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 Central

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

    2010-01-01

    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, cooperativity in networked salt bridges, inclusion within metal-binding sites, preference for acidic electrons, apparent conformational side chain entropy reduction upon 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. PMID:21287621

  4. 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.

  5. Bridge capacitor bank design and operation

    SciTech Connect

    Andrei, R.G.; Kaushik, R.R.; Reinaker, R.W.

    1996-01-01

    The concept of a bridge capacitor bank installation was presented in a previous paper. This paper discusses design and operation aspects related to the installation of a bridge capacitor bank in a substation. The 138/69 kV bridge capacitor bank installation presented is analyzed. An automatic switching control relay scheme for the same test installation is also discussed. The control scheme takes into account the dual effect a bridge capacitor installation has upon the electrical power system: it generates reactive power on the station 138 kV bus and transfers reactive power from the 69 kV to the 138 kV bus. An unbalance protection scheme preventing the cascading type failure of the capacitor units in the 138/69 kV bridge capacitor bank is also presented. An unbalance protection scheme for high voltage, large MVAr size bridge capacitor banks is also discussed. Simple analytical formulas with practical value to evaluate the magnitude and frequency of the voltage transients generated by the energization of a bridge capacitor bank are presented. Recorded switching transient magnitudes and frequencies are compared with calculated values.

  6. 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…

  7. 114. SKETCHES OF BRIDGE DESIGN PROPOSALS (DANBURG AND MERWINS ...

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

    114. SKETCHES OF BRIDGE - DESIGN PROPOSALS (DANBURG AND MERWINS LANE) FOR THE MERRITT PARKWAY, BY GEORGE DUNKELBERGER. - Merritt Parkway, Beginning in Greenwich & running 38 miles to Stratford, Greenwich, Fairfield County, CT

  8. 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.

  9. 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…

  10. 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.

  11. A Bridge for Accelerating Materials by Design

    DOE PAGES

    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.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

  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. Basis of Design and Seismic Action for Long Suspension Bridges: the case of the Messina Strait Bridge

    SciTech Connect

    Bontempi, Franco

    2008-07-08

    The basis of design for complex structures like suspension bridges is reviewed. Specific attention is devoted to seismic action and to the performance required and to the connected structural analysis. Uncertainty is specially addressed by probabilistic and soft-computing techniques. The paper makes punctual reference to the work end the experience developed during the last years for the re-design of the Messina Strait Bridge.

  14. Bridging the gap between building science and design studios

    SciTech Connect

    Papamichael, Konstantinos; Pal, Vineeta

    2002-02-06

    Design studios and building science courses have been conducted independent of each other, mainly due to a lack of tools that allow quick and easy consideration of building science criteria, such as comfort and energy requirements, during the design process. Existing tools are not user-friendly and their use requires significant effort in gaining familiarity with the input requirements, understanding the modeling assumptions and interpreting the output. This paper is about the Building Design Advisor (BDA), an evolving computer-based tool intended to bridge the gap between design studios and building science considerations by addressing the above-mentioned limitations of existing tools. BDA allows automatic preparation of input files to multiple simulation tools while the user is working in a CAD environment. BDA automatically activates the relevant simulation tools when the user selects performance parameters to be computed and provides the results in a graphical form, allowing comparison of multiple design options with respect to multiple performance criteria. The paper includes considerations for the use of the BDA in the design studio and ends with a description of the current development efforts and future plans.

  15. Design and performance evaluation of the NIST digital impedance bridge

    SciTech Connect

    Waltrip, B.C.; Oldham, N.M.

    1994-12-31

    An impedance bridge that compares two-terminal standard inductors to characterized resistors is described. A dual-channel digitally synthesized source and sampling digital multimeter are used to generate and measure relevant bridge signals. A linear interpolation algorithm is used to autocalibrate the bridge to a 1 nF air-dielectric capacitor An intercomparison of the new bridge with existing measurement standards in the low audio frequency range for inductors from 1 mH to 10 H will be reported.

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

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... life consistent with 25 CFR part 170, Subpart D, Appendix B and 23 CFR part 625. (b) Rehabilitation—Bridges to be rehabilitated, as a minimum, should conform to the standards of 23 CFR part 625, Design... 23 Highways 1 2014-04-01 2014-04-01 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, 2011 CFR

    2011-04-01

    ... life consistent with 25 CFR part 170, Subpart D, Appendix B and 23 CFR part 625. (b) Rehabilitation—Bridges to be rehabilitated, as a minimum, should conform to the standards of 23 CFR part 625, Design... 23 Highways 1 2011-04-01 2011-04-01 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, 2012 CFR

    2012-04-01

    ... life consistent with 25 CFR part 170, Subpart D, Appendix B and 23 CFR part 625. (b) Rehabilitation—Bridges to be rehabilitated, as a minimum, should conform to the standards of 23 CFR part 625, Design... 23 Highways 1 2012-04-01 2012-04-01 false What standards should be used for bridge design?...

  19. 23 CFR 661.53 - What standards should be used for bridge design?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... life consistent with 25 CFR part 170, Subpart D, Appendix B and 23 CFR part 625. (b) Rehabilitation—Bridges to be rehabilitated, as a minimum, should conform to the standards of 23 CFR part 625, Design... 23 Highways 1 2013-04-01 2013-04-01 false What standards should be used for bridge design?...

  20. 23 CFR 661.53 - What standards should be used for bridge design?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... life consistent with 25 CFR part 170, Subpart D, Appendix B and 23 CFR part 625. (b) Rehabilitation—Bridges to be rehabilitated, as a minimum, should conform to the standards of 23 CFR part 625, Design... 23 Highways 1 2010-04-01 2010-04-01 false What standards should be used for bridge design?...

  1. 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

  2. Design Of Bridges For Non Synchronous Seismic Motion

    SciTech Connect

    Nuti, Camillo; Vanzi, Ivo

    2008-07-08

    this paper aims to develop and validate structural design criteria which account for the effects of earthquakes spatial variability. In past works [1, 2] the two simplest forms of this problem were dealt with: differential displacements between two points belonging to the soil or to two single degree of freedom structures. Seismic action was defined according to EC8 [3]; the structures were assumed linear elastic sdof oscillators. Despite this problem may seem trivial, existing codes models appeared improvable on this aspect. For the differential displacements of two points on the ground, these results are now validated and generalized using the newly developed response spectra contained in the new seismic Italian code [4]; the resulting code formulation is presented. Next, the problem of statistically defining the differential displacement among any number of points on the ground (which is needed for continuos deck bridges) is approached, and some preliminary results shown. It is also shown that the current codes (e.g. EC8) rules may be improved on this aspect.

  3. 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.

  4. Computational design of donor-bridge-acceptor systems exhibiting pronounced quantum interference effects.

    PubMed

    Gorczak, Natalie; Renaud, Nicolas; Galan, Elena; Eelkema, Rienk; Siebbeles, Laurens D A; Grozema, Ferdinand C

    2016-03-01

    Quantum interference is a well-known phenomenon that dictates charge transport properties of single molecule junctions. However, reports on quantum interference in donor-bridge-acceptor molecules are scarce. This might be due to the difficulties in meeting the conditions for the presence of quantum interference in a donor-bridge-acceptor system. The electronic coupling between the donor, bridge, and acceptor moieties must be weak in order to ensure localised initial and final states for charge transfer. Yet, it must be strong enough to allow all bridge orbitals to mediate charge transfer. We present the computational route to the design of a donor-bridge-acceptor molecule that features the right balance between these contradicting requirements and exhibits pronounced interference effects.

  5. 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.

  6. 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

  7. Protein Thermal Stability Enhancement by Designing Salt Bridges: A Combined Computational and Experimental Study

    PubMed Central

    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

  8. 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.

  9. 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. PMID:26405963

  10. 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.

  11. Designing a bridge for consciousness: are criteria for a unification of approaches feasible?

    PubMed

    Miller, D W

    2000-01-01

    Different intrinsic rules of functioning for body and mind are overemphasized by the mutually exclusive methods of investigation in both consciousness and the sciences. Classical science, alternative and complementary healing, quantum physics, and metaphysics all take drastically different approaches to consciousness research. A bridge is needed to restore the conceptual unity of mind-body. However, the construction of such a bridge paradoxically must rely on consciousness for information. The construction company (Consciousness, Inc.) therefore becomes means and end in the design of the bridge. This piece argues that the methods of each discipline contain research tools and resources to create a bridge that satisfies a unified multidimensional and multidisciplinary conception. The piece further suggests that the framework of the bridge must place consciousness as a partner to physiology in the evolutionary trajectory of life, since problems of survival are a primary consideration in the activity of both. Finally, the piece develops six criteria by which to evaluate the effectiveness of any construction design. PMID:10835764

  12. Designing a bridge for consciousness: are criteria for a unification of approaches feasible?

    PubMed

    Miller, D W

    2000-01-01

    Different intrinsic rules of functioning for body and mind are overemphasized by the mutually exclusive methods of investigation in both consciousness and the sciences. Classical science, alternative and complementary healing, quantum physics, and metaphysics all take drastically different approaches to consciousness research. A bridge is needed to restore the conceptual unity of mind-body. However, the construction of such a bridge paradoxically must rely on consciousness for information. The construction company (Consciousness, Inc.) therefore becomes means and end in the design of the bridge. This piece argues that the methods of each discipline contain research tools and resources to create a bridge that satisfies a unified multidimensional and multidisciplinary conception. The piece further suggests that the framework of the bridge must place consciousness as a partner to physiology in the evolutionary trajectory of life, since problems of survival are a primary consideration in the activity of both. Finally, the piece develops six criteria by which to evaluate the effectiveness of any construction design.

  13. The Roaring River Bridge Design Project. High-Technology Training Module.

    ERIC Educational Resources Information Center

    Huftel, Joseph; Rademaker, William

    This training module on the Roaring River bridge design project was developed for a problem-solving unit in a ninth-grade research and development course. This project requires six to seven class periods and requires students to work in teams of two. The project contains the following information: level; time required; description; objectives;…

  14. 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…

  15. 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.…

  16. 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…

  17. 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)

  18. 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.

  19. 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.

  20. 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. PMID:26538634

  1. 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.

  2. 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.

  3. Design of adaptive dead-time control circuit for resonant half-bridge driver

    NASA Astrophysics Data System (ADS)

    Shi, Ling-Feng; Liu, Fu-Bo; He, Hui-Sen; Mao, Xiang-Yu; Lai, Xin-Quan

    2013-10-01

    To decrease the switching loss and the dead-time effect of resonant half-bridge inverter, a novel adaptive dead-time control circuit of resonant half-bridge driver Integrated Circuit (IC) is presented. Without increasing the pin number of IC, this circuit takes a novel strategy to adaptively regulate dead time to a temperate range between high and low thresholds. The high and low thresholds are adaptive to the fall time of output signal in a half-bridge clock cycle. The IC of the designed circuit is suitable for high-voltage applications. The dead-time regulation range of this circuit achieves 0-3.5 µs. The range of temperate dead-time state is 300 ns. The failure signal of this circuit can protect the IC and peripheral power devices by regulating operation in three clock cycles. Both simulation and measurement of the proposed circuit in a half-bridge driver IC with an operating frequency at 50 kHz are presented based on the 0.5 µm 700 V BCD process. The results of simulation and measurement show that the presented circuits' performance is perfect.

  4. The Principle of the Micro-Electronic Neural Bridge and a Prototype System Design.

    PubMed

    Huang, Zong-Hao; Wang, Zhi-Gong; Lu, Xiao-Ying; Li, Wen-Yuan; Zhou, Yu-Xuan; Shen, Xiao-Yan; Zhao, Xin-Tai

    2016-01-01

    The micro-electronic neural bridge (MENB) aims to rebuild lost motor function of paralyzed humans by routing movement-related signals from the brain, around the damage part in the spinal cord, to the external effectors. This study focused on the prototype system design of the MENB, including the principle of the MENB, the neural signal detecting circuit and the functional electrical stimulation (FES) circuit design, and the spike detecting and sorting algorithm. In this study, we developed a novel improved amplitude threshold spike detecting method based on variable forward difference threshold for both training and bridging phase. The discrete wavelet transform (DWT), a new level feature coefficient selection method based on Lilliefors test, and the k-means clustering method based on Mahalanobis distance were used for spike sorting. A real-time online spike detecting and sorting algorithm based on DWT and Euclidean distance was also implemented for the bridging phase. Tested by the data sets available at Caltech, in the training phase, the average sensitivity, specificity, and clustering accuracies are 99.43%, 97.83%, and 95.45%, respectively. Validated by the three-fold cross-validation method, the average sensitivity, specificity, and classification accuracy are 99.43%, 97.70%, and 96.46%, respectively.

  5. Design and construction of an open multistranded beta-sheet polypeptide stabilized by a disulfide bridge.

    PubMed

    Venkatraman, Janani; Nagana Gowda, Gowda A; Balaram, Padmanabhan

    2002-05-01

    The design and characterization of an open eight-stranded beta-sheet in a synthetic, 2-fold symmetric 70-residue peptide is described. The design strategy involves the generation of a 35-residue four-stranded beta-sheet peptide in which successive hairpins are nucleated by appropriately positioned (D)Pro-Xxx sequences. Oxidative dimerization using a single Cys residue positioned at the center of the C-terminal strand results in a disulfide-bridged eight-stranded structure. Nuclear Overhauser effects firmly establish an eight-stranded beta-sheet in methanol. In water, the outer strands are frayed, but a well-defined four-stranded beta-sheet stabilized by a disulfide bridge and a hydrophobic cluster is determined from NMR data. Comparison of the precursor peptide with the disulfide-bridged dimer reveals considerable enhancement of beta-sheet content in the latter, suggesting that the disulfide cross-link is an effective strategy for the stabilization of beta-sheets.

  6. Intrinsic Disorder-Based Design of Stabilizing Disulphide Bridge in Gαo Protein.

    PubMed

    Nagibina, Galina S; Tin, Ulyana F; Glukhov, Anatoly S; Melnik, Tatiana N; Melnik, Bogdan S

    2016-01-01

    In this study, we have used an approach that allows us to determine in what region of the polypeptide chain of protein it is required to insert a disulphide bond in order to stabilize it. In our previous paper [Melnik et al., JBSD. 2012] it was proposed that to search for a "weak" site in the protein, it is possible to use programs (for example, PONDR-FIT and IsUnstruct) finding intrinsic disorder protein regions. We suggested that in structured globular proteins, such programs predict not protein regions in the polypeptide chain disordered under native conditions, but "weakened", feebly stabilized ones. Accordingly, an artificial introduction of SS-bridges using mutations in such regions would reliably result in the protein stabilization. We have taken advantage of this approach to stabilize protein Gαo from Drosophila melanogaster. The designed SS-bridge increased by 4 degrees the melting temperature of one domain of protein Gαo.

  7. Bridging the gap from mask to physical design for multiple patterning lithography

    NASA Astrophysics Data System (ADS)

    Yu, Bei; Gao, Jhih-Rong; Xu, Xiaoqing; Pan, David Z.

    2014-03-01

    Due to the delay of EUVL, multiple patterning techniques have been used to extend the 193nm lithography to 22nm/14nm nodes, and possibly further. There are many studies on MPL layout decompositions at the mask synthesis stage to resolve the coloring conflicts, minimize the stitches, balance the mask density, or even mitigate the undesirable overlay effects. Meanwhile, there are studies showing that it is very important to consider the multiple patterning implications at earlier physical design stages so that the overall design and manufacturing closure can be reached. In this paper, we will show some recent results and propose a unified physical design methodology for standard cell compliance, pin access, routing, and placement to bridge the gap from mask/layout decomposition to physical design, while accommodating various requirements from double/triple patterning lithography in certain "correct by construction" manner.

  8. 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

  9. 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

    Calladine, C R

    2015-04-13

    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.

  10. 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

    Calladine, C R

    2015-04-13

    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

  11. 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

  12. Highway bridge seismic design: Summary of FHWA/MCEER project on seismic vulnerability of new highway construction

    NASA Astrophysics Data System (ADS)

    Friedland, Ian M.; Buckle, Ian G.; Lee, George C.

    2002-06-01

    The Federal Highway Administration (FHWA) sponsored a large, multi-year project conducted by the Multidisciplinary Center for Earthquake Engineering Research (MCEER) titled “Seismic Vulnerability of New Highway Construction” (MCEER Project 112), which was completed in 1998. MCEER coordinated the work of many researchers, who performed studies on the seismic design and vulnerability analysis of highway bridges, tunnels, and retaining structures. Extensive research was conducted to provide revisions and improvements to current design and detailing approaches and national design specifications for highway bridges. The program included both analytical and experimental studies, and addressed seismic hazard exposure and ground motion input for the U.S. highway system; foundation design and soil behavior; structural importance, analysis, and response; structural design issues and details; and structural design criteria.

  13. 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. PMID:26444905

  14. 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.

  15. 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.

  16. 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

  17. Using a Bridging Representation and Social Interactions to Foster Conceptual Change: Designing and Evaluating an Instructional Sequence for Newton's Third Law

    ERIC Educational Resources Information Center

    Savinainen, Antti; Scott, Philip; Viiri, Jouni

    2005-01-01

    This paper offers an account of, and findings from, an approach to designing and evaluating an instructional sequence set in the context of Newton's third law. The design of the sequence draws upon conceptual change theory and the concept of the "bridging analog" is extended to introduce the notion of a "bridging representation" Attention is also…

  18. 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.

  19. 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.

  20. 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. PMID:24685272

  1. Design and fabrication of indium phosphide air-bridge waveguides with MEMS functionality

    NASA Astrophysics Data System (ADS)

    Ng, Wing H.; Podoliak, Nina; Horak, Peter; Wu, Jiang; Liu, Huiyun; Stewart, William J.; Kenyon, Anthony J.

    2015-05-01

    We present the design and fabrication of a dual air-bridge waveguide structure integrated with MEMS functionality. The structure is designed to function as a tunable optical buffer for telecommunication application. The optical buffer structure is based on two parallel waveguides made of high refractive index material with subwavelength dimensions. They are suspended in air, and are separated by a sub-micron air gap. Due to the fact that the size of the waveguides is much smaller than the wavelength of light that propagates in the structure, a significant fraction of the optical mode is in the air gap between the waveguides. By changing the size of the air gap using MEMS techniques, we can vary this fraction and hence the effective refractive index of the waveguide structure, thus generating tunable optical delay. The optical buffer structure was grown on an InP substrate by molecular beam epitaxy, and the device layer was made of InGaP. An InGaAs layer was sandwiched between the device layer and the substrate to serve as a sacrificial layer. The sub-micron waveguides, their supports in the form of side pillars with tapered shapes in order to minimize optical losses, and the MEMS structures were patterned using electron beam lithography and plasma etching. Electrodes were integrated into the structure to provide electrostatic actuation. After the sample patterning, the waveguide structure was released using HF etch. Our simulations predict that by varying the waveguide separation from 50 nm to 500 nm, we could achieve a change in propagation delay by a factor of two.

  2. SOLERAS - Solar Energy Water Desalination Project: Chicago Bridge and Iron Company. System design final report. Volume 1. Design report

    SciTech Connect

    Not Available

    1986-01-01

    Chicago Bridge and Iron Company (CBI), based on a demonstrated breakthrough in freeze desalination is proposing an indirect bulk freeze desalination process for seawater that is uniquely integrated with a stand alone solar cogeneration power plant. Working under SOLERAS auspices, CBI and Foster Miller Associates (FMA) have designed an integrated power system consisting of modular parabolic dish point focus solar energy collection, molten salt thermal energy storage, and a conventional steam turbine. The shaft power provides electrical energy needs via a generator and vapor compression energy needs via compressors. The vapor compression and turbine exhaust heat provide the refrigeration required for the unique freeze desalination process. Efficient energy utilization is achieved by using high grade heat to produce compression refrigeration. The flexibility of this system in making use of available energy and certain inherent advantages of the freeze desalination process make it very attractive. The desalination process includes seawater precooling and freezing, ice separation, washing, and melting to produce fresh water. Brine concentrate is rejected back to the sea after heat exchange with feed seawater.

  3. 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.

  4. 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.

  5. Multilayer insulation for the interconnect region in the Accelerator System String Test: A practical engineering approach for a new scheme of design and installation bridges

    SciTech Connect

    Baritchi, D.; Jalloh, A.

    1993-04-01

    In order to minimize the heat leak in the Accelerator System String Test (ASST) inter-connect region, shield bridges and multilayer insulation (MLI) are provided. A sliding joint between shield bridges on adjacent magnets accommodates the contraction that occurs during cooldown. In the original design of the MLI bridges, thermal contraction was provided for by compressing the MLI. During assembly of the interconnect region, it was realized that there was not enough room for the required compression. This resulted in a redesign of the MLI bridges. The new scheme involves splitting and overlapping the MLI. This scheme has worked very well in subsequent assembly of the interconnect region. In this paper, we are going to present the new design scheme. We will also compare this design with the original design and present its advantages.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 47 CFR 80.331 - Bridge-to-bridge communication procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Bridge-to-bridge communication procedure. 80..., Alarm, Urgency and Safety Procedures § 80.331 Bridge-to-bridge communication procedure. (a) Vessels subject to the Bridge-to-Bridge Act transmitting on the designated navigational frequency must...

  11. 47 CFR 80.331 - Bridge-to-bridge communication procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Bridge-to-bridge communication procedure. 80..., Alarm, Urgency and Safety Procedures § 80.331 Bridge-to-bridge communication procedure. (a) Vessels subject to the Bridge-to-Bridge Act transmitting on the designated navigational frequency must...

  12. 47 CFR 80.331 - Bridge-to-bridge communication procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Bridge-to-bridge communication procedure. 80..., Alarm, Urgency and Safety Procedures § 80.331 Bridge-to-bridge communication procedure. (a) Vessels subject to the Bridge-to-Bridge Act transmitting on the designated navigational frequency must...

  13. 47 CFR 80.331 - Bridge-to-bridge communication procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Bridge-to-bridge communication procedure. 80..., Alarm, Urgency and Safety Procedures § 80.331 Bridge-to-bridge communication procedure. (a) Vessels subject to the Bridge-to-Bridge Act transmitting on the designated navigational frequency must...

  14. 47 CFR 80.331 - Bridge-to-bridge communication procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Bridge-to-bridge communication procedure. 80..., Alarm, Urgency and Safety Procedures § 80.331 Bridge-to-bridge communication procedure. (a) Vessels subject to the Bridge-to-Bridge Act transmitting on the designated navigational frequency must...

  15. 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.

  16. 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.

  17. 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

  18. 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…

  19. Formal Functional Test Designs: Bridging the Gap Between Test Requirements and Test Specifications

    NASA Technical Reports Server (NTRS)

    Hops, Jonathan

    1993-01-01

    This presentation describes the testing life cycle, the purpose of the test design phase, and test design methods and gives an example application. Also included is a description of Test Representation Language (TRL), a summary of the language, and an example of an application of TRL. A sample test requirement and sample test design are included.

  20. Design and testing of a low-power wireless sensor network for structural health monitoring of bridges

    NASA Astrophysics Data System (ADS)

    Harms, T.; Banks, B.; Sedigh Sarvestani, S.; Bastianini, F.

    2009-03-01

    This paper describes the design and testing of a wireless sensor network based on the SmartBrick, a low-power SHM device developed by the authors. The SmartBrick serves as the base station for the network, which utilizes additional sensor nodes to periodically evaluate the condition of the structure. Each node measures vibration, tilt, humidity, and strain, and is designed for easy interfacing of virtually any other analog or digital sensor. The sensor nodes use Zigbee to transmit their data to the base station, which in turn uses the GSM cellular phone network to provide long-range communication and support for remote control. The system has been designed from the outset to minimize power consumption, and is projected to operate autonomously for up to four years without any on-site maintenance, due largely to the minimal power consumption and rugged design. Remote calibration over the GSM network further increases the autonomy of the system. Most importantly, it can perform all requisite actions with no cables for power or communication. The focus of this paper is the addition of short-range wireless communication over Zigbee. This allows a network of several devices to be used to monitor larger structures, such as multi-span bridges. Results of laboratory testing are included and discussed in detail, demonstrating the unique capabilities of the proposed SHM system.

  1. Enhancing the thermostability of a cold-active lipase from Penicillium cyclopium by in silico design of a disulfide bridge.

    PubMed

    Tan, Zhongbiao; Li, Jianfang; Wu, Minchen; Wang, Junqing

    2014-08-01

    Cysteine mutants of a cold-active lipase (PcLipI) from Penicillium cyclopium were designed by the software Disulfide by Design Ver. 1.20 in an effort to improve enzyme thermostability by addition of a disulfide bridge. Those mutants predicted by molecular dynamics simulation to have better thermostability than the wild type were first expressed in Escherichia coli BL21(DE3) and then, for further investigation, in Pichia pastoris GS115. By replacing Val248 and Thr251 with cysteines to create a disulfide bridge, the recombinant lipases reE-PcLipV248C-T251C (expressed in E. coli) and reP-PcLipV248C-T251C (expressed in P. pastoris) were obtained. Both had enhanced thermostability with half-lives at 35 °C about 4.5- and 12.8-fold longer than that of the parent PcLipI expressed in E. coli and P. pastoris, respectively. The temperature optima of reE-PcLipV248C-T251C and reP-PcLipV248C-T251C were 35 and 30 °C, which were each 5 °C higher than those of the parent PcLipI expressed in E. coli and P. pastoris. The K ms of reE-PcLipV248C-T251C and reP-PcLipV248C-T251C toward tributyrin were 53.2 and 39.5 mM, while their V maxs were 1,460 and 3,800 U/mg, respectively. PcLipV248C-T251C had better thermostability and catalytic efficiency than the other mutants and the parent PcLipI.

  2. The active-bridge oscillator

    SciTech Connect

    Wessendorf, K.O.

    1998-07-01

    This paper describes the Active-Bridge Oscillator (ABO), a new concept in high-stability oscillator design. The ABO is ab ridge-type oscillator design that is easly to design and overcomes many of the operational and design difficulties associated with standard bridge oscillator designs. The ABO will oscillate with a very stable output amplitude over a wide range of operating conditions without the use of an automatic-level-control (ALC). A standard bridge oscillator design requires an ALC to maintain the desired amplitude of oscillation. for this and other reasons, bridge oscilaltors are not used in mainstream designs. Bridge oscillators are generally relegated to relatively low-volume, high-performance applications. The Colpitts and Pierce designs are the most popular oscillators but are typically less stable than a bridge-type oscillator.

  3. Project ProBase and the Process to Design Bridge Competencies for Community College Technical Programs

    ERIC Educational Resources Information Center

    Custer, Rodney L.; Daugherty, Michael K.

    2004-01-01

    Project ProBase (problem-based technology curriculum) is a National Science Foundation funded project designed to develop an innovative curriculum that more adequately prepares high school technology education students for success in advanced technical studies at the community college level. The purpose of the project is to design and test…

  4. Uptake and Use of Technology: Bridging Design for Teaching and Learning

    ERIC Educational Resources Information Center

    Hauge, Trond Eiliv

    2014-01-01

    This paper demonstrates the need for taking a design perspective on teaching and learning in the study of the uptake and use of information and communication technologies (ICT) in education. It argues for the identification and scrutiny of designs for teaching and learning at the institutional level to overcome the contradictions that often arise…

  5. 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…

  6. Using a bridging representation and social interactions to foster conceptual change: Designing and evaluating an instructional sequence for Newton's third law

    NASA Astrophysics Data System (ADS)

    Savinainen, Antti; Scott, Philip; Viiri, Jouni

    2005-03-01

    This paper offers an account of, and findings from, an approach to designing and evaluating an instructional sequence set in the context of Newton's third law. The design of the sequence draws upon conceptual change theory and the concept of the bridging analog is extended to introduce the notion of a bridging representation Attention is also given in the instructional design to the proposed social interactions between teacher and students as the teaching and learning activities are played out or stage in the classroom. A range of instruments is used to measure the extent of student learning, and evidence is presented to indicate that the designed sequence leads to enhanced learning gains when compared to those achieved with an equivalent group of students. Although set in the context of teaching and learning about mechanics a number of general points are made in relation to both instructional design and perspectives on conceptual change.

  7. 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.

  8. 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

    2016-05-01

    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.

  9. 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. PMID:11541148

  10. Read To Succeed: MECCA Summer Learning Camp. Manual To Design and Deliver a Summer Bridges Program.

    ERIC Educational Resources Information Center

    Illinois State Board of Education, Springfield.

    This manual presents information on designing and delivering a summer learning program whose goal is to provide an opportunity for students to experience academic success and positive self-esteem through reading fluency and comprehension. Sections of the manual address background and policies (on student and teacher selection, student promotion,…

  11. 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…

  12. Bridging the gap: a roadmap to breaking the biological design barrier.

    PubMed

    Beal, Jacob

    2014-01-01

    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

  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. 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.

  16. 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

  17. Bridging Differences in Outcomes of Pharmacoepidemiological Studies: Design and First Results of the PROTECT Project

    PubMed Central

    Abbing-Karahagopian, Victoria; Kurz, Xavier; de Vries, Frank; van Staa, Tjeerd P.; Alvarez, Yolanda; Hesse, Ulrik; Hasford, Joerg; Liset van, Dijk; Francisco J. de, Abajo; Weil, John G.; Lamiae Grimaldi, -Bensouda; Egberts, Antoine C.G.; Robert F., Reynolds; Olaf H., Klungel

    2014-01-01

    Background: Observational pharmacoepidemiological (PE) studies on drug safety have produced discrepant results that may be due to differences in design, conduct and analysis. Purpose: The pharmacoepidemiology work-package (WP2) of the Pharmacoepidemiological Research on Outcomes of Therapeutics by a European ConsorTium (PROTECT) project aims at developing, testing and disseminating methodological standards for design, conduct and analysis of pharmacoepidemiological studies applicable to different safety issues using different databases across European countries. This article describes the selection of the safety issues and the description of the databases to be systematically studied. Methods: Based on two consensus meetings and a literature search, we selected five drug-adverse event (AE) pairs to be evaluated in different databases. This selection was done according to pre-defined criteria such as regulatory and public health impact, and the potential to investigate a broad range of methodological issues. Results: The selected drug-AE pairs are: 1) inhaled long-acting beta-2 agonists and acute myocardial infarction; 2) antimicrobials and acute liver injury; 3) antidepressants and/or benzodiazepines and hip fracture; 4) anticonvulsants and suicide/suicide attempts; and 5) calcium channel blockers and malignancies. Six European databases, that will be used to evaluate the drug-AE pairs retrospectively, are also described. Conclusion: The selected drug-AE pairs will be evaluated in PE studies using common protocols. Based on consistencies and discrepancies of these studies, a framework for guiding methodological choices will be developed. This will increase the usefulness and reliability of PE studies for benefit-risk assessment and decision-making. PMID:24218995

  18. 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.

  19. 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.

  20. 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.

  1. Myocardial Bridging

    PubMed Central

    Yuan, Shi-Min

    2016-01-01

    Myocardial bridging is rare. Myocardial bridges are most commonly localized in the middle segment of the left anterior descending coronary artery. The anatomic features of the bridges vary significantly. Alterations of the endothelial morphology and the vasoactive agents impact on the progression of atherosclerosis of myocardial bridging. Patients may present with chest pain, myocardial infarction, arrhythmia and even sudden death. Patients who respond poorly to the medical treatment with β-blockers warrant a surgical intervention. Myotomy is a preferred surgical procedure for the symptomatic patients. Coronary stent deployment has been in limited use due to the unsatisfactory long-term results. PMID:27074276

  2. 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.

  3. Development of inspection robots for bridge cables.

    PubMed

    Yun, Hae-Bum; Kim, Se-Hoon; Wu, Liuliu; 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.

  4. Development of inspection robots for bridge cables.

    PubMed

    Yun, Hae-Bum; Kim, Se-Hoon; Wu, Liuliu; 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

  5. 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

  6. 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.

  7. Hydration properties of ligands and drugs in protein binding sites: tightly-bound, bridging water molecules and their effects and consequences on molecular design strategies.

    PubMed

    García-Sosa, Alfonso T

    2013-06-24

    Some water molecules in binding sites are important for intermolecular interactions and stability. The way binding site explicit water molecules are dealt with affects the diversity and nature of designed ligand chemical structures and properties. The strategies commonly employed frequently assume that a gain in binding affinity will be achieved by their targeting or neglect. However, in the present work, 2332 high-resolution X-ray crystal structures of hydrated and nonhydrated, drug and nondrug compounds in biomolecular complexes with reported Ki or Kd show that compounds that use tightly bound, bridging water molecules are as potent as those that do not. The distribution of their energies, physicochemical properties, and ligand efficiency indices were compared for statistical significance, and the results were confirmed using 2000 permutation runs. Ligand cases were also split into agonists and antagonists, and crystal structure pairs with differing tightly bound water molecules were also compared. In addition, agonists and antagonists that use tightly bound water bridges are smaller, less lipophilic, and less planar; have deeper ligand efficiency indices; and in general, possess better physicochemical properties for further development. Therefore, tightly bound, bridging water molecules may in some cases be replaced and targeted as a strategy, though sometimes keeping them as bridges may be better from a pharmacodynamic perspective. The results suggest general indications on tightly hydrated and nontightly hydrated compounds in binding sites and practical considerations to adopt a strategy in drug and molecular design when faced with this special type of water molecules. There are also benefits of lower log P and better developability for tightly hydrated compounds, while stronger potency is not always required or beneficial. The hydrated binding site may be one of the many structure conformations available to the receptor, and different ligands will have a

  8. 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,…

  9. Propylene cross-bridged macrocyclic bifunctional chelator: a new design for facile bioconjugation and robust (64)Cu complex stability.

    PubMed

    Pandya, Darpan N; Bhatt, Nikunj; An, Gwang Il; Ha, Yeong Su; Soni, Nisarg; Lee, Hochun; Lee, Yong Jin; Kim, Jung Young; Lee, Woonghee; Ahn, Heesu; Yoo, Jeongsoo

    2014-09-11

    The first macrocyclic bifunctional chelator incorporating propylene cross-bridge was efficiently synthesized from cyclam in seven steps. After the introduction of an extra functional group for facile conjugation onto the propylene cross-bridge, the two carboxylic acid pendants could contribute to strong coordination of Cu(II) ions, leading to a robust Cu complex. The cyclic RGD peptide conjugate of PCB-TE2A-NCS was prepared and successfully radiolabeled with (64)Cu ion. The radiolabeled peptide conjugate was evaluated in vivo through a biodistribution study and animal PET imaging to demonstrate high tumor uptake with low background.

  10. 31. TACOMA NARROWS BRIDGE, LOOKING WEST ACROSS TOLL PLAZA, 29 ...

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

    31. TACOMA NARROWS BRIDGE, LOOKING WEST ACROSS TOLL PLAZA, 29 AUGUST 1940. (ELDRIDGE, CLARK M. TACOMA NARROWS BRIDGE, TACOMA, WASHINGTON, FINAL REPORT ON DESIGN AND CONSTRUCTION, 1941) - Tacoma Narrows Bridge, Spanning Narrows at State Route 16, Tacoma, Pierce County, WA

  11. 30. TACOMA NARROWS BRIDGE, LOOKING EAST THROUGH TOLL LANES, 29 ...

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

    30. TACOMA NARROWS BRIDGE, LOOKING EAST THROUGH TOLL LANES, 29 AUGUST 1940. (ELDRIDGE, CLARK H. TACOMA NARROWS BRIDGE, TACOMA, WASHINGTON, FINAL REPORT ON DESIGN AND CONSTRUCTION, 1941) - Tacoma Narrows Bridge, Spanning Narrows at State Route 16, Tacoma, Pierce County, WA

  12. Design and introduction of a disulfide bridge in firefly luciferase: increase of thermostability and decrease of pH sensitivity.

    PubMed

    Imani, Mehdi; Hosseinkhani, Saman; Ahmadian, Shahin; Nazari, Mahboobeh

    2010-08-01

    The thermal sensitivity and pH-sensitive spectral properties of firefly luciferase have hampered its application in a variety of fields. 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 two separate mutant enzymes with a single bridge. Even though the A103C/S121C mutant showed remarkable thermal stability, its specific activity decreased, whereas the A296C/A326C mutant showed tremendous thermal stability, relative pH insensitivity and 7.3-fold increase of specific activity. Moreover, the bioluminescence emission spectrum of A296C/A326C was resistant against higher temperatures (37 degrees C). Far-UV CD analysis showed slight secondary structure changes for both mutants. Thermal denaturation analysis showed that conformational stabilities of A103C/S121C and A296C/A326C are more than native firefly luciferase. It is proposed that since A296 and A326 are situated in the vicinity of the enzyme active site microenvironment in comparison with A103 and S121, the formation of a disulfide bridge in this region has more impact on enzyme kinetic characteristics.

  13. Myocardial Bridge

    MedlinePlus

    ... artery. See also on this site: Ask a Texas Heart Institute Doctor: Search "myocardial bridge" Updated August ... comments. Terms of Use and Privacy Policy © Copyright Texas Heart Institute All rights reserved.

  14. Jointless bridges

    NASA Astrophysics Data System (ADS)

    Zuk, W.

    1981-06-01

    Various methods states are employing to reduce the number of joints in bridge decks are surveyed. The most common method is the use of integral abutments, where the superstructure is jointed to a flexible type of abutment. New methods of reducing the number of joints in a bridge are analyzed mathematically, and from the analysis conclusions are drawn as to the feasibility of these methods.

  15. 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

  16. Mathematics in Use: Suspension Bridges.

    ERIC Educational Resources Information Center

    Ginther, John L.

    1992-01-01

    Reviews the mathematics utilized in the design and construction of suspension bridges, in general, then illustrates these mathematical concepts by examining data associated with the Mackinac Bridge, which connects the two peninsulas of Michigan. Emphasizes the strong interest factor these gigantic structures have for students by attaching a sense…

  17. 49 CFR 237.57 - Designations of individuals.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons... railroad bridge engineers, railroad bridge inspectors and railroad bridge supervisors. Each...

  18. 49 CFR 237.57 - Designations of individuals.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons... railroad bridge engineers, railroad bridge inspectors and railroad bridge supervisors. Each...

  19. 49 CFR 237.57 - Designations of individuals.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons... railroad bridge engineers, railroad bridge inspectors and railroad bridge supervisors. Each...

  20. 49 CFR 237.57 - Designations of individuals.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons... railroad bridge engineers, railroad bridge inspectors and railroad bridge supervisors. Each...

  1. 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.

  2. 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…

  3. 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…

  4. 49 CFR 236.713 - Bridge, movable.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 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 ADMINISTRATION... Bridge, movable. That section of a structure bridging a navigable waterway so designed that it may...

  5. 49 CFR 236.713 - Bridge, movable.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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 ADMINISTRATION... Bridge, movable. That section of a structure bridging a navigable waterway so designed that it may...

  6. 49 CFR 236.713 - Bridge, movable.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 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 ADMINISTRATION... Bridge, movable. That section of a structure bridging a navigable waterway so designed that it may...

  7. 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...

  8. 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...

  9. Bridges, 1999.

    ERIC Educational Resources Information Center

    Zito, Michael, Ed.

    1999-01-01

    This document is comprised of the two issues in volume 4 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 spring 1999 issue focuses on the service system for…

  10. 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 interest to…

  11. 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.

  12. Bridges, 1999.

    ERIC Educational Resources Information Center

    Wilcox, Bonita; Manear, John; Slifkin, Josh M.

    This volume contains articles about writing, best practice, portfolio assessment, and technology, as well as original poetry and book reviews. Articles in the volume are: "Teaching Writing: Making Connections" (Eric Schott); "Empowering Teachers: A Success Story" (Sandra L. Krivak); "Bridging the Gap between the Classroom and Employment" (Linda C.…

  13. 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.

  14. Strategy for the rational design of asymmetric triply bridged dinuclear 3d-4f single-molecule magnets.

    PubMed

    Colacio, Enrique; Ruiz-Sanchez, José; White, Fraser J; Brechin, Euan K

    2011-08-01

    Three triply bridged M(II)-Dy(III) dinuclear complexes, [Ni(μ-L)(μ-OAc)Dy(NO(3))(2)] 1, [Zn(μ-L)(μ-OAc)Dy(NO(3))(2)] 2, and [Ni(μ-L)(μ-NO(3))Dy(NO(3))(2)]·2CH(3)OH 3 were prepared with a new and flexible compartmental ligand, N,N',N″-trimethyl-N,N″-bis(2-hydroxy-3-methoxy-5-methylbenzyl)diethylene triamine (H(2)L), containing N(3)O(2)-inner and O(4)-outer coordination sites. These complexes have diphenoxo/acetate (1 and 2) or diphenoxo/nitrate (3) asymmetric bridging fragments. Compounds 1 and 3 exhibit ferromagnetic interaction between Ni(2+) and Dy(3+) ions and frequency dependence of the out-of-phase (χ″(M)) alternating current (ac) susceptibility signal characteristic of single-molecule-magnet behavior. The energy barriers Δ/k(B) for compound 3 under zero and 1000 Oe applied direct current (dc) magnetic fields were estimated from the Arrhenius plots to be 7.6 and 19.1 K, respectively.

  15. Bridge Inspector's Training Manual.

    ERIC Educational Resources Information Center

    Federal Highway Administration (DOT), Washington, DC. Bureau of Public Roads.

    A guide for the instruction of bridge inspectors is provided in this manual as well as instructions for conducting and reporting on a bridge inspection. The chapters outline the qualifications necessary to become a bridge inspector. The subject areas covered are: The Bridge Inspector, Bridge Structures, Bridge Inspection Reporting System,…

  16. 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…

  17. In Silico Rational Design and Systems Engineering of Disulfide Bridges in the Catalytic Domain of an Alkaline α-Amylase from Alkalimonas amylolytica To Improve Thermostability

    PubMed Central

    Liu, Long; Deng, Zhuangmei; Yang, Haiquan; Li, Jianghua; Shin, Hyun-dong; Chen, Rachel R.

    2014-01-01

    High thermostability is required for alkaline α-amylases to maintain high catalytic activity under the harsh conditions used in textile production. In this study, we attempted to improve the thermostability of an alkaline α-amylase from Alkalimonas amylolytica through in silico rational design and systems engineering of disulfide bridges in the catalytic domain. Specifically, 7 residue pairs (P35-G426, Q107-G167, G116-Q120, A147-W160, G233-V265, A332-G370, and R436-M480) were chosen as engineering targets for disulfide bridge formation, and the respective residues were replaced with cysteines. Three single disulfide bridge mutants—P35C-G426C, G116C-Q120C, and R436C-M480C—of the 7 showed significantly enhanced thermostability. Combinational mutations were subsequently assessed, and the triple mutant P35C-G426C/G116C-Q120C/R436C-M480C showed a 6-fold increase in half-life at 60°C and a 5.2°C increase in melting temperature compared with the wild-type enzyme. Interestingly, other biochemical properties of this mutant also improved: the optimum temperature increased from 50°C to 55°C, the optimum pH shifted from 9.5 to 10.0, the stable pH range extended from 7.0 to 11.0 to 6.0 to 12.0, and the catalytic efficiency (kcat/Km) increased from 1.8 × 104 to 2.4 × 104 liters/g · min. The possible mechanism responsible for these improvements was explored through comparative analysis of the model structures of wild-type and mutant enzymes. The disulfide bridge engineering strategy used in this work may be applied to improve the thermostability of other industrial enzymes. PMID:24212581

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

    PubMed

    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, (1)H 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.

  19. 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

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

    PubMed

    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, (1)H 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

  1. 49 CFR 237.53 - Railroad bridge inspectors.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Railroad bridge inspectors. 237.53 Section 237.53..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons § 237.53 Railroad bridge inspectors. A railroad bridge inspector shall be a person who is determined...

  2. 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...

  3. 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...

  4. 49 CFR 237.55 - Railroad bridge supervisors.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Railroad bridge supervisors. 237.55 Section 237.55..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons § 237.55 Railroad bridge supervisors. A railroad bridge supervisor shall be a person, regardless...

  5. 49 CFR 237.55 - Railroad bridge supervisors.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Railroad bridge supervisors. 237.55 Section 237.55..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons § 237.55 Railroad bridge supervisors. A railroad bridge supervisor shall be a person, regardless...

  6. 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...

  7. 49 CFR 237.53 - Railroad bridge inspectors.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Railroad bridge inspectors. 237.53 Section 237.53..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons § 237.53 Railroad bridge inspectors. A railroad bridge inspector shall be a person who is determined...

  8. 49 CFR 237.53 - Railroad bridge inspectors.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Railroad bridge inspectors. 237.53 Section 237.53..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons § 237.53 Railroad bridge inspectors. A railroad bridge inspector shall be a person who is determined...

  9. 49 CFR 237.53 - Railroad bridge inspectors.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Railroad bridge inspectors. 237.53 Section 237.53..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons § 237.53 Railroad bridge inspectors. A railroad bridge inspector shall be a person who is determined...

  10. 49 CFR 237.55 - Railroad bridge supervisors.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Railroad bridge supervisors. 237.55 Section 237.55..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons § 237.55 Railroad bridge supervisors. A railroad bridge supervisor shall be a person, regardless...

  11. 49 CFR 237.53 - Railroad bridge inspectors.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Railroad bridge inspectors. 237.53 Section 237.53..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons § 237.53 Railroad bridge inspectors. A railroad bridge inspector shall be a person who is determined...

  12. 49 CFR 237.55 - Railroad bridge supervisors.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Railroad bridge supervisors. 237.55 Section 237.55..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons § 237.55 Railroad bridge supervisors. A railroad bridge supervisor shall be a person, regardless...

  13. 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...

  14. 49 CFR 237.55 - Railroad bridge supervisors.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Railroad bridge supervisors. 237.55 Section 237.55..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons § 237.55 Railroad bridge supervisors. A railroad bridge supervisor shall be a person, regardless...

  15. 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...

  16. Steel bridge retrofit evaluation

    NASA Astrophysics Data System (ADS)

    Prine, David W.

    1998-03-01

    The development of a retrofit design aimed at retarding or eliminating fatigue crack growth in a large bridge can be a very difficult and expensive procedure. Analytical techniques frequently do not provide sufficient accuracy when applied to complex structural details. The Infrastructure Technology Institute (ITI) of Northwestern University, under contract to the California Department of Transportation (Caltrans), recently applied experimental state-of-the-art NDE technology to the Interstate 80 bridge over the Sacramento River near Sacramento, California (Bryte Bend). Acoustic emission monitoring was applied in conjunction with strain gage monitoring to aid in characterizing the retrofits' effect on existing active fatigue cracks. The combined test results clearly showed that one retrofit design was superior to the other.

  17. 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

  18. Rational design, synthesis, and biological evaluation of lactam-bridged gramicidin A analogues: discovery of a low-hemolytic antibacterial peptide.

    PubMed

    Mao, Ji; Kuranaga, Takefumi; Hamamoto, Hiroshi; Sekimizu, Kazuhisa; Inoue, Masayuki

    2015-03-01

    A linear peptide, gramicidin A (GA), folds into a β(6.3) -helix, functions as an ion channel in the cell membrane, and exerts antibacterial activity. Herein we describe the rational design, synthesis, and biological evaluation of lactam-bridged GA analogues. The GA analogue with a 27-membered macrolactam was found to adopt a stable β(6.3) -helical conformation and exhibits higher ion-exchange activity than GA. Furthermore, this GA analogue retains the potent antibiotic activity of GA, but its hemolytic activity and toxicity toward mammalian cells are significantly lower than those of GA. This study thus dissociates the antibacterial and hemolytic/cytotoxic activities of GA, and charts a rational path forward for the development of new ion-channel-based antibiotics.

  19. Two-dimensional finite element analysis of the influence of bridge design on stress distribution in bone tissues surrounding fixtures of osseointegrated implants in the lower molar region.

    PubMed

    Arataki, T; Adachi, Y; Kishi, M

    1998-08-01

    This study is a comparison and examination of the stress distribution of the bone tissues surrounding the fixture under a static vertical load condition with regard to an osseointegrated implant bridge (OIB) applied to the lower molar region. It was performed by constructing more than one of two-dimensional finite element models that differ in design conditions. In the case of the bounded type OIB design to the fixture placed in a straight line, a decrease in the maximum stress value of the compact bone surrounding the fixture was recognized with a decrease in the total inter-fixture distance and an increase in the number of placed fixtures. On the other hand, in the case of the free-end type OIB design, there is an increase in the maximum stress value compared with the bounded type OIB design and, in particular, a marked increase with the decrease in the total inter-fixture distance and the extension of the free-end pontic. However, the effect of the number of fixtures placed on the maximum stress value of the surrounding bone tissues was considered to be comparatively small.

  20. Removal of failed crown and bridge

    PubMed Central

    Rahul, G R.; Poduval, Soorya T.; Shetty, Karunakar

    2012-01-01

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

  1. Removal of failed crown and bridge.

    PubMed

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

    2012-07-01

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

  2. SOLERAS - Solar Energy Water Desalination Project: Chicago Bridge and Iron Company. Final report: system design extension. Volume 1. Technical report

    SciTech Connect

    Not Available

    1985-01-01

    The design of a solar energy powered, sea water desalination pilot plant for installation at Yanbu, Saudi Arabia, on the shore of the Red Sea is presented. Earlier work is introduced and a description of the system is presented. Important design analyses and cost reduction considerations are reviewed. The pilot plant design is described in detail. Construction plans for and projected operation of the plant are discussed.

  3. Optimal design and experiment of a three-axis out-of-plane nano positioning stage using a new compact bridge-type displacement amplifier.

    PubMed

    Lee, Hak-Jun; Kim, Hyun-Chang; Kim, Hyo-Young; Gweon, Dae-Gab

    2013-11-01

    This paper presents the development of a new compact three-axis compliant stage employing piezoelectric actuators and a new flexure structure. A proposed stage works out-of-plane (Z, θx, θy) direction. The stage consists of 4 amplification flexures mounted piezoelectric actuators. New structure of flexure reduces height and enhances dynamic performance of stage. To certify excellent performance of the stage, comparison accomplished between conventional amplification flexure and new compact bridge type flexure. Modeling and optimal design of new type nano positioning stage performed. The optimal design is executed on the geometric parameters of the proposed flexure structure using Sequential Quadratic Programming. Experiments are carried out to verify the static and dynamic performance of the stage. The proposed out-of-plane nano-positioning stage has a Z-directional motion range 190 μm and a θx, θy-directional motion range ±2 mrad. The resolution of the stage is 4 nm, 40 nrad, and 40 nrad in the Z-, θx-, and θy-directional motions, respectively. The size of stage is 150 × 150 × 30 mm(3).

  4. Impact of cross-tie design on the in-plane stiffness and local mode formation of cable networks on cable-stayed bridges

    NASA Astrophysics Data System (ADS)

    Ahmad, Javaid; Cheng, Shaohong; Ghrib, Faouzi

    2016-02-01

    Suppressing unfavorable stay cable vibrations using cross-ties is becoming more popular on cable-stayed bridges though the mechanics of the formed cable network is yet fully understood. In practice, the main task in designing cross-ties or cable networks is to choose the cross-tie installation location, stiffness and number based on the main cable properties in the network. To have a more comprehensive picture of how to choose these design parameters to achieve higher in-plane network stiffness while minimizing the number of excited local modes, it is imperative to examine dynamic behavior of cable networks with general configurations. In the current study, an analytical model of a general cable network consisting of multiple main cables interconnected by multiple lines of transverse flexible cross-ties will be developed. A new term, defined as the local mode cluster, will be introduced to assess the severity of local mode excitation. Criteria for identifying the presence of local mode cluster will be proposed. A parametric study will be conducted to evaluate the impact of cross-tie installation location, stiffness and number on the network modal response. Results obtained from the present study will provide deeper insight into the selection of these system parameters to achieve the combined benefits of increasing network in-plane stiffness and minimizing the excitation of local modes.

  5. Building bridges between theory and practice in medical education using a design-based research approach: AMEE Guide No. 60.

    PubMed

    Dolmans, Diana H J M; Tigelaar, D

    2012-01-01

    Medical education research has grown enormously over the past 20 years, but it does not sufficiently make use of theories, according to influential leaders and researchers in this field. In this AMEE Guide, it is argued that design-based research (DBR) studies should be conducted much more in medical education design research because these studies both advance the testing and refinement of theories and advance educational practice. In this Guide, the essential characteristics of DBR as well as how DBR differs from other approach such as formative evaluation are explained. It is also explained what the pitfalls and challenges of DBR are. The main challenges deal with how to insure that DBR studies reveal findings that are of a broader relevance than the local situation and how to insure that DBR contributes toward theory testing and refinement. An example of a series of DBR studies on the design of a teaching portfolio in higher education that is aimed at stimulating a teacher's professional development is described, to illustrate how DBR studies actually work in practice. Finally, it is argued that DBR-studies could play an important role in the advancement of theory and practice in the two broad domains of designing or redesigning work-based learning environments and assessment programs.

  6. 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.…

  7. THE TRUSS BRIDGE SEGMENT OF THE TRIBOROUGH BRIDGE IN FOREGROUND ...

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

    THE TRUSS BRIDGE SEGMENT OF THE TRIBOROUGH BRIDGE IN FOREGROUND AND THE HELL GATE BRIDGE IN THE BACKGROUND ADJACENT TO THE SUSPENSION SEGMENT OF THE TRIBOROUGH BRIDGE. - Triborough Bridge, Passing through Queens, Manhattan & the Bronx, Queens (subdivision), Queens County, NY

  8. A simple tool for designing a database: bridging the communication gaps among health care providers, researchers, and programmers.

    PubMed

    Phelps, L W; Lamb, S; Lyons, R W; Ripley, J; Ervin, S; Weinraub, H; Brody, K K

    1995-05-01

    As databases are used by a greater variety of people, highly technical methods of designing them are giving way to more human, user-centered approaches. The article describes a human approach to designing a complex, multiuse database with limited resources. The article introduces a simple data modeling tool, the entity-relationship (E-R) diagram, that crosses professional boundaries and enables providers, researchers, and programmers to communicate more easily. Constructing an E-R diagram provides a human description of the social health maintenance organization (S/HMO) multisite demonstration project. This project, now in its tenth year, provides integrated acute and community-based in-home services to allow frail elderly HMO members to stay in their homes. After briefly reviewing the three types of databases and three rules of thumb for designing a relational database, the article shows how a simple E-R diagram can clarify the management and research issues of the S/HMO health care model. The article concludes with a brief discussion of the benefits and limits of housing research-related health data in a relational database.

  9. 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

  10. 42. Photocopy of bridge drawing, 1923 (original in possession of ...

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

    42. Photocopy of bridge drawing, 1923 (original in possession of Wilkes-Barre City Engineer's Office) ALTERNATE DESIGN - South Street Bridge, Spans Pennsylvania Avenue, Wilkes-Barre Boulevard, Pocono Northeast Railroad, Wilkes-Barre, Luzerne County, PA

  11. Sacrificial bridges for MEMS fabrication

    NASA Astrophysics Data System (ADS)

    Chang, Chao-Min; Chen, Yang-Che; Fong, Chien-Fu; Guu, Yunn-Horng; Chen, Rongshun; Yeh, J. Andrew; Hou, Max T.

    2011-09-01

    This study discusses sacrificial bridges that are used to release MEMS devices. Before being released, sacrificial bridges connect all the component structures into an integral structure. Solder bump bonding is used to mount the MEMS chip on another chip or a printed circuit board (PCB) and to maintain the alignment among all component structures after removal of the sacrificial bridges. Two types of sacrificial bridges were designed, analyzed and fabricated. The fabrication process—which used low resistivity single crystal silicon (SCS) wafers as the device material—was developed to implement the sacrificial bridges. Novel SCS through silicon vias (TSVs), which interconnect stacked chips, was made using the same process. An electrostatic comb drive actuator was fabricated and mounted onto a PCB. The fabricated actuator was tested to demonstrate the feasibility of the fabrication process, sacrificial bridges and SCS TSVs. The results show that the actuator worked well. Its maximum displacement and resonant frequency were 69.9 µm and 406 Hz, respectively. This method is promising for the delivery of a novel 3D system in package for MEMS devices.

  12. Bridge/amplifier configuration for switched arrays

    NASA Technical Reports Server (NTRS)

    Bohning, O. D.

    1977-01-01

    Bridge network connected to differential amplifier and used with bubble-domain memories draws no power during standby and can be arrayed with other bridge amplifiers of like design. Two-node arrangement greatly simplifies conventional configurations where more than two nodes are involved.

  13. 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

  14. Bridging the Design-Manufacturing-Materials Data Gap: Material Properties for Optimum Design and Manufacturing Performance in Light Vehicle Steel-Intensive Body Structures

    NASA Astrophysics Data System (ADS)

    Zuidema, Blake K.

    2012-09-01

    As safety and fuel economy regulations become increasingly more challenging around the world, light vehicle manufacturers are facing increasing pressure to reduce the weight of their vehicles cost effectively while maintaining or improving safety performance. Optimum light vehicle steel body structure weight and performance are achieved when the constraints of design, manufacturing, and material properties are considered simultaneously. ArcelorMittal has invested heavily over the past several years to close the gap between material property knowledge and the inter-relation between material performance and design and manufacturing efficiency. Knowledge gained through this process is presented and the importance of achieving this simultaneous 3-way optimization is illustrated by a lightweight steel door design example from ArcelorMittal's S-in motion catalog of lightweight steel solutions.

  15. 49 CFR 237.131 - Design.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 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 manner... modified or repaired. Designs and procedures for repair or modification of bridges of a...

  16. 49 CFR 237.131 - Design.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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 manner... modified or repaired. Designs and procedures for repair or modification of bridges of a...

  17. 49 CFR 237.131 - Design.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 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 manner... modified or repaired. Designs and procedures for repair or modification of bridges of a...

  18. Contextual view of bridge, showing diagonal sloping up and away ...

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

    Contextual view of bridge, showing diagonal sloping up and away from either side of the bridge center typical of the basic pratt truss design (the parker truss is a variation of the pratt style). Looking southeast from upstream of the Kettle River - Orient Bridge, Spanning Kettle River at Richardson Road, Orient, Ferry County, WA

  19. 1. General view of bridge looking north. This is the ...

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

    1. General view of bridge looking north. This is the only suspension bridge in Cleveland. It was designed by Wilbur J. Watson and Associates, Consulting Engineers. Sections of the Wooden deck are missing, and the bridge is no longer used. - Sidaway Avenue Footbridge, Jackowo & Garden Valley neighborhood Vicinity, Cleveland, Cuyahoga County, OH

  20. 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.

  1. 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

  2. Cross-Quint-Bridge Resistor

    NASA Technical Reports Server (NTRS)

    Hannaman, David J.; Lieneweg, Udo; Buehler, Martin G.; Mantalas, Linda

    1991-01-01

    Integrated-circuit conductive test pattern intended to provide data on effects of design widths and design spacings upon actual widths of conductive lines. Provides for electrical measurements both on lines of unknown width and on features having known dimensions. Data from measurements on five bridges used to determine four parameters of mathematical model describing system. In principle, pattern determines effects of width and spacing and interaction between them.

  3. 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.

  4. The feasibility of castable ceramic material in dental bridge construction.

    PubMed

    Lin, T H; Chung, K H; Chan, C C

    1992-11-01

    This study was to investigate the feasibility of dental bridges constructed with castable ceramic material (Dicor). A dental bridge model was designed similar to the clinical situation. The marginal fit of Dicor crown and a three-unit bridge was evaluated and no statistically significant differences in marginal openings between Dicor crowns and bridges were determined except the mesial and distal end surfaces of the bridge works. The fracture strengths of different thicknesses of Dicor test bars were measured with a three-point bending technique in a jig mounted in a universal testing machine. The results revealed that the bridge design with the thickest (6mm) connector and the shortest (8 mm) width of the pontic had the highest fracture resistance. In addition, pores with size up to 50 microns were disclosed in the fractured interface. The optimal design of Dicor bridge is determined according to the results of this study along with the clinical trial.

  5. Violin Bridge Mobility Analysis under In-Plane Excitation

    PubMed Central

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

    2013-01-01

    The vibration of a violin bridge is a dynamic contact vibration with two interfaces: strings-bridge, and bridge feet-top plate. In this paper, the mobility of an isolated bridge under in-plane excitation is explored using finite element modeling based on the contact vibration model. Numerical results show that the dynamic contact stiffness in the two contact interfaces has a great impact on the bridge mobility. A main resonance peak is observed in the frequency range of 2–3 kHz in the 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. PMID:24217354

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

    PubMed

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

    2013-01-01

    The vibration of a violin bridge is a dynamic contact vibration with two interfaces: strings-bridge, and bridge feet-top plate. In this paper, the mobility of an isolated bridge under in-plane excitation is explored using finite element modeling based on the contact vibration model. Numerical results show that the dynamic contact stiffness in the two contact interfaces has a great impact on the bridge mobility. A main resonance peak is observed in the frequency range of 2-3 kHz in the 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. PMID:24217354

  7. 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.

  8. Microfluidic Wheatstone bridge for rapid sample analysis.

    PubMed

    Tanyeri, Melikhan; Ranka, Mikhil; Sittipolkul, Natawan; Schroeder, Charles M

    2011-12-21

    We developed a microfluidic analogue of the classic Wheatstone bridge circuit for automated, real-time sampling of solutions in a flow-through device format. We demonstrate precise control of flow rate and flow direction in the "bridge" microchannel using an on-chip membrane valve, which functions as an integrated "variable resistor". We implement an automated feedback control mechanism in order to dynamically adjust valve opening, thereby manipulating the pressure drop across the bridge and precisely controlling fluid flow in the bridge channel. At a critical valve opening, the flow in the bridge channel can be completely stopped by balancing the flow resistances in the Wheatstone bridge device, which facilitates rapid, on-demand fluid sampling in the bridge channel. In this article, we present the underlying mechanism for device operation and report key design parameters that determine device performance. Overall, the microfluidic Wheatstone bridge represents a new and versatile method for on-chip flow control and sample manipulation. PMID:22030805

  9. Partially entangled states bridge in quantum teleportation

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

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

  10. 1. WESTERN VIEW OF BRIDGE PLAZA, SHOWING MEMORIAL BRIDGE AT ...

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

    1. WESTERN VIEW OF BRIDGE PLAZA, SHOWING MEMORIAL BRIDGE AT LEFT AND THE ROCK CREEK AND POTOMAC PARKWAY RAMP AT RIGHT. VIEW TAKEN FROM THE REAR OF THE LINCOLN MEMORIAL. - Arlington Memorial Bridge, Watergate & Bridge Plaza, Adjacent to Arlington Memorial Bridge & Lincoln Memorial, Washington, District of Columbia, DC

  11. [Composite (etched) bridge].

    PubMed

    de Kloet, H J; van Pelt, A W

    1996-11-01

    An adhesive or resin-bonded bridge is a tooth saving construction for the replacement of a lost tooth, especially when the abutment teeth are relatively sound. In this article an overview is presented of the different types of resin-bonded bridges, their advantages and disadvantages and their indications. The direct methods are very suited for the immediate replacement of a lost anterior tooth. The all composite adhesive bridge has a survival rate that is surprisingly good.

  12. 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.

  13. 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.

  14. 11. Southern bridge abutment and arches, taken from old bridge ...

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

    11. Southern bridge abutment and arches, taken from old bridge abutment looking south. - Presumpscot Falls Bridge, Spanning Presumptscot River at Allen Avenue extension, 0.75 mile west of U.S. Interstate 95, Falmouth, Cumberland County, ME

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. Sulphite Railroad Bridge1896, Title Sheet Sulphite Railroad Bridge, Former ...

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

    Sulphite Railroad Bridge-1896, Title Sheet - Sulphite Railroad Bridge, Former Boston & Maine Railroad (originally Tilton & Franklin Railroad) spanning Winnipesautee River, Franklin, Merrimack County, NH

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. Modelling a Suspension Bridge.

    ERIC Educational Resources Information Center

    Rawlins, Phil

    1991-01-01

    The quadratic function can be modeled in real life by a suspension bridge that supports a uniform weight. This activity uses concrete models and computer generated graphs to discover the mathematical model of the shape of the main cable of a suspension bridge. (MDH)

  10. 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.

  11. Stereochemical constraints in peptide design: analysis of the influence of a disulfide bridge and an alpha-aminoisobutyryl residue on the conformation of a hexapeptide.

    PubMed

    Uma, K; Kishore, R; Balaram, P

    1993-06-01

    The competing effects of a disulfide bridge and an alpha-aminoisobutyryl residue (Aib) in determining the conformation of a hexapeptide have been investigated, by comparing the cyclic disulfide [sequence: see text] and the acylic peptide Boc-Cys (SBzl)-Val-Aib-Ala-Leu-Cys (SBzl)-NHMe (2). Previously published nmr and crystallographic studies [R. Kishore, S. Raghothama, and P. Balaram (1987) Biopolymers, Vol. 26, pp. 873-891; I. L. Karle, R. Kishore, S. Raghothama, & P. Balaram, (1988) Journal of the American Chemical Society Vol. 110, pp. 1958-1963] have established an antiparallel beta-hairpin structure for 1 with a central Aib-Ala beta-turn. A comparison of nmr data for 1 and 2 in chloroform and dimethylsulfoxide reveals that the acyclic peptide is conformationally labile. Evidence for a 3(10)-helical conformation in CDCl3 is obtained from sensitivity of NH chemical shifts to temperature and solvent perturbation and low JHNC alpha H values. Studies in solvent mixtures establish a conformational transition on going from CDCl3 to (CD3)2SO. The changes in NH nmr parameters, together with the observation of several interresidue C alpha i H-Ni+1H nuclear Overhauser effects support a conformation having a central beta-turn with extended arms in (CD3)2SO. A single Aib residue appears to stabilize a helix in apolar solvents, for the acyclic hexapeptide, while the disulfide bridge serves to lock the beta-hairpin conformation.

  12. 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...

  13. 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...

  14. Modeling and experimental testing of a smart composite bridge

    NASA Astrophysics Data System (ADS)

    Chandrashekhara, K.; Nanni, Antonio; Watkins, Steve E.; Kumar, Prakash

    2003-10-01

    An all composite bridge with integral sensor network has been designed and built at the University of Missouri-Rolla (UMR). An extensive experimental study and finite element analysis were carried out to obtain and compare properties (stiffness, strength, failure modes) of 76 mm (3 in) square hollow pultruded Fiber Reinforced Polymer (FRP) tubes and their assemblies. Tube assemblies were used in the fabrication of bridge deck designed for H-20 truckloads as specified by the American Association of State Highway and Transportation Officials (AASHTO). The bridge is 9.14 m (30 ft) long and is 2.74 m (9 ft) wide. All the coupons were tested under three- or four-point bending. Experimental results show excellent linear elastic behavior up to failure and are in good agreement with finite element solutions. A quarter portion of the full-sized bridge deck was then tested for its structural performance under design and fatigue loading and also for ultimate load capacity to evaluate the bridge response. The characteristics of the full-size bridge deck were determined by analyzing the performed tests. The test sample showed almost no reduction in stiffness or strength after 2 million cycles of fatigue loading in excess of the design load. The bridge was installed at the UMR campus in July 2000. The bridge is equipped with fiber optic sensors, and the response of the bridge will be remotely monitored.

  15. Strategic sensor locations of FPR bridge decks

    NASA Astrophysics Data System (ADS)

    Wu, Hwai-Chung; Warnemuende, Kraig; Yan, An; Mu, Bin

    2003-07-01

    Advanced fiber-reinforced polymer composite (FRP) has been increasingly used in bridge deck to replace concrete or steel. A FRP bridge deck can be designed to meet AASHTO HS-25 load requirements. FRP decks have many advantages over the conventional reinforced concrete or steel decks owing to their lightweight, high strength and corrosion resistance. However, such new deck system requires extensive monitoring to ensure its designed performance before its widespread acceptance by the bridge community. For inspection and evaluation purpose, a proper monitoring system consisting of various kinds of sensors installed in the FRP deck is critical. This paper provides a framework for designing an efficient monitoring system. The strategic sensor locations are identified based on the stress analysis of the FRP deck.

  16. 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

  17. VIEW OF BRIDGE, LOOKING SOUTHWEST, WITH SOUTHERN PACIFIC RAILROAD BRIDGE ...

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

    VIEW OF BRIDGE, LOOKING SOUTHWEST, WITH SOUTHERN PACIFIC RAILROAD BRIDGE IN BACKGROUND. THE PAVEMENT OF THE NORTH APPROACH IS SEEN BURIED ON THE RIGHT. ROADWAY (CENTER) CROSSES THE USUALLY DRY CHANNEL OF THE SALT RIVER. A BALUSTRADE OF THE MILL AVENUE BRIDGE IS SEEN AT THE LOWER LEFT CORNER - Ash Avenue Bridge, Spanning Salt River at Foot of Ash Avenue, Tempe, Maricopa County, AZ

  18. 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…

  19. Multivariate Feature Selection for Predicting Scour-Related Bridge Damage using a Genetic Algorithm

    NASA Astrophysics Data System (ADS)

    Anderson, I.

    2015-12-01

    Scour and hydraulic damage are the most common cause of bridge failure, reported to be responsible for over 60% of bridge failure nationwide. Scour is a complex process, and is likely an epistatic function of both bridge and stream conditions that are both stationary and in dynamic flux. Bridge inspections, conducted regularly on bridges nationwide, rate bridge health assuming a static stream condition, and typically do not include dynamically changing geomorphological adjustments. The Vermont Agency of Natural Resources stream geomorphic assessment data could add value into the current bridge inspection and scour design. The 2011 bridge damage from Tropical Storm Irene served as a case study for feature selection to improve bridge scour damage prediction in extreme events. The bridge inspection (with over 200 features on more than 300 damaged and 2,000 non-damaged bridges), and the stream geomorphic assessment (with over 300 features on more than 5000 stream reaches) constitute "Big Data", and together have the potential to generate large numbers of combined features ("epistatic relationships") that might better predict scour-related bridge damage. The potential combined features pose significant computational challenges for traditional statistical techniques (e.g., multivariate logistic regression). This study uses a genetic algorithm to perform a search of the multivariate feature space to identify epistatic relationships that are indicative of bridge scour damage. The combined features identified could be used to improve bridge scour design, and to better monitor and rate bridge scour vulnerability.

  20. Simple model of cable-stayed bridge deck subjected to static wind loading

    NASA Astrophysics Data System (ADS)

    Kang, Yi-Lung; Wang, Yang Cheng

    1997-05-01

    Cable-stayed bridges have been known since 18th century with aesthetics design. The structural system and the structural behavior are significantly different from those of continuous bridges. Compared to continuous bridge, cable- stayed bridges have more flexure bridge deck than those of continuous bridges.On the other hand, cable-stayed bridges have less stiffness to resist wind loading especially for lateral loads. The first considering of bridge engineering is safety. In 1940's, Tacoma Narrows Suspension Bridge destroyed by wind loading is a good example even though it is not a cable-stayed bridge. After the bridge was destroyed, a lot of research articles have been published regarding cable supported bridge subjected to wind loading. In recent days, high strength materials have been served. The bridge engineers use the advantages to expand the span length of cable-stayed bridges. Due to the span length increased and the use of high strength materials, cable- stayed bridges have more significant nonlinear behavior subjected to wind loading. In this paper, a slice bridge deck of cable-stayed bridge connected to internal support cables is considered. The deck has been considered to be subjected to lateral static wind loading. Since cables can not take compressive force, the deck has strongly nonlinear behavior even though the materials are linear elastic. Several primary load combinations have ben considered in this paper such as the bridge deck supposed to be moved horizontally without rotation or the bridge deck supposed to be moved horizontally with rotational deformation. The mathematical formulas and the numerical solutions are found and represented in graphical forms. The results can be provided to bridge designers and researchers for further study of this type of structure subjected to wind loading.

  1. 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)

  2. 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.

  3. HERO resistant semiconductor bridge igniter

    NASA Astrophysics Data System (ADS)

    Bickes, R. W., Jr.; Greenway, D.; Grubelich, M. C.; Meyer, W. J.; Hartman, J. K.; McCampbell, C. B.

    1992-10-01

    The problem of accidental ignition of explosive components when exposed to radio frequency (RF) environments or radiation from other electromagnetic sources is commonly referred to as Hazards of Electromagnetic Radiation to Ordnance (HERO). One illustration of such a HERO problem is the MK 149 Phalanx ammunition, which is sensitive to RF energy over a broad range of frequencies. We have demonstrated that a potential solution to the Phalanx HERO problem consists of a semiconductor bridge (SCB) igniter that incorporates microcircuitry to protect the SCB from the RF environment. Direct RF injection and ground plane tests have demonstrated the resistance of our designs to severe RF environments.

  4. 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…

  5. 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.

  6. Theoretical mechanics: Crowd synchrony on the Millennium Bridge

    NASA Astrophysics Data System (ADS)

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

    2005-11-01

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

  7. 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…

  8. The Learning Research Cycle: Bridging Research and Practice

    ERIC Educational Resources Information Center

    Stuessy, Carol L.; Metty, Jane S.

    2007-01-01

    A science teacher and her mentor reflect on their participation in the Learning Research Cycle, a professional learning model that bridges research and practice in both university and public school contexts. Teachers do scientific research in scientists' laboratories, then bridge their scientific experiences with the design of new classroom…

  9. 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…

  10. 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

  11. 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.

  12. 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…

  13. SOLERAS - Solar Energy Water Desalination Project: Chicago Bridge and Iron Company. Final report: system design extension. Volume 2. Appendices and drawings

    SciTech Connect

    Not Available

    1985-01-01

    The report concerns the design of a solar energy powered, seawater desalination pilot plant for installation at Yanbu, Saudi Arabia, on the shore of the Red Sea. General specifications, major equipment specifications, vendor and operation and maintenance information, as well as design drawings, are presented.

  14. 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.

  15. 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.

  16. Planar Hall effect bridge magnetic field sensors

    NASA Astrophysics Data System (ADS)

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

    2010-07-01

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

  17. 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

  18. 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

  19. Shoreham Railroad Bridge, Title Sheet Shoreham Railroad Bridge, Former ...

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

    Shoreham Railroad Bridge, Title Sheet - 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

  20. 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

  1. 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

  2. 23 CFR 972.210 - Federal lands bridge management system (BMS).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... CFR 650, subpart C, National Bridge Inspection Standards (NBIS). (b) The BMS shall be designed to fit.../replacement and estimated costs, prediction of the estimated remaining life of the bridge, development of a... 23 Highways 1 2010-04-01 2010-04-01 false Federal lands bridge management system (BMS)....

  3. 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

  4. 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

  5. Dynamics and statics of nonaxisymmetric liquid bridges

    NASA Astrophysics Data System (ADS)

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

    1994-11-01

    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.

  6. 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.

  7. 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.

  8. 1. WESTERN VIEW OF BRIDGE PLAZA, SHOWING MEMORIAL BRIDGE AT ...

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

    1. WESTERN VIEW OF BRIDGE PLAZA, SHOWING MEMORIAL BRIDGE AT LEFT AND THE ROCK CREEK AND POTOMAC PARKWAY RAMP AT RIGHT. VIEW TAKEN FROM THE REAR OF THE LINCOLN MEMORIAL. - Arlington Memorial Bridge, Boundary Channel Extension, Spanning Mount Vernon Memorial Highway & Boundary Channel, Washington, District of Columbia, DC

  9. Bridge Types: Suspension Bridge Spans, Section AA; Cantilever Truss Spans, ...

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

    Bridge Types: Suspension Bridge Spans, Section A-A; Cantilever Truss Spans, Section B-B; Through Truss Spans, Section C-C; Deck Truss Spans, Section D-D - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  10. 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...

  11. 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)

  12. 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 standards. (CMK)

  13. 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…

  14. 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…

  15. 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,…

  16. Bridging the Gap.

    ERIC Educational Resources Information Center

    Kroto, Joseph J.

    1988-01-01

    Describes interdisciplinary activities with real-world applications ranging from science to mathematics to technology. Cites the study and construction of model bridges as a way for students to learn about engineering concepts and some of their relationships. States that the exercise enhanced teacher cooperation between the different fields. (RT)

  17. 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…

  18. Bridging the Gaps.

    ERIC Educational Resources Information Center

    Netzer, Greg

    1995-01-01

    Discusses a model water quality monitoring project, Project Bridge, established to train minority girls about to enter eighth grade in scientific procedures followed by hands-on experimentation. Students spent a week monitoring water in an urban stream and analyzing results. (LZ)

  19. 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…

  20. Construction of a novel redox protein by rational design: conversion of a disulfide bridge into a mononuclear iron-sulfur center.

    PubMed

    Benson, D E; Wisz, M S; Liu, W; Hellinga, H W

    1998-05-19

    A mononuclear iron-sulfur center, capable of reversible electron transfer, has been introduced into thioredoxin, a protein devoid of such sites, using an automated, structure-based design algorithm. One of the sites predicted by the Dezymer computer program to introduce a tetrahedral tetrathiolate iron center included the intrinsic Cys32-Cys35 disulfide of wild-type thioredoxin and two additional mutants, Trp28Cys and Ile75Cys, thereby converting a disulfide into a metal-based redox center. This designed protein forms a 1:1 monomeric complex with FeIII, whose electronic absorption and EPR spectra closely resemble those of the rubredoxins, as intended. CoII spectra provided further confirmation of tetrahedral tetrathiolate metal coordination. The designed protein is capable of undergoing successive cycles of oxidation and reduction. The computer-generated design only took into account the geometry of the primary coordination shell around the metal. We have therefore demonstrated that simple geometrical considerations can be sufficient to reproduce the dominant electronic structure and reactivity of a simple metal-based redox center.

  1. "Turn-On" Fluorescent Probe for Mercury(II): High Selectivity and Sensitivity and New Design Approach by the Adjustment of the π-Bridge.

    PubMed

    Ding, Jun; Li, Huiyang; Wang, Can; Yang, Jie; Xie, Yujun; Peng, Qian; Li, Qianqian; Li, Zhen

    2015-06-01

    By intelligent design, a new "turn-on" fluorescent probe (1-CN) was obtained based on the deprotection reaction of the dithioacetal promoted by Hg2+ ions, which could sense mercury ions sensitively and selectively, with the detection limit of 8×10(-7) M. Thanks to the apparent turn-on signal, 1-CN has been successfully applied to rapidly detect trace amounts of mercury ions as test strips and cell image.

  2. Automatic Linearity Calibration in a Resistance Thermometry Bridge

    NASA Astrophysics Data System (ADS)

    Walker, R.

    2011-01-01

    The paper describes a new system that automatically calibrates the linearity of a resistance thermometry bridge or readout. A thermometry bridge, like all measuring and test equipment, must be regularly tested to ensure it is operating properly and accurately. Previously, this could only be done using special equipment and time-consuming procedures. The new technique described in the paper facilitates more frequent calibration of a resistance thermometry bridge. The system is incorporated into the design of the bridge and thus requires no extra equipment. Calibration, once initiated, is performed automatically by the bridge and is relatively fast. Tests were performed to evaluate the effectiveness of the automatic linearity calibration method. The uncertainty analysis and test results presented in the paper indicate that the technique is capable of quantifying resistance ratio measurement error as small as 2 × 10-8 and is effective at identifying a wide variety of failures when they occur.

  3. Monorail bridge conveyor. Phase I report, March 31, 1980

    SciTech Connect

    Silks, W.

    1980-03-01

    This report covers the first 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 I covers the final design. 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 must be such that each bridge is self propelled in order to minimize side loading on the monorail. The conveyor belt drive could be simplified since it only had to drive one single 24 ft. conveyor. The design and detail drawings including MSHA approved enclosures were completed and are ready to be released for Phase II, Fabrication.

  4. Monorail bridge conveyor. Phase I report, March 31, 1980

    SciTech Connect

    Silks, W.

    1980-03-01

    This report covers the first 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 I covers the final design. 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 must be such that each bridge is self propelled in order to minimize side loading on the monorail. The conveyor belt drive could be simplified since it only had to drive one single 24 ft conveyor. The design and detail drawings including MSHA approved enclosures were completed and are ready to be released for Phase II, Fabrication.

  5. Bridged ferrocenes. 10. Structural phenomena

    SciTech Connect

    Hillman, M.; Fujita, E.; Dauplaise, H.; Kvick, A.; Kerber, R.C.

    1984-01-01

    The structures of 1,1',2,2'-bis(tetramethylene)ferrocene, I, 1,1',2,2',4,4'-tris(tetramethylene)ferrocene, II, and 1,1',2,2',4,4'-tris(pentamethylene)ferrocene, III, are given and are compared to the previously determined structure of 1,1',2,2',4,4'-tris(trimethylene)ferrocene, IV. The iron-to-ring distances are consistent with the reported Moessbauer spectra and redox potentials. The cyclopentadienyl rings are eclipsed in the compounds with trimethylene and pentamethylene bridges but are staggered by 12-14 in the compounds with tetramethylene bridges. In compounds with tetra- and pentamethylene bridges the presence of staggering or eclipsing is attributed to the need to avoid eclipsing of the protons in the bridges. In the compound with three trimethylene bridges, the shortness of the bridges is of primary importance. The staggered conformation observed in I and II may be the source of the apparent anomalies observed in the ring-proton region of the NMR spectra of bridged ferrocenes. The bridge-proton region of the NMR spectra at 360 MHz are given for I and other bridged ferrocenes. Disorder of the bridge carbons observed in the crystals are correlated with the flipping of the bridges observed in the NMR spectra. 30 references, 8 tables.

  6. 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.

  7. Molecular engineering with bridged polysilsesquioxanes

    SciTech Connect

    LOY,DOUGLAS A.; SHEA,KENNETH J.

    2000-05-09

    Bridged polysilsesquioxanes are a class of hybrid organic-inorganic materials that permit molecular engineering of bulk properties including porosity. Prepared by sol-gel polymerization of monomers with two or more trialkoxysilyl groups, the materials are highly cross-linked amorphous polymers that are readily obtained as gels. The bridging configuration of the hydrocarbon group insures that network polymers are readily formed and that the organic functionality is homogeneously distributed throughout the polymeric scaffolding at the molecular level. This permits the bulk properties, including surface area, pore size, and dielectric constant to be engineered through the selection of the bridging organic group. Numerous bridging groups have been incorporated. This presentation will focus on the effects that the length, flexibility, and substitution geometry of the hydrocarbon bridging groups have on the properties of the resulting bridged polysilsesquioxanes. Details of the preparation, characterization, and some structure property relationships of these bridged polysilsesquioxanes will be given.

  8. 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.

  9. 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

  10. 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

  11. 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. PMID:26463562

  12. 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.

  13. Characterization and electrical modeling of semiconductors bridges

    SciTech Connect

    Marx, K.D.; Bickes, R.W. Jr.; Wackerbarth, D.E.

    1997-03-01

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

  14. 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.

  15. 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.

  16. Foundation Depth for Bridge Piers

    NASA Astrophysics Data System (ADS)

    Veerappadevaru, G.; Gangadharaiah, T.; Jagadeesh, T. R.

    2013-09-01

    The safety of bridge piers built in rivers having the bed is one of the prime aspects in the study of scouring process around bridge piers. The stability of bridge piers depends on the depth of foundation provided below maximum scour level. The stability analysis of bridge piers is carried based on moment of forces acting on the caisson pier when the pier slides and tilts slightly in downstream from its position. The experiments are conducted for three pier shapes on two sediment beds and for different flow conditions. The curves indicating the stability limits are compared with Lacey's recommendations which are used in present day practice in India. The analysis presented here indicates that the Lacey's recommendation for railway bridges is safe and for some cases of the road bridges depends on grip length, angle of tilt and weight of caisson.

  17. 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.

  18. Bridging the Gap.

    PubMed

    Webb, Michele

    2016-01-01

    The view from the top of Hoover Dam looking south over the Colorado River was breathtaking! My friend and I stood there in silence, taking it all in. I had visited Hoover Dam on many occasions, but this visit was the first time I had seen the arch bridge that carries US Route 93 over the river and joins Nevada and Arizona states. It was a beautiful day, the temperature was perfect, and there was a slight breeze coming from Lake Mead behind us as we took in the view. PMID:27556855

  19. Nasal Bridge Intramuscular Hemangioma

    PubMed Central

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

    2015-01-01

    Intramuscular haemangioma (IMH) is a benign mesenchymal tumour. It appears as a deep, nontender mass within the soft tissue, particularly in the extremities. This tumour may not be obvious on clinical examination. Head and neck IMHs represent only 13.5% of the total IMHs. The most common site for a head and neck IMH is the masseter muscle, followed by trapezius, sternocleidomastoid, and very rarely temporalis muscle. We present a patient with left nasal bridge swelling which was excised and histologically confirmed as intramuscular hemangioma. PMID:25709848

  20. 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

  1. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 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 BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.40 Bridge repairs. Repairs to a bridge which...

  2. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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 BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.40 Bridge repairs. Repairs to a bridge which...

  3. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 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 BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.40 Bridge repairs. Repairs to a bridge which...

  4. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 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 BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.40 Bridge repairs. Repairs to a bridge which...

  5. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 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 BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.40 Bridge repairs. Repairs to a bridge which...

  6. 16. Little Hell Gate Bridge with Big Hell Gate Bridge ...

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

    16. Little Hell Gate Bridge with Big Hell Gate Bridge in background. Wards Island, New York Co., NY. Sec. 4207, MP 8.02. - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York County, NY

  7. 20. Bronx Kill Bridge with Hell Gate Bridge in background. ...

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

    20. Bronx Kill Bridge with Hell Gate Bridge in background. Randalls Island, New York Co., NY. Sec. 4207, MP 8.54. - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York County, NY

  8. 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

  9. 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

  10. 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.

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  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, 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...

  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, 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...

  19. 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...

  20. 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...

  1. 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.

  2. 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. PMID:16875244

  3. 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)

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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. PMID:24489496

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Bridge SHM system based on fiber optical sensing technology

    NASA Astrophysics Data System (ADS)

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

    2015-09-01

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

  14. 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…

  15. 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…

  16. 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.

  17. 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.

  18. 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.

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

    NASA Astrophysics Data System (ADS)

    Liu, Jun

    2009-10-01

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

  20. Rational design of azide-bridged bimetallic complexes. Crystal structure and magnetic properties of Fe(III)MFe(III) (M = Ni(II) and Cu(II)) trinuclear species.

    PubMed

    Colacio, Enrique; Costes, Jean-Pierre; Domínguez-Vera, José M; Maimoun, Ikram Ben; Suárez-Varela, José

    2005-01-28

    The first examples of azide-bridged bimetallic trinuclear complexes ([M(cyclam)][FeL(N3)(mu1,5-N3)]2) (H2L = 4,5-dichloro-1,2-bis(pyridine-2-carboxamido) benzene) have been structurally and magnetically characterized.

  1. 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.

  2. 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...

  3. Bridge diagnosis at 55 mph

    SciTech Connect

    Azevedo, S

    1998-10-01

    The Federal Highway Administration (FHWA) has helped sponsor a research project at Lawrence Livermore that produced a beneficial new tool as well as an R&D 100 Award. The HERMES Bridge Inspector will provide an invaluable capability to diagnose the problems of deteriorating bridge decks and do it accurately, efficiently, nondestructively, and, perhaps most important to motorists, without closing bridges. Almost 30% of 600,000 large highway bridges in the U.S. are classified "deficient" by the FHWA, and HERMES can make a significant contribution toward solving the problem of infrastructure assessment and repair. With further development, HERMES holds promise for other concrete inspection problems, such as railroads, tunnels, and runways. HERMES, or High-performance Electromagnetic Roadway Mapping and Evaluation System, is a radar-based sensing system mounted in a trailer. It can be pulled by a vehicle at traffic speeds over a bridge deck to collect information about the roadway subsurface -- its sensors gathering data 30 centimeters or more into concrete. An onboard computer system processes the data into three-dimensional images that pinpoint problems in the roadway concrete and give engineers quantitative information about deterioration in the bridge deck. Engineers can then better assess what repairs or reconstruction is necessary and avoid the cost overruns and delays that result from inexact problem diagnoses.

  4. 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

  5. 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.

  6. 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.

  7. Economic Functions Proposal of Urgency Prioritization of Investment Projects of Operated Railway Bridges

    NASA Astrophysics Data System (ADS)

    Pitoňák, Martin

    2014-12-01

    The main objective of the article is to describe the proposals of economic functions within the prioritization of urgency investments of operated railway bridges within a comprehensive evaluation of existing bridges. The purpose of the paper is a comprehensive assessment of existing bridges and to define determinants and determinants of decision-making and designing a mechanism of decision-making procedures of prioritized infrastructure measures in the form of repairs and reconstructions of bridges resulting from the records of supervising activities based not only on technical but also economic aspects to the railway infrastructure manager.

  8. 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…

  9. 23 CFR 972.210 - Federal lands bridge management system (BMS).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... CFR 650, subpart C, National Bridge Inspection Standards (NBIS). (b) The BMS shall be designed to fit... include: (i) The inventory data required by the NBIS (23 CFR 650, subpart C); (ii) Data characterizing the... 23 Highways 1 2014-04-01 2014-04-01 false Federal lands bridge management system (BMS)....

  10. 23 CFR 972.210 - Federal lands bridge management system (BMS).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... CFR 650, subpart C, National Bridge Inspection Standards (NBIS). (b) The BMS shall be designed to fit... include: (i) The inventory data required by the NBIS (23 CFR 650, subpart C); (ii) Data characterizing the... 23 Highways 1 2013-04-01 2013-04-01 false Federal lands bridge management system (BMS)....

  11. 23 CFR 972.210 - Federal lands bridge management system (BMS).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... CFR 650, subpart C, National Bridge Inspection Standards (NBIS). (b) The BMS shall be designed to fit... include: (i) The inventory data required by the NBIS (23 CFR 650, subpart C); (ii) Data characterizing the... 23 Highways 1 2011-04-01 2011-04-01 false Federal lands bridge management system (BMS)....

  12. Linking Flood-Related Damage to Bridges and Stream Geomorphic Conditions in Vermont

    NASA Astrophysics Data System (ADS)

    Anderson, I.; Dewoolkar, M.; Rizzo, D.; Huston, D.

    2014-12-01

    Bridge scour design predicts the depth of erosion given conditions of the streambed, geometry and flow. The depth of the scour hole is calculated empirically, while the width is assumed to be a percentage of the estimated depth. In Vermont, bridge damage resulting from the 2011 Tropical Storm Irene showed high numbers of stream widening and outflanking at bridges rather than vertical scour holes. The outflanking of bridges is not represented in current bridge scour design, where riprap is typically recommended to prevent horizontal stream migration. This study evaluates whether stream geomorphic information can be used to determine conditions that resulted in outflanking. Post flood inspection photographs are reviewed to identify cases of outflanking, and data from the National Bridge Inventory (NBI) and the Vermont Agency of Natural Resources' (VTANR) Rapid Geomorphic Assessment (RGA) are used to determine the specific site and stream characteristics at the bridges. When applicable, bridge design plans and HEC-RAS modeling are used to compare scour depth calculations to evidence of damage from site photographs. Geomorphic assessments are used to determine if there are site differences that resulted in outflanking rather than traditional vertical scour. The damage from outflanking erosion can be quantified and modeled similar to the process of calculating scour depths, aiding in the prediction of outflanking, and improving the ability to design against it.

  13. 33 CFR 165.1110 - Security Zone: Coronado Bay Bridge, San Diego, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Bridge, San Diego, CA. 165.1110 Section 165.1110 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 165.1110 Security Zone: Coronado Bay Bridge, San Diego, CA. (a) Location. All navigable waters of San... from Captain of the Port or his designated representative. The Coast Guard can be contacted on...

  14. 33 CFR 165.1110 - Security Zone: Coronado Bay Bridge, San Diego, CA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Bridge, San Diego, CA. 165.1110 Section 165.1110 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 165.1110 Security Zone: Coronado Bay Bridge, San Diego, CA. (a) Location. All navigable waters of San... from Captain of the Port or his designated representative. The Coast Guard can be contacted on...

  15. 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.

  16. 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

  17. 26. NEW STEEL BRIDGE COMPLETED ASSEMBLED. OLD BRIDGE BELOW. U.S.G.S. ...

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

    26. NEW STEEL BRIDGE COMPLETED ASSEMBLED. OLD BRIDGE BELOW. U.S.G.S. GAGING STATION IN RIGHT BACKGROUND. VIEW LOOKING NORTHEAST - Kaibab Trail Suspension Bridge, Spanning Colorado River, Grand Canyon, Coconino County, AZ

  18. 49 CFR 237.101 - Scheduling of bridge inspections.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... bridge, and the weight and frequency of traffic carried on the bridge. (c) Each bridge management program... bridge inspections. (a) Each bridge management program shall include a provision for scheduling an... for in the bridge management program when a railroad bridge engineer determines that such...

  19. 49 CFR 237.101 - Scheduling of bridge inspections.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... bridge, and the weight and frequency of traffic carried on the bridge. (c) Each bridge management program... bridge inspections. (a) Each bridge management program shall include a provision for scheduling an... for in the bridge management program when a railroad bridge engineer determines that such...

  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... Safety Watches § 80.309 Watch required by the Bridge-to-Bridge Act. In addition to the watch requirement contained in § 80.148, all vessels subject to the Bridge-to-Bridge Act must keep a watch on the...

  1. 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... Safety Watches § 80.309 Watch required by the Bridge-to-Bridge Act. In addition to the watch requirement contained in § 80.148, all vessels subject to the Bridge-to-Bridge Act must keep a watch on the...

  2. 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... Safety Watches § 80.309 Watch required by the Bridge-to-Bridge Act. In addition to the watch requirement contained in § 80.148, all vessels subject to the Bridge-to-Bridge Act must keep a watch on the...

  3. 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... Safety Watches § 80.309 Watch required by the Bridge-to-Bridge Act. In addition to the watch requirement contained in § 80.148, all vessels subject to the Bridge-to-Bridge Act must keep a watch on the...

  4. 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... Safety Watches § 80.309 Watch required by the Bridge-to-Bridge Act. In addition to the watch requirement contained in § 80.148, all vessels subject to the Bridge-to-Bridge Act must keep a watch on the...

  5. Floating liquid bridge charge dynamics

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

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

  6. 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…

  7. 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…

  8. 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…

  9. Bridging Cultures. A Pre-Service Teacher Preparation Module.

    ERIC Educational Resources Information Center

    Rothstein-Fisch, Carrie

    This document summarizes Bridging Cultures, a 3-hour course module for preservice teachers that is designed to improve teachers' ability to successfully teach diverse students. It can be integrated into existing courses on child development, educational psychology, or the like. The module introduces a framework (based on the constructs of…

  10. High School Bridge Program: A Multidisciplinary STEM Research Program

    ERIC Educational Resources Information Center

    Zhe, Jiang; Doverspike, Dennis; Zhao, Julie; Lam, Paul; Menzemer, Craig

    2010-01-01

    A Science, Technology, Engineering and Math (STEM) summer Bridge Program was developed for high school students. The program was designed to encourage students to consider choosing an engineering major in college and to explore STEM as a future career. This was accomplished through a 10-week program involving multidisciplinary research activities.…

  11. 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

  12. 27. VIEW SHOWING SOUTH ELEVATION OF NOTRE DAM BRIDGE, LOOKING ...

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

    27. VIEW SHOWING SOUTH ELEVATION OF NOTRE DAM BRIDGE, LOOKING NORTHEAST Ernest Gould, photographer, 1987 - Notre Dame Bridge, Spanning Merrimack River on Bridge Street, Manchester, Hillsborough County, NH

  13. 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

  14. 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

  15. Monitoring the Dynamic Deformation of the Bridge Structures by Accelerometers

    NASA Astrophysics Data System (ADS)

    Lipták, Imrich

    2013-10-01

    The paper presents current trends in determining the dynamic deformations of bridge structures through the exploitation of geodetic measurements by accelerometers. The main aim of the paper is to demonstrate the practical application of these measurements on the cycling bridge over the river Morava in Devínska Nová Ves. Possibilities for the processing and analysis of accelerometer measurements by spectral analysis are described. An evaluation of the results is realized based on the modal characteristics from a numerical model designed by the finite element method.

  16. 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.

  17. Scour at a bridge over the Weldon River, Iowa

    USGS Publications Warehouse

    Fischer, Edward E.

    1993-01-01

    Contraction scour at the State Highway 2 bridge over the Weldon River in south-central Iowa was caused by a flood of record proportions on September 14 and 15, 1992. The peak discharge was 1, 930 cubic meters per second,which was 4 times the probable 100-year flood used to design the bridge, and resulted in road overflow. Contraction scour exposed the pier footings, but a subsurface layer of glacial clay apparently resisted additional vertical scour and caused the scouring process to move laterally. The embankment at the left abutment was eroded away, exposing 3 m of vertical abutment piling.

  18. 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.

  19. 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

  20. 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. PMID:25405232

  1. 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.

  2. 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.

  3. 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.

  4. 49 CFR 237.57 - Designations of individuals.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Designations of individuals. 237.57 Section 237.57... § 237.57 Designations of individuals. Each track owner shall designate those individuals qualified as railroad bridge engineers, railroad bridge inspectors and railroad bridge supervisors. Each...

  5. Tuning spin-spin coupling in quinonoid-bridged dicopper(II) complexes through rational bridge variation.

    PubMed

    Schweinfurth, David; Khusniyarov, Marat M; Bubrin, Denis; Hohloch, Stephan; Su, Cheng-Yong; Sarkar, Biprajit

    2013-09-16

    Bridged metal complexes [{Cu(tmpa)}2(μ-L(1)-2H)](ClO4)2 (1), [{Cu(tmpa)}2(μ-L(2)-2H)](ClO4)2 (2), [{Cu(tmpa)}2(μ-L(3)-2H)](BPh4)2 (3), and [{Cu(tmpa)}2(μ-L(4)-2H)](ClO4)2 (4) (tmpa = tris(2-pyridylmethyl)amine, L(1) = chloranilic acid, L(2) = 2,5-dihydroxy-1,4-benzoquinone, L(3) = (2,5-di-[2-(methoxy)-anilino]-1,4-benzoquinone, L(4) = azophenine) were synthesized from copper(II) salts, tmpa, and the bridging quinonoid ligands in the presence of a base. X-ray structural characterization of the complexes showed a distorted octahedral environment around the copper(II) centers for the complexes 1-3, the donors being the nitrogen atoms of tmpa, and the nitrogen or oxygen donors of the bridging quinones. In contrast, the copper(II) centers in 4 display a distorted square-pyramidal coordination, where one of the pyridine arms of each tmpa remains uncoordinated. Bond-length analyses within the bridging ligand exhibit localization of the double bonds inside the bridge for 1-3. In contrast, complete delocalization of double bonds within the bridging ligand is observed for 4. Temperature-dependent magnetic susceptibility measurements on the complexes reveal an antiferromagnetic coupling between the copper(II) ions. The strength of antiferromagnetic coupling was observed to depend on the energy of the HOMO of the bridging quinone ligands, with exchange coupling constants J in the range between -23.2 and -0.6 cm(-1) and the strength of antiferromagnetic coupling of 4 > 3 > 2 > 1. Broken-symmetry density functional theory calculations (DFT) revealed that the orientation of magnetic orbitals in 1 and 2 is different than that in 3 and 4, and this results in two different exchange pathways. These results demonstrate how bridge-mediated spin-spin coupling in quinone-bridged metal complexes can be strongly tuned by a rational design of the bridging ligand employing the [O] for [NR] isoelectronic analogy.

  6. 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.

  7. 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.

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

    NASA Astrophysics Data System (ADS)

    Gangopadhyay, Avijit; Ghosh, Aparna Dey

    2016-06-01

    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.

  9. 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.

  10. Preliminary study to facilitate smart structure systems in bridge girders

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, Thomas C.; Peterson, Danford O.; Rossi, Peter J.; Ray, Laura R.; Livingston, Richard A.

    1999-05-01

    Sensors are currently available and used to monitor structural performance and loads incurred by bridges already in service. However, there has been limited research concerning the stresses that steel bridge girders endure during transport from the manufacturer to the job site and during the installation process. This paper reports the measured stresses on steel bridge girders during transportation from Lancaster, PA to Hanover, NH and during construction of the Ledyard Bridge on the New Hampshire - Vermont border. Two different monitoring system were developed for this data acquisition in a mobile environment. The first, a fiber optic strain monitoring system, utilizing Bragg grating technology. The second utilized an electrical- resistive foil strain gage network, in conjunction with wireless telemetry equipment. Together, these two systems formed a smart structure system for monitoring bridge girders while confirming the accuracy of data gathered through redundancy. Result conclusively demonstrated for the first time, that stresses in beams during transportation are significant and approach the factor of safety margin in girder design.

  11. 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.

  12. 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.

  13. 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.

  14. Substructure Main Bridge, River Piers A & V ...

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

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

  15. 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...

  16. A semiconductor bridge ignited hot gas piston ejector

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    The topics are presented in viewgraph form and include the following: semiconductor bridge technology (SCB); SCB philosophy; technology transfer; simplified sketch of SCB; SCB processing; SCB design; SCB test assembly; 5 mJ SCB burst based on a polaroid photograph; micro-convective heat transfer hypothesis; SCB fire set; comparison of SCB and hot-wire actuators; satellite firing sets; logic fire set; SCB smart component; SCB smart firing set; semiconductor design considerations; and the adjustable actuator system.

  17. The Bridge School: A Profile.

    ERIC Educational Resources Information Center

    Sementelli, Catherine

    2001-01-01

    At the Bridge School (Hillsborough, California), children with severe speech and physical disabilities are trained in the use of augmentative and alternative communication technologies, transitioned back to their home school districts, and given continuing support. Outreach and research endeavors keep the broader community informed and educated…

  18. 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…

  19. Bridging Cultures with Classroom Strategies.

    ERIC Educational Resources Information Center

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

    1999-01-01

    Collectivism, stressing family members' interdependence, is common to Latino cultures. In contrast, schools foster independence and individual achievement. To help teachers understand assumptions underlying these different values, the authors developed the "Bridging Cultures Project" as a research-based professional-development program. Science…

  20. Over the Ramp: Building Bridges

    ERIC Educational Resources Information Center

    Sutton, Mary

    2007-01-01

    TheatreWorks is the third largest theatre in the San Francisco bay area. Through the usual educational programs that $6 million companies tend to offer, it has reached over 100,000 students of all ages in the past 8 years. The TheatreWorks Bridges Projects, however, are special. They are intricate and expansive, work with multiple community…

  1. 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.

  2. Evaluation of Summer Bridge Programs

    ERIC Educational Resources Information Center

    Garcia, Lisa D.; Paz, Chiara C.

    2009-01-01

    Many colleges and universities in the United States offer summer programs for their incoming students. While programs are structured and administered in a variety of ways and target various student populations, the most common type of summer bridge program aims to serve historically underrepresented students and students of low socioeconomic…

  3. 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

  4. 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

  5. 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

  6. 26. Ninth Melan Bridge on tour route, in southern area ...

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

    26. Ninth Melan Bridge on tour route, in southern area of park, looking to the SW back to eighth bridge. - Vicksburg National Military Park Roads & Bridges, Melan Arch Bridges, Spanning various tributaries at Confederate Avenue, Vicksburg, Warren County, MS

  7. 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…

  8. 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...

  9. 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

  10. 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

  11. Structural Bridges through Fold Space.

    PubMed

    Edwards, Hannah; Deane, Charlotte M

    2015-09-01

    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.

  12. 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…

  13. Remediation: Higher Education's Bridge to Nowhere

    ERIC Educational Resources Information Center

    Complete College America, 2012

    2012-01-01

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

  14. 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.

  15. Seismic enhancement of multi-span continuous bridges subjected to three-directional excitations

    NASA Astrophysics Data System (ADS)

    Aryan, H.; Ghassemieh, M.

    2015-04-01

    Considering the seismic ground motions as the excitations in only two principal horizontal directions of the bridges and ignoring the third vertical direction is a disregard for the seismic conditions of the region and the bridge distance from epicenter. Numerous cases of substantial damages have been reported among the bridges tremendously suffered from being exposed to the simultaneous three-directional seismic ground motions. Besides the significant compression and tension damages in the columns due to the presence of vertical excitation, it could lead to unexpected shear and flexural failures in the columns and other components as well. Because the axial force variation in the columns due to three-directional excitations, could affect the demands and capacities of the bridge’s components. With respect to this issue, several studies on the bridge damages during the earthquakes have urged researchers to offer efficient methods for bridges handling of the three-directional seismic excitations. Thus, this paper presents and evaluates a superelastic based system for designing as well as retrofitting the multi-span continuous (MSC) bridges that can cope with two- and three-directional seismic excitations. Efficiency evaluation of the proposed system is conducted through various nonlinear time history analyses on a three-dimensional model of a detailed MSC bridge using a suite of developed ground motions for the bridge region. Also, all the analyses are fulfilled based on variation of one influential design characteristic of the proposed system in order to achieve the optimal design. Several pertinent assessment parameters are used during the evaluation of the proposed system. Finally, the efficiency of the new system subjected to the vertical and horizontal seismic excitations is confirmed according to reduction of the bridge responses and improvement in nonlinear performance of the columns in comparison with the as-built bridge results.

  16. 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

  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, 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...

  19. 49 CFR 237.109 - Bridge inspection records.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 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...

  20. 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...

  1. 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...

  2. 49 CFR 237.109 - Bridge inspection records.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 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...

  3. 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...

  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. 33 CFR 118.100 - Retroreflective panels on bridge piers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 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...

  7. 33 CFR 118.100 - Retroreflective panels on bridge piers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 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...

  8. 49 CFR 237.109 - Bridge inspection records.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 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...

  9. 49 CFR 237.111 - Review of bridge inspection reports.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 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...

  10. 49 CFR 237.109 - Bridge inspection records.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 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...

  11. Nonlinear dynamic responses of suspension bridge to sudden breakage of hangers

    NASA Astrophysics Data System (ADS)

    Qiu, W. L.; Jiang, M.; Zhang, Z.

    2015-07-01

    It is found that the hangers in many suspension bridges in China faced serious corrosion. The resistance capacities of the hangers decrease for corrosion, and the corroded hangers may break suddenly under tension forces. The sudden breakage of a hanger can induce violent vibrations and large changes of internal forces of the whole bridge. The safety of suspension bridges is endangered by corrosion of hangers. Using nonlinear dynamic analysis method and adopting 3D finite element model, the nonlinear dynamic responses of an actual suspension bridge to sudden breakage of a hanger are studied in this paper. The influences of sudden breakage of hanger on the bridge are analyzed in detail. Based on the analysis results, some useful suggestions about design and maintain of hangers are proposed.

  12. Cross-bridge elasticity in single smooth muscle cells

    PubMed Central

    1983-01-01

    In smooth muscle, a cross-bridge mechanism is believed to be responsible for active force generation and fiber shortening. In the present studies, the viscoelastic and kinetic properties of the cross- bridge were probed by eliciting tension transients in response to small, rapid, step length changes (delta L = 0.3-1.0% Lcell in 2 ms). Tension transients were obtained in a single smooth muscle cell isolated from the toad (Bufo marinus) stomach muscularis, which was tied between a force transducer and a displacement device. To record the transients, which were of extremely small magnitude (0.1 microN), a high-frequency (400 Hz), ultrasensitive force transducer (18 mV/microN) was designed and built. The transients obtained during maximal force generation (Fmax = 2.26 microN) were characterized by a linear elastic response (Emax = 1.26 X 10(4) mN/mm2) coincident with the length step, which was followed by a biphasic tension recovery made up of two exponentials (tau fast = 5-20 ms, tau slow = 50-300 ms). During the development of force upon activation, transients were elicited. The relationship between stiffness and force was linear, which suggests that the transients originate within the cross-bridge and reflect the cross-bridge's viscoelastic and kinetic properties. The observed fiber elasticity suggests that the smooth muscle cross-bridge is considerably more compliant than in fast striated muscle. A thermodynamic model is presented that allows for an analysis of the factors contributing to the increased compliance of the smooth muscle cross-bridge. PMID:6413640

  13. 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.

  14. Bridging Research and Practice

    PubMed Central

    Tabak, Rachel G.; Khoong, Elaine C.; Chambers, David; Brownson, Ross C.

    2013-01-01

    Context Theories and frameworks (hereafter called models) enhance dissemination and implementation (D&I) research by making the spread of evidence-based interventions more likely. This work organizes and synthesizes these models by: (1) developing an inventory of models used in D&I research; (2) synthesizing this information; and (3) providing guidance on how to select a model to inform study design and execution. Evidence acquisition This review began with commonly cited models and model developers and used snowball sampling to collect models developed in any year from journal articles, presentations, and books. All models were analyzed and categorized in 2011 based on three author-defined variables: construct flexibility, focus on dissemination and/or implementation activities (D/I), and the socio-ecological framework (SEF) level. Five-point scales were used to rate construct flexibility from broad to operational and D/I activities from dissemination-focused to implementation-focused. All SEF levels (system, community, organization, and individual) applicable to a model were also extracted. Models that addressed policy activities were noted. Evidence synthesis Sixty-one models were included in this review. Each of the five categories in the construct flexibility and D/I scales had/contained at least four models. Models were distributed across all levels of the SEF; the fewest models (n=8) addressed policy activities. To assist researchers in selecting and utilizing a model throughout the research process, the authors present and explain examples of how models have been used. Conclusions These findings may enable researchers to better identify and select models to inform their D&I work. PMID:22898128

  15. 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.

  16. Full-bridge capacitive extensometer

    NASA Astrophysics Data System (ADS)

    Peters, Randall D.

    1993-08-01

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

  17. New bridge plug and retrieving tool that aids completion of geothermal steam wells

    SciTech Connect

    Harris, A.; Thompson, P.; Ash, D.

    1981-01-01

    A typical completion procedure requires placement of a bridge plug near the liner top of a producing steam well so the well can be loaded to permit cementing of the tieback casing string by conventional cementing techniques. A drillable bridge plug has been used in the past so that it could be removed with a conventional toothed, cone-type drill bit. All components could not be drilled out because the bridge plug would separate from the casing when drilling through its top slips. This created a hazardous situation because heavy components remaining in the well could blowout after placing the well into production and damage or destroy surface equipment. A bridge plug and its companion milling-type retrieving tool were developed to perform the bridging operation and accomplish removal in a producing geothermal steam well environment. The bridge plug features an internal bridging plug that is designed to permit the release of differential pressure buildup from below before releasing the bridge plug by milling away the top slips. The milling-type retrieving tool has a catcher mechanism designed to function in the high-velocity steam flow of a producing well to catch the released bridge plug. After the released bridge plug components are caught, they may be returned to the surface in a controlled manner. This removes the massive components so that they will not be blown out by the steam of a producing well. Field use has demonstrated that this equipment is a practical completion aid, and it is currently being used in The Geysers field of northern California. Examples of field usage are discussed in the paper.

  18. Parabolic metamaterials and Dirac bridges

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

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

  19. 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.

  20. 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.

  1. Bridging Media with the Help of Players

    NASA Astrophysics Data System (ADS)

    Nitsche, Michael; Drake, Matthew; Murray, Janet

    We suggest harvesting the power of multiplayer design to bridge content across different media platforms and develop player-driven cross-media experiences. This paper first argues to partially replace complex AI systems with multiplayer design strategies to provide the necessary level of flexibility in the content generation for cross-media applications. The second part describes one example project - the Next Generation Play (NGP) project - that illustrates one practical approach of such a player-driven cross-media content generation. NGP allows players to collect virtual items while watching a TV show. These items are re-used in a multiplayer casual game that automatically generates new game worlds based on the various collections of active players joining a game session. While the TV experience is designed for the single big screen, the game executes on multiple mobile phones. Design and technical implementation of the prototype are explained in more detail to clarify how players carry elements of television narratives into a non-linear handheld gaming experience. The system describes a practical way to create casual game adaptations based on players' personal preferences in a multi-user environment.

  2. Nondestructive evaluation techniques for enhanced bridge inspection

    SciTech Connect

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

    1993-10-01

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

  3. 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…

  4. 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…

  5. 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…

  6. Fiber optic corrosion sensing for bridges and roadway surfaces

    NASA Astrophysics Data System (ADS)

    Fuhr, Peter L.; Ambrose, Timothy P.; Huston, Dryver R.; McPadden, Adam P.

    1995-04-01

    In this paper we report the development of a fiber optic corrosion sensing system that complements and/or surpasses the capabilities of conventional corrosion sensing techniques. The sensing system is based on evanescent wave phenomena and in the configured sensor allows for the detection of general corrosion on and within materials. Based on the authors' experience installing may kilometers of fiberoptic sensors into large civil structures such as multistory buildings, hydroelectric dams, and railway/roadway bridges, we are (currently) embedding these sensors into bridge test members -- limited structures that are being subjected to accelerated corrosion testing conditions. Three Vermont Agency of Transportation bridges, one in a low salt use region, one in a medium salt use region, and the third in a high salt use region, are being selected and will be instrumented with these embedded fiber optic corrosion sensors. Monitoring of chloride penetration and rebar corrosion status will be measured during the course of a longitudinal study. The specific sensing mechanism and design for robustness (to allow survival of the embedding process during repaving of the bridges) are discussed and laboratory and initial field results are presented.

  7. 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.

  8. 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.

  9. Asymmetric Switching For A PWM H-Bridge Power Circuit

    NASA Technical Reports Server (NTRS)

    Wong, See-Pok

    1995-01-01

    Only two of four switches interrupt substantial current. An asymmetric timing scheme improves design and operation of pulse-width-modulation (PWM) H-bridge switch-and-transformer circuit. Circuit part of dc-to-dc converter or dc-to-ac inverter; in either case, output current or voltage regulated by adjusting times of opening and closing of semiconductor switches 1 through 4 to adjust durations of current pulses in primary winding of transformer.

  10. BNCP prototype detonator studies using a semiconductor bridge initiator

    SciTech Connect

    Fyfe, D.W.; Fronabarger, J.W.; Bickes, R.W. Jr.

    1994-06-01

    We report on experiments with prototype BNCP detonators incorporating a semiconductor bridge, SCB. We tested two device designs; one for DoD and one for DOE applications. We report tests with the DoD detonator using different firing conditions and two different grain sizes of BNCP. The DOE detonator utilized a 50 {mu}F CDU firing set with a 24 V all-fire condition.

  11. 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.

  12. Quantum Bridge Fabrication Using Photolithography

    SciTech Connect

    Quinones, R.

    2001-04-16

    The need for high-speed performance electronics in computers integrated circuits and sensors, require the fabrication of low energy consumption diodes. Nano fabrication methods require new techniques and equipment. We are currently developing a procedure to fabricate a diode based on quantum-effects. The device will act like a traditional diode, but the nanometer scale will allow it to reach high speeds without over heating. This new diode will be on a nano-bridge so it can be attenuated by an electromagnetic wave. The goal is to obtain similar current vs voltage response as in a silicon diode.

  13. 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.

  14. APPLICATION EFFECT OF SHEAR PANEL DAMPERS TO SEISMIC RETROFIT OF A NETWORK ARCH BRIDGE

    NASA Astrophysics Data System (ADS)

    Sugioka, Koichi; Shima, Kenji; Matsushita, Hiroaki

    This article describes seismic response control design using shear panel dampers for a network arch bridge. Three-dimensional non-linear dynamic time history analyses were carried out considering site-specific earthquake ground motions, to examine the correlation between shear panel damper arrangements and seismic response reductions. Different effects on seismic response reduction were significantly confirmed by the shear panel damper arrangements, and also compared between two arch bridges with different natural periods.

  15. 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.

  16. Relationship between myocardial bridging and coronary arteriosclerosis.

    PubMed

    Sun, Jian Ling; Huang, Wei Min; Guo, Ji Hong; Li, Xiao Ying; Ma, Xian Lin; Wang, Chong Yu

    2013-04-01

    The objective of the study was to explore the prevalence and characteristics of myocardial bridging in patients who underwent coronary angiography and to also evaluate the correlation between bridged coronary segments and atherosclerosis. For this purpose, clinical materials of 1,500 patients who had received coronary angiography were retrospectively analyzed. The location and length of the myocardial bridge were recorded as well as the extent and location of coronary artery stenosis was described. Segments proximal and distal to the bridging were evaluated for coronary arteriosclerosis as were the remaining coronary segments. We found that myocardial bridging was present in 179 (11.9 %) patients. Bridges were frequently (84.9 %) localized in the mid-distal segment of the left anterior descending (LAD) artery. Myocardial bridging was not considered a significant risk factor for coronary atherosclerosis (odds ratio 0.58) compared with traditional cardiovascular risk factors. The incidence of coronary arteriosclerosis in the distal segments was significantly less affected than the proximal segments (P < 0.01). It was, therefore, concluded that myocardial bridging frequently localized in the mid-distal segment of the LAD artery. The presence of myocardial bridging promotes proximal atherosclerosis but it is not an additional risk factor for coronary atherosclerosis. PMID:23076634

  17. New Bridge Plug and Retrieving Tool that Aids Completion of Geothermal Steam Wells

    SciTech Connect

    Harris, A.; Thompson, P.; Ash, D.

    1981-01-01

    A typical completion procedure requires placement of a bridge plug near the liner top of a producing steam well so the well can be loaded to permit cementing of the tieback casing string by conventional cementing techniques. A drillable bridge plug has been used in the past so that it could be removed with a conventional toothed, cone-type drill bit. All components could not be drilled out because the bridge plug would separate from the casing when drilling through its top slips. This created a hazardous situation because heavy components remaining in the well could blowout after placing the well into production and damage or destroy surface equipment. A bridge plug and its companion milling-type retrieving tool were developed to perform the bridging operation and accomplish removal in a producing geothermal steam well environment. The bridge plug features an internal briding plug that is designed to permit the release of differential pressure buildup from below before releasing the bridge plug by milling away the top slips. The millinog-type retrieving tool has a catcher mechanism designed to function in the high-velocity steam flow of a producing well to catch the released bridge plug. After the released bridge plug components are caught, they may be returned to the surface in a controlled manner. This removes the massive components so that they will not be blown out by the steam of a producing well. Field use has demonstrated that this equipment is a practical completion aid, and it is currently being used in The Geysers field of northern California. Examples of field usage are discussed in the paper.

  18. 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...

  19. 49 CFR 237.31 - Adoption of bridge management programs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Adoption of bridge management programs. 237.31... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Railroad Bridge Safety Assurance § 237.31 Adoption of bridge management programs. Each track owner shall adopt a bridge safety management program...

  20. 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...

  1. 23 CFR 650.409 - Evaluation of bridge inventory.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 23 Highways 1 2014-04-01 2014-04-01 false Evaluation of bridge inventory. 650.409 Section 650.409... 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...

  2. 23 CFR 650.307 - Bridge inspection organization.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 23 Highways 1 2011-04-01 2011-04-01 false Bridge inspection organization. 650.307 Section 650.307... BRIDGES, STRUCTURES, AND HYDRAULICS National Bridge Inspection Standards § 650.307 Bridge inspection... bridges located on public roads that are fully or partially located within the State's boundaries,...

  3. 49 CFR 237.31 - Adoption of bridge management programs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Adoption of bridge management programs. 237.31... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Railroad Bridge Safety Assurance § 237.31 Adoption of bridge management programs. Each track owner shall adopt a bridge safety management program...

  4. 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...

  5. 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...

  6. 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...

  7. 23 CFR 650.307 - Bridge inspection organization.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  8. 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...

  9. 23 CFR 650.409 - Evaluation of bridge inventory.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 23 Highways 1 2012-04-01 2012-04-01 false Evaluation of bridge inventory. 650.409 Section 650.409... 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...

  10. 49 CFR 237.103 - Bridge inspection procedures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 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...

  11. 23 CFR 650.409 - Evaluation of bridge inventory.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 23 Highways 1 2011-04-01 2011-04-01 false Evaluation of bridge inventory. 650.409 Section 650.409... 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...

  12. 49 CFR 237.101 - Scheduling of bridge inspections.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  13. 33 CFR 118.85 - Lights on vertical lift 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 vertical lift bridges... BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.85 Lights on vertical lift bridges. (a) Lift span lights. The vertical lift span of every vertical lift bridge shall be lighted so that the center of...

  14. 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...

  15. 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...

  16. 23 CFR 650.307 - Bridge inspection organization.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 23 Highways 1 2014-04-01 2014-04-01 false Bridge inspection organization. 650.307 Section 650.307... BRIDGES, STRUCTURES, AND HYDRAULICS National Bridge Inspection Standards § 650.307 Bridge inspection... bridges located on public roads that are fully or partially located within the State's boundaries,...

  17. 33 CFR 115.50 - Application for bridge permits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 49 CFR 237.31 - Adoption of bridge management programs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Adoption of bridge management programs. 237.31... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Railroad Bridge Safety Assurance § 237.31 Adoption of bridge management programs. Each track owner shall adopt a bridge safety management program...

  5. 23 CFR 650.307 - Bridge inspection organization.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Bridge inspection organization. 650.307 Section 650.307... BRIDGES, STRUCTURES, AND HYDRAULICS National Bridge Inspection Standards § 650.307 Bridge inspection... bridges located on public roads that are fully or partially located within the State's boundaries,...

  6. 23 CFR 650.307 - Bridge inspection organization.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  7. 23 CFR 650.409 - Evaluation of bridge inventory.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 23 Highways 1 2013-04-01 2013-04-01 false Evaluation of bridge inventory. 650.409 Section 650.409... 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...

  8. 49 CFR 237.31 - Adoption of bridge management programs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Adoption of bridge management programs. 237.31... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Railroad Bridge Safety Assurance § 237.31 Adoption of bridge management programs. Each track owner shall adopt a bridge safety management program...

  9. 23 CFR 650.409 - Evaluation of bridge inventory.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Evaluation of bridge inventory. 650.409 Section 650.409... 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...

  10. 49 CFR 237.31 - Adoption of bridge management programs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Adoption of bridge management programs. 237.31... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Railroad Bridge Safety Assurance § 237.31 Adoption of bridge management programs. Each track owner shall adopt a bridge safety management program...

  11. 49 CFR 237.107 - Conduct of bridge inspections.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 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...

  12. 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...

  13. 33 CFR 118.85 - Lights on vertical lift 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 vertical lift bridges... BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.85 Lights on vertical lift bridges. (a) Lift span lights. The vertical lift span of every vertical lift bridge shall be lighted so that the center of...

  14. 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...

  15. 49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 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...

  16. 49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 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...

  17. 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...

  18. 49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 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...

  19. 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...

  20. 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

  1. 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...

  2. 76 FR 55160 - Annual Materials Report on New Bridge Construction and Bridge Rehabilitation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-06

    ... 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... rehabilitation projects. Data on Federal-aid and non-Federal-aid highway bridges are included in the report...

  3. DNA materials: bridging nanotechnology and biotechnology.

    PubMed

    Yang, Dayong; Hartman, Mark R; Derrien, Thomas L; Hamada, Shogo; An, Duo; Yancey, Kenneth G; Cheng, Ru; Ma, Minglin; Luo, Dan

    2014-06-17

    CONSPECTUS: In recent decades, DNA has taken on an assortment of diverse roles, not only as the central genetic molecule in biological systems but also as a generic material for nanoscale engineering. DNA possesses many exceptional properties, including its biological function, biocompatibility, molecular recognition ability, and nanoscale controllability. Taking advantage of these unique attributes, a variety of DNA materials have been created with properties derived both from the biological functions and from the structural characteristics of DNA molecules. These novel DNA materials provide a natural bridge between nanotechnology and biotechnology, leading to far-ranging real-world applications. In this Account, we describe our work on the design and construction of DNA materials. Based on the role of DNA in the construction, we categorize DNA materials into two classes: substrate and linker. As a substrate, DNA interfaces with enzymes in biochemical reactions, making use of molecular biology's "enzymatic toolkit". For example, employing DNA as a substrate, we utilized enzymatic ligation to prepare the first bulk hydrogel made entirely of DNA. Using this DNA hydrogel as a structural scaffold, we created a protein-producing DNA hydrogel via linking plasmid DNA onto the hydrogel matrix through enzymatic ligation. Furthermore, to fully make use of the advantages of both DNA materials and polymerase chain reaction (PCR), we prepared thermostable branched DNA that could remain intact even under denaturing conditions, allowing for their use as modular primers for PCR. Moreover, via enzymatic polymerization, we have recently constructed a physical DNA hydrogel with unique internal structure and mechanical properties. As a linker, we have used DNA to interface with other functional moieties, including gold nanoparticles, clay minerals, proteins, and lipids, allowing for hybrid materials with unique properties for desired applications. For example, we recently designed a

  4. 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.

  5. Sulfur-bridged BODIPY DYEmers.

    PubMed

    Ahrens, Johannes; Böker, Birte; Brandhorst, Kai; Funk, Markus; Bröring, Martin

    2013-08-19

    Reactions of BODIPY monomers with sulfur nucleophiles and electrophiles result in the formation of new BODIPY dimers. Mono- and disulfur bridges are established, and the new dyestuff molecules were studied with respect to their structural, optical, and electrochemical properties. X-ray diffraction analyses reveal individual angulated orientations of the BODIPY subunits in all cases. DFT calculations provide solution conformers of the DYEmers which deviate in a specific manner from the crystallographic results. Clear exciton-like splittings are observed in the absorption spectra, with maxima at up to 628 nm, in combination with the expected weak fluorescence in polar solvents. A strong communication between the BODIPY subunits was detected by cyclic voltammetry, where two separated one-electron oxidation and reduction waves with peak-to-peak potential differences of 120-400 mV are observed. The qualitative applicability of the exciton model by Kasha for the interpretation of the absorption spectral shape with respect to the conformational state, subunit orientation and distance, and conjugation through the different sulfur bridges, is discussed in detail for the new BODIPY derivatives. This work is part of our concept of DYEmers, where the covalent oligomerisation of BODIPY-type dye molecules with close distances is leading to new functional dyes with predictable properties. PMID:23843344

  6. 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.

  7. Bridge Scour Measurements Using the Rfid Technology

    NASA Astrophysics Data System (ADS)

    Moustakidis, I.; Tsakiris, A. G.; Papanicolaou, T.

    2010-12-01

    The main purpose of this project is to develop a system for continuous monitoring scour around bridge piers and abutments (i.e. bridge scour) using the Radio Frequency IDentification (RFID) technology and examine its applicability for estimating scour around a pier or an existing bridge. Excessive bridge scour can compromise the bridge foundations and lead to dramatic bridge collapses with significant impacts on economy and traveling public safety. An RFID system consists of three main components: the low frequency reader (~134.2 kHz frequency), the transponder (derived from transmitter/responder) and the antenna (of rectangular shape with one or more loops). RFID is a technology that permits the wireless two-way transfer of information from a reader to a transponder via RF waves transmitted with an antenna. What makes RFIDs suitable for monitoring bridge scour is that no line of sight is necessary between the reader and the transponder, which can be detected even when it is buried in the bed substrate. The proposed system for monitoring bridge scour relies on the principle that transponders oriented perpendicular to antenna plane can be detected at longer distances, than transponders oriented parallel to it. We intend to attach transponders at predetermined locations (depths) along a chain with known length. The chain will subsequently be driven into the bed substrate at the location where bridge scour hole is expected within the detection range of the antenna, which will be installed directly above the chain. The chain will retain the transponders perpendicular to the antenna plane, so that they can be continuously detected. Once scour takes place, the transponders will be oriented parallel to the antenna plane and thus they will not be detected. The latter will indicate that bridge scour reached the known depth, at which the transponder was initially buried. Once a prototype RFID system is functional, future research will aim at combining it with satellite

  8. 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.

  9. 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.

  10. Technology transfer — bridging space and society

    NASA Astrophysics Data System (ADS)

    Students of Technology Transfer Design Project Team (ISU Summer Session 1997)

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

  11. 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…

  12. 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.

  13. 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.

  14. Current Sharing Analysis of Arm Prototype for ITER PF Converter Bridge

    NASA Astrophysics Data System (ADS)

    Li, Jinchao; Song, Zhiquan; Xu, Liuwei; Fu, Peng; Guo, Bin; Li, Sen; Dong, Lin; Wang, Min

    2014-03-01

    A bridge arm prototype of ITER poloidal field (PF) converter modules has been designed and fabricated. Non-cophase counter parallel connection is chosen as the arm structure of the prototype. Among all factors affecting current sharing, arm structure is the main one. During the design of the arm prototype, a novel method based on inductance matrixes is employed to improve the current sharing of the bridge arm. The test results on the prototype show that the current sharing performance of the arm prototype is much better than relevant design requirement, and that the matrix method is very effective to analyze and solve the current sharing problems of thyristor converters.

  15. 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.

  16. 2. Elevation of bridge taken from the southwest looking northeast. ...

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

    2. Elevation of bridge taken from the southwest looking northeast. Shows west side of bridge. - Presumpscot Falls Bridge, Spanning Presumptscot River at Allen Avenue extension, 0.75 mile west of U.S. Interstate 95, Falmouth, Cumberland County, ME

  17. 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

  18. 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

  19. 4. A river level view of the Broad Street bridge ...

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

    4. A river level view of the Broad Street bridge and Columbus skyline from the railroad truss north of the bridge. - Broad Street Bridge, Spanning Scioto River at U.S. Route 40 (Broad Street), Columbus, Franklin County, OH

  20. 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