WorldWideScience

Sample records for bridge waterways

  1. Statistical Analysis of Ship Collisions with Bridges in China Waterway

    Institute of Scientific and Technical Information of China (English)

    DAI Tong-yu; NIE Wu; LIU Ying-jie; WANG Li-ping

    2002-01-01

    Having carried out investigations on ship collision accidents with bridges in waterway in China, a database of ship collision with bridge (SCB) is developed in this paper. It includes detailed information about more than 200 accidents near ship's waterways in the last four decades, in which ships collided with the bridges. Based on the information a statistical analysis is presented tentatively. The increase in frequency of ship collision with bridges appears, and the accident quantity of the barge system is more than that of single ship. The main reason of all the factors for ship collision with bridge is the human errors, which takes up 70%. The quantity of the accidents happened during flooding period shows over 3~6 times compared with the period from March to June in a year. The probability follows the normal distribution according to statistical analysis. Visibility, span between piers also have an effect on the frequency of the accidents.

  2. 78 FR 37969 - Safety Zone; South Park Bridge Construction, Lower Duwamish Waterway, Seattle, WA

    Science.gov (United States)

    2013-06-25

    ...The Coast Guard is establishing a temporary safety zone in the lower Duwamish Waterway around the South Park Bridge in Seattle, Washington for the re-construction of the bridge. The safety zone is necessary to ensure the safety of the maritime public and workers involved in the bridge construction. The safety zone will prohibit any person or vessel from entering or remaining in the safety zone......

  3. Evaluation of streambed scour at bridges over tidal waterways in Alaska

    Science.gov (United States)

    Conaway, Jeffrey S.; Schauer, Paul V.

    2012-01-01

    The potential for streambed scour was evaluated at 41 bridges that cross tidal waterways in Alaska. These bridges are subject to several coastal and riverine processes that have the potential, individually or in combination, to induce streambed scour or to damage the structure or adjacent channel. The proximity of a bridge to the ocean and water-surface elevation and velocity data collected over a tidal cycle were criteria used to identify the flow regime at each bridge, whether tidal, riverine, or mixed, that had the greatest potential to induce streambed scour. Water-surface elevations measured through at least one tide cycle at 32 bridges were correlated to water levels at the nearest tide station. Asymmetry of the tidal portion of the hydrograph during the outgoing tide at 12 bridges indicated that riverine flows were stored upstream of the bridge during the tidal exchange. This scenario results in greater discharges and velocities during the outgoing tide compared to those on the incoming tide. Velocity data were collected during outgoing tides at 10 bridges that experienced complete flow reversals, and measured velocities during the outgoing tide exceeded the critical velocity required to initiate sediment transport at three sites. The primary risk for streambed scour at most of the sites considered in this study is from riverine flows rather than tidal fluctuations. A scour evaluation for riverine flow was completed at 35 bridges. Scour from riverine flow was not the primary risk for six tidally-controlled bridges and therefore not evaluated at those sites. Field data including channel cross sections, a discharge measurement, and a water-surface slope were collected at the 35 bridges. Channel instability was identified at 14 bridges where measurable scour and or fill were noted in repeated surveys of channel cross sections at the bridge. Water-surface profiles for the 1-percent annual exceedance probability discharge were calculated by using the Hydrologic

  4. Andean waterways

    DEFF Research Database (Denmark)

    Rasmussen, Mattias Borg

    , social, and cultural concerns. Set in the highland town of Recuay in Ancash, the book traces the ways in which water affects political and ecological relations as glaciers recede. By looking at the shared waterways of four villages located in the foothills of Cordillera Blanca, it addresses pertinent...

  5. 33 CFR 117.821 - Atlantic Intracoastal Waterway, Albermarle Sound to Sunset Beach.

    Science.gov (United States)

    2010-07-01

    ..., Albermarle Sound to Sunset Beach. 117.821 Section 117.821 Navigation and Navigable Waters COAST GUARD... § 117.821 Atlantic Intracoastal Waterway, Albermarle Sound to Sunset Beach. (a) The drawbridges across... this paragraph: (1) Onslow Beach Swing Bridge, mile 240.7, at Cap Lejeune, NC, between 7 a.m. and 7...

  6. National Waterway Network (line), Geographic WGS84, BTS (2006) [usace_nav_waterway_lin_BTS_2006

    Data.gov (United States)

    Louisiana Geographic Information Center — The National Waterway Network is a comprehensive network database of the nation's navigable waterways. The data set covers the 48 contiguous states plus the...

  7. Navigable Waterway Routes (National) - National Geospatial Data Asset (NGDA) Waterway Lines

    Data.gov (United States)

    Department of Transportation — The National Waterway Network (NTAD 2015) is a comprehensive network database of the nation's navigable waterways. The data set covers the 48 contiguous states plus...

  8. Navigable Waterway Nodes (National) - National Geospatial Data Asset (NGDA) Waterway Nodes

    Data.gov (United States)

    Department of Transportation — The National Waterway Network (NTAD 2015) is a comprehensive network database of the nation's navigable waterways. The data set covers the 48 contiguous states plus...

  9. National Waterway Network (node), Geographic WGS84, BTS (2006) [usace_nav_waterway_nod_BTS_2006

    Data.gov (United States)

    Louisiana Geographic Information Center — The National Waterway Network is a comprehensive network database of the nation's navigable waterways. The data set covers the 48 contiguous states plus the...

  10. Recent waterway incidents around dams

    Energy Technology Data Exchange (ETDEWEB)

    Rowat, L. [Ontario Power Generation Inc., Niagara Falls, ON (Canada)

    2009-07-01

    This presentation discussed recent waterway incidents around dams. Several case histories were presented, including a man who drowned when he slipped from the top of the South Idaho Power Plant Spillway in June 3 2004; 2 brothers who drowned near a spillway in Watson Minnesota, in June, 2004; a jet-skier who plunged to his death after ramping the 50 foot Brasfield Dam, in Virginia in June, 2004; a couple whose boat on Lake Austin was swept up against the sluicegate; an angler who drowned at a dam in Bridgeville, Delaware; a man who drowned swimming below a dam in San Marcos, Texas in April, 2005; and a fisherman who drowned at Logan Martin Dam in Birmingham, Alabama in April, 2005. A list of examples of fatalities at dams in 2004 and international incidents at dams from 2005 and 2006 to 2008 were also provided. Examples of Canadian incidents at dams were also listed. figs.

  11. Artificial Force Fields for Multi-agent Simulations of Maritime Traffic: A Case Study of Chinese Waterway

    NARCIS (Netherlands)

    Xiao, F.; Ligteringen, H.; Van Gulijk, C.; Ale, B.J.M.

    2012-01-01

    Collisions are an important factor in probabilistic risk modeling of waterway infrastructures. Especially in the design of bridges and terminals, the probability of ship collision is important. Researchers are looking for simulations that mimic ship behavior and estimate accident probabilities rathe

  12. 33 CFR 117.393 - Illinois Waterway.

    Science.gov (United States)

    2010-07-01

    ...; Cass Street bridge, mile 288.1; Jackson Street bridge, mile 288.4; and Ruby Street bridge, mile 288.7... traffic is complete. (4) When rail traffic approaches the bridge, and the drawspan is in the open position... location. (10) when rail traffic has cleared the bridge, the remote bridge operator shall raise...

  13. Navigated Waterways of Louisiana, Geographic NAD83, LOSCO (1999) [navigated_waterways_LOSCO_1999

    Data.gov (United States)

    Louisiana Geographic Information Center — This is a line dataset of navigated waterways fitting the LOSCO definition: it has been traveled by vessels transporting 10,000 gallons of oil or fuel as determined...

  14. Digital waterway construction based on inland electronic navigation chart

    Science.gov (United States)

    Wang, Xue; Pan, Junfeng; Zhu, Weiwei

    2015-12-01

    With advantages of large capacity, long distance, low energy consumption, low cost, less land occupation and light pollution, inland waterway transportation becomes one of the most important constituents of the comprehensive transportation system and comprehensive water resources utilization in China. As one of "three elements" of navigation, waterway is the important basis for the development of water transportation and plays a key supporting role in shipping economic. The paper discuss how to realize the informatization and digitization of waterway management based on constructing an integrated system of standard inland electronic navigation chart production, waterway maintenance, navigation mark remote sensing and control, ship dynamic management, and water level remote sensing and report, which can also be the foundation of the intelligent waterway construction. Digital waterway construction is an information project and also has a practical meaning for waterway. It can not only meet the growing high assurance and security requirements for waterway, but also play a significant advantage in improving transport efficiency, reducing costs, promoting energy conservation and so on. This study lays a solid foundation on realizing intelligent waterway and building a smooth, efficient, safe, green modern inland waterway system, and must be considered as an unavoidable problem for the coordinated development between "low carbon" transportation and social economic.

  15. Margins of the law pertaining to water supplies and waterways

    International Nuclear Information System (INIS)

    The author examines legal questions coming from points of contact of the law pertaining to water supplies and waterways on the one hand with the Waste Management Law, the Atomic Energy Law and Criminal Law on the other hand. He tries to find ways for solving the practical problems which arise with the execution of the law pertaining to water supplies and waterways. (HSCH)

  16. 78 FR 7670 - Safety Zone; Indian Street Bridge Construction, St. Lucie Canal, Palm City, FL

    Science.gov (United States)

    2013-02-04

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Indian Street Bridge Construction, St... the safety of life and vessels on a narrow waterway during bridge construction for the Indian Street... email Lieutenant Junior Grade Mike H. Wu, Sector Miami Prevention Department, Coast Guard;...

  17. STUDY OF HYDRODYNAMIC FORCES OF SHIPS IN NARROW WATERWAY

    Institute of Scientific and Technical Information of China (English)

    Zhang Xie-dong; Wu Xiu-heng

    2003-01-01

    The collision of ships in narrow waterway may occur for a variety of reasons. The hydrodynamic forces between two ships change the maneuvering characteristics of ships greatly. So based on the boundary element method, this paper proposes a calculation method for hydrodynamic interaction forces between ships under meeting and passing conditions in narrow waterway. The results from this method are compared with the existing results obtained from other theoretical approaches, and they are in good agreement.

  18. 33 CFR 117.123 - Arkansas Waterway.

    Science.gov (United States)

    2010-07-01

    ... channel is open for the passage of vessels. ... establish contact by radiotelephone with the remote drawbridge operator on VHF-FM Channel 12 in Omaha... procedures to request an opening of this bridge when necessary for transit: (1) Normal Flow Procedures....

  19. Railroad Bridges

    Data.gov (United States)

    Department of Homeland Security — Bridges-Rail in the United States According to The National Bridge Inspection Standards published in the Code of Federal Regulations (23 CFR 650.3), a bridge isA...

  20. 76 FR 72839 - Drawbridge Operation Regulation; City Waterway Also Known as Thea Foss Waterway, Tacoma, WA

    Science.gov (United States)

    2011-11-28

    ... the roadway surface and the underlying steel stringer substructure as part a major bridge rehabilitation project. This deviation allows the bridge to remain in the closed position during construction... the Docket Management Facility (M-30), U.S. Department of Transportation, West Building Ground...

  1. Sediment contaminant surveillance in Milford Haven Waterway.

    Science.gov (United States)

    Little, D I; Bullimore, B; Galperin, Y; Langston, W J

    2016-01-01

    Sediment contaminants were monitored in Milford Haven Waterway (MHW) since 1978 (hydrocarbons) and 1982 (metals), with the aim of providing surveillance of environmental quality in one of the UK's busiest oil and gas ports. This aim is particularly important during and after large-scale investment in liquefied natural gas (LNG) facilities. However, the methods inevitably have changed over the years, compounding the difficulties of coordinating sampling and analytical programmes. After a review by the MHW Environmental Surveillance Group (MHWESG), sediment hydrocarbon chemistry was investigated in detail in 2010. Natural Resources Wales (NRW) contributed their MHW data for 2007 and 2012, collected to assess the condition of the Special Area of Conservation (SAC) designated under the European Union Habitats Directive. Datasets during 2007-2012 have thus been more comparable. The results showed conclusively that a MHW-wide peak in concentrations of sediment polycyclic aromatic hydrocarbons (PAHs), metals and other contaminants occurred in late 2007. This was corroborated by independent annual monitoring at one centrally located station with peaks in early 2008 and 2011. The spatial and temporal patterns of recovery from the 2007 peak, shown by MHW-wide surveys in 2010 and 2012, indicate several probable causes of contaminant trends, as follows: atmospheric deposition, catchment runoff, sediment resuspension from dredging, and construction of two LNG terminals and a power station. Adverse biological effects predictable in 2007 using international sediment quality guidelines were independently tested by data from monitoring schemes of more than a decade duration in MHW (starfish, limpets) and in the wider SAC (grey seals). Although not proving cause and effect, many of these potential biological receptors showed a simultaneous negative response to the elevated 2007 contamination following intense dredging activity in 2006. Wetland bird counts were typically at a peak in

  2. 33 CFR 162.65 - All waterways tributary to the Atlantic Ocean south of Chesapeake Bay and all waterways tributary...

    Science.gov (United States)

    2010-07-01

    ... any of the land cuts except as a regular established landing or wharf without written permission... dredged channel or narrow portion of a waterway for the purpose of fishing, if navigation is obstructed... vessel, or whose rigging projects over the side of the vessel so as to endanger passing vessels,...

  3. Myocardial Bridging

    Directory of Open Access Journals (Sweden)

    Shi-Min Yuan

    2016-02-01

    Full Text Available Abstract Myocardial bridging is rare. Myocardial bridges are most commonly localized in the middle segment of the left anterior descending coronary artery. The anatomic features of the bridges vary significantly. Alterations of the endothelial morphology and the vasoactive agents impact on the progression of atherosclerosis of myocardial bridging. Patients may present with chest pain, myocardial infarction, arrhythmia and even sudden death. Patients who respond poorly to the medical treatment with β-blockers warrant a surgical intervention. Myotomy is a preferred surgical procedure for the symptomatic patients. Coronary stent deployment has been in limited use due to the unsatisfactory long-term results.

  4. 33 CFR 329.7 - Intrastate or interstate nature of waterway.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Intrastate or interstate nature of waterway. 329.7 Section 329.7 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF... or interstate nature of waterway. A waterbody may be entirely within a state, yet still be capable...

  5. 76 FR 54703 - Safety Zone; Myrtle Beach Triathlon, Atlantic Intracoastal Waterway, Myrtle Beach, SC

    Science.gov (United States)

    2011-09-02

    ... Triathlon, Atlantic Intracoastal Waterway, Myrtle Beach, SC in the Federal Register (76 FR 124). We received... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Myrtle Beach Triathlon, Atlantic Intracoastal Waterway, Myrtle Beach, SC AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY:...

  6. 76 FR 37700 - Safety Zone; Myrtle Beach Triathlon, Atlantic Intracoastal Waterway, Myrtle Beach, SC

    Science.gov (United States)

    2011-06-28

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Myrtle Beach Triathlon, Atlantic Intracoastal Waterway, Myrtle Beach, SC AGENCY: Coast Guard, DHS. ACTION: Notice of proposed rulemaking... Waterway in Myrtle Beach, South Carolina during the Myrtle Beach Triathlon. The Myrtle Beach...

  7. 77 FR 14321 - Safety Zone; Myrtle Beach Triathlon, Atlantic Intracoastal Waterway, Myrtle Beach, SC

    Science.gov (United States)

    2012-03-09

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Myrtle Beach Triathlon, Atlantic Intracoastal Waterway, Myrtle Beach, SC AGENCY: Coast Guard, DHS. ACTION: Notice of proposed rulemaking... Waterway in Myrtle Beach, South Carolina during the Myrtle Beach Triathlon. The Myrtle Beach...

  8. 76 FR 78151 - Special Local Regulations; Boca Raton Holiday Boat Parade, Intracoastal Waterway, Boca Raton, FL

    Science.gov (United States)

    2011-12-16

    ... SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AA08 Special Local Regulations; Boca Raton Holiday Boat Parade, Intracoastal Waterway, Boca Raton, FL AGENCY: Coast Guard, DHS. ACTION: Temporary final rule... Waterway in Boca Raton, Florida during the Boca Raton Holiday Boat Parade on Saturday, December 17,...

  9. Bridge Management Systems

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper bridge management systems are discussed with special emphasis on management systems for reinforced concrete bridges. Management systems for prestressed concrete bridges, steel bridges, or composite bridges can be developed in a similar way.......In this paper bridge management systems are discussed with special emphasis on management systems for reinforced concrete bridges. Management systems for prestressed concrete bridges, steel bridges, or composite bridges can be developed in a similar way....

  10. Programmevaluierung Bridge

    OpenAIRE

    Warta, Katharina; Good, Barbara; Geyer, Anton

    2009-01-01

    BRIDGE is an initiative funded by the Ministry for Transport, Innovation and Technology (BMVIT) that aims to close the “funding gap” between basic and applied research in stand-alone projects with the primary objective of jointly developing the potential of basic and applied research. BRIDGE acts as an  umbrella structure under which the Austrian Science Fund (FWF) and the  Austrian Research Promotion Agency (FFG) coordinate two thematically open funding programmes: The ...

  11. National Bridge Inventory (NBI) Bridges

    Data.gov (United States)

    Department of Homeland Security — The NBI is a collection of information (database) describing the more than 600,000 of the Nation's bridges located on public roads, including Interstate Highways,...

  12. ORNL Trusted Corridors Project: Watts Bar Dam Inland Waterway Project

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Randy M [ORNL; Gross, Ian G [ORNL; Smith, Cyrus M [ORNL; Hill, David E [ORNL

    2011-11-01

    Radiation has existed everywhere in the environment since the Earth's formation - in rocks, soil, water, and plants. The mining and processing of naturally occurring radioactive materials for use in medicine, power generation, consumer products, and industry inevitably generate emissions and waste. Radiological measuring devices have been used by industry for years to measure for radiation in undesired locations or simply identify radioactive materials. Since the terrorist attacks on the United States on 9-11-01 these radiation measuring devices have proliferated in many places in our nation's commerce system. DOE, TVA, the Army Corps and ORNL collaborated to test the usefulness of these devices in our nation's waterway system on this project. The purpose of the Watts Bar Dam ORNL Trusted Corridors project was to investigate the security, safety and enforcement needs of local, state and federal government entities for state-of-the-art sensor monitoring in regards to illegal cargo including utilization of the existing infrastructure. TVA's inland waterways lock system is a recognized and accepted infrastructure by the commercial carrier industry. Safety Monitoring activities included tow boat operators, commercial barges and vessels, recreational watercraft and their cargo, identification of unsafe vessels and carriers, and, monitoring of domestic and foreign commercial vessels and cargo identification. Safety Enforcement activities included cargo safety, tracking, identification of hazardous materials, waterway safety regulations, and hazardous materials regulations. Homeland Security and Law Enforcement Applications included Radiological Dispersive Devices (RDD) identification, identification of unsafe or illicit transport of hazardous materials including chemicals and radiological materials, and screening for shipments of illicit drugs. In the Fall of 2005 the SensorNet funding for the project expired. After several unsuccessful attempts to

  13. Tidal flow dynamics and background fluorescence of the Atlantic Intracoastal Waterway in the vicinity of Sullivan’s Island and the Isle of Palms, South Carolina, 2011-12

    Science.gov (United States)

    Conrads, Paul A.; Journey, Celeste A.; Clark, Jimmy M.; Levesque, Victor A.

    2013-01-01

    To effectively plan site-specific studies to understand the connection between wastewater effluent and shellfish beds, data are needed concerning flow dynamics and background fluorescence in the Atlantic Intracoastal Waterway near the effluent outfalls on Sullivan’s Island and the Isle of Palms. Tidal flows were computed by the U.S. Geological Survey for three stations and longitudinal water-quality profiles were collected at high and low tide. Flows for the three U.S. Geological Survey stations, the Atlantic Intracoastal Waterway by the Isle of Palms Marina, the Atlantic Intracoastal Waterway by the Ben M. Sawyer Memorial Bridge at Sullivan’s Island, and Breach Inlet, were computed for the 53-day period from December 4, 2011, to January 26, 2012. The largest flows occurred at Breach Inlet and ranged from -58,600 cubic feet per second (ft3/s) toward the Atlantic Intracoastal Waterway to 63,300 ft3/s toward the Atlantic Ocean. Of the two stations on the Atlantic Intracoastal Waterway, the Sullivan’s Island station had the larger flows and ranged from -6,360 ft3/s to the southwest (toward Charleston Harbor) to 8,930 ft3/s to the northeast. Computed tidal flow at the Isle of Palms station ranged from -3,460 ft3/s toward the southwest to 6,410 ft3/s toward the northeast. The synoptic water-quality study showed that the stations were well mixed vertically and horizontally. All fluorescence measurements (recorded as rhodamine concentration) were below the accuracy of the sensor and the background fluorescence would not likely interfere with a dye-tracer study.

  14. Mapping of Escherichia coli Sources Connected to Waterways in the Ruamahanga Catchment, New Zealand.

    Science.gov (United States)

    Dymond, John R; Serezat, Dimitri; Ausseil, Anne-Gaelle E; Muirhead, Richard W

    2016-02-16

    Rivers and streams in New Zealand are natural with free access and used by many people for swimming and fishing. However, pastoral farming with free grazing animals is a common land use in New Zealand and faecal microorganisms from them often end up in waterways. These microorganisms can seriously affect human and animal health if ingested. This paper describes spatial modeling using GIS of Escherichia coli sources in a large catchment (350 000 ha), the Ruamahanga. By examining the pathway of water over and through soils, it is possible to determine whether E. coli sources are connected to waterways or not. The map of E. coli sources connected to waterways provides useful context to those setting water quality limits. This approach avoids the complexity of modeling the fate and transport of E. coli in waterways, yet still permits the assessment of catchment-wide mitigation and best management practice. Fencing of waterways would minimize E. coli sources directly defecated to water and would reduce total E. coli sources by approximately 35%. Introduction of dung beetles would minimize sources connected to waterways by overland flow and would reduce total E. coli sources by approximately 35%. Construction of dairy effluent ponds would minimize sources connected to waterways through high bypass flow in soils and would reduce total E. coli sources by approximately 25%. PMID:26771227

  15. Building Bridges

    DEFF Research Database (Denmark)

    The report Building Bridges adresses the questions why, how and for whom academic audience research has public value, from the different points of view of the four working groups in the COST Action IS0906 Transforming Audiences, Transforming Societies – “New Media Genres, Media Literacy and Trust...... in the Media”, “Audience Interactivity and Participation”, “The Role of Media and ICT Use for Evolving Social Relationships” and “Audience Transformations and Social Integration”. Building Bridges is the result of an ongoing dialogue between the Action and non-academic stakeholders in the field of audience...

  16. 33 CFR 117.451 - Gulf Intracoastal Waterway.

    Science.gov (United States)

    2010-07-01

    ... § 117.451, see the List of CFR Sections Affected, which appears in the Finding Aids section of the... bridge, Algiers Alternate Route, mile 3.8 at Belle Chasse, shall open on signal; except that, from 6...

  17. Building Bridges

    DEFF Research Database (Denmark)

    The report Building Bridges adresses the questions why, how and for whom academic audience research has public value, from the different points of view of the four working groups in the COST Action IS0906 Transforming Audiences, Transforming Societies – “New Media Genres, Media Literacy and Trust...

  18. Bridged graphite oxide materials

    Science.gov (United States)

    Herrera-Alonso, Margarita (Inventor); McAllister, Michael J. (Inventor); Aksay, Ilhan A. (Inventor); Prud'homme, Robert K. (Inventor)

    2010-01-01

    Bridged graphite oxide material comprising graphite sheets bridged by at least one diamine bridging group. The bridged graphite oxide material may be incorporated in polymer composites or used in adsorption media.

  19. Novel scenarios for sustainable waterway sediments management deduced from a decision-support tool

    OpenAIRE

    Lemiere, Bruno; Michel, Pascale; Alary, Claire; Haouche, Laurence; Brequel, Hervé; Jacob, Jérome; Gineys, Nathalie; Laboudigue, Agnès; Laboudigue, Agnes

    2013-01-01

    International audience Introduction: Sediments accumulating in waterways represent a triple threat: for fluvial navigation, for flooding hazards, and for their pollutant contents. Waterways dredging releases millions of m3 of sediments, from which a large part is contaminated or even polluted enough to be considered as hazardous waste. Temporary or final storage on land is no longer a sustainable option. Methods: The GeDSeT decision support tool (DST) aims to provide sediment management op...

  20. Public safety around dams and waterways : European and Swedish perspective

    Energy Technology Data Exchange (ETDEWEB)

    Norstedt, U. [Vattenfal, Stockholm (Sweden)

    2009-07-01

    In Europe, there are more casualties due to misbehaviour and insufficient protection around dams than because of dam breaks. This presentation addressed dam safety and security in Europe. Public safety is a prevailing issue because of fatalities; increased safety requirements in society; increased tourism activities; and experience from other countries such as Canada, France, and the United States. The presentation outlined the benefits of co-operation with a country like Canada and discussed the Swedish experience. It also presented a working group of the International Commission on Large Dams (ICOLD) whose purpose was to learn from each other; foster cooperation and exchange experience between member countries and individuals about public safety in the vicinity of dams and waterways; and compare different legal and management concepts. Several incidents, accidents, and safety policies of other countries and organizations were also offered. The presentation concluded with a discussion of public safety at Stornorrfors, an ideal dam for a public safety pilot project in Sweden. Recommendations included the need for installation of audible and visible alerts/alarms; buoys; fencing; signs; and television monitors. figs.

  1. Provision, transport and deposition of debris in urban waterways

    Institute of Scientific and Technical Information of China (English)

    Deonie Allen; Scott Arthur; Nicolas Wallerstien; Janice Blanc; Heather Haynes

    2015-01-01

    abstract The transport of woody debris from urban surfaces, through local urban waterways, to constriction and blockage risk locations is not well understood. Flume trials have identified debris and water-course dimensions as influential factors on debris movement, and large woody debris movement has been traced in the natural rural environment using time series photography, active transponders, and field surveys. Using novel passive transponder technology, small woody debris has been traced through an urban case study watercourse to establish key influential factors on urban debris transport. Through incorporating urban debris transport detail into the source and deposition process, a complete picture of urban debris transport can be created, supporting effective culvert and trash screen design, watercourse maintenance and blockage risk assessment. This case study highlights that factors beyond watercourse depth and velocity are influential in debris movement within an urban watercourse. Debris dimension and source location upstream are shown to significantly affect the potential for debris to reach a downstream constriction, illustrating a possible distance limitation in nuisance flow debris blockage risk.

  2. Waterway-View Imaging with a Small Unmanned Surface System

    Science.gov (United States)

    Young, S. N.; Peschel, J.

    2015-12-01

    This research investigated the use of a small unmanned surface system (USS) for waterway-view imaging in an intensively managed agricultural landscape. Tile drains commonly dewater landscapes into drainage tributaries so that land uses such as agricultural production can occur. The outlets of tile drain networks, which contribute to the water balance in a river network, are often located on private property and in most instances cannot be readily cataloged. Remote sensing presents one option for identifying tile drain networks but vegetation and other topographic occlusions may obstruct identification. This work presents a case study in the Upper Sangamon River Basin in East-Central Illinois for the use of a small USS utilizing visual sensing with a 360-degree camera as an alternative method of mapping agricultural tile drain outlets for improved hydrologic and hydraulic modeling. The results are expected to serve as groundwork for future design and refinement of small unmanned surface vehicles, as well as improved human interfaces for USS, and a foundation for better understanding human-machine interaction in USS applied to agricultural, riparian, and similar domains.

  3. The operational efficiency of waterway transport of forest chips on Finland's Lake Saimaa

    Energy Technology Data Exchange (ETDEWEB)

    Karttunen, K.; Ranta, T. [Lappeenranta Univ. of Technology, LUT Savo Sustainable Technologies, Mikkeli (Finland); Vaatainen, K.; Asikainen, A. [The Finnish Forest Research Inst., Joensuu (Finland)], E-mail: kalle.karttunen@lut.fi

    2012-11-01

    New and cost-efficient methods for use in supply chains for energy wood should be found, to reach the targets of the renewable energy utilisation set by the European Union. The long-distance waterway transportation of forest fuels should be thoroughly investigated, especially in areas where the transport distance is long and waterways could provide a feasible method of conveying forest fuel. In comparison to transport of forest chips by truck, barge-based waterway transport shows a competitive advantage due to the larger loads and higher bulk density of chips it allows. The cost-efficiency of waterway transportation operations related to forest chips in Finland's Lake Saimaa region was studied using practical demonstrations and discrete-event simulation. The varying demand for fuel wood in three separate bio-power plants on the Saimaa lakeside (near the cities of Varkaus, Mikkeli, and Savonlinna) was addressed in several barge transportation scenarios. Finally, the economy of barge transportation was compared to the economy of truck transportation as a function of transportation distance and in terms of the annual performance of the transportation methods examined. The waterway supply chain of forest chips was cost-competitive to road transport by truck after 100-150 km. According to the simulation study, the most economical waterway transport options were based on fixed barge system and shift-independent harbor logistics where loading and unloading of barges were carried-out with a wheeled loader and a belt conveyor. Total supply chain costs including the best waterway logistics from road side storage to power plant ranged from 10.75 euros to 11.64 euros/MWh in distances of 100-150 km by waterways. The energy-density of forest chips in the barge load was found to be, on average, 25% higher than that in truck hauling, because of the better compaction of chips. Waterway transport is a viable option for long-distance transportation of forest chips in Eastern

  4. A regional waterway management system for balancing recreational boating and resource protection.

    Science.gov (United States)

    Swett, Robert A; Listowski, Charles; Fry, Douglas; Boutelle, Stephen; Fann, David

    2009-06-01

    Florida's coasts have been transformed over the past three decades as population growth and unprecedented demand for individual shore access to bays and estuaries led to the creation of residential canal developments. Thousands of miles of channels and basins were dredged as a by-product of this urbanization process. The navigable waterways that resulted are now being stressed by increasing boat traffic and canal-side activities. Recognizing their common goal to preserve the recreational and ecological value of southwest Florida waterways, the Florida Department of Environmental Protection, the four-county West Coast Inland Navigation District, and the University of Florida Sea Grant College Program signed a Memorandum of Agreement. The signatories agreed to develop a science-based Regional Waterway Management System (RWMS), which is a new approach to waterway planning and permitting based on carefully mapped channel depths, a census of actual boat populations, and the spatial extent of natural resources. The RWMS provides a comprehensive, regional overview of channel conditions and the geographic distribution and severity of existing impediments to safe navigation and resource protection. RWMS information and analyses result in regional-scale permitting to accommodate water-dependent uses while minimizing environmental impacts and reducing public expenditures. Compared with traditional approaches to waterway management, the science-based RWMS is relatively unbiased, objective, transparent, ecologically sound, and fiscally prudent. PMID:19020927

  5. U.S. Navigated Waterway Mile Marker Locations from USCOE source data, Geographic NAD83, LOSCO (2000) [river_mile_markers_USACE_1994

    Data.gov (United States)

    Louisiana Geographic Information Center — This is a point dataset representing 10,044 sequential mile positions of navigable inland waterways and the Gulf Intracoastal Waterway. These data were developed as...

  6. Environmental stress model for evaluation of vessel traffic in ports and waterways

    Institute of Scientific and Technical Information of China (English)

    HU Zhiwu; CHEN Weijiong; INOUE K

    2005-01-01

    Environmental stress model is proposed as an effective tool to the analysis and evaluation of navigational safety in ports and waterways. Marine traffic simulations are carried out in a virtual port area with various arrangements and conditions. Calculations of stress values and traffic volume criteria are illustrated. The simulation results provide a valuable hint for safety management of vessel traffic. The model provides quantitative information and helps administrators in decision making to achieve desired safety level and improve the efficiency of vessel traffic in ports and waterways.

  7. 77 FR 35903 - Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC

    Science.gov (United States)

    2012-06-15

    ... Acronyms DHS Department of Homeland Security FR Federal Register NPRM Notice of Proposed Rulemaking A... Federal Register (73 FR 3316). 4. Public Meeting We do not now plan to hold a public meeting. But you may... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone, Atlantic Intracoastal Waterway;...

  8. 77 FR 44463 - Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC

    Science.gov (United States)

    2012-07-30

    ... INFORMATION: Table of Acronyms DHS Department of Homeland Security FR Federal Register NPRM Notice of Proposed... published in 77 FR 35903. We received no comments on the proposed rule. No public meeting was requested, and... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone, Atlantic Intracoastal Waterway;...

  9. 76 FR 76640 - Drawbridge Operation Regulation; Gulf Intracoastal Waterway (Algiers Alternate Route), Belle...

    Science.gov (United States)

    2011-12-08

    ... . SUPPLEMENTARY INFORMATION: In FR Vol. 76, No. 232, USCG 2011-0959, appearing on page 75507 in the issue of... Alternate Route), Belle Chasse, LA ACTION: Notice of Proposed Rulemaking; Correction. SUMMARY: In the..., Gulf Intracoastal Waterway (Algiers Alternate Route), Belle Chasse, LA. That publication contained...

  10. 76 FR 73998 - Drawbridge Operation Regulations; Gulf Intracoastal Waterway (Algiers Alternate Route), Belle...

    Science.gov (United States)

    2011-11-30

    ... Federal Register (73 FR 3316). Public Meeting We do not now plan to hold a public meeting. But you may... Alternate Route), Belle Chasse, LA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from... Waterway (Algiers Alternate Route), mile 3.8, at Belle Chasse, Plaquemines Parish, Louisiana....

  11. 76 FR 75505 - Drawbridge Operation Regulation; Gulf Intracoastal Waterway (Algiers Alternate Route), Belle...

    Science.gov (United States)

    2011-12-02

    ... Federal Register (73 FR 3316). Public Meeting We do not now plan to hold a public meeting. But you may... Alternate Route), Belle Chasse, LA AGENCY: Coast Guard, DHS. ACTION: Notice of proposed rulemaking. SUMMARY... the Gulf Intracoastal Waterway (Algiers Alternate Route), mile 3.8, at Belle Chasse,...

  12. 78 FR 6208 - Drawbridge Operating Regulations; Gulf Intracoastal Waterway, Belle Chasse, LA

    Science.gov (United States)

    2013-01-30

    ... Chasse, LA AGENCY: Coast Guard, DHS. ACTION: Notice of deviation from drawbridge regulation. SUMMARY: The... Intracoastal Waterway (Algiers Alternate Route), mile 3.8, at Belle Chasse, Plaquemines Parish, Louisiana. This....8, at Belle Chasse, Plaquemines Parish, Louisiana. This maintenance is necessary to make...

  13. Ten years of experience in combining ecology and navigation on Dutch waterways

    NARCIS (Netherlands)

    Boeters, R.E.A.M.; Havinga, H.; Litjens, G.; Verheij, H.J.

    1997-01-01

    In this paper we will discuss the experience gained in the Netherlands with the multifunctional management of waterways. We will especially go into how the functions of rivers and canals for navigation and nature are combined. For this we will briefly go back to the national paper for Seville 1994,

  14. Probabilistic design of the steel structure of the new waterway storm surge barrier

    NARCIS (Netherlands)

    Manen, S.E. van; Vrouwenvelder, A.C.W.M.; Foeken, R.J. van

    1996-01-01

    As part of the sea defence system along the Dutch coast, a storm surge barrier is under construction in the New Waterway, near Rotterdam. The Dutch Ministry of Public Works requires for this structure that the probability of failure is at most 10' per year (104 in life time of 100 years). This is al

  15. 78 FR 72817 - Drawbridge Operation Regulation; Gulf Intracoastal Waterway, Near Moss Lake, LA

    Science.gov (United States)

    2013-12-04

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulation; Gulf Intracoastal Waterway, Near Moss Lake, LA AGENCY: Coast Guard, DHS. ACTION: Notice of deviation from drawbridge regulation. SUMMARY: The... is necessary in order to drive piles for 2 sheave platforms, 2 winch platforms, a walkway, and...

  16. Advection of the salt wedge and evolution of the internal flow structure in the Rotterdam Waterway

    NARCIS (Netherlands)

    De Nijs, M.A.J.; Pietrzak, J.D.; Winterwerp, J.C.

    2011-01-01

    An analysis of field measurements recorded over a tidal cycle in the Rotterdam Waterway is presented. These measurements are the first to elucidate the processes influencing the along-channel current structure and the excursion of the salt wedge in this estuary. The salt wedge structure remained sta

  17. 78 FR 22193 - Special Local Regulations; West Palm Beach Triathlon Championship, Intracoastal Waterway; West...

    Science.gov (United States)

    2013-04-15

    ..., Intracoastal Waterway, West Palm Beach, FL'' in the Federal Register (78 FR 2916). We received no comments on...: Table of Acronyms DHS Department of Homeland Security FR Federal Register NPRM Notice of Proposed... SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AA08 Special Local Regulations; West Palm Beach...

  18. 78 FR 75359 - Waterway Suitability Assessment for Construction and Operation of Liquefied Gas Terminals; Orange...

    Science.gov (United States)

    2013-12-11

    ... regarding our public dockets in the January 17, 2008, issue of the Federal Register (73 FR 3316). Public... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF HOMELAND SECURITY Coast Guard Waterway Suitability Assessment for Construction and Operation of Liquefied...

  19. Prospects of Waterway Development as a Catalyst to Improve Regional and Community Socio-Economy Level

    Directory of Open Access Journals (Sweden)

    Sulaiman M. Yassin

    2010-01-01

    Full Text Available Problem statement: Malaysia has achieved a number of successes in its transportation development. The success of Kuala Lumpur International Airport and Northern and Southern Highway project for examples have given the community lot of benefits in term of social and economic development, but what if an inland waterway system can be developed in Malaysia especially along Pahang River and Muar River. Can this proposed waterway bring significant impact to local people in term of their social and economic development? This has become the main objective of this study which is to investigate whether the future Pahang Muar Waterway could have significant socio-economy impact on the local community or not. Approach: This is a qualitative study. Observations, structured and unstructured in-depth interview and literature analysis were used to gain the data needed the research team has traversed along the way (University Putra Malaysia to Muar to Bahau and ended in Pekan these two rivers flow. For the in-depth interviews, a total of seventeen informants among the public and government officers were selected. Data from the in depth interviews was transcribed verbatim and subsequently analyzed by identifying similarities and consistent themes. A constant comparative method was employed in order to uncover patterns in the data. The data in this study is presented descriptively. Results: From the observation, interviews and literature analysis done, it can be concluded that the Pahang Muar Waterways is believed to develop economic activities, recreational activities, tourism industry, enhance the socio-economy life of local community and provide sustainable mobility. Conclusion/Recommendations: From the results gained, it can be concluded that majority of the community interviewed believed that Pahang Muar waterways offer a vast opportunity for social and economic development for the local community. It can be noted that specific planning on constructing the

  20. Hydrology of and Current Monitoring Issues for the Chicago Area Waterway System, Northeastern Illinois

    Science.gov (United States)

    Duncker, James J.; Johnson, Kevin K.

    2015-10-28

    The Chicago Area Waterway System (CAWS) consists of a combination of natural and manmade channels that form an interconnected navigable waterway of approximately 90-plus miles in the metropolitan Chicago area of northeastern Illinois. The CAWS serves the area as the primary drainage feature, a waterway transportation corridor, and recreational waterbody. The CAWS was constructed by the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC). Completion of the Chicago Sanitary and Ship Canal (initial portion of the CAWS) in 1900 breached a low drainage divide and resulted in a diversion of water from the Lake Michigan Basin. A U.S. Supreme Court decree (Consent Decree 388 U.S. 426 [1967] Modified 449 U.S. 48 [1980]) limits the annual diversion from Lake Michigan. While the State of Illinois is responsible for the diversion, the MWRDGC regulates and maintains water level and water quality within the CAWS by using several waterway control structures. The operation and control of water levels in the CAWS results in a very complex hydraulic setting characterized by highly unsteady flows. The complexity leads to unique gaging requirements and monitoring issues. This report provides a general discussion of the complex hydraulic setting within the CAWS and quantifies this information with examples of data collected at a range of flow conditions from U.S. Geological Survey streamflow gaging stations and other locations within the CAWS. Monitoring to address longstanding issues of waterway operation, as well as current (2014) emerging issues such as wastewater disinfection and the threat from aquatic invasive species, is included in the discussion.

  1. Analysis of Salinity Intrusion in the Waccamaw River and Atlantic Intracoastal Waterway near Myrtle Beach, South Carolina, 1995–2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This record is a USGS unpublished report about saltwater intrusion in the Waccamaw River and the Intracoastal Waterway. Six reservoirs in North Carolina discharge...

  2. Cable Supported Bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    Cable supported bridges in the form of suspension bridges and cable-stayed bridges are distinguished by their ability to overcome large spans.The book concentrates on the synthesis of cable supported bridges, covering both design and construction aspects. The analytical part covers simple methods...... to quantify the different structural configurations and allows a preliminary optimization of the main structure.Included are the most recent advances in structural design, corrosion protection of cables, aerodynamic safety, and erection procedures....

  3. Amazon dams and waterways: Brazil's Tapajós Basin plans.

    Science.gov (United States)

    Fearnside, Philip M

    2015-09-01

    Brazil plans to build 43 "large" dams (>30 MW) in the Tapajós Basin, ten of which are priorities for completion by 2022. Impacts include flooding indigenous lands and conservation units. The Tapajós River and two tributaries (the Juruena and Teles Pires Rivers) are also the focus of plans for waterways to transport soybeans from Mato Grosso to ports on the Amazon River. Dams would allow barges to pass rapids and waterfalls. The waterway plans require dams in a continuous chain, including the Chacorão Dam that would flood 18,700 ha of the Munduruku Indigenous Land. Protections in Brazil's constitution and legislation and in international conventions are easily neutralized through application of "security suspensions," as has already occurred during licensing of several dams currently under construction in the Tapajós Basin. Few are aware of "security suspensions," resulting in little impetus to change these laws.

  4. Coefficients of Propeller-hull Interaction in Propulsion System of Inland Waterway Vessels with Stern Tunnels

    Directory of Open Access Journals (Sweden)

    Jan Kulczyk

    2014-09-01

    Full Text Available Propeller-hull interaction coefficients - the wake fraction and the thrust deduction factor - play significant role in design of propulsion system of a ship. In the case of inland waterway vessels the reliable method of predicting these coefficients in early design stage is missing. Based on the outcomes from model tests and from numerical computations the present authors show that it is difficult to determine uniquely the trends in change of wake fraction and thrust deduction factor resulting from the changes of hull form or operating conditions. Nowadays the resistance and propulsion model tests of inland waterway vessels are carried out rarely because of relatively high costs. On the other hand, the degree of development of computational methods enables’ to estimate the reliable values o interaction coefficients. The computations referred to in the present paper were carried out using the authors’ own software HPSDKS and the commercial software Ansys Fluent.

  5. Portable XRF and wet materials: application to dredged contaminated sediments from waterways

    OpenAIRE

    Lemiere, Bruno; Laperche, Valérie; Haouche, Laurence; Auger, Pascal

    2014-01-01

    International audience The sustainable management of dredged waterway sediments requires on-site determination of the main pollutants to facilitate their safe reuse or treatment. Portable X-ray fluorescence (pXRF) is commonly used for similar applications with contaminated soil, but the high water content of dredged sediments precludes any application of standard methods. Measurements for Pb, Zn, Cu and As were performed on-site on raw wet sediments with 50 to 70% water contents during dre...

  6. The World Bank Policy for Projects on International Waterways : An Historical and Legal Analysis

    OpenAIRE

    Salman M.A. Salman

    2009-01-01

    This study deals with the evolution and context of the Bank policy for projects on international waterways. It starts with a brief description of how the Bank has faced the challenges stemming from such projects, and the different approaches deliberated by the Bank that led to the issuance of the first policy in 1956. The study then reviews the implementation experience of the policy and a...

  7. Interacting effects of vegetation and hydrogeomorphic complexity on nitrate in agricultural waterways

    Science.gov (United States)

    Webster, A.; Cadenasso, M. L.

    2015-12-01

    Intensive cultivation in the California Central Valley has resulted in the loss of ~95% of riparian habitat. In addition, small streams have been replaced by denuded agricultural waterways to convey irrigation drainage high in nitrate (NO3). A variety of strategies are being used to increase riparian vegetation along agricultural waterways, but many of the ecological functions of these novel habitat features are unknown. An extensive study was conducted in summer 2014 to investigate which riparian ecosystem features are associated with variable NO3 levels in waterways draining irrigated cropland. Eighty sites were selected to represent a wide range of riparian vegetation, hydrogeomorphic features, and agricultural contexts. Sites were visited three times to correspond to the early, mid, and late irrigation season. At each visit, water samples were taken 300m apart and analyzed for turbidity, pH, temperature, and NO3. To characterized hydrogeomorphic complexity, the frequency of features associated with transient storage and increased retention time were quantified. Vegetation cover and structure on banks, foreshores, and in channels was also measured. Using a generalized linear model, we tested for the interaction of upstream [NO3-N] with vegetation and hydrogeomorphic variables to predict downstream [NO3-N], the dependent variable. As expected, upstream [NO3-N] strongly predicted downstream [NO3-N] and no features directly predicted downstream [NO3-N]. The frequency of hydrogeomorphic features, however, interacted with upstream [NO3-N] to predict downstream [NO3-N], indicating an effect of hydrogeomorphic complexity on NO3 from up to downstream. Vegetation factors did not interact with upstream [NO3-N], but woody vegetation cover was positively correlated with the frequency of hydrogeomorphic features. These findings support the use of woody riparian vegetation to increase NO3 retention in agricultural waterways, via an indirect association with hydrogeomorphic

  8. Taizhou Yangtze River Bridge

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Taizhou Bridge lies between Taizhou, Zhenjiang and Changzhou City in Jiangsu Province. The total length of Taizhou Bridge is 62.088 kin. The whole line is designed by freeway codes with six lanes in two directions. The wholeinvestment is 9.37 billion RMB and the planned construction duration is 5.5 years. The main bridge crossing the Yangtze River is a continuous three-pylon two-span suspension bridge with the main span of 1 080 m. The bridge system is realized for the first time and ranks first in the world until now.

  9. Inland waterway ports nodal attraction indices relevant in development strategies on regional level

    Science.gov (United States)

    Dinu, O.; Burciu, Ş.; Oprea, C.; Ilie, A.; Rosca, M.

    2016-08-01

    Present paper aims to propose a set of ranking indices and related criteria, concerning mainly spatial analysis, for the inland waterway port, with special view on inland ports of Danube. Commonly, the attraction potential of a certain transport node is assessed by its spatial accessibility indices considering both spatial features of the location provided by the networks that connect into that node and its economic potential defining the level of traffic flows depending on the economic centers of its hinterland. Paper starts with a overview of the critical needs that are required for potential sites to become inland waterway ports and presents nodal functions that coexist at different levels, leading to a port hierarchy from the points of view of: capacity, connection to hinterland, traffic structure and volume. After a brief review of the key inland waterway port ranking criterion, a selection of nodal attraction measures is made. Particular considerations for the Danube inland port case follows proposed methodology concerning indices of performance for network scale and centrality. As expected, the shorter the distance from an inland port to the nearest access point the greater accessibility. Major differences in ranking, dependent on selected criterion, were registered.

  10. Analytical methodology for the study of trace organic pollutants in Trinidad waterways

    Energy Technology Data Exchange (ETDEWEB)

    Moore, R.A.

    1984-01-01

    The objectives of this research were the development of analytical methodology for the identification and quantification of trace organic compounds in water and the application of this methodology to a study of trace organic pollution in the Caroni River an other Trinidad waterways. The study was limited to a region upstream from the Caroni/Arena Water Treatment Plant. The research program was divided into three phases: phase I involved the profiling of the types of pollutants which occur in the waterways; in phase II methods were developed and optimized for the broad-spectrum analysis of trace organic compounds, the emphasis being placed primarily on compounds representative of those classes of compounds identified in phase I; in phase III, methods developed in phase II of the program were applied to a quantitative survey of organic pollutants in the waterways in order to assess the source and fate of the pollutants species. Of critical concern was the impact of the Water Treatment plant on pollutant species which arise upstream from the location of its intake water. Pesticides, polyaromatic hydrocarbons, aliphatic hydrocarbons, phenolic compounds, aliphatic and phthalate esters were the main groups of compounds found in the Caroni River and other rivers which flow directly into the Caroni River.

  11. 77 FR 4247 - Drawbridge Operation Regulations; Atlantic Intracoastal Waterway and Biscayne Bay, Miami, FL

    Science.gov (United States)

    2012-01-27

    ... Biscayne Bay, Miami, FL AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviations from regulations... governing the operation of the following two bridges in Miami, Florida: The Venetian Causeway Bridge (West... because of the Miami International Boat Show. These deviations will result in the bridges only opening...

  12. 77 FR 75553 - Drawbridge Operation Regulation; Atlantic Intracoastal Waterway, Biscayne Bay, and Miami River...

    Science.gov (United States)

    2012-12-21

    ..., Biscayne Bay, and Miami River, Miami, FL AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviations... governing the operation of the following four bridges in Miami, Florida: The Venetian Causeway Bridge (West... Biscayne Bay; the Miami Avenue Bridge, mile 0.3, across the Miami River; and the Brickell Avenue...

  13. Concrete bridge prioritization system

    OpenAIRE

    Kesselring, Debbie Anne

    1995-01-01

    An alternative method of prioritization for concrete bridge maintenance, repair, and rehabilitation activities is required due to the inability of the current system to manage the increasing nmnber of aging concrete bridges. The Concrete Bridge Prioritization System was proposed because of its ability to address the critical technical parameters of safety and cost benefit in prioritization of funding and work allocation. The analysis includes four parts, service life assessment, s...

  14. Bridging the Gap

    DEFF Research Database (Denmark)

    Kramer Overgaard, Majken; Broeng, Jes; Jensen, Monika Luniewska;

    Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures.......Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures....

  15. Bridging the Gap

    OpenAIRE

    Kramer Overgaard, Majken; Broeng, Jes; Jensen, Monika Luniewska; Murdock, Karen; Schmidt, Iben Julie

    2015-01-01

    Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures. Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ve...

  16. Semiconductor bridge (SCB) detonator

    Science.gov (United States)

    Bickes, Jr., Robert W.; Grubelich, Mark C.

    1999-01-01

    The present invention is a low-energy detonator for high-density secondary-explosive materials initiated by a semiconductor bridge igniter that comprises a pair of electrically conductive lands connected by a semiconductor bridge. The semiconductor bridge is in operational or direct contact with the explosive material, whereby current flowing through the semiconductor bridge causes initiation of the explosive material. Header wires connected to the electrically-conductive lands and electrical feed-throughs of the header posts of explosive devices, are substantially coaxial to the direction of current flow through the SCB, i.e., substantially coaxial to the SCB length.

  17. Principles of Bridge Reliability

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Nowak, Andrzej S.

    The paper gives a brief introduction to the basic principles of structural reliability theory and its application to bridge engineering. Fundamental concepts like failure probability and reliability index are introduced. Ultimate as well as serviceability limit states for bridges are formulated...

  18. The floating water bridge

    International Nuclear Information System (INIS)

    When high voltage is applied to distilled water filled in two glass beakers which are in contact, a stable water connection forms spontaneously, giving the impression of a floating water bridge. A detailed experimental analysis reveals static and dynamic structures as well as heat and mass transfer through this bridge

  19. Assessment of vessel-generated waste quantities on the inland waterways of the Republic of Serbia.

    Science.gov (United States)

    Presburger Ulnikovic, Vladanka; Vukic, Marija; Nikolic, Radosav

    2012-04-30

    To establish the quantity and structure of waste generated during inland vessel exploitation, it is necessary to determine the amount of traffic on the waterways, the number of vessel dockings that generate and deliver waste materials to ports, and the types of inland navigation vessels. Criteria must also be established for the calculation of estimated average waste quantities. This paper presents a methodology for the assessment of waste material quantities that was developed as part of the Technological Development Project TR 21037 of the Republic of Serbia. Required information on the amount of traffic, vessel types and numbers as well as the number of dockings was extracted from questionnaires and interviews with watermen and researchers. A set of criteria was defined in order to determine the number of passengers and crewmembers and to establish and classify quantities of vessel-generated waste (sanitary and fecal wastewater, bilge wastewater, waste oils, and solid waste). These data allowed for the Preliminary analysis of the national waterway traffic and transport infrastructure to be carried out. Results presented in this paper have triggered a number of recommendations for the construction of terminals and other facilities for the reception and management of waste streams, from the vessel where the waste is generated to the final destinations for waste processing and deposition. This is particularly applicable to countries who have not yet tackled the problem of vessel-generated waste. PMID:22325587

  20. CLIMATE CHANGE AND THE RISK MANAGEMENT IN SERBIAN INLAND WATERWAY TRANSPORT

    Directory of Open Access Journals (Sweden)

    Todor Backalic

    2012-12-01

    Full Text Available Climate changes require special attention and global monitoring. Impacts on nature and industry are increasingly evident. Water transport could be the backbone of the future European combined transport system. Unfortunately, risks in water transport are perhaps an under researched area and consequently, this article outlines a rationale, why it is necessary to develop competence about risk in water transport. The development of the cargo transport in river traffic depends directly on technical-exploitative characteristics of the network of inland waterways. Research of navigational abilities of inland waterways always comes before building ships or making a transport schedule. Navigation characteristics of rivers have to be determined as precise as possible, especially from the aspect of determination the possible draught of vessels. River transport due to their operational business and environmental conditions faced with several risks having different degrees of consequences. Current risk assessment methods for water transport just consider some dramatic events. We present a new method for the assessment of risk and vulnerability of water transport where river depth represents a crucial part. The analysis of water level changes on Serbian rivers during the last sixty years was done.

  1. Bridge technology report

    CERN Document Server

    2013-01-01

    Please note this is a Short Discount publication. As LANs have proliferated, new technologies and system concepts have come to the fore. One of the key issues is how to interconnect networks. One means of interconnection is to use a 'bridge'. Other competing technologies are repeaters, routers, and gateways. Bridges permit traffic isolation, connect network segments together and operate at the MAC layer. Further, because they operate at the MAC layer, they can handle a variety of protocols such as TCP/IP, SNA, and X.25. This report focuses on the specific technology of bridging two netw

  2. Bridged Race Population Estimates

    Data.gov (United States)

    U.S. Department of Health & Human Services — Population estimates from "bridging" the 31 race categories used in Census 2000, as specified in the 1997 Office of Management and Budget (OMB) race and ethnicity...

  3. Long Span Bridges in Scandinavia

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1998-01-01

    The first Scandinavian bridge with a span of more than 500 m was the Lillebælt Suspension Bridge opened to traffic in 1970.Art the end of the 20th century the longest span of any European bridge is found in the Storebælt East Bridge with a main span of 1624 m. Also the third longest span in Europ...

  4. 78 FR 67938 - Drawbridge Operation Regulation; Atlantic Intracoastal Waterway, Albemarle and Chesapeake Canal...

    Science.gov (United States)

    2013-11-13

    ... accommodate the annual Christmas parade. This deviation allows the bridge to remain in the closed-to-navigation position for the set up of the event and the duration of the Christmas parade. DATES: This... their annual Christmas parade. Normally, the bridge opens on signal; except that, from 6 a.m. to 7...

  5. 78 FR 4070 - Drawbridge Operation Regulations; Atlantic Intracoastal Waterway and Biscayne Bay, Miami, FL

    Science.gov (United States)

    2013-01-18

    ... Biscayne Bay, Miami, FL AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviations from regulations... the following two bridges in Miami, Florida: The Venetian Causeway Bridge (West), mile 1088.6, across... deviations are necessary due to the high volume of vessel and vehicle traffic anticipated during the...

  6. 78 FR 76596 - Proposed Levels of Service at Locks and Dams on the J Bennett Johnston Waterway (Red River)

    Science.gov (United States)

    2013-12-18

    ..., 2013 (78 FR 34083). The hours of availability for locking at Lindy C. Boggs Lock and Dam, John H... Johnston Waterway (Red River) AGENCY: Department of the Army, U.S. Army Corps of Engineers, DoD. ACTION... regulation governing the use, administration, and navigation of the Red River and Locks is Section 4 of...

  7. Aeration remediation of a polluted waterway increases near-surface coarse and culturable microbial aerosols.

    Science.gov (United States)

    Dueker, M Elias; O'Mullan, Gregory D

    2014-04-15

    Aeration remediation is currently used in polluted urban waterways to increase oxygen levels in the water column. Recent studies have provided increasing evidence that the bursting of bubbles at water surfaces introduced by aeration, or other surface disturbances, can transfer viable bacteria to the air. In heavily sewage-polluted waterways these water-originated bacterial aerosols may pose as a health risk to recreators in small boats or residents inhabiting the shoreline. Nonetheless, few studies have explored aerosols above active aeration remediation projects in waterways or investigated how bacterial aerosols change with vertical distance from aeration activities. This study, conducted at the Newtown Creek superfund site in Brooklyn, NY, USA, measured coarse aerosol particles and culturable bacteria in near-surface air above waters undergoing aeration remediation. Regardless of aeration operation culturable bacterial fallout was greater near-surface (0.6m above water) than previously-reported measurements made at 2.5m. Molecular analysis of the 16S rRNA gene sequences from isolated bacteria demonstrates that water and air shared a large number of bacterial genera and that the genera present in the near-surface aerosols (0.6m) contained water-associated Vibrio and Caulobacter, which were not present at 2.5m, despite the smaller sequence library size from the near-surface. Also, the near-surface microbial assemblage had significantly greater association with sequences detected previously in aquatic environments compared to the 2.5m library. We found compelling evidence that aeration activity contributed to this vertical gradient in bacterial aerosol concentrations and identity. Similar to results from 2.5m, concentrations of near-surface respirable coarse aerosols (aeration was occurring. Culturable bacterial aerosol fallout was also greater near-surface when the aerator was on compared to simultaneous measurements made at 2.5m. Furthermore, when the aerator was

  8. Integral Abutment and Jointless Bridges

    OpenAIRE

    Cristian-Claudiu Comisu

    2005-01-01

    Integral bridges, or integral abutment and jointless bridges, as they are more commonly known in the USA, are constructed without any movement joints between spans or between spans and abutments. Typically these bridges have stub-type abutments supported on piles and continuous bridge deck from one embankment to the other. Foundations are usually designed to be small and flexible to facilitate horizontal movement or rocking of the support. Integrally bridges are simple or multiple span ones t...

  9. COMPUTATION OF RETURN FLOWS DUE TO NAVIGATION TRAFFICS IN RESTRICTED WATERWAYS

    Institute of Scientific and Technical Information of China (English)

    B.S.MAZUMDER; S.K.DAS; S.N.DAS

    2006-01-01

    The paper deals with the development of an empirical model to compute the return flow due to the movement of navigation traffics in restricted waterway when the speed of the navigation traffic is under sub-critical range. The velocity profile of the return flow is modelled, where the functional dependence with respect to ambient flow, principal dimensions of the vessel, wetted cross-sectional area of the river, width and average depth of the river, and the lateral distance of the vessel from the bank are implicitly considered. This model has been validated with the observed data collected from the four specific sites, such as Kampsville, Apple River Island, Goose Island and Clarks Ferry of Illinois River during barge-tow movement. The present model shows significant improvement of return flow prediction in comparison to earlier empirical results. This model has also the ability to determine the locus of zero velocity point.

  10. 3-D NUMERICAL SIMULATION OF CONVOY-GENERATED WAVES IN A RESTRICTED WATERWAY

    Institute of Scientific and Technical Information of China (English)

    JI Sheng Cheng; OUAHSINE Abdellatif; SMAOUI Hassan; SERGENT Philippe

    2012-01-01

    We consider waves generated by the passing of convoys in a restricted waterway.The magnitude of these waves depends mainly on the geometrical and kinematical parameters of the convoy,such as the speed and the hull geometry.The objective of this study is to predict the relationship between these geometrical and kinematical parameters and the amplitude of ship-generated waves as well as the water plane drawdown.Numerical simulations are conducted by solving the 3-D Navier-Stokes equations along with the standard k-ε model for turbulent processes.The results are compared first with the empirical model and second with experimental measurements performed by the French company Compagnie National du Rh(o)ne (CNR).

  11. Physical Modeling of Localized Scour for the Yangtze Estuary Waterway Improvement Project, Phase Ⅰ

    Institute of Scientific and Technical Information of China (English)

    JlA Jianjun; LU Wujiang; QIAN Yadong

    2000-01-01

    In order to examine the effectiveness of engineering protection against localized scour in front of the south groin-group of the Yangtze Estuary Waterway Improvement Project, Phase Ⅰ , an undistorted physical model on a geometric scale of 1:250 is built in this study, covering two groins and their adacent estuarine areas. By use of rinsing fix-bed model as well as localized mobile-bed model, the experiment is undertaken under bi-directional steady flow. According to the experimental results, waterway dredging leads to the increase in steram velocity, the increase being larger during the ebb than during the flood. Construction of the upstream groin has some influence on the flow patterns near the downstream groin. Localized scour in front of the groin-heads is controlled mainly by ebb flow. In the case of a riverbed composed entirely of silt, the depths of localized scour in front of the two groin-heads are 27 m and 29 m,respectively. In reality, the underneath sediment of the prototype riverbed is clay whose threshold velocity is much higher than the stream velocity in the Yangtze Estuary; therefore, the depths of localized scour will not be much larger than the thickness of the silt layer, i. e. 7.4 m and 4.7 m, respectively. The designed aprons covering the riverbed in fron of the groin-heads are very effective in scour control. Aprons of slightly smaller size can also fulfill the task of protection, but the area of localized scour increases significantly.

  12. Analysis the Impact of Bridges Existance for the Segamat River Using Infowork RS

    Science.gov (United States)

    Adnan, M. S.; Ali, N. C.; Erfen, Y.; Rahmat, S. N.; Razi, M. A. M.; Musa, S.

    2016-07-01

    Malaysia is experiencing two monsoonal seasons, which have induced heavy rainfall. The increasing of rainfall intensity and longer duration of rainfall has caused a flood. In 2007, Segamat city was hit by the flood due to increasing of rainfall and this has caused a huge damage in term of infrastructure as well as human life. Thus, this study was carried out with the aims to analyze the flood and develop a flood map for the Segamat River. The hydrological data, such as rainfall and streamflow data were retrieved from the Department of Irrigation and Drainage Malaysia (DID). While, for map preparation such as base map, landuse map and river map were delineated based on the topography map. Additionally, contour map was obtained from MACGDI. InfoWork River Simulation (RS) software was used for analysis and develops the flood map. Moreover, two scenarios were carried out to determine the effect of hydraulic structure presence in the waterway. The first scenario is the flood map without a bridge, while the second scenario is the flood map with a bridge. Based on the results, it clearly shows that the flood map with a bridge has higher flow, velocity and water table compared to the flood map without a bridge. In addition, a flood-prone area based on the developed map was identified. Thus, the generated flood map could serve important information to related agency in proposing a suitable design the mitigation works for this area.

  13. Istanbul Bridge Conference 2014

    CERN Document Server

    Gülkan, Polat; Mahmoud, Khaled

    2016-01-01

      The book includes peer-reviewed contributions selected from presentations given at the Istanbul Bridge Conference 2014, held from August 11 – 13 in Istanbul, Turkey. It reports on the current challenges in bridge engineering faced by professionals around the globe, giving a special emphasis to recently developed techniques, innovations and opportunities. The book covers key topics in the field, including modeling and analysis methods; construction and erection techniques; design for extreme events and condition assessment and structural health monitoring. There is a balanced presentation of theory, research and practice. This book, which provides the readers with a comprehensive and timely reference guide on current practices in bridge engineering, is intended for professionals, academic researchers and students alike.

  14. Active Control of Suspension Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper some recent research on active control of very long suspension bridges, is presented. The presentation is based on research work at Aalborg University, Denmark. The active control system is based on movable flaps attached to the bridge girder. Wind load on bridges with or without...... flaps attached to the girder is briefly presented. A simple active control system is discussed. Results from wind tunnel experiments with a bridge section show that flaps can be used effectively to control bridge girder vibrations. Flutter conditions for suspension bridges with and without flaps...

  15. Web 多维数字航道监控平台%Web multidimensional digital waterway monitoring platform

    Institute of Scientific and Technical Information of China (English)

    潘明阳; 刘涛; 王德强; 赵德鹏; 张新宇

    2014-01-01

    基于二维电子航道图和三维航道模型,提出了一种新的 Web 多维数字航道监控平台。基于Java设计了 Web 多维数字航道监控平台架构。为了加快平台的绘制速度,基于四叉树空间数据组织和数据预读策略对多维数字航道模型进行优化。为实现大范围的航道动态监控,研究了航道中船舶与航标动态信息的数据组织、获取、绘制和查询,提出了一种基于折半抽稀的动态目标图层绘制算法与一种基于光线投射的三维空间动态目标拾取算法。测试结果表明:平台运行稳定、平滑,通过 Web 在一个统一的框架下同时展现航道地形、码头设施和建筑物构成的三维航道模型和二维电子航道图,实时动态监控辖区内的船舶和航标。%Based on two-dimensional electronic navigational chart (ENC )and three-dimensional waterway model, a new web multidimensional digital waterway monitoring platform was proposed.The architecture of the platform was designed based on Java.In order to enhance the rendering speed of the platform,quadtree-based spatial data organization and data prefetching strategy were applied to optimize the multidimensional waterway model.In order to implement large scale waterway dynamic monitoring,the organization,access,display and query of dynamic information of ships and buoys in waterway were researched, and a binary thinning based rendering algorithm of dynamic obj ect layer and a ray casting based picking operation of dynamic object in 3D space were proposed.Test result shows that the platform operates steady and smooth.Through the web,the platform can display three dimensional waterway’ s terrains, wharf facilities,buildings and two dimensional ENCs in a unified multidimensional framework, and monitor the real-time dynamic states of all vessels and buoys in waterway.8 figs,15 refs.

  16. Geographic Information System (GIS) characterization of benthic and emergent areas in the Intracoastal Waterway, Sarasota County, Florida in 1987 (NODC Accession 0000607)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This GIS layer graphically represents algae, seagrass, tidal marshes, mangroves, and oyster bed coverages found throughout the Intracoastal Waterway in Sarasota...

  17. Quantum Bidding in Bridge

    Science.gov (United States)

    Muhammad, Sadiq; Tavakoli, Armin; Kurant, Maciej; Pawłowski, Marcin; Żukowski, Marek; Bourennane, Mohamed

    2014-04-01

    Quantum methods allow us to reduce communication complexity of some computational tasks, with several separated partners, beyond classical constraints. Nevertheless, experimental demonstrations of this have thus far been limited to some abstract problems, far away from real-life tasks. We show here, and demonstrate experimentally, that the power of reduction of communication complexity can be harnessed to gain an advantage in a famous, immensely popular, card game—bridge. The essence of a winning strategy in bridge is efficient communication between the partners. The rules of the game allow only a specific form of communication, of very low complexity (effectively, one has strong limitations on the number of exchanged bits). Surprisingly, our quantum technique does not violate the existing rules of the game (as there is no increase in information flow). We show that our quantum bridge auction corresponds to a biased nonlocal Clauser-Horne-Shimony-Holt game, which is equivalent to a 2→1 quantum random access code. Thus, our experiment is also a realization of such protocols. However, this correspondence is not complete, which enables the bridge players to have efficient strategies regardless of the quality of their detectors.

  18. Bridge of Light

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Lying gleaming white under a brooding sky,the Lhasa River Railway Bridge forms a gate to Lhasa City.Built as a part of Qinghai-Tibet Railway,on July 1,2011, the highest altitude railway in the world has been in service for five years. Lhasa,Tibet

  19. Bridge over troubled water?

    DEFF Research Database (Denmark)

    Svendsen, Gunnar Lind Haase; Nannestad, Peter; Svendsen, Gert Tinggaard

    2008-01-01

    The problem of integrating non-Western immigrants into Western welfare states is the focus of this paper. To address this issue, we suggest a social capital approach in which we apply the conceptual pair of bridging social capital (BR), which connects an individual to the broader social structure...

  20. Building Bridges to China.

    Science.gov (United States)

    Wasta, Stephanie; Scott, Margaret

    1998-01-01

    Describes a theme cycle called "Building Bridges to China" developed for third grade students that focuses on the similarities between the lives of children and families in China and the United States. Explains that the theme cycle addresses the National Geography Standards and three of the National Council for the Social Studies standards. (CMK)

  1. Revised Rules for Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Jensen, F. M.; Middleton, C.;

    This paper is based on research performed for the Highway Agency, London, UK under the project DPU/9/44 "Revision of Bridge Assessment Rules Based on Whole Life Performance: Concrete Bridges" It contains details of a methodology which can be used to generate Whole Life (WL) reliability profiles....... These WL reliability profiles may be used to establish revised rules for Concrete Bridges....

  2. The impact of ornithogenic inputs on phosphorous transport from altered wetland soils to waterways in East Mediterranean ecosystem.

    Science.gov (United States)

    Litaor, M Iggy; Reichmann, O; Dente, E; Naftaly, A; Shenker, M

    2014-03-01

    Large flocks of Eurasian crane (Grus grus, >35,000) have begun wintering in an altered wetland agro-ecosystem located in Northern Israel, a phenomenon that attracts more than 400,000 eco-tourists a year. A 100-ha plot has been used to feed the cranes in order to protect nearby fields. The objective of this study was to evaluate the influence of this bird's feeding practice on the P status of the altered wetland soils and waterways. We installed a series of wells at two depths (40 and 90 cm) between two major waterways in the feeding area and monitored the hydraulic heads and collected groundwater samples for elemental analyses. We collected six soil cores and four sediment samples from the waterways and conducted sequential P extraction. We found significant increase in groundwater soluble reactive P (SRP) (>0.5 mg l(-1)) compared with much lower concentrations (~0.06 mg l(-1)) collected in the period prior to the feeding. We found significant decrease in Fe((II)), Ca, and SO4 concentrations in the shallow groundwater (33, 208, and 213 mg l(-1), respectively) compared with the period prior to the feeding (47, 460, and 370 mg l(-1) respectively). An increase in the more labile P fraction was observed in soils and sediments compared with the period before the feeding. The P input by bird excrement to the feeding area was estimated around 700 kg P per season, while P removal by plant harvesting was estimated around 640 kg Pyr(-1). This finding supports the current eco-tourism practices in the middle of intensive farming area, suggesting little impact on waterways. PMID:24361445

  3. An analysis of accidents involving towboat-barge combination on selected inland waterways of the United States.

    OpenAIRE

    Gamble, William John

    1980-01-01

    Approved for public release; distribution is unlimited This study uses a statistical analysis approach on a computerized data base to analyze accidents involving towboat-barge combinations on the inland waterways of the United States. The main areas explored are the factors affecting the severity and the frequency of accidents. In addition, multiple regression models are used to predict the severity of towboat accidents from a set of independent accident variables. Conclusions and recom...

  4. Computation Of The Residual Radionuclide Activity Within Three Natural Waterways At The Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Hiergesell, R. A.; Phifer, M. A.

    2014-01-07

    analysis data that had been collected for various SRS investigations, as well as the additional streambed and floodplain sampling and analysis data acquired more recently as part of the ongoing SRS IOU program, and associated specifically with the FMB, PB, and SC IOUs. Samples have been acquired along the waterways, within the stream channels themselves and in the adjacent floodplain zones. While Cs-137 is the most significant and abundant radionuclide associated with the SRS waterways, it is not the only radionuclide, hence work was conducted to evaluate all radionuclides present.

  5. Dynamic Bridge Response for a Bridge-friendly Truck

    Directory of Open Access Journals (Sweden)

    V. Šmilauer

    2004-01-01

    Full Text Available A truck with controlled semi-active suspensions traversing a bridge is examined for benefits to the bridge structure. The original concept of a road-friendly truck was extended to a bridge-friendly vehicle, using the same optimization tools. A half-car model with two independently driven axles is coupled with simply supported bridges (beam, slab model with the span range from 5 m to 50 m. Surface profile of the bridge deck is either stochastic or in the shape of a bump or a pot in the mid-span. Numerical integration in the MATLAB/SIMULINK environment solves coupled dynamic equations of motion with optimized truck suspensions. The rear axle generates the prevailing load and to a great extent determines the bridge response. A significant decrease in contact road-tire forces is observed and the mid-span bridge deflections are on average smaller, when compared to commercial passive suspensions. 

  6. A numerical study on ship-ship interaction in shallow and restricted waterway

    Directory of Open Access Journals (Sweden)

    Lee Sungwook

    2015-09-01

    Full Text Available In the present study, a numerical prediction method on the hydrodynamic interaction force and moment between two ships in shallow and restricted waterway is presented. Especially, the present study proposes a methodology to overcome the limitation of the two dimensional perturbation method which is related to the moored-passing ship interaction. The validation study was performed and compared with the experiment, firstly. Afterward, in order to propose a methodology in terms with the moored-passing ship interaction, further studies were performed for the moored-passing ship case with a Reynolds Averaged Navier-Stokes (RANS calculation which is using OpenFOAM with Arbitrary Coupled Mesh Interface (ACMI technique and compared with the experiment result. Finally, the present study proposes a guide to apply the two dimensional perturbation method to the moored-passing ship interaction. In addition, it presents a possibility that the RANS calculation with ACMI can applied to the ship-ship interaction without using a overset moving grid technique.

  7. A numerical study on ship-ship interaction in shallow and restricted waterway

    Science.gov (United States)

    Lee, Sungwook

    2015-09-01

    In the present study, a numerical prediction method on the hydrodynamic interaction force and moment between two ships in shallow and restricted waterway is presented. Especially, the present study proposes a methodology to overcome the limitation of the two dimensional perturbation method which is related to the moored-passing ship interaction. The validation study was performed and compared with the experiment, firstly. Afterward, in order to propose a methodology in terms with the moored-passing ship interaction, further studies were performed for the moored-passing ship case with a Reynolds Averaged Navier-Stokes (RANS) calculation which is using OpenFOAM with Arbitrary Coupled Mesh Interface (ACMI) technique and compared with the experiment result. Finally, the present study proposes a guide to apply the two dimensional perturbation method to the moored-passing ship interaction. In addition, it presents a possibility that the RANS calculation with ACMI can applied to the ship-ship interaction without using a overset moving grid technique.

  8. [Retention of adhesive bridges].

    Science.gov (United States)

    Raes, F; De Boever, J

    1994-04-01

    Since the development of adhesive bridges in the early seventies, the retention and therefore the durability of these bridges has been tremendously improved. Conditioning of the non-precious metal by silanisation, careful acid etching of the enamel and the use of the appropriate composite resin are of prime importance. Furthermore, the meticulous preparation with enough interproximal embrace, occlusal rests, interocclusal clearance and cingulum stops is equally important. Including more teeth in the design does not necessarily lead to an improved retention. Besides the material and technical aspects, the whole clinical procedure needs much attention. The retention does not depend on one single factor, but on the precision of all the necessary clinical steps and on a well-defined selection of the material. In this way a five-year survival rate of close to 80% can be obtained. PMID:11830965

  9. BRIDGING SERVICE QUALITY GAPS

    OpenAIRE

    BARKATH UNISSA

    2012-01-01

    Bridging the Service quality gaps is one of the foremost areas of concern for amarketer. Service marketing is inherently different from product or goods marketing.Services are distinctively characterized by their intangible, heterogeneous, inseparableand perishable nature. The importance of the service sector in today's world is a verywidely accepted and renowned idea. “We are already experiencing a service society“services do have some basic characteristics which make them fundamentally diff...

  10. Bridging as Coercive Accommodation

    CERN Document Server

    Bos, J W; Mineur, A M; Bos, Johan; Buitelaar, Paul; Mineur, Anne-Marie

    1995-01-01

    In this paper we discuss the notion of "bridging" in Discourse Representation Theory as a tool to account for discourse referents that have only been established implicitly, through the lexical semantics of other referents. In doing so, we use ideas from Generative Lexicon theory, to introduce antecedents for anaphoric expressions that cannot be "linked" to a proper antecedent, but that do not need to be "accommodated" because they have some connection to the network of discourse referents that is already established.

  11. Nematic liquid crystal bridges

    Science.gov (United States)

    Doss, Susannah; Ellis, Perry; Vallamkondu, Jayalakshmi; Danemiller, Edward; Vernon, Mark; Fernandez-Nieves, Alberto

    We study the effects of confining a nematic liquid crystal between two parallel glass plates with homeotropic boundary conditions for the director at all bounding surfaces. We find that the free surface of the nematic bridge is a surface of constant mean curvature. In addition, by changing the distance between the plates and the contact angle with the glass plates, we transition between loops and hedgehogs that can be either radial or hyperbolic.

  12. Environmental life cycle assessment comparison between two bridge types: reinforced concrete bridge and steel composite bridge

    DEFF Research Database (Denmark)

    Du, Guangli; Karoumi, Raid

    2013-01-01

    not been integrated into the decision-making process. This paper presents a systematic LCA method for quantifying the environmental impacts for bridges. The comparison study is performed between a reinforced concrete bridge and a steel bridge as an alternative design, with several key maintenance and EOL......The concept of sustainable construction has attracted an increased attention. Bridge infrastructures and their belonged construction activities consume considerable material and energy, which is responsible for large environmental burdens. However, the environmental assessment of bridges has...

  13. Demonstration of Bridge Type Schemes for Maanshan Changjiang River Bridge Under Condition of Complicated River Pattern%复杂河势条件下的马鞍山长江大桥桥型方案论证

    Institute of Scientific and Technical Information of China (English)

    杨光武

    2013-01-01

    马鞍山长江公路大桥所处河段为分汊河段,其中左汊主桥桥址处河势条件复杂,通过对桥址处河势条件及通航要求等建桥条件的综合分析,对5种左汊主桥桥型方案(主跨2×1080m三塔悬索桥方案、主跨1 388 m两塔悬索桥方案、主跨1 180m两塔斜拉桥方案、主跨2×850m三塔斜拉桥方案、主跨1 760m单跨悬索桥方案)从航道适应性、工程经济性进行比较和论证.经过综合比选,确定马鞍山长江公路大桥左汊主桥采用主跨2×1 080 m三塔两跨悬索桥,较好地解决了深槽左右摆动引起的航道适应性问题,为大桥的顺利立项和获批创造了有利条件.%The river reaches at the site of Maanshan Changjiang River Highway Bridge are the forked reaches, of which the condition of river pattern of the reach at the site of the main bridge of the left bridge is quite complicated. Through the comprehensive analysis of the construction conditions, such as the river pattern and navigation requirements, of the site of the main bridge, five bridge type schemes (i. e. a three-tower suspension bridge with main spans 2×1 080 m, a two-tower suspension bridge with a main span 1 388 m, a two-pylon cable-stayed bridge with a main span 1 180 m, a three-pylon cable-stayed bridge with main spans 2×850 m and a single-span suspension bridge with a main span 1 760 m) put forward for the bridge were compared and demonstrated from aspects of the waterway adaptability and engineering economy. On the basis of the comparison and demonstration, it was finally determined that the scheme of the three-tower and two-span suspension bridge with main spans 2×1080 m should be chosen for the bridge. With the chosen scheme, the problem of the waterway adaptability affected by the left and right swaying of the deep channel was well resolved and the favorable conditions for the successful determining and approval of the bridge project were thus created.

  14. 76 FR 70349 - Drawbridge Operation Regulation; Atlantic Intracoastal Waterway, Albemarle and Chesapeake Canal...

    Science.gov (United States)

    2011-11-14

    ... necessary to accommodate the annual Christmas parade event. DATES: This deviation is effective from 4 p.m... 117.997(g), to accommodate the annual Christmas parade event. Normally, the bridge opens on signal... of 8.5 feet, above mean high water. The Chesapeake annual Christmas parade event is scheduled...

  15. 76 FR 3516 - Drawbridge Operation Regulation; Gulf Intracoastal Waterway, Belle Chasse, LA

    Science.gov (United States)

    2011-01-20

    ... Chasse, LA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulations. ] SUMMARY...), mile 3.8, at Belle Chasse, Plaquemines Parish, Louisiana. The deviation is necessary to facilitate..., Joint Reserve Base at Belle Chasse, Louisiana. This deviation allows the bridge to remain closed...

  16. Vulnerability of bridges to fire

    DEFF Research Database (Denmark)

    Giuliani, Luisa; Crosti, C.; Gentili, F.

    2012-01-01

    Even if recent effort in developing methodology and measures for design structures against fire and explosions has been mostly focused on buildings, bridges can also be very sensitive to those actions, as witnesses by some recent bridge accidents, which caused major economic losses and also...... endangered people safety in few cases. Purpose of this paper is making a focus on the state of the art of the research and current regulations concerning the response of bridges to fire. Several cases of bridge fires are reported and a focus is made on the occurrence and consequence of bridge fires......, considering both the costs deriving by structural damages and by limited serviceability and other indirect societal aspects. Few cases of recent bridge fire are reviewed in detail and structural consequences are highlighted, distinguishing between damages directly induced by fire and damages induced by local...

  17. Controls on water acidification and de-oxygenation in an estuarine waterway, eastern Australia

    Science.gov (United States)

    Lin, C.; Wood, M.; Haskins, P.; Ryffel, T.; Lin, J.

    2004-09-01

    The quality of soil and water was investigated in an estuarine floodplain system, eastern Australia. The backswamp portion of the floodplain is underlain by sulfidic sediments at depths about 0.5-0.9 m below the ground surface. Actual acid sulfate soils have developed due to sulfide oxidation as a consequence of land drainage since the early 1900s. These acid sulfate soils have a high measured total actual acidity (TAA, up to 500 mmol H +/kg). However, only a very small proportion (quality monitoring in the creek (Rocky Mouth Creek) draining the estuarine embayment during the period from May 1998 to July 2000 shows that acidic flows (pHexported into the creek from acid sulfate soils through an artificial drain network. It is hypothesized that Fe 2+ is being generated by biological iron reduction, which consumes H + and thereby drives the conversion of retained acids to soluble acids. This allows the release of retained acids and subsequently the translocation of acids from soils to the adjacent waterway. Monitoring results also show clear responses of pH and dissolved oxygen (DO) to heavy rainfall events during the period of alternating high (>6) pH-dominated flows. Frequently, pH and DO levels in the creek water drop during flooding. Results from field investigation and experimental simulation suggest that DO depletion associated with organic matter decomposition takes place rapidly in the floodwater inundating the soils and this DO-depleted water has a significant capacity to further de-oxygenate any receiving water. However, the consumption of DO in floodwater is not clearly related to oxidation of Fe 2+. It is not certain what other DO consumers are involved in the process and further research is needed to fill this knowledge gap.

  18. About Some Aspects of Development of the Domestic Market of Services of the Waterway Transport

    Directory of Open Access Journals (Sweden)

    Marina V. Kogan

    2015-06-01

    Full Text Available One of fundamental factors of development of national economy in modern conditions is a transport complex of the country. The analysis shows, historically raising of many developed countries in many respects was provided with concentration of the state transport policy on optimization of conditions for creation of mass, large-scale transportations that is caused by the acceleration of technical progress involving the growing need of economy for increase in speed of transportations, the tonnage of vehicles, etc. Territorial reserves of Russia demand harmonious development of all transport complex, including, railway, automobile, air, water. Shows world experiment, in the countries with such abundance of the rivers, waterways as in Russia one of decisive factors of growth of volumes of transportation of goods and passengers, increase of efficiency of deliveries in scales of all national economy, is the maximum use of a water transport which, other things being equal, manages to the state tens times cheaper than the contents automobile and the railroads. Currently time for the domestic market of transport services, unlike world, lack of close integration and interrelations in the form of commodity transport complexes with presence of managing directors of the transport centers influencing formation of tariff policy is characteristic. At the same time the analysis of productivity of a package of measures of tax support of navigation in the Russian Federation, implementation of the FTP "Development of transport system of Russia (2010 - 2020gody" according to the Concept of long-term social and economic development of the country till 2020 shows their efficiency that is confirmed by positive dynamics of indicators of economic activity of shipping companies, revival of ship-building branch, existence of multiplicative effect due to development of allied industries, revival of business, creation of additional workplaces.

  19. Theory of bridge aerodynamics

    CERN Document Server

    Strømmen, Einar

    2006-01-01

    This text book is intended for studies in wind engineering, with focus on the stochastic theory of wind induced dynamic response calculations for slender bridges or other line ?like civil engineering type of structures. It contains the background assumptions and hypothesis as well as the development of the computational theory that is necessary for the prediction of wind induced fluctuating displacements and cross sectional forces. The simple cases of static and quasi-static structural response calculations are for the sake of completeness also included. The text is at an advanced level in the

  20. Modelling railway bridge asset management

    OpenAIRE

    Le, Bryant Linh Hai

    2014-01-01

    The UK has a long history in the railway industry with a large number of railway assets. Railway bridges form one of the major asset groups with more than 35,000 bridges. The majority of the bridge population are old being constructed over 100 years ago. Many of the bridges were not designed to meet the current network demand. With an expected increasing rate of deterioration due to the increasing traffic loads and intensities, the management authorities are faced with the difficult task of k...

  1. On the Waterway Staff Training Management and Innovation%试论航道员工培训管理与创新

    Institute of Scientific and Technical Information of China (English)

    镇卫兵

    2014-01-01

    近年来我国航道事业随着社会经济的快速发展越来越被重视,航道作为水路运输的重要组成部分,其管理状况对水运发展起着直接影响作用。本文通过对航道现行体制与管理情况探讨,结合员工培训管理与创新分析,提出加强航道管理水平的策略,以实现水运交通事业快速持续健康发展的目标。%In recent years, with the rapid development of social economy, waterway business in China has been paid more and more attention. As an important part of water transportation, waterway's management conditions have a direct impact on water transportation development. Through the discussion of current system and management conditions of waterway, combined with analysis of employee training management and innovation, this article puts forward the strategies to strengthen the waterway management level, in order to achieve the goal of rapid, sustainable and healthy development of waterway transportation business.

  2. Fatigue tests on aluminium bridges

    NARCIS (Netherlands)

    Maljaars, J.; Soetens, F.; Straalen, IJ.J. van

    2005-01-01

    Traffic bridges are subjected to variable loads and should therefore be checked on fatigue. Especially low weight materials, like aluminium, are sensitive to fatigue, because the variable load is a substantial part of the total load. This paper shows the structural design of an aluminium bridge load

  3. Fatigue tests on aluminium bridges

    NARCIS (Netherlands)

    Maljaars, J.; Soetens, F.; Straalen, IJ.J. van

    2004-01-01

    Traffic bridges are subjected to variable loads and should therefore be checked on fatigue. Especially low weight materials, like aluminium, are sensitive to fatigue, because the variable load is a substantial part of the total load. This paper shows the structural design of an aluminium bridge load

  4. Development of cooperative system bridges

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhe; WAN Qi-bai; SHI Lei

    2008-01-01

    Cooperative system bridges comprise several basic structures that act jointly to improve structural characteristics. We delved into the historical development of cooperative system bridges. Cooperative systems are classified as different-load cooperative systems and same-load cooperative systems by distinguishing the modes of load distribution. For different-load cooperation, individual basic structures are at different positions in the direction along bridge axis and carry the loads separately. While for same-load cooperation, all basic structures overlap in geometrical locations and support the entire loads conjointly. The choosing of span ratios between basic structures, the design of connections of different-load cooperative systems were discussed as well as optimizations of relative rigidity for same-load cooperative systems which greatly influence structural characteristics. The general situation and several structural measurements of several cooperative bridges were demonstrated. This information can assist engineers in developing their concepts in cooperative systems and can lead to more efficient and economical cooperative bridges.

  5. Transport and handling of dangerous goods. Training of persons in charge of vehicles or vessels carrying dangerous goods by road or by inland waterways (Dangerous Goods 1979 No.1)

    International Nuclear Information System (INIS)

    This Order supplements the Regulations of 15 April 1945 on the transport of dangerous goods by rail, land and inland waterways. It deals with the training of persons in charge of vehicles or boats carrying dangerous goods by road or by inland waterways. It refers in particular to transport of radioactive materials. (NEA)

  6. Cascaded resonant bridge converters

    Science.gov (United States)

    Stuart, Thomas A. (Inventor)

    1989-01-01

    A converter for converting a low voltage direct current power source to a higher voltage, high frequency alternating current output for use in an electrical system where it is desired to use low weight cables and other circuit elements. The converter has a first stage series resonant (Schwarz) converter which converts the direct current power source to an alternating current by means of switching elements that are operated by a variable frequency voltage regulator, a transformer to step up the voltage of the alternating current, and a rectifier bridge to convert the alternating current to a direct current first stage output. The converter further has a second stage series resonant (Schwarz) converter which is connected in series to the first stage converter to receive its direct current output and convert it to a second stage high frequency alternating current output by means of switching elements that are operated by a fixed frequency oscillator. The voltage of the second stage output is controlled at a relatively constant value by controlling the first stage output voltage, which is accomplished by controlling the frequency of the first stage variable frequency voltage controller in response to second stage voltage. Fault tolerance in the event of a load short circuit is provided by making the operation of the first stage variable frequency voltage controller responsive to first and second stage current limiting devices. The second stage output is connected to a rectifier bridge whose output is connected to the input of the second stage to provide good regulation of output voltage wave form at low system loads.

  7. Applicability of market-based instruments for safeguarding water quality in coastal waterways: Case study for Darwin Harbour, Australia

    Science.gov (United States)

    Greiner, Romy

    2014-02-01

    Water pollution of coastal waterways is a complex problem due to the cocktail of pollutants and multiplicity of polluters involved and pollution characteristics. Pollution control therefore requires a combination of policy instruments. This paper examines the applicability of market-based instruments to achieve effective and efficient water quality management in Darwin Harbour, Northern Territory, Australia. Potential applicability of instruments is examined in the context of biophysical and economic pollution characteristics, and experience with instruments elsewhere. The paper concludes that there is potential for inclusion of market-based instruments as part of an instrument mix to safeguard water quality in Darwin Harbour. It recommends, in particular, expanding the existing licencing system to include quantitative pollution limits for all significant point polluters; comprehensive and independent pollution monitoring across Darwin Harbour; public disclosure of water quality and emissions data; positive incentives for landholders in the Darwin Harbour catchment to improve land management practices; a stormwater offset program for greenfield urban developments; adoption of performance bonds for developments and operations which pose a substantial risk to water quality, including port expansion and dredging; and detailed consideration of a bubble licensing scheme for nutrient pollution. The paper offers an analytical framework for policy makers and resource managers tasked with water quality management in coastal waterways elsewhere in Australia and globally, and helps to scan for MBIs suitable in any given environmental management situation.

  8. Electromagnetic wave survey on voids behind waterway channel lining; Suiro kaikyo sokuheki haimen kudo no denjiha tansa

    Energy Technology Data Exchange (ETDEWEB)

    Koitabashi, H. [Tokyo Electric Power Co. Inc., Tokyo (Japan); Inagaki, M.

    1996-10-01

    Voids behind lining were surveyed by applying electromagnetic wave reflection method to the waterway channel of a hydraulic power plant. Since waterway channel lining is ranged from oblique to vertical direction, voids are hardly formed. However, formation of voids or cavities behind lining is supposed such as voids between ground and lining due to change with time or consolidation settlement, and voids due to soil loss. Electromagnetic radar reflection suggesting continuous void was observed behind terrace concrete lining. As the result of core boring, thin continuous void of 2-5cm thick and more than 100m long was found. This was possibly formed by consolidation settlement for a long time. In some sites, continuous void signal was observed at the upper part of side walls although this signal was smaller than that at the upper part of a terrace. This continuous cavity of 10-20cm thick and 20m long was different from voids, and unevenly distributed at the upper part of an open channel along flowing surface with large flow rate. In addition, it is necessary to clarify the relation to cracks. 2 refs., 4 figs.

  9. Liquid-Bridge Breaking Limits

    Science.gov (United States)

    Macner, Ashley; Steen, Paul

    2011-11-01

    Wet adhesion by liquid bridges in large arrays shows promise for use in lightweight, controllable on-demand devices. Applications include grab/release of wafer substrates, transport of micron-sized tiles for use in 3D printing and micro-dosing of personalized pharmaceutical drugs. By wetting and spreading, a drop can form a bridge and thereby ``grab'' a nearby solid substrate. By volume decrease or extension, the bridge can break. The breaking limit corresponds to bridge instability which can be predicted, knowing the static mechanical response of the bridge. Mechanical behaviors include force-volume (FV), pressure-volume (pV) and force-length (FL) responses. Instability crucially depends on the mode of failure - failure under constant-force or constant length are typical cases. We study single bridge equilibria for their breaking limits. FV diagrams for the pin-pin equal and pin-pin unequal radii boundary conditions for different bridge heights are measured in the laboratory. The FL response in the case of pin-pin equal radii is also measured. Results are compared to predictions of static theory. Static results are then used to compare to dynamical sequences where volume is driven quasistatically by syringe or an electro-osmotic pump. As the breaking limit is approached, the shape deformation accelerates leading to non-equilibrium shapes not captured by the static analysis.

  10. Bridge Creek IMW database - Bridge Creek Restoration and Monitoring Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The incised and degraded habitat of Bridge Creek is thought to be limiting a population of ESA-listed steelhead (Oncorhynchus mykiss). A logical restoration...

  11. National Bridge Inventory - National Geospatial Data Asset (NGDA) Bridges

    Data.gov (United States)

    Department of Transportation — The NBI (NTAD 2015) is a collection of information (database) describing the more than 610,000 of the Nation's bridges located on public roads, including Interstate...

  12. Complex Testing of the Bridges

    Directory of Open Access Journals (Sweden)

    Savić Adrijana

    2016-01-01

    Full Text Available This article describes the process of examining bridges. AB road bridge, founded on the columns by the Karpoš system and damaged due to erosive action of the river, is given as an example. The first tests of the bridge are conducted on the impact load of V 300, because of the appearance of longitudinal cracks. The results of the columns testing are presented in this paper, as well as the rehabilitation measures thus increasing the load capacity of the column.

  13. General design of Sutong Bridge

    Institute of Scientific and Technical Information of China (English)

    Zhang Xigang; Yuan Hong; Pei Minshan; Dai Jie; Xu Lin

    2009-01-01

    The main span of Sutong Bridge is a double-pylon, double-plane cable-stayed bridge with steel box girder, which has the world's longest central span of 1 088 m within cable-stayed bridges. To overcome problems caused by severe meteorological conditions, perplexing hydrological conditions, deep buried bedrock and higher navigation level, many new technics and methods were created. Keys including structural system, steel box girder, stayed cable, tower, pier, tower foundation, collision avoidance system, wind-resistance, seismic-resistance, structural nonlinear response and structural static stability were presented individually in this paper.

  14. Thermal bridges of modern windows

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place; Møller, Eva B.; Nielsen, Anker;

    2013-01-01

    With its focus on reduced energy consumption, contemporary housing construction requires a highly insulated and airtight building envelope with as few thermal bridges as possible.Windows must be carefully designed, as thermal bridges can lead to surface condensation or mold growth, even...... if the window has an U-factor of 1 W/(m2·K) or lower. This paper describes the development of modern, energy efficient Danish windows with reduced thermal bridges. It focuses on materials, geometry, and sealing of window panes based on a literature review. Examples of modern windows are presented. Experience...

  15. Reliability Assessment of Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Middleton, C. R.

    This paper is partly based on research performed for the Highways Agency, London, UK under the project DPU/9/44 "Revision of Bridge Assessment Rules Based on Whole Life Performance: concrete bridges". It contains the details of a methodology which can be used to generate Whole Life (WL) reliability...... profiles. These WL reliability profiles may be used to establish revised rules for concrete bridges. This paper is to some extend based on Thoft-Christensen et. al. [1996], Thoft-Christensen [1996] et. al. and Thoft-Christensen [1996]....

  16. The Higgs Bridge

    CERN Document Server

    Allen, Roland E

    2013-01-01

    The particle recently discovered at the Large Hadron Collider near Geneva is almost certainly a Higgs boson, the long-sought completion of the Standard Model of particle physics. But this discovery, an achievement by more than six thousand scientists (including students), is actually much more than a mere capstone of the Standard Model. It instead represents a bridge from the Standard Model to exciting discoveries of the future, at higher energies or in other experiments, and to the properties of matter at very low temperatures. The mere existence of a particle with zero spin implies a need for new physics, with the most likely candidate being supersymmetry, which requires that every known particle has a superpartner yet to be discovered. And phenomena similar to the Higgs are seen in superconducting metals and superfluid gases at low temperatures, which extend down to a millionth or even a billionth of a degree Kelvin. So the discovery of a Higgs boson has a central place in our attempts both to achieve a tr...

  17. Mineral bridges in nacre revisited

    CERN Document Server

    Checa, Antonio G; Willinger, Marc-Georg

    2012-01-01

    We confirm with high-resolution techniques the existence of mineral bridges between superposed nacre tablets. In the towered nacre of both gastropods and the cephalopod Nautilus there are large bridges aligned along the tower axes, corresponding to gaps (150-200 nm) in the interlamellar membranes. Gaps are produced by the interaction of the nascent tablets with a surface membrane that covers the nacre compartment. In the terraced nacre of bivalves bridges associated with elongated gaps in the interlamellar membrane (> 100 nm) have mainly been found at or close to the edges of superposed parental tablets. To explain this placement, we hypothesize that the interlamellar membrane breaks due to differences in osmotic pressure across it when the interlamellar space below becomes reduced at an advanced stage of calcification. In no cases are the minor connections between superimposed tablets (< 60 nm), earlier reported to be mineral bridges, found to be such.

  18. Simulation of multivariate diffusion bridges

    DEFF Research Database (Denmark)

    Bladt, Mogens; Finch, Samuel; Sørensen, Michael

    We propose simple methods for multivariate diffusion bridge simulation, which plays a fundamental role in simulation-based likelihood and Bayesian inference for stochastic differential equations. By a novel application of classical coupling methods, the new approach generalizes a previously...

  19. Applications of overburden conveyor bridges

    Energy Technology Data Exchange (ETDEWEB)

    Schachtschneider, H.

    1987-06-01

    In large scale surface mines of the capacities required today, a cross-pit operation with overburden conveyor bridges is the most economical method of overburden removal and disposal. In order to provide the production capacity required in surface mining equipment by the GDR brown coal industry, VEB Schwermaschinenbau Lauchhammerwerk undertook the design and manufacture of standard overburden conveyor bridges for cut heights of 34 m, 45 m and 60 m. All three base types may be equipped to match the site specific geological and geotechnical conditions, and to meet customer's demands. Specifications of the bridges are given as well as details of conveyor belt speeds, modifications to the standards, and number manufactured. Design problems faced with the 60 m bridge are discussed, together with details of the superstructure, method of operation, transportation rates, structural steel used, assembly and power supply. 5 refs.

  20. Bridge Culture of Langde Village

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Langde, a village in Leishan County ofsouthwestern Guizhou province, is known for itslarge number of unique bridges bearing the distinctdesign style of the Miao ethnic group. Animpressive variety of well-preserved ancient

  1. Very long term development of the Dutch Inland Waterway Transport System: Policy analysis, transport projections, shipping scenarios, and a new perspective on economic growth and future discounting

    NARCIS (Netherlands)

    Van Dorsser, J.C.M.

    2015-01-01

    This thesis addresses how a new method for the evaluation of policies with a very long term impact on the Dutch Inland Waterway Transport (IWT) system can be developed. It proposes an outline for a very long term transport model, prepares a number of very long term scenarios, and indicates that a di

  2. ANGIOGRAPHIC ASPECTS OF MYOCARDIAL BRIDGES

    Directory of Open Access Journals (Sweden)

    Sujatha. M

    2015-12-01

    Full Text Available Introduction: The segment of epicardial coronary artery that traverses intramurally through the myocardium and bridged by a bunch of cardiac muscle fibers is called tunneled artery or intramural artery. The band of cardiac muscle fibers passing over the tunneled artery segment is named as myocardial bridge. During angiography milking effect is observed during systole due to the external pressure of muscle fibers on the tunneled artery that leads to narrowing of vessel lumen and further ischemia. Materials & Methods: It is a prospective study performed from 2012- 2015 in cardiac centers available around Tirupati, Andhra Pradesh, South India. A total number of 2015 adult patients who underwent diagnostic coronary angiography were evaluated to detect myocardial bridges. With the informed consent the relevant data was collected from the patients and analyzed. Results: The prevalence of myocardial bridges was 3.17%. Among the 2015 patients 70.7% are males and 29.2% are females. Among 64 myocardial bridge positive cases 62.5% were male and 37.5% were female patients. Regarding coronary dominance 84% were right dominant and 14.4% were left dominant and 1.6% are balanced. The percentage incidence of myocardial bridging according to dominance was 3.01% for right dominant patients, 4.12% for left dominant patients and 3.1% for balanced dominant patients. In all the myocardial bridge positive cases they were located on the left anterior descending artery (LAD. According to diagnosis the patients with normal coronaries were 22.6%, patients with MILD CAD were 17.9%, patients with single vessel disease were 23.4%, patients with two vessel disease were 14.7% and the patients with triple vessel disease were 21.3%. The 64 myocardial bridging cases were grouped in to three groups according to their age. Incidence of double bridges was observed in 3 cases of which 66.7% males & 33.3% in females. Conclusion: These results show that Andhra Pradesh population are

  3. The stories of two bridges in Ghana

    DEFF Research Database (Denmark)

    Andreasen, Jørgen

    2004-01-01

    Public participation in bridge building was promoted by un habitat in the village of Mankrong. The neighbouring village did not participate in the construction of their bridge. The first flooding washed the second bridge down while the "participative bridge" stood up....

  4. An Expert System for Concrete Bridge Management

    DEFF Research Database (Denmark)

    Brito, J. de; Branco, F. A.; Thoft-Christensen, Palle;

    1997-01-01

    The importance of bridge repair versus new bridge construction has risen in recent decades due to high deterioration rates that have been observed in these structures. Budgets both for building new bridges and keeping the existing ones are always limited. To help rational decision-making, bridge...

  5. Stability of liquid crystalline bridges

    Science.gov (United States)

    Mahajan, Milind P.; Tsige, Mesfin; Taylor, P. L.; Rosenblatt, Charles

    1999-02-01

    The stability of cylindrical bridges of the liquid crystal octylcyanobiphenyl in an immiscible liquid bath was investigated in the nematic and smectic A phases. In the nematic phase the bridge was found to destabilize at a length-to-diameter (slenderness) ratio R similar to that of ordinary Newtonian fluids. On the other hand, the Bingham behavior of the smectic A phase, i.e., an apparent yield stress, enabled the formation of stable columns with R well in excess of π.

  6. The training, examination and certification of safety advisers for the transport of dangerous goods by road, rail and inland waterways

    International Nuclear Information System (INIS)

    The adoption of the European Union Council Directive 96/35/EC on the appointment and vocational qualification of safety advisers for the transport of dangerous goods by road, rail and inland waterways has posed significant challenges for administrators and industry. The concept of a mandatory qualification in this specific transport area was novel and cut across existing legislative requirements and industry schemes of 'best practice'. Within the Members of the European Union only the United Kingdom opposed the adoption of the Directive fearing that the requirement could lead to increased industry costs without any appreciable enhancement of current safety standards. The United Kingdom lost the debate but being good members of the European Union set out to implement the Directive using the flexibilities contained in the Directive and bearing in mind existing national safety procedures. The aim was implementation with 'as light a touch as possible consistent with the UK's treaty obligations'. (author)

  7. [Spatial Distribution and Potential Ecological Risk Assessment of Heavy Metals in Soils and Sediments in Shunde Waterway, Southern China].

    Science.gov (United States)

    Cai, Yi-min; Chen, Wei-ping; Peng, Chi; Wang, Tie-yu; Xiao, Rong-bo

    2016-05-15

    Environmental quality of soils and sediments around water source area can influence the safety of potable water of rivers. In order to study the pollution characteristics, the sources and ecological risks of heavy metals Zn, Cr, Pb, Cu, Ni and Cd in water source area, surface soils around the waterway and sediments in the estuary of main tributaries were collected in Shunde, and ecological risks of heavy metals were assessed by two methods of potential ecological risk assessment. The mean contents of Zn, Cr, Pb, Cu, Ni and Cd in the surface soils were 186.80, 65.88, 54.56, 32.47, 22.65 and 0.86 mg · kg⁻¹ respectively, and they were higher than their soil background values except those of Cu and Ni. The mean concentrations of Zn, Cr, Pb, Cu, Ni and Cd in the sediments were 312.11, 111.41, 97.87, 92.32, 29.89 and 1.72 mg · kg⁻¹ respectively, and they were higher than their soil background values except that of Ni. The results of principal component analysis illustrated that the main source of Cr and Ni in soils was soil parent materials, and Zn, Pb, Cu and Cd in soils mainly came from wastewater discharge of local manufacturing industry. The six heavy metals in sediments mainly originated from industry emissions around the Shunde waterway. The results of potential ecological risk assessment integrating environmental bioavailability of heavy metals showed that Zn, Cu, Pb and Ni had a slight potential ecological risk. Cd had a slight potential ecological risk in surface soils, but a moderate potential ecological risk in surfaces sediments. Because the potential ecological risk assessment integrating environmental bioavailability of heavy metals took the soil properties and heavy metal forms into account, its results of risks were lower than those of Hakanson methods, and it could avoid overestimating the potential risks of heavy metals.

  8. Research on Spatial Configuration Model of Islands and Waterways Based on Voronoi Diagram%基于Voronoi图的岛礁水道空间配置模型研究

    Institute of Scientific and Technical Information of China (English)

    石伟; 苏奋振; 周成虎

    2014-01-01

    A waterway is any navigable body of water. Waterways can include natural water area such as rivers, lakes, seas, oceans, and artificial water area such as canals and harbor. In order for a waterway to be navigable, it must be deep and wide enough and has suitable hydrology to allow vessels passing safely. In the sea, waterways usually connect mainland or islands. Especially, in the water area filling with reefs, they will be the only passage and the lifeline of the transportations and supplies. The islands and reefs also can influence the security of the wa-terways in that area. Consider the relationships between islands and waterways, it can not only influence the secu-rity of the waterways, but also reflect the value of the islands. In this paper, a spatial configuration model of is-lands and waterways based on Voronoi diagram was proposed to describe the spatial relationships between is-lands and waterways. The intensity of waterways controlled by islands was used to indicate the security state of the waterways and reflect the value of the islands. Then the data of 43 islands and three waterways were used to calculate the intensity and extent of the three waterways controlled by the islands and the spatial configuration of islands and waterways is analyzed. The results of this research showed:(1) the relationship of spatial configura-tion is a key factor of the intensity and extent of the waterways controlled by the islands. (2) Under the spatial in-teraction conditions, the more prominent on the location advantage of islands, the more outstanding on the effect of the control. This study provided a new vision of the security of waterways and the value of islands. The meth-od is easy and useful to evaluate the security of waterways and the value of islands.%水道是连接两侧大陆或岛屿的狭长水域,是水上的生命线。在海洋中,水道通常与岛屿相伴而生,特别在礁体丛生的海域,岛礁与水道间的关系更为微妙,岛

  9. Floating liquid bridge charge dynamics

    Science.gov (United States)

    Teschke, Omar; Soares, David Mendez; Gomes, Whyllerson Evaristo; Valente Filho, Juracyr Ferraz

    2016-01-01

    The interaction of liquid with electric fields is investigated in a configuration where up to 13 kV are applied between electrodes resulting in a 106 V/m electric field in the capillaries and where there is the formation of a free-standing fluid bridge in the interelectrode gap. The Mott-Gurney equation was fitted to the measured ionization current vs applied voltage curve which indicates that the ionization rate at the high-voltage anode electrode dimethylsulfoxide (DMSO) interface and space charging in the interelectrode gap determine the floating liquid bridge current for a given cathode-to-anode voltage. Space charge effects were measured in the cathode becker and also at the liquid bridge since the ionized charges at the anode migrate to the bridge outer surface and decrease the interfacial tension from 43 mJ/m2 to 29 mJ/m2. Two distinct structural regions then form the bridge, a charged plastic (bulk modulus ˜100 MPa) conducting outer layer with a surface conductivity of ˜10-9 Ω-1, which shapes and supports the floating fluid structure, and an inner liquid cylinder, where DMSO molecules flow.

  10. A strange bridge by Leonardo

    CERN Document Server

    Huylebrouck, Dirk

    2013-01-01

    On folio 855 recto of the Codex Atlanticus, Leonardo da Vinci drew three 'easily movable' bridges, but one of them is enigmatic: all 'replicas' in Leonardo museums and exhibitions come as a surprise, to say the least, to any engineer or architect whose attention is drawn to it. This is the case for models in Amboise (France), Chicago and Portland (USA), Florence (Italy) and for the one of the traveling exhibition by the Australian company 'Grande Exhibitions' that already visited 40 major cities in the world. All 'replicas' of the bridge model attributed to Leonardo have pillars standing on the deck of the bridge, while the deck is suspended by cables attached on these pillars. At first sight this problem does not catch the attention of the observer, as the bridge seems to be a mixed form of a beam and a suspension bridge, but it was not overlooked by my colleague architect-engineer Dr. Laurens Luyten (Gent, Belgium). Yet, after a TV-interview in Brussels so much pressure was exerted by some of the museum col...

  11. Bridging history and social psychology

    DEFF Research Database (Denmark)

    Glaveanu, Vlad Petre; Yamamoto, Koji

    2012-01-01

    This special issue aims to bridge history and social psychology by bringing together historians and social psychologists in an exercise of reading and learning from each other’s work. This interdisciplinary exercise is not only timely but of great importance for both disciplines. Social...... hand historians can enhance their analysis of historical sources by drawing upon the conceptual tools developed in social psychology. They can “test” these tools and contribute to their validation and enrichment from completely different perspectives. Most important, as contributions to this special......-traditionalized societies—a distinction that lies at the heart of many social psychology accounts of the world we live in. The present editorial will introduce and consider this act of bridging history and social psychology by focusing on three main questions: What is the bridge made of? How can the two disciplines...

  12. Excitation Methods for Bridge Structures

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, C.R.; Duffy, T.A.; Cornwell, P.J.; Doebling, S.W.

    1999-02-08

    This paper summarizes the various methods that have been used to excited bridge structures during dynamic testing. The excitation methods fall into the general categories of ambient excitation methods and measured-input excitation methods. During ambient excitation the input to the bridge is not directly measured. In contrast, as the category label implies, measured-input excitations are usually applied at a single location where the force input to the structure can be monitored. Issues associated with using these various types of measurements are discussed along with a general description of the various excitation methods.

  13. Bridge Number and Conway Products

    OpenAIRE

    Blair, Ryan C.

    2007-01-01

    Schubert proved that, given a composite link $K$ with summands $K_{1}$ and $K_{2}$, the bridge number of $K$ satisfies the following equation: $$\\beta(K)=\\beta(K_{1})+\\beta(K_{2})-1.$$ In ``Conway Produts and Links with Multiple Bridge Surfaces", Scharlemann and Tomova proved that, given links $K_{1}$ and $K_{2}$, there is a Conway product $K_{1}\\times_{c}K_{2}$ such that $$\\beta(K_{1}\\times_{c} K_{2}) \\leq \\beta(K_{1}) + \\beta(K_{2}) - 1$$ In this paper, we define the generalized Conway prod...

  14. Optimum selection on bridge erection with floating crane in East China Sea Bridge and Hangzhou Bay Bridge

    Institute of Scientific and Technical Information of China (English)

    Shunquan Qin; Pu Zhou; Youheng Hua

    2004-01-01

    @@ Introduction With the rapid development of China′s economy, many bridges will be built over the Chinese coastal waters of Pacific Ocean. Among them, construction of East China Sea Bridge has been commenced in June 2001, and will be completed at the end of 2005, Hangzhou Bay Bridge was also started to construct in June 2003(Fig. 1). These two ultralong bridges are designed as twin expressway bridges standing side by side each carries a 3-lane one-way carriageway. The total width is 31.5m and 33.0m respectively. East China Sea Bridge starts from Nanhui District, Shanghai and extends to the Yangshan Deep Water Port Area, which is located at one of the Qiqu Islands. The total length of the bridge is about 31.0 km, in which 25 km are on the sea, and 22 km is in the unnavigable region. Hangzhou Bay Bridge across the mouth of Qiantang River.

  15. Is myocardial bridging a bridge connecting to cardiovascular events?

    Institute of Scientific and Technical Information of China (English)

    LI Jian-jun

    2010-01-01

    @@ Coronary arteries and their major branches usually course on the surface of the heart in the subepicardial tissue. However, a muscle hber overlying the intramyocardial segment of an epicardial coronary artery was defined as myocardial bridging (MB), and subsequently the artery coursing within the myocardium is called a tunneled artery.

  16. Architectural engineering of FRP bridges

    OpenAIRE

    Smits, J.E.P.

    2014-01-01

    This paper deals with the use of Fibre Reinforced Polymers (FRP's) in architectural and structural bridge design. The challenges and opportunities that come with this relatively new material are discussed. An inventory is made of recent engineers' solutions in FRP, followed by a discussion on architectural application of FRP's derived from the authors architectural practice.

  17. Instability of the capillary bridge

    Science.gov (United States)

    Pare, Gounseti; Hoepffner, Jerome

    2014-11-01

    Capillary adhesion is a physical mechanism that maintains two bodies in contact by capillarity through a liquid ligament. The capillary bridge is an idealization of this capillary adhesion. In this study we first focus on the classical case of the stability of the capillary bridge. Secondly we study a slightly more complex configuration, imagining a flow in the capillary bridge as in the case of the dynamics of the neck of a liquid ligament, in its withdrawal under the effect of capillarity. Inspired by the experiments on soap films of Plateau, the configuration analyzed consists of an initially axisymmetric, mass of fluid held by surface tension forces between two parallel, coaxial, solid pipes of the same diameter. The results presented are obtained by numerical simulations using the free software, Gerris Flow Solver. We first focus on the capillary Venturi. In the static configuration the stability diagram of the capillary bridge obtained is in perfect agreement with the results of Lev A. Slobozhanin. In the dynamic case we develop a matlab code based on the one dimensional equations of Eggers and Dupont. The comparison of the bifurcation diagram obtained and the numerical simulations shows a good agreement.

  18. Bridge Aesthetics and Structural Honesty

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

    In bridges the overall form must be chosen with due respect to the transmission of forces if efficient structures shall be created, The design must therefore be governed by experienced structural engineers - in some cases assisted by aesthetic advisers on specific issues. Some basic requirements...

  19. The Wien Bridge Oscillator Family

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2006-01-01

    A tutorial in which the Wien bridge family of oscillators is defined and investigated. Oscillators which do not fit into the Barkhausen criterion topology may be designed. A design procedure based on initial complex pole quality factor is reported. The dynamic transfer characteristic...

  20. Architectural engineering of FRP bridges

    NARCIS (Netherlands)

    Smits, J.E.P.

    2014-01-01

    This paper deals with the use of Fibre Reinforced Polymers (FRP's) in architectural and structural bridge design. The challenges and opportunities that come with this relatively new material are discussed. An inventory is made of recent engineers' solutions in FRP, followed by a discussion on archit

  1. Intercellular bridges in vertebrate gastrulation.

    Directory of Open Access Journals (Sweden)

    Luca Caneparo

    Full Text Available The developing zebrafish embryo has been the subject of many studies of regional patterning, stereotypical cell movements and changes in cell shape. To better study the morphological features of cells during gastrulation, we generated mosaic embryos expressing membrane attached Dendra2 to highlight cellular boundaries. We find that intercellular bridges join a significant fraction of epiblast cells in the zebrafish embryo, reaching several cell diameters in length and spanning across different regions of the developing embryos. These intercellular bridges are distinct from the cellular protrusions previously reported as extending from hypoblast cells (1-2 cellular diameters in length or epiblast cells (which were shorter. Most of the intercellular bridges were formed at pre-gastrula stages by the daughters of a dividing cell maintaining a membrane tether as they move apart after mitosis. These intercellular bridges persist during gastrulation and can mediate the transfer of proteins between distant cells. These findings reveal a surprising feature of the cellular landscape in zebrafish embryos and open new possibilities for cell-cell communication during gastrulation, with implications for modeling, cellular mechanics, and morphogenetic signaling.

  2. Dynamic identification of paradela historic railway bridge

    OpenAIRE

    Ramos, Luís F.; Valente, Isabel; Guimarães, Paulo; Vazquez, Kevin; Lourenço, Paulo B.

    2013-01-01

    Paradela Bridge is a metallic bridge located along the bank of the Tua River in northern Portugal. While the bridge is not currently in service, its structure is representative of many metallic truss structures built across the country between the 19th and the 20th century. The construction of the Paradela Bridge was completed in 1886 and served for about 120 years connecting northern Portugal. Tua Line belongs to the Douro area that UNESCO recently declared as world heritage. This work acqui...

  3. Transition Slabs of Integral Abutment Bridges

    OpenAIRE

    Dreier, Damien; Muttoni, Aurelio; BURDET, Olivier

    2011-01-01

    Over the past decades, an increasing number of bridges with integral abutment have been built in Switzerland. This type of bridge offers various advantages over standard bridges with abutments, equipped with expansion joints and bearings that require regular inspection and maintenance. One main concern of integral abutment bridges is related to the soil-structure interaction, in particular between the transition slab and the embankment. To avoid any expansion joints, transition slabs are dire...

  4. Path transformations of first passage bridges

    OpenAIRE

    Bertoin, Jean

    2003-01-01

    We define the first passage bridge from 0 to $\\lambda$ as the Brownian motion on the time interval $[0,1]$ conditioned to first hit $\\lambda$ at time 1. We show that this process may be related to the Brownian bridge, the Bessel bridge or the Brownian excursion via some path transformations, the main one being an extension of Vervaat's transformation. We also propose an extension of these results to certain bridges with cyclically exchangeable increments.

  5. The target programme for water pollution control up to year 2005. The impact to alternative pollution load levels on inland waterways; Vesiensuojelun tavoitteet vuoteen 2005. Vaihtoehtoisten kuormitustasojen vaikutukset sisaevesissae

    Energy Technology Data Exchange (ETDEWEB)

    Marttunen, M. [eds.

    1998-11-01

    The publication presents waterway-specific pollution loading surveys connected with the target programme for water pollution control up to 2005 and the results of a survey concerning inland waters. The work evaluates and compares the magnitude and significance of future pollution loads from various sources on the state of the waterway and assesses the impact on the condition of the waterway of two alternative pollution loading levels. The survey was conducted on 24 lakes or parts thereof and 10 rivers. Sixteen of these are subject to loading from the pulls and paper industry. The waterways selected for examination were especially ones for which relatively recent loading analyses were available and to which water quality models have been applied. The general classification of fitness for use was used as a benchmark for changes occurring in the water quality of the waterways. The findings show that particularly the large waterway systems can be moved into a higher fitness for use class by reducing substantially the nutrient loading. Significant improvement in the condition of eutrophic lakes and coastal rivers with their internal loads is difficult. (orig.) 26 refs.

  6. 47 CFR 80.331 - Bridge-to-bridge communication procedure.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Bridge-to-bridge communication procedure. 80..., Alarm, Urgency and Safety Procedures § 80.331 Bridge-to-bridge communication procedure. (a) Vessels... position). I plan to (give proposed course of action). Over. (3) (Coast station), this is (vessel's...

  7. Removal of failed crown and bridge.

    Science.gov (United States)

    Sharma, Ashu; Rahul, G R; Poduval, Soorya T; Shetty, Karunakar

    2012-07-01

    Crown and bridge have life span of many years but they fail for a number of reasons. Over the years, many devices have been designed to remove crowns and bridges from abutment teeth. While the removal of temporary crowns and bridges is usually very straightforward, the removal of a definitive cast crown with unknown cement is more challenging. Removal is often by destructive means. There are a number of circumstances, however, in which conservative disassembly would aid the practitioner in completing restorative/endodontic procedures. There are different mechanisms available to remove a failed crown or bridge. But there is no information published about the classification of available systems for crown and bridge removal. So it is logical to classify these systems into different groups which can help a clinician in choosing a particular type of system depending upon the clinical situation. The aim of this article is to provide a classification for various crown and bridge removal systems; describe how a number of systems work; and when and why they might be used. A PubMed search of English literature was conducted up to January 2010 using the terms: Crown and bridge removal, Crown and bridge disassembly, Crown and bridge failure. Additionally, the bibliographies of 3 previous reviews, their cross references as well as articles published in various journals like International Endodontic Journal, Journal of Endodontics and were manually searched. Key words:Crown and bridge removal, Crown and bridge disassembly, Crown and bridge failure. PMID:24558549

  8. Remediation: Higher Education's Bridge to Nowhere

    Science.gov (United States)

    Complete College America, 2012

    2012-01-01

    The intentions were noble. It was hoped that remediation programs would be an academic bridge from poor high school preparation to college readiness. Sadly, remediation has become instead higher education's "Bridge to Nowhere." This broken remedial bridge is travelled by some 1.7 million beginning students each year, most of whom will…

  9. Comparison between Modern Violin Bridge and Baroque Violin Bridge by Photoelastic Observation and Frequency Analysis

    Science.gov (United States)

    Matsutani, Akihiro

    2004-05-01

    A comparison between the modern bridge and the baroque bridge of the violin by photoelastic observation was carried out. The relationship between the stress part and the hole is symmetric in the modern and baroque bridges. The measured spectral envelopes of baroque bridges are similar to those of modern bridges in D- or G-strings, and have peaks at a frequency higher than those of modern bridges in E-string. The visualization method as used in this study may provide hints for the design of violin bridges.

  10. 梧州市水运物流发展策略研究%The Study on the Development Strategy of Waterway Logistics in Wuzhou City

    Institute of Scientific and Technical Information of China (English)

    彭欣; 杨煜航

    2011-01-01

    通过对西江黄金水道主要城市——梧州市水运物流量现状的深入调查,在分析影响梧州水运物流量的各个要素的基础上,结合梧州市水运物流的实际情况,提出了促进梧州水运物流的发展的主要策略:加快内河航运交通基础设施建设,提升港口水运物流服务水平,调整船舶运力结构,打造水运物流产业链,加快港口信息化、网络化建设。%Detailed investigation is made into the waterway logisticis of Wuzhou,an important city by the golden water course—the west River.After analyzing the main factors impacting the waterway logistics quantity including the local condition,this paper puts forward the development strategy: speeding up the infrastructure construction of river navigation,promoting the logistics service level,adjusting the shipping tonnage structure,creating the waterway logistics industrial chain,and accelerating the informationization and networking of the port.

  11. Comprehensive Real-Time Bridge Health Monitoring System of Tongtai Bridge

    OpenAIRE

    Lei Su-su; Gao Yong-tao; Pan Dan-guang

    2015-01-01

    Tongtai Bridge is the world’s largest suspension curve-girder-skew-arch bridge, which is located in Zhangjiakou, China. The understanding of mechanics characteristics is limited to such complex bridges, so it is necessary to establish reliable health monitoring system to investigate the static and dynamic responses and monitor the safety of the bridge. A comprehensive real-time bridge health monitoring system is establish, which includes four aspects: sensor system, data acquisition and trans...

  12. New Concept for Durable Concrete Bridges

    OpenAIRE

    Damek, Marek

    2015-01-01

    This master’s thesis covers the design of a post-tensioned concrete bridge in Trondheim municipality in Norway, in collaboration with Statens vegvesen (SVV). The concept of the bridge is inspired by Egg-Graben-Brücke in Austria, which was designed and built without steel reinforcement in the bridge deck. The idea is to eliminate steel reinforcement which can corrode in the bridge deck. The total length of the bridge is 73 meters and it is divided into 3 spans. The crosssection ...

  13. Digital 3D reconstruction of Agustin de Betancourt's historical heritage: the machine for cutting grass in waterways

    Directory of Open Access Journals (Sweden)

    José Ignacio Rojas-Sola

    2016-05-01

    Full Text Available Agustín de Betancourt y Molina was one of the most distinguished engineers of the eighteenth and nineteenth centuries with numerous contributions to various fields of engineering, including civil engineering. This research shows the process followed in the documentation of the cultural heritage of that Canary engineer, especially in the geometric documentation of a machine for cutting grass in waterways presented in England in 1795 after three years researching on theory of machines. The baseline information has been recovered from the Canary Orotava Foundation of History of Science who has spent years collecting information about the Project Betancourt, in particular, planimetric information as well as a small report on its operation and description of parts of machine. From this information, we have constructed a three dimensional (3D model using CAD techniques with the use of Solid Edge ST7 parametric software, which has enabled the team to create the 3D model as well as different detail plans and exploded views.

  14. Using Modified Sorbents for Reducing Negative Impact of Oil-Containing Industrial Wastes on Natural and Artificial Waterways

    Directory of Open Access Journals (Sweden)

    Ljudmila Anatolievna Marchenko

    2015-09-01

    Full Text Available The study is aimed at developing and using co-precipitated hydroxides (CPH of aluminum and magnesium as sorbents, in order to reduce the negative impact of oil-containing industrial wastes on natural and artificial waterways. A new method of synthesizing a modified sorbent has been developed, featuring high sorption capacity to a wide range of pollutants in low-acid, neutral, and low-alkaline environments, able to extract complex compounds. A possibility to use this sorbent has been shown, and its sorption capacity has been studied. Sorption parameters have been defined. It has been shown that the value of the maximum achievable concentration efficiency in extracting the said ions on a co-precipitated sorbent is about ten times higher than the corresponding values that characterize sorption on analogous sorbents. In performing analytical studies, standard methods were used, as well as modern methods of physical and chemical analysis: x-ray phase, x-ray fluorescent, atomic absorption, spectral, chemical, thin layer chromatography, and chromato-mass-spectrometry. The specific surface of the samples was defined by the temperature of nitrogen absorption, using the chromatographic method, followed by processing the obtained results using the Brunauer-Emmett-Teller method. Porosity was defined using mercury porometry. The performed research has made it possible to obtain new highly efficient sorbents and assess their economic efficiency. The performed research will make it possible to resolve ecological and social problems by preventing the damage caused by environmental pollution with anthropogenous wastes.

  15. Wireless monitoring of scour and re-deposited sediment evolution at bridge foundations based on soil electromagnetic properties

    Science.gov (United States)

    Michalis, Panagiotis; Tarantino, Alessandro; Tachtatzis, Christos; Judd, Martin D.

    2015-12-01

    Hydraulic structures constitute the most vulnerable elements of transportation infrastructure. Recent increases in precipitation have resulted in severe and more frequent flash flooding incidents. This has put bridges over waterways at higher risk of failure due to scour. This study presents a new sensor for measuring scour depth variation and sediment deposition processes in the vicinity of the foundations to underpin systems for early warning of impending structural failure. The monitoring system consists of a probe with integrated electromagnetic sensors designed to detect changes in the dielectric permittivity of the surrounding bridge foundation. The probe is equipped with a wireless interface and was evaluated to assess its ability to detect scour and sediment deposition in various soil types and under temperature and water salinity conditions that would commonly occur in a practical installation environment. A novel methodology is also developed enabling discrimination between in situ and re-deposited sediment delivering vital information about the load bearing capacity of the foundation. The experimental approach was validated using ‘static’ scour simulations and real-time open channel flume experiments. Results indicate that the sensor is highly sensitive to underwater bed level variations and can provide an economical and accurate structural health monitoring alternative to existing instruments.

  16. Heavy Vehicles on Minor Highway Bridges

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Nielsen, Søren R. K.; Enevoldsen, I.

    Vibration of a bridge structure due to the passage of vehicles is an important consideration in the design of bridges. Further, a common problem in bridge engineering practice in these years is the upgrading of minor highway bridges (=5-20 m) to carry heavier loads partly due to a tendency...... of heavier trucks moving at larger speeds, and partly because the authorities want to permit transportation of special heavy goods at a larger part of the road net. These needs will in many cases cause the strengthening of the bridges becomes necessary. In order to keep the expenses of such strengthening...... the results obtained using the numerical models given in details in "Heavy Vehicles on Minor Highway Bridges : dynamic modelling of vehicles and bridges". The models are established using a ordinary vehicle which consists of a 48 t Scania with a 3 axle tractor and a 3 axle trailer, joined in a flexible hinge...

  17. Heavy Vehicles on Minor Highway Bridges

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Nielsen, Søren R. K.; Enevoldsen, I.

    Vibration of a bridge structure due to the passage of vehicles is an important consideration in the design of bridges. Further, a common problem in bridge engineering practice in these years is the upgrading of minor highway bridges (=5-20 m) to carry heavier loads partly due to a tendency...... of heavier trucks moving at larger speeds, and partly because the authorities want to permit transportation of special heavy goods at a larger part of the road net. These needs will in many cases cause the strengthening of the bridges becomes necessary. In order to keep the expenses of such strengthening...... the numerical models for the mathematical models of the vehicles and the bridge from which the load amplification factors can be estimated assuming that the dynamic parameters of the vehicles and the modal parameters of the bridge are known....

  18. Full-bridge capacitive extensometer

    Science.gov (United States)

    Peters, Randall D.

    1993-08-01

    Capacitive transducers have proven to be very effective sensors of small displacements, because of inherent stability and noninvasive high resolution. The most versatile ones have been those of a differential type, in which two elements are altered in opposite directions in response to change of the system parameter being monitored. Oftentimes, this differential pair has been incorporated into a bridge circuit, which is a useful means for employing synchronous detection to improve signal to noise ratios. Unlike previous differential capacitive dilatometers which used only two active capacitors, the present sensor is a full-bridge type, which is well suited to measuring low-level thermal expansions. This analog sensor is capable of 0.1 μm resolution anywhere within a range of several centimeters, with a linearity of 0.1%. Its user friendly output can be put on a strip chart recorder or directed to a computer for sophisticated data analysis.

  19. Noise Considerations in Resistance Bridges

    DEFF Research Database (Denmark)

    Diamond, Joseph M.

    1963-01-01

    thermometry, where the noise in the unknown resistor will predominate strongly. An impedance step-up device (transformer or tuned circuit) is valuable in raising the bridge signal and noise level above the noise of the first amplifier tube. However, as the step-up ratio is increased, two counterfactors appear......, namely, noise in the loss resistance of the step-up device, and grid current noise. There is therefore an optimum step-up ratio, which has been found. The step-up device is permitted to have a different temperature from the unknown and standard resistors, to evaluate the advantage of cooling it....... With certain assumptions about the noise and grid current of the first tube it is found that the equivalent temperature of a unity ratio (Mueller) bridge used for liquid helium measurements may be 400°K....

  20. Stability of Axisymmetric Liquid Bridges

    CERN Document Server

    Rubinstein, Boris

    2016-01-01

    We study stability of axisymmetric liquid bridges between two axisymmetric solid bodies in the absence of gravity under arbitrary asymmetric perturbations which are expanded into a set of angular Fourier modes. We determine the stability region boundary for every angular mode in case of both fixed and free contact lines. Application of this approach allows us to demonstrate existence of stable convex nodoid menisci between two spheres.

  1. 2015 Bridge Inspection ERC Training

    OpenAIRE

    Dougherty, Merril

    2015-01-01

    This presentation will discuss recent changes to the County Bridge Inspection Program from the perspective of both the FHWA and INDOT. We will also discuss the responsibilities of the local public agency’s (LPA’s) employee in responsible charge (ERC) with respect to managing this program. As this course is a yearly requirement, all county ERCs are encouraged to attend. Pre-registering is strongly encouraged by e-mailing your contact information to .

  2. The Bridge Program - Participant Perspectives

    OpenAIRE

    Rönnqvist, Riitta; Hakonen, Anu; Vartiainen, Matti

    2015-01-01

    The Nokia Bridge Program was established in summer 2011 in order to "make the best of the restructuring: create meaningful opportunities for individuals and local economies impacted by workforce reductions" and to "assist individuals in re-employment". This document reports whether and how the program helped individuals avoid the known negative effects of job loss and find meaningful re-employment. The document also reports how affected employees formed perceptions about Nokia´s fairness and ...

  3. Inspection Strategies for Concrete Bridges

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    1989-01-01

    In this paper an optimal inspection strategy for concrete bridges based on periodic routine and detailed inspections is presented. The failure mode considered is corrosion of the reinforcement due to chlorides. A simple modelling of the corrosion and of the inspection strategy is presented....... The optimal inspection strategy is determined from an optimization problem, where the design variables are time intervals between detailed inspections and the concrete cover. The strategy is illustrated on a simple structure, namely a reinforced concrete beam....

  4. Parabolic metamaterials and Dirac bridges

    Science.gov (United States)

    Colquitt, D. J.; Movchan, N. V.; Movchan, A. B.

    2016-10-01

    A new class of multi-scale structures, referred to as `parabolic metamaterials' is introduced and studied in this paper. For an elastic two-dimensional triangular lattice, we identify dynamic regimes, which corresponds to so-called `Dirac Bridges' on the dispersion surfaces. Such regimes lead to a highly localised and focussed unidirectional beam when the lattice is excited. We also show that the flexural rigidities of elastic ligaments are essential in establishing the `parabolic metamaterial' regimes.

  5. Severe ASR damaged concrete bridges

    DEFF Research Database (Denmark)

    Antonio Barbosa, Ricardo; Gustenhoff Hansen, Søren

    2015-01-01

    Technical University of Denmark (DTU) and University of Southern Denmark (SDU) have conducted several full-scale experiments with severe ASR deteriorated bridges. This paper presents few and preliminary results from both the shear tests and the measuring of the material properties. The shear test...... show that the shear capacity is almost unaffected of ASR despite significant reduction in compressive concrete strength. Furthermore, measurements show a significant tensile reinforcement strain developed due to ASR expansion....

  6. Halliburton Composite Bridge Plug Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Starbuck, J.M.; Luttrell, C.R.; Aramayo, G.

    2005-01-15

    The overall objectives of this CRADA were to assist Halliburton in analyzing a composite bridge plug and to determine why their original design was failing in the field. In Phase 1, finite element analyses were done on the original composite slip design and several alternative designs. The composite slip was the component in the bridge plug that was failing. The finite element code ABAQUS was used for these calculations and I-DEAS was used as the pre- and post-processor in the analyses. Several different designs and materials were analyzed and recommendations were made towards improving the design. In Phase 2, the objective was to develop finite element models that would accurately represent the deformations in the entire all-composite 4-1/2' diameter bridge plug assembly. The finite element code LS-DYNA was used and the results from this effort were intended to expand Halliburton's composite design and analysis capabilities with regard to developing future composite components for downhole tools. In addition to the finite element modeling, this effort involved the utilization of micromechanics to determine the necessary composite material properties that were needed as input for finite element codes.

  7. Nondestructive evaluation techniques for enhanced bridge inspection

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, G.; Benson, S.; Durbin, P.; Del Grande, N.; Haskins, J.; Brown, A.; Schneberk, D.

    1993-10-01

    Nondestructive evaluation of bridges is a critical aspect in the US aging infrastructure problem. For example in California there are 26,000 bridges, 3000 are made of steel, and of the steel bridges, 1000 are fracture critical. California Department of Transportation (Caltrans), Federal Highway Administration, and Lawrence Livermore National Laboratory (LLNL) are collaborating to develop and field NDE techniques to improve bridge inspections. We have demonstrated our NDE technologies on several bridge inspection applications. An early collaboration was to ultrasonically evaluate the steel pins in the E-9 pier on the San Francisco Bay Bridge. Following the Loma-Prieta earthquake in 1989 and the road way collapse at the E-9 pier, a complete nondestructive evaluation was conducted by Caltrans inspectors and several ultrasonic indications were noted. LLNL worked with Caltrans to help identify the source of these reflections. Another project was to digitally enhance high energy radiographs of bridge components such as cable end caps. We demonstrated our ability to improve the detection of corrosion and fiber breakage inside the end cap. An extension of this technology is limited view computer tomography (CT). We implemented our limited view CT software and produced cross-sectional views of bridge cables from digitized radiographic films. Most recently, we are developing dual band infrared imaging techniques to assess bridge decks for delaminations. We have demonstrated the potential of our NDE technology for enhancing the inspection of the country`s aging bridges.

  8. Protective Behaviour of Citizens to Transport Accidents Involving Hazardous Materials: A Discrete Choice Experiment Applied to Populated Areas nearby Waterways.

    Directory of Open Access Journals (Sweden)

    Esther W de Bekker-Grob

    Full Text Available To improve the information for and preparation of citizens at risk to hazardous material transport accidents, a first important step is to determine how different characteristics of hazardous material transport accidents will influence citizens' protective behaviour. However, quantitative studies investigating citizens' protective behaviour in case of hazardous material transport accidents are scarce.A discrete choice experiment was conducted among subjects (19-64 years living in the direct vicinity of a large waterway. Scenarios were described by three transport accident characteristics: odour perception, smoke/vapour perception, and the proportion of people in the environment that were leaving at their own discretion. Subjects were asked to consider each scenario as realistic and to choose the alternative that was most appealing to them: staying, seeking shelter, or escaping. A panel error component model was used to quantify how different transport accident characteristics influenced subjects' protective behaviour.The response was 44% (881/1,994. The predicted probability that a subject would stay ranged from 1% in case of a severe looking accident till 62% in case of a mild looking accident. All three transport accident characteristics proved to influence protective behaviour. Particularly a perception of strong ammonia or mercaptan odours and visible smoke/vapour close to citizens had the strongest positive influence on escaping. In general, 'escaping' was more preferred than 'seeking shelter', although stated preference heterogeneity among subjects for these protective behaviour options was substantial. Males were less willing to seek shelter than females, whereas elderly people were more willing to escape than younger people.Various characteristics of transport accident involving hazardous materials influence subjects' protective behaviour. The preference heterogeneity shows that information needs to be targeted differently depending on

  9. Comprehensive Construction Technology for All Kinds of Arch Bridges Demolition on Navigable Channel%通航河道各类拱桥拆除综合施工技术研究

    Institute of Scientific and Technical Information of China (English)

    张广义

    2016-01-01

    基于航道整治过程中老桥改建工程,介绍通航河道各类拱桥老桥拆除施工技术,着重说明不同拱桥结构类型、不同航道等级以及不同作业环境下老桥拆除施工技术的应用。通过分析上承式、中承式和下承式拱桥拆除施工中的关键工序和安全控制措施,并应用空间有限元分析程序,解决了通航河道拱桥拆除施工中的各项难题,形成了完整的拱桥拆除综合施工技术。%Based on the bridge rebuilding project during waterway regulation process,this paper makes a brief introduction of the construction technology of all kinds of old arch bridges demolition on navigable channel,emphasizes the application of old bridge demolition construction technology under different kinds of arch bridges structure,different channel levels and different working environment.Through the analysis of the key working procedure of construction and safety control meas-ures of deck-type,half through and through arch bridge,and the application of the space finite element analysis program,it solves the difficult problems during the construction of arch bridge demolition on navigable channel,and forms a compre-hensive construction technology for arch bridge demolition.

  10. Study on structural system of Sutong Bridge

    Institute of Scientific and Technical Information of China (English)

    Zhang Xigang; Pei Minshan; Yuan Hong; Xu Liping; Zhu Bin

    2009-01-01

    Sutong Bridge, whose layout is [ (100 + 100 + 300) + 1 088 + ( 300 + 100 + 100) ] m, marks the largest span of cable-stayed bridges in the world. The complex natural condition at the bridge site and the strict requirements for resistance of wind and seismic action make it crucial to choose a favorable structural system to assure the function and safety of the bridge. The comparison among several optional structural systems for Sutong Bridge is illustrated. After detailed analysis is carried out for viscous damper and hydraulic buffer, super liquid viscous damper with additional displacement limitation is designed for the first application in bridge engineering. The parameters for the damper is analyzed and studied and the dampers are installed suecessfuUy after quality tests.

  11. Evaluation method research on prestressed concrete bridges

    Institute of Scientific and Technical Information of China (English)

    HUANG Qiao; LIN Yang-zi; REN Yuan

    2008-01-01

    Considering the construction features of prestressed concrete bridge, the comprehensive evaluation method about the bridge damage conditions are studied. Particular attentions are paid on establishing a multi-level evaluation model for damaged prestressed concrete bridge, and the evaluation indices of the model as well as the rating standards are defined in the model. A normal relative function about the evaluation indices of each element is developed to calculate the relative degree, and for each element which is no sub-level elements. When evaluating the elements in sub-item level or index level of the model, the weights of elements that are pertained to one element are adopted, taking account of their deterioration degree. At the same time, the dam-age conditions of bridge are characterized by relative degree, element evaluation scale and structural technology mark of bridge ,so it agrees with Code for Maintenance of Highway Bridges and Culvers.

  12. Seismic Evaluation of Highway Bridges - Phase 1

    OpenAIRE

    Ramirez, J.A.; Pan, Austin D.; Mwakasisi, Frank Thompson

    1996-01-01

    The primary objective of the study was to establish the guidelines for screening, assessing, and ranking Indiana bridges for seismic upgrade. The outcome of the study is a complete strategy for the detailed structural assessment of Indiana highway bridges subjected to seismic forces. The structural evaluation is conducted using a nonlinear time-history analysis of the bridge for simulated or actual records. The specific soil conditions at the site are accounted in terms of the ground motio...

  13. REPORT: BioMedBridges standards workshop

    OpenAIRE

    Conte, Nathalie; Hancocks, Tom; Suhr, Stephanie

    2014-01-01

    This workshop, co-organized by BioMedBridges WP3 and 12, was held on 24-25 June and hosted by BioMedBridges partners at VUMC in Amsterdam. Attendees included BioMedBridges personnel, members from the ESFRI BMS research infrastructures and invited external experts from existing standards organisations. The following aspects of data standardisation were explored: Defining entity identifiers and identifiers best practice Development of a Meta models and Mappings Registry for bio...

  14. Analysis of liquid bridge between spherical particles

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A pair of central moving spherical particles connected by a pendular liquid bridge with interstitial Newtonian fluid is often encountered in pariculate coalescence process. In this paper, by assuming perfect-wet condition, the effects of liquid volume and separation distance on static liquid bridge are analyzed, and the relation between rupture energy and liquid bridge volume is also studied. These points would be of significance in industrial processes related to adhesive particles.

  15. Bridge engineering handbook construction and maintenance

    CERN Document Server

    Chen, Wai-Fah

    2014-01-01

    Over 140 experts, 14 countries, and 89 chapters are represented in the second edition of the Bridge Engineering Handbook. This extensive collection highlights bridge engineering specimens from around the world, contains detailed information on bridge engineering, and thoroughly explains the concepts and practical applications surrounding the subject.Published in five books: Fundamentals, Superstructure Design, Substructure Design, Seismic Design, and Construction and Maintenance, this new edition provides numerous worked-out examples that give readers step-by-step design procedures, includes c

  16. Markovian Bridges: Weak continuity and pathwise constructions

    OpenAIRE

    Chaumont, Loïc; Uribe Bravo, Gerónimo

    2009-01-01

    A Markovian bridge is a probability measure taken from a disintegration of the law of an initial part of the path of a Markov process given its terminal value. As such, Markovian bridges admit a natural parameterization in terms of the state space of the process. In the context of Feller processes with continuous transition densities, we construct by weak convergence considerations the only versions of Markovian bridges which are weakly continuous with respect to their parameter. We use this ...

  17. Life Cycle Assessment of a Norwegian Bridge

    OpenAIRE

    Dequidt, Thomas Charles Edouard

    2012-01-01

    Life cycle assessment (LCA) methodology aims at evaluating the environmental impacts of a product or system from a holistic approach. In this methodology, all life cycle phases of the product are identified and assessed, from the raw material acquisition to the end-of-life phase. This master thesis is dealing with the LCA of a Norwegian bridge. First, a literature review is realized by going through 14 bridge LCA references. Then, a detailed description of bridge LCA methodology ...

  18. Bridge Engineering-Oriented Parametric Model

    Institute of Scientific and Technical Information of China (English)

    周凌远; 李乔

    2004-01-01

    A new model is proposed to improve the efficiency of structural modeling. In this model, the bridge structural components are expressed with component description, parametric description and geometric description in a software system. This model provides both convenience and flexibility for users in structural modeling process. The object-oriented method is applied in the model implementation. A bridge analysis preprocessor is developed on the basis of this model. It provides an effective way for bridge modeling.

  19. Dynamics and Statics of Nonaxisymmetric Liquid Bridges

    Science.gov (United States)

    Alexander, J. Iwan D.; Resnick, Andrew H.; Slobozhanin, L. A.

    1996-01-01

    Theoretical and experimental investigation of the stability of nonaxisymmetric and nonaxisymmetric bridges contained between equal and unequal radii disks as a function of Bond and Weber number with emphasis on the transition from unstable axisymmetric to stable nonaxisymmetric shapes, are conducted. Numerical analysis of the stability of nonaxisymmetric bridges between unequal disks for various orientations of the gravity vector is performed. Experimental and theoretical investigation of large (nonaxisymmetric) oscillations and breaking of liquid bridges are also conducted.

  20. Maximal liquid bridges between horizontal cylinders

    OpenAIRE

    Cooray, Himantha; Huppert, Herbert E.; Neufeld, Jerome A

    2016-01-01

    We investigate two-dimensional liquid bridges trapped between pairs of identical horizontal cylinders. The cylinders support forces due to surface tension and hydrostatic pressure which balance the weight of the liquid. The shape of the liquid bridge is determined by analytically solving the nonlinear Laplace-Young equation. Parameters that maximize the trapping capacity (defined as the cross-sectional area of the liquid bridge) are then determined. The results show that these parameters can ...

  1. Axisymmetric long liquid bridges stability and resonances

    OpenAIRE

    Meseguer Ruiz, José; Sanz Andres, Angel Pedro; Perales Perales, José Manuel

    1990-01-01

    In this paper mathematical expressions for minimum-volume stability limits and resonance frequencies of axisymmetric long liquid bridges are presented. These expressions are valid for a wide range of liquid bridge configurations, accounting for ef-fects like unequal disks and axial microgravity in the case of minimum-volume stability limits,and unequal disks, axial microgravity,non-zero viscosity and liquid bridge volume different from the cylindrical one in the case of resonance frequenc...

  2. Crystal growth under bridge foundation

    OpenAIRE

    Ramon Tarragona, Anna; Alonso Pérez de Agreda, Eduardo

    2012-01-01

    W(H)YDOC PhD Prize 2012, durant el 4th International Workshop of Young Doctors in Geomechanics W(H)YDOC 2012. A high-speed railway viaduct experienced a sustained heave at high rates after its construction. The pillars of the bridge are founded on an Eocene hard anhydritic-gypsiferous claystone by means of massive foundations. Field investigations identified an active layer below the piles’ tips where expansions occur as a result of gypsum crystal growth in discontinuities from supersatura...

  3. Nanoclusters a bridge across disciplines

    CERN Document Server

    Jena, Purusottam

    2010-01-01

    This comprehensive book on Nanoclusters comprises sixteen authoritative chapters written by leading researchers in the field. It provides insight into topics that are currently at the cutting edge of cluster science, with the main focus on metal and metal compound systems that are of particular interest in materials science, and also on aspects related to biology and medicine. While there are numerous books on clusters, the focus on clusters as a bridge across disciplines sets this book apart from others. Delivers cutting edge coverage of cluster science Covers a broad range of topics in

  4. Family Medicine: Bridge to Life.

    Science.gov (United States)

    Luz, Clare

    2016-01-01

    Reflecting on the suicide of a close friend, this essay explores what comprises, and inspires a will to live, and how those in Family Medicine can address suicide risk even in the face of debilitating or terminal illness. Research indicates that the will to live is a measurable indicator of general well-being, distinct from depression, and an important predictor of a person's motivation to "hold on to life". As such, understanding what is at the heart of a desire to live should alter clinical practice. This essay offers ideas for ways in which to create bridges for patients that could help sustain life.

  5. A bridge to advanced mathematics

    CERN Document Server

    Sentilles, Dennis

    2011-01-01

    This helpful workbook-style ""bridge"" book introduces students to the foundations of advanced mathematics, spanning the gap between a practically oriented calculus sequence and subsequent courses in algebra and analysis with a more theoretical slant. Part 1 focuses on logic and number systems, providing the most basic tools, examples, and motivation for the manner, method, and concerns of higher mathematics. Part 2 covers sets, relations, functions, infinite sets, and mathematical proofs and reasoning. Author Dennis Sentilles also discusses the history and development of mathematics as well a

  6. Myocardial bridges: morphological and functional aspects.

    OpenAIRE

    A.G. Ferreira; Trotter, S E; König, B; Décourt, L V; Fox, K; Olsen, E G

    1991-01-01

    OBJECTIVE--To assess the arrangement of myocardial bridges. DESIGN--A necropsy study of 90 consecutive hearts (56 male, 34 female). RESULTS--Myocardial bridges, either single or multiple, were seen in 50 (55.6%) of the 90 hearts. The left anterior descending artery was the most commonly affected artery. Thirty five of the 50 hearts which contained in total 41 muscle bridges were dissected further with a magnifying glass. Two different types of muscle bridges could be identified. Thirty one of...

  7. A data management infrastructure for bridge monitoring

    Science.gov (United States)

    Jeong, Seongwoon; Byun, Jaewook; Kim, Daeyoung; Sohn, Hoon; Bae, In Hwan; Law, Kincho H.

    2015-04-01

    This paper discusses a data management infrastructure framework for bridge monitoring applications. As sensor technologies mature and become economically affordable, their deployment for bridge monitoring will continue to grow. Data management becomes a critical issue not only for storing the sensor data but also for integrating with the bridge model to support other functions, such as management, maintenance and inspection. The focus of this study is on the effective data management of bridge information and sensor data, which is crucial to structural health monitoring and life cycle management of bridge structures. We review the state-of-the-art of bridge information modeling and sensor data management, and propose a data management framework for bridge monitoring based on NoSQL database technologies that have been shown useful in handling high volume, time-series data and to flexibly deal with unstructured data schema. Specifically, Apache Cassandra and Mongo DB are deployed for the prototype implementation of the framework. This paper describes the database design for an XML-based Bridge Information Modeling (BrIM) schema, and the representation of sensor data using Sensor Model Language (SensorML). The proposed prototype data management framework is validated using data collected from the Yeongjong Bridge in Incheon, Korea.

  8. Review of Energy Harvesters Utilizing Bridge Vibrations

    Directory of Open Access Journals (Sweden)

    Farid Ullah Khan

    2016-01-01

    Full Text Available For health monitoring of bridges, wireless acceleration sensor nodes (WASNs are normally used. In bridge environment, several forms of energy are available for operating WASNs that include wind, solar, acoustic, and vibration energy. However, only bridge vibration has the tendency to be utilized for embedded WASNs application in bridge structures. This paper reports on the recent advancements in the area of vibration energy harvesters (VEHs utilizing bridge oscillations. The bridge vibration is narrowband (1 to 40 Hz with low acceleration levels (0.01 to 3.8 g. For utilization of bridge vibration, electromagnetic based vibration energy harvesters (EM-VEHs and piezoelectric based vibration energy harvesters (PE-VEHs have been developed. The power generation of the reported EM-VEHs is in the range from 0.7 to 1450000 μW. However, the power production by the developed PE-VEHs ranges from 0.6 to 7700 μW. The overall size of most of the bridge VEHs is quite comparable and is in mesoscale. The resonant frequencies of EM-VEHs are on the lower side (0.13 to 27 Hz in comparison to PE-VEHs (1 to 120 Hz. The power densities reported for these bridge VEHs range from 0.01 to 9539.5 μW/cm3 and are quite enough to operate most of the commercial WASNs.

  9. Gust loading on streamlined bridge decks

    DEFF Research Database (Denmark)

    Larose, Guy; Mann, Jakob

    1998-01-01

    The current analytical description of the buffeting action of wind on long-span bridges is based on the strip assumption. However, recent experiments on closed-box girder bridge decks have shown that this assumption is not valid and is the source of an important part of the error margin of the an......The current analytical description of the buffeting action of wind on long-span bridges is based on the strip assumption. However, recent experiments on closed-box girder bridge decks have shown that this assumption is not valid and is the source of an important part of the error margin...

  10. 49 CFR 237.101 - Scheduling of bridge inspections.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Scheduling of bridge inspections. 237.101 Section... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.101 Scheduling of bridge inspections. (a) Each bridge management program shall include a provision for scheduling...

  11. Finite element of multilayer surfacing systems on orthotropic steel bridges

    NARCIS (Netherlands)

    Li, J.; Liu, X.; Scarpas, A.; Tzimiris, G.

    2013-01-01

    Light weight orthotropic steel bridge decks have been widely utilized for bridges in seismic zones, movable bridges and long span bridges. In the last three decades, severe problems were reported in relation to asphaltic surfacing materials on orthotropic steel deck bridges. Earlier investigations h

  12. 内河航道采砂监测系统设计及应用%Design and Application of Sand Mining Monitoring System for Inland River Waterway

    Institute of Scientific and Technical Information of China (English)

    高健; 陈先桥; 初秀民; 尹奇志

    2013-01-01

    Illegal sand mining activities affect the natural variation of river bed in sand mined river,and they are harmful to flood control safety,navigation safety and ecological environment.In this paper,on the basis of analyzing the development and current situation about sand monitoring technology,information technology in Yangtze River waterway,the automatic acquisition and recognition method of sand mining area,sand quantity,sand area waterway structure were studied.And the design scheme of real -time monitoring system for the Yangtze River Waterway sand mining was proposed.The practical application shows that it has achieved good social and economic benefits.Based on the sand mining monitoring system design scheme and the introduced key processing technology,it will improve the service quality and the traffic capacity in inland waterway.%针对违法违规采砂活动严重影响采砂河段河床的自然变化,对采砂河段的防洪安全、船舶航行安全及生态环境等都带来不良影响的问题,在查阅国内外大量文献的基础上,分析了国内外采砂监管技术发展现状、重点河道的采砂监管现状、长江航道监控信息化技术现状,研究了采砂区域、采砂量、采砂区域航道结构信号的自动采集和识别方法,给出了长江航道采砂实时监测系统设计方案.实际应用表明,根据该设计方案和关键处理技术研制的长江航道采砂远程监控系统应用效果良好,取得了较好的社会和经济效益,对提高内河航道服务品质及内河航道通行能力起到了重要的促进作用.

  13. The Bridge of Mandolin County

    Science.gov (United States)

    Lantz, Juliette M.; Feindt, Jenny E.; Lewellyn, Eric P. B.; Walczak, Mary M.

    1999-12-01

    The Bridge of Mandolin County is a case designed to teach the general chemistry principles of molar mass, ions and aqueous reactions, solubility rules, and inorganic nomenclature. Through the instructor-facilitated class discussion, students consider the options before the Mandolin Town Council regarding deicing the newly constructed bridge connecting Mandolin with a large nearby city. The students must decipher contradictory claims made on behalf of sodium chloride, the traditional deicer, and calcium magnesium acetate, a new environmentally friendly deicer, to arrive at the most cost-effective and environmentally appropriate deicing product. As they work through the analysis they raise questions that can be addressed in a laboratory setting. Four optional role-playing experiments are included, which can be used by the students to gather information helpful to resolution of the case. The case is intended to be used over two class periods, with a laboratory period in between, though suggestions for other models are provided. Laboratory procedures include an EDTA titration for Ca2+ and Mg2+, a gravimetric analysis, a qualitative examination of ions and solubility, an introduction to freezing point depression and measurement, and an experimental design activity. This case can also successfully be used without alteration in non-majors chemistry or environmental chemistry courses, or upper-level analytical or environmental chemistry courses.

  14. Application of Kalman filter to short-term tide level prediction by Yen, P.-H., Jan, C.-D., Lee, Y.-P. and Lee, H.-F. (J. Waterway Port Coast. Ocean Eng. 122(5); 1996; pp 226-231: Discussion

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.; Chandramohan, P

    stream_size 2 stream_content_type text/plain stream_name J_Waterway_Port_Coast_Eng_124_213.pdf.txt stream_source_info J_Waterway_Port_Coast_Eng_124_213.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  15. Bridge Lock-up Device System

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    The Colebrand Lock-up Device (LUD) provides additional substructure strength to resist seismic forces as a structural shock transmission unit for highway bridges. This system can provide a temporary rigid link between bridge structural members under seismic, braking, or other fast-acting type loads, while permitting slow thermal movements.

  16. Paul Dirac:. Building Bridges of the Mind

    Science.gov (United States)

    Brown, Laurie M.

    2003-12-01

    Paul Dirac was a brilliant and original thinker. He used his physical intuition and his ideal of mathematical beauty to construct bridges between major areas of physics. This article discusses several such important works, including the bridge between quantum mechanics and relativity that led to his prediction of the existence of antimatter.

  17. History of cable-stayed bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

    The principle of supporting a bridge deck by inclined tension members leading to towers on either side of the span has been known for centuries. However, the real development of cable-stayed bridges did not begin before the 1950s. Since then the free span has been increased from 183 m in the Strö...

  18. COUPLING VIBRATION OF VEHICLE-BRIDGE SYSTEM

    Institute of Scientific and Technical Information of China (English)

    陈炎; 黄小清; 马友发

    2004-01-01

    By applying the sinusoidal wave mode to simulate the rugged surface of bridge deck,accounting for vehicle-bridge interaction and using Euler-Bernoulli beam theory, a coupling vibration model of vehicle-bridge system was developed. The model was solved by mode analyzing method and Runge-Kutta method, and the dynamic response and the resonance curve of the bridge were obtained. It is found that there are two resonance regions, one represents the main resonance while the other the minor resonance, in the resonance curve. The influence due to the rugged surface, the vibration mode of bridge, and the interaction between vehicle and bridge on vibration of the system were discussed. Numerical results show that the influence due to these parameters is so significant that the effect of roughness of the bridge deck and the mode shape of the bridge can't be ignored and the vehicle velocity should be kept away from the critical speed of the vehicle.

  19. A STUDY OF BARRIERS IN BRIDGING COMMUNICATION

    OpenAIRE

    Niteen V. Dandekar

    2014-01-01

    The main objective of this paper is to make a thought provoking discussion on the role barriers in bridging communication. It focuses on the concept of communication, process and the role of language related barriers in bridging communication. It studies the significance of communication in modern human life.

  20. General framework for bridge life cycle design

    Institute of Scientific and Technical Information of China (English)

    Junhai MA; Airong CHEN; Jun HE

    2009-01-01

    Based on a detailed illustration for bridge life cycle design which comprises the processes of service life design, aesthetics design, performance design, environ-mental and ecological design, inspection, maintenance and repair design as well as cost analysis, this paper presented a general framework for bridge life cycle design comprising three design phases and six design processes.

  1. Active aerodynamic stabilisation of long suspension bridges

    DEFF Research Database (Denmark)

    Nissen, Henrik Ditlev; Sørensen, Paul Haase; Jannerup, Ole Erik

    2004-01-01

    The paper describes the addition of actively controlled appendages (flaps) attached along the length of the bridge deck to dampen wind-induced oscillations in long suppension bridges. A novel approach using control systems methods for the analysis of dynamic stability is presented. In order to ma...

  2. Lifetime Reliability Assessment of Concrete Slab Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    A procedure for lifetime assesment of the reliability of short concrete slab bridges is presented in the paper. Corrosion of the reinforcement is the deterioration mechanism used for estimating the reliability profiles for such bridges. The importance of using sensitivity measures is stressed...

  3. Re-Assessment of Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper two aspects of re-assessment of the reliability of concrete bridges are discussed namely modelling of the corrosion of reinforcement and updating of uncertain variables. The main reason for deterioration of concrete bridges is corrosion of the reinforcement. Therefore, modelling...

  4. Optimum Maintenance Strategies for Highway Bridges

    DEFF Research Database (Denmark)

    Frangopol, Dan M.; Thoft-Christensen, Palle; Das, Parag C.;

    As bridges become older and maintenance costs become higher, transportation agencies are facing challenges related to implementation of optimal bridge management programs based on life cycle cost considerations. A reliability-based approach is necessary to find optimal solutions based on minimum ...... is described. The end result of this investigation will be a general reliability-based framework to be used by the UK Highways Agency in order to plan optimal strategies for the maintenance of its bridge network so as to optimize whole-life costs....... expected life-cycle costs or maximum life-cycle benefits. This is because many maintenance activities can be associated with significant costs, but their effects on bridge safety can be minor. In this paper, the program of an investigation on optimum maintenance strategies for different bridge types...

  5. The I-35W bridge Project Website

    DEFF Research Database (Denmark)

    Kampf, Constance

    How can websites be used to rebuild trust?  In August 2007, the Interstate Highway 35-W bridge in Minneapolis, MN collapsed during rush hour.  Although many people were rescued and casualties were as limited as could be expected due to quick and effective intervention, the image of a major bridge...... collapsing during rush hour damaged the Minnesota Department of Transportation's reputation and resulted in the loss of public trust for the organization.  The ensuing bridge reconstruction project included a project website intended to rebuild this trust through transparency, community involvement......, and the use of multimodal features.  This paper looks at the I35-W bridge reconstruction project in Minneapolis through web-based communication by the Minnesota Department of Transportation (MnDOT) about the project. The MnDOT bridge reconstruction website will be examined using a combination of 1). Weick...

  6. 环北极国家与地区的北极航道通行政策及其发展趋势分析%STUDY OF ARCTIC WATERWAY TRANSIT POLICY AND ITS DEVELOPMENT ON CIRCUMPOLAR NATIONS AND REGIONS

    Institute of Scientific and Technical Information of China (English)

    王丹; 王杰; 张浩

    2015-01-01

    Global warming has accelerated and the speed of melting of the Arctic sea ice has increased, which means that the Arctic’ s waterways will be opened much earlier than originally expected.Therefore, the transportation value of Arctic waterways has become increasingly prominent, which has prompted Circumpolar Nations to propose various policies and claims regarding Arctic waterway transit.Although China is not an Arctic state, the availability of an Arctic waterway could shorten international shipping routes, reducing the time and cost of foreign trade, and de-creasing the risks of piracy and terrorism.Therefore, to maintain the potential benefits of Arctic waterways to Chi-na, attention should be given to this problem.In this paper, the origins of the problems pertaining to the Arctic wa-terway are introduced, the policies proposed by Russia, Canada, the United States, and the European Union re-garding Arctic waterway transit are elaborated, and the trend of development of Arctic waterway transit policy is an-alyzed.%全球变暖加快了北冰洋融化的速度,从而使得北极航道全面开通的时间将比预期大大提前,北极航道的交通价值也日益凸显。在这种情况下,环北极国家与地区纷纷提出了对北极航道通行的政策和主张。中国虽不是环北极国家,但北极航道能缩短中国国际贸易的海运距离,节约货物海上运输的时间和成本,并降低传统航线的海盗和恐怖主义袭击风险,所以从维护中国在北极航道通行问题上的“潜在利益”的角度出发,中国应该加强对北极航道通行问题的关注。本文首先介绍了北极航道问题的由来,逐一阐述了俄罗斯、加拿大、美国和欧盟在北极航道通行问题上的政策和主张,最后分析了北极航道通行政策的发展趋势。

  7. Modified Geometry of Transition Slabs for Integral Bridges

    OpenAIRE

    Dreier, Damien

    2010-01-01

    Over the past decades, an increasing number of integral bridges have been built. This type of bridge offers various advantages in comparison with standard bridges equipped with expansion joints and bearings. In particular, integral bridges require less maintenance since they require less mechanical elements. Transition slabs, which are used in integral bridges, are directly connected to the bridge deck and therefore they are subjected to large displacements caused by creep, shrinkage and temp...

  8. Building bridges … and accelerators

    CERN Multimedia

    2009-01-01

    Lyn Evans, the LHC project leader, was awarded an honorary doctorate from the University of Geneva (UNIGE) to celebrate his role not just in building accelerators, but also in building bridges between nations. He was one of four notables honoured at the event on Friday 5 June, coinciding with the University’s 450th Anniversary. Lyn Evans arriving at the ceremony with Archbishop Desmond Tutu. "It was a big surprise when I found out I’d been nominated," recounts Evans, "but it was an even bigger surprise to find out with whom I’d been nominated". At the ceremony Evans was awarded the honorary doctorate along with three others: Archbishop Desmond Tutu, who was acclaimed for his fight against apartheid in South Africa, Mary Robinson, first woman president of Ireland and former United Nations’ high commissioner of human rights, and Pascal Lamy, Director-General of the World Trade Organization. The award ceremony, known as the �...

  9. Root coverage with bridge flap

    Directory of Open Access Journals (Sweden)

    Pushpendra Kumar Verma

    2013-01-01

    Full Text Available Gingival recession in anterior teeth is a common concern due to esthetic reasons or root sensitivity. Gingival recession, especially in multiple anterior teeth, is of huge concern due to esthetic reasons. Various mucogingival surgeries are available for root coverage. This case report presents a new bridge flap technique, which allows the dentist not only to cover the previously denuded root surfaces but also to increase the zone of attached gingiva at a single step. In this case, a coronally advanced flap along with vestibular deepening technique was used as root coverage procedure for the treatment of multiple recession-type defect. Here, vestibular deepening technique is used to increase the width of the attached gingiva. The predictability of this procedure results in an esthetically healthy periodontium, along with gain in keratinized tissue and good patient′s acceptance.

  10. Predicted effects on ground water of construction of Divide Cut section, Tennessee-Tombigbee Waterway, northeastern Mississippi, using a digital model

    Science.gov (United States)

    McBride, Mark S.

    1981-01-01

    The Tennessee-Tombigbee Waterway, connecting the Tennessee River in northeastern Mississippi with the Gulf of Mexico, is currently (1980) under construction. The Divide Section, the northernmost 39 miles of the Waterway, will consist, from north to south, of (1) a dredged channel, (2) the Divide Cut, and (3) an artifical lake impounded by the Bay Springs Dam. In all three , water will be at Tennessee River level. A three-dimensional digital model covering 3,273 square miles was constructed to simulate ground-water flow in the Gordo and Eutaw Formations and the Coffee Sand in the vicinity of the Divide Section. The model was calibrated to preconstruction water levels, then used to simulate the effects of stresses imposed by the construction of the Divide Section. The model indicates that the system stabilizes after major changes in conditions within a few months. The Divide Cut acts as a drain, lowering water levels as much as 55 feet. Drawdowns of 5 feet occur as much as 8 miles from the Cut. The 80-foot-high Bay Springs Dam raises ground-water levels by 5 feet as far as 6 miles from its impoundment. Drawdown is not likely to affect public water supplies significantly, but probably will adversely affect a relatively small number of private wells. (USGS)

  11. An Endangered Arboreal Specialist, the Western Ringtail Possum (Pseudocheirus occidentalis, Shows a Greater Genetic Divergence across a Narrow Artificial Waterway than a Major Road.

    Directory of Open Access Journals (Sweden)

    Kaori Yokochi

    Full Text Available The fragmentation of habitats by roads and other artificial linear structures can have a profound effect on the movement of arboreal species due to their strong fidelity to canopies. Here, we used 12 microsatellite DNA loci to investigate the fine-scale spatial genetic structure and the effects of a major road and a narrow artificial waterway on a population of the endangered western ringtail possum (Pseudocheirus occidentalis in Busselton, Western Australia. Using spatial autocorrelation analysis, we found positive genetic structure in continuous habitat over distances up to 600 m. These patterns are consistent with the sedentary nature of P. occidentalis and highlight their vulnerability to the effects of habitat fragmentation. Pairwise relatedness values and Bayesian cluster analysis also revealed significant genetic divergences across an artificial waterway, suggesting that it was a barrier to gene flow. By contrast, no genetic divergences were detected across the major road. While studies often focus on roads when assessing the effects of artificial linear structures on wildlife, this study provides an example of an often overlooked artificial linear structure other than a road that has a significant impact on wildlife dispersal leading to genetic subdivision.

  12. An Endangered Arboreal Specialist, the Western Ringtail Possum (Pseudocheirus occidentalis), Shows a Greater Genetic Divergence across a Narrow Artificial Waterway than a Major Road.

    Science.gov (United States)

    Yokochi, Kaori; Kennington, Winn Jason; Bencini, Roberta

    2016-01-01

    The fragmentation of habitats by roads and other artificial linear structures can have a profound effect on the movement of arboreal species due to their strong fidelity to canopies. Here, we used 12 microsatellite DNA loci to investigate the fine-scale spatial genetic structure and the effects of a major road and a narrow artificial waterway on a population of the endangered western ringtail possum (Pseudocheirus occidentalis) in Busselton, Western Australia. Using spatial autocorrelation analysis, we found positive genetic structure in continuous habitat over distances up to 600 m. These patterns are consistent with the sedentary nature of P. occidentalis and highlight their vulnerability to the effects of habitat fragmentation. Pairwise relatedness values and Bayesian cluster analysis also revealed significant genetic divergences across an artificial waterway, suggesting that it was a barrier to gene flow. By contrast, no genetic divergences were detected across the major road. While studies often focus on roads when assessing the effects of artificial linear structures on wildlife, this study provides an example of an often overlooked artificial linear structure other than a road that has a significant impact on wildlife dispersal leading to genetic subdivision. PMID:26784921

  13. Oscillations in a sunspot with light bridges

    CERN Document Server

    Yuan, Ding; Huang, Zhenghua; Li, Bo; Su, Jiangtao; Yan, Yihua; Tan, Baolin

    2014-01-01

    Solar Optical Telescope onboard Hinode observed a sunspot (AR 11836) with two light bridges (LBs) on 31 Aug 2013. We analysed a 2-hour \\ion{Ca}{2} H emission intensity data set and detected strong 5-min oscillation power on both LBs and in the inner penumbra. The time-distance plot reveals that 5-min oscillation phase does not vary significantly along the thin bridge, indicating that the oscillations are likely to originate from the underneath. The slit taken along the central axis of the wide light bridge exhibits a standing wave feature. However, at the centre of the wide bridge, the 5-min oscillation power is found to be stronger than at its sides. Moreover, the time-distance plot across the wide bridge exhibits a herringbone pattern that indicates a counter-stream of two running waves originated at the bridge sides. Thus, the 5-min oscillations on the wide bridge also resemble the properties of running penumbral waves. The 5-min oscillations are suppressed in the umbra, while the 3-min oscillations occupy...

  14. Track-Bridge Longitudinal Interaction of Continuous Welded Rails on Arch Bridge

    Directory of Open Access Journals (Sweden)

    Rong Chen

    2013-01-01

    Full Text Available Taking arch bridges, including deck, half-through, and through arch bridges (short for DAB, HTAB, and TAB as examples, mechanics analysis models of longitudinal interaction between continuously welded rails (short for CWRs and arch bridges are established. Based on the finite element method (FEM, the longitudinal interaction calculation software of CWR on arch bridges has been developed. Focusing on an HTAB, the tension, compression, and deflection conditions are calculated and analyzed. The results show that the mechanics analysis models of three types of arch bridges can truly reflect the real state of the structure; the calculation software can be used for systematic research of the CWR on arch bridge; as for HTAB, temperature difference of arch rib has a small effect on rail tension/compression, and arch bridge can be simplified as a continuous beam for rail tension/compression additional force calculation; in calculation of deflection conditions of HTAB, it is suggested that train loads are arranged on half span and full span and take the direction of load entering bridge into account. Additionally, the deflection additional force variation of CFST basket handle arch bridge is different from that of ordinary bridge.

  15. Signal and noise in bridging PCR

    Directory of Open Access Journals (Sweden)

    Thaler David S

    2002-07-01

    Full Text Available Abstract Background In a variant of the standard PCR reaction termed bridging, or jumping, PCR the primer-bound sequences are originally on separate template molecules. Bridging can occur if, and only if, the templates contain a region of sequence similarity. A 3' end of synthesis in one round of synthesis that terminates in this region of similarity can prime on the other. In principle, Bridging PCR (BPCR can detect a subpopulation of one template that terminates synthesis in the region of sequence shared by the other template. This study considers the sensitivity and noise of BPCR as a quantitative assay for backbone interruptions. Bridging synthesis is also important to some methods for computing with DNA. Results In this study, BPCR was tested over a 328 base pair segment of the E. coli lac operon and a signal to noise ratio (S/N of approximately 10 was obtained under normal PCR conditions with Taq polymerase. With special precautions in the case of Taq or by using the Stoffel fragment the S/N was improved to 100, i.e. 1 part of cut input DNA yielded the same output as 100 parts of intact input DNA. Conclusions In the E. coli lac operator region studied here, depending on details of protocol, between 3 and 30% per kilobase of final PCR product resulted from bridging. Other systems are expected to differ in the proportion of product that is bridged consequent to PCR protocol and the sequence analyzed. In many cases physical bridging during PCR will have no informational consequence because the bridged templates are of identical sequence, but in a number of special cases bridging creates, or, destroys, information.

  16. Human Errors and Bridge Management Systems

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Nowak, A. S.

    Human errors are divided in two groups. The first group contains human errors, which effect the reliability directly. The second group contains human errors, which will not directly effect the reliability of the structure. The methodology used to estimate so-called reliability distributions...... on basis of reliability profiles for bridges without human errors are extended to include bridges with human errors. The first rehabilitation distributions for bridges without and with human errors are combined into a joint first rehabilitation distribution. The methodology presented is illustrated...

  17. Building the Clinical Bridge: An Australian Success

    Directory of Open Access Journals (Sweden)

    Marianne Wallis

    2012-01-01

    Full Text Available Nursing effectiveness science includes primary, secondary, and translational, clinically focused research activities which aim to improve patient or client outcomes. It is imperative, for the successful conduct of a program of nursing effectiveness science, that a clinical bridge is established between academic and healthcare service facilities. An Australian example of the development of a robust clinical bridge through the use of jointly funded positions at the professorial level is outlined. In addition, an analysis of the practical application of Lewin’s model of change management and the contribution of both servant and transformational leadership styles to the bridge building process is provided.

  18. Building the clinical bridge: an Australian success.

    Science.gov (United States)

    Wallis, Marianne; Chaboyer, Wendy

    2012-01-01

    Nursing effectiveness science includes primary, secondary, and translational, clinically focused research activities which aim to improve patient or client outcomes. It is imperative, for the successful conduct of a program of nursing effectiveness science, that a clinical bridge is established between academic and healthcare service facilities. An Australian example of the development of a robust clinical bridge through the use of jointly funded positions at the professorial level is outlined. In addition, an analysis of the practical application of Lewin's model of change management and the contribution of both servant and transformational leadership styles to the bridge building process is provided.

  19. Maxwell Tension Supports the Water Bridge

    OpenAIRE

    Widom, A.; Srivastava, Y. N.; Swain, J.; Sivasubramanian, S.

    2008-01-01

    A cylindrical flexible cable made up of pure fluid water can be experimentally spanned across a spatial gap with cable endpoints fixed to the top edges of two glass beakers. The cable has been called a water bridge in close analogy to iron cables employed to build ordinary span bridges. A necessary condition for the construction of a water bridge is that a large electric field exists parallel to and located within the water cable. Presently, there is no accepted detailed theory which quantita...

  20. Pilot testing of a hydraulic bridge exciter

    OpenAIRE

    Andersson Andreas; Ülker-Kaustell Mahir; Borg Richard; Dymén Olivier; Carolin Anders; Karoumi Raid

    2015-01-01

    This paper describes the development of a hydraulic bridge exciter and its first pilot testing on a full scale railway bridge in service. The exciter is based on a hydraulic load cylinder with a capacity of 50 kN and is intended for controlled dynamic loading up to at least 50 Hz. The load is applied from underneath the bridge, enabling testing while the railway line is in service. The system is shown to produce constant load amplitude even at resonance. The exciter is used to experimentally ...

  1. Very long term development of the Dutch Inland Waterway Transport System: Policy analysis, transport projections, shipping scenarios, and a new perspective on economic growth and future discounting: Extended summary report

    NARCIS (Netherlands)

    Van Dorsser, J.C.M.

    2015-01-01

    This report, that provides an extended summary of a similar named thesis, addresses how a new method for the evaluation of policies with a very long term impact on the Dutch Inland Waterway Transport (IWT) system can be developed. It proposes an outline for a very long term transport model, prepares

  2. How ship wave action influences the sediment budget of a nature friendly bank protection in a confined, non-tidal waterway

    Science.gov (United States)

    De Roo, S.; Vanhaute, L.; Troch, P.

    2012-04-01

    Failure of the concrete slab revetment resulted in progressive bank erosion along the Lys (Belgium), a confined, non-tidal waterway subject to heavy shipping traffic. In an attempt to reconcile both the technical and environmental requirements related to a river bank, restoration was carried out using a more ecologically sound, 'soft' engineering method. A nature friendly bank protection, consisting of off-bank timber piling in combination with (reed)vegetation in the shallow water zone behind, was installed. As a consequence of this effort towards a more sustainable and ecological design of the waterway, sediment redistribution and transport processes are however altered distinctly. Being a waterway subject to heavy shipping traffic (on monthly average 1700 ship passages), hydrodynamic ship wave action on this open, semi-natural bank protection also induces sediment (re)suspension and acts as a main contributor to sediment transport (in normal weather conditions). In order to identify the relevant transport processes caused by ship-generated wave forcing, a field measurement campaign took place in April 2011. By measuring instantaneous water velocities, suspended sediment concentrations and wave hydrodynamics with a high temporal resolution, the effects on the sediment budget were quantified. It is found that the driving forces for these processes are the ship's speed, its blockage coefficient and the distance of the sailing ship to the timber piling. Bottom shear stresses significantly increase to values up to 10 N/m2 during a ship passage. Being much higher than the critical shear stress of 1.5 N/m2 and lasting for several minutes, the fine as well as coarser fractions of bottom sediment are dislodged and (re)suspended. Wave height also correlates well with the amount of sediment suspension. The best predictor for bank erosion is the velocity at which the displaced water mass hits the river bank. These experimental results indicate a reduced yet continuing

  3. Allegheny County-Owned Bridges Points

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset shows the location of bridges owned by Allegheny County as centroids. If viewing this description on the Western Pennsylvania Regional Data Center’s...

  4. Allegheny County-Owned Bridges Centerlines

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset shows the bridges owned by Allegheny County. If viewing this description on the Western Pennsylvania Regional Data Center’s open data portal...

  5. Influence of Icing on Bridge Cable Aerodynamics

    DEFF Research Database (Denmark)

    Koss, Holger; Frej Henningsen, Jesper; Olsen, Idar

    2013-01-01

    In recent years the relevance of ice accretion for wind-induced vibration of structural bridge cables has been recognised and became a subject of research in bridge engineering. Full-scale monitoring and observation indicate that light precipitation at moderate low temperatures between zero and -5......°C may lead to large amplitude vibrations of bridge cables under wind action. For the prediction of aerodynamic instability quasi-steady models have been developed estimating the cable response magnitude based on structural properties and aerodynamic force coefficients for drag, lift and torsion...... forces of different bridge cables types. The experiments were conducted in a wind tunnel facility capable amongst others to simulate incloud icing conditions....

  6. Assessment of the Reliability of Concrete Bridges

    DEFF Research Database (Denmark)

    Middleton, C. R.; Thoft-Christensen, Palle

    in the wake of ever increasing traffic loads and volumes, and an ageing population of bridges subject to various mechanisms of deterioration. The goal is to optimise the allocation of limited resources whilst maintaining their bridges in a safe and serviceable condition. Reliability analysis is one tool being......Although there has been a considerable amount of research into different aspects of concrete bridge reliability, it has still not been widely adopted in professional practice other than in the development and calibration of codes. This situation appears to be changing as there has been...... adopted to assist in achieving this goal. Rather than review the specific research on this subject this paper examines a number of key issues related to the practical application of reliability analysis to the assessment of concrete bridges....

  7. Pilot testing of a hydraulic bridge exciter

    Directory of Open Access Journals (Sweden)

    Andersson Andreas

    2015-01-01

    Full Text Available This paper describes the development of a hydraulic bridge exciter and its first pilot testing on a full scale railway bridge in service. The exciter is based on a hydraulic load cylinder with a capacity of 50 kN and is intended for controlled dynamic loading up to at least 50 Hz. The load is applied from underneath the bridge, enabling testing while the railway line is in service. The system is shown to produce constant load amplitude even at resonance. The exciter is used to experimentally determine frequency response functions at all sensor locations, which serve as valuable input for model updating and verification. An FE-model of the case study bridge has been developed that is in good agreement with the experimental results.

  8. Practical Approach to Fragility Analysis of Bridges

    Directory of Open Access Journals (Sweden)

    Yasamin Rafie Nazari

    2012-12-01

    Full Text Available Damages during past earthquakes reveal seismic vulnerability of bridge structures and the necessity of probabilistic approach toward seismic performance evaluation of bridges and its interpretation in terms of decision variables such as repair cost, downtime and life loss. This Procedure involves hazard analysis, structural analysis, damage analysis and loss analysis. The purpose of present study is reviewing different methods developed to derive fragility curves for damage analysis of bridges and demonstrating a simple procedure for fragility analysis using Microsoft Office Excel worksheet to reach probability of occurring predefined level of damage due to different levels of seismic demand parameters. The input of this procedure is the intensity of ground motion and the output is an appropriate estimate of the expected damage. Different observed damages of the bridges are discussed and compared the practical definition of damage states. Different methods of fragility analyses are discussed and a practical step by step example is illustrated.

  9. Identifying hidden sexual bridging communities in Chicago.

    Science.gov (United States)

    Youm, Yoosik; Mackesy-Amiti, Mary Ellen; Williams, Chyvette T; Ouellet, Lawrence J

    2009-07-01

    Bridge populations can play a central role in the spread of human immunodeficiency virus (HIV) by providing transmission links between higher and lower prevalence populations. While social network methods are well suited to the study of bridge populations, analyses tend to focus on dyads (i.e., risk between drug and/or sex partners) and ignore bridges between distinct subpopulations. This study takes initial steps toward moving the analysis of sexual network linkages beyond individual and risk group levels to a community level in which Chicago's 77 community areas are examined as subpopulations for the purpose of identifying potential bridging communities. Of particular interest are "hidden" bridging communities; that is, areas with above-average levels of sexual ties with other areas but whose below-average AIDS prevalence may hide their potential importance for HIV prevention. Data for this analysis came from the first wave of recruiting at the Chicago Sexual Acquisition and Transmission of HIV Cooperative Agreement Program site. Between August 2005 through October 2006, respondent-driven sampling was used to recruit users of heroin, cocaine, or methamphetamine, men who have sex with men regardless of drug use, the sex partners of these two groups, and sex partners of the sex partners. In this cross-sectional study of the sexual transmission of HIV, participants completed a network-focused computer-assisted self-administered interview, which included questions about the geographic locations of sexual contacts with up to six recent partners. Bridging scores for each area were determined using a matrix representing Chicago's 77 community areas and were assessed using two measures: non-redundant ties and flow betweenness. Bridging measures and acquired immunodeficiency syndrome (AIDS) case prevalence rates were plotted for each community area on charts representing four conditions: below-average bridging and AIDS prevalence, below-average bridging and above

  10. Inspection Based Evaluation of a Danish Road Bridge

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper it is shown how an inspection-based evaluation of a Danish road bridge may be performed using the BRIDGE1 and BRIDGE2 bridge management systems produced within the EC-supported research programme "Assessment of Performance and Optimal Strategies for Inspection and Maintenance...

  11. TMACS test procedure TP012: Panalarm software bridge

    International Nuclear Information System (INIS)

    This Test Procedure addresses the testing of the functionality of the Tank Monitor and Control System (TMACS) Panalarm bridge software. The features to be tested are: Bridge Initialization Options; Bridge Communication; Bridge Performance; Testing Checksum Errors; and Testing Command Reject Errors. Only the first three could be tested; the last two have been deferred to a later date

  12. Assessment of a Bridge WIM System on Integral Concrete Bridges and on Steel Orthotropic Decks

    OpenAIRE

    Ieng, Sio Song; SCHMIDT, Franziska; ROMBONI, Frédéric; Jacob, Bernard

    2011-01-01

    Bridge-Weigh-In-Motion uses bridges as a scale to weigh vehicles. Practically, this is done by measuring the strains in that bridge, and relating them to the weight and dimensions of a truck called “calibration trucks” whose shape and axle weights are well known. This article summarizes different B-WIM experiments the institute IFSTTAR (formerly called LCPC) realized and the lessons drawn from this experience. First, the system has been tested on frame-type bridges with integral s...

  13. Experimental study of single span railway bridges

    OpenAIRE

    Rigueiro, Constança; Rebelo, C.; Silva, L. Simões da

    2007-01-01

    The main purpose of this paper is to present some results concerning the investigation that has been done by the authors regarding the dynamic response of small to médium span railway bridges using response acceleration data colleted during the measurements carried out on single span bridges on the railway track Linz-Wels, in Austria. Using output-only methods in this experimental program, it was possible to have an estimation of the igenfrequencies, mode shapes and the corresponding viscous ...

  14. Active control of vibrations in pedestrian bridges

    OpenAIRE

    Álvaro Cunha; Carlos Moutinho

    1999-01-01

    This paper, apart from making a brief general reference to vibration problems in pedestrian bridges, as well as to the form of modelling of dynamic pedestrian loads, presents the use of a predictive control strategy for the numerical simulation of the dynamic response of actively controlled structures of this type. The consideration of this control strategy permitted the development of a computational model, which was applied to the study of a pedestrian cable-stayed bridge, in order to show ...

  15. Building Organic Bridges: Volume 1, Argentina - France

    OpenAIRE

    Rahmann, Gerold; Aksoy, Uygun

    2014-01-01

    [Foreword ...] The 18th IFOAM Organic World Congress held on 13-15 October, 2014 in Istanbul-Turkey targets to 'build organic bridges'. The Scientific track will contribute to bridging not only scientists but also institutions and disciplines, and to linking more developed and less developed, rural and urban, research to extension, plant to animal, farm practices to world-wide problems and producer and consumers. Organic is a management system that requires a diversity of inputs from differen...

  16. Building Organic Bridges: Volume 2, Germany - India

    OpenAIRE

    Rahmann, Gerold; Aksoy, Uygun

    2014-01-01

    [Foreword ...] The 18th IFOAM Organic World Congress held on 13-15 October, 2014 in Istanbul-Turkey targets to 'build organic bridges'. The Scientific track will contribute to bridging not only scientists but also institutions and disciplines, and to linking more developed and less developed, rural and urban, research to extension, plant to animal, farm practices to world-wide problems and producer and consumers. Organic is a management system that requires a diversity of inputs from differen...

  17. Thermal Bridge Effects in Walls Separating Rowhouses

    DEFF Research Database (Denmark)

    Rose, Jørgen

    1997-01-01

    In this report the thermal bridge effects at internal wall/roof junctions in rowhouses are evaluated. The analysis is performed using a numerical calculation programme, and different solutions are evaluated with respect to extra heat loss and internal surface temperatures.......In this report the thermal bridge effects at internal wall/roof junctions in rowhouses are evaluated. The analysis is performed using a numerical calculation programme, and different solutions are evaluated with respect to extra heat loss and internal surface temperatures....

  18. External Prestressing Bridge Reinforcement Technology Review

    Directory of Open Access Journals (Sweden)

    Zhu Hanbing

    2015-01-01

    Full Text Available Externally prestressed bridge can not only limit and reduce the cracks and deformation of the structure, improve the rigidity and bearing capacity of structure, improve the stress state of structure, but also have less interference for bridge operation when it is operating and have the good economic efficiency. This paper introduces the advantages and disadvantages of external prestressed strengthening technique, its calculation theory and construction technology described in detail, and finally the paper discusses the deficiency of existing research.

  19. Subscapularis Tendon Repair Using Suture Bridge Technique

    OpenAIRE

    Park, Yong Bok; Park, Young Eun; Koh, Kyoung Hwan; Lim, Tae Kang; Shon, Min Soo; Yoo, Jae Chul

    2015-01-01

    The subscapularis tendon plays an essential role in shoulder function. Although subscapularis tendon tears are less common than other rotator cuff tears, tears of the subscapularis tendon have increasingly been recognized with the advent of magnetic resonance imaging and arthroscopy. A suture bridge technique for the treatment of posterosuperior rotator cuff tears has provided the opportunity to improve the pressurized contact area and mean footprint pressure. However, suture bridge fixation ...

  20. Framework for Bridges Maintenance in Egypt

    Directory of Open Access Journals (Sweden)

    Hesham Abd Elkhalek

    2016-01-01

    Full Text Available The traditional approaches for bridges maintenance is proven to be inefficient as they lead to random way of spending maintenance budget and deteriorating bridge conditions. In many cases, maintenance activities are performed due to user complaints. The objective of this paper is to develop a practical and reliable framework to manage the maintenance and repair activities of Bridges network in Egypt considering performance and budget limits. The model solves an optimization problem that maximizes the average condition of the network given the limited budget using Genetic Algorithm (GA. The main tasks of the system are bridge inventory, condition assessment, deterioration using markov model, and maintenance optimization. The developed model takes into account multiple parameters including serviceability requirements, budget allocation, element importance on structural safety and serviceability, bridge impact on network, and traffic. A questionnaire is conducted to complete the research scope. The proposed model is implemented in software, which provides a friendly user interface. The results of the framework are multi – year maintenance plan for the entire network for up to five years. A case study is presented for validating and testing the model with Data collected from “General Authority for Roads, Bridges and Land Transport” in Egypt.

  1. Precast Pearl-Chain concrete arch bridges

    DEFF Research Database (Denmark)

    Halding, Philip Skov; Hertz, Kristian Dahl; Schmidt, Jacob Wittrup

    2015-01-01

    A Pearl-Chain Bridge is a closed-spandrel arch bridge consisting of a number of straight pre-fabricated so called Super-Light Deck elements put together in an arch shape by post-tensioning cables. Several Pearl-Chain arches can be positioned adjacent to each other by a crane to achieve a bridge...... the technology was used. We also study other important components and details in the Pearl-Chain Bridge concept and review the effects of different types of loads. A theoretical case study of a circular 30 m span Pearl-Chain Bridge is presented showing the influence of a number of parameters: The number of post......-tensioning cables, the rise to span ratio, the height of the filling, and the height of the Super-Light Decks. We find that Pearl-Chain Bridges can be adjusted to resist specific moment loads by changing the normal force in the arch cross section by altering the above parameters. It is also found that the negative...

  2. In situ biomonitoring of juvenile Chinook salmon (Onchorhynchus tshawytscha) using biomarkers of chemical exposures and effects in a partially remediated urbanized waterway of the Puget Sound, WA

    Energy Technology Data Exchange (ETDEWEB)

    Browne, Eva [Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way Northeast, Suite 100, Seattle, WA 98105-6099 (United States); Kelley, Matthew; Zhou, Guo-Dong; He, Ling Yu; McDonald, Thomas; Wang, Shirley [Department of Environmental and Occupational Health, Texas A and M Health Science Center, College Station, TX 77843-1266 (United States); Duncan, Bruce [US Environmental Protection Agency, Region 10, 1200 Sixth Avenue, Seattle, WA 98101 (United States); Meador, James [Ecotoxicology Division, National Marine Fisheries Service, Seattle, WA 98105 (United States); Donnelly, Kirby [Department of Environmental and Occupational Health, Texas A and M Health Science Center, College Station, TX 77843-1266 (United States); Gallagher, Evan, E-mail: evang3@u.washington.edu [Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way Northeast, Suite 100, Seattle, WA 98105-6099 (United States)

    2010-10-15

    In situ biomonitoring has been used to assess the effects of pollution on aquatic species in heavily polluted waterways. In the current study, we used in situ biomonitoring in conjunction with molecular biomarker analysis to determine the effects of pollutant exposure in salmon caged in the Duwamish waterway, a Pacific Northwest Superfund site that has been subject to remediation. The Duwamish waterway is an important migratory route for Pacific salmon and has received historic inputs of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). Juvenile pre-smolt Chinook salmon (Oncorhynchus tshawytscha) caged for 8 days in the three contaminated sites in close proximity within the Duwamish were analyzed for steady state hepatic mRNA expression of 7 exposure biomarker genes encompassing several gene families and known to be responsive to pollutants, including cytochrome P4501A (CYP1A) and CYP2K1, glutathione S-transferase {pi} class (GST-{pi}), microsomal GST (mGST), glutamylcysteine ligase catalytic subunit (GCLC), UDP-glucuronyltransferase family 1 (UDPGT), and type 2 deiodinase (type 2 DI, or D2). Quantitation of gene expression was accomplished by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) in assays developed specifically for Chinook salmon genes. Gill PAH-DNA adducts were assessed as a chemical effects biomarker using {sup 32}P-postlabeling. The biomarkers in the field-caged fish were analyzed with respect to caged animals maintained at the hatchery receiving flow-through water. Chemical analysis of sediment samples from three field sampling sites revealed relatively high concentrations of total PAHs in one site (site B2, 6711 ng/g dry weight) and somewhat lower concentrations of PAHs in two adjacent sites (sites B3 and B4, 1482 and 1987 ng/g, respectively). In contrast, waterborne PAHs at all of the sampling sites were relatively low (<1 ng/L). Sediment PCBs at the sites ranged from a low of 421 ng/g at site B3

  3. Marine habitat mapping of the Milford Haven Waterway, Wales, UK: Comparison of facies mapping and EUNIS classification for monitoring sediment habitats in an industrialized estuary

    Science.gov (United States)

    Carey, Drew A.; Hayn, Melanie; Germano, Joseph D.; Little, David I.; Bullimore, Blaise

    2015-06-01

    A detailed map and dataset of sedimentary habitats of the Milford Haven Waterway (MHW) was compiled for the Milford Haven Waterway Environmental Surveillance Group (MHWESG) from seafloor images collected in May, 2012 using sediment-profile and plan-view imaging (SPI/PV) survey techniques. This is the most comprehensive synoptic assessment of sediment distribution and benthic habitat composition available for the MHW, with 559 stations covering over 40 km2 of subtidal habitats. In the context of the MHW, an interpretative framework was developed that classified each station within a 'facies' that included information on the location within the waterway and inferred sedimentary and biological processes. The facies approach provides critical information on landscape-scale habitats including relative location and inferred sediment transport processes and can be used to direct future monitoring activities within the MHW and to predict areas of greatest potential risk from contaminant transport. Intertidal sediment 'facies' maps have been compiled in the past for MHW; this approach was expanded to map the subtidal portions of the waterway. Because sediment facies can be projected over larger areas than individual samples (due to assumptions based on physiography, or landforms) they represent an observational model of the distribution of sediments in an estuary. This model can be tested over time and space through comparison with additional past or future sample results. This approach provides a means to evaluate stability or change in the physical and biological conditions of the estuarine system. Initial comparison with past results for intertidal facies mapping and grain size analysis from grab samples showed remarkable stability over time for the MHW. The results of the SPI/PV mapping effort were cross-walked to the European Nature Information System (EUNIS) classification to provide a comparison of locally derived habitat mapping with European-standard habitat

  4. Response Modification Factors for Concrete Bridges in Europe

    OpenAIRE

    Kappos, A. J.; Paraskeva, T. S.; Moschonas, I. F.

    2013-01-01

    The paper presents a methodology for evaluating the actual response modification factors (q or R) of bridges and applies it to seven concrete bridges typical of the stock found in southern Europe. The usual procedure for analytically estimating the q-factor is through pushover curves derived for the bridge in (at least) its longitudinal and transverse directions. The shape of such curves depends on the seismic energy dissipation mechanism of the bridge; hence, bridges are assigned to two cate...

  5. Role of multiprotein bridging factor 1 in archaea: bridging the domains?

    NARCIS (Netherlands)

    Koning, de B.; Blombach, F.; Wu Hao,; Brouns, S.J.J.; Oost, van der J.

    2009-01-01

    MBF1 (multiprotein bridging factor 1) is a highly conserved protein in archaea and eukaryotes. It was originally identified as a mediator of the eukaryotic transcription regulator BmFTZ-F1 (Bombyx mori regulator of fushi tarazu). MBF1 was demonstrated to enhance transcription by forming a bridge bet

  6. Micromechanical model of cross-over fibre bridging - Prediction of mixed mode bridging laws

    DEFF Research Database (Denmark)

    Sørensen, Bent F.; Gamstedt, E.K.; Østergaard, Rasmus Christian;

    2008-01-01

    The fracture resistance of fibre composites can be greatly enhanced by crack bridging. In situ observations of mixed mode crack growth in a unidirectional carbon-fibre/epoxy composite reveal crack bridging by single fibres and by beam-like ligaments consisting of several fibres. Based on the obse...

  7. Comprehensive Real-Time Bridge Health Monitoring System of Tongtai Bridge

    Directory of Open Access Journals (Sweden)

    Lei Su-su

    2015-01-01

    Full Text Available Tongtai Bridge is the world’s largest suspension curve-girder-skew-arch bridge, which is located in Zhangjiakou, China. The understanding of mechanics characteristics is limited to such complex bridges, so it is necessary to establish reliable health monitoring system to investigate the static and dynamic responses and monitor the safety of the bridge. A comprehensive real-time bridge health monitoring system is establish, which includes four aspects: sensor system, data acquisition and transmission system, data processing and control system, structure early warning and security assessment system. The paper systematically describes the system design principles, sensor layout, and monitoring content, then expounds system integration and function of each subsystem.

  8. A probabilistic bridge safety evaluation against floods.

    Science.gov (United States)

    Liao, Kuo-Wei; Muto, Yasunori; Chen, Wei-Lun; Wu, Bang-Ho

    2016-01-01

    To further capture the influences of uncertain factors on river bridge safety evaluation, a probabilistic approach is adopted. Because this is a systematic and nonlinear problem, MPP-based reliability analyses are not suitable. A sampling approach such as a Monte Carlo simulation (MCS) or importance sampling is often adopted. To enhance the efficiency of the sampling approach, this study utilizes Bayesian least squares support vector machines to construct a response surface followed by an MCS, providing a more precise safety index. Although there are several factors impacting the flood-resistant reliability of a bridge, previous experiences and studies show that the reliability of the bridge itself plays a key role. Thus, the goal of this study is to analyze the system reliability of a selected bridge that includes five limit states. The random variables considered here include the water surface elevation, water velocity, local scour depth, soil property and wind load. Because the first three variables are deeply affected by river hydraulics, a probabilistic HEC-RAS-based simulation is performed to capture the uncertainties in those random variables. The accuracy and variation of our solutions are confirmed by a direct MCS to ensure the applicability of the proposed approach. The results of a numerical example indicate that the proposed approach can efficiently provide an accurate bridge safety evaluation and maintain satisfactory variation. PMID:27386269

  9. Natural vibration dynamics of Rainbow Bridge, Utah

    Science.gov (United States)

    Moore, J. R.; Thorne, M. S.; Wood, J. R.; Doyle, S.; Stanfield, E.; White, B.

    2015-12-01

    We measured resonant frequencies of Rainbow Bridge, Utah, one of the world's longest rock spans, during a field experiment recording ambient vibration data. Measurements were generated over 20 hours on March 23-24, 2015 using two broadband three-component seismometers placed on the bridge, and compared to concurrent data from nearby reference stations 20 and 220 m distant. We identified seven distinct modes of vibration for Rainbow Bridge between 1 and 6 Hz. Data for each resonant frequency was then analyzed to determine the frequency-dependent polarization vector in an attempt to clarify mode shapes; e.g. the fundamental mode represents out-of-plane horizontal flexure. We compared experimental data to results of 3D numerical modal analysis, using a new photogrammetric model of Rainbow Bridge generated in this study imported into COMSOL Multiphysics. Results compare well with measured data for seven of the first eight modeled modes, matching vibrational frequencies and polarization orientations generally within 10%. Only predicted mode 6 was not explicitly apparent in our experimental data. Large site-to-reference spectral ratios resolved from experimental data indicate high amplification on the bridge as compared to nearby bedrock.

  10. Bridges in the random-cluster model

    Directory of Open Access Journals (Sweden)

    Eren Metin Elçi

    2016-02-01

    Full Text Available The random-cluster model, a correlated bond percolation model, unifies a range of important models of statistical mechanics in one description, including independent bond percolation, the Potts model and uniform spanning trees. By introducing a classification of edges based on their relevance to the connectivity we study the stability of clusters in this model. We prove several exact relations for general graphs that allow us to derive unambiguously the finite-size scaling behavior of the density of bridges and non-bridges. For percolation, we are also able to characterize the point for which clusters become maximally fragile and show that it is connected to the concept of the bridge load. Combining our exact treatment with further results from conformal field theory, we uncover a surprising behavior of the (normalized variance of the number of (non-bridges, showing that it diverges in two dimensions below the value 4cos2⁡(π/3=0.2315891⋯ of the cluster coupling q. Finally, we show that a partial or complete pruning of bridges from clusters enables estimates of the backbone fractal dimension that are much less encumbered by finite-size corrections than more conventional approaches.

  11. Fast Hough transform for automatic bridge extraction

    Science.gov (United States)

    Hao, Qiwei; Chen, Xiaomei; Ni, Guoqiang; Zhang, Huaili

    2008-03-01

    In this paper, a new method to recognize bridge in the complicated background is presented. The algorithm takes full advantages of the characteristics of the bridge image. Firstly, the image is preprocessed and the object edges are extracted. Then according to the limitations of traditional Hough transform (HT), the extraction method of the image line segment characteristic of HT is improved, which eliminates spurious peaks on the basis of global and local thresholds, discriminates the position relation between two straight line segments, and merges segments with near endpoints, etc. Experiments show that this algorithm is more precise and efficient than traditional HT, moreover it can provide a complete description of the bridge in a complicated background.

  12. MINERAL BRIDGES OF NACRE AND ITS EFFECTS

    Institute of Scientific and Technical Information of China (English)

    宋凡; 白以龙

    2001-01-01

    Nacre, or mother-of-pearl, is a kind of composites of aragonite platelets sandwiched between organic materials. Its excellent mechanical properties are thought to stem from the microarchitecture that is traditionally described as a "brick and mortar" arrangement. In this paper, a new microstructure, referred to as mineral bridge in the biomineralization, is directly observed in the organic matrix layers (mortar) of nacre. This is an indication that the organic matrix layer of nacre should be treated as a three-dimensional interface and the microarchitecture of nacre ought to be considered as a "brick-bridge-mortar" structure rather than the traditional one. Experiments and analyses show that the mineral bridges not only improve the mechanical properties of the organic matrix layers but also play an important role in the pattern of the crack extension in nacre.

  13. MULTIPHASE BLASTING OF THE BRIDGE ACROSS THE DRENICA RIVER

    OpenAIRE

    Branko Božić

    1989-01-01

    The construction of new bridges on the sites of the existing ones require demolition of the old bridge. Due to closeness of newly erected bridge elements the fundations of old bridges are demolished by multiphase blasting process. The blasting of the piers and anchorages of the bridge across 'the Drenica river carrying the Balačevac—Goleš industrial railway was done in four phases. The piers and anchorages of a new bridge and its construction elements have been erected before (the paper is pu...

  14. Bridging radiation policy and science

    International Nuclear Information System (INIS)

    Scientists, regulators, and policy makers from five continents and 20 countries reached consensus on a number of conclusions and recommendations regarding low-level ionizing radiation exposures at an international conference, 'Bridging Radiation Policy and Science,' at the Airlie Center in Warrenton, Virginia, 1-5 December 1999. The goal of the conference was to develop strategies for formulating national and international policy based on current scientific information in the context of economic, political, and social concerns. Specifically, attendees explored how to establish public policies with respect to radiation protection in view of the scientific uncertainties of the effects of low-level radiation [<100 millisievert (mSv)]. Conference participants agreed that science will not likely answer in the near future fundamental questions about the shape of the dose-response curve and mechanisms of effects of radiation at low doses. The conference endorsed the quest for a prudent and coherent radiation policy based on the International Atomic Energy Agency's (IAEA) 'evolving global framework'. The Conference participants agreed upon the following recommendations: Policy discussions on the regulation of radiation sources delivering low-level radiation should include references to natural background radiation. The conference supports the evolving global framework of the International Atomic Energy Agency (IAEA) for the safe use of radiation. The conference supports further development and evaluation of the ideas associated with the proposal on controllable dose. No radiation dose is below regulatory concern but certain levels should be below regulatory action, and appropriate dose levels should be established. Fundamental questions about the shape of the dose-response curve and mechanisms of effects of radiation at low doses are unlikely to be answered in the near future. Scientific research, including molecular and cellular radiobiology studies are critical in order

  15. Extracorporeal Life Support Bridge to Ventricular Assist Device: The Double Bridge Strategy.

    Science.gov (United States)

    Marasco, Silvana F; Lo, Casey; Murphy, Deirdre; Summerhayes, Robyn; Quayle, Margaret; Zimmet, Adam; Bailey, Michael

    2016-01-01

    In patients requiring left ventricular assist device (LVAD) support, it can be difficult to ascertain suitability for long-term mechanical support with LVAD and eventual transplantation. LVAD implantation in a shocked patient is associated with increased morbidity and mortality. Interest is growing in the utilization of extracorporeal life support (ECLS) as a bridge-to-bridge support for these critically unwell patients. Here, we reviewed our experience with ECLS double bridging. We hypothesized that ECLS double bridging would stabilize end-organ dysfunction and reduce ventricular assist device (VAD) implant perioperative mortality. We conducted a retrospective review of prospectively collected data for 58 consecutive patients implanted with a continuous-flow LVAD between January 2010 and December 2013 at The Alfred Hospital, Melbourne, Victoria, Australia. Twenty-three patients required ECLS support pre-LVAD while 35 patients underwent LVAD implantation without an ECLS bridge. Preoperative morbidity in the ECLS bridge group was reflected by increased postoperative intensive care duration, blood loss, blood product use, and postoperative renal failure, but without negative impact upon survival when compared with the no ECLS group. ECLS stabilization improved end-organ function pre-VAD implant with significant improvements in hepatic and renal dysfunction. This series demonstrates that the use of ECLS bridge to VAD stabilizes end-organ dysfunction and reduces VAD implant perioperative mortality from that traditionally reported in these "crash and burn" patients.

  16. The seismic response of concrete arch bridges (with focus on the Bixby Creek bridge Carmel, California)

    Energy Technology Data Exchange (ETDEWEB)

    Hoehler, M; McCallen, D; Noble, C

    1999-06-01

    The analysis, and subsequent retrofit, of concrete arch bridges during recent years has relied heavily on the use of computational simulation. For seismic analysis in particular, computer simulation, typically utilizing linear approximations of structural behavior, has become standard practice. This report presents the results of a comprehensive study of the significance of model sophistication (i.e. linear vs. nonlinear) and pertinent modeling assumptions on the dynamic response of concrete arch bridges. The study uses the Bixby Creek Bridge, located in California, as a case study. In addition to presenting general recommendations for analysis of this class of structures, this report provides an independent evaluation of the proposed seismic retrofit for the Bixby Creek Bridge. Results from the study clearly illustrate a reduction of displacement drifts and redistribution of member forces brought on by the inclusion of material nonlinearity. The analyses demonstrate that accurate modeling of expansion joints, for the Bixby Creek Bridge in particular, is critical to achieve representative modal and transient behavior. The inclusion of near-field displacement pulses in ground motion records was shown to significantly increase demand on the relatively softer, longer period Bixby Creek Bridge arch. Stiffer, shorter period arches, however, are more likely susceptible to variable support motions arising from the canyon topography typical for this class of bridges.

  17. V. Tormis: "Bridge of Song / Brian Hunt

    Index Scriptorium Estoniae

    Hunt, Brian

    1997-01-01

    Uuest heliplaadist "V. Tormis: "Bridge of Song" - Bridge of Song; Singing aboard ship; Brides Farewell; Kihnu Island Wedding Songs; 17 Estonian Wedding Songs; Three Estonian Game Songs; Four Estonian Lullabies. Estonian Radio Choir / Toomas Kapten. Finlandia 4509 96937-2; 56:52 DDD; "People of Kalevala" - God protect us from war; Vespian Winter; Eagle Flew From the North East; Plague Memory; Vainamoinen's Words of Wisdom; The Seventeenth Rune of Kalevala. National Male Choir of Estonia. Finlandia 0630 12245-2; 56:52 DDD

  18. Stability of a liquid bridge under vibration

    Science.gov (United States)

    Benilov, E. S.

    2016-06-01

    We examine the stability of a vertical liquid bridge between two vertically vibrating, coaxial disks. Assuming that the vibration amplitude and period are much smaller than the mean distance between the disks and the global timescale, respectively, we employ the method of multiple scales to derive a set of asymptotic equations. The set is then used to examine the stability of a bridge of an almost cylindrical shape. It is shown that, if acting alone, gravity is a destabilizing influence, whereas vibration can weaken it or even eliminate altogether. Thus, counter-intuitively, vibration can stabilize an otherwise unstable capillary structure.

  19. ParB spreading requires DNA bridging

    OpenAIRE

    Graham, Thomas G. W.; Wang, Xindan; Song, Dan; Etson, Candice M.; van Oijen, Antoine M.; Rudner, David Z.; Loparo, Joseph J.

    2014-01-01

    The bacterial parABS system is employed for plasmid partitioning and chromosome segregation. ParB binds to parS sites and associates with broad regions of adjacent DNA, a phenomenon known as spreading. However, the molecular basis for spreading is unknown. Using single-molecule approaches, Graham et al. demonstrate DNA bridging by B. subtilis ParB (Spo0J). Spo0J mutations that disrupt DNA bridging lead to defective spreading and SMC condensin complex recruitment. This study suggests a novel, ...

  20. Germanium-overcoated niobium Dayem bridges

    Science.gov (United States)

    Holdeman, L. B.; Peters, P. N.

    1976-01-01

    Overcoating constriction microbridges with semiconducting germanium provides additional thermal conductivity at liquid-helium temperatures to reduce the effects of self-heating in these Josephson junctions. Microwave-induced steps were observed in the I-V characteristics of an overcoated Dayem bridge fabricated in a 15-nm-thick niobium film; at least 20 steps could be counted at 4.2 K. No steps were observed in the I-V characteristics of the bridge prior to overcoating. In addition, the germanium overcoat can protect against electrical disturbances at room temperature.

  1. Ambient Vibration Test on Reinforced Concrete Bridges

    Directory of Open Access Journals (Sweden)

    Idris Nurul Shazwin

    2016-01-01

    Full Text Available An investigation was carried out to determine dynamic characteristic of reinforced concrete (RC bridges by using ambient vibration test (AVT. The ambient vibration sources on bridges may come from traffic, wind, wave motion and seismic events. AVT describes the dynamic characteristics of the bridge and ground by measuring the natural frequencies using highly sensitive seismometer sensor. This test is beneficial due to light weight equipment and smaller number of operator required, cheap and easy to be handled. It is able to give a true picture of the bridge dynamic behavior without any artificial force excitation when vibration data is recorded. A three-span reinforced concrete bridge located in Sri Medan, Batu Pahat, Johor was measured by using microtremor equipment consist of three units of 1 Hz eigenfrequency passive sensors used in this test was performed in normal operating condition without excitation required from any active sources or short period noise perturbations. Ten measurements were conducted on the bridge deck and ten measurements on the ground surface in order to identify the natural frequencies of the bridge. Several peak frequencies were identified from three components of Fourier Amplitude Spectra (FAS in transverse (North-South, longitudinal (East-West and vertical (Up-Down direction as well as squared average Horizontal to Vertical Spectral Ratio (HVSR of ground response, computed by using Geopsy software. From the result, it was expected the bridge have five vibration modes frequencies in the range of 1.0 Hz and 7.0 Hz with the first two modes in the transverse and longitudinal direction having a frequency 1.0 Hz, the third mode is 2.2 Hz in transverse direction, fourth and fifth mode is 5.8 Hz and 7.0 Hz. For ground natural frequencies are in range 1.0 Hz to 1.3 Hz for North-South direction and 1.0 Hz to 1.6 Hz for East-West direction. Finally the results are compared with several empirical formulas for simple

  2. A Bridge Deflection Monitoring with GPS

    Science.gov (United States)

    Figurski, M.; Gałuszkiewicz, M.; Wrona, M.

    2007-01-01

    This paper introduces results of investigation carried on by The Applied Geomatics Section in Military University of Technology. Research includes possibilities of monitoring dynamic behavior of a bridge using high rate GPS data. Whole event was executed with collaboration of The Road and Bridge Management and The Warsaw Geodesy Company. Interdisciplinary approach with this project allows authors to get reliable information about investigating constructions and their respond for true traffic loading detected by GPS receivers. Way of compute data and used software (TRACK) are also shown in this paper.

  3. Planar Hall effect bridge magnetic field sensors

    DEFF Research Database (Denmark)

    Henriksen, A.D.; Dalslet, Bjarke Thomas; Skieller, D.H.;

    2010-01-01

    Until now, the planar Hall effect has been studied in samples with cross-shaped Hall geometry. We demonstrate theoretically and experimentally that the planar Hall effect can be observed for an exchange-biased ferromagnetic material in a Wheatstone bridge topology and that the sensor signal can...... be significantly enhanced by a geometric factor. For the samples in the present study, we demonstrate an enhancement of the sensor output by a factor of about 100 compared to cross-shaped sensors. The presented construction opens a new design and application area of the planar Hall effect, which we term planar...... Hall effect bridge sensors....

  4. Planar Hall effect bridge magnetic field sensors

    Science.gov (United States)

    Henriksen, A. D.; Dalslet, B. T.; Skieller, D. H.; Lee, K. H.; Okkels, F.; Hansen, M. F.

    2010-07-01

    Until now, the planar Hall effect has been studied in samples with cross-shaped Hall geometry. We demonstrate theoretically and experimentally that the planar Hall effect can be observed for an exchange-biased ferromagnetic material in a Wheatstone bridge topology and that the sensor signal can be significantly enhanced by a geometric factor. For the samples in the present study, we demonstrate an enhancement of the sensor output by a factor of about 100 compared to cross-shaped sensors. The presented construction opens a new design and application area of the planar Hall effect, which we term planar Hall effect bridge sensors.

  5. “On a bridge in Berlin”

    DEFF Research Database (Denmark)

    Pihl, Ole Verner

    2013-01-01

    that jumps in time and place: it begins with Martin Heidegger´s quotation “The Bridge gathers to itself in its own way earth and sky, divinities and mortals”, and the bridge is a state of mind, a chronotope, a portal in time between past, present, and future. The methodological approach is based...... on Bachelard and Heidegger. This GN investigates how architecture changes our cities and cultural identity. It merges different narrative time layers as: childhood memories, dreams, hallucinations, fiction, past, present, and future. The findings of this paper explains why a cross disciplinary approach...

  6. Composite timber-concrete road bridge structure

    Directory of Open Access Journals (Sweden)

    Stojić Dragoslav

    2007-01-01

    Full Text Available This work presents preliminary design of the road bridge made of laminated timber. The supporting system of the main bearing elements is made of the laminated timber in the system of arch with three joints; the bridge slab is designed as continuous slab, made of nine equal fields; each pair is made as composite timber-concrete beam, where the road slab is made of concrete and the needle pieces are made of timber. Fundament is based on HW piles. All the elements are designed to Eurocode.

  7. Diode-quad bridge for reactive transducers and FM discriminators

    Science.gov (United States)

    Harrison, D. R.; Dimeff, J.

    1972-01-01

    Diode-quad bridge circuit was developed for use with pressure-sensitive capacitive transducers, liquid-level measuring devices, proximity deflection sensors, and inductive displacement sensors. It may also be used as FM discriminator and as universal impedance bridge.

  8. Foot force models of crowd dynamics on a wobbly bridge

    CERN Document Server

    Belykh, Igor; Belykh, Vladamir

    2016-01-01

    Modern pedestrian and suspension bridges are designed using industry-standard packages, yet disastrous resonant vibrations are observed, necessitating multi-million dollar repairs. Recent examples include pedestrian induced vibrations during the openings of the Solf\\'erino Bridge in Paris in 1999 and the increased bouncing of the Squibb Park Bridge in Brooklyn in 2014. The most prominent example of an unstable lively bridge is the London Millennium Bridge which started wobbling as a result of pedestrian-bridge interactions. Pedestrian phase-locking due to footstep phase adjustment, is suspected to be the main cause of its large lateral vibrations; however, its role in the initiation of wobbling was debated. In this paper, we develop foot force models of pedestrians' response to bridge motion and detailed, yet analytically tractable models of crowd phase-locking. We use bio-mechanically inspired models of crowd lateral movement to investigate to what degree pedestrian synchrony must be present for a bridge to ...

  9. Violin bridge mobility analysis under in-plane excitation.

    Science.gov (United States)

    Zhang, Cheng-Zhong; Zhang, Guang-Ming; Ye, Bang-Yan; Liang, Li-Dong

    2013-11-08

    The vibration of a violin bridge is a dynamic contact vibration with two interfaces: strings-bridge, and bridge feet-top plate. In this paper, the mobility of an isolated bridge under in-plane excitation is explored using finite element modeling based on the contact vibration model. Numerical results show that the dynamic contact stiffness in the two contact interfaces has a great impact on the bridge mobility. A main resonance peak is observed in the frequency range of 2-3 kHz in the frequency response of the isolated bridge when the contact stiffness is smaller than a critical threshold. The main resonance peak frequency is affected by the contact stiffness as well. In order to verify the numerical findings, a novel experimental system is then designed on the basis of a piezoelectric dynamometer for bridge mobility analysis. Experimental results confirm the impact of the dynamic contact stiffness on the bridge mobility.

  10. CDC WONDER: Population - Bridged-Race July 1st Estimates

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Population - Bridged-Race July 1st Estimates online databases report bridged-race population estimates of the July 1st resident population of the United States,...

  11. Violin Bridge Mobility Analysis under In-Plane Excitation

    Directory of Open Access Journals (Sweden)

    Cheng-Zhong Zhang

    2013-11-01

    Full Text Available The vibration of a violin bridge is a dynamic contact vibration with two interfaces: strings-bridge, and bridge feet-top plate. In this paper, the mobility of an isolated bridge under in-plane excitation is explored using finite element modeling based on the contact vibration model. Numerical results show that the dynamic contact stiffness in the two contact interfaces has a great impact on the bridge mobility. A main resonance peak is observed in the frequency range of 2–3 kHz in the frequency response of the isolated bridge when the contact stiffness is smaller than a critical threshold. The main resonance peak frequency is affected by the contact stiffness as well. In order to verify the numerical findings, a novel experimental system is then designed on the basis of a piezoelectric dynamometer for bridge mobility analysis. Experimental results confirm the impact of the dynamic contact stiffness on the bridge mobility.

  12. Hydraulic bridges in unsaturated coarse granular media: Influence of bridge size and conductivity on flow through clasts

    Science.gov (United States)

    Jayakody, Jeevan A.; Nicholl, Michael J.

    2016-10-01

    Unsaturated flow in coarse granular media must pass through hydraulic bridges (e.g., pendular water, porous connections) that form a physical connection between adjoining clasts. Previous studies suggest that volumetric flow through a porous clast (Q) will be linearly dependent on the cross-sectional area of the hydraulic bridges, and understate the importance of bridge conductivity. Numerical simulations were performed to explore steady-state flow through a spherical clast with identical bridges located at the top and bottom. The cross-sectional area of the bridges relative to that of the clast (Ar) was varied across six orders of magnitude. The ratio of hydraulic conductivity between bridges and clasts (Kb/Kc) was varied across 12 orders of magnitude to consider resistive, neutral, and conductive bridges. Results show that hydraulic bridges place a primary control on both Q and flux distribution within the clast. For neutral and conductive bridges (Kb/Kc ≥1), Ar is the dominant factor in determining Q, while Kb/Kc is the primary control for resistive bridges (Kb/Kc < 1). For all bridges, Q shows a non-linear dependency on both Ar and Kb/Kc. The intra-clast flow distribution shifts outwards as Ar increases. Conductive bridges promote this process and resistive bridges impede it.

  13. Bridging the digital divide with mobile services

    CERN Document Server

    Yelton, Andromeda

    2013-01-01

    In this issue of Library Technology Reports, Andromeda Yelton shows how libraries can build on the breadth of this population to help bridge the digital divide and provide even greater access to information. Yelton breaks down the demographics of mobile internet users, provides examples of how different libraries are reaching out to these populations, and suggests what the future may hold for this trend.

  14. Circuit bridging of components by smoke

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, T.J.; Nowlen, S.P.; Anderson, D.J. [Sandia National Labs., Albuquerque, NM (United States)

    1996-10-01

    Smoke can adversely affect digital electronics; in the short term, it can lead to circuit bridging and in the long term to corrosion of metal parts. This report is a summary of the work to date and component-level tests by Sandia National Laboratories for the Nuclear Regulatory Commission to determine the impact of smoke on digital instrumentation and control equipment. The component tests focused on short-term effects such as circuit bridging in typical components and the factors that can influence how much the smoke will affect them. These factors include the component technology and packaging, physical board protection, and environmental conditions such as the amount of smoke, temperature of burn, and humidity level. The likelihood of circuit bridging was tested by measuring leakage currents and converting those currents to resistance in ohms. Hermetically sealed ceramic packages were more resistant to smoke than plastic packages. Coating the boards with an acrylic spray provided some protection against circuit bridging. The smoke generation factors that affect the resistance the most are humidity, fuel level, and burn temperature. The use of CO{sub 2} as a fire suppressant, the presence of galvanic metal, and the presence of PVC did not significantly affect the outcome of these results.

  15. Bridges in Mathematics. WWC Intervention Report

    Science.gov (United States)

    What Works Clearinghouse, 2009

    2009-01-01

    "Bridges in Mathematics," published by the Math Learning Center (MLC), is an elementary school math curriculum covering kindergarten through fifth grade that focuses on problem solving and skill building, and applies a combination of whole-group, small-group, and independent activities. Lessons incorporate visual models, including manipulatives,…

  16. The Memory Bridge Initiative on Service Learners

    Science.gov (United States)

    Wescott, Amy; Healy, Tara C.

    2011-01-01

    This study evaluated the Memory Bridge Initiative (MBI), an educational, experiential program pairing high school students with older adults who have dementia. A qualitative, single group design with baseline and follow-up measures examined whether or not students would have a positive learning experience while gaining newfound appreciation and…

  17. Bridging the Gap: Pracademics in Foreign Policy

    Science.gov (United States)

    Murphy, Ann Marie; Fulda, Andreas

    2011-01-01

    In his seminal work "Bridging the Gap: Theory and Practice in Foreign Policy", Alexander George (1993) lamented the great divide between academia and the foreign policymaking community, arguing that greater interaction between scholars and policymakers would produce better policy. We share George's belief that scholars and practitioners each have…

  18. Ergonomic aspects of automation in navigation bridges

    NARCIS (Netherlands)

    Lazet, A.; Walraven, P.L.

    1971-01-01

    New ergonomic questions arise from the tendency toward increasing automation in maritime operations. Direct control of engines and rudder from the bridge promises improved ship control, provided that the operator can really exploit the technical improvements. To make such direct control most efficie

  19. LPN/ADN Bridge Course. Instructor's Guide.

    Science.gov (United States)

    Barrett, Jan; And Others

    This curriculum guide has been constructed in order to bridge the skills gap between licensed practical nursing (LPN) programs and associate degree nursing (ADN) programs in Missouri. The curriculum was developed through a cooperative effort by persons from both sectors. The curriculum contains four major units, each consisting of several lessons,…

  20. Journaling: A Bridge between School and Home

    Science.gov (United States)

    McGough, Julie

    2013-01-01

    This article describes how first-grade students create meaningful communication with families and help build the student-teacher-parent relationship through journaling. Journals are a useful tool to bridge school and home. A journal can communicate learning goals, develop scientific vocabulary, and create dialogue through oral and written…

  1. 75 FR 41281 - Bridge Safety Standards

    Science.gov (United States)

    2010-07-15

    ... Federal Register at 60 FR 20654, the interim statement included a request for comments to be submitted to... of Agency Policy on the Safety of Railroad Bridges (``policy statement''). See 65 FR 52667. With the... amendment. See 74 FR 157. All aspects of the policy statement that are not incorporated into the...

  2. Heavy Vehicles on Minor Highway Bridges

    DEFF Research Database (Denmark)

    Nielsen, Søren R. K.; Kirkegaard, Poul Henning; Enevoldsen, I.

    The present paper worked out as a part of a research project on "Dynamic amplification factor of vehicle loadings on smaller bridges" establishes a two-dimensional spectral description of the road roughness surface based on measurements from a Danish road using so-called Profilograph used by Dani...

  3. Bridging gaps : ten crosscurrents in media studies

    OpenAIRE

    Fornäs, Johan

    2008-01-01

    The final, definitive version of this paper has been published in: Media, Culture and Society, (30), 6, 895-905, 2008.Johan Fornäs, Bridging Gaps: Ten Crosscurrents in Media Studies.http://dx.doi.org/10.1177/0163443708096811. by SAGE Publications Ltd, All rights reserved. http://www.sagepub.com/

  4. Steel plate reinforcement of orthotropic bridge decks

    NARCIS (Netherlands)

    Teixeira de Freitas, S.

    2012-01-01

    The PhD research is focused on the reinforcement of fatigue cracked orthotropic steel bridge decks (OBD) by adding a second steel plate to the existing deck. The main idea is to stiffen the existing deck plate, which will reduce the stresses at the fatigue sensitive details and extend the fatigue li

  5. Aeroelastic Stability of Suspension Bridges using CFD

    DEFF Research Database (Denmark)

    Stærdahl, Jesper Winther; Sørensen, Niels; Nielsen, Søren R.K.

    2007-01-01

    In recent years large span suspension bridges with very thin and slender profiles have been built without proportional increasing torsional and bending stiffness. As a consequence large deformations at the mid-span can occur with risk of aeroelastic instability and structural failure. Analysis...

  6. The mechanics of ship impacts against bridges

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup; Zhang, Shengming

    1998-01-01

    a glancing blow between the ship and the bridge structure. This model is based on rigid body mechanics and well suited for inclusion in a probabilistic analysis procedure. Finally, some empirical expressions are presented which relate the energy absorbed by crushing of ship structures to the maximum impact...

  7. Fiber reinforced polymer composites for bridge structures

    Directory of Open Access Journals (Sweden)

    Alexandra CANTORIU

    2013-12-01

    Full Text Available Rapid advances in construction materials technology have led to the emergence of new materials with special properties, aiming at safety, economy and functionality of bridges structures. A class of structural materials which was originally developed many years ago, but recently caught the attention of engineers involved in the construction of bridges is fiber reinforced polymer composites. This paper provides an overview of fiber reinforced polymer composites used in bridge structures including types, properties, applications and future trends. The results of this study have revealed that this class of materials presents outstanding properties such as high specific strength, high fatigue and environmental resistance, lightweight, stiffness, magnetic transparency, highly cost-effective, and quick assembly, but in the same time high initial costs, lack of data on long-term field performance, low fire resistance. Fiber reinforced polymer composites were widely used in construction of different bridge structures such as: deck and tower, I-beams, tendons, cable stands and proved to be materials for future in this field.

  8. Bridging the Gap Between Theory and Practice

    Directory of Open Access Journals (Sweden)

    Roy H.M. Sembel

    2015-05-01

    Full Text Available Some concerns in the field of Business Management regarding the gap between theory and practice have been raised by practitioners and academicians. This keynote speech describes some lessons learned from the academic literature regarding this gap (whether the gap really exists, and if it exists, whether it needs to be bridged or closed, and how to bridge or close this gap, and shares the author's personal and professional experiences of living as both an academician and a practitioner. The main findings of this article are: (1 Yes the gap exists, however, it has to be viewed in a wider perspective to really understand the situation; (2 The gap in a specific area is bad and should become our concern, but in other areas it should not; (3 There are some ways to bridge or close the negative gap; (4 There exists hybrid career opportunities to become professionals that work both as an academician and a practitioner; (5 This new breed of hybrid professionals has a huge potential to bridge the bad theory-practice gap.

  9. Thermal Bridge Effects in Window Grooves

    DEFF Research Database (Denmark)

    Rose, Jørgen

    1997-01-01

    In this report thermal bridge effects in window grooves are analyzed. The analysis is performed using different thicknesses of the window groove insulation, to evaluate what the optimal solution is.All analysis in the report is performed using both 2- and 3-dimensional numerical analysis....

  10. Effects of hydrologic modifications on salinity and formation of hypoxia in the Mississippi River-Gulf Outlet and adjacent waterways, southeastern Louisiana, 2008 to 2012

    Science.gov (United States)

    Swarzenski, Christopher M.; Mize, Scott V.

    2014-01-01

    The Mississippi River-Gulf Outlet (MRGO) was constructed between 1958 and 1968 to provide a safer and shorter route between the Gulf of Mexico and the Port of New Orleans for ocean-going vessels. In 2006, the U.S. Congress directed the U.S. Army Corps of Engineers (USACE) to develop and implement a plan to deauthorize a portion of the MRGO ship channel from its confluence with the Gulf Intracoastal Waterway to the Gulf of Mexico. In 2009, in accordance with plans submitted to Congress, the USACE built a rock barrier across the MRGO near Hopedale, Louisiana. Following Hurricane Katrina, Congress also authorized the USACE to implement the Hurricane Storm Damage Risk Reduction System (HSDRRS) by building structures in the MRGO and adjacent surface waters, to reduce vulnerability of this area to storm surge. The HSDRRS includes the Gulf Intracoastal Waterway-Lake Borgne Surge Barrier and Gate Complex near mile 58 of the deauthorized portion of the MRGO and the Seabrook Gate Complex on the Inner Harbor Navigation Canal (IHNC). By blocking or limiting tidal exchange in the MRGO, these barriers could affect water quality in the MRGO and nearby waters including Lake Pontchartrain, the IHNC, and Lake Borgne. In 2008, the U.S. Geological Survey, in cooperation with the USACE, began a study to document the effects of the construction activities on salinity and dissolved oxygen in these surface waters. Data were collected from August 2008 through October 2012. Completion of the rock barrier in the vicinity of mile 35 in July 2009 reduced hydrologic circulation and separated the MRGO into two distinct salinity regimes, with substantially fresher conditions prevailing upstream from the rock barrier. The rock barrier also contributed to a zone of hypoxia (dissolved oxygen less than 2 milligrams per liter) that formed along the channel bottom during the warmer summer months in each year of this monitoring; the zone was much more developed downstream from the rock barrier. The most

  11. Noise Reduction of Fractional Source in Cryogenic Current Comparator Bridge

    OpenAIRE

    C. Jassadajin; Kurupakorn, C.; N. Khumthukthit; A. Pruksanubal

    2013-01-01

    In this work, a resistance measurement is done at both high accuracy and precision using Cryogenic Current Comparator (CCC) bridge system [1]. A CCC bridge circuit consists of three parts: coil, current source and detector parts. There are electronic components in the current source of the system. They generate thermal noise in the measurement system. This paper shows the noise reduction in a fractional source of CCC Bridge which is a ramp generator. The bridge receives the voltage signal, wh...

  12. Performance of damage detection methods in bridges through vibration monitoring

    OpenAIRE

    Cruz, Paulo J. S.; Salgado, R.

    2009-01-01

    The important advances achieved in the modal identification, sensors and structural monitoring of bridges have motivated the bridge engineering community to develop damage detection methods based on vibration monitoring. Some of these methods have already been demonstrated under certain conditions in bridges with deliberate damage (Farrar et al., 1998). However, the performance of these methods for damage detection in bridges has not been fully proven so far and more research n...

  13. RISK LEVEL ANALYSIS ON THE PREVENTIVE EROSION CAPACITY OF BRIDGES

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Deficiency of the Preventive Erosion Capacity (PEC) of a bridge pier is the main factor leading to bridge failures. In this paper, the PEC of bridge piers was analyzed using the stochastic analysis method. The definitions of the reliability and risk level of a bridge pier subjected to water erosion were proposed and a computational model for erosion depth and risk level in was suggested.

  14. The detection of an older population in the Magellanic Bridge

    OpenAIRE

    Bagheri, Gemma; Cioni, Maria-Rosa; Napiwotzki, Ralf

    2012-01-01

    The Magellanic system comprises the Large Magellanic Cloud (LMC), the Small Magellanic Cloud (SMC), and the less frequently observed Magellanic Bridge and Magellanic Stream. The Bridge is traced by neutral gas and has an observed stellar component, while the Stream consists of gas only, with no observed stellar counterpart to date. This study uses catalogues created in the direction of the Bridge from 2MASS and WISE to investigate the stellar content of the Magellanic Bridge. Catalogues were ...

  15. Rupture of an Evaporating Liquid Bridge between Two Grains

    OpenAIRE

    Mielniczuk, Boleslaw; El Youssoufi, Moulay Saïd; Sabatier, Laurent; Hueckel, Tomasz

    2014-01-01

    The study examines rupture of evaporating liquid bridges between two glass spheres. Evolution of the bridge profile has been recorded with the use of high-speed camera. Geometrical characteristics of the bridge were then used to calculate evolution of the variables during the process: Laplace pressure, capillary force, and surface tension force. For the purpose of reference, the bridge evolution is followed also during kinematic extension. During both processes the diameter of the neck decrea...

  16. TorBricks: Blocking-Resistant Tor Bridge Distribution

    OpenAIRE

    Zamani, Mahdi; Saia, Jared; Crandall, Jedidiah

    2016-01-01

    Tor is currently the most popular network for anonymous Internet access. It critically relies on volunteer nodes called bridges for relaying Internet traffic when a user's ISP blocks connections to Tor. Unfortunately, current methods for distributing bridges are vulnerable to malicious users who obtain and block bridge addresses. In this paper, we propose TorBricks, a protocol for distributing Tor bridges to n users, even when an unknown number t < n of these users are controlled by a malicio...

  17. Railroad Bridges in Louisiana, Geographic NAD83, FEMA (1997) [railroad_bridges_FEMA_1997

    Data.gov (United States)

    Louisiana Geographic Information Center — This is is a point dataset for the locations and attributes of 32 Louisiana railroad bridges. The attributes include city (nearest?), county (sic), routefrom...

  18. Nondestructive evaluation inspection of the Arlington Memorial Bridge using a robotic assisted bridge inspection tool (RABIT)

    Science.gov (United States)

    Gucunski, Nenad; Boone, Shane D.; Zobel, Rob; Ghasemi, Hamid; Parvardeh, Hooman; Kee, Seong-Hoon

    2014-04-01

    The information presented in this report provides a detailed assessment of the condition of the Arlington Memorial Bridge (AMB) deck. The field-data collection was obtained by both the RABIT™ Bridge Inspection Tool and a number of semi-automated non-destructive evaluation (NDE) tools. The deployment of the semi-automated NDE tools was performed to inspect the AMB deck condition and also to validate data obtained by the RABIT™ Bridge Inspection Tool. Data mining and analysis were accomplished through enhanced data interpretation and visualization capabilities using advanced data integration, fusion, and 2D rendering. One of the major challenges that the research team had to overcome in assessing the condition of the AMB deck was the presence of an asphalt overlay on the entire bridge deck.

  19. Performance Assessment of Bridges Using GPS: The Juarez Bridge in Culiacan, Mexico

    Science.gov (United States)

    Vazquez, G. E.; Gaxiola-Camacho, J. R.; Trejo, M.; Echagaray, J.; Guzman, G. M.

    2015-12-01

    Performance assessment of bridges has become very important during recent years. Bridges around the world are aging, leading to the incorporation of efficient, reliable, and economic evaluation procedures. These techniques must assess properly the performance of bridges under several loading conditions in a real manner, representing the physics of the problem. Among several approaches, Global Positioning System (GPS) can be intelligently used for the performance evaluation of bridges. We focused on GPS, since it naturally produces position estimates as compared to seismic instruments that record either velocity or acceleration, and thus require an integration. There are several reasons that make the Juarez Bridge a case of study for evaluation: it is approximately 45 years old, it is a reinforced concrete structure, it connects two significant zones of the city, and its spans is closely to 200 meters long. In addition, thousands of vehicles and pedestrians use the Juarez Bridge every day, which make feasible the GPS performance assessment. Hence, in order to produce optimal position estimates, GPS data were collected during two consecutive hours at three different periods of the day for a whole week (Monday through Sunday), to represent three critical limit states of the bridge (mid-span and end-spans). GPS data were processed using the GAMIT/GLOBK software, considering 1-second sampling rate, 15-degree cutoff angle, ionosphere-free double-differenced (DD) carrier phase method, and precise final orbits disseminated by IGS (International GNSS Service). The displacements obtained from the above discussed procedure are compared with allowable values documented in bridge construction manuals. Reliability theory was used to evaluate the probability of failure of the bridge for the three periods of the day. In addition, a conclusion was made about the most risky day of the week for the use of the Juarez Bridge. It is expected that the results from the proposed research

  20. Building water bridges in air: Electrohydrodynamics of the Floating Water Bridge

    OpenAIRE

    Marin, Alvaro G.; Lohse, Detlef

    2010-01-01

    The interaction of electrical fields and liquids can lead to a phenomenon that defies intuition. Some famous examples can be found in electrohydrodynamics as Taylor cones, whipping jets, or noncoalescing drops. A less famous example is the floating water bridge: a slender thread of water held between two glass beakers in which a high voltage difference is applied. Surprisingly, the water bridge defies gravity even when the beakers are separated at distances up to 2 cm. In this paper, experime...

  1. Spectroscopic Studies of Bridge Contributions to Electronic Coupling in a Donor-Bridge-Acceptor Biradical System

    OpenAIRE

    Kirk, Martin L.; Shultz, David A.; Depperman, Ezra C.; Habel-Rodriguez, Diana; Schmidt, Robert D.

    2012-01-01

    Variable temperature electronic absorption and resonance Raman spectroscopies are used to probe the excited state electronic structure of TpCum,MeZn(SQ-Ph-NN) (1) – a donor-bridge-acceptor (D-B-A) biradical complex and a ground state analog of the charge-separated excited state formed in photoinduced electron transfer reactions. Strong ferromagnetic exchange coupling that is mediated by the para-phenylene bridge stabilizes the triplet ground state of this molecule. Detailed spectroscopic and ...

  2. 49 CFR 237.31 - Adoption of bridge management programs.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Adoption of bridge management programs. 237.31 Section 237.31 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Adoption of bridge management programs. Each track owner shall adopt a bridge safety management program...

  3. Ambient Response Analysis of the Great Belt Bridge

    DEFF Research Database (Denmark)

    Brincker, Rune; Frandsen, J. B.; Andersen, P.

    2000-01-01

    In this paper an ambient response analysis of the Great Belt Bridge is presented. The Great Belt Bridge is one of the largest suspension bridges in the world, and the analysis was carried out in order to investigate the possibilities of estimating reliable damping values from the ambient response...

  4. 23 CFR 650.409 - Evaluation of bridge inventory.

    Science.gov (United States)

    2010-04-01

    ... BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.409... establishing eligibility and priority for replacement or rehabilitation of bridges; in general the lower the... State program. After evaluation of the inventory and assignment of sufficiency ratings, the...

  5. Reduction of Impact Noise of Trams on a Major Bridge

    NARCIS (Netherlands)

    Dittrich, M.G.; Bosshaart, C.; Wessels, P.W.

    2015-01-01

    As part of a recent renovation of the Erasmus bridge in Rotterdam, improvements were made to reduce impact noise caused by trams passing a series of rai! joints. The bridge inciudes several different sections inciuding a bascule bridge and is in an inner city tocation with new adjacent apartment bui

  6. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Temporary crown and bridge resin. 872.3770 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device composed of a material, such...

  7. Resin-Bonded Bridges in vitro and in vivo

    NARCIS (Netherlands)

    Veen, Johannes Hilbrandt van der

    1988-01-01

    In this thesis in vitro and in vivo studies on the clinical application of resin-bonded bridges are described and discussed. The development of different types of resin-bonded bridges is described in chapter 1. The bridges are often made by boding a cast metal retainer fitted with and artificial too

  8. Bridged Quaterphenyls as Flashlamp-Pumpable Laser Dyes

    OpenAIRE

    Kauffman, Joel M; Kelley, Charles J.; Ghiorghis, Alem; Neister, Edward; Armstrong, Lorne; Prause, Paul R.

    1987-01-01

    Partial bridging of the o,o′ positions of the aromatic rings in quaterphenyl gave superior flashlamp-pumpable laser dyes. Alkyl-substituted carbon bridges gave superior dyes to those containing oxygen or alkyl-substituted nitrogen or silicon bridges. Dyes lasing in the 365–390 nm region with improved energy output, lifetime and solubility were discovered.

  9. Improving the Dynamics of Suspension Bridges using Active Control Systems

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    Improving the dynamics of suspension bridge using active control is discussed in this paper. The main dynamic problem with long suspension bridges is the aeroelastic phenomenon called flutter. Flutter oscillations of a bridge girder is a stability problem and the oscillations are perpendicular...

  10. Renovation techniques for fatigue cracked orthotropic steel bridge decks

    NARCIS (Netherlands)

    de Jong, F.B.P.

    2007-01-01

    This dissertation presents the research into renovation techniques for orthotropic steel bridge decks. These techniques are needed to solve fatigue problems in the decks of these bridges, as several fatigue cracks have been detected in the deck structure of these bridges the last decade. A well-know

  11. Road Bridges and Culverts, Bridges layers located in GIS and Transportation database., Published in unknown, City of Roswell, GA.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Road Bridges and Culverts dataset as of unknown. It is described as 'Bridges layers located in GIS and Transportation database.'. Data by this publisher are...

  12. Innovative 'Artificial Mussels' technology for assessing spatial and temporal distribution of metals in Goulburn-Murray catchments waterways, Victoria, Australia: effects of climate variability (dry vs. wet years).

    Science.gov (United States)

    Kibria, Golam; Lau, T C; Wu, Rudolf

    2012-12-01

    The "Artificial mussel" (AM), a novel passive sampling technology, was used for the first time in Australia in freshwater to monitor and assess the risk of trace metals (Cd, Cu, Hg, Pb, and Zn). AMs were deployed at 10 sites within the Goulburn-Murray Water catchments, Victoria, Australia during a dry year (2009-2010) and a wet year (2010-2011). Our results showed that the AMs accumulated all the five metals. Cd, Pb, Hg were detected during the wet year but below detection limits during the dry year. At some sites close to orchards, vine yards and farming areas, elevated levels of Cu were clearly evident during the dry year, while elevated levels of Zn were found during the wet year; the Cu indicates localized inputs from the agricultural application of copper fungicide. The impacts from old mines were significantly less compared 'hot spots'. Our study demonstrated that climate variability (dry, wet years) can influence the metal inputs to waterways via different transport pathways. Using the AMs, we were able to identify various 'hot spots' of heavy metals, which may pose a potential risk to aquatic ecosystems (sub-lethal effects to fish) and public (via food chain metal bioaccumulation and biomagnification) in the Goulburn-Murray Water catchments. The State Protection Policy exempted artificial channels and drains from protection of beneficial use (including protection of aquatic ecosystems) and majority of sites ('hot spots') were located within artificial irrigation channels. PMID:23070068

  13. PARAMETRIC STUDY OF SKEW ANGLE ON BOX GIRDER BRIDGE DECK

    OpenAIRE

    Shrikant D. Bobade *, Dr. Valsson Varghese

    2016-01-01

    Box girder bridge deck, is the most common type of bridges in world and India, it consists of several Slab or girders. The span in the direction of the roadway and connected across their tops and bottoms by a thin continuous structural stab, the longitudinal box girders can be made of steel or concrete. The Simple supported single span concrete bridge deck is presented in present study. Skewed bridges are suitable in highway design when the geometry of straight bridges is not possible. The sk...

  14. Ambient Modal Testing of the Vestvej Bridge using Random Decrement

    DEFF Research Database (Denmark)

    Asmussen, J. C.; Brincker, Rune; Rytter, A.

    This paper presents an ambient vibration study of the Vestvej Bridge. The bridge is a typically Danish two-span concrete bridge which crosses a highway. The purpose of the study is to perform a pre-investigation of the dynamic behavior to obtain information for the design of a demonstration project...... concerning application of vibration based inspection of bridges. The data analysis process of ambient vribration testing of bridges has traditionally been based on auto and cross spectral densities estimated using an FFT algorithm. In the pre-analysis state the spectral densities are all averaged to obtain...

  15. Ambient Modal Testing of the Vestvej Bridge using Random Decrement

    DEFF Research Database (Denmark)

    Asmussen, J. C.; Brincker, Rune; Rytter, A.

    1998-01-01

    This paper presents an ambient vibration study of the Vestvej Bridge. The bridge is a typically Danish two-span concrete bridge which crosses a highway. The purpose of the study is to perform a pre-investigation of the dynamic behavior to obtain information for the design of a demonstration project...... concerning application of vibration based inspection of bridges. The data analysis process of ambient vribration testing of bridges has traditionally been based on auto and cross spectral densities estimated using an FFT algorithm. In the pre-analysis state the spectral densities are all averaged to obtain...

  16. Seismic Passive Control of Cable-Stayed Bridges

    Directory of Open Access Journals (Sweden)

    Hosam-Eddin M. Ali

    1995-01-01

    Full Text Available A three-dimensional modeling procedure is proposed for cable-stayed bridges with rubber, steel, and lead energy dissipation devices. The passive control technique is investigated by considering the response of bridge models with and without energy dissipation devices. The impact of various design parameters on the seismic response of current and future bridge designs is studied. Appropriate locations and properties of the passive devices can achieve better performance for cable-stayed bridges by balancing the significant reduction in earthquake-induced forces against tolerable displacements. Proper design of passive systems can help provide solutions for retro-fitting some existing bridges.

  17. Dynamic analysis of rail transit elevated bridge with ladder track

    Institute of Scientific and Technical Information of China (English)

    He XIA; Yushu DENG; Yongwei ZOU; Guido DE ROECK; Geert DEGRANDE

    2009-01-01

    In this paper, a dynamic analysis model of an elevated bridge with ladder tracks under moving train load is established. The whole process of a train running through an elevated bridge at different speeds is simulated.The dynamic responses of the elevated bridge with ladder track and the running safety and comfort index of train vehicles are evaluated. Compared with the dynamic responses of an elevated bridge with ordinary non-ballasted slab track, the ladder track's effect on reducing the vibration of an elevated bridge is analyzed. The analysis results show that the ladder track has good vibration reduction characteristics as compared to ordinary non-ballasted track.

  18. Suspension Bridge Flutter for Girder with Separate Control Flaps

    DEFF Research Database (Denmark)

    Huynh, T.; Thoft-Christensen, Palle

    Active vibration control of long span suspension bridge flutter using separated control flaps (SFSC) has shown to increase effectively the critical wind speed of bridges. In this paper, an SFSC calculation based on modal equations of the vertical and torsional motions of the bridge girder including...... the flaps is presented. The length of the flaps attached to the girder, the flap configuration and the flap rotational angles are parameters used to increase the critical wind speed of the bridge. To illustrate the theory a numerical example is shown for a suspension bridge of 1000m+2500m+1000m span based...

  19. Cross-bridge model of muscle contraction. Quantitative analysis.

    OpenAIRE

    Eisenberg, E.; Hill, T L; Chen, Y.

    1980-01-01

    We recently presented, in a qualitative manner, a cross-bridge model of muscle contraction which was based on a biochemical kinetic cycle for the actomyosin ATPase activity. This cross-bridge model consisted of two cross-bridge states detached from actin and two cross-bridge states attached to actin. In the present paper, we attempt to fit this model quantitatively to both biochemical and physiological data. We find that the resulting complete cross-bridge model is able to account reasonably ...

  20. Excitation of Arch and Suspension Bridges by Subwires

    Directory of Open Access Journals (Sweden)

    Noriaki Hiwatashi

    1993-01-01

    Full Text Available A force generation method using a subwire for arch and suspension bridges is proposed. The subwire is connected to the arch or the cable of the bridge through rollers. The uniform force produced by pulling and releasing the pretensioned subwires acts on the bridge as an externalforce. A new device called “the resonance force generator” is also developed to excite the bridges by applying a small force. To verify the proposed concept, a stress ribbon bridge was excited with the resonance force generator.

  1. Excitation of Arch and Suspension Bridges by Subwires

    OpenAIRE

    Noriaki Hiwatashi; Yoji Mizuta; Yutaka Ishihara; Itio Hirai

    1993-01-01

    A force generation method using a subwire for arch and suspension bridges is proposed. The subwire is connected to the arch or the cable of the bridge through rollers. The uniform force produced by pulling and releasing the pretensioned subwires acts on the bridge as an externalforce. A new device called “the resonance force generator” is also developed to excite the bridges by applying a small force. To verify the proposed concept, a stress ribbon bridge was excited with the resonance force ...

  2. Violin Bridge Mobility Analysis under In-Plane Excitation

    OpenAIRE

    Cheng-Zhong Zhang; Guang-Ming Zhang; Bang-Yan Ye; Li-Dong Liang

    2013-01-01

    The vibration of a violin bridge is a dynamic contact vibration with two interfaces: strings-bridge, and bridge feet-top plate. In this paper, the mobility of an isolated bridge under in-plane excitation is explored using finite element modeling based on the contact vibration model. Numerical results show that the dynamic contact stiffness in the two contact interfaces has a great impact on the bridge mobility. A main resonance peak is observed in the frequency range of 2–3 kHz in the frequen...

  3. Translating Climate Projections for Bridge Engineering

    Science.gov (United States)

    Anderson, C.; Takle, E. S.; Krajewski, W.; Mantilla, R.; Quintero, F.

    2015-12-01

    A bridge vulnerability pilot study was conducted by Iowa Department of Transportation (IADOT) as one of nineteen pilots supported by the Federal Highway Administration Climate Change Resilience Pilots. Our pilot study team consisted of the IADOT senior bridge engineer who is the preliminary design section leader as well as climate and hydrological scientists. The pilot project culminated in a visual graphic designed by the bridge engineer (Figure 1), and an evaluation framework for bridge engineering design. The framework has four stages. The first two stages evaluate the spatial and temporal resolution needed in climate projection data in order to be suitable for input to a hydrology model. The framework separates streamflow simulation error into errors from the streamflow model and from the coarseness of input weather data series. In the final two stages, the framework evaluates credibility of climate projection streamflow simulations. Using an empirically downscaled data set, projection streamflow is generated. Error is computed in two time frames: the training period of the empirical downscaling methodology, and an out-of-sample period. If large errors in projection streamflow were observed during the training period, it would indicate low accuracy and, therefore, low credibility. If large errors in streamflow were observed during the out-of-sample period, it would mean the approach may not include some causes of change and, therefore, the climate projections would have limited credibility for setting expectations for changes. We address uncertainty with confidence intervals on quantiles of streamflow discharge. The results show the 95% confidence intervals have significant overlap. Nevertheless, the use of confidence intervals enabled engineering judgement. In our discussions, we noted the consistency in direction of change across basins, though the flood mechanism was different across basins, and the high bound of bridge lifetime period quantiles exceeded

  4. Bridge health assessment system with fatigue analysis algorithm

    Science.gov (United States)

    Wang, Xuan; Wang, M. L.; Zhao, Yang

    2005-05-01

    A modern bridge is such a complicated system that is difficult to analyze by conventional mathematic tools. A rational bridge monitoring requires a good knowledge of the actual condition of various structural components. Fatigue analysis of concrete bridges is one of the most important problems. Concrete bridges are often undergoing a fatigue deterioration, starting with cracking and ending with large holes through the web. There is a need for the development of efficient health assessment system for fatigue evaluation and prediction of the remaining life. This information has clear economical consequences, as deficient bridges must be repaired or closed. The goal of this research is to provide a practical expert system in bridge health evaluation and improve the understanding of bridge behavior during their service. Efforts to develop a functional bridge monitoring system have mainly been concentrated upon successful implementation of experienced-based machine learning. The reliability of the techniques adopted for damage assessment is also important for bridge monitoring systems. By applying the system to an in-service PC bridge, it has been verified that this fuzzy logic expert system is effective and reliable for the bridge health evaluation.

  5. A Review of Indirect Bridge Monitoring Using Passing Vehicles

    Directory of Open Access Journals (Sweden)

    Abdollah Malekjafarian

    2015-01-01

    Full Text Available Indirect bridge monitoring methods, using the responses measured from vehicles passing over bridges, are under development for about a decade. A major advantage of these methods is that they use sensors mounted on the vehicle, no sensors or data acquisition system needs to be installed on the bridge. Most of the proposed methods are based on the identification of dynamic characteristics of the bridge from responses measured on the vehicle, such as natural frequency, mode shapes, and damping. In addition, some of the methods seek to directly detect bridge damage based on the interaction between the vehicle and bridge. This paper presents a critical review of indirect methods for bridge monitoring and provides discussion and recommendations on the challenges to be overcome for successful implementation in practice.

  6. Evaluating the life cycle environmental impact of short span bridges

    DEFF Research Database (Denmark)

    Du, Guangli; Pettersson, Lars; Karoumi, Raid

    2016-01-01

    Bridge infrastructure consumes large amount of energy and raw materials, leading to considerable environmental burdens. The traditional infrastructure construction prioritizes its technical and economic viability. In recent years, the society devotes an ever-increased attention to the environmental...... impact of the construction sector. Life cycle assessment (LCA) is a systematic method for assessing the environmental impact of products and systems, but its application in bridges is scarce. In Swede, most of the bridges are short spans and the type of concrete slab-frame bridge (CFB) accounts...... for a large share. Soil steel composite bridge (SSCB) is a functional equivalent solution for CFB. In order to mitigate the environmental burdens of short span bridges, this paper performed a comparative LCA study between these two types of bridge. The results indicate that the initial material consumption...

  7. Online Bridge Crack Monitoring with Smart Film

    Directory of Open Access Journals (Sweden)

    Benniu Zhang

    2013-01-01

    Full Text Available Smart film crack monitoring method, which can be used for detecting initiation, length, width, shape, location, and propagation of cracks on real bridges, is proposed. Firstly, the fabrication of the smart film is developed. Then the feasibility of the method is analyzed and verified by the mechanical sensing character of the smart film under the two conditions of normal strain and crack initiation. Meanwhile, the coupling interference between parallel enameled wires of the smart film is discussed, and then low-frequency detecting signal and the custom communication protocol are used to decrease interference. On this basis, crack monitoring system with smart film is designed, where the collected crack data is sent to the remote monitoring center and the cracks are simulated and recurred. Finally, the monitoring system is applied to six bridges, and the effects are discussed.

  8. Bridge Condition Assessment Using D Numbers

    Directory of Open Access Journals (Sweden)

    Xinyang Deng

    2014-01-01

    Full Text Available Bridge condition assessment is a complex problem influenced by many factors. The uncertain environment increases more its complexity. Due to the uncertainty in the process of assessment, one of the key problems is the representation of assessment results. Though there exists many methods that can deal with uncertain information, however, they have more or less deficiencies. In this paper, a new representation of uncertain information, called D numbers, is presented. It extends the Dempster-Shafer theory. By using D numbers, a new method is developed for the bridge condition assessment. Compared to these existing methods, the proposed method is simpler and more effective. An illustrative case is given to show the effectiveness of the new method.

  9. Accelerated aging of polymer composite bridge materials

    Science.gov (United States)

    Carlson, Nancy M.; Blackwood, Larry G.; Torres, Lucinda L.; Rodriguez, Julio G.; Yoder, Timothy S.

    1999-05-01

    Accelerated aging research on samples of composite materials and candidate UV protective coatings is determining the effects of six environmental factors on material durability. Candidate fastener materials are being evaluated to determine corrosion rates and crevice corrosion effects at load-bearing joints. This work supports field testing of a 30-ft long, 18-ft wide polymer matrix composite (PMC) bridge at the Idaho National Engineering and Environmental Laboratory. Durability results and sensor data form test with live loads provide information required for determining the cost/benefit measures to use in life-cycle planning, determining a maintenance strategy, establishing applicable inspection techniques, and establishing guidelines, standards and acceptance criteria for PMC bridges for use in the transportation infrastructure.

  10. Tacoma Bridge Failure-- a Physical Model

    CERN Document Server

    Green, D; Green, Daniel; Unruh, William G.

    2004-01-01

    The cause of the collapse of the Tacoma Narrows Bridge has been a topic of much debate and confusion since the day it fell. Many mischaracterizations of the observed phenomena have limited the widespread understanding of the problem. Nevertheless, there has always been an abundance of evidence in favour of a negative damping model. Negative damping, or positive feedback, is responsible for many large amplitude oscillations observed in many applications. In this paper, we will explain some well-known examples of positive feedback. We will then present a feedback model, derived from fundamental physics, capable of explaining a number of features observed in the instabilities of many bridge decks. This model is supported by computational, experimental and historical data.

  11. Fatigue-Prone Details in Steel Bridges

    Directory of Open Access Journals (Sweden)

    Mohsen Heshmati

    2012-11-01

    Full Text Available This paper reviews the results of a comprehensive investigation including more than 100 fatigue damage cases, reported for steel and composite bridges. The damage cases are categorized according to types of detail. The mechanisms behind fatigue damage in each category are identified and studied. It was found that more than 90% of all reported damage cases are of deformation-induced type and generated by some kind of unintentional or otherwise overlooked interaction between different load-carrying members or systems in the bridge. Poor detailing, with unstiffened gaps and abrupt changes in stiffness at the connections between different members were also found to contribute to fatigue cracking in many details.

  12. A liquid bridge connecting moving porous surfaces

    Science.gov (United States)

    Gharib, Morteza; Gat, Amir; Navaz, Homayun

    2011-11-01

    We study the coupled problem of a liquid bridge connecting two porous surfaces where the gap between the surfaces is an externally controlled function of time. The relative motion between the surfaces affects the geometry and the pressure distribution of the liquid bridge, thus influencing the diffusion speed and penetration topology within the porous material. Utilizing the lubrication approximation and Darcy's phenomenological law we obtain a relation between the diffusion into the porous surface and the relative motion between the surfaces. A scheme to control the diffusion topology is presented and illustrated for the case of conical penetration topology with an arbitrary cone opening angle. Analytic expressions describing the penetration topology for the case of constant speed of the surfaces and the relative motion between the surfaces required to create a conical penetration topology are obtained and compared to experimental and numerical data. This project was supported by the Defense Threat Reduction Agency (DTRA), Award Number: 330233-A.

  13. Bridging the Divide between Science and Journalism

    OpenAIRE

    Marincola Francesco M; Van Eperen Laura; Strohm Jennifer

    2010-01-01

    Abstract There are countless reasons nearly every scientist should learn how to communicate effectively with the media, including increased understanding of critical research findings to attract or sustain funding and build new professional partnerships that will further propel forward research. But where do scientists begin? Bridging the Divide between Science and Journalism offers practical tips for any scientist looking to work with the media. Given the traditional and internet-based sourc...

  14. Fatigue-Prone Details in Steel Bridges

    OpenAIRE

    Mohsen Heshmati; Mohammad Al-Emrani; Reza Haghani

    2012-01-01

    This paper reviews the results of a comprehensive investigation including more than 100 fatigue damage cases, reported for steel and composite bridges. The damage cases are categorized according to types of detail. The mechanisms behind fatigue damage in each category are identified and studied. It was found that more than 90% of all reported damage cases are of deformation-induced type and generated by some kind of unintentional or otherwise overlooked interaction between different load-carr...

  15. Design of bridges against large tectonic deformation

    Institute of Scientific and Technical Information of China (English)

    I.Anastasopoulost; G.Gazetas; V.Drosos; T.Georgarakos; R.Kourkoulis

    2008-01-01

    The engineering community has devoted much effort to understanding the response of soil-structure systems to seismic ground motions,but little attention to the effects of an outcropping fault offset.The 1999 earthquakes of Turkey and Taiwan,offering a variety of case histories of structural damage due to faulting,have (re)fueled the interest on the subject.This paper presents a methodology for design of bridges against tectonic deformation.The problem is decoupled in two analysis steps:the first (at the local level) deals with the response of a single pier and its foundation to fault rupture propagating through the soil,and the superstructure is modeled in a simplified manner;and the second (at the global level)investigates detailed models of the superstructure subjected to the support (differential) displacements of Step 1.A parametric study investigates typical models of viaduct and overpass bridges,founded on piles or caissons.Fixed-head piled foundations are shown to be rather vulnerable to faulting-induced deformation.End-bearing piles in particular are unable to survive bedrock offsets exceeding 10 cm.Floating piles perform better,and if combined with hinged pile-to-cap connections,they could survive much larger offsets.Soil resilience is beneficial in reducing pile distress.Caisson foundations are almost invariably successful.Statically-indeterminate superstructures are quite vulnerable,while statically-determinate are insensitive (allowing differential displacements and rotations without suffering any distress).For large-span cantilever construction bridges,where a statically determinate system is hardly an option,inserting resilient seismic isolation bearings is advantageous as long as ample seating can prevent the deck from falling off the supports.An actual application of the developed method is presented for a major bridge,demonstrating the feasibility of design against tectonic deformation.

  16. Bridge Inspections and Being an ERC

    OpenAIRE

    Hoernschemeyer, Keith; Miller, Jessica

    2015-01-01

    This presentation will discuss recent changes to the County Bridge Inspection Program from the perspective of both the FHWA and INDOT. We will also discuss the responsibilities of the local public agency’s (LPA’s) employee in responsible charge (ERC) with respect to managing this program. As this course is a yearly requirement, all county ERCs are encouraged to attend. Pre-registering is strongly encouraged by e-mailing your contact information to .

  17. Liquid bridge simulations with OpenFOAM

    OpenAIRE

    Guirao Aguilar, Guillermo

    2011-01-01

    Any liquid-gas interface being under a temperature gradient is subject to a thermocapillary flow generated by the differences in the surface tension. In the particular case of liquid bridges, this flow can evolve into a oscillatory or travelling flow known as hydrothermal wave. This works aims to achieve a better understanding of the formation of this kind of flow by means of computational fluid dynamics techniques using a specific software package. For that, a simplified model of the liquid ...

  18. Legendrian framings for two-bridge links

    CERN Document Server

    Baader, Sebastian

    2009-01-01

    We define the Thurston-Bennequin polytope of a two-component link as the convex hull of all pairs of integers that arise as framings of a Legendrian representative. The main result of this paper is a description of the Thurston-Bennequin polytope for two-bridge links. As an application, we construct non-quasipositive surfaces in $\\R^3$ all whose sub-annuli are quasipositive.

  19. Ether bridge formation in loline alkaloid biosynthesis

    OpenAIRE

    Pan, Juan; Bhardwaj, Minakshi; Faulkner, Jerome R.; Nagabhyru, Padmaja; Charlton, Nikki D.; Higashi, Richard M.; Miller, Anne-Frances; Young, Carolyn A; Grossman, Robert B.; Schardl, Christopher L

    2013-01-01

    Lolines are potent insecticidal agents produced by endophytic fungi of cool-season grasses. These alkaloids are composed of a pyrrolizidine ring system and an uncommon ether bridge linking carbons 2 and 7. Previous results indicated that 1-aminopyrrolizidine was a pathway intermediate. We used RNA interference to knock down expression of lolO, resulting in the accumulation of a novel alkaloid identified as exo-1-acetamidopyrrolizidine based on high-resolution MS and NMR. Genomes of endophytes...

  20. Bridging the Gap: Linking Simulation and Testing

    Energy Technology Data Exchange (ETDEWEB)

    Krajewski, Paul E.; Carsley, John; Stoudt, Mark R.; Hovanski, Yuri

    2012-09-01

    The Materials Genome Initiative (MGI) which is a key enabler for the Advanced Manufacturing Partnership, announced in 2011 by U.S. President Barack Obama, was established to accelerate the development and deployment of advanced materials. The MGI is driven by the need to "bridge the gap" between (I) experimental results and computational analysis to enable the rapid development and validation of new mateirals, and (II) the processes required to convert these materials into useable goods.

  1. Bridge concrete deteriorating diagnosis by infrared thermography

    Science.gov (United States)

    Shibata, Hiroki; Fukuyama, Nobuhiro; Sakuma, Joji; Mochizuki, Jun; Kimura, Yukinori

    2006-04-01

    Bridge is indispensable as social overhead capital. In the past, concrete construction was believed to be semi-permanent. Actually, however, concrete is deteriorated by various factors including seawater damage, annual temperature change, etc. Therefore, it is now obvious that maintenance and management are essential to keep performance of the bridge. In Japan, we had many reports of using infrared thermography for diagnosis of building, mainly for delamination of tile and mortar used for surface of the building for more than 10 years. In recent years, infrared thermogrephy is more actively used for delamination of surface of the bridge. Passive method is usually used for open-air concrete structure diagnosis, which utilizes intraday environmental temperature change and/or radiation energy emitted from the sun which create delta-T of delamination portion of the concrete structure. It is very important to take thermal image at right conditions. Otherwise, you may easily fall onto false diagnosis. In our presentation, many case examples and study of thermal data will be shown, which are taken at the right condition.

  2. Review on Research Progress of Anti-collision Equipment for Bridge Protection%桥梁防船撞措施研究进展综述

    Institute of Scientific and Technical Information of China (English)

    沈自力

    2015-01-01

    In recently,actively photoelectric early-warning system and composite material have been developed for bridge piers against ship collision.The present paper introduced the reseach work ac-cording to the latest reseach progress of anti-collision equipment.The paper mainly classified and re-viewed for passive anti-collision equipment ,analyzed the performance characteristics and application conditions of different types of anti-collision equipment,and put forward some ideas for how to chose the anti-collision equipments according to the level of waterway.%近年来出现了一些光电预警主动防撞系统,以及复合材料的新型防撞装置。文中根据桥梁防撞装置的最新研究进展,介绍了主动防船撞系统的研究概况,重点对被动防撞装置进行了系统的分类和评述,分析了不同类型防撞装置的性能特点以及适用环境,提出了不同通航等级下,如何选择桥梁防撞装置的一些思路。

  3. Building water bridges in air: Electrohydrodynamics of the Floating Water Bridge

    CERN Document Server

    Marin, Alvaro G

    2010-01-01

    The interaction of electrical fields and liquids can lead to phenomena that defies intuition. Some famous examples can be found in Electrohydrodynamics as Taylor cones, whipping jets or non-coalescing drops. A less famous example is the Floating Water Bridge: a slender thread of water held between two glass beakers in which a high voltage difference is applied. Surprisingly, the water bridge defies gravity even when the beakers are separated at distances up to 2 cm. In the presentation, experimental measurements and simple models are proposed and discussed for the stability of the bridge and the source of the flow, revealing an important role of polarization forces on the stability of the water bridge. On the other hand, the observed flow can only be explained due to the non negligible free charge present in the surface. In this sense, the Floating Water Bridge can be considered as an extreme case of a leaky dielectric liquid (J. R. Melcher and G. I. Taylor, Annu. Rev. Fluid Mech., 1:111, 1969).

  4. SMART BRIDGE: A tool for estimating the military load classification of bridges using varying levels of information

    Energy Technology Data Exchange (ETDEWEB)

    Van Groningen, C.N.; Paddock, R.A.

    1997-03-01

    A major consideration in planning and executing military deployments is determining the routes available for moving troops and equipment. Part of this planning ensures that all of the bridges along the routes can support the specialized equipment needed. Because few trained and experienced bridge analysts are available, and automated tool is required to help military engineers and planners quickly and accurately determine the capacity, or the military load classification, of bridges. However, because detailed information about each bridge may not always be available, the tool also needs to include alternative methods for estimating bridge capacities. SMART BRIDGE, developed by Argonne National Laboratory, provides this capacity. The tool consists of a collection of modules that interact with each other to accommodate various bridge types, analytical techniques, and database functions. 5 refs., 6 figs., 2 tabs.

  5. The Internet Inter-Orb Protocol Security Bridge

    Directory of Open Access Journals (Sweden)

    Pawel Slowikowski

    1999-01-01

    Full Text Available In this paper, we present a security bridge for the Internet protocol of interoperability amongst CORBA objects and the Internet inter-ORB Protocol (IIOP. The bridge helps in making accessible objects in the Internet and makes possible the access control to them. The bridge was realized in the popular request broker the Visigenic's VisiBroker under Windows 95/NT and Solaris 2.X operating systems. We describe two ways of locating the bridge in the request broker. The first means uses one name domain of broker and is not transparent for client. The second one uses two name domains and provides objects protection on the level of the Naming Service and is transparent lor the client. We also describe the variant ofthe second means with using GateKeeper server to support IIOP tunneling within HTTP. We emphasize the importance of a firewall, cooperating with a bridge. which is required for the purpose of providing object protection. The paper presents an original conception of security managing, basing on the ideas of users, groups and resources defined using the standard terms of CORBA, IIOP and TCP/IP, that allows to control positively and negatively the access to classes (interfaces, objects and also to their individual methods. This conception was effectively implemented in a functioning bridge. Further chapters describe the foundations and some details of the bridge implementation sueli as the use ofthe Interface Repository, cache memory application, thread synchronization and the way of synchronization of the configuration applet with the bridge's objects. We discuss the influence of these solutions on the efficiency ofthe bridge and its source code portability. We also present the general structure of the component objects ofthe bridge with a scheme. ln the next part we characterize the implementation foundations ofthe bridge manager, realized as an applet in Java, with the stress on the possibility of the bridge configuration through the

  6. Bridges analysis, design, structural health monitoring, and rehabilitation

    CERN Document Server

    Bakht, Baidar

    2015-01-01

    This book offers a valuable guide for practicing bridge engineers and graduate students in structural engineering; its main purpose is to present the latest concepts in bridge engineering in fairly easy-to-follow terms. The book provides details of easy-to-use computer programs for: ·      Analysing slab-on-girder bridges for live load distribution. ·      Analysing slab and other solid bridge components for live load distribution. ·      Analysing and designing concrete deck slab overhangs of girder bridges under vehicular loads. ·      Determining the failure loads of concrete deck slabs of girder bridges under concentrated wheel loads. In addition, the book includes extensive chapters dealing with the design of wood bridges and soil-steel bridges. Further, a unique chapter on structural health monitoring (SHM) will help bridge engineers determine the actual load carrying capacities of bridges, as opposed to their perceived analytical capacities. The chapter addressing structures...

  7. Field Tests and Simulation of Lion-Head River Bridge

    Directory of Open Access Journals (Sweden)

    Yao-Min Fang

    2007-01-01

    Full Text Available Lion-Head River Bridge is a twin bridge in parallel position. The east-bounded was designed and constructed as a traditional prestress concrete box girder bridge with pot bearings; and the west-bounded was installed with seismic isolation devices of lead rubber bearings. The behavior of the isolated bridge is compared with that of the traditional bridge through several field tests including the ambient vibration test, the force vibration test induced by shakers, the free vibration test induced by a push and fast release system, and the truck test. The bridges suffered from various extents of damage due to the Chi-Chi and the Chi-I earthquakes of great strength during the construction and had been retrofitted. The damage was reflected by the change of the bridges' natural frequencies obtained from the ambient vibration tests. The models of the two bridges are simulated by the finite element method based on the original design drawings. Soil-structure interaction was also scrutinized in this study. The simulation was then modified based on the results from the field tests. Dynamic parameters of bridges are identified and compared with those from theoretical simulation. The efficiency is also verified to be better for an isolated bridge.

  8. Aerodynamic stability of cable-supported bridges using CFRP cables

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xin-jun; YING Lei-dong

    2007-01-01

    To gain understanding of the applicability of carbon fiber reinforced polymer (CFRP) cable in cable-supported bridges, based on the Runyang Bridge and Jinsha Bridge, a suspension bridge using CFRP cables and a cable-stayed bridge using CFRP stay cables are designed, in which the cable's cross-sectional area is determined by the principle of equivalent axial stiffness.Numerical investigations on the aerodynamic stability of the two bridges are conducted by 3D nonlinear aerodynamic stability analysis. The results showed that as CFRP cables are used in cable-supported bridges, for suspension bridge, its aerodynamic stability is superior to that of the case using steel cables due to the great increase of the torsional frequency; for cable-stayed bridge,its aerodynamic stability is basically the same as that of the case using steel stay cables. Therefore as far as the wind stability is considered, the use of CFRP cables in cable-supported bridges is feasible, and the cable's cross-sectional area should be determined by the principle of equivalent axial stiffness.

  9. A cloud-based information repository for bridge monitoring applications

    Science.gov (United States)

    Jeong, Seongwoon; Zhang, Yilan; Hou, Rui; Lynch, Jerome P.; Sohn, Hoon; Law, Kincho H.

    2016-04-01

    This paper describes an information repository to support bridge monitoring applications on a cloud computing platform. Bridge monitoring, with instrumentation of sensors in particular, collects significant amount of data. In addition to sensor data, a wide variety of information such as bridge geometry, analysis model and sensor description need to be stored. Data management plays an important role to facilitate data utilization and data sharing. While bridge information modeling (BrIM) technologies and standards have been proposed and they provide a means to enable integration and facilitate interoperability, current BrIM standards support mostly the information about bridge geometry. In this study, we extend the BrIM schema to include analysis models and sensor information. Specifically, using the OpenBrIM standards as the base, we draw on CSI Bridge, a commercial software widely used for bridge analysis and design, and SensorML, a standard schema for sensor definition, to define the data entities necessary for bridge monitoring applications. NoSQL database systems are employed for data repository. Cloud service infrastructure is deployed to enhance scalability, flexibility and accessibility of the data management system. The data model and systems are tested using the bridge model and the sensor data collected at the Telegraph Road Bridge, Monroe, Michigan.

  10. Disulfide Bridges: Bringing Together Frustrated Structure in a Bioactive Peptide.

    Science.gov (United States)

    Zhang, Yi; Schulten, Klaus; Gruebele, Martin; Bansal, Paramjit S; Wilson, David; Daly, Norelle L

    2016-04-26

    Disulfide bridges are commonly found covalent bonds that are usually believed to maintain structural stability of proteins. Here, we investigate the influence of disulfide bridges on protein dynamics through molecular dynamics simulations on the cysteine-rich trypsin inhibitor MCoTI-II with three disulfide bridges. Correlation analysis of the reduced cyclic peptide shows that two of the three disulfide distances (Cys(11)-Cys(23) and Cys(17)-Cys(29)) are anticorrelated within ∼1 μs of bridge formation or dissolution: when the peptide is in nativelike structures and one of the distances shortens to allow bond formation, the other tends to lengthen. Simulations over longer timescales, when the denatured state is less structured, do not show the anticorrelation. We propose that the native state contains structural elements that frustrate one another's folding, and that the two bridges are critical for snapping the frustrated native structure into place. In contrast, the Cys(4)-Cys(21) bridge is predicted to form together with either of the other two bridges. Indeed, experimental chromatography and nuclear magnetic resonance data show that an engineered peptide with the Cys(4)-Cys(21) bridge deleted can still fold into its near-native structure even in its noncyclic form, confirming the lesser role of the Cys(4)-Cys(21) bridge. The results highlight the importance of disulfide bridges in a small bioactive peptide to bring together frustrated structure in addition to maintaining protein structural stability. PMID:27119635

  11. Construction and control technology of the main bridge superstructure of Sutong Bridge

    Institute of Scientific and Technical Information of China (English)

    Zhang Hong; Luo Chenbin; Zhang Yongtao; You Xinpeng

    2009-01-01

    The Sutong Yangtze River Bridge (short as Sutong Bridge) is now the largest span cable-stayed bridge in the world. The construction of the superstructure of the middle bridge covered several stages including erection of the big block girders for the side span, assistant span and tower area, erection of standard girders and closure of the middle span. The big block girders were hoisted by a floating crane, and the standard girders were hoisted by a double crane system on the deck. The pushing assistant method was adopted for the middle span closure construction. Furthermore, key technologies and innovative methods used in the processes of girder erection and cable assemblage in all stages were expatiated systematically. An all-stage self- adaptive geometry control method was used in the construction process. By accurately controlling the unstressed dimensions and shape of all structural components in each step, and realization that the control system and the controlled system adapt to each other, the goal was to make control of the final line shape and inner force of the bridge structure achievable. Two solutions, including GPS based and total station based dynamic geometry monitoring systems, were used to resolve the measure problem under the wide-range of wind-induced vibrations in the long cantilever state. Finally, research on the wind-induced vibration of the superstructure during the construction period was executed. Buffeting response analysis to the longest single and double cantilever states were carried out. The analysis and evaluation of wind resistance safety of the main girders under the longest single cantilever state was made, and corresponding wind resistance measures were suggested. The as-built geometric error and cable force error were controlled in a required design range, and this whole technological achievement can be a benchmark for construction of other large span cable-stayed bridges in the future.

  12. Dynamics of fecal indicator bacteria, bacterial pathogen genes, and organic wastewater contaminants in the Little Calumet River: Portage Burns Waterway, Indiana

    Science.gov (United States)

    Haack, Sheridan K.; Duris, Joseph W.

    2013-01-01

    Little information exists on the co-occurrence of fecal indicator bacteria (FIB), bacterial pathogens, and organic wastewater-associated chemicals (OWCs) within Great Lakes tributaries. Fifteen watershed sites and one beach site adjacent to the Little Calumet River–Portage Burns Waterway (LCRPBW) on Lake Michigan were tested on four dates for pH, dissolved oxygen, specific conductance, chloride, color, ammonia- and nitrate-nitrogen, soluble phosphorus, sulfate, turbidity, and atrazine; for concentrations of FIB; and for genes indicating the presence of human-pathogenic enterococci (ENT) and of Shiga-toxin producing Escherichia coli (EC) from various animal sources. Nineteen samples were also tested for 60 OWCs. Half of the watershed samples met EC recreational water quality standards; none met ENT standards. Human-wastewater-associated OWC detections were correlated with human-influence indicators such as population/km2, chloride concentrations, and the presence of WWTP effluents, but EC and ENT concentrations were not. Bacterial pathogen genes indicated rural human and several potential animal sources. OWCs of human or ecosystem health concern (musk fragrances AHTN and HHCB, alkylphenols, carbamazepine) and 3 bacterial pathogen genes were detected at the mouth of the LCRPBW, but no such OWCs and only 1 pathogen gene were detected at the beach. The LCRPBW has significant potential to deliver FIB, potential bacterial pathogens, and OWCs of human or ecosystem health concern to the nearshore of Lake Michigan, under conditions enhancing nearshore transport of the river plume. Nearshore mixing of lake and river water, and the lack of relationship between OWCs and FIB or pathogen genes, pose numerous challenges for watershed and nearshore assessment and remediation.

  13. Investigation of Aerodynamic Interference of Double Deck Bridges

    Energy Technology Data Exchange (ETDEWEB)

    Sitek, M. A. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division. Transportation Research and Analysis Computing Center (TRACC); Bojanowski, C. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division. Transportation Research and Analysis Computing Center (TRACC); Lottes, S. A. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division. Transportation Research and Analysis Computing Center (TRACC)

    2016-05-01

    Construction of a twin bridge can be a cost effective and minimally disruptive way to increase capacity when an existing bridge is not near the end of its service life. With ever growing vehicular traffic, when demand approaches the capacity of many existing roads and bridges. Remodeling a structure with an insufficient number of lanes can be a good solution in case of smaller and less busy bridges. Closing down or reducing traffic on crossings of greater importance for the construction period, however, can result in major delays and revenue loss for commerce and transportation as well as increasing the traffic load on alternate route bridges. Multiple-deck bridges may be the answer to this issue. A parallel deck can be built next to the existing one, without reducing the flow. Additionally, a new bridge can be designed as a twin or multi-deck structure. Several such structures have been built throughout the United States, among them: - The New NY Bridge Project - the Tappan Zee Hudson River Crossing, - SR-182 Columbia River Bridge, - The Thaddeus Kosciusko Bridge (I-87), - The Allegheny River Bridge, Pennsylvania, which carries I76, - Fred Hartman Bridge, TX, see Figure 1.2. With a growing number of double deck bridges, additional, more detailed, studies on the interaction of such bridge pairs in windy conditions appears appropriate. Aerodynamic interference effects should be examined to assure the aerodynamic stability of both bridges. There are many studies on aerodynamic response of single deck bridges, but the literature on double-deck structures is not extensive. The experimental results from wind tunnels are still limited in number, as a parametric study is required, they can be very time consuming. Literature review shows that some investigation of the effects of gap-width and angle of wind incidence has been done. Most of the CFD computational studies that have been done were limited to 2D simulations. Therefore, it is desirable to investigate twin decks

  14. Structural safety monitoring for Nanjing Yangtze River Bridge

    Institute of Scientific and Technical Information of China (English)

    黄方林; 何旭辉; 陈政清; 曾储惠

    2004-01-01

    In order to evaluate objectively and accurately the integrity, safety and operating conditions in real time for the Nanjing Yangtze River Bridge, a large structural safety monitoring system was described. The monitoring system is composed of three parts: sensor system, signal sampling and processing system, and safety monitoring and assessment system. Combining theoretical analysis with measured data analysis, main monitoring contents and layout of measuring points were determined. The vibration response monitoring was significantly investigated. The main contents of safety monitoring on vibration response monitoring are vibration of the main body of the Nanjing Yangtze river bridge, collision avoidance of the bridge piers, vibration of girders on high piers for the bridge approach and earthquake. As a field laboratory, the safety monitorying system also provides information to investigate the unknown and indeterminate problems on bridge structures and specific environment around bridges.

  15. Development of a nondestructive evaluation method for FRP bridge decks

    Science.gov (United States)

    Brown, Jeff; Fox, Terra

    2010-05-01

    Open steel grids are typically used on bridges to minimize the weight of the bridge deck and wearing surface. These grids, however, require frequent maintenance and exhibit other durability concerns related to fatigue cracking and corrosion. Bridge decks constructed from composite materials, such as a Fiber-reinforced Polymer (FRP), are strong and lightweight; they also offer improved rideability, reduced noise levels, less maintenance, and are relatively easy to install compared to steel grids. This research is aimed at developing an inspection protocol for FRP bridge decks using Infrared thermography. The finite element method was used to simulate the heat transfer process and determine optimal heating and data acquisition parameters that will be used to inspect FRP bridge decks in the field. It was demonstrated that thermal imaging could successfully identify features of the FRP bridge deck to depths of 1.7 cm using a phase analysis process.

  16. Detection of Subsurface Defects in Concrete Bridge Deck Joints

    Directory of Open Access Journals (Sweden)

    Wonchang Choi

    2011-01-01

    Full Text Available Problem statement: The integrity of deck joints in highway bridges plays a major role to determine overall performance of bridge system. As the bridge maintenance program, the defects in deck joints have historically been detected by conventional non-destructive testing and evaluation methods such as visual inspection, chain-dragging and by the detecting sounds under the traffic. Future bridge maintenance challenges will demand the development of techniques and procedures to detect and monitor such defects before they become apparent. Approach: Two non-destructive methods; namely Ground Penetration Radar (GPR and Seismic Properties Analyzer (SPA were employed to assess the integrity of deck joins installed in North Carolina bridges. Results: The results obtained with the GPR and SPA allows to quantify the subsurface defects in bridge deck joints. Conclusion: The practical application and limitations of each method are discussed in this study.

  17. Dynamic Vehicle Impact for Safety Assessment of Bridges

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Nielsen, Søren R. K.; Enevoldsen, I.

    In this paper the dynamic amplification of vehicle load at minor highway bridges is considered for safety assessment of the load carrying capacity of bridges. The considered case is the most critical for bridges, i.e. the simultaneous passage of two heavy trucks. A short description...... of the numerical modal parameters of the bridge are known, Only irregularities from imperfect expansion joints have been modelled as bumps at the entrance to the bridge. The results are obtained from a simulation study for different passage situations of the two heavy vehicles. Further, consequences for the safety...... assessment of the bridge are outlined. The results actually obtained show that the dynamic amplification factors used in Danish ans several other national regulations are too conservative....

  18. Wind Tunnel Experiments with Active Control of Bridge Section Model

    DEFF Research Database (Denmark)

    Hansen, Henriette I.; Thoft-Christensen, Palle

    This paper describes results of wind tunnel experiments with a bridge section model where movable flaps are integrated in the bridge girder so each flap is the streamlined part of the edge of the girder. This active control flap system is patented by COWIconsult and may be used to increase the...... flutter wind velocity for future ultra-long span suspension bridges. The purpose of the wind tunnel experiments is to investigate the principle to use this active flap control system. The bridge section model used in the experiments is therefore not a model of a specific bridge but it is realistic...... compared with a real bridge. Five flap configurations are investigated during the wind tunnel experiments and depending on the actual flap configuration it is possible to decrease or increase the flutter wind velocity for the model....

  19. Salt bridge as a gatekeeper against partial unfolding.

    Science.gov (United States)

    Hinzman, Mark W; Essex, Morgan E; Park, Chiwook

    2016-05-01

    Salt bridges are frequently observed in protein structures. Because the energetic contribution of salt bridges is strongly dependent on the environmental context, salt bridges are believed to contribute to the structural specificity rather than the stability. To test the role of salt bridges in enhancing structural specificity, we investigated the contribution of a salt bridge to the energetics of native-state partial unfolding in a cysteine-free version of Escherichia coli ribonuclease H (RNase H*). Thermolysin cleaves a protruding loop of RNase H(*) through transient partial unfolding under native conditions. Lys86 and Asp108 in RNase H(*) form a partially buried salt bridge that tethers the protruding loop. Investigation of the global stability of K86Q/D108N RNase H(*) showed that the salt bridge does not significantly contribute to the global stability. However, K86Q/D108N RNase H(*) is greatly more susceptible to proteolysis by thermolysin than wild-type RNase H(*) is. The free energy for partial unfolding determined by native-state proteolysis indicates that the salt bridge significantly increases the energy for partial unfolding by destabilizing the partially unfolded form. Double mutant cycles with single and double mutations of the salt bridge suggest that the partially unfolded form is destabilized due to a significant decrease in the interaction energy between Lys86 and Asp108 upon partial unfolding. This study demonstrates that, even in the case that a salt bridge does not contribute to the global stability, the salt bridge may function as a gatekeeper against partial unfolding that disturbs the optimal geometry of the salt bridge. PMID:26916981

  20. Abutments influence in the dynamic response of bridges

    OpenAIRE

    Martínez Cutillas, Antonio; Gómez Lera, Sagrario; Alarcón Álvarez, Enrique

    1996-01-01

    A simplified analytical model of a short span bridge is proposed. The inertial interaction effects of pier foundations and abutments has been included in order to evaluate the response sensitivities to different soil-structure interaction variables. The modification of natural frequency and damping properties is shown for typical short span bridges of the integral deck-abutment type for longitudinal vibrations or general bridges for the transverse ones.

  1. Experiences with a two terminal-pair digital impedance bridge

    OpenAIRE

    Callegaro, Luca; D'Elia, Vincenzo; Kampik, Marian; Kim, Dan Bee; Ortolano, Massimo; Pourdanesh, Faranak

    2014-01-01

    This paper describes the realization of a two terminal-pair digital impedance bridge and the test measurements performed with it. The bridge, with a very simple architecture, is based on a commercial two-channel digital signal synthesizer and a synchronous detector. The bridge can perform comparisons between impedances having arbitrary phase and magnitude ratio: its balance is achieved automatically in less than a minute. $R$-$C$ comparisons with calibrated standards, at kHz frequency and 100...

  2. Force generated by actomyosin contraction builds bridges between adhesive contacts

    OpenAIRE

    Rossier, Olivier M.; Gauthier, Nils; Biais, Nicolas; Vonnegut, Wynn; Fardin, Marc-Antoine; Avigan, Philip; Heller, Evan R; Mathur, Anurag; Ghassemi, Saba; Koeckert, Michael S; Hone, James C.; Sheetz, Michael P.

    2010-01-01

    Extracellular matrices in vivo are heterogeneous structures containing gaps that cells bridge with an actomyosin network. To understand the basis of bridging, we plated cells on surfaces patterned with fibronectin (FN)-coated stripes separated by non-adhesive regions. Bridges developed large tensions where concave cell edges were anchored to FN by adhesion sites. Actomyosin complexes assembled near those sites (both actin and myosin filaments) and moved towards the centre of the non-adhesive ...

  3. Jointless and Smoother Bridges: Behavior and Design of Piles

    OpenAIRE

    Frosch, Robert J; Chovichien, Voraniti; Durbin, Katrinna; Fedroff, David

    2006-01-01

    Integral abutment bridges have been used in the United States for decades. By eliminating expensive expansion joints, the piles supporting the end bent accommodate the total thermal movement of the bridge. Currently, integral bridges are designed based upon experience, and a rational design specification has not been developed. Furthermore, the interaction of the abutment, pile, and soil remains uncertain. A better understanding regarding the behavior of this system is needed. The objective o...

  4. The number of capillary bridges in a wet granular medium

    OpenAIRE

    Geromichalos, Dimitrios; Kohonen, Mika M.; Scheel, Mario; Herminghaus, Stephan

    2003-01-01

    We observed the appearance of capillary bridges in a granular medium consisting of glass beads after adding small amounts of liquid. We found the initial bridge formation depending on the bead roughness. Furthermore we obtained a statistics for the average number of bridges for randomly packed beads in dependence of the liquid content and were able to find an explanation therefore based on recent models and former experimental data.

  5. Electron Transfer rate between a electrode and a bridged redox

    OpenAIRE

    Cruz, A. V. B.; Mishra, A. K.; Schmickler, W.

    2009-01-01

    We derive an explict bias dependent expression for electron transfer reaction rate from a solvated redox to a electrode through a bridged molecule of arbitrary length. The interaction of the solvated redox with the solvent is modelled as a classical harmonic oscillator bath. The effect of competing process, namely resonance tunneling between redox and bridge and the solvation of the redox is investigated. Plots were produced for the case of 5 atom bridge. Our analysis shows that for certain s...

  6. Commutation Processes in Multiresonant ZVS Bridge Converter

    Directory of Open Access Journals (Sweden)

    Miroslaw Luft

    2008-01-01

    Full Text Available The analysis of the multiresonant ZVS DC/DC bridge converter is presented. The control system of the converter is basedon the method of frequency control at the constant time of transistor turn-off with a phase shift. The operation of the circuit is givenand the operating range of the converter is defined where ZVS switching operation is assured. Control characteristics are given andthe converter’s efficiency is defined. The circuit’s operation is analysed on the basis of results of the converter simulation tests using Simplorer programme.

  7. Bridge connection of quantum Hall elementary devices

    CERN Document Server

    Callegaro, Luca

    2013-01-01

    Multiple-series and multiple-parallel connections of quantum Hall elementary devices allow the realization of multiple or fractional values of the quantized Hall resistance, rejecting the effect of contact and wiring resistances. We introduce here the multiple-bridge connection, which maintains the properties of multiple-series and parallel connections and allows more freedom in the choice of the topology of networks composed of quantum Hall elements, and the design of more efficient quantum Hall array resistance standards (and other devices). As an example, a 5-element network is analyzed in detail.

  8. Fatigue Performance of Bridge Deck Pavement Materials

    Institute of Scientific and Technical Information of China (English)

    WU Shaopeng; ZHANG Guang; HAN Jun; LIU Gang; ZHOU Jie

    2009-01-01

    Three beam samplesof bridge deck pavementwere prepared, with gradationtypes of AC-13, and AC-16 and combined AC-13+AC-16. Four-point bending test was adopted to investigate the fatigue performance of these beam samples. The experimental results indicate that the initial bending stiffness is related to the type of beam sample and testing temperature. Fatigue life of these samples decreases as the increase of the controlled strain level. The AC-13 beam sample exhibits better fatigue resistance and bigger limiting bending strain at the given strain level and temperature. Com-pared with single beam sample, the fatigue performance of combining beam sample is relatively poor.

  9. Comparison of Temperature Loadings of Bridge Girders

    Directory of Open Access Journals (Sweden)

    J. Římal

    2008-01-01

    Full Text Available This paper compares the effect of temperature changes on the superstructure of bridges, above all the effect of non-uniform temperature. Loadings according to standards ESN 73 6203, ENV 1991-1-5 and DIN 1072 are compared here. The paper shows a short summary of temperature loading according to each standard and shows the comparison of bending moments arisen from these temperature loadings on superstructure made from continuous girder from a steel-concrete box girder with a composite concrete slab. With respect to a variety of design processes, the comparison is made without any coefficient of loading, combination or material. 

  10. Why the Water Bridge does not collapse

    CERN Document Server

    Aerov, Artem Anatolievich

    2010-01-01

    In 2007 an interesting phenomenon was discovered: a thread of water, the so-called water bridge (WB), can hang between two glass beakers filled with deionized water if voltage is applied to them. We analyze the available explanations of the WB stability and propose a completely different one: the force that supports the WB is the surface tension of water and the role of electric field is not to allow the WB to reduce its surface energy by means of breaking into separate drops.

  11. 控制船机废气排放的绿色水运技术分析%Analysis of green waterway transportation technology to control marine engine emissions

    Institute of Scientific and Technical Information of China (English)

    高炳; 赵自奇

    2014-01-01

    This paper analyzes the atmospheric pollution from the exhaust emission of marine diesel engine in waterway transportation, and introduces the control requirements of the marine engine emissions of the relevant conventions of International Maritime Organization. It discusses the critical industrial issues about the control technology of marine engine emission and green house gas emission, as well as domestic and international regulations and incentives. It also proposes further ideas and measures to improve the control of marine engine emission, which can promote the key technology of energy-saving and emission-reduction in waterway transportation, research and promotion of the advanced and applicable technologies and products, as well as the sustainable development of the green waterway transportation.%文章分析了水路运输船舶柴油机废气排放对大气的污染,介绍了国际海事组织相关公约对船机排放的控制要求,讨论了业界重点关注的船机废气排放控制技术、温室气体排放等热点问题、以及国内外法规与鼓励措施等。文中还提出进一步完善控制船机废气排放的措施和思路,以期推进水路运输节能减排重大关键技术、先进适用技术与产品的研发与推广,促进绿色水运可持续发展。

  12. Structural health monitoring of bridges in the State of Connecticut

    Institute of Scientific and Technical Information of China (English)

    Chengyin Liu; Joshua Olund; Alan Cardini; Paul D'Attilio; Erie Feldblum; John DeWolf

    2008-01-01

    A joint effort between the Connecticut Department of Transportation and the University of Connecticut has been underway for more than 20 years to utilize various structural monitoring approaches to assess different bridges in Connecticut.This has been done to determine the performance of existing bridges,refine techniques needed to evaluate different bridge components,and develop approaches that can be used to provide a continuous status of a bridge's structural integrity,This paper briefly introduces the background of these studies,with emphasis on recent research and the development of structural health monitoring concepts.This paper presents the results from three different bridge types:a post-tensioned curved concrete box girder bridge,a curved steel box-girder bridge,and a steel multi-girder bridge.The structural health monitoring approaches to be discussed have been successfully tested using field data collected during multi-year monitoring periods,and are based on vibrations,rotations and strains.The goal has been to develop cost-effective strategies to provide critical information needed to manage the State of Connecticut's bridge infrastructure.

  13. Aerodynamic stability of cable-stayed-suspension hybrid bridges

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xin-jun; SUN Bing-nan

    2005-01-01

    Three-dimensional nonlinear aerodynamic stability analysis was applied to study the aerodynamic stability of a cable-stayed-suspension (CSS) hybrid bridge with main span of 1400 meters, and the effects of some design parameters (such as the cable sag, length of suspension portion, cable plane arrangement, subsidiary piers in side spans, the deck form, etc.) on the aerodynamic stability of the bridge are analytically investigated. The key design parameters, which significantly influence the aerodynamic stability of CSS hybrid bridges, are pointed out, and based on the wind stability the favorable structural system of CSS hybrid bridges is discussed.

  14. Assessment of concrete bridge decks with alkali silica reactions

    DEFF Research Database (Denmark)

    Eriksen, Kirsten; Jansson, Jacob; Geiker, Mette Rica

    2008-01-01

    Based on investigations of concrete from an approximately 40 years old bridge a procedure to support the management of maintenance and repair of alkali silica damaged bridges is proposed. Combined petrography and accelerated expansion testing were undertaken on cores from the Bridge at Skovdiget......, Bagsværd, Denmark to provide information on the damage condition as well as the residual reactivity of the concrete. The Danish Road Directory’s guidelines for inspection and assessment of alkali silica damaged bridges will be briefly presented, and proposed modifications will be describe...

  15. Modulating unimolecular charge transfer by exciting bridge vibrations.

    Science.gov (United States)

    Lin, Zhiwei; Lawrence, Candace M; Xiao, Dequan; Kireev, Victor V; Skourtis, Spiros S; Sessler, Jonathan L; Beratan, David N; Rubtsov, Igor V

    2009-12-23

    Ultrafast UV-vibrational spectroscopy was used to investigate how vibrational excitation of the bridge changes photoinduced electron transfer between donor (dimethylaniline) and acceptor (anthracene) moieties bridged by a guanosine-cytidine base pair (GC). The charge-separated (CS) state yield is found to be lowered by high-frequency bridge mode excitation. The effect is linked to a dynamic modulation of the donor-acceptor coupling interaction by weakening of H-bonding and/or by disruption of the bridging base-pair planarity.

  16. Method of tuning a strain gauge full bridge

    International Nuclear Information System (INIS)

    In the strain gauge full bridge consisting of four narrow bridge branches acting as strain gauges a change in cross section of the broadened conductor area between the strain gauges is made. This is achieved by means of a focused laser beam, preferably by using it to cut a gap in the conductor area. This allows the bridge to be tuned extremely finely because the development of the gap can be controlled as a function of the bridge output signal during the cutting procedure. Hence, small changes in resistivity of the broadened conductor area can be achieved in this way. (DG)

  17. Theoretical mechanics: Crowd synchrony on the Millennium Bridge

    Science.gov (United States)

    Strogatz, Steven H.; Abrams, Daniel M.; McRobie, Allan; Eckhardt, Bruno; Ott, Edward

    2005-11-01

    Soon after the crowd streamed on to London's Millennium Bridge on the day it opened, the bridge started to sway from side to side: many pedestrians fell spontaneously into step with the bridge's vibrations, inadvertently amplifying them. Here we model this unexpected and now notorious phenomenon - which was not due to the bridge's innovative design as was first thought - by adapting ideas originally developed to describe the collective synchronization of biological oscillators such as neurons and fireflies. Our approach should help engineers to estimate the damping needed to stabilize other exceptionally crowded footbridges against synchronous lateral excitation by pedestrians.

  18. Geodetic Measurement of Longitudinal Displacements of the Railway Bridge

    Directory of Open Access Journals (Sweden)

    Jaroslav Braun

    2014-06-01

    Full Text Available The paper deals with geodetic measurements of mutual longitudinal displacements ofconstruction of the railway bridge and rails on the bridge in Klášterec nad Oh í.Construction of the bridge is made of steel with a concrete deck, which carries the stonesuperstructure and rails. The bridge is about 100 meters long and expected deformationsare in millimetres. The method of geodetic network with the expected standard deviationsof coordinates about 0.2 mm was chosen. The deformation of the structure was determinedto be 4 mm, the deformation of the rails was determined to be 1 mm, both as a result ofepoch comparison.

  19. Running Safety of Trains under Vessel-Bridge Collision

    Directory of Open Access Journals (Sweden)

    Yongle Li

    2015-01-01

    Full Text Available To optimize the sensor placement of the health monitoring system, the dynamic behavior of the train-bridge system subjected to vessel-collision should be studied in detail firstly. This study thus focuses on the characteristics of a train-bridge system under vessel-bridge collision. The process of the vessel-bridge collision is simulated numerically with a reliable finite element model (FEM. The dynamic responses of a single car and a train crossing a cable-stayed bridge are calculated. It is shown that the collision causes significant increase of the train’s lateral acceleration, lateral wheelset force, wheel unloading rate, and derailment coefficient. The effect of the collision on the train’s vertical acceleration is much smaller. In addition, parametric studies with various train’s positions, ship tonnage, and train speed are performed. If the train is closer to the vessel-bridge collision position or the ship tonnage is larger, the train will be more dangerous. There is a relatively high probability of running danger at a low speed, resulting from longer stay of the train on the bridge. The train’s position, the ship tonnage, and the train speed must be considered when determining the most adverse conditions for the trains running on bridges under vessel-bridge collision.

  20. Measurement evaluation and FEM simulation of bridge dynamics

    OpenAIRE

    Andersson, Andreas; Malm, Richard

    2004-01-01

    The aim of this thesis is to analyse the effects of train induced vibrations in a steel Langer beam bridge. A case study of a bridge over the river Ljungan in Ånge has been made by analysing measurements and comparing the results with a finite element model in ABAQUS. The critical details of the bridge are the hangers that are connected to the arches and the main beams. A stabilising system has been made in order to reduce the vibrations which would lead to increased life length of the bridge...

  1. Dialkylenecarbonate-Bridged Polysilsesquioxanes. Hybrid Organic Sol-Gels with a Thermally Labile Bridging Group

    Energy Technology Data Exchange (ETDEWEB)

    Loy, D.A.; Beach, J.V.; Baugher, B.M.; Assink, R.A.; Shea, K.J.; Tran, J.; Small, J.H.

    1999-04-21

    In this paper, we introduce a new approach for altering the properties of bridged polysilsesquioxane xerogels using post-processing modification of the polymeric network. The bridging organic group contains latent functionalities that can be liberated thermally, photochemically, or by chemical means after the gel has been processed to a xerogel. These modifications can produce changes in density, volubility, porosity, and or chemical properties of the material. Since every monomer possesses two latent functional groups, the technique allows for the introduction of high levels of functionality in hybrid organic-inorganic materials. Dialkylenecarbonate-bridged polysilsesquioxane gels were prepared by the sol-gel polymerization of bis(triethoxysilylpropyl)carbonate (1) and bis(triethoxysilylisobutyl)-carbonate (2). Thermal treatment of the resulting non-porous xerogels and aerogels at 300-350 C resulted in quantitative decarboxylation of the dialkylenecarbonate bridging groups to give new hydroxyalkyl and olefinic substituted polysilsesquioxane monolithic xerogels and aerogels that can not be directly prepared through direct sol-gel polymerization of organotrialkoxysilanes.

  2. Vibration analysis of the Second Saikai Bridge—a concrete filled tubular (CFT) arch bridge

    Science.gov (United States)

    Yoshimura, Mistuhiro; Wu, Qingxiong; Takahashi, Kazuo; Nakamura, Shozo; Furukawa, Kazuyoshi

    2006-02-01

    Concrete-filled steel tubular (CFT) arch bridges have been rapidly developing in China since 1990. Research has focused on the static behavior, thermal stress and erection technique, however, and there has been very little research of natural vibrations and dynamic responses of these bridges. Japan's first CFT arch bridge in highway bridges, the Second Saikai Bridge, is now under construction in Nagasaki Prefecture. Furthermore, this bridge has a pedestrian bridge that is suspended under the girder, which is rare. Therefore, the natural vibration properties are examined, and the influence of pedestrian bridge structure on the natural vibration of main bridge is discussed first. Response analysis under a moving vehicle and pedestrian is carried out, and the response characteristics and response level are clarified. The natural vibrations and responses are compared to those of CFT arch bridges that have been constructed in China. Results show the fine performance of both main bridge and pedestrian bridge of the Second Saikai Bridge.

  3. 贵港西江黄金水道物流信息服务平台需求分析%Study on Demand in Constructing Logistics Information Service Platform of Guigang Xijiang Golden Waterway

    Institute of Scientific and Technical Information of China (English)

    张宏元

    2012-01-01

    Through a field survey in Guigang, we have analyzed comprehensively the demand for information, function, performance and system of the construction of logistics information service platform for the Xijiang golden waterway.%根据对贵港的实地调研,全面分析了贵港西江黄金水道物流信息服务平台建设的信息需求、功能需求、性能需求和系统需求,以期为平台建设提供一定的参考.

  4. Ældre betonbroers bæreevne (Load bearing capacity of old concrete bridges)

    DEFF Research Database (Denmark)

    Nielsen, Anders

    1999-01-01

    Two old bridges have been analysed in connection with their demolition. The first one is a pedestrian bridge, the Gefion bridge, from 1894. This is the first bridge of reinforced concrete in Denmark. Here the creep in the concrete severely have changed the way in which the load on the bridge was ...

  5. Building Better Bridges: An Evaluation of The Bridge to the Ph.D. Program

    Science.gov (United States)

    Ellyn Sanderson, Robyn; Lobel, Caroline; Agueros, Marcel A.; Anderson, Vanessa; Ash, Summer; Purdie-Vaughns, Valerie; Romero-Canyas, Rainer; Walker, Erica

    2016-01-01

    Columbia University's Bridge to the Ph.D. in the Natural Sciences Program is increasing the number of underrepresented scholars entering graduate programs and equipping them to succeed in these programs. In a given year, three to five Bridge participants are hired as full-time Columbia University research assistants for up to two years. Now in its seventh year, the Program supports seven participants, and its alumni (including five astronomers) have gone on to Ph.D. programs across the country. Although to date fewer than 40 people have participated in the Program, a number too small for an exclusively statistical evaluation of its effectiveness, we are collecting invaluable longitudinal data on the career progressions of underrepresented aspiring scientists across the natural sciences. At least a dozen Bridge alumni will earn their Ph.D. in the next two-three years, and we will then learn much more about the impact that the Bridge Program has had on our participants' trajectories. Among other things, we hope to use these data to determine the Program's effectiveness in developing feelings of self-efficacy and participants' confidence in their ability to succeed in doctoral programs, to measure the rate at which Bridge alumni successfully complete doctoral programs relative to their peers, and to identify the aspects of the Program that participants find most helpful to their progress at different stages of their paths to and through doctoral programs. Here we describe the data we have already obtained as part of our on-going study, and preliminary results from our analysis.

  6. The iron abundance of the Magellanic Bridge

    CERN Document Server

    Dufton, P L; Thompson, H M A; Street, R A

    2008-01-01

    High-resolution HST ultra-violet spectra for five B-type stars in the Magellanic Bridge and in the Large and Small Magellanic Clouds have been analysed to estimate their iron abundances. Those for the Clouds are lower than estimates obtained from late-type stars or the optical lines in B-type stars by approximately 0.5 dex. This may be due to systematic errors possibly arising from non-LTE effects or from errors in the atomic data as similar low Fe abundances having previously been reported from the analysis of the ultra-violet spectra of Galactic early-type stars. The iron abundance estimates for all three Bridge targets appear to be significantly lower than those found for the SMC and LMC by approximately -0.5 dex and -0.8 dex respectively and these differential results should not be affected by any systematic errors present in the absolute abundance estimates. These differential iron abundance estimates are consistent with the underabundances for C, N, O, Mg and Si of approximately -1.1 dex relative to our...

  7. A review of bridge scour monitoring techniques

    Institute of Scientific and Technical Information of China (English)

    L.J. Prendergast; K. Gavin

    2014-01-01

    The high profile failure of the Malahide Viaduct in Dublin, Ireland, which is a part of the EU TEN-T network of critical transport links, was caused by foundation scour. Scour is a common soil-structure interaction problem. In light of current changes in climate, increasing frequency of flooding, coupled with the increasing magnitude of these flood events, will lead to a higher risk of bridge failure. Moni-toring scour is of paramount importance to ensure the continued safe operation of the aging bridge asset network. Most monitoring regimes are based on expensive underwater instrumentation that can often be subjected to damage during times of flooding, when scour risk is at its highest. This paper presents a critical review of existing scour monitoring equipments and methodologies with a particular focus on those using the dynamic response of the structure to indicate the existence and severity of the scour phenomenon affecting the structure. A sensitivity study on a recently developed monitoring method is also undertaken.

  8. Bridging physics and biology teaching through modeling

    Science.gov (United States)

    Hoskinson, Anne-Marie; Couch, Brian A.; Zwickl, Benjamin M.; Hinko, Kathleen A.; Caballero, Marcos D.

    2014-05-01

    As the frontiers of biology become increasingly interdisciplinary, the physics education community has engaged in ongoing efforts to make physics classes more relevant to life science majors. These efforts are complicated by the many apparent differences between these fields, including the types of systems that each studies, the behavior of those systems, the kinds of measurements that each makes, and the role of mathematics in each field. Nonetheless, physics and biology are both sciences that rely on observations and measurements to construct models of the natural world. In this article, we propose that efforts to bridge the teaching of these two disciplines must emphasize shared scientific practices, particularly scientific modeling. We define modeling using language common to both disciplines and highlight how an understanding of the modeling process can help reconcile apparent differences between the teaching of physics and biology. We elaborate on how models can be used for explanatory, predictive, and functional purposes and present common models from each discipline demonstrating key modeling principles. By framing interdisciplinary teaching in the context of modeling, we aim to bridge physics and biology teaching and to equip students with modeling competencies applicable in any scientific discipline.

  9. Photomagnetism in cyano-bridged bimetal assemblies.

    Science.gov (United States)

    Ohkoshi, Shin-ichi; Tokoro, Hiroko

    2012-10-16

    The study of photoinduced phase-transition materials has implications for the fields of inorganic chemistry, solid-state chemistry, and materials science. Cyano-bridged bimetal assemblies are promising photomagnetic materials. Because cyano-bridged bimetal assemblies possess various absorption bands in the visible light region, their electronic and spin states can be controlled by visible light irradiation. Moreover, the selection of magnetic metal ions and organic ligands provide a way of controlling spin-spin interactions through a cyano bridge. In this Account, we describe cyano-bridged bimetal assemblies developed in our laboratory. Cu(II)(2)[Mo(IV)(CN)(8)]·8H(2)O (CuMo), Rb(I)Mn(II)[Fe(III)(CN)(6)] (RbMnFe), and Co(II)(3)[W(V)(CN)(8)](2)·(pyrimidine)(4)·6H(2)O (CoW) induce photomagnetism via photoinduced metal-to-metal charge transfers (MM'CT), while Fe(II)(2)[Nb(IV)(CN)(8)]·(4-pyridinealdoxime)(8)·2H(2)O (FeNb) exhibits a photoinduced magnetization via a photoinduced spin crossover. Irradiation with 473 nm light causes the CuMo system to exhibit a spontaneous magnetization with a Curie temperature (T(C)) of 25 K, but irradiation with 532, 785, and 840 nm light reduces the magnetization. In this reversible photomagnetic process, excitation of the MM'CT from Mo(IV) to Cu(II) produces a ferromagnetic mixed-valence isomer of Cu(I)Cu(II)[Mo(V)(CN)(8)]·8H(2)O (CuMo'). CuMo' returns to CuMo upon irradiation in the reverse-M'MCT band. RbMnFe shows a charge transfer (CT)-induced phase transition from the Mn(II)-Fe(III) phase to the Mn(III)-Fe(II) phase. Irradiation with 532 nm light converts the Mn(III)-Fe(II) phase into the Mn(II)-Fe(III) phase, and we observe photodemagnetization. In contrast, irradiation of the Mn(II)-Fe(III) phase with 410 nm light causes the reverse phase transition. A CT-induced Jahn-Teller distortion is responsible for this visible light-induced reversible photomagnetic effect. In the CoW system, a CT-induced spin transition causes the

  10. Critical traffic loading for the design of prestressed concrete bridge

    International Nuclear Information System (INIS)

    A study has been carried out to determine critical traffic loadings for the design of bridge superstructures. The prestressed concrete girder bridge already constructed in Lahore is selected for the analysis as an example. Standard traffic loadings according to AASHTO (American Association of State Highway and Transportation Officials) and Pakistan Highway Standards are used for this purpose. These include (1) HL-93 Truck, (2) Lane and (3) Tandem Loadings in addition to (4) Military tank loading, (5) Class-A, (6) Class-B and (7) Class-AA loading, (8) NLC (National Logistic Cell) and (9) Volvo truck loadings. Bridge superstructure including transom beam is analyzed Using ASD and LRFD (Load and Resistance Factor Design) provisions of AASHTO specifications. For the analysis, two longer and shorter spans are selected. This includes the analysis of bridge deck; interior and exterior girder; a typical transom beam and a pier. Dead and live loading determination is carried out using both computer aided and manual calculations. Evaluation of traffic loadings is done for all the bridge components to find out the critical loading. HL-93 loading comes out to be the most critical loading and where this loading is not critical in case of bridge decks; a factor of 1.15 is introduced to make it equivalent with HL-93 -Ioading. SAP-2000 (Structural Engineering Services of Pakistan) and MS-Excel is employed for analysis of bridge superstructure subjected to this loading. Internal forces are obtained for the structural elements of the bridge for all traffic loadings mentioned. It is concluded that HL-93 loading can be used for the design of prestressed concrete girder bridge. Bridge design authorities like NHA (National Highway Authority) and different cities development authorities are using different standard traffic loadings. A number of suggestions are made from the results of the research work related to traffic loadings and method of design. These recommendations may be

  11. SNP diversity of Enterococcus faecalis and Enterococcus faecium in a South East Queensland waterway, Australia, and associated antibiotic resistance gene profiles

    Directory of Open Access Journals (Sweden)

    Huygens Flavia

    2011-09-01

    E. faecium genotypes is highly diverse in the Coomera River. The SNP genotyping method is rapid and robust and can be applied to study the diversity of E. faecalis and E. faecium in waterways. It can also be used to test for human-related and human-specific enterococci in water. The resolving power can be increased by including antibiotic-resistant profiles which can be used as a possible source tracking tool. This warrants further investigation.

  12. Study of behavior of hanging bridges type Pony

    OpenAIRE

    Caori Patricia Takeuchi Tam; Beatriz Elena León; Mario Alberto González

    2010-01-01

    In the country there is a great quantity of hanging bridges type pony. This article presents the methodology and the results obtained in a study of the behavior of this type of bridges for the construction and the service loads. Besides, the behavior of the lateral stability of these models.

  13. Efficient photoinduced energy transfer mediated by aromatic homoconjugated bridges

    NARCIS (Netherlands)

    J. Osío Barcina; N. Herrero-García; F. Cucinotta; L. De Cola; P. Contreras-Carballada; R.M. Williams

    2010-01-01

    A new donor bridge acceptor (D-B-A) dyad consisting of ruthenium(II) and iridium(III) species separated by an homoconjugated bridge derived from 7,7-diphenylnorbornane [Ir-Nor-Ru](3+) has been synthesised. The photophysical and electrochemical properties of the heterodinuclear complex have been comp

  14. Fatigue assessment for deck plates in orthotropic bridge decks

    NARCIS (Netherlands)

    Maljaars, J.; Dooren, F. van; Kolstein, H.

    2012-01-01

    Since the 1960s, orthotropic deck plates of highway bridges have been built with large coldformed trapezoidal stiffeners supporting a deck plate with a thickness of approx. 12 mm. The maximum cross-beam spacing is approx. 4 m. A number of these bridge decks in The Netherlands suffer from fatigue cra

  15. Operational modal analysis of road-rail bridge

    Directory of Open Access Journals (Sweden)

    Cardoso M.

    2015-01-01

    Full Text Available In this paper, we describe an Operational Modal Analysis (OMA of the Bridge over the Tocantins River, a composite road-rail bridge located in the city of Marabá, state of Pará, northern Brazil. The bridge is part of the Carajás Railway, which is used by VALE Company to transport iron ore from “Serra dos Carajás”, the largest mineral reserve of the planet. The bridge has a length of 2310m, being the second longest road-rail bridge in Brazil. The study focused on the bridge central span (with 77 m of length and two adjacent spans (with 44 m of length. We employed Piezo-electric accelerometers to measure the dynamic response of the bridge under ambient excitation, which consisted of the passage of loaded and unloaded trains, road traffic, wind and river current. For modal identification, to avoid the influence of the train mass over the bridge system, we only considered acceleration signals of road traffic and signals corresponding to intervals after the passage of loaded trains, i.e., the study disregarded the intervals during which the trains were over the monitored spans. We obtained modal parameters through two identification methods: one in the time domain and other in the frequency domain. We also performed a comparative analysis between the experimental modal parameters, and the numerical results obtained with a finite element model provided by a third-part company.

  16. Comparison of Ferry Boat and Highway Bridge Energy Use

    Directory of Open Access Journals (Sweden)

    Wayne D. Cottrell

    2011-01-01

    Full Text Available Passenger ferries serve a variety of transport needs in the U.S., such as providing vital links across bodies of water, and supplementing highway bridges. In some cases in which there is a ferry connection but no bridge, a bridge would be impractical; in other cases, a bridge might be feasible. The paper compares the energy consumption of ferries and motor vehicles on bridges, to determine which link is more fuel efficient. One finding is that limited data are available on ferry boat fuel consumption: despite there being 208 ferry boat operators in the U.S. as of 2008, only eight were providing energy use data to the National Transit Database. Examinations of three of the systems found that the passenger-MPG of the ferries ranged from 2.61 to 14.00 (1.11 to 5.95 km/L, while that of the motor vehicles on adjacent highway bridge connections ranged from 25.34 to 32.45 (10.77 to 13.79 km/L. Data from the eight systems are used to develop a ferry MPG model. The model is used to show that the Ryer Island and Charles Hall Ferries are less fuel efficient than hypothetical bridges in those locations. The fuel efficiencies and consumptions of the ferries would equal those of motor vehicles on the bridges, however, if smaller vessels were used, and if the frequency of service was reduced.

  17. Very High Frequency Half Bridge DC/DC Converter

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    This paper presents the first, off chip, class DE (resonant half bridge) converter working in the Very High Frequency (VHF) range. The benefits of using half bridge circuits both in the inverter and rectifier part of a VHF resonant dc/dc converter are analyzed and design equations for all...

  18. Multidisciplinary health monitoring of a steel bridge deck structure

    NARCIS (Netherlands)

    Pahlavan, L.; Pijpers, R.J.M.; Paulissen, J.H.; Hakkesteegt, H.C.; Jansen, T.H.

    2013-01-01

    Fatigue cracks in orthotropic bridge decks are an important cause for the necessary renovation of existing bridges. Parallel utilization of various technologies based on different physical sensing principles can potentially maximize the efficiency of structural health monitoring (SHM) systems for th

  19. OnWien Bridge Oscillators as Modified Multi-vibrators

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2014-01-01

    A tutorial introduction to electrical oscilla- tors. Investigating Wien bridge oscillators as modified multi-vibrators. Introducing chaotic behavior into a Wien bridge oscillator by means of adding a simple nonlinear cir- cuit as a load of one of the amplifier input terminals...

  20. Assessment of the Reliability Profiles for Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper calculation of reliability profiles is discussed. ULS as well as SLS limit states are formulated. Corrosion due to chloride penetration is the considered deterioration mechanism. Three models for corrosion are formulated. A definition of service lifetime for concrete bridges...... is presented and discussed. The proposed method of calculating reliability profiles is illustrated on an exiting U.K. bridge....

  1. GOOD HEALTH AND THE BRIDGING OF STRUCTURAL HOLES.

    Science.gov (United States)

    Cornwell, Benjamin

    2009-01-01

    Bridges that span structural holes are often explained in terms of the entrepreneurial personalities or rational motivations of brokers, or structural processes that lead to the intersection of social foci. I argue that the existence and use of bridges in interpersonal networks also depends on individuals' health. Poor health may make it more difficult to withstand the pressures and to execute some of the common tasks associated with bridging (e.g., brokerage). I examine this possibility using egocentric network data on over 2,500 older adults drawn from the recent National Social Life, Health, and Aging Project (NSHAP). Multivariate regression analyses show that both cognitive and functional health are significantly positively associated with bridging, net of sociodemographic and life-course controls. The relationship between functional (kinesthetic) health and bridging appears to be partially mediated by network composition, as older adults who have poorer functional health also tend to have networks that are richer in strong ties. Several potential mediation mechanisms are discussed. Cognitive function remains significantly associated with bridging net of network composition, suggesting that the inherent challenges of maintaining bridging positions may be more difficult to cope with for those who have cognitive impairments than for those who have functional impairments such as limited mobility. An alternative explanation is that cognitively impaired individuals have more difficulty recognizing (and thus strategically using) bridges in their networks. Theoretical implications and possibilities for future research are discussed. PMID:20046998

  2. Impact of bridge pier on the stability of ice jam

    Institute of Scientific and Technical Information of China (English)

    王军; 施发义; 陈胖胖

    2015-01-01

    River ice jam is one of the most important issues in rivers in cold regions during winter time. With the extra solid boundary due to the ice cover, the flow condition under ice-covered conditions is completely different from that of a open channel flow. The presence of bridge piers will further change the velocity field around the bridge piers. As a consequence, the formation and the accumulation of ice jams in the vicinity of the bridge pier will be affected. On the other side, the formation of an ice jam around the piers can cause extra turbulence to reduce the stability of a river bridge. The present study focuses on the stress analysis of the ice jam in the vicinity of a bridge pier. By developing a governing equation for describing the equilibrium state of an ice jam, the stability of the ice jam around bridge piers is analyzed and determined. As seen from the field data in literature, the stability estimations of an ice jam around bridge piers determined by the present method agree well with the field observations. Therefore, the proposed approach can be used for the prediction of the formation of ice jams around bridge piers.

  3. Introduction of New Book: Scouring at Bridge Crossings

    Institute of Scientific and Technical Information of China (English)

    Hongwu Zhang

    2005-01-01

    @@ Mr. Kan Yi's book Scouring at Bridge Crossings, based on a large amount of field survey data, field investigation data and laboratory test data, has been published by China Railway Publishing House on August 2004 in Beijing. It is a monographic writing on scouring at bridge crossings.

  4. Building New Bridges: Linking Organization Theory with Other Educational Literatures

    Science.gov (United States)

    Johnson, Bob L., Jr.; Owens, Michael

    2005-01-01

    Purpose: This paper provides an example of how organization theory can be linked with other literatures in a complementary and productive manner. Establishing a bridge between the organization theory and learning environment literatures, the authors seek to provide an example of how such literature-bridging can enrich our understanding of the…

  5. Review on antibacterial characteristics of bridge engineering biomaterials.

    Science.gov (United States)

    Zhao, Qing-Qing; Chen, Meng-Yao; He, Rui-Lin; Zhang, Zhong-Feng; Ashraf, Muhammad Aqeel

    2016-01-01

    This review summarizes the research on timber construction materials used in bridge construction. It focuses on the application of antiseptic treatments and the use of timber engineering materials in decks and bridges. This review also provides an overview on the future research and prospects of engineered timber materials. PMID:26858558

  6. The South Carolina bridge-scour envelope curves

    Science.gov (United States)

    Benedict, Stephen T.; Feaster, Toby D.; Caldwell, Andral

    2016-09-30

    The U.S. Geological Survey, in cooperation with the South Carolina Department of Transportation, conducted a series of three field investigations to evaluate historical, riverine bridge scour in the Piedmont and Coastal Plain regions of South Carolina. These investigations included data collected at 231 riverine bridges, which lead to the development of bridge-scour envelope curves for clear-water and live-bed components of scour. The application and limitations of the South Carolina bridge-scour envelope curves were documented in four reports, each report addressing selected components of bridge scour. The current investigation (2016) synthesizes the findings of these previous reports into a guidance manual providing an integrated procedure for applying the envelope curves. Additionally, the investigation provides limited verification for selected bridge-scour envelope curves by comparing them to field data collected outside of South Carolina from previously published sources. Although the bridge-scour envelope curves have limitations, they are useful supplementary tools for assessing the potential for scour at riverine bridges in South Carolina.

  7. Wind Tunnel Testing of Active Control System for Bridges

    DEFF Research Database (Denmark)

    Hansen, Henriette I.; Thoft-Christensen, Palle

    This paper describes preparation of wind tunnel testing of the principle of using flaps to control the motion of suspension bridges. The experiment will take place at the Instituto Superior Technico Lisbon, Portugal. The bridge section model is constructed of foam with an aluminium frame. The flaps...

  8. Fatigue classification of welded joints in orthotropic steel bridge decks

    NARCIS (Netherlands)

    Kolstein, M.H.

    2007-01-01

    This dissertation presents the research into fatigue classifications of welded joints in orthotropic steel bridge decks. These classifications are needed to calculate the fatigue life of these joints and should be included in the design codes. For years bridge design was mainly based on static loadi

  9. Reply to Discussion: a critique of Possible waterways between the Marmara Sea and the Black Sea in the late Quaternary: evidence from ostracod and foraminifer assemblages in lakes İznik and Sapanca, Turkey, Geo-Marine Letters, 2011

    Science.gov (United States)

    Nazik, Atike; Meriç, Engin; Avşar, Niyazi

    2012-06-01

    In their discussion of our 2011 paper dealing with possible waterways between the Marmara Sea and the Black Sea in the "late" Quaternary, based on data from ostracod and foraminifer assemblages in lakes İznik and Sapanca, Turkey, Yaltırak et al. (Geo-Mar Lett 32:267-274, 2012) essentially reject the idea of any links whatsoever, be they between the Marmara Sea and the lakes İznik and Sapanca, or further to the Black Sea via the valley of the Sakarya River. The evidence they provide in support of their view, however, is essentially circumstantial, in part conjectural, and also inconclusive considering the findings in favour of linkage between the Marmara Sea and the lakes at the very least, while the proposed connection with the Sakarya River valley remains speculative because of the lack of unambiguous data. On the other hand, Yaltırak et al. (Geo-Mar Lett 32:267-274, 2012) do raise valid points of concern which deserve careful future investigation, the most important being the possibility of sample contamination from dumped marine sediment used for construction purposes along some parts of the shore of Lake İznik. We agree that a concerted multidisciplinary effort is required to address the many unresolved issues in connection with the potential waterways proposed by us and others before us.

  10. Application of Artificial Intelligence for Bridge Deterioration Model.

    Science.gov (United States)

    Chen, Zhang; Wu, Yangyang; Li, Li; Sun, Lijun

    2015-01-01

    The deterministic bridge deterioration model updating problem is well established in bridge management, while the traditional methods and approaches for this problem require manual intervention. An artificial-intelligence-based approach was presented to self-updated parameters of the bridge deterioration model in this paper. When new information and data are collected, a posterior distribution was constructed to describe the integrated result of historical information and the new gained information according to Bayesian theorem, which was used to update model parameters. This AI-based approach is applied to the case of updating parameters of bridge deterioration model, which is the data collected from bridges of 12 districts in Shanghai from 2004 to 2013, and the results showed that it is an accurate, effective, and satisfactory approach to deal with the problem of the parameter updating without manual intervention.

  11. Anthropogenic sources stimulate resonance of a natural rock bridge

    Science.gov (United States)

    Moore, Jeffrey R.; Thorne, Michael S.; Koper, Keith D.; Wood, John R.; Goddard, Kyler; Burlacu, Relu; Doyle, Sarah; Stanfield, Erik; White, Benjamin

    2016-09-01

    The natural modes of vibration of bedrock landforms, as well as the sources and effects of stimulated resonance remain poorly understood. Here we show that seismic energy created by an induced earthquake and an artificial reservoir has spectral content coincident with the natural modes of vibration of a prominent rock bridge. We measured the resonant frequencies of Rainbow Bridge, Utah using data from two broadband seismometers placed on the span, and identified eight distinct vibrational modes between 1 and 6 Hz. A distant, induced earthquake produced local ground motion rich in 1 Hz energy, stimulating a 20 dB increase in measured power at the bridge's fundamental mode. Moreover, we establish that wave action on Lake Powell, an artificial reservoir, generates microseismic energy with peak power ~1 Hz, also exciting resonance of Rainbow Bridge. These anthropogenic sources represent relatively new energy input for the bridge with unknown consequences for structural fatigue.

  12. Vibration characteristics and damage detection in a suspension bridge

    Science.gov (United States)

    Wickramasinghe, Wasanthi R.; Thambiratnam, David P.; Chan, Tommy H. T.; Nguyen, Theanh

    2016-08-01

    Suspension bridges are flexible and vibration sensitive structures that exhibit complex and multi-modal vibration. Due to this, the usual vibration based methods could face a challenge when used for damage detection in these structures. This paper develops and applies a mode shape component specific damage index (DI) to detect and locate damage in a suspension bridge with pre-tensioned cables. This is important as suspension bridges are large structures and damage in them during their long service lives could easily go un-noticed. The capability of the proposed vibration based DI is demonstrated through its application to detect and locate single and multiple damages with varied locations and severity in the cables of the suspension bridge. The outcome of this research will enhance the safety and performance of these bridges which play an important role in the transport network.

  13. Solving Topological and Geometrical Constraints in Bridge Feature Model

    Institute of Scientific and Technical Information of China (English)

    PENG Weibing; SONG Liangliang; PAN Guoshuai

    2008-01-01

    The capacity that computer can solve more complex design problem was gradually increased.Bridge designs need a breakthrough in the current development limitations, and then become more intelli-gent and integrated. This paper proposes a new parametric and feature-based computer aided design (CAD) models which can represent families of bridge objects, includes knowledge representation, three-dimensional geometric topology relationships. The realization of a family member is found by solving first the geometdc constraints, and then the topological constraints. From the geometric solution, constraint equations are constructed. Topology solution is developed by feature dependencies graph between bridge objects. Finally, feature parameters are proposed to drive bridge design with feature parameters. Results from our implementation show that the method can help to facilitate bridge design.

  14. A CAD/CAM system for operating overburden conveyor bridges

    Energy Technology Data Exchange (ETDEWEB)

    Pause, M.; Nadeborn, H.; Klus, R.

    1988-01-01

    Reviews introduction of computer systems for control of conveyor bridges for overburden removal in GDR brown coal surface mines. Three F 60 high capacity bridges at Welzow, Nochten and Jaenschwalde have been automated since 1978, achieving a 10% increase in annual production. A pilot project of complex automation of a F 45 brige at the Meuro mine was started to fully automate bridge movement according to continuous mine geometrical digital survey data. Hardware employed is the U 5000 control system with various peripheral equipment, the A 5120 office computer and the EC 1040 data processing unit. Automation of the Meuro bridge resulted in an annual economic benefit of 2.8 million Marks. A new, fourth F 60 bridge for which a CAD/CAM system based on the U 5000 and K 1520 computer systems is being developed will begin operation at the Reichwalde mine.

  15. Advanced aerostatic analysis of long-span suspension bridges

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    As the span length of suspension bridges increases, the diameter of cables and thus the wind load acting on them, the nonlinear wind-structure interaction and the wind speed spatial non-uniformity all increase consequently, which may have unnegligible influence on the aerostatic behavior of long-span suspension bridges. In this work, a method of advanced aerostatic analysis is presented firstly by considering the geometric nonlinearity, the nonlinear wind-structures and wind speed spatial non-uniformity. By taking the Runyang Bridge over the Yangtze River as example, effects of the nonlinear wind-structure interaction, wind speed spatial non-uniformity, and the cable's wind load on the aerostatic behavior of the bridge are investigated analytically. The results showed that these factors all have important influence on the aerostatic behavior, and should be considered in the aerostatic analysis of long and particularly super long-span suspension bridges.

  16. Use of UHPC in Bridge Structures: Material Modeling and Design

    Directory of Open Access Journals (Sweden)

    Oguz Gunes

    2012-01-01

    Full Text Available Ultra-high-performance concrete (UHPC is a promising new class of concrete material that is likely to make a significant contribution to addressing the challenges associated with the load capacity, durability, sustainability, economy, and environmental impact of concrete bridge infrastructures. This paper focuses on the material modeling of UHPC and design of bridge girders made of UHPC. A two-phase model used for modeling the behavior of UHPC was briefly discussed, and the model was implemented in a preliminary design case study. Based on the implemented design and the reported use of UHPC in bridge applications, the advantages, limitations, and future prospects of UHPC bridges were discussed, highlighting the need for innovative research and design to make optimum use of the favorable properties of the material in bridge structures.

  17. Vigorous convection in a sunspot granular light bridge

    CERN Document Server

    Lagg, Andreas; van Noort, Michiel; Danilovic, Sanja

    2014-01-01

    Light bridges are the most prominent manifestation of convection in sunspots. The brightest representatives are granular light bridges composed of features that appear to be similar to granules. An in-depth study of the convective motions, temperature stratification, and magnetic field vector in and around light bridge granules is presented with the aim of identifying similarities and differences to typical quiet-Sun granules. Spectropolarimetric data from the Hinode Solar Optical Telescope were analyzed using a spatially coupled inversion technique to retrieve the stratified atmospheric parameters of light bridge and quiet-Sun granules. Central hot upflows surrounded by cooler fast downflows reaching 10 km/s clearly establish the convective nature of the light bridge granules. The inner part of these granules in the near surface layers is field free and is covered by a cusp-like magnetic field configuration. We observe hints of field reversals at the location of the fast downflows. The quiet-Sun granules in ...

  18. Application of Artificial Intelligence for Bridge Deterioration Model

    Directory of Open Access Journals (Sweden)

    Zhang Chen

    2015-01-01

    Full Text Available The deterministic bridge deterioration model updating problem is well established in bridge management, while the traditional methods and approaches for this problem require manual intervention. An artificial-intelligence-based approach was presented to self-updated parameters of the bridge deterioration model in this paper. When new information and data are collected, a posterior distribution was constructed to describe the integrated result of historical information and the new gained information according to Bayesian theorem, which was used to update model parameters. This AI-based approach is applied to the case of updating parameters of bridge deterioration model, which is the data collected from bridges of 12 districts in Shanghai from 2004 to 2013, and the results showed that it is an accurate, effective, and satisfactory approach to deal with the problem of the parameter updating without manual intervention.

  19. Simulation of the Whole Process of Ship-Bridge Collision

    Institute of Scientific and Technical Information of China (English)

    刘建成; 顾永宁

    2002-01-01

    The simulation of the whole ship-bridge collision process can be effectively carried out by nonlinear dynamic finiteelement method. Based on the simple description of the theory, a scenario of a 40000 DWT oil tanker colliding with abridge across the Yangtze River is designed for simulation. The technology of structure modeling and the determination ofrelated parameters are introduced. The deformation of the bulb bow, the history of collision force change, the exchange ofcollision energy and the stress distribution of the bridge pier are described in detail, which are of great value to bridge de-sign and bridge pier damage estimation, Some mechanical characters in the process of ship-bridge collision are described.More accurate results can be produced by finite element method than that by empirical formulas and simplified analyticalmethods.

  20. Several solutions of remote transmission for state monitoring of bridges

    Institute of Scientific and Technical Information of China (English)

    LIANG Zong-bao; CHEN Wei-min; ZHU Yong; FU Yu-mei; XU Mou; YANG Hong

    2005-01-01

    The research for remote monitoring of bridges is expected to develop methodologies and tools for collecting state data, monitoring the real-time status of the bridge from distance, and more importantly seeking a best way for remote transmission of bridge monitoring system by comparing the characteristics of each scheme. This paper focuses on the solutions to remote transmission for state monitoring of bridges, which deals with the remote transmission system based on PSTN (Public Service Telephone Network), wireless sensor monitoring system and remote transmission using SDH (Synchronous Digital Hierarchy) network. As a result, a combination of wireless sensor monitoring system and the remote sensing system using SDH network is proposed to be the considered way for remote state monitoring of bridges.

  1. EXPERIMENTAL STUDY OF THE MORPHOLOGY OF CEREBRAL BRIDGING VEIN

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective. To investigate the morphological properties of pig cerebral bridging vein. Methods. The morphology and fibre arrangement of 15 cerebral bridging veins obtained from 7 Danish Yorkshire landrace pigs were observed. Results. There was a narrow region at the junction of the cerebral bridging veins and superior sagittal sinus termed “ outflow cuff segment". The diameter and length of outflow cuff segment were much smaller and the thickness was higher than those of the cerebral bridging veins (P0.05). Conclusions. There were differences in fibre arrangement and morphological properties between the outflow cuff segment and the cerebral bridging vein, just like a resistance valve, the outflow cuff segment may play an important role in stabilizing cerebral venous outflow and regulating intracranial pressure.

  2. Floating and flying ferrofluid bridges induced by external magnetic fields

    Science.gov (United States)

    Ma, Rongchao; Zhou, Yixin; Liu, Jing

    2015-04-01

    A ferrofluid is a mixture that exhibits both magnetism and fluidity. This merit enables the ferrofluid to be used in a wide variety of areas. Here we show that a floating ferrofluid bridge can be induced between two separated boards under a balanced external magnetic field generated by two magnets, while a flying ferrofluid bridge can be induced under an unbalanced external magnetic field generated by only one magnet. The mechanisms of the ferrofluid bridges were discussed and the corresponding mathematical equations were also established to describe the interacting magnetic force between the ferro particles inside the ferrofluid. This work answered a basic question that, except for the well-known floating water bridges that are related to electricity, one can also build up a liquid bridge that is related to magnetism.

  3. Transient response of piles-bridge under horizontal excitation

    Institute of Scientific and Technical Information of China (English)

    朱斌; 陈仁朋; 陈云敏

    2003-01-01

    Moving ships and other objects drifting on water often impact a bridge' s pile foundations. The mechanical model of the piles-bridge structure under horizontal forcing was established, and a time-domain approach based on Finite-difference Method was developed for analyzing the dynamic response of the piles-bridge structure. For a single pile, good agreement between two computed results validated the present approach.The slenderness ratio of the pile, the pile-soil stiffness ratio and the type of the structure influence the dynamic response of the piles-bridge structure. The computed results showed that the stiffness of the structure determines the dynamic response of the piles-bridge structure under horizontal forcing.

  4. Transient response of piles-bridge under horizontal excitation

    Institute of Scientific and Technical Information of China (English)

    朱斌; 陈仁朋; 陈云敏

    2003-01-01

    Moving ships and other objects drifting on water often impact a bridge's pile foundations. The mechanical model of the piles-bridge structure under horizontal forcing was established, and a time-domain approach based on Finite-difference Method was developed for analyzing the dynamic response of the piles-bridge structure. For a single pile, good agreement between two computed results validated the present approach. The slenderness ratio of the pile, the pile-soil stiffness ratio and the type of the structure influence the dynamic response of the piles-bridge structure. The computed results showed that the stiffness of the structure determines the dynamic response of the piles-bridge structure under horizontal forcing.

  5. Technology and organization in bridge construction by using movable scaffolding system

    OpenAIRE

    Rosa, Simon

    2008-01-01

    The thesis presents construction of a bridge presented on a case study of the Šumljak bridge. The bridge is located on the motorway section Razdrto-Vipava characterized by an extremely complexe morphology and geology, which makes the bridge location one of the most demanding parts to be bridged within the Slovenian National Highway Construction Programme. The "S" shaped bridge axis dictates the use of the field by field construction method on mechanized movable scaffolding. This technology en...

  6. Experimental and Analytical Investigations of Piles and Abutments of Integral Bridges

    OpenAIRE

    Arsoy, Sami

    2000-01-01

    Bridges without expansion joints are called "integral bridges." Eliminating joints from bridges crates concerns for the piles and the abutments of integral bridges because the abutments and the piles are subjected to temperature-induced cyclic lateral loads. As temperatures change daily and seasonally, the lengths of integral bridges increase and decrease, pushing the abutment against the approach fill and pulling it away. As a result the bridge superstructure, the abutment, the approach f...

  7. Influence of the new LRFD seismic guidelines on the design of bridges in Virginia

    OpenAIRE

    M.A. Widjaja; Roberts-Wollmann, Carin L.

    2004-01-01

    The Virginia Department of Transportation is currently using the AASHTO Standard Specifications for Highway Bridges, with some modifications, for its seismic highway bridge design. In April 2001, the Recommended LRFD Guidelines for the Seismic Design of Highway Bridges were published. The influence of the LRFD Guidelines on Virginia bridges was investigated by analyzing two existing bridges. The first bridge has prestressed concrete girders and is located in the Richmond area. The second brid...

  8. IceBridge: Bringing a Field Campaign Home

    Science.gov (United States)

    Woods, J.; Beck, J.; Bartholow, S.

    2015-12-01

    IceBridge, a six-year NASA mission, is the largest airborne survey of Earth's polar ice ever flown. It will yield an unprecedented three-dimensional view of Arctic and Antarctic ice sheets, ice shelves and sea ice. These flights will provide a yearly, multi-instrument look at the behavior of the rapidly changing features of the Greenland and Antarctic ice. Data collected during IceBridge will help scientists bridge the gap in polar observations between NASA's Ice, Cloud and Land Elevation Satellite (ICESat) -- in orbit since 2003 -- and ICESat-2, planned for 2017. ICESat stopped collecting science data in 2009, making IceBridge critical for ensuring a continuous series of observations. IceBridge will use airborne instruments to map Arctic and Antarctic areas once a year at a minimum, with new campaigns being developed during the Arctic melt season. IceBridge flights are conducted in the spring and summer for the Arctic and in the fall over Antarctica. Other smaller airborne surveys around the world are also part of the IceBridge campaign. IceBridge actively engages the public and educators through a variety of outlets ranging from communications strategies through social media outlets, to larger organized efforts such as PolarTREC. In field activities include blog posts, photo updates, in flight chat sessions, and more intensive live events to include google hangouts, where field team members can interact with the public during a scheduled broadcast. The IceBridge team provides scientists and other team members with the training and support to become communicators in their own right. There is an exciting new initiative where IceBridge will be collaborating with Undergraduate and Graduate students to integrate the next generation of scientists and communicators into the Science Teams. This will be explored through partnerships with institutions that are interested in mentoring through project based initiatives.

  9. Bridging the gap with flipped classroom

    DEFF Research Database (Denmark)

    Selberg, Hanne; Topperzer, Martha

    2016-01-01

    Bridging the gap with flipped classroom Hanne Selberg, Metropolitan University College, Copenhagen, Martha Topperzer, University Hospital Rigshospitalet, Copenhagen, Denmark Background and aims Consistent with the strategy of increasing digitization and learner-centred teaching models...... in the nursing curriculum, we have reversed selected traditional lectures into simulation based teaching activities embedded in a ten week Pediatric Nursing module for third year nursing students. The current pilot study seeks to explore the impact on students’ learning and commitment when flipping the classroom...... using educational technologies such as online preparation contents and simulation based scenarios. Furthermore, the objective is to enhance theory-practice integration in the educational setting. Materials & Methods The flipped classroom model replaces three theoretical lectures addressing disease...

  10. Bridging Physics and Biology Teaching through Modeling

    CERN Document Server

    Hoskinson, Anne-Marie; Zwickl, Benjamin M; Hinko, Kathleen; Caballero, Marcos D

    2013-01-01

    As the frontiers of biology become increasingly interdisciplinary, the physics education community has engaged in ongoing efforts to make physics classes more relevant to life sciences majors. These efforts are complicated by the many apparent differences between these fields, including the types of systems that each studies, the behavior of those systems, the kinds of measurements that each makes, and the role of mathematics in each field. Nonetheless, physics and biology are both fundamental sciences that rely on observations and measurements to construct models of the natural world. In the present theoretical article, we propose that efforts to bridge the teaching of these two disciplines must emphasize shared scientific practices, particularly scientific modeling. We define modeling using language common to both disciplines and highlight how an understanding of the modeling process can help reconcile apparent differences between physics and biology. We elaborate how models can be used for explanatory, pre...

  11. Bridging Innovation and Curriculum in Higher Education

    DEFF Research Database (Denmark)

    Zhang, Fenzhi; Kolmos, Anette; Du, Xiangyun

    2010-01-01

    As innovation is seen as a key factor in economic competitiveness, graduates who can contribute to and participate in innovation are in great need.. Higher education is confronted with the demands that the curriculum practice and learning environments should facilitate innovation and competences...... for innovation. Problem and project based learning has been seen as a strategy for renewing the teaching practice and the learning environment by integrating the competence demands of the curriculum and of work life during the process of education. However, the integrations of innovation into curriculum...... are minor in the problem and project based learning (PBL) literature. Based on theoretical reflections and practical cases in Aalborg University (Denmark), this article presents the basis of PBL knowledge and curriculum conceptualization, and explores a case experience which bridges innovation and PBL...

  12. Helping System Engineers Bridge the Peaks

    Science.gov (United States)

    Rungta, Neha; Tkachuk, Oksana; Person, Suzette; Biatek, Jason; Whalen, Michael W.; Castle, Joseph; Castle, JosephGundy-Burlet, Karen

    2014-01-01

    In our experience at NASA, system engineers generally follow the Twin Peaks approach when developing safety-critical systems. However, iterations between the peaks require considerable manual, and in some cases duplicate, effort. A significant part of the manual effort stems from the fact that requirements are written in English natural language rather than a formal notation. In this work, we propose an approach that enables system engineers to leverage formal requirements and automated test generation to streamline iterations, effectively "bridging the peaks". The key to the approach is a formal language notation that a) system engineers are comfortable with, b) is supported by a family of automated V&V tools, and c) is semantically rich enough to describe the requirements of interest. We believe the combination of formalizing requirements and providing tool support to automate the iterations will lead to a more efficient Twin Peaks implementation at NASA.

  13. Live-Load Testing and Finite-Element Analysis of a Steel Cantilever Deck Arched Pratt Truss Bridge for the Long-Term Bridge Performance Program

    OpenAIRE

    Laurendeau, Matthew P.

    2011-01-01

    The Long Term Bridge Performance (LTBP) program is an organization within the Federal Highway Administration that inspects, tests, analyzes, and observes, for an extended period of time, a variety of bridge types throughout the United States. Part of the program includes periodic testing of select bridges of a span of 20 years. The Kettle River Bridge located outside of Sandstone, Minnesota was selected for study due to its unique design. The Kettle River Bridge is a historical steel can...

  14. 75 FR 5511 - Safety Zone; AICW Closure Safety Zone for Ben Sawyer Bridge Replacement Project, Sullivan's...

    Science.gov (United States)

    2010-02-03

    ... person is allowed in this zone unless authorized by the Captain of the Port or a designated... equipment and machinery in the waterway, could lead to severe injury, fatalities and/or destruction of... debris and the use of heavy equipment and machinery. To provide for the safety of the public, the...

  15. 78 FR 61937 - Safety Zone; Port of Galveston, Pelican Island Bridge Repair

    Science.gov (United States)

    2013-10-07

    ... Security FR Federal Register NPRM Notice of Proposed Rulemaking TFR Temporary Final Rule A. Regulatory... Castaneda, Chief of Waterways Management Division, U.S. Coast Guard Sector Houston Galveston; telephone (713) 671-5164, email Xochitl.L.Castaneda@uscg.mil . If you have questions on viewing or submitting...

  16. Impact Coefficient Analysis of Long-Span Railway Cable-Stayed Bridge Based on Coupled Vehicle-Bridge Vibration

    Directory of Open Access Journals (Sweden)

    Yongle Li

    2015-01-01

    Full Text Available Compared with medium and small span bridges, very limited attention has been paid on the research of the impact coefficient of long-span railway bridges. To estimate the impact effects of long-span railway bridges subjected to moving vehicles, a real long-span railway cable-stayed bridge is regarded as the research object in this study, and a coupled model of vehicle-bridge system is established. The track irregularities are taken as the system excitation and the dynamic responses of the vehicle-bridge system are calculated. The impact effects on main girder, stayed cable, bearings, and bridge tower are discussed at various vehicle speeds. The results show that different components of the long-span railway cable-stayed bridge have different impact coefficients. Even for each part, the impact coefficient is also different at different local positions. It reveals that the impact coefficients in the actual situation may have significant differences with the related code clauses in the present design codes.

  17. Numerical analysis of dynamic response of vehicle–bridge coupled system on long-span continuous girder bridge

    Directory of Open Access Journals (Sweden)

    Lipeng An

    2016-07-01

    Full Text Available To systematically study the vehicle–bridge coupled dynamic response and its change rule with different parameters, a vehicle model with seven degrees of freedom was built and the total potential energy of vehicle space vibration system was deduced. Considering the stimulation of road roughness, the dynamic response equation of vehicle–bridge coupled system was established in accordance with the elastic system principle of total potential energy with stationary value and the “set-in-right-position” rule. On the basis of the self-compiled Fortran program and bridge engineering, the dynamic response of long-span continuous girder bridge under vehicle load was studied. This study also included the calculation of vehicle impact coefficient, evaluation of vibration comfort, and analysis of dynamic response parameters. Results show the impact coefficient changes with lane number and is larger than the value calculated by the “general code for design of highway bridges and culverts (China”. The Dieckmann index of bridge vibration is also related to lane number, and the vibration comfort evaluation is good in normal conditions. The relevant conclusions from parametric analyses have practical significance to dynamic design and daily operation of long-span continuous girder bridges in expressways. Safety and comfort are expected to improve significantly with further control of the vibration of vehicle–bridge system.

  18. Implementation of a Non-Metallic Reinforced Bridge Deck, Volume 2: Thayer Road Bridge

    OpenAIRE

    Frosch, Robert J.; Pay, Ali Cihan

    2006-01-01

    The primary maintenance problem with bridges in Indiana has been deterioration of the concrete deck which is often related to corrosion of the reinforcing steel. While a corrosion protection system consisting of epoxy-coated reinforcement in combination with 2-1/2 in. of Class C concrete cover has been used in Indiana, research and experience have demonstrated that this system can be compromised. As an alternative solution to the corrosion problem in reinforced concrete, fiber reinforced poly...

  19. Electronic Coupling in [Mo2]-Bridge-[Mo2] Systems with Twisted Bridges.

    Science.gov (United States)

    Zhang, Hong Li; Zhu, Guang Yuan; Wang, Gangyi; Meng, Miao; Liu, Chun Y; Lei, Hao

    2015-12-01

    In order to evaluate the impact of bridge conformation on electronic coupling in donor-bridge-acceptor triad systems, two Mo2 dimers, [Mo2(DAniF)3]2[μ-1,4-{C(O)NH}2-Naph] (1, DAniF = N,N'-di(p-anisyl)formamidinate and Naph = naphthalenyl) and [Mo2(DAniF)3]2[μ-1,4-(CS2)2-2,5-Me2C6H2] (2), have been synthesized and structurally characterized. These two compounds feature a large dihedral angle (>60°) between the central aromatic ring and the plane defined by the Mo-Mo bond vectors, which is distinct from the previously reported phenylene bridged analogues [Mo2(DAniF)3]2[μ-1,4-{C(O)NH}2-ph] (I) and [Mo2(DAniF)3]2[μ-1,4-(CS2)2-C6H4] (II), respectively. Unusual optical behaviors are observed for the mixed-valence (MV) species (1(+) and 2(+)), generated by single-electron oxidation. While 2(+) exhibits a weak intervalence charge transfer (IVCT) absorption band in the near-IR region, the IVCT band is absent in the spectrum of 1(+), which is quite different from what observed for I(+) and II(+). Optical analyses, based on superexchange formalism and Hush model, indicate that, in terms of Robin-Day classification, mixed-valence species 1(+) belongs to the electronically uncoupled Class I and complex 2(+), with Hab = 220 cm(-1), is assigned to the weakly coupled Class II. Together with I(+) and II(+), the four MV complexes complete a transition from Class I to Class II-III borderline as a result of manipulating the geometric topology of the bridge. Given the structural and electronic features for the molecular systems, the impacts of electrostatic interaction (through-space) and electron resonance (through-bond) on electronic coupling are discussed. PMID:26579936

  20. Bridge Management Strategy Based on Extreme User Costs for Bridge Network Condition

    Directory of Open Access Journals (Sweden)

    Ladislaus Lwambuka

    2014-01-01

    Full Text Available This paper presents a practical approach for prioritization of bridge maintenance within a given bridge network. The maintenance prioritization is formulated as a multiobjective optimization problem where the simultaneous satisfaction of several conflicting objectives includes minimization of maintenance costs, maximization of bridge deck condition, and minimization of traffic disruption and associated user costs. The prevalence of user cost during maintenance period is twofold; the first case refers to the period of dry season where normally the traffic flow is diverted to alternative routes usually resurfaced to regain traffic access. The second prevalence refers to the absence of alternative routes which is often the case in the least developed countries; in this case the user cost referred to results from the waiting time while the traffic flow is put on hold awaiting accomplishment of the maintenance activity. This paper deals with the second scenario of traffic closure in the absence of alternative diversion routes which in essence results in extreme user cost. The paper shows that the multiobjective optimization approach remains valid for extreme cases of user costs in the absence of detour roads as often is the scenario in countries with extreme poor road infrastructure.

  1. Development of a numerical model for vehicle-bridge interaction analysis of railway bridges

    Science.gov (United States)

    Kim, Hee Ju; Cho, Eun Sang; Ham, Jun Su; Park, Ki Tae; Kim, Tae Heon

    2016-04-01

    In the field of civil engineering, analyzing dynamic response was main concern for a long time. These analysis methods can be divided into moving load analysis method and moving mass analysis method, and formulating each an equation of motion has recently been studied after dividing vehicles and bridges. In this study, the numerical method is presented, which can consider the various train types and can solve the equations of motion for a vehicle-bridge interaction analysis by non-iteration procedure through formulating the coupled equations for motion. Also, 3 dimensional accurate numerical models was developed by KTX-vehicle in order to analyze dynamic response characteristics. The equations of motion for the conventional trains are derived, and the numerical models of the conventional trains are idealized by a set of linear springs and dashpots with 18 degrees of freedom. The bridge models are simplified by the 3 dimensional space frame element which is based on the Euler-Bernoulli theory. The rail irregularities of vertical and lateral directions are generated by PSD functions of the Federal Railroad Administration (FRA).

  2. Bridge Pressure Flow Scour at Clear Water Threshold Condition

    Institute of Scientific and Technical Information of China (English)

    GUO Junke; KERENYI Kornel; PAGAN-ORTIZ Jorge E; FLORA Kevin

    2009-01-01

    Bridge pressure flow scour at clear water threshold condition is studied theoretically and experimentally. The flume experiments reveal that the measured scour profiles under a bridge are more or less 2-dimensional; all the measured scour profiles can be described by two similarity equations, where the horizontal distance is scaled by the deck width while the local scour by the maximum scour depth; the maximum scour position is located just under the bridge about 15% deck width from the downstream deck edge; the scour begins at about one deck width upstream the bridge while the deposition occurs at about 2.5 deck widths downstream the bridge; and the maximum scour depth decreases with increas-ing sediment size, but increases with deck inundation. The theoretical analysis shows that: bridge scour can be divided into three cases, i.e. downstream unsubmerged, partially submerged, and totally submerged. For downstream unsubmerged flows, the maximum bridge scour depth is an open-channel problem where the conventional methods in terms of critical velocity or bed shear stress can be applied; for partially and totally submerged flows, the equilibrium maximum scour depth can be described by a scour and an inundation similarity number, which has been confirmed by experiments with two decks and two sediment sizes. For application, a design and field evaluation procedure with examples is presented, including the maximum scour depth and scour profile.

  3. Seismic response of skewed RC box-girder bridges

    Institute of Scientific and Technical Information of China (English)

    Ahmed Abdel-Mohti; Gokhan Pekcan

    2008-01-01

    It is critical to ensure the functionality of highway bridges after earthquakes to provide access to important facilities.Since the 1971 San Fernando earthquake,there has been a better understanding of the seismic performance of bridges.Nonetheless,there are no detailed guidelines addressing the performance of skewed highway bridges.Several parameters affect the response of skewed highway bridges under both service and seismic loads which makes their behavior complex.Therefore,there is a need for more research to study the effect of skew angle and other related factors on the performance of highway bridges.This paper examines the seismic performance of a three-span continuous concrete box girder bridge with skew angles from 0 to 60 degrees,analytically.Finite element (FE) and simplified beam-stick (BS) models of the bridge were developed using SAP2000.Different types of analysis were considered on both models such as:nonlinear static pushover,and linear and nonlinear time history analyses.A comparison was conducted between FE and BS,different skew angles,abutment support conditions,and time history and pushover analysis.It is shown that the BS model has the capability to capture the coupling due to skew and the significant modes for moderate skew angles.Boundary conditions and pushover load profile are determined to have a major effect on pushover analysis.Pushover analysis may be used to predict the maximum deformation and hinge formation adequately.

  4. Analysis of resonance mechanism and conditions of train bridge system

    Science.gov (United States)

    Xia, H.; Zhang, N.; Guo, W. W.

    2006-11-01

    In this paper, the resonance mechanism and conditions of train-bridge system are investigated through theoretical derivations, numerical simulations and experimental data analyses. The resonant responses of the bridge induced by moving trains are classified into three types according to different resonance mechanisms: the first is related to the periodical actions of moving load series of the vertical weights, lateral centrifugal and wind forces of vehicles; the second is induced by the loading rate of moving load series of vehicles; the third is owing to the periodically loading of the swing forces of the train vehicles excited by track irregularities and wheel hunting movements. The vehicle resonance is induced by the periodical action of regular arrangement of bridge spans and their deflections. The resonant conditions are proposed and the corresponding resonant train speeds are determined. The application scopes of resonance conditions are discussed. The resonance of the train-bridge system is affected by the span, total length, lateral and vertical stiffness of the bridge, the compositions of the train, and the axle arrangements and natural frequencies of the vehicles. The resonant train speeds for some bridges are estimated and are compared with the critical train speeds obtained from the dynamic simulation of train-bridge interaction model or from the field measurements.

  5. State-of-the-art of long-span bridge engineering in China

    Institute of Scientific and Technical Information of China (English)

    XIANG Haifan; GE Yaojun

    2007-01-01

    This paper introduces the state-of-the-art of long-span bridge engineering in China with emphases on recent long-span bridge projects,bridge deck configuration and material,design codes of long-span bridges and improvement of aerodynamic performance.The recent long-span bridge projects include thirty-eight completed suspension bridges,cable-stayed and arch bridges with a main span over 400 m,and eighteen major bridges are under construction.The bridge deck configuration and material,with prestressed concrete decks,steel-concrete composite decks and steel box decks together with several popular cross-sections,are presented.The third part briefly outlines four design codes,including static and dynamic design for highway long-span bridges,and the recent engineering experiences gained from several aerodynamic vibration control projects of long-span bridges are shared in the last part.

  6. A simplified fragility analysis of fan type cable stayed bridges

    Institute of Scientific and Technical Information of China (English)

    R. A. Khan; T. K. Datta; S. Ahmad

    2005-01-01

    A simplified fragility analysis of fan type cable stayed bridges using Probabilistic Risk Analysis (PRA)procedure is presented for determining their failure probability under random ground motion. Seismic input to the bridge support is considered to be a risk consistent response spectrum which is obtained from a separate analysis. For the response analysis, the bridge deck is modeled as a beam supported on springs at different points. The stiffnesses of the springs are determined by a separate 2D static analysis of cable-tower-deck system. The analysis provides a coupled stiffness matrix for the spring system. A continuum method of analysis using dynamic stiffness is used to determine the dynamic properties of the bridges .The response of the bridge deck is obtained by the response spectrum method of analysis as applied to multidegree of freedom system which duly takes into account the quasi - static component of bridge deck vibration. The fragility analysis includes uncertainties arising due to the variation in ground motion, material property, modeling, method of analysis,ductility factor and damage concentration effect. Probability of failure of the bridge deck is determined by the First Order Second Moment (FOSM) method of reliability. A three span double plane symmetrical fan type cable stayed bridge of total span 689 m, is used as an illustrative example. The fragility curves for the bridge deck failure are obtained under a number of parametric variations. Some of the important conclusions of the study indicate that (i) not only vertical component but also the horizontal component of ground motion has considerable effect on the probability of failure; (ii) ground motion with no time lag between support excitations provides a smaller probability of failure as compared to ground motion with very large time lag between support excitation; and (iii) probability of failure may considerably increase for soft soil condition.

  7. Surface salt bridges stabilize the GCN4 leucine zipper.

    OpenAIRE

    Spek, E. J.; Bui, A. H.; Lu, M.; Kallenbach, N R

    1998-01-01

    We present a study of the role of salt bridges in stabilizing a simplified tertiary structural motif, the coiled-coil. Changes in GCN4 sequence have been engineered that introduce trial patterns of single and multiple salt bridges at solvent exposed sites. At the same sites, a set of alanine mutants was generated to provide a reference for thermodynamic analysis of the salt bridges. Introduction of three alanines stabilizes the dimer by 1.1 kcal/mol relative to the wild-type. An arrangement c...

  8. Experiences with a two terminal-pair digital impedance bridge

    CERN Document Server

    Callegaro, Luca; Kampik, Marian; Kim, Dan Bee; Ortolano, Massimo; Pourdanesh, Faranak

    2014-01-01

    This paper describes the realization of a two terminal-pair digital impedance bridge and the test measurements performed with it. The bridge, with a very simple architecture, is based on a commercial two-channel digital signal synthesizer and a synchronous detector. The bridge can perform comparisons between impedances having arbitrary phase and magnitude ratio: its balance is achieved automatically in less than a minute. $R$-$C$ comparisons with calibrated standards, at kHz frequency and 100 kohm magnitude level, give ratio errors of the order of $10^{-6}$, with potential for further improvements.

  9. Definition and segmentation of BioMedBridges stakeholders

    OpenAIRE

    Brooksbank, Cath; Alfarez, Deborah

    2014-01-01

    The success of BioMedBridges will depend on outreach and inreach to diverse groups of stakeholders. This deliverable report describes the use of a survey to define the broad stakeholder groups with whom BioMedBridges needs to engage, and to collect information on how the individual ESFRI-BMS RIs currently engage with these groups. We wanted to know who these stakeholders are, how the RIs are currently engaging with them, and what aspects of BioMedBridges the respondents felt we should be cons...

  10. SiC MOSFETs based split output half bridge inverter

    DEFF Research Database (Denmark)

    Li, Helong; Munk-Nielsen, Stig; Beczkowski, Szymon;

    2014-01-01

    . This paper makes the current commutation mechanism and efficiency analysis of half bridge with split output based on SiC MOSFETs. Current commutation process analysis is illustrated together with LTspice simulation and afterwards, verified by the experimental results of a double pulse test circuit with split...... output. The double pulse test shows the devices' current during commutation process and the reduced switching losses of SiC MOSFETs compared to that of the traditional half bridge. The efficiency comparison is presented with experimental results of half bridge power inverter with split output...

  11. Experimental Investigation of Aerodynamic Instability of Iced Bridge Cable Sections

    DEFF Research Database (Denmark)

    Koss, Holger; Lund, Mia Schou Møller

    2013-01-01

    The accretion of ice on structural bridge cables changes the aerodynamic conditions of the surface and influences hence the acting wind load process. Full-scale monitoring indicates that light precipitation at moderate low temperatures between zero and -5°C may lead to large amplitude vibrations...... of bridge cables under wind action. This paper describes the experimental simulation of ice accretion on a real bridge cable sheet HDPE tube segment (diameter 160mm) and its effect on the aerodynamic load. Furthermore, aerodynamic instability will be estimated with quasi-steady theory using the determined...

  12. Future Trends in Reliability-Based Bridge Management

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    Future bridge management systems will be based on simple stochastic models predicting the residual strength of structural elements. The current deterministic management systems are not effective in optimizing e.g. the life cycle cost of a bridge or a system of bridges. A number of important facto...... are so uncertain that they cannot be modelled satisfactorily by deterministic techniques. In recent years several researchers have studied stochastic modelling of e.g. deterioration, inspection, reliability, and repair but real applications are only reported in a few cases....

  13. A Voltage Mode Memristor Bridge Synaptic Circuit with Memristor Emulators

    Directory of Open Access Journals (Sweden)

    Leon Chua

    2012-03-01

    Full Text Available A memristor bridge neural circuit which is able to perform signed synaptic weighting was proposed in our previous study, where the synaptic operation was verified via software simulation of the mathematical model of the HP memristor. This study is an extension of the previous work advancing toward the circuit implementation where the architecture of the memristor bridge synapse is built with memristor emulator circuits. In addition, a simple neural network which performs both synaptic weighting and summation is built by combining memristor emulators-based synapses and differential amplifier circuits. The feasibility of the memristor bridge neural circuit is verified via SPICE simulations.

  14. Progressive collapse susceptibility of a long span suspension bridge

    DEFF Research Database (Denmark)

    Olmati, Pierluigi; Giuliani, Luisa

    2013-01-01

    should be maintained in case of an accidental hanger detachment. Local damages in bridges, which are characterized by an horizontal load transfer system, may progress along the deck or along the suspension system, as the dynamic overloading of the structural elements immediately adjacent to the failed...... ones may lead to subsequent failures. In suspension bridges, which are characterized by a relatively low continuity of the system, the damage of the deck may favor a collapse standstill, in case of an early detachment of the deck collapsing section. In the paper, a long span suspension bridge is taken...

  15. Fracture resistance on aggregate bridging crack in concrete

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiufang; XU Shilang

    2007-01-01

    Fracture toughening exhibited in quasi-brittle materials such as concrete is often mainly related to the action of aggregate bridging,which leads to the presence of a fracture process zone ahead of stress-free cracks in such materials.In this investigation,the fracture resistance induced by aggregate bridging,denoted by GI-bridging,is the primary focus.In order to quantitatively determine it,a general analytical formula is firstly developed,based on the definition of fracture energy by Hillerborg.After this,we further present the calculated procedures of determining this fracture resistance from the recorded load vs.crack opening displacement curve.Then,both numerical simulations and fracture experiments are performed on concrete three-point bending beams.Utilizing the obtained load against crack opening displacement curve,the value of GI-bridging at any crack extension as well as the change of GI-bridging with the crack extension is examined.It is found that GI-bridging will firstly increase with the development of crack and then stay constant once the initial crack tip opening displacement reaches the characteristic crack opening displacement w0.The effects of material strength and specimen depth on this fracture resistance are also investigated.The results reveal that the values of GI-bridging of different specimens at any crack propagation are strongly associated with the values of fracture energy of specimens.If the values of fracture energy between different specimens are comparable,the differences between GI-bridging are ignored.Instead,if values of fracture energy are different,the GI-bridging will be different.This shows that for specimens with different strengths,GI-bridging will change greatly whereas for specimens that are different in depth,whether GI-bridging exhibits size effect depends on whether the fracture energy of specimens considered in the calculation of GI-bridging is assumed to be a size-dependent material parameter.

  16. The Damage Analysis of Usu Bridge under Seismic Load

    Directory of Open Access Journals (Sweden)

    Jian-Hui Gao

    2014-02-01

    Full Text Available In order to obtain the dynamic response of Usu bridge the compression damage model of concrete materials and the finite element method are used in this study. The frequency and the main vibration mode of Usu bridge are calculated. The damage distribution and the location of maximum damage of concrete structures under the four kinds of seismic load are obtained. The results show that the maximum damage of bridge deck occurs in close to support position, the maximum compression damage of the main tower occurs in the upper tower root place. Therefore, in the construction and maintenance process note the influence of seismic load of in these positions.

  17. Myocardial bridges: their clinical implications and prognostic signs

    International Nuclear Information System (INIS)

    Among 980 consecutive selective coronary angiograms performed, nine patients had myocardial bridges of the left anterior descending (LAD) coronary artery. The overall prevalence of myocardial bridge was 0.92%. Among these patients, three patients had coronary artery disease, while six cases were isolated myocardial muscle bridges. With respect to functional abnormality, three had grade III milking effect, three had grade II and three had grade I milking effect. The indications for coronary angiograms were typical chest pain in seven cases and a typical chest pain in two cases. Their clinical and laboratory investigations are presented with literature review. (author)

  18. A micromechanical bridge-shaped voltage-controlled oscillator

    Institute of Scientific and Technical Information of China (English)

    HAN; Jianqiang; ZHU; Changchun; ZHAO; Hongpo; LIU; Junhua

    2004-01-01

    A novel micromechanical bridge-shaped voltage-controlled oscillator with high Q value was fabricated. The core of this kind of oscillators is an electrothermally excited and piezoresistively detected micromechanical bridge resonator. Its resonance frequency can be adjusted by changing the DC voltage applied to the Wheatstone bridge. Theoretical analysis and experimental data show that its resonance frequency is linear with the square of the DC voltage. The linearity is better than 0.16% and the adjustable frequency range excels 17.15%.

  19. Sectional model test study on vortex-excited resonance of vehicle-bridge system of Shanghai Bridge over Yangtse River

    Institute of Scientific and Technical Information of China (English)

    Li ZHOU; Yaojun GE

    2009-01-01

    It is necessary to study how vehicles influence the vortex-excited resonance of vehicle-bridge systems,because lock-in wind speed is low and vortex-excited resonance is sensitive to any change in the main girder sections. Based on the Shanghai Bridge over the Yangtse River, the vortex-excited resonance of a 1:60 scale sectional model was tested in a TJ-lwind tunnel, with or without vehicles at the attack angle of 0°, + 3 and -3°,respectively. The conversion relationships between the resonant amplitudes of the sectional model and that of the prototype bridge were also established by mode shape correction. The result indicates that: 1) for the bridge with vehicles, the vertical vortex-excited resonance is accom-panied by torsion vibration with the same frequency, and vice versa, 2) the amplitude of vortex-excited resonance of the bridge with vehicles is much larger than that of the bridge without vehicles, and 3) the lock-in wind speed of the vortex-excited resonance becomes smaller due to the disturbance of vehicles. It is obvious that vehicles bring about changes in the aerodynamic shape of the main girder.Therefore, the influence of vehicles on vortex-excited resonance performance of vehicle-bridge systems, in terms of both amplitude and mode, should not be ignored.

  20. Light Bridge in a Developing Active Region. I. Observation of Light Bridge and its Dynamic Activity Phenomena

    CERN Document Server

    Toriumi, Shin; Cheung, Mark C M

    2015-01-01

    Light bridges, the bright structures that divide the umbra of sunspots and pores into smaller pieces, are known to produce wide variety of activity events in solar active regions (ARs). It is also known that the light bridges appear in the assembling process of nascent sunspots. The ultimate goal of this series of papers is to reveal the nature of light bridges in developing ARs and the occurrence of activity events associated with the light bridge structures from both observational and numerical approaches. In this first paper, exploiting the observational data obtained by Hinode, IRIS, and Solar Dynamics Observatory (SDO), we investigate the detailed structure of the light bridge in NOAA AR 11974 and its dynamic activity phenomena. As a result, we find that the light bridge has a weak, horizontal magnetic field, which is transported from the interior by large-scale convective upflow and is surrounded by strong, vertical fields of adjacent pores. In the chromosphere above the bridge, a transient brightening ...

  1. Bridging the divide between science and journalism.

    Science.gov (United States)

    Van Eperen, Laura; Marincola, Francesco M; Strohm, Jennifer

    2010-01-01

    There are countless reasons nearly every scientist should learn how to communicate effectively with the media, including increased understanding of critical research findings to attract or sustain funding and build new professional partnerships that will further propel forward research. But where do scientists begin? Bridging the Divide between Science and Journalism offers practical tips for any scientist looking to work with the media.Given the traditional and internet-based sources for medical research and healthcare-related news now available, it is imperative that scientists know how to communicate their latest findings through the appropriate channels. The credible media channels are managed by working journalists, so learning how to package vast, technical research in a form that is appetizing and "bite-sized" in order to get their attention, is an art. Reducing years of research into a headline can be extremely difficult and certainly doesn't come naturally to every scientist, so this article provides suggestions on how to work with the media to communicate your findings. PMID:20219123

  2. Harmonic Oscillators as Bridges between Theories

    International Nuclear Information System (INIS)

    Other than scattering problems where perturbation theory is applicable, there are basically two ways to solve problems in physics. One is to reduce the problem to harmonic oscillators, and the other is to formulate the problem in terms of two-by-two matrices. If two oscillators are coupled, the problem combines both two-by-two matrices and harmonic oscillators. This method then becomes a powerful research tool to cover many different branches of physics. Indeed, the concept and methodology in one branch of physics can be translated into another through the common mathematical formalism. It is noted that the present form of quantum mechanics is largely a physics of harmonic oscillators. Special relativity is the physics of the Lorentz group which can be represented by the group of by two-by-two matrices commonly called SL(2, c). Thus the coupled harmonic oscillators can therefore play the role of combining quantum mechanics with special relativity. Both Paul A. M. Dirac and Richard P. Feynman were fond of harmonic oscillators, while they used different approaches to physical problems. Both were also keenly interested in making quantum mechanics compatible with special relativity. It is shown that the coupled harmonic oscillators can bridge these two different approaches to physics

  3. Harmonic Oscillators as Bridges between Theories

    Science.gov (United States)

    Kim, Y. S.; Noz, Marilyn E.

    2005-03-01

    Other than scattering problems where perturbation theory is applicable, there are basically two ways to solve problems in physics. One is to reduce the problem to harmonic oscillators, and the other is to formulate the problem in terms of two-by-two matrices. If two oscillators are coupled, the problem combines both two-by-two matrices and harmonic oscillators. This method then becomes a powerful research tool to cover many different branches of physics. Indeed, the concept and methodology in one branch of physics can be translated into another through the common mathematical formalism. It is noted that the present form of quantum mechanics is largely a physics of harmonic oscillators. Special relativity is the physics of the Lorentz group which can be represented by the group of by two-by-two matrices commonly called SL(2, c). Thus the coupled harmonic oscillators can therefore play the role of combining quantum mechanics with special relativity. Both Paul A. M. Dirac and Richard P. Feynman were fond of harmonic oscillators, while they used different approaches to physical problems. Both were also keenly interested in making quantum mechanics compatible with special relativity. It is shown that the coupled harmonic oscillators can bridge these two different approaches to physics.

  4. Simplified environmental study on innovative bridge structure.

    Science.gov (United States)

    Bouhaya, Lina; Le Roy, Robert; Feraille-Fresnet, Adélaïde

    2009-03-15

    The aim of this paper is to present a simplified life cycle assessment on an innovative bridge structure, made of wood and ultra high performance concrete, which combines mechanical performance with minimum environmental impact. The environmental analysis was conducted from cradle to grave using the Life Cycle Assessment method. It was restricted to energy release and greenhouse gas emissions. Assumptions are detailed for each step of the analysis. For the wood end-of-life, three scenarios were proposed: dumping, burning, and recycling. Results show that the most energy needed is in the production phase, which represents 73.4% of the total amount. Analysis shows that the renewable energy is about 70% of the production energy. Wood, through its biomass CO2, contributes positively to the environmental impact. It was concluded that no scenario can be the winner on both impacts. Indeed, the end-of-life wood recycling gives the best impact on CO2 release, whereas burning wood, despite its remarkable energy impact is the worst. According to the emphasis given to each impact, designers will be able to choose one or the other. PMID:19368215

  5. Cathodic Protection of the Yaquina Bay Bridge

    Energy Technology Data Exchange (ETDEWEB)

    Bullard, Sophie J.; Cramer, Stephen D.; Covino, Bernard S., Jr.; Holcomb, Gordon R.; Russell, James H.; Laylor, H.M.; Cryer, C.B.

    2001-02-01

    The Yaquina Bay Bridge in Newport, Oregon, was designed by Conde B. McCullough and built in 1936. The 3,223-foot (982 m) structure is a combination of concrete arch approach spans and a steel through arch over the shipping channel. Cathodic protection is used to prevent corrosion damage to the concrete arches. The Oregon Department of Transportation (Oregon DOT) installed a carbon anode coating (DAC-85) on two of the north approach spans in 1985. This anode was operated at a current density of 6.6 mA/m2(0.6 mA/ft2). No failure of the conductive anode was observed in 1990, five years after application, or in 2000, 15 years after application. Thermal-sprayed zinc anodes 20 mils (0.5 mm) thick were applied to half the south approach spans beginning in 1990. Thermal-sprayed zinc anodes 15 mils (0.4 mm) thick were applied to the remaining spans in 1996. These anodes were operated at a current density of 2.2 mA/m2(0.2 mA/ft2). In 1999, four zones on the approach spans were included in a two-year field trial of humectants to improve zinc anode performance. The humectants LiNO3 and LiBr were applied to two zones; the two adjacent zones were left untreated as controls. The humectants substantially reduced circuit resistance compared to the controls.

  6. Stargate GTM: Bridging Descriptor and Activity Spaces.

    Science.gov (United States)

    Gaspar, Héléna A; Baskin, Igor I; Marcou, Gilles; Horvath, Dragos; Varnek, Alexandre

    2015-11-23

    Predicting the activity profile of a molecule or discovering structures possessing a specific activity profile are two important goals in chemoinformatics, which could be achieved by bridging activity and molecular descriptor spaces. In this paper, we introduce the "Stargate" version of the Generative Topographic Mapping approach (S-GTM) in which two different multidimensional spaces (e.g., structural descriptor space and activity space) are linked through a common 2D latent space. In the S-GTM algorithm, the manifolds are trained simultaneously in two initial spaces using the probabilities in the 2D latent space calculated as a weighted geometric mean of probability distributions in both spaces. S-GTM has the following interesting features: (1) activities are involved during the training procedure; therefore, the method is supervised, unlike conventional GTM; (2) using molecular descriptors of a given compound as input, the model predicts a whole activity profile, and (3) using an activity profile as input, areas populated by relevant chemical structures can be detected. To assess the performance of S-GTM prediction models, a descriptor space (ISIDA descriptors) of a set of 1325 GPCR ligands was related to a B-dimensional (B = 1 or 8) activity space corresponding to pKi values for eight different targets. S-GTM outperforms conventional GTM for individual activities and performs similarly to the Lasso multitask learning algorithm, although it is still slightly less accurate than the Random Forest method.

  7. Technology transfer — bridging space and society

    Science.gov (United States)

    Students of Technology Transfer Design Project Team (ISU Summer Session 1997)

    Strategies, policies and methods by which technologies can be cross-fertilized between the space and non-space sectors were examined by students of the design project "Technology Transfer — Bridging Space and Society". This project was undertaken by students attending the 1997 10th Anniversary Summer Session Program of the International Space University. General issues relating to transfer of technology were discussed including definitions and mechanisms (push, pull, interactive and pro-active). As well as looking at case studies and the impact of national policies on space agencies, the design project also sought to look at technology transfer on a country-by-country basis, selecting various countries for scrutiny and reporting on their technology transfer status. The project report shows how transfer of technology varies between nations and when analyzed with the case studies identifies the general strategies, policies and methods in use and how they can be improved. Finally, the report seeks to recommend certain issues to governments, space agencies and industrial organizations to facilitate the transfer of technology. These include the development of a generic metrics system and the implementation of better appropriate procedures and mechanisms for a positive diffusion process between space and non-space sectors.

  8. Bridging the Divide between Science and Journalism

    Directory of Open Access Journals (Sweden)

    Marincola Francesco M

    2010-03-01

    Full Text Available Abstract There are countless reasons nearly every scientist should learn how to communicate effectively with the media, including increased understanding of critical research findings to attract or sustain funding and build new professional partnerships that will further propel forward research. But where do scientists begin? Bridging the Divide between Science and Journalism offers practical tips for any scientist looking to work with the media. Given the traditional and internet-based sources for medical research and healthcare-related news now available, it is imperative that scientists know how to communicate their latest findings through the appropriate channels. The credible media channels are managed by working journalists, so learning how to package vast, technical research in a form that is appetizing and "bite-sized" in order to get their attention, is an art. Reducing years of research into a headline can be extremely difficult and certainly doesn't come naturally to every scientist, so this article provides suggestions on how to work with the media to communicate your findings.

  9. Model bridging chimera state and explosive synchronization

    Science.gov (United States)

    Zhang, Xiyun; Bi, Hongjie; Guan, Shuguang; Liu, Jinming; Liu, Zonghua

    2016-07-01

    Global synchronization and partial synchronization are the two distinctive forms of synchronization in coupled oscillators and have been well studied in recent decades. Recent attention on synchronization is focused on the chimera state (CS) and explosive synchronization (ES), but little attention has been paid to their relationship. Here we study this topic by presenting a model to bridge these two phenomena, which consists of two groups of coupled oscillators, and its coupling strength is adaptively controlled by a local order parameter. We find that this model displays either CS or ES in two limits. In between the two limits, this model exhibits both CS and ES, where CS can be observed for a fixed coupling strength and ES appears when the coupling is increased adiabatically. Moreover, we show both theoretically and numerically that there are a variety of CS basin patterns for the case of identical oscillators, depending on the distributions of both the initial order parameters and the initial average phases. This model suggests a way to easily observe CS, in contrast to other models having some (weak or strong) dependence on initial conditions.

  10. A p-quinodimethane-bridged porphyrin dimer.

    Science.gov (United States)

    Zeng, Wangdong; Ishida, Masatoshi; Lee, Sangsu; Sung, Young Mo; Zeng, Zebing; Ni, Yong; Chi, Chunyan; Kim, Dongho; Wu, Jishan

    2013-12-01

    A p-quinodimethane (p-QDM)-bridged porphyrin dimer 1 has been prepared for the first time. An unexpected Michael addition reaction took place when we attempted to synthesize compound 1 by reaction of the cross-conjugated keto-linked porphyrin dimers 8a and 8b with alkynyl/aryl Grignard reagents. Alternatively, compound 1 could be successfully prepared by intramolecular Friedel-Crafts alkylation of the diol-linked porphyrin dimer 14 with concomitant oxidation in air. Compound 1 shows intense one-photon absorption (OPA, λ(max)=955 nm, ε=45400 M(-1) cm(-1)) and a large two-photon absorption (TPA) cross-section (σ((2))(max)=2080 GM at 1800 nm) in the near-infrared (NIR) region due to its extended π-conjugation and quinoidal character. It also exhibits a short singlet excited-state lifetime of 25 ps. The cyclic voltammogram of 1 displays multiple redox waves with a small electrochemical energy gap of 0.86 eV. The ground-state geometry, electronic structure, and optical properties of 1 have been further studied by density functional theory (DFT) calculations and compared with those of the keto-linked dimer 8b. This research has revealed that incorporation of a p-QDM unit into the porphyrin framework had a significant impact on its optical and electronic properties, leading to a novel NIR OPA and TPA chromophore.

  11. Dynamic characteristics analysis of mats of ballasted track on bridge

    Directory of Open Access Journals (Sweden)

    Wu Kaiwei

    2012-11-01

    Full Text Available A complete vehicle-ballasted track-bridge coupling dynamic model is established. A program to analyze dynamic characteristics is also invented, which is the first time to systematically analyze the dynamic characteristics of vehicles, tracks and bridges when using mats under ballast on the rigid foundation of bridge, in China. The results show that:(1 The mats under ballast are able to reduce vibration of the train and the wheel-rail forces by a certain extent, which increase the comforts of passengers.(2 The mats under ballast are able to reduce the stress of ballast, which has a great practical significance on avoiding ballast powdering and reducing maintenance work of ballast. (3 The mats under ballast are able to reduce the vibration of bridges. It has a great significance on avoiding the lateral flow deformation of ballast under dynamic loads, keeping good track geometry to ensure the safety of operation.

  12. THE BRIDGE STRUCTURE TESTS UNDER SLOW MOVING LOAD

    Directory of Open Access Journals (Sweden)

    B. D. Sukhorukov

    2010-03-01

    Full Text Available Peculiarities and advantages of bridge structure tests under slow moving load are pointed out. The calculation algorithms for finding in-situ influence line ordinates based on the results of the tests are proposed.

  13. Bridging the Gap between Instructional Design and Double Loop Learning

    NARCIS (Netherlands)

    Spoelstra, Howard; Rusman, Ellen; Van Bruggen, Jan; Koper, Rob; Matera, Maristella

    2008-01-01

    Spoelstra, H., Rusman, E., Van Bruggen, J., Koper, R., & Matera, M. (2008). Bridging the Gap Between Instructional Design and Double-Loop Learning. International Journal of Web-Based Learning and Teaching Technologies, 3(1), 79-89.

  14. Abnormal oscillation modes in a waning light bridge

    CERN Document Server

    Yuan, Ding

    2016-01-01

    A sunspot acts as a waveguide in response to the dynamics of the solar interior; the trapped waves and oscillations could reveal its thermal and magnetic structures. We study the oscillations in a sunspot intruded by a light bridge, the details of the oscillations could reveal the fine structure of the magnetic topology. We use the Solar Dynamics Observatory/Atmospheric Imaging Assembly data to analyse the oscillations in the emission intensity of light bridge plasma at different temperatures and investigate their spatial distributions. The extreme ultraviolet emission intensity exhibits two persistent oscillations at five-minute and sub-minute ranges. The spatial distribution of the five-minute oscillation follows the spine of the bridge; whereas the sub-minute oscillations overlap with two flanks of the bridge. Moreover, the sub-minute oscillations are highly correlated in spatial domain, however, the oscillations at the eastern and western flanks are asymmetric with regard to the lag time. In the meanwhile...

  15. Re(I) bridged porphyrin dyads, triads and tetrads

    Indian Academy of Sciences (India)

    M Yedukondalu; M Ravikanth

    2011-03-01

    Porphyrin rings containing two meso-pyridyl groups either in cis or trans fashion can be used to construct Re(I) bridged multiporphyrin assemblies. The cis-dipyridyl porphyrins with various porphyrin cores such as N4, N3O, N3S, N2S2 have been used to react with Re(CO)5Cl in THF at refluxing temperature and constructed planar Re(I) bridged porphyrin dyads containing either one type of porphyrin subunit or two types of porphyrin subunits. The trans-dipyridyl porphyrins have been used to construct Re(I) bridged porphyrin squares. The porphyrin dyads have been explored for singlet-singlet energy transfer studies and porphyrin squares have been used for catalysis, chemical sensing, molecular sieving and photocurrent production studies. An overview of synthesis of Re(I) bridged porphyrin dyads, triads and tetrads and their interesting photophysical properties are highlighted in this paper.

  16. Segmental Bridges under Combined Torsion, Bending and Shear

    Institute of Scientific and Technical Information of China (English)

    黄真; 刘西拉

    2003-01-01

    Segmental bridges with unbonded prestressed tendons have some advantages, such as the weather independence and the corrosion protection of prestressing tendons. This paper analyzed the behavior of a prestressed segmental bridge with unbonded tendons under combined loading of torsion, bending and shear. According to the experiment research, a modified skew bending model was developed to calculate the bearing capacity of segmental bridges subjected to combined bending, shear and torsion. The finite element method was used to investigate the deflection behaviors of such structure, also to check the theoretical model. The theoretical and FEM research resuits were compared favorably with the test results from Technical University of Braunschweig, Germany. Finally, suggestion for the design and construction of segmental bridges with external prestressing was made.

  17. Effects of ice accretion on the aerodynamics of bridge cables

    DEFF Research Database (Denmark)

    Demartino, C.; Koss, Holger; Georgakis, Christos T.;

    2015-01-01

    Undesirable wind induced vibrations of bridge cables can occur when atmospheric conditions are such to generate ice accretion. This paper contains the results of an extensive investigation of the effects of ice accretion due to in-cloud icing, on the aerodynamic characteristics of bridge hangers...... of temperature, wind speed and yaw angle of accretion, were reproduced in a climatic wind tunnel, giving rise to different types of accretion. These were chosen such to generate the most common natural ice formations expected to produce bridge cable vibrations. A description of the geometric characteristics...... and stay cables. The aim of this paper is twofold; first, it was investigated the ice accretion process and the final shape of the ice accreted; then the aerodynamics of the ice accreted bridge cables was characterized, and related to the ice shape. Different climatic conditions, i.e. combinations...

  18. Bridge SHM system based on fiber optical sensing technology

    Science.gov (United States)

    Li, Sheng; Fan, Dian; Fu, Jiang-hua; Huang, Xing; Jiang, De-sheng

    2015-09-01

    The latest progress of our lab in recent 10 years on the area of bridge structural health monitoring (SHM) based on optical fiber sensing technology is introduced. Firstly, in the part of sensing technology, optical fiber force test-ring, optical fiber vibration sensor, optical fiber smart cable, optical fiber prestressing loss monitoring method and optical fiber continuous curve mode inspection system are developed, which not only rich the sensor types, but also provides new monitoring means that are needed for the bridge health monitoring system. Secondly, in the optical fiber sensing network and computer system platform, the monitoring system architecture model is designed to effectively meet the integration scale and effect requirement of engineering application, especially the bridge expert system proposed integration of sensing information and informatization manual inspection to realize the mode of multi index intelligence and practical monitoring, diagnosis and evaluation. Finally, the Jingyue bridge monitoring system as the representative, the research on the technology of engineering applications are given.

  19. Dynamics and stability of a vertical water bridge

    CERN Document Server

    Namin, Reza Montazeri

    2013-01-01

    A vertical connection of water is formed when a high voltage electrode is dipped in and pulled out of a container of deionized water. We considered the formation, stability and dynamical characteristics of this vertical water bridge. For the first time in this field, we observed instabilities in the bridge that led to an oscillatory behaviour which is categorized in three dynamical regimes and supplied explanations on the physics behind these varied motions. We report the formation of macroscopic droplets during this motion, which their dynamics revealed that they are electrically charged. In some cases the droplets would be levitating when the electric force opposes the gravity. Also the steady bridge is thoroughly studied regarding its geometry and a set of quantitative data is presented using dimensionless numbers, which brings the possibility of direct quantitative comparison between theory and experiments. Our results shed light on the physics behind this phenomenon and the horizontal water bridge, which...

  20. PS buildings : reinforced concrete structure for shielding "bridge" pillar

    CERN Multimedia

    CERN PhotoLab

    1956-01-01

    The PS ring traverses the region between the experimental halls South and North (buildings Nos 150 and 151) under massive bridge-shaped concrete beams. This pillar stands at the S-W end of the structure.