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. 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

  3. Living Waterways.

    Science.gov (United States)

    Hubbard, Guy

    2001-01-01

    Discusses the use of waterways as subjects in works of art. States that teachers can take their students to a river or canal to help them depict waterways. Explains that the four artworks reproduced in the article offer examples for students. Includes artwork by Franklin McMahon, Canaletto, Nancy Lagana, and Vincent van Gogh. (CMK)

  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......Andean Waterways explores the politics of natural resource use in the Peruvian Andes in the context of climate change and neoliberal expansion. It does so through careful ethnographic analysis of the constitution of waterways, illustrating how water becomes entangled in a variety of political...

  5. 33 CFR 117.451 - Gulf Intracoastal Waterway.

    Science.gov (United States)

    2010-07-01

    ... Waterway. (a) The draw of the Lapalco Boulevard Bridge, Harvey Canal Route, mile 2.8 at Harvey, shall open... 59.9 west of Harvey Lock, at Houma, shall open on signal; except that, the draw need not open for the... 319 (Louisa) bridge across the Gulf Intracoastal Waterway, mile 134.0 west of Harvey Lock,...

  6. 77 FR 44463 - Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC

    Science.gov (United States)

    2012-07-30

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone, Atlantic Intracoastal Waterway; Emerald... establishing a temporary safety zone on the waters of the Atlantic Intracoastal Waterway at Emerald Isle, North... maintenance of the NC 58 Fixed Bridge crossing the Atlantic Intracoastal Waterway, mile 226, at Emerald...

  7. 77 FR 1405 - Drawbridge Operation Regulation; Gulf Intracoastal Waterway, LA

    Science.gov (United States)

    2012-01-10

    ... Harvey Locks, at Grand Lake, Cameron Parish, Louisiana. The deviation is necessary to allow for the safe..., call or email David Frank, Bridge Administration Branch; telephone (504) 671-2128, email David.m.frank... Lake Pontoon Bridge across the Gulf Intracoastal Waterway, mile 231.5 west of Harvey Lock (WHL),...

  8. 77 FR 75556 - Drawbridge Operation Regulation; Gulf Intracoastal Waterway, Louisiana

    Science.gov (United States)

    2012-12-21

    ... Boulevard bascule span drawbridge across the Harvey Canal Route, Gulf Intracoastal Waterway (GIWW), mile 2.8... temporary deviation from the operating schedule for the Bascule Span Bridge across the Harvey Canal Route....35. Dated: December 5, 2012. David M. Frank, Bridge Administrator. BILLING CODE 9110-04-P...

  9. 78 FR 14185 - Drawbridge Operation Regulation; Gulf Intracoastal Waterway, LA

    Science.gov (United States)

    2013-03-05

    ... drawbridge across the Harvey Canal Route, Gulf Intracoastal Waterway (GIWW), mile 2.8 at New Orleans... the operating schedule for the Bascule Span Bridge across the Harvey Canal Route, Intracoastal..., 2013. David M. Frank, Bridge Administrator. BILLING CODE 9110-04-P...

  10. 77 FR 35903 - Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC

    Science.gov (United States)

    2012-06-15

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone, Atlantic Intracoastal Waterway; Emerald... Emerald Isle, North Carolina. The safety zone would temporarily restrict vessel movement. The safety zone... 58 Fixed Bridge crossing the Atlantic Intracoastal Waterway, mile 226, at Emerald Isle,...

  11. 75 FR 12688 - Drawbridge Operation Regulations; Long Island, New York Inland Waterway from East Rockaway Inlet...

    Science.gov (United States)

    2010-03-17

    ... Waterway from East Rockaway Inlet to Shinnecock Canal, NY, Maintenance AGENCY: Coast Guard, DHS. ACTION... to replace the motor locks at the bridge. The bridge can not open during the installation of the motor locks. Under this deviation the Wreck Lead Railroad Bridge may remain closed from 9 a.m. through...

  12. 76 FR 70345 - Drawbridge Operation Regulation; Gulf Intracoastal Waterway, LA

    Science.gov (United States)

    2011-11-14

    ... of the Lapalco Boulevard bascule span drawbridge across the Harvey Canal Route, Gulf Intracoastal Waterway (GIWW), mile 2.8 at Harvey, Jefferson Parish, Louisiana. The deviation is necessary to allow for... INFORMATION CONTACT: If you have questions on this rule, call or email David Frank, Bridge...

  13. 76 FR 40617 - Drawbridge Operation Regulation; Gulf Intracoastal Waterway, Near Hackberry, LA

    Science.gov (United States)

    2011-07-11

    ....8 west of Harvey Lock, near Hackberry, Calcasieu Parish, Louisiana. This deviation is necessary to... bridge on the SR 27 (Ellender Ferry) across the Gulf Intracoastal Waterway, mile 243.8, west of Harvey... CFR 117.35. Dated: June 20, 2011. David M. Frank, Bridge Administrator. BILLING CODE 9110-04-P...

  14. 78 FR 23488 - Drawbridge Operation Regulations; Atlantic Intracoastal Waterway, Albemarle and Chesapeake Canal...

    Science.gov (United States)

    2013-04-19

    ...The Coast Guard has issued a temporary deviation from the operating schedule that governs the SR 170 Centerville Turnpike Bridge, across the Atlantic Intracoastal Waterway, mile 15.2, Albemarle and Chesapeake Canal, at Chesapeake, VA. The deviation is necessary to facilitate structural repairs to the superstructure of the SR 170 Centerville Turnpike Draw Bridge. This temporary deviation will......

  15. 76 FR 70349 - Drawbridge Operation Regulation; Atlantic Intracoastal Waterway, Albemarle and Chesapeake Canal...

    Science.gov (United States)

    2011-11-14

    ...The Commander, Fifth Coast Guard District, has issued a temporary deviation from the regulations governing the operation of the S168 Bridge across the Atlantic Intracoastal Waterway, Albemarle and Chesapeake Canal, mile 12.0, at Chesapeake (Great Bridge), VA. This deviation is necessary to accommodate the annual Christmas parade...

  16. Waterways of Bangkok: Memory and Landscape

    OpenAIRE

    Hurley, Michael

    2015-01-01

    This is an ethnography of the Chao Phraya River in Bangkok, Thailand. It is about life along the river and its canals, the culture of water in a modern metropolis. More broadly, this is a study of the relationship between memory and landscape. Waterways, at the time of writing, are still an important part of Bangkok's urban infrastructure. I use waterways to explore collective memory. What meanings are found in waterways? How do waterways connect people and places? How do waterways connect pa...

  17. 76 FR 3516 - Drawbridge Operation Regulation; Gulf Intracoastal Waterway, Belle Chasse, LA

    Science.gov (United States)

    2011-01-20

    ...: If you have questions on this rule, call or e-mail David Frank, Bridge Administration Branch; telephone 504-671-2128, e-mail David.m.frank@uscg.mil . If you have questions on viewing the docket, call... the Gulf Intracoastal Waterway (Harvey Canal) to avoid unnecessary delays. The Coast Guard...

  18. 78 FR 6208 - Drawbridge Operating Regulations; Gulf Intracoastal Waterway, Belle Chasse, LA

    Science.gov (United States)

    2013-01-30

    ... have questions on this temporary deviation, call or email David Frank, Bridge Administration Branch, Coast Guard, telephone (504) 671-2128, email David.m.frank@uscg.mil . If you have questions on viewing... Gulf Intracoastal Waterway (Harvey Canal) to avoid unnecessary delays. The Coast Guard has...

  19. 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...

  20. 76 FR 27250 - Drawbridge Operation Regulation; Atlantic Intracoastal Waterway, Albemarle and Chesapeake Canal...

    Science.gov (United States)

    2011-05-11

    ...The Commander, Fifth Coast Guard District, has issued a temporary deviation from the regulations governing the operation of the SR170 Centerville Turnpike Bridge across the Atlantic Intracoastal Waterway, Albemarle and Chesapeake Canal, mile 15.2, at Chesapeake, VA. The deviation is necessary to facilitate urgent mechanical structural repairs to the swing span. Under this deviation, the......

  1. 33 CFR 117.820 - Atlantic Intracoastal Waterway (Alternate Route), Great Dismal Swamp Canal.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Atlantic Intracoastal Waterway (Alternate Route), Great Dismal Swamp Canal. 117.820 Section 117.820 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements North Carolina § 117.820...

  2. 75 FR 16004 - Drawbridge Operation Regulation; Atlantic Intracoastal Waterway, Albemarle and Chesapeake Canal...

    Science.gov (United States)

    2010-03-31

    ...The Commander, Fifth Coast Guard District, has issued a temporary deviation from the regulations governing the operation of the SR170 Centerville Turnpike Bridge across the Atlantic Intracoastal Waterway, Albemarle and Chesapeake Canal, mile 15.7, at Chesapeake, VA. The deviation is necessary to facilitate structural repairs to the swing span. This deviation allows the drawbridge to remain in......

  3. 75 FR 78601 - Drawbridge Operation Regulation; Gulf Intracoastal Waterway, New Orleans Harbor, Inner Harbor...

    Science.gov (United States)

    2010-12-16

    ... Orleans Harbor, Inner Harbor Navigation Canal, New Orleans, Orleans Parish, LA AGENCY: Coast Guard, DHS... Seeber/Claiborne Avenue) ] vertical lift bridge across the Inner Harbor Navigational Canal, mile 0.9, (Gulf Intracoastal Waterway mile 6.7 East of Harvey Lock), at New Orleans, Orleans Parish,...

  4. 76 FR 8653 - Drawbridge Operation Regulation; Gulf Intracoastal Waterway, New Orleans Harbor, Inner Harbor...

    Science.gov (United States)

    2011-02-15

    ... Orleans Harbor, Inner Harbor Navigation Canal, New Orleans, Orleans Parish, LA AGENCY: Coast Guard, DHS... Seeber/Claiborne Avenue) vertical lift bridge across the Inner Harbor Navigational Canal, mile 0.9, (Gulf Intracoastal Waterway mile 6.7 East of Harvey Lock), at New Orleans, Orleans Parish, Louisiana. This...

  5. 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...

  6. 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 District...

  7. 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 District...

  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. The 1992 Inland Waterway Review

    Science.gov (United States)

    1992-10-01

    waters. As a means of transportation, waterway vessels had a compelling advantage in moving goods 4 and people with the least effort. Over time, the...of nearly 38 million tons in 1988, then declined to 34.7 million tons in 1989 and 31.3 million tons in 1990. Agricultural chemicals, sensitive to...Starches, Gluten , Glue 4161 Wood Chips 3297 Chemical Additives 4170 Wood in the Rough 3298 Wood & Resin Chem. 4189 Lumber 3299 Chem. Products NEC 4190 Forest

  10. 75 FR 71543 - Safety Zone; Gulf Intracoastal Waterway, Mile Marker 49.0 to 50.0, west of Harvey Locks, Bank to...

    Science.gov (United States)

    2010-11-24

    ....0 to 50.0, west of Harvey Locks, Bank to Bank, Bayou Blue Pontoon Bridge, Lafourche Parish, LA..., bank to bank, West of Harvey Locks, Lafourche Parish, LA. This Safety Zone is needed to protect the... repairs of the Bayou Blue Pontoon Bridge, Mile Marker 49.8, Gulf Intracoastal Waterway, West of...

  11. 33 CFR 117.799 - Long Island, New York Inland Waterway from East Rockaway Inlet to Shinnecock Canal.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Long Island, New York Inland Waterway from East Rockaway Inlet to Shinnecock Canal. 117.799 Section 117.799 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.799 Long Island,...

  12. 76 FR 11216 - Inland Waterways Users Board

    Science.gov (United States)

    2011-03-01

    ....m. Agenda: The Board will be provided the status of the funding for inland navigation projects and studies and the status of the Inland Waterways Trust Fund, the funding status for Fiscal Year (FY)...

  13. 78 FR 44934 - Inland Waterways Users Board

    Science.gov (United States)

    2013-07-25

    ... approximately 1:00 p.m. Agenda: The agenda will include the status of funding for inland navigation projects and studies, the status of the Inland Waterways Trust Fund, funding for Fiscal Year (FY) 2013 and 2014,...

  14. 77 FR 44222 - Inland Waterways Users Board

    Science.gov (United States)

    2012-07-27

    ...:00 p.m. Agenda: The agenda will include the status of funding for inland navigation projects and studies and the status of the Inland Waterways Trust Fund, the funding status for Fiscal Year (FY)...

  15. 77 FR 69447 - Inland Waterways Users Board

    Science.gov (United States)

    2012-11-19

    ...:00 p.m. Agenda: The agenda will include the status of funding for inland navigation projects and studies and the status of the Inland Waterways Trust Fund, the funding status for Fiscal Year (FY)...

  16. 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...

  17. 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.

  18. 76 FR 12981 - Lower Mississippi River Waterway Safety Advisory Committee; Meeting

    Science.gov (United States)

    2011-03-09

    ... Warrant Officer David Chapman, Assistant to the DFO of Lower Mississippi River Waterway Safety Advisory... (RNA); Gulf Intracoastal Waterway, Inner Harbor Navigation Canal, Harvey Canal, Algiers Canal,...

  19. 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;...

  20. Methods of Calculating Ship Resistance on Limited Waterways

    Directory of Open Access Journals (Sweden)

    Skupień Emilia

    2015-01-01

    Full Text Available Nowadays predicting transportation costs is more and more important. Most significant part of inland navigation's costs are the costs of fuel. Fuel consumption is related to operating conditions of ship's propulsion system and its resistance. On inland waterways the ship resistance is strictly related to the depth of the waterway. There is a tendency to build a formula that allows its user to calculate the resistance of any inland waterway vessel, but researches claim that most of them are accurate only for particular types of ships and/or operating conditions. The paper presents selected methods of calculating ship resistance on inland waterways. These methods are examined for different types of ships and different conditions using results of model tests. The performed comparison enabled selecting the best option for pushboats and pushed barge trains, but also showed that any of the tested methods is good enough to be used for calculating the resistance of motor cargo vessels. For this reason, based on known equations and using the regression method, the authors have formulated a new method to calculate the resistance of motor cargo vessels on limited waterway. The method makes use of ship's geometry and depth of waterway in relation to ship's speed. Correlating the ship's speed with its resistance and going further with fuel consumption, enables to calculate the costs of voyage depending on the delivery time. The comparison of the methods shows that the new equation provides good accuracy in all examined speed ranges and all examined waterway depths.

  1. 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...

  2. 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.

  3. 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...

  4. 33 CFR 165.806 - Sabine Neches Waterway, Texas-regulated navigation area.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Sabine Neches Waterway, Texas... § 165.806 Sabine Neches Waterway, Texas—regulated navigation area. (a) The following is a regulated navigation area—The Sabine Neches Waterway which includes the following waters: Sabine Pass Channel,...

  5. 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

  6. 77 FR 22769 - Amendment to the Inland Waterways Users Board

    Science.gov (United States)

    2012-04-17

    ... and rehabilitation priorities and spending levels on the commercial navigation features and components... users and shippers invited to serve on the Board shall designate an individual to represent the... Inland Waterways Users Board, and this individual will ensure that the written statements are provided...

  7. 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.

  8. 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....

  9. A cellular automaton model for ship traffic flow in waterways

    Science.gov (United States)

    Qi, Le; Zheng, Zhongyi; Gang, Longhui

    2017-04-01

    With the development of marine traffic, waterways become congested and more complicated traffic phenomena in ship traffic flow are observed. It is important and necessary to build a ship traffic flow model based on cellular automata (CAs) to study the phenomena and improve marine transportation efficiency and safety. Spatial discretization rules for waterways and update rules for ship movement are two important issues that are very different from vehicle traffic. To solve these issues, a CA model for ship traffic flow, called a spatial-logical mapping (SLM) model, is presented. In this model, the spatial discretization rules are improved by adding a mapping rule. And the dynamic ship domain model is considered in the update rules to describe ships' interaction more exactly. Take the ship traffic flow in the Singapore Strait for example, some simulations were carried out and compared. The simulations show that the SLM model could avoid ship pseudo lane-change efficiently, which is caused by traditional spatial discretization rules. The ship velocity change in the SLM model is consistent with the measured data. At finally, from the fundamental diagram, the relationship between traffic ability and the lengths of ships is explored. The number of ships in the waterway declines when the proportion of large ships increases.

  10. 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,...

  11. 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

    ... Johnston Waterway (Red River) AGENCY: Department of the Army, U.S. Army Corps of Engineers, DoD. ACTION... Dam on the J Bennett Johnston Waterway will remain at the current schedule of 24 hours per day, 7...

  12. 76 FR 38011 - Safety Zone; Hylebos Bridge Restoration, Hylebos Waterway, Tacoma, WA

    Science.gov (United States)

    2011-06-29

    ... bases this finding on the fact that the safety zone is small in size, short in duration, and maritime traffic will be able to transit this area during times when the zone is not enforced. Maritime traffic may also request permission to transit through the zone from the Captain of the Port, Puget Sound...

  13. 77 FR 19937 - Drawbridge Operation Regulation; Mile 21.6, Illinois Waterway, Hardin, IL

    Science.gov (United States)

    2012-04-03

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulation; Mile 21.6, Illinois Waterway, Hardin... Coast Guard has issued a temporary deviation from the operating schedule that governs the Hardin Drawbridge across the Illinois Waterway, mile 21.6, at Hardin, Illinois. The deviation is necessary...

  14. 75 FR 66306 - Drawbridge Operation Regulation; Arkansas Waterway, Little Rock, AR

    Science.gov (United States)

    2010-10-28

    ..., Little Rock, AR AGENCY: Coast Guard, DHS. ACTION: Final rule. SUMMARY: Drawbridge operations for the Baring Cross Railroad Drawbridge across the Arkansas Waterway at Mile 119.6 at Little Rock, Arkansas... (NPRM) entitled Drawbridge Operation Regulation; Arkansas Waterway, Little ] Rock, AR in the...

  15. 33 CFR 209.180 - Temporary closure of waterway to navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Temporary closure of waterway to navigation. 209.180 Section 209.180 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE... navigation. (a) When an application is received for the temporary closure of a waterway for the...

  16. 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,...

  17. 77 FR 57063 - Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC

    Science.gov (United States)

    2012-09-17

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone, Atlantic Intracoastal Waterway; Emerald... proposes to extend a temporary safety zone on the waters of the Atlantic Intracoastal Waterway at Emerald..., at Emerald Isle, North Carolina. The safety zone extension would temporarily restrict vessel...

  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. 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...... Belgrade), Leo Pekkala (Finnish Centre for Media Education and Audiovisual Media/MEKU), Julie Uldam (Network on Civic Engagement and Social Innovation) and Gabriella Velics (Community Media Forum Europe)....

  20. Mathematical bridges

    CERN Document Server

    Andreescu, Titu; Tetiva, Marian

    2017-01-01

    Building bridges between classical results and contemporary nonstandard problems, Mathematical Bridges embraces important topics in analysis and algebra from a problem-solving perspective. Blending old and new techniques, tactics and strategies used in solving challenging mathematical problems, readers will discover numerous genuine mathematical gems throughout that will heighten their appreciation of the inherent beauty of mathematics. Most of the problems are original to the authors and are intertwined in a well-motivated exposition driven by representative examples. The book is structured to assist the reader in formulating and proving conjectures, as well as devising solutions to important mathematical problems by making connections between various concepts and ideas from different areas of mathematics. Instructors and educators teaching problem-solving courses or organizing mathematics clubs, as well as motivated mathematics students from high school juniors to college seniors, will find Mathematical Bri...

  1. Plastic Bridge

    Institute of Scientific and Technical Information of China (English)

    履之

    1994-01-01

    Already ubiquitous in homes and cars, plastic is now appearing inbridges. An academic-industrial consortium based at the University ofCalifornia in San Diego is launching a three-year research program aimed atdeveloping the world’s first plastic highway bridge, a 450-foot span madeentirely from glass-,carbon,and polymer-fiber-reinforced composite mate-rials, the stuff of military aircraft. It will cross Interstate 5 to connect thetwo sides of the school’s campus.

  2. 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

  3. Rehabilitation options for inland waterways impacted by sulfidic sediments--a synthesis.

    Science.gov (United States)

    Baldwin, Darren S; Fraser, Mark

    2009-01-01

    The build up of reduced inorganic sulfur in the sediments of inland wetlands and creeks is an emerging risk for the management of inland waterways and is a direct result of secondary salinisation. Inappropriate management of these sediments can lead to a number of adverse environmental outcomes, the most dramatic of which is the extreme acidification of inland waterways, but can also include deoxygenation and the release of heavy metals. This paper explores possible management options for reducing the impact of sulfidic sediments on inland waterways based on previous research into ameliorating the impact of acid mine and acid rock drainage and coastal acid sulfate soils. The main strategies explored include minimising the formation of sulfidic sediments in the first instance, rehabilitation of impacted waterways, or isolation of the water body from the surrounding environment.

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

    OpenAIRE

    Sulaiman M. Yassin; Hayrol A.M. Shaffril; Md. S. Hassan; Mohd S. Othman; Asnarulkhadi A. Samah; Bahaman A. Samah

    2010-01-01

    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 ...

  5. 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.

  6. 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...

  7. 77 FR 32393 - Drawbridge Operation Regulation; Gulf Intracoastal Waterway, LA

    Science.gov (United States)

    2012-06-01

    ... the Lapalco Boulevard bascule span drawbridge across the Harvey Canal Route, Gulf Intracoastal... Federal holidays. FOR FURTHER INFORMATION CONTACT: If you have questions on this rule, call or email David Frank, Bridge Branch Office, Coast Guard; telephone 504-671-2128, email David.M.Frank@uscg.mil . If...

  8. Sediment contamination and associates laboratory-measured bioaccumulation in New York/New Jersey waterways

    Energy Technology Data Exchange (ETDEWEB)

    Rosman, L.B. [Army Corps of Engineers, New York, NY (United States); Barrows, E.S. [Battelle/Marine Sciences Lab., Sequim, WA (United States)

    1995-12-31

    Sediments from 10 New York/New Jersey waterways within the Hudson-Raritan Estuary and Long Island Sound were collected to depths representative of dredging activity. Composited core sediments representing each waterway were analyzed for metals, PAHs, PCBs, and pesticides. To assess bioaccumulation, sand worms (Nereis virens) and blunt-nose clams (Macoma nasuta) were exposed for 28 days to sediment composites and to New York Bight sediment. Tissues were analyzed for the same constituents as the sediment samples. The results highlight the range and magnitude of sediment contamination in NY/NJ waterways. Concentrations of some metals in sediments, compared with NY Bight sediment, were at least 10 times higher. Total PAHs reached 30,000 {micro}g/kg (dry weight). The sum of DDT, DDD, and DDE, the dominant pesticides, exceeded 3,000{micro}g/kg (dry weight). Total PCBs approached 3,000 {micro}g/kg (dry weight). Tissues exposed to sediments from several waterways bioaccumulated organic compounds at concentrations 10 times greater than those exposed to New York Bight sediments. Metals were bioaccumulated to a lesser degree. The presence and extent of bioaccumulated contaminants, along with sediment chemistry and benthic toxicity, create a profile characterizing each waterway.

  9. Water-quality sampling plan for evaluating the distribution of bigheaded carps in the Illinois Waterway

    Science.gov (United States)

    Duncker, James J.; Terrio, Paul J.

    2017-02-27

    The two nonnative invasive bigheaded carp species (bighead carp Hypophthalmichthys nobilis and silver carp H. molitrix) that were accidentally released in the 1970s have spread widely into the rivers and waterways of the Mississippi River Basin. First detected in the lower reaches of the Illinois Waterway (IWW, the combined Illinois River-Des Plaines River-Chicago Area Waterway System) in the 1990s, bighead and silver carps moved quickly upstream, approaching the Chicago Area Waterway System. The potential of substantial negative ecological and economic impact to the Great Lakes from the presence of these species is a concern. However, since 2006, the population front of bigheaded carps has remained in the vicinity of Joliet, Illinois, near river mile 278. This reach of the IWW is characterized by stark changes in habitat, water quality, and food resources as the waterway transitions from a primarily agricultural landscape to a metropolitan and industrial canal system. This report describes a 2015 plan for sampling the IWW to establish water-quality conditions that might be contributing to the apparent stalling of the population front of bigheaded carps in this reach. A detailed description of the study plan, Lagrangian-style sampling approach, selected analytes, sampling methods and protocols are provided. Hydrographs from streamflow-gaging stations show IWW conditions during the 2015 sampling runs.

  10. 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...

  11. 33 CFR 207.160 - All waterways tributary to the Atlantic Ocean south of Chesapeake Bay and all waterways tributary...

    Science.gov (United States)

    2010-07-01

    ..., bridges, piers, fences, trees, houses, shops or any other property of the United States pertaining to the..., house boats or like craft shall be expedited by locking them through with commercial craft (other than... by written permit from the District Engineer. (8) The building, assembling, or breaking up of a...

  12. Bridges in Complex Networks

    CERN Document Server

    Wu, Ang-Kun; Liu, Yang-Yu

    2016-01-01

    A bridge in a graph is an edge whose removal disconnects the graph and increases the number of connected components. We calculate the fraction of bridges in a wide range of real-world networks and their randomized counterparts. We find that real networks typically have more bridges than their completely randomized counterparts, but very similar fraction of bridges as their degree-preserving randomizations. We define a new edge centrality measure, called bridgeness, to differentiate the importance of a bridge in damaging a network. We find that certain real networks have very large average and variance of bridgeness compared to their degree-preserving randomizations and other real networks. Finally, we offer an analytical framework to calculate the bridge fraction and average bridgeness for uncorrelated random networks with arbitrary degree distributions.

  13. Dissolved Mn Speciation and Ligand Characteristics in a Coastal Waterway

    Science.gov (United States)

    Oldham, V.; Jensen, L.; Luther, G. W., III

    2014-12-01

    Soluble manganese speciation (Mn(II) and Mn(III); 0.2 μm filtered) was measured along a salinity gradient in the Broadkill River, a coastal waterway bordered by wetlands and salt marshes in Delaware. We modified an established method of porphyrin (T-4(CP)P) addition, by incorporating a heating step and coupling a 100-cm cell to a UV/Vis detector, to achieve a 4.0 nM sample DL. Surface waters were collected from June to August, 2014 and total dissolved Mn (0.23 - 1.92 μM) first increased then decreased along the salinity gradient (31 ppt to freshwater). However, Mn speciation was highly variable; Mn(III) made up 0-49 % of the total dissolved Mn, where the highest Mn(III) values occurred at sites with high salt-marsh runoff. Mn(III) was not recoverable without the addition of a strong reducing agent, indicating that little or no weak ligand was present, and that a strong ligand was responsible for complexing Mn(III). An assessment of potential strong ligand character was made by precipitating humic matter, by acidifying subsamples to pHyellow color. Upon the addition of 500 μM desferrioxamine-B (DFOB) to the same sample, a peak at 310 nm appeared, indicating the formation of Mn(III)-DFOB. In acidified samples, the Mn(III)-pyrophosphate peak did not change. Humic matter, therefore, may be acting as an Mn(III) binding ligand, outcompeting pyrophosphate for Mn(III), however this natural ligand is outcompeted by a large excess of DFOB. The humic matter and increased Mn likely come from the salt marsh runoff during tidal exchange, and we observed that as salinity increased, the amount of humic binding decreased. These results present the first Mn speciation measurements along a salinity gradient in oxygenated waters.

  14. Planning large systems with MDPs: case study of inland waterways supervision

    Directory of Open Access Journals (Sweden)

    Guillaume DESQUESNES

    2016-12-01

    Full Text Available Inland waterway management is likely to go through heavy changes due to an expected traffic increase in a context of climate change. Those changes will require an adaptive and resilient management of the water resource. The aim is to have an optimal plan for the distribution of the water resource on the whole inland waterway network, while taking into account the uncertainties arising from the operations of such a network. A representative model using Markov decision processes is proposed to model the dynamic and the uncertainties of the waterways. The proposed model is able to coordinate multiple entities over multiple time steps in order to prevent an overflow of a test network. However, this model suffers from a lack of scalability and is unable to represent real case applications. Advantages and limitations of several approaches of the literature to circumvent this limitation are discussed according to our case study.

  15. 75 FR 30753 - Regulated Navigation Area; Thea Foss and Wheeler-Osgood Waterways EPA Superfund Cleanup Site...

    Science.gov (United States)

    2010-06-02

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA11 Regulated Navigation Area; Thea Foss and Wheeler-Osgood... and Wheeler-Osgood Waterways in Commencement Bay, Tacoma, Washington. The RNA would protect the seabed... rulemaking (NPRM) entitled ``Regulated Navigation Area; Thea Foss and Wheeler-Osgood Waterways...

  16. 78 FR 34083 - Proposed Reductions in Levels of Service at Locks and Dams on the J Bennett Johnston Waterway...

    Science.gov (United States)

    2013-06-06

    ... John H. Overton Locks on the J Bennett Johnston Waterway (Red River) will remain at the current... J Bennett Johnston Waterway (Red River) AGENCY: Department of the Army, U.S. Army Corps of Engineers... availability at Lock 3, Russell B. Long, and Joe D. Waggonner locks will be reduced from the current...

  17. 76 FR 36314 - Safety Zone; Mile Marker 98.5 West of Harvey Lock Gulf Intracoastal Waterway to Mile Marker 108.5...

    Science.gov (United States)

    2011-06-22

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Mile Marker 98.5 West of Harvey Lock Gulf Intracoastal Waterway to Mile Marker 108.5 West of Harvey Lock Gulf Intracoastal Waterway AGENCY: Coast Guard... imposing restrictions on the Gulf Intracoastal Waterway (GIWW) between West Harvey Lock Gulf West...

  18. 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.

  19. 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.

  20. 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,

  1. A Multi-Agent System for Tracking the Intent of Surface Contacts in Ports and Waterways

    Science.gov (United States)

    2005-03-01

    identify asymmetric maritime threats in port and waterways. Each surface track is monitored by a compound multi - agent system that comprise of the several...intent models, each containing a nested multi - agent system . The attributes that define intent models of friendly, neutral, unknown and potentially

  2. 75 FR 30750 - Drawbridge Operation Regulation; Arkansas Waterway, Little Rock, AR

    Science.gov (United States)

    2010-06-02

    ..., Little Rock, AR AGENCY: Coast Guard, DHS. ACTION: Notice of proposed rulemaking. SUMMARY: The Coast Guard... Waterway at mile 119.6 at Little Rock, AR, so that vessel operators will contact the remote drawbridge... the Baring Cross Railroad Drawbridge, mile 119.6, at Little Rock, AR is maintained in the...

  3. Waterborne Commerce of the United States, Calendar Year 1980. Part 1. Waterways and Harbors, Atlantic Coast.

    Science.gov (United States)

    1982-09-01

    Canada, the esport statistics reflect fully compiled data for shipments named $1,000 and over combined with estimated data for shipments valted $251-$999...Rivers, Federal and Private Canals, Connecting Channels, and Intracoastal Waterways The terms "imports." " esports ." "coastwise receipts," "coastwise

  4. 78 FR 38672 - Ocean Dumping; Sabine-Neches Waterway (SNWW) Ocean Dredged Material Disposal Site Designation

    Science.gov (United States)

    2013-06-27

    ... AGENCY 40 CFR Part 228 Ocean Dumping; Sabine-Neches Waterway (SNWW) Ocean Dredged Material Disposal Site... Entities B. Background C. Disposal Volume Limit D. Site Management and Monitoring Plan E. Ocean Dumping.... Ocean Dumping Site Designation Criteria In proposing to designate these Sites, the EPA assessed...

  5. 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

  6. The effects of the internal flow structure on SPM entrapment in the Rotterdam Waterway

    NARCIS (Netherlands)

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

    2010-01-01

    Field measurements are presented, which are the first to quantify the processes influencing the entrapment of suspended particulate matter (SPM) at the limit of saltwater intrusion in the Rotterdam Waterway. The estuarine turbidity maximum (ETM) is shown to be maintained by the trapping of fluvial S

  7. Soot concentrations along busy inland waterways in the Netherlands; Roetconcentraties langs drukke binnenvaarwegen in Nederland

    Energy Technology Data Exchange (ETDEWEB)

    Keuken, M.; Jonkers, S.; Moerman, M. [TNO Built Environment and Geosciences, Delft (Netherlands); Hoek, G. [Institute for Risk Assessment Sciences IRAS, Utrecht University, Utrecht (Netherlands)

    2013-08-15

    Exploratory research by TNO and IRAS shows that residents in the Netherlands are exposed to soot concentrations along busy inland waterways similar to living along a busy highway [Dutch] Verkennend onderzoek van TNO en IRAS laat zien dat bewoners langs drukke binnenvaarwegen worden blootgesteld aan roetconcentraties vergelijkbaar met wonen langs een drukke snelweg.

  8. Vessel traffic safety in busy waterways: A case study of accidents in western shenzhen port.

    Science.gov (United States)

    Mou, J M; Chen, P F; He, Y X; Yip, Tsz Leung; Li, W H; Tang, J; Zhang, H Z

    2016-08-03

    Throughout the world, busy waterways near large ports witness heavy vessel traffic in recent decades. The waterways are characterized by high risk in terms of loss of life, property, and pollution to environment. To facilitate maritime safety management with satisfactory efficiency and efficacy, the authors propose a framework of safety indexes to evaluate the risk level in busy waterways according to the accident severity, fatality rate and special indicators of maritime transportation. The safety indexes consist of Safety Evaluation Index (SEI) and Safety Warning Index (SWI), and are derived from the proposed risk criteria of Chinese vessel traffic. As a case study, data on vessel traffic accidents reported in the Western Shenzhen Port, South China from 1995 to 2015 are analyzed. The actual risk level of this area during the period is calculated under the framework. The implementation of the safety indexes indicate that the risk criteria and safety indexes are practicable and effective for the vessel traffic management. The methodology based on long-term accident data can significantly support the risk analysis in the macroscopic perspective for busy ports and waterways, such that SWI can act as threshold to trigger actions, while SEI can act as an indicator to measure safety status.

  9. 78 FR 26056 - Waterway Suitability Assessment for Expansion of Liquefied Gas Terminals; Nederland, TX

    Science.gov (United States)

    2013-05-03

    ... SECURITY Coast Guard Waterway Suitability Assessment for Expansion of Liquefied Gas Terminals; Nederland... proposed expansion of its Liquefied Hazardous Gas (LHG) facility in Nederland, Texas, and increased LHG... solicit public comments on the proposed increase in LHG marine traffic in Nederland, Texas....

  10. 77 FR 64906 - Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC

    Science.gov (United States)

    2012-10-24

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone, Atlantic Intracoastal Waterway; Emerald... Emerald Isle, North Carolina. The safety zone is necessary to provide for the safety of mariners on..., mile 226, at Emerald Isle, North Carolina. The safety zone extension will temporarily restrict...

  11. 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...

  12. 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... Waterway in Myrtle Beach, South Carolina during the Myrtle Beach Triathlon. The Myrtle Beach Triathlon, which is comprised of a series of triathlon races, is scheduled to take place on Saturday, October...

  13. 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... Waterway in Myrtle Beach, South Carolina during the Myrtle Beach Triathlon. The Myrtle Beach Triathlon, which is comprised of a series of triathlon races, is scheduled to take place on Saturday, October...

  14. 78 FR 2916 - Special Local Regulation; West Palm Beach Triathlon Championship, Intracoastal Waterway, West...

    Science.gov (United States)

    2013-01-15

    ... SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AA08 Special Local Regulation; West Palm Beach Triathlon... Intracoastal Waterway, in West Palm Beach, Florida, during the West Palm Beach Triathlon Championship, on Saturday, June 1, 2013. Approximately 1,500 participants are anticipated to participate in the...

  15. 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.

  16. 77 FR 22216 - Drawbridge Operation Regulations; Atlantic Intracoastal Waterway, Fort Lauderdale, FL

    Science.gov (United States)

    2012-04-13

    ... Olas Bridge, mile 1064. The deviations are necessary due to the high volume of vessel and vehicle... to the operating schedules of the East Sunrise Boulevard (SR 838) Bridge and the East Las Olas Bridge... from 9:45 p.m. to 10:45 p.m. 2. East Las Olas Bridge, mile 1064. The vertical clearance of the East...

  17. Sustainable Bridge Infrastructure Procurement

    DEFF Research Database (Denmark)

    Safi, Mohammed; Du, Guangli; Simonsson, Peter

    2016-01-01

    The lack of a flexible but systematic approach for integrating lifecycle aspects into bridge investment decisions is a major obstacle hindering the procurement of sustainable bridge infrastructures. This paper addresses this obstacle by introducing a holistic approach that agencies could use...... to procure the most “sustainable” (lifecycle-efficient) bridge through a fair design-build (D-B) tendering process, considering all the main aspects: life-cycle cost (LCC), service life-span, aesthetic demands and environmental impacts (LCA)....

  18. Bridge Crossing Simulator

    Science.gov (United States)

    2014-10-07

    Requirement BCS Computer-controlled hydraulic actuation system to impart simulated crossing loads on an entire bridge structure undergoing fatigue test ...structure. Bridge test site with prepared embankments corresponding to the span and bank condition requirements of the bridge under test Conduct real...Center (AEC). (5) Sample size and number of crossings required. The number of required simulated crossings to conduct fatigue testing per the

  19. 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...

  20. 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....

  1. 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.

  2. 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...

  3. 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...

  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. 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.

  6. Waterborne Commerce of the United States Calendar Year 1987. Part 1. Waterways and Harbors Atlantic Coast

    Science.gov (United States)

    1989-05-31

    CO4FARATIVE STATEMENT OF TRAFFIC -- F AUDITIONAL TRAFFIC - ! ADOITIDN&].TRAFFIC T.7OUGH &t/1TO11D:ILE THR UG YEA9 TONS PASSENGER5 TAVFFIc ACCOMPANYIjG )EAR...AND DRAFTS OF VESSELS HARBOR OR WATERWAY DIRECTION DIRECTION SrLF PROPELLED VESSELS PFE -ROELFSP*OPfLLCONtO.SELF SOPEL ED SELF PSOPELLE[O V[$SELS VESSELS

  7. Report of the Inland Waterway Transport (IWT) Mission, 5 February-20 April 1985. Appendices

    Science.gov (United States)

    1985-06-01

    area is entirely different from the main river as regards to river transportation. In the Delta, intricate waterways with sharp bends have to be...biggest carrying capacity would be for a composite wood- GRP structure. 6. Traffic Currently, the canals are performing a very minor transport function. 7...appropriate station. The canal is 25 km in length. The water from the pumping station is distilled before being distributed to water pipes all over

  8. 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.

  9. Monitoring of metal pollution in waterways across Bangladesh and ecological and public health implications of pollution.

    Science.gov (United States)

    Kibria, Golam; Hossain, Md Maruf; Mallick, Debbrota; Lau, T C; Wu, Rudolf

    2016-12-01

    Using innovative artificial mussels technology for the first time, this study detected eight heavy metals (Cd, Cu, Fe, Mn, Ni, Pb, U, Zn) on a regular basis in waterways across Bangladesh (Chittagong, Dhaka and Khulna). Three heavy metals, viz. Co, Cr and Hg were always below the instrumental detection levels in all the sites during the study period. Through this study, seven metal pollution "hot spots" have been identified, of which, five "hot spots" (Cu, Fe, Mn, Ni, Pb) were located in the Buriganga River, close to the capital Dhaka. Based on this study, the Buriganga River can be classified as the most polluted waterway in Bangladesh compared to waterways monitored in Khulna and Chittagong. Direct effluents discharged from tanneries, textiles are, most likely, reasons for elevated concentrations of heavy metals in the Buriganga River. In other areas (Khulna), agriculture and fish farming effluents may have caused higher Cu, U and Zn in the Bhairab and Rupsa Rivers, whereas untreated industrial discharge and ship breaking activities can be linked to elevated Cd in the coastal sites (Chittagong). Metal pollution may cause significant impacts on water quality (irrigation, drinking), aquatic biodiversity (lethal and sub-lethal effects), food contamination/food security (bioaccumulation of metals in crops and seafood), human health (diseases) and livelihoods of people associated with wetlands.

  10. 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.

  11. 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

  12. 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...

  13. Bridging Humanism and Behaviorism.

    Science.gov (United States)

    Chu, Lily

    1980-01-01

    Humanistic behaviorism may provide the necessary bridge between behaviorism and humanism. Perhaps the most humanistic approach to teaching is to learn how certain changes will help students and how these changes can be accomplished. (Author/MLF)

  14. Germ Cell Intercellular Bridges

    Science.gov (United States)

    Greenbaum, Michael P.; Iwamori, Tokuko; Buchold, Gregory M.; Matzuk, Martin M.

    2011-01-01

    Stable intercellular bridges are a conserved feature of gametogenesis in multicellular animals observed more than 100 years ago, but their function was unknown. Many of the components necessary for this structure have been identified through the study of cytokinesis in Drosophila; however, mammalian intercellular bridges have distinct properties from those of insects. Mammalian germ cell intercellular bridges are composed of general cytokinesis components with additional germ cell–specific factors including TEX14. TEX14 is an inactive kinase essential for the maintenance of stable intercellular bridges in gametes of both sexes but whose loss specifically impairs male meiosis. TEX14 acts to impede the terminal steps of abscission by competing for essential component CEP55, blocking its interaction in nongerm cells with ALIX and TSG101. Additionally, TEX14-interacting protein RBM44, whose localization in stabile intercellular bridges is limited to pachytene and secondary spermatocytes, may participate in processes such as RNA transport but is nonessential to the maintenance of intercellular bridge stability. PMID:21669984

  15. 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 Europe...... is found in Scandinavia - the 1210 m span of the Höga Kusten Bridge in Sweden.The Kvarnsund Bridge in Norway was at the completion in 1991 the longest cable-stayed bridge in the world, and the span of 530 m is still thge longest for cable-stayed bridges in concrete. The Øresund Bridge with its sapn of 490...... m is the longest among cable-stayed bridges for both road and railway traffic....

  16. Cost Control of the Waterway Project%航道工程项目的成本控制研究

    Institute of Scientific and Technical Information of China (English)

    赵志刚

    2012-01-01

    As infrastructure of water transport, the cost control of waterway project is a very important work. Only establishing a reasonable cost control plan, can we improve the social and economic benefit of waterway engineering and achieve the greatest benefit of the national economy. This article analyzed the cost control of waterway engineering and its importance, identified current unreasonable aspect of waterway engineering cost control, thrown out the main cause of the problems, and put forward measures to improve the rationality of waterway engineering cost control plan.%作为水运的基础设施,航道工程项目的成本控制是一项非常重要的工作,只有制定合理的成本控制计划,才能够提高航道工程的社会利益和经济效益,才能为国民经济谋求最大的效益.本文通过对航道工程成本控制及其重要性进行分析,找出目前工程成本控制方面存在的不合理之处,摸索出引发问题的主要原因,最后提出提高航道工程成本控制计划合理性的措施.

  17. Spatial distribution of PAHs and associated laboratory-measured bioaccumulation in New York/New Jersey waterways

    Energy Technology Data Exchange (ETDEWEB)

    Rosman, L.B. [Army Corps of Engineers, New York, NY (United States); Barrows, E.S. [Battelle/Marine Sciences Lab., Sequim, WA (United States)

    1995-12-31

    Sediment core samples from New York/New Jersey waterways within the Hudson-Raritan Estuary and Long Island Sound were collected to depths representative of dredging activity. Sediment was also collected from a reference site in the New York Bight as a comparison. Composited core sediments representing each waterway were analyzed for PAHs, sediment grain size, and total organic carbon. To assess bioaccumulation, sand worms (Nereis virens) and blunt-nose clams (Macoma nasuta) were exposed for 28 days to sediment composites and to New York Bight sediment. Tissues were analyzed for the same constituents as the sediment samples, as well as for lipid content. The results highlight the range and magnitude of PAH concentrations in sediments of NY/NJ waterways. Concentrations of total PAHs ranged from undetected to 30,000 {micro}g/kg (dry weight). Tissues exposed to sediments from several waterways bioaccumulated organic compounds at concentrations as much as 10 times greater than those exposed to New York Bight sediments. The presence and extent of bioaccumulated compounds, along with benthic toxicity data, create a profile characterizing each waterway.

  18. The influence of hydrology and waterway distance on population structure of Chinook salmon Oncorhynchus tshawytscha in a large river.

    Science.gov (United States)

    Olsen, J B; Beacham, T D; Wetklo, M; Seeb, L W; Smith, C T; Flannery, B G; Wenburg, J K

    2010-04-01

    Adult Chinook salmon Oncorhynchus tshawytscha navigate in river systems using olfactory cues that may be influenced by hydrologic factors such as flow and the number, size and spatial distribution of tributaries. Thus, river hydrology may influence both homing success and the level of straying (gene flow), which in turn influences population structure. In this study, two methods of multivariate analysis were used to examine the extent to which four indicators of hydrology and waterway distance explained population structure of O. tshawytscha in the Yukon River. A partial Mantel test showed that the indicators of hydrology were positively associated with broad-scale (Yukon basin) population structure, when controlling for the influence of waterway distance. Multivariate multiple regression showed that waterway distance, supplemented with the number and flow of major drainage basins, explained more variation in broad-scale population structure than any single indicator. At an intermediate spatial scale, indicators of hydrology did not appear to influence population structure after accounting for waterway distance. These results suggest that habitat changes in the Yukon River, which alter hydrology, may influence the basin-wide pattern of population structure in O. tshawytscha. Further research is warranted on the role of hydrology in concert with waterway distance in influencing population structure in Pacific salmon.

  19. The aesthetic composite bridge.

    Science.gov (United States)

    Feinman, R A

    1997-01-01

    New developments are constantly introduced in the search for the optimal treatment modality to restore a single anterior tooth. The patient attention has shifted to aesthetics of the restoration, biocompatibility of the dental materials utilized, conservative preparation of the teeth to be restored, and the retention of intact adjacent dentition. The learning objective of this article is to review the methods currently utilized and to present a recently introduced treatment modality--the two-component bridge, which combines the strength and resiliency of composite resin with the aesthetic advantages of porcelain. The technology of the material is reviewed, the predominantly lingual tooth preparation procedures are outlined, and the bridge try-in is described. The advantages of the two-component bridge are presented along with the contraindications and suggestions of careful case selection. Three cases with congenitally missing maxillary lateral incisors in youthful patients are presented to supplement the theoretical outline and to describe and illustrate the clinical procedure.

  20. 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.

  1. 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.

  2. 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...

  3. BUILDING "BRIDGES" WITH QUALITY ASSURANCE

    Science.gov (United States)

    The papr describes how, rather than building "bridges" across centuries, quality assurance (QA) personnel have the opportunity to build bridges across technical disciplines, between public and private organizations, and between different QA groups. As reviewers and auditors of a...

  4. Existing Steel Railway Bridges Evaluation

    Science.gov (United States)

    Vičan, Josef; Gocál, Jozef; Odrobiňák, Jaroslav; Koteš, Peter

    2016-12-01

    The article describes general principles and basis of evaluation of existing railway bridges based on the concept of load-carrying capacity determination. Compared to the design of a new bridge, the modified reliability level for existing bridges evaluation should be considered due to implementation of the additional data related to bridge condition and behaviour obtained from regular inspections. Based on those data respecting the bridge remaining lifetime, a modification of partial safety factors for actions and materials could be respected in the bridge evaluation process. A great attention is also paid to the specific problems of determination of load-caring capacity of steel railway bridges in service. Recommendation for global analysis and methodology for existing steel bridge superstructure load-carrying capacity determination are described too.

  5. DOE Information Bridge

    CERN Document Server

    United States. Department of Energy. Office of Scientific and Technical Information

    DOE Information Bridge, a component of EnergyFiles, provides free, convenient, and quick access to full-text DOE research and development reports in physics, chemistry, materials, biology, environmental sciences, energy technologies, engineering, computer and information science, renewable energy, and other topics. This vast collection includes over 43,000 reports that have been received and processed by OSTI since January 1995.

  6. Bridging the Technological Gap.

    Science.gov (United States)

    Lazow, Robert; And Others

    The aim of "Bridging the Technological Gap" (BTG), a federally funded demonstration project, is to use microcomputer technology in the rehabilitation of the psychiatrically disabled. Through the use of a custom designed microcomputer software package, clients receive remediation in areas of specific cognitive and behavioral deficits. The project…

  7. Bridging a Cultural Gap

    Science.gov (United States)

    Leviatan, Talma

    2008-01-01

    There has been a broad wave of change in tertiary calculus courses in the past decade. However, the much-needed change in tertiary pre-calculus programmes--aimed at bridging the gap between high-school mathematics and tertiary mathematics--is happening at a far slower pace. Following a discussion on the nature of the gap and the objectives of a…

  8. 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...

  9. Building a Straw Bridge

    Science.gov (United States)

    Teaching Science, 2015

    2015-01-01

    This project is for a team of students (groups of two or three are ideal) to design and construct a model of a single-span bridge, using plastic drinking straws as the building material. All steps of the design, construction, testing and critiquing stages should be recorded by students in a journal. Students may like to include labelled diagrams,…

  10. 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)

  11. The Bridges of Taishun County

    Institute of Scientific and Technical Information of China (English)

    MaJianhe

    2003-01-01

    The American film The Bridges of Madison County captured the imagination of many Chinese moviegoers with its bittersweet love story and scenes of rustic covered bridges. But the U.S. can't lay sole claim to such spectacular rural sights:China has its own county worldrenowned for unforgettable bridges.

  12. 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....

  13. 77 FR 14690 - Drawbridge Operation Regulation; New Jersey Intracoastal Waterway (NJICW), Point Pleasant Canal, NJ

    Science.gov (United States)

    2012-03-13

    ...The Commander, Fifth Coast Guard District, has issued a temporary deviation from the regulations governing the operation of the Route 88/Veterans Memorial Bridge across Point Pleasant Canal, NJICW mile 3.0, at Point Pleasant, NJ. This deviation allows the bridge to remain closed-to-navigation in order to facilitate barrier gate replacement and extensive electrical remedial work on the...

  14. 75 FR 76280 - Regulated Navigation Area; Thea Foss and Wheeler-Osgood Waterways EPA Superfund Cleanup Site...

    Science.gov (United States)

    2010-12-08

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA11 Regulated Navigation Area; Thea Foss and Wheeler-Osgood... of the Thea Foss and Wheeler-Osgood Waterways in Commencement Bay, Tacoma, Washington. The RNA will... notice of proposed rulemaking (SNPRM) entitled Regulated Navigation Area; Thea Foss and...

  15. Numerical Prediction of Hydrodynamic Forces on A Berthed Ship Induced by A Passing Ship in Different Waterway Geometries

    Institute of Scientific and Technical Information of China (English)

    王宏志; 邹早建

    2016-01-01

    An investigation has been conducted to quantify the effect of waterway geometry on the form and magnitude of forces and moment experienced by a berthed ship due to a passing ship. By using the dynamic mesh technique and solving the unsteady RANS equations in conjunction with a RNGk−ε turbulence model, numerical simulation of the three-dimensional unsteady viscous flow around a passing ship and a berthed ship in different waterway geometries is conducted, and the hydrodynamic forces and moment acting on the berthed ship are calculated. The proposed method is verified by comparing the numerical results with existing empirical curves and a selection of results from model scale experiments. The calculated interaction forces and moment are presented for six different waterway geometries. The magnitude of the peak values and the form of the forces and moment on the berthed ship for different cases are investigated to assess the effect of the waterway geometry.The results of present study can provide certain guidance on safe maneuvering of a ship passing by a berthed ship.

  16. 75 FR 29695 - Security Zones; Sabine Bank Channel, Sabine Pass Channel and Sabine-Neches Waterway, TX

    Science.gov (United States)

    2010-05-27

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA87 Security Zones; Sabine Bank Channel, Sabine Pass Channel and Sabine-Neches Waterway, TX AGENCY: Coast Guard, DHS. ] ACTION: Notice of proposed rulemaking... facility in Sabine, TX and/or the Sabine Pass LNG facility located in Cheniere, LA. DATES: Comments...

  17. 75 FR 65232 - Security Zones; Sabine Bank Channel, Sabine Pass Channel and Sabine-Neches Waterway, TX

    Science.gov (United States)

    2010-10-22

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA87 Security Zones; Sabine Bank Channel, Sabine Pass Channel and Sabine-Neches Waterway, TX AGENCY: Coast Guard, DHS. ACTION: Interim rule with request comments... carriers while they are moored at the Golden Pass LNG facility in Sabine, TX and/or the Sabine Pass...

  18. 76 FR 1519 - Security Zones; Sabine Bank Channel, Sabine Pass Channel and Sabine-Neches Waterway, TX

    Science.gov (United States)

    2011-01-11

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA87 Security Zones; Sabine Bank Channel, Sabine Pass Channel and Sabine-Neches Waterway, TX AGENCY: Coast Guard, DHS. ACTION: Final rule. SUMMARY: The Coast Guard... encompassing the mooring basins of LNG carriers while they are moored at the Golden Pass LNG facility in...

  19. 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. 

  20. 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...... proposed simulation method for one-dimensional bridges to the mulit-variate setting. First a method of simulating approzimate, but often very accurate, diffusion bridges is proposed. These approximate bridges are used as proposal for easily implementable MCMC algorithms that produce exact diffusion bridges...

  1. 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

  2. Bridging Classroom Language Ethnography

    OpenAIRE

    GRENFELL, MICHAEL JAMES

    2012-01-01

    PUBLISHED Paper #5: Bridging Classroom Language Ethnography, New Literacy Studies and Bourdieu?s Social Philosophy: Principles and Practice The purpose of this paper is to analyze and synthesize the various ways that classroom language ethnography, NLS, and Bourdieu?s social philosophy, were integrated. The goal of the analysis and synthesis is to provide a fresh perspective and fruitful insights on literacy in all its manifestations that provides the foundations for a more robust...

  3. 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.

  4. 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).

  5. 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.

  6. 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.

  7. 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...

  8. 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...

  9. 77 FR 46287 - Safety Zone; Gulf Intracoastal Waterway, Mile Marker 35.2 to Mile Marker 35.5, West of Harvey...

    Science.gov (United States)

    2012-08-03

    ....2 to Mile Marker 35.5, West of Harvey Locks, Bank to Bank, Lafourche Parish, Larose, LA AGENCY... safety zone in the Gulf Intracoastal Waterway, Mile Marker 35.2 to Mile Marker 35.5, west of Harvey Locks... Waterway, Mile Marker 35.2 to Mile Marker 35.5, bank to bank, West of Harvey Locks. The U.S. Army Corps...

  10. Morphological aspects of myocardial bridges.

    Science.gov (United States)

    Lujinović, Almira; Kulenović, Amela; Kapur, Eldan; Gojak, Refet

    2013-11-01

    Although some myocardial bridges can be asymptomatic, their presence often causes coronary disease either through direct compression of the "tunnel" segment or through stimulation and accelerated development of atherosclerosis in the segment proximally to the myocardial bridge. The studied material contained 30 human hearts received from the Department of Anatomy. The hearts were preserved 3 to 5 days in 10% formalin solution. Thereafter, the fatty tissue was removed and arterial blood vessels prepared by careful dissection with special reference to the presence of the myocardial bridges. Length and thickness of the bridges were measured by the precise electronic caliper. The angle between the myocardial bridge fibre axis and other axis of the crossed blood vessel was measured by a goniometer. The presence of the bridges was confirmed in 53.33% of the researched material, most frequently (43.33%) above the anterior interventricular branch. The mean length of the bridges was 14.64 ± 9.03 mm and the mean thickness was 1.23 ± 1.32 mm. Myocardial bridge fibres pass over the descending blood vessel at the angle of 10-90 degrees. The results obtained on a limited sample suggest that the muscular index of myocardial bridge is the highest for bridges located on RIA, but that the difference is not significant in relation to bridges located on other branches. The results obtained suggest that bridges located on other branches, not only those on RIA, could have a great contractive power and, consequently, a great compressive force, which would be exerted on the wall of a crossed blood vessel.

  11. Modular FRP Composite Bridge Deck

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    The bridge infrastructure of the United States is in constant need of repair and rehabilitation. It is reported that 43% of the bridges in the USA have been identified as being structurally deficient or functionally obsolete due to corrosion. SuperdeckTM, a non-corrosive fiber reinforced polymer (FRP) composite bridge deck. The Deck is designed and engineered into a lightweight, strong and rigid structure that will not corrode. The deck sections, composed of hexagon and double-trapezoid profi...

  12. 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...

  13. Allocation of supplementary aeration stations in the Chicago waterway system for dissolved oxygen improvement.

    Science.gov (United States)

    Alp, Emre; Melching, Charles S

    2011-06-01

    The Chicago Waterway System (CWS), used mainly for commercial and recreational navigation and for urban drainage, is a 122.8 km branching network of navigable waterways controlled by hydraulic structures. The CWS receives pollutant loads from 3 of the largest wastewater treatment plants in the world, nearly 240 gravity Combined Sewer Overflows (CSO), 3 CSO pumping stations, direct diversions from Lake Michigan, and eleven tributary streams or drainage areas. Even though treatment plant effluent concentrations meet the applicable standards and most reaches of the CWS meet the applicable water quality standards, Dissolved Oxygen (DO) standards are not met in the CWS during some periods. A Use Attainability Analysis was initiated to evaluate what water quality standards can be achieved in the CWS. The UAA team identified several DO improvement alternatives including new supplementary aeration stations. Because of the dynamic nature of the CWS, the DUFLOW model that is capable of simulating hydraulics and water quality processes under unsteady-flow conditions was used to evaluate the effectiveness of new supplementary aeration stations. This paper details the use of the DUFLOW model to size and locate supplementary aeration stations. In order to determine the size and location of supplemental aeration stations, 90% compliance with a 5 mg/l DO standard was used as a planning target. The simulations showed that a total of four new supplementary aeration stations with oxygen supply capacities ranging from 30 to 80 g/s would be sufficient to meet the proposed target DO concentration for the North Branch and South Branch of the Chicago River. There are several aeration technologies, two of which are already being used in the CWS, available and the UAA team determined that the total capital costs of the alternatives range from $35.5 to $89.9 million with annual operations and maintenance costs ranging from $554,000 to $2.14 million. Supplemental aeration stations have been

  14. 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.

  15. Modeling evaluation of integrated strategies to meet proposed dissolved oxygen standards for the Chicago waterway system.

    Science.gov (United States)

    Melching, Charles S; Ao, Yaping; Alp, Emre

    2013-02-15

    The Chicago Waterway System (CWS) is a 113.8 km branching network of navigable waterways controlled by hydraulic structures in which the majority of flow is treated sewage effluent and there are periods of substantial combined sewer overflow. The Illinois Pollution Control Board (IPCB) designated the majority of the CWS as Secondary Contact and Indigenous Aquatic Life Use waters in the 1970s and made small alterations to these designations in 1988. Between 1988 and 2002 substantial improvements in the pollution control and water-quality management facilities were made in the Chicago area. The results of a Use Attainability Analysis led the Illinois Environmental Protection Agency (IEPA) to propose the division of the CWS into two new aquatic life use classes with appropriate dissolved oxygen (DO) standards. To aid the IPCB in their deliberations regarding the appropriate water use classifications and DO standards for the CWS, the DUFLOW model that is capable of simulating hydraulics and water-quality processes under unsteady-flow conditions was used to evaluate integrated strategies of water-quality improvement facilities that could meet the proposed DO standards during representative wet (2001) and dry (2003) years. A total of 28 new supplementary aeration stations with a maximum DO load of 80 or 100 g/s and aerated flow transfers at three locations in the CWS would be needed to achieve the IEPA proposed DO standards 100% of the time for both years. A much simpler and less costly (≈one tenth of the cost) system of facilities would be needed to meet the IEPA proposed DO standards 90% of the time. In theory, the combinations of flow augmentation and new supplemental aeration stations can achieve 100% compliance with the IEPA proposed DO standards, however, 100% compliance will be hard to achieve in practice because of-(1) difficulties in determining when to turn on the aeration stations and (2) localized heavy loads of pollutants during storms that may yield

  16. London Bridge Is Shaking Funny

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    Bridges generally don’t fall down without warning;they crack first. Searching for cracks is a tedious business,though, and bridge inspectors bave been known to miss them. Charles Farrar,a civil engineer at Los Alamos Na-

  17. 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

  18. 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

  19. 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.

  20. Linguistic Barriers and Bridges

    DEFF Research Database (Denmark)

    Thuesen, Frederik

    2016-01-01

    and intercultural communication, this article analyses interviews with 31 employees from two highly ethnically diverse Danish workplaces. The article shows how linguistic barriers such as different levels of majority language competence and their consequent misunderstandings breed mistrust and hostility, whilst......The influence of language on social capital in low-skill and ethnically diverse workplaces has thus far received very limited attention within the sociology of work. As the ethnically diverse workplace is an important social space for the construction of social relations bridging different social...... groups, the sociology of work needs to develop a better understanding of the way in which linguistic diversity influences the formation of social capital, i.e. resources such as the trust and reciprocity inherent in social relations in such workplaces. Drawing on theories about intergroup contact...

  1. Looking Beyond the Bridge

    DEFF Research Database (Denmark)

    Jahn, Elke; Rosholm, Michael

    We perform a comprehensive analysis of the stepping-stone effect of temporary agency employment on unemployed workers. Using the timing-of-events approach, we not only investigate whether agency employment is a bridge into regular employment but also analyze its effect on post-unemployment wages ...... is even more effective in tight labor markets, where firms use agency employment primarily to screen po-tential candidates for permanent posts. Finally, our results suggest that agency employment may improve subsequent match quality in terms of wages and job duration....... and job stability for unemployed Danish workers. We find evidence of large positive treatment effects, particularly for immigrants. There is also some indication that higher treatment intensity increases the likelihood of leav-ing unemployment for regular jobs. Our results show that agency employment...

  2. 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.

  3. Torsional instability in suspension bridges: The Tacoma Narrows Bridge case

    Science.gov (United States)

    Arioli, Gianni; Gazzola, Filippo

    2017-01-01

    All attempts of aeroelastic explanations for the torsional instability of suspension bridges have been somehow criticised and none of them is unanimously accepted by the scientific community. We suggest a new nonlinear model for a suspension bridge and we perform numerical experiments with the parameters corresponding to the collapsed Tacoma Narrows Bridge. We show that the thresholds of instability are in line with those observed the day of the collapse. Our analysis enables us to give a new explanation for the torsional instability, only based on the nonlinear behavior of the structure.

  4. 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...

  5. 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 approach...

  6. 78 FR 69803 - Drawbridge Operation Regulations; Gulf Intracoastal Waterway, Venice, FL

    Science.gov (United States)

    2013-11-21

    ... Creek (US-41) Twin Bridges will allow the Iron Man Triathlon event to be unimpeded for an eight hour... to navigation. This action will accommodate the Sarasota Iron Man Triathlon held annually on the... Triathlon event. * * * * * Dated: October 25, 2013. J.H. Korn, Rear Admiral, U.S. Coast...

  7. 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.

  8. 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]....

  9. 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.

  10. 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...

  11. Lithodynamic processes in the construction area of a bridge across the kerch strait

    Directory of Open Access Journals (Sweden)

    Vvedenskiy Aleksey Rostislavovich

    2016-11-01

    Full Text Available The information about the evolution of the bottom topography in the construction area is necessary in the design and construction of hydraulic structures in sea, as well as information about possible deformations of the bottom caused by both natural reasons and the appearance of new hydraulic objects in the waters. In the given research the authors propose an analysis of lithodynamic processes in the area of the construction of the bridge across the Kerch Strait. Several physico-mathematical models were used for calculation and description of lithodynamic processes in the construction site of the Kerch Bridge. They may be divided into two groups: atmospheric and water. Many important properties of hydrometeorological conditions may be obtained only by modeling. The model WRF is used in the research, which is applied in many foreign and domestic centers for simulation and forecast of regional atmospheric circulation due to its high quality and ease. The main steps of the calculations are provided: beginning with the collection of basic information up to combining the results of numerical experiments on several mathematical models. Special attention is paid to sedimentation and erosion associated with construction of temporary piers and waterways to them.

  12. 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.

  13. 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....

  14. 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.

  15. Waterway e sviluppo del territorio: nuova mobilità e turismo sostenibile

    Directory of Open Access Journals (Sweden)

    Oriana Giovinazzi

    2010-10-01

    Full Text Available Spesso origine dei primi insediamenti urbani, i corsi d’acqua sono stati nei secoli fonte di sostentamento per le popolazioni e strumento di scambio tra genti e culture. Proprio per il loro scorrere attraverso il territorio, essi sono per definizione luoghi di relazione, di intersezione tra diverse realtà urbane dove si incontrano ambiente, architettura, pianificazione, trasporti ma anche arte, cultura e turismo. Per questa loro caratteristica, le vie d’acqua rappresentano una grande potenzialità per lo sviluppo del territorio sia in termini di mobilità – di merci e di persone - che di turismo sostenibile. La loro riqualificazione permette di recuperare il ruolo di spazio pubblico e di paesaggio rurale, urbano e turistico di qualità; luoghi di fruizione turistica, culturale, gastronomica e sportiva, quindi di qualità della vita. Dopo decenni di oblio, sollecitata dal rinnovato interesse verso questi assi e anche dalle direttive dell’Unione Europee, l’Italia e, in particolare il Nord del paese, muove i primi passi verso la valorizzazione delle waterway a fini turistico-culturali, aprendo nuove possibilità di sviluppo del territorio. Sia pur con ritardo rispetto ad altri Paesi, che da anni e in diverse forme valorizzano e “sfruttano” le vie d’acqua, si avverte anche in Italia un cambio di mentalità che vede nell’uso e nel recupero di tale risorsa uno strumento importante per garantire la sostenibilità ambientale ed economica e il recupero di una identità culturale quasi dimenticata.

  16. Redundancy Evaluation of Fracture Critical Bridges

    OpenAIRE

    Bapat, Amey Vivek

    2014-01-01

    Cases of brittle fractures in major bridges prompted AASHTO to publish its first fracture control plan in 1978. It focused on material and fabrication standards, and required periodic 24-month hands-on inspection of bridges with fracture critical members. The practical result of this plan was to significantly increase the life cycle cost of these bridges, rendering them uneconomical. Apart from the Point Pleasant Bridge that failed in 1967, no other bridge has collapsed in the USA following a...

  17. 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...... scenarios outlined. LCA study is performed with the ReCiPe methodology with life cycle inventories data from public database. Five selected mid-point level impact categories and the energy consumption are presented. The result shows that the steel bridge has a better environmental performance due...... to the recycling strategy, while the initial material manufacture is the most dominant phase that contributes large environmental impact in both design solutions....

  18. Application of Geotextiles in Jiepai Waterway Regulation Engineering of the Yangtze River%土工织物在长江界牌航道整治工程中的应用

    Institute of Scientific and Technical Information of China (English)

    李国祥; 胡义龙

    2001-01-01

    通过长江界牌航道整治工程实例介绍土工织物在航道整治工程中的应用情况。%Based on the practical example of Jiepai Waterway Regulation Engineering of the Yangtze River, it introduces the application of geotextile in waterway regulation engineering.

  19. 采煤机用电动机冷却水路的探讨%Discussion of Cooling Waterway of the Coal-winning Machine Motor

    Institute of Scientific and Technical Information of China (English)

    景刚

    2014-01-01

    Taking the improved cooling waterway of the prototype of YBCS700 motor as example, some expe-rience to design the cooling waterway when increasing the coal-winning machine motor power grade and power densi-ty was introduced.%以试制的YBCS700电动机冷却水路的改进过程为例,介绍了采煤机用电动机在功率加大和功率密度增加时冷却水路设计的一些经验。

  20. The Akashi Kaikyo Bridge and the Storebælt Bridge

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

    With the completion of the Akashi Kaikyo Bridge and the Storebælt East Bridge the development of the suspension bridge technology in the 20th century has manifested itself in two impressive structures. With the present echnology may bridges of similar (and also more modest) dimensions...... will undoubtedly be built far into the next century. For bridges going beyond the spans of existing bridges it is, however, likely that new concepts will be developed....

  1. River ice jams at bridges

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, D. [New Brunswick Dept. of Transportation, Fredericton, NB (Canada); Beltaos, S. [National Water Research Institute, Burlington, ON (Canada)

    2000-12-01

    Ice jamming, known to cause high water levels at even moderate river flows, is described as both the main and least understood source of ice-related bridge damages. This paper describes a joint study by the New Brunswick Department of Transportation, the Department of the Environment, local governments, and the National Water Research Institute, designed to address problems associated with the interaction of ice jams and bridges. The study consists of collecting information at each of four sites in New Brunswick including: historical data on ice jam locations, causes, and water levels; channel bathymetry, width and slope within each study centred at the respective bridge; and documentation of ice conditions throughout the ice season, including measurement of ice cover thickness, observation of breakup mechanisms, times, causes, characteristics and possible impacts of ice jam release. Data analysis will include determination of high stages due to ice jams or surges caused by upstream ice jam releases, scour potential of surges, and quantification of the structure's capacity to restrain ice movement and to cause jams. The principal objective of the study is to advance beyond empiricism and to develop rational design criteria for bridges by anticipating the effects of climate changes and by incorporating local meteorological and hydrometric records into bridge design for added safety.

  2. 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.

  3. 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...

  4. 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...... with the minimum acceptable surface temperature regarding surface condensation or mold growth, implemented in the Danish Building Regulations in 2010, and the calculation method for this temperature based on international standards is discussed. The introduction of the minimum acceptable surface temperature has...

  5. An Expert System for Concrete Bridge Management

    DEFF Research Database (Denmark)

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

    1997-01-01

    management systems are presently being implemented by bridge authorities in several countries. The prototype of an expert system for concrete bridge management is presented in this paper, with its functionality relying on two modules. The inspection module relies on a periodic acquisition of field......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...

  6. 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.

  7. Balanced bridge feedback control system

    Science.gov (United States)

    Lurie, Boris J. (Inventor)

    1990-01-01

    In a system having a driver, a motor, and a mechanical plant, a multiloop feedback control apparatus for controlling the movement and/or positioning of a mechanical plant, the control apparatus has a first local bridge feedback loop for feeding back a signal representative of a selected ratio of voltage and current at the output driver, and a second bridge feedback loop for feeding back a signal representative of a selected ratio of force and velocity at the output of the motor. The control apparatus may further include an outer loop for feeding back a signal representing the angular velocity and/or position of the mechanical plant.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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...

  13. 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.

  14. Noise Considerations in Resistance Bridges

    DEFF Research Database (Denmark)

    Diamond, Joseph M.

    1963-01-01

    A signal-to-noise analysis is made of the Wheatstone bridge, where the unknown and standard resistors may be at different temperatures, a situation which occurs in resistance thermometry. The limiting condition is assumed to be dissipation in the unknown resistor. It is shown that the ratio arms ...

  15. 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...

  16. 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

  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 Strömsund Bridge (from 1955) to 890 m in the Tatara Bridge (from 1999)....

  18. Building Bridges One Line at a Time

    Science.gov (United States)

    Grigsby, Cathy Murray

    2012-01-01

    In this article, first-grade students were taught the different kinds of lines that were part of the construction of various bridges--the curved lines of the arches of stone bridges, straight lines connecting the cables of a suspension bridge, vertical lines, horizontal lines, and so on. They gained practice in drawing structures and in fine brush…

  19. 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.

  20. Beginning Course Surveys: Bridges for Knowing and Bridges for Being

    Directory of Open Access Journals (Sweden)

    David Starr-Glass

    2011-06-01

    Full Text Available The use of a participant survey, administered at the outset of an online course, can provide information useful in the management of the learning environment and in its subsequent redesign. Such information can clarify participants’ prior experience, expectations, and demographics. But the very act of enquiring about the learner also signals the instructor’s social presence, relational interest, and desire to enter into an authentic dialogue. This study examines the use of participant surveys in online management courses. The first section discusses the informational bridges that this instrument provides. The second section considers survey responses to open-ended questions dealing with student sentiments. This analysis suggests that the survey plays a valuable part in accentuating social presence and in initiating relational bridges with participants.

  1. ESTIMATION OF ECONOMIC EXPEDIENCY OF «BRIDGE-PRE-BRIDGE TERRITORY» SYSTEM

    Directory of Open Access Journals (Sweden)

    A. A. Lapko

    2008-01-01

    Full Text Available The paper considers principles that form «Bridge-Pre-Bridge Territory» system. The method is proposed for calculation of expenses on technical research for development of projects on usage of pre-bridge territories. Usage of site class number for natural conditions makes it possible to estimate investment attractiveness of «Bridge-Pre-Bridge Territory» system.

  2. 33 CFR 115.70 - Advance approval of bridges.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Advance approval of bridges. 115... BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.70 Advance approval of bridges. (a) The General Bridge Act of 1946 requires the approval of the location and plans of bridges...

  3. Performance analysis of LAN bridges and routers

    Science.gov (United States)

    Hajare, Ankur R.

    1991-01-01

    Bridges and routers are used to interconnect Local Area Networks (LANs). The performance of these devices is important since they can become bottlenecks in large multi-segment networks. Performance metrics and test methodology for bridges and routers were not standardized. Performance data reported by vendors is not applicable to the actual scenarios encountered in an operational network. However, vendor-provided data can be used to calibrate models of bridges and routers that, along with other models, yield performance data for a network. Several tools are available for modeling bridges and routers - Network II.5 was used. The results of the analysis of some bridges and routers are presented.

  4. [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.

  5. Problems associated with nondestructive evaluation of bridges

    Science.gov (United States)

    Prine, David W.

    1995-05-01

    The US has 542,000 bridges that consume billions of dollars per year in construction, rehabilitation, and maintenance funds and which are the lifelines of US commerce. The 1992 ISTEA (Intermodal Surface Transportation Efficiency Act) mandates the implementation of a quantitative computerized bridge management system by 1996. A prime need of such a system are quantitative bridge inspection methods to feed accurate reliable condition information to the huge database of bridges. Nondestructive evaluation (NDE) will fill a critical need in the implementation of effective bridge management. However, many serious barriers exist to the widespread routine application of this technology to bridges. This paper provides an overview of the typical problems associated with applying NDE to bridges.

  6. 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.

  7. 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....

  8. 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....

  9. Cochleates bridged by drug molecules.

    Science.gov (United States)

    Syed, Uwais M; Woo, Amy F; Plakogiannis, Fotios; Jin, Tuo; Zhu, Hua

    2008-11-03

    A new type of cochleate, able to microencapsulate water-soluble cationic drugs or peptides into its inter-lipid bi-layer space, was formed through interaction between negatively charged lipids and drugs or peptides acting as the inter-bi-layer bridges instead of multi-cationic metal ions. This new type of cochleate opened up to form large liposomes when treated with EDTA, suggesting that cationic organic molecules can be extracted from these cochleates in a way similar to multivalent metal ions from metal ion-bridged cochleates. Cochleates can be produced in sub-micron size using a method known as "hydrogel isolated cochleation" or simply by increasing the ratio of multivalent cationic peptides over negatively charged liposomes. When nanometer-sized cochleates and liposomes containing the same fluorescent labeled lipid component were incubated with human fibroblasts cells under identical conditions, cells exposed to cochleates showed bright fluorescent cell surfaces, whereas those incubated with liposomes did not. This result suggests that cochleates' edges made them fuse with the cell surfaces as compared to edge free liposomes. This mechanism of cochleates' fusion with cell membrane was supported by a bactericidal activity assay using tobramycin cochleates, which act by inhibiting intracellular ribosomes. Tobramycin bridged cochleates in nanometer size showed improved antibacterial activity than the drug's solution.

  10. Salt bridges: geometrically specific, designable interactions.

    Science.gov (United States)

    Donald, Jason E; Kulp, Daniel W; DeGrado, William F

    2011-03-01

    Salt bridges occur frequently in proteins, providing conformational specificity and contributing to molecular recognition and catalysis. We present a comprehensive analysis of these interactions in protein structures by surveying a large database of protein structures. Salt bridges between Asp or Glu and His, Arg, or Lys display extremely well-defined geometric preferences. Several previously observed preferences are confirmed, and others that were previously unrecognized are discovered. Salt bridges are explored for their preferences for different separations in sequence and in space, geometric preferences within proteins and at protein-protein interfaces, co-operativity in networked salt bridges, inclusion within metal-binding sites, preference for acidic electrons, apparent conformational side chain entropy reduction on formation, and degree of burial. Salt bridges occur far more frequently between residues at close than distant sequence separations, but, at close distances, there remain strong preferences for salt bridges at specific separations. Specific types of complex salt bridges, involving three or more members, are also discovered. As we observe a strong relationship between the propensity to form a salt bridge and the placement of salt-bridging residues in protein sequences, we discuss the role that salt bridges might play in kinetically influencing protein folding and thermodynamically stabilizing the native conformation. We also develop a quantitative method to select appropriate crystal structure resolution and B-factor cutoffs. Detailed knowledge of these geometric and sequence dependences should aid de novo design and prediction algorithms.

  11. 广深港客运专线工程大跨度桥梁施工关键措施的研究%Research on the key measures of large span bridge construction Guangzhou-Shenzhen-Hong Kong passenger dedicated line engineering

    Institute of Scientific and Technical Information of China (English)

    李锦平; 钱治国

    2013-01-01

    In this paper,the related key technologies of Guangzhou-Shenzhen-Hong Kong Passenger Dedicated Line Engineering Shawan Waterway Bridge construction process as an example,combining the Shawan bridge natural conditions, geologic al,hydrological,climatic conditions;some like engineering in the advanced technology was adopted to ensure the safety and quality of the control engineering,especially to make some study of the process of the construction of large span bridge technology, research on a series of large span bridge construction technology of passenger dedicated line,not only can be used for the construction of Shawan Waterway Bridge,and construction of other similar projects are very important,valuable reference.%  本文以广深港客运专线工程沙湾水道特大桥施工过程的相关的关键技术为例,结合该沙湾水道特大桥施工的自然条件、地质、水文、气候条件;为确保该控制性工程的安全与质量采取了一些在类似工程的先进技术,尤其对大跨度桥梁施工过程中的技术做出了一些研究,研究了一系列关于客运专线上大跨度桥梁施工技术,不仅可以用于沙湾水道特大桥的施工,而且对其它类似工程的建设还有非常重要的、宝贵的借鉴意义。

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. Mathematical Modelling of Bridges with SAP2000

    OpenAIRE

    Maraž, Miha

    2006-01-01

    The present work describes a relatively new programme module, which is enhanced in the recently released versions of SAP2000 software. The new module, called Bridge Modeler, is intended for simple, parametric mathematical modelling of bridges. The modelling procedure is explained on a test case through the steps of a user-friendly Bridge Wizard. For each step, we described the basic principles and the application possibilities as well as some limitations. We also explained two types of analys...

  19. Buddha and the bridging relations.

    Science.gov (United States)

    Banerjee, Rahul

    2008-01-01

    The chapter reviews a classical Indian model of consciousness found in the Abhidhamma, a collection of seven treatises in the Pali Canon Tipitaka. The model was based on observations made during advanced vipassana practice, a first-person method taught by the Buddha. The climax of the model consists in the elucidation of 24 'Bridging Relations' causally linking the stream of consciousness, its contents and associated physical events. Review of such a model based on a specialized first-person technique could prove to be a resource of useful ideas providing directions for further research.

  20. 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.

  1. 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

  2. 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

  3. 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.

  4. CONDITION RATING SYSTEM FOR THAILAND'S CONCRETE BRIDGES

    Directory of Open Access Journals (Sweden)

    Bonaventure H.W. Hadikusumo

    2010-06-01

    Full Text Available The Bridge Management System is designed to maximise use of available data and determine the optimal strategy to perform necessary improvements to bridges in the most cost-effective manner. This paper provides a condition rating system to meet the requirements of Thailand’s Department of Highways (DOH. A rating system to assess the existing condition of bridges is proposed. Segmental inspection is developed to execute efficient element-level evaluations and collect data that demonstrate deterioration patterns in bridge elements. The paper also describes inspection procedures for field survey execution, which enables observed distresses at the level of sub-elements or members to be allocated. Recommendations from bridge experts reveal that the proposed rating system is robust, implementable in actual practice, and suitable for efficient application in evaluating the nation’s concrete highway bridges. Although the bridge condition rating was developed in response to the specific characteristics of Thailand’s bridges, the proposed methodology can easily be extended to other bridge agencies.

  5. 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.

  6. Assessment of the Reliability of Concrete Bridges

    DEFF Research Database (Denmark)

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

    a significant shift in emphasis for the highways authorities around the world away from the design of new structures over to maintaining the existing infrastructure. As a result, bridge owners are seeking improved ways of inspecting, assessing, maintaining and repairing their existing stock of bridges...... 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...

  7. 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.

  8. Research on Green Degree Evaluation Indexes of Waterway Transport Enterprises%水路运输企业物流绿色度评价指标研究

    Institute of Scientific and Technical Information of China (English)

    操露; 刚蕾; 金莹

    2012-01-01

    This paper studies on the green degree evaluation indexes of waterway transport enterprises. According to thecharacteristics of waterway transportation, the green degree e- valuation indexes system of water transport of enterprise is established. What's more, by using multilevel evaluation method, the quantitative evaluation results of green degree evaluation of waterway transport enterprises are obtained, which can be used to instruct or improve the logistics activities of the enterprise.%主要研究水路运输企业物流系统绿色度评价指标.根据水路运输的特点,建立了企业水路运输的绿色度评价指标体系,并采用多级模糊评价法进行了综合评价,得出水路运输企业绿色度评价的定量结果.企业可依据此结果指导或改进自身的物流活动。

  9. 23 CFR 650.409 - Evaluation of bridge inventory.

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Evaluation of bridge inventory. 650.409 Section 650.409... Evaluation of bridge inventory. (a) Sufficiency rating of bridges. Upon receipt and evaluation of the bridge inventory, a sufficiency rating will be assigned to each bridge by the Secretary in accordance with...

  10. 23 CFR 650.807 - Bridges requiring a USCG permit.

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Bridges requiring a USCG permit. 650.807 Section 650.807... BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.807 Bridges requiring a USCG... improvement or construction of a bridge over navigable waters except for the exemption exercised by FHWA...

  11. 33 CFR 118.65 - Lights on fixed bridges.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lights on fixed bridges. 118.65 Section 118.65 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.65 Lights on fixed bridges. (a) Each fixed bridge span over a...

  12. 33 CFR 118.70 - Lights on swing bridges.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lights on swing bridges. 118.70 Section 118.70 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.70 Lights on swing bridges. (a) Swing span lights on through bridges....

  13. 33 CFR 118.85 - Lights on vertical lift bridges.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lights on vertical lift bridges... BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.85 Lights on vertical lift bridges. (a) Lift span lights. The vertical lift span of every vertical lift bridge shall be lighted so that the center of...

  14. 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

  15. Light-weight aluminium bridges and bridge decks. An overview of recent applications

    NARCIS (Netherlands)

    Maljaars, J.; Soetens, F.; Kluyver, D. de

    2008-01-01

    The last decades have shown a large increase in the application of aluminium alloys for light-weight bridges. For bridge construction, aluminium alloys have some specific advantages, but also some points of attention. This paper deals with some recent projects of aluminium bridges, and for these pro

  16. 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.

  17. Global monitoring concept for bridges

    Science.gov (United States)

    Bergmeister, Konrad; Santa, Ulrich

    2000-06-01

    Knowledge of the integrity of in-service structures on a continuous time basis is an ultimate objective for owners and maintenance authorities. The development of a life extension and/or replacement strategy for highway structures is a crucial point in an effective bridge management system. A key component of such a bridge management system is a means of surveillance techniques and determining the condition of an existing structure within the normative and budgetary constraints. Recent advances in sensing technologies and material/structure damage characterization combined with current developments in computations and communications have resulted in a significant interest in developing diagnostic technologies for monitoring the integrity of and for the detection of damages of structures. To identify anomalies and deterioration processes, it is essential to understand the relationships between the signal measurements and the real occurred phenomena. Therefore, the comparison of measured and calculated data in order to tune and validate the mechanical and numerical model assumptions is an integral part of any system analysis. Finally, the interpreted results of all measurements should be the basis for the condition assessment and the safety evaluation of a structure to facilitate replacement and repair decisions.

  18. 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 psycholog......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...... psychologists can benefit from engaging with historical sources by being able to contextualise their findings and enrich their theoretical models. It is not only that all social and psychological phenomena have a history but this history is very much part of present-day and future developments. On the other...... 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...

  19. Salt-bridge energetics in halophilic proteins.

    Directory of Open Access Journals (Sweden)

    Arnab Nayek

    Full Text Available Halophilic proteins have greater abundance of acidic over basic and very low bulky hydrophobic residues. Classical electrostatic stabilization was suggested as the key determinant for halophilic adaptation of protein. However, contribution of specific electrostatic interactions (i.e. salt-bridges to overall stability of halophilic proteins is yet to be understood. To understand this, we use Adaptive-Poison-Boltzmann-Solver Methods along with our home-built automation to workout net as well as associated component energy terms such as desolvation energy, bridge energy and background energy for 275 salt-bridges from 20 extremely halophilic proteins. We then perform extensive statistical analysis on general and energetic attributes on these salt-bridges. On average, 8 salt-bridges per 150 residues protein were observed which is almost twice than earlier report. Overall contributions of salt-bridges are -3.0 kcal mol-1. Majority (78% of salt-bridges in our dataset are stable and conserved in nature. Although, average contributions of component energy terms are equal, their individual details vary greatly from one another indicating their sensitivity to local micro-environment. Notably, 35% of salt-bridges in our database are buried and stable. Greater desolvation penalty of these buried salt-bridges are counteracted by stable network salt-bridges apart from favorable equal contributions of bridge and background terms. Recruitment of extensive network salt-bridges (46% with a net contribution of -5.0 kcal mol-1 per salt-bridge, seems to be a halophilic design wherein favorable average contribution of background term (-10 kcal mol-1 exceeds than that of bridge term (-7 kcal mol-1. Interiors of proteins from halophiles are seen to possess relatively higher abundance of charge and polar side chains than that of mesophiles which seems to be satisfied by cooperative network salt-bridges. Overall, our theoretical analyses provide insight into halophilic

  20. A Statistical Observation of Crowns and Bridges in 1988 Part 2 : Bridge

    OpenAIRE

    小林, 賢一; 小坂, 茂; 柳田, 史城; 稲生, 衡樹; 大島, 俊明; 高橋, 喜博; 岩井, 啓三; 甘利, 光治; 中根, 卓

    1991-01-01

    A study was made of 207 bridges which had been fabricated for patients at the Prosthodontic Clinic of Matsumoto Dental College during 1988. Some of results were as follows; 1) 47.3% of the patients were males and 52.7% were females. 2) 92.8% of the patients were between 20 and 69 years old. 3) 65.2%of the bridges were fabricated as 3-unit bridges. 4) 77.8% were fabricated as 1-pontic bridges. 5) There were fewer bridge retainers for the lower anterior segment than for other segments. 6) 52.3%...

  1. Mapping the potential distribution of the invasive Red Shiner, Cyprinella lutrensis (Teleostei: Cyprinidae) across waterways of the conterminous United States

    Science.gov (United States)

    Poulos, Helen M.; Chernoff, Barry; Fuller, Pam L.; Butman, David

    2012-01-01

    Predicting the future spread of non-native aquatic species continues to be a high priority for natural resource managers striving to maintain biodiversity and ecosystem function. Modeling the potential distributions of alien aquatic species through spatially explicit mapping is an increasingly important tool for risk assessment and prediction. Habitat modeling also facilitates the identification of key environmental variables influencing species distributions. We modeled the potential distribution of an aggressive invasive minnow, the red shiner (Cyprinella lutrensis), in waterways of the conterminous United States using maximum entropy (Maxent). We used inventory records from the USGS Nonindigenous Aquatic Species Database, native records for C. lutrensis from museum collections, and a geographic information system of 20 raster climatic and environmental variables to produce a map of potential red shiner habitat. Summer climatic variables were the most important environmental predictors of C. lutrensis distribution, which was consistent with the high temperature tolerance of this species. Results from this study provide insights into the locations and environmental conditions in the US that are susceptible to red shiner invasion.

  2. Genetic and life-history trait variation of the amphipod Melita plumulosa from polluted and unpolluted waterways in eastern Australia

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Pann Pann [Evolution and Ecology Research Centre, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052 (Australia); Hyne, Ross V. [Ecotoxicology and Environmental Contaminants Section, NSW Department of Environment and Climate Change, PO Box 29, Lidcombe, NSW 1825 (Australia); Mann, Reinier M. [Centre for Ecotoxicology, Department of Environmental Sciences, University of Technology-Sydney, C/-PO Box 29, Lidcombe, NSW 1825 (Australia); Ballard, J. William O. [Evolution and Ecology Research Centre, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052 (Australia)], E-mail: w.ballard@unsw.edu.au

    2008-09-15

    To monitor genetic diversity and environmental contamination in eastern Australia, toxicity studies have employed the sensitive benthic amphipod Melita plumulosa. The goal of this study was to examine the genetic and life-history variability of natural populations of M. plumulosa from the Parramatta (polluted) and Hawkesbury (unpolluted) Rivers. The underlying genetics of the populations in these distinct waterways was examined at one mitochondrial (cytochrome c oxidase subunit I (COI)) and one nuclear (ribosomal internal transcribed spacer region 1 (ITS1)) locus. Seven unique haplotypes for COI were found amongst animals from the Parramatta River, while animals from the Hawkesbury River showed a complete absence of genetic variation at this locus. At ITS1 a total of two sequence variants were found amongst Parramatta River amphipods and three sequence variants among Hawkesbury River animals, with no common variants across the two river systems. To establish whether genetic differences were associated with organismal responses to toxicant exposure, two life-history trait variables (female head length as an estimator of amphipod size and female fecundity) were analyzed. Life-history trait analyses showed that females from the Hawkesbury River were significantly larger and more fecund. These data have critical implications for toxicity tests, the use of laboratory cultures for testing purposes, and environmental contamination in Sydney Harbor.

  3. 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.

  4. Heavy Vehicles on Minor Highway Bridges

    DEFF Research Database (Denmark)

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

    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...

  5. Passing the Einstein-Rosen bridge

    CERN Document Server

    Katanaev, M O

    2013-01-01

    We relax the requirement of geodesic completeness of a space-time. Instead, we require test particles trajectories to be smooth only in the physical sector. Test particles trajectories for Einstein--Rosen bridge are proved to be smooth in the physical sector, and particles can freely penetrate the bridge in both directions.

  6. 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.

  7. 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...

  8. 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.

  9. 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...

  10. 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. Fi...

  11. 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......, and gives a large positive bending moment below the load and a smaller negative bending moment in the unloaded side. When the Pearl-Chain Bridge concept is compared to other pre-fabricated arch bridge solutions we find a number of advantages when using Pearl-Chain Bridges: Straight elements, combination...

  12. 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...

  13. Seismic response of steel suspension bridge

    Energy Technology Data Exchange (ETDEWEB)

    McCallen, D.B. [Lawrence Livermore National Lab., CA (United States); Astaneh-Asl, A. [California Univ., Berkeley, CA (United States). Dept. of Civil and Environmental Engineering

    1996-11-01

    Performing accurate, realistic numerical simulations of the seismic response of long-span bridges presents a significant challenge to the fields of earthquake engineering and seismology. Suspension bridges in particular represent some of the largest and most important man-made structures and ensuring the seismic integrity of these mega-structures is contingent on accurate estimations of earthquake ground motions and accurate computational simulations of the structure/foundation system response. A cooperative, multi-year research project between the Univ. of California and LLNL was recently initiated to study engineering and seismological issues essential for simulating the response of major structures. Part of this research project is focused on the response of the long-span bridges with the San Francisco-Oakland Bay Bridge serving as a case study. This paper reports on the status of this multi-disciplinary research project with emphasis on the numerical simulation of the transient seismic response of the Bay Bridge.

  14. 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...... 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...... 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....

  15. 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 �...

  16. 右线盾构穿越人行天桥施工技术%The Right Line of Shield Crossing Pedestrian Bridge Construction Technology

    Institute of Scientific and Technical Information of China (English)

    施钧; 柴金玲

    2015-01-01

    Tong tai road footbridge on the east side tong tai road and golden waterway junc-tion.Due to the bridge pier is located in zhengzhou city rail transit line one is a phase of the convention and exhibition center to the top of the line between the Yellow River east road station right tunnel,subway construction will affect it.Is studied in this paper,its construction technology,the key to the bridge con-struction technology are introduced,namely the footbridge to protect and shield construction.And under the seriously organize the implementation,the mentally incapacitated person Line bridge completed showed that yellow will range right wire shield crossing tong tai road pedestrian bridge construction tech-nology has the scientific nature and rationality.%河南省郑州市地铁一号线,运行区间会展中心至黄河东路右隧道上方是通泰路的人行天桥的桥墩,在进行地铁施工时会对桥墩产生影响。对其施工技术进行了研究,介绍了该天桥的关键施工技术,即人行天桥保护以及盾构施工。并在认真组织实施下,该人行天桥顺利竣工表明,黄会区间右线盾构穿越通泰路人行天桥施工技术具有科学性和合理性。

  17. 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...

  18. 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.

  19. 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.

  20. 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.

  1. Asymptotics of a horizontal liquid bridge

    Science.gov (United States)

    Haynes, M.; O'Brien, S. B. G.; Benilov, E. S.

    2016-04-01

    This paper uses asymptotic techniques to find the shape of a two dimensional liquid bridge suspended between two vertical walls. We model the equilibrium bridge shape using the Laplace-Young equation. We use the Bond number as a small parameter to deduce an asymptotic solution which is then compared with numerical solutions. The perturbation approach demonstrates that equilibrium is only possible if the contact angle lies within a hysteresis interval and the analysis relates the width of this interval to the Bond number. This result is verified by comparison with a global force balance. In addition, we examine the quasi-static evolution of such a two dimensional bridge.

  2. Calculations in bridge aeroelasticity via CFD

    Energy Technology Data Exchange (ETDEWEB)

    Brar, P.S.; Raul, R.; Scanlan, R.H. [Johns Hopkins Univ., Baltimore, MD (United States)

    1996-12-31

    The central focus of the present study is the numerical calculation of flutter derivatives. These aeroelastic coefficients play an important role in determining the stability or instability of long, flexible structures under ambient wind loading. A class of Civil Engineering structures most susceptible to such an instability are long-span bridges of the cable-stayed or suspended-span variety. The disastrous collapse of the Tacoma Narrows suspension bridge in the recent past, due to a flutter instability, has been a big impetus in motivating studies in flutter of bridge decks.

  3. 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 analytical prediction methods. In this paper, an analytical model that departs from the strip assumption is used to describe the gust loading on a thin airfoil. A parallel is drawn between the analytical model and direct measurements of gust loading on motionless closed-box girder bridge decks. Empirical...

  4. Transformation of the bridge during drop separation

    Science.gov (United States)

    Chashechkin, Yu. D.; Prokhorov, V. E.

    2016-05-01

    The geometry of flows during separation of pendant drops of liquids with significantly different physical properties (alcohol, water, glycerin, oil) has been studied by high-speed video recording. The dynamics of the processes involving the formation of bridges of two characteristic shapes—slightly nonuniform in thickness and with thinning of the upper and lower ends—has been investigated. It has been shown that the shape change of the separated bridge has a number of stages determined by the properties of the liquid. As a result, the bridge is transformed into a small drop—a satellite drop.

  5. Closure technique for the hybrid girder cable stayed bridge of Edong Bridge

    Institute of Scientific and Technical Information of China (English)

    Liu Minghu; Tan Hao; Xu GuoPing; Zhao Canhui

    2012-01-01

    Based on Edong Yangtze River Bridge, which is the second longest hybrid girder cable stayed bridge with 926 m long main span, the influencing factors and crucial techniques of the main span closure method for long span hybrid girder cable stayed bridge are studied. After theoretical analysis, numerical evaluation and practical test, the loading assistant closure method is employed in Edong Yangtze River Bridge. The loading assistant closure method, with better thermal adaptability and less influence on bridge line and the forced status, can meet the requirements of the unstressed state control method. Based on the mentioned advantages, the loading assistant closure method is applicable to long span hybrid girder cable stayed bridges. The conclusion can provide a reference for the further design of the similar brid~es.

  6. Diode-quad bridge circuit means

    Science.gov (United States)

    Harrison, D. R.; Dimeff, J. (Inventor)

    1975-01-01

    A transducer and frequency discriminator circuit is described including a four-terminal circulating diode bridge, a first pair of capacitors connected in series across two terminals of the bridge, and a second pair of capacitors, or other impedance elements, connected in series across the other two terminals of the bridge. A source of balanced alternating electrical energy for energizing the circuit is coupled between the commonly connected plates of the first pair of capacitors and the commonly connected plates of the second pair of capacitors. Due to the operation of the diode bridge, the sum of the resultant charges developed on the first pair of capacitors is proportional to the relationship between the respective capacitors of the second pair, and consequently, an output voltage taken across the first pair of capacitors will be proportional to that relationship.

  7. 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...

  8. 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...

  9. Relaxation of liquid bridge after droplets coalescence

    Directory of Open Access Journals (Sweden)

    Jiangen Zheng

    2016-11-01

    Full Text Available We investigate the relaxation of liquid bridge after the coalescence of two sessile droplets resting on an organic glass substrate both experimentally and theoretically. The liquid bridge is found to relax to its equilibrium shape via two distinct approaches: damped oscillation relaxation and underdamped relaxation. When the viscosity is low, damped oscillation shows up, in this approach, the liquid bridge undergoes a damped oscillation process until it reaches its stable shape. However, if the viscous effects become significant, underdamped relaxation occurs. In this case, the liquid bridge relaxes to its equilibrium state in a non-periodic decay mode. In depth analysis indicates that the damping rate and oscillation period of damped oscillation are related to an inertial-capillary time scale τc. These experimental results are also testified by our numerical simulations with COMSOL Multiphysics.

  10. Wheatstone bridge technique for magnetostriction measurements.

    Science.gov (United States)

    Sullivan, M

    1980-03-01

    A basic Wheatstone bridge, with additional electronic instrumentation, has been used in the measurement of magnetostriction. This method allows a resolution of approximately 10% on measurements of magnetostrictions less than 0.75 parts per million.

  11. VT Short Structures - Bridges and Culverts

    Data.gov (United States)

    Vermont Center for Geographic Information — Inspection data for structures (bridge and culvert) between 6 feet and 20 feet in length inspected on State road system. Stewards: Information Technology, Data...

  12. VT Long Structures - Bridges and Culverts

    Data.gov (United States)

    Vermont Center for Geographic Information — Inspection data for structures (bridge and culvert) greater than 20 feet in length inspected on both State and local road systems. Stewards: Information Technology,...

  13. Active Control of Long Bridges Using Flaps

    DEFF Research Database (Denmark)

    Hansen, H. I.; Thoft-Christensen, Palle

    The main problem in designing ultra-long span suspension bridges is flutter. A solution to this problem might be to introduce an active flap control system to increase the flutter wind velocity. The investigated flap control system consists of flaps integrated in the bridge girder so each flap...... is the streamlined part of the edge of the girder. Additional aerodynamic derivatives are shown for the flaps and it is shown how methods already developed can be used to estimate the flutter wind velocity for a bridge section with flaps. As an example, the flutter wind velocity is calculated for different flap...... configurations for a bridge section model by using aerodynamic derivatives for a flat plate. The example shows that different flap configurations can either increase or decrease the flutter wind velocity. for optimal flap configurations flutter will not occur....

  14. 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.

  15. 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.

  16. 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 ...

  17. 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

  18. 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.

  19. Waterborne Commerce of the United States, Calendar Year 1982. Part 2. Waterways and Harbors, Gulf Coast, Mississippi River System and Antilles.

    Science.gov (United States)

    1984-07-01

    TO THE MERHENTAU RIVER: AND WATERWAY FOD WHITE LAKE TO PECAN ISLAND. CONTRnL(I[",G DEPTH C"EAN LOW GULF?: tOWER MER "AI 00V", THROUGH GRAND LAKE, 3...450 4 . ....26,70. 29APHAT R ANYAEROR PIC............. 20,049%.,00 33237 90 20,6 .50 . 2690 COKE, A PERu COE. . . . 2,44,62 5 7 745?21a; 7 130949...3" - - -A "" ICA -On TE E ,- " ’ ",’ ’* 351t MACHTRV, EXCEPT EL" CTR

  20. 49 CFR 237.33 - Content of bridge management programs.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Content of bridge management programs. 237.33... Content of bridge management programs. Each bridge management program adopted in compliance with this part... spans, span lengths, and all other information necessary to provide for the management of bridge...

  1. 23 CFR 650.705 - Application for discretionary bridge funds.

    Science.gov (United States)

    2010-04-01

    ... TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Discretionary Bridge Candidate Rating Factor § 650... cost, current average daily truck traffic and a narrative describing the existing bridge, the proposed new or rehabilitated bridge and other relevant factors which the State believes may warrant...

  2. 33 CFR 118.80 - Lights on bascule bridges.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lights on bascule bridges. 118.80 Section 118.80 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.80 Lights on bascule bridges. (a) Lift span lights. Each lift span...

  3. 33 CFR 118.90 - Bridges crossing channel obliquely.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bridges crossing channel obliquely. 118.90 Section 118.90 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.90 Bridges crossing channel obliquely....

  4. 23 CFR 650.809 - Movable span bridges.

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Movable span bridges. 650.809 Section 650.809 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.809 Movable span bridges. A fixed...

  5. Detection of salt bridges to lysines in solution in barnase

    DEFF Research Database (Denmark)

    Hansen, Poul Erik; Williamson, Michael P.; Hounslow, Andrea M.

    2013-01-01

    We show that salt bridges involving lysines can be detected by deuterium isotope effects on NMR chemical shifts of the sidechain amine. Lys27 in the ribonuclease barnase is salt bridged, and mutation of Arg69 to Lys retains a partially buried salt bridge. The salt bridges are functionally important....

  6. 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...

  7. 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

    on the observed bridging mechanism, a micromechanical model is developed for the prediction of macroscopic mixed mode bridging laws (stress-opening laws). The model predicts a high normal stress for very small openings, decreasing rapidly with increasing normal and tangential crack opening displacements......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...

  8. 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....

  9. 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 Danish...... to the bridge and the stochastic nature of the surface roughness are included into the model....

  10. Earthquake Resistance of Integral Abutment Bridges

    OpenAIRE

    2009-01-01

    intermediate length bridges. Integral abutment construction eliminates joints and bearings which reduce long-term maintenance costs. However, in the absence of joints and bearings, the bridge abutments and foundations must be able to accommodate lateral movements from thermal expansion and contraction of the superstructure and from seismic events. Previous research has focused on the response to thermal expansion and contraction. The current research examines the response of integral abutment...

  11. Arch bridges – unlocking their potential

    OpenAIRE

    Long, Adrian; Nanukuttan, Sreejith

    2016-01-01

    Arch bridges are strong, durable, aesthetically pleasing and require little maintenance but very few have been built since the early 1900s. However, this trend has changed as more than 60 FlexiArch bridges have been installed since the system was launched in 2007. The FlexiArch uses precast concrete voussoirs, requires neither corrodible reinforcement, nor centring, can be installed in hours and is contractor friendly. Details of this innovative method of construction and installation of arch...

  12. 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.

  13. 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.

  14. I-5/Gilman advanced technology bridge project

    Science.gov (United States)

    Lanza di Scalea, Francesco; Karbhari, Vistasp M.; Seible, Frieder

    2000-04-01

    The UCSD led I-5/Gilman Advanced Technology Bridge Project will design and construct a fully functional traffic bridge of advanced composite materials across Interstate 5 in La Jolla, California. Its objective is to demonstrate the use of advanced composite technologies developed by the aerospace industry in commercial applications to increase the life expectancy of new structures and for the rehabilitation of aging infrastructure components. The structure will be a 450 ft long, 60 ft wide cable-stayed bridge supported by a 150 ft A-frame pylon with two vehicular lanes, two bicycle lanes, pedestrian walkways and utility tunnels. The longitudinal girders and pylon will be carbon fiber shells filled with concrete. The transverse deck system will consist of hollow glass/carbon hybrid tubes and a polypropylene fiber reinforced concrete deck with an arch action. Selected cables will be composite. The bridge's structural behavior will be monitored to determine how advanced composite materials perform in civil infrastructure applications. The bridge will be instrumented to obtain performance and structural health data in real time and, where possible, in a remote fashion. The sensors applied to the bridge will include electrical resistance strain gages, fiberoptic Bragg gratings and accelerometers.

  15. 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。

  16. A Tale of Five Bridges; the use of GNSS for Monitoring the Deflections of Bridges

    Science.gov (United States)

    Roberts, Gethin Wyn; Brown, Christopher J.; Tang, Xu; Meng, Xiaolin; Ogundipe, Oluropo

    2014-11-01

    The first Bridge Monitoring surveying was carried out in 1996 by the authors, through attaching Ashtech ZXII GPS receivers onto the Humber Bridge' parapet, and gathering and further analysing the resulting 1 Hz RTK GPS data. Various surveys have subsequently been conducted on the Humber Bridge, the Millennium Bridge, the Forth Road Bridge, the Severn Suspension Bridge and the Avonmouth Viaduct. These were all carried out using survey grade carrier phase/pseudorange GPS and later GNSS receivers. These receivers were primarily dual frequency receivers, but the work has also investigated the use of single frequency receivers, gathering data at 1 Hz, 10 Hz, 20 Hz and even 100 Hz. Various aspects of the research conducted are reported here, as well as the historical approach. Conclusions are shown in the paper, as well as lessons learnt during the development of this work. The results are compared to various models that exist of the bridges' movements, and compare well. The results also illustrate that calculating the frequencies of the movements, as well as looking at the magnitudes of the movements, is an important aspect of this work. It is also shown that in instances where the magnitudes of the movements of the bridge under investigation are small, it is still possible to derive very accurate frequencies of the movements, in comparison to the existing models.

  17. 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

  18. Keeping our waterways safe by equipping commercial vessels with appropriate sensor suites to enable pervasive surveillance of coastal and inland waterborne commercial traffic

    Science.gov (United States)

    Feeley, Terry; Lavoie, James

    2010-04-01

    The US has over 58,000 miles of ocean shoreline, over 5500 hundred miles of Great Lakes shoreline, and over 3,500,000 miles of river and small lake shoreline. These waterways are critical to the nation's strategic, economic and societal well being. These assets must be protected from potential terrorist attacks. It is a daunting task for an open society to protect such a large and distributed area while still preserving the freedoms for its citizens to enjoy the natural beauty of our waterways. The US has a well developed fleet of merchant tugs and barges that engage in day to day commercial activity around the coasts, rivers and lakes of the country. This paper will discuss the notion of developing a nationwide mobile sensor network by equipping these barges and tugs with sensor suites that would feed data into a common operations' center. The data will be displayed to the first responder community and the vessel operators via data streams from Rite-View (a robust 3D modeling and simulation tool).

  19. 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.

  20. Estimation Research on Freight Volume of New Inland Waterway%新建内河航道货运量预测研究

    Institute of Scientific and Technical Information of China (English)

    李莉; 吴峰; 杨尊伟

    2016-01-01

    结合小清河复航工程实例,根据腹地经济发展、交通运输结构等特点,首先通过产销平衡法初步预测小清河货运量,再采用货源调查法进一步预测小清河分货种货运量,通过综合分析得到小清河水平年总货运量.采用这种定量计算与定性分析相结合的方法预测结果较为合理,成果对缺乏历史数据的新建内河航道货运量预测有一定的参考价值.%By analyzing the waterway re-navigation project of Xiaoqing River, the economy development and transportation system of the hinterland, the freight volume of Xiaoqing River is firstly estimated by using the coordination method of supply and marketing. Then the volume of each specified cargo is further estimated by using goods supply investigation. The mean annual freight volume of Xiaoqing River is finally obtained by comprehensive analysis. The combination of qualitative analysis and quantitative calculation produces a reasonable estimated value. The research results serve as a certain reference for the estimation of freight volume of new inland waterways which lack historical data.

  1. 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)

  2. Iron(III) accumulations in inland saline waterways, Hunter Valley, Australia: Mineralogy, micromorphology and pore-water geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Isaacson, Lloyd S., E-mail: lisaac11@scu.edu.au [Southern Cross GeoSciences, Southern Cross University, Lismore, NSW 2480 (Australia); Burton, Edward D.; Bush, Richard T. [Southern Cross GeoSciences, Southern Cross University, Lismore, NSW 2480 (Australia); Mitchell, David R.G. [Australian Nuclear Science and Technology Organisation, Institute of Materials and Engineering Science, Menai, NSW 2234 (Australia); Electron Microscope Unit, University of Sydney, NSW 2006 (Australia); Johnston, Scott G. [Southern Cross GeoSciences, Southern Cross University, Lismore, NSW 2480 (Australia); Macdonald, Bennett C.T. [The Fenner School for Environment and Society, Australian National University, Canberra 0200 (Australia); Sullivan, Leigh A. [Southern Cross GeoSciences, Southern Cross University, Lismore, NSW 2480 (Australia); White, Ian [The Fenner School for Environment and Society, Australian National University, Canberra 0200 (Australia)

    2009-10-15

    Discharge of Fe(II)-rich groundwaters into surface-waters results in the accumulation of Fe(III)-minerals in salinized sand-bed waterways of the Hunter Valley, Australia. The objective of this study was to characterise the mineralogy, micromorphology and pore-water geochemistry of these Fe(III) accumulations. Pore-waters had a circumneutral pH (6.2-7.2), were sub-oxic to oxic (Eh 59-453 mV), and had dissolved Fe(II) concentrations up to 81.6 mg L{sup -1}. X-ray diffraction (XRD) on natural and acid-ammonium-oxalate (AAO) extracted samples indicated a dominance of 2-line ferrihydrite in most samples, with lesser amounts of goethite, lepidocrocite, quartz, and alumino-silicate clays. The majority of Fe in the samples was bound in the AAO extractable fraction (Fe{sup Ox}) relative to the Na-dithionite extractable fraction (Fe{sup Di}), with generally high Fe{sup Ox}:Fe{sup Di} ratios (0.52-0.92). The presence of nano-crystalline 2-line ferrihydrite (Fe{sub 5}HO{sub 3}.4H{sub 2}O) with lesser amounts of goethite ({alpha}-FeOOH) was confirmed by scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX), and transmission electron microscopy (TEM) coupled with selected area electron diffraction (SAED). In addition, it was found that lepidocrocite ({gamma}-FeOOH), which occurred as nanoparticles as little as {approx}5 lattice spacings thick perpendicular to the (0 2 0) lattice plane, was also present in the studied Fe(III) deposits. Overall, the results highlight the complex variability in the crystallinity and particle-size of Fe(III)-minerals which form via oxidation of Fe(II)-rich groundwaters in sand-bed streams. This variability may be attributed to: (1) divergent precipitation conditions influencing the Fe(II) oxidation rate and the associated supply and hydrolysis of the Fe(III) ion, (2) the effect of interfering compounds, and (3) the influence of bacteria, especially Leptothrix ochracea.

  3. 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.

  4. 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.

  5. Using rotating liquid bridges as accelerometers

    Energy Technology Data Exchange (ETDEWEB)

    Montanero, J.M. [Universidad de Extremadura, Badajoz (Spain). Dept. de Electronica e Ingenieria Electromecanica; Cabezas, G.; Acero, J.; Zayas, F.

    1999-07-01

    Liquid bridges have recently been proposed as fluid accelerometers that could be used to measure very small inertial forces under microgravity conditions [Meseguer et al., microgravity sci. technol. IX/2 (1996)]. The essential idea is to infer the values of such inertial forces from the liquid bridge interface contour, whose shape obviously depends on the values of such forces (apart from the bridge volume and the geometry of the supporting disks). Following a similar procedure, in this paper we explore the use of rotating axisymmetric liquid bridges to measure the residual axial gravity and the rotation rate of the liquid bridge regarded as a solid body. In light off the difficulties involved in performing experiments on Earth, the role of empirical data is played by an accurate numerical solution of the Young-Laplace equation. The values of both the axial gravity and angular speed are obtained by fitting the approximate analytical expressions derived in this paper to the numerical solution of the Young-Laplace equation. The comparison between the predicted and actual values of the variables of interest shows a satisfactory agreement, supporting the suitability of the procedure. (orig.)

  6. Heavy Vehicles on Minor Highway Bridges

    DEFF Research Database (Denmark)

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

    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...... projects at a minimum, it is necessary to perform accurate estimates of the dynamic amplification factor (defined as the dynamic load effect divided by the static load effect from the vehicles), so this quantity is neither over- nor underestimated. The principal aims of the present paper are to establish...... 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....

  7. Ergonomic aspects of automation in navigation bridges.

    Science.gov (United States)

    Lazet, A; Walraven, P L

    1971-06-01

    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 efficient, good ergonomic design is essential. A series of designs of navigation bridges is used to illustrate typical problems and situations. The building of full scale mock-ups of complete bridges is essential in order to handle the design as an integrated problem and to simulate the work situation. Such static mock-ups have been shown to be extremely useful in the discussion between builder, future user and adviser. An extension to dynamic simulation is necessary in order to study the actual work conditions in a new design.

  8. 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....... The determination of these force coefficients require a proper simulation of the ice layer occurring under the specific climatic conditions, favouring real ice accretion over simplified artificial reproduction. The work presented in this paper was performed to study the influence of ice accretion on the aerodynamic...

  9. Stability of dynamic response of suspension bridges

    Science.gov (United States)

    Capsoni, Antonio; Ardito, Raffaele; Guerrieri, Andrea

    2017-04-01

    The potential occurrence of internal parametric resonance phenomena has been recently indicated as a potential contributory cause of the appearance of critical dynamic states in long-span suspension bridges. At the same time, suspension bridges, in view of their flexibility, are prone to aeroelastic response, such as vortex shedding, torsional divergence and flutter. In this paper, a non-linear dynamic model of a suspension bridge is devised, with the purpose of providing a first attempt toward a unified framework for the study of aeroelastic and internal resonance instabilities. Inspired by the pioneering work of Herrmann and Hauger, the analyses have been based on a linearized formulation that is able to represent the main structural non-linear effects and the coupling given by aerodynamic forces. The results confirm that the interaction between aeroelastic effects and non-linear internal resonance leads to unstable conditions for wind speeds which can be lower than the critical threshold for standard aeroelastic predictions.

  10. Building bridges within the bacterial chromosome.

    Science.gov (United States)

    Song, Dan; Loparo, Joseph J

    2015-03-01

    All organisms must dramatically compact their genomes to accommodate DNA within the cell. Bacteria use a set of DNA-binding proteins with low sequence specificity called nucleoid-associated proteins (NAPs) to assist in chromosome condensation and organization. By bending or bridging DNA, NAPs also facilitate chromosome segregation and regulate gene expression. Over the past decade, emerging single-molecule and chromosome conformation capture techniques have investigated the molecular mechanisms by which NAPs remodel and organize the bacterial chromosome. In this review we describe how such approaches reveal the biochemical mechanisms of three NAPs that are believed to facilitate DNA bridging: histone-like nucleoid structuring protein (H-NS), ParB, and structural maintenance of chromosomes (SMC). These three proteins form qualitatively different DNA bridges, leading to varied effects on transcription and chromosome segregation.

  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. Operational modal analysis of road-rail bridge

    OpenAIRE

    Cardoso M.; Sampaio R. A. C.; de Souza R. M.; Silva E.

    2015-01-01

    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 ...

  14. 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

  15. Dragon bridge - the world largest dragon-shaped (ARCH steel bridge as element of smart city

    Directory of Open Access Journals (Sweden)

    Chinh Luong Minh

    2016-01-01

    Full Text Available Dragon Bridge - The world’s largest dragon-shaped steel bridge, with an installation cost of $85 million USD, features 6 lanes for two separate directions, 666 meters of undulating steel in the shape of a dragon in the Ly Dynasty, the symbol of prosperity in Vietnamese culture. This unique and beautifully lit bridge, which also breathes fire and sprays water. It’s the purposeful integration of the lighting hardware articulates the dragon’s form, and the fire-breathing dragon head. This project transcends the notion of monumental bridge with dynamic colour-changing lighting, creating an iconic sculpture in the skyline that is both reverent and whimsical. The signature feature of the bridge was the massive undulating support structure resembling a dragon flying over the river. The dragon is prominent in Vietnamese culture as a symbol of power and nobility. Dragon Bridge stands out as a model of innovation. It has received worldwide attention in the design community and from the global media for its unique arch support system. Dragon Bridge serves as an example of how aesthetic quality of a design can serve cultural, economic and functional purposes. The article presents design solutions of the object and the evaluation of the technical condition before putting the facility into service.

  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. 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.

  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. 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.

  20. 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....

  1. Analysis of Biaxially Stressed Bridge Deck Plates

    DEFF Research Database (Denmark)

    Jönsson, Jeppe; Bondum, Tommi Højer

    2012-01-01

    The ultimate state analysis of bridge deck plates at the intersection zone between main girders and transverse beams is complicated by biaxial membrane stresses, which may be in compression or tension in either direction depending on the bridge configuration and the specific location. This paper...... presents a detailed investigation of the ultimate capacity of simply supported plates subjected to biaxial loads. The full interaction domain of combinations of compressive and tensile loads has been investigated including a large number of imperfections. It was found that non-standard imperfection modes...

  2. Construction Technology of Long Span Bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    2000-01-01

    A large variety of construction methods are used during construction of major bridges, and in many cases the final structural system must be chosen with due respect to the construction process. Today the preferred construction methods are: the free-cantilever method, the launching method and the ......A large variety of construction methods are used during construction of major bridges, and in many cases the final structural system must be chosen with due respect to the construction process. Today the preferred construction methods are: the free-cantilever method, the launching method...

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. Experimental investigation of different fill materials in arch bridges with particular focus on Pearl-Chain Bridges

    DEFF Research Database (Denmark)

    Lund, Mia Schou Møller; Hansen, Kurt Kielsgaard; Hertz, Kristian Dahl

    2016-01-01

    Pearl-Chain Bridge technology is a recently developed prefabricated arch solution for road and railway bridges allowing faster, more environmentally friendly, and cheaper bridge construction. This study compared the strength and durability properties of three different types of fill material...... to find the most optimal fill for Pearl-Chain Bridges. Sub-base gravel, cement-stabilized gravel, and pervious concrete were tested with respect to compressive strength, stiffness, splitting tensile strength, permeability, freeze–thaw durability, and shrinkage. This paper summarizes the advantages...... and disadvantages of implementing the different types of fill material in arch bridges, particularly in Pearl-Chain Bridges....

  8. Bridge Influence Line Estimation for Bridge Weigh-in-Motion System

    OpenAIRE

    Ieng, Sio Song

    2015-01-01

    This paper presents an algorithm that estimates the influence line (IL) of a bridge using data collected when trucks pass over the sensors installed in the bridge. The algorithm is tested with data collected from the Millau Viaduct in France using a bridge weigh-in-motion (B-WIM) device. The algorithm uses the maximum likelihood estimation (MLE) and is compared with an old algorithm. The algorithm is more robust because it takes into account many signals for the estimation of the IL.

  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. 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 ...

  11. 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,...

  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. 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

  14. 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,…

  15. Images Bridging Home and Academic Cultures.

    Science.gov (United States)

    Andres, Sophia

    Often students are unable to draw upon their personal worlds and individual experiences to enrich their writing, suggesting a disparity between home and academic cultures. In light of this apparent disparity, teachers must try to bridge the gap, a task that is possible when the teacher focuses on the germinal, emotional, and unifying qualities of…

  16. 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...

  17. 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.

  18. New Program Builds Bridges for Hearing Impaired.

    Science.gov (United States)

    Johnson, Jeannie

    1998-01-01

    Describes a new approach to teaching English-as-a-Second-Language to New Mexico elementary school students who have hearing impairments and whose dominant language is American Sign Language (ASL). These students must first acquire ASL as a bridge to learning English. Then, using the bilingual approach, they are able to focus on English literacy.…

  19. 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

  20. 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.

  1. 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...

  2. Bridge monitoring using heterogeneous wireless sensor network

    Science.gov (United States)

    Haran, Shivan; Kher, Shubhalaxmi; Mehndiratta, Vandana

    2010-03-01

    Wireless sensor networks (WSN) are proving to be a good fit where real time monitoring of multiple physical parameters is required. In many applications such as structural health monitoring, patient data monitoring, traffic accident monitoring and analysis, sensor networks may involve interface with conventional P2P systems and it is challenging to handle heterogeneous network systems. Heterogeneous deployments will become increasingly prevalent as it allows for systems to seamlessly integrate and interoperate especially when it comes to applications involving monitoring of large infrastructures. Such networks may have wireless sensor network overlaid on a conventional computer network to pick up data from one distant location and carry out the analysis after relaying it over to another distant location. This paper discusses monitoring of bridges using WSN. As a test bed, a heterogeneous network of WSN and conventional P2P together with a combination of sensing devices (including vibration and strain) is to be used on a bridge model. Issues related to condition assessment of the bridge for situations including faults, overloads, etc., as well as analysis of network and system performance will be discussed. When conducted under controlled conditions, this is an important step towards fine tuning the monitoring system for recommendation of permanent mounting of sensors and collecting data that can help in the development of new methods for inspection and evaluation of bridges. The proposed model, design, and issues therein will be discussed, along with its implementation and results.

  3. 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.

  4. 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....

  5. 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.

  6. 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.

  7. 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 (city),...

  8. 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

  9. 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...

  10. 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

  11. 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

  12. A calculation model for the noise from steel railway bridges

    NARCIS (Netherlands)

    Janssens, M.H.A.; Thompson, D.J.

    1996-01-01

    The sound level of a train crossing a steel railway bridge is usually about 10 dB higher than on plain track. In the Netherlands there are many such bridges which, for practical reasons, cannot be replaced by more intrinsically quiet concrete bridges. A computational model is described for the estim

  13. 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...

  14. 33 CFR 115.50 - Application for bridge permits.

    Science.gov (United States)

    2010-07-01

    ... authority not necessary. Coast Guard approval of the location and plans for construction or modification of a bridge or causeway is not required for any bridge or causeway over waters which are not subject to... (historic use). This provision does not apply to bridges which connect the United States with any...

  15. 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 factors...

  16. 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...

  17. Seismic Performance of Multi-Span RC Railway Bridges

    DEFF Research Database (Denmark)

    Georgakis, Christos; Barrau, Xavier

    2008-01-01

    Presently, there is no clear method for determining the optimal railway bridge design for a particular ground type and expected seismic intensity. Four main types of RC bridge dominate the current multi-span railway bridge design trends – the Simply Supported Beam, Continuous Box-Girder (CBG), CBG...

  18. 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

  19. 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...

  20. Reliability-Based Optimization for Maintenance Management in Bridge Networks

    OpenAIRE

    Hu, Xiaofei

    2014-01-01

    This dissertation addresses the problem of optimizing maintenance, repair and reconstruction decisions for bridge networks. Incorporating network topologies into bridge management problems is computationally difficult. Because of the interdependencies among networked bridges, they have to be analyzed together. Simulation-based numerical optimization techniques adopted in past research are limited to networks of moderate sizes. In this dissertation, novel approaches are developed to dete...

  1. 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...

  2. Morphometric parameters and level of Salmonella and Escherichia coli contamination of Tilapia guineensis and Sarotherodon melanotheron in the waterway of Southern Benin

    Directory of Open Access Journals (Sweden)

    Tossou Jacques Dougnon

    2016-02-01

    Full Text Available Aim: The present study aims to evaluate the morphometric parameters and level of Salmonella and Escherichia coli contamination of Tilapia guineensis and Sarotherodon melanotheron in the waterway of Southern Benin. Materials and Methods: 183 T. guineensis and 195 S. melanotheron were collected from June to July 2014 in four waterways: Lake Ahémé, Nokoué Lake, coastal lagoon, and lagoon of Porto-Novo. Weight, total length, and standard length of these fish were evaluated. E. coli and Salmonella sp. were sought in fresh fish. Results: The results obtained in this study indicate that S. melanotheron presented high-performance of length and weight more than T. guineensis in Ahémé Lake and lagoon of Porto-Novo. However, in Nokoué Lake and coastal lagoon, no difference was observed between the two species of fish. As for bacteriological analysis, the population of T. guineensis was more contaminated with E. coli with respective values of 60% and 59.52% in the Nokoué Lake and coastal lagoon than in the two other streams. Regarding the population of S. melanotheron, she was most contaminated in the coastal lagoon with a percentage of 66.66% in Ahémé Lake, Nokoué Lake, and the lagoon of Porto-Novo. However, no Salmonella germ was detected in fish analyzed in this study. Conclusion: It appears that the morphometric parameters and weight of T. guineensis are lower than those of S. melanotheron. The evaluation of the microbiological quality revealed that T. guineensis is more contaminated with E. coli that S. melanotheron.

  3. 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.

  4. 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.

  5. An effective Handling of Thermal Bridges in the EPBD Context

    DEFF Research Database (Denmark)

    Erhorn, Hans; Erhorn-Kluttig, Heike; Thomsen, Kirsten Engelund;

    The ASIEPI project has collected and analysed international and national information from up to 17 EU Member States plus Norway on the topic of thermal bridges in buildings. Seven different aspects have been addressed, ranging from EU Member States’ approaches in regulations to quantification...... of thermal bridge effects to the energy balance, used software tools and thermal bridge atlases, available good practice guidance and promotion of good building practice to the execution quality and advanced thermal bridge driven technical developments. This report presents the gathered knowledge, draws...... junctions and other building parts with possible thermal bridges....

  6. 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...

  7. Dynamics and statics of nonaxisymmetric and symmetric liquid bridges

    Science.gov (United States)

    Alexander, J. Iwan D.; Resnick, Andrew H.; Kaukler, William F.; Zhang, Yiqiang

    1994-01-01

    This program of theoretical and experimental ground-based research focuses on the understanding of the dynamics and stability limits of nonaxisymmetric and symmetric liquid bridges. There are three basic objectives: First, to determine the stability limits of nonaxisymmetric liquid bridges held between non-coaxial parallel disks, Second, to examine the dynamics of nonaxisymmetric bridges and nonaxisymmetric oscillations of initially axisymmetric bridges. The third objective is to experimentally investigate the vibration sensitivity of liquid bridges under terrestrial and low gravity conditions. Some of these experiments will require a low gravity environment and the ground-based research will culminate in a definitive flight experiment.

  8. 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.

  9. Polymeric salt bridges for conducting electric current in microfluidic devices

    Science.gov (United States)

    Shepodd, Timothy J.; Tichenor, Mark S.; Artau, Alexander

    2009-11-17

    A "cast-in-place" monolithic microporous polymer salt bridge for conducting electrical current in microfluidic devices, and methods for manufacture thereof is disclosed. Polymeric salt bridges are formed in place in capillaries or microchannels. Formulations are prepared with monomer, suitable cross-linkers, solvent, and a thermal or radiation responsive initiator. The formulation is placed in a desired location and then suitable radiation such as UV light is used to polymerize the salt bridge within a desired structural location. Embodiments are provided wherein the polymeric salt bridges have sufficient porosity to allow ionic migration without bulk flow of solvents therethrough. The salt bridges form barriers that seal against fluid pressures in excess of 5000 pounds per square inch. The salt bridges can be formulated for carriage of suitable amperage at a desired voltage, and thus microfluidic devices using such salt bridges can be specifically constructed to meet selected analytical requirements.

  10. 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...

  11. 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.

  12. 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.

  13. 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.

  14. Skin bridging secondary to ingrown toenail.

    Science.gov (United States)

    Dadaci, Mehmet; Ince, Bilsev; Altuntas, Zeynep; Kamburoglu, Haldun Onuralp; Bitik, Ozan

    2014-01-01

    Ingrown toenails are painful conditions that especially affect young people and may become chronic if not treated. We describe a case of chronically inflamed ingrown toenail left untreated for three years. In the physical examination, skin bridging and epithelialization was observed in midline secondary to soft tissue hypertrophy of the lateral nail matrixes. Epithelized fibrous tissue was cut across the lateral nail matrix and left for secondary healing. Partial matrixectomy was applied and the remnants were cauterized in compliance with the Winograd procedure after removal of the nail. Our case is an advanced condition which is the second report in the literature. Skin bridging secondary to excess soft tissue hypertrophy can be observed in untreated bilateral Heinfert or Frost stage 3 ingrown nails. This rare case can be classified as advanced stage 3 disease or stage 4.

  15. Accelerated Aging of Polymer Composite Bridge Materials

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Nancy Margaret; Blackwood, Larry Gene; Torres, Lucinda Laine; Rodriguez, Julio Gallardo; Yoder, Timothy Scott

    1999-03-01

    Accelerated aging research on samples of composite material and candidate ultraviolet (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 (INEEL). Durability results and sensor data from tests 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.

  16. 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.

  17. Impact Coefficient Analysis of Long-Span Railway Cable-Stayed Bridge Based on Coupled Vehicle-Bridge Vibration

    OpenAIRE

    Yongle Li; Shifu Dong; Yulong Bao; Kejian Chen; Shizhong Qiang

    2015-01-01

    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 vehi...

  18. Skin bridging secondary to ingrown toenail

    OpenAIRE

    Dadaci, Mehmet; Ince, Bilsev; Altuntas, Zeynep; Kamburoglu, Haldun Onuralp; Bitik, Ozan

    2014-01-01

    Ingrown toenails are painful conditions that especially affect young people and may become chronic if not treated. We describe a case of chronically inflamed ingrown toenail left untreated for three years. In the physical examination, skin bridging and epithelialization was observed in midline secondary to soft tissue hypertrophy of the lateral nail matrixes. Epithelized fibrous tissue was cut across the lateral nail matrix and left for secondary healing. Partial matrixectomy was applied and ...

  19. 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.

  20. COLLISIONS OF ROAD VEHICLES WITH BRIDGE COLUMNS

    OpenAIRE

    2015-01-01

    As speed limits and traffic on city roads continue to increase, collisions between road vehicles and bridge columns are becoming more common. Current regulations analyze collision with one major simplification: replacing dynamic action with the equivalent static force. In the present paper, we develop a numerical model of a typical Croatian overpass and loaded it with an equivalent static load according to the EN1991-7 and ASSHTO LRFD provisions, analyzing the differences in overpass behavior...

  1. Structural characterization of thioether-bridged bacteriocins.

    Science.gov (United States)

    Lohans, Christopher T; Vederas, John C

    2014-01-01

    Bacteriocins are a group of ribosomally synthesized antimicrobial peptides produced by bacteria, some of which are extensively post-translationally modified. Some bacteriocins, namely the lantibiotics and sactibiotics, contain one or more thioether bridges. However, these modifications complicate the structural elucidation of these bacteriocins using conventional techniques. This review will discuss the techniques and strategies that have been applied to determine the primary structures of lantibiotics and sactibiotics. A major challenge is to identify the topology of thioether bridges in these peptides (i.e., which amino-acid residues are involved in which bridges). Edman degradation, NMR spectroscopy and tandem MS have all been commonly applied to characterize these bacteriocins, but can be incompatible with the post-translational modifications present. Chemical modifications to the modified residues, such as desulfurization and reduction, make the treated bacteriocins more compatible to analysis by these standard peptide analytical techniques. Despite their differences in structure, similar strategies have proved useful to study the structures of both lantibiotics and sactibiotics.

  2. Communication through molecular bridges: different bridge orbital trends result in common property trends.

    Science.gov (United States)

    Proppe, Jonny; Herrmann, Carmen

    2015-02-05

    Common trends in communication through molecular bridges are ubiquitous in chemistry, such as the frequently observed exponential decay of conductance/electron transport and of exchange spin coupling with increasing bridge length, or the increased communication through a bridge upon closing a diarylethene photoswitch. For antiferromagnetically coupled diradicals in which two equivalent spin centers are connected by a closed-shell bridge, the molecular orbitals (MOs) whose energy splitting dominates the coupling strength are similar in shape to the MOs of the dithiolated bridges, which in turn can be used to rationalize conductance. Therefore, it appears reasonable to expect the observed common property trends to result from common orbital trends. We illustrate based on a set of model compounds that this assumption is not true, and that common property trends result from either different pairs of orbitals being involved, or from orbital energies not being the dominant contribution to property trends. For substituent effects, an effective modification of the π system can make a comparison difficult.

  3. Development of bridge management system (BMS); Bridge Management System (BMS) no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, A.; Kushida, M. [Yamaguchi University, Yamaguchi (Japan). Faculty of Engineering; Adachi, Y. [Hanshin Expressway Public Corp., Osaka (Japan); Matsumoto, M. [Kobe University, Kobe (Japan)

    1997-03-20

    With an objective to develop a bridge management system (BMS) which can execute overall management of road networks, discussions were given on the subject taking advantage of a result of the output from a concrete bridge diagnosis expert system. As its first step, a certain bridge was noticed to discuss an optimal maintenance and management measure which takes into consideration the safety, economic efficiency, functionality, and environmentality. The system has made it possible to estimate deterioration of the bridge after repair and reinforcement by proposing a deterioration curve and setting different hypotheses as a method to forecast performance deterioration of bridge members. Necessity of repair and reinforcement at the time of checking was determined from the result of an output from the expert system to select a construction method. A scheduled number of service years is set, all of the combinations of maintenance and management measures which satisfy the scheduled service life were retrieved, and an optimal maintenance and management measure was indicated, whose total cost is minimum among the proposed measures. Applying this MBS is capable to some extent of evaluating the effect of executing different measures and making economical optimization. 15 refs., 12 figs., 18 tabs.

  4. 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).

  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. 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.

  7. 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.

  8. 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.

  9. 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...

  10. 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.

  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. 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

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

    DEFF Research Database (Denmark)

    Hansen, Henriette I.; Thoft-Christensen, Palle

    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......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...... 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....

  14. Measurements of bridges' vibration characteristics using a mobile phone

    Directory of Open Access Journals (Sweden)

    Z. M. C. Pravia

    Full Text Available ABSTRACTThis research presents an alternative way to perform a bridge inspection, which considers the dynamics parameters from the structure. It shows an experimental phase with use of a mobile phone to extract the accelerations answers from two concrete bridges, from those records is feasible to obtain natural frequencies using the Fast Fourier Transform (FFT.Numerical models with uses finite element model (FEM allow to determine the natural frequencies from the two concrete bridges and compare with the experimental phase of each one. The final results shows it's possible to use mobiles phones to extract vibration answers from concrete bridges and define the structural behavior of bridges from natural frequencies, this procedure could be used to evaluate bridges with lower costs.

  15. 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.

  16. 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.

  17. Smart suspension systems for bridge-friendly vehicles

    Science.gov (United States)

    Chen, Yonghong; Tan, Chin An; Bergman, Larry A.; Tsao, T. C.

    2002-06-01

    In this paper, the effects of using semi-active control strategy (such as MR dampers) in vehicle suspensions on the coupled vibrations of a vehicle traversing a bridge are examined in order to develop various designs of smart suspension systems for bridge-friendly vehicles. The bridge-vehicle coupled system is modeled as a simply supported beam traversed by a two-degree-of-freedom quarter-car model. The surface unevenness on the bridge deck is modeled as a deterministic profile of a sinusoidal wave. As the vehicle travels along the bridge, the system is excited as a result of the surface unevenness and this excitation is characterized by a frequency defined by the speed of travel and the wavelength of the profile. The dynamic interactions between the bridge and the vehicle due to surface deck irregularities are obtained by solving the coupled equations of motion. Numerical results of a passive control strategy show that, when the lower natural frequency of the vehicle matches with a natural frequency (usually the first frequency) of the bridge and the excitation frequency, the maximum response of the bridge is large while the response of the vehicle is relatively smaller, meaning that the bridge behaves like a vibration absorber. This is undesirable from a bridge design viewpoint. Comparative studies of passive and semi-active controls for the vehicle suspension are performed. It is demonstrated that skyhook control can significantly mitigate the response of the bridge, while ground-hook control reduces the tire force impacted onto the bridge.

  18. Global Bridges: building an international network for tobacco dependence treatment

    Directory of Open Access Journals (Sweden)

    Katie Kemper

    2016-03-01

    Full Text Available Global Bridges, hosted at Mayo Clinic, is the most diverse international network of healthcare professionals dedicated to tobacco dependence treatment. Global Bridges works with grantees and partners in all six WHO regions to educate healthcare providers on evidence-based treatment and advocate for effective tobacco policy. This session will describe accomplishments and lessons learned in the Global Bridges program over nearly six years, and opportunities to better integrate cessation support into comprehensive tobacco control.

  19. A NEW APPROACH OF DIGITAL BRIDGE SURFACE MODEL GENERATION

    OpenAIRE

    Ju, H.

    2012-01-01

    Bridge areas present difficulties for orthophotos generation and to avoid “collapsed” bridges in the orthoimage, operator assistance is required to create the precise DBM (Digital Bridge Model), which is, subsequently, used for the orthoimage generation. In this paper, a new approach of DBM generation, based on fusing LiDAR (Light Detection And Ranging) data and aerial imagery, is proposed. The no precise exterior orientation of the aerial image is required for the DBM generation. First, a co...

  20. Bridges of the sella turcica - anatomy and topography.

    Science.gov (United States)

    Skrzat, Janusz; Mroz, Izabela; Marchewka, Justyna

    2012-01-01

    This paper presents anatomy and topography of the inconstant osseous bridges that may occur in the sella turcica region. The interclinoid bridge and the caroticoclinoid bridge can be formed in consequence of abnormal ossification of the dural folds or disturbances in development of the sphenoid bone. Their presence may be of clinical importance because of potential influence on the neurovascular structures passing in the vicinity of the clinoid processes of the sphenoid bone.

  1. 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.

  2. 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.

  3. NDE of composite seismic retrofits to bridges

    Science.gov (United States)

    Johnson, E. C.; Nokes, J. P.; Hawkins, G. F.

    1999-12-01

    Composite materials are being used for bridge column seismic retrofits and to rehabilitate other concrete structures. There are three different manufacturing methods for applying composites to concrete columns which are outlined in this paper. Each method has the potential for creating debonds at the composite-concrete interface and within the composite itself. Thermography is a non-destructive evaluation technique which can be used to image debonds below the composite surface. Data from thermographic tests of a variety of retrofit applications, which include examples for each of the three aforementioned manufacturing processes, are presented.

  4. 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. 

  5. 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.

  6. International Contribution to the Highway Agency's Bridge Related Research

    DEFF Research Database (Denmark)

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

    The objective of this paper is to summarize recent contributions of international experts to the research program sponsored by the Highways Agency. An efficient management of existing bridges requires methodology for an accurate evaluation of the actual loads and load carrying capacity and predic......The objective of this paper is to summarize recent contributions of international experts to the research program sponsored by the Highways Agency. An efficient management of existing bridges requires methodology for an accurate evaluation of the actual loads and load carrying capacity...... of reliability models for analysis of bridges subjected to corrosion and fatigue, and reliability-based optimization of maintenance strategies for bridges....

  7. 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.

  8. 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...

  9. Bridging of Calixarenes with N,N'-Bis(Chloroacetyl)Propylenediamine

    Institute of Scientific and Technical Information of China (English)

    LI Jun; WANG Wei; GONG shu-ling; CHEN Yuan-yin

    2004-01-01

    A new bridging reagent, N,N′-bis(chloroacetyl)propylenediamine was used to explore the relative activity and bridging pattern of p-tert-butylcalix[4]arene, p-tert-butylcalix[6]arene and butylcalix[8]arene. It was found that the bridging reaction is selectively, at least, preferably at 1,3-position for p-tert-butylcalix[4]arene and p-tert-butylcalix[6]arene, 1,5-position for p-tert-butylcalix[8]arene. Taking the yield of bridged calixarene as a comparsion standard, the activity decreases with the increasing of the number of phenolic units in calixarene.

  10. Research on Local Scour at Bridge Pier under Tidal Action

    Directory of Open Access Journals (Sweden)

    Wang Jianping

    2015-01-01

    Full Text Available Through the local scour test at bridge pier under tidal action in a long time series, this paper observes the growing trend of the deepest point of local scour at bridge pier under tidal conditions with different characteristic parameters, analyzes the impact of repeat sediment erosion and deposition in the scouring pit caused by reversing current on the development process of the scouring pit, and clarifies the relation between the tide and local scouring depth at bridge pier under steady flow conditions, so as to provide a scientific basis for bridge design and safe operation of estuary and harbor areas.

  11. Determination Method of Bridge Rotation Angle Response Using MEMS IMU

    Directory of Open Access Journals (Sweden)

    Hidehiko Sekiya

    2016-11-01

    Full Text Available To implement steel bridge maintenance, especially that related to fatigue damage, it is important to monitor bridge deformations under traffic conditions. Bridges deform and rotate differently under traffic load conditions because their structures differ in terms of length and flexibility. Such monitoring enables the identification of the cause of stress concentrations that cause fatigue damage and the proposal of appropriate countermeasures. However, although bridge deformation monitoring requires observations of bridge angle response as well as the bridge displacement response, measuring the rotation angle response of a bridge subject to traffic loads is difficult. Theoretically, the rotation angle response can be calculated by integrating the angular velocity, but for field measurements of actual in-service bridges, estimating the necessary boundary conditions would be difficult due to traffic-induced vibration. To solve the problem, this paper proposes a method for determining the rotation angle response of an in-service bridge from its angular velocity, as measured by a inertial measurement unit (IMU. To verify our proposed method, field measurements were conducted using nine micro-electrical mechanical systems (MEMS IMUs and two contact displacement gauges. The results showed that our proposed method provided high accuracy when compared to the reference responses calculated by the contact displacement gauges.

  12. 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.

  13. On the identification of liquid surface properties using liquid bridges.

    Science.gov (United States)

    Kostoglou, M; Karapantsios, T D

    2015-08-01

    The term liquid bridge refers to the specific silhouette of a liquid volume when it is placed between two solid surfaces. Liquid bridges have been studied extensively both theoretically and experimentally during the last century due to their significance in many technological applications. It is worth noticing that even today new technological applications based on liquid bridges continue to appear. A liquid bridge has a well-defined surface configuration dictated by a rigid theoretical foundation so the potential of its utilization as a tool to study surface properties of liquids is apparent. However, it is very scarce in literature that the use of liquid bridges is suggested as an alternative to the well-established drop techniques (pendant/sessile drop). The present work (i) presents the theoretical background for setting up a liquid-bridge based surface property estimation problem, (ii) describes the required experimental equipment and procedures and (iii) performs a thorough literature review on the subject. A case with particular interest is that of liquid bridges made of electrically conducting liquids forming between two conducting solids; such a liquid bridge presents an integral electrical conductance value which is sensitive to the specific silhouette of the bridge. This enables the use of this integral conductance as shape descriptor instead of the conventional image processing techniques. Several attempts in literature for the estimation of liquid surface tension, liquid-solid contact angle and surfactant induced surface elasticity for conducting or non/conducting liquids are presented and the prospects of the technique are discussed.

  14. 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.

  15. 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.

  16. The Bridge and the Troll Underneath: Summer Bridge Programs and Degree Completion

    Science.gov (United States)

    Douglas, Daniel; Attewell, Paul

    2014-01-01

    College graduation rates in the United States are low in both real and relative terms. This has left all stakeholders looking for novel solutions while perhaps ignoring extant but underused programs. This article examines the effect of "summer bridge" programs, which have students enroll in coursework prior to beginning their first full…

  17. Bridge to Success: Insight into Summer Bridge Program Students' College Transition

    Science.gov (United States)

    Walpole, MaryBeth; Simmerman, Herb; Mack, Cathy; Mills, John T.; Scales, Michael; Albano, Donna

    2008-01-01

    This study examines the college transition of students who participated in a summer bridge program. Three surveys collected longitudinal data on these students' aspirations and academic and social activities. Data provided from institutional research on their academic progress were also analyzed. A control group composed of non-participating…

  18. 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.

  19. 磨刀门水道盐水强烈上溯规律和动力机制研究%Research of Law and Dynamic Mechanism for Strong Sa-line Water Intrusion in Modaomen Waterway

    Institute of Scientific and Technical Information of China (English)

    包芸; 刘杰斌; 任杰; 许炜铭; 戚志明

    2009-01-01

    通过流体力学场的概念做出磨刀门水道成界图,得到3个月长时间序列的盐水运动上溯距离和潮位的关系,从中发现总是在潮差最小的前后两天盐水上溯有一个突然增加的特点.从2005年初实测资料中整理分析发现,在整个珠江上游径流量较小时,由于分流比的变化,磨刀门水道在小潮期间有两天净泄量几乎为零,从而导致涨落潮的流动状态发生显著变异,涨潮历时为16 h,落潮历时仅为9 h.在此动力作用下盐水快速上溯,随后几天由于小潮期间潮汐动力作用不大,使得盐水滞留在磨刀门水道,直到大潮期间较强的潮汐动力作用将盐水带出,因而造成磨刀门水道异常的盐水上溯规律和严重的咸潮灾害.%Depend on the concept of fluid field, the salinity borderline figure of Modaomen waterway was made, and the relationship between saltwater movement distance and tidal elevation with three months long time series was gotten. The feature that the intrusion strength of saltwater always suddenly increased during the two days before and after time of the smallest tidal range was found. In the analysis of observed data in early 2005, net discharge amount of Modaomen waterway was found to be almost zero during neap tides because of the change of diversion ratio when the small Pearl River runoff, so that the flow state had notable variation that the flood duration had 16 hours and the ebb duration had only 9 hours. Affected by these dynamics, saltwater invaded rapidly. Later a few days during neap tides saltwater remained in Modaomen waterway due to the small tidal dynamic role, until spring tides saltwater was out of Modaomen waterway step by step due to the strong tidal dynamic role. Therefore, the abnormal law of saltwater intrusion was formed and the serious saline intrusion disaster was occurred in the Modaomen waterway.

  20. 23 CFR 650.805 - Bridges not requiring a USCG permit.

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Bridges not requiring a USCG permit. 650.805 Section 650... OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.805 Bridges not... permit is not required for bridge construction. This determination shall be made at an early stage...

  1. 33 CFR 118.110 - Daymarks and lateral lighting on bridges.

    Science.gov (United States)

    2010-07-01

    ... bridges. 118.110 Section 118.110 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.110 Daymarks and lateral lighting on bridges. (a... through bridges with U.S. aids to navigation system lateral marks and lights installed on...

  2. 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.

  3. FBG application in bridge health monitoring system of Wuhan Yangtze River 2nd Bridge

    Science.gov (United States)

    Liu, Jun

    2009-10-01

    For the traditional resistance strain sensor's shortage,for example,their stability,durability and monitoring scorpe could not satisfied the requirement of bridge monitoring system,put forward to adopt advanced fiber-optic bragg grating sensor and its technology to build up the bridge health monitoring system.Analysed the application scope and aim of difference kinds of fiber bragg grating sensors used, including stress strain sensors,temperature sensors,crack sensors and testing force ring sensors.According to the key construction sections as the project designed,expatiated their specific installation methods and construction craftwork in Wuhan Yangtze River 2th bridge.It formed distributed fiber sensing network of bridge with large-scale located fiber-optic bragg grating sensors, and pointed out the becareful prodeeding when to link no more than twenty sensors to one fiber for the demodulator precision.Discussed how to construct the data acquisition system and its function via the sensors and their demodulator.One fiber of the linked sensors connected to one channel of the demodulator and all together reached sixteen channels.The demodulator were connected to the switch through rj45 interface and communicated with the acquisition server.Designed the software program of data acquisition software system and the database,which used the Sqlite of the embed database to storage the configure information and receive the data through the TCP/IP protocol.It has been build a bridge health monitoring system base on fiber bragg grating technology.

  4. 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.

  5. Color in Bridge-Substituted Cyanines.

    Science.gov (United States)

    Olsen, Seth

    2016-12-29

    Theories of color in cyanine dyes have evolved around the idea of a "resonance" of structures with distinct bonding and charge localization. Understanding the emergence of resonance models from the underlying many-electron problem remains a central issue for these systems. Here, the issue is addressed using a maximum-entropy approach to valence-bond representations of state-averaged complete-active space self-consistent field models. The approach allows calculation of energies and couplings of high-energy valence-bond structures that mediate superexchange couplings and chemical bonding. A series of valence-bond Hamiltonians for a series of bridge-substituted derivatives of Michler's hydrol blue (a monomethine cyanine) is presented. The Hamiltonians are approximated with a simple linear model parametrized by the Brown-Okamoto σp(+) parameter of the bridge substituent. A quantitative lower bound on σp(+), beyond which a resonant cyanine-like ground state will not exist, is presented. The large effective coupling in two-state resonance models emerges from superexchange associated with either covalent bonding or charge-carrier delocalization, with the former contribution significantly the stronger. The results provide ab initio justification for empirical diabatic-state models of methine optical response. They are of general interest for understanding the optoelectronic response in cyanines.

  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

    Directory of Open Access Journals (Sweden)

    L.J. Prendergast

    2014-04-01

    Full Text Available 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. Monitoring 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. 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.

  9. Probabilistic FE analysis of a cable stayed composite bridge

    NARCIS (Netherlands)

    Boer, A. de; Waarts, P.H.

    1999-01-01

    This paper describes the design of a new cable stayed composite bridge near Kampen in the Netherlands. In the design process, the safety of bridges is insured by means of partial safety factors for both strength and load parameters. As a result it is generally accepted that the structure as a whole

  10. Resolving Signals to Cohesion: Two Models of Bridging Inference.

    Science.gov (United States)

    Hegarty, Mary; Revlin, Russell

    1999-01-01

    Suggests two models of how readers create bridging inferences to resolve signals to textual cohesion. Evaluates reading times, verification accuracy, verification latency, and regressive eye fixations to support the model which views bridges as the result of a form of deduction in which the reader tacitly establishes premises that provide rational…

  11. Reliability assessment of welded steel details in bridges using inspection

    DEFF Research Database (Denmark)

    Toft, Henrik Stensgaard; Sørensen, John Dalsgaard; Yalamas, T.

    2014-01-01

    of the membrane stresses are estimated using a generic bridge structure and traffic measurements. The optimal reliability level for a welded detail in a bridge subjected to fatigue are estimated by cost benefit-analysis taking into account the risk of human lives through the Life Quality Index. Since the optimal...

  12. 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...

  13. Experimental Investigation of Aerodynamic Instability of Iced Bridge Cable Sections

    DEFF Research Database (Denmark)

    Koss, Holger; Lund, Mia Schou Møller

    2013-01-01

    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...

  14. 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.

  15. "Intercellular bridges" in a case of well differentiated squamous carcinoma.

    Science.gov (United States)

    Nguyen, Michaela; Mikita, Geoffrey; Hoda, Rana S

    2016-02-01

    Intercellular bridges may aide in definitive identification of malignant cell origin, especially in squamous cell carcinoma. They are difficult to identify in routine cytologic specimens and are especially rare in smear preparations. Herein, we present images of intercellular bridges from a case of well differentiated squamous cell carcinoma of the esophagus in a cytologic specimen obtained from FNA of a paraesophageal lymph node.

  16. 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....

  17. Fragility curves for bridges under differential support motions

    DEFF Research Database (Denmark)

    Konakli, Katerina

    2012-01-01

    This paper employs the notion of fragility to investigate the seismic vulnerability of bridges subjected to spatially varying support motions. Fragility curves are developed for four highway bridges in California with vastly different structural characteristics. The input in this analysis consists...

  18. 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.

  19. 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.

  20. 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...

  1. Life-Cycle Management Strategy on Steel Girders in Bridges

    Directory of Open Access Journals (Sweden)

    Kevin K. L. So

    2012-01-01

    Full Text Available The major problems affecting the service life of bridges are related to various factors such as fatigue-sensitive details, increased service loads, corrosion deterioration, and the lack of proper maintenance. Among them, corrosion deterioration and fatigue damages of structures particularly to steel girder bridges are the most common ones. Bridges of different structural forms, at different locations or under different climates, may suffer from various degrees of deterioration. Steel girders at different positions of a bridge may also suffer from different degrees of damage. How to effectively maintain the bridge asset at a minimal cost and how to predict the time for future works are crucial, particularly when government funding sources become stretched. A comprehensive bridge management framework assisting stakeholders to appropriately and reasonably prioritize their future maintenance-related works in their bridge stocks, such that stakeholders can better allocate the limited resources, is utmost concerned. This paper proposes an integrated life-cycle management (LCM strategy on steel girders in bridges in which corrosion deterioration and fatigue damage prediction models are mapped with girders’ performance conditions. A practical example to demonstrate the applicability of the proposed LCM strategy is also illustrated.

  2. Modeling liquid bridge between surfaces with contact angle hysteresis.

    Science.gov (United States)

    Chen, H; Amirfazli, A; Tang, T

    2013-03-12

    This paper presents the behaviors of a liquid bridge when being compressed and stretched in a quasi-static fashion between two solid surfaces that have contact angle hysteresis (CAH). A theoretical model is developed to obtain the profiles of the liquid bridge given a specific separation between the surfaces. Different from previous models, both contact lines in the upper and lower surfaces were allowed to move when the contact angles reach their advancing or receding values. When the contact angles are between their advancing and receding values, the contact lines are pinned while the contact angles adjust to accommodate the changes in separation. Effects of CAH on both asymmetric and symmetric liquid bridges were analyzed. The model was shown to be able to correctly predict the behavior of the liquid bridge during a quasi-static compression/stretching loading cycle in experiments. Because of CAH, the liquid bridge can have two different profiles at the same separation during one loading and unloading cycle, and more profiles can be obtained during multiple cycles. The maximum adhesion force generated by the liquid bridge is found to be influenced by the CAH of surfaces. CAH also leads to energy cost during a loading cycle of the liquid bridge. In addition, the minimum separation between the two solid surfaces is shown to affect how the contact radii and angles change on the two surfaces as the liquid bridge is stretched.

  3. Multidisciplinary health monitoring of a steel bridge deck structure

    NARCIS (Netherlands)

    Pahlavan, P.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

  4. Strategic Planning for the National Bridge Stock of Iran

    Directory of Open Access Journals (Sweden)

    Ali Sahrapeyma

    2013-06-01

    Full Text Available The National Bridge Stock of Iran consists of about 330,000 bridges, of which around 50% are older than 30 years. Since 2010, Iran Road Maintenance & Transportation Organization has started implementing a comprehensive Bridge Management System in order to manage this aged stock efficiently. To predict future conditions of bridge stock, a heuristic numerical method is presented. This methodology is based on Markovian process to model deterioration of bridge decks and a multi-objective optimization problem to find the best solutions. The optimization problem involves three decision variables regarding management strategies, and has three objectives regarding cost minimization. Constraints of the problem are the percentage of deficient bridges, the percentage of bridges under MR&Rs (Maintenance, Repair and Rehabilitation and the average value of condition scores. The results show that to avoid future challenges, the annual budget for bridge maintenance should be increased, the current maintenance strategy should be improved as soon as possible, and national manuals and instructions for inspection, condition rating and maintenance should be developed.

  5. A fiber-bridging model with stress gradient effects

    Science.gov (United States)

    Yi, Sun; Tao, Li

    2000-05-01

    A fiber-bridging model with stress gradient effects is proposed for unidirectional fiber-reinforced composites. The stress gradient terms are introduced by solving a micromechanical model under a non-uniform stress loading. It is shown that the stress gradient effect is significant on both the fiber-bridging stress distribution and the value of the critical load of fiber failure.

  6. 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 ...

  7. 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.

  8. 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.

  9. Comprehensive Bridge Health Evaluation Method Based on Information Fusion

    Directory of Open Access Journals (Sweden)

    Li Li-ping

    2016-01-01

    Full Text Available In the bridge maintenance management decision, the health evaluation on bridge structure is far more than determination of abnormal index exceed fixed threshold, or evaluation on damage status and carrying capacity, the on-site human inspection should also be paid attention. In order to achieve more accurate and reliable health status evaluation result, it needs to take full advantage of various information and parameter. The D-S evidence information fusion was used in the paper to present comprehensive bridge health evaluation method. It fuses bridge operation status using abnormal status identification, bridge durability with residual life estimation, as well as human inspection rating, to arrive at health evaluation. The actual application examples to verify the method is also provided.

  10. Information-theoretical noninvasive damage detection in bridge structures

    Science.gov (United States)

    Sudu Ambegedara, Amila; Sun, Jie; Janoyan, Kerop; Bollt, Erik

    2016-11-01

    Damage detection of mechanical structures such as bridges is an important research problem in civil engineering. Using spatially distributed sensor time series data collected from a recent experiment on a local bridge in Upper State New York, we study noninvasive damage detection using information-theoretical methods. Several findings are in order. First, the time series data, which represent accelerations measured at the sensors, more closely follow Laplace distribution than normal distribution, allowing us to develop parameter estimators for various information-theoretic measures such as entropy and mutual information. Second, as damage is introduced by the removal of bolts of the first diaphragm connection, the interaction between spatially nearby sensors as measured by mutual information becomes weaker, suggesting that the bridge is "loosened." Finally, using a proposed optimal mutual information interaction procedure to prune away indirect interactions, we found that the primary direction of interaction or influence aligns with the traffic direction on the bridge even after damaging the bridge.

  11. 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.

  12. 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.

  13. 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.

  14. Computation simulation of the nonlinear response of suspension bridges

    Energy Technology Data Exchange (ETDEWEB)

    McCallen, D.B.; Astaneh-Asl, A.

    1997-10-01

    Accurate computational simulation of the dynamic response of long- span bridges presents one of the greatest challenges facing the earthquake engineering community The size of these structures, in terms of physical dimensions and number of main load bearing members, makes computational simulation of transient response an arduous task. Discretization of a large bridge with general purpose finite element software often results in a computational model of such size that excessive computational effort is required for three dimensional nonlinear analyses. The aim of the current study was the development of efficient, computationally based methodologies for the nonlinear analysis of cable supported bridge systems which would allow accurate characterization of a bridge with a relatively small number of degrees of freedom. This work has lead to the development of a special purpose software program for the nonlinear analysis of cable supported bridges and the methodologies and software are described and illustrated in this paper.

  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. Towards Sustainable Construction: Life Cycle Assessment of Railway Bridges

    DEFF Research Database (Denmark)

    Du, Guangli

    . The life cycle assessment (LCA) method has been verified as a systematic tool, which enables the fully assessment and complete comparison for the environmental impact among different bridge options through a life cycle manner. The study presented in this thesis is focused on railway bridges, as the LCA...... an overview introduction that serves as a supplementary description for this research work. It outlines the background theory, current development status, the LCA implementation into the railway bridges, as well as the developed excel-based LCA tool. Part two, includes three appended papers which provides...... of a bridge to fulfill the environmental requirements. Therefore, the development of LCA for railway bridges still needs further collaborative efforts from government, industry and research institutes....

  17. 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.

  18. 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.

  19. 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...... the averaged spectral densities(ASD). From the ASD the eigenfrequencies of the structure can be identified. This information can be used in the main analysis, where alle modal parameters are extracted from the spectral densities. Due to long cabling and low response levels (small ambient loads) the response...

  20. 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...... the averaged spectral densities(ASD). From the ASD the eigenfrequencies of the structure can be identified. This information can be used in the main analysis, where alle modal parameters are extracted from the spectral densities. Due to long cabling and low response levels (small ambient loads) the response...

  1. 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.

  2. A sella turcica bridge in subjects with severe craniofacial deviations.

    Science.gov (United States)

    Becktor, J P; Einersen, S; Kjaer, I

    2000-02-01

    In earlier studies, a sella turcica bridge was stated to occur in 1.75 to 6 per cent of the population. The occurrence of a sella turcica bridge has not previously been studied in a group of patients with craniofacial deviations treated by surgery. Profile radiographs from 177 individuals who had undergone combined orthodontic and surgical treatment at the Copenhagen School of Dentistry were studied. A sella turcica bridge was registered in those subjects where the radiograph revealed a continuous band of bony tissue from the anterior cranial fossa to the posterior cranial fossa across the sella turcica. Two types of sella turcica bridge were identified. A sella turcica bridge occurred in 18.6 per cent of the subjects.

  3. 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.

  4. 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...

  5. DNA-bridged Chiroplasmonic Assemblies of Nanoparticles

    Science.gov (United States)

    Kotov, Nicholas

    2015-03-01

    Chirality at nanoscale attracts a lot of attention during the last decade. A number of chiral nanoscale systems had been discovered ranging from individual nanoparticles to helical nanowires and from lithographically defined substrates. DNA bridges make possible in-silico engineering and practical construction of complex assemblies of nanoparticles with of both plasmonic and excitonic nature. In this presentation, expected and unexpected optical effects that we observed in chiral plasmonic and excitonic systems will be demonstrated. Special effort will be placed on the transitioning of theoretical and experimental knowledge about chiral nanoscale systems to applications. The most obvious direction for practical targets was so far, the design of metamaterials for negative refractive index optics. The results describing the 3D materials with the highest experimentally observed chiral anisotropy factor will be presented. It will be followed by the discussion of the recent developments in analytical application of chiral assemblies for detection of cancer and bacterial contamination.

  6. 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...

  7. 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...

  8. Switchbacks and the Bridge to Nowhere

    CERN Document Server

    Susskind, Leonard

    2014-01-01

    This paper is in three parts: Part 1 explains the relevance of Einstein-Rosen bridges for one-sided black holes. Like their two-sided counterparts, one-sided black holes are connected to ERBs whose growth tracks the increasing complexity of the quantum state. Quantitative solutions for one-sided ERBs are presented in the appendix. Part 2 calls attention to the work of Nielsen and collaborators on the geometry of quantum complexity. This geometric formulation of complexity provides a valuable tool for studying the evolution of complexity for systems such as black holes. Part 3 applies the Nielsen approach to geometrize two related black hole quantum phenomena: the rapid mixing of information through fast-scrambling; and the time dependence of the complexity of precursors, in particular the switchback effect.

  9. Artificial organs as a bridge to transplantation.

    Science.gov (United States)

    Famulari, Antonio; De Simone, Paolo; Verzaro, Roberto; Iaria, Giuseppe; Polisetti, Federico; Rascente, Marco; Aureli, Anna

    2003-05-01

    Current organ shortage is estimated to keep outpacing demand for years to come. Among the advocated strategies, artificial and bioartificial devices may prove beneficial to a wide category of patients on transplant waiting lists. Bionic organ science allows to reproduce organ architecture and function through a complex interplay of cellular and mechanical elements. Some bioartificial organs may well be used to replace anatomical defects, while others allow to compensate for failing organ functions and to bridge patients to transplantation. Among these latter, bioartificial liver (BAL) systems bear the highest potential for clinical application, even if their use is raising several controversial issues. These latter regard the identification and stratification of patients fit for transplantation, timing and type of transplantation after recovery, appropriateness of double-blind, randomized clinical trials and safety of animal and/or human cell lines. Nonetheless, bionic organ science needs to be regarded as a useful adjunct in the armamentarium of organ replacement therapies for the third millennium.

  10. Bridging knowledge capital with tourism destination stakeholders

    DEFF Research Database (Denmark)

    Wejrum, Lone Møller; Madsen, Jan Halberg; d'Ambrosio, Luigi

    2015-01-01

    Backgorund: - The background of this paper is a student initiated study trip to the area of Campi Flegrei (Italy) in April 2014. The authors of this paper participated as lecturers and arranged meetings with a variety of tourism- and hospitality organizations operating in the destination. Through...... with their own research including data collection under the supervision of the lecturers. Methods/data: - The methodology of this study is based on a qualitative investigation of local tourism and hospitality stakeholders that operate in the destination collected by lecturers/researchers and students through...... Campi Flegrei. The ambition of this paper is to give a contribution to destination management and development theories and to explore the outcome of bridging knowledge institutions with destination stakeholders....

  11. 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...

  12. Research on Cascaded H-bridge SVG

    Directory of Open Access Journals (Sweden)

    Yannan Yu

    2014-07-01

    Full Text Available Due to the sharp increase of the non-linear loads, the power quality lagged behind the need for an adequate power system. With a fast response, low loss, low output harmonic current, SVG has become the mainstream of dynamic reactive power compensation devices. The paper introduces a multilevel cascaded H-bridge SVG, featured with DSP+FPGA dual-core control unit and fault-tolerant redundant system, which will enhance the reliability and dynamic response, reduce the switching loss and equipment cost, and increase the efficiency of the reactive power compensation. Through instructing the MATLAB simulation model of SVG and testing model machine, the design correction of medium voltage SVG power circuits and parameters is verified. The model machine is working well.

  13. Tsunamis: bridging science, engineering and society.

    Science.gov (United States)

    Kânoğlu, U; Titov, V; Bernard, E; Synolakis, C

    2015-10-28

    Tsunamis are high-impact, long-duration disasters that in most cases allow for only minutes of warning before impact. Since the 2004 Boxing Day tsunami, there have been significant advancements in warning methodology, pre-disaster preparedness and basic understanding of related phenomena. Yet, the trail of destruction of the 2011 Japan tsunami, broadcast live to a stunned world audience, underscored the difficulties of implementing advances in applied hazard mitigation. We describe state of the art methodologies, standards for warnings and summarize recent advances in basic understanding, and identify cross-disciplinary challenges. The stage is set to bridge science, engineering and society to help build up coastal resilience and reduce losses.

  14. 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.

  15. 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.

  16. 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.

  17. Field Testing and Load Rating of a Short-Span Thermoplastic Bridge System, Bridge T-8519

    Science.gov (United States)

    2010-11-01

    defined as elastoplastic , meaning it had primarily elastic behavior com- bined with time-dependent fluid properties as well. Allowable stress and...degradation or damage must be considered in future load ratings. ERDC/GSL TR-10-48 38 References AASHTO. 2003. Manual for the condition evaluation... damage or deterioration. Often, bridges are rated poorly because of inaccurate representations of the structural geometry or because the material and/or

  18. 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.

  19. 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).

  20. 75 FR 38923 - Regulated Navigation Area: Niantic Railroad Bridge Construction, Niantic, CT

    Science.gov (United States)

    2010-07-07

    ... detailing the required channel work phases that will need waterway closures. There currently planned and... exceptions: (1) The channel will remain open during the four days on either side of the full moon to... RNA only at night on Sunday and Monday, not including full moon tide weeks for night fishing...

  1. 77 FR 73916 - Regulated Navigation Area; S99 Alford Street Bridge Rehabilitation Project, Mystic River, MA

    Science.gov (United States)

    2012-12-12

    ... 617-223-4000, email Mark.E.Cutter@uscg.mil ; or Lieutenant Isaac Slavitt, Coast Guard First District Waterways Management Branch, telephone 617-223-8385, email Isaac.M.Slavitt@uscg.mil . If you have questions... radio or loudhailer. Members of the Coast Guard Auxiliary may be present to inform vessel operators...

  2. 77 FR 1020 - Regulated Navigation Area; S99 Alford Street Bridge Rehabilitation Project, Mystic River, MA

    Science.gov (United States)

    2012-01-09

    ... Sector Boston Waterways Management Division, telephone (617) 223-4000, email Mark.E.Cutter@uscg.mil ; or...) 223- 8385, email Isaac.M.Slavitt@uscg.mil . If you have questions on viewing the docket, call Renee V... VHF-FM radio or loudhailer. Members of the Coast Guard Auxiliary may be present to inform...

  3. 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...

  4. Carbon footprint of construction, operation and maintenance of waterways and traffic; Merenkulun ja liikenteen hiilijalanjaelki. Osa 1: Merenkulun hiilijalanjaelki, Osa 2: Tie-, rata- ja meriliikenteen hiilijalanjaeljet

    Energy Technology Data Exchange (ETDEWEB)

    Illman, J.; Kumpulainen, A.; Pesola, A.; Vanhanen, J.

    2012-07-01

    through them. In the second part of this project, emissions caused by traffic operating on the road and rail networks and waterways were calculated. The sources of emissions were first identified and categorised into primary and secondary emissions. Primary emissions include the greenhouse gas emissions from fuels used by vehicles. Secondary emissions result from operations that enable traffic to flow such as the energy used by gas stations and railway stations or the construction and maintenance of parking areas. It was concluded that the emissions caused by traffic are significantly larger than those of constructing, using and maintaining the transport infrastructure. The infrastructure of the road network has a carbon footprint of 511 000 tCO{sub 2}/a, while the emissions of traffic on the network are around 8,3 MtCO{sub 2}/a. The emissions of the main railway infrastructure are approximately 142 000 tCO{sub 2}/a and railway traffic has a carbon footprint of 315 000 tCO{sub 2}/a. For waterways the infrastructure emissions are 150 000 tCO{sub 2}/a and the emissions caused by traffic 2,4 MtCO{sub 2}/a. The share of secondary emissions of total emissions remains small. (orig.)

  5. Prosthetic rehabilitation using adhesive bridge and fixed-fixed bridge on the maxilla and telescopic crown overdenture on mandible

    Directory of Open Access Journals (Sweden)

    Indah Sulistiawaty

    2016-12-01

    Full Text Available Prosthetic rehabilitation is the rehabilitation process of masticatory and esthetics function for patients missing teeth and alveolar bone by means of manufacture and installation of dentures. The prosthetic rehabilitation commonly used include denture adhesive bridge, fixed-fixed bridge, as well as telescopic overdenture. Adhesive bridge is bridge denture consisting of single pontic and two retainer wings attached to the abutment using cement or resin. Fixed-fixed bridge is a bridge denture with rigid connectors on both ends of the pontics, whereas the telescopic crown Overdenture is a removable denture that uses linked precision on the original tooth in the form of primary coping on abutment and secondary coping on the denture. To expose the procedures of prosthetic rehabilitation using adhesive bridge and fixed-fixed bridge on the maxilla and telescopic crown Overdenture on mandible. Male patients aged 32 years came with complaints of difficulty to chew food because he had lost some teeth behind. In the maxilla, teeth are lost in the region of 15 and 16 performed by making the fixed-fixed bridge with abutment teeth 14 and 17. Loss of teeth in the region of 26, performed the manufacture of adhesive bridge with a box preparation on the occlusal 25 and 27. In the mandible, tooth loss in the region of 36,37,46, and 47 performed manufacture of telescopic crown Overdenture with primer coping on the teeth 35.38, 45, and 48 and the secondary coping on a metal frame. Prosthetic rehabilitation especially in the case of loss of back teeth is very important because with the denture patients can chew properly and maintain the stomatognathic system.

  6. Three-dimensional model to capture the fate and transport of combined sewer overflow discharges: A case study in the Chicago Area Waterway System.

    Science.gov (United States)

    Quijano, Juan C; Zhu, Zhenduo; Morales, Viviana; Landry, Blake J; Garcia, Marcelo H

    2017-01-15

    We used a numerical model to analyze the impact of combined sewer overflows (CSOs) in the hydrodynamics and water quality of the Chicago Area Waterway System (CAWS). We coupled the Environmental Fluid Dynamics Code (EFDC) with the Water Quality Analysis Simulation Program (WASP) to perform three-dimensional simulations of the hydrodynamics and water quality in CAWS. The analysis was performed for two different storms: (i) May 6, 2009 representing a 6-hour duration 4-month return period, and (ii) September 12, 2008 representing a 48-hour duration 100-year return period. Results from the simulations show distinct differences between the two storms. During the May 2009 storm there was only one major CSO pumping event with negligible impact on the water quality of CAWS. During the September 2008 storm there were several CSOs that impacted the hydrodynamics and water quality of CAWS. In particular, CSOs during the September 2008 event induced a reversal flow in CAWS, with a plume of constituents that traveled in the opposite direction as water does under normal conditions. However, the simulation results show that CSOs events in CAWS take place during periods of high rainfall, thus the discharge of CSOs is significantly diluted along the CAWS. As a result, the concentrations of organic matter and inorganic nutrients observed at the downstream boundary in CAWS were significantly lower than those recorded at the CSOs outfalls and are within the limits established in the regulation for regular effluents. These results suggest that even during storms events with significant CSOs into the CAWS there is a significant dilution that reduce the impact in the water quality at the system boundaries.

  7. Expected damages of retrofitted bridges with RC jacketing

    Science.gov (United States)

    Montes, O.; Jara, J. M.; Jara, M.; Olmos, B. A.

    2015-07-01

    The bridge infrastructure in many countries of the world consists of medium span length structures built several decades ago and designed for very low seismic forces. Many of them are reinforced concrete structures that according to the current code regulations have to be rehabilitated to increase their seismic capacity. One way to reduce the vulnerability of the bridges is by using retrofitting techniques that increase the strength of the structure or by incorporating devices to reduce the seismic demand. One of the most common retrofit techniques of the bridges substructures is the use of RC jacketing; this research assesses the expected damages of seismically deficient medium length highway bridges retrofitted with reinforced concrete jacketing, by conducting a parametric study. We select a suite of twenty accelerograms of subduction earthquakes recorded close to the Pacific Coast in Mexico. The original structures consist of five 30 m span simple supported bridges with five pier heights of 5 m, 10 m, 15 m 20 and 25 m and the analyses include three different jacket thickness and three steel ratios. The bridges were subjected to the seismic records and non-linear time history analyses were carried out by using the OpenSEEs Plataform. Results allow selecting the reinforced concrete jacketing that better improves the expected seismic behavior of the bridge models.

  8. 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.

  9. Environmental life cycle assessment of railway bridge materials using UHPFRC

    Science.gov (United States)

    Bizjak, Karmen Fifer; Šajna, Aljoša; Slanc, Katja; Knez, Friderik

    2016-10-01

    The railway infrastructure is a very important component of the world's total transportation network. Investment in its construction and maintenance is significant on a global scale. Previously published life cycle assessment (LCA) studies performed on road and rail systems very seldom included infrastructures in detail, mainly choosing to focus on vehicle manufacturing and fuel consumption. This article presents results from an environmental study for railway steel bridge materials for the demonstration case of the Buna Bridge in Croatia. The goal of these analyses was to compare two different types of remediation works for railway bridges with different materials and construction types. In the first part, the environmental impact of the classical concrete bridge construction was calculated, whereas in the second one, an alternative new solution, namely, the strengthening of the old steel bridge with ultra-high-performance fibre-reinforced concrete (UHPFRC) deck, was studied. The results of the LCA show that the new solution with UHPFRC deck gives much better environmental performance. Up to now, results of LCA of railway open lines, railway bridges and tunnels have been published, but detailed analyses of the new solution with UHPFRC deck above the old bridge have not previously been performed.

  10. Conversion of midbodies into germ cell intercellular bridges

    Science.gov (United States)

    Greenbaum, Michael P.; Ma, Lang; Matzuk, Martin M.

    2009-01-01

    Whereas somatic cell cytokinesis resolves with abscission of the midbody, resulting in independent daughter cells, germ cell cytokinesis concludes with the formation of a stable intercellular bridge interconnecting daughter cells in a syncytium. While many proteins essential for abscission have been discovered, until recently, no proteins essential for mammalian germ cell intercellular bridge formation have been identified. Using TEX14 as a marker for the germ cell intercellular bridge, we show that TEX14 co-localizes with the centralspindlin complex, mitotic kinesin-like protein 1 (MKLP1) and male germ cell Rac GTPase-activating protein (MgcRacGAP), and converts these midbody matrix proteins into stable intercellular bridge components. In contrast, septins (SEPT) 2, 7, and 9 are transitional proteins in the newly forming bridge. In cultured somatic cells, TEX14 can localize to the midbody in the absence of other germ cell specific factors, suggesting that TEX14 serves to bridge the somatic cytokinesis machinery to other germ cell proteins to form a stable intercellular bridge essential for male reproduction. PMID:17383626

  11. 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.

  12. 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.

  13. 始于设计的水运工程安全风险管理%Health and safety management initiated early from design stage for waterway transportation construction projects

    Institute of Scientific and Technical Information of China (English)

    徐少鲲; 靖斐

    2015-01-01

    介绍了发达国家解决安全管理方面问题并推进安全设计的经验,通过理论分析探讨了在设计阶段即开始安全风险管理的重要性,结合国内外安全设计的研究成果总结了设计人在安全设计中的责任和安全设计的一般流程,并结合水运工程的特点提出了水运工程项目安全设计所需要考虑的典型风险源,同时还结合实际项目给出了多个水运项目中安全设计的实例。%We introduced the experience about the developed countries solved the health and safety management problems and promoted the safety design, discussed the importance of safety risk management at the beginning of design. Combining with the research results of the safety design at home and abroad, we summarized designer's responsibility and general process of a safety design, and based on the specific characteristics of waterway transportation construction projects, we put forward the typical risk sources in the safety design of waterway transportation project, and presented several safety design cases for waterway transportation project by combining with the practical projects.

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

    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。

  15. 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.

  16. 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.

  17. 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.

  18. 基于船舶自组织态势分析的内河航道聚簇预测%Prediction of Inland Waterway Cluster Based on Analysis of Ship Self Organization Situation

    Institute of Scientific and Technical Information of China (English)

    何金灿

    2014-01-01

    Inland waterway traffic flow prediction is an important theory base of freedom of navigation, traditional method takes the single neural network prediction algorithm, when the ship occurs fast clustering, the position and velocity parame-ters is nonlinear, the prediction accuracy is not good. An improved inland waterway traffic flow cluster prediction method is proposed based on self-organizing network situation analysis, the inland waterway traffic situation information perception model is constructed, and the information perception and communication positioning are used to achieve clustering and in-formation interaction, the nonlinear Karman equation is used to construct the situation analysis equation, and the conges-tion degree memory parameter is defined, the measurement information in the history of inland waterway is abandoned, con-gestion degree is judged, the prediction is realized. The experiment is taken based on Netlogo, Simulation result shows that the new method has better prediction accuracy.%内河航道交通流预测是保证航道通畅的重要理论根据,传统的航道交通流预测采用线性单态神经网络预测算法,当航运船舶快速聚簇,位置和速度信息参量呈非线性变化时,预测精度不好。提出一种基于船舶自组织网络态势分析的内河航道交通流聚簇预测方法,构建内河航道交通态势分析信息感知模型,通过信息感知和通信定位实现聚簇信息交互,采用非线性卡尔曼方程构建船舶态势分析状态方程,得到航行拥堵程度记忆因子,逐步舍弃内河航道内的交通流历史测量信息,判断航道的拥堵程度,实现对船舶自组织态势分析和流量预测。采用Netlogo设置仿真场景进行仿真实验,实验结果得出采用该算法船舶信息检测和流量预测精度提高显著,预测精度高。

  19. Yangzhou’s Famous Twenty-fourth Bridge

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    “LOOMING green moun-tains and runningstreams;grass does notwither and fall,though the autumnhas come to an end in the south.The bright moon arises overTwenty-fourth Bridge.Where doyou teach pure-jade Yangzhouwomen to play music on bambooflutes?”This poem by Du Mu(803-c.852),a famous poet of thelate Tang Dynasty,is well remem-bered today It made Yangzhou’sTwenty-fourth Bridge Known to la-ter generations.Of many ancientpoems about Twenty-fourth Bridge

  20. Einstein-Rosen "Bridge" Needs Lightlike Brane Source

    OpenAIRE

    Guendelman, Eduardo; Kaganovich, Alexander; Nissimov, Emil; Pacheva, Svetlana

    2009-01-01

    The Einstein-Rosen "bridge" wormhole solution proposed in the classic paper [1] does not satisfy the vacuum Einstein equations at the wormhole throat. We show that the fully consistent formulation of the original Einstein-Rosen "bridge" requires solving Einstein equations of bulk D=4 gravity coupled to a lightlike brane with a well-defined world-volume action. The non-vanishing contribution of Einstein-Rosen "bridge" solution to the right hand side of Einstein equations at the throat matches ...