WorldWideScience

Sample records for bridges electric

  1. Bridging peripheral nerves using a deacetyl chitin conduit combined with short-term electrical stimulation

    OpenAIRE

    Zhang, Zhongli; Xin LI; Zuo, Songjie; Xin, Jie; Zhang, Peixun

    2014-01-01

    Previous studies have demonstrated that deacetyl chitin conduit nerve bridging or electrical stimulation can effectively promote the regeneration of the injured peripheral nerve. We hypothesized that the combination of these two approaches could result in enhanced regeneration. Rats with right sciatic nerve injury were subjected to deacetyl chitin conduit bridging combined with electrical stimulation (0.1 ms, 3 V, 20 Hz, for 1 hour). At 6 and 12 weeks after treatment, nerve conduction velocit...

  2. Multifunctional electric bridge drop-in tool%多功能电桥投送器

    Institute of Scientific and Technical Information of China (English)

    杨新明; 杨清荣; 刘岳龙; 童广岩; 穆哈拜; 吕军爱

    2001-01-01

    The conventional electric bridge drop-in tool cannot carry out lowering electric bridge in casing deformation wells since its outside diameter is relatively large, a multifunction electric bridge drop-in tool is developed. The OD and length of the new tool are respectively 6mm and 452mm less than that of the conventional bridge drop-in tool, ensuring smooth lowering of the bridge. The multifunctional tool can also accomplish cementing plug with the original pipe string after dropping the bridge. Tests on 32 wells shows that the multifunctional electric bridge drop-in tool can meet the need of lowering bridge and cementing plug in casing deformation wells with an ID of over 108mm.%针对常规电桥投送器外径较大、无法在套管变形井中实施下电桥工艺的问题,研制了多功能电桥投送器。该工具的外径、长度比常规电桥投送器分别小6mm和452mm,通过能力强,能保证电桥顺利下井;同时集投送电桥与打水泥塞功能于一体,在下完电桥后用原管柱打水泥塞,减少了作业工序。32口井的现场试验表明,该工具既能满足内通径大于108mm套管变形井下电桥的需要,又能解决常规电桥投送器无法打水泥塞的问题,施工成功率为100%。

  3. Bridging peripheral nerves using a deacetyl chitin conduit combined with short-term electrical stimulation

    Institute of Scientific and Technical Information of China (English)

    Zhongli Zhang; Xin Li; Songjie Zuo; Jie Xin; Peixun Zhang

    2014-01-01

    Previous studies have demonstrated that deacetyl chitin conduit nerve bridging or electrical stimulation can effectively promote the regeneration of the injured peripheral nerve. We hypoth-esized that the combination of these two approaches could result in enhanced regeneration. Rats with right sciatic nerve injury were subjected to deacetyl chitin conduit bridging combined with electrical stimulation (0.1 ms, 3 V, 20 Hz, for 1 hour). At 6 and 12 weeks after treatment, nerve conduction velocity, myelinated axon number, ifber diameter, axon diameter and the thickness of the myelin sheath in the stimulation group were better than in the non-stimulation group. The results indicate that deacetyl chitin conduit bridging combined with temporary electrical stimu-lation can promote peripheral nerve repair.

  4. Bridging peripheral nerves using a deacetyl chitin conduit combined with short-term electrical stimulation.

    Science.gov (United States)

    Zhang, Zhongli; Li, Xin; Zuo, Songjie; Xin, Jie; Zhang, Peixun

    2014-05-15

    Previous studies have demonstrated that deacetyl chitin conduit nerve bridging or electrical stimulation can effectively promote the regeneration of the injured peripheral nerve. We hypothesized that the combination of these two approaches could result in enhanced regeneration. Rats with right sciatic nerve injury were subjected to deacetyl chitin conduit bridging combined with electrical stimulation (0.1 ms, 3 V, 20 Hz, for 1 hour). At 6 and 12 weeks after treatment, nerve conduction velocity, myelinated axon number, fiber diameter, axon diameter and the thickness of the myelin sheath in the stimulation group were better than in the non-stimulation group. The results indicate that deacetyl chitin conduit bridging combined with temporary electrical stimulation can promote peripheral nerve repair. PMID:25206762

  5. Size effects in electrical behavior of high-Tc thin-film bridges

    International Nuclear Information System (INIS)

    This paper reports on the size effects in electrical characteristics of polycrystalline YBa2Cu3O7-x thin-film bridges studied in the temperature range 4-300K. It is shown, that at T > Tc the decrease of bridge widths w from 200 to 10 μm leads to the increase of resistance R in several times and to the change in R□ (T) behavior □ from metallic type to activation type. At □ T approx-lt Tc the R□ (w) values exponentially increased when the width w was decreased under some definite size L. At T c the index Ic (T) ∼ (T - T)α changed from 3 to 1 if bridge width was decreased. Experimental data are discussed within the model, which takes into account large-scale percolation processes in the system of different intergrain Josephson junctions, where characteristic length L0 of critical subnetwork is much larger than the grain size

  6. Power management of Supercapacitors using Multi boost and Full Bridge Converters Used in Electric / Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    E.GEETHA REDDY,

    2011-06-01

    Full Text Available The Hybrid electric vehicle (HEV has become one of the most promising vehicles in the automobile industry due to its energy saving ability and low emission of harmful pollutants. Battery management system, which has acceptable life cycle, remains the major roadblock to large-scale production of Electric vehicles and Hybrid electric vehicles, which consists of high power density batteries. This paper emphasis more on the management of the energy provided by super capacitor Packs. Each super capacitors module is made of 108cells with a maximum voltage of 270V. The multi boost and multi full bridge converter topologies are tested to define the best topology for the embarked power management.. The experimental and simulated results validate the proposed two converter topologies presented in this paper.

  7. Hybrid Modulation of Bidirectional Three-Phase Dual-Active-Bridge DC Converters for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Yen-Ching Wang

    2016-06-01

    Full Text Available Bidirectional power converters for electric vehicles (EVs have received much attention recently, due to either grid-supporting requirements or emergent power supplies. This paper proposes a hybrid modulation of the three-phase dual-active bridge (3ΦDAB converter for EV charging systems. The designed hybrid modulation allows the converter to switch its modulation between phase-shifted and trapezoidal modes to increase the conversion efficiency, even under light-load conditions. The mode transition is realized in a real-time manner according to the charging or discharging current. The operation principle of the converter is analyzed in different modes and thus design considerations of the modulation are derived. A lab-scaled prototype circuit with a 48V/20Ah LiFePO4 battery is established to validate the feasibility and effectiveness.

  8. Significant manipulation of output performance of a bridge-structured spin valve magnetoresistance sensor via an electric field

    Science.gov (United States)

    Zhang, Yue; Yan, Baiqian; Ou-Yang, Jun; Wang, Xianghao; Zhu, Benpeng; Chen, Shi; Yang, Xiaofei

    2016-01-01

    Through principles of spin-valve giant magnetoresistance (SV-GMR) effect and its application in magnetic sensors, we have investigated electric-field control of the output performance of a bridge-structured Co/Cu/NiFe/IrMn SV-GMR sensor on a PZN-PT piezoelectric substrate using the micro-magnetic simulation. We centered on the influence of the variation of uniaxial magnetic anisotropy constant (K) of Co on the output of the bridge, and K was manipulated via the stress of Co, which is generated from the strain of a piezoelectric substrate under an electric field. The results indicate that when K varies between 2 × 104 J/m3 and 10 × 104 J/m3, the output performance can be significantly manipulated: The linear range alters from between -330 Oe and 330 Oe to between -650 Oe and 650 Oe, and the sensitivity is tuned by almost 7 times, making it possible to measure magnetic fields with very different ranges. According to the converse piezoelectric effect, we have found that this variation of K can be realized by applying an electric field with the magnitude of about 2-20 kV/cm on a PZN-PT piezoelectric substrate, which is realistic in application. This result means that electric-control of SV-GMR effect has potential application in developing SV-GMR sensors with improved performance.

  9. Bridging in contaminated transformer oil under DC and AC electric field

    International Nuclear Information System (INIS)

    There are two experimental set up have been established to investigate the bridging effect between two electrodes with different potentials under ac and dc voltages. This paper will explain the full details of the experimental setup and the results. These experiments carried out on pressboard particles under three different levels of ac and dc voltages. Several contamination levels have been investigated. Optical images of particle accumulation have been recorded along with associated conduction current measurement during experiments. At higher voltages the rate of bridge formation is increased along with an associated current increase. The major differences between ac and dc bridges are the shapes of the particle accumulation. The bridge formation rate for ac is slower than dc

  10. Significant manipulation of output performance of a bridge-structured spin valve magnetoresistance sensor via an electric field

    International Nuclear Information System (INIS)

    Through principles of spin-valve giant magnetoresistance (SV-GMR) effect and its application in magnetic sensors, we have investigated electric-field control of the output performance of a bridge-structured Co/Cu/NiFe/IrMn SV-GMR sensor on a PZN-PT piezoelectric substrate using the micro-magnetic simulation. We centered on the influence of the variation of uniaxial magnetic anisotropy constant (K) of Co on the output of the bridge, and K was manipulated via the stress of Co, which is generated from the strain of a piezoelectric substrate under an electric field. The results indicate that when K varies between 2 × 104 J/m3 and 10 × 104 J/m3, the output performance can be significantly manipulated: The linear range alters from between −330 Oe and 330 Oe to between −650 Oe and 650 Oe, and the sensitivity is tuned by almost 7 times, making it possible to measure magnetic fields with very different ranges. According to the converse piezoelectric effect, we have found that this variation of K can be realized by applying an electric field with the magnitude of about 2–20 kV/cm on a PZN-PT piezoelectric substrate, which is realistic in application. This result means that electric-control of SV-GMR effect has potential application in developing SV-GMR sensors with improved performance

  11. Significant manipulation of output performance of a bridge-structured spin valve magnetoresistance sensor via an electric field

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yue; Yan, Baiqian; Ou-Yang, Jun; Zhu, Benpeng; Chen, Shi; Yang, Xiaofei, E-mail: hust-yangxiaofei@163.com [School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074 (China); Wang, Xianghao [School of Information Engineering, Wuhan University of Technology, Wuhan 430070 (China)

    2016-01-28

    Through principles of spin-valve giant magnetoresistance (SV-GMR) effect and its application in magnetic sensors, we have investigated electric-field control of the output performance of a bridge-structured Co/Cu/NiFe/IrMn SV-GMR sensor on a PZN-PT piezoelectric substrate using the micro-magnetic simulation. We centered on the influence of the variation of uniaxial magnetic anisotropy constant (K) of Co on the output of the bridge, and K was manipulated via the stress of Co, which is generated from the strain of a piezoelectric substrate under an electric field. The results indicate that when K varies between 2 × 10{sup 4 }J/m{sup 3} and 10 × 10{sup 4 }J/m{sup 3}, the output performance can be significantly manipulated: The linear range alters from between −330 Oe and 330 Oe to between −650 Oe and 650 Oe, and the sensitivity is tuned by almost 7 times, making it possible to measure magnetic fields with very different ranges. According to the converse piezoelectric effect, we have found that this variation of K can be realized by applying an electric field with the magnitude of about 2–20 kV/cm on a PZN-PT piezoelectric substrate, which is realistic in application. This result means that electric-control of SV-GMR effect has potential application in developing SV-GMR sensors with improved performance.

  12. Electric double layer effect on observable characteristics of the tunnel current through a bridged electrochemical contact

    DEFF Research Database (Denmark)

    Kuznetsov, A.M.; Medvedev, I.G.; Ulstrup, Jens

    2007-01-01

    Scanning tunneling microscopy and electrical conductivity of redox molecules in conducting media (aqueous or other media) acquire increasing importance both as novel single-molecule science and with a view on molecular scale functional elements. Such configurations require full and independent el...

  13. Semiconductor bridge (SCB) detonator

    Science.gov (United States)

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

    1999-01-01

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

  14. The Development of Learning Resource for the Saleng Community under the Bridge of Zone 1 Entitled “How to Repair Electrical Appliances”

    Directory of Open Access Journals (Sweden)

    Pornpapatsorn Princhankol

    2013-12-01

    Full Text Available This research was aimed to develop a learning resource for the Saleng community under the bridge of zone 1 entitled “How to Repair Electrical Appliances” in order to determine the quality of learning community and to examine the satisfaction of the sampling group which was chosen using specified sampling method. The tools used in this study consisted of 1 learning resource for the Saleng community under the bridge of zone 1 entitled “How to Repair Electrical Appliances”, including video clips, posters, leaflets, and exhibitions; 2 the quality assessment forms; and 3 the satisfaction evaluation form. According to the quality assessment of the learning resource for the Saleng community under the bridge of zone 1 by the panel of 6 experts, the mean score for the quality in terms of contents was 4.83 with S.D. of 0.29, or at a very good level. As for the quality in terms of media, the mean score was 4.47 with S.D. of .63, or at a good level. Afterwards, the learning resource for the Saleng community under the bridge of zone 1 entitled “How to Repair Electrical Appliances” was used by the sampling group of 30 persons. The satisfaction towards the learning resource was 4.71 with S.D. of .64, or at the highest level. It could be concluded that the learning resource for the Saleng community under the bridge of zone 1 entitled “How to Repair Electrical Appliances” can be used as a practical instructional tool for the community.

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

    Science.gov (United States)

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

    2015-12-01

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

  16. A feasibility study of full-bridge type superconducting fault current controller on electric machine power stability

    Science.gov (United States)

    Jang, J. Y.; Hwang, Y. J.; Lee, J.; Ko, T. K.

    2016-02-01

    Recently, because of the advent of Smart Grid and integration of distributed generations, electrical power grids are facing uncountable challenges. Increase of fault current is one of such serious challenges and there are some fault current limiters (FCLs) that can limit the fault current. Existing grid protection FCLs, however, simply limit the fault current passively and can allow the existing protection coordination schemes to fail. This phenomenon leads to catastrophic failure in the complex system and may cause unpredictable power grid operation. Unlike a FCL, a superconducting fault current controller (SFCC) employs a full-bridge thyristor rectifier, a high temperature superconducting (HTS) DC reactor, and an embedded control unit to maintain the fault current level at a proper value by adjusting the phase angle of thyristors. This paper contains experimental and numerical analysis to design and fabricate a SFCC system for protection and stability improvement in power grids. At first, fundamental characteristics of a SFCC system were introduced. System circuit diagram and operational principles were proposed. Secondly, the developed small-scale SFCC system was introduced and verified. A 40 Vrms/30 Arms class prototype SFCC employing HTS DC reactor was fabricated and short circuit tests that simulate various fault conditions were implemented to verify the control performance of the fault current. Finally, the practical feasibility of application of the SFCC system to the power system was studied. The problems caused by three-phase faults from the power grid were surveyed and transient stability analysis of the power system was conducted by simulations. From the experimental and simulation results, we can verify the feasibility of the SFCC in power system.

  17. Electrical Effect in Silver-Point Realization Due to Cell Structure and Bias Voltage Based on Resistance Measurement Using AC and DC Bridges

    Science.gov (United States)

    Widiatmo, J. V.; Harada, K.; Yamazawa, K.; Tamba, J.; Arai, M.

    2015-08-01

    Electrical effects related to insulating leakage represent one of the major factors contributing to uncertainties in measurements using high-temperature standard platinum resistance thermometers (HTSPRTs), especially during the realization of the silver freezing point (). This work is focused on the evaluation of the differences in resistance measurements observed when using AC resistance bridges and DC resistance bridges, hereafter, termed the AC-DC differences, as the result of various electrical effects. The magnitude of the AC-DC difference in several silver-point cells is demonstrated with several HTSPRTs. The effect of the cell structure on the AC-DC difference is evaluated by exchanging some components, part by part, within a silver-point cell. Then, the effect of the bias voltage applied to the heat pipe within the silver-point furnace is evaluated. Through the analysis of the experimental results and comparison with the reports in the literature, the importance of evaluating the AC-DC difference as a means to characterize the underlying electrical effects is discussed, considering that applying a negative bias condition to the furnace with respect to the high-temperature SPRT can minimize the AC-DC difference. Concluding recommendations are proposed on the components used in silver-point cells and the application of a bias voltage to the measurement circuit to minimize the effects of the electrical leakage.

  18. Spotting the earth connection and short circuits between the electric conductors, using D.C. bridges for resistance measurements

    Science.gov (United States)

    Popa, I.; Popa, G. N.; Deaconu, S. I.; Iagăr, A.

    2015-06-01

    The paper establishes the necessary connections meant to spot the earth connections and short circuits between the conductors of a power line, using the DC bridges meant for measuring resistances between conductors at the ends of the power line. Since it is a relative method, it imposes an exact knowledge of the faulty power line setting. For values of the resistances measured between the conductors of the power line having over 1Ω at one end, the measurement will be carried out with a Wheatstone bridge, and for values below 1Ω with a Thomson bridge. In order to accurately determine the place of the fault, it measured the distances from the end of the line up to the fault and then we performed a correction calculation for this distance.

  19. A 7-Level Single DC Source Cascaded H-Bridge Multilevel Inverter with a Modified DTC Scheme for Induction Motor-Based Electric Vehicle Propulsion

    OpenAIRE

    Farid Khoucha; Khoudir Marouani; Mohamed Benbouzid; Abdelaziz Kheloui; Abdeslam Mamoune

    2013-01-01

    International audience This paper presents a new hybrid cascaded H-bridge multilevel inverter motor drive DTC scheme for electric vehicles where each phase of the inverter can be implemented using a single DC source. Traditionally, each phase of the inverter requires n DC source for (2n + 1) output voltage levels. In this paper, a scheme is proposed that allows the use of a single DC source as the first DC source which would be available from batteries or fuel cells, with the remaining (n ...

  20. Railroad Bridges

    Data.gov (United States)

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

  1. A stationary reference frame current control for a multi-level H-bridge power converter for universal and flexible power management in future electricity network

    DEFF Research Database (Denmark)

    Ciobotaru, Mihai; Iov, Florin; Zanchetta, Pericle;

    2008-01-01

    More "green" power provided by Distributed Generation will enter into the European electricity network in the near future. In order to control the power flow and to ensure proper and secure operation of this future grid, with an increased level of the renewable power, new power electronic...... converters for grid connection of renewable sources will be needed. These power converters must be able to provide intelligent power management as well as ancillary services. This paper assesses a control method based on the stationary reference frame with Proportional-Resonant current controllers...... for a multi-level cascaded H-bridges power converter used for grid applications. Harmonic content in the Point of Common Coupling, system response for bidirectional power flow, voltage and frequency excursions as well as voltage unbalances and asymmetries and low voltage ride-though capabilities are studied....

  2. A 7-Level Single DC Source Cascaded H-Bridge Multilevel Inverter with a Modified DTC Scheme for Induction Motor-Based Electric Vehicle Propulsion

    Directory of Open Access Journals (Sweden)

    Farid Khoucha

    2013-01-01

    Full Text Available This paper presents a new hybrid cascaded H-bridge multilevel inverter motor drive DTC scheme for electric vehicles where each phase of the inverter can be implemented using a single DC source. Traditionally, each phase of the inverter requires DC source for output voltage levels. In this paper, a scheme is proposed that allows the use of a single DC source as the first DC source which would be available from batteries or fuel cells, with the remaining ( DC sources being capacitors. This scheme can simultaneously maintain the capacitors of DC voltage level and produce a nearly sinusoidal output voltage due to its high number of output levels. In this context, high performances and efficient torque and flux control are obtained, enabling a DTC solution for hybrid multilevel inverter powered induction motor drives intended for electric vehicle propulsion. Simulations and experiments show that the proposed multilevel inverter and control scheme are effective and very attractive for embedded systems such as automotive applications.

  3. Harvesting vibrational energy with liquid-bridged electrodes: thermodynamics in mechanically and electrically driven RC-circuits

    CERN Document Server

    Janssen, Mathijs; van Roij, René

    2016-01-01

    We theoretically study a vibrating pair of parallel electrodes bridged by a (deformed) liquid droplet, which is a recently developed microfluidic device to harvest vibrational energy. The device can operate with various liquids, including liquid metals, electrolytes, as well as ionic liquids. We numerically solve the Young-Laplace equation for all droplet shapes during a vibration period, from which the time-dependent capacitance follows that serves as input for an equivalent circuit model. We first investigate two existing energy harvesters (with a constant and a vanishing bias potential), for which we explain an open issue related to their optimal electrode separations, which is as small as possible or as large as possible in the two cases, respectively. Then we propose a new engine with a time-dependent bias voltage, with which the harvested work and the power can be increased by orders of magnitude at low vibration frequencies and by factors 2-5 at high frequencies, where frequencies are to be compared to...

  4. Myocardial Bridging

    Directory of Open Access Journals (Sweden)

    Shi-Min Yuan

    2016-02-01

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

  5. Bridge Management Systems

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

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

  6. Programmevaluierung Bridge

    OpenAIRE

    Warta, Katharina; Good, Barbara; Geyer, Anton

    2009-01-01

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

  7. National Bridge Inventory (NBI) Bridges

    Data.gov (United States)

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

  8. Capillary bridges in electric fields

    NARCIS (Netherlands)

    Klingner, Anke; Buehrle, Juergen; Mugele, Frieder

    2004-01-01

    We analyzed the morphology of droplets of conductive liquids placed between two parallel plate electrodes as a function of the two control parameters electrode separation and applied voltage. Both electrodes were covered by thin insulating layers, as in conventional electrowetting experiments. Depen

  9. Building Bridges

    DEFF Research Database (Denmark)

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

  10. Building Bridges

    DEFF Research Database (Denmark)

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

  11. Bridged graphite oxide materials

    Science.gov (United States)

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

    2010-01-01

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

  12. Floating liquid bridge charge dynamics

    Science.gov (United States)

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

    2016-01-01

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

  13. 电磁环境下桥丝式电火工品安全性仿真研究%Simulation Study on Security of Bridge Wire Electric Explosive Device in Electromagnetic Environment

    Institute of Scientific and Technical Information of China (English)

    常新龙; 王建龙; 张磊

    2011-01-01

    The method of equivalent aerial and load was used to calculate the induced current in the bridge of bridge wire electric explosive device (EED) that caused by electromagnetic radiation. An example was used to simulate the heat effect of induced current at the interfaces between wire and powder of EED. Simulation result showed that the electromagnetic pulse of nuclear explosion usually does not cause explosion of EED, but the continuous action of high power microwave weapons can cause explosion of EED.%采用等效天线负载法计算了电磁环境下桥丝式电火工品中的辐射感应电流,结合具体算例模拟了核爆电磁脉冲和微波武器作用下桥丝中感应电流的热效应。研究结果表明,核爆电磁脉冲不易造成桥丝火工品的意外发火,但高功率微波武器的连续作用,会导致桥丝式电火工品在极短的时间内发火。

  14. Maxwell Tension Supports the Water Bridge

    OpenAIRE

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

    2008-01-01

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

  15. Cable Supported Bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

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

  16. Cascaded resonant bridge converters

    Science.gov (United States)

    Stuart, Thomas A. (Inventor)

    1989-01-01

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

  17. Taizhou Yangtze River Bridge

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

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

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

    OpenAIRE

    Marin, Alvaro G.; Lohse, Detlef

    2010-01-01

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

  19. OnWien Bridge Oscillators as Modified Multi-vibrators

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2014-01-01

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

  20. Concrete bridge prioritization system

    OpenAIRE

    Kesselring, Debbie Anne

    1995-01-01

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

  1. Bridging the Gap

    DEFF Research Database (Denmark)

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

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

  2. Bridging the Gap

    OpenAIRE

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

    2015-01-01

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

  3. Germanium-overcoated niobium Dayem bridges

    Science.gov (United States)

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

    1976-01-01

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

  4. Principles of Bridge Reliability

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Nowak, Andrzej S.

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

  5. The floating water bridge

    International Nuclear Information System (INIS)

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

  6. Bridge technology report

    CERN Document Server

    2013-01-01

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

  7. Bridged Race Population Estimates

    Data.gov (United States)

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

  8. Long Span Bridges in Scandinavia

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1998-01-01

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

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

    Science.gov (United States)

    Ma, Rongchao; Zhou, Yixin; Liu, Jing

    2015-04-01

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

  10. Integral Abutment and Jointless Bridges

    OpenAIRE

    Cristian-Claudiu Comisu

    2005-01-01

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

  11. Dynamics and stability of a vertical water bridge

    CERN Document Server

    Namin, Reza Montazeri

    2013-01-01

    A vertical connection of water is formed when a high voltage electrode is dipped in and pulled out of a container of deionized water. We considered the formation, stability and dynamical characteristics of this vertical water bridge. For the first time in this field, we observed instabilities in the bridge that led to an oscillatory behaviour which is categorized in three dynamical regimes and supplied explanations on the physics behind these varied motions. We report the formation of macroscopic droplets during this motion, which their dynamics revealed that they are electrically charged. In some cases the droplets would be levitating when the electric force opposes the gravity. Also the steady bridge is thoroughly studied regarding its geometry and a set of quantitative data is presented using dimensionless numbers, which brings the possibility of direct quantitative comparison between theory and experiments. Our results shed light on the physics behind this phenomenon and the horizontal water bridge, which...

  12. Method of controlling switching of a multiphase inductor-converter bridge. [Patent application

    Science.gov (United States)

    Kustom, R.L.; Fuja, R.E.

    In an inductor-convertor circuit for transferring electrical energy between a storage coil and a load coil through a storage thyristor bridge, a load thyristor bridge, and a set of commutating capacitors, operation is improved by a method of changing the rate of delivery of energy in a given direction. The change in rate corresponds to a predetermined change in phase angle between the load bridge and the storage bridge, and comprises changing the phase of the bridge by two steps, each equal to half the predetermined change and occurring 180/sup 0/ apart. The method assures commutation and minimizes imbalances that lead otherwise to overvoltages. 11 figures.

  13. Solar Electricity

    Science.gov (United States)

    1988-01-01

    ARCO Solar manufactures PV Systems tailored to a broad variety of applications. PV arrays are routinely used at remote communications installations to operate large microwave repeaters, TV and radio repeaters rural telephone, and small telemetry systems that monitor environmental conditions. Also used to power agricultural water pumping systems, to provide electricity for isolated villages and medical clinics, for corrosion protection for pipelines and bridges, to power railroad signals, air/sea navigational aids, and for many types of military systems. ARCO is now moving into large scale generation for utilities.

  14. Operational modal analysis of road-rail bridge

    Directory of Open Access Journals (Sweden)

    Cardoso M.

    2015-01-01

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

  15. Istanbul Bridge Conference 2014

    CERN Document Server

    Gülkan, Polat; Mahmoud, Khaled

    2016-01-01

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

  16. Active Control of Suspension Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

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

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

    CERN Document Server

    Marin, Alvaro G

    2010-01-01

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

  18. Quantum Bidding in Bridge

    Science.gov (United States)

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

    2014-04-01

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

  19. Bridge of Light

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

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

  20. Bridge over troubled water?

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  1. Building Bridges to China.

    Science.gov (United States)

    Wasta, Stephanie; Scott, Margaret

    1998-01-01

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

  2. Revised Rules for Concrete Bridges

    DEFF Research Database (Denmark)

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

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

  3. Dynamic Bridge Response for a Bridge-friendly Truck

    Directory of Open Access Journals (Sweden)

    V. Šmilauer

    2004-01-01

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

  4. [Retention of adhesive bridges].

    Science.gov (United States)

    Raes, F; De Boever, J

    1994-04-01

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

  5. BRIDGING SERVICE QUALITY GAPS

    OpenAIRE

    BARKATH UNISSA

    2012-01-01

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

  6. Bridging as Coercive Accommodation

    CERN Document Server

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

    1995-01-01

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

  7. Nematic liquid crystal bridges

    Science.gov (United States)

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

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

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

    DEFF Research Database (Denmark)

    Du, Guangli; Karoumi, Raid

    2013-01-01

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

  9. Why the Water Bridge does not collapse

    CERN Document Server

    Aerov, Artem Anatolievich

    2010-01-01

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

  10. Vulnerability of bridges to fire

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  11. 49 CFR 236.757 - Lock, electric.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Lock, electric. 236.757 Section 236.757... Lock, electric. A device to prevent or restrict the movement of a lever, a switch or a movable bridge, unless the locking member is withdrawn by an electrical device, such as an electromagnet, solenoid...

  12. Theory of bridge aerodynamics

    CERN Document Server

    Strømmen, Einar

    2006-01-01

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

  13. Modelling railway bridge asset management

    OpenAIRE

    Le, Bryant Linh Hai

    2014-01-01

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

  14. Half bridge resonant converter for ignition of thermal plasmas

    International Nuclear Information System (INIS)

    In this work the background, design, implementation and performance of a half bridge resonant converter (HBRC) used as an electronic ignition system for arc plasma torch generation is presented. The significance of the design lies in its simplicity, versatility and low cost. The system operates like a high voltage supply attached to electrodes before gaseous breakdown and like open circuit when electric arc is established. Resonant converter is implemented with a high voltage and high speed power driver intended for control the power MOSFET transistors connected in half bridge topology with L C load. The HBRC operates besides interference into domestic electric supply line (120 V, 60 Hz) as well electric measurement devices. Advantages and limitations of the converter are reviewed. Experimental impedance variation in the medium as a function of frequency operation and some experiences in striking arcs are also presented. (Author)

  15. Fatigue tests on aluminium bridges

    NARCIS (Netherlands)

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

    2005-01-01

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

  16. Fatigue tests on aluminium bridges

    NARCIS (Netherlands)

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

    2004-01-01

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

  17. Development of cooperative system bridges

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhe; WAN Qi-bai; SHI Lei

    2008-01-01

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

  18. Dynamics of a current bridge in a coaxial plasma accelerator

    Science.gov (United States)

    Voronin, A. V.; Gusev, V. K.; Kobyakov, S. V.

    2011-07-01

    The pioneering investigation of the behavior of a current bridge in a coaxial accelerator with pulsed delivery of a working gas liberated from titanium hydride by an electrical discharge is reported. A new method to trace the motion of the current bridge using LEDs is suggested. The behavior of the current bridge in accelerators with axial and radial gas injection is studied. The parameters of an accelerator generating a pure plasma jet with a high kinetic energy (such as the size and polarity of electrodes, gas flow direction, and time delay between the delivery of the gas to the accelerator and its ionization) are optimized. The applicability of an electrodynamic model to this type of accelerator is discussed. Good agreement between experimental data and calculation results is obtained.

  19. Liquid-Bridge Breaking Limits

    Science.gov (United States)

    Macner, Ashley; Steen, Paul

    2011-11-01

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

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

    Data.gov (United States)

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

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

    Data.gov (United States)

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

  2. Complex Testing of the Bridges

    Directory of Open Access Journals (Sweden)

    Savić Adrijana

    2016-01-01

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

  3. General design of Sutong Bridge

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  4. Thermal bridges of modern windows

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  5. Reliability Assessment of Concrete Bridges

    DEFF Research Database (Denmark)

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

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

  6. 46 CFR 113.35-7 - Electric engine order telegraph systems; operations.

    Science.gov (United States)

    2010-10-01

    ..., or on the wings of, the navigating bridge operate a common indicator in the engineroom, the... transmitter handle automatically connects that transmitter electrically to the engineroom indicator...

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

    Science.gov (United States)

    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.

  8. The Higgs Bridge

    CERN Document Server

    Allen, Roland E

    2013-01-01

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

  9. Mineral bridges in nacre revisited

    CERN Document Server

    Checa, Antonio G; Willinger, Marc-Georg

    2012-01-01

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

  10. Simulation of multivariate diffusion bridges

    DEFF Research Database (Denmark)

    Bladt, Mogens; Finch, Samuel; Sørensen, Michael

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

  11. Applications of overburden conveyor bridges

    Energy Technology Data Exchange (ETDEWEB)

    Schachtschneider, H.

    1987-06-01

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

  12. Bridge Culture of Langde Village

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

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

  13. ANGIOGRAPHIC ASPECTS OF MYOCARDIAL BRIDGES

    Directory of Open Access Journals (Sweden)

    Sujatha. M

    2015-12-01

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

  14. The stories of two bridges in Ghana

    DEFF Research Database (Denmark)

    Andreasen, Jørgen

    2004-01-01

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

  15. An Expert System for Concrete Bridge Management

    DEFF Research Database (Denmark)

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

    1997-01-01

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

  16. Stability of liquid crystalline bridges

    Science.gov (United States)

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

    1999-02-01

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

  17. Infrared absorption of thin films MoSi2/SiNx micro-bridge

    Science.gov (United States)

    Jiang, Bo; Su, Yan; He, Yong; Wang, Kaiying

    2016-02-01

    In this paper, we report the infrared absorption and opto-electrical characteristics of multilayered thin films of MoSi2/SiNx with a micro-bridge structure. The thin films of MoSi2 deposited by radio frequency magnetron sputtering exhibit a relatively smooth surface (RMS roughness work provides the physical understanding regarding the building of micro-bridges with the high infrared absorption.

  18. Chemical, electrochemical, and thermal bridges for transmission of OTEC power

    Energy Technology Data Exchange (ETDEWEB)

    Biederman, N.P.; Sinnott, J.; Talib, A.; Blazek, C.F.

    1978-01-01

    Chemical and electrochemical means of providing a ''bridge'' from an OTEC plant to an energy market offer a number of advantages over electric cable transmission. The most recent work done by the Institute of Gas Technology (IGT) on assessing various forms of chemical, electrochemical, and thermal energy carriers for OTEC plants is reported. These energy carriers were evaluated in terms of their overall technical feasibility and economic potential in the energy marketplace as means for augmenting conventional chemical fuels, providing peaking electric power, and as chemical feedstocks.

  19. A strange bridge by Leonardo

    CERN Document Server

    Huylebrouck, Dirk

    2013-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2006-01-01

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

  1. Bridging history and social psychology

    DEFF Research Database (Denmark)

    Glaveanu, Vlad Petre; Yamamoto, Koji

    2012-01-01

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

  2. Excitation Methods for Bridge Structures

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-02-08

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

  3. Bridge Number and Conway Products

    OpenAIRE

    Blair, Ryan C.

    2007-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    Shunquan Qin; Pu Zhou; Youheng Hua

    2004-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    LI Jian-jun

    2010-01-01

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

  6. Electric fields and quantum wormholes

    Science.gov (United States)

    Engelhardt, Dalit; Freivogel, Ben; Iqbal, Nabil

    2015-09-01

    Electric fields can thread a classical Einstein-Rosen bridge. Maldacena and Susskind have recently suggested that in a theory of dynamical gravity the entanglement of ordinary perturbative quanta should be viewed as creating a quantum version of an Einstein-Rosen bridge between the particles, or a "quantum wormhole." We demonstrate within low-energy effective field theory that there is a precise sense in which electric fields can also thread such quantum wormholes. We define a nonperturbative "wormhole susceptibility" that measures the ease of passing an electric field through any sort of wormhole. The susceptibility of a quantum wormhole is suppressed by powers of the U (1 ) gauge coupling relative to that for a classical wormhole but can be made numerically equal with a sufficiently large amount of entangled matter.

  7. Electric fields and quantum wormholes

    CERN Document Server

    Engelhardt, Dalit; Iqbal, Nabil

    2015-01-01

    Electric fields can thread a classical Einstein-Rosen bridge. Maldacena and Susskind have recently suggested that in a theory of dynamical gravity the entanglement of ordinary perturbative quanta should be viewed as creating a quantum version of an Einstein-Rosen bridge between the particles, or a "quantum wormhole". We demonstrate within low-energy effective field theory that there is a precise sense in which electric fields can also thread such quantum wormholes. We define a non-perturbative "wormhole susceptibility" that measures the ease of passing an electric field through any sort of wormhole. The susceptibility of a quantum wormhole is suppressed by powers of the U(1) gauge coupling relative to that for a classical wormhole but can be made numerically equal with a sufficiently large amount of entangled matter.

  8. Architectural engineering of FRP bridges

    OpenAIRE

    Smits, J.E.P.

    2014-01-01

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

  9. Instability of the capillary bridge

    Science.gov (United States)

    Pare, Gounseti; Hoepffner, Jerome

    2014-11-01

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

  10. Bridge Aesthetics and Structural Honesty

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

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

  11. The Wien Bridge Oscillator Family

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2006-01-01

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

  12. Architectural engineering of FRP bridges

    NARCIS (Netherlands)

    Smits, J.E.P.

    2014-01-01

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

  13. Intercellular bridges in vertebrate gastrulation.

    Directory of Open Access Journals (Sweden)

    Luca Caneparo

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

  14. Dynamic identification of paradela historic railway bridge

    OpenAIRE

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

    2013-01-01

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

  15. Transition Slabs of Integral Abutment Bridges

    OpenAIRE

    Dreier, Damien; Muttoni, Aurelio; BURDET, Olivier

    2011-01-01

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

  16. Path transformations of first passage bridges

    OpenAIRE

    Bertoin, Jean

    2003-01-01

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

  17. 47 CFR 80.331 - Bridge-to-bridge communication procedure.

    Science.gov (United States)

    2010-10-01

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

  18. Removal of failed crown and bridge.

    Science.gov (United States)

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

    2012-07-01

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

  19. Remediation: Higher Education's Bridge to Nowhere

    Science.gov (United States)

    Complete College America, 2012

    2012-01-01

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

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

    Science.gov (United States)

    Matsutani, Akihiro

    2004-05-01

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

  1. A floating water bridge produces water with excess charge

    Science.gov (United States)

    Fuchs, Elmar C.; Sammer, Martina; Wexler, Adam D.; Kuntke, Philipp; Woisetschläger, Jakob

    2016-03-01

    Excess positive and negative Bjerrum-defect like charge (protonic and ‘aterprotonic’, from ancient Greek ἄ'τɛρ, ‘without’) in anolyte and catholyte of high voltage electrolysis of highly pure water was found during the so-called ‘floating water bridge’ experiment. The floating water bridge is a special case of an electrohydrodynamic liquid bridge and constitutes an intriguing phenomenon that occurs when a high potential difference (~kV cm-1) is applied between two beakers of water. To obtain such results impedance spectroscopy was used. This measurement technique allows the depiction and simulation of complex aqueous systems as simple electric circuits. In the present work we show that there is an additional small contribution from the difference in conductivity between anolyte and catholyte which cannot be measured with a conductivity meter, but is clearly visible in an impedance spectrum.

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

    OpenAIRE

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

    2015-01-01

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

  3. New Concept for Durable Concrete Bridges

    OpenAIRE

    Damek, Marek

    2015-01-01

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

  4. 3D flexible water channel: stretchability of nanoscale water bridge

    Science.gov (United States)

    Chen, Jige; Wang, Chunlei; Wei, Ning; Wan, Rongzheng; Gao, Yi

    2016-03-01

    Artificial water channels can contribute to a better understanding of natural water channels and offer a highly selective, advanced conductance system. Most studies use nanotubes, however it is difficult to fabricate a flexible structure, and the nanosized diameter brings nanoconfinement effects, and nanotube toxicity arouses biosafety concerns. In this paper, we use an electric field to restrain the water molecules to form a nanoscale water bridge as an artificial water channel to connect a separated solid plate by molecular dynamics simulations. We observe strong 3D flexible stretchability in the water bridge, maintaining a variable length and an arbitrary angle for a considerably long time. The stretching of the water bridge enables it to be polarized at an arbitrary angle and the stretchability is linearly dependent upon the polarization strength. More interestingly, we show the possibility of establishing complex water networks, e.g., triangle, rectangle, hexagon, and tetrahedron-tetrahedron water networks. Our results may help realize structurally flexible and environmentally friendly water channels for lab-on-a-chip applications in nanofluidics.Artificial water channels can contribute to a better understanding of natural water channels and offer a highly selective, advanced conductance system. Most studies use nanotubes, however it is difficult to fabricate a flexible structure, and the nanosized diameter brings nanoconfinement effects, and nanotube toxicity arouses biosafety concerns. In this paper, we use an electric field to restrain the water molecules to form a nanoscale water bridge as an artificial water channel to connect a separated solid plate by molecular dynamics simulations. We observe strong 3D flexible stretchability in the water bridge, maintaining a variable length and an arbitrary angle for a considerably long time. The stretching of the water bridge enables it to be polarized at an arbitrary angle and the stretchability is linearly

  5. Heavy Vehicles on Minor Highway Bridges

    DEFF Research Database (Denmark)

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

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

  6. Heavy Vehicles on Minor Highway Bridges

    DEFF Research Database (Denmark)

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

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

  7. Full-bridge capacitive extensometer

    Science.gov (United States)

    Peters, Randall D.

    1993-08-01

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

  8. Noise Considerations in Resistance Bridges

    DEFF Research Database (Denmark)

    Diamond, Joseph M.

    1963-01-01

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

  9. Stability of Axisymmetric Liquid Bridges

    CERN Document Server

    Rubinstein, Boris

    2016-01-01

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

  10. 2015 Bridge Inspection ERC Training

    OpenAIRE

    Dougherty, Merril

    2015-01-01

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

  11. The Bridge Program - Participant Perspectives

    OpenAIRE

    Rönnqvist, Riitta; Hakonen, Anu; Vartiainen, Matti

    2015-01-01

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

  12. Inspection Strategies for Concrete Bridges

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    1989-01-01

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

  13. Parabolic metamaterials and Dirac bridges

    Science.gov (United States)

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

    2016-10-01

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

  14. Severe ASR damaged concrete bridges

    DEFF Research Database (Denmark)

    Antonio Barbosa, Ricardo; Gustenhoff Hansen, Søren

    2015-01-01

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

  15. Halliburton Composite Bridge Plug Assembly

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-01-15

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

  16. Nondestructive evaluation techniques for enhanced bridge inspection

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-10-01

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

  17. Study on structural system of Sutong Bridge

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  18. Evaluation method research on prestressed concrete bridges

    Institute of Scientific and Technical Information of China (English)

    HUANG Qiao; LIN Yang-zi; REN Yuan

    2008-01-01

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

  19. Research on Multidisciplinary Optimization Design of Bridge Crane

    Directory of Open Access Journals (Sweden)

    Tong Yifei

    2013-01-01

    Full Text Available Bridge crane is one of the most widely used cranes in our country, which is indispensable equipment for material conveying in the modern production. In this paper, the framework of multidisciplinary optimization for bridge crane is proposed. The presented research on crane multidisciplinary design technology for energy saving includes three levels, respectively: metal structures level, transmission design level, and electrical system design level. The shape optimal mathematical model of the crane is established for shape optimization design of metal structure level as well as size optimal mathematical model and topology optimal mathematical model of crane for topology optimization design of metal structure level is established. Finally, system-level multidisciplinary energy-saving optimization design of bridge crane is further carried out with energy-saving transmission design results feedback to energy-saving optimization design of metal structure. The optimization results show that structural optimization design can reduce total mass of crane greatly by using the finite element analysis and multidisciplinary optimization technology premised on the design requirements of cranes such as stiffness and strength; thus, energy-saving design can be achieved.

  20. 3D flexible water channel: stretchability of nanoscale water bridge.

    Science.gov (United States)

    Chen, Jige; Wang, Chunlei; Wei, Ning; Wan, Rongzheng; Gao, Yi

    2016-03-14

    Artificial water channels can contribute to a better understanding of natural water channels and offer a highly selective, advanced conductance system. Most studies use nanotubes, however it is difficult to fabricate a flexible structure, and the nanosized diameter brings nanoconfinement effects, and nanotube toxicity arouses biosafety concerns. In this paper, we use an electric field to restrain the water molecules to form a nanoscale water bridge as an artificial water channel to connect a separated solid plate by molecular dynamics simulations. We observe strong 3D flexible stretchability in the water bridge, maintaining a variable length and an arbitrary angle for a considerably long time. The stretching of the water bridge enables it to be polarized at an arbitrary angle and the stretchability is linearly dependent upon the polarization strength. More interestingly, we show the possibility of establishing complex water networks, e.g., triangle, rectangle, hexagon, and tetrahedron-tetrahedron water networks. Our results may help realize structurally flexible and environmentally friendly water channels for lab-on-a-chip applications in nanofluidics.

  1. Concrete bridge deck early problem detection and mitigation using robotics

    Science.gov (United States)

    Gucunski, Nenad; Yi, Jingang; Basily, Basily; Duong, Trung; Kim, Jinyoung; Balaguru, Perumalsamy; Parvardeh, Hooman; Maher, Ali; Najm, Husam

    2015-04-01

    More economical management of bridges can be achieved through early problem detection and mitigation. The paper describes development and implementation of two fully automated (robotic) systems for nondestructive evaluation (NDE) and minimally invasive rehabilitation of concrete bridge decks. The NDE system named RABIT was developed with the support from Federal Highway Administration (FHWA). It implements multiple NDE technologies, namely: electrical resistivity (ER), impact echo (IE), ground-penetrating radar (GPR), and ultrasonic surface waves (USW). In addition, the system utilizes advanced vision to substitute traditional visual inspection. The RABIT system collects data at significantly higher speeds than it is done using traditional NDE equipment. The associated platform for the enhanced interpretation of condition assessment in concrete bridge decks utilizes data integration, fusion, and deterioration and defect visualization. The interpretation and visualization platform specifically addresses data integration and fusion from the four NDE technologies. The data visualization platform facilitates an intuitive presentation of the main deterioration due to: corrosion, delamination, and concrete degradation, by integrating NDE survey results and high resolution deck surface imaging. The rehabilitation robotic system was developed with the support from National Institute of Standards and Technology-Technology Innovation Program (NIST-TIP). The system utilizes advanced robotics and novel materials to repair problems in concrete decks, primarily early stage delamination and internal cracking, using a minimally invasive approach. Since both systems use global positioning systems for navigation, some of the current efforts concentrate on their coordination for the most effective joint evaluation and rehabilitation.

  2. Seismic Evaluation of Highway Bridges - Phase 1

    OpenAIRE

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

    1996-01-01

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

  3. REPORT: BioMedBridges standards workshop

    OpenAIRE

    Conte, Nathalie; Hancocks, Tom; Suhr, Stephanie

    2014-01-01

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

  4. Analysis of liquid bridge between spherical particles

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

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

  5. Bridge engineering handbook construction and maintenance

    CERN Document Server

    Chen, Wai-Fah

    2014-01-01

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

  6. Markovian Bridges: Weak continuity and pathwise constructions

    OpenAIRE

    Chaumont, Loïc; Uribe Bravo, Gerónimo

    2009-01-01

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

  7. Life Cycle Assessment of a Norwegian Bridge

    OpenAIRE

    Dequidt, Thomas Charles Edouard

    2012-01-01

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

  8. Bridge Engineering-Oriented Parametric Model

    Institute of Scientific and Technical Information of China (English)

    周凌远; 李乔

    2004-01-01

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

  9. Dynamics and Statics of Nonaxisymmetric Liquid Bridges

    Science.gov (United States)

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

    1996-01-01

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

  10. Maximal liquid bridges between horizontal cylinders

    OpenAIRE

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

    2016-01-01

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

  11. Axisymmetric long liquid bridges stability and resonances

    OpenAIRE

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

    1990-01-01

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

  12. Crystal growth under bridge foundation

    OpenAIRE

    Ramon Tarragona, Anna; Alonso Pérez de Agreda, Eduardo

    2012-01-01

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

  13. Nanoclusters a bridge across disciplines

    CERN Document Server

    Jena, Purusottam

    2010-01-01

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

  14. Family Medicine: Bridge to Life.

    Science.gov (United States)

    Luz, Clare

    2016-01-01

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

  15. A bridge to advanced mathematics

    CERN Document Server

    Sentilles, Dennis

    2011-01-01

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

  16. Myocardial bridges: morphological and functional aspects.

    OpenAIRE

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

    1991-01-01

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

  17. A data management infrastructure for bridge monitoring

    Science.gov (United States)

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

    2015-04-01

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

  18. Review of Energy Harvesters Utilizing Bridge Vibrations

    Directory of Open Access Journals (Sweden)

    Farid Ullah Khan

    2016-01-01

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

  19. Gust loading on streamlined bridge decks

    DEFF Research Database (Denmark)

    Larose, Guy; Mann, Jakob

    1998-01-01

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

  20. Paramagnetic Liquid Bridge in a Gravity-Compensating Magnetic Field

    Science.gov (United States)

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

    1999-01-01

    Magnetic levitation was used to stabilize cylindrical columns of a paramagnetic liquid in air between two solid supports. The maximum achievable length to diameter ratio R(sub max) was approx. (3.10 +/- 0.07), very close to the Rayleigh-Plateau limit of pi. For smaller R, the stability of the column was measured as a function of the Bond number, which could be continuously varied by adjusting the strength of the magnetic field. Liquid bridges supported by two solid surfaces have been attracting scientific attention since the time of Rayleigh and Plateau. For a cylindrical bridge of length L and diameter d, it was shown theoretically that in zero gravity the maximum slenderness ratio R (identically = L/d) is pi. The stability and ultimate collapse of such bridges is of interest because of their importance in a number of industrial processes and their potential for low gravity applications. In the presence of gravity, however, the cylindrical shape of an axisymmetric bridge tends to deform, limiting its stability and decreasing the maximum achievable value of R. Theoretical studies have discussed the stability and possible shapes of axisymmetric bridges. Experiments typically are performed in either a Plateau tank, in which the bridge is surrounded by a density-matched immiscible fluid, or in a space-borne microgravity environment. It has been shown, for example, that the stability limit R can be pushed beyond pi by using flow stabilization, by acoustic radiation pressure, or by forming columns in the presence of an axial electric field. In this work, magnetic levitation was used to simulate a low gravity environment and create quasi-cylindrical liquid columns in air. Use of a magnetic field permits us to continuously vary the Bond number B identically equal to (g)(rho)d(exp 2)/4(sigma), where g is the gravitational acceleration, rho is the density of the liquid, and sigma is the surface tension of the liquid in air. The dimensionless Bond number represents the

  1. 49 CFR 237.101 - Scheduling of bridge inspections.

    Science.gov (United States)

    2010-10-01

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

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  3. O' Connell bridge inspection by means of Ground Penetrating Radar

    Science.gov (United States)

    Santos Assuncao, Sonia, ,, Dr

    2016-04-01

    Ground Penetrating Radar (GPR) is a well-known technique successfully applied in different areas. In structural inspection the methodology may expose information about structural arrangement and pathologies. GPR emits high frequency electromagnetic impulses allowing to detect changes on the electromagnetic properties: electrical conductivity, dielectric constant and magnetic permeability. The central frequency of the each antenna is characterized by a specific resolution and penetration depth. Therefore, different scales of structures can be analysed. High frequency antennas output high resolution images/signals about the shallowest elements such as rebar and the thickness of the first layer. On the other hand, intermediate or lower frequency antennas locate deeper structures, such as the thickness of the arch. The compilation of distinct frequencies gives a better understanding and a more accurate detection of elements in the inner structure. O'Connell Bridge (1877) is one of 24 bridges along River Liffey and one the most famous historical structures in Dublin. It is composed by sandstones and granite and covered by asphalt which represents a suitable structure to evaluate by means of GPR. The lack of inner structural information, especially the thickness of the layer, presence of reinforcement or other metallic elements of support required, at least, a dual frequency analysis of the bridge. In this case, it was applied the (200 MHz and 600 MHz) Multi-Channel Stream EM combined with 1.6 GHz GSSI high frequency antenna. The inspection of bridges by means of GPR may provide not exclusively interesting structural data but historical information and the state of conservation.

  4. The Bridge of Mandolin County

    Science.gov (United States)

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

    1999-12-01

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

  5. Conductive bridging random access memory—materials, devices and applications

    Science.gov (United States)

    Kozicki, Michael N.; Barnaby, Hugh J.

    2016-11-01

    We present a review and primer on the subject of conductive bridging random access memory (CBRAM), a metal ion-based resistive switching technology, in the context of current research and the near-term requirements of the electronics industry in ultra-low energy devices and new computing paradigms. We include extensive discussions of the materials involved, the underlying physics and electrochemistry, the critical roles of ion transport and electrode reactions in conducting filament formation and device switching, and the electrical characteristics of the devices. Two general cation material systems are given—a fast ion chacogenide electrolyte and a lower ion mobility oxide ion conductor, and numerical examples are offered to enhance understanding of the operation of devices based on these. The effect of device conditioning on the activation energy for ion transport and consequent switching speed is discussed, as well as the mechanisms involved in the removal of the conducting bridge. The morphology of the filament and how this could be influenced by the solid electrolyte structure is described, and the electrical characteristics of filaments with atomic-scale constrictions are discussed. Consideration is also given to the thermal and mechanical environments within the devices. Finite element and compact modelling illustrations are given and aspects of CBRAM storage elements in memory circuits and arrays are included. Considerable emphasis is placed on the effects of ionizing radiation on CBRAM since this is important in various high reliability applications, and the potential uses of the devices in reconfigurable logic and neuromorphic systems is also discussed.

  6. Bridge Lock-up Device System

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

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

  7. Paul Dirac:. Building Bridges of the Mind

    Science.gov (United States)

    Brown, Laurie M.

    2003-12-01

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

  8. History of cable-stayed bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

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

  9. COUPLING VIBRATION OF VEHICLE-BRIDGE SYSTEM

    Institute of Scientific and Technical Information of China (English)

    陈炎; 黄小清; 马友发

    2004-01-01

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

  10. A STUDY OF BARRIERS IN BRIDGING COMMUNICATION

    OpenAIRE

    Niteen V. Dandekar

    2014-01-01

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

  11. General framework for bridge life cycle design

    Institute of Scientific and Technical Information of China (English)

    Junhai MA; Airong CHEN; Jun HE

    2009-01-01

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

  12. Active aerodynamic stabilisation of long suspension bridges

    DEFF Research Database (Denmark)

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

    2004-01-01

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

  13. Lifetime Reliability Assessment of Concrete Slab Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

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

  14. Re-Assessment of Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

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

  15. Optimum Maintenance Strategies for Highway Bridges

    DEFF Research Database (Denmark)

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

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

  16. The I-35W bridge Project Website

    DEFF Research Database (Denmark)

    Kampf, Constance

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

  17. Modified Geometry of Transition Slabs for Integral Bridges

    OpenAIRE

    Dreier, Damien

    2010-01-01

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

  18. Building bridges … and accelerators

    CERN Multimedia

    2009-01-01

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

  19. Root coverage with bridge flap

    Directory of Open Access Journals (Sweden)

    Pushpendra Kumar Verma

    2013-01-01

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

  20. Electroless silver plating on tetraethoxy silane-bridged fiber glass

    International Nuclear Information System (INIS)

    Tetraethoxy silane was used to functionalize the surface of fiber glass (FG) for adsorption with the electroless plated silver shell. The performance of electroless silver plated FG with tetraethoxy silane modification was compared to that of unmodified FG in terms of mechanical and electrical properties. The silane bridge provided more stability for binding with different concentrations of electroless plating silver ions. The characterization was investigated by using field emission scanning electron microscope (FESEM), X-ray diffraction patterns (XRD), energy-dispersion X-ray (EDX), metal microscope (MM) and electric resistance. The Ag coating on TEOS modified FG was more durable than that of unmodified FG in the ball milling test, as confirmed by the data of electric resistance and residue weight. The optimized conditions for producing the Ag coating FG were also investigated. The Ag-Si-FG-3-c product in this study has the lowest electrical resistance of 1.56 × 103 Ω/cm2 and good mechanical stability as exhibited in ball milling tests.

  1. Oscillations in a sunspot with light bridges

    CERN Document Server

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Rong Chen

    2013-01-01

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

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

    Science.gov (United States)

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

    2015-12-01

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

  4. Signal and noise in bridging PCR

    Directory of Open Access Journals (Sweden)

    Thaler David S

    2002-07-01

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

  5. Human Errors and Bridge Management Systems

    DEFF Research Database (Denmark)

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

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

  6. Building the Clinical Bridge: An Australian Success

    Directory of Open Access Journals (Sweden)

    Marianne Wallis

    2012-01-01

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

  7. Building the clinical bridge: an Australian success.

    Science.gov (United States)

    Wallis, Marianne; Chaboyer, Wendy

    2012-01-01

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

  8. Pilot testing of a hydraulic bridge exciter

    OpenAIRE

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

    2015-01-01

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

  9. Electricity economics

    CERN Document Server

    Hu, Zhaoguang

    2013-01-01

    Systematically analyzing for the first time the production output from electricity consumption for enterprises, sectors, and industries, this study uses the function of EAI (electricity as input), and includes national E-GDP figures for more than 20 countries.

  10. Electric Power

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ China Council for the Promotion of International Trade Electric Power Industry Office (CCPIT Electric Power), one of the pro-fessional industrial branches of China Council for the Promotion of International Trade (CCPIT), was established in 2006.

  11. Embedded Electromechanical Impedance and Strain Sensors for Health Monitoring of a Concrete Bridge

    Directory of Open Access Journals (Sweden)

    Dansheng Wang

    2015-01-01

    Full Text Available Piezoelectric lead zirconate titanate (PZT is one of the piezoelectric smart materials, which has direct and converse piezoelectric effects and can serve as an active electromechanical impedance (EMI sensor. The design and fabrication processes of EMI sensors embedded into concrete structures are presented briefly. Subsequently, finite element modeling and modal analysis of a continuous rigid frame bridge are implemented by using ANSYS and MIDAS and validated by the field test results. Uppermost, a health monitoring technique by employing the embedded EMI and strain sensors is proposed in this paper. The technique is not based on any physical model and is sensitive to incipient structural changes for its high frequency characteristics. A practical study on health monitoring of the continuous rigid frame bridge is implemented based on the EMI and strain signatures. In this study, some EMI and strain sensors are embedded into the box-sectional girders. The electrical admittances of distributed EMI active sensors and the strains of concrete are measured when the bridge is under construction or in operation. Based on the electrical admittance and strain measurements, the health statuses of the continuous rigid frame bridge are monitored and evaluated successfully in the construction and operation stages using a root-mean-square deviation (RMSD index.

  12. Allegheny County-Owned Bridges Points

    Data.gov (United States)

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

  13. Allegheny County-Owned Bridges Centerlines

    Data.gov (United States)

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

  14. Influence of Icing on Bridge Cable Aerodynamics

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  15. Assessment of the Reliability of Concrete Bridges

    DEFF Research Database (Denmark)

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

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

  16. Pilot testing of a hydraulic bridge exciter

    Directory of Open Access Journals (Sweden)

    Andersson Andreas

    2015-01-01

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

  17. Practical Approach to Fragility Analysis of Bridges

    Directory of Open Access Journals (Sweden)

    Yasamin Rafie Nazari

    2012-12-01

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

  18. Bridging classical and quantum mechanics

    Science.gov (United States)

    Haddad, D.; Seifert, F.; Chao, L. S.; Li, S.; Newell, D. B.; Pratt, J. R.; Williams, C.; Schlamminger, S.

    2016-10-01

    Using a watt balance and a frequency comb, a mass-energy equivalence is derived. The watt balance compares mechanical power measured in terms of the meter, the second, and the kilogram to electrical power measured in terms of the volt and the ohm. A direct link between mechanical action and the Planck constant is established by the practical realization of the electrical units derived from the Josephson and the quantum Hall effects. By using frequency combs to measure velocities and acceleration of gravity, the unit of mass can be realized from a set of three defining constants: the Planck constant h, the speed of light c, and the hyperfine splitting frequency of 133Cs.

  19. Identifying hidden sexual bridging communities in Chicago.

    Science.gov (United States)

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

    2009-07-01

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

  20. Inspection Based Evaluation of a Danish Road Bridge

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

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

  1. TMACS test procedure TP012: Panalarm software bridge

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

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

    2011-01-01

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

  3. Experimental study of single span railway bridges

    OpenAIRE

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

    2007-01-01

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

  4. Active control of vibrations in pedestrian bridges

    OpenAIRE

    Álvaro Cunha; Carlos Moutinho

    1999-01-01

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

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

    OpenAIRE

    Rahmann, Gerold; Aksoy, Uygun

    2014-01-01

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

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

    OpenAIRE

    Rahmann, Gerold; Aksoy, Uygun

    2014-01-01

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

  7. Thermal Bridge Effects in Walls Separating Rowhouses

    DEFF Research Database (Denmark)

    Rose, Jørgen

    1997-01-01

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

  8. External Prestressing Bridge Reinforcement Technology Review

    Directory of Open Access Journals (Sweden)

    Zhu Hanbing

    2015-01-01

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

  9. Subscapularis Tendon Repair Using Suture Bridge Technique

    OpenAIRE

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

    2015-01-01

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

  10. Electrical contracting

    CERN Document Server

    Neidle, Michael

    2013-01-01

    Electrical Contracting, Second Edition is a nine-chapter text guide for the greater efficiency in planning and completing installations for the design, installation and control of electrical contracts. This book starts with a general overview of the efficient cabling and techniques that must be employed for safe wiring design, as well as the cost estimation of the complete electrical contract. The subsequent chapters are devoted to other electrical contracting requirements, including electronic motor control, lighting, and electricity tariffs. A chapter focuses on the IEE Wiring Regulations an

  11. Electric drives

    CERN Document Server

    Boldea, Ion

    2005-01-01

    ENERGY CONVERSION IN ELECTRIC DRIVESElectric Drives: A DefinitionApplication Range of Electric DrivesEnergy Savings Pay Off RapidlyGlobal Energy Savings Through PEC DrivesMotor/Mechanical Load MatchMotion/Time Profile MatchLoad Dynamics and StabilityMultiquadrant OperationPerformance IndexesProblemsELECTRIC MOTORS FOR DRIVESElectric Drives: A Typical ConfigurationElectric Motors for DrivesDC Brush MotorsConventional AC MotorsPower Electronic Converter Dependent MotorsEnergy Conversion in Electric Motors/GeneratorsPOWER ELECTRONIC CONVERTERS (PECs) FOR DRIVESPower Electronic Switches (PESs)The

  12. Framework for Bridges Maintenance in Egypt

    Directory of Open Access Journals (Sweden)

    Hesham Abd Elkhalek

    2016-01-01

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

  13. Precast Pearl-Chain concrete arch bridges

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  14. Energy conservation research of dehumidification system for main cable anticorrosion of suspension bridge

    Institute of Scientific and Technical Information of China (English)

    Chen Ce; Fan Liangkai; Feng Zhaoxiang; Pen Guanzhong

    2011-01-01

    The necessity of the main cable anticorrosion for suspension bridge is described, and operating principles and composition of main cable dehumidification system are analyzed. An idea using the waste heat of high temperature outlet air of dehumidification system to heat up regeneration air of rotary-type dehumidifier is put forward in this paper. The concrete scheme is to install a heat exchanger on air-out pipeline of roots blower and air-in pipeline of regeneration electric heater of rotary dehumidifier. Air preheated by the heat exchanger enters regeneration electric heater of rotary-type dehumidifier. Energy conservation of main cable dehumidification system for the Yangtze River highway bridge is calculated, and the results show that energy conservation rate can reach 44 %.

  15. A 15-meter Multi-Gigabit W-band Bidirectional Wireless Bridge in Fiber-Optic Access Networks

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Vegas Olmos, Juan José; Lebedev, Alexander;

    2013-01-01

    We present a bidirectional wireless bridge in the W-band enabling the seamless convergence between the wireless and fiber-optic access networks. In the downlink, a 16 Gbit/s QPSK signal is photonically up-converted at the wireless transmitter and electrically down-converted at the wireless receiver...

  16. Functional nerve recovery after bridging a 15 mm gap in rat sciatic nerve with a biodegradable nerve guide

    NARCIS (Netherlands)

    Meek, MF; Klok, F; Robinson, PH; Nicolai, JPA; Gramsbergen, A; van der Werf, J.F.A.

    2003-01-01

    Recovery of nerve function was evaluated after bridging a 15 mm sciatic nerve gap in 51 rats with a biodegradable poly(DL-lactide-epsilon-caprolactone) nerve guide. Recovery of function was investigated by analysing the footprints, by analysing video recordings of gait, by electrically eliciting the

  17. Response Modification Factors for Concrete Bridges in Europe

    OpenAIRE

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

    2013-01-01

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

  18. Evaluation of high temperature superconductive thermal bridges for space borne cryogenic detectors

    Science.gov (United States)

    Scott, Elaine P.

    1996-01-01

    Infrared sensor satellites are used to monitor the conditions in the earth's upper atmosphere. In these systems, the electronic links connecting the cryogenically cooled infrared detectors to the significantly warmer amplification electronics act as thermal bridges and, consequently, the mission lifetimes of the satellites are limited due to cryogenic evaporation. High-temperature superconductor (HTS) materials have been proposed by researchers at the National Aeronautics and Space Administration Langley's Research Center (NASA-LaRC) as an alternative to the currently used manganin wires for electrical connection. The potential for using HTS films as thermal bridges has provided the motivation for the design and the analysis of a spaceflight experiment to evaluate the performance of this superconductive technology in the space environment. The initial efforts were focused on the preliminary design of the experimental system which allows for the quantitative comparison of superconductive leads with manganin leads, and on the thermal conduction modeling of the proposed system. Most of the HTS materials were indicated to be potential replacements for the manganin wires. In the continuation of this multi-year research, the objectives of this study were to evaluate the sources of heat transfer on the thermal bridges that have been neglected in the preliminary conductive model and then to develop a methodology for the estimation of the thermal conductivities of the HTS thermal bridges in space. The Joule heating created by the electrical current through the manganin wires was incorporated as a volumetric heat source into the manganin conductive model. The radiative heat source on the HTS thermal bridges was determined by performing a separate radiant interchange analysis within a high-T(sub c) superconductor housing area. Both heat sources indicated no significant contribution on the cryogenic heat load, which validates the results obtained in the preliminary conduction

  19. Ion cyclotron resonance bridge detector for frequency sweep

    Energy Technology Data Exchange (ETDEWEB)

    Pitsakis, M.N.; Wobschall, D.C.

    1983-11-01

    An electronic ion cyclotron resonance detection system was designed and constructed. The ions are excited by sweeping the frequency of the electric field (3--300 kHz) using a sweep frequency generator with a nonlinear sweep voltage in order to maintain an approximately constant mass resolution. Ion detection is accomplished by a bridge with a phase-sensitive detector as a demodulator. The required reference signal for the phase-sensitive detector is generated by a circuit with a transfer function which approximates that of the ICR signal in order to obtain an accurate phase match between the signal source and the detector. The device is capable of detecting a minimum concentration of 50 ions/cm/sup 3/ over a mass range of 15 to 1500 amu.

  20. Ion cyclotron resonance bridge detector for frequency sweep

    Science.gov (United States)

    Pitsakis, Michael N.; Wobschall, Darold C.

    1983-11-01

    An electronic ion cyclotron resonance detection system was designed and constructed. The ions are excited by sweeping the frequency of the electric field (3-300 kHz) using a sweep frequency generator with a nonlinear sweep voltage in order to maintain an approximately constant mass resolution. Ion detection is accomplished by a bridge with a phase-sensitive detector as a demodulator. The required reference signal for the phase-sensitive detector is generated by a circuit with a transfer function which approximates that of the ICR signal in order to obtain an accurate phase match between the signal source and the detector. The device is capable of detecting a minimum concentration of 50 ions/cm3 over a mass range of 15 to 1500 amu.

  1. Method for Measuring Small Nonlinearities of Electric Characteristics

    DEFF Research Database (Denmark)

    Guldbrandsen, Tom; Meyer, Niels I; Schjær-Jacobsen, Jørgen

    1965-01-01

    A method is described for measuring very small deviations from linearity in electric characteristics. The measurement is based on the harmonics generated by the nonlinear element when subjected to a sine wave signal. A special bridge circuit is used to balance out the undesired harmonics of the s......A method is described for measuring very small deviations from linearity in electric characteristics. The measurement is based on the harmonics generated by the nonlinear element when subjected to a sine wave signal. A special bridge circuit is used to balance out the undesired harmonics...

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

    NARCIS (Netherlands)

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

    2009-01-01

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

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

    DEFF Research Database (Denmark)

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

    2008-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Lei Su-su

    2015-01-01

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

  5. Atmospheric electricity

    CERN Document Server

    Chalmers, J Alan

    1957-01-01

    Atmospheric Electricity brings together numerous studies on various aspects of atmospheric electricity. This book is composed of 13 chapters that cover the main problems in the field, including the maintenance of the negative charge on the earth and the origin of the charges in thunderstorms. After a brief overview of the historical developments of atmospheric electricity, this book goes on dealing with the general principles, results, methods, and the MKS system of the field. The succeeding chapters are devoted to some aspects of electricity in the atmosphere, such as the occurrence and d

  6. Electrical stator

    Science.gov (United States)

    Fanning, Alan W.; Olich, Eugene E.

    1994-01-01

    An electrical stator of an electromagnetic pump includes first and second spaced apart coils each having input and output terminals for carrying electrical current. An elongate electrical connector extends between the first and second coils and has first and second opposite ends. The connector ends include respective slots receiving therein respective ones of the coil terminals to define respective first and second joints. Each of the joints includes a braze filler fixedly joining the connector ends to the respective coil terminals for carrying electrical current therethrough.

  7. A probabilistic bridge safety evaluation against floods.

    Science.gov (United States)

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

    2016-01-01

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

  8. Natural vibration dynamics of Rainbow Bridge, Utah

    Science.gov (United States)

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

    2015-12-01

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

  9. Bridges in the random-cluster model

    Directory of Open Access Journals (Sweden)

    Eren Metin Elçi

    2016-02-01

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

  10. Electric machine

    Science.gov (United States)

    El-Refaie, Ayman Mohamed Fawzi; Reddy, Patel Bhageerath

    2012-07-17

    An interior permanent magnet electric machine is disclosed. The interior permanent magnet electric machine comprises a rotor comprising a plurality of radially placed magnets each having a proximal end and a distal end, wherein each magnet comprises a plurality of magnetic segments and at least one magnetic segment towards the distal end comprises a high resistivity magnetic material.

  11. Fast Hough transform for automatic bridge extraction

    Science.gov (United States)

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

    2008-03-01

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

  12. MINERAL BRIDGES OF NACRE AND ITS EFFECTS

    Institute of Scientific and Technical Information of China (English)

    宋凡; 白以龙

    2001-01-01

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

  13. MULTIPHASE BLASTING OF THE BRIDGE ACROSS THE DRENICA RIVER

    OpenAIRE

    Branko Božić

    1989-01-01

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

  14. Bridging radiation policy and science

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Hoehler, M; McCallen, D; Noble, C

    1999-06-01

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

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

    Index Scriptorium Estoniae

    Hunt, Brian

    1997-01-01

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

  18. Stability of a liquid bridge under vibration

    Science.gov (United States)

    Benilov, E. S.

    2016-06-01

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

  19. ParB spreading requires DNA bridging

    OpenAIRE

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

    2014-01-01

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

  20. Ambient Vibration Test on Reinforced Concrete Bridges

    Directory of Open Access Journals (Sweden)

    Idris Nurul Shazwin

    2016-01-01

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

  1. A Bridge Deflection Monitoring with GPS

    Science.gov (United States)

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

    2007-01-01

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

  2. Planar Hall effect bridge magnetic field sensors

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  3. Planar Hall effect bridge magnetic field sensors

    Science.gov (United States)

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

    2010-07-01

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

  4. “On a bridge in Berlin”

    DEFF Research Database (Denmark)

    Pihl, Ole Verner

    2013-01-01

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

  5. Composite timber-concrete road bridge structure

    Directory of Open Access Journals (Sweden)

    Stojić Dragoslav

    2007-01-01

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

  6. Highly conductive bridges between graphite spheres to improve the cycle performance of a graphite anode in lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hongyu [IM and T Ltd., Advanced Research Center, Saga University, Yoga-machi 1341, Saga 840-0047 (Japan); Umeno, Tatsuo; Mizuma, Koutarou [Research Center, Mitsui Mining Co. Ltd., Hibiki-machi 1-3, Wakamatsu-ku, Kitakyushu 808-0021 (Japan); Yoshio, Masaki [Advanced Research Center, Saga University, Yoga-machi 1341, Saga 840-0047 (Japan)

    2008-01-10

    Spherical carbon-coated natural graphite (SCCNG) is a promising anode material for lithium-ion batteries, but the smooth surface of graphite spheres is difficult to wet with an aqueous binder solution, and lacks electrical contacts. As a result, the cycle performance of such a graphite anode material is not satisfactory. An effective method has been introduced to tightly connect adjacent SCCNG particles by a highly conductive binder, viz. acetylene black bridges. The effect of the conductive bridges on the cyclability of SCCNG electrode has been investigated. (author)

  7. Electric fields and electrical insulation

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson

    2002-01-01

    The adoption of a field-theoretical approach to problems arising in the framework of electrical insulation is discussed with reference to six main topics, which have been addressed over the last 30 years. These include uniform field electrodes, Green's differential equation, electrode surface......, it is amply demonstrated that such an approach can lead to significant progress in many areas of electrical insulation....

  8. Bony ankylosis following thermal and electrical injury

    Energy Technology Data Exchange (ETDEWEB)

    Balen, P.F.; Helms, C.A. [Dept. of Radiology, Duke University Medical Center, Durham, NC (United States)

    2001-07-01

    Objective. Bony ankylosis has been described following trauma, paralysis, psoriasis, Reiter's syndrome, ankylosing spondylitis, juvenile chronic arthritis and rheumatoid arthritis. Reports of bony ankylosis following thermal and electrical injury are limited.Design and patients. Thirteen cases of burn-related joint ankylosis in four patients are presented.Conclusion. Patients with burns from thermal or electrical injury may develop bony ankylosis among other radiographic manifestations. This bony ankylosis may result either from bridging extra-articular heterotopic ossification with preservation of the underlying joint or from intra-articular fusion due to joint destruction. (orig.)

  9. Modification of genetic effect of gamma irradiation by electric current

    International Nuclear Information System (INIS)

    The effect of direct electric current of different value and polarity on genetic sequences of γ-irradiation of Vicia faba seedlings has been studied. The previously found modifying effect of direct electric current is confirmed. The extent and character of this effect depend on the value and polarity of current as well as time between irradiation and electric effects. Current effect modes having no effect on irradiated seedlings protecting cells from injury and the modes aggravating radiation effect have been found. At certain modes the effects of direct electric current on irradiated seedlings changes in the rearrangement spectrum are observed, particularly the number of bridges is increased

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

    Science.gov (United States)

    Harrison, D. R.; Dimeff, J.

    1972-01-01

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

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

    CERN Document Server

    Belykh, Igor; Belykh, Vladamir

    2016-01-01

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

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

    Science.gov (United States)

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

    2013-11-08

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

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

    Data.gov (United States)

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

  14. Violin Bridge Mobility Analysis under In-Plane Excitation

    Directory of Open Access Journals (Sweden)

    Cheng-Zhong Zhang

    2013-11-01

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

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

    Science.gov (United States)

    Jayakody, Jeevan A.; Nicholl, Michael J.

    2016-10-01

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

  16. Bridging the digital divide with mobile services

    CERN Document Server

    Yelton, Andromeda

    2013-01-01

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

  17. Circuit bridging of components by smoke

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-10-01

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

  18. Bridges in Mathematics. WWC Intervention Report

    Science.gov (United States)

    What Works Clearinghouse, 2009

    2009-01-01

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

  19. The Memory Bridge Initiative on Service Learners

    Science.gov (United States)

    Wescott, Amy; Healy, Tara C.

    2011-01-01

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

  20. Bridging the Gap: Pracademics in Foreign Policy

    Science.gov (United States)

    Murphy, Ann Marie; Fulda, Andreas

    2011-01-01

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

  1. Ergonomic aspects of automation in navigation bridges

    NARCIS (Netherlands)

    Lazet, A.; Walraven, P.L.

    1971-01-01

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

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

    Science.gov (United States)

    Barrett, Jan; And Others

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

  3. Journaling: A Bridge between School and Home

    Science.gov (United States)

    McGough, Julie

    2013-01-01

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

  4. 75 FR 41281 - Bridge Safety Standards

    Science.gov (United States)

    2010-07-15

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

  5. Heavy Vehicles on Minor Highway Bridges

    DEFF Research Database (Denmark)

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

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

  6. Bridging gaps : ten crosscurrents in media studies

    OpenAIRE

    Fornäs, Johan

    2008-01-01

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

  7. Steel plate reinforcement of orthotropic bridge decks

    NARCIS (Netherlands)

    Teixeira de Freitas, S.

    2012-01-01

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

  8. Aeroelastic Stability of Suspension Bridges using CFD

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  9. The mechanics of ship impacts against bridges

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup; Zhang, Shengming

    1998-01-01

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

  10. Fiber reinforced polymer composites for bridge structures

    Directory of Open Access Journals (Sweden)

    Alexandra CANTORIU

    2013-12-01

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

  11. Bridging the Gap Between Theory and Practice

    Directory of Open Access Journals (Sweden)

    Roy H.M. Sembel

    2015-05-01

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

  12. Thermal Bridge Effects in Window Grooves

    DEFF Research Database (Denmark)

    Rose, Jørgen

    1997-01-01

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

  13. Energy harvesting from electrospun piezoelectric nanofibers for structural health monitoring of a cable-stayed bridge

    Science.gov (United States)

    Maruccio, Claudio; Quaranta, Giuseppe; De Lorenzis, Laura; Monti, Giorgio

    2016-08-01

    Wireless monitoring could greatly impact the fields of structural health assessment and infrastructure asset management. A common problem to be tackled in wireless networks is the electric power supply, which is typically provided by batteries replaced periodically. A promising remedy for this issue would be to harvest ambient energy. Within this framework, the present paper proposes to harvest ambient-induced vibrations of bridge structures using a new class of piezoelectric textiles. The considered case study is an existing cable-stayed bridge located in Italy along a high-speed road that connects Rome and Naples, for which a recent monitoring campaign has allowed to record the dynamic responses of deck and cables. Vibration measurements have been first elaborated to provide a comprehensive dynamic assessment of this infrastructure. In order to enhance the electric energy that can be converted from ambient vibrations, the considered energy harvester exploits a power generator built using arrays of electrospun piezoelectric nanofibers. A finite element analysis is performed to demonstrate that such power generator is able to provide higher energy levels from recorded dynamic loading time histories than a standard piezoelectric energy harvester. Its feasibility for bridge health monitoring applications is finally discussed.

  14. Electrical Conductivity.

    Science.gov (United States)

    Hershey, David R.; Sand, Susan

    1993-01-01

    Explains how electrical conductivity (EC) can be used to measure ion concentration in solutions. Describes instrumentation for the measurement, temperature dependence and EC, and the EC of common substances. (PR)

  15. Electricity derivatives

    CERN Document Server

    Aïd, René

    2015-01-01

    Offering a concise but complete survey of the common features of the microstructure of electricity markets, this book describes the state of the art in the different proposed electricity price models for pricing derivatives and in the numerical methods used to price and hedge the most prominent derivatives in electricity markets, namely power plants and swings. The mathematical content of the book has intentionally been made light in order to concentrate on the main subject matter, avoiding fastidious computations. Wherever possible, the models are illustrated by diagrams. The book should allow prospective researchers in the field of electricity derivatives to focus on the actual difficulties associated with the subject. It should also offer a brief but exhaustive overview of the latest techniques used by financial engineers in energy utilities and energy trading desks.

  16. Electrical injury

    Science.gov (United States)

    ... electricity, such as a rubber mat or folded newspapers. 4. Once the person is away from the ... Walls RM, et al., eds. Rosen's Emergency Medicine: Concepts and Clinical Practice . 8th ed. Philadelphia, PA: Elsevier ...

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

    OpenAIRE

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

    2013-01-01

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

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

    OpenAIRE

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

    2009-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

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

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

    OpenAIRE

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

    2012-01-01

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

  1. Rupture of an Evaporating Liquid Bridge between Two Grains

    OpenAIRE

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

    2014-01-01

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

  2. TorBricks: Blocking-Resistant Tor Bridge Distribution

    OpenAIRE

    Zamani, Mahdi; Saia, Jared; Crandall, Jedidiah

    2016-01-01

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

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

    Data.gov (United States)

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

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

    Science.gov (United States)

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

    2014-04-01

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

  5. Electricity futures

    OpenAIRE

    Falbo P; Felletti, D; S. De Stefani

    2016-01-01

    This chapter describes forwards and futures for electricity currently traded in Europe and other markets. Due to the non-storability of electricity, spot prices are highly dependent on local supply and demand conditions, business activity, and weather conditions. Seasonality is also very strong during the day (peak versus off-peak hours), during the week, and during cold and hot seasons. As a consequence, liquidity is low and the day-to-day volatility is much higher than in financial ma...

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

    Science.gov (United States)

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

    2015-12-01

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

  7. Three-phase electric drive with modified electronic smoothing inductor

    DEFF Research Database (Denmark)

    Singh, Yash Veer; Rasmussen, Peter Omand; Andersen, Torben Ole

    2010-01-01

    This paper presents a three-phase electric drive with a modified electronic smoothing inductor (MESI) having reduced size of passive components. The classical electronic smoothing inductor (ESI) is able to control a diode bridge output current and also reduce not only mains current harmonics but ...

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

    OpenAIRE

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

    2012-01-01

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

  9. 49 CFR 237.31 - Adoption of bridge management programs.

    Science.gov (United States)

    2010-10-01

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

  10. Ambient Response Analysis of the Great Belt Bridge

    DEFF Research Database (Denmark)

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

    2000-01-01

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

  11. 23 CFR 650.409 - Evaluation of bridge inventory.

    Science.gov (United States)

    2010-04-01

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

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

    NARCIS (Netherlands)

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

    2015-01-01

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

  13. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Science.gov (United States)

    2010-04-01

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

  14. Resin-Bonded Bridges in vitro and in vivo

    NARCIS (Netherlands)

    Veen, Johannes Hilbrandt van der

    1988-01-01

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

  15. Bridged Quaterphenyls as Flashlamp-Pumpable Laser Dyes

    OpenAIRE

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

    1987-01-01

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

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

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

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

  17. Renovation techniques for fatigue cracked orthotropic steel bridge decks

    NARCIS (Netherlands)

    de Jong, F.B.P.

    2007-01-01

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

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

    Data.gov (United States)

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

  19. Microelectronics-embedded channel bridging and signal regeneration of injured spinal cords

    Institute of Scientific and Technical Information of China (English)

    Zhigong Wang; Xiaosong Gu; Xiaoying Lü; Zhenglin Jiang; Wenyuan Li; Guangming Lü; Yufeng Wang; Xiaoyan Shen; Xintai Zhao; Huiling Wang; Zhenyu Zhang; Hongmei Shen; Yang Wu; Weixing Shen; Jingyang Zhang; Dong Chen; Xiaoyi Mao; Huaxiang Shen

    2009-01-01

    Due to the difficulty in spinal cord regeneration with biological methods, the microelectronic neural bridge, a new concept based on microelectronic technology, is presented. The microelectronic system has been realized in the forms of hybrid and integrated circuits. The integrated circuits for neural signal detection, stimulation, and regeneration are realized in a CMOS process. In animal experiments with 100 toads, 48 rats, and 3 rabbits, nerve signals have been successfully detected from spinal cords and sciatic nerves, and functional electrical stimulation has been carried out for spinal cords and sciatic nerves. When the microelectronic system is bridged between the controlling and stimulated nerve, the relevant motion of legs and nerve signal waveforms, which are stimulated by the evoked or spontaneous nerve signal through such a system, have been observed. Therefore, the feasibility of the presented method was demonstrated.

  20. Electrical Resistance and Microstructure of Latex Modified Carbon Fiber Reinforced Cement Composites

    Institute of Scientific and Technical Information of China (English)

    WEI Jian; CHENG Feng; YUAN Hudie

    2012-01-01

    The electrical resistance,flexural strength,and microstructure of carbon fiber reinforced cement composites (CFRC) were improved greatly by adding water-redispersible latex powder.The electrical resistance of CFRC was investigated by two-probe method.The input range of CFRC based strain sensors was therefore increased,whereas electrical resistance was increased and remained in the perfect range of CFRC sensors.The analysis of scanning electron microscopy indicated that elastic latex bridges and a latex layer existed among the interspaces of the adjacent cement hydration products which were responsible for the enhancement of the flexural strength and electrical resistance.The formation mechanism of the elastic latex bridges was also discussed in detail.The continuous moving of two opposite interfaces of the latex solution-air along the interspaces of the adjacent hydrated crystals or colloids was attributed to the formation of the elastic latex bridges.

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

    OpenAIRE

    Shrikant D. Bobade *, Dr. Valsson Varghese

    2016-01-01

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

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

    DEFF Research Database (Denmark)

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

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

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

    DEFF Research Database (Denmark)

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

    1998-01-01

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

  4. Seismic Passive Control of Cable-Stayed Bridges

    Directory of Open Access Journals (Sweden)

    Hosam-Eddin M. Ali

    1995-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  6. Suspension Bridge Flutter for Girder with Separate Control Flaps

    DEFF Research Database (Denmark)

    Huynh, T.; Thoft-Christensen, Palle

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

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

    OpenAIRE

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

    1980-01-01

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

  8. Excitation of Arch and Suspension Bridges by Subwires

    Directory of Open Access Journals (Sweden)

    Noriaki Hiwatashi

    1993-01-01

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

  9. Excitation of Arch and Suspension Bridges by Subwires

    OpenAIRE

    Noriaki Hiwatashi; Yoji Mizuta; Yutaka Ishihara; Itio Hirai

    1993-01-01

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

  10. Violin Bridge Mobility Analysis under In-Plane Excitation

    OpenAIRE

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

    2013-01-01

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

  11. Translating Climate Projections for Bridge Engineering

    Science.gov (United States)

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

    2015-12-01

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

  12. Bridge health assessment system with fatigue analysis algorithm

    Science.gov (United States)

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

    2005-05-01

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

  13. A Review of Indirect Bridge Monitoring Using Passing Vehicles

    Directory of Open Access Journals (Sweden)

    Abdollah Malekjafarian

    2015-01-01

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

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

    DEFF Research Database (Denmark)

    Du, Guangli; Pettersson, Lars; Karoumi, Raid

    2016-01-01

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

  15. Online Bridge Crack Monitoring with Smart Film

    Directory of Open Access Journals (Sweden)

    Benniu Zhang

    2013-01-01

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

  16. Bridge Condition Assessment Using D Numbers

    Directory of Open Access Journals (Sweden)

    Xinyang Deng

    2014-01-01

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

  17. Accelerated aging of polymer composite bridge materials

    Science.gov (United States)

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

    1999-05-01

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

  18. Tacoma Bridge Failure-- a Physical Model

    CERN Document Server

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

    2004-01-01

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

  19. Fatigue-Prone Details in Steel Bridges

    Directory of Open Access Journals (Sweden)

    Mohsen Heshmati

    2012-11-01

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

  20. A liquid bridge connecting moving porous surfaces

    Science.gov (United States)

    Gharib, Morteza; Gat, Amir; Navaz, Homayun

    2011-11-01

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

  1. Bridging the Divide between Science and Journalism

    OpenAIRE

    Marincola Francesco M; Van Eperen Laura; Strohm Jennifer

    2010-01-01

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

  2. Fatigue-Prone Details in Steel Bridges

    OpenAIRE

    Mohsen Heshmati; Mohammad Al-Emrani; Reza Haghani

    2012-01-01

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

  3. Design of bridges against large tectonic deformation

    Institute of Scientific and Technical Information of China (English)

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

    2008-01-01

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

  4. Bridge Inspections and Being an ERC

    OpenAIRE

    Hoernschemeyer, Keith; Miller, Jessica

    2015-01-01

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

  5. Liquid bridge simulations with OpenFOAM

    OpenAIRE

    Guirao Aguilar, Guillermo

    2011-01-01

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

  6. Legendrian framings for two-bridge links

    CERN Document Server

    Baader, Sebastian

    2009-01-01

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

  7. Ether bridge formation in loline alkaloid biosynthesis

    OpenAIRE

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

    2013-01-01

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

  8. Bridging the Gap: Linking Simulation and Testing

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-09-01

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

  9. Bridge concrete deteriorating diagnosis by infrared thermography

    Science.gov (United States)

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

    2006-04-01

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

  10. Electric field control of a fluid transfer between freely suspended and sessile droplets

    Science.gov (United States)

    Choi, Suhwan; Saveliev, Alexei

    2015-11-01

    This works explore direct fluid transfer between microdroplets using liquid bridges stabilized by ac electric field. Experiments are performed with freely and sessile microdroplets of pure glycerol and water with dye. The droplets are placed along electric field directions in a cell with parallel plate electrodes filled with silicone oil. The electrical conductivity of droplets is changed from 1 to 200 μS/cm by adding dye solutions. Liquid bridges interconnecting two microdroplets can be created using an alternating electric field from 0.3 to 0.7 kV/mm with a frequency of 10.3 kHz. For such bridging fluid can be transferred through the liquid bridge from one droplet to another due to the pressure difference. The process is recorded using a CCD camera. The fluid flowrates in the range from ~ 100 to 10 nL/s are recorded with different electric fields and liquid conductivity. We propose that the manipulation of the liquid bridge will be the method in which small fluid volumes are dispensed.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-01

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

  12. The Internet Inter-Orb Protocol Security Bridge

    Directory of Open Access Journals (Sweden)

    Pawel Slowikowski

    1999-01-01

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

  13. Electroacoustic absorbers: bridging the gap between shunt loudspeakers and active sound absorption.

    Science.gov (United States)

    Lissek, Hervé; Boulandet, Romain; Fleury, Romain

    2011-05-01

    The acoustic impedance at the diaphragm of an electroacoustic transducer can be varied using a range of basic electrical control strategies, amongst which are electrical shunt circuits. These passive shunt techniques are compared to active acoustic feedback techniques for controlling the acoustic impedance of an electroacoustic transducer. The formulation of feedback-based acoustic impedance control reveals formal analogies with shunt strategies, and highlights an original method for synthesizing electric networks ("shunts") with positive or negative components, bridging the gap between passive and active acoustic impedance control. This paper describes the theory unifying all these passive and active acoustic impedance control strategies, introducing the concept of electroacoustic absorbers. The equivalence between shunts and active control is first formalized through the introduction of a one-degree-of-freedom acoustic resonator accounting for both electric shunts and acoustic feedbacks. Conversely, electric networks mimicking the performances of active feedback techniques are introduced, identifying shunts with active impedance control. Simulated acoustic performances are presented, with an emphasis on formal analogies between the different control techniques. Examples of electric shunts are proposed for active sound absorption. Experimental assessments are then presented, and the paper concludes with a general discussion on the concept and potential improvements.

  14. Electroacoustic absorbers: bridging the gap between shunt loudspeakers and active sound absorption.

    Science.gov (United States)

    Lissek, Hervé; Boulandet, Romain; Fleury, Romain

    2011-05-01

    The acoustic impedance at the diaphragm of an electroacoustic transducer can be varied using a range of basic electrical control strategies, amongst which are electrical shunt circuits. These passive shunt techniques are compared to active acoustic feedback techniques for controlling the acoustic impedance of an electroacoustic transducer. The formulation of feedback-based acoustic impedance control reveals formal analogies with shunt strategies, and highlights an original method for synthesizing electric networks ("shunts") with positive or negative components, bridging the gap between passive and active acoustic impedance control. This paper describes the theory unifying all these passive and active acoustic impedance control strategies, introducing the concept of electroacoustic absorbers. The equivalence between shunts and active control is first formalized through the introduction of a one-degree-of-freedom acoustic resonator accounting for both electric shunts and acoustic feedbacks. Conversely, electric networks mimicking the performances of active feedback techniques are introduced, identifying shunts with active impedance control. Simulated acoustic performances are presented, with an emphasis on formal analogies between the different control techniques. Examples of electric shunts are proposed for active sound absorption. Experimental assessments are then presented, and the paper concludes with a general discussion on the concept and potential improvements. PMID:21568400

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

    CERN Document Server

    Bakht, Baidar

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Yao-Min Fang

    2007-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xin-jun; YING Lei-dong

    2007-01-01

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

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

    Science.gov (United States)

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

    2016-04-01

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

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

    Science.gov (United States)

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

    2016-04-26

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

  20. Chaos in electric drive systems analysis control and application

    CERN Document Server

    Chau, K T

    2011-01-01

    In Chaos in Electric Drive Systems: Analysis, Control and Application authors Chau and Wang systematically introduce an emerging technology of electrical engineering that bridges abstract chaos theory and practical electric drives. The authors consolidate all important information in this interdisciplinary technology, including the fundamental concepts, mathematical modeling, theoretical analysis, computer simulation, and hardware implementation. The book provides comprehensive coverage of chaos in electric drive systems with three main parts: analysis, control and application. Corresponding drive systems range from the simplest to the latest types: DC, induction, synchronous reluctance, switched reluctance, and permanent magnet brushless drives.The first book to comprehensively treat chaos in electric drive systemsReviews chaos in various electrical engineering technologies and drive systemsPresents innovative approaches to stabilize and stimulate chaos in typical drivesDiscusses practical application of cha...

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

    Institute of Scientific and Technical Information of China (English)

    Zhang Hong; Luo Chenbin; Zhang Yongtao; You Xinpeng

    2009-01-01

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

  2. Solar Powered Full Bridge FET SMPS based Pulse Battery Charger with Power Management Using Atmega328

    Directory of Open Access Journals (Sweden)

    Apoorva Batra

    2013-04-01

    Full Text Available This paper aims to build a microcontroller based SMPS full wave bridge power transfer system that will also incorporate some domestic alerting mechanisms, such as security-alert, mail notification, flooding, smoke detection etc. The solar energy is utilized to charge a battery, which in turn will power up the system to drive various modules. This helps the system to be a completely stand-alone device. Along with usage of renewable energy, the paper also aims at protecting the electrical devices in a domestic setting from power-fluctuations or a brown-out.

  3. Micro-agar salt bridge in patch-clamp electrode holder stabilizes electrode potentials

    OpenAIRE

    Shao, Xuesi M; Feldman, Jack L.

    2006-01-01

    Maintaining a stable electrode potential is critical for patch-clamp measurements. The electrode potential of conventional patch electrode-holder assembly, where an Ag/AgCl wire is in direct contact with the patch pipette filling solution, is subject to drift if the pipette solution contains a low concentration of chloride ions (Cl−). We developed an agar bridge of 3 M KCl filled in a polyimide microtubing which forms an electrical connection between an Ag/AgCl wire and the pipette solution. ...

  4. On equivalent resistance of electrical circuits

    CERN Document Server

    Kagan, Mikhail

    2015-01-01

    While the standard (introductory physics) way of computing the equvalent resistance of non-trivial electrical ciruits is based on Kirchhoff's rules, there is a mathematically and conceptually simpler approach, called the method of nodal potentials, whose basic variables are the values of electric potential at the circuit's nodes. In this paper, we review the method of nodal potentials and illustrate it using the Wheatstone bridge as an example. At the end, we derive - in a closed form - the equivalent resistance of a generic circuit, which we apply to a few sample circuits. The final result unveils a curious interplay between electrical circuits, matrix algebra, and graph theory and its applications to computer science. The paper is written at a level accessible by undergraduate students who are familiar with matrix arithmetic. For the more inquisitive reader, additional proofs and technical details are provided in the appendix.

  5. Electricity unplugged

    Science.gov (United States)

    Karalis, Aristeidis

    2009-02-01

    The judge was driving back late one cold winter night. Entering the garage, the battery-charging indicator in his wirelessly powered electric car came on. "Home at last," crossed his mind. He swiped his personal smartcard on the front-door detector to be let in. He heard a "charging" beep from his mobile phone. The blinking cursor on the half-finished e-mail on the laptop had been waiting all day on the side table. He picked the computer up and walked towards his desk. "Good evening, your honour. Your wirelessly heated robe," said the butler-robot as it approached from the kitchen. Putting on the electric garment, he sat on the medical desk chair. His artificial heart was now beating faster.

  6. Cascaded H-bridge multilevel inverter for renewable energy generation

    Science.gov (United States)

    Pandey, Ravikant; Nath Tripathi, Ravi; Hanamoto, Tsuyoshi

    2016-04-01

    In this paper cascaded H-bridge multilevel inverter (CHBMLI) has been investigated for the application of renewable energy generation. Energy sources like solar, wind, hydro, biomass or combination of these can be manipulated to obtain alternative sources for renewable energy generation. These renewable energy sources have different electrical characteristics like DC or AC level so it is challenging to use generated power by connecting to grid or load directly. The renewable energy source require specific power electronics converter as an interface for conditioning generated power .The multilevel inverter can be utilized for renewable energy sources in two different modes, the power generation mode (stand-alone mode), and compensator mode (statcom). The performance of the multilevel inverter has been compared with two level inverter. In power generation mode CHBMLI supplies the active and reactive power required by the different loads. For operation in compensator mode the indirect current control based on synchronous reference frame theory (SRFT) ensures the grid operating in unity power factor and compensate harmonics and reactive power.

  7. Minimally-invasive transepidermal potentiometry with microneedle salt bridge.

    Science.gov (United States)

    Abe, Yuina; Nagamine, Kuniaki; Nakabayashi, Mayu; Kai, Hiroyuki; Kaji, Hirokazu; Yamauchi, Takeshi; Yamasaki, Kenshi; Nishizawa, Matsuhiko

    2016-08-01

    A commercial painless microneedle was filled with physiological saline agar, and this needle-based salt bridge was inserted into the skin (a piece of porcine skin and a flank skin of a live mouse) to make an electrical contact with its subepidermal region. The transepidermal potential (TEP), the potential difference between the skin surface and the subepidermal region, was measured using this inner electrode and a conventional agar electrode on the surface of the skin. Control of penetration depth of the inner electrode with a spacer and hydrophilic pretreatment with ozone plasma were found to be necessary for stable measurement. The TEP was reduced upon damages on the skin surface by tape stripping and acetone defatting, which indicated the fabricated needle electrode is useful for the minimally-invasive measurement of TEP and evaluation of skin barrier functions. Furthermore, we showed that the device integrating two electrodes into a single compact probe was useful to evaluate the local barrier functions and their mapping on a skin. This device could be a personal diagnostic tool in the fields of medicine and cosmetics in future.

  8. Investigation of Aerodynamic Interference of Double Deck Bridges

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-05-01

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

  9. Electric Car

    Science.gov (United States)

    1977-01-01

    NASA's Lewis Research Center undertook research toward a practical, economical battery with higher energy density. Borrowing from space satellite battery technology, Lewis came up with a nickel-zinc battery that promises longer life and twice the range of the lead-acid counterpart. Lewis researchers fabricated a prototype battery and installed it in an Otis P-500 electric utility van, using only the battery space already available and allowing battery weight equal to that of the va's conventional lead-acid battery

  10. Electrical cardioversion

    International Nuclear Information System (INIS)

    External electrical cardioversion was first performed in the 1950s. Urgent or elective cardioversions have specific advantages, such as termination of atrial and ventricular tachycardia and recovery of sinus rhythm. Electrical cardioversion is life-saving when applied in urgent circumstances. The success rate is increased by accurate tachycardia diagnosis, careful patient selection, adequate electrode (paddles) application, determination of the optimal energy and anesthesia levels, prevention of embolic events and arrythmia recurrence and airway conservation while minimizing possible complications. Potential complications include ventricular fibrillation due to general anesthesia or lack of synchronization between the direct current (DC) shock and the QRS complex, thromboembolus due to insufficient anticoagulant therapy, non-sustained VT, atrial arrhythmia, heart block, bradycardia, transient left bundle branch block, myocardial necrosis, myocardial dysfunction, transient hypotension, pulmonary edema and skin burn. Electrical cardioversion performed in patients with a pacemaker or an incompatible cardioverter defibrillator may lead to dysfunction, namely acute or chronic changes in the pacing or sensitivity threshold. Although this procedure appears fairly simple, serious consequences might occur if inappropriately performed. (author)

  11. Structural safety monitoring for Nanjing Yangtze River Bridge

    Institute of Scientific and Technical Information of China (English)

    黄方林; 何旭辉; 陈政清; 曾储惠

    2004-01-01

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

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

    Science.gov (United States)

    Brown, Jeff; Fox, Terra

    2010-05-01

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

  13. Detection of Subsurface Defects in Concrete Bridge Deck Joints

    Directory of Open Access Journals (Sweden)

    Wonchang Choi

    2011-01-01

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

  14. Dynamic Vehicle Impact for Safety Assessment of Bridges

    DEFF Research Database (Denmark)

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

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

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

    DEFF Research Database (Denmark)

    Hansen, Henriette I.; Thoft-Christensen, Palle

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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  18. Salt bridge as a gatekeeper against partial unfolding.

    Science.gov (United States)

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

    2016-05-01

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

  19. Abutments influence in the dynamic response of bridges

    OpenAIRE

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

    1996-01-01

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

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

    OpenAIRE

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

    2014-01-01

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

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

    OpenAIRE

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

    2010-01-01

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

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

    OpenAIRE

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

    2006-01-01

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

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

    OpenAIRE

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

    2003-01-01

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

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

    OpenAIRE

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

    2009-01-01

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

  5. Commutation Processes in Multiresonant ZVS Bridge Converter

    Directory of Open Access Journals (Sweden)

    Miroslaw Luft

    2008-01-01

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

  6. Bridge connection of quantum Hall elementary devices

    CERN Document Server

    Callegaro, Luca

    2013-01-01

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

  7. Fatigue Performance of Bridge Deck Pavement Materials

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  8. Comparison of Temperature Loadings of Bridge Girders

    Directory of Open Access Journals (Sweden)

    J. Římal

    2008-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2008-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xin-jun; SUN Bing-nan

    2005-01-01

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

  11. Assessment of concrete bridge decks with alkali silica reactions

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  12. Modulating unimolecular charge transfer by exciting bridge vibrations.

    Science.gov (United States)

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

    2009-12-23

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

  13. Method of tuning a strain gauge full bridge

    International Nuclear Information System (INIS)

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

  14. Theoretical mechanics: Crowd synchrony on the Millennium Bridge

    Science.gov (United States)

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

    2005-11-01

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

  15. Geodetic Measurement of Longitudinal Displacements of the Railway Bridge

    Directory of Open Access Journals (Sweden)

    Jaroslav Braun

    2014-06-01

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

  16. Running Safety of Trains under Vessel-Bridge Collision

    Directory of Open Access Journals (Sweden)

    Yongle Li

    2015-01-01

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

  17. Measurement evaluation and FEM simulation of bridge dynamics

    OpenAIRE

    Andersson, Andreas; Malm, Richard

    2004-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-04-21

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

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

    Science.gov (United States)

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

    2006-02-01

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

  20. COMPARISON OF TRUNK MUSCLE ACTIVITY DURING BRIDGING EXERCISES USING A SLING IN PATIENTS WITH LOW BACK PAIN

    Directory of Open Access Journals (Sweden)

    HyungKyu Kang

    2012-09-01

    Full Text Available The aims of this study were to compare the activation of global and local muscles of the trunk during bridging with sling exercise (BSE, bridging with ball exercise (BBE, and normal bridging exercise (NBE and to conduct and analyze these exercises in supine and prone positions to prove the effectiveness of sling exercises. Thirty patients with current low back pain (LBP were recruited. In the supine and prone bridging exercise, each subject lifted their pelvis with their legs and feet in contact with the sling, ball, or normal surface. The electrical activities of the inferior oblique (IO, rectus abdominis (RA, multifidus (MF, and erector spinae (ES muscles during the bridging exercises on the 3 surfaces were measured using surface electromyography (sEMG. For normalization, maximum sEMG signals were evaluated during each maximum voluntary isometric contraction (MVIC maneuver. The root mean square during the exercise was normalized as a percentage of the MVIC (%MVIC. In the supine and prone positions, %MVIC of the IO, RA, MF, and ES during BSE was significantly higher than those during BBE and NBE (p < 0.05. In the supine position, %MVIC of the RA and ES during BBE was significantly higher than that during NBE (p < 0.05. In the prone position, all %MVIC during BBE were significantly higher than NBE (p < 0.05. These results verify the theory that the use of an unstable surface increases the activation of global and local trunk muscles during bridging exercises in the supine and prone positions. In conclusion, the use of BSE in a rehabilitation program may have therapeutic effects for patients with LBP by increasing trunk muscle activation

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

    DEFF Research Database (Denmark)

    Nielsen, Anders

    1999-01-01

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

  2. Electrical machine

    Energy Technology Data Exchange (ETDEWEB)

    De Bock, Hendrik Pieter Jacobus; Alexander, James Pellegrino; El-Refaie, Ayman Mohamed Fawzi; Gerstler, William Dwight; Shah, Manoj Ramprasad; Shen, Xiaochun

    2016-06-21

    An apparatus, such as an electrical machine, is provided. The apparatus can include a rotor defining a rotor bore and a conduit disposed in and extending axially along the rotor bore. The conduit can have an annular conduit body defining a plurality of orifices disposed axially along the conduit and extending through the conduit body. The rotor can have an inner wall that at least partially defines the rotor bore. The orifices can extend through the conduit body along respective orifice directions, and the rotor and conduit can be configured to provide a line of sight along the orifice direction from the respective orifices to the inner wall.

  3. Electricity supply

    International Nuclear Information System (INIS)

    In the 1960's and early 1970s, nuclear power plants offered economic and environmental advantages over coal plants; most were completed on time and at reasonable cost and still operate today, providing economical, reliable electricity. In the 1970s, a series of events, beginning with the 1973-74 recession and culminating with the Three Mile Island accident, adversely affected the nuclear industry. According to experts, reviving the nuclear option requires increased public acceptance and reduced financial risks. The public's concerns about safety need to be allayed through the safe, efficient operation of current plants and improved designs

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

    Science.gov (United States)

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

    2016-01-01

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

  5. The iron abundance of the Magellanic Bridge

    CERN Document Server

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

    2008-01-01

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

  6. A review of bridge scour monitoring techniques

    Institute of Scientific and Technical Information of China (English)

    L.J. Prendergast; K. Gavin

    2014-01-01

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

  7. Bridging physics and biology teaching through modeling

    Science.gov (United States)

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

    2014-05-01

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

  8. Three-way switching in a cyanide-bridged [CoFe] chain

    Science.gov (United States)

    Hoshino, Norihisa; Iijima, Fumichika; Newton, Graham N.; Yoshida, Norifumi; Shiga, Takuya; Nojiri, Hiroyuki; Nakao, Akiko; Kumai, Reiji; Murakami, Youichi; Oshio, Hiroki

    2012-11-01

    Bistable compounds that exist in two interchangeable phases under identical conditions can act as switches under external stimuli. Among such switchable materials, coordination complexes have energy levels (or phases) that are determined by the electronic states of their constituent metal ions and ligands. They can exhibit multiple bistabilities and hold promise in the search for multifaceted materials that display different properties in different phases, accessible through the application of contrasting external stimuli. Molecular systems that exhibit both thermo- and photoinduced magnetic bistabilities are excellent candidates for such systems. Here we describe a cyanide-bridged [CoFe] one-dimensional chiral coordination polymer that displays both magnetic and electric bistabilities in the same temperature range. Both the electric and magnetic switching probably arise from the same electron-transfer coupled spin-transition phenomenon, which enables the reversible conversion between an insulating diamagnetic phase and either a semiconducting paramagnetic (thermoinduced) or a type of ferromagnetic single-chain magnet (photoinduced) state.

  9. Finding the lost arches of the Medieval Avignon's Bridge (Avignon, Provence, South France): a geoarchaeological approach

    Science.gov (United States)

    Ghilardi, M.; Vella, M. A.; Hermitte, D.; Parisot, J. C.; Dussouillez, P.; Fleury, T. J.; Provansal, M.; Delanghe-Sabatier, D.; Demory, F.; Mathé, P. E.; Quesnel, Y.; Danos, S.; Balossino, S.; Delpey, Y.; Hartmann-Virnich, A.; Berthelot, M.

    2012-04-01

    Acoustic camera techniques) together with geophysical prospections (Electric Resistivity Tomography and Magnetic Cartography methods) in order to reveal potential locations of arches within the modern Rhone River channels (Villeneuve Lez Avignon and Avignon's arms) and on the Barthelasse fluvial island. In addition historical sources, such as maps, were integrated together with the acquired geophysical data in a Geographic Information System in order to identify possible remnant arches. Finally, boreholes have been drilled and later linked with the geophysical data, to reveal the alluvial litho-stratigraphy and describe the geomorphic the changes in the fluvial system. Results clearly reveal the presence of large carved stone accumulation at a regular interval in the Villeneuve-Lez-Avignon and Avignon's branches. An interpretation concerning the shape of the Saint Bénézet Bridge, in a changing morpho-dynamic context, can be assumed and fits well with various sketches and maps established from the 16th to the 17th Centuries. Keywords: Rhone River, Saint Bénézet Medieval Bridge, city of Avignon, Geoarchaeology, Fluvial palaeoenvironments, bathymetric surveys, geophysics, coring, building techniques, building archaeology, iconography

  10. Photomagnetism in cyano-bridged bimetal assemblies.

    Science.gov (United States)

    Ohkoshi, Shin-ichi; Tokoro, Hiroko

    2012-10-16

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

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

    International Nuclear Information System (INIS)

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

  12. Study of behavior of hanging bridges type Pony

    OpenAIRE

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

    2010-01-01

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

  13. Efficient photoinduced energy transfer mediated by aromatic homoconjugated bridges

    NARCIS (Netherlands)

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

    2010-01-01

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

  14. Fatigue assessment for deck plates in orthotropic bridge decks

    NARCIS (Netherlands)

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

    2012-01-01

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

  15. Comparison of Ferry Boat and Highway Bridge Energy Use

    Directory of Open Access Journals (Sweden)

    Wayne D. Cottrell

    2011-01-01

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

  16. Very High Frequency Half Bridge DC/DC Converter

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  17. Multidisciplinary health monitoring of a steel bridge deck structure

    NARCIS (Netherlands)

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

    2013-01-01

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

  18. Assessment of the Reliability Profiles for Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

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

  19. GOOD HEALTH AND THE BRIDGING OF STRUCTURAL HOLES.

    Science.gov (United States)

    Cornwell, Benjamin

    2009-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    王军; 施发义; 陈胖胖

    2015-01-01

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

  1. Introduction of New Book: Scouring at Bridge Crossings

    Institute of Scientific and Technical Information of China (English)

    Hongwu Zhang

    2005-01-01

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

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

    Science.gov (United States)

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

    2005-01-01

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

  3. Review on antibacterial characteristics of bridge engineering biomaterials.

    Science.gov (United States)

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

    2016-01-01

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

  4. The South Carolina bridge-scour envelope curves

    Science.gov (United States)

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

    2016-09-30

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

  5. Wind Tunnel Testing of Active Control System for Bridges

    DEFF Research Database (Denmark)

    Hansen, Henriette I.; Thoft-Christensen, Palle

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

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

    NARCIS (Netherlands)

    Kolstein, M.H.

    2007-01-01

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

  7. Structural health monitoring of an existing PC box girder bridge with distributed HCFRP sensors in a destructive test

    International Nuclear Information System (INIS)

    The application of hybrid carbon fiber reinforced polymer (HCFRP) sensors was addressed to monitor the structural health of an existing prestressed concrete (PC) box girder bridge in a destructive test. The novel HCFRP sensors were fabricated with three types of carbon tows in order to realize distributed and broad-based sensing, which is characterized by long-gauge length and low cost. The HCFRP sensors were bonded on the bottom and side surfaces of the existing bridge to monitor its structural health. The gauge lengths of the sensors bonded on the bottom and side surfaces were 1.5 m and 1.0 m, respectively. The HCFRP sensors were distributed on the bridge for two purposes. One was to detect damage and monitor the structural health of the bridge, such as the initiation and propagation of new cracks, strain distribution and yielding of steel reinforcements. The other purpose was to monitor the propagation of existing cracks. The good relationship between the change in electrical resistance and load indicates that the HCFRP sensors can provide actual infrastructures with a distributed damage detection and structural health monitoring system. Corrections were made to this article on 13 May 2008. The corrected electronic version is identical to the print version

  8. Electricity supply

    International Nuclear Information System (INIS)

    In the 1960s and early 1970s, nuclear power plants offered economic and environmental advantages over coal plants; most were completed on time and at reasonable cost and still operate today, providing economical, reliable electricity. In the 1970s, a series of events, beginning with the 1973-74 recession and culminating with the Three Mile Island accident, adversely affected the nuclear industry. This report discusses how reviving the nuclear option requires increased public acceptance and reduced financial risks. The public's concerns about safety need to be allayed through the safe, efficient operation of current plants and improved designs. In addition, escalating costs-stemming in part form an outmoded licensing process and unanticipated actions by state agencies and public interest groups-must be alleviated

  9. Application of Artificial Intelligence for Bridge Deterioration Model.

    Science.gov (United States)

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

    2015-01-01

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

  10. Anthropogenic sources stimulate resonance of a natural rock bridge

    Science.gov (United States)

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

    2016-09-01

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

  11. Vibration characteristics and damage detection in a suspension bridge

    Science.gov (United States)

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

    2016-08-01

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

  12. Solving Topological and Geometrical Constraints in Bridge Feature Model

    Institute of Scientific and Technical Information of China (English)

    PENG Weibing; SONG Liangliang; PAN Guoshuai

    2008-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2002-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-01-01

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

  15. Advanced aerostatic analysis of long-span suspension bridges

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Oguz Gunes

    2012-01-01

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

  17. Vigorous convection in a sunspot granular light bridge

    CERN Document Server

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

    2014-01-01

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

  18. Application of Artificial Intelligence for Bridge Deterioration Model

    Directory of Open Access Journals (Sweden)

    Zhang Chen

    2015-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    刘建成; 顾永宁

    2002-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

  1. EXPERIMENTAL STUDY OF THE MORPHOLOGY OF CEREBRAL BRIDGING VEIN

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

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

  2. Transient response of piles-bridge under horizontal excitation

    Institute of Scientific and Technical Information of China (English)

    朱斌; 陈仁朋; 陈云敏

    2003-01-01

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

  3. Transient response of piles-bridge under horizontal excitation

    Institute of Scientific and Technical Information of China (English)

    朱斌; 陈仁朋; 陈云敏

    2003-01-01

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

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

    OpenAIRE

    Rosa, Simon

    2008-01-01

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

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

    OpenAIRE

    Arsoy, Sami

    2000-01-01

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

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

    OpenAIRE

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

    2004-01-01

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

  7. IceBridge: Bringing a Field Campaign Home

    Science.gov (United States)

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

    2015-12-01

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

  8. Bridging the gap with flipped classroom

    DEFF Research Database (Denmark)

    Selberg, Hanne; Topperzer, Martha

    2016-01-01

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

  9. Bridging Physics and Biology Teaching through Modeling

    CERN Document Server

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

    2013-01-01

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

  10. Bridging Innovation and Curriculum in Higher Education

    DEFF Research Database (Denmark)

    Zhang, Fenzhi; Kolmos, Anette; Du, Xiangyun

    2010-01-01

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

  11. Helping System Engineers Bridge the Peaks

    Science.gov (United States)

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

    2014-01-01

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

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

    OpenAIRE

    Laurendeau, Matthew P.

    2011-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Yongle Li

    2015-01-01

    Full Text Available Compared with medium and small span bridges, very limited attention has been paid on the research of the impact coefficient of long-span railway bridges. To estimate the impact effects of long-span railway bridges subjected to moving vehicles, a real long-span railway cable-stayed bridge is regarded as the research object in this study, and a coupled model of vehicle-bridge system is established. The track irregularities are taken as the system excitation and the dynamic responses of the vehicle-bridge system are calculated. The impact effects on main girder, stayed cable, bearings, and bridge tower are discussed at various vehicle speeds. The results show that different components of the long-span railway cable-stayed bridge have different impact coefficients. Even for each part, the impact coefficient is also different at different local positions. It reveals that the impact coefficients in the actual situation may have significant differences with the related code clauses in the present design codes.

  14. Numerical analysis of dynamic response of vehicle–bridge coupled system on long-span continuous girder bridge

    Directory of Open Access Journals (Sweden)

    Lipeng An

    2016-07-01

    Full Text Available To systematically study the vehicle–bridge coupled dynamic response and its change rule with different parameters, a vehicle model with seven degrees of freedom was built and the total potential energy of vehicle space vibration system was deduced. Considering the stimulation of road roughness, the dynamic response equation of vehicle–bridge coupled system was established in accordance with the elastic system principle of total potential energy with stationary value and the “set-in-right-position” rule. On the basis of the self-compiled Fortran program and bridge engineering, the dynamic response of long-span continuous girder bridge under vehicle load was studied. This study also included the calculation of vehicle impact coefficient, evaluation of vibration comfort, and analysis of dynamic response parameters. Results show the impact coefficient changes with lane number and is larger than the value calculated by the “general code for design of highway bridges and culverts (China”. The Dieckmann index of bridge vibration is also related to lane number, and the vibration comfort evaluation is good in normal conditions. The relevant conclusions from parametric analyses have practical significance to dynamic design and daily operation of long-span continuous girder bridges in expressways. Safety and comfort are expected to improve significantly with further control of the vibration of vehicle–bridge system.

  15. Implementation of a Non-Metallic Reinforced Bridge Deck, Volume 2: Thayer Road Bridge

    OpenAIRE

    Frosch, Robert J.; Pay, Ali Cihan

    2006-01-01

    The primary maintenance problem with bridges in Indiana has been deterioration of the concrete deck which is often related to corrosion of the reinforcing steel. While a corrosion protection system consisting of epoxy-coated reinforcement in combination with 2-1/2 in. of Class C concrete cover has been used in Indiana, research and experience have demonstrated that this system can be compromised. As an alternative solution to the corrosion problem in reinforced concrete, fiber reinforced poly...

  16. Electronic Coupling in [Mo2]-Bridge-[Mo2] Systems with Twisted Bridges.

    Science.gov (United States)

    Zhang, Hong Li; Zhu, Guang Yuan; Wang, Gangyi; Meng, Miao; Liu, Chun Y; Lei, Hao

    2015-12-01

    In order to evaluate the impact of bridge conformation on electronic coupling in donor-bridge-acceptor triad systems, two Mo2 dimers, [Mo2(DAniF)3]2[μ-1,4-{C(O)NH}2-Naph] (1, DAniF = N,N'-di(p-anisyl)formamidinate and Naph = naphthalenyl) and [Mo2(DAniF)3]2[μ-1,4-(CS2)2-2,5-Me2C6H2] (2), have been synthesized and structurally characterized. These two compounds feature a large dihedral angle (>60°) between the central aromatic ring and the plane defined by the Mo-Mo bond vectors, which is distinct from the previously reported phenylene bridged analogues [Mo2(DAniF)3]2[μ-1,4-{C(O)NH}2-ph] (I) and [Mo2(DAniF)3]2[μ-1,4-(CS2)2-C6H4] (II), respectively. Unusual optical behaviors are observed for the mixed-valence (MV) species (1(+) and 2(+)), generated by single-electron oxidation. While 2(+) exhibits a weak intervalence charge transfer (IVCT) absorption band in the near-IR region, the IVCT band is absent in the spectrum of 1(+), which is quite different from what observed for I(+) and II(+). Optical analyses, based on superexchange formalism and Hush model, indicate that, in terms of Robin-Day classification, mixed-valence species 1(+) belongs to the electronically uncoupled Class I and complex 2(+), with Hab = 220 cm(-1), is assigned to the weakly coupled Class II. Together with I(+) and II(+), the four MV complexes complete a transition from Class I to Class II-III borderline as a result of manipulating the geometric topology of the bridge. Given the structural and electronic features for the molecular systems, the impacts of electrostatic interaction (through-space) and electron resonance (through-bond) on electronic coupling are discussed. PMID:26579936

  17. Bridge Management Strategy Based on Extreme User Costs for Bridge Network Condition

    Directory of Open Access Journals (Sweden)

    Ladislaus Lwambuka

    2014-01-01

    Full Text Available This paper presents a practical approach for prioritization of bridge maintenance within a given bridge network. The maintenance prioritization is formulated as a multiobjective optimization problem where the simultaneous satisfaction of several conflicting objectives includes minimization of maintenance costs, maximization of bridge deck condition, and minimization of traffic disruption and associated user costs. The prevalence of user cost during maintenance period is twofold; the first case refers to the period of dry season where normally the traffic flow is diverted to alternative routes usually resurfaced to regain traffic access. The second prevalence refers to the absence of alternative routes which is often the case in the least developed countries; in this case the user cost referred to results from the waiting time while the traffic flow is put on hold awaiting accomplishment of the maintenance activity. This paper deals with the second scenario of traffic closure in the absence of alternative diversion routes which in essence results in extreme user cost. The paper shows that the multiobjective optimization approach remains valid for extreme cases of user costs in the absence of detour roads as often is the scenario in countries with extreme poor road infrastructure.

  18. Development of a numerical model for vehicle-bridge interaction analysis of railway bridges

    Science.gov (United States)

    Kim, Hee Ju; Cho, Eun Sang; Ham, Jun Su; Park, Ki Tae; Kim, Tae Heon

    2016-04-01

    In the field of civil engineering, analyzing dynamic response was main concern for a long time. These analysis methods can be divided into moving load analysis method and moving mass analysis method, and formulating each an equation of motion has recently been studied after dividing vehicles and bridges. In this study, the numerical method is presented, which can consider the various train types and can solve the equations of motion for a vehicle-bridge interaction analysis by non-iteration procedure through formulating the coupled equations for motion. Also, 3 dimensional accurate numerical models was developed by KTX-vehicle in order to analyze dynamic response characteristics. The equations of motion for the conventional trains are derived, and the numerical models of the conventional trains are idealized by a set of linear springs and dashpots with 18 degrees of freedom. The bridge models are simplified by the 3 dimensional space frame element which is based on the Euler-Bernoulli theory. The rail irregularities of vertical and lateral directions are generated by PSD functions of the Federal Railroad Administration (FRA).

  19. Multilevel Inverters for Electric Vehicle Applications

    Energy Technology Data Exchange (ETDEWEB)

    Habetler, T.G.; Peng, F.Z.; Tolbert, L.M.

    1998-10-22

    This paper presents multilevel inverters as an application for all-electric vehicle (EV) and hybrid-electric vehicle (HEV) motor drives. Diode-clamped inverters and cascaded H-bridge inverters, (1) can generate near-sinusoidal voltages with only fundamental frequency switching; (2) have almost no electromagnetic interference (EMI) and common-mode voltage; and (3) make an EV more accessible/safer and open wiring possible for most of an EV'S power system. This paper explores the benefits and discusses control schemes of the cascade inverter for use as an EV motor drive or a parallel HEV drive and the diode-clamped inverter as a series HEV motor drive. Analytical, simulated, and experimental results show the superiority of these multilevel inverters for this new niche.

  20. Bridge Pressure Flow Scour at Clear Water Threshold Condition

    Institute of Scientific and Technical Information of China (English)

    GUO Junke; KERENYI Kornel; PAGAN-ORTIZ Jorge E; FLORA Kevin

    2009-01-01

    Bridge pressure flow scour at clear water threshold condition is studied theoretically and experimentally. The flume experiments reveal that the measured scour profiles under a bridge are more or less 2-dimensional; all the measured scour profiles can be described by two similarity equations, where the horizontal distance is scaled by the deck width while the local scour by the maximum scour depth; the maximum scour position is located just under the bridge about 15% deck width from the downstream deck edge; the scour begins at about one deck width upstream the bridge while the deposition occurs at about 2.5 deck widths downstream the bridge; and the maximum scour depth decreases with increas-ing sediment size, but increases with deck inundation. The theoretical analysis shows that: bridge scour can be divided into three cases, i.e. downstream unsubmerged, partially submerged, and totally submerged. For downstream unsubmerged flows, the maximum bridge scour depth is an open-channel problem where the conventional methods in terms of critical velocity or bed shear stress can be applied; for partially and totally submerged flows, the equilibrium maximum scour depth can be described by a scour and an inundation similarity number, which has been confirmed by experiments with two decks and two sediment sizes. For application, a design and field evaluation procedure with examples is presented, including the maximum scour depth and scour profile.

  1. Seismic response of skewed RC box-girder bridges

    Institute of Scientific and Technical Information of China (English)

    Ahmed Abdel-Mohti; Gokhan Pekcan

    2008-01-01

    It is critical to ensure the functionality of highway bridges after earthquakes to provide access to important facilities.Since the 1971 San Fernando earthquake,there has been a better understanding of the seismic performance of bridges.Nonetheless,there are no detailed guidelines addressing the performance of skewed highway bridges.Several parameters affect the response of skewed highway bridges under both service and seismic loads which makes their behavior complex.Therefore,there is a need for more research to study the effect of skew angle and other related factors on the performance of highway bridges.This paper examines the seismic performance of a three-span continuous concrete box girder bridge with skew angles from 0 to 60 degrees,analytically.Finite element (FE) and simplified beam-stick (BS) models of the bridge were developed using SAP2000.Different types of analysis were considered on both models such as:nonlinear static pushover,and linear and nonlinear time history analyses.A comparison was conducted between FE and BS,different skew angles,abutment support conditions,and time history and pushover analysis.It is shown that the BS model has the capability to capture the coupling due to skew and the significant modes for moderate skew angles.Boundary conditions and pushover load profile are determined to have a major effect on pushover analysis.Pushover analysis may be used to predict the maximum deformation and hinge formation adequately.

  2. Analysis of resonance mechanism and conditions of train bridge system

    Science.gov (United States)

    Xia, H.; Zhang, N.; Guo, W. W.

    2006-11-01

    In this paper, the resonance mechanism and conditions of train-bridge system are investigated through theoretical derivations, numerical simulations and experimental data analyses. The resonant responses of the bridge induced by moving trains are classified into three types according to different resonance mechanisms: the first is related to the periodical actions of moving load series of the vertical weights, lateral centrifugal and wind forces of vehicles; the second is induced by the loading rate of moving load series of vehicles; the third is owing to the periodically loading of the swing forces of the train vehicles excited by track irregularities and wheel hunting movements. The vehicle resonance is induced by the periodical action of regular arrangement of bridge spans and their deflections. The resonant conditions are proposed and the corresponding resonant train speeds are determined. The application scopes of resonance conditions are discussed. The resonance of the train-bridge system is affected by the span, total length, lateral and vertical stiffness of the bridge, the compositions of the train, and the axle arrangements and natural frequencies of the vehicles. The resonant train speeds for some bridges are estimated and are compared with the critical train speeds obtained from the dynamic simulation of train-bridge interaction model or from the field measurements.

  3. Feasibility Study of Micro-Wind Turbines for Powering Wireless Sensors on a Cable-Stayed Bridge

    Directory of Open Access Journals (Sweden)

    Billie F. Spencer

    2012-09-01

    Full Text Available In this study, the feasibility of using micro-wind turbines to power wireless sensors on a cable-stayed bridge is comprehensively investigated. To this end, the wind environment around a bridge onto which a turbine is installed is examined, as is the power consumption of a wireless sensor. Feasible alternators and rotors are then carefully selected to make an effective small wind generator (known as a micro-wind turbine. Using the three specially selected micro-wind turbines, a series of experiments was conducted to find the turbine best able to generate the largest amount of power. Finally, a horizontal-axis micro-wind turbine with a six-blade rotor was combined with a wireless sensor to validate experimentally its actual power-charging capability. It is demonstrated that the micro-wind turbine can generate sufficient electricity to power a wireless sensor under moderate wind conditions.

  4. State-of-the-art of long-span bridge engineering in China

    Institute of Scientific and Technical Information of China (English)

    XIANG Haifan; GE Yaojun

    2007-01-01

    This paper introduces the state-of-the-art of long-span bridge engineering in China with emphases on recent long-span bridge projects,bridge deck configuration and material,design codes of long-span bridges and improvement of aerodynamic performance.The recent long-span bridge projects include thirty-eight completed suspension bridges,cable-stayed and arch bridges with a main span over 400 m,and eighteen major bridges are under construction.The bridge deck configuration and material,with prestressed concrete decks,steel-concrete composite decks and steel box decks together with several popular cross-sections,are presented.The third part briefly outlines four design codes,including static and dynamic design for highway long-span bridges,and the recent engineering experiences gained from several aerodynamic vibration control projects of long-span bridges are shared in the last part.

  5. A simplified fragility analysis of fan type cable stayed bridges

    Institute of Scientific and Technical Information of China (English)

    R. A. Khan; T. K. Datta; S. Ahmad

    2005-01-01

    A simplified fragility analysis of fan type cable stayed bridges using Probabilistic Risk Analysis (PRA)procedure is presented for determining their failure probability under random ground motion. Seismic input to the bridge support is considered to be a risk consistent response spectrum which is obtained from a separate analysis. For the response analysis, the bridge deck is modeled as a beam supported on springs at different points. The stiffnesses of the springs are determined by a separate 2D static analysis of cable-tower-deck system. The analysis provides a coupled stiffness matrix for the spring system. A continuum method of analysis using dynamic stiffness is used to determine the dynamic properties of the bridges .The response of the bridge deck is obtained by the response spectrum method of analysis as applied to multidegree of freedom system which duly takes into account the quasi - static component of bridge deck vibration. The fragility analysis includes uncertainties arising due to the variation in ground motion, material property, modeling, method of analysis,ductility factor and damage concentration effect. Probability of failure of the bridge deck is determined by the First Order Second Moment (FOSM) method of reliability. A three span double plane symmetrical fan type cable stayed bridge of total span 689 m, is used as an illustrative example. The fragility curves for the bridge deck failure are obtained under a number of parametric variations. Some of the important conclusions of the study indicate that (i) not only vertical component but also the horizontal component of ground motion has considerable effect on the probability of failure; (ii) ground motion with no time lag between support excitations provides a smaller probability of failure as compared to ground motion with very large time lag between support excitation; and (iii) probability of failure may considerably increase for soft soil condition.

  6. Biorefinery, the bridge between agriculture and chemistry

    NARCIS (Netherlands)

    Sanders, J.P.M.; Scott, E.L.; Mooibroek, H.

    2005-01-01

    The depletion in fossil feedstocks, increasing oil prices and the ecological problems associated with CO2 emissions are forcing the development of alternative resources for energy (heat and electricity), transport fuels and chemicals: the replacement of fossil resources with CO2 neutral biomass. Whe

  7. Electric Insulation Detection Method for High-voltage Insulators

    Directory of Open Access Journals (Sweden)

    Wang Jiajun

    2013-07-01

    Full Text Available The principle of partial discharge detection is that through partial bridged discharge under high voltage electric field, it detects the inner air-filled cavity of high-voltage insulators. And it is a nondestructive detection method based on discharge magnitude to judge the insulation quality. The detecting system that adopts the partial discharge detection is more rigorous than testing system for electricity products, which must have small discharge capacity and higher sensitivity. This paper describes the principles of partial discharge detection and analysis insulation detection.

  8. Surface salt bridges stabilize the GCN4 leucine zipper.

    OpenAIRE

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

    1998-01-01

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

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

    CERN Document Server

    Callegaro, Luca; Kampik, Marian; Kim, Dan Bee; Ortolano, Massimo; Pourdanesh, Faranak

    2014-01-01

    This paper describes the realization of a two terminal-pair digital impedance bridge and the test measurements performed with it. The bridge, with a very simple architecture, is based on a commercial two-channel digital signal synthesizer and a synchronous detector. The bridge can perform comparisons between impedances having arbitrary phase and magnitude ratio: its balance is achieved automatically in less than a minute. $R$-$C$ comparisons with calibrated standards, at kHz frequency and 100 kohm magnitude level, give ratio errors of the order of $10^{-6}$, with potential for further improvements.

  10. Definition and segmentation of BioMedBridges stakeholders

    OpenAIRE

    Brooksbank, Cath; Alfarez, Deborah

    2014-01-01

    The success of BioMedBridges will depend on outreach and inreach to diverse groups of stakeholders. This deliverable report describes the use of a survey to define the broad stakeholder groups with whom BioMedBridges needs to engage, and to collect information on how the individual ESFRI-BMS RIs currently engage with these groups. We wanted to know who these stakeholders are, how the RIs are currently engaging with them, and what aspects of BioMedBridges the respondents felt we should be cons...

  11. SiC MOSFETs based split output half bridge inverter

    DEFF Research Database (Denmark)

    Li, Helong; Munk-Nielsen, Stig; Beczkowski, Szymon;

    2014-01-01

    . This paper makes the current commutation mechanism and efficiency analysis of half bridge with split output based on SiC MOSFETs. Current commutation process analysis is illustrated together with LTspice simulation and afterwards, verified by the experimental results of a double pulse test circuit with split...... output. The double pulse test shows the devices' current during commutation process and the reduced switching losses of SiC MOSFETs compared to that of the traditional half bridge. The efficiency comparison is presented with experimental results of half bridge power inverter with split output...

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

    DEFF Research Database (Denmark)

    Koss, Holger; Lund, Mia Schou Møller

    2013-01-01

    The accretion of ice on structural bridge cables changes the aerodynamic conditions of the surface and influences hence the acting wind load process. Full-scale monitoring indicates that light precipitation at moderate low temperatures between zero and -5°C may lead to large amplitude vibrations...... of bridge cables under wind action. This paper describes the experimental simulation of ice accretion on a real bridge cable sheet HDPE tube segment (diameter 160mm) and its effect on the aerodynamic load. Furthermore, aerodynamic instability will be estimated with quasi-steady theory using the determined...

  13. Future Trends in Reliability-Based Bridge Management

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

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

  14. A Voltage Mode Memristor Bridge Synaptic Circuit with Memristor Emulators

    Directory of Open Access Journals (Sweden)

    Leon Chua

    2012-03-01

    Full Text Available A memristor bridge neural circuit which is able to perform signed synaptic weighting was proposed in our previous study, where the synaptic operation was verified via software simulation of the mathematical model of the HP memristor. This study is an extension of the previous work advancing toward the circuit implementation where the architecture of the memristor bridge synapse is built with memristor emulator circuits. In addition, a simple neural network which performs both synaptic weighting and summation is built by combining memristor emulators-based synapses and differential amplifier circuits. The feasibility of the memristor bridge neural circuit is verified via SPICE simulations.

  15. Progressive collapse susceptibility of a long span suspension bridge

    DEFF Research Database (Denmark)

    Olmati, Pierluigi; Giuliani, Luisa

    2013-01-01

    should be maintained in case of an accidental hanger detachment. Local damages in bridges, which are characterized by an horizontal load transfer system, may progress along the deck or along the suspension system, as the dynamic overloading of the structural elements immediately adjacent to the failed...... ones may lead to subsequent failures. In suspension bridges, which are characterized by a relatively low continuity of the system, the damage of the deck may favor a collapse standstill, in case of an early detachment of the deck collapsing section. In the paper, a long span suspension bridge is taken...

  16. Fracture resistance on aggregate bridging crack in concrete

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiufang; XU Shilang

    2007-01-01

    Fracture toughening exhibited in quasi-brittle materials such as concrete is often mainly related to the action of aggregate bridging,which leads to the presence of a fracture process zone ahead of stress-free cracks in such materials.In this investigation,the fracture resistance induced by aggregate bridging,denoted by GI-bridging,is the primary focus.In order to quantitatively determine it,a general analytical formula is firstly developed,based on the definition of fracture energy by Hillerborg.After this,we further present the calculated procedures of determining this fracture resistance from the recorded load vs.crack opening displacement curve.Then,both numerical simulations and fracture experiments are performed on concrete three-point bending beams.Utilizing the obtained load against crack opening displacement curve,the value of GI-bridging at any crack extension as well as the change of GI-bridging with the crack extension is examined.It is found that GI-bridging will firstly increase with the development of crack and then stay constant once the initial crack tip opening displacement reaches the characteristic crack opening displacement w0.The effects of material strength and specimen depth on this fracture resistance are also investigated.The results reveal that the values of GI-bridging of different specimens at any crack propagation are strongly associated with the values of fracture energy of specimens.If the values of fracture energy between different specimens are comparable,the differences between GI-bridging are ignored.Instead,if values of fracture energy are different,the GI-bridging will be different.This shows that for specimens with different strengths,GI-bridging will change greatly whereas for specimens that are different in depth,whether GI-bridging exhibits size effect depends on whether the fracture energy of specimens considered in the calculation of GI-bridging is assumed to be a size-dependent material parameter.

  17. The Damage Analysis of Usu Bridge under Seismic Load

    Directory of Open Access Journals (Sweden)

    Jian-Hui Gao

    2014-02-01

    Full Text Available In order to obtain the dynamic response of Usu bridge the compression damage model of concrete materials and the finite element method are used in this study. The frequency and the main vibration mode of Usu bridge are calculated. The damage distribution and the location of maximum damage of concrete structures under the four kinds of seismic load are obtained. The results show that the maximum damage of bridge deck occurs in close to support position, the maximum compression damage of the main tower occurs in the upper tower root place. Therefore, in the construction and maintenance process note the influence of seismic load of in these positions.

  18. Myocardial bridges: their clinical implications and prognostic signs

    International Nuclear Information System (INIS)

    Among 980 consecutive selective coronary angiograms performed, nine patients had myocardial bridges of the left anterior descending (LAD) coronary artery. The overall prevalence of myocardial bridge was 0.92%. Among these patients, three patients had coronary artery disease, while six cases were isolated myocardial muscle bridges. With respect to functional abnormality, three had grade III milking effect, three had grade II and three had grade I milking effect. The indications for coronary angiograms were typical chest pain in seven cases and a typical chest pain in two cases. Their clinical and laboratory investigations are presented with literature review. (author)

  19. A micromechanical bridge-shaped voltage-controlled oscillator

    Institute of Scientific and Technical Information of China (English)

    HAN; Jianqiang; ZHU; Changchun; ZHAO; Hongpo; LIU; Junhua

    2004-01-01

    A novel micromechanical bridge-shaped voltage-controlled oscillator with high Q value was fabricated. The core of this kind of oscillators is an electrothermally excited and piezoresistively detected micromechanical bridge resonator. Its resonance frequency can be adjusted by changing the DC voltage applied to the Wheatstone bridge. Theoretical analysis and experimental data show that its resonance frequency is linear with the square of the DC voltage. The linearity is better than 0.16% and the adjustable frequency range excels 17.15%.

  20. Electric Vehicles in Imperfect Electricity Markets

    OpenAIRE

    Schill, Wolf-Peter

    2011-01-01

    We use a game-theoretic model to analyze the impacts of a hypothetical fleet of plug-in electric vehicles on the imperfectly competitive German electricity market. Electric vehicles bring both additional demand and additional storage capacity to the market. We determine the effects on prices, welfare, and electricity generation for various cases with different players in charge of vehicle operations. Vehicle loading increases generator profits, but decreases consumer surplus in the power mark...

  1. Sectional model test study on vortex-excited resonance of vehicle-bridge system of Shanghai Bridge over Yangtse River

    Institute of Scientific and Technical Information of China (English)

    Li ZHOU; Yaojun GE

    2009-01-01

    It is necessary to study how vehicles influence the vortex-excited resonance of vehicle-bridge systems,because lock-in wind speed is low and vortex-excited resonance is sensitive to any change in the main girder sections. Based on the Shanghai Bridge over the Yangtse River, the vortex-excited resonance of a 1:60 scale sectional model was tested in a TJ-lwind tunnel, with or without vehicles at the attack angle of 0°, + 3 and -3°,respectively. The conversion relationships between the resonant amplitudes of the sectional model and that of the prototype bridge were also established by mode shape correction. The result indicates that: 1) for the bridge with vehicles, the vertical vortex-excited resonance is accom-panied by torsion vibration with the same frequency, and vice versa, 2) the amplitude of vortex-excited resonance of the bridge with vehicles is much larger than that of the bridge without vehicles, and 3) the lock-in wind speed of the vortex-excited resonance becomes smaller due to the disturbance of vehicles. It is obvious that vehicles bring about changes in the aerodynamic shape of the main girder.Therefore, the influence of vehicles on vortex-excited resonance performance of vehicle-bridge systems, in terms of both amplitude and mode, should not be ignored.

  2. Light Bridge in a Developing Active Region. I. Observation of Light Bridge and its Dynamic Activity Phenomena

    CERN Document Server

    Toriumi, Shin; Cheung, Mark C M

    2015-01-01

    Light bridges, the bright structures that divide the umbra of sunspots and pores into smaller pieces, are known to produce wide variety of activity events in solar active regions (ARs). It is also known that the light bridges appear in the assembling process of nascent sunspots. The ultimate goal of this series of papers is to reveal the nature of light bridges in developing ARs and the occurrence of activity events associated with the light bridge structures from both observational and numerical approaches. In this first paper, exploiting the observational data obtained by Hinode, IRIS, and Solar Dynamics Observatory (SDO), we investigate the detailed structure of the light bridge in NOAA AR 11974 and its dynamic activity phenomena. As a result, we find that the light bridge has a weak, horizontal magnetic field, which is transported from the interior by large-scale convective upflow and is surrounded by strong, vertical fields of adjacent pores. In the chromosphere above the bridge, a transient brightening ...

  3. The Electric Car Challenge.

    Science.gov (United States)

    Diehl, Brian E.

    1997-01-01

    Describes the Electric Car Challenge during which students applied methods of construction to build lightweight, strong vehicles that were powered by electricity. The activity required problem solving, sheet metal work, electricity, design, and construction skills. (JOW)

  4. Agricultural Electricity. Electric Motors. Student Manual.

    Science.gov (United States)

    Benson, Robert T.

    Addressed to the student, this manual, which includes supplementary diagrams, discusses the following topics and principles: Electromagnetic fields, electromagnets, parts of an electric motor, determining speed of an electric motor, types of electric motors in common use (split-phase, capacitor, repulsion-induction, three-phase), the electric…

  5. DOE handbook electrical safety

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    Electrical Safety Handbook presents the Department of Energy (DOE) safety standards for DOE field offices or facilities involved in the use of electrical energy. It has been prepared to provide a uniform set of electrical safety guidance and information for DOE installations to effect a reduction or elimination of risks associated with the use of electrical energy. The objectives of this handbook are to enhance electrical safety awareness and mitigate electrical hazards to employees, the public, and the environment.

  6. Electrical engineer's reference book

    CERN Document Server

    Laughton, M A

    1985-01-01

    Electrical Engineer's Reference Book, Fourteenth Edition focuses on electrical engineering. The book first discusses units, mathematics, and physical quantities, including the international unit system, physical properties, and electricity. The text also looks at network and control systems analysis. The book examines materials used in electrical engineering. Topics include conducting materials, superconductors, silicon, insulating materials, electrical steels, and soft irons and relay steels. The text underscores electrical metrology and instrumentation, steam-generating plants, turbines

  7. Electrical safety guidelines

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    The Electrical Safety Guidelines prescribes the DOE safety standards for DOE field offices or facilities involved in the use of electrical energy. It has been prepared to provide a uniform set of electrical safety standards and guidance for DOE installations in order to affect a reduction or elimination of risks associated with the use of electrical energy. The objectives of these guidelines are to enhance electrical safety awareness and mitigate electrical hazards to employees, the public, and the environment.

  8. Bridging the divide between science and journalism.

    Science.gov (United States)

    Van Eperen, Laura; Marincola, Francesco M; Strohm, Jennifer

    2010-01-01

    There are countless reasons nearly every scientist should learn how to communicate effectively with the media, including increased understanding of critical research findings to attract or sustain funding and build new professional partnerships that will further propel forward research. But where do scientists begin? Bridging the Divide between Science and Journalism offers practical tips for any scientist looking to work with the media.Given the traditional and internet-based sources for medical research and healthcare-related news now available, it is imperative that scientists know how to communicate their latest findings through the appropriate channels. The credible media channels are managed by working journalists, so learning how to package vast, technical research in a form that is appetizing and "bite-sized" in order to get their attention, is an art. Reducing years of research into a headline can be extremely difficult and certainly doesn't come naturally to every scientist, so this article provides suggestions on how to work with the media to communicate your findings. PMID:20219123

  9. Harmonic Oscillators as Bridges between Theories

    International Nuclear Information System (INIS)

    Other than scattering problems where perturbation theory is applicable, there are basically two ways to solve problems in physics. One is to reduce the problem to harmonic oscillators, and the other is to formulate the problem in terms of two-by-two matrices. If two oscillators are coupled, the problem combines both two-by-two matrices and harmonic oscillators. This method then becomes a powerful research tool to cover many different branches of physics. Indeed, the concept and methodology in one branch of physics can be translated into another through the common mathematical formalism. It is noted that the present form of quantum mechanics is largely a physics of harmonic oscillators. Special relativity is the physics of the Lorentz group which can be represented by the group of by two-by-two matrices commonly called SL(2, c). Thus the coupled harmonic oscillators can therefore play the role of combining quantum mechanics with special relativity. Both Paul A. M. Dirac and Richard P. Feynman were fond of harmonic oscillators, while they used different approaches to physical problems. Both were also keenly interested in making quantum mechanics compatible with special relativity. It is shown that the coupled harmonic oscillators can bridge these two different approaches to physics

  10. Harmonic Oscillators as Bridges between Theories

    Science.gov (United States)

    Kim, Y. S.; Noz, Marilyn E.

    2005-03-01

    Other than scattering problems where perturbation theory is applicable, there are basically two ways to solve problems in physics. One is to reduce the problem to harmonic oscillators, and the other is to formulate the problem in terms of two-by-two matrices. If two oscillators are coupled, the problem combines both two-by-two matrices and harmonic oscillators. This method then becomes a powerful research tool to cover many different branches of physics. Indeed, the concept and methodology in one branch of physics can be translated into another through the common mathematical formalism. It is noted that the present form of quantum mechanics is largely a physics of harmonic oscillators. Special relativity is the physics of the Lorentz group which can be represented by the group of by two-by-two matrices commonly called SL(2, c). Thus the coupled harmonic oscillators can therefore play the role of combining quantum mechanics with special relativity. Both Paul A. M. Dirac and Richard P. Feynman were fond of harmonic oscillators, while they used different approaches to physical problems. Both were also keenly interested in making quantum mechanics compatible with special relativity. It is shown that the coupled harmonic oscillators can bridge these two different approaches to physics.

  11. Simplified environmental study on innovative bridge structure.

    Science.gov (United States)

    Bouhaya, Lina; Le Roy, Robert; Feraille-Fresnet, Adélaïde

    2009-03-15

    The aim of this paper is to present a simplified life cycle assessment on an innovative bridge structure, made of wood and ultra high performance concrete, which combines mechanical performance with minimum environmental impact. The environmental analysis was conducted from cradle to grave using the Life Cycle Assessment method. It was restricted to energy release and greenhouse gas emissions. Assumptions are detailed for each step of the analysis. For the wood end-of-life, three scenarios were proposed: dumping, burning, and recycling. Results show that the most energy needed is in the production phase, which represents 73.4% of the total amount. Analysis shows that the renewable energy is about 70% of the production energy. Wood, through its biomass CO2, contributes positively to the environmental impact. It was concluded that no scenario can be the winner on both impacts. Indeed, the end-of-life wood recycling gives the best impact on CO2 release, whereas burning wood, despite its remarkable energy impact is the worst. According to the emphasis given to each impact, designers will be able to choose one or the other. PMID:19368215

  12. Cathodic Protection of the Yaquina Bay Bridge

    Energy Technology Data Exchange (ETDEWEB)

    Bullard, Sophie J.; Cramer, Stephen D.; Covino, Bernard S., Jr.; Holcomb, Gordon R.; Russell, James H.; Laylor, H.M.; Cryer, C.B.

    2001-02-01

    The Yaquina Bay Bridge in Newport, Oregon, was designed by Conde B. McCullough and built in 1936. The 3,223-foot (982 m) structure is a combination of concrete arch approach spans and a steel through arch over the shipping channel. Cathodic protection is used to prevent corrosion damage to the concrete arches. The Oregon Department of Transportation (Oregon DOT) installed a carbon anode coating (DAC-85) on two of the north approach spans in 1985. This anode was operated at a current density of 6.6 mA/m2(0.6 mA/ft2). No failure of the conductive anode was observed in 1990, five years after application, or in 2000, 15 years after application. Thermal-sprayed zinc anodes 20 mils (0.5 mm) thick were applied to half the south approach spans beginning in 1990. Thermal-sprayed zinc anodes 15 mils (0.4 mm) thick were applied to the remaining spans in 1996. These anodes were operated at a current density of 2.2 mA/m2(0.2 mA/ft2). In 1999, four zones on the approach spans were included in a two-year field trial of humectants to improve zinc anode performance. The humectants LiNO3 and LiBr were applied to two zones; the two adjacent zones were left untreated as controls. The humectants substantially reduced circuit resistance compared to the controls.

  13. Stargate GTM: Bridging Descriptor and Activity Spaces.

    Science.gov (United States)

    Gaspar, Héléna A; Baskin, Igor I; Marcou, Gilles; Horvath, Dragos; Varnek, Alexandre

    2015-11-23

    Predicting the activity profile of a molecule or discovering structures possessing a specific activity profile are two important goals in chemoinformatics, which could be achieved by bridging activity and molecular descriptor spaces. In this paper, we introduce the "Stargate" version of the Generative Topographic Mapping approach (S-GTM) in which two different multidimensional spaces (e.g., structural descriptor space and activity space) are linked through a common 2D latent space. In the S-GTM algorithm, the manifolds are trained simultaneously in two initial spaces using the probabilities in the 2D latent space calculated as a weighted geometric mean of probability distributions in both spaces. S-GTM has the following interesting features: (1) activities are involved during the training procedure; therefore, the method is supervised, unlike conventional GTM; (2) using molecular descriptors of a given compound as input, the model predicts a whole activity profile, and (3) using an activity profile as input, areas populated by relevant chemical structures can be detected. To assess the performance of S-GTM prediction models, a descriptor space (ISIDA descriptors) of a set of 1325 GPCR ligands was related to a B-dimensional (B = 1 or 8) activity space corresponding to pKi values for eight different targets. S-GTM outperforms conventional GTM for individual activities and performs similarly to the Lasso multitask learning algorithm, although it is still slightly less accurate than the Random Forest method.

  14. Technology transfer — bridging space and society

    Science.gov (United States)

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

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

  15. Bridging the Divide between Science and Journalism

    Directory of Open Access Journals (Sweden)

    Marincola Francesco M

    2010-03-01

    Full Text Available Abstract There are countless reasons nearly every scientist should learn how to communicate effectively with the media, including increased understanding of critical research findings to attract or sustain funding and build new professional partnerships that will further propel forward research. But where do scientists begin? Bridging the Divide between Science and Journalism offers practical tips for any scientist looking to work with the media. Given the traditional and internet-based sources for medical research and healthcare-related news now available, it is imperative that scientists know how to communicate their latest findings through the appropriate channels. The credible media channels are managed by working journalists, so learning how to package vast, technical research in a form that is appetizing and "bite-sized" in order to get their attention, is an art. Reducing years of research into a headline can be extremely difficult and certainly doesn't come naturally to every scientist, so this article provides suggestions on how to work with the media to communicate your findings.

  16. Model bridging chimera state and explosive synchronization

    Science.gov (United States)

    Zhang, Xiyun; Bi, Hongjie; Guan, Shuguang; Liu, Jinming; Liu, Zonghua

    2016-07-01

    Global synchronization and partial synchronization are the two distinctive forms of synchronization in coupled oscillators and have been well studied in recent decades. Recent attention on synchronization is focused on the chimera state (CS) and explosive synchronization (ES), but little attention has been paid to their relationship. Here we study this topic by presenting a model to bridge these two phenomena, which consists of two groups of coupled oscillators, and its coupling strength is adaptively controlled by a local order parameter. We find that this model displays either CS or ES in two limits. In between the two limits, this model exhibits both CS and ES, where CS can be observed for a fixed coupling strength and ES appears when the coupling is increased adiabatically. Moreover, we show both theoretically and numerically that there are a variety of CS basin patterns for the case of identical oscillators, depending on the distributions of both the initial order parameters and the initial average phases. This model suggests a way to easily observe CS, in contrast to other models having some (weak or strong) dependence on initial conditions.

  17. A p-quinodimethane-bridged porphyrin dimer.

    Science.gov (United States)

    Zeng, Wangdong; Ishida, Masatoshi; Lee, Sangsu; Sung, Young Mo; Zeng, Zebing; Ni, Yong; Chi, Chunyan; Kim, Dongho; Wu, Jishan

    2013-12-01

    A p-quinodimethane (p-QDM)-bridged porphyrin dimer 1 has been prepared for the first time. An unexpected Michael addition reaction took place when we attempted to synthesize compound 1 by reaction of the cross-conjugated keto-linked porphyrin dimers 8a and 8b with alkynyl/aryl Grignard reagents. Alternatively, compound 1 could be successfully prepared by intramolecular Friedel-Crafts alkylation of the diol-linked porphyrin dimer 14 with concomitant oxidation in air. Compound 1 shows intense one-photon absorption (OPA, λ(max)=955 nm, ε=45400 M(-1) cm(-1)) and a large two-photon absorption (TPA) cross-section (σ((2))(max)=2080 GM at 1800 nm) in the near-infrared (NIR) region due to its extended π-conjugation and quinoidal character. It also exhibits a short singlet excited-state lifetime of 25 ps. The cyclic voltammogram of 1 displays multiple redox waves with a small electrochemical energy gap of 0.86 eV. The ground-state geometry, electronic structure, and optical properties of 1 have been further studied by density functional theory (DFT) calculations and compared with those of the keto-linked dimer 8b. This research has revealed that incorporation of a p-QDM unit into the porphyrin framework had a significant impact on its optical and electronic properties, leading to a novel NIR OPA and TPA chromophore.

  18. Dynamic characteristics analysis of mats of ballasted track on bridge

    Directory of Open Access Journals (Sweden)

    Wu Kaiwei

    2012-11-01

    Full Text Available A complete vehicle-ballasted track-bridge coupling dynamic model is established. A program to analyze dynamic characteristics is also invented, which is the first time to systematically analyze the dynamic characteristics of vehicles, tracks and bridges when using mats under ballast on the rigid foundation of bridge, in China. The results show that:(1 The mats under ballast are able to reduce vibration of the train and the wheel-rail forces by a certain extent, which increase the comforts of passengers.(2 The mats under ballast are able to reduce the stress of ballast, which has a great practical significance on avoiding ballast powdering and reducing maintenance work of ballast. (3 The mats under ballast are able to reduce the vibration of bridges. It has a great significance on avoiding the lateral flow deformation of ballast under dynamic loads, keeping good track geometry to ensure the safety of operation.

  19. THE BRIDGE STRUCTURE TESTS UNDER SLOW MOVING LOAD

    Directory of Open Access Journals (Sweden)

    B. D. Sukhorukov

    2010-03-01

    Full Text Available Peculiarities and advantages of bridge structure tests under slow moving load are pointed out. The calculation algorithms for finding in-situ influence line ordinates based on the results of the tests are proposed.

  20. Bridging the Gap between Instructional Design and Double Loop Learning

    NARCIS (Netherlands)

    Spoelstra, Howard; Rusman, Ellen; Van Bruggen, Jan; Koper, Rob; Matera, Maristella

    2008-01-01

    Spoelstra, H., Rusman, E., Van Bruggen, J., Koper, R., & Matera, M. (2008). Bridging the Gap Between Instructional Design and Double-Loop Learning. International Journal of Web-Based Learning and Teaching Technologies, 3(1), 79-89.

  1. Abnormal oscillation modes in a waning light bridge

    CERN Document Server

    Yuan, Ding

    2016-01-01

    A sunspot acts as a waveguide in response to the dynamics of the solar interior; the trapped waves and oscillations could reveal its thermal and magnetic structures. We study the oscillations in a sunspot intruded by a light bridge, the details of the oscillations could reveal the fine structure of the magnetic topology. We use the Solar Dynamics Observatory/Atmospheric Imaging Assembly data to analyse the oscillations in the emission intensity of light bridge plasma at different temperatures and investigate their spatial distributions. The extreme ultraviolet emission intensity exhibits two persistent oscillations at five-minute and sub-minute ranges. The spatial distribution of the five-minute oscillation follows the spine of the bridge; whereas the sub-minute oscillations overlap with two flanks of the bridge. Moreover, the sub-minute oscillations are highly correlated in spatial domain, however, the oscillations at the eastern and western flanks are asymmetric with regard to the lag time. In the meanwhile...

  2. Re(I) bridged porphyrin dyads, triads and tetrads

    Indian Academy of Sciences (India)

    M Yedukondalu; M Ravikanth

    2011-03-01

    Porphyrin rings containing two meso-pyridyl groups either in cis or trans fashion can be used to construct Re(I) bridged multiporphyrin assemblies. The cis-dipyridyl porphyrins with various porphyrin cores such as N4, N3O, N3S, N2S2 have been used to react with Re(CO)5Cl in THF at refluxing temperature and constructed planar Re(I) bridged porphyrin dyads containing either one type of porphyrin subunit or two types of porphyrin subunits. The trans-dipyridyl porphyrins have been used to construct Re(I) bridged porphyrin squares. The porphyrin dyads have been explored for singlet-singlet energy transfer studies and porphyrin squares have been used for catalysis, chemical sensing, molecular sieving and photocurrent production studies. An overview of synthesis of Re(I) bridged porphyrin dyads, triads and tetrads and their interesting photophysical properties are highlighted in this paper.

  3. Segmental Bridges under Combined Torsion, Bending and Shear

    Institute of Scientific and Technical Information of China (English)

    黄真; 刘西拉

    2003-01-01

    Segmental bridges with unbonded prestressed tendons have some advantages, such as the weather independence and the corrosion protection of prestressing tendons. This paper analyzed the behavior of a prestressed segmental bridge with unbonded tendons under combined loading of torsion, bending and shear. According to the experiment research, a modified skew bending model was developed to calculate the bearing capacity of segmental bridges subjected to combined bending, shear and torsion. The finite element method was used to investigate the deflection behaviors of such structure, also to check the theoretical model. The theoretical and FEM research resuits were compared favorably with the test results from Technical University of Braunschweig, Germany. Finally, suggestion for the design and construction of segmental bridges with external prestressing was made.

  4. Effects of ice accretion on the aerodynamics of bridge cables

    DEFF Research Database (Denmark)

    Demartino, C.; Koss, Holger; Georgakis, Christos T.;

    2015-01-01

    Undesirable wind induced vibrations of bridge cables can occur when atmospheric conditions are such to generate ice accretion. This paper contains the results of an extensive investigation of the effects of ice accretion due to in-cloud icing, on the aerodynamic characteristics of bridge hangers...... of temperature, wind speed and yaw angle of accretion, were reproduced in a climatic wind tunnel, giving rise to different types of accretion. These were chosen such to generate the most common natural ice formations expected to produce bridge cable vibrations. A description of the geometric characteristics...... and stay cables. The aim of this paper is twofold; first, it was investigated the ice accretion process and the final shape of the ice accreted; then the aerodynamics of the ice accreted bridge cables was characterized, and related to the ice shape. Different climatic conditions, i.e. combinations...

  5. Bridge SHM system based on fiber optical sensing technology

    Science.gov (United States)

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

    2015-09-01

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

  6. PS buildings : reinforced concrete structure for shielding "bridge" pillar

    CERN Multimedia

    CERN PhotoLab

    1956-01-01

    The PS ring traverses the region between the experimental halls South and North (buildings Nos 150 and 151) under massive bridge-shaped concrete beams. This pillar stands at the S-W end of the structure.

  7. Road bridges of the ZAR: An annotated photo-essay

    NARCIS (Netherlands)

    Fisher, R.C.; Clarke, N.J.

    2014-01-01

    The Zuid-Afrikaansche Republiek (ZAR) undertook an extensive road and bridge building programme which commenced during the latter half of the 1880s and ended with the effective demise of that independence in 1900.

  8. Mathematical models for suspension bridges nonlinear structural instability

    CERN Document Server

    Gazzola, Filippo

    2015-01-01

    This work provides a detailed and up-to-the-minute survey of the various stability problems that can affect suspension bridges. In order to deduce some experimental data and rules on the behavior of suspension bridges, a number of historical events are first described, in the course of which several questions concerning their stability naturally arise. The book then surveys conventional mathematical models for suspension bridges and suggests new nonlinear alternatives, which can potentially supply answers to some stability questions. New explanations are also provided, based on the nonlinear structural behavior of bridges. All the models and responses presented in the book employ the theory of differential equations and dynamical systems in the broader sense, demonstrating that methods from nonlinear analysis can allow us to determine the thresholds of instability.

  9. Optimal, Generic Planning of Maintenance and Inspection of Steel Bridges

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Faber, M.H.

    2002-01-01

    Fatigue damage is an important deterioration mechanism for steel bridges. This paper describes a simplified and generic approach for reliability and risk based inspection planning of fatigue sensitive structural details. Fatigue sensitive details are categorized according to their loading charact...

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

    Directory of Open Access Journals (Sweden)

    C. Jassadajin

    2013-10-01

    Full Text Available In this work, a resistance measurement is done at both high accuracy and precision using Cryogenic Current Comparator (CCC bridge system [1]. A CCC bridge circuit consists of three parts: coil, current source and detector parts. There are electronic components in the current source of the system. They generate thermal noise in the measurement system. This paper shows the noise reduction in a fractional source of CCC Bridge which is a ramp generator. The bridge receives the voltage signal, which is supplied to a CCC coil to achieve the magnetic flux balance condition inside the superconductorshield, from a null detector. By analysing the noise of the circuit in the fractional part and improving the circuit, it can minimize the noise to obtain a better output of the fractional source for improved accurate and more stability. Finally, the noise can be reduced for a designed bandwidth, a unity noise gain and minimized input resistance in the circuit.

  11. Seismic Performance of Multi-Span RC Railway Bridges

    DEFF Research Database (Denmark)

    Georgakis, Christos; Barrau, Xavier

    2008-01-01

    and fragility curves in relation to PGA. The cost comparisons clearly show that particular bridge types perform better than others economically for specific ground types and expected seismic intensities, even though in some cases they may be expected to suffer larger damages during their lifetime....... with Lead Rubber Bearing (LRB) supports and the laterally fixed continuous deck (CRB) with LRBs. In this paper, the seismic performance of these four types is examined for varying ground types and seismic intensities. For the purposes of comparison, all of the bridges have five spans with identical span...... to increase the performance and reduce the overall bridge cost. Finally, an evaluation of the lifetime bridge costs are made assuming current prices, including costs relating to the damage associated with the expected seismic events. This is accomplished through the use of approximated damage states...

  12. The Tacoma Narrows Bridge Collapse on Film and Video

    Science.gov (United States)

    Olson, Don; Hook, Joseph; Doescher, Russell; Wolf, Steven

    2015-11-01

    This month marks the 75th anniversary of the Tacoma Narrows Bridge collapse. During a gale on Nov. 7, 1940, the bridge exhibited remarkable oscillations before collapsing spectacularly (Figs. 1-5). Physicists over the years have spent a great deal of time and energy studying this event. By using open-source analysis tools and digitized footage of the disaster, physics students in both high school and college can continue in this tradition. Students can watch footage of "Galloping Gertie," ask scientific questions about the bridge's collapse, analyze data, and draw conclusions from that analysis. Students should be encouraged to pursue their own investigations, but the question that drove our inquiry was this: "When physics classes watch modern video showing the oscillations and the free fall of the bridge fragments, are these scenes sped up, slowed down, or at the correct speed compared to what was observed by the eyewitnesses on Nov. 7, 1940?"

  13. Discrete vortex method simulations of aerodynamic admittance in bridge aerodynamics

    DEFF Research Database (Denmark)

    Rasmussen, Johannes Tophøj; Hejlesen, Mads Mølholm; Larsen, Allan;

    The meshless and remeshed Discrete Vortex Method (DVM) has been widely used in academia and by the industry to model two-dimensional flow around bluff bodies. The implementation “DVMFLOW” [1] is used by the bridge design company COWI to determine and visualise the flow field around bridge sections......, and to determine aerodynamic forces and the corresponding flutter limit. A simulation of the three-dimensional bridge responseto turbulent wind is carried out by quasi steady theory by modelling the bridge girder as a line like structure [2], applying the aerodynamic load coefficients found from the current version...... of DVMFLOW in a strip wise fashion. Neglecting the aerodynamic admittance, i.e. the correlation of the instantaneous lift force to the turbulent fluctuations in the vertical velocities, leads to higher response to high frequency atmospheric turbulence than would be obtained from wind tunnel tests....

  14. Discrete vortex method simulations of aerodynamic admittance in bridge aerodynamics

    DEFF Research Database (Denmark)

    Rasmussen, Johannes Tophøj; Hejlesen, Mads Mølholm; Larsen, Allan;

    velocity spectra are found in good agreement with the target spectra. The aerodynamic admittance of the structure is measured by sampling vertical velocities immediately upstream of the structure and the lift forces on the structure. The method is validated against the analytic solution for the admittance......The meshless and remeshed Discrete Vortex Method (DVM) has been widely used in academia and by the industry to model two-dimensional flow around bluff bodies. The implementation “DVMFLOW” [1] is used by the bridge design company COWI to determine and visualise the flow field around bridge sections......, and to determine aerodynamic forces and the corresponding flutter limit. A simulation of the three-dimensional bridge responseto turbulent wind is carried out by quasi steady theory by modelling the bridge girder as a line like structure [2], applying the aerodynamic load coefficients found from the current version...

  15. Hysteretic behavior of prestressed concrete bridge pier with fiber model.

    Science.gov (United States)

    Wang, Hui-li; Feng, Guang-qi; Qin, Si-feng

    2014-01-01

    The hysteretic behavior and seismic characteristics of the prestressed concrete bridge pier were researched. The effects of the prestressed tendon ratio, the longitudinal reinforcement ratio, and the stirrup reinforcement ratio on the hysteretic behavior and seismic characteristics of the prestressed concrete bridge pier have been obtained with the fiber model analysis method. The analysis show some results about the prestressed concrete bridge pier. Firstly, greater prestressed tendon ratio and more longitudinal reinforcement can lead to more obvious pier's hysteresis loop "pinching effect," smaller residual displacement, and lower energy dissipation capacity. Secondly, the greater the stirrup reinforcement ratio is, the greater the hysteresis loop area is. That also means that bridge piers will have better ductility and stronger shear capacity. The results of the research will provide a theoretical basis for the hysteretic behavior analysis of the prestressed concrete pier. PMID:24578635

  16. Bridging Cultures. Transnational Cultural Encounters in the Reception of The Bridge

    DEFF Research Database (Denmark)

    Bondebjerg, Ib

    2017-01-01

    the Nordic noir phenomenon. This article deals with reception of the series in three countries (Denmark, UK and Sweden), through analysis of the demographic profile of audiences and the discourses of reception of the series in selected newspapers and on social media. Such transnational intercultural......The Danish-Swedish crime series The Bridge (2011-) is not just a European co-production involving several national funding sources. It has also created quite an active response among transnational audiences, critics, journalists and creative industry people – further expanding and consolidating...

  17. Accelarated urban landscape: from the Imperator bridge to the Constructor bridge

    OpenAIRE

    Nogueira, Adriana Dantas; Silva, Eder Donizeti da; Giacomet, Maria Clara

    2010-01-01

    This paper approaches the transformation of the urban landscape of Aracaju, a Brazilian Northeast city, located in the coast line, which has, in only 155 years, changed from the condition of village to a city-metropolis. The main case study involves the occurred transformations in a bordering landscape which can be seen from the main river of the city, in where two bridges are located. One of them has been inaugurated at the end of the 19 century and the other one at the beginning of the 2...

  18. Evaluation of an existing bridge`s modal properties using simplified finite element analysis

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, C.R.; Duffey, T.A.

    1996-02-01

    The purpose of this paper is to present results of a simplified approach to the dynamic finite element modeling of composite girder-slab bridges using a single beam element to represent the girder-slab cross section. Dynamic properties calculated with these simplified models are compared to experimental results and results obtained from more detailed shell element models. The method for modeling flexural behavior is first discussed followed by a discussion of modeling torsional behavior. The beam element models accurately calculated the mode shapes of the structure, but the associated resonant frequencies showed some error.

  19. The Roman Bridge: a "double pulley – suture bridges" technique for rotator cuff repair

    Directory of Open Access Journals (Sweden)

    Maffulli Nicola

    2007-12-01

    Full Text Available Abstract Background With advances in arthroscopic surgery, many techniques have been developed to increase the tendon-bone contact area, reconstituting a more anatomic configuration of the rotator cuff footprint and providing a better environment for tendon healing. Methods We present an arthroscopic rotator cuff repair technique which uses suture bridges to optimize rotator cuff tendon-footprint contact area and mean pressure. Results Two medial row 5.5-mm Bio-Corkscrew suture anchors (Arthrex, Naples, FL, which are double-loaded with No. 2 FiberWire sutures (Arthrex, Naples, FL, are placed in the medial aspect of the footprint. Two suture limbs from a single suture are both passed through a single point in the rotator cuff. This is performed for both anchors. The medial row sutures are tied using the double pulley technique. A suture limb is retrieved from each of the medial anchors through the lateral portal, and manually tied as a six-throw surgeon's knot over a metal rod. The two free suture limbs are pulled to transport the knot over the top of the tendon bridge. Then the two free suture limbs that were used to pull the knot down are tied. The end of the sutures are cut. The same double pulley technique is repeated for the other two suture limbs from the two medial anchors, but the two free suture limbs are used to produce suture bridges over the tendon, by means of a Pushlock (Arthrex, Naples, FL, placed 1 cm distal to the lateral edge of the footprint. Conclusion This technique maximizes the advantages of two techniques. On the one hand, the double pulley technique provides an extremely secure fixation in the medial aspect of the footprint. On the other hand, the suture bridges allow to improve pressurized contact area and mean footprint pressure. In this way, the bony footprint in not compromised by the distal-lateral fixation, and it is thus possible to share the load between fixation points. This maximizes the strength of the repair

  20. 23 CFR 650.407 - Application for bridge replacement or rehabilitation.

    Science.gov (United States)

    2010-04-01

    ... Rehabilitation Program § 650.407 Application for bridge replacement or rehabilitation. (a) Agencies participate in the bridge program by conducting bridge inspections and submitting Structure Inventory and... 23 Highways 1 2010-04-01 2010-04-01 false Application for bridge replacement or...