyte Index (FMI) in detecting these responses, showing positive and significant correlations with total coverage, species richness, and species diversity. In the upper Tajuña River, macrophytes responded both negatively and positively to the occurrence of a trout farm effluent and a small weir, with Leptodictyum riparium and Veronica anagallis-aquatica being relatively favored. Although IM, MAVI, and FMI detected both negative and positive responses, correlations of IM with total coverage, species richness, and species diversity were higher. Species evenness was not sensitive enough to detect either positive or negative responses of aquatic macrophytes along the study areas. Overall, traditional and simple metrics (species composition, total coverage, species richness, species diversity) exhibited a greater discriminatory and explanatory power than more recent and complex indices (IM, MAVI, FMI) when assessing responses of aquatic macrophytes to anthropogenic pressures at impacted specific sites.

Measurement of peak discharge at dams by indirect methods

USGS Publications Warehouse

Hulsing, Harry

1967-01-01

This chapter describes procedures for measuring peak discharges using dams, weirs, and embankments. Field and office procedures limited to this method are described. Discharge coefficients and formulas are given for three general classes of weirs-sharp-crested, broad-crested, and round-crested-and for highway embankments and weirs of unusual shape. The effects of submergence are defined for most forms.

Effects of Orifice-Weir Outlet on Hydrology and Water Quality of a Drained Forested Watershed

Treesearch

Devendra M. Amatya; R. Wayne Skaggs; J.W. Gilliam; J.H. Hughes

2003-01-01

Orifice-weir structures at ditch outlets are proposed to reduce peak drainage rates during high flows and to store water during the growing season in poorly drained managed pine plantations. Two coastal watersheds, one conventionally drained (D1) and another with an orifice-weir outlet (D3), were monitored to examine the effects of this orifice treatment on drainage...

The Colletotrichum gloeosporioides species complex

PubMed Central

Weir, B.S.; Johnston, P.R.; Damm, U.

2012-01-01

The limit of the Colletotrichum gloeosporioides species complex is defined genetically, based on a strongly supported clade within the Colletotrichum ITS gene tree. All taxa accepted within this clade are morphologically more or less typical of the broadly defined C. gloeosporioides, as it has been applied in the literature for the past 50 years. We accept 22 species plus one subspecies within the C. gloeosporioides complex. These include C. asianum, C. cordylinicola, C. fructicola, C. gloeosporioides, C. horii, C. kahawae subsp. kahawae, C. musae, C. nupharicola, C. psidii, C. siamense, C. theobromicola, C. tropicale, and C. xanthorrhoeae, along with the taxa described here as new, C. aenigma, C. aeschynomenes, C. alatae, C. alienum, C. aotearoa, C. clidemiae, C. kahawae subsp. ciggaro, C. salsolae, and C. ti, plus the nom. nov. C. queenslandicum (for C. gloeosporioides var. minus). All of the taxa are defined genetically on the basis of multi-gene phylogenies. Brief morphological descriptions are provided for species where no modern description is available. Many of the species are unable to be reliably distinguished using ITS, the official barcoding gene for fungi. Particularly problematic are a set of species genetically close to C. musae and another set of species genetically close to C. kahawae, referred to here as the Musae clade and the Kahawae clade, respectively. Each clade contains several species that are phylogenetically well supported in multi-gene analyses, but within the clades branch lengths are short because of the small number of phylogenetically informative characters, and in a few cases individual gene trees are incongruent. Some single genes or combinations of genes, such as glyceraldehyde-3-phosphate dehydrogenase and glutamine synthetase, can be used to reliably distinguish most taxa and will need to be developed as secondary barcodes for species level identification, which is important because many of these fungi are of biosecurity significance. In addition to the accepted species, notes are provided for names where a possible close relationship with C. gloeosporioides sensu lato has been suggested in the recent literature, along with all subspecific taxa and formae speciales within C. gloeosporioides and its putative teleomorph Glomerella cingulata. Taxonomic novelties: Name replacement - C. queenslandicum B. Weir & P.R. Johnst. New species - C. aenigma B. Weir & P.R. Johnst., C. aeschynomenes B. Weir & P.R. Johnst., C. alatae B. Weir & P.R. Johnst., C. alienum B. Weir & P.R. Johnst, C. aotearoa B. Weir & P.R. Johnst., C. clidemiae B. Weir & P.R. Johnst., C. salsolae B. Weir & P.R. Johnst., C. ti B. Weir & P.R. Johnst. New subspecies - C. kahawae subsp. ciggaro B. Weir & P.R. Johnst. Typification: Epitypification - C. queenslandicum B. Weir & P.R. Johnst. PMID:23136459

Environmental Impact Research Program. Ecological Effects of Rubble Weir Jetty Construction at Murrells Inlet, South Carolina. Volume 1. Colonization and Community Development on New Jetties.

DTIC Science & Technology

1984-04-01

was not ., defined but approximated 65 cm2. d. Fish Observations and Collections Qualitative observations on ichthyofauna were made during...that P. caudata occurred mainly among algae, seagrass , sponges and the like insubtidal waters. Corophiwu sp. showed significantly greater abundance on...abundance and diversity of ichthyofauna in areas where they are present (Hastings, 1972, 1978; Hurme, 1979). A large number of fishes were observed on or

New notch weir system designed to pass shad through Potomac Dam

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-08-01

This article discusses the design and functional characteristics of a notch and three-weir labyrinth fish passage facility at Little Falls Dam. Most effective at low-head hydroelectric power plants, the weir system will reduce flow velocities to a value thought to be low enough for healthy shad to swim against. It is felt that this system will re-establish the shad population in a 10-mile stretch of the Patomac River near Washington.

Optimization of spent fuel pool weir gate driving mechanism

NASA Astrophysics Data System (ADS)

Liu, Chao; Du, Lin; Tao, Xinlei; Wang, Shijie; Shang, Ertao; Yu, Jianjiang

2018-04-01

Spent fuel pool is crucial facility for fuel storage and nuclear safety, and the spent fuel pool weir gate is the key related equipment. In order to achieve a goal of more efficient driving force transfer, loading during the opening/closing process is analyzed and an optimized calculation method for dimensions of driving mechanism is proposed. The result of optimizing example shows that the method can be applied to weir gates' design with similar driving mechanism.

2015 Summer Series - Andy Weir - The Martian: How Science Drove the Plot

NASA Image and Video Library

2015-06-30

NASA's Journey to Mars sets a goal beyond anything humanity has ever reached. With this monumental vision, we outline the parameters needed for survival. We put ourselves into the spacesuit of a Martian explorer and design what they need. In his novel, The Martian, Andy Weir communicates a quest for survival-- a thought experiment in innovation and ingenuity. Andy Weir will describe how science drove the plot of The Martian, illuminating the connectivity between science fiction and science fact.

27. DIVERSION STRUCTURE WITH CONCRETE SIDEWALLS AND CONCRETE CHANNEL BEYOND, ...

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

27. DIVERSION STRUCTURE WITH CONCRETE SIDEWALLS AND CONCRETE CHANNEL BEYOND, A SHORT DISTANCE WEST OF D STREET ABOUT ONE-QUARTER MILE SOUTH OF 9TH AVENUE (SECTION 26). - Highline Canal, Sand Creek Lateral, Beginning at intersection of Peoria Street & Highline Canal in Arapahoe County (City of Aurora), Sand Creek lateral Extends 15 miles Northerly through Araphoe County, City & County of Denver, & Adams County to its end point, approximately 1/4 mile Southest of intersectioin of D Street & Ninth Avenue in Adams County (Rocky Mountain Arsenal, Commerce City Vicinity), Commerce City, Adams County, CO

San Francisquito Creek Stabilization at Bonde Weir Project

EPA Pesticide Factsheets

Information about the SFBWQP San Francisquito Creek Stabilization at Bonde Weir Project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

10. DETAIL VIEW OF RIVERCOBBLE WEIR WALL OF THE SPILLWAY ...

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

10. DETAIL VIEW OF RIVER-COBBLE WEIR WALL OF THE SPILLWAY NEAR THE EAST END, DAM 87, LOOKING NORTHWEST - Upper Souris National Wildlife Refuge, Dam 87, Souris River Basin, Foxholm, Surrey (England), ND

Cooling system for a gas turbine using a cylindrical insert having V-shaped notch weirs

DOEpatents

Grondahl, Clayton M.; Germain, Malcolm R.

1981-01-01

An improved cooling system for a gas turbine is disclosed. A plurality of V-shaped notch weirs are utilized to meter a coolant liquid from a pool of coolant into a plurality of platform and airfoil coolant channels formed in the buckets of the turbine. The V-shaped notch weirs are formed in a separately machined cylindrical insert and serve to desensitize the flow of coolant into the individual platform and airfoil coolant channels to design tolerances and non-uniform flow distribution.

Two Dimensional Movement Patterns of Juvenile Winter Run and Late Fall Run Chinook Salmon at the Fremont Weir, Sacramento River, CA

DTIC Science & Technology

2017-07-01

ER D C/ EL T R- 17 -1 0 Two-Dimensional Movement Patterns of Juvenile Winter- Run and Late-Fall- Run Chinook Salmon at the Fremont Weir...default. ERDC/EL TR-17-10 July 2017 Two-Dimensional Movement Patterns of Juvenile Winter- Run and Late-Fall- Run Chinook Salmon at the Fremont Weir...Sacramento River, smaller winter- run Chinook and larger late-fall- run Chinook salmon were tagged and released into a 2D telemetry array dur- ing the

A Tracer Test at the Los Alamos Canyon Weir

NASA Astrophysics Data System (ADS)

Levitt, D. G.; Stone, W. J.; Newell, D. L.; Wykoff, D. S.

2002-12-01

A low-head weir was constructed in the Los Alamos Canyon to reduce the transport of contaminant-bearing sediment caused by fire-enhanced runoff off Los Alamos National Laboratory (LANL) property towards the Rio Grande following the May 2000 Cerro Grande fire at Los Alamos, New Mexico. Fractured basalt was exposed in the channel by grading during construction of the weir, and water temporarily ponds behind the weir following periods of runoff. In order to monitor any downward transport of contaminants into fractured basalt, and potentially downward to the regional ground water, three boreholes (one vertical, one at 43 degrees, and one at 34 degrees from horizontal) were installed for environmental monitoring. The boreholes penetrate to depths ranging from approximately 9 to 82 m below the weir floor. The two angled boreholes are fitted with flexible FLUTe liners with resistance sensors to measure relative moisture content and absorbent sampling pads for contaminant and environmental tracer sampling within the vadose zone. The two angled boreholes are also monitored for relative changes in moisture content by neutron logging. The vertical borehole penetrates three perched water zones and is equipped with four screens and sampling ports. In April 2002, a tracer test was initiated with the application of a 0.2 M (16,000 ppm) solution of potassium bromide (KBr) onto the weir floor. The tracer experiment was intended to provide data on travel times through the complex hydrogeologic media of fractured basalt. A precipitation and runoff event in June 2002 resulted in approximately 0.61 m of standing water behind the weir. If the KBr and flood waters were well mixed, the concentration of KBr in the flood waters was approximately 24 ppm. Bromide was detected in the absorbent membrane in the 43 degree hole at concentrations up to 2 ppm. Resistance sensors in the 43 degree borehole detected moisture increases within 3 days at a depth of 27 m, indicating an average wetting front velocity of 8.9 m per day in the vadose zone. Increases in bromide concentrations were detected in water samples from two of the four sampling ports in the vertical well within 10 days of the precipitation event, indicating an average wetting front velocity of 5.5 m per day to the sample port at a depth of 55 m below the weir floor. Increases in bromide concentrations were detected at the bottom port of the vertical well at a depth of 78 m below the weir floor within 21 days, indicating an average wetting front velocity of 3.7 m per day. Modeling of this tracer test data will improve our understanding of: the impact of the fire on ground-water quality; the impact of the weir on ground-water quality; surface water/ground water interactions; and the hydraulic properties of the Cerros del Rio basalts underlying the eastern Pajarito Plateau.

Centrifugal contactor modified for end stage operation in a multistage system

DOEpatents

Jubin, Robert T.

1990-01-01

A cascade formed of a plurality of centrifugal contactors useful for countercurrent solvent extraction processes such as utilizable for the reprocessing of nuclear reactor fuels is modified to permit operation in the event one or both end stages of the cascade become inoperative. Weir assemblies are connected to each of the two end stages by suitable conduits for separating liquids discharged from an inoperative end stage based upon the weight of the liquid phases uses in the solvent extraction process. The weir assembly at one end stage is constructed to separate and discharge the heaviest liquid phase while the weir assembly at the other end stage is constructed to separate and discharge the lightest liquid phase. These weir assemblies function to keep the liquid discharge from an inoperative end stages on the same weight phase a would occur from an operating end stage.

Experimental study to control the upstream migration of invasive alien fish species by submerged weir

NASA Astrophysics Data System (ADS)

Sakuma, Masami; Kunimatsu, Fumihiro; Tsuchiya, Taku; Kawamura, Makiko; Fujita, Hiroshi

Largemouth bass and Bluegill, major invasive alien fish species in Japan, have been extending their habitat ranges over not only Lake Biwa and the lagoons but also surrounding waters connected to them through small rivers and canals. Their increasing number is bringing about the reduction in the number of native fish species. To prevent the spread of these alien species through small rivers and canals during breeding season of the native fish (crucian carp), this study experimentally examined the effect of a submerged weir on controlling upstream migration of the alien species and the native fish. As a result of the experiment, the ratio of the alien species migrating upstream decreased as the weir height rose, whereas the ratio did not show the same trend in the case of the native fish. The ratio of the alien species also decreased as the overflow velocity over the weir rose. On the other hand, the ratio of the native fish increased as the overflow velocity rose up to 1.0m/s and decreased thereafter. These results suggest that the submerged weir may control upstream migration of the alien species to surrounding waters through small rivers and canals without interfering with the reproductive migration of the native fish.

4. EXTERIOR VIEW LOOKING EAST. WATER IN THE AQUEDUCT CAN ...

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

4. EXTERIOR VIEW LOOKING EAST. WATER IN THE AQUEDUCT CAN CAN BE DIVERTED AT THE WASTE WEIR TO BE DISCHARGED INTO THE CULVERT IN FOREGROUND. - Old Croton Aqueduct, Northern Waste Weir, Snowden Avenue & Van Wick Street, Ossining, Westchester County, NY

Hydrodynamic Regimes and Structures in Sloped Weir Baffled Culverts and Their Influence on Juvenile Salmon Passage.

DOT National Transportation Integrated Search

2007-07-01

The purpose of this study was to determine what hydraulic characteristics enhance or diminish : upstream juvenile salmon passage within a sloped-weir baffled culvert. The culvert slope, baffle : spacing, and baffle height were varied to observe flow ...

Biological Evaluations of an Off-Stream Channel, Horizontal Flat-Plate Fish Screen-The Farmers Screen

USGS Publications Warehouse

Mesa, Matthew G.; Rose, Brien P.; Copeland, Elizabeth S.

2010-01-01

Screens are commonly installed at water diversion sites to reduce entrainment of fish. Recently, the Farmers Irrigation District in Hood River, Oregon, developed a new flat-plate screen design that offers passive operation and may result in reduced operation and installation costs to irrigators. To evaluate the performance (its biological effect on fish) of this type of screen, two size classes of juvenile coho salmon (Oncorhynchus kistuch) were released over a small version of this screen in the field-the Herman Creek screen. The performance of the screen was evaluated over a range of inflow [0.02 to 0.42 m3/s (cubic meters per second)] and diversion flows (0.02 to 0.34 m3/s) at different weir wall heights. The mean approach velocities for the screen ranged from 0 to 5 cm/s (centimeters per second) and mean sweeping velocities ranged from 36 to 178 cm/s. Water depths over the screen surface ranged from 1 to 25 centimeters and were directly related to weir wall height and inflow. Passage of juvenile coho salmon over the screen under a variety of hydraulic conditions did not severely injure them or cause delayed mortality. For all fish, the mean percentage of body surface area that was injured after passage over the screen ranged from about 0.4 to 3.0%. This occurred even though many fish contacted the screen surface during passage. No fish were observed becoming impinged on the screen surface (greater than 1 second contact with the screen). When operated within its design criteria (diversion flows of about 0.28 m3/s), the screen provided safe and effective downstream passage of juvenile salmonids under a variety of hydraulic conditions. However, we do not recommend operating the screen at inflows less than 0.14 m3/s (5 ft3/s) because water depth can get quite shallow and the screen can completely dewater, particularly at very low flows.

Optimise inlet condition and design parameters of a new sewer overflow screening device using numerical model.

PubMed

Aziz, M A; Imteaz, M A; Huda, Nazmul; Naser, J

2014-01-01

After heavy rainfall, sewer overflow spills to receiving water bodies cause serious concern for the environment, aesthetics and public health. To overcome these problems this study investigated a new self-cleansing sewer overflow screening device. The device has a sewer overflow chamber, a rectangular tank and a slotted ogee weir to capture the gross pollutants. To design an efficient screening device a numerical computational fluid dynamic (CFD) model was used. A plausibility check of the CFD model was done using a one-dimensional analytical model. Results showed that an inlet parallel to the weir ensured better self-cleansing than an inlet perpendicular to the weir. Perforations should be at the bottom of the weir to get increased velocity and shear stress to create a favourable self-cleaning effect of the screening device. Increasing inlet length from 0.3 to 1.5 m reduced wave reflection up to 10%, which increased flow uniformity downstream and improved self-cleansing effect. The orientation of the ogee weir with the rectangular tank was found most uniform with a 1:3 (horizontal:vertical) slope. These results will help to maximise functional efficiency of the new sewer overflow screening device. Otherwise it would be too expensive to alter after installation and at times difficult to customise accordingly to existing urban drainage systems.

Predicting velocity in bendway weir eddy fields

Treesearch

Kristoph-Dietrich Kinzli; Christopher I. Thornton

2010-01-01

Rehabilitation of the Middle Rio Grande (MRG) in central New Mexico has become necessary because of changes in morphology resulting from the installation of dams, and because of habitat restoration considerations for the endangered Rio Grande silvery minnow (Hybognathus amarus). Bendway weirs are erosion control and channel-stabilization structures placed transverse to...

Functional characterization of two concrete biofilms using pyrosequencing data

EPA Science Inventory

Phylogenetic studies of concrete biofilms using 16SrRNA-based approaches have demonstrated that concrete surfaces harbor a diverse microbial community. These approaches can provide information on the general taxonomical groups present in a sample but cannot shed light on the func...

Apparatus for removing oil and other floating contaminants from a moving body of water

DOEpatents

Strohecker, J.W.

1973-12-18

The patent describes a process in which floating contaminants such as oil and solid debris are removed from a moving body of water by employing a skimming system which uses the natural gravitational flow of the water. A boom diagonally positioned across the body of water diverts the floating contaminants over a floating weir and into a retention pond where an underflow weir is used to return contaminant-free water to the moving body of water. The floating weir is ballasted to maintain the contaminant-receiving opening therein slightly below the surface of the water during fluctuations in the water level for skimming the contaminants with minimal water removal.

Bendway weirs: Could they create habitat for the endangered Rio Grande silvery minnow

Treesearch

Kristoph-Dietrich Kinzli; Christopher A. Myrick

2009-01-01

Rehabilitation of the Middle Rio Grande in central New Mexico has become necessary to mitigate the effects of over a century of water and land development. The primary driving force behind rehabilitation efforts is the federally endangered Rio Grande silvery minnow (Hybognathus amarus). Bendway weirs, erosion control and channel-stabilization...

The Weir: Storytelling that Transforms

ERIC Educational Resources Information Center

Karpiak, Irene E.

2008-01-01

Through the acts of telling our stories, writing our stories, and reading others' stories, we become known both to others and to ourselves. Drawing on the theme of transformation in the recent play "The Weir," this article explores the place of story in adult and continuing education and considers how story told by students can break…

Effects of low-grade weirs on soil microbial communities to advance agricultural best management practices for nitrate remediation

USDA-ARS?s Scientific Manuscript database

Agricultural activities throughout the Mississippi River Basin have been identified as a major source of nutrient pollution, particularly nitrogen from fertilizer application, to downstream waters including the Gulf of Mexico. Utilizing best management practices, such as low-grade weirs have been id...

Video evaluation of passage efficiency of American shad and sea lamprey in a modified Ice Harbor fishway

USGS Publications Warehouse

Haro, A.; Kynard, B.

1997-01-01

Movement and behavior of adult American shad Alosa sapidissima and sea lamprey Petromyzon marinus were monitored by closed-circuit video at several locations within a modified Ice Harbor fishway. American shad ascended and descended the fishway exclusively by surface weirs, while sea lampreys used both surface weirs and submerged orifices. Upstream movement of American shad during the day was higher than at night at both lower and middle fishway observation sites. Peak downstream movement of American shad at both locations was associated with decreasing light levels in the evening. Sea lampreys moved primarily at night at the lower and middle fishway sites. Mean daily passage efficiency was low (1% for American shad, -2% for sea lamprey) at the lower fishway surface weir, but passage efficiency at the middle fishway surface weir was moderate (70% for American shad, 35% for sea lamprey). High water velocity, air entrainment, and turbulence of the modified Ice Harbor fishway design appeared to inhibit American shad and sea lamprey passage by disrupting upstream migratory motivation and visual and rheotactic orientation.

10. CONCRETE DIVERSION CHANNEL EXTENDING TOWARD LAKE LADORA FROM THE ...

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

10. CONCRETE DIVERSION CHANNEL EXTENDING TOWARD LAKE LADORA FROM THE DIVERSION STRUCTURE WEST OF LOWER DERBY LAKE (SECTION 2). - Highline Canal, Sand Creek Lateral, Beginning at intersection of Peoria Street & Highline Canal in Arapahoe County (City of Aurora), Sand Creek lateral Extends 15 miles Northerly through Araphoe County, City & County of Denver, & Adams County to its end point, approximately 1/4 mile Southest of intersectioin of D Street & Ninth Avenue in Adams County (Rocky Mountain Arsenal, Commerce City Vicinity), Commerce City, Adams County, CO

Hydrologic description of the Braden River watershed, west-central Florida

USGS Publications Warehouse

DelCharco, M.J.; Lewelling, B.R.

1997-01-01

The Braden River watershed drains an 83-square mile area in west-central Florida and is the largest tributary to the Manatee River. The hydrology of the Braden River was altered in 1936 when the city of Bradenton created Ward Lake, a reservoir with an 838-foot broad-crested weir 6 miles upstream from the mouth. In 1985 the reservoir, which is the sole source of drinking water for the city of Bradenton, was expanded and supplies an annual average of 5.7 million gallons of water per day. The Braden River can be hydrologically divided into three distinct sections that include an 8.6-mile reach of naturally incised, free-flowing channel; a 6.4-mile reach of impounded river created by the Ward Lake reservoir and weir; and a 6-mile reach of tidal estuary. Ten first-order and two second-order tributaries that flow into the Braden River were examined in this report. The Braden River watershed is dominated by low topographic relief. The two physiographic zones that contain the Braden River watershed, the Gulf Coast Lowlands and De Soto Plain, are both poorly drained and have numerous depressional features. The climate is subtropical with an annual average rainfall of 56 inches, annual average temperatures of 72 degrees Fahrenheit, and estimated annual lake evaporation of 52 inches. The soil series in the watershed are predominantly Myakka-Cassia and the EauGallie-Floridana; these series are characterized as nearly level and poorly drained soils. Land use within the watershed is the fastest changing characteristic that affects the hydrology of the system. The western half of the watershed is typically urban and includes parts of the city of Bradenton. Land use in the eastern half of the watershed is predominantly agricultural, but the explosive population growth of the area is driving the development of medium to high-density residential communities. The three major aquifers underlying the Braden River watershed are the surficial, intermediate, and Floridan aquifer systems. The surficial aquifer generally is underlain in places by a clay layer that enhances the ground-water flow of the surficial aquifer to surface-water bodies. The intermediate aquifer system has discontinuous water-bearing units, but retards ground-water movement between the surficial and Floridan aquifer system. The Floridan aquifer system consists of the Upper and Lower Floridan aquifers separated by a middle confining unit. The Upper Floridan aquifer is the primary source for ground-water withdrawals in the watershed and has, at times, heads 20 feet higher than land-surface elevation. Discharge over the Ward Lake weir into the tidal estuary was measured using volumetric and standard discharge measurement techniques. Annual mean flow for water years 1993 and 1994 were 59.7 and 57.3 cubic feet per second, respectively. Weir coefficients, calculated from discharge measurements, ranged from 0.023 to 2.99, depending on the head of water over the weir, and the method of determining length of flow on the weir. Weir coefficients calculated from the theoretical rating ranged from 0.032 to 3.11. No significant seepage was found around the ends of the weir, and no leakage was detected through the weir.

Analysis of a hydraulic a scaled asymmetric labyrinth weir with Ansys-Fluent

NASA Astrophysics Data System (ADS)

Otálora Carmona, Andrés Humberto; Santos Granados, Germán Ricardo

2017-04-01

This document presents the three dimensional computational modeling of a labyrinth weir, using the version 17.0 of the Computational Fluid Dynamics (CFD) software ANSYS - FLUENT. The computational characteristics of the model such as the geometry consideration, the mesh sensitivity, the numerical scheme, and the turbulence modeling parameters. The volume fraction of the water mixture - air, the velocity profile, the jet trajectory, the discharge coefficient and the velocity field are analyzed. With the purpose of evaluating the hydraulic behavior of the labyrinth weir of the Naveta's hydroelectric, in Apulo - Cundinamarca, was development a 1:21 scale model of the original structure, which was tested in the laboratory of the hydraulic studies in the Escuela Colombiana de Ingeniería Julio Garavito. The scale model of the structure was initially developed to determine the variability of the discharge coefficient with respect to the flow rate and their influence on the water level. It was elaborate because the original weir (labyrinth weir with not symmetrical rectangular section), did not have the capacity to work with the design flow of 31 m3/s, because over 15 m3/s, there were overflows in the adduction channel. This variation of efficiency was due to the thickening of the lateral walls by structural requirements. During the physical modeling doing by Rodríguez, H. and Matamoros H. (2015) in the test channel, it was found that, with the increase in the width of the side walls, the discharge coefficient is reduced an average by 34%, generating an increase of the water level by 0.26 m above the structure. This document aims to develop a splicing methodology between the physical models of a labyrinth weir and numerical modeling, using concepts of computational fluid dynamics and finite volume theories. For this, was carried out a detailed analysis of the variations in the different directions of the main hydraulic variables involved in the behavior, such as, the components of the velocity and the distribution of pressures, For the numerical development, we worked with ANSYS - FLUENT software modeling version 17.0. Initially, a digital model of a conventional triangular weir with a vertical angle of 102° was developed in order to find the most appropriate numerical scheme and conditions. The numerical results were compared with conventional theories, evaluating the path and discharge coefficient. Subsequently, one of the five cycles that compose the labyrinth weir was simulated, evaluating the behavior of the discharge coefficient, the water level, the streamline and the velocity field, with the purpose of understanding the hydraulic variables that are related in these geometries. According to the previous results, the numerical modeling of labyrinth weir was performed, comparing the obtained results with the data of the physical scale model, analyzing the variation of the discharge coefficient, the streamline, velocity field, pressure distribution and shear stress. Finally, based on the lessons learned from physical and numerical modeling, a methodological guide was created for any user with a computational and hydraulic fluid mechanics knowledge to develop a good practice of a computational and physical modeling.

Design of an Orifice and Weir Outlet for Poorly Drained Forested Watersheds

Treesearch

D.M. Amatya; R.W. Skaggs; J.H. Hughes

1999-01-01

Orifice-weir structures at ditch outlets are being used to reduce peak drainage rates and to store water during the growing season in poorly drained managed pine plantations. Earlier studies have shown their effectiveness on reducing drainage outflows while conserving water during the growing season. This study reports on criteria and preliminary guidelines for...

A cell sorting and trapping microfluidic device with an interdigital channel

NASA Astrophysics Data System (ADS)

Tu, Jing; Qiao, Yi; Xu, Minghua; Li, Junji; Liang, Fupeng; Duan, Mengqin; Ju, An; Lu, Zuhong

2016-12-01

The growing interest in cell sorting and trapping is driving the demand for high performance technologies. Using labeling techniques or external forces, cells can be identified by a series of methods. However, all of these methods require complicated systems with expensive devices. Based on inherent differences in cellular morphology, cells can be sorted by specific structures in microfluidic devices. The weir filter is a basic and efficient cell sorting and trapping structure. However, in some existing weir devices, because of cell deformability and high flow velocity in gaps, trapped cells may become stuck or even pass through the gaps. Here, we designed and fabricated a microfluidic device with interdigital channels for cell sorting and trapping. The chip consisted of a sheet of silicone elastomer polydimethylsiloxane and a sheet of glass. A square-wave-like weir was designed in the middle of the channel, comprising the interdigital channels. The square-wave pattern extended the weir length by three times with the channel width remaining constant. Compared with a straight weir, this structure exhibited a notably higher trapping capacity. Interdigital channels provided more space to slow down the rate of the pressure decrease, which prevented the cells from becoming stuck in the gaps. Sorting a mixture K562 and blood cells to trap cells demonstrated the efficiency of the chip with the interdigital channel to sort and trap large and less deformable cells. With stable and efficient cell sorting and trapping abilities, the chip with an interdigital channel may be widely applied in scientific research fields.

Evaluation of juvenile salmonid behavior near a prototype weir box at Cowlitz Falls Dam, Washington, 2013

USGS Publications Warehouse

Kock, Tobias J.; Liedtke, Theresa L.; Ekstrom, Brian K.; Tomka, Ryan G.; Rondorf, Dennis W.

2014-01-01

Collection of juvenile salmonids at Cowlitz Falls Dam is a critical part of the effort to restore salmon in the upper Cowlitz River because the majority of fish that are not collected at the dam pass downstream and enter a large reservoir where they become landlocked and lost to the anadromous fish population. However, the juvenile fish collection system at Cowlitz Falls Dam has failed to achieve annual collection goals since it first began operating in 1996. Since that time, numerous modifications to the fish collection system have been made and several prototype collection structures have been developed and tested, but these efforts have not substantially increased juvenile fish collection. Studies have shown that juvenile steelhead (Oncorhynchus mykiss), coho salmon (Oncorhynchus kisutch), and Chinook salmon (Oncorhynchus tshawytscha) tend to locate the collection entrances effectively, but many of these fish are not collected and eventually pass the dam through turbines or spillways. Tacoma Power developed a prototype weir box in 2009 to increase capture rates of juvenile salmonids at the collection entrances, and this device proved to be successful at retaining those fish that entered the weir. However, because of safety concerns at the dam, the weir box could not be deployed near a spillway gate where the prototype was tested, so the device was altered and re-deployed at a different location, where it was evaluated during 2013. The U.S. Geological Survey conducted an evaluation using radiotelemetry to monitor fish behavior near the weir box and collection flumes. The evaluation was conducted during April–June 2013. Juvenile steelhead and coho salmon (45 per species) were tagged with a radio transmitter and passive integrated transponder (PIT) tag, and released upstream of the dam. All tagged fish moved downstream and entered the forebay of Cowlitz Falls Dam. Median travel times from the release site to the forebay were 0.8 d for steelhead and 1.2 d for coho salmon. Most fish spent several days in the dam forebay; median forebay residence times were 4.4 d for juvenile steelhead and 5.7 d for juvenile coho salmon. A new radio transmitter model was used during the study period. The transmitter had low detection probabilities on underwater antennas located within the collection system, which prevented us from reporting performance metrics (discovery efficiency, entrance efficiency, retention efficiency) that are traditionally used to evaluate fish collection systems. Most tagged steelhead (98 percent) and coho salmon (84 percent) were detected near the weir box or collection flume entrances during the study period; 39 percent of tagged steelhead and 55 percent of tagged coho salmon were detected at both entrances. Sixty-three percent of the tagged steelhead that were detected at both entrances were first detected at the weir box, compared to 52 percent of the coho salmon. Twelve steelhead and 15 coho salmon detected inside the weir box eventually left the device and were collected in collection flumes or passed the dam. Overall, collection rates were relatively high during the study period. Sixty-five percent of the steelhead and 80 percent of the coho salmon were collected during the study, and most of the remaining fish passed the dam and entered the tailrace (24 percent of steelhead; 13 percent of coho salmon). The remaining 11 percent of steelhead and 7 percent of coho salmon did not pass the dam while their transmitters were operating. We were able to confirm collection of tagged fish at the fish facility using three approaches: (1) detection of radio transmitters in study fish; (2) detection of PIT-tags in study fish; (3) observation of study fish by staff at the fish facility. Data from all three methods were used to develop a multistate mark-recapture model that estimated detection probabilities for the various monitoring methods. These estimates then were used to describe the percent of tagged fish that were collected through the weir box and collection flumes. Detection probabilities of PIT-tag antennas in the collection flumes were 0.895 for juvenile steelhead and 0.881 for juvenile coho salmon, although radiotelemetry detection probabilities were 0.654 and 0.646 for the two species, respectively. The multistate model estimates showed that all steelhead and most coho salmon (94.5 percent) that were collected at the dam entered the collection system through the flumes rather than through the weir box. None of the tagged steelhead and only 5.5 percent of the tagged coho salmon were collected through the weir box. These data show that juvenile steelhead and coho salmon collection rates were much higher through the collection flumes than through the weir box. Low detection probabilities of tagged fish in the fish collection system resulted in uncertainty for some aspects of our evaluation. Missing detection records within the collection system for fish that were known to have been collected resulted in four tagged steelhead and seven tagged coho salmon being removed from the dataset, which was used to assess discovery rates of the weir box and collection flumes. However, the multistate model allowed us to provide unbiased estimates of the percentage of tagged fish that were collected through each route, and these data showed that few fish were collected through the weir box. Overall, the fish collection system performed reasonably well in collecting juvenile steelhead and coho salmon during the 2013 collection season. Fish collection efficiency estimates from the Washington Department of Fish and Wildlife showed that steelhead collection efficiency was slightly higher than the 10-year average (46 percent compared to 42 percent), whereas coho salmon collection efficiency was more than twice as high as the 10-year average (63 percent compared to 30 percent). However, the performance of the weir box was poor because most fish were collected through the collection flumes.

Spawning demographics and juvenile dispersal of an adfluvial bull trout population in Trestle Creek, Idaho

Treesearch

Christopher C. Downs; Dona Horan; Erin Morgan-Harris; Robert Jakubowski

2006-01-01

We utilized a screw trap, trap-box weir, remote passive integrated transponder tag (PIT) detection weir, and otolith microchemistry to evaluate (2000–2004) spawning demographics and migration patterns of adfluvial bull trout Salvelinus confluentus in Trestle Creek, Idaho, a tributary to Lake Pend Oreille. Annual repeat spawning was more common than...

Hydraulic transients in the long diversion-type hydropower station with a complex differential surge tank.

PubMed

Yu, Xiaodong; Zhang, Jian; Zhou, Ling

2014-01-01

Based on the theory of hydraulic transients and the method of characteristics (MOC), a mathematic model of the differential surge tank with pressure-reduction orifices (PROs) and overflow weirs for transient calculation is proposed. The numerical model of hydraulic transients is established using the data of a practical hydropower station; and the probable transients are simulated. The results show that successive load rejection is critical for calculating the maximum pressure in spiral case and the maximum rotating speed of runner when the bifurcated pipe is converging under the surge tank in a diversion-type hydropower station; the pressure difference between two sides of breast wall is large during transient conditions, and it would be more serious when simultaneous load rejections happen after load acceptance; the reasonable arrangement of PROs on breast wall can effectively decrease the pressure difference.

Hydraulic Transients in the Long Diversion-Type Hydropower Station with a Complex Differential Surge Tank

PubMed Central

Yu, Xiaodong; Zhang, Jian

2014-01-01

Based on the theory of hydraulic transients and the method of characteristics (MOC), a mathematic model of the differential surge tank with pressure-reduction orifices (PROs) and overflow weirs for transient calculation is proposed. The numerical model of hydraulic transients is established using the data of a practical hydropower station; and the probable transients are simulated. The results show that successive load rejection is critical for calculating the maximum pressure in spiral case and the maximum rotating speed of runner when the bifurcated pipe is converging under the surge tank in a diversion-type hydropower station; the pressure difference between two sides of breast wall is large during transient conditions, and it would be more serious when simultaneous load rejections happen after load acceptance; the reasonable arrangement of PROs on breast wall can effectively decrease the pressure difference. PMID:25133213

A simulation method for combining hydrodynamic data and acoustic tag tracks to predict the entrainment of juvenile salmonids onto the Yolo Bypass under future engineering scenarios

USGS Publications Warehouse

Blake, Aaron R.; Stumpner, Paul; Burau, Jon R.

2017-01-01

During water year 2016 the U.S. Geological Survey California Water Science Center (USGS) collaborated with the California Department of Water Resources (DWR) to conduct a joint hydrodynamic and fisheries study to acquire data that could be used to evaluate the effects of proposed modifications to the Fremont Weir on outmigrating juvenile Chinook salmon. During this study the USGS surgically implanted acoustic tags in juvenile late fall run Chinook salmon from the Coleman National Fish Hatchery, released the acoustically tagged juvenile salmon into the Sacramento River upstream of the Fremont Weir, and tracked their movements as they emigrated past the western end of the Fremont Weir.The USGS analyzed tracking data from the acoustically tagged juvenile salmon along with detailed hydrodynamic data collected in the Sacramento River during the winter/spring of water year 2016 in the vicinity of the western end of the Fremont Weir to assess the potential for enhancing the entrainment of Sacramento River Chinook salmon onto the Yolo Bypass under six different Fremont Weir modification scenarios. Each modification scenario consists of a notch or multiple notches in the Fremont Weir which are designed to divert a portion of the Sacramento River onto the Yolo Bypass when the Sacramento River is below the crest of the Fremont Weir. The primary goal of this entrainment analysis was to investigate how the location of the notch or notches in each scenario affected the entrainment of juvenile Chinook salmon onto the Yolo Bypass, and to predict the notch location or locations that would result in maximum entrainment under each modification scenario. Stumpner et al.’s (in review) analysis of hydraulic data collected during the 2016 study period showed that backwater effects in the Sacramento River created significant variability in the relationship between Sacramento River stage and the proportion of the Sacramento River flow that we expect to be diverted onto the Yolo Bypass under the modification scenarios. Because of this variability, accurately evaluating the entrainment potential of possible notch locations for each scenario required combining historic abundance data for juvenile Sacramento River Chinook salmon with historic hydraulic data for the Sacramento River in the vicinity of the Fremont Weir, so that the entrainment estimates would reflect the covariance between Sacramento River stage, Sacramento River discharge, and juvenile salmon abundance within the historic record.We used a Monte Carlo simulation framework to combine the high resolution hydrodynamic data and acoustic tag track data collected in 2016 with historic juvenile salmon abundance, Sacramento River stage, and Sacramento River discharge data from a period spanning water years 1996-2010 to assess the entrainment potential of different weir modification scenarios under historic conditions. The scenarios we simulated consisted of four single notch configurations, and two multiple notch configurations in the vicinity of the western end of the Fremont Weir. For each notch configuration the 15-water-year entrainment simulation was repeated for 63 possible notch locations in the vicinity of the western end of the Fremont Weir. This approach allowed us to assess the effect of notch location on the entrainment of juvenile salmonids onto the Yolo Bypass for each of the six notch configurations that we evaluated.The entrainment simulations showed that the location of each notch configuration had a major impact on the entrainment for each scenario; the predicted entrainment of some scenarios varied by as much as 400% based on where the notch (or notches) was (were) located in the study area. All of the single notch scenarios performed best when they were located within a 330 ft (100 meter) long section of the Sacramento River bank adjacent to the western terminus of the Fremont Weir (Table 1). Both of the multiple notch scenarios performed best when their upstream notches were located about 660 ft (200 meters) upstream of the western terminus of the Fremont Weir (Table 1). The results of the entrainment simulations indicated that for each notch configuration the same notch location produced near-maximum entrainment regardless of run abundance timing; this result suggests that there are areas within the study are where a notch (or notches) can be sited to achieve maximum entrainment for all runs (barring significant behavioral or physiological differences between runs). In addition, the simulation results indicate that for each notch configuration the same location is expected to produce nearmaximum entrainment for both wet water years and dry water years.Based on the results of the entrainment simulation we make three general recommendations for strategies to improve the entrainment potential of a notch in the Fremont Weir:1) Comparisons between the maximum entrainment potential for each scenario suggested that total entrainment of winter run, spring run, and fall run salmon onto the Yolo Bypass can be increased by increasing the amount of water entering a notch when the Sacramento River stage is between 19 ft and 22 ft NAVD88; this could be accomplished by lowering notch invert elevations or by adding a control section to the Sacramento River to raise stage for a given discharge.2) The relationship between Sacramento River stage and entrainment for each scenario indicated that entrainment efficiency for each scenario declined significantly once Sacramento River stage exceeded bankfull (approximately 28.5 ft NAVD88). This effect was likely due to inundation of the floodplain between the Sacramento River and the Fremont Weir; Stumpner et. al (In Review) have documented a reduction in the strength of the secondary circulation and centralization of the downwelling zone in the Sacramento River when this floodplain is inundated. Therefore, increasing the height of the river right bank of the Sacramento River to coincide with the height of the Fremont Weir is recommended to increase entrainment at higher stages. 3) Bathymetric features upstream of notch openings appeared to have a major impact on the entrainment potential of the simulated notches. For this reason we recommend taking care to avoid siting notches immediately downstream of bank features that alter the sidewall boundary layer, and we expect that smoothing the bank bathymetry upstream of a notch will enhance entrainment. Finally, we caution that the entrainment simulation was based on the behavior of large hatchery smolts, so it is likely that our results will be sensitive to any differences in behavior and physiology between these hatchery surrogates and naturally migrating juvenile salmon.

Marine Biotechnology. Basic Research Relevant to Biomaterials and Biosensors

DTIC Science & Technology

1985-01-01

forces (the syringe effect ). Their electronic states and luminescence are other properties with potential for practical application (Callis, 1983). The...based on agglutination (Weir and Herbert, 1973), on fluorescence (Weir et al., 1973), or on other optical effects (Giaever et al., 1984). Several...time (Lowe, 1984). For example, it is possible to couple the reacting moleculea directly to the gate of aj metal oxide semiconducting field- effect

Supplement Analysis for the Grande Ronde Basin Endemic Spring Chinook Salmon Supplementation Program EA (DOE/EA-1173/SA-01)

DOE Office of Scientific and Technical Information (OSTI.GOV)

N /A

2003-12-18

The CTUIR and ODFW propose to expand their monitoring and evaluation for the Grande Ronde spring chinook supplementation program to take additional data on summer steelhead that are trapped at the existing adult collection weirs on the upper Grande Ronde River and Catherine Creek. The weirs are a movable design and are operated seasonally during the adult chinook migration. Bull trout and summer steelhead have been trapped at the weirs since 1997 incidental to the spring chinook broodstock collection activities. Minimal data is recorded on both species as a requirement of the ESA permits, and reported to USFWS and NOAAmore » Fisheries. This supplement analysis covers a minor expansion of the program to collect more extensive life history data on summer steelhead. The weir and trap will be installed 2-3 weeks earlier (early to mid-March) than was previously needed for the spring chinook broodstock collection in order to monitor the summer steelhead migration period. The adult steelhead will be captured in the traps, anesthetized, and measured. Data will be recorded on the date of capture, fork length, sex, markings, and maturity of the fish, and scale and punch tissue samples will be taken for genetic analyses.« less

Department of Clinical Investigation Annual Research Progress Report, Fiscal Year 1989

DTIC Science & Technology

1989-09-30

and DES. Patients with a history of deep vein thrombosis, cerebral embolus, stroke , congestive heart failure, or ischemic heart disease will not be...Adolescent Health Care 9(6): 498-500, 1988 Weir MR Intravascular Injuries from Intramuscular Penicillin. Clinical Pediatrics 27(2): 85-90, 1988 Weir...Military Medicine 154(9): 455-57, 1989 Piatt JH, Goodkin R Barbiturates in Severe Head Injury . J Neurosurgery 70(3): 501-02, 1989 * Piatt JH

Method and apparatus for improved melt flow during continuous strip casting

DOEpatents

Follstaedt, Donald W.; King, Edward L.; Schneider, Ken C.

1991-11-12

The continuous casting of metal strip using the melt overflow process is improved by controlling the weir conditions in the nozzle to provide a more uniform flow of molten metal across the width of the nozzle and reducing the tendency for freezing of metal along the interface with refractory surfaces. A weir design having a sloped rear wall and tapered sidewalls and critical gap controls beneath the weir has resulted in the drastic reduction in edge tearing and a significant improvement in strip uniformity. The floor of the container vessel is preferably sloped and the gap between the nozzle and the rotating substrate is critically controlled. The resulting flow patterns observed with the improved casting process have reduced thermal gradients in the bath, contained surface slag and eliminated undesirable solidification near the discharge area by increasing the flow rates at those points.

Method and apparatus for improved melt flow during continuous strip casting

DOEpatents

Follstaedt, D.W.; King, E.L.; Schneider, K.C.

1991-11-12

The continuous casting of metal strip using the melt overflow process is improved by controlling the weir conditions in the nozzle to provide a more uniform flow of molten metal across the width of the nozzle and reducing the tendency for freezing of metal along the interface with refractory surfaces. A weir design having a sloped rear wall and tapered sidewalls and critical gap controls beneath the weir has resulted in the drastic reduction in edge tearing and a significant improvement in strip uniformity. The floor of the container vessel is preferably sloped and the gap between the nozzle and the rotating substrate is critically controlled. The resulting flow patterns observed with the improved casting process have reduced thermal gradients in the bath, contained surface slag and eliminated undesirable solidification near the discharge area by increasing the flow rates at those points. 8 figures.

The potential impact of green agendas on historic river landscapes: Numerical modelling of multiple weir removal in the Derwent Valley Mills world heritage site, UK

NASA Astrophysics Data System (ADS)

Howard, A. J.; Coulthard, T. J.; Knight, D.

2017-09-01

The exploitation of river systems for power and navigation has commonly been achieved through the installation of a variety of in-channel obstacles of which weirs in Britain are amongst the most common. In the UK, the historic value of many of these features is recognised by planning designations and protection more commonly associated with historic buildings and other major monuments. Their construction, particularly in the north and west of Britain, has often been associated with industries such as textiles, chemicals, and mining, which have polluted waterways with heavy metals and other contaminants. The construction of weirs altered local channel gradients resulting in sedimentation upstream with the potential as well for elevated levels of contamination in sediments deposited there. For centuries these weirs have remained largely undisturbed, but as a result of the growth in hydropower and the drive to improve water quality under the European Union's Water Framework Directive, these structures are under increasing pressure to be modified or removed altogether. At present, weir modifications appear to be considered largely on an individual basis, with little focus on the wider impacts this might have on valley floor environments. Using a numerical modelling approach, this paper simulates the removal of major weirs along a 24-km stretch of the river Derwent, Derbyshire, UK, designated as a UNESCO World Heritage Site. The results suggest that although removal would not result in significant changes to the valley morphology, localised erosion would occur upstream of structures as the river readjusts its base level to new boundary conditions. Modelling indicates that sediment would also be evacuated away from the study area. In the context of the Derwent valley, this raises the potential for the remobilisation of contaminants (legacy sediments) within the wider floodplain system, which could have detrimental, long-term health and environmental implications for the river system. Worldwide, rivers have a common association with industry - being the focus of settlement and development since the earliest civilisations with channel engineering a common practice. Therefore, the conceptual issues raised by this study have global resonance and are particularly important where heritage protection is less robust and structures can be removed with little consideration of the environmental consequences.

New Standard Weir Design for Dredged Material Management Area, Jacksonville District

DTIC Science & Technology

2014-08-01

dock access, Bartram Island Cell B2, Jacksonville, Florida. Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for...Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 ERDC/TN DOTS-14-01 August 2014 2 US Army Corps of Engineers • Engineer Research...and through the riser stack of weir boards. This requires secondary sealing measures in the form of plastic sheeting, geotextiles, and/or burlap

Comparison of Ecological Impacts of Postulated Oil Spills at Selected Alaskan Locations. Volume 1. Introduction, Summary, Methodology, Evaluation and Appendices

DTIC Science & Technology

1975-06-01

MECHANISM : ALUMINOSILICATE ORGANIC INTERACTION IN SALINE WATERS, A.C.S. Tom M 21 (1969-1970) to be published in Advances in Chemistry Series. 5...recovery mechanisms . Detailed information on various devices is given in Sittig3 and by EPA. (1) WEIR DEVICES Weir devices depend on gravity to... mechanical eguipments. The selection depends on the depth of oil penetration: 1. For oil penetration of up to 1 inch, combined use of road graders and

The Separation of Southern Sudan: A Possible American Response

DTIC Science & Technology

2011-03-11

missions/unmis/facts.shtml. 40 48 Erin Weir and Vanessa Parra,_ "Sudan: UNMIS Must be More Proactive in Protecting Civilians," Refugees International...December 13,2010, http://uk.reuters.com/article/idUKTRE6BC4EE20101213 (accessed December 28, 2010). 52 J air van der Lijn, "To Paint the Nile Blue...has had to be replaced by the UN in two of its first three attempts. (Burundi and Sudan) Weir, Erin and Parra, Vanessa . "Sudan: Ul\\TMIS Must be

The Average Network Flow Problem: Shortest Path and Minimum Cost Flow Formulations, Algorithms, Heuristics, and Complexity

DTIC Science & Technology

2012-09-13

Jordan, Captain, USAF AFIT/DS/ENS/12-09 DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY AIR FORCE INSTITUTE OF TECHNOLOGY Wright- Patterson Air Force Base...Way, Wright- Patterson AFB, Ohio, 45433, USA, +1 937-255-3636, jeremy.jordan@afit.edu jeffery.weir@afit.edu doral.sandlin@afit.edu 1.1 Abstract United...Technology 2950 Hobson Way, Wright- Patterson AFB, Ohio, 45433, USA, +1 937-255-3636, jeremy.jordan@afit.edu jeffery.weir@afit.edu doral.sandlin@afit.edu

High-Resolution Microbial Community Succession of Microbially Induced Concrete Corrosion in Working Sanitary Manholes

PubMed Central

Ling, Alison L.; Robertson, Charles E.; Harris, J. Kirk; Frank, Daniel N.; Kotter, Cassandra V.; Stevens, Mark J.; Pace, Norman R.; Hernandez, Mark T.

2015-01-01

Microbially-induced concrete corrosion in headspaces threatens wastewater infrastructure worldwide. Models for predicting corrosion rates in sewer pipe networks rely largely on information from culture-based investigations. In this study, the succession of microbes associated with corroding concrete was characterized over a one-year monitoring campaign using rRNA sequence-based phylogenetic methods. New concrete specimens were exposed in two highly corrosive manholes (high concentrations of hydrogen sulfide and carbon dioxide gas) on the Colorado Front Range for up to a year. Community succession on corroding surfaces was assessed using Illumina MiSeq sequencing of 16S bacterial rRNA amplicons and Sanger sequencing of 16S universal rRNA clones. Microbial communities associated with corrosion fronts presented distinct succession patterns which converged to markedly low α-diversity levels (< 10 taxa) in conjunction with decreasing pH. The microbial community succession pattern observed in this study agreed with culture-based models that implicate acidophilic sulfur-oxidizer Acidithiobacillus spp. in advanced communities, with two notable exceptions. Early communities exposed to alkaline surface pH presented relatively high α-diversity, including heterotrophic, nitrogen-fixing, and sulfur-oxidizing genera, and one community exposed to neutral surface pH presented a diverse transition community comprised of less than 20% sulfur-oxidizers. PMID:25748024

High-resolution microbial community succession of microbially induced concrete corrosion in working sanitary manholes.

PubMed

Ling, Alison L; Robertson, Charles E; Harris, J Kirk; Frank, Daniel N; Kotter, Cassandra V; Stevens, Mark J; Pace, Norman R; Hernandez, Mark T

2015-01-01

Microbially-induced concrete corrosion in headspaces threatens wastewater infrastructure worldwide. Models for predicting corrosion rates in sewer pipe networks rely largely on information from culture-based investigations. In this study, the succession of microbes associated with corroding concrete was characterized over a one-year monitoring campaign using rRNA sequence-based phylogenetic methods. New concrete specimens were exposed in two highly corrosive manholes (high concentrations of hydrogen sulfide and carbon dioxide gas) on the Colorado Front Range for up to a year. Community succession on corroding surfaces was assessed using Illumina MiSeq sequencing of 16S bacterial rRNA amplicons and Sanger sequencing of 16S universal rRNA clones. Microbial communities associated with corrosion fronts presented distinct succession patterns which converged to markedly low α-diversity levels (< 10 taxa) in conjunction with decreasing pH. The microbial community succession pattern observed in this study agreed with culture-based models that implicate acidophilic sulfur-oxidizer Acidithiobacillus spp. in advanced communities, with two notable exceptions. Early communities exposed to alkaline surface pH presented relatively high α-diversity, including heterotrophic, nitrogen-fixing, and sulfur-oxidizing genera, and one community exposed to neutral surface pH presented a diverse transition community comprised of less than 20% sulfur-oxidizers.

28. CONCRETE DIVERSION STRUCTURE ON THE WEST SIDE OF D ...

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

28. CONCRETE DIVERSION STRUCTURE ON THE WEST SIDE OF D STREET ABOUT ONE-QUARTER MILE SOUTH OF 9TH AVNEUE (SECTION 26); THE LATERAL CONTINUES NORTHEAST WHILE A SIDE DITCH PROCEEDS NORTHWARD. THE DIVERSION STRUCTURE SHOWN IN CO-43-A-27 IS VISIBLE IN THE DISTANCE. - Highline Canal, Sand Creek Lateral, Beginning at intersection of Peoria Street & Highline Canal in Arapahoe County (City of Aurora), Sand Creek lateral Extends 15 miles Northerly through Araphoe County, City & County of Denver, & Adams County to its end point, approximately 1/4 mile Southest of intersectioin of D Street & Ninth Avenue in Adams County (Rocky Mountain Arsenal, Commerce City Vicinity), Commerce City, Adams County, CO

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

NASA Astrophysics Data System (ADS)

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

2005-05-01

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

Maintenance action readiness assessment plan for White Oak Creek and Melton Branch Weir Stilling Pool cleanout at Oak Ridge National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-08-01

This Readiness Assessment Plan has been prepared to document operational readiness for the following maintenance action: (1) removal of sediment from the White Oak Creek and Melton Branch Weir Stilling Pools and (2) disposal of the radiologically contaminated sediment in another location upstream of the weirs in an area previously contaminated by stream overflow from Melton Branch in Waste Area Grouping 2 (WAG) at Oak Ridge National Laboratory. This project is being performed as a maintenance action rather than an action under the Comprehensive Environmental Response, Compensation, and Liability Act because the risk to human health and environment is wellmore » below the US Environmental Protection Agency`s level of concern. The decision to proceed as a maintenance action was documented by an interim action proposed plan, which is included in the administrative record. The administrative record is available for review at the US Department of Energy Information Resource Center, 105 Broadway Avenue, Oak Ridge, Tennessee 37830.« less

Modeling carbon dioxide, pH, and un-ionized ammonia relationships in serial reuse systems

USGS Publications Warehouse

Colt, J.; Watten, B.; Rust, M.

2009-01-01

In serial reuse systems, excretion of metabolic carbon dioxide has a significant impact on ambient pH, carbon dioxide, and un-ionized ammonia concentrations. This impact depends strongly on alkalinity, water flow rate, feeding rate, and loss of carbon dioxide to the atmosphere. A reduction in pH from metabolic carbon dioxide can significantly reduce the un-ionized ammonia concentration and increase the carbon dioxide concentrations compared to those parameters computed from influent pH. The ability to accurately predict pH in serial reuse systems is critical to their design and effective operation. A trial and error solution to the alkalinity-pH system was used to estimate important water quality parameters in serial reuse systems. Transfer of oxygen and carbon dioxide across the air-water interface, at overflow weirs, and impacts of substrate-attached algae and suspended bacteria were modeled. Gas transfer at the weirs was much greater than transfer across the air-water boundary. This simulation model can rapidly estimate influent and effluent concentrations of dissolved oxygen, carbon dioxide, and un-ionized ammonia as a function of water temperature, elevation, water flow, and weir type. The accuracy of the estimates strongly depends on assumed pollutional loading rates and gas transfer at the weirs. The current simulation model is based on mean daily loading rates; the impacts of daily variation loading rates are discussed. Copies of the source code and executable program are available free of charge.

Modeling Carbon Dioxide, pH and Un-Ionized Ammonia Relationships in Serial Reuse Systems

USGS Publications Warehouse

Watten, Barnaby J.; Rust, Michael; Colt, John

2009-01-01

In serial reuse systems, excretion of metabolic carbon dioxide has a significant impact on ambient pH, carbon dioxide, and un-ionized ammonia concentrations. This impact depends strongly on alkalinity, water flow rate, feeding rate, and loss of carbon dioxide to the atmosphere. A reduction in pH from metabolic carbon dioxide can significantly reduce the un-ionized ammonia concentration and increase the carbon dioxide concentrations compared to those parameters computed from influent pH. The ability to accurately predict pH in serial reuse systems is critical to their design and effective operation. A trial and error solution to the alkalinity–pH system was used to estimate important water quality parameters in serial reuse systems. Transfer of oxygen and carbon dioxide across the air–water interface, at overflow weirs, and impacts of substrate-attached algae and suspended bacteria were modeled. Gas transfer at the weirs was much greater than transfer across the air–water boundary. This simulation model can rapidly estimate influent and effluent concentrations of dissolved oxygen, carbon dioxide, and un-ionized ammonia as a function of water temperature, elevation, water flow, and weir type. The accuracy of the estimates strongly depends on assumed pollutional loading rates and gas transfer at the weirs. The current simulation model is based on mean daily loading rates; the impacts of daily variation loading rates are discussed. Copies of the source code and executable program are available free of charge.

Diversity Digest. Volume 9, Number 1

ERIC Educational Resources Information Center

Musil, Caryn McTighe, Ed.; Hovland, Kevin, Ed.

2005-01-01

Civic engagement is the focus of this issue of "Diversity Digest." Concrete examples of institutions that have linked diversity and civic engagement in powerful, effective, and educationally transforming ways are presented. What is seen in the field is encouraging. Articles feature new conceptual frameworks for civic learning, curricular…

Camp Marmal Flood Study

DTIC Science & Technology

2012-03-01

was simulated by means of a broad - crested weir built into the topography of the mesh. There is 0.5 m of freeboard and the width of the weir is 30 m...ER D C/ CH L TR -1 2- 5 Camp Marmal Flood Study Co as ta l a nd H yd ra ul ic s La bo ra to ry Jeremy A. Sharp , Steve H. Scott...Camp Marmal Flood Study Jeremy A. Sharp , Steve H. Scott, Mark R. Jourdan, and Gaurav Savant Coastal and Hydraulics Laboratory U.S. Army Engineer

An Examination of "The Martian" Trajectory

NASA Technical Reports Server (NTRS)

Burke, Laura

2015-01-01

This analysis was performed to support a request to examine the trajectory of the Hermes vehicle in the novel "The Martian" by Andy Weir. Weir developed his own tool to perform the analysis necessary to provide proper trajectory information for the novel. The Hermes vehicle is the interplanetary spacecraft that shuttles the crew to and from Mars. It is notionally a Nuclear powered vehicle utilizing VASIMR engines for propulsion. The intent of this analysis was the determine whether the trajectory as it was outlined in the novel is consistent with the rules of orbital mechanics.

Control-structure ratings on the Chicago Sanitary and Ship Canal near Lockport, Illinois

USGS Publications Warehouse

Straub, Timothy D.; Johnson, Kevin K.; Hortness, Jon E.; Duncker, James J.

2012-01-01

The U.S. Army Corps of Engineers and the Metropolitan Water Reclamation District of Greater Chicago regulate flows through control structures along the Lake Michigan lakefront and the Chicago Sanitary and Ship Canal (CSSC) for Lake Michigan diversion accounting, flood control, sanitary, and navigation purposes. This report documents the measurement and computation of flow through the Lockport Controlling Works (LCW) and the Lockport Powerhouse. This analysis aided in evaluation of the ratings at both structures, and the development of new ratings at the controlling works. The LCW structure consists of seven 30-feet (ft) wide sluice gates and is used to divert water from the CSSC and into the Des Plaines River. The flow regimes for the sluice gate included both free and submerged weir. Forty and 491 flow values from U.S. Geological Survey streamflow-gaging stations were used to develop equations describing free- and submerged-weir flow, respectively, through the sluice gates. The equations were developed for canal headwater elevations ranging from -7.0 to -10.5 ft Chicago City Datum (CCD), and tailwater (Des Plaines River at Lockport) to headwater (CSSC-LCW-Base) ratios ranging from 0.31 to 0.66. The Lockport Powerhouse structure consists of nine 9-ft wide by 14-ft high sluice gates and two 10-ft diameter turbines. Both tailwater and no-tailwater effect flow regimes occurred during nine measurements. Also, the canal headwater elevations ranged from -2.74 to -8.45 ft CCD, and the gates were configured six different ways during the measurements.

The effect of thiamine injection on upstream migration, survival, and thiamine status of putative thiamine-deficient coho salmon

USGS Publications Warehouse

Fitzsimons, J.D.; Williston, B.; Amcoff, P.; Balk, L.; Pecor, C.; Ketola, H.G.; Hinterkopf, J.P.; Honeyfield, D.C.

2005-01-01

A diet containing a high proportion of alewives Alosa pseudoharengus results in a thiamine deficiency that has been associated with high larval salmonid mortality, known as early mortality syndrome (EMS), but relatively little is known about the effects of the deficiency on adults. Using thiamine injection (50 mg thiamine/kg body weight) of ascending adult female coho salmon Oncorhynchus kisutch on the Platte River, Michigan, we investigated the effects of thiamine supplementation on migration, adult survival, and thiamine status. The thiamine concentrations of eggs, muscle (red and white), spleen, kidney (head and trunk), and liver and the transketolase activity of the liver, head kidney, and trunk kidney of fish injected with thiamine dissolved in physiological saline (PST) or physiological saline only (PS) were compared with those of uninjected fish. The injection did not affect the number of fish making the 15-km upstream migration to a collection weir but did affect survival once fish reached the upstream weir, where survival of PST-injected fish was almost twice that of controls. The egg and liver thiamine concentrations in PS fish sampled after their upstream migration were significantly lower than those of uninjected fish collected at the downstream weir, but the white muscle thiamine concentration did not differ between the two groups. At the upper weir, thiamine levels in the liver, spleen, head kidney, and trunk kidney of PS fish were indistinguishable from those of uninjected fish (called "wigglers") suffering from a severe deficiency and exhibiting reduced equilibrium, a stage that precedes total loss of equilibrium and death. For PST fish collected at the upstream weir, total thiamine levels in all tissues were significantly elevated over those of PS fish. Based on the limited number of tissues examined, thiamine status was indicated better by tissue thiamine concentration than by transketolase activity. The adult injection method we used appears to be a more effective means of increasing egg thiamine levels than immersion of eggs in a thiamine solution. ?? Copyright by the American Fisheries Society 2005.

Present-day African analogue of a pre-European Amazonian floodplain fishery shows convergence in cultural niche construction.

PubMed

McKey, Doyle B; Durécu, Mélisse; Pouilly, Marc; Béarez, Philippe; Ovando, Alex; Kalebe, Mashuta; Huchzermeyer, Carl F

2016-12-27

Erickson [Erickson CL (2000) Nature 408 (6809):190-193] interpreted features in seasonal floodplains in Bolivia's Beni savannas as vestiges of pre-European earthen fish weirs, postulating that they supported a productive, sustainable fishery that warranted cooperation in the construction and maintenance of perennial structures. His inferences were bold, because no close ethnographic analogues were known. A similar present-day Zambian fishery, documented here, appears strikingly convergent. The Zambian fishery supports Erickson's key inferences about the pre-European fishery: It allows sustained high harvest levels; weir construction and operation require cooperation; and weirs are inherited across generations. However, our comparison suggests that the pre-European system may not have entailed intensive management, as Erickson postulated. The Zambian fishery's sustainability is based on exploiting an assemblage dominated by species with life histories combining high fecundity, multiple reproductive cycles, and seasonal use of floodplains. As water rises, adults migrate from permanent watercourses into floodplains, through gaps in weirs, to feed and spawn. Juveniles grow and then migrate back to dry-season refuges as water falls. At that moment fishermen set traps in the gaps, harvesting large numbers of fish, mostly juveniles. In nature, most juveniles die during the first dry season, so that their harvest just before migration has limited impact on future populations, facilitating sustainability and the adoption of a fishery based on inherited perennial structures. South American floodplain fishes with similar life histories were the likely targets of the pre-European fishery. Convergence in floodplain fish strategies in these two regions in turn drove convergence in cultural niche construction.

National Dam Inspection Program. Johnson’s Pond (NDI-ID Number MD-11), Wicomico River Basin, Wicomico River, Wicomico County, Maryland. Phase I Inspection Report,

DTIC Science & Technology

1980-07-01

a mean high tide of 2.07 feet above m.s.l. and a mean low tide of 0.93 feet below mean sea level. Driven timber sheeting forming a sharp crested weir ...dam for Johnson’s Pond since its crest elevation exceeds mean high tide events. However, during record high tide events, the weir becomes submerged...comprised of a 300 foot long ogee spillway with wingwalls at the left and right abutments. According to the dam crest survey, the lowest point along the

Needleless coaxial electrospinning: A novel approach to mass production of coaxial nanofibers.

PubMed

Vysloužilová, Lucie; Buzgo, Matej; Pokorný, Pavel; Chvojka, Jiří; Míčková, Andrea; Rampichová, Michala; Kula, Jiří; Pejchar, Karel; Bílek, Martin; Lukáš, David; Amler, Evžen

2017-01-10

Herein, we describe a simple spinneret setup for needleless coaxial electrospinning that exceeds the limited production capacity of current approaches. The proposed weir spinneret enables coaxial electrospinning from free liquid surface. This approach leads to the formation of coaxial nanofibers with higher and uniform shell/core ratio, which results in the possibility of better tuning of the degradation rate. The throughput and quality increase favor the broader application of coaxial nanofibers from weir spinnerets as systems for controlled drug delivery in regenerative medicine and tissue engineering. Copyright © 2016 Elsevier B.V. All rights reserved.

National Program for Inspection of Non-Federal Dams. Old Quincy Reservoir Dam (MA 00827), Massachusetts-Rhode Island Coastal Basin, Braintree, Massachusetts. Phase I Inspection Report.

DTIC Science & Technology

1979-11-01

flood protection to the urban - ized area located downstream along Town Brook. The pond has a water surface area of approximately 36 acres and a storage...in a 1970 paper entitled "Effect of Urban Expansion on Hydrologic Investigations". A peak inflow rate of 1760 csm was adopted for the 1.44 sq. mi...etc. C. None. 2. Weir 2. a. Flashboards a. None. b. Weir Elev. Control (Gate) b. None. c. Vegetation c. Light brush and weeds - two trees d. Seepage or

Is diversity good? Six possible conceptions of diversity and six possible answers.

PubMed

Bouville, Mathieu

2008-03-01

Prominent ethical and policy issues such as affirmative action and female enrollment in science and engineering revolve around the idea that diversity is good. However, a precise definition is seldom provided. I show that diversity may be construed as a factual description, a craving for symmetry, an intrinsic good, an instrumental good, a symptom, or a side effect. These acceptions differ vastly in their nature and properties. Some are deeply mistaken and some others cannot lead to concrete policies. It is thus necessary to clarify what one means by 'diversity.' It may be a neutral description of a given state; but this is insufficient to act. The idea that there should be the same representation in a specific context as in the overall population is both puzzling and arbitrary. Diversity as intrinsic good is a mere opinion, which cannot be concretely applied; moreover, the most commonly invoked forms of diversity (sexual and racial) are not intrinsically good. On the other hand, diversity as instrumental good can be evaluated empirically and can give rise to policies, but these may be very weak. Finally, symptoms and side effects are not actually about diversity. I consider the example of female enrollment in science and engineering, interpreting the various arguments found in the literature in light of this polysemy.

Steelhead Supplementation Studies; Steelhead Supplementation in Idaho Rivers, Annual Report 2002.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Byrne, Alan

The Steelhead Supplementation Study (SSS) has two broad objectives: (1) investigate the feasibility of supplementing depressed wild and natural steelhead populations using hatchery populations, and (2) describe the basic life history and genetic characteristics of wild and natural steelhead populations in the Salmon and Clearwater Basins. Idaho Department of Fish and Game (IDFG) personnel stocked adult steelhead from Sawtooth Fish Hatchery into Frenchman and Beaver creeks and estimated the number of age-1 parr produced from the outplants since 1993. On May 2, 2002, both Beaver and Frenchman creeks were stocked with hatchery adult steelhead. A SSS crew snorkeled the creeksmore » in August 2002 to estimate the abundance of age-1 parr from brood year (BY) 2001. I estimated that the yield of age-1 parr per female stocked in 2001 was 7.3 and 6.7 in Beaver and Frenchman creeks, respectively. SSS crews stocked Dworshak hatchery stock fingerlings and smolts from 1993 to 1999 in the Red River drainage to assess which life stage produces more progeny when the adults return to spawn. In 2002, Clearwater Fish Hatchery personnel operated the Red River weir to trap adults that returned from these stockings. Twelve PIT-tagged adults from the smolt releases and one PIT-tagged adult from fingerling releases were detected during their migration up the mainstem Columbia and Snake rivers, but none from either group were caught at the weir. The primary focus of the study has been monitoring and collecting life history information from wild steelhead populations. An adult weir has been operated annually since 1992 in Fish Creek, a tributary of the Lochsa River. The weir was damaged by a rain-on-snow event in April 2002 and although the weir remained intact, some adults were able to swim undetected through the weir. Despite damage to the weir, trap tenders captured 167 adult steelhead, the most fish since 1993. The maximum likelihood estimate of adult steelhead escapement was 242. A screw trap has been operated annually in Fish Creek since 1994 to estimate the number of emigrating parr and smolts. I estimated that 18,687 juvenile steelhead emigrated from Fish Creek in 2002, the lowest number of migrants since 1998. SSS crews snorkeled three streams in the Selway River drainage and 10 streams in the Lochsa River drainage to estimate juvenile steelhead densities. The densities of age-1 steelhead parr declined in all streams compared to the densities observed in 2001. The age-1 densities in Fish Creek and Gedney Creek were the lowest observed since this project began monitoring those populations in 1994. The SSS crews and other cooperators tagged more than 12,000 juvenile steelhead with passive integrated transponder (PIT) tags in 2002. In 2002, technicians mounted and aged steelhead scales that were collected from 1998 to 2001. A consensus was reached among technicians for age of steelhead juveniles from Fish Creek. Scales that were collected in other streams were aged by at least one reader; however, before a final age is assigned to these fish, the age needs to be verified by another reader and any age differences among readers resolved. Dr. Jennifer Nielsen, at the U.S. Geological Survey Alaska Biological Science Center, Anchorage continued the microsatellite analysis of the steelhead tissue samples that were collected from Idaho streams in 2000. Two thousand eighteen samples from 40 populations were analyzed. The analysis of the remaining 39 populations is continuing.« less

54. Downstream face of Agua Fria project's diversion dam showing ...

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

54. Downstream face of Agua Fria project's diversion dam showing initial masonry construction and poured concrete capping. Photographer Mark Durben, 1986. Source: Salt River Project. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

Present-day African analogue of a pre-European Amazonian floodplain fishery shows convergence in cultural niche construction

PubMed Central

McKey, Doyle B.; Durécu, Mélisse; Pouilly, Marc; Béarez, Philippe; Ovando, Alex; Kalebe, Mashuta; Huchzermeyer, Carl F.

2016-01-01

Erickson [Erickson CL (2000) Nature 408 (6809):190–193] interpreted features in seasonal floodplains in Bolivia’s Beni savannas as vestiges of pre-European earthen fish weirs, postulating that they supported a productive, sustainable fishery that warranted cooperation in the construction and maintenance of perennial structures. His inferences were bold, because no close ethnographic analogues were known. A similar present-day Zambian fishery, documented here, appears strikingly convergent. The Zambian fishery supports Erickson’s key inferences about the pre-European fishery: It allows sustained high harvest levels; weir construction and operation require cooperation; and weirs are inherited across generations. However, our comparison suggests that the pre-European system may not have entailed intensive management, as Erickson postulated. The Zambian fishery’s sustainability is based on exploiting an assemblage dominated by species with life histories combining high fecundity, multiple reproductive cycles, and seasonal use of floodplains. As water rises, adults migrate from permanent watercourses into floodplains, through gaps in weirs, to feed and spawn. Juveniles grow and then migrate back to dry-season refuges as water falls. At that moment fishermen set traps in the gaps, harvesting large numbers of fish, mostly juveniles. In nature, most juveniles die during the first dry season, so that their harvest just before migration has limited impact on future populations, facilitating sustainability and the adoption of a fishery based on inherited perennial structures. South American floodplain fishes with similar life histories were the likely targets of the pre-European fishery. Convergence in floodplain fish strategies in these two regions in turn drove convergence in cultural niche construction. PMID:27980030

Effectiveness of Devices to Monitor Biofouling and Metals Deposition on Plumbing Materials Exposed to a Full-Scale Drinking Water Distribution System

PubMed Central

Garbin, Scott; Wylie, Jason; Krishna, K. C. Bal

2017-01-01

A Modified Robbins Device (MRD) was installed in a full-scale water distribution system to investigate biofouling and metal depositions on concrete, high-density polyethylene (HDPE) and stainless steel surfaces. Bulk water monitoring and a KIWA monitor (with glass media) were used to offline monitor biofilm development on pipe wall surfaces. Results indicated that adenosine triphosphate (ATP) and metal concentrations on coupons increased with time. However, bacterial diversities decreased. There was a positive correlation between increase of ATP and metal deposition on pipe surfaces of stainless steel and HDPE and no correlation was observed on concrete and glass surfaces. The shared bacterial diversity between bulk water and MRD was less than 20% and the diversity shared between the MRD and KIWA monitor was only 10%. The bacterial diversity on biofilm of plumbing material of MRD however, did not show a significant difference suggesting a lack of influence from plumbing material during early stage of biofilm development. PMID:28060947

15. VIEW SHOWING WATER FLOWING THROUGH THE ORIGINAL DIVERSION GATE ...

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

15. VIEW SHOWING WATER FLOWING THROUGH THE ORIGINAL DIVERSION GATE FROM THE OUTLET CHANNEL INTO THE BY-PASS CHANNEL LEADING TO THE ORIGINAL SOURIS RIVER CHANNEL (Note: this gate has since been replaced with concrete diversion gates, see HAER Photograph No ND-3-A-7) - Upper Souris National Wildlife Refuge, Dam 83, Souris River Basin, Foxholm, Surrey (England), ND

Fish passage and abundance around grade control structures on incised streams

USGS Publications Warehouse

Thomas, J.T.; Papanicolaou, A.N.; Pierce, C.L.; Dermisis, D.C.; Litvan, M.E.; Larson, C.J.

2009-01-01

This paper summarizes research from separate studies of fish passage over weirs (Larson et al., 2004; Litvan, 2006; Litvan, et al., 2008a-c) and weir hydraulics (Papanicolaou and Dermisis, 2006; Papanicolaou and Dermisis, in press). Channel incision in the deep loess region of western Iowa has caused decreased biodiversity because streams have high sediment loads, altered flow regimes, lost habitat, and lost lateral connectivity with their former floodplains. In-stream grade control structures (GCS) are built to prevent further erosion, protect infrastructure, and reduce sediment loads. However, GCS can have a detrimental impact on fisheries abundance and migration, biodiversity, and longitudinal connectivity. Fish mark-recapture studies were performed on stretches of streams with and without GCS. GCS with vertical or 1:4 (rise/run) downstream slopes did not allow fish migration, but GCS with slopes ??? 1:15 did. GCS sites were characterized by greater proportions of pool habitat, maximum depths, fish biomass, slightly higher index of biotic integrity (IBI) scores, and greater macroinvertebrate abundance and diversity than non-GCS sites. After modification of three GCS, IBI scores increased and fish species exhibiting truncated distributions before were found throughout the study area. Another study examined the hydraulic performance of GCS to facilitate unimpeded fish passage by determining the mean and turbulent flow characteristics in the vicinity of the GCS via detailed, non-intrusive field tests. Mean flow depth (Y) and velocity (V) atop the GCS were critical for evaluating GCS performance. Turbulent flow measurements illustrated that certain GCS designs cause sudden constrictions which form eddies large enough to disorient fish. GCS with slopes ??? 1:15 best met the minimum requirements to allow catfish passage of a flow depth of ??? 0.31 m and a mean flow velocity of ??? 1.22 m/s. ?? 2009 ASCE.

Long term numerical investigations of measures to increase the structural variability and the fish passability of the river Iller

NASA Astrophysics Data System (ADS)

Seitz, Lydia; Haun, Stefan; Wieprecht, Silke

2017-04-01

The river Iller origins at Oberstdorf in the Allgäu Alps and drains after 147 km into the river Danube. During the past decades the river Iller was considerable modified due to hydropower development and due to the construction of weirs and ramps to avoid ongoing river bed deepening. As consequence between km 52.9 - 39.3 almost equilibrium conditions of the river bed were reached. The aim of this study is to investigate with a 1D - 2D coupled numerical sediment transport model the long term effects (50 years) of different measures, which will be implemented to improve structural variability of the river Iller and to improve the passability for fishes. In a first step long term morphological trends will be investigated for replacing weirs by ramps. This will enable and improve the passability for fishes and sediments. In a second step the remobilization of already deposited sediments is investigated. Therefore the weir downstream of a gravel bar will be lowered stepwise (between 1.0 and 2.5 m) to see under which conditions the sediments can be remobilized. In a third step artificial sediment feeding will be simulated to find adequate spots for the sediment supply and to investigate the amount of sediments which have to be added to the river to improve structural variability of the river Iller. The numerical model framework BASEMENT, developed at the ETH Zürich, is used for the investigations. In the model fractional sediment transport is implemented with 9 grain sizes between 0.5 mm and 128 mm. Two layers are implemented to simulate the armouring of the river bed. Due to absence of very fine sediments and the fact that bed load transport is the governing sediment transport mode the Meyer-Peter and Müller bed load transport formula, with an extension by Hunziker for multiple grain classes, is used for the simulations. The critical Shields parameter, used to obtain the critical shear stress in BASEMENT, is evaluated as a function of the dimensionless grain diameter accordingly to van Rijn. The results show that the passability can be increased by replacing weirs by ramps (three in total) without negative morphological effects on this section. Furthermore, the simulated results show that the deposited sediments can be remobilized by lowering the weir, resulting in ongoing dynamic morphological bed changes and so a structural variability of the river. However, it can be seen that this dynamic processes fade away over time due to the large number of hydraulic structures along the river. The results of the artificial sediment supply (one time supply with an amount between 5,000 to 12,500 m3) shows a similar trend as the lowering of the weir over time, where right at the beginning morphological bed changes can be seen, these processes decrease and even stop within a couple of years.

Forensic collection of trace chemicals from diverse surfaces with strippable coatings.

PubMed

Jakubowski, Michael J; Beltis, Kevin J; Drennan, Paul M; Pindzola, Bradford A

2013-11-07

Surface sampling for chemical analysis plays a vital role in environmental monitoring, industrial hygiene, homeland security and forensics. The standard surface sampling tool, a simple cotton gauze pad, is failing to meet the needs of the community as analytical techniques become more sensitive and the variety of analytes increases. In previous work, we demonstrated the efficacy of non-destructive, conformal, spray-on strippable coatings for chemical collection from simple glass surfaces. Here we expand that work by presenting chemical collection at a low spiking level (0.1 g m(-2)) from a diverse array of common surfaces - painted metal, engineering plastics, painted wallboard and concrete - using strippable coatings. The collection efficiency of the strippable coatings is compared to and far exceeds gauze pads. Collection from concrete, a particular challenge for wipes like gauze, averaged 73% over eight chemically diverse compounds for the strippable coatings whereas gauze averaged 10%.

Operations Plans for Anadromous Fish Production Facilities in the Columbia River Basin, Volume II of V; 1992 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hutchison, Bill

1993-05-01

Clearwater Hatchery is located on the north bank of the North Fork of the Clearwater River, downstream from Dworshak Dam. It is approximately 72 miles from Lower Granite Dam, and 504 miles from the mouth of the Columbia River. Site elevation is approximately 994 feet above sea level. The hatchery is staffed with 7 FTE's. Clearwater Hatchery has two pipelines from Dworshak Reservoir. One is attached to a floating platform and is capable of providing various temperatures at varying depths. The other is a stationary intake about 245 feet below the top of the dam. All water is gravity fedmore » to the hatchery. An l8 inch intake pipe provides an estimated 10 cfs with temperature remaining constant at approximately 40 F. The primary 42-inch intake pipe can draw water from 5 to 45 feet in depth with temperatures ranging from 55 to 60 F and 70 cfs of flow. The hatchery facility consists of 11 chinook raceways, 24 steelhead raceways, 2 adult holding ponds, a covered spawning area with 2 live wells and 60 concrete rearing vats. There are 40 double stacks of Heath-type incubators and each vat also has an incubation jar. All facility units are in excellent condition. Clearwater Hatchery also supports satellite facilities at Red River, Crooked River and Powell. The Red River satellite facility is located approximately 15 miles east of Elk City, Idaho. It is approximately 186 miles upstream from Lower Granite Dam and 618 miles from the mouth of the Columbia River. It was first built in 1974 by the Columbia River Project and then remodeled by the U.S. Army Corps of Engineers in 1986. Red River is supplied by gravity flow from an intake located at the bottom of the South Fork of Red River, 225 yards upstream from the facility. Water rights allow for 10 cfs and during low flows in the summer about 5 cfs is available. Temperatures range from 40 F in the spring to 71 F in early August. The facility consists of two adult holding ponds, a removable tripod and panel weir, and a rearing pond. All units are in good condition due to the recent remodeling. The Crooked River satellite facility is located 20 miles downstream of Red River. The trap is located 0.5 miles upstream of the mouth of Crooked River, a tributary of the South Fork of the Clearwater River. The rearing ponds are 10 miles upstream from the Crooked River adult trap. Crooked River water is supplied by gravity flow by an intake 200 yards upstream of the facility raceways. Water rights allow for 10 cfs at the rearing facility and 10 cfs at the trapping facility. Water temperatures range from 42 to 70 F. The trap and weir are located at the mouth of Crooked River. Ten miles upstream from the mouth are two raceways, a cleaning waste pond and final settling pond. All facility units are in good condition. The Powell satellite facility is located 122 miles east of the Clear-water Hatchery at the headwaters of the Lochsa River, the confluence of the Crooked Fork Creek and White Sands Creek. Powell is 192.5 miles from Lower Granite Dam and 624 miles from the mouth of the Columbia River. The Powell Facility receives gravity flow water from Walton Creek at a rate of 7 cfs with the intake being located 100 yards upstream from the facility. Powell also has a pumped supply from White Sands Creek at 3 cfs. Water temperature ranges from 45.8 to 50.2 F from the Walton Creek intake and 41 to 65 F from the White Sands pump station. The facility consists of one rearing pond, a diversion and intake screen, two adult holding ponds, a floating weir, and an open bay spawning shelter. All facility units are in good condition.« less

Improving flow distribution in influent channels using computational fluid dynamics.

PubMed

Park, No-Suk; Yoon, Sukmin; Jeong, Woochang; Lee, Seungjae

2016-10-01

Although the flow distribution in an influent channel where the inflow is split into each treatment process in a wastewater treatment plant greatly affects the efficiency of the process, and a weir is the typical structure for the flow distribution, to the authors' knowledge, there is a paucity of research on the flow distribution in an open channel with a weir. In this study, the influent channel of a real-scale wastewater treatment plant was used, installing a suppressed rectangular weir that has a horizontal crest to cross the full channel width. The flow distribution in the influent channel was analyzed using a validated computational fluid dynamics model to investigate (1) the comparison of single-phase and two-phase simulation, (2) the improved procedure of the prototype channel, and (3) the effect of the inflow rate on flow distribution. The results show that two-phase simulation is more reliable due to the description of the free-surface fluctuations. It should first be considered for improving flow distribution to prevent a short-circuit flow, and the difference in the kinetic energy with the inflow rate makes flow distribution trends different. The authors believe that this case study is helpful for improving flow distribution in an influent channel.

Utilization of fly ash and ultrafine GGBS for higher strength foam concrete

NASA Astrophysics Data System (ADS)

Gowri, R.; Anand, K. B.

2018-02-01

Foam concrete is a widely accepted construction material, which is popular for diverse construction applications such as, thermal insulation in buildings, lightweight concrete blocks, ground stabilization, void filling etc. Currently, foam concrete is being used for structural applications with a density above 1800kg/m3. This study focuses on evolving mix proportions for foam concrete with a material density in the range of 1200 kg/m3 to 1600 kg/m3, so as to obtain strength ranges that will be sufficient to adopt it as a structural material. Foam concrete is made lighter by adding pre-formed foam of a particular density to the mortar mix. The foaming agent used in this study is Sodium Lauryl Sulphate and in order to densify the foam generated, Sodium hydroxide solution at a normality of one is also added. In this study efforts are made to make it a sustainable construction material by incorporating industrial waste products such as ultrafine GGBS as partial replacement of cement and fly ash for replacement of fine aggregate. The fresh state and hardened state properties of foam concrete at varying proportions of cement, sand, water and additives are evaluated. The proportion of ultrafine GGBS and fly ash in the foam concrete mix are varied aiming at higher compressive strength. Studies on air void-strength relationship of foam concrete are also included in this paper.

Potential linkage between sediment oxygen demand and pore water chemistry in weir-impounded rivers.

PubMed

Lee, Mi-Hee; Jung, Heon-Jae; Kim, Sung-Han; An, Sung-Uk; Choi, Jung Hyun; Lee, Hyo-Jin; Huh, In-Ae; Hur, Jin

2018-04-01

Due to recent weir construction on four major rivers in South Korea, sediment has accumulated in the river bottom near the weirs, which has in turn raised concerns over the quality of overlying water. In this study, the seasonal and spatial variations of sediment oxygen demand (SOD) and the influencing factors were explored using pore water chemistry for the weir-impounded rivers. Muddy and sandy sediment samples were taken from 24 different sites along the four major rivers in summer and autumn, 2016. The SOD was measured in a laboratory based on 10-hour incubation at in situ temperature. The measured pore water chemistry included the concentrations of dissolved organic carbon (DOC), total dissolved nitrogen (TDN), inorganic nitrogen (NH 3 -N, NO 3 -N, NO 2 -N), and phosphate phosphorous (PO 4 -P), and the optical properties from UV absorption spectra and fluorescence excitation-emission matrixes coupled with parallel factor analysis (EEM-PARAFAC). Significant differences in SOD values between muddy and sandy sediments were found only in summer (p=0.047). The higher SOD in summer versus autumn (p=0.015) was attributed to seasonal temperature differences. The higher NH 3 -N and the lower NO 3 -N of the pore water samples in summer versus autumn suggested that organic nitrogen decomposition via an ammonification and nitrification process could operate as an important factor for the SOD variations in summer and autumn, respectively. Principal component analysis revealed the mutual contributions of nitrogen-associated processes and the organic composition in pore water to increasing SOD levels. NH 3 -N in sediment pore water alone could be a good predictor for SOD. However, multiple regression analysis using NH 3 -N, fluorescence index and terrestrial humic-like components improved the estimation capability for SOD variations. Copyright © 2017 Elsevier B.V. All rights reserved.

Hydrologic assessment of the Upper Dorr Run Watershed, Hocking County, Ohio, 1998

USGS Publications Warehouse

Haefner, R.J.

1999-01-01

The Upper Dorr Run Watershed in Hocking County, Ohio, has been mined several times for coal and clay since 1913 and is a significant source of acid mine drainage to the Hocking River. To assess the surface-water hydrology of the site, a topographic map showing the location of springs and other hydrologic features of interest was prepared using aerial photography and field surveying and mapping techniques. Discharge and water-quality measurements at six springs and one stream site were made during field investigations in June 1998. Discharge and water quality observed at a downstream weir on Upper Dorr Run represents the combined discharge from springs plus ground-water inflow. Discharges from springs to surface water were generally small (less than 0.3 cubic foot per second), but one spring constituted 56 percent of the total discharge measured at the downstream weir. The total flow at an intermediate measurement site was less than the combined discharge of the upgradient springs because of evaporation, transpiration, and ground-water flow beneath the stream channel. The total flow at the weir was greater than the combined discharge of all springs, primarily because two potential sources of water were not included in field measurements. The water quality in Upper Dorr Run is strongly affected by acid mine drainage as indicated by pH less than 4, elevated acidity, and elevated concentrations of dissolved sulfate and dissolved iron. Concentrations of chemical constituents in the water were lower at the downstream weir than at the source springs because of residence times in ponds and chemical interactions between the water and the atmosphere. Acidity loads during the sampling period were significantly higher from the Lower Kittanning (No. 5) coal (272 kilograms per day) than from the Upper Kittanning (No. 6) coal (17.7 kilograms per day). Comparison of data obtained in 1998 to data obtained in 1982 showed that quality of water of selected sampling sites had not changed appreciably in 16 years.

Nonlinear pressure-flow relationships for passive microfluidic valves.

PubMed

Seker, Erkin; Leslie, Daniel C; Haj-Hariri, Hossein; Landers, James P; Utz, Marcel; Begley, Matthew R

2009-09-21

An analytical solution is presented for the nonlinear pressure-flow relationship of deformable passive valves, which are formed by bonding a deformable film over etched channels separated by a weir. A fluidic pathway connecting the channels is opened when the upstream pressure creates a tunnel along a predefined narrow strip where the film is not bonded to the weir. When the width of the strip is comparable to the inlet channel width, the predicted closed-form pressure-flow rate relationship is in excellent agreement with experiments, which determine pressures by measuring film deflections for prescribed flow rates. The validated closed-form models involve no fitting parameters, and provide the foundation to design passive diodes with specific nonlinear pressure-flow characteristics.

Special Issue: Bridging the Diversity Divide--Globalization and Reciprocal Empowerment in Higher Education

ERIC Educational Resources Information Center

Chun, Edna; Evans, Alvin

2009-01-01

In this monograph, the authors focus on concrete approaches and tools that will assist educational leaders and educators in the creation of a genuinely inclusive campus culture. The first chapter, "The Changing Landscape and the Compelling Need for Diversity," provides an overview of forces that have historically inhibited the inclusion of women…

Two Steps Forward, One Step Backward: Must This Be the Future of Diversity?

ERIC Educational Resources Information Center

Butler, Johnnella E.

2013-01-01

Johnnella Butler writes here that the title of this article "Two Steps Forward, One Step Backward," expresses the "wicked problem" of diversity as a concrete goal in higher education. The concept of the "wicked problem," is a term coined in the late 1960s by social planners. Consulting Wikipedia, as so many of our…

Targeting Academic Programs to Student Diversity Utilizing Learning Styles and Learning-Study Strategies.

ERIC Educational Resources Information Center

Grimes, Sue K.

1995-01-01

A diagnostic, prescriptive model was utilized (n=394) in identification of learning styles and learning-study strategies of diverse student groups and in the analysis of prescriptive methods to address their specific needs. High-risk groups demonstrated auditory, tactile concrete, and group learning style preferences and were weaker on cognitive,…

Changes in fish communities following concrete lining of the Coachella Canal, southeastern California

USGS Publications Warehouse

Mueller, Gordon; Bryant, Gary; Burke, Tom

1989-01-01

The fish community of a 3.4-km section of the concrete-lined Coachella Canal, Imperial County, California, was comprised of six species, with an absolute density of 0.039 fish/m2 and estimated biomass of 4.367 g/m2. When compared to studies conducted in the canal prior to lining, or in other unlined areas, these data suggest reductions in species diversity (-14.3 to -62.5%), density (+8.9 to =83.8%), and biomass (-30.1 to -91.2%). These data support speculations that numbers of river-adapted fish would remain relatively high in a concrete-lined canal, but lentic and cover-oriented fishes such as centrarchis would decline.

Get Cracking.

ERIC Educational Resources Information Center

Croll, Doreen A.

1986-01-01

Presents a diversity of concrete experiences that can be used with eggs for young elementary age students. Includes procedures and material list for several activities that are hands-on and interdisciplinary in nature. (ML)

Wastewater-Enhanced Microbial Corrosion of Concrete Sewers.

PubMed

Jiang, Guangming; Zhou, Mi; Chiu, Tsz Ho; Sun, Xiaoyan; Keller, Jurg; Bond, Philip L

2016-08-02

Microbial corrosion of concrete in sewers is known to be caused by hydrogen sulfide, although the role of wastewater in regulating the corrosion processes is poorly understood. Flooding and splashing of wastewater in sewers periodically inoculates the concrete surface in sewer pipes. No study has systematically investigated the impacts of wastewater inoculation on the corrosion of concrete in sewers. This study investigated the development of the microbial community, sulfide uptake activity, and the change of the concrete properties for coupons subjected to periodic wastewater inoculation. The concrete coupons were exposed to different levels of hydrogen sulfide under well-controlled conditions in laboratory-scale corrosion chambers simulating real sewers. It was evident that the periodic inoculation induced higher corrosion losses of the concrete in comparison to noninoculated coupons. Instantaneous measurements such as surface pH did not reflect the cumulative corrosion losses caused by long-term microbial activity. Analysis of the long-term profiles of the sulfide uptake rate using a Gompertz model supported the enhanced corrosion activity and greater corrosion loss. The enhanced corrosion rate was due to the higher sulfide uptake rates induced by wastewater inoculation, although the increasing trend of sulfide uptake rates was slower with wastewater. Increased diversity in the corrosion-layer microbial communities was detected when the corrosion rates were higher. This coincided with the environmental conditions of increased levels of gaseous H2S and the concrete type.

Language used in interaction during developmental science instruction

NASA Astrophysics Data System (ADS)

Avenia-Tapper, Brianna

The coordination of theory and evidence is an important part of scientific practice. Developmental approaches to instruction, which make the relationship between the abstract and the concrete a central focus of students' learning activity, provide educators with a unique opportunity to strengthen students' coordination of theory and evidence. Therefore, developmental approaches may be a useful instructional response to documented science achievement gaps for linguistically diverse students. However, if we are to leverage the potential of developmental instruction to improve the science achievement of linguistically diverse students, we need more information on the intersection of developmental science instruction and linguistically diverse learning contexts. This manuscript style dissertation uses discourse analysis to investigate the language used in interaction during developmental teaching-learning in three linguistically diverse third grade classrooms. The first manuscript asks how language was used to construct ascension from the abstract to the concrete. The second manuscript asks how students' non-English home languages were useful (or not) for meeting the learning goals of the developmental instructional program. The third manuscript asks how students' interlocutors may influence student choice to use an important discourse practice--justification--during the developmental teaching-learning activity. All three manuscripts report findings relevant to the instructional decisions that teachers need to make when implementing developmental instruction in linguistically diverse contexts.

Artificial barriers prevent genetic recovery of small isolated populations of a low-mobility freshwater fish.

PubMed

Coleman, R A; Gauffre, B; Pavlova, A; Beheregaray, L B; Kearns, J; Lyon, J; Sasaki, M; Leblois, R; Sgro, C; Sunnucks, P

2018-06-01

Habitat loss and fragmentation often result in small, isolated populations vulnerable to environmental disturbance and loss of genetic diversity. Low genetic diversity can increase extinction risk of small populations by elevating inbreeding and inbreeding depression, and reducing adaptive potential. Due to their linear nature and extensive use by humans, freshwater ecosystems are especially vulnerable to habitat loss and fragmentation. Although the effects of fragmentation on genetic structure have been extensively studied in migratory fishes, they are less understood in low-mobility species. We estimated impacts of instream barriers on genetic structure and diversity of the low-mobility river blackfish (Gadopsis marmoratus) within five streams separated by weirs or dams constructed 45-120 years ago. We found evidence of small-scale (<13 km) genetic structure within reaches unimpeded by barriers, as expected for a fish with low mobility. Genetic diversity was lower above barriers in small streams only, regardless of barrier age. In particular, one isolated population showed evidence of a recent bottleneck and inbreeding. Differentiation above and below the barrier (F ST  = 0.13) was greatest in this stream, but in other streams did not differ from background levels. Spatially explicit simulations suggest that short-term barrier effects would not be detected with our data set unless effective population sizes were very small (<100). Our study highlights that, in structured populations, the ability to detect short-term genetic effects from barriers is reduced and requires more genetic markers compared to panmictic populations. We also demonstrate the importance of accounting for natural population genetic structure in fragmentation studies.

78 FR 20911 - Archon Energy 1, Inc.; Notice of Preliminary Permit Application Accepted for Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-08

... a short diversion method. The in-stream option would consist of the following: (1) A gated water intake canal; (2) a 70-foot by 55-foot by 35-foot turbine structure enclosing two in-stream VLH turbine... consist of the following: (1) a gated water intake canal; (2) a concrete trough diversion channel...

78 FR 20911 - Archon Energy 1, Inc.; Notice of Preliminary Permit Application Accepted for Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-08

... following: (1) A gated water intake canal; (2) a 330-foot-long diversion canal; (3) a 30-foot-wide concrete diversion approximately 1,300 feet in length; (4) a 50-by-40-foot powerhouse and turbine structure enclosing one Kaplan turbine and generator; and (5) appurtenant facilities. The proposed project would have a...

Adult chinook salmon passage at Little Goose Dam in relation to spill operations

USGS Publications Warehouse

Jepson, M.A.; Caudill , C.C.; Clabough, T.S.; Peery, C.A.; Beeman, J.W.; Fielding, S.

2009-01-01

Spill patterns at Little Goose Dam in 2007 were modified in anticipation of a spillway weir installation intended to improve downstream passage of juvenile salmonids. However, in spill pattern was associated with reduced daily counts of adult salmon passing the dam. Consequently, the behaviors and upstream passage times of radio-tagged adult spring–summer Chinook salmon were evaluated in response to three spillway discharge patterns at Little Goose Dam during 2008. Simultaneously, tailrace conditions were characterized by monitoring the downstream paths of GPS-equipped drogues. Two of the spill treatments (i.e., Bulk and Alternate) were variations of patterns thought to mimic those produced if a spillway weir was installed. The third treatment (Uniform) was characterized by spilling similar volumes of water through most spillbays.

Simulations of a hypothetical temperature control structure at Detroit Dam on the North Santiam River, northwestern Oregon

USGS Publications Warehouse

Buccola, Norman L.; Stonewall, Adam J.; Rounds, Stewart A.

2015-01-01

Estimated egg-emergence days for endangered Upper Willamette River Chinook salmon (Oncorhynchus tshawytscha) and Upper Willamette River winter steelhead (Oncorhynchus mykiss) were assessed for all scenarios. Estimated spring Chinook fry emergence under SlidingWeir scenarios was 9 days later immediately downstream of Big Cliff Dam, and 4 days later at Greens Bridge compared with existing structural scenarios at Detroit Dam. Despite the inclusion of a hypothetical sliding weir at Detroit Dam, temperatures exceeded without-dams temperatures during November and December. These late-autumn exceedances likely represent the residual thermal effect of Detroit Lake operated to meet minimum dry-season release rates (supporting instream habitat and irrigation requirements) and lake levels specified by the current (2014) operating rules (supporting recreation and flood mitigation).

Evaluation of tire reefs for enhancing aquatic communities in concrete-lined canals

USGS Publications Warehouse

Mueller, Gordon; Liston, Charles R.

1994-01-01

Large earthen canals in the arid southwest are being lined with concrete to reduce seepage and conserve limited water supplies. Lining reduces habitat and increases operational velocities (relative to unaltered streams), which are detrimental to aquatic communities. Fish communities that become reestablished in these waterways exhibit lower species diversity, densities, and biomass than they did in the former earthen canals. Placement of low-profile tire reefs in the Coachella Canal, California, and the Hayden-Rhodes Aqueduct, Arizona, reversed these trends. Comparative sampling revealed that invertebrate and fish densities were 3 and 20 times higher, respectively, in reef areas than in typical canal sections without reefs. Tire reefs are recommended as an effective means of enhancing aquatic communities in concrete canals.

Lining seam elimination algorithm and surface crack detection in concrete tunnel lining

NASA Astrophysics Data System (ADS)

Qu, Zhong; Bai, Ling; An, Shi-Quan; Ju, Fang-Rong; Liu, Ling

2016-11-01

Due to the particularity of the surface of concrete tunnel lining and the diversity of detection environments such as uneven illumination, smudges, localized rock falls, water leakage, and the inherent seams of the lining structure, existing crack detection algorithms cannot detect real cracks accurately. This paper proposed an algorithm that combines lining seam elimination with the improved percolation detection algorithm based on grid cell analysis for surface crack detection in concrete tunnel lining. First, check the characteristics of pixels within the overlapping grid to remove the background noise and generate the percolation seed map (PSM). Second, cracks are detected based on the PSM by the accelerated percolation algorithm so that the fracture unit areas can be scanned and connected. Finally, the real surface cracks in concrete tunnel lining can be obtained by removing the lining seam and performing percolation denoising. Experimental results show that the proposed algorithm can accurately, quickly, and effectively detect the real surface cracks. Furthermore, it can fill the gap in the existing concrete tunnel lining surface crack detection by removing the lining seam.

UV water disinfector

DOEpatents

Gadgil, Ashok; Garud, Vikas

1998-07-14

A UV disinfector with a gravity driven feed water delivery system, and an air-suspended bare UV lamp. The disinfector is hydrodynamically optimized with a laminerizing, perforated baffle wall, beveled treatment chamber, and outlet weir.

First record of epizootic ulcerative syndrome from the Upper Congo catchment: An outbreak in the Bangweulu swamps, Zambia.

PubMed

Huchzermeyer, C F; Huchzermeyer, K D A; Christison, K W; Macey, B M; Colly, P A; Hang'ombe, B M; Songe, M M

2018-01-01

We report on the first outbreak of epizootic ulcerative syndrome (EUS) amongst wild fish populations in the Bangweulu swamps, an inland delta, in the north of Zambia during 2014. The area supports a large and diverse fish fauna related to, but distinct from, that of the Zambezi River system where EUS outbreaks have occurred since 2006. A sizeable artisanal fishery, based on extensive fish weirs, is sustained by the annual flooding of the swamps, and observations of the disease outbreak by fishermen were recorded. Signs typical of infection with Aphanomyces invadans were observed in a number of species. Clinical observations, histology and molecular diagnostic methods were used to confirm infection with A. invadans in two of the most commonly and severely affected species. Several features of the wetland may have contributed to the outbreak and the annual recurrence of the disease. Modes by which the disease may have been introduced into the swamps are discussed. The outbreak is of great significance as the Bangweulu swamps drain into the Congo River in neighbouring Democratic Republic of Congo, Africa's largest drainage system with an extensive and diverse fish fauna previously unaffected by EUS. © 2017 John Wiley & Sons Ltd.

Turbulence study in the vicinity of piano key weir: relevance, instrumentation, parameters and methods

NASA Astrophysics Data System (ADS)

Tiwari, Harinarayan; Sharma, Nayan

2017-05-01

This research paper focuses on the need of turbulence, instruments reliable to capture turbulence, different turbulence parameters and some advance methodology which can decompose various turbulence structures at different levels near hydraulic structures. Small-scale turbulence research has valid prospects in open channel flow. The relevance of the study is amplified as we introduce any hydraulic structure in the channel which disturbs the natural flow and creates discontinuity. To recover this discontinuity, the piano key weir (PKW) might be used with sloped keys. Constraints of empirical results in the vicinity of PKW necessitate extensive laboratory experiments with fair and reliable instrumentation techniques. Acoustic Doppler velocimeter was established to be best suited within range of some limitations using principal component analysis. Wavelet analysis is proposed to decompose the underlying turbulence structure in a better way.

Thin layer drying of cassava starch using continuous vibrated fluidized bed dryer

NASA Astrophysics Data System (ADS)

Suherman, Trisnaningtyas, Rona

2015-12-01

This paper present the experimental work and thin layer modelling of cassava starch drying in continuous vibrated fluidized bed dryer. The experimental data was used to validate nine thin layer models of drying curve. Cassava starch with 0.21 initial moisture content was dried in different air drying temperature (50°C, 55°C, 60°C, 65°C, 70°C), different weir height in bed (0 and 1 cm), and different solid feed flow (10 and 30 gr.minute-1). The result showed air dryer temperature has a significant effect on drying curve, while the weir height and solid flow rate are slightly. Based on value of R2, χ2, and RMSE, Page Model is the most accurate simulation for thin layer drying model of cassava starch.

Discharge characteristics of embankment-shaped weirs

USGS Publications Warehouse

Kindsvater, Carl E.

1964-01-01

An embankment-shaped weir is an embankment overtopped by flood waters. Among the engineering problems frequently resulting from. this occurrence is the need to compute the peak discharge from postflood yield observations. The research described in this. report was concerned with the theoretical and experimental bases for the computation procedure. The research had two main objectives. One was to determine the relationship between embankment form and roughness and some of the more important discharge characteristics. The second was to define, theoretically and experimentally, the relationship between free-flow discharge and the boundary layer on the roadway. The first objective was accomplished with the experimental determination of coefficients of discharge and other significant flow characteristics for a variety of boundary and flow conditions. The second objective was accomplished with the development and experimental verification of a discharge equation which involved the boundary layer displacement thickness. This phase of the research included a general investigation of boundary layer growth on the roadway. It is included that both free- and submerged-flow discharge are virtually independent of the influence of embankment shape and relative height. The influence of boundary resistance is appreciable only for smaller heads. The most practical solution for discharge is one which is based on. the simple weir equation and experimentally determined coefficients. A completely analytical equation of discharge is impractical. The report contains the results of 936 experiments on the discharge characteristics of 17 different models; plus 106 boundary-layer velocity traverses on 4 different models. The data are summarized in both graphical and tabular form.

The neurologic content of S. Weir Mitchell's fiction.

PubMed

Louis, Elan D; Horn, Stacy; Roth, Lisa Anne

2006-02-14

Silas Weir Mitchell (1829 to 1914), one of the most important neurologists in American Medicine, was known for his seminal work on the phantom limb syndrome, causalgia, and nerve injuries. He was also a prolific writer of novels and short stories. The neurologic content of this fiction has not been studied. To assess the extent that references to neurologic topics were present in Mitchell's fiction, whether these neurologic references reflected Mitchell's scientific interests and contributions, and whether his fictional accounts of neurologic topics would precede those in his scientific writings. The authors read Silas Weir Mitchell's novels and short stories. Seventeen (63.0%) of 27 fictional works contained neurologic references. Fifty-five (69.6%) of 79 references were brief (a single word or sentence). In two works, a neurologic theme was central to the plot. Some of the neurologic content was sophisticated (aphasia, brain laterality). Phantom limb syndrome, causalgia, and nerve injuries were not prominent in his fiction. Neurologic consequences of battle injuries were featured in 10 (37.0%) works. With the exception of "The Case of George Dedlow" (i.e., phantom limb syndrome), Mitchell's fictional accounts of neurologic topics followed his presentation of these topics in the scientific literature. The majority of Mitchell's fictional works contained references to neurologic topics but most contained brief references. The number of references to Mitchell's specific scientific interests (phantom limb syndrome, causalgia) was small, although more generally, references to the neurology of battle injuries occurred more frequently.

Morphological and phylogenetic diversity of thermophilic cyanobacteria in Algerian hot springs.

PubMed

Amarouche-Yala, Samia; Benouadah, Ali; El Ouahab Bentabet, Abd; López-García, Purificación

2014-11-01

Geothermal springs in Algeria have been known since the Roman Empire. They mainly locate in Eastern Algeria and are inhabited by thermophilic organisms, which include cyanobacteria forming mats and concretions. In this work, we have investigated the cyanobacterial diversity of these springs. Cyanobacteria were collected from water, concretions and mats in nine hot springs with water temperatures ranging from 39 to 93 °C. Samples were collected for isolation in culture, microscopic morphological examination, and molecular diversity analysis based on 16S rRNA gene sequences. Nineteen different cyanobacterial morphotypes were identified, the most abundant of which were three species of Leptolyngbya, accompanied by members of the genera Gloeocapsa, Gloeocapsopsis, Stigonema, Fischerella, Synechocystis, Microcoleus, Cyanobacterium, Chroococcus and Geitlerinema. Molecular diversity analyses were in good general agreement with classical identification and allowed the detection of additional species in three springs with temperatures higher than 50 °C. They corresponded to a Synechococcus clade and to relatives of the intracellularly calcifying Candidatus Gloeomargarita lithophora. The hottest springs were dominated by members of Leptolyngbya, Synechococcus-like cyanobacteria and Gloeomargarita, whereas Oscillatoriales other than Leptolyngbya, Chroococcales and Stigonematales dominated lower temperature springs. The isolation of some of these strains sets the ground for future studies on the biology of thermophilic cyanobacteria.

Remote sensing as an aid for marsh management

NASA Technical Reports Server (NTRS)

Ragan, J. G.; Green, J. H.

1973-01-01

NASA aerial photography, primarily color infrared and color positive transparencies, is used in a study of marsh management practices and in comparing managed and unmanaged marsh areas. Weir locations for tidal control are recommended.

UV water disinfector

DOEpatents

Gadgil, A.; Garud, V.

1998-07-14

A UV disinfector with a gravity driven feed water delivery system and an air-suspended bare UV lamp are disclosed. The disinfector is hydrodynamically optimized with a laminerizing, perforated baffle wall, beveled treatment chamber, and outlet weir. 7 figs.

Silas Weir Mitchell on epilepsy therapy in the late 19th to early 20th centuries.

PubMed

Burkholder, David B; Boes, Christopher J

2014-11-01

Silas Weir Mitchell (1829-1914), one of the fathers of American neurology, is well known for many contributions to neurology. However, his efforts in epilepsy are overshadowed by his other accomplishments. Mitchell introduced a new bromide preparation, lithium bromide, as a viable therapy. His most widely accepted contribution to the field was the introduction of inhaled amyl nitrite for early termination of seizures accompanied by an appropriate aura. Despite the prevalent views on lifestyle modification as a treatment for epilepsy during this time period, as well as Mitchell's own development of the "rest cure" for certain disease states, he was not a proponent of these types of interventions for epilepsy, nor did he support interventions focused on other organ systems, such as abdominal or gynecologic surgery. Mitchell had distinct opinions on the treatment of epilepsy, and helped to advance its therapeutics during his career.

Succession of Sulfur-Oxidizing Bacteria in the Microbial Community on Corroding Concrete in Sewer Systems† ▿

PubMed Central

Okabe, Satoshi; Odagiri, Mitsunori; Ito, Tsukasa; Satoh, Hisashi

2007-01-01

Microbially induced concrete corrosion (MICC) in sewer systems has been a serious problem for a long time. A better understanding of the succession of microbial community members responsible for the production of sulfuric acid is essential for the efficient control of MICC. In this study, the succession of sulfur-oxidizing bacteria (SOB) in the bacterial community on corroding concrete in a sewer system in situ was investigated over 1 year by culture-independent 16S rRNA gene-based molecular techniques. Results revealed that at least six phylotypes of SOB species were involved in the MICC process, and the predominant SOB species shifted in the following order: Thiothrix sp., Thiobacillus plumbophilus, Thiomonas intermedia, Halothiobacillus neapolitanus, Acidiphilium acidophilum, and Acidithiobacillus thiooxidans. A. thiooxidans, a hyperacidophilic SOB, was the most dominant (accounting for 70% of EUB338-mixed probe-hybridized cells) in the heavily corroded concrete after 1 year. This succession of SOB species could be dependent on the pH of the concrete surface as well as on trophic properties (e.g., autotrophic or mixotrophic) and on the ability of the SOB to utilize different sulfur compounds (e.g., H2S, S0, and S2O32−). In addition, diverse heterotrophic bacterial species (e.g., halo-tolerant, neutrophilic, and acidophilic bacteria) were associated with these SOB. The microbial succession of these microorganisms was involved in the colonization of the concrete and the production of sulfuric acid. Furthermore, the vertical distribution of microbial community members revealed that A. thiooxidans was the most dominant throughout the heavily corroded concrete (gypsum) layer and that A. thiooxidans was most abundant at the highest surface (1.5-mm) layer and decreased logarithmically with depth because of oxygen and H2S transport limitations. This suggested that the production of sulfuric acid by A. thiooxidans occurred mainly on the concrete surface and the sulfuric acid produced penetrated through the corroded concrete layer and reacted with the sound concrete below. PMID:17142362

Optimization of an artificial-recharge-pumping system for water supply in the Maghaway Valley, Cebu, Philippines

NASA Astrophysics Data System (ADS)

Kawo, Nafyad Serre; Zhou, Yangxiao; Magalso, Ronnell; Salvacion, Lasaro

2018-05-01

A coupled simulation-optimization approach to optimize an artificial-recharge-pumping system for the water supply in the Maghaway Valley, Cebu, Philippines, is presented. The objective is to maximize the total pumping rate through a system of artificial recharge and pumping while meeting constraints such as groundwater-level drawdown and bounds on pumping rates at each well. The simulation models were coupled with groundwater management optimization to maximize production rates. Under steady-state natural conditions, the significant inflow to the aquifer comes from river leakage, whereas the natural discharge is mainly the subsurface outflow to the downstream area. Results from the steady artificial-recharge-pumping simulation model show that artificial recharge is about 20,587 m3/day and accounts for 77% of total inflow. Under transient artificial-recharge-pumping conditions, artificial recharge varies between 14,000 and 20,000 m3/day depending on the wet and dry seasons, respectively. The steady-state optimisation results show that the total optimal abstraction rate is 37,545 m3/day and artificial recharge is increased to 29,313 m3/day. The transient optimization results show that the average total optimal pumping rate is 36,969 m3/day for the current weir height. The transient optimization results for an increase in weir height by 1 and 2 m show that the average total optimal pumping rates are increased to 38,768 and 40,463 m3/day, respectively. It is concluded that the increase in the height of the weir can significantly increase the artificial recharge rate and production rate in Maghaway Valley.

1. PHOTOGRAPH TAKEN FROM THE SOUTH LOOKING NORTH ACROSS AN ...

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

1. PHOTOGRAPH TAKEN FROM THE SOUTH LOOKING NORTH ACROSS AN ERODED AREA. THE SOUTH END OF THE FLUME HAS COLLAPSED. - Davidson Ditch Waste Water Weir, Mile 63 of Alaska's Steese Highway, Chatanika, Fairbanks North Star Borough, AK

5. VIEW OF UPRIGHT OUTLET GATE, STEM, STEM GUIDE AND ...

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

5. VIEW OF UPRIGHT OUTLET GATE, STEM, STEM GUIDE AND WHEEL (10' HARDESTY CAST IRON VERTICAL LIFT GATE), LOOKING WEST - High Mountain Dams in Bonneville Unit, Weir Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

Trace elements and organic compounds in bed sediment from selected streams in southern Louisiana, 1998

USGS Publications Warehouse

Skrobialowski, Stanley C.

2002-01-01

Bed-sediment samples from 21 selected streams in southern Louisiana were collected and analyzed for the presence of trace elements and organic compounds during 1998 as part of the U.S. Geological Survey National Water-Quality Assessment Program. Concentrations of selected trace elements and organic compounds were compared on the basis of sediment-quality criteria, land use, and grain size; concentrations of selected trace elements also were compared with concentrations from previous studies. Concentrations of seven selected trace elements and 21 organic compounds were evaluated with sediment-quality criteria established by the Canadian Council of Ministers of the Environment. Concentrations of selected trace elements and organic compounds were highest at sites draining urban and agricultural areas and may result from cumulative effects of relatively high percentages of fine-grained material, iron, and organic material. Concentrations exceeding sediment-quality criteria for the protection of aquatic life occurred most frequently at Bayou Grosse Tete at Rosedale and Bayou Lafourche below weir at Thibodaux. Exceedance of Interim Sediment Quality Guidelines occurred most frequently for arsenic and chromium. Trace-element concentrations in fine-grained samples were compared with concentrations in bulk samples and were determined to be significantly different, and concentrations were generally higher in finegrained sediment. Shapiro-Wilk, paired t-test, and Wilcoxon rank sum statistical procedures, with an alpha of 0.05, were used to compare concentrations of 21 trace elements, total organic carbon, and total carbon in finegrained and bulk sediment samples for 19 sites. Significant differences were determined between fine-grained and bulk sediment samples for aluminum, barium, beryllium, chromium, copper, iron, lithium, nickel, phosphorus, selenium, titanium, and zinc concentrations. Of 133 paired concentrations, 69 percent were greater in fine-grained samples, and 23 percent were greater in bulk samples. Comparisons with data from previous studies indicate increases by more than 20 percent in concentrations of antimony at Bayou Lafourche below weir at Thibodaux, arsenic and chromium at Tickfaw River at Liverpool, lead at Bayou Lafourche below weir at Thibodaux, and zinc at Bayou Lafourche below weir at Thibodaux and Vermilion River at Perry. Historic comparisons also indicate decreases by more than 20 percent in concentrations of chromium at Bayou des Cannes near Eunice and mercury at Mermentau River at Mermentau.

The Ecology of Acidophilic Microorganisms in the Corroding Concrete Sewer Environment

PubMed Central

Li, Xuan; Kappler, Ulrike; Jiang, Guangming; Bond, Philip L.

2017-01-01

Concrete corrosion is one of the most significant problems affecting valuable sewer infrastructure on a global scale. This problem occurs in the aerobic zone of the sewer, where a layer of surface corrosion develops on the exposed concrete and the surface pH is typically lowered from around 11–10 (pristine concrete) to pH 2–4. Acidophilic microorganisms become established as biofilms within the concrete corrosion layer and enhance the loss of concrete mass. Until recently, the acidophilic community was considered to comprise relatively few species of microorganisms, however, the biodiversity of the corrosion community is now recognized as being extensive and varying from different sewer environmental conditions. The diversity of acidophiles in the corrosion communities includes chemolithoautotrophs, chemolithoheterotrophs, and chemoorganoheterotrophs. The activity of these microorganisms is strongly affected by H2S levels in the sewer gas phase, although CO2, organic matter, and iron in the corrosion layer influence this acidic ecosystem. This paper briefly presents the conditions within the sewer that lead to the development of concrete corrosion in that environment. The review focuses on the acidophilic microorganisms detected in sewer corrosion environments, and then summarizes their proposed functions and physiology, especially in relation to the corrosion process. To our knowledge, this is the first review of acidophilic corrosion microbial communities, in which, the ecology and the environmental conditions (when available) are considered. Ecological studies of sewer corrosion are limited, however, where possible, we summarize the important metabolic functions of the different acidophilic species detected in sewer concrete corrosion layers. It is evident that microbial functions in the acidic sewer corrosion environment can be linked to those occurring in the analogous acidic environments of acid mine drainage and bioleaching. PMID:28473816

The Ecology of Acidophilic Microorganisms in the Corroding Concrete Sewer Environment.

PubMed

Li, Xuan; Kappler, Ulrike; Jiang, Guangming; Bond, Philip L

2017-01-01

Concrete corrosion is one of the most significant problems affecting valuable sewer infrastructure on a global scale. This problem occurs in the aerobic zone of the sewer, where a layer of surface corrosion develops on the exposed concrete and the surface pH is typically lowered from around 11-10 (pristine concrete) to pH 2-4. Acidophilic microorganisms become established as biofilms within the concrete corrosion layer and enhance the loss of concrete mass. Until recently, the acidophilic community was considered to comprise relatively few species of microorganisms, however, the biodiversity of the corrosion community is now recognized as being extensive and varying from different sewer environmental conditions. The diversity of acidophiles in the corrosion communities includes chemolithoautotrophs, chemolithoheterotrophs, and chemoorganoheterotrophs. The activity of these microorganisms is strongly affected by H 2 S levels in the sewer gas phase, although CO 2 , organic matter, and iron in the corrosion layer influence this acidic ecosystem. This paper briefly presents the conditions within the sewer that lead to the development of concrete corrosion in that environment. The review focuses on the acidophilic microorganisms detected in sewer corrosion environments, and then summarizes their proposed functions and physiology, especially in relation to the corrosion process. To our knowledge, this is the first review of acidophilic corrosion microbial communities, in which, the ecology and the environmental conditions (when available) are considered. Ecological studies of sewer corrosion are limited, however, where possible, we summarize the important metabolic functions of the different acidophilic species detected in sewer concrete corrosion layers. It is evident that microbial functions in the acidic sewer corrosion environment can be linked to those occurring in the analogous acidic environments of acid mine drainage and bioleaching.

Experiential Learning Theory as a Guide for Effective Teaching.

ERIC Educational Resources Information Center

Murrell, Patricia H.; Claxton, Charles S.

1987-01-01

David Kolb's experiential learning theory involves a framework useful in designing courses that meet needs of diverse learners. Course designs providing systematic activities in concrete experience, reflective observations, abstract conceptualization, and active experimentation will be sensitive to students' learning styles while challenging…

Confronting Islamophobia in Education

ERIC Educational Resources Information Center

Ramarajan, Dhaya; Runell, Marcella

2007-01-01

The "Religion and Diversity Education" program of the Tanenbaum Center for Interreligious Understanding includes innovative training for elementary and high school educators on addressing religious pluralism in school. This paper highlights the program and its curricula which confront Islamophobia by teaching students concrete skills for living in…

Metagenome analyses of corroded concrete wastewater pipe biofilms reveal a complex microbial system.

PubMed

Gomez-Alvarez, Vicente; Revetta, Randy P; Santo Domingo, Jorge W

2012-06-22

Concrete corrosion of wastewater collection systems is a significant cause of deterioration and premature collapse. Failure to adequately address the deteriorating infrastructure networks threatens our environment, public health, and safety. Analysis of whole-metagenome pyrosequencing data and 16S rRNA gene clone libraries was used to determine microbial composition and functional genes associated with biomass harvested from crown (top) and invert (bottom) sections of a corroded wastewater pipe. Taxonomic and functional analysis demonstrated that approximately 90% of the total diversity was associated with the phyla Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria. The top (TP) and bottom pipe (BP) communities were different in composition, with some of the differences attributed to the abundance of sulfide-oxidizing and sulfate-reducing bacteria. Additionally, human fecal bacteria were more abundant in the BP communities. Among the functional categories, proteins involved in sulfur and nitrogen metabolism showed the most significant differences between biofilms. There was also an enrichment of genes associated with heavy metal resistance, virulence (protein secretion systems) and stress response in the TP biofilm, while a higher number of genes related to motility and chemotaxis were identified in the BP biofilm. Both biofilms contain a high number of genes associated with resistance to antibiotics and toxic compounds subsystems. The function potential of wastewater biofilms was highly diverse with level of COG diversity similar to that described for soil. On the basis of the metagenomic data, some factors that may contribute to niche differentiation were pH, aerobic conditions and availability of substrate, such as nitrogen and sulfur. The results from this study will help us better understand the genetic network and functional capability of microbial members of wastewater concrete biofilms.

Metagenome analyses of corroded concrete wastewater pipe biofilms reveal a complex microbial system

PubMed Central

2012-01-01

Background Concrete corrosion of wastewater collection systems is a significant cause of deterioration and premature collapse. Failure to adequately address the deteriorating infrastructure networks threatens our environment, public health, and safety. Analysis of whole-metagenome pyrosequencing data and 16S rRNA gene clone libraries was used to determine microbial composition and functional genes associated with biomass harvested from crown (top) and invert (bottom) sections of a corroded wastewater pipe. Results Taxonomic and functional analysis demonstrated that approximately 90% of the total diversity was associated with the phyla Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria. The top (TP) and bottom pipe (BP) communities were different in composition, with some of the differences attributed to the abundance of sulfide-oxidizing and sulfate-reducing bacteria. Additionally, human fecal bacteria were more abundant in the BP communities. Among the functional categories, proteins involved in sulfur and nitrogen metabolism showed the most significant differences between biofilms. There was also an enrichment of genes associated with heavy metal resistance, virulence (protein secretion systems) and stress response in the TP biofilm, while a higher number of genes related to motility and chemotaxis were identified in the BP biofilm. Both biofilms contain a high number of genes associated with resistance to antibiotics and toxic compounds subsystems. Conclusions The function potential of wastewater biofilms was highly diverse with level of COG diversity similar to that described for soil. On the basis of the metagenomic data, some factors that may contribute to niche differentiation were pH, aerobic conditions and availability of substrate, such as nitrogen and sulfur. The results from this study will help us better understand the genetic network and functional capability of microbial members of wastewater concrete biofilms. PMID:22727216

Unit 3, STA. 6+00 Little Conemaugh River, weirdetail Johnstown ...

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

Unit 3, STA. 6+00 Little Conemaugh River, weir-detail - Johnstown Local Flood Protection Project, Beginning on Conemaugh River approx 3.8 miles downstream from confluence of Little Conemaugh & Stony Creek Rivers at Johnstown, Johnstown, Cambria County, PA

Unit 3, STA. 6+00 Little Conemaugh River, weircontext Johnstown ...

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

Unit 3, STA. 6+00 Little Conemaugh River, weir-context - Johnstown Local Flood Protection Project, Beginning on Conemaugh River approx 3.8 miles downstream from confluence of Little Conemaugh & Stony Creek Rivers at Johnstown, Johnstown, Cambria County, PA

Remote sensing as an aid for marsh management: Lafouche parish, Louisiana. [aerial photography of Louisiana

NASA Technical Reports Server (NTRS)

Ragan, J. G.; Green, J. H.; Whitehurst, C. A.

1974-01-01

NASA aerial photography, primarily color infrared and color positive transparencies, was used in a study of marsh management practices and in comparing managed and unmanaged marsh areas. Weir locations for tidal control are recommended.

3. Photocopy of a drawing (original in the Collection of ...

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

3. Photocopy of a drawing (original in the Collection of the PL&C, Shelf 115, Drawing 63)--ca. 1847--PLAN & ELEVATION OF GREAT RIVER WALL SHOWING SLUICE WAYS AND WASTE WEIR - Northern Canal, Waste Gates, Lowell, Middlesex County, MA

DDT-treatment of rivers for eradication of Simuliidae

PubMed Central

McMahon, J. P.

1957-01-01

This article describes how to estimate the discharge of water in rivers and streams by means of weirs, current meters and floats, and how to calculate and administer doses of DDT for the treatment of simuliid-infested waters. PMID:13472410

The Paradox of Abstraction: Precision Versus Concreteness.

PubMed

Iliev, Rumen; Axelrod, Robert

2017-06-01

We introduce a novel measure of abstractness based on the amount of information of a concept computed from its position in a semantic taxonomy. We refer to this measure as precision. We propose two alternative ways to measure precision, one based on the path length from a concept to the root of the taxonomic tree, and another one based on the number of direct and indirect descendants. Since more information implies greater processing load, we hypothesize that nouns higher in precision will have a processing disadvantage in a lexical decision task. We contrast precision to concreteness, a common measure of abstractness based on the proportion of sensory-based information associated with a concept. Since concreteness facilitates cognitive processing, we predict that while both concreteness and precision are measures of abstractness, they will have opposite effects on performance. In two studies we found empirical support for our hypothesis. Precision and concreteness had opposite effects on latency and accuracy in a lexical decision task, and these opposite effects were observable while controlling for word length, word frequency, affective content and semantic diversity. Our results support the view that concepts organization includes amodal semantic structures which are independent of sensory information. They also suggest that we should distinguish between sensory-based and amount-of-information-based abstractness.

Concretions in Exhumed Channels Near Hanksville Utah: Implications for Mars

NASA Technical Reports Server (NTRS)

Clarke, Jonathan; Stoker, Carol R.

2011-01-01

The landscape near Hanksville, Utah, contains a diversity of Mars analogue features. These included segmented and inverted anatasomosing palaeochannels exhumed from the Late Jurassic Brushy Basin Member of the Morrison Formation that hosts abundant small carbonate concretions. The exhumed and inverted channels closely resemble many seen on the surface of Mars in satellite imagery and which may be visited by surface missions in the near future. The channels contain a wealth of palaeo-environmental information, but intrinsically difficult terrain would make their study challenging on Mars. We show that an unexhumed channel feature can be detected geophysically, this may allow their study in more easily accessed terrain. The concretions morphologically and in their surface expression parallel the haematite blue berries that are strewn across the surface of Meridiani Planum on Mars. They are best developed in poorly cemented medium to coarse channel sandstones and appear to have formed early in the diagenetic history.

Quantitative ultrasonic evaluation of concrete structures using one-sided access

NASA Astrophysics Data System (ADS)

Khazanovich, Lev; Hoegh, Kyle

2016-02-01

Nondestructive diagnostics of concrete structures is an important and challenging problem. A recent introduction of array ultrasonic dry point contact transducer systems offers opportunities for quantitative assessment of the subsurface condition of concrete structures, including detection of defects and inclusions. The methods described in this paper are developed for signal interpretation of shear wave impulse response time histories from multiple fixed distance transducer pairs in a self-contained ultrasonic linear array. This included generalizing Kirchoff migration-based synthetic aperture focusing technique (SAFT) reconstruction methods to handle the spatially diverse transducer pair locations, creating expanded virtual arrays with associated reconstruction methods, and creating automated reconstruction interpretation methods for reinforcement detection and stochastic flaw detection. Interpretation of the reconstruction techniques developed in this study were validated using the results of laboratory and field forensic studies. Applicability of the developed methods for solving practical engineering problems was demonstrated.

Selective nontreatment of handicapped newborns: a critical essay.

PubMed

Kohrman, A F

1985-01-01

The neonatal intensive care unit is the site of some of the most dramatic technology, complex decision-making and costly activity in the current range of medical institutions. Thus, the decisions made there are particularly visible, and of concern to a society which has increasingly scrutinized and challenged medical practices. Questions of marginal utility and cost-benefit relationships are becoming increasingly prominent. These concerns are heightened by the social and political tensions over issues of the time of initiation of life, quality of life, and assurances of equity for those less well off or handicapped from birth. Robert Weir's book, Selective Nontreatment of Handicapped Newborns, successfully summarizes the current dilemmas and identifies areas of uncertainty and lack of knowledge which cloud the decision-making processes. The book reviews the positions of the major protagonists of the last several years; inevitably, their positions will undergo continuous evolution in response to new data and vigorous political and public policy activity. Weir appropriately identifies the difficulty in arriving at an accurate prognosis as an important and prominent problem in decision-making about defective newborns. The population of surviving, compromised newborns is relatively unfamiliar and their problems remain largely unstudied. Weir's discussion of the desirability of the establishment of Infant Care Review Committees in those institutions which care for defective and handicapped newborns thoughtfully concludes that such committees are, on the balance, desirable. As experience accumulates with Infant Care Review Committees, they should serve the positive purpose of generating open discussion of legitimate disagreements. These committees will provide a forum in which decision-makers can disclose uncertainty, consider alternatives, and receive counsel.(ABSTRACT TRUNCATED AT 250 WORDS)

Interfaith Leaders as Social Entrepreneurs

ERIC Educational Resources Information Center

Patel, Eboo; Meyer, Cassie

2012-01-01

Social entrepreneurs work to find concrete solutions to large-scale problems that are scalable and sustainable. In this article, the authors explore what the framework of social entrepreneurship might offer those seeking to positively engage religious diversity on college campuses, and highlight two programs that offer examples of what such…

Electronic tags and genetics explore variation in migrating steelhead kelts (oncorhynchus mykiss), Ninilchik river, Alaska

USGS Publications Warehouse

Nielsen, J.L.; Turner, S.M.; Zimmerman, C.E.

2011-01-01

Acoustic and archival tags examined freshwater and marine migrations of postspawn steelhead kelts (Oncorhynchus mykiss) in the Ninilchik River, Alaska, USA. Postspawn steelhead were captured at a weir in 2002-2005. Scale analysis indicated multiple migratory life histories and spawning behaviors. Acoustic tags were implanted in 99 kelts (2002-2003), and an array of acoustic receivers calculated the average speed of outmigration, timing of saltwater entry, and duration of residency in the vicinity of the river mouth. Ocean migration data were recovered from two archival tags implanted in kelts in 2004 (one male and one female). Archival tags documented seasonal differences in maximum depth and behavior with both fish spending 97% of time at sea <6 m depth (day and night). All study fish were double tagged with passive integrated transponder (PIT) tags implanted in the body cavity. Less than 4% of PIT tags were retained in postspawn steelhead. Molecular genetics demonstrated no significant differences in genetic population structure across years or among spawning life history types, suggesting a genetically panmictic population with highly diverse life history characteristics in the Ninilchik River.

Design procedures and field monitoring of submerged barbs for streambank protection.

DOT National Transportation Integrated Search

2007-06-01

The main objective of this study was to evaluate the hydraulic performance of riprap spurs and weirs in controlling bank erosion at : the Southern part of the Raccoon River upstream U.S. Highway 169 Bridge utilizing the commercially available model F...

2. PHOTOGRAPH TAKEN FROM NORTH SIDE OF DAVIDSON DITCH LOOKING ...

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

2. PHOTOGRAPH TAKEN FROM NORTH SIDE OF DAVIDSON DITCH LOOKING SOUTH ALONG LENGTH OF FLUME--VEGETATION NOT REMOVED AS PER ALASKA DEPARTMENT OF TRANSPORTATION PERSONNEL. - Davidson Ditch Waste Water Weir, Mile 63 of Alaska's Steese Highway, Chatanika, Fairbanks North Star Borough, AK

Dynamic Interactions for Network Visualization and Simulation

DTIC Science & Technology

2009-03-01

projects.htm, Site accessed January 5, 2009. 12. John S. Weir, Major, USAF, Mediated User-Simulator Interactive Command with Visualization ( MUSIC -V). Master’s...Computing Sciences in Colleges, December 2005). 14. Enrique Campos -Nanez, “nscript user manual,” Department of System Engineer- ing University of

Mindblindness: metaphor and neuroaesthetics in the works of Silas Weir Mitchell and Simon Baron-Cohen.

PubMed

Swenson, Kristine

2013-01-01

Silas Weir Mitchell's novel, When All the Woods are Green (1894), acknowledges the medical use of mindblindness (agnosia) but also casts it as a developmental disorder, bringing it provocatively close to how current neuropsychologist, Simon Baron-Cohen and his followers use the term in relation to autism. This chapter traces the mindblindess metaphor in the works of Mitchell and Baron-Cohen to show how mindblindness informs the larger paradigms by which they theorize the brain. This analysis suggests that Baron-Cohen, and thus much current thinking about autism spectrum conditions, is influenced by Victorian-era cultural assumptions and neurosexism, a connection that calls for scrutiny of Baron-Cohen's current models of the brain and theories of autism. This chapter also demonstrates the extent to which Mitchell used fiction and advocated writing as neuroaesthetic tools and thus bridged in his work cognitive science and aesthetics--a connection that current scholars of neuroaesthetics are now theorizing. © 2013 Elsevier B.V. All rights reserved.

Evaluating Use of Environmental Flows to Aerate Streams by Modelling the Counterfactual Case.

PubMed

Stewardson, Michael J; Skinner, Dominic

2018-03-01

This paper evaluates an experimental environmental flow manipulation by modeling the counterfactual case that no environmental flow was applied. This is an alternate approach to evaluating the effect of an environmental flow intervention when a before-after or control-impact comparison is not possible. In this case, the flow manipulation is a minimum flow designed to prevent hypoxia in a weir on the low-gradient Broken Creek in south-eastern Australia. At low flows, low reaeration rates and high respiration rates associated with elevated organic matter loading in the weir pool can lead to a decline in dissolved oxygen concentrations with adverse consequences both for water chemistry and aquatic biota. Using a one dimensional oxygen balance model fitted to field measurements, this paper demonstrates that increased flow leads to increases in reaeration rates, presumably because of enhanced turbulence and hence mixing in the surface layers. By comparing the observed dissolved oxygen levels with the modeled counterfactual case, we show that the environmental flow was effective in preventing hypoxia.

Evaluating Use of Environmental Flows to Aerate Streams by Modelling the Counterfactual Case

NASA Astrophysics Data System (ADS)

Stewardson, Michael J.; Skinner, Dominic

2018-03-01

This paper evaluates an experimental environmental flow manipulation by modeling the counterfactual case that no environmental flow was applied. This is an alternate approach to evaluating the effect of an environmental flow intervention when a before-after or control-impact comparison is not possible. In this case, the flow manipulation is a minimum flow designed to prevent hypoxia in a weir on the low-gradient Broken Creek in south-eastern Australia. At low flows, low reaeration rates and high respiration rates associated with elevated organic matter loading in the weir pool can lead to a decline in dissolved oxygen concentrations with adverse consequences both for water chemistry and aquatic biota. Using a one dimensional oxygen balance model fitted to field measurements, this paper demonstrates that increased flow leads to increases in reaeration rates, presumably because of enhanced turbulence and hence mixing in the surface layers. By comparing the observed dissolved oxygen levels with the modeled counterfactual case, we show that the environmental flow was effective in preventing hypoxia.

SPH simulation of free surface flow over a sharp-crested weir

NASA Astrophysics Data System (ADS)

Ferrari, Angela

2010-03-01

In this paper the numerical simulation of a free surface flow over a sharp-crested weir is presented. Since in this case the usual shallow water assumptions are not satisfied, we propose to solve the problem using the full weakly compressible Navier-Stokes equations with the Tait equation of state for water. The numerical method used consists of the new meshless Smooth Particle Hydrodynamics (SPH) formulation proposed by Ferrari et al. (2009) [8], that accurately tracks the free surface profile and provides monotone pressure fields. Thus, the unsteady evolution of the complex moving material interface (free surface) can been properly solved. The simulations involving about half a million of fluid particles have been run in parallel on two of the most powerful High Performance Computing (HPC) facilities in Europe. The validation of the results has been carried out analysing the pressure field and comparing the free surface profiles obtained with the SPH scheme with experimental measurements available in literature [18]. A very good quantitative agreement has been obtained.

Civil war medicine from the perspective of S. Weir Mitchell's "The case of George Dedlow".

PubMed

Canale, D J

2002-03-01

In 1866, a year following the close of the American Civil War, an anonymous article arousing much public interest appeared in the popular magazine, The Atlantic Monthly. The real author, Silas Weir Mitchell, who became one of America's most distinguished neurologists, wrote this short story early in his career while serving as a contract army surgeon and conducting his important clinical researches in nerve injuries. This article was the first literary effort in his long and prolific career as a physician/writer. Historians citing this article have focused almost exclusively on the early descriptions of causalgia and phantom limb syndrome, appearing as it did in a popular magazine. The present author proposes to show, for the first time, that Mitchell actually intended to describe many important medical consequences of the American Civil War, which was later shown to have so profoundly affected him throughout his medical and literary career. He cleverly accomplished this through the narration of Assistant Surgeon George Dedlow, who loses all four extremities by amputation.

Gender in the Management Education Classroom: A Collaborative Learning Journey

ERIC Educational Resources Information Center

Bilimoria, Diana; O'Neil, Deborah A.; Hopkins, Margaret M.; Murphy, Verena

2010-01-01

In this article, the authors describe a classroom incident and their subsequent learnings about effectively managing issues of gender diversity in an MBA course titled "Women in Organizations." The authors employ Kolb's learning cycle as a framework for describing the incident ("concrete experience"), reflecting on and discussing what occurred…

Critical Thinking in Adulthood.

ERIC Educational Resources Information Center

Fulton, Rodney D.

Critical thinking is often defined as that which a particular instrument measures. The most prominent tests are the Watson-Glaser Critical Thinking Appraisal, the Ennis-Weir Critical Thinking Essay Test, and the Cornell Critical Thinking Tests. Watson and Glaser's (1980) view of critical thinking is "a composite of attitudes, knowledge, and…

Examining assortativity in the mental lexicon: Evidence from word associations.

PubMed

Van Rensbergen, Bram; Storms, Gert; De Deyne, Simon

2015-12-01

Words are characterized by a variety of lexical and psychological properties, such as their part of speech, word-frequency, concreteness, or affectivity. In this study, we examine how these properties relate to a word's connectivity in the mental lexicon, the structure containing a person's knowledge of words. In particular, we examine the extent to which these properties display assortative mixing, that is, the extent to which words in the lexicon are more likely to be connected to words that share these properties. We investigated three types of word properties: 1) subjective word covariates: valence, dominance, arousal, and concreteness; 2) lexical information: part of speech; and 3) distributional word properties: age-of-acquisition, word frequency, and contextual diversity. We assessed which of these factors exhibit assortativity using a word association task, where the probability of producing a certain response to a cue is a measure of the associative strength between the cue and response in the mental lexicon. Our results show that the extent to which these aspects exhibit assortativity varies considerably, with a high cue-response correspondence on valence, dominance, arousal, concreteness, and part of speech, indicating that these factors correspond to the words people deem as related. In contrast, we find that cues and responses show only little correspondence on word frequency, contextual diversity, and age-of-acquisition, indicating that, compared to subjective and lexical word covariates, distributional properties exhibit only little assortativity in the mental lexicon. Possible theoretical accounts and implications of these findings are discussed.

Pine dwarfmistletoe on the Pringle Falls Experimental Forest.

Treesearch

L.F. Roth

1953-01-01

Dwarfmistletoe (Arceuthobium campylopodum forma typicum (Engelm.) Gill) is widespread in the ponderosa pine forests of Oregon and Washington. The importance of dwarfmistletoe as a damaging agent in the pine forest of the Pacific Northwest was described by Weir in 1916. In some localities present infestations are so heavy that...

ADULT COHO SALMON AND STEELHEAD USE OF BOULDER WEIRS IN SOUTHWEST OREGON STREAMS

EPA Science Inventory

The placement of log and boulder structures in streams is a common and often effective technique for improving juvenile salmonid rearing habitat and increasing fish densities. Less frequently examined has been the use of these structures by adult salmonids. In 2004, spawner densi...

50 CFR 36.39 - Public use.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., and Swanson Lakes are only open for sport ice fishing. Andy Simons Unit Emerald Lake Green Lake Harvey..., waysides, buildings or the Sterling Highway from the east refuge boundary to the east junction of the... buildings, piers, docks, weirs, refuge offices, visitor centers, and public access and parking sites. Maps...

Decreasing nitrate-N loads to coastal ecosystems with innovative drainage management strategies in agricultural landscapes: An experimental approach

USDA-ARS?s Scientific Manuscript database

Controlled drainage in agricultural ditches contributes to a drainage management strategy with potential environmental and production benefits. Innovative drainage strategies including spatially orientated low-grade weirs show promise to significantly improve nutrient (e.g. nitrate-N) reductions by...

Evidence for the use of low-grade weirs in drainage ditches to improve nutrient reductions from agriculture

USDA-ARS?s Scientific Manuscript database

The essential function of drainage ditches is to remove water from the agricultural landscape to avoid crop senescence through flooding and soil saturation. Commonly used slotted board risers provide drainage management strategies over the dormant season; however, by introducing innovative, low-gra...

Computational fluid dynamics characterization of a novel mixed cell raceway design

USDA-ARS?s Scientific Manuscript database

Computational fluid dynamics (CFD) analysis was performed on a new type of mixed cell raceway (MCR) that incorporates longitudinal plug flow using inlet and outlet weirs for the primary fraction of the total flow. As opposed to regular MCR wherein vortices are entirely characterized by the boundary ...

Electromagnetic Characterization of Materials Using a Dual Chambered High Temperature Waveguide

DTIC Science & Technology

to just one day through simultaneous measurement of the sample and the empty second chamber. A vector network analyzer (VNA) will be used to run X-band...calculated from the Nicolson-Ross-Weir inversion algorithm for computing permittivity and permeability using VNA measured S-parameters at increasing temperatures.

Hydraulics of embankment-dam breaching

NASA Astrophysics Data System (ADS)

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

2012-12-01

Constructed or natural earthen dams can pose hazards to downstream communities. Experiments to date on earthen-dam breaching have focused on dam geometries relevant to engineering practice. We have begun experiments with dam geometries more like those of natural dams. Water was impounded behind dams constructed at the downstream end of the USGS debris-flow flume. Dams were made of compacted, well-sorted, moist beach sand (D50=0.21 mm), 3.5 m from toe to toe, but varying in height from 0.5 to 1 m; the lower the dam, the smaller the reservoir volume and the broader the initially flat crest. Breaching was started by cutting a slot 30-40 mm wide and deep in the dam crest after filling the reservoir. Water level and pore pressure within the dam were monitored. Experiments were also recorded by an array of still- and video cameras above the flume and a submerged video camera pointed at the upstream dam face. Photogrammetric software was used to create DEMs from stereo pairs, and particle-image velocimetry was used to compute the surface-velocity field from the motion of tracers scattered on the water surface. As noted by others, breaching involves formation and migration of a knickpoint (or several). Once the knickpoint reaches the upstream dam face, it takes on an arcuate form whose continued migration we determined by measuring the onset of motion of colored markers on the dam face. The arcuate feature, which can be considered the head of the "breach channel", is nearly coincident with the transition from subcritical to supercritical flow; that is, it acts as a weir that hydraulically controls reservoir emptying. Photogenic slope failures farther downstream, although the morphologically dominant process at work, play no role at all in hydraulic control aside from rare instances in which they extend upstream so far as to perturb the weir, where the flow cross section is nearly self-similar through time. The domain downstream of the critical-flow section does influence the hydrograph in another way: the broader the initial dam crest, the longer the time before critical flow control is established. Flood duration is thus increased but peak discharge is decreased. Visual inspection and overhead videography reveal little turbidity in water pouring over the weir, implying that sediment there moves dominantly as bedload. Furthermore, underwater videography gives the overall impression that along the upstream dam face, erosion occurs without redeposition. Thus it would be a mistake to use empiricisms for equilibrium bedload transport to model erosion of the embankment. In mathematical terms, erosion rate cannot be backed out by calculating the divergence of transport rate; rather, transport rate should be regarded as the spatial integral of erosion rate. We use photogrammetry and motion of the colored markers to determine the erosion rate of the weir, and then infer shear stress at the weir by applying the van Rijn sediment-pickup function. Shear stress determined in this fashion is much less than what one calculates from the gradient of the energy head (an approach appropriate to steady flow). Shear stress inferred from the pickup-function calculation can serve as a constraint on computational fluid-dynamics models. Another constraint on such models, revealed by the underwater videography, is the upstream limit of sand movement, where bed shear stress equals the critical value for sand entrainment.

Cultura, Identidad y Aprendizaje en la Edad Pre-escolar.

ERIC Educational Resources Information Center

Engelbrecht, Guillermina; Moyer, Joan

1987-01-01

Maintains that it is not the volume of information about diverse groups that will help children develop attitudes of respect and appreciation of differences; rather, it is the skill of processing such information in a positive manner. Concrete examples illustrate the different process skills which should be introduced in school. (Author/BB)

Baby Basics: Children's Activities in How Life Begins. Children's Activity Series.

ERIC Educational Resources Information Center

Picco, Elizabeth Raptis

These supplemental teaching resources promote awareness about health, family life, and cultural diversity for children in kindergarten through third grade, and offer a variety of concrete, visual activities to help young children understand how life begins for all living things. The format of each lesson is designed to help classroom and daycare…

Organization Development: Its Nature, Origins, and Prospects.

ERIC Educational Resources Information Center

Bennis, Warren G.

A primer on organization development (OD), this book presents a basic statement for people in organizations and for practitioners and students of OD. Many concrete examples are included. After a definition of OD, the basic conditions which create the need for OD are discussed: rapid change, growth in size, increasing diversity, change in…

No Light at the End of Tunnel Vision: Steps for Improving Lesson Plans

ERIC Educational Resources Information Center

Dunn, Rita; Craig, Martin; Favre, Lois; Markus, Doron; Pedota, Paul; Sookdeo, Gale; Stock, Jessica; Terry, Brian

2010-01-01

The authors of this article believe that the current structure of lesson plans impede differentiation, individualization, and innovation and offer little in assessing the quality of teaching and learning. Concrete steps will be offered for planning to better respond to student diversity in meeting lesson objectives. (Contains 1 figure.)

Youth at Risk: A Prevention Resource for Counselors, Teachers, and Parents. Fourth Edition.

ERIC Educational Resources Information Center

Capuzzi, David, Ed.; Gross, Douglas R., Ed.

The fourth revision of this text offers both tested prevention strategies for work with diverse at-risk populations and counseling techniques that address the complexities of destructive behavior from individual, family, school, and community perspectives. Drawing on the wisdom of 24 experts, this book provides concrete advice for creating and…

LJUBLJANICA CONNECTS - Restoration of the Ljubljanica River corridor and improvement of the river's flow regime

NASA Astrophysics Data System (ADS)

Zabret, Katarina; Sapač, Klaudija; Šraj, Mojca; Bezak, Nejc; Sečnik, Matej; Vidmar, Andrej; Brilly, Mitja

2016-04-01

The project Ljubljanica connects is focused on improving connectivity and living conditions in Ljubljanica River which flows through capital city of Slovenia, Ljubljana. It represents living environment for endangered and Natura 2000 targeted fish species Danube Salmon (Hucho hucho), Danube Roach (Rutilus pigus) and Striped Chub (Leuciscus souffia). The project consists of four sets of activities: concrete restoration actions including improvement of two fish passes, monitoring of fish migration, monitoring of eco-hydrological parameters, and raising of public awareness. To improve living conditions the concrete restoration measures were performed. The reconstructions of sill and two fish passes on the Ljubljanica River have been implemented and barrier's lifting system on the weir was modernized. Above the sill in Zalog there is an oxbow which was disconnected with main river channel during the low flows. Interrupted inflow of fresh water caused very poor living conditions for animals in the oxbow. The raise of the sill helped to improve this situation. One of the fish passes included in the project is more than 100 years old whereas both are protected as cultural and technical heritage. None was working properly and due to the protection no visible nor drastic measures were allowed. With smaller improvements we managed to re-establish their operation. A lifting system of the barrier at the Ambrožev trg gate was outdated and did not allow precise regulation of the water level. Too fast raising of the barrier instantly caused deterioration of eco-hydrological conditions downstream. With modernization of the electromechanical equipment the situation is improved. The fish monitoring helps us to evaluate success of concrete restoration actions. The fish population status is monitored with marking the fish with Visible Implant Elastomer (VIE) tags. Regarding the location of catch we implant tags beneath transparent or translucent tissue combining different tag locations (dorsal fin, post ocular tissue) and colours (red, yellow). The success of restoration of fish passes is monitored with the use of on line connected cameras installed in the fish passes. Records from the camera are analysed to evaluate number and type of fish using the fish passes. For further evaluation of living conditions the eco-hydrological monitoring of water temperature, its level, and oxygen concentration is continuously implemented on 17 measurement stations. Occasionally near those permanent measurement stations we also measure the discharge. On a few locations temperature was additionally measured also with optical cable. We would like to present our activities and results of the project to a broader public so that they would be aware of what is happening around them. One of the most popular activities are thematic presentations and field workshops for school children and students.

Harnessing Natural Recovery Processes to Improve Restoration Outcomes: An Experimental Assessment of Sponge-Mediated Coral Reef Restoration

PubMed Central

Biggs, Brendan C.

2013-01-01

Background Restoration is increasingly implemented to reestablish habitat structure and function following physical anthropogenic disturbance, but scientific knowledge of effectiveness of methods lags behind demand for guidelines. On coral reefs, recovery is largely dependent on coral reestablishment, and substratum stability is critical to the survival of coral fragments and recruits. Concrete is often used to immobilize rubble, but its ecological performance has not been rigorously evaluated, and restoration has generally fallen short of returning degraded habitat to pre-disturbance conditions. Fragments of erect branching sponges mediate reef recovery by facilitating rubble consolidation, yet such natural processes have been largely overlooked in restoring reefs. Methods On two reefs in Curacao, four treatments - coral rubble alone, rubble seeded with sponge fragments, rubble bound by concrete, and concrete “rubble” bound by concrete - were monitored over four years to investigate rubble consolidation with and without sponges and the ecological performance of treatments in terms of the number and diversity of coral recruits. Species specific rates of sponge fragment attachment to rubble, donor sponge growth and tissue replacement, and fragment survival inside rubble piles were also investigated to evaluate sponge species performance and determine rates for sustainably harvesting tissue. Findings/Significance Rubble piles seeded with sponges retained height and shape to a significantly greater degree, lost fewer replicates to water motion, and were significantly more likely to be consolidated over time than rubble alone. Significantly more corals recruited to sponge-seeded rubble than to all other treatments. Coral diversity was also greatest for rubble with sponges and it was the only treatment to which framework building corals recruited. Differences in overall sponge species performance suggest species selection is important to consider. Employing organisms that jump start successional pathways and facilitate recovery can significantly improve restoration outcomes; however, best practices require techniques be tailored to each system. PMID:23750219

Eco-engineered rock pools: a concrete solution to biodiversity loss and urban sprawl in the marine environment

NASA Astrophysics Data System (ADS)

Firth, Louise B.; Browne, Keith A.; Knights, Antony M.; Hawkins, Stephen J.; Nash, Róisín

2016-09-01

In coastal habitats artificial structures typically support lower biodiversity and can support greater numbers of non-native and opportunistic species than natural rocky reefs. Eco-engineering experiments are typically trialed to succeed; but arguably as much is learnt from failure than from success. Our goal was to trial a generic, cost effective, eco-engineering technique that could be incorporated into rock armouring anywhere in the world. Artificial rock pools were created from manipulated concrete between boulders on the exposed and sheltered sides of a causeway. Experimental treatments were installed in locations where they were expected to fail and compared to controls installed in locations in which they were expected to succeed. Control pools were created lower on the structure where they were immersed on every tidal cycle; experimental pools were created above mean high water spring tide which were only immersed on spring tides. We hypothesised that lower and exposed pools would support significantly higher taxon and functional diversity than upper and sheltered pools. The concrete pools survived the severe winter storms of 2013/14. After 12 months, non-destructive sampling revealed significantly higher mean taxon and functional richness in lower pools than upper pools on the exposed side only. After 24 months the sheltered pools had become inundated with sediments, thus failing to function as rock pools as intended. Destructive sampling on the exposed side revealed significantly higher mean functional richness in lower than upper pools. However, a surprisingly high number of taxa colonised the upper pools leading to no significant difference in mean taxon richness among shore heights. A high number of rare taxa in the lower pools led to total taxon richness being almost twice that of upper pools. These findings highlight that even when expected to fail concrete pools supported diverse assemblages, thus representing an affordable, replicable means of enhancing biodiversity on a variety of artificial structures.

Dujiangyan: Could the ancient hydraulic engineering be a sustainable solution for Mississippi River diversions?

NASA Astrophysics Data System (ADS)

Xu, Y. J.

2016-02-01

Dujiangyan, also known as the Dujiangyan Project, is a hydraulic engineering complex built more than 2260 years ago on the Mingjiang River near Chengdu in China's Sichuan Province. The complex splits the river into two channels, a so-called "inner river" (Leijiang) and an "outer river" (Waijiang) that carry variable water volumes and sediment loads under different river flow conditions. The inner river and its numerous distributary canals are primarily man-made for irrigation over the past 2000 years, while the outer river is the natural channel and flows southward before entering into the Yangtze River. Under normal flow, 60% of the Mingjiang River goes into the inner river for irrigating nearly 1 million hectares of agricultural land on the Chengdu plain. During floods, however, less than 40% of the Mingjiang River flows into the inner river. Under both flow conditions, about 80% of the riverine sediments is carried by the outer river and continues downstream. This hydrology is achieved through a weir work complex that comprises three major components: a V-shaped bypass dike in the center of the Mingjiang River (the Yuzui Bypass Dike, see photo below), a sediment diversion canal in the inner river below the bypass dike (the Feishayan Floodgate), and a flow control in the inner river below the sediment diversion canal (the Baopingkou Diversion Passage). Together with ancillary embankments, these structures have not only ensured a regular supply of silt-reduced water to the fertile Chengdu plain, but have provided great benefits in flood control, sediment transport, and water resources regulation over the past two thousand years. The design of this ancient hydraulic complex ingeniously conforms to the natural environment while incorporating many sophisticated techniques, reflecting the concept that humankind is an integral part of nature. As we are urgently seeking solutions today to save the sinking Mississippi River Delta, examination of the ancient engineering marvel may offer insights into sustainable practices in river engineering of the lower Mississippi under climate change and sea level rise. This paper will introduce the Dujiangyan Project and will discuss possibilities of applying Dujiangyan's fundamental concept for sediment diversions in the Lower Mississippi River.

Balanced improvement of high performance concrete material properties with modified graphite nanomaterials

NASA Astrophysics Data System (ADS)

Peyvandi, Amirpasha

Graphite nanomaterials offer distinct features for effective reinforcement of cementitious matrices in the pre-crack and post-crack ranges of behavior. Thoroughly dispersed and well-bonded nanomaterials provide for effective control of the size and propagation of defects (microcracks) in matrix, and also act as closely spaced barriers against diffusion of moisture and aggressive solutions into concrete. Modified graphite nanomaterials can play multi-faceted roles towards enhancing the mechanical, physical and functional attributes of concrete materials. Graphite nanoplatelets (GP) and carbon nanofibers (CNF) were chosen for use in cementitious materials. Experimental results highlighted the balanced gains in diverse engineering properties of high-performance concrete realized by introduction of graphite nanomaterials. Nuclear Magnetic Resonance (NMR) spectroscopy was used in order to gain further insight into the effects of nanomaterials on the hydration process and structure of cement hydrates. NMR exploits the magnetic properties of certain atomic nuclei, and the sensitivity of these properties to local environments to generate data which enables determination of the internal structure, reaction state, and chemical environment of molecules and bulk materials. 27 Al and 29Si NMR spectroscopy techniques were employed in order to evaluate the effects of graphite nanoplatelets on the structure of cement hydrates, and their resistance to alkali-silica reaction (ASR), chloride ion diffusion, and sulfate attack. Results of 29Si NMR spectroscopy indicated that the percent condensation of C-S-H in cementitious paste was lowered in the presence of nanoplatelets at the same age. The extent of chloride diffusion was assessed indirectly by detecting Friedel's salt as a reaction product of chloride ions with aluminum-bearing cement hydrates. Graphite nanoplatelets were found to significantly reduce the concentration of Friedel's salt at different depths after various periods of exposure to chloride solutions, pointing at the benefits of nanoplatelets towards enhancement of concrete resistance to chloride ion diffusion. It was also found that the intensity of Thaumasite, a key species marking sulfate attack on cement hydrates, was lowered with the addition of graphite nanoplatelets in concrete exposed to sulfate solutions. Experimental evaluations were conducted on scaled-up production of concrete nanocomposite in precast concrete plants. Full-scale reinforced concrete pipes and beams were produced using concrete nanocomposites. Durability and structural tests indicated that the use of graphite nanoplatelets, alone or in combination with synthetic (PVA) fibers, produced significant gains in the durability characteristics, and also benefited the structural performance of precast reinforced concrete products. The material and scaled-up structural investigations conducted in the project concluded that lower-cost graphite nanomaterials (e.g., graphite nanoplatelets) offer significant potentials as multi-functional additives capable of enhancing the barrier, durability and mechanical performance of concrete materials. The benefits of graphite nanomaterials tend to be more pronounced in higher-performance concrete materials.

Biodeterioration of the Cement Composites

NASA Astrophysics Data System (ADS)

Luptáková, Alena; Eštoková, Adriana; Mačingová, Eva; Kovalčíková, Martina; Jenčárová, Jana

2016-10-01

The destruction of natural and synthetic materials is the spontaneous and irreversible process of the elements cycling in nature. It can by accelerated or decelerated by physical, chemical and biological influences. Biological influences are represented by the influence of the vegetation and microorganisms (MO). The destruction of cement composites by different MO through the diverse mechanisms is entitled as the concrete biodeterioration. Several sulphur compounds and species of MO are involved in this complex process. Heterotrophic and chemolithotrophic bacteria together with fungi have all been found in samples of corroding cement composites. The MO involved in the process metabolise the presented sulphur compounds (hydrogen sulphide, elemental sulphur etc.) to sulphuric acid reacting with concrete. When sulphuric acid reacts with a concrete matrix, the first step involves a reaction between the acid and the calcium hydroxide forming calcium sulphate. This is subsequently hydrated to form gypsum, the appearance of which on the surface of concrete pipes takes the form of a white, mushy substance which has no cohesive properties. In the continuing attack, the gypsum would react with the calcium aluminate hydrate to form ettringite, an expansive product. The use supplementary cementing composite materials have been reported to improve the resistance of concrete to biodeterioration. The aim of this work was the study of the cement composites biodeterioration by the bacteria Acidithiobacillus thiooxidans. Experimental works were focused on the comparison of special cement composites and its resistance affected by the activities of used sulphur-oxidising

On Characterizing Particle Shape

NASA Technical Reports Server (NTRS)

Ennis, Bryan J.; Rickman, Douglas; Rollins, A. Brent; Ennis, Brandon

2014-01-01

It is well known that particle shape affects flow characteristics of granular materials, as well as a variety of other solids processing issues such as compaction, rheology, filtration and other two-phase flow problems. The impact of shape crosses many diverse and commercially important applications, including pharmaceuticals, civil engineering, metallurgy, health, and food processing. Two applications studied here include the dry solids flow of lunar simulants (e.g. JSC-1, NU-LHT-2M, OB-1), and the flow properties of wet concrete, including final compressive strength. A multi-dimensional generalized, engineering method to quantitatively characterize particle shapes has been developed, applicable to both single particle orientation and multi-particle assemblies. The two-dimension, three dimension inversion problem is also treated, and the application of these methods to DEM model particles will be discussed. In the case of lunar simulants, flow properties of six lunar simulants have been measured, and the impact of particle shape on flowability - as characterized by the shape method developed here -- is discussed, especially in the context of three simulants of similar size range. In the context of concrete processing, concrete construction is a major contributor to greenhouse gas production, of which the major contributor is cement binding loading. Any optimization in concrete rheology and packing that can reduce cement loading and improve strength loading can also reduce currently required construction safety factors. The characterization approach here is also demonstrated for the impact of rock aggregate shape on concrete slump rheology and dry compressive strength.

Use of vegetated drainage ditches and low-grade weirs for aquaculture effluent mitigation: II. Suspended sediment

USDA-ARS?s Scientific Manuscript database

Total suspended solids are a priority pollutant under the Clean Water Act and a point of concern for aquaculture facilities. The use of ubiquitous vegetated ditches on the aquaculture landscape may serve as an environmentally and economically sustainable practice for reducing suspended sediment cont...

The Genesis of Language: A Psycholinguistic Approach.

ERIC Educational Resources Information Center

Smith, Frank, Ed.; Miller, George A., Ed.

The fourteen papers are: "Developmental Psycholinguistics," by David McNeill; "Comments on 'Developmental Psycholinguistics'," by Dan I. Slobin; "How to Learn to Talk: Some Simple Ways," by Jerry A. Fodor; "The Acquisition of Russian as a Native Language, " by Dan I. Slobin; "Some Questions on the Child's Learning of Phonology," by Ruth H. Weir;…

Field and laboratory calibration of impact plates for measuring coarse bed load transport

USDA-ARS?s Scientific Manuscript database

During 2008-2009, an array of impact plates instrumented with either accelerometers or geophones was installed over a channel spanning weir in the Elwha River in Washington, USA. The impact system is the first permanent installation of its kind in North America. The system was deployed to measure th...

Supporting Students with Intellectual and Developmental Disabilities to Attend College

ERIC Educational Resources Information Center

Griffin, Megan M.; Papay, Clare K.

2017-01-01

Students with intellectual and developmental disabilities (IDD), such as autism spectrum disorder and Down syndrome, have more opportunities to go to college than ever before (Hart, Grigal, & Weir, 2010). Over the last decade, the issue of increasing access to college for students with IDD has gained much national attention, in part due to…

36 CFR 13.1 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... shall apply to all regulations contained in this part: Aircraft means a machine or device that is used... means to wear, bear or carry on or about the person and additionally, in the case of firearms, within or... Preserve. Net means a seine, weir, net wire, fish trap, or other implement designed to entrap fish, except...

9. SOUTHERLY VIEW OF THE ACCESS ROAD TO THE DOWNSTREAM ...

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

9. SOUTHERLY VIEW OF THE ACCESS ROAD TO THE DOWNSTREAM SIDE OF BIG DALTON DAM EXTENDING FROM THE DAM TO THE FOOTBRIDGE. VIEW FROM BIG DALTON DAM SHOWING THE TOE WEIR IN FOREGROUND AND FOOTBRIDGE IN BACKGROUND. - Big Dalton Dam, 2600 Big Dalton Canyon Road, Glendora, Los Angeles County, CA

77 FR 6555 - Alaska Village Electric Cooperative; Notice of Preliminary Permit Application Accepted for Filing...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-08

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13272-002] Alaska Village..., Motions To Intervene, and Competing Applications On January 3, 2012, Alaska Village Electric Cooperative... the stream bed. The weir would not create any significant impoundment of water and would only be high...

An accurate and stable nitrate-selective electrode for the in situ determination of nitrate in agricultural drainage waters.

PubMed

Le Goff, Thierry; Braven, Jim; Ebdon, Les; Chilcottt, Neil P; Scholefield, David; Wood, John W

2002-04-01

A field evaluation of a novel nitrate-ion selective electrode (ISE) was undertaken by continuous immersion over a period of 5 months in agricultural drainage weirs. The nitrate sensor N,N,N-triallyl leucine betaine was covalently attached to polystyrene-block-polybutadiene-block-polystyrene (SBS) using a free radical initiated co-polymerisation, to produce a rubbery membrane which was incorporated into a commercially available electrode body. A measurement unit was constructed comprising the nitrate-ISEs, a reference electrode and a temperature probe connected through a pre-amplifier to a data-logger and battery supply. A temperature correction algorithm was developed to accomodate the temperature changes encountered in the drainage weirs. The nitrate results obtained with the ISEs at hourly intervals compared very favourably (R2 = 0.99) with those obtained with laboratory automated chemical determinations made on contemporaneous samples of drainage in a concentration range 0.47-16 ppm nitrate-N. The ISEs did not require re-calibration and no deterioration in performance or fouling of the membrane surface was observed over four months of deployment.

Removal of CO2 in a multistage fluidized bed reactor by diethanol amine impregnated activated carbon.

PubMed

Das, Dipa; Samal, Debi Prasad; Meikap, Bhim C

2016-07-28

To mitigate the emission of carbon dioxide (CO2), we have developed and designed a four-stage fluidized bed reactor. There is a counter current exchange between solid adsorbent and gas flow. In this present investigation diethanol amine (DEA) impregnated activated carbon made from green coconut shell was used as adsorbent. This type of adsorbent not only adsorbs CO2 due to the presence of pore but also chemically reacts with CO2 and form secondary zwitterions. Sampling and analysis of CO2 was performed using Orsat apparatus. The effect of initial CO2 concentration, gas velocity, solid rate, weir height etc. on removal efficiency of CO2 have been investigated and presented. The percentage removal of CO2 has been found close to 80% under low gas flow rate (0.188 m/s), high solid flow rate (4.12 kg/h) and weir height of 50 mm. From this result it has been found out that multistage fluidized bed reactor may be a suitable equipment for removal of CO2 from flue gas.

High Meiofaunal and Nematodes Diversity around Mesophotic Coral Oases in the Mediterranean Sea

PubMed Central

Bianchelli, Silvia; Pusceddu, Antonio; Canese, Simone; Greco, Silvio; Danovaro, Roberto

2013-01-01

Although the mesophotic zone of the Mediterranean Sea has been poorly investigated, there is an increasing awareness about its ecological importance for its biodiversity, as fish nursery and for the recruitment of shallow water species. Along with coastal rocky cliffs, isolated coralligenous concretions emerging from muddy bottoms are typical structures of the Mediterranean Sea mesophotic zone. Coralligenous concretions at mesophotic depths in the South Tyrrhenian Sea were investigated to assess the role of these coralligenous oases in relation to the biodiversity of surrounding soft sediments. We show here that the complex structures of the coralligenous concretions at ca. 110 m depth influence the trophic conditions, the biodiversity and assemblage composition in the surrounding sediments even at considerable distances. Coral concretions not only represent deep oases of coral biodiversity but they also promote a higher biodiversity of the fauna inhabiting the surrounding soft sediments. Using the biodiversity of nematodes as a proxy of the total benthic biodiversity, a high turnover biodiversity within a 200 m distance from the coralligenous concretions was observed. Such turnover is even more evident when only rare taxa are considered and seems related to specific trophic conditions, which are influenced by the presence of the coralligenous structures. The presence of a high topographic complexity and the trophic enrichment make these habitats highly biodiverse, nowadays endangered by human activities (such as exploitation of commercial species such as Corallium rubrum, or trawling fisheries, which directly causes habitat destruction or indirectly causes modification in the sedimentation and re-suspension rates). We stress that the protection of the coralligenous sea concretions is a priority for future conservation policies at the scale of large marine ecosystems and that a complete census of these mesophotic oases of biodiversity should be a priority for future investigations in the Mediterranean Sea. PMID:23823621

Quest for ultimate reality and meaning: a scientist's view

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilbert, T.L.

The theme of unity and diversity is developed in four parts. The first part is an examination of the relationship between unity and diversity in terms of the concepts of scale and resolution, using an imaginary journey in a shrinking spaceship from the cosmos to quarks in order to present the concepts in concrete terms. The second part is an examination of the roles of different fields of scholarship - aesthetics and the humanities, ethics, religion, and science - in coping with diversity and in gleaning the unity hidden in diversity. The third part is an examination of a philosophicalmore » problem, closely related to unity and diversity, that can be expected to play a central role in later stages of the URAM program: the question of what we mean by the word true. The fourth part is a discussion of the concept of reality from the epistemological viewpoint of the sciences, and how unity and diversity enter into this concept.« less

Organizational Challenges to International Cooperation for Literacy in UNESCO

ERIC Educational Resources Information Center

Limage, Leslie J.

2007-01-01

The absolute priority given by UNESCO to the promotion of universal literacy is understood as a key policy driver shaping the Organization since its inception in 1946. Grounded in human rights, the commitment has taken concrete form in many and diverse ways, but it is as a shaper of ideas that UNESCO's overall contribution is best judged. In…

The Shape of Things to Come: A Photo Essay

ERIC Educational Resources Information Center

Connection: The Journal of the New England Board of Higher Education, 2002

2002-01-01

Think of New England higher education and one probably thinks of ivy-covered brick or perhaps 1950s concrete, but the environment of New England's college campuses is far more diverse, more complex, more daring, and more educational than the stereotype. It is changing fast, thanks to profound forces such as consumerization among students,…

Turning Math Remediation into "Homeroom:" Contextualization as a Motivational Environment for Community College Students in Remedial Math

ERIC Educational Resources Information Center

Wang, Xueli; Sun, Ning; Wickersham, Kelly

2017-01-01

Contextualization refers to "a diverse family of instructional strategies designed to more seamlessly link the learning of foundational skills and academic or occupational content by focusing teaching and learning squarely on concrete applications in a specific context that is of interest to the student" (Mazzeo, 2008, p. 3). In…

Constraints upon the Response of Fish and Crayfish to Environmental Flow Releases in a Regulated Headwater Stream Network

PubMed Central

Chester, Edwin T.; Matthews, Ty G.; Howson, Travis J.; Johnston, Kerrylyn; Mackie, Jonathon K.; Strachan, Scott R.; Robson, Belinda J.

2014-01-01

In dry climate zones, headwater streams are often regulated for water extraction causing intermittency in perennial streams and prolonged drying in intermittent streams. Regulation thereby reduces aquatic habitat downstream of weirs that also form barriers to migration by stream fauna. Environmental flow releases may restore streamflow in rivers, but are rarely applied to headwaters. We sampled fish and crayfish in four regulated headwater streams before and after the release of summer-autumn environmental flows, and in four nearby unregulated streams, to determine whether their abundances increased in response to flow releases. Historical data of fish and crayfish occurrence spanning a 30 year period was compared with contemporary data (electrofishing surveys, Victoria Range, Australia; summer 2008 to summer 2010) to assess the longer–term effects of regulation and drought. Although fish were recorded in regulated streams before 1996, they were not recorded in the present study upstream or downstream of weirs despite recent flow releases. Crayfish (Geocharax sp. nov. 1) remained in the regulated streams throughout the study, but did not become more abundant in response to flow releases. In contrast, native fish (Gadopsis marmoratus, Galaxias oliros, Galaxias maculatus) and crayfish remained present in unregulated streams, despite prolonged drought conditions during 2006–2010, and the assemblages of each of these streams remained essentially unchanged over the 30 year period. Flow release volumes may have been too small or have operated for an insufficient time to allow fish to recolonise regulated streams. Barriers to dispersal may also be preventing recolonisation. Indefinite continuation of annual flow releases, that prevent the unnatural cessation of flow caused by weirs, may eventually facilitate upstream movement of fish and crayfish in regulated channels; but other human–made dispersal barriers downstream need to be identified and ameliorated, to allow native fish to fulfil their life cycles in these headwater streams. PMID:24647407

Abundance, Timing of Migration, and Egg-to-Smolt Survival of Juvenile Chum Salmon, Kwethluk River, Alaska, 2007 and 2008

USGS Publications Warehouse

Burril, Sean E.; Zimmerman, Christian E.; Finn, James E.; ,; Gillikin, Daniel; ,

2010-01-01

To better understand and partition mortality among life stages of chum salmon (Oncorhynchus keta), we used inclined-plane traps to monitor the migration of juveniles in the Kwethluk River, Alaska in 2007 and 2008. The migration of juvenile chum salmon peaked in mid-May and catch rates were greatest when water levels were rising. Movement of chum salmon was diurnal with highest catch rates occurring during the hours of low light (that is, 22:00 to 10:00). Trap efficiency ranged from 0.37 to 4.04 percent (overall efficiency = 1.94 percent). Total abundance of juvenile chum salmon was estimated to be 2.0 million fish in 2007 and 2.9 million fish in 2008. On the basis of the estimate of chum salmon females passing the Kwethluk River weir and age-specific fecundity, we estimated the potential egg deposition (PED) upstream of the weir and trapping site. Egg-to-smolt survival, calculated by dividing the estimate of juvenile chum salmon emigrating past the weir site by the estimate of PED, was 4.6 percent in 2007 and 5.2 percent in 2008. In addition to chum salmon, Chinook salmon O. tshawytscha), coho salmon (O. kisutch), sockeye salmon (O. nerka), and pink salmon (O. gorbuscha), as well as ten other fish species, were captured in the traps. As with chum salmon, catch of these species increased during periods of increasing discharge and peaked during hours of low light. This study successfully determined the characteristics of juvenile salmon migrations and estimated egg-to-smolt survival for chum salmon. This is the first estimate of survival for any juvenile salmon in the Arctic-Yukon-Kuskokwim region of Alaska and demonstrates an approach that can help to partition mortality between freshwater and marine life stages, information critical to understanding the dynamics of salmon in this region.

Modeling the Flushing Response to the Construction of a Low Crested Weir in the Banana River

NASA Astrophysics Data System (ADS)

Saberi, A.; Weaver, R. J.

2014-12-01

The ADCIRC hydrodynamic model coupled with a Lagrangian Particle Tracking Model (LPTM) is applied to study circulation in the Banana River. The purpose of this study is to determine the extent to which constructing a low crested weir adjacent to Port Canaveral can improve flushing in this region. The Banana River a 50 km long sub-basin of the Indian River Lagoon (IRL), located on the central-east coast of Florida in Brevard County between Cape Canaveral and Merritt Island. Although Banana River has an outlet to the ocean through the Port Canaveral locks, the locks remain closed when there is no passing vessel resulting in limited circulation, long flushing time and poor water quality. Recent high mortality events of different species, e.g. dolphins, manatees and pelicans in the lagoon ecosystem, can be linked to the decline in the water quality. ADCIRC is used to simulate the hydrodynamic properties of the study area and determine the 2D depth-averaged velocity field for two separate cases: one with only tidal and another with both tidal and meteorological forces considered. Simulations are run, first to establish the baseline hydrodynamics of the unmodified system, and then to predict the effects of modifying the domain. Passive particles are placed in the Banana River portion of our domain, and the movement of these particles is tracked using LPTM for both cases. Flushing and residence time are then computed. Results indicate an improvement in flushing in both the Banana River and the central Indian River Lagoon, driven by an induced southerly current. In the portion of the Banana River to the south of the port complex, tidal flushing time is significantly reduced for the case of modified domain. In this southern region the flushing time based on 50% renewal time, is decreased from 100 days down to 15 days, after the addition of the weir to the domain.

Performance Prediction of Darrieus-Type Hydroturbine with Inlet Nozzle Operated in Open Water Channels

NASA Astrophysics Data System (ADS)

Nakashima, K.; Watanabe, S.; Matsushita, D.; Tsuda, S.; Furukawa, A.

2016-11-01

Small hydropower is one of the renewable energies and is expected to be effectively used for local supply of electricity. We have developed Darrieus-type hydro-turbine systems, and among them, the Darrieus-turbine with a weir and a nozzle installed upstream of turbine is, so far, in success to obtain more output power by gathering all water into the turbine. However, there can several cases exist, in which installing the weir covering all the flow channel width is unrealistic, and in such cases, the turbine should be put alone in open channels without upstream weir. Since the output power is very small in such a utilization of small hydropower, it is important to derive more power for the cost reduction. In the present study, we parametrically investigate the preferable shape of the inlet nozzle for the Darrieus-type hydroturbine operated in an open flow channel. Experimental investigation is carried out in the open channel in our lab. Tested inlet nozzles are composed of two flat plates with the various nozzle converging angles and nozzle outlet (runner inlet) widths with the nozzle inlet width kept constant. As a result, the turbine with the nozzles having large converging angle and wide outlet width generates higher power. Two-dimensional unsteady numerical simulation is also carried out to qualitatively understand the flow mechanism leading to the better performance of turbine. Since the depth, the width and the flow rate in the real open flow channels are different from place to place and, in some cases from time to time, it is also important to predict the onsite performance of the hydroturbine from the lab experiment at planning stage. One-dimensional stream-tube model is developed for this purpose, in which the Darrieus-type hydroturbine with the inlet nozzle is considered as an actuator-disk modelled based on our experimental and numerical results.

Performance of fish passage structures at upstream barriers to migration

USGS Publications Warehouse

Bunt, C.M.; Castro-Santos, T.; Haro, A.

2012-01-01

Attraction and passage efficiency were reviewed and compared from 19 monitoring studies that produced data for evaluations of pool-and-weir, Denil, vertical-slot and nature-like fishways. Data from 26 species of anadromous and potamodromous fishes from six countries were separated by year and taxonomic family into a matrix with 101 records. Attraction performance was highly variable for the following fishway structures: pool-and-weir (attraction range = 29–100%, mean = 77%, median = 81%), vertical-slot (attraction range = 0–100%, mean = 63%, median = 80%), Denil (attraction range = 21–100%, mean = 61%, median = 57%) and nature-like (attraction range = 0–100%, mean = 48%, median = 50%). Mean passage efficiency was inversely related to mean attraction efficiency by fishway structure type, with the highest passage for nature-like fishways (range = 0–100%, mean = 70%, median = 86%), followed by Denil (range = 0–97%, mean = 51%, median = 38%), vertical-slot (range = 0–100%, mean = 45%, median = 43%) and pool-and-weir (range = 0–100%, mean = 40%, median = 34%). Principal components analysis and logistic regression modelling indicated that variation in fish attraction was driven by biological characteristics of the fish that were studied, whereas variation in fish passage was related to fishway type, slope and elevation change. This meta-analysis revealed that the species of fish monitored and structural design of the fishways have strong implications for both attraction and passage performance, and in most cases, existing data are not sufficient to support design recommendations. Many more fishway evaluations are needed over a range of species, fishway types and configurations to characterize, to optimize and to design new fishways. Furthermore, these studies must be performed in a consistent manner to identify the relative contributions of fish attraction and passage to overall fishway performance at each site.

Microplastics profile along the Rhine River

PubMed Central

Mani, Thomas; Hauk, Armin; Walter, Ulrich; Burkhardt-Holm, Patricia

2015-01-01

Microplastics result from fragmentation of plastic debris or are released to the environment as pre-production pellets or components of consumer and industrial products. In the oceans, they contribute to the ‘great garbage patches’. They are ingested by many organisms, from protozoa to baleen whales, and pose a threat to the aquatic fauna. Although as much as 80% of marine debris originates from land, little attention was given to the role of rivers as debris pathways to the sea. Worldwide, not a single great river has yet been studied for the surface microplastics load over its length. We report the abundance and composition of microplastics at the surface of the Rhine, one of the largest European rivers. Measurements were made at 11 locations over a stretch of 820 km. Microplastics were found in all samples, with 892,777 particles km −2 on average. In the Rhine-Ruhr metropolitan area, a peak concentration of 3.9 million particles km −2 was measured. Microplastics concentrations were diverse along and across the river, reflecting various sources and sinks such as waste water treatment plants, tributaries and weirs. Measures should be implemented to avoid and reduce the pollution with anthropogenic litter in aquatic ecosystems. PMID:26644346

Microplastics profile along the Rhine River

NASA Astrophysics Data System (ADS)

Mani, Thomas; Hauk, Armin; Walter, Ulrich; Burkhardt-Holm, Patricia

2015-12-01

Microplastics result from fragmentation of plastic debris or are released to the environment as pre-production pellets or components of consumer and industrial products. In the oceans, they contribute to the ‘great garbage patches’. They are ingested by many organisms, from protozoa to baleen whales, and pose a threat to the aquatic fauna. Although as much as 80% of marine debris originates from land, little attention was given to the role of rivers as debris pathways to the sea. Worldwide, not a single great river has yet been studied for the surface microplastics load over its length. We report the abundance and composition of microplastics at the surface of the Rhine, one of the largest European rivers. Measurements were made at 11 locations over a stretch of 820 km. Microplastics were found in all samples, with 892,777 particles km -2 on average. In the Rhine-Ruhr metropolitan area, a peak concentration of 3.9 million particles km -2 was measured. Microplastics concentrations were diverse along and across the river, reflecting various sources and sinks such as waste water treatment plants, tributaries and weirs. Measures should be implemented to avoid and reduce the pollution with anthropogenic litter in aquatic ecosystems.

Microplastics profile along the Rhine River.

PubMed

Mani, Thomas; Hauk, Armin; Walter, Ulrich; Burkhardt-Holm, Patricia

2015-12-08

Microplastics result from fragmentation of plastic debris or are released to the environment as pre-production pellets or components of consumer and industrial products. In the oceans, they contribute to the 'great garbage patches'. They are ingested by many organisms, from protozoa to baleen whales, and pose a threat to the aquatic fauna. Although as much as 80% of marine debris originates from land, little attention was given to the role of rivers as debris pathways to the sea. Worldwide, not a single great river has yet been studied for the surface microplastics load over its length. We report the abundance and composition of microplastics at the surface of the Rhine, one of the largest European rivers. Measurements were made at 11 locations over a stretch of 820 km. Microplastics were found in all samples, with 892,777 particles km (-2) on average. In the Rhine-Ruhr metropolitan area, a peak concentration of 3.9 million particles km (-2) was measured. Microplastics concentrations were diverse along and across the river, reflecting various sources and sinks such as waste water treatment plants, tributaries and weirs. Measures should be implemented to avoid and reduce the pollution with anthropogenic litter in aquatic ecosystems.

7. CLOSEUP VIEW OF THE PUMP DISCHARGE CHANNEL, AND THE ...

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

7. CLOSEUP VIEW OF THE PUMP DISCHARGE CHANNEL, AND THE DISCHARGE WEIR OF THE FOR PUMPS NO. 2 AND 3, LOOKING NORTHEAST. THE SERVICE BRIDGE PROVIDED ACCESS TO THE LEVEE OVER TOBY CREEK. - Wyoming Valley Flood Control System, Woodward Pumping Station, East of Toby Creek crossing by Erie-Lackawanna Railroad, Edwardsville, Luzerne County, PA

A summary of the Caspar Creek watershed study

Treesearch

David M. Burns

1965-01-01

The Caspar Creek Watershed Study, is located on the Jackson State Forest. It is a cooperative study by the California Division of Forestry, The Pacific Southwest Forest and Range Experiment Station, the California Department of Water Resources and the California Department of Fish and Game. The precipitation records were started in 1961. The weirs, however, were not...

Carbon isotope fractionation of dissolved inorganic carbon (DIC) due to outgassing of carbon dioxide from a headwater stream

Treesearch

Daniel H. Doctor; Carol Kendall; Stephen D. Sebestyen; James B. Shanley; Nobuhito Ohte; Elizabeth W. Boyer

2008-01-01

The stable isotopic composition of dissolved inorganic carbon (δ13C-DIC) was investigated as a potential tracer of streamflow generation processes at the Sleepers River Research Watershed, Vermont, USA. Downstream sampling showed δ13C-DIC increased between 3-5% from the stream source to the outlet weir...

75 FR 17158 - Chesapeake and Ohio Canal National Historical Park Advisory Commission; Notice of Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-05

... Ohio Canal National Historical Park Advisory Commission (the Commission) will be held at 9 a.m., on... personal identifying information from public review, we cannot guarantee that we will be able to do so. The members of the Commission are as follows: Mrs. Sheila Rabb Weidenfeld, Chairperson. Mr. Charles J. Weir...

76 FR 44359 - Paul Weir Battershell, N.P.; Suspension Of Registration

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-25

... MB1294711 (for his Meridian registered location), and the denial of any pending applications to renew or... ``violations of Federal law in distributing this drug are relevant in assessing whether * * * Respondent would... Federal law) from two companies that were not licensed to distribute drugs in Idaho. GX 2, at 5, 7-10; Tr...

77 FR 52709 - Loup River Public Power District; Notice of Application Accepted for Filing, Soliciting Motions...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-30

... the Loup Canal and containing a floating hydraulic dredge and skimming weir; (6) the Monroe Powerhouse containing three Francis-type, turbine-generating units each with a rated capacity of 2.612 megawatts (MW... Powerhouse containing three Francis-type, turbine-generating units each with a rated capacity of 15.2 MW; and...

Flow-Control Systems Proof of Concept for Snowmelt Runoff at McMurdo Station, Antarctica

DTIC Science & Technology

2017-01-01

flows in the channels. However, the weirs became nonfunctional under high and surge flows. Experimental settling basins were constructed to... Results ................................................................................................................ 22 4.1 Flow and sediment...Runoff from the wa- tershed results almost exclusively from snowmelt, which passes through McMurdo via a system of drainage ditches, gullies, and

Maintenance Dredging & Confined Disposal Facility for the Crooked River Portion of Michigan’s Inland Route and the Operation, Maintenance, & Proposed Public Use Facilities for the Alanson Lock and Weir, Michigan.

DTIC Science & Technology

1980-01-01

Dwarf lake iris, threatened. Calypso bulbosa, Calypso or Fairy - slipper , threatened. Cypripedium aietinum, Ram’s head lady- slipper , rare. Orchis...rotundifolia, Round-leaved orchid , threatened. Agropyron dasystachyum, threatened. Beckmannia syzigachne, Slough grass, threatened. Bromus pumpellianus

77 FR 10504 - Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments, Motions To...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-22

... Competing Applications; Alaska Village Electric Cooperative On February 13, 2012, Alaska Village Electric... the stream bed. The weir would not create any significant impoundment of water and would only be high enough to have an intake that pulls water from the midpoint of the water column. This would allow...

Environmental Fate and Impacts of Sulfometuron on Watersheds in the Southern United States

Treesearch

J.L. Michael

2003-01-01

Dissipation of sulfometuron (SM), methyl 2-[[[[(4,6-diiethyl-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl] benzoate, in streamflow, sediment, plant tissue, litter, and soil following operational forestry applications at the target rate of 0.42 kg a.i. ha-1 was monitored. Streamflow samples were collected at a weir on the perimeter and 30...

Elytroderm disease in young, planted Jeffrey pine, South Lake Tahoe, California

Treesearch

Robert F. Scharpf; Robert V. Bega

1988-01-01

Little is known about Elytrodema disease (Elytroderma deformans [Weir] Darker) in seedlings or very young trees. Of 100, 2-0 Jeffrey pine (Pinus jeffreyi Grev. & Balf.) seedlings planted in the Taylor Creek area of South Lake Tahoe, about half survived from 1973 to 1987. During this period about two thirds of the surviving...

Automatic devices to take water samples and to raise trash screens at weirs

Treesearch

K. G. Reinhart; R. E. Leonard; G. E. Hart

1960-01-01

Experimentation on small watersheds is assuming increasing importance in watershed-management research. Much has been accomplished in developing adequate instrumentation for use in these experiments. Yet many problems still await solution. One difficulty encountered is that small streams are subject to wide variations in flow and that these variations are generally...

Selection of loblolly pine varieties resistant to fusiform rust for commercial deployment

Treesearch

Andy Benowicz; Robert J. Weir

2012-01-01

Benowicz, Andy; Weir, Robert J. 2013. Selection of loblolly pine varieties resistant to fusiform rust for commercial deployment . In: Sniezko, Richard A.; Yanchuk, Alvin D.; Kliejunas, John T.; Palmieri, Katharine M.; Alexander, Janice M.; Frankel, Susan J., tech. coords. Proceedings of the fourth international workshop on the genetics of host-parasite interactions in...

Making the News: Jobs in TV Journalism

ERIC Educational Resources Information Center

Csorny, Lauren

2009-01-01

What do TV news workers do each day? For many of them, contributing to daily news broadcasts has changed greatly over the years. This evolution will likely continue for years to come. And more changes to news production are expected, according to Tom Weir, an associate professor at the University of South Carolina's School of Journalism and Mass…

Authorship Correction: Sampling Key Populations for HIV Surveillance: Results From Eight Cross-Sectional Studies Using Respondent-Driven Sampling and Venue-Based Snowball Sampling.

PubMed

Rao, Amrita; Stahlman, Shauna; Hargreaves, James; Weir, Sharon; Edwards, Jessie; Rice, Brian; Kochelani, Duncan; Mavimbela, Mpumelelo; Baral, Stefan

2018-01-15

[This corrects the article DOI: 10.2196/publichealth.8116.]. ©Amrita Rao, Shauna Stahlman, James Hargreaves, Sharon Weir, Jessie Edwards, Brian Rice, Duncan Kochelani, Mpumelelo Mavimbela, Stefan Baral. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 15.01.2018.

Seasonal use of small tributary and main-stem habitats by juvenile steelhead, coho salmon, and Dolly Varden in a southeastern Alaska drainage basin.

Treesearch

R.G. Bramblett; M.D. Bryant; B.E. Wright; R.G. White

2002-01-01

The movement of juvenile salmonids between small tributaries and main-stem habitats in southeast Alaska watersheds is poorly understood. We observed movements of steelhead Oncorhynchus mykiss, coho salmon O. kisutch, and Dolly Varden Salvelinus malma between mainstem and tributary habitats at weirs located...

76 FR 8728 - Bear Creek Hydro Associates, LLC; Notice of Preliminary Permit Application Accepted for Filing...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-15

... on Bear Creek, near Concrete, Washington. The sole purpose of a preliminary permit, if issued, is to... includes the following existing facilities: (1) A 100-foot-long diversion structure with a 30-foot-long, 6-foot- high ungated overflow spillway section at an elevation of 987 feet msl; (2) a 400-foot-long, 36...

The Theory and Application of Contextualized Teaching and Learning in Relation to Programs of Study and Career Pathways. Transition Highlights. Issue 2

ERIC Educational Resources Information Center

Kalchik, Stephanie; Oertle, Kathleen Marie

2010-01-01

Contextualized Teaching and Learning (CTL), also known as Contextualized Instruction, is defined as a "diverse family of instructional strategies designed to more seamlessly link the learning of foundational skills and academic or occupational content by focusing teaching and learning squarely on concrete applications in a specific context that is…

Culturally diverse health care students' experiences with teaching strategies in Finland: a national survey.

PubMed

Pitkajarvi, Marianne; Eriksson, Elina; Pitkala, Kaisu

2013-06-01

All over the world, current health care students come from a variety of cultural, linguistic and educational backgrounds. Their expectations and learning needs vary, yet little is known about how our current education system meets their needs. The purpose of this study was to explore culturally diverse health care students' experiences of teaching strategies in polytechnic faculties of health care in Finland. Specifically, we aimed to compare how international students and Finnish students experience the same curriculum. A cross sectional survey. Ten polytechnic faculties of health care in Finland offering English-Language-Taught Degree Programmess (ELTDPs). 283 students studying nursing, public health nursing, or physiotherapy in English. Of these, 166 were international students and 112 were Finnish students. The data were collected using a questionnaire designed specifically for this study. The survey included items grouped into seven dimensions: 1. concreteness of theoretical instruction, 2. encouragement of student activity, 3. use of skills labs, 4. variation among teaching strategies, 5. assessment, 6. interaction in the English-Language-Taught Degree Programmes, and 7. approach to diversity in the English-Language-Taught Degree Programmes. The most positive experiences for all students were with the approach to cultural diversity and the concreteness of theoretical instruction, whereas the most negative experiences were with assessment. International students' experiences were more positive than Finnish students' in the following dimensions: encouragement of student activity (p=0.005), variation among teaching strategies (p<0.001), and assessment (p<0.001). Compared to the Finnish students, more than double the number of international students were dissatisfied with their lives (p<0.001). The implications for education include the strengthening teachers' leadership role in small group activities, providing individual and detailed feedback, and ensuring appropriate support mechanisms for all students. Copyright © 2012 Elsevier Ltd. All rights reserved.

Microbial Diversity in Sediment Ecosystems (Evaporites Domes, Microbial Mats, and Crusts) of Hypersaline Laguna Tebenquiche, Salar de Atacama, Chile.

PubMed

Fernandez, Ana B; Rasuk, Maria C; Visscher, Pieter T; Contreras, Manuel; Novoa, Fernando; Poire, Daniel G; Patterson, Molly M; Ventosa, Antonio; Farias, Maria E

2016-01-01

We combined nucleic acid-based molecular methods, biogeochemical measurements, and physicochemical characteristics to investigate microbial sedimentary ecosystems of Laguna Tebenquiche, Atacama Desert, Chile. Molecular diversity, and biogeochemistry of hypersaline microbial mats, rhizome-associated concretions, and an endoevaporite were compared with: The V4 hypervariable region of the 16S rRNA gene was amplified by pyrosequencing to analyze the total microbial diversity (i.e., bacteria and archaea) in bulk samples, and in addition, in detail on a millimeter scale in one microbial mat and in one evaporite. Archaea were more abundant than bacteria. Euryarchaeota was one of the most abundant phyla in all samples, and particularly dominant (97% of total diversity) in the most lithified ecosystem, the evaporite. Most of the euryarchaeal OTUs could be assigned to the class Halobacteria or anaerobic and methanogenic archaea. Planctomycetes potentially also play a key role in mats and rhizome-associated concretions, notably the aerobic organoheterotroph members of the class Phycisphaerae. In addition to cyanobacteria, members of Chromatiales and possibly the candidate family Chlorotrichaceae contributed to photosynthetic carbon fixation. Other abundant uncultured taxa such as the candidate division MSBL1, the uncultured MBGB, and the phylum Acetothermia potentially play an important metabolic role in these ecosystems. Lithifying microbial mats contained calcium carbonate precipitates, whereas endoevoporites consisted of gypsum, and halite. Biogeochemical measurements revealed that based on depth profiles of O2 and sulfide, metabolic activities were much higher in the non-lithifying mat (peaking in the least lithified systems) than in lithifying mats with the lowest activity in endoevaporites. This trend in decreasing microbial activity reflects the increase in salinity, which may play an important role in the biodiversity.

Microbial Diversity in Sediment Ecosystems (Evaporites Domes, Microbial Mats, and Crusts) of Hypersaline Laguna Tebenquiche, Salar de Atacama, Chile

PubMed Central

Fernandez, Ana B.; Rasuk, Maria C.; Visscher, Pieter T.; Contreras, Manuel; Novoa, Fernando; Poire, Daniel G.; Patterson, Molly M.; Ventosa, Antonio; Farias, Maria E.

2016-01-01

We combined nucleic acid-based molecular methods, biogeochemical measurements, and physicochemical characteristics to investigate microbial sedimentary ecosystems of Laguna Tebenquiche, Atacama Desert, Chile. Molecular diversity, and biogeochemistry of hypersaline microbial mats, rhizome-associated concretions, and an endoevaporite were compared with: The V4 hypervariable region of the 16S rRNA gene was amplified by pyrosequencing to analyze the total microbial diversity (i.e., bacteria and archaea) in bulk samples, and in addition, in detail on a millimeter scale in one microbial mat and in one evaporite. Archaea were more abundant than bacteria. Euryarchaeota was one of the most abundant phyla in all samples, and particularly dominant (97% of total diversity) in the most lithified ecosystem, the evaporite. Most of the euryarchaeal OTUs could be assigned to the class Halobacteria or anaerobic and methanogenic archaea. Planctomycetes potentially also play a key role in mats and rhizome-associated concretions, notably the aerobic organoheterotroph members of the class Phycisphaerae. In addition to cyanobacteria, members of Chromatiales and possibly the candidate family Chlorotrichaceae contributed to photosynthetic carbon fixation. Other abundant uncultured taxa such as the candidate division MSBL1, the uncultured MBGB, and the phylum Acetothermia potentially play an important metabolic role in these ecosystems. Lithifying microbial mats contained calcium carbonate precipitates, whereas endoevoporites consisted of gypsum, and halite. Biogeochemical measurements revealed that based on depth profiles of O2 and sulfide, metabolic activities were much higher in the non-lithifying mat (peaking in the least lithified systems) than in lithifying mats with the lowest activity in endoevaporites. This trend in decreasing microbial activity reflects the increase in salinity, which may play an important role in the biodiversity. PMID:27597845

Development of concepts for low-cost energy storage assemblies for annual cycle energy system applications

NASA Astrophysics Data System (ADS)

Alexander, G. H.; Cooper, D. L.; Cummings, C. A.; Reiber, E. E.

1981-10-01

Low cost energy storage assemblies were developed. In the search for low overall cost assemblies, many diverse concepts and materials were postulated and briefly evaluated. Cost rankings, descriptions, and discussions of the concepts were presented from which ORNL selected the following three concepts for the Phase 2 development: (1) a site constructed tank with reinforced concrete walls formed with specialized modular blocks which eliminates most concrete form work and provides integral R-20 insulation designated ORNLFF; (2) a site constructed tank with earth supported walls that are formed from elements common to residential, in-ground swimming pools, designated SWPL; (3) and a site assembled tank used in underground utility vaults, designated UTLBX. Detailed designs of free standing versions of the three concepts are presented.

6. CLOSEUP VIEW OF THE PUMP DISCHARGE CHANNEL, THE FLAP ...

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

6. CLOSEUP VIEW OF THE PUMP DISCHARGE CHANNEL, THE FLAP VALVES OF THE PUMPING UNITS 8, 6, AND 7 (L TO R) AND PART OF THE DISCHARGE WEIR OF THE INDIVIDUAL DISCHARGE CHAMBER OF PUMP NO. 5, LOOKING NORTHEAST. - Wyoming Valley Flood Control System, Woodward Pumping Station, East of Toby Creek crossing by Erie-Lackawanna Railroad, Edwardsville, Luzerne County, PA

75 FR 41520 - Chesapeake and Ohio Canal National Historical Park Advisory Commission; Notice of Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-16

... Ohio Canal National Historical Park Advisory Commission will be held at 9 a.m., on Friday, August 13... information from public review, we cannot guarantee that we will be able to do so. SUPPLEMENTARY INFORMATION... Rabb Weidenfeld, Chairperson Mr. Charles J. Weir Mr. Barry A. Passett Mr. James G. McCleaf II Mr. John...

Insights from long-term research on the Fernow Experimental Forest

Treesearch

Mary Beth Adams

2016-01-01

In 1951, five weirs were constructed in the mixed hardwood forests of the Fernow Experimental Forest and watershed research began. Specializing in long-term watershed scale manipulations, researchers at the Fernow have evaluated effects of various silvicultural practices on water yield, seasonal flow patterns, water quality and on ecosystem processes and ecosystem...

75 FR 30052 - Nomans Land Island National Wildlife Refuge, Town of Chilmark, MA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-28

... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service [FWS-R5-R-2009-N185; BAC-4311-K9-S3] Nomans Land Island National Wildlife Refuge, Town of Chilmark, MA AGENCY: Fish and Wildlife Service, Interior... Weir Hill Road, Sudbury, MA 01776. In-Person Drop-off, Viewing, or Pickup: Call 978-443-4661 to make an...

Validation of an ESL Writing Test in a Malaysian Secondary School Context

ERIC Educational Resources Information Center

Zainal, Azlin

2012-01-01

The present study was conducted with a twofold purpose. First, I aim to apply the socio-cognitive framework by Shaw and Weir (2007) in order to validate a summative writing test used in a Malaysian ESL secondary school context. Secondly, by applying the framework I also aim to illustrate practical ways in which teachers can gather validity…

A Hybrid Location Method for Missile Security Team Positioning

DTIC Science & Technology

2007-01-01

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. A Hybrid Location Method for Missile Security...Bell and Weir A Hybrid Location Method for Missile Security Team Positioning Chief Master Sergeant Michael C. Dawson Air Force Logistics Management...problem oj locating security teams over a geographic area to maintain security Jor US Air Force Intercontinental Ballistic Missile Systems. A

Larch dwarf mistletoe not found on alpine larch

Treesearch

Robert L. Mathiasen; Brian W. Geils; Clinton E. Carlson; Frank G. Hawksworth

1995-01-01

Reports of larch dwarf mistletoe parasitizing alpine larch are based on two collections of this host/parasite combination made by J.R. Weir in Montana during the early 1900s. Examination of host material from these collections indicates that the host is western larch, not alpine larch as previously reported. Attempts to locate larch dwarf mistletoe on alpine larch were...

Control-Structure Ratings on the Fox River at McHenry and Algonquin, Illinois

USGS Publications Warehouse

Straub, Timothy D.; Johnson, Gary P.; Hortness, Jon E.; Parker, Joseph R.

2009-01-01

The Illinois Department of Natural Resources-Office of Water Resources operates control structures on a reach of the Fox River in northeastern Illinois between McHenry and Algonquin. The structures maintain water levels in the river for flood-control and recreational purposes. This report documents flow ratings for hinged-crest gates, a broad-crested weir, sluice gates, and an ogee spillway on the control structures at McHenry and Algonquin. The ratings were determined by measuring headwater and tailwater stage along with streamflow at a wide range of flows at different gate openings. Standard control-structure rating techniques were used to rate each control structure. The control structures at McHenry consist of a 221-feet(ft)-long broad-crested weir, a 4-ft-wide fish ladder, a 50-ft-wide hinged-crest gate, five 13.75-ft-wide sluice gates, and a navigational lock. Sixty measurements were used to rate the McHenry structures. The control structures at Algonquin consist of a 242-ft-long ogee spillway and a 50-ft-wide hinged-crest gate. Forty-one measurements were used to rate the Algonquin control structures.

Improved chip design for integrated solid-phase microextraction in on-line proteomic sample preparation.

PubMed

Bergkvist, Jonas; Ekström, Simon; Wallman, Lars; Löfgren, Mikael; Marko-Varga, György; Nilsson, Johan; Laurell, Thomas

2002-04-01

A recently introduced silicon microextraction chip (SMEC), used for on-line proteomic sample preparation, has proved to facilitate the process of protein identification by sample clean up and enrichment of peptides. It is demonstrated that a novel grid-SMEC design improves the operating characteristics for solid-phase microextraction, by reducing dispersion effects and thereby improving the sample preparation conditions. The structures investigated in this paper are treated both numerically and experimentally. The numerical approach is based on finite element analysis of the microfluidic flow in the microchip. The analysis is accomplished by use of the computational fluid dynamics-module FLOTRAN in the ANSYS software package. The modeling and analysis of the previously reported weir-SMEC design indicates some severe drawbacks, that can be reduced by changing the microextraction chip geometry to the grid-SMEC design. The overall analytical performance was thereby improved and also verified by experimental work. Matrix-assisted laser desorption/ionization mass spectra of model peptides extracted from both the weir-SMEC and the new grid-SMEC support the numerical analysis results. Further use of numerical modeling and analysis of the SMEC structures is also discussed and suggested in this work.

A spatial capture-recapture model to estimate fish survival and location from linear continuous monitoring arrays

USGS Publications Warehouse

Raabe, Joshua K.; Gardner, Beth; Hightower, Joseph E.

2013-01-01

We developed a spatial capture–recapture model to evaluate survival and activity centres (i.e., mean locations) of tagged individuals detected along a linear array. Our spatially explicit version of the Cormack–Jolly–Seber model, analyzed using a Bayesian framework, correlates movement between periods and can incorporate environmental or other covariates. We demonstrate the model using 2010 data for anadromous American shad (Alosa sapidissima) tagged with passive integrated transponders (PIT) at a weir near the mouth of a North Carolina river and passively monitored with an upstream array of PIT antennas. The river channel constrained migrations, resulting in linear, one-dimensional encounter histories that included both weir captures and antenna detections. Individual activity centres in a given time period were a function of the individual’s previous estimated location and the river conditions (i.e., gage height). Model results indicate high within-river spawning mortality (mean weekly survival = 0.80) and more extensive movements during elevated river conditions. This model is applicable for any linear array (e.g., rivers, shorelines, and corridors), opening new opportunities to study demographic parameters, movement or migration, and habitat use.

3D numerical simulation of flow field with incompletely flaring gate pier in large unit discharge and deep tail water project

NASA Astrophysics Data System (ADS)

Zhao, Zhou; Junxing, Wang

2018-06-01

Limited by large unit discharge above the overflow weir and deep tail water inside the stilling basin, the incoming flow inside stilling basin is seriously short of enough energy dissipation and outgoing flow still carries much energy with large velocity, bound to result in secondary hydraulic jump outside stilling basin and scour downstream river bed. Based on the RNG k-ɛ turbulence model and the VOF method, this paper comparatively studies flow field between the conventional flat gate pier program and the incompletely flaring gate pier program to reveal energy dissipation mechanism of incomplete flaring gate pier. Results show that incompletely flaring gate pier can greatly promote the longitudinally stretched water jet to laterally diffuse and collide in the upstream region of stilling basin due to velocity gradients between adjacent inflow from each chamber through shrinking partial overflow flow chamber weir chamber, which would lead to large scale vertical axis vortex from the bottom to the surface and enhance mutual shear turbulence dissipation. This would significantly increase energy dissipation inside stilling basin to reduce outgoing velocity and totally solve the common hydraulic problems in large unit discharge and deep tail water projects.

77 FR 40606 - United Water; Notice of Declaration of Intention and Petition for Relief, and Soliciting Comments...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-10

....2001(a)(l)(iii) and the instructions on the Commission's Web site under the ``eFiling'' link. If unable... the Commission's Web site located at http://www.ferc.gov/filing-comments.asp . Please include the..., which will be dropped into a 8-foot-long, 6-foot-wide, and 6-foot-deep concrete diversion chamber that...

Nondestructive analysis of alkali-silica reaction damage in concrete slabs using shear waves

NASA Astrophysics Data System (ADS)

Khazanovich, Lev; Freeseman, Katelyn; Salles, Lucio; Clayton, Dwight

2018-04-01

Alkali-silica reaction (ASR) is the chemical reaction that occurs in concrete. It is caused by the interaction of alkalis in Portland cement and silica in aggregates and results in microcracks within the material. This type of damage has been the focus of nondestructive evaluation efforts in recent history, but no work was done on in-situ structures or large-scale samples. To address these limitations, an ultrasonic linear array device, MIRA, was utilized for this research. An experimental investigation was performed on four slabs with various levels of alkali-silica reaction at the Electric Power Research Institute (EPRI) [1]. One-period impulses with a target of 50kHz center frequency were selected in this study. We propose the use of the Hilbert Transform Indicator (HTI) for quantification of ASR damage [2]. A higher HTI value would be indicative of damaged concrete, while a low value represents sound concrete. In general, values below 90 are regarded as an indicator of sound concrete while values above 100 indicate the presence of damage [3]. The ability of the HTI values to distinguish between areas of damaged concrete was evident via the production of color intensity maps. The maps show that the control specimen, was in good condition, while other slabs exhibited higher levels of damage as indicated by the HTI values. It should be noted that extreme damage conditions were not present in any of the slabs. Evaluation of migration-based reconstructions can give a qualitative characterization of large scale or excessive subsurface damage. However, for detection of stochastic damage mechanisms such as freeze-thaw damage, evaluation of the individual time-history data can provide additional information. A comparison of the spatially diverse measurements on several concrete slabs with varying freeze-thaw damage levels is given in this study. Signal characterization scans of different levels of freeze-thaw damage at various transducer spacing is investigated. The results show promise for a SH-wave classification system applicable for nondestructive characterization of freeze-thaw damage conditions.

Factors Affecting Route Selection and Survival of Steelhead Kelts at Snake River Dams in 2012 and 2013

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harnish, Ryan A.; Colotelo, Alison HA; Li, Xinya

2014-12-01

In 2012 and 2013, Pacific Northwest National Laboratory conducted a study that summarized the passage proportions and route-specific survival rates of steelhead kelts that passed through Federal Columbia River Power System (FCRPS) dams. To accomplish this, a total of 811 steelhead kelts were tagged with Juvenile Salmon Acoustic Telemetry System (JSATS) transmitters. Acoustic receivers, both autonomous and cabled, were deployed throughout the FCRPS to monitor the downstream movements of tagged-kelts. Kelts were also tagged with Passive Integrated Transponder tags to monitor passage through juvenile bypass systems and detect returning fish. The current study evaluated data collected in 2012 and 2013more » to identify individual, behavioral, environmental and dam operation variables that were related to passage and survival of steelhead kelts that passed through FCRPS dams. Bayesian model averaging of multivariable logistic regression models was used to identify the environmental, temporal, operational, individual, and behavioral variables that had the highest probability of influencing the route of passage and the route-specific survival probabilities for kelts that passed Lower Granite (LGR), Little Goose (LGS), and Lower Monumental (LMN) dams in 2012 and 2013. The posterior probabilities of the best models for predicting route of passage ranged from 0.106 for traditional spill at LMN to 0.720 for turbine passage at LGS. Generally, the behavior (depth and near-dam searching activity) of kelts in the forebay appeared to have the greatest influence on their route of passage. Shallower-migrating kelts had a higher probability of passing via the weir and deeper-migrating kelts had a higher probability of passing via the JBS and turbines than other routes. Kelts that displayed a higher level of near-dam searching activity had a higher probability of passing via the spillway weir and those that did less near-dam searching had a higher probability of passing via the JBS and turbines. The side of the river in which kelts approached the dam and dam operations also affected route of passage. Dam operations and the size and condition of kelts were found to have the greatest effect on route-specific survival probabilities for fish that passed via the spillway at LGS. That is, longer kelts and those in fair condition had a lower probability of survival for fish that passed via the spillway weir. The survival of spillway weir- and deep-spill passed kelts was positively correlated with the percent of the total discharge that passed through turbine unit 4. Too few kelts passed through the traditional spill, JBS, and turbine units to evaluate survival through these routes. The information gathered in this study describes Snake River steelhead kelt passage behavior, rates, and distributions through the FCRPS as well as provide information to biologists and engineers about the dam operations and abiotic conditions that are related to passage and survival of steelhead kelts.« less

75 FR 65376 - Chesapeake and Ohio Canal National Historical Park Advisory Commission; Notice of Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-22

... National Historical Park Advisory Commission will be held at 9:30 a.m., on Friday, November 5, 2010, at... withhold your personal identifying information from public review, we cannot guarantee that we will be able.... Charles J. Weir Mr. Barry A. Passett Mr. James G. McCleaf II Mr. John A. Ziegler Mrs. Mary E. Woodward Mrs...

Clandestine Message Passing in Virtual Environments

DTIC Science & Technology

2008-09-01

accessed April 4, 2008). Weir, Laila. “Boring Game? Outsorce It.” (August 24, 2004). http://www.wired.com/ entertainment / music /news/2004/08/ 64638...Multiplayer Online MOVES - Modeling Virtual Environments and Simulation MTV – Music Television NPS - Naval Postgraduate School PAN – Personal Area...Network PSP - PlayStation Portable RPG – Role-playing Game SL - Second Life SVN - Subversion VE – Virtual Environments vMTV – Virtual Music

Little Goose Lock and Dam Removable Spillway Weir

DTIC Science & Technology

2007-08-01

Washington , Idaho Little Goose o i Lower w t i e s LIeG Harbor Granite BonnevilleW L••oh Dma•= SDam John Day S’°~Lwer1 Monumental __ •_]McNary Dam le Dam...passage route for 115 kcfs. 18 NG-1 1 Assemble at Little Goose or Lewiston rather than Portland 19 NG-12 Lower the pool elevation during construction to

Response Manual for Combating Spills of Floating Hazardous CHRIS chemicals

DTIC Science & Technology

1989-01-01

CHRIS Chemicals CHRIS Chemical Name Code Floatability PARAFORMALDEHYDE PFA No PARALDEHYDE PDH No PARATHION PTO No PENTABORANE PTB No PENTACHLOROETHANE...5.2.1.3 Weir Skimmers ................................ 76 5.2.2 Chemical Removal Techniques ........................... 77 5.2.2.1 Sorption ...an- ditions such as high winds and rain 5.2.2.1 Sorption Sorption is commonly applied in water treatment processes. Being a surface process

Remote Sensing Survey and Evaluation of the American Pass and Blue Point Chute Weirs, Atchafalaya Channel Training Project, Louisiana

DTIC Science & Technology

1989-06-01

Calhoun the Estrella and the Arizona. The Calhoun fired on the Queen of the West, hitting a steam line and setting her on fire. Soon after she exploded...of most of Taylor’s forces from the region, four Union gunboats, the Calhoun the Estrella the Arizona and the Clifton, steamed up the Atchafalaya

Artificial recharge to the Floridan aquifer system, Orlando Area, Central Florida

USGS Publications Warehouse

German, E.R.; Bradner, L.A.

1989-01-01

Approximately 400 drainage wells exist in Orange County, central Florida. The rate of recharge through drainage wells is limited by the rate of surface flow to the wells; the hydraulic properties of weirs, overflow pipes, and well casings; or the water level above the top of the casing. The rate commonly is not limited by the hydraulic properties of the very transmissive aquifer system.

EMERGING TECHNOLOGY BULLETIN: ELECTRON BEAM TREATMENT FOR THE REMOVAL OF BENZENE AND TOULENE FROM AQUEOUS STREAMS AND SLUDGES

EPA Science Inventory

The electron accelerator utilized in this treatment process has a potential of 1.5 MeV, rated from 0 to 50 mA, providing radiation doses of 0-850 krad (0-8.5 kGy). The horizontal electron beam is scanned at 200 Hz and impacts the waste stream as it flows over a weir approximately...

National Program for Inspection of Non-Federal Dams. Berry Brook Dam, (NH 00313), State Number 83.06, Piscataqua River Basin, Farmington, New Hampshire. Phase I Inspection Report.

DTIC Science & Technology

1979-12-01

at embedded steel items 7 Spalling Minor spalling of surface ’+ deep exposi gcoarse aggregate of weir and dcwnstream f ce. Any Visible Reinforcing...1937, the above dam was inspected by me on _L LEO acomprie _ NOTES ON PHYSICAL CONDITI IT Ab ut mcnt s

Summer Movements within the Fish Community of a Small Montane Stream

Treesearch

David A. Schmetterling; Susan B. Adams

2004-01-01

We studied movements by fishes in Chamberlain Creek, Montana, from 24 July to 16 August 2001. We operated six weirs with two-way traps and one additional upstream trap, separated by 14-1,596 m, to quantify the timing, direction, and distance of movements and to estimate fish populations in the study reaches. We trapped and marked 567 fish of seven species, including...

Guidance for the Development of Air Force Storm Water Sampling Programs

DTIC Science & Technology

1993-09-01

38 Storm Water Quality Monitoring ................. 39 Determining Flow Rate ....................... 42 Weirs and Flumes... water quality monitoring it is not possible to analyze the entire nmoff from a drainage basin. The objective of water quality sampling is to collect a...development of storm water pollution prevention plans. Best management practices can also be developed to control the pollution sources identified. In storm

Substratum type affects recruitment and development of marine assemblages over artificial substrata: A case study in the Alboran Sea

NASA Astrophysics Data System (ADS)

Sempere-Valverde, Juan; Ostalé-Valriberas, Enrique; Farfán, Gonzalo M.; Espinosa, Free

2018-05-01

There are more than 27,000 harbours along coasts worldwide and construction is expected to increase. The development and application of new ecological engineering ideas, for both old and new structures, is now imperative in order to reduce perturbation on marine coastal biota and to avoid the spread of non-native species. In this study, the early benthic assessment of subtidal and intertidal communities is tracked on five artificial substrata differing in origin, roughness, and chemical composition: Oyster Sandstone, Limestone, Gabbro, Slate and Concrete. Within substrata, Sandstone was the roughest on a 1-2 mm scale. Also, Sandstone and Limestone had predominantly calcareous composition while silicon was abundant in Concrete, Gabbro and Slate. In the intertidal zone, results showed that primary productivity and diatom abundance markedly increased with substratum roughness. In the subtidal zone, species richness and diversity over experimental substrata were lower than in adjacent rocky reefs. Nonetheless, during the first year of colonization communities varied within the experimental substrata. Coverage was higher on Sandstone than Concrete and Gabbro, and species richness was higher on Sandstone than Limestone. The differences are related to intrinsic substratum-type characteristics and showed Limestone, Gabbro and Concrete hold relatively poor ecological benefits in the first phases of ecological succession. The results may help to promote future research in this field and to test different substrata combinations and heterogeneities, for more environmentally sustainable surfaces in design of coastal structures.

Moving beyond normative philosophies and policy concerns: a sociological account of place-based solidarities in diversity.

PubMed

Oosterlynck, Stijn

2018-01-01

In this commentary, I think with and beyond the normative philosophies and policy-oriented frameworks on how to deal with diversity in contemporary societies formulated by Zapata-Barrero and Modood. I propose to integrate elements of both perspectives in a empirically grounded sociological account of how place-based solidarities in diversity are nurtured in everyday life. Although there is much to be recommended about the arguments of Modood and Zapata-Barrero, I argue that what is needed is an analytical framework that does not a priori privilege specific sources of solidarity on normative-philosophical or policy grounds. We need to focus instead on how people mobilise different sources of solidarity in their attempts to take shared responsibility for the concrete places where they live, work, learn and play together in superdiversity. This micro-level focus does not mean that one ignores macro-level processes. Also, more attention should be paid to the transformative nature of solidarities in diversity.

Mediating objects: scientific and public functions of models in nineteenth-century biology.

PubMed

Ludwig, David

2013-01-01

The aim of this article is to examine the scientific and public functions of two- and three-dimensional models in the context of three episodes from nineteenth-century biology. I argue that these models incorporate both data and theory by presenting theoretical assumptions in the light of concrete data or organizing data through theoretical assumptions. Despite their diverse roles in scientific practice, they all can be characterized as mediators between data and theory. Furthermore, I argue that these different mediating functions often reflect their different audiences that included specialized scientists, students, and the general public. In this sense, models in nineteenth-century biology can be understood as mediators between theory, data, and their diverse audiences.

Fish population genetic structure shaped by hydroelectric power plants in the upper Rhine catchment.

PubMed

Gouskov, Alexandre; Reyes, Marta; Wirthner-Bitterlin, Lisa; Vorburger, Christoph

2016-02-01

The Rhine catchment in Switzerland has been transformed by a chain of hydroelectric power stations. We addressed the impact of fragmentation on the genetic structure of fish populations by focusing on the European chub (Squalius cephalus). This fish species is not stocked and copes well with altered habitats, enabling an assessment of the effects of fragmentation per se. Using microsatellites, we genotyped 2133 chub from 47 sites within the catchment fragmented by 37 hydroelectric power stations, two weirs and the Rhine Falls. The shallow genetic population structure reflected drainage topology and was affected significantly by barriers to migration. The effect of power stations equipped with fishpasses on genetic differentiation was detectable, albeit weaker than that of man-made barriers without fishpasses. The Rhine Falls as the only long-standing natural obstacle (formed 14 000 to 17 000 years ago) also had a strong effect. Man-made barriers also exacerbated the upstream decrease in allelic diversity in the catchment, particularly when lacking fishpasses. Thus, existing fishpasses do have the desired effect of mitigating fragmentation, but barriers still reduce population connectivity in a fish that traverses fishpasses better than many other species. Less mobile species are likely to be affected more severely.

Methodology for predicting maximum velocity and shear stress in a sinuous channel with bendway weirs using 1-D HEC-RAS modeling results

Treesearch

Paul Sclafani; Christopher I. Thornton; Amanda L. Cox; Steven R. Abt

2012-01-01

As with every natural process, river morphology incorporates a complex and nuanced set of processes that combine to produce an infinite set of possible outcomes. Natural laws that govern natural systems cause rivers to react to changes in the environment in order to maintain equilibrium. Changes in hydraulics, sediment transport, and habitat help keep natural systems...

Modeling water, carbon, and nitrogen dynamics for two drained pine plantations under intensive management practices

Treesearch

Shiying Tian; Mohamed A. Youssef; R. Wayne Skaggs; Devendra Amatya; George M. Chescheir

2012-01-01

This paper reports results of a study to test the reliability of the DRAINMOD-FOREST model for predicting water, soil carbon (C) and nitrogen (N) dynamics in intensively managed forests. The study site, two adjacent loblolly pine (Pinus taeda L.) plantations (referred as D2 and D3), are located in the coastal plain of North Carolina, USA. Controlled drainage (with weir...

Defensive Minefield Planning

DTIC Science & Technology

1989-06-01

Weir, I would like to express my gratitude for his editorial assistance. Finally, I am especially grateful to my friend Lt Cdr. Newton Rodriguez Lima...as their cost effectiveness is realized and as economic priorities limit the growth of military budgets. This is especially true in poorer countries...of ships was not the complete answer, especially in shallow waters. A practical way of sweeping and destroying mines also had to be found. This was

Photographic copy of original drawing, by Corps of Engineers, U.S. ...

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

Photographic copy of original drawing, by Corps of Engineers, U.S. Army, June 1939 (original in possession of Corps of Engineers, U.S. Army, Pittsburgh District, Engineering Division files) Unit 3, control weir at STA. 7+00-Little Conemaugh - Johnstown Local Flood Protection Project, Beginning on Conemaugh River approx 3.8 miles downstream from confluence of Little Conemaugh & Stony Creek Rivers at Johnstown, Johnstown, Cambria County, PA

Photographic copy of historic photograph, by Corps of Engineers, U.S. ...

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

Photographic copy of historic photograph, by Corps of Engineers, U.S. Army, June 10, 1941 (original in possession of Corps of Engineers, U.S. Army, Pittsburgh District, Engineering Division files) Unit 4, view of weir at point, looking southeast - Johnstown Local Flood Protection Project, Beginning on Conemaugh River approx 3.8 miles downstream from confluence of Little Conemaugh & Stony Creek Rivers at Johnstown, Johnstown, Cambria County, PA

Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (78th, Washington, DC, August 9-12, 1995). Communication Theory and Methodology Division.

ERIC Educational Resources Information Center

Association for Education in Journalism and Mass Communication.

The Communication Theory and Methodology section of the proceedings contains the following 18 papers: "The Continuing Question of Motivation in the Knowledge Gap Hypothesis" (Tom Weir); "Memory Decay and the Agenda-Setting Effect: An Examination of Three News Media" (Wayne Wanta and Melissa J. Roy); "Open, Closed, or Both:…

Numerical modelling to assess maintenance strategy management options for a small tidal inlet

NASA Astrophysics Data System (ADS)

Shaeri, Saeed; Tomlinson, Rodger; Etemad-Shahidi, Amir; Strauss, Darrell

2017-03-01

Small tidal inlets are found to be more sensitive to anthropogenic alteration than their larger counterparts. Such alterations, although typically supported by technical design reports, sometimes require amendments or modification. One of the most suitable tools to conduct the necessary studies in this regard is numerical modelling, since the behaviour of the inlet system in response to proposed remedial actions, can easily be identified. In this paper, various alternative proposals are investigated to determine the most practical and viable option to mitigate the need for ongoing maintenance at a typical small, jettied tidal inlet. The main tool to investigate the alternatives is the hydro-sedimentological modelling of the inlet system, which was performed using the Delft3D software package. The proposed alternative entrance modifications were based upon structural alterations of the inlet system (such as a jetty extension or submerged weir) and non-structural scenarios (such as a change of the time of the dredging campaign or the deposition location of the dredged material). It was concluded that whilst a detailed study is inevitable in order to achieve a comprehensive design plan, based upon the results of this study the construction of a submerged weir at the entrance channel can satisfy the needs of most of the stakeholders, with justifiable costs over a longer period.

Improving diversity, inclusion, and representation in radiology and radiation oncology part 2: challenges and recommendations.

PubMed

Lightfoote, Johnson B; Fielding, Julia R; Deville, Curtiland; Gunderman, Richard B; Morgan, Gail N; Pandharipande, Pari V; Duerinckx, Andre J; Wynn, Raymond B; Macura, Katarzyna J

2014-08-01

The ACR Commission for Women and General Diversity is committed to identifying barriers to a diverse physician workforce in radiology and radiation oncology (RRO), and to offering policy recommendations to overcome these barriers. Part 2 of a 2-part position article from the commission addresses issues regarding diversity and inclusion in the context of career choices and professional advancement. Barriers to improving diversity and representation in RRO are reviewed. Discussion focuses on the development and implementation of concrete strategies designed to eliminate the current subspecialty disparity and highlights the need for the ACR to introduce programs and incentives with targeted and achievable goals with measurable outcomes. Recommendations are made aimed at fostering an environment of inclusion and diversity, so as to secure a successful future for all members of the RRO workforce. The future of radiology will be enhanced by increasing diversity and representation in the professional workforce, which will allow us to better address the varied needs of increasingly diverse patient populations, and to mitigate disparities in healthcare access, delivery, and outcomes. By leveraging diverse backgrounds, experiences, and skills of those in RRO, we will create new, effective ways to not only educate our trainees, medical colleagues, and patients but also improve delivery of health care and our service to society. Copyright © 2014 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Patterns of methane-related carbonate formation in the black sea

NASA Astrophysics Data System (ADS)

Reitner, J.; Peckmann, J.; Reimer, A.; Thiel, V.

2003-04-01

Methane seeps on the northwestern Black Sea shelf were investigated during the GHOSTDABS expedition in 2001. Seep areas close to the Dniepr Canyon are sites of intense carbonate formation. In anoxic waters, at depths between 200 and 400 m, we found three different modes of seepage-induced carbonate precipitation. The most spectacular type comprises up to 4 m high Ca-carbonate towers flushed by methane gas (type 1). These buildups are constructed of cm to dm-scale calcified hollow spheres which are made and later surrounded by microbial mats. At the base of these microbial mats the spheres are stabilized by a continuous rim of carbonate cement. At a later stage, the fragile spheres are entirely cemented by fibrous aragonite and Mg calcite. The towers harbour a highly diverse microbial community, which are, at least in part, based on the anaerobic oxidation of methane (AOM). A second variety of methane-derived carbonates was observed in the vicinity of the large carbonate towers and consists of lenticular concretions growing within the sediment (type 2). The concretions are up to several decimeters in size and consist of Mg calcite crystal aggregates that progressively fuse together, thereby incorporating ambient sedimentary matter. Associated biofilms surrounding the concretions clearly show AOM related populations but exhibit a different community structure and a smaller microbial diversity than type 1 carbonates. Type 3 encompasses background sediments irregularly cemented with microcrystalline Mg-calcite (automicrite). These precipitates may show very thin internal biofilms, and are further characterized by small, “birds eye”-type cavities. These cavities appear to arise from ascending gas bubbles, and are partly cemented by granular to blocky Mg calcites. The internal surfaces are frequently coated by thin biofilms resembling those found associated with type 2 concretions. All studied Ca-carbonates have low d13C values (-25 to -35 permille vs. PDB) and show a strong autofluorescence due to inclusions of intracrystalline organic matter. We assume that an increase in carbonate alkalinity due to AOM triggers carbonate precipitation on organic matrices provided by extracellular polymeric substances (EPS). Electron microscopic evidence also suggests that the internal alignment of sugar-rich EPS molecules may control the spatial arrangement of the calcification fabrics observed. EPS remains were extracted from the methane carbonates and the function was tested by in vitro calcification/inhibition experiments.

Longshore Sediment Transport Rate Calculated Incorporating Wave Orbital Velocity Fluctuations

DTIC Science & Technology

2006-09-01

distribution of longshore sediment transport in the surf zone is necessary in the design and planning of groins, jetties, weirs and pipeline landfalls...transported by any current. Breaker height is defined as the vertical distance between the wave crest and the preceding wave trough at incipient...terminology; spilling breakers occur if the wave crest becomes unstable and flows down the front face of the wave producing a foamy water surface; plunging

Evaluating the impacts of logging activities on erosion and suspended sediment transport in the Caspar Creek watersheds

Treesearch

Jack Lewis

1998-01-01

Suspended sediment has been sampled at both the North and South Fork weirs of Caspar Creek in northwestern California since 1963, and at 13 tributary locations in the North Fork since 1986. The North Fork gaging station (NFC) was used as a control to evaluate the effects of logging in the South Fork, in the 1970's, on annual sediment loads. In the most...

American River Watershed Investigation, California. Volume 7. Appendix S. Part 2

DTIC Science & Technology

1991-12-01

towhee Pipilo erythrophthalmus C,U,F Brown towhee Pipilo fuscus C,U,F Rufous-crowned sparrow Aimophila ruficeps C,R Chipping sparrow Spizella passerina C,R...developed as a result of the changes to this agricultural system . According to Estep (1989b), prey density and availability change with the cycles of crop...and Levee ............... 13 12. Modify Sacramento Weir and Bypass ........... ... 14 13. Sacramento River Flood Control System ....... ... 15 14

Engineers Far from Ordinary: The U.S. Army Corps of Engineers in St. Louis

DTIC Science & Technology

2011-09-01

to respond to disasters also grew. The St. Louis District had become increasingly involved in emergency activities as a result of these requirements...dikes, bendway weirs, tree screens, and environmental pool management were developed or implemented at St. Louis District as a result of their...estab- lished Fort Clark near Peoria, named for Governor Clark. The threat of war, primarily with Native American allies of the British, resulted in

High Angle-of-Attack Aerodynamics

DTIC Science & Technology

1982-12-01

CONTRIBUTIONS DE TROIS MOUVEMENTS SIMPLES: UN MOUVEMENT DE BASE CONIQUE ET DES PERTURBATIONS OSCILLATOIRES DE CE MOUVEMENT DE BASE. RECOMMANDATIONS...Completes. Tome 1. 1879, p. CVI. 21. Poincari, H., "Les courbes d6finies par une 6quation dlffer~ntielle." Journal de Math6matigues 3 to 7, 1881, p...profila, ailes en flLche * corps fuselds, primes dWeir, aviona, complete, etc... im~ntrent que lee procidds adoptis aont en meaure de couvrir un domaine

New insights into the spatial variability of biofilm communities and potentially negative bacterial groups in hydraulic concrete structures.

PubMed

Cai, Wei; Li, Yi; Niu, Lihua; Zhang, Wenlong; Wang, Chao; Wang, Peifang; Meng, Fangang

2017-10-15

The composition and distribution characteristics of bacterial communities in biofilms attached to hydraulic concrete structure (HCS) surfaces were investigated for the first time in four reservoirs in the middle and lower reaches of the Yangtze River Basin using 16S rRNA Miseq sequencing. High microbial diversity was found in HCS biofilms, and notable differences were observed in different types of HCS. Proteobacteria, Cyanobacteria and Chloroflexi were the predominant phyla, with respective relative abundances of 35.3%, 25.4% and 13.0%. The three most abundant genera were Leptolyngbya, Anaerolineaceae and Polynucleobacter. The phyla Beta-proteobacteria and Firmicutes and genus Lyngbya were predominant in CGP, whereas the phyla Cyanobacteria and Chloroflexi and genera Leptolyngbya, Anaerolinea and Polynucleobacter survived better in land walls and bank slopes. Dissolved oxygen, ammonia nitrogen and temperature were characterized as the main factors driving the bacterial community composition. The most abundant groups of metabolic functions were also identified as ammonia oxidizers, sulphate reducers, and dehalogenators. Additionally, functional groups related to biocorrosion were found to account for the largest proportion (14.0% of total sequences) in gate piers, followed by those in land walls (11.5%) and bank slopes (10.2%). Concrete gate piers were at the greatest risk of biocorrosion with the most abundant negative bacterial groups, especially for sulphate reducers. Thus, it should be paid high attention to the biocorrosion prevention of concrete gate piers. Overall, this study contributed to the optimization of microbial control and the improvement of the safety management for water conservation structures. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Trend Toward Free Trade Areas: Economic Consequences and Policy Implications for the United States

DTIC Science & Technology

1992-12-01

more efficient producers to gain large economic rents. Subsidy funding is supported by artificially high consumer pric~s or money from public budgets. If...goods and services.214 With respect to trade diversion they further expound that losses accrue to consumers : ... as imports are now purchased from... organization that has taken concrete steps toward an Asian FTA, and because of space limitations, the other groupings are not considered in this document

2. Photocopy of Photograph, c. 1980. VIEW LOOKING WEST ALONG ...

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

2. Photocopy of Photograph, c. 1980. VIEW LOOKING WEST ALONG THE SAN FRANCISCO CANAL. NOTE THE COTTONWOOD TREE IN THE DISTANCE. THESE TREES ORIGINALLY LINED THE CANAL TO PREVENT EVAPORATION. WHEN IT WAS DISCOVERED THAT THE TREES' ROOTS SOAKED UP MORE WATER THAN THEIR SHADE PROTECTED, THEY WERE CUT DOWN. Photographer: Mark Durben, June 1986 Source: Salt River Project Archives - San Francisco Canal, Between Fortieth & Weir & Thirty-sixth Street & Roeser Road, Phoenix, Maricopa County, AZ

Methodology for predicting maximum velocity and shear stress in a sinuous channel with bendway weirs using 1-D HEC-RAS modeling results

Treesearch

Paul Sclafani

2011-01-01

The Middle Rio Grande is a 29-mi reach of the Rio Grande River in central New Mexico that extends from downstream of Cochiti Dam to Bernalillo, New Mexico. A series of anthropogenic factors including the construction of flood control levees and Cochiti Dam have altered the historically-braided morphology of the Middle Rio Grande to a more sinuous, degrading reach, with...

Geophysical Investigation in Support of Beaver Dam Comprehensive Seepage Investigation.

DTIC Science & Technology

1988-05-01

pervasive rather than occurring in a few well defined cond’iits. Ceophyslea1 evidonce su-- gests that the south bounding fault may act as a broad ...K. Butler, Messrs. J. R. Curro, Jr., J. L. Llopis, D. E. Yule, and M. K. Sharp , EEGD. Messrs. C. M. Deaver and S. C. Hartung, SWL, supervised the...measures. These measurements were accomplished by installing two weirs , a Parshall flume, and twenty-seven piezometers. The data suggested that the

Continuous Manufacturing of Nitrocellulose by Magnesium Nitrate Method. Volume 1

DTIC Science & Technology

1979-06-01

enters a scrubber . The scrubber removes entrained acid, water, and NC fines from the air before it enters a Roots water sealed (lobe type) vacuum pump...and is exhausted to the atmosphere. The air enters the bottom of the scrubber and is forced (by vacuum) sequentially through two weir arrangements...the panel from left to right, the Eimco dewatering filter drive, vacuum pressure, receiver, vacuum scrubber , and pump controls may be seen along with

Greenville Bridge Reach, Bendway Weirs

DTIC Science & Technology

2006-09-01

However, these receivers are more expensive and heavier due to the radio and batteries. For this study, two Magellan GPS ProMARK X-CP receivers were...used to collect float data. The Magellan GPS ProMARK X-CP is a small, robust, light receiver that can log 9 hr of both pseudorange and car- rier phase...require a high degree of accu- racy. Using post-processing software, pseudorange GPS data recorded by the ProMARK X-CP can be post-processed

American River Watershed Investigation, California. Volume 6. Appendix S. Part 1

DTIC Science & Technology

1991-12-01

Aimophila ruficeps C,R Chipping sparrow Spizella passerina C,R,W,F Major wildlife habitats of the American River Watershed Study Area include: riparian (R...Lazuli bunting Passerina amoena R,G,W,F Rufous-sided towhee Pipilo erythrophthalmus C,U,F Brown towhee Pipilo fuscus C,U,F Rufous-crowned sparrow ... system of canals, weirs, levees, pumping plants and other facilities to protect agricultural lands in the area by managing flood waters and

Species Profiles. Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (North Atlantic). Alewife/Blueback Herring.

DTIC Science & Technology

1986-07-01

The fish temporarily lost their (1973), designed to test the effects ability to osmoregulate when exposed of suspended sediments on the hatching to...moving through a efficient osmoregulators in either pool-and-weir fishway, indicated environment (Stanley and Colby 1971). moderate activity and...J. E., J. P. Miller, and J. electrolyte balance and Davis 1969. Distribution of osmoregulation in the alewife in juvenile river herring in thefresh

The Value of Georeferenced Collection Records for Predicting Patterns of Mosquito Species Richness and Endemism in the Neotropics

DTIC Science & Technology

2008-01-01

and insect- pollinated plants in Britain and the Netherlands . Science , 313 , 351 – 354 . Belkin , J.N . ( 1962 ) The Mosquitoes of the South...monitoring of biodiversity change . Trends in Ecology and Evolution , 21 , 123 – 129 . Qu , F.-Y. & Qian , G.-Z. ( 1989 ) Faunistic...Trends in Ecology and Evolution , 18 , 306 – 314 . Weir , J.T. & Schluter , D . ( 2007 ) The latitudinal gradient in recent spe- ciation and

Historical Analysis of the Battle of Little Bighorn Utilizing the Joint Conflict and Tactical Simulation (JCATS)

DTIC Science & Technology

2004-06-01

Frank Giordano , whose enlightening instruction and contagious enthusiasm in mathematical modeling provided us with the tools and concepts needed to...for each weapon, as taught by Brigadier General (Retired) Frank Giordano and Dr. Maurice Weir, authors of Mathematical Modeling and professors at...decision was to use the estimate given by Scott in a separate article he authored with Melissa A. Connor titled “Post-mortem at the Little Bighorn

Kansas coal distribution, resources, and potential for coalbed methane

USGS Publications Warehouse

Brady, L.L.

2000-01-01

100 ft (>30 m)] determined from 32 different coal beds. Strippable coal resources at a depth Kansas has large amounts of bituminous coal both at the surface and in the subsurface of eastern Kansas. Preliminary studies indicate at least 53 billion tons (48 billion MT) of deep coal [>100 ft (>30 m)] determined from 32 different coal beds. Strippable coal resources at a depth < 100 ft (<30 m) total 2.8 billion tons (2.6 billion MT), and this total is determined from 17 coals. Coal beds present in the Cherokee Group (Middle Pennsylvanian) represent most of these coal resource totals. Deep coal beds with the largest resource totals include the Bevier, Mineral, "Aw" (unnamed coal bed), Riverton, and Weir-Pittsburg coals, all within the Cherokee Group. Based on chemical analyses, coals in the southeastern part of the state are generally high volatile A bituminous, whereas coals in the east-central and northeastern part of the state are high-volatile B bituminous coals. The primary concern of coal beds in Kansas for deep mining or development of coalbed methane is the thin nature [<2 ft (0.6 m)] of most coal beds. Present production of coalbed methane is centered mainly in the southern Wilson/northern Montgomery County area of southeastern Kansas where methane is produced from the Mulky, Weir-Pittsburg, and Riverton coals.

Sustainable Improvement of Urban River Network Water Quality and Flood Control Capacity by a Hydrodynamic Control Approach-Case Study of Changshu City

NASA Astrophysics Data System (ADS)

Xie, Chen; Yang, Fan; Liu, Guoqing; Liu, Yang; Wang, Long; Fan, Ziwu

2017-01-01

Water environment of urban rivers suffers degradation with the impacts of urban expansion, especially in Yangtze River Delta. The water area in cites decreased sharply, and some rivers were cut off because of estate development, which brings the problems of urban flooding, flow stagnation and water deterioration. The approach aims to enhance flood control capability and improve the urban river water quality by planning gate-pump stations surrounding the cities and optimizing the locations and functions of the pumps, sluice gates, weirs in the urban river network. These gate-pump stations together with the sluice gates and weirs guarantee the ability to control the water level in the rivers and creating hydraulic gradient artificially according to mathematical model. Therefore the flow velocity increases, which increases the rate of water exchange, the DO concentration and water body self-purification ability. By site survey and prototype measurement, the river problems are evaluated and basic data are collected. The hydrodynamic model of the river network is established and calibrated to simulate the scenarios. The schemes of water quality improvement, including optimizing layout of the water distribution projects, improvement of the flow discharge in the river network and planning the drainage capacity are decided by comprehensive Analysis. Finally the paper introduces the case study of the approach in Changshu City, where the approach is successfully implemented.

Numerical analysis of the performance of rock weirs: Effects of structure configuration on local hydraulics

USGS Publications Warehouse

Holmquist-Johnson, C. L.

2009-01-01

River spanning rock structures are being constructed for water delivery as well as to enable fish passage at barriers and provide or improve the aquatic habitat for endangered fish species. Current design methods are based upon anecdotal information applicable to a narrow range of channel conditions. The complex flow patterns and performance of rock weirs is not well understood. Without accurate understanding of their hydraulics, designers cannot address the failure mechanisms of these structures. Flow characteristics such as jets, near bed velocities, recirculation, eddies, and plunging flow govern scour pool development. These detailed flow patterns can be replicated using a 3D numerical model. Numerical studies inexpensively simulate a large number of cases resulting in an increased range of applicability in order to develop design tools and predictive capability for analysis and design. The analysis and results of the numerical modeling, laboratory modeling, and field data provide a process-based method for understanding how structure geometry affects flow characteristics, scour development, fish passage, water delivery, and overall structure stability. Results of the numerical modeling allow designers to utilize results of the analysis to determine the appropriate geometry for generating desirable flow parameters. The end product of this research will develop tools and guidelines for more robust structure design or retrofits based upon predictable engineering and hydraulic performance criteria. ?? 2009 ASCE.

African-American Congregational Care and Counseling: Transcending Universal and Culturally-Specific Barriers.

PubMed

Armstrong, Tonya D

2016-06-01

This article addresses two major African-American congregational care needs: (1) helping suffering people to access sustained mental health care, particularly in a large/mega-church; and (2) helping suffering people with multi-layered challenges to access appropriate, skilled care that transcends traditional barriers and is consistent with their faith. One model of congregational care is presented with concrete examples of how cultural, theological, and strategic concerns are discussed, with broad implications for diverse faith communities. © The Author(s) 2016.

Measurement of dissolved Cs-137 in stream water, soil water and groundwater at Headwater Forested Catchment in Fukushima after Fukushima Dai-ichi Nuclear Power Plant Accident

NASA Astrophysics Data System (ADS)

Iwagami, Sho; Tsujimura, Maki; Onda, Yuichi; Sakakibara, Koichi; Konuma, Ryohei; Sato, Yutaro

2016-04-01

Radiocesium migration from headwater forested catchment is important perception as output from the forest which is also input to the subsequent various land use and downstream rivers after Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident. In this study, dissolved Cs-137 concentration of stream water, soil water and groundwater were measured. Observations were conducted at headwater catchment in Yamakiya district, located 35 km northwest of FDNPP from April 2014 to November 2015. Stream water discharge was monitored and stream water samples were taken at main channel and sub channel. Stream water discharge was monitored by combination of parshallflume and v-notch weir. Stream water was sampled manually at steady state condition in 3-4 month interval and also intense few hours interval sampling were conducted during rainfall events using automated water sampler. Around the sub channel, it is found that there is a regularly saturated area at the bottom of the slope, temporary saturated area which saturate during the rainy season in summer and regularly dry area. 6 interval cameras were installed to monitor the changing situation of saturated area. Suction lysimeters were installed at three areas (regularly saturated area, temporary saturated area and dry area) for sampling soil water in depth of 0.1 m and 0.3 m. Boreholes were installed at three points along the sub channel. Three boreholes with depth of 3 m, 5 m and 10 m were installed at temporary saturated area, 20 m upstream of sub channel weir. Another three boreholes with depth of 3 m, 5 m and 10 m were installed at dry area, 40 m upstream of sub channel weir. And a borehole with depth of 20 m was installed at ridge of sub catchment, 52 m upstream of sub channel weir. Groundwater was sampled by electrically powered pump and groundwater level was monitored. Also suction-free lysimeter was installed at temporary saturated area for sampling the near surface subsurface water. Soil water samples were collected as much as collected in flask. Stream water and groundwater samples were collected for 40 L each. All the water samples were filtered through 0.45 μm pore-size membrane. Water samples with less than few L were concentrated by evaporative concentration. Water samples with more than 40 L were concentrated using the ammonium molybdophosphate (AMP)/Cs compound method. The Cs-137 concentration was determined using gamma-ray spectrometry with a germanium semiconductor detector. Spatial distribution of dissolved Cs-137 concentration in the slope was obtained and the source of Cs-137 concentration in stream water was examined. The Cs-137 concentration in groundwater showed low value of 0.0004-0.001 Bq/L. The Cs-137 concentration of soil water showed 0.01-0.1 Bq/L. And Cs-137 concentrations of stream water were 0.007-0.03 Bq/L at steady state condition. Also Cs-137 concentrations in stream water showed temporary increase during rainfall event. The source of dissolved Cs-137 was suggested to be shallow soil water under saturated condition or leaching from the litter might be affecting.

An approach for assessment of water quality using semipermeable membrane devices (SPMDs) and bioindicator tests

USGS Publications Warehouse

Petty, J.D.; Jones, S.B.; Huckins, J.N.; Cranor, W.L.; Parris, J.T.; McTague, T.B.; Boyle, T.P.

2000-01-01

As an integral part of our continued development of water quality assessment approaches, we combined integrative sampling, instrumental analysis of widely occurring anthropogenic contaminants, and the application of a suite of bioindicator tests as a specific part of a broader survey of ecological conditions, species diversity, and habitat quality in the Santa Cruz River in Arizona, USA. Lipid-containing semipermeable membrane devices (SPMDs) were employed to sequester waterborne hydrophobic chemicals. Instrumental analysis and a suite of bioindicator tests were used to determine the presence and potential toxicological relevance of mixtures of bioavailable chemicals in two major water sources of the Santa Cruz River. The SPMDs were deployed at two sites; the effluent weir of the International Wastewater Treatment Plant (IWWTP) and the Nogales Wash. Both of these systems empty into the Santa Cruz River and the IWWTP effluent is a potential source of water for a constructed wetland complex. Analysis of the SPMD sample extracts revealed the presence of organochlorine pesticides (OCs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). The bioindicator tests demonstrated increased liver enzyme activity, perturbation of neurotransmitter systems and potential endocrine disrupting effects (vitellogenin induction) in fish exposed to the extracts. With increasing global demands on limited water resources, the approach described herein provides an assessment paradigm applicable to determining the quality of water in a broad range of aquatic systems.

A diverse assemblage of fossil hardwood from the Upper Tertiary (Miocene?) of the Arauco Peninsula, Chile

NASA Astrophysics Data System (ADS)

Schöning, Meike; Bandel, Klaus

2004-09-01

Silicified woods of 10 dicotyledonous tree families of probably Miocene age from the Arauco Peninsula, central Chile are described and classified according to their anatomy. The diversity is surprisingly high, in that of the 19 samples analyzed, virtually every one could belong to a different species of tree or shrub. Almost all species document a damp climate, and most have related species living in the central zone of modern Chile. The samples were collected in a narrow zone on Punta El Fraile, west of the town of Arauco. The following families are based on woods from the Arauco Peninsula: Anacardiaceae, Boraginaceae, Euphorbiaceae, Fagaceae, Lauraceae, Leguminosae, Monimiaceae, the first report of fossil Myristicaceae, Myrtaceae, and Proteaceae. Their diagenetic history is connected to tuffaceous material and calcareous concretions.

Metaphor, symbolic play, and logical thought in early childhood.

PubMed

Seitz, J A

1997-11-01

Development of the ability to understand diverse types of metaphor was examined in terms of play context (symbolic vs. constructive-object play), Piagetian operational level (preoperational vs. concrete-operational), and medium of presentation (pictures vs. words). Forty 4-year-olds and 80 6-year-olds (40 preoperational, 40 concrete-operational) were presented with six different types of metaphorical relationships (color, shape, physiognomic, cross-modal, psychological-physical, and taxonomic matches) in both pictures and words in a match-to-sample design. Results indicated that (a) constructive-object play, rather than symbolic play, facilitated the understanding of perceptual and taxonomic metaphor, suggesting differences in early styles of metaphoric usage; (b) despite previous findings, the study failed to replicate a relationship between operativity and metaphoric understanding; and (c) younger children did significantly better in the pictorial medium, suggesting a picture-superiority effect for more perceptible metaphorical relations (perceptual and physiognomic), whereas older children showed a word-superiority effect for more conceptual metaphors (psychological-physical and taxonomic).

Role of physical barriers in the control of sea lamprey (Petromyzon marinus)

USGS Publications Warehouse

Hunn, J.B.; Youngs, W.D.

1980-01-01

Mechanical and electromechanical barriers played a significant role in the initial attempts to control sea lamprey (Petromyzon marinus) populations in the upper Great Lakes. More recently electromechanical weirs have been used to assess the relative abundance of spawning-run sea lampreys in Lake Superior. Development of an integrated control approach to sea lamprey control has stimulated an ongoing research program to define structural and/or velocity criteria that can be used to design barrier dams that block spawning runs of sea lamprey

Cooling water distribution system

DOEpatents

Orr, Richard

1994-01-01

A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using an interconnected series of radial guide elements, a plurality of circumferential collector elements and collector boxes to collect and feed the cooling water into distribution channels extending along the curved surface of the steel containment vessel. The cooling water is uniformly distributed over the curved surface by a plurality of weirs in the distribution channels.

Retrenchment: General Russell E. Dougherty and the Strategic Air Command During the Age of Detente

DTIC Science & Technology

2014-06-01

could reschedule for the next day. Dougherty noted he was unable to stay in Washington for an 38...their aid. The wife turned out to be a nurse and she tore strips from the dress she was wearing to stop Dougherty’s bleeding. Weir landed in a...bought a new dress and mailed it to the nurse who ruined her own dress in her efforts to aid him and his friend.94 Dougherty still had one arm in a

Solid fuel feed system for a fluidized bed

DOEpatents

Jones, Brian C.

1982-01-01

A fluidized bed for the combustion of coal, with limestone, is replenished with crushed coal from a system discharging the coal laterally from a station below the surface level of the bed. A compartment, or feed box, is mounted at one side of the bed and its interior separated from the bed by a weir plate beneath which the coal flows laterally into the bed while bed material is received into the compartment above the plate to maintain a predetermined minimum level of material in the compartment.

Work-Family Conflict: The Effect of Job and Family Involvement

DTIC Science & Technology

1986-11-01

helping relationships: The moderators between stress and well-being. Journal of EYsb2o!9Y, 2§ 121-130. Burke, R . J., Weir, T. J., & Duwors, R . E ...of conflict between work and family roles. Academy o2f anagement Review, 10, 76-88. Greenhaus, J. H., & Kopelman, R . E . (1981). Conflict between work...341-349. Kanungo, R . N. (1982b). Work alienation: An in2Srjy2 ARPEgAgh- New York: Praeger. Lawler, E . E ., & Hall, D. T. (1970). Relationship of job

Ecological Effects of Rubble Weir Jetty Construction at Murrells Inlet, South Carolina. Volume 2. Changes in Macrobenthic Communities of Sandy Beach and Nearshore ENvironments.

DTIC Science & Technology

1984-06-01

species were not commonly observed, and oligochaetes and nematodes were abundant in the area. Rany of these differences were attributed to normal...1977-78 (Table 3). Subtidally, amphipods and pelecypods were most abundant in 1982, while oligochaetes and nematodes largely dominated the intertidal...generally restricted to that level and the highest intertidal level (Table 10). Nematodes were also abundant in the upper intertidal zone, with greatest

Lab on a Chip Packing of Submicron Particles for High Performance EOF Pumping

DTIC Science & Technology

2010-08-26

and wet etching techniques, using a soda lime glass substrate coated with chromium and photoresist (Nanofilm, Westlake Village, CA). A weir structure...observed previously for these soda lime glass microchips [8]. Images of the three segments of different sized particles con- tainedwithin the packed... Silica beads High pressure Lab on a chip a b s t r a c t The packing of submicrometer sized silica beads inside a microchannel was enabled by a novel

Single Cell Dissection of Human Pancreatic Islet Dysfunction in Diabetes

DTIC Science & Technology

2017-06-01

of memory T cells , innate cells and the differentiation potential of naive T cells during ME/CFS; and 3) To determine the T cell and innate cell ...apoptosis and the innate immune response in human pancreatic β- cells . Diabetes 64: 3808–3817. Marselli L, Thorne J, Dahiya S, Sgroi DC, Sharma A, Bonner-Weir...interactive nature of CellView aids in cell doublet identification. In the PBMC data, ‘Subcluster-analysis’ reveals a mixture of lymphoid and myeloid

Management plan for White Oak Dam. Revision 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmed, S.B.

1997-03-01

The purpose is to provide operation and maintenance, periodic inspection, and emergency action plans for White Oak Dam in general accordance with the Federal Emergency Management Agency (FEMA) guidelines for dam safety. It must be understood that operations at the site are primarily for purposes of environmental monitoring, environmental protection and waste management operations control. Effluent is generally allowed to flow from the lake at its natural rate by rising above the broad crested weir notch elevation of 744 feet m.s.l.

Pyrolysis with cyclone burner

DOEpatents

Green, Norman W.; Duraiswamy, Kandaswamy; Lumpkin, Robert E.

1978-07-25

In a continuous process for recovery of values contained in a solid carbonaceous material, the carbonaceous material is comminuted and then subjected to flash pyrolysis in the presence of a particulate heat source over an overflow weir to form a pyrolysis product stream containing a carbon containing solid residue and volatilized hydrocarbons. After the carbon containing solid residue is separated from the pyrolysis product stream, values are obtained by condensing volatilized hydrocarbons. The particulate source of heat is formed by oxidizing carbon in the solid residue and separating out the fines.

Pyrolysis with staged recovery

DOEpatents

Green, Norman W.; Duraiswamy, Kandaswamy; Lumpkin, Robert E.; Winter, Bruce L.

1979-03-20

In a continuous process for recovery of values contained in a solid carbonaceous material, the carbonaceous material is comminuted and then subjected to flash pyrolysis in the presence of a particulate heat source fed over an overflow weir to form a pyrolysis product stream containing a carbon containing solid residue and volatilized hydrocarbons. After the carbon containing solid residue is separated from the pyrolysis product stream, values are obtained by condensing volatilized hydrocarbons. The particulate source of heat is formed by oxidizing carbon in the solid residue.

16. Photographic copy of photograph. (Source: U.S. Department of Interior. ...

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

16. Photographic copy of photograph. (Source: U.S. Department of Interior. Office of Indian Affairs. Indian Irrigation Service. Annual Report, Fiscal Year 1925. Vol, I, Narrative and Photographs, Irrigation District #4, California and Southern Arizona, RG 75, Entry 655, Box 28, National Archives, Washington, DC.) Photographer unknown. SACATON DAM AND BRIDGE, SHOWING WEIR APRONS AND BRIDGE, 6/18/25. - San Carlos Irrigation Project, Sacaton Dam & Bridge, Gila River, T4S R6E S12/13, Coolidge, Pinal County, AZ

17. Photographic copy of photograph. (Source: U.S. Department of Interior. ...

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

17. Photographic copy of photograph. (Source: U.S. Department of Interior. Office of Indian Affairs. Indian Irrigation Service. Annual Report, Fiscal Year 1925. Vol. I, Narrative and Photographs, Irrigation District #4, California and Southern Arizona, RG 75, Entry 655, Box 28, National Archives, Washington, DC.) Photographer unknown. SACATON DAM AND BRIDGE, CONSTRUCTION OF WEIR, 1/17/25 - San Carlos Irrigation Project, Sacaton Dam & Bridge, Gila River, T4S R6E S12/13, Coolidge, Pinal County, AZ

The Lacustrine Upper Brushy Basin Member of the Morrison Formation, Four Corners Region, Usa: a Lithological and Mineralogical Terrestrial Analog for Gale Crater, Mars

NASA Astrophysics Data System (ADS)

Potter-McIntyre, S. L.; Chan, M. A.; McPherson, B. J.

2013-12-01

The upper part of the Jurassic Brushy Basin Member of the Morrison Formation is an iron- and clay-rich volcaniclastic shale deposited in an ephemeral alkaline saline lake system. Sedimentary rocks exposed in Gale Crater consist of similar non-acidic clays, possibly of lacustrine origin. Three primary clastic lithofacies are present in both the Brushy Basin Member and at Gale Crater: silt-/claystone, sandstone, and conglomerate. Both the terrestrial and martian silt-/claystone lithofacies are interpreted as lacustrine depositional environments due to features such as parallel laminated and massive sedimentary structures. Vugs are present in the siltstone/claystone facies on both the Colorado Plateau and at Gale Crater. Fluvial features are also observed in both examples such as cross-bedded sandstones and imbricated conglomerates. Concretions are present in both the Colorado Plateau and Gale Crater units. The vugs in the Brushy Basin Member preserve algal forms with cellular elaboration and are interpreted as charophyte molds. Two distinct suites of elements (1. C, Fe, As, P and, 2. C, S, Se, P) are associated with the microbial fossils and may be potential markers for biosignatures. Vugs at Gale Crater are a potential target to investigate the possibility of preserved microbial (algal) life where early analyses show the presence of the elements capable of supporting life. The Brushy Basin Member is composed predominately of quartz, feldspars, zeolites and altered volcanic ash. The abundant clay minerals in both the terrestrial and martian examples are hypothesized to have formed due to partial alteration of volcanic minerals in alkaline fluid. Similarly, concretions present in the terrestrial unit exhibit a diverse range of mineralogies likely due to alkaline fluid chemistries interacting with reactive volcaniclastic sediments. Terrestrial concretion mineralogy is diverse even within an outcrop or stratigraphic horizon which suggests reactants to precipitate concretions are being sourced from diagenetic micorenvironments. Similar diagenetic microenvironments may be preserved at Gale Crater due to the fine-grained, volcaniclastic (reactive) rocks. The Brushy Basin Member is a valuable analog because comparative iron-and clay-rich compositions help to: 1) understand diagenetic processes in a non-acidic, saline lacustrine environment, 2) document specific sedimentary structures and lithofacies associations to interpret depositional environment, 3) document specific biomediated features (e.g., textures, morphologies, chemistries), and 4) demonstrate how these features might persist or respond to diagenesis over time.

Monitoring channel head erosion processes in response to an artificially induced abrupt base level change using time-lapse photography

NASA Astrophysics Data System (ADS)

Nichols, M. H.; Nearing, M.; Hernandez, M.; Polyakov, V. O.

2016-07-01

Gullies that terminate at a vertical-wall are ubiquitous throughout arid and semiarid regions. Multi-year assessments of gully evolution and headcut advance are typically accomplished using traditional ground surveys and aerial photographs, with much recent research focused on integrating data collected at very high spatial resolutions using new techniques such as aerial surveys with blimps or kites and ground surveys with LiDar scanners. However, knowledge of specific processes that drive headcut advance is limited due to inadequate observation and documentation of flash floods and subsequent erosion that can occur at temporal resolutions not captured through repeat surveys. This paper presents a method for using very-high temporal resolution ground-based time-lapse photography to capture short-duration flash floods and gully head evolution in response. In 2004, a base level controlling concrete weir was removed from the outlet of a 1.29 ha semiarid headwater drainage on the Walnut Gulch Experimental Watershed in southeastern Arizona, USA. During the ten year period from 2004 to 2014 the headcut migrated upchannel a total of 14.5 m reducing the contributing area at the headwall by 9.5%. Beginning in July 2012, time-lapse photography was employed to observe event scale channel evolution dynamics. The most frequent erosion processes observed during three seasons of time-lapse photography were plunge pool erosion and mass wasting through sidewall or channel headwall slumping that occurred during summer months. Geomorphic change during the ten year period was dominated by a single piping event in August 2014 that advanced the channel head 7.4 m (51% of the overall advance) and removed 11.3 m3 of sediment. High temporal resolution time-lapse photography was critical for identifying subsurface erosion processes, in the absence of time-lapse images piping would not have been identified as an erosion mechanism responsible for advancing the gully headwall at this site.

Diagenetic Iron Cycling in Ancient Alkaline Saline Lacustrine Sedimentary Rocks: A Case Study on the Jurassic Brushy Basin Member of the Morrison Formation, Colorado Plateau, USA

NASA Astrophysics Data System (ADS)

Potter-McIntyre, S. L.; Chan, M. A.; McPherson, B. J. O. L.

2014-12-01

The upper part of the Brushy Basin Member in the Four Corners region of the U.S. was deposited in an ephemeral alkaline saline lake system with copious input of volcanic ash. The variegated shale formation provides a setting for the study of early diagenetic iron cycling that records the action of alkaline saline fluid chemistries reacting with volcaniclastic sediments in the presence of microbes. A bull's-eye pattern of authigenic minerals with increasing alteration towards the basinal center similar to modern alkaline saline lakes provides evidence for an extreme paleoenvironmental interpretation. The purpose of this research is to document specific factors, such as reactive sediments, microbial influences, and grain size that affect concretion formation and iron cycling in an ancient extreme environment. Three broad diagenetic facies are interpreted by color and associated bioturbation features: red, green and intermediate. Diagenetic facies reflect meter-scale paleotopography: red facies represent shallow water to subaerial, oxidizing conditions; green facies reflect saturated conditions and reducing pore water chemistry shortly after deposition, and intermediate facies represent a combination of the previous two conditions. Evidence of biotic influence is abundant and trace fossils exhibit patterns associated with the diagenetic facies. Red diagenetic facies typically contain burrows and root traces and green diagenetic facies exhibit restricted biotic diversity typically limited to algal molds (vugs). Microbial fossils are well-preserved and are in close proximity to specific iron mineral textures suggesting biotic influence on the crystal morphology. Three categories of concretions are characterized based on mineralogy: carbonate, iron (oxyhydr)oxide and phosphate concretions. Concretion mineralogy and size vary within an outcrop and even within a stratigraphic horizon such that more than one main category is typically present in an outcrop. Variation in concretion mineralogy and morphology within the Brushy Basin Member suggests that alkaline saline fluid chemistries in concert with microbial interaction created diagenetic microenvironments within a larger lake system to influence iron cycling and these reactions can be spatially variable even on 10s of cm scales.

Prokaryotic diversity and biogeochemical characteristics of benthic microbial ecosystems at La Brava, a hypersaline lake at Salar de Atacama, Chile.

PubMed

Farias, Maria Eugenia; Rasuk, Maria Cecilia; Gallagher, Kimberley L; Contreras, Manuel; Kurth, Daniel; Fernandez, Ana Beatriz; Poiré, Daniel; Novoa, Fernando; Visscher, Pieter T

2017-01-01

Benthic microbial ecosystems of Laguna La Brava, Salar de Atacama, a high altitude hypersaline lake, were characterized in terms of bacterial and archaeal diversity, biogeochemistry, (including O2 and sulfide depth profiles and mineralogy), and physicochemical characteristics. La Brava is one of several lakes in the Salar de Atacama where microbial communities are growing in extreme conditions, including high salinity, high solar insolation, and high levels of metals such as lithium, arsenic, magnesium, and calcium. Evaporation creates hypersaline conditions in these lakes and mineral precipitation is a characteristic geomicrobiological feature of these benthic ecosystems. In this study, the La Brava non-lithifying microbial mats, microbialites, and rhizome-associated concretions were compared to each other and their diversity was related to their environmental conditions. All the ecosystems revealed an unusual community where Euryarchaeota, Crenarchaeota, Acetothermia, Firmicutes and Planctomycetes were the most abundant groups, and cyanobacteria, typically an important primary producer in microbial mats, were relatively insignificant or absent. This suggests that other microorganisms, and possibly novel pathways unique to this system, are responsible for carbon fixation. Depth profiles of O2 and sulfide showed active production and respiration. The mineralogy composition was calcium carbonate (as aragonite) and increased from mats to microbialites and rhizome-associated concretions. Halite was also present. Further analyses were performed on representative microbial mats and microbialites by layer. Different taxonomic compositions were observed in the upper layers, with Archaea dominating the non-lithifying mat, and Planctomycetes the microbialite. The bottom layers were similar, with Euryarchaeota, Crenarchaeota and Planctomycetes as dominant phyla. Sequences related to Cyanobacteria were very scarce. These systems may contain previously uncharacterized community metabolisms, some of which may be contributing to net mineral precipitation. Further work on these sites might reveal novel organisms and metabolisms of biotechnological interest.

Prokaryotic diversity and biogeochemical characteristics of benthic microbial ecosystems at La Brava, a hypersaline lake at Salar de Atacama, Chile

PubMed Central

Rasuk, Maria Cecilia; Gallagher, Kimberley L.; Contreras, Manuel; Kurth, Daniel; Fernandez, Ana Beatriz; Poiré, Daniel; Novoa, Fernando; Visscher, Pieter T.

2017-01-01

Benthic microbial ecosystems of Laguna La Brava, Salar de Atacama, a high altitude hypersaline lake, were characterized in terms of bacterial and archaeal diversity, biogeochemistry, (including O2 and sulfide depth profiles and mineralogy), and physicochemical characteristics. La Brava is one of several lakes in the Salar de Atacama where microbial communities are growing in extreme conditions, including high salinity, high solar insolation, and high levels of metals such as lithium, arsenic, magnesium, and calcium. Evaporation creates hypersaline conditions in these lakes and mineral precipitation is a characteristic geomicrobiological feature of these benthic ecosystems. In this study, the La Brava non-lithifying microbial mats, microbialites, and rhizome-associated concretions were compared to each other and their diversity was related to their environmental conditions. All the ecosystems revealed an unusual community where Euryarchaeota, Crenarchaeota, Acetothermia, Firmicutes and Planctomycetes were the most abundant groups, and cyanobacteria, typically an important primary producer in microbial mats, were relatively insignificant or absent. This suggests that other microorganisms, and possibly novel pathways unique to this system, are responsible for carbon fixation. Depth profiles of O2 and sulfide showed active production and respiration. The mineralogy composition was calcium carbonate (as aragonite) and increased from mats to microbialites and rhizome-associated concretions. Halite was also present. Further analyses were performed on representative microbial mats and microbialites by layer. Different taxonomic compositions were observed in the upper layers, with Archaea dominating the non-lithifying mat, and Planctomycetes the microbialite. The bottom layers were similar, with Euryarchaeota, Crenarchaeota and Planctomycetes as dominant phyla. Sequences related to Cyanobacteria were very scarce. These systems may contain previously uncharacterized community metabolisms, some of which may be contributing to net mineral precipitation. Further work on these sites might reveal novel organisms and metabolisms of biotechnological interest. PMID:29140980

Brood Year 2004: Johnson Creek Chinook Salmon Supplementation Report, June 2004 through March 2006.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gebhards, John S.; Hill, Robert; Daniel, Mitch

The Nez Perce Tribe, through funding provided by the Bonneville Power Administration, has implemented a small scale chinook salmon supplementation program on Johnson Creek, a tributary in the South Fork of the Salmon River, Idaho. The Johnson Creek Artificial Propagation Enhancement project was established to enhance the number of threatened Snake River spring/summer chinook salmon (Oncorhynchus tshawytscha) returning to Johnson Creek to spawn through artificial propagation. This was the sixth season of adult chinook broodstock collection in Johnson Creek following collections in 1998, 2000, 2001, 2002, and 2003. Weir installation was completed on June 21, 2004 with the first chinookmore » captured on June 22, 2004 and the last fish captured on September 6, 2004. The weir was removed on September 18, 2004. A total of 338 adult chinook, including jacks, were captured during the season. Of these, 211 were of natural origin, 111 were hatchery origin Johnson Creek supplementation fish, and 16 were adipose fin clipped fish from other hatchery operations and therefore strays into Johnson Creek. Over the course of the run, 57 natural origin Johnson Creek adult chinook were retained for broodstock, transported to the South Fork Salmon River adult holding and spawning facility and held until spawned. The remaining natural origin Johnson Creek fish along with all the Johnson Creek supplementation fish were released upstream of the weir to spawn naturally. Twenty-seven Johnson Creek females were artificially spawned with 25 Johnson Creek males. Four females were diagnosed with high bacterial kidney disease levels resulting in their eggs being culled. The 27 females produced 116,598 green eggs, 16,531 green eggs were culled, with an average eye-up rate of 90.6% resulting in 90,647 eyed eggs. Juvenile fish were reared indoors at the McCall Fish Hatchery until November 2005 and then transferred to the outdoor rearing facilities during the Visual Implant Elastomer tagging operation. These fish continued rearing in the outdoor collection basin until release in March 2006. All of these fish were marked with Coded Wire Tags and Visual Implant Elastomer tags. In addition 12,056 of the smolts released were also tagged with Passive Integrated Transponder tags. Hand counts provided by marking crews were used to amend the number of juvenile salmon released from the original egg count. A total of 90,450 smolts were released directly into Johnson Creek on March 13 through 15, 2006.« less

Decision-making in irrigation networks: Selecting appropriate canal structures using multi-attribute decision analysis.

PubMed

Hosseinzade, Zeinab; Pagsuyoin, Sheree A; Ponnambalam, Kumaraswamy; Monem, Mohammad J

2017-12-01

The stiff competition for water between agriculture and non-agricultural production sectors makes it necessary to have effective management of irrigation networks in farms. However, the process of selecting flow control structures in irrigation networks is highly complex and involves different levels of decision makers. In this paper, we apply multi-attribute decision making (MADM) methodology to develop a decision analysis (DA) framework for evaluating, ranking and selecting check and intake structures for irrigation canals. The DA framework consists of identifying relevant attributes for canal structures, developing a robust scoring system for alternatives, identifying a procedure for data quality control, and identifying a MADM model for the decision analysis. An application is illustrated through an analysis for automation purposes of the Qazvin irrigation network, one of the oldest and most complex irrigation networks in Iran. A survey questionnaire designed based on the decision framework was distributed to experts, managers, and operators of the Qazvin network and to experts from the Ministry of Power in Iran. Five check structures and four intake structures were evaluated. A decision matrix was generated from the average scores collected from the survey, and was subsequently solved using TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) method. To identify the most critical structure attributes for the selection process, optimal attribute weights were calculated using Entropy method. For check structures, results show that the duckbill weir is the preferred structure while the pivot weir is the least preferred. Use of the duckbill weir can potentially address the problem with existing Amil gates where manual intervention is required to regulate water levels during periods of flow extremes. For intake structures, the Neyrpic® gate and constant head orifice are the most and least preferred alternatives, respectively. Some advantages of the Neyrpic® gate are ease of operation and capacity to measure discharge flows. Overall, the application to the Qazvin irrigation network demonstrates the utility of the proposed DA framework in selecting appropriate structures for regulating water flows in irrigation canals. This framework systematically aids the decision process by capturing decisions made at various levels (individual farmers to high-level management). It can be applied to other cases where a new irrigation network is being designed, or where changes in irrigation structures need to be identified to improve flow control in existing networks. Copyright © 2017 Elsevier B.V. All rights reserved.

Full equations utilities (FEQUTL) model for the approximation of hydraulic characteristics of open channels and control structures during unsteady flow

USGS Publications Warehouse

Franz, Delbert D.; Melching, Charles S.

1997-01-01

The Full EQuations UTiLities (FEQUTL) model is a computer program for computation of tables that list the hydraulic characteristics of open channels and control structures as a function of upstream and downstream depths; these tables facilitate the simulation of unsteady flow in a stream system with the Full Equations (FEQ) model. Simulation of unsteady flow requires many iterations for each time period computed. Thus, computation of hydraulic characteristics during the simulations is impractical, and preparation of function tables and application of table look-up procedures facilitates simulation of unsteady flow. Three general types of function tables are computed: one-dimensional tables that relate hydraulic characteristics to upstream flow depth, two-dimensional tables that relate flow through control structures to upstream and downstream flow depth, and three-dimensional tables that relate flow through gated structures to upstream and downstream flow depth and gate setting. For open-channel reaches, six types of one-dimensional function tables contain different combinations of the top width of flow, area, first moment of area with respect to the water surface, conveyance, flux coefficients, and correction coefficients for channel curvilinearity. For hydraulic control structures, one type of one-dimensional function table contains relations between flow and upstream depth, and two types of two-dimensional function tables contain relations among flow and upstream and downstream flow depths. For hydraulic control structures with gates, a three-dimensional function table lists the system of two-dimensional tables that contain the relations among flow and upstream and downstream flow depths that correspond to different gate openings. Hydraulic control structures for which function tables containing flow relations are prepared in FEQUTL include expansions, contractions, bridges, culverts, embankments, weirs, closed conduits (circular, rectangular, and pipe-arch shapes), dam failures, floodways, and underflow gates (sluice and tainter gates). The theory for computation of the hydraulic characteristics is presented for open channels and for each hydraulic control structure. For the hydraulic control structures, the theory is developed from the results of experimental tests of flow through the structure for different upstream and downstream flow depths. These tests were done to describe flow hydraulics for a single, steady-flow design condition and, thus, do not provide complete information on flow transitions (for example, between free- and submerged-weir flow) that may result in simulation of unsteady flow. Therefore, new procedures are developed to approximate the hydraulics of flow transitions for culverts, embankments, weirs, and underflow gates.

Best Practices for Managing Organizational Diversity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kreitz, Patricia A.; /SLAC

2007-05-18

In the twentieth century, ecologists and agriculturists developed an increasingly sophisticated understanding of the value of biological diversity, specifically the resilience and adaptability it brings to ecosystems. In the twenty-first century, the ecosystem model has been applied to human systems, particularly to understanding how organizations are structured and how they operate. Twenty-first century organizations are challenged by diversity in many arenas. Demographic changes in workforce composition and customer populations, combined with globalized markets and international competition are increasing the amount of diversity organizations must manage, both internally and externally. Many diversity specialists and business leaders argue that businesses and organizationsmore » interested in surviving and thriving in the twenty-first century need to take competitive advantage of a diverse workplace (Soutar, 2004; Yang, 2005). But to do so successfully, leaders and human resources (HR) managers must redefine management and leadership (Jones, 1989). Just as mono-cropping destroys biological diversity, and, in extreme cases, such as the Irish potato famine--human as well as natural ecosystems (Keohane, n.d.), so does mono-managing similarly destroy diversity within organizations. Leaders wanting to build strong, diverse organizations will not be successful if they rely on one approach or solution. Single-threaded diversity solutions, such as focusing only on recruitment or single-approach management techniques, such as requiring every employee to take diversity training, do not create lasting change (Kossek & Lobel, 1996; McMahon, 2006; Thomas, 1990). Bringing about the changes needed to build and sustain diversity requires commitment, strategy, communication, and concrete changes in organizational structure and processes. How, then, can managers and leaders develop diverse organizations and ensure that they are managed to take optimum advantage of diversity? What role should human resource specialists play in creating and managing diverse organizations? What are the best practices they should apply? The purpose of this review is to define workplace diversity, to identify best practices, and to identify how diversity management best practices can be applied in academic libraries. Finally, this review will provide a resource list for HR managers and leaders to learn more about those best practices with the goal of optimizing their organization's approach to diversity.« less

Man-Made Cutoffs on the Lower Mississippi River, Conception, Construction, and River Response.

DTIC Science & Technology

1977-03-01

flows, the middle bar acted like a broad - crested weir and created a backwater effect that could extend many miles ’nstream. The result was less flow in...cutoffs disrupt sinuosity and the sequence of bars and bar spacing. :7o broad conclusive statement can be made to include all rivers, because each river...below mlw and was completed in April 1935, about the time of the crest of the high water of that year. The length of the cut was 13,000 ft, and the

National Dam Inspection Program. North Lake Dam (NDI I.D. Number PA-00268, PennDER I.D. Number 52-180), Delaware River Basin, Branch of Hornbecks Creek, Pike County, Pennsylvania. Phase I Inspection Report,

DTIC Science & Technology

1981-01-01

12 6.1 Visual Observations ..... ............... . 12 6.2 Design and Construction Techniques .......... . 13 6.3 Past Performance...Techniques. No information is available that details the methods of design and/or construction. 6.3 Past Performance. No records relative to the...Inc., New York, 1959. 8. Weir Experiments, Coefficients, and Formulas, R. E. Horton, Water Supply and Irrigation Paper No. 200, Department of the

Remaining Sites Verification Package for the 100-F-50 Stormwater Runoff Culvert, Waste Site Reclassification Form 2007-001

DOE Office of Scientific and Technical Information (OSTI.GOV)

J. M. Capron

2008-04-15

The 100-F-50 waste site, part of the 100-FR-2 Operable Unit, is a steel stormwater runoff culvert that runs between two railroad grades in the south-central portion of the 100-F Area. The culvert exiting the west side of the railroad grade is mostly encased in concrete and surrounded by a concrete stormwater collection depression partially filled with soil and vegetation. The drain pipe exiting the east side of the railroad grade embankment is partially filled with soil and rocks. The 100-F-50 stormwater diversion culvert confirmatory sampling results support a reclassification of this site to no action. The current site conditions achievemore » the remedial action objectives and corresponding remedial action goals established in the Remaining Sites ROD. The results of confirmatory sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.« less

A Semantic Cooperation and Interoperability Platform for the European Chambers of Commerce

NASA Astrophysics Data System (ADS)

Missikoff, Michele; Taglino, Francesco

The LD-CAST project aims at developing a semantic cooperation and interoperability platform for the European Chambers of Commerce. Some of the key issues that this platform addresses are: The variety and number of different kinds of resources (i.e., business processes, concrete services) that concur to achieve a business service The diversity of cultural and procedural models emerging when composing articulated cross-country services The limited possibility of reusing similar services in different contexts (for instance, supporting the same service between different countries: an Italian-Romanian cooperation is different from an Italian-Polish one) The objective of the LD-CAST platform, and in particular of the semantic services provided therein, is to address the above problems with flexible solutions. We aim at introducing high levels of flexibility, both at the time of development of business processes and concrete services (i.e., operational services offered by service providers), with the possibility of dynamically binding c-services to the selected BP, according to user needs. To this end, an approach based on semantic services and a reference ontology has been proposed.

Perspective: Towards environmentally acceptable criteria for downstream fish passage through mini hydro and irrigation infrastructure in the Lower Mekong River Basin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baumgartner, Lee J.; Daniel Deng, Z.; Thorncraft, Garry

2014-01-01

Tropical rivers have high annual discharges optimal for hydropower and irrigation development. The Mekong River is one of the largest tropical river systems, supporting a unique mega-diverse fish community. Fish are an important commodity in the Mekong, contributing a large proportion of calcium, protein, and essential nutrients to the diet of the local people and providing a critical source of income for rural households. Many of these fish migrate not only upstream and downstream within main-channel habitats but also laterally into highly productive floodplain habitat to both feed and spawn. Most work to date has focused on providing for upstreammore » fish passage, but downstream movement is an equally important process to protect. Expansion of hydropower and irrigation weirs can disrupt downstream migrations and it is important to ensure that passage through regulators or mini hydro systems is not harmful or fatal. Many new infrastructure projects (<6 m head) are proposed for the thousands of tributary streams throughout the Lower Mekong Basin and it is important that designs incorporate the best available science to protect downstream migrants. Recent advances in technology have provided new techniques which could be applied to Mekong fish species to obtain design criteria that can facilitate safe downstream passage. Obtaining and applying this knowledge to new infrastructure projects is essential in order to produce outcomes that are more favorable to local ecosystems and fisheries.« less

Diversifying mechanisms in the on-farm evolution of crop mixtures.

PubMed

Thomas, Mathieu; Thépot, Stéphanie; Galic, Nathalie; Jouanne-Pin, Sophie; Remoué, Carine; Goldringer, Isabelle

2015-06-01

While modern agriculture relies on genetic homogeneity, diversifying practices associated with seed exchange and seed recycling may allow crops to adapt to their environment. This socio-genetic model is an original experimental evolution design referred to as on-farm dynamic management of crop diversity. Investigating such model can help in understanding how evolutionary mechanisms shape crop diversity submitted to diverse agro-environments. We studied a French farmer-led initiative where a mixture of four wheat landraces called 'Mélange de Touselles' (MDT) was created and circulated within a farmers' network. The 15 sampled MDT subpopulations were simultaneously submitted to diverse environments (e.g. altitude, rainfall) and diverse farmers' practices (e.g. field size, sowing and harvesting date). Twenty-one space-time samples of 80 individuals each were genotyped using 17 microsatellite markers and characterized for their heading date in a 'common-garden' experiment. Gene polymorphism was studied using four markers located in earliness genes. An original network-based approach was developed to depict the particular and complex genetic structure of the landraces composing the mixture. Rapid differentiation among populations within the mixture was detected, larger at the phenotypic and gene levels than at the neutral genetic level, indicating potential divergent selection. We identified two interacting selection processes: variation in the mixture component frequencies, and evolution of within-variety diversity, that shaped the standing variability available within the mixture. These results confirmed that diversifying practices and environments maintain genetic diversity and allow for crop evolution in the context of global change. Including concrete measurements of farmers' practices is critical to disentangle crop evolution processes. © 2015 John Wiley & Sons Ltd.

Developing the field of youth organizing and advocacy: what foundations can do.

PubMed

Yee, Sylvia M

2008-01-01

For more than a decade, the Evelyn and Walter Haas, Jr. Fund has seeded many San Francisco Bay Area youth organizing and advocacy programs. Now that the field is maturing, argues the fund's vice president of programs, foundations have a critical programmatic and capacity-building role to play. The author offers analysis and strategies for integrating youth development grant making across foundation interest areas. The programs described illustrate the diversity of youth organizing and advocacy programs that could be supported by funders, whether or not any particular philanthropic institution has a grant-making focus on youth development or youth organizing. The article ends with an in-depth portrait of the self-reported needs of youth organizing and advocacy programs and concrete strategies for foundations seeking to more effectively enable youth organizing and advocacy to play an important role in bringing about a more vibrant, diverse, and effective democratic culture.

Usage of Crushed Concrete Fines in Decorative Concrete

NASA Astrophysics Data System (ADS)

Pilipenko, Anton; Bazhenova, Sofia

2017-10-01

The article is devoted to the questions of usage of crushed concrete fines from concrete scrap for the production of high-quality decorative composite materials based on mixed binder. The main problem in the application of crushed concrete in the manufacture of decorative concrete products is extremely low decorative properties of crushed concrete fines itself, as well as concrete products based on them. However, crushed concrete fines could have a positive impact on the structure of the concrete matrix and could improve the environmental and economic characteristics of the concrete products. Dust fraction of crushed concrete fines contains non-hydrated cement grains, which can be opened in screening process due to the low strength of the contact zone between the hydrated and non-hydrated cement. In addition, the screening process could increase activity of the crushed concrete fines, so it can be used as a fine aggregate and filler for concrete mixes. Previous studies have shown that the effect of the usage of the crushed concrete fines is small and does not allow to obtain concrete products with high strength. However, it is possible to improve the efficiency of the crushed concrete fines as a filler due to the complex of measures prior to mixing. Such measures may include a preliminary mechanochemical activation of the binder (cement binder, iron oxide pigment, silica fume and crushed concrete fines), as well as the usage of polycarboxylate superplasticizers. The development of specific surface area of activated crushed concrete fines ensures strong adhesion between grains of binder and filler during the formation of cement stone matrix. The particle size distribution of the crushed concrete fines could achieve the densest structure of cement stone matrix and improve its resistance to environmental effects. The authors examined the mechanisms of structure of concrete products with crushed concrete fines as a filler. The results of studies of the properties of the crushed concrete fines were provided. It is shown that the admixture of the crushed concrete fines has little effect on the colour characteristics of the decorative concrete products. The preferred options to improve the surfaces of decorative concrete are also proposed.

Removal mechanisms of volatile organic compounds (VOCs) from effluent of common effluent treatment plant (CETP).

PubMed

Padalkar, Ashwini V; Kumar, Rakesh

2018-05-01

This study investigated the occurrence, removal and influence of plant-operating conditions on removal mechanisms of 83 VOCs in different treatment units of a CETP in Mumbai, treating industrial waste on primary and secondary level. A mass balance approach was used to predict VOC removal by volatilization, stripping, weir drop, adsorption, and biodegradation. Results indicate that ∼17% of VOCs were removed by stripping in equalization tank and ∼8% were removed by weir drop in primary clari-flocculator respectively. Biodegradation was the dominant mechanism in aeration tank and was relatively poor for hydrophobic compounds which were more vulnerable to removal by stripping. Stripping rates could be reduced by increasing the active biomass concentration and using fine pore diffusers to reduce the air/effluent ratio. Decrease in Henry's constant and compound concentration can shift the main removal mechanism from stripping to biodegradation. Results also show considerable agreement between measured (71.2%) and predicted (67.1%) total removal, especially in aeration tanks. Equalization tanks (actual, 20.5%, predicted, 16.9%), primary clari-flocculator (actual, 14.2%, predicted, 7.7%), and secondary clarifier units (actual, 29.5%, predicted, 16.8%) showed fairly acceptable differences in measured and predicted removal. The effect of other mechanisms on VOC removal need to be further explored owing to their major contribution to VOC removal. This study is the first attempt in understanding the mechanisms behind the removal of VOCs in each treatment unit, especially equalization tanks and clarifier units, which have been severely underestimated till date. Copyright © 2018 Elsevier Ltd. All rights reserved.

Stratigraphic comparison of six oil fields (WV) producing from Big Injun sandstones

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zou, X.; Donaldson, A.C.

1993-08-01

Clustered within western West Virginia, six oil fields produce from the lower Mississippian Big Injun sandstones, and three more oil fields also supplement this production either from underlying Squaw or Weir sandstones. Shales separate these sandstones that occur stratigraphically between the Sunbury Shale (maximum flooding surface) and pre-Greenbrier unconformity (maximum regressive erosional surface), and represent highstand regressive deposits associated with the postorogenic phase of foreland basin accumulation. Stratigraphic studies show two Big Injun sandstones. The upper sandstone, called the Maccrady Big Injun, is separated from the lower Price/Pocono Big Injun sandstone by red shales. Both Big Injun sandstones consist ofmore » fine-grained river-mouth bars capped by coarse-grained river-channel deposits. Although the six fields are within three adjacent counties, Maccrady Big Injun sandstones of Blue Creek (Kanawha) and Rock Creek (Roane) fields are younger and were deposited by a different fluvial-deltaic system than the Price/Pocono Big Injun sandstones of Granny Creek (Clay), Tariff (Roane) Clendenin (Clay), and Pond Fork (Kanawha) fields. Upper Weir sandstones are thick, narrow north-trending belts underlying Pond Fork and Blue Creek fields, with properties suggesting wave-dominated shoreline deposits. Allocycles spanning separate drainage systems indicate eustasy. Postorogenic flexural adjustments probably explain stacked sandstone belts with superposed paleovalleys of overlying unconformities (pre-Greenbrier, Pottsville), particularly where aligned along or parallel basement structures of Rome trough or West Virginia dome. Initially, differential subsidence or uplift during sedimentation influenced the position, geometry, trend, and distribution patterns of these reservoir sandstone, then influenced their preserved condition during erosion of pre-Greenbrier unconformity.« less

Optimal Decision-making Model of Integrated Water Resources Management - A Case of Hsinchu Water Resources Management

NASA Astrophysics Data System (ADS)

Wang, S. Y.; Ho, C. C.; Chang, L. C.

2017-12-01

The public use water in Hsinchu are mainly supplied from Baoshan Reservoir, Second Baoshan Reservoir, Yongheshan Reservoir and Longen Weir. However, the increasing water demand, caused by development of the Hsinchu Science and Industrial Park, results in supply stable water getting more difficult. For stabilize water supply in Hsinchu, the study applies long-term and short-term plans to fulfill the water shortage. Developing an efficient methodology to define a cost-effective action portfolio is an important task. Hence, the study develops a novel decision model, the Stochastic Programming with Recourse Decision Model (SPRDM), to estimate a cost-effective action portfolio. The first-stage of SPRDM determine the long-term action portfolio and the portfolio accompany recourse information (the probability for water shortage event). The second-stage of SPRDM optimize the cost-effective action portfolio in response to the recourse information. In order to consider the uncertainty of reservoir sediment and demand growth, the study set 9 scenarios comprise optimistic, most likely, and pessimistic reservoir sediment and demand growth. The results show the optimal action portfolio consist of FengTain Lake and Panlon Weir, Hsinchu Desalination Plant, Domestic and Industrial Water long-term plans, and Emergency Backup Well, Irrigation Water Transference, Preliminary Water Rationing, Advanced Water Rationing and Water Transport from Other Districts short-term plans. The minimum expected cost of optimal action portfolio is NT$1.1002 billion. The results can be used as a reference for decision making because the results have considered the uncertainty of varied hydrology, reservoir sediment, and water demand growth.

Salmonid Gamete Preservation in the Snake River Basin, 2001 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Armstrong, Robyn; Kucera, Paul

2002-06-01

Steelhead (Oncorhynchus mykiss) and chinook salmon (Oncorhynchus tshawytscha) populations in the Northwest are decreasing. Genetic diversity is being lost at an alarming rate. Along with reduced population and genetic variability, the loss of biodiversity means a diminished environmental adaptability. The Nez Perce Tribe (Tribe) strives to ensure availability of genetic samples of the existing male salmonid population by establishing and maintaining a germplasm repository. The sampling strategy, initiated in 1992, has been to collect and preserve male salmon and steelhead genetic diversity across the geographic landscape by sampling within the major river subbasins in the Snake River basin, assuming amore » metapopulation structure existed historically. Gamete cryopreservation conserves genetic diversity in a germplasm repository, but is not a recovery action for listed fish species. The Tribe was funded in 2001 by the Bonneville Power Administration (BPA) and the U.S. Fish and Wildlife Service Lower Snake River Compensation Plan (LSRCP) to coordinate gene banking of male gametes from Endangered Species Act (ESA) listed steelhead and spring and summer chinook salmon in the Snake River basin. In 2001, a total of 398 viable chinook salmon semen samples from the Lostine River, Catherine Creek, upper Grande Ronde River, Lookingglass Hatchery (Imnaha River stock), Lake Creek, the South Fork Salmon River weir, Johnson Creek, Big Creek, Capehorn Creek, Marsh Creek, Pahsimeroi Hatchery, and Sawtooth Hatchery (upper Salmon River stock) were cryopreserved. Also, 295 samples of male steelhead gametes from Dworshak Hatchery, Fish Creek, Grande Ronde River, Little Sheep Creek, Pahsimeroi Hatchery and Oxbow Hatchery were also cryopreserved. The Grande Ronde chinook salmon captive broodstock program stores 680 cryopreserved samples at the University of Idaho as a long-term archive, half of the total samples. A total of 3,206 cryopreserved samples from Snake River basin steelhead and spring and summer chinook salmon, from 1992 through 2001, are stored in two independent locations at the University of Idaho (UI) and Washington State University (WSU). Two large freezer tanks are located at each university. Recommendations for future gene banking efforts include the need for establishment of a regional genome resource bank, an emphasis on cryopreserving wild unmarked fish, continued fertility trials, and genetic analysis on all fish represented in the germplasm repository.« less

Properties of concrete containing foamed concrete block waste as fine aggregate replacement

NASA Astrophysics Data System (ADS)

Muthusamy, K.; Budiea, A. M. A.; Zaidan, A. L. F.; Rasid, M. H.; Hazimmah, D. S.

2017-11-01

Environmental degradation due to excessive sand mining dumping at certain places and disposal of foamed concrete block waste from lightweight concrete producing industry are issues that should be resolved for a better and cleaner environment of the community. Thus, the main intention of this study is to investigate the potential of foamed concrete block waste as partial sand replacement in concrete production. The foamed concrete waste (FCW) used in this research that were supplied by a local lightweight concrete producing industry. The workability and compressive strength of concrete containing various percentage of foamed concrete waste as partial sand replacement has been investigated. Prior to the use, the foamed concrete waste were crushed to produce finer particles. Six concrete mixes containing various content of crushed foamed concrete waste that are 0%, 10%, 20%, 30%, 40% and 50% were used in this experimental work. Then the prepared specimens were placed in water curing until the testing age. Compressive strength test and flexural strength tests were conducted at 7, 14 and 28 days. The result shows that integration of crushed foamed concrete waste as partial sand replacement in concrete reduces the mix workability. It is interesting to note that both compressive strength and flexural strength of concrete improves when 30% crushed foamed concrete waste is added as partial sand replacement.

Activation experiment for concrete blocks using thermal neutrons

NASA Astrophysics Data System (ADS)

Okuno, Koichi; Tanaka, Seiichiro

2017-09-01

Activation experiments for ordinary concrete, colemanite-peridotite concrete, B4C-loaded concrete, and limestone concrete are carried out using thermal neutrons. The results reveal that the effective dose for gamma rays from activated nuclides of colemanite-peridotite concrete is lower than that for the other types of concrete. Therefore, colemanite-peridotite concrete is useful for reducing radiation exposure for workers.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berke, N.S.; Dallaire, M.P.; Hicks, M.C.

Corrosion of steel in concrete is studied typically in uncracked concrete. In the field, however, concrete often has cracks that extend to the reinforcing steel. Electrochemical corrosion testing was performed in cracked concrete of two qualities. Results were compared to physical examination of the embedded reinforcement. Corrosion resistance improved significantly as the concrete properties and reinforcement cover approached that recommended in American Concrete Institute 318. Calcium nitrite additions to the concrete reduced corrosion significantly. Results indicated testing in cracked concrete should be performed in concrete representative of that specified in ACl 318.

Research on Durability of Recycled Ceramic Powder Concrete

NASA Astrophysics Data System (ADS)

Chen, M. C.; Fang, W.; Xu, K. C.; Xie, L.

2017-06-01

Ceramic was ground into powder with 325 mesh and used to prepare for concrete. Basic mechanical properties, carbonation and chloride ion penetration of the concrete tests were conducted. In addition, 6-hour electric fluxes of recycled ceramic powder concrete were measured under loading. The results showed that the age strength of ceramics powder concrete is higher than that of the ordinary concrete and the fly ash concrete. The ceramic powder used as admixture would reduce the strength of concrete under no consideration of its impact factor; under consideration of the impact factor for ceramic powder as admixture, the carbonation resistance of ceramic powder concrete was significantly improved, and the 28 day carbonation depth of the ceramic powder concrete was only 31.5% of ordinary concrete. The anti-chloride-permeability of recycled ceramic powder concrete was excellent.

A review on the suitability of rubberized concrete for concrete bridge decks

NASA Astrophysics Data System (ADS)

Syamir Senin, Mohamad; Shahidan, Shahiron; Radziah Abdullah, Siti; Anting Guntor, Nickholas; Syazani Leman, Alif

2017-11-01

Road authorities manage a large population of ageing bridges, a substantial number of which fail to meet the current requirements either due to deterioration and other structural deficiencies or as a result of the escalating demands imposed by increased traffic. This problem is related to the dynamic load from vehicles. This problem can be solved by producing a type of concrete that can reduce the amplitude of oscillation or vibration such as rubberized concrete. Green construction has been a very important aspect in concrete production field in the last decade. One of the most problematic waste materials is scrap tires. The use of scrap tires in civil engineering is increasing by producing rubberized concrete. Rubberized concrete is a type of concrete that is mixed with rubber. The purpose of this review is to justify the suitability of rubberized concrete for concrete bridge decks. Several parameters named physical, chemical and mechanical properties were measured to ensure the suitability of rubberized concrete for concrete bridge decks. Rubberized concrete has similar workability to normal concrete. The rubber reduced the density and compressive strength of the concrete while increased the flexural strength, water absorption and damping ratio. The used of rubber in concrete beyond 20% is not recommended due to decreasing in compressive strength. Rubberized concrete recommended to be used in circumstances where vibration damping was required such as in bridge construction as shock-wave absorber.

Properties of Sulfur Concrete.

DTIC Science & Technology

1979-07-06

36 Thermal Contraction . . . . . . . . . . . 37 Summary of Sulfur Concrete (unmodified) . . . 39 Modified Sulfur Concrete............ 40...Compressive strength of PCPD- modified sulfur concrete 47 20 Functional connection between reaction time and temperature in making DCPD- modified sulfur concrete...39 MODIFIED SULFUR CONCRETE In the previous section it was shown that sulfur concrete exhibits several undesirable properties, such as 1 poor

Characterisation and management of concrete grinding residuals.

PubMed

Kluge, Matt; Gupta, Nautasha; Watts, Ben; Chadik, Paul A; Ferraro, Christopher; Townsend, Timothy G

2018-02-01

Concrete grinding residue is the waste product resulting from the grinding, cutting, and resurfacing of concrete pavement. Potential beneficial applications for concrete grinding residue include use as a soil amendment and as a construction material, including as an additive to Portland cement concrete. Concrete grinding residue exhibits a high pH, and though not hazardous, it is sufficiently elevated that precautions need to be taken around aquatic ecosystems. Best management practices and state regulations focus on reducing the impact on such aquatic environment. Heavy metals are present in concrete grinding residue, but concentrations are of the same magnitude as typically recycled concrete residuals. The chemical composition of concrete grinding residue makes it a useful product for some soil amendment purposes at appropriate land application rates. The presence of unreacted concrete in concrete grinding residue was examined for potential use as partial replacement of cement in new concrete. Testing of Florida concrete grinding residue revealed no dramatic reactivity or improvement in mortar strength.

Effect of insulating concrete forms in concrete compresive strength

NASA Astrophysics Data System (ADS)

Martinez Jerez, Silvio R.

The subject presented in this thesis is the effect of Insulating Concrete Forms (ICF's) on concrete compressive strength. This work seeks to identify if concrete cured in ICF's has an effect in compressive strength due to the thermal insulation provided by the forms. Modern construction is moving to energy efficient buildings and ICF's is becoming more popular in new developments. The thesis used a concrete mixture and a mortar mixture to investigate the effects of ICF's on concrete compressive strength. After the experimentations were performed, it was concluded that the ICF's do affect concrete strength. It was found that the forms increase concrete strength without the need for additional curing water. An increase of 50% in strength at 56 days was obtained. It was concluded that the longer concrete cures inside ICF's, the higher strength it reaches, and that ICF's effect on concrete strength is proportional to volume of concrete.

Evaluation of ilmenite serpentine concrete and ordinary concrete as nuclear reactor shielding

NASA Astrophysics Data System (ADS)

Abulfaraj, Waleed H.; Kamal, Salah M.

1994-07-01

The present study involves adapting a formal decision methodology to the selection of alternative nuclear reactor concretes shielding. Multiattribute utility theory is selected to accommodate decision makers' preferences. Multiattribute utility theory (MAU) is here employed to evaluate two appropriate nuclear reactor shielding concretes in terms of effectiveness to determine the optimal choice in order to meet the radiation protection regulations. These concretes are Ordinary concrete (O.C.) and Ilmenite Serpentile concrete (I.S.C.). These are normal weight concrete and heavy heat resistive concrete, respectively. The effectiveness objective of the nuclear reactor shielding is defined and structured into definite attributes and subattributes to evaluate the best alternative. Factors affecting the decision are dose received by reactor's workers, the material properties as well as cost of concrete shield. A computer program is employed to assist in performing utility analysis. Based upon data, the result shows the superiority of Ordinary concrete over Ilmenite Serpentine concrete.

Mechanical properties of concrete containing recycled concrete aggregate (RCA) and ceramic waste as coarse aggregate replacement

NASA Astrophysics Data System (ADS)

Khalid, Faisal Sheikh; Azmi, Nurul Bazilah; Sumandi, Khairul Azwa Syafiq Mohd; Mazenan, Puteri Natasya

2017-10-01

Many construction and development activities today consume large amounts of concrete. The amount of construction waste is also increasing because of the demolition process. Much of this waste can be recycled to produce new products and increase the sustainability of construction projects. As recyclable construction wastes, concrete and ceramic can replace the natural aggregate in concrete because of their hard and strong physical properties. This research used 25%, 35%, and 45% recycled concrete aggregate (RCA) and ceramic waste as coarse aggregate in producing concrete. Several tests, such as concrete cube compression and splitting tensile tests, were also performed to determine and compare the mechanical properties of the recycled concrete with those of the normal concrete that contains 100% natural aggregate. The concrete containing 35% RCA and 35% ceramic waste showed the best properties compared with the normal concrete.

Experimental study on the strength parameter of Quarry Dust mixed Coconut Shell Concrete adding Coconut Fibre

NASA Astrophysics Data System (ADS)

Matangulu Shrestha, Victor; Anandh, S.; Sindhu Nachiar, S.

2017-07-01

Concrete is a heterogeneous mixture constitute of cement as the main ingredient with a different mix of fine and coarse aggregate. The massive use of conventional concrete has a shortfall in its key ingredients, natural sand and coarse aggregate, due to increased industrialisation and globalisation. To overcome the shortage of material, an alternate material with similar mechanical properties and composition has to be studied, as replacement of conventional concrete. Coconut shell concrete is a prime option as replacement of key ingredients of conventional concrete as coconut is produced in massive quantity in south East Asia. Coconut shell concrete is lightweight concrete and different research is still ongoing concerning about its mix design and composition in the construction industry. Concrete is weak in tension as compared to compression, hence the fibre is used to refrain the crack in the concrete. Coconut fibre is one of many fibres which can be used in concrete. The main aim of this project is to analyse the use of natural by-products in the construction industry, make light weight concrete and eco-friendly construction. This project concerns with the comparison of the mechanical properties of coconut shell concrete and conventional concrete, replacing fine aggregate with quarry dust using coconut fibre. M25 grade of concrete was adopted and testing of concrete was done at the age of 3, 7 and 28 days. In this concrete mix, sand was replaced completely in volumetric measurement by quarry dust. The result was analysed and compared with addition of coconut fibre at varying percentage of 1%, 2%, 3%, 4% and 5%. From the test conducted, coconut shell concrete with quarry dust has the maximum value at 4% of coconut fibre while conventional concrete showed the maximum value at 2% of coconut fibre.

Effective Crack Control of Concrete by Self-Healing of Cementitious Composites Using Synthetic Fiber

PubMed Central

Choi, Heesup; Inoue, Masumi; Kwon, Sukmin; Choi, Hyeonggil; Lim, Myungkwan

2016-01-01

Although concrete is one of the most widely used construction materials, it is characterized by substantially low tensile strength in comparison to its compression strength, and the occurrence of cracks is unavoidable. In addition, cracks progress due to environmental conditions including damage by freezing, neutralization, and salt, etc. Moreover, detrimental damage can occur in concrete structures due to the permeation of deteriorating elements such as Cl− and CO2. Meanwhile, under an environment in which moisture is being supplied and if the width of the crack is small, a phenomenon of self-healing, in which a portion of the crack is filled in due to the rehydration of the cement particles and precipitation of CaCO3, is been confirmed. In this study, cracks in cementitious composite materials are effectively dispersed using synthetic fibers, and for cracks with a width of more than 0.1 mm, a review of the optimal self-healing conditions is conducted along with the review of a diverse range of self-healing performance factors. As a result, it was confirmed that the effective restoration of watertightness through the production of the majority of self-healing products was achieved by CaCO3 and the use of synthetic fibers with polarity, along with the effect of inducing a multiple number of hairline cracks. In addition, it was confirmed that the self-healing conditions of saturated Ca(OH)2 solution, which supplied CO2 micro-bubbles, displayed the most effective self-healing performance in the surface and internal sections of the cracks. PMID:28773372

Toxicity of 4,346 chemicals to larval lampreys and fishes

USGS Publications Warehouse

Applegate, Vernon C.; Howell, John H.; Hall, A.E.; Smith, Manning A.

1957-01-01

The problem of controlling the sea lamprey in the upper Great Lakes has received considerable attention in recent years and requires no review here (Applegate and Moffett. 1955). Electromechanical weirs and traps and electrical barriers have been developed which can be successfully employed to block and/or destroy spawning runs of adult sea lampreys. These devices. when installed in all known $pawning streams. provide an effective method of reducing the numbers of sea lampreys in each lake basin. Initial efforts at control of the lamprey have employed these devices (Applegate. Smith. and Nielsen. 1952; Erkkila. Smith. and McLain. 1956).

National Program for Inspection of Non-Federal Dams. Winsor Dam (MA 00588), Quabbin Spillway (MA 00589), Goodnough Dike (MA 00590), Connecticut River Basin, Ware, Massachusetts. Phase I Inspection Report.

DTIC Science & Technology

1978-09-01

at the en- trance to the channel. Another rockfall occurs along the right side of the channel, about 280 ft. downstream from the channel entrance. The...new level survey on seven settlement observation points at Goodnough Dike, in particular to check the 1973 data at * 27 ,nn lnmnnnm u u ~ l I • lI gI ...Spillway weir masonry to maintain the structure in good condition. 3. Periodically remove brush, saplings and rockfalls from the I spiliway discharge

Acoustic Telemetry Evaluation of Juvenile Salmonid Passage and Survival at John Day Dam with Emphasis on the Prototype Surface Flow Outlet, 2008

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weiland, Mark A.; Ploskey, Gene R.; Hughes, James S.

The main purpose of the study was to evaluate the performance of Top Spill Weirs installed at two spillbays at John Day Dam and evaluate the effectiveness of these surface flow outlets at attracting juvenile salmon away from the powerhouse and reducing turbine passage. The Juvenile Salmonid Acoustic Telemetry System (JSATS) was used to estimate survival of juvenile salmonids passing the dam and also for calculating performance metrics used to evaluate the efficiency and effectiveness of the dam at passing juvenile salmonids.

Silver Creek: A Study of Stream Velocities and Erosion along the Ohio River near Clarksville, Indiana; McAlpine Lock and Dam Numerical Model

DTIC Science & Technology

2018-04-12

split between the upper and lower gates, the tainter gate outflow can cause flow circulations or eddies to form , which requires the use of a multi...determined to not erode were assigned a bed layer thickness of zero. This included the stone weir, fossil beds, non-erodible vegetation, and upstream...606.7 Chute 0.1 606 L 0.4 Erodible Small Vegetation 606.7 Chute 0.1 606 L 0.4 Fossil Bed NA 0 NA 0 Non Erodible Small Vegetation NA 0 NA 0 Non

A land mobile satellite data system

NASA Technical Reports Server (NTRS)

Kent, John D. B.

1990-01-01

The Telesat Mobile Incorporated (TMI) Mobile Data System (MDS) was developed to apply satellite technology to the transportation industry's requirement for a fleet management system. It will provide two-way messaging and automatic position reporting capabilities between dispatch centers and customers' fleets of trucks. The design was based on the Inmarsat L-Band space segment with system link parameters and margins adjusted to meet the land mobile satellite channel characteristics. The system interfaces with the Teleglobe Des Laurentides earth station at Weir, Quebec. The signaling protocols were derived from the Inmarsat Standard C packet signalling system with unique trucking requirements incorporated where necessary.

Snake River Sockeye Salmon Captive Broodstock Program; Hatchery Element, 2004 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, Dan J.; Heindel, Jeff A.; Redding, Jeremy

2006-05-01

On November 20, 1991, the National Marine Fisheries Service listed Snake River sockeye salmon Oncorhynchus nerka as endangered under the Endangered Species Act of 1973. In 1991, the Idaho Department of Fish and Game, the Shoshone-Bannock Tribes, and the National Marine Fisheries Service initiated efforts to conserve and rebuild populations in Idaho. Initial steps to recover sockeye salmon included the establishment of a captive broodstock program at the Idaho Department of Fish and Game Eagle Fish Hatchery. Sockeye salmon broodstock and culture responsibilities are shared with the National Oceanic and Atmospheric Administration at two locations adjacent to Puget Sound inmore » Washington State. Activities conducted by the Shoshone-Bannock Tribes and the National Oceanic and Atmospheric Administration are reported under separate cover. Idaho Department of Fish and Game monitoring and evaluation activities of captive broodstock program fish releases (annual report to the Bonneville Power Administration for the research element of the program) are also reported separately. Captive broodstock program activities conducted between January 1, 2004 and December 31, 2004 for the hatchery element of the program are presented in this report. In 2004, twenty-seven anadromous sockeye salmon returned to the Sawtooth Valley. Traps on Redfish Lake Creek and the upper Salmon River at the Sawtooth Fish Hatchery intercepted one and four adults, respectively. Additionally, one adult sockeye salmon was collected at the East Fork Salmon River weir, 18 were seined from below the Sawtooth Fish Hatchery weir, one adult sockeye salmon was observed below the Sawtooth Fish Hatchery weir but not captured, and two adult sockeye salmon were observed in Little Redfish Lake but not captured. Fish were captured/collected between July 24 and September 14, 2004. The captured/collected adult sockeye salmon (12 females and 12 males) originated from a variety of release strategies and were transferred to Eagle Fish Hatchery on September 14, 2004 and later incorporated into hatchery spawn matrices. Nine anadromous females, 102 captive females from brood year 2001, and one captive female from brood year 2000 broodstock groups were spawned at the Eagle Hatchery in 2004. Spawn pairings produced approximately 140,823 eyed-eggs with egg survival to eyed stage of development averaging 72.8%. Eyed-eggs (49,134), presmolts (130,716), smolts (96), and adults (241) were planted or released into Sawtooth Valley waters in 2004. Reintroduction strategies involved releases to Redfish Lake, Alturas Lake, and Pettit Lake. During this reporting period, five broodstocks and five unique production groups were in culture at Idaho Department of Fish and Game (Eagle Fish Hatchery and Sawtooth Fish Hatchery) and Oregon Department of Fish and Wildlife (Oxbow Fish Hatchery) facilities. Two of the five broodstocks were incorporated into the 2004 spawning design.« less

Physical and mechanical properties of self-compacting concrete containing superplasticizer and metakaolin

NASA Astrophysics Data System (ADS)

Shahidan, Shahiron; Tayeh, Bassam A.; Jamaludin, A. A.; Bahari, N. A. A. S.; Mohd, S. S.; Zuki Ali, N.; Khalid, F. S.

2017-11-01

The development of concrete technology shows a variety of admixtures in concrete to produce special concrete. This includes the production of self-compacting concrete which is able to fill up all spaces, take formwork shapes and pass through congested reinforcement bars without vibrating or needing any external energy. In this study, the main objective is to compare the physical and mechanical properties of self-compacting concrete containing metakaolin with normal concrete. Four types of samples were produced to study the effect of metakaolin towards the physical and mechanical properties of self-compacting concrete where 0%, 5%, 10% and 15% of metakaolin were used as cement replacement. The physical properties were investigated using slump test for normal concrete and slump flow test for self-compacting concrete. The mechanical properties were tested for compressive strength and tensile strength. The findings of this study show that the inclusion of metakaolin as cement replacement can increase both compressive and tensile strength compared to normal concrete. The highest compressive strength was found in self-compacting concrete with 15% metakaolin replacement at 53.3 MPa while self-compacting concrete with 10% metakaolin replacement showed the highest tensile strength at 3.6 MPa. On top of that, the finishing or concrete surface of both cube and cylinder samples made of self-compacting concrete produced a smooth surface with the appearance of less honeycombs compared to normal concrete.

Mechanical properties of concrete containing a high volume of tire-rubber particles.

PubMed

Khaloo, Ali R; Dehestani, M; Rahmatabadi, P

2008-12-01

Due to the increasingly serious environmental problems presented by waste tires, the feasibility of using elastic and flexible tire-rubber particles as aggregate in concrete is investigated in this study. Tire-rubber particles composed of tire chips, crumb rubber, and a combination of tire chips and crumb rubber, were used to replace mineral aggregates in concrete. These particles were used to replace 12.5%, 25%, 37.5%, and 50% of the total mineral aggregate's volume in concrete. Cylindrical shape concrete specimens 15 cm in diameter and 30 cm in height were fabricated and cured. The fresh rubberized concrete exhibited lower unit weight and acceptable workability compared to plain concrete. The results of a uniaxial compressive strain control test conducted on hardened concrete specimens indicate large reductions in the strength and tangential modulus of elasticity. A significant decrease in the brittle behavior of concrete with increasing rubber content is also demonstrated using nonlinearity indices. The maximum toughness index, indicating the post failure strength of concrete, occurs in concretes with 25% rubber content. Unlike plain concrete, the failure state in rubberized concrete occurs gently and uniformly, and does not cause any separation in the specimen. Crack width and its propagation velocity in rubberized concrete are lower than those of plain concrete. Ultrasonic analysis reveals large reductions in the ultrasonic modulus and high sound absorption for tire-rubber concrete.

An Experimental Study on Shrinkage Strains of Normal-and High-Strength Concrete-Filled Frp Tubes

NASA Astrophysics Data System (ADS)

Vincent, Thomas; Ozbakkaloglu, Togay

2017-09-01

It is now well established that concrete-filled fiber reinforced polymer (FRP) tubes (CFFTs) are an attractive construction technique for new columns, however studies examining concrete shrinkage in CFFTs remain limited. Concrete shrinkage may pose a concern for CFFTs, as in these members the curing of concrete takes place inside the FRP tube. This paper reports the findings from an experimental study on concrete shrinkage strain measurements for CFFTs manufactured with normal- and high-strength concrete (NSC and HSC). A total of 6 aramid FRP (AFRP)-confined concrete specimens with circular cross-sections were manufactured, with 3 specimens each manufactured using NSC and HSC. The specimens were instrumented with surface and embedded strain gauges to monitor shrinkage development of exposed concrete and concrete sealed inside the CFFTs, respectively. All specimens were cylinders with a 152 mm diameter and 305 mm height, and their unconfined concrete strengths were 44.8 or 83.2 MPa. Analysis of the shrinkage measurements from concrete sealed inside the CFFTs revealed that embedment depth and concrete compressive strength only had minor influences on recorded shrinkage strains. However, an analysis of shrinkage measurements from the exposed concrete surface revealed that higher amounts of shrinkage can occur in HSC. Finally, it was observed that shrinkage strains are significantly higher for concrete exposed at the surface compared to concrete sealed inside the CFFTs.

Maximum heat of mass concrete - phase 2 [summary].

DOT National Transportation Integrated Search

2016-12-01

Concrete hardens through a chemical reaction that produces heat and expansion, followed by contraction as the concrete cools. Concrete near the edge of a pour cools faster and shrinks earlier than concrete further from the edge. Most concrete pours a...

ConcreteWorks v3 training/user manual (P1) : ConcreteWorks software (P2).

DOT National Transportation Integrated Search

2017-04-01

ConcreteWorks is designed to be a user-friendly software package that can help concrete : professionals optimize concrete mixture proportioning, perform a concrete thermal analysis, and : increase the chloride diffusion service life. The software pac...

The effect of steel slag as a coarse aggregate and Sinabung volcanic ash a filler on high strength concrete

NASA Astrophysics Data System (ADS)

Karolina, R.; Putra, A. L. A.

2018-02-01

The Development of concrete technology is continues to grow. The requisite for efficient constructions that are often viewed in terms of concrete mechanical behavior, application on the field, and cost estimation of implementation increasingly require engineers to optimize construction materials, especially for concrete materials. Various types of concrete have now been developed according to their needs, such as high strength concrete. On high strength concrete design, it is necessary to consider several factors that will affect the reach of the quality strength, Those are cement, water cement ratio (w/c), aggregates, and proper admixture. In the use of natural mineral, it is important for an engineer to keep an eye on the natural conditions that have been explored. So the selection of aggregates as possible is a material that is not causing nature destruction. On this experiment the use of steel slag from PT.Growth Sumatra Industry as a substitute of coarse and fine aggregate, and volcanic ash of mount Sinabung as microsilka in concrete mixture substituted to create high strength concrete that is harmless for the environment. The use of mount sinabung volcanic ash as microsilika coupled with the use of Master Glenium Sky 8614 superplasticizer. This experiment intend to compare high strength concrete based slag steel as the main constituent aggregates and high strength concrete with a conventional mixture. The research result for 28 days old concrete shows that conventional concrete compressive strength is 67.567 MPa, slag concrete 75.958 Mpa, conventional tensile strength 5.435 Mpa while slag concrete 5.053 Mpa, conventional concrete bending strength 44064.96 kgcm while concrete slag 51473.94 kgcm and modulus of conventional concrete fracture 124.978 kg / cm2 while slag concrete 145.956 kg / cm2. Both concrete slump values shows similar results due to the use of superplasticizer.

Investigation on Flexure Test of Composite Beam of Repair Materials and Substrate Concrete for Durable Repair

NASA Astrophysics Data System (ADS)

Pattnaik, Rashmi R.; Rangaraju, Prasada Rao

2014-12-01

An experimental study was conducted on composite beam of repair materials and substrate concrete to investigate the failures of concrete repair due to differences in strength of repair materials and substrate concrete. In this investigation the flexural strength, load-deflection curves and failure patterns of the composite beam specimens are studied for the durability of the concrete repair. Flexure test was conducted to simulate tensile stress in the concrete repair material. Compressive strength and split tensile strength of the repair materials and substrate concrete are investigated to aid in the analysis of the concrete repair. It was observed that the repair materials of higher compressive strength than the substrate concrete are causing an incompatible failure in the concrete repair.

A Study on the Reuse of Plastic Concrete Using Extended Set-Retarding Admixtures.

PubMed

Lobo, Colin; Guthrie, William F; Kacker, Raghu

1995-01-01

The disposal of ready mixed concrete truck wash water and returned plastic concrete is a growing concern for the ready mixed concrete industry. Recently, extended set-retarding admixtures, or stabilizers, which slow or stop the hydration of portland cement have been introduced to the market. Treating truck wash-water or returned plastic concrete with stabilizing admixtures delays its setting and hardening, thereby facilitating the incorporation of these typically wasted materials in subsequent concrete batches. In a statistically designed experiment, the properties of blended concrete containing stabilized plastic concrete were evaluated. The variables in the study included (1) concrete age when stabilized, (2) stabilizer dosage, (3) holding period of the treated (stabilized) concrete prior to blending with fresh ingredients, and (4) amount of treated concrete in the blended batch. The setting time, strength, and drying shrinkage of the blended concretes were evaluated. For the conditions tested, batching 5 % treated concrete with fresh material did not have a significant effect on the setting time, strength, or drying shrinkage of the resulting blended concrete. Batching 50 % treated concrete with fresh materials had a significant effect on the setting characteristics of the blended cocnrete, which in turn affected the water demand to maintain slump. The data suggests that for a known set of conditions, the stabilizer dosage can be optimized within a relatively narrow range to produce desired setting characteristics. The strength and drying shrinkage of the blended concretes were essentially a function of the water content at different sampling ages and the relationship followed the general trend of control concrete.

A Study on the Reuse of Plastic Concrete Using Extended Set-Retarding Admixtures

PubMed Central

Lobo, Colin; Guthrie, William F.; Kacker, Raghu

1995-01-01

The disposal of ready mixed concrete truck wash water and returned plastic concrete is a growing concern for the ready mixed concrete industry. Recently, extended set-retarding admixtures, or stabilizers, which slow or stop the hydration of portland cement have been introduced to the market. Treating truck wash-water or returned plastic concrete with stabilizing admixtures delays its setting and hardening, thereby facilitating the incorporation of these typically wasted materials in subsequent concrete batches. In a statistically designed experiment, the properties of blended concrete containing stabilized plastic concrete were evaluated. The variables in the study included (1) concrete age when stabilized, (2) stabilizer dosage, (3) holding period of the treated (stabilized) concrete prior to blending with fresh ingredients, and (4) amount of treated concrete in the blended batch. The setting time, strength, and drying shrinkage of the blended concretes were evaluated. For the conditions tested, batching 5 % treated concrete with fresh material did not have a significant effect on the setting time, strength, or drying shrinkage of the resulting blended concrete. Batching 50 % treated concrete with fresh materials had a significant effect on the setting characteristics of the blended cocnrete, which in turn affected the water demand to maintain slump. The data suggests that for a known set of conditions, the stabilizer dosage can be optimized within a relatively narrow range to produce desired setting characteristics. The strength and drying shrinkage of the blended concretes were essentially a function of the water content at different sampling ages and the relationship followed the general trend of control concrete. PMID:29151762

The influence of concrete mixture’s rheological properties on the quality of formed concrete surfaces

NASA Astrophysics Data System (ADS)

Daukšys, M.; Klovas, A.; Venčkauskas, L.

2017-09-01

This study mainly lays emphasis on examining the influence of concrete mixture rheological properties on the quality of formed concrete surfaces. Mixture’s fine aggregate change was taken into the consideration. Over the course of concrete mixture preparation the inner ratio of fine aggregate (sand: fraction of 0/1 and 0/4) was changed. The idea was to increase the quantity of fine particles in the total aggregate’s volume therefore quantity of sand (fraction 0/1) was increased. Six different concrete mixture’s compositions were designed as well as three specimens (concrete piles of 1m2 surface area) were casted. Rheological properties of concrete mixtures were analytically obtained and the quality of formed concrete surfaces was evaluated using image analysis method “BetonGUY 2.0”. As can be obtained from the dependence between concrete mixture rheological properties and its formed surface quality, the increase of concrete mixture’s yield stress and plastic viscosity reduces the quantity of air pores on formed concrete surfaces.

Workability enhancement of geopolymer concrete through the use of retarder

NASA Astrophysics Data System (ADS)

Umniati, B. Sri; Risdanareni, Puput; Zein, Fahmi Tarmizi Zulfikar

2017-09-01

Geopolymer concrete is a type of concrete manufactured without the addition of cement. In geopolymer concrete, along with an activator, cement as the concrete binder can be replaced by the fly ash. This will reduce global demand on cement, and therefore will reduce CO2 emission due to cement production. Thus, geopolymer concrete is commonly known as an eco-friendly concrete. Geopolymer concrete also offers a solution concerning with the utilization of the fly ash waste. However, despite of its environmental advantages, geopolymer concrete has a drawback, namelygeopolymer concrete set quickly, thus reducing its workability. This research aimed to increase the workability of geopolymer concrete by using retarder admixture (Plastocrete RT6 Plus). Retarder used varies within 0.2%, 0.4% and 0.6% of fly ash mass. As a control, geopolymer concrete without retarder (0%) were also made. Activator used in this research was Na2SiO3 mixed with NaOH 10 M solution, with ratio of 1:5. The results showed an optimum composition of geopolymer concrete with 0.6% retarder, where initial setting time occured after 6.75 hours, and the final setting time reached after 9.5 hours. Moreover, the slump of the geopolymer concrete was 8.8 cm, and the slump flow was 24 cm. The compressive strength of the geopolymer concrete at 28 days was 47.21 MPa. The experiment showed that the more retarder added, the setting time of the geopolymer concrete will be increased, thus increasing its workability.

Testing of concrete by laser ablation

DOEpatents

Flesher, Dann J.; Becker, David L.; Beem, William L.; Berry, Tommy C.; Cannon, N. Scott

1997-01-01

A method of testing concrete in a structure in situ, by: directing a succession of pulses of laser radiation at a point on the structure so that each pulse effects removal of a quantity of concrete and transfers energy to the concrete; detecting a characteristic of energy which has been transferred to the concrete; determining, separately from the detecting step, the total quantity of concrete removed by the succession of pulses; and calculating a property of the concrete on the basis of the detected energy characteristic and the determined total quantity of concrete removed.

Prediction model for carbonation depth of concrete subjected to freezing-thawing cycles

NASA Astrophysics Data System (ADS)

Xiao, Qian Hui; Li, Qiang; Guan, Xiao; Xian Zou, Ying

2018-03-01

Through the indoor simulation test of the concrete durability under the coupling effect of freezing-thawing and carbonation, the variation regularity of concrete neutralization depth under freezing-thawing and carbonation was obtained. Based on concrete carbonation mechanism, the relationship between the air diffusion coefficient and porosity in concrete was analyzed and the calculation method of porosity in Portland cement concrete and fly ash cement concrete was investigated, considering the influence of the freezing-thawing damage on the concrete diffusion coefficient. Finally, a prediction model of carbonation depth of concrete under freezing-thawing circumstance was established. The results obtained using this prediction model agreed well with the experimental test results, and provided a theoretical reference and basis for the concrete durability analysis under multi-factor environments.

Penetration analysis of projectile with inclined concrete target

NASA Astrophysics Data System (ADS)

Kim, S. B.; Kim, H. W.; Yoo, Y. H.

2015-09-01

This paper presents numerical analysis result of projectile penetration with concrete target. We applied dynamic material properties of 4340 steels, aluminium and explosive for projectile body. Dynamic material properties were measured with static tensile testing machine and Hopkinson pressure bar tests. Moreover, we used three concrete damage models included in LS-DYNA 3D, such as SOIL_CONCRETE, CSCM (cap model with smooth interaction) and CONCRETE_DAMAGE (K&C concrete) models. Strain rate effect for concrete material is important to predict the fracture deformation and shape of concrete, and penetration depth for projectiles. CONCRETE_DAMAGE model with strain rate effect also applied to penetration analysis. Analysis result with CSCM model shows good agreement with penetration experimental data. The projectile trace and fracture shapes of concrete target were compared with experimental data.

Experimental investigation on temperature distribution of foamed concrete filled steel tube column under standard fire

NASA Astrophysics Data System (ADS)

Kado, B.; Mohammad, S.; Lee, Y. H.; Shek, P. N.; Kadir, M. A. A.

2018-04-01

Standard fire test was carried out on 3 hollow steel tube and 6 foamed concrete filled steel tube columns. Temperature distribution on the columns was investigated. 1500 kg/m3 and 1800 kg/m3 foamed concrete density at 15%, 20% and 25% load level are the parameters considered. The columns investigated were 2400 mm long, 139.7 mm outer diameter and 6 mm steel tube thickness. The result shows that foamed concrete filled steel tube columns has the highest fire resistance of 43 minutes at 15% load level and low critical temperature of 671 ºC at 25% load level using 1500 kg/m3 foamed concrete density. Fire resistance of foamed concrete filled column increases with lower foamed concrete strength. Foamed concrete can be used to provide more fire resistance to hollow steel column or to replace normal weight concrete in concrete filled columns. Since filling hollow steel with foamed concrete produce column with high fire resistance than unfilled hollow steel column. Therefore normal weight concrete can be substituted with foamed concrete in concrete filled column, it will reduces the self-weight of the structure because of its light weight at the same time providing the desired fire resistance.

Effects of Medium Temperature and Industrial By-Products on the Key Hardened Properties of High Performance Concrete.

PubMed

Safiuddin, Md; Raman, Sudharshan N; Zain, Muhammad Fauzi Mohd

2015-12-10

The aim of the work reported in this article was to investigate the effects of medium temperature and industrial by-products on the key hardened properties of high performance concrete. Four concrete mixes were prepared based on a water-to-binder ratio of 0.35. Two industrial by-products, silica fume and Class F fly ash, were used separately and together with normal portland cement to produce three concrete mixes in addition to the control mix. The properties of both fresh and hardened concretes were examined in the laboratory. The freshly mixed concrete mixes were tested for slump, slump flow, and V-funnel flow. The hardened concretes were tested for compressive strength and dynamic modulus of elasticity after exposing to 20, 35 and 50 °C. In addition, the initial surface absorption and the rate of moisture movement into the concretes were determined at 20 °C. The performance of the concretes in the fresh state was excellent due to their superior deformability and good segregation resistance. In their hardened state, the highest levels of compressive strength and dynamic modulus of elasticity were produced by silica fume concrete. In addition, silica fume concrete showed the lowest level of initial surface absorption and the lowest rate of moisture movement into the interior of concrete. In comparison, the compressive strength, dynamic modulus of elasticity, initial surface absorption, and moisture movement rate of silica fume-fly ash concrete were close to those of silica fume concrete. Moreover, all concretes provided relatively low compressive strength and dynamic modulus of elasticity when they were exposed to 50 °C. However, the effect of increased temperature was less detrimental for silica fume and silica fume-fly ash concretes in comparison with the control concrete.

Effects of Medium Temperature and Industrial By-Products on the Key Hardened Properties of High Performance Concrete

PubMed Central

Safiuddin, Md.; Raman, Sudharshan N.; Zain, Muhammad Fauzi Mohd.

2015-01-01

The aim of the work reported in this article was to investigate the effects of medium temperature and industrial by-products on the key hardened properties of high performance concrete. Four concrete mixes were prepared based on a water-to-binder ratio of 0.35. Two industrial by-products, silica fume and Class F fly ash, were used separately and together with normal portland cement to produce three concrete mixes in addition to the control mix. The properties of both fresh and hardened concretes were examined in the laboratory. The freshly mixed concrete mixes were tested for slump, slump flow, and V-funnel flow. The hardened concretes were tested for compressive strength and dynamic modulus of elasticity after exposing to 20, 35 and 50 °C. In addition, the initial surface absorption and the rate of moisture movement into the concretes were determined at 20 °C. The performance of the concretes in the fresh state was excellent due to their superior deformability and good segregation resistance. In their hardened state, the highest levels of compressive strength and dynamic modulus of elasticity were produced by silica fume concrete. In addition, silica fume concrete showed the lowest level of initial surface absorption and the lowest rate of moisture movement into the interior of concrete. In comparison, the compressive strength, dynamic modulus of elasticity, initial surface absorption, and moisture movement rate of silica fume-fly ash concrete were close to those of silica fume concrete. Moreover, all concretes provided relatively low compressive strength and dynamic modulus of elasticity when they were exposed to 50 °C. However, the effect of increased temperature was less detrimental for silica fume and silica fume-fly ash concretes in comparison with the control concrete. PMID:28793732

Probabilistic design of fibre concrete structures

NASA Astrophysics Data System (ADS)

Pukl, R.; Novák, D.; Sajdlová, T.; Lehký, D.; Červenka, J.; Červenka, V.

2017-09-01

Advanced computer simulation is recently well-established methodology for evaluation of resistance of concrete engineering structures. The nonlinear finite element analysis enables to realistically predict structural damage, peak load, failure, post-peak response, development of cracks in concrete, yielding of reinforcement, concrete crushing or shear failure. The nonlinear material models can cover various types of concrete and reinforced concrete: ordinary concrete, plain or reinforced, without or with prestressing, fibre concrete, (ultra) high performance concrete, lightweight concrete, etc. Advanced material models taking into account fibre concrete properties such as shape of tensile softening branch, high toughness and ductility are described in the paper. Since the variability of the fibre concrete material properties is rather high, the probabilistic analysis seems to be the most appropriate format for structural design and evaluation of structural performance, reliability and safety. The presented combination of the nonlinear analysis with advanced probabilistic methods allows evaluation of structural safety characterized by failure probability or by reliability index respectively. Authors offer a methodology and computer tools for realistic safety assessment of concrete structures; the utilized approach is based on randomization of the nonlinear finite element analysis of the structural model. Uncertainty of the material properties or their randomness obtained from material tests are accounted in the random distribution. Furthermore, degradation of the reinforced concrete materials such as carbonation of concrete, corrosion of reinforcement, etc. can be accounted in order to analyze life-cycle structural performance and to enable prediction of the structural reliability and safety in time development. The results can serve as a rational basis for design of fibre concrete engineering structures based on advanced nonlinear computer analysis. The presented methodology is illustrated on results from two probabilistic studies with different types of concrete structures related to practical applications and made from various materials (with the parameters obtained from real material tests).

Pushover analysis of reinforced concrete frames considering shear failure at beam-column joints

NASA Astrophysics Data System (ADS)

Sung, Y. C.; Lin, T. K.; Hsiao, C. C.; Lai, M. C.

2013-09-01

Since most current seismic capacity evaluations of reinforced concrete (RC) frame structures are implemented by either static pushover analysis (PA) or dynamic time history analysis, with diverse settings of the plastic hinges (PHs) on such main structural components as columns, beams and walls, the complex behavior of shear failure at beam-column joints (BCJs) during major earthquakes is commonly neglected. This study proposes new nonlinear PA procedures that consider shear failure at BCJs and seek to assess the actual damage to RC structures. Based on the specifications of FEMA-356, a simplified joint model composed of two nonlinear cross struts placed diagonally over the location of the plastic hinge is established, allowing a sophisticated PA to be performed. To verify the validity of this method, the analytical results for the capacity curves and the failure mechanism derived from three different full-size RC frames are compared with the experimental measurements. By considering shear failure at BCJs, the proposed nonlinear analytical procedures can be used to estimate the structural behavior of RC frames, including seismic capacity and the progressive failure sequence of joints, in a precise and effective manner.

Influence of processing factors over concrete strength.

NASA Astrophysics Data System (ADS)

Kara, K. A.; Dolzhenko, A. V.; Zharikov, I. S.

2018-03-01

Construction of facilities of cast in-situ reinforced concrete poses additional requirements to quality of material, peculiarities of the construction process may sometimes lead to appearance of lamination planes and inhomogeneity of concrete, which reduce strength of the material and structure as a whole. Technology compliance while working with cast in-situ concrete has a significant impact onto the concrete strength. Such process factors as concrete curing, vibration and compaction of the concrete mixture, temperature treatment, etc., when they are countered or inadequately followed lead to a significant reduction in concrete strength. Here, the authors experimentally quantitatively determine the loss of strength in in-situ cast concrete structures due to inadequate following of process requirements, in comparison with full compliance.

Long-Term, Deep Ocean Test of Concrete Spherical Structures - Results after 13 Years.

DTIC Science & Technology

1985-07-01

corrosion of reinforcing steel are problems, even though the concrete becomes saturated with seawater. Uncoated concrete has a very low rate of permeation... concrete matrix nor corrosion of reinforcing steel are problems, even though the concrete becomes saturated with seawater. Uncoated concrete I has a...which concrete protects the steel against corrosion in the deep ocean environ- ment. The ocean depth range for the spheres corresponds to predicled

Retrieval of concrete words involves more contextual information than abstract words: multiple components for the concreteness effect.

PubMed

Xiao, Xin; Zhao, Di; Zhang, Qin; Guo, Chun-yan

2012-03-01

The current study used the directed forgetting paradigm in implicit and explicit memory to investigate the concreteness effect. Event-related potentials (ERPs) were recorded to explore the neural basis of this phenomenon. The behavioral results showed a clear concreteness effect in both implicit and explicit memory tests; participants responded significantly faster to concrete words than to abstract words. The ERP results revealed a concreteness effect (N400) in both the encoding and retrieval phases. In addition, behavioral and ERP results showed an interaction between word concreteness and memory instruction (to-be-forgotten vs. to-be-remembered) in the late epoch of the explicit retrieval phase, revealing a significant concreteness effect only under the to-be-remembered instruction condition. This concreteness effect was realized as an increased P600-like component in response to concrete words relative to abstract words, likely reflecting retrieval of contextual details. The time course of the concreteness effect suggests advantages of concrete words over abstract words due to greater contextual information. Copyright © 2011 Elsevier Inc. All rights reserved.

Steelhead Supplementation in Idaho Rivers, 2000 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Byrne, Alan

In 2000, we continued our assessment of the Sawtooth Hatchery steelhead stock to reestablish natural populations in Beaver and Frenchman creeks in the upper Salmon River. We stocked both streams with 15 pair of hatchery adults and estimated the potential smolt production from the 1999 outplant. I estimated that about nine smolts per female could be produced in both streams from the 1999 outplant. The smolt-to-adult return would need to exceed 20% to return two adults at this level of production. In the Red River drainage, we stocked Dworshak hatchery stock fingerlings and smolts, from 1993 to 1999, to assessmore » which life-stage produces more progeny when the adults return to spawn. In 2000, we operated the Red River weir to trap adults that returned from these stockings, but none were caught from either group. We continued to monitor wild steelhead populations in the Lochsa and Selway river drainages. We estimated that 26 wild adult steelhead returned to Fish Creek. This is the lowest adult escapement we have documented (when the weir was intact all spring) since we began monitoring Fish Creek in 1992. I estimated that nearly 25,000 juvenile steelhead migrated out of Fish Creek this year. Juvenile steelhead densities in Lochsa and Selway tributaries were similar to those observed in 1999. In 2000, we obtained funding for a DNA analysis to assess Idaho's steelhead stock structure. We collected fin samples from wild steelhead in 70 streams of the Clearwater, Snake, and Salmon River drainages and from our five hatchery stocks. The DNA analysis was subcontracted to Dr. Jennifer Nielsen, Alaska Biological Science Center, Anchorage, and will be completed in 2001.« less

Dynamics of dissolved organic matter in riverine sediments affected by weir impoundments: Production, benthic flux, and environmental implications.

PubMed

Chen, Meilian; Kim, Sung-Han; Jung, Heon-Jae; Hyun, Jung-Ho; Choi, Jung Hyun; Lee, Hyo-Jin; Huh, In-Ae; Hur, Jin

2017-09-15

In order to understand the characteristics and dynamics of dissolved organic matter (DOM) in the sediment of rivers affected by impoundments, we examined the vertical profiles and the benthic fluxes of DOM in four different core sediments located at upstream sites of weirs in major rivers of South Korea. In three out of four sites, exponential accumulation of dissolved organic carbon (DOC) with depth was observed with the signature of seasonal variability. Except for the site displaying a below-detection limit of Fe(II), the general accumulation trends of DOC with depth was concurrent with the increases of Fe(II) and NH 4 + and the decrease of PO 4 3- , signifying a close linkage of the DOM dynamics with anaerobic respiration via iron reduction, an important early diagenesis pathway. The estimated benthic fluxes from the cores revealed that the sediments likely serve as DOC, chromophoric DOM (CDOM), and fluorescent DOM (FDOM) sources to the overlying water. The benthic effluxes based on DOC were comparable to the ranges previously reported in lake and coastal areas, and those of CDOM and FDOM showed even higher levels. These findings imply that impoundment-affected river systems would change the DOM composition of the overlying water, ultimately influencing the subsequent water treatment processes such as disinfection byproducts production and membrane fouling. A simple mass balance model indicated that the impoundment-affected river sediments may operate as a net carbon sink in the environments due to a greater extent of sedimentation compared to the estimated benthic efflux and sediment biological respiration. Copyright © 2017 Elsevier Ltd. All rights reserved.

PONDCALC - A Tool to Estimate Discharge from the Alviso Salt Ponds, California

USGS Publications Warehouse

Shellenbarger, Gregory; Schoellhamer, David H.; Lionberger, Megan A.

2007-01-01

Former commercial salt ponds in Alviso, California, now are operated by the U.S. Fish and Wildlife Service (USFWS) to provide habitat for birds. The USFWS has modified the operation of the ponds to prevent exceedingly high salinity. Ponds that were formerly hydraulically isolated from South San Francisco Bay and adjacent sloughs now are managed as flow-through ponds, and some are allowed to discharge to the Bay and sloughs. This discharge is allowed under a permit issued by the Regional Water Quality Control Board. As a requirement of the permit, the USFWS must estimate the amount of discharge from each discharge pond for the period May through November of each year. To facilitate the accurate estimation of pond discharge, a calculation methodology (hereafter referred to as 'calculator' or PONDCALC) for the discharging Alviso ponds has been developed as a Microsoft Excel file and is presented in this report. The presence of flap gates on one end of the discharge culverts, which allow only outflow from a pond, complicates the hydraulic analysis of flow through the culverts. The equation typically used for culvert flow contains an energy loss coefficient that had to be determined empirically using measured water discharge and head at the discharge structure of one of the ponds. A standard weir-flow equation is included in PONDCALC for discharge calculation in the ponds having weir box structures in addition to culverts. The resulting methodology is applicable only to the five Alviso ponds (A2W, A3W, A7, A14, and A16) that discharge to South San Francisco Bay or adjacent sloughs under the management practices for 2005.

Oncorhynchus nerka population monitoring in the Sawtooth Valley Lakes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teuscher, D.M.; Taki, D.; Ariwite, K.

1996-05-01

Critical habitat for endangered Snake River sockeye salmon includes five rearing lakes located in the Sawtooth Valley of central Idaho. Most of the lakes contain either introduced or endemic kokanee populations. Snake River sockeye occur naturally in Redfish Lake, and are being stocked in Redfish and Pettit Lakes. Because kokanee compete with sockeye for limited food resources, understanding population characteristics of both species such as spawn timing, egg-to-fry survival, distribution and abundance are important components of sockeye recovery. This chapter describes some of those characteristics. In 1995, hydroacoustic estimates of O. nerka densities in the Sawtooth Valley Lakes ranged frommore » 57 to 465 fish/ha. Densities were greatest in Pettit followed by Redfish (167), Alturas (95), and Stanley Lakes. O. nerka numbers increased from 1994 values in Pettit and Alturas Lakes, but declined in Redfish and Stanley. Despite a decline in total lake abundance, O. nerka biomass estimates in Redfish Lake increased. Approximately 144,000 kokanee fry recruited to Redfish Lake from Fishhook Creek. O. nerka fry recruitment to Stanley and Alturas lake was 5,000 and 30,000 fry, respectively. Egg-to-fry survival was 14% in Fishhook and 7% in Stanley Lake Creek. In Fishhook Creek, kokanee spawning escapement was estimated using stream surveys and a weir. Escapement estimates were 4,860 from weir counts, and 7,000 from stream surveys. As part of the kokanee reduction program, 385 of the spawning female kokanee were culled. Escapement for Stanley Lake Creek was only 60 fish, a ten fold decrease from 1994. In Alturas Lake, kokanee spawners dropped by 50% to 1,600.« less

Characteristics of Air Core and Surface Velocity for Water Flow in a Vortex Sediment-Extraction Chamber Measured by Using Photo Images and PTV Technique.

NASA Astrophysics Data System (ADS)

Yao, Hou Chang; Chyan Deng, Jan; Chao, Hsu Yu; Chih Yuan, Yang

2017-04-01

A vortex sediment-extraction chamber, consisted of cylindrical chamber, inflow system, bottom orifice and overflow weir, is used to separate sediment from sediment-laden water flow. A tangential inflow is introduced into a cylindrical chamber with a bottom orifice; thus, a strong vortex flow is produced there. Under actions of gravity and centrifugal force, heavier sediment particles are forced to move towards the bottom orifice, and relatively clear water flows over through the top overflow weir. The flow field in the cylindrical chamber consists of forced vortex and free vortex. When the bottom orifice is opened during the sediment-extraction process, an air core appears and changes with different settings. In this study, the air core and water surface velocity in the cylindrical chamber were measured by using a photo image process and particle tracking velocimetry (PTV), as well as numerically simulated by using a commercial software, Flow-3D.Laboratory experiments were conducted in a vortex chamber, having height of 130 cm and diameter of 48 cm. Five kinds of bottom orifice size from 1.0 cm to 3.0 cm and four kinds of inflow water discharge from 1,300cm3/s to 1,700 cm3/s were used while the inflow pipe of 3 cm in diameter was kept the same for all experiments. The characteristics of the air core and water surface velocity, and the inflow and outflow ratios under different experimental arrangements were observed and discussed so as to provide a better design and application for a vortex sediment-extraction chamber in the future.

Effects of effluents from a coal-fired, electric-generating powerplant on local ground water near Hayden, Colorado

USGS Publications Warehouse

Ellis, S.R.; Mann, P.G.

1981-01-01

Data were collected at the Hayden, Colo., powerplant for about a year during 1978-79 to monitor the effects of effluent and raw-water storage ponds on the local ground water, Sage Creek, and the Yampa River. The concentration of boron in wells downgradient from the effluent ponds indicated that the ponds were leaking, increasing the average boron concentrations in the ground water to a level in excess of the standards for agricultural use of water. Water from seeps, probably the best indicators of downgradient water quality, had average concentrations of boron two times that of the Colorado Department of Health (1977) standard for agricultural use of water. Chemical analyses of water from wells and the discharge weir downgradient from the raw-water storage ponds indicated these ponds are leaking. The effect of this leakage is that the water in wells downgradient from these ponds has a lower specific conductance and a lower boron concentration than the water in wells downgradient from the effluent ponds. The concentration of trace elements in the water from the wells and the discharge weir generally declined during the study, probably because the ground water was recovering from the effects of a plume from the raw-water pond previously used for fly-ash disposal. The effluents from the Hayden powerplant lowered the specific conductance and the iron and manganese concentrations, increased the concentration of boron, and had little or no effect on the selenium concentration in Sage Creek. Sage Creek had no discernible effect on the Yampa River because the volume of water in the Yampa River was so much greater. The effluents from the powerplant also had no discernible effect on the Yampa River. (USGS)

Mitigating agrichemicals from an artificial runoff event using a managed riverine wetland.

PubMed

Lizotte, Richard E; Shields, F Douglas; Murdock, Justin N; Kröger, Robert; Knight, Scott S

2012-06-15

We examined the mitigation efficiency of a managed riverine wetland amended with a mixture of suspended sediment, two nutrients (nitrogen and phosphorus), and three pesticides (atrazine, metolachlor, and permethrin) during a simulated agricultural runoff event. Hydrologic management of the 500 m-long, 25 m-wide riverine wetland was done by adding weirs at both ends. The agrichemical mixture was amended to the wetland at the upstream weir simulating a four-hour, ~1cm rainfall event from a 16ha agricultural field. Water samples (1L) were collected every 30 min within the first 4h, then every 4h until 48 h, and again on days 5, 7, 14, 21, and 28 post-amendment at distances of 0m, 10 m, 40 m, 300 m and 500 m from the amendment point within the wetland for suspended solids, nutrient, and pesticide analyses. Peak sediment, nutrient, and pesticide concentrations occurred within 3 h of amendment at 0m, 10 m, 40 m, and 300 m downstream and showed rapid attenuation of agrichemicals from the water column with 79-98%, 42-98%, and 63-98% decrease in concentrations of sediments, nutrients, and pesticides, respectively, within 48 h. By day 28, all amendments were near or below pre-amendment concentrations. Water samples at 500 m showed no changes in sediment or nutrient concentrations; pesticide concentrations peaked within 48 h but at ≤11% of upstream peak concentrations and had dissipated by day 28. Managed riverine wetlands≥1 ha and with hydraulic residence times of days to weeks can efficiently trap agricultural runoff during moderate (1cm) late-spring and early-summer rainfall events, mitigating impacts to receiving rivers. Published by Elsevier B.V.

Testing of concrete by laser ablation

DOEpatents

Flesher, D.J.; Becker, D.L.; Beem, W.L.; Berry, T.C.; Cannon, N.S.

1997-01-07

A method is disclosed for testing concrete in a structure in situ, by: directing a succession of pulses of laser radiation at a point on the structure so that each pulse effects removal of a quantity of concrete and transfers energy to the concrete; detecting a characteristic of energy which has been transferred to the concrete; determining, separately from the detecting step, the total quantity of concrete removed by the succession of pulses; and calculating a property of the concrete on the basis of the detected energy characteristic and the determined total quantity of concrete removed. 1 fig.

Preface to MOST-ONISW 2009

NASA Astrophysics Data System (ADS)

Doerr, Martin; Freitas, Fred; Guizzardi, Giancarlo; Han, Hyoil

Ontology is a cross-disciplinary field concerned with the study of concepts and theories that can be used for representing shared conceptualizations of specific domains. Ontological Engineering is a discipline in computer and information science concerned with the development of techniques, methods, languages and tools for the systematic construction of concrete artifacts capturing these representations, i.e., models (e.g., domain ontologies) and metamodels (e.g., upper-level ontologies). In recent years, there has been a growing interest in the application of formal ontology and ontological engineering to solve modeling problems in diverse areas in computer science such as software and data engineering, knowledge representation, natural language processing, information science, among many others.

Properties of Concrete partially replaced with Coconut Shell as Coarse aggregate and Steel fibres in addition to its Concrete volume

NASA Astrophysics Data System (ADS)

Kalyana Chakravarthy, P. R.; Janani, R.; Ilango, T.; Dharani, K.

2017-03-01

Cement is a binder material with various composition of Concrete but instantly it posses low tensile strength. The study deals with mechanical properties of that optimized fiber in comparison with conventional and coconut shell concrete. The accumulation of fibers arbitrarily dispersed in the composition increases the resistance to cracking, deflection and other serviceability conditions substantially. The steel fiber in extra is one of the revision in coconut shell concrete and the outcome of steel fiber in coconut shell concrete was to investigate and compare with the conventional concrete. For the given range of steel fibe from 0.5 to 2.0%, 12 beams and 36 cylindrical specimens were cast and tested to find the mechanical properties like flexural strength, split tensile, impact resistance and the modulus of elasticity of both conventional and coconut shell concrete has been studied and the test consequences are compared with the control concrete and coconut shell concrete for M25 Grade. It is fulfilled that, the steel fibers used in this venture has shown significant development in all the properties of conventional and coconut shell concrete while compared to controlled conventional and coconut shell concrete like, Flexural strength by 6.67 % for 1.0 % of steel fiber in conventional concrete and by 5.87 % for 1.5 % of steel fiber in coconut shell concrete.

Fibre Concrete 2017

NASA Astrophysics Data System (ADS)

2017-09-01

9th international conference on fibre reinforced concretes (FRC), textile reinforced concretes (TRC) and ultra-high performance concretes (UHPC) Preface The Fibre Concrete Conference series is held biennially to provide a platform to share knowledge on fibre reinforced concretes, textile concretes and ultra-high performance concretes regarding material properties and behaviour, technology procedures, topics of long-term behaviour, creep, durability; sustainable aspects of concrete including utilisation of waste materials in concrete production and recycling of concrete. The tradition of Fibre Concrete Conferences started in eighties of the last century. Nowadays the conference is organized by the Department of Concrete and Masonry Structures of the Czech Technical University in Prague, Faculty of Civil Engineering. The 9th International Conference Fibre Concrete 2017 had 109 participants from 27 countries all over the world. 55 papers were presented including keynote lectures of Professor Bažant, Professor Bartoš and Dr. Broukalová. The conference program covered wide range of topics from scientific research to practical applications. The presented contributions related to performance and behaviour of cement based composites, their long-term behaviour and durability, sustainable aspects, advanced analyses of structures from these composites and successful applications. This conference was organized also to honour Professor Zděnek P. Bažant on the occasion of his jubilee and to appreciate his merits and discoveries in the field of fibre reinforced composites, structural mechanics and engineering.

Impacts of reforestation and gravel mining on the Malnant River, Haute-Savoie, French Alps

NASA Astrophysics Data System (ADS)

Marston, Richard A.; Bravard, Jean-Paul; Green, Tim

2003-09-01

The Malnant River is a rapidly incising river with a French name that translates as "bad creek," reflecting local opinion of the hazards from dramatic channel changes that have occurred in the last few centuries. Downcutting in the last three decades has created severe problems for farmers in this small watershed (16 km 2) as bridges are undermined, streamside roads are threatened, and irrigation diversion structures are rendered unusable. The purpose of our study was to determine the extent and causes of downcutting. A detailed landcover map dated 1732 revealed that forest cover had been reduced by that time to 10% of the present-day cover. The Malnant was strongly affected by floods and debris torrents during the 18th and 19th centuries that delivered massive amounts of sediment. During the 20th century, reforestation reduced the sediment delivery from hillslopes. In addition, gravel extraction in the Malnant and in the Fier River (of which the Malnant is a tributary) has lowered the base level for the river. This initiated a knickpoint that moved upstream. Weirs placed in the Malnant in 1968 were used to measure rates of bed incision in the field. With a mean width of 4.0 m and degradation up to 36 cubic meters per meter channel length, the lower 4.5 km of the Malnant has experienced a net loss of approximately 163,000 m 3 of bed material. Above the 4.5-km point on the Malnant, bedrock controls exist that have arrested the upstream-progressing degradation.

Placement of mass concrete for cast-in-place concrete piling : the effects of heat of hydration of mass concrete for cast-in-place piles.

DOT National Transportation Integrated Search

2008-12-01

This report describes models, ABAQUS and Schmidt, to predict the peak temperature in the center of cast-in-place concrete piling. Five concrete piles with varying diameters and made up of concrete mixes with different percentage of fly ash are used. ...

Monitoring the corrosion process of reinforced concrete using BOTDA and FBG sensors.

PubMed

Mao, Jianghong; Chen, Jiayun; Cui, Lei; Jin, Weiliang; Xu, Chen; He, Yong

2015-04-15

Expansion and cracking induced by the corrosion of reinforcement concrete is the major factor in the failure of concrete durability. Therefore, monitoring of concrete cracking is critical for evaluating the safety of concrete structures. In this paper, we introduce a novel monitoring method combining Brillouin optical time domain analysis (BOTDA) and fiber Bragg grating (FBG), based on mechanical principles of concrete expansion cracking. BOTDA monitors concrete expansion and crack width, while FBG identifies the time and position of cracking. A water-pressure loading simulation test was carried out to determine the relationship between fiber strain, concrete expansion and crack width. An electrical accelerated corrosion test was also conducted to evaluate the ability of this novel sensor to monitor concrete cracking under practical conditions.

Acoustic emission monitoring of concrete columns and beams strengthened with fiber reinforced polymer sheets

NASA Astrophysics Data System (ADS)

Ma, Gao; Li, Hui; Zhou, Wensong; Xian, Guijun

2012-04-01

Acoustic emission (AE) technique is an effective method in the nondestructive testing (NDT) field of civil engineering. During the last two decades, Fiber reinforced polymer (FRP) has been widely used in repairing and strengthening concrete structures. The damage state of FRP strengthened concrete structures has become an important issue during the service period of the structure and it is a meaningful work to use AE technique as a nondestructive method to assess its damage state. The present study reports AE monitoring results of axial compression tests carried on basalt fiber reinforced polymer (BFRP) confined concrete columns and three-point-bending tests carried on BFRP reinforced concrete beams. AE parameters analysis was firstly utilized to give preliminary results of the concrete fracture process of these specimens. It was found that cumulative AE events can reflect the fracture development trend of both BFRP confined concrete columns and BFRP strengthened concrete beams and AE events had an abrupt increase at the point of BFRP breakage. Then the fracture process of BFRP confined concrete columns and BFRP strengthened concrete beams was studied through RA value-average frequency analysis. The RA value-average frequency tendencies of BFRP confined concrete were found different from that of BFRP strengthened concrete beams. The variation tendency of concrete crack patterns during the loading process was revealed.

Shear transfer in concrete reinforced with carbon fibers

NASA Astrophysics Data System (ADS)

El-Mokadem, Khaled Mounir

2001-10-01

Scope and method of study. The research started with preliminary tests and studies on the behavior and effect of carbon fibers in different water solutions and mortar/concrete mixes. The research work investigated the use of CF in the production of concrete pipes and prestressed concrete double-tee sections. The research then focused on studying the effect of using carbon fibers on the direct shear transfer of sand-lightweight reinforced concrete push-off specimens. Findings and conclusions. In general, adding carbon fibers to concrete improved its tensile characteristics but decreased its compressive strength. The decrease in compressive strength was due to the decrease in concrete density as fibers act as three-dimensional mesh that entrapped air. The decrease in compressive strength was also due to the increase in the total surface area of non-cementitious material in the concrete. Sand-lightweight reinforced concrete push-off specimens with carbon fibers had lower shear carrying capacity than those without carbon fibers for the same cement content in the concrete. Current building codes and specifications estimate the shear strength of concrete as a ratio of the compressive strength. If applying the same principals then the ratio of shear strength to compressive strength for concrete reinforced with carbon fibers is higher than that for concrete without carbon fibers.

Effects of climate and corrosion on concrete behaviour

NASA Astrophysics Data System (ADS)

Ismail, Mohammad; Egba, Ernest Ituma

2017-11-01

Corrosion of steel is a damaging agent that reduces the functional and structural responsibilities of reinforced concrete structures. Accordingly, reinforced concrete members in the environments that are prone to concrete carbonation or chloride attack coupled with high temperature and relative humidity suffer from accelerated corrosion of reinforcing material. Also, literature proves that climate influences corrosion of concrete, and suggests investigation of impact of corrosion on concrete based on climate zone. Therefore, this paper presents the effects of climate and corrosion on concrete behavior, using bond strength of concrete as a case study. Concrete specimens were prepared form concrete mix that was infested with 3.5 kgm-3 of sodium chloride to accelerate corrosion. The specimens were cured sodium chloride solution 3.5% by weight of water for 28 days before placing them in the exposure conditions. Pull-out tests were conducted at time intervals for one year to measure the impact of exposure condition and corrosion on bond strength of concrete. The results show reduction of bond strength of concrete by 32%, 28% and 8% after one year of subjection of the specimens to the unsheltered natural climate, sheltered natural climate, and laboratory ambient environment respectively. The findings indicate that the climate influences corrosion, which reduces the interlocking bond between the reinforcing bar and the adjacent concrete.

Mechanical Properties and Eco-Efficiency of Steel Fiber Reinforced Alkali-Activated Slag Concrete.

PubMed

Kim, Sun-Woo; Jang, Seok-Joon; Kang, Dae-Hyun; Ahn, Kyung-Lim; Yun, Hyun-Do

2015-10-30

Conventional concrete production that uses ordinary Portland cement (OPC) as a binder seems unsustainable due to its high energy consumption, natural resource exhaustion and huge carbon dioxide (CO₂) emissions. To transform the conventional process of concrete production to a more sustainable process, the replacement of high energy-consumptive PC with new binders such as fly ash and alkali-activated slag (AAS) from available industrial by-products has been recognized as an alternative. This paper investigates the effect of curing conditions and steel fiber inclusion on the compressive and flexural performance of AAS concrete with a specified compressive strength of 40 MPa to evaluate the feasibility of AAS concrete as an alternative to normal concrete for CO₂ emission reduction in the concrete industry. Their performances are compared with reference concrete produced using OPC. The eco-efficiency of AAS use for concrete production was also evaluated by binder intensity and CO₂ intensity based on the test results and literature data. Test results show that it is possible to produce AAS concrete with compressive and flexural performances comparable to conventional concrete. Wet-curing and steel fiber inclusion improve the mechanical performance of AAS concrete. Also, the utilization of AAS as a sustainable binder can lead to significant CO₂ emissions reduction and resources and energy conservation in the concrete industry.

Low Shrinkage Cement Concrete Intended for Airfield Pavements

NASA Astrophysics Data System (ADS)

Małgorzata, Linek

2017-10-01

The work concerns the issue of hardened concrete parameters improvement intended for airfield pavements. Factors which have direct or indirect influence on rheological deformation size were of particular interest. The aim of lab testing was to select concrete mixture ratio which would make hardened concrete less susceptible to influence of basic operating factors. Analyses included two research groups. External and internal factors were selected. They influence parameters of hardened cement concrete by increasing rheological deformations. Research referred to innovative cement concrete intended for airfield pavements. Due to construction operation, the research considered the influence of weather conditions and forced thermal loads intensifying concrete stress. Fresh concrete mixture parameters were tested and basic parameters of hardened concrete were defined (density, absorbability, compression strength, tensile strength). Influence of the following factors on rheological deformation value was also analysed. Based on obtained test results, it has been discovered that innovative concrete, made on the basis of modifier, which changes internal structure of concrete composite, has definitely lower values of rheological deformation. Observed changes of microstructure, in connection with reduced deformation values allowed to reach the conclusion regarding advantageous characteristic features of the newly designed cement concrete. Applying such concrete for airfield construction may contribute to extension of its operation without malfunction and the increase of its general service life.

Utilization of construction and agricultural waste in Malaysia for development of Green Concrete: A Review

NASA Astrophysics Data System (ADS)

Tambichik, M. A.; Mohamad, N.; Samad, A. A. A.; Bosro, M. Z. M.; Iman, M. A.

2018-04-01

Green Concrete (GC) is defined as a concrete that utilize a waste material for at least one of its component. The production of GC has been increasing due to the drawback of conventional concrete that create many environmental problems. In Malaysia, the amount of waste generates from agricultural and construction industries were increasing every year. Hence, one of the solutions to reduce the impact of conventional concrete and limited landfill spaces due to excessive waste is by utilizing it in concrete. This paper reviews the possible use of construction waste (Recycle Concrete Aggregate) and agricultural waste (Palm Oil Fuel Ash, Rice Husk Ash and Palm Oil Fibre) as partial replacement for the basic material in a concrete to produce an innovative Green Concrete. The optimum replacement level for each type of waste was also been review. Green Concrete also has the potential to reduce environmental pollution and solve the depletion of natural sources. The result from this review shows that the addition of agricultural waste or construction waste in concrete indicate positive and satisfactory strength when compared to normal concrete. Finally, a mass production of Green Concrete can fulfil the Construction Industry Transformation Plan (CITP) 2016-2020 made by CIDB that emphasizes on a construction system which is environmentally sustainable.

Palm Oil Fuel Ash (POFA) and Eggshell Powder (ESP) as Partial Replacement for Cement in Concrete

NASA Astrophysics Data System (ADS)

Ezdiani Mohamad, Mazizah; Mahmood, Ali A.; Min, Alicia Yik Yee; Nur Nadhira A., R.

2018-03-01

This study is an attempt to partially replace Ordinary Portland cement (OPC) in concrete with palm oil fuel ash (POFA) and eggshell powder (ESP). The mix proportions of POFA and ESP were varied at 10% of cement replacement and compared with OPC concrete as control specimen. The fineness of POFA is characterized by passing through 300 μm sieve and ESP by passing through 75 μm sieve. Compressive strength testing was conducted on concrete specimens to determine the optimum mix proportion of POFA and ESP. Generally the compressive strength of OPC concrete is higher compared to POFA-ESP concrete. Based on the results of POFA-ESP concrete overall, it shows that the optimum mix proportion of concrete is 6%POFA:4% ESP achieved compressive strength of 38.60 N/mm2 at 28 days. The compressive strength of OPC concrete for the same period was 42.37 N/mm2. Higher water demand in concrete is needed due to low fineness of POFA that contributing to low compressive strength of POFA-ESP concrete. However, the compressive strength and workability of the POFA-ESP concrete were within the ranges typically encountered in regular concrete mixtures indicating the viability of this replacement procedure for structural and non-structural applications.

Experimental investigation of photocatalytic effects of concrete in air purification adopting entire concrete waste reuse model.

PubMed

Xu, Yidong; Chen, Wei; Jin, Ruoyu; Shen, Jiansheng; Smallbone, Kirsty; Yan, Chunyang; Hu, Lei

2018-07-05

This research investigated the capacities of recycled aggregate concrete adopting entire concrete waste reuse model in degrading NO 2. Two major issues within environmental sustainability were addressed: concrete waste reuse rate and mitigation of hazards substances in the polluted air. The study consisted of two stages: identification of proper replacement rates of recycled concrete wastes in new concrete mixture design, and the evaluation of photocatalytic performance of recycled aggregate concrete in degrading NO 2 . It was found that replacement rates up to 3%, 30%, and 50% for recycled power, recycled fine aggregate, and recycled coarse aggregate respectively could be applied in concrete mixture design without deteriorating concrete strength. Recycled aggregates contained both positive attributes ("internal curing") and negative effects (e.g., lower hardness) to concrete properties. It was found that 30%-50% of natural coarse aggregate replaced by recycled coarse aggregates coated with TiO 2 would significantly improve the photocatalytic performance of concrete measured by degradation rate of NO 2 . Micro-structures of recycled aggregates observed under microscope indicated that soaking recycled aggregates in TiO 2 solution resulted in whiskers that filled the porosity within recycled aggregates which enhanced concrete strength. Copyright © 2018 Elsevier B.V. All rights reserved.

Evaluation of recycled concrete as aggregate in new concrete pavements.

DOT National Transportation Integrated Search

2014-04-01

This study evaluated the use of recycled concrete as coarse aggregate in new concrete pavements. : Recycled concrete aggregate (RCA) produced from demolished pavements in three geographically dispersed locations in Washington state were used to perfo...

The anthropogenic nature of present-day low energy rivers in western France and implications for current restoration projects

NASA Astrophysics Data System (ADS)

Lespez, L.; Viel, V.; Rollet, A. J.; Delahaye, D.

2015-12-01

As in other European countries, western France has seen an increase in river restoration projects. In this paper, we examine the restoration goals, methods and objectives with respect to the long-term trajectory and understanding of the contemporary dynamics of the small low energy rivers typical of the lowlands of Western Europe. The exhaustive geomorphological, paleoenvironmental and historical research conducted in the Seulles river basin (Normandy) provides very accurate documentation of the nature and place of the different legacies in the fluvial systems we have inherited. The sedimentation rate in the Seulles valley bottom has multiplied by a factor of 20 since the end of the Bronze Age and has generated dramatic changes in fluvial forms. Hydraulic control of the rivers and valley bottoms drainage throughout the last millennium has channelized rivers within these deposits. The single meandering channel which characterizes this river today is the legacy of the delayed and complex effects of long term exploitation of the river basin and the fluvial system. Bring to light that the "naturalness" of the restored rivers might be questioned. Our research emphasizes the gap between the poor knowledge of the functioning of these rivers and the concrete objectives of the restoration works undertaken, including dam and weir removal. Account of the long-term history of fluvial systems is required, not only to produce a pedagogic history of the "river degradation" but more fundamentally (i) to situate the current functioning of the fluvial system in a trajectory to try to identify thresholds and anticipate the potential turning points in a context of climate and land use change, (ii) to understand the role of morphosedimentary legacies on the current dynamics, (iii) to open the discussion on reference functioning or expected states and (iv) to open discussion on the sustainability of ecological restoration. To conclude, we point out the necessity to take into account the hybrid nature of low energy rivers in rural environments and to develop specific evaluation protocols which would include both biophysical processes and usual human activities which could be a way to share the evaluation and overcome conflicts between socioeconomic needs and environmental issues.

Concrete with onyx waste aggregate as aesthetically valued structural concrete

NASA Astrophysics Data System (ADS)

Setyowati E., W.; Soehardjono, A.; Wisnumurti

2017-09-01

The utillization of Tulungagung onyx stone waste as an aggregate of concrete mixture will improve the economic value of the concrete due to the brighter color and high aesthetic level of the products. We conducted the research of 75 samples as a test objects to measure the compression stress, splits tensile stress, flexural tensile stress, elasticity modulus, porosity modulus and also studied 15 test objects to identify the concrete micro structures using XRD test, EDAX test and SEM test. The test objects were made from mix designed concrete, having ratio cement : fine aggregate : coarse aggregate ratio = 1 : 1.5 : 2.1, and W/C ratio = 0.4. The 28 days examination results showed that the micro structure of Tulungagung onyx waste concrete is similar with normal concrete. Moreover, the mechanical test results proved that Tulungagung onyx waste concretes also have a qualified level of strength to be used as a structural concrete with higher aesthetic level.

Experimental Study of Damage Evolution in Circular Stirrup-Confined Concrete

PubMed Central

Li, Zuohua; Peng, Zhihan; Teng, Jun; Wang, Ying

2016-01-01

This paper presents an experimental study on circular stirrup-confined concrete specimens under uniaxial and monotonic load. The effects of stirrup volume ratio, stirrup yield strength and concrete strength on damage evolution of stirrup-confined concrete were investigated. The experimental results showed that the strength and ductility of concrete are improved by appropriate arrangement of the stirrup confinement. Firstly, the concrete damage evolution can be relatively restrained with the increase of the stirrup volume ratio. Secondly, higher stirrup yield strength usually causes larger confining pressures and slower concrete damage evolution. In contrast, higher concrete strength leads to higher brittleness, which accelerates the concrete damage evolution. A plastic strain expression is obtained through curve fitting, and a damage evolution equation for circular stirrup-confined concrete is proposed by introducing a confinement factor (C) based on the experimental data. The comparison results demonstrate that the proposed damage evolution model can accurately describe the experimental results. PMID:28773402

Experimental Study of Damage Evolution in Circular Stirrup-Confined Concrete.

PubMed

Li, Zuohua; Peng, Zhihan; Teng, Jun; Wang, Ying

2016-04-08

This paper presents an experimental study on circular stirrup-confined concrete specimens under uniaxial and monotonic load. The effects of stirrup volume ratio, stirrup yield strength and concrete strength on damage evolution of stirrup-confined concrete were investigated. The experimental results showed that the strength and ductility of concrete are improved by appropriate arrangement of the stirrup confinement. Firstly, the concrete damage evolution can be relatively restrained with the increase of the stirrup volume ratio. Secondly, higher stirrup yield strength usually causes larger confining pressures and slower concrete damage evolution. In contrast, higher concrete strength leads to higher brittleness, which accelerates the concrete damage evolution. A plastic strain expression is obtained through curve fitting, and a damage evolution equation for circular stirrup-confined concrete is proposed by introducing a confinement factor ( C ) based on the experimental data. The comparison results demonstrate that the proposed damage evolution model can accurately describe the experimental results.

Comparison of physical and mechanical properties of river sand concrete with quarry dust concrete

NASA Astrophysics Data System (ADS)

Opara, Hyginus E.; Eziefula, Uchechi G.; Eziefula, Bennett I.

2018-03-01

This study compared the physical and mechanical properties of river sand concrete with quarry dust concrete. The constituent materials were batched by weight. The water-cement ratio and mix ratio selected for the experimental investigation were 0.55 and 1:2:4, respectively. The specimens were cured for 7, 14, 21 and 28 days. Slump, density and compressive strength tests were carried out. The results showed that river sand concrete had greater density and compressive strength than quarry dust concrete for all curing ages. At 28 days of curing, river sand concrete exceeded the target compressive strength by 36%, whereas quarry dust concrete was less than the target compressive strength by 12%. Both river sand concrete and quarry dust concrete for the selected water/cement ratio and mix ratio are suitable for non-structural applications and lightly-loaded members where high strength is not a prerequisite.

Freeze-thaw durability of concrete: Ice formation process in pores

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cai, H.; Liu, X.

1998-09-01

Freeze-thaw durability of concrete is of great importance to hydraulic structures in cold areas. Study of ice formation process in concrete pores is necessary to evaluate the damages in concrete caused by freezing. In this paper, freezing of pore solution in concrete exposed to a freeze-thaw cycle is studied by following the change of concrete electrical conductivity with freezing temperatures. Concretes were subjected to freeze-thaw cycles with temperature varying between {minus}0 C and {minus}20 C. In the freezing process, the changing rate of concrete electrical conductivity obviously decreases at about {minus}10 C, indicating that more pore solution in concrete freezesmore » above {minus}10 C than below {minus}10C. According to Powers` static hydraulic pressure hypothesis, it is thought that frost damage mainly occurs between 0 C and {minus}100 C. To ordinary concrete, frost damages below {minus}10 C are negligible.« less

Bond characteristics of reinforcing steel embedded in geopolymer concrete

NASA Astrophysics Data System (ADS)

Kathirvel, Parthiban; Thangavelu, Manju; Gopalan, Rashmi; Raja Mohan Kaliyaperumal, Saravana

2017-07-01

The force transferring between reinforcing steel and the surrounding concrete in reinforced concrete is influenced by several factors. Whereas, the study on bond behaviour of geopolymer concrete (GPC) is lagging. In this paper, an experimental attempt has been made to evaluate the geopolymer concrete bond with reinforcing steel of different diameter and embedded length using standard pull out test. The geopolymer concrete is made of ground granulated blast furnace slag (GGBFS) as geopolymer source material (GSM). The tests were conducted to evaluate the development of bond between steel and concrete of grade M40 and M50 with 12 and 16 mm diameter reinforcing steel for geopolymer and cement concrete mixes and to develop a relation between bond strength and compressive strength. From the experimental results, it has been observed that the bond strength of the geopolymer concrete mixes was more compared to the cement concrete mixes and increases with the reduction in the diameter of the bar.

Quick-setting concrete and a method for making quick-setting concrete

DOEpatents

Wagh, A.S.; Singh, D.; Pullockaran, J.D.; Knox, L.

1997-04-29

A method for producing quick setting concrete is provided comprising mixing a concrete dry mixture with carbonate solution to create a slurry, and allowing the slurry to cure. The invention also provides for a quick setting concrete having a predetermined proportion of CaCO{sub 3} of between 5 and 23 weight percent of the entire concrete mixture, and whereby the concrete has a compression strength of approximately 4,000 pounds per square inch (psi) within 24 hours after pouring. 2 figs.

Quick-setting concrete and a method for making quick-setting concrete

DOEpatents

Wagh, Arun S.; Singh, Dileep; Pullockaran, Jose D.; Knox, Lerry

1997-01-01

A method for producing quick setting concrete is provided comprising hydrng a concrete dry mixture with carbonate solution to create a slurry, and allowing the slurry to cure. The invention also provides for a quick setting concrete having a predetermined proportion of CaCO.sub.3 of between 5 and 23 weight percent of the entire concrete mixture, and whereby the concrete has a compression strength of approximately 4,000 pounds per square inch (psi) within 24 hours after pouring.

Allelic variation contributes to bacterial host specificity

DOE PAGES

Yue, Min; Han, Xiangan; Masi, Leon De; ...

2015-10-30

Understanding the molecular parameters that regulate cross-species transmission and host adaptation of potential pathogens is crucial to control emerging infectious disease. Although microbial pathotype diversity is conventionally associated with gene gain or loss, the role of pathoadaptive nonsynonymous single-nucleotide polymorphisms (nsSNPs) has not been systematically evaluated. Here, our genome-wide analysis of core genes within Salmonella enterica serovar Typhimurium genomes reveals a high degree of allelic variation in surface-exposed molecules, including adhesins that promote host colonization. Subsequent multinomial logistic regression, MultiPhen and Random Forest analyses of known/suspected adhesins from 580 independent Typhimurium isolates identifies distinct host-specific nsSNP signatures. Moreover, population andmore » functional analyses of host-associated nsSNPs for FimH, the type 1 fimbrial adhesin, highlights the role of key allelic residues in host-specific adherence in vitro. In conclusion, together, our data provide the first concrete evidence that functional differences between allelic variants of bacterial proteins likely contribute to pathoadaption to diverse hosts.« less

Understanding disgust.

PubMed

Chapman, Hanah A; Anderson, Adam K

2012-03-01

Disgust is characterized by a remarkably diverse set of stimulus triggers, ranging from extremely concrete (bad tastes and disease vectors) to extremely abstract (moral transgressions and those who commit them). This diversity may reflect an expansion of the role of disgust over evolutionary time, from an origin in defending the body against toxicity and disease, through defense against other threats to biological fitness (e.g., incest), to involvement in the selection of suitable interaction partners, by motivating the rejection of individuals who violate social and moral norms. The anterior insula, and to a lesser extent the basal ganglia, are implicated in toxicity- and disease-related forms of disgust, although we argue that insular activation is not exclusive to disgust. It remains unclear whether moral disgust is associated with insular activity. Disgust offers cognitive neuroscientists a unique opportunity to study how an evolutionarily ancient response rooted in the chemical senses has expanded into a uniquely human social cognitive domain; many interesting research avenues remain to be explored. © 2012 New York Academy of Sciences.

Use of roller-compacted concrete pavement in Stafford, Virginia.

DOT National Transportation Integrated Search

2015-05-01

Roller-compacted concrete (RCC) is a relatively stiffer hydraulic cement concrete mixture than regular concrete when : fresh. Similar to regular concrete, RCC is a mixture of aggregate, cementitious materials, and water, but it is placed using asphal...

Ultra-high performance concrete for Michigan bridges, material performance : phase I.

DOT National Transportation Integrated Search

2008-10-13

One of the latest advancements in concrete technology is Ultra-High Performance Concrete (UHPC). UHPC is : defined as concretes attaining compressive strengths exceeding 25 ksi (175 MPa). It is a fiber-reinforced, denselypacked : concrete material wh...

Concrete density estimation by rebound hammer method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ismail, Mohamad Pauzi bin, E-mail: pauzi@nm.gov.my; Masenwat, Noor Azreen bin; Sani, Suhairy bin

Concrete is the most common and cheap material for radiation shielding. Compressive strength is the main parameter checked for determining concrete quality. However, for shielding purposes density is the parameter that needs to be considered. X- and -gamma radiations are effectively absorbed by a material with high atomic number and high density such as concrete. The high strength normally implies to higher density in concrete but this is not always true. This paper explains and discusses the correlation between rebound hammer testing and density for concrete containing hematite aggregates. A comparison is also made with normal concrete i.e. concrete containingmore » crushed granite.« less

Monitoring the Corrosion Process of Reinforced Concrete Using BOTDA and FBG Sensors

PubMed Central

Mao, Jianghong; Chen, Jiayun; Cui, Lei; Jin, Weiliang; Xu, Chen; He, Yong

2015-01-01

Expansion and cracking induced by the corrosion of reinforcement concrete is the major factor in the failure of concrete durability. Therefore, monitoring of concrete cracking is critical for evaluating the safety of concrete structures. In this paper, we introduce a novel monitoring method combining Brillouin optical time domain analysis (BOTDA) and fiber Bragg grating (FBG), based on mechanical principles of concrete expansion cracking. BOTDA monitors concrete expansion and crack width, while FBG identifies the time and position of cracking. A water-pressure loading simulation test was carried out to determine the relationship between fiber strain, concrete expansion and crack width. An electrical accelerated corrosion test was also conducted to evaluate the ability of this novel sensor to monitor concrete cracking under practical conditions. PMID:25884790

The effect of word concreteness on recognition memory.

PubMed

Fliessbach, K; Weis, S; Klaver, P; Elger, C E; Weber, B

2006-09-01

Concrete words that are readily imagined are better remembered than abstract words. Theoretical explanations for this effect either claim a dual coding of concrete words in the form of both a verbal and a sensory code (dual-coding theory), or a more accessible semantic network for concrete words than for abstract words (context-availability theory). However, the neural mechanisms of improved memory for concrete versus abstract words are poorly understood. Here, we investigated the processing of concrete and abstract words during encoding and retrieval in a recognition memory task using event-related functional magnetic resonance imaging (fMRI). As predicted, memory performance was significantly better for concrete words than for abstract words. Abstract words elicited stronger activations of the left inferior frontal cortex both during encoding and recognition than did concrete words. Stronger activation of this area was also associated with successful encoding for both abstract and concrete words. Concrete words elicited stronger activations bilaterally in the posterior inferior parietal lobe during recognition. The left parietal activation was associated with correct identification of old stimuli. The anterior precuneus, left cerebellar hemisphere and the posterior and anterior cingulate cortex showed activations both for successful recognition of concrete words and for online processing of concrete words during encoding. Additionally, we observed a correlation across subjects between brain activity in the left anterior fusiform gyrus and hippocampus during recognition of learned words and the strength of the concreteness effect. These findings support the idea of specific brain processes for concrete words, which are reactivated during successful recognition.

Report of concrete pavement evaluation : project 105 C-4181-01 Donahoo Road, Wyandotte County.

DOT National Transportation Integrated Search

2013-12-01

The physical properties of hardened concrete cores and fresh concrete test results were compared with aggregate : gradation workability differences. The concrete cores were taken from a rural two-lane concrete road in northeastern Kansas : constructe...

Best practices for concrete pumping.

DOT National Transportation Integrated Search

2016-12-01

Pumping is one of the major placement techniques used in the concrete industry to deliver concrete : from the mixing truck to the formwork. Although concrete pumping has been used to place concrete since : the 1960s, there is still a lack of exact kn...

Lightweight Concrete : Mechanical Properties : TechBrief

DOT National Transportation Integrated Search

2013-06-01

There is a limited amount of test data on the mechanical properties of high-strength lightweight concrete (LWC) with a concrete unit weight (wc) between that of traditional LWC and normal weight concrete (NWC). Concrete with a wc in this range is als...

Molecular Survey of Concrete Sewer Biofilm Microbial Communities

EPA Science Inventory

Although bacteria are implicated in deteriorating concrete structures, there is very little information on the composition of concrete microbial communities. To this end, we studied different concrete biofilms by performing sequence analysis of 16S rDNA concrete clone libraries. ...

Ground tire rubber (GTR) as a component material in concrete mixtures for paving concrete, phase 2 : [summary].

DOT National Transportation Integrated Search

2015-02-01

Using ground tire rubber (GTR) in : concrete mixtures is a possible solution : to mitigating flexibility and thermal : expansion issues with high-strength : concrete pavements. Florida State : University researchers designed concrete : mixtures using...

Performance of Microbial Concrete Developed Using Bacillus Subtilus JC3

NASA Astrophysics Data System (ADS)

Rao, M. V. Seshagiri; Reddy, V. Srinivasa; Sasikala, Ch.

2017-12-01

Concrete is vulnerable to deterioration, corrosion, and cracks, and the consequent damage and loss of strength requires immensely expensive remediation and repair. So need for special concrete that they would respond to crack formation with an autonomous self-healing action lead to research and development of microbial concrete. The microbial concrete works on the principle of calcite mineral precipitation by a specific group of alkali-resistant spore-forming bacteria related to the genus Bacillus called Bacillus subtilis JC3, this phenomenon is called biomineralization or Microbiologically Induced Calcite Crystal Precipitation. Bacillus subtilis JC3, a common soil bacterium, has inherent ability to precipitate calcite crystals continuously which enhances the strength and durability performance of concrete enormously. This microbial concrete can be called as a "Self healing Bacterial Concrete" because it can remediate its cracks by itself without any human intervention and would make the concrete more durable and sustainable. This paper discuss the incorporation of microorganism Bacillus subtilis JC3 (developed at JNTU, India) into concrete and presents the results of experimental investigations carried out to study the improved durability and sustainability characteristics of microbial concrete.

Studies of detailed biofilm characterization on fly ash concrete in comparison with normal and superplasticizer concrete in seawater environments.

PubMed

Vishwakarmaa, Vinita; George, R P; Ramachandran, D; Anandkumar, B; Mudalib, U Kamachi

2014-01-01

In cooling water systems, many concrete structures in the form of tanks, pillars and reservoirs that come in contact with aggressive seawater are being deteriorated by chemical and biological factors. The nuclear industry has decided to partially replace the Portland cement with appropriate pozzolans such as fly ash, which could densify the matrix and make the concrete impermeable. Three types of concrete mixes, viz., normal concrete (NC), concrete with fly ash and superplasticizer (FA) and concrete with only superplasticizer (SP) were fabricated for short- and long-term exposure studies and for screening out the better concrete in seawater environments. Biofilm characterization studies and microscopic studies showed excellent performance of FA concrete compared to the other two. Laboratory exposure studies in pure cultures of Thiobacillus thiooxidans and Fusarium oxysporum were demonstrated for the inhibition of microbial growth on fly ash. Epifluorescence and scanning electron microscopic studies supported the better performance of the FA specimen. Thus, the present study clearly showed that FA concrete is less prone to biofilm formation and biodeterioration.

Aggregate Effect on the Concrete Cone Capacity of an Undercut Anchor under Quasi-Static Tensile Load

PubMed Central

Marcon, Marco; Ninčević, Krešimir; Boumakis, Ioannis; Czernuschka, Lisa-Marie

2018-01-01

In the last decades, fastening systems have become an essential part of the construction industry. Post-installed mechanical anchors are frequently used in concrete members to connect them with other load bearing structural members, or to attach appliances. Their performance is limited by the concrete related failure modes which are highly influenced by the concrete mix design. This paper aims at investigating the effect that different aggregates used in the concrete mix have on the capacity of an undercut anchor under tensile quasi-static loading. Three concrete batches were cast utilising three different aggregate types. For two concrete ages (28 and 70 days), anchor tensile capacity and concrete properties were obtained. Concrete compressive strength, fracture energy and elastic modulus are used to normalize and compare the undercut anchor concrete tensile capacity employing some of the most widely used prediction models. For a more insightful comparison, a statistical method that yields also scatter information is introduced. Finally, the height and shape of the concrete cones are compared by highly precise and objective photogrammetric means. PMID:29723972

Aggregate Effect on the Concrete Cone Capacity of an Undercut Anchor under Quasi-Static Tensile Load.

PubMed

Marcon, Marco; Ninčević, Krešimir; Boumakis, Ioannis; Czernuschka, Lisa-Marie; Wan-Wendner, Roman

2018-05-01

In the last decades, fastening systems have become an essential part of the construction industry. Post-installed mechanical anchors are frequently used in concrete members to connect them with other load bearing structural members, or to attach appliances. Their performance is limited by the concrete related failure modes which are highly influenced by the concrete mix design. This paper aims at investigating the effect that different aggregates used in the concrete mix have on the capacity of an undercut anchor under tensile quasi-static loading. Three concrete batches were cast utilising three different aggregate types. For two concrete ages (28 and 70 days), anchor tensile capacity and concrete properties were obtained. Concrete compressive strength, fracture energy and elastic modulus are used to normalize and compare the undercut anchor concrete tensile capacity employing some of the most widely used prediction models. For a more insightful comparison, a statistical method that yields also scatter information is introduced. Finally, the height and shape of the concrete cones are compared by highly precise and objective photogrammetric means.

Evaluation of workability and strength of green concrete using waste steel scrap

NASA Astrophysics Data System (ADS)

Neeraja, D.; Arshad, Shaik Mohammed; Nawaz Nadaf, Alisha K.; Reddy, Mani Kumar

2017-11-01

This project works on the study of workability and mechanical properties of concrete using waste steel scrap from the lathe industry. Lathe industries produce waste steel scrap from the lathe machines. In this study, an attempt is made to use this waste in concrete, as accumulation of waste steel scrap cause disposal problem. Tests like compressive test, split tensile test, NDT test (UPV test) were conducted to determine the impact of steel scrap in concrete. The percentages of steel scrap considered in the study were 0%, 0.5%, 1%, 1.5%, and 2% respectively by volume of concrete, 7 day, 28 days test were conducted to find out strength of steel scrap concrete. It is observed that split tensile strength of steel scrap concrete is increased slightly. Split tensile strength of Steel scrap concrete is found to be maximum with volume fraction of 2.0% steel scrap. The steel scrap gives good result in split tensile strength of concrete. From the study concluded that steel scrap can be used in concrete to reduce brittleness of concrete to some extent.

Physical-durable performance of concrete incorporating high loss on ignition-fly ash

NASA Astrophysics Data System (ADS)

Huynh, Trong-Phuoc; Ngo, Si-Huy; Hwang, Chao-Lung

2018-04-01

This study investigates the feasibility of using raw fly ash with a high loss on ignition in concrete. The fly ash-free concrete samples were prepared with different water-to-binder (w/b) ratios of 0.35, 0.40, and 0.45, whereas the fly ash concrete samples were prepared with a constant w/b of 0.40 and with various fly ash contents (10%, 20%, and 30%) as a cement substitution. The physical properties and durability performance of the concretes were evaluated through fresh concrete properties, compressive strength, strength efficiency of cement, ultrasonic pulse velocity, and resistance to sulfate attack. Test results show that the w/b ratio affected the concrete properties significantly. The incorporation of fly ash increased the workability and reduced the unit weight of fresh concrete. In addition, the fly ash concrete samples containing up to 20% fly ash exhibited an improved strength at long-term ages. Further, all of the fly ash concrete samples showed a good durability performance with ultrasonic pulse velocity value of greater than 4100 m/s and a comparable sulfate resistance to the no-fly ash concrete.

Influence of seawater mixing and curing on strength characteristics and porosity of ground granulated blast-furnace slag concrete

NASA Astrophysics Data System (ADS)

Adiwijaya; Hamada, H.; Sagawa, Y.; Yamamoto, D.

2017-11-01

Generally, in the concrete industry, several billion tons of fresh water are annually used for mixing water, curing water and cleaning water. Nevertheless, the utilization of seawater in the concrete industry is prohibited, because it increases the risk of corrosion of steel bars in concrete. This study presents strength characteristics and porosity of seawater mixed concrete and tap water mixed concrete incorporating Ground Granulated Blast-Furnace Slag (GGBS) with water-binder ratio (W/B) of 40%, 50% and 60%. The influence of seawater mixing, GGBS and curing conditions such as tap water curing (TC), seawater curing (SC) and air curing (AC) on the strength and porosity of concrete were evaluated. Based on investigation result, it was shown that there is no significant influence of seawater mixing in improving strength of GGBS concrete up to 365 days in TC and SC. Effectiveness of seawater-mixing on strength enhancement of GGBS concrete is larger in air curing than in water curing. Porosity of seawater-mixed concrete is decreased compared to tap water-mixed concrete in all curing conditions.

Smart Crack Control in Concrete through Use of Phase Change Materials (PCMs): A Review

PubMed Central

2018-01-01

Cracks in concrete structures present a threat to their durability. Therefore, numerous research studies have been devoted to reducing concrete cracking. In recent years, a new approach has been proposed for controlling temperature related cracking—utilization of phase change materials (PCMs) in concrete. Through their ability to capture heat, PCMs can offset temperature changes and reduce gradients in concrete structures. Nevertheless, they can also influence concrete properties. This paper presents a comprehensive overview of the literature devoted to using PCMs to control temperature related cracking in concrete. First, types of PCMs and ways of incorporation in concrete are discussed. Then, possible uses of PCMs in concrete technology are discussed. Further, the influences of PCMs on concrete properties (fresh, hardened, durability) are discussed in detail. This is followed by a discussion of modelling techniques for PCM-concrete composites and their performance. Finally, a summary and the possible research directions for future work are given. This overview aims to assure the researchers and asset owners of the potential of this maturing technology and bring it one step closer to practical application. PMID:29695076

Smart Crack Control in Concrete through Use of Phase Change Materials (PCMs): A Review.

PubMed

Šavija, Branko

2018-04-24

Cracks in concrete structures present a threat to their durability. Therefore, numerous research studies have been devoted to reducing concrete cracking. In recent years, a new approach has been proposed for controlling temperature related cracking—utilization of phase change materials (PCMs) in concrete. Through their ability to capture heat, PCMs can offset temperature changes and reduce gradients in concrete structures. Nevertheless, they can also influence concrete properties. This paper presents a comprehensive overview of the literature devoted to using PCMs to control temperature related cracking in concrete. First, types of PCMs and ways of incorporation in concrete are discussed. Then, possible uses of PCMs in concrete technology are discussed. Further, the influences of PCMs on concrete properties (fresh, hardened, durability) are discussed in detail. This is followed by a discussion of modelling techniques for PCM-concrete composites and their performance. Finally, a summary and the possible research directions for future work are given. This overview aims to assure the researchers and asset owners of the potential of this maturing technology and bring it one step closer to practical application.

Behaviour of Recycled Coarse Aggregate Concrete: Age and Successive Recycling

NASA Astrophysics Data System (ADS)

Sahoo, Kirtikanta; Pathappilly, Robin Davis; Sarkar, Pradip

2016-06-01

Recycled Coarse Aggregate (RCA) concrete construction technique can be called as `green concrete', as it minimizes the environmental hazard of the concrete waste disposal. Indian standard recommends target mean compressive strength of the conventional concrete in terms of water cement ratio ( w/ c). The present work is an attempt to study the behaviour of RCA concrete from two samples of parent concrete having different age group with regard to the relationship of compressive strength with water cement ratios. Number of recycling may influence the mechanical properties of RCA concrete. The influence of age and successive recycling on the properties such as capillary water absorption, drying shrinkage strain, air content, flexural strength and tensile splitting strength of the RCA concrete are examined. The relationship between compressive strength at different w/ c ratios obtained experimentally is investigated for the two parameters such as age of parent concrete and successive recycling. The recycled concrete using older recycled aggregate shows poor quality. While the compressive strength reduces with successive recycling gradually, the capillary water absorption increases abruptly, which leads to the conclusion that further recycling may not be advisable.

Effect of concrete strength gradation to the compressive strength of graded concrete, a numerical approach

NASA Astrophysics Data System (ADS)

Pratama, M. Mirza Abdillah; Aylie, Han; Gan, Buntara Sthenly; Umniati, B. Sri; Risdanareni, Puput; Fauziyah, Shifa

2017-09-01

Concrete casting, compacting method, and characteristic of the concrete material determine the performance of concrete as building element due to the material uniformity issue. Previous studies show that gradation in strength exists on building member by nature and negatively influence the load carrying capacity of the member. A pilot research had modeled the concrete gradation in strength with controllable variable and observed that the weakest material determines the strength of graded concrete through uniaxial compressive loading test. This research intends to confirm the recent finding by a numerical approach with extensive variables of strength disparity. The finite element analysis was conducted using the Strand7 nonlinear program. The results displayed that the increase of strength disparity in graded concrete models leads to the slight reduction of models strength. A substantial difference in displacement response is encountered on the models for the small disparity of concrete strength. However, the higher strength of concrete mix in the graded concrete models contributes to the rise of material stiffness that provides a beneficial purpose for serviceability of building members.

Utilization of sugarcane bagasse ash in concrete as partial replacement of cement

NASA Astrophysics Data System (ADS)

Mangi, Sajjad Ali; Jamaluddin, N.; Ibrahim, M. H. Wan; Halid Abdullah, Abd; Awal, A. S. M. Abdul; Sohu, Samiullah; Ali, Nizakat

2017-11-01

This research addresses the suitability of sugarcane bagasse ash (SCBA) in concrete used as partial cement replacement. Two grades of concrete M15 and M20 were used for the experimental analysis. The cement was partially replaced by SCBA at 0%, 5%, and 10%, by weight in normal strength concrete (NSC). The innovative part of this study is to consider two grades of concrete mixes to evaluate the performance of concrete while cement is replaced by sugarcane bagasse ash. The cylindrical specimens having size 150 mm × 300 mm were used and tested after curing period of 7, 14 and 28 days. It was observed through the experimental work that the compressive strength increases with incorporating SCBA in concrete. Results indicated that the use of SCBA in concrete (M20) at 5% increased the average amount of compressive strength by 12% as compared to the normal strength concrete. The outcome of this work indicates that maximum strength of concrete could be attained at 5% replacement of cement with SCBA. Furthermore, the SCBA also gives compatible slump values which increase the workability of concrete.

Mechanical Properties and Eco-Efficiency of Steel Fiber Reinforced Alkali-Activated Slag Concrete

PubMed Central

Kim, Sun-Woo; Jang, Seok-Joon; Kang, Dae-Hyun; Ahn, Kyung-Lim; Yun, Hyun-Do

2015-01-01

Conventional concrete production that uses ordinary Portland cement (OPC) as a binder seems unsustainable due to its high energy consumption, natural resource exhaustion and huge carbon dioxide (CO2) emissions. To transform the conventional process of concrete production to a more sustainable process, the replacement of high energy-consumptive PC with new binders such as fly ash and alkali-activated slag (AAS) from available industrial by-products has been recognized as an alternative. This paper investigates the effect of curing conditions and steel fiber inclusion on the compressive and flexural performance of AAS concrete with a specified compressive strength of 40 MPa to evaluate the feasibility of AAS concrete as an alternative to normal concrete for CO2 emission reduction in the concrete industry. Their performances are compared with reference concrete produced using OPC. The eco-efficiency of AAS use for concrete production was also evaluated by binder intensity and CO2 intensity based on the test results and literature data. Test results show that it is possible to produce AAS concrete with compressive and flexural performances comparable to conventional concrete. Wet-curing and steel fiber inclusion improve the mechanical performance of AAS concrete. Also, the utilization of AAS as a sustainable binder can lead to significant CO2 emissions reduction and resources and energy conservation in the concrete industry. PMID:28793639

An Exploratory Compressive Strength Of Concrete Containing Modified Artificial Polyethylene Aggregate (MAPEA)

NASA Astrophysics Data System (ADS)

Hadipramana, J.; Mokhatar, S. N.; Samad, A. A. A.; Hakim, N. F. A.

2016-11-01

Concrete is widely used in the world as building and construction material. However, the constituent materials used in concrete are high cost when associated with the global economic recession. This exploratory aspires to have an alternative source of replacing natural aggregate with plastic wastes. An investigation of the Modified Artificial Polyethylene Aggregate (MAPEA) as natural aggregate replacement in concrete through an experimental work was conducted in this study. The MAPEA was created to improve the bonding ability of Artificial Polyethylene Aggregate (APEA) with the cement paste. The concrete was mixed with 3%, 6%, 9%, and 12% of APEA and MAPEA for 14 and 28 curing days, respectively. Furthermore, the compressive strength test was conducted to find out the optimum composition of MAPEA in concrete and compared to the APEA concrete. Besides, this study observed the influence and behaviour of MAPEA in concrete. Therefore, the Scanning Electron Microscopy was applied to observe the microstructure of MAPEA and APEA concrete. The results showed the use of high composition of an artificial aggregate resulted inferior strength on the concrete and 3% MAPEA in the concrete mix was highest compressive strength than other content. The modification of APEA (MAPEA) concrete increased its strength due to its surface roughness. However, the interfacial zone cracking was still found and decreased the strength of MAPEA concrete especially when it was age 28 days.

Concrete pavement quality control testing requirements needed for the super air meter : final report.

DOT National Transportation Integrated Search

2016-10-01

Concrete freeze-thaw durability is prominently linked to the air void system within the concrete. : Concrete pavements in Kansas undergo repetitive freeze-thaw cycles. Total air content measurements : currently used on fresh concrete do not provide a...

Concrete pavement quality control testing requirements needed for the super air meter : technical summary.

DOT National Transportation Integrated Search

2016-10-01

Concrete freeze-thaw durability is prominently linked to the air void system : within the concrete. Concrete pavements in Kansas undergo repetitive : freeze-thaw cycles. Total air content measurements currently used on fresh : concrete do not provide...

Use of fiber reinforced concrete for concrete pavement slab replacement.

DOT National Transportation Integrated Search

2014-03-01

Unlike ordinary concrete pavement, replacement concrete slabs need to be open to traffic within 24 hours (sooner in : some cases). Thus, high early-strength concrete is used; however, it frequently cracks prematurely as a result of high : heat of hyd...

Best practices for concrete pumping : technical summary.

DOT National Transportation Integrated Search

2016-12-01

Pumping is one of the major placement techniques used in the concrete industry : to deliver concrete from the mixing truck to the formwork. Although concrete : pumping has been used to place concrete since the 1960s, there is still a lack : of exact ...

Learning style and teaching method preferences of Saudi students of physical therapy

PubMed Central

Al Maghraby, Mohamed A.; Alshami, Ali M.

2013-01-01

Context: To the researchers’ knowledge, there are no published studies that have investigated the learning styles and preferred teaching methods of physical therapy students in Saudi Arabia. Aim: The study was conducted to determine the learning styles and preferred teaching methods of Saudi physical therapy students. Settings and Design: A cross-sectional study design. Materials and Methods: Fifty-three Saudis studying physical therapy (21 males and 32 females) participated in the study. The principal researcher gave an introductory lecture to explain the different learning styles and common teaching methods. Upon completion of the lecture, questionnaires were distributed, and were collected on completion. Statistical Analysis Used: Percentages were calculated for the learning styles and teaching methods. Pearson’s correlations were performed to investigate the relationship between them. Results: More than 45 (85%) of the students rated hands-on training as the most preferred teaching method. Approximately 30 (57%) students rated the following teaching methods as the most preferred methods: “Advanced organizers,” “demonstrations,” and “multimedia activities.” Although 31 (59%) students rated the concrete-sequential learning style the most preferred, these students demonstrated mixed styles on the other style dimensions: Abstract-sequential, abstract-random, and concrete-random. Conclusions: The predominant concrete-sequential learning style is consistent with the most preferred teaching method (hands-on training). The high percentage of physical therapy students whose responses were indicative of mixed learning styles suggests that they can accommodate multiple teaching methods. It is recommended that educators consider the diverse learning styles of the students and utilize a variety of teaching methods in order to promote an optimal learning environment for the students. PMID:24672278

Simplified equation for Young's modulus of CNT reinforced concrete

NASA Astrophysics Data System (ADS)

Chandran, RameshBabu; Gifty Honeyta A, Maria

2017-12-01

This research investigation focuses on finite element modeling of carbon nanotube (CNT) reinforced concrete matrix for three grades of concrete namely M40, M60 and M120. Representative volume element (RVE) was adopted and one-eighth model depicting the CNT reinforced concrete matrix was simulated using FEA software ANSYS17.2. Adopting random orientation of CNTs, with nine fibre volume fractions from 0.1% to 0.9%, finite element modeling simulations replicated exactly the CNT reinforced concrete matrix. Upon evaluations of the model, the longitudinal and transverse Young's modulus of elasticity of the CNT reinforced concrete was arrived. The graphical plots between various fibre volume fractions and the concrete grade revealed simplified equation for estimating the young's modulus. It also exploited the fact that the concrete grade does not have significant impact in CNT reinforced concrete matrix.

Sustainability and durability analysis of reinforced concrete structures

NASA Astrophysics Data System (ADS)

Horáková, A.; Broukalová, I.; Kohoutková, A.; Vašková, J.

2017-09-01

The article describes an assessment of reinforced concrete structures in terms of durability and sustainable development. There is a short summary of findings from the literature on evaluation methods for environmental impacts and also about corrosive influences acting on the reinforced concrete structure, about factors influencing the durability of these structures and mathematical models describing the corrosion impacts. Variant design of reinforced concrete structure and assessment of these variants in terms of durability and sustainability was performed. The analysed structure was a concrete ceiling structure of a parking house for cars. The variants differ in strength class of concrete and thickness of concrete slab. It was found that in terms of durability and sustainable development it is significantly preferable to use higher class of concrete. There are significant differences in results of concrete structures durability for different mathematical models of corrosive influences.

STORM-SEWER FLOW MEASUREMENT AND RECORDING SYSTEM.

USGS Publications Warehouse

Kilpatrick, Frederick A.; Kaehrle, William R.

1986-01-01

A comprehensive study and development of instruments and techniques for measuring all components of flow in a storm-sewer drainage system were undertaken by the U. S. Geological Survey under the sponsorship of FHWA. The study involved laboratory and field calibration and testing of measuring flumes, pipe insert meters, weirs, and electromagnetic velocity meters as well as the development and calibration of pneumatic bubbler and pressure transducer head-measuring systems. Tracer dilution and acoustic-flowmeter measurements were used in field verification tests. A single micrologger was used to record data from all the instruments and also to activate on command the electromagnetic velocity meter and tracer dilution systems.

Ancient Maritime Fish-Traps of Brittany (France): A Reappraisal of the Relationship Between Human and Coastal Environment During the Holocene

NASA Astrophysics Data System (ADS)

Langouët, Loïc; Daire, Marie-Yvane

2009-12-01

The present-day maritime landscape of Western France forms the geographical framework for a recent research project dedicated to the archaeological study of ancient fish-traps, combining regional-scale and site-scale investigations. Based on the compilation and exploitation of a large unpublished dataset including more than 550 sites, a preliminary synthetic study allows us to present some examples of synchronic and thematic approaches, and propose a morphological classification of the weirs. These encouraging first results open up new perspectives on fish-trap chronology closely linked to wider studies on Holocene sea-level changes.

Report of concrete pavement evaluation : project 105 C-4181-01 Donahoo Road, Wyandotte County : [technical summary].

DOT National Transportation Integrated Search

2013-12-01

The physical properties of hardened concrete cores and fresh concrete test results were compared with aggregate gradation workability differences. The concrete cores were taken from a rural two-lane concrete road in northeastern Kansas constructed in...

Evaluation of flyash in lean concrete base and continuously reinforced concrete pavements : final report.

DOT National Transportation Integrated Search

1991-07-01

Proposed research on this project included five main objectives: 1) To test and evaluate the physical characteristics of flyash concrete in comparions to non-flyash concrete. Tests will be conducted to see if flyash concrete meets OSHD specifications...

76 FR 34890 - Track Safety Standards; Concrete Crossties

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-15

...-0007, Notice No. 3] RIN 2130-AC01 Track Safety Standards; Concrete Crossties AGENCY: Federal Railroad... effective concrete crossties, for rail fastening systems connected to concrete crossties, and for automated inspections of track constructed with concrete crossties. The Track Safety Standards were amended via final...

Experimental Study on Impermeability of Recycled Concrete

NASA Astrophysics Data System (ADS)

Wang, Shao Zhen; Yang, Jian Gong; Wei, Lu

2018-06-01

Recycled concrete is a kind of concrete which is constructed by crushing and removing the building waste and concrete blocks and mixing them according to a certain proportion after grading. In this study, the applicability of recycled concrete is studied only in terms of impermeability.

Microstructural and Microanalytical Study on Concrete Exposed to the Sulfate Environment

NASA Astrophysics Data System (ADS)

Qing, Fang; Beixing, Li; Jiangang, Yin; Xiaolu, Yuan

2017-11-01

Microstructural properties have been examined to investigate the effect of mineral admixtures on the sulfate resistance of concrete. Concrete and cement paste specimens made with ordinary Portland cement (OPC) or ordinary Portland cement incorporating 20% fly ash (FA) or 30% ground blast furnace slag (GBFS), were made and exposed to 250 cycles of the cyclic sulfate environment. Microstructural and Microanalytical study was conducted by means of x-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and mercury intrusion porosimetry (MIP). Results indicate that the pore structure of concrete after sulfate exposure possesses the fractal feature. The OPC concrete presents more complex pore internal surface, higher porosity and less micro-pores than the concrete incorporating fly ash and GBFS. Portlandite in OPC concrete and OPC-FA concrete is mainly converted to gypsum; while for OPC-GBFS concrete, both gypsum and ettringite are formed. In the cyclic sulfate environment, repeated hydration and dehydration of sulfates produce the expansive stress in pores, aggravating the demolishment of concrete structure.

Optimizing the use of natural gravel Brantas river as normal concrete mixed with quality fc = 19.3 Mpa

NASA Astrophysics Data System (ADS)

Limantara, A. D.; Widodo, A.; Winarto, S.; Krisnawati, L. D.; Mudjanarko, S. W.

2018-04-01

The use of natural gravel (rivers) as concrete mixtures is rarely encountered after days of demands for a higher strength of concrete. Moreover, today people have found High-Performance Concrete which, when viewed from the rough aggregate consisted mostly of broken stone, although the fine grain material still used natural sand. Is it possible that a mixture of concrete using natural gravel as a coarse aggregate is capable of producing concrete with compressive strength equivalent to a concrete mixture using crushed stone? To obtain information on this, a series of tests on concrete mixes with crude aggregates of Kalitelu Crusher, Gondang, Tulungagung and natural stone (river gravel) from the Brantas River, Ngujang, Tulungagung in the Materials Testing Laboratory Tugu Dam Construction Project, Kab. Trenggalek. From concrete strength test results using coarse material obtained value 19.47 Mpa, while the compressive strength of concrete with a mixture of crushed stone obtained the value of 21.12 Mpa.

Mechanical properties of recycled concrete with demolished waste concrete aggregate and clay brick aggregate

NASA Astrophysics Data System (ADS)

Zheng, Chaocan; Lou, Cong; Du, Geng; Li, Xiaozhen; Liu, Zhiwu; Li, Liqin

2018-06-01

This paper presents an experimental investigation on the effect of the replacement of natural coarse aggregate (NCA) with either recycled concrete aggregate (RCA) or recycled clay brick aggregate (RBA) on the compressive strengths of the hardened concrete. Two grades (C25 and C50) of concrete were investigated, which were achieved by using different water-to-cement ratios. In each grade concrete five different replacement rates, 0%, 25%, 50%, 75% and 100% were considered. In order to improve the performance of the recycled aggregates in the concrete mixes, the RCA and RBA were carefully sieved by using the optimal degradation. In this way the largest reduction in the 28-day compressive strength was found to be only 7.2% and 9.6% for C25 and C50 recycled concrete when the NCA was replaced 100% by RCA, and 11% and 13% for C25 and C50 recycled concrete when the NCA was replaced 100% by RBA. In general, the concrete with RCA has better performance than the concrete with RBA. The comparison of the present experimental results with those reported in literature for hardened concrete with either RCA or RBA demonstrates the effectiveness in improving the compressive strength by using the optimal gradation of recycled aggregates.

A review of recent developments in parametric based acoustic emission techniques applied to concrete structures

NASA Astrophysics Data System (ADS)

Vidya Sagar, R.; Raghu Prasad, B. K.

2012-03-01

This article presents a review of recent developments in parametric based acoustic emission (AE) techniques applied to concrete structures. It recapitulates the significant milestones achieved by previous researchers including various methods and models developed in AE testing of concrete structures. The aim is to provide an overview of the specific features of parametric based AE techniques of concrete structures carried out over the years. Emphasis is given to traditional parameter-based AE techniques applied to concrete structures. A significant amount of research on AE techniques applied to concrete structures has already been published and considerable attention has been given to those publications. Some recent studies such as AE energy analysis and b-value analysis used to assess damage of concrete bridge beams have also been discussed. The formation of fracture process zone and the AE energy released during the fracture process in concrete beam specimens have been summarised. A large body of experimental data on AE characteristics of concrete has accumulated over the last three decades. This review of parametric based AE techniques applied to concrete structures may be helpful to the concerned researchers and engineers to better understand the failure mechanism of concrete and evolve more useful methods and approaches for diagnostic inspection of structural elements and failure prediction/prevention of concrete structures.

Physical Characteristics of Laboratory Tested Concrete as a Substituion of Gravel on Normal Concrete

NASA Astrophysics Data System (ADS)

Butar-butar, Ronald; Suhairiani; Wijaya, Kinanti; Sebayang, Nono

2018-03-01

Concrete technology is highly potential in the field of construction for structural and non-structural construction. The amount uses of this concrete material raise the problem of solid waste in the form of concrete remaining test results in the laboratory. This waste is usually just discarded and not economically valuable. In solving the problem, this experiment was made new materials by using recycle material in the form of recycled aggregate which aims to find out the strength characteristics of the used concrete as a gravel substitution material on the normal concrete and obtain the value of the substitution composition of gravel and used concrete that can achieve the strength of concrete according to the standard. Testing of concrete characteristic is one of the requirements before starting the concrete mixture. This test using SNI method (Indonesian National Standard) with variation of comparison (used concrete : gravel) were 15: 85%, 25: 75%, 35:65%, 50:50 %, 75: 25%. The results of physical tests obtained the mud content value of the mixture gravel and used concrete is 0.03 larger than the standard of SNI 03-4142-1996 that is equal to 1.03%. so the need watering or soaking before use. The water content test results show an increase in the water content value if the composition of the used concrete increases. While the specific gravity value for variation 15: 85% until 35: 65% fulfilled the requirements of SNI 03-1969-1990. the other variasion show the specifics gravity value included on the type of light materials.

29 CFR 1926.704 - Requirements for precast concrete.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 8 2010-07-01 2010-07-01 false Requirements for precast concrete. 1926.704 Section 1926..., DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Concrete and Masonry Construction § 1926.704 Requirements for precast concrete. (a) Precast concrete wall units, structural framing...

Report E : self-consolidating concrete (SCC) for infrastructure elements - hardened mechanical properties and durability performance.

DOT National Transportation Integrated Search

2012-08-01

Concrete is one of the most produced and utilized materials in the world. Due to : the labor intensive and time consuming nature of concrete construction, new and : innovative concrete mixes are being explored. Self-consolidating concrete (SCC) is on...

Design and evaluation of high-volume fly ash (HVFA) concrete mixes, report C : shear behavior of HVFA reinforced concrete.

DOT National Transportation Integrated Search

2012-10-01

Concrete is the most widely used man-made material on the planet. Unfortunately, producing Portland cement generates carbon dioxide (a greenhouse gas) at roughly a pound for pound ratio. High-volume fly ash (HVFA) concrete concrete with at least ...

Development of design parameters for mass concrete using finite element analysis : final report, February 2010.

DOT National Transportation Integrated Search

2010-02-01

A finite element model for analysis of mass concrete was developed in this study. To validate the developed model, large concrete blocks made with four different mixes of concrete, typical of use in mass concrete applications in Florida, were made an...

Nuclear reactor containment structure with continuous ring tunnel at grade

DOEpatents

Seidensticker, Ralph W.; Knawa, Robert L.; Cerutti, Bernard C.; Snyder, Charles R.; Husen, William C.; Coyer, Robert G.

1977-01-01

A nuclear reactor containment structure which includes a reinforced concrete shell, a hemispherical top dome, a steel liner, and a reinforced-concrete base slab supporting the concrete shell is constructed with a substantial proportion thereof below grade in an excavation made in solid rock with the concrete poured in contact with the rock and also includes a continuous, hollow, reinforced-concrete ring tunnel surrounding the concrete shell with its top at grade level, with one wall integral with the reinforced concrete shell, and with at least the base of the ring tunnel poured in contact with the rock.

Effect of mineral additives on structure and properties of concrete for pavements

NASA Astrophysics Data System (ADS)

Sobol, Khrystyna; Markiv, Taras; Hunyak, Oleksii

2017-12-01

Concrete pavements is an attractive alternative to asphalt pavements because of its lower cost and higher durability. Major contribution to sustainable development can be made by partial replacement of cement in concrete pavement with supplementary cementitious materials of different nature and origin. In this paper, the effect of natural zeolite and perlite additives in complex with chemical admixtures on the structure and properties of concrete for pavement was studied. Compressive and flexural strength test was used to study the mechanical behavior of designed concrete under load. Generally, the compressive strength of both control concrete and concrete containing mineral additives levels at the later ages of hardening. The microstructure analysis of concrete with mineral additives of different nature activity showed the formation of additional amount of hydration products such as tobermorite type calcium hydrosilicate which provide self-reinforcement of hardening concrete system.

Corrosion Propagation of Rebar Embedded in High Performance Concrete

NASA Astrophysics Data System (ADS)

Nazim, Manzurul

The FDOT has been using supplementary cementitious materials while constructing steel reinforced concrete marine bridge structures for over 3 decades. Previous findings indicated that such additions in concrete mix make the concrete more durable. To better understand corrosion propagation of rebar in high performance concrete: mature concrete samples that were made (2008/2009) with Portland cement, a binary mix, a ternary mix and recently prepared (April 2016 with 50% OPC + 50% slag and 80% OPC + 20% Fly ash) concrete samples were considered. None of these concretes had any admixed chloride to start with. An accelerated chloride transport process was used to drive chloride ions into the concrete so that chlorides reach and exceed the chloride threshold at the rebar surface and initiate corrosion. Electrochemical measurements were taken at regular intervals (during and after the electro-migration process) to observe the corrosion propagation in each sample.

Strength of masonry blocks made with recycled concrete aggregates

NASA Astrophysics Data System (ADS)

Matar, Pierre; Dalati, Rouba El

The idea of recycling concrete of demolished buildings aims at preserving the environment. Indeed, the reuse of concrete as aggregate in new concrete mixes helped to reduce the expenses related to construction and demolition (C&D) waste management and, especially, to protect the environment by reducing the development rate of new quarries. This paper presents the results of an experimental study conducted on masonry blocks containing aggregates resulting from concrete recycling. The purpose of this study is to investigate the effect of recycled aggregates on compressive strength of concrete blocks. Tests were performed on series of concrete blocks: five series each made of different proportions of recycled aggregates, and one series of reference blocks exclusively composed of natural aggregates. Tests showed that using recycled aggregates with addition of cement allows the production of concrete blocks with compressive strengths comparable to those obtained on concrete blocks made exclusively of natural aggregates.

Binary effect of fly ash and palm oil fuel ash on heat of hydration aerated concrete.

PubMed

Mehmannavaz, Taha; Ismail, Mohammad; Radin Sumadi, Salihuddin; Rafique Bhutta, Muhammad Aamer; Samadi, Mostafa; Sajjadi, Seyed Mahdi

2014-01-01

The binary effect of pulverized fuel ash (PFA) and palm oil fuel ash (POFA) on heat of hydration of aerated concrete was studied. Three aerated concrete mixes were prepared, namely, concrete containing 100% ordinary Portland cement (control sample or Type I), binary concrete made from 50% POFA (Type II), and ternary concrete containing 30% POFA and 20% PFA (Type III). It is found that the temperature increases due to heat of hydration through all the concrete specimens especially in the control sample. However, the total temperature rises caused by the heat of hydration through both of the new binary and ternary concrete were significantly lower than the control sample. The obtained results reveal that the replacement of Portland cement with binary and ternary materials is beneficial, particularly for mass concrete where thermal cracking due to extreme heat rise is of great concern.

Binary Effect of Fly Ash and Palm Oil Fuel Ash on Heat of Hydration Aerated Concrete

PubMed Central

Mehmannavaz, Taha; Ismail, Mohammad; Radin Sumadi, Salihuddin; Rafique Bhutta, Muhammad Aamer; Samadi, Mostafa

2014-01-01

The binary effect of pulverized fuel ash (PFA) and palm oil fuel ash (POFA) on heat of hydration of aerated concrete was studied. Three aerated concrete mixes were prepared, namely, concrete containing 100% ordinary Portland cement (control sample or Type I), binary concrete made from 50% POFA (Type II), and ternary concrete containing 30% POFA and 20% PFA (Type III). It is found that the temperature increases due to heat of hydration through all the concrete specimens especially in the control sample. However, the total temperature rises caused by the heat of hydration through both of the new binary and ternary concrete were significantly lower than the control sample. The obtained results reveal that the replacement of Portland cement with binary and ternary materials is beneficial, particularly for mass concrete where thermal cracking due to extreme heat rise is of great concern. PMID:24696646

CF60 Concrete Composition Design and Application on Fudiankou Xijiang Super Large Bridge

NASA Astrophysics Data System (ADS)

Qiu, Yi Mei; Wen, Sen Yuan; Chen, Jun Xiang

2018-06-01

Guangxi Wuzhou City Ring Road Fudiankou Xijiang super large bridge CF60 concrete is a new multi-phase composite high-performance concrete, this paper for the Fudiankou Xijiang bridge structure and characteristics of the project, in accordance with the principle of local materials and technical specification requirements, combined with the site conditions of CF60 engineering high performance concrete component materials, proportion and the technical performance, quantify the main physical and mechanical performance index. Analysis main influencing factors of the technical indicators, reasonable adjustment of concrete mix design parameters, and the use of technical means of admixture and multi-function composite admixture of concrete, obtain the optimal proportion of good work, process, mechanical properties stability and durability of engineering properties, recommend and verification of concrete mix; to explore the CF60 high performance concrete Soil in the Fudiankou Xijiang bridge application technology, detection and tracking the quality of concrete construction, concrete structure during the construction of the key technology and control points is proposed, evaluation of CF60 high performance concrete in the actual engineering application effect and benefit to ensure engineering quality of bridge structure and service life, and super long span bridge engineering construction to provide basis and reference.

Experimental Investigation of the Mechanical and Durability Properties of Crumb Rubber Concrete.

PubMed

Liu, Hanbing; Wang, Xianqiang; Jiao, Yubo; Sha, Tao

2016-03-07

Recycling waste tire rubber by incorporating it into concrete has become the preferred solution to dispose of waste tires. In this study, the effect of the volume content of crumb rubber and pretreatment methods on the performances of concrete was evaluated. Firstly, the fine aggregate and mixture were partly replaced by crumb rubber to produce crumb rubber concrete. Secondly, the mechanical and durability properties of crumb rubber concrete with different replacement forms and volume contents had been investigated. Finally, the crumb rubber after pretreatment by six modifiers was introduced into the concrete mixture. Corresponding tests were conducted to verify the effectiveness of pretreatment methods as compared to the concrete containing untreated crumb rubber. It was observed that the mechanical strength of crumb rubber concrete was reduced, while durability was improved with the increasing of crumb rubber content. 20% replacement of fine aggregate and 5% replacement of the total mixture exhibited acceptable properties for practical applications. In addition, the results indicated that the modifiers had a positive impact on the mechanical and durability properties of crumb rubber concrete. It avoided the disadvantage of crumb rubber concrete having lower strength and provides a reference for the production of modified crumb rubber concrete.

Development of Vegetation-Pervious Concrete in Grid Beam System for Soil Slope Protection.

PubMed

Bao, Xiaohua; Liao, Wenyu; Dong, Zhijun; Wang, Shanyong; Tang, Waiching

2017-01-24

One of the most efficient and environmentally friendly methods for preventing a landslide on a slope is to vegetate it. Vegetation-pervious concretes have a promising potential for soil protection. In this study, the vegetation-pervious concrete with low alkalinity was developed and studied. Combined with a grid beam structure system, the stability and strength between the vegetation-pervious concrete and base soil are believed to be enhanced effectively. For improving plant adaptability, the alkalinity of concrete can be decreased innovatively by adding a self-designed admixture into the cement paste. The effects of the admixture content on alkalinity and compressive strength of the hardened pervious concrete were investigated using X-ray diffraction (XRD) and compression test, respectively. Meanwhile, the permeability of the vegetation-pervious concrete was studied as well. Through comparing with ordinary pervious concrete, the effect of low alkaline pervious concrete on vegetation growth was investigated in a small-scale field for ten weeks. The test results indicated that the alkalinity of the cement samples decreased with the increase of admixture content, and the vegetation grew successfully on previous concrete. By increasing the admixture content to approximately 3.6%, the compressive strength of pervious concrete was more than 25 MPa.

Active hematite concretion formation in modern acid saline lake sediments, Lake Brown, Western Australia

NASA Astrophysics Data System (ADS)

Bowen, Brenda Beitler; Benison, K. C.; Oboh-Ikuenobe, F. E.; Story, S.; Mormile, M. R.

2008-04-01

Concretions can provide valuable records of diagenesis and fluid-sediment interactions, however, reconstruction of ancient concretion-forming conditions can be difficult. Observation of modern hematite concretion growth in a natural sedimentary setting provides a rare glimpse of conditions at the time of formation. Spheroidal hematite-cemented concretions are actively precipitating in shallow subsurface sediments at Lake Brown in Western Australia. Lake Brown is a hypersaline (total dissolved solids up to 23%) and acidic (pH ˜ 4) ephemeral lake. The concretion host sediments were deposited between ˜ 1 and 3 ka, based on dating of stratigraphically higher and lower beds. These age constraints indicate that the diagenetic concretions formed < 3 ka, and field observations suggest that some are currently forming. These modern concretions from Lake Brown provide an example of very early diagenetic formation in acid and saline conditions that may be analogous to past conditions on Mars. Previously, the hematite concretions in the Burns formation on Mars have been interpreted as late stage diagenetic products, requiring long geologic time scales and multiple fluid flow events to form. In contrast, the Lake Brown concretions support the possibility of similar syndepositional to very early diagenetic concretion precipitation on Mars.

Experimental Investigation of the Mechanical and Durability Properties of Crumb Rubber Concrete

PubMed Central

Liu, Hanbing; Wang, Xianqiang; Jiao, Yubo; Sha, Tao

2016-01-01

Recycling waste tire rubber by incorporating it into concrete has become the preferred solution to dispose of waste tires. In this study, the effect of the volume content of crumb rubber and pretreatment methods on the performances of concrete was evaluated. Firstly, the fine aggregate and mixture were partly replaced by crumb rubber to produce crumb rubber concrete. Secondly, the mechanical and durability properties of crumb rubber concrete with different replacement forms and volume contents had been investigated. Finally, the crumb rubber after pretreatment by six modifiers was introduced into the concrete mixture. Corresponding tests were conducted to verify the effectiveness of pretreatment methods as compared to the concrete containing untreated crumb rubber. It was observed that the mechanical strength of crumb rubber concrete was reduced, while durability was improved with the increasing of crumb rubber content. 20% replacement of fine aggregate and 5% replacement of the total mixture exhibited acceptable properties for practical applications. In addition, the results indicated that the modifiers had a positive impact on the mechanical and durability properties of crumb rubber concrete. It avoided the disadvantage of crumb rubber concrete having lower strength and provides a reference for the production of modified crumb rubber concrete. PMID:28773298

Properties of concrete containing different type of waste materials as aggregate replacement exposed to elevated temperature – A review

NASA Astrophysics Data System (ADS)

Ghadzali, N. S.; Ibrahim, M. H. W.; Sani, M. S. H. Mohd; Jamaludin, N.; Desa, M. S. M.; Misri, Z.

2018-04-01

Concrete is the chief material of construction and it is non-combustible in nature. However, the exposure to the high temperature such as fire can lead to change in the concrete properties. Due to the higher temperature, several changes in terms of mechanical properties were observed in concrete such as compressive strength, modulus of elasticity, tensile strength and durability of concrete will decrease significantly at high temperature. The exceptional fire-proof achievement of concrete is might be due to the constituent materials of concrete such as its aggregates. The extensive use of aggregate in concrete will leads to depletion of natural resources. Hence, the use of waste and other recycled and by-product material as aggregates replacements becomes a leading research. This review has been made on the utilization of waste materials in concrete and critically evaluates its effects on the concrete performances during the fire exposure. Therefore, the objective of this paper is to review the previous search work regarding the concrete containing waste material as aggregates replacement when exposed to elevated temperature and come up with different design recommendations to improve the fire resistance of structures.

Statistical and Detailed Analysis on Fiber Reinforced Self-Compacting Concrete Containing Admixtures- A State of Art of Review

NASA Astrophysics Data System (ADS)

Athiyamaan, V.; Mohan Ganesh, G.

2017-11-01

Self-Compacting Concrete is one of the special concretes that have ability to flow and consolidate on its own weight, completely fill the formwork even in the presence of dense reinforcement; whilst maintaining its homogeneity throughout the formwork without any requirement for vibration. Researchers all over the world are developing high performance concrete by adding various Fibers, admixtures in different proportions. Various different kinds Fibers like glass, steel, carbon, Poly propylene and aramid Fibers provide improvement in concrete properties like tensile strength, fatigue characteristic, durability, shrinkage, impact, erosion resistance and serviceability of concrete[6]. It includes fundamental study on fiber reinforced self-compacting concrete with admixtures; its rheological properties, mechanical properties and overview study on design methodology statistical approaches regarding optimizing the concrete performances. The study has been classified into seven basic chapters: introduction, phenomenal study on material properties review on self-compacting concrete, overview on fiber reinforced self-compacting concrete containing admixtures, review on design and analysis of experiment; a statistical approach, summary of existing works on FRSCC and statistical modeling, literature review and, conclusion. It is so eminent to know the resent studies that had been done on polymer based binder materials (fly ash, metakaolin, GGBS, etc.), fiber reinforced concrete and SCC; to do an effective research on fiber reinforced self-compacting concrete containing admixtures. The key aim of the study is to sort-out the research gap and to gain a complete knowledge on polymer based Self compacting fiber reinforced concrete.

Cross-cultural comparison of concrete recycling decision-making and implementation in construction industry.

PubMed

Tam, Vivian W Y; Tam, Leona; Le, Khoa N

2010-02-01

Waste management is pressing very hard with alarming signals in construction industry. Concrete waste constituents major proportions of construction and demolition waste of 81% in Australia. To minimize concrete waste generated from construction activities, recycling concrete waste is one of the best methods to conserve the environment. This paper investigates concrete recycling implementation in construction. Japan is a leading country in recycling concrete waste, which has been implementing 98% recycling and using it for structural concrete applications. Hong Kong is developing concrete recycling programs for high-grade applications. Australia is making relatively slow progress in implementing concrete recycling in construction. Therefore, empirical studies in Australia, Hong Kong, and Japan were selected in this paper. A questionnaire survey and structured interviews were conducted. Power spectrum was used for analysis. It was found that "increasing overall business competitiveness and strategic business opportunities" was considered as the major benefit for concrete recycling from Hong Kong and Japanese respondents, while "rising concrete recycling awareness such as selecting suitable resources, techniques and training and compliance with regulations" was considered as the major benefit from Australian respondents. However, "lack of clients' support", "increase in management cost" and "increase in documentation workload, such as working documents, procedures and tools" were the major difficulties encountered from Australian, Hong Kong, and Japanese respondents, respectively. To improve the existing implementation, "inclusion of concrete recycling evaluation in tender appraisal" and "defining clear legal evaluation of concrete recycling" were major recommendations for Australian and Hong Kong, and Japanese respondents, respectively.

Comparative testing of nondestructive examination techniques for concrete structures

NASA Astrophysics Data System (ADS)

Clayton, Dwight A.; Smith, Cyrus M.

2014-03-01

A multitude of concrete-based structures are typically part of a light water reactor (LWR) plant to provide foundation, support, shielding, and containment functions. Concrete has been used in the construction of nuclear power plants (NPPs) because of three primary properties, its inexpensiveness, its structural strength, and its ability to shield radiation. Examples of concrete structures important to the safety of LWR plants include containment building, spent fuel pool, and cooling towers. Comparative testing of the various NDE concrete measurement techniques requires concrete samples with known material properties, voids, internal microstructure flaws, and reinforcement locations. These samples can be artificially created under laboratory conditions where the various properties can be controlled. Other than NPPs, there are not many applications where critical concrete structures are as thick and reinforced. Therefore, there are not many industries other than the nuclear power plant or power plant industry that are interested in performing NDE on thick and reinforced concrete structures. This leads to the lack of readily available samples of thick and heavily reinforced concrete for performing NDE evaluations, research, and training. The industry that typically performs the most NDE on concrete structures is the bridge and roadway industry. While bridge and roadway structures are thinner and less reinforced, they have a good base of NDE research to support their field NDE programs to detect, identify, and repair concrete failures. This paper will summarize the initial comparative testing of two concrete samples with an emphasis on how these techniques could perform on NPP concrete structures.

Department of the Navy. FY 1994/FY 1995 Biennial Budget Estimates. Military Construction Program. FY 1994

DTIC Science & Technology

1992-01-01

3 are severely deteriorated. The concrete deck and supporting wood -pile structure are nearing the end of their life cycle. Both piers are to be...PROPOSED CONSTRUCTION One-story building with concrete foundation walls, load bearing masonry walls, and concrete floors; roof with wood truss framing...concrete building addition; concrete foundation and slab on grade; wood truss roof; 750 KVA. 3 phase transformer; utilities; concrete and storm drain. 11

On Deterioration Mechanism of Concrete Exposed to Freeze-Thaw Cycles

NASA Astrophysics Data System (ADS)

Trofimov, B. Ya; Kramar, L. Ya; Schuldyakov, K. V.

2017-11-01

At present, concrete and reinforced concrete are gaining ground in all sectors of construction including construction in the extreme north, on shelves, etc. Under harsh service conditions, the durability of reinforced concrete structures is related to concrete frost resistance. Frost resistance tests are accompanied by the accumulation of residual dilation deformations affected by temperature-humidity stresses, ice formation and other factors. Porosity is an integral part of the concrete structure which is formed as a result of cement hydration. The prevailing hypothesis of a deterioration mechanism of concrete exposed to cyclic freezing, i.e. the hypothesis of hydraulic pressure of unfrozen water in microcapillaries, does not take into account a number of phenomena that affect concrete resistance to frost aggression. The main structural element of concrete, i.e. hardened cement paste, contains various hydration products, such as crystalline, semicrystalline and gel-like products, pores and non-hydrated residues of clinker nodules. These structural elements in service can gain thermodynamic stability which leads to the concrete structure coarsening, decrease in the relaxation capacity of concrete when exposed to cycling. Additional destructive factors are leaching of portlandite, the difference in thermal dilation coefficients of hydration products, non-hydrated relicts, aggregates and ice. The main way to increase concrete frost resistance is to reduce the macrocapillary porosity of hardened cement paste and to form stable gel-like hydration products.

The Fire Resistance Performance of Recycled Aggregate Concrete Columns with Different Concrete Compressive Strengths.

PubMed

Dong, Hongying; Cao, Wanlin; Bian, Jianhui; Zhang, Jianwei

2014-12-08

In order to ascertain the fire resistance performance of recycled aggregate concrete (RAC) components with different concrete compressive strengths, four full-scaled concrete columns were designed and tested under high temperature. Two of the four specimens were constructed by normal concrete with compressive strength ratings of C20 and C30, respectively, while the others were made from recycled coarse aggregate (RCA) concrete of C30 and C40, respectively. Identical constant axial forces were applied to specimens while being subjected to simulated building fire conditions in a laboratory furnace. Several parameters from the experimental results were comparatively analyzed, including the temperature change, vertical displacement, lateral deflection, fire endurance, and failure characteristics of specimens. The temperature field of specimens was simulated with ABAQUS Software (ABAQUS Inc., Provindence, RI, USA) and the results agreed quite well with those from the experiments. Results show that the rate of heat transfer from the surface to the interior of the column increases with the increase of the concrete's compressive strength for both RAC columns and normal concrete columns. Under the same initial axial force ratio, for columns with the same cross section, those with lower concrete compressive strengths demonstrate better fire resistance performance. The fire resistance performance of RAC columns is better than that of normal concrete columns, with the same concrete compressive strength.

Study on Mechanical Properties of Concrete Using Plastic Waste as an Aggregate

NASA Astrophysics Data System (ADS)

Jaivignesh, B.; Sofi, A.

2017-07-01

Disposal of large quantity of plastic causes land, water and air pollution etc.., so a study is conducted to recycle the plastic in concrete. This work investigates about the replacement of natural aggregate with non-biodegradable plastic aggregate made up of mixed plastic waste in concrete. Several tests are conducted such as compressive strength of cube, split tensile strength of cylinder, flexural strength test of prism to identify the properties and behavior of concrete using plastic aggregate. Replacement of fine aggregate weight by 10%, 15%, 20% with Plastic fine (PF) aggregate and for each replacement of fine aggregate 15%, 20%, 25% of coarse aggregate replacement also conducted with Plastic Coarse(PC) aggregate. In literatures reported that the addition of plastic aggregate in concrete causes the reduction of strength in concrete due to poor bonding between concrete and plastic aggregate, so addition of 0.3% of steel fiber by weight of cement in concrete is done to improve the concrete strength. Totally 60 cubes, 60 cylinders and 40 prisms are casted to identify the compressive strength, split tensile strength and flexural strength respectively. Casted specimens are tested at 7 and 28 days. The identified results from concrete using plastic aggregate are compared with conventional concrete. Result shows that reduction in mechanical properties of plastic aggregate added concrete. This reduction in strength is mainly due to poor bond strength between cement and plastic aggregate.

Effect of boron waste on the properties of mortar and concrete.

PubMed

Topçu, Iker Bekir; Boga, Ahmet Raif

2010-07-01

Utilization of by-products or waste materials in concrete production are important subjects for sustainable development and industrial ecology concepts. The usages as mineral admixtures or fine aggregates improve the durability properties of concrete and thus increase the economic and environmental advantages for the concrete industry. The effect of clay waste (CW) containing boron on the mechanical properties of concrete was investigated. CW was added in different proportions as cement additive in concrete. The effect of CW on workability and strength of concrete were analysed by fresh and hardened concrete tests. The results obtained were compared with control concrete properties and Turkish standard values. The results showed that the addition of CW had a small effect upon the workability of the concrete but an important effect on the reduction of its strength. It was observed that strength values were quite near to that of control concrete when not more than 10% CW was used in place of cement. In addition to concrete specimens, replacing cement with CW produced mortar specimens, which were investigated for their strength and durability properties. The tests of SO( 4) (2-) and Cl(-) effect as well as freeze-thaw behaviour related to the durability of mortar were performed. Consequently, it can be said that some improvements were obtained in durability properties even if mechanical properties had decreased with increasing CW content.

How Concrete Is Concrete?

ERIC Educational Resources Information Center

Gravemeijer, Koeno

2011-01-01

If we want to make something concrete in mathematics education, we are inclined introduce, what we call, "manipulatives", in the form of tactile objects or visual representations. If we want to make something concrete in a everyday-life conversation, we look for an example. In the former, we try to make a concrete model of our own,…

Design and evaluation of high-volume fly ash (HVFA) concrete mixes, report B : bond behavior of mild reinforcing steel in HVFA concrete.

DOT National Transportation Integrated Search

2012-10-01

The main objective of this study was to determine the effect on bond performance : of high-volume fly ash (HVFA) concrete. The HVFA concrete test program consisted of : comparing the bond performance of two concrete mix designs with 70% cement : repl...

Electrokinetic Strength Enhancement of Concrete

NASA Technical Reports Server (NTRS)

Cardenas, Henry E. (Inventor)

2016-01-01

A method and apparatus for strengthening cementitious concrete by placing a nanoparticle carrier liquid in contact with a first surface of a concrete section and inducing a current across the concrete section at sufficient magnitude and for sufficient time that nanoparticles in the nanoparticle carrier liquid migrate through a significant depth of the concrete section.

Electrokenitic Corrosion Treatment of Concrete

NASA Technical Reports Server (NTRS)

Cardenas, Henry E (Inventor)

2015-01-01

A method and apparatus for strengthening cementitious concrete by placing a nanoparticle carrier liquid in contact with a first surface of a concrete section and inducing a current across the concrete section at sufficient magnitude and for sufficient time that nanoparticles in the nanoparticle carrier liquid migrate through a significant depth of the concrete section.

Introduction to Concrete Reinforcing. Instructor Edition. Introduction to Construction Series.

ERIC Educational Resources Information Center

Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

This module on concrete reinforcing is one of a series of modules designed to teach basic skills necessary for entry-level employment in this field. This module contains three instructional units that cover the following topics: (1) concrete reinforcing materials; (2) concrete reinforcing tools; and (3) concrete reinforcing basic skills. Each…

Highway concrete pavement technology development and testing. Volume 5, Field evaluation of Strategic Highway Research Program (SHRP) C-206 test sites (bridge deck overlays)

DOT National Transportation Integrated Search

2006-08-01

Two types of concrete overlays silica fume concrete (SFC) and latex-modified Type III portland cement concrete (LMC-III) were installed ant tested as part of the Strategic Highway Research Program (SHRP) Project C-206: Optimization of Highway Concret...

Concrete Mixing Methods and Concrete Mixers: State of the Art

PubMed Central

Ferraris, Chiara F.

2001-01-01

As for all materials, the performance of concrete is determined by its microstructure. Its microstructure is determined by its composition, its curing conditions, and also by the mixing method and mixer conditions used to process the concrete. This paper gives an overview of the various types of mixing methods and concrete mixers commercially available used by the concrete industry. There are two main types of mixers used: batch mixers and continuous mixers. Batch mixers are the most common. To determine the mixing method best suited for a specific application, factors to be considered include: location of the construction site (distance from the batching plant), the amount of concrete needed, the construction schedule (volume of concrete needed per hour), and the cost. Ultimately, the quality of the concrete produced determines its performance after placement. An important measure of the quality is the homogeneity of the material after mixing. This paper will review mixing methods in regards to the quality of the concrete produced. Some procedures used to determine the effectiveness of the mixing will be examined. PMID:27500029

Assessment of concrete damage and strength degradation caused by reinforcement corrosion

NASA Astrophysics Data System (ADS)

Nepal, Jaya; Chen, Hua-Peng

2015-07-01

Structural performance deterioration of reinforced concrete structures has been extensively investigated, but very limited studies have been carried out to investigate the effect of reinforcement corrosion on time-dependent reliability with consideration of the influence of mechanical characteristics of the bond interface due to corrosion. This paper deals with how corrosion in reinforcement creates different types of defects in concrete structure and how they are responsible for the structural capacity deterioration of corrosion affected reinforced concrete structures during their service life. Cracking in cover concrete due to reinforcement corrosion is investigated by using rebar-concrete model and realistic concrete properties. The flexural strength deterioration is analytically predicted on the basis of bond strength evolution due to reinforcement corrosion, which is examined by the experimental data available. The time-dependent reliability analysis is undertaken to calculate the life time structural reliability of corrosion damaged concrete structures by stochastic deterioration modelling of reinforced concrete. The results from the numerical example show that the proposed approach is capable of evaluating the damage caused by reinforcement corrosion and also predicting the structural reliability of concrete structures during their lifecycle.

Analysis of Transparent Concrete as an Innovative Material Used in Civil Engineering

NASA Astrophysics Data System (ADS)

Zielińska, Monika; Ciesielski, Albert

2017-10-01

Since the dawn of history concrete has been, right behind stone and brick, one of the oldest building materials. The ancient Romans took advantage of its opportunities. They constructed amazing architectural objects, which survived centuries as whole buildings or parts of them. Concrete is so ubiquitous, that when we are walking in a newer districts of cities we are virtually surrounded by concrete from everywhere. Sometimes we do not realize in how many cases and various ways concrete is used in towns and cities. As we know, human curiosity and quest for newer and newer solutions and capabilities does not leave such amazing material as concrete alone. There are many varieties of concrete, depending on what people want to achieve. By changing its chemical composition, technological process and adding various other materials, we receive various types of concrete. We use them to create durable supporting structures, a variety of concrete which is resistant to constant moisture or different chemical types. Additionally, some aspects of aesthetics in architecture are made with the help of concrete.