Science.gov

Sample records for bridge design

  1. Virtual Bridge Design Challenge

    ERIC Educational Resources Information Center

    Mitts, Charles R.

    2013-01-01

    This design/problem-solving activity challenges students to design a replacement bridge for one that has been designated as either structurally deficient or functionally obsolete. The Aycock MS Technology/STEM Magnet Program Virtual Bridge Design Challenge is an authentic introduction to the engineering design process. It is a socially relevant…

  2. Virtual Bridge Design

    ERIC Educational Resources Information Center

    Bisogno, Janet; JeanPierre, Bobby

    2008-01-01

    The West Point Bridge Design (WPBD) building project engages students in project-based learning by giving them a real-life problem to solve. By using technology, students are able to become involved in solving problems that they normally would not encounter. Involvement with interactive websites, such as WPBD, assists students in using…

  3. Salt bridges: geometrically specific, designable interactions.

    PubMed

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

    2011-03-01

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

  4. Bridge strike reduction: optimising the design of markings.

    PubMed

    Horberry, Tim; Halliday, Mark; Gale, Alastair G

    2002-09-01

    Cases of high-sided vehicles striking low bridges is a large problem in many countries, especially the UK. This paper describes an experiment to evaluate a new design of markings for low bridges. A full size bridge was constructed which was capable of having its overhead clearance adjusted. Subjects sat in a truck cab as it drove towards the bridge and were asked to judge whether the vehicle could pass safely under the bridge. The main objective of the research was to determine whether marking the bridge with a newly devised experimental marking would result in more cautious decisions from subjects regarding whether or not the experimental bridge structure could be passed under safely compared with the currently used UK bridge marking standard. The results show that the type of bridge marking influenced the level of caution associated with decisions regarding bridge navigation, with the new marking design producing the most cautious decisions for the two different bridge heights used, at all distances away from the bridge structure. Additionally, the distance before the bridge at which decisions were given had an effect on the level of caution associated with decisions regarding bridge navigation (the closer to the bridge, the more cautious the decisions became, irrespective of the marking design). The implications of these results for reducing the number of bridge strikes are discussed.

  5. Teaching Elements and Principles of Bridge Design

    ERIC Educational Resources Information Center

    Beck, Charles

    2005-01-01

    Bridge construction is a popular classroom activity. However, the basic principles of tension, compression, and counterbalance are not always clearly represented and defined. The common materials used to construct model bridges, such as straws, toothpicks, Legos[TM], and building blocks, are often too flexible or stationary to demonstrate the…

  6. Optimum design of concrete cable-stayed bridges

    NASA Astrophysics Data System (ADS)

    Martins, Alberto M. B.; Simões, Luís M. C.; Negrão, João H. J. O.

    2016-05-01

    The design of cable-stayed bridges involves a significant number of design variables and design objectives. The concrete cable-stayed bridge optimization is formulated here as a multi-objective optimization problem with objectives of minimum cost, minimum deflections and minimum stresses. A numerical method is developed to obtain the optimum design of such structures. This numerical method includes: structural analysis, sensitivity analysis and optimization. The structural analysis accounts for all the relevant effects (concrete time-dependent effects, construction stages and geometrical nonlinear effects). The structural response to changes in the design variables is achieved by a discrete direct sensitivity analysis procedure, and an entropy-based approach was used for structural optimization. The features and applicability of the proposed method are demonstrated by numerical examples concerning the optimization of a real-sized concrete cable-stayed bridge.

  7. Bridging CALL & HCI: Input from Participatory Design

    ERIC Educational Resources Information Center

    Cardenas-Claros, Monica S.; Gruba, Paul A.

    2010-01-01

    Participatory design (PD), or the collaboration between software engineers and end users throughout the design process, may help improve CALL design practices. In this case study, four ESL learners, a software designer, and a language teacher created and evaluated a series of paper prototypes concerning help options in computer-based second…

  8. A Bridge for Accelerating Materials by Design

    DOE PAGES

    Sumpter, Bobby G.; Vasudevan, Rama K.; Potok, Thomas E.; ...

    2015-11-25

    Recent technical advances in the area of nanoscale imaging, spectroscopy, and scattering/diffraction have led to unprecedented capabilities for investigating materials structural, dynamical and functional characteristics. In addition, recent advances in computational algorithms and computer capacities that are orders of magnitude larger/faster have enabled large-scale simulations of materials properties starting with nothing but the identity of the atomic species and the basic principles of quantum- and statistical-mechanics and thermodynamics. Along with these advances, an explosion of high-resolution data has emerged. This confluence of capabilities and rise of big data offer grand opportunities for advancing materials sciences but also introduce several challenges.more » In this editorial we identify challenges impeding progress towards advancing materials by design (e.g., the design/discovery of materials with improved properties/performance), possible solutions, and provide examples of scientific issues that can be addressed by using a tightly integrated approach where theory and experiments are linked through big-deep data.« less

  9. A Bridge for Accelerating Materials by Design

    SciTech Connect

    Sumpter, Bobby G.; Vasudevan, Rama K.; Potok, Thomas E.; Kalinin, Sergei V.

    2015-11-25

    Recent technical advances in the area of nanoscale imaging, spectroscopy, and scattering/diffraction have led to unprecedented capabilities for investigating materials structural, dynamical and functional characteristics. In addition, recent advances in computational algorithms and computer capacities that are orders of magnitude larger/faster have enabled large-scale simulations of materials properties starting with nothing but the identity of the atomic species and the basic principles of quantum- and statistical-mechanics and thermodynamics. Along with these advances, an explosion of high-resolution data has emerged. This confluence of capabilities and rise of big data offer grand opportunities for advancing materials sciences but also introduce several challenges. In this editorial we identify challenges impeding progress towards advancing materials by design (e.g., the design/discovery of materials with improved properties/performance), possible solutions, and provide examples of scientific issues that can be addressed by using a tightly integrated approach where theory and experiments are linked through big-deep data.

  10. A bridge for accelerating materials by design

    NASA Astrophysics Data System (ADS)

    Sumpter, Bobby G.; Vasudevan, Rama K.; Potok, Thomas; Kalinin, Sergei V.

    2015-11-01

    Recent technical advances in the area of nanoscale imaging, spectroscopy and scattering/diffraction have led to unprecedented capabilities for investigating materials structural, dynamical and functional characteristics. In addition, recent advances in computational algorithms and computer capacities that are orders of magnitude larger/faster have enabled large-scale simulations of materials properties starting with nothing but the identity of the atomic species and the basic principles of quantum and statistical mechanics and thermodynamics. Along with these advances, an explosion of high-resolution data has emerged. This confluence of capabilities and rise of big data offer grand opportunities for advancing materials sciences but also introduce several challenges. In this perspective, we identify challenges impeding progress towards advancing materials by design (e.g., the design/discovery of materials with improved properties/performance), possible solutions and provide examples of scientific issues that can be addressed using a tightly integrated approach where theory and experiments are linked through big-deep data.

  11. Effects of salt bridges on protein structure and design.

    PubMed Central

    Sindelar, C. V.; Hendsch, Z. S.; Tidor, B.

    1998-01-01

    Theoretical calculations (Hendsch ZS & Tidor B, 1994, Protein Sci 3:211-226) and experiments (Waldburger CD et al., 1995, Nat Struct Biol 2:122-128; Wimley WC et al., 1996, Proc Natl Acad Sci USA 93:2985-2990) suggest that hydrophobic interactions are more stabilizing than salt bridges in protein folding. The lack of apparent stability benefit for many salt bridges requires an alternative explanation for their occurrence within proteins. To examine the effect of salt bridges on protein structure and stability in more detail, we have developed an energy function for simple cubic lattice polymers based on continuum electrostatic calculations of a representative selection of salt bridges found in known protein crystal structures. There are only three types of residues in the model, with charges of -1, 0, or + 1. We have exhaustively enumerated conformational space and significant regions of sequence space for three-dimensional cubic lattice polymers of length 16. The results demonstrate that, while the more highly charged sequences are less stable, the loss of stability is accompanied by a substantial reduction in the degeneracy of the lowest-energy state. Moreover, the reduction in degeneracy is greater due to charges that pair than for lone charges that remain relatively exposed to solvent. We have also explored and illustrated the use of ion-pairing strategies for rational structural design using model lattice studies. PMID:9761471

  12. Towards establishing practical multi-hazard bridge design limit states

    NASA Astrophysics Data System (ADS)

    Liang, Zach; Lee, George C.

    2013-09-01

    In the U.S., the current Load and Resistance Factor Design (LRFD) Specifications for highway bridges is a reliability-based formulation that considers failure probabilities of bridge components due to the actions of typical dead load and frequent vehicular loads. Various extreme load effects, such as earthquake and vessel collision, are not considered on the same reliability-based platform. Since these extreme loads are time variables, combining them with frequent, nonextreme loads is a significant challenge. The number of design limit state equations based on these failure probabilities can be unrealistically large and unnecessary from the view point of practical applications. Based on the opinion of AASHTO State Bridge Engineers, many load combinations are insignificant in their states. This paper describes the formulation of a criterion to include only the necessary load combinations to establish the design limit states. This criterion is established by examining the total failure probabilities for all possible time-invariant and time varying load combinations and breaking them down into partial terms. Then, important load combinations can be readily determined quantitatively.

  13. Vulnerability analysis for design of bridge health monitoring system

    NASA Astrophysics Data System (ADS)

    Sun, L. M.; Yu, G.

    2010-03-01

    The recent engineering implementation of health monitoring system for long span bridges show difficulties for precisely assessing structural physical condition as well as for accurately alarming on structural damages, although hundreds of sensors were installed on a structure and a great amount of data were collected from the monitoring system. The allocation of sensors and the alarming algorithm are still two of the most important tasks to be considered when designing the structural health monitoring system. Vulnerability, in its original meaning, is the system susceptibility to local damage. For a structural system, the vulnerability can thus be regarded as structural performance susceptibility to local damage of structure. The purpose of this study is to propose concepts and methods of structural vulnerability for determining monitoring components which are more vulnerable than others and the corresponding warning threshold once the damages occur. The structural vulnerability performances to various damage scenarios depend upon structural geometrical topology, loading pattern on the structure and the degradation of component performance. A two-parameters structural vulnerability evaluation method is proposed in this paper. The parameters are the damage consequence and the relative magnitude of the damage scenarios to the structural system, respectively. Structural vulnerability to various damage scenarios can be regarded as the tradeoff between the two parameters. Based on the results of structural vulnerability analysis, the limited structural information from health monitoring can be utilized efficiently. The approach of the design of bridge health monitoring system is illustrated for a cable-stayed bridge.

  14. 23 CFR 661.53 - What standards should be used for bridge design?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 23 Highways 1 2013-04-01 2013-04-01 false What standards should be used for bridge design? 661.53... TRAFFIC OPERATIONS INDIAN RESERVATION ROAD BRIDGE PROGRAM § 661.53 What standards should be used for bridge design? (a) Replacement—A replacement structure must meet the current geometric, construction...

  15. 23 CFR 661.53 - What standards should be used for bridge design?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 23 Highways 1 2014-04-01 2014-04-01 false What standards should be used for bridge design? 661.53... TRAFFIC OPERATIONS INDIAN RESERVATION ROAD BRIDGE PROGRAM § 661.53 What standards should be used for bridge design? (a) Replacement—A replacement structure must meet the current geometric, construction...

  16. 23 CFR 661.53 - What standards should be used for bridge design?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... TRAFFIC OPERATIONS INDIAN RESERVATION ROAD BRIDGE PROGRAM § 661.53 What standards should be used for bridge design? (a) Replacement—A replacement structure must meet the current geometric, construction and... 23 Highways 1 2010-04-01 2010-04-01 false What standards should be used for bridge design?...

  17. 23 CFR 661.53 - What standards should be used for bridge design?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... TRAFFIC OPERATIONS INDIAN RESERVATION ROAD BRIDGE PROGRAM § 661.53 What standards should be used for bridge design? (a) Replacement—A replacement structure must meet the current geometric, construction and... 23 Highways 1 2012-04-01 2012-04-01 false What standards should be used for bridge design?...

  18. 23 CFR 661.53 - What standards should be used for bridge design?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... TRAFFIC OPERATIONS INDIAN RESERVATION ROAD BRIDGE PROGRAM § 661.53 What standards should be used for bridge design? (a) Replacement—A replacement structure must meet the current geometric, construction and... 23 Highways 1 2011-04-01 2011-04-01 false What standards should be used for bridge design?...

  19. Photoelastic stress analysis in perforated (Rochette) resin bonded bridge design.

    PubMed

    Ziada, H M; Orr, J F; Benington, I C

    2000-05-01

    Rochette described the perforated cast metal bonded design for splinting periodontally compromised teeth. The design was later used for replacing missing teeth. The main causes of failure of the perforated (Rochette) type design were attributed to inappropriate case selection and erosion of the composite from perforations. The aim of this study was to analyse the effect of stress magnitude and direction on failure of perforated resin bonded bridges (RBBs). The objective was to compare stress magnitudes in this design with those reported on the non-perforated RBBs. Photoelastic modelling materials were selected to represent the relative stiffnesses of a posterior mandibular and an anterior maxillary perforated (Rochette) type design. The sizes of the models were scaled to x 2.5 in order to enhance visual analysis of the stress patterns. Stress magnitudes were quantified from isochromatic fringes and stress directions were evaluated from stress trajectories. These revealed a high-stress concentration around the perforations, particularly for those at the proximo-lingual/palatal (connector) areas. This experimental study revealed that the main reason for failure of Rochette designs is deformation at the perforations.

  20. Next generation seismic fragility curves for California bridges incorporating the evolution in seismic design philosophy

    NASA Astrophysics Data System (ADS)

    Ramanathan, Karthik Narayan

    Quantitative and qualitative assessment of the seismic risk to highway bridges is crucial in pre-earthquake planning, and post-earthquake response of transportation systems. Such assessments provide valuable knowledge about a number of principal effects of earthquakes such as traffic disruption of the overall highway system, impact on the regions’ economy and post-earthquake response and recovery, and more recently serve as measures to quantify resilience. Unlike previous work, this study captures unique bridge design attributes specific to California bridge classes along with their evolution over three significant design eras, separated by the historic 1971 San Fernando and 1989 Loma Prieta earthquakes (these events affected changes in bridge seismic design philosophy). This research developed next-generation fragility curves for four multispan concrete bridge classes by synthesizing new knowledge and emerging modeling capabilities, and by closely coordinating new and ongoing national research initiatives with expertise from bridge designers. A multi-phase framework was developed for generating fragility curves, which provides decision makers with essential tools for emergency response, design, planning, policy support, and maximizing investments in bridge retrofit. This framework encompasses generational changes in bridge design and construction details. Parameterized high-fidelity three-dimensional nonlinear analytical models are developed for the portfolios of bridge classes within different design eras. These models incorporate a wide range of geometric and material uncertainties, and their responses are characterized under seismic loadings. Fragility curves were then developed considering the vulnerability of multiple components and thereby help to quantify the performance of highway bridge networks and to study the impact of seismic design principles on the performance within a bridge class. This not only leads to the development of fragility relations

  1. Engineering design processes in seventh-grade classrooms: bridging the engineering education gap

    NASA Astrophysics Data System (ADS)

    English, Lyn D.; Hudson, Peter B.; Dawes, Les

    2012-10-01

    This paper reports on some findings from the first year of a three-year longitudinal study, in which seventh- to ninth-graders were introduced to engineering education. Specifically, the paper addresses students' responses to an initial design activity involving bridge construction, which was implemented at the end of seventh grade. This paper also addresses how students created their bridge designs and applied these in their bridge constructions; their reflections on their designs; their reflections on why the bridge failed to support increased weights during the testing process; and their suggestions on ways in which they would improve their bridge designs. The present findings include identification of six, increasingly sophisticated levels of illustrated bridge designs, with designs improving between the classroom and homework activities of two focus groups of students. Students' responses to the classroom activity revealed a number of iterative design processes, where the problem goals, including constraints, served as monitoring factors for students' generation of ideas, design thinking and construction of an effective bridge.

  2. Design and implementation of the ESL compact range underhung bridge crane

    NASA Technical Reports Server (NTRS)

    Shamansky, H. T.; Dominek, A. K.; Burnside, W. D.

    1987-01-01

    As the indoor compact range technology has continued to increase, the need to handle larger and heavier targets has also increased. This need for target lifting and handling prompted the feasibility study of the use of an underhung bridge crane to be installed in the ESL (ElectroScience Laboratory, Ohio State University) compact range. This report documents both the design of the underhung bridge crane that was installed and the implementation of the design in the actual installation of the crane.

  3. Causeway and bridge design to reduce roadway contaminant runoff to a saltmarsh ecosystem

    SciTech Connect

    Leitman, P.A.; Ross, P.E.

    1995-12-31

    At the insistence of the local fishermen and landowners the Isle of Palms connector (Charleston, South Carolina) was built with a unique set of environmental safeguards so that the saltmarsh beneath the bridge would remain uncontaminated. This study evaluates the effectiveness of the bridge, in order to judge the suitability of the design for other areas. A two kilometer causeway over the marsh has catch pans to hold runoff, except that a heavy rain causes the pans to overflow. A one kilometer span over the Intracoastal waterway has pipes that redirect the runoff into gravel lined spoils. The bridge was monitored quarterly from January to December 1994. Extensive testing was performed during October 1994 to compare sites around the bridge and within the watershed to a pristine site and a to highly contaminated site. Sediment and water samples were tested with the Microtox{reg_sign} bioluminescence assay and a Latuca sativa (lettuce) seed germination and growth assay. Sediment samples were also tested with a Mercenaria mercenaria (littleneck clam) growth bioassay. Benthic community structure was analyzed for sites around the bridge. While very few statistically significant instances of toxicity were found, there are some trends that make it apparent that the bridge runoff may have some effects. There is no apparent accumulation of toxic contaminants from the pan overflow in sediments beneath the bridge, and this bridge design should ameliorate the effects of bridge runoff in almost any area. Future research using chemical analysis of the fate and transport of contaminants within the bridge and the surrounding area is suggested.

  4. Protein thermal stability enhancement by designing salt bridges: a combined computational and experimental study.

    PubMed

    Lee, Chi-Wen; Wang, Hsiu-Jung; Hwang, Jenn-Kang; Tseng, Ching-Ping

    2014-01-01

    Protein thermal stability is an important factor considered in medical and industrial applications. Many structural characteristics related to protein thermal stability have been elucidated, and increasing salt bridges is considered as one of the most efficient strategies to increase protein thermal stability. However, the accurate simulation of salt bridges remains difficult. In this study, a novel method for salt-bridge design was proposed based on the statistical analysis of 10,556 surface salt bridges on 6,493 X-ray protein structures. These salt bridges were first categorized based on pairing residues, secondary structure locations, and Cα-Cα distances. Pairing preferences generalized from statistical analysis were used to construct a salt-bridge pair index and utilized in a weighted electrostatic attraction model to find the effective pairings for designing salt bridges. The model was also coupled with B-factor, weighted contact number, relative solvent accessibility, and conservation prescreening to determine the residues appropriate for the thermal adaptive design of salt bridges. According to our method, eight putative salt-bridges were designed on a mesophilic β-glucosidase and 24 variants were constructed to verify the predictions. Six putative salt-bridges leaded to the increase of the enzyme thermal stability. A significant increase in melting temperature of 8.8, 4.8, 3.7, 1.3, 1.2, and 0.7°C of the putative salt-bridges N437K-D49, E96R-D28, E96K-D28, S440K-E70, T231K-D388, and Q277E-D282 was detected, respectively. Reversing the polarity of T231K-D388 to T231D-D388K resulted in a further increase in melting temperatures by 3.6°C, which may be caused by the transformation of an intra-subunit electrostatic interaction into an inter-subunit one depending on the local environment. The combination of the thermostable variants (N437K, E96R, T231D and D388K) generated a melting temperature increase of 15.7°C. Thus, this study demonstrated a novel

  5. An evaluation of the impact of an example of thermal bridging in buildings and a design alternative

    NASA Astrophysics Data System (ADS)

    Kleinfeld, Jack M.

    2012-06-01

    Thermal Bridges act as short circuits for energy flow between conditioned interior space and the outside environment. They readily show up in infrared imaging under appropriate conditions. An example of a thermal bridge in a standard building detail and an alternate design are analyzed to predict the energy impact of the bridge and of removing it. The analysis also provides guidance on whether infrared imaging can detect the thermal bridge.

  6. Optimum design of bridges with superelastic-friction base isolators against near-field earthquakes

    NASA Astrophysics Data System (ADS)

    Ozbulut, Osman E.; Hurlebaus, Stefan

    2010-04-01

    The seismic response of a multi-span continuous bridge isolated with novel superelastic-friction base isolator (S-FBI) is investigated under near-field earthquakes. The isolation system consists of a flat steel-Teflon sliding bearing and a superelastic NiTi shape memory alloy (SMA) device. Sliding bearings limit the maximum seismic forces transmitted to the superstructure to a certain value that is a function of friction coefficient of sliding interface. Superelastic SMA device provides restoring capability to the isolation system together with additional damping characteristics. The key design parameters of an S-FBI system are the natural period of the isolated, yielding displacement of SMA device, and the friction coefficient of the sliding bearings. The goal of this study is to obtain optimal values for each design parameter by performing sensitivity analyses of the isolated bridge. First, a three-span continuous bridge is modeled as a two-degrees-of-freedom with S-FBI system. A neuro-fuzzy model is used to capture rate-dependent nonlinear behavior of SMA device. A time-dependent method which employs wavelets to adjust accelerograms to match a target response spectrum with minimum changes on the other characteristics of ground motions is used to generate ground motions used in the simulations. Then, a set of nonlinear time history analyses of the isolated bridge is performed. The variation of the peak response quantities of the isolated bridge is shown as a function of design parameters. Also, the influence of temperature variations on the effectiveness of S-FBI system is evaluated. The results show that the optimum design of the isolated bridge with S-FBI system can be achieved by a judicious specification of design parameters.

  7. Design for minimizing fracture risk of all-ceramic cantilever dental bridge.

    PubMed

    Zhang, Zhongpu; Zhou, Shiwei; Li, Eric; Li, Wei; Swain, Michael V; Li, Qing

    2015-01-01

    Minimization of the peak stresses and fracture incidence induced by mastication function is considered critical in design of all-ceramic dental restorations, especially for cantilever fixed partial dentures (FPDs). The focus of this study is on developing a mechanically-sound optimal design for all-ceramic cantilever dental bridge in a posterior region. The topology optimization procedure in association with Extended Finite Element Method (XFEM) is implemented here to search for the best possible distribution of porcelain and zirconia materials in the bridge structure. The designs with different volume fractions of zirconia are considered. The results show that this new methodology is capable of improving FPD design by minimizing incidence of crack in comparison with the initial design. Potentially, it provides dental technicians with a new design tool to develop mechanically sound cantilever fixed partial dentures for more complicated clinical situation.

  8. Building Bridges within Mathematics Education: Teaching, Research, and Instructional Design

    ERIC Educational Resources Information Center

    Magidson, Susan

    2005-01-01

    Within mathematics education, classroom teachers, educational researchers, and instructional designers share the common goals of understanding and improving the teaching and learning of mathematics. Teachers work to help students learn; researchers study how people learn and teach mathematics; and designers develop instructional materials to…

  9. The Belizean Bridge Activity.

    ERIC Educational Resources Information Center

    Murfin, Brian

    2000-01-01

    Describes the famous swing bridge in Belize. Students build bridges from a variety of materials and answer the questions, What are different types of bridges?, How do bridges work?, How can you tell if a bridge design will be safe?, and What is the best way to build a bridge over a river while still allowing boat traffic? (SAH)

  10. Learning Axes and Bridging Tools in a Technology-Based Design for Statistics

    ERIC Educational Resources Information Center

    Abrahamson, Dor; Wilensky, Uri

    2007-01-01

    We introduce a design-based research framework, "learning axes and bridging tools," and demonstrate its application in the preparation and study of an implementation of a middle-school experimental computer-based unit on probability and statistics, "ProbLab" (Probability Laboratory, Abrahamson and Wilensky 2002 [Abrahamson, D., & Wilensky, U.…

  11. An Ontology-Based Framework for Bridging Learning Design and Learning Content

    ERIC Educational Resources Information Center

    Knight, Colin, Gasevic, Dragan; Richards, Griff

    2006-01-01

    The paper describes an ontology-based framework for bridging learning design and learning object content. In present solutions, researchers have proposed conceptual models and developed tools for both of those subjects, but without detailed discussions of how they can be used together. In this paper we advocate the use of ontologies to explicitly…

  12. Engineering Design Processes in Seventh-Grade Classrooms: Bridging the Engineering Education Gap

    ERIC Educational Resources Information Center

    English, Lyn D.; Hudson, Peter B.; Dawes, Les

    2012-01-01

    This paper reports on some findings from the first year of a three-year longitudinal study, in which seventh- to ninth-graders were introduced to engineering education. Specifically, the paper addresses students' responses to an initial design activity involving bridge construction, which was implemented at the end of seventh grade. This paper…

  13. Monogroove heat pipe design: Insulated liquid channel with bridging wick

    NASA Technical Reports Server (NTRS)

    Alario, J. P.; Brown, R. F.; Kosson, R. L. (Inventor)

    1985-01-01

    A screen mesh artery supported concentrically within the evaporator section of a heat pipe liquid channel retains liquid in the channel. Continued and uniform liquid feed to the heat pipe evaporation section (20) during periods of excessive heat transfer is assured. The overall design provides high evaporation and condensation film coefficients for the working fluid by means of the circumferential grooves in the walls of the vapor channel, while not interfering with the overall heat transport capability of the axial groove. The design has particular utility in zero-g environments.

  14. Affordability Engineering: Bridging the Gap Between Design and Cost

    NASA Technical Reports Server (NTRS)

    Reeves, J. D.; DePasquale, Dominic; Lim, Evan

    2010-01-01

    Affordability is a commonly used term that takes on numerous meanings depending on the context used. Within conceptual design of complex systems, the term generally implies comparisons between expected costs and expected resources. This characterization is largely correct, but does not convey the many nuances and considerations that are frequently misunderstood and underappreciated. In the most fundamental sense, affordability and cost directly relate to engineering and programmatic decisions made throughout development programs. Systems engineering texts point out that there is a temporal aspect to this relationship, for decisions made earlier in a program dictate design implications much more so than those made during latter phases. This paper explores affordability engineering and its many sub-disciplines by discussing how it can be considered an additional engineering discipline to be balanced throughout the systems engineering and systems analysis processes. Example methods of multidisciplinary design analysis with affordability as a key driver will be discussed, as will example methods of data visualization, probabilistic analysis, and other ways of relating design decisions to affordability results.

  15. Design, Development, and Testing of Advanced Bridge Structures

    DTIC Science & Technology

    1993-12-23

    VA 22060-5606 Under C ntract No. l )AAK70-90-C-(H)19~ Martin Marietta Technologies, Inc. Martin Marietta Laboratories 14.50 South Rolli’n, Road...34.• DTIC S- l , I. - AvTI h- rn? EXECUTIVE SUMMARY Adhesive bonding has theoretical advantages for the construction of lightweight structures, such as...100 Figure 3.33. Computer optimized joint design for an aluminum tubular lap joint with overlap ratio ( L /1𔃺) = 4.1

  16. Bridging Translation by Improving Preclinical Study Design in AKI.

    PubMed

    de Caestecker, Mark; Humphreys, Ben D; Liu, Kathleen D; Fissell, William H; Cerda, Jorge; Nolin, Thomas D; Askenazi, David; Mour, Girish; Harrell, Frank E; Pullen, Nick; Okusa, Mark D; Faubel, Sarah

    2015-12-01

    Despite extensive research, no therapeutic interventions have been shown to prevent AKI, accelerate recovery of AKI, or reduce progression of AKI to CKD in patients. This failure in translation has led investigators to speculate that the animal models being used do not predict therapeutic responses in humans. Although this issue continues to be debated, an important concern that has not been addressed is whether improvements in preclinical study design can be identified that might also increase the likelihood of translating basic AKI research into clinical practice using the current models. In this review, we have taken an evidence-based approach to identify common weaknesses in study design and reporting in preclinical AKI research that may contribute to the poor translatability of the findings. We focused on use of N-acetylcysteine or sodium bicarbonate for the prevention of contrast-induced AKI and use of erythropoietin for the prevention of AKI, two therapeutic approaches that have been extensively studied in clinical trials. On the basis of our findings, we identified five areas for improvement in preclinical study design and reporting. These suggested and preliminary guidelines may help improve the quality of preclinical research for AKI drug development.

  17. Bridging Translation by Improving Preclinical Study Design in AKI

    PubMed Central

    Humphreys, Ben D.; Liu, Kathleen D.; Fissell, William H.; Cerda, Jorge; Nolin, Thomas D.; Askenazi, David; Mour, Girish; Harrell, Frank E.; Pullen, Nick; Okusa, Mark D.

    2015-01-01

    Despite extensive research, no therapeutic interventions have been shown to prevent AKI, accelerate recovery of AKI, or reduce progression of AKI to CKD in patients. This failure in translation has led investigators to speculate that the animal models being used do not predict therapeutic responses in humans. Although this issue continues to be debated, an important concern that has not been addressed is whether improvements in preclinical study design can be identified that might also increase the likelihood of translating basic AKI research into clinical practice using the current models. In this review, we have taken an evidence-based approach to identify common weaknesses in study design and reporting in preclinical AKI research that may contribute to the poor translatability of the findings. We focused on use of N-acetylcysteine or sodium bicarbonate for the prevention of contrast-induced AKI and use of erythropoietin for the prevention of AKI, two therapeutic approaches that have been extensively studied in clinical trials. On the basis of our findings, we identified five areas for improvement in preclinical study design and reporting. These suggested and preliminary guidelines may help improve the quality of preclinical research for AKI drug development. PMID:26538634

  18. D0 Silicon Upgrade: End Calorimeter Transfer Bridge Design and Installation Procedures

    SciTech Connect

    Stredde, H.J.; /Fermilab

    1991-02-25

    elevated to the level of the transfer bridge. The elevation process is the same as that used for the CC installation. When the correct elevation is attained the transporter extensions are positioned and fastened to the transporter on the south side. Static column supports will be added underneath the transporter to minimize deflections as the NEC is rolled off. The carriage extensions are now put in place and the Hilman rollers transferred into position under the extensions. The NEC is now ready to be pulled off of the transporter and onto the transfer bridge. Again using the Cyl. and chain mechanism, with the anchor point attached to the transporter extension on the north sidewalk, pull the NEC completely off of the transporter and onto the transfer bridge. Once the NEC is on the transfer bridge a rearrangement of equipment must be done. The transporter extension on the north sidewalk is decoupled from the transfer bridge and moved against the wall of the fixed counting area. The transporter extension at the south end of the transporter is removed, the transporter is decoupled from and moved to the north side of the transfer bridge. The transporter is supported from the floor at an elevation equal to the transfer bridge and coupled to it. The transporter extension is fastened to the north end of the transporter. The movement of the NEC now continues until it is back on the transporter. At this time the transfer bridge, concrete shield blocks and steel plates in the pit are removed. The detector is moved back to its normal parked position(cable bridge up). The NEC is lowered to the sidewalk (reverse of elevation procedure). Welding of the heads is then finished prior to final installation on the center beam. The final installation is identical to the CC installation, using all the same equipment. The finite element analysis of the transfer bridge design was done by Kay Weber of the Accelerator Mechanical Support Group.

  19. A designed buried salt bridge modulates heterodimerization of a membrane peptide.

    PubMed

    Shinde, Sandip; Binder, Jennifer K; Goyal, Bhupesh; Woodrum, B; De Munari, Sonia; Levitus, Marcia; Ghirlanda, Giovanna

    2014-11-01

    Specific helix-helix interactions underpin the correct assembly of multipass membrane proteins. Here, we show that a designed buried salt bridge mediates heterodimer formation of model transmembrane helical peptides in a pH-dependent manner. The model peptides bear side chains functionalized with either a carboxylic acid or a primary amine within a hydrophobic segment. The association behavior was monitored by Förster resonance energy transfer, revealing that heterodimer formation is maximized at a pH close to neutrality (pH 6.5), at which each peptide is found in a charged state. In contrast, heterodimerization is disfavored at low and high values of pH, because either the carboxylic acid or the primary amine is present in its neutral state, thus preventing the formation of a salt bridge. These findings provide a blueprint for the design and modulation of protein-protein interactions in membrane proteins.

  20. SS-Stabilizing Proteins Rationally: Intrinsic Disorder-Based Design of Stabilizing Disulphide Bridges in GFP.

    PubMed

    Melnik, Bogdan S; Povarnitsyna, Tatiana V; Glukhov, Anatoly S; Melnik, Tatyana N; Uversky, Vladimir N; Sarma, Ramaswamy H

    2012-01-01

    Abstract The most attractive and methodologically convenient way to enhance protein stability is via the introduction of disulphide bond(s). However, the effect of the artificially introduced SS-bond on protein stability is often quite unpredictable. This raises the question of how to choose the protein sites in an intelligent manner, so that the 'fastening' of these sites by the SS-bond(s) would provide maximal protein stability. We hypothesize that the successful design of a stabilizing SS-bond requires finding highly mobile protein regions. Using GFP as an illustrative example, we demonstrate that the knowledge of the peculiarities of the intramolecular hydrophobic interactions, combined with the understanding of the local intrinsic disorder propensities (that can be evaluated by various disorder predictors, e.g., PONDRFIT), is sufficient to find the candidate sites for the introduction of stabilizing SS-bridge(s). In fact, our analysis revealed that the insertion of the engineered SS-bridge between two highly flexible regions of GFP noticeably increased the conformational stability of this protein toward the thermal and chemical unfolding. Therefore, our study represents a novel approach for the rational design of stabilizing disulphide bridges in proteins.

  1. Salt bridges destabilize a leucine zipper designed for maximized ion pairing between helices.

    PubMed

    Phelan, Paul; Gorfe, Alemayehu A; Jelesarov, Ilian; Marti, Daniel N; Warwicker, James; Bosshard, Hans Rudolf

    2002-03-05

    Interhelical salt bridges are common in leucine zippers and are thought to stabilize the coiled coil conformation. Here we present a detailed thermodynamic investigation of the designed, disulfide-linked leucine zipper AB(SS) whose high-resolution NMR structure shows six interhelical ion pairs between heptad positions g of one helix and e' of the other helix but no ion pairing within single helices. The average pK(a) value of the Glu side chain carboxyl groups of AB(SS) is slightly higher than the pK(a) of a freely accessible Glu in an unfolded peptide [Marti, D. N., Jelesarov, I., and Bosshard, H. R. (2000) Biochemistry 39, 12804-12818]. This indicates that the salt bridges are destabilizing, a prediction we now have confirmed by determining the pH +/- stability profile of AB(SS). Circular dichroism-monitored unfolding by urea and by heating and differential scanning calorimetry show that the coiled coil conformation is approximately 5 kJ/mol more stable when salt bridges are broken by protonation of the carboxyl side chains. Using guanidinium chloride as the denaturant, the increase in the free energy of unfolding on protonation of the carboxyl side chains is larger, approximately 17 kJ/mol. The discrepancy between urea and guanidinium chloride unfolding can be ascribed to the ionic nature of guanidinium chloride, which screens charge-charge interactions. This work demonstrates the difficulty of predicting the energetic contribution of salt bridges from structural data alone even in a case where the ion pairs are seen in high-resolution NMR structures. The reason is that the contribution to stability results from a fine balance between energetically favorable Coulombic attractions and unfavorable desolvation of charges and conformational constraints of the residues involved in ion pairing. The apparent discrepancy between the results presented here and mutational studies indicating stabilization by salt bridges is discussed and resolved. An explanation is

  2. Design and characterization of a peptide mimotope of the HIV-1 gp120 bridging sheet.

    PubMed

    Schiavone, Marco; Fiume, Giuseppe; Caivano, Antonella; de Laurentiis, Annamaria; Falcone, Cristina; Masci, Francesca Fasanella; Iaccino, Enrico; Mimmi, Selena; Palmieri, Camillo; Pisano, Antonio; Pontoriero, Marilena; Rossi, Annalisa; Scialdone, Annarita; Vecchio, Eleonora; Andreozzi, Concetta; Trovato, Maria; Rafay, Jan; Ferko, Boris; Montefiori, David; Lombardi, Angela; Morsica, Giulia; Poli, Guido; Quinto, Ileana; Pavone, Vincenzo; de Berardinis, Piergiuseppe; Scala, Giuseppe

    2012-01-01

    The Bridging Sheet domain of HIV-1 gp120 is highly conserved among the HIV-1 strains and allows HIV-1 binding to host cells via the HIV-1 coreceptors. Further, the bridging sheet domain is a major target to neutralize HIV-1 infection. We rationally designed four linear peptide epitopes that mimic the three-dimensional structure of bridging sheet by using molecular modeling. Chemically synthesized peptides BS3 and BS4 showed a fair degree of antigenicity when tested in ELISA with IgG purified from HIV(+) broadly neutralizing sera while the production of synthetic peptides BS1 and BS2 failed due to their high degree of hydrophobicity. To overcome this limitation, we linked all four BS peptides to the COOH-terminus of GST protein to test both their antigenicity and immunogenicity. Only the BS1 peptide showed good antigenicity; however, no envelope specific antibodies were elicited upon mice immunization. Therefore we performed further analyses by linking BS1 peptide to the NH2-terminus of the E2 scaffold from the Geobacillus Stearothermophylus PDH complex. The E2-BS1 fusion peptide showed good antigenic results, however only one immunized rabbit elicited good antibody titers towards both the monomeric and oligomeric viral envelope glycoprotein (Env). In addition, moderate neutralizing antibodies response was elicited against two HIV-1 clade B and one clade C primary isolates. These preliminary data validate the peptide mimotope approach as a promising tool to obtain an effective HIV-1 vaccine.

  3. The effect of sprue design and alloy type on the fit of three-unit metal/ceramic bridges.

    PubMed

    Johnson, A

    1995-12-01

    This study was designed to compare the effect of three sprue designs and three types of metal alloy/ceramic on the accuracy of fit of three unit bridges. A sprue design which has straight sprues attached directly to the pattern but does not have a button of excess metal connecting the sprues together after casting, produced the best marginal accuracy, irrespective of the alloy type used. Of the three alloys used (gold, palladium and nickel/chromium based alloys) the gold alloy produced better fitting bridges with each sprue design used.

  4. Biaxial Behavior of Ultra-High Performance Concrete and Untreated UHPC Waffle Slab Bridge Deck Design and Testing

    NASA Astrophysics Data System (ADS)

    D'Alessandro, Kacie Caple

    Ultra-high performance concrete (UHPC) was evaluated as a potential material for future bridge deck designs. Material characterization tests took place to identify potential challenges in mixing, placing, and curing UHPC. Biaxial testing was performed to evaluate behavior of UHPC in combined tension and compression stress states. A UHPC bridge deck was designed to perform similarly to a conventional concrete bridge deck, and a single unit bridge deck section was tested to evaluate the design methods used for untreated UHPC. Material tests identified challenges with placing UHPC. A specified compressive strength was determined for structural design using untreated UHPC, which was identified as a cost-effective alternative to steam treated UHPC. UHPC was tested in biaxial tension-compression stress states. A biaxial test method was developed for UHPC to directly apply tension and compression. The influence of both curing method and fiber orientation were evaluated. The failure envelope developed for untreated UHPC with random fiber orientation was suggested as a conservative estimate for future analysis of UHPC. Digital image correlation was also evaluated as a means to estimate surface strains of UHPC, and recommendations are provided to improve consistency in future tests using DIC methods. A preliminary bridge deck design was completed for untreated UHPC and using established material models. Prestressing steel was used as primary reinforcement in the transverse direction. Preliminary testing was used to evaluate three different placement scenarios, and results showed that fiber settling was a potential placement problem resulting in reduced tensile strength. The UHPC bridge deck was redesigned to incorporate preliminary test results, and two single unit bridge deck sections were tested to evaluate the incorporated design methods for both upside down and right-side up placement techniques. Test results showed that the applied design methods would be conservative

  5. Myocutaneous flap (V-Y design) from the nasal bridge for medial canthal reconstruction.

    PubMed

    Moretti, E A; Gomez Garcia, F

    1998-07-01

    Repair of soft tissue loss of the medial canthal area is usually accomplished by using skin grafts or frontal flaps based on the glabellar vessels. However, skin grafts can provoke scar tissue contracture, or skin color chromatic changes (hypopigmentation or hyperpigmentation). On the other hand, frontal flaps are sometimes thicker than normal skin and lead to unsatisfactory aesthetic results. To avoid these disadvantages, the authors designed an alternative method for reconstruction of defects of the medical canthal area. The authors suggest using a myocutaneous flap (V-Y design) from the nasal bridge to repair soft tissue defects no larger than 2 cm in diameter (surface < 4 cm2) in the medial canthal area. The pedicle of this flap is based on supratrochlear and dorsal nasal vessels. This technique has proved safe and reliable and has led to good functional and cosmetic results.

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

    PubMed Central

    Barrozo, Alexandre; Borstnar, Rok; Marloie, Gaël; Kamerlin, Shina Caroline Lynn

    2012-01-01

    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. PMID:23202907

  7. A miniature MRE isolator for lateral vibration suppression of bridge monitoring equipment: design and verification

    NASA Astrophysics Data System (ADS)

    Zhao, Lujie; Yu, Miao; Fu, Jie; Zhu, Mi; Li, Binshang

    2017-04-01

    The testing accuracy and service life of long-span bridge monitoring equipment declines over time due to the adverse effects of environmental vibration during its operation. Therefore, it is essential to use effective methods to reduce the vibration of these devices. In this paper, inspired by the controllable and field-dependent properties of magnetorheological elastomer (MRE), a miniature laminated MRE isolator is designed and manufactured to provide a relatively stable working environment for the monitoring equipment. The method and process of its specific design are elaborated in detail based on the shape factor, allowable seismic displacement, lateral stiffness, allowable vertical load and analysis of magnetic circuit. Besides, a series of dynamic tests are conducted to obtain the characteristics of the MRE isolator under various loading conditions. The experimental results show that the maximum increase of the effective stiffness is 114.12% with the current increasing from 0 A to 3 A. Consequently, the validity of its design is confirmed by a fuzzy control experiment.

  8. Topological design of all-ceramic dental bridges for enhancing fracture resistance.

    PubMed

    Zhang, Zhongpu; Chen, Junning; Li, Eric; Li, Wei; Swain, Michael; Li, Qing

    2016-06-01

    Layered all-ceramic systems have been increasingly adopted in major dental prostheses. However, ceramics are inherently brittle, and they often subject to premature failure under high occlusion forces especially in the posterior region. This study aimed to develop mechanically sound novel topological designs for all-ceramic dental bridges by minimizing the fracture incidence under given loading conditions. A bi-directional evolutionary structural optimization (BESO) technique is implemented within the extended finite element method (XFEM) framework. Extended finite element method allows modeling crack initiation and propagation inside all-ceramic restoration systems. Following this, BESO searches the optimum distribution of two different ceramic materials, namely porcelain and zirconia, for minimizing fracture incidence. A performance index, as per a ratio of peak tensile stress to material strength, is used as a design objective. In this study, the novel XFEM based BESO topology optimization significantly improved structural strength by minimizing performance index for suppressing fracture incidence in the structures. As expected, the fracture resistance and factor of safety of fixed partial dentures structure increased upon redistributing zirconia and porcelain in the optimal topological configuration. Dental CAD/CAM systems and the emerging 3D printing technology were commercially available to facilitate implementation of such a computational design, exhibiting considerable potential for clinical application in the future. Copyright © 2015 John Wiley & Sons, Ltd.

  9. A BASIC STUDY OF EVALUATION STRUCTURE TO VISUAL DESIGN OF NEO-FUNCTIONALISM BRIDGES

    NASA Astrophysics Data System (ADS)

    Matsui, Teppei; Sasaki, Yoh

    This research's final goal is to clarify how people focus on the external appearance of neo-functionalism bridges which are characterized by their distinguishing morphological features, and also determine whether people evaluate these bridges and how they do it. As a first step, the research focuses on the Through-type Arch Bridge and attempts to make clear the evaluation structure by means of an experimental psychology approach. Upon this, the dynamic image will be defined by the vitality flow and motion impression that characterize this kind of bridge. The sensibility evaluation experiment is carried out by using CG that reflects the changes of related feature shapes. Thus, the relationship between the assortments of the bridge's morphological characteristic and its impression are analyzed by using Rough Set Theory. As a result, it was possible to find out a variety of evaluation trends related to the intellectual background of the bridge observer and also establish the distinct characteristics of various evaluation trends.

  10. LOOKING WNW, CHEVROLET AVENUE BRIDGE CROSSING FLINT RIVER. BRIDGE CONNECTED ...

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

    LOOKING WNW, CHEVROLET AVENUE BRIDGE CROSSING FLINT RIVER. BRIDGE CONNECTED NORTH AND SOUTH PORTIONS OF FACTORY COMPLEX. DANIEL LUTEN DESIGNED THE BRIDGE, AND ILLINOIS BRIDGE COMPANY BUILT IT IN 1918. THE BRIDGE WAS THE SITE OF THE BATTLE OF RUNNING BULLS IN THE 1936-1937 GM SIT DOWN STRIKE. - Delphi Flint West, 300 Chevrolet Avenue, Flint, Genesee County, MI

  11. Design of disulfide bridge as an alternative mechanism for color shift in firefly luciferase and development of secreted luciferase.

    PubMed

    Nazari, Mahboobeh; Hosseinkhani, Saman

    2011-07-01

    The bioluminescence reaction, which uses luciferin, Mg(2+)-ATP and molecular oxygen to yield an electronically excited oxyluciferin, is carried out by luciferase and emits visible light. The bioluminescence color of firefly luciferases is determined by the luciferase structure and assay conditions. It is proposed that the stability of a protein can be increased by introduction of disulfide bridge that decreases the configurational entropy of unfolding. A disulfide bridge is introduced into Photinus pyralis firefly luciferase to make three separate mutant enzymes with a single bridge. Moreover, C(81)-A(105)C mutant luciferase was modified and successfully secreted to the extracellular medium. By introduction of disulfide bridges using site-directed mutagenesis in Photinus pyralis luciferase the color of emitted light was changed to red and the optimum temperature of activity was also increased (up to 10 °C more than wild type). Amongst mutants with a disulfide bridge, P(451)C-V(469)C and L(306)C-L(309)C mutants exhibit a single peak in the red region of the spectrum at pH 7.8. It is worthwhile to note that with the design of a secreted luciferase, the increased optimum temperature, thermostability and emission of red light might make mutant luciferase suitable reporters for the study of gene expression in high through-put screening.

  12. Phospholipid-based nonlamellar mesophases for delivery systems: bridging the gap between empirical and rational design.

    PubMed

    Martiel, Isabelle; Sagalowicz, Laurent; Mezzenga, Raffaele

    2014-07-01

    Phospholipids are ubiquitous cell membrane components and relatively well-accepted ingredients due to their natural origin. Phosphatidylcholine (PC) in particular offers a promising alternative to monoglycerides for lyotropic liquid crystalline (LLC) delivery system applications in the food, cosmetics and pharmaceutical industries, provided its strong tendency to form zero-mean curvature lamellar mesophases in water can be overcome. Higher negative curvatures are usually reached through the addition of a third lipid component, forming a ternary diagram phospholipid/water/oil. The initial part of this work summarizes the potential advantages and the challenges of phospholipid-based delivery system applications. In the next part, various ternary PC/water/oil systems are discussed, with a special emphasis on the PC/water/cyclohexane and PC/water/α-tocopherol systems. We report that R-(+)-limonene has a quantitatively similar effect as cyclohexane. The last part is devoted to the theoretical interpretation of the observed phase behaviors. A fruitful parallel is drawn with PC polymer-like reverse micelles, leading to a thermodynamic description in terms of interfacial bending energy. Investigations at the molecular level are reviewed to help in bridging the empirical and theoretical approaches. Predictive rules are finally derived from this wide-ranging overview, thereby opening the way to a future rational design of PC-based LLC delivery systems.

  13. Design and construction of the lawnmower, an artificial burnt-bridges motor.

    PubMed

    Kovacic, Suzana; Samii, Laleh; Curmi, Paul M G; Linke, Heiner; Zuckermann, Martin J; Forde, Nancy R

    2015-04-01

    Molecular motors of the cell are protein-based, nanoscale machines, which use a variety of strategies to transduce chemical energy into mechanical work in the presence of a large thermal background. The design and construction of artificial molecular motors is one approach to better understand their basic physical principles. Here, we propose the concept of a protein-based, burnt-bridges ratchet, inspired by biological examples. Our concept, the lawnmower, utilizes protease blades to cleave peptide substrates, and uses the asymmetric substrate-product interface arising from productive cleavage to bias subsequent diffusion on the track (lawn). Following experimental screening to select a protease to act as the motor's blades, we chemically couple trypsin to quantum dots and demonstrate activity of the resulting lawnmower construct in solution. Accompanying Brownian dynamics simulations illustrate the importance for processivity of correct protease density on the quantum dot and spacing of substrates on the track. These results lay the groundwork for future tests of the protein-based lawnmower's motor performance characteristics.

  14. Design and parametric study on energy harvesting from bridge vibration using tuned dual-mass damper systems

    NASA Astrophysics Data System (ADS)

    Takeya, Kouichi; Sasaki, Eiichi; Kobayashi, Yusuke

    2016-01-01

    A bridge vibration energy harvester has been proposed in this paper using a tuned dual-mass damper system, named hereafter Tuned Mass Generator (TMG). A linear electromagnetic transducer has been applied to harvest and make use of the unused reserve of energy the aforementioned damper system absorbs. The benefits of using dual-mass systems over single-mass systems for power generation have been clarified according to the theory of vibrations. TMG parameters have been determined considering multi-domain parameters, and TMG has been tuned using a newly proposed parameter design method. Theoretical analysis results have shown that for effective energy harvesting, it is essential that TMG has robustness against uncertainties in bridge vibrations and tuning errors, and the proposed parameter design method for TMG has demonstrated this feature.

  15. [Design and manufacture of mechanic modeling of fluid dynamics related to the myocardial bridging and mural coronary artery].

    PubMed

    Zhang, Guohui; Ge, Junbo; Shen, Lixing; Wang, Keqiang; Qian, Juying; Fan, Bing; Xu, Genlin; Ding, Hao; Zhang, Feng

    2005-06-01

    A model of fluid dynamics related to the myocardial bridginged and mural coronary artery was designed and manufactured according to the physical principle and characteristic of the mural coronary artery. The model can imitate systematically well the effect of myocardial bridging on hemodynamic change of the mural coronary artery under different controlled experimental parameter. The methodology is proved to be feasible and has good prosperity of experimental study.

  16. Experimental design for the evaluation of high-T(sub c) superconductive thermal bridges in a sensor satellite

    NASA Astrophysics Data System (ADS)

    Scott, Elaine P.; Lee, Kasey M.

    1994-10-01

    Infrared sensor satellites, which consist of cryogenic infrared sensor detectors, electrical instrumentation, and data acquisition systems, are used to monitor the conditions of the earth's upper atmosphere in order to evaluate its present and future changes. Currently, the electrical connections (instrumentation), which act as thermal bridges between the cryogenic infrared sensor and the significantly warmer data acquisition unit of the sensor satellite system, constitute a significant portion of the heat load on the cryogen. As a part of extending the mission life of the sensor satellite system, the researchers at the National Aeronautics and Space Administration's Langley Research Center (NASA-LaRC) are evaluating the effectiveness of replacing the currently used manganin wires with high-temperature superconductive (HTS) materials as the electrical connections (thermal bridges). In conjunction with the study being conducted at NASA-LaRC, the proposed research is to design a space experiment to determine the thermal savings on a cryogenic subsystem when manganin leads are replaced by HTS leads printed onto a substrate with a low thermal conductivity, and to determine the thermal conductivities of HTS materials. The experiment is designed to compare manganin wires with two different types of superconductors on substrates by determining the heat loss by the thermal bridges and providing temperature measurements for the estimation of thermal conductivity. A conductive mathematical model has been developed and used as a key tool in the design process and subsequent analysis.

  17. Experimental design for the evaluation of high-T(sub c) superconductive thermal bridges in a sensor satellite

    NASA Technical Reports Server (NTRS)

    Scott, Elaine P.; Lee, Kasey M.

    1994-01-01

    Infrared sensor satellites, which consist of cryogenic infrared sensor detectors, electrical instrumentation, and data acquisition systems, are used to monitor the conditions of the earth's upper atmosphere in order to evaluate its present and future changes. Currently, the electrical connections (instrumentation), which act as thermal bridges between the cryogenic infrared sensor and the significantly warmer data acquisition unit of the sensor satellite system, constitute a significant portion of the heat load on the cryogen. As a part of extending the mission life of the sensor satellite system, the researchers at the National Aeronautics and Space Administration's Langley Research Center (NASA-LaRC) are evaluating the effectiveness of replacing the currently used manganin wires with high-temperature superconductive (HTS) materials as the electrical connections (thermal bridges). In conjunction with the study being conducted at NASA-LaRC, the proposed research is to design a space experiment to determine the thermal savings on a cryogenic subsystem when manganin leads are replaced by HTS leads printed onto a substrate with a low thermal conductivity, and to determine the thermal conductivities of HTS materials. The experiment is designed to compare manganin wires with two different types of superconductors on substrates by determining the heat loss by the thermal bridges and providing temperature measurements for the estimation of thermal conductivity. A conductive mathematical model has been developed and used as a key tool in the design process and subsequent analysis.

  18. Analytical model and design of spoke-type permanent-magnet machines accounting for saturation and nonlinearity of magnetic bridges

    NASA Astrophysics Data System (ADS)

    Liang, Peixin; Chai, Feng; Bi, Yunlong; Pei, Yulong; Cheng, Shukang

    2016-11-01

    Based on subdomain model, this paper presents an analytical method for predicting the no-load magnetic field distribution, back-EMF and torque in general spoke-type motors with magnetic bridges. Taking into account the saturation and nonlinearity of magnetic material, the magnetic bridges are equivalent to fan-shaped saturation regions. For getting standard boundary conditions, a lumped parameter magnetic circuit model and iterative method are employed to calculate the permeability. The final field domain is divided into five types of simple subdomains. Based on the method of separation of variables, the analytical expression of each subdomain is derived. The analytical results of the magnetic field distribution, Back-EMF and torque are verified by finite element method, which confirms the validity of the proposed model for facilitating the motor design and optimization.

  19. Theoretical design and screening of alkyne bridged triphenyl zinc porphyrins as sensitizer candidates for dye-sensitized solar cells.

    PubMed

    Zhang, Xianxi; Chen, Qianqian; Sun, Huafei; Pan, Tingting; Hu, Guiqi; Ma, Ruimin; Dou, Jianmin; Li, Dacheng; Pan, Xu

    2014-01-24

    Alkyne bridged porphyrins have been proved very promising sensitizers for dye-sensitized solar cells (DSSCs) with the highest photo-to-electric conversion efficiencies of 11.9% solely and 12.3% co-sensitized with other sensitizers achieved. Developing better porphyrin sensitizers with wider electronic absorption spectra to further improve the efficiencies of corresponding solar cells is still of great significance for the application of DSSCs. A series of triphenyl zinc porphyrins (ZnTriPP) differing in the nature of a pendant acceptor group and the conjugated bridge between the porphyrin nucleus and the acceptor unit were modeled and their electronic and spectral properties calculated using density functional theory. As compared with each other and the experimental results of the compounds used in DSSCs previously, the molecules with a relatively longer conjugative linker and a strong electron-withdrawing group such as cyanide adjacent to the carboxyl acid group seem to provide wider electronic absorption spectra and higher photo-to-electric conversion efficiencies. The dye candidates ZnTriPPE, ZnTriPPM, ZnTriPPQ, ZnTriPPR and ZnTriPPS designed in the current work were found promising to provide comparable photo-to-electric conversion efficiencies to the record 11.9% of the alkyne bridged porphyrin sensitizer YD2-o-C8 reported previously.

  20. Theoretical design and screening of alkyne bridged triphenyl zinc porphyrins as sensitizer candidates for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Zhang, Xianxi; Chen, Qianqian; Sun, Huafei; Pan, Tingting; Hu, Guiqi; Ma, Ruimin; Dou, Jianmin; Li, Dacheng; Pan, Xu

    2014-01-01

    Alkyne bridged porphyrins have been proved very promising sensitizers for dye-sensitized solar cells (DSSCs) with the highest photo-to-electric conversion efficiencies of 11.9% solely and 12.3% co-sensitized with other sensitizers achieved. Developing better porphyrin sensitizers with wider electronic absorption spectra to further improve the efficiencies of corresponding solar cells is still of great significance for the application of DSSCs. A series of triphenyl zinc porphyrins (ZnTriPP) differing in the nature of a pendant acceptor group and the conjugated bridge between the porphyrin nucleus and the acceptor unit were modeled and their electronic and spectral properties calculated using density functional theory. As compared with each other and the experimental results of the compounds used in DSSCs previously, the molecules with a relatively longer conjugative linker and a strong electron-withdrawing group such as cyanide adjacent to the carboxyl acid group seem to provide wider electronic absorption spectra and higher photo-to-electric conversion efficiencies. The dye candidates ZnTriPPE, ZnTriPPM, ZnTriPPQ, ZnTriPPR and ZnTriPPS designed in the current work were found promising to provide comparable photo-to-electric conversion efficiencies to the record 11.9% of the alkyne bridged porphyrin sensitizer YD2-o-C8 reported previously.

  1. Environmentally Friendly Solution to Ground Hazards in Design of Bridges in Earthquake Prone Areas Using Timber Piles

    NASA Astrophysics Data System (ADS)

    Sadeghi, H.

    2015-12-01

    Bridges are major elements of infrastructure in all societies. Their safety and continued serviceability guaranties the transportation and emergency access in urban and rural areas. However, these important structures are subject to earthquake induced damages in structure and foundations. The basic approach to the proper support of foundations are a) distribution of imposed loads to foundation in a way they can resist those loads without excessive settlement and failure; b) modification of foundation ground with various available methods; and c) combination of "a" and "b". The engineers has to face the task of designing the foundations meeting all safely and serviceability criteria but sometimes when there are numerous environmental and financial constrains, the use of some traditional methods become inevitable. This paper explains the application of timber piles to improve ground resistance to liquefaction and to secure the abutments of short to medium length bridges in an earthquake/liquefaction prone area in Bohol Island, Philippines. The limitations of using the common ground improvement methods (i.e., injection, dynamic compaction) because of either environmental or financial concerns along with the abundance of timber in the area made the engineers to use a network of timber piles behind the backwalls of the bridge abutments. The suggested timber pile network is simulated by numerical methods and its safety is examined. The results show that the compaction caused by driving of the piles and bearing capacity provided by timbers reduce the settlement and lateral movements due to service and earthquake induced loads.

  2. Design and optimization of micro-semiconductor bridge used for solid propellant microthrusters array

    NASA Astrophysics Data System (ADS)

    Ru, Chengbo; Dai, Ji; Xu, Jianbing; Ye, Yinghua; Zhu, Peng; Shen, Ruiqi

    2016-06-01

    Igniter is the basic component of MEMS-based solid propellant microthrusters (SPM) array, which should response fast with low dissipated energy. To satisfy the requirements, micro-semiconductor bridge (MSCB) with dual V-angles contributing to the reduction of dissipated energy is introduced into the array. The electrical explosion characteristics of MSCB investigated under constant voltage, in the considerations of the limit of power supply in the micro/nanosatellite, are similar to those under capacitive discharge. The bridge was completely vaporized and burst into the hot plasma under high-level voltage. While under low-level voltage, the bridge was partly vaporized without detected plasma. The 3#SCB (90° V-angle) with the smallest power density resulting in the lowest applied voltage (12.0 V) and the 2#SCB with the smallest narrow width (Wmin) leading to the lowest average power (11.3 W) were chosen to the further optimization. The ignition tests were implemented to examine the ignition reliability of the contractible igniters, which were optimized to satisfy the voltage limitation with sufficient ignition capacity. The results show that the effective SCB with lowest dissipated power is the 3#-3SCB, which function within 100 μ under 7.0 V, and the average power below 5.0 W.

  3. Bridge permeameter

    DOEpatents

    Graf, Darin C.; Warpinski, Norman R.

    1996-01-01

    A system for single-phase, steady-state permeability measurements of porous rock utilizes a fluid bridge arrangement analogous to a Wheatstone bridge. The arms of the bridge contain the sample and calibrated flow resistors.

  4. APPLICATION OF STEEL PIPE PILE LOADING TESTS TO DESIGN VERIFICATION OF FOUNDATION OF THE TOKYO GATE BRIDGE

    NASA Astrophysics Data System (ADS)

    Saitou, Yutaka; Kikuchi, Yoshiaki; Kusakabe, Osamu; Kiyomiya, Osamu; Yoneyama, Haruo; Kawakami, Taiji

    Steel sheet pipe pile foundations with large diameter steel pipe sheet pile were used for the foundation of the main pier of the Tokyo Gateway bridge. However, as for the large diameter steel pipe pile, the bearing mechanism including a pile tip plugging effect is still unclear due to lack of the practical examinations even though loading tests are performed on Trans-Tokyo Bay Highway. In the light of the foregoing problems, static pile loading tests both vertical and horizontal directions, a dynamic loading test, and cone penetration tests we re conducted for determining proper design parameters of the ground for the foundations. Design parameters were determined rationally based on the tests results. Rational design verification was obtained from this research.

  5. Three Bridge Fryer's Ford Bridge, Nimrod Bridge, and Ward's ...

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

    Three Bridge - Fryer's Ford Bridge, Nimrod Bridge, and Ward's Crossing Bridge - Fryer's Ford Bridge, Spanning East Fork of Point Remove Creek at Fryer Bridge Road (CR 67), Solgohachia, Conway County, AR

  6. Bridging the Gap between Experts in Designing Multimedia-Based Instructional Media for Learning

    ERIC Educational Resources Information Center

    Razak, Rafiza Abdul

    2013-01-01

    The research identified and explored the cognitive knowledge among the instructional multimedia design and development experts comprising of multimedia designer, graphic designer, subject-matter expert and instructional designer. A critical need exists for a solid understanding of the factors that influence team decision making and performance in…

  7. Evaluation of Bridges Subjected to Military Loading and Dynamic Hydraulic Effects: Review of Design Regulations, Selection Criteria, and Inspection Procedures for Bridge Railing Systems

    DTIC Science & Technology

    2011-08-01

    Standard Plans Plan Title Precast Concrete F-Shape Barrier Std Drawing for Two Tube Rail was not available. Plan No. G-46.10 End Treatments Plan...Anchorage Type 1 Guardrail Anchorage Type 5 and 6 - Guardrail Attachment to Columns, Piers, Walls Guardrail Anchorage Type 12 Concrete Barrier...inspection of the bridge railings. Railings Concrete Railings Vertical Concrete Parapet New Jersey Barrier Tall Wall F Shape Barrier

  8. Bridging the Gap between Designers and Consumers: The Role of Effective and Accurate Personas

    ERIC Educational Resources Information Center

    Miaskiewicz, Tomasz

    2010-01-01

    Firms now routinely collect information about the needs of their customers, but this information is not sufficiently considered during product design decisions. This research examines the relationship between designers and consumers to build an understanding of how the consumer should be represented to increase the consumer focus during the…

  9. Design, Synthesis and Evaluation of Organic Non-linear Optical Chromophores with Configurationally and Conformationally Locked Polyene Bridges

    DTIC Science & Technology

    2007-11-02

    A modular, synthetic scheme was developed for versatile variation of donors, acceptors and polyene bridge length of NLO-chromophores. Configurational...and conformational rigidity of the polyene bridges were realized by making each set of adjacent double and single bond pair part of a fused...cylohexene ring. Substituent effects on the reactions leading to the establishment of the donor, elongation of the fused polyene bridge and the final

  10. Bridge permeameter

    DOEpatents

    Graf, D.C.; Warpinski, N.R.

    1996-08-13

    A system is described for single-phase, steady-state permeability measurements of porous rock which utilizes a fluid bridge arrangement analogous to a Wheatstone bridge. The arms of the bridge contain the sample and calibrated flow resistors. 8 figs.

  11. Technology Transfer--Bridging Space and Society. The Students of the Technology Transfer Design Project Team (ISU Summer Session 1997).

    PubMed

    1997-01-01

    Strategies, policies and methods by which technologies can he cross-fertilized between the space and non-space sectors were examined by students of the design project "Technology Transfer--Bridging Space and Society". This project was undertaken by students attending the 1997 10th Anniversary Summer Session Program of the International Space University. General issues relating to transfer of technology were discussed including definitions and mechanisms (push, pull, interactive and pro-active). As well as looking at case studies and the impact of national policies on space agencies, the design project also sought to look at technology transfer on a country-by-country basis, selecting various countries for scrutiny and reporting on their technology transfer status. The project report shows how transfer of technology varies between nations and when analyzed with the case studies identifies the general strategies, policies and methods in use and how they can he improved. Finally, the report seeks to recommend certain issues to governments, space agencies and industrial organizations to facilitate the transfer of technology. These include the development of a generic metrics system and the implementation of better appropriate procedures and mechanisms for a positive diffusion process between space and non-space sectors.

  12. Structure-Based Design of a Novel SMYD3 Inhibitor that Bridges the SAM-and MEKK2-Binding Pockets.

    PubMed

    Van Aller, Glenn S; Graves, Alan P; Elkins, Patricia A; Bonnette, William G; McDevitt, Patrick J; Zappacosta, Francesca; Annan, Roland S; Dean, Tony W; Su, Dai-Shi; Carpenter, Christopher L; Mohammad, Helai P; Kruger, Ryan G

    2016-05-03

    SMYD3 is a lysine methyltransferase overexpressed in colorectal, breast, prostate, and hepatocellular tumors, and has been implicated as an oncogene in human malignancies. Methylation of MEKK2 by SMYD3 is important for regulation of the MEK/ERK pathway, suggesting the possibility of selectively targeting SMYD3 in RAS-driven cancers. Structural and kinetic characterization of SMYD3 was undertaken leading to a co-crystal structure of SMYD3 with a MEKK2-peptide substrate bound, and the observation that SMYD3 follows a partially processive mechanism. These insights allowed for the design of GSK2807, a potent and selective, SAM-competitive inhibitor of SMYD3 (Ki = 14 nM). A high-resolution crystal structure reveals that GSK2807 bridges the gap between the SAM-binding pocket and the substrate lysine tunnel of SMYD3. Taken together, our data demonstrate that small-molecule inhibitors of SMYD3 can be designed to prevent methylation of MEKK2 and these could have potential use as anticancer therapeutics.

  13. Building Bridges to Connect the Disconnects: An Analysis of Business Program Design Processes

    ERIC Educational Resources Information Center

    Fleming, Debra L.

    2008-01-01

    The purpose of this study is to analyze current trends of design processes and redesign efforts for business programs. A review of the literature suggests business schools are not preparing graduates of their programs with the necessary knowledge, skills and dispositions as deemed appropriate to succeed in the world of work. Some research studies…

  14. Cybersecurity Protection: Design Science Research toward an Intercloud Transparent Bridge Architecture (ICTOBRA)

    ERIC Educational Resources Information Center

    Wilson, Joe M.

    2013-01-01

    This dissertation uses design science research and engineering to develop a cloud-based simulator for modeling next-generation cybersecurity protection frameworks in the United States. The claim is made that an agile and neutral framework extending throughout the cyber-threat plane is needed for critical infrastructure protection (CIP). This…

  15. Universal Design for Learning as a Bridge to Inclusion: A Qualitative Report of Student Voices

    ERIC Educational Resources Information Center

    Katz, Jennifer; Sokal, Laura

    2016-01-01

    Innovations in pedagogy are, at their core, aimed at improving the educational experiences and outcomes of learners. Being as many countries are embracing a philosophy of inclusive education, designers of educational reform must be mindful of the effects of any proposed innovations on the experiences and outcomes of a broad range of diverse…

  16. Effects of Thinking Style on Design Strategies: Using Bridge Construction Simulation Programs

    ERIC Educational Resources Information Center

    Sun, Chuen-Tsai; Wang, Dai-Yi; Chang, Yu-Yeh

    2013-01-01

    Computer simulation users can freely control operational factors and simulation results, repeat processes, make changes, and learn from simulation environment feedback. The focus of this paper is on simulation-based design tools and their effects on student learning processes in a group of 101 Taiwanese senior high school students. Participants…

  17. Bridging Theory and Practice: Developing Guidelines to Facilitate the Design of Computer-Based Learning Environments

    ERIC Educational Resources Information Center

    Young, Lisa D.

    2003-01-01

    The design of computer-­based learning environments has undergone a paradigm shift; moving students away from instruction that was considered to promote technical rationality grounded in objectivism, to the application of computers to create cognitive tools utilized in constructivist environments. The goal of the resulting computer-­based learning…

  18. Design, synthesis, insecticidal activity, and structure-activity relationship (SAR): studies of novel triazone derivatives containing a urea bridge group based on transient receptor potential (TRP) channels.

    PubMed

    Yang, Yan; Liu, Yuxiu; Song, Hongjian; Li, Yongqiang; Wang, Qingmin

    2016-11-01

    Numerous compounds containing urea bridge and biurea moieties are used in a variety of fields, especially as drugs and pesticides. To search for novel, environmentally benign and ecologically safe pesticides with unique modes of action, four series of novel triazone analogues containing urea, thiourea, biurea, and thiobiurea bridge, respectively, were designed and synthesized, according to various calcium ion channel inhibitors which act on transient receptor potential protein. Their structures were characterized by [Formula: see text] NMR, [Formula: see text] NMR, and HRMS. The insecticidal activities of the new compounds were obtained. The bioassay results indicated that compounds containing a thiourea bridge and a thiobiurea bridge exhibited excellent insecticidal activities against bean aphid. Specifically, compounds [Formula: see text], [Formula: see text], and [Formula: see text] exhibited 85, 90, and 95 % activities, respectively, at 10 mg/kg. Compounds [Formula: see text] (30 %), [Formula: see text] (35 %), [Formula: see text] (30 %), and [Formula: see text] (40 %) exhibited the approximate aphicidal activity of pymetrozine (30 %) at 5 mg/kg. In addition, some target compounds exhibited insecticidal activities against lepidopteran pests. From a molecular design standpoint, the information obtained in this study could help in the further design of new derivatives with improved insecticidal activities.

  19. Bridging Theory with Practice: An Exploratory Study of Visualization Use and Design for Climate Model Comparison

    SciTech Connect

    Dasgupta, Aritra; Poco, Jorge; Wei, Yaxing; Cook, Robert B.; Bertini, Enrico; Silva, Claudio

    2015-03-16

    Evaluation methodologies in visualization have mostly focused on how well the tools and techniques cater to the analytical needs of the user. While this is important in determining the effectiveness of the tools and advancing the state-of-the-art in visualization research, a key area that has mostly been overlooked is how well established visualization theories and principles are instantiated in practice. This is especially relevant when domain experts, and not visualization researchers, design visualizations for analysis of their data or for broader dissemination of scientific knowledge. There is very little research on exploring the synergistic capabilities of cross-domain collaboration between domain experts and visualization researchers. To fill this gap, in this paper we describe the results of an exploratory study of climate data visualizations conducted in tight collaboration with a pool of climate scientists. The study analyzes a large set of static climate data visualizations for identifying their shortcomings in terms of visualization design. The outcome of the study is a classification scheme that categorizes the design problems in the form of a descriptive taxonomy. The taxonomy is a first attempt for systematically categorizing the types, causes, and consequences of design problems in visualizations created by domain experts. We demonstrate the use of the taxonomy for a number of purposes, such as, improving the existing climate data visualizations, reflecting on the impact of the problems for enabling domain experts in designing better visualizations, and also learning about the gaps and opportunities for future visualization research. We demonstrate the applicability of our taxonomy through a number of examples and discuss the lessons learnt and implications of our findings.

  20. Bridging Theory with Practice: An Exploratory Study of Visualization Use and Design for Climate Model Comparison.

    PubMed

    Dasgupta, Aritra; Poco, Jorge; Wei, Yaxing; Cook, Robert; Bertini, Enrico; Silva, Cláudio T

    2015-09-01

    Evaluation methodologies in visualization have mostly focused on how well the tools and techniques cater to the analytical needs of the user. While this is important in determining the effectiveness of the tools and advancing the state-of-the-art in visualization research, a key area that has mostly been overlooked is how well established visualization theories and principles are instantiated in practice. This is especially relevant when domain experts, and not visualization researchers, design visualizations for analysis of their data or for broader dissemination of scientific knowledge. There is very little research on exploring the synergistic capabilities of cross-domain collaboration between domain experts and visualization researchers. To fill this gap, in this paper we describe the results of an exploratory study of climate data visualizations conducted in tight collaboration with a pool of climate scientists. The study analyzes a large set of static climate data visualizations for identifying their shortcomings in terms of visualization design. The outcome of the study is a classification scheme that categorizes the design problems in the form of a descriptive taxonomy. The taxonomy is a first attempt for systematically categorizing the types, causes, and consequences of design problems in visualizations created by domain experts. We demonstrate the use of the taxonomy for a number of purposes, such as, improving the existing climate data visualizations, reflecting on the impact of the problems for enabling domain experts in designing better visualizations, and also learning about the gaps and opportunities for future visualization research. We demonstrate the applicability of our taxonomy through a number of examples and discuss the lessons learnt and implications of our findings.

  1. Bridging Theory with Practice: An Exploratory Study of Visualization Use and Design for Climate Model Comparison

    DOE PAGES

    Dasgupta, Aritra; Poco, Jorge; Wei, Yaxing; ...

    2015-03-16

    Evaluation methodologies in visualization have mostly focused on how well the tools and techniques cater to the analytical needs of the user. While this is important in determining the effectiveness of the tools and advancing the state-of-the-art in visualization research, a key area that has mostly been overlooked is how well established visualization theories and principles are instantiated in practice. This is especially relevant when domain experts, and not visualization researchers, design visualizations for analysis of their data or for broader dissemination of scientific knowledge. There is very little research on exploring the synergistic capabilities of cross-domain collaboration between domainmore » experts and visualization researchers. To fill this gap, in this paper we describe the results of an exploratory study of climate data visualizations conducted in tight collaboration with a pool of climate scientists. The study analyzes a large set of static climate data visualizations for identifying their shortcomings in terms of visualization design. The outcome of the study is a classification scheme that categorizes the design problems in the form of a descriptive taxonomy. The taxonomy is a first attempt for systematically categorizing the types, causes, and consequences of design problems in visualizations created by domain experts. We demonstrate the use of the taxonomy for a number of purposes, such as, improving the existing climate data visualizations, reflecting on the impact of the problems for enabling domain experts in designing better visualizations, and also learning about the gaps and opportunities for future visualization research. We demonstrate the applicability of our taxonomy through a number of examples and discuss the lessons learnt and implications of our findings.« less

  2. Existing Steel Railway Bridges Evaluation

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

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

  3. Bridging the Planning Gap: Linking Conceptual Army Design to Military Decision-Making

    DTIC Science & Technology

    2011-05-19

    complex than ever before.10 Political and military scientists alike have attempted to address this complexity with models, theories , techniques, and...Shimon Naveh for the Israeli Defense Forces (IDF), shares some of the same fundamental theory as the current concept of Army design. In early 2006...Israeli Defense Forces rejected the use of SOD for EBOA and 38 Horst W.L Rittel and Melvin M.Webber, “Dilemmas in the General Theory of Planning

  4. Bridging the Gap: A Roadmap to Breaking the Biological Design Barrier

    PubMed Central

    Beal, Jacob

    2015-01-01

    This paper presents an analysis of an emerging bottleneck in organism engineering, and paths by which it may be overcome. Recent years have seen the development of a profusion of synthetic biology tools, largely falling into two categories: high-level “design” tools aimed at mapping from organism specifications to nucleic acid sequences implementing those specifications, and low-level “build and test” tools aimed at faster, cheaper, and more reliable fabrication of those sequences and assays of their behavior in engineered biological organisms. Between the two families, however, there is a major gap: we still largely lack the predictive models and component characterization data required to effectively determine which of the many possible candidate sequences considered in the design phase are the most likely to produce useful results when built and tested. As low-level tools continue to mature, the bottleneck in biological systems engineering is shifting to be dominated by design, making this gap a critical barrier to progress. Considering how to address this gap, we find that widespread adoption of readily available analytic and assay methods is likely to lead to rapid improvement in available predictive models and component characterization models, as evidenced by a number of recent results. Such an enabling development is, in turn, likely to allow high-level tools to break the design barrier and support rapid development of transformative biological applications. PMID:25654077

  5. Bridging the conservation design and delivery gap for wetland bird habitat maintenance and restoration in the Midwestern United States

    USGS Publications Warehouse

    Thogmartin, W.E.; Potter, B.; Soulliere, G.

    2011-01-01

    The U.S. Fish and Wildlife Service's adoption of Strategic Habitat Conservation is intended to increase the effectiveness and efficiency of conservation delivery by targeting effort in areas where biological benefits are greatest. Conservation funding has not often been allocated in accordance with explicit biological endpoints, and the gap between conservation design (the identification of conservation priority areas) and delivery needs to be bridged to better meet conservation goals for multiple species and landscapes. We introduce a regional prioritization scheme for North American Wetlands Conservation Act funding which explicitly addresses Midwest regional goals for wetland-dependent birds. We developed decision-support maps to guide conservation of breeding and non-breeding wetland bird habitat. This exercise suggested ~55% of the Midwest consists of potential wetland bird habitat, and areas suited for maintenance (protection) were distinguished from those most suited to restoration. Areas with greater maintenance focus were identified for central Minnesota, southeastern Wisconsin, the Upper Mississippi and Illinois rivers, and the shore of western Lake Erie and Saginaw Bay. The shores of Lakes Michigan and Superior accommodated fewer waterbird species overall, but were also important for wetland bird habitat maintenance. Abundant areas suited for wetland restoration occurred in agricultural regions of central Illinois, western Iowa, and northern Indiana and Ohio. Use of this prioritization scheme can increase effectiveness, efficiency, transparency, and credibility to land and water conservation efforts for wetland birds in the Midwestern United States.

  6. Design, Synthesis, and Biological Evaluation of Novel Pyridine-Bridged Analogues of Combretastatin-A4 as Anticancer Agents

    PubMed Central

    2015-01-01

    A series of novel pyridine-bridged analogues of combretastatin-A4 (CA-4) were designed and synthesized. As expected, the 4-atom linker configuration retained little cytotoxicities in the compounds 2e, 3e, 3g, and 4i. Activities of the analogues with 3-atom linker varied widely depending on the phenyl ring substitutions, and the 3-atom linker containing nitrogen represents the more favorable linker structure. Among them, three analogues (4h, 4s, and 4t) potently inhibited cell survival and growth, arrested cell cycle, and blocked angiogenesis and vasculature formation in vivo in ways comparable to CA-4. The superposition of 4h and 4s in the colchicine-binding pocket of tubulin shows the binding posture of CA-4, 4h, and 4s are similar, as confirmed by the competitive binding assay where the ability of the ligands to replace tubulin-bound colchicine was measured. The binding data are consistent with the observed biological activities in antiproliferation and suppression of angiogenesis but are not predictive of their antitubulin polymerization activities. PMID:24669888

  7. Evolutionary bridges to new protein folds: design of C-terminal Cro protein chameleon sequences.

    PubMed

    Anderson, William J; Van Dorn, Laura O; Ingram, Wendy M; Cordes, Matthew H J

    2011-09-01

    Regions of amino-acid sequence that are compatible with multiple folds may facilitate evolutionary transitions in protein structure. In a previous study, we described a heuristically designed chameleon sequence (SASF1, structurally ambivalent sequence fragment 1) that could adopt either of two naturally occurring conformations (α-helical or β-sheet) when incorporated as part of the C-terminal dimerization subdomain of two structurally divergent transcription factors, P22 Cro and λ Cro. Here we describe longer chameleon designs (SASF2 and SASF3) that in the case of SASF3 correspond to the full C-terminal half of the ordered region of a P22 Cro/λ Cro sequence alignment (residues 34-57). P22-SASF2 and λ(WDD)-SASF2 show moderate thermal stability in denaturation curves monitored by circular dichroism (T(m) values of 46 and 55°C, respectively), while P22-SASF3 and λ(WDD)-SASF3 have somewhat reduced stability (T(m) values of 33 and 49°C, respectively). (13)C and (1)H NMR secondary chemical shift analysis confirms two C-terminal α-helices for P22-SASF2 (residues 36-45 and 54-57) and two C-terminal β-strands for λ(WDD)-SASF2 (residues 40-45 and 50-52), corresponding to secondary structure locations in the two parent sequences. Backbone relaxation data show that both chameleon sequences have a relatively well-ordered structure. Comparisons of (15)N-(1)H correlation spectra for SASF2 and SASF3-containing proteins strongly suggest that SASF3 retains the chameleonism of SASF2. Both Cro C-terminal conformations can be encoded in a single sequence, showing the plausibility of linking different Cro folds by smooth evolutionary transitions. The N-terminal subdomain, though largely conserved in structure, also exerts an important contextual influence on the structure of the C-terminal region.

  8. Ontology Design Patterns: Bridging the Gap Between Local Semantic Use Cases and Large-Scale, Long-Term Data Integration

    NASA Astrophysics Data System (ADS)

    Shepherd, Adam; Arko, Robert; Krisnadhi, Adila; Hitzler, Pascal; Janowicz, Krzysztof; Chandler, Cyndy; Narock, Tom; Cheatham, Michelle; Schildhauer, Mark; Jones, Matt; Raymond, Lisa; Mickle, Audrey; Finin, Tim; Fils, Doug; Carbotte, Suzanne; Lehnert, Kerstin

    2015-04-01

    Integrating datasets for new use cases is one of the common drivers for adopting semantic web technologies. Even though linked data principles enables this type of activity over time, the task of reconciling new ontological commitments for newer use cases can be daunting. This situation was faced by the Biological and Chemical Oceanography Data Management Office (BCO-DMO) as it sought to integrate its existing linked data with other data repositories to address newer scientific use cases as a partner in the GeoLink Project. To achieve a successful integration with other GeoLink partners, BCO-DMO's metadata would need to be described using the new ontologies developed by the GeoLink partners - a situation that could impact semantic inferencing, pre-existing software and external users of BCO-DMO's linked data. This presentation describes the process of how GeoLink is bridging the gap between local, pre-existing ontologies to achieve scientific metadata integration for all its partners through the use of ontology design patterns. GeoLink, an NSF EarthCube Building Block, brings together experts from the geosciences, computer science, and library science in an effort to improve discovery and reuse of data and knowledge. Its participating repositories include content from field expeditions, laboratory analyses, journal publications, conference presentations, theses/reports, and funding awards that span scientific studies from marine geology to marine ecology and biogeochemistry to paleoclimatology. GeoLink's outcomes include a set of reusable ontology design patterns (ODPs) that describe core geoscience concepts, a network of Linked Data published by participating repositories using those ODPs, and tools to facilitate discovery of related content in multiple repositories.

  9. The Building Bridges Project: Involving Older Adults in the Design of a Communication Technology to Support Peer-to-Peer Social Engagement

    NASA Astrophysics Data System (ADS)

    Wherton, Joseph; Prendergast, David

    There are a variety of factors that can lead to social isolation and loneliness in old age, including decline in physical and mental health, as well as change to social environment. The Building Bridges project explores how communication technology can help older adults remain socially connected. This paper will first provide an overview of a prototype communication system designed to support peer-to-peer group interaction. A description of the user-centered design process will be provided to demonstrate the importance of involving older adults at the earliest stages. The implications for designing new technology for older adults are discussed.

  10. Development of Inspection Robots for Bridge Cables

    PubMed Central

    Kim, Se-Hoon; Lee, Jong-Jae

    2013-01-01

    This paper presents the bridge cable inspection robot developed in Korea. Two types of the cable inspection robots were developed for cable-suspension bridges and cable-stayed bridge. The design of the robot system and performance of the NDT techniques associated with the cable inspection robot are discussed. A review on recent advances in emerging robot-based inspection technologies for bridge cables and current bridge cable inspection methods is also presented. PMID:24459453

  11. Safer Bridges

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Safer bridges are among a number of spinoff benefits from NASA procedures for testing 'cfracture toughness" of a structural part, meaning its ability to -siscracktsh at might cause failure. The New River Bridge in West Virginia, shown under construction, is the world's largest single span bridge. U.S. Steel fracture toughness requirements for such bridges include NASA-developed test procedures. Bridge materials and other metal structures may develop flaws during their service lifetimes. Such flaws can affect the structural integrity of the part. Thus, it is important to know the "fracture toughness" of a structural part, or its ability to resist cracks. NASA has long experience in developing fracture toughness tests for aerospace hardware. Since 1960, NASA-Lewis has worked closely with the American Society for Testing & Materials. Lewis and NASA-funded industrial contractors have made many important contributions to test procedures, now recommended by ASTM, for measuring fracture toughness.

  12. Building a Straw Bridge

    ERIC Educational Resources Information Center

    Teaching Science, 2015

    2015-01-01

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

  13. An amateur's contribution to the design of Telford's Menai Suspension Bridge: a commentary on Gilbert (1826) ‘On the mathematical theory of suspension bridges’

    PubMed Central

    Calladine, C. R.

    2015-01-01

    Davies Gilbert's work on the catenary is notable on two counts. First, it influenced Thomas Telford in formulating his final design for the Menai Strait suspension bridge (1826); and second, it established for the first time the form of the ‘catenary of equal strength’. The classical catenary is a uniform flexible chain or cable hanging freely under gravity between supports. The ‘catenary of equal strength’ is the form of a cable whose cross-sectional area is made proportional to the tension at each point, so that the tensile stress is uniform throughout. In this paper I provide a sketch of the lives and achievements of Gilbert and Telford, and of their interaction over the Menai Bridge. There follows a commentary on Gilbert's 1826 paper, and on his two related publications; and a brief sketch of the earlier history of the catenary. I then describe the development of the suspension bridge up to the present time. Finally, I discuss relations between mathematical analysts and practical engineers. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society. PMID:25750153

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

    NASA Astrophysics Data System (ADS)

    Matsutani, Akihiro

    2004-05-01

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

  15. The Bridges Program.

    ERIC Educational Resources Information Center

    Bohnen, Elizabeth; Klie, Judy

    This report describes BRIDGES, an employment equity special measures training program developed by the City of Toronto (Ontario, Canada). It was designed to help women employees move from their traditional jobs into trades, technical or operation (TTO) jobs within their own organization. The program is a combination of classroom sessions, shop…

  16. Bridging the Gap?

    ERIC Educational Resources Information Center

    Salter, Colin

    2009-01-01

    The political context of the conversion of the Historic Tramway Bridge, adjacent to Sandon Point in Bulli (NSW, Australia), and how this was exploited to serve predetermined ends, illustrates that technologies can be designed to have particular social (and political) effects. Through reflection on this relatively small engineering project, this…

  17. Weigh-in-motion and smart bridges

    NASA Astrophysics Data System (ADS)

    Lai, Leon L.

    1997-05-01

    The bridge Weigh-In-Motion (WIM) system uses bridge structures as weigh scales to measure axle and gross vehicle weights and vehicle configurations without stopping or detouring the vehicles. Because the system is mobile and is almost invisible to the truck drivers, it can be used to collect unbiased traffic data for transportation and loadometer study. The WIM + RESPONSE system, which is an expansion of the original WIM system, was developed to collect additional bridge response data and perform bridge structural evaluation. These additional bridge response data provide bridge engineers with information necessary for improving bridge design and evaluation procedures. Bridge health monitoring and damage detection may also be conducted with long term installation of the WIM + RESPONSE system. This paper discusses what has been achieved by the WIM + RESPONSE system and how the system can be further improved to enhance its functions in a smart bridge.

  18. 49 CFR 236.713 - Bridge, movable.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Bridge, movable. 236.713 Section 236.713 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Bridge, movable. That section of a structure bridging a navigable waterway so designed that it may...

  19. 49 CFR 236.713 - Bridge, movable.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Bridge, movable. 236.713 Section 236.713 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Bridge, movable. That section of a structure bridging a navigable waterway so designed that it may...

  20. 49 CFR 236.713 - Bridge, movable.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Bridge, movable. That section of a structure bridging a navigable waterway so designed that it may be... 49 Transportation 4 2010-10-01 2010-10-01 false Bridge, movable. 236.713 Section 236.713 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  1. 49 CFR 236.713 - Bridge, movable.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Bridge, movable. That section of a structure bridging a navigable waterway so designed that it may be... 49 Transportation 4 2013-10-01 2013-10-01 false Bridge, movable. 236.713 Section 236.713 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  2. 49 CFR 236.713 - Bridge, movable.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Bridge, movable. That section of a structure bridging a navigable waterway so designed that it may be... 49 Transportation 4 2014-10-01 2014-10-01 false Bridge, movable. 236.713 Section 236.713 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  3. Bridges, 2002.

    ERIC Educational Resources Information Center

    Silver, Michael, Ed.; Zito, Michael, Ed.

    2002-01-01

    This document is comprised of the one issue in volume 7 of "Bridges," a publication produced by the California Head Start-State Collaboration Office to detail the activities of the educational partnership and to provide relevant information to programs participating in the partnership. The Summer 2002 issue focuses on several topics of…

  4. Software Bridge

    NASA Technical Reports Server (NTRS)

    1995-01-01

    I-Bridge is a commercial version of software developed by I-Kinetics under a NASA Small Business Innovation Research (SBIR) contract. The software allows users of Windows applications to gain quick, easy access to databases, programs and files on UNIX services. Information goes directly onto spreadsheets and other applications; users need not manually locate, transfer and convert data.

  5. Wheatstone's Bridge

    NASA Astrophysics Data System (ADS)

    Greenslade, Thomas B.

    2005-01-01

    The arrangement of four resistors, a source of emf, and a galvanometer, known as Wheatstone's bridge, has been in existence for more than 170 years. The only other piece of apparatus with its staying power is Atwood's machine. Now that it has reached mature status, it seems only fitting to describe its origin, analysis, circuit topology, and past and future uses.

  6. Bridged graphite oxide materials

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

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

  7. Visual Storyboarding Provides a Conceptual Bridge from Research to Development: Students Can Imagine the Results of Their Decision Making, and Their Prioritization of the Many Facets of the Design Problem Will Facilitate the Development of a Strong Final Solution

    ERIC Educational Resources Information Center

    Reeder, Kevin

    2005-01-01

    In order to facilitate the selection/prioritization process and bridge the gap of design research to design conceptualization, students need to visualize the big picture that describes how the research categories such as "user," "marketing," "functional/mechanical research" are related. This is achieved through the use of a visual storyboard. The…

  8. Design, Synthesis and Antitumor Activity of Novel link-bridge and B-Ring Modified Combretastatin A-4 (CA-4) Analogues as Potent Antitubulin Agents

    PubMed Central

    Duan, Yong-Tao; Man, Ruo-Jun; Tang, Dan-Jie; Yao, Yong-Fang; Tao, Xiang-Xiang; Yu, Chen; Liang, Xin-Yi; Makawana, Jigar A.; Zou, Mei-Juan; Wang, Zhong-Chang; Zhu, Hai-Liang

    2016-01-01

    A series of 12 novel acylhydrazone, chalcone and amide–bridged analogues of combretastatin A-4 were designed and synthesized toward tubulin. All these compounds were determined by elemental analysis, 1H NMR, and MS. Among them, compound 7 with acylhydrazone-bridge, bearing a benzyl at the indole-N position, was identified as a potent antiproliferative agent against a panel of cancer cell lines with IC50 values ranging from 0.08 to 35.6 μM. In contrast, its cytotoxic effects on three normal human cells were minimal. Cellular studies have revealed that the induction of apoptosis by compound 7 was associated with a collapse of mitochondrial membrane potential, accumulation of reactive oxygen species, alterations in the expression of some cell cycle-related proteins (Cyclin B1, Cdc25c, Cdc2, P21) and some apoptosis-related proteins (Bax, PARP, Bcl-2, Caspase3). The docking mode showed the binding posture of CA-4 and compound 7 are similar in the colchicine-binding pocket of tubulin, as confirmed by colchicine-tubulin competitive binding assay, tubulin polymerization inhibitory activity, extracellular protein expression determination assay and confocal immunofluorescence microscopy. In vivo study, compound 7 effectively inhibited A549 xenograft tumor growth without causing significant loss of body weight suggesting that compound 7 is a promising new antimitotic agent with clinical potential. PMID:27138035

  9. 25 CFR 170.507 - Who reviews bridge inspection reports?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Who reviews bridge inspection reports? 170.507 Section... ROADS PROGRAM Planning, Design, and Construction of Indian Reservation Roads Program Facilities Bridge Inspection § 170.507 Who reviews bridge inspection reports? The person responsible for the bridge...

  10. 25 CFR 170.507 - Who reviews bridge inspection reports?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Who reviews bridge inspection reports? 170.507 Section 170... ROADS PROGRAM Planning, Design, and Construction of Indian Reservation Roads Program Facilities Bridge Inspection § 170.507 Who reviews bridge inspection reports? The person responsible for the bridge...

  11. 25 CFR 170.507 - Who reviews bridge inspection reports?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Who reviews bridge inspection reports? 170.507 Section... ROADS PROGRAM Planning, Design, and Construction of Indian Reservation Roads Program Facilities Bridge Inspection § 170.507 Who reviews bridge inspection reports? The person responsible for the bridge...

  12. 25 CFR 170.507 - Who reviews bridge inspection reports?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Who reviews bridge inspection reports? 170.507 Section... ROADS PROGRAM Planning, Design, and Construction of Indian Reservation Roads Program Facilities Bridge Inspection § 170.507 Who reviews bridge inspection reports? The person responsible for the bridge...

  13. 25 CFR 170.507 - Who reviews bridge inspection reports?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Who reviews bridge inspection reports? 170.507 Section... ROADS PROGRAM Planning, Design, and Construction of Indian Reservation Roads Program Facilities Bridge Inspection § 170.507 Who reviews bridge inspection reports? The person responsible for the bridge...

  14. FROM "CANAL BRIDGE, F.A.P. 4C, MAR. 1938." SHOWING WAIKELE BRIDGE ...

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

    FROM "CANAL BRIDGE, F.A.P. 4-C, MAR. 1938." SHOWING WAIKELE BRIDGE PLAN AND ELEVATION. Hawaii Department of Transportation, Design Branch, Project ID 7101-001, drawing 4449.27. - Waikele Canal Bridge and Highway Overpass, Farrington Highway and Waikele Stream, Waipahu, Honolulu County, HI

  15. A perspective on bridging scales and design of models using low-dimensional manifolds and data-driven model inference.

    PubMed

    Tegnér, Jesper; Zenil, Hector; Kiani, Narsis A; Ball, Gordon; Gomez-Cabrero, David

    2016-11-13

    Systems in nature capable of collective behaviour are nonlinear, operating across several scales. Yet our ability to account for their collective dynamics differs in physics, chemistry and biology. Here, we briefly review the similarities and differences between mathematical modelling of adaptive living systems versus physico-chemical systems. We find that physics-based chemistry modelling and computational neuroscience have a shared interest in developing techniques for model reductions aiming at the identification of a reduced subsystem or slow manifold, capturing the effective dynamics. By contrast, as relations and kinetics between biological molecules are less characterized, current quantitative analysis under the umbrella of bioinformatics focuses on signal extraction, correlation, regression and machine-learning analysis. We argue that model reduction analysis and the ensuing identification of manifolds bridges physics and biology. Furthermore, modelling living systems presents deep challenges as how to reconcile rich molecular data with inherent modelling uncertainties (formalism, variables selection and model parameters). We anticipate a new generative data-driven modelling paradigm constrained by identified governing principles extracted from low-dimensional manifold analysis. The rise of a new generation of models will ultimately connect biology to quantitative mechanistic descriptions, thereby setting the stage for investigating the character of the model language and principles driving living systems.This article is part of the themed issue 'Multiscale modelling at the physics-chemistry-biology interface'.

  16. A perspective on bridging scales and design of models using low-dimensional manifolds and data-driven model inference

    PubMed Central

    Zenil, Hector; Kiani, Narsis A.; Ball, Gordon; Gomez-Cabrero, David

    2016-01-01

    Systems in nature capable of collective behaviour are nonlinear, operating across several scales. Yet our ability to account for their collective dynamics differs in physics, chemistry and biology. Here, we briefly review the similarities and differences between mathematical modelling of adaptive living systems versus physico-chemical systems. We find that physics-based chemistry modelling and computational neuroscience have a shared interest in developing techniques for model reductions aiming at the identification of a reduced subsystem or slow manifold, capturing the effective dynamics. By contrast, as relations and kinetics between biological molecules are less characterized, current quantitative analysis under the umbrella of bioinformatics focuses on signal extraction, correlation, regression and machine-learning analysis. We argue that model reduction analysis and the ensuing identification of manifolds bridges physics and biology. Furthermore, modelling living systems presents deep challenges as how to reconcile rich molecular data with inherent modelling uncertainties (formalism, variables selection and model parameters). We anticipate a new generative data-driven modelling paradigm constrained by identified governing principles extracted from low-dimensional manifold analysis. The rise of a new generation of models will ultimately connect biology to quantitative mechanistic descriptions, thereby setting the stage for investigating the character of the model language and principles driving living systems. This article is part of the themed issue ‘Multiscale modelling at the physics–chemistry–biology interface’. PMID:27698038

  17. An Investigation of the Relative Safety of Alternative Navigational System Designs for the New Sunshine Skyway Bridge: A CAORF (Computer Aided Operations Research Facility) Simulation.

    DTIC Science & Technology

    1985-09-01

    characteristics. Pilots were required to provided no added margin of safety beyond the bridge - use greater crab angles during thunderstorm scenarios...electronic navigation aids may would combine dolphins, complete island and horseshoe . "provide significantly improved navigational data" to island stuctures...The next two bridge piers on should not be so close to bridges that the success of navigat- either side would be protected by a horseshoe shaped ing

  18. Three Dimensional Analysis of the Final Design of Pier Extensions and West Guide Wall to Mitigate Local Scour Risk at the BNSF Railroad Bridge Downstream of the Prado Dam Supplemental Report

    SciTech Connect

    Lottes, S. A.; Sinha, N.; Bojanowski, C.; Kerenyi, K.; Sharp, Jeremy

    2016-06-01

    This report is a supplement to a previous report [ref] covering optimization of wedge shaped pier extensions to streamline large bluff body piers as a local scour countermeasure for the Burlington Northern and Santa Fe (BNSF) Railroad Bridge over the Santa Ana River downstream of Prado Dam in Riverside County, CA. The optimized design was tested in a 1/30 scale physical model at U.S. Army Engineer Research and Development Center (ERDC) in Vicksburg, MS, and the optimized design was used as the base for the construction design. Constructability issues having to do with both materials and site conditions including access underneath the BNSF bridge yielded a construction design that required making the pier extensions wider and either moving the western curve of the west guide wall upstream or changing its geometry.

  19. Bridging the Field Trip Gap: Integrating Web-Based Video as a Teaching and Learning Partner in Interior Design Education

    ERIC Educational Resources Information Center

    Roehl, Amy

    2013-01-01

    This study utilizes web-based video as a strategy to transfer knowledge about the interior design industry in a format that interests the current generation of students. The model of instruction developed is based upon online video as an engaging, economical, and time-saving alternative to a field trip, guest speaker, or video teleconference.…

  20. Design, development and characterization of an x-band 5 bit DMTL phase shifter using an inline MEMS bridge and MAM capacitors

    NASA Astrophysics Data System (ADS)

    Dey, Sukomal; Koul, Shiban K.

    2014-09-01

    A radio frequency micro-electro-mechanical system (RF-MEMS) 5 bit phase shifter based on a distributed MEMS transmission line concept with excellent phase accuracy and good repeatability is presented in this paper. The phase shifter is built with three fixed-fixed beams; one is switchable with electrostatic actuation and the other two are fixed for a metal-air-metal (MAM) capacitor. The design is based on a coplanar waveguide (CPW) configuration using alumina substrate. Gold-based surface micromachining is used to develop the individual primary phase bits (11.25°/22.5°/45°/90°/180°), which are fundamental building blocks of the complete 5 bit phase shifter. All of the primary phase bits are cascaded together to build the complete phase shifter. Detailed design methodology and performance analysis of the unit cell phase shifter has been carried out with structural and parametric optimization using an in-line bridge and MAM capacitors. The mechanical, electrical, transient, intermodulation distortion (IMD), temperature distribution, power handling and loss performances of the MEMS bridge have been experimentally obtained and validated using simulations up to reasonable extent. A single unit cell is able to provide 31 dB return loss, maximum insertion loss of 0.085 dB and a differential phase shift of 5.95° (at 10 GHz) over the band of interest. Furthermore, all primary phase bits are individually tested to ensure overall optimum phase shifter performance. The complete 5 bit phase shifter demonstrates an average insertion loss of 4.72 dB with return loss of better than 12 dB within 8-12 GHz using periodic placement of 62 unit cells and a maximum phase error of ±3.2° has been obtained at 10 GHz. Finally, the x-band 5 bit phase shifter is compared with the present state-of-the-art. The performance of the 5 bit phase shifter when mounted inside a test jig has been experimentally investigated and the results are presented. The total area of

  1. Bridging the ';knowing and doing gap' in disaster risk reduction using design and design thinking; Ideation of concepts to improve hazard preparedness and response

    NASA Astrophysics Data System (ADS)

    van Manen, S. M.

    2013-12-01

    The central goal of disaster risk reduction (DRR) is to reduce the impact and cost of natural hazards, in human, environmental and economic terms. There are numerous approaches that aim to achieve this but recent studies have shown a substantial gap between risk reduction actions taken at national and local levels. The traditional media of the scientist: education, outreach and increasingly community involvement, have been shown to raise levels of awareness and understanding but generate little change in terms of people's actions. This can be attributed to the differences in hazard perception and the relative weight placed on various aspects by scientists, authorities and communities as a result of non-hazard related factors. Therefore DRR, particularly when placed in its social, environmental and economic contexts, is an excellent example of what is termed a ';wicked problem': a problem that is difficult to formulate, where data to base decisions on are incomplete, the stakeholders are many and they hold contradicting views and the consequences of actions on the wider system are unclear. Although both science and design are geared towards problem solving, design, in drawing equally on art and engineering skills, does so in a fundamentally different but complementary way. Neither design nor science will solve the wicked problem that is DRR, but scientists, engineers and designers can improve the current state of disaster risk reduction by tackling aspects of underlying risk factors. This work will present concepts aimed at engaging people in novel and innovative ways with scientific results, with a specific focus on improving hazard preparedness and tangible, rather than abstract, ways of communicating hazard levels. Key considerations include the need to graft onto existing behaviours or innovate on existing products to simplify implementation, the possibility to co-create and connect through design and balancing desirability with technical and economical

  2. WSC Bridge Program Planning Guide

    ERIC Educational Resources Information Center

    Jenkins, Davis

    2004-01-01

    Increasingly jobs that pay more than subsistence wages and offer opportunities for career advancement require at least some training beyond high school, even at the entry level. Bridge training programs are designed to prepare individuals without the requisite basic skills for postsecondary training leading to career-path employment and further…

  3. Optimization of cable preloading on cable-stayed bridges

    NASA Astrophysics Data System (ADS)

    Wang, Yang Cheng; Vlahinos, Andreas S.; Shu, HungShan

    1997-05-01

    Generally, geometric nonlinearities of cable-stayed bridges depend on the behaviors of cables, pylons, the bridge deck and their interactions. These are geometry change, cable sag, and the interactions of axial forces, the bending moment and their deformations in the pylons and bridge deck. Therefore, a large cable-stayed bridges system having a large number of cables can be analyzed under different load conditions. In investigating nonlinear behaviors of cable- stayed bridges, the nonlinear behavior of cables needs to be considered because it may cause the nonlinear behavior of whole bridge system. The nonlinear behavior of a cable gained from its sag. With an increasing axial load, the elongation of the cable is increased but the total cable sag is decreased. Cable-stayed bridge uses cables instead of the internal piers to support the bridge deck. Usually, cable- stayed bridge decks are straight with a little camber compared to the total length of the bridge. Keeping the bridge deck in the position where is the designer desired is not only for bridge aesthetics but also for people on the bridge in terms of psychological effect of improving confidence in structure and engineering considerations. To achieve the serviceability and engineering requirements, preloading of the cable is necessary. In this paper, one such a bridge with geometry similarly to an existing cable- stayed bridge. Quincy Bayview Bridge, located in Illinois, USA, has been considered. Quincy Bayview Bridge has 58 cables in the two planes. Four methods have been considered in this paper to make the optimum selection of cable preloading. The objective is to select appropriate method to determine cable prestrains in order to minimize the deformations and stresses due to dead load of the bridge. Thus, it is not a trivial problem since a change in the prestress of a cable influence the deformation every where in the structure. The best method would be determined by comparing the calculated bending and

  4. A data management infrastructure for bridge monitoring

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  5. 12. DETAIL VIEW OF BRIDGE, SHOWING SPRING LINE OF SPANS ...

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

    12. DETAIL VIEW OF BRIDGE, SHOWING SPRING LINE OF SPANS FROM CROWN OF MID-CHANNEL PIER, PAIRED COLUMNS SUPPORTING DECK, ARCHED WINDOW RAILING, LOOKING WEST-NORTHWEST FROM EUREKA SOUTHERN RAILROAD BRIDGE. CABLES VISIBLE IN BACKGROUND ARE EARTHQUAKE RESTRAINERS RETROFITTED TO 1952 HIGHWAY BRIDGE, WHICH FUNCTIONED AS DESIGNED IN APRIL 1992 TEMBLOR - Van Duzen River Bridge, Spanning Van Duzen River at CA State Highway 101, Alton, Humboldt County, CA

  6. Liquid bridges with thermocapillarity

    NASA Technical Reports Server (NTRS)

    Xu, J.-J.; Davis, S. H.

    1983-01-01

    An axisymmetric liquid bridge is subjected to an axial temperature gradient. Thermal variations in surface tension drive a motion that is described using lubrication theory for slender bridges. At leading order in aspect ratio, a class of similarity solutions is obtained valid in the core region away from the endwalls of the bridge. These solutions describe the flows, temperature fields, and interfacial shapes of bridges that may sustain substantial interfacial deflections.

  7. Halliburton Composite Bridge Plug Assembly

    SciTech Connect

    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.

  8. Radar tomography of bridge decks

    NASA Astrophysics Data System (ADS)

    Davidson, Nigel C.; Chase, Steven B.

    1998-03-01

    This paper presents the development of ground-penetrating radar bridge deck inspection systems sponsored by the Federal Highway Administration. Two radar systems have been designed and built by Lawrence Livermore National Laboratory. The HERMES bridge inspector (High-speed Electromagnetic Roadway Mapping and Evaluation System) is designed to survey the deck condition during normal traffic flow. Thus the need for traffic control during inspection is eliminated. This system employs a 64 channel antenna array covering 1.9 m in width with a sampling density of 3 cm. To investigate areas of a bridge deck that are of particular interest and require detailed inspection a slower, cart mounted radar has been produced. This system is named PERES (Precision Electromagnetic Roadway Evaluation System). The density of data coverage with PERES is 1 cm and an average or 100 samples is taken at each location to improve the signal to noise ratio. Images of the deck interior are reconstructed from the original data using synthetic aperture tomography. The target of these systems is the location of steel reinforcement, corrosion related delaminations, voids and disbonds. The final objective is for these, and other non-destructive technologies, to provide information on the condition of the nation's bridges so that funds will be spent on the structures in most need of repair.

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

    PubMed

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

    2013-11-08

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

  10. [M(III)(bpym)(CN)(4)](-): a suitable building block to design ferrimagnetic cyano-bridged heterobimetallic chains (M = Fe, Cr; bpym = 2,2'-bypyrimidine).

    PubMed

    Visinescu, Diana; Toma, Luminita Marilena; Lloret, Francesc; Fabelo, Oscar; Ruiz-Pérez, Catalina; Julve, Miguel

    2008-08-21

    Two cyano-bridged M(III)Mn(III) [M = Fe () and Cr ()] ferrimagnetic chains are reported; exhibits metamagnetism with two critical fields of 1250 G and 2.0 T which correspond to the overcoming by the applied dc field of the inter- and intrachain magnetic interactions, respectively.

  11. Strategy for structural identification of highway bridges

    NASA Astrophysics Data System (ADS)

    Chalko, Tom J.; Haritos, Nicholas

    1996-11-01

    The University of Melbourne in collaboration with VicRoads, the road and bridge authority in the state of Victoria, has performed a series of static and dynamic tests to evaluate the in-service condition of a number of bridges of different design. From this experience, a strategy for a routine bridge testing procedure has emerged, the presentation of which is the main subject of this paper. The strategy presented involves the selective use of the following methods and techniques: 1) Measurements: vibration response to ambient/traffic excitation, Modal Testing using impact deices and/or shakers. 2) Modal parameter estimation from experimental measurements. 3) FEM modeling: development of generic parametric FEM models of standard/typical designs, and special models. 4) Correlating FEM models and experimental results: updating FEM model parameters, identification of bridge support conditions, estimation of effective stiffness of aged materials and structural elements. 5) Detection of structural faults: simple methods and advanced techniques if required. 6) Prediction of bridge load carrying capacity using verified FEM model: use in re- rating bridges and as a basis or a substitute for proof load testing. The outline of the strategy together with a brief description of the elements above is given. The motivation for the work presented in this paper was to select the state of the art engineering tools to assist relevant authorities in the decision processes necessary for implementing a cost- effective maintenance and replacement policy for the ageing bridge stock.

  12. Physeal bridge resection.

    PubMed

    Khoshhal, Khalid I; Kiefer, Gerhard N

    2005-01-01

    Growth arrest secondary to physeal bridge formation is an uncommon but well-recognized complication of physeal fractures and other injuries. Regardless of the underlying etiology, physeal bridges may cause angular and/or longitudinal growth disturbances, with progression dependent on the remaining physeal growth potential. Physeal bridge resection and insertion of interposition material releases the tethering effect of the bridge. Physeal bridge resection has become an accepted treatment option for patients with existing or developing deformity and for those with at least 2 years or 2 cm of growth remaining. Current experimental research is focused on the use of gene therapy and other factors that enhance chondrocyte proliferation to improve the management of growth arrest. The use of cartilage and cultured chondrocytes as interposition material after physeal bridge resection is an area of active research.

  13. Bridge Crossing Simulator

    DTIC Science & Technology

    2014-10-07

    reaction structure, and a control system, the BCS physically simulates vehicular crossing loads for the expected life span of the bridge undergoing...information provided by the customer. In general, statics will be used to determine equations for moments and deflections based on the specific bridge ...systems. Through the use of hydraulic actuators, a reaction structure, and a control system, the Bridge Crossing Simulator physically simulates vehicular

  14. 49 CFR 237.57 - Designations of individuals.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons... railroad bridge engineers, railroad bridge inspectors and railroad bridge supervisors. Each...

  15. Semiconductor bridge (SCB) detonator

    DOEpatents

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

    1999-01-01

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

  16. Semiconductor bridge (SCB) detonator

    DOEpatents

    Bickes, R.W. Jr.; Grubelich, M.C.

    1999-01-19

    The present invention is a low-energy detonator for high-density secondary-explosive materials initiated by a semiconductor bridge (SCB) igniter that comprises a pair of electrically conductive lands connected by a semiconductor bridge. The semiconductor bridge is in operational or direct contact with the explosive material, whereby current flowing through the semiconductor bridge causes initiation of the explosive material. Header wires connected to the electrically-conductive lands and electrical feed-throughs of the header posts of explosive devices, are substantially coaxial to the direction of current flow through the SCB, i.e., substantially coaxial to the SCB length. 3 figs.

  17. LOOKING WEST, BETWEEN READING DEPOT BRIDGE AND SKEW ARCH BRIDGE ...

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

    LOOKING WEST, BETWEEN READING DEPOT BRIDGE AND SKEW ARCH BRIDGE (HAER No. PA-116). - Philadelphia & Reading Railroad, Reading Depot Bridge, North Sixth Street at Woodward Street, Reading, Berks County, PA

  18. 1. Claremont Railway Bridge, Main Street Bridge, and Clement and ...

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

    1. Claremont Railway Bridge, Main Street Bridge, and Clement and Rossiter Store in context, looking west - Claremont Railway Bridge, Spanning Sugar River at Claremont Railroad Company Line, Claremont, Sullivan County, NH

  19. 32. DETAIL OF BRIDGE COUNTERWEIGHTS AND SUSPENSION STRUCTURE BETWEEN BRIDGE ...

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

    32. DETAIL OF BRIDGE COUNTERWEIGHTS AND SUSPENSION STRUCTURE BETWEEN BRIDGE NOS. 12 AND 13. LOOKING EAST-SOUTHEAST. - Greenville Yard, Transfer Bridge System, Port of New York/New Jersey, Upper New York Bay, Jersey City, Hudson County, NJ

  20. GOETHALS BRIDGE FROM NORTH SIDE OVER ARTHUR KILL. RAILROAD BRIDGE ...

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

    GOETHALS BRIDGE FROM NORTH SIDE OVER ARTHUR KILL. RAILROAD BRIDGE IN FOREGROUND - Goethals Bridge, Spanning Arthur Kill from New Jersey to Staten Island, Staten Island (subdivision), Richmond County, NY

  1. 10. DETAIL VIEW OF BRIDGE DATEPLATE WHICH READS 'WISCONSIN BRIDGE ...

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

    10. DETAIL VIEW OF BRIDGE DATEPLATE WHICH READS 'WISCONSIN BRIDGE & IRON COMPANY, MILWAUKEE, WIS., 1933' - St. Francis River Bridge, Spanning St. Francis River at U.S. Highway 70, Forrest City, St. Francis County, AR

  2. 2. LONG VIEW NORTHWEST, EASTBOUND BRIDGE IN FOREGROUND, WESTBOUND BRIDGE ...

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

    2. LONG VIEW NORTHWEST, EASTBOUND BRIDGE IN FOREGROUND, WESTBOUND BRIDGE IN BACKGROUND - Willow Run Expressway Bridge No. R01, Spanning Conrail Railway, eastbound, at US-10, Ypsilanti, Washtenaw County, MI

  3. Plans: Poop Deck, Boat Deck, Housetop, Bridge Deck, Upper Bridge ...

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

    Plans: Poop Deck, Boat Deck, Housetop, Bridge Deck, Upper Bridge Deck, Navigating Bridge, Forecastle Deck, Upper Deck, Second Deck and Hold - Saugatuck, James River Reserve Fleet, Newport News, Newport News, VA

  4. 3. View of Clark Fork Vehicle Bridge facing southwest. Bridge ...

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

    3. View of Clark Fork Vehicle Bridge facing southwest. Bridge from north shore of Clark Fork River. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

  5. 7. View of Clark Fork Vehicle Bridge facing northwest. Bridge ...

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

    7. View of Clark Fork Vehicle Bridge facing northwest. Bridge from south shore of Clark Fork River showing 4 1/2 spans. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

  6. 4. View of Clark Fork Vehicle Bridge facing northeast. Bridge ...

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

    4. View of Clark Fork Vehicle Bridge facing northeast. Bridge from south shoreof Clark Fork River showing 4 spans. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

  7. 2. View of Clark Fork Vehicle Bridge facing northeast. Bridge ...

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

    2. View of Clark Fork Vehicle Bridge facing northeast. Bridge from south shore of Clark Fork River showing 4 1/2 spans. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

  8. APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN ...

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

    APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN FROM ENTRY. VIEW FACING NORTHWEST - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower Foot Bridge, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

  9. APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN ...

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

    APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN FROM BELOW, SHOWING VALVE TOWER TO RIGHT. VIEW FACING NORTH - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower Foot Bridge, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

  10. LODGEPOLE BRIDGE, FACING NORTHWEST Generals Highway, Lodge Pole Bridge, ...

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

    LODGEPOLE BRIDGE, FACING NORTHWEST - Generals Highway, Lodge Pole Bridge, Spanning Marble Fork of Kaweah River, approximately 21 miles northwest of Ash Mountain Entrance, Three Rivers, Tulare County, CA

  11. LODGEPOLE BRIDGE, FACING SOUTHEAST Generals Highway, Lodge Pole Bridge, ...

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

    LODGEPOLE BRIDGE, FACING SOUTHEAST - Generals Highway, Lodge Pole Bridge, Spanning Marble Fork of Kaweah River, approximately 21 miles northwest of Ash Mountain Entrance, Three Rivers, Tulare County, CA

  12. Precision bolometer bridge

    NASA Technical Reports Server (NTRS)

    White, D. R.

    1968-01-01

    Prototype precision bolometer calibration bridge is manually balanced device for indicating dc bias and balance with either dc or ac power. An external galvanometer is used with the bridge for null indication, and the circuitry monitors voltage and current simultaneously without adapters in testing 100 and 200 ohm thin film bolometers.

  13. Active-bridge oscillator

    DOEpatents

    Wessendorf, Kurt O.

    2001-01-01

    An active bridge oscillator is formed from a differential amplifier where positive feedback is a function of the impedance of one of the gain elements and a relatively low value common emitter resistance. This use of the nonlinear transistor parameter h stabilizes the output and eliminates the need for ALC circuits common to other bridge oscillators.

  14. Bridging the Development Gap.

    DTIC Science & Technology

    1999-11-01

    Bridging the Development Gap is contractual cooperative agreement between Mercury Computer Systems, Inc. and DARPA. This program was developed...processing, interfacing with I/O devices, memory constraints, as well as real-time throughput and latency challenges. Mercury has bridged the indicated

  15. BRIDGES BETWEEN MICROTUBULES

    PubMed Central

    McIntosh, J. R.

    1974-01-01

    Bridges between microtubules have been studied with the electron microscope in the axostyle of Saccinobaculus and in various tubule systems of chicken testis, including the helix of tubules surrounding the elongating spermatid nucleus and the flagellum of the sperm tail. In addition to the previously described periodic bridges, evidence is presented that nonperiodic bridges exist between certain tubules. An analysis of axial spacing between adjacent nonperiodic bridges suggests that these structures are attached to periodic binding sites on the microtubule wall, but that not all the binding sites are filled. The bridges appear nonperiodic as a result of random occupancy of some fraction of the periodic sites. The distribution of these binding sites is related to the substructure of the microtubule wall as seen with negative staining and optical diffraction. PMID:4132065

  16. Test and evaluation plan for the composite bridge

    SciTech Connect

    Rodriguez, J.G.; Dumlao, C.; Ciolko, A.T.; Pfister, T.J.; Schmeckpeper, E.R.

    1997-04-01

    Polymer matrix composites (PMC) are entering the nation`s infrastructure as alternatives to conventional materials. Working with the Federal Highway Administration and Department of Energy, the Idaho National Engineering and Environmental Laboratory is testing and evaluating a PMC structure for use in bridge rehabilitation and replacement. A 30-foot PMC bridge, designed and built by Lockheed Martin Missile and Space, will be field tested in Idaho. The design of this bridge represents simple support bridges in the 120-foot span category. This report describes the construction, transportation, installation, testing, and material properties for this PMC structure.

  17. Rational design of two bpy-bridged 3D and 2D Co(II) open frameworks with similar amino-acid-based Schiff bases.

    PubMed

    Li, Zong-Ze; Du, Lin; Zhou, Jie; Zhu, Ming-Rong; Qian, Fen-Hua; Liu, Jing; Chen, Peng; Zhao, Qi-Hua

    2012-12-21

    Two novel bpy-bridged Co(II) Schiff base complexes have been synthesized by the hydro(solvo)thermal reactions of corresponding amino-acid-based Schiff bases, bpy and Co(NO(3))(2)·6H(2)O. The following formulae identify the two complexes: {[Co(napala)(bpy)(0.5)]·H(2)O}(n) (1) and [Co(napgly)(bpy)(0.5)](n) (2) [H(2)napala = N-(2-hydroxy-1-naphthylmethylidene)-D/L-alanine, H(2)napgly = N-(2-hydroxy-1-naphthylmethylidene)-glycine and bpy = 4,4'-bipyridine]. These two compounds have been characterized using single-crystal X-ray diffraction, infrared, powder X-ray diffraction, thermogravimetric analysis, optical spectra analysis, and magnetic measurement. Complex 1 features an unprecedented threefold interpenetrated diamond network based on the fan-shaped Co(II)(4)(μ(2)-napala)(4) molecular square node and bpy linker, which represents the first example of 3D framework among the amino-acid-based Schiff base complexes with salicylaldehyde or its derivatives. In 2, adjacent Co(II) ions are bridged by μ(2)-napgly(2-) to form left- and right-handed [Co(II)(μ(2)-napgly)](n) helical chains. These two types of helical chains are sustained alternately by a symmetrical bpy co-ligand into a 2D grid-based layer. The solid-state fluorescence of complexes 1 and 2 are quenched almost completely compared with free mixed-ligands at room temperature. Moreover, magnetic studies show the dominant antiferromagnetic coupling between the Co(II) centers mediated by the syn-anti-COO(-)-bridges in both complexes.

  18. Bridging Spans the Gaps in Project Delivery.

    ERIC Educational Resources Information Center

    Heery, George T.

    2002-01-01

    Discusses the advantages of "bridging," a hybrid project delivery approach that uses an owner's design architect and program manager to prepare preliminary design and specification documents, and then has this team closely supervise the contractor's architect and engineers in finalizing the construction documents. (EV)

  19. Design and selection of nitrogen-rich bridged di-1,3,5-triazine derivatives with high energy and reduced sensitivity.

    PubMed

    Pan, Yong; Zhu, Weihua; Xiao, Heming

    2012-07-01

    The heats of formation (HOFs), electronic structures, energetic properties, and thermal stabilities of a series of energetic bridged di-1,3,5-triazine derivatives with different substituents and linkages were studied using density functional theory. It was found that the groups -N(3) and -N=N- are effective structural units for improving the HOF values of the di-1,3,5-triazine derivatives. The effects of the substituents on the HOMO-LUMO gap combine with those of the bridge groups. The calculated detonation velocities and detonation pressures indicate that substituting the -ONO(2), -NF(2), or -N=N- group is very useful for enhancing the detonation performance of these derivatives. Analysis of the bond dissociation energies for several relatively weak bonds suggests that most of the derivatives have good thermal stability. On the whole, the -NH(2), -N(3), -NH-, and -CH=CH- groups are effective structural units for increasing the thermal stabilities of the derivatives. Based on detonation performance and thermal stability, nine of the compounds can be considered potential candidates for high energy density materials with reduced sensitivity.

  20. Design, fabrication, and characterization of bridge-type micro-hotplates with an SU-8 supporting layer for a smart gas sensing system

    NASA Astrophysics Data System (ADS)

    Iwata, T.; Soo, W. P. C.; Matsuda, K.; Takahashi, K.; Ishida, M.; Sawada, K.

    2017-02-01

    In this study, bridge-type micro-hotplates (MHP) with an SU-8 supporting layer were proposed for smart gas sensor applications. The proposed MHP consisted of a heating membrane with an area of 140 µm  ×  140 µm, and a 33 µm-thick SU-8 layer deposited on its bridges. Finite element method based simulation confirmed that the proposed MHP displayed good thermal isolation properties. The proposed MHP was successfully fabricated, and the properties of the MHP were characterized. Current-voltage characteristics revealed that the MHP temperature can reach 550 °C at 5 V. The temperature of the MHP was calculated from changes in the resistance of the heater. Power consumption of the MHP approximately corresponded to 13.9 mW for heating to 300 °C. This was comparable to the power consumption reported in the previous studies. Furthermore, a stable operation under a constant voltage was observed for 100 min. The properties of the MHP indicated that it could potentially be utilized for applications related to integrated gas sensors.

  1. 49 CFR 237.131 - Design.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Design. 237.131 Section 237.131 Transportation... TRANSPORTATION BRIDGE SAFETY STANDARDS Repair and Modification of Bridges § 237.131 Design. Each repair or... component of a bridge shall be designed by a railroad bridge engineer. The design shall specify the...

  2. 49 CFR 237.131 - Design.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Design. 237.131 Section 237.131 Transportation... TRANSPORTATION BRIDGE SAFETY STANDARDS Repair and Modification of Bridges § 237.131 Design. Each repair or... component of a bridge shall be designed by a railroad bridge engineer. The design shall specify the...

  3. 49 CFR 237.131 - Design.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Design. 237.131 Section 237.131 Transportation... TRANSPORTATION BRIDGE SAFETY STANDARDS Repair and Modification of Bridges § 237.131 Design. Each repair or... component of a bridge shall be designed by a railroad bridge engineer. The design shall specify the...

  4. 49 CFR 237.131 - Design.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Design. 237.131 Section 237.131 Transportation... TRANSPORTATION BRIDGE SAFETY STANDARDS Repair and Modification of Bridges § 237.131 Design. Each repair or... component of a bridge shall be designed by a railroad bridge engineer. The design shall specify the...

  5. 49 CFR 237.131 - Design.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Design. 237.131 Section 237.131 Transportation... TRANSPORTATION BRIDGE SAFETY STANDARDS Repair and Modification of Bridges § 237.131 Design. Each repair or... component of a bridge shall be designed by a railroad bridge engineer. The design shall specify the...

  6. 5. View of Clark Fork Vehicle Bridge facing east. Bridge ...

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

    5. View of Clark Fork Vehicle Bridge facing east. Bridge from south shore of Clark Fork River-southernmost span. 1900-era Northern Pacific Railway Bridge in background. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

  7. The Interstate-40 bridge shaker project

    SciTech Connect

    Mayes, R.L.; Nusser, M.A.

    1994-04-01

    New Mexico State University organized an effort to perform static and dynamic damage-detection tests on the Interstate-40 bridge over the Rio Grande at Albuquerque. The opportunity was available because the 425-ft-long bridge was soon to be replaced. Sandia National Laboratories was asked to provide and operate a shaker that could exert 1000-lb peak amplitude forces for both sinusoidal and random excitations between 2 and 20 Hz. Two Sandia departments collaborated to design and build the shaker, using existing major components connected with Sandia-designed and -fabricated hardware. The shaker was installed and operated successfully for a series of five modal and sinusoidal response tests.

  8. Bridging the Gap between User Experience Research and Design in Industry: An Analysis of Two Common Communication Tools--Personas and Scenarios

    ERIC Educational Resources Information Center

    Putnam, Cynthia

    2010-01-01

    User experience (UX) research in the design of technology products utilizes human-centered design (HCD) methods to summarize and explain pertinent information about end users to designers. However, UX researchers cannot effectively communicate the needs and goals of users if designers do not find UX research (a) easy to integrate into design…

  9. Mineral bridges in nacre.

    PubMed

    Checa, Antonio G; Cartwright, Julyan H E; Willinger, Marc-Georg

    2011-12-01

    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 (150-200nm) 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 (>100nm) 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 (<60nm), earlier reported to be mineral bridges, found to be such.

  10. Bridging Humanism and Behaviorism.

    ERIC Educational Resources Information Center

    Chu, Lily

    1980-01-01

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

  11. I-5/Gilman advanced technology bridge project

    NASA Astrophysics Data System (ADS)

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

    2000-04-01

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

  12. Standard plans for southern pine bridges. Forest Service general technical report

    SciTech Connect

    Hilbrich Lee, P.D.; Ritter, M.A.; Triche, M.

    1995-09-01

    This publication contains standardized designs and details for three timber bridge superstructure types, including stress-laminated sawn lumber bridges, stress laminated glued laminated timber (glulam) bridges, and longitudinal sawn lumber stringer bridges with transverse plank decks. Each set of plans encompasses numerous span length and width combinations, design loadings for AASHTO HS 20-44 and HS 25-44 vehicles, and two options for live-load deflection criteria.

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  14. Summer Bridge Programs. What Works Clearinghouse Intervention Report

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2016

    2016-01-01

    "Summer bridge programs" are designed to ease the transition to college and support postsecondary success by providing students with the academic skills and social resources needed to succeed in a college environment. These programs occur in the summer "bridge" period between high school and college. Although the content of…

  15. Developmental Summer Bridge Programs. What Works Clearinghouse™ Intervention Report

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2015

    2015-01-01

    Developmental summer bridge programs are designed to reduce the need for developmental education in college by providing students with accelerated instruction in areas where additional knowledge and skills are needed to help them succeed in higher education. The WWC identified one study of developmental summer bridge programs that meets WWC…

  16. 6. VIEW OF BRIDGE COMMEMORATIVE PLAQUE WHICH STATES '1908, J. ...

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

    6. VIEW OF BRIDGE COMMEMORATIVE PLAQUE WHICH STATES '1908, J. H. CROOKS, ED. ELLIS, A. S. LELAND, COMMISSIONERS. L. E. BRELSFORD, AUDITOR. L. WEST, SURVEYOR. - B. C. GERWICK, DESIGNER. F. E. WITHCOTT, ENG. ON CONST. C. A. WARNER, CONTRACTOR.' - First Street Reinforced Concrete Bridge, Spanning Moxahala Creek at First Street (CR 7), Roseville, Muskingum County, OH

  17. Fibre reinforced composite dental bridge. Part II: Numerical investigation.

    PubMed

    Li, W; Swain, M V; Li, Q; Ironside, J; Steven, G P

    2004-09-01

    Motivated by the clinical success and limitations on experimental investigation of the fibre-reinforced composite dental bridge, this paper aims at providing a numerical investigation into the bridge structure. The finite element (FE) model adopted here is constructed from computer tomography images of a physical bridge specimen. The stress and strain distributions in the bridge structure especially in the bonding interfaces are analyzed in detail. The peak stresses and their variations with the different bridge designs are evaluated. Due to the lower bond strengths of adhesives and the high stress concentration in the pontic-abutment interface, the likelihood of failure in the interface is predicted by finite element analysis. The validity of the numerical results is established by a good agreement between the FE prediction and the tests in the load-deflection responses, the structural stiffness as well as the failure location of the composite dental bridge.

  18. Bridging the Educational Research-Teaching Practice Gap: Curriculum Development, Part 1--Components of the Curriculum and Influences on the Process of Curriculum Design

    ERIC Educational Resources Information Center

    Anderson, Trevor R.; Rogan, John M.

    2011-01-01

    This article summarizes the major components of curriculum design: vision, operationalization of the vision, design, and evaluation. It stresses that the relationship between these components is dynamic, and that the process of curriculum design does not proceed via a linear application of these components. The article then summarizes some of the…

  19. Bridging the educational research-teaching practice gap. Curriculum development, Part 1: Components of the curriculum and influences on the process of curriculum design.

    PubMed

    Anderson, Trevor R; Rogan, John M

    2011-01-01

    This article summarizes the major components of curriculum design: vision, operationalization of the vision, design, and evaluation. It stresses that the relationship between these components is dynamic, and that the process of curriculum design does not proceed via a linear application of these components. The article then summarizes some of the major influences on curriculum design: policy, local context, societal expectations, research trends, and technology. Then, it provides examples of how these influences affect the design of a curriculum and ends with a comprehensive set of questions that instructors could use to guide their curriculum development process.

  20. Investigation of Aerodynamic Interference of Double Deck Bridges

    SciTech Connect

    Sitek, M. A.; Bojanowski, C.; Lottes, S. A.

    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

  1. Smart suspension systems for bridge-friendly vehicles

    NASA Astrophysics Data System (ADS)

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

    2002-06-01

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

  2. Three Dimensional Analysis of Pier Extension and Guide Wall Design Alternatives to Mitigate Local Scour Risk at the BNSF Railroad Bridge Downstream of the Prado Dam

    SciTech Connect

    Lottes, S. A.; Bojanowski, C.; Sinha, N.; Kerenyi, K

    2015-03-01

    The primary objectives of the computational fluid dynamics (CFD) analysis are (1) to verify that the design concept of using wedge shaped pier extensions to divert flow around piers as a scour counter measure has the intended effect on the flow, (2) to refine the design of the length and orientation of the pier extensions within the channel and (3) to optimize the guide walls that will protect a set of outer piers and the abutments on each side of the channel. The original proposed design is shown in Figure 1.3. The results of this effort are the recommended designs that are judged to be the best designs based on results from the set of test cases run combined with engineering judgment. The refined designs from the CFD analysis are expected to be tested in a limited set of physical model experiments to verify that they work well.

  3. The Memory Bridge Initiative on Service Learners

    ERIC Educational Resources Information Center

    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…

  4. Comparison of aerodynamic characteristics of pentagonal and hexagonal shaped bridge decks

    NASA Astrophysics Data System (ADS)

    Haque, Md. Naimul; Katsuchi, Hiroshi; Yamada, Hitoshi; Nishio, Mayuko

    2016-07-01

    Aerodynamics of the long-span bridge deck should be well understood for an efficient design of the bridge system. For practical bridges various deck shapes are being recommended and adopted, yet not all of their aerodynamic behaviors are well interpreted. In the present study, a numerical investigation was carried out to explore the aerodynamic characteristics of pentagonal and hexagonal shaped bridge decks. A relative comparison of steady state aerodynamic responses was made and the flow field was critically analyzed for better understanding the aerodynamic responses. It was found that the hexagonal shaped bridge deck has better aerodynamic characteristics as compared to the pentagonal shaped bridge deck.

  5. The Bridge of Mandolin County

    NASA Astrophysics Data System (ADS)

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

    1999-12-01

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

  6. Planar Hall effect bridge magnetic field sensors

    SciTech Connect

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

    2010-07-05

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

  7. Fibre reinforced composite dental bridge. Part I: Experimental investigation.

    PubMed

    Li, W; Swain, M V; Li, Q; Ironside, J; Steven, G P

    2004-09-01

    This experimental investigation aims at revealing the mechanical behaviour and failure pattern of direct fibre-reinforced resin-bonded dental bridge with various designs. To evaluate the overall effects of some newly developed dental materials, in the experiment, genuine composite dental bridge specimens are prepared and tested. The ultimate load, stiffness and mode at the failure of the bridges are measured and compared with the design variations. A good agreement between test and some clinical observations is demonstrated. It is verified that the weakest region appears across the pontic-abutment interface in the composite bridges. This study suggests that the composite bridges reinforced by fibres and supported by adjacent teeth could be of a higher structural strength and stiffness; therefore would provide better clinical performances.

  8. 4. VIEW OF SILVER BRIDGE (ST. MARY'S BRIDGE), CARRYING COUNTY ...

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

    4. VIEW OF SILVER BRIDGE (ST. MARY'S BRIDGE), CARRYING COUNTY ROAD OVER SOURIS RIVER NEAR SOUTH END OF REFUGE, LOOKING NORTHEAST - Upper Souris National Wildlife Refuge Dams, Souris River Basin, Foxholm, Surrey (England), ND

  9. Axionometric Cutaway of Bridge Structure Shoreham Railroad Bridge, Former ...

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

    Axionometric Cutaway of Bridge Structure - Shoreham Railroad Bridge, Former Addison County Railroad (later, Rutland Railroad, Addison Branch), spanning Lemon Fair River above Richville Pond, west of East Shoreham Road, Shoreham, Addison County, VT

  10. Dog Bridge, view of the deck of the bridge and ...

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

    Dog Bridge, view of the deck of the bridge and rails looking from Linden Lane - National Park Seminary, Bounded by Capitol Beltway (I-495), Linden Lane, Woodstove Avenue, & Smith Drive, Silver Spring, Montgomery County, MD

  11. A Bridge to Active Learning: A Summer Bridge Program Helps Students Maximize Their Active-Learning Experiences and the Active-Learning Experiences of Others

    PubMed Central

    Cooper, Katelyn M.; Ashley, Michael; Brownell, Sara E.

    2017-01-01

    National calls to improve student academic success in college have sparked the development of bridge programs designed to help students transition from high school to college. We designed a 2-week Summer Bridge program that taught introductory biology content in an active-learning way. Through a set of exploratory interviews, we unexpectedly identified that Bridge students had developed sophisticated views of active learning, even though this was not an explicit goal of the program. We conducted an additional set of semistructured interviews that focused on active learning and compared the interviews of Bridge students with those from non-Bridge students who had been eligible for but did not participate in the program. We used the constant comparative method to identify themes from the interviews. We found that Bridge students perceived that, because they knew how to approach active learning and viewed it as important, they benefited more from active learning in introductory biology than non-Bridge students. Specifically, Bridge students seemed to be more aware of their own learning gains from participating in active learning. Compared with the majority of non-Bridge students, the majority of Bridge students described using a greater variety of strategies to maximize their experiences in active learning. Finally, in contrast to non-Bridge students, Bridge students indicated that they take an equitable approach to group work. These findings suggest that we may be able to prime students to maximize their own and other’s experiences in active learning. PMID:28232588

  12. A Bridge to Active Learning: A Summer Bridge Program Helps Students Maximize Their Active-Learning Experiences and the Active-Learning Experiences of Others.

    PubMed

    Cooper, Katelyn M; Ashley, Michael; Brownell, Sara E

    2017-01-01

    National calls to improve student academic success in college have sparked the development of bridge programs designed to help students transition from high school to college. We designed a 2-week Summer Bridge program that taught introductory biology content in an active-learning way. Through a set of exploratory interviews, we unexpectedly identified that Bridge students had developed sophisticated views of active learning, even though this was not an explicit goal of the program. We conducted an additional set of semistructured interviews that focused on active learning and compared the interviews of Bridge students with those from non-Bridge students who had been eligible for but did not participate in the program. We used the constant comparative method to identify themes from the interviews. We found that Bridge students perceived that, because they knew how to approach active learning and viewed it as important, they benefited more from active learning in introductory biology than non-Bridge students. Specifically, Bridge students seemed to be more aware of their own learning gains from participating in active learning. Compared with the majority of non-Bridge students, the majority of Bridge students described using a greater variety of strategies to maximize their experiences in active learning. Finally, in contrast to non-Bridge students, Bridge students indicated that they take an equitable approach to group work. These findings suggest that we may be able to prime students to maximize their own and other's experiences in active learning.

  13. 21. RAILROAD, RR. BRIDGE MISSISSIPPI, CLAY CO., WAVERLY 1.5 mi. ...

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

    21. RAILROAD, RR. BRIDGE MISSISSIPPI, CLAY CO., WAVERLY 1.5 mi. S of Ms. 50 Proposed 218-foot turn span, design #2339 of Virginia Bridge and Iron Co., Roanoke, Va. 13 May 1914. Act. size: 16x11 in. Credit: Columbus & Greenville RR, Columbus, Ms. Sarcone Photography, Columbus, Ms. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  14. 25. Photocopy of 1959 drawing for 'WalpoleWestminster Bridge Over: Connecticut ...

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

    25. Photocopy of 1959 drawing for 'Walpole-Westminster Bridge Over: Connecticut River', unattributed. (Filed with N.H. Department of Transportation, Bridge Design Division plan archives, Concord, N.H.) Sheet: Westminster Abutment January 22, 1959 - Walpole-Westminster Bridge, Spanning Connecticut River between Walpole, NH & Westminster, VT, Walpole, Cheshire County, NH

  15. 26. Photocopy of 1968 repair drawing for 'WalpoleWestminster Bridge Over: ...

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

    26. Photocopy of 1968 repair drawing for 'Walpole-Westminster Bridge Over: Connecticut River', unattributed. (Filed with N.H. Department of Transportation, Bridge Design Division plan archives, Concord, N.H.) Sheet: Deck and Expansion Joint Details June 13, 1968 - Walpole-Westminster Bridge, Spanning Connecticut River between Walpole, NH & Westminster, VT, Walpole, Cheshire County, NH

  16. Improved ground-penetrating radar, bridge decks

    SciTech Connect

    Warhus, J.P.; Mast, J.E.; Johansson, E.M.; Nelson, S.D.

    1993-11-29

    Inspection of high-value structures, like bridges and buildings, using Ground Penetrating Radar (GPR) is an application of a technology that is growing in importance. In a typical inspection application, inspectors use GPR to locate structural components, like embedded reinforcing bars, to avoid weakening the structure while collecting core samples for detailed inspection. Advanced GPR, integrated with imaging technologies for use as an NDE tool, can provide the capability to quickly locate and characterize construction flaws and wear- or age-induced damage in these structures without resorting to destructive methods. In this paper, we discuss an important inspection application, namely, concrete bridge deck inspection. We describe an advanced bridge deck inspection system concept (Ground Penetrating Imaging Radar, GPIR) and present results from experiments designed to simulate the concept.

  17. Dynamics and statics of nonaxisymmetric liquid bridges

    NASA Technical Reports Server (NTRS)

    Alexander, J. Iwan D.; Resnick, Andy; Zhang, Yiqiang; Fedoseyev, A.

    1994-01-01

    We finished the construction of the experimental apparatus and the design and testing of some of the visualization and data acquisition techniques. Experimental work focused on three areas: force measurements, loss of stability to nonaxisymmetric bridges, and vibration behavior. The experimental work is summarized in section 2. Selected results from our force measurement experiments are outlined in section 3. In addition we worked on the theory of the dynamic stability of axisymmetric bridges and undertook numerical simulation of the effects of inclined gravity vectors on the minimum volume stability limit for static bridges. The results and status of our theoretical work and numerical simulation are described in section 4. Papers published and in preparation, conference presentations, etc., are described in section 5. Work planned for the third year is discussed in section 6. References cited in the report are listed in section 7.

  18. Monorail bridge conveyor. Phase II report

    SciTech Connect

    Gonski, J

    1982-04-30

    This report covers the second phase of a four-phase contract to develop and test a roof hung monorail bridge conveyor coal haulage system working behind a continuous miner. Phase II covers the fabrication and assembly of all the components in making up the Monoral Bridge Conveyor System. The original concept presented had to be analyzed before final design could proceed. The analysis revealed that 24 ft. long bridge conveyor segments were the optimum length; the suspension system must have the vertical hinge point between bridges, the impact point of the coal transfer point and the suspension point itself, coincidental. The propulsion system is such that each bridge is self propelled in order to minimize side loading on the monorail. The conveyor belt drive is simple since it only has to drive one single 24 ft. conveyor. The entire assembly of twelve conveyors has been pre-tested in our Murfreesboro, Tennessee, shop. The electric circuit proved successful to operate from a manual control or automatically, and successfully proved the cycle of sequential strating and stopping.

  19. 16. LOG AND PLANK BRIDGE ON ACCESS ROAD NEAR BRIDGE ...

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

    16. LOG AND PLANK BRIDGE ON ACCESS ROAD NEAR BRIDGE SITE; SAME STRUCTURE AS SHOWN IN PHOTO #12. ZION NP NEGATIVE NO. 967 ZIO. - Zion-Mount Carmel Highway, Virgin River Bridge, Spanning North Fork of Virgin River on Zion-Mount Carmel Highway, Springdale, Washington County, UT

  20. 50. INTERIOR OF BRIDGE SUSPENSION STRUCTURE ABOVE BRIDGE NOS. 10 ...

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

    50. INTERIOR OF BRIDGE SUSPENSION STRUCTURE ABOVE BRIDGE NOS. 10 AND 9 SHOWING CABLE COUNTERWEIGHT SYSTEM AND SCREW-TYPE VERTICAL ADJUSTMENT MACHINERY (LIFTING SCREWS). LOOKING NORTH. - Greenville Yard, Transfer Bridge System, Port of New York/New Jersey, Upper New York Bay, Jersey City, Hudson County, NJ

  1. BUILDING "BRIDGES" WITH QUALITY ASSURANCE

    EPA Science Inventory

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

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

    ERIC Educational Resources Information Center

    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)

  3. Building Migratory Bridges

    ERIC Educational Resources Information Center

    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…

  4. Bridging a Cultural Gap

    ERIC Educational Resources Information Center

    Leviatan, Talma

    2008-01-01

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

  5. Bridging the Abyss

    ERIC Educational Resources Information Center

    Olcott, Marianina

    2007-01-01

    This paper seeks to explain the epistemological bases for the two cultures and to show why this disciplinary divide continues to plague American academic culture. Next, we discuss strategies for bridging the two cultures through general education curricula which promote mutual understanding of the two cultures while educating students in basic…

  6. Bridging Disciplinary Boundaries

    ERIC Educational Resources Information Center

    Mei, Linda

    2009-01-01

    Interdisciplinary education promotes the unity of knowledge by bridging the cultural divide between the social constructs of disciplines and encourages the development of knowledge to enhance society. As an inquiry-based and relevant approach that expands and advances knowledge, interdisciplinary education facilitates creativity and flexibility,…

  7. The Bridge to Somewhere

    ERIC Educational Resources Information Center

    Lum, Lydia

    2009-01-01

    Since its inception in 2000, Pan-Asian American Community House's (PAACH's) education mission has bridged Asian-American studies to student life. PAACH initiatives have helped spread Asian-American diaspora to thousands of students at the University of Pennsylvania. They have also helped students determine for themselves what it means to be a…

  8. Tech Prep Bridge Programs.

    ERIC Educational Resources Information Center

    Gohdes, William

    1995-01-01

    Although tech prep is still in its infancy in Georgia, increasing numbers of students are entering technical institutes after having completed the secondary-level component of tech prep programs. Georgia's technical institutes must begin the process of developing bridge programs to help adult students with no tech prep experience develop academic…

  9. Bridging and Reading Proficiency.

    ERIC Educational Resources Information Center

    Philbin, Margaret M.; Rubenstein, Herbert

    A study was conducted for additional support of the view that bridging--drawing inferences to relate a sentence to a preceding sentence--occurs during reading rather than at the time of testing. Subjects were 88 third and 67 fifth grade students whose reading proficiency was measured by performance on the Metropolitan Achievement Test. The…

  10. Building Bridges to China.

    ERIC Educational Resources Information Center

    Wasta, Stephanie; Scott, Margaret

    1998-01-01

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

  11. Reconfigurable wireless monitoring systems for bridges: validation on the Yeondae Bridge

    NASA Astrophysics Data System (ADS)

    Kim, Junhee; Lynch, Jerome P.; Zonta, Daniele; Lee, Jong-Jae; Yun, Chung-Bang

    2009-03-01

    The installation of a structural monitoring system on a medium- to large-span bridge can be a challenging undertaking due to high system costs and time consuming installations. However, these historical challenges can be eliminated by using wireless sensors as the primary building block of a structural monitoring system. Wireless sensors are low-cost data acquisition nodes that utilize wireless communication to transfer data from the sensor to the data repository. Another advantageous characteristic of wireless sensors is their ability to be easily removed and reinstalled in another sensor location on the same structure; this installation modularity is highlighted in this study. Wireless sensor nodes designed for structural monitoring applications are installed on the 180 m long Yeondae Bridge (Korea) to measure the dynamic response of the bridge to controlled truck loading. To attain a high nodal density with a small number (20) of wireless sensors, the wireless sensor network is installed three times with each installation concentrating sensors in one portion of the bridge. Using forced and free vibration response data from the three installations, the modal properties of the bridge are accurately identified. Intentional nodal overlapping of the three different sensor installations allows mode shapes from each installation to be stitched together into global mode shapes. Specifically, modal properties of the Yeondae Bridge are derived off-line using frequency domain decomposition (FDD) modal analysis methods.

  12. Cangrelor in patients undergoing cardiac surgery: the BRIDGE study.

    PubMed

    Voeltz, Michele D; Manoukian, Steven V

    2013-07-01

    The benefit of long-term dual antiplatelet therapy (DAPT) in patients with acute coronary syndromes, drug-eluting stents and those at high risk for thromboembolic events has been well established in a number of well-designed randomized controlled studies. Current research in this area has focused on the development of novel antiplatelet agents for clinical use. The BRIDGE trial evaluated the use of cangrelor as a bridge to coronary artery bypass graft surgery in patients receiving extended DAPT. The BRIDGE trial results confirm the efficacy and safety of cangrelor in this population. This study is novel as it attempts to address the lapse in thienopyridine therapy required for many surgical and invasive procedures. The future of antiplatelet agents, particularly cangrelor, must also focus on bridging for high-risk patients undergoing noncoronary artery bypass graft surgical procedures. Overall, the BRIDGE trial represents a significant advance for patients appropriate for long-term DAPT.

  13. Cracking behavior of structural slab bridge decks

    NASA Astrophysics Data System (ADS)

    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.

  14. Bridge of bone canthopexy.

    PubMed

    Yaremchuk, Michael J; Chen, Yi-Chieh

    2009-01-01

    Bridge of bone canthopexy has utility when significant movements of canthal position are required. It is a technique whereby the lateral canthal structures are purchased with a figure-of-eight suture of titanium wire. Drill holes are placed in the lateral orbital rim using the zygomaticofrontal sutures as reference landmarks. A canthal fixation point (the inferior drill hole) creates a measured distance from a fixed anatomic point (the zygomaticofrontal suture) assuring accurate and symmetric canthus positioning. Wire suture fixation over the bridge of bone created by the two drill holes provides maximum stability to counter soft tissue deforming forces. Fine adjustments can be made to the canthal position by twisting or untwisting the wire ends.

  15. Electrical Actuation Technology Bridging

    NASA Technical Reports Server (NTRS)

    Hammond, Monica (Compiler); Sharkey, John (Compiler)

    1993-01-01

    This document contains the proceedings of the NASA Electrical Actuation Technology Bridging (ELA-TB) Workshop held in Huntsville, Alabama, September 29-October 1, 1992. The workshop was sponsored by the NASA Office of Space Systems Development and Marshall Space Flight Center (MSFC). The workshop addressed key technologies bridging the entire field of electrical actuation including systems methodology, control electronics, power source systems, reliability, maintainability, and vehicle health management with special emphasis on thrust vector control (TVC) applications on NASA launch vehicles. Speakers were drawn primarily from industry with participation from universities and government. In addition, prototype hardware demonstrations were held at the MSFC Propulsion Laboratory each afternoon. Splinter sessions held on the final day afforded the opportunity to discuss key issues and to provide overall recommendations. Presentations are included in this document.

  16. Climbing techniques for bridge inspection

    NASA Astrophysics Data System (ADS)

    Kaslan, Erol C.

    1998-03-01

    California has about 24,000 publicly owned bridges that require routine structural evaluations to comply with National Bridge Inspection Standard (NBIS) mandates. Of these, about 800 are identified as possessing fatigue prone or fracture critical details requiring thorough tactile investigations. Gaining access to bridge elements to perform these investigations has become increasingly difficult and costly. The traditional uses of under bridge inspection trucks, lift equipment and rigging are economically and practically limited by bridge size, structure type, traffic demands and support costs. In some cases, bridges that have become damaged by earthquakes cannot safely support the loads of heavy personnel lift equipment. The California Department of Transportation (Caltrans)'s Office of Structural Materials and Office of Structure Maintenance and Investigations evaluated the use of rock climbing and mountaineering techniques as an alternative means of gaining access for bridge inspections. Under a small research grant, a bridge climbing training course was developed through a local University of California outdoor recreation group and 7 engineers and technicians were initially trained. A comprehensive Code of Safe Practices was created and standards of training, procedures and equipment required for bridge inspections were established. A successful climb investigation on a large, previously inaccessible arch bridge was completed at the end of the training that proved the techniques safe, economical and effective. Within one year, 20 bridge maintenance engineers were trained, and a formal program was established to organize, schedule, equip and certify engineers and technicians for bridge climbing. Several other offices within Caltrans as well as the California Department of Water Resources have since adopted these techniques for specialized structural inspection tasks. Climbing techniques are now used routinely in California as an alterative means of gaining access

  17. Nematic liquid crystal bridges

    NASA Astrophysics Data System (ADS)

    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.

  18. Bridge monitoring using heterogeneous wireless sensor network

    NASA Astrophysics Data System (ADS)

    Haran, Shivan; Kher, Shubhalaxmi; Mehndiratta, Vandana

    2010-03-01

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

  19. Bridging the gaps in systems biology.

    PubMed

    Cvijovic, Marija; Almquist, Joachim; Hagmar, Jonas; Hohmann, Stefan; Kaltenbach, Hans-Michael; Klipp, Edda; Krantz, Marcus; Mendes, Pedro; Nelander, Sven; Nielsen, Jens; Pagnani, Andrea; Przulj, Natasa; Raue, Andreas; Stelling, Jörg; Stoma, Szymon; Tobin, Frank; Wodke, Judith A H; Zecchina, Riccardo; Jirstrand, Mats

    2014-10-01

    Systems biology aims at creating mathematical models, i.e., computational reconstructions of biological systems and processes that will result in a new level of understanding-the elucidation of the basic and presumably conserved "design" and "engineering" principles of biomolecular systems. Thus, systems biology will move biology from a phenomenological to a predictive science. Mathematical modeling of biological networks and processes has already greatly improved our understanding of many cellular processes. However, given the massive amount of qualitative and quantitative data currently produced and number of burning questions in health care and biotechnology needed to be solved is still in its early phases. The field requires novel approaches for abstraction, for modeling bioprocesses that follow different biochemical and biophysical rules, and for combining different modules into larger models that still allow realistic simulation with the computational power available today. We have identified and discussed currently most prominent problems in systems biology: (1) how to bridge different scales of modeling abstraction, (2) how to bridge the gap between topological and mechanistic modeling, and (3) how to bridge the wet and dry laboratory gap. The future success of systems biology largely depends on bridging the recognized gaps.

  20. Final Environmental Assessment, Horse Creek Bridge Replacement

    DTIC Science & Technology

    2010-10-01

    floodplain, deep swamp, meander scars, loops, and oxbow lakes . Sandy Run Creek, along the southern boundary of Robins AFB, has a floodplain up to 2,000...River floodplain (Figure 3). The erosion action of the Ocmulgee has created bluffs, high floodplain, deep swamp, meander scars, loops, and oxbow ... lakes . Robins Air Force Base Horse Creek Bridge Replacement J. Gross L. Neal 15268146 April 2010 CLIENT: TITLE: PROJECT: DATE: SCALE: FILE: DESIGNED

  1. Dynamic Characterization of an All-FRP Bridge

    NASA Astrophysics Data System (ADS)

    Casalegno, C.; Russo, S.

    2017-03-01

    The light weight and high deformability of bridges made with pultruded FRP (fiber-reinforced polymer) materials make them very promising, but, at the same time, vulnerable to dynamic loadings. As a consequence, the vibration serviceability limit state can govern their design. There is currently a lack of data about the dynamic characteristics of FRP bridges and of design guidelines for securing their vibration serviceability. The paper presents the results of dynamic testing and characterization of an all-FRP spatial footbridge. The main modal parameters of the bridge are evaluated by an experimental modal analysis and by comparison of experimental data with FE analysis results. The identified flexural and torsional modes of the bridge are characterized by relatively high values of frequencies and damping. Results of the dynamic characterization give useful information about the dynamic characteristics of this kind of structures and can contribute to the elaboration of future guidelines for providing them with the vibration serviceability.

  2. Seismic studies of the San Francisco-Oakland Bay Bridge

    SciTech Connect

    Astaneh-Asl, A; Larsen, S; McCallen, D

    1999-08-17

    Computational simulation plays a central role in the engineering analysis and design of major bridge structures and accurate simulations are essential for the development of earthquake resistant and economical structural designs. This paper describes new methodologies and computational tools which have recently been developed for simulating earthquake ground motions and the seismic response of cable supported bridges. The simulation tools are described and an example application for an important long-span suspension bridge is demonstrated. The application portion of the study has particular focus on the potential damaging effects of long period displacement pulses and permanent ground displacements which can occur when a bridge is located in the near-field of a major earthquake fault.

  3. Piezoelectric energy harvesting from traffic-induced bridge vibrations

    NASA Astrophysics Data System (ADS)

    Peigney, Michaël; Siegert, Dominique

    2013-09-01

    This paper focuses on energy harvesting from traffic-induced vibrations in bridges. Using a pre-stressed concrete highway bridge as a case study, in situ vibration measurements are presented and analysed. From these results, a prototype of a cantilever piezoelectric harvester is designed, tested and modelled. Even though the considered bridge vibrations are characterized by small amplitude and a low frequency (i.e. below 15 Hz), it is shown that mean power of the order of 0.03 mW can be produced, with a controlled voltage between 1.8 and 3.6 V. A simple model is proposed for theoretical prediction of the delivered power in terms of traffic intensity. This model shows good agreement with the experimental results and leads to a simple but effective design rule for piezoelectric harvesters to be used on bridges.

  4. On the road to metallic nanoparticles by rational design: bridging the gap between atomic-level theoretical modeling and reality by total scattering experiments

    NASA Astrophysics Data System (ADS)

    Prasai, Binay; Wilson, A. R.; Wiley, B. J.; Ren, Y.; Petkov, Valeri

    2015-10-01

    The extent to which current theoretical modeling alone can reveal real-world metallic nanoparticles (NPs) at the atomic level was scrutinized and demonstrated to be insufficient and how it can be improved by using a pragmatic approach involving straightforward experiments is shown. In particular, 4 to 6 nm in size silica supported Au100-xPdx (x = 30, 46 and 58) explored for catalytic applications is characterized structurally by total scattering experiments including high-energy synchrotron X-ray diffraction (XRD) coupled to atomic pair distribution function (PDF) analysis. Atomic-level models for the NPs are built by molecular dynamics simulations based on the archetypal for current theoretical modeling Sutton-Chen (SC) method. Models are matched against independent experimental data and are demonstrated to be inaccurate unless their theoretical foundation, i.e. the SC method, is supplemented with basic yet crucial information on the length and strength of metal-to-metal bonds and, when necessary, structural disorder in the actual NPs studied. An atomic PDF-based approach for accessing such information and implementing it in theoretical modeling is put forward. For completeness, the approach is concisely demonstrated on 15 nm in size water-dispersed Au particles explored for bio-medical applications and 16 nm in size hexane-dispersed Fe48Pd52 particles explored for magnetic applications as well. It is argued that when ``tuned up'' against experiments relevant to metals and alloys confined to nanoscale dimensions, such as total scattering coupled to atomic PDF analysis, rather than by mere intuition and/or against data for the respective solids, atomic-level theoretical modeling can provide a sound understanding of the synthesis-structure-property relationships in real-world metallic NPs. Ultimately this can help advance nanoscience and technology a step closer to producing metallic NPs by rational design.The extent to which current theoretical modeling alone can

  5. On the road to metallic nanoparticles by rational design: bridging the gap between atomic-level theoretical modeling and reality by total scattering experiments.

    PubMed

    Prasai, Binay; Wilson, A R; Wiley, B J; Ren, Y; Petkov, Valeri

    2015-11-14

    The extent to which current theoretical modeling alone can reveal real-world metallic nanoparticles (NPs) at the atomic level was scrutinized and demonstrated to be insufficient and how it can be improved by using a pragmatic approach involving straightforward experiments is shown. In particular, 4 to 6 nm in size silica supported Au(100-x)Pd(x) (x = 30, 46 and 58) explored for catalytic applications is characterized structurally by total scattering experiments including high-energy synchrotron X-ray diffraction (XRD) coupled to atomic pair distribution function (PDF) analysis. Atomic-level models for the NPs are built by molecular dynamics simulations based on the archetypal for current theoretical modeling Sutton-Chen (SC) method. Models are matched against independent experimental data and are demonstrated to be inaccurate unless their theoretical foundation, i.e. the SC method, is supplemented with basic yet crucial information on the length and strength of metal-to-metal bonds and, when necessary, structural disorder in the actual NPs studied. An atomic PDF-based approach for accessing such information and implementing it in theoretical modeling is put forward. For completeness, the approach is concisely demonstrated on 15 nm in size water-dispersed Au particles explored for bio-medical applications and 16 nm in size hexane-dispersed Fe48Pd52 particles explored for magnetic applications as well. It is argued that when "tuned up" against experiments relevant to metals and alloys confined to nanoscale dimensions, such as total scattering coupled to atomic PDF analysis, rather than by mere intuition and/or against data for the respective solids, atomic-level theoretical modeling can provide a sound understanding of the synthesis-structure-property relationships in real-world metallic NPs. Ultimately this can help advance nanoscience and technology a step closer to producing metallic NPs by rational design.

  6. Morphological aspects of myocardial bridges.

    PubMed

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

    2013-11-01

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

  7. Wind Tunnel Measurements for Flutter of a Long-Afterbody Bridge Deck.

    PubMed

    Chen, Zeng-Shun; Zhang, Cheng; Wang, Xu; Ma, Cun-Ming

    2017-02-09

    Bridges are an important component of transportation. Flutter is a self-excited, large amplitude vibration, which may lead to collapse of bridges. It must be understood and avoided. This paper takes the Jianghai Channel Bridge, which is a significant part of the Hong Kong-Zhuhai-Macao Bridge, as an example to investigate the flutter of the bridge deck. Firstly, aerodynamic force models for flutter of bridges were introduced. Then, wind tunnel tests of the bridge deck during the construction and the operation stages, under different wind attack angles and wind velocities, were carried out using a high frequency base balance (HFBB) system and laser displacement sensors. From the tests, the static aerodynamic forces and flutter derivatives of the bridge deck were observed. Correspondingly, the critical flutter wind speeds of the bridge deck were determined based on the derivatives, and they are compared with the directly measured flutter speeds. Results show that the observed derivatives are reasonable and applicable. Furthermore, the critical wind speeds in the operation stage is smaller than those in the construction stage. Besides, the flutter instabilities of the bridge in the construction and the operation stages are good. This study helps guarantee the design and the construction of the Jianghai Channel Bridge, and advances the understanding of flutter of long afterbody bridge decks.

  8. Wind Tunnel Measurements for Flutter of a Long-Afterbody Bridge Deck

    PubMed Central

    Chen, Zeng-Shun; Zhang, Cheng; Wang, Xu; Ma, Cun-Ming

    2017-01-01

    Bridges are an important component of transportation. Flutter is a self-excited, large amplitude vibration, which may lead to collapse of bridges. It must be understood and avoided. This paper takes the Jianghai Channel Bridge, which is a significant part of the Hong Kong-Zhuhai-Macao Bridge, as an example to investigate the flutter of the bridge deck. Firstly, aerodynamic force models for flutter of bridges were introduced. Then, wind tunnel tests of the bridge deck during the construction and the operation stages, under different wind attack angles and wind velocities, were carried out using a high frequency base balance (HFBB) system and laser displacement sensors. From the tests, the static aerodynamic forces and flutter derivatives of the bridge deck were observed. Correspondingly, the critical flutter wind speeds of the bridge deck were determined based on the derivatives, and they are compared with the directly measured flutter speeds. Results show that the observed derivatives are reasonable and applicable. Furthermore, the critical wind speeds in the operation stage is smaller than those in the construction stage. Besides, the flutter instabilities of the bridge in the construction and the operation stages are good. This study helps guarantee the design and the construction of the Jianghai Channel Bridge, and advances the understanding of flutter of long afterbody bridge decks. PMID:28208773

  9. Translating Climate Projections for Bridge Engineering

    NASA Astrophysics Data System (ADS)

    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

  10. 25. White Plains Road Bridge in foreground; Unionport Road Bridge ...

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

    25. White Plains Road Bridge in foreground; Unionport Road Bridge in background. Van Nest, Bronx Co., NY. Sec. 4207, MP 12.75./78. - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York County, NY

  11. Estimation of Potential Bridge Scour at Bridges on State Routes in South Dakota, 2003-07

    USGS Publications Warehouse

    Thompson, Ryan F.; Fosness, Ryan L.

    2008-01-01

    Flowing water can erode (scour) soils and cause structural failure of a bridge by exposing or undermining bridge foundations (abutments and piers). A rapid scour-estimation technique, known as the level-1.5 method and developed by the U.S. Geological Survey, was used to evaluate potential scour at bridges in South Dakota in a study conducted in cooperation with the South Dakota Department of Transportation. This method was used during 2003-07 to estimate scour for the 100-year and 500-year floods at 734 selected bridges managed by the South Dakota Department of Transportation on State routes in South Dakota. Scour depths and other parameters estimated from the level-1.5 analyses are presented in tabular form. Estimates of potential contraction scour at the 734 bridges ranged from 0 to 33.9 feet for the 100-year flood and from 0 to 35.8 feet for the 500-year flood. Abutment scour ranged from 0 to 36.9 feet for the 100-year flood and from 0 to 45.9 feet for the 500-year flood. Pier scour ranged from 0 to 30.8 feet for the 100-year flood and from 0 to 30.7 feet for the 500-year flood. The scour depths estimated by using the level-1.5 method can be used by the South Dakota Department of Transportation and others to identify bridges that may be susceptible to scour. Scour at 19 selected bridges also was estimated by using the level-2 method. Estimates of contraction, abutment, and pier scour calculated by using the level-1.5 and level-2 methods are presented in tabular and graphical formats. Compared to level-2 scour estimates, the level-1.5 method generally overestimated scour as designed, or in a few cases slightly underestimated scour. Results of the level-2 analyses were used to develop regression equations for change in head and average velocity through the bridge opening. These regression equations derived from South Dakota data are compared to similar regression equations derived from Montana and Colorado data. Future level-1.5 scour investigations in South

  12. An overheight vehicle bridge collision monitoring system using piezoelectric transducers

    NASA Astrophysics Data System (ADS)

    Song, G.; Olmi, C.; Gu, H.

    2007-04-01

    With increasing traffic volume follows an increase in the number of overheight truck collisions with highway bridges. The detection of collision impact and evaluation of the impact level is a critical issue in the maintenance of a concrete bridge. In this paper, an overheight collision detection and evaluation system is developed for concrete bridge girders using piezoelectric transducers. An electric circuit is designed to detect the impact and to activate a digital camera to take photos of the offending truck. Impact tests and a health monitoring test were conducted on a model concrete bridge girder by using three piezoelectric transducers embedded before casting. From the experimental data of the impact test, it can be seen that there is a linear relation between the output of sensor energy and the impact energy. The health monitoring results show that the proposed damage index indicates the level of damage inside the model concrete bridge girder. The proposed overheight truck-bridge collision detection and evaluation system has the potential to be applied to the safety monitoring of highway bridges.

  13. Expected damages of retrofitted bridges with RC jacketing

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

  14. 47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Bridge-to-bridge radiotelephone installation. 80.1007 Section 80.1007 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... Bridge-to-Bridge Act § 80.1007 Bridge-to-bridge radiotelephone installation. Use of the...

  15. 47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Bridge-to-bridge radiotelephone installation. 80.1007 Section 80.1007 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... Bridge-to-Bridge Act § 80.1007 Bridge-to-bridge radiotelephone installation. Use of the...

  16. 47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Bridge-to-bridge radiotelephone installation. 80.1007 Section 80.1007 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... Bridge-to-Bridge Act § 80.1007 Bridge-to-bridge radiotelephone installation. Use of the...

  17. 47 CFR 80.163 - Operator requirements of the Bridge-to-Bridge Act.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Operator requirements of the Bridge-to-Bridge... Requirements § 80.163 Operator requirements of the Bridge-to-Bridge Act. Each ship subject to the Bridge-to-Bridge Act must have on board a radio operator who holds a restricted radiotelephone operator permit...

  18. 47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Bridge-to-bridge radiotelephone installation. 80.1007 Section 80.1007 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... Bridge-to-Bridge Act § 80.1007 Bridge-to-bridge radiotelephone installation. Use of the...

  19. 47 CFR 80.163 - Operator requirements of the Bridge-to-Bridge Act.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Operator requirements of the Bridge-to-Bridge... Requirements § 80.163 Operator requirements of the Bridge-to-Bridge Act. Each ship subject to the Bridge-to-Bridge Act must have on board a radio operator who holds a restricted radiotelephone operator permit...

  20. 47 CFR 80.163 - Operator requirements of the Bridge-to-Bridge Act.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Operator requirements of the Bridge-to-Bridge... Requirements § 80.163 Operator requirements of the Bridge-to-Bridge Act. Each ship subject to the Bridge-to-Bridge Act must have on board a radio operator who holds a restricted radiotelephone operator permit...

  1. 47 CFR 80.163 - Operator requirements of the Bridge-to-Bridge Act.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Operator requirements of the Bridge-to-Bridge... Requirements § 80.163 Operator requirements of the Bridge-to-Bridge Act. Each ship subject to the Bridge-to-Bridge Act must have on board a radio operator who holds a restricted radiotelephone operator permit...

  2. 47 CFR 80.163 - Operator requirements of the Bridge-to-Bridge Act.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Operator requirements of the Bridge-to-Bridge... Requirements § 80.163 Operator requirements of the Bridge-to-Bridge Act. Each ship subject to the Bridge-to-Bridge Act must have on board a radio operator who holds a restricted radiotelephone operator permit...

  3. 47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Bridge-to-bridge radiotelephone installation. 80.1007 Section 80.1007 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... Bridge-to-Bridge Act § 80.1007 Bridge-to-bridge radiotelephone installation. Use of the...

  4. Identification of damping in a bridge using a moving instrumented vehicle

    NASA Astrophysics Data System (ADS)

    González, A.; OBrien, E. J.; McGetrick, P. J.

    2012-08-01

    In recent years, there has been a significant increase in the number of bridges which are being instrumented and monitored on an ongoing basis. This is in part due to the introduction of bridge management systems designed to provide a high level of protection to the public and early warning if the bridge becomes unsafe. This paper investigates a novel alternative; a low-cost method consisting of the use of a vehicle fitted with accelerometers on its axles to monitor the dynamic behaviour of bridges. A simplified half-car vehicle-bridge interaction model is used in theoretical simulations to test the effectiveness of the approach in identifying the damping ratio of the bridge. The method is tested for a range of bridge spans and vehicle velocities using theoretical simulations and the influences of road roughness, initial vibratory condition of the vehicle, signal noise, modelling errors and frequency matching on the accuracy of the results are investigated.

  5. The violin bridge as filter.

    PubMed

    Bissinger, George

    2006-07-01

    The violin bridge filter role was investigated using modal and acoustic measurements on 12 quality-rated violins combined with systematic bridge rocking frequency f(rock) and wing mass decrements deltam on four bridges for two other violins. No isolated bridge resonances were observed; bridge motions were complex (including a "squat" mode near 0.8 kHz) except for low frequency rigid body pivot motions, all more or less resembling rocking motion at higher frequencies. A conspicuous broad peak near 2.3 kHz in bridge driving point mobility (labeled BH) was seen for good and bad violins. Similar structure was seen in averaged bridge, bridge feet, corpus mobilities and averaged radiativity. No correlation between violin quality and BH driving point, averaged corpus mobility magnitude, or radiativity was found. Increasing averaged-over-f(rock) deltam(g) from 0 to 0.12 generally increased radiativity across the spectrum. Decreasing averaged-over-deltam f(rock) from 3.6 to 2.6 kHz produced consistent decreases in radiativity between 3 and 4.2 kHz, but only few-percent decreases in BH frequency. The lowest f(rock) values were accompanied by significantly reduced radiation from the Helmholtz A0 mode near 280 Hz; this, combined with reduced high frequency output, created overall radiativity profiles quite similar to "bad" violins among the quality-rated violins.

  6. Saving the Kilgore Covered Bridge.

    ERIC Educational Resources Information Center

    Clark, Wilma

    1988-01-01

    Describes an American literature class project to save a covered bridge from collapse. Illustrates how student initiative in contacting government agencies and news media, learning the history of the bridge, and raising public awareness about the project led to a joint county agreement to preserve the historic span. (DHP)

  7. Cost of Impressed Current Cathodic Protection for Coastal Oregon Bridges

    SciTech Connect

    Holcomb, Gordon R.; Cryer, Curtis B.

    1998-07-01

    The State of Oregon is using arc-sprayed zinc coatings for anodes in impressed current cathodic protection (ICCP) systems on reinforced concrete coastal bridges. The two lowest bids for four ICCP projects were averaged and converted to 1997 dollars. The total average cost for the ICCP projects was $51.63/ft2 ($555.51/m2) of protected concrete. The cathodic protection part of the ICCP projects average $14.08/ft2 ($151.47/m2), while zinc anode installation cost an average of $7.13/ft2 ($76.67/m2). Oregon's rugged and beautiful coastline is graced with a series of historical arched bridges designed by Conde B. McCullough. McCullough is the internationally recognized architect who designed many of the Oregon Coast Highway (U.S. 101) bridges in the 1920s and 1930s. Many are listed on the National Historic Register. After the expense ($45m) and public outcry associated with the replacement of the historic Alsea Bay Bridge in Waldport, Oregon, the Oregon Department of Transportation began using impressed current cathodic protection (ICCP) to extend the service life of reinforced concrete bridges. Figure 1 visually illustrates the need for such remediation. It shows exposed rebar from underneath the Brush Creek Bridge, which is very representative of the conditions found underneath many coastal Oregon bridges. Four ICCP projects have been funded, put out for bid, and completed. The four projects, their bid closing dates, and their completion dates are the Cape Creek Bridge (1990- 1992), the Yaquina Bay Bridge south arches (1991-1995), the Depoe Bay Bridge (1993-1997), and the Yaquina Bay Bridge south approach (1995-1997). The Cape Creek, Yaquina Bay, and Depoe Bay Bridges are shown in Figs. 2-4. Other ICCP projects are underway on the Oregon coast. In the ICCP systems, arc-sprayed zinc coatings on the concrete surface are anodes that protect the steel rebar. Accelerated laboratory studies at the Albany Research Center have predicted zinc anode service lives of

  8. Instrumentation for detailed bridge-scour measurements

    USGS Publications Warehouse

    Landers, Mark N.; Mueller, David S.; Trent, Roy E.; ,

    1993-01-01

    A portable instrumentation system is being developed to obtain channel bathymetry during floods for detailed bridge-scour measurements. Portable scour measuring systems have four components: sounding instrument, horizontal positioning instrument, deployment mechanisms, and data storage device. The sounding instrument will be a digital fathometer. Horizontal position will be measured using a range-azimuth based hydrographic survey system. The deployment mechanism designed for this system is a remote-controlled boat using a small waterplane area, twin-hull design. An on-board computer and radio will monitor the vessel instrumentation, record measured data, and telemeter data to shore.

  9. Epoxy coated reinforcement in bridge decks

    NASA Astrophysics Data System (ADS)

    Wills, J.

    A review was conducted of methods relating to the use of epoxy coated reinforcing bars for bridge decks and their potential for use in the United Kingdom. A survey of work carried out in the USA was carried out and the analysis used in a preliminary cost study. The options of having either a hot rolled asphalt surfacing or a permanently exposed concrete wearing surface were considered. It was concluded that epoxy coating of the top steel in addition to current waterproofing practice would provide, at relatively little extra cost, additional assurance that the reinforcement would be adequately protected throughout the life of a bridge. Current design rules do not permit decks with permanently exposed concrete wearing surface without waterproofing. Epoxy coating may afford a means of introducing such decks but before a positive recommendation to delete waterproofing can be made further studies would have to be undertaken.

  10. Online bridge crack monitoring with smart film.

    PubMed

    Zhang, Benniu; Wang, Shuliang; Li, Xingxing; Zhou, Zhixiang; Zhang, Xu; Yang, Guang; Qiu, Minfeng

    2013-01-01

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

  11. Online Bridge Crack Monitoring with Smart Film

    PubMed Central

    Wang, Shuliang; Li, Xingxing; Zhou, Zhixiang; Zhang, Xu; Yang, Guang; Qiu, Minfeng

    2013-01-01

    Smart film crack monitoring method, which can be used for detecting initiation, length, width, shape, location, and propagation of cracks on real bridges, is proposed. Firstly, the fabrication of the smart film is developed. Then the feasibility of the method is analyzed and verified by the mechanical sensing character of the smart film under the two conditions of normal strain and crack initiation. Meanwhile, the coupling interference between parallel enameled wires of the smart film is discussed, and then low-frequency detecting signal and the custom communication protocol are used to decrease interference. On this basis, crack monitoring system with smart film is designed, where the collected crack data is sent to the remote monitoring center and the cracks are simulated and recurred. Finally, the monitoring system is applied to six bridges, and the effects are discussed. PMID:24489496

  12. Norfolk Lake Highway Bridges, Baxter County, Arkansas, White River and Tributaries, North Fork River, Arkansas Foundation Report.

    DTIC Science & Technology

    1983-06-01

    References. a. Design Memorandum No. 3, Norfork Lake Highway Bridges, dated December 1976. b. Geotechnical Engineering Report, Norfork Lake Highway Bridges...AD-A130 553 NORFOLK LAKE HIGHWAY BRIDGES BAXTER COUNTY ARKANSAS 1/5 WHITE RIVER AND TRIBU.. U) ARMY ENGINEER DISTRICT LITTLE ROCK ARK R L CRUTCHFIELD...UN*4 bU f.-It US Army Corps of Engineers Little Rock District NORFORK LAKE HIGHWAY BRIDGES c BAXTER COUNTY, ARKANSAS co WHITE RIVER AND TRIBUTARIES

  13. Streamflow and streambed scour in 2010 at bridge 339, Copper River, Alaska

    USGS Publications Warehouse

    Conaway, Jeffrey S.; Brabets, Timothy P.

    2011-01-01

    The distribution of the Copper River's discharge through the bridges was relatively stable until sometime between 1969-70 and 1982-85. The majority of the total Copper River discharge in 1969-70 passed through three bridges on the western side of the delta, but by 1982-1985, 25 to 62 percent of the flow passed through bridge 342 on the eastern side of the Copper River Delta. In 2004, only 8 percent of the flow passed through the western bridges, while 90 percent of the discharge flowed through two bridges on the eastern side of the delta. Migration of the river across the delta and redistribution of discharge has resulted in streambed scour at some bridges, overtopping of the road during high flows, prolonged highway closures, and formation of new channels through forests. Scour monitoring at the eastern bridges has recorded as much as 44 feet of fill at one pier and 33 feet of scour at another. In 2009, flow distribution began to shift from the larger bridge 342 to bridge 339. In 2010, flow in excess of four times the design discharge scoured the streambed at bridge 339 to a level such that constant on-site monitoring was required to evaluate the potential need for bridge closure. In 2010, instantaneous flow through bridge 339 was never less than 30 percent and was as high as 49 percent of the total Copper River discharge. The percentage of flow through bridge 339 decreased when the overall Copper River discharge increased. The increased discharge through bridge 339 is attributed to a shift in the approach channel 3,500 feet upstream. Bridge channel alignment and analysis of flow distribution as of October 2010 indicate these hydrologic hazards will persist in 2011.

  14. Galactic bridges and tails.

    NASA Technical Reports Server (NTRS)

    Toomre, A.; Toomre, J.

    1972-01-01

    This paper argues that the bridges and tails seen in some multiple galaxies are just tidal relics of close encounters. These consequences of the brief but violent tidal forces are here studied in a deliberately simple-minded fashion. Each encounter is considered to involve only two galaxies and to be roughly parabolic; each galaxy is idealized as just a disk of noninteracting test particles which initially orbit a central mass point. As shown here, the two-sided distortions provoked by gravity alone in such circumstances can indeed evolve kinematically into some remarkably narrow and elongated features. Besides extensive pictorial survey of tidal damage, this paper offers reconstructions of the orbits and outer shapes of four specific interacting pairs: Arp 295, M51 + NGC 5195, NGC 4676, and NGC 4038/9.

  15. Burning trees and bridges

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.

    1990-01-01

    Most burning of biomass is the result of human activity, and on a global scale it is increasing. Tropospheric concentrations of CO2, CO, CH4, non-methane hydrocarbons, and ozone are all increasing with time; global biomass burning may make an important contribution to this increase and thus to potential global climate change. The nitrogen cycle also can have important climatic effects. Nitrous oxide put into the atmosphere by biomass burning is a greenhouse gas 250 times more powerful (molecule for molecule) than carbon dioxide. Nitric oxide, as well as being a photochemical precursor of ozone, a major pollutant in the troposphere, produces nitric acid, the fastest-growing component of acid rain. Hence, the new bridge in the nitrogen cycle is of more than mere technical interest.

  16. Cascaded resonant bridge converters

    NASA Technical Reports Server (NTRS)

    Stuart, Thomas A. (Inventor)

    1989-01-01

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

  17. Epithelial bridges maintain tissue integrity during collective cell migration

    NASA Astrophysics Data System (ADS)

    Vedula, Sri Ram Krishna; Hirata, Hiroaki; Nai, Mui Hoon; Brugués, Agustí; Toyama, Yusuke; Trepat, Xavier; Lim, Chwee Teck; Ladoux, Benoit

    2014-01-01

    The ability of skin to act as a barrier is primarily determined by the efficiency of skin cells to maintain and restore its continuity and integrity. In fact, during wound healing keratinocytes migrate collectively to maintain their cohesion despite heterogeneities in the extracellular matrix. Here, we show that monolayers of human keratinocytes migrating along functionalized micropatterned surfaces comprising alternating strips of extracellular matrix (fibronectin) and non-adherent polymer form suspended multicellular bridges over the non-adherent areas. The bridges are held together by intercellular adhesion and are subjected to considerable tension, as indicated by the presence of prominent actin bundles. We also show that a model based on force propagation through an elastic material reproduces the main features of bridge maintenance and tension distribution. Our findings suggest that multicellular bridges maintain tissue integrity during wound healing when cell-substrate interactions are weak and may prove helpful in the design of artificial scaffolds for skin regeneration.

  18. Venture Creation Programs: Bridging Entrepreneurship Education and Technology Transfer

    ERIC Educational Resources Information Center

    Lackéus, Martin; Williams Middleton, Karen

    2015-01-01

    Purpose: The purpose of this paper is to explore how university-based entrepreneurship programs, incorporating real-life venture creation into educational design and delivery, can bridge the gap between entrepreneurship education and technology transfer within the university environment. Design/methodology/approach: Based on a literature review…

  19. Bridging Cultures: Evaluating Teachers' Understanding of Cross-Cultural Conflicts.

    ERIC Educational Resources Information Center

    Trumbull, Elise; Greenfield, Patricia; Quiroz, Blanca; Rothstein-Fisch, Carrie

    The Bridging Cultures Project is a collaboration among several researchers and teachers (n=8) to design professional development activities on the topic of cross-cultural understanding. During the fall of 1996, participating teachers will be given a pre-assessment and post-assessment. The assessments are designed to give some information on how…

  20. Acquisition and Analysis of Dynamic Responses of a Historic Pedestrian Bridge using Video Image Processing

    NASA Astrophysics Data System (ADS)

    O'Byrne, Michael; Ghosh, Bidisha; Schoefs, Franck; O'Donnell, Deirdre; Wright, Robert; Pakrashi, Vikram

    2015-07-01

    Video based tracking is capable of analysing bridge vibrations that are characterised by large amplitudes and low frequencies. This paper presents the use of video images and associated image processing techniques to obtain the dynamic response of a pedestrian suspension bridge in Cork, Ireland. This historic structure is one of the four suspension bridges in Ireland and is notable for its dynamic nature. A video camera is mounted on the river-bank and the dynamic responses of the bridge have been measured from the video images. The dynamic response is assessed without the need of a reflector on the bridge and in the presence of various forms of luminous complexities in the video image scenes. Vertical deformations of the bridge were measured in this regard. The video image tracking for the measurement of dynamic responses of the bridge were based on correlating patches in time-lagged scenes in video images and utilisinga zero mean normalised cross correlation (ZNCC) metric. The bridge was excited by designed pedestrian movement and by individual cyclists traversing the bridge. The time series data of dynamic displacement responses of the bridge were analysedto obtain the frequency domain response. Frequencies obtained from video analysis were checked against accelerometer data from the bridge obtained while carrying out the same set of experiments used for video image based recognition.

  1. Acquisition and Analysis of Dynamic Responses of a Historic Pedestrian Bridge using Video Image Processing

    NASA Astrophysics Data System (ADS)

    O'Byrne, Michael; Ghosh, Bidisha; Schoefs, Franck; O'Donnell, Deirdre; Wright, Robert; Pakrashi, Vikram

    2015-07-01

    Video based tracking is capable of analysing bridge vibrations that are characterised by large amplitudes and low frequencies. This paper presents the use of video images and associated image processing techniques to obtain the dynamic response of a pedestrian suspension bridge in Cork, Ireland. This historic structure is one of the four suspension bridges in Ireland and is notable for its dynamic nature. A video camera is mounted on the river-bank and the dynamic responses of the bridge have been measured from the video images. The dynamic response is assessed without the need of a reflector on the bridge and in the presence of various forms of luminous complexities in the video image scenes. Vertical deformations of the bridge were measured in this regard. The video image tracking for the measurement of dynamic responses of the bridge were based on correlating patches in time-lagged scenes in video images and utilisinga zero mean normalisedcross correlation (ZNCC) metric. The bridge was excited by designed pedestrian movement and by individual cyclists traversing the bridge. The time series data of dynamic displacement responses of the bridge were analysedto obtain the frequency domain response. Frequencies obtained from video analysis were checked against accelerometer data from the bridge obtained while carrying out the same set of experiments used for video image based recognition.

  2. Structural health monitoring results on Tsing Ma, Kap Shui Mun, and Ting Kau bridges

    NASA Astrophysics Data System (ADS)

    Wong, Kai-yuen; Chan, Wai-Yee K.; Man, King-Leung; Mak, W. L. N.; Lau, C. K.

    2000-06-01

    A structural health monitoring system has been installed in the cable-supported bridges located in the West of Hong Kong, i.e. the Tsing Ma Control Area. These cable-supported bridges are the Tsing Ma (Suspension) Bridge, the Kap Shu Mun (Cable- Stayed) Bridge and the Ting Kau (Cable-Stayed Bridge) Bridge. The monitoring system of Tsing Ma Bridge and Kap Shui Mun Bridge has been operated since May 1997, whereas the monitoring system of Ting Kau Bridge has been operated since November 1998. In past years, data received from the monitoring systems have been processed, and analyzed and archived. This paper first briefly outlines the operation of the data processing and analysis, and then presents: (1) the load effects monitoring results such as wind, temperature and traffic (highway and railway), and (2) the bridge responses monitoring results such as displacements, stresses/strains, accelerations and cables forces. Comparisons between monitoring results and design parameters and assumptions for the cable-supported bridges are also presented.

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

    NASA Astrophysics Data System (ADS)

    Arioli, Gianni; Gazzola, Filippo

    2017-01-01

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

  4. Real-time seismic monitoring of the integrated cape girardeau bridge array and recorded earthquake response

    USGS Publications Warehouse

    Celebi, M.

    2006-01-01

    This paper introduces the state of the art, real-time and broad-band seismic monitoring network implemented for the 1206 m [3956 ft] long, cable-stayed Bill Emerson Memorial Bridge in Cape Girardeau (MO), a new Mississippi River crossing, approximately 80 km from the epicentral region of the 1811-1812 New Madrid earthquakes. The bridge was designed for a strong earthquake (magnitude 7.5 or greater) during the design life of the bridge. The monitoring network comprises a total of 84 channels of accelerometers deployed on the superstructure, pier foundations and at surface and downhole free-field arrays of the bridge. The paper also presents the high quality response data obtained from the network. Such data is aimed to be used by the owner, researchers and engineers to assess the performance of the bridge, to check design parameters, including the comparison of dynamic characteristics with actual response, and to better design future similar bridges. Preliminary analyses of ambient and low amplitude small earthquake data reveal specific response characteristics of the bridge and the free-field. There is evidence of coherent tower, cable, deck interaction that sometimes results in amplified ambient motions. Motions at the lowest tri-axial downhole accelerometers on both MO and IL sides are practically free from any feedback from the bridge. Motions at the mid-level and surface downhole accelerometers are influenced significantly by feedback due to amplified ambient motions of the bridge. Copyright ASCE 2006.

  5. Liquid-Bridge Breaking Limits

    NASA Astrophysics Data System (ADS)

    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.

  6. A statistical model of operational impacts on the framework of the bridge crane

    NASA Astrophysics Data System (ADS)

    Antsev, V. Yu; Tolokonnikov, A. S.; Gorynin, A. D.; Reutov, A. A.

    2017-02-01

    The technical regulations of the Customs Union demands implementation of the risk analysis of the bridge cranes operation at their design stage. The statistical model has been developed for performance of random calculations of risks, allowing us to model possible operational influences on the bridge crane metal structure in their various combination. The statistical model is practically actualized in the software product automated calculation of risks of failure occurrence of bridge cranes.

  7. Pulse excitation of bolometer bridges

    NASA Technical Reports Server (NTRS)

    Rusk, S. J.

    1972-01-01

    Driving bolometer bridge by appropriately phased excitation pulses increases signal-to-noise ratio of bolometer sensor which operates on a chopped light beam. Method allows higher applied voltage than is possible by conventional ac or dc excitation.

  8. We Must Be Bridge Builders.

    ERIC Educational Resources Information Center

    Andringa, Robert C.

    1982-01-01

    Higher education, and trustees in particular, must be "bridge builders" among academe, government, and business communities. Trustees must also be the mediators and a reconciling force when the public and independent campuses lose sight of their common cause. (MLW)

  9. TMD-Based Structural Control of High Performance Steel Bridges

    NASA Astrophysics Data System (ADS)

    Kim, Tae Min; Kim, Gun; Kyum Kim, Moon

    2012-08-01

    The purpose of this study is to investigate the effectiveness of structural control using tuned mass damper (TMD) for suppressing excessive traffic induced vibration of high performance steel bridge. The study considered 1-span steel plate girder bridge and bridge-vehicle interaction using HS-24 truck model. A numerical model of steel plate girder, traffic load, and TMD is constructed and time history analysis is performed using commercial structural analysis program ABAQUS 6.10. Results from analyses show that high performance steel bridge has dynamic serviceability problem, compared to relatively low performance steel bridge. Therefore, the structural control using TMD is implemented in order to alleviate dynamic serviceability problems. TMD is applied to the bridge with high performance steel and then vertical vibration due to dynamic behavior is assessed again. In consequent, by using TMD, it is confirmed that the residual amplitude is appreciably reduced by 85% in steady-state vibration. Moreover, vibration serviceability assessment using 'Reiher-Meister Curve' is also remarkably improved. As a result, this paper provides the guideline for economical design of I-girder using high performance steel and evaluates the effectiveness of structural control using TMD, simultaneously.

  10. 77 FR 16784 - General Bridge Regulation; Amendment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-22

    ... SECURITY Coast Guard 33 CFR Part 114, 116, 118 RIN 1625-AB36 General Bridge Regulation; Amendment AGENCY... rulemaking concerning amendments to the general bridge regulations. The rulemaking was initiated to clarify the statutory responsibilities of bridge owners to remove their bridges from navigable waterways...

  11. 75 FR 41281 - Bridge Safety Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-15

    ...FRA is establishing Federal safety requirements for railroad bridges. This final rule requires track owners to implement bridge management programs, which include annual inspections of railroad bridges, and to audit the programs. This final rule also requires track owners to know the safe load capacity of bridges and to conduct special inspections if the weather or other conditions warrant......

  12. OVERVIEW OF BRIDGES WITH WAIKELE CANAL BRIDGE IN CENTER, OR&L ...

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

    OVERVIEW OF BRIDGES WITH WAIKELE CANAL BRIDGE IN CENTER, OR&L BRIDGE IN BACKGROUND. SHOWING THE EARTHEN INCLINE THAT RAISES FARRINGTON HIGHWAY OVER THE FORMER OR&L TRACKS. NOTE THE 1963 WESTBOUND BRIDGE IN THE FOREGROUND. VIEW FACING EAST. - Waikele Canal Bridge and Highway Overpass, Farrington Highway and Waikele Stream, Waipahu, Honolulu County, HI

  13. ASSESSMENT OF CHANNEL STABILITY AT BRIDGE SITES.

    USGS Publications Warehouse

    Brice, James C.; ,

    1984-01-01

    Assessment of channel stability from field study and the comparison of time-sequential aerial photographs provides information that is needed in site selection, bridge design, and countermeasure placement. Channel instability is indicated by bank erosion, progressive degradation (or aggradation) of the streambed, or natural scour and fill of the streambed. Bank erosion rates are related to stream type and are proportional to stream size. Predictions of future rates are based on past rates, as measured on time-sequential photographs or mps, and on the typical behavior of meander loops.

  14. Semiconductor bridge, SCB, ignition of energetic materials

    SciTech Connect

    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.

  15. Hydraulic and geomorphic monitoring of experimental bridge scour mitigation at selected bridges in Utah, 2003-05

    USGS Publications Warehouse

    Kenney, Terry A.; McKinney, Tim S.

    2006-01-01

    Unique bridge scour mitigation designs using concrete A-Jacks were developed by the Utah Department of Transportation and installed at the Colorado River Bridge at State Road 191 and the Green River Bridge at State Road 19. The U.S. Geological Survey monitored stream reaches at these sites by collecting streambed-topography and water-velocity data from 2003 through 2005. These data were acquired annually from a moving boat with an acoustic Doppler current profiler and a differential global positioning system. Raw unordered data were processed and readied for interpolation into organized datasets with DopplerMacros, a set of computer programs. Processed streambed topography data were geostatistically interpolated by using Ordinary Kriging, and inverse distance weighting interpolation was used in the development of the two-dimensional velocity datasets. These organized datasets of topography and velocity were developed for each survey of the two bridge sites. A comparison of the riverbed topography data for each survey was done. An increase in bed elevation related to the installation of the A-Jacks scour countermeasures is evident at the Colorado River Bridge at State Road 191. The three topographic datasets acquired after the installation at the Green River Bridge at State Road 19 show few changes.

  16. A Good Start? The Impact of Texas' Developmental Summer Bridge Program on Student Success

    ERIC Educational Resources Information Center

    Wathington, Heather; Pretlow, Joshua; Barnett, Elisabeth

    2016-01-01

    Summer bridge programs have long been utilized by postsecondary institutions to improve the college readiness of students; however, the research on their effectiveness is limited. This study presents evidence from an experimental study of one summer bridge program model specifically designed for recent high school graduates who placed into…

  17. Integrating modal-based NDE techniques and bridge management systems using quality management

    NASA Astrophysics Data System (ADS)

    Sikorsky, Charles S.

    1997-05-01

    The intent of bridge management systems is to help engineers and managers determine when and where to spend bridge funds such that commerce and the motoring public needs are satisfied. A major shortcoming which states are experiencing is the NBIS data available is insufficient to perform certain functions required by new bridge management systems, such as modeling bridge deterioration and predicting costs. This paper will investigate how modal based nondestructive damage evaluation techniques can be integrated into bridge management using quality management principles. First, quality from the manufacturing perspective will be summarized. Next, the implementation of quality management in design and construction will be reinterpreted for bridge management. Based on this, a theory of approach will be formulated to improve the productivity of a highway transportation system.

  18. A New Multiconstraint Method for Determining the Optimal Cable Stresses in Cable-Stayed Bridges

    PubMed Central

    Asgari, B.; Osman, S. A.; Adnan, A.

    2014-01-01

    Cable-stayed bridges are one of the most popular types of long-span bridges. The structural behaviour of cable-stayed bridges is sensitive to the load distribution between the girder, pylons, and cables. The determination of pretensioning cable stresses is critical in the cable-stayed bridge design procedure. By finding the optimum stresses in cables, the load and moment distribution of the bridge can be improved. In recent years, different research works have studied iterative and modern methods to find optimum stresses of cables. However, most of the proposed methods have limitations in optimising the structural performance of cable-stayed bridges. This paper presents a multiconstraint optimisation method to specify the optimum cable forces in cable-stayed bridges. The proposed optimisation method produces less bending moments and stresses in the bridge members and requires shorter simulation time than other proposed methods. The results of comparative study show that the proposed method is more successful in restricting the deck and pylon displacements and providing uniform deck moment distribution than unit load method (ULM). The final design of cable-stayed bridges can be optimised considerably through proposed multiconstraint optimisation method. PMID:25050400

  19. Fatigue evaluation for Tsing Ma Bridge using structural health monitoring data

    NASA Astrophysics Data System (ADS)

    Chan, Hung-tin Tommy; Ko, Jan Ming; Li, Zhao-Xia

    2001-08-01

    Fatigue assessment for the Tsing Ma Bridge (TMB) are presented based on the British standard BS5400 and the real-time structural health monitoring data under railway loading. TMB, as an essential portion of transport network for the Hong Kong airport, is the longest suspension bridge in the world carrying both highway and railway traffic. The bridge design has been mainly based on BS5400. A structural health monitoring system - Wind and Structural Health Monitoring System (WASHMS) for TMB has been operated since the bridge commissioning in May 1997. In order to assess the fatigue behavior of TMB under railway loading, strain gauges were installed on the bridge deck to measure the strain-time histories as soon as the bridge is loaded by a standard railway loading due to the service of an actual train. The strain-time history data at the critical members are then used to determine the stress spectrum, of which the rainflow method recommended for railway bridges by BS5400 is applied to count cycles of stress range. Miner's law is employed to evaluate fatigue damage and remaining service life of the bridge. The evaluated results of fatigue damage and remaining service life would help us to well understand about the fatigue design of the bridge and status in fatigue accumulation.

  20. A new multiconstraint method for determining the optimal cable stresses in cable-stayed bridges.

    PubMed

    Asgari, B; Osman, S A; Adnan, A

    2014-01-01

    Cable-stayed bridges are one of the most popular types of long-span bridges. The structural behaviour of cable-stayed bridges is sensitive to the load distribution between the girder, pylons, and cables. The determination of pretensioning cable stresses is critical in the cable-stayed bridge design procedure. By finding the optimum stresses in cables, the load and moment distribution of the bridge can be improved. In recent years, different research works have studied iterative and modern methods to find optimum stresses of cables. However, most of the proposed methods have limitations in optimising the structural performance of cable-stayed bridges. This paper presents a multiconstraint optimisation method to specify the optimum cable forces in cable-stayed bridges. The proposed optimisation method produces less bending moments and stresses in the bridge members and requires shorter simulation time than other proposed methods. The results of comparative study show that the proposed method is more successful in restricting the deck and pylon displacements and providing uniform deck moment distribution than unit load method (ULM). The final design of cable-stayed bridges can be optimised considerably through proposed multiconstraint optimisation method.

  1. Efficient field testing for load rating railroad bridges

    NASA Astrophysics Data System (ADS)

    Schulz, Jeffrey L.; Brett C., Commander

    1995-06-01

    As the condition of our infrastructure continues to deteriorate, and the loads carried by our bridges continue to increase, an ever growing number of railroad and highway bridges require load limits. With safety and transportation costs at both ends of the spectrum. the need for accurate load rating is paramount. This paper describes a method that has been developed for efficient load testing and evaluation of short- and medium-span bridges. Through the use of a specially-designed structural testing system and efficient load test procedures, a typical bridge can be instrumented and tested at 64 points in less than one working day and with minimum impact on rail traffic. Various techniques are available to evaluate structural properties and obtain a realistic model. With field data, a simple finite element model is 'calibrated' and its accuracy is verified. Appropriate design and rating loads are applied to the resulting model and stress predictions are made. This technique has been performed on numerous structures to address specific problems and to provide accurate load ratings. The merits and limitations of this approach are discussed in the context of actual examples of both rail and highway bridges that were tested and evaluated.

  2. Chairs, Cars, and Bridges: Teaching Aesthetics from the Everyday

    ERIC Educational Resources Information Center

    Zande, Robin Vande

    2007-01-01

    It is very typical for students in K-12 art education to study aesthetics based on artistic objects. Artistic objects, however, need not be the sole source for aesthetic investigation. In this article, the author discusses the use of designed objects such as chairs, cars, and bridges in the discussion of aesthetic concepts. Students, as consumers…

  3. Academic Wholism: Bridging the Gap between High School and College

    ERIC Educational Resources Information Center

    Giuliano, Barbara; Sullivan, Judith

    2007-01-01

    Without adequate reading comprehension, writing proficiency, math competency, and critical thinking skills, students pursuing higher education are vulnerable to failure. An environmental Science course built around academic wholism is the focus of a summer program designed to bridge the gap between high school and college. Students self-reflect…

  4. Building Bridges between University and Industry: Theory and Practice

    ERIC Educational Resources Information Center

    Meredith, Sandra; Burkle, Martha

    2008-01-01

    Purpose: The purpose of this paper is to examine the level of benefit to learning through developing strong links between universities and industry, and to suggest a methodology for building bridges between university and industry that provides a full learning experience for students. Design/methodology/approach: A case study approach which…

  5. Bridging Team Efforts, Supporting Current and Future Forces

    DTIC Science & Technology

    2010-02-28

    opening to an additional 60’x60’ reinforced concrete pad Capable to test bridges up to 32’ wide and 210’ long Previous Tests Completed M104 Wolverine ...systems – RESET/RECAP Hydraulic and Electric Upgrade at ANAD UNCLASSIFIED M104 Wolverine • Description: – Armored vehicle designed to carry, emplace

  6. Chickamauga National Military Park Tour Roads, Gordon's Slough Bridge, At ...

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

    Chickamauga National Military Park Tour Roads, Gordon's Slough Bridge, At the confluence of Alexander's Bridge Road and Gordon's Slough, southeast of Alexander's Bridge, Fort Oglethorpe, Catoosa County, GA

  7. 2. Elkmont, deck view of corrugated arched bridge. Great ...

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

    2. Elkmont, deck view of corrugated arched bridge. - Great Smoky Mountains National Park Roads & Bridges, Elkmont Vehicle Bridge, Spanning Little River at Elkmont Campground, Gatlinburg, Sevier County, TN

  8. 3. Elkmont, underside detail of corrugated arched bridge. Great ...

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

    3. Elkmont, underside detail of corrugated arched bridge. - Great Smoky Mountains National Park Roads & Bridges, Elkmont Vehicle Bridge, Spanning Little River at Elkmont Campground, Gatlinburg, Sevier County, TN

  9. Study of displacements of a bridge abutment using FEM

    NASA Astrophysics Data System (ADS)

    Wymysłowski, Michał; Kurałowicz, Zygmunt

    2016-06-01

    Steel sheet piles are often used to support excavations for bridge foundations. When they are left in place in the permanent works, they have the potential to increase foundation bearing capacity and reduce displacements; but their presence is not usually taken into account in foundation design. In this article, the results of finite element analysis of a typical abutment foundation, with and without cover of sheet piles, are presented to demonstrate these effects. The structure described is located over the Więceminka river in the town of Kołobrzeg, Poland. It is a single-span road bridge with reinforced concrete slab.

  10. Super-bridges suspended over carbon nanotube cables

    NASA Astrophysics Data System (ADS)

    Carpinteri, Alberto; Pugno, Nicola M.

    2008-11-01

    In this paper the new concept of 'super-bridges', i.e. kilometre-long bridges suspended over carbon nanotube cables, is introduced. The analysis shows that the use of realistic (thus defective) carbon nanotube bundles as suspension cables can enlarge the current limit main span by a factor of ~3. Too large compliance and dynamic self-excited resonances could be avoided by additional strands, rendering the super-bridge anchored as a spider's cobweb. As an example, we have computed the limit main spans of the current existing 19 suspended-deck bridges longer than 1 km assuming them to have substituted their cables with carbon nanotube bundles (thus maintaining the same geometry, with the exception of the length) finding spans of up to ~6.3 km. We thus suggest that the design of the Messina bridge in Italy, which would require a main span of ~3.3 km, could benefit from the use of carbon nanotube bundles. We believe that their use represents a feasible and economically convenient solution. The plausibility of these affirmations is confirmed by a statistical analysis of the existing 100 longest suspended bridges, which follow a Zipf's law with an exponent of 1.1615: we have found a Moore-like (i.e. exponential) law, in which the doubling of the capacity (here the main span) per year is substituted by the factor 1.0138. Such a law predicts that the realization of the Messina bridge using conventional materials will only occur around the middle of the present century, whereas it could be expected in the near future if carbon nanotube bundles were used. A simple cost analysis concludes the paper.

  11. Safety identifying of integral abutment bridges under seismic and thermal loads.

    PubMed

    Easazadeh Far, Narges; Barghian, Majid

    2014-01-01

    Integral abutment bridges (IABs) have many advantages over conventional bridges in terms of strength and maintenance cost. Due to the integrity of these structures uniform thermal and seismic loads are known important ones on the structure performance. Although all bridge design codes consider temperature and earthquake loads separately in their load combinations for conventional bridges, the thermal load is an "always on" load and, during the occurrence of an earthquake, these two important loads act on bridge simultaneously. Evaluating the safety level of IABs under combination of these loads becomes important. In this paper, the safety of IABs--designed by AASHTO LRFD bridge design code--under combination of thermal and seismic loads is studied. To fulfill this aim, first the target reliability indexes under seismic load have been calculated. Then, these analyses for the same bridge under combination of thermal and seismic loads have been repeated and the obtained reliability indexes are compared with target indexes. It is shown that, for an IAB designed by AASHTO LRFD, the indexes have been reduced under combined effects. So, the target level of safety during its design life is not provided and the code's load combination should be changed.

  12. Safety Identifying of Integral Abutment Bridges under Seismic and Thermal Loads

    PubMed Central

    Easazadeh Far, Narges; Barghian, Majid

    2014-01-01

    Integral abutment bridges (IABs) have many advantages over conventional bridges in terms of strength and maintenance cost. Due to the integrity of these structures uniform thermal and seismic loads are known important ones on the structure performance. Although all bridge design codes consider temperature and earthquake loads separately in their load combinations for conventional bridges, the thermal load is an “always on” load and, during the occurrence of an earthquake, these two important loads act on bridge simultaneously. Evaluating the safety level of IABs under combination of these loads becomes important. In this paper, the safety of IABs—designed by AASHTO LRFD bridge design code—under combination of thermal and seismic loads is studied. To fulfill this aim, first the target reliability indexes under seismic load have been calculated. Then, these analyses for the same bridge under combination of thermal and seismic loads have been repeated and the obtained reliability indexes are compared with target indexes. It is shown that, for an IAB designed by AASHTO LRFD, the indexes have been reduced under combined effects. So, the target level of safety during its design life is not provided and the code's load combination should be changed. PMID:25405232

  13. Balanced bridge feedback control system

    NASA Technical Reports Server (NTRS)

    Lurie, Boris J. (Inventor)

    1990-01-01

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

  14. Laser-sustained liquid bridges

    NASA Astrophysics Data System (ADS)

    Casner, A.; Delville, J.-P.

    2004-02-01

    The stabilization of free-standing liquid bridges encounters a fundamental limitation associated to the Rayleigh-Plateau instability. Classically in weightless conditions, a liquid column breaks when its length exceeds its circumference. We overcome this fundamental limitation using a new technique, based on the optical-radiation pressure of a continuous laser wave, to form and stabilize pure dielectric bridges far beyond the instability onset. Since control over aspect ratio and orientation are simply realized by adjusting the waist and the direction of the exciting laser, these laser-sustained liquid columns also behave as reconfigurable optical waveguides and provide an appealing example of self-adapted optical microsystem based on microfluidics.

  15. Excitation Methods for Bridge Structures

    SciTech Connect

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

    1999-02-08

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

  16. Geometry control of long-span continuous girder concrete bridge during construction through finite element model updating

    NASA Astrophysics Data System (ADS)

    Wu, Jie; Yan, Quan-sheng; Li, Jian; Hu, Min-yi

    2016-04-01

    In bridge construction, geometry control is critical to ensure that the final constructed bridge has the consistent shape as design. A common method is by predicting the deflections of the bridge during each construction phase through the associated finite element models. Therefore, the cambers of the bridge during different construction phases can be determined beforehand. These finite element models are mostly based on the design drawings and nominal material properties. However, the accuracy of these bridge models can be large due to significant uncertainties of the actual properties of the materials used in construction. Therefore, the predicted cambers may not be accurate to ensure agreement of bridge geometry with design, especially for long-span bridges. In this paper, an improved geometry control method is described, which incorporates finite element (FE) model updating during the construction process based on measured bridge deflections. A method based on the Kriging model and Latin hypercube sampling is proposed to perform the FE model updating due to its simplicity and efficiency. The proposed method has been applied to a long-span continuous girder concrete bridge during its construction. Results show that the method is effective in reducing construction error and ensuring the accuracy of the geometry of the final constructed bridge.

  17. Animal experiments with the microelectronics neural bridge IC.

    PubMed

    Li, Wenyuan; Pei, Fei; Wang, Zhigong; Lü, Xiaoying

    2012-01-01

    The combination of the neural science and the microelectronics science offers a new way to restore the function of central nervous system. A neural regeneration module is used to be implanted into body to bridge the damaged nerve. A microelectronics neural bridge IC designed in CSMC 0.5□m CMOS process which can detect the neural signal and stimulate the nerve is presented. The neural regeneration module is composed of the microelectronics neural bridge IC and some discrete devices. An animal experiment has been done to check whether the neural signal can be transmitted with the chip normally or not. The animal experiment results suggest that the neural regeneration module can make the neural signal transmit normally.

  18. Seismic Retrofitting of an Existing Steel Railway Bridge by Fluid Viscous Dampers

    NASA Astrophysics Data System (ADS)

    Gangopadhyay, Avijit; Ghosh, Aparna Dey

    2016-09-01

    There are over a lakh of bridges in the Indian Railways, many of which have become seismically deficient, either through aging or due to inadequate seismic design considerations. The extensive damage of bridges all over the world in recent earthquakes has propelled significant advancement in earthquake protection and retrofitting of bridges. Amongst various passive control systems that are reliable as well as cost-effective, Fluid Viscous Dampers (FVDs) are proving to be successful in bridge vibration control. Orificed FVDs, commercially available as Taylor Devices, have already been successfully installed in several bridges worldwide. However, there has been no such application or study related to Indian railway bridges. In this paper, an existing thirty years' old railway bridge in Jharkhand, India, has been analyzed in SAP2000v14 considering reduced stiffness and found deficient when subjected to spectrum-compatible accelerograms. Subsequent retrofitting of the bridge superstructure with FVDs has been carried out and the results indicate substantial reductions in the responses of the bridge deck.

  19. Bridges and Equipment

    DTIC Science & Technology

    2009-09-15

    2-80010 and 2-2-80111. These measurements should be accomplished in each system stowage and transport configuration (truck, trailer, and pallet...required embankment conditions including level, longitudinal/side slope, racked , and bank height differential requirements. Each designated crossing...paragraphs or tables. 4.13 Transportability . 4.13.1 Method . a. As listed in TOP 1-2-50023, plan to test all of the system stowage and

  20. Ground-penetrating radar: A tool for monitoring bridge scour

    USGS Publications Warehouse

    Anderson, N.L.; Ismael, A.M.; Thitimakorn, T.

    2007-01-01

    Ground-penetrating radar (GPR) data were acquired across shallow streams and/or drainage ditches at 10 bridge sites in Missouri by maneuvering the antennae across the surface of the water and riverbank from the bridge deck, manually or by boat. The acquired two-dimensional and three-dimensional data sets accurately image the channel bottom, demonstrating that the GPR tool can be used to estimate and/or monitor water depths in shallow fluvial environments. The study results demonstrate that the GPR tool is a safe and effective tool for measuring and/or monitoring scour in proximity to bridges. The technique can be used to safely monitor scour at assigned time intervals during peak flood stages, thereby enabling owners to take preventative action prior to potential failure. The GPR tool can also be used to investigate depositional and erosional patterns over time, thereby elucidating these processes on a local scale. In certain instances, in-filled scour features can also be imaged and mapped. This information may be critically important to those engaged in bridge design. GPR has advantages over other tools commonly employed for monitoring bridge scour (reflection seismic profiling, echo sounding, and electrical conductivity probing). The tool doesn't need to be coupled to the water, can be moved rapidly across (or above) the surface of a stream, and provides an accurate depth-structure model of the channel bottom and subchannel bottom sediments. The GPR profiles can be extended across emerged sand bars or onto the shore.

  1. Analysis of Bridging Formulae in Transitional Regime

    NASA Astrophysics Data System (ADS)

    Morsa, Luigi; Zuppardi, Gennaro; Schettino, Antonio; Votta, Raffaele

    2011-05-01

    The most suitable method to compute aerodynamic forces of a spacecraft, at first stage of a design, relies on bridging formulae. There are two kinds of bridging formulae: global and local. The global formulae rely on knowledge of spacecraft aerodynamic force coefficients in continuum and in free molecular flow. The local formulae calculate the skin friction and pressure coefficients on the body surface; the global aerodynamic coefficients are then computed by integration. The aim of this work is to analyze the widely accepted local formulae by Potter and by Kotov. To this purpose, a simple body, like a sphere, has been preliminary considered and the results have been compared with those from the DSMC code DS2V. This comparison led to the corrections of the computation of the skin friction and pressure coefficients. These corrections have been applied to the Potter formula. On the other hand the original Kotov formula showed good results for the pressure coefficient at high altitudes. Therefore a merge of the corrected Potter formula and of the Kotov formula has been made. This methodology, called "new" bridging formula, has been successfully applied to sphere. The "new" formula has been also applied to EXPERT and ORION capsules, but it has to be pointed out that, in this application at low altitudes, a failure of the panel method starts to appear. Both local and global coefficients have been compared with the results by the DS2/3V codes. Finally, for these capsules, the global formula by Wilmoth has been also used by tuning the adjustable parameters.

  2. Scour at selected bridge sites in Mississippi

    USGS Publications Warehouse

    Wilson, K.V.

    1995-01-01

    Scour data were collected during 1936-94 at 22 bridge sites in Mississippi. The drainage area of the bridge-scour sites ranged from 60.8 to 5,720 square miles, and the slope in the vicinity of each site ranged from 0.00011 to 0.00163 foot per foot. Measured pier-scour depths ranged from 0.6 to 20.4 feet. Measured total-scour depths at minimum-bed elevation ranged from 5.2 to 29.8 feet. Recurrence intervals of measured streamflow discharges ranged from less than 2 years to about 500 years. All of the Mississippi pier-scour depths were within 2.3 times the normal pier width, which agreed with previous research. Only 12 (6 percent) of the 190 measured pier-scour depths were greater than 1.1 times the normal pier width. Measured pier-scour depths were as much as 2.24 times a normal pier width of 3.3 feet. However, for pier widths greater than about 4 feet, measured pier-scour depths were significantly less than 2.3 times the normal pier width. An envelope-curve equation for the Mississippi pier-scour data was developed by relating pier-scour depth divided by normal pier width to measured approach-flow depth divided by normal pier width. The envelope-curve equation predictions could be used for reasonable verifi- cations of the HEC-18 pier-scour predictions, currently required for the design and mainte- nance of bridges over waterways in Mississippi.

  3. Special Fluid Viscous Dampers For The Messina Strait Bridge

    SciTech Connect

    Colato, Gian Paolo; Infanti, Samuele; Castellano, Maria Gabriella

    2008-07-08

    The Messina Strait Bridge would be the world's longest suspension bridge, with a design earthquake characterised by a PGA value of 0.58 g and a distance between the ipocenter and the bridge of 15 km. Said critical structure of course would need a suitable restraint system for traffic braking loads, wind and seismic actions. Each type of load requires a specific behaviour of the restraint system, making its design a big challenge.The restraint system comprises special types of fluid viscous dampers, installed both in longitudinal and transverse direction, both at the towers and at the anchorages. In seismic conditions they behave as viscous dampers, to reduce the forces on the structural elements and the movements of the bridge deck. But in service dynamic conditions, e.g. under traffic or wind load, the devices shall behave like shock transmission units, thus preventing the longitudinal and transverse movements of the deck.FIP Industriale cooperated with the selected General Contractor, a consortium lead by Impregilo, in the design of said viscous dampers. This paper describes the main features of said devices.

  4. Thermal Control Using Liquid-Metal Bridge Switches

    NASA Technical Reports Server (NTRS)

    Hirsa, Amir H.; Olles, Joseph; Tilger, Christopher

    2013-01-01

    A short term effort (3-months) was undertaken to demonstrate the feasibility of a novel method to locally control the heat transfer rate and demonstrate the potential to achieve a turndown ratio of approximately 10:1. The technology had to be demonstrated to be at a TRL of 2-3, with a plan to advance it to a TRL 5-6. Here, we show that the concept recently developed in our laboratory, namely the pinned-contact, double droplet switch made by overfilling a hole drilled in a suitable substrate can be implemented with a low-melting temperature metal. When toggled near a second substrate, a liquid bridge can be reversibly connected or disconnected, on demand. We have shown experimentally that liquid-metal bridge switches can be made from gallium with a suitable choice of substrate materials, activation strategies, and control techniques. Individual as well as arrays of gallium bridge switches were shown to be feasible and can be robustly controlled. The very short response time of the bridge connection and disconnection (on the order of 1 millisecond) provides for utility in a wide range of applications. The liquid bridge switches may be controlled actively or passively. We have shown through computations and analysis that liquid bridge switches provide locally large turndown ratios (on the order of 103:1), so a relatively sparse packing of them would be needed to obtain the desired turndown ratio of 10:1. For the laboratory demonstrations, pressure activation was utilized. Simple designs for a passive control strategy are presented which are highly attractive for several reasons, including i) large turndown ratio, ii) no solid-moving parts, and iii) stable operation. Finally, we note that passive systems do not require any electronics for their control. This along with the relatively small molecular weight of candidate materials for the system, makes for a robust design outside of Earth?s magnetic field, where spacecraft are subject to significant radiation bombardment.

  5. NASA Now: Operation IceBridge

    NASA Video Gallery

    During this NASA Now program, you'€™ll meet Michael Studinger, Project Scientist for Operation IceBridge. He'€™ll describe the purpose of the IceBridge campaign and how the campaign objectives will...

  6. Asymmetric capillary bridges between contacting spheres.

    PubMed

    Farmer, Timothy P; Bird, James C

    2015-09-15

    When a drop of liquid wets two identical solid spheres, the liquid forms a capillary bridge between the spheres to minimize surface energy. In the absence of external forces, these bridges are typically assumed to be axisymmetric, and the shape that minimizes surface energy can be calculated analytically. However under certain conditions, the bridge is axisymmetrically unstable, and migrates to a non-axisymmetric configuration. The goal of this paper is to characterize these non-axisymmetric capillary bridges. Specifically, we numerically calculate the shape of the capillary bridge between two contacting spheres that minimizes the total surface energy for a given volume and contact angle and compare to experiments. When the bridge is asymmetric, finite element calculations demonstrate that the shape of the bridge is spherical. In general, the bridge shape depends on both volume and contact angle, yet we find the degree of asymmetry is controlled by a single parameter.

  7. Substructure Main Bridge, Piers B & C Huey ...

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

    Substructure - Main Bridge, Piers B & C - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  8. A Bridge to the Future

    ERIC Educational Resources Information Center

    Anderson, Richard

    2008-01-01

    Career and technical education (CTE) has a promising future at Darlington (WI) High School. In this article, the author describes how a class bridge project became a real-world, project-based learning opportunity involving higher-level thinking skills that are at the core of CTE at his school. It began when a local citizen approached him at the…

  9. THE BRIDGE PROJECT FOLLOWUP STUDY.

    ERIC Educational Resources Information Center

    GREENBERG, HAROLD; AND OTHERS

    AN EXPERIMENT CONDUCTED AT THE JUNIOR HIGH SCHOOL LEVEL IN NEW YORK CITY TO EVALUATE THE EFFECTIVENESS OF A NEW KIND OF LEARNING ENVIRONMENT ON THE EDUCATION OF DISADVANTAGED YOUTH WAS UNDERTAKEN AS A FOLLOWUP TO THE "BRIDGE" PROJECT. THE FUNDAMENTALS INVOLVED USING A NEW TYPE OF TEAM-TEACHING INSTRUCTION IN THE AREAS OF ENGLISH,…

  10. Family Literacy in Bridge Housing.

    ERIC Educational Resources Information Center

    Goodwill Industries of Pittsburgh, PA.

    A project proposed to demonstrate an effective delivery system for providing family literacy services to homeless parents of young children by taking the "Read Me a Story" program directly into bridge housing sites where the families resided. The approach offered was the direct parent/indirect child model. The curriculum came from…

  11. A Rapidly Deployable Bridge System

    DTIC Science & Technology

    2013-01-15

    A Rapidly Deployable Bridge System Gareth R. Thomas1 and Bernard J. Sia2 1ATA Engineering, 11995 El Camino Real, San Diego, CA 92130; PH (858) 480...PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) ATA Engineering,11995 El Camino Real,San Diego,CA,92130 8. PERFORMING ORGANIZATION REPORT NUMBER

  12. Instability of the capillary bridge

    NASA Astrophysics Data System (ADS)

    Pare, Gounseti; Hoepffner, Jerome

    2014-11-01

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

  13. Binuclear Phthalocyanines with Aromatic Bridges

    DTIC Science & Technology

    1989-03-01

    successful. (Scheme 2) Synthesis of Binuclear Phthalocyanines Covalently Bridged by Anthracene The coupling reaction of aromatic halides using elemental...available (16), it Is not active enough to undergo the desired cross coupling reaction . Less electropositive arylzinc derivatives can tolerate various electro...philic functional groups such as nitriles and esters (17). These organo- metallic reagents readily undergo cross coupling reaction with aryl halides

  14. North & South Elevations and Bridge Plan Chickamauga National ...

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

    North & South Elevations and Bridge Plan - Chickamauga National Military Park Tour Roads, Gordon's Slough Bridge, At the confluence of Alexander's Bridge Road and Gordon's Slough, southeast of Alexander's Bridge, Fort Oglethorpe, Catoosa County, GA

  15. 28. Under ninth bridge, view to concrete dam and eighth ...

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

    28. Under ninth bridge, view to concrete dam and eighth bridge in background during heavy rain, view to the SW. - Vicksburg National Military Park Roads & Bridges, Melan Arch Bridges, Spanning various tributaries at Confederate Avenue, Vicksburg, Warren County, MS

  16. 21. View of Clark Fork Vehicle Bridge facing west. Looking ...

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

    21. View of Clark Fork Vehicle Bridge facing west. Looking at bridge deck, guard rail, juncture of two bridge spans. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

  17. 47 CFR 80.309 - Watch required by the Bridge-to-Bridge Act.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Watch required by the Bridge-to-Bridge Act. 80... RADIO SERVICES STATIONS IN THE MARITIME SERVICES Safety Watch Requirements and Procedures Ship Station Safety Watches § 80.309 Watch required by the Bridge-to-Bridge Act. In addition to the watch...

  18. 47 CFR 80.309 - Watch required by the Bridge-to-Bridge Act.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Watch required by the Bridge-to-Bridge Act. 80... RADIO SERVICES STATIONS IN THE MARITIME SERVICES Safety Watch Requirements and Procedures Ship Station Safety Watches § 80.309 Watch required by the Bridge-to-Bridge Act. In addition to the watch...

  19. 47 CFR 80.309 - Watch required by the Bridge-to-Bridge Act.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Watch required by the Bridge-to-Bridge Act. 80... RADIO SERVICES STATIONS IN THE MARITIME SERVICES Safety Watch Requirements and Procedures Ship Station Safety Watches § 80.309 Watch required by the Bridge-to-Bridge Act. In addition to the watch...

  20. 47 CFR 80.309 - Watch required by the Bridge-to-Bridge Act.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Watch required by the Bridge-to-Bridge Act. 80... RADIO SERVICES STATIONS IN THE MARITIME SERVICES Safety Watch Requirements and Procedures Ship Station Safety Watches § 80.309 Watch required by the Bridge-to-Bridge Act. In addition to the watch...

  1. 47 CFR 80.309 - Watch required by the Bridge-to-Bridge Act.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Watch required by the Bridge-to-Bridge Act. 80... RADIO SERVICES STATIONS IN THE MARITIME SERVICES Safety Watch Requirements and Procedures Ship Station Safety Watches § 80.309 Watch required by the Bridge-to-Bridge Act. In addition to the watch...

  2. OVERVIEW OF BRIDGES WITH OR&L BRIDGE IN CENTER, WAIKELE CANAL ...

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

    OVERVIEW OF BRIDGES WITH OR&L BRIDGE IN CENTER, WAIKELE CANAL BRIDGE IN BACKGROUND. SHOWING THE EARTHEN INCLINE THAT RAISES FARRINGTON HIGHWAY OVER THE FORMER OR&L TRACKS. VIEW FACING SOUTHWEST. - Waikele Canal Bridge and Highway Overpass, Farrington Highway and Waikele Stream, Waipahu, Honolulu County, HI

  3. 77 FR 53251 - Annual Materials Report on New Bridge Construction and Bridge Rehabilitation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-31

    ... Rehabilitation AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Notice. SUMMARY: Section 1114 of the... used in new Federal-aid bridge construction and bridge rehabilitation projects. As part of the SAFETEA... bridge construction and bridge rehabilitation projects. Data on Federal-aid and non-Federal-aid...

  4. Bridge Programs in Illinois: Results of the 2010 Illinois Bridge Status Survey

    ERIC Educational Resources Information Center

    Taylor, J. L.; Harmon, T.

    2010-01-01

    This report provides a summary of major results of the Illinois Bridge Status Survey, administered online between April and June 2010. The purpose of the survey was to understand the extent to which bridge programs are being implemented in Illinois, as well as to build an online directory of bridge programs. Bridge programs are an emerging…

  5. Capacitance discharge system for ignition of Single Bridge Apollo Standard Initiators (SBASI)

    NASA Technical Reports Server (NTRS)

    Ward, R. D.

    1974-01-01

    The design support data developed during the single bridge Apollo standard initiator (SBASI) program are presented. A circuit was designed and bread-board tested to verify operational capabilities of the circuit. Test data, design criteria, weight, and reliability trade-off considerations, and final design recommendations are reported.

  6. Structural Bridges through Fold Space

    PubMed Central

    Edwards, Hannah; Deane, Charlotte M.

    2015-01-01

    Several protein structure classification schemes exist that partition the protein universe into structural units called folds. Yet these schemes do not discuss how these units sit relative to each other in a global structure space. In this paper we construct networks that describe such global relationships between folds in the form of structural bridges. We generate these networks using four different structural alignment methods across multiple score thresholds. The networks constructed using the different methods remain a similar distance apart regardless of the probability threshold defining a structural bridge. This suggests that at least some structural bridges are method specific and that any attempt to build a picture of structural space should not be reliant on a single structural superposition method. Despite these differences all representations agree on an organisation of fold space into five principal community structures: all-α, all-β sandwiches, all-β barrels, α/β and α + β. We project estimated fold ages onto the networks and find that not only are the pairings of unconnected folds associated with higher age differences than bridged folds, but this difference increases with the number of networks displaying an edge. We also examine different centrality measures for folds within the networks and how these relate to fold age. While these measures interpret the central core of fold space in varied ways they all identify the disposition of ancestral folds to fall within this core and that of the more recently evolved structures to provide the peripheral landscape. These findings suggest that evolutionary information is encoded along these structural bridges. Finally, we identify four highly central pivotal folds representing dominant topological features which act as key attractors within our landscapes. PMID:26372166

  7. BRIDGES for Young Adolescents in North Dakota.

    ERIC Educational Resources Information Center

    Harris, Mary McDonnell

    The BRIDGES Project was initiated to explore ways for North Dakota to provide young people with stronger bridges from childhood to adulthood. This report summarizes recommendations of the 1990-91 Governor's Task Force on Early Adolescence. The recommendations concern practical actions for the building of bridges by the following groups: (1)…

  8. Building Bridges One Line at a Time

    ERIC Educational Resources Information Center

    Grigsby, Cathy Murray

    2012-01-01

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

  9. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., if the bridge is a legally approved structure, be made as routine maintenance without approval of the... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES...

  10. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., if the bridge is a legally approved structure, be made as routine maintenance without a formal permit... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES...

  11. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., if the bridge is a legally approved structure, be made as routine maintenance without a formal permit... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES...

  12. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., if the bridge is a legally approved structure, be made as routine maintenance without a formal permit... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES...

  13. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., if the bridge is a legally approved structure, be made as routine maintenance without approval of the... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES...

  14. Health monitoring of precast bridge deck panels reinforced with glass fiber reinforced polymer bars

    NASA Astrophysics Data System (ADS)

    Ries, James Mcdaniel

    The Beaver Creek Bridge on US highway 6 is the pilot project for Glass Fiber Reinforced Polymer (GFRP) bridge decks and posttensioned bridge decks in the state of Utah. The bridge was built in 2009, using accelerated bridge construction practices, including the use of precast prestressed girders, as well as precast decking. The westbound bridge decking was composed of 12 precast panels each measuring 41'-5" long, 6'-10" wide, and 9¼" thick, and weighing approximately 33 kips. At the time, these panels were the longest GFRP panels in the United States. The Utah Department of Transportation has decided to evaluate GFRP reinforcing bars as an alternative to steel rebar in this bridge deck. The hope is to increase the lifespan of bridge decks to match the service life of the entire bridge. Due to the nature of the GFRP bars, the panels were lifted at four points using straps instead of imbedded anchors. During the four-point lifting, the panels exhibited small deflections and strains; furthermore, no cracks larger than hairline cracks were found in the panels after lifting. The Beaver Creek Bridge deck is the first precast deck in the state of Utah to be posttensioned in the direction of traffic. Posttensioning bridge decks is expected to become the norm in the state of Utah. The posttensioning resulted in increased continuity between panels. In order to quantify the expected performance of the bridge during its service life, a truck load test was performed. The truck load test was comprised of a static and dynamic test. During the truck load test, the bridge experienced deflections in the panels which were 93% below design values. Girder deflections were also small. The use of GFRP bars has the potential to extend the life of bridge decks exposed to deicing salts from 45 years to 100 years, while only requiring an increased capital cost in the bridge of 8%. Furthermore, the use of GFRP bars in conjunction with accelerated building practices has the potential to

  15. 33 CFR 115.70 - Advance approval of bridges.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  16. 33 CFR 115.70 - Advance approval of bridges.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Advance approval of bridges. 115... BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.70 Advance approval of bridges. (a) The General Bridge Act of 1946 requires the approval of the location and plans of bridges...

  17. 33 CFR 118.100 - Retroreflective panels on bridge piers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Retroreflective panels on bridge... SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.100 Retroreflective panels on bridge piers. The... 12 inches square. (c) To mark bridge piers or channel sides on bridges not required to have...

  18. 49 CFR 237.111 - Review of bridge inspection reports.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Review of bridge inspection reports. 237.111... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.111 Review of bridge inspection reports. Bridge inspection reports shall be reviewed by railroad bridge supervisors and...

  19. 33 CFR 115.70 - Advance approval of bridges.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Advance approval of bridges. 115... BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.70 Advance approval of bridges. (a) The General Bridge Act of 1946 requires the approval of the location and plans of bridges...

  20. 49 CFR 237.111 - Review of bridge inspection reports.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Review of bridge inspection reports. 237.111... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.111 Review of bridge inspection reports. Bridge inspection reports shall be reviewed by railroad bridge supervisors and...

  1. 33 CFR 115.70 - Advance approval of bridges.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Advance approval of bridges. 115... BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.70 Advance approval of bridges. (a) The General Bridge Act of 1946 requires the approval of the location and plans of bridges...

  2. 33 CFR 115.70 - Advance approval of bridges.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Advance approval of bridges. 115... BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.70 Advance approval of bridges. (a) The General Bridge Act of 1946 requires the approval of the location and plans of bridges...

  3. 49 CFR 237.111 - Review of bridge inspection reports.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Review of bridge inspection reports. 237.111... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.111 Review of bridge inspection reports. Bridge inspection reports shall be reviewed by railroad bridge supervisors and...

  4. 33 CFR 118.100 - Retroreflective panels on bridge piers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Retroreflective panels on bridge... SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.100 Retroreflective panels on bridge piers. The... 12 inches square. (c) To mark bridge piers or channel sides on bridges not required to have...

  5. 49 CFR 237.109 - Bridge inspection records.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Bridge inspection records. 237.109 Section 237.109..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.109 Bridge inspection records... performed on those bridges under this part. (b) Each record of an inspection under the bridge...

  6. 49 CFR 237.111 - Review of bridge inspection reports.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Review of bridge inspection reports. 237.111... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.111 Review of bridge inspection reports. Bridge inspection reports shall be reviewed by railroad bridge supervisors and...

  7. 31. Photographic copy of drawing showing profile of bridge after ...

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

    31. Photographic copy of drawing showing profile of bridge after the 1888-1889 and 1899-1900 reconstructions; also shows profile of bridge before 1888 (Martin Sigvart Grytbak, Wabasha St. Bridge, Formerly St. Paul Bridge, 1919); profile of Wabasha street bridge - Wabasha Street Bridge, Spanning Mississippi River at Wabasha Street, Saint Paul, Ramsey County, MN

  8. 23 CFR 650.409 - Evaluation of bridge inventory.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.409 Evaluation of bridge inventory. (a) Sufficiency rating of bridges. Upon receipt and evaluation of the bridge... 23 Highways 1 2010-04-01 2010-04-01 false Evaluation of bridge inventory. 650.409 Section...

  9. 23 CFR 650.409 - Evaluation of bridge inventory.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.409 Evaluation of bridge inventory. (a) Sufficiency rating of bridges. Upon receipt and evaluation of the bridge... 23 Highways 1 2011-04-01 2011-04-01 false Evaluation of bridge inventory. 650.409 Section...

  10. 23 CFR 650.409 - Evaluation of bridge inventory.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.409 Evaluation of bridge inventory. (a) Sufficiency rating of bridges. Upon receipt and evaluation of the bridge... 23 Highways 1 2014-04-01 2014-04-01 false Evaluation of bridge inventory. 650.409 Section...

  11. 23 CFR 650.409 - Evaluation of bridge inventory.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.409 Evaluation of bridge inventory. (a) Sufficiency rating of bridges. Upon receipt and evaluation of the bridge... 23 Highways 1 2013-04-01 2013-04-01 false Evaluation of bridge inventory. 650.409 Section...

  12. 23 CFR 650.409 - Evaluation of bridge inventory.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.409 Evaluation of bridge inventory. (a) Sufficiency rating of bridges. Upon receipt and evaluation of the bridge... 23 Highways 1 2012-04-01 2012-04-01 false Evaluation of bridge inventory. 650.409 Section...

  13. Performance analysis of LAN bridges and routers

    NASA Technical Reports Server (NTRS)

    Hajare, Ankur R.

    1991-01-01

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

  14. Creep and shrinkage effects on integral abutment bridges

    NASA Astrophysics Data System (ADS)

    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

  15. NASDS- NASTRAN/DISCOS/SAMSAN DMAP BRIDGING PROGRAM

    NASA Technical Reports Server (NTRS)

    Frisch, H. P.

    1994-01-01

    The design of a controller for a flexible structure requires an ability to obtain flexible body data in a format compatible with design and performance evaluation methods. The control designer may have to work with several different programs to obtain all the data and capabilities he needs. The NASTRAN/DISCOS/SAMSAN bridging program and its associated data file processor provide the flexible structure control designer with a means of tying together the following programs: 1) the NASA Structural Analysis (NASTRAN) system which provides general finite element and matrix manipulation capabilities for the analysis of structures, 2) the Dynamic Interaction Simulation of Controls and Structure (DISCOS) program which provides for the time and frequency domain analysis of any dynamic system that can be modeled as a system of interconnected rigid and flexible bodies, and 3) the SAMSAN library which provides a self-consistent set of algorithms for the support of large-order controls system design and evaluation studies with an emphasis on sampled system analysis. The NASTRAN/DISCOS/SAMSAN bridging program allows the engineer to integrate these three programs into a complete package for the design and analysis of flexible structure controllers. The NASTRAN/DISCOS/SAMSAN bridging program and its associated data file processor may be used to obtain all of the data necessary for defining a flexible body to DISCOS or to any program developed using the SAMSAN library. The bridging program consists of a NASTRAN DMAP sequence which may be used to obtain a variety of different types of modal data including standard, Craig-Bampton, augmented body, and boundary compliance. The user may also request the generation of the following: mass, stiffness, damping, and constraint matrices; data for fine to coarse mesh mass distribution interpolation programs; modal damping, modal observability/ controllability matrices; coarse or fine mesh modal data; and an assortment of matrices useful for

  16. Problems associated with nondestructive evaluation of bridges

    NASA Astrophysics Data System (ADS)

    Prine, David W.

    1995-05-01

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

  17. Diode-quad bridge circuit means

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

    Diode-quad bridge circuit means is described for use as a transducer circuit or as a discriminator circuit. It includes: (1) a diode bridge having first, second, third, and fourth bridge terminals consecutively coupled together by four diodes polarized in circulating relationship; (2) a first impedance connected between the second bridge terminal and a circuit ground; (3) a second impedance connected between the fourth bridge terminal and the circuit ground; (4) a signal source having a first source terminal capacitively coupled to the first and third bridge terminals, and a second source terminal connected to the circuit ground; and (5) an output terminal coupled to the first bridge terminal and at which an output signal may be taken.

  18. Strengthening Bridges with Prestressed CFRP Strips

    NASA Astrophysics Data System (ADS)

    Siwowski, Tomasz; Żółtowski, Piotr

    2012-06-01

    Limitation of bridge's carrying bearing capacity due to aging and deterioration is a common problem faced by road administration and drivers. Rehabilitation of bridges including strengthening may be applied in order to maintain or upgrade existing bridge parameters. The case studies of strengthening of two small bridges with high modulus prestressed CFRP strips have been presented in the paper. The first one - reinforced concrete slab bridge - and the other - composite steel-concrete girder bridge - have been successfully upgraded with quite new technology. In both cases the additional CFRP reinforcement let increasing of bridge carrying capacity from 15 till 40 metric tons. The CFRP strip prestressing system named Neoxe Prestressing System (NPS), developed by multi-disciplinary team and tested at full scale in Rzeszow University of Technology, has been also described in the paper.

  19. New oxa-bridged macrocycles.

    PubMed

    Panten, Johannes; Surburg, Horst; Hölscher, Bernd

    2008-06-01

    In creating new aroma molecules, the fragrance chemist can make use of several tools: receptor or combinatorial research as well as lead structure optimization of existing chemicals or substances from the natural pool. Sometimes, it is also possible to discover new structures via another way: the careful analysis of existing products and their production processes. In analyzing the production process of 1-oxacyclohexadecan-2-one (6), we identified at least two new oxa-bridged macrocyclic molecules. In continuation, these results inspired us to synthesize and evaluate more representatives with similar structures. In this contribution, presented at the RSC/SCI conference 'flavours & fragrances 2007' in London, September 24-26, 2007, the synthesis and olfactory properties of several new oxa-bridged macrocycles will be introduced and discussed.

  20. DNA-bridged Chiroplasmonic Assemblies of Nanoparticles

    NASA Astrophysics Data System (ADS)

    Kotov, Nicholas

    2015-03-01

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

  1. Talent Management: Bridging the Gap

    DTIC Science & Technology

    2015-06-12

    incentivize officers to remain in the force. When Army career expectations go unfulfilled, talented officers potentially reach out to the private sector...across multiple career fields, and the implications of the “up-or-out” career model. The Solutions Section proposes opportunities to bridge identified...requirements, the existing evaluation system, and officer management across multiple career fields, and the implications of the “up-or-out” career

  2. Rupture work of pendular bridges.

    PubMed

    de Boer, P C T; de Boer, M P

    2008-01-01

    Capillary bridging can generate substantial forces between solid surfaces. Impacted technologies and sciences include micro- and nanomachining, disk drive interfaces, scanning probe microscopy, biology, and granular mechanics. Existing calculations of the rupture work of capillary bridges do not consider the thermodynamics relating to the evaporation that can occur in the case of volatile liquids. Here, we show that the occurrence of evaporation decreases the rupture work by a factor of about 2. The decrease arises from heat taken from the surroundings that is converted into work. The treatment is based on a thermodynamic control-volume analysis of the pendular bridge geometry. We extend the mathematical formulation of Orr et al., solving the meniscus problem exactly for non-wetting surfaces. The extension provides analytical results for conditions at the rupture point and at a possible inflection point and for the rupture work. A simple equation (eq 32) is shown to fit the rupture work for the two cases over a meniscus curvature range of 3 orders of magnitude. Coefficients for the equation are given in tabular form for different contact angle pairs.

  3. Cochleates bridged by drug molecules.

    PubMed

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

    2008-11-03

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

  4. Fabry-Perot sensors for the monitoring of FRP reinforced bridge decks

    NASA Astrophysics Data System (ADS)

    Benmokrane, Brahim; Quirion, Marco; El-Salakawy, Ehab; Debaiky, Ahmed S.; Lackey, Tom

    2004-07-01

    The extensive use of deicing salts in Canada during winter times is identified as the main reason behind the deterioration of highway bridges and parking garages. To fight this infrastructure crisis, Fibre Reinforced Polymers (FRP) has become a very attractive alternative to traditional reinforcing steel due to their non-corrosive nature and light weight. The replacement of steel with Glass FRP bars in bridge deck slabs has been extensively researched in the last few years. This paper presents the first efforts to implement these bars in two highway bridges in Quebec, Canada, and Vermont, USA. These projects are aimed to prove the feasibility of using GFRP bars in bridge construction. GFRP bars were used as reinforcement for parts of the deck slabs in the two bridges while traditional steel was used in the remaining parts. Fibre Optic Sensors (FOS) were used to measure strains in the concrete, reinforcing bars and steel girders. The sensors were surface mounted on the bars or steel girders using standard glue, or embedded in concrete. Static and dynamic testing of the bridges was done using loaded trucks placed for maximum stresses. The design, construction, testing, and results obtained from the bridges are briefly outlined in this paper. The results indicated the accuracy of the sensors and their feasibility for bridge construction and remote monitoring.

  5. Study on the relationship between cyclodextrin glycosyltransferase's thermostability and salt bridge by molecular dynamics simulation.

    PubMed

    Fu, Yi; Ding, Yanrui; Chen, Zhiguo; Sun, Jun; Fang, Wei; Xu, Wenbo

    2010-11-01

    Cyclodextrin glycosyltransferase (EC 2.4.1.19, CGTase) is an important industrial enzyme in the production of cyclodextrins. Thermal stability is of great importance for this enzyme. Rational design of thermostable variants of mesophilic proteins is well motivated. In this work, molecular dynamics simulations have been performed to study thermal stabilization of CGTase protein via electrostatic interactions of salt bridges. To predict behaviors of the salt bridges engineered into a mesophilic protein to increase stability, in silico mutant of CGTase from the mesophilic Bacillus macerans is generated. Dynamic motions of salt bridges in thermal unstable regions are monitored during the simulations. Among the five salt bridges, Lys88-Glu91, Asp296-Arg335 and Arg336-Asp370 are found to be more important for stability than the others. Especially, the region C is stabilized by a well-organized strong multiple salt bridge interactions. The results reveal that salt bridges involved in thermal unstable regions are relatively strong and prone to be tightened at elevated temperature, which can hold the stable conformation of the spatial neighborhood. Meanwhile, we use the heat capacity and total energy as the measure of stability difference between the original and its mutant variant, and then, quantify the contribution of salt bridges in thermal unstable regions for the mutant protein. Therefore, the viable computational strategy has been demonstrated to improve thermal stability of the mesophilic CGTase by introducing stable salt bridge interactions into its thermal unstable regions and it can be universally applied to other enzymes.

  6. Field dynamic testing on a Cyprus concrete highway bridge using Wireless Sensor Network (WSN)

    NASA Astrophysics Data System (ADS)

    Votsis, Renos A.; Kyriakides, Nicholas; Tantele, Elia A.; Chrysostomou, Christis Z.; Onoufriou, Toula

    2014-08-01

    The aims of the bridge management authorities are to ensure that bridges fulfil their purpose and functionality during their design life. So, it is important to identify and quantify the deterioration of the structural condition early so that a timely application of an intervention will avoid more serious problems and increased costs at a later stage. A measure to enhance the effectiveness of the existing structural evaluation by visual inspection is instrumental monitoring using sensors. The activities performed in this process belong to the field of Structural Health Monitoring (SHM). The SHM offers opportunities for continuous or periodic monitoring on bridges and technological advances allow nowadays the employment of wireless sensors networks (WSN) for this task. A SHM application using WSN was implemented on a multi-span reinforced concrete (RC) highway bridge in Limassol with the objective to study its dynamic characteristics and performance. Part of the specific bridge will be replaced and this offered a unique opportunity for measurements before and after construction so that apparent changes in the dynamic characteristics of the bridge will be identified after the repairing work. The measurements provided indications on the frequencies and mode shapes of the bridge and the response amplitude during the passing of traffic. The latter enabled the investigation of the dependency of the bridge's structural damping to the amplitude of vibration induced by the passing of traffic. The results showed that as the excitation increases the magnitude of modal damping increases as well.

  7. Human-simulated intelligent control of train braking response of bridge with MRB

    NASA Astrophysics Data System (ADS)

    Li, Rui; Zhou, Hongli; Wu, Yueyuan; Wang, Xiaojie

    2016-04-01

    The urgent train braking could bring structural response menace to the bridge under passive control. Based on the analysis of breaking dynamics of a train-bridge vibration system, a magnetorheological elastomeric bearing (MRB) whose mechanical parameters are adjustable is designed, tested and modeled. A finite element method (FEM) is carried out to model and optimize a full scale vibration isolation system for railway bridge based on MRB. According to the model above, we also consider the effect of different braking stop positions on the vibration isolation system and classify the bridge longitudinal vibration characteristics into several cases. Because the train-bridge vibration isolation system has multiple vibration states and strongly coupling with nonlinear characteristics, a human-simulated intelligent control (HSIC) algorithm for isolating the bridge vibration under the impact of train braking is proposed, in which the peak shear force of pier top, the displacement of beam and the acceleration of beam are chosen as control goals. The simulation of longitudinal vibration control system under the condition of train braking is achieved by MATLAB. The results indicate that different braking stop positions significantly affect the vibration isolation system and the structural response is the most drastic when the train stops at the third cross-span. With the proposed HSIC smart isolation system, the displacement of bridge beam and peak shear force of pier top is reduced by 53.8% and 34.4%, respectively. Moreover, the acceleration of bridge beam is effectively controlled within limited range.

  8. Vehicle bridge interaction dynamics and potential applications

    NASA Astrophysics Data System (ADS)

    Yang, Y. B.; Lin, C. W.

    2005-06-01

    The dynamic interaction between a moving vehicle and the sustaining bridge is studied. By the method of modal superposition, closed-form solutions are obtained for the vertical responses of both the bridge and moving vehicle, assuming the vehicle/bridge mass ratio to be small. For both the bridge and vehicle responses, it is confirmed that rather accurate solutions can be obtained by considering only the first mode. The displacement, velocity, and acceleration of the bridge are governed at different extents by two sets of frequencies, i.e., the driving frequency of the vehicle and natural frequencies of the bridge. From the spectrum for the bridge displacement, the vehicle speeds can be shown to be associated with some low-frequency pikes. On the other hand, the vehicle responses are governed by five distinct frequencies that appear as driving frequencies, vehicle frequency, and bridge frequencies with shift. From the vehicle's acceleration spectrum, the first bridge frequency (with shift) is shown to have rather high visibility and can be easily identified. The effects of damping of the vehicle and bridge are evaluated in the numerical studies. Potential applications of the present results, as well as further researches required, are also indicated in the paper.

  9. Non-Seismology Seismology: Using QuakeCatchers to Analyze the Frequency of Bridge Vibrations

    NASA Astrophysics Data System (ADS)

    Courtier, A. M.; Constantin, C.; Wilson, C. F.

    2013-12-01

    We conducted an experiment to test the feasibility of measuring seismic waves generated by traffic near James Madison University. We used QuakeCatcher seismometers (originally designed for passive seismic measurement) to measure vibrations associated with traffic on a wooden bridge as well as a nearby concrete bridge. This experiment was a signal processing exercise for a student research project and did not draw any conclusions regarding bridge safety or security. The experiment consisted of two temporary measurement stations comprised of a laptop computer and a QuakeCatcher - a small seismometer that plugs directly into the laptop via a USB cable. The QuakeCatcher was taped to the ground at the edge of the bridge to achieve good coupling, and vibrational events were triggered repeatedly with a control vehicle to accumulate a consistent dataset of the bridge response. For the wooden bridge, the resulting 'seismograms' were converted to Seismic Analysis Code (SAC) format and analyzed in MATLAB. The concrete bridge did not generate vibrations significant enough to trigger the recording mechanism on the QuakeCatchers. We will present an overview of the experimental design and frequency content of the traffic patterns, as well as a discussion of the instructional benefits of using the QuakeCatcher sensors in this non-traditional setting.

  10. Bridging Bilingual and Special Education: Opportunities for Transformative Change in Teacher Preparation Programs

    ERIC Educational Resources Information Center

    Ochoa, Alberto M.; Brandon, Regina R.; Cadiero-Kaplan, Karen; Ramírez, Pablo C.

    2014-01-01

    This article reports on the design and performance of ALAS (Acquisition of Language Skills and Academic Literacy) Teacher Education Project designed to bridge Biliteracy and Special Education teacher preparation. ALAS was designed by faculty in two higher education departments engaged in teacher preparation to respond to California's need for…

  11. Large telescopes and the art of bridge building

    NASA Astrophysics Data System (ADS)

    Kärcher, H. J.

    2008-07-01

    In the last decade the evolution of large or extreme large earthbound optical telescopes speeded up in an unforeseen manner. The technological development is driven by the issues of the complex and challenging active and adaptive optics. But the design of the telescope structure and mechanics - as the backbone of the optics - is also increasing in the importance for costs and later performance. Structural mechanics is an old art, starting a long time ago with building bridges and gothic cathedrals etc. Essence of this art is the understanding of forces, load paths, weight and balance, strength and related deformations. The paper develops a perception of the structural subsystems of telescopes ("tube structure", "alidade") from the viewpoint of structural mechanics as learned from the "bridge builders". Actual example is a proposal for the design of ESO's 42m E-ELT.

  12. BRIDGE: Business Relating to Industry to Develop Gifted Education - A Career Education Project for the Gifted and Talented: Final Report.

    ERIC Educational Resources Information Center

    Yonkers City School District, NY.

    BRIDGE (Business Relating to Industry to Develop Gifted Education) was designed to bridge the gap between business, industry, and education via an internship program that would expose gifted and talented secondary school students to actual experiences which would increase their career awareness and knowledge of career opportunities. In addition,…

  13. Bridging Cultures between Home and School: A Guide for Teachers--With a Special Focus on Immigrant Latino Families.

    ERIC Educational Resources Information Center

    Trumbull, Elise; Rothstein-Fisch, Carrie; Greenfield, Patricia M.; Quiroz, Blanca

    This book focuses on how to meet the challenges of education in a pluralistic society, presenting the Bridging Cultures framework, which is designed for understanding differences and conflicts that arise in situations where school culture is more individualistic than the home value system. Six sections examine: (1) "The Bridging Cultures…

  14. D0 Silicon Upgrade: End Calorimeter Transfer Bridge Modification

    SciTech Connect

    Stredde, H.J.; /Fermilab

    1996-07-10

    During the assembly of major components into the D0 Detector, a transfer bridge was required to move the North-End Calorimeter from the clean room,over the cable bridge and onto the north sidewalk of the assembly hall. This experiment is now at the beginning stages of the next phase, namely the upgrade of this Detector for future physics research. A major piece of this upgrade is the installation of a solenoid magnet into the Central Calorimeter. In order to accomplish this, the South End Calorimeter has to be removed from the detector and the North End Calorimeter must be moved an additional 20-inch from its nominal open position (total 60-inch movement). The South End Calorimeter will be removed from the detector using the equipment designed for its installation. The calorimeter will be staged on the south sidewalk during the installation of the solenoid magnet and the central tracking systems. The North End Calorimeter is moved 60-inch to give more space between calorimeters during magnet, tracker and cable installation work. This movement will allow the calorimeter to remain coupled to the cryo system. However, this movement requires an extension be added to the center beam. This extension will support the rear wheels of the calorimeter and in the case of the end calorimeters, carry the majority of the weight. The extension is to be a modification of the transfer bridge. This modification, basically has T1 steel blocks added to one end and legs to the sidewalk supports at the other. The T1 steel blocks are notched to fit into the center beam porches and are welded to bridge rails. This design is the same as that for the installation bridge (3740.312-ME-273456), including the welds and weld procedures which are identical in both cases. Since load testing is impractical, the critical welds will be non-destructive tested by ultrasonic means. The laboratory, through the FESS Department, has a contract with M.Q.S. Inspection Inc. The results of this testing will be

  15. Statistical consideration and challenges in bridging study of personalized medicine.

    PubMed

    Li, Meijuan

    2015-01-01

    Applications of personalized medicine are becoming increasingly prominent. A well-characterized market-ready companion diagnostic assay (CDx) is often desired for patient enrollment in device-drug pivotal clinical trial(s) so that Food and Drug Administration can ensure that appropriate clinical and analytical validation studies are planned and carried out for CDx. However, such a requirement may be difficult or impractical to accomplish. A clinical trial assay (CTA) instead of CDx may be used for patient enrollment in the clinical trial. A concordance study (or bridging study) will be required to assess the agreement between CDx and CTA in order to bridge the clinical data (e.g. overall survival) from CTA to CDx and to evaluate the drug efficacy in CDx intended use population. In this article, we will discuss statistical challenges in study design and data analysis for bridging study. Particularly, we aimed to provide statistical methods on how to estimate the drug efficacy in CDx intended use population using results from bridging study and CTA-drug pivotal clinical trial.

  16. Heat Loss Due To Thermal Bridges In Buildings

    NASA Astrophysics Data System (ADS)

    Fang, J. B.; tarot, R. A.; Childs, K. W.; Courville, G. E.

    1984-03-01

    Building envelopes often contain numerous highly conductive heat flow paths, called thermal bridges, which are major sources of heat loss and deterioration of building materials due to moisture condensation. Some examples of thermal bridges occurring in office buildings are presented. Infrared thermography was used to identify the locations and magnitudes of thermally defective areas resulting from inadequate construction, design, or substandard workmanship in existing buildings. Due to the large thermal inertia of building components and transient conditions caused by fluctuating outdoor and indoor temperatures, long measurement periods are required. This makes thermography impractical for quantifying the heat loss. In order to estimate the heat loss rate from thermal bridges and to obtain a better understanding of the physical processes involved, a two-dimensional heat flow model has been developed for transient heat conduction within the exterior wall/intermediate floor systems. The calculated results from the mathematical model are compared with available experimental data. An in-situ measurement technique, which is currently under development at NBS for quantifying the energy loss due to thermal bridges, is described.

  17. Dynamic Analysis of Coupled Vehicle-Bridge System with Uniformly Variable Speed

    NASA Astrophysics Data System (ADS)

    Wei-zhen, Li; Chang-ping, Chen; Yi-qi, Mao; Chang-zhao, Qian

    2016-09-01

    In this paper, a planar biaxial vehicle model with four degrees of freedom is presented based on spring-damping-mass system theory. By using Runge-Kutta method, the dynamic characteristics of a simply support bridge acting by moving vehicle with uniform variable speed are analyzed, and the effects of inertia force, relative acceleration and initial velocity are taken into consideration in the present research. The time-deflection response curves of the bridge under the variation of initial speed and acceleration are analyzed. Some valuable results are found which can provide a theoretical direction for the consideration of dynamical characteristics in design of bridge system.

  18. A Conversion of Wheatstone Bridge to Current-Loop Signal Conditioning for Strain Gages

    NASA Technical Reports Server (NTRS)

    Anderson, Karl F.

    1995-01-01

    Current loop circuitry replaced Wheatstone bridge circuitry to signal-condition strain gage transducers in more than 350 data channels for two different test programs at NASA Dryden Flight Research Center. The uncorrected test data from current loop circuitry had a lower noise level than data from comparable Wheatstone bridge circuitry, were linear with respect to gage-resistance change, and were uninfluenced by varying lead-wire resistance. The current loop channels were easier for the technicians to set up, verify, and operate than equivalent Wheatstone bridge channels. Design choices and circuit details are presented in this paper in addition to operational experience.

  19. Instrumentation for durability monitoring of a long-span cable-stayed bridge

    NASA Astrophysics Data System (ADS)

    Hua, X. G.; Ni, Y. Q.; Zhou, H. F.; Ko, J. M.

    2005-05-01

    This paper outlines the design of an instrumentation system for durability monitoring of the world's longest cable-stayed bridge: the Sutong Bridge with a central span of 1088 m. As part of the Structural Health Monitoring And Safety Evaluation System (SHMASES) for the Sutong Bridge, the durability monitoring system is designed to monitor the corrosion in reinforced concrete structures. The sensors for durability monitoring include two categories. The first category refers to the sensors to monitor the causes leading to corrosion, such as temperature and relative humidity. The second category is electrode assemblies which are used to monitor the end results of corrosion. Data from the sensory system are then periodically collected using a portable or remotely computerized data acquisition system. The collected data from this system will provide useful information on maintenance and repair of concrete structures, and are envisaged to be incorporated into the reliability-based safety evaluation system developed for the Sutong Bridge

  20. Rapid electron tunneling through oligophenylenevinylene bridges.

    PubMed

    Sikes, H D; Smalley, J F; Dudek, S P; Cook, A R; Newton, M D; Chidsey, C E; Feldberg, S W

    2001-02-23

    We measured rate constants of thermal, interfacial electron transfer through oligophenylenevinylene bridges between a gold electrode and a tethered redox species in contact with an aqueous electrolyte using the indirect laser-induced temperature jump technique. Analysis of the distance dependence indicates that, unlike other bridges studied to date, the rate constants are not limited by electronic coupling for bridges up to 28 angstroms long. The energy levels of the bridges relative to those of the redox species rule out hopping through the bridge. We conclude that, out to 28 angstroms, the transfer is limited by structural reorganization and that electron tunneling occurs in less than 20 picoseconds, suggesting that oligophenylenevinylene bridges could be useful for wiring molecular electronic elements.

  1. Boundary Stability of a Nematic Liquid Bridge

    NASA Astrophysics Data System (ADS)

    Barnes, William; Santangelo, Chris

    2014-03-01

    We consider a nematic liquid crystal droplet in air confined between two parallel plates with homeotropic boundary conditions. The boundary conditions at the nematic-plate and nematic-air interfaces induce either a hedgehog or planar ring disclination within the nematic bridge, depending on the plate separation and bridge radius. We study the stability of the liquid crystal-air boundary of a nearly cylindrical nematic bridge by minimizing the Frank elastic energy.

  2. Measurement of Deflection Line on Bridges

    NASA Astrophysics Data System (ADS)

    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.

  3. Dynamics and Statics of Nonaxisymmetric Liquid Bridges

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

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

  4. Family Medicine: Bridge to Life.

    PubMed

    Luz, Clare

    2016-01-01

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

  5. 76 FR 55160 - Annual Materials Report on New Bridge Construction and Bridge Rehabilitation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-06

    ... for bridges that were new or replaced within the defined time period. The FHWA's Financial Management Information System and the 2010 NBI were used to identify the material types for bridges that...

  6. Dynamic analysis of a long span, cable-stayed freeway bridge using NASTRAN

    NASA Technical Reports Server (NTRS)

    Salus, W. L.; Jones, R. E.; Ice, M. W.

    1973-01-01

    The dynamic analysis for earthquake- and wind-induced response of a long span, cable-stayed freeway bridge by NASTRAN in conjunction with post-processors is described. Details of the structural modeling, the input data generation, and numerical results are given. The influence of the dynamic analysis on the bridge design is traced from the project initiation to the development of a successful earthquake and wind resistant configuration.

  7. Railway bridge monitoring during construction and sliding

    NASA Astrophysics Data System (ADS)

    Inaudi, Daniele; Casanova, Nicoletta; Kronenberg, Pascal; Vurpillot, Samuel

    1997-05-01

    The Moesa railway bridge is a composite steel concrete bridge on three spans of 30 m each. The 50 cm thick concrete deck is supported on the lower flanges of two continuous, 2.7 m high I-beams. The bridge has been constructed alongside an old metallic bridge. After demolishing this one, the new bridge has been slid for 5 m by 4 hydraulic jacks and positioned on the refurbished piles of the old bridge. About 30 fiber optic, low-coherence sensors were imbedded in the concrete deck to monitor its deformations during concrete setting and shrinkage, as well as during the bridge sliding phase. In the days following concrete pour it was possible to follow its thermal expansion due to the exothermic setting reaction and the following thermal and during shrinkage. The deformations induced by the additional load produced by the successive concreting phases were also observed. During the bridge push, which extended over six hours, the embedded and surface mounted sensors allowed the monitoring of the curvature variations in the horizontal plane due to the slightly uneven progression of the jacks. Excessive curvature and the resulting cracking of concrete could be ruled out by these measurements. It was also possible to observe the bridge elongation under the heating action of the sun.

  8. The breaking of axisymmetric slender liquid bridges

    NASA Astrophysics Data System (ADS)

    Meseguer, J.

    1983-05-01

    Liquids held by surface tension forces can bridge the gap between two solid bodies placed not too far apart from each other. The equilibrium conditions and stability criteria for static, cylindrical liquid bridges are well known. However, the behaviour of an unstable liquid bridge, regarding both its transition toward breaking and the resulting configuration, is a matter for discussion. The dynamical problem of axisymmetric rupture of a long liquid bridge anchored at two equal coaxial disks is treated in this paper through the adoption of one-dimensional theories which are widely used in capillary jet problems.

  9. Design.

    ERIC Educational Resources Information Center

    Online-Offline, 1998

    1998-01-01

    Provides an annotated bibliography of resources on this month's theme "Design" for K-8 language arts, art and architecture, music and dance, science, math, social studies, health, and physical education. Includes Web sites, CD-ROMs and software, videos, books, audiotapes, magazines, professional resources and classroom activities.…

  10. Design

    ERIC Educational Resources Information Center

    Buchanan, Richard; Cross, Nigel; Durling, David; Nelson, Harold; Owen, Charles; Valtonen, Anna; Boling, Elizabeth; Gibbons, Andrew; Visscher-Voerman, Irene

    2013-01-01

    Scholars representing the field of design were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Richard Buchanan, Nigel Cross, David Durling, Harold Nelson, Charles Owen, and Anna Valtonen. Scholars…

  11. 49 CFR 237.103 - Bridge inspection procedures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Bridge inspection procedures. 237.103 Section 237... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.103 Bridge inspection procedures. (a) Each bridge management program shall specify the procedure to be used...

  12. 49 CFR 237.107 - Conduct of bridge inspections.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Conduct of bridge inspections. 237.107 Section 237... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.107 Conduct of bridge inspections. Bridge inspections shall be conducted under the direct supervision of a...

  13. 49 CFR 237.103 - Bridge inspection procedures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Bridge inspection procedures. 237.103 Section 237... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.103 Bridge inspection procedures. (a) Each bridge management program shall specify the procedure to be used...

  14. 49 CFR 237.107 - Conduct of bridge inspections.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Conduct of bridge inspections. 237.107 Section 237... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.107 Conduct of bridge inspections. Bridge inspections shall be conducted under the direct supervision of a...

  15. 49 CFR 237.103 - Bridge inspection procedures.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Bridge inspection procedures. 237.103 Section 237... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.103 Bridge inspection procedures. (a) Each bridge management program shall specify the procedure to be used...

  16. 49 CFR 237.33 - Content of bridge management programs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Content of bridge management programs. 237.33... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Railroad Bridge Safety Assurance § 237.33 Content of bridge management programs. Each bridge management program adopted in compliance with this...

  17. 49 CFR 237.103 - Bridge inspection procedures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Bridge inspection procedures. 237.103 Section 237... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.103 Bridge inspection procedures. (a) Each bridge management program shall specify the procedure to be used...

  18. 49 CFR 237.107 - Conduct of bridge inspections.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Conduct of bridge inspections. 237.107 Section 237... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.107 Conduct of bridge inspections. Bridge inspections shall be conducted under the direct supervision of a...

  19. 49 CFR 237.107 - Conduct of bridge inspections.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Conduct of bridge inspections. 237.107 Section 237... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.107 Conduct of bridge inspections. Bridge inspections shall be conducted under the direct supervision of a...

  20. 33 CFR 118.85 - Lights on vertical lift bridges.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 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...

  1. 9. VIEW OF BRIDGE NEAR CENTER SPAN, LOOKING NORTH FROM ...

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

    9. VIEW OF BRIDGE NEAR CENTER SPAN, LOOKING NORTH FROM THE ARROYO SECO. THE PARKER-MAYBERRY BRIDGE IS BELOW THE COLORADO STREET BRIDGE, THE PIONEER BRIDGE IS IN THE BACKGROUND. - Colorado Street Bridge, Spanning Arroyo Seco at Colorado Boulevard, Pasadena, Los Angeles County, CA

  2. 3. CONTEXTUAL VIEW OF BRIDGE IN SETTING, LOOKING SOUTHWEST FROM ...

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

    3. CONTEXTUAL VIEW OF BRIDGE IN SETTING, LOOKING SOUTHWEST FROM ELEVATED GRADE OF EUREKA SOUTHERN RAILROAD. EUREKA SOUTHERN TRUSS BRIDGE AT EXTREME LEFT, 1924 HIGHWAY BRIDGE IN CENTER, 1952 HIGHWAY BRIDGE AT RIGHT - Van Duzen River Bridge, Spanning Van Duzen River at CA State Highway 101, Alton, Humboldt County, CA

  3. 23 CFR 650.307 - Bridge inspection organization.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... BRIDGES, STRUCTURES, AND HYDRAULICS National Bridge Inspection Standards § 650.307 Bridge inspection... 23 Highways 1 2013-04-01 2013-04-01 false Bridge inspection organization. 650.307 Section 650.307... bridges located on public roads that are fully or partially located within the State's boundaries,...

  4. 23 CFR 650.307 - Bridge inspection organization.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... BRIDGES, STRUCTURES, AND HYDRAULICS National Bridge Inspection Standards § 650.307 Bridge inspection... 23 Highways 1 2012-04-01 2012-04-01 false Bridge inspection organization. 650.307 Section 650.307... bridges located on public roads that are fully or partially located within the State's boundaries,...

  5. 33 CFR 118.85 - Lights on vertical lift bridges.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... below the outermost edge of the bridge span structure so as to be visible from an approaching vessel... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Lights on vertical lift bridges... BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.85 Lights on vertical lift bridges. (a) Lift span...

  6. 33 CFR 118.85 - Lights on vertical lift bridges.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... below the outermost edge of the bridge span structure so as to be visible from an approaching vessel... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Lights on vertical lift bridges... BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.85 Lights on vertical lift bridges. (a) Lift span...

  7. 49 CFR 237.33 - Content of bridge management programs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Content of bridge management programs. 237.33... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Railroad Bridge Safety Assurance § 237.33 Content of bridge management programs. Each bridge management program adopted in compliance with this...

  8. 33 CFR 118.85 - Lights on vertical lift bridges.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... below the outermost edge of the bridge span structure so as to be visible from an approaching vessel... 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...

  9. 49 CFR 237.33 - Content of bridge management programs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Content of bridge management programs. 237.33... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Railroad Bridge Safety Assurance § 237.33 Content of bridge management programs. Each bridge management program adopted in compliance with this...

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

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  11. 23 CFR 650.807 - Bridges requiring a USCG permit.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.807 Bridges requiring a USCG... 23 Highways 1 2012-04-01 2012-04-01 false Bridges requiring a USCG permit. 650.807 Section 650.807... improvement or construction of a bridge over navigable waters except for the exemption exercised by FHWA...

  12. 23 CFR 650.307 - Bridge inspection organization.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... BRIDGES, STRUCTURES, AND HYDRAULICS National Bridge Inspection Standards § 650.307 Bridge inspection... 23 Highways 1 2011-04-01 2011-04-01 false Bridge inspection organization. 650.307 Section 650.307... bridges located on public roads that are fully or partially located within the State's boundaries,...

  13. 23 CFR 650.307 - Bridge inspection organization.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... BRIDGES, STRUCTURES, AND HYDRAULICS National Bridge Inspection Standards § 650.307 Bridge inspection... 23 Highways 1 2010-04-01 2010-04-01 false Bridge inspection organization. 650.307 Section 650.307... bridges located on public roads that are fully or partially located within the State's boundaries,...

  14. 49 CFR 237.33 - Content of bridge management programs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Content of bridge management programs. 237.33... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Railroad Bridge Safety Assurance § 237.33 Content of bridge management programs. Each bridge management program adopted in compliance with this...

  15. 23 CFR 650.307 - Bridge inspection organization.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... BRIDGES, STRUCTURES, AND HYDRAULICS National Bridge Inspection Standards § 650.307 Bridge inspection... 23 Highways 1 2014-04-01 2014-04-01 false Bridge inspection organization. 650.307 Section 650.307... bridges located on public roads that are fully or partially located within the State's boundaries,...

  16. 33 CFR 118.70 - Lights on swing bridges.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Lights on swing bridges. 118.70 Section 118.70 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.70 Lights on swing bridges. (a) Swing span lights on through bridges....

  17. 23 CFR 650.807 - Bridges requiring a USCG permit.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.807 Bridges requiring a USCG... 23 Highways 1 2014-04-01 2014-04-01 false Bridges requiring a USCG permit. 650.807 Section 650.807... improvement or construction of a bridge over navigable waters except for the exemption exercised by FHWA...

  18. 33 CFR 115.50 - Application for bridge permits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Application for bridge permits... BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.50 Application for bridge permits. (a) Approval of plans. An application for authorization to construct a bridge across navigable...

  19. 33 CFR 115.50 - Application for bridge permits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Application for bridge permits... BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.50 Application for bridge permits. (a) Application. An application for authorization to construct a bridge across navigable waters...

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

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Content of bridge management programs. 237.33... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Railroad Bridge Safety Assurance § 237.33 Content of bridge management programs. Each bridge management program adopted in compliance with this...

  1. 33 CFR 115.50 - Application for bridge permits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Application for bridge permits... BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.50 Application for bridge permits. (a) Application. An application for authorization to construct a bridge across navigable waters...

  2. 33 CFR 118.70 - Lights on swing bridges.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Lights on swing bridges. 118.70 Section 118.70 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.70 Lights on swing bridges. (a) Swing span lights on through bridges....

  3. 23 CFR 650.807 - Bridges requiring a USCG permit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.807 Bridges requiring a USCG... 23 Highways 1 2011-04-01 2011-04-01 false Bridges requiring a USCG permit. 650.807 Section 650.807... improvement or construction of a bridge over navigable waters except for the exemption exercised by FHWA...

  4. 23 CFR 650.807 - Bridges requiring a USCG permit.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.807 Bridges requiring a USCG... 23 Highways 1 2013-04-01 2013-04-01 false Bridges requiring a USCG permit. 650.807 Section 650.807... improvement or construction of a bridge over navigable waters except for the exemption exercised by FHWA...

  5. 33 CFR 115.50 - Application for bridge permits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Application for bridge permits... BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.50 Application for bridge permits. (a) Application. An application for authorization to construct a bridge across navigable waters...

  6. 33 CFR 118.70 - Lights on swing bridges.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Lights on swing bridges. 118.70 Section 118.70 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.70 Lights on swing bridges. (a) Swing span lights on through bridges....

  7. 33 CFR 118.90 - Bridges crossing channel obliquely.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bridges crossing channel... SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.90 Bridges crossing channel obliquely. Bridges crossing a body of water at an angle other than 90° with the axis of the channel shall be lighted...

  8. 33 CFR 118.90 - Bridges crossing channel obliquely.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Bridges crossing channel... SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.90 Bridges crossing channel obliquely. Bridges crossing a body of water at an angle other than 90° with the axis of the channel shall be lighted...

  9. 49 CFR 237.101 - Scheduling of bridge inspections.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 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...

  10. 49 CFR 237.101 - Scheduling of bridge inspections.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Scheduling of bridge inspections. 237.101 Section... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.101 Scheduling of bridge inspections. (a) Each bridge management program shall include a provision for scheduling...

  11. 49 CFR 237.101 - Scheduling of bridge inspections.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 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...

  12. 49 CFR 237.101 - Scheduling of bridge inspections.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 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...

  13. 49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Movable bridge, interlocking of signal appliances with bridge devices. 236.312 Section 236.312 Transportation Other Regulations Relating to... SYSTEMS, DEVICES, AND APPLIANCES Interlocking Standards § 236.312 Movable bridge, interlocking of...

  14. 49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Movable bridge, interlocking of signal appliances with bridge devices. 236.312 Section 236.312 Transportation Other Regulations Relating to... SYSTEMS, DEVICES, AND APPLIANCES Interlocking Standards § 236.312 Movable bridge, interlocking of...

  15. 6. VIEW OF GDOT BRIDGE NO. 02700268X00678N BRIDGE PLATE IDENTIFYING ...

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

    6. VIEW OF GDOT BRIDGE NO. 027-00268X-00678N BRIDGE PLATE IDENTIFYING COUNTY COMMISSIONERS AT THE TIME OF CONSTRUCTION. - GDOT Bridge No. 027-00268X-00678N, County Road 268-Empress Road span Piscola Creek, Quitman, Brooks County, GA

  16. 75 FR 62181 - Annual Materials Report on New Bridge Construction and Bridge Rehabilitation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-07

    ... Rehabilitation AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Notice. SUMMARY: Section 1114 of the... materials used in new Federal-aid bridge construction and bridge rehabilitation projects. As part of the... rehabilitation projects. Data on Federal-aid and non-Federal-aid highway bridges are included in the report...

  17. Global monitoring concept for bridges

    NASA Astrophysics Data System (ADS)

    Bergmeister, Konrad; Santa, Ulrich

    2000-06-01

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

  18. Operation IceBridge Alaska

    NASA Astrophysics Data System (ADS)

    Larsen, C.

    2015-12-01

    The University of Alaska Fairbanks (UAF) has flown LiDAR missions for Operation IceBridge in Alaska each year since 2009, expanding upon UAF's airborne laser altimetry program which started in 1994. These observations show that Alaska's regional mass balance is -75+11/-16 Gt yr-1 (1994-2013) (Larsen et al., 2015). A surprising result is that the rate of surface mass loss observed on non-tidewater glaciers in Alaska is extremely high. At these rates, Alaska contributes ~1 mm to global sea level rise every 5 years. Given the present lack of adequate satellite resources, Operation IceBridge airborne surveys by UAF are the most effective and efficient method to monitor this region's impact on global sea level rise. Ice depth measurements using radar sounding have been part of these airborne surveys since 2012. Many of Alaska's tidewater glaciers are bedded significantly below sea level. The depth and extent of glacier beds below sea level are critical factors in the dynamics of tidewater retreat. Improved radar processing tools are being used to predict clutter using forward simulation. This is essential to properly sort out true bed returns, which are often masked or obscured by valley wall returns. This presentation will provide an overview of the program, highlighting recent findings and observations from the most recent campaigns, and focusing on techniques used for the extrapolation of surface elevation changes to regional mass balances.

  19. Bridges to sustainable tropical health

    PubMed Central

    Singer, Burton H.; de Castro, Marcia Caldas

    2007-01-01

    Ensuring sustainable health in the tropics will require bridge building between communities that currently have a limited track record of interaction. It will also require new organizational innovation if much of the negative health consequences of large-scale economic development projects are to be equitably mitigated, if not prevented. We focus attention on three specific contexts: (i) forging linkages between the engineering and health communities to implement clean water and sanitation on a broad scale to prevent reworming, after the current deworming-only programs, of people by diverse intestinal parasites; (ii) building integrated human and animal disease surveillance infrastructure and technical capacity in tropical countries on the reporting and scientific evidence requirements of the sanitary and phytosanitary agreement under the World Trade Organization; and (iii) developing an independent and equitable organizational structure for health impact assessments as well as monitoring and mitigation of health consequences of economic development projects. Effective global disease surveillance and timely early warning of new outbreaks will require a far closer integration of veterinary and human medicine than heretofore. Many of the necessary surveillance components exist within separate animal- and human-oriented organizations. The challenge is to build the necessary bridges between them. PMID:17913894

  20. A novel bridge scour monitoring and prediction system

    NASA Astrophysics Data System (ADS)

    Valyrakis, Manousos; Michalis, Panagiotis; Zhang, Hanqing

    2015-04-01

    obtaining real time data, via novel electromagnetic sensors monitoring scour depth. Once the model is trained with data representative of the new system, bridge scour prediction can be performed for high/design flows or floods.

  1. Flood Control Minnesota River, Minnesota, Mankato-North Mankato-Le Hillier. Design Memorandum Number 8. Part I. Location Study and Draft Supplement II to the Final Environmental Impact Statement for Bridge Relocations. Main Street, Trunk Highways 60 Bridge over the Minnesota River between Mankato and North Mankato.

    DTIC Science & Technology

    1981-06-01

    Company. e. Design Memorandum No. 1 through 7, Flood Control Minnesota River, Minnesota, Mankato-North Mankato-Le Hillier. f. Final Enviromental ... Printing , and some vacant urban renewal parcels. Although part of the renewal area, development in this area has halted pending the outcome of the...prepared as Technical Report No. 7, "Archaeological Resources" printed under separate cover as an appendix to the final supplement to the EIS. Utilities

  2. Analysis of longitudinal seismic response of bridge with magneto-rheological elastomeric bearings

    NASA Astrophysics Data System (ADS)

    Li, Rui; Li, Xi; Wu, Yueyuan; Chen, Shiwei; Wang, Xiaojie

    2016-04-01

    As the weakest part in the bridge system, traditional bridge bearing is incapable of isolating the impact load such as earthquake. A magneto-rheological elastomeric bearing (MRB) with adjustable stiffness and damping parameters is designed, tested and modeled. The developed Bouc-Wen model is adopted to represent the constitutive relation and force-displacement behavior of an MRB. Then, the lead rubber bearing (LRB), passive MRB and controllable MRB are modeled by finite element method (FEM). Furthermore, two typical seismic waves are adopted as inputs for the isolation system of bridge seismic response. The experiments are carried out to investigate the different response along the bridge with on-off controlled MRBs. The results show that the isolating performance of MRB is similar to that of traditional LRB, which ensures the fail-safe capability of bridge with MRBs under seismic excitation. In addition, the controllable bridge with MRBs demonstrated the advantage of isolating capacity and energy dissipation, because it restrains the acceleration peak of bridge beam by 33.3%, and the displacement of bearing decrease by 34.1%. The shear force of the pier top is also alleviated.

  3. Thermal correlation analysis of a long-span suspension bridge static responses

    NASA Astrophysics Data System (ADS)

    Zhou, Linren; Chen, Lan; Xia, Yong; Brownjohn, James M. W.

    2016-04-01

    Harsh service environment degenerates the performance of bridges even leads to catastrophic collapse. Structural temperature has been widely recognized as one of the most negative environmental effects on bridges. The structural responses are deeply affected by the variation and distribution of temperatures on bridges. Therefore, identifying the correlations between them is a significant issue for structural safety assessment. In this study, the relationships between the temperature induced static response and the surrounding weather factors are investigated based on the long-term field measurements of a long-span suspension bridge. The correlations of the meteorological parameters between the bridge filed and the nearby weather station, and the relations of structural static responses to the air temperature, are investigated. The results indicate that relationships of meteorological parameters between nearby weather station and the bridge field can be predicted. The correlation between the static responses and the air temperature and is remarkable with high correlation coefficient. The conclusions are expected to provide reference for the design and evaluation of longspan suspension bridges.

  4. Initial testing of advanced ground-penetrating radar technology for the inspection of bridge decks: the HERMES and PERES Bridge Inspectors

    NASA Astrophysics Data System (ADS)

    Davidson, Nigel C.; Chase, Steven B.

    1999-02-01

    Since early 1995 the Federal Highway Administration (FHWA) has been sponsoring the development of ground-penetrating radar technology to produce a tool for the non-destructive evaluation of bridge decks. Under contract with the FHWA, Lawrence Livermore National Laboratory designed and built a system capable of recording data over a 2 meter width during normal traffic flow. The derived system is called `The HERMES Bridge Inspector' (High-speed Electromagnetic Roadway Measurement and Evaluation System) and includes a 64 channel antenna array within a 30 ft trailer. For detailed investigation of portions of a bridge deck, a robotic cart mounted radar has been developed. This cart system is named `The PERES Bridge Inspector' (Precision Electromagnetic Roadway Evaluation System). PERES records data over the chosen area by rastering a single transceiver over the road. Images of the deck interior are reconstructed from the original synthetic aperture data using diffraction tomography. The work presented herein describes the findings of initial experiments conducted to determine the inspection capabilities of these systems. Internal defects such as delaminations, voids and disbonds; and construction details including deck thickness, asphalt overlay thickness and reinforcement layout were the features targeted. The final goal is for these systems, and other non-destructive technologies, to provide information on the condition of the nation's bridges for input to bridge management systems.

  5. Plans for a sensitivity analysis of bridge-scour computations

    USGS Publications Warehouse

    Dunn, David D.; Smith, Peter N.

    1993-01-01

    Plans for an analysis of the sensitivity of Level 2 bridge-scour computations are described. Cross-section data from 15 bridge sites in Texas are modified to reflect four levels of field effort ranging from no field surveys to complete surveys. Data from United States Geological Survey (USGS) topographic maps will be used to supplement incomplete field surveys. The cross sections are used to compute the water-surface profile through each bridge for several T-year recurrence-interval design discharges. The effect of determining the downstream energy grade-line slope from topographic maps is investigated by systematically varying the starting slope of each profile. The water-surface profile analyses are then used to compute potential scour resulting from each of the design discharges. The planned results will be presented in the form of exceedance-probability versus scour-depth plots with the maximum and minimum scour depths at each T-year discharge presented as error bars.

  6. Seismic fragility analysis of typical pre-1990 bridges due to near- and far-field ground motions

    NASA Astrophysics Data System (ADS)

    Mosleh, Araliya; Razzaghi, Mehran S.; Jara, José; Varum, Humberto

    2016-03-01

    Bridge damages during the past earthquakes caused several physical and economic impacts to transportation systems. Many of the existing bridges in earthquake prone areas are pre-1990 bridges and were designed with out of date regulation codes. The occurrences of strong motions in different parts of the world show every year the vulnerability of these structures. Nonlinear dynamic time history analyses were conducted to assess the seismic vulnerability of typical pre-1990 bridges. A family of existing concrete bridge representative of the most common bridges in the highway system in Iran is studied. The seismic demand consists in a set of far-field and near-field strong motions to evaluate the likelihood of exceeding the seismic capacity of the mentioned bridges. The peak ground accelerations (PGAs) were scaled and applied incrementally to the 3D models to evaluate the seismic performance of the bridges. The superstructure was assumed to remain elastic and the nonlinear behavior in piers was modeled by assigning plastic hinges in columns. In this study the displacement ductility and the PGA are selected as a seismic performance indicator and intensity measure, respectively. The results show that pre-1990 bridges subjected to near-fault ground motions reach minor and moderate damage states.

  7. Bridge assessment based on statistical analysis of the response of a vehicle passing over the bridge

    NASA Astrophysics Data System (ADS)

    Yamamoto, Kyosuke; Toshinami, Tatsuaki; Oshima, Yoshinobu; Kim, Chul-Woo; Sugiura, Kunitomo; Kawatani, Mitsuo

    This study focuses on the vehicle acceleration response as a source of estimating bridge's health condition, since it contains bridge profile information and a change of the bridge profile caused by bridge damage can be detected from change of statistical vehicle response. The wavelet coefficient is used as a damage index. To increase the possibility of detecting the damage, the kurtosis of the index is adopted. By observation from a laboratory experiment, it is found that kurtosis of vehicle response is a sensitive index for bridge damage.

  8. Bridges to Healthy Communities. AACC Project Brief.

    ERIC Educational Resources Information Center

    Ottenritter, Nan; Barnett, Lynn

    The Bridges to Healthy Communities project assists community colleges in offering education and information services that help prevent HIV infection and other serious health problems in students. The five-year Bridges project emphasizes service learning as a community-building and intervention strategy for preventing HIV infection. This initiative…

  9. Students' Conceptions of Mathematics Bridging Courses

    ERIC Educational Resources Information Center

    Gordon, Sue; Nicholas, Jackie

    2013-01-01

    In this study we investigate the conceptions of mathematics bridging courses held by students enrolled in these courses at a major Australian university. We report on the participants' responses to email-interview questions about the mathematics bridging courses to describe a two-dimensional outcome space of variations in awareness about the…

  10. 9. View of bridge looking west. A fundraising marathon is ...

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

    9. View of bridge looking west. A fund-raising marathon is in prgress. The traffic levels outside the main arch were added in 1965 when the bridge underwent extensive rehabilitation. - Detroit Superior High Level Bridge, Cleveland, Cuyahoga County, OH

  11. 29. Historic photographer, photographer unknown, c. 1944. VIEW OF BRIDGE, ...

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

    29. Historic photographer, photographer unknown, c. 1944. VIEW OF BRIDGE, LOOKING EAST FROM TOP OF WEST TOWER. SHEEP CROSSING BRIDGE. NOTE SWAY CABLES. - Verde River Sheep Bridge, Spanning Verde River (Tonto National Forest), Cave Creek, Maricopa County, AZ

  12. 1. AERIAL VIEW LOOKING SOUTHWEST (OLD HARVARD STREET BRIDGE AT ...

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

    1. AERIAL VIEW LOOKING SOUTHWEST (OLD HARVARD STREET BRIDGE AT LEFT, NEW BRIDGE AT RIGHT) - Old Harvard Street Bridge, Spanning Rock Creek at National Zoological Park, Washington, District of Columbia, DC

  13. 5. View showing Crooked River High Bridge in background and ...

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

    5. View showing Crooked River High Bridge in background and Ralph Modjeski railroad bridge in foreground - Crooked River High Bridge, Spanning Crooked River Gorge at Dalles-California Highway, Terrebonne, Deschutes County, OR

  14. 1. AERIAL VIEW OF THE PATH TRANSIT SYSTEM BRIDGE, LOOKING ...

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

    1. AERIAL VIEW OF THE PATH TRANSIT SYSTEM BRIDGE, LOOKING NORTHEAST. THE CONRAIL BRIDGE (HAER No. NJ-43) AND THE NEWARK TURNPIKE ARE VISIBLE IN THE BACKGROUND - Path Transit System Bridge, Spanning Hackensack River, Kearny, Hudson County, NJ

  15. 1. OVERALL VIEW OF BRIDGE AND LINCOLN HIGHWAY, SHOWING NORTH ...

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

    1. OVERALL VIEW OF BRIDGE AND LINCOLN HIGHWAY, SHOWING NORTH APPROACH TO BRIDGE. VIEW TO SOUTH. - Rock Valley Bridge, Spanning North Timber Creek at Old U.S. Highway 30, Marshalltown, Marshall County, IA

  16. 19. COPY OF ENGRAVING OF 'WROUGHT IRON ARCH TRUSS BRIDGE,' ...

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

    19. COPY OF ENGRAVING OF 'WROUGHT IRON ARCH TRUSS BRIDGE,' PAT. DEC. 10, 1867 BY OHIO BRIDGE COMPANY, CLEVELAND, OHIO. (COURTESY OF OHIO HISTORICAL SOCIETY ARCHIVES, COLUMBUS, OHIO) - Tioronda Bridge, South Avenue spanning Fishkill Creek, Beacon, Dutchess County, NY

  17. 1. ARROYO SECO PARKWAY SOUTHBOUND LANES AND PASADENA AVENUE BRIDGE. ...

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

    1. ARROYO SECO PARKWAY SOUTHBOUND LANES AND PASADENA AVENUE BRIDGE. RAILROAD BRIDGE IN DISTANCE. LOOKING 238°WSW. - Arroyo Seco Parkway, Pasadena Avenue Bridge, Milepost 26.48, Los Angeles, Los Angeles County, CA

  18. 5. VIEW OF BRIDGE, LOOKING EAST FROM THE ARROYO SECO. ...

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

    5. VIEW OF BRIDGE, LOOKING EAST FROM THE ARROYO SECO. THE PARKER-MAYBERRY BRIDGE IS IN THE RIGHT FOREGROUND. - Colorado Street Bridge, Spanning Arroyo Seco at Colorado Boulevard, Pasadena, Los Angeles County, CA

  19. Elevation, west portal. Sign on portal reads Watson Mill Bridge, ...

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

    Elevation, west portal. Sign on portal reads Watson Mill Bridge, est. 1885. - Watson Mill Bridge, Spanning South Fork Broad River, Watson Mill Road, Watson Mill Bridge State Park, Comer, Madison County, GA

  20. 2. Contextual view of bridge in setting, from northwest end ...

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

    2. Contextual view of bridge in setting, from northwest end of bridge, view to south-southeast with Rawson Road in foreground. - Red Bank Creek Bridge, Spanning Red Bank Creek at Rawson Road, Red Bluff, Tehama County, CA

  1. 1. Elevation view of bridge to Smokemont Campground. Great ...

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

    1. Elevation view of bridge to Smokemont Campground. - Great Smoky Mountains National Park Roads & Bridges, Smokemont Bridge, Spanning Oconaluftee River at entrance to Smokemont Campground, Gatlinburg, Sevier County, TN

  2. 2. Deck view of bridge to Smokemont Campground. Great ...

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

    2. Deck view of bridge to Smokemont Campground. - Great Smoky Mountains National Park Roads & Bridges, Smokemont Bridge, Spanning Oconaluftee River at entrance to Smokemont Campground, Gatlinburg, Sevier County, TN

  3. 12. Interior detail of bridge operator's house showing generator and ...

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

    12. Interior detail of bridge operator's house showing generator and bridge operator, Mr. Gene Amonette, facing west. - Palm Valley Bridge, County Road 210 spanning Intracoastal Waterway, Ponte Vedra Beach, St. Johns County, FL

  4. 65. HAMILTON APPROACH LOOKING TOWARD BRIDGE, SHOWING TRANSFER OF THE ...

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

    65. HAMILTON APPROACH LOOKING TOWARD BRIDGE, SHOWING TRANSFER OF THE HIGHWAY APPROACH TO THE BRIDGE STRUCTURE. PHOTOGRAPHER: ROBERT A. RYAN - Keokuk & Hamilton Bridge, Spanning Mississippi River, Keokuk, Lee County, IA

  5. 25. REPRESENTATIVE DETAIL VIEW OF THE TWO ARCHED PEDESTRIAN BRIDGES ...

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

    25. REPRESENTATIVE DETAIL VIEW OF THE TWO ARCHED PEDESTRIAN BRIDGES OVER THE CANALS, SHOWING PLANKS AND RAILS. THIS BRIDGE IS THE LINNIE CANAL COURT BRIDGE OVER EASTERN CANAL. - Venice Canals, Community of Venice, Los Angeles, Los Angeles County, CA

  6. 12. PLANK BRIDGE ON OLD ROAD NEAR NORTH FORK VIRGIN ...

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

    12. PLANK BRIDGE ON OLD ROAD NEAR NORTH FORK VIRGIN RIVER BRIDGE, FACING EAST - Zion-Mount Carmel Highway, Virgin River Bridge, Spanning North Fork of Virgin River on Zion-Mount Carmel Highway, Springdale, Washington County, UT

  7. 11. Standing on westerly fender at edge of bridge looking ...

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

    11. Standing on westerly fender at edge of bridge looking easterly, showing horizontal beams for deck and cross beams (reflection of steel grating on deck). Also shows bridge guardrail. - Colusa Bridge, Spanning Sacramento River, Colusa, Colusa County, CA

  8. 27. View of underside of ninth bridge, showing concrete mixture, ...

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

    27. View of underside of ninth bridge, showing concrete mixture, view to the NW. - Vicksburg National Military Park Roads & Bridges, Melan Arch Bridges, Spanning various tributaries at Confederate Avenue, Vicksburg, Warren County, MS

  9. 10. Detail of bridge underside showing gears for locking mechanism ...

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

    10. Detail of bridge underside showing gears for locking mechanism at south end of bridge. View to east. - Locke Avenue Bridge, Locke Avenue (County Route 671) Spanning Raccoon Creek, Swedesboro, Gloucester County, NJ

  10. 28. Photocopy of drawing, Draw for L Street Bridge, Sheet ...

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

    28. Photocopy of drawing, Draw for L Street Bridge, Sheet 6: Girder C, July 1892. City of Boston Public Works Department Bridge files. - Summer Street Bridge, Spanning Reserved Channel, Boston, Suffolk County, MA

  11. 26. Photocopy of drawing, Draw for L Street Bridge, Sheet ...

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

    26. Photocopy of drawing, Draw for L Street Bridge, Sheet 4: Girder D, Girder F, July 1892. City of Boston Public Works Department Bridge files. - Summer Street Bridge, Spanning Reserved Channel, Boston, Suffolk County, MA

  12. 29. Photocopy of drawing, Draw for L Street Bridge, Sheet ...

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

    29. Photocopy of drawing, Draw for L Street Bridge, Sheet 7: Girder D, July 1892. City of Boston Public Works Department Bridge files. - Summer Street Bridge, Spanning Reserved Channel, Boston, Suffolk County, MA

  13. 31. Photocopy of drawing, Draws for L Street Bridge, Main ...

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

    31. Photocopy of drawing, Draws for L Street Bridge, Main Trucks, August 1892. City of Boston Public Works Department Bridge files. - Summer Street Bridge, Spanning Reserved Channel, Boston, Suffolk County, MA

  14. 25. Photocopy of drawing, Draw for L Street Bridge, Sheet ...

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

    25. Photocopy of drawing, Draw for L Street Bridge, Sheet 3: Girder A, July 1892. City of Boston Public Works Department Bridge files. - Summer Street Bridge, Spanning Reserved Channel, Boston, Suffolk County, MA

  15. 23. Photocopy of drawing, Draw for L Street Bridge, Sheet ...

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

    23. Photocopy of drawing, Draw for L Street Bridge, Sheet 1: Plan and Elevation, July 1892. City of Boston Public Works Department Bridge files. - Summer Street Bridge, Spanning Reserved Channel, Boston, Suffolk County, MA

  16. 30. Photocopy of drawing, Draw for L Street Bridge, Sheet ...

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

    30. Photocopy of drawing, Draw for L Street Bridge, Sheet 8: Samson Posts, Truck Rockers, Portal Struts, July 1892. City of Boston Public Works Department Bridge files. - Summer Street Bridge, Spanning Reserved Channel, Boston, Suffolk County, MA

  17. 24. Photocopy of drawing, Draw for L Street Bridge, Sheet ...

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

    24. Photocopy of drawing, Draw for L Street Bridge, Sheet 2: Floor Beams, July 1982. City of Boston Public Works Department Bridge files. - Summer Street Bridge, Spanning Reserved Channel, Boston, Suffolk County, MA

  18. 27. Photocopy of drawing, Draw for L Street Bridge, Sheet ...

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

    27. Photocopy of drawing, Draw for L Street Bridge, Sheet 5: Girder E, July 1892. City of Boston Public Works Department Bridge files. - Summer Street Bridge, Spanning Reserved Channel, Boston, Suffolk County, MA

  19. 2. Long view east, with bridge in foreground, showing length ...

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

    2. Long view east, with bridge in foreground, showing length of Carquinez Strait with Benecia Martinez Bridge in background. - Carquinez Bridge, Spanning Carquinez Strait at Interstate 80, Vallejo, Solano County, CA

  20. 1. VIEW NORTHWEST, THROUGH CENTER SPAN OF EASTBOUND BRIDGE, WESTBOUND ...

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

    1. VIEW NORTHWEST, THROUGH CENTER SPAN OF EASTBOUND BRIDGE, WESTBOUND BRIDGE IN BACKGROUND - Willow Run Expressway Bridge No. R01, Spanning Conrail Railway, eastbound, at US-10, Ypsilanti, Washtenaw County, MI

  1. 6. EARLY MORNING VIEW OF BOTH JOSO HIGH BRIDGE (UNION ...

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

    6. EARLY MORNING VIEW OF BOTH JOSO HIGH BRIDGE (UNION PACIFIC RAILROAD) IN BACKGROUND AND LYONS FERRY BRIDGE IN THE FOREGROUND - Snake River Bridge at Lyons' Ferry, State Route 261 spanning Snake River, Starbuck, Columbia County, WA

  2. 8. OVERALL VIEW OF EAST SIDE OF BRIDGE FROM SOUTHEAST ...

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

    8. OVERALL VIEW OF EAST SIDE OF BRIDGE FROM SOUTHEAST LOOKING NORTHWEST. LOW TIDE REVEALS FOUNDATIONS OF BRIDGE. - Ducktrap Bridge, Spanning Ducktrap River at U.S. Route 1, Lincolnville, Waldo County, ME

  3. 2. VIEW EAST, GENERAL VIEW OF BRIDGE WITHIN SETTING, APPROACH ...

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

    2. VIEW EAST, GENERAL VIEW OF BRIDGE WITHIN SETTING, APPROACH SPANS ON RIGHT, PEDESTRIAN BRIDGE FOR HIKING TRAIL ON LEFT - Bridge No. 1132, Route 80, spanning Hammonasset River, Madison, New Haven County, CT

  4. 1. View of Clark Fork Vehicle Bridge facing west. Panorama ...

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

    1. View of Clark Fork Vehicle Bridge facing west. Panorama showing the entire span of bridge from north shore of the Clark Fork River. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

  5. 1. Elkmont vehicle bridge at Elkmont Campground, galvanized corrugated arch. ...

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

    1. Elkmont vehicle bridge at Elkmont Campground, galvanized corrugated arch. - Great Smoky Mountains National Park Roads & Bridges, Elkmont Vehicle Bridge, Spanning Little River at Elkmont Campground, Gatlinburg, Sevier County, TN

  6. 8. West side of north end of bridge resting on ...

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

    8. West side of north end of bridge resting on approach abutment. Oblique detail view northeast (from below roadbed level, beside bridge). 150 mm lens. - Gault Bridge, Spanning Deer Creek at South Pine Street, Nevada City, Nevada County, CA

  7. Active member bridge feedback control for damping augmentation

    NASA Technical Reports Server (NTRS)

    Chen, Gun-Shing; Lurie, Boris J.

    1992-01-01

    An active damping augmentation approach using active members in a structural system is described. The problem of maximizing the vibration damping in a lightly damped structural system is considered using the analogy of impedance matching between the load and source impedances in an electrical network. The proposed active damping augmentation approach therefore consists of finding the desired active member impedances that maximize the vibration damping, and designing a feedback control in order to achieve desired active member impedances. This study uses a bridge feedback concept that feeds back a combination of signals from sensors of the axial force and relative velocity across the active member to realize the desired active member impedance. The proposed active damping augmentation approach and bridge feedback concept were demonstrated on a three-longeron softly suspended truss structure.

  8. Lighting in Architectural Design.

    ERIC Educational Resources Information Center

    Phillips, Derek

    The primary function of this book is to treat the topic of lighting design in such a manner as to bridge the gap between architects and illuminating engineers. The work is divided into three parts: Part I, Principles of Design, offers information and analysis of how natural and artificial lighting affects building design, how illumination levels…

  9. An update on resin-bonded bridges.

    PubMed

    Barber, M W; Preston, A J

    2008-03-01

    Since the introduction of the 'Rochette' bridge in the 1970s the resin-bonded bridge has undergone a number of developments to become a commonly used technique for replacement of a missing tooth, especially in a minimally restored dentition. One of the major advantages of the resin-bonded bridge is that it requires less tooth preparation than conventional bridgework, with some authorities advising no preparation at all. Some reports have suggested poor long-term success rates, however, if used in appropriate clinical situations, this treatment modality can be extremely successful. The aim of this paper is to review the literature relating to resin-bonded bridges and suggest recommendations for clinicalpractice concerning the provision of resin-bonded bridges.

  10. Hydraulic analysis of the Schoharie Creek bridge

    USGS Publications Warehouse

    Froehlich, David C.; Trent, Roy E.

    1989-01-01

    Ten people died on April 5, 1987 as a result of the collapse of two spans of a New York State Thruway bridge into the floodwaters of Schoharie Creek. The cause of the bridge failure was determined to be scour of bed material from under the foundations of piers supporting the bridge. To evaluate the hydraulic conditions that produced the scour, a two-dimensional finite element surface-water flow model was constructed. The model was used to obtain a detailed description of water-surface elevations and depth-averaged velocities within a reach that extends from about 4000 ft downstream of the bridge to about 6000 ft upstream of the bridge.

  11. Modeling walker synchronization on the Millennium Bridge.

    PubMed

    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. Modeling walker synchronization on the Millennium Bridge

    NASA Astrophysics Data System (ADS)

    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.

  13. Seismic response of steel suspension bridge

    SciTech Connect

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

    1996-11-01

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

  14. 4. VIEW SHOWING TWO SPANS NEAR CENTER OF BRIDGE, LOOKING ...

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

    4. VIEW SHOWING TWO SPANS NEAR CENTER OF BRIDGE, LOOKING NORTH. THE SMALLER PARKER-MAYBERRY BRIDGE CAN BE SEEN BELOW THE MAIN BRIDGE, AND THE NEW PIONEER BRIDGE IS IN THE BACKGROUND. THE ARROYO CHANNEL, CONSTRUCTED BY THE WORKS PROGRESS ADMINISTRATION DURING THE 1930s, IS VISIBLE ALONG THE ARROYO SECO BELOW THE PARKER-MAYBERRY BRIDGE. - Colorado Street Bridge, Spanning Arroyo Seco at Colorado Boulevard, Pasadena, Los Angeles County, CA

  15. Stability of axisymmetric liquid bridges

    NASA Astrophysics Data System (ADS)

    Fel, Leonid G.; Rubinstein, Boris Y.

    2015-12-01

    Based on the Weierstrass representation of second variation, we develop a non-spectral theory of stability for isoperimetric problem with minimized and constrained two-dimensional functionals of general type and free endpoints allowed to move along two given planar curves. We establish the stability criterion and apply this theory to the axisymmetric liquid bridge between two axisymmetric solid bodies without gravity to determine the stability of menisci with free contact lines. For catenoid and cylinder menisci and different solid shapes, we determine the stability domain. The other menisci (unduloid, nodoid and sphere) are considered in a simple setup between two plates. We find the existence conditions of stable unduloid menisci with and without inflection points.

  16. Bridging the Health Data Divide

    PubMed Central

    2016-01-01

    Fundamental quality, safety, and cost problems have not been resolved by the increasing digitization of health care. This digitization has progressed alongside the presence of a persistent divide between clinicians, the domain experts, and the technical experts, such as data scientists. The disconnect between clinicians and data scientists translates into a waste of research and health care resources, slow uptake of innovations, and poorer outcomes than are desirable and achievable. The divide can be narrowed by creating a culture of collaboration between these two disciplines, exemplified by events such as datathons. However, in order to more fully and meaningfully bridge the divide, the infrastructure of medical education, publication, and funding processes must evolve to support and enhance a learning health care system. PMID:27998877

  17. Local-based damage detection of cyclically loaded bridge piers using wireless sensing units

    NASA Astrophysics Data System (ADS)

    Hou, Tsung-Chin; Lynch, Jerome P.; Parra-Montesinos, Gustavo

    2005-05-01

    Concrete bridge piers are a common structural element employed in the design of bridges and elevated roadways. In order to ensure adequate behavior under earthquake-induced displacements, extensive reinforcement detailing in the form of closely spaced ties or spirals is necessary, leading to congestion problems and difficulties during concrete casting. Further, costly repairs are often necessary in bridge piers after a major earthquake which in some cases involve the total or partial shutdown of the bridge. In order to increase the damage tolerance while relaxing the transverse reinforcement requirements of bridge piers, the use of high-performance fiber reinforced cementitious composites (HPFRCC) in earthquake-resistant bridge piers is explored. HPFRCCs are a relatively new class of cementitious material for civil structures with tensile strain-hardening behavior and high damage tolerance. To monitor the behavior of this new class of material in the field, low-cost wireless monitoring technologies will be adopted to provide HPFRCC structural elements the capability to accurately monitor their performance and health. In particular, the computational core of a wireless sensing unit can be harnessed to screen HPFRCC components for damage in real-time. A seismic damage index initially proposed for flexure dominated reinforced concrete elements is modified to serve as an algorithmic tool for the rapid assessment of damage (due to flexure and shear) in HPFRCC bridge piers subjected to large shear reversals. Traditional and non-traditional sensor strategies of an HPFRCC bridge pier are proposed to optimize the correlation between the proposed damage index model and the damage observed in a circular pier test specimen. Damage index models are shown to be a sufficiently accurate rough measure of the degree of local-area damage that can then be wirelessly communicated to bridge officials.

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

    SciTech Connect

    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.

  19. Full scale strain monitoring of a suspension bridge using high performance distributed fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Xu, Jinlong; Dong, Yongkang; Zhang, Zhaohui; Li, Shunlong; He, Shaoyang; Li, Hui

    2016-12-01

    This paper investigated field monitoring of a 1108 m suspension bridge during an assessment load test, using integrated distributed fibre-optic sensors (DFOSs). In addition to the conventional Brillouin time domain analysis system, a high spatial resolution Brillouin system using the differential pulse-width pair (DPP) technique was adopted. Temperature compensation was achieved using a Raman distributed temperature sensing system. This is the first full scale field application of DFOSs using the Brillouin time domain analysis technique in a thousand-meter-scale suspension bridge. Measured strain distributions along the whole length of the bridge were presented. The interaction between the main cables and the steel-box-girder was highlighted. The Brillouin fibre-optic monitoring systems exhibited great facility for the purposes of long distance distributed strain monitoring, with up to 0.05 m spatial resolution, and 0.01 m/point sampling interval. The performance of the Brillouin system using DPP technique was discussed. The measured data was also employed for assessing bridge design and for the assessment of structural condition. The results show that the symmetrical design assumptions were consistent with the actual bridge, and that the strain values along the whole bridge were within the safety range. This trial field study serves as an example, demonstrating the feasibility of highly dense strain and temperature measurement for large scale civil infrastructures using integrated DFOSs.

  20. Application of an automated wireless structural monitoring system for long-span suspension bridges

    SciTech Connect

    Kurata, M.; Lynch, J. P.; Linden, G. W. van der; Hipley, P.; Sheng, L.-H.

    2011-06-23

    This paper describes an automated wireless structural monitoring system installed at the New Carquinez Bridge (NCB). The designed system utilizes a dense network of wireless sensors installed in the bridge but remotely controlled by a hierarchically designed cyber-environment. The early efforts have included performance verification of a dense network of wireless sensors installed on the bridge and the establishment of a cellular gateway to the system for remote access from the internet. Acceleration of the main bridge span was the primary focus of the initial field deployment of the wireless monitoring system. An additional focus of the study is on ensuring wireless sensors can survive for long periods without human intervention. Toward this end, the life-expectancy of the wireless sensors has been enhanced by embedding efficient power management schemes in the sensors while integrating solar panels for power harvesting. The dynamic characteristics of the NCB under daily traffic and wind loads were extracted from the vibration response of the bridge deck and towers. These results have been compared to a high-fidelity finite element model of the bridge.