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Sample records for hybrid seismic isolation

  1. Seismic performance evaluation of an MR elastomer-based smart base isolation system using real-time hybrid simulation

    Science.gov (United States)

    Eem, S. H.; Jung, H. J.; Koo, J. H.

    2013-05-01

    Recently, magneto-rheological (MR) elastomer-based base isolation systems have been actively studied as alternative smart base isolation systems because MR elastomers are capable of adjusting their modulus or stiffness depending on the magnitude of the applied magnetic field. By taking advantage of the MR elastomers’ stiffness-tuning ability, MR elastomer-based smart base isolation systems strive to alleviate limitations of existing smart base isolation systems as well as passive-type base isolators. Until now, research on MR elastomer-based base isolation systems primarily focused on characterization, design, and numerical evaluations of MR elastomer-based isolators, as well as experimental tests with simple structure models. However, their applicability to large civil structures has not been properly studied yet because it is quite challenging to numerically emulate the complex behavior of MR elastomer-based isolators and to conduct experiments with large-size structures. To address these difficulties, this study employs the real-time hybrid simulation technique, which combines physical testing and computational modeling. The primary goal of the current hybrid simulation study is to evaluate seismic performances of an MR elastomer-based smart base isolation system, particularly its adaptability to distinctly different seismic excitations. In the hybrid simulation, a single-story building structure (non-physical, computational model) is coupled with a physical testing setup for a smart base isolation system with associated components (such as laminated MR elastomers and electromagnets) installed on a shaking table. A series of hybrid simulations is carried out under two seismic excitations having different dominant frequencies. The results show that the proposed smart base isolation system outperforms the passive base isolation system in reducing the responses of the structure for the excitations considered in this study.

  2. Seismic isolation for Advanced LIGO

    CERN Document Server

    Abbott, R; Allen, G; Cowley, S; Daw, E; Debra, D; Giaime, J; Hammond, G; Hammond, M; Hardham, C; How, J; Hua, W; Johnson, W; Lantz, B; Mason, K; Mittleman, R; Nichol, J; Richman, S; Rollins, J; Shoemaker, D; Stapfer, G; Stebbins, R

    2002-01-01

    The baseline design concept for a seismic isolation component of the proposed 'Advanced LIGO' detector upgrade has been developed with proof-of-principle experiments and computer models. It consists of a two-stage in-vacuum active isolation platform that is supported by an external hydraulic actuation stage. Construction is underway for prototype testing of a full-scale preliminary design.

  3. Seismic Isolation Working Meeting Gap Analysis Report

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Justin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sabharwall, Piyush [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    The ultimate goal in nuclear facility and nuclear power plant operations is operating safety during normal operations and maintaining core cooling capabilities during off-normal events including external hazards. Understanding the impact external hazards, such as flooding and earthquakes, have on nuclear facilities and NPPs is critical to deciding how to manage these hazards to expectable levels of risk. From a seismic risk perspective the goal is to manage seismic risk. Seismic risk is determined by convolving the seismic hazard with seismic fragilities (capacity of systems, structures, and components (SSCs)). There are large uncertainties associated with evolving nature of the seismic hazard curves. Additionally there are requirements within DOE and potential requirements within NRC to reconsider updated seismic hazard curves every 10 years. Therefore opportunity exists for engineered solutions to manage this seismic uncertainty. One engineered solution is seismic isolation. Current seismic isolation (SI) designs (used in commercial industry) reduce horizontal earthquake loads and protect critical infrastructure from the potentially destructive effects of large earthquakes. The benefit of SI application in the nuclear industry is being recognized and SI systems have been proposed, in the American Society of Civil Engineers (ASCE) 4 standard, to be released in 2014, for Light Water Reactors (LWR) facilities using commercially available technology. However, there is a lack of industry application to the nuclear industry and uncertainty with implementing the procedures outlined in ASCE-4. Opportunity exists to determine barriers associated with implementation of current ASCE-4 standard language.

  4. Seismic isolation of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Whittaker, Andrew S.; Kuma, Manish [Dept. of Civil, Structural and Environmental Engineering, State University of New York, Buffalo (United States)

    2014-10-15

    Seismic isolation is a viable strategy for protecting safety-related nuclear structures from the effects of moderate to severe earthquake shaking. Although seismic isolation has been deployed in nuclear structures in France and South Africa, it has not seen widespread use because of limited new build nuclear construction in the past 30 years and a lack of guidelines, codes and standards for the analysis, design and construction of isolation systems specific to nuclear structures. The funding by the United States Nuclear Regulatory Commission of a research project to the Lawrence Berkeley National Laboratory and MCEER/University at Buffalo facilitated the writing of a soon-to-be-published NUREG on seismic isolation. Funding of MCEER by the National Science Foundation led to research products that provide the technical basis for a new section in ASCE Standard 4 on the seismic isolation of safety-related nuclear facilities. The performance expectations identified in the NUREG and ASCE 4 for seismic isolation systems, and superstructures and substructures are described in the paper. Robust numerical models capable of capturing isolator behaviors under extreme loadings, which have been verified and validated following ASME protocols, and implemented in the open source code OpenSees, are introduced.

  5. A hybrid base isolation system

    Energy Technology Data Exchange (ETDEWEB)

    Hart, G.C. [Univ. of California, Los Angeles, CA (United States); Lobo, R.F.; Srinivasan, M. [Hart Consultant Group, Santa Monica, CA (United States); Asher, J.W. [kpff Engineers, Santa Monica, CA (United States)

    1995-12-01

    This paper proposes a new analysis procedure for hybrid base isolation buildings when considering the displacement response of a base isolated building to wind loads. The system is considered hybrid because of the presence of viscous dampers in the building above the isolator level. The proposed analysis approach incorporates a detailed site specific wind study combined with a dynamic nonlinear analysis of the building response.

  6. Large scale phononic metamaterials for seismic isolation

    Energy Technology Data Exchange (ETDEWEB)

    Aravantinos-Zafiris, N. [Department of Sound and Musical Instruments Technology, Ionian Islands Technological Educational Institute, Stylianou Typaldou ave., Lixouri 28200 (Greece); Sigalas, M. M. [Department of Materials Science, University of Patras, Patras 26504 (Greece)

    2015-08-14

    In this work, we numerically examine structures that could be characterized as large scale phononic metamaterials. These novel structures could have band gaps in the frequency spectrum of seismic waves when their dimensions are chosen appropriately, thus raising the belief that they could be serious candidates for seismic isolation structures. Different and easy to fabricate structures were examined made from construction materials such as concrete and steel. The well-known finite difference time domain method is used in our calculations in order to calculate the band structures of the proposed metamaterials.

  7. Seismic base isolation by nonlinear mode localization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y. [University of Illinois, Department of Civil and Environmental Engineering, Urbana, IL (United States); Washington University, Department of Civil and Environmental Engineering, St. Louis, MO (United States); McFarland, D.M. [University of Illinois, Department of Aerospace Engineering, Urbana, IL (United States); Vakakis, A.F. [National Technical University of Athens, Division of Mechanics (Greece); Bergman, L.A. [University of Illinois, Department of Mechanical and Industrial Engineering, Urbana, IL (United States)

    2005-03-01

    In this paper, the performance of a nonlinear base-isolation system, comprised of a nonlinearly sprung subfoundation tuned in a 1:1 internal resonance to a flexible mode of the linear primary structure to be isolated, is examined. The application of nonlinear localization to seismic isolation distinguishes this study from other base-isolation studies in the literature. Under the condition of third-order smooth stiffness nonlinearity, it is shown that a localized nonlinear normal mode (NNM) is induced in the system, which confines energy to the subfoundation and away from the primary or main structure. This is followed by a numerical analysis wherein the smooth nonlinearity is replaced by clearance nonlinearity, and the system is excited by ground motions representing near-field seismic events. The performance of the nonlinear system is compared with that of the corresponding linear system through simulation, and the sensitivity of the isolation system to several design parameters is analyzed. These simulations confirm the existence of the localized NNM, and show that the introduction of simple clearance nonlinearity significantly reduces the seismic energy transmitted to the main structure, resulting in significant attenuation in the response. (orig.)

  8. Seismic Analysis of a Viscoelastic Damping Isolator

    Directory of Open Access Journals (Sweden)

    Bo-Wun Huang

    2015-01-01

    Full Text Available Seismic prevention issues are discussed much more seriously around the world after Fukushima earthquake, Japan, April 2011, especially for those countries which are near the earthquake zone. Approximately 1.8×1012 kilograms of explosive energy will be released from a magnitude 9 earthquake. It destroys most of the unprotected infrastructure within several tens of miles in diameter from the epicenter. People can feel the earthquake even if living hundreds of miles away. This study is a seismic simulation analysis for an innovated and improved design of viscoelastic damping isolator, which can be more effectively applied to earthquake prevention and damage reduction of high-rise buildings, roads, bridges, power generation facilities, and so forth, from earthquake disaster. Solidworks graphic software is used to draw the 3D geometric model of the viscoelastic isolator. The dynamic behavior of the viscoelastic isolator through shock impact of specific earthquake loading, recorded by a seismometer, is obtained via ANSYS finite element package. The amplitude of the isolator is quickly reduced by the viscoelastic material in the device and is shown in a time response diagram. The result of this analysis can be a crucial reference when improving the design of a seismic isolator.

  9. Mechanical characterization of seismic base isolation elastomers

    Energy Technology Data Exchange (ETDEWEB)

    Kulak, R.F.; Hughes, T.H.

    1991-01-01

    From the various devices proposed for seismic isolators, the laminated elastomer bearing is emerging as the preferred device for large buildings/structures, such as nuclear reactor plants. The laminated bearing is constructed from alternating thin layers of elastomer and metallic plates (shims). The elastomer is usually a carbon filled natural rubber that exhibits damping when subjected to shear. Recently, some blends of natural and synthetic rubbers have appeared. Before candidate elastomers can be used in seismic isolation bearings, their response to design-basis loads and beyond- design-basis loads must be determined. This entails the development of constitutive models and and then the determination of associated material parameters through specimen testing. This paper describes the methods used to obtain data for characterizing the mechanical response of elastomers used for seismic isolation. The data provides a data base for use in determining material parameters associated with nonlinear constitutive models. In addition, the paper presents a definition for a damping ratio that does not exhibit the usual reduction at higher strain cycles. 2 refs., 6 figs., 1 tab.

  10. Retrofitting Heritage Buildings by Strengthening or Using Seismic Isolation

    Science.gov (United States)

    Danieli, Moshe; Bloch, Jacob; Ribakov, Yuri

    2008-07-01

    Many heritage buildings in the Mediterranean area include stone domes as a structural and architectural element. Present stage of these buildings often requires strengthening or retrofitting in order to increase their seismic resistance. Strengthening is possible by casting above existing dome a thin reinforced concrete shell with a support ring. It yields reduction of stresses and strains in the dome. This paper deals with examples of actual restoration and strengthening of three structures in Georgia, two of them damaged by an earthquake in 1991, (a temple in Nikortzminda and a synagogue in Oni, built in 11th and 19r century, respectively) and a mosque in Akhaltzikhe, built in 18th century. Retrofitting of these structures was aimed at preservation of initial geometry and appearance by creating composite (stone—reinforced concrete, or stone—shotcrete) structures, which were partially or fully hidden. Further improving of seismic response may be achieved by using hybrid seismic isolation decreasing the seismic forces and adding damping. A brief description of the design procedure for such cases is presented.

  11. Seismic base isolation technologies for Korea advanced liquid metal reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, B.; Lee, J.-H.; Koo, G.-H.; Lee, H.-Y.; Kim, J.-B. [Korea Atomic Energy Research Inst., Taejon (Korea, Republic of)

    2000-06-01

    This paper describes the status and prospects of the seismic base isolation technologies for Korea Advanced Liquid Metal Reactor (KALIMER). The research and development program on the seismic base isolation for KALIMER began in 1993 by KAERI under the national long-term R and D program. The objective of this program is to enhance the seismic safety, to accomplish the economic design, and to standardize the plant design through the establishment of technologies on seismic base isolation for liquid metal reactors. In this paper, tests and analyses performed in the program are presented. (orig.)

  12. Evaluation methodology for seismic base isolation of nuclear equipments

    Energy Technology Data Exchange (ETDEWEB)

    Ebisawa, K. (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)); Uga, T. (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan))

    1993-08-01

    An evaluation methodology for seismic base isolated nuclear equipments is proposed. The evaluation can be classified into two steps. In the first step, the seismic functional failure probability during the lifetime of equipment without base isolation devices is quantified in order to decide the applicability of the base isolated structure. The second step is comparative and calculates the ratio of the seismic failure frequency of the equipment without base isolation devices to that with them in order to evaluate the effectiveness of the base isolated structure. The sample evaluation considers the case of high voltage type emergency transformer with ceramic tubes. (orig.)

  13. Seismic base isolation in practice: The California experience

    Energy Technology Data Exchange (ETDEWEB)

    Naeim, F. [John A. Martin and Associates, Inc., Los Angeles, CA (United States); Lew, M. [Law/Crandall, Inc., Los Angeles, CA (United States)

    1995-12-01

    Seismic base isolation systems of various forms and features have been implemented in design of many new buildings and in rehabilitation of several existing structures. Currently, at least in California, the seismic isolation option is seriously considered at the onset of design of any hospital or health care facility project. While the design and implementation of seismic isolation systems seem to have been successful, there exist a multitude of problems which need to be addressed during each of the design, manufacturing, and construction processes to ensure a satisfactory end-result. The authors have been involved as structural and geotechnical engineers, as well as peer reviewers and plan checkers for many of the landmark California seismic isolated structures. This paper will provide a summary of state-of-the-practice and its problems for seismic isolated building structures.

  14. Multi-axial active isolation for seismic protection of buildings

    Science.gov (United States)

    Chang, Chia-Ming

    Structural control technology has been widely accepted as an effective means for the protection of structures against seismic hazards. Passive base isolation is one of the common structural control techniques used to enhance the performance of structures subjected to severe earthquake excitations. Isolation bearings employed at the base of a structure naturally increase its flexibility, but concurrently result in large base displacements. The combination of base isolation with active control, i.e., active base isolation, creates the possibility of achieving a balanced level of control performance, reducing both floor accelerations as well as base displacements. Many theoretical papers have been written by researchers regarding active base isolation, and a few experiments have been performed to verify these theories; however, challenges in appropriately scaling the structural system and modeling the complex nature of control-structure interaction have limited the applicability of these results. Moreover, most experiments only focus on the implementation of active base isolation under unidirectional excitations. Earthquakes are intrinsically multi-dimensional, resulting in out-of-plane responses, including torsional responses. Therefore, an active isolation system for buildings using multi-axial active control devices against multi-directional excitations must be considered. The focus of this dissertation is the development and experimental verification of active isolation strategies for multi-story buildings subjected to bi-directional earthquake loadings. First, a model building is designed to match the characteristics of a representative full-scale structure. The selected isolation bearings feature low friction and high vertical stiffness, providing stable behavior. In the context of the multi-dimensional response control, three, custom-manufactured actuators are employed to mitigate both in-plane and out-of-plane responses. To obtain a high-fidelity model of the

  15. Seismic Base Isolation Analysis for PASCAR Liquid Metal Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kuk Hee; Yoo, Bong; Kim, Yun Jae [Korea Univ., Seoul (Korea, Republic of)

    2008-10-15

    This paper presents a study for developing a seismic isolation system for the PASCAR (Proliferation resistant, Accident-tolerant, Self-supported, Capsular and Assured Reactor) liquid metal reactor design. PASCAR use lead-bismuth eutectic (LBE) as coolant. Because the density (10,000kg/m{sup 3}) of LBE coolant is very heavier than sodium coolant and water, this presents a challenge to designers of the seismic isolation systems that will be used with these heavy liquid metal reactors. Finite element analysis is adapted to determine the characteristics of the isolator device. Results are presented from a study on the use of three-dimensional seismic isolation devices to the full-scale reactor. The seismic analysis responses of the two-dimensional and the three-dimensional isolation systems for the PASCAR are compared with that of the conventional fixed base system.

  16. Reduction of structural response to near fault earthquakes by seismic isolation columns and variable friction dampers

    Science.gov (United States)

    Ribakov, Y.

    2010-03-01

    This paper focuses on the investigation of a hybrid seismic isolation system with passive variable friction dampers for protection of structures against near fault earthquakes. The seismic isolation can be implemented by replacing the conventional columns fixed to the foundations by seismic isolating ones. These columns allow horizontal displacement between the superstructure and the foundations and decouple the building from the damaging earthquake motion. As a result, the forces in the structural elements decrease and damage that may be caused to the building by the earthquake significantly decreases. However, this positive effect is achieved on account of displacements occurring in the isolating columns. These displacements become very large when the structure is subjected to a strong earthquake. In this case, impact may occur between the parts of the isolating column yielding their damage or collapse. In order to limit the displacements in the isolating columns, it is proposed to add variable friction dampers. A method for selecting the dampers’ properties is proposed. It is carried out using an artificial ground motion record and optimal active control algorithm. Numerical simulation of a sevenstory structure shows that the proposed method allows efficient reduction in structural response and limits the displacements at the seismic isolating columns.

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

    Directory of Open Access Journals (Sweden)

    E. Tubaldi

    2015-01-01

    Full Text Available 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. The first technique employs the complex mode superposition method and provides an exact benchmark solution to the problem at hand. The two other simplified techniques are based on an approximation of the displacement field and are useful for preliminary assessment and design purposes. A realistic bridge is considered as case study and its seismic response under a set of ground motion records is analyzed. First, the complex mode superposition method is applied to study the characteristic features of the dynamic and seismic response of the system. A parametric analysis is carried out to evaluate the influence of support stiffness and damping on the seismic performance. Then, a comparison is made between the exact solution and the approximate solutions in order to evaluate the accuracy and suitability of the simplified analysis techniques for evaluating the seismic response of partially isolated bridges.

  18. Recent developments in seismically isolated buildings in Japan

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Building Standard Law of Japan and related Enforcement Order and Notifications have been substantially revised since the year 2000 to introduce a performance-based regulatory and deregulation system for building control systems.Up to then, time-history analyses were mandatory for isolated buildings and had to be specially approved by the Minster of the Ministry of Construction (MOC). Simplified design procedures based on the equivalent linear method for seismically isolated buildings have been issued as "Notification 2009 - Structural calculation procedure for buildings with seismic isolation" from MOC, and are now integrated into the Ministry of Land, Infrastructure, and Transportation (MLIT). Along with Notification 2009, "Notification 1446 of year 2000 Standard for specifications and test methods for seismic isolation devices" was also issued. Buildings with heights equal to or less than 60m and that are designed according to these Notifications, including base isolated buildings, only need approval from local building officials, and no longer require the special approval of the Minister of MLIT. This paper summarizes: 1 ) some statistics related to buildings with seismic isolation completed up to the end of 2001;2) simplified design procedures required by Notification 2009 of year 2000; and 3) performance of seismic isolation devicesrequired by Notification 1446 of year 2000.

  19. Mitigation of earthquake hazards using seismic base isolation systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C.Y.

    1994-06-01

    This paper deals with mitigation of earthquake hazards using seismic base-isolation systems. A numerical algorithm is described for system response analysis of isolated structures with laminated elastomer bearings. The focus of this paper is on the adaptation of a nonlinear constitutive equation for the isolation bearing, and the treatment of foundation embedment for the soil-structure-interaction analysis. Sample problems are presented to illustrate the mitigating effect of using base-isolation systems.

  20. ELASTOMERIC SEISMIC-PROTECTION ISOLATORS FOR BUILDINGS AND BRIDGES

    Institute of Scientific and Technical Information of China (English)

    Toshio Nishi; Nobuo Murota

    2013-01-01

    A giant earthquake of magnitude 9.0 occurred in Pacific Ocean off of Tohoku District Japan on March 11,2011.The highest seismic intensity of 7 in JMA scale was recorded in Miyagi.In the Tohoku district,around 230 buildings are seismically isolated (hereafter,SI) mainly by elastomeric isolators (seismic rubber bearings).According to the official survey reports by several organizations (for example[1]),the records of those buildings have verified the effectiveness of the seismic isolation.The response acceleration of the SI buildings was reduced by 30% to 50% of the input ground acceleration.Additionally,the difference of the conditions inside the room between SI and the fixed-base buildings was obvious as well as the damage in main structures of the buildings.The displacements of the isolators by the earthquake were around 200 mm according to the records of the instruments.As a result,the performance of SI buildings and the elastomeric isolators in the Tohoku District-Off the Pacific Ocean Earthquake 2011 were excellent,and the efficiency of the seismic isolation was verified by the records of many buildings in wide area.

  1. Numerical test on polystyrene tunnel seismic-isolation material

    Directory of Open Access Journals (Sweden)

    He Jianping

    2016-09-01

    Full Text Available Stress-strain mechanical properties of polystyrene foam plastic material were tested under different loading conditions. An empirical constitutive model for describing metal materials was proposed for the polystyrene plastic foam. The static and dynamic tests results show that the ductility and watertightness of the polystyrene plastic foam are significantly improved. At the same time, in order to check its seismic-isolation property, the high-performance foam concrete as filling materials of Galongla tunnel in Tibet was simulated by FEM. The simulated results show that the polystyrene plastic foam can remarkably decrease the stress and the plastic zone in final lining, so it can effectively reduce the seismic damage of the tunnel. Considering the seismic-isolation property and low price of polystyrene plastic foam, it is a good reference for the anti-seismic design of tunnels in high intensity zones.

  2. SEISMIC ISOLATION AND ENERGY DISSIPATION: THEORETICAL BASIS AND APPLICATIONS

    OpenAIRE

    Marsico, Maria Rosaria

    2008-01-01

    The protection of the building from seismic events is a fundamental phase in the structures design should be introduced to avoid the loss of lives especially when it occurs in developing countries. This natural calamity produces social and economic consequences because a lot of people are killed by the collapse of brittle heavy unreinforced masonry or poorly constructed concrete buildings. The engineers can use in their professional practice seismic isolation or energy dissipation devices to ...

  3. Probabilistic seismic response and reliability assessment of isolated bridges

    Institute of Scientific and Technical Information of China (English)

    Giuseppe Carlo Marano

    2005-01-01

    Bridge seismic isolation strategy is based on the reduction of shear forces transmitted from the superstructure to the piers by two means: shifting natural period and earthquake input energy reduction by dissipation concentrated in protection devices. In this paper, a stochastic analysis of a simple isolated bridge model for different bridge and device parameters is conducted to assess the efficiency of this seismic protection strategy. To achieve this aim, a simple nonlinear softening constitutive law is adopted to model a wide range of isolation devices, characterized by only three essential mechanical parameters. As a consequence of the random nature of seismic motion, a probabilistic analysis is carried out and the time modulated Kanai-Tajimi stochastic process is adopted to represent the seismic action. The response covariance in the state space is obtained by solving the Lyapunov equation for a stochastic linearized system. After a sensitivity analysis, the failure probability referred to extreme displacement and the mean value of dissipated energy are assessed by using the introduced stochastic indices of seismic bridge protection efficiency. A parametric analysis for protective devices with different mechanical parameters is developed for a proper selection of parameters of isolation devices under different situations.

  4. Application of Shape Memory Alloys in Seismic Isolation: A Review

    Directory of Open Access Journals (Sweden)

    Shaghayegh Alvandi

    2014-12-01

    Full Text Available In the last two decades, there has been an increasing interest in structural engineering control methods. Shape memory alloys and seismic isolation systems are examples of passive control systems that use of any one alone, effectively improve the seismic performance of the structure. Characteristics such as large strain range without any residual deformation, high damping capacity, excellent re-centering, high resistance to fatigue and corrosion and durability have made shape memory alloy an effective damping device or part of base isolators. A unique characteristic of shape memory alloys is in recovering residual deformations even after strong ground excitations. Seismic isolation is a device to lessen earthquake damage prospects. In the latest research studies, shape memory alloy is utilized in combination with seismic isolation system and their results indicate the effectiveness of the application of them to control the response of the structures. This paper reviews the findings of research studies on base isolation system implemented in the building and/or bridge structures by including the unique behavior of shape memory alloys. This study includes the primary information about the characteristic of the isolation system as well as the shape memory material. The efficiency and feasibility of the two mechanisms are also presented by few cases in point.

  5. Development and Mechanical Performance of a New Kind of Bridge Seismic Isolator for Low Seismic Regions

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    H. Zhang

    2013-01-01

    Full Text Available The concept of fibre-reinforced plate elastomeric isolator (FRPEI is introduced firstly in this paper. Three FRPEI specimens have been constructed to evaluate the mechanical performance of the isolators by performing vertical and horizontal tests. The research focuses on the compression stiffness, the shear stiffness, the hysteretic characteristic and the vertical bearing capacity of the isolators. The experimental results show that the mechanical performance of FRPEIs can meet the requirements of bridge rubber bearings and the energy dissipation capacity is better than that of general laminated rubber bearings. Therefore, it is feasible to use FRPEIs in seismic isolation of short span bridges in low seismic regions. Theoretical and finite element methods have also been employed and the deformation assumptions applied in the theoretical method are also verified by FEM. By comparing the differences of the results of different methods, the effectivenesses of the theoretical and finite element methods are evaluated and some considerations on isolator design are proposed.

  6. Potential role of seismic base isolation in the DOE

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, S.C.

    1993-08-01

    For nearly two decades, the United States Department of Energy (DOE) has substantially increased its efforts to reduce the effects of earthquakes on its facilities. Traditional means within the DOE for designing or retrofitting structures to mitigate earthquake effects include strengthening and anchoring. A nontraditional and an increasingly popular concept for mitigating the effects of earthquakes on structures is seismic base isolation. Because base isolation is emerging as a promising technology for mitigating seismic effects, its potential role in the DOE must be evaluated. In order to use the technology within the DOE, criteria and guidance need to be developed since base isolation may provide a viable design option for mitigating the effects of earthquakes on DOE facilities. This paper discusses the fundamentals of seismic base isolation, applications of the technology, and how the technology might be applied within the DOE. The future involvement of the DOE in base isolation will be part of its efforts to be a leader in meeting the Federal requirements for seismic safety.

  7. Decreasing Seismic Effects of Structures Using Base Isolation Systems

    OpenAIRE

    Baciu, Cristina-Elena; Atanasiu, Gabriela M.

    2014-01-01

    This paper presents many different energy dissipating dispositives that had been proposed to assist in mitigation the harmful effects of earthquakes on structures. The general details of the isolation systems were described, and a particular situation of an isolation system formed by elastomeric supports in the case study. Romania is a country with a strong seismicity, mainly in Vrancea zone, and the Earthquakes affect a large part of the state. To prevent any further structural damages, ...

  8. Hybrid Isolation Forest - Application to Intrusion Detection

    OpenAIRE

    Marteau, Pierre-François; Soheily-Khah, Saeid; Béchet, Nicolas

    2017-01-01

    From the identification of a drawback in the Isolation Forest (IF) algorithm that limits its use in the scope of anomaly detection, we propose two extensions that allow to firstly overcome the previously mention limitation and secondly to provide it with some supervised learning capability. The resulting Hybrid Isolation Forest (HIF) that we propose is first evaluated on a synthetic dataset to analyze the effect of the new meta-parameters that are introduced and verify that the addressed limi...

  9. Vibration Isolation for Parallel Hydraulic Hybrid Vehicles

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    The M. Nguyen

    2008-01-01

    Full Text Available In recent decades, several types of hybrid vehicles have been developed in order to improve the fuel economy and to reduce the pollution. Hybrid electric vehicles (HEV have shown a significant improvement in fuel efficiency for small and medium-sized passenger vehicles and SUVs. HEV has several limitations when applied to heavy vehicles; one is that larger vehicles demand more power, which requires significantly larger battery capacities. As an alternative solution, hydraulic hybrid technology has been found effective for heavy duty vehicle because of its high power density. The mechanical batteries used in hydraulic hybrid vehicles (HHV can be charged and discharged remarkably faster than chemical batteries. This feature is essential for heavy vehicle hybridization. One of the main problems that should be solved for the successful commercialization of HHV is the excessive noise and vibration involving with the hydraulic systems. This study focuses on using magnetorheological (MR technology to reduce the noise and vibration transmissibility from the hydraulic system to the vehicle body. In order to study the noise and vibration of HHV, a hydraulic hybrid subsystem in parallel design is analyzed. This research shows that the MR elements play an important role in reducing the transmitted noise and vibration to the vehicle body. Additionally, locations and orientations of the isolation system also affect the efficiency of the noise and vibration mitigation. In simulations, a skyhook control algorithm is used to achieve the highest possible effectiveness of the MR isolation system.

  10. Seismic behavior of variable frequency pendulum isolator

    Institute of Scientific and Technical Information of China (English)

    V. R. Panchal; R. S. Jangid

    2008-01-01

    Earthquake performance of a flexible one-story building isolated with a variable frequency pendulum isolator(VFPI) under near-fault and far-field ground motions is investigated. The frictional forces mobilized at the interface of theVFPI are assumed to be velocity dependent. The interaction between frictional forces of the VFPI in two horizontal directionsis duly considered and coupled differential equations of motion of the isolated system in the incremental form are solvediteratively. The response of the system with bi-directional interaction is compared with those without interaction. In addition,the effects of velocity dependence on the response of the isolated system are also investigated. Moreover, a parametricstudy is carried out to critically examine the influence of important parameters on bi-directional interaction effects of thefrictional forces of the VFPI. These parameters are: the superstructure time period, frequency variation factor (FVF) andfriction coefficient of the VFPI. From the above investigations, it is observed that the dependence of the friction coefficienton relative velocity of the system does not have a noticeable effect on the peak response of the system isolated with VFPI, andthat the bi-directional interaction of frictional forces of the VFPI is important and if neglected, isolator displacements will beunderestimated and the superstructure acceleration and base shear will be overestimated.

  11. Earthquake Response and Isolation Layer Parameter Effect of Seismic Isolation Systems of Transformers With Bushings

    Institute of Scientific and Technical Information of China (English)

    CAO Meigen; ZHOU Fulin; TAN Ping; ZHANG Guangping; GAO Zhengguo

    2012-01-01

    Seismic damage data and experiences on power transformers at home and abroad indicate that the destruction type of high-power transformers is various and the vulnerability is very high. Furthermore, the post-disaster reconstruction of transformers, which needs a long recovery cycle and a high cost, will be very difficult. Studies have shown that the acceleration response of the transformer and bushings will be quickly reduced and seismic reliability of transformer will be improved because there is one seismic isolation layer between the bottom of transformer tank and the base which form the seismic isolation system of the transformer and bushings (SISTB). But isolation layer design and parameters selection of SISTB have larger difference with general structures.

  12. A seismic design of nuclear reactor building structures applying seismic isolation system in a seismicity region-a feasibility case study in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Tetsuo [The University of Tokyo, Tokyo (Japan); Yamamoto, Tomofumi; Sato, Kunihiko [Mitsubishi Heavy Industries, Ltd., Kobe (Japan); Jimbo, Masakazu [Toshiba Corporation, Yokohama (Japan); Imaoka, Tetsuo [Hitachi-GE Nuclear Energy, Ltd., Hitachi (Japan); Umeki, Yoshito [Chubu Electric Power Co. Inc., Nagoya (Japan)

    2014-10-15

    A feasibility study on the seismic design of nuclear reactor buildings with application of a seismic isolation system is introduced. After the Hyogo-ken Nanbu earthquake in Japan of 1995, seismic isolation technologies have been widely employed for commercial buildings. Having become a mature technology, seismic isolation systems can be applied to NPP facilities in areas of high seismicity. Two reactor buildings are discussed, representing the PWR and BWR buildings in Japan, and the application of seismic isolation systems is discussed. The isolation system employing rubber bearings with a lead plug positioned (LRB) is examined. Through a series of seismic response analyses using the so-named standard design earthquake motions covering the design basis earthquake motions obtained for NPP sites in Japan, the responses of the seismic isolated reactor buildings are evaluated. It is revealed that for the building structures examined herein: (1) the responses of both isolated buildings and isolating LRBs fulfill the specified design criteria; (2) the responses obtained for the isolating LRBs first reach the ultimate condition when intensity of motion is 2.0 to 2.5 times as large as that of the design-basis; and (3) the responses of isolated reactor building fall below the range of the prescribed criteria.

  13. A Natural Seismic Isolating System: The Buried Mangrove Effects

    CERN Document Server

    Gueguen, Philippe; Foray, Pierre; Rousseau, Christophe; Maury, Julie; 10.1785/0120100129

    2011-01-01

    The Belleplaine test site, located in the island of Guadeloupe (French Lesser Antilles) includes a three-accelerometer vertical array, designed for liquefac- tion studies. The seismic response of the soil column at the test site is computed using three methods: the spectral ratio method using the vertical array data, a numerical method using the geotechnical properties of the soil column, and an operative fre- quency domain decomposition (FDD) modal analysis method. The Belleplaine test site is characterized by a mangrove layer overlaid by a stiff sandy deposit. This con- figuration is widely found at the border coast of the Caribbean region, which is exposed to high seismic hazard. We show that the buried mangrove layer plays the role of an isolation system equivalent to those usually employed in earthquake engineering aimed at reducing the seismic shear forces by reducing the internal stress within the structure. In our case, the flexibility of the mangrove layer reduces the distortion and the stress in the...

  14. Study on the seismic performance of a double spherical seismic isolation bearing

    Institute of Scientific and Technical Information of China (English)

    Peng Tianbo; Li Jianzhong; Xu Yan; Fan Lichu

    2008-01-01

    In this paper,the configuration and working mechanism of the recently developed double spherical seismic isolation (DSSI) bearing are introduced in detail.Then,vertical displacement of the DSSI bearing due to sliding on a spherical surface is analyzed.The results from seismic performance testing of the bearing are given,and a numerical analysis of a four span continuous girder bridge is performed.The numerical analysis compares the influence of three different bearing arrangement schemes on the structural seismic response,and the results show that the DSSI bearing is effective in increasing the vertical load bearing capacity,reducing the vertical displacement,and controlling the energy dissipation capacity within a certain range.

  15. Final report of the cooperative study on seismic isolation design. The second stage

    Energy Technology Data Exchange (ETDEWEB)

    Uryu, Mitsuru; Terada, Syuji; Shioya, Tsutomu (and others)

    1999-05-01

    The applicability of the seismic isolation design onto the nuclear fuel facilities, which must clear severe criteria of integrity, has been examined. Following the first stage of the cooperative study, conducted from 1988 to 1991, the second stage included critical vibration testing, seismic observation of seismic isolation building and founded buildings of non-isolation, with the objectives of clarifying the policies on critical design of seismic isolation building. Integrity of the seismic isolation piping system was tested by means of static deformation test, with variable inner water pressure and relative deformation. (Yamamoto, A.)

  16. Seismic isolation device having charging function by a transducer

    Science.gov (United States)

    Yamaguchi, Takashi; Miura, Nanako; Takahashi, Masaki

    2016-04-01

    In late years, many base isolated structures are planned as the seismic design, because they suppress vibration response significantly against large earthquake. To achieve greater safety, semi-active or active vibration control system is installed in the structures as earthquake countermeasures. Semi-active and active vibration control systems are more effective than passive vibration control system to large earthquake in terms of vibration reduction. However semi-active and active vibration control system cannot operate as required when external power supply is cut off. To solve the problem of energy consumption, we propose a self-powered active seismic isolation floor which achieve active control system using regenerated vibration energy. This device doesn't require external energy to produce control force. The purpose of this study is to propose the seismic isolation device having charging function and to optimize the control system and passive elements such as spring coefficients and damping coefficients using genetic algorithm. As a result, optimized model shows better performance in terms of vibration reduction and electric power regeneration than the previous model. At the end of this paper, the experimental specimen of the proposed isolation device is shown.

  17. Technology transfer package on seismic base isolation - Volume II

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-14

    This Technology Transfer Package provides some detailed information for the U.S. Department of Energy (DOE) and its contractors about seismic base isolation. Intended users of this three-volume package are DOE Design and Safety Engineers as well as DOE Facility Managers who are responsible for reducing the effects of natural phenomena hazards (NPH), specifically earthquakes, on their facilities. The package was developed as part of DOE's efforts to study and implement techniques for protecting lives and property from the effects of natural phenomena and to support the International Decade for Natural Disaster Reduction. Volume II contains the proceedings for the Short Course on Seismic Base Isolation held in Berkeley, California, August 10-14, 1992.

  18. Technology transfer package on seismic base isolation - Volume I

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-14

    This Technology Transfer Package provides some detailed information for the U.S. Department of Energy (DOE) and its contractors about seismic base isolation. Intended users of this three-volume package are DOE Design and Safety Engineers as well as DOE Facility Managers who are responsible for reducing the effects of natural phenomena hazards (NPH), specifically earthquakes, on their facilities. The package was developed as part of DOE's efforts to study and implement techniques for protecting lives and property from the effects of natural phenomena and to support the International Decade for Natural Disaster Reduction. Volume I contains the proceedings of the Workshop on Seismic Base Isolation for Department of Energy Facilities held in Marina Del Rey, California, May 13-15, 1992.

  19. Seismic base isolation: Elastomer characterization, bearing modeling and system response

    Energy Technology Data Exchange (ETDEWEB)

    Kulak, R.F.; Wang, C.Y.; Hughes, T.H.

    1991-01-01

    This paper discusses several major aspects of seismic base isolation systems that employ laminated elastomer bearings. Elastomer constitutive models currently being used to represent the nonlinear elastic and hysteretic behavior are discussed. Some aspects of mechanical characterization testing of elastomers is presented along with representative tests results. The development of a finite element based mesh generator for laminated elastomer bearings is presented. Recent advances in the simulation of base isolated structures to earthquake motions are presented along with a sample problem. 13 refs., 19 figs., 1 tab.

  20. Seismic isolation effect of lined circular tunnels with damping treatments

    Institute of Scientific and Technical Information of China (English)

    Seyyed M. Hasheminejad; Amir K. Miri

    2008-01-01

    The Havriliak-Negami model for dynamic viscoelastic material behavior and Biot's theory of poroelasticity are employed to develop an exact solution for three-dimensional scattering effect of harmonic plane P-SV waves from a circular cavity lined with a multilayered fluid-filled shell of infinite length containing viscoelastic damping materials and embedded within a fluid-saturated permeable surrounding soil medium. The analytical results are illustrated with numerical examples where the effects of liner/coating structural arrangement, viscoelastic material properties, liner-soil interface bonding condition, seismic excitation frequency, and angle of incidence on the induced dynamic stress concentrations are evaluated and discnssed to obtain representative values of the parameters that characterize the system. It is demonstrated that incorporating viscoelastic damping materials with a low shear modulus in the constrained layer configuration is an efficient means of enhancing the overall seismic isolation performance, especially for near-normally incident seismic shear waves where the amplitudes of induced dynamic stresses may be reduced by up to one-third of those without isolation in a relatively wide frequency range. Some additional cases are considered and good agreements with solutions available in the literature are obtained.

  1. Development of Seismic Isolation Systems Using Periodic Materials

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Yiqun [Univ. of Houston, Houston, TX (United States); Mo, Yi-Lung [Univ. of Houston, Houston, TX (United States); Menq, Farn-Yuh [Univ. of Texas, Austin, TX (United States); Stokoe, II, Kenneth H. [Univ. of Texas, Austin, TX (United States); Perkins, Judy [Prairie View A & M University, Prairie View, TX (United States); Tang, Yu [Argonne National Lab. (ANL), Argonne, IL (United States)

    2014-12-10

    Advanced fast nuclear power plants and small modular fast reactors are composed of thin-walled structures such as pipes; as a result, they do not have sufficient inherent strength to resist seismic loads. Seismic isolation, therefore, is an effective solution for mitigating earthquake hazards for these types of structures. Base isolation, on which numerous studies have been conducted, is a well-defined structure protection system against earthquakes. In conventional isolators, such as high-damping rubber bearings, lead-rubber bearings, and friction pendulum bearings, large relative displacements occur between upper structures and foundations. Only isolation in a horizontal direction is provided; these features are not desirable for the piping systems. The concept of periodic materials, based on the theory of solid-state physics, can be applied to earthquake engineering. The periodic material is a material that possesses distinct characteristics that prevent waves with certain frequencies from being transmitted through it; therefore, this material can be used in structural foundations to block unwanted seismic waves with certain frequencies. The frequency band of periodic material that can filter out waves is called the band gap, and the structural foundation made of periodic material is referred to as the periodic foundation. The design of a nuclear power plant, therefore, can be unified around the desirable feature of a periodic foundation, while the continuous maintenance of the structure is not needed. In this research project, three different types of periodic foundations were studied: one-dimensional, two-dimensional, and three-dimensional. The basic theories of periodic foundations are introduced first to find the band gaps; then the finite element methods are used, to perform parametric analysis, and obtain attenuation zones; finally, experimental programs are conducted, and the test data are analyzed to verify the theory. This procedure shows that the

  2. Influence of various parameters on effectiveness of seismic base isolation of nuclear equipment

    Energy Technology Data Exchange (ETDEWEB)

    Ebisawa, K. [Japan Atomic Research Inst., Ibaraki-ken (Japan); Kameoka, H. [CRC Research Inst., Chiba-chi (Japan); Takenouchi, I.; Kajiki, S. [Oiles Corp. (Japan)

    1995-12-31

    Authors developed a methodology and EBISA code for evaluating the applicability and the effectiveness of seismic base isolation of nuclear equipment. In order to investigate the influence of various parameters on the effectiveness of seismic base isolation, a sensitivity analysis was carried out for an emergency transformer with the base isolation devices. It was proved that seismic base isolation of equipment is very effective. This effectiveness can be influenced by the differences of the base isolation devices and the direction of the input seismic wave. (author). 7 refs., 3 figs., 3 tabs.

  3. Seismic fragility analysis of seismically isolated nuclear power plants piping system

    Energy Technology Data Exchange (ETDEWEB)

    Salimi Firoozabad, Ehsan, E-mail: e.salimi@pusan.ac.kr [Department of Civil and Environmental Engineering, Pusan National University, 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Jeon, Bub-Gyu, E-mail: bkjeon79@pusan.ac.kr [KOCED Seismic Simulation Test Center, Pusan National University, Yangsan Campus Mulgeum, Yangsan, Kyungsangnam (Korea, Republic of); Choi, Hyoung-Suk, E-mail: engineer@pusan.ac.kr [KOCED Seismic Simulation Test Center, Pusan National University, Yangsan Campus Mulgeum, Yangsan, Kyungsangnam (Korea, Republic of); Kim, Nam-Sik, E-mail: nskim@pusan.ac.kr [Department of Civil and Environmental Engineering, Pusan National University, 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of)

    2015-04-01

    Highlights: • The critical points of a seismically isolated NPP piping system are identified. • The simulation results are validated through a monotonic and cyclic test of the critical points. • The conditional mean spectrum method is used to scale the selected records. • The fragility curves of the NPP piping system are estimated. • Computation of the fragility parameters is addressed. - Abstract: Nuclear power plants are high risk facilities due to the possibility of sudden seismic events, because any possible failure could initiate catastrophic radioactive contamination. The seismic fragility analysis of NPPs and related equipments (such as piping systems) is a proven method to determine their performance against any possible earthquake. In this study the Brookhaven National laboratory benchmark model of a piping system was considered for the fragility analysis. A tensile test was conducted to define the material properties. An initial seismic analysis of the piping system is performed to indicate the critical sections of the piping system. Numerical analysis was validated through a monotonic and cyclic loading experiment of two identified critical points of the piping system. The tests were conducted at the Korea Construction Engineering Development (KOCED) Seismic Simulation Test Center, Pusan National University, Korea. Fragility curves were expressed for critical points of the system as a function of the spectral acceleration of the records and the maximum relative displacement. The standard deviation of the response and capacity were calculated using mathematical formulas, assuming that those follow a log-normal distribution. We determined that the fragility curve of a pipe elbow must be derived for both the opening and closing mode, regarding the difference between the capacities of the elbow on those modes. The high confidence of low probability of failure for the considered fragility functions in a straight section in any direction is

  4. ADVANCED SEISMIC BASE ISOLATION METHODS FOR MODULAR REACTORS

    Energy Technology Data Exchange (ETDEWEB)

    E. Blanford; E. Keldrauk; M. Laufer; M. Mieler; J. Wei; B. Stojadinovic; P.F. Peterson

    2010-09-20

    Advanced technologies for structural design and construction have the potential for major impact not only on nuclear power plant construction time and cost, but also on the design process and on the safety, security and reliability of next generation of nuclear power plants. In future Generation IV (Gen IV) reactors, structural and seismic design should be much more closely integrated with the design of nuclear and industrial safety systems, physical security systems, and international safeguards systems. Overall reliability will be increased, through the use of replaceable and modular equipment, and through design to facilitate on-line monitoring, in-service inspection, maintenance, replacement, and decommissioning. Economics will also receive high design priority, through integrated engineering efforts to optimize building arrangements to minimize building heights and footprints. Finally, the licensing approach will be transformed by becoming increasingly performance based and technology neutral, using best-estimate simulation methods with uncertainty and margin quantification. In this context, two structural engineering technologies, seismic base isolation and modular steel-plate/concrete composite structural walls, are investigated. These technologies have major potential to (1) enable standardized reactor designs to be deployed across a wider range of sites, (2) reduce the impact of uncertainties related to site-specific seismic conditions, and (3) alleviate reactor equipment qualification requirements. For Gen IV reactors the potential for deliberate crashes of large aircraft must also be considered in design. This report concludes that base-isolated structures should be decoupled from the reactor external event exclusion system. As an example, a scoping analysis is performed for a rectangular, decoupled external event shell designed as a grillage. This report also reviews modular construction technology, particularly steel-plate/concrete construction using

  5. Technology transfer package on seismic base isolation - Volume III

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-14

    This Technology Transfer Package provides some detailed information for the U.S. Department of Energy (DOE) and its contractors about seismic base isolation. Intended users of this three-volume package are DOE Design and Safety Engineers as well as DOE Facility Managers who are responsible for reducing the effects of natural phenomena hazards (NPH), specifically earthquakes, on their facilities. The package was developed as part of DOE's efforts to study and implement techniques for protecting lives and property from the effects of natural phenomena and to support the International Decade for Natural Disaster Reduction. Volume III contains supporting materials not included in Volumes I and II.

  6. Seismic isolation of nuclear power plants using elastomeric bearings

    Science.gov (United States)

    Kumar, Manish

    Seismic isolation using low damping rubber (LDR) and lead-rubber (LR) bearings is a viable strategy for mitigating the effects of extreme earthquake shaking on safety-related nuclear structures. Although seismic isolation has been deployed in nuclear structures in France and South Africa, it has not seen widespread use because of limited new build nuclear construction in the past 30 years and a lack of guidelines, codes and standards for the analysis, design and construction of isolation systems specific to nuclear structures. The nuclear accident at Fukushima Daiichi in March 2011 has led the nuclear community to consider seismic isolation for new large light water and small modular reactors to withstand the effects of extreme earthquakes. The mechanical properties of LDR and LR bearings are not expected to change substantially in design basis shaking. However, under shaking more intense than design basis, the properties of the lead cores in lead-rubber bearings may degrade due to heating associated with energy dissipation, some bearings in an isolation system may experience net tension, and the compression and tension stiffness may be affected by the horizontal displacement of the isolation system. The effects of intra-earthquake changes in mechanical properties on the response of base-isolated nuclear power plants (NPPs) were investigated using an advanced numerical model of a lead-rubber bearing that has been verified and validated, and implemented in OpenSees and ABAQUS. A series of experiments were conducted at University at Buffalo to characterize the behavior of elastomeric bearings in tension. The test data was used to validate a phenomenological model of an elastomeric bearing in tension. The value of three times the shear modulus of rubber in elastomeric bearing was found to be a reasonable estimate of the cavitation stress of a bearing. The sequence of loading did not change the behavior of an elastomeric bearing under cyclic tension, and there was no

  7. Application of seismic isolation technology to computer system in nuclear power stations

    Energy Technology Data Exchange (ETDEWEB)

    Gunyasu, Kenzou; Takamatsu, Naotaka; Fujimoto, Shigeru; Fukui, Hidehiro (Toshiba Corp., Kawasaki, Kanagawa (Japan))

    1994-08-01

    In the current aseismatic design, the rigid structures that withstand earthquakes by own strength have been adopted. However recently, seismically isolated structures were devised, and begin to be applied to buildings and others. It is characterized by that the basic structures as the object of seismic isolation are not changed, and by using special seismic isolators, the structures are made flexible to avoid the resonance with the eminent period of earthquakes and reduce the earthquake force acting on the structures. As the concrete example of seismic isolation, in Japan, seismically isolated floors have been introduced for the computer centers of banks. Also in nuclear power stations, the application of seismic isolation to computer systems has been considered. The function, constitution, structure and the method of increasing the aseismatic capability of computer system are explained. The function required for seismic isolation floors, the seismic isolation structure of rolling type composed of coil springs, dampers and ball bearings, its principle of action, and the vibration test on the seismic isolation floor are reported. (K.I.).

  8. Active seat isolation for hybrid electric vehicles

    Science.gov (United States)

    Leo, Donald J.; Malowicki, Mark; Buckley, Stephen J.; Naganathan, Ganapathy

    1999-07-01

    A feasibility study in the use of induced strain actuators for active seal isolation is described. The focus of the work is the isolation of lightweight automotive seats for hybrid-electric vehicles. The feasibility study is based on a numerical analysis of a three-degree-of-freedom vibration model of the seat. Mass and inertia properties are based on measurements from a powered seat that is found in current model year automobiles. Tradeoffs between vertical acceleration of the seat, actuator stroke requirements, and isolation frequency are determined through numerical analysis of the vibration model. Root mean square accelerations and actuator strokes are computed using power spectral densities that model broadband excitation and road excitation that is filtered by the vehicle suspension. Numerical results using the road excitation indicate that factors of two to three reduction in vertical acceleration are achieved when the active isolation frequency is reduced to approximately 1 Hz with damping factors on the order of 10 to 30 percent critical. More significant reductions are achieved in the case of broadband floor excitation. Root mean square actuator strokes for both case are int he range of 0.4 to 50 mm. Root mean square accelerations in the vertical direction are consistent with the levels found in standard comfort curves.

  9. Design response spectra-compliant real and synthetic GMS for seismic analysis of seismically isolated nuclear reactor containment building

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Ahmer [ENVICO Consultants Co. Ltd., Seoul (Korea, Republic of); Abu-Hayah, Nadin; Kim, Doo Kie [Civil and Environmental Engineering, Kunsan National University, Gunsan (Korea, Republic of); Cho, Sung Gook [Innose Tech Co., Ltd., Incheon (Korea, Republic of)

    2017-06-15

    Due to the severe impacts of recent earthquakes, the use of seismic isolation is paramount for the safety of nuclear structures. The diversity observed in seismic events demands ongoing research to analyze the devastating attributes involved, and hence to enhance the sustainability of base-isolated nuclear power plants. This study reports the seismic performance of a seismically-isolated nuclear reactor containment building (NRCB) under strong short-period ground motions (SPGMs) and long-period ground motions (LPGMs). The United States Nuclear Regulatory Commission-based design response spectrum for the seismic design of nuclear power plants is stipulated as the reference spectrum for ground motion selection. Within the period range(s) of interest, the spectral matching of selected records with the target spectrum is ensured using the spectral-compatibility approach. NRC-compliant SPGMs and LPGMs from the mega-thrust Tohoku earthquake are used to obtain the structural response of the base-isolated NRCB. To account for the lack of earthquakes in low-to-moderate seismicity zones and the gap in the artificial synthesis of long-period records, wavelet-decomposition based autoregressive moving average modeling for artificial generation of real ground motions is performed. Based on analysis results from real and simulated SPGMs versus LPGMs, the performance of NRCBs is discussed with suggestions for future research and seismic provisions.

  10. Spring tube braces for seismic isolation of buildings

    Science.gov (United States)

    Karayel, V.; Yuksel, Ercan; Gokce, T.; Sahin, F.

    2017-01-01

    A new low-cost seismic isolation system based on spring tube bracings has been proposed and studied at the Structural and Earthquake Engineering Laboratory of Istanbul Technical University. Multiple compression-type springs are positioned in a special cylindrical tube to obtain a symmetrical response in tension and compression-type axial loading. An isolation floor, which consists of pin-ended steel columns and spring tube bracings, is constructed at the foundation level or any intermediate level of the building. An experimental campaign with three stages was completed to evaluate the capability of the system. First, the behavior of the spring tubes subjected to axial displacement reversals with varying frequencies was determined. In the second phase, the isolation floor was assessed in the quasi-static tests. Finally, a ¼ scaled 3D steel frame was tested on the shake table using actual acceleration records. The transmitted acceleration to the floor levels is greatly diminished because of the isolation story, which effects longer period and higher damping. There are no stability and self-centering problems in the isolation floor.

  11. Studies on the Needs of Seismic Base Isolation Concept and its Standardization

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Min-Seok; Kim, Jong-Hae [Korea Electric Association, Seoul (Korea, Republic of)

    2015-05-15

    In the late 1970s, seismic resistance design was introduced as a new design concept through the construction of nuclear power plants. Before this, lateral forces other than wind loads, such as seismic forces, were not taken into consideration in the structural design process. However, in response to the building of increasingly large and heavy structures such as nuclear power plants, a consensus began to form in society regarding the importance of seismic resistance design to avoid a largescale calamity. Since then, Korea has reinforced the relevant regulations, and there has been some progress. At the same time, the seismic base isolation concept was introduced to encourage active research activities related to building safety issues. It has lately been applied for the purpose of reducing construction costs. In 1980s, seismic base isolation design was applied for 'Cruas' plant in France and 'Koeberg' plant in South Africa. Those two are the few cases in which the seismic base isolation design was applied; for the rest, seismic resistance design was applied in most nuclear power plants that are in operation and in construction in the world. Rather than welcoming innovative technology on a trial basis, nuclear power plant design makes use only of proven technologies, which explains the application of seismic resistance design. As seismic base isolation design has become more accepted for use in the building of domestic general bridges, which has, thereby, confirmed its safety, it has been accepted for nuclear power plant design and has even been actively applied. So far, most structures of nuclear facility have been constructed with seismic resistance design and engineering methods. However, seismic force prediction is not perfect in reality; nor is it financially beneficial to apply the system for gradually increasing seismic resistance design loads. Therefore, it is necessary to apply a seismic base isolation system as a way to help secure the

  12. Effect of the foundation stiffness on the response of a seismically isolated tank under SSE conditions

    NARCIS (Netherlands)

    Esposito, G.; Courage, W.

    2003-01-01

    This paper presents the results of a feasibility study of a seismic isolated 120.000 m3 LNG tank. A simple model was used to evaluate the seismic response of the isolated tank under Safe Shutdown Earthquake conditions. The frequency dependent dynamic stiffness of the foundation was modele

  13. Multi-dimensional Seismic Response Analysis of Base-Isolated Frame Structure with 3D Isolator

    Institute of Scientific and Technical Information of China (English)

    Xiong Shishu; Huang Liting; Chen Jinfeng; Su Jingsu

    2005-01-01

    The three-dimensional lead-rubber dish-spring bearing (3DB) is proposed in this paper. The 3DB is composed of lead rubber bearing (LRB) and dish-spring bearing (DSB) with damper in series. The 3DB put forward in this paper is effective in the resolution of difficulties in strong vertical capacity and vertical damping of three-dimensional isolation bearings. It effectively suppresses rocking motions as well. The analytical model and motion equations of multi-dimensional seismic responses of 3D base-isolated frame structures are established. Taking a five-storey frame structure as an example, an extensive simulation analysis is carried out. The results show that the 3D base-isolated structure with the proposed 3DB is effective in 3D isolation; it can reduce seismic responses by 50 % compared to a non-isolated structure. Therefore, the 3D isolation problem in building can be solved easily and effectively with the 3DB proposed in this paper.

  14. Mechanical behavior of a suite of elastomers used for seismic base isolation

    Energy Technology Data Exchange (ETDEWEB)

    Kulak, R.F.; Hughes, T.H.

    1995-07-01

    Several practical systems have been developed to protect structures and their contents from the potential devastating consequences of earthquakes. The use of seismic isolation has recently proven to be an effective means to mitigate earthquake damage. With seismic isolation, the structures are decoupled from the strong horizontal ground accelerations. The use of high damping elastomer, steel lamiriated seismic isolation bearings has been proven to be an effective method for seismic base isolation. This paper describes recent research conducted at Argonne National Laboratory to find the mechanical response characteristics of a suite of elastomers compounded for use in elastomeric seismic isolation bearings. The response characteristics were obtained by testing small coupons of each elastomer in a high precision dynamic testing machine. Specifically, the paper reports on tests performed to find the variations in stiffness and energy dissipation with strain level, loading rate, and cycle number. The paper also reports on the effects that strain level has on stiffness recovery.

  15. SiSeRHMap v1.0: a simulator for mapped seismic response using a hybrid model

    Science.gov (United States)

    Grelle, Gerardo; Bonito, Laura; Lampasi, Alessandro; Revellino, Paola; Guerriero, Luigi; Sappa, Giuseppe; Guadagno, Francesco Maria

    2016-04-01

    The SiSeRHMap (simulator for mapped seismic response using a hybrid model) is a computerized methodology capable of elaborating prediction maps of seismic response in terms of acceleration spectra. It was realized on the basis of a hybrid model which combines different approaches and models in a new and non-conventional way. These approaches and models are organized in a code architecture composed of five interdependent modules. A GIS (geographic information system) cubic model (GCM), which is a layered computational structure based on the concept of lithodynamic units and zones, aims at reproducing a parameterized layered subsoil model. A meta-modelling process confers a hybrid nature to the methodology. In this process, the one-dimensional (1-D) linear equivalent analysis produces acceleration response spectra for a specified number of site profiles using one or more input motions. The shear wave velocity-thickness profiles, defined as trainers, are randomly selected in each zone. Subsequently, a numerical adaptive simulation model (Emul-spectra) is optimized on the above trainer acceleration response spectra by means of a dedicated evolutionary algorithm (EA) and the Levenberg-Marquardt algorithm (LMA) as the final optimizer. In the final step, the GCM maps executor module produces a serial map set of a stratigraphic seismic response at different periods, grid solving the calibrated Emul-spectra model. In addition, the spectra topographic amplification is also computed by means of a 3-D validated numerical prediction model. This model is built to match the results of the numerical simulations related to isolate reliefs using GIS morphometric data. In this way, different sets of seismic response maps are developed on which maps of design acceleration response spectra are also defined by means of an enveloping technique.

  16. Overview of seismic base isolation systems, applications, and performance during earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Trummer, D.J.; Sommer, S.C.

    1993-08-01

    Seismic base isolation is a technique for mitigating the effects of earthquakes on structures. A structure is decoupled from the potentially damaging forces of an earthquake by placing a flexible isolation system between the structure and the ground. A data base has been created for the US Department of Energy which contains information about systems used to achieve seismic isolation, their applications in structures, and how they have performed during earthquakes. This paper will present and overview of the database.

  17. Dynamic responses of base isolated NPPs under seismic excitations and aircraft crashes

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Sang Hoon; Kim, Hyun Uk; Joo, Kwang Ho [KHNP, Daejeon (Korea, Republic of)

    2012-10-15

    Seismic isolation (SI) is a type of seismic design that is based on the concept of reducing the seismic demand rather than increasing the resistance capacity of the structure and related systems. Applying this technology leads to improved performance of structures that will remain essentially elastic during a design basis earthquake. In the application of the system to a nuclear power plant (NPP) structure to gain seismic resistance advantages, other safety issues should also be considered. One of those issues is the safety of an NPP against an aircraft crash (ACC). In this study, responses of a seismically isolated structure, such as acceleration and displacement, were obtained from a time domain non linear analysis to check the performance of SI system under seismic excitation. In addition, the dynamic responses of NPP structures with or without SI against an ACC were compared and other considerations are discussed.

  18. Behavioural isolation may facilitate homoploid hybrid speciation in cichlid fish

    NARCIS (Netherlands)

    Selz, O. M.; Thommen, R.; Maan, M. E.; Seehausen, O.

    Hybrid speciation is constrained by the homogenizing effects of gene flow from the parental species. In the absence of post-mating isolation due to structural changes in the genome, or temporal or spatial premating isolation, another form of reproductive isolation would be needed for homoploid

  19. Behavioural isolation may facilitate homoploid hybrid speciation in cichlid fish

    NARCIS (Netherlands)

    Selz, O. M.; Thommen, R.; Maan, M. E.; Seehausen, O.

    2014-01-01

    Hybrid speciation is constrained by the homogenizing effects of gene flow from the parental species. In the absence of post-mating isolation due to structural changes in the genome, or temporal or spatial premating isolation, another form of reproductive isolation would be needed for homoploid hybri

  20. Performance-Based Seismic Design of Bitlis River Viaduct Based on Damage Control Using Seismic Isolation and Energy Dissipation Devices

    Science.gov (United States)

    Dicleli, Murat; Salem Milani, Ali

    2017-06-01

    This paper presents a sample application of seismic isolation techniques in performance-based design of a major viaduct. The Bitlis River viaduct is located in a seismically active region. The targeted performance goal required no damage at 475-year return period earthquake and repairable damage at 2475-year return period earthquake. The bridge is designed with a seismic isolation system composed of spherical bearings and MRSD (Multidirectional Re-centering steel Damper) hysteretic dampers. The MRSD is a recently-developed hysteretic damper with a controllable post-elastic stiffness. To keep the dampers from being activated during the thermal displacements, the attachment of the dampers to the deck are made through elongated holes oriented in the longitudinal direction of the bridge. The gaps are sized based on the amount of expected maximum thermal displacement in each pier. The gap length is thus different for different piers. This means that the number of the dampers to be engaged during an earthquake will depend on the intensity of the displacements. The distinct feature in this design is how it achieves double purpose: (i)preventing the dampers from engagement during service life as a result of thermal displacements and (ii) sequential engagement of the dampers depending on the level of seismically-induced displacements. The paper presents the basic design features of this seismically isolated bridge designed based on performance-based principles, a brief description of the newly-developed damper and a summary of analyses results.

  1. Characterization and performance evaluation of a vertical seismic isolator using link and crank mechanism

    Science.gov (United States)

    Tsujiuchi, N.; Ito, A.; Sekiya, Y.; Nan, C.; Yasuda, M.

    2016-09-01

    In recent years, various seismic isolators have been developed to prevent earthquake damage to valuable art and other rare objects. Many seismic isolators only defend against horizontal motions, which are the usual cause of falling objects. However, the development of a seismic isolator designed for vertical vibration is necessary since such great vertical vibration earthquakes as the 2004 Niigata Prefecture Chuetsu Earthquake have occurred, and their increased height characteristics are undesirable. In this study, we developed a vertical seismic isolator that can be installed at a lower height and can support loads using a horizontal spring without requiring a vertical spring. It has a mechanism that combines links and cranks. The dynamic model was proposed and the frequency characteristics were simulated when the sine waves were the input. Shaking tests were also performed. The experimental value of the natural frequency was 0.57 Hz, and the theoretical values of the frequency characteristics were close to the experimental values. In addition, we verified this vertical seismic isolator's performance through shaking tests and simulation for typical seismic waves in Japan. We verified the seismic isolation's performance from the experimental result because the average reduction rate of the acceleration was 0.21.

  2. SiSeRHMap v1.0: a simulator for mapped seismic response using a hybrid model

    Directory of Open Access Journals (Sweden)

    G. Grelle

    2015-06-01

    Full Text Available SiSeRHMap is a computerized methodology capable of drawing up prediction maps of seismic response. It was realized on the basis of a hybrid model which combines different approaches and models in a new and non-conventional way. These approaches and models are organized in a code-architecture composed of five interdependent modules. A GIS (Geographic Information System Cubic Model (GCM, which is a layered computational structure based on the concept of lithodynamic units and zones, aims at reproducing a parameterized layered subsoil model. A metamodeling process confers a hybrid nature to the methodology. In this process, the one-dimensional linear equivalent analysis produces acceleration response spectra of shear wave velocity-thickness profiles, defined as trainers, which are randomly selected in each zone. Subsequently, a numerical adaptive simulation model (Spectra is optimized on the above trainer acceleration response spectra by means of a dedicated Evolutionary Algorithm (EA and the Levenberg–Marquardt Algorithm (LMA as the final optimizer. In the final step, the GCM Maps Executor module produces a serial map-set of a stratigraphic seismic response at different periods, grid-solving the calibrated Spectra model. In addition, the spectra topographic amplification is also computed by means of a numerical prediction model. This latter is built to match the results of the numerical simulations related to isolate reliefs using GIS topographic attributes. In this way, different sets of seismic response maps are developed, on which, also maps of seismic design response spectra are defined by means of an enveloping technique.

  3. Optimum Performance-Based Seismic Design Using a Hybrid Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    S. Talatahari

    2014-01-01

    Full Text Available A hybrid optimization method is presented to optimum seismic design of steel frames considering four performance levels. These performance levels are considered to determine the optimum design of structures to reduce the structural cost. A pushover analysis of steel building frameworks subject to equivalent-static earthquake loading is utilized. The algorithm is based on the concepts of the charged system search in which each agent is affected by local and global best positions stored in the charged memory considering the governing laws of electrical physics. Comparison of the results of the hybrid algorithm with those of other metaheuristic algorithms shows the efficiency of the hybrid algorithm.

  4. Base Isolation for Seismic Retrofitting of a Multiple Building Structure: Design, Construction, and Assessment

    Directory of Open Access Journals (Sweden)

    Massimiliano Ferraioli

    2017-01-01

    Full Text Available The paper deals with the seismic retrofit of a multiple building structure belonging to the Hospital Centre of Avellino (Italy. At first, the paper presents the preliminary investigations, the in situ measurements and laboratory tests, and the seismic assessment of the existing fixed-base structures. Having studied different strategies, base isolation proved to be the more appropriate, also for the possibility offered by the geometry of the building to easily create an isolation interface at the ground level. The paper presents the design project, the construction process, and the details of the isolation intervention. Some specific issues of base isolation for seismic retrofitting of multiple building structures were lightened. Finally, the seismic assessment of the base-isolated building was carried out. The seismic response was evaluated through nonlinear time-history analysis, using the well-known Bouc-Wen model as the constitutive law of the isolation bearings. For reliable dynamic analyses, a suite of natural accelerograms compatible with acceleration spectra of Italian Code was first selected and then applied along both horizontal directions. The results were finally used to address some of the critical issues of the seismic response of the base-isolated multiple building structure: accidental torsional effects and potential poundings during strong earthquakes.

  5. Seismic fragility of a highway bridge in Quebec retrofitted with natural rubber isolators

    Directory of Open Access Journals (Sweden)

    G. H. Siqueira

    Full Text Available This paper presents fragility curves for the evaluation of a highway bridge retrofitted with seismic isolator devices. The object of this study is the Chemin des Dalles bridge over Highway 55 located in Trois-Rivières in Quebec, Canada. A series of synthetic ground motions time histories compatible with eastern Canada are used to capture the uncertainties related to the hazard. The seismic isolator model represents natural rubber bearing placed under the longitudinal girders over the bents and the abutments of the bridge. NRB isolators are placed in these locations to uncouple the movement of the superstructure and the infrastructure, increasing the flexibility of the system and decreasing the forces transmitted to the infrastructure. Finally, a set of fragility curves for the as-built and retrofitted models are compared to evaluate the effectiveness of seismic isolation to decrease the seismic vulnerability of this bridge.

  6. Structural design of active seismic isolation floor with a charging function

    Science.gov (United States)

    Nakakoji, Hayato; Miura, Nanako

    2016-04-01

    This study shows an optimum structure of a seismic isolation floor against horizontal ground motions. Although a seismic isolation floor is effective with vibration reduction, the response of the floor becomes larger when excited by long-period ground motions. It is shown that caster equipment move and suffer damage in a seismic isolation structure by an experiment. Moreover, the permissible displacement of the floor is limited. Therefore, the focus is on an active seismic isolation. About active control, the system cannot operate without power supply. To solve these problems an energy regeneration is considered in our previous study. These studies only analyze simple model and did not choose the suitable structure for active control and energy regeneration. This research propose a new structure which has regenerated energy exceeds the energy required for the active control by numerical simulation.

  7. Effects on the Floor Response Spectra by the Nonlinear Behavior of a Seismic Base Isolation System

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyungkui; Kim, Jung Han; Choi, Inkil [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    An evaluation of safety being carried out for various risk factors of prevents for nuclear power plant accident. In general, an evaluation of the structural integrity was performed about seismic risk. In recent years, an assessment of integrity of internal equipment being carried out for earthquake loads owing to the possibility of severe accidents caused by the destruction of internal equipment or a blackout. Floor response spectra of the structure should be sought for evaluating of the integrity of internal equipment. The floor response spectra depends on the characteristics of seismic base isolation system such as the natural frequency, damping ratio, and height of the floor of the structure. An evaluation of the structural integrity using the equivalent stiffness of the seismic base isolation system was satisfactory. In this study, the effect of the non-linearity of isolated system in the floor response spectrum of the structure is analyzed. In this study, the floor response spectrum of the seismic base isolation system by the non-linear effect of the rubber isolator was analyzed. As a result, the influence of the non-linear isolated system was increased in hi-frequency domain. In addition, each floor exhibited a more different of responses compared with the equivalent linear model of the isolated structure. The non-linearity of the isolation system of the structure was considered, because of a more reliable assessment of integrity of equipment at each floor of seismic base the isolation system.

  8. Hybrid Recentering Energy Dissipative Device for Seismic Protection

    Directory of Open Access Journals (Sweden)

    Wenke Tang

    2014-01-01

    Full Text Available A hybrid recentering energy dissipative device that has both recentering and energy dissipation capabilities is proposed and studied in this paper. The proposed hybrid device, referred to as the hybrid shape memory alloy (SMA recentering viscous fluid (RCVF energy dissipation device, connects the apex of a chevron brace to an adjoining beam using two sets of SMA wires arranged in series on either side of the brace and a viscous fluid damper arranged in parallel with the SMA wires. The viscous damper is used because being a velocity-dependent device it does not exert any force that counteracts the recentering force from the SMA wires after the vibration of the frame ceases. In the numerical study, the Wilde’s SMA constitutive model is used to model the SMA wires, and the Maxwell model is used to simulate the viscous fluid damper. To demonstrate the viability and effectiveness of the proposed hybrid device, comparative studies are performed on several single-story shear frames and a series of four-story steel frames. The results show that the frames equipped with the hybrid device have noticeably smaller peak top story displacements and residual story drifts when subjected to ground motions at three different intensity levels.

  9. Seismic analysis and evaluation of the base isolation system in AP1000 NI under SSE loading

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jianyun; Zhao, Chunfeng, E-mail: zhaowindy@126.com; Xu, Qiang; Yuan, Chenyang

    2014-10-15

    Graphical abstract: - Highlights: • The feasibility of base isolation technique in NI is evaluated. • A comparison of structural response highlighted the effectiveness of isolation system. • DAR was proposed to validate the effectiveness of base isolation under SSE. • Connection of pipes, seismic gap and fail safety system are also considered. - Abstract: Safety and integrity of NPP must be ensured during the plant life in any design conditions, particularly, in the event of a severe earthquake. Base isolation as a popular and powerful technology can drastically reduce the seismic response of the structure and prevent the structure from damage. The objective of this paper is to numerically investigate the dynamic response of the AP1000 Nuclear Island (NI) building with and without isolators under a typical safe shutdown earthquake (SSE). By the help of a sophisticated detailed three-dimensional finite element model of the Nuclear Island, the different design solutions are compared in terms of acceleration and relative displacement. The decreasing amplitude ratio (DAR) obtained in the calculations highlights the effectiveness of the isolation system in mitigating the seismic response of the nuclear island of AP1000. Acceleration floor response spectra (carried out from both isolated and non-isolated seismic analysis) are herein also presented and compared in order to validate the isolation technology effectiveness. The obtained numerical results highlight the drastic reduction of considered floor accelerations as the base isolation major effect. The connection of pipelines and design criteria of isolators presently recommended for the stability of isolated building are also validated and verified to highlight the feasibility and safety of the base isolation system. In addition, seismic gap, expansion joint and horizontal fail safe system are also recommended to apply in the isolated structure.

  10. Analysis of Bi-directional Effects on the Response of a Seismic Base Isolation System

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyung-Kui; Kim, Jung-Han; Kim, Min Kyu; Choi, In-Kil [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    The floor response spectrum depends on the height of the floor of the structure. Also FRS depends on the characteristics of the seismic base isolation system such as the natural frequency, damping ratio. In the previous study, the floor response spectrum of the base isolated structure was calculated for each axis without considering bi-directional effect. However, the shear behavior of the seismic base isolation system of two horizontal directions are correlated each other by the bi-directional effects. If the shear behavior of the seismic isolation system changes, it can influence the floor response spectrum and displacement response of isolators. In this study, the analysis of a bi-directional effect on the floor response spectrum was performed. In this study, the response of the seismic base isolation system based on the bi-directional effects was analyzed. By analyzing the time history result, while there is no alteration in the maximum shear force of seismic base isolation system, it is confirmed that the shear force is generally more decreased in a one-directional that in a two-directional in most parts. Due to the overall decreased shear force, the floor response spectrum is more reduced in a two-directional than in a one-directional.

  11. Seismic Responses of Asymmetric Base-Isolated Structures under Near-Fault Ground Motion

    Institute of Scientific and Technical Information of China (English)

    YE Kun; LI Li; FANG Qin-han

    2008-01-01

    An inter-story shear model of asymmetric base-isolated structures incorporating deformation of each isolation bearing was built, and a method to simultaneously simulate bi-directional near-fault and far-field ground motions was proposed. A comparative study on the dynamic responses of asymmetric base-isolated structures under near-fault and far-field ground motions were conducted to investigate the effects of eccentricity in the isolation system and in the superstructures, the ratio of the uncoupled torsional to lateral frequency of the superstructure and the pulse period of near-fault ground motions on the nonlinear seismic response of asymmetric base-isolated structures. Numerical results show that eccentricity in the isolation system makes asymmetric base-isolated structure more sensitive to near-fault ground motions, and the pulse period of near-fault ground motions plays an import role in governing the seismic responses of asymmetric base-isolated structures.

  12. Reproductive isolation and the expansion of an invasive hybrid swarm

    Science.gov (United States)

    Blum, Michael J.; Walters, David M.; Burkhead, Noel M.; Freeman, Byron J.; Porter, Brady A.

    2010-01-01

    Biological invasions involving hybridization proceed according to prezygotic and postzygotic reproductive isolating mechanisms. Yet few comparisons of reproductive isolation have been carried out to understand how different mechanisms prevent or promote invasions involving hybridization. Here we present a study of prezygotic and postzygotic isolation between non-native red shiner (Cyprinella lutrensis) and native blacktail shiner (C. venusta stigmatura) from the Coosa River basin (USA) to better understand the formation and expansion of invasive hybrid swarms. We conducted spawning trials to measure mating preferences and raised broods from crosses to assay hybrid viability through early juvenile development. Females of both species were more responsive to conspecific mates, although blacktail shiner females responded more often to heterospecific mates than did red shiner females. Fecundity of red shiner females was also higher than blacktail shiner females. Heterospecific crosses resulted in lower fertilization and egg hatching rates, but we found no other evidence of inviability. Rather, we found comparatively low larval mortality of F1 hybrids, which is suggestive of heterosis. These findings support prior inferences of assortative mating from genetic descriptions of hybridization, and that the invasion in the Coosa River is likely proceeding due to interspecific competition and intrinsic hybrid viability.

  13. Hybrid zoneless probabilistic seismic hazard analysis: Test and first application to SW Germany

    Science.gov (United States)

    Chan, C.; Gruenthal, G.

    2007-12-01

    Zoneless approaches are one option to assess probabilistic seismic hazard (PSHA). They rely simply on smoothing the epicenter locations of past events according to the fractal distribution of earthquakes in space without defining seismic source zones. However, some shortcomings are connected with these zoneless approaches. Sometimes, one cannot apply one single magnitude completeness, especially when the study area covers different catalogue areas, where different completeness patterns are valid. Furthermore, the characteristic depths of the strongest earthquakes generally differ over larger areas. With respect to these two reasons, a hybrid approach for zoneless PSHA is introduced in this study; i.e. a combination of a zoneless approach with a seismic source model based solely on the large scale geological architecture. This large scale model meets the requirements of introducing different magnitude completeness. But the probability of the earthquake occurrence is based on a pure zoneless approach. Then, instead of a time set of magnitude completeness for the entire studying area, as it is the standard procedure for zoneless approaches, various time sets for different large zones are considered. Another innovation of our approach is to take into account the actual depth of each earthquake rather than assuming a certain weighting set of depths. We apply the hybrid zoneless approach to the SW part of Germany, which represents one of the highest seismicity areas in the country. The use of area specific magnitude completeness and actual depths of all events clearly results in a more realistic PSHA. Furthermore, we compare the results of the hybrid zoneless approach with the results of a recent study using a zone-based methodology. The zone-based approach shows more significant contrasts in the study area; i.e the hybrid zoneless approach provides a rather smoothed pattern. This corresponds to comparisons between zoneless and zone-based approaches by previous studies.

  14. R D activities at Argonne National Laboratory for the application of base seismic isolation in nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Seidensticker, R.W.

    1991-01-01

    Argonne National Laboratory (ANL) has been deeply involved in the development of seismic isolation for use in nuclear facilities for the past decade. Initial focus of these efforts has been on the use of seismic isolation for advanced liquid metal reactors (LMR). Subsequent efforts in seismic isolation at ANL included a lead role in an accelerated development program for possible use of seismic isolation for the DOE's New Production reactors (NPR). Under funding provided by the National Science Foundation (NSF) Argonne is currently working with Shimizu in a joint United States-Japanese program on response of seismically-isolated buildings to actual earthquakes. The results of recent work in the seismic isolation program elements are described in this paper. The current Status of these programs is presented along with an assessment of work still needed to bring the benefits of this emerging technology to full potential in nuclear reactors and other nuclear facilities. 38 refs., 3 figs.

  15. Nonlinear dynamic analysis of multi-base seismically isolated structures with uplift potential I: formulation

    Institute of Scientific and Technical Information of China (English)

    Panos C. Tsopelas; Panayiotis C. Roussis; Michael C. Constantinou

    2009-01-01

    The complexity of modern seismically isolated structures requires the analysis of the structural system and the isolation system in its entirety and the ability to capture potential discontinuous phenomena such as isolator uplift and their effects on the superstructures and the isolation hardware. In this paper, an analytical model is developed and a computational algorithm is formulated to analyze complex seismically isolated superstructures even when undergoing highly-nonlinear phenomena such as uplift. The computational model has the capability of modeling various types of isolation devices with strong nonlinearities, analyzing multiple superstructures (up to five separate superstructures) on multiple bases (up to five bases), and capturing the effects of lateral loads on bearing axial forces, including bearing uplift. The model developed herein has been utilized to form the software platform 3D-BASIS-ME-MB, which provides the practicing engineering community with a versatile tool for analysis and design of complex structures with modem isolation systems.

  16. A hybrid model for mapping simplified seismic response via a GIS-metamodel approach

    Directory of Open Access Journals (Sweden)

    G. Grelle

    2014-02-01

    Full Text Available An hybrid model, consisting of GIS and metamodel (model of model procedures, was introduced with the aim of estimating the 1-D spatial seismic site response. Inputs and outputs are provided and processed by means of an appropriate GIS model, named GIS Cubic Model (GCM. This discretizes the seismic underground half-space in a pseudo-tridimensional way. GCM consists of a layered parametric structure aimed at resolving a predicted metamodel by means of pixel to pixel vertical computing. The metamodel leading to the determination of a bilinear-polynomial function is able to design the classic shape of the spectral acceleration response in relation to the main physical parameters that characterize the spectrum itself. The main physical parameters consist of (i the average shear wave velocity of the shallow layer, (ii the fundamental period and, (iii the period where the spatial spectral response is required. The metamodel is calibrated on theoretical spectral accelerations regarding the local likely Vs-profiles, which are obtained using the Monte Carlo simulation technique on the basis of the GCM information. Therefore, via the GCM structure and the metamodel, the hybrid model provides maps of normalized acceleration response spectra. The hybrid model was applied and tested on the built-up area of the San Giorgio del Sannio village, located in a high-risk seismic zone of Southern Italy.

  17. Issues concerning the application of seismic base isolation in the DOE

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, S.C.; Trummer, D.J.

    1994-02-01

    Since the early 1970`s, the United States Department of Energy (DOE) has been engaged in a program to mitigate the effects of earthquakes on its facilities. Traditional means within the DOE or designing or retrofitting structures to withstand earthquakes include strengthening and anchoring. A nontraditional and in increasingly popular concept for lessening the effects of earthquakes on structures is seismic base isolation. Because base isolation is emerging as a promising technology for mitigating seismic effects, is potential role in the DOE must be evaluated. In order to use the technology within the DOE, there are technical and implementation issues that need to be carefully studied. By addressing these issues, base isolation can become a viable design option for mitigating the effects of earthquakes on DOE facilities. This overview paper discusses the potential applications of seismic base isolation in the DOE and the necessary steps for implementing the technology in the DOE.

  18. Analysis and Design of One Dimensional Periodic Foundations for Seismic Base Isolation of Structures

    Directory of Open Access Journals (Sweden)

    Witarto Witarto

    2016-01-01

    Full Text Available Periodic foundationis a new type of seismic base isolation system. It is inspired by the periodic material crystal lattice in the solid state physics. This kind of material has a unique property, which is termed as frequency band gap that is capable of blocking incoming waves having frequencies falling within the band gap. Consequently, seismic waves having frequencies falling within the frequency band gap are blocked by the periodic foundation. The ability to block the seismic waveshas put this kind of foundation as a prosperous next generation of seismic base isolators. This paper provides analytical study on the one dimensional (1D type periodic foundations to investigate their seismic performance. The general idea of basic theory of one dimensional (1D periodic foundations is first presented.Then, the parametric studies considering infinite and finite boundary conditions are discussed. The effect of superstructure on the frequency band gap is investigated as well. Based on the analytical study, a set of equations is proposed for the design guidelines of 1D periodic foundations for seismic base isolation of structures.

  19. NSR&D Program Fiscal Year (FY) 2015 Call for Proposals Mitigation of Seismic Risk at Nuclear Facilities using Seismic Isolation

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Justin [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-02-01

    Seismic isolation (SI) has the potential to drastically reduce seismic response of structures, systems, or components (SSCs) and therefore the risk associated with large seismic events (large seismic event could be defined as the design basis earthquake (DBE) and/or the beyond design basis earthquake (BDBE) depending on the site location). This would correspond to a potential increase in nuclear safety by minimizing the structural response and thus minimizing the risk of material release during large seismic events that have uncertainty associated with their magnitude and frequency. The national consensus standard America Society of Civil Engineers (ASCE) Standard 4, Seismic Analysis of Safety Related Nuclear Structures recently incorporated language and commentary for seismically isolating a large light water reactor or similar large nuclear structure. Some potential benefits of SI are: 1) substantially decoupling the SSC from the earthquake hazard thus decreasing risk of material release during large earthquakes, 2) cost savings for the facility and/or equipment, and 3) applicability to both nuclear (current and next generation) and high hazard non-nuclear facilities. Issue: To date no one has evaluated how the benefit of seismic risk reduction reduces cost to construct a nuclear facility. Objective: Use seismic probabilistic risk assessment (SPRA) to evaluate the reduction in seismic risk and estimate potential cost savings of seismic isolation of a generic nuclear facility. This project would leverage ongoing Idaho National Laboratory (INL) activities that are developing advanced (SPRA) methods using Nonlinear Soil-Structure Interaction (NLSSI) analysis. Technical Approach: The proposed study is intended to obtain an estimate on the reduction in seismic risk and construction cost that might be achieved by seismically isolating a nuclear facility. The nuclear facility is a representative pressurized water reactor building nuclear power plant (NPP) structure

  20. Improvement of levitation force characteristics in magnetic levitation type seismic isolation device composed of HTS bulk and permanent magnet

    Science.gov (United States)

    Tsuda, M.; Kawasaki, T.; Yagai, T.; Hamajima, T.

    2008-02-01

    Magnetic levitation type seismic isolation device composed of HTS bulks and permanent magnets can theoretically remove horizontal vibration completely. It is, however, not easy to generate the large levitation force by using only the levitation system composed of HTS bulk and permanent magnet (HTS-PM system). We focused on a hybrid levitation system composed of the HTS-PM system and the PM-PM system composed of only permanent magnets and investigated the suitable arranging method of the hybrid system for improving levitation force and obtaining stable levitation. In order to clarify the most suitable permanent magnet arrangement in the PM-PM system for the levitation force improvement, repulsive force between permanent magnets was measured in various kinds of the PM-PM system. The maximum repulsive force per unit area in the PM-PM system was at least three times larger than the levitation force per unit area in the HTS-PM system, so that the levitation force in the hybrid system was larger than that of the HTS-PM system. Stable levitation was also achieved in the hybrid system. This is because repulsive force in the PM-PM system against horizontal displacement was much smaller than restoring force in the HTS-PM system.

  1. Applications of hybrid genetic algorithms in seismic tomography

    Science.gov (United States)

    Soupios, Pantelis; Akca, Irfan; Mpogiatzis, Petros; Basokur, Ahmet T.; Papazachos, Constantinos

    2011-11-01

    Almost all earth sciences inverse problems are nonlinear and involve a large number of unknown parameters, making the application of analytical inversion methods quite restrictive. In practice, most analytical methods are local in nature and rely on a linearized form of the problem equations, adopting an iterative procedure which typically employs partial derivatives in order to optimize the starting (initial) model by minimizing a misfit (penalty) function. Unfortunately, especially for highly non-linear cases, the final model strongly depends on the initial model, hence it is prone to solution-entrapment in local minima of the misfit function, while the derivative calculation is often computationally inefficient and creates instabilities when numerical approximations are used. An alternative is to employ global techniques which do not rely on partial derivatives, are independent of the misfit form and are computationally robust. Such methods employ pseudo-randomly generated models (sampling an appropriately selected section of the model space) which are assessed in terms of their data-fit. A typical example is the class of methods known as genetic algorithms (GA), which achieves the aforementioned approximation through model representation and manipulations, and has attracted the attention of the earth sciences community during the last decade, with several applications already presented for several geophysical problems. In this paper, we examine the efficiency of the combination of the typical regularized least-squares and genetic methods for a typical seismic tomography problem. The proposed approach combines a local (LOM) and a global (GOM) optimization method, in an attempt to overcome the limitations of each individual approach, such as local minima and slow convergence, respectively. The potential of both optimization methods is tested and compared, both independently and jointly, using the several test models and synthetic refraction travel-time date sets

  2. Proceedings of the first international seminar on seismic base isolation for nuclear power facilities

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    The First International Seminar on Seismic Base Isolation of Nuclear Power Facilities was organized by the authors of this paper. It was held in San Francisco, California, USA, on August 21--22, 1989, in conjunction with the tenth International Conference on Structural Mechanics in Reactor Technology (SMiRT-10). The purpose of the seminar was to provide an international forum for discussion on the application of base isolation to nuclear power plants and of its effectiveness in reducing seismic loads and permitting standard plant designs. It also provided an opportunity for technical interchange between base isolation system designers, structural engineers, and nuclear power plant engineers. Seismic isolation is certainly one of the most significant earthquake engineering developments in recent years. This was clearly demonstrated by the very large attendance at this seminar and the various papers presented. Isolation system act as filters that reduce the seismic forces and increase the ability of isolated structures and their contents to withstand the damaging effects of earthquake motions. Each individual paper has been cataloged separately.

  3. Hybrid isolation of micro vibrations induced by reaction wheels

    Science.gov (United States)

    Lee, Dae-Oen; Park, Geeyong; Han, Jae-Hung

    2016-02-01

    As the technology for precision satellite payloads continues to advance, the requirements for the pointing stability of the satellites are becoming extremely high. In many situations, even small amplitude disturbances generated by the onboard components may cause serious degradation in the performance of high precision payloads. In such situations, vibration isolators can be installed to reduce the vibration transmission. In this work, a hybrid vibration isolator comprising passive and active components is proposed to provide an effective solution to the vibration problems caused by the reaction wheel disturbances. Firstly, mathematical modeling and experimental study of a single axis vibration isolator having high damping and high roll-off rate for the high frequency region and active components that enhance isolation performance for narrow frequency bands are presented. This concept is then extended to multi-axis by forming Stewart platform and the performance is experimentally verified. The tests on a flexible testbed show effective vibration isolation by the proposed vibration isolator.

  4. Three dimensional periodic foundations for base seismic isolation

    Science.gov (United States)

    Yan, Y.; Cheng, Z.; Menq, F.; Mo, Y. L.; Tang, Y.; Shi, Z.

    2015-07-01

    Based on the concept of phononic crystals, periodic foundations made of periodic materials are investigated in this paper. The periodic foundations can provide low frequency band gaps, which cover the main frequency ranges of seismic waves. Therefore, the periodic foundations are able to protect the upper structures during earthquake events. In this paper, the basic theory of three dimensional periodic foundations is studied and the finite element method was used to conduct the sensitivity study. A simplified three-dimensional periodic foundation with a superstructure was tested in the field and the feasibility of three dimensional periodic foundations was proved. The test results showed that the response of the upper structure with the three dimensional periodic foundation was reduced under excitation waves with the main frequency falling in the attenuation zones. The finite element analysis results are consistent with the experimental data, indicating that three dimensional periodic foundations are a feasible way of reducing seismic vibrations.

  5. Research on Hybrid Seismic Response Control System for Motion Control of Two Span Bridge

    Science.gov (United States)

    Heo, G.; Kim, C.; Jeon, S.; Seo, S.; Jeon, J.

    2016-09-01

    In this paper, a hybrid seismic response control (HSRC) system was developed to control bridge motion caused by seismic load. It was aimed at optimum vibration control, composed of a rubber bearing of passive type and a MR-damper of semi-active type. The bridge model was built for experiment, a two-span bridge of 8.3 meters in length with the HSRC system put up on it. Then, inflicting El-centro seismic load on it, shaking table tests were carried out to confirm the system's validity. The experiments were conducted under the basic structure state (without an MR-damper applied) first, and then under the state with an MR-damper applied. It was also done under the basic structure state with a reinforced rubber bearing applied, then the passive on/off state of the HSRC system, and finally the semi-active state where the control algorithm was applied to the system. From the experiments, it was observed that collision rather increased when the MR-damper alone was applied, and also that the application of the HSRC system effectively prevented it from occurring. As a result, the HSRC system was proven to be effective in mitigating responses of the two-span bridge under seismic load.

  6. Seismic Risk of the Base Isolation System Protected by the Hard Stop

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Han; Choi, In-Kil; Kim, Min Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The concept of base isolation is to permit the deformation of isolator for absorbing seismic input wave from the ground. In a nuclear power plant design, allowable shear deformation of isolators should be enough to absorb the displacement response by extended design basis (EDB) ground motions. However isolators cannot resist over its displacement capacity. So, the clearance of hard stop (CHS) needs to be set between the response of base isolation system excited by the EDB ground motion and the displacement capacity of isolators. The isolation system must survive with high confidence in any seismic accident because it is a non-redundant system. Therefore, the CHS should be determined carefully based on the failure risk of base isolation system considering the uncertainties of earthquake responses and isolator capacities. In this research, the fragility curve of isolation system and its failure risk were estimated. The procedure to calculate the acceleration based fragility curve of the isolation system was developed. The fragility curve and failure risk for example case was estimated and its result was compared with different isolator capacities.

  7. Enhancement in Seismic Imaging using Diffraction Studies and Hybrid Traveltime Technique for PSDM

    Science.gov (United States)

    Bashir, Y.; Ghosh, D. P.; Moussavi Alashloo, S. Y.; Sum, C. W.

    2016-07-01

    The accurate migration of seismic data is conditional on the parameters which are nominated. The effective velocity used in residual processing for migration is small compared to the original migration velocity. Considering traveltime computation is a significant part of seismic imaging algorithms. Conventional implementation of Kirchhoff migration is essential for precomputing a traveltime table from the categories involving traditional ray-tracing methods and finite difference eikonal solvers. In this paper, we examine the accuracy using, the eikonal solver and paraxial ray tracing traveltime computation in pre-stack Kirchhoff depth migration. This hybrid traveltime technique can be applied to a variety of problems related to faults, fractures, and complex region. To evaluate the relevance of this identical traveltime technique, we applied on a Marmousi data set.

  8. Scavenging vibration energy from seismically isolated bridges using an electromagnetic harvester

    Science.gov (United States)

    Lu, Qiuchen; Loong, Chengning; Chang, Chih-Chen; Dimitrakopoulos, Elias G.

    2014-04-01

    The increasing worldwide efforts in securing renewable energy sources increase incentive for civil engineers to investigate whether the kinetic energy associated with the vibration of larger-scale structures can be harvested. Such a research remains challenging and incomplete despite that hundreds of related articles have been published in the last decade. Base isolation is one of the most popular means of protecting a civil engineering structure against earthquake forces. Seismic isolation hinges on the decoupling of the structure from the shaking ground, hence protecting the structure from stress and damage during an earthquake excitation. The low stiffness isolator inserted between the structure and the ground dominates the response leading to a structural system of longer vibration period. As a consequence of this period shift, the spectral acceleration is reduced, but higher response displacements are produced. To mitigate this side effect, usually isolators are combined with the use of additional energy dissipation. In this study, the feasibility of scavenging the need-to-be dissipated energy from the isolator installed in a seismically isolated bridge using an electromagnetic (EM) energy harvester is investigated. The EM energy harvester consists of an energy harvesting circuit and a capacitor for energy storage. A mathematical model for this proposed EM energy harvester is developed and implemented on an idealized base-isolated single-degree-of-freedom system. The effect of having this EM energy harvester on the performance of this seismic isolated system is analyzed and discussed. The potential of installing such an EM energy harvester on a seismically isolated bridge is also addressed.

  9. Seismic response analysis of coupled building involving MR damper and elastomeric base isolation

    Directory of Open Access Journals (Sweden)

    M.K. Shrimali

    2015-06-01

    The present study investigates the comparative performance of three proposed schemes of coupled building control involving Magnetorheological (MR damper and elastomeric base isolation, named as, Semiactive, Hybrid 1 and Hybrid 2. The results of numerical study showed that Hybrid controls are more effective in controlling the response as compared to Semiactive control. Further, influence of device parameters on control performance has been investigated through a parametric study.

  10. Seismic isolation of Advanced LIGO gravitational waves detectors: Review of strategy, instrumentation, and performance

    CERN Document Server

    Matichard, F; Mittleman, R; Mason, K; Kissel, J; McIver, J; Abbott, B; Abbott, R; Abbott, S; Allwine, E; Barnum, S; Birch, J; Biscans, S; Celerier, C; Clark, D; Coyne, D; DeBra, D; DeRosa, R; Evans, M; Foley, S; Fritschel, P; Giaime, J A; Gray, C; Grabeel, G; Hanson, J; Hardham, C; Hillard, M; Hua, W; Kucharczyk, C; Landry, M; Roux, A Le; Lhuillier, V; Macleod, D; Macinnis, M; Mitchell, R; Reilly, B O; Ottaway, D; Paris, H; Pele, A; Puma, M; Radkins, H; Ramet, C; Robinson, M; Ruet, L; Sarin, P; Shoemaker, D; Stein, A; Thomas, J; Vargas, M; Venkateswara, K; Warner, J; Wen, S

    2015-01-01

    Isolating ground-based interferometric gravitational wave observatories from environmental disturbances is one of the great challenges of the advanced detector era. In order to directly observe gravitational waves, the detector components and test masses must be highly inertially decoupled from the ground motion not only to sense the faint strain of space-time induced by gravitational waves, but also to maintain the resonance of the very sensitive 4 km interferometers. This article presents the seismic isolation instrumentation and strategy developed for Advanced LIGO interferometers. It reviews over a decade of research on active isolation in the context of gravitational wave detection, and presents the performance recently achieved with the Advanced LIGO observatory. Lastly, it discusses prospects for future developments in active seismic isolation and the anticipated benefits to astrophysical gravitational wave searches. Beyond gravitational wave research, the goal of this article is to provide detailed is...

  11. Large-scale seismic isolation through regulated liquefaction: a feasibility study

    Science.gov (United States)

    Mousavi, Seyed Amin; Bastami, Morteza; Zahrai, Seyed Mehdi

    2016-12-01

    Using controlled liquefaction, a seismic isolation technique is introduced by which a large area with dozens of structures can be seismically isolated. The proposed Large Scale Seismic Isolation (LSSI) is in many ways similar to conventional base isolations. The required bearing is provided by a fully undrained pre-saturated liquefiable layer which has substantial vertical stiffness/capacity and minimal lateral stiffness. Moreover, required energy dissipation would be provided through material damping and Biot flow-induced damping within the liquefied layer. LSSI consists of a thick nonliquefiable crust layer and an underlying engineered pre-saturated liquefiable layer bounded by two impermeable thin clay layers. The liquefiable layer should be designed to trigger liquefaction as soon as possible within the early seconds of a design level seismic event. Adopting the energy-based GMP liquefaction theory, optimum gradation of the liquefiable layer is also investigated. It turned out that LSSI would effectively reduce acceleration response spectrum within short to medium periods. Contribution of the proposed LSSI is more pronounced in the case of stronger ground motions such as near field events as well as ground motions with longer return periods.

  12. Seismic reflection data report: Waste Isolation Pilot Plant (WIPP) site, Southeastern New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Hern, J.L.; Powers, D.W.; Barrows, L.J.

    1978-12-01

    Volume II contains uninterpreted processed lines and shotpoint maps from three seismic reflection surveys conducted from 1976 through 1978 by Sandia Laboratories to support investigations for the Waste Isolation Pilot Plant. Data interpretations will be the subject of subsequent reports. (LK)

  13. A 6-DOF vibration isolation system for hydraulic hybrid vehicles

    Science.gov (United States)

    Nguyen, The; Elahinia, Mohammad; Olson, Walter W.; Fontaine, Paul

    2006-03-01

    This paper presents the results of vibration isolation analysis for the pump/motor component of hydraulic hybrid vehicles (HHVs). The HHVs are designed to combine gasoline/diesel engine and hydraulic power in order to improve the fuel efficiency and reduce the pollution. Electric hybrid technology is being applied to passenger cars with small and medium engines to improve the fuel economy. However, for heavy duty vehicles such as large SUVs, trucks, and buses, which require more power, the hydraulic hybridization is a more efficient choice. In function, the hydraulic hybrid subsystem improves the fuel efficiency of the vehicle by recovering some of the energy that is otherwise wasted in friction brakes. Since the operation of the main component of HHVs involves with rotating parts and moving fluid, noise and vibration are an issue that affects both passengers (ride comfort) as well as surrounding people (drive-by noise). This study looks into the possibility of reducing the transmitted noise and vibration from the hydraulic subsystem to the vehicle's chassis by using magnetorheological (MR) fluid mounts. To this end, the hydraulic subsystem is modeled as a six degree of freedom (6-DOF) rigid body. A 6-DOF isolation system, consisting of five mounts connected to the pump/motor at five different locations, is modeled and simulated. The mounts are designed by combining regular elastomer components with MR fluids. In the simulation, the real loading and working conditions of the hydraulic subsystem are considered and the effects of both shock and vibration are analyzed. The transmissibility of the isolation system is monitored in a wide range of frequencies. The geometry of the isolation system is considered in order to sustain the weight of the hydraulic system without affecting the design of the chassis and the effectiveness of the vibration isolating ability. The simulation results shows reduction in the transmitted vibration force for different working cycles of

  14. Finite element prediction of seismic response modification of monumental structures utilizing base isolation

    Science.gov (United States)

    Spanos, Konstantinos; Anifantis, Nikolaos; Kakavas, Panayiotis

    2015-05-01

    The analysis of the mechanical behavior of ancient structures is an essential engineering task concerning the preservation of architectural heritage. As many monuments of classical antiquity are located in regions of earthquake activity, the safety assessment of these structures, as well as the selection of possible restoration interventions, requires numerical models capable of correctly representing their seismic response. The work presented herein was part of a research project in which a better understanding of the dynamics of classical column-architrave structures was sought by means of numerical techniques. In this paper, the seismic behavior of ancient monumental structures with multi-drum classical columns is investigated. In particular, the column-architrave classical structure under strong ground excitations was represented by a finite element method. This approach simulates the individual rock blocks as distinct rigid blocks interconnected with slidelines and incorporates seismic isolation dampers under the basement of the structure. Sliding and rocking motions of individual stone blocks and drums are modeled utilizing non-linear frictional contact conditions. The seismic isolation is modeled through the application of pad bearings under the basement of the structure. These pads are interpreted by appropriate rubber and steel layers. Time domain analyses were performed, considering the geometric and material non-linear behavior at the joints and the characteristics of pad bearings. The deformation and failure modes of drum columns subject to seismic excitations of various types and intensities were analyzed. The adverse influence of drum imperfections on structural safety was also examined.

  15. Base Isolation for Seismic Retrofitting of a Multiple Building Structure: Evaluation of Equivalent Linearization Method

    Directory of Open Access Journals (Sweden)

    Massimiliano Ferraioli

    2016-01-01

    Full Text Available Although the most commonly used isolation systems exhibit nonlinear inelastic behaviour, the equivalent linear elastic analysis is commonly used in the design and assessment of seismic-isolated structures. The paper investigates if the linear elastic model is suitable for the analysis of a seismically isolated multiple building structure. To this aim, its computed responses were compared with those calculated by nonlinear dynamic analysis. A common base isolation plane connects the isolation bearings supporting the adjacent structures. In this situation, the conventional equivalent linear elastic analysis may have some problems of accuracy because this method is calibrated on single base-isolated structures. Moreover, the torsional characteristics of the combined system are significantly different from those of separate isolated buildings. A number of numerical simulations and parametric studies under earthquake excitations were performed. The accuracy of the dynamic response obtained by the equivalent linear elastic model was calculated by the magnitude of the error with respect to the corresponding response considering the nonlinear behaviour of the isolation system. The maximum displacements at the isolation level, the maximum interstorey drifts, and the peak absolute acceleration were selected as the most important response measures. The influence of mass eccentricity, torsion, and high-modes effects was finally investigated.

  16. Vibration test report on crossover piping system in seismic isolation nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Uryu, Mitsuru; Shinohara, Takaharu; Terada, Shuji; Yamazaki, Toshihiko; Tomita, Tsuneo; Kondo, Toshinari

    1999-03-01

    In a seismic isolation nuclear facility, crossover piping system is subjected to large relative displacement and inertia forces during earthquakes. Hinged bellows expansion joints are utilized for accommodation to such the large displacement. This report describes tests for validation of developed simulation code with analytical models. Seismic experiments by a vibration test machine were conducted using actual size piping system models. A comparison between test results and analytical results showed a favorable agreement. The vibration test demonstrated that the structural integrity of this piping system would be maintained during earthquakes. (H. Itami)

  17. SHAKING TABLE TEST AND EFFECTIVE STRESS ANALYSIS ON SEISMIC PERFORMANCE WITH SEISMIC ISOLATION RUBBER TO THE INTERMEDIATE PART OF PILE FOUNDATION IN LIQUEFACTION

    Science.gov (United States)

    Uno, Kunihiko; Otsuka, Hisanori; Mitou, Masaaki

    The pile foundation is heavily damaged at the boundary division of the ground types, liquefied ground and non-liquefied ground, during an earthquake and there is a possibility of the collapse of the piles. In this study, we conduct a shaking table test and effective stress analysis of the influence of soil liquefaction and the seismic inertial force exerted on the pile foundation. When the intermediate part of the pile, there is at the boundary division, is subjected to section force, this part increases in size as compared to the pile head in certain instances. Further, we develop a seismic resistance method for a pile foundation in liquefaction using seismic isolation rubber and it is shown the middle part seismic isolation system is very effective.

  18. Characterizing the Benefits of Seismic Isolation for Nuclear Structures: A Framework for Risk-Based Decision Making

    Energy Technology Data Exchange (ETDEWEB)

    Bolisetti, Chandrakanth [Idaho National Lab. (INL), Idaho Falls, ID (United States); Yu, Chingching [Idaho National Lab. (INL), Idaho Falls, ID (United States); Coleman, Justin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Whittaker, Andrew [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kosbab, Ben [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-11-01

    This report provides a framework for assessing the benefits of seismic isolation and exercises the framework on a Generic Department of Energy Nuclear Facility (GDNF). These benefits are (1) reduction in the risk of unacceptable seismic performance and a dramatic reduction in the probability of unacceptable performance at beyond-design basis shaking, and (2) a reduction in capital cost at sites with moderate to high seismic hazard. The framework includes probabilistic risk assessment and estimates of overnight capital cost for the GDNF.

  19. Research on Hybrid Isolation System for Micro-Nano-Fabrication Platform

    Directory of Open Access Journals (Sweden)

    Jie Fu

    2014-06-01

    Full Text Available In order to obtain better vibration suppression effect, this paper designs a semiactive/fully active hybrid isolator by using magnetorheological elastomer (MRE and piezoelectric material. Combined with multimode control scheme, full frequency vibration suppression is achieved. Firstly, series type structure is determined for the hybrid isolator, and the structure of hybrid isolator is designed. Next, the dynamic model of hybrid isolator is derived, the dynamic characteristics measurement for MRE isolator and piezoelectric stack actuator (PSA is established, and parameters such as voltage-displacement coefficient, stiffness and damping constant are identified from the experimental results, respectively. Meanwhile, the switch frequency is determined by experimental results of PSA and MRE isolator. Lastly, influence of the stiffness of MRE, control voltage of PSA, and intermediate mass on hybrid isolator system is analyzed by simulations, and the results show that the hybrid isolator proposed is effective.

  20. 新疆某隔震结构的地震反应分析%Analysis of the Seismic Response of a Seismic Isolation Structure in Sinkiang

    Institute of Scientific and Technical Information of China (English)

    李红波

    2014-01-01

    本文通过对新疆某学校教学楼的时程分析,比较了其在不同地震波作用下的层间地震剪力。通过隔震与非隔震建筑的实例对比,指出了隔震结构在地震作用下的优势。并对隔震结构的设计要点进行了阐述,对于其他类似的隔震建筑设计有一定的借鉴意义。%This article through the time history analysis of the teaching building in Sinkiang and compares the different seis-mic wave under the action of seismic shear force between the layers. The author points out the advantage of the seismic iso-lation structure under seismic action through the instance cont-rast of isolation and the anti-isolation building, and elaborate the design essentials of seismic isolation structure, which has certain reference significance for other similar isolation build-ing design.

  1. Progress of a research program on seismic base isolation of nuclear components

    Energy Technology Data Exchange (ETDEWEB)

    Ebisawa, K.; Ando, K.; Shibata, K. [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan)

    2000-05-01

    Development of an evaluation code and related test program have been conducted to provide the technical base of the seismic base isolation of nuclear components. In the Phase I (FY1991-FY1995) of the research, a methodology and a computer code Ver.1 for evaluating the effect of seismic base isolation of nuclear components were developed. Case study was carried out on the effectiveness of base isolation of emergency transformer. Difference of input earthquake motion, type of isolation device and influence of the soil property were studied. Case study of a cost/benefit analysis in introducing the base isolation to emergency transformer was tried as an application of the computer code. As the Phase II (FY1996-FY2000), in order to obtain the test data of component base isolation systems, a verification test program, in which the test utilizing the real earthquake and the test by a shaking table are to be carried out, has been initiated since FY1996. In the tests, dynamic response and failure mode of base isolation systems will be examined. This paper overviews the progress of Phase I and II researches. (orig.)

  2. Effects of Moat Wall Impact on the Seismic Response of Base Isolated Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Kyu; Kim, Jung Han [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Mosqueda, Gilberto; Sarebanhab, Alireza [University of California, San Diego (United States)

    2015-10-15

    The objectives of this study are to examine the effects of impact on the response of seismically isolated NPPs and identify characteristics of the isolation hardware and hard stop that minimize these effects. Considering variable distances to the hard stop and properties of the moat wall, the amplification in response is reported for acceleration and floor spectral accelerations at different points along the height of a NPP containment structure. Base isolation can be an effective strategy to protect critical facilities such as Nuclear Power Plants (NPPs) from the damaging effects of horizontal earthquake ground shaking. To be effective in reducing accelerations and deformations of the structure above, the seismic isolation bearings can be subjected to large displacements. In the case of an extreme earthquake, bearing displacements need to be limited by a hard stop in order to prevent failure of the bearings. Impact to the hard stop, which is often the moat wall at the basement level, is also of significant concern due to the potential for increased transfer of forces and amplification in response of the structural system, piping and other contents. However, the consequences of impact or factors important to mitigate its effects are not very well understood. The main findings of this study are related to modeling of NPP with moat wall in OpenSees and LSDyna as well as observations resulting from the parametric study of the performance of the NPP under different intensity levels of seismic excitations for different properties of the moat wall and bearings. • Variation in the isolator properties should be considered when examining seismic pounding. For BDBE even, 58.5 % cases result to the impact for lower bound properties while this value was 5.5 % for upper bound properties. Since the impact results are dependent to the assumed bearing properties, a better range of properties can be obtained from experimental testing of the bearing under large shear strains.

  3. PROBABILISTIC SEISMIC ASSESSMENT OF BASE-ISOLATED NPPS SUBJECTED TO STRONG GROUND MOTIONS OF TOHOKU EARTHQUAKE

    Directory of Open Access Journals (Sweden)

    AHMER ALI

    2014-10-01

    Full Text Available The probabilistic seismic performance of a standard Korean nuclear power plant (NPP with an idealized isolation is investigated in the present work. A probabilistic seismic hazard analysis (PSHA of the Wolsong site on the Korean peninsula is performed by considering peak ground acceleration (PGA as an earthquake intensity measure. A procedure is reported on the categorization and selection of two sets of ground motions of the Tohoku earthquake, i.e. long-period and common as Set A and Set B respectively, for the nonlinear time history response analysis of the base-isolated NPP. Limit state values as multiples of the displacement responses of the NPP base isolation are considered for the fragility estimation. The seismic risk of the NPP is further assessed by incorporation of the rate of frequency exceedance and conditional failure probability curves. Furthermore, this framework attempts to show the unacceptable performance of the isolated NPP in terms of the probabilistic distribution and annual probability of limit states. The comparative results for long and common ground motions are discussed to contribute to the future safety of nuclear facilities against drastic events like Tohoku.

  4. Joint US/Japanese program of full-size building tests for base seismic isolation

    Energy Technology Data Exchange (ETDEWEB)

    Kuroda, T. (Shimizu Corp., Tokyo (Japan). Nuclear Power Div.); Chang, Y.W.; Seidensticker, R.W. (Argonne National Lab., IL (USA))

    1990-01-01

    Shimizu Corporation of Japan and Argonne National Laboratory of the USA initiated a joint research program on base seismic isolation. The program is centered on testing and analyzing isolation systems in a full-size building and to obtain data on relative response between isolated and nonisolated structures under earthquake conditions. The test facility consists of two identical full-size three-story buildings built side by side, located at Tohoku University in Sendai, Japan. Since April 1989, after the installation of bearings, over 20 earthquake data have been recorded at Sendai test facility. This paper describes the test facility, isolation bearings, observed earthquake records, and responses of isolated and nonisolated buildings under earthquake loads. 3 refs., 15 figs.

  5. Seismic Response and Performance Evaluation of Self-Centering LRB Isolators Installed on the CBF Building under NF Ground Motions

    OpenAIRE

    Junwon Seo; Jong Wan Hu

    2016-01-01

    This paper mainly treats the seismic behavior of lead-rubber bearing (LRB) isolation systems with superealstic shape memory alloy (SMA) bending bars functioning as damper and self-centering devices. The conventional LRB isolators that are usually installed at the column bases supply extra flexibility to the centrically braced frame (CBF) building with a view to elongate its vibration period, and thus make a contribution to mitigating seismic acceleration transferred from ground to structure. ...

  6. Stochastic seismic response analysis of hysteretic-friction base isolation system

    Energy Technology Data Exchange (ETDEWEB)

    Hong, F.; Wang, Q. [State Seismological Bureau, Harbin (China). Inst. of Engineering Mechanics

    1996-11-01

    A hysteretic-friction base isolation bearing, which consists of a steel rod and friction elements, is proposed in this paper. The steel rod permits the friction elements to slide in the horizontal direction, but it also limits the slide at the same time; the friction elements bear the vertical load of the superstructure. The differential equations of motion of a hysteretic-friction base isolation system are established; the hysteretic restoring force model of the steel rod is presented. The seismic response statistics of the isolation system are obtained by using the equivalent linearization method, and the influence on the response statistics of the isolation system produced by varying its parameters is analyzed.

  7. Isolated Bidirectional DC-DC Converter for Hybrid Electric Vehicle Application

    Science.gov (United States)

    2006-06-13

    34Approved for public release: distribution is unlimited" Isolated Bidirectional DC-DC Converter for Hybrid Electric Vehicle Applications Sonya...requirements for DC-DC converters for electric and hybrid vehicles . This paper introduces a bidirectional, isolated DC-DC converter for medium power...the design and build of a medium power DC-DC converter . Key words: Power Converter , DC-DC, Hybrid Electric Vehicle , Battery, Galvanically Isolation

  8. Proposed Activities to Address Regulatory Gaps and Challenges for Licensing Advanced Reactors Using Seismic Isolation

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Justin Leigh [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kammerer, Annie M. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Whittaker, Andrew S. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-12-01

    Over the last decade, particularly since implementation of the certified design regulatory approaches outlined in 10 CFR 52, “Licenses, Certifications, and Approvals for Nuclear Power Plants,” interest has been increasing in the use of seismic isolation (SI) technology to support seismic safety in nuclear facilities. In 2009, the United States (U.S.) Nuclear Regulatory Commission (NRC) initiated research activities to develop new guidance targeted at isolated facilities because SI is being considered for nuclear power plants in the U.S. One product of that research, which was developed around a risk-informed regulatory approach, is a draft NRC NUREG series (NUREG/CR) report that investigates and discusses considerations for use of SI in otherwise traditionally founded large light water reactors (LWRs). A coordinated effort led to new provisions for SI of LWRs in the American Society of Civil Engineers standard ASCE/SEI 4-16, “Seismic Analysis of Safety Related Nuclear Structures.” The risk-informed design philosophy that underpinned development of the technical basis for these documents led to a set of proposed performance objectives and acceptance criteria intended to serve as the foundation for future NRC guidance on the use of SI and related technology. Although the guidance provided in the draft SI NUREG/CR report and ASCE/SEI 4 16 provides a sound basis for further development of nuclear power plant designs incorporating SI, these initial documents were focused on surface-founded or near-surface-founded LWRs and were, necessarily, limited in scope. For example, there is limited information in both the draft NUREG/CR report and ASCE/SEI 4-16 related to nonlinear analysis of soil-structure systems for deeply-embedded reactors, the isolation of components, and the use of vertical isolation systems. Also not included in the draft SI NUREG/CR report are special considerations for licensing of isolated facilities using the certified design approach in 10 CFR

  9. Seismic response analysis of a piping system subjected to multiple support excitations in a base isolated NPP building

    Energy Technology Data Exchange (ETDEWEB)

    Surh, Han-Bum [School of Mechanical Engineering, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon 440-746 (Korea, Republic of); Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Ryu, Tae-Young; Park, Jin-Sung [School of Mechanical Engineering, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon 440-746 (Korea, Republic of); Ahn, Eun-Woo; Choi, Chul-Sun [Korea Electric Power Corporation Engineering & Construction Company, Inc., 2354 Yonggu-daero, Giheung-gu, Yongin 446-713 (Korea, Republic of); Koo, Ja Choon [School of Mechanical Engineering, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon 440-746 (Korea, Republic of); Choi, Jae-Boong [School of Mechanical Engineering, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon 440-746 (Korea, Republic of); SKKU Advanced Institute of Nanotechnology, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon 440-746 (Korea, Republic of); Kim, Moon Ki, E-mail: mkkim@me.skku.ac.kr [School of Mechanical Engineering, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon 440-746 (Korea, Republic of); SKKU Advanced Institute of Nanotechnology, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon 440-746 (Korea, Republic of)

    2015-10-15

    Highlights: • Piping system in the APR 1400 NPP with a base isolation design is studied. • Seismic response of piping system in base isolated building are investigated. • Stress classification method is examined for piping subjected to seismic loading. • Primary stress of piping is reduced due to base isolation design. • Substantial secondary stress is observed in the main steam piping. - Abstract: In this study, the stress response of the piping system in the advanced power reactor 1400 (APR 1400) with a base isolation design subjected to seismic loading is addressed. The piping system located between the auxiliary building with base isolation and the turbine building with a fixed base is considered since it can be subjected to substantial relative support movement during seismic events. First, the support responses with respect to the base characteristic are investigated to perform seismic analysis for multiple support excitations. Finite element analyses are performed to predict the piping stress response through various analysis methods such as the response spectrum, seismic support movement and time history method. To separately evaluate the inertial effect and support movement effect on the piping stress, the stress is decomposed into a primary and secondary stress using the proposed method. Finally, influences of the base isolation design on the piping system in the APR 1400 are addressed. The primary stress based on the inertial loading is effectively reduced in a base isolation design, whereas a considerable amount of secondary stress is generated in the piping system connecting a base isolated building with a fixed base building. It is also confirmed that both the response spectrum analysis and seismic support movement analysis provide more conservative estimations of the piping stress compared to the time history analysis.

  10. Seismic response evaluation of base-isolated reinforced concrete buildings under bidirectional excitation

    Science.gov (United States)

    Bhagat, Satish; Wijeyewickrema, Anil C.

    2017-04-01

    This paper reports on an investigation of the seismic response of base-isolated reinforced concrete buildings, which considers various isolation system parameters under bidirectional near-fault and far-fault motions. Three-dimensional models of 4-, 8-, and 12-story base-isolated buildings with nonlinear effects in the isolation system and the superstructure are investigated, and nonlinear response history analysis is carried out. The bounding values of isolation system properties that incorporate the aging effect of isolators are also taken into account, as is the current state of practice in the design and analysis of base-isolated buildings. The response indicators of the buildings are studied for near-fault and far-fault motions weight-scaled to represent the design earthquake (DE) level and the risk-targeted maximum considered earthquake (MCER) level. Results of the nonlinear response history analyses indicate no structural damage under DE-level motions for near-fault and far-fault motions and for MCER-level far-fault motions, whereas minor structural damage is observed under MCER-level near-fault motions. Results of the base-isolated buildings are compared with their fixed-base counterparts. Significant reduction of the superstructure response of the 12-story base-isolated building compared to the fixed-base condition indicates that base isolation can be effectively used in taller buildings to enhance performance. Additionally, the applicability of a rigid superstructure to predict the isolator displacement demand is also investigated. It is found that the isolator displacements can be estimated accurately using a rigid body model for the superstructure for the buildings considered.

  11. Hybrid female mate choice as a species isolating mechanism: environment matters.

    Science.gov (United States)

    Schmidt, E M; Pfennig, K S

    2016-04-01

    A fundamental goal of biology is to understand how new species arise and are maintained. Female mate choice is potentially critical to the speciation process: mate choice can prevent hybridization and thereby generate reproductive isolation between potentially interbreeding groups. Yet, in systems where hybridization occurs, mate choice by hybrid females might also play a key role in reproductive isolation by affecting hybrid fitness and contributing to patterns of gene flow between species. We evaluated whether hybrid mate choice behaviour could serve as such an isolating mechanism using spadefoot toad hybrids of Spea multiplicata and Spea bombifrons. We assessed the mate preferences of female hybrid spadefoot toads for sterile hybrid males vs. pure-species males in two alternative habitat types in which spadefoots breed: deep or shallow water. We found that, in deep water, hybrid females preferred the calls of sterile hybrid males to those of S. multiplicata males. Thus, maladaptive hybrid mate preferences could serve as an isolating mechanism. However, in shallow water, the preference for hybrid male calls was not expressed. Moreover, hybrid females did not prefer hybrid calls to those of S. bombifrons in either environment. Because hybrid female mate choice was context-dependent, its efficacy as a reproductive isolating mechanism will depend on both the environment in which females choose their mates as well as the relative frequencies of males in a given population. Thus, reproductive isolation between species, as well as habitat specific patterns of gene flow between species, might depend critically on the nature of hybrid mate preferences and the way in which they vary across environments.

  12. Seismic base isolation of gas insulated electrical substations: Comparison among different solutions

    Energy Technology Data Exchange (ETDEWEB)

    Serino, G. [Univ. di Napoli Federico II (Italy). Dipt. di Analisi e Progettazione Strutturale; Bettinali, F. [ENEL s.p.a., Milano (Italy). Centro di Ricerca Idraulica e Strutturale; Bonacina, G. [ISMES s.p.a., Seriate (Italy). Div. Indagini Strutturali

    1995-12-31

    Base isolation of an outdoor 170 kV Gas-Insulated Substation conforming to ENEL standardization is proposed. The analyzed GIS has two separated phases and its layout consists of a compact block composed of five bays and two High-to-Medium Voltage power transformers. The design has been carried out following the International Electrotechnical Commission (IEC) requirements for seismic qualification of HV equipment. Three solutions are presented, each making use of different isolation devices: High-Damping Steel-Laminated Rubber Bearings, helical springs and visco-dampers, Friction Pendulu devices. The procedures adopted in the design of the three isolation systems are briefly explained, pointing out advantages and drawbacks of each solution.

  13. Summary of experimental tests of elastomeric seismic isolation bearings for use in nuclear reactor plants

    Energy Technology Data Exchange (ETDEWEB)

    Seidensticker, R.W.; Chang, Y.W.; Kulak, R.F.

    1992-05-01

    This paper describes an experimental test program for isolator bearings which was developed to help establish the viability of using laminated elastomer bearings for base isolation of nuclear reactor plants. The goal of the test program is to determine the performance characteristics of laminated seismic isolation bearings under a wide range of loadings. Tests were performed on scale-size laminated seismic isolators both within the design shear strain range to determine the response of the bearing under expected earthquake loading conditions, and beyond the design range to determine failure modes and to establish safety margins. Three types of bearings, each produced from a different manufacturer, have been tested: (1) high shape factor-high damping-high shear modulus bearings; (2) medium shape factor-high damping-high shear modulus bearings; and (3) medium shape factor-high damping-low shear modulus bearings. All of these tests described in this report were performed at the Earthquake Engineering Research Center at the University of California, Berkeley, with technical assistance from ANL. The tests performed on the three types of bearings have confirmed the high performance characteristics of the high damping-high and low shear modulus elastomeric bearings. The bearings have shown that they are capable of having extremely large shear strains before failure occurs. The most common failure mechanism was the debonding of the top steel plate from the isolators. This failure mechanism can be virtually eliminated by improved manufacturing quality control. The most important result of the failure test of the isolators is the fact that bearings can sustain large horizontal displacement, several times larger than the design value, with failure. Their performance in moderate and strong earthquakes will be far superior to conventional structures.

  14. Summary of experimental tests of elastomeric seismic isolation bearings for use in nuclear reactor plants

    Energy Technology Data Exchange (ETDEWEB)

    Seidensticker, R.W.; Chang, Y.W.; Kulak, R.F.

    1992-01-01

    This paper describes an experimental test program for isolator bearings which was developed to help establish the viability of using laminated elastomer bearings for base isolation of nuclear reactor plants. The goal of the test program is to determine the performance characteristics of laminated seismic isolation bearings under a wide range of loadings. Tests were performed on scale-size laminated seismic isolators both within the design shear strain range to determine the response of the bearing under expected earthquake loading conditions, and beyond the design range to determine failure modes and to establish safety margins. Three types of bearings, each produced from a different manufacturer, have been tested: (1) high shape factor-high damping-high shear modulus bearings; (2) medium shape factor-high damping-high shear modulus bearings; and (3) medium shape factor-high damping-low shear modulus bearings. All of these tests described in this report were performed at the Earthquake Engineering Research Center at the University of California, Berkeley, with technical assistance from ANL. The tests performed on the three types of bearings have confirmed the high performance characteristics of the high damping-high and low shear modulus elastomeric bearings. The bearings have shown that they are capable of having extremely large shear strains before failure occurs. The most common failure mechanism was the debonding of the top steel plate from the isolators. This failure mechanism can be virtually eliminated by improved manufacturing quality control. The most important result of the failure test of the isolators is the fact that bearings can sustain large horizontal displacement, several times larger than the design value, with failure. Their performance in moderate and strong earthquakes will be far superior to conventional structures.

  15. Experimental and analytical studies on the seismic behavior of conventional and hybrid braced frames

    Science.gov (United States)

    Lai, Jiun-Wei

    This dissertation summarizes both experimental and analytical studies on the seismic response of conventional steel concentrically braced frame systems of the type widely used in North America, and preliminary studies of an innovative hybrid braced frame system: the Strong-Back System. The research work is part of NEES small group project entitled "International Hybrid Simulation of Tomorrow's Braced Frames." In the experimental phase, a total of four full-scale, one-bay, two-story conventional braced frame specimens with different bracing member section shapes and gusset plate-to-beam connection details were designed and tested at the NEES Berkeley Laboratory. Three braced frame specimens were tested quasi-statically using the same predefined loading protocol to investigate the inelastic cyclic behavior of code-compliant braced frames at both the global and local level. The last braced frame specimen was nearly identical to one of those tested quasi-statically. However, it was tested using hybrid simulation techniques to examine the sensitivity of inelastic behavior on loading sequence and to relate the behavior observed to different levels of seismic hazard. Computer models of the test specimens were developed using two different computer software programs. In the software framework OpenSees fiber-based line elements were used to simulate global buckling of members and yielding and low-cycle fatigue failure at sections. The LS-DYNA analysis program was also used to model individual struts and the test specimens using shell elements with adaptive meshing and element erosion features. This program provided enhanced ability to simulate section local buckling, strain concentrations and crack development. The numerical results were compared with test results to assess and refine and the ability of the models to predict braced frame behavior. A series of OpenSees numerical cyclic component simulations were then conducted using the validated modeling approach. Two

  16. A periodic foundation with rotational oscillators for extremely low-frequency seismic isolation: analysis and experimental verification

    Science.gov (United States)

    Huang, Jiankun; Shi, Zhifei; Huang, Weixin; Chen, Xinhua; Zhang, Zhiwei

    2017-03-01

    A new type of periodic foundation (PF) with rotational oscillators was developed, and its locally resonant attenuation feature was analyzed numerically and experimentally. The proposed PF was composed of a concrete matrix in which local resonators consisting of steel cores with rubber linkers were attached. Finite element method was employed to comprehensively investigate influences of material and geometrical parameters on the attenuation zones. Furthermore, a scaled PF was fabricated and shake tests were performed. The locally resonant mechanism within the rotational resonator can produce extremely low-frequency wave-forbidding capability. The results demonstrated that a PF can isolate seismic waves with frequencies lower than 10 Hz, sufficient to serve as a seismic isolation foundation for civil engineering structures. This kind of foundation system opens up new perspectives for the development of seismic isolation foundations for low-frequency applications.

  17. Performance evaluation of shape memory alloy/rubber-based isolation systems for seismic response mitigation of bridges

    Science.gov (United States)

    Ozbulut, Osman E.; Hurlebaus, Stefan

    2010-04-01

    Base isolation is an effective method of reducing seismic response of bridges during an earthquake. Rubber isolators are one of the most common types of base isolation systems. As an alternative to conventional rubber isolators such as high damping rubber bearing and lead rubber bearing, smart rubber bearing systems with shape memory alloys (SMAs) have been proposed in recent years. As a class of smart materials, shape memory alloys shows excellent re-centering and considerable damping capabilities which can be exploited to obtain an efficient seismic isolation system. This paper explores effectiveness of shape memory alloy/rubber-based isolation systems for protecting bridges against seismic loads by performing a sensitivity analysis. The isolation system considered in this study consists of a laminated rubber bearing which provides lateral flexibility while supplying high vertical load-carrying capacity and an auxiliary device made of multiple loops SMA wires. The SMA device offers additional energy dissipating and re-centering capability. A threespan continuous bridge is modeled with SMA/rubber-based isolation system. Numerical simulations of the bridge are conducted for various historical ground motions that are spectrally matched to a target design spectrum. The normalized yield strength, yield displacement and pre-stress level of the SMA device and ambient temperature are selected as parameters of the sensitivity study. The variation of seismic response of the bridge with considered parameters is assessed. The optimum values of the normalized yield strength and the yield displacement of the SMA device is found to be in the range of 0.20-0.25 and 40-50 mm, respectively. Also, the SMA/rubber-based isolation system is observed to be more effective when the SMA device is pre-stressed. In addition, it is found that ambient temperature considerably affects the performance of the bridge isolated by SMA/rubber-based isolators.

  18. Seismic Response and Performance Evaluation of Self-Centering LRB Isolators Installed on the CBF Building under NF Ground Motions

    Directory of Open Access Journals (Sweden)

    Junwon Seo

    2016-01-01

    Full Text Available This paper mainly treats the seismic behavior of lead-rubber bearing (LRB isolation systems with superealstic shape memory alloy (SMA bending bars functioning as damper and self-centering devices. The conventional LRB isolators that are usually installed at the column bases supply extra flexibility to the centrically braced frame (CBF building with a view to elongate its vibration period, and thus make a contribution to mitigating seismic acceleration transferred from ground to structure. However, these base isolation systems are somehow susceptible to shear failure due to the lack of lateral resistance. In the construction site, they have been used to be integrated with displacement control dampers additionally withstanding lateral seismic forces. For this motivation, LRB isolation systems equipped with superelastic SMA bending bars, which possess not only excellent energy dissipation but also outstanding recentering capability, are proposed in this study. These reinforced and recentering LRB base isolators are modeled as nonlinear component springs, and then assigned into the bases of 2D frame models used for numerical simulation. Their seismic performance and capacity in the base-isolated frame building can be evaluated through nonlinear dynamic analyses conducted with historic ground motion data. After comparative study with analyses results, it is clearly shown that 2D frame models with proposed LRB isolators generally have smaller maximum displacements than those with conventional LRB isolators. Furthermore, the LRB isolation systems with superelastic SMA bending bars effectively reduce residual displacement as compared to those with steel bending bars because they provide more flexibility and recentering force to the entire building structure.

  19. Seismic Response Prediction of Buildings with Base Isolation Using Advanced Soft Computing Approaches

    Directory of Open Access Journals (Sweden)

    Mosbeh R. Kaloop

    2017-01-01

    Full Text Available Modeling response of structures under seismic loads is an important factor in Civil Engineering as it crucially affects the design and management of structures, especially for the high-risk areas. In this study, novel applications of advanced soft computing techniques are utilized for predicting the behavior of centrically braced frame (CBF buildings with lead-rubber bearing (LRB isolation system under ground motion effects. These techniques include least square support vector machine (LSSVM, wavelet neural networks (WNN, and adaptive neurofuzzy inference system (ANFIS along with wavelet denoising. The simulation of a 2D frame model and eight ground motions are considered in this study to evaluate the prediction models. The comparison results indicate that the least square support vector machine is superior to other techniques in estimating the behavior of smart structures.

  20. Design and experimental verification of a new multi-functional bridge seismic isolation bearing

    Institute of Scientific and Technical Information of China (English)

    Chen-xi XING; Hao WANG; Ai-qun LI; Ji-rong WU

    2012-01-01

    A new multi-functional bridge seismic isolation bearing (MFBSIB) is designed and its mechanical model is developed in this paper.Combining an upper sliding device and a lower energy dispassion isolation device effectively,the new MFBSIB can adjust the deformation caused by temperature,vehicle breaks,and concrete creep,etc.,in addition to dissipating energy.The switch of ‘slide-isolation' is achieved and the efficiency of both upper and lower parts is validated through experiment with a model.The shear performance curve established in this paper is verified to be efficient in describing the mechanical characteristics of the bearing through experiment.It is proved through both numerical calculation and experimental analysis that the new MFBSIB is endowed with enough vertical rigidity,good energy dissipation ability,stable overall performance,and good realization in expected goals.Its performance is slightly influenced by shear stress,while affected by vertical pressure,loading frequency,slide limit,etc.,diversely.The results could provide reference for study and application of the new MFBSIB.

  1. Seismic Response of Base-Isolated High-Rise Buildings under Fully Nonstationary Excitation

    Directory of Open Access Journals (Sweden)

    C. F. Ma

    2014-01-01

    Full Text Available Stochastic seismic responses of base-isolated high-rise buildings subjected to fully nonstationary earthquake ground motion are computed by combining the pseudoexcitation and the equivalent linearization methods, and the accuracy of results obtained by the pseudoexcitation method is verified by the Monte Carlo method. The superstructure of a base-isolated high-rise building is represented by a finite element model and a shear-type multi-degree of freedom model, respectively. The influence of the model type and the number of the modes of the superstructure participating in the computation of the dynamic responses of the isolated system has been investigated. The results of a 20-storey, 3D-frame with height to width ratio of 4 show that storey drifts and absolute accelerations of the superstructure for such a high-rise building will be substantially underestimated if the shear-type multi-degree of freedom model is employed or the higher modes of the superstructure are neglected; however, this has nearly no influence on the drift of the base slab.

  2. Utilities/industries joint study on seismic isolation systems for LWRs. Pt. 2; Observed behaviors of base-isolated general buildings under real earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Matsumura, Takao; Sato, Shoji; Kato, Muneaki (Kansai Electric Power Co., Inc., Osaka (Japan))

    1991-06-01

    This paper describes the observed behavior of base-isolated buildings under real earthquake conditions. These buildings were constructed by five construction companies participating in the Joint Study on Seismic Isolation Systems for light-water reactors (LWRs). All the buildings are medium- or low-height buildings or reinforced-concrete structures with combinations of laminated rubber bearings or sliding bearings and various damping devices. (orig.).

  3. On selection and scaling of ground motions for analysis of seismically isolated structures

    Science.gov (United States)

    Pant, Deepak R.; Maharjan, Manika

    2016-12-01

    A broader consensus on the number of ground motions to be used and the method of scaling to be adopted for nonlinear response history analysis (RHA) of structures is yet to be reached. Therefore, in this study, the effects of selection and scaling of ground motions on the response of seismically isolated structures, which are routinely designed using nonlinear RHA, are investigated. For this purpose, isolation systems with a range of properties subjected to bidirectional excitation are considered. Benchmark response of the isolation systems is established using large sets of unscaled ground motions systematically categorized into pulse-like, non-pulse-like, and mixed set of motions. Different subsets of seven to 14 ground motions are selected from these large sets using (a) random selection and (b) selection based on the best match of the shape of the response spectrum of ground motions to the target spectrum. Consequences of weighted scaling (also commonly referred to as amplitude scaling or linear scaling) as well as spectral matching are investigated. The ground motion selection and scaling procedures are evaluated from the viewpoint of their accuracy, efficiency, and consistency in predicting the benchmark response. It is confirmed that seven time histories are sufficient for a reliable prediction of isolation system displacement demands, for all ground motion subsets, selection and scaling procedures, and isolation systems considered. If ground motions are selected based on their best match to the shape of the target response spectrum (which should be preferred over randomly selected motions), weighted scaling should be used if pulse-like motions are considered, either of weighted scaling or spectral matching can be used if non-pulse-like motions are considered, and an average of responses from weighted-scaled and spectrum-matched ground motions should be used for a mixed set of motions. On the other hand, the importance of randomly selected motions in

  4. Characteristic evaluation of high compression seismic isolator for International Thermonuclear Experimental Reactor (ITER). Verification test of sub-scaled rubber bearings. Contract research

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Hiroyuki [Hitachi Ltd., Tokyo (Japan); Nakahira, Masataka [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Yabana, Shuichi; Matsuda, Akihiro; Ohtori, Yasuki [Central Research Inst. of Electric Power Industry, Tokyo (Japan)

    2001-11-01

    The International Thermonuclear Experimental Reactor (ITER) is designed to withstand the seismic load of 2 m/s{sup 2} at the ground level as a standard seismic condition. In case of severe seismic load over 2 m/s{sup 2}, an application of the seismic isolation to the tokamak building is studied so as to reduce the seismic load below 2 m/s{sup 2}. The seismic isolation with high compressive pressure of 7.35MPa to 14.7MPa is considered as a candidate, because the tokamak weight is large to the building size and the number of seismic isolator (rubber bearing) is limited in the available space of the building. Although many studies were executed in the past in order to apply the seismic isolation to the nuclear plant, the test data can not be applied to the ITER due to low compressive pressure of about 2.45MPa to 4.90MPa. Based on the above, it is therefore necessary to evaluate the various kinds of dynamic and mechanical characteristics of the rubber bearings under the high compressive pressure and to obtain the database for the design of the seismic isolation system of the ITER. The report describes the summary of the test results of the sub-scaled rubber bearings executed under the high compression condition in 1997 to 1999. (author)

  5. Applicability of superelastic materials in seismic protection systems: a parametric study of performance in isolation of structures

    Science.gov (United States)

    Soul, H.; Yawny, A.

    2017-08-01

    The dynamic response to different seismic inputs of an isolated structure disposed on a sliding layer and connected to the ground with a superelastic NiTi device was analyzed. The device allows wires of NiTi to be mechanically cycled by supporting externally applied tension/compression forces exploiting both dissipative and self-centering capabilities associated with superelasticity. Simulations were carried out modifying the wires length and the structural mass. Both parameters were varied over two orders of magnitude with the aim of evaluating the type of response, the mitigation level that can be accomplished and the combination of parameters resulting in an optimal response. Results indicate that the proposed device is suitable for seismic protection of isolated structures and it is demonstrated that the protective action is more related with the restraining and self-centering properties of the NiTi superelastic wires than with its damping capacity.

  6. Ultrasonic Lateral Displacement Sensor for Health Monitoring in Seismically Isolated Buildings.

    Science.gov (United States)

    Matsuya, Iwao; Matsumoto, Fumiya; Ihara, Ikuo

    2015-07-13

    An ultrasonic lateral displacement sensor utilizing air-coupled ultrasound transducers is proposed. The normally-distributed far field of an ultrasound transducer in a lateral direction is taken advantage of for measuring lateral displacement. The measurement system is composed of several air-coupled ultrasound transducers as a receiver and several transmitters. The transmitters are immobilized at a fixed point, whereas the receiver set-up is separately arranged on the opposite side. In order to improve measurement accuracy, a correction method that utilizes polynomial approximation is introduced. The difference between the corrected lateral displacement and the reference displacement is estimated to be 0.2 mm at maximum for the two transmitters system. A good responsiveness is demonstrated by conducting a dynamic response experiment. When five transmitters are arranged, their measurement range is easily extended up to ±60 mm with an accuracy of 0.7 mm. In both cases, the fluctuations to the measurement ranges show less than 1%. These results indicate that the developed sensor system is useful for measuring relative lateral displacement of a seismically isolated building in the field of structural health monitoring.

  7. Numerical Simulations of Lightning Surge Responses in a Seismic Isolated Building by FDTD and EMTP

    Science.gov (United States)

    Nagaoka, Naoto; Morita, Hiroshi; Baba, Yoshihiro; Ametani, Akihiro

    Current distribution and overvoltages in a structure of a seismic isolated building struck by lightning are analyzed by a Finite-Difference Time-Domain (FDTD) method and by the Electromagnetic Transients Program (EMTP). The simulated results by the FDTD method show that the voltage at the first floor, which is an important factor of a design of building installation, shows a damped oscillatory wave. The transient overvoltage is caused by the multiple reflections within the structures and the resonance between a stray capacitance of the structure and an equivalent inductance of the bonding wire, which electrically shunts a rubber insulator installed for dumping earthquake tremor. The investigation shows that the transient response can be expressed by a lumped-parameter equivalent circuit. Two numerical models for circuit analysis method are proposed in this paper. A multiphase model reproduces a distribution of currents flowing through vertical pillars by mutual couplings between the pillars. A single phase model is obtained by a simplification of the multiphase model and gives the voltage at the first floor. The calculation time is remarkably reduced compared to that by the FDTD method. The accuracy of the models is discussed in comparison with the results obtained by the FDTD method.

  8. Ultrasonic Lateral Displacement Sensor for Health Monitoring in Seismically Isolated Buildings

    Directory of Open Access Journals (Sweden)

    Iwao Matsuya

    2015-07-01

    Full Text Available An ultrasonic lateral displacement sensor utilizing air-coupled ultrasound transducers is proposed. The normally-distributed far field of an ultrasound transducer in a lateral direction is taken advantage of for measuring lateral displacement. The measurement system is composed of several air-coupled ultrasound transducers as a receiver and several transmitters. The transmitters are immobilized at a fixed point, whereas the receiver set-up is separately arranged on the opposite side. In order to improve measurement accuracy, a correction method that utilizes polynomial approximation is introduced. The difference between the corrected lateral displacement and the reference displacement is estimated to be 0.2 mm at maximum for the two transmitters system. A good responsiveness is demonstrated by conducting a dynamic response experiment. When five transmitters are arranged, their measurement range is easily extended up to ±60 mm with an accuracy of 0.7 mm. In both cases, the fluctuations to the measurement ranges show less than 1%. These results indicate that the developed sensor system is useful for measuring relative lateral displacement of a seismically isolated building in the field of structural health monitoring.

  9. Financial aspects of a seismic base isolation system for a steel high-rack structure

    Directory of Open Access Journals (Sweden)

    Kilar, V.

    2013-12-01

    Full Text Available The paper deals with the effects and costs of implementing a base isolation system for the mitigation of the seismic risk of an existing steel rack structure. Different realistic distributions of the payload mass and occupancy levels, which form different plan asymmetric variants, have been analysed. The results obtained by the pushover analysis (N2 method are presented as top floor envelopes and as plastic hinge damage patterns. In the presented cost study, the cost of the implementation of the proposed base isolation system is compared with the estimated costs of structural repairs to the damaged structural members of the superstructure, as well as with estimated expenses of the downtime period. The results have shown that base isolation is, in general, not economically feasible for lower ground motion intensities, whereas it could be of great benefit in the case of moderate and high intensities, especially if the downtime period is taken into account.El presente artículo trata sobre los efectos y costes de implementación de un sistema de aislamiento en cimentación para la mitigación del riesgo sísmico de la estructura de un bastidor de acero en altura prexistente. Se han analizado diferentes distribuciones realistas de la masa contribuyente y de los niveles de ocupación, conformando diferentes variantes asimétricas en planta. Se presentan los resultados obtenidos mediante el método N2 (análisis estático incremental no lineal como envolventes de las plantas superiores y como patrones de deterioro en estado plástico. En el estudio de costos presentado, el coste de implementación del sistema de aislamiento propuesto se compara con los costes estimados de reparación de los elementos superestructurales y los costes derivados del período de desocupación. Los resultados muestran que, en general, el aislamiento en la base no resulta viable económicamente para movimientos de baja intensidad, pero puede ser muy beneficioso en el caso de

  10. Hybridization experiments indicate incomplete reproductive isolating mechanism between Fasciola hepatica and Fasciola gigantica.

    Science.gov (United States)

    Itagaki, T; Ichinomiya, M; Fukuda, K; Fusyuku, S; Carmona, C

    2011-09-01

    Experiments on hybridization between Fasciola hepatica and Fasciola gigantica were carried out to clarify whether a reproductive isolating mechanism appears between the two Fasciola species. Molecular evidence for hybridization was based on the DNA sequence of the internal transcribed spacer 1 (ITS1) region in nuclear ribosomal DNA, which differs between the species. The results suggested that there were not pre-mating but post-mating isolating mechanisms between the two species. However, viable adults of the hybrids F1 and F2 were produced from both parental F. hepatica and F. gigantica. The hybrids inherited phenotypic characteristics such as ratio of body length and width and infectivity to rats from parental Fasciola hepatica and F. gigantica. These findings suggest that reproductive isolation is incomplete between Fasciola hepatica and F. gigantica. Adults of the hybrids F1 and F2 were completely different in mode of reproduction from aspermic Fasciola forms that occur in Asia and seem to be offspring originated from hybridization between F. hepatica and F. gigantica and to reproduce parthenogenetically.

  11. The Role of Environmental Heterogeneity in Maintaining Reproductive Isolation between Hybridizing Passerina (Aves: Cardinalidae Buntings

    Directory of Open Access Journals (Sweden)

    Matthew D. Carling

    2012-01-01

    Full Text Available Hybrid zones are useful systems in which to investigate processes important in creating and maintaining biological diversity. As they are often located in ecotones, patterns of environmental heterogeneity may influence hybridization, and may also influence the maintenance of reproductive isolation between hybridizing species. Focusing on the hybrid zone between Passerina amoena (Lazuli Bunting and Passerina cyanea (Indigo Bunting, located in the eastern Rocky Mountain/western Great Plains ecotone, we examined the relationship between population-pairwise differences in the proportion of hybrids and environmental variation. Models including environmental variables explained more of the variation in hybridization rates across the ecotone than did models that only included the geographic distance between sampling localities as predictor variables (63.9% and 58.9% versus 38.8% and 39.9%, depending on how hybridization was quantified. In the models including environmental variables, the amount of rainfall during the warmest quarter had the greatest explanatory power, consistent with a hypothesis that P. cyanea is better adapted to the mesic environments of eastern North America and P. amoena is better adapted to the xeric habitats of western North America. These results suggest that continued reproductive isolation between these species is mediated, at least partially, by differential adaptations to local environmental conditions.

  12. Study of the seismic performance of hybrid A-frame micropile/MSE (mechanically stabilized earth) wall

    Science.gov (United States)

    Chen, Yumin; Zhang, Zhichao; Liu, Hanlong

    2017-04-01

    The Hybrid A-Frame Micropile/MSE (mechanically stabilized earth) Wall suitable for mountain roadways is put forward in this study: a pair of vertical and inclined micropiles goes through the backfill region of a highway MSE Wall from the road surface and are then anchored into the foundation. The pile cap and grade beam are placed on the pile tops, and then a road barrier is connected to the grade beam by connecting pieces. The MSE wall's global stability, local stability and impact resistance of the road barrier can be enhanced simultaneously by this design. In order to validate the serviceability of the hybrid A-frame micropile/MSE wall and the reliability of the numerical method, scale model tests and a corresponding numerical simulation were conducted. Then, the seismic performance of the MSE walls before and after reinforcement with micropiles was studied comparatively through numerical methods. The results indicate that the hybrid A-frame micropile/MSE wall can effectively control earthquake-induced deformation, differential settlement at the road surface, bearing pressure on the bottom and acceleration by means of a rigid-soft combination of micropiles and MSE. The accumulated displacement under earthquakes with amplitude of 0.1‒0.5 g is reduced by 36.3%‒46.5%, and the acceleration amplification factor on the top of the wall is reduced by 13.4%, 15.7% and 19.3% based on 0.1, 0.3 and 0.5 g input earthquake loading, respectively. In addition, the earthquake-induced failure mode of the MSE wall in steep terrain is the sliding of the MSE region along the backslope, while the micropiles effectively control the sliding trend. The maximum earthquake-induced pile bending moment is in the interface between MSE and slope foundation, so it is necessary to strengthen the reinforcement of the pile body in the interface. Hence, it is proven that the hybrid A-frame micropile/MSE wall system has good seismic performance.

  13. Absence of postzygotic isolating mechanisms: evidence from experimental hybridization between two species of tropical sea urchins

    Institute of Scientific and Technical Information of China (English)

    M.Aminur RAHMAN; Tsuyoshi UEHARA; Aziz ARSHAD; Fatimah Md.YUSOFF; Mariana Nor SHAMSUDIN

    2012-01-01

    Two reef margin species of tropical sea urchins,Echinometra sp.C (Ec) and Echinometra oblonga (Eo),occur sympatrically on Okinawa intertidal reefs in southern Japan.Hybridization between these species was examined through a series of cross-fertilization experiments.At limited sperm concentrations,where conspecific crosses reached near 100% fertilization,both heterospecific crosses showed high fertilization rates (81%-85%).The compatibility of the gametes demonstrated that if gamete recognition molecules are involved in fertilization of these species,they are not strongly species-specific.We found that conspecific crosses reached peak fertilization levels much faster than did heterospecific crosses,indicating the presence of a prezygotic barrier to hybridization in the gametes.Larval survival,metamorphosis,and juvenile and adult survival of hybrid groups were nearly identical to those of their parent species.Hybrids from crosses in both directions developed normally through larval stages to sexually mature adults,indicating that neither gametic incompatibility nor hybrid inviability appeared to maintain reproductive isolation between these species.In adults,Ec×Ec crosses gave the highest live weight,followed by Eo (ova)×Ec (sperm),Ec (ova)×Eo (sperm),and Eo×Eo.Other growth performance measures (viz.,test size,Aristotle's lantern length,and gonad index) of hybrid groups and their parental siblings showed the same trends.The phenotypic color patterns of the hybrids were closer to the maternal coloration,whereas spine length,tube-foot and gonad spicule characteristics,pedicellaria valve length,and gamete sizes showed intermediate features.Adult F1 hybrids were completely fertile and displayed high fertilization success in F1 backcrosses,eliminating the likelihood that hybrid sterility is a postzygotic mechanism of reproductive isolation.Conversely,intensive surveys failed to find hybrid individuals in the field,suggesting the lack or rarity of natural

  14. A hybrid fault detection and isolation strategy for a team of cooperating unmanned vehicles

    Science.gov (United States)

    Tousi, M. M.; Khorasani, K.

    2015-01-01

    In this paper, a hybrid fault detection and isolation (FDI) methodology is developed for a team of cooperating unmanned vehicles. The proposed approach takes advantage of the cooperative nature of the team to detect and isolate relatively low-severity actuator faults that are otherwise not detectable and isolable by the vehicles themselves individually. The approach is hybrid and consists of both low-level (agent/team level) and high-level [discrete-event systems (DES) level] FDI modules. The high-level FDI module is formulated in the DES supervisory control framework, whereas the low-level FDI module invokes classical FDI techniques. By properly integrating the two FDI modules, a larger class of faults can be detected and isolated as compared to the existing techniques in the literature that rely on each level separately. Simulation results for a team of five unmanned aerial vehicles are also presented to demonstrate the effectiveness and capabilities of our proposed methodology.

  15. Hybrid Active and Passive Control of Vibratory Power Flow in Flexible Isolation System

    Directory of Open Access Journals (Sweden)

    Y.P. Xiong

    2000-01-01

    Full Text Available A hybrid active and passive vibration control strategy is developed to reduce the total power flows from machines, subject to multiple excitations, to supporting flexible structures. The dynamic interactions between machines, controllers, and receiving structures are studied. A force feedback control process governed by a proportional control law is adopted to produce active control forces to cancel the transmitted forces in the mounts. Computational simulations of a simple and a multiple dimensional hybrid vibration isolation system are performed to study the force transmissibility and the total power flows from vibration sources through active and passive isolators to the supporting structures. The investigation focuses on the effects of a hybrid control approach to the reduction of power flow transmissions and the influence of the dynamic characteristics of the control on power flow spectra. The hybrid control mechanism is synthesised from the power flow analysis. Conclusions and control strategies, well supported by numerical simulations, are deduced providing very useful guidelines for hybrid vibration isolation design.

  16. The genetic architecture of reproductive isolation in Louisiana irises: hybrid fitness in nature.

    Science.gov (United States)

    Taylor, Sunni J; Arnold, Michael; Martin, Noland H

    2009-10-01

    Negative epistasis in hybrid genomes commonly results in postzygotic isolation between divergent lineages. However, some genomic regions may be selectively neutral or adaptive in hybrids and thus may potentially cross species barriers. We examined postzygotic isolation between ecologically similar species of Louisiana Iris: Iris brevicaulis and I. fulva to determine the potential for adaptive introgression in nature. Line-cross analyses allowed us a general overview of the gene action responsible for fitness-related traits. We then used a QTL mapping approach to detect genomic regions responsible for variation in these traits. Although hybrid classes suffered reduced fitness for many traits, hybrid means were equivalent to at least one of the parental species in overall estimates of maternal and paternal fitness during the two years of the field study. The genetic architecture underlying the fitness-related traits varied across field site and year of the study, thus emphasizing the importance of the environment in determining the degree of postzygotic isolation and potential for introgression across natural hybrid zones.

  17. Hybridization and reproductive isolation between diploid Erythronium mesochoreum and its tetraploid congener E. albidum (Liliaceae).

    Science.gov (United States)

    Roccaforte, Kathy; Russo, Sabrina E; Pilson, Diana

    2015-06-01

    Polyploidy has played an important role in angiosperm diversification, but how polyploidy contributes to reproductive isolation remains poorly understood. Most work has focused on postzygotic reproductive barriers, and the influence of ploidy differences on prezygotic barriers is understudied. To address these gaps, we quantified hybrid occurrence, interspecific self-compatibility differences, and the contributions of multiple pre- and postzygotic barriers to reproductive isolation between diploid Erythronium mesochoreum (Liliaceae) and its tetraploid congener Erythronium albidum. Reproductive isolation between the study species was nearly complete, and naturally occurring hybrids were infrequent and largely sterile. Although postzygotic barriers effected substantial reproductive isolation when considered in isolation, the study species' spatial distributions and pollinator assemblages overlapped little, such that interspecific pollen transfer is likely uncommon. We did not find evidence that E. albidum and E. mesochoreum differed in mating systems, indicating that self-incompatibility release may not have fostered speciation in this system. Ultimately, we demonstrate that E. albidum and E. mesochoreum are reproductively isolated by multiple, hierarchically-operating barriers, and we add to the currently limited number of studies demonstrating that early acting barriers such as pollinator-mediated isolation can be important for effecting and sustaining reproductive isolation in diploid-polyploid systems.

  18. Hybrid Electric Vehicle Power Management Solutions Based on Isolated and Non-Isolated Configurations of MMCCC Converter

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Faisal H [ORNL; Tolbert, Leon M [ORNL; Webb, William E [Oak Ridge National Laboratory (ORNL)

    2009-01-01

    This paper presents the various configurations of a multilevel modular capacitor-clamped converter (MMCCC), and it reveals many useful and new formations of the original MMCCC for transferring power in either an isolated or nonisolated manner. The various features of the original MMCCC circuit are best suited for a multibus system in future plug-in hybrid or fuel-cell-powered vehicles' drive train. The original MMCCC is capable of bidirectional power transfer using multilevel modular structure with capacitor-clamped topology. It has a nonisolated structure, and it offers very high efficiency even at partial loads. This circuit was modified to integrate single or multiple high-frequency transformers by using the intermediate voltage nodes of the converter. On the other hand, a special formation of the MMCCC can exhibit dc outputs offering limited isolation without using any isolation transformer. This modified version can produce a high conversion ratio from a limited number of components and has several useful applications in providing power to multiple low-voltage loads in a hybrid or electric automobile. This paper will investigate the origin of generating ac outputs from the MMCCC and shows how the transformer-free version can be modified to create limited isolation from the circuit. In addition, this paper will compare various modified forms of the MMCCC topology with existing dc-dc converter circuits from compactness and component utilization perspectives.

  19. Proposal of a seismic isolation structure for urban tunnels and the method to evaluate its isolation effects; Shield tunnel no menshin kozo to sono menshin koka no hyoka shuho no teian

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, T. [Kumagai Gumi Co. Ltd., Tokyo (Japan); Tamura, J. [Nihon Univ., Chiba (Japan). Coll. of Industrial Technology

    1995-10-21

    An earthquake damage of a shield-driven flannel occurred during the 1985 Michoacan earthquake in the central part of Mexico City. The damages were mainly originated from tunnel axial deformations, such as tension and torsion. In order to improve seismic safety of urban tunnels due to tunnel axial deformations during earthquakes, a seismic immolation structure, in which an isolation layer is formed between a tuner lining and its surrounding soil, is presented. This paper presents a simplified method to evaluate the isolation effect of the seismic isolation structure using axisymmetric finite element models. Through parametric studies using the models, the isolation effect is evaluated in terms of the axial and torsional strain seduction ratios. Furthermore, material properties to be needed as the isolation layer is determined from static stability analyses as well as dynamic analyses. As a result, the importance of high Poisson`s ratio of the layer material is proposed. 9 refs., 15 figs., 2 tabs.

  20. The nature of interactions that contribute to postzygotic reproductive isolation in hybrid copepods.

    Science.gov (United States)

    Willett, Christopher S

    2011-05-01

    Deleterious interactions within the genome of hybrids can lower fitness and result in postzygotic reproductive isolation. Understanding the genetic basis of these deleterious interactions, known as Dobzhansky-Muller incompatibilities, is the subject of intense current study that seeks to elucidate the nature of these deleterious interactions. Hybrids from crosses of individuals from genetically divergent populations of the intertidal copepod Tigriopus californicus provide a useful model in which to study Dobzhansky-Muller incompatibilities. Studies of the basis of postzygotic reproductive isolation in this species have revealed a number of patterns. First, there is evidence for a breakdown in genomic coadaptation between mtDNA-encoded and nuclear-encoded proteins that can result in a reduction in hybrid fitness in some crosses. It appears from studies of the individual genes involved in these interactions that although this coadaptation could lead to asymmetries between crosses, patterns of genotypic viabilities are not often consistent with simple models of genomic coadaptation. Second, there is a large impact of environmental factors on these deleterious interactions suggesting that they are not strictly intrinsic in nature. Temperature in particular appears to play an important role in determining the nature of these interactions. Finally, deleterious interactions in these hybrid copepods appear to be complex in terms of the number of genetic factors that interact to lead to reductions in hybrid fitness. This complexity may stem from three or more factors that all interact to cause a single incompatibility or the same factor interacting with multiple other factors independently leading to multiple incompatibilities.

  1. Genetic diversity of Streptococcus suis isolates as determined by comparative genome hybridization

    Directory of Open Access Journals (Sweden)

    Thi Hoa

    2011-07-01

    Full Text Available Abstract Background Streptococcus suis is a zoonotic pathogen that causes infections in young piglets. S. suis is a heterogeneous species. Thirty-three different capsular serotypes have been described, that differ in virulence between as well as within serotypes. Results In this study, the correlation between gene content, serotype, phenotype and virulence among 55 S. suis strains was studied using Comparative Genome Hybridization (CGH. Clustering of CGH data divided S. suis isolates into two clusters, A and B. Cluster A isolates could be discriminated from cluster B isolates based on the protein expression of extracellular factor (EF. Cluster A contained serotype 1 and 2 isolates that were correlated with virulence. Cluster B mainly contained serotype 7 and 9 isolates. Genetic similarity was observed between serotype 7 and serotype 2 isolates that do not express muramidase released protein (MRP and EF (MRP-EF-, suggesting these isolates originated from a common founder. Profiles of 25 putative virulence-associated genes of S. suis were determined among the 55 isolates. Presence of all 25 genes was shown for cluster A isolates, whereas cluster B isolates lacked one or more putative virulence genes. Divergence of S. suis isolates was further studied based on the presence of 39 regions of difference. Conservation of genes was evaluated by the definition of a core genome that contained 78% of all ORFs in P1/7. Conclusions In conclusion, we show that CGH is a valuable method to study distribution of genes or gene clusters among isolates in detail, yielding information on genetic similarity, and virulence traits of S. suis isolates.

  2. Fast 3d Hybrid Seismic Modeling: Ray-fd Approach For Elastic Models With Locally Complex Structures

    Science.gov (United States)

    Oprsal, I.; Brokesova, J.; Faeh, D.; Giardini, D.

    Hybrid approaches may find broad applications wherever full source, path,and site effects modeling methods are too expensive. A new efficient hybrid method allowing to compute seismic wavefield in large 3D elastic models containing a complex local structure embedded in a large, but considerably simpler, structure is designed. This hybrid method combines the ray approach in the large simple structure with the finite difference (FD) approach in the local complex structure. The hybrid method is based on two successive steps. In the 1st one, the source and path information is carried by wavefield propagating in the large simple structure. This wavefield, calculated by the ray method, is incident at the points along a two-fold formal boundary (excitation box, EB) surrounding that part of the model which is to be replaced by the complex medium in the 2nd step. 3D rays are necessary due to ar- bitrary source-EB configuration, even in case the 1st step structure is less dimensional (2D, 1D, homogeneous). Along EB, the ray endpoints may be distributed sparsely thanks to relative simplicity of the structure. This reduces computer time requirements and also the size of the excitation file saved on the disk. The ray wavefield along EB provides (after interpolation in space and time) the input for the second step consisting in calculating the complete wavefield by the 3D FD method on irregular grids. The FD computational domain contains the EB and its close vicinity. The 2nd step model differs from the 1st step model only inside the EB where the local complex structure is inserted. To verify the consistency between the 1st and the 2nd step binding, the 2nd step computation can be performed on (unchanged) 1st step model ('replication test'). This should give the same wavefield as the 1st step inside, and zero wavefield outside the EB. The EB remains fully permeable for all waves propagating within the FD domain. Provided the 1st step structure does not contain too many layers

  3. Method for isolating chromosomal DNA in preparation for hybridization in suspension

    Science.gov (United States)

    Lucas, Joe N.

    2000-01-01

    A method is provided for detecting nucleic acid sequence aberrations using two immobilization steps. According to the method, a nucleic acid sequence aberration is detected by detecting nucleic acid sequences having both a first nucleic acid sequence type (e.g., from a first chromosome) and a second nucleic acid sequence type (e.g., from a second chromosome), the presence of the first and the second nucleic acid sequence type on the same nucleic acid sequence indicating the presence of a nucleic acid sequence aberration. In the method, immobilization of a first hybridization probe is used to isolate a first set of nucleic acids in the sample which contain the first nucleic acid sequence type. Immobilization of a second hybridization probe is then used to isolate a second set of nucleic acids from within the first set of nucleic acids which contain the second nucleic acid sequence type. The second set of nucleic acids are then detected, their presence indicating the presence of a nucleic acid sequence aberration. Chromosomal DNA in a sample containing cell debris is prepared for hybridization in suspension by treating the mixture with RNase. The treated DNA can also be fixed prior to hybridization.

  4. Parental frequencies and spatial configuration shape bumblebee behavior and floral isolation in hybridizing Rhinanthus.

    Science.gov (United States)

    Natalis, Laurent C; Wesselingh, Renate A

    2013-06-01

    To shed light on the role played by pollinators in the diversification of angiosperms, focus is needed on how floral isolation varies locally in the early stages of plant divergence. The few studies performed so far have often used species pairs with distinct pollination syndromes and contrasting floral displays. Here, we focus on a hybridizing pair (Rhinanthus minor and Rhinanthus angustifolius) with strong similarities in flower morphology and pollinators (bumblebees). We examined how ethological isolation changes locally in relation to relative Rhinanthus frequencies, spatial configurations, and pollinator assemblages. Interestingly, floral divergence based on adaptation to different pollinators is unlikely in Rhinanthus: no relationship was found between floral isolation and the local pollinator assemblage. In contrast, species frequency and spatial arrangement strongly influenced bumblebee behavior, ethological isolation, and thus potentially hybrid formation. When both Rhinanthus were present in equal proportions, bees generally preferred the more rewarding and conspicuous species. However, when the Rhinanthus frequencies were unbalanced, the more abundant species was preferred, although this was less pronounced when the less rewarding R. minor predominated. Ethological isolation is highly sensitive to site characteristics, and can be as high as in species with contrasting floral displays and pollinator suites, even though flowers are similar. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  5. Imaging Geological Structures Up to the Acquisition Surface Using a Hybrid Refraction-Reflection Seismic Method

    Directory of Open Access Journals (Sweden)

    Mendes M.

    2013-08-01

    Full Text Available The aim of seismic imaging is to reconstruct the reflectivity associated with subsurface structures. In standard imaging techniques, the reflectivity model usually starts a few meters below the surface, the actual depth being dependent on data acquisition parameters and the mute used to remove stretching of first arrivals after normal moveout correction. In this paper, we describe a method to image the reflectivity of near-surface structures starting from the acquisition surface. This is achieved by processing both the first arrivals and the reflected phases present in data collected for refraction surveys. The proposed imaging procedure works in three steps. First, we obtain a velocity model for the shallow region by combining the Plus-Minus method of refraction interpretation with tomographic inversion of first arrival times. Second, by processing reflection events present in the refraction data, we obtain a standard reflectivity section for the deeper region. Finally, we compute reflectivity for the shallow region using the velocity model estimated from first arrival information in step 1. This velocity model is used both to compute reflectivity and to convert it in time. The reflectivity obtained for the shallow region is associated with velocity contrasts. In order to merge it with the reflectivity section for the deeper region a scaling factor between the two sets of reflectivity sections must be computed and applied. The novelty of this contribution is the use the tomographic velocity model in evaluating reflectivity for the upper part of the section. This improves the continuity of information about all near-surface structures in comparison with previous works that were limited to reflection data. Three field examples illustrate the proposed procedure showing continuous information about reflectivity of structures starting from the acquisition surface.

  6. Genetic architecture of hybrid male sterility in Drosophila: analysis of intraspecies variation for interspecies isolation.

    Directory of Open Access Journals (Sweden)

    Laura K Reed

    Full Text Available BACKGROUND: The genetic basis of postzygotic isolation is a central puzzle in evolutionary biology. Evolutionary forces causing hybrid sterility or inviability act on the responsible genes while they still are polymorphic, thus we have to study these traits as they arise, before isolation is complete. METHODOLOGY/PRINCIPAL FINDINGS: Isofemale strains of D. mojavensis vary significantly in their production of sterile F(1 sons when females are crossed to D. arizonae males. We took advantage of the intraspecific polymorphism, in a novel design, to perform quantitative trait locus (QTL mapping analyses directly on F(1 hybrid male sterility itself. We found that the genetic architecture of the polymorphism for hybrid male sterility (HMS in the F(1 is complex, involving multiple QTL, epistasis, and cytoplasmic effects. CONCLUSIONS/SIGNIFICANCE: The role of extensive intraspecific polymorphism, multiple QTL, and epistatic interactions in HMS in this young species pair shows that HMS is arising as a complex trait in this system. Directional selection alone would be unlikely to maintain polymorphism at multiple loci, thus we hypothesize that directional selection is unlikely to be the only evolutionary force influencing postzygotic isolation.

  7. Isolation of plant transcription factors using a modified yeast one-hybrid system

    Directory of Open Access Journals (Sweden)

    Shirley Neil

    2006-02-01

    Full Text Available Abstract Background The preparation of expressional cDNA libraries for use in the yeast two-hybrid system is quick and efficient when using the dedicated Clontech™ product, the MATCHMAKER Library Construction and Screening Kit 3. This kit employs SMART technology for the amplification of full-length cDNAs, in combination with cloning using homologous recombination. Unfortunately, such cDNA libraries prepared directly in yeast can not be used for the efficient recovery of purified plasmids and thus are incompatible with existing yeast one-hybrid systems, which use yeast transformation for the library screen. Results Here we propose an adaptation of the yeast one-hybrid system for identification and cloning of transcription factors using a MATCHMAKER cDNA library. The procedure is demonstrated using a cDNA library prepared from the liquid part of the multinucleate coenocyte of wheat endosperm. The method is a modification of a standard one-hybrid screening protocol, utilising a mating step to introduce the library construct and reporter construct into the same cell. Several novel full length transcription factors from the homeodomain, AP2 domain and E2F families of transcription factors were identified and isolated. Conclusion In this paper we propose a method to extend the compatibility of MATCHMAKER cDNA libraries from yeast two-hybrid screens to one-hybrid screens. The utility of the new yeast one-hybrid technology is demonstrated by the successful cloning from wheat of full-length cDNAs encoding several transcription factors from three different families.

  8. Seismic vulnerability assessment of a steel-girder highway bridge equipped with different SMA wire-based smart elastomeric isolators

    Science.gov (United States)

    Hedayati Dezfuli, Farshad; Shahria Alam, M.

    2016-07-01

    Shape memory alloy wire-based rubber bearings (SMA-RBs) possess enhanced energy dissipation capacity and self-centering property compared to conventional RBs. The performance of different types of SMA-RBs with different wire configurations has been studied in detail. However, their reliability in isolating structures has not been thoroughly investigated. The objective of this study is to analytically explore the effect of SMA-RBs on the seismic fragility of a highway bridge. Steel-reinforced elastomeric isolators are equipped with SMA wires and used to isolate the bridge. Results revealed that SMA wires with a superelastic behavior and re-centering capability can increase the reliability of the bearing and the bridge structure. It was observed that at the collapse level of damage, the bridge isolated by SMA-HDRB has the lowest fragility. Findings also showed that equipping NRB with SMA wires decreases the possibility of damage in the bridge while, replacing HDRB with SMA-HDRB; or LRB with SMA-LRB increases the failure probability of the system at slight, moderate, and extensive limit states.

  9. Evaluation of seismic acceleration responses of base-isolated and nonisolated structures varying with mechanical characteristics of foundations

    Energy Technology Data Exchange (ETDEWEB)

    You, Bong; Lee, Jae Han; Ku, Kyung Hoi [Korea Atomic Energy Research Institute, Daeduk (Korea, Republic of)

    1996-05-01

    The evaluation of acceleration responses of isolated and nonisolated structures according to mechanical features of soils is important. The kinds of soils taken in analyses are soft, medium and hard rocks, and a fixed base condition is also taken for the comparison. The horizontal isolation frequency used is 0.5 Hz. The time history analyses of reference power plant using 1940 El Centro horizontal (NS) and vertical earthquakes are performed to investigate the seismic responses varying with soil characteristics for isolated and nonisolated structures. The horizontal acceleration responses of the horizontal isolated-structures show almost similar values irrespective of the various kinds of soils and are largely decreased in the frequency ranges above 2 hz. The vertical natural frequency, 21Hz of high damping rubber bearing does not affect the vertical acceleration responses in case of soft rock, but largely affects in hard rock condition. For nonisolated structures, the acceleration responses are decreased in both horizontal and vertical directions by taking into account the soils in the analysis model. The extent of reduction of acceleration responses is larger in vertical direction than in horizontal one, as the stiffness of rock becomes softer. 8 tabs., 21 figs., 8 refs. (Author) .new.

  10. Experimental studies of the seismic response of structures incorporating base-isolation systems

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, J.M.; Aiken, I.D. (University of California, Berkeley, CA (USA))

    1991-06-01

    This paper reviews some of the achievements of the Earthquake Engineering Research Center (EERC) at the University of California at Berkeley in the last few years. Component tests on single isolators are described. Tests on plain and high-damping natural-rubber bearings, lead-rubber bearings, sliding bearings, and bearings incorporating uplift resistance mechanisms have been performed. High-shear strain tests on large (up to full scale) elastomeric bearings have been conducted to determine the stability characteristics and limit states of the isolators. Performance evaluation studies using the earthquake simulator to test large-scale model isolated structures have been carried out for a variety of isolation systems and structures. Uplift studies of slender base-isolated buildings and investigation of the behavior of base-isolated skew bridge decks have been studied. This paper aims to highlight those areas where progress has been made. (orig./HP).

  11. Comparative genomics among Saccharomyces cerevisiae × Saccharomyces kudriavzevii natural hybrid strains isolated from wine and beer reveals different origins

    Science.gov (United States)

    2012-01-01

    Background Interspecific hybrids between S. cerevisiae × S. kudriavzevii have frequently been detected in wine and beer fermentations. Significant physiological differences among parental and hybrid strains under different stress conditions have been evidenced. In this study, we used comparative genome hybridization analysis to evaluate the genome composition of different S. cerevisiae × S. kudriavzevii natural hybrids isolated from wine and beer fermentations to infer their evolutionary origins and to figure out the potential role of common S. kudriavzevii gene fraction present in these hybrids. Results Comparative genomic hybridization (CGH) and ploidy analyses carried out in this study confirmed the presence of individual and differential chromosomal composition patterns for most S. cerevisiae × S. kudriavzevii hybrids from beer and wine. All hybrids share a common set of depleted S. cerevisiae genes, which also are depleted or absent in the wine strains studied so far, and the presence a common set of S. kudriavzevii genes, which may be associated with their capability to grow at low temperatures. Finally, a maximum parsimony analysis of chromosomal rearrangement events, occurred in the hybrid genomes, indicated the presence of two main groups of wine hybrids and different divergent lineages of brewing strains. Conclusion Our data suggest that wine and beer S. cerevisiae × S. kudriavzevii hybrids have been originated by different rare-mating events involving a diploid wine S. cerevisiae and a haploid or diploid European S. kudriavzevii strains. Hybrids maintain several S. kudriavzevii genes involved in cold adaptation as well as those related to S. kudriavzevii mitochondrial functions. PMID:22906207

  12. Seismic Response of a Deep Underground Geologic Repository for Nuclear Waste at the Waste Isolation Pilot Plant in New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, P.E.

    1998-11-02

    The Waste Isolation Pilot Plant (WIPP) is a deep underground nuclear waste repository certified by the U.S. Environmental Protection Agency ,(EPA) to store transuranic defense-related waste contaminated by small amounts of radioactive materials. Located at a depth of about 655 meters below the surface, the facility is sited in southeastern New Mexico, about 40 Department of Energy underground facilities, waste disposal. kilometers east of the city of Carlsbad, New Mexico. The U.S. (DOE) managed the design and construction of the surface and and remains responsible for operation and closure following The managing and operating contractor for the DOE at the WIPP, Westinghouse Electric Corporation, maintains two rechmiant seismic monitoring systems located at the surface and in the underground. This report discusses two earthquakes detected by the seismic monitoring system, one a duratior magnitude 5.0 (Md) event located approximately 60 km east-southeast of the facility, and another a body-wave magnitude 5.6 (rob) event that occurred approximately 260 kilometers to the south-southeast.

  13. Stationary levitation and vibration transmission characteristic in a superconducting seismic isolation device with a permanent magnet system and a copper plate

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, S., E-mail: s.sasaki@ecei.tohoku.ac.j [Electrical Engineering Department, Graduate School, Tohoku University, 6-6-05 Aoba Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Shimada, K.; Yagai, T.; Tsuda, M.; Hamajima, T. [Electrical Engineering Department, Graduate School, Tohoku University, 6-6-05 Aoba Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Kawai, N.; Yasui, K. [Okumura Corporation, 5-6-1 Shiba, Minato-ku, Tokyo 180-8381 (Japan)

    2010-11-01

    We have devised a magnetic levitation type superconducting seismic isolation device taking advantage of the specific characteristic of HTS bulk that the HTS bulk returns to its original position by restoring force against a horizontal displacement. The superconducting seismic isolation device is composed of HTS bulks and permanent magnets (PM rails). The PMs are fixed on an iron plate to realize the same polarities in the longitudinal direction and the different polarities in the transverse direction. The superconducting seismic isolation device can theoretically remove any horizontal vibrations completely. Therefore, the vibration transmissibility in the longitudinal direction of the PM rail becomes zero in theory. The zero vibration transmissibility and the stationary levitation, however, cannot be achieved in the real device because a uniform magnetic field distribution in the longitudinal direction of PM rail cannot be realized due to the individual difference of the PMs. Therefore, to achieve stationary levitation in the real device we adopted a PM-PM system that the different polarities are faced each other. The stationary levitation could be achieved by the magnetic interaction between the PMs in the PM-PM system, while the vibration transmitted to the seismic isolation object due to the magnetic interaction. We adopted a copper plate between the PMs to reduce the vibration transmissibility. The PM-PM system with the copper plate is very useful for realizing the stationary levitation and reducing the vibration transmissibility.

  14. Physicochemical studies on starches isolated from plantain cultivars, plantain hybrids and cooking bananas

    Energy Technology Data Exchange (ETDEWEB)

    Eggleston, G.; Akoni, S. (International Inst. of Tropical Agriculture, Ibadan (Nigeria)); Swennen, R. (Catholic Univ. of Leuven, Heverlee (Belgium). Lab. of Tropical Husbandry)

    1992-04-01

    Starches from mature, unripe fruit pulp of plantain cultivars (Musa supp., AAB group) representing the wide variability in Africa, tetraploid and diploid plantain hybrids and starchy cooking bananas (Musa spp., ABB group) were isolated and characterised. In general, studies revealed very compact irregularly shaped and sized granules, with low amylose content (9.11-17.16%), highly resistant to bacterial {alpha}-amylase attack; Brabender amylograms showed very restricted swelling type patterns with great stability and negligible retrogradation. Results indicate that differences in physico-chemical properties exist amongst the three Musa fruit group starches. Plantains represent a chemical/molecular homogeneous group, but heterogeneous for granule structure. Ploidy level affected hybrid properties. ABB cooking bananas starches exhibited highly pronounced restricted swelling and high gelatinisation and pasting temperatures, indicating a more ordered, very strongly bonded granule structure; chemical and physical properties varied considerably within the ABB genotype. (orig.).

  15. Seismic Response of Base-Isolated Structures under Multi-component Ground Motion Excitation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An analysis of a base-isolated structure for multi-component random ground motion is presented. The mean square response of the system is obtained under different parametric variations. The effectiveness of main parameters and the torsional component during an earthquake is quantified with the help of the response ratio and the root mean square response with and without base isolation. It is observed that the base isolation has considerable influence on the response and the effect of the torsional component is not ignored.

  16. Analysis of seismic noise to check the mechanical isolation of a medical device

    Directory of Open Access Journals (Sweden)

    Sara Rombetto

    2011-07-01

    Full Text Available We have investigated the mechanical response of a magnetically shielded room that hosts a magnetoencephalography system that is subject to external vibrations. This is a superconducting quantum interference device, which are the most sensitive sensors for magnetic flux variations. When the magnetoencephalography operates with people inside the room, the spectrum of the flux of the magnetic field shows anomalous peaks at several frequencies between 1 Hz and 20 Hz, independent of the experiment that is being run. As the variations in the flux of the magnetic field through the sensors might not only be related to the electrical currents circulating inside the brain, but also to non-damped mechanical oscillations of the room, we installed seismic instrumentation to measure the effective motion inside the room and to compare it to the external motion. For this analysis, we recorded the ambient seismic noise at two very close stations, one inside the magnetically shielded room, the other one outside in the room in which the magnetically shielded room is itself located. Data were collected over four days, including a week-end, to study the response of the magnetically shielded room subjected to different energy levels of external vibrations. The root mean square, Fourier spectra and power spectral density show significant differences between the signal recorded inside and outside the magnetically shielded room, with several anomalous peaks in the frequency band of 1 Hz to 20 Hz. The normalized spectral quantities (horizontal to vertical spectral ratio, and ratio between the internal and external spectra show large amplification at several frequencies, reaching in some cases one order of magnitude. We concluded that the magnetically shielded room does not dampen the external vibrations, but it instead appears to amplify these across a broad frequency range.

  17. A generic plant RNA isolation method suitable for RNA-Seq and suppression subtractive hybridization.

    Science.gov (United States)

    Zhu, Y Q; Wu, W J; Xiao, H W; Chen, H B; Zheng, Y; Zhang, Y J; Wang, H X; Huang, L Q

    2013-11-18

    A recently developed revolutionary approach to transcriptomics, RNA-Seq, and suppression subtractive hybridization are powerful tools for gene expression research. However, currently, the difficulty of isolating high-quality RNAs from plant tissues bearing abundant complex polysaccharides, polyphenolics, and secondary metabolites is a serious problem that not only limits the application of these technologies but also hinders studies dealing with RNA in general. We have developed a consistent protocol to prepare highly intact and pure RNAs from tissues of a variety of field-grown plant species, with high yields, in 2 to 3 h. Additionally, this method can be readily applied to mammalian, yeast, and bacterial cells.

  18. Genotypic Resistance of F1 Cotton Hybrids by Inoculation with Different Virulent Isolates of the Fungus Verticillium Dahliae Klebahn

    Institute of Scientific and Technical Information of China (English)

    AMANTURDIEV Alisher; KIM Robert

    2008-01-01

    @@ The plant pathogen Verticilliurn dahliae causes severe cotton losses in Uzbekistan.To create cotton varieties that are resistant to the more virulent races of V.dahliae we wanted to determine genotypic resistance of varieties and lines of cotton to more virulent isolates of different geographic populations of the fungus V.dahliae isolated from different cotton varieties in Uzbekistan and determine the inheritance of wilt resistance with hybrids of the first generation to various isolates of V.dahliae.

  19. Evaluation of Seismic Performance of Long Span Continuous Girder Bridges Based on Seismic Isolation Design%基于减隔震设计的大跨度连续梁桥抗震性能评价

    Institute of Scientific and Technical Information of China (English)

    李贞新; 刘高

    2011-01-01

    Nonlinear time history analysis method is adopted to analyze dynamic characteristics and seismic performance based on long span continuous girder bridges with spans of 89 m, 170 m and 89 m in high intensity region. The good hysteretic, energy-dissipation characteristics and self-restoring ability of double curvature seismic isolation bearings are simulated as well as the friction energy-dissipation characteristics of sliding bearing and damping energy-dissipation characteristics of dampers. Analytical results indicate that seismic performance can basically meet the expected design goal; seismic isolation device of double curvature spherical supports and dampers can adjust dynamic characteristics, reduce seismic response, dissipate earthquake energy and guarantee the safety of the structure.%基于高烈度区的某大跨度连续梁桥(89 m+170 m+89 m),采用非线性时程分析法进行结构动力特性及抗震性能分析.全桥均采用三维梁单元建立空间模型,对于双曲面球形减隔震支座的滞回耗能特性和自恢复功能,活动支座的摩擦耗能以及固定销剪断后的效应进行了模拟,同时模拟了阻尼器的阻尼耗能作用.研究结果表明:采用双曲面球形减隔震支座及桥台处纵向阻尼器后,结构的反应得到了很好的控制,确保了高烈度区结构的抗震安全性.

  20. Automatic generation of smart earthquake-resistant building system: Hybrid system of base-isolation and building-connection.

    Science.gov (United States)

    Kasagi, M; Fujita, K; Tsuji, M; Takewaki, I

    2016-02-01

    A base-isolated building may sometimes exhibit an undesirable large response to a long-duration, long-period earthquake ground motion and a connected building system without base-isolation may show a large response to a near-fault (rather high-frequency) earthquake ground motion. To overcome both deficiencies, a new hybrid control system of base-isolation and building-connection is proposed and investigated. In this new hybrid building system, a base-isolated building is connected to a stiffer free wall with oil dampers. It has been demonstrated in a preliminary research that the proposed hybrid system is effective both for near-fault (rather high-frequency) and long-duration, long-period earthquake ground motions and has sufficient redundancy and robustness for a broad range of earthquake ground motions.An automatic generation algorithm of this kind of smart structures of base-isolation and building-connection hybrid systems is presented in this paper. It is shown that, while the proposed algorithm does not work well in a building without the connecting-damper system, it works well in the proposed smart hybrid system with the connecting damper system.

  1. Automatic generation of smart earthquake-resistant building system: Hybrid system of base-isolation and building-connection

    Directory of Open Access Journals (Sweden)

    M. Kasagi

    2016-02-01

    Full Text Available A base-isolated building may sometimes exhibit an undesirable large response to a long-duration, long-period earthquake ground motion and a connected building system without base-isolation may show a large response to a near-fault (rather high-frequency earthquake ground motion. To overcome both deficiencies, a new hybrid control system of base-isolation and building-connection is proposed and investigated. In this new hybrid building system, a base-isolated building is connected to a stiffer free wall with oil dampers. It has been demonstrated in a preliminary research that the proposed hybrid system is effective both for near-fault (rather high-frequency and long-duration, long-period earthquake ground motions and has sufficient redundancy and robustness for a broad range of earthquake ground motions.An automatic generation algorithm of this kind of smart structures of base-isolation and building-connection hybrid systems is presented in this paper. It is shown that, while the proposed algorithm does not work well in a building without the connecting-damper system, it works well in the proposed smart hybrid system with the connecting damper system.

  2. Cost based reactive power participation for voltage control in multi units based isolated hybrid power system

    Directory of Open Access Journals (Sweden)

    Nitin Kumar Saxena

    2016-12-01

    Full Text Available Multi units of wind and diesel based generators in isolated hybrid power system have technical and operational advantages over single units system. They require dynamic reactive power compensation for fast recovery of voltage under load and input changes. In developing countries like India, investors’ prime concern is to provide continuous electricity at low rate while quality degradation can be permitted within pre defined acceptable range. The use of static compensator along with dynamic compensator may give cost effective reactive power participation for system. This paper presented pricing of reactive power compensation under steady state and transient conditions of system with fixed capacitor and STATCOM. The main contributions of the paper are; (i evaluating reactive power balance equation for generalized multi units of wind and diesel based isolated hybrid power system, (ii reactive power compensation using fixed capacitor and STATCOM in presence of composite load model, (ii fast recovery of voltage response using genetic algorithm based tuning of STATCOM controller, (iii evaluation of reactive power compensation cost for steady and dynamic conditions due to probabilistic change in load and/or input demand and (iv comparison of results with existing reference compensation method.

  3. Mycoflora and aflatoxin/fumonisin production by fungal isolates from freshly harvested corn hybrids

    Directory of Open Access Journals (Sweden)

    Almeida Adriana P.

    2000-01-01

    Full Text Available The mycoflora of 3 hybrids of freshly harvested corn grains collected from three regions of the state of São Paulo, Brazil (Assis, Capão Bonito and Ribeirão Preto was investigated. A total of 66 samples were analyzed focusing on the influence of abiotic factors (moisture content, water activity, temperature and rainfall on both the prevalence of Aspergillus flavus and Fusarium moniliforme, and the ability of these genera isolates to produce aflatoxins and fumonisins, respectively. In the three surveyed regions, the fungal population comprised mainly Fusarium spp., Penicillium spp., Aspergillus spp. and 2 others filamentous fungal genera, which were isolated from corn kernels showing water activity of 0.30 to 0.99 and moisture content of 5.0% to 20.2%. Among the genera Fusarium and Aspergillus, the most frequent species were F. moniliforme and A. flavus, respectively. Concerning the toxigenic potential of F. moniliforme, all isolated strains (40 produced fumonisins at 20 mug/g to 2168 mug/g (FB1 and/or 10 mug/g to 380 mug/g (FB2. From the 10 A. flavus isolates, 6 strains (60.0% produced aflatoxins at 615 mug/kg to 30.750 mug/kg (AFB1 and/or 11 mug/kg to 22 mug/kg (AFB2.

  4. Seismic Vibration Control of Elevated Water Tank by TLD and Validation of Full-Scale TLD Model through Real-Time-Hybrid-Testing

    Science.gov (United States)

    Roy, A.; Staino, A.; (D Ghosh, A.; Basu, B.; Chatterjee, S.

    2016-09-01

    Elevated water tanks (EWTs), being top-heavy structures, are highly vulnerable to earthquake forces, and several have experienced damage/failure in past seismic events. However, as these are critical facilities whose continued performance in the post-earthquake scenario is of vital concern, it is significant to investigate their seismic vibration control using reliable and cost-effective passive dampers such as the Tuned Liquid Damper (TLD). Here, this aspect is studied for flexible EWT structures, such as those with annular shaft supports. The criterion of tuning the sloshing frequency of the TLD to the structural frequency necessitates dimensions of the TLD larger than those hitherto examined in literature. Hence the nonlinear model of the TLD based on established shallow water wave theory is verified for large container size by employing Real-Time-Hybrid-Testing (RTHT). Simulation studies are further carried out on a realistic example of a flexible EWT structure with TLDs. Results indicate that the TLD can be applied very effectively for the seismic vibration mitigation of EWTs.

  5. Seismic response characteristics of full-size buildings with base isolation system

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C.Y.; Gvildys, J.

    1991-01-01

    This paper investigates the response characteristics of full-size reinforced concrete buildings via numerical simulations and actual observations. The test facility consists of two identical three-story buildings constructed side by side at Tohoku University in Sendai, Japan. Since the installation of high-damping isolation bearings in April 1989, data from over twenty earthquakes have been recorded. In this paper, three representative earthquake records, No. 2, No. 6, and No. 17 are used to study the detailed response characteristics. Numerical simulations are carried out with the system response program, SISEC. In general, good agreement has been found between numerical solutions and actual observations. The system is stiff enough to prevent the building displacement under minor earthquakes and wind loads, but is relatively soft for reducing the acceleration response during earthquakes with moderate and strong ground motion. Lessons learned in this effort are applicable to base isolation design of nuclear power plants. 7 refs., 16 figs., 3 tabs.

  6. Two novel EHEC/EAEC hybrid strains isolated from human infections.

    Directory of Open Access Journals (Sweden)

    Rita Prager

    Full Text Available The so far highest number of life-threatening hemolytic uremic syndrome was associated with a food-borne outbreak in 2011 in Germany which was caused by an enterohemorrhagic Escherichia coli (EHEC of the rare serotype O104:H4. Most importantly, the outbreak strain harbored genes characteristic of both EHEC and enteroaggregative E. coli (EAEC. Such strains have been described seldom but due to the combination of virulence genes show a high pathogenicity potential. To evaluate the importance of EHEC/EAEC hybrid strains in human disease, we analyzed the EHEC strain collection of the German National Reference Centre for Salmonella and other Bacterial Enteric Pathogens (NRC. After exclusion of O104:H4 EHEC/EAEC strains, out of about 2400 EHEC strains sent to NRC between 2008 and 2012, two strains exhibited both EHEC and EAEC marker genes, specifically were stx2 and aatA positive. Like the 2011 outbreak strain, one of the novel EHEC/EAEC harbored the Shiga toxin gene type stx2a. The strain was isolated from a patient with bloody diarrhea in 2010, was serotyped as O59:H-, belonged to MLST ST1136, and exhibited genes for type IV aggregative adherence fimbriae (AAF. The second strain was isolated from a patient with diarrhea in 2012, harbored stx2b, was typed as Orough:H-, and belonged to MLST ST26. Although the strain conferred the aggregative adherence phenotype, no known AAF genes corresponding to fimbrial types I to V were detected. In summary, EHEC/EAEC hybrid strains are currently rarely isolated from human disease cases in Germany and two novel EHEC/EAEC of rare serovars/MLST sequence types were characterized.

  7. Comparative genomics among Saccharomyces cerevisiae × Saccharomyces kudriavzevii natural hybrid strains isolated from wine and beer reveals different origins

    Directory of Open Access Journals (Sweden)

    Peris David

    2012-08-01

    Full Text Available Abstract Background Interspecific hybrids between S. cerevisiae × S. kudriavzevii have frequently been detected in wine and beer fermentations. Significant physiological differences among parental and hybrid strains under different stress conditions have been evidenced. In this study, we used comparative genome hybridization analysis to evaluate the genome composition of different S. cerevisiae × S. kudriavzevii natural hybrids isolated from wine and beer fermentations to infer their evolutionary origins and to figure out the potential role of common S. kudriavzevii gene fraction present in these hybrids. Results Comparative genomic hybridization (CGH and ploidy analyses carried out in this study confirmed the presence of individual and differential chromosomal composition patterns for most S. cerevisiae × S. kudriavzevii hybrids from beer and wine. All hybrids share a common set of depleted S. cerevisiae genes, which also are depleted or absent in the wine strains studied so far, and the presence a common set of S. kudriavzevii genes, which may be associated with their capability to grow at low temperatures. Finally, a maximum parsimony analysis of chromosomal rearrangement events, occurred in the hybrid genomes, indicated the presence of two main groups of wine hybrids and different divergent lineages of brewing strains. Conclusion Our data suggest that wine and beer S. cerevisiae × S. kudriavzevii hybrids have been originated by different rare-mating events involving a diploid wine S. cerevisiae and a haploid or diploid European S. kudriavzevii strains. Hybrids maintain several S. kudriavzevii genes involved in cold adaptation as well as those related to S. kudriavzevii mitochondrial functions.

  8. Experimental Study on the Force-Bearing Performance of Masonry Structures with a Marble-Graphite Slide Seismic Isolator at the Foundation

    Directory of Open Access Journals (Sweden)

    Suizi Jia

    2016-11-01

    Full Text Available As part of the search for a seismic isolator for low-rise buildings, this paper proposes a marble-graphite slide seismic isolation system composed of marble-graphite slides, an upper foundation beam, the lower counterpart of the upper beam, and the corresponding stop blocks, with the stop blocks consisting of restrictive screws, positioning plates, nut connectors and stop holes linking the two foundation beams. To provide the desired isolation performance, plain mortar bars can be included at the beam interface to better control the initiating loads for foundation slippage. Tests of low-reversed cyclic loading were performed on four different masonry specimens: a recycled brick wall, a clay brick wall, an integrated recycled brick wall with flay ash blocks sandwiched between, and its clay brick counterpart. The four specimens were provided with marble-graphite slide isolators placed at the foundations. The isolator thickness was 20 mm, and the graphite and the marble served as a lubricant and a bearing, respectively. This paper then analyses all of the specimens in terms of the damage that occurred, the initiating load for slippage, the hysteretic performance, the bearing capacity and the performance of the stop blocks. The results indicate that mortar bars embedded in the marble-graphite slide isolator offer effective control of the initiating load, and the isolation system delivers good hysteretic performance. The stop blocks are capable of withstanding a large-magnitude earthquake and are a good choice for constraining the slippage displacement. Damage or failure of the specimens occurs only when the low-reversed cyclic loading continues after slippage takes place. The design is shown to be an outstanding and flexible seismic scheme for use in low-rise buildings.

  9. On the Nature of Scattering from Isolated Perturbations in Elastic Media and the Consequences for Processing of Seismic Data

    OpenAIRE

    Müller, Christof

    2000-01-01

    The nature of seismic scattering was investigated by elastic scattering theory and numerical experiment. Seismic scattering situations can be classified by analyzing the amplitude versus scattering angle behavior of the scattered seismic wave field. The shape of large objects has significant impact on the dynamics of the scattered wave field. Gather oriented as well as prestack methods capable of enhancing the scattering response and assisting in classification were developed. A new 3D migrat...

  10. A time domain system identification for nonlinear behaviors of a seismic isolator using the secant stiffness model

    Energy Technology Data Exchange (ETDEWEB)

    Park, H. W.; Jeon, Y. S. [KAERI, Taejon (Korea, Republic of)

    2002-10-01

    Nonlinear hysteretic behaviors and stiffness changes of a seismic isolator are identified by using a Time Domain System Identification (TDSI) based on the secant stiffness model. A new regularity condition of tangent stiffness used in the current TDSI is proposed instead of that used in the conventional Duhem hysteretic operator. The proposed regularity condition is defined with respect to time while that of Duhem hysteretic operator is defined with respect to displacements and restoring forces. The secant stiffness model for the TDSI is obtained by approximating the tangent stiffness under the proposed regularity condition by the secant stiffness at each time step. A least square method is employed to minimize the difference between the calculated response and measured response for the time domain system identification of the secant stiffness. The regularity condition of the secant stiffness is utilized to alleviate ill-posedness of the TDSI and to yield physically meaningful solutions by means of the regularization technique. An optimal regularization factor determined by Geometric Mean Scheme (GMS) is adopted to yield appropriate regularization effects on the system identification. The validity of the proposed method is presented through two numerical examples.

  11. Development of a three-axis hybrid mesh isolator using the pseudoelasticity of a shape memory alloy

    Science.gov (United States)

    Youn, Se-Hyun; Jang, Young-Soon; Han, Jae-Hung

    2011-07-01

    Launch vehicles and satellites experience severe vibration and pyroshock loads during flight phases. In particular, intense pyroshock, which is generated by the actuation of separation devices, can cause malfunctions in the electronic components in launch vehicles and satellites, potentially resulting in catastrophic failure during flight. This paper introduces a new three-axis hybrid mesh isolator using the pseudoelasticity of a shape memory alloy wire that was manufactured and tested to attenuate pyroshock and vibration transmitted to the electronic components. To characterize the isolation capability, quasi-static loading tests were performed; the test results showed that the pseudoelastic effect of the shape memory alloy wire significantly absorbs energy due to the stress-induced phase transformation. The ground pyroshock test results showed a remarkable pyroshock load attenuation of the hybrid mesh isolator in all frequency ranges. The dynamic characteristics and vibration isolation performances of the mesh isolators were also verified by random vibration tests. The healthiness of the hybrid mesh isolator was also studied under a harsh vibration loading level, and the results confirmed its wide applicability without degradation of the isolation capability.

  12. ENIDINE: Vibration and seismic isolation technologies for power generation station applications

    Energy Technology Data Exchange (ETDEWEB)

    Zemanek, T.A.

    1994-12-31

    ENIDINE Inc. is a world leader in the design and manufacture of shock and vibration mounts. Founded in 1966, the company has two manufacturing facilities, employs over 300 people and supports a worldwide network of distributors and representatives. ENIDINE Inc. is part of the ENIDINE Corporate Group which owns a number of companies that design and manufacture Hydraulic/Pneumatic cylinders, Electromechanical devices, Hydraulic Control Valves and a number of Industrial Distribution companies throughout Europe. In total, the ENIDINE Corporate Group has over 900 employees with annual sales of over $100 million. ENIDINE shock and vibration mounts are used to isolate the vibration of missiles from their guidance systems, pumps from hospital operating equipment and off shore oil rigs, from the shock energy of waves in the North Sea. ENIDINE products can be found on all Boeing and McDonnell Douglas aircraft, as well as many electronic and weapons systems on board Navy ships.

  13. Seismic Behavior of RNC-Isolated Bridges: A Comparative Study under Near-Fault, Long-Period, and Pulse-Like Ground Motions

    Directory of Open Access Journals (Sweden)

    Mohammed Ismail

    2016-01-01

    Full Text Available This paper introduces a recent seismic isolation system, named Roll-in-Cage (RNC isolator, for efficient protection of bridges against destructive earthquakes. The RNC isolator is a rolling-based isolation system with several integrated features in a single unit providing all the necessary functions of vertical rigid support, horizontal flexibility, full stability, hysteretic energy dissipation, and resistance to minor vibration loads. Besides, it is distinguished by a self-stopping (buffer mechanism to limit the peak bearing displacement under abrupt severe excitations, a linear gravity-based self-recentering mechanism to prevent permanent dislocations after excitations, and a notable resistance to axial tension. A three-span box-girder prestressed concrete bridge is investigated under a set of different destructive real and synthetic earthquakes including near-fault, long-period, and pulse-like ground motions. As a performance measure, the responses of isolated and nonisolated cases are compared. In addition, the RNC isolator’s behavior is then compared with those of other isolation systems including HDB, FPS, and LRB. The results confirmed that the RNC isolator has a superior behavior in achieving a balance between the peak displacements and accelerations of the isolated deck, relative other isolation systems, besides being the most (relatively efficient isolator in the great majority of studies performed.

  14. Isolation of differentially expressed sex genes in garden asparagus using suppression subtractive hybridization.

    Science.gov (United States)

    Deng, Chuan-liang; Wang, Ning-na; Li, Shu-fen; Dong, Tian-yu; Zhao, Xin-peng; Wang, Shao-jing; Gao, Wu-jun; Lu, Long-dou

    2015-09-01

    Garden asparagus (Asparagus officinalis L.) is a dioecious species whose male and female flowers are found in separate unisexual individuals. A region called the M-locus, located on a pair of homomorphic sex chromosomes, controls sexual dimorphism in asparagus. To date, no sex determining gene has been isolated from asparagus. To identify more genes involved in flower development in asparagus, subtractive hybridization library of male flowers in asparagus was constructed by suppression subtraction hybridization. A total of 107 expressed sequence tags (ESTs) were identified. BLASTX analysis showed that the library contained several genes that could be related to flower development. The expression patterns of seven selected genes believed to be involved in the development of asparagus male flower were further analyzed by semi-quantitative or real-time reverse-transcription polymerase chain reaction (RT-PCR). Results showed that AOEST4-5, AOEST12-40, and AOEST13-38 were strongly expressed in the male flower stage, whereas no transcript level of AOEST13-38 was detected in the female flower stage. The expression levels of AOEST13-87, AOEST13-92, AOEST13-40, and AOEST18-87 in the male flower stage were also higher than those in the female flower stage, although these transcripts were also expressed in other tissues. The identified genes can provide a strong starting point for further studies on the underlying molecular differences between the male and female flowers of asparagus.

  15. Theoretical and experimental study on seismic response control on top of Three-Gorges ship lift towers using magnetorheological intelligent isolation system and its keytechnique

    Institute of Scientific and Technical Information of China (English)

    Weilian QU; Jianwei TU

    2009-01-01

    A vertical ship lift under earthquake excitation may suffer from a whipping effect due to the sudden change of building lateral stiffness at the top of the ship lift towers. This paper proposes a roof magnetorheological (MR) intelligent isolation system to prevent the seismic whipping effect on machinery structures. Theoretically, the dynamic models of MR damper and the mechanical model of ship lift was established, the inverse neural network controlling algorithm was proposed and the fundamental semi-active control equation for the Three-Gorges ship lift where the MR intelligent isolation system was installed was deduced. Experimentally, the experimental model of the ship lift was given, the vibrating table experiment of the MR intelligent isolation system controlling the whipping effect was carried out and the results of the inverse neural network control strategy and passive isolation strategy were compared. In practical aspect, the large-scale MR damper (500kN) and a sliding support with limited stiffness were designed and fabricated. It was proven that the MR intelligent isolation system with proper control strategy can greatly reduce the seismic whipping effect on the top workshop of the ship lift and be simple and effective enough to be applied to real engineering structures.

  16. Spatially heterogeneous environmental selection strengthens evolution of reproductively isolated populations in a Dobzhansky-Muller system of hybrid incompatibility

    Science.gov (United States)

    Samuel A. Cushman; Erin L. Landguth

    2016-01-01

    Within-species hybrid incompatibility can arise when combinations of alleles at more than one locus have low fitness but where possession of one of those alleles has little or no fitness consequence for the carriers. Limited dispersal with small numbers of mate potentials alone can lead to the evolution of clusters of reproductively isolated genotypes despite...

  17. Etude de l'isolation hybride en vue de son application dans les transformateurs de puissance

    Science.gov (United States)

    Kassi, Koutoua Simon

    For nearly a century the conventional insulation (oil / cellulose complex) was the type of insulation used in the power transformers and most electrical power equipments. But the cellulose paper, the solid part of this insulation has many weaknesses. Indeed, the aging of cellulose paper in power transformers is accelerated by moisture, oxygen, metal catalysts, temperature, etc.). The risk of failures is thereby increased. Another major weakness of cellulose paper is its inability to protect the electrical transformer windings against the harmful effects of corrosive sulfur. Given all the weaknesses of cellulose paper, several studies have been conducted to evaluate the performance of aramid paper, which has better thermal properties. The aramid paper is currently used as high temperature insulation, combined with high fire point oils (synthetic and vegetable oils), mainly in electric traction transformers. The hybrid solid insulation is associated with mineral oil or with high fire point oils; it finds application in transformers of fixed and mobile substations. Manufacturing technology is controlled by manufacturers but operators of electrical networks do not have baseline data (standards) as diagnostic tools, allowing them to monitor the health/condition of the isolation in this new type of transformer. The overall objective of this research was to study the hybrid insulation and to demonstrate its potential use in power transformers. This overall objective has been subdivided into three specific objectives, namely: (i) improving the diagnostic of the condition of solid hybrid insulation and conventional solid insulation; (ii) diagnosing the condition of oils sampled from hybrid, high temperature and conventional insulation and finally (iii) investigating the ability of aramid paper and cellulose paper to protect the copper (electrical windings) against harmful effects of corrosive sulfur. In order to achieve these objectives, thermal accelerated aging were

  18. Isolator-free switchable uni- and bidirectional hybrid mode-locked erbium-doped fiber laser.

    Science.gov (United States)

    Chernysheva, Maria; Araimi, Mohammed Al; Kbashi, Hani; Arif, Raz; Sergeyev, Sergey V; Rozhin, Aleksey

    2016-07-11

    An Erbium-doped fibre ring laser hybrid mode-locked with single-wall carbon nanotubes (SWNT) and nonlinear polarisation evolution (NPE) without an optical isolator has been investigated for various cavity conditions. Precise control of the state of polarisation (SOP) in the cavity ensures different losses for counter-propagating optical fields. As the result, the laser operates in quasi-unidirectional regime in both clockwise (CW) and counter-clockwise (CCW) directions with the emission strengths difference of the directions of 22 dB. Furthermore, by adjusting the net birefringence in the cavity, the laser can operate in a bidirectional generation. In this case, a laser pumped with 75 mW power at 980 nm generates almost identical 790 and 570 fs soliton pulses with an average power of 1.17 and 1.11 mW. The operation stability and pulse quality of the soliton pulses in both unidirectional regimes are highly competitive with those generated in conventional ring fibre lasers with isolator in the cavity. Demonstrated bidirectional laser operation can find vital applications in gyroscopes or precision rotation sensing technologies.

  19. The genetic basis of postzygotic reproductive isolation between Drosophila santomea and D. yakuba due to hybrid male sterility.

    Science.gov (United States)

    Moehring, Amanda J; Llopart, Ana; Elwyn, Susannah; Coyne, Jerry A; Mackay, Trudy F C

    2006-05-01

    A major unresolved challenge of evolutionary biology is to determine the nature of the allelic variants of "speciation genes": those alleles whose interaction produces inviable or infertile interspecific hybrids but does not reduce fitness in pure species. Here we map quantitative trait loci (QTL) affecting fertility of male hybrids between D. yakuba and its recently discovered sibling species, D. santomea. We mapped three to four X chromosome QTL and two autosomal QTL with large effects on the reduced fertility of D. yakuba and D. santomea backcross males. We observed epistasis between the X-linked QTL and also between the X and autosomal QTL. The X chromosome had a disproportionately large effect on hybrid sterility in both reciprocal backcross hybrids. However, the genetics of hybrid sterility differ between D. yakuba and D. santomea backcross males, both in terms of the magnitude of main effects and in the epistatic interactions. The QTL affecting hybrid fertility did not colocalize with QTL affecting sexual isolation in this species pair, but did colocalize with QTL affecting the marked difference in pigmentation between D. yakuba and D. santomea. These results provide the basis for future high-resolution mapping and ultimately, molecular cloning, of the interacting genes that contribute to hybrid sterility.

  20. Design and application of wind-solar hybrid power system for unattended seismic stations in Shandong Province%风光发电系统在无人值守地震台站的设计

    Institute of Scientific and Technical Information of China (English)

    曲利; 董晓娜; 胡旭辉; 李永红; 蔡伟光

    2012-01-01

    风光互补发电技术在边防、通信、公路等已得到广泛应用,能否将这一绿色、清洁、可再生能源应用于地震无人值守台站,山东省在龙口地震台已做先期试点,通过一年试运行,风光互补发电系统能够满足地震无人值守台站的工作要求.%The wind-solar hybrid power technology is gradually matured in China. It is now widely used in military border post, telecommunications relay stations, roads and railway signal stations, geological exploration and field inspection stations and other remote areas. How to use this green, clean, renewable energy in unmanned seismic stations is a new problem. In Shandong Province, we took Longkou Seismic Station as an example first. Through running test of one year, it is found that the wind-solar hybrid power wind system can be fully applied in unmanned seismic stations. In this article, the application of the wind-solar hybrid power wind system in Longkou Seismic Station, where is far away from the city and lack of electricity supply systemi is introduced. This application achieved very good results.

  1. Development of seismic analysis model of LMFBR and seismic time history response analysis

    Energy Technology Data Exchange (ETDEWEB)

    Koo, K. H.; Lee, J. H.; Yoo, B. [KAERI, Taejon (Korea, Republic of)

    2001-05-01

    The main objective of this paper is to develop the seismic analysis model of KALIMER reactor structures including the primary coolant of sodium and to evaulate the seismic responses of the maximum peak acceleration and the relative displacements by the time history seismic response analysis. The seismic time history response analyses were carried out for both cases of the seismic isolation design and the non-isolation one to verify the seismic isolation performance. From the results of seismic response analysis using the developed seismic analysis model, it is clearly verified that the seismic isolation design gives very significantly reduced seismic responses compared with the non-isolation design. All design criteria for the relative displacement repsonse were satisfied for KALIMER reactor structures.

  2. Isolation and characterization of a human apoptosis-inducing gene with yeast two-hybrid system

    Institute of Scientific and Technical Information of China (English)

    齐兵; 齐义鹏; Masuo; Yutsudo; 刘青珍

    2000-01-01

    asy gene is a novel apoptosis-inducing gene, but its mechanism is unclear. To investigate the mechanism of asy inducing apoptosis, a novel gene encoding ASY interacting protein (asyip) is isolated from human lung cell line (WI-38) cDNA library with yeast two-hybrid system. The asyip gene is constitutively expressed as two mRNA transcripts with the size of 1.8 and 2.7 kb in various human tissues at different levels. Sequence analysis of full-length cDNA reveals that the two alternative transcripts of asyip gene contain common 5’ end and different 3’ end, and share a common open reading frame encoding a polypeptide of 236 amino acids. Two protein kinase C phosphorylation sites and two casein kinase II phosphorylation sites are found in ASYIP amino acid sequence. Two highly hydrophobic regions encoding potentially two transmembrane domains are present. The ASYIP protein contains a C-terminal endoplasmic reticulum retrieval signal (Lys-Lys-Lys-Ala-Glu). Immunoprecipitation assay confirmed the interaction of

  3. Isolation and characterization of a human apoptosis-inducing gene with yeast two-hybrid system

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    asy gene is a novel apoptosis-inducing gene,but its mechanism is unclear.To investigate the mechanism of asy inducing apoptosis,a novel gene encoding ASY interacting protein (asyip) is isolated from human lung cell line (WI-38) cDNA library with yeast two-hybrid system.The asyip gene is constitutively expressed as two mRNA transcripts with the size of 1.8 and 2.7 kb in various human tissues at different levels.Sequence analysis of full-length cDNA reveals that the two alternative transcripts of asyip gene contain common 5' end and different 3' end,and share a common open reading frame encoding a polypeptide of 236 amino acids.Two protein kinase C phosphorylation sites and two casein kinase II phosphorylation sites are found in ASYIP amino acid sequence.Two highly hydrophobic regions encoding potentially two transmembrane domains are present.The ASYIP protein contains a C-terminal endoplasmic reticulum retrieval signal (Lys-Lys-Lys-Ala-Glu).Immunoprecipitation assay confirmed the interaction of ASY and ASYIP in mammalian cells.Compared with asy gene,overexpression of asyip gene can inhibit growth of tumor cell Saos2 and induce cell apoptosis with a low efficiency.

  4. Rapid Detection of Rifampin-resistant Clinical Isolates of Mycobacterium tuberculosis by Reverse Dot Blot Hybridization

    Institute of Scientific and Technical Information of China (English)

    GUO Qian; WAN Kang Lin; YU Yan; ZHU Yan Ling; ZHAO Xiu Qin; LIU Zhi Guang; ZHANG Yuan Yuan; LI Gui Lian; WEI Jian Hao; WU Yi Mou

    2015-01-01

    Objective A PCR-reverse dot blot hybridization (RDBH) assay was developed for rapid detection of rpoB gene mutations in‘hot mutation region’ of Mycobacterium tuberculosis (M. tuberculosis). Methods 12 oligonucleotide probes based on the wild-type and mutant genotype rpoB sequences of M. tuberculosis were designed to screen the most frequent wild-type and mutant genotypes for diagnosing RIF resistance. 300 M. tuberculosis clinical isolates were detected by RDBH, conventional drug-susceptibility testing (DST) and DNA sequencing to evaluate the RDBH assay. Results The sensitivity and specificity of the RDBH assay were 91.2%(165/181) and 98.3%(117/119), respectively, as compared to DST. When compared with DNA sequencing, the accuracy, positive predictive value (PPV) and negative predictive value (NPV) of the RDBH assay were 97.7%(293/300), 98.2%(164/167), and 97.0%(129/133), respectively. Furthermore, the results indicated that the most common mutations were in codons 531 (48.6%), 526 (25.4%), 516 (8.8%), and 511 (6.6%), and the combinative mutation rate was 15 (8.3%). One and two strains of insertion and deletion were found among all strains, respectively. Conclusion Our findings demonstrate that the RDBH assay is a rapid, simple and sensitive method for diagnosing RIF-resistant tuberculosis.

  5. Enhancement of Lignin Biopolymer Isolation from Hybrid Poplar by Organosolv Pretreatments

    Directory of Open Access Journals (Sweden)

    Miao Wu

    2014-01-01

    Full Text Available Lignocellulosic biomass is an abundant renewable resource that has the potential to displace petroleum in the production of biomaterials and biofuels. In the present study, the fractionation of different lignin biopolymers from hybrid poplar based on organosolv pretreatments using 80% aqueous methanol, ethanol, 1-propanol, and 1-butanol at 220°C for 30 min was investigated. The isolated lignin fractions were characterized by Fourier transform infrared spectroscopy (FT-IR, high-performance anion exchange chromatography (HPAEC, 2D nuclear magnetic resonance (2D NMR, and thermogravimetric analysis (TGA. The results showed that the lignin fraction obtained with aqueous ethanol (EOL possessed the highest yield and the strongest thermal stability compared with other lignin fractions. In addition, other lignin fractions were almost absent of neutral sugars (1.16–1.46% though lignin preparation extracted with 1-butanol (BOL was incongruent (7.53%. 2D HSQC spectra analysis revealed that the four lignin fractions mainly consisted of β-O-4′ linkages combined with small amounts of β-β′ and β-5′ linkages. Furthermore, substitution of Cα in β-O-4′ substructures had occurred due to the effects of dissolvent during the autocatalyzed alcohol organosolv pretreatments. Therefore, aqueous ethanol was found to be the most promising alcoholic organic solvent compared with other alcohols to be used in noncatalyzed processes for the pretreatment of lignocellulosic biomass in biorefinery.

  6. Study of quality factor and hysteresis associated with the state-of-the-art passive seismic isolation system for Gravitational Wave Interferometric Detectors

    Science.gov (United States)

    Desalvo, R.; Márka, Sz.; Numata, K.; Sannibale, V.; Takamori, A.; Tariq, H.; Ugas, E. J.; Yoda, T.; Aso, Y.; Bertolini, A.

    2005-02-01

    Seismic isolation systems, consistent of passive attenuators, based on mechanical harmonic oscillators with resonant frequencies below the frequency region of interest, are being used by multiple Gravitational wave (GW) detectors. We conduct a study of the fundamental limitations present due to the properties of the material such as Maraging steel, used in some of the seismic attenuation systems for GW detectors. We tentatively interpret the main effects observed in our system, such as the anomalous damping and the hysteresis, in terms of movement of dislocations trapped between Maraging steel intermetallic precipitates. In light of our understanding, we further discuss and propose ideas to overcome these limitations and improve the performance of these systems, which may allow for passive attenuation at even lower-frequency regimes than achieved so far. These advanced performances would help further reduce the requirements on the mirror suspension control actuators and could reduce their associated noise in the present Gravitational Wave Interferometric Detectors (GWID). This advancement can lead to more suitable seismic attenuation systems for the future instruments with lower frequency sensitivity requirements.

  7. IMPLEMENTATION OF A REAL TIME SUPERVISORY CONTROLLER FOR AN ISOLATED HYBRID (WIND/ SOLAR/DIESEL) POWER SYSTEM

    OpenAIRE

    Boopathy C P; Dr.Sivakumar L

    2014-01-01

    In most of the developing countries like India and South Africa, there exists still many remote places (isolated from the grid); where the electrification is unavailable due to the financial aspect related to establishing the infrastructure to distribute power over a long distance and consequent high transmission losses. Authors emphasize for an Autonomous Hybrid Power Systems (AHPS), which will eradicate the problems faced by the remote places. Integration of Wind/Solar/Diesel also ensures t...

  8. Isolation of cDNAs of scrapie-modulated RNAs by subtractive hybridization of a cDNA library.

    OpenAIRE

    1988-01-01

    We have developed a subtractive cloning procedure based on the hybridization of single-stranded cDNA libraries constructed in pi H3M, a vector containing the phage M13 origin of replication. We have used this strategy to isolate three transcripts whose abundance is increased in scrapie-infected brain. DNA sequence analysis showed that they represent glial fibrillary acidic protein, metallothionein II, and the B chain of alpha-crystallin; the latter two may represent a response to stress.

  9. Identification of the specificity of isolated phage display single-chain antibodies using yeast two-hybrid screens

    DEFF Research Database (Denmark)

    Rasmussen, Nicolaj; Ditzel, Henrik

    2009-01-01

    A method is described for the identification of the antigen recognised by an scFv isolated from an antibody phage display library using selection against a complex mixture of proteins (e.g. intact cells, purified cell surface membranes, and tissue sections). The method takes advantage of a yeast ...... two-hybrid system that additionally allows for reorganization of post-translational modifications to the bait and target proteins. This technique is therefore especially useful for identifying surface-expressed antigens....

  10. Lambda exonuclease-based subtractive hybridization approach to isolate differentially expressed genes from leaf cultures of Paulownia kawakamii.

    Science.gov (United States)

    Low, R K; Prakash, A P; Swarup, S; Goh, C J; Kumar, P P

    2001-08-15

    Genes that are preferentially expressed in a particular developmental pathway can be isolated by subtractive hybridization (SH). We developed a PCR-based approach coupled with lambda exonuclease digestion that allows for generating single-stranded tester and driver nucleic acids suitable for SH starting from cDNA libraries. An efficient subtraction strategy was developed to overcome some of the problems in the previously described SH protocols, such as the need for large amounts of experimental tissue, RNase contamination during solution hybridization, and postsubtraction recovery of nucleic acids. We used this method to obtain cDNA corresponding to genes expressed during adventitious shoot regeneration from excised leaf cultures of the fast-growing tree Paulownia kawakamii. Over 36 cDNA clones were isolated and 1 of the differentially expressed clones codes for a leucine zipper transcription factor. This clone showed about sixfold higher level of expression in the shoot-forming tissues (tester) compared to that in the callus-forming tissues (driver) of Paulownia, suggesting that differentially expressed genes can be efficiently isolated using this simple lambda exonuclease-based subtractive hybridization method.

  11. REGULATION OF SEISMIC LOAD ON BUILDINGS SEISMIC DEVICES

    Directory of Open Access Journals (Sweden)

    Kh. N. Mazhiev

    2013-01-01

    Full Text Available The issues of regulation of seismic loads on structures using kinematic supports of highstrength concrete on the impregnated coarse aggregate and seismic isolation bearings Belleville. The results of experimental studies related to the obtaining of a new coarse aggregate and construction of seismic isolation bearings. Addresses the issues of interaction forces in thehemispherical supports vibration process.

  12. From array-based hybridization of Helicobacter pylori isolates to the complete genome sequence of an isolate associated with MALT lymphoma

    Directory of Open Access Journals (Sweden)

    Mégraud Francis

    2010-06-01

    Full Text Available Abstract Background elicobacter pylori infection is associated with several gastro-duodenal inflammatory diseases of various levels of severity. To determine whether certain combinations of genetic markers can be used to predict the clinical source of the infection, we analyzed well documented and geographically homogenous clinical isolates using a comparative genomics approach. Results A set of 254 H. pylori genes was used to perform array-based comparative genomic hybridization among 120 French H. pylori strains associated with chronic gastritis (n = 33, duodenal ulcers (n = 27, intestinal metaplasia (n = 17 or gastric extra-nodal marginal zone B-cell MALT lymphoma (n = 43. Hierarchical cluster analyses of the DNA hybridization values allowed us to identify a homogeneous subpopulation of strains that clustered exclusively with cagPAI minus MALT lymphoma isolates. The genome sequence of B38, a representative of this MALT lymphoma strain-cluster, was completed, fully annotated, and compared with the six previously released H. pylori genomes (i.e. J99, 26695, HPAG1, P12, G27 and Shi470. B38 has the smallest H. pylori genome described thus far (1,576,758 base pairs containing 1,528 CDSs; it contains the vacAs2m2 allele and lacks the genes encoding the major virulence factors (absence of cagPAI, babB, babC, sabB, and homB. Comparative genomics led to the identification of very few sequences that are unique to the B38 strain (9 intact CDSs and 7 pseudogenes. Pair-wise genomic synteny comparisons between B38 and the 6 H. pylori sequenced genomes revealed an almost complete co-linearity, never seen before between the genomes of strain Shi470 (a Peruvian isolate and B38. Conclusion These isolates are deprived of the main H. pylori virulence factors characterized previously, but are nonetheless associated with gastric neoplasia.

  13. Hybrid Non-Isolated and Non Inverting Nx Interleaved DC-DC Multilevel Boost Converter for Renewable Energy Applications

    DEFF Research Database (Denmark)

    Bhaskar, Mahajan Sagar; Kulkarni, Rishi M.; Padmanaban, Sanjeevi Kumar;

    2016-01-01

    In this paper hybrid non isolated/ non inverting Nx interleaved DC-DC multilevel Boost Converter for renewable energy applications is presented. The presented hybrid topology is derived from the conventional interleaved converter and the Nx Multilevel boost converter. In renewable energy...... applications, generated energy cannot be directly used at application end. In most of the cases it needs to be stepped up with DC-DC converter at operating voltage levels as per the requirement of the application. Though conventional boost converter can theoretically be used for this purpose, but obtaining....... The advantages of presenting topology of DC-DC converter are high voltage conversion, reduce ripple, low voltage stress, non inverting without utilizing the high duty and transformer. The main advantage of presented topology is more number of levels can be increased by adding capacitor and diode circuitry...

  14. Non Isolated and Non-Inverting Cockcroft Walton Multiplier Based Hybrid 2Nx Interleaved Boost Converter For Renewable Energy Applications

    DEFF Research Database (Denmark)

    Bhaskar, Mahajan Sagar; Padamanaban, Sanjeevi Kumar; Blaabjerg, Frede

    2016-01-01

    In this paper hybrid non isolated and non-invertingCockcroft-Walton multiplier based 2Nx InterleavedBoost converter (2Nx IBC) for renewable energy applications is presented. The presented hybrid boost converter topology is derived from non-inverting Nx Multilevel Boost Converter (Nx MBC......) and inverting Nx Multilevel Boost Converter (Nx MBC). In renewable energy applications, generated voltage needs to be stepped up with high conversion ratio using a DC-DC converter at voltage levels as per the application requirement. The advantages of the presentedtopology of interleaved converter are high...... voltage conversion ratio, reduce ripple, low voltage stress, non-inverting output voltage without utilizing the high duty cycle, coupled inductors and transformer. The main advantage of presented topology consists in increasing voltage gain by adding capacitor and diode into circuitry without disturbing...

  15. 近断层地震动作用下桥梁结构的组合隔震分析%Hybrid isolation analysis of bridge structure excited by near-fault ground motion

    Institute of Scientific and Technical Information of China (English)

    郭红锋; 宁响亮; 谭平; 庾光忠; 唐璐; 刘军

    2011-01-01

    为改善近断层地震动作用下隔震桥梁结构的抗震性能,基于Benchmark结构振动控制问题,研究附加黏滞阻尼器、磁流变(MR)阻尼器的组合隔震策略.非线性动力分析过程中,优化了黏滞阻尼器的阻尼系数和速度指数,并设计了分散模糊控制器来确定施加给磁流变阻尼器的电压.研究结果表明:采用黏滞阻尼器和磁流变阻尼器可提高隔震桥梁结构在近断层地震动作用下的安全性,结构绝大多数响应,尤其是隔震支座的变形得到明显减小;与采用黏滞阻尼器进行组合隔震相比,采用磁流变阻尼器的智能模糊控制方案出力相对较小、控制效果更好,同时,即使在外部电源供给中断的情况下,磁流变阻尼器仍然能发挥一定的作用,具有失效-安全的优点.%To improve the seismic performance of isolated bridge subjected to near-fault earthquakes, benchmark structural vibration control for a seismically excited highway bridge is used as a numerical example to demonstrate the effectiveness of the hybrid isolation system with viscous damper and magnetorheological (MR) damper. In the process of nonlinear dynamic analysis, the damping coefficient and velocity index of viscous damper are optimized, and the decentralized fuzzy logic control method is employed to determine the voltage value applied to the MR damper. Results show that the hybrid isolation system based on the two kinds of damper can significantly improve the bridge' s safety under near-fault earthquake and the dynamic responses, especially the isolation bearing deformation are greatly reduced. In comparison with the passive viscous damper control, MR damper based on intelligent fuzzy logic control system has the advantage in requiring less control force and obtaining better control performance, furthermore, even without providing voltage, MR damper is also capable of mitigating the responses.

  16. Characterization of serogroup C meningococci isolated from 14 provinces of China during 1966—2005 using comparative genomic hybridization

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Neisseria meningitidis is a major cause of bacterial meningitis and septicemia worldwide. In China, serogroup A strains were responsible for over 95% of the cases, while serogroup B strains were mainly the cause of localized outbreaks and sporadic cases. Before 2003, serogroup C strains were only re-covered from a few sporadic cases. However, a sudden increase in the number of cases due to sero-group C strains occurred during 2003—2005 in Anhui Province, China. Many cases were found in other provinces at the same time. Multilocus sequence typing (MLST) results indicated that the unique se-quence type 4821 clone meningococci, a new hyper-virulent lineage, was responsible for the serogroup C meningitis outbreaks. We have completed the project of sequencing the whole genome of the Chi-nese N. meningitidis serogroup C representative isolate 053442. We fabricated a whole-genome mi-croarray of N. meningitidis isolate 053442 and analyzed the genome composition differences among 81 serogroup C isolates which were isolated from 14 provinces of China during 1966—2005. The com-parative genomic hybridization (CGH) result shows that the genome compositions of nearly all sero-group C isolates are similar to that of 053442. The products of many absent open reading frames (ORFs) are conserved hypothetical proteins. The results will provide a valuable resource from which one can analyze the genome composition and genetic background of serogroup C meningococci in China.

  17. Characterization of serogroup C meningococci isolated from 14 provinces of China during 1966-2005 using comparative genomic hybridization

    Institute of Scientific and Technical Information of China (English)

    PENG JunPing; ZHANG XiaoBing; YANG E; WANG Jing; YANG Jian; SHAO ZhuJun; JIN Qi

    2007-01-01

    Neisseria meningitidis is a major cause of bacterial meningitis and septicemia worldwide. In China, serogroup A strains were responsible for over 95% of the cases, while serogroup B strains were mainly the cause of localized outbreaks and sporadic cases. Before 2003, serogroup C strains were only recovered from a few sporadic cases. However, a sudden increase in the number of cases due to serogroup C strains occurred during 2003-2005 in Anhui Province, China. Many cases were found in other provinces at the same time. Multilocus sequence typing (MLST) results indicated that the unique sequence type 4821 clone meningococci, a new hyper-virulent lineage, was responsible for the serogroup C meningitis outbreaks. We have completed the project of sequencing the whole genome of the Chinese N. meningitidis serogroup C representative isolate 053442. We fabricated a whole-genome microarray of N. meningitidis isolate 053442 and analyzed the genome composition differences among 81 serogroup C isolates which were isolated from 14 provinces of China during 1966-2005. The comparative genomic hybridization (CGH) result shows that the genome compositions of nearly all serogroup C isolates are similar to that of 053442. The products of many absent open reading frames (ORFs) are conserved hypothetical proteins. The results will provide a valuable resource from which one can analyze the genome composition and genetic background of serogroup C meningococci in China.

  18. The Chaotic-Based Control of Three-Port Isolated Bidirectional DC/DC Converters for Electric and Hybrid Vehicles

    Directory of Open Access Journals (Sweden)

    Zheng Wang

    2016-01-01

    Full Text Available Three-port isolated (TPI bidirectional DC/DC converters have three energy ports and offer advantages of large voltage gain, galvanic isolation ability and high power density. For this reason this kind of converters are suitable to connect different energy sources and loads in electric and hybrid vehicles. The purpose of this paper is to propose chaotic modulation and the related control scheme for TPI bidirectional DC/DC converters, in such a way that the switching harmonic peaks can be suppressed in spectrum and the conducted electromagnetic interference (EMI is reduced. Two chaotic modulation strategies, namely the continuously chaotic modulation and the discretely chaotic modulation are presented. These two chaotic modulation strategies are applied for TPI bidirectional DC/DC converters with shifted-phase angle based control and phase-shifted PWM control. Both simulation and experiments are given to verify the validity of the proposed chaotic modulation-based control schemes.

  19. Report of reprocessing of reflection seismic profile X-5 Waste Isolation Pilot Plant site, Eddy County, New Mexico

    Science.gov (United States)

    Miller, John J.

    1983-01-01

    Seismic reflection profile X-5 exhibits a 7,700 ft long anomalous zone of poor quality to nonexistent reflections between shotpoints 100 and 170, compared to the high-quality, flat-lying, coherent reflections on either side. Results from drill holes in the area suggest 'layer cake' geology with no detectable abnormalities such as faults present. In an attempt to determine whether the anomalous zone of the seismic profile is an artifact or actually indicates a geologic condition, the data were extensively reprocessed using state-of-the-art processing techniques and the following conclusions were made: 1. The field-recorded data in the anomalous zone are of poor quality due to surface conditions and recording parameters used. 2. Reprocessing shows reflectors throughout the anomalous zone at all levels. However, it cannot prove that the reflectors are continuous throughout the anomalous zone. 3. Significant improvement in data quality may be achieved if the line is reshot using carefully determined recording parameters.

  20. Development of a novel multi-layer MRE isolator for suppression of building vibrations under seismic events

    Science.gov (United States)

    Yang, Jian; Sun, Shuaishuai; Tian, Tongfei; Li, Weihua; Du, Haiping; Alici, Gursel; Nakano, Masami

    2016-03-01

    Protecting civil engineering structures from uncontrollable events such as earthquakes while maintaining their structural integrity and serviceability is very important; this paper describes the performance of a stiffness softening magnetorheological elastomer (MRE) isolator in a scaled three storey building. In order to construct a closed-loop system, a scaled three storey building was designed and built according to the scaling laws, and then four MRE isolator prototypes were fabricated and utilised to isolate the building from the motion induced by a scaled El Centro earthquake. Fuzzy logic was used to output the current signals to the isolators, based on the real-time responses of the building floors, and then a simulation was used to evaluate the feasibility of this closed loop control system before carrying out an experimental test. The simulation and experimental results showed that the stiffness softening MRE isolator controlled by fuzzy logic could suppress structural vibration well.

  1. EFFECT OF FRICTION BEARING RATIO ON SEISMIC ISOLATION PERFORMANCE OF PARALLEL COMPOSITE ISOLATION SYSTEM%摩擦承压比对并联复合隔震体系隔震性能的影响研究

    Institute of Scientific and Technical Information of China (English)

    袁颖; 周爱红; 杨树标; 何国峰

    2014-01-01

    In order to investigate how the friction bearing ratio affects the seismic isolation performance of parallel composite isolation system ,the numerical simulation was carried out by the time-history analysis method ,in which the seismic responses were calculated for parallel composite isolation systems with different friction bearing ratios under different seismic acceleration peak values .Then,the effects of different friction bearing ratios on the maximum base shear coefficients and the maximum base displacements , the hysteretic characteristics and nonlinear properties were analyzed and discussed .The results show that the friction bearing ratio is a key factor affecting the isolation performance;different parallel composite isolation systems can be designed according to friction bearing ratios and thus provide good isolation performance within reasonable range of friction bearing ratios .Moreover , there is an optimal relation between the maximum base shear coefficient and the friction bearing ratio , and the nonlinear properties are closely related to the friction bearing ratio and seismic acceleration peak value .%为了解摩擦承压比对并联复合隔震体系隔震性能的影响,采用时程分析方法开展不同地震动加速度峰值下不同摩擦承压比的并联复合隔震体系地震响应的数值模拟研究,深入分析并讨论并联复合隔震体系的不同摩擦承压比对基底最大剪力系数、基底最大位移、隔震层滞回特性以及并联复合隔震体系非线性性能的影响。计算和分析结果表明:摩擦承压比是影响并联复合隔震体系隔震性能的关键因素,可根据摩擦承压比的不同,设计出不同参数的并联复合隔震体系,在合理的摩擦承压比取值范围内并联复合隔震体系具有良好的隔震性能。此外,并联复合隔震体系的基底最大剪力系数与摩擦承压比之间存在一个最优关系,并联复合隔震体系的非线性特

  2. Characterisation by molecular hybridization of RNA fragments isolated from ancient (1400 B.C.) seeds.

    Science.gov (United States)

    Rollo, F

    1985-12-01

    The analysis of cress seeds from Thebes dated approximately 1400 years B.C. showed that fragments of RNA up to 10 bases in length were still present in the ancient seeds. After having been made radioactive at the 5'OH terminus, the RNA fragments were used as probes in a spot hybridization experiment. They were shown to hybridize to cress DNA and, to a lesser extent, to that of phylogenetically distant species. When fixed onto nitrocellulose and probed with different cloned genes, the RNA fragments were shown to originate from breakage of the 25 and 18s cytoplasmic rRNA.

  3. Molecular basis underlying the S5-dependent reproductive isolation and compatibility of indica/japonica rice hybrids.

    Science.gov (United States)

    Ji, Qing; Zhang, Meijing; Lu, Jufei; Wang, Hongmei; Lin, Bing; Liu, Qiaoquan; Chao, Qing; Zhang, Yan; Liu, Chunxia; Gu, Minghong; Xu, Mingliang

    2012-03-01

    The S5 locus regulates spikelet fertility of indica/japonica hybrid rice (Oryza sativa). There are three alleles at the S5 locus, including an indica allele (S5i), a japonica allele (S5j), and a wide-compatibility allele (S5n). This study analyzed the molecular basis for S5-dependent reproductive isolation and compatibility of indica/japonica rice hybrids. Three S5 alleles were expressed at extremely low levels, and only in the ovary. S5n was more similar to S5i in both RNA and protein expression profiles. The S5 locus was not essential for embryo sac development, although deleterious interactions between S5i and S5j resulted in reduced rates of spikelet fertility. The yeast two-hybrid system was used to test direct interactions between S5-encoded proteins. The results indicated that the S5i- and S5j-encoded eukaryotic aspartyl proteases formed both homodimers and heterodimers, whereas the S5n-encoded aspartyl protease was incapable of dimerization. Site-directed mutagenesis revealed that a single amino acid difference between S5i- and S5j-encoded aspartyl proteases (phenylalanine/leucine at residue 273) was primarily responsible for embryo sac abortion. The S5 locus may have promoted the subspeciation of indica and japonica, but it also enables gene flow between them.

  4. Isolating Soil Drought-Induced Genes from Maize Seedling Leaves Through Suppression Subtractive Hybridization

    Institute of Scientific and Technical Information of China (English)

    LI Hui-yong; HUANG Su-hua; SHI Yun-su2; SONG Yan-chun; ZHAO Jiu-ran; WANG Feng-ge; WANG Tian-yu; LI Yu

    2007-01-01

    In this study, a forward cDNA library was constructed by suppression subtractive hybridization using seedling leaves of CN165, a drought-tolerant maize inbred line. In the suppression subtractive hybridization (SSH) library, 672 positive clones were picked up randomly. After polymerase chain reaction (PCR) of each clone, all the single clones were sequenced. Totally 598 available sequences were obtained. After cluster analysis of the EST sequences, 80 uniESTs were obtained, among which 57 uniESTs were contigs and 23 uniESTs were singlets. The results of BLASTN showed that all the uniESTs had homologous sequences in the nr database. The BLASTX results indicated that 68 uniESTs had significant protein homology, 8 uniESTs with homology of unknown proteins and putative proteins, and 4 uniESTs without protein homology. Those drought stress-induced genes were involved in many metabolism pathways to regulate plant growth and development under drought stress.

  5. 对连续梁桥减隔震支座抗震性能的比较分析%Seismic Isolation Bearing On the Comparative Analysis of the Seismic Performance for Continuous Beam Bridge

    Institute of Scientific and Technical Information of China (English)

    史康; 全健; 王福敏; 耿波

    2014-01-01

    以厦漳跨海大桥北汊南引桥为依托,采用有限元非线性时程分析方法,比较分析了铅芯橡胶支座和盆式橡胶支座对高烈度地区大跨径连续箱梁桥的抗震影响。研究结果表明:铅芯橡胶支座增加了结构在地震作用下的振动周期和主梁梁端位移,减小了固定墩的受力。相比盆式橡胶支座,铅芯橡胶支座可以使主梁梁端位移增加20%~200%,固定墩内力减小36%~80%。说明铅芯橡胶支座能够通过增加主梁位移达到减小桥墩受力的效果,隔震效果明显。该研究成果可为同类型桥梁的抗震设计提供参考。%Based on north south approach spans of Xiamen -zhangzhou cross-sea bridge by using the finite element nonlinear a-nalysis method, the seismic impact is compared between lead -rubber bearing and pot rubber bearing on the long span box girder bridges in high-intensity areas .The results show that the lead -rubber bearing can increase the vibration period and displacement of main beam in earthquake , reduce the force of fixed piers .Compared with pot rubber bearing , adopting lead-rubber bearing can in-crease the end displacement of main grider by 20%to 200%, meanwhile decrease internal force for fixed piers by 36%to 80%.The isolation effect is obvious that lead -rubber bearings can reduce the pier force by increasing the displacement of main beam .The re-search results provide a reference for the same type of bridge seismic design .

  6. Hybrid graphene/silicon integrated optical isolators with photonic spin-orbit interaction

    CERN Document Server

    Ma, Jingwen; Yu, Zejie; Sun, Xiankai

    2016-01-01

    Optical isolators are an important building block in photonic computation and communication. In traditional optics, isolators are realized with magneto-optical garnets. However, it remains challenging to incorporate such materials on an integrated platform because of the difficulty in material growth and bulky device footprint. Here, we propose an ultracompact integrated isolator by exploiting graphene's magneto-optical property on a silicon-on-insulator platform. The photonic nonreciprocity is achieved because the cyclotrons in graphene experiencing different optical spin exhibit different response to counterpropagating light. Taking advantage of cavity resonance effects, we have numerically optimized a device design, which shows excellent isolation performance with the extinction ratio over 45 dB and the insertion loss around 12 dB at a wavelength near 1.55 um. Featuring graphene's CMOS compatibility and substantially reduced device footprint, our proposal sheds light to monolithic integration of nonrecipro...

  7. Hybridization and asymmetric reproductive isolation between the closely related bryophyte taxa Polytrichum commune and P. uliginosum

    NARCIS (Netherlands)

    van der Velde, M; Bijlsma, R

    2004-01-01

    Based on genetic differentiation, the haploid dioecious bryophyte taxa Polytrichum commune and P. uliginosum have been inferred to be completely reproductively isolated. However, analysing diploid sporophytes from a sympatric population for three diagnostic microsatellite markers, we show here that

  8. Rapid isolation and characterization of hybridization selected recombinants from lambda genomic libraries.

    Science.gov (United States)

    Porteous, D J

    1986-11-15

    This paper describes an efficient protocol for the screening of lambda genomic libraries, plaque and DNA purification, and probe characterization by a combination of new and recently described techniques. The protocol has allowed large numbers of human subchromosome-specific probes to be rapidly generated from an EMBL3 library of human-mouse somatic cell hybrid DNA. The protocol affords considerable savings in time and effort over previous procedures.

  9. 弹塑性钢减隔震支座在桥梁抗震设计中的应用%Application of Elasto-Plastic Steel Seismic Isolators to Bridge Anti-Seismic Design

    Institute of Scientific and Technical Information of China (English)

    高山; 彭泽友; 史春娟; 王永祥

    2015-01-01

    为了给桥梁抗震设计提供参考,以减轻桥梁结构在地震中遭受的损伤,介绍一种弹塑性钢减隔震支座(NDQZ)的结构特点及其减隔震原理,并以(83+140+83) m双塔双索面预应力混凝土斜拉桥为实例进行减隔震分析。采用有限元分析软件SAP2000建立全桥有限元模型,在E2地震状态下分别进行非减隔震支座桥梁和NDQZ支座桥梁地震动力时程分析。结果表明:NDQZ支座可实现全桥协同抗震,减隔震效果良好;采用NDQZ支座后,桥梁前3阶自振周期平均延长133%,在顺桥向和横桥向墩底弯矩分别减小了40%和83%,墩底剪力分别减小了39%和70%;承台底弯矩分别减小了39%和74%,承台底剪力分别减小了34%和60%;弯矩和剪力分布均匀。%To provide reference for bridge anti‐seismic design and reduce the damage that bridge suffers in earthquakes ,the structural features and principles of vibration mitigation and iso‐lation of a kind of elasto‐plastic steel seismic isolators (NDQZ)is introduced .A two‐pylon pres‐tressed concrete cable‐stayed bridge with span arrangement of (83+140+83) m and with double cable planes is cited as an example to conduct vibration mitigation and isolation analysis .T he finite element software SAP2000 was used to establish the finite element model of the whole bridge ,to carry out time‐history analysis of the bridge with bearings incapable of vibration mitigation and iso‐lation effect and the bridge with NDQZ under the E2 earthquake condition respectively .The re‐sults of the analysis indicate that the NDQZ bearings can realize the effect of the w hole‐bridge col‐laborative vibration resistance ,displaying sound vibration mitigation and isolation effect .When the NDQZ bearings are used ,the first three orders of bridge natural vibration period averagely ex‐tends 133% .The bending moments in the base of the piers along the bridge length

  10. Hybrids of Shigatoxigenic and Enterotoxigenic Escherichia coli (STEC/ETEC) Among Human and Animal Isolates in Finland.

    Science.gov (United States)

    Nyholm, O; Heinikainen, S; Pelkonen, S; Hallanvuo, S; Haukka, K; Siitonen, A

    2015-11-01

    Diarrhoeagenic Escherichia coli (DEC) cause serious foodborne infections in humans. Total of 450 Shigatoxigenic E. coli (STEC) strains isolated from humans, animals and environment in Finland were examined by multiplex PCR targeting the virulence genes of various DEC pathogroups simultaneously. One per cent (3/291) of the human STEC and 14% (22/159) of the animal and environmental STEC had genes typically present in enterotoxigenic E. coli (ETEC). The strains possessed genes encoding both Shiga toxin 1 and/or 2 (stx1 and/or stx2 ) and ETEC-specific heat-stable (ST) enterotoxin Ia (estIa). The identified stx subtypes were stx1a, stx1c, stx2a, stx2d and stx2g. The three human STEC/ETEC strains were isolated from the patients with haemolytic uraemic syndrome and diarrhoea and from an asymptomatic carrier. The animal STEC/ETEC strains were isolated from cattle and moose. The human and animal STEC/ETEC strains belonged to 11 serotypes, of which O2:H27, O15:H16, O101:H-, O128:H8 and O141:H8 have previously been described to be associated with human disease. Identification of multiple virulence genes offers further information for assessing the virulence potential of STEC and other DEC. The emergence of novel hybrid pathogens should be taken into account in the patient care and epidemiological surveillance.

  11. Hybridization, natural selection, and evolution of reproductive isolation: a 25-years survey of an artificial sympatric area between two mosquito sibling species of the Aedes mariae complex.

    Science.gov (United States)

    Urbanelli, Sandra; Porretta, Daniele; Mastrantonio, Valentina; Bellini, Romeo; Pieraccini, Giuseppe; Romoli, Riccardo; Crasta, Graziano; Nascetti, Giuseppe

    2014-10-01

    Natural selection can act against maladaptive hybridization between co-occurring divergent populations leading to evolution of reproductive isolation among them. A critical unanswered question about this process that provides a basis for the theory of speciation by reinforcement, is whether natural selection can cause hybridization rates to evolve to zero. Here, we investigated this issue in two sibling mosquitoes species, Aedes mariae and Aedes zammitii, that show postmating reproductive isolation (F1 males sterile) and partial premating isolation (different height of mating swarms) that could be reinforced by natural selection against hybridization. In 1986, we created an artificial sympatric area between the two species and sampled about 20,000 individuals over the following 25 years. Between 1986 and 2011, the composition of mating swarms and the hybridization rate between the two species were investigated across time in the sympatric area. Our results showed that A. mariae and A. zammitii have not completed reproductive isolation since their first contact in the artificial sympatric area. We have discussed the relative role of factors such as time of contact, gene flow, strength of natural selection, and biological mechanisms causing prezygotic isolation to explain the observed results. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  12. Active Fault Detection and Isolation for Hybrid Systems

    DEFF Research Database (Denmark)

    Gholami, Mehdi; Schiøler, Henrik; Bak, Thomas;

    2009-01-01

    models predicted outputs such that their discrepancies are observable by passive fault diagnosis technique. Isolation of different faults is done by implementation a bank of Extended Kalman Filter (EKF) where the convergence criterion for EKF is confirmed by Genetic Algorithm (GA). The method is applied......An algorithm for active fault detection and isolation is proposed. In order to observe the failure hidden due to the normal operation of the controllers or the systems, an optimization problem based on minimization of test signal is used. The optimization based method imposes the normal and faulty...

  13. 某幼儿园基础隔震结构抗震性能分析%Seismic behavior analysis of based isolation structure in a kindergarten

    Institute of Scientific and Technical Information of China (English)

    江泳

    2014-01-01

    In a basement column base isolation four floor frame structure of kindergarten,establishing 3D model applied of the finite element software ETABS for time history analysis,analyzing the seismic performance of whole structure under ultra intensity earthquake. The results showed that:story shear force decreased significantly under the frequent earthquake of 7 degree(0. 15g),the upper part of the structure is basically elastic,independent col-umn displacement angle is still minimum,floor acceleration damping effect is remarkable and the comfortable degree of human body is greatly improved,the isolation layer is stable and have adequate security,it show that the isolation design improves the safety of the structural significantly. In the application of engineering,we suggest that these sim-ilar isolated buildings should increase the stiffness of the independent column and and prefer the larger diameter iso-lation bearing.%对某地下室柱顶基础隔震的4层框架结构幼儿园,应用有限元软件ETABS建模进行时程分析,分析超烈度地震作用下整体结构的抗震性能并重点讨论下部独立悬臂柱的抗震设计。结果表明:设防烈度7度(0.15g)多遇地震作用下,层间剪力减震效果显著;7度(0.15g)罕遇地震作用下,上部结构基本处于弹性,独立柱位移角极小;超烈度8度(0.20g)罕遇地震作用下,独立柱位移角仍然极小,楼层加速度减震效果显著,人体舒适度大为提高,隔震层仍然具有足够的稳定性和安全性,表明隔震设计显著提高了结构安全性。建议工程应用中类似隔震建筑在不影响地下室的使用功能条件下,加大独立柱刚度并优先选择较大直径的隔震支座。

  14. Active Fault Detection and Isolation for Hybrid Systems

    DEFF Research Database (Denmark)

    Gholami, Mehdi; Schiøler, Henrik; Bak, Thomas

    2009-01-01

    An algorithm for active fault detection and isolation is proposed. In order to observe the failure hidden due to the normal operation of the controllers or the systems, an optimization problem based on minimization of test signal is used. The optimization based method imposes the normal and fault...... to the two tank bench mark example in presence of two faults....

  15. 平西府车辆段与综合基地(运用库)高位隔震设计分析%High-position seismic isolation design of the Pingxifu vehicle depot and comprehensive base structures

    Institute of Scientific and Technical Information of China (English)

    黄跃斌; 杨铮; 万红宇; 冯慧君; 朱兴刚

    2011-01-01

    基于高位隔震结构的动力特性及影响高位隔震结构隔震效果的主要参数——频率比、质量比,介绍了地震波的选取及输入方式和高位隔震结构隔震层、隔震层以上结构、隔震层以下结构的抗震性能目标,以及振型分解反应谱法中隔震支座等效刚度的计算方法。采用ETABS软件对高位隔震结构进行计算分析,采用ETABS中Link单元模拟隔震支座,进行了非线性时程法及振型分解反应谱法分析,同时采用了PKPM等效剪切刚度的计算方法。经过分析,高位隔震结构隔震层以上结构可按降低一度进行设计,隔震层、隔震层以下结构能够达到预期抗震设防目标,并验证了PKPM简化计算方法的可行性。%The high-position seismic-isolated structure characteristic and the main parameters:frequency ratio and mass ratios are discussed which effect the isolated structure.The design method is introduced,such as the selection of the earthquake wave and its input methods,the anti-seismic aims of the isolation layer of structure and the structure above/below the layer,the rubber bearings equivalent stiffness calculation for response spectrum method.The high-position seismic-isolation structure was analyzed by ETABS program,in which simulates rubber bearings by unit Link,and was studied by the nonlinear time-history method and response spectrum method,and the equivalent shear stiffness of PKPM calculation method was also used.The structure above the isolation layer of the high-position seismic-isolation structure can reduce one degree to design.The isolation layer and the below structure can meet the expected anti-seismic goals.The correctness of the simplified calculation method of PKPM software is veified.

  16. Identification of novel Salmonella enterica Serovar Thyphimurium DT104-specific prophage and nonprophage chromosomal sequences among serovar Thyphimurium isolates by genomic subtractive hybridization

    NARCIS (Netherlands)

    Hermans, A.P.H.M.; Abee, T.; Zwietering, M.H.; Aarts, H.J.M.

    2005-01-01

    Genomic subtractive hybridization was performed between Salmonella enterica serovar Typhimurium LT2 and DT104 to search for novel Salmonella serovar Typhimurium DT104-specific sequences. The subtraction resulted mainly in the isolation of DNA fragments with sequence similarity to phages. Two fragmen

  17. Forecasting hysteresis behaviours of magnetorheological elastomer base isolator utilizing a hybrid model based on support vector regression and improved particle swarm optimization

    Science.gov (United States)

    Yu, Yang; Li, Yancheng; Li, Jianchun

    2015-03-01

    Due to its inherent hysteretic characteristics, the main challenge for the application of a magnetorheological elastomer- (MRE) based isolator is the exploitation of the accurate model, which could fully describe its unique behaviour. This paper proposes a nonparametric model for a MRE-based isolator based on support vector regression (SVR). The trained identification model is to forecast the shear force of the MRE-based isolator online; thus, the dynamic response from the MRE-based isolator can be well captured. In order to improve the forecast capacity of the model, a type of improved particle swarm optimization (IPSO) is employed to optimize the parameters in SVR. Eventually, the trained model is applied to the MRE-based isolator modelling with testing data. The results indicate that the proposed hybrid model has a better generalization capacity and better recognition accuracy than other conventional models, and it is an effective and suitable approach for forecasting the behaviours of a MRE-based isolator.

  18. Isolation and identification of genes expressed differentially in rice inflorescence meristem with suppression subtractive hybridization

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A subtracted cDNA library of rice (Oryza sativa L.) inflorescence meristem (IM) was constructed using the sup-pression subtractive hybridization (SSH) method. The cDNAs of the rice shoot apical meristem (SAM) were used as "driver" and inflorescence meristem (IM) as "tester" in the experiment, respectively. Forty of 250 randomly chosen cDNA clones were identified by differential screening, which were IM-specific or IM-highly expressed. Most of the rice IM cDNAs cloned by SSH appear to represent rare transcripts, 40% of which were derived from truly differentially ex-pressed genes. Of all the forty sequenced cDNA inserts, eleven contain the regions with 60%-90% identity to their homolog in GenBank, eighteen are expected to be new genes, only two correspond to published rice genes.

  19. Analysis on the seismic isolation and shock absorption and vibration control of building structure%建筑结构的隔震减振和振动控制分析

    Institute of Scientific and Technical Information of China (English)

    张宇彤

    2012-01-01

    分析了建筑结构隔震与消能减振的原理,结合实际应用情况,对建筑结构振动控制技术进行了研究,以解决建筑结构抗震设计中出现的一系列问题,确保建筑物安全。%The paper analyzes the seismic isolation and energy-saving and shock absorption principles of building structure.Combining with the actual application conditions,it studies the vibration control techniques of building structures,with a view to solve a series of problems occurring in seismic isolation design of building structures and to guarantee the building security.

  20. PERFORMANCE-BASED SEISMIC FRAGILITY ANALYSIS OF TALL HYBRID STRUCTURES%基于性能的高层混合结构地震易损性分析

    Institute of Scientific and Technical Information of China (English)

    何益斌; 李艳; 沈蒲生

    2013-01-01

    研究地震作用下高层钢框架-混凝土核心筒结构的易损性问题.通过基于性能的静力弹塑性分析,根据结构极限损伤状态定义了混合结构地震需求参数的四个性能水平限值.考虑地震动输入的不确定性,通过弹塑性动力时程分析获得结构地震响应,建立了两个地震需求参数与地震动强度指标之间的关系,结合性能水平限值提出能有效评估结构地震响应的易损性分析方法.最后对两个不同节点连接方式的高层混合结构进行了基于性能水平限值的地震易损性分析,绘制结构的地震易损性曲线,对结构抗震性能进行评估和对比分析.%The seismic fragility of high-rise steel frame-concrete core-wall structures was studied in this paper.Based on the performance-based fragility analysis method,four performance level limits of seismic demand parameters were proposed according to the ultimate damage states of the structures.Considering the randomness of input ground motions,the relationship between the two seismic demand parameters and ground motion intensity indicators was obtained through nonlinear dynamic time history analysis.Combined with the specified limits of performance levels,the vulnerability analysis method was put forward,by which the seismic structural response could be assessed effectively.Seismic fragility analysis was carried out for two high-rise hybrid structures with different connection forms,and fragility curves were obtained to assess and to compare the seismic performances of the two structures.

  1. A three-degree-of-freedom hybrid vibration isolation system using adaptive proportional control supported by passive weight support mechanism

    Science.gov (United States)

    Liu, Yun-Hui; Wu, Wei-Hao; Chu, Chih-Liang

    2013-10-01

    This paper presents a three-degree-of-freedom hybrid vibration isolation system integrated with an active sky-hook damper and a passive weight support mechanism for highly sensitive measurement equipment, e.g. atomic force microscopes, suffering from building vibration. Active sky-hook damper applies proportional controller incorporated with an adaptive filter to reduce the resonance of the passive weight support mechanism at nature frequency. The absolute vibration velocity signal acquired from an accelerator and being processed through an integrator is input to the controller as a feedback signal, and the controller output signal drives the voice coil actuator to produce a sky-hook damper force. The adaptive filter is used to compensate the phase error between the measuring input signal and the absolute vibration velocity. An analysis of this active vibration isolation system is presented, and model predictions are compared to experimental results. The results show that the system could effectively reduce transmissibility at resonance without the penalty of increased transmissibility at higher frequencies both in vertical and horizontal directions.

  2. Application of a DNA hybridization-hydrophobic-grid membrane filter method for detection and isolation of verotoxigenic escherichia coli.

    Science.gov (United States)

    Todd, E C; Szabo, R A; MacKenzie, J M; Martin, A; Rahn, K; Gyles, C; Gao, A; Alves, D; Yee, A J

    1999-11-01

    Verotoxigenic Escherichia coli (VTEC) strains were isolated from food and animal fecal samples by using PCR to screen for the presence of VTEC after broth enrichment and then filtering VTEC-positive cultures through hydrophobic-grid membrane filters (HGMFs) which were incubated on MacConkey agar. The filters were probed with a digoxigenin-labeled PCR product generated by amplification of a conserved verotoxin gene sequence. Replication of the growth on filters allowed probe-positive colonies to be picked. When ground beef samples were inoculated with VTEC strains, 100% of the strains were recovered, and the detection limit was 0.1 CFU per g. Similar results were obtained with seven types of artificially contaminated vegetables. A survey of 32 packages of vegetables and 23 samples of apple cider obtained at the retail level did not reveal the presence of VTEC. However, the intestinal fecal contents of a moose, 1 of 35 wild mammals and birds examined, contained E. coli O157:H7. The DNA hybridization-HGMF method was also used in a prevalence survey of 327 raw and 744 ready-to-eat products; VTEC strains were recovered from 4.9% of the raw products and 0.7% of the ready-to-eat products. No serotype O157:H7 strains were detected. This method is particularly suited for surveys in which low numbers of VTEC-positive samples are expected and isolates are required.

  3. Antibiotic and heavy metal resistance of Aeromonas hydrophila and Edwardsiella tarda isolated from red hybrid tilapia (Oreochromis spp. coinfected with motile aeromonas septicemia and edwardsiellosis

    Directory of Open Access Journals (Sweden)

    S. W. Lee

    2017-07-01

    Full Text Available Aim: The aim of this study is to identify antibiogram and heavy metal resistance pattern of Aeromonas hydrophila and Edwardsiella tarda isolated from red hybrid tilapia (Oreochromis spp. coinfected with motile aeromonas septicemia and edwardsiellosis in four commercial fish farms. Materials and Methods: A. hydrophila and E. tarda were isolated using glutamate starch phenol red and xylose lysine deoxycholate (Merck, Germany as a selective medium, respectively. All the suspected bacterial colonies were identified using conventional biochemical tests and commercial identification kit (BBL Crystal, USA. Susceptibility testing of present bacterial isolates to 16 types of antibiotics (nalidixic acid, oxolinic acid, compound sulfonamides, doxycycline, tetracycline, novobiocin, chloramphenicol, kanamycin, sulfamethoxazole, flumequine, erythromycin, ampicillin, spiramycin, oxytetracycline, amoxicillin, and fosfomycin and four types of heavy metals (mercury, chromium, copper, and zinc were carried out using disk diffusion and two-fold agar dilution method, respectively. Results: Three hundred isolates of A. hydrophila and E. tarda were successfully identified by biochemical tests. Antibiotic susceptibility testing results showed that 42.2% of the bacterial isolates were sensitive to compound sulfonamides, sulfamethoxazole, flumequine, oxytetracycline, doxycycline, and oxolinic acid. On the other hand, 41.6% of these isolates were resistant to novobiocin, ampicillin, spiramycin, and chloramphenicol, which resulted for multiple antibiotic resistance index values 0.416. Among tested heavy metals, bacterial isolates exhibited resistant pattern of Zn2+ > Cr6+ > Cu2+ > Hg2+. Conclusion: Results from this study indicated that A. hydrophila and E. tarda isolated from coinfected farmed red hybrid tilapia were multi-resistant to antibiotics and heavy metals. These resistant profiles could be useful information to fish farmers to avoid unnecessary use of

  4. Performance and dye-degrading bacteria isolation of a hybrid membrane process

    Energy Technology Data Exchange (ETDEWEB)

    You, Sheng-Jie, E-mail: sjyou@cycu.edu.tw [Department of Bioenvironmental Engineering and R and D Center for Membrane Technology, Chung Yuan Christian University, No. 200, Rd. Chung-Pei, Chungli 320, Taiwan (China); Teng, Jun-Yu, E-mail: nickprometheus@yahoo.com.tw [Department of Civil Engineering, Chung Yuan Christian University, Chungli 320, Taiwan (China)

    2009-12-15

    Textile dyeing wastewater contains harmful compounds, which are toxic to both marine organisms and human beings if it discharged into an aquatic environmental without suitable treatment. In this study, the wastewater containing the azo dye, Reactive Black 5 (RB5), was partially treated in an anaerobic sequencing batch reactor which was further treated either in an aerobic membrane bioreactors (AOMBR) or in combined aerobic membrane bioreactor/reverse osmosis (AOMBR/RO) process. The results showed that in the anaerobic sequencing batch reactor the RB5 dye was degraded to form aromatic amine intermediate metabolites, which were further mineralized in the AOMBR. It was also observed that although all effluents from the AOMBR and AOMBR/RO processes met the Taiwan EPA's effluent criteria, irrespective of which membranes were used in the aerobic tank, the effluent from the AOMBR/RO process met the criteria for reuse for toilet flushing, landscaping, irrigation, and cooling water purposes, where as the AOMBR effluent only met the criteria for cooling water due to incomplete color removal. Five anaerobic high dye-degrading bacteria were isolated, which were identified to be the same species of Lactococcus lactis by 16S rRNA sequencing. The L. lactis showed complete degradation of RB5 and further studies showed that it can also able to degrade Reactive Red 120 and Reactive Yellow 84 efficiently within 6 h.

  5. Isolation and Biosynthetic Analysis of Haliamide, a New PKS-NRPS Hybrid Metabolite from the Marine Myxobacterium Haliangium ochraceum

    Directory of Open Access Journals (Sweden)

    Yuwei Sun

    2016-01-01

    Full Text Available Myxobacteria of marine origin are rare and hard-to-culture microorganisms, but they genetically harbor high potential to produce novel antibiotics. An extensive investigation on the secondary metabolome of the unique marine myxobacterium Haliangium ochraceum SMP-2 led to the isolation of a new polyketide-nonribosomal peptide hybrid product, haliamide (1. Its structure was elucidated by spectroscopic analyses including NMR and HR-MS. Haliamide (1 showed cytotoxicity against HeLa-S3 cells with IC50 of 12 μM. Feeding experiments were performed to identify the biosynthetic building blocks of 1, revealing one benzoate, one alanine, two propionates, one acetate and one acetate-derived terminal methylene. The biosynthetic gene cluster of haliamide (hla, 21.7 kbp was characterized through the genome mining of the producer, allowing us to establish a model for the haliamide biosynthesis. The sulfotransferase (ST-thioesterase (TE domains encoded in hlaB appears to be responsible for the terminal alkene formation via decarboxylation.

  6. Identification of Markers for Helicobacter pylori Strains Isolated from Children with Peptic Ulcer Disease by Suppressive Subtractive Hybridization

    Science.gov (United States)

    Oleastro, Mónica; Monteiro, Lurdes; Lehours, Philippe; Mégraud, Francis; Ménard, Armelle

    2006-01-01

    Peptic ulcer disease (PUD) occurs after a long-term Helicobacter pylori infection. However, the disease can develop earlier, and rare cases have been observed in children, suggesting that these H. pylori strains may be more virulent. We used suppressive subtractive hybridization for comparative genomics between H. pylori strains isolated from a 5-year-old child with duodenal ulcer and from a sex- and age-matched child with gastritis only. The prevalence of the 30 tester-specific subtracted sequences was determined on a collection of H. pylori strains from children (15 ulcers and 30 gastritis) and from adults (46 ulcers and 44 gastritis). Two of these sequences, jhp0562 (80.0% versus 33.3%, P = 0.008) and jhp0870 (80.0% versus 36.7%, P = 0.015), were highly associated with PUD in children and a third sequence, jhp0828, was less associated (40.0% versus 10.0%, P = 0.048). Among adult strains, none of the 30 sequences was associated with PUD. However, both jhp0562 and jhp0870 were less prevalent in adenocarcinoma strains than in PUD strains from children and adults, the difference being statistically significant for jhp0870. In conclusion, two H. pylori genes were identified as being strongly associated with PUD in children, and their putative roles as an outer membrane protein for jhp0870 and in lipopolysaccharide biosynthesis for jhp0562, suggest that they may be novel virulence factors of H. pylori. PMID:16790780

  7. Specific Detection of Clavibacter michiganensis subsp. sepedonicus by Amplification of Three Unique DNA Sequences Isolated by Subtraction Hybridization.

    Science.gov (United States)

    Mills, D; Russell, B W; Hanus, J W

    1997-08-01

    ABSTRACT Three single-copy, unique DNA fragments, designated Cms50, Cms72, and Cms85, were isolated from strain CS3 of Clavibacter michiganensis subsp. sepedonicus by subtraction hybridization using driver DNA from C. michiganensis subsp. insidiosus, C. michiganensis subsp. michiganensis, and Rhodococcus facians. Radio-labeled probes made of these fragments and used in Southern blot analysis revealed each to be absolutely specific to all North American C. michiganensis subsp. sepedonicus strains tested, including plasmidless and nonmucoid strains. The probes have no homology with genomic DNA from related C. michiganensis subspecies insidiosus, michiganensis, and tessellarius, nor with DNA from 11 additional bacterial species and three unidentified strains, some of which have been previously reported to display cross-reactivity with C. michiganensis subsp. sepedonicus-specific antisera. The three fragments shared no homology, and they appeared to be separated from each other by at least 20 kbp in the CS3 genome. Internal primer sets permitted amplification of each fragment by the polymerase chain reaction (PCR) only from C. michiganensis subsp. sepedonicus DNA. In a PCR-based sensitivity assay using a primer set that amplifies Cms85, the lowest level of detection of C. michiganensis subsp. sepedonicus was 100 CFU per milliliter when cells were added to potato core fluid. Erroneous results that may arise from PCR artifacts and mutational events are, therefore, minimized by the redundancy of the primer sets, and the products should be verifiable with unique capture probes in sequence-based detection systems.

  8. The Solution to Seismic Isolation of Frame Structure%框架结构基础隔震方案的选择

    Institute of Scientific and Technical Information of China (English)

    杨利国; 李涛峰

    2015-01-01

    the base isolation of frame structure design of a shopping mall planned to adopt ordinary rubber bearing or lead rubber bearing, and had a non-linear time history analysis on these two solutions for inputting EI-Centro wave by SAP2000 software of ifnite element analysis. The results showed that the structure of laminated ordinary rubber bearings enjoyed higher increased natural vibration period in the front three vibration modes than that of the solution of lead rubber bearing; besides, the accelerated speed caused by earthquake on each floor was slightly less than that of the lead rubber bearing. Therefore, it is more feasible to adopt the laminated ordinary rubber bearings after comprehensively taken seismic isolation effect, costs, construction and other factors into consideration.%某框架结构商场设计采用基础隔震,拟选用普通橡胶支座或铅芯橡胶支座,运用SAP2000有限元分析软件对两种隔震方案输入EI-Centro波进行非线性时程分析。结果表明,采用普通层叠橡胶支座的方案结构在前3个振型中增加的自振周期高于铅芯橡胶支座方案,且由地震引起各楼层的加速度略小于铅芯橡胶支座方案;采用铅芯橡胶支座方案各楼层的层间最大位移略小于普通层叠橡胶支座方案。综合考虑隔震效果、造价和施工等因素,该工程选用普通层叠橡胶支座方案更为合适。

  9. Non-instrumented DNA isolation, amplification and microarray-based hybridization for a rapid on-site detection of devastating Phytophthora kernoviae.

    Science.gov (United States)

    Schwenkbier, Lydia; Pollok, Sibyll; Rudloff, Anne; Sailer, Sebastian; Cialla-May, Dana; Weber, Karina; Popp, Jürgen

    2015-10-07

    A rapid and simple instrument-free detection system was developed for the identification of the plant pathogen Phytophthora kernoviae (P. kernoviae). The on-site operable analysis steps include magnetic particle based DNA isolation, helicase-dependent amplification (HDA) and chip-based DNA hybridization. The isothermal approach enabled the convenient amplification of the yeast GTP-binding protein (Ypt1) target gene in a miniaturized HDA-zeolite-heater (HZH) by an exothermic reaction. The amplicon detection on the chip was performed under room temperature conditions – either by successive hybridization and enzyme binding or by a combined step. A positive signal is displayed by enzymatically generated silver nanoparticle deposits, which serve as robust endpoint signals allowing an immediate visual readout. The hybridization assay enabled the reliable detection of 10 pg μL(-1) target DNA. This is the first report of an entirely electricity-free, field applicable detection approach for devastating Phytophthora species, exemplarily shown for P. kernoviae.

  10. speciation through asexuality in fish: postzygotic reproductive isolation may be completed in spite of fertility of hybrids

    Directory of Open Access Journals (Sweden)

    Karel Janko

    2015-12-01

    Altogether, it appears that initiation of hybrid asexuality and the completion of speciation process through formation of postRIMs are interconnected phenomena. Both processes are linked to the genetic divergence of hybridizing taxa: initially, hybridization between little diverged species leads to recombinant and fertile hybrids allowing intensive gene flow. As the hybridizing taxa continue to diverge, clonally reproducing hybrid females and sterile males become dominant and the gene flow ceases. The speciation may therefore be completed through asexuality of hybrids The work was supported by grant no. 13-12580S provided by the Czech Science Foundation (www.gacr.cz. Further support was provided by the Academy of Sciences of the Czech Republic (www.cas.cz by the grant no. RVO 67985904

  11. Analysis and Research on the Seismic Performance of Adobe Structure

    Institute of Scientific and Technical Information of China (English)

    Yun Xu

    2015-01-01

    According to the bearing structure, building materials and process, this paper adobe housing will be divided into Adobe bearing wall, brick wall, hybrid bearing housing and bearing timber frame house. Research shows that, different types of housing distribution has regional and age characteristics, seismic performance is different, but there are different seismic safety problems; in order to improve the seismic capacity of rural houses, we need to accelerate the implementation of rural residential earthquake safety project, speed up the reconstruction of the demolition reconstruction and seismic reinforcement work, to carry out research on seismic technology houses, promote rural seismic residential.

  12. Homoploid hybrid expectations

    Science.gov (United States)

    Homoploid hybrid speciation occurs when a stable, fertile, and reproductively isolated lineage results from hybridization between two distinct species without a change in ploidy level. Reproductive isolation between a homoploid hybrid species and its parents is generally attained via chromosomal re...

  13. On the isolation of elemental carbon for micro-molar 14C accelerator mass spectrometry; evaluation of alternative isolation procedures, and accuracy assurance using a hybrid isotopic particulate carbon reference material

    Directory of Open Access Journals (Sweden)

    L. A. Currie

    2005-05-01

    Full Text Available The primary objective of the research reported here has been the development of an hybrid reference material (RM to serve as a test of accuracy for elemental carbon (EC isotopic (14C speciation measurements. Such measurements are critically important for the quantitative apportionment of fossil and biomass sources of ''soot'' (EC, the tracer of fire that has profound effects on health, atmospheric visibility, and climate. Previous studies of 14C-EC measurement quality, carried out with NIST SRM 1649a (Urban Dust, showed a range of results, but since the ''truth'' was not known for this natural matrix RM, one had to rely on isotopic-chemical consistency evidence (14C in PAH, EC of measurement validity (Currie et al., 2002. Components of the new Hybrid RM (DiesApple, however, have known 14C and EC composition, and they are nearly orthogonal (isotopically and chemically. NIST SRM 2975 (Forklift Diesel Soot has little or no 14C, and its major compositional component is EC. SRM 1515 (Apple Leaves has the 14C content of biomass-C, and it has little or no EC. Thus, the hybrid RM can serve as an absolute isotopic test for the absence of EC-mimicking pyrolysis-C from SRM 1515 in the EC isolate of the hybrid RM, together with testing for conservation of its dominant soot fraction through the isolation procedure.

  14. Heat-mechanics interaction behavior of lead rubber bearings for seismic base isolation under large and cyclic lateral deformation. Part 1. Dynamic loading test of LRB and development of analytical method

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, Akihiro; Takenaka, Yasuo; Takaoka, Eiji; Hikita, Makiko; Hyodo, Yo (Kajima Corporation, Tokyo (Japan)), e-mail: kondo-akihiro@kajima.com; Kitamura, Haruyuki (Tokyo Univ. of Science, Chiba (Japan)), e-mail: kita-h@rs.noda.tus.ac.jp

    2009-07-01

    When base-isolated buildings are subjected to long-period strong earthquakes emanating from oceanic trenches, base-isolation devices such as Lead Rubber Bearings (LRB) can be subjected to larger and more cyclic deformations than anticipated in structural design. In an LRB, seismic input energy is absorbed as hysteresis energy of a lead plug, and finally transformed into thermal energy. The resulting large and multiple cyclic deformations of the LRB generate a large amount of heat, causing high temperatures of the lead plug. The resulting deterioration of damping characteristics which encompasses a complex thermal and mechanical phenomenon provides a serious concern for the base-isolated building responses. However, there is insufficient experimental data on this phenomenon, and no analytical method for evaluation of heat-mechanics interaction behavior has been derived. The paper describes experimental results and derivation of analytical methods for determining the heat-mechanics interaction of the LRB under a large and cyclic lateral deformation

  15. 腾冲市中医医院门诊楼采用隔震技术的响应分析%Response Analysis of Seismic Isolation Technique Used in the Outpatient Building of Tengchong County Hospital of Traditional Chinese Medicine

    Institute of Scientific and Technical Information of China (English)

    李波生; 汪小锋

    2016-01-01

    Adopting isolation technology can effectively reduce the earthquake effect of the upper structure level, reduce the earthquake damage of structure and non structure components, improve the building and internal facilities and personnel security in the earthquake. In order to study the isolation effect after setting up laminated rubber isolation bearings on the structure, this project uses a large finite element software Etabs to build seismic Isolation and non isolation structure model, and compares the seismic response of the structure before and after the seismic Isolation. Results show that after using isolation technology, the seismic response of the structure decreased significantly, and obtained good effect of seismic isolation. This can provide certain reference for the application of seismic isolation technology in the engineering practice in the future.%采用隔震技术可以有效地减小上部结构水平地震作用效应,减轻结构和非结构构件的地震破坏,提高建筑物及内部设施和人员在地震中的安全性。为了研究结构设置叠层橡胶隔震支座后的隔震效果,本工程使用大型有限元软件Etabs建立隔震与非隔震结构模型,对结构在隔震前后的地震反应进行对比分析。结果表明:采用隔震技术后,结构的地震反应明显减弱,取得较好的隔震效果。为隔震技术在以后的工程实际中的应用提供一定的参考价值。

  16. Molecular characterization of enterohemorrhagic Escherichia coli hemolysin gene (EHEC-hlyA)-harboring isolates from cattle reveals a diverse origin and hybrid diarrheagenic strains.

    Science.gov (United States)

    Askari Badouei, Mahdi; Morabito, Stefano; Najafifar, Arash; Mazandarani, Emad

    2016-04-01

    In the present study we investigated the occurrence of Escherichia coli strains harboring the gene encoding enterohemorrhagic E. coli hemolysin (EHEC-HlyA) in cattle and the association of this gene with various diarrheagenic E. coli (DEC) pathotypes. First, the bovine E. coli isolates were screened for EHEC-hlyA gene by PCR, and then they were characterized for the phylogenetic groups and the presence of the major virulence genes of different DEC pathotypes. In total, 25 virulence gene profiles were observed in 54 EHEC-hlyA+ isolates that reflect a considerable heterogeneity. The EHEC-hlyA+ strains were mostly associated with EHEC (72%), while only 7.4% were enteropathogenic E. coli (EPEC). We also showed the presence of estA gene of enterotoxigenic E. coli (ETEC) in 6 isolates (11.1%). Interestingly, two of the estA+ strains showed hybrid pathotypes with one carrying eae/estA (EPEC/ETEC), and the other one stx2/astA/estA (EHEC/ETEC). None of the isolates were related to enteroaggregative E. coli (EAggEC), enteroinvasive E. coli (EIEC), and necrotoxigenic E. coli (NTEC). The EHEC-plasmid encoded genes occurred in seven different combinations with EHEC-hlyA/saa/subA/espP being the most prevalent (46.3%). All stx-/eae+ strains carried O island 57 (OI-57) molecular marker(s) that may indicate these to be the progenitors of EHEC or strains losing stx. The most prevalent phylogroup was B1 (61.1%), but the most heterogeneous strains including the hybrid strains belonged to A phylogroup. Overall, our results indicate that cattle EHEC-hlyA encoding E. coli isolates consist of diverse diarrheagenic strains with the possible existence of hybrid pathotypes. Future studies are required to clarify the evolutionary aspects and clinical significance of these strains in humans and domestic animals.

  17. Seismic Creep

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Seismic creep is the constant or periodic movement on a fault as contrasted with the sudden erupture associated with an earthquake. It is a usually slow deformation...

  18. Seismic seiches

    Science.gov (United States)

    McGarr, Arthur; Gupta, Harsh K.

    2011-01-01

    Seismic seiche is a term first used by Kvale (1955) to discuss oscillations of lake levels in Norway and England caused by the Assam earthquake of August 15, 1950. This definition has since been generalized to apply to standing waves set up in closed, or partially closed, bodies of water including rivers, shipping channels, lakes, swimming pools and tanks due to the passage of seismic waves from an earthquake.

  19. Identification and quantification of Bifidobacterium species isolated from food with genus-specific 16S rRNA-targeted probes by colony hybridization and PCR.

    Science.gov (United States)

    Kaufmann, P; Pfefferkorn, A; Teuber, M; Meile, L

    1997-01-01

    A Bifidobacterium genus-specific target sequence in the V9 variable region of the 16S rRNA has been elaborated and was used to develop a hybridization probe. The specificity of this probe, named lm3 (5'-CGGGTGCTI*CCCACTTTCATG-3'), was used to identify all known type strains and distinguish them from other bacteria. All of the 30 type strains of Bifidobacterium which are available at the German culture collection Deutsche Sammlung von Mikroorganismen und Zellkulturen, 6 commercially available production strains, and 34 closely related relevant strains (as negative controls) were tested. All tested bifidobacteria showed distinct positive signals by colony hybridization, whereas all negative controls showed no distinct dots except Gardnerella vaginalis DSM4944 and Propionibacterium freudenreichii subsp. shermanii DSM4902, which gave slight signals. Furthermore, we established a method for isolation and identification of bifidobacteria from food by using a PCR assay without prior isolation of DNA but breaking the cells with proteinase K. By this method, all Bifidobacterium strains lead to a DNA product of the expected size. We also established a quick assay to quantitatively measure Bifidobacterium counts in food and feces by dilution plating and colony hybridization. We were able to demonstrate that 2.1 x 10(6) to 2.3 x 10(7) colonies/g of sour milk containing bifidobacteria hybridized with the specific nucleotide probe. With these two methods, genus-specific colony hybridization and genus-specific PCR, it is now possible to readily and accurately detect any bifidobacteria in food and fecal samples and to discriminate between them and members of other genera. PMID:9097423

  20. 某多层“自定义”钢结构住宅隔震设计%A SEISMIC ISOLATION DESIGN FOR A MULTI-STORY CUSTOM STEEL STRUCTURE RESIDENCE

    Institute of Scientific and Technical Information of China (English)

    赵风华; 杨俊

    2014-01-01

    Adopting the common and base isolation and non-islotion systems, comparative analysis of structure ’ s seismic performance was conducted on a multi-storey custom steel structure residence .El centro wave , Tianjin wave and an artificial earthquake wave are the seismic input .A two-degree of freedom Bouc-Wen hysteretic model was used to simplify the vibration isolation structure when analyzing the ductility demands .A brief analysis of the life cycle cost of this residence was also worked out .The results demonstrate that the gradually matured seismic isolated technology can be applied to steel structures as well .With the satisfaction of required bearing capacity , the seismic isolation layer has effectively controlled the vibration of superstructure , the structural response to earthquake has been effectively reduced and the interstorey acceleration response has also been greatly reduced , the safety of this structure has been guaranteed .Which meets the higher requirements towards the comforts of residence structures .%结合某多层“自定义”钢结构住宅工程,采用基础隔震体系及非隔震体系,对结构抗震性能进行综合对比分析。分别以El centro波、天津波(南北向)、合成人工波为地震动输入求解结构的动力响应;对结构延性需求进行分析,用两个自由度的Bouc-Wen滞回模型进行非线性动力分析,对其生命周期成本进行简要分析。结果表明:渐于成熟的隔震技术同样适用于钢结构体系。该钢结构住宅考虑隔震设计后,在满足承载力要求的前提下,隔震层有效控制了上部结构振动,结构地震响应有效降低,层间加速度反应大大减小,建筑物的安全性能得到保证,满足了住宅结构对舒适性的更高要求。

  1. An Effectiveness Analysis on Hybrid Control System of Tuned Mass Damper-base Isolation under Near-fault Pulse-like Ground Motion%近场脉冲型地震动作用下TMD-基础隔震混合控制结构的减震效果分析

    Institute of Scientific and Technical Information of China (English)

    李慧; 王亚楠; 杜永峰

    2013-01-01

    近场地震动具有很高的加速度峰值和长周期的速度脉冲,因此能够对结构造成严重的破坏.基础隔震是一种有效的减震技术,然而这种单一的减震手段在低频具有很高能量的近场脉冲型地震动作用下已不能确保结构的安全,必须寻求新的减震策略.本文将速度脉冲模型与随机地震地面运动模型联合来生成近场脉冲型地震动,并以此作为激励,用MATLAB对近场脉冲型地震动作用下TMD-基础隔震混合控制结构及独立基础隔震结构的地震响应进行求解,比较研究该混合控制结构的减震效果.结果表明该混合控制方式可以有效地控制结构的位移,而对加速度的控制效果不明显.%Near-fault ground motions can cause severe damage to structures because of its high peak accelerations and macrocyclic velocity pulses.In the last two decades,the seismic isolation technique,which was proved to be very effective for the seismic protection of new constructions and the seismic retrofitting of existing ones,had been applied for buildings,bridges,industrial facilities,and structures of historical value as well.As a consequence,design guidelines for seismically isolated structures have been developed in many countries with a high seismic hazard.The insertion of an isolation system at the base of a building structure allows the horizontal seismic loads to be reduced through a decoupling of the structure motion from that of the soil; moreover,the superstructure behaves like a fixed or base isolated structure along the vertical direction,depending on the value,respectively very high or very low,of the ratio between the vertical stiffness of the isolator and the horizontal one.Base isolation technique,taken as an effective method to control structure's vibration that is induced by earthquake ground motions,has been widely accepted,however,only such an approach can not ensure structure's safety under near-fault pulse like ground motions

  2. Molecular characterization of a cellulose synthase gene (AaxmCesA1) isolated from an Acacia auriculiformis x Acacia mangium hybrid.

    Science.gov (United States)

    Yong, Seok Yien Christina; Wickneswari, Ratnam

    2013-01-01

    Cellulose is the major component of plant cell walls, providing mechanical strength to the structural framework of plants. In association with lignin, hemicellulose, protein and pectin, cellulose forms the strong yet flexible bio-composite tissue of wood. Wood formation is an essential biological process and is of significant importance to the cellulosic private sector industry. Cellulose synthase genes encode the catalytic subunits of a large protein complex responsible for the biogenesis of cellulose in higher plants. The hybrid Acacia auriculiformis x Acacia mangium represents an important source of tree cellulose for forest-based product manufacturing, with enormous economic potential. In this work, we isolate the first cellulose synthase gene, designated AaxmCesA1, from this species. The isolated full-length AaxmCesA1 cDNA encodes a polypeptide of 1,064 amino acids. Sequence analyses revealed that AaxmCesA1 cDNA possesses the key motif characteristics of a CesA protein. AaxmCesA1 shares more than 75 % amino acid sequence identity with CesA proteins from other plant species. Subsequently, the full-length AaxmCesA1 gene of 7,389 bp with partial regulatory and 13 intron regions was also isolated. Relative gene expression analysis by quantitative PCR in different tissues of the Acacia hybrid, suggests the involvement of the AaxmCesA1 gene in primary cell wall synthesis of rapidly dividing young root cells. Similarity analyses using Blast algorithms also suggests a role in primary cell wall deposition in the Acacia hybrid. Southern analysis predicts that AaxmCesA1 is a member of a multigene family with at least two isoforms in the genome of the Acacia hybrid.

  3. 高层隔震结构非平稳随机地震响应与动力可靠度分析%Non-stationary random response and dynamic reliability of high-rise seismic isolated structure

    Institute of Scientific and Technical Information of China (English)

    孙臻; 王曙光; 王赟玉; 刘伟庆

    2011-01-01

    考虑地震动的非平稳特性,运用虚拟激励法对高层隔震结构在非平稳激励下的随机地震响应进行研究。采用Bouc-Wen模型与刚度退化的Bouc-Wen模型分别模拟隔震层与上部楼层的滞变特性,建立高层隔震结构的非线性化运动方程。运用精细积分法对每一时刻的响应进行求解,得到高层隔震结构在非平稳地震激励下各楼层响应的时变方差。基于首次穿越准则,研究非平稳随机地震激励下各楼层与结构整体的可靠度。运用上述理论,分析某高层基础隔震结构在8度与9度罕遇地震作用下的随机地震响应,隔震后上部结构各楼层层间位移方差较非隔震结构大幅减小。研究表明:结构的位移响应呈现强烈的非平稳性,且具有明显的时滞现象;高层隔震结构在强震作用下各楼层可靠度较非隔震结构有很大的提高,说明高层隔震结构具有足够的安全性。运用可靠度理论进行分析亦能发现结构的薄弱部位,该方法对结构的性能设计与性态控制具有指导意义。%Considering the non-stationary characteristics of the earthquake ground motion,the random seismic response of high-rise seismic isolated building is investigated using pseudo excitation method.The Bouc-Wen model and the stiffness degradation of Bouc-Wen model are used to simulate the hysteresis of the isolation layer and the upper structure,respectively.The nonlinear motion equation of the high-rise seismic isolation structure is established.And the system response for each moment is solved by precise integration method.The time-history response of each floor under non-stationary earthquake excitation is got.Based on the first passage criterion,the reliability index of each floor and the whole structure are calculated.Those theories are used to analyze random earthquake response of a high-rise base isolated structure under 8 and 9 degree rare earthquakes.The time-history variance of story

  4. Isolation

    DEFF Research Database (Denmark)

    Agerholm, Frank Juul

    2011-01-01

    Næringsstoffet har i dette nummer sat fokus på ”velvære i vinterkulden”, ”indendørsaktiviteter” og ”fedtafgift”. I klummen vises det, at disse tre fokusområder, der for en umiddelbar betragtning måske nok synes noget uensartede, falder sammen i ét tema: Isolation!......Næringsstoffet har i dette nummer sat fokus på ”velvære i vinterkulden”, ”indendørsaktiviteter” og ”fedtafgift”. I klummen vises det, at disse tre fokusområder, der for en umiddelbar betragtning måske nok synes noget uensartede, falder sammen i ét tema: Isolation!...

  5. Mobile seismic exploration

    Science.gov (United States)

    Dräbenstedt, A.; Cao, X.; Polom, U.; Pätzold, F.; Zeller, T.; Hecker, P.; Seyfried, V.; Rembe, C.

    2016-06-01

    Laser-Doppler-Vibrometry (LDV) is an established technique to measure vibrations in technical systems with picometer vibration-amplitude resolution. Especially good sensitivity and resolution can be achieved at an infrared wavelength of 1550 nm. High-resolution vibration measurements are possible over more than 100 m distance. This advancement of the LDV technique enables new applications. The detection of seismic waves is an application which has not been investigated so far because seismic waves outside laboratory scales are usually analyzed at low frequencies between approximately 1 Hz and 250 Hz and require velocity resolutions in the range below 1 nm/s/√Hz. Thermal displacements and air turbulence have critical influences to LDV measurements at this low-frequency range leading to noise levels of several 100 nm/√Hz. Commonly seismic waves are measured with highly sensitive inertial sensors (geophones or Micro Electro-Mechanical Sensors (MEMS)). Approaching a laser geophone based on LDV technique is the topic of this paper. We have assembled an actively vibration-isolated optical table in a minivan which provides a hole in its underbody. The laser-beam of an infrared LDV assembled on the optical table impinges the ground below the car through the hole. A reference geophone has detected remaining vibrations on the table. We present the results from the first successful experimental demonstration of contactless detection of seismic waves from a movable vehicle with a LDV as laser geophone.

  6. Mobile seismic exploration

    Energy Technology Data Exchange (ETDEWEB)

    Dräbenstedt, A., E-mail: a.draebenstedt@polytec.de, E-mail: rembe@iei.tu-clausthal.de, E-mail: ulrich.polom@liag-hannover.de; Seyfried, V. [Research & Development, Polytec GmbH, Waldbronn (Germany); Cao, X.; Rembe, C., E-mail: a.draebenstedt@polytec.de, E-mail: rembe@iei.tu-clausthal.de, E-mail: ulrich.polom@liag-hannover.de [Institute of Electrical Information Technology, TU Clausthal, Clausthal-Zellerfeld (Germany); Polom, U., E-mail: a.draebenstedt@polytec.de, E-mail: rembe@iei.tu-clausthal.de, E-mail: ulrich.polom@liag-hannover.de [Leibniz Institute of Applied Geophysics, Hannover (Germany); Pätzold, F.; Hecker, P. [Institute of Flight Guidance, TU Braunschweig, Braunschweig (Germany); Zeller, T. [Clausthaler Umwelttechnik Institut CUTEC, Clausthal-Zellerfeld (Germany)

    2016-06-28

    Laser-Doppler-Vibrometry (LDV) is an established technique to measure vibrations in technical systems with picometer vibration-amplitude resolution. Especially good sensitivity and resolution can be achieved at an infrared wavelength of 1550 nm. High-resolution vibration measurements are possible over more than 100 m distance. This advancement of the LDV technique enables new applications. The detection of seismic waves is an application which has not been investigated so far because seismic waves outside laboratory scales are usually analyzed at low frequencies between approximately 1 Hz and 250 Hz and require velocity resolutions in the range below 1 nm/s/√Hz. Thermal displacements and air turbulence have critical influences to LDV measurements at this low-frequency range leading to noise levels of several 100 nm/√Hz. Commonly seismic waves are measured with highly sensitive inertial sensors (geophones or Micro Electro-Mechanical Sensors (MEMS)). Approaching a laser geophone based on LDV technique is the topic of this paper. We have assembled an actively vibration-isolated optical table in a minivan which provides a hole in its underbody. The laser-beam of an infrared LDV assembled on the optical table impinges the ground below the car through the hole. A reference geophone has detected remaining vibrations on the table. We present the results from the first successful experimental demonstration of contactless detection of seismic waves from a movable vehicle with a LDV as laser geophone.

  7. Isolation of probiotic bacteria from the hybrid South American catfish Pseudoplatystoma reticulatum × Pseudoplatystoma corruscans (Siluriformes: Pimelodidae: A haematological approach

    Directory of Open Access Journals (Sweden)

    José Luiz Pedreira Mouriño

    2016-05-01

    Full Text Available This study investigated bacterial strains with probiotic potential isolated from the middle portion of healthy hybrid surubim catfish foregut (Pseudoplatystoma reticulatum female × P. corruscans male. Twenty surubims weighing 1.5 ± 0.3 kg were used for bacterial isolation. In total, 41 strains of bacteria were selected in vitro. Ten strains had inhibition zones >10 mm against Aeromonas hydrophila. Five of those strains presented inhibition zones > 9 mm against other pathogenic bacteria and reached concentrations greater than 105 CFU mL−1 in tubes containing de Man, Rogosa and Sharpe (MRS medium. In particular, Weissella cibaria (P36 reached 106 CFU mL−1 in MRS and was able to reduce the pH of the medium to 3.85. In the in vivo intestinal colonization studies, 72 healthy hybrid surubims were fed with a commercial diet supplemented with probiotic W. cibaria for 15 days. Changes in gut community composition were then analyzed, and probiotic profile of W. cibaria was determined molecularly by amplification of rRNA 16S gene was performed using PCR. Compared to control fish, W. cibaria-supplemented fish showed an increase in RBC. These results show the efficacy of our haematological approach to probiotic screening in hybrid sorubim.

  8. 'Tropicalisation' of feed-in tariffs. A custom-made support scheme for hybrid PV/diesel systems in isolated regions

    Energy Technology Data Exchange (ETDEWEB)

    Solano-Peralta, Mauricio; Van Sark, Wilfried G.J.H.M. [Department of Science, Technology and Society, Copernicus Institute for Sustainable Development and Innovation, Utrecht University, Heidelberglaan 2, 3584 CS Utrecht (Netherlands); Moner-Girona, Magda [Renewable Energies Unit, Institute for Energy, European Commission-Joint Research Centre, Via E. Fermi 2749 - TP 450 I-21027 Ispra (Italy); Vallve, Xavier [Trama Tecnoambiental, Ripolles 46, 08026 Barcelona (Spain)

    2009-12-15

    The interest and actions towards introducing renewables for off-grid regions has increased due to their ostensible cost-effectiveness, eco-friendliness and quality services provided. Nevertheless, in many isolated areas diesel generators appear as a common option, confirming that there is a need for financial support mechanisms that aid the introduction of renewables due to their higher initial investment costs. This paper proposes a so-called 'tropicalisation' of the Feed-in Tariff scheme to promote the introduction of hybrid systems in isolated communities based on the idea of awarding for each kWh produced by renewable energies a premium value during a guaranteed period of time. The proposed Renewable Energy Premium Tariff (RPT) scheme is an alternative mechanism to the usual initial investment donation for off-grid energy development projects by recognising the production of renewable electricity and opting for a long-term sustainability of the projects. Ecuador presents ideal conditions to study the introduction of such a 'tropicalised' scheme since a Feed-in Law including off-grid projects was established in 2002 and since there are governmental and local efforts for the introduction of renewable hybrids in isolated regions. Modelling of the introduction of photovoltaics (PVs) into diesel systems for several mini-grids located in isolated regions of Ecuador has been performed, and included a detailed financial analysis for optimisation of RPT values and a comparison with existing stand-alone diesel systems. The results show the cost-effectiveness of PV/diesel hybrids over diesel gensets, taking into account present and future diesel prices. To obtain long-term sustainability of the project, the RPT values are set at 0.70-1.20$kWh covering the operability of the whole system for 20 years, where the renewable fraction should have the largest share in the hybrid system. The proposed mechanism is expected to aid the introduction of renewable

  9. Seismic Studies

    Energy Technology Data Exchange (ETDEWEB)

    R. Quittmeyer

    2006-09-25

    This technical work plan (TWP) describes the efforts to develop and confirm seismic ground motion inputs used for preclosure design and probabilistic safety 'analyses and to assess the postclosure performance of a repository at Yucca Mountain, Nevada. As part of the effort to develop seismic inputs, the TWP covers testing and analyses that provide the technical basis for inputs to the seismic ground-motion site-response model. The TWP also addresses preparation of a seismic methodology report for submission to the U.S. Nuclear Regulatory Commission (NRC). The activities discussed in this TWP are planned for fiscal years (FY) 2006 through 2008. Some of the work enhances the technical basis for previously developed seismic inputs and reduces uncertainties and conservatism used in previous analyses and modeling. These activities support the defense of a license application. Other activities provide new results that will support development of the preclosure, safety case; these results directly support and will be included in the license application. Table 1 indicates which activities support the license application and which support licensing defense. The activities are listed in Section 1.2; the methods and approaches used to implement them are discussed in more detail in Section 2.2. Technical and performance objectives of this work scope are: (1) For annual ground motion exceedance probabilities appropriate for preclosure design analyses, provide site-specific seismic design acceleration response spectra for a range of damping values; strain-compatible soil properties; peak motions, strains, and curvatures as a function of depth; and time histories (acceleration, velocity, and displacement). Provide seismic design inputs for the waste emplacement level and for surface sites. Results should be consistent with the probabilistic seismic hazard analysis (PSHA) for Yucca Mountain and reflect, as appropriate, available knowledge on the limits to extreme ground

  10. 层间隔震技术在某地铁上盖高层建筑中的应用%Story isolation of seismic technology in a subway cover the application of the high-rise building

    Institute of Scientific and Technical Information of China (English)

    朱冬飞; 习志强

    2015-01-01

    结合某工程实例,对层间隔震技术在高层建筑中的应用做了详细阐述。采用软件PKPM和ETABS分别建立模型,并运用ETABS对该结构进行动力时程分析。通过对隔震结构与非隔震结构的计算结果进行分析可知,采用隔震技术后,剪力和倾覆力矩以及层间位移角显著减小,降低了地震对结构的反应。从而进一步为层间隔震技术在类似的建筑中的广泛应用提供了一个良好的实例。%Based on engineering, the application of story isolation technology in the high-rise building is presented. The model made by PKPM and ETABS structure analysis software, The model time history analysis of the structure is investigated by ETABS. By isolation and the isolation of the structure of the calculation result is analyzed. After using story isolation technology, shear force and overturning moment and interlayer displacement angle is greatly reduced. Thus significantly reduce the seismic response of the structure .Further, the accuracy of calculation analysis and the security of story isolation structure are verified.

  11. Peptide Nucleic Acid-Fluorescence In Situ Hybridization for Detection of Staphylococci From Endophthalmitis Isolates: A Proof-of-Concept Study.

    Science.gov (United States)

    Patel, Nimesh; Miller, Darlene; Relhan, Nidhi; Flynn, Harry W

    2017-08-01

    Rapid identification of pathogens causing endophthalmitis may improve treatment outcomes through early administration of species-specific medication. The current study reports a new molecular application of peptide nucleic acid-fluorescence in situ hybridization (PNA-FISH) with Staphylococcus-specific molecular PNA probes for the potential rapid detection of common pathogens causing endophthalmitis. An experimental study was designed to evaluate the proof of concept at the microbiology laboratory of the Bascom Palmer Eye Institute. Stored culture-positive staphylococci endophthalmitis isolates obtained from prior vitreous samples (n = 15), along with broth as negative controls (n = 5) were used. Inoculum was prepared to a final concentration of 1 × 105 colony-forming units/mL to ensure that the isolates were viable. Smears of samples were fixed and hybridized using QuickFISH protocol with probes for Staphylococcus. With PNA-FISH technique, Staphylococcus aureus was identified in 9 of 10 samples and coagulase-negative staphylococci were identified in 10 of 10 samples. Detection time was 20 minutes. This study serves a proof of concept using a new microbial detection system with FISH probes, and may have the potential for clinical use in the rapid and accurate identification of isolates from patients with endophthalmitis.

  12. New high-order, semi-implicit Hybridized Discontinuous Galerkin - Spectral Element Method (HDG-SEM) for simulation of complex wave propagation involving coupling between seismic, hydro-acoustic and infrasonic waves: numerical analysis and case studies.

    Science.gov (United States)

    Terrana, S.; Vilotte, J. P.; Guillot, L.

    2015-12-01

    New seismological monitoring networks combine broadband seismic receivers, hydrophones and micro-barometers antenna, providing complementary observation of source-radiated waves. Exploiting these observations requires accurate and multi-media - elastic, hydro-acoustic, infrasound - wave simulation methods, in order to improve our physical understanding of energy exchanges at material interfaces.We present here a new development of a high-order Hybridized Discontinuous Galerkin (HDG) method, for the simulation of coupled seismic and acoustic wave propagation, within a unified framework ([1],[2]) allowing for continuous and discontinuous Spectral Element Methods (SEM) to be used in the same simulation, with conforming and non-conforming meshes. The HDG-SEM approximation leads to differential - algebraic equations, which can be solved implicitly using energy-preserving time-schemes.The proposed HDG-SEM is computationally attractive, when compared with classical Discontinuous Galerkin methods, involving only the approximation of the single-valued traces of the velocity field along the element interfaces as globally coupled unknowns. The formulation is based on a variational approximation of the physical fluxes, which are shown to be the explicit solution of an exact Riemann problem at each element boundaries. This leads to a highly parallel and efficient unstructured and high-order accurate method, which can be space-and-time adaptive.A numerical study of the accuracy and convergence of the HDG-SEM is performed through a number of case studies involving elastic-acoustic (infrasound) coupling with geometries of increasing complexity. Finally, the performance of the method is illustrated through realistic case studies involving ground wave propagation associated to topography effects.In conclusion, we outline some on-going extensions of the method.References:[1] Cockburn, B., Gopalakrishnan, J., Lazarov, R., Unified hybridization of discontinuous Galerkin, mixed and

  13. 混合隔振系统自适应模糊滑模控制%Adaptive Fuzzy Sliding-mode Controller for Hybrid Vibration Isolation Systems

    Institute of Scientific and Technical Information of China (English)

    杨理华; 朱石坚; 楼京俊; 李棒

    2014-01-01

    针对机械设备被动隔振在低频段隔振效果较差的问题,建立磁致伸缩作动器的电—磁—机转化数学模型,提出一种基于自适应模糊滑模控制算法,并用李雅普诺夫方法证明控制器的稳定性,将该控制策略与磁致伸缩作动器应用于混合隔振系统中。仿真结果表明:在单频、多频及随即激励条件下,自适应模糊滑模控制器具有良好的动态特性和鲁棒性,能够提高系统隔振效率并拓宽隔振频段,有效减小传至基础的力。%Aiming at the problem of poor vibration isolation effect of passive vibration isolators of mechanical equip-ment in low frequency range, an electric-magnetic-mechanical conversion model for magnetostrictive actuators is estab-lished, and an adaptive fuzzy sliding-mode control algorithm is proposed. The stability of the controller is proved by Lyapu-nov method. Then, the control strategy and the magnetostrictive actuator are used in a hybrid vibration isolation system. The simulation results show that in whatever conditions of single frequency excitation, multi-frequency excitation or random ex-citation, the adaptive fuzzy sliding-mode controller has good dynamic characteristics and robustness. This property can also be used to improve the isolation efficiency and broaden the vibration isolation frequency band of the hybrid system, and ef-fectively reduce the force transmitted to the foundation of the mechanical equipment.

  14. Calculating the Energy Cost of CO2 Removal in a Coal Based Gas Turbine Fuel Cell Hybrid Power Generation System with an Isolated Anode Stream

    Energy Technology Data Exchange (ETDEWEB)

    Vanosdol, J G; Gemmen, R S; Liese, E A

    2007-10-01

    In recent years there has been significant interest in identifying carbon capturing technologies that can be applied to fossil fuel power generation plants.CO2 capture technologies seek to reduce the amount of CO2 that would normally be emitted into the atmosphere from the daily operation of these plants. In terms of system efficiency and operating costs, this carbon capture is expensive. Further, the additional equipment that would be used to capture CO2 emissions greatly adds to the complexity of the system. There has also been significant interest in coal based gas turbine fuel cell hybrid power plants. A hybrid power plant can have much greater system efficiency than a normal gas turbine power plant because the heat that is normally unused in a standalone solid oxide fuel cell (SOFC) is recovered and used to drive a power producing turbine. It is thought that the increased system efficiency of the hybrid system might compensate for the increased expense of performing carbon capture. In order to provide some analytical insight on this tradeoff we present a 100 MW class coal fired gas turbine SOFC hybrid power generation system. The hybrid system operates at a pressure ratio of 6, and uses heat recuperation and cathode air recirculation to control the SOFC inlet temperature and the temperature change across the SOFC. A carbon capture scheme is added to this system in order to calculate the relative energy cost in terms of system efficiency due to CO2 compression. The carbon capture is performed by burning the unused fuel from the SOFC in an isolated anode stream using pure O2 injection. The resulting heat that is generated from this process is then used to drive a secondary turbine that is placed in the anode exhaust stream where more work is extracted. With an isolated anode stream, the products of combustion from this secondary combustion process are mostly water and carbon dioxide. The water by-product is

  15. Isolation of novel non-HLA gene fragments from the hemochromatosis region (6p21. 3) by cDNA hybridization selection

    Energy Technology Data Exchange (ETDEWEB)

    Goei, V.L.; Capossela, A.; Gruen, J.R.; Parimoo, S.; Chu, T.W. (Yale Univ. School of Medicine, New Haven, CT (United States))

    1994-02-01

    It has previously been shown that cDNA hybridization selection can identify and recover novel genes from large cloned genomic DNA such as cosmids or YACs. In an effort to identify candidate genes for hemochromatosis, this technique was applied to a 320-kb YAC containing the HLA-A gene. A short fragment cDNA library derived from human duodenum was selected with the YAC DNA. Ten novel gene fragments were isolated, characterized, and localized on the physical map of the YAC. 39 refs., 4 figs., 3 tabs.

  16. 4Nx Non-Isolated and Non-Inverting Hybrid Interleaved Multilevel Boost Converter Based on VLCIm Cell and Cockroft Walton Voltage Multiplier for Renewable Energy Applications

    DEFF Research Database (Denmark)

    Bhaskar, Mahajan Sagar; Padmanaban, Sanjeevikumar; Blaabjerg, Frede

    2016-01-01

    In this treatise, 4Nx hybrid Non Inverting & Non Isolated (NI-NI) DC-DC interleaved multi-level boost converter (4Nx IMBC) for renewable energy applications is proposed. The proposed 4Nx IMBC is derived by coalescing the feature of 2Nx DC-DC Interleaved Multi-level Boost Converter (2Nx IMBC......), voltage-lift-switched-inductor-modified (VLSlm Cell) and Cockcroft Walton (CW) voltage multipliers. The 4Nx converter provides 4N times more conversion voltage ratio compared to conventional boost converter where N denotes the number of output stages of the 4Nx IMBC. To make renewable energy sources...

  17. Seismic Symphonies

    Science.gov (United States)

    Strinna, Elisa; Ferrari, Graziano

    2015-04-01

    The project started in 2008 as a sound installation, a collaboration between an artist, a barrel organ builder and a seismologist. The work differs from other attempts of sound transposition of seismic records. In this case seismic frequencies are not converted automatically into the "sound of the earthquake." However, it has been studied a musical translation system that, based on the organ tonal scale, generates a totally unexpected sequence of sounds which is intended to evoke the emotions aroused by the earthquake. The symphonies proposed in the project have somewhat peculiar origins: they in fact come to life from the translation of graphic tracks into a sound track. The graphic tracks in question are made up by copies of seismograms recorded during some earthquakes that have taken place around the world. Seismograms are translated into music by a sculpture-instrument, half a seismograph and half a barrel organ. The organ plays through holes practiced on paper. Adapting the documents to the instrument score, holes have been drilled on the waves' peaks. The organ covers about three tonal scales, starting from heavy and deep sounds it reaches up to high and jarring notes. The translation of the seismic records is based on a criterion that does match the highest sounds to larger amplitudes with lower ones to minors. Translating the seismogram in the organ score, the larger the amplitude of recorded waves, the more the seismogram covers the full tonal scale played by the barrel organ and the notes arouse an intense emotional response in the listener. Elisa Strinna's Seismic Symphonies installation becomes an unprecedented tool for emotional involvement, through which can be revived the memory of the greatest disasters of over a century of seismic history of the Earth. A bridge between art and science. Seismic Symphonies is also a symbolic inversion: the instrument of the organ is most commonly used in churches, and its sounds are derived from the heavens and

  18. Isolation and characterization of potato-tomato somatic hybrids using an amylose-free potato mutant as parental genotype.

    Science.gov (United States)

    Jacobsen, E; Reinhout, P; Bergervoet, J E; de Looff, J; Abidin, P E; Huigen, D J; Ramanna, M S

    1992-11-01

    Using different genotypes of tomato and diploid potato, possessing alien selectable markers as well as endogenous markers, very high frequencies of protoplast fusion hybrids were obtained. One endogenous genetic marker, the amylose-free (amf) mutant of potato, was helpful not only for the confirmation of fusion products but also for the study of genetic complementation and the segregation of amylose-free starch in microspores. Cytological analysis of the fusion hybrids indicated that except for one which was hexaploid, all of them had a perfectly balanced chromosome number of allotetraploid constitution (2n = 4x = 48). Despite normal chromosome pairing and a diploid behaviour, the microspores in some of the fusion hybrids segregated for the recessive amf-locus. This anomalous segregation of a recessive character in these hybrids was shown not to be due to chromosome elimination or to the absence of the wild-type tomato Amf gene. Although all fusion hybrids were totally sterile, the hexaploid produced stainable pollen and berries with badly developed seeds. Embryo rescue has so far failed to produce backcross progeny.

  19. Isolating cells from female/male blood mixtures using florescence in situ hybridization combined with low volume PCR and its application in forensic science.

    Science.gov (United States)

    Feng, Lei; Li, Cai-Xia; Han, Jun-Ping; Xu, Cheng; Hu, Lan

    2015-11-01

    To obtain single-source short tandem repeat (STR) profiles in trace female/male blood mixture samples, we combined florescence in situ hybridization (FISH), laser microdissection, and low volume PCR (LV-PCR) to isolate male/female cells and improve sensitivity. The results showed that isolation of as few as 10 leukocytes was sufficient to yield full STR profiles in fresh female or male blood samples for 32 independent tests with a low additional alleles rate (3.91%) and drop-out alleles rate (5.01%). Moreover, this procedure was tested in two fresh blood mixture series at three ratios (1:5, 1:10, and 1:20), two mock female/male blood mixture casework samples, and one practical casework sample. Male and female STR profiles were successfully detected in all of these samples, showing that this procedure could be used in forensic casework in the future.

  20. Present State of Explosion Seismic Wave Research and Primary Investigation on Its Characteristics

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The present state and the significance of research on explosion seismic waves are discussed, and meanwhile the main contents and the basic problems to be solved in the study of explosion seismic waves are analyzed. The spectra characteristics of explosion seismic waves, functions of the isolated-seismic grooves and influences of the detonating methods on explosion seismic waves are investigated by experiments. The experimental method is introduced. Some experimental results are presented which are concerned with the influences of topographical conditions, explosive charges, ignition patterns, isolated-seismic grooves and the other related factors on the characteristics of seismic waves.

  1. Development of hybrid type pneumatic vibration isolation table by piezo-stack actuator and filtered-X LMS algorithm

    Science.gov (United States)

    Shin, Yun-ho; Jang, Dong-doo; Moon, Seok-jun; Jung, Hyung-Jo; Moon, Yeong-jong; Song, Chang-kyu

    2011-04-01

    Recently, vibration requirements are getting stricter as precise equipments need more improved vibration environment to realize their powerful performance. Though the passive pneumatic vibration isolation tables are frequently used to satisfy the rigorous vibration requirements, the specific vibration problem, especially continuous sinusoidal or periodic vibration induced by a rotor system of other precise equipment, a thermo-hygrostat or a ventilation system, is still left. In this research, the application procedure of Filtered-X LMS algorithm to pneumatic vibration isolation table with piezo-stack actuators is proposed to enhance the isolation performance for the continuous sinusoidal or periodic vibration. In addition, the experimental results to show the isolation performance of proposed system are also presented together with the isolation performance of passive pneumatic isolation table.

  2. 基于土-结构相互作用的隔震连续梁桥的地震响应%Seismic response of isolated continuous girder bridges based on soil-pile-bridges interaction

    Institute of Scientific and Technical Information of China (English)

    陈水生; 马涌泉

    2012-01-01

    Taking the three spans isolated continuous girder bridges for the engineering background, Bouc-Wen restoring force model is adopted to simulate the nonlinear characteristics for LRB, multi-story liner system concentrated quality finite clement analytic model considering SSI is established, and the time-history analysis procedure of the Wilson- θ step-by-step integration method used to solve the increment form nonlinear governing equation of motion considering SSI is programmed. We make a contrastive analysis based on before and after isolated bridges model of considering SSI and rigid foundation hypotheses by combining the procedure with calculation example. The results indicate that the considering SSI has larger value on the seismic response than the rigid foundation, but the seismic response value has no great difference between two models under pulse of type Ⅰ and Ⅱ- The considering SSI has larger value on the seismic response than the rigid foundation under pulse of type Ⅲ, so the SSI can not be neglected in the isolated seismic design of bridges under pulse of type Ⅲ. The LRB isolated rate has insensitive to considering SSI or not, and LRB isolated rate has no great difference between two models under the same type of pulse, but the effect of LRB under pulse of typeⅠ and Ⅱis superior to effect of LRB under pulse of type Ⅲ.%以典型三跨隔震连续梁桥为工程背景,采用Bouc-Wen滞回恢复力模型,模拟LRB( lead rubber bearings)的力-位移非线性特性,建立了考虑土-结构相互作用的多质点系集中质量有限元计算模型,编制了运用Wilson-θ逐步积分法求解增量形式的土结构体系非线性运动方程的时程分析程序,利用程序并结合算例分别对考虑土-结构相互作用与按照墩底固结假设的两种桥梁模型进行了隔震前后的时程对比分析.结果表明:在Ⅰ、Ⅱ类场地土上,考虑土结构相互作用与按照墩底固结假设相比,前者得到的地震响

  3. Investigations of different hybrids and alternative renewables for the electrification of remote sites; Investigations des differentes alternatives renouvelables et hybrides pour l'electrification des sites isoles

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, H.; Ilinca, A. [Quebec Univ., Rimouski, PQ (Canada). Laboratoire de Recherche en Energie Eolienne; Perron, J. [Quebec Univ., Chicoutimi, PQ (Canada). Laboratoire International des Materiaux Antigivre

    2008-09-15

    Diesel generators are the main source of electricity in remote areas. Efforts are underway to replace costly diesel fuel with renewable energy sources. However, one of the limiting factors of renewable energy is the variety of resource available. This document explored the possibility of combining different sources, such as wind turbines, solar panels and diesel generators. Although renewable energy produced by way of wind power or photovoltaic sources is not efficient on its own, when combined with a diesel generator it can provide continuous electricity without interruptions. The basic principles of a hybrid system are to provide continuous energy in an economical manner and have automated systems between renewable energy and traditional energy to ensure continuous electrical supply. Investment costs should also be recoverable. Other factors that must be taken into consideration are performance, service life, fuel economy, cost per kWh, the number and duration of electrical failures, and number of interruptions for repair. This document also discussed energy storage issues. 7 refs., 42 figs.

  4. Detection of mutation in embB gene of Mycobacterium tuberculosis from clinical isolates of tuberculous patients in China by means of reverse-dot blot hybridization

    Institute of Scientific and Technical Information of China (English)

    XUE QIONG WU; YANG LU; JIAN QIN LIANG; JUN XIAN ZHANG; GUANG YU ZHANG; CUI HUAN L(U); HONG MIN LI; BEI CHUAN DING

    2006-01-01

    The relationship between embB mutation of Mycobacterium tuberculosis and ethambutol (EMB) resistance of the clinical isolates of tuberculous patients in China was investigated by reversedot blot hybridization (RDBH) in addition to evaluating the clinical value with application of PCR-RD-BH technique to detect EMB resistance. In the present study, the genotypes of the 258 bp fragments of embB genes from 196 clinical isolates of M. tuberculosis were analysed with RDBH and DNA sequencing. It was demonstrated that 60 out of 91 phenotypically EMB-resistant isolates (65.9%) showed 5 types of missense mutations at codon 306 of embB gene, resulting in the replacement of the Met residue of the wild type strain with Val, Ile or Leu residues. In these mutations, the GTP mutation (38/91,41.8% ) and the ATA mutation ( 16/91, 17.6% ) were the most encountered genotypes. The embB mutation at codon 306 could also be found in 69 isolates of phenotypically EMB-sensitive but resistant to other anti-tuberculous drugs, but no such gene mutation could be found in 36 strains of drug-sensitive isolates. Meanwhile, the concordance with the results of DNA sequencing for one wide-type probe and 5 probes for specific mutations was 100%. It was concluded that the EMB-resistance occurring in most M. tuberculosis is due to appearance of embB mutation at codon 306, and the PCR-RDBH assay was proved to be a rapid, simple and reliable method for the detection of gene mutations, which might be a good alternative for the drug-resistance screening.

  5. Isolation of Related Genes of Cardiac Hypertrophy in Pressure overloaded Rat Models with Subtractive Hybridization%压力负荷型心肌肥厚大鼠心肌组织相关基因的分离

    Institute of Scientific and Technical Information of China (English)

    田靫; 潘德思; 陈兰英

    2000-01-01

    Cardiac hypertrophy is intensively related with the morbidity of heart failure,atherosclerosis and stroke. The rat models of left ventricular hypertrophy caused by abdominal aorta constriction and the method of subtractive hybridization to isolate genes expressing differently were used during cardiac hypertrophy. 24 cDNA segments were isolated and identified by colony and dot hybridization. Sequence homogenous comparison showed that some of them were very similar to known genes or segments, others were limitedly homogenous and the rest were not found to be significantly homogenous.

  6. The efficiency of using a seismic base isolation system for a 2D concrete frame founded upon improved soft soil with rigid inclusions

    Science.gov (United States)

    Awwad, Talal; Donia, Modar

    2016-03-01

    2D finite element models were developed to analyze the effect of improved soft-soil foundation on the efficiency of a base-isolated concrete frame. Static and dynamic analyses were performed for a frame on raft foundation. Non-improved and improved soft-soil foundation using rigid inclusions were considered, as well as the use of high damping rubber bearing as base isolation. Results show that the use of rigid inclusions increases the efficiency of base isolation; base shear is reduced by 38% and maximum acceleration at the top of the frame by 30%.

  7. Seismic Response of a Full-scale 5-story Steel Frame Building Isolated by Triple Pendulum Bearings under Three-Dimensional Excitations

    Science.gov (United States)

    Dao, Nhan Dinh

    A full-scale shake table test of a 5-story steel moment frame building was carried out as part of a collaborative NEES/E-Defense research program. The building was tested in three configurations: isolated with triple pendulum bearings (TPB), isolated with lead rubber bearings combined with cross linear sliders (which is not discussed in this dissertation), and fixed base. The test provided full-scale response data of both the isolation system and the isolated structure and demonstrated the efficiency of the isolation system in reducing the demands in the isolated structure. A 3-dimensional TPB element with a general friction model that accounts for the variation of friction coefficients on both velocity and vertical force was developed to predict the response of individual TPB and the overall isolation system. The element accounts for both vertical-horizontal coupling behavior and bidirectional coupling of TPB. The horizontal behavior of the element is based on a series combination of bidirectional elastic-plastic springs and the circular gap elements. The new TPB element was verified by the full scale test data and has been implemented in OpenSees so that it is available for general use. The analytical model of the specimen building was also developed and validated by the test data from both the isolated base and fixed base tests. The following modeling assumption were shown to best present the response characteristics of the tested structure: (1) beam were modeled as nonlinear elements with resultant composite sections, (2) moment connection were modeled using a Krawinkler panel zone model, and (3) energy dissipation was represented by Rayleigh damping calibrated to include higher mode effects observed in the test data, along with additional interstory dampers. The vertical component of the excitation was shown to amplify the horizontal response of both the fixed base and isolated base structures. This coupling effect was small in the tested fixed base

  8. Base isolation: Fresh insight

    Energy Technology Data Exchange (ETDEWEB)

    Shustov, V.

    1993-07-15

    The objective of the research is a further development of the engineering concept of seismic isolation. Neglecting the transient stage of seismic loading results in a widespread misjudgement: The force of resistance associated with velocity is mostly conceived as a source of damping vibrations, though it is an active force at the same time, during an earthquake type excitation. For very pliant systems such as base isolated structures with relatively low bearing stiffness and with artificially added heavy damping mechanism, the so called `damping`` force may occur even the main pushing force at an earthquake. Thus, one of the two basic pillars of the common seismic isolation philosophy, namely, the doctrine of usefulness and necessity of a strong damping mechanism, is turning out to be a self-deception, sometimes even jeopardizing the safety of structures and discrediting the very idea of seismic isolation. There is a way out: breaking with damping dependancy.

  9. SEISMIC GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20091465 Cai Xuelin(College of Earth Sciences,Chengdu University of Technology,Chengdu 610059,China);Cao Jiamin Preliminary Study on the 3-D Crust Structure for the Longmen Lithosphere and the Genesis of the Huge Wenchuan Earthquake,Sichuan Province,China(Journal of Chengdu University of Technology,ISSN1671-9727,CN51-1634/N,35(4),2008,p.357-365,8 illus.,39 refs.)Key words:deep-seated structures,large earthquakes,Longmenshan Fracture ZoneBased on a structural analysis of many seismic sounding profiles,there are two fault systems in Longmen collisional orogenic belt,Sichuan Province,China.They are both different obviously and correlative closely.One is shallow fault system composed mainly of brittle shear zones in surface crust,and the other is deep fault system composed mainly of crust-mantle ductile shear zones cutting Moho discontinuity.Based on the result of researching geological structure and seismic sounding profiles,

  10. Analysis and Design of a Bidirectional Isolated DC-DC Converter for Fuel Cell and Super-Capacitor Hybrid System

    DEFF Research Database (Denmark)

    Zhang, Zhe; Ouyang, Ziwei; Thomsen, Ole Cornelius

    2012-01-01

    Electrical power system in future uninterruptible power supply (UPS) or electrical vehicle (EV) may employ hybrid energy sources, such as fuel cells and super-capacitors. It will be necessary to efficiently draw the energy from these two sources as well as recharge the energy storage elements...... for zero voltage switching (ZVS). Moreover, a phase-shift and duty cycle modulation method is utilized to control the bidirectional power flow flexibly and it also makes the converter operate under a quasi-optimal condition over a wide input voltage range. This paper describes the operation principle...

  11. Isolation and characterization of CCoAOMT in interspecific hybrid of Acacia auriculiformis x Acacia mangium--a key gene in lignin biosynthesis.

    Science.gov (United States)

    Pang, S L; Ong, S S; Lee, H H; Zamri, Z; Kandasamy, K I; Choong, C Y; Wickneswari, R

    2014-09-05

    This study was directed at the understanding of the function of CCoAOMT isolated from Acacia auriculiformis x Acacia mangium. Full length cDNA of the Acacia hybrid CCoAOMT (AhCCoAOMT) was 1024-bp long, containing 750-bp coding regions, with one major open reading frame of 249 amino acids. On the other hand, full length genomic sequence of the CCoAOMT (AhgflCCoAOMT) was 2548 bp long, containing three introns and four exons with a 5' untranslated region (5'UTR) of 391 bp in length. The 5'UTR of the characterized CCoAOMT gene contains various regulatory elements. Southern analysis revealed that the Acacia hybrid has more than three copies of the CCoAOMT gene. Real-time PCR showed that this gene was expressed in root, inner bark, leaf, flower and seed pod of the Acacia hybrid. Downregulation of the homologous CCoAOMT gene in tobacco by antisense (AS) and intron-containing hairpin (IHP) constructs containing partial AhCCoAOMT led to reduction in lignin content. Expression of the CCoAOMT in AS line (pART-HAS78-03) and IHP line (pART-HIHP78-06) was reduced respectively by 37 and 75% compared to the control, resulting in a decrease in the estimated lignin content by 24 and 56%, respectively. AhCCoAOMT was found to have altered not only S and G units but also total lignin content, which is of economic value to the pulp industry. Subsequent polymorphism analysis of this gene across eight different genetic backgrounds each of A. mangium and A. auriculiformis revealed 47 single nucleotide polymorphisms (SNPs) in A. auriculiformis CCoAOMT and 30 SNPs in A. mangium CCoAOMT.

  12. Synthesis of a novel molecularly imprinted organic-inorganic hybrid polymer for the selective isolation and determination of fluoroquinolones in tilapia.

    Science.gov (United States)

    Yang, Xun; Wang, Ruiling; Wang, Weihua; Yan, Hongyuan; Qiu, Mande; Song, Yanxue

    2014-01-15

    A novel molecularly imprinted organic-inorganic hybrid polymer (MI-MAA/APTS) based on a dummy molecular imprinting technique and an organic-inorganic hybrid material technique was synthesised and used as a sorbent in solid-phase extraction for the selective isolation and determination of ofloxacin (OFL), lomefloxacin (LOM), and ciprofloxacin (CIP) in tilapia samples. The MI-MAA/APTS sorbent was prepared from 3-aminopropyltriethoxysilanes (APTS) as an inorganic source and methacrylic acid (MAA) as an organic source and exhibited high mechanical strength and special affinities to the analytes. A comparison of MI-MAA/APTS with other conventional sorbents (C18 and HLB) showed that MI-MAA/APTS displayed good selectivity and affinity for OFL, LOM, and CIP, and the recoveries of the analytes at three spiked levels were in the range of 85.1-101.0%, with the relative standard deviations ≤5.1%. The presented MI-MAA/APTS-SPE-HPLC method could be potentially applied to the determination of fluoroquinolones (FQs) in complex fish samples.

  13. Quantitative Seismic Amplitude Analysis

    OpenAIRE

    Dey, A. K.

    2011-01-01

    The Seismic Value Chain quantifies the cyclic interaction between seismic acquisition, imaging and reservoir characterization. Modern seismic innovation to address the global imbalance in hydrocarbon supply and demand requires such cyclic interaction of both feed-forward and feed-back processes. Currently, the seismic value chain paradigm is in a feed-forward mode. Modern seismic data now have the potential to yield the best images in terms of spatial resolution, amplitude accuracy, and incre...

  14. Seismic data matching pursuit using hybrid optimization algorithm and its application%基于混合优化算法的地震数据匹配追踪分解

    Institute of Scientific and Technical Information of China (English)

    蔡涵鹏; 贺振华; 高刚; 黄德济

    2013-01-01

    以5个参数(幅度、频率、相位移、尺度因子、时移)控制的Morlet小波作为匹配子波原子,在确定控制参数的过程中,提出应用具有全局优化能力的粒子群优化算法与具有局部优化能力的BFGS算法的混合优化算法,能够使得匹配追踪算法不再依赖于复数道分析确定子波原子的振幅、频率和相位的初值.控制子波时间延续长度的尺度因子是一个重要的参数.匹配追踪分解后,消除较小和较大的尺度因子和分解终止时的剩余信号能够有效地压制地震数据噪声.利用局部函数解析表达式和残差信号能量进行有效地控制算法的迭代次数可以提高计算效率.数值试验和实际资料的应用均表明:利用本文方法能够压制地震数据噪声,对地震信号快速地、精确地进行时频谱分析,为烃类检测和储层描述提供有效的手段.%Morlet wavelet with five parameters, including amplitude, frequency, phase, scale factor and time delay, as atoms in the matching pursuit decomposition was employed. In the processing of established controlled variable, hybrid optimization algorithm was introduced, including particle swarm optimization and BFGS method, so as to in-depend on complex-trace analysis to determine initial value of controlled variable, such as amplitude, frequency, and phase. The scale factor is an important adaptive parameter that controls the width of wavelet in time. After matching pursuit decomposition, removing wavelets with either very small or very large scale value and residual signal can suppress spikes and sinusoid functions, and rand noise effectively from seismic data. For fast matching pursuit algorithm, analytical expressions and the energy of the residual signal were employed which control effectively the iterating times. Synthetic data test and results of practical data application show that using method in the paper has good effect in the aspect of attenuating noise form

  15. Static stability analysis of a passive-active hybrid vibration isolator%磁悬浮主被动混合隔振器静稳定性分析

    Institute of Scientific and Technical Information of China (English)

    倪圆; 何琳; 帅长庚; 李彦

    2015-01-01

    Passive-active vibration isolator using maglev actuator is a elastic structure combining positive and negative stiffness. Stiffness model of the hybrid vibration isolator is established to solve the stability problem of the structure. According to virtual work principle, the stiffness principle determining the static stability of a elastic system is derived. This stiffness principle combining the stiffness model is used to ana-lyze the static stability of the hybrid vibration isolator. Theory and experimental results show that the stiff-ness of the hybrid vibration isolator is positive for working displace, and the isolator is stable.%磁悬浮主被动混合隔振器是一种正负刚度并联的弹性结构.针对该结构存在的稳定性问题,建立了某型磁悬浮主被动混合隔振器的刚度模型. 基于虚功原理,推导出判定弹性系统静稳定性的刚度准则. 运用该准则,结合混合隔振器的刚度模型分析了该主被动混合隔振器的静稳定性. 理论和实验结果表明,该混合隔振器在工作位移内,系统刚度为正,混合隔振器是静稳定的.

  16. Isolation and Expression Analysis of Novel Silicon Absorption Gene from Roots of Mangrove (Rhizophora apiculata via Suppression Subtractive Hybridization

    Directory of Open Access Journals (Sweden)

    Mahbod Sahebi

    2014-01-01

    Full Text Available Silicon (Si is the second most abundant element in soil after oxygen. It is not an essential element for plant growth and formation but plays an important role in increasing plant tolerance towards different kinds of abiotic and biotic stresses. The molecular mechanism of Si absorption and accumulation may differ between plants, such as monocotyledons and dicotyledons. Silicon absorption and accumulation in mangrove plants are affected indirectly by some proteins rich in serine and proline amino acids. The expression level of the genes responsible for Si absorption varies in different parts of plants. In this study, Si is mainly observed in the epidermal roots’ cell walls of mangrove plants compared to other parts. The present work was carried out to discover further information on Si stress responsive genes in Rhizophora apiculata, using the suppression subtractive hybridization technique. To construct the cDNA library, two-month-old seedlings were exposed to 0.5, 1, and 1.5 mM SiO2 for 15 hrs and for 1 to 6 days resulting in a total of 360 high quality ESTs gained. Further examination by RT-PCR and real-time qRT-PCR showed the expression of a candidate gene of serine-rich protein.

  17. Isolation and expression analysis of novel silicon absorption gene from roots of mangrove (Rhizophora apiculata) via suppression subtractive hybridization.

    Science.gov (United States)

    Sahebi, Mahbod; Hanafi, Mohamed M; Abdullah, Siti Nor Akmar; Rafii, Mohd Y; Azizi, Parisa; Nejat, Naghmeh; Idris, Abu Seman

    2014-01-01

    Silicon (Si) is the second most abundant element in soil after oxygen. It is not an essential element for plant growth and formation but plays an important role in increasing plant tolerance towards different kinds of abiotic and biotic stresses. The molecular mechanism of Si absorption and accumulation may differ between plants, such as monocotyledons and dicotyledons. Silicon absorption and accumulation in mangrove plants are affected indirectly by some proteins rich in serine and proline amino acids. The expression level of the genes responsible for Si absorption varies in different parts of plants. In this study, Si is mainly observed in the epidermal roots' cell walls of mangrove plants compared to other parts. The present work was carried out to discover further information on Si stress responsive genes in Rhizophora apiculata, using the suppression subtractive hybridization technique. To construct the cDNA library, two-month-old seedlings were exposed to 0.5, 1, and 1.5 mM SiO2 for 15 hrs and for 1 to 6 days resulting in a total of 360 high quality ESTs gained. Further examination by RT-PCR and real-time qRT-PCR showed the expression of a candidate gene of serine-rich protein.

  18. Isolation and Characterization of a Hybrid Respiratory Supercomplex Consisting of Mycobacterium tuberculosis Cytochrome bcc and Mycobacterium smegmatis Cytochrome aa3.

    Science.gov (United States)

    Kim, Mi-Sun; Jang, Jichan; Ab Rahman, Nurlilah Binte; Pethe, Kevin; Berry, Edward A; Huang, Li-Shar

    2015-06-05

    Recently, energy production pathways have been shown to be viable antitubercular drug targets to combat multidrug-resistant tuberculosis and eliminate pathogen in the dormant state. One family of drugs currently under development, the imidazo[1,2-a]pyridine derivatives, is believed to target the pathogen's homolog of the mitochondrial bc1 complex. This complex, denoted cytochrome bcc, is highly divergent from mitochondrial Complex III both in subunit structure and inhibitor sensitivity, making it a good target for drug development. There is no soluble cytochrome c in mycobacteria to transport electrons from the bcc complex to cytochrome oxidase. Instead, the bcc complex exists in a "supercomplex" with a cytochrome aa3-type cytochrome oxidase, presumably allowing direct electron transfer. We describe here purification and initial characterization of the mycobacterial cytochrome bcc-aa3 supercomplex using a strain of M. smegmatis that has been engineered to express the M. tuberculosis cytochrome bcc. The resulting hybrid supercomplex is stable during extraction and purification in the presence of dodecyl maltoside detergent. It is hoped that this purification procedure will potentiate functional studies of the complex as well as crystallographic studies of drug binding and provide structural insight into a third class of the bc complex superfamily.

  19. Chromosome isolation by flow sorting in Aegilops umbellulata and Ae. comosa and their allotetraploid hybrids Ae. biuncialis and Ae. geniculata.

    Directory of Open Access Journals (Sweden)

    István Molnár

    Full Text Available This study evaluates the potential of flow cytometry for chromosome sorting in two wild diploid wheats Aegilops umbellulata and Ae. comosa and their natural allotetraploid hybrids Ae. biuncialis and Ae. geniculata. Flow karyotypes obtained after the analysis of DAPI-stained chromosomes were characterized and content of chromosome peaks was determined. Peaks of chromosome 1U could be discriminated in flow karyotypes of Ae. umbellulata and Ae. biuncialis and the chromosome could be sorted with purities exceeding 95%. The remaining chromosomes formed composite peaks and could be sorted in groups of two to four. Twenty four wheat SSR markers were tested for their position on chromosomes of Ae. umbellulata and Ae. comosa using PCR on DNA amplified from flow-sorted chromosomes and genomic DNA of wheat-Ae. geniculata addition lines, respectively. Six SSR markers were located on particular Aegilops chromosomes using sorted chromosomes, thus confirming the usefulness of this approach for physical mapping. The SSR markers are suitable for marker assisted selection of wheat-Aegilops introgression lines. The results obtained in this work provide new opportunities for dissecting genomes of wild relatives of wheat with the aim to assist in alien gene transfer and discovery of novel genes for wheat improvement.

  20. Studies on seismic waves

    Institute of Scientific and Technical Information of China (English)

    张海明; 陈晓非

    2003-01-01

    The development of seismic wave study in China in the past four years is reviewed. The discussion is divided into several aspects, including seismic wave propagation in laterally homogeneous media, laterally heterogeneous media, anisotropic and porous media, surface wave and seismic wave inversion, and seismic wave study in prospecting and logging problems. Important projects in the current studies on seismic wave is suggested as the development of high efficient numerical methods, and applying them to the studies of excitation and propagation of seismic waves in complex media and strong ground motion, which will form a foundation for refined earthquake hazard analysis and prediction.

  1. Seismic response of a high-rise isolation structure 2-mass model with pure mass method%高层隔震结构双质点模型的地震响应单纯质点法研究

    Institute of Scientific and Technical Information of China (English)

    刘阳; 刘文光; 何文福; 杨巧荣

    2013-01-01

    Aiming at a two-mass simplified model of a high-rise isolated structure, the pure mass method ( PMM) utilized to calculate quickly earthquake responses of high-rise isolated structures was proposed here. Firstly, the conversion relation between the two-mass simplified model and the archetype was established and the parameters of the two-mass model were determined according to the equivalent criteria for base shear force and energy. And then, two key parameters of stiffness conversion coefficient and mass ratio were obtained to determine seismic responses. The envelope response calculation formulas of the simplified model were proposed based on the energy balance method. The energy balance method and the model conversion relation were used to predict the seismic response envelope values of every layer of the archetype. An engineering example of 22-story high-rise isolated structure was converted into a two-mass simplified model. Then, the effectiveness and analysis accuracy of the pure mass model method were verified. It was shown that computational results of the new method are similar to those with multi-mass model time history analysis method; the calculation time of the proposed method is less, and the model parameters determination is clear and convenient; the new method can be applied to analyze the earthquake responses of high-rise isolated structures.%针对高层隔震结构的双质点简化模型提出了可快速计算其地震响应的单纯质点法,该方法基于基底剪力及能量等效原则来建立简化两质点分析模型与原结构模型之间的转换关系及简化模型的参数取值,推导得到了确定地震反应的两个关键参数:刚度转换系数和质量比.研究基于能量平衡方法提出了高层隔震结构简化分析模型包络反应的计算式,并通过利用能量平衡原理及模型参数转换关系来预测原高层隔震结构的各层地震反应包络值.对22层高层隔震结构工程实例首先进

  2. Seismic Behavior Analysis and Evaluation of the Isolation Structure of An Engineering Foundation%某工程基础隔震结构抗震性能分析与评价

    Institute of Scientific and Technical Information of China (English)

    江泳

    2015-01-01

    对隔震层位于地下室柱顶的基础隔震四层框架结构,应用有限元软件ETABS进行三维建模和时程分析,同时设计中考虑了优化隔震支座的布置减小结构扭转效应、选取较大直径的隔震支座、加强地下室独立柱的刚度和结构有一定抵抗超烈度的安全储备等措施。设计和计算结果表明:在设防烈度7度(0.15 g )中震作用下,水平向减震系数0.35;在7度(0.15 g )大震作用下,上部结构基本处于弹性;在超烈度8度(0.20 g )大震作用下,独立柱位移角仍然极小,楼层加速度减震效果显著,隔震层水平位移不超过限值的80%,整体结构具有较高的抗震性能。%Regarding to a four-floor kindergarten building with its isolation layer on top of the basement columns ,a 3D model was established and the time-history analysis was conducted using the finite element software ETABS .In the de-sign ,some measures were also considered including optimizing the arrangement of isolation bearings to reduce torsional effect , selecting the the isolation bearings with larger diameter , strengthening the stiffness of basement independent columns and structures which have certain security storage for resisting ultra intensity .The design and calculation results indicate that the damping coefficient in horizontal direction is 0 .35 under 7 degree (0 .15 g) moderate earthquake;the upper part of the structure is elastic under 7 degree (0 .15 g ) strong earthquake;the independent column displacement angle is still minimum under 8 degree (0 .20 g ) ultra intensive earthquake ,and the floor acceleration damping effect is remarkable with the horizontal displacement of the isolation layer less than 80% of the limiting value ,therefore the over-all structure has a high seismic performance .

  3. 竖向刚度对偏心辊轴摩擦摆隔震系统性能影响研究%Disturbance from Vertical Oscillation to Seismic Isolation Behavior of ERFPS System

    Institute of Scientific and Technical Information of China (English)

    葛楠; 苏幼坡; 王兴国; 周锡元

    2011-01-01

    根据多体动力学相对动能定理推求了偏心辊轴摩擦摆隔震系统动力反应分析计算公式,并考虑了竖向刚度的影响.分析与计算结果表明:设置偏心辊轴摩擦摆系统之后,结构地震动力反应的层间位移大幅减少.当辊轴截面偏心距为20~30mm、滚动摩擦系数为0.01左右时,隔震系统具有较好的消能效果与复位能力.当竖向层间刚度系数为水平层间刚度系数的10倍以上时,可以不考虑竖向刚度对水平方向隔震效果的影响.%A theoretical analyzing approach about a novel seismic isolation system, ERFPS (Eccentric Rolling Friction Pendulum System), is derived. It starts from the relative kinematics energy theorem in multiply-body dynamics, including the effect of inter-storey rigidity coefficient in the vertical direction. Computation results show that ERFPS has three kinds of necessary capability required for an effective isolation system. When the eccentricity is in the range of 20 ~ 30mm and the rolling friction coefficient is about 0. 01, the ERFPS system possesses both good energy dissipation and good reposition capability. If the vertical inter-storey rigidity coefficient is above 1O times greater than the horizontal inter-storey rigidity coefficient, for a practical range of rolling frictional coefficient the influence of vertical rigidity could be neglected.

  4. Large scale mechanical metamaterials as seismic shields

    Science.gov (United States)

    Miniaci, Marco; Krushynska, Anastasiia; Bosia, Federico; Pugno, Nicola M.

    2016-08-01

    Earthquakes represent one of the most catastrophic natural events affecting mankind. At present, a universally accepted risk mitigation strategy for seismic events remains to be proposed. Most approaches are based on vibration isolation of structures rather than on the remote shielding of incoming waves. In this work, we propose a novel approach to the problem and discuss the feasibility of a passive isolation strategy for seismic waves based on large-scale mechanical metamaterials, including for the first time numerical analysis of both surface and guided waves, soil dissipation effects, and adopting a full 3D simulations. The study focuses on realistic structures that can be effective in frequency ranges of interest for seismic waves, and optimal design criteria are provided, exploring different metamaterial configurations, combining phononic crystals and locally resonant structures and different ranges of mechanical properties. Dispersion analysis and full-scale 3D transient wave transmission simulations are carried out on finite size systems to assess the seismic wave amplitude attenuation in realistic conditions. Results reveal that both surface and bulk seismic waves can be considerably attenuated, making this strategy viable for the protection of civil structures against seismic risk. The proposed remote shielding approach could open up new perspectives in the field of seismology and in related areas of low-frequency vibration damping or blast protection.

  5. Seismic design technology for Breeder Reactor structures. Volume 3: special topics in reactor structures

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, D.P. (ed)

    1983-04-01

    This volume is divided into six chapters: analysis techniques, equivalent damping values, probabilistic design factors, design verifications, equivalent response cycles for fatigue analysis, and seismic isolation. (JDB)

  6. Isolation and identification of novel genes involved in artemisinin production from flowers of Artemisia annua using suppression subtractive hybridization and metabolite analysis.

    Science.gov (United States)

    Liu, Shuoqian; Tian, Na; Li, Juan; Huang, Jianan; Liu, Zhonghua

    2009-11-01

    Malaria is a global health problem that threatens 300-500 million people and kills more than one million people annually. Artemisinin is highly effective against multidrug-resistant Plasmodium falciparum and it has been widely used as part of the artemisinin-based combination therapies against malaria. To elucidate the biosynthetic pathway of artemisinin and to clone related genes in Artemisia annua, differentially expressed genes between blooming flowers and flower buds were isolated and characterized by a combined approach of suppression subtractive hybridization (SSH) and metabolite analysis. A total of 350 cDNA clones from a subtractive cDNA library were randomly picked, sequenced and analyzed and 253 high-quality sequences were obtained. BLASTX comparisons indicated that about 9.9 % of the clones encoded enzymes involved in isoprenoid (including artemisinin) biosynthesis. The expression of 4 gene transcripts involved in artemisinin biosynthesis was examined by RT-PCR and the results confirmed the higher expression of these transcripts in blooming flowers than in flower buds. In addition, 2 putative transcript factors transparenta testa glabra 1 (TTG1) and ENHANCER OF GLABRA3 (GL3), which promote trichome initiation, were presented in the library. Finally, this study demonstrated that the increase of expression level of the putative TTG1 gene correlated with the improvement of glandular trichome density and artemisinin production in A. annua leaves. The subtractive cDNA library described in the present study provides important candidate genes for future research in order to increase the artemisinin content in A. annua.

  7. [Evaluation of peptide nucleic acid fluorescent in situ hybridization (PNA FISH) method in the identifi cation of Candida species isolated from blood cultures].

    Science.gov (United States)

    Aydemir, Gonca; Koç, Ayşe Nedret; Atalay, Mustafa Altay

    2016-04-01

    In recent years, increased number of patients who are hospitalized in intensive care units, received immunosuppressive therapy and treated with broad-spectrum antibiotics that can lead an increase in the incidence of systemic candidiasis. In these patients, the most common clinical manifestation is candidemia. Since the identification of Candida species isolated from blood cultures is time consuming by conventional (morphological and biochemical) methods, rapid, reliable and accurate methods are needed. For this purpose novel systems have been developed to identify the agent directly. The aim of this study was to evaluate the peptide nucleic acid fluorescent in situ hybridization (PNA FISH) method for the identification of Candida species by comparing with the conventional methods. A total of 50 patients who were admitted to Erciyes University Medical Faculty Hospital clinics and followed with prediagnosis of systemic fungal infections whose blood cultures were positive for the yeasts between July 2011 and July 2012 were included in the study. The conventional identification of Candida isolates was performed by considering macroscopic and microscopic morphology, germ tube test, cycloheximide sensitivity, urease activity and carbohydrate assimilation patterns with API 20C AUX (bioMerieux, France) test. PNA FISH method was conducted by the use of a commercial kit namely Yeast Traffic Light(®) PNA FISH (AdvanDx, USA). According to morphological and biochemical characteristics (conventional methods), 19 (38%) out of 50 Candida isolates were identified as C.albicans, 12 (24%) as C.glabrata, five (10%) as C.parapsilosis, five (10%) as C.kefyr, four (8%) as C.krusei, two (4%) as C.guilliermondii, two (4%) as C.tropicalis and one (2%) as C.lusitaniae. On the other hand, 24 (48%) of the isolates were identified as C.albicans/C.parapsilosis (with green fluorescence), 16 (32%) as C.glabrata/C.krusei (with red fluorescence) and one (%2) as C.tropicalis (with yellow

  8. Quantitative Seismic Amplitude Analysis

    NARCIS (Netherlands)

    Dey, A.K.

    2011-01-01

    The Seismic Value Chain quantifies the cyclic interaction between seismic acquisition, imaging and reservoir characterization. Modern seismic innovation to address the global imbalance in hydrocarbon supply and demand requires such cyclic interaction of both feed-forward and feed-back processes.

  9. Quantitative Seismic Amplitude Analysis

    NARCIS (Netherlands)

    Dey, A.K.

    2011-01-01

    The Seismic Value Chain quantifies the cyclic interaction between seismic acquisition, imaging and reservoir characterization. Modern seismic innovation to address the global imbalance in hydrocarbon supply and demand requires such cyclic interaction of both feed-forward and feed-back processes. Cur

  10. Robotization in Seismic Acquisition

    NARCIS (Netherlands)

    Blacquière, G.; Berkhout, A.J.

    2013-01-01

    The amount of sources and detectors in the seismic method follows "Moore’s Law of seismic data acquisition", i.e., it increases approximately by a factor of 10 every 10 years. Therefore automation is unavoidable, leading to robotization of seismic data acquisition. Recently, we introduced a new

  11. Hybridization and extinction.

    Science.gov (United States)

    Todesco, Marco; Pascual, Mariana A; Owens, Gregory L; Ostevik, Katherine L; Moyers, Brook T; Hübner, Sariel; Heredia, Sylvia M; Hahn, Min A; Caseys, Celine; Bock, Dan G; Rieseberg, Loren H

    2016-08-01

    Hybridization may drive rare taxa to extinction through genetic swamping, where the rare form is replaced by hybrids, or by demographic swamping, where population growth rates are reduced due to the wasteful production of maladaptive hybrids. Conversely, hybridization may rescue the viability of small, inbred populations. Understanding the factors that contribute to destructive versus constructive outcomes of hybridization is key to managing conservation concerns. Here, we survey the literature for studies of hybridization and extinction to identify the ecological, evolutionary, and genetic factors that critically affect extinction risk through hybridization. We find that while extinction risk is highly situation dependent, genetic swamping is much more frequent than demographic swamping. In addition, human involvement is associated with increased risk and high reproductive isolation with reduced risk. Although climate change is predicted to increase the risk of hybridization-induced extinction, we find little empirical support for this prediction. Similarly, theoretical and experimental studies imply that genetic rescue through hybridization may be equally or more probable than demographic swamping, but our literature survey failed to support this claim. We conclude that halting the introduction of hybridization-prone exotics and restoring mature and diverse habitats that are resistant to hybrid establishment should be management priorities.

  12. Seismic Location Station for Detection of Unobserved Moving Military Machineries

    OpenAIRE

    Bayramov, Azad; Hashimov, Elshan

    2016-01-01

    The main purpose of this paper is to develop a seismic location station that can detect unobserved, moving military objects, and heavy military machineries behind a forest or a mountain at a distance of 1-2 kilometers from the determined location. Seismic location station includes specific 3D seismic detectors based on the very sensible piezoelectric sensors. The proposed piezoelectric detectors are based on the PVDF+BaTiO3+PZT polymer hybrid composite fabricated based on nano sized BaTiO3 (o...

  13. Angola Seismicity MAP

    Science.gov (United States)

    Neto, F. A. P.; Franca, G.

    2014-12-01

    The purpose of this job was to study and document the Angola natural seismicity, establishment of the first database seismic data to facilitate consultation and search for information on seismic activity in the country. The study was conducted based on query reports produced by National Institute of Meteorology and Geophysics (INAMET) 1968 to 2014 with emphasis to the work presented by Moreira (1968), that defined six seismogenic zones from macro seismic data, with highlighting is Zone of Sá da Bandeira (Lubango)-Chibemba-Oncócua-Iona. This is the most important of Angola seismic zone, covering the epicentral Quihita and Iona regions, geologically characterized by transcontinental structure tectono-magmatic activation of the Mesozoic with the installation of a wide variety of intrusive rocks of ultrabasic-alkaline composition, basic and alkaline, kimberlites and carbonatites, strongly marked by intense tectonism, presenting with several faults and fractures (locally called corredor de Lucapa). The earthquake of May 9, 1948 reached intensity VI on the Mercalli-Sieberg scale (MCS) in the locality of Quihita, and seismic active of Iona January 15, 1964, the main shock hit the grade VI-VII. Although not having significant seismicity rate can not be neglected, the other five zone are: Cassongue-Ganda-Massano de Amorim; Lola-Quilengues-Caluquembe; Gago Coutinho-zone; Cuima-Cachingues-Cambândua; The Upper Zambezi zone. We also analyzed technical reports on the seismicity of the middle Kwanza produced by Hidroproekt (GAMEK) region as well as international seismic bulletins of the International Seismological Centre (ISC), United States Geological Survey (USGS), and these data served for instrumental location of the epicenters. All compiled information made possible the creation of the First datbase of seismic data for Angola, preparing the map of seismicity with the reconfirmation of the main seismic zones defined by Moreira (1968) and the identification of a new seismic

  14. Base isolation of fluid containers

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. [Cygna Group Inc./ICF Kaiser International, Oakland, CA (United States)

    1995-12-01

    Fluid containers often constitute critical internal equipment in power plants. However, due to possible structure-equipment interaction effect they are particularly vulnerable during strong earthquake events. An effective technique for protecting fluid containers is base isolation. By deflecting the possible seismic input energy into the superstructure, base isolation can substantially reduce seismic demand on the containers, making it more cost effective than equivalent conventional design.

  15. On the isolation of elemental carbon (EC for micro-molar 14C accelerator mass spectrometry: development of a hybrid reference material for 14C-EC accuracy assurance, and a critical evaluation of the thermal optical kinetic (TOK EC isolation procedure

    Directory of Open Access Journals (Sweden)

    L. A. Currie

    2005-01-01

    Full Text Available The primary objective of the research reported here has been the development of a hybrid reference material (RM to serve as a test of accuracy for elemental carbon (EC isotopic (14C speciation measurements. Such measurements are vital for the quantitative apportionment of fossil and biomass sources of 'soot' (EC, the tracer of fire that has profound effects on health, atmospheric visibility, and climate. Previous studies of 14C-EC measurement quality, carried out with NIST SRM 1649a (Urban Dust, showed a range of results, but since the 'truth' was not known for this natural matrix RM, one had to rely on isotopic-chemical consistency evidence (14C in PAH, EC of measurement validity (Currie et al., 2002. Components of the new Hybrid RM (DiesApple, however, have known 14C and EC composition, and they are nearly orthogonal (isotopically and chemically. NIST SRM 2975 (Forklift Diesel Soot has little or no 14C, and its major compositional component is EC; SRM 1515 (Apple Leaves has the 14C content of biomass-C, and it has little or no EC. Thus, the Hybrid RM can serve as an absolute isotopic test for the absence of EC-mimicking pyrolysis-C (char from SRM 1515 in the EC isolate of the Hybrid RM, as well as a test for conservation of its dominant soot fraction throughout the isolation procedure. The secondary objective was to employ the Hybrid RM for the comparative evaluation of the thermal optical kinetic (TOK and thermal optical transmission (TOT methods for the isolation of EC for micro-molar carbon accelerator mass spectrometry (AMS. As part of this process, the relatively new TOK method was subjected to a critical evaluation and significant development. Key findings of our study are: (1 both methods exhibited biomass-C 'leakage'; for TOT, the EC fraction isolated for AMS contained about 8% of the original biomass-C; for TOK, the refractory carbon (RC isolated contained about 3% of the original biomass-C.; (2 the initial isothermal oxidation stage

  16. Simplified seismic risk analysis

    Energy Technology Data Exchange (ETDEWEB)

    Pellissetti, Manuel; Klapp, Ulrich [AREVA NP GmbH, Erlangen (Germany)

    2011-07-01

    Within the context of probabilistic safety analysis (PSA) for nuclear power plants (NPP's), seismic risk assessment has the purpose to demonstrate that the contribution of seismic events to overall risk is not excessive. The most suitable vehicle for seismic risk assessment is a full scope seismic PSA (SPSA), in which the frequency of core damage due to seismic events is estimated. An alternative method is represented by seismic margin assessment (SMA), which aims at showing sufficient margin between the site-specific safe shutdown earthquake (SSE) and the actual capacity of the plant. Both methods are based on system analysis (fault-trees and event-trees) and hence require fragility estimates for safety relevant systems, structures and components (SSC's). If the seismic conditions at a specific site of a plant are not very demanding, then it is reasonable to expect that the risk due to seismic events is low. In such cases, the cost-benefit ratio for performing a full scale, site-specific SPSA or SMA will be excessive, considering the ultimate objective of seismic risk analysis. Rather, it will be more rational to rely on a less comprehensive analysis, used as a basis for demonstrating that the risk due to seismic events is not excessive. The present paper addresses such a simplified approach to seismic risk assessment which is used in AREVA to: - estimate seismic risk in early design stages, - identify needs to extend the design basis, - define a reasonable level of seismic risk analysis Starting from a conservative estimate of the overall plant capacity, in terms of the HCLPF (High Confidence of Low Probability of Failure), and utilizing a generic value for the variability, the seismic risk is estimated by convolution of the hazard and the fragility curve. Critical importance is attached to the selection of the plant capacity in terms of the HCLPF, without performing extensive fragility calculations of seismically relevant SSC's. A suitable basis

  17. Seismic Catalogue and Seismic Network in Haiti

    Science.gov (United States)

    Belizaire, D.; Benito, B.; Carreño, E.; Meneses, C.; Huerfano, V.; Polanco, E.; McCormack, D.

    2013-05-01

    The destructive earthquake occurred on January 10, 2010 in Haiti, highlighted the lack of preparedness of the country to address seismic phenomena. At the moment of the earthquake, there was no seismic network operating in the country, and only a partial control of the past seismicity was possible, due to the absence of a national catalogue. After the 2010 earthquake, some advances began towards the installation of a national network and the elaboration of a seismic catalogue providing the necessary input for seismic Hazard Studies. This paper presents the state of the works carried out covering both aspects. First, a seismic catalogue has been built, compiling data of historical and instrumental events occurred in the Hispaniola Island and surroundings, in the frame of the SISMO-HAITI project, supported by the Technical University of Madrid (UPM) and Developed in cooperation with the Observatoire National de l'Environnement et de la Vulnérabilité of Haiti (ONEV). Data from different agencies all over the world were gathered, being relevant the role of the Dominican Republic and Puerto Rico seismological services which provides local data of their national networks. Almost 30000 events recorded in the area from 1551 till 2011 were compiled in a first catalogue, among them 7700 events with Mw ranges between 4.0 and 8.3. Since different magnitude scale were given by the different agencies (Ms, mb, MD, ML), this first catalogue was affected by important heterogeneity in the size parameter. Then it was homogenized to moment magnitude Mw using the empirical equations developed by Bonzoni et al (2011) for the eastern Caribbean. At present, this is the most exhaustive catalogue of the country, although it is difficult to assess its degree of completeness. Regarding the seismic network, 3 stations were installed just after the 2010 earthquake by the Canadian Government. The data were sent by telemetry thought the Canadian System CARINA. In 2012, the Spanish IGN together

  18. Isolation and characterization of a metastatic hybrid cell line generated by ER negative and ER positive breast cancer cells in mouse bone marrow.

    Directory of Open Access Journals (Sweden)

    Keya De Mukhopadhyay

    Full Text Available BACKGROUND: The origin and the contribution of breast tumor heterogeneity to its progression are not clear. We investigated the effect of a growing orthotopic tumor formed by an aggressive estrogen receptor (ER-negative breast cancer cell line on the metastatic potential of a less aggressive ER-positive breast cancer cell line for the elucidation of how the presence of heterogeneous cancer cells might affect each other's metastatic behavior. METHODS: ER positive ZR-75-1/GFP/puro cells, resistant to puromycin and non-tumorigenic/non-metastatic without exogenous estrogen supplementation, were injected intracardiacally into mice bearing growing orthotopic tumors, formed by ER negative MDA-MB-231/GFP/Neo cells resistant to G418. A variant cell line B6, containing both estrogen-dependent and -independent cells, were isolated from GFP expressing cells in the bone marrow and re-inoculated in nude mice to generate an estrogen-independent cell line B6TC. RESULTS: The presence of ER negative orthotopic tumors resulted in bone metastasis of ZR-75-1 without estrogen supplementation. The newly established B6TC cell line was tumorigenic without estrogen supplementation and resistant to both puromycin and G418 suggesting its origin from the fusion of MDA-MB-231/GFP/Neo and ZR-75-1/GFP/puro in the mouse bone marrow. Compared to parental cells, B6TC cells were more metastatic to lung and bone after intracardiac inoculation. More significantly, B6TC mice also developed brain metastasis, which was not observed in the MDA-MB-231/GFP/Neo cell-inoculated mice. Low expression of ERα and CD24, and high expression of EMT-related markers such as Vimentin, CXCR4, and Integrin-β1 along with high CD44 and ALDH expression indicated stem cell-like characteristics of B6TC. Gene microarray analysis demonstrated a significantly different gene expression profile of B6TC in comparison to those of parental cell lines. CONCLUSIONS: Spontaneous generation of the novel hybrid cell

  19. Study on Seismic Behavior of the Frame-Bent Hybrid Structure of SRC Columns-RC Shear Walls forthe Main Building of Thermal Power Plants%火电厂主厂房SRC柱-RC分散剪力墙框排架混合结构抗震性能研究

    Institute of Scientific and Technical Information of China (English)

    刘志钦; 白国良; 李红星; 赵春莲

    2013-01-01

    火电厂主厂房因承载的设备种类繁多,运行参数复杂,使其质量、刚度在空间和平面上分布不均匀,导致结构体系的抗震性能较差.以8度区Ⅱ类场地,单机容量1000MW机组的主厂房为研究对象,提出SRC柱-RC分散剪力墙框排架混合结构,对荷重较大的三榀子结构按1/7缩尺设计制作的模型结构,进行抗震性能试验研究,得到不同加速度峰值地震波作用下结构的荷载和位移反应,SRC柱、RC分散剪力墙的协同受力及多道抗震防线的形成规律等,并对结构在8度地震作用下的动力弹塑性分析进行对比,其结果表明该结构体系满足8度小震不坏、大震不倒的抗震设防要求,具有良好的变形性能,SRC柱与RC分散剪力墙有较好的协同工作性能,设置的RC剪力墙完美起到了第一道抗震防线作用,说明SRC柱-RC分散剪力墙框排架混合结构主厂房宜于在高烈度区大容量机组主厂房中推广应用.%As the structure of main building has many types of electric equipment, running complex parameters, with the structure system so uneven distribution of mass and stiffness has poor seismic behavior. Taking the main building with unit capacity 1000MW and at 8 degree intensity site II as research object, SCR column and RC dispersed shear wall frame-bent hybrid structural system is put forward. Three Substructures are selected and the model according to 1/7 reduced scale design is made, study to the seismic behavior. The load and displacement in different seismic waves, the coordinated working of SCR column and RC dispersed shear wall, the formation rule of multiple aseismic lines are obtained. Furthermore, the testing results are compared with the dynamic elastic-plastic analyses of model in 8 degree earthquake. The results show that the structural system can meet the needs of design in zone with the seismic fortification intensity 8, SRC frame and RC shear wall have better deformation performance and

  20. Participation in sizing methods and management improvement for the isolated hybrid systems coupling photovoltaic generator and power generating unit. Application in developing countries; Participation a l'amelioration des methodes de dimensionnement et de gestion pour les systemes isoles hybrides de production d'electricite, couplant generateur photovoltaique et groupe electrogene. Application dans les pays en voie de developpement

    Energy Technology Data Exchange (ETDEWEB)

    Camez, C.

    2004-09-15

    One of the applications justifying more the use of renewable energies is the electrification of isolated sites. Sites for which connection to the local distribution network is being out of price or impossible. These sites are most of the time electrified with a diesel generator. This technology is tested and mature however two major disadvantages can be raised here: necessary routine maintenance and the fuel provisioning management. Photovoltaic system can answer here the request and little solar home systems (100 Watts) are installed. In the particular situation of a village electrification, the consumers quickly see in these systems a strong limitation with the development. Reliability, evolution, comfort, service are the masters words here, the development of a micro industry also seems necessary to a village development. It is then necessary to propose a micro network type solution. Such a generator cannot be think completely photovoltaic, presenting an important over-cost compared to a conventional solution. The idea of conventional and renewable energy coupling is born. Such a multi-source system: hybrid, implies an increased sizing and management complexity. An analysis software tool was developed: HYPSIM, this one makes it possible to optimize the operation of such a system. HYPSIM made possible to - Justify the relevance of a photovoltaic/diesel generator/batteries system. - Conclude on the sizing criteria to be observed. (author)

  1. Imaging seismic reflections

    NARCIS (Netherlands)

    Op 't Root, Timotheus Johannes Petrus Maria

    2011-01-01

    The goal of reflection seismic imaging is making images of the Earth subsurface using surface measurements of reflected seismic waves. Besides the position and orientation of subsurface reflecting interfaces it is a challenge to recover the size or amplitude of the discontinuities. We investigate tw

  2. SOAR Telescope seismic performance II: seismic mitigation

    Science.gov (United States)

    Elias, Jonathan H.; Muñoz, Freddy; Warner, Michael; Rivera, Rossano; Martínez, Manuel

    2016-07-01

    We describe design modifications to the SOAR telescope intended to reduce the impact of future major earthquakes, based on the facility's experience during recent events, most notably the September 2015 Illapel earthquake. Specific modifications include a redesign of the encoder systems for both azimuth and elevation, seismic trigger for the emergency stop system, and additional protections for the telescope secondary mirror system. The secondary mirror protection may combine measures to reduce amplification of seismic vibration and "fail-safe" components within the assembly. The status of these upgrades is presented.

  3. Seismic texture classification. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Vinther, R.

    1997-12-31

    The seismic texture classification method, is a seismic attribute that can both recognize the general reflectivity styles and locate variations from these. The seismic texture classification performs a statistic analysis for the seismic section (or volume) aiming at describing the reflectivity. Based on a set of reference reflectivities the seismic textures are classified. The result of the seismic texture classification is a display of seismic texture categories showing both the styles of reflectivity from the reference set and interpolations and extrapolations from these. The display is interpreted as statistical variations in the seismic data. The seismic texture classification is applied to seismic sections and volumes from the Danish North Sea representing both horizontal stratifications and salt diapers. The attribute succeeded in recognizing both general structure of successions and variations from these. Also, the seismic texture classification is not only able to display variations in prospective areas (1-7 sec. TWT) but can also be applied to deep seismic sections. The seismic texture classification is tested on a deep reflection seismic section (13-18 sec. TWT) from the Baltic Sea. Applied to this section the seismic texture classification succeeded in locating the Moho, which could not be located using conventional interpretation tools. The seismic texture classification is a seismic attribute which can display general reflectivity styles and deviations from these and enhance variations not found by conventional interpretation tools. (LN)

  4. Hybrid regression trees applied to the monitoring of dynamic safety of isolated networks with large eolic production contribution; Utilizacao de arvores de regressao hibridas na monitorizacao da seguranca dinamica de redes isoladas com grande producao eolica

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, J.A Pecas; Vasconcelos, Maria Helena O.P. de [Instituto de Engenharia de Sistemas e Computadores (INESC), Porto (Portugal). E-mail: jpl@riff.fe.up.pt; hvasconcelos@inescn.pt

    1999-07-01

    This paper describes in a synthetic manner the technology adopted to define structures used in the fast evaluation of dynamic safety of isolated network with high level of eolic production contribution. This methodology uses hybrid regression trees, which allows the quantification the endurance connected to the dynamic behavior of these networks by emulating the frequency minimum deviation that will be experienced by the system when submitted toa pre-defined perturbation. Also, new procedures for data automatic generation are presented, which will be used for construction and measurements of the evaluation structures performance. The paper describes the Terceira island - Acores archipelago network study case.

  5. 杂交鳢海豚链球菌病病原分离鉴定及药敏试验%Isolation and identification of pathogen Streptococcus iniae in diseased hybrid snakehead (Channa argus♂× Channamaculata♀)

    Institute of Scientific and Technical Information of China (English)

    陈言峰; 周爱国; 邹青; 陈冠锋; 陈建酬; 张继平; 张辉华

    2015-01-01

    【目的】对广东省中山市某养殖场的患病濒死杂交鳢进行病原分离鉴定及药敏试验,旨在确定病因,为今后生产中有效防控该病提供参考。【方法】从濒死杂交鳢体内分离致病菌,通过其生理生化特征与16S rRNA基因序列分析进行菌株鉴定,并采用纸片扩散法进行药敏试验。【结果】从患病濒死的杂交鳢体内分离获得两株优势菌(ZS2013711-1和ZS2013711-2),根据其生理生化鉴定结果与16S rRNA基因序列分析结果,可鉴定为海豚链球菌(Streptococcusiniae)。两株分离菌株对杂交鳢的半致死剂量(LD50)分别为2.7×105和6.7×105 CFU/g。药敏试验结果显示,该致病菌对头孢噻肟、头孢拉定、头孢唑啉、林可霉素等抗生素高度敏感。【结论】杂交鳢是海豚链球菌的一种新发现宿主,生产中可选用头孢噻肟、头孢拉定、头孢唑啉、林可霉素等药物进行防治。%Objective]The pathogens from diseased hybrid snakehead (Channa argus♂×Channa maculata♀) in an aquafarm in Zhongshan City of Guangdong Province were isolated and identified and antibiotic sensitivity test was per-formed in order to determine the causes and provide references for preventing and controlling this disease effectively.[Method]Pathogenic bacteria were isolated from moribund hybrid snakehead , and they were identified through physio-logical and biochemical characteristics test and 16S rRNA sequence analysis. Furthermore , antibiotic sensitivity test was performed through Kirby-Bauer disk diffusion method. [Result]Two dominant bacterias (ZS2013711-1, ZS2013711-2) were isolated from moribund hybrid snakehead , and they were identified to be Streptococcus iniae according to their physiological and biochemical characteristics and 16S rRNA sequence analysis. The half lethal dose values for the iso-lates to healthy hybrid snakehead were 2.7 ×105 and 6.7 ×105 CFU/g, respectively. The results of

  6. The challenging requirements of the ITER anti seismic bearings

    Energy Technology Data Exchange (ETDEWEB)

    Syed, M.B., E-mail: MahaboobBasha.SYED@iter.org [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Patisson, L. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Curtido, M.; Slee, B. [Fusion for Energy, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Diaz, S. [Nuvia Travaux Speciaux, 92 Cours Vitton, 69006 Lyon (France)

    2014-04-01

    ITER is being designed and constructed with a high level of safety as an essential requirement. In order to meet the safety and performance objectives of ITER and the French regulatory requirements, the Tokamak Complex has been isolated from the potential seismic hazard by anti-seismic bearings. The dynamic characteristics of the anti-seismic bearings were chosen so that the Tokamak Complex will have a fundamental horizontal frequency of 0.55 Hz. The design, manufacturing and qualification of ASBs have been carried out by NUVIA Travaux Speciaux with specific ITER requirements that are much more stringent than the applicable European and French Norms and directives.

  7. Complex seismic wavefi eld interpolation based on the Bregman iteration method in the sparse transform domain

    Institute of Scientific and Technical Information of China (English)

    Gou Fu-Yan; Liu Cai; Liu Yang; Feng Xuan; Cui Fang-Zi

    2014-01-01

    In seismic prospecting,fi eld conditions and other factors hamper the recording of the complete seismic wavefi eld; thus, data interpolation is critical in seismic data processing. Especially, in complex conditions, prestack missing data affect the subsequent high-precision data processing workfl ow. Compressive sensing is an effective strategy for seismic data interpolation by optimally representing the complex seismic wavefi eld and using fast and accurate iterative algorithms. The seislet transform is a sparse multiscale transform well suited for representing the seismic wavefield, as it can effectively compress seismic events. Furthermore, the Bregman iterative algorithm is an efficient algorithm for sparse representation in compressive sensing. Seismic data interpolation methods can be developed by combining seismic dynamic prediction, image transform, and compressive sensing. In this study, we link seismic data interpolation and constrained optimization. We selected the OC-seislet sparse transform to represent complex wavefields and used the Bregman iteration method to solve the hybrid norm inverse problem under the compressed sensing framework. In addition, we used an H-curve method to choose the threshold parameter in the Bregman iteration method. Thus, we achieved fast and accurate reconstruction of the seismic wavefi eld. Model andfi eld data tests demonstrate that the Bregman iteration method based on the H-curve norm in the sparse transform domain can effectively reconstruct missing complex wavefi eld data.

  8. The Seismic Wavefield

    Science.gov (United States)

    Kennett, B. L. N.

    2002-12-01

    The two volumes of The Seismic Wavefield are a comprehensive guide to the understanding of seismograms in terms of physical propagation processes within the Earth. The focus is on the observation of earthquakes and man-made sources on all scales, for both body waves and surface waves. Volume I provides a general introduction and a development of the theoretical background for seismic waves. Volume II looks at the way in which observed seismograms relate to the propagation processes. Volume II also discusses local and regional seismic events, global wave propagation, and the three-dimensional Earth.

  9. Research on seismic stress triggering

    Institute of Scientific and Technical Information of China (English)

    万永革; 吴忠良; 周公威; 黄静; 秦立新

    2002-01-01

    This paper briefly reviews basic theory of seismic stress triggering. Recent development on seismic stress triggering has been reviewed in the views of seismic static and dynamic stress triggering, application of viscoelastic model in seismic stress triggering, the relation between earthquake triggering and volcanic eruption or explosion, other explanation of earthquake triggering, etc. And some suggestions for further study on seismic stress triggering in near future are given.

  10. 2.3-MW Medium-Voltage, Three-Level Wind Energy Inverter Applying a Unique Bus Structure and 4.5-kV Si/SiC Hybrid Isolated Power Modules: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Erdman, W.; Keller, J.; Grider, D.; VanBrunt, E.

    2014-11-01

    A high-efficiency, 2.3-MW, medium-voltage, three-level inverter utilizing 4.5-kV Si/SiC (silicon carbide) hybrid modules for wind energy applications is discussed. The inverter addresses recent trends in siting the inverter within the base of multimegawatt turbine towers. A simplified split, three-layer laminated bus structure that maintains low parasitic inductances is introduced along with a low-voltage, high-current test method for determining these inductances. Feed-thru bushings, edge fill methods, and other design features of the laminated bus structure provide voltage isolation that is consistent with the 10.4-kV module isolation levels. Inverter efficiency improvement is a result of the (essential) elimination of the reverse recovery charge present in 4.5-kV Si PIN diodes, which can produce a significant reduction in diode turn-off losses as well as insulated-gate bipolar transistor (IGBT) turn-on losses. The hybrid modules are supplied in industry-standard 140 mm x 130 mm and 190 mm x 130 mm packages to demonstrate direct module substitution into existing inverter designs. A focus on laminated bus/capacitor-bank/module subassembly level switching performance is presented.

  11. Suppression subtractive hybridization (SSH) for isolation and characterization of genes related to testicular development in the giant tiger shrimp Penaeus monodon.

    Science.gov (United States)

    Leelatanawit, Rungnapa; Klinbunga, Sirawut; Aoki, Takashi; Hirono, Ikuo; Valyasevi, Rudd; Menasveta, Piamsak

    2008-11-30

    Suppression subtractive hybridization (SSH) cDNA libraries of the giant tiger shrimp, Penaeus monodon, were constructed. In total, 178 and 187 clones from the forward and reverse SSH libraries, respectively, of P. monodon were unidirectionally sequenced. From these, 37.1% and 53.5% Expressed Sequence Tags (ESTs) significantly matched known genes (E-value 0.05).

  12. Reproducibility in Seismic Imaging

    Directory of Open Access Journals (Sweden)

    González-Verdejo O.

    2012-04-01

    Full Text Available Within the field of exploration seismology, there is interest at national level of integrating reproducibility in applied, educational and research activities related to seismic processing and imaging. This reproducibility implies the description and organization of the elements involved in numerical experiments. Thus, a researcher, teacher or student can study, verify, repeat, and modify them independently. In this work, we document and adapt reproducibility in seismic processing and imaging to spread this concept and its benefits, and to encourage the use of open source software in this area within our academic and professional environment. We present an enhanced seismic imaging example, of interest in both academic and professional environments, using Mexican seismic data. As a result of this research, we prove that it is possible to assimilate, adapt and transfer technology at low cost, using open source software and following a reproducible research scheme.

  13. Seismic Fault Preserving Diffusion

    CERN Document Server

    Lavialle, Olivier; Germain, Christian; Donias, Marc; Guillon, Sebastien; Keskes, Naamen; Berthoumieu, Yannick

    2007-01-01

    This paper focuses on the denoising and enhancing of 3-D reflection seismic data. We propose a pre-processing step based on a non linear diffusion filtering leading to a better detection of seismic faults. The non linear diffusion approaches are based on the definition of a partial differential equation that allows us to simplify the images without blurring relevant details or discontinuities. Computing the structure tensor which provides information on the local orientation of the geological layers, we propose to drive the diffusion along these layers using a new approach called SFPD (Seismic Fault Preserving Diffusion). In SFPD, the eigenvalues of the tensor are fixed according to a confidence measure that takes into account the regularity of the local seismic structure. Results on both synthesized and real 3-D blocks show the efficiency of the proposed approach.

  14. Seismic fault preserving diffusion

    Science.gov (United States)

    Lavialle, Olivier; Pop, Sorin; Germain, Christian; Donias, Marc; Guillon, Sebastien; Keskes, Naamen; Berthoumieu, Yannick

    2007-02-01

    This paper focuses on the denoising and enhancing of 3-D reflection seismic data. We propose a pre-processing step based on a non-linear diffusion filtering leading to a better detection of seismic faults. The non-linear diffusion approaches are based on the definition of a partial differential equation that allows us to simplify the images without blurring relevant details or discontinuities. Computing the structure tensor which provides information on the local orientation of the geological layers, we propose to drive the diffusion along these layers using a new approach called SFPD (Seismic Fault Preserving Diffusion). In SFPD, the eigenvalues of the tensor are fixed according to a confidence measure that takes into account the regularity of the local seismic structure. Results on both synthesized and real 3-D blocks show the efficiency of the proposed approach.

  15. BUILDING 341 Seismic Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Halle, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-06-15

    The Seismic Evaluation of Building 341 located at Lawrence Livermore National Laboratory in Livermore, California has been completed. The subject building consists of a main building, Increment 1, and two smaller additions; Increments 2 and 3.

  16. Analysis of infant isolates of Bifidobacterium breve by comparative genome hybridization indicates the existence of new subspecies with marked infant specificity

    NARCIS (Netherlands)

    Boesten, R.; Schuren, F.; Wind, R.D.; Knol, J.; Vos, W.M. de

    2011-01-01

    A total of 20 Bifidobacterium strains were isolated from fecal samples of 4 breast- and bottle-fed infants and all were characterized as Bifidobacterium breve based on 16S rRNA gene sequence and metabolic analysis. These isolates were further characterized and compared to the type strains of B. brev

  17. Seismic facies; Facies sismicas

    Energy Technology Data Exchange (ETDEWEB)

    Johann, Paulo Roberto Schroeder [PETROBRAS, Rio de Janeiro, RJ (Brazil). Exploracao e Producao Corporativo. Gerencia de Reservas e Reservatorios]. E-mail: johann@petrobras.com.br

    2004-11-01

    The method presented herein describes the seismic facies as representations of curves and vertical matrixes of the lithotypes proportions. The seismic facies are greatly interested in capturing the spatial distributions (3D) of regionalized variables, as for example, lithotypes, sedimentary facies groups and/ or porosity and/or other properties of the reservoirs and integrate them into the 3D geological modeling (Johann, 1997). Thus when interpreted as curves or vertical matrixes of proportions, seismic facies allow us to build a very important tool for structural analysis of regionalized variables. The matrixes have an important application in geostatistical modeling. In addition, this approach provides results about the depth and scale of the wells profiles, that is, seismic data is integrated to the characterization of reservoirs in depth maps and in high resolution maps. The link between the different necessary technical phases involved in the classification of the segments of seismic traces is described herein in groups of predefined traces of two approaches: a) not supervised and b) supervised by the geological knowledge available on the studied reservoir. The multivariate statistical methods used to obtain the maps of the seismic facies units are interesting tools to be used to provide a lithostratigraphic and petrophysical understanding of a petroleum reservoir. In the case studied these seismic facies units are interpreted as representative of the depositional system as a part of the Namorado Turbiditic System, Namorado Field, Campos Basin.Within the scope of PRAVAP 19 (Programa Estrategico de Recuperacao Avancada de Petroleo - Strategic Program of Advanced Petroleum Recovery) some research work on algorithms is underway to select new optimized attributes to apply seismic facies. One example is the extraction of attributes based on the wavelet transformation and on the time-frequency analysis methodology. PRAVAP is also carrying out research work on an

  18. Hybrid Baryons

    CERN Document Server

    Page, P R

    2003-01-01

    We review the status of hybrid baryons. The only known way to study hybrids rigorously is via excited adiabatic potentials. Hybrids can be modelled by both the bag and flux-tube models. The low-lying hybrid baryon is N 1/2^+ with a mass of 1.5-1.8 GeV. Hybrid baryons can be produced in the glue-rich processes of diffractive gamma N and pi N production, Psi decays and p pbar annihilation.

  19. Seismic Consequence Abstraction

    Energy Technology Data Exchange (ETDEWEB)

    M. Gross

    2004-10-25

    The primary purpose of this model report is to develop abstractions for the response of engineered barrier system (EBS) components to seismic hazards at a geologic repository at Yucca Mountain, Nevada, and to define the methodology for using these abstractions in a seismic scenario class for the Total System Performance Assessment - License Application (TSPA-LA). A secondary purpose of this model report is to provide information for criticality studies related to seismic hazards. The seismic hazards addressed herein are vibratory ground motion, fault displacement, and rockfall due to ground motion. The EBS components are the drip shield, the waste package, and the fuel cladding. The requirements for development of the abstractions and the associated algorithms for the seismic scenario class are defined in ''Technical Work Plan For: Regulatory Integration Modeling of Drift Degradation, Waste Package and Drip Shield Vibratory Motion and Seismic Consequences'' (BSC 2004 [DIRS 171520]). The development of these abstractions will provide a more complete representation of flow into and transport from the EBS under disruptive events. The results from this development will also address portions of integrated subissue ENG2, Mechanical Disruption of Engineered Barriers, including the acceptance criteria for this subissue defined in Section 2.2.1.3.2.3 of the ''Yucca Mountain Review Plan, Final Report'' (NRC 2003 [DIRS 163274]).

  20. Simplified design procedure for base isolation system

    Energy Technology Data Exchange (ETDEWEB)

    Takayama, Mineo; Tada, Hideyuki [Fukuoka Univ. (Japan). Faculty of Engineering

    1995-12-01

    This paper presents a simplified design procedure which incorporates an existing response prediction method for base isolated buildings into design methods for isolation devices (rubber bearings and hysteresis dampers). The procedure enables a designer to easily identify the relationship between tile seismic behavior of base-isolated buildings and the characteristics of isolation devices. The prediction method, proposed by Prof. Akiyama, is based on energy balance between the total input seismic energy and the energy absorbed by the isolation devices. The method is very accurate. The design methods for devices were developed by authors based on experimental and finite element analysis results.

  1. Seismicity in Northern Germany

    Science.gov (United States)

    Bischoff, Monika; Gestermann, Nicolai; Plenefisch, Thomas; Bönnemann, Christian

    2013-04-01

    Northern Germany is a region of low tectonic activity, where only few and low-magnitude earthquakes occur. The driving tectonic processes are not well-understood up to now. In addition, seismic events during the last decade concentrated at the borders of the natural gas fields. The source depths of these events are shallow and in the depth range of the gas reservoirs. Based on these observations a causal relationship between seismicity near gas fields and the gas production is likely. The strongest of these earthquake had a magnitude of 4.5 and occurred near Rotenburg in 2004. Also smaller seismic events were considerably felt by the public and stimulated the discussion on the underlying processes. The latest seismic event occurred near Langwedel on 22nd November 2012 and had a magnitude of 2.8. Understanding the causes of the seismicity in Northern Germany is crucial for a thorough evaluation. Therefore the Seismological Service of Lower Saxony (NED) was established at the State Office for Mining, Energy and Geology (LBEG) of Lower Saxony in January 2013. Its main task is the monitoring and evaluation of the seismicity in Lower Saxony and adjacent areas. Scientific and technical questions are addressed in close cooperation with the Seismological Central Observatory (SZO) at the Federal Institute for Geosciences and Natural Resources (BGR). The seismological situation of Northern Germany will be presented. Possible causes of seismicity are introduced. Rare seismic events at greater depths are distributed over the whole region and probably are purely tectonic whereas events in the vicinity of natural gas fields are probably related to gas production. Improving the detection threshold of seismic events in Northern Germany is necessary for providing a better statistical basis for further analyses answering these questions. As a first step the existing seismic network will be densified over the next few years. The first borehole station was installed near Rethem by BGR

  2. Smart hybrid rotary damper

    Science.gov (United States)

    Yang, C. S. Walter; DesRoches, Reginald

    2014-03-01

    This paper develops a smart hybrid rotary damper using a re-centering smart shape memory alloy (SMA) material as well as conventional energy-dissipating metallic plates that are easy to be replaced. The ends of the SMA and steel plates are inserted in the hinge. When the damper rotates, all the plates bend, providing energy dissipating and recentering characteristics. Such smart hybrid rotary dampers can be installed in structures to mitigate structural responses and to re-center automatically. The damaged energy-dissipating plates can be easily replaced promptly after an external excitation, reducing repair time and costs. An OpenSEES model of a smart hybrid rotary was established and calibrated to reproduce the realistic behavior measured from a full-scale experimental test. Furthermore, the seismic performance of a 3-story moment resisting model building with smart hybrid rotary dampers designed for downtown Los Angeles was also evaluated in the OpenSEES structural analysis software. Such a smart moment resisting frame exhibits perfect residual roof displacement, 0.006", extremely smaller than 18.04" for the conventional moment resisting frame subjected to a 2500 year return period ground motion for the downtown LA area (an amplified factor of 1.15 on Kobe earthquake). The smart hybrid rotary dampers are also applied into an eccentric braced steel frame, which combines a moment frame system and a bracing system. The results illustrate that adding smart hybrid rotaries in this braced system not only completely restores the building after an external excitation, but also significantly reduces peak interstory drifts.

  3. Seismic anisotropy: tracing plate dynamics in the mantle.

    Science.gov (United States)

    Park, Jeffrey; Levin, Vadim

    2002-04-19

    Elastic anisotropy is present where the speed of a seismic wave depends on its direction. In Earth's mantle, elastic anisotropy is induced by minerals that are preferentially oriented in a directional flow or deformation. Earthquakes generate two seismic wave types: compressional (P) and shear (S) waves, whose coupling in anisotropic rocks leads to scattering, birefringence, and waves with hybrid polarizations. This varied behavior is helping geophysicists explore rock textures within Earth's mantle and crust, map present-day upper-mantle convection, and study the formation of lithospheric plates and the accretion of continents in Earth history.

  4. Nucleotide divergence vs. gene expression differentiation: comparative transcriptome sequencing in natural isolates from the carrion crow and its hybrid zone with the hooded crow.

    Science.gov (United States)

    Wolf, Jochen B W; Bayer, Till; Haubold, Bernhard; Schilhabel, Markus; Rosenstiel, Philip; Tautz, Diethard

    2010-03-01

    Recent advances in sequencing technology promise to provide new strategies for studying population differentiation and speciation phenomena in their earliest phases. We focus here on the black carrion crow (Corvus [corone] corone), which forms a zone of hybridization and overlap with the grey coated hooded crow (Corvus [corone] cornix). However, although these semispecies are taxonomically distinct, previous analyses based on several types of genetic markers did not reveal significant molecular differentiation between them. We here corroborate this result with sequence data obtained from a set of 25 nuclear intronic loci. Thus, the system represents a case of a very early phase of species divergence that requires new molecular approaches for its description. We have therefore generated RNAseq expression profiles using barcoded massively parallel pyrosequencing of brain mRNA from six individuals of the carrion crow and five individuals from a hybrid zone with the hooded crow. We obtained 856 675 reads from two runs, with average read length of 270 nt and coverage of 8.44. Reads were assembled de novo into 19 552 contigs, 70% of which could be assigned to annotated genes in chicken and zebra finch. This resulted in a total of 7637 orthologous genes and a core set of 1301 genes that could be compared across all individuals. We find a clear clustering of expression profiles for the pure carrion crow animals and disperse profiles for the animals from the hybrid zone. These results suggest that gene expression differences may indeed be a sensitive indicator of initial species divergence.

  5. On the isolation of elemental carbon for micro-molar 14C accelerator mass spectrometry; evaluation of alternative isolation procedures, and accuracy assurance using a hybrid isotopic particulate carbon reference material

    OpenAIRE

    Currie, L A; Kessler,J.D.

    2005-01-01

    International audience; The primary objective of the research reported here has been the development of an hybrid reference material (RM) to serve as a test of accuracy for elemental carbon (EC) isotopic (14C) speciation measurements. Such measurements are critically important for the quantitative apportionment of fossil and biomass sources of ''soot'' (EC), the tracer of fire that has profound effects on health, atmospheric visibility, and climate. Previous studies of 14C-EC measurement qual...

  6. Landslide seismic magnitude

    Science.gov (United States)

    Lin, C. H.; Jan, J. C.; Pu, H. C.; Tu, Y.; Chen, C. C.; Wu, Y. M.

    2015-11-01

    Landslides have become one of the most deadly natural disasters on earth, not only due to a significant increase in extreme climate change caused by global warming, but also rapid economic development in topographic relief areas. How to detect landslides using a real-time system has become an important question for reducing possible landslide impacts on human society. However, traditional detection of landslides, either through direct surveys in the field or remote sensing images obtained via aircraft or satellites, is highly time consuming. Here we analyze very long period seismic signals (20-50 s) generated by large landslides such as Typhoon Morakot, which passed though Taiwan in August 2009. In addition to successfully locating 109 large landslides, we define landslide seismic magnitude based on an empirical formula: Lm = log ⁡ (A) + 0.55 log ⁡ (Δ) + 2.44, where A is the maximum displacement (μm) recorded at one seismic station and Δ is its distance (km) from the landslide. We conclude that both the location and seismic magnitude of large landslides can be rapidly estimated from broadband seismic networks for both academic and applied purposes, similar to earthquake monitoring. We suggest a real-time algorithm be set up for routine monitoring of landslides in places where they pose a frequent threat.

  7. Studies on seismic source

    Institute of Scientific and Technical Information of China (English)

    李世愚; 陈运泰

    2003-01-01

    During the period of 1999~2002, the Chinese seismologists made a serious of developments in the study on seismic sources including observations, experiments and theory. In the field of observation, the methods of the accuracy location of earthquake sources, the inversion of seismic moment tensor and the mechanism of earthquake source are improved and developed. A lot of important earthquake events are studied by using these methods. The rupture processes of these events are inverted and investigated combined with the local stress fields and the tectonic moment by using the measurements of surface deformation. In the fields of experiments and theory, many developments are obtained in cause of seismic formation, condition of stress and tectonics, dynamics of earthquake rupture, rock fracture and nucleation of strong earthquakes.

  8. Ants exhibit asymmetric hybridization in a mosaic hybrid zone.

    Science.gov (United States)

    Purcell, Jessica; Zahnd, Sacha; Athanasiades, Anouk; Türler, Rebecca; Chapuisat, Michel; Brelsford, Alan

    2016-10-01

    Research on hybridization between species provides unparalleled insights into the pre- and postzygotic isolating mechanisms that drive speciation. In social organisms, colony-level incompatibilities may provide additional reproductive barriers not present in solitary species, and hybrid zones offer an opportunity to identify these barriers. Here, we use genotyping-by-sequencing to sequence hundreds of markers in a hybrid zone between two socially polymorphic ant species, Formica selysi and Formica cinerea. We characterize the zone, determine the frequency of hybrid workers, infer whether hybrid queens or males are produced and investigate whether hybridization is influenced by colony social organization. We also compare cuticular hydrocarbon profiles and aggression levels between the two species. The hybrid zone exhibits a mosaic structure. The asymmetric distribution of hybrids skewed towards F. cinerea suggests a pattern of unidirectional nuclear gene flow from F. selysi into F. cinerea. The occurrence of backcrossed individuals indicates that hybrid queens and/or males are fertile, and the presence of the F. cinerea mitochondrial haplotype in 97% of hybrids shows that successful F1 hybrids will generally have F. cinerea mothers and F. selysi fathers. We found no evidence that social organization contributes to speciation, because hybrids occur in both single-queen and multiple-queen colonies. Strongly differentiated cuticular hydrocarbon profiles and heightened interspecific aggression further reveal that species recognition cues are both present and perceived. The discovery of fertile hybrids and asymmetrical gene flow is unusual in ants, and this hybrid zone will therefore provide an ideal system with which to investigate speciation in social insects.

  9. Seismic Disaster Reduction in China

    Institute of Scientific and Technical Information of China (English)

    Ministry of Construction

    2001-01-01

    @@ Great accomplishments have been made in seismic disaster reduction in China's engineering construction and city construction projects during the past decade (1990~2000). A new national map on the division of seismic intensity has been promulgated, and a series of anti-seismic standards and norms have been drafted or revised, which has further improved the country's technical code system on anti-seismic engineering measures.

  10. Tools for assessing kinship, population structure, phylogeography, and interspecific hybridization in Asian carps invasive to the Mississippi River, USA: isolation and characterization of novel tetranucleotide microsatellite DNA loci in silver carp Hypophthalmichthys molitrix

    Science.gov (United States)

    King, T.L.; Eackles, M.S.; Chapman, D.C.

    2011-01-01

    We document the isolation and characterization of novel tetranucleotide microsatellite DNA markers for the invasive silver carp Hypophthalmichthys molitrix and provide the results of cross-species amplification for three additional invasive carp species: bighead (H. nobilis), grass (Ctenopharyngodon idella) and black (Mylopharyngodon piceus). In the target species these markers yielded levels of allelic diversity (average 4.4 alleles/locus) and heterozygosity (average 54.7%) sufficient to: (1) provide unique multilocus genotypes; (2) delineate kinship relationships; (3) differentiate populations/species; (4) estimate effective population sizes; and (5) provide unique demographic perspectives for control or eradication. Currently these markers are being utilized to determine the degree of introgressive hybridization between H. molitrix and H. nobilis, to quantify gene flow between different sub-basins established in the central United States, and to assess the demographic status of sub-basin groups. This information will be critically important in the management/control of these invasive species.

  11. B341 Seismic Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Halle, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-01-02

    The Seismic Evaluation of Building 341 located at Lawrence Livermore National Laboratory in Livermore, California has been completed. The subject building consists of a main building, Increment 1, and two smaller additions; Increments 2 and 3. Based on our evaluation the building does not meet a Life Safety performance level for the BSE- 1E earthquake ground shaking hazard. The BSE-1E is the recommended seismic hazard level for evaluation of existing structures and is based on a 20% probability of exceedence in 50 years.

  12. Induced Seismicity Monitoring System

    Science.gov (United States)

    Taylor, S. R.; Jarpe, S.; Harben, P.

    2014-12-01

    There are many seismological aspects associated with monitoring of permanent storage of carbon dioxide (CO2) in geologic formations. Many of these include monitoring underground gas migration through detailed tomographic studies of rock properties, integrity of the cap rock and micro seismicity with time. These types of studies require expensive deployments of surface and borehole sensors in the vicinity of the CO2 injection wells. Another problem that may exist in CO2 sequestration fields is the potential for damaging induced seismicity associated with fluid injection into the geologic reservoir. Seismic hazard monitoring in CO2 sequestration fields requires a seismic network over a spatially larger region possibly having stations in remote settings. Expensive observatory-grade seismic systems are not necessary for seismic hazard deployments or small-scale tomographic studies. Hazard monitoring requires accurate location of induced seismicity to magnitude levels only slightly less than that which can be felt at the surface (e.g. magnitude 1), and the frequencies of interest for tomographic analysis are ~1 Hz and greater. We have developed a seismo/acoustic smart sensor system that can achieve the goals necessary for induced seismicity monitoring in CO2 sequestration fields. The unit is inexpensive, lightweight, easy to deploy, can operate remotely under harsh conditions and features 9 channels of recording (currently 3C 4.5 Hz geophone, MEMS accelerometer and microphone). An on-board processor allows for satellite transmission of parameter data to a processing center. Continuous or event-detected data is kept on two removable flash SD cards of up to 64+ Gbytes each. If available, data can be transmitted via cell phone modem or picked up via site visits. Low-power consumption allows for autonomous operation using only a 10 watt solar panel and a gel-cell battery. The system has been successfully tested for long-term (> 6 months) remote operations over a wide range

  13. Characterization of the Virgo Seismic Environment

    CERN Document Server

    Accadia, T; Astone, P; Ballardin, G; Barone, F; Barsuglia, M; Basti, A; Bauer, Th S; Bebronne, M; Beker, M G; Belletoile, A; Bitossi, M; Bizouard, M A; Blom, M; Bondu, F; Bonelli, L; Bonnand, R; Boschi, V; Bosi, L; Bouhou, B; Braccini, S; Bradaschia, C; Branchesi, M; Briant, T; Brillet, A; Brisson, V; Bulik, T; Bulten, H J; Buskulic, D; Buy, C; Cagnoli, G; Calloni, E; Canuel, B; Carbognani, F; Cavalier, F; Cavalieri, R; Cella, G; Cesarini, E; Chaibi, O; Chassande-Mottin, E; Chincarini, A; Chiummo, A; Cleva, F; Coccia, E; Cohadon, P -F; Colacino, C N; Colas, J; Colla, A; Colombini, M; Conte, A; Coughlin, M; Coulon, J -P; Cuoco, E; DAntonio, S; Dattilo, V; Davier, M; Day, R; De Rosa, R; Debreczeni, G; Del Pozzo, W; del Prete, M; Di Fiore, L; Di Lieto, A; Emilio, M Di Paolo; Di Virgilio, A; Dietz, A; Drago, M; Endroczi, G; Fafone, V; Ferrante, I; Fidecaro, F; Fiori, I; Flaminio, R; Forte, L A; Fournier, J -D; Franc, J; Frasca, S; Frasconi, F; Galimberti, M; Gammaitoni, L; Garufi, F; Gaspar, M E; Gemme, G; Genin, E; Gennai, A; Giazotto, A; Gouaty, R; Granata, M; Greverie, C; Guidi, G M; Hayau, J -F; Heidmann, A; Heitmann, H; Hello, P; Jaranowski, P; Kowalska, I; Krolak, A; Leroy, N; Letendre, N; Li, T G F; Liguori, N; Lorenzini, M; Loriette, V; Losurdo, G; Majorana, E; Maksimovic, I; Man, N; Mantovani, M; Marchesoni, F; Marion, F; Marque, J; Martelli, F; Masserot, A; Michel, C; Milano, L; Minenkov, Y; Mohan, M; Morgado, N; Morgia, A; Mosca, S; Mours, B; Naticchioni, L; Nocera, F; Pagliaroli, G; Palladino, L; Palomba, C; Paoletti, F; Parisi, M; Pasqualetti, A; Passaquieti, R; Passuello, D; Persichetti, G; Piergiovanni, F; Pietka, M; Pinard, L; Poggiani, R; Prato, M; Prodi, G A; Punturo, M; Puppo, P; Rabeling, D S; Racz, I; Rapagnani, P; Re, V; Regimbau, T; Ricci, F; Robinet, F; Rocchi, A; Rolland, L; Romano, R; Rosinska, D; Ruggi, P; Sassolas, B; Sentenac, D; Sperandio, L; Sturani, R; Swinkels, B; Tacca, M; Taffarello, L; Toncelli, A; Tonelli, M; Torre, O; Tournefier, E; Travasso, F; Vajente, G; Brand, J F J van den; Broeck, C Van Den; van der Putten, S; Vasuth, M; Vavoulidis, M; Vedovato, G; Verkindt, D; Vetrano, F; Vicere, A; Vinet, J -Y; Vitale, S; Vocca, H; Ward, R L; Was, M; Yvert, M; Zadrozny, A; Zendri, J -P

    2011-01-01

    The Virgo gravitational wave detector is an interferometer (ITF) with 3km arms located in Pisa, Italy. From July to October 2010, Virgo performed its third science run (VSR3) in coincidence with the LIGO detectors. Despite several techniques adopted to isolate the interferometer from the environment, seismic noise remains an important issue for Virgo. Vibrations produced by the detector infrastructure (such as air conditioning units, water chillers/heaters, pumps) are found to affect Virgo's sensitivity, with the main coupling mechanisms being through beam jitter and scattered light processes. The Advanced Virgo (AdV) design seeks to reduce ITF couplings to environmental noise by having most vibration-sensitive components suspended and in-vacuum, as well as muffle and relocate loud machines. During the months of June and July 2010, a Guralp-3TD seismometer was stationed at various locations around the Virgo site hosting major infrastructure machines. Seismic data were examined using spectral and coherence ana...

  14. “Tropicalisation” of Feed-in Tariffs: a custom-made support scheme for hybrid PV/diesel systems in isolated regions

    NARCIS (Netherlands)

    Solano-Peralta, M.; Moner-Girona, M.; van Sark, W.G.J.H.M.; Vallvè, X.

    2009-01-01

    The interest and actions towards introducing renewables for off-grid regions has increased due to their ostensible cost-effectiveness, eco-friendliness and quality services provided. Nevertheless, in many isolated areas diesel generators appear as a common option, confirming that there is a need for

  15. SEISMIC RESPONSE OF FRAME BUILDINGS WITH COMBINED EARTHQUAKE PROTECTION SYSTEM

    Directory of Open Access Journals (Sweden)

    Abakar J. Abakarov

    2017-01-01

    Full Text Available Abstract. Objectives The aim of the study is to search for methods to improve the efficiency of the earthquake protection systems with rubber-metallic seismic insulating supports by combining them with dry friction and brittle uncoupling elements. Method The research is based on dynamic modelling methods. Results The computational dynamic model of the combined earthquake protection system and the system of differential equations of the seismic motion of a five-story frame building were compiled and an algorithm for estimating the efficiency and selection of the optimum parameters of the earthquake protection system was developed. Horizontal shifting seismic forces, maximum mass movements and maximum movements of rubber-metallic seismic insulating supports at different intensities and prevailing periods of seismic soil oscillations were determined. It is shown that, by using a combined earthquake protection system, seismic loads on frame buildings can be reduced by a factor of 1.5-2 and maximum mass movements – by 4-5 times. In addition, the area of rational application of seismic isolation systems with rubber-metallic supports in relation to the prevailing periods of seismic ground oscillations is expanding substantially. Conclusion The combined earthquake protection system allows the area of effective use of rubber-metallic supports to be expanded by increasing the range of possible prevailing periods of seismic soil vibrations at which the maximum movement of the top of the rubber-metallic supports does not exceed the maximum allowable value. The maximum residual movements of rubber-metallic supports can be reduced by using a lead core. 

  16. Hybrid vehicles

    Energy Technology Data Exchange (ETDEWEB)

    West, J.G.W. [Electrical Machines (United Kingdom)

    1997-07-01

    The reasons for adopting hybrid vehicles result mainly from the lack of adequate range from electric vehicles at an acceptable cost. Hybrids can offer significant improvements in emissions and fuel economy. Series and parallel hybrids are compared. A combination of series and parallel operation would be the ideal. This can be obtained using a planetary gearbox as a power split device allowing a small generator to transfer power to the propulsion motor giving the effect of a CVT. It allows the engine to run at semi-constant speed giving better fuel economy and reduced emissions. Hybrid car developments are described that show the wide range of possible hybrid systems. (author)

  17. Stochastic seismic inversion using greedy annealed importance sampling

    Science.gov (United States)

    Xue, Yang; Sen, Mrinal K.

    2016-10-01

    A global optimization method called very fast simulated annealing (VFSA) inversion has been applied to seismic inversion. Here we address some of the limitations of VFSA by developing a new stochastic inference method, named greedy annealed importance sampling (GAIS). GAIS combines VFSA and greedy importance sampling (GIS), which uses a greedy search in the important regions located by VFSA, in order to attain fast convergence and provide unbiased estimation. We demonstrate the performance of GAIS with application to seismic inversion of field post- and pre-stack datasets. The results indicate that GAIS can improve lateral continuity of the inverted impedance profiles and provide better estimation of uncertainties than using VFSA alone. Thus this new hybrid method combining global and local optimization methods can be applied in seismic reservoir characterization and reservoir monitoring for accurate estimation of reservoir models and their uncertainties.

  18. Nonstructural seismic restraint guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Butler, D.M.; Czapinski, R.H.; Firneno, M.J.; Feemster, H.C.; Fornaciari, N.R.; Hillaire, R.G.; Kinzel, R.L.; Kirk, D.; McMahon, T.T.

    1993-08-01

    The Nonstructural Seismic Restraint Guidelines provide general information about how to secure or restrain items (such as material, equipment, furniture, and tools) in order to prevent injury and property, environmental, or programmatic damage during or following an earthquake. All SNL sites may experience earthquakes of magnitude 6.0 or higher on the Richter scale. Therefore, these guidelines are written for all SNL sites.

  19. Understanding induced seismicity

    NARCIS (Netherlands)

    Elsworth, Derek; Spiers, Christopher J.; Niemeijer, Andre R.

    2016-01-01

    Fluid injection–induced seismicity has become increasingly widespread in oil- and gas-producing areas of the United States (1–3) and western Canada. It has shelved deep geothermal energy projects in Switzerland and the United States (4), and its effects are especially acute in Oklahoma, where seismi

  20. Understanding induced seismicity

    NARCIS (Netherlands)

    Elsworth, Derek; Spiers, Christopher J.; Niemeijer, Andre R.

    2016-01-01

    Fluid injection–induced seismicity has become increasingly widespread in oil- and gas-producing areas of the United States (1–3) and western Canada. It has shelved deep geothermal energy projects in Switzerland and the United States (4), and its effects are especially acute in Oklahoma, where

  1. Geophysics and Seismic Hazard Reduction

    Institute of Scientific and Technical Information of China (English)

    YuGuihua; ZhouYuanze; YuSheng

    2003-01-01

    The earthquake is a natural phenomenon, which often brings serious hazard to the human life and material possession. It is a physical process of releasing interior energy of the earth, which is caused by interior and outer forces in special tectonic environment in the earth, especially within the lithosphere. The earthquake only causes casualty and loss in the place where people inhabit. Seismic hazard reduction is composed of four parts as seismic prediction, hazard prevention and seismic engineering, seismic response and seismic rescuing, and rebuilding.

  2. Characterization of cellulose I/II hybrid fibers isolated from energycane bagasse during the delignification process: Morphology, crystallinity and percentage estimation.

    Science.gov (United States)

    Yue, Yiying; Han, Jingquan; Han, Guangping; Zhang, Quanguo; French, Alfred D; Wu, Qinglin

    2015-11-20

    Cellulose I, cellulose II and cellulose I/II hybrid fibers were prepared from energycane bagasse using NaOH and NaClO2 treatments. The definitive defibrillation effect with an average width of 12±5μm was observed for the fibers treated with 20wt% NaOH for 10h and NaClO2 for 2h. The ribbon shaped cellulose I fibers were converted to a swollen state with a rougher surface by 20wt% NaOH treatment for 10h. The percentage of cellulose I decreased from 100% to 5%, and the corresponding CI values increased from 58.2% to 68.8% during the conversion from cellulose I to II. After further NaClO2 treatment, the CI values were decreased because of partial destruction of hydrogen bond network. XRD, NMR and FTIR results present the same trend in the degree of crystallization for all the samples.

  3. High Voltage Seismic Generator

    Science.gov (United States)

    Bogacz, Adrian; Pala, Damian; Knafel, Marcin

    2015-04-01

    This contribution describes the preliminary result of annual cooperation of three student research groups from AGH UST in Krakow, Poland. The aim of this cooperation was to develop and construct a high voltage seismic wave generator. Constructed device uses a high-energy electrical discharge to generate seismic wave in ground. This type of device can be applied in several different methods of seismic measurement, but because of its limited power it is mainly dedicated for engineering geophysics. The source operates on a basic physical principles. The energy is stored in capacitor bank, which is charged by two stage low to high voltage converter. Stored energy is then released in very short time through high voltage thyristor in spark gap. The whole appliance is powered from li-ion battery and controlled by ATmega microcontroller. It is possible to construct larger and more powerful device. In this contribution the structure of device with technical specifications is resented. As a part of the investigation the prototype was built and series of experiments conducted. System parameter was measured, on this basis specification of elements for the final device were chosen. First stage of the project was successful. It was possible to efficiently generate seismic waves with constructed device. Then the field test was conducted. Spark gap wasplaced in shallowborehole(0.5 m) filled with salt water. Geophones were placed on the ground in straight line. The comparison of signal registered with hammer source and sparker source was made. The results of the test measurements are presented and discussed. Analysis of the collected data shows that characteristic of generated seismic signal is very promising, thus confirms possibility of practical application of the new high voltage generator. The biggest advantage of presented device after signal characteristics is its size which is 0.5 x 0.25 x 0.2 m and weight approximately 7 kg. This features with small li-ion battery makes

  4. Optimal design of a hybrid photovoltaic and fuel cell power generation system, to supply isolated communities in the Brazilian Amazon; Dimensionamento otimo de sistemas hibridos, com geracao fotovoltaica e celula a combustivel, para atendimento a comunidades isoladas na Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Sergio Batista da

    2010-11-15

    The lack of electricity in isolated communities in the Brazilian Amazon has become one of the greatest barrier for the development of the region. Currently, the main technologies that provide electricity to these communities are diesel generators, batteries and dry cells. These non-renewable energy sources may pose serious problems to the environment and human health and have high maintenance and operational costs. Therefore, the search for renewable energy sources, such as water and sunlight, which are highly abundant in the region, has become a great challenge. This thesis presents the studies on application of solar photovoltaic (PV) and fuel cell (FC) technologies to supply electric power in an uninterrupted manner. Outlined are the technical and cost issues of a pilot project set up in an environmentally protected area, next to Bananal island, located in the Southwestern region of the state of Tocantins. The pilot project relies on PV solar power as the primary source of energy for the production of electricity. The surplus energy is stored in the form of hydrogen produced by electrolysis of the water supplied locally, which is reconverted into electric power by fuel cells during periods when there is little or no sunlight. In this context, the aim of the study was to propose a sizing of a hybrid distributed generation system (HDGS), comprised of a PV system, FC and batteries, that optimizes implementation and operational costs, as a potential source of energy for isolated communities in the Amazon. The work was carried out with the help of simulation software HOMER (Hybrid Optimization Model for Electric Renewable) developed by National Renewable Energy Laboratory (NREL). Simulations and a comparative study were carried out of the technologies and potential configurations that meet the needs of these isolated communities. The results showed an optimal solution of HGDS PV-FC batteries with a reduction in the initial cost of the project in about 60% compared to

  5. Isolation of Edwardsiella tarda from cultured hybrid snakehead (Channa maculata♀× C. argus♂)and its identification%养殖杂交鳢迟缓爱德华菌的分离鉴定

    Institute of Scientific and Technical Information of China (English)

    陈言峰; 周爱国; 陈冠锋; 陈建酬; 张继平; 张辉华

    2014-01-01

    Two pathogenic bacteria( ZS201364-1,ZS201364-2)isolated from diseased hybrid snakeheads( Channa maculata♀× C. argus♂)were identified to be Edwardsiella tarda by analyses of biochemical features and 16S rDNA sequence. The anaerobic,gram negative,bacilliform and motile isolates utilized glucoses and maltose as energy. Both indole and M. R. tests proved positive. The LD50 s of the isolates to healthy hybrid snakeheads were 7. 1 × 105 cfu·g-1 and 5. 6 × 105 cfu·g-1 ,respectively. The optimal growth con-ditions of strain ZS201364-1,which was highly susceptible to cefotaxime,ciprofloxacin and norfloxacin,were 25~35 ℃ pH 7 ~8 and 1% NaCl.%从患病杂交鳢[斑鳢( Channa maculata )♀×乌鳢( C. argus )♂]体内分离到2株致病菌( ZS201364-1和ZS201364-2),通过对其生化特性与16S rRNA基因序列进行分析,确定为迟缓爱德华菌( Edwardsiella tarda)。该致病菌兼性厌氧,为革兰氏阴性短杆菌,能运动,能发酵葡萄糖、麦芽糖。吲哚试验和MR试验均为阳性。2株致病菌对杂交鳢的半致死剂量( LD50)分别为7.1×105 cfu·g-1和5.6×105 cfu·g-1。ZS201364-1最适生长温度为25~35℃、pH为7~8、氯化钠( NaCl)质量分数为1%,对头孢噻肟、环丙沙星、诺氟沙星等抗生素高度敏感。

  6. Dynamic Bayesian filtering for real-time seismic analyses

    Energy Technology Data Exchange (ETDEWEB)

    Blough, D.K.; Rohay, A.C.; Anderson, K.K.; Nicholson, W.L.

    1994-04-01

    State space modeling, which includes techniques such as the Kalman filter, has been used to analyze many non-stationary time series. The ability of these dynamic models to adapt and track changes in the underlying process makes them attractive for application to the real-time analysis of three-component seismic waveforms. The authors are investigating the application of state space models formulated as Bayesian time series models to phase detection, polarization, and spectrogram estimation of seismograms. This approach removes the need to specify data windows in the time series for time averaging estimation (e.g., spectrum estimation). They are using this model to isolate particular seismic phases based on polarization parameters that are determined at a spectrum of frequencies. They plan to use polarization parameters, frequency spectra, and magnitudes to discriminate between different types of seismic sources. They present the application of this technique to artificial time series and to several real seismic events including the Non-Proliferation Experiment (NPE) two nuclear tests and three earthquakes from the Nevada Test site, as recorded on several regional broadband seismic stations. A preliminary result of this analysis indicates that earthquakes and explosions can potentially be discriminated on the bass of the polarization characteristics of scattered seismic phases. However, the chemical (NPE) and nuclear explosions appear to have very similar polarization characteristics.

  7. SEISMIC RESPONSE ANALYSIS OF RC-SPHERICAL STEEL FRAME HYBRID STRUCTURE%钢筋混凝土-球形钢框架混合结构地震反应分析

    Institute of Scientific and Technical Information of China (English)

    薛建阳; 韩琛; 陈卓

    2015-01-01

    A series of analysis of a hybrid structure exhibition hall were conducted by FEM software MIDAS/Gen, including spectrum analysis, elastic time-history analysis and Pushover analysis.Comparing the results of elastic time-history analysis with those of spectrum analysis, the weaker stiffness parts of the structure were found, which provided a reference for the aseismic design of a complex structure.Based on capacity spectrum method through MIDAS/Gen, the requirement spectrum, capacity spectrum and performance point of the structure were obtained while elastic-plastic responses of the structure under severe earthquake were also analyzed.The research findings indicated that the structural vibration was dominated by translation motion, meanwhile, the phenomenon that the plastic hinge appeared at the beam end firstly before the top of the structure reached the target displacement complied with the beam plastic-hinge failure mechanism.%运用有限元软件MIDAS/Gen,对一混合结构展厅进行振型分解反应谱分析、弹性时程分析以及静力弹塑性分析. 将时程分析与反应谱分析的结果进行对比,找出该结构的薄弱层,为复杂结构的抗震设计提供参考. 根据MIDAS/Gen提供的能力谱法,得到该结构的能力谱和需求谱及结构的性能点,并分析罕遇地震下结构的弹塑性反应. 研究结果表明:该结构振动以平动为主,在顶点达到目标位移之前,梁端首先出现塑性铰,符合梁铰破坏机制.

  8. Comparison of seismic sources for shallow seismic: sledgehammer and pyrotechnics

    Directory of Open Access Journals (Sweden)

    Brom Aleksander

    2015-10-01

    Full Text Available The pyrotechnic materials are one of the types of the explosives materials which produce thermal, luminous or sound effects, gas, smoke and their combination as a result of a self-sustaining chemical reaction. Therefore, pyrotechnics can be used as a seismic source that is designed to release accumulated energy in a form of seismic wave recorded by tremor sensors (geophones after its passage through the rock mass. The aim of this paper was to determine the utility of pyrotechnics for shallow seismic engineering. The work presented comparing the conventional method of seismic wave excitation for seismic refraction method like plate and hammer and activating of firecrackers on the surface. The energy released by various sources and frequency spectra was compared for the two types of sources. The obtained results did not determine which sources gave the better results but showed very interesting aspects of using pyrotechnics in seismic measurements for example the use of pyrotechnic materials in MASW.

  9. Isolation of biosynthesis related transcripts of 2,3,5,4'-tetrahydroxy stilbene-2-O-β-D-glucoside from Fallopia multiflora by suppression subtractive hybridization

    Directory of Open Access Journals (Sweden)

    Wei Zhao

    2014-07-01

    Full Text Available 2,3,5,4'-tetrahydroxy stilbene-2-O-ß-D-glucoside (THSG exerts multiple pharmacodynamic actions, found in Fallopia multiflora, but the biosynthesis pathway of THSG is still unclear. To clear this ambiguity, we constructed suppression subtractive hybridization (SSH libraries to screen the genes involved in THSG biosynthesis from two F. multiflora varieties, which vary significantly in THSG content. Twelve non-redundant differentially expressed sequence tags were obtained and the full lengths of 4 unreported fragments were amplified by rapid amplification of cDNA ends. We totally got 7 full-length transcripts, and all of them were aligned to the transcriptome and digital gene expression tag profiling database of four F. multiflora tissues (root, stem and leaf from Deqing F. multiflora and another root from Chongqing F. multiflora; data unpublished using local BLAST. The results showed that there was a significant, organ specific difference in the expression of fragments and full-length sequences. All the sequences were annotated by aligning to nucleotide and protein databases. Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that THSG biosynthesis was correlated with multiple life activities.

  10. Isolation and characterization of genes functionally involved in ovarian development of the giant tiger shrimp Penaeus monodon by suppression subtractive hybridization (SSH).

    Science.gov (United States)

    Preechaphol, Rachanimuk; Klinbunga, Sirawut; Khamnamtong, Bavornlak; Menasveta, Piamsak

    2010-10-01

    Suppression subtractive hybridization (SSH) libraries between cDNA in stages I (previtellogenic) and III (cortical rod) ovaries of the giant tiger shrimp (Penaeus monodon) were established. In all, 452 ESTs were unidirectionally sequenced. Sequence assembly generated 28 contigs and 201 singletons, 109 of which (48.0%) corresponding to known sequences previously deposited in GenBank. Several reproduction-related transcripts were identified. The full-length cDNA of anaphase promoting complex subunit 11 (PmAPC11; 600 bp with an ORF of 255 bp corresponding to a polypeptide of 84 amino acids) and selenoprotein Mprecursor (PmSePM; 904 bp with an ORF of 396 bp corresponding to a polypeptide of 131 amino acids) were characterized and reported for the first time in penaeid shrimp. Semiquantitative RT-PCR revealed that the expression levels of PmSePM and keratinocyte-associated protein 2 significantly diminished throughout ovarian development, whereas Ser/Thrcheckpoint kinase 1 (Chk1), DNA replication licensing factor mcm2 and egalitarian were down-regulated in mature ovaries of wild P. monodon (p < 0.05). Accordingly, the expression profiles of PmSePM and keratinocyte-associated protein 2 could be used as biomarkers for evaluating the degree of reproductive maturation in domesticated P. monodon.

  11. Isolation and analysis of differentially expressed genes during asexual sporulation in liquid static culture of Ganoderma lucidum by suppression subtractive hybridization.

    Science.gov (United States)

    Xu, Jun-Wei; Zhao, Wei; Xu, Yi-Ning; Zhong, Jian-Jiang

    2012-04-01

    Ganoderma lucidum differentiates in liquid static culture by forming aerial mycelia and asexual spores, and this differentiation process is accompanied by higher production of anti-tumor compounds ganoderic acids. To gain an insight into the molecular events during asexual sporulation of G. lucidum, comparative transcriptome analysis using suppression subtractive hybridization (SSH) technique was performed to identify preferentially expressed genes in liquid static culture vs. in traditional shaking culture. After macroarray analysis of 1920 cDNAs from SSH library, 147 unigenes which exhibited high expression in static culture were identified. Among these sequences, putative translations of 88 unigenes possessed much similarity to known proteins involved in cell organization, signal transduction, cell metabolism, protein biosynthesis and transcription regulation; 13 had significant similarity to hypothetical proteins; the remaining 46 showed little or no similarity to GenBank sequences. RT-qPCR analysis confirmed increases in transcripts of selected genes under liquid static culture condition. The results of this study present the useful application of EST analysis on G. lucidum and provide preliminary indication of gene expression putatively involved in asexual sporulation process.

  12. Isolation and characterization of genes functionally involved in ovarian development of the giant tiger shrimp Penaeus monodon by suppression subtractive hybridization (SSH

    Directory of Open Access Journals (Sweden)

    Rachanimuk Preechaphol

    2010-01-01

    Full Text Available Suppression subtractive hybridization (SSH libraries between cDNA in stages I (previtellogenic and III (cortical rod ovaries of the giant tiger shrimp (Penaeus monodon were established. In all, 452 ESTs were unidirectionally sequenced. Sequence assembly generated 28 contigs and 201 singletons, 109 of which (48.0% corresponding to known sequences previously deposited in GenBank. Several reproduction-related transcripts were identified. The full-length cDNA of anaphase promoting complex subunit 11 (PmAPC11; 600 bp with an ORF of 255 bp corresponding to a polypeptide of 84 amino acids and selenoprotein M precursor (PmSePM; 904 bp with an ORF of 396 bp corresponding to a polypeptide of 131 amino acids were characterized and reported for the first time in penaeid shrimp. Semiquantitative RT-PCR revealed that the expression levels of PmSePM and keratinocyte-associated protein 2 significantly diminished throughout ovarian development, whereas Ser/Thr checkpoint kinase 1 (Chk1, DNA replication licensing factor mcm2 and egalitarian were down-regulated in mature ovaries of wild P. monodon (p < 0.05. Accordingly, the expression profiles of PmSePM and keratinocyte-associated protein 2 could be used as biomarkers for evaluating the degree of reproductive maturation in domesticated P. monodon.

  13. Molecular characterization, expression patterns, and polymorphism of a differentially expressed porcine gene (PYGM) isolated by suppression subtractive hybridization and two-dimensional gel electrophoresis analysis.

    Science.gov (United States)

    Xu, Yongjie; Yu, Wenmin; Feng, Xiaoting; Xie, Hongtao; Xiong, Yuanzhu

    2012-01-01

    Suppression subtractive hybridization was performed to detect the differences in gene expression of porcine longissimus dorsi muscles between Large White and Chinese Meishan pigs. An upregulated gene in Large White that shared high homology with human muscle glycogen phosphorylase (PYGM) was identified. The porcine PYGM gene contains an open reading frame encoding 842 amino acid residues with 26 and 283 nucleotides in the 5' and 3' untranslated regions, respectively. Tissue distribution analysis indicated that porcine PYGM mRNAs are highly expressed in all tissues. Expression pattern of PYGM was similar in the two breeds. Both breeds had the highest expression levels when 120 days old (p<0.01), and PYGM was upregulated during skeletal muscle development. A similar expression pattern of PYGM in protein level was also observed by differential proteome analysis of skeletal muscle development using two-dimensional gel electrophoresis and mass spectroscopy. The mRNA abundance of PYGM in Large White was higher than Meishan at all four stages (p<0.05). Moreover, a G/T mutation in exon 8 was identified and association analysis with meat quality traits showed that it was significantly associated with lean meat percentage (p<0.05). Our data may provide further insight into the molecular mechanisms responsible for breed-specific differences in porcine growth and meat quality.

  14. Fuzzy-PI-based centralised control of semi-isolated FP-SEPIC/ZETA BDC in a PV/battery hybrid system

    Science.gov (United States)

    Mahendran, Venmathi; Ramabadran, Ramaprabha

    2016-11-01

    Multiport converters with centralised controller have been most commonly used in stand-alone photovoltaic (PV)/battery hybrid system to supply the load smoothly without any disturbances. This study presents the performance analysis of four-port SEPIC/ZETA bidirectional converter (FP-SEPIC/ZETA BDC) using various types of centralised control schemes like Fuzzy tuned proportional integral controller (Fuzzy-PI), fuzzy logic controller (FLC) and conventional proportional integral (PI) controller. The proposed FP-SEPIC/ZETA BDC with various control strategy is derived for simultaneous power management of a PV source using distributed maximum power point tracking (DMPPT) algorithm, a rechargeable battery, and a load by means of centralised controller. The steady state and the dynamic response of the FP-SEPIC/ZETA BDC are analysed using three different types of controllers under line and load regulation. The Fuzzy-PI-based control scheme improves the dynamic response of the system when compared with the FLC and the conventional PI controller. The power balance between the ports is achieved by pseudorandom carrier modulation scheme. The response of the FP-SEPIC/ZETA BDC is also validated experimentally using hardware prototype model of 500 W system. The effectiveness of the control strategy is validated using simulation and experimental results.

  15. Stutter seismic source

    Energy Technology Data Exchange (ETDEWEB)

    Gumma, W. H.; Hughes, D. R.; Zimmerman, N. S.

    1980-08-12

    An improved seismic prospecting system comprising the use of a closely spaced sequence of source initiations at essentially the same location to provide shorter objective-level wavelets than are obtainable with a single pulse. In a preferred form, three dynamite charges are detonated in the same or three closely spaced shot holes to generate a downward traveling wavelet having increased high frequency content and reduced content at a peak frequency determined by initial testing.

  16. Principle and Program of Evaluating Diffuse Seismicity

    Institute of Scientific and Technical Information of China (English)

    Chang Xiangdong

    2001-01-01

    Concept and origin of the term "the diffuse seismicity" are illustrated. Some different viewpoints regarding the diffuse seismicity and the influence characteristics on determining seismic design basis of engineering from the seismicity are analyzed. Principle and program for evaluating diffuse seismicity are studied and discussed base on over contents.

  17. Establishing seismic design criteria to achieve an acceptable seismic margin

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, R.P. [RPK Structural Mechanics Consulting, Inc., Yorba Linda, CA (United States)

    1997-01-01

    In order to develop a risk based seismic design criteria the following four issues must be addressed: (1) What target annual probability of seismic induced unacceptable performance is acceptable? (2). What minimum seismic margin is acceptable? (3) Given the decisions made under Issues 1 and 2, at what annual frequency of exceedance should the Safe Shutdown Earthquake ground motion be defined? (4) What seismic design criteria should be established to reasonably achieve the seismic margin defined under Issue 2? The first issue is purely a policy decision and is not addressed in this paper. Each of the other three issues are addressed. Issues 2 and 3 are integrally tied together so that a very large number of possible combinations of responses to these two issues can be used to achieve the target goal defined under Issue 1. Section 2 lays out a combined approach to these two issues and presents three potentially attractive combined resolutions of these two issues which reasonably achieves the target goal. The remainder of the paper discusses an approach which can be used to develop seismic design criteria aimed at achieving the desired seismic margin defined in resolution of Issue 2. Suggestions for revising existing seismic design criteria to more consistently achieve the desired seismic margin are presented.

  18. Seismic basement in Poland

    Science.gov (United States)

    Grad, Marek; Polkowski, Marcin

    2016-06-01

    The area of contact between Precambrian and Phanerozoic Europe in Poland has complicated structure of sedimentary cover and basement. The thinnest sedimentary cover in the Mazury-Belarus anteclize is only 0.3-1 km thick, increases to 7-8 km along the East European Craton margin, and 9-12 km in the Trans-European Suture Zone (TESZ). The Variscan domain is characterized by a 1- to 2-km-thick sedimentary cover, while the Carpathians are characterized by very thick sediments, up to c. 20 km. The map of the basement depth is created by combining data from geological boreholes with a set of regional seismic refraction profiles. These maps do not provide data about the basement depth in the central part of the TESZ and in the Carpathians. Therefore, the data set is supplemented by 32 models from deep seismic sounding profiles and a map of a high-resistivity (low-conductivity) layer from magnetotelluric soundings, identified as a basement. All of these data provide knowledge about the basement depth and of P-wave seismic velocities of the crystalline and consolidated type of basement for the whole area of Poland. Finally, the differentiation of the basement depth and velocity is discussed with respect to geophysical fields and the tectonic division of the area.

  19. Comparison of seismic actions and structural design requirements in Chinese Code GB 50011 and International Standard ISO 3010

    Institute of Scientific and Technical Information of China (English)

    王亚勇

    2004-01-01

    This paper presents a comparison between the Chinese Code GB50011-2001 and the International Standard ISO3010: 2001(E), emphasizing the similarities and differences related to design requirements, seismic actions and analytical approaches. Similarities include: earthquake return period, conceptual design, site classification, structural strength and ductility requirements, deformation limits, response spectra, seismic analysis procedures, isolation and energy dissipation,and nonstructural elements. Differences exist in the following areas: seismic levels, earthquake loading, mode damping factors and structural control.

  20. Seismic hazard assessment of Iran

    Directory of Open Access Journals (Sweden)

    M. Ghafory-Ashtiany

    1999-06-01

    Full Text Available The development of the new seismic hazard map of Iran is based on probabilistic seismic hazard computation using the historical earthquakes data, geology, tectonics, fault activity and seismic source models in Iran. These maps have been prepared to indicate the earthquake hazard of Iran in the form of iso-acceleration contour lines, and seismic hazard zoning, by using current probabilistic procedures. They display the probabilistic estimates of Peak Ground Acceleration (PGA for the return periods of 75 and 475 years. The maps have been divided into intervals of 0.25 degrees in both latitudinal and longitudinal directions to calculate the peak ground acceleration values at each grid point and draw the seismic hazard curves. The results presented in this study will provide the basis for the preparation of seismic risk maps, the estimation of earthquake insurance premiums, and the preliminary site evaluation of critical facilities.

  1. Seismic Imager Space Telescope

    Science.gov (United States)

    Sidick, Erkin; Coste, Keith; Cunningham, J.; Sievers,Michael W.; Agnes, Gregory S.; Polanco, Otto R.; Green, Joseph J.; Cameron, Bruce A.; Redding, David C.; Avouac, Jean Philippe; Ampuero, Jean Paul; Leprince, Sebastien; Michel, Remi

    2012-01-01

    A concept has been developed for a geostationary seismic imager (GSI), a space telescope in geostationary orbit above the Pacific coast of the Americas that would provide movies of many large earthquakes occurring in the area from Southern Chile to Southern Alaska. The GSI movies would cover a field of view as long as 300 km, at a spatial resolution of 3 to 15 m and a temporal resolution of 1 to 2 Hz, which is sufficient for accurate measurement of surface displacements and photometric changes induced by seismic waves. Computer processing of the movie images would exploit these dynamic changes to accurately measure the rapidly evolving surface waves and surface ruptures as they happen. These measurements would provide key information to advance the understanding of the mechanisms governing earthquake ruptures, and the propagation and arrest of damaging seismic waves. GSI operational strategy is to react to earthquakes detected by ground seismometers, slewing the satellite to point at the epicenters of earthquakes above a certain magnitude. Some of these earthquakes will be foreshocks of larger earthquakes; these will be observed, as the spacecraft would have been pointed in the right direction. This strategy was tested against the historical record for the Pacific coast of the Americas, from 1973 until the present. Based on the seismicity recorded during this time period, a GSI mission with a lifetime of 10 years could have been in position to observe at least 13 (22 on average) earthquakes of magnitude larger than 6, and at least one (2 on average) earthquake of magnitude larger than 7. A GSI would provide data unprecedented in its extent and temporal and spatial resolution. It would provide this data for some of the world's most seismically active regions, and do so better and at a lower cost than could be done with ground-based instrumentation. A GSI would revolutionize the understanding of earthquake dynamics, perhaps leading ultimately to effective warning

  2. Seismic capacity of a reinforced concrete frame structure without seismic detailing and limited ductility seismic design in moderate seismicity

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. K.; Kim, I. H. [Seoul National Univ., Seoul (Korea, Republic of)

    1999-10-01

    A four-story reinforced concrete frame building model is designed for the gravity loads only. Static nonlinear pushover analyses are performed in two orthogonal horizontal directions. The overall capacity curves are converted into ADRS spectra and compared with demand spectra. At several points the deformed shape, moment and shear distribution are calculated. Based on these results limited ductility seismic design concept is proposed as an alternative seismic design approach in moderate seismicity resign.

  3. Light Water Reactor Sustainability Program Advanced Seismic Soil Structure Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Bolisetti, Chandrakanth [Idaho National Lab. (INL), Idaho Falls, ID (United States); Coleman, Justin Leigh [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-06-01

    Risk calculations should focus on providing best estimate results, and associated insights, for evaluation and decision-making. Specifically, seismic probabilistic risk assessments (SPRAs) are intended to provide best estimates of the various combinations of structural and equipment failures that can lead to a seismic induced core damage event. However, in some instances the current SPRA approach has large uncertainties, and potentially masks other important events (for instance, it was not the seismic motions that caused the Fukushima core melt events, but the tsunami ingress into the facility). SPRA’s are performed by convolving the seismic hazard (this is the estimate of all likely damaging earthquakes at the site of interest) with the seismic fragility (the conditional probability of failure of a structure, system, or component given the occurrence of earthquake ground motion). In this calculation, there are three main pieces to seismic risk quantification, 1) seismic hazard and nuclear power plants (NPPs) response to the hazard, 2) fragility or capacity of structures, systems and components (SSC), and 3) systems analysis. Two areas where NLSSI effects may be important in SPRA calculations are, 1) when calculating in-structure response at the area of interest, and 2) calculation of seismic fragilities (current fragility calculations assume a lognormal distribution for probability of failure of components). Some important effects when using NLSSI in the SPRA calculation process include, 1) gapping and sliding, 2) inclined seismic waves coupled with gapping and sliding of foundations atop soil, 3) inclined seismic waves coupled with gapping and sliding of deeply embedded structures, 4) soil dilatancy, 5) soil liquefaction, 6) surface waves, 7) buoyancy, 8) concrete cracking and 9) seismic isolation The focus of the research task presented here-in is on implementation of NLSSI into the SPRA calculation process when calculating in-structure response at the area

  4. Constructing an Innovative Base-Isolation System under Masonry Structures

    OpenAIRE

    Zeeshan, Badar-Ul-Ali

    2014-01-01

    Seismic up-gradation of existing buildings is a very challenging task, as it requires us to consider historical and economical aspects of building. While proposing a seismic-retrofit scheme for a historical building, one should keep in mind that it should be compatible with existing materials, be least intrusive, monitorable and removable. A novel base-isolation technique has been proposed for the up-gradation of existing buildings against seismic actions which does not involve any alteration...

  5. Centrifuge modeling of rocking-isolated inelastic RC bridge piers

    OpenAIRE

    Loli, Marianna; Knappett, Jonathan A; Brown, Michael J.; Anastasopoulos, Ioannis; GAZETAS, George

    2014-01-01

    Experimental proof is provided of an unconventional seismic design concept, which is based on deliberately underdesigning shallow foundations to promote intense rocking oscillations and thereby to dramatically improve the seismic resilience of structures. Termed rocking isolation, this new seismic design philosophy is investigated through a series of dynamic centrifuge experiments on properly scaled models of a modern reinforced concrete (RC) bridge pier. The experimental method reproduces th...

  6. Modelling of NW Himalayan Seismicity

    Science.gov (United States)

    Bansal, A. R.; Dimri, V. P.

    2014-12-01

    The northwest Himalaya is seismicity active region due to the collision of Indian and Eurasian plates and experienced many large earthquakes in past. A systematic analysis of seismicity is useful for seismic hazard estimation of the region. We analyzed the seismicity of northwestern Himalaya since 1980. The magnitude of completeness of the catalogue is carried out using different methods and found as 3.0. A large difference in magnitude of completeness is found using different methods and a reliable value is obtained after testing the distribution of magnitudes with time. The region is prone to large earthquake and many studied have shown that seismic activation or quiescence takes place before large earthquakes. We studied such behavior of seismicity based on Epidemic Type Aftershock Sequence (ETAS) model and found that a stationary ETAS model is more suitable for modelling the seismicity of this region. The earthquake catalogue is de-clustered using stochasting approach to study behavior of background and triggered seismicity. The triggered seismicity is found to have shallower depths as compared to the background events.

  7. Flat lens for seismic waves

    CERN Document Server

    Brule, Stephane; Guenneau, Sebastien

    2016-01-01

    A prerequisite for achieving seismic invisibility is to demonstrate the ability of civil engineers to control seismic waves with artificially structured soils. We carry out large-scale field tests with a structured soil made of a grid consisting of cylindrical and vertical holes in the ground and a low frequency artificial source (< 10 Hz). This allows the identification of a distribution of energy inside the grid, which can be interpreted as the consequence of an effective negative refraction index. Such a flat lens reminiscent of what Veselago and Pendry envisioned for light opens avenues in seismic metamaterials to counteract the most devastating components of seismic signals.

  8. Neural networks in seismic discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Dowla, F.U.

    1995-01-01

    Neural networks are powerful and elegant computational tools that can be used in the analysis of geophysical signals. At Lawrence Livermore National Laboratory, we have developed neural networks to solve problems in seismic discrimination, event classification, and seismic and hydrodynamic yield estimation. Other researchers have used neural networks for seismic phase identification. We are currently developing neural networks to estimate depths of seismic events using regional seismograms. In this paper different types of network architecture and representation techniques are discussed. We address the important problem of designing neural networks with good generalization capabilities. Examples of neural networks for treaty verification applications are also described.

  9. Seismic hazard estimation of northern Iran using smoothed seismicity

    Science.gov (United States)

    Khoshnevis, Naeem; Taborda, Ricardo; Azizzadeh-Roodpish, Shima; Cramer, Chris H.

    2017-07-01

    This article presents a seismic hazard assessment for northern Iran, where a smoothed seismicity approach has been used in combination with an updated seismic catalog and a ground motion prediction equation recently found to yield good fit with data. We evaluate the hazard over a geographical area including the seismic zones of Azerbaijan, the Alborz Mountain Range, and Kopeh-Dagh, as well as parts of other neighboring seismic zones that fall within our region of interest. In the chosen approach, seismic events are not assigned to specific faults but assumed to be potential seismogenic sources distributed within regular grid cells. After performing the corresponding magnitude conversions, we decluster both historical and instrumental seismicity catalogs to obtain earthquake rates based on the number of events within each cell, and smooth the results to account for the uncertainty in the spatial distribution of future earthquakes. Seismicity parameters are computed for each seismic zone separately, and for the entire region of interest as a single uniform seismotectonic region. In the analysis, we consider uncertainties in the ground motion prediction equation, the seismicity parameters, and combine the resulting models using a logic tree. The results are presented in terms of expected peak ground acceleration (PGA) maps and hazard curves at selected locations, considering exceedance probabilities of 2 and 10% in 50 years for rock site conditions. According to our results, the highest levels of hazard are observed west of the North Tabriz and east of the North Alborz faults, where expected PGA values are between about 0.5 and 1 g for 10 and 2% probability of exceedance in 50 years, respectively. We analyze our results in light of similar estimates available in the literature and offer our perspective on the differences observed. We find our results to be helpful in understanding seismic hazard for northern Iran, but recognize that additional efforts are necessary to

  10. Seismic hazard estimation of northern Iran using smoothed seismicity

    Science.gov (United States)

    Khoshnevis, Naeem; Taborda, Ricardo; Azizzadeh-Roodpish, Shima; Cramer, Chris H.

    2017-03-01

    This article presents a seismic hazard assessment for northern Iran, where a smoothed seismicity approach has been used in combination with an updated seismic catalog and a ground motion prediction equation recently found to yield good fit with data. We evaluate the hazard over a geographical area including the seismic zones of Azerbaijan, the Alborz Mountain Range, and Kopeh-Dagh, as well as parts of other neighboring seismic zones that fall within our region of interest. In the chosen approach, seismic events are not assigned to specific faults but assumed to be potential seismogenic sources distributed within regular grid cells. After performing the corresponding magnitude conversions, we decluster both historical and instrumental seismicity catalogs to obtain earthquake rates based on the number of events within each cell, and smooth the results to account for the uncertainty in the spatial distribution of future earthquakes. Seismicity parameters are computed for each seismic zone separately, and for the entire region of interest as a single uniform seismotectonic region. In the analysis, we consider uncertainties in the ground motion prediction equation, the seismicity parameters, and combine the resulting models using a logic tree. The results are presented in terms of expected peak ground acceleration (PGA) maps and hazard curves at selected locations, considering exceedance probabilities of 2 and 10% in 50 years for rock site conditions. According to our results, the highest levels of hazard are observed west of the North Tabriz and east of the North Alborz faults, where expected PGA values are between about 0.5 and 1 g for 10 and 2% probability of exceedance in 50 years, respectively. We analyze our results in light of similar estimates available in the literature and offer our perspective on the differences observed. We find our results to be helpful in understanding seismic hazard for northern Iran, but recognize that additional efforts are necessary to

  11. The influence of backfill on seismicity

    CSIR Research Space (South Africa)

    Hemp, DA

    1990-09-01

    Full Text Available , that the seismicity has been reduced in areas where backfill had been placed. A factor complicating the evaluation of backfill on seismicity is the effect of geological structures on seismicity....

  12. Isolation, identification and expression analysis of salt-induced genes in Suaeda maritima, a natural halophyte, using PCR-based suppression subtractive hybridization

    Directory of Open Access Journals (Sweden)

    Sahu Binod B

    2009-06-01

    Full Text Available Abstract Background Despite wealth of information generated on salt tolerance mechanism, its basics still remain elusive. Thus, there is a need of continued effort to understand the salt tolerance mechanism using suitable biotechnological techniques and test plants (species to enable development of salt tolerant cultivars of interest. Therefore, the present study was undertaken to generate information on salt stress responsive genes in a natural halophyte, Suaeda maritima, using PCR-based suppression subtractive hybridization (PCR-SSH technique. Results Forward and reverse SSH cDNA libraries were constructed after exposing the young plants to 425 mM NaCl for 24 h. From the forward SSH cDNA library, 429 high quality ESTs were obtained. BLASTX search and TIGR assembler programme revealed overexpression of 167 unigenes comprising 89 singletons and 78 contigs with ESTs redundancy of 81.8%. Among the unigenes, 32.5% were found to be of special interest, indicating novel function of these genes with regard to salt tolerance. Literature search for the known unigenes revealed that only 17 of them were salt-inducible. A comparative analysis of the existing SSH cDNA libraries for NaCl stress in plants showed that only a few overexpressing unigenes were common in them. Moreover, the present study also showed increased expression of phosphoethanolamine N-methyltransferase gene, indicating the possible accumulation of a much studied osmoticum, glycinebetaine, in halophyte under salt stress. Functional categorization of the proteins as per the Munich database in general revealed that salt tolerance could be largely determined by the proteins involved in transcription, signal transduction, protein activity regulation and cell differentiation and organogenesis. Conclusion The study provided a clear indication of possible vital role of glycinebetaine in the salt tolerance process in S. maritima. However, the salt-induced expression of a large number of genes

  13. Molecular cloning and biochemical characterization of VIM-12, a novel hybrid VIM-1/VIM-2 metallo-beta-lactamase from a Klebsiella pneumoniae clinical isolate, reveal atypical substrate specificity.

    Science.gov (United States)

    Kontou, Maria; Pournaras, Spyros; Kristo, Ioulia; Ikonomidis, Alexandros; Maniatis, Antonios N; Stathopoulos, Constantinos

    2007-11-13

    Metallo-beta-lactamases (MBLs) are considered an emerging family of Zn2+-dependent enzymes that significantly contribute to the resistance of many nosocomial pathogens against beta-lactam antimicrobials. Since these plasmid-encoded enzymes constitute specific molecular targets for beta-lactams, their exact mode of action is greatly important in deploying efficient anti-infective treatments and for the control of severe multi-resistant nosocomial infections, which becomes a global problem. A novel hybrid VIM-1/VIM-2-type beta-lactamase (named VIM-12) has recently been identified in a clinical isolate of Klebsiella pneumoniae in Greece. The sequence of this enzyme is highly similar with that of VIM-1 at its N-terminal region and with that of VIM-2 at its C-terminal region, raising the question of whether this sequence similarity reflects also a similar functional role. Moreover, the possible contribution of this novel beta-lactamase to the overall antibiotic resistance of this specific clinical isolate was investigated. The gene encoding VIM-12 was cloned and expressed, and the recombinant enzyme was used for detailed kinetic analysis, using a variety of beta-lactam antibiotics. VIM-12 was found to exhibit narrow substrate specificity, compared to other known beta-lactamases, limited mainly to penicillin and to a much lesser extent to imipenen. Interestingly, meropenem was found to act as a noncompetitive inhibitor of the enzyme, although the active site of VIM-12 exhibited complete conservation of residues among VIM enzymes. We conclude that VIM-12 represents a novel and unique member of the family of known metallo-beta-lactamases, exhibiting atypical substrate specificity.

  14. 大型火力发电厂SRC框架柱-RC分散剪力墙主厂房混合结构体系抗震性能试验研究%Experimental study of the seismic performance of hybrid structure of SRC frame columns-RC disperse shear walls for large thermal power plants

    Institute of Scientific and Technical Information of China (English)

    白国良; 康灵果; 李红星; 李晓文; 赵春莲

    2011-01-01

    Considering the characteristics of a hybrid structure composed of SRC frame columns-RC disperse shear walls, a 1:7 scale model of three spans and three frames is set up to conduct pseudo-dynamic test and pseudo-static test. The results indicate that the hybrid structure can satisfy the fortification requirements of ' no damage in small earthquake, no collapse in strong earthquake' , and the displacement-load curve is plump with good energy dissipation capacity and deformation performance, with the turbine-generator operation platform in the weak floor. Overall, the hybrid structure would satisfy intensity-8 seismic fortification requirements for main buildings of large thermal power plants.%针对我国高烈度区大容量机组火力发电厂钢筋混凝土框排架主厂房“先天不足”以及钢结构主厂房造价高的现状,现提出采用型钢混凝土(SRC)框架柱—钢筋混凝土(RC)分散剪力墙混合结构体系作为主厂房框排架新型结构体系。根据该结构体系特点,选取三榀三跨结构进行1∶7比例空间模型抗震性能拟动力和拟静力试验,研究该新型结构体系在水平地震作用下的受力特点,刚度退化规律、结构滞回性能、变形性能和薄弱部位等。研究结果表明,该新型框排架结构体系能够满足“小震不坏、大震不倒”的设防要求,结构的位移-荷载滞回曲线较饱满,结构的耗能能力和变形性能较强,薄弱部位发生在汽轮发电机运转平台层处,实际设计中应加强注意。该混合结构体系能够满足8度地区大容量机组主厂房结构的抗震要求,是一种值得大力推广应用的新型结构体系。

  15. Optimal unit sizing of a hybrid renewable energy system for isolated applications; Optimalite des elements d'un systeme decentralise de production d'energie electrique

    Energy Technology Data Exchange (ETDEWEB)

    Morales, D

    2006-07-15

    In general, the methods used to conceive a renewable energy production system overestimate the size of the generating units. These methods increase the investment cost and the production cost of energy. The work presented in this thesis proposes a methodology to optimally size a renewable energy system.- This study shows that the classic approach based only on a long term analysis of system's behaviour is not sufficient and a complementary methodology based on a short term analysis is proposed. A numerical simulation was developed in which the mathematical models of the solar panel, the wind turbines and battery are integrated. The daily average solar energy per m2 is decomposed into a series of hourly I energy values using the Collares-Pereira equations. The time series analysis of the wind speed is made using the Monte Carlo Simulation Method. The second part of this thesis makes a detailed analysis of an isolated wind energy production system. The average energy produced by the system depends on the generator's rated power, the total swept area of the wind turbine, the gearbox's transformation ratio, the battery voltage and the wind speed probability function. The study proposes a methodology to determine the optimal matching between the rated power of the permanent magnet synchronous machine and the wind turbine's rotor size. This is made taking into account the average electrical energy produced over a period of time. (author)

  16. Bayesian seismic AVO inversion

    Energy Technology Data Exchange (ETDEWEB)

    Buland, Arild

    2002-07-01

    A new linearized AVO inversion technique is developed in a Bayesian framework. The objective is to obtain posterior distributions for P-wave velocity, S-wave velocity and density. Distributions for other elastic parameters can also be assessed, for example acoustic impedance, shear impedance and P-wave to S-wave velocity ratio. The inversion algorithm is based on the convolutional model and a linearized weak contrast approximation of the Zoeppritz equation. The solution is represented by a Gaussian posterior distribution with explicit expressions for the posterior expectation and covariance, hence exact prediction intervals for the inverted parameters can be computed under the specified model. The explicit analytical form of the posterior distribution provides a computationally fast inversion method. Tests on synthetic data show that all inverted parameters were almost perfectly retrieved when the noise approached zero. With realistic noise levels, acoustic impedance was the best determined parameter, while the inversion provided practically no information about the density. The inversion algorithm has also been tested on a real 3-D dataset from the Sleipner Field. The results show good agreement with well logs but the uncertainty is high. The stochastic model includes uncertainties of both the elastic parameters, the wavelet and the seismic and well log data. The posterior distribution is explored by Markov chain Monte Carlo simulation using the Gibbs sampler algorithm. The inversion algorithm has been tested on a seismic line from the Heidrun Field with two wells located on the line. The uncertainty of the estimated wavelet is low. In the Heidrun examples the effect of including uncertainty of the wavelet and the noise level was marginal with respect to the AVO inversion results. We have developed a 3-D linearized AVO inversion method with spatially coupled model parameters where the objective is to obtain posterior distributions for P-wave velocity, S

  17. Seismic failure modes and seismic safety of Hardfill dam

    Institute of Scientific and Technical Information of China (English)

    Kun XIONG; Yong-hong WENG; Yun-long HE

    2013-01-01

    Based on microscopic damage theory and the finite element method, and using the Weibull distribution to characterize the random distribution of the mechanical properties of materials, the seismic response of a typical Hardfill dam was analyzed through numerical simulation during the earthquakes with intensities of 8 degrees and even greater. The seismic failure modes and failure mechanism of the dam were explored as well. Numerical results show that the Hardfill dam remains at a low stress level and undamaged or slightly damaged during an earthquake with an intensity of 8 degrees. During overload earthquakes, tensile cracks occur at the dam surfaces and extend to inside the dam body, and the upstream dam body experiences more serious damage than the downstream dam body. Therefore, under the seismic conditions, the failure pattern of the Hardfill dam is the tensile fracture of the upstream regions and the dam toe. Compared with traditional gravity dams, Hardfill dams have better seismic performance and greater seismic safety.

  18. Isolation of genes involved in the preventive effect of electroacupuncture at Fenglong acupoint (ST40) on hypercholesterolemia mice by suppression subtractive hybridization (SSH) combined with negative subtraction chain (NSC) technology.

    Science.gov (United States)

    Li, Xingjie; Zhang, Yizheng; Yan, Wenqi; Kang, Jinmei; Kang, Yaoxia; Lie, Min

    2006-01-01

    We have shown that electroacupuncture (EA) at Fenglong acupoint (ST40) has the cholesterol-lowering effect in hypercholesterolemia mice. The present study was designed to study preventive effect of EA at ST40 on hypercholesterolemia. C57BL/6j mice were randomly divided into normal group (NG), hypercholesterolemia group (HG) and EA prevention group (EPG). NG were fed chow, HG a hypercholesterolemic diet (HD), and EPG the same HD and received EA treatment simultaneously. Lipid profile of both the plasma and liver indicated that EA at ST40 had preventive effect on hypercholesterolemia. Compared with corresponding values in the HG mice, the levels of the hepatic total cholesterol and total triglyceride in the EPG mice lowered 45% and 23% respectively, and the levels of plasma total-, LDL-, and HDL-cholesterol in the EPG mice lowered 39%, 37% and 39% respectively. Eleven genes whose expressions were up-regulated in EPG mice compared with HG were isolated using suppression subtractive hybridization (SSH) combined with negative subtraction chain (NSC) technology, and then confirmed by dot-blot assay. Except two genes whose functions were still unknown, the others were mainly involved in cholesterol metabolism, lipid metabolism, glucose metabolism and immune response. The potential molecular mechanism of preventive effect was discussed.

  19. Long term study of the seismic environment at LIGO

    CERN Document Server

    Daw, E J; Lormand, D; Lubinski, M; Zweizig, J

    2004-01-01

    The LIGO experiment aims to detect and study gravitational waves using ground based laser interferometry. A critical factor to the performance of the interferometers, and a major consideration in the design of possible future upgrades, is isolation of the interferometer optics from seismic noise. We present the results of a detailed program of measurements of the seismic environment surrounding the LIGO interferometers. We describe the experimental configuration used to collect the data, which was acquired over a 613 day period. The measurements focused on the frequency range 0.1-10 Hz, in which the secondary microseismic peak and noise due to human activity in the vicinity of the detectors was found to be particularly critical to interferometer performance. We compare the statistical distribution of the data sets from the two interferometer sites, construct amplitude spectral densities of seismic noise amplitude fluctuations with periods of up to 3 months, and analyze the data for any long term trends in the...

  20. Transdimensional Bayesian seismic ambient noise tomography across SE Tibet

    Science.gov (United States)

    Zheng, DingChang; Saygin, Erdinc; Cummins, Phil; Ge, Zengxi; Min, Zhaoxu; Cipta, Athanasius; Yang, Runhai

    2017-02-01

    We analyze seismic ambient noise data recorded at a set of permanent and temporary stations across southeastern Tibet to image crustal structure. High-resolution phase velocity maps are presented based on Transdimensional Bayesian seismic ambient noise tomography. Seismic images exhibit more apparent horizontal heterogeneities and show more detailed information compared to previous studies based on traditional ambient noise tomography. As noted from the phase velocity image at 25 s, the rigid high velocity anomalies beneath the Sichuan Basin and the South China Fold System act as a blockage to crustal material expansion, and the distribution of velocity anomalies contributes to the interpretation of a surface clockwise rotation pattern. Our results imply a more complex distributed low-velocity zone rather than two isolated channels beneath SE Tibet.

  1. Hybrid Metaheuristics

    CERN Document Server

    2013-01-01

    The main goal of this book is to provide a state of the art of hybrid metaheuristics. The book provides a complete background that enables readers to design and implement hybrid metaheuristics to solve complex optimization problems (continuous/discrete, mono-objective/multi-objective, optimization under uncertainty) in a diverse range of application domains. Readers learn to solve large scale problems quickly and efficiently combining metaheuristics with complementary metaheuristics, mathematical programming, constraint programming and machine learning. Numerous real-world examples of problems and solutions demonstrate how hybrid metaheuristics are applied in such fields as networks, logistics and transportation, bio-medical, engineering design, scheduling.

  2. Elastic-Wavefield Seismic Stratigraphy: A New Seismic Imaging Technology

    Energy Technology Data Exchange (ETDEWEB)

    Bob A. Hardage; Milo M. Backus; Michael V. DeAngelo; Sergey Fomel; Khaled Fouad; Robert J. Graebner; Paul E. Murray; Randy Remington; Diana Sava

    2006-07-31

    The purpose of our research has been to develop and demonstrate a seismic technology that will provide the oil and gas industry a better methodology for understanding reservoir and seal architectures and for improving interpretations of hydrocarbon systems. Our research goal was to expand the valuable science of seismic stratigraphy beyond the constraints of compressional (P-P) seismic data by using all modes (P-P, P-SV, SH-SH, SV-SV, SV-P) of a seismic elastic wavefield to define depositional sequences and facies. Our objective was to demonstrate that one or more modes of an elastic wavefield may image stratal surfaces across some stratigraphic intervals that are not seen by companion wave modes and thus provide different, but equally valid, information regarding depositional sequences and sedimentary facies within that interval. We use the term elastic wavefield stratigraphy to describe the methodology we use to integrate seismic sequences and seismic facies from all modes of an elastic wavefield into a seismic interpretation. We interpreted both onshore and marine multicomponent seismic surveys to select the data examples that we use to document the principles of elastic wavefield stratigraphy. We have also used examples from published papers that illustrate some concepts better than did the multicomponent seismic data that were available for our analysis. In each interpretation study, we used rock physics modeling to explain how and why certain geological conditions caused differences in P and S reflectivities that resulted in P-wave seismic sequences and facies being different from depth-equivalent S-wave sequences and facies across the targets we studied.

  3. Seismic risk perception test

    Science.gov (United States)

    Crescimbene, Massimo; La Longa, Federica; Camassi, Romano; Pino, Nicola Alessandro

    2013-04-01

    The perception of risks involves the process of collecting, selecting and interpreting signals about uncertain impacts of events, activities or technologies. In the natural sciences the term risk seems to be clearly defined, it means the probability distribution of adverse effects, but the everyday use of risk has different connotations (Renn, 2008). The two terms, hazards and risks, are often used interchangeably by the public. Knowledge, experience, values, attitudes and feelings all influence the thinking and judgement of people about the seriousness and acceptability of risks. Within the social sciences however the terminology of 'risk perception' has become the conventional standard (Slovic, 1987). The mental models and other psychological mechanisms which people use to judge risks (such as cognitive heuristics and risk images) are internalized through social and cultural learning and constantly moderated (reinforced, modified, amplified or attenuated) by media reports, peer influences and other communication processes (Morgan et al., 2001). Yet, a theory of risk perception that offers an integrative, as well as empirically valid, approach to understanding and explaining risk perception is still missing". To understand the perception of risk is necessary to consider several areas: social, psychological, cultural, and their interactions. Among the various research in an international context on the perception of natural hazards, it seemed promising the approach with the method of semantic differential (Osgood, C.E., Suci, G., & Tannenbaum, P. 1957, The measurement of meaning. Urbana, IL: University of Illinois Press). The test on seismic risk perception has been constructed by the method of the semantic differential. To compare opposite adjectives or terms has been used a Likert's scale to seven point. The test consists of an informative part and six sections respectively dedicated to: hazard; vulnerability (home and workplace); exposed value (with reference to

  4. Passive seismic experiment.

    Science.gov (United States)

    Latham, G V; Ewing, M; Press, F; Sutton, G; Dorman, J; Nakamura, Y; Toksöz, N; Wiggins, R; Derr, J; Duennebier, F

    1970-01-30

    Seismometer operation for 21 days at Tranquillity Base revealed, among strong signals produced by the Apollo 11 lunar module descent stage, a small proportion of probable natural seismic signals. The latter are long-duration, emergent oscillations which lack the discrete phases and coherence of earthquake signals. From similarity with the impact signal of the Apollo 12 ascent stage, they are thought to be produced by meteoroid impacts or shallow moonquakes. This signal character may imply transmission with high Q and intense wave scattering, conditions which are mutually exclusive on earth. Natural background noise is very much smaller than on earth, and lunar tectonism may be very low.

  5. A Mathematical Model for Suppression Subtractive Hybridization

    OpenAIRE

    2002-01-01

    Suppression subtractive hybridization (SSH) is frequently used to unearth differentially expressed genes on a whole-genome scale. Its versatility is based on combining cDNA library subtraction and normalization, which allows the isolation of sequences of varying degrees of abundance and differential expression. SSH is a complex process with many adjustable parameters that affect the outcome of gene isolation.We present a mathematical model of SSH based on DNA hybridization kinetics for assess...

  6. Seismic isolation effect of SMA Spring-Friction Bearing in concrete frame structures%SMA 弹簧-摩擦支座在混凝土框架结构中的隔震效果

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    In this paper,the SMA Spring-Friction Bearing( SFB)is applied to base isolation system for multi-story concrete frame structure. Nonlinear time history analyses of the isolated and non-isolated structures are performed by using SAP2000 software. The numerical results show that the SFB can effectively protect the frame structure from the damage of earthquake. It is also revealed that the SFB has excellent bearing dis-placement reduction performance and re-centering capability.%将SMA弹簧—摩擦支座( SFB)用于多层混凝土框架结构的基础隔震,利用SAP2000有限元软件模拟了SFB隔震结构和无控结构的地震响应,由研究结果可见,SFB能够有效保护结构免遭地震损害,并可提供良好的支座复位性能与限位能力。

  7. Seismic Data Gathering and Validation

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Justin [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-02-01

    Three recent earthquakes in the last seven years have exceeded their design basis earthquake values (so it is implied that damage to SSC’s should have occurred). These seismic events were recorded at North Anna (August 2011, detailed information provided in [Virginia Electric and Power Company Memo]), Fukushima Daichii and Daini (March 2011 [TEPCO 1]), and Kaswazaki-Kariwa (2007, [TEPCO 2]). However, seismic walk downs at some of these plants indicate that very little damage occurred to safety class systems and components due to the seismic motion. This report presents seismic data gathered for two of the three events mentioned above and recommends a path for using that data for two purposes. One purpose is to determine what margins exist in current industry standard seismic soil-structure interaction (SSI) tools. The second purpose is the use the data to validated seismic site response tools and SSI tools. The gathered data represents free field soil and in-structure acceleration time histories data. Gathered data also includes elastic and dynamic soil properties and structural drawings. Gathering data and comparing with existing models has potential to identify areas of uncertainty that should be removed from current seismic analysis and SPRA approaches. Removing uncertainty (to the extent possible) from SPRA’s will allow NPP owners to make decisions on where to reduce risk. Once a realistic understanding of seismic response is established for a nuclear power plant (NPP) then decisions on needed protective measures, such as SI, can be made.

  8. Procedures for computing site seismicity

    Science.gov (United States)

    Ferritto, John

    1994-02-01

    This report was prepared as part of the Navy's Seismic Hazard Mitigation Program. The Navy has numerous bases located in seismically active regions throughout the world. Safe effective design of waterfront structures requires determining expected earthquake ground motion. The Navy's problem is further complicated by the presence of soft saturated marginal soils that can significantly amplify the levels of seismic shaking as evidenced in the 1989 Loma Prieta earthquake. The Naval Facilities Engineering Command's seismic design manual, NAVFAC P355.l, requires a probabilistic assessment of ground motion for design of essential structures. This report presents the basis for the Navy's Seismic Hazard Analysis procedure that was developed and is intended to be used with the Seismic Hazard Analysis computer program and user's manual. This report also presents data on geology and seismology to establish the background for the seismic hazard model developed. The procedure uses the historical epicenter data base and available geologic data, together with source models, recurrence models, and attenuation relationships to compute the probability distribution of site acceleration and an appropriate spectra. This report discusses the developed stochastic model for seismic hazard evaluation and the associated research.

  9. Key aspects governing induced seismicity

    Science.gov (United States)

    Buijze, Loes; Wassing, Brecht; Fokker, Peter

    2013-04-01

    In the past decades numerous examples of earthquakes induced by human-induced changes in subsurface fluid pressures have been reported. This poses a major threat to the future development of some of these operations and calls for an understanding and quantification of the seismicity generated. From geomechanical considerations and insights from laboratory experiments the factors controlling induced seismicity may be grouped into 4 categories; the magnitude of the stress disturbance, the pre-existing stress conditions, the reservoir/fault rock properties and the local geometry. We investigated whether the (relative) contributions of these factors and their influence on magnitudes generated could be recognized by looking at the entire dataset of reported cases of induced seismicity as a whole, and what this might imply for future developments. An extensive database has been built out of over a 160 known cases of induced seismicity worldwide, incorporating the relevant geological, seismological and fluid-related parameters. The cases studied include hydrocarbon depletion and secondary recovery, waste water injection, (enhanced) geothermal systems and hydraulic fracturing with observed magnitudes ranging from less than -1.5 to 7. The parameters taken into account were based on the theoretical background of the mechanisms of induced seismicity and include the injection/depletion-related parameters, (spatial) characteristics of seismicity, lithological properties and the local stress situation. Correlations between the seismic response and the geological/geomechanical characteristics of the various sites were investigated. The injected/depleted volumes and the scale of the activities are major controlling factors on the maximum magnitudes generated. Spatial signatures of seismicity such as the depth and lateral spread of the seismicity were observed to be distinct for different activities, which is useful when considering future operations. Where available the local

  10. Manuel Rocha Medal recipient - A relative moment tensor inversion technique applied to seismicity induced by mining

    CSIR Research Space (South Africa)

    Linzer, LM

    2005-04-01

    Full Text Available The primary objective of this study was to develop a robust MTI method to estimate the moment tensors of clusters of seismic events recorded in the underground environment. To achieve this, three 'hybrid' MTI methods were developed by the author...

  11. Advances in Rotational Seismic Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Pierson, Robert [Applied Technology Associates, Albuquerque, NM (United States); Laughlin, Darren [Applied Technology Associates, Albuquerque, NM (United States); Brune, Robert [Applied Technology Associates, Albuquerque, NM (United States)

    2016-10-19

    Rotational motion is increasingly understood to be a significant part of seismic wave motion. Rotations can be important in earthquake strong motion and in Induced Seismicity Monitoring. Rotational seismic data can also enable shear selectivity and improve wavefield sampling for vertical geophones in 3D surveys, among other applications. However, sensor technology has been a limiting factor to date. The US Department of Energy (DOE) and Applied Technology Associates (ATA) are funding a multi-year project that is now entering Phase 2 to develop and deploy a new generation of rotational sensors for validation of rotational seismic applications. Initial focus is on induced seismicity monitoring, particularly for Enhanced Geothermal Systems (EGS) with fracturing. The sensors employ Magnetohydrodynamic (MHD) principles with broadband response, improved noise floors, robustness, and repeatability. This paper presents a summary of Phase 1 results and Phase 2 status.

  12. Effectiveness of Base Isolation Technique and Influence of Isolator Characteristics on Response of a Base Isolated Building

    Directory of Open Access Journals (Sweden)

    Sunita Tolani

    2016-06-01

    Full Text Available This study concerns with the seismic response comparison of a fixed base building with a base isolated building and parametric study of a base isolated building. The structural system considered for analysis is a three storey reinforced concrete building, which is idealized as a shear type building with one lateral degree of freedom at each floor level. The isolation systems considered for this study are Laminated Rubber bearing (LRB, Lead Rubber Bearing (N-Z bearing and Friction Pendulum System (FPS. The response of fixed base building and of base isolated building is compared in terms of maximum top floor acceleration, interstorey drift, maximum floor displacements and base shear. For parametric study important isolation system parameters considered are: (i isolation time period, isolator damping for LRB; (ii isolator yield strength, isolation time period, isolator damping for N-Z bearing and (iii isolation time period, friction coefficient for FPS. It is found that base isolation technique is very effective in reducing seismic response of structure and isolation system parameters significantly influence the earthquake response of a base isolated structure.

  13. Hybrid intermediaries

    OpenAIRE

    Cetorelli, Nicola

    2014-01-01

    I introduce the concept of hybrid intermediaries: financial conglomerates that control a multiplicity of entity types active in the "assembly line" process of modern financial intermediation, a system that has become known as shadow banking. The complex bank holding companies of today are the best example of hybrid intermediaries, but I argue that financial firms from the "nonbank" space can just as easily evolve into conglomerates with similar organizational structure, thus acquiring the cap...

  14. Hybrid composites

    CSIR Research Space (South Africa)

    Jacob John, Maya

    2009-04-01

    Full Text Available effect was observed for the elongation at break of the hybrid composites. The impact strength of the hybrid composites increased with the addition of glass fibres. The tensile and impact properties of thermoplastic natural rubber reinforced short... panels made from conventional structural materials. Figure 3 illustrates the performance of cellular biocomposite panels against conventional systems used for building and residential construction, namely a pre- cast pre-stressed hollow core concrete...

  15. Seismic moulin tremor

    Science.gov (United States)

    Roeoesli, Claudia; Walter, Fabian; Ampuero, Jean-Paul; Kissling, Edi

    2016-08-01

    Through glacial moulins, meltwater is routed from the glacier surface to its base. Moulins are a main feature feeding subglacial drainage systems and thus influencing basal motion and ice dynamics, but their geometry remains poorly known. Here we show that analysis of the seismic wavefield generated by water falling into a moulin can help constrain its geometry. We present modeling results of hour-long seimic tremors emitted from a vertical moulin shaft, observed with a seismometer array installed at the surface of the Greenland Ice Sheet. The tremor was triggered when the moulin water level exceeded a certain height, which we associate with the threshold for the waterfall to hit directly the surface of the moulin water column. The amplitude of the tremor signal changed over each tremor episode, in close relation to the amount of inflowing water. The tremor spectrum features multiple prominent peaks, whose characteristic frequencies are distributed like the resonant modes of a semiopen organ pipe and were found to depend on the moulin water level, consistent with a source composed of resonant tube waves (water pressure waves coupled to elastic deformation of the moulin walls) along the water-filled moulin pipe. Analysis of surface particle motions lends further support to this interpretation. The seismic wavefield was modeled as a superposition of sustained wave radiation by pressure sources on the side walls and at the bottom of the moulin. The former was found to dominate the wave field at close distance and the latter at large distance to the moulin.

  16. The provision of electricity through a photovoltaic-wind hybrid system in an isolated community in the Jalapao, municipality of Mateiros, state of Tocantins, Brazil; A disponibilizacao de energia eletrica atraves de um sistema hibrido eolico-fotovoltaico em uma comunidade isolada na regiao do Jalapao, municipio de Mateiros, estado do Tocantins

    Energy Technology Data Exchange (ETDEWEB)

    Zukowski Junior, J.C.; Santos, W.F.; Nobrega, S.L. de; Marcon, R.O. [Universidade Luterana do Brasil (CEULP/ULBRA), Palmas, TO (Brazil). Centro Universitario Luterano de Palmas. Curso de Engenharia Agricola], Emails: zukowski@uft.edu.br, olavo@ulbra-to.br, silvestre@ulbra-to.br

    2009-07-01

    Nowadays Brazil has many isolated communities. This isolation occurs mainly due to territorial conditions. Besides this aspect, the lack of structure produces another isolation, much more harmful, the social one. To promote social inclusion and sustainable development, some requirements are essential. Amongst all of them, the provision of electricity is the most prominent. This study aimed to provide electricity to an isolated community in the Jalapao region, Mateiros city, in the state of Tocantins. It was installed a hybrid aeolian-photovoltaic system, with capacity to produce 9676.80 kWh per year. This electricity system aims to improve the production process, so it was installed at the local community workshop. The results indicate that the system can be sustainable if the community makes use of the electricity generation, using it in the production process. (author)

  17. Annual Hanford Seismic Report for Fiscal Year 1998

    Energy Technology Data Exchange (ETDEWEB)

    DC Hartshorn; SP Reidel; AC Rohay

    1998-12-22

    Seismic monitoring at the Hanford Site was established in 1969 by the United States Geological Survey (USGS) under a contract with theJ.J.S. Atomic Energy Commission. In 1975, the University of Washington (UW) assumed responsibility for the network and subsequently expanded it. In 1979, the Basalt Waste o Isolation Program (13WIP) became responsible for collecting seismic data for the Hdord Site as part of site " characterization activities. Rockwell Htiord Operations, followed by Westinghouse Ha&ord Company . (WHC), operated the local network and were the contract technical advisors for the Eastern Washington Regional Network @wRN) operated and maintained by the UW. Funding for BWIP ended in December 1988. Seismic Monitoring and responsibility for the University of Washington contract were then trans- ferred to WHC'S Environmental Division. Maintenance responsibilities for the EWRN were also Assigned to WHC, who made major upgrades to EWRN sites. Effective October 1,1996, Seismic Monitoring was transfemed to the Pacific Northwest National Laboratory (PI@lL*). Seismic Monitoring is part of PNNL's Applied Geology and Geochemistry Group, Energy Technology Division. The Hanford Strong Motion Accelerometer network was constructed during 1997 and came online in May 1997. It operated continuously until September 30, 1997, when it was mothballed due to can- . cellation of fimding. Funding was restored on October 1, 1998, by joint agreement between the U.S. Department of Energy (DOE) and PNNL. Operation of the free-field sites resumed on November 20, 1998.

  18. Seismic fragility analysis of Inter-story isolation structures based on response surface method%基于响应面法的层间隔震结构地震易损性分析

    Institute of Scientific and Technical Information of China (English)

    张尚荣; 谭平; 杜永峰; 周福霖; 赵丽洁

    2014-01-01

    考虑地震动和结构物理参数不确定性,提出一种基于响应面法的层间隔震结构地震易损性分析方法。以中心复合设计方法建立地震动-层间隔震结构样本,对系统样本模型进行非线性动力时程分析,分别建立层间隔震结构各子结构的响应面模型,在此基础上采用蒙特卡洛模拟获得易损性曲线。分析结果表明,提出的方法计算量少、精度高,有效提高了易损性分析作为层间隔震结构性能评估的时效性,具有较大的工程应用前景。%Considering the uncertainties of ground motions characteristics and structural parameters,a fragility analysis method of inter-story isolation structures based on RSM(response surface method)was proposed.Using the central composite design method to construct a series of samples for various ground motions and inter-story isolation structures,nonlinear dynamic time-history analyses of the sample models were performed,and then the substructure response surface models of an inter-story isolation structure were built.Its fragility curve was obtained with Monte Carlo simulation method.Analysis results showed that the proposed method has less amount of calculation,and a higher accuracy to effectively improve the efficiency of a vulnerability analysis,and it has engineering application prospects.

  19. seismic-py: Reading seismic data with Python

    Directory of Open Access Journals (Sweden)

    2008-08-01

    Full Text Available The field of seismic exploration of the Earth has changed
    dramatically over the last half a century. The Society of Exploration
    Geophysicists (SEG has worked to create standards to store the vast
    amounts of seismic data in a way that will be portable across computer
    architectures. However, it has been impossible to predict the needs of the
    immense range of seismic data acquisition systems. As a result, vendors have
    had to bend the rules to accommodate the needs of new instruments and
    experiment types. For low level access to seismic data, there is need for a
    standard open source library to allow access to a wide range of vendor data
    files that can handle all of the variations. A new seismic software package,
    seismic-py, provides an infrastructure for creating and managing drivers for
    each particular format. Drivers can be derived from one of the known formats
    and altered to handle any slight variations. Alternatively drivers can be
    developed from scratch for formats that are very different from any previously
    defined format. Python has been the key to making driver development easy
    and efficient to implement. The goal of seismic-py is to be the base system
    that will power a wide range of experimentation with seismic data and at the
    same time provide clear documentation for the historical record of seismic
    data formats.

  20. Updated Colombian Seismic Hazard Map

    Science.gov (United States)

    Eraso, J.; Arcila, M.; Romero, J.; Dimate, C.; Bermúdez, M. L.; Alvarado, C.

    2013-05-01

    The Colombian seismic hazard map used by the National Building Code (NSR-98) in effect until 2009 was developed in 1996. Since then, the National Seismological Network of Colombia has improved in both coverage and technology providing fifteen years of additional seismic records. These improvements have allowed a better understanding of the regional geology and tectonics which in addition to the seismic activity in Colombia with destructive effects has motivated the interest and the need to develop a new seismic hazard assessment in this country. Taking advantage of new instrumental information sources such as new broad band stations of the National Seismological Network, new historical seismicity data, standardized global databases availability, and in general, of advances in models and techniques, a new Colombian seismic hazard map was developed. A PSHA model was applied. The use of the PSHA model is because it incorporates the effects of all seismic sources that may affect a particular site solving the uncertainties caused by the parameters and assumptions defined in this kind of studies. First, the seismic sources geometry and a complete and homogeneous seismic catalog were defined; the parameters of seismic rate of each one of the seismic sources occurrence were calculated establishing a national seismotectonic model. Several of attenuation-distance relationships were selected depending on the type of seismicity considered. The seismic hazard was estimated using the CRISIS2007 software created by the Engineering Institute of the Universidad Nacional Autónoma de México -UNAM (National Autonomous University of Mexico). A uniformly spaced grid each 0.1° was used to calculate the peak ground acceleration (PGA) and response spectral values at 0.1, 0.2, 0.3, 0.5, 0.75, 1, 1.5, 2, 2.5 and 3.0 seconds with return periods of 75, 225, 475, 975 and 2475 years. For each site, a uniform hazard spectrum and exceedance rate curves were calculated. With the results, it is

  1. The suppression of coherent noise from another airgun source in marine multi-channel seismic data

    Science.gov (United States)

    Hsu, Ho-Han; Liu, Char-Shine; Chang, Jih-Hsin; Tsai, You-Tsung; Chiu, Shye-Donq

    2016-12-01

    During seismic investigations, multiple and unexpected sources may cause serious interference on seismic records, and coherent noise generated by another unwanted active source could result in extremely poor data quality. Because airgun arrays have been widely used as the sound source in marine seismic surveys, the noise generated by another airgun array usually has similar characteristics to the primary signals in both frequency bands and wave forms, so the suppression of this type of coherent noise is very difficult. In practice, seismic crews try to avoid conducting multiple surveys simultaneously in a same area, so the source interference problem normally does not occur, and suppression of coherent noise from another active source has rarely been discussed and proposed before. This paper presents a dataset in which part of the records are contaminated by shot noise from another seismic vessel, and proposes a hybrid approach to suppress the coherent noise from that unwanted seismic source. Noise subtraction and primary signal preservation within different data properties are considered to begin the noise suppression. Based on different noise characteristics from various source directions and wave propagation paths, coherence noise can be separated from primary signals in frequency-wave number (F-K), frequency-time (F-T) and intercept time-slowness (tau-p) domains, respectively. This hybrid coherent noise suppression approach involves applying three different filters, F-K, F-T and tau-p, to the contaminated dataset. Our results show that most of the coherent noise generated by another seismic source could be suppressed, and seismic images could be substantially improved.

  2. Midget Seismic in Sandbox Models

    Science.gov (United States)

    Krawczyk, C. M.; Buddensiek, M. L.; Philipp, J.; Kukowski, N.; Oncken, O.

    2008-12-01

    Analog sandbox simulation has been applied to study geological processes to provide qualitative and quantitative insights into specific geological problems. In nature, the structures, which are simulated in those sandbox models, are often inferred from seismic data. With the study introduced here, we want to combine the analog sandbox simulation techniques with seismic physical modeling of those sandbox models. The long-term objectives of this approach are (1) imaging of seismic and seismological events of actively deforming and static 3D analogue models, and (2) assessment of the transferability of the model data to field data in order to improve field data acquisition and interpretation according to the addressed geological problem. To achieve this objective, a new midget-seismic facility for laboratory use was designed and developed, comprising a seismic tank, a PC control unit including piezo-electric transducers, and a positioning system. The first experiments are aimed at studying the wave field properties of the piezo- transducers in order to investigate their feasibility for seismic profiling. The properties investigated are their directionality and the change of waveform due to their size (5-12 mm) compared to the wavelengths (material properties and the effects of wave propagation in an-/isotropic media by physical studies, before we finally start using different seismic imaging and processing techniques on static and actively deforming 3D analog models.

  3. Seismic hazard assessment: Issues and alternatives

    Science.gov (United States)

    Wang, Z.

    2011-01-01

    Seismic hazard and risk are two very important concepts in engineering design and other policy considerations. Although seismic hazard and risk have often been used inter-changeably, they are fundamentally different. Furthermore, seismic risk is more important in engineering design and other policy considerations. Seismic hazard assessment is an effort by earth scientists to quantify seismic hazard and its associated uncertainty in time and space and to provide seismic hazard estimates for seismic risk assessment and other applications. Although seismic hazard assessment is more a scientific issue, it deserves special attention because of its significant implication to society. Two approaches, probabilistic seismic hazard analysis (PSHA) and deterministic seismic hazard analysis (DSHA), are commonly used for seismic hazard assessment. Although PSHA has been pro-claimed as the best approach for seismic hazard assessment, it is scientifically flawed (i.e., the physics and mathematics that PSHA is based on are not valid). Use of PSHA could lead to either unsafe or overly conservative engineering design or public policy, each of which has dire consequences to society. On the other hand, DSHA is a viable approach for seismic hazard assessment even though it has been labeled as unreliable. The biggest drawback of DSHA is that the temporal characteristics (i.e., earthquake frequency of occurrence and the associated uncertainty) are often neglected. An alternative, seismic hazard analysis (SHA), utilizes earthquake science and statistics directly and provides a seismic hazard estimate that can be readily used for seismic risk assessment and other applications. ?? 2010 Springer Basel AG.

  4. Hybrid slab-microchannel gel electrophoresis system

    Science.gov (United States)

    Balch, Joseph W.; Carrano, Anthony V.; Davidson, James C.; Koo, Jackson C.

    1998-01-01

    A hybrid slab-microchannel gel electrophoresis system. The hybrid system permits the fabrication of isolated microchannels for biomolecule separations without imposing the constraint of a totally sealed system. The hybrid system is reusable and ultimately much simpler and less costly to manufacture than a closed channel plate system. The hybrid system incorporates a microslab portion of the separation medium above the microchannels, thus at least substantially reducing the possibility of non-uniform field distribution and breakdown due to uncontrollable leakage. A microslab of the sieving matrix is built into the system by using plastic spacer materials and is used to uniformly couple the top plate with the bottom microchannel plate.

  5. Seismic modeling of carbonate outcrops

    Energy Technology Data Exchange (ETDEWEB)

    Stafleu, J.; Schlager, W.; Campbell, E.; Everts, A.J. (Vrije Universiteit, Amsterdam (Netherlands))

    1993-09-01

    Traditionally, seismic modeling has concentrated on one-dimensional borehole modeling and two-dimensional forward modeling of basic structural-stratigraphic schemes, which are directly compared with real seismic data. Two-dimensional seismic models based on outcrop observations may aid in bridging the gap between the detail of the outcrop and the low resolution of seismic lines. Examples include the Dolomites (north Italy), the High Atlas (Morocco), the Vercors (southeast France) and the Last chance Canyon (New Mexico). The seismic models generally are constructed using the following procedure: (1) construction of a detailed lithological model based on direct outcrop observations; (2) division of the lithological model into lithostratigraphic units, using master bedding planes and important facies transitions as boundaries; (3) assignment of petrophysical properties of these lithostratigraphic units; (4) computation of time sections of reflectivity, using different modeling techniques; and (5) convolution with source wavelets of different frequencies. The lithological detail modeled in the case studies lead to some striking results, particularly the discovery of pseudo-unconformities. Pseudo-unconformities are unconformities in seismics, but correspond to rapid changes of dip and facies in outcrop. None of the outcrop geometries studied were correctly portrayed seismically at 25 Hz frequency. However, in some instances the true relationship would emerge gradually at frequencies of 50 to 100 Hz. These results demonstrate that detailed, outcrop-derived/seismic models can reveal what stratigraphic relationships and features are likely to be resolved under ideal or less ideal conditions, and what pitfalls may befall the interpreter of real seismic data.

  6. Integrated system for seismic evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Xu, J.; Philippacopoulos, A.J.; Miller, C.A.; Costantino, C.J.; Graves, H.

    1989-01-01

    This paper describes the various features of the Seismic Module of the CARES system (Computer Analysis for Rapid Evaluation of Structures). This system was developed by Brookhaven National Laboratory (BNL) for the US Nuclear Regulatory Commission to perform rapid evaluations of structural behavior and capability of nuclear power plant facilities. The CARES is structured in a modular format. Each module performs a specific type of analysis i.e., static or dynamic, linear or nonlinear, etc. This paper describes the features of the Seismic Module in particular. The development of the Seismic Module of the CARES system is based on an approach which incorporates all major aspects of seismic analysis currently employed by the industry into an integrated system that allows for carrying out interactively computations of structural response to seismic motions. The code operates on a PC computer system and has multi-graphics capabilities. It has been designed with user friendly features and it allows for interactive manipulation of various analysis phases during the seismic design process. The capabilities of the seismic module include (a) generation of artificial time histories compatible with given design ground response spectra, (b) development of Power Spectral Density (PSD) functions associated with the seismic input, (c) deconvolution analysis using vertically propagating shear waves through a given soil profile, and (d) development of in-structure response spectra or corresponding PSD's. It should be pointed out that these types of analyses can also be performed individually by using available computer codes such as FLUSH, SAP, etc. The uniqueness of the CARES, however, lies on its ability to perform all required phases of the seismic analysis in an integrated manner. 5 refs., 6 figs.

  7. Scenarios for Evolving Seismic Crises: Possible Communication Strategies

    Science.gov (United States)

    Steacy, S.

    2015-12-01

    Recent advances in operational earthquake forecasting mean that we are very close to being able to confidently compute changes in earthquake probability as seismic crises develop. For instance, we now have statistical models such as ETAS and STEP which demonstrate considerable skill in forecasting earthquake rates and recent advances in Coulomb based models are also showing much promise. Communicating changes in earthquake probability is likely be very difficult, however, as the absolute probability of a damaging event is likely to remain quite small despite a significant increase in the relative value. Here, we use a hybrid Coulomb/statistical model to compute probability changes for a series of earthquake scenarios in New Zealand. We discuss the strengths and limitations of the forecasts and suggest a number of possible mechanisms that might be used to communicate results in an actual developing seismic crisis.

  8. Hybrid sterility in plant: stories from rice.

    Science.gov (United States)

    Ouyang, Yidan; Liu, Yao-Guang; Zhang, Qifa

    2010-04-01

    Hybrid sterility is the most common form of postzygotic reproductive isolation in plants. The best-known example is perhaps the hybrid sterility between indica and japonica subspecies of Asian cultivated rice (Oryza sativa L.). Major progress has been reported recently in rice in identifying and cloning hybrid sterility genes at two loci regulating female and male fertility, respectively. Genetic analyses and molecular characterization of these genes, together with the results from other model organisms especially Drosophila, have advanced the understanding of the processes underlying reproductive isolation and speciation. These findings also have significant implications for crop genetic improvement, by providing the feasibility and strategies for overcoming intersubspecific hybrid sterility thus allowing the development of intersubspecific hybrids.

  9. Seismic calm predictors of rockburst

    Science.gov (United States)

    Zmushko, Tatjana; Turuntaev, Sergey; Kulikov, Vladimir

    2013-04-01

    The method of "seismic calm" is widely used for forecasting of strong natural earthquakes (Sobolev G.A., Ponomarev A.V., 2003). The "seismic calm" means that during some time period before the main earthquake, the smaller events (with energies of several order smaller than that of the main earthquake) don't occur. In the presented paper the applicability of the method based on the idea of seismic calm for forecasting rockburst is considered. Three deposits (with seismicity induced by mining) are analyzed: Tashtagol iron deposit (Altai, Russia), Vorkuta (North Ural, Russia) and Barentsburg (Spitsbergen, Norway) coalmines. Local seismic monitoring networks are installed on each of them. The catalogues of seismic events were processed and strong events (rockbursts) were studied (Vorkuta M=2,3; Barentsburg M=1,8; Tashtagol M=1,9÷2,2). All catalogues cover at least two years (Vorkuta - 2008-2011, Barentsburg - 2011-2012, Tashtagol - 2002-2012). It was found that the number of seismic events with magnitudes M=0,5÷1 decreased in a month before the main strong event at Vorkuta coalmines. This event was not directly related with coal mining, its epicenter was located aside of the area of coal mining. In Barentsburg mine the rockburst wasn't so strong as in Vorkuta. The number of events with energies M=0,5 decreased slightly before the rockburst, but not so obviously as in Vorkuta case. The seismic events with high energies occur often at Tashtagol iron deposit. Mining methods used there differ from the coal deposit mining. At coalmines the mining combine runs from edge to edge of the wall, cutting off the coal. The considered iron deposit is developed by a method of block blasting. Not all rockbursts occur immediately after the blasting, so, the problem of the rockburst prediction is important for mining safety. To find rockburst precursors it is necessary to separate the events occurred due to the block blasting from the seismic events due to relocation of stresses in

  10. Automating Shallow Seismic Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Steeples, Don W.

    2004-12-09

    This seven-year, shallow-seismic reflection research project had the aim of improving geophysical imaging of possible contaminant flow paths. Thousands of chemically contaminated sites exist in the United States, including at least 3,700 at Department of Energy (DOE) facilities. Imaging technologies such as shallow seismic reflection (SSR) and ground-penetrating radar (GPR) sometimes are capable of identifying geologic conditions that might indicate preferential contaminant-flow paths. Historically, SSR has been used very little at depths shallower than 30 m, and even more rarely at depths of 10 m or less. Conversely, GPR is rarely useful at depths greater than 10 m, especially in areas where clay or other electrically conductive materials are present near the surface. Efforts to image the cone of depression around a pumping well using seismic methods were only partially successful (for complete references of all research results, see the full Final Technical Report, DOE/ER/14826-F), but peripheral results included development of SSR methods for depths shallower than one meter, a depth range that had not been achieved before. Imaging at such shallow depths, however, requires geophone intervals of the order of 10 cm or less, which makes such surveys very expensive in terms of human time and effort. We also showed that SSR and GPR could be used in a complementary fashion to image the same volume of earth at very shallow depths. The primary research focus of the second three-year period of funding was to develop and demonstrate an automated method of conducting two-dimensional (2D) shallow-seismic surveys with the goal of saving time, effort, and money. Tests involving the second generation of the hydraulic geophone-planting device dubbed the ''Autojuggie'' showed that large numbers of geophones can be placed quickly and automatically and can acquire high-quality data, although not under rough topographic conditions. In some easy

  11. Nonlinear seismic response analysis of direct air-cooled vertical hybrid structures with diagonal bracing%带斜撑型直接空冷钢-混凝土竖向混合结构非线性地震响应分析

    Institute of Scientific and Technical Information of China (English)

    代慧娟; 白国良; 王博; 张淑云; 董叶辉

    2015-01-01

    Steel-concrete vertical hybrid structure with diagonal bracing is a new structure system which has been proposed for applying the direct air-cooled technology in high earthquake intensity areas,according to the type of platform. The structure can be divided into two types:steel truss-diagonal bracing structure and solid web girder-diagonal bracing structure.On the basis of the seismic experiments of steel truss-diagonal bracing model structures,finite element software ABAQUS was used to calculate and analyze the base shear response,deformation properties and damage evolution characteristics of reinforced concrete pipe columns of the two kinds of structures with diagonal bracing.The results show that:the proposed simplification principles and finite element modeling methods are reasonable,the calculated results agree well with the test results;under different earthquake intensities,the biggest base shear force and the shear-weight ratio of the steel truss-diagonal bracing structure are greater than those of the solid web girder-diagonal structure;the lateral displacement curves for the two kinds of structures are both shifting from shear-moment-type toward shear-type as the earthquake intensity increases;the lateral displacements on and below the corbel of the steel truss-diagonal bracing structure is slightly greater than those of the solid web girder-diagonal structure,while above the corbel,it is just the opposite;the lateral displacement angle at the top of the column for the steel truss-diagonal bracing structure is slightly smaller than that of the solid web girder-diagonal structure;seismic performances of the two kinds of structures are both good,which can meet the seismic requirement of the large-capacity units in high earthquake intensity areas.%带斜撑型钢-混凝土竖向混合结构是为将直接空冷技术推广应用于高烈度地区而提出的一种新型结构体系,根据上部结构平台型式的不同,可分为钢桁架+斜撑结

  12. Advanced Seismic While Drilling System

    Energy Technology Data Exchange (ETDEWEB)

    Robert Radtke; John Fontenot; David Glowka; Robert Stokes; Jeffery Sutherland; Ron Evans; Jim Musser

    2008-06-30

    A breakthrough has been discovered for controlling seismic sources to generate selectable low frequencies. Conventional seismic sources, including sparkers, rotary mechanical, hydraulic, air guns, and explosives, by their very nature produce high-frequencies. This is counter to the need for long signal transmission through rock. The patent pending SeismicPULSER{trademark} methodology has been developed for controlling otherwise high-frequency seismic sources to generate selectable low-frequency peak spectra applicable to many seismic applications. Specifically, we have demonstrated the application of a low-frequency sparker source which can be incorporated into a drill bit for Drill Bit Seismic While Drilling (SWD). To create the methodology of a controllable low-frequency sparker seismic source, it was necessary to learn how to maximize sparker efficiencies to couple to, and transmit through, rock with the study of sparker designs and mechanisms for (a) coupling the sparker-generated gas bubble expansion and contraction to the rock, (b) the effects of fluid properties and dynamics, (c) linear and non-linear acoustics, and (d) imparted force directionality. After extensive seismic modeling, the design of high-efficiency sparkers, laboratory high frequency sparker testing, and field tests were performed at the University of Texas Devine seismic test site. The conclusion of the field test was that extremely high power levels would be required to have the range required for deep, 15,000+ ft, high-temperature, high-pressure (HTHP) wells. Thereafter, more modeling and laboratory testing led to the discovery of a method to control a sparker that could generate low frequencies required for deep wells. The low frequency sparker was successfully tested at the Department of Energy Rocky Mountain Oilfield Test Center (DOE RMOTC) field test site in Casper, Wyoming. An 8-in diameter by 26-ft long SeismicPULSER{trademark} drill string tool was designed and manufactured by TII

  13. Shaking Table Tests of Curved Bridge considering Bearing Friction Sliding Isolation

    Directory of Open Access Journals (Sweden)

    Lei Yan

    2016-01-01

    Full Text Available Specific to severe damage to curved bridges in earthquakes caused by the excessive force of the fixed bearings and piers, a new seismic design method on curved bridges considering bearing friction sliding isolation is proposed in this paper. Seismic model bridge and isolation model bridge with similarity ratio of 1/20 were made and the shaking table comparison test was conducted. The experimental results show that the isolation model curved bridge suffered less seismic damage than the seismic model curved bridge. The fundamental frequencies of the seismic model bridge and isolation model bridge decreased and the damping ratio increased with the increase of seismic intensity. Compared with seismic curved bridge, the maximum reduction rates of peak acceleration along the radial and tangential directions on the top of pier of the isolation model curved bridge were 47.3% and 55.5%, respectively, and the maximum reduction rate of the peak strain on the bottom of pier of the isolation model curved bridge was 43.4%. For the isolation model curved bridge, the maximum reduction rate of peak acceleration on the top of pier was 24.6% compared with that on the bottom of pier. The study results can provide experimental basis for the seismic design of curved bridges.

  14. Reevaluation of the Seismicity and seismic hazards of Northeastern Libya

    Science.gov (United States)

    Ben Suleman, abdunnur; Aousetta, Fawzi

    2014-05-01

    Libya, located at the northern margin of the African continent, underwent many episodes of orogenic activities. These episodes of orogenic activities affected and shaped the geological setting of the country. This study represents a detailed investigation that aims to focus on the seismicity and its implications on earthquake hazards of Northeastern Libya. At the end of year 2005 the Libyan National Seismological Network starts functioning with 15 stations. The Seismicity of the area under investigation was reevaluated using data recorded by the recently established network. The Al-Maraj earthquake occurred in May 22nd 2005was analyzed. This earthquake was located in a known seismically active area. This area was the sight of the well known 1963 earthquake that kills over 200 people. Earthquakes were plotted and resulting maps were interpreted and discussed. The level of seismic activity is higher in some areas, such as the city of Al-Maraj. The offshore areas north of Al-Maraj seem to have higher seismic activity. It is highly recommended that the recent earthquake activity is considered in the seismic hazard assessments for the northeastern part of Libya.

  15. Validating induced seismicity forecast models - Induced Seismicity Test Bench

    CERN Document Server

    Kiraly-Proag, Eszter; Gischig, Valentin; Wiemer, Stefan; Karvounis, Dimitrios; Doetsch, Joseph

    2016-01-01

    Induced earthquakes often accompany fluid injection, and the seismic hazard they pose threatens various underground engineering projects. Models to monitor and control induced seismic hazard with traffic light systems should be probabilistic, forward-looking, and updated as new data arrive. In this study, we propose an Induced Seismicity Test Bench to test and rank such models; this test bench can be used for model development, model selection, and ensemble model building. We apply the test bench to data from the Basel 2006 and Soultz-sous-For\\^ets 2004 geothermal stimulation projects, and we assess forecasts from two models: Shapiro and Smoothed Seismicity (SaSS) and Hydraulics and Seismics (HySei). These models incorporate a different mix of physics-based elements and stochastic representation of the induced sequences. Our results show that neither model is fully superior to the other. Generally, HySei forecasts the seismicity rate better after shut-in, but is only mediocre at forecasting the spatial distri...

  16. Vegetative propagation of Alstroemeria hybrids in vitro.

    NARCIS (Netherlands)

    Pierik, R.L.M.; Voorst, van A.; Booy, G.; Acker, van C.A.M.; Lelivelt, C.L.C.; Wit, de J.C.

    1988-01-01

    Terminal and lateral tips from fleshy rhizomes of Alstroemeria hybrids were isolated in vitro and induced to form a new rhizome. The cultivar Toledo was used in most experiments, but later other cultivars were also tested. The basic culture medium for rhizome isolation and for rhizome multiplication

  17. Vegetative propagation of Alstroemeria hybrids in vitro.

    NARCIS (Netherlands)

    Pierik, R.L.M.; Voorst, van A.; Booy, G.; Acker, van C.A.M.; Lelivelt, C.L.C.; Wit, de J.C.

    1988-01-01

    Terminal and lateral tips from fleshy rhizomes of Alstroemeria hybrids were isolated in vitro and induced to form a new rhizome. The cultivar Toledo was used in most experiments, but later other cultivars were also tested. The basic culture medium for rhizome isolation and for rhizome multiplication

  18. On the Efficiency of a Base Isolation System

    Directory of Open Access Journals (Sweden)

    Ana-Maria Mitu

    2010-01-01

    Full Text Available The aim of this paper is to present the analyses of the efficiency for a base isolation system. To portray the hysteretic behavior of the devices used for seismic protection the Bouc-Wen model is used. The non-linear first order equation which can describe the evolution of force developed by one device for almost any loading pattern are added to the system of equations which models the dynamical behavior of the protected building. Using Matlab-Simulink software, the model are employed to investigate the efficiency of the base isolation devices by comparing the seismic response of protected and unprotected buildings subjected to strong seismic actions.

  19. Earthquake Activity - SEISMIC_DATA_IN: Seismic Refraction Data for Indiana (Indiana Geological Survey, Point Shapefile)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — SEISMIC_DATA_IN is a point shapefile created from a shapefile named SEISMIC_DATA, which was derived from a Microsoft Excel spreadsheet named SEISMIC_DECODED. The...

  20. null Seismic Creep, null Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Seismic creep is the constant or periodic movement on a fault as contrasted with the sudden rupture associated with an earthquake. It is a usually slow deformation...

  1. Static behaviour of induced seismicity

    CERN Document Server

    Mignan, Arnaud

    2015-01-01

    The standard paradigm to describe seismicity induced by fluid injection is to apply nonlinear diffusion dynamics in a poroelastic medium. I show that the spatiotemporal behaviour and rate evolution of induced seismicity can, instead, be expressed by geometric operations on a static stress field produced by volume change at depth. I obtain laws similar in form to the ones derived from poroelasticity while requiring a lower description length. Although fluid flow is known to occur in the ground, it is not pertinent to the behaviour of induced seismicity. The proposed model is equivalent to the static stress model for tectonic foreshocks generated by the Non- Critical Precursory Accelerating Seismicity Theory. This study hence verifies the explanatory power of this theory outside of its original scope.

  2. Worldwide Marine Seismic Reflection Profiles

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NGDC maintains a large volume of both Analog and Digital seismic reflection data. Currently only a limited number of lines are available online. Digital data include...

  3. Visualization of volumetric seismic data

    Science.gov (United States)

    Spickermann, Dela; Böttinger, Michael; Ashfaq Ahmed, Khawar; Gajewski, Dirk

    2015-04-01

    Mostly driven by demands of high quality subsurface imaging, highly specialized tools and methods have been developed to support the processing, visualization and interpretation of seismic data. 3D seismic data acquisition and 4D time-lapse seismic monitoring are well-established techniques in academia and industry, producing large amounts of data to be processed, visualized and interpreted. In this context, interactive 3D visualization methods proved to be valuable for the analysis of 3D seismic data cubes - especially for sedimentary environments with continuous horizons. In crystalline and hard rock environments, where hydraulic stimulation techniques may be applied to produce geothermal energy, interpretation of the seismic data is a more challenging problem. Instead of continuous reflection horizons, the imaging targets are often steep dipping faults, causing a lot of diffractions. Without further preprocessing these geological structures are often hidden behind the noise in the data. In this PICO presentation we will present a workflow consisting of data processing steps, which enhance the signal-to-noise ratio, followed by a visualization step based on the use the commercially available general purpose 3D visualization system Avizo. Specifically, we have used Avizo Earth, an extension to Avizo, which supports the import of seismic data in SEG-Y format and offers easy access to state-of-the-art 3D visualization methods at interactive frame rates, even for large seismic data cubes. In seismic interpretation using visualization, interactivity is a key requirement for understanding complex 3D structures. In order to enable an easy communication of the insights gained during the interactive visualization process, animations of the visualized data were created which support the spatial understanding of the data.

  4. Seismic properties of polyphase rocks

    Science.gov (United States)

    Wang, Qin

    2005-11-01

    Knowledge about the seismic properties of polyphase rocks is fundamental for interpreting seismic refraction and reflection data and for establishing lithospheric structure and composition models. This study aims to obtain more precise relationships between seismic properties of rocks and controlling factors (e.g., pressure, temperature, mineralogical and chemical compositions, microstructure of rocks), particularly for those rocks imprinted by ultrahigh-pressure (UHP) metamorphism. These relationships will be very helpful to extrapolate calculated and measured seismic properties of rocks to depths of interest and to engender interpretations relevant to petrological composition and tectonic process. An Internet Database of Rock Seismic Properties (DRSP) was set up and a Handbook of Seismic Properties of Minerals, Rocks and Ores was published. They comprise almost all data available in the literature during the past 4 decades and can serve as a convenient, comprehensive and concise information source on physical properties of rocks to the earth sciences and geotechnical communities. Statistical results of the DRSP reveal the dependence of seismic properties on density, porosity, humidity, and mineralogical and chemical compositions. Using 16 different averaging methods, we calculated P-wave velocities of 696 dry samples according to the volume fraction and elastic constants of each constituent mineral. Although only 22 common minerals were taken into account in the computation, the calculated P-wave velocities agree well with laboratory values measured at about 300 MPa, where most microcracks are closed and the mean Vp of a polymineralic rock is exclusively controlled by its modal composition. However, none of these mixture rules can simultaneously fit measured P-wave velocities for all lithologies or at all pressures. Therefore, more prudence is required in selecting an appropriate mixture rule for calculation of seismic velocities of different rock types.

  5. Newberry Seismic Deployment Fieldwork Report

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J; Templeton, D C

    2012-03-21

    This report summarizes the seismic deployment of Lawrence Livermore National Laboratory (LLNL) Geotech GS-13 short-period seismometers at the Newberry Enhanced Geothermal System (EGS) Demonstration site located in Central Oregon. This Department of Energy (DOE) demonstration project is managed by AltaRock Energy Inc. AltaRock Energy had previously deployed Geospace GS-11D geophones at the Newberry EGS Demonstration site, however the quality of the seismic data was somewhat low. The purpose of the LLNL deployment was to install more sensitive sensors which would record higher quality seismic data for use in future seismic studies, such as ambient noise correlation, matched field processing earthquake detection studies, and general EGS microearthquake studies. For the LLNL deployment, seven three-component seismic stations were installed around the proposed AltaRock Energy stimulation well. The LLNL seismic sensors were connected to AltaRock Energy Gueralp CMG-DM24 digitizers, which are powered by AltaRock Energy solar panels and batteries. The deployment took four days in two phases. In phase I, the sites were identified, a cavity approximately 3 feet deep was dug and a flat concrete pad oriented to true North was made for each site. In phase II, we installed three single component GS-13 seismometers at each site, quality controlled the data to ensure that each station was recording data properly, and filled in each cavity with native soil.

  6. seismicity and seismotectonics of Libya

    Science.gov (United States)

    Ben Suleman, abdunnur

    2015-04-01

    Libya, located at the central Mediterranean margin of the African shield, underwent many episodes of orogenic activity that shaped its geological setting. The present day deformation of Libya is the result of the Eurasia-Africa continental collision. The tectonic evolution of Libya has yielded a complex crustal structure that is composed of a series of basins and uplifts. This study aims to explain in detail the seismicity and seismotectonics of Libya using new data recorded by the recently established Libyan National Seismograph Network (LNSN) incorporating other available geophysical and geological information. Detailed investigations of the Libyan seismicity indicates that Libya has experienced earthquakes of varying magnitudes The seismic activity of Libya shows dominant trends of Seismicity with most of the seismic activity concentrated along the northern coastal areas. Four major clusters of Seismicity were quit noticeable. Fault plane solution was estimated for 20 earthquakes recorded by the Libyan National Seismograph Network in northwestern and northeastern Libya. Results of fault plane solution suggest that normal faulting was dominant in the westernmost part of Libya; strike slip faulting was dominant in northern-central part of Libya. The northern-eastern part of the country suggests that dip-dip faulting were more prevalent.

  7. Seismic stratigraphy of the Bahamas

    Energy Technology Data Exchange (ETDEWEB)

    Ladd, J.W.; Sheridan, R.E.

    1987-06-01

    Seismic reflection profiles from the Straits of Florida, Northwest Providence Channel, Tongue of the Ocean, and Exuma Sound reveal a seismic stratigraphy characterized by a series of prograding Upper Cretaceous and Tertiary seismic sequences with seismic velocities generally less than 4 km/sec overlying a Lower Cretaceous section of low-amplitude reflections which are more nearly horizontal than the overlying prograding clinoforms and have seismic velocities greater than 5 km/sec. The prograding units are detrital shallow-water carbonates shed from nearby carbonate banks into deep intrabank basins that were established in the Late Cretaceous. The Lower Cretaceous units are probably shallow-water carbonate banks that were drowned in the middle Cretaceous but which, during the Early Cretaceous, extended from Florida throughout the Bahamas region. The seismic reflection profiles reveal a sharp angular unconformity at 5-sec two-way traveltime in northwest Tongue of the Ocean, suggesting a rift-drift unconformity and deposition on thinned continental crust. No such unconformity is seen in central and southeast Tongue of the Ocean or in Exuma Sound, suggesting that these areas are built on oceanic crust.

  8. Seismic risk perception in Italy

    Science.gov (United States)

    Crescimbene, Massimo; La Longa, Federica; Camassi, Romano; Pino, Nicola Alessandro; Peruzza, Laura

    2014-05-01

    Risk perception is a fundamental element in the definition and the adoption of preventive counter-measures. In order to develop effective information and risk communication strategies, the perception of risks and the influencing factors should be known. This paper presents results of a survey on seismic risk perception in Italy conducted from January 2013 to present . The research design combines a psychometric and a cultural theoretic approach. More than 7,000 on-line tests have been compiled. The data collected show that in Italy seismic risk perception is strongly underestimated; 86 on 100 Italian citizens, living in the most dangerous zone (namely Zone 1), do not have a correct perception of seismic hazard. From these observations we deem that extremely urgent measures are required in Italy to reach an effective way to communicate seismic risk. Finally, the research presents a comparison between groups on seismic risk perception: a group involved in campaigns of information and education on seismic risk and a control group.

  9. Seismicity of the Jalisco Block

    Science.gov (United States)

    Nunez-Cornu, F. J.; Rutz, M.; Camarena-Garcia, M.; Trejo-Gomez, E.; Reyes-Davila, G.; Suarez-Plascencia, C.

    2002-12-01

    In April 2002 began to transmit the stations of the first phase of Jalisco Telemetric Network located at the northwest of Jalisco Block and at the area of Volcan de Fuego (Colima Volcano), in June were deployed four additional MarsLite portable stations in the Bahia de Banderas area, and by the end of August one more portable station at Ceboruco Volcano. The data of these stations jointly with the data from RESCO (Colima Telemetric Network) give us the minimum seismic stations coverage to initiate in a systematic and permanent way the study of the seismicity in this very complex tectonic region. A preliminary analysis of seismicity based on the events registered by the networks using a shutter algorithm, confirms several important features proposed by microseismicity studies carried out between 1996 and 1998. A high level of seismicity inside and below of Rivera plate is observed, this fact suggest a very complex stress pattern acting on this plate. Shallow seismicity at south and east of Bahia de Banderas also suggest a complex stress pattern in this region of the Jalisco Block, events at more than 30 km depth are located under the mouth of the bay and in face of it, a feature denominated Banderas Boundary mark the change of the seismic regime at north of this latitude (20.75°N), however some shallow events were located at the region of Nayarit.

  10. Seismic pattern treatment method through calculation of seismic density at grid nodes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Analysis of seismic data and seismicity characteristics in China, we gave a method to deal with seismic patterns by calculating density at grid nodes. Number of earthquakes and epicenter distribution are considered comprehen-sively in this method. Effect of datum accuracy is stressed on parameter confirmation. Seismic patterns from this method are stable and can reflect seismic characteristics reliably. These seismic patterns are the base of quantita-tive analysis of seismicity. It can be applied in seismic tendency analysis and medium-long term earthquake pre-diction, earthquake countermeasure and risk mitigation.

  11. Romanian Educational Seismic Network Project

    Science.gov (United States)

    Tataru, Dragos; Ionescu, Constantin; Zaharia, Bogdan; Grecu, Bogdan; Tibu, Speranta; Popa, Mihaela; Borleanu, Felix; Toma, Dragos; Brisan, Nicoleta; Georgescu, Emil-Sever; Dobre, Daniela; Dragomir, Claudiu-Sorin

    2013-04-01

    Romania is one of the most active seismic countries in Europe, with more than 500 earthquakes occurring every year. The seismic hazard of Romania is relatively high and thus understanding the earthquake phenomena and their effects at the earth surface represents an important step toward the education of population in earthquake affected regions of the country and aims to raise the awareness about the earthquake risk and possible mitigation actions. In this direction, the first national educational project in the field of seismology has recently started in Romania: the ROmanian EDUcational SEISmic NETwork (ROEDUSEIS-NET) project. It involves four partners: the National Institute for Earth Physics as coordinator, the National Institute for Research and Development in Construction, Urban Planning and Sustainable Spatial Development " URBAN - INCERC" Bucharest, the Babeş-Bolyai University (Faculty of Environmental Sciences and Engineering) and the software firm "BETA Software". The project has many educational, scientific and social goals. The main educational objectives are: training students and teachers in the analysis and interpretation of seismological data, preparing of several comprehensive educational materials, designing and testing didactic activities using informatics and web-oriented tools. The scientific objective is to introduce into schools the use of advanced instruments and experimental methods that are usually restricted to research laboratories, with the main product being the creation of an earthquake waveform archive. Thus a large amount of such data will be used by students and teachers for educational purposes. For the social objectives, the project represents an effective instrument for informing and creating an awareness of the seismic risk, for experimentation into the efficacy of scientific communication, and for an increase in the direct involvement of schools and the general public. A network of nine seismic stations with SEP seismometers

  12. Seismic failure modes and seismic safety of Hardfill dam

    Directory of Open Access Journals (Sweden)

    Kun XIONG

    2013-04-01

    Full Text Available Based on microscopic damage theory and the finite element method, and using the Weibull distribution to characterize the random distribution of the mechanical properties of materials, the seismic response of a typical Hardfill dam was analyzed through numerical simulation during the earthquakes with intensities of 8 degrees and even greater. The seismic failure modes and failure mechanism of the dam were explored as well. Numerical results show that the Hardfill dam remains at a low stress level and undamaged or slightly damaged during an earthquake with an intensity of 8 degrees. During overload earthquakes, tensile cracks occur at the dam surfaces and extend to inside the dam body, and the upstream dam body experiences more serious damage than the downstream dam body. Therefore, under the seismic conditions, the failure pattern of the Hardfill dam is the tensile fracture of the upstream regions and the dam toe. Compared with traditional gravity dams, Hardfill dams have better seismic performance and greater seismic safety.

  13. Physics-based Probabilistic Seismic Hazard Analysis for Seismicity Induced by Fluid Injection

    Science.gov (United States)

    Foxall, W.; Hutchings, L. J.; Johnson, S.; Savy, J. B.

    2011-12-01

    Risk associated with induced seismicity (IS) is a significant factor in the design, permitting and operation of enhanced geothermal, geological CO2 sequestration and other fluid injection projects. Whereas conventional probabilistic seismic hazard and risk analysis (PSHA, PSRA) methods provide an overall framework, they require adaptation to address specific characteristics of induced earthquake occurrence and ground motion estimation, and the nature of the resulting risk. The first problem is to predict the earthquake frequency-magnitude distribution of induced events for PSHA required at the design and permitting stage before the start of injection, when an appropriate earthquake catalog clearly does not exist. Furthermore, observations and theory show that the occurrence of earthquakes induced by an evolving pore-pressure field is time-dependent, and hence does not conform to the assumption of Poissonian behavior in conventional PSHA. We present an approach to this problem based on generation of an induced seismicity catalog using numerical simulation of pressure-induced shear failure in a model of the geologic structure and stress regime in and surrounding the reservoir. The model is based on available measurements of site-specific in-situ properties as well as generic earthquake source parameters. We also discuss semi-empirical analysis to sequentially update hazard and risk estimates for input to management and mitigation strategies using earthquake data recorded during and after injection. The second important difference from conventional PSRA is that in addition to potentially damaging ground motions a significant risk associated with induce seismicity in general is the perceived nuisance caused in nearby communities by small, local felt earthquakes, which in general occur relatively frequently. Including these small, usually shallow earthquakes in the hazard analysis requires extending the ground motion frequency band considered to include the high

  14. National Seismic Network of Georgia

    Science.gov (United States)

    Tumanova, N.; Kakhoberashvili, S.; Omarashvili, V.; Tserodze, M.; Akubardia, D.

    2016-12-01

    Georgia, as a part of the Southern Caucasus, is tectonically active and structurally complex region. It is one of the most active segments of the Alpine-Himalayan collision belt. The deformation and the associated seismicity are due to the continent-continent collision between the Arabian and Eurasian plates. Seismic Monitoring of country and the quality of seismic data is the major tool for the rapid response policy, population safety, basic scientific research and in the end for the sustainable development of the country. National Seismic Network of Georgia has been developing since the end of 19th century. Digital era of the network started from 2003. Recently continuous data streams from 25 stations acquired and analyzed in the real time. Data is combined to calculate rapid location and magnitude for the earthquake. Information for the bigger events (Ml>=3.5) is simultaneously transferred to the website of the monitoring center and to the related governmental agencies. To improve rapid earthquake location and magnitude estimation the seismic network was enhanced by installing additional 7 new stations. Each new station is equipped with coupled Broadband and Strong Motion seismometers and permanent GPS system as well. To select the sites for the 7 new base stations, we used standard network optimization techniques. To choose the optimal sites for new stations we've taken into account geometry of the existed seismic network, topographic conditions of the site. For each site we studied local geology (Vs30 was mandatory for each site), local noise level and seismic vault construction parameters. Due to the country elevation, stations were installed in the high mountains, no accessible in winter due to the heavy snow conditions. To secure online data transmission we used satellite data transmission as well as cell data network coverage from the different local companies. As a result we've already have the improved earthquake location and event magnitudes. We

  15. A study on seismicity and seismic hazard for Karnataka State

    Indian Academy of Sciences (India)

    T G Sitharam; Naveen James; K S Vipin; K Ganesha Raj

    2012-04-01

    This paper presents a detailed study on the seismic pattern of the state of Karnataka and also quantifies the seismic hazard for the entire state. In the present work, historical and instrumental seismicity data for Karnataka (within 300 km from Karnataka political boundary) were compiled and hazard analysis was done based on this data. Geographically, Karnataka forms a part of peninsular India which is tectonically identified as an intraplate region of Indian plate. Due to the convergent movement of the Indian plate with the Eurasian plate, movements are occurring along major intraplate faults resulting in seismic activity of the region and hence the hazard assessment of this region is very important. Apart from referring to seismotectonic atlas for identifying faults and fractures, major lineaments in the study area were also mapped using satellite data. The earthquake events reported by various national and international agencies were collected until 2009. Declustering of earthquake events was done to remove foreshocks and aftershocks. Seismic hazard analysis was done for the state of Karnataka using both deterministic and probabilistic approaches incorporating logic tree methodology. The peak ground acceleration (PGA) at rock level was evaluated for the entire state considering a grid size of 0.05° × 0.05°. The attenuation relations proposed for stable continental shield region were used in evaluating the seismic hazard with appropriate weightage factors. Response spectra at rock level for important Tier II cities and Bangalore were evaluated. The contour maps showing the spatial variation of PGA values at bedrock are presented in this work.

  16. Seismic behaviour of geotechnical structures

    Directory of Open Access Journals (Sweden)

    F. Vinale

    2002-06-01

    Full Text Available This paper deals with some fundamental considerations regarding the behaviour of geotechnical structures under seismic loading. First a complete definition of the earthquake disaster risk is provided, followed by the importance of performing site-specific hazard analysis. Then some suggestions are provided in regard to adequate assessment of soil parameters, a crucial point to properly analyze the seismic behaviour of geotechnical structures. The core of the paper is centered on a critical review of the analysis methods available for studying geotechnical structures under seismic loadings. All of the available methods can be classified into three main classes, including the pseudo-static, pseudo-dynamic and dynamic approaches, each of which is reviewed for applicability. A more advanced analysis procedure, suitable for a so-called performance-based design approach, is also described in the paper. Finally, the seismic behaviour of the El Infiernillo Dam was investigated. It was shown that coupled elastoplastic dynamic analyses disclose some of the important features of dam behaviour under seismic loading, confirmed by comparing analytical computation and experimental measurements on the dam body during and after a past earthquake.

  17. Hybrid microelectronic technology

    Science.gov (United States)

    Moran, P.

    Various areas of hybrid microelectronic technology are discussed. The topics addressed include: basic thick film processing, thick film pastes and substrates, add-on components and attachment methods, thin film processing, and design of thick film hybrid circuits. Also considered are: packaging hybrid circuits, automating the production of hybrid circuits, application of hybrid techniques, customer's view of hybrid technology, and quality control and assurance in hybrid circuit production.

  18. Cooperative inversion of magnetotelluric and seismic data sets

    Science.gov (United States)

    Markovic, M.; Santos, F.

    2012-04-01

    Cooperative inversion of magnetotelluric and seismic data sets Milenko Markovic,Fernando Monteiro Santos IDL, Faculdade de Ciências da Universidade de Lisboa 1749-016 Lisboa Inversion of single geophysical data has well-known limitations due to the non-linearity of the fields and non-uniqueness of the model. There is growing need, both in academy and industry to use two or more different data sets and thus obtain subsurface property distribution. In our case ,we are dealing with magnetotelluric and seismic data sets. In our approach,we are developing algorithm based on fuzzy-c means clustering technique, for pattern recognition of geophysical data. Separate inversion is performed on every step, information exchanged for model integration. Interrelationships between parameters from different models is not required in analytical form. We are investigating how different number of clusters, affects zonation and spatial distribution of parameters. In our study optimization in fuzzy c-means clustering (for magnetotelluric and seismic data) is compared for two cases, firstly alternating optimization and then hybrid method (alternating optimization+ Quasi-Newton method). Acknowledgment: This work is supported by FCT Portugal

  19. Overcoming barriers to high performance seismic design using lessons learned from the green building industry

    Science.gov (United States)

    Glezil, Dorothy

    NEHRP's Provisions today currently governing conventional seismic resistant design. These provisions, though they ensure the life-safety of building occupants, extensive damage and economic losses may still occur in the structures. This minimum performance can be enhanced using the Performance-Based Earthquake Engineering methodology and passive control systems like base isolation and energy dissipation systems. Even though these technologies and the PBEE methodology are effective reducing economic losses and fatalities during earthquakes, getting them implemented into seismic resistant design has been challenging. One of the many barriers to their implementation has been their upfront costs. The green building community has faced some of the same challenges that the high performance seismic design community currently faces. The goal of this thesis is to draw on the success of the green building industry to provide recommendations that may be used overcome the barriers that high performance seismic design (HPSD) is currently facing.

  20. TECHNICAL NOTES SEISMIC SOIL-STRUCTURE INTERACTION ...

    African Journals Online (AJOL)

    dell

    SEISMIC SOIL-STRUCTURE INTERACTION AS A POTENTIAL TOOL FOR. ECONOMICAL SEISMIC ... inherent in the system as in any other material like the superstructure itself. ..... [9] Gazetas, G., “Analysis of Machine. Foundation Vibration: ...

  1. SEG Advances in Rotational Seismic Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Pierson, Robert; Laughlin, Darren; Brune, Bob

    2016-10-17

    Significant advancements in the development of sensors to enable rotational seismic measurements have been achieved. Prototypes are available now to support experiments that help validate the utility of rotational seismic measurements.

  2. Three-dimensional Evolutionary Models of the Qiongxi Structures, Southwestern Sichuan Basin, China: Evidence from Seismic Interpretation and Geomorphology

    Institute of Scientific and Technical Information of China (English)

    JIA Qiupeng; JIA Dong; LUO Liang; CHEN Zhuxin; LI Yiquan; DENG Fei; SUN Shengsi; LI Haibin

    2009-01-01

    Fold terminations are key features in the study of compressional fault-related folds. Such terminations could be due to loss of displacement on the thrust fault or/and forming a lateral or oblique ramp. Thus, high-quality seismic data would help unambiguously define which mechanism should be responsible for the termination of a given fault-related fold. The Qiongxi and Qiongxinan structures in the Sichuan Basin, China are examples of natural fault-propagation folds that possess a northern termination and a structural saddle between them. The folds/fault geometry and along-strike displacement variations are constrained by the industry 3-D seismic volume. We interpret that the plunge of the fold near the northern termination and the structural saddle are due to the loss of displacement along strike. The fault geometry associated with the northern termination changes from a flat-ramp at the crest of the Qiongxinan structure, where displacement is the greatest, to simply a ramp near the northern tip of the Qiongxi structure, without forming a lateral or oblique ramp. In this study, we also use the drainage pattern, embryonic structure preserved in the crest of the Qiongxinan structure and the assumption that displacement along a fault is proportional to the duration of thrusting to propose a model for the lateral propagation of the Qiongxinan and Qiongxi structures. Specifically, we suggest that the structure first initiated as an isolated fault ramp within brittle units. With increased shortening, the fault grows to link with lower detachments in weaker shale units to create a hybridized fault-propagation fold. Our model suggests a possible explanation for the lateral propagation history of the Qiongxinan and Qiongxi structures, and also provides an alternative approach to confirming the activity of the previous Pingluoba structure in the southwestern Sichuan Basin in the late Cenozoic.

  3. Seismic scanning tunneling macroscope - Theory

    KAUST Repository

    Schuster, Gerard T.

    2012-09-01

    We propose a seismic scanning tunneling macroscope (SSTM) that can detect the presence of sub-wavelength scatterers in the near-field of either the source or the receivers. Analytic formulas for the time reverse mirror (TRM) profile associated with a single scatterer model show that the spatial resolution limit to be, unlike the Abbe limit of λ/2, independent of wavelength and linearly proportional to the source-scatterer separation as long as the point scatterer is in the near-field region; if the sub-wavelength scatterer is a spherical impedance discontinuity then the resolution will also be limited by the radius of the sphere. Therefore, superresolution imaging can be achieved as the scatterer approaches the source. This is analogous to an optical scanning tunneling microscope that has sub-wavelength resolution. Scaled to seismic frequencies, it is theoretically possible to extract 100 Hz information from 20 Hz data by imaging of near-field seismic energy.

  4. The Apollo passive seismic experiment

    Science.gov (United States)

    Latham, G. V.; Dorman, H. J.; Horvath, P.; Ibrahim, A. K.; Koyama, J.; Nakamura, Y.

    1979-01-01

    The completed data set obtained from the 4-station Apollo seismic network includes signals from approximately 11,800 events of various types. Four data sets for use by other investigators, through the NSSDC, are in preparation. Some refinement of the lunar model based on seismic data can be expected, but its gross features remain as presented two years ago. The existence of a small, molten core remains dependent upon the analysis of signals from a single, far-side impact. Analysis of secondary arrivals from other sources may eventually resolve this issue, as well as continued refinement of the magnetic field measurements. Evidence of considerable lateral heterogeneity within the moon continues to build. The mystery of the much meteoroid flux estimate derived from lunar seismic measurements, as compared with earth-based estimates, remains; although, significant correlations between terrestrial and lunar observations are beginning to emerge.

  5. 利用DGGE-菌落原位杂交法分离土壤中精喹禾灵降解菌%Isolation of Quizalofop-p-ethyl-degrading Bacteria from Soil by DGGE-Colony in situ Hybridization

    Institute of Scientific and Technical Information of China (English)

    吕欣; 彭霞薇; 呼庆; 马安周; 江泽平; 魏远

    2013-01-01

    Naturally occurring bacteria isolates capable of metabolizing pesticides have received considerable attention because they offer the possibility of both environmentally friendly and in situ remediation. The effect of herbicide quizalofop-p-ethyl on bacterial community in soil was analyzed using the technique of PCR-DGGE for isolating strains biodegrading quizalofop-p-ethyl. Results indicated that the soil bacterial community structures significantly changed after adding quizalofop-p-ethyl. The bacterial diversity of soil showed an increasing-decreasing-increasing trend. The largest changes occurred in the 9th day and then became stabilized. According to the sequencing results of bands in DGGE profiles, it inferred that members of bacterial genera Pseudomonas, Massilia and Burkholderia had tolerance to quizalofop-p-ethyl, and the potential for degradation. These microbial groups could be used to isolate and screen as the indigenous microbial resources to reduce pesticide residues. Digoxigenin-labeled probes had been synthesized based on the sequencing results of bands in the DGGE profiles, and three bacterial strains capable of biodegrading quizalofop-p-ethyl were isolated from soil by colony in situ hybridization technique. The strain named LI was able to utilize quizalofop-p-ethyl as the sole source of carbon. The strain was identified as Pseudomonas sp., based on the phylogenetic analysis of 16S rRNA. The degrading ability of strain L1 in minimal medium with quizalofop-p-ethyl was investigated by HPLC. The quizalofop-p-ethyl content decreased by almost 50% after 7 days, and the biomass of strain L1 increased while the content of quizalofop-p-ethyl was decreased. This confirmed that the strain L1 had the capacity of degradation. This result provided a basis for future research on degradation mechanism and functional genes.%从自然环境中分离到的可降解农药的土著微生物,因其对环境的友好性及原位修复的可行性,受到了高度关注.

  6. Time-Dependent Seismic Tomography

    Science.gov (United States)

    Julian, B. R.

    2008-12-01

    Temporal changes in seismic wave speeds in the Earth's crust have been measured at several locations, notably The Geysers geothermal area in California, in studies that used three-dimensional seismic tomography. These studies have used conventional tomography methods to invert multiple seismic-wave arrival time data sets independently and assumed that any differences in the derived structures reflect real temporal variations. Such an assumption is dangerous because the results of repeated tomography experiments would differ even if the structure did not change, simply because of variation in the seismic ray distribution caused by the natural variation in earthquake locations. This problem can be severe when changes in the seismicity distribution are systematic, as, for example, at the onset of an aftershock sequence. The sudden change in the ray distribution can produce artifacts that mimic changes in the seismic wave speeds at the time of a large earthquake. Even if the source locations did not change (if only explosion data were used, for example), derived structures would inevitably differ because of observational errors. A better approach to determining what temporal changes are truly required by the data is to invert multiple data sets simultaneously, imposing constraints to minimize differences between the models for different epochs. This problem is similar to that of seeking models similar to some a priori initial assumption, and a method similar to "damped least squares" can solve it. The order of the system of normal equations for inverting data from two epochs is twice as large as that for a single epoch, and solving it by standard methods requires eight times the computational labor. We present an algorithm for reducing this factor to two, so that inverting multiple epochs simultaneously is comparable in difficulty to inverting them independently, and illustrate its performance using synthetic arrival times and observed data from several areas in

  7. USGS National Seismic Hazard Maps

    Science.gov (United States)

    Frankel, A.D.; Mueller, C.S.; Barnhard, T.P.; Leyendecker, E.V.; Wesson, R.L.; Harmsen, S.C.; Klein, F.W.; Perkins, D.M.; Dickman, N.C.; Hanson, S.L.; Hopper, M.G.

    2000-01-01

    The U.S. Geological Survey (USGS) recently completed new probabilistic seismic hazard maps for the United States, including Alaska and Hawaii. These hazard maps form the basis of the probabilistic component of the design maps used in the 1997 edition of the NEHRP Recommended Provisions for Seismic Regulations for New Buildings and Other Structures, prepared by the Building Seismic Safety Council arid published by FEMA. The hazard maps depict peak horizontal ground acceleration and spectral response at 0.2, 0.3, and 1.0 sec periods, with 10%, 5%, and 2% probabilities of exceedance in 50 years, corresponding to return times of about 500, 1000, and 2500 years, respectively. In this paper we outline the methodology used to construct the hazard maps. There are three basic components to the maps. First, we use spatially smoothed historic seismicity as one portion of the hazard calculation. In this model, we apply the general observation that moderate and large earthquakes tend to occur near areas of previous small or moderate events, with some notable exceptions. Second, we consider large background source zones based on broad geologic criteria to quantify hazard in areas with little or no historic seismicity, but with the potential for generating large events. Third, we include the hazard from specific fault sources. We use about 450 faults in the western United States (WUS) and derive recurrence times from either geologic slip rates or the dating of pre-historic earthquakes from trenching of faults or other paleoseismic methods. Recurrence estimates for large earthquakes in New Madrid and Charleston, South Carolina, were taken from recent paleoliquefaction studies. We used logic trees to incorporate different seismicity models, fault recurrence models, Cascadia great earthquake scenarios, and ground-motion attenuation relations. We present disaggregation plots showing the contribution to hazard at four cities from potential earthquakes with various magnitudes and

  8. Historical Seismicity of Central Panama

    Science.gov (United States)

    Camacho, E.

    2013-05-01

    Central Panama lies in the Panama microplate, neighboring seismically active regions of Costa Rica and Colombia. This region, crossed by the Panama Canal, concentrates most of the population and economic activity of the Republic of Panama. Instrumental observation of earthquakes in Panama began on 1882 by the Compagnie Universelle du Canal Interocéanique de Panama and continued from 1904 to 1977 by the Panama Canal Company. From October 1997 to March 1998 the USGS deployed a temporary digital seismic network. Since 2003 this region is monitored by a digital seismic network operated by the Panama Canal Authority and I complemented by the broad band stations of the University of Panama seismic network. The seismicity in this region is very diffuse and the few events which are recorded have magnitudes less than 3.0. Historical archives and antique newspapers from Spain, Colombia, Panama and the United Sates have been searched looking for historical earthquake information which could provide a better estimate of the seismicity in this region. We find that Panama City has been shaken by two destructive earthquakes in historical times. One by a local fault (i.e. Pedro Miguel fault) on May 2, 1621 (I=Vlll MM), and a subduction event from the North Panama Deformed Belt (NPDB) on September 7, 1882 (I=Vll MM). To test these findings two earthquakes scenarios were generated, using SELENA, for Panama City Old Quarter. Panama City was rebuilt on January 21, 1673, on a rocky point facing the Pacific Ocean after the sack by pirate Morgan on January 28, 1671. The pattern of damage to calicanto (unreinforced colonial masonry) and wood structures for a crustal local event are higher than those for an event from the NPDB and seem to confirm that the city has not been shaken by a major local event since May 2, 1621 and a subduction event since September 7, 1882

  9. A Review of Seismicity in 2008

    Institute of Scientific and Technical Information of China (English)

    Li Gang; Liu Jie; Yu Surong

    2009-01-01

    @@ 1 SURVEY OF GLOBE SEISMICITY IN 2008 A total of 19 strong earthquakes with Ms≥7.0 occurred in the world in 2008 according to the Chinese Seismic Station Network (Table 1 ). The strongest earthquake was the Wenchuan earthquake with Ms8.0 on May 12,2008 (Fig.1). Earthquake frequency was apparently lower and the energy release remarkably attenuated in 2008, compared to seismicity in 2007. The characteristics of seismicity are as follows:

  10. Seismic detection of meteorite impacts on Mars

    OpenAIRE

    Teanby, N.A.; Wookey, J.

    2011-01-01

    Abstract Meteorite impacts provide a potentially important seismic source for probing Mars? interior. It has recently been shown that new craters can be detected from orbit using high resolution imaging, which means the location of any impact-related seismic event could be accurately determined thus improving the constraints that could be placed on internal structure using a single seismic station. This is not true of other seismic sources on Mars such as sub-surface faulting, whic...

  11. Time-lapse seismic within reservoir engineering

    OpenAIRE

    Oldenziel, T.

    2003-01-01

    Time-lapse 3D seismic is a fairly new technology allowing dynamic reservoir characterisation in a true volumetric sense. By investigating the differences between multiple seismic surveys, valuable information about changes in the oil/gas reservoir state can be captured. Its interpretation involves different disciplines, of which the main three are: reservoir management, rock physics, and seismics. The main challenge is expressed as "How to optimally benefit from time-lapse seismic". The chall...

  12. Robustness of timber structures in seismic areas

    OpenAIRE

    Neves, Luís A.C.; Branco, Jorge M.

    2011-01-01

    Major similarities between robustness assessment and seismic design exist, and significant information can be brought from seismic design to robustness design. As will be discussed, although some methods and limitations considered in seismic design can improve robustness, the capacity of the structure to sustain limited damage without disproportionate effects is significantly more complex. In fact, seismic design can either improve or reduce the resistance of structures to unfo...

  13. Behavioral and spermatogenic hybrid male breakdown in Nasonia.

    Science.gov (United States)

    Clark, M E; O'Hara, F P; Chawla, A; Werren, J H

    2010-03-01

    Several reproductive barriers exist within the Nasonia species complex, including allopatry, premating behavioral isolation, postzygotic inviability and Wolbachia-induced cytoplasmic incompatibility. Here we show that hybrid males suffer two additional reproductive disadvantages, an inability to properly court females and decreased sperm production. Hybrid behavioral sterility, characterized by a reduced ability of hybrids to perform necessary courtship behaviors, occurs in hybrids between two species of Nasonia. Hybrid males produced in crosses between N. vitripennis and N. giraulti courted females at a reduced frequency (23-69%), compared with wild-type N. vitripennis and N. giraulti males (>93%). Reduced courtship frequency was not a simple function of inactivity among hybrids. A strong effect of cytoplasmic (mitochondrial) background was also found in N. vitripennis and N. giraulti crosses; F2 hybrids with giraulti cytoplasm showing reduced ability at most stages of courtship. Hybrids produced between a younger species pair, N. giraulti and N. longicornis, were behaviorally fertile. All males possessed motile sperm, but sperm production is greatly reduced in hybrids between the older species pair, N. vitripennis and N. giraulti. This effect on hybrid males, lowered sperm counts rather than nonfunctional sperm, is different from most described cases of hybrid male sterility, and may represent an earlier stage of hybrid sperm breakdown. The results add to previous studies of F2 hybrid inviability and behavioral sterility, and indicate that Wolbachia-induced hybrid incompatibility has arisen early in species divergence, relative to behavioral sterility and spermatogenic infertility.

  14. Advanced Seismic While Drilling System

    Energy Technology Data Exchange (ETDEWEB)

    Robert Radtke; John Fontenot; David Glowka; Robert Stokes; Jeffery Sutherland; Ron Evans; Jim Musser

    2008-06-30

    A breakthrough has been discovered for controlling seismic sources to generate selectable low frequencies. Conventional seismic sources, including sparkers, rotary mechanical, hydraulic, air guns, and explosives, by their very nature produce high-frequencies. This is counter to the need for long signal transmission through rock. The patent pending SeismicPULSER{trademark} methodology has been developed for controlling otherwise high-frequency seismic sources to generate selectable low-frequency peak spectra applicable to many seismic applications. Specifically, we have demonstrated the application of a low-frequency sparker source which can be incorporated into a drill bit for Drill Bit Seismic While Drilling (SWD). To create the methodology of a controllable low-frequency sparker seismic source, it was necessary to learn how to maximize sparker efficiencies to couple to, and transmit through, rock with the study of sparker designs and mechanisms for (a) coupling the sparker-generated gas bubble expansion and contraction to the rock, (b) the effects of fluid properties and dynamics, (c) linear and non-linear acoustics, and (d) imparted force directionality. After extensive seismic modeling, the design of high-efficiency sparkers, laboratory high frequency sparker testing, and field tests were performed at the University of Texas Devine seismic test site. The conclusion of the field test was that extremely high power levels would be required to have the range required for deep, 15,000+ ft, high-temperature, high-pressure (HTHP) wells. Thereafter, more modeling and laboratory testing led to the discovery of a method to control a sparker that could generate low frequencies required for deep wells. The low frequency sparker was successfully tested at the Department of Energy Rocky Mountain Oilfield Test Center (DOE RMOTC) field test site in Casper, Wyoming. An 8-in diameter by 26-ft long SeismicPULSER{trademark} drill string tool was designed and manufactured by TII

  15. Community Seismic Network (CSN)

    Science.gov (United States)

    Clayton, R. W.; Heaton, T. H.; Kohler, M. D.; Cheng, M.; Guy, R.; Chandy, M.; Krause, A.; Bunn, J.; Olson, M.; Faulkner, M.; Liu, A.; Strand, L.

    2012-12-01

    We report on developments in sensor connectivity, architecture, and data fusion algorithms executed in Cloud computing systems in the Community Seismic Network (CSN), a network of low-cost sensors housed in homes and offices by volunteers in the Pasadena, CA area. The network has over 200 sensors continuously reporting anomalies in local acceleration through the Internet to a Cloud computing service (the Google App Engine) that continually fuses sensor data to rapidly detect shaking from earthquakes. The Cloud computing system consists of data centers geographically distributed across the continent and is likely to be resilient even during earthquakes and other local disasters. The region of Southern California is partitioned in a multi-grid style into sets of telescoping cells called geocells. Data streams from sensors within a geocell are fused to detect anomalous shaking across the geocell. Temporal spatial patterns across geocells are used to detect anomalies across regions. The challenge is to detect earthquakes rapidly with an extremely low false positive rate. We report on two data fusion algorithms, one that tessellates the surface so as to fuse data from a large region around Pasadena and the other, which uses a standard tessellation of equal-sized cells. Since September 2011, the network has successfully detected earthquakes of magnitude 2.5 or higher within 40 Km of Pasadena. In addition to the standard USB device, which connects to the host's computer, we have developed a stand-alone sensor that directly connects to the internet via Ethernet or wifi. This bypasses security concerns that some companies have with the USB-connected devices, and allows for 24/7 monitoring at sites that would otherwise shut down their computers after working hours. In buildings we use the sensors to model the behavior of the structures during weak events in order to understand how they will perform during strong events. Visualization models of instrumented buildings ranging

  16. Seismic Physical Modeling Technology and Its Applications

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper introduces the seismic physical modeling technology in the CNPC Key Lab of Geophysical Exploration. It includes the seismic physical model positioning system, the data acquisition system, sources, transducers,model materials, model building techniques, precision measurements of model geometry, the basic principles of the seismic physical modeling and experimental methods, and two physical model examples.

  17. Seismic processing in the inverse data space

    NARCIS (Netherlands)

    Berkhout, A.J.

    2006-01-01

    Until now, seismic processing has been carried out by applying inverse filters in the forward data space. Because the acquired data of a seismic survey is always discrete, seismic measurements in the forward data space can be arranged conveniently in a data matrix (P). Each column in the data matrix

  18. Simplified seismic performance assessment and implications for seismic design

    Science.gov (United States)

    Sullivan, Timothy J.; Welch, David P.; Calvi, Gian Michele

    2014-08-01

    The last decade or so has seen the development of refined performance-based earthquake engineering (PBEE) approaches that now provide a framework for estimation of a range of important decision variables, such as repair costs, repair time and number of casualties. This paper reviews current tools for PBEE, including the PACT software, and examines the possibility of extending the innovative displacement-based assessment approach as a simplified structural analysis option for performance assessment. Details of the displacement-based s+eismic assessment method are reviewed and a simple means of quickly assessing multiple hazard levels is proposed. Furthermore, proposals for a simple definition of collapse fragility and relations between equivalent single-degree-of-freedom characteristics and multi-degree-of-freedom story drift and floor acceleration demands are discussed, highlighting needs for future research. To illustrate the potential of the methodology, performance measures obtained from the simplified method are compared with those computed using the results of incremental dynamic analyses within the PEER performance-based earthquake engineering framework, applied to a benchmark building. The comparison illustrates that the simplified method could be a very effective conceptual seismic design tool. The advantages and disadvantages of the simplified approach are discussed and potential implications of advanced seismic performance assessments for conceptual seismic design are highlighted through examination of different case study scenarios including different structural configurations.

  19. Expanding Conventional Seismic Stratigrphy into the Multicomponent Seismic Domain

    Energy Technology Data Exchange (ETDEWEB)

    Innocent Aluka

    2008-08-31

    Multicomponent seismic data are composed of three independent vector-based seismic wave modes. These wave modes are, compressional mode (P), and shear modes SV and SH. The three modes are generated using three orthogonal source-displacement vectors and then recorded using three orthogonal vector sensors. The components travel through the earth at differing velocities and directions. The velocities of SH and SV as they travel through the subsurface differ by only a few percent, but the velocities of SV and SH (Vs) are appreciably lower than the P-wave velocity (Vp). The velocity ratio Vp/Vs varies by an order of magnitude in the earth from a value of 15 to 1.5 depending on the degree of sedimentary lithification. The data used in this study were acquired by nine-component (9C) vertical seismic profile (VSP), using three orthogonal vector sources. The 9C vertical seismic profile is capable of generating P-wave mode and the fundamental S-wave mode (SH-SH and SV-SV) directly at the source station and permits the basic components of elastic wavefield (P, SH-SH and SV-SV) to be separated from one another for the purposes of imaging. Analysis and interpretations of data from the study area show that incident full-elastic seismic wavefield is capable of reflecting four different wave modes, P, SH , SV and C which can be utilized to fully understand the architecture and heterogeneities of geologic sequences. The conventional seismic stratigraphy utilizes only reflected P-wave modes. The notation SH mode is the same as SH-SH; SV mode means SV-SV and C mode which is a converted shear wave is a special SV mode and is the same as P-SV. These four wave modes image unique geologic stratigraphy and facies and at the same time reflect independent stratal surfaces because of the unique orientation of their particle-displacement vectors. As a result of the distinct orientation of individual mode's particle-displacement vector, one mode may react to a critical subsurface sequence

  20. Anatomy of the TAMA SAS seismic attenuation system

    CERN Document Server

    Marka, S; Ando, M; Bertolini, A; Cella, G; DeSalvo, R; Fukushima, M; Iida, Y; Jacquier, F; Kawamura, S; Nishi, Y; Numata, K; Sannibale, V; Somiya, K; Takahashi, R; Tariq, H; Tsubono, K; Ugas, J; Viboud, N; Wang Chen Yang; Yamamoto, H; Yoda, T

    2002-01-01

    The TAMA SAS seismic attenuation system was developed to provide the extremely high level of seismic isolation required by the next generation of interferometric gravitational wave detectors to achieve the desired sensitivity at low frequencies. Our aim was to provide good performance at frequencies above approx 10 Hz, while utilizing only passive subsystems in the sensitive frequency band of the TAMA interferometric gravitational wave detectors. The only active feedback is relegated below 6 Hz and it is used to damp the rigid body resonances of the attenuation chain. Simulations, based on subsystem performance characterizations, indicate that the system can achieve rms mirror residual motion measured in a few tens of nanometres. We will give a brief overview of the subsystems and point out some of the characterization results, supporting our claims of achieved performance. SAS is a passive, UHV compatible and low cost system. It is likely that extremely sensitive experiments in other fields will also profit ...

  1. Hybrid Gear

    Science.gov (United States)

    Handschuh, Robert F. (Inventor); Roberts, Gary D. (Inventor)

    2016-01-01

    A hybrid gear consisting of metallic outer rim with gear teeth and metallic hub in combination with a composite lay up between the shaft interface (hub) and gear tooth rim is described. The composite lay-up lightens the gear member while having similar torque carrying capability and it attenuates the impact loading driven noise/vibration that is typical in gear systems. The gear has the same operational capability with respect to shaft speed, torque, and temperature as an all-metallic gear as used in aerospace gear design.

  2. Hybrid Qualifications

    DEFF Research Database (Denmark)

    has turned out as a major focus of European education and training policies and certainly is a crucial principle underlying the European Qualifications Framework (EQF). In this context, «hybrid qualifications» (HQ) may be seen as an interesting approach to tackle these challenges as they serve «two...... masters», i.e. by producing skills for the labour market and enabling individuals to progress more or less directly to higher education. The specific focus of this book is placed on conditions, structures and processes which help to combine VET with qualifications leading into higher education...

  3. Application of Genetic Algorithms in Seismic Tomography

    Science.gov (United States)

    Soupios, Pantelis; Akca, Irfan; Mpogiatzis, Petros; Basokur, Ahmet; Papazachos, Constantinos

    2010-05-01

    application of hybrid genetic algorithms in seismic tomography is examined and the efficiency of least squares and genetic methods as representative of the local and global optimization, respectively, is presented and evaluated. The robustness of both optimization methods has been tested and compared for the same source-receiver geometry and characteristics of the model structure (anomalies, etc.). A set of seismic refraction synthetic (noise free) data was used for modeling. Specifically, cross-well, down-hole and typical refraction studies using 24 geophones and 5 shoots were used to confirm the applicability of the genetic algorithms in seismic tomography. To solve the forward modeling and estimate the traveltimes, the revisited ray bending method was used supplemented by an approximate computation of the first Fresnel volume. The root mean square (rms) error as the misfit function was used and calculated for the entire random velocity model for each generation. After the end of each generation and based on the misfit of the individuals (velocity models), the selection, crossover and mutation (typical process steps of genetic algorithms) were selected continuing the evolution theory and coding the new generation. To optimize the computation time, since the whole procedure is quite time consuming, the Matlab Distributed Computing Environment (MDCE) was used in a multicore engine. During the tests, we noticed that the fast convergence that the algorithm initially exhibits (first 5 generations) is followed by progressively slower improvements of the reconstructed velocity models. Thus, to improve the final tomographic models, a hybrid genetic algorithm (GA) approach was adopted by combining the GAs with a local optimization method after several generations, on the basis of the convergence of the resulting models. This approach is shown to be efficient, as it directs the solution search towards a model region close to the global minimum solution.

  4. Somatic hybridization in higher plants.

    Science.gov (United States)

    Constabel, F

    1976-11-01

    Somatic hybridization in higher plants has come into focus since methods have been established for protoplast fusion and uptake of foreign DNA and organelles by protoplasts. Polyethylene glycol (PEG) was an effective agent for inducing fusion. Treatment of protoplasts with PEG resulted in 5 to 30% heterospecific fusion products. Protoplasts of different species, genera and even families were compatible when fused. A number of protoplast combinations (soybean + corn, soybean + pea, soybean + tobacco, carrot + barley, etc.) provided fusion products which underwent cell division and callus formation. Fusion products initially were heterokaryocytes. In dividing heterokaryocytes, random distribution of mitotic nuclei was observed to be accompanied by multiple wall formation and to result in chimeral callus. Juxtaposition of mitotic nuclei suggested nuclear fusion and hybrid formation. Fusion of heterospecific interphase nuclei was demonstrated in soybean + pea and carrot + barley heterokaryons. Provided parental protoplasts carry suitable markers, the fusion products can be recognized. For the isolation and cloning of hybrid cells, fusion experiments must be supplemented with a selective system. Complementation of two non-allelic genes that prevent or inhibit growth under special culture conditions appears as the principle on which to base the selection of somatic hybrids. As protoplasts of some species have been induced to regenerate entire plants, the development of hybrid plants from protoplast fusion products is feasible and has already been demonstrated for tobacco.

  5. Hybridization in a warmer world.

    Science.gov (United States)

    Chunco, Amanda J

    2014-05-01

    Climate change is profoundly affecting the evolutionary trajectory of individual species and ecological communities, in part through the creation of novel species assemblages. How climate change will influence competitive interactions has been an active area of research. Far less attention, however, has been given to altered reproductive interactions. Yet, reproductive interactions between formerly isolated species are inevitable as populations shift geographically and temporally as a result of climate change, potentially resulting in introgression, speciation, or even extinction. The susceptibility of hybridization rates to anthropogenic disturbance was first recognized in the 1930s. To date, work on anthropogenically mediated hybridization has focused primarily on either physical habitat disturbance or species invasion. Here, I review recent literature on hybridization to identify how ecological responses to climate change will increase the likelihood of hybridization via the dissolution of species barriers maintained by habitat, time, or behavior. Using this literature, I identify several cases where novel hybrid zones have recently formed, likely as a result of changing climate. Future research should focus on identifying areas and taxonomic groups where reproductive species interactions are most likely to be influenced by climate change. Furthermore, a better understanding of the evolutionary consequences of climate-mediated secondary contact is urgently needed. Paradoxically, hybridization is both a major conservation concern and an important source of novel genetic and phenotypic variation. Hybridization may therefore both contribute to increasing rates of extinction and stimulate the creation of novel phenotypes that will speed adaptation to novel climates. Predicting which result will occur following secondary contact will be an important contribution to conservation for many species.

  6. Evaluation of structural issues related to isolation of the 100-KE/100-KW discharge chute

    Energy Technology Data Exchange (ETDEWEB)

    Winkel, B.V.; Hyde, L.L.

    1995-03-10

    The issue of excessive post-seismic leakage in the discharge chute of the K East and K West fuel storage basins was resolved by designing isolation barriers to maintain basin water levels if the discharge chute should drain. This report addresses the structural issues associated with isolation of the discharge chute. The report demonstrates the structural adequacy of the components associated with chute isolation for normal and seismic loading. Associated issues, such as hardware drop accidents and seismic slosh heights are also addressed.

  7. Hydraulic External Pre-Isolator System for LIGO

    CERN Document Server

    Wen, S; Mason, K; Giaime, J; Abbott, R; Kern, J; O'Reilly, B; Bork, R; Hammond, M; Hardham, C; Lantz, B; Hua, W; Coyne, D; Traylor, G; Overmier, H; Evans, T; Hanson, J; Spjeld, O; Macinnis, M; Mailand, K; Sellers, D; Carter, K; Sarin, P

    2013-01-01

    The Hydraulic External Pre-Isolator (HEPI) is the first 6 degrees of freedom active seismic isolation system implemented at the Laser Interferometer Gravitational Wave Observatory (LIGO). Implementation was first completed at the LIGO Livingston Observatory (LLO) prior to LIGO's 5th science run, successfully cutting down the disturbance seen by LLO's suspended optics in the two most prominent seismic disturbance bands, the microseism (0.1-0.3Hz) and the anthropogenic (1-3Hz) bands, by a factor of a few to tens. The improvement in seismic isolation contributed directly to LLO's much improved duty cycle of 66.7% and LIGO's triple coincident duty cycle of 53%. We report the design, control scheme, and isolation performance of HEPI at LLO in this paper. Aided with this success, funding for incorporating HEPI into the LIGO Hanford Observatory was approved and installation is currently underway.

  8. Hydraulic external pre-isolator system for LIGO

    Science.gov (United States)

    Wen, S.; Mittleman, R.; Mason, K.; Giaime, J.; Abbott, R.; Kern, J.; O'Reilly, B.; Bork, R.; Hammond, M.; Hardham, C.; Lantz, B.; Hua, W.; Coyne, D.; Traylor, G.; Overmier, H.; Evans, T.; Hanson, J.; Spjeld, O.; Macinnis, M.; Mailand, K.; Ottaway, D.; Sellers, D.; Carter, K.; Sarin, P.

    2014-12-01

    The hydraulic external pre-isolator (HEPI) is the first six degrees of freedom active seismic isolation system implemented at the Laser Interferometer Gravitational Wave Observatory (LIGO). Implementation was first completed at the LIGO Livingston Observatory (LLO) prior to LIGO's fifth science run7, successfully cutting down the disturbance seen by LLO's suspended optics in the two most prominent seismic disturbance bands, the microseism (0.1-0.3 Hz) and the anthropogenic (1-3 Hz) bands, by a factor of a few to tens. The improvement in seismic isolation contributed directly to LLO's much improved duty cycle of 66.7% and LIGO's triple coincident duty cycle of 53%. We report the design, control scheme, and isolation performance of HEPI at LLO in this paper. Aided by this success, funding for incorporating HEPI into the LIGO Hanford Observatory was approved and installation is currently underway.

  9. Seismic link at plate boundary

    Indian Academy of Sciences (India)

    Faical Ramdani; Omar Kettani; Benaissa Tadili

    2015-06-01

    Seismic triggering at plate boundaries has a very complex nature that includes seismic events at varying distances. The spatial orientation of triggering cannot be reduced to sequences from the main shocks. Seismic waves propagate at all times in all directions, particularly in highly active zones. No direct evidence can be obtained regarding which earthquakes trigger the shocks. The first approach is to determine the potential linked zones where triggering may occur. The second step is to determine the causality between the events and their triggered shocks. The spatial orientation of the links between events is established from pre-ordered networks and the adapted dependence of the spatio-temporal occurrence of earthquakes. Based on a coefficient of synchronous seismic activity to grid couples, we derive a network link by each threshold. The links of high thresholds are tested using the coherence of time series to determine the causality and related orientation. The resulting link orientations at the plate boundary conditions indicate that causal triggering seems to be localized along a major fault, as a stress transfer between two major faults, and parallel to the geothermal area extension.

  10. Southern Appalachian Regional Seismic Network

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, S.C.C.; Johnston, A.C.; Chiu, J.M. [Memphis State Univ., TN (United States). Center for Earthquake Research and Information

    1994-08-01

    The seismic activity in the southern Appalachian area was monitored by the Southern Appalachian Regional Seismic Network (SARSN) since late 1979 by the Center for Earthquake Research and Information (CERI) at Memphis State University. This network provides good spatial coverage for earthquake locations especially in east Tennessee. The level of activity concentrates more heavily in the Valley and Ridge province of eastern Tennessee, as opposed to the Blue Ridge or Inner Piedmont. The large majority of these events lie between New York - Alabama lineament and the Clingman/Ocoee lineament, magnetic anomalies produced by deep-seated basement structures. Therefore SARSN, even with its wide station spacing, has been able to define the essential first-order seismological characteristics of the Southern Appalachian seismic zone. The focal depths of the southeastern U.S. earthquakes concentrate between 8 and 16 km, occurring principally beneath the Appalachian overthrust. In cross-sectional views, the average seismicity is shallower to the east beneath the Blue Ridge and Piedmont provinces and deeper to the west beneath the Valley and Ridge and the North American craton. Results of recent focal mechanism studies by using the CERI digital earthquake catalog between October, 1986 and December, 1991, indicate that the basement of the Valley and Ridge province is under a horizontal, NE-SW compressive stress. Right-lateral strike-slip faulting on nearly north-south fault planes is preferred because it agrees with the trend of the regional magnetic anomaly pattern.

  11. Seismic hazard studies in Egypt

    Science.gov (United States)

    Mohamed, Abuo El-Ela A.; El-Hadidy, M.; Deif, A.; Abou Elenean, K.

    2012-12-01

    The study of earthquake activity and seismic hazard assessment of Egypt is very important due to the great and rapid spreading of large investments in national projects, especially the nuclear power plant that will be held in the northern part of Egypt. Although Egypt is characterized by low seismicity, it has experienced occurring of damaging earthquake effect through its history. The seismotectonic sitting of Egypt suggests that large earthquakes are possible particularly along the Gulf of Aqaba-Dead Sea transform, the Subduction zone along the Hellenic and Cyprean Arcs, and the Northern Red Sea triple junction point. In addition some inland significant sources at Aswan, Dahshour, and Cairo-Suez District should be considered. The seismic hazard for Egypt is calculated utilizing a probabilistic approach (for a grid of 0.5° × 0.5°) within a logic-tree framework. Alternative seismogenic models and ground motion scaling relationships are selected to account for the epistemic uncertainty. Seismic hazard values on rock were calculated to create contour maps for four ground motion spectral periods and for different return periods. In addition, the uniform hazard spectra for rock sites for different 25 periods, and the probabilistic hazard curves for Cairo, and Alexandria cities are graphed. The peak ground acceleration (PGA) values were found close to the Gulf of Aqaba and it was about 220 gal for 475 year return period. While the lowest (PGA) values were detected in the western part of the western desert and it is less than 25 gal.

  12. Seismic amplitude recovery with curvelets

    NARCIS (Netherlands)

    Moghaddam, P.P.; Herrmann, F.J.; Stolk, C.C.

    2007-01-01

    A non-linear singularity-preserving solution to the least-squares seismic imaging problem with sparseness and continuity constraints is proposed. The applied formalism explores curvelets as a directional frame that, by their sparsity on the image, and their invariance under the imaging operators,

  13. Quantifying Similarity in Seismic Polarizations

    Science.gov (United States)

    Eaton, D. W. S.; Jones, J. P.; Caffagni, E.

    2015-12-01

    Measuring similarity in seismic attributes can help identify tremor, low S/N signals, and converted or reflected phases, in addition to diagnosing site noise and sensor misalignment in arrays. Polarization analysis is a widely accepted method for studying the orientation and directional characteristics of seismic phases via. computed attributes, but similarity is ordinarily discussed using qualitative comparisons with reference values. Here we introduce a technique for quantitative polarization similarity that uses weighted histograms computed in short, overlapping time windows, drawing on methods adapted from the image processing and computer vision literature. Our method accounts for ambiguity in azimuth and incidence angle and variations in signal-to-noise (S/N) ratio. Using records of the Mw=8.3 Sea of Okhotsk earthquake from CNSN broadband sensors in British Columbia and Yukon Territory, Canada, and vertical borehole array data from a monitoring experiment at Hoadley gas field, central Alberta, Canada, we demonstrate that our method is robust to station spacing. Discrete wavelet analysis extends polarization similarity to the time-frequency domain in a straightforward way. Because histogram distance metrics are bounded by [0 1], clustering allows empirical time-frequency separation of seismic phase arrivals on single-station three-component records. Array processing for automatic seismic phase classification may be possible using subspace clustering of polarization similarity, but efficient algorithms are required to reduce the dimensionality.

  14. SEISMIC ATTENUATION FOR RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Joel Walls; M.T. Taner; Naum Derzhi; Gary Mavko; Jack Dvorkin

    2003-12-01

    We have developed and tested technology for a new type of direct hydrocarbon detection. The method uses inelastic rock properties to greatly enhance the sensitivity of surface seismic methods to the presence of oil and gas saturation. These methods include use of energy absorption, dispersion, and attenuation (Q) along with traditional seismic attributes like velocity, impedance, and AVO. Our approach is to combine three elements: (1) a synthesis of the latest rock physics understanding of how rock inelasticity is related to rock type, pore fluid types, and pore microstructure, (2) synthetic seismic modeling that will help identify the relative contributions of scattering and intrinsic inelasticity to apparent Q attributes, and (3) robust algorithms that extract relative wave attenuation attributes from seismic data. This project provides: (1) Additional petrophysical insight from acquired data; (2) Increased understanding of rock and fluid properties; (3) New techniques to measure reservoir properties that are not currently available; and (4) Provide tools to more accurately describe the reservoir and predict oil location and volumes. These methodologies will improve the industry's ability to predict and quantify oil and gas saturation distribution, and to apply this information through geologic models to enhance reservoir simulation. We have applied for two separate patents relating to work that was completed as part of this project.

  15. Seismicity dynamics and earthquake predictability

    Directory of Open Access Journals (Sweden)

    G. A. Sobolev

    2011-02-01

    Full Text Available Many factors complicate earthquake sequences, including the heterogeneity and self-similarity of the geological medium, the hierarchical structure of faults and stresses, and small-scale variations in the stresses from different sources. A seismic process is a type of nonlinear dissipative system demonstrating opposing trends towards order and chaos. Transitions from equilibrium to unstable equilibrium and local dynamic instability appear when there is an inflow of energy; reverse transitions appear when energy is dissipating. Several metastable areas of a different scale exist in the seismically active region before an earthquake. Some earthquakes are preceded by precursory phenomena of a different scale in space and time. These include long-term activation, seismic quiescence, foreshocks in the broad and narrow sense, hidden periodical vibrations, effects of the synchronization of seismic activity, and others. Such phenomena indicate that the dynamic system of lithosphere is moving to a new state – catastrophe. A number of examples of medium-term and short-term precursors is shown in this paper. However, no precursors identified to date are clear and unambiguous: the percentage of missed targets and false alarms is high. The weak fluctuations from outer and internal sources play a great role on the eve of an earthquake and the occurrence time of the future event depends on the collective behavior of triggers. The main task is to improve the methods of metastable zone detection and probabilistic forecasting.

  16. Seismic Imaging of Sandbox Models

    Science.gov (United States)

    Buddensiek, M. L.; Krawczyk, C. M.; Kukowski, N.; Oncken, O.

    2009-04-01

    Analog sandbox simulations have been applied to study structural geological processes to provide qualitative and quantitative insights into the evolution of mountain belts and basins. These sandbox simulations provide either two-dimensional and dynamic or pseudo-three-dimensional and static information. To extend the dynamic simulations to three dimensions, we combine the analog sandbox simulation techniques with seismic physical modeling of these sandbox models. The long-term objective of this approach is to image seismic and seismological events of static and actively deforming 3D analog models. To achieve this objective, a small-scale seismic apparatus, composed of a water tank, a PC control unit including piezo-electric transducers, and a positioning system, was built for laboratory use. For the models, we use granular material such as sand and glass beads, so that the simulations can evolve dynamically. The granular models are required to be completely water saturated so that the sources and receivers are directly and well coupled to the propagating medium. Ultrasonic source frequencies (˜500 kHz) corresponding to wavelengths ˜5 times the grain diameter are necessary to be able to resolve small scale structures. In three experiments of different two-layer models, we show that (1) interfaces of layers of granular materials can be resolved depending on the interface preparation more than on the material itself. Secondly, we show that the dilation between the sand grains caused by a string that has been pulled through the grains, simulating a shear zone, causes a reflection that can be detected in the seismic data. In the third model, we perform a seismic reflection survey across a model that contains both the prepared interface and a shear zone, and apply 2D-seismic reflection processing to improve the resolution. Especially for more complex models, the clarity and penetration depth need to be improved to study the evolution of geological structures in dynamic

  17. Statistical Seismology and Induced Seismicity

    Science.gov (United States)

    Tiampo, K. F.; González, P. J.; Kazemian, J.

    2014-12-01

    While seismicity triggered or induced by natural resources production such as mining or water impoundment in large dams has long been recognized, the recent increase in the unconventional production of oil and gas has been linked to rapid rise in seismicity in many places, including central North America (Ellsworth et al., 2012; Ellsworth, 2013). Worldwide, induced events of M~5 have occurred and, although rare, have resulted in both damage and public concern (Horton, 2012; Keranen et al., 2013). In addition, over the past twenty years, the increase in both number and coverage of seismic stations has resulted in an unprecedented ability to precisely record the magnitude and location of large numbers of small magnitude events. The increase in the number and type of seismic sequences available for detailed study has revealed differences in their statistics that previously difficult to quantify. For example, seismic swarms that produce significant numbers of foreshocks as well as aftershocks have been observed in different tectonic settings, including California, Iceland, and the East Pacific Rise (McGuire et al., 2005; Shearer, 2012; Kazemian et al., 2014). Similarly, smaller events have been observed prior to larger induced events in several occurrences from energy production. The field of statistical seismology has long focused on the question of triggering and the mechanisms responsible (Stein et al., 1992; Hill et al., 1993; Steacy et al., 2005; Parsons, 2005; Main et al., 2006). For example, in most cases the associated stress perturbations are much smaller than the earthquake stress drop, suggesting an inherent sensitivity to relatively small stress changes (Nalbant et al., 2005). Induced seismicity provides the opportunity to investigate triggering and, in particular, the differences between long- and short-range triggering. Here we investigate the statistics of induced seismicity sequences from around the world, including central North America and Spain, and

  18. Intuitionistic hybrid logic

    DEFF Research Database (Denmark)

    Braüner, Torben

    2011-01-01

    Intuitionistic hybrid logic is hybrid modal logic over an intuitionistic logic basis instead of a classical logical basis. In this short paper we introduce intuitionistic hybrid logic and we give a survey of work in the area.......Intuitionistic hybrid logic is hybrid modal logic over an intuitionistic logic basis instead of a classical logical basis. In this short paper we introduce intuitionistic hybrid logic and we give a survey of work in the area....

  19. Continuity Controlled Hybrid Automata

    OpenAIRE

    Bergstra, J. A.; Middelburg, C.A.

    2004-01-01

    We investigate the connections between the process algebra for hybrid systems of Bergstra and Middelburg and the formalism of hybrid automata of Henzinger et al. We give interpretations of hybrid automata in the process algebra for hybrid systems and compare them with the standard interpretation of hybrid automata as timed transition systems. We also relate the synchronized product operator on hybrid automata to the parallel composition operator of the process algebra. It turns out that the f...

  20. Time-dependent seismic tomography

    Science.gov (United States)

    Julian, B.R.; Foulger, G.R.

    2010-01-01

    Of methods for measuring temporal changes in seismic-wave speeds in the Earth, seismic tomography is among those that offer the highest spatial resolution. 3-D tomographic methods are commonly applied in this context by inverting seismic wave arrival time data sets from different epochs independently and assuming that differences in the derived structures represent real temporal variations. This assumption is dangerous because the results of independent inversions would differ even if the structure in the Earth did not change, due to observational errors and differences in the seismic ray distributions. The latter effect may be especially severe when data sets include earthquake swarms or aftershock sequences, and may produce the appearance of correlation between structural changes and seismicity when the wave speeds are actually temporally invariant. A better approach, which makes it possible to assess what changes are truly required by the data, is to invert multiple data sets simultaneously, minimizing the difference between models for different epochs as well as the rms arrival-time residuals. This problem leads, in the case of two epochs, to a system of normal equations whose order is twice as great as for a single epoch. The direct solution of this system would require twice as much memory and four times as much computational effort as would independent inversions. We present an algorithm, tomo4d, that takes advantage of the structure and sparseness of the system to obtain the solution with essentially no more effort than independent inversions require. No claim to original US government works Journal compilation ?? 2010 RAS.