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Sample records for bridges electric

  1. Characterization and electrical modeling of semiconductors bridges

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-01

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

  2. Parameter identification for the electrical modeling of semiconductor bridges.

    Energy Technology Data Exchange (ETDEWEB)

    Gray, Genetha Anne

    2005-03-01

    Semiconductor bridges (SCBs) are commonly used as initiators for explosive and pyrotechnic devices. Their advantages include reduced voltage and energy requirements and exceptional safety features. Moreover, the design of systems which implement SCBs can be expedited using electrical simulation software. Successful use of this software requires that certain parameters be correctly chosen. In this paper, we explain how these parameters can be identified using optimization. We describe the problem focusing on the application of a direct optimization method for its solution, and present some numerical results.

  3. Floating liquid bridge tensile behavior: Electric-field-induced Young's modulus measurements

    Science.gov (United States)

    Teschke, Omar; Mendez Soares, David; Valente Filho, Juracyr Ferraz

    2013-12-01

    A floating bridge is formed spontaneously when high voltage is applied to polar fluids in two capillary tubes that were in contact and then separated. This bridge bends under its own weight, and its bending profile was used to calculate its Young's modulus. For electric field intensities of ˜106 V/m, water bridges exhibit viscoelastic behavior, with Young's moduli of ˜24 MPa; dimethylsulfoxide (DMSO) bridges exhibited Young's moduli of ˜60 kPa. The scheme devised to measure the voltage drop across the water bridge for high voltages applied between the electrodes shows that the bulk water resistance decreases with increasing voltage.

  4. 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...

  5. Hybrid Cascaded H-Bridge Multilevel Inverter Motor Drive DTC Control for Electric Vehicles

    OpenAIRE

    Khoucha, Farid; Mouna Lagoun, Soumia; Marouani, Khoudir; Kheloui, Abdelaziz; BENBOUZID, Mohamed

    2008-01-01

    This paper presents a hybrid cascaded H-bridge multilevel motor drive DTC control scheme for Electric (EV) or Hybrid Electric Vehicles (HEV). The control method is based on Direct Torque Control operating principles. The stator voltage vector reference is computed from the stator flux and torque errors imposed by the flux and torque controllers. This voltage reference is then generated using a hybrid cascaded H-bridge multilevel inverter, where each phase of the inverter can be implemented us...

  6. 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.

  7. 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

  8. 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

  9. Space Vector PWM Control Synthesis for a H-Bridge Drive in Electric Vehicles

    OpenAIRE

    Abdelfatah, Kolli; Béthoux, Olivier; De Bernardinis, Alexandre; Labouré, Eric; Coquery, Gérard

    2013-01-01

    This paper deals with a synthesis of Space Vector PWM control methods applied for a H-bridge inverter feeding a 3-phase Permanent Magnet Synchronous Machine in Electric Vehicle application. First, a short survey of existing power converter architectures, especially those adapted to degraded operating modes, is presented. Standard SVPWM control methods are compared with three innovative ones using EV-drive specifications in the normal operating mode. Then, a rigorous analysis of the margins le...

  10. 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.

  11. Impact of Salt Bridge on Electricity Generation from Hostel Sewage Sludge using Double Chamber Microbial Fuel Cell

    Directory of Open Access Journals (Sweden)

    Anand Parkash

    2015-12-01

    Full Text Available For the economic development and substance of a nation’s economy, energy is used as a prime mover. Future monetary development critically relies upon the long term availability of energy sources that are reasonable, accessible and environmental friendly. Microbial fuel cell represents a total approach to convert bio waste to sustainable and clean energy. In the present study, efforts are made to analyze the impact of salt bridge over the production of electricity. Various designs of salt bridge based MFC is constructed and the efficiency was tabulated. It is concluded that the number of salt bridge has an impact on energy production. The MFC was run for 20 days and readings were noted at regular intervals. In the experiment conducted by employing KCl based salt bridges, the maximum current produced was 2 volts when 1M KCl was used.

  12. Electrical modeling of semiconductor bridge (SCB) BNCP detonators with electrochemical capacitor firing sets

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-11-01

    In this paper the authors describe computer models that simulate the electrical characteristics and hence, the firing characteristics and performance of a semiconductor bridge (SCB) detonator for the initiation of BNCP [tetraammine-cis-bis (5-nitro-2H-tetrazolato-N{sup 2}) cobalt(III) perchlorate]. The electrical data and resultant models provide new insights into the fundamental behavior of SCB detonators, particularly with respect to the initiation mechanism and the interaction of the explosive powder with the SCB. One model developed, the Thermal Feedback Model, considers the total energy budget for the system, including the time evolution of the energy delivered to the powder by the electrical circuit, as well as that released by the ignition and subsequent chemical reaction of the powder. The authors also present data obtained using a new low-voltage firing set which employed an advanced electrochemical capacitor having a nominal capacitance of 350,000 {micro}F at 9 V, the maximum voltage rating for this particular device. A model for this firing set and detonator was developed by making measurements of the intrinsic capacitance and equivalent series resistance (ESR < 10 m{Omega}) of a single device. This model was then used to predict the behavior of BNCP SCB detonators fired alone, as well as in a multishot, parallel-string configuration using a firing set composed of either a single 9 V electrochemical capacitor or two of the capacitors wired in series and charged to 18 V.

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. 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...

  18. 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.

  19. Development of a Bridge Weigh-in-Motion Sensor: Performance Comparison Using Fiber Optic and Electrical Resistance Strain Sensor Systems

    OpenAIRE

    Lydon, Myra; Taylor, S. E.; Robinson, Desmond; O'Brien, Eugene J.; et al.

    2014-01-01

    This paper addresses the problems of effective in situ measurement of the real-time strain for bridge weigh in motion in reinforced concrete bridge structures through the use of optical fiber sensor systems. By undertaking a series of tests, coupled with dynamic loading, the performance of fiber Bragg grating-based sensor systems with various amplification techniques were investigated. In recent years, structural health monitoring (SHM) systems have been developed to monitor bridge deteriorat...

  20. 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

  1. 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.

  2. Bridge? What's a Bridge?

    Science.gov (United States)

    Gutsche, George

    1996-01-01

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

  3. 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.

  4. 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...

  5. 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.

  6. 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 ...

  7. 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.

  8. 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...

  9. Myocardial Bridging.

    Science.gov (United States)

    Yuan, Shi-Min

    2016-02-01

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

  10. 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.

  11. Dual Active Bridge based Battery Charger for Plug-in Hybrid Electric Vehicle with Charging Current Containing Low Frequency Ripple

    OpenAIRE

    Xue, Lingxiao; Díaz López, Daniel; Shen, Zhiyu; Luo, Fang; Mattavelli, Paolo; Boroyevich, Dushan

    2013-01-01

    High power density is strongly preferable for the on-board battery charger of Plug-in Hybrid Electric Vehicle (PHEV). Wide band gap devices, such as Gallium Nitride HEMTs are being explored to push to higher switching frequency and reduce passive component size. In this case, the bulk DC link capacitor of AC-DC Power Factor Correction (PFC) stage, which is usually necessary to store ripple power of two times the line frequency in a DC current charging system, becomes a major barrier on power ...

  12. Coordination polymers based on diiron tetrakis(dithiolato) bridged by alkali metals, electrical bistability around room temperature, and strong antiferromagnetic coupling.

    Science.gov (United States)

    Benmansour, Samia; Delgado, Esther; Gómez-García, Carlos J; Hernández, Diego; Hernández, Elisa; Martin, Avelino; Perles, Josefina; Zamora, Félix

    2015-03-01

    Coordination polymer chains have been formed by the direct reaction between HSC6H2Cl2SH and FeCl3·6H2O in the presence of an aqueous solution of the corresponding alkali-metal hydroxide (M = Li, Na, and K) or carbonate (M = Rb and Cs). The structures consist of dimeric [Fe2(SC6H2Cl2S)4](2-) entities bridged by [M2(THF)4] [M = K (1), Rb (2), and Cs (3); THF = tetrahydrofuran] or {[Na2(μ-H2O)2(THF)2] (5 and 5') units. The smaller size of the lithium atom yields an anion/cation ion-pair molecule, [Li(THF)4]2[Fe2(SC6H2Cl2S)4] (4), in which the dianionic moieties are held together by Cl···Cl interactions. Electrical characterization of these compounds shows a general semiconductor behavior in which the conductivity and activation energies are mainly determined by the M-Cl and M-S bond distances. Compounds 1 and 5' are interesting examples of bistability showing reversible transitions centered at ca. 350 and 290 K with very large hysteresis of ca. 60 and 35 K, respectively. All of these compounds exhibit intradimer strong antiferromagnetic Fe···Fe interactions. PMID:25667965

  13. 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....

  14. 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 ...

  15. 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,...

  16. Theory of water and charged liquid bridges.

    Science.gov (United States)

    Morawetz, K

    2012-08-01

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

  17. 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...

  18. 49 CFR 236.766 - Locking, movable bridge.

    Science.gov (United States)

    2010-10-01

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

  19. 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

  20. Stone bridges

    Czech Academy of Sciences Publication Activity Database

    Drdácký, Miloš; Slížková, Zuzana

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

  1. 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.

  2. 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

    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....

  3. 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。

  4. 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...

  5. 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...

  6. Power Flow Control through a Multi-Level H-Bridge-based Power Converter for Universal and Flexible Power Management in Future Electrical Grids

    DEFF Research Database (Denmark)

    Iov, Florin; Bifaretti, Steffano; Zanchetta, Pericle;

    2008-01-01

    The paper proposes a novel power conversion system for Universal and Flexible Power Management (UNIFLEX-PM) in Future Electricity Network. The structure is based on three AC-DC converters each one connected to a different grid, (representing the main grid and/or various distributed generation...

  7. Microelectronic neural bridging of toad nerves to restore leg function☆

    OpenAIRE

    Shen, Xiaoyan; Wang, Zhigong; Lv, Xiaoying; Huang, Zonghao

    2013-01-01

    The present study used a microelectronic neural bridge comprised of electrode arrays for neural signal detection, functional electrical stimulation, and a microelectronic circuit including signal amplifying, processing, and functional electrical stimulation to bridge two separate nerves, and to restore the lost function of one nerve. The left leg of one spinal toad was subjected to external mechanical stimulation and functional electrical stimulation driving. The function of the left leg of o...

  8. Nanoparticle bridge DNA biosensor

    Science.gov (United States)

    Huang, Hong-Wen

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

  9. 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...

  10. Generalized Gaussian Bridges

    CERN Document Server

    Sottinen, Tommi

    2012-01-01

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

  11. 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...

  12. 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....

  13. 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...

  14. 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...

  15. 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

  16. 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.

  17. 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

  18. Bridge Management Systems:present and future

    OpenAIRE

    Thoft-Christensen, Palle

    1997-01-01

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

  19. Bridging a cultural gap

    Science.gov (United States)

    Leviatan, Talma

    2008-09-01

    There has been a broad wave of change in tertiary calculus courses in the past decade. However, the much-needed change in tertiary pre-calculus programmes—aimed at bridging the gap between high-school mathematics and tertiary mathematics—is happening at a far slower pace. Following a discussion on the nature of the gap and the objectives of a potential bridging programme, this paper aims at demonstrating that the gap can be bridged, by presenting an ongoing modular bridging programme especially designed for the diverse types of student populations in teachers training colleges. We also present here some innovative teaching and assessment methods that were judged essential for the success of these programmes—focusing mainly on the "Questionnaire Based Instruction Method". Finally we suggest directions of follow up and research.

  20. 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...

  1. Wheatstone bridge configuration for evaluation of plasmonic energy transfer

    Science.gov (United States)

    Gosciniak, J.; Mooney, M.; Gubbins, M.; Corbett, B.

    2016-04-01

    We propose an internal (on-chip) Wheatstone bridge configuration to evaluate the efficiency of near-field transducers (NFT) as used in heat-assisted magnetic recording (HAMR). The electric field enhancement between the transducer and the image plane is monitored by measuring the resistance of metal electrodes composing the image plane. The absorption of the enhanced electric field causes an increase in the metal temperature, and thereby, in its resistance whose variation is monitored with an internal Wheatstone bridge which is accurately balanced in the absence of the electric field.

  2. Wheatstone bridge configuration for evaluation of plasmonic energy transfer

    Science.gov (United States)

    Gosciniak, J.; Mooney, M.; Gubbins, M.; Corbett, B.

    2016-01-01

    We propose an internal (on-chip) Wheatstone bridge configuration to evaluate the efficiency of near-field transducers (NFT) as used in heat-assisted magnetic recording (HAMR). The electric field enhancement between the transducer and the image plane is monitored by measuring the resistance of metal electrodes composing the image plane. The absorption of the enhanced electric field causes an increase in the metal temperature, and thereby, in its resistance whose variation is monitored with an internal Wheatstone bridge which is accurately balanced in the absence of the electric field. PMID:27075120

  3. 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...

  4. 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.

  5. 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...

  6. Research on Multidisciplinary Optimization Design of Bridge Crane

    OpenAIRE

    Tong Yifei; Ye Wei; Yang Zhen; Li Dongbo; Li Xiangdong

    2013-01-01

    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 c...

  7. 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.

  8. 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.

  9. Active Control of Suspension Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

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

  10. Building Migratory Bridges

    Science.gov (United States)

    Roy, Michael; Doss, Laurie K.

    2007-01-01

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

  11. 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.

  12. 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

  13. 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...

  14. 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).

  15. Revised Rules for Concrete Bridges

    DEFF Research Database (Denmark)

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

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

  16. 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.

  17. [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

  18. Nasal Bridge Intramuscular Hemangioma

    OpenAIRE

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

    2015-01-01

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

  19. 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...

  20. 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.

  1. 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.

  2. 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...

  3. 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.

  4. Cycling firing method for bypass operation of bridge converters

    Science.gov (United States)

    Zabar, Zivan

    1982-01-01

    The bridge converter comprises a number of switching elements and an electronic logic system which regulated the electric power levels by controlling the firing, i.e., the initiation of the conduction period of the switching elements. Cyclic firing of said elements allows the direct current to bypass the alternating current system with high power factor and negligible losses.

  5. A transmission line bridge for the diagnostics of plasma channels

    Science.gov (United States)

    Pechacek, R. E.; Raleigh, M.; Greig, J. R.; Dwyer, T.; Ehrlich, J.

    1984-03-01

    This paper describes a device for measuring the average electrical conductivity of a long, narrow, cylindrical plasma. Interest in plasmas of this shape originates from two areas of study: the study of electron beam propagation through neutral gas, and the study of long straight electrical discharges for use as a communication antenna. Propagation of an electron beam through a neutral gas produces an ionized channel whose properties and evolution are very important to the propagation of the beam itself. Long straight electrical discharges are created in a channel that is ionized by a pulsed laser beam focused with a long focal length lens, and the properties of the plasma in this channel are important to the propagation of the electrical discharge along with channel. The properties of these plasmas are inferred from changes in the transmission properties of a transmission line placed close to and parallel to the plasma. In this paper an analysis is made of the relation between the bridge output voltage and the conductivity of the perturbing plasma for the case in which the conductivity is very low. In this case all perturbations on the bridge parameters are small, and linear approximations are appropriate. The usefulness of the bridge, however, extends to plasma well above this low conductivity range, although a different set of approximations may be necessary to make the analysis of the experiment tractable. A transmission line bridge is a device for measuring very small changes in the properties of transmission lines.

  6. Monitoring of concrete bridges

    Czech Academy of Sciences Publication Activity Database

    Pirner, Miroš; Urushadze, Shota

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

  7. 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

  8. Nondestructive testing for bridge diagnosis

    International Nuclear Information System (INIS)

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

  9. 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...

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

    DEFF Research Database (Denmark)

    Du, Guangli; Karoumi, Raid

    2013-01-01

    The concept of sustainable construction has attracted an increased attention. Bridge infrastructures and their belonged construction activities consume considerable material and energy, which is responsible for large environmental burdens. However, the environmental assessment of bridges has not...... been integrated into the decision-making process. This paper presents a systematic LCA method for quantifying the environmental impacts for bridges. The comparison study is performed between a reinforced concrete bridge and a steel bridge as an alternative design, with several key maintenance and EOL...... scenarios outlined. LCA study is performed with the ReCiPe methodology with life cycle inventories data from public database. Five selected mid-point level impact categories and the energy consumption are presented. The result shows that the steel bridge has a better environmental performance due to the...

  11. Thermal bridges of modern windows

    DEFF Research Database (Denmark)

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

    2013-01-01

    With its focus on reduced energy consumption, contemporary housing construction requires a highly insulated and airtight building envelope with as few thermal bridges as possible.Windows must be carefully designed, as thermal bridges can lead to surface condensation or mold growth, even if the wi...

  12. Vulnerability of bridges to fire

    DEFF Research Database (Denmark)

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

    2012-01-01

    Even if recent effort in developing methodology and measures for design structures against fire and explosions has been mostly focused on buildings, bridges can also be very sensitive to those actions, as witnesses by some recent bridge accidents, which caused major economic losses and also endan...

  13. Superconductivity in small metal bridges

    International Nuclear Information System (INIS)

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

  14. Bridge Coupler for APT

    CERN Document Server

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

    2000-01-01

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

  15. Half Bridge Inductive Heater

    Directory of Open Access Journals (Sweden)

    Zoltán GERMÁN-SALLÓ

    2015-12-01

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

  16. Implementing a simple vectorial bridge with a digital oscilloscope

    Science.gov (United States)

    Bartiromo, Rosario; De Vincenzi, Mario

    2014-11-01

    We show how to exploit instrumentation available in undergraduate student laboratories to build a simple vectorial bridge. In particular, we take advantage of the ability to read data from a digital oscilloscope with a personal computer and describe an algorithm to obtain an accurate evaluation of the phase difference between two sinusoidal signals. The use of the bridge to characterize components of a high-Q RLC filter is shown to greatly improve the understanding of results in electrical resonance experiments. Direct evidence of dielectric losses, skin currents, and the effect of distributed capacitance is obtained.

  17. 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)

  18. 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.

  19. 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...

  20. 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...

  1. 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]....

  2. 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.

  3. Bridging the urological divide.

    Science.gov (United States)

    Roberts, Robin

    2011-09-23

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

  4. 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.

  5. 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

  6. 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...

  7. 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.

  8. 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

  9. ANGIOGRAPHIC ASPECTS OF MYOCARDIAL BRIDGES

    OpenAIRE

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

    2015-01-01

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

  10. SURGERY OF SYMPTOMATIC MYOCARDIAL BRIDGING

    OpenAIRE

    N. Maghamipour N. Safaei

    2007-01-01

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

  11. 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.

  12. 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.

  13. SURGERY OF SYMPTOMATIC MYOCARDIAL BRIDGING

    Directory of Open Access Journals (Sweden)

    N. Maghamipour N. Safaei

    2007-06-01

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

  14. Wave-current force on bridge foundation

    OpenAIRE

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

    2013-01-01

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

  15. Redundancy Evaluation of Fracture Critical Bridges

    OpenAIRE

    Bapat, Amey Vivek

    2014-01-01

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

  16. 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...

  17. Method and device for current driven electric energy conversion

    DEFF Research Database (Denmark)

    2012-01-01

    Device comprising an electric power converter circuit for converting electric energy. The converter circuit comprises a switch arrangement with two or more controllable electric switches connected in a switching configuration and controlled so as to provide a current drive of electric energy from...... an associated electric source connected to a set of input terminals. This is obtained by the two or more electric swiches being connected and controlled to short-circuit the input terminals during a part of a switching period. Further, a low pass filter with a capacitor and an inductor are provided...... be in different configurations such as half bridge buck, full bridge buck, half bridge boost, or full bridge boost. A current driven conversion is advantageous for high efficient energy conversion from current sources such as solar cells or where a voltage source is connected through long cables, e...

  18. 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.

  19. Bridge Decomposition of Restriction Measures

    CERN Document Server

    Alberts, Tom

    2009-01-01

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

  20. 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...

  1. 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.

  2. 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.

  3. An Expert System for Concrete Bridge Management

    DEFF Research Database (Denmark)

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

    1997-01-01

    The importance of bridge repair versus new bridge construction has risen in recent decades due to high deterioration rates that have been observed in these structures. Budgets both for building new bridges and keeping the existing ones are always limited. To help rational decision-making, bridge ...... information complemented by a knowledge-based interactive system, BRIDGE-1. To optimize management strategies at the headquarters, the BRIDGE-2 module was implemented, including three submodules: inspection strategy, maintenance and repair....... management systems are presently being implemented by bridge authorities in several countries. The prototype of an expert system for concrete bridge management is presented in this paper, with its functionality relying on two modules. The inspection module relies on a periodic acquisition of field...

  4. 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.

  5. 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.

  6. Artropathies that produce osseous bridges

    International Nuclear Information System (INIS)

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

  7. 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 ...

  8. Equilibrium of the floating water bridge: a theoretical and experimental study

    CERN Document Server

    Namin, Reza Montazeri

    2013-01-01

    The floating water bridge is the phenomenon of suspension of a water thread between two beakers with a high voltage applied in between. The equilibrium of this system is investigated assuming both the surface tension force and the tension caused by the electric field within the dielectric material. It was shown experimentally that the deflection of the bridge and its diameter are not independent; this fact was not explained before and in the current paper we show that the effect of surface tension in equilibrium of the bridge would explain it. The deflection of the bridge was calculated theoretically and was experimented, and quantitative agreement was shown while previous theories did not match with the experiments. Also the equilibrium of the bridge in the longitudinal direction is studied, explaining the main effect of the electric field and assuming water as a conductive to calculate the electric field. The non-uniform electric filed is suggested to be an important issue in this case. The conditions at th...

  9. 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...

  10. 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...

  11. 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.

  12. 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...

  13. Bridge spectra of iterated torus knots

    OpenAIRE

    Zupan, Alexander

    2013-01-01

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

  14. Two bridges with composite prestressed tension chord

    OpenAIRE

    Muttoni, Aurelio

    2002-01-01

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

  15. Stabilizer for seismically exposed bridge cranes

    International Nuclear Information System (INIS)

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

  16. 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…

  17. 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...

  18. 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 ...

  19. A floating water bridge produces water with excess charge

    International Nuclear Information System (INIS)

    Excess positive and negative Bjerrum-defect like charge (protonic and ‘aterprotonic’, from ancient Greek ατερ, ‘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. (paper)

  20. 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.

  1. 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....

  2. 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.

  3. The radiography of Swaythling Bridge

    International Nuclear Information System (INIS)

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

  4. Bridging history and social psychology

    DEFF Research Database (Denmark)

    Glaveanu, Vlad Petre; Yamamoto, Koji

    2012-01-01

    This special issue aims to bridge history and social psychology by bringing together historians and social psychologists in an exercise of reading and learning from each other’s work. This interdisciplinary exercise is not only timely but of great importance for both disciplines. Social psycholog......This special issue aims to bridge history and social psychology by bringing together historians and social psychologists in an exercise of reading and learning from each other’s work. This interdisciplinary exercise is not only timely but of great importance for both disciplines. Social...... psychologists can benefit from engaging with historical sources by being able to contextualise their findings and enrich their theoretical models. It is not only that all social and psychological phenomena have a history but this history is very much part of present-day and future developments. On the other...

  5. 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 .

  6. Severe ASR damaged concrete bridges

    DEFF Research Database (Denmark)

    Antonio Barbosa, Ricardo; Gustenhoff Hansen, Søren

    2015-01-01

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

  7. 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.

  8. 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 ...

  9. Inspection Strategies for Concrete Bridges

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

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

  10. Adsorption of polymeric brushes: Bridging

    Science.gov (United States)

    Johner, Albert; Joanny, Jean-François

    1992-04-01

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

  11. 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.

  12. 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

  13. Raman scattering investigation of the water-bridge phenomenon: Some preliminary results

    Directory of Open Access Journals (Sweden)

    Francesco Aliotta

    2010-09-01

    Full Text Available A floating water-bridge is formed if a high-voltage direct current is applied between two beakers filled of chemically pure water. Raman spectra of the OH-stretching region have been obtained at ambient condition of temperature and pressure. These preliminary results seem to indicate that the hydrogen-bond structure is only slightly modified by the presence of the electric field applied to form the floating water-bridge in agreement with recent neutron scattering investigation. In fact, the polarized Raman spectrum of the pure water and of the water-bridge is almost superimposable. We are planning to carry out further spectroscopic analysis, at different thermodynamic conditions, for better understanding the role played by the hydrogen-bond in driving the formation of the floating water-bridge.

  14. 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.

  15. 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.

  16. Bridge pier scour measurement by means of Bragg grating arrays

    Directory of Open Access Journals (Sweden)

    Manzoni S.

    2010-06-01

    Full Text Available This paper deals with a new method to measure scour level at bridge piers. The proposed technique is based on an array of Bragg grating temperature sensors, heated by an electrical circuit. The Bragg gratings in water sense a lower temperature than those buried in the river bed, because of the different heat scattering principles in the two situations. Furthermore the response of each sensor is slower if it is buried in the bed, with respect to the case it is in water. The paper presents laboratory tests, showing the method effectiveness and reliability, and it explains the advantages with respect to other more traditional methodologies to measure scour level.

  17. 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

  18. Fatigue problems of steel bridges

    Czech Academy of Sciences Publication Activity Database

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

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

  19. 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

  20. 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...

  1. 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...

  2. Bridges and wildlife: issues and solutions

    OpenAIRE

    Carey, Marion

    2003-01-01

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

  3. 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 ...

  4. 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.

  5. 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 ...

  6. 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

  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. Measurement of Deflection Line on Bridges

    Science.gov (United States)

    Urban, Rudolf; Štroner, Martin

    2013-12-01

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

  9. 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...

  10. 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...

  11. 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.

  12. Risk assessment of strait crossing bridges

    OpenAIRE

    Forsnes, Mari Krogness

    2015-01-01

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

  13. 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.

  14. 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.

  15. 33 CFR 118.140 - Painting bridge piers.

    Science.gov (United States)

    2010-07-01

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

  16. 23 CFR 650.409 - Evaluation of bridge inventory.

    Science.gov (United States)

    2010-04-01

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

  17. 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...

  18. 33 CFR 118.85 - Lights on vertical lift bridges.

    Science.gov (United States)

    2010-07-01

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

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

    OpenAIRE

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

    2012-01-01

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

  20. 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.

  1. Analysis of Biaxially Stressed Bridge Deck Plates

    DEFF Research Database (Denmark)

    Jönsson, Jeppe; Bondum, Tommi Højer

    The ultimate state analysis of bridge deck plates at the intersection zone between main girders and transverse beams is complicated by biaxial membrane stresses, which may be in compression or tension in either direction depending on the bridge configuration and the specific location. This paper ...

  2. Re-Assessment of Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

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

  3. 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.

  4. Fast response Full Bridge Power Factor Corrector

    OpenAIRE

    Chan, CH; Pong, MH

    1998-01-01

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

  5. 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.

  6. Heavy Vehicles on Minor Highway Bridges

    DEFF Research Database (Denmark)

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

    the results obtained using the numerical models given in details in "Heavy Vehicles on Minor Highway Bridges : dynamic modelling of vehicles and bridges". The models are established using a ordinary vehicle which consists of a 48 t Scania with a 3 axle tractor and a 3 axle trailer, joined in a flexible hinge...

  7. 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.

  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. Optimum Maintenance Strategies for Highway Bridges

    DEFF Research Database (Denmark)

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

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

  11. Modeling walker synchronization on the Millennium Bridge

    Science.gov (United States)

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

    2007-02-01

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

  12. Building bridges … and accelerators

    CERN Multimedia

    2009-01-01

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

  13. 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...

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

    OpenAIRE

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

    2013-01-01

    Light weight orthotropic steel bridge decks have been widely utilized for bridges in seismic zones, movable bridges and long span bridges. In the last three decades, severe problems were reported in relation to asphaltic surfacing materials on orthotropic steel deck bridges. Earlier investigations have shown that the bonding strength of membrane layers to the surrounding materials has a strong influence on the structural response of orthotropic steel bridge decks. The most important requireme...

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

    OpenAIRE

    Widjaja, Matius Andy

    2003-01-01

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

  16. 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.

  17. 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.

  18. Bridge and brick motifs in complex networks

    Science.gov (United States)

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

    2007-04-01

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

  19. Partially entangled states bridge in quantum teleportation

    Science.gov (United States)

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

    2014-10-01

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

  20. Active Control of Long Bridges Using Flaps

    DEFF Research Database (Denmark)

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

    The main problem in designing ultra-long span suspension bridges is flutter. A solution to this problem might be to introduce an active flap control system to increase the flutter wind velocity. The investigated flap control system consists of flaps integrated in the bridge girder so each flap is...... different flap configurations for a bridge section model by using aerodynamic derivatives for a flat plate. The example shows that different flap configurations can either increase or decrease the flutter wind velocity. for optimal flap configurations flutter will not occur....

  1. Human Errors and Bridge Management Systems

    DEFF Research Database (Denmark)

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

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

  2. Building the clinical bridge: an Australian success.

    Science.gov (United States)

    Wallis, Marianne; Chaboyer, Wendy

    2012-01-01

    Nursing effectiveness science includes primary, secondary, and translational, clinically focused research activities which aim to improve patient or client outcomes. It is imperative, for the successful conduct of a program of nursing effectiveness science, that a clinical bridge is established between academic and healthcare service facilities. An Australian example of the development of a robust clinical bridge through the use of jointly funded positions at the professorial level is outlined. In addition, an analysis of the practical application of Lewin's model of change management and the contribution of both servant and transformational leadership styles to the bridge building process is provided. PMID:22577536

  3. 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 ...

  4. Observation of single-electron charging effect in NbN submicron bridges

    International Nuclear Information System (INIS)

    Submicron NbN bridges whose thickness, width and length are 10nm, 100nm and 100-300nm respectively, have been fabricated, and their conduction properties and electrical field effect are measured. The samples having resistances larger than ∼100kΩ exhibit nonlinear I-V characteristics with offset voltage of 2mV∼12mV at 4.2K which are obviously similar to those of the single-electron charging effect in small tunnel junction arrays. The field effect modulation of the junction conductance is observed by applying a voltage to a gate electrode which is made over the NbN bridge. These charging effects are thought to arise from the granular structure of NbN bridges. The simulation result using one-dimensional SET junction arrays coincide well with experimental result. (orig.)

  5. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lien, Wan-Fu [Department of Cultural Heritage Conservation, National Yunlin University of Science and Technology, 123, Section 3, University Road, Touliu, Yunlin 640, Taiwan (China); Huang, Po-Chen [Department of Chemical and Materials Engineering, National Yunlin University of Science and Technology, 123, Section 3, University Road, Touliu, Yunlin 640, Taiwan (China); Tseng, Shi-Chang [Department of Mechanical Engineering, National Yunlin University of Science and Technology, 123, Section 3, University Road, Touliu, Yunlin 640, Taiwan (China); Cheng, Chia-Hsiang; Lai, Shih-Ming [Department of Chemical and Materials Engineering, National Yunlin University of Science and Technology, 123, Section 3, University Road, Touliu, Yunlin 640, Taiwan (China); Liaw, Wen-Chang, E-mail: liawwc@hotmail.com [Department of Chemical and Materials Engineering, National Yunlin University of Science and Technology, 123, Section 3, University Road, Touliu, Yunlin 640, Taiwan (China)

    2012-01-15

    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 Multiplication-Sign 10{sup 3} {Omega}/cm{sup 2} and good mechanical stability as exhibited in ball milling tests.

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

    Science.gov (United States)

    Lien, Wan-Fu; Huang, Po-Chen; Tseng, Shi-Chang; Cheng, Chia-Hsiang; Lai, Shih-Ming; Liaw, Wen-Chang

    2012-01-01

    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.

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

    Science.gov (United States)

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

    2015-12-01

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

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

    OpenAIRE

    R.Samuel Rajesh Babu; Joseph Henry

    2011-01-01

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

  10. 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.

  11. Active aerodynamic stabilisation of long suspension bridges

    DEFF Research Database (Denmark)

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

    2004-01-01

    use of control analysis and design techniques, a linear model of the structural and aerodynamic motion around equilibriun is developed. The model is validated through comparison with finite element calculations and wind tunnel experimental data on the Great Belt East Bridge in Denmark. The developed......The paper describes the addition of actively controlled appendages (flaps) attached along the length of the bridge deck to dampen wind-induced oscillations in long suppension bridges. A novel approach using control systems methods for the analysis of dynamic stability is presented. In order to make...... active control scheme is local in that the flap control signal at a given longitudinal position along the bridge only depends on local motion measurements. The analysis makes use of the Nyquist stability criteria and an anlysis of the sensitivity function for stability analysis. The analysis shows that...

  12. Bridging the Chasm between Policymakers and Educators.

    Science.gov (United States)

    Marshall, Catherine

    1988-01-01

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

  13. 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...

  14. 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...

  15. 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.

  16. 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

  17. Electrical aspects of rainout

    International Nuclear Information System (INIS)

    Rainout commonly denotes the aggregate of phenomena associated with precipitation scavenging of radioactivity from a cloud of nuclear debris that is within a natural rain cloud. (In contrast, the term, washout, is applicable when the nuclear cloud is below the rain cloud and the term, fallout, commonly denotes the direct gravitational settling of contaminated solid material from a nuclear cloud.) Nuclear debris aerosols may be scavenged within natural clouds by a variety of different physical processes which may involve diffusion, convection, impaction, nucleation, phoresis, turbulence, and/or electricity among others. Processes which involve electrical aspects are scrutinized for their susceptibility to the intimate presence of the radioactive-cloud environment. This particular choice of electrical processes is not accidental. Nearly all of the listed processes were examined earlier by Williams. His rough estimates suggested that electrical effects, and to a lesser extent turbulence, could enhance the scavenging of those submicron aerosols which reside in the size-range that bridges the minimum in the scavenging rate coefficient which is commonly called the Greenfield gap. This minimum in the scavenging-rate coefficient is created by the simultaneous reduction of scavenging via diffusion and the reduction of scavenging via inertial impaction. However, Williams omitted the specific influence of a radioactive environment. This report aims to remedy this omission

  18. 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 ...

  19. 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 ...

  20. Acoustic Emission Health Monitoring of Steel Bridges

    OpenAIRE

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

    2014-01-01

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

  1. 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...

  2. 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...

  3. Differential Local Spasticity in Myocardial Bridges

    OpenAIRE

    Angelini, Paolo; Uribe, Carlo; Lozano, Pablo

    2012-01-01

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

  4. Noise measurements in superconducting proximity bridges

    International Nuclear Information System (INIS)

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

  5. 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....

  6. The evaluation of bicycle paths on bridges

    OpenAIRE

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

    2016-01-01

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

  7. 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.

  8. 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 ...

  9. 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...

  10. Inspection Based Evaluation of a Danish Road Bridge

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

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

  11. 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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  13. Precast Pearl-Chain concrete arch bridges

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  14. 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.

  15. 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.

  16. 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...

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

    OpenAIRE

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

    2014-01-01

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

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

    OpenAIRE

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

    1998-01-01

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

  19. Electricity Theory

    International Nuclear Information System (INIS)

    The text book composed of five parts, which are summary of this book, arrangement of electricity theory including electricity nad magnetism, a direct current, and alternating current. It has two dictionary electricity terms for a synonym. The last is an appendix. It is for preparing for test of officer, electricity engineer and fire fighting engineer.

  20. 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 %.

  1. Non-equilibrium two-level system dynamics probed with a biased bridge resonator

    Science.gov (United States)

    Khalil, Moe; Gladchenko, Sergiy; Stoutimore, M. J. A.; Wellstood, F. C.; Osborn, K. D.

    2013-03-01

    We have designed a biased bridge resonator (BBR), which allows us to probe amorphous dielectric films by simultaneously applying a quasi-static electric bias field in addition to a microwave electric field. The BBR is made with a bridge arrangement of capacitors using superconducting aluminum electrodes and operated at millikelvin temperatures. Measurements of a universal amorphous dielectric film at high microwave amplitudes and a sufficiently fast bias field ramp reveals a non-equilibrium dielectric loss equal to its intrinsic steady state value. This phenomenon is explained by a theory which uses the dynamics of charged two-level systems undergoing Landau-Zener transitions to remain in their ground state. We will compare the experimental data to Monte Carlo simulations of the theory which allow for the separate extraction of the dipole moment and the spectral density of two-level systems.

  2. 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

  3. 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.

  4. 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.

  5. Stability Analysis of Diode Bridge Rectifier-Loaded Synchronous Generators Characterized with High Values of Reactances

    OpenAIRE

    Helland, Torunn Husevåg

    2015-01-01

    This thesis concerns the stability of diode bridge rectifier-loaded synchronous generators characterized by large values of synchronous, transient and subtransient reactances in the d- and q-axis, with the possibility of connecting a battery-bank. The synchronous reactances are in the range 2.5-5.5pu. The electrical system studied is installed in two tug-ships using two different types of generators, with different ranges of generator reactances and performance. One of the tugships studie...

  6. 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

  7. Development and Field Testing of a Model to Simulate a Demonstration of Le Chatelier's Principle Using the Wheatstone Bridge Circuit.

    Science.gov (United States)

    Vickner, Edward Henry, Jr.

    An electronic simulation model was designed, constructed, and then field tested to determine student opinion of its effectiveness as an instructional aid. The model was designated as the Equilibrium System Simulator (ESS). The model was built on the principle of electrical symmetry applied to the Wheatstone bridge and was constructed from readily…

  8. Study and Analysis of a Natural Reference Frame Current Controller for a Multi-Level H-Bridge Power Converter

    DEFF Research Database (Denmark)

    Ciobotaru, Mihai; Iov, Florin; Zanchetta, P.;

    2008-01-01

    natural reference frame controller, based on proportional-resonant (PR) technique, for a multi-level H-bridge power converter for Universal and Flexible Power Management in Future Electricity Network. The proposed method is tested in terms of harmonic content in the Point of Common Coupling (PCC), voltage...

  9. 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.

  10. Bridges in the random-cluster model

    Science.gov (United States)

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

    2016-02-01

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

  11. A probabilistic bridge safety evaluation against floods.

    Science.gov (United States)

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

    2016-01-01

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

  12. Natural vibration dynamics of Rainbow Bridge, Utah

    Science.gov (United States)

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

    2015-12-01

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

  13. Useful features in the damage detection of bridges

    International Nuclear Information System (INIS)

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

  14. 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.

  15. 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

  16. Cracking behavior of structural slab bridge decks

    Science.gov (United States)

    Baah, Prince

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

  17. 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...

  18. 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.

  19. 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.

  20. The mechanics of ship impacts against bridges

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup; Zhang, Shengming

    1998-01-01

    information is introduced in a mathematical model for estimation of the return period for collisions with bridge piers and girders. A new mathematical model is thereafter presented for calculation of the energies released for crushing of structures given a specific collision scenario which may include a...... glancing blow between the ship and the bridge structure. This model is based on rigid body mechanics and well suited for inclusion in a probabilistic analysis procedure. Finally, some empirical expressions are presented which relate the energy absorbed by crushing of ship structures to the maximum impact...

  1. Planar Hall effect bridge magnetic field sensors

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  2. 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.

  3. 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

  4. 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

  5. Electric vehicles

    Science.gov (United States)

    1990-03-01

    Quiet, clean, and efficient, electric vehicles (EVs) may someday become a practical mode of transportation for the general public. Electric vehicles can provide many advantages for the nation's environment and energy supply because they run on electricity, which can be produced from many sources of energy such as coal, natural gas, uranium, and hydropower. These vehicles offer fuel versatility to the transportation sector, which depends almost solely on oil for its energy needs. Electric vehicles are any mode of transportation operated by a motor that receives electricity from a battery or fuel cell. EVs come in all shapes and sizes and may be used for different tasks. Some EVs are small and simple, such as golf carts and electric wheel chairs. Others are larger and more complex, such as automobile and vans. Some EVs, such as fork lifts, are used in industries. In this fact sheet, we will discuss mostly automobiles and vans. There are also variations on electric vehicles, such as hybrid vehicles and solar-powered vehicles. Hybrid vehicles use electricity as their primary source of energy, however, they also use a backup source of energy, such as gasoline, methanol or ethanol. Solar-powered vehicles are electric vehicles that use photovoltaic cells (cells that convert solar energy to electricity) rather than utility-supplied electricity to recharge the batteries. These concepts are discussed.

  6. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Science.gov (United States)

    2010-04-01

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

  7. 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,...

  8. 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.

  9. 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.

  10. 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,…

  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. “On a bridge in Berlin”

    DEFF Research Database (Denmark)

    Pihl, Ole Verner

    2013-01-01

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

  13. Health Professions Education: A Bridge to Quality

    Science.gov (United States)

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

    2003-01-01

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

  14. 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...

  15. 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,…

  16. 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/

  17. 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....

  18. 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…

  19. Construction Technology of Long Span Bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    2000-01-01

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

  20. 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.

  1. Circuit bridging of components by smoke

    International Nuclear Information System (INIS)

    Smoke can adversely affect digital electronics; in the short term, it can lead to circuit bridging and in the long term to corrosion of metal parts. This report is a summary of the work to date and component-level tests by Sandia National Laboratories for the Nuclear Regulatory Commission to determine the impact of smoke on digital instrumentation and control equipment. The component tests focused on short-term effects such as circuit bridging in typical components and the factors that can influence how much the smoke will affect them. These factors include the component technology and packaging, physical board protection, and environmental conditions such as the amount of smoke, temperature of burn, and humidity level. The likelihood of circuit bridging was tested by measuring leakage currents and converting those currents to resistance in ohms. Hermetically sealed ceramic packages were more resistant to smoke than plastic packages. Coating the boards with an acrylic spray provided some protection against circuit bridging. The smoke generation factors that affect the resistance the most are humidity, fuel level, and burn temperature. The use of CO2 as a fire suppressant, the presence of galvanic metal, and the presence of PVC did not significantly affect the outcome of these results

  2. 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…

  3. Indirect bridge frequency measurement: an experimental verification

    Czech Academy of Sciences Publication Activity Database

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

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

  4. Building Bridges, Robots, and High Expectations

    Science.gov (United States)

    Bennie, Fiona; Corbett, Charlotte; Palo, Angela

    2015-01-01

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

  5. 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.

  6. 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.

  7. Characteristics of mortars from ancient bridges

    Czech Academy of Sciences Publication Activity Database

    Frankeová, Dita; Slížková, Zuzana; Drdácký, Miloš

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

  8. 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)

  9. Bridging porous Si-C composites with conducting agents for improving battery cycle life

    Science.gov (United States)

    Li, Zhenzhen; Wang, Wei; Li, Zhihu; Qin, Zhihong; Wang, Jun; Liu, Zhaoping

    2015-07-01

    Porous silicon-carbon (Si-C) composites have been considered to be one of the most effective architectures to improve the cycle life of Si based anode because of its native ability to accommodate the large volume change during discharge/charge process. It is found that lots of reported porous Si-C electrodes employed large amount of binder materials to enhance the structural stability which significantly decreased gravimetric capacity of the whole electrode with limited active materials. In this work, without loss of active materials, various conducting agents were used to build electrical bridges between porous Si-C composites, which significantly improved the structural stability and hence the cycle life. Due to the increase of connection possibilities, cycle life of zero-dimensional MCMB bridged electrode reaches 80 cycles with a capacity retention of 80%, and it can be further promoted to 200 cycles for the VGCF bridged electrode and 220 cycles for the rGO bridged electrode. This work paves an effective route to construct stable Si electrode with porous structures as building blocks without the decrease of active materials.

  10. 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...

  11. Seismic Passive Control of Cable-Stayed Bridges

    OpenAIRE

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

    1995-01-01

    A three-dimensional modeling procedure is proposed for cable-stayed bridges with rubber, steel, and lead energy dissipation devices. The passive control technique is investigated by considering the response of bridge models with and without energy dissipation devices. The impact of various design parameters on the seismic response of current and future bridge designs is studied. Appropriate locations and properties of the passive devices can achieve better performance for cable-stayed bridges...

  12. New Philosophy in Steel Bridge Design and Frabrication

    OpenAIRE

    Henkle, David

    2014-01-01

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

  13. 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...

  14. 305 Building 2 ton bridge crane and monorail assembly analysis

    International Nuclear Information System (INIS)

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

  15. 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...

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

    OpenAIRE

    Ozawa, Makoto

    2010-01-01

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

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

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    Improving the dynamics of suspension bridge using active control is discussed in this paper. The main dynamic problem with long suspension bridges is the aeroelastic phenomenon called flutter. Flutter oscillations of a bridge girder is a stability problem and the oscillations are perpendicular to...... the direction of the wind and occur when the bridge is exposed to wind velocity above critical value called the flutter wind velocity Ucr....

  18. 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...

  19. 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 ...

  20. 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...

  1. 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 ...

  2. 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...

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

    DEFF Research Database (Denmark)

    Du, Guangli; Pettersson, Lars; Karoumi, Raid

    2016-01-01

    impact of the construction sector. Life cycle assessment (LCA) is a systematic method for assessing the environmental impact of products and systems, but its application in bridges is scarce. In Swede, most of the bridges are short spans and the type of concrete slab-frame bridge (CFB) accounts...

  4. 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.

  5. Suspension Bridge Flutter for Girder with Separate Control Flaps

    DEFF Research Database (Denmark)

    Huynh, T.; Thoft-Christensen, Palle

    Active vibration control of long span suspension bridge flutter using separated control flaps (SFSC) has shown to increase effectively the critical wind speed of bridges. In this paper, an SFSC calculation based on modal equations of the vertical and torsional motions of the bridge girder includi...

  6. 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...

  7. 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.

  8. A convenient method for detecting electrolyte bridges in multichannel electroencephalogram and event-related potential recordings.

    Science.gov (United States)

    Tenke, C E; Kayser, J

    2001-03-01

    Dense electrode arrays offer numerous advantages over single channel electroencephalogram/event-related potential (EEG/ERP) recordings, but also exaggerate the influence of common error sources arising from the preparation of scalp placements. Even with conventional low density recordings (e.g. 30-channel Electro-Cap), over-application of electrode gel may result in electrolyte leakage and create low impedance bridges, particularly at vertically-aligned sites (e.g. inferior-lateral). The ensuing electrical short produces an artificial similarity of ERPs at neighboring sites that distorts the ERP topography. This artifact is not immediately apparent in group averages, and may even go undetected after visual inspection of the individual ERP waveforms. Besides adding noise variance to the topography, this error source also has the capacity to introduce systematic, localized artifacts (e.g. add or remove evidence of lateralized activity). Electrolyte bridges causing these artifacts can be easily detected by a simple variant of the Hjorth algorithm (intrinsic Hjorth), in which spatial interelectrode distances are replaced by an electrical analog of distance (i.e. the variances of the difference waveforms for all pairwise combinations of electrodes). When a low impedance bridge exists, the Hjorth algorithm identifies all affected sites as flat lines that are readily distinguishable from Hjorth waveforms at unbridged electrodes. PMID:11222978

  9. 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

  10. 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

  11. 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...

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

    Science.gov (United States)

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

    1995-04-14

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

  13. Renovation techniques for fatigue cracked orthotropic steel bridge decks

    OpenAIRE

    de Jong, F.B.P.

    2007-01-01

    This dissertation presents the research into renovation techniques for orthotropic steel bridge decks. These techniques are needed to solve fatigue problems in the decks of these bridges, as several fatigue cracks have been detected in the deck structure of these bridges the last decade. A well-known example of fatigue cracks are those observed in the deck plate of the Van Brienenoord bascule bridge in 1997, at that time a 7 year old bridge. The renovation techniques are part of a proposed ma...

  14. Running Safety of Trains under Vessel-Bridge Collision

    OpenAIRE

    Yongle Li; Jiangtao Deng; Bin Wang; Chuanjin Yu

    2015-01-01

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

  15. 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...

  16. 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 ...

  17. 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.

  18. 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 ...

  19. 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...

  20. Effect of the ac field on a single-molecule magnet bridged between conducting leads

    International Nuclear Information System (INIS)

    We study quantum spin-rotation effects for a single-molecule magnet bridged between two conducting leads in the ac and dc magnetic fields. The Landau-Zener dynamics induced by the magnetic field generates mechanical torque, making the molecule to oscillate. This mechanical motion of the molecule exhibits unique features that can be detected by measuring the electronic tunneling current through the molecule. - Highlights: → Magnetic molecules (MM) have been proposed as ultimate units of magnetic memory. → Several experiments were performed to measure electric current through a single molecule. → We study mechanical vibrations of a MM bridged between two leads in the presence of ac and dc fields. → Through quantum spin-rotation coupling such fields generate mechanical motion of the molecule. → The twist of the molecule can be detected by measuring the tunneling current through the molecule.

  1. 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.

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

    DEFF Research Database (Denmark)

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

    2006-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Chi Hong-Fu

    2013-01-01

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

  4. 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.

  5. Bridge condition assessment using D numbers.

    Science.gov (United States)

    Deng, Xinyang; Hu, Yong; Deng, Yong

    2014-01-01

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

  6. Monitoring of Bridge Dynamics by Radar Interferometry

    Directory of Open Access Journals (Sweden)

    Imrich Lipták

    2014-06-01

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

  7. 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.

  8. 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...

  9. 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...

  10. Stability of suspension bridges in lateral wind

    Czech Academy of Sciences Publication Activity Database

    Malík, Josef

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

  11. 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 .

  12. Does Myocardial Bridging Affect Coronary Hemodynamics?

    OpenAIRE

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

    2013-01-01

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

  13. Bridge Condition Assessment Using D Numbers

    OpenAIRE

    Xinyang Deng; Yong Hu; Yong Deng

    2014-01-01

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

  14. 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...

  15. Weakly prudent self-avoiding bridges

    OpenAIRE

    Bacher, Axel; Beaton, Nicholas,

    2014-01-01

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

  16. 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.

  17. 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.

  18. Monitoring of Bridge Dynamics by Radar Interferometry

    OpenAIRE

    Imrich Lipták; Ján Erdélyi; Peter Kyrinovič; Alojz Kopáčik

    2014-01-01

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

  19. Torsional asymmetry in suspension bridge systems

    Czech Academy of Sciences Publication Activity Database

    Malík, Josef

    2015-01-01

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

  20. Influence of Icing on Bridge Cable Aerodynamics

    DEFF Research Database (Denmark)

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

    2013-01-01

    determination of these force coefficients require a proper simulation of the ice layer occurring under the specific climatic conditions, favouring real ice accretion over simplified artificial reproduction. The work presented in this paper was performed to study the influence of ice accretion on the aerodynamic...... forces of different bridge cables types. The experiments were conducted in a wind tunnel facility capable amongst others to simulate incloud icing conditions....

  1. Influence of vehicles on bridge aeroelastic stability

    Czech Academy of Sciences Publication Activity Database

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

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

  2. 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 ...

  3. Bridging environmental mixtures and toxic effects

    OpenAIRE

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

    2012-01-01

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

  4. 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.

  5. Smart semiconductor bridge (SCB) igniter for explosives

    Science.gov (United States)

    Bickes, R. W., Jr.

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

  6. 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.)

  7. Bony ankylosis following thermal and electrical injury

    International Nuclear Information System (INIS)

    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.)

  8. 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.

  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. 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

  11. 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...

  12. 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.

  13. 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

  14. 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.

  15. Anticipating electrical breakdown in dielectric elastomer actuators

    Science.gov (United States)

    Muffoletto, Daniel P.; Burke, Kevin M.; Zirnheld, Jennifer L.

    2013-04-01

    The output strain of a dielectric elastomer actuator is directly proportional to the square of its applied electric field. However, since the likelihood of electric breakdown is elevated with an increased applied field, the maximum operating electric field of the dielectric elastomer is significantly derated in systems employing these actuators so that failure due to breakdown remains unlikely even as the material ages. In an effort to ascertain the dielectric strength so that stronger electric fields can be applied, partial discharge testing is used to assess the health of the actuator by detecting the charge that is released when localized instances of breakdown partially bridge the insulator. Pre-stretched and unstretched samples of VHB4910 tape were submerged in dielectric oil to remove external sources of partial discharges during testing, and the partial discharge patterns were recorded just before failure of the dielectric sample.

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

    OpenAIRE

    Valenzuela, Matías A.; Casas Rius, Joan Ramon

    2013-01-01

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

  17. 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.

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

    OpenAIRE

    Daniilidi, Christina

    2009-01-01

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

  19. 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...

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. Future Trends in Reliability-Based Bridge Management

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

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

  5. 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.

  6. 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....

  7. 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.

  8. 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. PMID:27294487

  9. 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

  10. 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. ...

  11. 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.

  12. 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.

  13. 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.

  14. Research on Cascaded H-bridge SVG

    OpenAIRE

    Yannan Yu; Rongfeng Yang; Jichi Yan; Chang Qu

    2014-01-01

    Due to the sharp increase of the non-linear loads, the power quality lagged behind the need for an adequate power system. With a fast response, low loss, low output harmonic current, SVG has become the mainstream of dynamic reactive power compensation devices. The paper introduces a multilevel cascaded H-bridge SVG, featured with DSP+FPGA dual-core control unit and fault-tolerant redundant system, which will enhance the reliability and dynamic response, reduce the switching loss and equipment...

  15. Semiconductor bridge, SCB, ignition of energetic materials

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-04-01

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

  16. 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. 

  17. 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.

  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. Life-Cycle Management Strategy on Steel Girders in Bridges

    OpenAIRE

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

    2012-01-01

    The major problems affecting the service life of bridges are related to various factors such as fatigue-sensitive details, increased service loads, corrosion deterioration, and the lack of proper maintenance. Among them, corrosion deterioration and fatigue damages of structures particularly to steel girder bridges are the most common ones. Bridges of different structural forms, at different locations or under different climates, may suffer from various degrees of deterioration. Steel girders ...

  1. Refined fatigue assessment of an existing steel bridge

    OpenAIRE

    Leander, John; Karoumi, Raid

    2015-01-01

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

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

    OpenAIRE

    Bruno Briseghella; Tobia Zordan

    2015-01-01

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

  3. 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 ...

  4. 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...

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

    OpenAIRE

    Prabhas Ranjan; Debasish; Divia Paul

    2015-01-01

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

  6. Abnormal ventricular repolarisation in association with myocardial bridging.

    OpenAIRE

    J.W. DEAN; Mills, P G

    1994-01-01

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

  7. Project of industrial hall with a bridge crane

    OpenAIRE

    Ambrožič, Klemen

    2014-01-01

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

  8. THE MODERN DECISIONS ABOUT CONSTRUCTIONS OF BRIDGE FLOOR

    Directory of Open Access Journals (Sweden)

    I. D. Sakharova

    2010-03-01

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

  9. Post-earthquake Traffic Capacity of Modern Bridges in California

    OpenAIRE

    Terzic, Vesna

    2009-01-01

    Evaluation of the post-earthquake capacity of a bridge to carry self-weight and traffic loads is essential for a safe and timely re-opening of the bridge after an earthquake. Although modern highway bridges in California designed using the Caltrans Seismic Design Criteria are expected to maintain at minimum a gravity load-carrying capacity during both frequent and extreme seismic events, as of now, there are no validated, quantitative guidelines for estimating the remaining load carrying capa...

  10. 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...

  11. Seismic Response Analysis of Continuous Multispan Bridges with Partial Isolation

    OpenAIRE

    Tubaldi, E; Dall’Asta, A.; Dezi, L.

    2015-01-01

    Partially isolated bridges are a particular class of bridges in which isolation bearings are placed only between the piers top and the deck whereas seismic stoppers restrain the transverse motion of the deck at the abutments. This paper proposes an analytical formulation for the seismic analysis of these bridges, modelled as beams with intermediate viscoelastic restraints whose properties describe the pier-isolator behaviour. Different techniques are developed for solving the seismic problem....

  12. Optical fiber sensor methods for nondestructive evaluation of bridges

    OpenAIRE

    Garrett, Tracey Lynette

    1995-01-01

    This report defines a present problem with U.S. bridges and suggests several reasons for bridge infrastructure deterioration and degradation, such as traffic overload, expired life cycles, environmental and operational conditions, and budget cuts. The most commonly used nondestructive evaluation (NDE) methods for determining the health of bridge infrastructure are summarized and compared. Advantages and disadvantages of each NDE technique are provided, and the lack of an adequa...

  13. Using satellites to monitor Severn Bridge structure, UK

    OpenAIRE

    Roberts, GW; Brown, CJ; Tang, X; Ogundipe, O

    2015-01-01

    The Severn Bridge is a large UK suspension bridge. In 2010, a series of field surveys was commissioned to monitor the magnitude and frequencies of the bridge’s movements, through attaching nine dual-frequency survey grade global navigation satellite system receivers on the bridge and two reference satellite receivers adjacent to the structure. The satellite antenna locations and configuration allow the movements of the north cable to be analysed at four locations, as well as the differential ...

  14. 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.

  15. Radial equilibrium lengths of actomyosin cross-bridges in muscle.

    OpenAIRE

    Brenner, B; Xu, S.; Chalovich, J. M.; Yu, L C

    1996-01-01

    Radial equilibrium lengths of the weakly attached, force-generating, and rigor cross-bridges are determined by recording their resistance to osmotic compression. Radial equilibrium length is the surface-to-surface distance between myosin and actin filaments at which attached cross-bridges are, on average, radially undistorted. We previously proposed that differences in the radial equilibrium length represent differences in the structure of the actomyosin cross-bridge. Until now the radial equ...

  16. Impact of Seismic Vulnerability on Bridge Management Systems

    OpenAIRE

    Yue, Yanchao

    2011-01-01

    Motivated by the potential vulnerability of their road infrastructure, many national authorities and local Departments of Transportation are incorporating seismic risk assessment in their management systems. This Dissertation aims to develop methods and tools for seismic risk analysis that can be used in a Bridge Management System (BMS); helping bridge owners to assess the costs of repair, retrofit and replacement of the bridges under their responsibility. More specifically, these tools a...

  17. 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...

  18. Moessbauer study of methylene-bridged ferrocence derivatives

    International Nuclear Information System (INIS)

    The changes in the molecular geometry of trimethylene-bridged ferrocene derivatives were studied on the basis of Moessbauer measurements. Moessbauer measurements of ferrocenes containing four and five carbon bridges demonstrate that these changes were due to the strain caused by the short three-carbon bridge. Moessbauer results for some trimethylene-bridges ferrocenes for which the crystal structures has been established show a linear correlation between the change of the iron to ring distances and the change of the Moessbauer parameters. (author)

  19. 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)

  20. 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.

  1. 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.

  2. Metallicity and Physical Conditions in the Magellanic Bridge

    OpenAIRE

    Lehner, N.; Howk, J. C.; Keenan, Francis; J. V. Smoker

    2008-01-01

    We present a new analysis of the diffuse gas in the Magellanic Bridge (RA>3h) based on HST/STIS E140M and FUSE spectra of 2 early-type stars lying within the Bridge and a QSO behind it. We derive the column densities of HI (from Ly\\alpha), NI, OI, ArI, SiII, SII, and FeII of the gas in the Bridge. Using the atomic species, we determine the first gas-phase metallicity of the Magellanic Bridge, [Z/H]=-1.02+/-0.07 toward one sightline, and -1.7

  3. 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.

  4. 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...

  5. 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.

  6. 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. PMID:26276996

  7. On the effect of nuclear bridge modes on donor-acceptor electronic coupling in donor-bridge-acceptor molecules

    International Nuclear Information System (INIS)

    We report a theoretical study of intra-molecular electronic coupling in a symmetric DBA (donor-bridge-acceptor) complex, in which a donor electronic site is coupled to an acceptor site by way of intervening orbitals of a molecular bridge unit. In the off-resonant (deep tunneling) regime of electronic transport, the lowest unoccupied molecular orbitals (MO's) of the DBA system are split into distinguishable donor/acceptor and bridge orbitals. The effect of geometrical changes at the bridge on the donor/acceptor electronic energy manifold is studied for local stretching and bending modes. It is demonstrated that the energy splitting in the manifold of donor/acceptor unoccupied MOs changes in response to such changes, as assumed in simple McConnell-type models. Limitations of the simple models are revealed where the electronic charging of the bridge orbitals correlates with increasing donor/acceptor orbital energy splitting only for stretching but not for bending bridge modes.

  8. Greengrid Electric

    International Nuclear Information System (INIS)

    This presentation focused on what customers want from a competitive electricity market and what motivates customers to choose a renewable energy product and service. Greengrid Electric, a subsidiary of Enershare Technology Corp., intends to provide the green electricity that they believe customers have wanted for some time. Enershare and Greengrid have been active participants in the electricity restructuring process in Ontario, and have provided input to the Market Design Committee. Once licensed as a retailer, Greengrid intends to be the major provider of green electricity in Ontario. The company will supply a 100 per cent renewable energy product to their wholesale and retail customers. The company is confident that there is a significant niche market in Ontario for selling a green product that has a blend of wind, small hydro (run-of-river or existing dam), solar, and for energy produced from capturing methane gas from municipal landfill sites. Company officials are confident that customers will be willing to pay a premium price for energy if their purchases will lead to environmental improvement

  9. 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.

  10. Shear evaluation of tapered bridge girder panels with steel corrugated webs near the supports of continuous bridges

    OpenAIRE

    Zevallos, E.; Hassanein, M.F.; Real Saladrigas, Esther; Mirambell Arrizabalaga, Enrique

    2016-01-01

    Because of public construction budgets were cut over the last few years, new bridge girders with corrugated webs to reduce the construction costs have become more widely studied and used. In spite that tapered bridge girders with corrugated webs (BGCWs) are used in modern bridges, their shear strength and behaviour rarely exists in literature. Based on available literature, the web of the linearly tapered BGCWs may be divided into three typologies with different structural response to shear f...

  11. Defining displacements of bridges with geodetic methods on an example of a highway bridge Freimann in Germany

    OpenAIRE

    Božič, Saša

    2009-01-01

    These theses discuss a highway bridge Freimann in Germany. This is around 600 m long and up to 40 m wide bridge in Munich. Because of necessary renovation was bridge longitudinal sawn into two parts. This procedure lasted 20 days. Whole length was divided on 20 spans. Discussed are data for length between three successive spans. Work on this area last two days. Measured were seven time cycles. Described is preparation on geodetic survey, course of survey, analyses of results and deformation m...

  12. 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.

  13. Monitoring durability of new concrete bridge decks

    Science.gov (United States)

    Aktan, Haluk M.; Yaman, Ismail O.; Staton, John F.

    2001-08-01

    The ND durability monitoring procedure, which measures the soundness of field concrete, is based on the fundamental relationship between ultrasonic pulse velocity (UPV) and permeability of an elastic medium. An experimental study documented adequate sensitivity between UPV and concrete permeability. The durability monitoring procedure is based on a parameter developed as part of this study and called paste quality loss (PQL) which is computed from the probability density function parameters of ultrasonic pulse velocity measurements taken from standard and field concrete. For PQL computation, measurements taken on standard concrete specimens, which are made from field concrete mixture, are compared to field measurements. The verification tests on 1000 mm x 1500 mm x 230 mm lab-deck specimens indicated that the PQL parameter computed from the UPV measurements as early as the 28th day is a good predictor of soundness. The UPV measurements made at increasing age of concrete very clearly document the rapid loss of soundness of improperly cured concrete decks. Deck replacement projects on three NHS bridges were used in the implementation of durability monitoring by PQL (paste quality loss) evaluation. The respective 56-day PQL's were calculated as 15%, 31% and 9% indicating a significant variability in the three bridges.

  14. 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.

  15. Pyrophosphate-bridged complexes with picomolar toxicity.

    Science.gov (United States)

    Ikotun, Oluwatayo F; Higbee, Elizabeth M; Ouellette, Wayne; Doyle, Robert P

    2009-09-01

    Recently, we have observed the emergence of a new series of pyrophosphate-bridged coordination complexes. Such complexes have been prepared by overcoming the ready hydrolysis of the pyrophosphate moiety. To date, no exploration has been conducted on the cytotoxicity of such complexes. Three pyrophosphate-bridged complexes, namely {[Ni(phen)(2)](2)(mu-P(2)O(7))}.27H(2)O, {[Cu(phen)(H(2)O)](2)(mu-P(2)O(7))}.8H(2)O and {[Co(phen)(2)](2)(mu-P(2)O(7))}.6MeOH, (where phen is 1,10'-phenanthroline) were chosen for their comparative structural similarities and suitable aqueous solubility. Cytotoxicity studies in the adriamycin-resistant ovarian cancer cell line A2780/AD demonstrated highly significant efficacy, with values as low as 160pM for the cobalt complex at 72h. The underlying mechanism for such exceptional toxicity is investigated focusing on DNA interactions, topoisomerase I enzyme inhibition and oxidative stress (followed by intracellular glutathione levels). The role of hydrolysis in uptake and toxicity is also explored (followed by electronic absorption spectroscopy, (31)P NMR, and confocal microscopy) and the complexes are compared to cisplatin controls. Overall a clear picture of the extraordinary toxicity emerged. The results demonstrate a new class of prodrugs with significant potential for future development for the treatment of drug-resistant cancer cell lines. PMID:19666193

  16. 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.

  17. A review of bridge scour monitoring techniques

    Directory of Open Access Journals (Sweden)

    L.J. Prendergast

    2014-04-01

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

  18. 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....... The down-converted signal is re-modulated on to the lightwave and transmit further through the fiber-optic system. In the uplink, both up-and down-conversion are performed by electrical means. Furthermore, we investigate both passive and active wireless transmitters in this work for both downlink and...

  19. 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

  20. 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...... series with DC-link capacitor. This increases power factor (PF) and reduces the total harmonic distortions (THDs) in current at mains. Input currents of the diode bridge which usually show high peak amplitudes are converted into a 120° rectangular shape which ideally results in a total PF of 0.955 and...

  1. 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

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. 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...... welded connections in steel bridges....

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

    Directory of Open Access Journals (Sweden)

    Kevin K. L. So

    2012-01-01

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

  8. Managing concrete bridges: Methods for reducing costs and user inconveniences

    DEFF Research Database (Denmark)

    Goltermann, Per

    2005-01-01

    The paper presents experiences from modern bridge maintenance management, which has been forced to develop new and cost-efficient approaches in order to cope with the increase in overall deterioration of the aging bridge stock, the growing requirements to accessibility and the decreasing budgets...

  9. 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…

  10. 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.

  11. Influence of vehicles on bridge flutter and galloping

    Czech Academy of Sciences Publication Activity Database

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

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

  12. Super-Bridges Suspended Over Carbon Nanotube Cables

    OpenAIRE

    Carpinteri, Alberto; Pugno, Nicola M.

    2008-01-01

    In this paper the new concept of super-bridges, i.e. kilometre-long bridges suspended over carbon nanotube cables, is introduced. The analysis shows that the use of realistic (thus defective) carbon nanotube bundles as suspension cables can enlarge the current limit main span by a factor of 3.

  13. 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...

  14. 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...... roughness, induced charge, electrostatic probes, and partial discharge transients, together with several follow-on aspects. Each topic is introduced and thereafter the progress achieved through the use of a field-theoretical approach is reviewed. Because the topics cover a wide spectrum of conditions......, it is amply demonstrated that such an approach can lead to significant progress in many areas of electrical insulation....

  15. Combined Differential and Static Pressure Sensor based on a Double-Bridged Structure

    DEFF Research Database (Denmark)

    Pedersen, Casper; Jespersen, S.T.; Krog, J.P.; Christensen, C.; Thomsen, Erik Vilain

    2005-01-01

    A combined differential and static silicon microelectromechanical system pressure sensor based on a double piezoresistive Wheatstone bridge structure is presented. The developed sensor has a conventional (inner) bridge on a micromachined diaphragm and a secondary (outer) bridge on the chip...

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

    DEFF Research Database (Denmark)

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

    1998-01-01

    This paper presents an ambient vibration study of the Vestvej Bridge. The bridge is a typically Danish two-span concrete bridge which crosses a highway. The purpose of the study is to perform a pre-investigation of the dynamic behavior to obtain information for the design of a demonstration project...... concerning application of vibration based inspection of bridges. The data analysis process of ambient vribration testing of bridges has traditionally been based on auto and cross spectral densities estimated using an FFT algorithm. In the pre-analysis state the spectral densities are all averaged to obtain...... the averaged spectral densities(ASD). From the ASD the eigenfrequencies of the structure can be identified. This information can be used in the main analysis, where alle modal parameters are extracted from the spectral densities. Due to long cabling and low response levels (small ambient loads) the...

  17. Transient response of piles-bridge under horizontal excitation

    Institute of Scientific and Technical Information of China (English)

    朱斌; 陈仁朋; 陈云敏

    2003-01-01

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

  18. Transient response of piles-bridge under horizontal excitation

    Institute of Scientific and Technical Information of China (English)

    朱斌; 陈仁朋; 陈云敏

    2003-01-01

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

  19. 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.

  20. 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.

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

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

  2. 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.

  3. 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.

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

    DEFF Research Database (Denmark)

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

    This paper presents an ambient vibration study of the Vestvej Bridge. The bridge is a typically Danish two-span concrete bridge which crosses a highway. The purpose of the study is to perform a pre-investigation of the dynamic behavior to obtain information for the design of a demonstration project...... concerning application of vibration based inspection of bridges. The data analysis process of ambient vribration testing of bridges has traditionally been based on auto and cross spectral densities estimated using an FFT algorithm. In the pre-analysis state the spectral densities are all averaged to obtain...... the averaged spectral densities(ASD). From the ASD the eigenfrequencies of the structure can be identified. This information can be used in the main analysis, where alle modal parameters are extracted from the spectral densities. Due to long cabling and low response levels (small ambient loads) the...

  5. 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.

  6. Guanidinium-Induced Denaturation by Breaking of Salt Bridges.

    Science.gov (United States)

    Meuzelaar, Heleen; Panman, Matthijs R; Woutersen, Sander

    2015-12-01

    Despite its wide use as a denaturant, the mechanism by which guanidinium (Gdm(+) ) induces protein unfolding remains largely unclear. Herein, we show evidence that Gdm(+) can induce denaturation by disrupting salt bridges that stabilize the folded conformation. We study the Gdm(+) -induced denaturation of a series of peptides containing Arg/Glu and Lys/Glu salt bridges that either stabilize or destabilize the folded conformation. The peptides containing stabilizing salt bridges are found to be denatured much more efficiently by Gdm(+) than the peptides containing destabilizing salt bridges. Complementary 2D-infrared measurements suggest a denaturation mechanism in which Gdm(+) binds to side-chain carboxylate groups involved in salt bridges. PMID:26490361

  7. SiC MOSFETs based split output half bridge inverter

    DEFF Research Database (Denmark)

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

    2014-01-01

    Body diode of SiC MOSFETs has a relatively high forward voltage drop and still experiences reverse recovery phenomenon. Half bridge with split output aims to decouple both the body diode and junction capacitance of SiC MOSFETs, therefore achieving a reduced switching loss in a bridge configuration....... 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 and...

  8. 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.

  9. 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.

  10. 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 ...

  11. 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.

  12. 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...

  13. 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.

  14. Tsunamis: bridging science, engineering and society.

    Science.gov (United States)

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

    2015-10-28

    Tsunamis are high-impact, long-duration disasters that in most cases allow for only minutes of warning before impact. Since the 2004 Boxing Day tsunami, there have been significant advancements in warning methodology, pre-disaster preparedness and basic understanding of related phenomena. Yet, the trail of destruction of the 2011 Japan tsunami, broadcast live to a stunned world audience, underscored the difficulties of implementing advances in applied hazard mitigation. We describe state of the art methodologies, standards for warnings and summarize recent advances in basic understanding, and identify cross-disciplinary challenges. The stage is set to bridge science, engineering and society to help build up coastal resilience and reduce losses. PMID:26392618

  15. 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...

  16. Aeroelastic Stability of Suspension Bridges using CFD

    DEFF Research Database (Denmark)

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

    2007-01-01

    measured values may lead to erroneous results and CFD simulations may be used for extrapolation into the critical region. The flow analysis serves as preliminary studies for evaluating flutter stability using CFD methods in three dimensions, where the span-wise correlation of vortex separation, skew inflow...... using CFD models and the aeroelastic stability boundary has been successfully determined when comparing two-dimensional flow situations using wind tunnel test data and CFD methods for the flow solution and two-degrees-of-freedom structural models in translation perpendicular to the flow direction and...... the structural deformation. Furthermore, flutter derivatives are evaluated by CFD models using forced motion of a bridge section in a two-dimensional virtual wind tunnel. The parameter region of critical values is shown to be outside measured values. It is shown that a rough extrapolation of the...

  17. 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.

  18. 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...

  19. Electricity from bagasse in Zimbabwe

    International Nuclear Information System (INIS)

    Zimbabwe has suffered electrical power shortages resulting in electrical energy imports rising to between 40% and 50% of total energy needs. Electricity generation capacity has stagnated at around 2000 Megawatts (MWe) since 1985, when two thermal units totaling 440 MWe were completed at Hwange. The effective capacity is 1.75 GWe. The current plan is to increase capacity by installing 600 MWe at Hwange at a cost of at least US $ 600 million. Raising this level of capital is difficult hence over the last 15 years there has been a failure to increase capacity. This article is based on a study of bagasse cogeneration in Zimbabwe and Mauritius conducted over a two-year period. It discusses technology improvements that can be made in the sugar sector to improve process and energy efficiency for the purposes of becoming an independent power producer that supplies power to the grid continuously throughout the year. Power plant investment in the sugar industry offers a bridging and realizable alternative for electricity generation in Zimbabwe. Investment in a 35 MWe bagasse (moisturized fiber left when sugar has been extracted from sugarcane) system would require a capital of about US$ 35 million using modern technology based on experiences in Mauritius and Reunion. A technical and economic evaluation and analysis reveals that bagasse power development is technically and economically feasible if electricity is priced at the long-term marginal cost. At current import prices, financial assistance from the global environment facility and/or the clean development mechanism of the Kyoto protocol would be necessary. The solving of the current political and economic problems in the country would pave the way for attracting a technical partner and development, of bagasse power using domestic and international financing

  20. 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.

  1. 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

  2. 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...

  3. Documenting the Construction of a Plain Concrete Bridge Deck and an Internally Cured Bridge Deck

    OpenAIRE

    Di Bella, Carmelo; Schlitter, John; Carboneau, Neal; Weiss, Jason

    2012-01-01

    Durable and long lasting concrete is important, especially for bridge decks, which are susceptible to premature cracking and corrosion of the reinforcing steel. To increase the durability of the concrete and its service life, many transportation agencies use high-strength concretes. However, high-strength concretes often have problems with early age cracking due to shrinkage. These cracks can then open a path for chloride ions (found in road salts) to reach the reinforcing steel. The results ...

  4. 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

  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. 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...

  7. 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...

  8. 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...

  9. 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.

  10. Control of switched reluctance motors using asymmetric half bridge and full bridge drives

    International Nuclear Information System (INIS)

    This paper investigates the control of current and torque at different speed of the SRM (Switched Reluctance Motor) from the motor constructional properties, mathematical model equations, operating principle and power converter topology. The SRM has gained popularity in industry with the fact that it is simple to construct. The other advantages are its rugged construction, low maintenance cost and ability to operate over a wide speed range at constant power. The merits of SRMs are outshined by its innate torque ripple issue, acoustic noise and above all the requirement of expensive control. This paper also discusses the operation and simulation of SRM along with power drive model. In this paper motor mathematical model is simulated with two conventional power converter topologies, asymmetric half bridge converter-and symmetric full bridge converter. Torque and current relationship is observed to find out which drive is suitable for smooth torque operation and have better current control at different speeds. The apparent cost difference is also discussed and it is found that full bridge drive is more suitable for general purpose solution in industry with bearable increase in cost. (author)

  11. 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.

  12. 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.

  13. Electricity markets

    International Nuclear Information System (INIS)

    The liberalization of the energy sector makes it possible for eligible consumers to choose their suppliers freely. It has led to the development of an electricity wholesale market, where traders daily carry out transactions, either bilaterally ('OTC'), or on Pools or Power Exchanges which reduce the risks by ensuring the 'clearing' between players. From now on, electricity is traded either as a 'spot' product for immediate physical delivery, or as 'derivatives', inspired by the financial markets (forwards, futures, options...). The commercial transactions are made beyond the geographical borders, thanks to the interconnections between countries, even if these are still insufficient to create a single European market. The Transmission System Operators (in France, RTE) have an essential role, by ensuring the continuity and quality of the high and very high voltage grids, and by providing equitable access to the players. (author)

  14. Electricity intensity backstop level to meet sustainable backstop supply technologies

    International Nuclear Information System (INIS)

    The concept of a backstop level of electricity intensity is introduced and illustrated for the highest income economies of the world. The backstop level corresponds with the intensity that would be triggered by applying end-use electricity prices equal to the cost price of a fully sustainable electricity supply. Section 1 of the paper discusses the issue of electricity (also energy) intensity of economies. It is argued that identifying a 'demand for electricity intensity' bridges the gap between the high willingness to pay for electricity services on the one hand and the disinterested attitude of consumers regarding the invisible and impalpable product electricity on the other hand. Assessment of the demand curve for electricity intensity in a cross section of high income OECD countries comes to a long-run price elasticity of almost -1. Section 2 revives Nordhaus' concept of backstop supply technologies for weighing three power sources (fossil, nuclear, and renewable sources) in meeting today's criteria of sustainable backstop technology. Only renewable sources meet the main sustainability criteria, but the economic cost of a fully sustainable electricity supply will be elevated. The closing question of Section 3, that is, whether the countries can afford the high cost of backstop electricity supplies, is answered by indicating what reductions in intensity are required to keep the electricity bills stable. The targeted intensity level is called the backstop level, and provides a fixed point for electricity efficiency policies. The analysis supports the call for comprehensive and enduring tax reform policies

  15. Electricity intensity backstop level to meet sustainable backstop supply technologies

    International Nuclear Information System (INIS)

    The concept of a backstop level of electricity intensity is introduced and illustrated for the highest income economies of the world. The backstop level corresponds with the intensity that would be triggered by applying end-use electricity prices equal to the cost price of a fully sustainable electricity supply. Section 1 of the paper discusses the issue of electricity (also energy) intensity of economies. It is argued that identifying a 'demand for electricity intensity' bridges the gap between the high willingness to pay for electricity services on the one hand and the disinterested attitude of consumers regarding the invisible and impalpable product electricity on the other hand. Assessment of the demand curve for electricity intensity in a cross section of high income OECD countries comes to a long-run price elasticity of almost -1. Section 2 revives Nordhaus' concept of backstop supply technologies for weighing three power sources (fossil, nuclear, and renewable sources) in meeting today's criteria of sustainable backstop technology. Only renewable sources meet the main sustainability criteria, but the economic cost of a fully sustainable electricity supply will be elevated. The closing question of Section 3, that is, whether the countries can afford the high cost of backstop electricity supplies, is answered by indicating what reductions in intensity are required to keep the electricity bills stable. The targeted intensity level is called the backstop level, and provides a fixed point for electricity efficiency policies. The analysis supports the call for comprehensive and enduring tax reform policies. (author)

  16. Light Bridge in a Developing Active Region. II. Numerical Simulation of Flux Emergence and Light Bridge Formation

    CERN Document Server

    Toriumi, Shin; Katsukawa, Yukio

    2015-01-01

    Light bridges, the bright structure dividing umbrae in sunspot regions, show various activity events. In Paper I, we reported on analysis of multi-wavelength observations of a light bridge in a developing active region (AR) and concluded that the activity events are caused by magnetic reconnection driven by magnetconvective evolution. The aim of this second paper is to investigate the detailed magnetic and velocity structures and the formation mechanism of light bridges. For this purpose, we analyze numerical simulation data from a radiative magnetohydrodynamics model of an emerging AR. We find that a weakly-magnetized plasma upflow in the near-surface layers of the convection zone is entrained between the emerging magnetic bundles that appear as pores at the solar surface. This convective upflow continuously transports horizontal fields to the surface layer and creates a light bridge structure. Due to the magnetic shear between the horizontal fields of the bridge and the vertical fields of the ambient pores,...

  17. 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)

  18. 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, ...... solution for the admittance of a turbulent flow past a flat plate [4] and two types of bridge girder sections. A fair agreement is observed for sufficiently low turbulence intensities and sufficient spatial and temporal resolutions.......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...

  19. 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.

  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. Metallicity and Physical Conditions in the Magellanic Bridge

    CERN Document Server

    Lehner, N; Keenan, F P; Smoker, J V

    2008-01-01

    We present a new analysis of the diffuse gas in the Magellanic Bridge (RA>3h) based on HST/STIS E140M and FUSE spectra of 2 early-type stars lying within the Bridge and a QSO behind it. We derive the column densities of HI (from Ly\\alpha), NI, OI, ArI, SiII, SII, and FeII of the gas in the Bridge. Using the atomic species, we determine the first gas-phase metallicity of the Magellanic Bridge, [Z/H]=-1.02+/-0.07 toward one sightline, and -1.7<[Z/H]<-0.9 toward the other one, a factor 2 or more smaller than the present-day SMC metallicity. Using the metallicity and N(HI), we show that the Bridge gas along our three lines of sight is ~70-90% ionized, despite high HI columns, logN(HI)=19.6-20.1. Possible sources for the ongoing ionization are certainly the hot stars within the Bridge, hot gas (revealed by OVI absorption), and leaking photons from the SMC and LMC. From the analysis of CII*, we deduce that the overall density of the Bridge must be low (<0.03-0.1 cm^-3). We argue that our findings combined ...

  2. 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.

  3. 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...

  4. Study of remaining fatigue life of Brazilian concrete bridges

    OpenAIRE

    Rodrigues, J. Fernando; Almeida, Pedro A.O.; Casas Rius, Joan Ramon

    2010-01-01

    Brazilian roadway bridges had their dynamics effects measured under a structural identification program. Data collected from the tests show that dynamic effects due to traffic can be higher than that produced by a 450 kN lorry, specified in the Standard for design of concrete bridges in Brazil. This fact can affect the fatigue performance of bridge structures in face of 100 years-life required on most current codes. So in this paper a parametric study on the fatigue life time of short-span...

  5. Application of Economic Indicators to Asses the Bridges of Rehablitation

    Directory of Open Access Journals (Sweden)

    Pitoňák Martin

    2015-05-01

    Full Text Available The aim of this paper is to point out the advantage of Cost Benefit Analysis (CBA and its economic indicators to assess a rehabilitation of bridges. The paper includes short example of assessment of the project economic efficiency in which economic indicators are applied in order to evaluate of two technology project variants of bridge object rehabilitation. It quantifies and compares the economic results of alternative 1 with the monolithic prestress construction and alternative 2, with the composite steel - concrete bridge. The contribution reflects the current practice of economic analysis recommended by the Ministry of Transport, Construction and Regional Development.

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    Prabhas Ranjan

    2015-08-01

    Full Text Available Out of nine hundred and eighty seven (987 coronary angiogram reports , in the present study we analysed the prevalence and distribution of bridging segments. The co - relation of these tunnelled segments with diseased and non - diseased coronary arteries and cardiac dominance were also assessed. Myocardial bridging was exclusively confined to LAD predominantly in the midsegmentG of nondiseased arteries in right dominant circulation. Although bridging provides an atheroprotective milieu , it even h arboured atherosclerosis proximal to it. Significantly altering coronary macro and micromechanics it plays a significant role behind genesis of coronary ischemia and its management.

  8. Multiple Myocardial Bridges in a Patient with Hypertrophic Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Tolga Demir

    2016-02-01

    Full Text Available Myocardial bridging is a rare congenital anomaly. It is almost always confined to the left anterior descending coronary artery. There are few reported cases with simultaneous occurrence of multiple bridges of different coronary arteries in the same patient. In this article we report a 60-year-old male with hypertrophic cardiomyopathy having multiple myocardial bridges left anterior descending and right coronary arteries. No ischemia was detected on myocardial perfusion single photon emission computed tomography and the patient was medically followed up.

  9. Comparison of several innovative bridge cable surface modifications

    DEFF Research Database (Denmark)

    Kleissl, Kenneth; Georgakis, Christos T.

    Over the last two decades, several bridge cable manufacturers have introduced surface modifications on the high-density polyethylene (HDPE) sheathing that is installed for the protection of inner cable strands or wires. The modifications are based on research undertaken predominantly in Europe and......-span bridges can now produce more than 50% of the overall horizontal load on the bridge (Gimsing and Georgakis, 2012). Recently, the authors presented a comprehensive comparative study of the aerodynamic performance of these existing cable surface modifications (Kleissl and Georgakis, 2011, 2012). The...

  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. An effective Handling of Thermal Bridges in the EPBD Context

    DEFF Research Database (Denmark)

    Erhorn, Hans; Erhorn-Kluttig, Heike; Thomsen, Kirsten Engelund; Rose, Jørgen; Aggerholm, Søren

    thermal bridge effects to the energy balance, used software tools and thermal bridge atlases, available good practice guidance and promotion of good building practice to the execution quality and advanced thermal bridge driven technical developments. This report presents the gathered knowledge, draws...... conclusions, shows good country examples and gives recommendations to specific groups of audience such as policy makers and standardisation bodies but also to educational institutions, building professionals, building owners and the building industry on how to improve the quality of building component...

  12. 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.

  13. 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.

  14. 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)

  15. Development of Murray Loop Bridge for High Induced Voltage

    Science.gov (United States)

    Isono, Shigeki; Kawasaki, Katsutoshi; Kobayashi, Shin-Ichi; Ishihara, Hayato; Chiyajo, Kiyonobu

    In the case of the cable fault that ground fault resistance is less than 10MΩ, Murray Loop Bridge is excellent as a fault locator in location accuracy and the convenience. But, when the induction of several hundred V is taken from the single core cable which adjoins it, a fault location with the high voltage Murray Loop Bridge becomes difficult. Therefore, we developed Murray Loop Bridge, which could be applied even when the induced voltage of several hundred V occurs in the measurement cable. The evaluation of the fault location accuracy was done with the developed prototype by the actual line and the training equipment.

  16. Thermal Bridges in Building Construction - Measurements and Calculations

    DEFF Research Database (Denmark)

    Rose, Jørgen

    The thesis investigates detailed calculation methods for evaluating heat loss through building envelope constructions, or more specific, thermal bridges. First a detailed description of the calculation methods, i.e. both calculation programs and guidelines, for calculating typical thermal bridges...... detailed calculations in more operational and applicable projecting tools, e.g. thermal bridge catalogues or U-value tables....... in building envelope constructions is given. After this a validation of both programs and guidelines is presented. The validation is performed by comparing calculated U-values with Guarded Hot Box measurements. The last part of the thesis discusses the possibilities of utilising the results of...

  17. 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%.

  18. 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

  19. 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

  20. 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.