WorldWideScience

Sample records for bridge engineering

  1. 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.

  2. 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

  3. Translating Climate Projections for Bridge Engineering

    Science.gov (United States)

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

    2015-12-01

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

  4. Helping System Engineers Bridge the Peaks

    Science.gov (United States)

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

    2014-01-01

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

  5. 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. PMID:26392618

  6. 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.

  7. Information Geography: A Bridge between Engineering and the Social Sciences

    Science.gov (United States)

    Paradiso, Maria

    2006-01-01

    This paper presents the metaphor of engineering and the social sciences located on either side of a chasm and connected by the bridge of information geography. Information geography is not an integral part of engineering and is a new field within geography, a social science discipline. The specialty of information geography is one of the newest in…

  8. Bridging the Gap Between Engineering Workforce Needs and Student Engagement

    OpenAIRE

    Goold, Eileen

    2015-01-01

    This paper is inspired by the development of the proposed new technological university in Dublin; TU4Dublin is to become “Dublin’s Globally Engaged University” and is to be located at the nexus between learning and engagement (TU4Dublin, 2015). This study investigates engineering education in the context of career focused education. The main objective of this study is to investigate whether engineering students’ cognitive engagement benefits from bridging the gap between technical issues and ...

  9. Exploring Bridge-Engine Control Room Collaborative Team Communication

    Directory of Open Access Journals (Sweden)

    Aditi Kataria

    2015-06-01

    Full Text Available The EC funded CyClaDes research project is designed to promote the increased impact of the human element in shipping across the design and operational lifecycle. It addresses the design and operation of ships and ship systems. One of the CyClaDes’ tasks is to create a crew-centered design case-study examination of the information that is shared between the Bridge and Engine Control Room that helps the crew co-ordinate to ensure understanding and complete interconnected tasks. This information can be provided in various ways, including communication devices or obtained from a common database, display, or even the ship environment (e.g., the roll of the ship. A series of semi-structured interviews were conducted with seafarers of diverse ranks to get a better idea of what communication does, or should, take place and any problems or challenges existing in current operations, as seen from both the bridge and ECR operators’ perspectives. Included in the interview were both the standard communications and information shared during planning and executing a voyage, as well as special situations such as safety/casualty tasks or heavy weather. The results were analyzed in terms of the goals of the communication, the primary situations of interest for communication and collaboration, the communication media used, the information that is shared, and the problems experienced. The results of seafarer interviews are presented in the paper to explore on-board inter-departmental communication.

  10. Application of Composite Structures in Bridge Engineering. Problems of Construction Process and Strength Analysis

    OpenAIRE

    Flaga Kazimierz; Furtak Kazimierz

    2015-01-01

    Steel-concrete composite structures have been used in bridge engineering from decades. This is due to rational utilisation of the strength properties of the two materials. At the same time, the reinforced concrete (or prestressed) deck slab is more favourable than the orthotropic steel plate used in steel bridges (higher mass, better vibration damping, longer life).

  11. Application of Composite Structures in Bridge Engineering. Problems of Construction Process and Strength Analysis

    Directory of Open Access Journals (Sweden)

    Flaga Kazimierz

    2015-03-01

    Full Text Available Steel-concrete composite structures have been used in bridge engineering from decades. This is due to rational utilisation of the strength properties of the two materials. At the same time, the reinforced concrete (or prestressed deck slab is more favourable than the orthotropic steel plate used in steel bridges (higher mass, better vibration damping, longer life.

  12. Suspension Bridges: A Merger of Physics, Engineering, and Art

    Science.gov (United States)

    Greenslade, Thomas B., Jr.

    1974-01-01

    Discusses the physical principles underlying the design of a small scale suspension bridge, including its types and strength calculations. Included are the working equation and two formulas for determining the load per unit length. (CC)

  13. Assessment of Factors Impacting Success for Incoming College Engineering Students in a Summer Bridge Program

    Science.gov (United States)

    Reisel, John R.; Jablonski, Marissa; Hosseini, Hossein; Munson, Ethan

    2012-01-01

    A summer bridge program for incoming engineering and computer science freshmen has been used at the University of Wisconsin-Milwaukee from 2007 to 2010. The primary purpose of this program has been to improve the mathematics course placement for incoming students who initially place into a course below Calculus I on the math placement examination.…

  14. Bridging Courses in Chemistry and Physics for Engineering Students.

    Science.gov (United States)

    Mitchell, Ian J.; de Jong, Eddy J.

    1994-01-01

    A Monash University (Australia) program to enhance the chemistry and physics preparation of secondary school graduates entering engineering in higher education offers one-semester intensive courses. The first four years of the program have produced encouraging results. Coordination of practical work and theory is seen as crucial to learning. (MSE)

  15. Application of Composite Structures in Bridge Engineering. Problems of Construction Process and Strength Analysis

    Science.gov (United States)

    Flaga, Kazimierz; Furtak, Kazimierz

    2015-03-01

    Steel-concrete composite structures have been used in bridge engineering from decades. This is due to rational utilisation of the strength properties of the two materials. At the same time, the reinforced concrete (or prestressed) deck slab is more favourable than the orthotropic steel plate used in steel bridges (higher mass, better vibration damping, longer life). The most commonly found in practice are composite girder bridges, particularly in highway bridges of small and medium spans, but the spans may reach over 200 m. In larger spans steel truss girders are applied. Bridge composite structures are also employed in cable-stayed bridge decks of the main girder spans of the order of 600, 800 m. The aim of the article is to present the cionstruction process and strength analysis problems concerning of this type of structures. Much attention is paid to the design and calculation of the shear connectors characteristic for the discussed objects. The authors focused mainly on the issues of single composite structures. The effect of assembly states on the stresses and strains in composite members are highlighted. A separate part of problems is devoted to the influence of rheological factors, i.e. concrete shrinkage and creep, as well as thermal factors on the stresses and strains and redistribution of internal forces.

  16. Bridging the Divide between Neuroprosthetic Design, Tissue Engineering and Neurobiology

    OpenAIRE

    Jennie Leach; Achyuta, Anil Kumar H.; Murthy, Shashi K

    2010-01-01

    Neuroprosthetic devices have made a major impact in the treatment of a variety of disorders such as paralysis and stroke. However, a major impediment in the advancement of this technology is the challenge of maintaining device performance during chronic implantation (months to years) due to complex intrinsic host responses such as gliosis or glial scarring. The objective of this review is to bring together research communities in neurobiology, tissue engineering, and neuroprosthetics to addre...

  17. Bridging the divide between neuroprosthetic design, tissue engineering and neurobiology

    Directory of Open Access Journals (Sweden)

    Jennie Leach

    2010-02-01

    Full Text Available Neuroprosthetic devices have made a major impact in the treatment of a variety of disorders such as paralysis and stroke. However, a major impediment in the advancement of this technology is the challenge of maintaining device performance during chronic implantation (months to years due to complex intrinsic host responses such as gliosis or glial scarring. The objective of this review is to bring together research communities in neurobiology, tissue engineering, and neuroprosthetics to address the major obstacles encountered in the translation of neuroprosthetics technology into long-term clinical use. This article draws connections between specific challenges faced by current neuroprosthetics technology and recent advances in the areas of nerve tissue engineering and neurobiology. Within the context of the device-nervous system interface and central nervous system (CNS implants, areas of synergistic opportunity are discussed, including platforms to present cells with multiple cues, controlled delivery of bioactive factors, three-dimensional constructs and in vitro models of gliosis and brain injury, nerve regeneration strategies, and neural stem/progenitor cell (NPC biology. Finally, recent insights gained from the fields of developmental neurobiology and cancer biology are discussed as examples of exciting new biological knowledge that may provide fresh inspiration towards novel technologies to address the complexities associated with long-term neuroprosthetic device performance.

  18. Mathematics Education for Engineering Technology Students – A Bridge Too Far?

    Directory of Open Access Journals (Sweden)

    Noraishiyah Abdullah

    2013-03-01

    Full Text Available Trying to decide what is best suited for someone or something is an ever enduring task let alone trying to prepare students with the right engineering mind. So ‘how do you build an engineer?’ if that is the right word. What is the right ingredient? Mathematics has been said as the most important foundation in engineers’ life. Curriculum has been developed and reviewed over the years to meet this target. This work explores how much or lack of it has the curriculum prepares the future technologist to face the world of engineering technology as far as mathematics is concerned. Analysis of mathematics lectures, interviews of engineering technologist students and engineering technology subject lecturer is undertaken. Understand what each contributes help in understanding the picture that the current education is painting. Based on the theory of learning, APOS theory helps in explaining how students bridge their knowledge of mathematics when it comes to solving engineering technology problems. The question is, is it a bridge too far? 

  19. Practice and experience of engineering culture development in the Sutong Bridge project

    Institute of Scientific and Technical Information of China (English)

    Yu Chunsheng; Yao Bei; Wang Qian

    2009-01-01

    To keep up with the time, culture is integrated to large-scale construction project management in China, which will absolutely add more vitality into construction project management in our country. Engineering culture is an integration of project construction and engineering culture. However, engineering culture development enjoys its own particularity as a project is constructed once only within a limited period of time. This paper gives affirmative opinion that engineering culture development in large-scale projects backs project management on the basis of thorough investigation of engineering culture development in Sutong Bridge Project and after deepened analysis, proposes new thinking pattern of engineering culture development in large-scale projects in a systematic manner, including thorough understanding of the essence of engineering culture, principle and contents of engineering culture development as well as efficient method in respect of establishment and implementation of engineering culture, and therefore provides a standard reference and systematic thinking pattern for engineering culture development in future large-scale projects.

  20. Agile Market Engineering: Bridging the gap between business concepts and running markets

    OpenAIRE

    Block, Carsten Alexander

    2010-01-01

    The agile market engineering process model (AMEP) is built on the insight, that market design and development is a wicked problem. Electronic markets are too complex to be completely designed upfront. Instead, AMEP tries to bridge the gap between theoretic market design and practical electronic market platform development using an agile, iterative approach that relies on early customer feedback and continuous improvement. The AMEP model is complemented by several supporting software artifacts.

  1. An Automatic Method for Geometric Segmentation of Masonry Arch Bridges for Structural Engineering Purposes

    Science.gov (United States)

    Riveiro, B.; DeJong, M.; Conde, B.

    2016-06-01

    Despite the tremendous advantages of the laser scanning technology for the geometric characterization of built constructions, there are important limitations preventing more widespread implementation in the structural engineering domain. Even though the technology provides extensive and accurate information to perform structural assessment and health monitoring, many people are resistant to the technology due to the processing times involved. Thus, new methods that can automatically process LiDAR data and subsequently provide an automatic and organized interpretation are required. This paper presents a new method for fully automated point cloud segmentation of masonry arch bridges. The method efficiently creates segmented, spatially related and organized point clouds, which each contain the relevant geometric data for a particular component (pier, arch, spandrel wall, etc.) of the structure. The segmentation procedure comprises a heuristic approach for the separation of different vertical walls, and later image processing tools adapted to voxel structures allows the efficient segmentation of the main structural elements of the bridge. The proposed methodology provides the essential processed data required for structural assessment of masonry arch bridges based on geometric anomalies. The method is validated using a representative sample of masonry arch bridges in Spain.

  2. HVAC in sustainable office buildings a bridge between owners and engineers

    CERN Document Server

    Hovorka, Frank; Kurnitski, Jarek; Litiu, Andrei

    2012-01-01

    This guidebook aims to build a bridge between the real estate community and the engineering community. It explains the challenges of property valuation based on real data and how the sustainability and HVAC-technology can have an impact on value. It also gathers the latest HVAC- and other technologies used in sustainable buildings and gives some real case study examples. But maybe the most important part in terms of improved communication between the owners and engineers is the list of questions to be asked during the life time of a building. It is impossible to give all the right answers in this guidebook, but we will raise some pertinent questions. As climates and cultures are different, as well as existing building types and energy production, the same solutions do not solve problems universally. This guidebook is aimed for the owners and architects as well as engineers. It doesn’t require deep technical knowhow of HVAC-systems or real estate valuation.

  3. Civil and environmental engineering faculty members to serve as principal investigators on bridge project

    OpenAIRE

    Daniilidi, Christina

    2009-01-01

    Is there a doctor in the house to check on this bridge? A bridge is like a living organism. It requires frequent health check-ups and maintenance, and its lifespan is 50 years on the average. With limited resources and an aging bridge population, bridge owners need reliable information on bridge health in order to manage their bridge inventory efficiently and economically. Although the tragic bridge collapse in Minneapolis in the summer of 2007 was not attributed to poor maintenance, everyone...

  4. Construction engineering of steel tub-girder bridge systems for skew effects

    Science.gov (United States)

    Jimenez Chong, Juan Manuel

    understanding of the level of sophistication of analysis models required to properly predict forces and deformations of curved and/or skewed bridges during construction is limited. The development of guidelines regarding the sufficiency of simplified methods of structural analysis is the overall motivation and objective of this dissertation. This research addresses the construction load effects due to skew and due to combined skew and curvature and develops design recommendations and analytical tools for the construction engineering of tub-girder bridges. The effects of skew and curvature are studied by examining the results for different levels of analysis for 18 representative bridges. These bridges reflect the range of bridge curvature and skew used in current practice. By comparing the output from simplified analysis methods to validated refined 3D FEA solutions, general conclusions are developed as to when the simplified methods provide sufficient results. An important original contribution of this research is that the data generated constitutes the first systematic study on a large set of curved and skewed tub-girder bridges using consistent refined 3D FEA models to model construction forces and deformations. As such, the results of this research can serve as a benchmark for current and future improvements in methods of analysis and design for the construction engineering of curved and skewed tub-girder bridges. In the current research, this data has been used in both straight and curved tub-girder bridges to: • Develop a simplified 1D analysis method to account for the effect of skew on girder twist rotations and internal torques, • Evaluate the effect of skew on component forces, and propose improved simplified procedures to capture these effects, • Identify interactions between components and develop improved simplified analysis methods to account for these effects, • Establish limits for when the improved 1D and 2D simplified methods of analysis are sufficient

  5. Replication of engine block cylinder bridge microstructure and mechanical properties with lab scale 319 Al alloy billet castings

    Energy Technology Data Exchange (ETDEWEB)

    Lombardi, A., E-mail: a2lombar@ryerson.ca [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard Street East, Toronto, Ontario M5B2K3 (Canada); D' Elia, F.; Ravindran, C. [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard Street East, Toronto, Ontario M5B2K3 (Canada); MacKay, R. [Nemak of Canada Corporation, 4600 G.N. Booth Drive, Windsor, Ontario N9C4G8 (Canada)

    2014-01-15

    In recent years, aluminum alloy gasoline engine blocks have in large part successfully replaced nodular cast iron engine blocks, resulting in improved vehicle fuel efficiency. However, because of the inadequate wear resistance properties of hypoeutectic Al–Si alloys, gray iron cylinder liners are required. These liners cause the development of large tensile residual stress along the cylinder bores and necessitate the maximization of mechanical properties in this region to prevent premature engine failure. The aim of this study was to replicate the engine cylinder bridge microstructure and mechanical properties following TSR treatment (which removes the sand binder to enable easy casting retrieval) using lab scale billet castings of the same alloy composition with varying cooling rates. Comparisons in microstructure between the engine block and the billet castings were carried out using optical and scanning electron microscopy, while mechanical properties were assessed using tensile testing. The results suggest that the microstructure at the top and middle of the engine block cylinder bridge was successfully replicated by the billet castings. However, the microstructure at the bottom of the cylinder was not completely replicated due to variations in secondary phase morphology and distribution. The successful replication of engine block microstructure will enable the future optimization of heat treatment parameters. - Highlights: • A method to replicate engine block microstructure was developed. • Billet castings will allow cost effective optimization of heat treatment process. • The replication of microstructure in the cylinder region was mostly successful. • Porosity was more clustered in the billet castings compared to the engine block. • Mechanical properties were lower in billet castings due to porosity and inclusions.

  6. Replication of engine block cylinder bridge microstructure and mechanical properties with lab scale 319 Al alloy billet castings

    International Nuclear Information System (INIS)

    In recent years, aluminum alloy gasoline engine blocks have in large part successfully replaced nodular cast iron engine blocks, resulting in improved vehicle fuel efficiency. However, because of the inadequate wear resistance properties of hypoeutectic Al–Si alloys, gray iron cylinder liners are required. These liners cause the development of large tensile residual stress along the cylinder bores and necessitate the maximization of mechanical properties in this region to prevent premature engine failure. The aim of this study was to replicate the engine cylinder bridge microstructure and mechanical properties following TSR treatment (which removes the sand binder to enable easy casting retrieval) using lab scale billet castings of the same alloy composition with varying cooling rates. Comparisons in microstructure between the engine block and the billet castings were carried out using optical and scanning electron microscopy, while mechanical properties were assessed using tensile testing. The results suggest that the microstructure at the top and middle of the engine block cylinder bridge was successfully replicated by the billet castings. However, the microstructure at the bottom of the cylinder was not completely replicated due to variations in secondary phase morphology and distribution. The successful replication of engine block microstructure will enable the future optimization of heat treatment parameters. - Highlights: • A method to replicate engine block microstructure was developed. • Billet castings will allow cost effective optimization of heat treatment process. • The replication of microstructure in the cylinder region was mostly successful. • Porosity was more clustered in the billet castings compared to the engine block. • Mechanical properties were lower in billet castings due to porosity and inclusions

  7. Engineering approach to in-situ bridge health monitoring with fiber bragg gratings

    Institute of Scientific and Technical Information of China (English)

    WU Zhan-jun; ZHANG Bo-ming; WAN Li-bing; ZHOU Zhi; OU Jin-ping

    2006-01-01

    In this presentation the feasibility and capability of fiber Bragg gratings (FBG) employed in bridge health monitoring are demonstrated on a real bridge. FBG's wavelength shift depending on strain variance has been tested. The technique of FBG installation on bridges has been developed. 12 FBG strain sensors and 3temperature sensors have been successfully embedded in the prestressed concrete box girder during the construction of Heilongjiang Hulan River Bridge. The prestressing tension process and quasi-static loading process of the girder were monitored with those sensors before it was installed onto the bridge. After the bridge was completed,the FBG sensors embedded have been utilized to monitor the strain shift of the beam under quasi-static load,traffic load and temperature. The results show that the traffic fluxes, possible fatigue damage and deflection of the bridge can be revealed conveniently through strain measurements with these FBG sensors, which provide key information for structural health diagnosis. The fact that the FBG strain sensors have withstood the ordeal of harsh construction process and lasted for more than one year proves that their durability and stability can satisfy the requirements for bridge health monitoring. It is also shown that the FBG strain sensor is more adaptive to long-term structural health monitoring than the electric resistance strain gauge.

  8. A Combined Geophysical/Engineering Approach for the Seismic Safety of Long-Span Bridges

    Science.gov (United States)

    Fäcke, Andreas; Stempniewski, Lothar; Richwalski, Sandra M.; Parolai, Stefano; Milkereit, Claus; Wang, Rongjiang; Bormann, Peter; Roth, Frank

    The spatial distribution of the resonance frequency of the sedimentary cover in the Cologne area was estimated by the horizontal-to-vertical spectral ratio method using ambient noise measurements. A comparison with the eigenfrequencies of selected long-span bridges crossing the Rhine river indicated an overlap in frequency and therefore potential damage in the case of an earthquake. Consequently, we conducted a dynamic vulnerability analysis using the finite-element method. In addition to accelerograms from design spectra, ground motion scenarios with sources located on the most proximate fault (Erft fault) were simulated using a numerical hybrid method that takes into account source, path, and site effects. The results indicated that due to the low frequency content of these scenarios, consistently higher responses - compared to the recommended loads in the German seismic code - were obtained at all selected bridges. Usage of both scenarios revealed specific failure mechanisms. While cable supported bridges seem to be secure, grave failure was detected for a box girder bridge.

  9. Educating Maritime Engineers for a Globalised Industry - Bridging the Gap Between Industry and Universities

    DEFF Research Database (Denmark)

    Andersen, Ingrid Marie Vincent; Nielsen, Ulrik Dam

    In Denmark, the maritime engineering competences requested by the industry have changed in the past one to two decades. The typical naval architects do no longer find themselves working in the ship-building industry but rather in the industry of ship operators, consultancies, class societies, etc....... This means that universities educating maritime engineers need to reflect the changes in the curricula for their maritime engineering students. Topics and issues regarding this matter have recently been addressed in a survey made in the Danish maritime industry. The survey concludes that the demand for...... maritime engineers in the industry is considerably larger than the output from the technical universities. Moreover, it sets forth a series of recommendations to the industry as well as to the universities to facilitate meeting the demand for maritime engineers in Denmark in the future. The recommendations...

  10. Discuss How to Strengthen the Quality Management of Bridge Engineering%探讨如何加强桥梁工程质量管理

    Institute of Scientific and Technical Information of China (English)

    张应赞

    2014-01-01

    At present, the bridge project is stil a very serious problem. At the same time, the quality system of bridge, the control and management of supervision department, the know-ledge popularization of bridge experts and patent protection are facing unprecedented chalenges. Therefore, this article carries on the discussion of how to strengthen the quality man-agement of bridge engineering.%目前,我国桥梁工程仍旧存在十分严峻的问题。同时,桥梁的质量体系、监理部门的职能控管、桥梁专家的知识普及和专利保护都面临绝无仅有的挑战。因此,本文对如何加强桥梁工程质量管理进行了探讨。

  11. Computational Protein Engineering: Bridging the Gap between Rational Design and Laboratory Evolution

    Directory of Open Access Journals (Sweden)

    Shina Caroline Lynn Kamerlin

    2012-09-01

    Full Text Available Enzymes are tremendously proficient catalysts, which can be used as extracellular catalysts for a whole host of processes, from chemical synthesis to the generation of novel biofuels. For them to be more amenable to the needs of biotechnology, however, it is often necessary to be able to manipulate their physico-chemical properties in an efficient and streamlined manner, and, ideally, to be able to train them to catalyze completely new reactions. Recent years have seen an explosion of interest in different approaches to achieve this, both in the laboratory, and in silico. There remains, however, a gap between current approaches to computational enzyme design, which have primarily focused on the early stages of the design process, and laboratory evolution, which is an extremely powerful tool for enzyme redesign, but will always be limited by the vastness of sequence space combined with the low frequency for desirable mutations. This review discusses different approaches towards computational enzyme design and demonstrates how combining newly developed screening approaches that can rapidly predict potential mutation “hotspots” with approaches that can quantitatively and reliably dissect the catalytic step can bridge the gap that currently exists between computational enzyme design and laboratory evolution studies.

  12. An experimental investigation of innovative bridge columns with engineered cementitious composites and Cu-Al-Mn super-elastic alloys

    Science.gov (United States)

    Hosseini, F.; Gencturk, B.; Lahpour, S.; Ibague Gil, D.

    2015-08-01

    Recent strong earthquakes have shown that reinforced concrete (RC) bridge columns constructed using conventional materials and techniques suffer from major damage and permanent deformations. The yielding of the longitudinal reinforcement as the main source of energy absorption, and cracking and spalling of concrete results in a dysfunctional bridge structure that does not support the post-disaster recovery efforts. This paper investigates the use of engineered cementitious composites (ECCs) and Cu-Al-Mn super-elastic alloys (SEAs) to improve the performance of bridge columns under seismic loads. A new column design is proposed, which is composed of a pre-fabricated ECC tube that encompasses the longitudinal and transverse steel reinforcement (rebar). The rebar in the plastic hinge region of the cantilever columns was totally or partially replaced with Cu-Al-Mn SEA bars. The tube was filled with conventional concrete after it was placed inside the rebar cage of the foundation. ECC exhibits superior tensile ductility, bonding with steel, energy absorption and shear resistance, in addition to lower permeability and reduced crack widths compared to conventional concrete. Cu-Al-Mn SEA bars are capable of recovering large inelastic deformations exceeding 12% strain. The proposed approach capitalizes on the deformability of ECC with reduced damage, and the energy absorption capacity of Cu-Al-Mn SEA bars without permanent deformation. A total of six column specimens were constructed and tested under simulated seismic loading. The number of rebars replaced with Cu-Al-Mn SEA bars, ECC mixture design, and the ratio of the concrete core area to total column cross-sectional area were the variables investigated in the test program. A comparison of the results indicated that the proposed concept with no Cu-Al-Mn SEA bars provides higher lateral strength, similar energy absorption and reduced damage compared to conventional RC columns; however, similar to a conventional column, it

  13. Seismic ground motion modelling and damage earthquake scenarios: A bridge between seismologists and seismic engineers

    International Nuclear Information System (INIS)

    The input for the seismic risk analysis can be expressed with a description of 'roundshaking scenarios', or with probabilistic maps of perhaps relevant parameters. The probabilistic approach, unavoidably based upon rough assumptions and models (e.g. recurrence and attenuation laws), can be misleading, as it cannot take into account, with satisfactory accuracy, some of the most important aspects like rupture process, directivity and site effects. This is evidenced by the comparison of recent recordings with the values predicted by the probabilistic methods. We prefer a scenario-based, deterministic approach in view of the limited seismological data, of the local irregularity of the occurrence of strong earthquakes, and of the multiscale seismicity model, that is capable to reconcile two apparently conflicting ideas: the Characteristic Earthquake concept and the Self Organized Criticality paradigm. Where the numerical modeling is successfully compared with records, the synthetic seismograms permit the microzoning, based upon a set of possible scenario earthquakes. Where no recordings are available the synthetic signals can be used to estimate the ground motion without having to wait for a strong earthquake to occur (pre-disaster microzonation). In both cases the use of modeling is necessary since the so-called local site effects can be strongly dependent upon the properties of the seismic source and can be properly defined only by means of envelopes. The joint use of reliable synthetic signals and observations permits the computation of advanced hazard indicators (e.g. damaging potential) that take into account local soil properties. The envelope of synthetic elastic energy spectra reproduces the distribution of the energy demand in the most relevant frequency range for seismic engineering. The synthetic accelerograms can be fruitfully used for design and strengthening of structures, also when innovative techniques, like seismic isolation, are employed. For these

  14. Seismic ground motion modelling and damage earthquake scenarios: a bridge between seismologists and seismic engineers

    International Nuclear Information System (INIS)

    The input for the seismic risk analysis can be expressed with a description of 'ground-shaking scenarios', or with probabilistic maps of perhaps relevant parameters. The probabilistic approach, unavoidably based upon rough assumptions and models (e.g. recurrence and attenuation laws), can be misleading, as it cannot take into account, with satisfactory accuracy, some of the most important aspects like rupture process, directivity and site effects. This is evidenced by the comparison of recent recordings with the values predicted by the probabilistic methods. We prefer a scenario-based, deterministic approach in view of the limited seismological data, of the local irregularity of the occurrence of strong earthquakes, and of the multi-scale seismicity model, that is capable to reconcile two apparently conflicting ideas: the Characteristic Earthquake concept and the Self Organized Criticality paradigm. Where the numerical modeling is successfully compared with records, the synthetic seismograms permit the micro-zoning, based upon a set of possible scenario earthquakes. Where no recordings are available the synthetic signals can be used to estimate the ground motion without having to wait for a strong earthquake to occur (pre-disaster micro-zonation). In both cases the use of modeling is necessary since the so-called local site effects can be strongly dependent upon the properties of the seismic source and can be properly defined only by means of envelopes. The point use of reliable synthetic signals and observations permits the computation of advanced hazard indicators (e.g. damaging potential) that take into account local soil properties. The envelope of synthetic elastic energy spectra reproduces the distribution of the energy demand in the most relevant frequency range for seismic engineering. The synthetic accelerograms can be fruitfully used for design and strengthening of structures, also when innovative techniques, like seismic isolation, are employed. For

  15. Hybrid coordination-network-engineering for bridging cascaded channels to activate long persistent phosphorescence in the second biological window

    Science.gov (United States)

    Qin, Xixi; Li, Yang; Zhang, Ruili; Ren, Jinjun; Gecevicius, Mindaugas; Wu, Yiling; Sharafudeen, Kaniyarakkal; Dong, Guoping; Zhou, Shifeng; Ma, Zhijun; Qiu, Jianrong

    2016-02-01

    We present a novel “Top-down” strategy to design the long phosphorescent phosphors in the second biological transparency window via energy transfer. Inherence in this approach to material design involves an ingenious engineering for hybridizing the coordination networks of hosts, tailoring the topochemical configuration of dopants, and bridging a cascaded tunnel for transferring the persistent energy from traps, to sensitizers and then to acceptors. Another significance of this endeavour is to highlight a rational scheme for functionally important hosts and dopants, Cr/Nd co-doped Zn1-xCaxGa2O4 solid solutions. Such solid-solution is employed as an optimized host to take advantage of its characteristic trap site level to establish an electron reservoir and network parameters for the precipitation of activators Nd3+ and Cr3+. The results reveal that the strategy employed here has the great potential, as well as opens new opportunities for future new-wavelength, NIR phosphorescent phosphors fabrication with many potential multifunctional bio-imaging applications.

  16. Integrating Solar Power onto the Electric Grid - Bridging the Gap between Atmospheric Science, Engineering and Economics

    Science.gov (United States)

    Ghonima, M. S.; Yang, H.; Zhong, X.; Ozge, B.; Sahu, D. K.; Kim, C. K.; Babacan, O.; Hanna, R.; Kurtz, B.; Mejia, F. A.; Nguyen, A.; Urquhart, B.; Chow, C. W.; Mathiesen, P.; Bosch, J.; Wang, G.

    2015-12-01

    One of the main obstacles to high penetrations of solar power is the variable nature of solar power generation. To mitigate variability, grid operators have to schedule additional reliability resources, at considerable expense, to ensure that load requirements are met by generation. Thus despite the cost of solar PV decreasing, the cost of integrating solar power will increase as penetration of solar resources onto the electric grid increases. There are three principal tools currently available to mitigate variability impacts: (i) flexible generation, (ii) storage, either virtual (demand response) or physical devices and (iii) solar forecasting. Storage devices are a powerful tool capable of ensuring smooth power output from renewable resources. However, the high cost of storage is prohibitive and markets are still being designed to leverage their full potential and mitigate their limitation (e.g. empty storage). Solar forecasting provides valuable information on the daily net load profile and upcoming ramps (increasing or decreasing solar power output) thereby providing the grid advance warning to schedule ancillary generation more accurately, or curtail solar power output. In order to develop solar forecasting as a tool that can be utilized by the grid operators we identified two focus areas: (i) develop solar forecast technology and improve solar forecast accuracy and (ii) develop forecasts that can be incorporated within existing grid planning and operation infrastructure. The first issue required atmospheric science and engineering research, while the second required detailed knowledge of energy markets, and power engineering. Motivated by this background we will emphasize area (i) in this talk and provide an overview of recent advancements in solar forecasting especially in two areas: (a) Numerical modeling tools for coastal stratocumulus to improve scheduling in the day-ahead California energy market. (b) Development of a sky imager to provide short term

  17. Establishing Physical and Engineering Science Base to Bridge from ITER to Demo

    Science.gov (United States)

    Peng, Y.-K. Martin; Abdou, M.; Gates, D.; Hegna, C.; Hill, D.; Najmabadi, F.; Navratil, G.; Parker, R.

    2007-11-01

    A Nuclear Component Testing (NCT) Discussion Group emerged recently to clarify how ``a lowered-risk, reduced-cost approach can provide a progressive fusion environment beyond the ITER level to explore, discover, and help establish the remaining, critically needed physical and engineering sciences knowledge base for Demo.'' The group, assuming success of ITER and other contemporary projects, identified critical ``gap-filling'' investigations: plasma startup, tritium self-sufficiency, plasma facing surface performance and maintainability, first wall/blanket/divertor materials defect control and lifetime management, and remote handling. Only standard or spherical tokamak plasma conditions below the advanced regime are assumed to lower the anticipated physics risk to continuous operation (˜2 weeks). Modular designs and remote handling capabilities are included to mitigate the risk of component failure and ease replacement. Aspect ratio should be varied to lower the cost, accounting for the contending physics risks and the near-term R&D. Cost and time-effective staging from H-H, D-D, to D-T will also be considered. *Work supported by USDOE.

  18. Bridging sciatic nerve gap using tissue-engineered nerves constructed with neural tissue-committed stem cells derived from bone marrow

    Institute of Scientific and Technical Information of China (English)

    Zhiying Zhang; Congli Ren; Chuansen Zhang; Fang Liu; Liang Li

    2009-01-01

    BACKGROUND: Schwann cells are the most commonly used cells for tissue-engineered nerves. However, autologous Schwann cells are of limited use in a clinical context, and allogeneic Schwann cells induce immunological rejections. Cells that do not induce immunological rejections and that are relatively easy to acquire are urgently needed for transplantation.OBJECTIVE: To bridge sciatic nerve defects using tissue engineered nerves constructed with neural tissue-committed stem cells (NTCSCs) derived from bone marrow; to observe morphology and function of rat nerves following bridging; to determine the effect of autologous nerve transplantation, which serves as the gold standard for evaluating efficacy of tissue-engineered nerves.DESIGN, TIME AND SETTING: This randomized, controlled, animal experiment was performed in the Anatomical laboratory and Biomedical Institute of the Second Military Medical University of Chinese PLA between September 2004 and April 2006.MATERIALS: Five Sprague Dawley rats, aged 1 month and weighing 100-150 g, were used for cell culture. Sixty Sprague Dawiey rats aged 3 months and weighing 220-250 g, were used to establish neurological defect models. Nestin, neuron-specific enolase (NSE), glial fibrillary acidic protein (GFAP), and S-100 antibodies were provided by Santa Cruz Biotechnology, Inc., USA. Acellular nerve grafts were derived from dogs.METHODS: All rats, each with 1-cm gap created in the right sciatic nerve, were randomly assigned to three groups. Each group comprised 20 rats. Autograft nerve transplantation group: the severed 1-cm length nerve segment was reverted, but with the two ends exchanged; the proximal segment was sutured to the distal sciatic nerve stump and the distal segment to the proximal stump. Blank nerve scaffold transplantation group: a 1-cm length acellular nerve graft was used to bridge the sciatic nerve gap. NTCSC engineered nerve transplantation group: a 1-cm length acellular nerve graft, in which NTCSCs were

  19. 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...

  20. Bridge? What's a Bridge?

    Science.gov (United States)

    Gutsche, George

    1996-01-01

    Considers the metaphor of the "bridge" as it applies to Russian-language courses at the university level. The article examines broader curricular issues of technology, innovation, and outside pressures on language teaching. (22 references) (CK)

  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. Engineering characteristics of near-fault vertical ground motions and their effect on the seismic response of bridges

    Institute of Scientific and Technical Information of China (English)

    Li Xinle; Dou Huijuan; Zhu Xi

    2007-01-01

    A wide variety of near-fault strong ground motion records were collected from various tectonic environments worldwide and were used to study the peak value ratio and response spectrum ratio of the vertical to horizontal component of ground motion,focusing on the effect of earthquake magnitude,site conditions,pulse duration,and statistical component.The results show that both the peak value ratio and response spectrum ratio are larger than the 2/3 value prescribed in existing seismic codes,and the relationship between the vertical and horizontal ground motions is comparatively intricate.In addition,the effect of the near-fault ground motions on bridge performance is analyzed,considering both the material nonlinear characteristics and the P~△ effect.

  3. 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.

  4. Bridging the Gap between Engineering Design and PK-12 Curriculum Development through the Use of the STEM Education Quality Framework

    Science.gov (United States)

    Pinnell, Margaret; Rowly, James; Preiss, Sandi; Franco, Suzanne; Blust, Rebecca; Beach, Renee

    2013-01-01

    This paper will describe a unique partnership among the Department of Teacher Education and School of Engineering at the University of Dayton (UD) and the Dayton Regional STEM Center (DRSC). This partnership resulted in the development of the STEM Education Quality Framework (SQF), a tool to guide educators in teaching, learning and refining STEM…

  5. Examples of Solutions for Steel-Concrete Composite Structures in Bridge Engineering / Przykłady Konstrukcji Zespolonych W Budownictwie Mostowym

    Science.gov (United States)

    Flaga, Kazimierz; Furtak, Kazimierz

    2015-03-01

    The aim of the article [1] was to discuss the application of steel-concrete composite structures in bridge engineering in the aspect of structural design, analysis and execution. It was pointed out that the concept of steel-concrete structural composition is far from exhausted and new solutions interesting from the engineering, scientific and aesthetic points of view of are constantly emerging. These latest trends are presented against the background of the solutions executed in Poland and abroad. Particular attention is focused on structures of double composition and steel-concrete structures. Concrete filled steel tubular (CFST) structures are highlighted. W artykule [1] omówiono problemy konstrukcyjne, obliczeniowe i realizacyjne, związane z zastosowaniem konstrukcji zespolonych stal-beton w mostownictwie. Wskazano tam, że idea konstrukcyjnego zespolenia stali z betonem jest jeszcze daleka do wyczerpania i że wciąż pojawiają się nowe rozwiązania interesujące z inżynierskiego, naukowego i estetycznego punktu widzenia. W artykule niniejszym pokazano te nowoczesne trendy na tle rozwiązań zrealizowanych w Polsce i na świecie. Szczególną uwagę poświęcono konstrukcjom podwójnie zespolonym oraz konstrukcjom stalowobetonowym. Wyeksponowano tu szczególnie konstrukcje z rur stalowych wypełnionych betonem, typu CFST. Dają one nadzieję na ich szersze zastosowanie w warunkach polskich.

  6. Myocardial Bridging.

    Science.gov (United States)

    Yuan, Shi-Min

    2016-02-01

    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. PMID:27074276

  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. Research and Researchers in the Field of Works of Art and Historical Monuments. The School of Bridges and Roads in France -- the first school of engineers in this field in the world

    Directory of Open Access Journals (Sweden)

    Ana-Raluca Chiriac

    2006-01-01

    Full Text Available Romanian higher education began a long time ago, having its own national specificity but being also influenced by the education from other developed countries. Between 1813 -- 1840 Gh. Asachi created the School of Terminal Engineering, establi-shing the foundations of the Technical Engineering University. In Moldavia, higher education in engineering, in the field of roads and bridges, coincides with the official opening of the Faculty of Construction of Jassy, in 1941, as part of the Polytechnic Institute, today the „Gheorghe Asachi” Technical University. Over the years, this type of education has evolved and developed, under the influence of schools of engineering such as The School of Bridges and Roads in France. The French School of Bridges and Roads was created by a decree of the king, on the 14th of February 1747. In two and a half centuries, it has trained about 15,000 engineers, who accomplished great works both in their native country and abroad. The reputation of this school is based especially on the discoveries, the accomplishments and the activity of these engineers, who have a great impact on the development of this institution. Most of these engineers did not go down in history (we seldom know the name of the person who built a bridge or a road. We remember some of them by a formula, a machine, a plate on a road, without actually knowing who is the person behind the name. Shaping their portraits, we could bring them back to the memory of the public, emphasizing the common aspects of their professional training at the School of Bridges and Roads. A free professional background, of a high scientific level, comprising a lot of practical issues, based on public transport in the beginning, where reflection and action play an important part. Except a lot of great scientists (among them, a Nobel prize laureate, inventors, entrepreneurs, engineers with prestigious accomplishments, there are also politicians (even a president, writers

  9. Patterns of HCI design and HCI design of patterns bridging HCI design and model-driven software engineering

    CERN Document Server

    Seffah, Ahmed

    2015-01-01

    As interactive systems are quickly becoming integral to our everyday lives, this book investigates how we can make these systems, from desktop and mobile apps to more wearable and immersive applications, more usable and maintainable by using HCI design patterns. It also examines how we can facilitate the reuse of design practices in the development lifecycle of multi-devices, multi-platforms and multi-contexts user interfaces. Effective design tools are provided for combining HCI design patterns and User Interface (UI) driven engineering to enhance design whilst differentiating between UI

  10. The Influence of the Recommended LRFD Guidelines for the Seismic Design of Highway Bridges on Virginia Bridges

    OpenAIRE

    Widjaja, Matius Andy

    2003-01-01

    THE INFLUENCE OF THE RECOMMENDED LRFD GUIDELINES FOR THE SEISMIC DESIGN OF HIGHWAY BRIDGES ON VIRGINIA BRIDGES by Matius A. Widjaja Committee Chairwoman: Prof. Carin Roberts-Wollmann Civil Engineering (ABSTRACT) The influence of the recommended LRFD Guidelines for the seismic design of highway bridges in Virginia was investigated by analyzing two existing bridges. The first bridge has prestressed concrete girders and is located in the Richmond area. The second bridge has...

  11. 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....

  12. Programmevaluierung Bridge

    OpenAIRE

    Warta, Katharina; Good, Barbara; Geyer, Anton

    2009-01-01

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

  13. 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,...

  14. Theory of bridge aerodynamics

    CERN Document Server

    Strømmen, Einar

    2006-01-01

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

  15. Building Bridges

    DEFF Research Database (Denmark)

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

  16. The construction quality control on mass concrete of bridge engineering pile cap%桥梁工程承台大体积混凝土施工质量控制

    Institute of Scientific and Technical Information of China (English)

    赵喜红

    2012-01-01

    Taking Sichuan river super-big bridge project of Shanxi Huo-Yong highway western part as an example, this paper introduced in detail the construction quality control measures on mass concrete of bridge engineering pile cap from construction preparation, construction organization, construction method and other aspects, had guiding significance for future similar projects.%以山西省霍永高速公路西段城川河特大桥工程为例,从施工准备,前期工程施工组织,施工方法等方面入手,详细介绍了桥梁工程承台大体积混凝土施工质量控制措施,对今后同类工程具有参考意义。

  17. Stone bridges

    Czech Academy of Sciences Publication Activity Database

    Drdácký, Miloš; Slížková, Zuzana

    Prague : Institute of theoretical and applied mechanics AS CR, v.v.i, 2011 - (Drdácký, M.; Binda, L.; Hennen, I.; Kőpp, C.; Lanza, L.), s. 122-129 ISBN 978-80-86246-37-6 Grant ostatní: evropská komise(XE) CHEF-SSPI-044251 Institutional research plan: CEZ:AV0Z20710524 Keywords : flood * stone bridge * cultural heritage Subject RIV: AL - Art, Architecture, Cultural Heritage

  18. Bridge Aesthetics and Structural Honesty

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

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

  19. Monitoring of concrete bridges

    Czech Academy of Sciences Publication Activity Database

    Pirner, Miroš; Urushadze, Shota

    Orlando,Florida: Society for Experimental Mechanics, Inc, 2007 - (Wicks, A.), s. 250-257 ISBN 0-912053-97-6. [IMAC, Conference & Exposition on Structural Dynamics/25./. Orlando (US), 17.02.2007-19.02.2007] R&D Projects: GA MDS(CZ) 1F45D/013/120; GA ČR(CZ) GA103/05/2066 Institutional research plan: CEZ:AV0Z20710524 Keywords : Long-term measurements * Dynamic response * Bridge * Strain gauges * Rain-flow Subject RIV: JM - Building Engineering

  20. 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...

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

    OpenAIRE

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

    2009-01-01

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

  2. Cable Supported Bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    Cable supported bridges in the form of suspension bridges and cable-stayed bridges are distinguished by their ability to overcome large spans.The book concentrates on the synthesis of cable supported bridges, covering both design and construction aspects. The analytical part covers simple methods...

  3. The radiography of Swaythling Bridge

    International Nuclear Information System (INIS)

    The particular application of high energy radiography described in this paper was developed by the Harwell Nondestructive Testing Centre (NDTC) under the sponsorship of Radiation Dynamics Ltd, (RDL) who manufacture the 'Super-X' linear accelerator (Linac) used for the work. An initial evaluation determined the limits for thickness of concrete structures which could be radiographed with the linac under practical conditions. The technique was then applied to carry out a test on a bridge carrying a main trunk road over a small river in an urban environment. A situation which demanded the utmost care in deciding safety parameters and minimal disturbance to the surrounding environment. The safety parameters were defined by the Environmental and Medical Sciences Division of AERE Harwell (EMSc). The test was successfully carried out, within all the control parameters laid down beforehand, and very important engineering data were obtained for the Bridge Engineering Departments of Hampshire County Council and Southampton City Council. (author)

  4. 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...

  5. Bridge and brick motifs in complex networks

    Science.gov (United States)

    Huang, Chung-Yuan; Sun, Chuen-Tsai; Cheng, Chia-Ying; Hsieh, Ji-Lung

    2007-04-01

    Acknowledging the expanding role of complex networks in numerous scientific contexts, we examine significant functional and topological differences between bridge and brick motifs for predicting network behaviors and functions. After observing similarities between social networks and their genetic, ecological, and engineering counterparts, we identify a larger number of brick motifs in social networks and bridge motifs in the other three types. We conclude that bridge and brick motif content analysis can assist researchers in understanding the small-world and clustering properties of network structures when investigating network functions and behaviors.

  6. The frequency-dependent elements in the code SASSI: A bridge between civil engineers and the soil-structure interaction specialists

    Energy Technology Data Exchange (ETDEWEB)

    Tyapin, Alexander [Atomenergoproject, 7/1 Bakuninskaya Str., Moscow 105005 (Russian Federation)]. E-mail: Atyapin@bvcp.ru

    2007-07-15

    After four decades of the intensive studies of the soil-structure interaction (SSI) effects in the field of the NPP seismic analysis there is a certain gap between the SSI specialists and civil engineers. The results obtained using the advanced SSI codes like SASSI are often rather far from the results obtained using general codes (though match the experimental and field data). The reasons for the discrepancies are not clear because none of the parties can recall the results of the 'other party' and investigate the influence of various factors causing the difference step by step. As a result, civil engineers neither feel the SSI effects, nor control them. The author believes that the SSI specialists should do the first step forward (a) recalling 'viscous' damping in the structures versus the 'material' one and (b) convoluting all the SSI wave effects into the format of 'soil springs and dashpots', more or less clear for civil engineers. The tool for both tasks could be a special finite element with frequency-dependent stiffness developed by the author for the code SASSI. This element can represent both soil and structure in the SSI model and help to split various factors influencing seismic response. In the paper the theory and some practical issues concerning the new element are presented.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-01

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

  8. Influence of vehicles on bridge flutter and galloping

    Czech Academy of Sciences Publication Activity Database

    Pospíšil, Stanislav; Buljac, A.; Kuznetsov, Sergeii; Kozmar, H.

    New Taipei City : Tamkang University, 2015. s. 3-6 ISBN N Institutional support: RVO:68378297 Keywords : vehicle-wind bridge system * Kao-Pin Hsi Bridge * aeroelastic derivatives Subject RIV: JM - Building Engineering http://www.wind.org.tw/epaper/vj-attachment/2016/02/attach44.pdf

  9. Programmed Nanomaterial Assemblies in Large Scales: Applications of Synthetic and Genetically- Engineered Peptides to Bridge Nano-Assemblies and Macro-Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Matsui, Hiroshi

    2014-09-09

    Work is reported in these areas: Large-scale & reconfigurable 3D structures of precise nanoparticle assemblies in self-assembled collagen peptide grids; Binary QD-Au NP 3D superlattices assembled with collagen-like peptides and energy transfer between QD and Au NP in 3D peptide frameworks; Catalytic peptides discovered by new hydrogel-based combinatorial phage display approach and their enzyme-mimicking 2D assembly; New autonomous motors of metal-organic frameworks (MOFs) powered by reorganization of self-assembled peptides at interfaces; Biomimetic assembly of proteins into microcapsules on oil-in-water droplets with structural reinforcement via biomolecular recognition-based cross-linking of surface peptides; and Biomimetic fabrication of strong freestanding genetically-engineered collagen peptide films reinforced by quantum dot joints. We gained the broad knowledge about biomimetic material assembly from nanoscale to microscale ranges by coassembling peptides and NPs via biomolecular recognition. We discovered: Genetically-engineered collagen-like peptides can be self-assembled with Au NPs to generate 3D superlattices in large volumes (> μm{sup 3}); The assembly of the 3D peptide-Au NP superstructures is dynamic and the interparticle distance changes with assembly time as the reconfiguration of structure is triggered by pH change; QDs/NPs can be assembled with the peptide frameworks to generate 3D superlattices and these QDs/NPs can be electronically coupled for the efficient energy transfer; The controlled assembly of catalytic peptides mimicking the catalytic pocket of enzymes can catalyze chemical reactions with high selectivity; and, For the bacteria-mimicking swimmer fabrication, peptide-MOF superlattices can power translational and propellant motions by the reconfiguration of peptide assembly at the MOF-liquid interface.

  10. Indirect bridge frequency measurement: an experimental verification

    Czech Academy of Sciences Publication Activity Database

    Urushadze, Shota; Yau, J.-D.; Frýba, Ladislav

    Changsha: DEStech Publications., 2015. s. 48-48 ISBN N. [International conference on mechanical science and mechanical design (MSMD2015). 12.12.2015-13.12.2015, Changsha] R&D Projects: GA ČR(CZ) GC13-34405J Institutional support: RVO:68378297 Keywords : bridge health monitoring * indirect method * moving load * VBI Subject RIV: JM - Building Engineering

  11. Building Bridges, Robots, and High Expectations

    Science.gov (United States)

    Bennie, Fiona; Corbett, Charlotte; Palo, Angela

    2015-01-01

    This article describes an after-school program at the Horace Mann School for the Deaf (HMS), the oldest public day school for deaf students in the United States, where almost half of the student body imagined and created bridge and robotic machines. The Deaf Robotics Engineering and Math Team, or the DREAM Team club, included HMS students in…

  12. Fatigue problems of steel bridges

    Czech Academy of Sciences Publication Activity Database

    Urushadze, Shota; Frýba, Ladislav; Škaloud, Miroslav; Pirner, Miroš; Zörnerová, Marie

    Stirlingshire : Civil-Comp Press, 2012 - (Pombo, J.), s. 142-151 ISBN 978-1-905088-53-9. ISSN 1759-3433. [International Conference on Railway Technology: Research, Development and Maintenance /1./. Las Palmas de Gran Canaria (ES), 18.04.2012-20.04.2012] R&D Projects: GA MŠk(CZ) 7E08098 Grant ostatní: evropská komise(XE) RFSR-CT-2008-00033 (BRIFAG); GA ČR(CZ) GA103/08/1340 Institutional support: RVO:68378297 Keywords : steel bridges * fatigue * S-N curve * orthotropic deck * web breathing Subject RIV: JM - Building Engineering

  13. Application of Safety Risk Evaluation in Railway and Bridge Engineering%安全风险评价在铁路桥梁工程中的应用

    Institute of Scientific and Technical Information of China (English)

    王晓

    2014-01-01

    文章以京沪高铁项目施工安全风险管理为例,展开了在项目管理过程中如何进行风险管理,在风险管理的过程中如何识别风险、分析风险、控制风险和应对风险,重点介绍了铁路工程项目风险管理中安全风险评价的应用。%The paper taking the management of construction safety risk of the high-speed road between Beijing and Shang-hai as an example, launched to make risk management in the project management process and put forward measures on how to identify risk, to analyze risk, to control risk and to deal with the risk in the process of risk management. The paper focused on the application of safety risk evaluation of risk management in railway engineering project.

  14. Generalized Gaussian Bridges

    CERN Document Server

    Sottinen, Tommi

    2012-01-01

    A generalized bridge is the law of a stochastic process that is conditioned on linear functionals of its path. We consider two types of representations of such bridges: orthogonal and canonical. In the canonical representation the filtrations and the linear spaces generated by the bridge process and the original process coincide. In the orthogonal representation the bridge is constructed from the entire path of the underlying process. The orthogonal representation is given for any continuous Gaussian process but the canonical representation is given only for so-called prediction-invertible Gaussian processes. Finally, we apply the canonical bridge representation to insider trading by interpreting the bridge from an initial enlargement of filtration point of view.

  15. 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.

  16. Concrete bridge prioritization system

    OpenAIRE

    Kesselring, Debbie Anne

    1995-01-01

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

  17. 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....

  18. 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...

  19. Engineering mechanics

    CERN Document Server

    Gross, Dietmar; Schröder, Jörg; Wall, Wolfgang A; Rajapakse, Nimal

    Statics is the first volume of a three-volume textbook on Engineering Mechanics. The authors, using a time-honoured straightforward and flexible approach, present the basic concepts and principles of mechanics in the clearest and simplest form possible to advanced undergraduate engineering students of various disciplines and different educational backgrounds. An important objective of this book is to develop problem solving skills in a systematic manner. Another aim of this volume is to provide engineering students as well as practising engineers with a solid foundation to help them bridge the gap between undergraduate studies on the one hand and advanced courses on mechanics and/or practical engineering problems on the other. The book contains numerous examples, along with their complete solutions. Emphasis is placed upon student participation in problem solving. The contents of the book correspond to the topics normally covered in courses on basic engineering mechanics at universities and colleges. Now in i...

  20. Professional Formation of Engineers: Enhancing the First Year Student Experience

    OpenAIRE

    Goold, Eileen

    2015-01-01

    This paper reports on a study investigating engineering students’ perceptions of engineering practice and whether engineering students’ cognitive engagement benefits from bridging the gap between the technical issues in their education and the practical realities of modern engineering practice.

  1. The floating water bridge

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2016-04-26

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

  3. 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

  4. Bridge Management Systems:present and future

    OpenAIRE

    Thoft-Christensen, Palle

    1997-01-01

    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.

  5. Bridging a cultural gap

    Science.gov (United States)

    Leviatan, Talma

    2008-09-01

    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 potential bridging programme, this paper aims at demonstrating that the gap can be bridged, by presenting an ongoing modular bridging programme especially designed for the diverse types of student populations in teachers training colleges. We also present here some innovative teaching and assessment methods that were judged essential for the success of these programmes—focusing mainly on the "Questionnaire Based Instruction Method". Finally we suggest directions of follow up and research.

  6. 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...

  7. ENGINEERING GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20110579 Cao Shenghua(Construction Headquarters of Sutong Yangtze River Bridge,Nanjing 210001,China)A Preliminary Study on Engineering Characters of Interbedded Soils in Littoral and River Facies(Journal of Geology,ISSN1674-3636,CN32-1796/P,34(1),2010,p.61-66,4 illus.,3 tables,5 refs.,with English abstract)Key words:cohesive soil,soil mechanics 20110580 Chen Shangrong(Shanghai Geological

  8. Integral Abutment and Jointless Bridges

    OpenAIRE

    Cristian-Claudiu Comisu

    2005-01-01

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

  9. Influence of vehicles on bridge aeroelastic stability

    Czech Academy of Sciences Publication Activity Database

    Buljac, Andrija; Pospíšil, Stanislav; Kozmar, H.; Kuznetsov, Sergeii; Král, Radomil

    Rijeka: Grafika Helvetica, 2015 - (Kožar, I.; Bićanić, N.; Jelenić, G.; Čanadija, M.), s. 17-17 ISBN 9789537539214. [International Congress of Croatian Society of Mechanics /8./. Opatija (HR), 29.09.2015-02.10.2015] R&D Projects: GA MŠk(CZ) LO1219 Keywords : wind * vehicles * bridge * aeroelastic stability Subject RIV: JM - Building Engineering

  10. Bridge SHM system based on fiber optical sensing technology

    Science.gov (United States)

    Li, Sheng; Fan, Dian; Fu, Jiang-hua; Huang, Xing; Jiang, De-sheng

    2015-09-01

    The latest progress of our lab in recent 10 years on the area of bridge structural health monitoring (SHM) based on optical fiber sensing technology is introduced. Firstly, in the part of sensing technology, optical fiber force test-ring, optical fiber vibration sensor, optical fiber smart cable, optical fiber prestressing loss monitoring method and optical fiber continuous curve mode inspection system are developed, which not only rich the sensor types, but also provides new monitoring means that are needed for the bridge health monitoring system. Secondly, in the optical fiber sensing network and computer system platform, the monitoring system architecture model is designed to effectively meet the integration scale and effect requirement of engineering application, especially the bridge expert system proposed integration of sensing information and informatization manual inspection to realize the mode of multi index intelligence and practical monitoring, diagnosis and evaluation. Finally, the Jingyue bridge monitoring system as the representative, the research on the technology of engineering applications are given.

  11. Assessment of Infrared Thermography for NDE of FRP Bridge Decks

    OpenAIRE

    Miceli, Marybeth

    2000-01-01

    Statistics released in the fall 1989 showed that 238,357 (41%) of the nation's 577,710 bridges are either structurally deficient or functionally obsolete. New materials, such as fiber reinforced polymeric composites (FRP), are being suggested for use in bridge systems to solve some of the current problems. These materials are thought to be less affected by corrosive environmental conditions than conventional civil engineering materials. Therefore they may require less maintenance and provi...

  12. The calculation of noise from railway bridges and viaducts

    OpenAIRE

    Bewes, Oliver Guy

    2005-01-01

    Pandrol Rail Fastenings Limited are a designer and manufacturer of railway rail-fastening systems. As an organisation they have the capability to reduce the noise impact of bridges using resilient track components. They also have a commercial interest in providing such technology. Knowledge of the processes behind bridge noise is important to Pandrol in two ways; to aid the engineers within the organisation in the design of fastening systems and to demonstrate a state-of-the-ar...

  13. Surface salt bridges stabilize the GCN4 leucine zipper.

    OpenAIRE

    Spek, E. J.; Bui, A. H.; Lu, M.; Kallenbach, N R

    1998-01-01

    We present a study of the role of salt bridges in stabilizing a simplified tertiary structural motif, the coiled-coil. Changes in GCN4 sequence have been engineered that introduce trial patterns of single and multiple salt bridges at solvent exposed sites. At the same sites, a set of alanine mutants was generated to provide a reference for thermodynamic analysis of the salt bridges. Introduction of three alanines stabilizes the dimer by 1.1 kcal/mol relative to the wild-type. An arrangement c...

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

    International Nuclear Information System (INIS)

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

  15. 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 are...

  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. 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.

  18. Building Migratory Bridges

    Science.gov (United States)

    Roy, Michael; Doss, Laurie K.

    2007-01-01

    The Building Migratory Bridges (BOMB) program--a collaboration between the Marvel wood School and Audubon Sharon in Connecticut and Conservation Research Education Action (CR EA), a U.S. not-for-profit in Panama--uses nontropical migratory bird research in the United States and Panama to demonstrate how negative environmental impacts in one…

  19. Quantum Bidding in Bridge

    Science.gov (United States)

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

    2014-04-01

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

  20. Bridge of Light

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

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

  1. 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...

  2. The Ultrasonic Testing of the Yangtze River Terraces Bridge Foundation Engineering Analysis of Packet of Sand Case in Acoustic Pipe%长江阶地桥梁桩基工程超声波检测声测管包沙案例分析

    Institute of Scientific and Technical Information of China (English)

    王俊丽; 徐军

    2012-01-01

      Yangtze River Bridge construction is often located in the Yangtze River terraces, and the Yangtze River terraces with the characteristics of thick sand.Wuhan Yangtze River Bridge Pile Foundation Engineering uses ultrasonic nondes-tructive testing technology to detect al pile foundation, and as wel as uses ultrasonic testing, coring and borehole excavation in a comprehensive way, and then makes detailed identification of individual pile foundation shal ow acoustic tube wrapped Sand Mission , clod phenomenon, to ensure the quality of the pile foundation engineering,which has a good reference for similar projects.%  长江大桥的施工往往位于长江阶地,长江阶地具有砂层厚的特点。武汉某长江大桥桥梁桩基工程采用超声波无损检测技术,对所有桩基进行检测,并采用超声波检测、钻芯和凿洞开挖等综合手段,详细查明个别桩基浅部声测管包裹沙团、泥块的现象,保证了桩基工程质量,对类似工程具有很好的借鉴性。

  3. Revised Rules for Concrete Bridges

    DEFF Research Database (Denmark)

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

    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....

  4. Improvement on design analyses of composite steel-concrete bridges using elaborate finite element methods

    Directory of Open Access Journals (Sweden)

    Jaturong Sanguanmanasak

    2010-07-01

    Full Text Available In this paper, three-dimensional finite element analysis of composite steel-concrete bridges is performed to simulate theactual bridge behavior. The accuracy of the model is verified against the results acquired from a field test. Thai trucks are loaded at possible locations of the bridge in order to obtain the maximum stresses on the bridge. The influences of concrete barriers, the displacement of bridge piers, and the Young’s modulus of concrete are then discussed, to reveal the actual behavior of the steel-concrete composite bridge. The reactions at the bearings on the bridge piers are also evaluated and discussed in this conjunction. Good agreement is obtained between the models and loading tests to show that the finite element model can aid engineers in design practices.

  5. On the Performance of Super-Long Integral Abutment Bridges: Parametric Analyses and Design Optimization

    OpenAIRE

    Lan, Cheng

    2012-01-01

    The concept of "integral abutment bridge" has recently become a topic of remarka-ble interest among bridge engineers, not only for newly built bridges but also during refurbishment processes. The system constituted by the substructure and the superstructure can achieve a composite action responding as a single structural unit; the elimination of expansion joint and bearings on the abutments, greatly reduce the construction and maintenance costs. To maximize the benefits from integral abutment...

  6. [Retention of adhesive bridges].

    Science.gov (United States)

    Raes, F; De Boever, J

    1994-04-01

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

  7. Nasal Bridge Intramuscular Hemangioma

    OpenAIRE

    Zulkifli Hamir Basah; Irfan Mohamad; Ramiza Ramza Ramli; Maha Khadum Gayadh; Samarendra Singh Mutum

    2015-01-01

    Intramuscular haemangioma (IMH) is a benign mesenchymal tumour. It appears as a deep, nontender mass within the soft tissue, particularly in the extremities. This tumour may not be obvious on clinical examination. Head and neck IMHs represent only 13.5% of the total IMHs. The most common site for a head and neck IMH is the masseter muscle, followed by trapezius, sternocleidomastoid, and very rarely temporalis muscle. We present a patient with left nasal bridge swelling which was excised and h...

  8. BRIDGING SERVICE QUALITY GAPS

    OpenAIRE

    BARKATH UNISSA

    2012-01-01

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

  9. 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.

  10. Nematic liquid crystal bridges

    Science.gov (United States)

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

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

  11. Wind Resistant Design of Bridges in Japan Developments and Practices

    CERN Document Server

    Fujino, Yozo; Tanaka, Hiroshi

    2012-01-01

    For long-span bridges, wind action is a dominant factor in their safety and serviceability. A large number of long-span bridges have been built in Japan over the past 30 years, and tremendous amounts of research and technical development have been accomplished in wind resistant design. This book is a compilation of the results of active research and development. Wind resistant design standards generated in Japan are described in the first few chapters. Then comes information such as design wind speed, structural damping, wind tunnel tests, and analyses, which provide the basis of the design standards. Wind-induced vibrations and their control of girders, towers, cables, and other features are explained with examples of field measurements. Comprehensive listings of Japanese experience in vibration control are also presented. Because achieving particularly dynamic safety against wind is still not an easy task, these data and information will be valuable assets for the wind-engineering and bridge-engineering com...

  12. Problems of lamella flanges in steel bridge construction

    Czech Academy of Sciences Publication Activity Database

    Křístek, V.; Škaloud, Miroslav; Kunrt, J.; Urushadze, Shota

    Prague : Institute of theoretical and applied mechanics, Academy of Sciences of the Czech Republic, v. v. i., 2015 - (Náprstek, J.; Fischer, C.). s. 164-165 ISBN 978-80-86246-42-0. ISSN 1805-8248. [Engineering mechanics 2015 /21./. 11.05.2015-14.05.2015, Svratka] R&D Projects: GA ČR(CZ) GC13-34405J Institutional support: RVO:68378297 Keywords : bridges * lamella flanges * repeated loading * breathing * limit states Subject RIV: JM - Building Engineering

  13. Reverse engineering for quality systems

    International Nuclear Information System (INIS)

    When the age of software engineering began, many companies were faced with a problem of how to support the older, pre-software-engineering, programs. The techniques of reverse engineering and re-engineering were developed to bridge the gap between the past and the present. Although reverse engineering can be used for generating missing documentation, it can also be used as a means to demonstrate quality in these older programs. This paper presents, in the form of a case study, how Rolls-Royce and Associates Limited addressed the quality issues of reverse engineering and re-engineering. (author)

  14. Experimental and theoretical studies of indirect bridge frequency measurement using a passing vehicle

    Czech Academy of Sciences Publication Activity Database

    Urushadze, Shota; Yau, J. D.; Frýba, Ladislav

    New Taipei City : Tamkang University, 2015 ISBN N R&D Projects: GA ČR(CZ) GC13-34405J Institutional support: RVO:68378297 Keywords : indirect method * bridge health monitoring * moving load * VBI Subject RIV: JM - Building Engineering

  15. 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...

  16. Design of a single-track railway network arch bridge : According to the Eurocodes

    OpenAIRE

    Varennes, Maxime

    2011-01-01

    A constant research of more ecological and efficient structures has enabled bridges to be more innovative through the years. Nowadays, as the need is greater than ever, a new kind of bridge is expanding in the entire world: the network arch bridges. The concept was developed by professor and engineer Per Tveit in 1955 and has been improved since then. But it is only for 10 years that many bridges of this sort have been built. The aim of the thesis is to investigate the structural behavior of ...

  17. Nondestructive testing for bridge diagnosis

    International Nuclear Information System (INIS)

    There are many motivations for bridge diagnosis using Nondestructive testing (NDT) to monitor its integrity. The measured frequency and damping on real bridge are compared in one figure as a function of span length and general aspects are explained. These date were measured in every construction of bridges and applied to design new bridges. Ultrasonic testing is also well used for concrete and steel members mainly to detect internal damages or delaminations. Detail analysis on reflected waves gives us more accurate information about the defect. Experimental results are shown as examples in this paper.

  18. 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...

  19. Comparative Research of Extra-large-span Cable-stayed Bridge with Steel Truss Girder and Steel Box Girder

    OpenAIRE

    Tan Manjiang; Bai Zhizhou; Chen Dewei

    2015-01-01

    To research structural performance of extra-large-span cable-stayed bridge under different section forms, with the engineering background of a 800m main-span cable-stayed bridge with steel truss girder, the cable-stayed bridge with steel box girder is designed according to the current bridge regulations when two bridges are designed in an ultimate state of the carrying capacity, so the maximum stress and minimum stress of the stress envelope diagram are substantially the same. A comprehensive...

  20. 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

    The concept of sustainable construction has attracted an increased attention. Bridge infrastructures and their belonged construction activities consume considerable material and energy, which is responsible for large environmental burdens. However, the environmental assessment of bridges has 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...

  1. Aesthetic design of bridges; Kyoryo ni okeru keikan sekkei no rekishi

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, H. [Kyushu Institute of Technology, Kitakyushu (Japan)

    1995-01-01

    The present paper outlines the bridge design in harmony with both ambient and natural environments. The condition which the bridge must clear has its two phases, i.e., `rational phase` focused on the practical utility to be managed by the engineering and `sensible phase` for the aesthetic achievement. The profile and scenery of bridge are based on the perfect teleology to engineer and process them by taking the influence into consideration on the mental phase. The beauty of bridge belongs to a category of technical beauty converting the technical product into an aesthetic object. The technical beauty is composed of `formal beauty` (The composition of all different members forms the beauty of harmony.), `functional beauty` (All different members under tension generate the dynamic beauty.) and `harmony with the environment`. For the harmony with the environment, what is taken into consideration is the steel, concrete and other material feeling, type of bridge adaptable to the environment, and color good for the environment. The following three methods are applied to the combination of bridge and environment: elimination method to vaguely immerse the bridge in the environment. Accentuation method to select the bridge as a main element of scenery. Harmonization method to harmonize the bridge with the environment. 21 refs., 14 figs.

  2. DRAFT MODEL FOR CREATING A FINANCIAL INDICATORS OF BRIDGE CONSTRUCTION

    Directory of Open Access Journals (Sweden)

    Iveta Strelcova

    2016-04-01

    Full Text Available The paper deals with a problem of developing, defining and applying budgetary indicators of engineering constructions, and particularly bridges. It is a draft of a Model for development of budgetary indicators of bridge construction in the pre-investment phase of a project. It could, according to classification and evaluation in terms of criteria and search for the most accurate valuation unit of complex structures such as bridge construction, serve investors and public administration authorities for rapid investment planning and professional control of completed buildings. Such a unique tool has never been developed in the Czech Republic so far. Bridges as buildings complement any landscape and in the outer parts of cities, they often establish a viewpoint. They belong among important parts of any highway or expressway. Without them, it would be impossible to establish grade-separated crossings with other roads - roads, railway lines or sections of rivers. They are also important in overcoming obstacles of natural and artificial character such as deep valleys, lakes, or steep mountainsides. The aim of the paper is to analyse a current state of the valuation of bridges and the subsequent establishment and validation of the Model for the development of budgetary indicators of the bridge construction.

  3. Advanced materials for control of post-earthquake damage in bridges

    International Nuclear Information System (INIS)

    This paper presents analytical modeling to study the seismic response of bridge systems with conventional and advanced details. For validation, a 33 m quarter-scale model of a four-span bridge incorporating innovative materials and details seismically tested on the shake tables at the University of Nevada, Reno was taken. The bridge specimen involved use of advanced materials and details to reduce damage at plastic hinges and minimize residual displacements. A three-dimensional, nonlinear model incorporating the response of the innovative materials was developed to study the bridge response using the finite-element software OpenSees. Existing finite-element formulations were used to capture the response of the advanced materials used in the bridge. The analytical model was found to be able to reproduce comparable bent displacements and bent shear forces within reasonable accuracy. The validated model was further used to study different types of bridges under suite of scaled bi-directional near-fault ground motions. Comparisons were made on behavior of five different bridge types, first conventional reinforced concrete bridge, second post-tensioned column bridge, third bridge with elastomeric rubber elements at the plastic hinge zone, fourth bridge with nickel–titanium superelastic shape memory alloy (SMA) reinforcing bar and fifth bridge with CuAlMn superelastic SMA reinforcing bar. Both the SMA used bridges also utilized engineered cementitious composite element at the plastic hinge zone. The results showed effectiveness of the innovative interventions on the bridges in providing excellent recentering capabilities with minimal damage to the columns. (paper)

  4. 南澳大桥工程技术代管组织管理模式应用研究%Application research of organization management mode of Nan’ao bridge engineering technology escrow

    Institute of Scientific and Technical Information of China (English)

    傅光奇; 蔡奕生; 袁永平; 陈俊生; 田又强

    2015-01-01

    Taking Nan’ao bridge project in Guangdong province as an example,on the basis of describing technology escrow connotation and characteristics,the paper analyzes its organization mode,discusses characteristics of technology escrow mode,which has provided some basis for organization management of other governmental-invested facility project in other fields.%以广东省南澳大桥项目为例,在深入阐述技术代管的内涵和特点的基础上,分析了其组织模式,并据此提炼了技术代管模式的特点,为日后海上超长桥梁工程,甚至其他领域政府投资基础设施项目的组织管理提供了实例性依据。

  5. 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 wi...

  6. 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 endan...

  7. Studies on Technical Development of Railway Steel-Concrete Composite Cirider Bridges in China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Steel-concrete composite girder bridge boasts the advantages of strong rigidity,low noise and low construction height.Along with the large-scale construction of passengerdedicated lines (PDL) and high-speed lines (HSL),tests and researches on steel-concrete composite girder bridges have been conducted with the main types of which including steel plate girder-concrete composite girder bridge,deck steel truss girder-concrete composite girder bridge,through steel truss girder-concrete composite girder bridge and through type tied arch composite girder bridge.Based on the application and researches on steel-concrete composite technology and in combination with the engineering construction of railway bridges,the construction of HSL and PDL and upgrading of existing lines for speed-up in China,this paper analyzes the main structural forms of through steel truss girder-concrete composite girder bridges with different spans and structure systems,carries out studies on the force acted upon these bridges and the related theory and methods for design and computation,and puts forward the solutions required in relation to the key technologies for further development of railway steel-concrete composite girder bridges.

  8. Fuzzy Based Decision Support System for Condition Assessment and Rating of Bridges

    Science.gov (United States)

    Srinivas, Voggu; Sasmal, Saptarshi; Karusala, Ramanjaneyulu

    2016-06-01

    In this work, a knowledge based decision support system has been developed to efficiently handle the issues such as distress diagnosis, assessment of damages and condition rating of existing bridges towards developing an exclusive and robust Bridge Management System (BMS) for sustainable bridges. The Knowledge Based Expert System (KBES) diagnoses the distresses and finds the cause of distress in the bridge by processing the data which are heuristic and combined with site inspection results, laboratory test results etc. The coupling of symbolic and numeric type of data has been successfully implemented in the expert system to strengthen its decision making process. Finally, the condition rating of the bridge is carried out using the assessment results obtained from the KBES and the information received from the bridge inspector. A systematic procedure has been developed using fuzzy mathematics for condition rating of bridges by combining the fuzzy weighted average and resolution identity technique. The proposed methodologies and the decision support system will facilitate in developing a robust and exclusive BMS for a network of bridges across the country and allow the bridge engineers and decision makers to carry out maintenance of bridges in a rational and systematic way.

  9. Superconductivity in small metal bridges

    International Nuclear Information System (INIS)

    Josephson effects in weaklinks are discussed for low and high frequency regimes using simple perturbation techniques. It is proven that no measurement of the supercurrent dependence upon frequency above the Riedel peak frequency can be made using rf sources whose frequencies are below the Riedel peak. Thus the bulk of work done in the field on the high frequency structure of the Josephson current is shown to be invalid. Metal bridges shorter than a newly defined temperature independent length for superconductors, l/sub PHONON/, are proven to be identical in their Josephson current behavior to tunneling junctions. The BCS gap equation is generalized to include voltage gradient effects on pairs within the bridge. The oscillation frequency for long bridges (l/sub BRIDGE/ greater than l/sub PHONON/) is shown to be limited to less than 10'' Hz. An experimental test of the new voltage dependent gap is made as well as tests of the pair reforming time of bridges

  10. Bridge Coupler for APT

    CERN Document Server

    Greninger, P T; Spalek, G; Greninger, Paul T.; Rodarte, Henry J.

    2000-01-01

    The Coupled Cavity Drift Tube Linac (CCDTL) used in the Accelerator for the Production of Tritium (APT) is fully described elsewhere [1]. The modules are composed of several machined and brazed segments that must account for the accumulation of dimensional tolerances in the build up of the stack. In addition, space requirements dictate that power fed to the accelerator cannot be through the accelerating cavities. As well, we would like to remove a single segment of the accelerator without removing additional segments. These requirements combined with phasing relationships of the design and space limitations have resulted in a different bridge coupling method used in the module comprising 3-gap segments. The coupling method, phasing relationships and other features that enhance the flexibility of the design will be discussed.

  11. Half Bridge Inductive Heater

    Directory of Open Access Journals (Sweden)

    Zoltán GERMÁN-SALLÓ

    2015-12-01

    Full Text Available Induction heating performs contactless, efficient and fast heating of conductive materials, therefore became one of the preferred heating procedure in industrial, domestic and medical applications. During induction heating the high-frequency alternating currents that heat the material are induced by means of electromagnetic induction. The material to be heated is placed inside the time-varying magnetic field generated by applying a highfrequency alternating current to an induction coil. The alternating electromagnetic field induces eddy currents in the workpiece, resulting resistive losses, which then heat the material. This paper describes the design of a power electronic converter circuit for induction heating equipment and presents the obtained results. The realized circuit is a low power half bridge resonant inverter which uses power MOS transistors and adequate driver circuits.

  12. Nanoparticle bridge DNA biosensor

    Science.gov (United States)

    Huang, Hong-Wen

    A new DNA sensing method is demonstrated in which DNA hybridization events lead to the formation of nanoparticle satellites that bridge two electrodes and are detected electrically. The hybridization events are exclusively carried out only on specific locations, the surfaces of C-ssDNA modified 50 nm GNPs. The uniqueness of this work is that only a small number of T-ccDNA molecules (target DNA and three-base-pair-mismatched DNA in 20nM concentrations. Three single-stranded DNA (ssDNA) system is used in our experiment which includes Capture-ssDNA (C-ssDNA), Target-ssDNA (T-ssDNA) and Probe-ssDNA (P-ssDNA). Both C-ssDNA and P-ssDNA are modified by a thiol group and can hybridize with different portions of T-ssDNA. T-ssDNA requires no modification in three ssDNA system, which is beneficial in many applications. C-ssDNA modified 50nm gold nanoparticle (C-50au) and P-ssDNA modified 30nm gold nanoparticle (P-30au) are prepared through the reaction of thiol-gold chemical bonding between thiolated ssDNA and gold nanoparticle (GNP) (C-ssDNA with 50nm GNP, P-ssDNA with 30nm GNP). We controllably place the C-50au only on the SiO2 band surface (˜ 90nm width) between two gold electrodes (source and drain electrodes) by forming positively- and negatively-charged self-assembled monolayers (SAMs) on SiO2 and gold surface, respectively. DNA modified GNP is negatively charged due to ionization of phosphate group on DNA back bone. C-50au therefore is negatively charged and can only be attracted toward SiO2 area (repelled by negatively charged gold electrode surface). The amine group of positively-charged SAMs on SiO2 surface is then passivated by converting to non-polar methyl functional group after C-50au placement. P-30au is first hybridized with T-ssDNA in the solution phase (T-P- 30au formed) and is introduced into DNA detection device in which C-50au are immobilized on ˜90nm width SiO2 band (between two gold electrodes). The passivation step ensures every TP-30au are attached

  13. 'THERMO-BRIDGE' between East and West for technology transfer and information exchange. 16. International conference on Thermal engineering and thermogrammetry (THERMO) with Exhibition and Pre-Session on Thermal Energy in Hungarian

    International Nuclear Information System (INIS)

    It was already organized as the International Conference on Thermal Engineering and Thermogrammetry (THERMO) in 1987. This conference is a series of biennial meetings. The developments of measurement theory and technologies help the energy-conscious design of thermal engineering equipment and processes as well as the better understanding of thermal phenomena in living organism. The conference will cover topics both the field of theory and application including nem measurements concepts; transducer technique mapping; contact, optical and IR imaging; biomedical and biotechnological applications; thermal informatics, automatic methods and systems for industrial energy management and process control; heat loss detection and analysis; heat and mass transfer; utilization of alternative energy; thermophysical properties as well as the common practice of thermal engineering. The programme included more than 40 papers from 19 countries. On the three days of oral presentation and poster workshops are organized whose topics will cover the following fields: Heat and mass transfer, thermotechnics; combustion and environmental protection; thermogravimetry; thermomechanics and defectometry; Infrared imagery and analysis, thermodynamics; practice of thermal engineering; medicine and biology. During the conference there were an exhibition of scientific and industrial instrumentation in the conference hall. (S.I.)

  14. Liquid-Bridge Breaking Limits

    Science.gov (United States)

    Macner, Ashley; Steen, Paul

    2011-11-01

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

  15. Comparative Research of Extra-large-span Cable-stayed Bridge with Steel Truss Girder and Steel Box Girder

    Directory of Open Access Journals (Sweden)

    Tan Manjiang

    2015-01-01

    Full Text Available To research structural performance of extra-large-span cable-stayed bridge under different section forms, with the engineering background of a 800m main-span cable-stayed bridge with steel truss girder, the cable-stayed bridge with steel box girder is designed according to the current bridge regulations when two bridges are designed in an ultimate state of the carrying capacity, so the maximum stress and minimum stress of the stress envelope diagram are substantially the same. A comprehensive comparison is given to two types of bridge on the aspect of static force, natural vibration frequency, stability, economic performance and so on. Analysis results provide future reference for the large-span cable-stayed bridge to select between the steel truss girder and the steel box girder.

  16. 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...

  17. 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...

  18. 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]....

  19. Bridging the urological divide.

    Science.gov (United States)

    Roberts, Robin

    2011-09-23

    The advanced disease clinical presentations, higher morbidity and mortality rates and lack of available treatment options in prostate cancer care, attest to disparities in the delivery and outcomes of urological services in Black men of African lineage in both the Developed and Developing countries. This gap in health care and services in the global management of prostate cancer denotes the urological divide.Through the experience of a Developing country urologist with a comparative literature review, this presentation defines the determinants of the disparity through deficiencies in human, material and financial resources, as is most prevalent in Developing countries.Solutions to ending health care disparities must take into account the existing development phase of Third World countries and thus determine whether the Developed countries should export a total service delivery system or seek primarily to advance the competence and skills of the existing Developing country resources.Collaboration in prostate cancer research has the greatest promise and sustainability of bridging this urological divide and is of mutual benefit to both entities. PMID:21992183

  20. 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.

  1. Bridge Culture of Langde Village

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

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

  2. 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...

  3. Applications of overburden conveyor bridges

    Energy Technology Data Exchange (ETDEWEB)

    Schachtschneider, H.

    1987-06-01

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

  4. Performance-based concept on seismic evaluation of existing bridges

    Institute of Scientific and Technical Information of China (English)

    Yu-Chi Sung; Wen-I Liao; W.Phillip Yen

    2009-01-01

    Conventional seismic evaluation of existing bridges explores the ability of a bridge to survive under significant earthquake excitations. This approach has several major drawbacks, such as only a single structural performance of near collapse is considered, and the simplified approach of adopting strength-based concept to indirectly estimate the nonlinear behavior of a structure lacks accuracy. As a result, performance-based concepts that include a wider variety of structural performance states of a given bridge excited by different levels of earthquake intensity is needed by the engineering community. This paper introduces an improved process for the seismic evaluation of existing bridges. The relationship between the overall structural performance and earthquakes with varying levels of peak ground acceleration (PGA) can successfully be linked. A universal perspective on the seismic evaluation of bridges over their entire life-cycle can be easily obtained to investigate multiple performance objectives. The accuracy of the proposed method, based on pushover analysis, is proven in a case study that compares the results from the proposed procedure with additional nonlinear time history analyses.

  5. ANGIOGRAPHIC ASPECTS OF MYOCARDIAL BRIDGES

    Directory of Open Access Journals (Sweden)

    Sujatha. M

    2015-12-01

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

  6. 9th Structural Engineering Convention 2014

    CERN Document Server

    2015-01-01

    The book presents research papers presented by academicians, researchers, and practicing structural engineers from India and abroad in the recently held Structural Engineering Convention (SEC) 2014 at Indian Institute of Technology Delhi during 22 – 24 December 2014. The book is divided into three volumes and encompasses multidisciplinary areas within structural engineering, such as earthquake engineering and structural dynamics, structural mechanics, finite element methods, structural vibration control, advanced cementitious and composite materials, bridge engineering, and soil-structure interaction. Advances in Structural Engineering is a useful reference material for structural engineering fraternity including undergraduate and postgraduate students, academicians, researchers and practicing engineers.

  7. ANGIOGRAPHIC ASPECTS OF MYOCARDIAL BRIDGES

    OpenAIRE

    Sujatha M; V Subhadra Devi; C. S. S. Raju; B. Yugandhar; Nagaraju

    2015-01-01

    Introduction: The segment of epicardial coronary artery that traverses intramurally through the myocardium and bridged by a bunch of cardiac muscle fibers is called tunneled artery or intramural artery. The band of cardiac muscle fibers passing over the tunneled artery segment is named as myocardial bridge. During angiography milking effect is observed during systole due to the external pressure of muscle fibers on the tunneled artery that leads to narrowing of vessel lumen and further isc...

  8. SURGERY OF SYMPTOMATIC MYOCARDIAL BRIDGING

    OpenAIRE

    N. Maghamipour N. Safaei

    2007-01-01

    Myocardial bridging with systolic compression of the left anterior descending coronary artery (LAD) may be associated with myocardial ischemia. In symptomatic myocardial bridging unresponsive to medical treatment, surgical unroofing of the left LAD can be performed. Little information is available about the long-term prognosis of patients with this coronary anomaly after the surgical unroofing, so we decided to evaluate the result of this operation. A total of 26 patients underwent surgical u...

  9. Stability of liquid crystalline bridges

    Science.gov (United States)

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

    1999-02-01

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

  10. SURGERY OF SYMPTOMATIC MYOCARDIAL BRIDGING

    Directory of Open Access Journals (Sweden)

    N. Maghamipour N. Safaei

    2007-06-01

    Full Text Available Myocardial bridging with systolic compression of the left anterior descending coronary artery (LAD may be associated with myocardial ischemia. In symptomatic myocardial bridging unresponsive to medical treatment, surgical unroofing of the left LAD can be performed. Little information is available about the long-term prognosis of patients with this coronary anomaly after the surgical unroofing, so we decided to evaluate the result of this operation. A total of 26 patients underwent surgical unroofing of myocardial bridging. Patients had a myocardial bridge of at least 3 cm in length in the middle of LAD and with more than 70% compression during systole. Unroofing was performed with cardiopulmonary bypass in 16 and with off pump technique in 10 patients. In 6 patients repeat angiographies for control of myotomy were done. In one of them a nonsignificant 20% narrowing was seen. Postoperative scintigraphic and angiographic studies demonstrated restoration of coronary flow and myocardial perfusion without residual myocardial bridges under beta-stimulation in 24 patients. Two patients had residual narrowing. With off pump technique, 1 patient had perforation of the right ventricle and 1 patient underwent reoperation because of incomplete unroofing during the first operation. None of the patients with cardiopulmonary bypass technique had residual chest pain or other complications. Surgical unroofing of myocardial bridging with the aid of cardiopulmonary bypass is a safe and easy procedure with low operative risk and with excellent functional results.

  11. Wave-current force on bridge foundation

    OpenAIRE

    Pan, J.N.; Wang, D.T.; Wang, X. G.; Nie, F

    2013-01-01

    Many cross-sea bridges have been constructed or in construction in the Chinese coastal areas, such as Hangzhou Bay Bridge, East China Sea Bridge and Hong Kong-Zhuhai-Macau Bridge, etc. Usually the foundations of cross-sea bridges will bear the load of wave and current simultaneously, the extreme value of which is an important factor for bridge design. It is quite difficult to estimate the extreme wave-current forces on bridge foundations due to their complex form, for example a polygonal plat...

  12. Risk assessment study on bridge foundation in deep overlying stratum

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiangqun; Wang Jingguo; Liu Manhong

    2012-01-01

    Based on the analysis about the hydrogeological conditions and engineering geological conditions, this paper makes analysis on the possible risks of the deep overlying stratum foundation and establishes the risk evaluation index system during the foundation operating period. Such methods as analytic hierarchy process (AHP) , Delphi method and fuzzy comprehensive evaluation method are adopted to make the quantitative analysis on the risk factors and establish the risk judgment model. According to the actual engineering of Taizhou Bridge, the paper evaluates the risk of the foundation during the operating period at the condition of deep overlying stratum. The evaluation results can provide the reference for the risk management of the bridge foundation durin~ the ooerating period.

  13. 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...

  14. Designing of support zones of concrete bridges to withstand action of static and dynamic load

    Directory of Open Access Journals (Sweden)

    Gligorijević Milan

    2010-01-01

    Full Text Available In the paper are presented some of the acquired experiences in designing and construction of bridge structures in several countries, with a special attention to the analysis of support zones and expansion joints behavior of a number of road bridges. During destruction or damage of bridges, there is a small probability, but still there, that the human lives might be endangered (Kobe, Japan 17th January 1995; what is likely, however, is that it will be very difficult to help the injured in the region. Considering that the characteristics of removal of supports has a great influence on the behavior of the entire bridge structure, the design of support joints and connections must be paid due attention. In the recent decades, efforts are made to enhance research of all engineering structure, and thus the bridge structures and their weak points.

  15. Catastrophic model for stability analysis of high pile-column bridge pier

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    According to the engineering features of higher pile-column bridge pier in mountainous area, a clamped beam mechanical model was set up by synthetically analyzing the higher pile-column bridge pier buckling mechanism. Based on the catastrophe theory, the cusp catastrophe model of higher pile-column bridge pier was established by the determination of its potential function and bifurcation set equation, the necessary instability conditions of high pile-column bridge pier were deduced, and the determination method for column-buckling and lateral displacement of high pile-column bridge pier was derived. The comparison between the experimental and calculated results show that the calculated curves agree with testing curves and the method is reasonable and effective.

  16. Road Performance of Fiber Reinforced Asphalt Concrete Bridge Deck Pavement

    OpenAIRE

    Xiu Liu; Zhaojie Sun; Decheng Feng; Yixiang Cao

    2013-01-01

    As the problem of asphalt concrete bridge deck pavement is becoming more and more serious, how to improve its road performance has become the focus of the study. Considering fiber is widely used in road engineering, wheel tracking test, flexural test, immersion marshall test and freeze-thaw splitting test were carried out to study road performance of asphalt mixture with different fiber contents, analyzing the function mechanism of fiber reinforced asphalt ...

  17. Deployment aspects of a tensegrity-ring pedestrian bridge

    OpenAIRE

    Rhode-Barbarigos, Landolf; Bel Hadj Ali, Nizar; Motro, René; Smith, Ian F.C.

    2011-01-01

    International audience Tensegrity structures are spatial systems that are composed of tension and compression components in a self-equilibrated prestress stable state. Although tensegrity systems were first introduced in 1950s, few examples have been used for civil engineering purposes. In this paper, tensegrity-ring modules are used for a deployable pedestrian bridge. Ring modules belong to a special family of tensegrity systems composed of a single strut circuit. Assembled in a "hollow-r...

  18. Fatigue lifetime estimation on the steel bridges with orthotropic decks

    Czech Academy of Sciences Publication Activity Database

    Culek jr., B.; Urushadze, Shota; Vágner, J.; Culek, B.; Frýba, Ladislav

    Siofók : Scientific Society for Mechanical Enginnering, 2011 - (Ódor, I.; Borbás, L.), s. 199-200 ISBN 978-963-9058-32-3. [Danubia- Adria Symposium SSME /28./. Siófok (HU), 28.09.2011-01.10.2011] Grant ostatní: GAČR(CZ) GA103/08/1340 Institutional research plan: CEZ:AV0Z20710524 Keywords : steel bridges * fatigue * orthotropic decks Subject RIV: JM - Building Engineering

  19. Dynamic characterization and damage detection in the I-40 bridge over the Rio Grande

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, C.R.; Baker, W.E.; Bell, T.M.; Cone, K.M.; Darling, T.W.; Duffey, T.A.; Eklund, A.; Migliori, A.

    1994-06-01

    In the 1960`s and 1970`s over 2500 bridges were built in the U.S. with a design similar to those on Interstate 40 over the Rio Grande in Albuquerque, New Mexico. These bridges were built without structural redundancy and typically have only two plate girders carrying the entire dead and live loads. Failure of either girder is assumed to produce catastrophic failure of the bridge, hence these bridges are referred to as fracture-critical bridges. The Federal Highway Administration (FHWA) and the National Science Foundation (NSF) have provided funds to New Mexico State University (NMSU) through the New Mexico State Highway and Transportation Department (NMSH&TD) and The Alliance For Transportation Research (ATR) for evaluation and testing of the existing fracture critical bridges over the Rio Grande. Because the 1-40 bridges over the Rio Grande were to be razed during the summer of 1993, the investigators were able to introduce simulated fatigue cracks, similar to those observed in the field, into the structure in order to test various damage identification methods and to observe the changes in load paths through the structure caused by the cracking. To support this research effort, NMSU contracted Los Alamos National Laboratory (LANL) to perform experimental modal analyses, and to develop experimentally verified numerical models of the bridge. Scientists from the LANL`s Condensed Matter and Thermal Physics Group (P-10) applied state-of-the-art sensors and data acquisition software to the modal tests. Engineers from the LANL`s Advanced Engineering Technology Group (MEE-13) conducted ambient and forced vibration tests to verify detailed and simplified finite element models of the bridge. Forced vibration testing was done in conjunction with engineers from Sandia National Laboratory (SNL) who provided and operated a hydraulic shaker.

  20. Bridging nations through muons

    CERN Multimedia

    2006-01-01

    From America to Israel and Japan, a team of international technicians and scientists are working together to build the ATLAS endcap muon chambers. The Israeli and Pakistani teams stand in front of part of the ATLAS endcap muon spectrometer. They are working on the project along with...... a team from American universities and research institutions. It's a small world; at least you might think so after a visit to Building 180. Inside, about 30 engineers and physicists weld, measure and hammer away, many of whom are miles from their homes and families. They hail from Pakistan, Israel, Japan, China, Russia and the United States. Coordinated by a group of CERN engineers, the team represents an international collaboration in every sense. Whether they've been here for years or months, CERN is their temporary home as they work toward one common goal: the completion of the ATLAS muon chamber endcaps. When finished, the ATLAS muon spectrometer will include four moving 'big wheel'structures on each end of the detecto...

  1. Encyclopedia of earthquake engineering

    CERN Document Server

    Kougioumtzoglou, Ioannis; Patelli, Edoardo; Au, Siu-Kui

    2015-01-01

    The Encyclopedia of Earthquake Engineering is designed to be the authoritative and comprehensive reference covering all major aspects of the science of earthquake engineering, specifically focusing on the interaction between earthquakes and infrastructure. The encyclopedia comprises approximately 265 contributions. Since earthquake engineering deals with the interaction between earthquake disturbances and the built infrastructure, the emphasis is on basic design processes important to both non-specialists and engineers so that readers become suitably well-informed without needing to deal with the details of specialist understanding. The content of this encyclopedia provides technically inclined and informed readers about the ways in which earthquakes can affect our infrastructure and how engineers would go about designing against, mitigating and remediating these effects. The coverage ranges from buildings, foundations, underground construction, lifelines and bridges, roads, embankments and slopes. The encycl...

  2. Fatigue and Fracture Library for the Inspection, Evaluation, and Repair of Vehicular Steel Bridges

    OpenAIRE

    Fish, Phil; Schroeder, Curtis; Connor, Robert J.; Sauser, Phil

    2015-01-01

    Of all the limit states that affect the performance of steel bridges, fatigue and fracture are often misunderstood when it comes to design, inspection, and repair/retrofit. Although there is a wealth of research and case studies of failures related to cracking in the literature, few civil engineering programs offer any courses that spend more than a lecture or two on these topics. There are even fewer courses or credible reference manuals available on the repair and retrofit of steel bridges ...

  3. Seismic Performance Analysis of Bridges with Isolation Devices Enhanced by Hybrid Dynamic Substructuring

    OpenAIRE

    Cazzador, Enrico

    2016-01-01

    The Seismic Performance Analysis of Bridges (SPAB) constitutes one of the biggest challenges for structural and civil engineers. In fact, the handling of these design problems requires a deep knowledge of structural behavior and a huge expertise with numerical and analytical tools necessary to perform advanced Finite Element (FE) simulations including dynamic and probabilistic aspects. Within the scope of SPAB, this thesis proposes the analysis of complex bridges assisted by the profitable we...

  4. 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.

  5. Modal Identification and Damage Detection on a Concrete Highway Bridge by Frequency Domain Decomposition

    DEFF Research Database (Denmark)

    Brincker, Rune; Andersen, Palle; Zhang, Lingmi

    2007-01-01

    As a part of a research project co-founded by the European Community, a series of 15 damage tests were performed on a prestressed concrete highway bridge in Switzerland. The ambient response of the bridge was recorded for each damage case. A dense array of instruments allowed the identification o...... objective is to show the application of the FDD method as an efficient way to perform health monitoring of civil engineering structures. The modal properties, frequencies, damping ratios and mode shapes for the different damage cases were compared with those for the undamaged bridge....

  6. Creep and shrinkage effects on integral abutment bridges

    Science.gov (United States)

    Munuswamy, Sivakumar

    Integral abutment bridges provide bridge engineers an economical design alternative to traditional bridges with expansion joints owing to the benefits, arising from elimination of expensive joints installation and reduced maintenance cost. The superstructure for integral abutment bridges is cast integrally with abutments. Time-dependent effects of creep, shrinkage of concrete, relaxation of prestressing steel, temperature gradient, restraints provided by abutment foundation and backfill and statical indeterminacy of the structure introduce time-dependent variations in the redundant forces. An analytical model and numerical procedure to predict instantaneous linear behavior and non-linear time dependent long-term behavior of continuous composite superstructure are developed in which the redundant forces in the integral abutment bridges are derived considering the time-dependent effects. The redistributions of moments due to time-dependent effects have been considered in the analysis. The analysis includes nonlinearity due to cracking of the concrete, as well as the time-dependent deformations. American Concrete Institute (ACI) and American Association of State Highway and Transportation Officials (AASHTO) models for creep and shrinkage are considered in modeling the time dependent material behavior. The variations in the material property of the cross-section corresponding to the constituent materials are incorporated and age-adjusted effective modulus method with relaxation procedure is followed to include the creep behavior of concrete. The partial restraint provided by the abutment-pile-soil system is modeled using discrete spring stiffness as translational and rotational degrees of freedom. Numerical simulation of the behavior is carried out on continuous composite integral abutment bridges and the deformations and stresses due to time-dependent effects due to typical sustained loads are computed. The results from the analytical model are compared with the

  7. Bridge Decomposition of Restriction Measures

    CERN Document Server

    Alberts, Tom

    2009-01-01

    Motivated by Kesten's bridge decomposition for two-dimensional self-avoiding walks in the upper half plane, we show that the conjectured scaling limit of the half-plane SAW, the SLE(8/3) process, also has an appropriately defined bridge decomposition. This continuum decomposition turns out to entirely be a consequence of the restriction property of SLE(8/3), and as a result can be generalized to the wider class of restriction measures. Specifically we show that the restriction hulls with index less than one can be decomposed into a Poisson Point Process of irreducible bridges in a way that is similar to Ito's excursion decomposition of a Brownian motion according to its zeros.

  8. Microscale technologies for cell engineering

    CERN Document Server

    Gaharwar, Akhilesh

    2016-01-01

    This book offers readers cutting-edge research at the interface of polymer science and engineering, biomedical engineering, materials science, and biology. State-of-the-art developments in microscale technologies for cell engineering applications are covered, including technologies relevant to both pluripotent and adult stem cells, the immune system, and somatic cells of the animal and human origin. This book bridges the gap in the understanding of engineering biology at multiple length scale, including microenvironmental control, bioprocessing, and tissue engineering in the areas of cardiac, cartilage, skeletal, and vascular tissues, among others. This book also discusses unique, emerging areas of micropatterning and three-dimensional printing models of cellular engineering, and contributes to the better understanding of the role of biophysical factors in determining the cell fate. Microscale Technologies for Cell Engineering is valuable for bioengineers, biomaterial scientists, tissue engineers, clinicians,...

  9. Seismic Analysis for Rigid-Framed Prestressed Reinforced Concrete Bridge in Tianjin Light Railway

    Institute of Scientific and Technical Information of China (English)

    丁阳; 李楠; 李忠献

    2004-01-01

    The seismic analysis of a rigid-framed prestressed concrete bridge in Tianjin Light Railway is performed. A 3-D dynamic finite element model of the bridge is established considering the weakening effect caused by the soft soil foundation. After the dynamic characteristics are calculated in terms of natural frequencies and modes, the seismic analysis is carried out using the modal response spectrum method and the time-history method, respectively. Based on the calculated results, the reasonable design values are finally suggested as the basis of the seismic design of the bridge, and meanwhile the problems encountered were also analyzed. Finally, some conclusions are drawn as: 1) Despite the superiority of rigid-framed prestressed concrete bridge, the upper and lower ends of the piers of the bridge are proved to be the crucial parts of the bridge, which are easily destroyed under designed earthquake excitations and should be carefully analyzed and designed; 2) The soft soil foundation can possibly result in rather weakening of the lateral rigidity of the rigid-framed bridge, and should be paid considerable attention; 3) The modal response spectrum method, combined with time-history method, is suggested for the seismic analysis in engineering design of the rigid-framed prestressed concrete bridge.

  10. Evaluation of Structural Behavior of Externally Prestressed Segmented Bridge with Shear Key under Torsion

    Directory of Open Access Journals (Sweden)

    M. A. Algorafi

    2011-07-01

    Full Text Available Externally Prestressed Segmented (EPS concrete beams are generally used in the construction of bridge structures. External Prestressed technique uses tendons that are placed completely outside the concrete section and attached to the concrete at anchorages and deviators only. Segmented bridge is a bridge built in short sections. Segmented bridge applies smart technique that is a part of an engineering management. EPS bridges are affected by combined stresses i.e., bending, shear, normal, and torsion stresses especially at the segments interface joints. Previous studies on EPS bridges did not include the effect of torsion in the load carrying capacity and other structural behavior. This paper presents an experimental investigation of the structural behavior of EPS bridged under combined bending, shear, normal, and torsion stresses. The aim of this paper is to improve the existing equation to include the effect of torsion in estimating the failure load of EPS bridge. A parametric study was carried out to investigate the effect of different external tendon layouts and different levels of torsion.

  11. Bridge Number and Conway Products

    OpenAIRE

    Blair, Ryan C.

    2007-01-01

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

  12. 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.

  13. An Expert System for Concrete Bridge Management

    DEFF Research Database (Denmark)

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

    1997-01-01

    The importance of bridge repair versus new bridge construction has risen in recent decades due to high deterioration rates that have been observed in these structures. Budgets both for building new bridges and keeping the existing ones are always limited. To help rational decision-making, bridge ...... information complemented by a knowledge-based interactive system, BRIDGE-1. To optimize management strategies at the headquarters, the BRIDGE-2 module was implemented, including three submodules: inspection strategy, maintenance and repair....... 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...

  14. 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.

  15. Artropathies that produce osseous bridges

    International Nuclear Information System (INIS)

    In this paper, it is reviewed the most common artropathies that are presented with osseous bridging, with emphasis in the radiological finding of the spine. Also, it's showed other different radiological finding that can help in the differential diagnosis of this disease, such us the sacroilitis in the ankylosing spondylitis or the osteolysis in the psoriatic arthritis

  16. Transition Slabs of Integral Abutment Bridges

    OpenAIRE

    Dreier, Damien; Muttoni, Aurelio; BURDET, Olivier

    2011-01-01

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

  17. Dynamic identification of paradela historic railway bridge

    OpenAIRE

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

    2013-01-01

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

  18. Path transformations of first passage bridges

    OpenAIRE

    Bertoin, Jean

    2003-01-01

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

  19. Thermodynamics an engineering approach

    CERN Document Server

    Cengel, Yunus A

    2014-01-01

    Thermodynamics, An Engineering Approach, eighth edition, covers the basic principles of thermodynamics while presenting a wealth of real-world engineering examples so students get a feel for how thermodynamics is applied in engineering practice. This text helps students develop an intuitive understanding by emphasizing the physics and physical arguments. Cengel and Boles explore the various facets of thermodynamics through careful explanations of concepts and use of numerous practical examples and figures, having students develop necessary skills to bridge the gap between knowledge and the confidence to properly apply their knowledge. McGraw-Hill is proud to offer Connect with the eighth edition of Cengel/Boles, Thermodynamics, An Engineering Approach. This innovative and powerful new system helps your students learn more efficiently and gives you the ability to assign homework problems simply and easily. Problems are graded automatically, and the results are recorded immediately. Track individual stude...

  20. 47 CFR 80.331 - Bridge-to-bridge communication procedure.

    Science.gov (United States)

    2010-10-01

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

  1. Bridge spectra of iterated torus knots

    OpenAIRE

    Zupan, Alexander

    2013-01-01

    We determine the set of all genus g bridge numbers of many iterated torus knots, listing these numbers in a sequence called the bridge spectrum. In addition, we prove a structural lemma about the decomposition of a strongly irreducible bridge surface induced by cutting along a collection of essential surfaces.

  2. Two bridges with composite prestressed tension chord

    OpenAIRE

    Muttoni, Aurelio

    2002-01-01

    the bridges over the river Capriasca (1996) and over the river Ticino (1997) are characterised by the application of an innovative structural system. The central part of the main span of both bridges is constituted by the bridge concrete deck with two longitudinal stiffening girders, constituted by polygonal steel members that contain two prestressing tendons each.

  3. Stabilizer for seismically exposed bridge cranes

    International Nuclear Information System (INIS)

    The invention concerns a stabilizer for seismically exposed bridge cranes in reactor buildings. The trolley and the crane bridge are fitted with the stabilizer consisting of a bipartite safety catch which is connected with a joint and able to take up the vertical loads during an earthquake. This stabilizer is suitable for all kinds of bridge cranes operated in seismically active regions

  4. Remediation: Higher Education's Bridge to Nowhere

    Science.gov (United States)

    Complete College America, 2012

    2012-01-01

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

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

    OpenAIRE

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

    2015-01-01

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

  6. Intelligent control for braking-induced longitudinal vibration responses of floating-type railway bridges

    International Nuclear Information System (INIS)

    This paper presents an intelligent control method and its engineering application in the control of braking-induced longitudinal vibration of floating-type railway bridges. Equations of motion for the controlled floating-type railway bridges have been established based on the analysis of the longitudinal vibration responses of floating-type railway bridges to train braking and axle-loads of moving trains. For engineering applications of the developed theory, a full-scale 500 kN smart magnetorheologic (MR) damper has been designed, fabricated and used to carry out experiments on the intelligent control of braking-induced longitudinal vibration. The procedure for using the developed intelligent method in conjunction with the full-scale 500 kN MR dampers has been proposed and used to control the longitudinal vibration responses of the deck of floating-type railway bridges induced by train braking and axle-loads of moving trains. This procedure has been applied to the longitudinal vibration control of the Tian Xingzhou highway and railway cable-stayed bridge over the Yangtze River in China. The simulated results have shown that the intelligent control system using the smart MR dampers can effectively control the longitudinal response of the floating-type railway bridge under excitations of braking and axle-loads of moving trains

  7. Analysis of local influences in structural details of the bridges

    Directory of Open Access Journals (Sweden)

    Adam RUDZIK

    2015-03-01

    Full Text Available The article analyses the problems of local influences in structural details of bridges as the critical locations, whose damages or excessive force may directly affect the safety of users. These analyses are shown on selected examples. Presented is the example of local changes in the forms of proper vibrations in the node of the truss bridge that can be used in expert issues concerning the causes of damages. The second example are the changes in stresses in the stay cable anchorage element including the nonlinear material models. Models of this type can be successfully used by engineers as they allow for analysis of selected structural details without the need for detailed mapping of the entire structure, but only a selected section.

  8. Theory of water and charged liquid bridges.

    Science.gov (United States)

    Morawetz, K

    2012-08-01

    The phenomenon of liquid bridge formation due to an applied electric field is investigated. A solution of a charged catenary is presented, which allows one to determine the static and dynamical stability conditions where charged liquid bridges are possible. The creeping height, the bridge radius and length, as well as the shape of the bridge are calculated showing an asymmetric profile, in agreement with observations. The flow profile is calculated from the Navier-Stokes equation leading to a mean velocity, which combines charge transport with neutral mass flow and which describes recent experiments on water bridges. PMID:23005849

  9. New Concept for Durable Concrete Bridges

    OpenAIRE

    Damek, Marek

    2015-01-01

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

  10. Field Application of Automated Power Arc Spraying System on Steel Bridge Deck

    Institute of Scientific and Technical Information of China (English)

    YI Chun-long; SUO Shuang-fu; SUN Zhi; PANG Xu-nan

    2004-01-01

    The effective corrosion protection coating and high productive coating equipment for steel bridge deck has been a challenge for bridge engineers for many years. An automated power arc spraying system was first designed and field applied to coating the deck of Wuhan Junshan Yangtze River Bridge in high efficiency. This steel bridge is a continuous orthotropic deck box girder cable-stayed bridge with 962 m in length and 38.8 m in width, whose width is the No. 1 in China. The whole orthotropic deck with over 35,000 m2surface area was arc-sprayed a protective coating of zinc on site, followed by a sealant and SMA paving material. The side face and bottom of box girders were arc-sprayed with aluminum in factory.Field application indicated that the newly designed automated power arc spraying system with fan nozzle and separate primary & secondary atomizing air had some advantages over the conventional arc spraying system, such as automated operation,big arc spray current, high spraying rate, big breadth of each coat, even and small atomized particles, high density and low porosity of sprayed coating, and high adhesive strength to the substrate.Working procedure of surface preparation and automated arc spraying on bridge deck were introduced, and the quality of sprayed coating is controlled strictly. Field tests proved that the application of this automated power arc spraying system is successful and suitable for coating the steel bridge deck.

  11. Noise Considerations in Resistance Bridges

    DEFF Research Database (Denmark)

    Diamond, Joseph M.

    1963-01-01

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

  12. Full-bridge capacitive extensometer

    Science.gov (United States)

    Peters, Randall D.

    1993-08-01

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

  13. 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...

  14. Investigations concerning seismic response control of self-anchored suspension bridge with MR dampers

    Institute of Scientific and Technical Information of China (English)

    Menggang YANG; Zhengqing CHEN; Jianhua HU

    2008-01-01

    To mitigate the seismic response of selfanchored suspension bridges, equations of motion governing the coupled system of bridge- magneto-rheological (MR) dampers subject to seismic excitation are formulated by employing the phenomenological model of MR dampers. A corresponding computer program is developed and employed for studying the seismic response control of a self-anchored suspension bridge with a main span of 350 m. The effect of variable current and number of dampers on seismic response control is investigated. The numerical results indicate the longitudinal displacement of the tower top and bridge girder decrease with the increase in input current and number of MR dampers attached longitudinally at the tower-girder connections, and the internal forces of the tower are effectively attenuated as well. It appears that small electronic current (0.5 A in this study) may sufficiently attenuate the seismic responses for practical engineering applications.

  15. 2015 Bridge Inspection ERC Training

    OpenAIRE

    Dougherty, Merril

    2015-01-01

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

  16. 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 tests...... 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....

  17. Stability of Axisymmetric Liquid Bridges

    CERN Document Server

    Rubinstein, Boris

    2016-01-01

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

  18. The Bridge Program - Participant Perspectives

    OpenAIRE

    Rönnqvist, Riitta; Hakonen, Anu; Vartiainen, Matti

    2015-01-01

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

  19. Inspection Strategies for Concrete Bridges

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    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....

  20. Adsorption of polymeric brushes: Bridging

    Science.gov (United States)

    Johner, Albert; Joanny, Jean-François

    1992-04-01

    We study the adsorption of grafted polymer layers on a planar surface parallel to the grafting surface. The layer consists of two types of chains: nonadsorbed chains with a free end and adsorbed chains forming bridges between the two plates. In the limit of strong adsorption a dead zone exists in the vicinity of the adsorbing plate; its size increases with the adsorption strength. Two adsorption mechanisms are possible: adsorption of the last monomer only and adsorption of all the monomers. In both cases the adsorption regimes at equilibrium (when no external force acts on the plates) are discussed within the framework of the self-consistent mean-field theory. We also give scaling laws taking into account excluded volume correlations. Finally, we consider situations where a finite external force, either tangential or normal to the plates, is applied on the adsorbing plate. Pulling and tangential forces both reduce the fraction of bridges and eventually lead to rupture, whereas compressional forces favor bridging. For normal forces, force vs distance profiles between planes and crossed cylinders are given.

  1. Halliburton Composite Bridge Plug Assembly

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-01-15

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

  2. Development of the applicability of simplified Henry's method for skewed multicell box-girder bridges under traffic loading conditions

    Institute of Scientific and Technical Information of China (English)

    Iman MOHSENI; A.R.Khalim RASHID

    2012-01-01

    Concrete precast multicell box-girder (MCB) bridges combine aesthetics with torsional stiffness perfectly.Previous analytical studies indicate that currently available specifications are unable to consider the effect of the twisting moment (torsional moment) on bridge actions.In straight bridges the effect of torsion is negligible and the transverse reinforced design is governed by other requirements.However,in the case of skewed bridges the effect of the twisting moment should be considered.Therefore,an in-depth study was performed on 90 concrete MCB bridges with skew angles ranging from 0° to 60°.For each girder the bridge actions were determined under the American Association of State Highway and Transportation Officials (AASHTO) live load conditions.The analytical results show that torsional stiffness and live load positions greatly affected the bridges' responses.In addition,based on a statistical analysis of the obtained results,several skew correction factors are proposed to improve the precision of the simplified Henry's method,which is widely used by bridge engineers to predict bridge actions.The relationship between the bending moment and secondary moments was also investigated and it was concluded that all secondary actions increase with an increase in skewness.

  3. Interaction dynamics of a high-speed train moving on multi-span railway bridges with support settlements

    Czech Academy of Sciences Publication Activity Database

    Yau, J. D.; Frýba, Ladislav

    Leuven: Katholieke University Leuven, 2014 - (Sas, P.; Moens, D.; Denayer, H.), s. 955-963 ISBN 978-90-73802-91-9. [International Conference on Noise and Vibration Engineering (ISMA). Leuven (BE), 15.09.2014-17.09.2014] Institutional support: RVO:68378297 Keywords : loads * beams * railway bridge Subject RIV: JM - Building Engineering http://www.isma-isaac.be/publications/proceedings.html

  4. Coordination and communication inside game engine

    OpenAIRE

    Kukkamaa, T. (Tuomas)

    2015-01-01

    This study examines the communication and coordination among different parts of game engine. As games contain multiple co-operating processes, each of which handles a small part of whole game experience, game engines must handle the management of co-operation efficiently. The issue is that while the competitive and demanding game industry has hastened the development of game engines, the academic research has been lagging behind. This study aims to bridge the gap between industrial know-h...

  5. Study on the Safety of the Rock Mass in the Tongling Bank of Taipinghu Bridge

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    The Taipinghu Bridge is an important engineering construction, and the safety of rock mass of its foundation is very crucial. This article adopts FLAC 3D to analysis the geologic model. The simulating process shows that no mater the excavating process or the loading process the rock mass are safe. The modeling and analyzing process can be used for reference.

  6. Research and Teaching: Association of Summer Bridge Program Outcomes with STEM Retention of Targeted Demographic Groups

    Science.gov (United States)

    Tomasko, David L.; Ridgway, Judith S.; Waller, Rocquel J.; Olesik, Susan V.

    2016-01-01

    Retention of students to science, technology, engineering, and mathematics (STEM) major has been studied for four cohorts participating in a summer bridge program supported by the National Science Foundation. Students participated in a 6-week program prior to their first term of enrollment at a research-intensive land grant university. Comparisons…

  7. Simulation Study on Train-Induced Vibration Control of a Long-Span Steel Truss Girder Bridge by Tuned Mass Dampers

    OpenAIRE

    2014-01-01

    Train-induced vibration of steel truss bridges is one of the key issues in bridge engineering. This paper talks about the application of tuned mass damper (TMD) on the vibration control of a steel truss bridge subjected to dynamic train loads. The Nanjing Yangtze River Bridge (NYRB) is taken as the research object and a recorded typical train load is included in this study. With dynamic finite element (FE) method, the real-time dynamic responses of NYRB are analyzed based on a simplified trai...

  8. 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

  9. 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

  10. Seismic Evaluation of Highway Bridges - Phase 1

    OpenAIRE

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

    1996-01-01

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

  11. REPORT: BioMedBridges standards workshop

    OpenAIRE

    Conte, Nathalie; Hancocks, Tom; Suhr, Stephanie

    2014-01-01

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

  12. Bridges and wildlife: issues and solutions

    OpenAIRE

    Carey, Marion

    2003-01-01

    The Washington State Department of Transportation (WSDOT) owns over 3,000 steel and concrete bridges, many of which are occupied by wildlife. Species documented occupying bridges range from birds of prey, such as ospreys, peregrines and owls, to mammals such as raccoons, bats and bushy tailed wood rats. While the bridges are playing an important role in providing habitat for wildlife, their presence can also lead to costly project delays. Project Objective The project objective is to develop ...

  13. Markovian Bridges: Weak continuity and pathwise constructions

    OpenAIRE

    Chaumont, Loïc; Uribe Bravo, Gerónimo

    2009-01-01

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

  14. Maximal liquid bridges between horizontal cylinders

    OpenAIRE

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

    2016-01-01

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

  15. Life Cycle Assessment of a Norwegian Bridge

    OpenAIRE

    Dequidt, Thomas Charles Edouard

    2012-01-01

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

  16. Measurement of Deflection Line on Bridges

    Science.gov (United States)

    Urban, Rudolf; Štroner, Martin

    2013-12-01

    Prestressed concrete bridges are very sensitive to the increase in long-term deflections. Reliable forecasts of deflections of bridge structures during construction and durability are crucial for achieving good durability. The main results of measurements are the changes of the deflection line of the bridge structures, which places special demands on the measurement procedure. Results from measurements are very useful for the improvement of mathematical prediction methods of behaviour of long span prestressed concrete structures.

  17. Axisymmetric long liquid bridges stability and resonances

    OpenAIRE

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

    1990-01-01

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

  18. Study on the Safety of the Foundation Rock Masses in the Tangkou Bank of the Taipinghu Bridge

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    The Taipinghu Bridge is an important project, and the safety of rock masses of its foundation is very crucial. This article analyzes the potential causes of the deformation of the rock masses of the bridge foundation, and uses the Fast Lagrangian Analysis of Continua to analyze the geologic model. The simulating process shows that no mater in the excavating process or in the loading process the rock masses are suit for the engineering. The modeling and analyzing process can be used for reference.

  19. The Behaviour of the Embedded Rail in Interaction with Bridges

    Science.gov (United States)

    Ryjáček, P.; Howlader, Md M.; Vokáč, M.

    2015-11-01

    Since the introduction of the direct fastening system, Embedded Rail System (ERS) is probably one of the most spectacular and innovative developments in railway engineering. The development has become more rapid, especially in the last decade due to competitive advantages in comparison toother systems with respect to higher speed, cost effectiveness, environmental-material sustainability and others. But still there is a lack of specific interaction model, especially when it comes to bridges equipped with ERS system. Previous studies on ERS by Estzer Ludvigh2 found out some important coefficients (vertical and longitudinal bedding coefficient) and compared the longitudinal resistance of ERS with flexible fastening systems. Other studies on ERS do not specifically deal with the evaluation of longitudinal resistance of such a system. With a view to establish the typical behaviour pattern of ERS, this paper is dedicated to find out the interaction of a specific Embedded Rail System with bridges. A small scale test was conducted on a sample of ERS in the laboratory under different combinations of vertical and longitudinal track loads and subsequently a Finite Element Model (FEM) was developed to simulate the test. The paper presents the FEA result validation with test results, the interaction pattern, longitudinal resistance of ERS track for both loaded and unloaded conditions, design load distribution for such systems and some specific influences of ERS on simply supported bridge systems.

  20. Myocardial bridges: morphological and functional aspects.

    OpenAIRE

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

    1991-01-01

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

  1. 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.

  2. Risk assessment of strait crossing bridges

    OpenAIRE

    Forsnes, Mari Krogness

    2015-01-01

    The purpose of this thesis is to try to provide an overall risk picture for the planned strait cross- ing (SC) bridges on coastal highway E39 between Trondheim and Kristiansand in Norway. The thesis starts off by explaining the concepts and solutions of SC bridges to understand what the National Public Road Administration (NPRA) is planning to accomplish with the coastal high- way E39. The SC bridges cannot be compared to any other bridge structures in the world, which will lead to some chall...

  3. Welding engineering manual for constructing engineers. Pt. 2

    International Nuclear Information System (INIS)

    The manual is a real treasure trove of knowledge and experience for the statics expert, the constructing engineer, and the welding engineer, who have to do with design and dimensioning of welding engineering work for steel structures, bridges, boilers, vessels, and pipes. Many practical examples are given together with numerous data that provide helpful information for the task of technical and economic design and dimensioning. Determination of efficient and appropriate cross-sectional dimensions and materials is the main goal of the manual. Structural steel engineering and installations subject to monitoring and inspection such as boilers, pipings, pressure vessels, and nuclear installations are the subject fields dealt with in separate chapters. The dimensioning rules presented are based on the regulations and technical codes valid in the GDR and the FRG. The catalogue of technical rules of the FRG concerning structural steel engineering and installations as above are given in supplementary chapters. (orig./HP)

  4. 33 CFR 118.140 - Painting bridge piers.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Painting bridge piers. 118.140 Section 118.140 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.140 Painting bridge piers. The District Commander may require painting the sides of bridge channel piers...

  5. 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...

  6. 49 CFR 237.101 - Scheduling of bridge inspections.

    Science.gov (United States)

    2010-10-01

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

  7. 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...

  8. Dynamic and Fatigue Analysis of an 18th Century Steel Arch Bridge

    International Nuclear Information System (INIS)

    Within the 'Oran-Tlemcen' railway line realization project (159 km), several bridges were built by the Railroads Algerian West Company. 7 km from the east of Tlemcen city, this railway line must cross a very broken mountainous collar, that's why the French engineer 'Gustave Eiffel' was solicited to construct a 68 m length bridge. In 1890, an arch steel truss bridge was realized. The bridge presents 300 m of apron curvature radius and, currently, is considered as one of the most important monuments of the Algerian historical heritage. Considering the age of the bridge and the evolution of the railway loads in time, it was essential to check the good behavior of the studied structure. For that, analyses to verify the physical and mechanical properties of the growth iron members are made. A finite element model of the bridge was built and numerical simulations were drawn. The structural vibration conducted analysis permit to understand the behavior of this particular structure, then to evaluate (in detail) the rate of the structure fatigue

  9. Development of a wireless strain node and the software to monitor fracture-critical bridges

    Science.gov (United States)

    Fasl, Jeremiah; Samaras, Vasileios; Reichenbach, Matt; Helwig, Todd; Wood, Sharon L.; Potter, David; Lindenberg, Richard; Frank, Karl

    2012-04-01

    Real-time, monitoring systems can enhance the bridge inspection process by providing data for estimating the health of the bridge and potentially notifying bridge owners of problems between inspection visits. A low-power, wireless, strain data acquisition device has recently been developed to acquire dynamic strain data. Strain gages can be used to monitor the number and size of stress cycles in fatigue-sensitive members. From the cycle count, Palmgren-Miner's rule can be used to determine an effective stress range. The remaining fatigue life can then be calculated and compared to existing conditions and the age of the bridge. Because damage is expected to escalate over time, more frequent inspections may be needed when a bridge approaches its fatigue life. The strain node can be programmed in LabVIEW WSN to detect critical events or perform a rainflow analysis. To aid in system interaction, a software interface will be designed to allow for automated processing and transmission of data to a cloud server, thereby allowing engineers and bridge owners to access the data from anywhere so as to make informed decisions when prioritizing inspections. This paper will present the development of the strain node and the software interface.

  10. 淦河桥梁方案设计研究%Design and Research on Bridge Scheme of Gan River

    Institute of Scientific and Technical Information of China (English)

    蔡忠华

    2016-01-01

    Following the principal of applicable,economical,safe and beautiful and taking the bridge crossing Gan River in Jingui west road in Xianning City as the engineering background,four types of bridge design schemes are introduced,namely simple supported girder bridge,continuous girder bridge,through tied-arch bridge,and cable-stayed bridge without backstays.The tied arch bridge is chosen as the recommended proposal by taking bridge design,landscape feature,construction feasibil-ity and economy into comprehensive consideration.%遵循“适用、经济、安全、美观”的桥梁设计基本原则,以咸宁市金桂西路跨淦河大桥为工程背景,提供了4种桥梁设计方案:无背索斜拉桥,预应力混凝土连续梁桥、预应力混凝土简支 T梁桥、下承式系杆拱桥。综合考虑论证桥梁构造设计、景观特色、施工可行性和经济性等因素,选取下承式系杆拱桥作为推荐方案。

  11. A bridge between conceptual frameworks sciences, society and technology studies

    CERN Document Server

    2015-01-01

    This book analyzes scientific problems within the history of physics, engineering, chemistry, astronomy and medicine, correlated with technological applications in the social context. When and how is tension between disciplines explicitly practised? What is the conceptual bridge between science researches and the organization of technological researches in the development of  industrial applications?  The authors explain various ways in which the sciences allowed advanced modelling on the one hand, and the development of new technological ideas on the other hand. An emphasis on the role played by mechanisms, production methods and instruments bestows a benefit on historical and scientific discourse: theories, institutions, universities, schools for engineers, social implications as well.  Scholars from different traditions discuss the emerging style of thinking in methodology and, in theoretical perspective, aim to gather and re-evaluate the current thinking on this subject. It brings together contribution...

  12. A Cloverleaf of Software Engineering

    DEFF Research Database (Denmark)

    Bjørner, Dines

    2005-01-01

    We shall touch upon four issues of software engineering (SE): domain engineering, formal techniques, SE sociology, and academic software architects. First, before software can be designed one must understand its requirements; but before requirements can be formulated one must understand the domain......, however "lite". Third, despite 35 years of formal methods, the SE industry, maturity-wise still lags far behind that of other engineering disciplines. So we examine why. Finally, in several areas, in health care, in architecture, and others, we see that major undertakings are primarily spearheaded...... by senior academic staff. Professors of medicine daily perform specialized surgery and treatments at hospitals. Professors of architecture design new, daring buildings for industry, and professors of civil engineering head the engineering structural design of new, daring bridges. So we speculate what...

  13. Static and fatigue investigation of second generation steel free bridge decks

    International Nuclear Information System (INIS)

    This paper outlines the static and fatigue behavior of two different cast-in-place second generation steel-free bridge decks, which are: hybrid carbon fiber reinforced polymer (CFRP); and glass fiber reinforced polymer (GFRP) and steel strap design. Although cast monolithically, the first deck slab was divided into three segments with different reinforcement configurations. All three segments were tested under a 222kN cyclic loading to investigate fatigue behavior. The second bridge deck comprised an internal panel and two cantilevers and was equipped with a civionics system. The internal panel static test that this paper deals with is useful in the development of fatigue theory derived from fatigue testing of the first bridge deck. Test results form the cyclic loading of the first bridge deck indicated that the cross-sectional area of the reinforcement used in the test bridge deck can be reduced by 40% based on the reinforcement provided in the deck under service loads. The hybrid system also reduced the development of longitudinal crack widths to approximately 0.4 mm under service conditions, compared to the cracks that occurred approximately halfway between adjacent bridge girders that were determined to be roughly 1 mm in several first generation steel-free bridge decks constructed in Canada. Civionics, also discussed in the paper, is a new term coined from Civil-Electronics, which is the application of electronics to civil structures. The Civionics Specifications (2004) developed by ISIS Canada researchers are a helpful design tool for engineers and contractors to develop civionics and structural health monitoring systems for civil infrastructure that will last the lifetime of a structure. The use of civionics for the second test bridge deck ensured the survival of 100% of the 63 internal sensors throughout the rigors of the construction and casting of the deck. (author)

  14. MATHEMATICAL MODELLING OF THE BRIDGES STRUCTURAL MONITORING I

    Directory of Open Access Journals (Sweden)

    Rădulescu G.M.T.

    2015-05-01

    Full Text Available Structural Health Monitoring is an extremely complex and relatively expensive activity, and the current offer of tools, methods and technologies is varied, which can lead to a virtually high number of structural monitoring systems that can be customized for each case. In time, the monitoring of bridges became the engine for the development of SHM tools, methods and technologies, or manager monitoring systems. The case study, in continuous quasi-static condition, was performed on Incheon Grand Bridge South Korea. Tracking the behaviour of an objective under the influence of sunshine is performed by VCE Vienna Consulting Engineers ZT GmbH. This paper presents the effect of sunshine on a steel structural element, the first lamella front North line, by comparing data pairs that reflect the cause: steel temperature and the effect: the movement of a sensor mounted on the structural element. The analysis was performed using several software dedicated to mathematical modelling, trying to establish different mathematical models that can be tested and validated.

  15. Bridge weigh-in-motion on steel orthotropic decks and application to bridge assessment

    OpenAIRE

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

    2012-01-01

    Bridge weigh-in-motion uses an instrumented bridge as a scale to weigh vehicles. Several types of bridges may be used, if being sensitive to wheel or axle loads. Here some strains of steel orthotropic deck bridges are measured by extensometers and analyzed by software, to calculate axle loads and gross vehicle weights. Between 2009 and 2011, several large scale tests were done on the Millau viaduct (France), the tallest cable stayed bridge in the world. These tests showed that the system meet...

  16. Bridge Lock-up Device System

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

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

  17. Analysis of Biaxially Stressed Bridge Deck Plates

    DEFF Research Database (Denmark)

    Jönsson, Jeppe; Bondum, Tommi Højer

    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 ...

  18. 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 of...

  19. Paul Dirac:. Building Bridges of the Mind

    Science.gov (United States)

    Brown, Laurie M.

    2003-12-01

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

  20. Fast response Full Bridge Power Factor Corrector

    OpenAIRE

    Chan, CH; Pong, MH

    1998-01-01

    A fast response Full Bridge Power Factor Corrector (FBPFC) is presented in this paper. The converter is combined by two interleaved boost cells and a conventional full bridge converter. As the interleaving technique is applied, the input ripple current of FBPFC are reduced. Experimental result shows that the maximum power factor is 0.98 even without input filter.

  1. A STUDY OF BARRIERS IN BRIDGING COMMUNICATION

    OpenAIRE

    Niteen V. Dandekar

    2014-01-01

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

  2. 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...

  3. 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.

  4. History of cable-stayed bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

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

  5. 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.

  6. Study on complexity of Sutong Bridge's objectives system and its meta-synthesis management

    Institute of Scientific and Technical Information of China (English)

    Fa Yueping; Li Zhen

    2009-01-01

    Objectives define the boundaries of complex engineering system. It is a hard work to identify the specific objectives of a complex engineering system. The objectives system development needs a complicated process, from nix to prototype, and to final definition. The total process will cover the following course: from chaos to well-ordered; from qualitativeness to combination of quantitativeness and qualitativenss, then from qualitativeness to quantitativeness (a recurrent process), expert experience and theoretical science, rationality and sensibility, synthesis analysis and meta-synthesis, routinization and non-routinization. Such process is explicit in phase development yet overlapped; mutually confined yet mutuaLly independent; permeated conflicts yet pregnant in harmony. This article explores the complexity of Sutong Bridge's objectives development and the process of meta-synthesis in the Sutong Bridge engineering.

  7. Structural Performance of Light Weight Multicellular FRP Composite Bridge Deck Using Finite Element Analysis

    Institute of Scientific and Technical Information of China (English)

    Woraphot Prachasaree; Pongsak Sookmanee

    2012-01-01

    Fiber reinforced polymer (FRP) composite materials having advantages such as higher strength to weight than conventional engineering materials,non-corrosiveness and modularization,which should help engineers to obtain more efficient and cost effective structural materials and systems.Currently,FRP composites are becoming more popular in civil engineering applications.The objectives of this research are to study performance and behavior of light weight multi-cellular FRP composite bridge decks (both module and system levels) under various loading conditions through finite element modeling,and to validate analytical response of FRP composite bridge decks with data from laboratory evaluations.The relative deflection,equivalent flexural rigidity,failure load (mode) and load distribution factors (LDF) based on FE results have been compared with experimental data and discussed in detail.The finite element results showing good correlations with experimental data are presented in this work.

  8. WAVE CURRENT FORCES ON THE PILE GROUP OF BASE FOUNDATION FOR THE EAST SEA BRIDGE, CHINA

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    On the basis of the two structures of the bridge foundation designed for the East Sea Bridge, the wave current forces on four types of oblique piles, the pile group and the single piles at different positions in the pile group considering the effect of the super structures were experimentally investigated. The relationship between the wave current forces and the associated wave parameters, and the comparison of the wave current forces on the pile groups and the single piles were systematically analyzed. The group effectiveness and the reduction coefficient for the wave current forces on the group were examined for engineering design.

  9. Dynamic Interactions of a Train Moving Over a Rail Suspension Bridge with Multiple Support Settlements

    Czech Academy of Sciences Publication Activity Database

    Yau, Y. D.; Frýba, Ladislav

    Liberec: Technical University of Liberec, 2011 - (Segĺa, Š.; Tůma, J.; Petríková, I.; Pešek, L.), s. 235-240 ISBN 978-80-7372-759-8. [International Conference on Vibrational Problems 2011. Praha (CZ), 05.09.2011-08.09.2011] Grant ostatní: National Science Council of Taiwan(TW) NSC 97-2221-E-032-022-MY2 Institutional research plan: CEZ:AV0Z20710524 Keywords : high speed train * ground settlement * suspension bridge * vehicle/bridge interactions Subject RIV: JM - Building Engineering

  10. Optimum Maintenance Strategies for Highway Bridges

    DEFF Research Database (Denmark)

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

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

  11. Modeling walker synchronization on the Millennium Bridge

    Science.gov (United States)

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

    2007-02-01

    On its opening day the London Millennium footbridge experienced unexpected large amplitude wobbling subsequent to the migration of pedestrians onto the bridge. Modeling the stepping of the pedestrians on the bridge as phase oscillators, we obtain a model for the combined dynamics of people and the bridge that is analytically tractable. It provides predictions for the phase dynamics of individual walkers and for the critical number of people for the onset of oscillations. Numerical simulations and analytical estimates reproduce the linear relation between pedestrian force and bridge velocity as observed in experiments. They allow prediction of the amplitude of bridge motion, the rate of relaxation to the synchronized state and the magnitude of the fluctuations due to a finite number of people.

  12. 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 �...

  13. Flutter derivatives of the Kao-Pin Hsi cable-supported bridge

    Czech Academy of Sciences Publication Activity Database

    Buljac, A.; Pospíšil, Stanislav; Kozmar, H.; Kuznetsov, Sergeii; Král, Radomil

    Vol. 821. Zürich: Trans Tech Publications Inc, 2016 - (Fischer, C.), s. 172-179. (Engineering Mechanics. 821). ISBN 978-3-03835-700-1. ISSN 1660-9336. [Engineering mechanics 2015 /21./. Svratka (CZ), 11.05.2015-14.05.2015] R&D Projects: GA ČR(CZ) GA15-01035S; GA MŠk(CZ) LO1219 Institutional support: RVO:68378297 Keywords : bridge-deck section * vibrations * aeroelasticity * flutter derivatives * wind-tunnel experiments Subject RIV: JM - Building Engineering

  14. Modified Geometry of Transition Slabs for Integral Bridges

    OpenAIRE

    Dreier, Damien

    2010-01-01

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

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

    OpenAIRE

    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 have shown that the bonding strength of membrane layers to the surrounding materials has a strong influence on the structural response of orthotropic steel bridge decks. The most important requireme...

  16. Engineer Ethics

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dae Sik; Kim, Yeong Pil; Kim, Yeong Jin

    2003-03-15

    This book tells of engineer ethics such as basic understanding of engineer ethics with history of engineering as a occupation, definition of engineering and specialized job and engineering, engineer ethics as professional ethics, general principles of ethics and its limitation, ethical theory and application, technique to solve the ethical problems, responsibility, safety and danger, information engineer ethics, biotechnological ethics like artificial insemination, life reproduction, gene therapy and environmental ethics.

  17. Engineer Ethics

    International Nuclear Information System (INIS)

    This book tells of engineer ethics such as basic understanding of engineer ethics with history of engineering as a occupation, definition of engineering and specialized job and engineering, engineer ethics as professional ethics, general principles of ethics and its limitation, ethical theory and application, technique to solve the ethical problems, responsibility, safety and danger, information engineer ethics, biotechnological ethics like artificial insemination, life reproduction, gene therapy and environmental ethics.

  18. A framework for rapid post-earthquake assessment of bridges and restoration of transportation network functionality using structural health monitoring

    Science.gov (United States)

    Omenzetter, Piotr; Ramhormozian, Shahab; Mangabhai, Poonam; Singh, Ravikash; Orense, Rolando

    2013-04-01

    Quick and reliable assessment of the condition of bridges in a transportation network after an earthquake can greatly assist immediate post-disaster response and long-term recovery. However, experience shows that available resources, such as qualified inspectors and engineers, will typically be stretched for such tasks. Structural health monitoring (SHM) systems can therefore make a real difference in this context. SHM, however, needs to be deployed in a strategic manner and integrated into the overall disaster response plans and actions to maximize its benefits. This study presents, in its first part, a framework of how this can be achieved. Since it will not be feasible, or indeed necessary, to use SHM on every bridge, it is necessary to prioritize bridges within individual networks for SHM deployment. A methodology for such prioritization based on structural and geotechnical seismic risks affecting bridges and their importance within a network is proposed in the second part. An example using the methodology application to selected bridges in the medium-sized transportation network of Wellington, New Zealand is provided. The third part of the paper is concerned with using monitoring data for quick assessment of bridge condition and damage after an earthquake. Depending on the bridge risk profile, it is envisaged that data will be obtained from either local or national seismic monitoring arrays or SHM systems installed on bridges. A method using artificial neural networks is proposed for using data from a seismic array to infer key ground motion parameters at an arbitrary bridges site. The methodology is applied to seismic data collected in Christchurch, New Zealand. Finally, how such ground motion parameters can be used in bridge damage and condition assessment is outlined.

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

    Directory of Open Access Journals (Sweden)

    Rong Chen

    2013-01-01

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

  20. 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.

  1. Evaluation of the Structure Stability of a Plate Girder Bridge Using MIDAS Structure Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eui Soo; Kim, Jong Hyuk [National Forensic Service, Wonju (Korea, Republic of)

    2014-04-15

    Recently, as a means of resolving the issue of legal liability in the event of an accident or a disaster, a wide variety of simulation techniques, such as structural and structure-fluid interaction analysis, have been used in the field of forensic engineering. The plate girder bridge discussed in this paper was being constructed between a pier and an abutment to expand an existing bridge, but an accident whereby the bridge overturned occurred at the end of the concrete laying process for a protective wall. This accident was caused by additional loads not being considered at the time of the design as well as the actual construction being different from the design. The additional loads ultimately generated a negative support force. In this study, we determined the cause of the accident by comparing the structural stability of the original design with that of the additional, non-conforming construction using MIDAS structural analysis.

  2. Knowledge-Based Systems for the Assessment and Management of Bridge Structures

    DEFF Research Database (Denmark)

    Miyamoto, A.; Thoft-Christensen, Palle; Yan, B.

    2004-01-01

    aim of this paper is to summarize the finding of up-to-date research articles concerning the application of knowledge-based systems to assessment and management of structures and to illustrate the potential of such systems in the structural engineering. Two modern bridge management systems (BMS's) are......It is becoming an important social problem to make maintenance and rehabilitation of existing infrastructures such as bridges, buildings, etc. The kernel of such structure management is to develop a method of safety assessment on items which include remaining life and load carrying capacity. The...... presented in the paper. The first is a BMS to assess the performance and derive optimal strategies for inspection and maintenance of concrete structures using reliability based and knowledge based systems. The second is the concrete bridge rating expert system (BREX) to evaluate the performance of existing...

  3. Vibration monitoring of long bridges and their expansion joints and seismic devices

    Directory of Open Access Journals (Sweden)

    Islami Kleidi

    2015-01-01

    Full Text Available This paper presents a number of recently installed Structural Health Monitoring (SHM systems: a on a 2km double suspension bridge; b on a long railway viaduct that has experienced cracking; and c on a steel arch bridge in a seismically active area. Damage detection techniques have been applied based on high-frequency measurements of vibrations, pressure and strain, enabling a proper understanding of the structures’ behaviour to be gained. The diverse range of applications presented, designed in collaboration with structure owners and design engineers, includes damage detection on expansion joints of suspension bridges, crack analysis and correlation with accelerations of high-speed trains, and high-frequency performance monitoring of seismic devices. These case studies, based on both static and dynamic approaches, demonstrate the usefulness and ease of use of such systems, and the enormous gains in efficiency they offer.

  4. Multi-objective optimization design of bridge piers with hybrid heuristic algorithms

    Institute of Scientific and Technical Information of China (English)

    Francisco J. MARTINEZ-MARTIN; Femando GONZALEZ-VIDOSA; Antonio HOSPITALER; Victor YEPES

    2012-01-01

    This paper describes one approach to the design of reinforced concrete (RC) bridge piers,using a three-hybrid multiobjective simulated annealing (SA) algorithm with a neighborhood move based on the mutation operator from the genetic algorithms (GAs),namely MOSAMO1,MOSAMO2 and MOSAMO3.The procedure is applied to three objective functions:the economic cost,the reinforcing steel congestion and the embedded CO2 emissions.Additional results for a random walk and a descent local search multi-objective algorithm are presented.The evaluation of solutions follows the Spanish Code for structural concrete.The methodology was applied to a typical bridge pier of 23,97 m in height.This example involved 110 design variables.Results indicate that algorithm MOSAMO2 outperforms other algorithms regarding the definition of Pareto fronts.Further,the proposed procedure will help structural engineers to enhance their bridge pier designs.

  5. 20 Engineering Technologies Which Changed The World

    Energy Technology Data Exchange (ETDEWEB)

    Lee, In Sik; Shin, Dong Won; Mun, Jung Yang and others

    2004-07-15

    This book deals with 20 engineering technologies which changed the world, these are about a, compass, papermaking, a lens, gunpowder, machine watch, printing technique, vaccine, a suspension bridge, a railroad, a loom, photograph, petroleum, automobile, electricity, wireless communications, synthetic medicine, a jet engine and a rocket, nuclear bombs, ENIAC, and polymerase chain reaction method. Each skill is introduced with history and the detailed reports by other persons.

  6. Characterization of material for civil engineering

    OpenAIRE

    Cappelletto, Elisa

    2014-01-01

    Materials are the heart of engineering, which can be defined as the creative and rational use of materials for practical purposes. Materials have had an essential role in the development of civil engineering: from the beginning of human evolution, man has used many different materials to build houses, bridges, roads and countless other structures to make his life easier. Ancient populations used the raw materials at their disposal, such as stone, clay and timber. Over the centuries, the searc...

  7. 20 Engineering Technologies Which Changed The World

    International Nuclear Information System (INIS)

    This book deals with 20 engineering technologies which changed the world, these are about a, compass, papermaking, a lens, gunpowder, machine watch, printing technique, vaccine, a suspension bridge, a railroad, a loom, photograph, petroleum, automobile, electricity, wireless communications, synthetic medicine, a jet engine and a rocket, nuclear bombs, ENIAC, and polymerase chain reaction method. Each skill is introduced with history and the detailed reports by other persons.

  8. Partially entangled states bridge in quantum teleportation

    Science.gov (United States)

    Cai, Xiao-Fei; Yu, Xu-Tao; Shi, Li-Hui; Zhang, Zai-Chen

    2014-10-01

    The traditional method for information transfer in a quantum communication system using partially entangled state resource is quantum distillation or direct teleportation. In order to reduce the waiting time cost in hop-by-hop transmission and execute independently in each node, we propose a quantum bridging method with partially entangled states to teleport quantum states from source node to destination node. We also prove that the designed specific quantum bridging circuit is feasible for partially entangled states teleportation across multiple intermediate nodes. Compared to two traditional ways, our partially entanglement quantum bridging method uses simpler logic gates, has better security, and can be used in less quantum resource situation.

  9. 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...... 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....

  10. Human Errors and Bridge Management Systems

    DEFF Research Database (Denmark)

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

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

  11. Maxwell Tension Supports the Water Bridge

    OpenAIRE

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

    2008-01-01

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

  12. 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. PMID:22577536

  13. Pilot testing of a hydraulic bridge exciter

    OpenAIRE

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

    2015-01-01

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

  14. Four Engineers...

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    There are four engineers traveling in a car;a mechanical engineer,a chemical engi-neer,an electrical engineer and a comput-er engineer.The car breaks down.“Sounds to me as if the pistons have seized.We ll have to strip down the engine before we canget the car working again,”says the mechanical

  15. Translational Approaches in Tissue Engineering and Regenerative Medicine

    CERN Document Server

    Mao, Jeremy J

    2007-01-01

    This landmark book identifies the current and forthcoming roadblocks to scientific research and technological development in stem cell research, tissue engineering, wound healing, and in-vivo animal models. The book is the first to focus on the translational aspect of tissue engineering and regenerative medicine and bridges the gap between laboratory discovery and clinical applications.

  16. Desirable engineering features of the next-generation tokamak device

    International Nuclear Information System (INIS)

    Recent scoping studies examined a series of superconducting, long-pulse Driven Current Tokamak (DCT) devices. One class of options is an ignited, D-T burning device designated DCT-8. It was concluded that the DCT-8 is a most attracttive engineering option to adequately bridge the gap between the Tokamak Fusion Test Reactor (TFTR) and the Engineering Test Reactor

  17. 上承式拱梁组合桥设计%Design of combined deck type arch bridge

    Institute of Scientific and Technical Information of China (English)

    严国香

    2012-01-01

    结合某桥的工程地理位置及沿河景观要求,对该桥的结构设计特点、构造与施工要点等进行了简要介绍,目前该桥运营情况良好,并取得了一定的经济、社会效益,为同类型桥梁施工积累宝贵经验。%This paper synthesized the engineering geographic location and river landscape requirements of a bridge,simply introduced the structure design features,structure and construction key points of this bridge,present the bridge was operating in good condition,and achieved certain economic,social effect,accumulated valuable experience for the same type bridge construction.

  18. Traveling wave effect on the seismic response of a steel arch bridge subjected to near fault ground motions

    Institute of Scientific and Technical Information of China (English)

    Xu Yan; George C Lee

    2007-01-01

    In the 1990s, several major earthquakes occurred throughout the world, with a common observation that near fault ground motion (NFGM) characteristics had a distinct impact on causing damage to civil engineering structures that could not be predicted by using far field ground motions. Since then, seismic responses of structures under NFGMs have been extensively examined, with most of the studies focusing on structures with relatively short fundamental periods, where the traveling wave effect does not need to be considered. However, for long span bridges, especially arch bridges, the traveling wave (only time delay considered) effect may be very distinct and is therefore important. In this paper, the results from a case study on the seismic response of a steel arch bridge under selected NFGMs is presented by considering the traveling wave effect with variable apparent velocities. The effects of fling step and long period pulses of NFGMs on the seismic responses of the arch bridge are also discussed.

  19. A Comparison of Half Bridge & Full Bridge Isolated DC-DC Converters for Electrolysis Application

    OpenAIRE

    R.Samuel Rajesh Babu; Joseph Henry

    2011-01-01

    This paper presents a comparison of half bridgeand full bridge isolated, soft-switched, DC-DC converters forElectrolysis application. An electrolyser is a part of renewableenergy system which generates hydrogen from water electrolysisthat used in fuel cells. A DC-DC converter is required to coupleelectrolyser to system DC bus. The proposed DC-DC converter isrealized in both full-bridge and half-bridge topology in order toachieve zero voltage switching for the power switches and toregulate the...

  20. 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.

  1. Active aerodynamic stabilisation of long suspension bridges

    DEFF Research Database (Denmark)

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

    2004-01-01

    use of control analysis and design techniques, a linear model of the structural and aerodynamic motion around equilibriun is developed. The model is validated through comparison with finite element calculations and wind tunnel experimental data on the Great Belt East Bridge in Denmark. The developed......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 make...... active control scheme is local in that the flap control signal at a given longitudinal position along the bridge only depends on local motion measurements. The analysis makes use of the Nyquist stability criteria and an anlysis of the sensitivity function for stability analysis. The analysis shows that...

  2. Bridging the Chasm between Policymakers and Educators.

    Science.gov (United States)

    Marshall, Catherine

    1988-01-01

    In an attempt to lessen the tension which often exists between educators and policymakers, this article discusses each sector's world and then offers suggestions on how to construct bridges between these worlds so that mutual goals may be attained. (JL)

  3. Allegheny County-Owned Bridges Points

    Data.gov (United States)

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

  4. Allegheny County-Owned Bridges Centerlines

    Data.gov (United States)

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

  5. 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.

  6. Engineering Special

    OpenAIRE

    Duca, Edward

    2013-01-01

    Smart phones, supersonic planes, Formula 1 cars, green cities, the Internet; engineers built them all. Engineers are everywhere. The world needs them and so do you. http://www.um.edu.mt/think/engineering-special-feature-editorial/

  7. Fatigue Performance Assessment of Composite Arch Bridge Suspenders Based on Actual Vehicle Loads

    Directory of Open Access Journals (Sweden)

    Bin Chen

    2015-01-01

    Full Text Available In the through arch bridges, the suspenders are the key components connecting the arch rib and the bridge deck in the middle, and their safety is an increasing focus in the field of bridge engineering. In this study, various vehicle traffic flow parameters are investigated based on the actual vehicle data acquired from the long-term structural health monitoring system of a composite arch bridge. The representative vehicle types and the probability density functions of several parameters are determined, including the gross vehicle weight, axle weight, time headway, and speed. A finite element model of the bridge structure is constructed to determine the influence line of the cable force for various suspenders. A simulated vehicle flow, generated using the Monte Carlo method, is applied on the influence lines of the target suspender to determine the stress process, and then the stress amplitude spectrum is obtained based on the statistical analysis of the stress process using the rainflow counting method. The fatigue performance levels of various suspenders are analyzed according to the Palmgren-Miner linear cumulative damage theory, which helps to manage the safety of the suspenders.

  8. Engineering Ethics In Islam: An Evaluative And Comparative Study Between Code Of Ethics Of Institution Of Engineers, Bangladesh (Ieb) And Code Of Professional Conduct Of Board Of Engineers Malaysia (BEM)

    OpenAIRE

    Muhammad Amanullah

    2012-01-01

    During the past two centuries or so a number of buildings and bridges had been structurally failed and collapsed all over the world. Some of these incidents caused a sizeable number of human casualties. For instance, collapse of Tay Bridge in 1879 killed at least sixty persons. Beside the problems related to their design and construction, probably the failure to follow engineering ethics properly was partially responsible for these incidents. Growing engineering professionalism during the ni...

  9. Identifying hidden sexual bridging communities in Chicago.

    Science.gov (United States)

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

    2009-07-01

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

  10. Tensegrity modules for pedestrian bridges

    OpenAIRE

    Rhode-Barbarigos, Landolf; Bel Hadj Ali, Nizar; MOTRO, RENE; Smith, Ian F.C.

    2009-01-01

    p. 2221-2232 Tensegrity systems are spatial structures composed of tensile and compression components in a self-equilibrated state of prestress. The tensegrity concept offers good structural efficiency and results in modular and lightweight structures. Research into tensegrity systems has resulted in reliable techniques for form finding and structural analysis. However, designing tensegrity systems for structural engineering applications is not yet part of mainstream structural design. Ind...

  11. Experimental study of single span railway bridges

    OpenAIRE

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

    2007-01-01

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

  12. Active control of vibrations in pedestrian bridges

    OpenAIRE

    Álvaro Cunha; Carlos Moutinho

    1999-01-01

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

  13. Acoustic Emission Health Monitoring of Steel Bridges

    OpenAIRE

    Pahlavan, Pooria Lotfollah; Paulissen, Joep; Pijpers, Richard; Hakkesteegt, Henk; Jansen, Rob

    2014-01-01

    Despite extensive developments in the field of Acoustic Emission (AE) for monitoring fatigue cracks in steel structures, the implementation of AE systems for large-scale bridges is hindered by limitations associated with instrumentation costs and signal processing complexities. This paper sheds light on some of the most important challenges in the utilization of AE systems for steel bridge decks. These challenges are mainly related to the multi-modal character of guided waves, and the expensi...

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

    OpenAIRE

    Rahmann, Gerold; Aksoy, Uygun

    2014-01-01

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

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

    OpenAIRE

    Rahmann, Gerold; Aksoy, Uygun

    2014-01-01

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

  16. Differential Local Spasticity in Myocardial Bridges

    OpenAIRE

    Angelini, Paolo; Uribe, Carlo; Lozano, Pablo

    2012-01-01

    To illustrate the effect of myocardial bridges on coronary vascular tone, we describe the cases of 2 patients with different clinical presentations in the context of reproducible increased spasticity at the site of myocardial bridging. One had an episode of takotsubo cardiomyopathy, and one developed typical Prinzmetal angina while receiving desmopressin treatment for pituitary insufficiency. In both patients, acetylcholine challenge clearly revealed both the presence and the severity of myoc...

  17. Noise measurements in superconducting proximity bridges

    International Nuclear Information System (INIS)

    Experiments and analsis have been done to show that the low-frequency noise voltage developed across a current-biased proximity-coupled superconducting bridge is well described by existing theories of electron tunneling. There is also some evidence that, on a two-fluid model, normal and supercurrent noise may be correlated. The temperature sensitivity of these bridges is calculated from the measured noise spectrum and is found to compare favorably with existing bolometric techniques

  18. 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....

  19. The evaluation of bicycle paths on bridges

    OpenAIRE

    Wang, Hwa-chyi; De Backer, Hans; Lauwers, Dirk; Chang, SK Jason

    2016-01-01

    Bicycle accidents have increasingly caused casualties and property damage. Many countries have therefore started to pay more attention to designing the space of bicycle paths. However, few studies have focused on the design of bicycle continuity between each bicycle path. In this study, the concept of using both spatial crash probability (P) and crash severity index (CSI) is introduced to address the bicycle safety issue on bridges in Central Business Districts (CBDs). Bicycle paths on bridge...

  20. 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.

  1. Subscapularis Tendon Repair Using Suture Bridge Technique

    OpenAIRE

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

    2015-01-01

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

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

    OpenAIRE

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

    2011-01-01

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

  3. Remote Bridge Deflection Measurement Using an Advanced Video Deflectometer and Actively Illuminated LED Targets.

    Science.gov (United States)

    Tian, Long; Pan, Bing

    2016-01-01

    An advanced video deflectometer using actively illuminated LED targets is proposed for remote, real-time measurement of bridge deflection. The system configuration, fundamental principles, and measuring procedures of the video deflectometer are first described. To address the challenge of remote and accurate deflection measurement of large engineering structures without being affected by ambient light, the novel idea of active imaging, which combines high-brightness monochromatic LED targets with coupled bandpass filter imaging, is introduced. Then, to examine the measurement accuracy of the proposed advanced video deflectometer in outdoor environments, vertical motions of an LED target with precisely-controlled translations were measured and compared with prescribed values. Finally, by tracking six LED targets mounted on the bridge, the developed video deflectometer was applied for field, remote, and multipoint deflection measurement of the Wuhan Yangtze River Bridge, one of the most prestigious and most publicized constructions in China, during its routine safety evaluation tests. Since the proposed video deflectometer using actively illuminated LED targets offers prominent merits of remote, contactless, real-time, and multipoint deflection measurement with strong robustness against ambient light changes, it has great potential in the routine safety evaluation of various bridges and other large-scale engineering structures. PMID:27563901

  4. 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 of Con...... Concrete Structures using Reliability Based Expert Systems"....

  5. TMACS test procedure TP012: Panalarm software bridge

    International Nuclear Information System (INIS)

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

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

    DEFF Research Database (Denmark)

    Hansen, Poul Erik; Williamson, Michael P.; Hounslow, Andrea M.; Ford, Joe; Fowler, Kyle; Hebditch, Max

    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....

  7. Precast Pearl-Chain concrete arch bridges

    DEFF Research Database (Denmark)

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

    2015-01-01

    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......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 of...... number of post-tensioning cables, the rise to span ratio, the height of the filling, and the height of the Super-Light Decks. We find that Pearl-Chain Bridges can be adjusted to resist specific moment loads by changing the normal force in the arch cross section by altering the above parameters. It is...

  8. 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.

  9. Engineering and Software Engineering

    Science.gov (United States)

    Jackson, Michael

    The phrase ‘software engineering' has many meanings. One central meaning is the reliable development of dependable computer-based systems, especially those for critical applications. This is not a solved problem. Failures in software development have played a large part in many fatalities and in huge economic losses. While some of these failures may be attributable to programming errors in the narrowest sense—a program's failure to satisfy a given formal specification—there is good reason to think that most of them have other roots. These roots are located in the problem of software engineering rather than in the problem of program correctness. The famous 1968 conference was motivated by the belief that software development should be based on “the types of theoretical foundations and practical disciplines that are traditional in the established branches of engineering.” Yet after forty years of currency the phrase ‘software engineering' still denotes no more than a vague and largely unfulfilled aspiration. Two major causes of this disappointment are immediately clear. First, too many areas of software development are inadequately specialised, and consequently have not developed the repertoires of normal designs that are the indispensable basis of reliable engineering success. Second, the relationship between structural design and formal analytical techniques for software has rarely been one of fruitful synergy: too often it has defined a boundary between competing dogmas, at which mutual distrust and incomprehension deprive both sides of advantages that should be within their grasp. This paper discusses these causes and their effects. Whether the common practice of software development will eventually satisfy the broad aspiration of 1968 is hard to predict; but an understanding of past failure is surely a prerequisite of future success.

  10. Engineering ceramics

    CERN Document Server

    Bengisu, Murat

    2001-01-01

    This is a comprehensive book applying especially to junior and senior engineering students pursuing Materials Science/ Engineering, Ceramic Engineering and Mechanical Engineering degrees. It is also a reference book for other disciplines such as Chemical Engineering, Biomedical Engineering, Nuclear Engineering and Environmental Engineering. Important properties of most engineering ceramics are given in detailed tables. Many current and possible applications of engineering ceramics are described, which can be used as a guide for materials selection and for potential future research. While covering all relevant information regarding raw materials, processing properties, characterization and applications of engineering ceramics, the book also summarizes most recent innovations and developments in this field as a result of extensive literature search.

  11. Response Modification Factors for Concrete Bridges in Europe

    OpenAIRE

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

    2013-01-01

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

  12. Structural damage diagnosis of steel truss bridges by outlier detection

    OpenAIRE

    Kim, C. W.; Kitauchi, S.; Chang, K. C.; McGetrick, P. J.; Sugiura, K.; Kawatani, M.

    2014-01-01

    This study discusses structural damage diagnosis of real steel truss bridges by measuring trafficinduced vibration of bridges and utilizing a damage indicator derived from linear system parameters of a time series model. On-site damage experiments were carried out on real steel truss bridges. Artificial damage was applied to the bridge by severing a truss member with a cutting machine.Vehicle-induced vibrations of the bridges before and after applying damagewere measured and used in structura...

  13. Coronary atherosclerosis within a myocardial bridge, not a benign condition

    OpenAIRE

    Winter, de, A.J.; Kok, W.E.M.; Piek, J.J.

    1998-01-01

    In patients with myocardial bridging, the area within the bridge usually remains free from atherosclerotic disease. The case of a 47 year old man is described who had the rare combination of myocardial bridging with an atherosclerotic plaque within the area of bridging, which was detected with intravascular ultrasound but not with coronary angiography. The clinical history of the patient demonstrates that this is not a benign condition. In symptomatic patients the bridged segment should be sc...

  14. Scaling London’s early XIXth century docks, bridges and manufactories :Charles Dupin’s writings andtechnological exchange

    OpenAIRE

    Werner, Alex

    2011-01-01

    Charles Dupin contributed to technological exchange between Britain and France. He provided French readers with a detailed survey of London’s new docks, bridges and manufactories analysing commercial and operational systems alongside engineering and architectural innovations. Dupin’s influence was not limited just to France but extended to Britain also through the translation of his works. Indian engineers who trained in London provide a different focus to technological exchange extending to ...

  15. Investigation of Strouhal number of iced cable model of cable-supported bridges with respect to angle of wind attack

    Czech Academy of Sciences Publication Activity Database

    Górski, P.; Pospíšil, Stanislav; Kuznetsov, Sergeii; Tatara, M.; Marušić, Ante

    Lublin: Polish Association for Wind Engineering, 2014 - (Lipecki, T.; Flaga, A.), s. 103-104 ISBN 978-83-932544-9-1. [International Symposium on Environmental Effects on Buildings and People /7./. Lublin - Krakow (PL), 20.10.2014-22.10.2014] R&D Projects: GA MŠk(CZ) LO1219; GA MPO(CZ) FR-TI3/654 Keywords : bridge cable * ice accretion * Strouhal number * angle of attack * vortex shedding frequency Subject RIV: JN - Civil Engineering

  16. 76 FR 20807 - Notice of Final Federal Agency Actions on the Sellwood Bridge Project, SE Tacoma Street and...

    Science.gov (United States)

    2011-04-13

    ... Tacoma Street and Oregon Highway 43, Multnomah County, OR AGENCY: Federal Highway Administration (FHWA... project, Sellwood Bridge, SE Tacoma Street and Oregon 43, in Multnomah County, Oregon. This action grants... Graham, Operations Engineer, Federal Highway Administration, 530 Center Street, NE., Suite 100,...

  17. Design and implementation of a monitoring system applied to a long-span prestressed concrete bridge

    OpenAIRE

    H. Sousa; Figueiras, J; Félix, C; Bento, J.

    2011-01-01

    Currently, long-term monitoring systems are mandatory for major civil engineering structures such as bridges, tunnels and dams. Generally, they monitor a set of physical, chemical and mechanical parameters in critical sections of the structure by incorporating appropriate sensors. The set of data collected demonstrates great potential in the prevention of damage and contributes to more efficient maintenance of the structures monitored. This work presents the long-term monitoring system instal...

  18. Strouhal number of bridge cables with ice accretion at low flow turbulence

    Czech Academy of Sciences Publication Activity Database

    Górski, P.; Pospíšil, Stanislav; Kuznetsov, Sergeii; Tatara, M.; Marušić, Ante

    2016-01-01

    Roč. 22, č. 2 (2016), s. 253-272. ISSN 1226-6116 R&D Projects: GA MŠk(CZ) LO1219; GA ČR(CZ) GC13-34405J; GA ČR(CZ) GA14-12892S Keywords : bridge cable * ice accretion * Strouhal number * angle of attack * vortex shedding frequency Subject RIV: JM - Building Engineering Impact factor: 0.584, year: 2014

  19. Problems connected with the application of lamella flanges in steel bridge construction

    Czech Academy of Sciences Publication Activity Database

    Křístek, V.; Kunrt, J.; Škaloud, Miroslav; Urushadze, Shota

    Bratislava : Slovak University of Technology in Bratislava, 2014 - (Jendželovský, N.; Grmanová, A.), s. 303-308 ISBN 978-80-227-4259-7. [International Conference on New Trends in Statics and Dynamics of Buildings. Bratislava (SK), 16.10.2014-17.10.2014] Institutional support: RVO:68378297 Keywords : cumulative damage * fatigue * lamella flanges * lifetime * steel bridges Subject RIV: JM - Building Engineering http://www.newtrends.sk/dokumenty/proceedings_2014.pdf

  20. Applicability of URANS and DES Simulations of Flow Past Rectangular Cylinders and Bridge Sections

    OpenAIRE

    Claudio Mannini

    2015-01-01

    This paper discusses the results of computational fluid dynamics simulations carried out for rectangular cylinders with various side ratios of interest for many civil engineering structures. A bridge deck of common cross-section geometry was also considered. Unsteady Reynolds-averaged Navier-Stokes (URANS) equations were solved in conjunction with either an eddy-viscosity or a linearized explicit algebraic Reynolds stress model. The analysis showed that for the case studies considered the 2-D...

  1. Parallels between wind and crowd loading of bridges.

    Science.gov (United States)

    McRobie, Allan; Morgenthal, Guido; Abrams, Danny; Prendergast, John

    2013-06-28

    Parallels between the dynamic response of flexible bridges under the action of wind and under the forces induced by crowds allow each field to inform the other. Wind-induced behaviour has been traditionally classified into categories such as flutter, galloping, vortex-induced vibration and buffeting. However, computational advances such as the vortex particle method have led to a more general picture where effects may occur simultaneously and interact, such that the simple semantic demarcations break down. Similarly, the modelling of individual pedestrians has progressed the understanding of human-structure interaction, particularly for large-amplitude lateral oscillations under crowd loading. In this paper, guided by the interaction of flutter and vortex-induced vibration in wind engineering, a framework is presented, which allows various human-structure interaction effects to coexist and interact, thereby providing a possible synthesis of previously disparate experimental and theoretical results. PMID:23690640

  2. Six new projects will bridge gap between CERN and society

    CERN Multimedia

    Anaïs Rassat, Knowledge Transfer Group

    2016-01-01

    Knowledge Transfer Fund awarded over six hundred thousand Swiss francs to six projects in 2016.   Computer racks at the CERN Data Centre, the heart of CERN’s entire scientific, administrative, and computing infrastructure. CERN has awarded funding to six new projects with the aim to bridge the gap between technology and society. Over 600,000 CHF (€ 542,766) of capital was granted through its competitive Knowledge Transfer Fund (KT Fund). The fund is issued as part of CERN’s goal to maximize its overall impact on society. The selected projects cover new applications for CERN technology in a broad range of fields beyond high-energy physics, ranging from cancer diagnostics and aerospace applications, to next-generation cloud computing, radiation safety, and digital preservation. The technologies were developed at CERN as part of the variety of high-energy physics needs, and arise from several research departments: Engineering, Information Technology, Be...

  3. Testing of the masonry arches of the Brooklyn Bridge approaches

    Science.gov (United States)

    Limaye, Hemant S.

    1996-11-01

    Diagnostic procedures play an important role in performing a condition survey of a structure. Specialized tests are used during a field survey to supplement visual observations. The tests provide valuable information regarding the internal condition of the structure and quality of the construction materials. The tests also help in determining the extent of damage, if any. Recently, a team of consulting engineers performed a study to determine the remaining capacity of the Brooklyn Bridge approaches for the Department of Transportation, City of New York. Using advanced diagnostic procedures such as impact-echo and flatjack testing, additional information was gathered to assist in the study. Impact-echo testing was helpful in identifying the condition of the brick soffits which were covered with pneumatically- applied concrete, and flatjack testing was useful in determining in-situ compressive strength and compression modulus of the brick masonry. The paper describes the work and the testing results.

  4. Institute-Industry Interoperation Model: An Industry-Oriented Engineering Education Strategy in China

    Science.gov (United States)

    Wang, Yanqing; Qi, Zhongying; Li, Ziru; Zhang, Lijie

    2011-01-01

    Engineering education has been well implemented in the majority of developed countries such as the USA, Germany, and the United Kingdom so that the gap between engineering science and engineering practice is greatly bridged. However, in China, the gap still exists, and some attempts by Chinese government, even though having made obvious progress,…

  5. Neural Engineering

    Science.gov (United States)

    He, Bin

    About the Series: Bioelectric Engineering presents state-of-the-art discussions on modern biomedical engineering with respect to applications of electrical engineering and information technology in biomedicine. This focus affirms Springer's commitment to publishing important reviews of the broadest interest to biomedical engineers, bioengineers, and their colleagues in affiliated disciplines. Recent volumes have covered modeling and imaging of bioelectric activity, neural engineering, biosignal processing, bionanotechnology, among other topics.

  6. Mechanical engineering

    CERN Document Server

    Darbyshire, Alan

    2010-01-01

    Alan Darbyshire's best-selling text book provides five-star high quality content to a potential audience of 13,000 engineering students. It explains the most popular specialist units of the Mechanical Engineering, Manufacturing Engineering and Operations & Maintenance Engineering pathways of the new 2010 BTEC National Engineering syllabus. This challenging textbook also features contributions from specialist lecturers, ensuring that no stone is left unturned.

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

    Directory of Open Access Journals (Sweden)

    Lei Su-su

    2015-01-01

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

  8. Tidal Energy Conversion Installation at an Estuarine Bridge Site: Resource Evaluation and Energy Production Estimate

    Science.gov (United States)

    Wosnik, M.; Gagnon, I.; Baldwin, K.; Bell, E.

    2015-12-01

    The "Living Bridge" project aims to create a self-diagnosing, self-reporting "smart bridge" powered by a local renewable energy source, tidal energy - transforming Memorial Bridge, a vertical lift bridge over the tidal Piscataqua River connecting Portsmouth, NH and Kittery, ME, into a living laboratory for researchers, engineers, scientists, and the community. The Living Bridge project includes the installation of a tidal turbine at the Memorial Bridge. The energy converted by the turbine will power structural health monitoring, environmental and underwater instrumentation. Utilizing locally available tidal energy can make bridge operation more sustainable, can "harden" transportation infrastructure against prolonged grid outages and can demonstrate a prototype of an "estuarine bridge of the future". A spatio-temporal tidal energy resource assessment was performed using long term bottom-deployed Acoustic Doppler Current Profilers (ADCP) at two locations: near the planned deployment location in 2013-14 for 123 days and mid-channel in 2007 for 35 days. Data were evaluated to determine the amount of available kinetic energy that can be converted into usable electrical energy on the bridge. Changes in available kinetic energy with ebb/flood and spring/neap tidal cycles and electrical energy demand were analyzed. The target deployment site exhibited significantly more energetic ebb tides than flood tides, which can be explained by the local bathymetry of the tidal estuary. A system model is used to calculate the net energy savings using various tidal generator and battery bank configurations. Different resource evaluation methodologies were also analyzed, e.g., using a representative ADCP "bin" vs. a more refined, turbine-geometry-specific methodology, and using static bin height vs. bin height that move w.r.t. the free surface throughout a tidal cycle (representative of a bottom-fixed or floating turbine deployment, respectively). ADCP operating frequencies and bin

  9. Comparison of flutter derivatives for Kao Pin Hsi Bridge and flat plate

    Czech Academy of Sciences Publication Activity Database

    Buljac, A.; Pospíšil, Stanislav; Kozmar, H.; Kuznetsov, Sergeii; Král, Radomil

    Prague: Institute of theoretical and applied mechanics, Academy of Sciences of the Czech Republic, v. v. i., 2015 - (Náprstek, J.; Fischer, C.), s. 36-37 ISBN 978-80-86246-42-0. ISSN 1805-8248. [Engineering mechanics 2015 /21./. Svratka (CZ), 11.05.2015-14.05.2015] R&D Projects: GA ČR(CZ) GC13-34405J; GA ČR(CZ) GA15-01035S Institutional support: RVO:68378297 Keywords : bridge-deck section * vibrations * aeroelasticity * flutter derivatives * wind-tunnel experiments Subject RIV: JM - Building Engineering

  10. Bridges in the random-cluster model

    Science.gov (United States)

    Elçi, Eren Metin; Weigel, Martin; Fytas, Nikolaos G.

    2016-02-01

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

  11. A probabilistic bridge safety evaluation against floods.

    Science.gov (United States)

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

    2016-01-01

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

  12. 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.

  13. Useful features in the damage detection of bridges

    International Nuclear Information System (INIS)

    This study develops a method for detecting damages in a bridge. A truck is driven at constant speed through a target bridge. The elongations of the bridge are recorded by the sensors mounted on the bridge. It is found that the signals can reflect the health condition of the bridge faithfully. Furthermore, by examining the maximum and minimum of the signals, one can determine the damage levels and locations of the bridge easily. Hence, the extreme values of the elongations are useful features in the damage detection of bridges. Based on the proposed features, a health monitoring system of the bridge is developed using artificial neural networks. The numerical example shows that the monitoring system is effective in the damage detection of the bridge.

  14. Statistical inference for financial engineering

    CERN Document Server

    Taniguchi, Masanobu; Ogata, Hiroaki; Taniai, Hiroyuki

    2014-01-01

    This monograph provides the fundamentals of statistical inference for financial engineering and covers some selected methods suitable for analyzing financial time series data. In order to describe the actual financial data, various stochastic processes, e.g. non-Gaussian linear processes, non-linear processes, long-memory processes, locally stationary processes etc. are introduced and their optimal estimation is considered as well. This book also includes several statistical approaches, e.g., discriminant analysis, the empirical likelihood method, control variate method, quantile regression, realized volatility etc., which have been recently developed and are considered to be powerful tools for analyzing the financial data, establishing a new bridge between time series and financial engineering. This book is well suited as a professional reference book on finance, statistics and statistical financial engineering. Readers are expected to have an undergraduate-level knowledge of statistics.

  15. 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.

  16. Bridging radiation policy and science

    International Nuclear Information System (INIS)

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

  17. Documentation for assessment of modal pushover-based scaling procedure for nonlinear response history analysis of "ordinary standard" bridges

    Science.gov (United States)

    Kalkan, Erol; Kwong, Neal S.

    2010-01-01

    The earthquake engineering profession is increasingly utilizing nonlinear response history analyses (RHA) to evaluate seismic performance of existing structures and proposed designs of new structures. One of the main ingredients of nonlinear RHA is a set of ground-motion records representing the expected hazard environment for the structure. When recorded motions do not exist (as is the case for the central United States), or when high-intensity records are needed (as is the case for San Francisco and Los Angeles), ground motions from other tectonically similar regions need to be selected and scaled. The modal-pushover-based scaling (MPS) procedure recently was developed to determine scale factors for a small number of records, such that the scaled records provide accurate and efficient estimates of 'true' median structural responses. The adjective 'accurate' refers to the discrepancy between the benchmark responses and those computed from the MPS procedure. The adjective 'efficient' refers to the record-to-record variability of responses. Herein, the accuracy and efficiency of the MPS procedure are evaluated by applying it to four types of existing 'ordinary standard' bridges typical of reinforced-concrete bridge construction in California. These bridges are the single-bent overpass, multi span bridge, curved-bridge, and skew-bridge. As compared to benchmark analyses of unscaled records using a larger catalog of ground motions, it is demonstrated that the MPS procedure provided an accurate estimate of the engineering demand parameters (EDPs) accompanied by significantly reduced record-to-record variability of the responses. Thus, the MPS procedure is a useful tool for scaling ground motions as input to nonlinear RHAs of 'ordinary standard' bridges.

  18. Cracking behavior of structural slab bridge decks

    Science.gov (United States)

    Baah, Prince

    Bridge deck cracking is a common problem throughout the United States, and it affects the durability and service life of concrete bridges. Several departments of transportation (DOTs) in the United States prefer using continuous three-span solid structural slab bridges without stringers over typical four-lane highways. Recent inspections of such bridges in Ohio revealed cracks as wide as 0.125 in. These measured crack widths are more than ten times the maximum limit recommended in ACI 224R-01 for bridge decks exposed to de-icing salts. Measurements using digital image correlation revealed that the cracks widened under truck loading, and in some cases, the cracks did not fully close after unloading. This dissertation includes details of an experimental investigation of the cracking behavior of structural concrete. Prism tests revealed that the concrete with epoxy-coated bars (ECB) develops the first crack at smaller loads, and develops larger crack widths compared to the corresponding specimens with uncoated (black) bars. Slab tests revealed that the slabs with longitudinal ECB developed first crack at smaller loads, exhibited wider cracks and a larger number of cracks, and failed at smaller ultimate loads compared to the corresponding test slabs with black bars. To develop a preventive measure, slabs with basalt and polypropylene fiber reinforced concrete were also included in the test program. These test slabs exhibited higher cracking loads, smaller crack widths, and higher ultimate loads at failure compared to the corresponding slab specimens without fibers. Merely satisfying the reinforcement spacing requirements given in AASHTO or ACI 318-11 is not adequate to limit cracking below the ACI 224R-01 recommended maximum limit, even though all the relevant design requirements are otherwise met. Addition of fiber to concrete without changing any steel reinforcing details is expected to reduce the severity and extent of cracking in reinforced concrete bridge decks.

  19. MULTIPHASE BLASTING OF THE BRIDGE ACROSS THE DRENICA RIVER

    OpenAIRE

    Branko Božić

    1989-01-01

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

  20. The mechanics of ship impacts against bridges

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup; Zhang, Shengming

    1998-01-01

    information is introduced in a mathematical model for estimation of the return period for collisions with bridge piers and girders. A new mathematical model is thereafter presented for calculation of the energies released for crushing of structures given a specific collision scenario which may include 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...

  1. 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....

  2. Germanium-overcoated niobium Dayem bridges

    Science.gov (United States)

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

    1976-01-01

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

  3. 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.

  4. NDT evaluation of long-term bond durability of CFRP-structural systems applied to RC highway bridges

    Science.gov (United States)

    Crawford, Kenneth C.

    2016-03-01

    The long-term durability of CFRP structural systems applied to reinforced-concrete (RC) highway bridges is a function of the system bond behavior over time. The sustained structural load performance of strengthened bridges depends on the carbon fiber-reinforced polymer (CFRP) laminates remaining 100 % bonded to concrete bridge members. Periodic testing of the CFRP-concrete bond condition is necessary to sustain load performance. The objective of this paper is to present a non-destructive testing (NDT) method designed to evaluate the bond condition and long-term durability of CFRP laminate (plate) systems applied to RC highway bridges. Using the impact-echo principle, a mobile mechanical device using light impact hammers moving along the length of a bonded CFRP plate produces unique acoustic frequencies which are a function of existing CFRP plate-concrete bond conditions. The purpose of this method is to test and locate CFRP plates de-bonded from bridge structural members to identify associated deterioration in bridge load performance. Laboratory tests of this NDT device on a CFRP plate bonded to concrete with staged voids (de-laminations) produced different frequencies for bonded and de-bonded areas of the plate. The spectra (bands) of frequencies obtained in these tests show a correlation to the CFRP-concrete bond condition and identify bonded and de-bonded areas of the plate. The results of these tests indicate that this NDT impact machine, with design improvements, can potentially provide bridge engineers a means to rapidly evaluate long lengths of CFRP laminates applied to multiple highway bridges within a national transportation infrastructure.

  5. NDT evaluation of long-term bond durability of CFRP-structural systems applied to RC highway bridges

    Science.gov (United States)

    Crawford, Kenneth C.

    2016-06-01

    The long-term durability of CFRP structural systems applied to reinforced-concrete (RC) highway bridges is a function of the system bond behavior over time. The sustained structural load performance of strengthened bridges depends on the carbon fiber-reinforced polymer (CFRP) laminates remaining 100 % bonded to concrete bridge members. Periodic testing of the CFRP-concrete bond condition is necessary to sustain load performance. The objective of this paper is to present a non-destructive testing (NDT) method designed to evaluate the bond condition and long-term durability of CFRP laminate (plate) systems applied to RC highway bridges. Using the impact-echo principle, a mobile mechanical device using light impact hammers moving along the length of a bonded CFRP plate produces unique acoustic frequencies which are a function of existing CFRP plate-concrete bond conditions. The purpose of this method is to test and locate CFRP plates de-bonded from bridge structural members to identify associated deterioration in bridge load performance. Laboratory tests of this NDT device on a CFRP plate bonded to concrete with staged voids (de-laminations) produced different frequencies for bonded and de-bonded areas of the plate. The spectra (bands) of frequencies obtained in these tests show a correlation to the CFRP-concrete bond condition and identify bonded and de-bonded areas of the plate. The results of these tests indicate that this NDT impact machine, with design improvements, can potentially provide bridge engineers a means to rapidly evaluate long lengths of CFRP laminates applied to multiple highway bridges within a national transportation infrastructure.

  6. Engineering Cartilage

    Science.gov (United States)

    ... Research Matters NIH Research Matters March 3, 2014 Engineering Cartilage Artistic rendering of human stem cells on ... situations has been a major goal in tissue engineering. Cartilage contains water, collagen, proteoglycans, and chondrocytes. Collagens ...

  7. Governing Engineering

    DEFF Research Database (Denmark)

    Buch, Anders

    2011-01-01

    Abstract: Most people agree that our world faces daunting problems and, correctly or not, technological solutions are seen as an integral part of an overall solution. But what exactly are the problems and how does the engineering ‘mind set’ frame these problems? This chapter sets out to unravel...... dominant perspectives in challenge perception in engineering in the US and Denmark. Challenge perception and response strategies are closely linked through discursive practices. Challenge perceptions within the engineering community and the surrounding society are thus critical for the shaping of...... engineering education and the engineering profession. Through an analysis of influential reports and position papers on engineering and engineering education the chapter sets out to identify how engineering is problematized and eventually governed. Drawing on insights from governmentality studies the chapter...

  8. Prosthetic Engineering

    Science.gov (United States)

    ... Overview CoE for Limb Loss Prevention and Prosthetic Engineering Menu Menu VA Center of Excellence for Limb ... ZIP code here Enter ZIP code here Prosthetic Engineering - Overview Our aim is to improve prosthetic prescription ...

  9. Industrial Engineering

    DEFF Research Database (Denmark)

    Karlsson, Christer

    2015-01-01

    Industrial engineering is a discipline that is concerned with increasing the effectiveness of (primarily) manufacturing and (occasionally).......Industrial engineering is a discipline that is concerned with increasing the effectiveness of (primarily) manufacturing and (occasionally)....

  10. Engineering economy

    International Nuclear Information System (INIS)

    This book is written for engineer and manager who is working for analysis of propriety of project. It gives descriptions of basic of engineering economy, compare principle of engineering economy, application of compare principle, evaluation of capital project, value of time of funds and evaluation of investment, engineering economy analysis of an alternative idea, depreciation, determination and principle analysis of uncertain prospect, analysis of propriety of project, profitable plan in product progress, quality, cost and profit and analysis of complex investment project.

  11. Toward structural mechanics through wooden bridges in France (1716-1841)

    CERN Document Server

    Tardini, Chiara

    2014-01-01

    Early applications of Navier’s beam theory to the rational design of structures are documented in the Annales of the French Ecole des Ponts et Chaussées and refer to the design of three wooden bridges built in France in the 1840's. Revisiting these examples, the book provides documentation on the progressive establishment of the new design approach, based on the theory of structural mechanics rather than empirical knowledge. The bridges concerned were built according to the structural scheme patented by Ithiel Town in the USA, witnessing the diffusion in Europe of the American advancements in bridge design, circulated by the travel reports of French engineers from the Ecole. Through the exam of French treatises discussing the progress of theoretical formulations in parallel with experimental findings in the 18th and 19th centuries, the book retraces as well the long path which led to the formulation of Navier’s theory. The relevant scientific debate dealt mainly with the specific case of wood bridges; th...

  12. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3770 Temporary crown and bridge resin. (a... polymethylmethacrylate, intended to make a temporary prosthesis, such as a crown or bridge, for use until a...

  13. 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,...

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

    Science.gov (United States)

    Harrison, D. R.; Dimeff, J.

    1972-01-01

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

  15. 49 CFR 236.766 - Locking, movable bridge.

    Science.gov (United States)

    2010-10-01

    ..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.766 Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers, and electric...

  16. Violin Bridge Mobility Analysis under In-Plane Excitation

    Directory of Open Access Journals (Sweden)

    Cheng-Zhong Zhang

    2013-11-01

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

  17. 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,…

  18. Bridging the Gap Between Theory and Practice

    Directory of Open Access Journals (Sweden)

    Roy H.M. Sembel

    2015-05-01

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

  19. “On a bridge in Berlin”

    DEFF Research Database (Denmark)

    Pihl, Ole Verner

    2013-01-01

    This is a self-reflective case study based on the development of the Graphic Novel: “On a bridge in Berlin.” The GN will be used as an introduction to the history of architecture as a part of the curriculum in Architecture and Design at Aalborg University, and as a more broadly introduction to an...

  20. Health Professions Education: A Bridge to Quality

    Science.gov (United States)

    Greiner, Ann C., Ed.; Knebel, Elisa, Ed.

    2003-01-01

    The Institute of Medicine study Crossing the Quality Chasm (2001) recommended that an interdisciplinary summit be held to further reform of health professions education in order to enhance quality and patient safety. Health Professions Education: A Bridge to Quality is the follow up to that summit, held in June 2002, where 150 participants across…

  1. 75 FR 41281 - Bridge Safety Standards

    Science.gov (United States)

    2010-07-15

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

  2. Bridges in Mathematics. WWC Intervention Report

    Science.gov (United States)

    What Works Clearinghouse, 2009

    2009-01-01

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

  3. Bridging gaps : ten crosscurrents in media studies

    OpenAIRE

    Fornäs, Johan

    2008-01-01

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

  4. 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. Characterization and electrical modeling of semiconductors bridges

    Energy Technology Data Exchange (ETDEWEB)

    Marx, K.D. [Sandia National Labs., Livermore, CA (United States); Bickes, R.W. Jr.; Wackerbarth, D.E. [Sandia National Labs., Albuquerque, NM (United States)

    1997-03-01

    Semiconductor bridges (SCBs) are finding increased use as initiators for explosive and pyrotechnic devices. They offer advantages in reduced voltage and energy requirements, coupled with excellent safety features. The design of explosive systems which implement either SCBs or metal bridgewires can be facilitated through the use of electrical simulation software such as the PSpice{reg_sign} computer code. A key component in the electrical simulation of such systems is an electrical model of the bridge. This report has two objectives: (1) to present and characterize electrical data taken in tests of detonators which employ SCBs with BNCP as the explosive powder; and (2) to derive appropriate electrical models for such detonators. The basis of such models is a description of the resistance as a function of energy deposited in the SCB. However, two important features which must be added to this are (1) the inclusion of energy loss through such mechanisms as ohmic heating of the aluminum lands and heat transfer from the bridge to the surrounding media; and (2) accounting for energy deposited in the SCB through heat transfer to the bridge from the explosive powder after the powder ignites. The modeling procedure is entirely empirical; i.e., models for the SCB resistance and the energy gain and loss have been estimated from experimental data taken over a range of firing conditions. We present results obtained by applying the model to the simulation of SCB operation in representative tests.

  6. Bridging the Gap: Pracademics in Foreign Policy

    Science.gov (United States)

    Murphy, Ann Marie; Fulda, Andreas

    2011-01-01

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

  7. 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 ...... full-span erection method....

  8. 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.

  9. Circuit bridging of components by smoke

    International Nuclear Information System (INIS)

    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 CO2 as a fire suppressant, the presence of galvanic metal, and the presence of PVC did not significantly affect the outcome of these results

  10. The Memory Bridge Initiative on Service Learners

    Science.gov (United States)

    Wescott, Amy; Healy, Tara C.

    2011-01-01

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

  11. 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.

  12. Characteristics of mortars from ancient bridges

    Czech Academy of Sciences Publication Activity Database

    Frankeová, Dita; Slížková, Zuzana; Drdácký, Miloš

    Vol. 7. Dordrecht : Springer, 2012 - (Válek, J.; Hughes, J.; Groot, J.), s. 165-174 ISBN 978-94-007-4634-3 R&D Projects: GA ČR(CZ) GA103/09/2067; GA MŠk(CZ) LA09008 Institutional support: RVO:68378297 Keywords : mortars * ancient bridges * analytical methods Subject RIV: AL - Art, Architecture, Cultural Heritage

  13. 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...

  14. Seismic Passive Control of Cable-Stayed Bridges

    OpenAIRE

    Ali, Hosam-Eddin M.; Abdel-Ghaffar, Ahmed M.

    1995-01-01

    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...

  15. New Philosophy in Steel Bridge Design and Frabrication

    OpenAIRE

    Henkle, David

    2014-01-01

    The foremost parameters in the design of any structure are safety and cost. The SEBD (simplified economical bridge design) concept meets and exceeds all conditions of safety but with an added benefit of cost savings over more conventional design procedures for steel bridges. Comparative analysis indicates that cost saving as much as 10 percent of the bridge cost can be realized. Learn about SEBD and how you can apply it to steel bridge design and fabrication. Contact InformationTele: 574-2...

  16. 305 Building 2 ton bridge crane and monorail assembly analysis

    International Nuclear Information System (INIS)

    The analyses in the appendix of this document evaluate the integrity of the existing bridge crane structure, as depicted on drawing H-3-34292, for a bridge crane and monorail assembly with a load rating of 2 tons. This bridge crane and monorail assembly is a modification of a 1 1/2 ton rated manipulator bridge crane which originally existed in the 305 building

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

    OpenAIRE

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

    2013-01-01

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

  18. Non-minimal bridge positions of torus knots are stabilized

    OpenAIRE

    Ozawa, Makoto

    2010-01-01

    We show that any non-minimal bridge decomposition of a torus knot is stabilized and that $n$-bridge decompositions of a torus knot are unique for any integer $n$. This implies that a knot in a bridge position is a torus knot if and only if there exists a torus containing the knot such that it intersects the bridge sphere in two essential loops.

  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 to...... the direction of the wind and occur when the bridge is exposed to wind velocity above critical value called the flutter wind velocity Ucr....

  20. Rupture of an Evaporating Liquid Bridge between Two Grains

    OpenAIRE

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

    2014-01-01

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

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

    OpenAIRE

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

    2012-01-01

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

  2. TorBricks: Blocking-Resistant Tor Bridge Distribution

    OpenAIRE

    Zamani, Mahdi; Saia, Jared; Crandall, Jedidiah

    2016-01-01

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

  3. Computational engineering

    CERN Document Server

    2014-01-01

    The book presents state-of-the-art works in computational engineering. Focus is on mathematical modeling, numerical simulation, experimental validation and visualization in engineering sciences. In particular, the following topics are presented: constitutive models and their implementation into finite element codes, numerical models in nonlinear elasto-dynamics including seismic excitations, multiphase models in structural engineering and multiscale models of materials systems, sensitivity and reliability analysis of engineering structures, the application of scientific computing in urban water management and hydraulic engineering, and the application of genetic algorithms for the registration of laser scanner point clouds.

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

    OpenAIRE

    Marin, Alvaro G.; Lohse, Detlef

    2010-01-01

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

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

    OpenAIRE

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

    2012-01-01

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

  6. Architectural Engineers

    DEFF Research Database (Denmark)

    Petersen, Rikke Premer

    engineering is addresses from two perspectives – as an educational response and an occupational constellation. Architecture and engineering are two of the traditional design professions and they frequently meet in the occupational setting, but at educational institutions they remain largely estranged. The...... paper builds on a multi-sited study of an architectural engineering program at the Technical University of Denmark and an architectural engineering team within an international engineering consultancy based on Denmark. They are both responding to new tendencies within the building industry where the...... role of engineers and architects increasingly overlap during the design process, but their approaches reflect different perceptions of the consequences. The paper discusses some of the challenges that design education, not only within engineering, is facing today: young designers must be equipped with...

  7. 49 CFR 237.31 - Adoption of bridge management programs.

    Science.gov (United States)

    2010-10-01

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

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

    DEFF Research Database (Denmark)

    Du, Guangli; Pettersson, Lars; Karoumi, Raid

    2016-01-01

    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...

  9. Bridged Quaterphenyls as Flashlamp-Pumpable Laser Dyes

    OpenAIRE

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

    1987-01-01

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

  10. 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 includi...

  11. CONTROL ENGINEERING ON BOARD

    Directory of Open Access Journals (Sweden)

    Serghei RADU

    2012-11-01

    Full Text Available Control engineering embraces instrumentation, alarm systems, control of machinery and plant previously known under the misnomer of automation. Control engineering can be applied not only to propelling and auxiliary machinery but also to electrical installations, refrigeration, cargo handling (especially in tankers and deck machinery, e.g. Windlass control. Opinion still vary on such matters as the relative merits of pneumatic versus electronic system and whether the control center should be in the engine room or adjacent to the navigating bridge. Arguments against the exclusion of the engineer officer from close contact with the machinery are countered by the fact that electronic systems are based on changes other than those of human response. Automated ships (UMS operate closer to prescribed standards and therefore operate with greater efficiency. The closer control of machinery operating conditions, e.g. cooling water temperatures and pressures, permits machinery to be run at its optimum design conditions, making for fuel economy and reduced maintenance. Automation can carry out some tasks far more effectively than men. In other areas it is less effective. For example, the monitoring of machinery operating conditions such as the temperatures and pressures can be carried out by a solid state alarm scanning system at the rate of 400 channels/sec., giving a degree of surveillance which would be impossible by human observation. Conversely, the detection of noisy bearing, a leaky gland or cracked pipe is scarcely possible by automatic means. The balance between the possible and the necessary would be achieved in this case by combining automatic monitoring of all the likely fault conditions, with routine machinery space inspection say twice a day.

  12. 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...

  13. GEOTECHNICAL MODELS OF THE ARCH FOUNDATIONS OF THE MASLENICA BRIDGE

    Directory of Open Access Journals (Sweden)

    Tomislav Novosel

    1998-12-01

    Full Text Available On the site of Maslenica bridge structural tectonic, geophysical and engineering geological investigations, geotechnical drilling and laboratory sample testings were performed. Maslenica anticline is characteristic for the investigated area. It is built from the limestone of Cretaceous age. The anticline has an asymmetrical form with the vergence of the axial plane towards the north. Reverse faults with recent activities are present. The recent activity was proved by the discovery of the broken stalactite with the displacement of 11 cm, whose age is 36000 years. On quite young stalactites (stalagmites in the cave on the west side, no displacements were noticed. For the next period of 500 years the maximal possible displacement of 2.0 cm is foreseen. Smaller caves with the dimensions of 1 m3, were formed on the intersections of the reverse faults and greater joints. The canyon Novsko ždrilo was formed in the fault shear zone with tectonic transport to the right. According to the range of fracture, three characteristic types of rock masses were separated by engineering geological investigations. According to »Geomechanical classification« (RMR the first type corresponds to II to III class, while the second type corresponds to IV class, and the third type corresponds to V class (mylonite. Because of the complexity of the terrain structure, original engineering geological bases of design have not enabled the direct application of the analysis of stress-strain behaviour. Because of that the simplified geotechnical models were done. They enabled the projecting of foundation in the rock mass and renewal of poor quality rock mass.

  14. Nonlinear Stability Analysis of Long-Span Continuous Rigid Frame Bridge with Thin-Wall High Piers

    Institute of Scientific and Technical Information of China (English)

    Li Li; Peng Yuancheng; Long Xiaohong; Liao Ping

    2005-01-01

    By utilizing the current finite element program ANSYS, two types of finite element models (FEM), the beam model (BM) and shell model (SM), are established for the nonlinear stability analysis of a practical rigid frame bridge-Longtanhe Great Bridge. In these analyses, geometrical and material nonlinearities are simultaneously taken into account. For geometrical nonlinearity, updated Lagrangian formulations are adopted to derive the tangent stiffness matrix. In order to simulate the nonlinear behavior of the plastic hinge of the piers, the multi-lines spring element COMBIN39 is used in the SM while the bilinear rotational spring element COMBIN40 is employed in the BM. Numerical calculations show that satisfying results can be obtained in the stability analysis of the bridge when the double coupling nonlinearity effects are considered. In addition, the conclusion is significant for practical engineering.

  15. Digimarc MediaBridge: the birth of a consumer product from concept to commercial application

    Science.gov (United States)

    Perry, Burt; MacIntosh, Brian; Cushman, David

    2002-04-01

    This paper examines the issues encountered in the development and commercial deployment of a system based on digital watermarking technology. The paper provides an overview of the development of digital watermarking technology and the first applications to use the technology. It also looks at how we took the concept of digital watermarking as a communications channel within a digital environment and applied it to the physical print world to produce the Digimarc MediaBridge product. We describe the engineering tradeoffs that were made to balance competing requirements of watermark robustness, image quality, embedding process, detection speed and end user ease of use. Today, the Digimarc MediaBridge product links printed materials to auxiliary information about the content, via the Internet, to provide enhanced informational marketing, promotion, advertising and commerce opportunities.

  16. Application of discrete model in analyzes of built and tested composite bridge construction

    Directory of Open Access Journals (Sweden)

    Tarić Mirsad

    2011-01-01

    Full Text Available Designing problem and theoretical analyses of steel-concrete composite structures are especially emphasized in bridge engineering. Method of modelling composite constructions developed and established by standards had been improved by use of finite element method and modern software. By this paper authors wanted to point out the importance of adequate structure modelling assuming all features of steel-concrete bond, and comparing results of experimental research with results of software calculation based on FEM and calculation based on plane theory approach with certain simplifications. Because of research tests necessities the bridge was loaded with four heavy test vehicles. Results, which are represented graphically and numerically were essence for suggestion of giving advantages to area element discretization of composite section over the other one.

  17. Assessing and updating the reliability of concrete bridges subjected to spatial deterioration - principles and software implementation

    DEFF Research Database (Denmark)

    Schneider, Ronald; Fischer, Johannes; Bügler, Maximilian;

    2015-01-01

    . The overall system reliability is computed by means of a probabilistic structural model coupled with the deterioration model. Inspection data are included in the system reliability calculation through Bayesian updating on the basis of the DBN model. As proof of concept, a software prototype is...... developed to implement the method presented here. The software prototype is applied to a typical highway bridge and the influence of inspection information on the system deterioration state and the structural reliability is quantified taking into account the spatial correlation of the corrosion process....... This work is a step towards developing a software tool that can be used by engineering practitioners to perform reliability assessments of ageing concrete bridges and update their reliability with inspection and monitoring data....

  18. Stability Analysis of Long-Span Continuous Rigid Frame Bridge with Thin-Wall Pier

    Institute of Scientific and Technical Information of China (English)

    HE Bo; SHI Ya-nan; ZHU Hong-ping; GUO Wen-zeng; CHEN Yong

    2008-01-01

    During cantilever cast in construction of high-pier and large-span continuous rigid frame bridges, structural stability in the longest cantilevered stage is very important. Based on a practical design case of a large-span continuous rigid frame bridge in Wuhan, the longest span stability coefficient is calculated with linear-buckling and nonlinear-buckling methods, respectively. The influences of both geometrical nonlinearity and the dual nonlinearity of material and geometry are considered. Numerical results indicate that the nonlinear solution is necessary to stability analysis because linear buckling loads axe much higher than those of nonlinear buckling. Thus, the edge fiber yield criterion is more convenient and faster than ultimate loading criterion when estimating nonlinear stability of structure, and can be used easily in the initial engineering design.

  19. Investigations of effects of pilot injection with change in level of compression ratio in a common rail diesel engine

    OpenAIRE

    Gajarlawar Nilesh; Khetan Ajaykumar; Rao Gaddale Amba Prasad

    2013-01-01

    These day diesel engines are gaining lots of attention as prime movers for various source of transportation. It offers better drive ability, very good low end torque and importantly the lower CO2 emission. Diesel engines are bridging the gap between gasoline and diesel engines. Better noise vibration and harshness levels of gasoline engine are realized to great extent in diesel engine, thanks to common rail direct injection system. Common rail injection system is now well known entity. ...

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

    OpenAIRE

    Shrikant D. Bobade *, Dr. Valsson Varghese

    2016-01-01

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

  1. A modular steel freeway bridge: design concept and earthquake resistance.

    Science.gov (United States)

    Wattenburg, W H; McCallen, D B; Murray, R C

    1995-04-14

    A modular multilane steel freeway bridge has been constructed from surplus railroad flatcar decks. It can be erected on-site in a few days' time. It has been built and static-load tested for emergency freeway bridge repair. This inexpensive modular bridge may also have broad application around the world for low-cost bridges in areas where funds are limited. On the basis of static-load testing performed by the California Department of Transportation and computer dynamic analysis, this simple modular-design concept has the potential of providing a strong bridge that can withstand the severe aftershocks expected immediately after a major earthquake. PMID:17814794

  2. Renovation techniques for fatigue cracked orthotropic steel bridge decks

    OpenAIRE

    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-known example of fatigue cracks are those observed in the deck plate of the Van Brienenoord bascule bridge in 1997, at that time a 7 year old bridge. The renovation techniques are part of a proposed ma...

  3. Running Safety of Trains under Vessel-Bridge Collision

    OpenAIRE

    Yongle Li; Jiangtao Deng; Bin Wang; Chuanjin Yu

    2015-01-01

    To optimize the sensor placement of the health monitoring system, the dynamic behavior of the train-bridge system subjected to vessel-collision should be studied in detail firstly. This study thus focuses on the characteristics of a train-bridge system under vessel-bridge collision. The process of the vessel-bridge collision is simulated numerically with a reliable finite element model (FEM). The dynamic responses of a single car and a train crossing a cable-stayed bridge are calculated. It i...

  4. Dynamic Vehicle Impact for Safety Assessment of Bridges

    DEFF Research Database (Denmark)

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

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

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

    OpenAIRE

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

    1980-01-01

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

  6. Excitation of Arch and Suspension Bridges by Subwires

    Directory of Open Access Journals (Sweden)

    Noriaki Hiwatashi

    1993-01-01

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

  7. Excitation of Arch and Suspension Bridges by Subwires

    OpenAIRE

    Noriaki Hiwatashi; Yoji Mizuta; Yutaka Ishihara; Itio Hirai

    1993-01-01

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

  8. Violin Bridge Mobility Analysis under In-Plane Excitation

    OpenAIRE

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

    2013-01-01

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

  9. Global engineering

    International Nuclear Information System (INIS)

    This article considers the challenges posed by the declining orders in the plant engineering and contracting business in Germany, the need to remain competitive, and essential preconditions for mastering the challenge. The change in engineering approach is illustrated by the building of a methanol plant in Argentina by Lurgi with the basic engineering completed in Frankfurt with involvement of key personnel from Poland, completely engineered subsystems from a Brazilian subsupplier, and detailed engineering work in Frankfurt. The production of methanol from natural gas using the LurgiMega/Methanol process is used as a typical example of the industrial plant construction sector. The prerequisites for successful global engineering are listed, and error costs in plant construction, possible savings, and process intensification are discussed

  10. Cognitive Engineering

    OpenAIRE

    Wilson, Kyle M.; Helton, William S; Wiggins, Mark W.

    2013-01-01

    Cognitive engineering is the application of cognitive psychology and related disciplines to the design and operation of human–machine systems. Cognitive engineering combines both detailed and close study of the human worker in the actual work context and the study of the worker in more controlled environments. Cognitive engineering combines multiple methods and perspectives to achieve the goal of improved system performance. Given the origins of experimental psychology itself in issues regard...

  11. Software engineering

    CERN Document Server

    Sommerville, Ian

    2010-01-01

    The ninth edition of Software Engineering presents a broad perspective of software engineering, focusing on the processes and techniques fundamental to the creation of reliable, software systems. Increased coverage of agile methods and software reuse, along with coverage of 'traditional' plan-driven software engineering, gives readers the most up-to-date view of the field currently available. Practical case studies, a full set of easy-to-access supplements, and extensive web resources make teaching the course easier than ever.

  12. Engineering Knowledge

    OpenAIRE

    Nathan Rosenberg; W. Edward Steinmuller

    2012-01-01

    In historical perspective, both the nature of and arrangements for the generation of engineering knowledge have evolved over the past 150 years. We examine the historical development of the search for ‘useful knowledge’ in agriculture, aeronautics and chemical engineering during the first half of this period and the evolving balance between public and private initiative in supporting this search. During this period, the US was engaged in the engineering knowledge was often empirical, practice...

  13. Engineering Ethics

    OpenAIRE

    Didier, Christelle

    2010-01-01

    In this chapter, the author presents the research field called "engineering ethics" and analyses some ethical issues related to the engineering profession. Ce chapitre dresse un état des lieux du champ de recherche intitulé depuis les années 1980 "engineering ethics"en anglais. Il présente quelques enjeux éthiques que soulève le métier d'ingénieur.

  14. Information engineering

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, D.N.

    1997-02-01

    The Information Engineering thrust area develops information technology to support the programmatic needs of Lawrence Livermore National Laboratory`s Engineering Directorate. Progress in five programmatic areas are described in separate reports contained herein. These are entitled Three-dimensional Object Creation, Manipulation, and Transport, Zephyr:A Secure Internet-Based Process to Streamline Engineering Procurements, Subcarrier Multiplexing: Optical Network Demonstrations, Parallel Optical Interconnect Technology Demonstration, and Intelligent Automation Architecture.

  15. Reverse Engineering

    International Nuclear Information System (INIS)

    This book gives descriptions of reverse engineering with principle and structure of it, including what reverse engineering is, prospect and concerned laws, basic knowledge for reverse engineering like manual and back to user mode, using tool such as IDA installation, dependency walker and dump bin, network monitoring and universal extractor. It indicates analysis of malignant code, giving explanations of file virus, spy ware, an infection way of malignant code, anti debugging like Find window.

  16. Small-strain measurement in bridge connections using the digital image correlation (DIC) technique

    Science.gov (United States)

    Desai, Niranjan

    2016-04-01

    Structural health monitoring (SHM) is emerging as a vital tool to help civil engineers improve the safety, maintainability, and reliability of critical structures and assists infrastructure owners with timely information for the continued safe and economic operation of their structure. SHM involves implementing a strategy that identifies and characterizes damage or undesirable performance in engineering structures. The goal of this research project was to determine the smallest strains measurable using standard digital image correlation (DIC) based SHM equipment. This practical investigation that had strong ties to the industry was motivated by damage observed in a real-world bridge, which was initially undetected. Its early detection would have led to reduced repair costs. To accomplish the aforementioned goal, tests were performed on a laboratory specimen that replicated a steel beam-to-column connection of the concerned bridge, involving progressively loading it in a manner in which it was loaded in the actual bridge, while simultaneously measuring the strains that developed in it using the aforementioned DIC-based equipment and software. Under the controlled conditions in the laboratory, the minimum resolution of the state-of-the-art system used in this investigation was determined. Due to the challenges faced in making these small-strain measurements even under highly controlled laboratory conditions, it was concluded that it is currently unrealistic to use the existing DIC technology in a real-world situation to measure strains as small as those that would need to be measured to detect the onset of damage in bridge connections. More work needs to be done in this area.

  17. Traffic restrictions due to wind on the Fehmarn Belt bridge

    DEFF Research Database (Denmark)

    Dellwik, E.; Mann, Jakob; Rosenhagen, G.

    2006-01-01

    same as used in this report and here the comparison is satisfactory. We estimate that the prospective Fehmarn Belt bridge will be closed roughly 2% of the timefor light roadway vehicles (unloaded trucks and caravans), corresponding to 7 days per year. This is slightly less than for the Fehmarnsund...... Bridge. For the Great Belt bridge the corresponding actual fraction is 1.5%, despite the fact that this bridge usesstricter criteria. The most important difference between the bridges in this connection is their orientation with respect to the prevailing wind direction. If all the large bridges (Øresund......, Great Belt and Fehmarn Belt) used the same criteria the FehmarnBelt bridge would be closed approximately twice as much as the two others. The majority of these restrictions are likely to take place in the winter time and can be significantly reduced with wind screens....

  18. Research on Fairway Width Design in Curved Bridge Waters Channel

    Directory of Open Access Journals (Sweden)

    Chi Hong-Fu

    2013-01-01

    Full Text Available Bridge construction can promote economic development but if the bridge layout is unreasonable, it would hinder ship’s safety navigation in the bridge area. There is little reference for fairway width design about curved bridge channel in 〈〈inland river navigation standards〉〉 of China. In this study, a fairway width design method in curved bridge channel was put forward by taking into account the scope of turbulent scope of pier, ship’s track width, drifting distance due to wind, drifting distance due to current, the scope of ship’s safety field and additional width in curved channel. The fairway width design concept for curved bridge channel presented in this studyit may provide reference for bridge design and other fairway layout.

  19. 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.

  20. Bridge condition assessment using D numbers.

    Science.gov (United States)

    Deng, Xinyang; Hu, Yong; Deng, Yong

    2014-01-01

    Bridge condition assessment is a complex problem influenced by many factors. The uncertain environment increases more its complexity. Due to the uncertainty in the process of assessment, one of the key problems is the representation of assessment results. Though there exists many methods that can deal with uncertain information, however, they have more or less deficiencies. In this paper, a new representation of uncertain information, called D numbers, is presented. It extends the Dempster-Shafer theory. By using D numbers, a new method is developed for the bridge condition assessment. Compared to these existing methods, the proposed method is simpler and more effective. An illustrative case is given to show the effectiveness of the new method. PMID:24696639

  1. Monitoring of Bridge Dynamics by Radar Interferometry

    Directory of Open Access Journals (Sweden)

    Imrich Lipták

    2014-06-01

    Full Text Available The paper presents the possibilities of radar interferometry in dynamic deformationmonitoring of bridge structures. The technology is increasingly used for this purposethanks to high accuracy of realized measurements and possibility to measure deformationat multiple places of the monitored structure. High frequency of realized measurements (upto 200 Hz enables to determine the most of significant vibration modes of bridgedeformation. This technology is presented on real case study of the cycle bridge over theriver Morava near to Bratislava (Slovak republic. A spectral analysis of vibrationfrequencies is performed by discrete Fourier transformation. The evaluation of correctnessof the obtained deformation is performed by comparison of the results with accelerometerand total station measurements and FEM (Finite Element Method model of the structure.

  2. Tacoma Bridge Failure-- a Physical Model

    CERN Document Server

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

    2004-01-01

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

  3. Rehabilitation Engineering: What is Rehabilitation Engineering?

    Science.gov (United States)

    ... Parents/Teachers Resource Links for Students Glossary Rehabilitation Engineering What is rehabilitation engineering? What types of assistive ... the area of rehabilitation engineering? What is rehabilitation engineering? Source: Michael Goldfarb, Vanderbilt University Rehabilitation engineering is ...

  4. Propagation Engineering in Wireless Communications

    CERN Document Server

    Ghasemi, Abdollah; Ghasemi, Farshid

    2012-01-01

    Wireless communications has seen explosive growth in recent decades, in a realm that is both broad and rapidly expanding to include satellite services, navigational aids, remote sensing, telemetering, audio and video broadcasting, high-speed data communications, mobile radio systems and much more. Propagation Engineering in Wireless Communications deals with the basic principles of radiowaves propagation for frequency bands used in radio-communications, offering descriptions of new achievements and newly developed propagation models. The book bridges the gap between theoretical calculations and approaches, and applied procedures needed for advanced radio links design. The primary objective of this two-volume set is to demonstrate the fundamentals, and to introduce propagation phenomena and mechanisms that engineers are likely to encounter in the design and evaluation of radio links of a given type and operating frequency. Volume one covers basic principles, along with tropospheric and ionospheric propagation,...

  5. 高速公路桥梁加固后评价技术%Post Evaluation of Expressway Bridge Reinforcement Technology

    Institute of Scientific and Technical Information of China (English)

    孙卫民

    2014-01-01

    Based on the summarization of current post evaluation technology for highway bridge reinforce-ment project, the article discusses the basic concept, the reinforcement of bridge evaluation objective, con-tent of post evaluation for bridge reinforcement. Combined with the engineering example, the article points out the problems of bridge reinforcement post evaluation and the further research direction.%在对当前高速公路桥梁加固项目后评价技术进行总结分析的基础上,重点论述了桥梁加固后评价的基本概念、目的、内容,并结合具体工程实例指出了当前桥梁加固后评价存在的问题以及进一步的研究方向。

  6. Bridging the Divide between Science and Journalism

    OpenAIRE

    Marincola Francesco M; Van Eperen Laura; Strohm Jennifer

    2010-01-01

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

  7. Fatigue-Prone Details in Steel Bridges

    OpenAIRE

    Mohsen Heshmati; Mohammad Al-Emrani; Reza Haghani

    2012-01-01

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

  8. Stability of suspension bridges in lateral wind

    Czech Academy of Sciences Publication Activity Database

    Malík, Josef

    Praha: Institute of Computer Science AS CR, 2014 - (Bílková, H.; Rozložník, M.; Tichý, P.), s. 74-77 ISBN 978-80-87136-16-4. [SNA ’14. Seminar on Numerical Analysis. Nymburk (CZ), 27.01.2014-31.01.2014] R&D Projects: GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : stability * suspension bridges * torsional oscillations Subject RIV: BA - General Mathematics

  9. Bridge Inspections and Being an ERC

    OpenAIRE

    Hoernschemeyer, Keith; Miller, Jessica

    2015-01-01

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

  10. Does Myocardial Bridging Affect Coronary Hemodynamics?

    OpenAIRE

    Onur Sildiroglu; Ferhat Cuce; Zafer Isilak; Muzaffer Saglam; Mehmet Incedayi; Kemal Kara; Ersin Ozturk

    2013-01-01

    Objective. The aim of our study was to evaluate the relationship between a myocardial bridge (MB) and its effects over the coronary artery hemodynamics by using multislice computed tomography (MSCT). Material and Methods. A total of 412 patients examined with coronary computed tomography (CT) angiography were reviewed retrospectively for an MB of the left anterior descending (LAD) coronary artery. We evaluated the correlation between the depth of an MB and the degree of compression to the...

  11. Bridge Condition Assessment Using D Numbers

    OpenAIRE

    Xinyang Deng; Yong Hu; Yong Deng

    2014-01-01

    Bridge condition assessment is a complex problem influenced by many factors. The uncertain environment increases more its complexity. Due to the uncertainty in the process of assessment, one of the key problems is the representation of assessment results. Though there exists many methods that can deal with uncertain information, however, they have more or less deficiencies. In this paper, a new representation of uncertain information, called D numbers, is presented. It extends the Dempster-Sh...

  12. Ether bridge formation in loline alkaloid biosynthesis

    OpenAIRE

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

    2013-01-01

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

  13. Weakly prudent self-avoiding bridges

    OpenAIRE

    Bacher, Axel; Beaton, Nicholas,

    2014-01-01

    We define and enumerate a new class of self-avoiding walks on the square lattice, which we call \\emphweakly prudent bridges. Their definition is inspired by two previously-considered classes of self-avoiding walks, and can be viewed as a combination of those two models. We consider several methods for recursively generating these objects, each with its own advantages and disadvantages, and use these methods to solve the generating function, obtain very long series, and randomly generate walks...

  14. Legendrian framings for two-bridge links

    CERN Document Server

    Baader, Sebastian

    2009-01-01

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

  15. 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.

  16. Monitoring of Bridge Dynamics by Radar Interferometry

    OpenAIRE

    Imrich Lipták; Ján Erdélyi; Peter Kyrinovič; Alojz Kopáčik

    2014-01-01

    The paper presents the possibilities of radar interferometry in dynamic deformationmonitoring of bridge structures. The technology is increasingly used for this purposethanks to high accuracy of realized measurements and possibility to measure deformationat multiple places of the monitored structure. High frequency of realized measurements (upto 200 Hz) enables to determine the most of significant vibration modes of bridgedeformation. This technology is presented on real case study of the cyc...

  17. Torsional asymmetry in suspension bridge systems

    Czech Academy of Sciences Publication Activity Database

    Malík, Josef

    2015-01-01

    Roč. 60, č. 6 (2015), s. 677-701. ISSN 0862-7940 R&D Projects: GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : suspension bridge * Hamilton principle * vertical and torsional oscillation * uniqueness * existence Subject RIV: BA - General Mathematics Impact factor: 0.400, year: 2014 http://link.springer.com/article/10.1007%2Fs10492-015-0117-3

  18. Influence of Icing on Bridge Cable Aerodynamics

    DEFF Research Database (Denmark)

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

    2013-01-01

    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...... forces of different bridge cables types. The experiments were conducted in a wind tunnel facility capable amongst others to simulate incloud icing conditions....

  19. Liquid bridge simulations with OpenFOAM

    OpenAIRE

    Guirao Aguilar, Guillermo

    2011-01-01

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

  20. Bridging environmental mixtures and toxic effects

    OpenAIRE

    Allan, Sarah E.; Smith, Brian W.; Tanguay, Robert L.; Anderson, Kim A.

    2012-01-01

    BRIDGES is a bioanalytical tool that combines passive sampling with the embryonic zebrafish developmental toxicity bioassay to provide a quantitative measure of the toxicity of bioavailable complex mixtures. Passive sampling devices (PSDs), which sequester and concentrate bioavailable organic contaminants from the environment, were deployed in the Willamette and Columbia Rivers within and outside of the Portland Harbor Superfund site in Portland, Oregon. Six sampling events were conducted in ...

  1. Advances in Structural Control in Civil Engineering in China

    Directory of Open Access Journals (Sweden)

    Hongnan Li

    2010-01-01

    Full Text Available In the recent years, much attention has been paid to the research and development of structural control techniques with particular emphasis on alleviation of wind and seismic responses of buildings and bridges in China. Structural control in civil engineering has been developed from the concept into a workable technology and applied into practical engineering structures. The aim of this paper is to review a state of the art of researches and applications of structural control in civil engineering in China. It includes the passive control, active control, hybrid controland semiactive control. Finally, the possible future directions of structural control in civil engineering in China are presented.

  2. Bridge concrete deteriorating diagnosis by infrared thermography

    Science.gov (United States)

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

    2006-04-01

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

  3. Smart semiconductor bridge (SCB) igniter for explosives

    Science.gov (United States)

    Bickes, R. W., Jr.

    We have developed a silicon semiconductor bridge (SCB) igniter which, when driven with a low-energy current pulse, produces a plasma discharge that ignites explosive materials pressed against the bridge. Our experiments have demonstrated that SCB explosive devices function in a few tens of microseconds at one-tenth the input energy of hot-wire devices. Despite the low input energies for ignition, tests have revealed SCB devices to be explosively safe, passing electrostatic discharge (ESD) requirements and no-fire current levels. In fact, SCB devices have better no-fire characteristics than hot-wire devices, because of the intimate bridge contact with the underlying thermally conductive substrate. We have tested several different prototype explosive devices including pyrotechnic actuators, secondary explosive deflagration-to-detonation detonators and a primary explosive detonator. In addition, we have tested SCB actuators with breadboarded smart firing sets that will fire the SCB actuators only after transmission of a digital code, after a preset delay, or in a preprogrammed sequence. We have also tested an optical system that requires only a single fiber optic cable connecting the SCB device to a low power laser that both energizes the firing set and transmits a coded firing signal.

  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. Biomedical Engineering

    CERN Document Server

    Suh, Sang C; Tanik, Murat M

    2011-01-01

    Biomedical Engineering: Health Care Systems, Technology and Techniques is an edited volume with contributions from world experts. It provides readers with unique contributions related to current research and future healthcare systems. Practitioners and researchers focused on computer science, bioinformatics, engineering and medicine will find this book a valuable reference.

  6. Fluids engineering

    International Nuclear Information System (INIS)

    Fluids engineering has played an important role in many applications, from ancient flood control to the design of high-speed compact turbomachinery. New applications of fluids engineering, such as in high-technology materials processing, biotechnology, and advanced combustion systems, have kept up unwaining interest in the subject. More accurate and sophisticated computational and measurement techniques are also constantly being developed and refined. On a more fundamental level, nonlinear dynamics and chaotic behavior of fluid flow are no longer an intellectual curiosity and fluid engineers are increasingly interested in finding practical applications for these emerging sciences. Applications of fluid technology to new areas, as well as the need to improve the design and to enhance the flexibility and reliability of flow-related machines and devices will continue to spur interest in fluids engineering. The objectives of the present seminar were: to exchange current information on arts, science, and technology of fluids engineering; to promote scientific cooperation between the fluids engineering communities of both nations, and to provide an opportunity for the participants and their colleagues to explore possible joint research programs in topics of high priority and mutual interest to both countries. The Seminar provided an excellent forum for reviewing the current state and future needs of fluids engineering for the two nations. With the Seminar ear-marking the first formal scientific exchange between Korea and the United States in the area of fluids engineering, the scope was deliberately left broad and general

  7. Genetic Engineering

    Science.gov (United States)

    Phillips, John

    1973-01-01

    Presents a review of genetic engineering, in which the genotypes of plants and animals (including human genotypes) may be manipulated for the benefit of the human species. Discusses associated problems and solutions and provides an extensive bibliography of literature relating to genetic engineering. (JR)

  8. Corrosion Engineering.

    Science.gov (United States)

    White, Charles V.

    A description is provided for a Corrosion and Corrosion Control course offered in the Continuing Engineering Education Program at the General Motors Institute (GMI). GMI is a small cooperative engineering school of approximately 2,000 students who alternate between six-week periods of academic study and six weeks of related work experience in…

  9. Biosystems engineering

    OpenAIRE

    P. Ulger; E. Gonulol

    2015-01-01

    Higher agricultural education system has been getting multidiscipline as a result of the level oftechnology, recently. Biosystems Engineering has become popular in developed countries particularly afterelectronic and information technologies has been getting to be a part of agriculture and accompanied ofbiology. In this study definition of Biosystems Engineering discipline, working areas, research, publicationand job opportunities were discussed meticulously. Academic organization of Biosyste...

  10. Systems Engineering

    Science.gov (United States)

    Pellerano, Fernando

    2015-01-01

    This short course provides information on what systems engineering is and how the systems engineer guides requirements, interfaces with the discipline leads, and resolves technical issues. There are many system-wide issues that either impact or are impacted by the thermal subsystem. This course will introduce these issues and illustrate them with real life examples.

  11. Advances in Structural Control in Civil Engineering in China

    OpenAIRE

    Hongnan Li; Linsheng Huo

    2010-01-01

    In the recent years, much attention has been paid to the research and development of structural control techniques with particular emphasis on alleviation of wind and seismic responses of buildings and bridges in China. Structural control in civil engineering has been developed from the concept into a workable technology and applied into practical engineering structures. The aim of this paper is to review a state of the art of researches and applications of structural control in civil enginee...

  12. International Conference on Emerging Trends in Science, Engineering and Technology

    CERN Document Server

    Caroline, B; Jayanthi, J

    2012-01-01

    The present book is based on the research papers presented in the International Conference on Emerging Trends in Science, Engineering and Technology 2012, held at Tiruchirapalli, India. The papers presented bridges the gap between science, engineering and technology. This book covers a variety of topics, including mechanical, production, aeronautical, material science, energy, civil and environmental energy, scientific management, etc. The prime objective of the book is to fully integrate the scientific contributions from academicians, industrialists and research scholars.

  13. Multiscale computer modeling in biomechanics and biomedical engineering

    CERN Document Server

    2013-01-01

    This book reviews the state-of-the-art in multiscale computer modeling, in terms of both accomplishments and challenges. The information in the book is particularly useful for biomedical engineers, medical physicists and researchers in systems biology, mathematical biology, micro-biomechanics and biomaterials who are interested in how to bridge between traditional biomedical engineering work at the organ and tissue scales, and the newer arenas of cellular and molecular bioengineering.

  14. A building stone assessment of The Engine Shed, Stirling

    OpenAIRE

    Albornoz-Parra, L.J.; Tracey, E.A.; Gillespie, M.R.

    2014-01-01

    This report describes the outcomes of a project commissioned by Historic Scotland to identify suitable stone to use in forthcoming repairs to the building known as The Engine Shed, in Stirling, which will become Historic Scotland’s National Conservation Centre. A Building Stone Assessment has been conducted on three samples of sandstone supplied by Historic Scotland – two from different parts of The Engine Shed and one from the recently demolished Seaforth Place Bridge in Stirling – with a vi...

  15. A nature-inspired approach to reactor and catalysis engineering

    OpenAIRE

    Coppens, M-O

    2012-01-01

    Mechanisms used by biology to solve fundamental problems, such as those related to scalability, efficiency and robustness could guide the design of innovative solutions to similar challenges in chemical engineering. Complementing progress in bioinspired chemistry and materials science, we identify three methodologies as the backbone of nature-inspired reactor and catalysis engineering. First, biology often uses hierarchical networks to bridge scales and facilitate transport, leading to broadl...

  16. Engineering surveying

    CERN Document Server

    Schofield, W

    2001-01-01

    The aim of Engineering Surveying has always been to impart and develop a clear understanding of the basic topics of the subject. The author has fully revised the book to make it the most up-to-date and relevant textbook available on the subject.The book also contains the latest information on trigonometric levelling, total stations and one-person measuring systems. A new chapter on satellites ensures a firm grasp of this vitally important topic.The text covers engineering surveying modules for civil engineering students on degree courses and forms a reference for the engineering surveying module in land surveying courses. It will also prove to be a valuable reference for practitioners.* Simple clear introduction to surveying for engineers* Explains key techniques and methods* Details reading systems and satellite position fixing

  17. Emotional engineering

    CERN Document Server

    In an age of increasing complexity, diversification and change, customers expect services that cater to their needs and to their tastes. Emotional Engineering vol 2. describes how their expectations can be satisfied and managed throughout the product life cycle, if producers focus their attention more on emotion. Emotional engineering provides the means to integrate products to create a new social framework and develops services beyond product realization to create of value across a full lifetime.  14 chapters cover a wide range of topics that can be applied to product, process and industry development, with special attention paid to the increasing importance of sensing in the age of extensive and frequent changes, including: • Multisensory stimulation and user experience  • Physiological measurement • Tactile sensation • Emotional quality management • Mental model • Kansei engineering.   Emotional Engineering vol 2 builds on Dr Fukuda’s previous book, Emotional Engineering, and provides read...

  18. 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

  19. 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.

  20. 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.

  1. Structural behavior and design criteria for bridge strengthening by tied arch. Comparison with network arch bridges

    OpenAIRE

    Valenzuela, Matías A.; Casas Rius, Joan Ramon

    2013-01-01

    This study focuses on a new strengthening method of continuous bridges with several spans that present extensive damage in their foundation/piers due to scour and erosion. The method consists on the construction of a new upper steel arch with a network hanger's arrangement over the original deck with the aim to hang the existing deck to the new arch. The deck is acting as a tie in the new structural configuration. This allows to remove the damaged foundations/piers, deriving on an arch bridge...

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

    Institute of Scientific and Technical Information of China (English)

    杨光武

    2013-01-01

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

  3. The effect of ageing on the mechanical properties of the silk of the bridge spider Larinioides cornutus (Clerck, 1757)

    OpenAIRE

    Emiliano Lepore; Marco Isaia; Stefano Mammola; Nicola Pugno

    2016-01-01

    Spider silk is regarded as one of the best natural polymer fibers especially in terms of low density, high tensile strength and high elongation until breaking. Since only a few bio-engineering studies have been focused on spider silk ageing, we conducted nano-tensile tests on the vertical naturally spun silk fibers of the bridge spider Larinioides cornutus (Clerck, 1757) (Arachnida, Araneae) to evaluate changes in the mechanical properties of the silk (ultimate stress and strain, Young’s modu...

  4. Investigation of Strouhal numbers of iced cable models of cable-supported bridges with respect to angle of wind attack

    Czech Academy of Sciences Publication Activity Database

    Górski, P.; Tatara, M.; Pospíšil, Stanislav; Kuznetsov, Sergeii; Marušić, A.

    2015-01-01

    Roč. 112, 2-B (2015), s. 417-432. ISSN 1897-628X R&D Projects: GA MŠk(CZ) LO1219; GA MPO(CZ) FR-TI3/654 Keywords : bridge cable * ice accretion * Strouhal number * angle of attack * vortex shedding frequency Subject RIV: JN - Civil Engineering http://suw.biblos.pk.edu.pl/resources/i5/i6/i6/i8/i4/r56684/GorskiP_InvestigationsStrouhal.pdf

  5. Patterned transgene expression in multiple channel bridges after spinal cord injury

    OpenAIRE

    De Laporte, Laura; Huang, Alyssa; Ducommun, Melissa M.; Zelivyanska, Marina L.; Aviles, Misael O.; Adler, Andrew F.; Shea, Lonnie D.

    2010-01-01

    Patterning of gene delivery on sub-millimeter length scales within tissue engineering scaffolds can provide a fundamental technology to recreate the complex architectures of tissues. Surface-mediated delivery of lipoplexes mixed with fibronectin was investigated to pattern vectors within 250 µm channels on poly (lactide-co-glycolide) (PLG) bridges. Initial studies performed in vitro on PLG surfaces indicated that a DNA density of 0.07 µg/mm2 inside each channel with a weight ratio of DNA to f...

  6. A quasi-vehicle/bridge interaction model for high speed railways

    Czech Academy of Sciences Publication Activity Database

    Yau, J. D.; Frýba, Ladislav

    2015-01-01

    Roč. 31, č. 2 (2015), s. 217-225. ISSN 1727-7191 R&D Projects: GA ČR(CZ) GA103/08/1340 Grant ostatní: National Science Council in Taiwan(TW) NSC 102-2923-E-032-002-MY3 Institutional support: RVO:68378297 Keywords : high speed train * quasi-VBI model * resonance * vehicle-bridge interaction Subject RIV: JM - Building Engineering Impact factor: 0.580, year: 2014 http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9645645&fileId=S1727719114000896

  7. Assessment of damage identification algorithms on experimental and numerical bridge data

    Energy Technology Data Exchange (ETDEWEB)

    Jauregui, D.V.; Farrar, C.R.

    1995-12-01

    Over the past 25 years, the use of vibrational parameters for detecting damage in a structure has received considerable attention from the civil, aerospace, and mechanical engineering communities. The general idea is that changes in the structure`s physical properties, primarily stiffness, will alter the dynamic properties of the structure such as resonant frequencies and mode shapes. Properties such as the flexibility matrix, stiffness matrix, and mode shape curvature, which are obtained through manipulation of the modal parameters, have shown promise in localizing structural damage. In this paper, five techniques for damage assessment are demonstrated and compared using experimental and analytical data from a highway bridge.

  8. Problems connected with the application of lamella flanges in steel bridge construction

    Czech Academy of Sciences Publication Activity Database

    Křístek, V.; Kunrt, J.; Škaloud, Miroslav; Urushadze, Shota

    Vol. 769. Pfaffikon : Trans Tech Publications, 2015 - (Jendželovský, N.; Grmanová, A.; Ivánková, O.; Konečná, L.), s. 13-18 ISBN 978-3-03835-485-7. ISSN 1660-9336. [International Conference on New Trends in Statics and Dynamics of Buildings /12./. Bratislava (SK), 16.10.2014-17.10.2014] Institutional support: RVO:68378297 Keywords : breathing * cumulative damage * fatigue * lamella flanges * lifetime * steel bridges Subject RIV: JM - Building Engineering http://www.scientific.net/AMM.769.13

  9. Wheel-Rail Contact Forces in High-Speed Simply Supported Bridges at Resonance

    OpenAIRE

    Museros Romero, Pedro; Castillo-Linares, Alejandro; Alarcón Álvarez, Enrique

    2004-01-01

    The response of high-speed bridges at resonance, particularly under flexural vibrations, constitutes a subject of research for many scientists and engineers at the moment. The topic is of great interest because, as a matter of fact, such kind of behaviour is not unlikely to happen due to the elevated operating speeds of modern rains, which in many cases are equal to or even exceed 300 km/h ( [1,2]). The present paper addresses the subject of the evolution of the wheel-rail contact forces ...

  10. 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

  11. Engineering mathematics

    CERN Document Server

    Bird, John

    2014-01-01

    A practical introduction to the core mathematics required for engineering study and practiceNow in its seventh edition, Engineering Mathematics is an established textbook that has helped thousands of students to succeed in their exams.John Bird's approach is based on worked examples and interactive problems. This makes it ideal for students from a wide range of academic backgrounds as the student can work through the material at their own pace. Mathematical theories are explained in a straightforward manner, being supported by practical engineering examples and applications in order to ensure

  12. Engineering mathematics

    CERN Document Server

    Stroud, K A

    2013-01-01

    A groundbreaking and comprehensive reference that's been a bestseller since it first debuted in 1970, the new seventh edition of Engineering Mathematics has been thoroughly revised and expanded. Providing a broad mathematical survey, this innovative volume covers a full range of topics from the very basic to the advanced. Whether you're an engineer looking for a useful on-the-job reference or want to improve your mathematical skills, or you are a student who needs an in-depth self-study guide, Engineering Mathematics is sure to come in handy time and time again.

  13. Agent engineering

    CERN Document Server

    Liu, Jiming; Zhong, Ning; Wang, Patrick S P

    2001-01-01

    Agent engineering concerns the development of autonomous computational or physical entities capable of perceiving, reasoning, adapting, learning, cooperating and delegating in a dynamic environment. It is one of the most promising areas of research and development in information technology, computer science and engineering. This book addresses some of the key issues in agent engineering: What is meant by "autonomous agents"? How can we build agents with autonomy? What are the desirable capabilities of agents with respect to surviving (they will not die) and living (they will furthermore enjoy

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

    Science.gov (United States)

    Brown, Jeff; Fox, Terra

    2010-05-01

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

  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. Future Trends in Reliability-Based Bridge Management

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    Future bridge management systems will be based on simple stochastic models predicting the residual strength of structural elements. The current deterministic management systems are not effective in optimizing e.g. the life cycle cost of a bridge or a system of bridges. A number of important facto...... are so uncertain that they cannot be modelled satisfactorily by deterministic techniques. In recent years several researchers have studied stochastic modelling of e.g. deterioration, inspection, reliability, and repair but real applications are only reported in a few cases.......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...

  17. 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.

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

    DEFF Research Database (Denmark)

    Hansen, Henriette I.; Thoft-Christensen, Palle

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

  19. Natural engines

    International Nuclear Information System (INIS)

    'Taconis oscillations,' the oscillations of some variable stars, and a novel form of engine are all based on cycles that involve an intrinsically irreversible process and a broken thermodynamic symmetry

  20. Software engineering

    CERN Document Server

    Sommerville, Ian

    2016-01-01

    For courses in computer science and software engineering The Fundamental Practice of Software Engineering Software Engineering introduces readers to the overwhelmingly important subject of software programming and development. In the past few years, computer systems have come to dominate not just our technological growth, but the foundations of our world's major industries. This text seeks to lay out the fundamental concepts of this huge and continually growing subject area in a clear and comprehensive manner. The Tenth Edition contains new information that highlights various technological updates of recent years, providing readers with highly relevant and current information. Sommerville's experience in system dependability and systems engineering guides the text through a traditional plan-based approach that incorporates some novel agile methods. The text strives to teach the innovators of tomorrow how to create software that will make our world a better, safer, and more advanced place to live.

  1. Engineering personnel

    International Nuclear Information System (INIS)

    The expansion of nuclear power is taxing human, material, and capital resources in developed and developing countries. This paper explores the human resources as represented by employment, graduation statistics, and educational curricula for nuclear engineers. (E.C.B.)

  2. Harmonic engine

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, Charles L. (Livermore, CA)

    2009-10-20

    A high efficiency harmonic engine based on a resonantly reciprocating piston expander that extracts work from heat and pressurizes working fluid in a reciprocating piston compressor. The engine preferably includes harmonic oscillator valves capable of oscillating at a resonant frequency for controlling the flow of working fluid into and out of the expander, and also preferably includes a shunt line connecting an expansion chamber of the expander to a buffer chamber of the expander for minimizing pressure variations in the fluidic circuit of the engine. The engine is especially designed to operate with very high temperature input to the expander and very low temperature input to the compressor, to produce very high thermal conversion efficiency.

  3. 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.

  4. Bridge connection of quantum Hall elementary devices

    CERN Document Server

    Callegaro, Luca

    2013-01-01

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

  5. Research on Cascaded H-bridge SVG

    OpenAIRE

    Yannan Yu; Rongfeng Yang; Jichi Yan; Chang Qu

    2014-01-01

    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...

  6. Semiconductor bridge, SCB, ignition of energetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Bickes, R.W.; Grubelich, M.D.; Harris, S.M.; Merson, J.A.; Tarbell, W.W.

    1997-04-01

    Sandia National Laboratories` semiconductor bridge, SCB, is now being used for the ignition or initiation of a wide variety of exeoergic materials. Applications of this new technology arose because of a need at the system level to provide light weight, small volume and low energy explosive assemblies. Conventional bridgewire devices could not meet the stringent size, weight and energy requirements of our customers. We present an overview of SCB technology and the ignition characteristics for a number of energetic materials including primary and secondary explosives, pyrotechnics, thermites and intermetallics. We provide examples of systems designed to meet the modern requirements that sophisticated systems must satisfy in today`s market environments.

  7. 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. 

  8. Why the Water Bridge does not collapse

    CERN Document Server

    Aerov, Artem Anatolievich

    2010-01-01

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

  9. 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.

  10. Salt bridge as a gatekeeper against partial unfolding.

    Science.gov (United States)

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

    2016-05-01

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

  11. Abutments influence in the dynamic response of bridges

    OpenAIRE

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

    1996-01-01

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

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

    OpenAIRE

    So, Kevin K. L.; Moe M. S. Cheung; Zhang, Eric X. Q.

    2012-01-01

    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 ...

  13. Refined fatigue assessment of an existing steel bridge

    OpenAIRE

    Leander, John; Karoumi, Raid

    2015-01-01

    This paper treats the fatigue assessment of existing steel bridges for road traffic. It is focused on the estimation of the load effect. The deterministic assessment methods suggested in governing codes are reviewed and a comparison is performed against a reliability-based assessment. The latter method enables a consideration of reduced uncertainties from measurements of the real load effect. The Vårby Bridge in Sweden, a steel–concrete composite bridge south of Stockholm, is used as a case s...

  14. An innovative steel-concrete joint for integral abutment bridges

    OpenAIRE

    Bruno Briseghella; Tobia Zordan

    2015-01-01

    Integral abutment bridges are becoming rather common, due to the durability problems of bearings and expansion joints. At the same time, among short- and medium-span bridges, multi-beam steel-concrete composite deck with hot-rolled girder is an economical and interesting alternative to traditional pre-stressed concrete solutions. The two concepts can be linked together to design integral steel-concrete composite bridges with the benefits of two typologies. The most critical aspect for these b...

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

    OpenAIRE

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

    2010-01-01

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

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

    OpenAIRE

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

    2006-01-01

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

  17. PREVALENCE OF MYOCARDIAL BRIDGING BY CORONARY ANGIOGRAM: ANALYSIS AND SIGNIFICANCE

    OpenAIRE

    Prabhas Ranjan; Debasish; Divia Paul

    2015-01-01

    Out of nine hundred and eighty seven (987) coronary angiogram reports , in the present study we analysed the prevalence and distribution of bridging segments. The co - relation of these tunnelled segments with diseased and non - diseased coronary arteries and cardiac dominance were also assessed. Myocardial bridging was exclusively confined to LAD predominantly in the midsegmentG of nondiseased arteries in right dominant circulation. Although bridging provides...

  18. Abnormal ventricular repolarisation in association with myocardial bridging.

    OpenAIRE

    J.W. DEAN; Mills, P G

    1994-01-01

    Myocardial bridging causing systolic compression of epicardial coronary arteries may be an incidental finding at coronary arteriography. Bridging rarely causes myocardial ischaemia. A young man presented with chest pain and striking abnormalities of ventricular repolarisation that initially were treated as myocardial infarction. At cardiac catheterisation the coronary arteries were normal apart from the presence of a myocardial bridge affecting a major diagonal branch of the left anterior des...

  19. Project of industrial hall with a bridge crane

    OpenAIRE

    Ambrožič, Klemen

    2014-01-01

    In graduation thesis design of steel industrial hall with a bridge crane is performed. The first chapter contains technical report of the structure. Followed by the second chapter, which analyzes bridge crane and crane track. The influences of bridge crane are determined. These influences are considered for design of the crane track, fatigue check and displacements of the crane supporting structure. Fatigue check contains basic detail. The third chapter contains analysis of the hall supportin...

  20. THE MODERN DECISIONS ABOUT CONSTRUCTIONS OF BRIDGE FLOOR

    Directory of Open Access Journals (Sweden)

    I. D. Sakharova

    2010-03-01

    Full Text Available The paper is dealt with the changes introduced into the code of regulations «Bridges and pipes» developed as alternative to SNiP 2.05.03-84* related to the bridge floor of bridge structures: the possibility of refusing sidewalks, the change in road and sidewalk cross falls, the building of road pavement structures with the placement of asphalt concrete coating over waterproofing, and the drainage system construction.